Dissertations / Theses: 'Hydrolics'

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De, Carvalho Duarte Leandro. "Conception et optimisation d'un système hydrolien à aile oscillante passive." Thesis, Strasbourg, 2019. http://www.theses.fr/2019STRAD038.

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Dans un scénario de transition énergétique où la production et les grands réseaux de distribution d’électricité sont remis en cause, le potentiel de production au niveau des écoulements à faible vitesse est important et reste encore peu exploité. Cette thèse étudie un concept novateur d’hydrolienne permettant de répondre en partie à cette problématique : le système hydrolien à aile oscillante passive. Bioinspiré de la nage d’animaux aquatiques, ce dispositif de récupération de l’énergie cinétique des courants consiste en une aile décrivant des mouvements périodiques de pilonnement et de tangage, entièrement induits par les interactions fluide-structure. Une première partie du travail a porté sur la construction d’un modèle numérique permettant de reproduire fidèlement le comportement du système. Un prototype d’aile oscillante passive à échelle réduite a ensuite été conçu et testé dans un canal hydraulique. Grâce à une technique de réglage dynamique des paramètres structuraux, le système a pu être étudié expérimentalement sur une large gamme de paramètres mécaniques et hydrauliques. L’étude des performances énergétiques du prototype a permis d’identifier des conditions de fonctionnement optimales. Dans ces conditions, des rendements hydrauliques supérieurs à 30% ont été obtenus. Les résultats de ce travail de thèse permettent d’envisager maintenant l’installation d’un système hydrolien à aile oscillante passive en milieu naturel. En effet, les configurations optimales identifiées à l’échelle réduite peuvent s’étendre naturellement à des conditions hydrauliques réelles
Given the current energy transition conjuncture, where the electricity production and the electricity grid are challenged, the hydraulic potential of low current sites is relevant and remains under-exploited. In such context, this thesis studies a novel concept of an energy harvester device: the fully passive flapping foil turbine. Bioinspired from aquatic animals swimming technique, this hydrokinetic energy harvester consists of an oscillating foil describing periodic heaving and pitching motions, entirely induced by fluid-structure interactions. The first part of this thesis deals with the development of a numerical model for accurately simulating the harvester behavior. Then, a reduced scale prototype of the fully passive flapping foil has been designed and tested in a water channel. Thanks to an original dynamic tuning strategy of the structural parameters, experiments have been conducted for a wide range of configurations of the harvester. The investigation of the harvesting performances of the prototype helped identifying several optimized parameters sets. In such cases, hydraulic efficiencies as high as 30% have been reached. The main results of this thesis allow to consider a full scale fully passive flapping foil harvester in realistic conditions. As a matter of fact, the optimized cases identified for the reduced scale prototype can be naturally extended to real operating conditions

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Labadie, Cécile. "Analyse fine et stabilisation des hydrolats de rose et de fleur d'oranger." Thesis, Montpellier, 2015. http://www.theses.fr/2015MONTS039/document.

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Les eaux florales sont des matières premières aromatiques issues de la distillation, contenant généralement moins de 1 g/L de composés volatils leur conférant leurs propriétés organoleptiques. Elles sont utilisées principalement en industrie agroalimentaire et cosmétique. Elles sont sujettes à des problèmes d’instabilité microbienne incompatibles avec leurs applications. Ces microorganismes, leurs dynamiques, ainsi que les nutriments disponibles nécessaires à leur croissance restent mal connus. Les eaux florales sont actuellement stabilisées par ajout de conservateurs dont certains sont controversés et visent à être retirés du marché. De plus, leur efficacité dans les eaux florales n’a pas été évaluée.L’objectif de cette thèse est d’apporter une meilleure connaissance de la composition des eaux florales et de ses contaminants afin de proposer une méthode de stabilisation adaptée.La composition en huile essentielle et le microbiote de 22 échantillons d’eau de fleur d’oranger (Citrus aurantium L. ssp. amara L.) et de rose (Rosa damascena Miller et Rosa centifolia L.), provenant de différents producteurs autour du bassin méditerranéen, ont été analysés afin de déterminer les facteurs responsables de leur altération. Bien que les composés volatils soient connus pour leurs propriétés antimicrobiennes, leurs concentrations dans les hydrolats ne sont pas suffisantes pour assurer la stabilité microbiologique. En plus des composés volatils, les hydrolats contiennent des composés non-volatils tels que des sucres, entraînés vers le distillat par effet de primage ou de moussage pendant la distillation, et pouvant être utilisés comme substrat de croissance par les microorganismes. La population microbienne peut atteindre 106 à 107 UFC/mL en quelques jours à température ambiante et jusqu’à 3 mois à 5°C. Des bactéries environnementales, oligotrophes, et acido-tolérantes, appartenant principalement aux genres Pseudomonas sp. et Burkholderia sp. ont été isolées et identifiées. Parmi ces bactéries, B. vietnamiensis et Novosphingobium capsulatum ont été capables de métaboliser des composés volatiles tels que le géraniol ou l’acétate de 2-phényléthyle pour produire la 6-méthyl-5-heptèn-2-one ou le 2-phényléthanol, et modifier ainsi les propriétés organoleptiques des hydrolats. Enfin, la capacité de croissance de bactéries pathogènes et d’altération dans les hydrolats a été évaluée, et différents conservateurs ont été testés sur les souches capables de se multiplier dans les hydrolats.Une distillation aseptique et un conditionnement stérile permettrait d’assurer la stabilité des hydrolats sans ajout de conservateurs. En l’absence de conditions aseptiques, l’ajout de conservateurs est nécessaire pour assurer la stabilité des hydrolats
Hydrosols are hydrodistillation products mainly used as food flavoring agents or ingredient in cosmetics. They contain less than 1 g/L of dispersed essential oils giving the organoleptic properties. These are subjected to microbial proliferation that can prevent use due to non-compliance to professional microbiological standards. The microorganisms, their growth dynamics, and the available nutrients in hydrosols remain unknown. Hydrosols can contain few preservatives, but there is no data about their efficiency in hydrosols.The aim of this study was to have a better knowledge on hydrosols composition, their microbiota, and spoilage conditions, in order to propose an adapted stabilization method.The composition in volatile compounds and the microbiota of 22 hydrosol samples of Citrus aurantium L. ssp. amara L. (orange blossom), Rosa damascena Miller (rose D.), and Rosa centifolia L. (rose C.) flowers were analyzed to determine factors responsible for decay. Some non-volatile compounds were likely carried over during distillation by a priming and foaming effect, and could be used as nutrients by microorganisms. Concentrations of volatile compounds in hydrosols are not high enough to prevent microbial proliferation, and bacteria concentrations can reach up to 106 CFU/mL in both hydrosols. The isolated microbial population was composed of oligotrophic Gram-negative bacteria, arranged in four major genera: Pseudomonas sp., Burkholderia cepacia complex, and presumably two new genera belonging to Acetobacteraceae and Rhodospirillaceae. Among those bacteria, Burkholderia vietnamiensis and Novosphingobium capsulatum were able to metabolize volatile compounds, such as geraniol to produce 6-methyl-5-hepten-2-one or geranic acid, or 2-phenylethyl acetate to produce 2-phenylethanol. Finally, the growth potential of a range of bacteria isolated from hydrosols and of pathogenic micro-organisms was evaluated, then the anti-microbial activity in nutrient broth and/or in hydrosols of a range of chemical preservatives authorized for food and cosmetic applications was tested.Additional hurdles such as chemical preservatives or aseptic packaging will be necessary to insure microbial stability

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Melloni, Mattia <1989&gt. "From Lignocellulosic Biomass to Rare Sugars: Hydrolisis and Isomerization with Heterogeneous Catalysts." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amsdottorato.unibo.it/8056/1/Melloni_Mattia_tesi.pdf.

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The PhD project presented in this thesis focused on two research topics turned to contribute to the development of a modern model of production, that is able to reduce the environmental impact of the chemical industry. For this purpose, preparation and characterization of heterogeneous catalysts for the transformation of renewable raw materials into valuable chemicals has been studied. The first part of the work concerned the conversion of lignocellulosic biomass, the most abundant renewable source presents on Earth, into monosaccharides and bio-building blocks, such as HMF, furfural and levulinic acid. Solid acid metal phosphate catalysts were synthetized for lignocellulose transformation; the catalytic behaviors shown by prepared metal phosphates were correlated to their physical-chemical properties: in particular, the role of acid features on the hydrolysis reaction has been studied. The synthesis of interesting industrial monosaccharides that cannot be obtained in appreciable amount from natural resources, called rare sugars, was the topic of the second part of the work. For this purpose, the rearrangement of glucose by the use of heterogeneous catalysts containing titanium was studied: especially, the influence of the different Ti species on products distribution has been investigated.

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Stevenson, Pierre. "Contribution au développement d’un concept d’hybridation énergétique : structures de commande d’un système intégré éolien-hydrolien." Thesis, Le Havre, 2015. http://www.theses.fr/2015LEHA0001/document.

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Ce mémoire traite de la problématique d’hybridation éolienne-hydrolienne. Elle pose d’abord l’hypothèse d’une éolienne basée sur une Machine Synchrone à Aimants Permanents (MSAP) et une hydrolienne utilisant une Machine Asynchrone à Double Alimentation (MADA). Puis, elle présente la modélisation des différents éléments qui composent chacune des chaines de conversion, de la turbine à la connexion au réseau en passant par la machine électrique et les convertisseurs statiques. Des stratégies de commande y sont aussi développées. Celles-ci permettent d’extraire le maximum d’énergie tout en tenant compte des limites des systèmes. La thèse étudie également deux possibilités de couplage d’une éolienne et hydrolienne qui toutes deux utilisent une MSAP. Les résultats de simulation obtenus des modèles que nous avons développés dans l’environnement Matlab/Simulink/ SimpowerSystem permettent de valider les stratégies de commande utilisées et de conclure qu’un bon choix serait d’opter pour le couplage au niveau du bus continu
AThis thesis addresses the problem of wind-tidal turbines hybridization. It first raises the hypothesis of a wind turbine based on Synchronous Permanent Magnet Machine (PMSM) and a tidal using a Double-Fed Induction Generator (DFIG). So, it presents the modeling of different elements that make up each system studied, from the turbine to the network connection through the electric machine and static converters. Control strategies are also developed. These are used to extract the maximum energy while taking into account the limitations of the systems. The thesis also examines two possible coupling of wind and tidal turbines which both use a PMSM. The simulation results of the models that we have developed in Matlab / Simulink / SimpowerSystem allow to validate the control strategies and conclude that a good choice would be to opt for coupling to the DC bus

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Bjarne, Katrin. "Optimerad förfällning med hydrolys och fermentation av primärslam för utvinning av kolkälla till efterdenitrifikation." Thesis, Uppsala universitet, Avdelningen för systemteknik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-210613.

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Att rena vatten är kostsamt, från både en ekonomisk och miljömässig synpunkt, då behovet av fällningskemikalier, kolkällor och energi är stort. Det är därför önskvärt att titta på alternativa lösningar som möjliggör reningsverk att bli mer självförsörjande och kretsloppsanpassande. Hammarby Sjöstadverket är en pilotanläggning för avloppsvattenrening belägen i Stockholms sydöstra stadsdel i Henriksdal och ägs av IVL, Svenska Miljöinstitutet samt KTH. Sedan pilotanläggning byggdes år 2002, har flera olika reningstekniker utvärderats där fokus ligger på att sträva efter miljövänliga och kretsloppsanpassade system. Bland annat har en förfällningsteknik, så kallad trepunktsfällning utvärderats. Trepunktsfällningen innebär att ett metallsalt följt av två olika polymer tillsätts i flockningskammaren i inbördes ordning för att på så sätt kunna reducera en högre halt av det organiska materialet. Tidigare fällningsförsök på Hammarby Sjöstadsverket, har visat på att trepunktsfällningen kan avskilja det organiska materialet med upp till 90 %, vilket kan jämföras med en avskiljning på endast 75 % med vanlig förfällning. Detta examensarbete syftar till att validera redan framtagna resultat inom trepunktsfällning samt att genom biologisk hydrolys av primärslam, utvinna en kolkälla till efterdenitrifikationen innehållande så höga halter flyktiga fettsyror, Volatile Fatty Acids, (VFA) som möjligt samt undersöka kostnaderna för ett avloppsreningsverk med trepunktsfällning, biogasutvinning och uttag av intern kolkälla från primärslammet vid en uppskalning motsvarande 100 000 personekvivalenter. Fällningsförsöken utfördes i pilotskala med fällningskemikalien PAX XL-36 kombinerat med en lågmolekylär organisk polymer, Purfix-120, följt av en högmolekylär oorganisk polymer Superflock C-494. Syftet med trepunktsfällningen var att validera redan framtagna resultat inom trepunktsfällning och på så sätt avskilja så stora mänger organiskt material som möjligt i förfällningen så att ett primärslam innehållande en hög halt Chemical Oxygen Demand (COD) erhålls. Två olika doseringar med PAX XL-36 testades, 145 respektive 193,5 g/m3. Bäst reduktion av COD och fosfor erhölls då 193 g/m3 PAX XL-36 kombinerades med 60 g/m3 Purfix-120 samt 0,025 g/m3 Superflock C-494. Då erhölls en COD-reduktion på 75 % samt en totalfosforreduktion på 83 %. Genom hydrolys av primärslam i laboratorieskala undersöktes torrsubstanshalter (TS-halter) på 1, 2 respektive 3 % och uppehållstider på upptill åtta dagar. Syftet med hydrolysen var i detta fall att undersöka vilken torrsubstanshalt samt vilken uppehållstid som gav högst produktion av VFA. Försöken visade att en TS-halt på 3 % producerade högst andel VFA och att produktionen av VFA för samtliga TS-halter var som störst under dygn två. VFA- och COD-produktionen ökade linjärt för samtliga TS-halter fram till och med dygn fem. Efter dygn fem började produktionen av VFA och COD för TS-halterna 1 och 2 % avta något. TS 3 % visade dock inte samma avtagande trend för VFA. Även den dagliga ammoniumhalten och pH undersöktes. Ammoniumhalten ökade i takt med att VFA-halten ökade. pH hade generellt sett en avtagande trend. Fyra olika denitrifikationsförsök genomfördes i laboratorieskala med det uttagna hydrolysatet där den tillsatta COD-halten antingen var 3,3 eller 4 gånger den initiala nitratkvävekoncentrationen. Syftet med denitrifikationsförsöken var att utvärdera det framtagna hydrolysatets funktion som en kolkälla. Denitrifikationsförsöken uppvisade denitrifikationshastigheter mellan 4,3 och 7 mg NO3-N/g volatile suspended solids*h med kol-kvävekvoter (C/N-kvoter) mellan 3,9 och 12,3 mg COD/mg NO3-N. Lägst C/N-kvot erhöll lägst denitrifikationshastighet. Dock kunde inte slutsatsen dras att högst C/N-kvot gav högst denitrifikatioshastighet. Även de ekonomiska aspekterna undersöktes i syfte att utreda kostnaderna för ett avloppsreningsverk med trepunktsfällning, biogasutvinning och uttag av intern kolkälla från primärslammet vid en uppskalning motsvarande 100 000 personekvivalenter. Uttaget av en intern kolkälla skulle trots förlust i biogasutvinning vara ekonomiskt gynnsamt. Vinsten, i form av att ej behöva inhandla en extern kolkälla, i detta fall etanol, motsvarar biogasförlustens belopp. Trepunktsfällningens fällningskemikaliekostnader var den största posten och uppgick till 8 060 000 kr. Denna kostnad kontra mindre energiförbrukning i biosteget undersöktes också. Här uppgick besparingarna i biosteget till ca 1/8 av fällningskemikaliekostnaderna. Då trepunktsfällningen endast kunde ge en 75-procentig COD-reduktion, vilket motsvarar en vanlig förfällning, anses trepunktsfällningen vara ekonomisk ogynnsam då den medför extra kostnader av polymerer. Istället borde trepunktsfällningen ersättas med en förfällning. Sammanfattningsvis kan det konstateras att en intern kolkälla i form av hydrolyserat primärslam skulle kunna ersätta en extern kolkälla rent funktionsmässigt. Dock måste åtgärder göras för att minimera produktionen av ammonium under slamhydrolysen. Ur ett ekonomiskt perspektiv skulle utvinningen av en intern kolkälla endast vara ekonomisk gynnsam då trepunktsfällningen ersätts med förfällning.
Water treatment is costly, from both an economic and environmental point of view, since the need for precipitation chemicals, carbon sources and energy is high. It is therefore desirable to look for alternative solutions that enable plants to be more self-sustaining. Hammarby Sjöstadsverket is a pilot plant for wastewater treatment located in Henriksdal, a southeastern neighborhood of Stockholm. The plant is owned by IVL, Svenska Miljöinstitutet and Kungliga Tekniska Högskolan (KTH). Since the pilot plant was built in 2002, several different cleaning techniques have been evaluated with focus on striving for eco-friendly and eco-adapted systems. For instance, a pre-precipitation technique, so-called three step precipitation have been evaluated. The three step precipitation implicates that a metal salt followed by two different polymers are added in the flocculation chamber in the particular order to thereby enable to reduce a higher content of the organic material. In previous precipitation tests at Hammarby Sjöstadsverket, one managed to remove up to 90 % of the organic material using the three step precipitation (IVL, Hammarby Sjöstadsverket, 2011). This can be compared to a removal of only 75 % with ordinary pre-precipitation. This thesis aims to validate already obtained results within three step precipitation and with biological hydrolysis of primary sludge, extract a carbon source for post-denitrification containing as high concentrations of Volatile Fatty Acids (VFA) as possible and to investigate the cost of a wastewater treatment plant with three step precipitation, biogas generation and collection of internal carbon source from primary sludge at an upscaling corresponding to 100,000 person equivalents. Precipitation experiments were carried out in pilot scale with the precipitation chemicals, PAX-XL 36, combined with a low molecular weight organic polymer, Purfix-120, followed by a high molecular weight inorganic polymer, Super Flock C-494. The purpose of the three step precipitation was to validate the already produced results within three step precipitation and thus separate as large amounts of organic material as possible in the precipitation so that a primary sludge containing a high chemical oxygen demand (COD) can be obtained.Two different dosages of Purfix-120 were tested: 45 and 60 g/m3. The best reduction of COD and phosphorus were obtained when 193 g/m3 PAX XL-36 was combined with 60 g/m3 Purfix-120 and 0.025 g/m3 Super Flock C-494. Hereby a COD reduction of 75 % and a total phosphorus removal of 83 % were obtained. By hydrolysis of primary sludge in batch experiments Total Solid (TS) concentrations of 1, 2 and 3 % and residence times of up to eight days were examined. The purpose of the hydrolysis in this case was to investigate which TS concentration and residence time that gave the highest production of VFA. The experiments showed that a TS concentration of 3 % produced the highest amount of VFA and that the VFA production of the three different TS concentrations peaked at the second day. The VFA and COD production increased linearly for the three TS concentrations up until day five. After day five the COD and VFA production, for the TS concentrations of 1 and 2 %, started to decrease slightly. However TS 3 % did not show the same declining trend for VFA. Furthermore the daily ammonium and pH were investigated. As the VFA and COD concentration increased the ammonium concentration increased as well. pH had overall a decreasing trend. Four different denitrification tests were performed in batch experiments with the extracted hydrolyzate. The added COD content from the hydolyzate was either 3.3 or 4 times the initial nitrate concentration. The denitrification tests showed denitrification rates between 4.3 and 7 mg NO3-N / g volatile suspended solids * h with carbon-nitrogen ratios (C/N ratio) between 3.9 and 12.3 mg COD/mg NO3-N. The lowest C/N ratio received the lowest denitrification rate. However, it could not be concluded that the maximum C/N ratio had the highest denitrification rate. Futhermore the financial aspects were examined in order to investigate the cost of a wastewater treatment plant with three step precipitation, biogas generation and collection of internal carbon source from primary sludge at an upscaling corresponding to 100,000 person equivalents. The extraction of an internal carbon source would, despite loss of biogas production, be economically beneficial. Gain, in terms of not having to purchase an external carbon source, in this case ethanol, amounts to the amount of the biogas loss. The three step precipitation chemical costs were the largest item, amounting to 8,060,000 SEK. This cost versus less energy utilization in the biological step was also examined. In this case the savings in the biological step amounted to about 1/8 of precipitation chemical cost. Since the three step precipitation only managed to remove 75 % of the COD, a removal which corresponds to an ordinary pre-precipitation, the three step precipitation is considered to be economically unfavorable as it involves additional costs of polymers. Instead the three step precipitation should be replaced with a pre-precipitation. In summary it can be stated that an internal carbon source in the form of hydrolyzed primary sludge could replace an external carbon source in a functional way. However, steps must be taken to minimize the production of ammonium during sludge hydrolysis. From an economic perspective, the extraction of an internal carbon source would only be economical favorable if the three step precipitation is replaced with pre-precipitation.

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Smuga-Kogut, Małgorzata. "Method for the preparation of bioethanol from rye straw using ionic liquid : PhD thesis summary : [synopsis]." Rozprawa doktorska, [s.n.], 2014. http://dlibra.tu.koszalin.pl/Content/1319.

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Akdogan, Amanda. "Biologisk slamhydrolys vid Ekeby reningsverk för framtagning av intern kolkälla." Thesis, Karlstads universitet, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-80009.

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Camili, Eloneida Aparecida [UNESP]. "Parâmetros operacionais do processo de produção de etanol a partir de polpa de mandioca." Universidade Estadual Paulista (UNESP), 2010. http://hdl.handle.net/11449/101669.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
A crescente necessidade de ampliar de modo sustentável o uso de fontes renováveis de energia, para proporcionar maior segurança ao suprimento energético, e reduzir os impactos ambientais associados aos combustíveis fósseis, encontra no bioetanol uma alternativa viável economicamente e com significativo potencial de expansão. Atualmente, a produção de etanol de mandioca por processo fermentativo, visando sua utilização como combustível veicular, é limitada, principalmente em comparação a processos que utilizam a cana-de-açúcar como matéria prima, e o eficiente uso do bagaço gerado. Todavia, a possibilidade de se produzir etanol refinado a partir de mandioca in natura vem obtendo o interesse de alguns industriais da área, devido ao fato do produto apresentar um maior valor de mercado que o etanol carburante. Este trabalho teve como finalidade contribuir para a inovação do processo de obtenção de etanol a partir da mosturação de raízes da mandioca, a etapa de fermentação e caracterização dos produtos, utilizando um sistema de produção em escala laboratorial que simulou as operações numa planta industrial. Buscou-se definir as melhores condições de tempos de processo, catalisadores enzimáticos e concentrações de substrato. No sentido de promover uma inovação tecnologicamente viável, traçou-se um planejamento experimental que minimizasse as operações de preparo, definindo as condições mais adequadas para o processo de hidrólise e fermentativo. A primeira etapa do trabalho consistiu em estudar o tempo de sacarificação do amido contido na polpa de raízes de mandioca, utilizando um delineamento central composto rotacional (DCCR) 23 onde o valor da variável dependente (concentração de glicose do sacarificado) ficou em função das variáveis independentes (concentração de matéria seca, concentração de enzima dextrinizante e concentração...
Based on the increasing need of enlarging the use of renewable sources sustainably to provide greater security for energy supply and reduce environmental impacts associated with fossil fuels, bioethanol represents an economically viable alternative with significant potential of expansion. Currently, ethanol production from cassava through fermentation aimed at its use as vehicle fuel has been limited, mainly compared to processes employing sugarcane as raw material and the efficient use of the generated bagasse. However, the possibility of producing refined ethanol from cassava in natura has attracted the interest of some industries in the area, since this product has a higher market value than combustible ethanol. This work aimed to contribute to the innovation of the process of obtaining ethanol from cassava root mashing, as well as the stage of fermentation and characterization of products, using a production system in laboratory scale simulating operations in an industrial plant. We attempted to define the best... (Complete abstract click electronic access below)

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Tekobon, Jerry. "Système multi physique de simulation pour l'étude de la production de l'énergie basée sur le couplage éolien offshore-hydrolien." Thesis, Le Havre, 2016. http://www.theses.fr/2016LEHA0031/document.

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Les travaux de thèse concernent le développement d’une plateforme d’émulation temps réel destinée aux études théoriques et expérimentales des systèmes hybrides éolien- hydrolien. Diverses architectures de couplages énergétiques sont traitées sur la base des similitudes fonctionnelles des deux systèmes et par des concepts d’émulation à la fois numériques et expérimentaux. La notion de simulation en temps « accéléré » a été développée. Le concept a été validé sur la plateforme expérimentale en utilisant l’évolution de la puissance moyenne délivrée par une turbine éolienne de petite puissance. Cette approche pourra permettre de réduire les temps d’observation des campagnes de mesure, d’accélérer les études sur le potentiel éolien des sites en développement. Nous avons développé également deux types de couplage du système hybride éolien-hydolien. Un couplage électrique basé sur la connexion en parallèle sur un bus continu des deux turbines. Nous avons développé un concept innovant d’un couplage électromécanique basé sur l’utilisation d’une seule génératrice asynchrone sur laquelle sont simultanément couplés les arbres de la turbine éolienne et de la turbine hydrolienne. Pour cela, un servomoteur à commande vectorielle nous a servi à émuler la turbine éolienne pendant qu’un moteur synchrone nous a servi d'émulateur de turbine hydrolienne. L’arbre de la génératrice sert de couplage mécanique entre les deux systèmes. Nous avons mis en évidence dans les expérimentations effectuées, la complémentarité des productions électriques des deux systèmes, et également le besoin de leur adjoindre un système de stockage pour palier à une baisse simultanée de deux productions d’énergie
The thesis work concerns the development of a real-time emulation platform for theoretical and experimental studies of offshore wind and tidal power hybrid systems. Various energy coupling architectures are processed on the basis of the functional similarities of two systems and by both numerical and experimental emulation concepts. The notion of accelerated time used for real time simulation has been developed. The concept was validated on the experimental platform using the evolution of the mean power delivered by a small wind turbine. This approach can reduce the observation times of the measurement campaigns and could accelerate the studies for the wind potential of developing sites. We have also developed two types of coupling of the wind-tidal hybrid system. An electrical coupling based on the connection in parallel on a continuous bus of two turbines. We have developed an innovative concept of an electromechanical coupling based on the use of a single asynchronous generator on which the wind turbine and tidal turbine are simultaneously coupled. For this purpose, a vector-controlled servomotor was used to emulate the wind turbine while a synchronous motor was used as a tidal turbine emulator. The generator shaft is used as a mechanical coupling between the two systems. We have demonstrated in the experiments that we have developed the complementarity of the electrical productions of the two systems; we highlighted the need to add a storage system to compensate the simultaneous decrease of the two energy productions. The real time simulations results allow us to validate the feasibility of such a coupling

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Karlsson, Erik, and Benjamin Sjöström. "Ekolodsmätningars förhållning mot olika insamlings- och interpolationsmetoder : En fallstudie på sjön Öjaren, Sandviken." Thesis, Högskolan i Gävle, Samhällsbyggnad, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-32917.

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Traditionellt har större fartyg bestyckade med ekolod använts för att utföra batymetriska mätningar av sjö- och havsbottnar. Att utföra mätningar i grunda vatten har varit problematiskt eftersom större fartyg inte kan nå dessa grunda vatten. För att tackla det problemet har mindre obemannade ytfarkoster (USV) utvecklats för att mäta grunda vatten. Dessa USVs hjälper även till vid områden nära stenar som inte har fått uppdaterade djupvärden. Den här undersökningens syfte är att utvärdera hur en Seafloor HydroLite TM enkelstrålsekolod monterad på en USV skiljer sig från insamlingsmetoderna GNSS och med måttband. Den syftar även till att utvärdera vilken interpolationsteknik som är mest lämpad för skapande av djupmodeller med enkelstrålsekolodsdata. Det kommer också studeras hur tvärsektioner påverkar djupmodellerna skapade med enkelstrålsekolod. De experimentella mätningarna med GNSS, måttband och enkelstrålsekolod utfördes i sjön Öjaren som ligger utanför Sandviken. I undersökningen inmättes totalt 91 punkter med GNSS och måttband samt 8 mätstråk och 9 tvärsektioner med enkelstrålsekolod monterad på en USV. Djupmodellerna skapades i Surfer 10 med interpolationsteknikerna kriging, natural neighbor och triangulation with linear interpolation. Alla beräkningar genomfördes i Microsoft Excel och data insamlat med måttband ansågs vara det sanna värdet vid jämförelsen mellan insamlingsmetoderna. Resultaten visade att djupmodellerna skapade med GNSS-data är snarlika till djupmodellerna skapade med måttbandsdata samt att djupmodellerna med GNSS-data visar på den minsta skillnaden mot djupmodellerna skapade med enkelstrålsekolodsdata. Resultatet från jämförelsen mellan interpolationsteknikerna visar på att användandet av de olika interpolationsteknikerna inte har en signifikant påverkan på djupmodellen. Våra slutsatser av undersökningen blev att användande av ett enkelstrålsekolod kan bidra till att skapa en mer detaljerad djupmodell än om enbart GNSS eller måttbandsdata används. Det är också en mer kostnadseffektiv metod eftersom mer data kan samlas in på kortare tid. Det kan dock uppstå felmätningar vid insamlade av data med enkelstrålsekolod som kan vara svåra att upptäcka. Tilläggande av tvärsektioner kan bidra till att skapa en ännu mer detaljerad djupmodell och kan användas som kontrollpunkter vid kontroll av enkelstrålsekolodsdata.
Traditionally, large vessels armed with echo sounders have been used to conduct bathymetric surveys of the seas and oceans. Conducting surveys of shallow water have been troublesome since larger vessels cannot reach and survey shallow waters. To tackle that problem smaller unmanned surface vessels (USV) have been developed to survey shallow waters. It also helps in the areas closest to rocks that do not have updated depth measurements. This study aims to assess how a Seafloor HydroLite TM single-beam echo sounder mounted on a USV differs from other surveying methods. It also aims to evaluate which interpolation methods is most suitable for creating depth models by utilizing single-beam echo sounder data. It will also be studied how cross section lines affect the created depth using the USV. The experimental surveys with GNSS, measuring tape and single-beam echo sounder were used in the lake Öjaren that is located outside of Sandviken. In this study a total of 91 points were collected with GNSS and measuring tape and 8 sounding lines and 9 cross sections lines were collected using echo sounder mounted on the USV. The depth models were created in Surfer 10 using different interpolation methods i.e. kriging, natural neighbor and triangulation with linear interpolation. All calculation were performed in Microsoft Excel and the measurements collected with measuring tape were assumed as a “true” value to evaluate the different surveying techniques. The results showed that the depth model obtained using GNSS data is close to the depth model created using measuring tape data and shows lowest difference in comparison to the USV technique. The results from the comparison between interpolation methods showed that the use of different interpolation methods not have a significant impact on the depth model. The study concludes that the use of a single-beam echo sounder can help to create a more detailed depth model than using GNSS or measuring tape. It is also a cost effective method that helps collect more data in a short time. Though, some errors can appear in the data collected using the single-beam echo sounder that can be hard to detect. The cross section lines can contribute to a more detailed depth model and can be used as control points.

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Camili, Eloneida Aparecida 1980. "Parâmetros operacionais do processo de produção de etanol a partir de polpa de mandioca /." Botucatu : [s.n.], 2010. http://hdl.handle.net/11449/101669.

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Orientador: Cláudio Cabello
Banca: Waldemar Gastoni Venturini Filho
Banca: Jorge Horii
Banca: Magali Leonel
Banca: Ana Paula Cerino Coutinho
Resumo: A crescente necessidade de ampliar de modo sustentável o uso de fontes renováveis de energia, para proporcionar maior segurança ao suprimento energético, e reduzir os impactos ambientais associados aos combustíveis fósseis, encontra no bioetanol uma alternativa viável economicamente e com significativo potencial de expansão. Atualmente, a produção de etanol de mandioca por processo fermentativo, visando sua utilização como combustível veicular, é limitada, principalmente em comparação a processos que utilizam a cana-de-açúcar como matéria prima, e o eficiente uso do bagaço gerado. Todavia, a possibilidade de se produzir etanol refinado a partir de mandioca in natura vem obtendo o interesse de alguns industriais da área, devido ao fato do produto apresentar um maior valor de mercado que o etanol carburante. Este trabalho teve como finalidade contribuir para a inovação do processo de obtenção de etanol a partir da mosturação de raízes da mandioca, a etapa de fermentação e caracterização dos produtos, utilizando um sistema de produção em escala laboratorial que simulou as operações numa planta industrial. Buscou-se definir as melhores condições de tempos de processo, catalisadores enzimáticos e concentrações de substrato. No sentido de promover uma inovação tecnologicamente viável, traçou-se um planejamento experimental que minimizasse as operações de preparo, definindo as condições mais adequadas para o processo de hidrólise e fermentativo. A primeira etapa do trabalho consistiu em estudar o tempo de sacarificação do amido contido na polpa de raízes de mandioca, utilizando um delineamento central composto rotacional (DCCR) 23 onde o valor da variável dependente (concentração de glicose do sacarificado) ficou em função das variáveis independentes (concentração de matéria seca, concentração de enzima dextrinizante e concentração... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Based on the increasing need of enlarging the use of renewable sources sustainably to provide greater security for energy supply and reduce environmental impacts associated with fossil fuels, bioethanol represents an economically viable alternative with significant potential of expansion. Currently, ethanol production from cassava through fermentation aimed at its use as vehicle fuel has been limited, mainly compared to processes employing sugarcane as raw material and the efficient use of the generated bagasse. However, the possibility of producing refined ethanol from cassava in natura has attracted the interest of some industries in the area, since this product has a higher market value than combustible ethanol. This work aimed to contribute to the innovation of the process of obtaining ethanol from cassava root mashing, as well as the stage of fermentation and characterization of products, using a production system in laboratory scale simulating operations in an industrial plant. We attempted to define the best... (Complete abstract click electronic access below)
Doutor

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Sazib, Nazmus Shams. "Physically Based Modelling of the Impacts of Climate Change on Streamflow Regime." DigitalCommons@USU, 2016. https://digitalcommons.usu.edu/etd/5067.

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Understanding the implications of climate change on streamflow regime is complex as changes in climate vary over space and time. However, a better understanding of the impact of climate change is required for identifying how stream ecosystems vulnerable to these changes, and ultimately to guide the development of robust strategies for reducing risk in the face of changing climatic conditions. Here I used physically based hydrologic modeling to improve understanding of how climate change may impact streamflow regimes and advance some of the cyberinfrastructure and GIS methodologies that support physically based hydrologic modeling by: (1) using a physically based model to examine the potential effects of climate change on ecologically relevant aspects of streamflow regime, (2) developing data services in support of input data preparation for physically based distributed hydrologic models, and (3) enhancing terrain analysis algorithms to support rapid watershed delineation over large area. TOPNET, a physically based hydrologic model was applied over eight watersheds across the U.S to assess the sensitivity and changes of the streamflow regime due to climate change. Distributed hydrologic models require diverse geospatial and time series inputs, the acquisition and preparation of which are labor intensive and difficult to reproduce. I developed web services to automate the input data preparation steps for a physically based distributed hydrological model to enable water scientist to spend less time processing input data. This input includes terrain analysis and watershed delineation over a large area. However, limitations of current terrain analysis tools are (1) some support only a limited set of specific raster and vector data formats, and (2) all that we know of require data to be in a projected coordinate system. I enhanced terrain analysis algorithms to extend their generality and support rapid, web-based watershed delineation services. Climate change studies help to improve the scientific foundation for conducting climate change impacts assessments, thus building the capacity of the water management community to understand and respond to climate change. Web-based data services and enhancements to terrain analysis algorithms to support rapid watershed delineation will impact a diverse community of researchers involved terrain analysis, hydrologic and environmental modeling.

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Leyton, Pacheco Allison Francis. "Design of an extraction process of phlorotannins and carbohydrate Macrocystis pyrifera, integrating the use of marine enzymes in the step of carbohydrate hydrolisis." Tesis, Universidad de Chile, 2016. http://repositorio.uchile.cl/handle/2250/141745.

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Tesis para optar al grado de Doctora en Ciencias de la Ingeniería, Mención Ingeniería Química y Biotecnología
La macroalga parda Macrocystis pyrifera es una especie de algas marinas que posee una amplia distribución en aguas templadas y frías tanto del hemisferio norte como sur, formando bosques productivos de alta diversidad biológica. En Chile M. pyrifera se distribuye a lo largo de la costa desde Iquique al Cabo de Hornos. La importancia comercial de esta especie se ha incrementado en la última década, especialmente en la extracción de alginato y su uso como alimento de abalones. El alga se compone principalmente de carbohidratos heterogéneos (> 50% peso seco del alga) como fucoidano, alginato y laminarina, los cuales pueden ser empleados como plataforma para la producción de variados compuestos. Además, posee compuestos polifenólicos únicos en su especie conocidos como florotaninos los cuales han sido ampliamente estudiados por sus beneficios potenciales para la salud como anti-oxidantes, anti-cáncer, anti-diabetes, anti-inflamación y anti-microbianas, entre otras. En este trabajo se estudió el diseño de un proceso de extracción de florotaninos y carbohidratos desde M. pyrifera, usando enzimas marinas en la etapa de hidrolisis de los carbohidratos. Para lo cual se procedió en un primer paso a determinar condiciones que mejoran la extracción de florotaninos desde el alga, tales como temperatura de secado del alga, parámetros de extracción e identificación de los compuestos. En una segunda etapa se optimizó la producción de enzimas carbohidrasas, alginato liasa, fucoidanasa y 1,3-β-D-glucanasa, desde microorganismos marinos asociado a la macroalga, para ser empleadas posteriormente en el pre-tratamiento enzimático de M. pyrifera. En una tercera etapa se determinó condiciones de extracción simultánea de carbohidratos y florotaninos desde el alga incorporando la etapa previa de pre-tratamiento enzimático. Finalmente, se estudió la separación de florotaninos desde el extracto final usando resinas macroporosas. La evaluación de estas etapas permitió determinar que un pre-tratamiento enzimático del alga con carbohidrasas, producidas por el hongo marino Alternaria sp, a 25°C por 36 horas a un pH 7.0 y una razón alga/extracto enzimático de 1/20, seguido por extracción alcalina de fase solida con NaOH 0.5N a 100°C por 180 min en una razón sólido/líquido de 1/20. Obteniendo un extracto con concentración final de 452 mg carbohidrato/g alga y 2.14 mg florotaninos/g alga, lo cual representa un rendimiento de extracción específico de 89.6% para carbohidratos y 21.4% para florotaninos. Posteriormente, el uso de resina XAD-16N permitió la separación del 42% de los florotaninos desde el extracto. La fracción enriquecida en florotaninos fue liofilizada presentando una concentración de 14.2 mg florotaninos/g liofilizado.
The brown macroalgae Macrocystis pyrifera is a kind of seaweed that has a wide distribution in temperate and cold waters of both the Northern and Southern hemispheres, forming productive forests of high biological diversity. In Chile M. pyrifera it is distributed along the coast from Iquique to Cape Horn. The commercial importance of this species has increased in the last decade, especially in alginate extraction and use as food abalones. M. pyrifera (>50 % of the alga dry weight) as fucoidan, laminarin and alginate, which can be used as a platform for the production of many compounds is mainly composed of heterogeneous carbohydrate. In addition, the brown seaweeds have unique polyphenolic compounds in their species known as phlorotannins which have been widely studied for their potential health benefits such as prevention of oxidative stress-mediated radical, anti-cancer, anti-diabetes, anti-inflammation and anti-microbial, among others. In this work was studied in this paper the design of an extraction process phlorotannins and carbohydrates from Macrocystis pyrifera, using marine enzymes in the hydrolysis step carbohydrates. For which we proceeded in a first step to determine the conditions that improve phlorotannins extraction from algae such as seaweed drying temperature, parameters extraction and identification of compounds. In a second stage production carbohydrate active enzymes, alginate lyase, fucoidanase and 1,3-β-D-glucanase was optimized from microorganisms associated with marine macroalgae, to be employed subsequently in the enzymatic pretreatment of M. pyrifera. In a third stage of simultaneous extraction conditions of carbohydrate and phlorotannins was determined from M. pyrifera incorporating the previous stage enzymatic pretreatment. Finally, the separation of phlorotannins was studied from the final extract using macroporous resins. Evaluation of these stages allowed to determine that an enzymatic pretreatment with carbohydrate active enzymes, alginate, fucoidanasa and 1,3-β-D-glucanase produced by the marine fungus Alternaria sp, at 25°C for 36 hours pH 7.0 and algae/enzyme extract of 1/20, followed by alkaline extraction of the solid phase with 0.5 N NaOH at 100°C for 180 min in a solid/liquid ratio of 1/20 allowed obtain a final extract with a concentration 452 mg carbohydrate/g of alga and 2.14 mg phlorotannins/g of alga, which represents a specific extraction yield of 89.6% for carbohydrates and 21.4% for phlorotannins. Subsequently, the use of macroporous resin XAD- 16N allowed separation of the 42% of phlorotannins from the extract. Finally, the enriched fraction with phlorotannins was lyophilized presenting a concentration of 14.2 mg phlorotannins/g lyophilized.
Este trabajo es financiado por una beca CONICYT para estudio de doctorado en Chile, el proyecto AKA-ERNC 0009 OPTIFU; y por el Centro Basal financiado por CONICYT CeBiB FB0001

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Silva, Gabriela da 1989-2016. "Aprendizado do etanol celulósico no Brasil = o caso do projeto Dedini Hidrólise Rápida (DHR)." [s.n.], 2013. http://repositorio.unicamp.br/jspui/handle/REPOSIP/287462.

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Orientador: André Tosi Furtado
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Geociências
Made available in DSpace on 2018-08-23T20:13:56Z (GMT). No. of bitstreams: 1 Silva_Gabrielada_M.pdf: 1679800 bytes, checksum: 464ab5544f5d77a03594a4b3d5e194fc (MD5) Previous issue date: 2013
Resumo: Devido à questão da dependência das energias de fontes fósseis, intensificou-se a corrida tecnológica para a produção de combustíveis alternativos renováveis no mundo inteiro. Assim, faz-se necessário que o Brasil entre nessa corrida para não perder essa janela de oportunidade e continuar no estado-da-arte da produção do bioetanol. Dentro dessa corrida tecnológica pelas tecnologias denominadas de segunda geração, a hidrólise se apresenta como a mais viável, no curto e médio prazo, para tornar-se o processo de produção dominante de etanol combustível para automóveis. O bioetanol combustível a partir da cana-de-açúcar é um produto importante para o Brasil e as políticas públicas estiveram presentes em sua promoção desde o início do século XX. Desde os anos 30, ele é comercializado como combustível no país, mas foi com o Proálcool e por meio de políticas públicas envolvidas com a criação de um mercado para esse biocombustível que esse combustível se consolidou na matriz energética. Este estudo tem como objetivo contextualizar as iniciativas que levaram ao desenvolvimento do etanol celulósico no Brasil. Para tanto foi realizado um estudo de caso do projeto Dedini Hidrólise Rápida (DHR). Analisou-se o aprendizado tecnológico e relacional da Dedini e de outras organizações do País diretamente e indiretamente envolvidas com o projeto. As conclusões da dissertação apontam que, através do projeto DHR, o Brasil teve um envolvimento muito maior com as tecnologias de etanol de segunda geração. Conclui-se que o uso do processo DHR como possibilidade de pré-tratamento do bagaço de cana-de-açúcar e o aprendizado tecnológico com o manuseio dessa matéria-prima, somado ao modelo de integração da segunda geração com a primeira, impulsionado por esse projeto, se configuram nos maiores aprendizados dessa iniciativa
Abstract: The issue of the dependence on fossil energy sources has intensified the technology race for the production of renewable alternative fuels worldwide. Thus, it is necessary that Brazil come into this race if the country don't want to miss this window of opportunity and continue in the state-of-the art of the production of bioethanol. Within the second-generation technological race, hydrolysis has the best conditions to become in the short and medium term the dominant production process of bioethanol. The sugar cane bio-ethanol fuel is an important product of the Brazilian economy and is present in its promotion public policies since the early twentieth century. Since the 1930, it is marketed as a fuel in the country, but it was with Proálcool and through public policies involved with the creation of a market for this biofuel that it became consolidated in the energy matrix. This dissertation aims to contextualize the initiatives that led to the development of cellulosic ethanol in Brazil. Therefore we conducted a case study of the Dedini Fast Hydrolysis project (DFH). The technological and relational learning of Dedini and other organizations of the country directly and indirectly involved with the Project was analysed. The conclusions of the dissertation show that Brazil had a much greater involvement with the second generation ethanol technology through the DFH project. This study concludes that the possible use of the DFH process as pre-treatment of sugarcane bagasse, and technological learning with handling this raw material, coupled with the integration model of the second generation with the first, driven by this project are the biggest learnings from this initiative
Mestrado
Politica Cientifica e Tecnologica
Mestra em Política Científica e Tecnológica

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Neiva, Duarte Miranda. "Bark biorefinery: deconstruction and chemical potential of Eucalyptus globulus and Picea abies barks." Doctoral thesis, ISA, 2020. http://hdl.handle.net/10400.5/21209.

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Doutoramento em Engenharia Florestal e dos Recursos Naturais / Instituto Superior de Agronomia. Universidade de Lisboa
Eucalyptus globulus and Picea abies barks are huge industrial residues with upgradable potential. This research thesis aims at further the knowledge on these barks envisaging production of biomaterials, building blocks, chemicals and fuels. Both industrial barks contained high wood and mineral extraneous contaminants, presenting higher extractives (10-20%) and ash (4-5%), but lower polysaccharides (52-61%) than their respective woods. E. globulus bark hemicelluloses (glucuronoxylan) and lignin (S/G=2.8, enriched in β-O-4’, 83% of all inter-unit linkages elucidated by 2D HSQC-NMR) were similar to those of wood, while P. abies bark differed substantially in hemicelluloses (pectin, higher arabinan, lower mannan) and lignin (γ-OH significant acetylation, presence of hydroxystilbenes glucosides as “nonconventional” true lignin monomers, adding to the canonical established monolignols precursors). The presence of glucosides in lignin was reported for the first time with positive ramifications regarding possible design and bioengineering of polymers with special attributes (hydrophilicity, bioactivity) Deconstruction pathways were tested considering the knowledge gathered. Bleached kraft pulp was produced from E. globulus bark due to previously determined appropriate physical and chemical characteristics. Hydrothermal pre-treatment tested decreased extractives content allowing for lower active alkali (15%) usage in pulping process (resulting in 40% yield) with subsequent bleached pulp and respective handsheets showing similar characteristics to those produced with E. globulus wood. Bark proved to be a possible fiber source feedstock for pulp and paper production. Crude extracts recovered with different solvents were analyzed for neutral monosaccharides and phenolic composition, antioxidant activity, antimicrobial and quorum-sensing potential. Polar extracts showed good or very good antioxidant activity. Gram positive and Candida strains had their growth highly impaired when exposed to n-hexane and ethanol extracts concentrations above 0.04 mg/mL. Extractive-free barks were autohydrolysed and the solid residues saccharified with commercial enzymes (Saczyme and Ultimase), resulting in xylooligosaccharides/arabinooligosaccharides enriched liquors from autohydrolysis, glucose rich streams from enzymatic saccharification and lignin enriched solid residues. This thesis evidences that these abundant industrial residues are interesting materials to be upgraded within a biorefinery concept of full biomass utilization with potential to generate several products and streams with different end-uses
N/A

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Guerra, Vera Lúcia Costa. "Optimização de pré-tratamento para a hidrólise selectiva da hemicelulose de bagaço de azeitona: estudo da bioconversão dos hidrolisados para a produção de xilitol." Master's thesis, ISA/UTL, 2011. http://hdl.handle.net/10400.5/3905.

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Mestrado em Engenharia Alimentar - Instituto Superior de Agronomia
The extracted olive pomace (EOP) is the waste of the olive-pomace oil extraction industry. Currently it is produced in large amounts throughout the entire Mediterranean basin, and there are no effective upgrade technologies for its valorization. As such, it is mainly used as an inexpensive energy source, either on site, or sold to other industries. As pomace oil extraction is carried out in large centralized facilities, this material is highly geographically concentrated, and already located on an industrial site. Furthermore, its significant polysaccharide content (above 45%) as quantified in this work, make it an interesting material for the biotechnological valorization within the biorefinery concept. The hemicellulosic content (that accounts for approximately 50% of all polysaccharides) is particularly relevant and its challenging valorization is studied in this work, by the development of an upgrading strategy targeted to the production of xylitol, a compound with potential applications in the food, pharmaceutical and cosmetic industries. For this, the dilute acid hydrolysis pre-treatment was used for the selective recovery of hemicelluloses. The effect of liquid/solid ratio (LSR) was initially studied, which enabled to define one of the lowest LSR described in literature (3) that enable to get highly concentrated pentose-rich hydrolysates and a low usage of process water. The dilute acid hydrolysis was further optimized by using the Doehlert experimental design to study the effects of time (0 to 180 min) and catalyst (H2SO4) concentration (0.5 to 3.5%) at 130 ºC. The combined severity factor (CS) was used to interpret the results and its limitations are highlighted, so that the use of empirical mathematical models was used instead to fine tune the operational conditions, that were established at 3.5% H2SO4 and 130 min (CS=2.64). Under the optimal conditions it was possible to obtain a hydrolysate containing more than 34 g/L of xylose, one of the highest reported in literature for non-concentrated hydrolysates. Furthermore, glucose was found in relative low amounts (similar to arabinose concentration), rendering this hydrolysate quite interesting for xylose bioconversion. The amounts of potential microbial inhibitors such as aliphatic acids (mainly acetic acid), furans (furfural and hydroxymethylfurfural) and phenolic compounds were high as compared to other hydrolysates. This is a consequence of the high content of extractives (of which soluble phenolic compounds) and the high degree of acetylation of the hemicelluloses and was dealt on the subsequent task, hydrolysate detoxification. The remaining solids have an increased glucan content that can be upgraded into bioethanol, within the integrated biorefinery concept. Hydrolysate detoxification was studied using physico-chemical treatments, specifically neutralization with alkaline agents (NaOH, Ca(OH)2, CaCO3), adsorption to activated charcoal, and evaporation. The best method found was the use of charcoal activated with XIV NaOH (patent pending from this work) that allowed to remove 100% of furfural, 97% hydroxymethylfurfural and 92% of phenolic compounds present in the hydrolysate. In order to access polyols production in BAE hydrolysate, six Debaryomyces hansenii yeast strains both from var. hansenii (CCMI 495, CCMI 470, CCMI 493 and 494) and var. fabryi (CCMI 496 and CCMI 941) were cultivated in chemically defined medium, with both glucose and xylose to mimic hydrolysate composition, in order to have some insight on their pentose metabolism. As expected, they have shown a quite different behavior, with strains belonging to var. fabryi showing a better performance than var. hansenii. Nevertheless, two strains were selected, one from each group, for further studies, The selected strains were CCMI 493 and CCMI 941 that displayed a lower biomass yield, a parameter chosen as indicator that they could potentially dissipate an higher Carbon flux into products. The bioconversion assays were carried out with both strains, in hydrolysate based media, but, conversely to CCMI 941, Debaryomyces hansenii CCMI 493 was not able to grow in these media. For CCMI 941 it was shown that the detoxification step is an absolute requirement, since without it, no growth, or xylitol production, were also observed. Simultaneously, the effect of hydrolysate concentration, aeration and supplementation was also studied through the addition to the hydrolysate of yeast extract, peptone, corn steep liquor and a solution of trace elements, vitamins and minerals (TEVM). The higher biomass and polyols productivity were obtained with the supplementation of low-cost salts (TEVM), what constitutes a significant advantage over other hydrolysates described in the literature.

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Hay, Yann-Olivier Marie. "La complexité des simples - Caractérisations chimique et biologique de combinaisons hydrolats-huiles essentielles et huiles essentielles-huiles essentielles pour l’objectivation d’effets conservateurs de produits phytothérapeutiques." Phd thesis, Toulouse, INPT, 2015. http://oatao.univ-toulouse.fr/15575/1/YHay.pdf.

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L’industrie parapharmaceutique de même que l’industrie cosmétique recherche des alternatives naturelles aux conservateurs synthétiques. Cet intérêt est lié à l’exigence du consommateur et à la volonté de développer des produits innovants éco-conçus. Compte tenu de leurs activités antioxydantes et antimicrobiennes, les huiles essentielles constituent des options intéressantes dont les coûts et impacts organoleptiques doivent cependant être considérés. Dans le cadre de cette thèse, les activités antioxydante et antimicrobienne de combinaisons huile essentielle-hydrolat et huile essentielle-huile essentielle de Lippia alba, Rosmarinus officinalis et Thymus vulgaris ont été évaluées afin d’objectiver leur potentiel de conservateur pour des produits phytothérapeutiques. Initialement, l’impact d’une méthode de distillation utilisant le macérât aqueux de la matière végétale comme source de vapeur a été évalué sur les propriétés physico-chimiques des hydrolats et huiles essentielles de Thymus vulgaris et Rosmarinus officinalis cultivées dans le sud de Bogotá en Colombie. Puis, les distillats et hydrolats ayant présenté une activité biologique significative ainsi que l’huile essentielle de Lippia alba ont été combinés deux à deux. Les activités antiradicalaire et microbicide ont été évaluées respectivement par ABTS et par les méthodes de microdilution et de diffusion en agar. Des résultats biologiques significatifs ont été obtenus pour les combinaisons huile essentielle-huile essentielle tout spécialement dans le cas de la combinaison des huiles essentielles de T. vulgaris et de L. alba avec une diminution de la CI50 de 2,9 (huile essentielle de Thym seule) à 1,4 µL/L ainsi que dans le cas spécifique de la combinaison hydrolat-huile essentielle de Thymus vulgaris avec une CI50 de 2,1 µL/L. De même, cette dernière combinaison a présenté un effet de synergie en diminuant la Concentration Minimale Bactéricide de l’huile essentielle de Thym de 0,4 à 0,1 µL/mL. Les différents résultats sont discutés ainsi que leurs impacts d’un point de vue industriel et thérapeutique.

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18

Merck, Madeline F. "Variability of Water Storage and Instream Temperature in Beaded Arctic Streams." DigitalCommons@USU, 2011. https://digitalcommons.usu.edu/etd/912.

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The purpose of this study is to investigate variation in water export and instream temperatures throughout the open water season in a beaded Arctic stream, consisting of small pools connected by shallow chutes. The goals are to better understand heat and mass movement through these systems, how this may impact chemical and biological processes, and the resulting shifts with changes in climate. This is accomplished by first examining the extent and variability of water storage and export through qualitative analysis of observational data. Further, heat fate and transport is examined through development of an instream temperature model. The model formulation, a simple approach to model calibration and validation, and information regarding residence and characteristic times of different pool layers are presented. Using temperatures measured at high spatial resolution within the pools and surrounding bed sediments as well as other supporting data (e.g., instream flow, specific conductivity, weather data, and bathymetry), various types of storage within the pools, banks, and marshy areas within the riparian zone, including subsurface flow paths that connect the pools, were found. Additionally, data illustrated that some pools will stay stratified during higher flow periods under certain weather conditions. Through modeling efforts, the dominant heat sources were found to vary between stratified layers. It was also found that potential increases in thaw depths surrounding these pools can shift stratification and mixing patterns. These shifts can further influence mass export dynamics and instream water quality. Given the amount and different types of storage within these systems and the influence of stratification patterns on the residence times in the pools, Imnavait Basin and similar beaded Arctic watersheds will likely experience delayed export of nutrients that are limiting in most Arctic systems.

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Fugita, Tatiane Passa Lozano. "Desempenho de leveduras que metabolizam xilose para produção de etanol em hidrolisado hemicelulósico de bagaço de cana /." Jaboticabal : [s.n.], 2010. http://hdl.handle.net/11449/94895.

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Resumo: Objetivou-se avaliar a produção de etanol por leveduras assimiladoras de xilose, usando como substrato hidrolisado hemicelulósico de bagaço de cana. Foram realizados dois experimentos, em delineamento inteiramente casualizado, com esquema fatorial 2x3, com 4 repetições. O primeiro fator analisado foram dois mostos (mosto proveniente do hidrolisado hemicelulósico do bagaço de cana e mosto sintético), e o segundo três estirpes de levedura (J10, J19.1 e CG). No primeiro experimento empregou-se o hidrolisado original, obtido após hidrólise da fração hemicelulósica do bagaço de cana-de-açúcar e no segundo utilizou-se o hidrolisado concentrado, com maiores concentrações de açúcares. Foram analisadas o consumo dos açúcares, a produção de etanol e de ácido acético e a viabilidade celular e o brotamento das leveduras. Observou-se que as três cepas estudadas produziram etanol a partir da xilose e glicose, sendo que a J10 apresentou maior produção. Também houve produção de ácido acético nas fermentações em que o hidrolisado foi empregado como mosto. A viabilidade celular e o índice de brotamento das leveduras não foram influenciados pelos tratamentos
Abstract: The objective of this research was evaluate the ethanol production by xylose-fermenting yeasts, using as substrate hemicellulosic hydrolysate from sugarcane bagasse. Two experiments were conducted, in a 2 x 3 factorial as a completely randomized design. Treatments corresponded to the musts (sugarcane bagasse hemicellulosic hydrolysate and sintetic must) and three yeasts strains (CG, J10 and J19.1). Analyses were performed in four replications. In the first experiment, original hydrolysate, obtained after hydrolyse of the hemicellulosic fraction from sugarcane bagasse and in the second, the concentrate hydrolysate (with high sugars concentration) were used. Sugars consumption, ethanol and acetic acid production and yeast viability and buds rate. Results shown that the three yeasts strains produce ethanol from xylose metabolism, and J10 strain presents high ethanol yield. Also, there was acid acetic production during fermentations process when hydrolysate was used as a must. Cellular viability and bud rates were not affected by treatments
Orientador: Márcia Justino Rossini Mutton
Coorientador: Maria das Graças de Almeida Felipe
Banca: Adilson Roberto Gonçalves
Banca: Marco Antonio de Castro e Souza
Mestre

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20

Elfving, Erik. "Hydrolys av primärslam för förbättrande av biologisk fosforreduktion vid behandling av hushållsavloppsvatten [Hydrolysis of primary sludge for enhancement of biological phosphorus removal in household wastewater]." Thesis, Linköping University, Department of Water and Environmental Studies, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-3997.

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Hammarby Sjöstad is a new district of southern Stockholm built with focus on reduced environmental impact by recirculation of materials and sustainability. The environmental goals aim to cut the water consumption by half and a separate storm water treatment. Thus, the wastewater will be more concentrated and will originate from the households only. The Sjöstad project includes the idea of a local treatment plant for the household wastewater. To evaluate this possibility, Sjöstadsverket, an experimental treatment plant was constructed. New wastewater treatment processes are tested and evaluated and compared to conventional methods including both aerobic and anaerobic treatment processes.

One of the aerobic treatment processes includes enhanced biological phosphorus removal (EBPR or Bio-P) as the method for the removal of phosphorus. In biological phosphorus removal the wastewater is alternately being exposed to anaerobic and aerobic conditions, which favours a certain bacteria, which can accumulate more phosphorus than is required for their growth. For this phosphorus accumulation the bacteria need volatile fatty acids (VFA) to cover their energy demand, but normally there is a shortage in VFA in the incoming wastewater.

The main purpose of this master thesis work has been to create the best possible conditions in order to produce VFA by hydrolysis and fermentation of primary sludge. In this way the organic material in the incoming wastewater can be used in biological phosphorus removal.

The sludge temperature, total solids (TS) and retention time are regarded as important parameters for a successful biological phosphorus removal and a laboratory study was set up to investigate these conditions for the wastewater at the Hammarby Sjöstad experimental plant. These laboratory-scale hydrolysis experiments showed that high temperature and high TS favours VFA-production. The results have also shown that four to five days retention time is suitable at a process temperature higher than 23°C, but also that the retention time likely should be extended at lower temperatures.

In a full-scale process experiment, primary sludge was pumped from a primary clarifier to a hydrolysis tank and then back to the primary clarifier. The hydrolysis gave rise to increased VFA-production when TS was increased. A temperature difference between the primary sludge and the hydrolysis sludge of 3°C was observed. The reason behind the difference has not been determined, but is considered important, since the temperature affects the VFA-production. Further on, analyses with gas chromatograph (GC) have shown that acetate has been the most frequently occurring VFA, although significant levels of other VFA, such as propionate, has also been detected.

Phosphorus release tests in laboratory-scale, where phosphorus was released during an anaerobic phase and taken up during an aerobic phase, proved that biological phosphorus removal occurred at the full-scale experimental train.

The full-scale hydrolysis experiment has shown that the VFA contribution by the hydrolysis tank to the biological phosphorus removal was low. The main reason is that the sludge-flow through the hydrolysis tank has been insignificant compared to the incoming wastewater flow. The problem is most likely connected to the incoming wastewater characteristics, since the low share of suspended solids (SS) entailed that not enough organic material in the primary clarifier settled.

I figur 57 på sidan 76 stämmer inte trendlinjernas ekvationer i den tryckta versionen. Dessa är nu korrigerade i den elektroniska versionen, så att rätt ekvationer finns i den aktuella figuren.

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Fugita, Tatiane Passa Lozano [UNESP]. "Desempenho de leveduras que metabolizam xilose para produção de etanol em hidrolisado hemicelulósico de bagaço de cana." Universidade Estadual Paulista (UNESP), 2010. http://hdl.handle.net/11449/94895.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Objetivou-se avaliar a produção de etanol por leveduras assimiladoras de xilose, usando como substrato hidrolisado hemicelulósico de bagaço de cana. Foram realizados dois experimentos, em delineamento inteiramente casualizado, com esquema fatorial 2x3, com 4 repetições. O primeiro fator analisado foram dois mostos (mosto proveniente do hidrolisado hemicelulósico do bagaço de cana e mosto sintético), e o segundo três estirpes de levedura (J10, J19.1 e CG). No primeiro experimento empregou-se o hidrolisado original, obtido após hidrólise da fração hemicelulósica do bagaço de cana-de-açúcar e no segundo utilizou-se o hidrolisado concentrado, com maiores concentrações de açúcares. Foram analisadas o consumo dos açúcares, a produção de etanol e de ácido acético e a viabilidade celular e o brotamento das leveduras. Observou-se que as três cepas estudadas produziram etanol a partir da xilose e glicose, sendo que a J10 apresentou maior produção. Também houve produção de ácido acético nas fermentações em que o hidrolisado foi empregado como mosto. A viabilidade celular e o índice de brotamento das leveduras não foram influenciados pelos tratamentos
The objective of this research was evaluate the ethanol production by xylose-fermenting yeasts, using as substrate hemicellulosic hydrolysate from sugarcane bagasse. Two experiments were conducted, in a 2 x 3 factorial as a completely randomized design. Treatments corresponded to the musts (sugarcane bagasse hemicellulosic hydrolysate and sintetic must) and three yeasts strains (CG, J10 and J19.1). Analyses were performed in four replications. In the first experiment, original hydrolysate, obtained after hydrolyse of the hemicellulosic fraction from sugarcane bagasse and in the second, the concentrate hydrolysate (with high sugars concentration) were used. Sugars consumption, ethanol and acetic acid production and yeast viability and buds rate. Results shown that the three yeasts strains produce ethanol from xylose metabolism, and J10 strain presents high ethanol yield. Also, there was acid acetic production during fermentations process when hydrolysate was used as a must. Cellular viability and bud rates were not affected by treatments

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22

Landmér, Alice. "Sambandet mellan cellulosakedjans polymerisationsgrad och styrkan i nanofibrillerad cellulosafilm." Thesis, KTH, Skolan för kemivetenskap (CHE), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-179642.

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Studiens syfte var att undersöka vilken effekt cellulosakedjornas polymerisationsgrad (D.P.) har på styrkan i nanofibrillerad cellulosafilm (NFC-film). Detta är av intresse på grund av tidigare studier som indikerar att både filmstyrkan och töjningen hos NFC-film ökar med ett ökande D.P. hos materialet som NFC produceras ifrån, samt att starkare NFC-filmer önskas tas fram. En ökad styrka och töjning hos NFC-filmer är viktigt för att kunna utöka användningsområdet för filmen, t.ex. inom applikationer som beständiga displayers eller till förpackningar. I denna studie framställdes NFC system genom att först hydrolysera ett bomullsmaterial med högt D.P. till olika grader. Bomullen karboxymetylerades därefter för att sedan homogeniseras till NFC. Avslutningsvis, framställdes filmer baserade på de olika NFC systemen, vars mekaniska egenskaper undersöktes för att utvärdera effekten av D.P. Dragtesten som utfördes på filmerna visade på att dragindexet (TSI) var det som påverkades mest markant av D.P. variationen. Det tycktes finnas en kritisk gräns för D.P. ≤ 2600, under vilken styrkan sjunker medan en icke nämnvärd förändring av styrkan sker över gränsen.
The purpose of this study was to investigate the effect of the degree of polymerization (D.P.) of cellulose on the strength of nanofibrillated cellulose film (NFC-film). The interest to investigate this effect is based on earlier studies, which have shown results that indicate on an increasing strength and strain for the films with an increasing D.P. of the material from which the NFC is produced. The desire to produce stronger NFC-films is also a reason for the study. Both an increased strength and strain are desired in the NFC-films, because it would expand the possible use of the films, for example as displays and in packaging applications. In this study, the NFC systems were prepared by first hydrolyzing the cotton linters, which had a high D.P., to different degrees. Then the cotton systems were carboxymetylated and homogenized. Finally, the films were prepared from the different NFC systems, whose mechanical properties were studied to evaluate the effect of D.P. The tensile tests that were performed on the films showed that the tensile strength index (TSI) was most significantly affected by the D.P. variation. There seemed to be a critical limit for D.P. at ≤ 2600, below which the strength decreases while a non-significant change in strength occurred above.

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23

Hauck, Matthieu. "Optimisation de l'architecture et de la commande de la chaîne électrique d'une hydrolienne fluviale : conception et réalisation." Phd thesis, Université de Grenoble, 2011. http://tel.archives-ouvertes.fr/tel-00732840.

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Le but de cette thèse est le développement et l'optimisation de la chaine électrique d'une hydrolienne fluviale. L'approche est d'abord traitée en simulation pour ensuite finir par la conception et la mise au point d'un prototype. La partie simulation concerne la modélisation des ensembles turbines, génératrices et électronique de puissance mais aussi le développement des diverses lois de commandes. Ces commandes peuvent intervenir à différents niveaux du contrôle jusqu'à la supervision complète du système, permettant de gérer des défauts, des algorithmes de MPPT (extraction maximale de puissance), des synchronisations entre colonne, ... Le prototype d'hydrolienne fluviale sera ensuite présenté, de la mise au point des parties mécaniques jusqu'aux résultats expérimentaux. Les travaux nombreux autour de ce prototype ont permis d'obtenir des résultats satisfaisants et encourageants qui corroborent la théorie.

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24

Martins, Luiza Helena da Silva 1984. "Avaliação de diferentes pré-tratamentos do bagaço de cana de açúcar considerando altas cargas de sólidos." [s.n.], 2015. http://repositorio.unicamp.br/jspui/handle/REPOSIP/266025.

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Orientador: Aline Carvalho da Costa
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química
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Resumo: A indústria sucroalcooleira é uma atividade de grande importância para o Brasil, e tem o bagaço de cana-de-açúcar como o principal subproduto, o qual pode ser utilizado para a produção de etanol de 2ª geração. Nesse contexto, são cada vez maiores os estudos relacionados com as tecnologias de pré-tratamento, etapa fundamental para a eficiente produção deste tipo de combustível. Entretanto, o custo de reagentes e gastos com tratamento de águas residuais ainda é um obstáculo para este tipo de tecnologia. Assim, o presente trabalho teve como objetivo estudar 3 tipos de pré-tratamentos do bagaço de cana-de-açúcar: H2SO4 diluído, Peróxido de hidrogênio alcalino (PHA) e hipoclorito-hidrogênio peróxido (Ox-B), com a utilização de elevadas cargas de sólidos, tanto na etapa de pré-tratamento quanto na de hidrólise enzimática, visando a redução do uso de reagente e do consumo de água. Para todos os pré-tratamentos foram realizados planejamentos experimentais de 3 níveis (3²). O material pré-tratado com H2SO4 diluído, PHA e Ox-B foi submetido a hidrólise enzimática com 10% (m/v) de sólidos, com carga enzimática de 15 FPU/g e 25 CBU/g de bagaço. Para a melhor condição do pré-tratamento realizado com PHA foi estudada a substituição do uso do NaOH por KOH e Mg(OH)2 para ajuste do pH em 11,5. Um estudo do aumento da carga de sólidos na hidrólise enzimática também foi realizado (batelada simples e alimentada) para os materiais pré-tratados com os três reagentes estudados, sendo os hidrolisados submetidos a fermentação com S. cerevisiae. As maiores conversões obtidas na hidrólise enzimática para carga de sólidos de 10% (m/v) foram: 60,80% para o H2SO4, 76,00% para o PHA, 66,9% para o Ox-B. O aumento da carga de sólidos na hidrólise enzimática teve efeito negativo na conversão. O material pré-tratado com PHA foi o que mostrou melhores resultados tanto para a hidrólise enzimática como para a fermentação, que atingiu rendimento máximo de 84,48% de etanol a 34ºC a 20% (m/v) de sólidos no pré-tratamento e 10% (m/v) de sólidos na hidrólise enzimática
Abstract: The sugar industry is a very important activity for Brazil, and has the bagasse sugarcane as the main by-product, which can be used for the 2nd generation ethanol production. In this context, there are increasing studies related to pretreatment technologies, essential step for efficient production of this type of fuel. However, the cost of reagents and treatment costs of waste waters are still an obstacle for this type of technology. Thus, this study aimed to evaluate three types of pretreatments of sugarcane bagasse: diluted H2SO4 , alkaline hydrogen peroxide (APH) and hypochlorite-hydrogen peroxide (Ox-B), using high solid loadings, both in the pretreatment and the enzymatic hydrolysis step in order to reduce reagent usage and consumption of water. For all pre-treatments were carried out experimental design of three levels (3²). The pretreated material with dilute H2SO4, APH and Ox-B was subjected to enzymatic hydrolysis with 10% (w/v) solids, with enzyme load of 15 FPU/g and 25 CBU/g of residue. To the best condition pretreatment was performed with PHA studied substitution of KOH for the NaOH and Mg(OH)2 for pH adjustment to 11.5. A study of increased solids loading in the enzymatic hydrolysis was also performed (simple and fed batch) for pretreated material with the three reagents studied, and the hydrolysates subjected to fermentation with S. cerevisiae. The highest conversions obtained in the enzymatic hydrolysis to solids loading of 10% (w/v) were 60.80% for the H2SO4 76.00% for the APH, 66.9% for Ox-B. The increased of solids loading on enzymatic hydrolysis had a negative effect on conversion. The pre-treated material showed that the PHA was the best results for both the enzymatic hydrolysis and also for fermentation, reaching a maximum yield of 84.48% ethanol at 34 ° C with 20% (w/v) solids in the pre-treatment and 10% (w/v) solids in the enzymatic hydrolysis
Doutorado
Desenvolvimento de Processos Químicos
Doutora em Engenharia Quimica

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SILVA, Frederico Costa e. "Síntese, Caracterização E Estudo De Propriedades Magnéticas De Ferritas Mistas." Universidade Federal de Goiás, 2011. http://repositorio.bc.ufg.br/tede/handle/tde/1042.

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The nanoscience and nanotechnology exhibited an outstanding development, which have been caused by the unusual properties featured by materials in the nanometric regime. Because of this, many magnetic materials with sizes smaller than before have been studied; among these materials, the ferrites have been extensively researched in new applications as drug carriers and ferrofluid components. In this work cobalt magnesium mixed ferrites, Co1-xMgxFe2O4 where 0 ≤ x ≤ 0.6, were synthesized by the forced hydrolysis method, which involves the hydrolysis of precursor salts mixed in a organic medium under mild heating. The structural characterization of the obtained materials was done by X-Ray Diffraction (DRX) and Transmission Electron Microscopy (MET); beyond these, the materials were characterized by Infrared Spectroscopy (FTIR), Thermogravimetry (TG) and Differential Thermal Analysis (DTA). The magnetic characterization was done in a Vibrating Sample Magnetometer (VSM), in applied fields varying from -2 to +2 Tesla and at 273, 323 and 373 K temperatures, and in a Physical Properties Measuring System (PPMS) operating in a temperature range of 4 to 300 K. The synthesized materials featured the characteristic spinel structure from ferrites, low crystallinity and average crystallite diameter below 5 nm. The presence of organic residues from the synthetic step was detected and quantified in the samples; beyond this, an increase of crystallinity of the material was observed when this is thermally treated. Using the room temperature and above room temperature magnetization curves of the samples, the superparamagnetic behavior was detected and confirmed. The saturation magnetization of the samples at room temperature were 260.29, 237.42, 198,27, 191.25 e 161.49 emu/cm3 to the samples with x =0, 0.2, 0.4, 0.5 e 0.6, respectively; then, the substitution of Co2+ with Mg2+ caused the decrease of saturation magnetization of the synthesized samples. The samples Blocking Temperature (TB) were obtained of the Zero Field Cooling (ZFC) and Field Cooling (FC) curves, and, with those values, the Effective Anisotropy Constants (Kef) of each sample were calculated; the obtained values were 196 K and 1.41 x 107 ergs/cm3 to the x = 0 sample; 178 K and 1.28 x 107 ergs/cm3 to the x = 0.2 sample; 172 K and vi 1.24 x 107 ergs/cm3 to the x = 0.4 sample; 172 K and 1.24 x 107 ergs/cm3 to the x = 0.5 sample and 146 K and 1.05 x 107 ergs/cm3 to the x = 0.6 sample. The trend featured by the obtained TB and Kef values was directly associated with the Ms trend. A comparison of the Anisotropy Constants between the x = 0 sample, a bulk and a 8.5 nm diameter cobalt ferrite were also done; among these, the x = 0 sample featured a higher value of Kef, therefore, the x = 0 sample anisotropy energy seems to be composed by superficial and interparticle magnetic effects contributions besides the magnetocrystalline energy contribution.
A nanociência e a nanotecnologia têm apresentado um grande crescimento devido às novas propriedades exibidas por materiais em regime nanométrico. Por isso, materiais magnéticos com tamanhos cada vez menores têm sido estudados; dentre estes materiais, as ferritas têm sido extensivamente pesquisadas em novas aplicações como carreadoras de fármacos e composição de ferrofluidos. Neste trabalho ferritas mistas de cobalto e magnésio, Co1-xMgxFe2O4 onde 0 ≤ x ≤ 0,6, foram sintetizadas através do método de hidrólise forçada, que envolve a hidrólise de uma mistura de sais precursores em um meio orgânico a médias temperaturas. A caracterização estrutural dos materiais obtidos foi realizada por Difração de Raios-X (DRX) e Microscopia Eletrônica de Transmissão (MET); ainda foram realizadas análises de Espectroscopia de Infravermelho (FTIR), de Termogravimetria (TG) e de Análise Térmica Diferencial (DTA). A caracterização magnética destes materiais foi realizada em um Magnetômetro de Amostra Vibrante (VSM), com campos aplicados de -2 a +2 Tesla e temperaturas de 273, 323 e 373 K, e em um Sistema de Medidas de Propriedades Físicas (PPMS), em temperaturas de 4 a 300 K. Os materiais sintetizados apresentaram estrutura de espinélio com baixa cristalinidade e diâmetros médios de cristalito menores que 5 nm. A presença de resíduos orgânicos provenientes da etapa de síntese foi detectada e quantificada nas amostras; além disso, observou-se um aumento da cristalinidade das mesmas quando tratadas termicamente. Através das curvas de magnetização a temperatura ambiente das amostras, observou-se que as mesmas apresentavam superparamagnetismo. Os valores de Magnetização de Saturação (Ms) a temperatura ambiente foram de 260,29, 237,42, 198,27, 191,25 e 161,49 emu/cm3 para as amostras com x =0, 0,2, 0,4, 0,5 e 0,6, respectivamente; logo a substituição de íons Co2+ por Mg2+ causa a diminuição da magnetização de saturação das amostras. Através de curvas de Zero Field Cooling (ZFC) e Field Cooling (FC) os valores das Temperaturas de Bloqueio (TB) e, consequentemente, das Constantes de Anisotropia Efetiva (Kef) das amostras foram obtidos; estes valores foram de, respectivamente, 196 K e 1,41 x 107 ergs/cm3 para a amostra com x = 0; 178 K e 1,28 x 107 ergs/cm3 iv para a amostra com x = 0,2; 172 K e 1,24 x 107 ergs/cm3 para a amostra com x = 0,4; 172 K e 1,24 x 107 ergs/cm3 para a amostra com x = 0,5 e 146 K e 1,05 x 107 ergs/cm3 para a amostra com x = 0,6. Todos os valores de TB e de Kef obtidos decresceram frente ao aumento da concentração de Mg2+, o que foi explicado em termos da diminuição de Ms ao longo da série de amostras. Uma comparação entre os valores de constante de anisotropia foi feita para a amostra x = 0, a ferrita de cobalto no estado bulk e nanopartículas de ferrita de cobalto com 8,5 nm de diâmetro; visto que o valor desta constante é consideravelmente maior para a amostra x = 0 conjecturou-se que as contribuições de superfície e de interações magnéticas entre partículas à energia de anisotropia sejam maiores para a amostra x= 0 do que para as nanopartículas de CoFe2O4 usadas na comparação.

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Toll, Nils. "Studie om åldring av färgfilm med FTIR-ATR och SEM." Thesis, KTH, Skolan för kemi, bioteknologi och hälsa (CBH), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-231529.

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FTIR-ATR och SEM användes för att analysera olika typer av ytbehandlingar då de utsatts för accelererad åldring. Ytbehandlingarna som analyserats var olika typer av akrylatemulsioner, en UV-härdande produkt, en syrahärdande produkt och en vattenburen UV-härdande produkt. Två olika metoder för att kvantifiera degraderingen av färgfilmerna undersöktes, POI-metoden och karbonylindex. Båda dessa metoder går ut på att jämföra antingen arean eller höjden av två FTIR toppar med varandra. Studien avslutades med en topografisk analys av proverna mha SEM. FTIR-ATR visade sig vara ett effektivt instrument för att undersöka degraderingen av färgfilmer. POI-metoden användes för att kvantifiera 9 av 12 ytbehandlingar och ranka Serwin Williams produkter från bäst till sämst utomhusbeständighet. De ytbehandlingar som uppvisade störst kemiska förändringar hade alla aromat komponenter. Dessa absorberar UV-ljus och påverkas därför extra mycket av fotooxidation. De ytbehandlingar som avvek från de resterande var klarlacker och den vattenburna UV-härdande färgen. Klarlackerna visade minimala kemiska förändringar och den UV-härdande produkten minskade i POI, olikt resterande ytbehandlingar. Karbonylindex visade sig inte vara en effektiv metod för att bedöma degradering av färgfilmerna då värdet ökade för två av produkterna som testades och minskade för de två andra. Karbonyltoppen vid 1720cm-1 kan dock analyseras utan att beräkna karbonylindex då den kan ge mycket intressant information om den förändrande karbonylkompositionen. Testerna av topografin med SEM visade mycket detaljerade bilder av degradering processen som föll i linje med resultaten från FTIR analysen.
FTIR-ATR and SEM were used to analyze different types of coatings exposed to accelerated ageing. The coatings valuated in this study were different types waterborne acrylic emulsions, a UV-curing coating, an acid curing coating and a waterborne UV-curing coating. Two different ways to quantify the degradation with FTIR-ATR were explored, the POI method and carbonyl index. Both methods are based on comparing the height/area of specific FTIR peaks with one another. The study was concluded with a topographic analysis with SEM for some of the samples. Results from this study shows that FTIR-ATR is an effective tool to explore the degradation of different types of coatings. The POI method was successfully used to quantify the degradation concerning 9 of the 12 studied coatings and ranking the coatings from best to worst. Coatings with aromatic components mounted the biggest chemical changes thanks to their instability when exposed to UV-radiation. Coatings that deviated from the rest were acrylic clearcoats and the waterborne UV-curing coating. Clearcoats mounted minimal chemical changes in the FTIR-ATR, and the waterborne UV-curing coating was degraded in a way that it’s POI value decreased during ageing, unlike all other coatings tested. Carbonyl index proved insufficient for quantifying degradation in this study, although the carbonyl peak around 1720 cm-1 can be analyzed manually to attain valuable information about the changing carbonyl composition. Topographical analysis with SEM gave valuable information showing detailed pictures of the degradation which all were in line with the results from the FTIR spectrums.

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Delgado, Paula Aparecida. "Desenvolvimento de processo enzimatico para redução de sedimentos em extratos de cafe soluvel." [s.n.], 2008. http://repositorio.unicamp.br/jspui/handle/REPOSIP/266230.

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Orientador: Telma Teixeira Franco
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica
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Resumo: Polissacarídeos são os principais constituintes do café verde, torrado e solúvel, sendo principalmente galactomananos e arabinogalactanos. Um aspecto importante em relação a estes polissacarídeos é a insolubilidade, umas das possíveis razões para a formação de sedimentos na produção de café solúvel, reduzindo o rendimento do processo. Em face disto, o objetivo deste trabalho foi investigar a redução de sedimentos em extrato de café pela ação de enzimas. Diversas preparações comerciais de pectinases foram selecionadas e suas diferentes atividades determinadas. Rohapect B1L apresentou a maior atividade de mananase. Adicionalmente, a maioria das preparações estudadas apresentou outras atividades enzimáticas, tais como mananase, endoglucanase, xilanase, além da atividade atestada pelos fabricantes. Frações solúveis e insolúveis do extrato de café e sedimento foram preparadas e suas composições determinadas. Os principais componentes do extrato de café e sua fração insolúvel foram carboidratos e proteínas, enquanto que a fração insolúvel do sedimento apresentou também uma fração significativa de lignina. Pela análise dos carboidratos, galactose, arabinose e manose foram os principais monossacarídeos obtidos após hidrólise ácida, confirmando a presença de galactomananos e arabinogalactanos. Galactomanano com baixo grau de ramificação foi o principal polissacarídeo encontrado nas frações insolúveis. Biopectinase CCM, Rohapect B1L, Pectinase 444L e Galactomananase ACH foram as preparações enzimáticas mais eficientes na redução de sedimento do extrato de café, sendo Rohapect B1L e Galactomananase ACH as mais viáveis, cujas concentrações ótimas foram 0,3 e 0,1 mgproteína/gsubstrato, respectivamente. A massa molecular média dos components do extrato de café foi 18 kDa, a qual decresceu 6,6% após hidrólise com Rohapect B1L. O principal açúcar liberado por esta enzima foi a manose, sugerindo sua ação sobre as cadeias de mananos do café, devido a alta atividade de mananase. Os extratos hidrolisados pelas preparações enzimáticas Rohapect B1L e Galactomananase ACH foram avaliados sensorialmente. Provadores treinados verificaram uma pequena a moderada diferença entre os extratos hidrolisados e o controle; entretanto, o tratamento enzimático não alterou a aceitação das amostras por parte dos consumidores. Os resultados mostraram boas perspectivas para a utilização de enzimas no processo de redução de sedimentos em extratos de café solúvel
Abstract: Polysaccharides are the main components of green, roasted and soluble coffee, and they are mainly galactomannans and arabinogalactans. An important aspect about these polysaccharides is the insolubility, possibly one of the reasons for the sediments formation in the production of instant coffee, reducing the yield of the process. Thus, the aim of this work was to investigate the reduction of sediments in coffee extract by the action of enzymes. Several commercial preparations of pectinases were selected and their different activities were determined. Rohapect B1L presented the highest mannanase activity. Most of the commercial pectinases assayed presented other enzyme activities, like mannanase, endoglucanase, xylanase, besides the activity stated by the manufacturers. Soluble and insoluble fractions from coffee extract and sediment were prepared and their chemical composition determined. The main components of extract and its insoluble fraction were carbohydrates and proteins, while the insoluble fraction of sediment presented also a significant amount of lignin. Based on the carbohydrate analysis, galactose, arabinose and mannose were the main monosaccharides obtained after acid hydrolysis, confirming the presence of galactomannans and arabinogalactans. Galactomannan with low degree of branching was found to be the main polysaccharide of the insoluble fractions. Biopectinase CCM, Rohapect B1L, Pectinase 444L and Galactomannanase ACH were found to be themost effective enzyme preparations on the sediment reduction of coffee extract, being Rohapect B1L and Galactomannanase ACH the more viable ones, which optimumconcentrations were 0.3 and 0.1 mgprotein/gsubstrate, respectively. The average molecular weight of the coffee extract components was 18 kDa, which decreased 6.6% after hydrolysis with Rohapect B1L. The main sugar released by this enzyme preparation was mannose, suggesting its action on coffee mannans, due to the high activity of mannanase. The extracts hydrolyzed by Rohapect B1L and Galactomannanase ACH were evaluated for the sensory quality. Trained panelists indicated a small to moderate difference between the hydrolyzed extracts and the control; however, the enzymatic treatment did not alter the consumers¿ acceptance of the coffee extract. The results showed good perspectives for the use of enzymes in reducing sediments in coffee extracts
Doutorado
Desenvolvimento de Processos Químicos
Doutor em Engenharia Química

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Sforcini, Mariana Paula Rossi. "Silagem de milho, cana-de-açúcar in natura e hidrolisada, para vacas em lactação /." Jaboticabal : [s.n.], 2009. http://hdl.handle.net/11449/96580.

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Orientador: Mauro Dal Secco de Oliveira
Banca: André de Faria Pedroso
Banca: Paulo de Figueiredo Vieira
Resumo: Objetivou-se avaliar a cana-de-açúcar hidrolisada (CH) com cal virgem como único volumoso na dieta de vacas em lactação sobre o consumo de nutrientes, produção e composição do leite, e análise parcial de custos. Os tratamentos foram cana-de-açúcar picada in natura (CIN), CH com 0,5% de cal virgem armazenada por 48 horas (CH48), CH com 0,5% de cal virgem armazenada por 72 horas (CH72) e silagem de milho (SM), juntamente com o concentrado. Utilizaram-se oito vacas da raça holandesa, pós-pico de lactação, delineadas em dois quadrados latino 4x4, com períodos de 19 dias. O consumo de matéria seca (CMS) foi em média 17,42; 10,90; 10,49 e 10,12 kg para o tratamento com SM, CIN, CH48 e CH72 respectivamente (P<0,05). O consumo de nutrientes em kg/dia e em porcentagem do peso corporal, com exceção do consumo de fibra em detergente ácido, foi superior (P<0,05) para o tratamento SM em relação aos demais tratamentos. Para os tratamentos contendo cana-deaçúcar foi verificado que o consumo de fibra em detergente neutro foi menor para CH72 em relação à CIN, e ambos semelhantes à CH48. A produção de leite foi em média 13,29; 9,55; 10,45 e 11,10 kg/dia para o tratamento com SM, CIN, CH48 e CH72 respectivamente (P<0,05). Quanto à composição do leite verificou-se que independente do tratamento, permaneceu dentro dos padrões exigidos. Vacas alimentadas com silagem de milho juntamente com o concentrado produziram mais leite que vacas alimentadas com a CH com 48 e 72 horas mais o concentrado, porém a alimentação de vacas leiteiras com CH proporcionou redução no custo do quilograma de leite produzido e melhor margem bruta.
Abstract: The objective was to evaluate the sugar cane hydrolyzed (SCH) with virgin lime as the only roughage in the diet of dairy cows on the consumption of nutrients, production, milk composition and partial analysis of costs. The treatments were cane in nature (CIN), sugar cane hydrolyzed with 0.5% of lime virgin and 48 hours of storage (SC48), sugar cane hydrolyzed with 0.5% of lime virgin and 72 hours of storage (SCH72), and corn silage (CS), together with the concentrate. Eight Holstein cows, post-peak lactation, were used outlined in Latin square 4x4, with periods of 19 days. The dry matter intake was on averaged 17.42, 10.90, 10.49 and 10.12 kg for the treatment with CS, CIN, SCH48 and SCH72 respectively (P<0.05). The consumption of nutrients in kg/day and percentage of body weight, with the exception of consumption of acid detergent fiber, it was greater (P <0.05) for animals fed with CS than the animals fed with other treatments. For treatments containing sugar cane was verified that the neutral detergent fiber consumption was higher for SCH72 on CIN, both similar to SCH48. Milk production was on average 13.29, 9.55, 10.45 and 11.10 kg/day for the treatment with CS, CIN, SCH48 and SCH72 respectively (P<0.05). About milk composition it was verified that independent of treatment, remained within the required standards. Cows fed with corn silage together with the concentrate produced more milk than cows fed with SCH with 48 and 72 hours more the concentrate, but the feeding of dairy cows with sugar cane hydrolyzed has reduced the cost of kilograms of milk produced and with better gross margin.
Mestre

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Sforcini, Mariana Paula Rossi [UNESP]. "Silagem de milho, cana-de-açúcar in natura e hidrolisada, para vacas em lactação." Universidade Estadual Paulista (UNESP), 2009. http://hdl.handle.net/11449/96580.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Objetivou-se avaliar a cana-de-açúcar hidrolisada (CH) com cal virgem como único volumoso na dieta de vacas em lactação sobre o consumo de nutrientes, produção e composição do leite, e análise parcial de custos. Os tratamentos foram cana-de-açúcar picada in natura (CIN), CH com 0,5% de cal virgem armazenada por 48 horas (CH48), CH com 0,5% de cal virgem armazenada por 72 horas (CH72) e silagem de milho (SM), juntamente com o concentrado. Utilizaram-se oito vacas da raça holandesa, pós-pico de lactação, delineadas em dois quadrados latino 4x4, com períodos de 19 dias. O consumo de matéria seca (CMS) foi em média 17,42; 10,90; 10,49 e 10,12 kg para o tratamento com SM, CIN, CH48 e CH72 respectivamente (P<0,05). O consumo de nutrientes em kg/dia e em porcentagem do peso corporal, com exceção do consumo de fibra em detergente ácido, foi superior (P<0,05) para o tratamento SM em relação aos demais tratamentos. Para os tratamentos contendo cana-deaçúcar foi verificado que o consumo de fibra em detergente neutro foi menor para CH72 em relação à CIN, e ambos semelhantes à CH48. A produção de leite foi em média 13,29; 9,55; 10,45 e 11,10 kg/dia para o tratamento com SM, CIN, CH48 e CH72 respectivamente (P<0,05). Quanto à composição do leite verificou-se que independente do tratamento, permaneceu dentro dos padrões exigidos. Vacas alimentadas com silagem de milho juntamente com o concentrado produziram mais leite que vacas alimentadas com a CH com 48 e 72 horas mais o concentrado, porém a alimentação de vacas leiteiras com CH proporcionou redução no custo do quilograma de leite produzido e melhor margem bruta.
The objective was to evaluate the sugar cane hydrolyzed (SCH) with virgin lime as the only roughage in the diet of dairy cows on the consumption of nutrients, production, milk composition and partial analysis of costs. The treatments were cane in nature (CIN), sugar cane hydrolyzed with 0.5% of lime virgin and 48 hours of storage (SC48), sugar cane hydrolyzed with 0.5% of lime virgin and 72 hours of storage (SCH72), and corn silage (CS), together with the concentrate. Eight Holstein cows, post-peak lactation, were used outlined in Latin square 4x4, with periods of 19 days. The dry matter intake was on averaged 17.42, 10.90, 10.49 and 10.12 kg for the treatment with CS, CIN, SCH48 and SCH72 respectively (P<0.05). The consumption of nutrients in kg/day and percentage of body weight, with the exception of consumption of acid detergent fiber, it was greater (P <0.05) for animals fed with CS than the animals fed with other treatments. For treatments containing sugar cane was verified that the neutral detergent fiber consumption was higher for SCH72 on CIN, both similar to SCH48. Milk production was on average 13.29, 9.55, 10.45 and 11.10 kg/day for the treatment with CS, CIN, SCH48 and SCH72 respectively (P<0.05). About milk composition it was verified that independent of treatment, remained within the required standards. Cows fed with corn silage together with the concentrate produced more milk than cows fed with SCH with 48 and 72 hours more the concentrate, but the feeding of dairy cows with sugar cane hydrolyzed has reduced the cost of kilograms of milk produced and with better gross margin.

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Kurozawa, Louise Emy 1980. "Estudos dos processos de hidrolise enzimatica e secagem por atomização para obtenção de hidrolisado proteico de frango em pó." [s.n.], 2009. http://repositorio.unicamp.br/jspui/handle/REPOSIP/255162.

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Orientadores: Miriam Dupas Hubinger, Kil Jin Park
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: O presente trabalho teve como objetivo o estudo dos processos de hidrólise enzimática e secagem por spray dryer para obtenção de hidrolisado proteico de peito de frango em pó. Este foi realizado em três etapas. Na primeira fase, fez-se um estudo da cinética e a seleção da melhor condição de hidrólise enzimática de peito de frango, utilizando a enzima comercial AlcalaseÒ 2.4L. Um delineamento composto central rotacional (DCCR), totalizando 17 ensaios, foi realizado com o intuito de avaliar o efeito das variáveis: temperatura (43 a 77°C), razão enzima:substrato (0,8 a 4,2% p/p) e pH (7,16 a 8,84) na cinética de hidrólise enzimática de peito de frango e nas respostas: grau de hidrólise (GH) e recuperação de proteína (RP). A hidrólise enzimática foi otimizada de modo a obter maiores valores de GH e RP, sendo que a condição escolhida foi: 52,5°C, 4,2% p/p e pH de 8,0, na qual o hidrolisado apresentou um GH de 31% e uma RP de 91%. Na condição otimizada do processo, foi realizada a caracterização do hidrolisado proteico em termos de composição química, perfil eletroforético e composição total de aminoácidos. Na segunda etapa do projeto, foi avaliado o efeito da concentração (0 a 30%, p/p) e do tipo de agente carreador (maltodextrina 10DE e goma arábica) nas características físico-químicas, de sorção de água e na temperatura de transição vítrea Tg do hidrolisado proteico de frango em pó. Os experimentos para obtenção do produto em pó foram conduzidos em um atomizador de bancada que operou com um fluxo de ar comprimido de 0,6 m3/h, vazão volumétrica do ar de secagem de 19 m3/h, temperatura do ar de 180°C e vazão mássica na alimentação de 0,2 kg/h. A adição de diferentes agentes carreadores e em diferentes concentrações resultou em produtos com características distintas quanto à umidade, densidade, tamanho de partícula e morfologia. A Tg do hidrolisado proteico em pó aumentou com a concentração de agente carreador, melhorando a estabilidade do produto. Na etapa final, a influência das condições operacionais do spray dryer sobre o desempenho do equipamento e sobre as propriedades físico-químicas e a atividade antioxidante do produto em pó foi avaliada através de um delineamento composto central rotacional. As variáveis independentes foram temperatura do ar de entrada (120 a 200°C) e vazão mássica da alimentação (0,1 a 0,38 kg/h). O desempenho operacional do spray dryer foi avaliado através do rendimento, temperatura do ar de saída, eficiência térmica do processo e produtividade, obtidos através de um balanço de massa e de energia no secador. As propriedades físico-químicas do produto em pó foram caracterizadas quanto à umidade, teor de proteína, diâmetro médio das partículas, densidade volumétrica e morfologia
Abstract: The present work had as aim to study the processes of enzymatic hydrolysis and spray drying to obtain a protein hydrolysate of chicken breast meat powder. This work was divided into three sections. In the first part, enzymatic kinetics and selection of the best condition of enzymatic hydrolysis, using the commercial enzyme AlcalaseÒ 2.4L, were evaluated. A central composite rotatable design (CCRD) with three variables was used to estimate the influence of the independent variables: temperature (43 to 77°C), enzyme: substrate ratio (0.8 to 4.2% w/w) and pH (7.16 to 8.84) on the kinetics reaction and on the responses: degree of hydrolysis (DH) and protein recovery (PR). Using response surface methodology, the enzymatic hydrolysis was optimized to obtain the maximum DH and PR. The optimum conditions determined were the following: 52.5°C, 4.2% (w/w) enzyme:substrate ratio and a pH value of 8.0. Under these conditions a degree of hydrolysis of 31% and protein recovery of 91% were obtained. A characterization of the protein hydrolysate obtained using the optimized process conditions was carried out, evaluating the chemical composition, electrophoretic profile and amino acid composition. In the second part of this work, the effect of concentration (0 to 30% w/w) and type of carrier agent (maltodextrin 10DE and gum Arabic) on the physico-chemical properties, water sorption and glass transition temperature of spray dried chicken breast protein hydrolysate. The spray drying process was performed using a laboratory spray dryer. The equipment was operated with air compressed volumetric flow rate of 0.6 m3/h, air volumetric flow rate of 19 m3/h, inlet air temperature of 180°C and feed flow rate of 0.2 kg/h. The following properties: moisture content, bulk density, particle distribution and mean diameter; and the morphology, were affected by the addition of maltodextrin or gum Arabic. With respect to powder stability, the glass transition temperature increased with increasing carrier agent concentration. And the last part of the work, the influence of operational conditions of spray dryer on the equipment performance, physico-chemical properties and antioxidant activity of spray dried protein hydrolysate was evaluated by a central composite rotatable design. The independent variables were inlet air temperature (120 to 200°C) and feed flow rate (0.1 to 0.38 Tkg/h). The spray dryer performance was analyzed by process yield, outlet air temperature, thermal efficiency and dryer productivity, obtained by mass and heat transfer. The physicochemical properties of powders were characterized in respect to moisture and protein content, particle distribution and mean diameter, bulk density and morphology
Doutorado
Engenharia de Alimentos
Doutor em Engenharia de Alimentos

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Rodrigues, Leonarde do Nascimento. "Espectroscopia por FTIR de variedades híbridas de bagaço de cana-de-açucar pré-tratados para produção de etanol celulósico." Universidade Federal de Juiz de Fora (UFJF), 2012. https://repositorio.ufjf.br/jspui/handle/ufjf/4912.

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CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
A energia é imprescindível para a economia e para o desenvolvimento do país. A iminente escassez de combustíveis fósseis e as atuais preocupações ambientais têm despertado uma nova corrida para as fontes de energia renovável. No Brasil, o uso do etanol de primeira geração é produzido por meio da fermentação do caldo de cana e o etanol de segunda geração ou etanol celulósico é produzido a partir do bagaço da cana-de-açúcar. O bagaço é normalmente queimado no próprio ambiente onde é produzido para geração de energia no processo de extração do caldo, podendo ser aproveitado para aumentar a produção de etanol celulósico. Neste trabalho, são apresentados resultados com base na utilização da espectroscopia no infravermelho por transformada de Fourier (FTIR) para caracterizar o processo de fragmentação do bagaço, visando à produção de etanol celulósico, a otimização do processo e ao entendimento teórico e experimental da espectroscopia por FTIR. A técnica de FTIR foi utilizada para caracterizar o bagaço pré-tratado de cinco variedades híbridas de cana-de-açúcar e para detectar diferenças entre essas variedades para produção de etanol. As amostras foram dividas da seguinte maneira: (a) Bagaço in natura; (b) Bagaço Extraído; (c) Celulignina; (d) Polpa celulósica. Foram caracterizadas 20 amostras. Em (a), as amostras foram apenas moídas com o objetivo de identificar as características ópticas do bagaço sem tratamento. Em (b), o bagaço foi pré-tratado com água e etanol para extração dos compostos não estruturais. Na etapa (c), o bagaço sofreu hidrólise ácida com ácido sulfúrico para romper a estrutura lignocelulósica e para remover o conteúdo de hemicelulose. Na etapa (d), o bagaço sofreu hidrólise alcalina com hidróxido de sódio para remover o maior conteúdo possível de lignina. Nas vibrações moleculares do bagaço in natura, foram obtidas bandas entre 1000 e 890 cm-1 que identificam a celulose; entre 1200 e 1000 cm-1 para hemicelulose e celulose; 1247 cm-1 para hemicelulose e lignina; entre 1430-1300 cm-1 com sobreposição para bandas de celulose, hemicelulose e lignina; entre 1610-1460 cm-1 para lignina; 1735 cm-1 para hemicelulose; entre 2920-2850 cm-1 para celulose; e entre 3800-3000 cm-1 para características de celulose cristalina. No processo de extração com água e etanol, não houve diferença. A hidrólise ácida foi efetiva na ruptura da estrutura lignocelulósica e na remoção de grande parte da hemicelulose, o que foi determinado pela diminuição ou pelo desaparecimento de algumas bandas. A hidrólise alcalina removeu parte da lignina e foi responsável pelas mudanças na estrutura lignocelulósica, comprovadas pelos deslocamentos de algumas bandas. Concluiu-se que o bagaço de cana pré-tratado com hidrólise ácida e alcalina tem ótimas condições de utilização para hidrólise enzimática e para fermentação a etanol e que as variedades de bagaço respondem de forma semelhante ao pré-tratamento.
Energy is indispensable for the economy and development of the Brazilian State. The imminent fossil fuels scarcity and current environmental concerns has attracted a new race for renewable energy sources. In Brazil, the use of first generation ethanol is produced by sugarcane juice fermentation and the second ethanol generation or cellulosic ethanol is produced from sugarcane bagasse. This residue is burned normaly in the place where is produced for energy generation in the juice extraction process, that can to be utilized for celulosic ethanol. In this context, the work present results based in use of optical Fourier transform infrared spectroscopy (FTIR) to characterize fragmentation process of sugarcane bagasse for ethanol cellulosic production and to otmize this process as well as to understand FTIR spectroscopy theory and experimentation. This technique was utilized to characterize pretreated bagass from five hybrid sugarcane varieties an to detect difference amont these varieties for ethanol production. Samples were divides as follow: (a) bagasse in nature; (b) bagasse extracted; (c) acid hidrolysis; (d) alkaline hidrolysis. 20 samples were characterized. In (a) samplas were only ground with objective to identify bagass optical characteristics no treatment. In (b) bagasse was pretreated with water and ethanol to extract non-structural compounds. In (c) bagasse suffered acid hydrolisis with sulfuric acid to disrupt bagasse lignocellulosic structure and to remove content hemicellulose and step (d) bagasse suffered hidrolisis alkaline with sodium hidroxide to remove most possible content of lignin. In molecular vibrations from in nature bagasse were obtained bands among 1000 and 890 cm-1 that identify cellulose charateristics, 1200 and 1000 cm-1 for hemicellulose and cellulose, 1247 cm-1 for hemicellulose and lignin, 1430 and 1300 cm-1 with superposition of cellulose, hemicellulose and lignin bands, among 1610 and 1460 cm-1 for lignin, 1735 cm-1 for hemicellulose, 2920 and 2850 cm-1 for cellulose and 3800 and 3000 cm-1 for crystalline cellulose characteristics. In the extraction process with water and ethanol were not observed difference. Acid hidrolysis was effective to disrupt lignocellulisic structure and to remove most part of hemicellulose, determined by decrease or disappearance of some bands. Alkaline hidrolysis removed part of lignin and was responsible by changes in the ligninocellusolic structure, provened by some bands displacements. It was concluded that pretreat sugarcane bagasse with acid and alkaline hidrolisis have great conditions of utilization to enzimatic hidrolisis and fermentation to ethanol and that bagasse varieties respond similarly to pretreatment.

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Massucatto, Denis. "Investigação da cinética de lipase através de espectroscopia de fluorescência." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/75/75131/tde-25082009-164952/.

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As enzimas constituem parte essencial à vida, sendo catalisadores capazes de aumentar em várias ordens de grandeza a velocidade da reação. As lipases, que catalisam a hidrólise de triacilglicerídeos, são enzimas versáteis e de fácil obtenção e por isso estão presentes em diversos setores da indústria e também constituem tema de estudo no meio acadêmico. Tem-se como os objetivos principais deste trabalho a elaboração de um método para se avaliar a cinética hidrólise de lipase suportada por intermédio de espectroscopia de fluorescência. O sistema utilizado foi o DAQ (diaceto-quinizarina) / quinizarina. Este sistema é propício, pois a DAQ, que não é fluorescente, quando hidrolisada resulta na quinizarina, altamente fluorescente. Para se tratar a cinética de hidrólise foi desenvolvido um modelo considerando-se duas etapas seqüenciais de hidrólise, uma vez que a enzima catalisa a quebra de apenas um grupo éster por ciclo catalítico. O modelo mostrou-se bastante fiel no ajuste dos dados experimentais obtidos, sendo possível obter a constante cinética envolvida no processo global de hidrólise, que constitui uma combinação linear das constantes cinéticas dos processos elementares.
Enzymes are essential to life and are capable to increase in many orders of magnitude the velocity of reaction. Lipases, that catalyses the hydrolysis of triacylglyceride, are versatile enzymes and easy to obtain and are present in many industry segments and also constitutes academic studies. The objective of this work is the elaboration of a method to evaluate the hydrolysis kinetic of immobilized lipase through fluorescence spectroscopy. The system used was DAQ (diacetate-quinizarin) / quinizarin. This system is auspicious because DAQ, not-fluorescent, when hydrolyzed results quinizarin, highly fluorescent. To treat the hydrolysis kinetic, a model that consider a twostep sequential reaction were developed, once the enzymes breaks only one ester in each catalytic cycle. The model agreed with the experimental data, and it was possible to obtain the global kinetic constant, that is a linear combination of the elementary constants

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Tarrés, Farrés Joaquim Agustí. "Endo-β-1,4-glucanasa para la fabricación de micro/nanocelulosa: propiedades y aplicaciones." Doctoral thesis, Universitat de Girona, 2017. http://hdl.handle.net/10803/456211.

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In the recent years, significant interest on the production, characterization and application of cellulose nanofibers has brought out among scientific and technic authorities. This special attention mainly comes from their biodegradability, renewability and versatility, making them able to be used for several applications and fields. This topic outbreak took place about ten years ago, fact that is confirmed by the exponential increase on scientific publications and patents since then. In a nutshell, the present thesis aims to demonstrate that enzymatically hydrolyzed cellulose nanofibers can be successfully produced and used in several sectors. Their versatility, availability, low cost and low environmental impact justify the ongoing research in this field
En els darrers anys, entre la comunitat científica i tecnològica s’ha despertat un gran interès en la producció, caracterització i utilització de nanofibres de cel·lulosa. Aquesta especial atenció es deu, principalment, al seu caràcter biodegradable, el seu origen renovable i la versatilitat que presenten, fent-les aptes per ser utilitzades en multitud d’aplicacions. L’esclat d’aquesta temàtica de recerca va tenir lloc aproximadament deu anys enrere, doncs només cal observar el creixement exponencial de publicacions científiques i patents des d’aleshores. De manera general, la present tesi pretén demostrar que les nanofibres de cel·lulosa obtingudes mitjançant un pretractament d’hidròlisi enzimàtica poden ser produïdes de forma efectiva, de manera que pugin ser aplicades en una gran varietat de camps científics i tecnològics. La seva gran versatilitat, disponibilitat, baix cost i baix impacte mediambiental, justifiquen que en el futur es continuï amb la seva investigació sobre noves aplicacions

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Muselli, Alain. "Analyse des mélanges complexes de volatils issus des végétaux." Habilitation à diriger des recherches, Université Pascal Paoli, 2007. http://tel.archives-ouvertes.fr/tel-00803254.

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Ce travail constitue un recueil des mes activités d'enseignement et de recherche postdoctorales réalisées au sein du laboratoire " Chimie des Produits Naturels " (CPN) dans le cadre du projet de recherche " Ressources Naturels " soutenu par l'UMR CNRS 6134 " Sciences de l'Environnement " de l'Université de Corse Pasquale Paoli. Les travaux concernent la caractérisation des Plantes aromatiques et médicinales (PAM) et des produits de l'agroalimentaire au travers des mélanges complexes volatils qui en sont issus. Ces mélanges complexes sont des huiles essentielles, des hydrolats, des extraits aux solvants et des fractions volatiles. Les différentes étapes de la séquence analytique ont été examinées à savoir, le choix des végétaux et leur échantillonnage, la préparation de l'échantillon, son analyse proprement dite, l'interprétation des résultats au moyen de l'outil statistique et leur valorisation au travers de la recherche de principes actifs. La première partie vise à caractériser les huiles essentielles, les hydrolats, les extraits aux solvants et les fractions volatiles issus de PAM et ainsi que les arômes des huiles d'olives et de jus d'agrumes. Pour cela, nous avons examiné les potentialités de méthodes dites alternatives à l'hydrodistillation, méthode conventionnelle pour l'obtention des huiles essentielles et des hydrolats, telles que l'extraction assistée par micro-ondes et la MicroExtraction en Phase Solide. L'analyse proprement est réalisée au laboratoire CPN à l'aide de techniques chromatographiques telles que la Chromatographie en Phase Gazeuse (CPG) pour la quantification et la CPG couplée à la Spectrométrie de Masse (CPG-SM) pour l'identification des constituants des mélanges. Nous avons optimisé la séquence analytique en utilisant la complémentarité des techniques telles que la chromatographie sur colonne, l'utilisation de la SM en mode ionisation chimique et de la Résonance Magnétique Nucléaire pour l'identification de molécules absentes des bibliothèques de références. La deuxième partie concerne le développement d'un axe de recherche nouveau qui vise à mettre en évidence des principes actifs au travers de l'étude des propriétés antibactériennes et antifongiques des huiles essentielles et des extraits de végétaux. Nous avons mis en évidence les propriétés biologiques d'huiles essentielles et d'extraits sur un certain nombre de bactéries impliquées dans des infections nosocomiales et alimentaires. La dernière partie développe les perspectives de travail qui visent à renforcer les travaux sur les PAM et sur les produits identitaires de l'agroalimentaire produits en Corse en explorant de nouvelles matrices d'études (fraction lourde) et de nouvelles techniques d'extraction. La valorisation des mélanges complexes issus des végétaux par la recherche de nouveaux antibiotiques surpassant les mécanismes de résistance des bactéries et de nouveaux antioxydants reste un challenge scientifique d'avenir.

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Saad, Bessem. "Matrix Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry som verktyg för att detektera nedbrytning av Ceftolozan/Tazobaktam orsakad av karbapenemaser." Thesis, Örebro universitet, Institutionen för hälsovetenskaper, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-84598.

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Under senare år har en särskilt hög resistensutveckling observerats hos gramnegativa bakterier inom familjen Enterobacteriaceae. Den främsta resistensmekanismen utgör produktion av så kallade "extended-spectrum β-lactamases" (ESBL) och särskilt oroväckande är karbapenemaser (ESBLCARBA) som har förmåga att bryta ner ett flertal olika grupper av β-laktamantibiotika. Matrix Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS) har utforskats som metod för snabb detektion av karbapenemasaktivitet genom analys av nedbrytning av antibiotika. Syftet med denna studie var att utvärdera om MALDI-TOF MS kan användas som metod för att detektera enzymatisk nedbrytning av Ceftolozan/Tazobaktam samt att undersöka vilka enzymer som uppvisar nedbrytning av antibiotikan. Sju karbapenemasproducerande isolat och en β-laktamasnegativ kontrollstam användes i studien. Isolaten inkuberades 120 min respektive 270 min med antibiotika (1mg/ml) i en buffertlösning (0,08% ammoniumbikarbonat, pH 8). Efter centrifugering analyserades supernatanten med MALDI-TOF MS. Nedbrytning av Ceftolozan detekterades hos samtliga karbapenemasproducerande stammar, utom hos E. coli med NDM-1 produktion. Nedbrytningstoppar av Tazobaktam detekterades emellertid enbart hos stammar med OXA-48 och NDM-7 produktion. Tydligast nedbrytning sågs efter 120 min. För tydligare visualisering av nedbrytningstoppar bör metoden dock optimeras med avseende på matrix, buffert och antibiotikakoncentration.
In recent years, an alarming increase of antibiotic resistance has been observed in Gram-negative bacteria, classified in the family Enterobacteriaceae. The main resistance mechanism is the production of extended-spectrum β-lactamases (ESBL). Particularly worrisome is the production of carbapenemases (ESBLCARBA) due to their ability to hydrolyze a broad range of β-lactams. Recently, Matrix Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS) has been investigated as a method for rapid detection of carbapenemase activity through observation of antibiotic degradation. The aim of this study was to investigate whether MALDI-TOF MS can be used as a method to detect degradation of Ceftolozane/Tazobactam as well as to examine which enzymes that possess the ability to hydrolyze the antibiotic. A total of seven carbapenemase-producing strains were used in the study. The experiment also included a β-lactamase-negative isolate as a negative control. The strains were incubated with antibiotic (1mg/ml) in a buffered solution (0,08% ammonium bicarbonate, pH 8) for 120 min and 270 min. The supernatant, after centrifugation, was analyzed by MALDI-TOF MS. All the carbapenemase-producing strains demonstrated hydrolysis of Ceftolozane, except for NDM-1 producing E. coli. However, mass peaks corresponding to the degradation of Tazobactam were only detected in strains producing OXA-48 and NDM-7. The degradation of Ceftolozane/Tazobactam was most apparent after 120 minutes. However, to better enable detection of mass peaks, further optimization is needed in regard to appropriate matrix, buffer and antibiotic concentration.

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Mercier, Guillaume. "Modélisation de parcs d'hydroliennes à flux transverse avec une méthode d'équivalence." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENI061/document.

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L'exploitation de l'énergie cinétique des courants marins ou fluviaux est une source d'énergie prometteuse et renouvelable. Les performances hydrodynamiques des hydroliennes sont à ce jour bien connues et l'attention se porte sur la compréhension des phénomènes de parc et l'interaction entre machines. Ce document présente la construction d'un modèle simplifié (ou méthode d'équivalence) pour les turbines à axe de rotation vertical. Une étape préliminaire consiste à valider l'utilisation de la méthode de maillage rotatif proposée par Code_Saturne (solveur CFD open source). La simulation de la turbine Darrieus/Achard A10 en 2D met en évidence une bonne concordance des mesures expérimentales (PIV). Cet outil sert dans une seconde étape à mettre au point un modèle simplifié de ces mêmes turbines. Celui-ci consiste à représenter la turbine dans l'écoulement par son équivalent en termes sources de quantité de mouvement sur la base d'une paramétrisation efficace des données empiriques. La méthode est validée pour une large plage de vitesses de rotation et de confinements, et sur plusieurs machines. La représentation du sillage par par les deux méthode de simulation est ensuite étudiée en détail. Des mesures par la technique de LDV dans le sillage proche d'un modèle réduit sont effectuées et établissent une référence expérimentale nécessaire pour ce type de machine. La dépendance forte des deux méthodes de simulation aux paramètres et aux modèles de turbulence est constatée. Deux phénomènes principaux sont relevés : la diffusion turbulente et les instabilités à grandes échelles. Des calculs de rendement sur des dispositions de machines variables illustrent l'applicabilité du modèle. Ils mettent notamment en avant l'effet positif de l'intensité turbulente ambiante sur le rendement dans un parc
Harnessing kinetic energy from oceans or rivers is a promising source of renewable energy. The hydrodynamical performance of water turbines is well known and the focus is now on array optimization and turbine interaction. The present document aims to introduce a new modeling solution for vertical axis water current turbine of Darrieus/Achard type and its construction methodology. A preliminary stage consists in the validation of the new sliding mesh method available in Code_Saturne, EDF CFD open source solver. The good results obtained by comparison with PIV measurements on the Achard type turbine allow the use of this method as a reference tool. The second stage sees the construction of an equivalence model for the Darrieus turbine using momentum source terms. These terms are calculated thanks to an efficient parametrization of empirical data. The comparison of the model with full geometry calculation shows a good agreement in terms of power for a wide range of rotational velocity and blocking ratio. LDV measurements in the near wake of a small scale Achard turbine give a necessary reference set of data. The wake given by both simulations is strongly dependent of turbulence parameters or models, with the cohabitation of two main phenomena : momentum turbulent diffusion, and large scale fluctuations. To conclude, a calculation of the power output for several turbine distributions in an array illustrates the model capability

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Jager, Eliézer. "Controle da liberação do éster etílico de indometacina a partir de nanocápsulas poliméricas através da variação da concentração do monoestearato de sorbitano." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2008. http://hdl.handle.net/10183/13723.

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O trabalho tem como objetivo determinar a influencia da concentração de monoestearato de sorbitano, componente do núcleo oleoso das nanocápsulas, na cinética de liberação do éster etílico de indometacina a partir de nanocápsulas de poli(ε-caprolactona) (PCL). Com este propósito o éster etílico de indometacina foi associado a cada sistema e sua hidrólise alcalina foi realizada para simular uma condição sink. A velocidade de consumo do éster etílico de indometacina foi menor conforme o aumento da concentração do monoestearato de sorbitano. O tempo de meia-vida do consumo do éster etílico de indometacina associado as nanocápsulas foi relacionado com a concentração do monoestearato de sorbitano, sendo maior, enquanto maior a concentração do monoestearato. O mecanismo de liberação foi determinado como sendo transporte anômalo. Foi observada uma relação linear direta entre o aumento da concentração do monoestearato de sorbitano e a concentração de partículas nas suspensões de nanocápsulas (R2=0,9711). Mistura de outras nanopartículas que não as nanocápsulas, foram observadas e caracterizadas. O fluxo difusional do éster a partir das nanocápsulas foi determinado e diminuiu significativamente com o aumento da concentração do monoestearato, devido a mudanças na viscosidade do núcleo das nanocápsulas com o aumento da concentração do monoestearato de sorbitano. Por fim, os resultados demonstraram que o principal fator que contribui para o retardo no tempo para o consumo do éster etílico de indometacina é a relação direta entre a concentração do monoestearato de sorbitano e a permeabilidade das nanocápsulas (R=0,9894).
The aim of this work was to evaluate the influence of the sorbitan monoestearate concentration, one of the components of the oil core of the nanocapsules, in the release kinetic of the indomethacin ethyl ester-loaded poli(ε-caprolactone) nanocapsules. In this way, the indomethacin ethyl ester was entrapped within each system and its alkaline hydrolysis was carried out to simulate a sink condition. The rate for the indomethacin ethyl ester consumption decreased with the increase in sorbitan monostearate concentrations. The indomethacin ethyl ester half-live was related to the sorbitan monostearate concentration, increasing as the sorbitan monostearate concentration increased. The drug release mechanism was determined as anomalous transport. Linear correlations were obtained between the increase in the sorbitan monostearate concentration and the particles concentration in the suspensions (R2 = 0.9711). Mixture of different nanoparticles that are not nanocapsules were observed by density gradient and characterized. The indomethacin ethyl ester fluxes from the nanocapsules were determined and presented a decrease of the flux as the sorbitan monostearate concentration increased. This result was related to changes in the oil core viscosity caused by the variation of the sorbitan monostearate concentration. Finally, the results demonstrated that the main factor that contributes for the delaying in the time for the indometahcin ethyl ester consumption was the direct relation between the sorbitan monostearate concentration and the apparent permeability of the nanocapsules (R2 = 0.9894).

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Moraes, Edgar Perin. "Hidrólise de castanha-do-pará, aveia e trigo com resina de troca catiônica e determinação de aminoácidos, ácidos graxos e sacarídeos utilizando eletroforese capilar." Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/46/46133/tde-24032009-112741/.

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A presente dissertação de mestrado propõe o estudo da hidrólise catalítica de proteínas utilizando resina de troca catiônica, para separação e análise seqüencial de aminoácidos, ácidos graxos e sacarídeos presentes em aveia, trigo e castanha-do-pará via eletroforese capilar. Os processos de hidrólise comumente utilizados para proteínas destroem alguns aminoácidos, como a rota em meio ácido (asparagina, glutamina, triptofano tirosina, serina e treonina) e em meio básico (serina, treonina, arginina e cisteína). O processo de hidrólise de proteínas utilizando-se uma resina de troca catiônica gera um substrato livre de interferentes, pois a fração peptídica é retida na resina e pode ser isolada da matriz. Em adição, a análise dos ácidos graxos e sacarídeos é facilitada, porque adsorção de proteínas na superfície do capilar é um sério problema em eletroforese capilar. Após a hidrólise e análise dos aminoácidos, seqüencialmente foi feita uma extração líquido/líquido no filtrado, sendo a fase orgânica saponificada e posterior análise dos ácidos graxos e, a fase aquosa hidrolisada em meio ácido e posterior análise dos monossacarídeos. Duas resinas foram estudadas, sendo que a Dowex 50WX8-200 da Sigma- Aldrich (St. Louis, EUA) apresentou resultados mais satisfatórios, atingindo níveis de recuperação entre 90,6 e 96,8%. O monitoramento da hidrólise ocorreu registrando-se eletroferogramas de aminoácidos em função do tempo sob três formas: detecção direta de fenilalanina na forma aniônica, detecção direta de histidina na forma catiônica e detecção indireta dos aminoácidos na forma aniônica. Os resultados obtidos mostram que as três formas condizem, podendo-se monitorar a hidrólise por qualquer uma. Estes resultados também concordam com o teor de proteína total obtido pelo método de Kjedahl. Modelos matemáticos que descrevem o comportamento da hidrólise foram descritos, utilizando-se do software Curve Expert 1.3. Para os ácidos graxos, obteve-se êxito somente para a castanha-do-pará, 52,1% de teor de ácidos graxos. Para os monossacarídeos os valores obtidos foram: 12,6% na castanha-do-Pará, 26,5% na aveia e 39,0% no trigo.
In this work, a procedure for hydrolysis of proteins assisted by the protonated form of a strong cation exchanger resin and sequencial analysis of amino acids, fatty acids and saccharides by capillary electrophoresis were studied. Brazilian nut, wheat and oat were characterized by the proposed procedure. The hydrolysis process normaly used for proteins destroys some amino acids, e.g. in the acid hydrolysis (asparagine, glutamine, tryptophan, tyrosine, serine and threonine) and basic hydrolysis (serine, threonine, arginine and cysteine). The catalytic hydrolysis by a protonated cation exchanger produces a clean substract, the amino acids are retained in the resin and can be isolated from the matrix. In addition, the work of analysis of fatty acids and saccharides are facilitated, because adsorption ofproteins onto the silica surface is a serious problem in capillary electrophoresis. After the hydrolysis and amino acids analysis, a liquidlliquid extraction was attempted in the filtrate. The organic phase was saponified for fatty acids analysis and, the aqueous phase was further hydrolysed for monosaccharide analysis. Two resins were invetigated, the Amberlite IRA 120 from Vetec Química (Rio de Janeiro, BR) and the Dowex 50WX8-200 from Sigma-Aldrich (St. Louis, USA). The Dowex resin showed the best results, reaching recoveries from 90,6 to 96,8%. To monitor the hydrolysis amino acids electropherograms were registered, under three forms: direct detection of phenylalanine; direct detection of hystidine and indirect detection of other amino acids. The results showed, that the three forms were similar. Mathematic models to describe the hydrolysis profile were fitted by the Curve Expert 1.3 software. The results for the amino acids analysis were in agreement with Kjedahl\'s method. The fatty acids analysis was tested with success only for brazilian nut, that presented a concentration 54.1 % (total fatty acids). The monosaccharides analysis was tested with sucess for all matrices, showing 12.6% for the brazilian nut, 26.5% for the oat and 39.0% for the wheat.

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Zhou, Zhibin. "Modeling and power control of a marine current turbine system with energy storage devices." Thesis, Brest, 2014. http://www.theses.fr/2014BRES0094/document.

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Ces travaux de thèse concernent l’étude de l’ensemble de la chaîne de puissance d’un système hydrolien utilisant des systèmes de stockage d’énergie pour améliorer la qualité de la puissance produite et la capacité de gestion des échanges d’énergie. Dans un premier temps, les différentes technologies de stockage d’énergie et leurs applications pour lisser les fluctuations de la puissance produite par le système hydrolien sont étudiées et comparées. Ensuite, une stratégie de lissage des fluctuations de la puissance, dues à l’effet de houle (fluctuations de courte durée), est proposée : elle associe une stratégie MPPT avec filtrage (au niveau de la génératrice) à l’utilisation de supercondensateurs pour lisser la puissance injectée au réseau. Puis il est proposé d’utiliser des batteries à circulation d’électrolyte pour la gestion quotidienne de la puissance d’une hydrolienne dans le contexte d’un réseau électrique isolé. Un système hybride hydrolien/batteries/diesel est étudié pour deux configurations simples : le cas d’une alimentation avec une hydrolienne comme sources principales et le cas où les générateurs diesels sont considérés comme sources dominantes. Enfin, des stratégies de limitation de puissance basées sur le défluxage de la génératrice pour contrôler la puissance de l’hydrolienne dans le cas de vitesses de courants marins élevées sont proposées. Dans ce contexte, le contrôle à puissance constante et à puissance maximale en cours de défluxage sont comparés. L’influence des paramètres de la génératrice sur les caractéristiques de fonctionnement commun de la turbine et la génératrice est également étudiée
This PhD thesis models the whole power chain of a marine current turbine (MCT) system and investigates the use of energy storage devices to improve power quality and energy management capability. First, various energy storage technologies concerning their applications to address the power fluctuation phenomena in tidal current generation system are reviewed and compared. Then, a two-stage power smoothing control strategy for compensating swell-induced short-time fluctuations is proposed. The proposed control strategy uses a modified MPPT with filter strategy on the generator-side and supercapacitors on the grid-side for injecting a smoothed power to the grid. Afterwards, a flow battery system for daily energy management of a hybrid MCT/battery/diesel system is proposed. The MCT dominant power supply case and an island power supply (with diesel generators as the main source) are investigated. Finally, power limitation controls with a robust flux-weakening strategy for a PMSG-based non-pitchable MCT system are proposed for over-rated marine current speed periods. In this context, the constant power control and maximum power control modes at the flux-weakening stage are compared; and the influence of the generator parameters on the joint operating characteristics of the turbine and generator are also discussed

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Orenäs, Nissas Sebastian, and Nangyalay Rahimi. "Mätfel vid fuktmätning i emissionsskadad betong." Thesis, KTH, Byggteknik och design, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-231912.

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När människors hälsobesvär misstänks vara byggnadsrelaterat är det viktigt att klarlägga källan till problemet. Fukt kan vid högre nivåer ge upphov till mikrobiella eller kemiska reaktioner som orsakar emissioner från byggnadsmaterial som kan ha negativa hälsoeffekter. För att utreda om byggnaden är problemkällan görs skadeutredningar. I utredningarna är det viktigt att identifiera vilka emissioner som förekommer i inomhusmiljön för att kunna åtgärda den eventuella skadan. Med hjälp av fuktprofiler som skapas genom fuktmätningar kan det utredas om varifrån fukten kommer. En vanlig orsak i Norden till förhöjda koncentrationer av emissioner i inomhusmiljön är fuktskadade betongkonstruktioner med en pålimmad plastmatta. I en sådan konstruktion utgör plastmattan ett tätt skikt som inte låter fukten i betongen avdunsta. Betong, som är alkalisk, kan i kombination med höga fuktnivåer utlösa en kemisk process, så kallad alkalisk hydrolys, som bryter ned mjukgörare i golvlim och PVC-mattor. Detta leder till att nedbrytningsprodukterna 2-etyl-1-hexanol och n-butanol dels emitteras till inomhusluften och dels migrerar ned i betongen där de fixeras. Det är i det skedet betongen blir emissionsskadad på grund av att de kemiska ämnena som fixerats i betongen kan lagras där under en lång tid och kan om förhållandena förändras, exempelvis vid renovering, avge dessa ämnen till inomhusluften. Eftersom 2-etyl-1-hexanol och n-butanol utgör majoriteten av nedbrytningsprodukterna, används de därför som indikatorämnen vid skadeutredningar. Om indikatorämnena upptäcks i inomhusluften är det troligt att en skada i golvkonstruktionen har inträffat och detta kontrolleras då med fuktmätningar. Problemet med fuktmätningar i emissionsskadad betong är dock att det befaras av fuktskadeutredare att dessa indikatorämnen påverkar fuktmätningarna genom att man mäter till en lägre relativ fuktighet (RF) än vad det faktiskt är. Examensarbetet är utformat som ett experimentellt arbete med fuktmätningar som utförts i Polygon AK:s laboratorium. I laborationerna testades huruvida indikatorämnena, 2-etyl-1-hexanol samt n-butanol, påverkar fuktmätningar. Detta gjordes genom att prover med ren betong först RF-bestämdes för att sedan droppa i ovanstående ämnen i proverna och därefter följdes utvecklingen i RF. Vidare kontrollerades eventuell drift i mätinstrumenten genom egenkontroller både före och efter varje uppföljning. Mätresultaten från gjorda försök visade att den effekt som befarats av skadeutredare ej märkts av, det vill säga att indikatorämnena skulle ha en påverkan genom att fuktnivån mäts till något lägre jämfört med den verkliga fuktnivån. Effekten påvisades varken genom lägre uppmätta fuktnivåer eller genom mätinstrumentens drift.
When people's illness are suspected to be building-related, it is important to clarify the source of the problem. Moisture at higher levels can trigger microbial or chemical reactions which causes emissions from building materials that may have adverse health effects. In order to investigate whether the building is the source of the problem or not, indoor environment investigations are conducted to investigate the matter. In the investigations it is important to identify what kind of emissions that occurs in the indoor environment in order to fix the possible damage or damages. Using moisture profiles created with moisture measurements, it is possible to determine where the moisture comes from. A common cause in the Nordic countries for increased concentrations of emissions in the indoor environment is moisture-damaged concrete structures with a glued plastic mat. In such constructions, the plastic mat is a compact layer that does not allow the moisture in concrete to evaporate. Concrete, which is alkaline, can in combination with high moisture levels trigger a chemical process, called alkaline hydrolysis, which degrades plasticizers in floor adhesives and plastic mats. This results in the degradation products 2-ethyl-1-hexanol and n-butanol, which are being emitted to the indoor air and partly migrating down into the concrete where they are fixed. At that moment the concrete gets emission-damaged because of the degradation products that has been fixed into the concrete where they can be stored for a long time and can with changed conditions, for instance during renovation, emit these degradation products to the indoor air. Since 2-ethyl-1-hexanol and n-butanol constitutes the majority of degradation products, they are therefore used as indicators during damage investigations. If the indicators are detected in the indoor air, it is likely that a damage has occured in the floor construction and this is later checked with moisture measurements. However, the problem with moisture measurements in emission-damaged concrete is that some investigators fears that these indicators affects the moisture measurements by measuring a lower relative humidity (RH) than it actually is. The thesis is structured as an experimental work with moisture measurements performed in Polygon AK's laboratory. In the laboratory it was tested whether the indicators, 2-ethyl-1-hexanol and n-butanol, affects moisture measurements. This was done with specimens of pure concrete by first determining the RH followed by dropping the indicators into the samples and then the development in RH was followed. Furthermore, eventual drifting in the measuring instruments was checked before and after each follow-up. The measurement results from the experiments showed no effect of what the damage investigators feared of, that the indicators would have an impact by measuring the moisture level lower than the actual moisture level. The effect was not detected either by lower measured humidity levels or by drifting of the measuring instruments.

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Thenstedt, Niklas. "Detektion av hydrolyserad β-laktamantibiotika i plasma med Matrix-Assisted Laser Desorption Ionization – Time of Flight Mass Spectrometry och Liquid Chromatography tandem Mass Spectrometry." Thesis, Örebro universitet, Institutionen för hälsovetenskaper, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-84594.

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Introduktion Antibiotikaresistens är ett globalt växande problem. Till gruppen β-laktamantibiotika hör piperacillin-tazobaktam och cefotaxim som båda verkar genom att försvaga cellväggen med kovalenta bindningar till peptidoglykanlagret som lyserar cellen. E. coli och K. pneumoniae tillhör gruppen Enterobacteriaceae, som är en del av den humana tarmfloran och ofta förekommande vid urinvägsinfektion och sepsis. Utvidgat Spektrum β-Laktamas (ESBL) är ett enzym som finns hos Enterobacteriaceae och som hydrolyserar β-laktamantibiotika. Matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) är en kvalitativ analysteknik för detektion av kemiska föreningar i avseende på massa och laddning. Kännedom om antibiotikametaboliters molekylvikt vid hydrolys möjliggör detektion. Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS) är en högsensitiv kvantifieringsmetod som separerar molekyler i avseende på polaritet för vidare detektion i avseende på massa och laddning. Syfte Syftet med denna studie var att vidareutveckla en snabb och effektiv metod för att påvisa nedbrytning av piperacillin-tazobaktam och cefotaxim i blodplasma med LC-MS/MS. Material och Metod Tiofaldigt sjunkande koncentrationer av piperacillin-tazobaktam från 2000 till 2 µg/ml, och cefotaxim med koncentrationerna 500 till 0,5 µg/ml analyserades med MALDI-TOF MS, dels intakt men även med bakterierna E. coli och K. pneumoniae med uttryck av olika resistensmekanismer. Vid optimerade koncentrationer spikades plasmaprover med nedbrutet antibiotika som sedan kvantifierades med LC-MS/MS. Resultat Lägsta detektionsgräns med MALDI-TOF MS för intakt och hydrolyserat piperacillin-tazobaktam var 20/2,5 µg/ml. För cefotaxim var lägsta gränsen 5 µg/ml. Med kliniskt relevanta blodkoncentrationer gick hydrolys inte att detektera för. Med tre bakteriekolonier/50 µl kunde dock hydrolys detekteras och kvantifieras med LC-MS/MS. Slutsats Detektion av β-laktamantibiotika är möjligt med både MALDI-TOF MS och LC-MS/MS. För att påvisa hydrolys krävdes större mängder bakterier än förväntat med LC-MS/MS.
Introduction Antibiotic resistance is a global growing problem. Piperacillin-tazobactam and cefotaxime are parts of the group β-lactam antibiotics. The common feature is to inhibit the cell wall synthesis by covalent bindings to the peptidoglycan layer and thereby causing lysis of the bacterial cell. E. coli and K. pneumoniae are members of the Enterobacteriaceae which is a part of the human normal flora but also are commonly associated with urinary tract infections which sometimes develops into to sepsis. Extended Spectrum β-Lactamases (ESBLs) are enzymes with hydrolytic abilities acting on β-lactam antibiotics, expressed by Enterobacteriaceae. The qualitative, Matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) can be used to detect chemical compounds in the ratio of mass to charge in accordance to their molecular weight. Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS) is a highly sensitive two-step method of quantification which first separate molecules by their polarity attraction force and then by the ratio of mass to charge. Aim The aim of this study was to develop a fast and efficient method to determine degradation of piperacillin-tazobactam and cefotaxime in blood plasma by LC-MS/MS. Method Tenfold dilution of piperacillin-tazobactam in concentrations of 2000 to 2 µg/ml, and cefotaxime in concentrations of 500 to 0,5 µg/ml where analyzed by MALDI-TOF MS, intact and also with the bacteria E. coli and K. pneumoniae with different expression of antibiotic resistance. Optimized concentrations where fixed in blood plasma and then quantified by LC-MS/MS. Result The detection limit by using MALDI TOF MS of hydrolyzed as well as non-hydrolyzed piperacillin-tazobactam was 20/2,5 µg/ml. The detection limit in cefotaxime was 5 µg/ml. Hydrolysis could not be detected in clinically fixed blood concentrations. Detection and quantification of hydrolysis by LC-MS/MS was possible in a concentration of three bacteria colonies/50 µl. Conclusion It is possible to detect hydrolysis in both MALDI TOF MS and LC-MS/MS. A larger amount of bacteria than expected was needed to demonstrate hydrolysis In LC-MS/MS.

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Abrahamsson, Louise. "Improving methane production using hydrodynamic cavitation as pre-treatment." Thesis, Linköpings universitet, Tema Miljöförändring, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-128783.

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To develop anaerobic digestion (AD), innovative solutions to increase methane yields in existing AD processes are needed. In particular, the adoption of low energy pre-treatments to enhance biomass biodegradability is needed to provide efficient digestion processes increasing profitability. To obtain these features, hydrodynamic cavitation has been evaluated as an innovative solutions for AD of waste activated sludge (WAS), food waste (FW), macro algae and grass, in comparison with steam explosion (high energy pre-treatment). The effect of these two pre-treatments on the substrates, e.g. particle size distribution, soluble chemical oxygen demand (sCOD), biochemical methane potential (BMP) and biodegradability rate, have been evaluated. After two minutes of hydrodynamic cavitation (8 bar), the mean fine particle size decreased from 489- 1344 nm to 277- 381 nm (≤77% reduction) depending of the biomasses. Similar impacts were observed after ten minutes of steam explosion (210 °C, 30 bar) with a reduction in particle size between 40% and 70% for all the substrates treated. In terms of BMP value, hydrodynamic cavitation caused significant increment only within the A. nodosum showing a post treatment increment of 44% compared to the untreated value, while similar values were obtained before and after treatment within the other tested substrates. In contrast, steam explosion allowed an increment for all treated samples, A. nodosum (+86%), grass (14%) and S. latissima (4%). However, greater impacts where observed with hydrodynamic cavitation than steam explosion when comparing the kinetic constant K. Overall, hydrodynamic cavitation appeared an efficient pre-treatment for AD capable to compete with the traditional steam explosion in terms om kinetics and providing a more efficient energy balance (+14%) as well as methane yield for A. nodosum.
Det behövs innovativa lösningar för att utveckla anaerob rötning i syfte att öka metangasutbytet från biogassubstrat. Beroende på substratets egenskaper, kan förbehandling möjliggöra sönderdelning av bakterieflockar, uppbrytning av cellväggar, elimination av inhiberande ämnen och frigörelse av intracellulära organiska ämnen, som alla kan leda till en förbättring av den biologiska nedbrytningen i rötningen. För att uppnå detta har den lågenergikrävande förebehandlingsmetoden hydrodynamisk kavitation prövats på biologiskt slam, matavfall, makroalger respektive gräs, i jämförelse med ångexplosion. Effekten på substraten av dessa två förbehandlingar har uppmäts genom att undersöka distribution av partikelstorlek, löst organiskt kol (sCOD), biometan potential (BMP) och nedbrytningshastigheten. Efter 2 minuters hydrodynamisk kavitation (8 bar) minskade partikelstorleken från 489- 1344 nm till 277- 281 nm (≤77 % reduktion) för de olika biomassorna. Liknande påverkan observerades efter tio minuters ångexplosion (210 °C, 30 bar) med en partikelstorlekreducering mellan 40 och 70 % för alla behandlade substrat. Efter behandling med hydrodynamisk kavitation, i jämförelse med obehandlad biomassa, ökade metanproduktionens hastighetskonstant (K) för matavfall (+65%), makroalgen S. latissima (+3%), gräs (+16 %) samtidigt som den minskade för A. nodosum (-17 %). Förbehandlingen med ångexplosion ökade hastighetskonstanten för S. latissima (+50 %) och A. nodosum (+65 %) medan den minskade för gräs (-37 %), i jämförelse med obehandlad biomassa. Vad gäller BMP värden, orsakade hydrodynamisk kavitation små variationer där endast A. nodosum visade en ökning efter behandling (+44 %) i jämförelse med obehandlad biomassa. Biomassa förbehandlade med ångexplosion visade en ökning för A .nodosum (+86 %), gräs (14 %) och S. latissima (4 %). Sammantaget visar hydrodynamisk kavitation potential som en effektiv behandling före rötning och kapabel att konkurrera med den traditionella ångexplosionen gällande kinetik och energibalans (+14%) samt metanutbytet för A. nodosum.

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Chin-Hsien, Kao, and 高志先. "Design and analysis of hydrolic piping system." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/65032129580808640910.

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碩士
國防大學中正理工學院
兵器系統工程研究所
91
Piping system design mainly divides calculating head loss of conduits between choosing motive power. This study use hypothetical fuel supply system to proceed to the flow rate experiment, to estimate unknown flow rate of circuit by iteration, and to simulate the piping system by HyPneu. We compare to experimentation, estimation, and simulation each other, and we analysis the relationship of every conduit design methods to know the discrepancy piping design by software between real situation. We can understand to the result of piping system simulating by software is close to the one of circuit iteration and has just a little difference to the one of experiment, and we can get important reference basis of piping design. On the other hand, we use pump characteristic curve and system impendence curve to solve working point of the smallest pump efficiency. We discuss the efficiency of pump parallel connection to obtain the parameter of piping system design, too.

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Namkanisorn, Apinan. "An arrhenius method to study the hydrolic stability of polymer-metal adhesion /." Diss., 2002. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3036273.

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Schwar, Michael T. "Hydrolic restoration of a groundwater-fed sedge meadow wetland in South-Central Wisconsin." 2002. http://www.library.wisc.edu/databases/connect/dissertations.html.

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Lin, Rong-Bin, and 林榮斌. "Different Pretreatment of Agricultural Waste in the Hydrolsis of Cellulose Enzyms – An example of Pinapple Leaf Cellulose." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/75048785074960787681.

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碩士
國立屏東科技大學
生物機電工程系所
96
Taiwan's agricultural waste about 5 million tonnes of annual output, a huge number of agricultural wastes make a great impact to the environment. At present, farmers still use the traditional burial or burning as waste disposal method. It’s necessary to create a new solution for the increasing agricultural waste. If these agricultural wastes can be transformed into resources, it will not only reduce the agricultural waste but also generate the new resources. Biotechnology can be used in a wide area on agriculture waste. The most common method is chemical pretreatment method, it can the reducing sugars from the wood fiber quickly, besides it makes a great enhancement to the renewable energy of agricultural waste. In this study, it use the common agricultural waste（Pineapple leaves, rice-and-banana, bagasse）from Pingtung areas as raw materials. Sulfuric acid and alkali uas catalyst. Concentrated sulphuric acid to 72 percent and hydrolyze it at 30 ℃ for two hours, and then hydrolyze it at 121℃. Do the pre-processing to the dilute acid and alkali at different temperatures (60, 90,120℃), different concentrations (0.5, 1, 1.5 M) and different processing time (20, 40, 60 min) then analysis the percentage of reducing sugar from it. The results showed after compared the control group (CG) and experimental group (EG), it generates more than 3mg reducing suger in EG and only less than 1 mg or 1 mg in control group, Acid hydrolysis in the pre-treatment temperature and time and concentration, with the temperature and the concentration of reducing sugar concentration gradually increased, in 1 M and 1.5 M. before the temperature 90 and 120 pre-treatment at reducing sugar produced 13.2 mg and 13.1 mg No significant differences to alkaline. After 1 M. before the temperature at 90℃, 60 min time reducing sugar under the dissolution rate higher. Hydrolysis enzymes in the alkali treatment to deal with concentrations of 1.5 M up to the highest average conversion rate of over 12 percent. In pre-treatment in the enzyme acid hydrolysis results were slightly raise the average conversion rate of around 7.8% in.

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47

Niemiec-Cyganek, Aleksandra. "Badania reakcji hetarylotioglikozydów katalizowanych przez glikozylohydrolazy." Rozprawa doktorska, 2003. https://repolis.bg.polsl.pl/dlibra/docmetadata?showContent=true&id=4604.

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48

Llempén, Coronel Humberto. "1 - Arylo - 4 - Nitroimidazole z 1,4 - Dinitroimidazoli." Rozprawa doktorska, 1991. https://repolis.bg.polsl.pl/dlibra/docmetadata?showContent=true&id=3421.

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49

Niemiec-Cyganek, Aleksandra. "Badania reakcji hetarylotioglikozydów katalizowanych przez glikozylohydrolazy." Rozprawa doktorska, 2003. https://delibra.bg.polsl.pl/dlibra/docmetadata?showContent=true&id=4604.

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50

Llempén, Coronel Humberto. "1 - Arylo - 4 - Nitroimidazole z 1,4 - Dinitroimidazoli." Rozprawa doktorska, 1991. https://delibra.bg.polsl.pl/dlibra/docmetadata?showContent=true&id=3421.

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Dissertations / Theses on the topic 'Hydrolics'

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