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Page, William Alexander. "Data acquisition for SuperCDMS SNOLAB." Thesis, University of British Columbia, 2015. http://hdl.handle.net/2429/54536.
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The SuperCDMS SNOLAB experiment will use solid state Germanium and Silicon detectors to search for Weakly Interacting Massive Particles (WIMPs), a leading candidate to explain dark matter. WIMPs are thought to exist in halos around galaxies and therefore thought to be constantly streaming through the earth. The CDMS detectors have been developed to measure the energy deposited by a WIMP-nucleon collision in terrestrial calorimeters.
This thesis focusses on the Data Acquisition (DAQ) system that uses Detector Control and Readout Cards (DCRCs) and is designed to be dead- time-less. The DCRCs read in the data stream from the detector’s 12 phonon and 4 ionization energy channels. The DCRCs also control detector settings, and we develop interactive codes to allow users to easily change detector settings through the DCRC. The DAQ is designed to decide which events to write to disk in order to keep data throughput under a limit yet never miss an event that will be useful in the subsequent analysis. In this effort we develop different readout methods of the detector array for the different calibration runs and WIMP search runs. We also develop fast algorithms for rejecting events that fail a certain criteria for being usable. We also present a novel data compression method that reduces the total data volume by a factor of ∼ 16 yet retains all important information. This method involves a large covariance matrix inversion, and we show that this inversion can be consistently computed given that a sufficient amount of data has been used to build the covariance matrix. We also develop a GUI that is a critical element of the detector testing program for SuperCDMS SNOLAB. The GUI accesses the data stream as it is being written to disk, efficiently reads in the waveforms, and displays them in a user-friendly, oscilloscope-like, format. By making use of Fast Fourier Transform technology, the GUI is also capable of displaying incoming data in the frequency domain. This tool will enable a new degree of real-time analysis of detector performance, specifically noise characteristics, at the test facilities in the next stage of detector testing.Science, Faculty of
Physics and Astronomy, Department of
Graduate
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Ruby, Clyde Dwain. "Modular subclass verification safely creating correct subclasses without superclass code /." [Ames, Iowa : Iowa State University], 2006.
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Silva, Graciane Fabiela da. "Extra??o supercr?tica de Lycopodium Clavatum L." Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2014. http://tede2.pucrs.br/tede2/handle/tede/3247.
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Previous issue date: 2014-01-10The Lycopodium genus plants contain secondary metabolites that make them a potential source of pharmacologically active compounds. The extract of the specie Lycopodium clavatum L. presents anticholinesterase, anti-inflammatory, antibacterial, antiviral and antifungal activities. The supercritical fluid extraction has several advantages compared to traditional extraction techniques. Therefore, this study aimed metabolites Lycopodium clavatum L. extraction thru supercritical CO2 process. The supercritical fluid pressure and temperature as well the pretreatment time (soaking the plant in basic solution) influences in lycopodine alkaloid content in the extract were evaluated by an incomplete factorial design with three factors and three levels (Box-Behnken) and response surface methodology. The extract was subjected to Stas-Otto acid-base process and then analyzed by mass spectrometry coupled gas chromatography. The content of lycopodine was defined by normalizing peak areas of the chromatogram. The pressure was evaluated between 200 and 300 bar, the temperature between 40 to 60?C and the immersion time was zero to two hours. Oniy pressure and temperature were statistically significant, for this reason they are ideal parameters for extraction: 300 bar, 40?C, without immersion of the plant in the alkaline solution. Under these conditions we obtained a content of 20.19% of lycopodine the final extract was raised and the yield curve as a function of extraction time. This curve was modeled mathematically, with good fit, for models of Crank (1975), Sovov? (1994) and Reverchon (1996). Thus parameters related the mass transfer were estimated such as difusion coefficient and mass transfer coefficient, which are important for scale-.up and process simulation. In this study, the extraction with supercritical CO2 was found toe technically feasible to obtain lycopodine, since it is more selective and with higher yields compared to the ethanol extraction case.
Plantas do g?nero Lycopodium cont?m metab?litos secund?rios que as tornam uma potencial fonte de compostos farmacologicamente ativos. O extrato da esp?cie Lycopodium clavatum L. apresenta atividade anticolinester?sica, anti-inflamat?ria, antibacteriana, antiviral e antif?ngica. A extra??o com fluido supercr?tico, frente a t?cnicas tradicionais de extra??o, apresenta diversas vantagens quando aplicada a diferentes esp?cies vegetais. Assim, o presente estudo teve por objetivo a aplica??o do processo com CO2 supercr?tico para a extra??o de metab?litos da Lycopodium clavatum L. Foram avaliadas, atrav?s de um planejamento fatorial incompleto com tr?s fatores e tr?s n?veis (Box-Behnken) e da metodologia de superf?cie de resposta, as influ?ncias da press?o e temperatura do fluido supercr?tico e do tempo de pr?-tratamento (imers?o da planta em solu??o b?sica) no teor do alcal?ide licopodina no extrato. O extrato era purificado pelo processo ?cido-base de Stas-Otto e ent?o analisado por cromatografia gasosa acoplada ? espectrometria de massas, sendo o teor de licopodina definido pela normaliza??o das ?reas dos picos do cromatograma. A press?o foi avaliada entre 200 e 300 bar, a temperatura entre 40 a 60?C e o tempo de imers?o foi de zero a duas horas. Apenas press?o e temperatura foram estatisticamente significativas, sendo ent?o par?metros ideais para a extra??o: 300 bar, 40?C, sem a imers?o da planta na solu??o alcalina. Nessas condi??es, obteve-se um teor de 20,29% de licopodina no extrato final e foi levantada a curva de rendimento da extra??o em fun??o tempo. A curva foi modelada matematicamente, com bom ajuste, pelos modelos de Crank (1975), Sovov? (1994) e Reverchon (1996). Assim, foram estimados par?metros relacionados ? transfer?ncia de massa, importantes para simula??o e scale-up do processo, tais como o coeficiente de difus?o e coeficientes de transfer?ncia de massa. Nesse estudo, a extra??o com CO2 supercr?tico mostrou-se tecnicamente vi?vel para a obten??o de licopodina, sendo mais seletiva em rela??o ao processo de extra??o com etanol.
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Hertel, Scott A. (Scott Alexander). "Advancing the search for dark matter : from CDMS II to SuperCDMS." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/79517.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 2012.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 285-294).
An overwhelming proportion of the universe (83% by mass) is composed of particles we know next to nothing about. Detecting these dark matter particles directly, through hypothesized weak-force-mediated recoils with nuclear targets here on earth, could shed light on what these particles are, how they relate to the standard model, and how the standard model fits within a more fundamental understanding. This thesis describes two such experimental efforts: CDMS 11 (2007-2009) and SuperCDMS Soudan (ongoing). The general abilities and sensitivities of both experiments are laid out, placing a special emphasis on the detector technology, and how this technology has evolved from the first to the second experiment. Some topics on which I spent significant efforts are described here only in overview (in particular the details of the CDMS II analysis, which has been laid out many times before), and some topics which are not described elsewhere are given a somewhat deeper treatment. In particular, this thesis is hopefully a good reference for those interested in the annual modulation limits placed on the low-energy portion of the CDMS II exposure, the design of the detectors for SuperCDMS Soudan, and an overview of the extremely informative data these detectors produce. It is an exciting time. The technology I've had the honor to work on the past few years provides a wealth of information about each event, more so than any other direct detection experiment, and we are still learning how to optimally use all this information. Initial tests from the surface and now underground suggest this technology has the background rejection abilities necessary for a planned 200kg experiment or even ton-scale experiment, putting us on the threshold of probing parameter space orders of magnitude from where the field currently stands.
by Scott A. Hertel.
Ph.D.
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Bianco, Antonio. "Sviluppo di un ambiente di simulazione per l’analisi energetica di una supercar a trazione elettrica." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amslaurea.unibo.it/22754/.
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L’obiettivo di questa Tesi di Laurea è quello di sviluppare un ambiente di simulazione per l’analisi energetica di una Supercar a trazione elettrica, dove al suo interno viene implementato un algoritmo di gestione delle macchine elettriche, nell’ottica di ottimizzare il range di chilometri percorsi con un ciclo di scarica della batteria.
Tale progetto è stato svolto con il Prof. Ing. Nicolò Cavina e con Ferrari S.p.A.
I software utilizzati sono MATLAB & Simulink.
L’architettura presa in considerazione permette a tutte le macchine elettriche della vettura di essere a piacimento collegate o scollegate dalle ruote.
Le configurazioni implementate sono: Trazione Anteriore, Posteriore, Integrale ed Optimal.
A partire dai modelli forniti di motori e batteria, è stato completato l’ambiente di simulazione modellando:
DRIVER: simula le richieste di un utente. Riceve in input un ciclo di guida, e restituisce delle richieste di forza ai motori e all’impianto frenante, simulando i pedali di acceleratore e freno.
CENTRALINA: racchiude le logiche di gestione delle macchine elettriche. Sulla base della richiesta ai motori, attraverso un’analisi energetica, fornisce la configurazione Optimal; la quale ottimizza il punto di lavoro delle macchine elettriche, con conseguente minimizzazione delle perdite, permettendo un miglioramento dell’autonomia della vettura, senza trascurare il piacere di guida funzione anche della frequenza dei cambi di configurazione.
SPLIT COPPIA: elabora la richiesta di coppia ai motori, sulla base della configurazione da attuare. Gestisce inoltre le fasi di aggancio e sgancio dei motori dalla ruota.
VEICOLO: riproduce il comportamento della vettura, permettendo il calcolo della velocità di rotazione delle macchine elettriche e della velocità vettura.
SCOPE: utilizzato per la raccolta ed analisi dei dati.
Dall’analisi dei cicli guida simulati, si può affermare che l’implementazione effettuata permette di raggiungere gli obiettivi prefissati.
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Watkins, Sophie Louise. "Chromosomal distribution of the Antennapedia superclass homeobox genes : evolutionary patterns and processes." Thesis, University of Reading, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.250613.
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Guedes, Ana Raquel Carvalho. "Relações interpessoais como vantagem competitiva para o supercado Rena de Itaúna/MG." Florianópolis, SC, 2003. http://repositorio.ufsc.br/xmlui/handle/123456789/85570.
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Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia de Produção.Made available in DSpace on 2012-10-20T20:13:48Z (GMT). No. of bitstreams: 1 225924.pdf: 1873297 bytes, checksum: 44c5cb0afa6432b2463c476cd4713ad6 (MD5)
Neste trabalho são reunidos argumentos que comprovam a importância da valorização das relações interpessoais dentro de uma empresa. No estudo de caso da rede de supermercados RENA, pode-se constatar o valor do elemento humano como potencial estratégico que gera vantagem competitiva. Sendo a cultura organizacional do supermercado a excelência no atendimento, ressalta-se, nesse estudo, o recurso mais valioso da empresa, seu elemento humano, para empreender valores de gestão de pessoas que se comprovam com a conquista de clientes fiéis e liderança de mercado de cidade. A pesquisa, realizada em todos os supermercados RENA de Itaúna / Minas Gerais, constatou a importância de se levantar as percepções que os funcionários têm da empresa através das pesquisas quantitativa e qualitativa e utilizou também o método de experimentação para analisar atitudes, comportamentos e grau de motivação. Os resultados apresentados confirmam que as ferramentas do marketing adotadas nessa empresa, correspondem ao objetivo da dissertação através do impacto das ações empregadas na gestão dos recursos humanos da empresa, gerando vantagem competitiva. Na parte final deste trabalho são apresentadas as conclusões e recomendações para novos estudos.
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Atcitty, Stanley. "Electrochemical Capacitor Characterization for Electric Utility Applications." Diss., Virginia Tech, 2006. http://hdl.handle.net/10919/29613.
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Electrochemical capacitors (ECs) have received a significant level of interest for use in the electric utility industry for a variety of potential applications. For example, ECs integrated with a power conversion system can be used to assist the electric utility by providing voltage support, power factor correction, active filtering, and reactive and active power support. A number of electric utility applications have been proposed but, to date, ECs have not been very well characterized for use in these applications. Consequently, there is a need to gain a better understanding of ECs when used in electric utility applications. ECs are attractive for utility applications because they have higher energy density than conventional capacitors and higher power density than batteries. ECs also have higher cycle life than batteries, which results in longer life spans. To better understand the system dynamics when ECs are used for utility applications requires suitable models that can be incorporated into the variety of software programs currently used to create dynamic simulations for the applications, programs such as PSPICEâ ¢, MATLAB Simulinkâ ¢, and PSCADâ ¢. To obtain a relevant simulation with predictive capability, the behavior of the EC on which the model is based must be well defined; this necessitates a thorough understanding of the electrical characteristics of these devices.
This paper and the associated research focus on the use of the electrochemical impedance spectroscopy (EIS) to develop nonlinear equivalent circuit models to better understand and characterize symmetric ECs (SECs) for electric utility applications. It also focuses on the development of analytical solutions to better understand SEC efficiency and energy utilization.
Representative static synchronous compensator (StatCom) systems, with and with out SECs, were simulated and discussed. The temperature effects on device ionic resistance and capacitance are covered as is the effect of temperature on maximum power transfer to a resistive load. Experimental data showed that the SEC's double-layer capacitance and ionic resistance are voltage dependent. Therefore a voltage-dependent RC network model was developed and validated and the results showed that this type of model mimicked the experimental SEC better than traditional electrical models. Analytical solutions were developed for the efficiency and energy utilization of an SEC. The analytical solutions are a function of operating voltages, constant current, and ionic resistance. The operating voltage method is an important factor in system design because the power conversion interface is typically limited by a voltage window and thus can determine the performance of SECs during charge and discharge. If the operating voltage window is not properly selected the current rating of the system can be reduced thus limiting the SECs performance.Ph. D.
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Gallardo, Paredes Nova Victoria Andrea. "La comunidad LGTBQ+ como prosumidor de fanfiction slash: El caso del fandom Supercorp." Bachelor's thesis, Universidad Peruana de Ciencias Aplicadas (UPC), 2020. http://hdl.handle.net/10757/656047.
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Dentro del mundo de los fandoms, existe un pequeño gran nicho que se llama fanfiction, en donde los fans desarrollan, exploran y crean nuevas historias con sus personajes favoritos. Sin embargo, para la comunidad LGBTQ+, los fanfictions resultan una alternativa atractiva a los medios de comunicación tradicionales, los cuales no brindan la suficiente representación de esta comunidad. Es por ello que esta investigación se enfoca en analizar las prácticas de la comunidad LGTBQ+ como prosumidor de fanfiction y cómo la web 2.0 aporta a estas.Within the fandom world, there is a great little niche called fanfiction, where fans develop, explore, and create new stories with their favorite characters. However, for the LGBTQ + community, fanfictions are an attractive alternative to traditional media, which do not provide enough representation for this community. That is why this research focuses on analyzing the practices of the LGTBQ + community as a fanfiction prosumer and how the web 2.0 contributes to this.
Trabajo de investigación
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Silva, Pedro Miguel Cavaleiro Santos. "Descrição das unidades de recuperação de enxofre na refinaria de Sines." Master's thesis, ISA/UTL, 2012. http://hdl.handle.net/10400.5/5287.
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Mestrado em Engenharia do Ambiente - Instituto Superior de AgronomiaThis work aims to highlight the importance of sulfur recovery units, the procedural and environmental aspects, respectively, in the oil refinery. This processes at Sines Refinery where summary explained and their environmental impact was short seen as well. Without a good performance of sulphur recovery units, lifetime of facilities decreases due to corrosion of the equipment, acknowledging that sulphur poisoning of catalysts makes impossible the operation of catalytic units and concordance with the legislation in force. From a simple atmospheric distillation unit to a more complex one as hydrocracker, lighter chains have to be treated as a guarantee of proper operation of all units downstream as fuel gas and hydrogen consumers. It made a description of the recovery system installed and improvements planned for these units, which responded to a more restrictive legislation. In the description of the sulfur recovery system is given an important relevance to the process CLAUS and SUPERCLAUS® to better characterize the existing system. The current rate of sulfur recovery in Sines Refinery, are roughly 97 percent of which falls within the theoretical values, but the refinery during the licensing process undertaken to achieve higher recovery rates to 98 percent which boosted the improvement project. The project for improvement of manufacturing areas I and II, will lead to an increase, in range of one percentage point, of extraction sulfur from the gaseous effluent. This improvement will be reflected in the seizure of approximately 270 tons of sulfur per year, which was previously issued in the form of SO2 into the main stack of Sines Refinery. The air is a natural resource depending on it all life as we know it whose largely influence, ecosystems, which quality cannot be separated of sustainable development and hence the relevance of the sulphur recovery units.
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Anderson, Adam J. (Adam Jonathan). "A search for light weakly-interacting massive particles with SuperCDMS and applications to neutrino physics." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/99316.
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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Physics, 2015.Title as it appears in MIT Commencement Exercises program, June 5, 2015: Search for light WIMPs with SuperCDMS experiments and applications to neutrino physics Cataloged from PDF version of thesis.
Includes bibliographical references (pages 241-252).
Cosmological and astrophysical evidence indicates that 85% of the matter content of the universe is in the form of non-baryonic dark matter. A large number of experiments are currently undertaking searches for weakly-interacting massive particles (WIMPs), the leading class of particle candidates for dark matter. This thesis describes the results of such a search with the SuperCDMS experiment, which uses Ge detectors cooled to 50 mK to detect ionization and phonons produced by particle interactions. We perform a blind analysis of 577 kg d of exposure on 7 detectors targeting WIMPs with masses < 30 GeV/c2 , where anomalous results have been reported by previous experiments. No significant excess is observed and we set an upper limit on the spin-independent WIMP-nucleon cross section of 1.2 x 10-42 cm 2 at 8 GeV/c2 . We also set constraints on dark matter interactions independent of the dark matter halo physics, as well as on annual modulation of a dark matter signal. Cryogenic detectors similar to SuperCDMS also have potential applications in neutrino physics. We study several configurations in which dark matter detectors could be used with an intense neutrino source to detect an unmeasured Standard Model process called coherent neutrino scattering. This process may be useful, for example, as a calibration for next-generation dark matter detectors, and for constraining eV-scale sterile neutrinos. In addition, small cryogenic X-ray detectors on sounding rockets with large fields-of-view have the unique ability to constrain sterile neutrino dark matter. We set limits on sterile neutrino dark matter using an observation by the XQC instrument, and discuss prospects for a future observation of the galactic center using the Micro-X instrument.
by Adam J. Anderson.
Ph. D.
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Lucas, Aline Machado. "Estudos sistem?ticos de obten??o e impregna??o supercr?tica de extratos de baccharis." Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2015. http://tede2.pucrs.br/tede2/handle/tede/5945.
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Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES
The Baccharis genus has more than 500 species discribed and 90% occur in South America. It has highlighted important feature in the folk medicine being used for digestive problems. Studies report the presence of phenolic compounds and phenolic acids in its non-volatile extracts. Non-volatile extracts are obtained by infusion and/or maceration of parts of the plant in solvent. One way to obtain pure extracts without the need of evaporation of the solvent is the extraction by supercritical fluid. The aim of the present study was to obtain non-volatile compounds of seven Baccharis species: Baccharis microdonta, B. megapotamica, B. vulneraria, B. usteri, B. trimera, B. tridentata, B. uncinella by supercritical extraction in different conditions of operation, analyze them in different chromatographic methods and test its biological activities such as antioxidant and antimicrobial. As it shows high antioxidant potencial and high availability in the nature, the B. uncinella species were selected to continue our studies in order to perform the supercritical impregnation of the extract in sutures, one polymer matrix of PLGA. The antioxidant activity was the chosen characteristic to aggregate in the suture with the objective to enhance the healing were it is used. The results obtained shows that the impregnated material was not visualized through image analysis, but quantification and liberation tests as well as antioxidant activity shows that the impregnation has occurred. The impregnation condition at 150 bar showed superior results in relation to the impregnation at 200 bar, about 50% more mass impregnated and a 30% higher antioxidant activity.
O g?nero Baccharis possui mais de 500 esp?cies descritas sendo que 90% destas ocorrem na Am?rica do Sul. Possui importante destaque na medicina popular sendo utilizadas para problemas digestivos. Estudos reportam a presen?a de compostos fen?licos como flavonoides e ?cidos fen?licos em seus extratos n?o vol?teis. Extratos n?o vol?teis normalmente s?o obtidos por infus?o e/ou macera??o de partes de planta em solvente. Uma forma de obten??o de extratos puros sem necessidade de evapora??o do solvente ? a extra??o por fluido supercr?tico. O objetivo do presente estudo foi obter compostos n?o vol?teis de sete esp?cies de Baccharis: Baccharis microdonta, B. megapotamica, B. vulneraria, B. usteri, B. trimera, B. tridentata, B. uncinella por extra??o supercr?tica em diferentes condi??es de opera??o, analis?-los por diferentes m?todos cromatogr?ficos e testar suas atividades biol?gicas tais como atividade antioxidante e antimicrobiana. Por apresentar um potencial antioxidante elevado e grande disponibilidade na natureza, a esp?cie B. uncinella foi selecionada para dar continuidade aos estudos e realizar a impregna??o supercr?tica do extrato selecionado em fios de sutura, uma matriz polim?rica de PLGA. A atividade antioxidante foi a caracter?stica escolhida para agregar ao fio de sutura com o objetivo de potencializar a cicatriza??o do local onde for aplicado. Os resultados obtidos mostram que o material impregnado n?o foi visualizado atrav?s da an?lise de imagens, mas testes de quantifica??o e libera??o, assim como de atividade antioxidante, comprovaram que ocorre a impregna??o do extrato. A condi??o de impregna??o a 150 bar apresentou resultados superiores em rela??o a impregna??o a 200 bar, aproximadamente 50% mais massa impregnada e e uma atividade antioxidante 30% maior.
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Petersen, Helena de Souza. "Projeto de engenharia do processo de extra??o supercr?tica de cafe?na da erva mate." Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2017. http://tede2.pucrs.br/tede2/handle/tede/7472.
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The supercritical extraction emerged at the last decades as a green technology and as an alternative process to produce natural products and food. The process of supercritical extraction, using CO2 as a solvent, has been extensively studied, but there are fewer works about scale-up. Therefore, this work proposes to study the industrial supercritical fluid extraction of caffeine from yerba mate to produce decaffeinated yerba mate, an innovative product in the market, and caffeine, a product that has equal or even more value in the market than the main product. Design basis of this work are the experimental results of supercritical extraction in pilot scale and the appliance of a scale-up method based on the maintenance of the solvent mass flow and the raw-material mass flow proportion. Thus, process data sheet of main equipment were generated: extraction vessel, heat exchanger and high pressure pump. The maximum daily caffeine extraction capacity was estimated at two tons and the solvent mass flow rate of 22 t/h was obtained from the equation residence time of the solvent, maintaining constant the porosity of the 0.79 bed obtained in scale pilot. In addition, a process flow diagram was proposed for an industrial scale plant supercritical extraction of caffeine from yerba mate.
A extra??o supercr?tica emergiu nas ?ltimas d?cadas como uma tecnologia verde promissora e uma alternativa para o processamento de alimentos e produtos naturais. O processo de extra??o supercr?tica, utilizando CO2 como solvente, vem sendo extensivamente estudado, mas poucos ainda s?o os trabalhos que visam o escalonamento do processo. Logo, este trabalho prop?e estudar o processo industrial de extra??o supercr?tica de cafe?na a partir da erva-mate, que tem como meta produzir erva-mate descafe?nada, produto inovador no mercado, e cafe?na, um subproduto t?o ou mais valorizado que o produto principal. A base de c?lculo s?o os experimentos realizados em escala piloto e a utiliza??o de m?todo de aumento de escala que prop?e a manuten??o de propor??o de massa de solvente e massa de mat?ria-prima. Sendo assim, foram geradas folhas de dados de processo para os principais equipamentos: vaso extrator, trocadores de calor e bomba de alta press?o. A capacidade di?ria m?xima de extra??o de cafe?na foi prevista em duas toneladas e a vaz?o m?ssica de solvente de 22 toneladas/hora foi obtida a partir do equacionamento de tempo de resid?ncia do solvente, mantendo constante a porosidade do leito de 0,79 obtida em escala piloto. Al?m disto, foi proposto um fluxograma para uma planta em escala industrial de extra??o supercr?tica da cafe?na a partir da erva mate.
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Rossa, Guilherme Evaldt. "Desenvolvimento e implanta??o de unidade piloto de precipita??o de part?culas usando antissolvente supercr?tico (SAS)." Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2015. http://tede2.pucrs.br/tede2/handle/tede/3277.
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Previous issue date: 2015-03-03The interest in micro and nanoparticles has grown recently, since the technological advancement increased the possibilities for production and manipulation of these particles. The applications in different sectors, such as pigments, explosives, polymers, pharmaceuticals and superconductors, nanotechnology has increasingly attracted the interest of governments, academic researchers and industry. Among the technologies for obtaining micro- and nanoparticles, stand out those which make use of supercritical antisolvent (SAS). This method enables the obtainment of smaller particles with a more homogeneous size distribution than traditional ones, often eliminating the presence of residual solvent in the particles. In this context, this work aims to build, implant and perform validation test of a SAS process pilot unit, seeking the incorporation of this equipment as a technological tool for development and innovation associated with the production of nanoparticles. The implementation of this project started with the propose of SAS process flowchart; followed by sizing and acquisition of vessels, piping, valves and other necessary items for the equipment assembly, based on the supercritical extraction pilot plant installed at LOPE / PUCRS. In order to validate the equipment, caffeine particles were produced under different experimental conditions. The best performance of the precipitation process was achieved at 100 bar and 60 ? C. The caffeine particles obtained using the deployed equipment were analyzed for morphology and size using images taken by a scanning electron microscope (SEM) and the results were similar to those found in the literature.
O interesse em micro e nanopart?culas tem crescido nos ?ltimos anos, uma vez que o avan?o tecnol?gico ampliou as possibilidades de produ??o e manipula??o dessas part?culas. Por ter aplica??es em diferentes setores, tais como os de pigmentos, explosivos, pol?meros, f?rmacos e supercondutores, a nanotecnologia tem atra?do cada vez mais o interesse de governos, pesquisadores acad?micos e ind?strias. Dentre as tecnologias para obten??o de micro e nanopart?culas, destacam-se as que fazem uso de antissolvente supercr?tico (SAS), visto que possibilitam a obten??o de part?culas menores e com distribui??o granulom?trica mais homog?nea do que os m?todos tradicionais, al?m de muitas vezes eliminarem a presen?a de solvente residual nas part?culas obtidas. Neste contexto, este trabalho tem por objetivo construir, implantar e realizar testes de valida??o de uma unidade piloto experimental do processo SAS, visando incorpora??o deste equipamento como instrumento de desenvolvimento tecnol?gico e inova??o associado ? produ??o de nanopart?culas. A execu??o do projeto iniciou com a proposi??o do fluxograma de processo SAS; em seguida foram dimensionados e adquiridos vasos, tubula??es, conex?es, v?lvulas e outros acess?rios necess?rios para a montagem do equipamento, tendo como base a unidade piloto de extra??o supercr?tica instalada no LOPE/PUCRS. Para valida??o do equipamento, part?culas de cafe?na foram produzidas em diferentes condi??es experimentais. A condi??o mais favor?vel para o melhor rendimento no processo de precipita??o foi a de 100 bar e 60 oC. A produ??o de part?culas de cafe?na no equipamento implementado reproduziu os resultados encontrados na literatura quanto ? morfologia e dimens?o das part?culas obtidas, analisadas atrav?s de imagens obtidas por um microsc?pio eletr?nico de varredura (MEV).
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Silva, Rodrigo Scopel. "Incorpora??o de modelos termodin?micos na modelagem matem?tica de processos de extra??o supercr?tica." Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2013. http://tede2.pucrs.br/tede2/handle/tede/3229.
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Previous issue date: 2013-01-29Clove (Syzygium aromaticum) essential oil is widely cultivated on eastern countries and has antifungal, antibacterial, insecticidal, and antioxidant properties. Given its vegetal structure, Clove essential oil can be extracted by supercritical fluid. The aim of this work is to model the solubility and the mass transfer process of clove essential oil in supercritical carbon dioxide. For the thermodynamic modeling, the Peng Robinson equation of state was coupled with four mixing rules: van der Waals 1 (vdW1), van der Waals 2 (vdW2), Mathias-Klotz-Prausnitz (MKP) and LCVM. Isothermal vapor-liquid equilibria calculation of CO2/clove essential oil were conducted as a binary system and CO2/eugenol/β-caryophyllene as a ternary system, where the oil composition is defined from major oil compounds, i.e., eugenol and β caryophyllene. A Matlab mathematical procedure was developed to obtain the adjustable parameters of the mixing rules for both the binary and ternary mixture at the following temperatures: 313.2 K, 318.2 K and 328.2 K. Results show that the mixing rule that best fit the experimental data for the binary system CO2/clove oil is vdw2 with a %ΔP of 3.07%. For the ternary mixture, the mixing rule that best represent the experimental data is MKP with a %ΔP of 2.18%. The coupling among solubility calculation and mass transfer model described quantitatively very well the extraction experimental data. The coefficient of determination (R2) showed the minimum value of 0.9946 for conditions investigated.
?leo essencial de cravo da ?ndia (Syzygium aromaticum), amplamente cultivado nos pa?ses do leste, apresenta propriedades antibacteriana, anti-f?ngica, inseticida e antioxidante. Devido ?s caracter?sticas da estrutura vegetal do cravo da ?ndia seu ?leo essencial pode ser obtido atrav?s da extra??o por fluido supercr?tico. O objetivo deste trabalho ? modelar a solubilidade do ?leo essencial de cravo em di?xido de carbono supercr?tico e o processo de transfer?ncia de massa de sua extra??o. Para a modelagem termodin?mica, a equa??o de estado de Peng Robinson foi acoplada com quatro regras de mistura: van der Waals 1 (vdW1), van der Waals 2 (vdW2), Mathias-Klotz-Prausnitz (MKP) e LCVM. Foram realizados c?lculos isot?rmicos do equil?brio l?quido-vapor de CO2/?leo essencial de cravo, considerado como um sistema bin?rio e CO2/eugenol/β-cariofileno como um sistema tern?rio, onde a composi??o do ?leo ? definida a partir dos seus compostos majorit?rios, isto ?, eugenol e β-cariofileno. Foi desenvolvida uma rotina matem?tica no software Matlab para obter os par?metros ajust?veis das regras de mistura, tanto para a mistura bin?ria quanto para a mistura tern?ria, nas seguintes temperaturas: 313,2 K, 318,2 K, 328,2 K. Os resultados mostraram que a regra de mistura que melhor ajustou os dados experimentais para o sistema bin?rio CO2/?leo essencial de cravo foi vdW2, com um %ΔP de 3,07%. Para a mistura tern?ria, a regra de mistura que melhor representou os dados experimentais foi MKP com %ΔP igual a 2,18%. Ao acoplar os dados de solubilidade calculados ao modelo de transfer?ncia de massa, observou-se uma grande capacidade de representa??o dos dados experimentais de extra??o. O coeficiente de determina??o (R2) apresentou o valor m?nimo de 0,9946 para as condi??es investigadas.
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Silva, Dannielle Janainne da. "Tratamento de materiais contaminados com bifenilas policloradas (PCBS) via extra??o convencional e flu?do supercr?tico." Universidade Federal do Rio Grande do Norte, 2008. http://repositorio.ufrn.br:8080/jspui/handle/123456789/15758.
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Previous issue date: 2008-12-17Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior
The decontamination of the materials has been subject of some studies. One of the factors that it increases the pollution is the lack of responsibility in the discarding of toxic trash, as for example the presence of PCB (Polychlorinated Biphenyls) in the environment. In the Brazilian regulations, the material contaminated with PCB in concentrations higher than 50 ppm must be stored in special places or destroyed, usually by incineration in plasma furnace with dual steps. Due to high cost of the procedure, new methodologies of PCBs removal has been studied. The objective of this study was to develop an experimental methodology and analytical methodology for quantification of removal of PCBs through out the processes of extractions using supercritical fluid and Soxhlet method, also technical efficiency of the two processes of extraction, in the treatment of contaminated materials with PCBs. The materials studied were soils and wood, both were simulated contamination with concentration of 6.000, 33.000 and 60.000 mg of PCB/ kg of materials. Soxhlet extractions were performed using 100 ml of hexane, and temperature of 180 ?C. Extractions by fluid supercritical were performed at conditions of 200 bar, 70?C, and supercritical CO2 flow-rate of 3 g/min for 1-3 hours. The extracts obtained were quantified using Gas chromatography-mass spectrometry (GC/MS). The conventional extractions were made according to factorial experimental planning technique 22, with aim of study the influence of two variables of process extraction for the Soxhlet method: contaminant concentration and extraction time for obtain a maximum removal of PCB in the materials. The extractions for Soxhlet method were efficient for extraction of PCBs in soil and wood in both solvent studied (hexane and ethanol). In the experimental extraction in soils, the better efficient of removal of PCBs using ethanol as solvent was 81.3% than 95% for the extraction using hexane as solvent, for equal time of extraction. The results of the extraction with wood showed statistically it that there is not difference between the extractions in both solvent studied. The supercritical fluid extraction in the conditions studied showed better efficiency in the extraction of PCBs in the wood matrix than in soil, for two hours extractions the obtain percentual of 43.9 ? 0.5 % for the total of PCBs extracted in the soils against 95.1 ? 0,5% for the total of PCBs extracted in the wood. The results demonstrated that the extractions were satisfactory for both technical studied
A descontamina??o de materiais tem sido tema de v?rios estudos. Um dos fatores que aumenta a polui??o ? a falta de responsabilidade no descarte do lixo t?xico, como por exemplo, a presen?a de PCBs (Bifenilas policloradas) no meio ambiente. Nos regulamentos brasileiros, o material contaminado com PCBs nas concentra??es acima de 50 ppm deve ser armazenado em lugares especiais ou ser destru?do, geralmente por incinera??o em forno de plasma com duplo est?gio. Devido ao custo elevado deste processo, novas metodologias para remo??o de PCBs est?o sendo pesquisadas. O objetivo deste estudo foi desenvolver uma metodologia experimental e anal?tica para a quantifica??o da remo??o de PCBs de materiais contaminados atrav?s de extra??o pelo m?todo Soxhlet e por flu?do supercr?tico, como tamb?m avaliar e comparar a efici?ncia t?cnica dos dois processos de extra??o. Os materiais avaliados foram: solo e madeira ambos contaminados com PCBs via contamina??o simulada. Os materiais foram contaminados com a concentra??o de 6.000, 33.000 e 60.000 mg de ?leo Ascarel/ kg de material. A extra??o pelo m?todo Soxhlet foi realizada usando 100 mL de solvente org?nico (hexano ou etanol), 180 ?C e press?o atmosf?rica. A extra??o com flu?do supercr?tico foi realizada nas seguintes condi??es: 200 bar, 70 ?C e 3 g de CO2 / min. Os extratos obtidos foram quantificados usando a cromatografia gasosa acoplada a um espectr?metro de massa (CG-EM). Foram realizadas extra??es pelo m?todo convencional usando a t?cnica de planejamento fatorial 22, com a finalidade de estudar os efeitos da concentra??o inicial de contaminante e o tempo de extra??o no percentual de remo??o de PCBs. As extra??es pelo m?todo Soxhlet foi eficiente para extra??o de PCBs em solo e em madeira para os dois solventes em estudo (hexano e etanol). Nos experimentos de extra??o em solos, o melhor percentual de remo??o de PCBs usando etanol como solvente foi de 81,3% e 95% para a extra??o que usa hexano como solvente, com o mesmo tempo de extra??o. Os resultados dos ensaios de extra??o com madeira, mostraram que estatisticamente n?o h? diferen?a entre as extra??es mudando o solvente. A extra??o por fluido supercr?tico nas condi??es estudadas teve melhor desempenho para extrair PCBs na matriz madeira do que no solo. Em duas horas de extra??o foi obtido percentual de 43,9 ? 0,5 % para a soma do total de PCBs extra?do no solo contra 95,1 ? 0,5 % para a soma total de PCBs extra?do na madeira. Os resultados foram satisfat?rios para ambas as t?cnicas de extra??o estudadas
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Amaral, Gabriela Vieira do. "Whey drink de uva processado por di?xido de carbono supercr?tico: par?metros de qualidade e sensoriais." Universidade Federal Rural do Rio de Janeiro, 2017. https://tede.ufrrj.br/jspui/handle/jspui/2208.
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Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES
Emerging supercritical carbon dioxide (SCCD) technology has been studied as a cold pasteurizing agent, however, few studies are available on its efficiency in dairy products. In this study, the effects of SCCD processing by different pressures 14, 16 and 18 MPa (35 ? 2 ?C / 10 min) on whey drink, whey drink and grape juice were investigated in comparison To conventional pasteurization (heat treatment at 72 ?C / 15 s). Physicochemical analyzes of pH, titratable acidity, total soluble solids, phenolic compounds, anthocyanins, antioxidant activity, angiotensin converting enzyme (ACE) inhibitory activity and volatile compounds were performed. The color, particle size, rheology, physical stability, as well as microbiological quality and sensory analysis of beverages were also smoothed. The results of this study evidenced the absence of differences between treatments in pH, titratable acidity, soluble solids, total anthocyanins and DPPH activity (p> 0.05). A direct relationship between SCCD pressure and ACE inhibitory activity was observed, with 34.63, 38.75 and 44.31% (14, 16 and 18 MPa, respectively). Few differences were found in the volatile compounds profile. The beverage processing by SCCD resulted in a product with lower particle diameter, lower consistency index and a reduction in pseudoplastic character compared to the beverage treated by the conventional process. No effect of high pressure CO2 on the sensorial attributes of the drink was observed for the studied levels. Consumers found no difference between CO2 treated beverages and heat-treated beverages. The results confirm the processing of SCCD as a promising technology for the non-thermal treatment of grape whey drink made available a health and wellness promoter beverage. Background: Non-thermal food processing is configured as an interesting alternative for the food industry due to the increased nutrient retention and minimal sensory changes in processed products. Scope and approach: The aim of this review is to address the potential of supercritical carbon dioxide technology, emphasizing milk and dairy processing, including the historical aspects, main advantages, microbial inactivation mechanisms, as well as effects in some quality parameters of dairy products. Key findings and conclusions: The use of supercritical carbon dioxide technology (SC-CO2) presents great potential application in dairy processing, since it is effective to reduce microbial load when compared to the pasteurization process, thus obtaining a product with greater shelf life and better organoleptic properties with minimal and sometimes positive changes in the intrinsic quality parameters The effect of supercritical carbon dioxide technology (SCCD, 140, 160, and 180 bar at 35 ? 2 ?C for 10 min) on whey-grape juice drink characteristics was investigated. Physicochemical characterization (pH, titratable acidity, total soluble solids), bioactive compounds ( phenolic compunds, anthocyanins , DPPH and ACE activity) and the volatile compounds were performed. Absence of differences were found among treatments for pH, titratable acidity, soluble solids, total anthocyanins and DPPH activity (p>0.05). A direct relationship between SCCD pressure and ACE inhibitory activity was observed, with 34.63, 38.75, and 44.31% (140, 160, and 180 bar, respectively). Regards the volatile compounds, it was noted few differences except by the presence of ketones. The findings confirm the SCCD processing as a potential promising technology to the conventional thermal treatment. The use of supercritical technology as a non-thermal pasteurization process of the whey-grape juice drink was investigated in this study. The effects of supercritical carbon dioxide at 14, 16, and 18 MPa (35 ? 2?C/10 min) on the physical and sensory properties of the beverage, when compared to conventional pasteurization (heat treatment at 72?C/15 s) were evaluated. High-pressure CO2 processing of whey-grape juice drink resulted in a product with lower particle diameter, lower consistency index, and a reduction in pseudoplastic character when compared to the beverage treated by the conventional process. No effect of high-pressure CO2 was observed on the sensory attributes of the beverage for the levels studied. Consumers did not find differences between the CO2-treated and heat-treated beverages. Our findings suggest the use of supercritical technology with carbon dioxide as an effective alternative for the production and availability of a health and wellness promoting beverage
A tecnologia emergente de di?xido de carbono supercr?tico (DCSC) vem sendo estudada como agente pasteuriza??o a frio, no entanto, s?o poucos os estudos dispon?veis a cerca da sua efici?ncia em derivados l?cteos. Neste estudo, foram investigados os efeitos do processamento do DCSC por diferentes press?es 14, 16 e 18 MPa (35 ? 2 ?C / 10 min) no whey drink de uva, bebida a base de soro de leite e suco de uva, em compara??o ? pasteuriza??o convencional (tratamento t?rmico a 72 ?C / 15 s). Foram realizadas an?lises f?sico-quimicas de pH, acidez titul?vel, s?lidos sol?veis totais, compostos fen?licos, antocianinas, atividade antioxidante, atividade inibidora da enzima conversora de angiotensina (ECA) e compostos vol?teis. Tamb?m foramam alisados a cor, o tamanho de part?cula, reologia, estabilidade f?sica, assim como a qualidade microbiol?gica e analise sensorial das bebidas. Os resultados deste estudo evidenciaram a aus?ncia de diferen?as entre os tratamentos nas an?lises de pH, acidez titul?vel, s?lidos sol?veis, antocianinas totais e atividade de DPPH (p> 0,05). Foi observada uma rela??o direta entre press?o DCSC e atividade inibit?ria ACE, com 34,63, 38,75 e 44,31% (14, 16 e 18 MPa, respectivamente). Poucas diferen?as foram encontratdas no perfil dos compostos vol?teis. O processamento das bebidas por DCSC resultou em um produto com menor di?metro de part?cula, menor ?ndice de consist?ncia e uma redu??o no car?ter pseudopl?stico em compara??o com a bebida tratada pelo processo convencional. N?o foi observado efeito de CO2 de alta press?o nos atributos sensoriais da bebida para os n?veis estudados. Os consumidores n?o encontraram diferen?as entre as bebidas tratadas com CO2 e as bebidas tratadas termicamente. Os resultados confirmam o processamento do DCSC como uma tecnologia promissora para o tratamento n?o t?rmico de whey drink de uva disponibilizado uma bebida promotora de sa?de e bem-estar Antecedentes: Os processamentos de alimentos n?o t?rmicos s?o configurados como uma alternativa interessante para a ind?stria de alimentos devido ao aumento da reten??o de nutrientes e mudan?as sensoriais m?nimas nos produtos processados. ?mbito e abordagem: o objetivo desta revis?o ? abordar o potencial da tecnologia de di?xido de carbono supercr?tico, enfatizando o processamento de leite e l?cteos, incluindo os aspectos hist?ricos, as principais vantagens, os mecanismos de inativa??o microbiana, bem como os efeitos em alguns par?metros de qualidade dos produtos l?cteos. Principais conclus?es e conclus?es: o uso de tecnologia supercr?tica de di?xido de carbono (SC-CO2) apresenta grande potencial de aplica??o no processamento de l?cteos, uma vez que ? efetivo reduzir a carga microbiana quando comparado ao processo de pasteuriza??o, obtendo-se assim um produto com maior prateleira e melhores propriedades sensoriais com mudan?as m?nimas e ?s vezes positivas nos par?metros de qualidade intr?nseca. O efeito da tecnologia de di?xido de carbono supercr?tico (SCCD, 140, 160 e 180 bar a 35 ? 2 ?C durante 10 min) em caracter?sticas de bebidas de suco de uva foi investigado. Caracteriza??o f?sico-qu?mica (pH, acidez titul?vel, s?lidos sol?veis totais), compostos bioativos (compostos fen?licos, antocianinas, DPPH e atividade ACE) e os compostos vol?teis foram realizados. A aus?ncia de diferen?as foi encontrada entre tratamentos para pH, acidez titul?vel, s?lidos sol?veis, antocianinas totais e atividade de DPPH (p> 0,05). Foi observada uma rela??o direta entre press?o SCCD e atividade inibit?ria ACE, com 34,63, 38,75 e 44,31% (140, 160 e 180 bar, respectivamente). Atende aos compostos vol?teis, observou-se poucas diferen?as, exceto pela presen?a de cetonas. Os resultados confirmam o processamento do SCCD como uma potencial tecnologia promissora para o tratamento t?rmico convencional O uso da tecnologia supercr?tica como processo de pasteuriza??o a frio da bebida de suco de uva e soro de uva foi investigado neste estudo. Os efeitos do di?xido de carbono supercr?tico em 14, 16 e 18 MPa (35 ? 2 ?C / 10 min) nas propriedades f?sicas e sensoriais da bebida, quando comparados ? pasteuriza??o convencional (tratamento t?rmico a 72 ?C / 15 s) Foram avaliados. O processamento de CO2 de alta press?o da bebida de suco de soro de soro de leite resultou em um produto com menor di?metro de part?cula, menor ?ndice de consist?ncia e uma redu??o no car?ter pseudopl?stico em compara??o com a bebida tratada pelo processo convencional. N?o foi observado efeito de CO2 de alta press?o nos atributos sensoriais da bebida para os n?veis estudados. Os consumidores n?o encontraram diferen?as entre as bebidas tratadas com CO2 e as bebidas tratadas termicamente. Nossas descobertas sugerem o uso da tecnologia supercr?tica com di?xido de carbono como uma alternativa efetiva para a produ??o e disponibilidade de uma bebida promotora de sa?de e bem-estar
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Fianco, Ana Luisa Butelli. "Estudo sobre a atividade antif?ngica e antioxidante de extratos de pr?polis obtidos com CO2 supercr?tico." Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2014. http://tede2.pucrs.br/tede2/handle/tede/3255.
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Previous issue date: 2014-03-31Propolis is a resinous substance produced by bees through the collection of plant secondary metabolites and its chemical composition is complex and varied, giving this product several biological activities such as antibacterial, antifungal and antioxidant. The propolis extract can be obtained by supercritical fluid extraction using CO2 as solvent, which is a clean and non-toxic technology, leaving no residue. This work aims to extract chemically and biologically extracts of green and red propolis produced by bees of the species Apis mellifera. Supercritical CO2 extraction from the raw propolis and its ethanolic extracts, which were impregnated in filter papers, were performed. The pressures used for fractionation of raw propolis were 90, 120, 150, 200, 250 and 300 bar and, for the propolis impregnated in filter papers, 90, 150 and 300 bar. For comparison of the chromatographic profiles at different pressures, chemical analysis using Thin Layer Chromatography (TLC) and High Performance Liquid Chromatography (HPLC) were done. The chemical composition of the extracts from impregnated propolis ethanolic extracts (PEE) and raw propolis remained similar, but the yield of supercritical extracts from impregnated PEE in filter papers showed much higher values. Supercritical extracts showed antifungal activity and excellent antioxidant activity.
A pr?polis ? uma subst?ncia resinosa produzida pelas abelhas atrav?s da coleta de metab?litos secund?rios da flora e sua composi??o qu?mica ? complexa e variada, conferindo a este produto diversas atividades biol?gicas como antibacteriana, antif?ngica e antioxidante. O extrato da pr?polis pode ser obtido por extra??o supercr?tica, utilizando CO2 como solvente, sendo esta uma tecnologia limpa, at?xica e que n?o deixa res?duo. Este trabalho tem como objetivo extrair e avaliar quimicamente e biologicamente extratos de pr?polis verde e vermelha produzidos pelas abelhas da esp?cie Apis mellifera. Foram realizadas extra??es com CO2 supercr?tico a partir da pr?polis bruta e de seus extratos etan?licos, os quais foram impregnados em pap?is filtro. As press?es utilizadas para fracionamento da pr?polis bruta foram 90, 120, 150, 200, 250 e 300 bar, e da pr?polis impregnada em pap?is filtro, 90, 150 e 300 bar. Para compara??o dos perfis cromatogr?ficos nas diferentes press?es, an?lises qu?micas atrav?s de cromatografia em camada delgada (CCD) e cromatografia l?quida de alta efici?ncia (CLAE) foram realizadas. A composi??o qu?mica dos extratos a partir dos extratos etan?licos de pr?polis (EEP) impregnados e da pr?polis bruta permaneceu similar, por?m o rendimento dos extratos supercr?ticos a partir dos EEP impregnados em pap?is filtro apresentou valores muito mais elevados. Os extratos supercr?ticos obtidos apresentaram atividade antif?ngica e excelente atividade antioxidante.
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Brun, Gerti Weber. "Processo de produ??o de erva-mate descafeinada e de micro/nanopart?culas de cafe?na usando di?xido de carbono supercr?tico." Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2012. http://tede2.pucrs.br/tede2/handle/tede/3197.
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Previous issue date: 2012-03-30The decaffeination of leaves of yerba mate is economically attractive, since it allows to obtain products of commercial interest and caffeine, a byproduct used in food and pharmaceutical industries. In this work we used the extraction and precipitation with supercritical carbon dioxide to obtain the decaffeinated yerba mate and micro/nanoparticles of the caffeine. The decaffeinated yerba mate and extract were obtained from the dry leaves on automated pilot plant. The mathematical modeling was realized with the extraction curves defining the condition of the pressure and temperature for higher yield and lower caffeine content in yerba mate. For the micronization process based on the use of supercritical carbon dioxide as antisolvent (SAS process, Supercritical AntiSolvent) it was used a semi-continuous pilot plant. The influence of the initial concentration, the temperature and the pressure in the yield, in the particle size, in the morphology and polymorphism were analyzed. The results demonstrated that carbon dioxide is selective for caffeine and the condition which obtains higher yields of extract and less content of the caffeine in the extracted yerba mate was 15.0 MPa and 323,15 K . The average reduction of caffeine in yerba mate was 40%. The particles were micronized from caffeine solution with dichloromethaneand the analysis of the product showed a narrower range of sizes (2.5 to 6.5 μm) in comparison to unprocessed caffeine (12.2 μm) with an increment of the purity of caffeine. We also found that with proper selection of process parameters such as temperature, pressure and initial concentration, it is possible to produce particles of caffeine with different degrees of crystallinity and distinct quantities of polimorphics.
A descafeiniza??o de folhas de erva-mate ? economicamente atrativa, pois possibilita a obten??o de produtos descafeinados de interesse comercial e cafe?na, um bioproduto utilizado na ind?stria aliment?cia e farmac?utica. Neste trabalho utilizaram-se a extra??o e a precipita??o supercr?tica com di?xido de carbono para obten??o da erva mate descafeinada e de micro/nanopart?culas de cafe?na. A ervamate descafeinada e o extrato foram obtidos a partir da erva-mate seca em uma planta piloto automatizada. Com as curvas de extra??o procedeu-se a modelagem matem?tica definindo qual a condi??o de press?o e temperatura de extra??o para maior rendimento e menor teor de cafe?na na erva-mate. O processo de microniza??o baseou-se no uso do di?xido de carbono supercr?tico como antisolvente (processo SAS Supercritical Antisolvent) em uma planta piloto semicont?nua. A influ?ncia da concentra??o inicial, temperatura e press?o no rendimento, tamanho de part?cula, morfologia e polimorfismo foram analisados. Os resultados demonstraram que o di?xido de carbono ? seletivo para a cafe?na e que a condi??o em que se obt?m o maior rendimento de extrato e menor quantidade em massa de cafe?na na erva-mate extra?da ? a de 15,0 MPa e 323,15 K. A redu??o m?dia da cafe?na na erva-mate foi de 40%. As part?culas de cafe?na foram micronizadas a partir de solu??es com diclorometano. A an?lise do produto apresentou uma faixa mais estreita de tamanhos (2,5 a 6,5 μm) em compara??o com a cafe?na n?o processada (12,2 μm), com aumento de pureza da cafe?na. Foi encontrado tamb?m que com adequada sele??o dos par?metros do processo como temperatura, press?o e concentra??o inicial, ? poss?vel produzir part?culas de cafe?na com distintos graus de cristalinidade e diferentes quantidades dos polim?rficos.
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AGUIAR, Melise Ferreira. "Adsor??o de compostos sulfurados do g?s natural por diferentes adsorventes e dessor??o utilizando CO2 supercr?tico." Universidade Federal Rural do Rio de Janeiro, 2016. https://tede.ufrrj.br/jspui/handle/jspui/1614.
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2016 - Melise Ferreira de Aguiar.pdf: 5763969 bytes, checksum: 9dcc7682d7ffab0b0a6ce4d1db704c10 (MD5)Made available in DSpace on 2017-05-09T20:05:40Z (GMT). No. of bitstreams: 1 2016 - Melise Ferreira de Aguiar.pdf: 5763969 bytes, checksum: 9dcc7682d7ffab0b0a6ce4d1db704c10 (MD5) Previous issue date: 2016-12-12
CAPES
Natural gas is extensively used in industries as well as in other sectors as an energy resource and, sometimes, it needs to undergo processes for the removal of impurities present in its composition. Among them are the sulfur compounds, which can cause damages to pipes and catalysts, making it necessary to develop and/or improve deep desulfurization methods. In this context, granular activated carbon was modified through two methods, oxidation using nitric acid, and impregnation using a ferric chloride solution. The resulting adsorbents were evaluated for their capacity of adsorbing seven sulfur compounds present in the synthetic natural gas sample, through their rupture curves. Afterwards, the adsorbents desorption was performed by using supercritical carbon dioxide under the conditions of 60?C at 100 bar, 150 bar and 200 bar. The results indicate that all the modification methods improved the sulfur compounds retention when compared to virgin activated carbon. The compound that had the greatest increase in the adsorption capacity after iron impregnation was the tert-butyl mercaptan (TBM), and with the activated carbon oxidized by HNO3 it was the dimethyl sulfide (DMS). Nevertheless, the supercritical conditions studied in the desorption stage were efficient only for the unmodified activated carbon. The adsorption capacities of both modified adsorbents after the regeneration were inferior to those capacities obtained in the first adsorption, then two hypotheses were investigated: (1) destruction of the newly created sites after regeneration; and (2) incomplete desorption in the studied supercritical conditions. Through other experiments it was proved that, after regeneration, there was no destruction of the newly created sites; therefore, further studies on the operating conditions are required in order to the modified adsorbents to achieve high regeneration capacities.
O g?s natural ? utilizado nas ind?strias e em outros setores como fonte de energia e necessita, por vezes, de processos de remo??o das impurezas presentes em sua composi??o. Dentre elas est?o os compostos de enxofre, que provocam danos em tubula??es e catalisadores, sendo necess?rio o desenvolvimento e/ou o aperfei?oamento de m?todos para a dessulfuriza??o profunda. Nesse contexto, um carv?o ativado granular foi modificado por meio de dois m?todos, oxida??o utilizando ?cido n?trico e por impregna??o usando uma solu??o de cloreto de ferro III, os adsorventes resultantes foram avaliados quanto ? sua capacidade para adsorver sete compostos de enxofre presentes em uma amostra de g?s natural sint?tica, atrav?s das curvas de rupturas. Posteriormente, foi realizada a dessor??o dos adsorventes utilizando di?xido de carbono supercr?tico nas condi??es de 60 ?C a 100 bar, 150 bar e 200 bar. Os resultados indicam que todos os m?todos de modifica??o melhoraram a reten??o dos compostos sulfurados individuais em compara??o com o carv?o ativado virgem. O composto que obteve maior aumento da capacidade de adsor??o ap?s a impregna??o com ferro foi o terc-butilmercaptana (TBM), e com o carv?o ativado oxidado pelo HNO3 foi o metiletilsulfeto (DMS). J? as condi??es supercr?ticas estudadas na etapa de dessor??o foram eficientes somente para o carv?o ativado n?o modificado. As capacidades de adsor??o dos dois adsorventes modificados ap?s a regenera??o foram inferiores aos obtidos na primeira adsor??o, ent?o duas hip?teses foram investigadas: (1) destrui??o dos novos s?tios criados ap?s a regenera??o; e (2) dessor??o incompleta nas condi??es supercr?ticas estudadas. Atrav?s de outros experimentos comprovou-se que n?o houve ? destrui??o dos novos s?tios criados ap?s a regenera??o, sendo necess?rio um estudo mais profundo em rela??o ?s condi??es operacionais, a fim de alcan?ar altas capacidades de regenera??o dos adsorventes modificados.
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SARTORI, Roberta Benic? "Extra??o de agrot?xicos presentes na banana vit?ria (Musa spp) usando CO2 supercr?tico: Experimental e modelagem." Universidade Federal Rural do Rio de Janeiro, 2017. https://tede.ufrrj.br/jspui/handle/jspui/1952.
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Banana is a tropical fruit cultivated in warm places and harvested during the whole year, as well as its consumption is intense. It is known that banana productivity, however, is threatened due to the vulnerability of the cultivars to some pests and diseases. Because of this, some agrochemicals are recommended to avoid the attack of these hindrances such as: azoxystrobin, chlorothalonil, diphenoconazole, imazalil, bifenthrin, and chlorpyriphos. All of them can cause serious health problems in humans such as cancer and neurological diseases and adverse reproductive effects are associated with the consumption and/or exposure to these hazardous substances. However, even when applied in conformity with Good Agricultural Practices, pesticides can leave residues, that can still be present in the soils as well as in the fruits. Due to these considerations, this study has as aim the technical evaluation of supercritical fluid in the extraction of pesticides present in banana flour (Musa spp). Therefore, the whole fruits (8 g), previously submitted to lyophilization and milling were fortified, during a stable period of overnight, with a solution containing the agrochemical standards mentioned above, diluted in methanol. The experimental unit consisted basically of a 42 mL extractor, a high pressure pump and a micrometering valve to sample removal. Different operational conditions were investigated (60 ?C ? 200 bar; 46 ?C ? 244 bar; 74 ?C ? 244 bar; 40 ?C ? 350 bar; 60 ?C ? 350 bar; 80 ?C ? 350 bar; 46 ?C ? 456 bar; 74 ?C ? 456 bar and 60 ?C ? 500 bar) based on an experimental design. The analysis of the extracted pesticides was performed using an ultra performance liquid chromatography coupled to a mass spectrometer (UPLC-MS). It was observed that the yield of the extract increased with the temperature increasing. According to the results, the extraction at 80 ?C and 350 bar was able to remove 1.4194% of the extracts in the banana. The yield of pesticides increased with the pressure increasing and the better condition was at 500 bar and 60 ?C. The experimental data were well modelled by the models of Esqu?vel et al. (1999), Reverchon & Osseo (1994), Zekovi? et al. (2003) and Sovov? (1999). The Chrastil (1982) model could represent the solubility behavior of the pesticides with the variation of temperature and pressure.
A banana ? uma fruta tropical cultivada em locais quentes e colhida durante todo o ano, assim como seu consumo ? intenso durante todo o ano. Sabe-se que a produtividade da banana, no entanto, est? amea?ada devido ? vulnerabilidade de tais cultivares a algumas pragas e doen?as. Devido a isso, alguns agroqu?micos s?o recomendados para evitar o ataque destes entraves ? produtividade da banana, tais como: azoxistrobina, clorotalonil, difenoconazol, imazalil, bifentrina e clorpirifos. Todos esses compostos podem causar s?rios problemas de sa?de em seres humanos, como o c?ncer, assim como doen?as neurol?gicas e efeitos reprodutivos adversos est?o associados ? ingest?o e/ou exposi??o a estas subst?ncias perigosas. No entanto, mesmo quando aplicados em conformidade com as Boas Pr?ticas Agr?colas, os pesticidas podem deixar res?duos, que ainda podem estar presentes tanto nos solos como nos frutos. Devido a estas considera??es, este estudo tem como objetivo a avalia??o t?cnica do fluido supercr?tico na extra??o de agrot?xicos presentes na farinha de banana (Musa spp). Assim, os frutos inteiros (8 g), previamente submetidos ? liofiliza??o e moagem foram fortificados, durante um per?odo est?vel de um dia para o outro, com uma solu??o contendo os padr?es dos pesticidas mencionados acima, dilu?dos em metanol. A unidade experimental consiste basicamente em um extrator de 42 mL, uma bomba de alta press?o e uma v?lvula microm?trica para remo??o da amostra. Foram investigadas diferentes condi??es operacionais (60 ?C a 200 bar, 46 ?C a 244 bar, 74 ?C a 244 bar, 40 ?C a 350 bar, 60 ?C a 350 bar, 80 ?C a 350 bar, 46 ?C a 456 bar e 74 ?C - 456 bar e 60 ?C - 500 bar) com base em um planejamento experimental. A an?lise dos pesticidas extra?dos foi realizada utilizando cromatografia l?quida de ultra desempenho acoplada ao espectr?metro de massa (UPLC-MS). Observou-se que o rendimento do extrato aumentou com o aumento da temperatura. De acordo com os resultados, a extra??o a 80 ?C e 350 bar foi capaz de remover 1,4194% dos extratos na banana. Para o rendimento de pesticidas, observou-se um aumento com o aumento da press?o e a melhor condi??o foi a 500 bar e 60 ?C. Os dados experimentais foram modelados pelos modelos de Esqu?vel et al. (1999), Reverchon & Osseo (1994), Zekovi? et al. (2003) e Sovov? (1999), apresentando boa correla??o. O modelo de Chrastil (1982) conseguiu representar o comportamento da solubilidade dos agrot?xicos com a varia??o de temperatura e press?o.
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Fau, Amaury. "Spectroscopies Raman et de luminescence résolues en temps pour l'exploration de Mars." Electronic Thesis or Diss., Sorbonne université, 2019. http://www.theses.fr/2019SORUS101.
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En 2021, le rover Mars 2020 de la NASA déploiera l’instrument SuperCam dans le cratère Jezero sur Mars. Cet instrument franco-américain multi-techniques d'analyse à distance sera équipé notamment d’un LIBS (analyse chimique) et d’un spectromètre Raman et de luminescence résolu en temps (analyse minéralogique). Après étude de paramètres environnementaux ainsi que de facteurs intrinsèques à l’échantillon cible, la spectroscopie Raman résolue en temps s’avère très puissante et permet la réalisation de spectres Raman dépourvus de signaux parasites (e.g. luminescence) pour de nombreux minéraux (carbonates, phosphates, silicates) parfois non analysables en Raman conventionnel. Une base de données de spectres Raman résolu en temps a ainsi été élaborée. Les effets de tirs laser LIBS sur la structure et la signature Raman de nombreux minéraux ont été étudiés sur la base d’expériences et de modélisations thermiques simples. Les résultats montrent un effet majeur (vitrification voire transition de phase) pour des minéraux opaques à fort coefficient d'absorption optique alors que les effets sont minimes, voire non détectables, pour des phases plus transparentes. Ces résultats sont discutés en termes de contraintes opérationnelles pour les instruments du rover Mars2020. L’étude de la luminescence des terres rares dans des apatites synthétiques dopées et naturelles montre que la luminescence est un outil pertinent de détection de ces éléments. En revanche, l’étude des temps de décroissance met en évidence des phénomènes complexes de transferts d’énergie entre centres émetteurs et limite l’utilisation de ces temps de décroissance pour une éventuelle quantification des terres raresIn 2021, the NASA Mars 2020 rover will deploy the SuperCam instrument in the Jezero crater on Mars. This franco-american multi-tool instrument for remote analysis will be equiped with LIBS (chemical analysis) and with a time-resolved Raman and luminescence spectrometer (mineralogical analysis). After investigating various environmental parameters as well as intrinsic factors from the target sample, time-resolved Raman spectroscopy appears as a powerful tool to obtain high-quality Raman spectra free of parasitic signal (e.g. luminescence) for many mineral phases (carbonates, phosphates, silicates), even in the case of minerals hardly analysable with conventional Raman. A database of time-resolved Raman spectra has been elaborated. The effects of LIBS laser shots on the mineral structure and Raman fingerprint have been studied experimentally and through simple thermal modeling. Results show a major structural effect (vitrification and/or phase transition) in the case of opaque minerals with high optical absportion coefficient whereas the effects are minimal, or even non detectable, for more transparent and less absorbing minerals. Implications of these results for the operation of the Mars 2020 instruments are discussed. The study of Rare-Earth Elements (REE) luminescence in synthetic doped and natural apatites shows that luminescence is powerful to detect and characterize REEs. However, due to strong transfer energy among emission centers, the possible use of luminescence lifetime appears to be impossible to quantify REE in natural apatites
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Dalla, Vecchia Felipe. "Avalia??o da degrada??o por CO2 supercr?tico da pasta de cimento empregada em po?os de petr?leo." Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2009. http://tede2.pucrs.br/tede2/handle/tede/3130.
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Previous issue date: 2009-03-20Nos ?ltimos anos, a preocupa??o mundial com a quest?o da emiss?o de gases de efeito estufa para a atmosfera tem se intensificado, particularmente relacionada ?s emiss?es do g?s CO2. O desenvolvimento de tecnologias para mitiga??o de gases de efeito estufa ? apontado como uma resposta adequada para conter o aquecimento global e o seq?estro geol?gico de carbono destaca-se como uma das tecnologias mais importantes, em curto prazo, para este fim. Nesse cen?rio, os campos de explora??o de petr?leo maduros ou abandonados apresentam grande viabilidade para armazenamento de CO2. A integridade do cimento classe G, que foi desenvolvido para ser utilizado na constru??o de po?os de petr?leo, deve ser mantida para evitar que o CO2 escape pelo po?o para a atmosfera. Contudo, esse material pode sofrer degrada??o pelo meio ?cido produzido pelo CO2 na presen?a de ?gua das forma??es geol?gicas. Para avaliar a resist?ncia da pasta de cimento frente ao CO2 supercr?tico foi desenvolvido um sistema experimental constitu?do de reatores que simulam as condi??es encontradas em prov?veis s?tios de armazenamento geol?gico de CO2. Dessa forma, corpos-deprova de pasta de cimento classe G foram submetidos a dois meios de degrada??o ao longo do tempo, CO2 supercr?tico ?mido e ?gua saturada com CO2, nas condi??es de temperatura e press?o de 150?C e 15 MPa, respectivamente. As pastas de cimento foram caracterizadas por meio de medidas de pH, microscopia eletr?nica de varredura (MEV), microscopia ?ptica; microdureza Vickers e ensaios de resist?ncia ? compress?o. Os resultados obtidos indicaram que o CO2 supercr?tico ?mido e CO2 dissolvido em ?gua promovem altera??es na microestrutura e propriedades mec?nicas da pasta de cimento, sendo que a degrada??o ? mais severa no caso da ?gua saturada com CO2.
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Garcez, Jos? Jacques. "Obten??o do extrato vol?til de sementes de Anethum graveolens L. por diferentes t?cnicas extrativas." Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2016. http://tede2.pucrs.br/tede2/handle/tede/6963.
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This master thesis aimed the study of different extraction techniques and the influence of different particle sizes in maximizing the yield of essential oil from the seeds of dill, an herb widely used in cooking and in traditional folk medicine and has a wide range of properties conferred such as antimicrobial, antibacterial and antioxidant. The techniques used for obtaining the essential oil were extracted by steam distillation and hydrodistillation, where different average particle sizes of crushed seed and anise were considered, and extraction with supercritical carbon dioxide, where besides the variation of average particle sizes it was used different pressure values. For the supercritical extraction, it was then used the response surface method in which the variables pressure and average particle diameter were investigated, also a 2? factorial design was used to determine the number of experiments required. The best conditions for the three extractive methods were found, being larger diameters of particles to steam distillation and hydrodistillation, and 10,000 kPa and smaller diameter particles to the supercritical extraction. In this evaluation, it was performed mathematical modeling of the yield versus time curves of the best extraction conditions for each of the techniques. The extracts were analyzed in a gas chromatograph coupled to a mass spectrometer, after, the results have undergone a statistical analysis of major components, which were divided into 3 different groups according to their similar compositions. Finally, its antibacterial activities were tested where all extracts showed activity against E. coli.
Este trabalho tem como objetivo o estudo sobre algumas diferentes t?cnicas de extra??o e a influ?ncia de diferentes granulometrias na maximiza??o do rendimento do ?leo essencial das sementes do endro, uma erva utilizada na culin?ria e na medicina popular tradicional e que possui uma ampla gama de propriedades atribu?das tais como atividade antibacteriana, antif?ngica e antioxidante. As t?cnicas realizadas para a obten??o do ?leo essencial foram: extra??o por arraste a vapor e hidrodestila??o, onde diferentes tamanhos m?dios das part?culas de sementes mo?das do endro foram considerados, e extra??o com di?xido de carbono supercr?tico, onde al?m da varia??o dos tamanhos m?dios das part?culas, foram empregados diferentes valores de press?es. Para a extra??o supercr?tica, foi ent?o utilizado o m?todo de superf?cie de respostas onde as vari?veis, press?o e di?metro m?dio de part?culas foram investigados, tamb?m, um planejamento fatorial 2? foi aplicado para determinar a quantidade de experimentos necess?rios. As melhores condi??es nos tr?s m?todos extrativos foram encontradas, sendo maiores di?metros de part?culas para o arraste a vapor e a hidrodestila??o e 10.000 kPa e menor di?metro de part?culas para a extra??o supercr?tica. Al?m desta avalia??o, foram realizadas modelagens matem?ticas das curvas de rendimento versus tempo das melhores condi??es de extra??o referente a cada uma das t?cnicas. Os extratos foram analisados em um cromat?grafo a g?s acoplado a um espectr?metro de massas, ap?s, os resultados passaram por uma an?lise estat?stica de componentes principais, onde foram divididos em tr?s diferentes grupos de acordo com suas semelhantes composi??es. Por fim, suas a??es antibacterianas foram testadas onde todos os extratos apresentaram atividade frente a E. coli.
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Santos, Rog?rio Pitanga. "Extra??o, caracteriza??o e avalia??o bioativa do extrato de Arrabidaea chica." Universidade Federal do Rio Grande do Norte, 2015. http://repositorio.ufrn.br/handle/123456789/20164.
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Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq
A utiliza??o de plantas com finalidades medicinais ? milenar, sendo bastante difundida sua aplica??o em medicamentos. Apesar das plantas serem fontes promissoras para a descoberta de novas mol?culas de interesse farmacol?gico, estimativas revelam que apenas 17% delas foram estudadas quanto a sua possibilidade de uso na medicina. Assim, a biodiversidade da flora brasileira representa um imenso potencial de utiliza??o econ?mica pela ind?stria farmac?utica. A planta Arrabidaea chica, popularmente conhecida como ?pariri?, ? comum na regi?o Amaz?nica, e a ela s?o atribu?das v?rias propriedades medicinais. As folhas desta planta s?o ricas em antocianinas, que s?o compostos fen?licos com alto poder antioxidante. Os compostos antioxidantes desempenham um papel vital na preven??o de doen?as neurol?gicas e cardiovasculares, c?ncer e diabetes, entre outras. Dentre as antocianinas encontradas na Arrabidaea chica, destaca-se a Carajurina (6,7-dihidroxi-5,4?- dimetoxi-flavilium), que ? o principal pigmento encontrado nesta planta. O presente trabalho teve como objetivo geral o estudo sobre a extra??o supercr?tica e a extra??o convencional (s?lido-l?quido) de folhas da Arrabidaea chica, avaliando-se o rendimento dos processos extrativos, a atividade antioxidante e a quantifica??o de Carajurina contida nos extratos. As extra??es supercr?ticas utilizaram CO2 como solvente, adicionado de co-solvente (mistura etanol/?gua), e foram conduzidas pelo m?todo din?mico em um extrator de leito fixo. Os ensaios obedeceram a um planejamento fatorial fracion?rio 24-1, tendo como vari?veis resposta o rendimento do processo, o poder antioxidante e a concentra??o de Carajurina, e como vari?veis independentes a press?o, a temperatura, a concentra??o de co-solvente (v/v) e a concentra??o de ?gua no co-solvente (v/v). Os rendimentos (massa de extrato seco/massa de mat?ria-prima utilizada) obtidos da extra??o supercr?tica variaram de 15,1% a 32%, sendo que o melhor resultado foi obtido a 250 bar e 40?C, com uso do co-solvente a 30% (v/v) e concentra??o de ?gua no co-solvente igual a 50% (v/v). Atrav?s de an?lise estat?stica, verificou-se que a concentra??o de co-solvente apresentou efeito significativo sobre o rendimento. Os resultados de rendimento em massa para as extra??es convencionais foram de 8,1% (?gua) e 5,5% (etanol). Atrav?s de an?lises cromatogr?ficas em CLAE (Cromatografia L?quida de Alta Efici?ncia), a Carajurina foi quantificada em todos os extratos obtidos e os valores de concentra??o (massa de Carajurina/massa de extrato seco) variaram entre 1% e 2,21% para os extratos supercr?ticos. Quanto ?s extra??es convencionais, n?o foi detectada Carajurina no extrato aquoso, enquanto o extrato etan?lico apresentou teor de Carajurina igual a 7,04%, sendo, portanto, mais seletivo em Carajurina do que as extra??es supercr?ticas. A avalia??o do poder antioxidante (m?todo do sequestro do radical 2,2-difenil-1-picril-hidrazilDPPH) dos extratos supercr?ticos resultou em valores de EC50 (concentra??o efetiva que neutraliza 50% dos radicais livres) compreendidos entre 38,34 e 86,13 ?g/mL, enquanto que as extra??es convencionais resultaram em valores de EC50 de 167,34 (?gua) e 42,58 (etanol) ?g/mL. J? a quantifica??o dos compostos fen?licos (m?todo espectrofotom?trico de FolinCiocalteau) dos extratos supercr?ticos resultou em valores compreendidos entre 48,93 e 88,62 mg EAG/g extrato (EAG = Equivalentes de ?cido G?lico), enquanto que as extra??es s?lidol?quido resultaram em valores de 37,63 (?gua) e 80,54 (etanol) mg EAG/g extrato. A boa atividade antioxidante pode ser atribu?da n?o somente ? presen?a de Carajurina, mas tamb?m ? exist?ncia de outros compostos fen?licos e antioxidantes na Arrabidaea chica. Atrav?s da otimiza??o do planejamento experimental, foi poss?vel identificar o experimento que apresentou o melhor resultado considerando as quatro vari?veis resposta em conjunto. Este experimento foi realizado nas seguintes condi??es: press?o de 200 bar, temperatura de 40?C, concentra??o de co-solvente igual a 30% (v/v) e concentra??o de ?gua no co-solvente igual a 30% (v/v). Conclui-se que, dentro da faixa estudada, ? poss?vel obter o resultado ?timo utilizando condi??es operacionais mais amenas, o que implica em menores custos e maior facilidade de opera??o.
The use of plants for medicinal purposes is ancient, with widespread application in medicinal drugs. Although plants are promising sources for the discovery of new molecules of pharmacological interest, estimates show that only 17% of them have been studied for their possible use in medicine. Thus, biodiversity of Brazilian flora represents an immense potential for economic use by the pharmaceutical industry. The plant Arrabidaea chica, popularly known as ?pariri?, is common in the Amazon region, and it is assigned several medicinal properties. The leaves of this plant are rich in anthocyanins, which are phenolic compounds with high antioxidant power. Antioxidant compounds play a vital role in the prevention of neurological and cardiovascular diseases, cancer and diabetes, among others. Within the anthocyanins found in Arrabidaea chica, stands out Carajurin (6,7-dihydroxy-5,4?- dimethoxy-flavilium), which is the major pigment encountered in this plant. The present work aimed to study on supercritical extraction and conventional extraction (solid-liquid extraction) in leaves of Arrabidaea chica, evaluating the efficiency of the extractive processes, antioxidant activity and quantification of Carajurin contained in the extracts. Supercritical extraction used CO2 as solvent with addition of co-solvent (ethanol/water mixture) and were conducted by the dynamic method in a fixed bed extractor. The trials followed a 24-1 fractional factorial design, the dependent variables were: process yield, concentration of Carajurin and antioxidant activity; and independent variables were: pressure, temperature, concentration of co-solvent (v/v) and concentration of water in the co-solvent mixture (v/v). Yields (mass of dry extract/mass of raw material used) obtained from supercritical extraction ranged from 15.1% to 32%, and the best result was obtained at 250 bar and 40 ?C, co-solvent concentration equal to 30% and concentration of water in the co-solvent mixture equal to 50%. Through statistical analysis, it was found that the concentration of co-solvent revealed significant effect on the yield. Yields obtained from conventional extractions were of 8.1% (water) and 5.5% (ethanol). Through HPLC (High-performance liquid chromatography) analysis, Carajurin was quantified in all the extracts and concentration values (Carajurin mass/mass of dry extract) ranged between 1% and 2.21% for supercritical extraction. For conventional extraction, Carajurin was not detected in the aqueous extract, while the ethanol extract showed Carajurin content of 7.04%, and therefore, more selective in Carajurin than the supercritical extraction. Evaluation of antioxidant power (radical 2,2-diphenyl-1-picrylhydrazyl ? DPPH ? sequestration method) of the supercritical extracts resulted in EC50 values (effective concentration which neutralizes 50% of free radicals) ranged from 38.34 to 86.13 ?g/mL, while conventional extraction resulted in EC50 values of 167.34 (water) and 42.58 (ethanol) ?g/mL. As for the quantification of total phenolic content (Folin-Ciocalteau analysis) of the supercritical extracts resulted in values ranged from 48.93 and 88.62 mg GAE/g extract (GAE = Gallic Acid Equivalents), while solid-liquid extraction resulted in values of 37.63 (water) and 80.54 (ethanol) mg GAE/g extract. The good antioxidant activity cannot be attributed solely to the presence of Carajurin, but also the existence of other compounds and antioxidants in Arrabidaea chica. By optimizing the experimental design, it was possible to identify the experiment that presented the best result considering the four dependent variables together. This experiment was performed under the following conditions: pressure of 200 bar, temperature of 40 ?C, co-solvent concentration equal to 30% and concentration of water in the co-solvent mixture equal to 30%. It is concluded that, within the studied range, it is possible to purchase the optimum result using milder operating conditions, which implies lower costs and greater ease of operation.
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Royer, Clément. "Etude des performances des spectromètres miniatures infrarouge à base d'AOTF Pre-launch radiometric calibration of the infrared spectrometer onboard SuperCam for the Mars2020 rover." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASP085.
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Depuis une vingtaine d'années, la spectroscopie de réflectance proche-infrarouge appliquée à la planétologie a révolutionné notre vision des surfaces planétaires, grâce notamment à la découverte de phyllosilicates à la surface de Mars par les instruments OMEGA (Observatoire pour la Minéralogie, l'Eau, les Glaces et l'Activité) à bord de la sonde européenne Mars Express, et CRISM (Compact Reconnaissance Infrared Spectrometer for Mars) embarqué sur la sonde Mars Reconnaissance Orbiter, en 2005 et 2007. Ces deux missions spatiales ont ouvert la voie à l'étude approfondie de toutes les surfaces planétaires dans le proche-infrarouge (entre 1 et 5 µm), à la recherche de leur composition minéralogique et des processus d'altération passés et présents.Dans l'optique d'équiper toute sonde interplanétaire, voire même in-situ, avec des spectromètres proche-infrarouge, il est nécessaire de développer une nouvelle génération d'instruments à la fois compacts et performants. L'AOTF (Acousto-Optic Tunable Filter) utilisé en tant que monochromateur est une technologie-clé sur laquelle pourront s'appuyer ces instruments. Les deux spectromètres au coeur de ma thèse, IRS (Infrared Spectrometer) équipant l'instrument combiné SuperCam à bord du rover Perseverance, et ExoCam, au stade de R&T à l'Institut d'Astrophysique Spatiale, exploitent le potentiel de ce composant pour produire des données scientifiques de haute qualité avec un volume réduit.Ma thèse a ainsi contenu deux volets principaux : la préparation et la réalisation de l'étalonnage radiométrique des modèles de vol et de qualification de IRS/SuperCam, et le développement d'un simulateur d'observations infrarouge pour les futures opérations du rover Perseverance d'une part ; et l'étude des performances de l'imagerie hyperspectrale proche-infrarouge utilisant l'AOTF en transmission avec le programme de R&T ExoCam, accompagnée du développement d'un modèle radiométrique du banc de R&T permettant de projeter les résultats obtenus sur table à de futures opérations dans l'espaceDuring the past 20 years, reflectance near-infrared spectroscopy applied to planetary exploration has brought a new sight on planetary surfaces, mainly thanks to the discovery of Martian phyllosilicates by OMEGA (Observatoire pour la Minéralogie, l'Eau, les Glaces et l'Activité) on-board the European probe Mars Express, and CRISM (Compact Reconnaissance Infrared Spectrometer for Mars) equipping the probe Mars Reconnaissance Orbiter, in 2005 and 2007. These two space missions have paved the way to the thorough study of the surface of planetary bodies in the near-infrared (between 1 and 5 µm), searching for their mineral composition and past/present alteration processes.In order to board a infrared spectrometer in every interplanetary, and even in-situ probes, it is necessary to design a new generation of instruments both compact and efficient. The AOTF-based (Acousto-Optic Tunable Filter) monochromator is a key technology to fulfill this objective. The two spectrometers studied in the frame of my PhD thesis, IRS (Infrared Spectrometer) on-board the SuperCam instrument on Perseverance rover, and ExoCam, in R&T at the IAS (Institut d'Astrophysique Spatiale), benefit from this subsystem to produce high quality science data with a small volume occupation.My PhD thesis has been thus divided in two main parts: the preparation and performance of the radiometric calibration of the IRS/SuperCam qualification and flight models, and the design of an infrared observation simulator for the future Perseverance operations; the study of the performance of hyperspectral near-infrared imagery using an AOTF in transmission, throught the ExoCam R&T program, along with the development of a radiometric model of the R&T breadboard allowing to extrapolate lab results to future space operations
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Pereira, Marcos Aur?lio Almeida. "Estudo da atividade antimicrobiana de ?leos essenciais extra?dos por destila??o por arraste a vapor e por extra??o supercr?tica." Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2010. http://tede2.pucrs.br/tede2/handle/tede/3156.
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Previous issue date: 2010-03-23A utiliza??o de ?leos essenciais na pesquisa sobre a atividade antimicrobiana ? bastante intensa e tem aumentado a cada ano. Por?m, a influ?ncia do processo de extra??o na composi??o qu?mica dos ?leos essenciais e o impacto da intera??o de seus compostos na atividade antimicrobiana t?m sido menos estudados. Os ?leos essenciais de Rosmarinus officinalis L. e Cymbopogum winterianus Jowitt foram extra?dos por arraste a vapor e por extra??o supercr?tica. O processo de extra??o influenciou diretamente na composi??o qu?mica dos ?leos e conseq?entemente na atividade antimicrobiana. O ?leo de Cymbopogum citratus DC. Stapf. foi extra?do por arraste a vapor e durante a avalia??o da atividade antimicrobiana, o composto citral apresentou uma forte atividade. A atividade antimicrobiana dos ?leos estudados foi avaliada pelo m?todo de bioautografia indireta que permite a separa??o da composi??o qu?mica dos ?leos em fra??es, as quais foram analisadas por cromatografia gasosa acoplada a um espectr?metro de massa (GC-MS). A concentra??o inibit?ria m?nima dos ?leos Cymbopogum citratus DC. Stapf. e Cymbopogum winterianus Jowitt, os quais foram ativos contra os microorganismos citados na Portaria 15 da ANVISA de 1988, foi determinada pelo m?todo de dilui??o em tubos. Al?m disto, as dilui??es em tubos foram plaqueadas, por al?a calibrada, a fim de se verificar seu efeito bacteriost?tico ou bactericida.
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Franceschini, Gustavo do Nascimento. "Avalia??o do efeito das vari?veis de processo na descafeiniza??o da erva-mate por extra??o com fluido supercr?tico." Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2017. http://tede2.pucrs.br/tede2/handle/tede/7392.
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Submitted by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-06-29T13:46:52Z
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DIS_GUSTAVO_DO_NASCIMENTO_FRANCESCHINI_COMPLETO.pdf: 1349176 bytes, checksum: 447176549ff68fd480d9db42406285d0 (MD5)Made available in DSpace on 2017-06-29T13:46:52Z (GMT). No. of bitstreams: 1 DIS_GUSTAVO_DO_NASCIMENTO_FRANCESCHINI_COMPLETO.pdf: 1349176 bytes, checksum: 447176549ff68fd480d9db42406285d0 (MD5) Previous issue date: 2017-03-30
Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES
Conselho Nacional de Pesquisa e Desenvolvimento Cient?fico e Tecnol?gico - CNPq
The caffeine extraction process of yerba mate presents itself as an economically attractive activity, capable of generating two products with high market value, decaffeinated yerba mate, a differentiated product and natural caffeine, a compound with a growing demand in the current market. The purpose of this study was to evaluate the effect of the properties of plant material and the effect of process operating conditions in the caffeine removal from mate through supercritical extraction. To this objective, supercritical carbon dioxide extraction technology was used. The studied characteristics of the plant material were particle size, density and moisture content. After the optimum parameters were defined, the effect of the processing to which yerba mate is submitted was also evaluated, in three different stages: harvesting, zapecado and cancheamento. As for the operating conditions, it was assessed the influence of the porosity and the cosolvent content (ethanol) during the extraction process, with the pressure and operating temperature were set at optimum values for the removal of caffeine. Still, the effect of the mass ratio plant / solvent weight used was also studied. The extracts were analyzed by highperformance liquid chromatography. It was observed that increasing water content present in plant favored removal of caffeine, reaching a final concentration of 0.30% of caffeine (g / 100g), while the use of ethanol as cosolvent during the extraction process yielded in a final concentration of 0.03% (g / 100g) caffeine. For the processing, the zapecada sample presented the best results overall, both in yield of extract obtained and caffeine removal. Regarding the biological activity of the decaffeinated product, it was verified that the infusions of yerba mate decreased the cell viability of different cell lines of esophageal cancer and that this effect was independent of the concentration of caffeine present in the plant. Finally, the mathematical modeling of the extraction curve was performed in order to correlate the variables of the process with the experimental data.
O processo de extra??o de cafe?na da erva-mate apresenta-se como uma atividade economicamente atrativa, capaz de gerar dois produtos com alto valor de mercado, a erva-mate descafeinada, um produto diferenciado e a cafe?na natural, composto com uma crescente demanda no mercado atual. A proposta deste trabalho foi avaliar o efeito das propriedades do material vegetal e das condi??es operacionais de processo de extra??o na remo??o da cafe?na da erva-mate. Para isto, utilizou-se a tecnologia de extra??o supercr?tica. As propriedades do material vegetal estudadas foram granulometria, densidade e teor de umidade. Ap?s definirem-se os par?metros ?timos, avaliou-se o efeito do processamento da ervamate em tr?s diferentes etapas na melhor condi??o: fresca, sapecada e cancheada. Quanto ?s condi??es de opera??o, avaliou-se a influ?ncia da porosidade e do teor de cossolvente (etanol) durante o processo de extra??o, com a press?o e a temperatura de opera??o sendo fixadas em valores ?timos para a remo??o de cafe?na. Ainda, verificou-se o efeito da raz?o massa de planta/massa de solvente utilizado. Os extratos foram analisados por cromatografia l?quida de alta efici?ncia. Como resultado deste estudo observou-se que o aumento do teor de umidade presente na planta favoreceu a remo??o de cafe?na, atingindo uma concentra??o final de 0,30% de cafe?na (g/100g), enquanto que a utiliza??o de etanol como cossolvente durante o processo de extra??o resultou em uma concentra??o final de 0,03% (g/100g) de cafe?na. Para o processamento, a amostra sapecada apresentou os melhores resultados, tanto em rela??o ao rendimento de extrato obtido como em rela??o ? remo??o de cafe?na. Quanto ? atividade biol?gica do produto descafeinado, verificou-se que as infus?es de erva-mate diminuem a viabilidade celular de diferentes linhagens celulares de c?ncer de es?fago e que este efeito ? independente da concentra??o de cafe?na na planta. Por fim, procedeu-se a modelagem matem?tica da curva de extra??o a fim de correlacionar as vari?veis de processo com os dados experimentais.
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Azev?do, Saulo Henrique Gomes de. "Produ??o de biodiesel em reator de fluxo cont?nuo a partir do ?leo de algod?o em condi??es supercr?ticas." PROGRAMA DE P?S-GRADUA??O EM ENGENHARIA QU?MICA, 2017. https://repositorio.ufrn.br/jspui/handle/123456789/24506.
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Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES)
No contexto energ?tico mundial, o biodiesel tem despontado como uma importante fonte de energia renov?vel, sobretudo devido ? facilidade de produ??o do mesmo e ? variedade de mat?ria-prima dispon?vel mundialmente. Especificamente no Brasil, a ind?stria de biodiesel tem apresentado importante crescimento de produ??o, tendo em vista as leis federais que obrigam a mistura do B100 (biodiesel) ao diesel f?ssil. Diante da import?ncia desta ind?stria para o Brasil, este trabalho buscou avaliar o potencial do ?leo de sementes de algod?o para a produ??o de biodiesel a partir de tr?s t?cnicas: transesterifica??o, utilizando etanol, interesterifica??o, usando acetato de metila, e interesterifica??o, com acetato de metila e adi??o de solu??o aquosa de ?cido ac?tico. As rea??es ocorreram em condi??es supercr?ticas, em reator tubular de fluxo cont?nuo com volume de 15 mL. O rendimento m?ximo obtido pela transesterifica??o foi de 75,05%, na press?o de 150 e 200 bar, 375 ?C, raz?o molar ?leo/etanol 1:40, e tempos espaciais 40 min (150 bar) e 30 min (200 bar). J? na rota utilizando acetato de metila, o maior rendimento foi de 99,51% (?steres met?licos de ?cidos graxos + triacetina), obtido em 35 min, raz?o m?ssica ?leo/acetato de metila 1:3, press?o 200 bar e 350 ?C, utilizando 20%, em massa, de solu??o aquosa de ?cido ac?tico com concentra??o de 26%. Foram observados elevados valores de decomposi??o do biodiesel, em ambas as rotas, devido ?s altas concentra??es de triglicer?deos poliinsaturados no ?leo e ?s severas condi??es do processo.
In the global energy context, biodiesel has emerged as an important source of renewable energy, mainly due to its ease of production and the variety of raw material available worldwide. Specifically in Brazil, the biodiesel industry has shown significant production growth, due to the federal laws that require the mixing of B100 (biodiesel) with fossil diesel. Considering the importance of this industry to Brazil, this work sought to evaluate the potential of cotton seed oil for the production of biodiesel from three techniques: transesterification using ethanol, interesterification using methyl acetate and interesterification with methyl acetate and addition of aqueous acetic acid solution. The reactions occurred under supercritical conditions in a continuous flow tubular reactor with a volume of 15 mL. The maximum yield obtained by transesterification was 75.05%, at 150 and 200 bar pressure, 375 ?C, 1:40 oil/ethanol molar ratio, and spatial times 40 min (150 bar) and 30 min (200 bar). In the other method, using methyl acetate, the highest yield was 99.51% (methyl esters of fatty acids+ triacetin) obtained in 35 min, oil/methyl acetate ratio 1:3, pressure 200 bar and 350 ?C, using 20%, by mass, of aqueous acetic acid solution with a concentration of 26%. High values of biodiesel decomposition were observed in both routes due to the high concentrations of polyunsaturated triglycerides in the oil and the severe process conditions.
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Xavier, Vanessa Barbieri. "An?lise cromatogr?fica/olfatom?trica do potencial arom?tico de extratos naturais livres e incorporados a materiais pela impregna??o supercr?tica." Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2016. http://tede2.pucrs.br/tede2/handle/tede/6620.
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Submitted by Setor de Tratamento da Informa??o - BC/PUCRS (tede2@pucrs.br) on 2016-04-22T12:51:06Z
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Funda??o de Amparo ? Pesquisa do Estado do Rio Grande do Sul - FAPERGS
The determination of the contribution of certain constituents to the global odor of a product has been the subject of interest to researchers. It is known that only a small part of the large number of volatile compounds present in a fragrant matrix contributes to the perception of its odor. In addition, these molecules do not contribute equally to the global odor profile of a sample, so a large relative concentration of a compound; do not necessarily correspond to a high intensity odor. Gas chromatography/olfactometry (GC/O) is analytic technic appropriate for studying such issues, since it enables the assessment of odor of each component of complex mixture through specific correlation with the compounds of interest. This is possible because the volatile components of the substances have perceived simultaneously by two detectors, one being the human olfactory system and the other the chromatography detector. The objective of this study is the project, development, implementation and validation of a hybrid equipment (GC/O) to olfatometric analysis and the use of it as tooling for analysis of natural extracts incorporated in different materials. The initial result of the work consisted of the olfactometer own, tested and validated for use in studies associated with this thesis. With the olfactometer, essential oils were analyzed of native species in order to assess the aromatic potential of these extracts and volatile compounds of honey as a way to develop and validate an alternative technique to identification source. With the results referent to the equipment and raw materials, there was made studies on the controlled release of volatile compounds impregnated in textiles by supercritical impregnation, using the gas chromatography/olfactometry as an analytical method.
A determina??o da contribui??o de determinados constituintes para o aroma global de um produto tem sido alvo de interesse de pesquisadores. Sabe-se que apenas uma pequena parte do grande n?mero de compostos vol?teis presentes em uma matriz perfumada contribui para percep??o do seu aroma. Al?m disso, estes compostos n?o contribuem igualmente para o perfil do aroma global da matriz, portanto, uma grande concentra??o relativa de um determinado composto, n?o necessariamente correspondem a intensidades altas de aroma. A cromatografia gasosa/olfatometria (GC/O) ? a t?cnica anal?tica indicada para estudar tais quest?es, pois permite a avalia??o do aroma de cada componente de uma mistura complexa, atrav?s da correla??o espec?fica com os compostos de interesse; isso ? poss?vel porque os componentes vol?teis das subst?ncias s?o percebidos simultaneamente por dois detectores, sendo um deles o sistema olfativo humano e o outro um detector cromatogr?fico. O objetivo deste estudo foi o desenvolvimento, implanta??o e valida??o de um equipamento h?brido (GC/O) para an?lises olfatom?tricas e emprego do mesmo como ferramental de an?lise de extratos naturais incorporados em materiais. Inicialmente, o olfat?metro foi constru?do, testado e validado, para uso em diferentes matrizes. Com o olfat?metro, foram analisados ?leos essenciais de esp?cies nativas como forma de avaliar o potencial arom?tico destes extratos e compostos vol?teis de m?is como forma de propor e validar uma t?cnica alternativa de identifica??o de origem destes produtos. A partir dos resultados referentes ao equipamento e ?s mat?rias primas, realizou-se estudos sobre a libera??o controlada de compostos vol?teis impregnados em tecidos pela impregna??o supercr?tica, tendo como m?todo de an?lise a cromatografia gasosa/olfatometria.
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Almeida, Patr?cia Carvalho. "Extra??o de cromenos a partir de Ageratum conyzoides L. : identifica??o qu?mica e modelagem matem?tica do processo." Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2015. http://tede2.pucrs.br/tede2/handle/tede/6545.
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DIS_PATRICIA_CARVALHO_ALMEIDA_COMPLETO.pdf: 1695882 bytes, checksum: 485e636dfb13c1dacc99571a2309aa50 (MD5)Made available in DSpace on 2016-03-28T11:33:08Z (GMT). No. of bitstreams: 1 DIS_PATRICIA_CARVALHO_ALMEIDA_COMPLETO.pdf: 1695882 bytes, checksum: 485e636dfb13c1dacc99571a2309aa50 (MD5) Previous issue date: 2015-11-30
Extracts obtained from natural products have attracted the interest of pharmacological sector due to the chemical and biological properties. Therefore, in this work were studied the chromenes (precocene I and II) extraction processes, steam distillation and supercritical fluid extraction (SFE), from Ageratum conyzoides L. Essential oil was extracted by saturated steam at 1.0, 1.5, and 2.0 bar and the supercritical fluid extractions were performed at 40?C and 90, 120, 150, and 200 bar to obtain non-volatile extracts. The essential oils were analyzed by gas chromatography/mass spectroscopy while the non-volatile extracts composition was determined by high-performance liquid chromatography. The essential oil presented two major compounds, precocene I (28.24 ? 2.64%) and precocene II (28.55 ? 2.08%). At 90 bar, the SFE resulted in higher yield and selectivity for precocene I and II, which represent 65.06% of extract. It was observed that the yield of chromenes varies according to pressure of SFE, however this behavior was not observed in the extracts obtained by steam distillation. A mathematical model was also used to simulate the processes and a good correlation was attained with the experimental data.
Extratos obtidos a partir de produtos naturais t?m atra?do o interesse do setor farmacol?gico devido ?s propriedades qu?micas e biol?gicas. Portanto, neste trabalho foram estudados os processos de extra??o de cromenos (precoceno I e II), destila??o a vapor e extra??o com fluido supercr?tico (SFE), a partir de Ageratum conyzoides L. O ?leo essencial foi extra?do por vapor saturado a 1,0, 1,5, e 2,0 bar e as extra??es com fluido supercr?tico foram realizadas a 40?C e 90, 120, 150, e 200 bar para obter extratos n?o vol?teis. Os ?leos essenciais foram analisados por cromatografia gasosa e espectroscopia de massa, enquanto que a composi??o dos n?o-vol?teis extratos foi determinada por cromatografia l?quida de alta efici?ncia. O ?leo essencial apresentou dois compostos principais, precoceno I (28,24 ? 2,64%) e precoceno II (28,55 ? 2,08%). A 90 bar, a SFE resultou em maior rendimento e seletividade para os precoceno I e II, que representaram 65,06% do extrato. Observou-se que o rendimento de cromenos varia de acordo com a press?o da SFE, no entanto, isto n?o foi observado nos extratos obtidos por meio de destila??o a vapor. Um modelo matem?tico tamb?m foi usado para simular os processos e uma boa correla??o foi obtida com os dados experimentais.
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Rebou?as, ?rica Guedes. "Influ?ncia do leito de inertes em reator tubular para produ??o de biodiesel a partir de ?leo de soja e etanol supercr?tico." PROGRAMA DE P?S-GRADUA??O EM ENGENHARIA QU?MICA, 2016. https://repositorio.ufrn.br/jspui/handle/123456789/22576.
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A partir das limita??es nas fontes de energia, principalmente aos derivados de petr?leo, surge o biodiesel que ? produzido por rotas tradicionais e consolidadas, como a transesterifica??o, empregando aquecimento convencional e cat?lise homog?nea. Na busca por novas tecnologias de produ??o de biodiesel, os processos utilizando ?lcool em condi??es supercr?ticas t?m sido amplamente investigados. E a import?ncia de uma opera??o cont?nua tem levado a alguns estudos de produ??o de biodiesel em meio supercr?tico utilizando reatores tubulares. O presente trabalho tem o objetivo de investigar o emprego de leito de inertes (vidro) em um reator tubular para produ??o de biodiesel a partir de ?leo de soja com etanol pressurizado. A partir de um planejamento experimental, foram analisados os efeitos da temperatura (300, 350 e 400?C), da vaz?o volum?trica de alimenta??o dos reagentes (0,5 e 1 mL/min) e da porosidade do leito (0,42, 0,38 e 0,32) nas condi??es de 15 MPa e raz?o molar ?leo:etanol 1:40 sobre o teor em ?steres. Al?m disso, foi analisado o efeito da raz?o molar ?leo:etanol, e para isso foram conduzidas corridas experimentais a 350?C, 15 MPa e porosidade de 0,38 nas vaz?es de 0,3; 0,5; e 1 mL/min, em diferentes raz?es molares (1:10 ? 1:70). Em geral, os resultados indicaram um efeito positivo da temperatura sobre o teor em ?steres, devido a maior solubilidade do ?leo no ?lcool, nestas condi??es. Outro resultado interessante, foi o efeito combinado da vaz?o e da porosidade sobre tempo de resid?ncia, maximizando a transfer?ncia de massa e a miscibilidade entre as fases, possibilitando o avan?o da rea??o em baixos tempos. O melhor resultado em teor de ?steres (98,99%) foi alcan?ado ap?s 5,44 min de rea??o, nas condi??es de 400?C, 15MPa, raz?o molar ?leo de soja:etanol 1:40, vaz?o de alimenta??o de 0,5 mL/min, e porosidade de 0,32.
From the limitations of energy sources, mostly oil derivatives, biodiesel, traditionally produced comes with well-established routes of production such as the transesterification, using conventional heating and homogeneous catalysis. In the search for new technologies in the production of biodiesel, the methods that use alcohol in supercritical conditions have been widely investigated. The importance of continuous operation has taken to some studies of biodiesel production in supercritical method using tubular reactors. The following project has aims to investigate the use of inert (glass) in a tubular bed reactor for the production of biodiesel from soybean oil with pressurized. The effects of the temperature (300, 350 and 400?C), the volumetric flow rate of the reagents (0,5 and 1 mL/min), bed porosity (0.42, 0.38 and 0.32) under the conditions of 15 MPa and molar ratio oil: ethanol 1:40 on the esters conversion of the reaction were analyzed. In addition, the effect of the oil: ethanol molar ratio was analyzed, and for this, experimental runs were conducted at 350?C, 15 MPa and porosity of 0.38 at flow rates of 0.3; 0.5; and 1 mL/min, in different molar ratios (1:10 - 1:70). In general, the results indicated a positive effect of temperature on the ester content, due to the higher solubility of the oil in the alcohol under these conditions. Another interesting result was the combined effect of flow rate and porosity on residence time, maximizing the mass transfer and the miscibility between the phases, allowing the advance of the reaction at low times. The best result (98.99%) were achieved after 8 min of reaction under the conditions of 400?C, 15 MPa, molar ratio soybean oil: ethanol 1:40, flow rate of 0.5 mL/min, and porosity of 0.32.
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Rosa, Ant?nio Alberto Andrade da. "Uso da extra??o supercritica na obten??o de produtos com valor agregado a partir de res?duos s?lidos da ind?stria vin?cola." Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2014. http://tede2.pucrs.br/tede2/handle/tede/3272.
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Previous issue date: 2014-08-29The study of the extraction of substances with value-added from waste of the wine industry is proposed due to the annual generating thousands of tons of seeds and cables, called bagasse, coming wineries of the productive region of the northeastern state of Rio Grande do Sul processes. At this moment, this material is perceived as process residue and used only as raw material for composting. Studies show that grape seed (Vitis vinifera L.) may contain compounds with high antioxidant power. The antioxidant power of the extract gives it desirable characteristics for applications in human health, and can be used as food, medicine and cosmetic formulation. In this work the grape waste were collected 20 to 30 days post-pressing and separated into two fractions: one composed only by grape seeds and the other by the remaining material (pulp, peel and bits of curl). Both fractions were subjected to supercritical extraction process using carbon + water and carbon dioxide as solvents. Process operating conditions were: temperature 35 ? C and pressures of 100, 120, 150, 200 and 250 bar, yielding data for construction of yield versus time curves. Then the mathematical modeling was applied to represent the extraction process, this study grounded on the knowledge of mass transfer. Regarding the extracts, they were assessed using DPPH (2,2-diphenyl-1-picryl-hydrazyl), aimed to determining the antioxidant power. As a result, it was observed that the extracts of the pulp, and pieces of bark curl had a high antioxidant power and the mathematical model employed showed high adherence to the experimental data represented by the extraction curve.
O estudo da extra??o de subst?ncias com valor agregado dos res?duos da ind?stria vin?cola ? proposto devido ? gera??o anual de milhares de toneladas de sementes e cabos, chamados de baga?o, oriundos dos processos produtivos das vin?colas da regi?o nordeste do estado do Rio Grande do Sul. At? o presente momento este material ? percebido como res?duo de processo e utilizado somente como mat?ria-prima para compostagem. Estudos demonstram que as sementes de uva (Vitis vin?fera L.) podem conter compostos com elevado poder antioxidante. O poder antioxidante do extrato confere a ele caracter?sticas desej?veis para aplica??es em benef?cio da sa?de humana, podendo ser utilizado como alimento, medica??o e na formula??o de cosm?ticos. Neste trabalho os res?duos de uva foram coletados 20 a 30 dias p?s-prensagem e separado em duas fra??es: uma constitu?da s? por sementes de uva e a outra pelo material restante (polpa, casca e peda?os de cacho). As duas fra??es foram submetidas ao processo de extra??o supercr?tica, utilizando di?xido de carbono e di?xido de carbono + ?gua como solventes. As condi??es operacionais de processo foram as seguintes: temperatura de 35?C e press?es de 100, 120, 150 200 e 250 bar, gerando curvas de rendimento versus tempo. Aplicou-se ent?o a modelagem matem?tica ao processo de extra??o, estudo este embasado nos conhecimentos de transfer?ncia de massa. Em rela??o aos extratos, os mesmos foram analisados pela metodologia DPPH (2,2-difenil-1-picril-hidrazil), visando ? determina??o do poder antioxidante. Como resultado, observou-se que os extratos da polpa, casca e peda?os de cacho tiveram um elevado poder antioxidante e o modelo matem?tico empregado apresentou alta ader?ncia aos dados experimentais representados pela curva de extra??o.
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Santo, Alexandre Timm do Espirito. "Estudo sobre processos de extra??o e purifica??o de cafe?na da erva-mate." Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2016. http://tede2.pucrs.br/tede2/handle/tede/6665.
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Submitted by Setor de Tratamento da Informa??o - BC/PUCRS (tede2@pucrs.br) on 2016-05-13T12:15:28Z
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DIS_ALEXANDRE_TIMM_DO_ESPIRITO_SANTO_COMPLETO.pdf: 2313830 bytes, checksum: 334f0f0935a05344e80b2af615a075a8 (MD5)Made available in DSpace on 2016-05-13T12:15:28Z (GMT). No. of bitstreams: 1 DIS_ALEXANDRE_TIMM_DO_ESPIRITO_SANTO_COMPLETO.pdf: 2313830 bytes, checksum: 334f0f0935a05344e80b2af615a075a8 (MD5) Previous issue date: 2016-03-03
Funda??o de Amparo ? Pesquisa do Estado do Rio Grande do Sul - FAPERGS
The caffeine market extracted from natural products is rising due to the increasing consumption of product that use caffeine as a raw material, therefore new ways to obtain caffeine are being studied. Drugs, cosmetic and energy drinks industries are example of industries that are growing and use caffeine in their process. Mate has caffeine up to 2% in mass in the leaves and it is considered as an alternative way to obtain caffeine. However, it is necessary to develop a technology able to extract and after that purify caffeine. Thus, this work aims to study four different extraction process: supercritical fluid extraction (SFE), modified electric field (MEF), high pressure processing (HPP) and infusion; and four purification methodologies: supercritical antisolvent (SAS), sublimation and recrystallization, fractionation by column chromatography and liquid-liquid extraction. To analysis the caffeine in all process HPLC were used. The results showed that all four technologies were able to extract caffeine from mate leaves, however the infusion extraction showed to be the most effective technique, extracting 1,78% mass of caffeine per mass of mate. SAS and fractionation by column chromatography showed the best result in terms of purity: 95.3% and 99.0%, respectively.
O mercado de cafe?na extra?da de produtos naturais vem apresentando crescimento devido ao aumento no consumo de produtos que utilizam esta mat?ria-prima como bebidas energ?ticas, f?rmacos e produtos cosm?ticos, logo novas formas de se obter o composto v?m sendo estudadas. A erva-mate, por possuir at? 2% em massa de cafe?na nas suas folhas, ? considerada uma fonte alternativa para obten??o de cafe?na, contudo ? necess?rio desenvolver uma tecnologia capaz de produzir cafe?na purificada. Portanto, este trabalho visa estudar quatro processos para promover a extra??o: extra??o por fluido supercr?tico (EFS), campo el?trico moderado (CEM), processamento por alta press?o (PAP) e infus?o; e quatro m?todos de purifica??o: antissolvente supercr?tico (SAS), sublima??o e recristaliza??o, fracionamento por cromatografia em coluna e extra??o l?quidol?quido. O procedimento anal?tico utilizado para quantificar a cafe?na resultante dos processos supracitados ? a cromatografia l?quida de alta efici?ncia. Os resultados demonstraram que todas as t?cnicas extrativas foram capazes de remover cafe?na das folhas de erva-mate, por?m a extra??o aquosa ? press?o atmosf?rica demonstrou-se mais efetiva, removendo at? 1,78% em massa de cafe?na por massa de erva-mate. J? o processo por SAS e o fracionamento por cromatografia em coluna foram os que apresentaram os melhores resultados em rela??o ? purifica??o, visto que prduziram cafe?na com 95,3% e 99,0% de pureza, respectivamnte.
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Rodrigues, Tania Regina Schmitz de Azevedo. "Corros?o do a?o API5L X65 por CO2 : propriedades dos filmes de produtos de corros?o em press?es subcr?ticas e supercr?ticas." Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2016. http://tede2.pucrs.br/tede2/handle/tede/7060.
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Submitted by Setor de Tratamento da Informa??o - BC/PUCRS (tede2@pucrs.br) on 2016-11-29T15:14:23Z
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Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES
Funda??o de Amparo ? Pesquisa do Estado do Rio Grande do Sul - FAPERGS
This study investigates the influence of pressure on the formation of corrosion product scales on API 5L X65 steel used in the oil and gas industry. Experiments were performed in humid CO2 and water saturated with CO2 environments at 50?C for periods of 168 and 360 hours in 2 MPa and 5 MPa subcritical conditions and 10 MPa, 15 MPa and 20 MPa supercritical conditions. The thermodynamic model of Duan was used to obtain information about CO2 solubility in water, the water concentration present in the humid CO2 and the pH for the experimental conditions used in this work. Corrosion rates were determined by weight loss tests, and the scales were characterized by scanning electron microscopy, electrochemical measurements and X-ray diffraction. The results showed that for the 168 hours exposure time, the size of iron carbonate crystals formed in CO2 saturated water was bigger in relation to the ones formed in humid CO2 environments, with the exception of the experiment performed at 20 MPa. The scales formed in 168 hours and 360 hours exposure time, in both environments and pressures, showed typical morphology of iron carbonate. It was also observed that the films tend to be more compact with increased immersion time, but not necessarily more protective. Corrosion rates were classified as severe according to NACERP- 07-75 for both subcritical to supercritical pressures in CO2 saturated water environment and for both exposure times. In the case of 168 hours of exposure and CO2 saturated water environment, the highest corrosion rate occurred at 15 MPa. Already for 360 hours exposure times, performed at supercritical pressures, the corrosion rates increased with increasing pressure and the higher corrosion rate values were observed in water saturated with CO2. Electrochemical impedance tests showed no significant differences in resistance to polarization in subcritical pressures to 168 hours for both environments. As for supercritical pressures, higher polarization resistance was 15 MPa for also both environments. As for supercritical pressures, higher polarization resistance was 15 MPa in CO2 environment. Potentiodynamic polarization tests indicated that at 168 hours of immersion, there was a reduction in the rate of dissolution of the films formed at 10 MPa and 20 MPa in both environments. For the 360 hours of immersion, the corrosion potential was most active at 5 MPa for water saturated with CO2, with no significant differences of humid CO2 environment.
Neste estudo avaliou-se a influ?ncia da press?o na forma??o dos filmes de produto de corros?o no a?o API5L X65 utilizado na ind?stria de petr?leo e g?s. A corros?o foi promovida em ambientes de CO2 ?mido e ?gua saturada com CO2 a 50?C, durante 168 horas e 360 horas, em press?es subcr?ticas de 2 MPa e 5 MPa e supercr?ticas de 10 MPa, 15 MPa e 20 MPa. Utilizou-se o modelo termodin?mico de Duan a fim de obter informa??es sobre solubilidade do CO2 em ?gua, a concentra??o de ?gua presente no CO2 ?mido e o pH para as condi??es experimentais utilizadas neste trabalho. As taxas de corros?o foram determinadas por ensaios de perda de massa, os filmes de produtos de corros?o foram caracterizados por microscopia eletr?nica de varredura, por medidas eletroqu?micas de imped?ncia e de polariza??o potenciodin?mica e difra??o de raios X. Os resultados indicaram que, para 168 horas, os cristais de carbonato de ferro foram maiores para o meio de ?gua saturada com CO2 que em meio de CO2 ?mido, com exce??o em 20 MPa. Os filmes de produtos de corros?o formados durante 168 horas e 360 horas, em ambos os meios e press?es, apresentaram morfologia t?pica de carbonato de ferro. Os filmes tendem a ser mais densos com o aumento do tempo de imers?o, por?m n?o necessariamente mais protetores. As taxas de corros?o foram classificadas como severas, segundo a NACE-RP-07-75 tanto para as press?es subcr?ticas quanto para supercr?ticas no meio de ?gua saturada com CO2, em ambos os tempos de exposi??o. Em 168 horas a maior taxa de corros?o ocorreu em 15 MPa em ?gua saturada com CO2. Para 360 horas, em press?es supercr?ticas, a taxa de corros?o aumentou com o aumento da press?o e as taxas de corros?o mais altas foram observadas para o meio de ?gua saturada com CO2. Os ensaios eletroqu?micos de imped?ncia n?o apresentaram diferen?as significativas ? resist?ncia ? polariza??o em press?es subcr?ticas, para 168 horas, para ambos os meios. Em 360 horas, em press?es subcr?ticas, a maior resist?ncia ? polariza??o foi em 5 MPa tamb?m para os dois meios. J? para press?es supercr?ticas, a maior resist?ncia ? polariza??o foi em 15 MPa no meio de CO2. Os ensaios de polariza??o potenciodin?mica indicaram que em 168 horas houve redu??o na velocidade de dissolu??o dos filmes formados em 10 MPa e 20 MPa em ambos os meios. Para 360 horas, o potencial de corros?o foi mais ativo em 5 MPa para ?gua saturada com CO2, n?o havendo diferen?as significativas para o meio de CO2 ?mido.
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Chide, Baptiste. "Le premier microphone sur Mars : contribution à la spectroscopie de plasma induit par laser et à la science atmosphérique." Thesis, Toulouse, ISAE, 2020. http://www.theses.fr/2020ESAE0041.
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Le 18 février 2021, l'astromobile de la NASA Perseverance se posera dans le cratère Jezero à la recherche de traces de vie passée. A son bord l'expérience franco-américaine SuperCam ne contient pas moins de quatre techniques spectroscopiques, une caméra haute résolution et un microphone. Ce microphone sera le premier à enregistrer des ondes acoustiques audibles à la surface de Mars entre 100 Hz et10 kHz. Il ouvrira un nouveau champ d'investigation qui fait l'objet de cette thèse. Les objectifs scientifiques de cette thèse s'organisent autour des sons qui seront audibles par ce microphone : les phénomènes atmosphériques dans l'environnement proche du véhicule et les bruits artificiels générés par SuperCam lui-même. Parmi ces derniers, la technique de la spectroscopie de plasma induit par laser (LIBS) ablate les roches et les sols martiens avec un laser impulsionnel, ce qui produit un signal acoustique lors de la détente de ce plasma. Ce manuscrit propose une étude amont qui vise à caractériser le support du microphone à la LIBS et sa contribution à la science atmosphérique. Ces deux thèmes sont explorés expérimentalement en reproduisant en laboratoire les conditions d'écoute que le microphone rencontrera sur Mars.Premièrement, un banc de mesure LIBS sous atmosphère martienne est utilisé pour comparer le signal acoustique issu de l'ablation de différents minéraux. Une étude métrologique a déterminé la sensibilité de l'énergie acoustique par rapport aux paramètres expérimentaux de la LIBS : elle est proportionnelle à la pression atmosphérique et à l'éclairement déposé sur la cible. Ces relations permettront de normaliser le signal acoustique entre toutes les cibles échantillonnées par la LIBS sur Mars. De plus il est remarqué que la décroissance de l'énergie acoustique au cours d'une séquence de tirs est linéairement reliée au volume de la cavité d'ablation et que le taux de décroissance est corrélé à la dureté de la roche. Volume d'ablation et dureté seront deux informations utilisées pour caractériser les cibles de SuperCam et en particulier étudier celles présentant des vernis d'altération en surface.D'autre part, une campagne de tests dans une soufflerie martienne est effectuée pour corréler les propriétés d'un écoulement de vent avec le signal acoustique induit par ce dernier sur le microphone. Il est démontré que le microphone peut déterminer la vitesse de l'écoulement en étudiant le contenu basse fréquence du spectre, mais aussi sa direction en regardant le contenu haute fréquence. Ces résultats nécessiteront une calibration in situ sur Mars avec la station météo de Perseverance, MEDA. Il est également montré que la synchronisation du microphone avec le laser permet une mesure originale de la vitesse du son et donc de la température atmosphérique proche de la surface.Enfin, cette validation des objectifs scientifiques du microphone s'accompagne d'un soutien au développement instrumental du microphone, avec la validation de ses performances, la définition des modes d'observation et la préparation des opérations de SuperCam à la surface de MarsIn February 2021 the Mars 2020 Perseverance rover will land in Jezero to search for traces of past life.Part of the Perseverance payload, the SuperCam instrument suite includes four spectroscopy techniques,a high resolution imager and a microphone. This microphone will be the first microphone to record audible acoustic waves on the surface on Mars between 100 Hz to 10 kHz. It will open a new field of investigation which is the subject of this thesis. The scientific objectives of this thesis are organized around the sounds that will be recorded by this microphone : atmospheric phenomena in the close vicinity of the rover and artificial noises generated by SuperCam itself. Among the latest, the laser-induced breakdown spectroscopy technique (LIBS) ablates Martian rocks and soils with a pulsed laser. It creates an acoustic signal due tothe expansion of this plasma. These two topics are experimentally explored thanks to the development of laboratory test benches that simulate the conditions likely to be encountered by the microphone on Mars.On the one hand a LIBS setup under Mars atmosphere is used to compare acoustic signal from several minerals. A metrological study of the sensitivity of the acoustic signal with respect to LIBS experimental parameters is conducted : the acoustic energy is proportional to the CO2 background pressure and to the irradiance deposited on the sample. These two relationships will help to normalize the acoustic signal from multiple LIBS targets on Mars. Moreover, it is noticed that the decrease of the acoustic energy along a LIBS burst is linearly linked to the ablated volume. The decrease rate is correlated to the rock hardness.It provides new information relative to the ablation process that is independent from the LIBS emission spectrum. It could be used to better characterize geologic targets and rock, in particular the ones with asurface coating or a weathering rind.On the other hand, a test campaign in a Martian wind tunnel is dedicated to link wind properties withwind-induced signal recorded by the microphone. It is demonstrated that the microphone can determinethe flow velocity by studying the low frequency range of the acoustic spectrum whereas the wind directioncan be retrieved by looking at the high frequency range. An in situ cross-calibration with the weather station on board Perseverance, MEDA, will be required to validate these results. It is also shown that the synchronization of the microphone with the LIBS laser can be used to measure the speed of sound and therefore to estimate the atmospheric temperature close to the surface of Mars.This work also describes some progresses in the microphone development including the performances' validation, the implementation of operating modes and the preparation of SuperCam operations at the surface of Mars
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Grandini, Camila Pereira. "Obten??o de extratos vol?teis e n?o vol?teis de Pluchea sagittalis (Lam.) Cabrera (Quitoco) : processos e an?lises." Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2017. http://tede2.pucrs.br/tede2/handle/tede/7473.
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Conselho Nacional de Pesquisa e Desenvolvimento Cient?fico e Tecnol?gico - CNPq
The growing concern of industries in finding natural inputs in place of synthetic ones in the production of bioactive products in the pharmaceutical, food and cosmetic areas motivated this research to the study of the biological activities of the volatile and non-volatile extracts of Pluchea sagittalis. This plant known as quitoco of spontaneous growth in nature is found in tropical regions having its origin in the South American continent. The goal of this study was to obtain volatile and nonvolatile extracts from the aerial parts of the quitoco and to evaluate the chemical composition and the biological activities of the extracts obtained. In order to obtain extracts from leaf and stem samples of P. sagittalis, without flowers and flower samples, two processes were used: Extraction by steam drag, to obtain volatile extracts, and supercritical extraction, to obtain non-volatile extracts. The chemical composition of the extracts obtained by steam drag was analyzed by gas chromatography coupled with mass spectrometer. The antimicrobial activity of leaf and stem essential oil was tested with the bacteria Staphylococcus aureus and Escherichia coli and also with the fungus Candida albicans, both tests were performed using the indirect bioautography technique where the oil showed growth inhibition for Staphylococcus aureus and for the fungus Candida albicans. Volatile extracts of leaves and stems and flowers obtained by steam extraction and supercritical fluid at 90 bar pressure were evaluated for their aromatic potential by means of sensorial (olfatometric) analysis, having as best evaluation the extract obtained by supercritical extraction of quitoco flowers.
A crescente preocupa??o de ind?strias em encontrarem insumos naturais em substitui??o aos sint?ticos na produ??o de produtos bioativos nas ?reas farmac?utica, aliment?cia e cosm?tica motivou esta pesquisa quanto ao estudo das atividades biol?gicas dos extratos vol?teis e n?o vol?teis da Pluchea sagittalis. Esta planta conhecida como quitoco, de crescimento espont?neo, ? encontrada em regi?es tropicais tendo sua origem no continente sul-americano. O objetivo deste estudo consistiu em obter extratos vol?teis e n?o vol?teis das partes a?reas do quitoco e avaliar a composi??o qu?mica e as atividades biol?gicas dos extratos obtidos. Para a obten??o dos extratos a partir de amostras das folhas e talos da P. sagittalis, sem as flores, e amostras de flores foram utilizados dois processos: extra??o por arraste a vapor, para a obten??o de extratos vol?teis, e extra??o supercr?tica, para a obten??o de extratos vol?teis e n?o vol?teis. A composi??o qu?mica dos extratos obtidos por arraste a vapor foi determinada atrav?s da an?lise por cromatografia gasosa acoplada com espectr?metro de massa. A atividade antimicrobiana do ?leo essencial das folhas e talos foi testada com as bact?rias Staphylococcus aureus e Escherichia coli e tamb?m com o fungo Candida albicans, ambos os testes foram realizados atrav?s da t?cnica bioautografia indireta, onde o ?leo essencial apresentou inibi??o do crescimento para Staphylococcus aureus e para o fungo Candida albicans. Os extratos vol?teis das folhas e talos e das flores, obtidos atrav?s da extra??o por arraste a vapor e com fluido supercr?tico a 90 bar de press?o, foram avaliados quanto ao seu potencial arom?tico por meio de an?lise sensorial (olfatom?trica), tendo o extrato vol?til das flores obtido por extra??o supercr?tica um grande potencial para o uso em perfumaria.
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Bocklisch, Thilo. "Optimierendes Energiemanagement von Brennstoffzelle-Direktspeicher-Hybridsystemen." Doctoral thesis, Universitätsbibliothek Chemnitz, 2010. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-201000287.
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Die Dissertation beschreibt ein neues optimierendes Energiemanagement-Verfahren für Brennstoffzelle-Direktspeicher-Hybridsysteme. Den Ausgangspunkt bildet die Analyse der Schwankungseigenschaften spezifischer Energiezeitreihen: des Photovoltaik-Energieangebots und des elektrischen Verbrauchs von Haushalten. Konzepte zur zeitgestaffelten Zerlegung, Modellierung und Prognose werden vorgestellt. Der zweite Teil der Dissertation beschäftigt sich mit den Grundlagen von Aufbau und Funktion eines Brennstoffzelle-Direktspeicher-Hybridsystems und präsentiert Ergebnisse experimenteller und theoretischer Untersuchungen einer PEM-Brennstoffzelle, einer Supercap-Einheit, einer Lithium-Ionen Batterie sowie eines speziell entwickelten DC/DC-Wandlers. Praxistaugliche Modelle zur Beschreibung des Klemmenverhaltens, des Ladezustands und der auftretenden Wandlungsverluste werden vorgestellt. Der dritte Teil der Dissertation präsentiert ein neues optimierendes Energiemanagement-Verfahren. Optimierungsziele sind die Minimierung des Wasserstoffverbrauchs bei gleichzeitiger Reduzierung der dynamischen Brennstoffzellen-Beanspruchung. Das Verfahren basiert auf den drei Steuerungsebenen: Primärregelung, Sekundärregelung und Systembetriebsführung. Schwerpunkt bildet die Sekundärregelung auf der Basis einer speziellen Struktur aus Laderegler und Lastfolgeregler sowie zwei Blöcken zur aktiven Begrenzung des Leistungsgradienten und des Arbeitsbereichs der Brennstoffzelle. Die Funktion und Leistungsfähigkeit des Energiemanagement-Verfahrens werden an einem Simulations- und an einem Experimentiersystem nachgewiesen. Anwendungsbeispiele werden gegebenThe dissertation presents a new optimizing energy management concept for fuel cell-direct storage-hybrid systems. Initially, the characteristics of specific energy time series are investigated on the basis of real measurement data. A new concept for the multi-scale analysis, modelling and prediction of fluctuating photovoltaic supply and electric load demand profiles is developed. The second part of the dissertation starts with a discussion of the benefits of and the basic coupling and control principles for fuel cell-direct storage-hybrid systems. The typical characteristics of a PEM-fuel cell, a metal hydride hydrogen storage, a lithium-ion battery and a supercap unit are presented. A new modular DC/DC-converter is described. Results from experimental and theoretical investigations of the individual components and the overall hybrid system are discussed. New practicable models for the voltage-current-curve, the state of charge behaviour and the conversion losses are presented. The third part of the dissertation explains the new energy management concept. The optimization of power flows is achieved by a control-oriented approach, employing a) the primary control of bus voltage and fuel cell current, b) the secondary control to limit fuel cell current gradient and operating range and to perform direct storage charge control, and c) the system control to optimally adjust secondary control parameters aiming for a reduction of dynamic fuel cell stress and hydrogen consumption. Results from simulations and experimental investigations demonstrate the benefits and high capabilities of the new optimizing energy management concept. Examples of stationary and portable applications conclude the dissertation
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Galv?o, Elis?ngela Lopes. "Extra??o supercr?tica do ?leo de linha?a: constru??o do extrator, estudo de par?metros de processo, avalia??o qu?mica e antioxidante do produto." Universidade Federal do Rio Grande do Norte, 2009. http://repositorio.ufrn.br:8080/jspui/handle/123456789/15887.
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Previous issue date: 2009-05-15Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico
The aim of the present study was to extract vegetable oil from brown linseed (Linum usitatissimum L.), determine fatty acid levels, the antioxidant capacity of the extracted oil and perform a rapid economic assessment of the SFE process in the manufacture of oil. The experiments were conducted in a test bench extractor capable of operating with carbon dioxide and co-solvents, obeying 23 factorial planning with central point in triplicate, and having process yield as response variable and pressure, temperature and percentage of cosolvent as independent variables. The yield (mass of extracted oil/mass of raw material used) ranged from 2.2% to 28.8%, with the best results obtained at 250 bar and 50?C, using 5% (v/v) ethanol co-solvent. The influence of the variables on extraction kinetics and on the composition of the linseed oil obtained was investigated. The extraction kinetic curves obtained were based on different mathematical models available in the literature. The Mart?nez et al. (2003) model and the Simple Single Plate (SSP) model discussed by Gaspar et al. (2003) represented the experimental data with the lowest mean square errors (MSE). A manufacturing cost of US$17.85/kgoil was estimated for the production of linseed oil using TECANALYSIS software and the Rosa and Meireles method (2005). To establish comparisons with SFE, conventional extraction tests were conducted with a Soxhlet device using petroleum ether. These tests obtained mean yields of 35.2% for an extraction time of 5h. All the oil samples were sterilized and characterized in terms of their composition in fatty acids (FA) using gas chromatography. The main fatty acids detected were: palmitic (C16:0), stearic (C18:0), oleic (C18:1), linoleic (C18:2n-6) and α-linolenic (C18:3n-3). The FA contents obtained with Soxhlet dif ered from those obtained with SFE, with higher percentages of saturated and monounsaturated FA with the Soxhlet technique using petroleum ether. With respect to α-linolenic content (main component of linseed oil) in the samples, SFE performed better than Soxhlet extraction, obtaining percentages between 51.18% and 52.71%, whereas with Soxhlet extraction it was 47.84%. The antioxidant activity of the oil was assessed in the β-carotene/linoleic acid system. The percentages of inhibition of the oxidative process reached 22.11% for the SFE oil, but only 6.09% for commercial oil (cold pressing), suggesting that the SFE technique better preserves the phenolic compounds present in the seed, which are likely responsible for the antioxidant nature of the oil. In vitro tests with the sample displaying the best antioxidant response were conducted in rat liver homogenate to investigate the inhibition of spontaneous lipid peroxidation or autooxidation of biological tissue. Linseed oil proved to be more efficient than fish oil (used as standard) in decreasing lipid peroxidation in the liver tissue of Wistar rats, yielding similar results to those obtained with the use of BHT (synthetic antioxidant). Inhibitory capacity may be explained by the presence of phenolic compounds with antioxidant activity in the linseed oil. The results obtained indicate the need for more detailed studies, given the importance of linseed oil as one of the greatest sources of ω3 among vegetable oils
O presente trabalho teve como objetivo geral extrair o ?leo vegetal da linha?a (Linum usitatissimum L.) da variedade marrom fazendo uso de di?xido de carbono em condi??es supercr?ticas e de solvente org?nico, avaliar os teores de ?cidos graxos e a capacidade antioxidante do ?leo extra?do e ainda realizar a avalia??o econ?mica r?pida do processo EFS de manufatura do ?leo. Os experimentos foram conduzidos em um extrator de bancada, capaz de operar com di?xido de carbono e co-solventes, obedecendo a um planejamento fatorial 2? com triplicata no ponto central, tendo como vari?vel resposta o rendimento do processo e como vari?veis independentes a press?o, a temperatura e o percentual de co-solvente. Os rendimentos (massa de ?leo extra?do/ massa de mat?ria-prima utilizada) variaram de 2,2 a 28,8%, tendo os melhores resultados sido obtidos a 250 bar e 50?C, com uso do co-solvente etanol a 5% (v/v). A influ?ncia das vari?veis sobre a cin?tica de extra??o e sobre a composi??o do ?leo de linha?a obtido tamb?m foi investigada. As curvas cin?ticas de extra??o obtidas foram modeladas por diferentes modelos matem?ticos dispon?veis na literatura. Os modelos de Mart?nez et al. (2003) e o Simple Single Plate (SSP) de Gaspar et al. (2003) representaram os dados experimentais com os menores erros quadr?ticos m?dios (MSE). O custo de manufatura de 17,85 US$/kg?leo foi estimado para produ??o do ?leo de linha?a utilizando o software TECANALYSIS e a metodologia de Rosa e Meireles (2005). Com o intuito de estabelecer compara??es com a EFS, foram realizados ensaios de extra??o por t?cnica convencional em aparato Soxhlet utilizando ?ter de petr?leo. Estes apresentaram rendimentos m?dios de 35,2 % para um tempo de extra??o de 5h. Todas as amostras de ?leo obtidas foram esterificadas e caracterizadas em termos de sua composi??o em ?cidos graxos (AGs) usando a cromatografia gasosa. Os principais ?cidos graxos detectados foram: palm?tico (C16:0), este?rico (C18:0), ol?ico (C18:1), linol?ico (C18:2n-6) e α-linol?nico (C18:3n-3). Os teores dos AGs obtidos com Soxhlet diferiram daqueles obtidos para a EFS, com percentuais de AGs saturados e monoinsaturados mais elevados para a t?cnica Soxhlet com ?ter de petr?leo. Com rela??o ao teor do ?cido α-linol?nico (componente majorit?rio do ?leo de linha?a) nas amostras, a EFS se mostrou mais vantajosa que a extra??o Soxhlet, apresentando percentuais de 51,18 a 52,71%, enquanto que na extra??o Soxhlet, este foi de 47,84%. A atividade antioxidante do ?leo foi avaliada no sistema de co-oxida??o b-caroteno/?cido linol?ico. Os percentuais de inibi??o do processo oxidativo chegaram a 22,11% para o ?leo da EFS, sendo de apenas 6,09% para o ?leo comercial extra?do a frio, o que sugere que a t?cnica EFS preserva melhor os compostos fen?licos presentes na semente, compostos estes, provavelmente respons?veis pelo car?ter antioxidante do ?leo. Testes in vitro com a amostra de melhor resposta antioxidante foram realizados em homogenato de f?gado de ratos, de forma a investigar a inibi??o da peroxida??o lip?dica espont?nea ou autoxida??o do tecido biol?gico. O ?leo de linha?a se mostrou mais eficiente que o ?leo de peixe (usado como padr?o) na diminui??o da peroxida??o lip?dica do tecido hep?tico dos ratos Wistar, apresentando resultados equivalentes aos obtidos com o uso do BHT (antioxidante sint?tico). A capacidade inibit?ria pode ser atribu?da ? presen?a de compostos fen?licos com atividade antioxidante presentes no ?leo de linha?a. Os resultados obtidos indicam a necessidade de estudos mais aprofundados tendo em vista a import?ncia do ?leo de linha?a como uma das maiores fontes de ω3 dentre os ?leos vegetais
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Carvalho, Ricardo Henrique Rocha de. "Extra??o supercr?tica de ?leo de Sesamum indicum L. e aplica??o como inibidor de corros?o em a?o AISI 1020 atrav?s de sistemas microemulsionados." PROGRAMA DE P?S-GRADUA??O EM ENGENHARIA QU?MICA, 2015. https://repositorio.ufrn.br/jspui/handle/123456789/22444.
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Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq)
O problema da corros?o tem preocupado diversos setores da ind?stria no mundo, trazendo uma s?rie de inconvenientes e preju?zos na reposi??o ou manuten??o de diversos equipamentos constitu?dos de ligas met?licas. Inibidores de corros?o formulados ? base de sistemas microemulsionados, t?m sido estudados buscando minimizar os transtornos causados por processos corrosivos. Diante dessa realidade, o presente trabalho prop?s a formula??o de sistemas microemulsionados utilizando ?leo de gergelim como fase org?nica. O ?leo de gergelim utilizado na formula??o das microemuls?es foi extra?do via CO2 supercr?tico, mediante utiliza??o de planejamento fatorial 23, buscando as melhores condi??es de temperatura, press?o e percentual de metanol (co-solvente) para melhorar o rendimento do processo. A extra??o supercr?tica concentra no extrato obtido uma s?rie de componentes polares conhecidos como lignanas, destacando-se a sesamina, sesamolina e o sesamol, conferindo ao ?leo uma excelente capacidade antioxidante. A efici?ncia do ?leo de gergelim (Sesamum indicum L.) como antioxidante e como inibidor de corros?o foi avaliada mediante an?lise dos sistemas ?-caroteno/?cido linol?ico e t?cnica eletroqu?mica de curvas de polariza??o de Tafel. Os sistemas microemulsionados foram caracterizados e em seguida aplicados como inibidores de corros?o em a?o carbono AISI 1020, muito comum na ind?stria do petr?leo. Dois sistemas microemulsionados foram formulados, O SME1 (composto por ?leo de gergelim, ?gua e Tween 80 como tensoativo) e o SME2 (composto por ?leo de gergelim, ?gua e uma mistura na raz?o de 1:1 de Ultrol L/90 e butanol, como tensoativo e cotensoativo respectivamente). Os sistemas SME1 e SME2 foram testados em concentra??es de 25, 50, 75, 100, 200 e 400 ppm em solu??es salina afim de determinarmos o percentual de inibi??o ? corros?o de cada sistema. No processo de extra??o supercr?tica, segundo an?lise estat?stica, o par?metro que mais influenciou no rendimento foi a press?o, alcan?ando o m?ximo de 34,23% a uma press?o de 250 bar, temperatura de 70?C e 10% de metanol como co-solvente. Foi poss?vel gerar um modelo matem?tico que se mostrou preditivo e significativo para um intervalo de confian?a de 95%. Quanto ? inibi??o da corros?o do a?o AISI 1020, o sistema SME2 na concentra??o de 400 ppm alcan?ou uma efici?ncia m?xima de 88,16% de inibi??o de passagem de corrente pelo eletrodo em estudo. Os resultados de efici?ncia de inibi??o da corros?o do SME2 foram ajustados ?s isotermas de Langmuir e Frumkin, visando entender melhor o processo de adsor??o dessas microemuls?es sobre as superf?cies met?licas. A isoterma que melhor se ajustou aos resultados experimentais, apresentando um R2 = 0,99 foi a de Langmuir, comprovando que o processo de adsor??o das micelas foi puramente f?sico, ligando-se ? superf?cie met?lica por for?as de Van Der Walls.
O problema da corros?o tem preocupado diversos setores da ind?stria no mundo, trazendo uma s?rie de inconvenientes e preju?zos na reposi??o ou manuten??o de diversos equipamentos constitu?dos de ligas met?licas. Inibidores de corros?o formulados ? base de sistemas microemulsionados, t?m sido estudados buscando minimizar os transtornos causados por processos corrosivos. Diante dessa realidade, o presente trabalho prop?s a formula??o de sistemas microemulsionados utilizando ?leo de gergelim como fase org?nica. O ?leo de gergelim utilizado na formula??o das microemuls?es foi extra?do via CO2 supercr?tico, mediante utiliza??o de planejamento fatorial 23, buscando as melhores condi??es de temperatura, press?o e percentual de metanol (co-solvente) para melhorar o rendimento do processo. A extra??o supercr?tica concentra no extrato obtido uma s?rie de componentes polares conhecidos como lignanas, destacando-se a sesamina, sesamolina e o sesamol, conferindo ao ?leo uma excelente capacidade antioxidante. A efici?ncia do ?leo de gergelim (Sesamum indicum L.) como antioxidante e como inibidor de corros?o foi avaliada mediante an?lise dos sistemas ?-caroteno/?cido linol?ico e t?cnica eletroqu?mica de curvas de polariza??o de Tafel. Os sistemas microemulsionados foram caracterizados e em seguida aplicados como inibidores de corros?o em a?o carbono AISI 1020, muito comum na ind?stria do petr?leo. Dois sistemas microemulsionados foram formulados, O SME1 (composto por ?leo de gergelim, ?gua e Tween 80 como tensoativo) e o SME2 (composto por ?leo de gergelim, ?gua e uma mistura na raz?o de 1:1 de Ultrol L/90 e butanol, como tensoativo e cotensoativo respectivamente). Os sistemas SME1 e SME2 foram testados em concentra??es de 25, 50, 75, 100, 200 e 400 ppm em solu??es salina afim de determinarmos o percentual de inibi??o ? corros?o de cada sistema. No processo de extra??o supercr?tica, segundo an?lise estat?stica, o par?metro que mais influenciou no rendimento foi a press?o, alcan?ando o m?ximo de 34,23% a uma press?o de 250 bar, temperatura de 70?C e 10% de metanol como co-solvente. Foi poss?vel gerar um modelo matem?tico que se mostrou preditivo e significativo para um intervalo de confian?a de 95%. Quanto ? inibi??o da corros?o do a?o AISI 1020, o sistema SME2 na concentra??o de 400 ppm alcan?ou uma efici?ncia m?xima de 88,16% de inibi??o de passagem de corrente pelo eletrodo em estudo. Os resultados de efici?ncia de inibi??o da corros?o do SME2 foram ajustados ?s isotermas de Langmuir e Frumkin, visando entender melhor o processo de adsor??o dessas microemuls?es sobre as superf?cies met?licas. A isoterma que melhor se ajustou aos resultados experimentais, apresentando um R2 = 0,99 foi a de Langmuir, comprovando que o processo de adsor??o das micelas foi puramente f?sico, ligando-se ? superf?cie met?lica por for?as de Van Der Walls.
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Silva, Graciane Fabiela da. "Investiga??o de atividades biol?gicas e potencial uso de extratos das flores de ac?cia mearnsii obtidos por arraste a vapor e extra??o com fluido supercr?tico." Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2018. http://tede2.pucrs.br/tede2/handle/tede/8154.
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Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES
Although the Acacia mearnsii tree is widely cultivated and used in the industry, its flowers are seldom researched. Considering the extensive availability of A. mearnsii flowers and the growing interest in natural products, this work aimed at the obtainment of extracts from these flowers and investigation of their composition and biochemistry properties. In this work, essential oil and aqueous extract by steam distillation and extracts were obtained with supercritical fluid. The essential oil was characterized by CG-MS and olfactometry. The main compounds identified in the essential oil were 8-heptadecene, heptadecane, nonadecane e kaurene. The main aroma detected by olfactometric analysis was roast nutty, as well as coffee, sweet, floral, vegetal and spicy. Antioxidant activity was determined and the aqueous extract showed an activity superior to rutin standard. LC-qTOF-MS identified 42 likely phenolic compounds, such as quercitrin, naringenin, myricetin, rutin, and robinetin. The extracts obtained by supercritical extraction and isolated fractions presented activity against S. aureus. The yield of the supercritical extraction was optimized using factorial planning and mass transfer parameters were obtained through mathematical models that represent the extraction curve. Thus, it was concluded that the flowers of A. mearnsii can be exploited by extractive processes used in this study to generate a plant by-product. The results indicate the aromatic and antioxidant potential of the essential oil and aqueous extract, respectively, obtained with 2.0 bar steam distillation, while the supercritical extract has antibacterial action.
A Acacia mearnsii, apesar de ser amplamente cultivada e utilizada industrialmente, n?o tem o potencial de suas flores explorado. Considerando a disponibilidade de flores da A. mearnsii e o crescente interesse por produtos naturais, esse trabalho consistiu na obten??o de extratos destas flores e na investiga??o de suas composi??es e a??es bioqu?micas. A pesquisa compreendeu a extra??o do ?leo essencial e a obten??o do extrato aquoso de flores da planta via destila??o por arraste a vapor, al?m da extra??o com fluido supercr?tico. O ?leo essencial foi analisado por GC-MS e apresentou, entre os 31 compostos identificados, 8-heptadeceno, heptadecano, nonadecano e caureno como compostos majorit?rios. Na an?lise olfatom?trica (GC-O), os principais aromas detectados no ?leo essencial foram caf?, doce, floral, vegetal e refrescante, com destaque para ?castanha/defumado?. O extrato aquoso das flores da A. mearnsii apresentou atividade antioxidante superior ? da rutina. Utilizando cromatografia de alta resolu??o (LC-qTOF/MS), foram verificados 42 prov?veis compostos fen?licos, entre eles, quercitrina, naringenina, miricetina, rutina, robinetina. Os extratos obtidos via extra??o supercr?tica e fra??es isoladas apresentaram atividade frente a S. aureus. O rendimento da extra??o supercr?tica foi otimizado utilizando planejamento fatorial e par?metros da transfer?ncia de massa foram obtidos atrav?s de modelos matem?ticos que representam a curva de extra??o. Assim, concluiu-se que as flores de A. mearnsii podem ser exploradas pelos processos extrativos empregados nesse estudo a fim de gerar um co-produto da cadeia produtiva da planta, uma vez que o ?leo essencial e o extrato aquoso, obtidos pela extra??o por arraste a vapor a 2,0 bar, possuem, respectivamente, potencial arom?tico e poder antioxidante, enquanto o extrato obtido com fluido supercr?tico apresenta a??o antibacteriana.
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Falc?o, Manuel Alves. "Estudo de extra??o de C. roseus e produ??o de nanopart?culas para libera??o de vimblastina." Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2016. http://tede2.pucrs.br/tede2/handle/tede/6953.
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Chemotherapy is highlighted for the treatment of many classes of tumors, especially by new drug delivery nanosystems. The drug delivery nanosystems are focused on greater selectivity for abnormal tissue, decrease adverse effects, dose reduction and decreased frequency applications. Due to the scale of these systems, the EPR effect favors the permeabilization in blood vessels and retention in tumor tissue particles. This thesis performed vinblastine extractions from C. roseus using water and ethanol as co-solvents for CO2 at 300 bar and at different temperatures, those experiments showed the viability of this extraction method, subsequent extractions were optimized using ethanol. The results are compared to traditional extraction methods such as solid-liquid extraction the results found was up to 92.41%. Concluding that vinblastine extraction using carbon dioxide and ethanol mixtures at high pressure is possible. The PLGA nanoparticles containing vinblastine showed again the reproducibility of the nanoemulsion method of ensuring the production of homogeneous nanoparticles with and without drug and cell viability experiments show that the three formulations of PLGA nanoparticles containing vinblastine potentiated drug activity at the lower doses, 1 and 5 ?g/mL, compared to free drug. The studies of glycopolymers synthesis presented the novel synthesis of an ATRP initiator based on PLGA without using PEG spacers. This initiator may, in future studies, be used for modifying PLGA. Successive attempts monomer polymerization saccharide via ATRP in water and DMSO leads to the conclusion that this approach is not the most suitable for the syntheses of glycopolymers graft from a PLGA initiator without the use of PEG spacers.
A quimioterapia ? op??o terap?utica para o tratamento de diversas classes de tumores, principalmente pelos novos nanosistemas de libera??o modificada de f?rmacos. Os nanosistemas de libera??o modificada t?m como foco a maior seletividade aos tecidos anormais, a diminui??o de efeitos adversos, redu??o da dose e diminui??o da frequ?ncia de aplica??es. Devido a escala destes sistemas, o efeito EPR favorece a permeabiliza??o nos vasos sangu?neos e a reten??o de part?culas no tecido tumoral. Nesta tese foram realizadas extra??es de vimblastina a partir de C. roseus utilizando ?gua e etanol como cossolventes de CO2 a 300 bar e a diferentes temperaturas mostraram a viabilidade do m?todo de extra??o, posteriormente, as extra??es foram otimizadas utilizando etanol. Quando os resultados encontrados s?o comparados a m?todos tradicionais de extra??o como a extra??o s?lido-l?quido o resultado encontrado foi de at? 92,41% superior. Concluindo, que a extra??o de vimblastina utilizando misturas de di?xido de carbono e etanol a altas press?es ? poss?vel. As nanopart?culas de PLGA contendo vimblastina demonstraram a reprodutibilidade do m?todo de nanoemuls?o garantindo a produ??o de nanopart?culas homog?neas, com e sem f?rmaco. Os experimentos de viabilidade celular mostraram que as tr?s formula??es de nanopart?culas de PLGA contendo vimblastina potencializaram a atividade do f?rmaco para as doses mais baixas, 1 e 5 ?g/mL, em rela??o ao f?rmaco livre. Os estudos realizados de s?ntese de glicopol?meros apresentaram a s?ntese in?dita de um iniciador de ATRP baseado em PLGA sem o uso de espa?adores de PEG. Este iniciador pode, em futuros estudos, ser utilizado para a modifica??o de PLGA. As sucessivas tentativas de polimeriza??o de mon?meros de sacar?deos via ATRP em ?gua e DMSO leva a conclus?o que esta metodologia n?o ? a mais adequada para s?nteses glicopol?meros conjugados a PLGA sem o uso de espa?adores de PEG.
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Brahim, Bessem. "Etude de la stabilité des interactions ioniques en phase gazeuse : application aux complexes biologiques." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2014. http://tel.archives-ouvertes.fr/tel-00978816.
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Les interactions non-covalentes (NCI pour Non-Covalent Interactions) stabilisant les complexes non-covalents biologiques (NCX pour Non-Covalent compleXes) régissent la majorité des processus cellulaires indispensables au développement et au bon fonctionnement de tout organisme vivant. Toutes les fonctions de l'ADN, tels que son conditionnement, sa réplication et la régulation de son expression, sont permises par la formation et la dissociation de NCI avec des protéines. La compréhension des bases de ces processus cellulaires de l'ADN au niveau moléculaire est un sujet d'actualité et d'une importance fondamentale. Des informations essentielles peuvent être obtenues par spectrométrie de masse (MS pour Mass Spectrometry) qui joue un rôle de plus en plus important dans ce domaine. Malgré la technologie avancée déjà mise en ¿uvre, le développement de nouveaux concepts d'ionisation et d'activation implémentent perpétuellement la MS. Les travaux de thèse exposés à travers ce manuscrit présente l'étude de la stabilité des NCI maintenant les NCX biologiques par la comparaison des voies de fragmentations observées en mode positif et en mode négatif mais aussi par l'application de certains concepts récents de la MS comme : (i) l'utilisation d'agents de " superchargement " et, (ii) le développement et l'utilisation d'une source V-EASI (pour Venturi Easy Ambiant Sonic-spray Ionization) permettant l'aspiration libre de la solution et la désorption/ionisation des analytes par la seule vélocité du gaz de nébulisation.
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Eliasson, Fadi, and Liv Lundmark. "Superkondensatorer istället för batterier som energireserv i lågvoltssystem." Thesis, Linköpings universitet, Elektroniska Kretsar och System, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-168433.
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Denna rapport undersöker om superkondensatorer kan ersätta en energireserv bestående av batterier i en befintlig produkt. Bakomliggande teori av superkondensatorn redovisas samt dess användning som energireserv i lågvoltssystem. En krets konstrueras och testas för att verifiera funktionen. Simuleringar utförs för att verifiera valen till kretsen. Matlab och LTSpice används för simuleringarna. Kretsen skapas i OrCad och Altium Designer. Teorin, simuleringarna och testerna pekar på att superkondensatorer kan ersätta batterierna samt att de ställda kraven går att uppfylla. Alla tester gav dock inte resultat och därför kunde inte alla krav verifieras. Framtida tester behövs för att kunna garantera att lösningen kan uppfylla livslängds- och temperaturkraven eller om det behövs bytas till superkondensatorer med större kapacitet.This report examines if supercapacitors could replace the existing batteries used in a product as a power source. The theory of supercapacitors and the use of these as a power source in low volt systems is presented. A circuit was created and tested to verify the function. Simulations were performed to verify the choices for the circuit. Matlab and LTSpice was used for the simulations. The circuit was created using OrCad and Altium Designer. The theory, simulations and tests all pointed towards that indeed supercapacitors can replace the existing batteries and the requirements can be met. Although not all tests resulted in results, therefore not all of the requirements could be verified. Future tests are needed to be able to guarantee that the solution can meet the lifetime and temperature requirements or if it will be necessary to replace the supercapacitors with ones that have higher capacity.
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Guerra, Neto Dival de Brito. "Equil?brio de fase de sistemas com alcanoaminas e tensoativos em alta press?o: montagem e teste de um aparato experimental." PROGRAMA DE P?S-GRADUA??O EM ENGENHARIA QU?MICA, 2016. https://repositorio.ufrn.br/jspui/handle/123456789/21423.
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O petr?leo ? uma mistura complexa, havendo predomin?ncia de hidrocarbonetos paraf?nicos, naft?nicos e arom?ticos (Freitas e Costa, 1969) al?m de outros constituintes (sulfurados, nitrogenados e oxigenados) que ocorrem normalmente na forma de compostos org?nicos. O CO2, por exemplo, estar presente em mais de 25% do ?leo extra?do da camada do pr?-sal entre as bacias de Campos e Santos. Estimativas apontam que somente nas duas ?reas com reservas delimitadas - os campos de Tupi e Iara, onde h? um ac?mulo de at? 12 bilh?es de barris de ?leo e g?s - existam 3,1 bilh?es de toneladas de CO2, um dos gases que contribuem para o aquecimento do planeta. Devido a essa grande quantidade de contaminantes (CO2, N, S, etc.) presente na mistura de hidrocarbonetos extra?da dessas bacias, ? preciso buscar novas pr?ticas de separa??o deste contaminante. Para tal desenvolvimento de novas pr?ticas ? importante um estudo constante sobre o equil?brio termodin?mico entre os constituintes do petr?leo e seus contaminantes. Com isso o objetivo ? construir um equipamento que gere condi??es suficientes para poder verificar o comportamento de fase de v?rios sistemas de interesse da ind?stria do petr?leo com seus contaminantes mais comuns, por exemplo: CO2 a alta press?o utilizando o conhecimento pr?vio do grupo Neto, 2010 de pesquisa, que deve operar em press?es e temperaturas de at? 300 bar e temperatura at? 100 graus Celsius. Alguns sistemas de interesse s?o: CO2 e alcanoaminas (monoetanolamina, dietanolamina, trietanolamina). ?gua e ?lcool laur?lico etoxilado e CO2 e alcanos com leve contamina??o de ?gua.
Oil is a complex mixture having predominantly paraffinic hydrocarbons, naphthenic and aromatic (Freitas and Costa, 1969) and other constituents (sulfur, nitrogen and oxygen) that normally occur in the form of organic compounds. The CO2, for example, be present in over 25% of the oil extracted from the pre-salt layer of the Campos and Santos basins. Estimates suggest that only in two areas with defined reserves - the Tupi and Iara, where there is an accumulation of up to 12 billion barrels of oil and gas - there are 3.1 billion tons of CO2, one of the gases that contribute to warming. Because of this large amount of contaminants (CO2, N, S, etc.) present in the mixture of hydrocarbons extracted these basins, it must find new ways of separation of this contaminant. For such development of new practices is important a constant study of the thermodynamic equilibrium between oil constituents and their contaminants. Thus the goal is to build a device that generates enough conditions to check phase behavior of various oil industry's interest systems with their most common contaminants, eg CO2 at high pressure using prior knowledge of Guerra-Neto, 2010, which must operate at temperatures and pressures up to 300 bar and temperatures up to 100 degrees Celsius. Some systems of interest are: CO2 and alcanoaminas (monoetanolamine, dietanolamine, trietanolamine). Lauryl alcohol ethoxylate and water and CO2 and alkanes with mild contamination of water.
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Henriques, Bruno José Monteiro. "Relação entre a higienização de manipuladores e superfícies e a contaminação do produto final em pequenas indústrias alimentares." Master's thesis, Universidade de Aveiro, 2014. http://hdl.handle.net/10773/14200.
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Mestrado em Biotecnologia AlimentarAs doenças de origem alimentar são provocadas, maioritariamente, por microrganismos e constituem uma das maiores preocupações de saúde pública a nível mundial. Os alimentos são os principais veículos de transmissão de doenças, o que se deve, principalmente, às más práticas de higiene e de fabrico. Nos estabelecimentos de restauração, a higiene e segurança alimentar é assegurada pela aplicação de boas práticas de higiene e de fabrico, bem como pela implementação do sistema Hazard Analysis and Critical Control Points (HACCP). A falta de conhecimento por parte dos manipuladores e, consequentemente, as más práticas de higiene e fabrico levam a que estes sejam uma das principais fontes de contaminação dos alimentos associados a doenças de origem alimentar. Os objetivos deste estágio foram a descrição das atividades desempenhadas e a avaliação das análises efetuadas no decorrer do estágio, na empresa VLM consultores, mais especificamente, no laboratório YourLab S.A.. Além disso, pretendeu-se avaliar a relação entre a higienização de manipuladores e superfícies com a contaminação do produto final, em pequenas indústrias alimentares, onde foram utilizados dados de análises de 2011 a 2014. Na análise a águas, verificou-se uma elevada percentagem de amostras consideradas “satisfatórias”, ou seja, dentro do limite estabelecido por lei. Especificamente em relação à análise dos parâmetros contagem de microrganismos a 22ºC e 37ºC, verificou-se um maior número de contaminação à temperatura 37ºC, mostrando que, nas águas, a contaminação detetada é, maioritariamente, de origem fecal. Quanto à análise de alimentos, verificou-se que, na maioria, não foram detetados microrganismos patogénicos nas amostras de refeições e produtos alimentares analisados. Verificou-se um elevado número de contaminação de produtos confecionados, o que revela que houve contaminação posterior à confeção, por contaminação cruzada, devido a más práticas de fabrico e higiene ou devido a incorreta confeção. Na análise de zaragatoas, verificou-se que, no parâmetro microrganismos a 30ºC, existe uma maior contaminação nas zaragatoas de utensílios e superfícies, facto que se deve, possivelmente, a más práticas de higiene e de fabrico. Dos resultados do trabalho referentes à avaliação da relação da contaminação de zaragatoas e alimentos recolhidos em simultâneo, verificou-se que 21,31% das amostras de produtos e zaragatoas estavam contaminadas em simultâneo, mostrando que existe uma falta de conhecimento de práticas de higiene e de fabrico por parte dos manipuladores. De entre os produtos contaminados relacionados com a contaminação de zaragatoas, verificou-se que esta correlação era maior em talhos, consequência da utilização de produtos frescos. Nas zaragatoas contaminadas relacionadas com a contaminação do produto, o nível de contaminação era maior nas zaragatoas de superfícies e utensílios, mostrando que a contaminação do produto pelos manipuladores ocorre mesmo com níveis baixos de contaminação. Tendo em conta os resultados apresentados, conclui-se que o plano HACCP não é rigorosamente seguido, uma vez que, apenas 33,77% das amostras não apresentaram contaminação nem da zaragatoa nem do produto, pelo que urge a necessidade de uma verificação mais rigorosa e frequente do plano em questão. Essa verificação deve focar-se, principalmente, no nível de conhecimento das normas de higiene e segurança alimentar, bem como no respeito perante as mesmas, por parte dos manipuladores de alimentos.
The Foodborne illnesses are caused mainly by microorganisms and constitute a major public health concern worldwide. Foods are the main vehicles of disease transmission, which is mainly due to poor hygiene practices and manufacturing. In catering establishments, hygiene and food safety are ensured by the application of good hygiene practices and manufacturing, as well as by the implementation of the Hazard Analysis and Critical Control Points (HACCP) system. The lack of knowledge by handlers and therefore bad hygiene and manufacturing practices means that they are a major source of food contamination associated with foodborne illness. The objectives of this thesis were to describe the activities performed and to evaluate the analyzes performed during the internship, in the company VLM consultants, more specifically, in the laboratory YourLab SA. In addition, it was intended to evaluate the relationship between the handlers and surfaces hygiene with contamination of the final product, in small food industries, where we used data analysis from 2011 to 2014. In the water analyze, there was a high percentage of samples considered "satisfactory", in other words, below the limit set by law. Specifically regarding the analyze, count of microorganisms at 22°C and 37°C, there was a higher number of contaminating samples at 37°C, showing that, in water, the contamination detected was mainly of fecal origin. As for food analysis, it was found that most of the product samples were free of pathogenic microorganisms. There was a large number of contaminating processed products, which reveals that there was contamination after the confection by cross-contamination due to bad hygienic and manufacturing practices or due to incorrect confection. In the analysis of microorganisms at 30ºC in swabs, it was found higher contamination of utensils and surfaces. From the results of the work related to the evaluation of the contamination of food and swabs collected at the same time, it was found that 21.31% of product samples and swabs were contaminated at the same time, showing that there is a lack of knowledge of hygiene and manufacturing practices by handlers. Within the contaminated swabs related to the product contamination, it was found that this correlation was higher in butchers, as a result of the use of fresh products. Within the contaminated swabs related to the product contamination, the contamination level was higher in surfaces and utensils, indicating that the contamination of the product by handlers occurs even with low levels of contamination. Given the results presented, we conclude that the HACCP plan is not followed strictly, only 33,77% of the products and swabs where not contaminated, so there is urgent need for a more rigorous and frequent checking of the plan in question. This verification should focus primarily on the level of knowledge of the rules of hygiene and food safety as well as respect towards them, by food handlers.
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Bocklisch, Thilo. "Optimierendes Energiemanagement von Brennstoffzelle-Direktspeicher-Hybridsystemen." Doctoral thesis, Universitätsverlag der Technischen Universität Chemnitz, 2009. https://monarch.qucosa.de/id/qucosa%3A19281.
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Die Dissertation beschreibt ein neues optimierendes Energiemanagement-Verfahren für Brennstoffzelle-Direktspeicher-Hybridsysteme. Den Ausgangspunkt bildet die Analyse der Schwankungseigenschaften spezifischer Energiezeitreihen: des Photovoltaik-Energieangebots und des elektrischen Verbrauchs von Haushalten. Konzepte zur zeitgestaffelten Zerlegung, Modellierung und Prognose werden vorgestellt.
Der zweite Teil der Dissertation beschäftigt sich mit den Grundlagen von Aufbau und Funktion eines Brennstoffzelle-Direktspeicher-Hybridsystems und präsentiert Ergebnisse experimenteller und theoretischer Untersuchungen einer PEM-Brennstoffzelle, einer Supercap-Einheit, einer Lithium-Ionen Batterie sowie eines speziell entwickelten DC/DC-Wandlers. Praxistaugliche Modelle zur Beschreibung des Klemmenverhaltens, des Ladezustands und der auftretenden Wandlungsverluste werden vorgestellt.
Der dritte Teil der Dissertation präsentiert ein neues optimierendes Energiemanagement-Verfahren. Optimierungsziele sind die Minimierung des Wasserstoffverbrauchs bei gleichzeitiger Reduzierung der dynamischen Brennstoffzellen-Beanspruchung. Das Verfahren basiert auf den drei Steuerungsebenen: Primärregelung, Sekundärregelung und Systembetriebsführung. Schwerpunkt bildet die Sekundärregelung auf der Basis einer speziellen Struktur aus Laderegler und Lastfolgeregler sowie zwei Blöcken zur aktiven Begrenzung des Leistungsgradienten und des Arbeitsbereichs der Brennstoffzelle.
Die Funktion und Leistungsfähigkeit des Energiemanagement-Verfahrens werden an einem Simulations- und an einem Experimentiersystem nachgewiesen. Anwendungsbeispiele werden gegeben.The dissertation presents a new optimizing energy management concept for fuel cell-direct storage-hybrid systems. Initially, the characteristics of specific energy time series are investigated on the basis of real measurement data. A new concept for the multi-scale analysis, modelling and prediction of fluctuating photovoltaic supply and electric load demand profiles is developed. The second part of the dissertation starts with a discussion of the benefits of and the basic coupling and control principles for fuel cell-direct storage-hybrid systems. The typical characteristics of a PEM-fuel cell, a metal hydride hydrogen storage, a lithium-ion battery and a supercap unit are presented. A new modular DC/DC-converter is described. Results from experimental and theoretical investigations of the individual components and the overall hybrid system are discussed. New practicable models for the voltage-current-curve, the state of charge behaviour and the conversion losses are presented. The third part of the dissertation explains the new energy management concept. The optimization of power flows is achieved by a control-oriented approach, employing a) the primary control of bus voltage and fuel cell current, b) the secondary control to limit fuel cell current gradient and operating range and to perform direct storage charge control, and c) the system control to optimally adjust secondary control parameters aiming for a reduction of dynamic fuel cell stress and hydrogen consumption. Results from simulations and experimental investigations demonstrate the benefits and high capabilities of the new optimizing energy management concept. Examples of stationary and portable applications conclude the dissertation.
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Barroso, M?urean Salli Tavares. "Estudo sobre processos de obten??o de extratos de Achyrocline satureioides (LAM) DC. e sua potencialidade na perfumaria." Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2011. http://tede2.pucrs.br/tede2/handle/tede/3188.
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Previous issue date: 2011-12-05Achyrocline satureioides, also known as Marcela is an aromatic herb widely used in Brazil and other South American countries, due to its medicinal properties. The marcela presents in its composition phenolic substances which are attributed antioxidant activity and volatile components. In this work we studied the processes of distillation by steam distillation and supercritical extraction, to evaluate the use of these techniques in obtaining the non-volatile and volatile extracts of marcela from its aerial parts, in order to obtain new products with aromatic notes. The extraction of essential oil of marcela was performed by employing the technique of steam distillation in five pressures (1.0, 1.5, 2.0, 2.5 and 3.0 bar), and is performed for each experimental condition the determination of the yield curve of essential oil versus time. For the extracts obtained by this technique, essential oils, the analysis was performed on the chemical composition of the extract through chromatography coupled with mass spectrometry (GC/MS). In relation to non-volatile extracts, they were obtained through the use of supercritical extraction process in four pressures (90, 100, 110 and 120 bar) at two temperatures (303.15 and 313.15 K) and each condition also yield curves were generated versus time. The extracts were assessed for their aromatic potential by assessing olfactometric. For both processes was carried out mathematical modeling of the curves, using models based on mass transfer consistent with the extraction technique that successfully represented the curves for both techniques. Regarding the assessment olfactometric both extracts volatile and non volatile aromatic potential presented, highlighting the sample extracted by steam distillation at 2.5 bar.
Achyrocline satureioides, tamb?m conhecida como marcela ? uma ervaarom?tica muito usada no Brasil e em outros pa?ses da Am?rica do Sul, devido as suas propriedades medicinais. A marcela apresenta em sua composi??osubst?ncias fen?licas as quais se atribuem atividade antioxidante e componentes vol?teis. Neste trabalho foram estudados os processos de destila??o por arraste a vapor e extra??o supercr?tica, visando avaliar o uso destas t?cnicas na obten??o dos extratos vol?teis e n?o vol?teis da marcela a partir de suas partes a?reas, a fim de se obter produtos com novas notas arom?ticas. A extra??o do ?leo essencial de marcela foi executada atrav?s do emprego da t?cnica de arraste a vapor em cinco press?es (1,0; 1,5; 2,0; 2,5 e 3,0 bar), sendo realizada para cada condi??o experimental a determina??o da curva de rendimento de ?leo essencial versus tempo. Para os extratos obtidos por essa t?cnica, os ?leos essenciais, foi realizada a an?lise da composi??o qu?mica do extrato via cromatografia gasosa acoplada com o espectr?metro de massas (CG/EM). Em rela??o aos extratos n?o vol?teis, os mesmos foram obtidos atrav?s do uso do processo de extra??o supercr?tica em quatro press?es (90, 100, 110 e 120 bar) em duas temperaturas (303,15 e 313,15 K)e para cada condi??o tamb?m foram geradas curvas de rendimento versus tempo.Os extratos obtidos foram avaliados quanto ao seu potencial arom?tico atrav?s de uma avalia??o olfatom?trica. Para ambos os processos foi realizada a modelagem matem?tica das curvas, utilizando modelos baseados na transfer?ncia de massa condizente com a t?cnica de extra??o que representaram com ?xito as curvas para ambas as t?cnicas. Em rela??o ? avalia??o olfatom?trica, tanto os extratos vol?teis como os n?o vol?teis apresentaram potencial arom?tico, destacando a amostra extra?da por arraste a vapor a 2,5 bar.
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Costa, Bruno Leonardo de Sena. "Ataque corrosivo ao cimento Portland petrol?fero classe G: estudos sobre os efeitos da carbonata??o." PROGRAMA DE P?S-GRADUA??O EM CI?NCIA E ENGENHARIA DE MATERIAIS, 2018. https://repositorio.ufrn.br/jspui/handle/123456789/24787.
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Neste trabalho o fen?meno da carbonata??o do cimento Portland ? investigado por diferentes abordagens, por?m convergindo para o mesmo objetivo: aprofundar o conhecimento dos processos e os efeitos do CO2 na matriz ciment?cia. Esse fen?meno ocorre atrav?s de rea??es qu?micas entre o ?cido carb?nico, formado pela rea??o do CO2 com a ?gua, e alguns produtos hidratados do cimento. Em subsuperf?cie, devido ao incremento de temperatura e press?o o meio se torna mais danoso, sendo assim, na ?rea de petr?leo e g?s, principalmente a cimenta??o, tem um grande interesse por esta problem?tica. Frente ao exposto, neste trabalho foram desenvolvidos e publicados tr?s artigos intitulados: [Artigo I] Efeitos do di?xido de carbono no cimento Portland: uma rela??o entre a sedimenta??o est?tica e a carbonata??o, [Artigo II] Carbonata??o em cimento Portland para po?os de petr?leo: influ?ncia do tempo de hidrata??o antes do contato com o CO2 e [Artigo III] Estudo sobre a carbonata??o em uma matriz de cimento Portland classe G em ambientes supercr?tico e saturado. No primeiro estudo foi proposto um modelo para o comportamento da sedimenta??o e da carbonata??o ocorrido em uma pasta inst?vel, onde a sedimenta??o est?tica baseia-se na mec?nica dos fluidos. No segundo estudo foram investigadas tr?s pastas com a mesma formula??o, por?m curadas durante per?odos de tempos de 8 horas, 7 dias e 28 dias antes do contato com o CO2. Os resultados mostraram processos distintos, mas com efeitos similares de carbonata??o ao final. E no ?ltimo estudo as amostras foram expostas ao mesmo tempo em CO2 supercr?tico e saturado. As an?lises mostraram resultados significativamente distintos, onde as amostras expostas ao meio saturado sofreram um ataque 35% superior ?quelas submetidas ao CO2 supercr?tico. Este trabalho apresenta estudos que buscam promover uma maior compreens?o da fenomenologia da a??o do CO2 e ao mesmo tempo dar subs?dios para o desenvolvimento de tecnologias que combatam a carbonata??o.
In this study the phenomenon of Portland cement carbonation is investigated by different approaches, but converging towards the same objective: to deepen the knowledge of the processes and the effects in the cement matrix. The phenomenon occurs through chemical reactions between carbonic acid, formed by the reaction of CO2 with water, and some hydrated products of cement. In subsurface due to the increase of temperature and pressure the medium becomes more damaging, being therefore, in the area of oil and gas, mainly cementing, has a great interest by this problematic. In view of the above, in this study three articles were developed and published entitled: [Article I] Effects of carbon dioxide in Portland cement: a relation between static sedimentation and carbonation, [Article II] Carbonation in oil well Portland cement: Influence of hydration time prior to contact with CO2 and [Article III] Study of carbonation in a class G Portland cement matrix at supercritical and saturated environments. In the first study, a model was proposed for sedimentation and carbonation behavior in an unstable slurry, the static sedimentation based on fluid mechanics. In another study, three slurries of the same formulation were investigated, but were cured for periods of 8 hours, 7 days and 28 days before CO2 contact. The results showed distinct processes, but with similar carbonation effects at the end. In addition, in one last study samples were exposed at the same time in supercritical and saturated CO2. The analyzes showed significantly different results, where the samples exposed to the saturated medium suffered a 35% higher attack. This work presents studies that seek to promote a greater understanding of phenomenology and give subsidies for the development of technologies that combat carbonation.
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Santos, ?nio Rafael de Medeiros. "Extra??o, caracteriza??o e avalia??o bioativa do extrato de Rumex acetosa." Universidade Federal do Rio Grande do Norte, 2013. http://repositorio.ufrn.br:8080/jspui/handle/123456789/15839.
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Previous issue date: 2013-08-08Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico
Studies show the great influence of free radicals and other oxidants as responsible for aging and degenerative diseases. On the other hand, the natural phenolic compounds has shown great as antioxidants to inhibit lipid peroxidation and lipoxygenase in vitro. Among these, is highlighted trans-resveratrol ( 3,5,4 `- trihydroxystilbene ) phenolic compound , characterized as a polyphenol stilbene class. The vegetables popularly known as "Azedinha" (Rumex Acetosa) has trans-resveratrol in its composition and from this, the present work aimed to study on the supercritical extraction and conventional extraction (Soxhlet and sequential) in roots of Rumex Acetosa, evaluating the efficiency of extractive processes, antioxidant activity, total phenolic content and quantification of trans-resveratrol contained in the extracts. Extractions using supercritical CO2 as solvent, addition of co-solvent (ethanol) and were conducted by the dynamic method in a fixed bed extractor. The trial met a 23 factorial design with three replications at the central point, with the variable reply process yield and concentration of trans-resveratrol and pressure as independent variables, temperature and concentration of co-solvent (% v/v). Yields ( mass of dry extract / mass of raw material used ) obtained from the supercritical extraction ranged from 0,8 to 7,63 % , and the best result was obtained at 250 bar and 90 ?C using the co-solvent 15% ethanol (% v/v). The value was calculated for YCER a flow rate of 1,0 ? 0,17 g/min resulting in 0,0469 CO2 ( g solute / g solvent ). The results of the mass yield varied between conventional extractions 0,78 % ( hexane) and 9,97 % (ethanol). The statistical model generated from the data of the concentration of trans-resveratrol performed as meaningful and predictive for a 95% confidence. GC analysis on HPLC (High Performance Liquid Chromatography), transresveratrol was quantified in all extracts and concentration values ranged between 0,0033 and 0,42 ( mg / g extract) for supercritical extracts and between 0,449 and 17,046 (mg / g extract) to conventional extractions and therefore, the Soxhlet extraction with ethanol for more selective trans-resveratrol than the supercritical fluid. Evaluation of antioxidant (radical method to sequester 2,2- diphenyl-1- picryl - hydrazyl - DPPH) the supercritical extracts resulted in EC50 values (concentration effective to neutralize 50% of free radicals) of between 7,89 and 18,43 mg/mL , while resulting in a Soxhlet extraction with EC50 values in the range of 6,05 and 7,39 mg/mL. As for quantification of the phenolic compounds (Method Spectrophotometer Folin-Ciocalteau) the supercritical extracts resulted in values between 85,3 and 194,79 mg GAE / g extract, whereas values derived from the Soxhlet extract resulted in values between 178,5 and 237,8 mg GAE / g extract. The high antioxidant activity can not be attributed solely to the presence of phenolic compounds, but the presence of other antioxidants in the existing Rumex acetosa
Estudos revelam a grande influ?ncia dos radicais livres e outros oxidantes como respons?veis pelo envelhecimento e por doen?as degenerativas. Por outro lado, os compostos fen?licos naturais tem-se apresentado como ?timos antioxidantes por inibirem a peroxida??o lip?dica e a lipooxigenase in vitro. Dentre estes, encontra-se em destaque o trans-resveratrol (3,5,4 trihidroxiestilbeno), composto fen?lico, caracterizado como um polifenol da classe estilbeno. A hortali?a popularmente conhecida como Azedinha (Rumex acetosa) possui o trans-resveratrol em sua composi??o e a partir disto, o presente trabalho teve como objetivo geral o estudo sobre a extra??o supercr?tica e a extra??o convencional (Soxhlet e sequencial) em ra?zes da Rumex acetosa, avaliando-se a efici?ncia dos processos extrativos, a atividade antioxidante, o teor de fen?licos totais e a quantifica??o do trans-resveratrol contido nos extratos. As extra??es supercr?ticas utilizaram CO2 como solvente, adicionado de co-solvente (etanol) e foram conduzidas pelo m?todo din?mico em um extrator de leito fixo. Os ensaios obedeceram a um planejamento fatorial 23 com triplicata no ponto central, tendo como vari?vel resposta o rendimento do processo e a concentra??o de trans-resveratrol e como vari?veis independentes a press?o, a temperatura e a concentra??o de co-solvente (% v/v). Os rendimentos (massa de extrato seco/ massa de mat?ria-prima utilizada) obtidos da extra??o supercr?tica variaram de 0,8 a 7,63%, sendo que o melhor resultado foi obtido a 250 bar e 90?C, com uso do co-solvente etanol a 15% (v/v). O valor de YCER foi calculado para uma vaz?o de 1,0 ? 0,17 g/min de CO2 resultando em 0,0469 (g soluto/ g solvente). Os resultados de rendimento em massa para as extra??es convencionais variaram entre 0,78% (hexano) e 9,97% (etanol). O modelo estat?stico gerado a partir dos dados de concentra??o de transresveratrol se apresentou como significativo e preditivo para uma confian?a de 95%. Atrav?s de an?lises cromatogr?ficas em CLAE (Cromatografia L?quida de Alta Efici?ncia), o transresveratrol foi quantificado em todos os extratos obtidos e os valores de concentra??o variaram entre 0,0033 e 0,42 (mg/g extrato) para os extratos supercr?ticos e entre 0,449 e 17,046 (mg/g extrato) para extra??es convencionais, sendo, portanto, a extra??o Soxhlet com etanol mais seletiva em trans-resveratrol que a supercr?tica. A avalia??o do poder antioxidante Extra??o, caracteriza??o e avalia??o bioativa do extrato de Rumex acetosa iii ?nio Rafael de Medeiros Santos, Agosto de 2013 (m?todo do sequestro do radical 2,2-difenil-1-picril-hidrazil-DPPH) dos extratos supercr?ticos resultaram em valores de EC50 (Concentra??o efetiva que neutraliza 50% dos radicais livres) compreendidos entre 7,89 e 18,43 μg/mL, enquanto que as extra??es com Soxhlet resultaram em valores de EC50 na faixa de 6,05 e 7,39 μg/mL. J? a quantifica??o dos compostos fen?licos totais (M?todo espectrofot?metro de Folin-Ciocalteau) dos extratos supercr?ticos resultaram em valores compreendidos entre 85,3 e 194,79 mg EAG/g extrato, enquanto que os valores dos extratos oriundos do Soxhlet resultaram em valores compreendidos entre 178,5 e 237,8 mg EAG/g extrato. A alta atividade antioxidante pode ser atribu?da n?o somente ? presen?a de compostos fen?licos, mas tamb?m ? presen?a de outros antioxidantes existentes na Rumex acetosa