Tesis sobre el tema "Filtration of liquid aerosols"
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Mullins, Benjamin James y n/a. "Study of Capture, Fibre Wetting and Flow Processes in Wet Filtration and Liquid Aerosol Filtration". Griffith University. School of Environmental Engineering, 2004. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20040919.124658.
Texto completoMullins, Benjamin James. "Study of Capture, Fibre Wetting and Flow Processes in Wet Filtration and Liquid Aerosol Filtration". Thesis, Griffith University, 2004. http://hdl.handle.net/10072/365591.
Texto completoThesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Environmental Engineering
Faculty of Environmental Sciences
Full Text
Agranovski, Igor Evgenevich y n/a. "Filtration of Ultra-Small Particles on Fibrous Filters". Griffith University. School of Environmental Engineering, 1995. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20050913.164528.
Texto completoAgranovski, Igor Evgenevich. "Filtration of Ultra-Small Particles on Fibrous Filters". Thesis, Griffith University, 1995. http://hdl.handle.net/10072/367392.
Texto completoThesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Environmental Engineering
Faculty of Environmental Sciences
Full Text
Martin, Graham S. "Theoretical and experimental studies of an aerosol coalescing fibrous filter". Thesis, University of Newcastle Upon Tyne, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.265545.
Texto completoScurrah, Katherine Lesley. "Filtration of solid and liquid aerosol particles". Thesis, Loughborough University, 1999. https://dspace.lboro.ac.uk/2134/32098.
Texto completoMead-Hunter, Ryan. "Modelling micro-scale coalescence and transportprocesses in liquid aerosol filtration". Thesis, Curtin University, 2012. http://hdl.handle.net/20.500.11937/1063.
Texto completoSutter, Benjamin. "Étude de l'évaporation d'aérosols liquides semi-volatils collectés sur médias fibreux". Thesis, Vandoeuvre-les-Nancy, INPL, 2009. http://www.theses.fr/2009INPL067N/document.
Texto completoThis study falls within the scope of improving knowledge concerning evaporation of semi-volatile liquid aerosols collected on fibrous filters. Under these conditions, the aerosol evaporation phenomenon causes problems of safety, in particular over-exposure of employees to vapours downstream of general air filtering systems. Furthermore, when controlling aerosol atmospheric concentrations, evaporation results in under-estimation of the sampled aerosol particle phase and this is clearly problematic in exposure prevention terms. The aim of this work was therefore to record a large number of experimental data, both to make up for their scarcity in the literature and to improve previously developed theoretical models. Two experimental approaches were implemented to identify the evaporation process for a collected aerosol. The first, termed the global approach, allowed us to monitor aerosol evaporation by measuring vapour quantity downstream of the filter with respect to time. The second, microscopic, approach considers evaporation of droplets collected on the filter fibres on a microscopic scale. The two approaches implemented during this research lead to agreement on the fact that evaporation of a liquid semi-volatile aerosol cannot be satisfactorily represented by the theoretical models proposed in the literature. Hypotheses are advanced to explain the divergence in evaporation kinetics between theoretical and experimental work
Penicot-Bauge, Pascale. "Étude de la performance de filtres à fibres lors de la filtration d'aérosols liquides ou solides submicroniques". Vandoeuvre-les-Nancy, INPL, 1998. http://docnum.univ-lorraine.fr/public/INPL_T_1998_PENICOT_BAUGE_P.pdf.
Texto completoKnox, Christopher James Henry. "The photochemistry of liquid aerosols". Thesis, University of Canterbury. Chemistry, 2002. http://hdl.handle.net/10092/6076.
Texto completoHuang, Shih-Hui Ruth. "New Methods of Controlling Biological Aerosols". Thesis, Griffith University, 2010. http://hdl.handle.net/10072/366385.
Texto completoThesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Griffith School of Engineering
Science, Environment, Engineering and Technology
Full Text
Ma, Yilin. "Developments and improvements to the particle-into-liquid-sampler (PILS) and its applications to Asian outflow studies". Diss., Available online, Georgia Institute of Technology, 2004:, 2004. http://etd.gatech.edu/theses/available/etd-06072004-131244/unrestricted/ma%5Fyilin%5F200405%5Fphd.pdf.
Texto completoMcCutcheon, Heather Jean. "Methodological issues in ultra-low concentration aerosol sampling". Oklahoma City : [s.n.], 2002. http://library.ouhsc.edu/epub/theses/McCutcheon-Heather-Jean.pdf.
Texto completoAndan, Saravanan. "Modeling of Drainage in Coalescence Filtration". University of Akron / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=akron1268145371.
Texto completoSanchez, Erin. "Filtration Efficiency of Surgical Masks". Scholar Commons, 2010. https://scholarcommons.usf.edu/etd/1760.
Texto completoTian, Chenguo. "Filtration of liquid aluminum with reticulated ceramic filters". Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=28932.
Texto completoParameters affecting filtration processes during the initial period were identified, some of which could be quantified numerically using a 2-D computational domain. According to these numerical analyses, the clean filter coefficient for this type of filter was linearly dependent on the dimensionless Stokes velocity of the suspended particles, had a $-$0.96 power dependence on the Peclet number, a $-$6.93 power dependence on the effective porosity of the filter, and exhibited only a weak dependence on the Reynolds number, in the Darcy velocity regime.
The dynamic behaviour of this type of filter was analyzed theoretically and simulated numerically using newly proposed correlations relating the filter coefficient and the pressure drop to the amount of particles captured within the filter (the specific deposit), and a model describing the morphology of captured particles. The simulated results showed that the filtration efficiency and the pressure drop increased with inlet particle concentration and filtration time; these increases were however, insignificant when the inlet particle concentration was less than 1 ppm for filtration periods of two hours, however, when the inlet concentration (initial and continued) reached 10 ppm, the change became appreciable.
Experimental data, obtained from liquid aluminum filtration tests conducted by the author in both laboratory and industrial settings, compared favourably with the numerical results.
Foss, Willard Rodney. "Dynamic processes in single liquid microspheres /". Thesis, Connect to this title online; UW restricted, 1995. http://hdl.handle.net/1773/9911.
Texto completoPerkins, Deborah Davidson. "Characterization and applications of the monodisperse aerosol generation interface for combining liquid chromatography with mass spectometry". Diss., Georgia Institute of Technology, 1988. http://hdl.handle.net/1853/27610.
Texto completoGonzalez, Herrera Luisa Fernanda. "Influence de la gestion des centrales de traitement d’air des réseaux de ventilation de bâtiments sur le développement d’aérosols microbiens". Thesis, Nantes, Ecole des Mines, 2014. http://www.theses.fr/2014EMNA0136/document.
Texto completoFiltration performances of Air Handling Units (AHU) filters regarding particles and microbial aerosols have been studied, as well as the influence of the AHU operational conditions on behavior of microorganisms collected on the filters. A lab-scale AHU with two successive filtration stages was developed and validated for the study of prototype filters with industrial geometries. Three types of filters of different efficiency have been considered : G4, F7 and F9 according to EN 779 Standard. Two configurations of filters were considered: 1) G4 pleated/F7 bag and 2) F7/F9 bag. Filters were sequentially clogged by alumina particles which assured a mineral fraction, and then by micronized rice particles which provides the fungi Penicillium chrysogenum and assures an organic fraction which acts as a substrate for microorganisms. Finally, a microbial aerosol composed by endospores of Bacillus subtilis and spores of Aspergillus niger was nebulized for filters contamination. After clogging, stops and restarts of ventilation were simulated for different durations (10 days or 6 weeks). During restarts of ventilation, particles and microbial aerosols samplings were performed downstream of the filters. Main results are: (i) level of clogging is significantly less important for the 2nd filtration stage than for the first one, (ii) survival of B. Subtilis, growth of P. Chrysogenum and decline of A.niger on the filters whatever the period of time studied, and (iii) during restarts of ventilation, microbial aerosols releasing was not detected for sampled fraction. Moreover, two full-scale AHU were studied during 6 months. One of the AHU studied is equipped with two filters in series: a G4 pleated filter in 1st stage and a F7 bag filter in 2nd stage. This AHU treats the outdoor air to blow it towards the indoor environments. The other one extracts the indoor air to reject it back outdoors. The filters pressure drop, relative humidity and temperature of the air were measured continuously. Filters efficiency regarding particles and microbial aerosols were measured once a month. An original methodology for the monthly estimation of the concentration of microorganisms on the filters was implemented. Main results are: (i) no significant evolution of the filter pressure drop in 2nd stage, (ii) efficiency of G4 filters are comparable to the prototype filtersone, (iii) efficiency of F7 filters are lower than prototype filters one, which can be explained by differences of filtration velocity between the two scales, (iv) after 6 months of operation, concentration of microorganisms on G4 filter of the AHU of extraction is 10 times higher than the G4 filter one of AHU who treats outdoor air
Trottier, Remi A. "Enhancement of the collection efficiency of fibrous filtration in the region of maximum penetration". Thesis, Loughborough University, 1996. https://dspace.lboro.ac.uk/2134/10541.
Texto completoBailey, Andrew Douglas. "An exploratory investigation of crossflow microfiltration for solid/liquid separation in biological wastewater treatment". Master's thesis, University of Cape Town, 1989. http://hdl.handle.net/11427/21915.
Texto completoAbd, ali Safaa Abd Zaid. "Filtration performances of antimicrobial and regular HVAC filters regarding PM10 and microbial aerosols in laboratory and realistic conditions". Thesis, Ecole nationale supérieure Mines-Télécom Atlantique Bretagne Pays de la Loire, 2018. http://www.theses.fr/2018IMTA0088.
Texto completoThis study focused on the performance of a marketed antimicrobial polypropylene fibers filter containing zinc pyrithione (PP/ZPT) at the laboratory and compared to those of a similar filter (PP) with same classification F7 (EN779:2002). The filtration performance at laboratory scale of the 2 tested filters during clogging with PM10 particles was quantified in an experimental set-up with filter pressure drop measurement and particle counting up and downstream of the filters. The microbial growth onto new and used filters, both contaminated by aerosolization with a microbial consortium composed of two bacteria (Staphylococcus epidermidis Gram positive, Serratia marcescens Gram negative and fungal spores (Penicillium chrysogenum). The influence of three parameters on the microbial survival onto filters was examined: the air relative humidity, the presence or absence of Zinc pyrithione (ZPT) as antimicrobial substances and the presence of organic particles. Quantitative analyses by colony forming unit were used to determine the survival after 8 days of the bacteria–fungi consortium collected by the filter. The two filters revealed similar filtration performance in terms of change in pressure drop and particle collection efficiency during their clogging with PM10 particles, meaning that the antimicrobial treatment did not degrade the filtration performance of the filter. At low humidity value of conditioning (50% RH), with new or used filters, with or without antimicrobial treatment, the microbial population onto the filters decreases and possibly will not survive (Serratia). At high humidity value of conditioning (90% RH), the bacteria do not grow onto the new filters, and only the fungi was able to develop. The effect of the antimicrobial treatment with zinc pyrithione is confirmed for new filters in particular regarding the fungi Penicillium. For used filters, the results indicate that the antimicrobial treatment is no more efficient with a significant growth of the Penicillium, the endemic species of the micronized rice particles (PM10) collected by the filters; the two populations of bacteria significantly decrease with or without antimicrobial treatment. In a second step, the filtration performances of the 2 filters tested previously was investigated in realistic conditions with a semi-urban outdoor air over a 7 months period. The behavior of the outdoor microorganisms onto the filters (growth/mortality) was observed. Two filtration units were operating at IMT Atlantique location, one containing the PP/ZPT filter and the second the PP filter. Each unit filtered the same semi-urban air. Both filtration units operated continuously and several parameters were monitored throughout the operating period: temperature, relative humidity, filter pressure drop, filter particle collection efficiency, inlet particle mass concentration, and microbial concentrations; in addition, the microbial concentration onto the filters was quantified for 3 times (every 2 months) from an innovative methodology based on media coupons. The filtration performances of the two tested filters in terms of changes in pressure drop and particle collection efficiency were different than those obtained in the Laboratory scale. The methodology of coupons permitted to study the behavior of the microorganisms throughout the study. The antimicrobial effect of the zinc pyrithione was confirmed regarding the inhibition of the fungi cultivated on the DRBC agar with no influence of the level of clogging of the filter (mass of particles deposit)
Marangoni, Federico. "Filter cleaning with liquid droplets". Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017.
Buscar texto completoHornsby-Myers, Jennifer L. "Use of track-etched polycarbonate filters in series to mimic the total human lung deposition in the ultrafine and fine particle range from 0.03 to 0.40 [mu]m". Morgantown, W. Va. : [West Virginia University Libraries], 2000. http://etd.wvu.edu/templates/showETD.cfm?recnum=1732.
Texto completoTitle from document title page. Document formatted into pages; contains ix, 87 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 69-73).
Bharadwaj, Rahul. "Improved Performance with Layer Orientation Incorporated Pleated Media on Coalescence Filtration". University of Akron / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=akron1280828562.
Texto completoMailley, Domitille. "Fabrication of nanofibrous mats by "green" electrospinning for liquid microfiltration applications". Thesis, Strasbourg, 2018. http://www.theses.fr/2018STRAE019.
Texto completoThe fabrication of nanofibrous mats by an environmentally friendly, or in other words by a “green”, electrospinning process is nowadays a challenge. Electrospinning is a process allowing the fabrication, generally from a polymer solution, of nonwoven mats composed of fibers having diameters ranging between 50 nm and a few micrometers. Two new strategies have been developed to answer such a growing need. The first one consists in electrospinning bio-sourced polymers while the second one is based on the electrospinning of aqueous solutions exclusively. This second strategy allows avoiding toxic vapors coming from the evaporation of toxic solvents often used during the process. In this context, mats were electrospun from solutions composed of aqueous suspensions of water insoluble polymers, on one hand, and composed of tannic acid, a non-polymeric bio-based molecule exploiting supramolecular interactions. These new environmentally friendly strategies turn the electrospinning process in a less dangerous and less expensive one, and, as a result, ease the use of multi-jet setups and enable a better industrialization of the electrospinning process. Membranes have been developed for liquid microfiltration applications. As a matter of fact, electrospinning membranes can combine submicron pore sizes with porosities greater than 80% unlike commercial microfiltration membranes (porosity < 40%). The fabrication of liquid filtration membranes by a multi-jet "green" electrospinning process, thus, makes it possible to increase the production rates of electrospinning mats and filtration rates while respecting the environment
Costa, Elisabete Fernandez Reia Da. "Liquid moulding of carbon nanoparticle filled composites". Thesis, Cranfield University, 2011. http://dspace.lib.cranfield.ac.uk/handle/1826/7276.
Texto completoMcRorie, Aaron. "Bold and Small: Using Nanotechnology for Magnetic Filtration of an Inorganic Pigment Liquid Slurry". Kansas State University, 2018. http://hdl.handle.net/2097/38784.
Texto completoDepartment of Chemical Engineering
James H. Edgar
I am a current employee for a chemical company that makes complex inorganic color pigments for a variety of uses. Some of the applications require iron as a base for a black color variant; but several require a purity level that precludes iron. One such product that cannot have iron in it is a computer based application that requires absolute purity of only the copper-chrome based powder with no impurities. This color is a powder that is primarily composed of copper and chrome and has the distinct advantage that it has little-to-no magnetic susceptibility. This makes it ideal for mixing with a form of acrylic for coating circuit boards and other computer applications as a magnetic field could severely damage circuits. Unfortunately, the presence of impurities (particularly ferromagnetic iron) can increase the magnetic susceptibility of the powder. We are here to discuss the search for a system to filter out such impurities.
Corsetti, Stella. "Optical and spectroscopic analysis of phase transitions in the bulk and aerosols of liquid hydrocarbon fuels and their ethanol blends". Thesis, University of Aberdeen, 2016. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=230611.
Texto completoHuang, Kaiwu. "Surface Forces in Thin Liquid Films". Diss., Virginia Tech, 2020. http://hdl.handle.net/10919/104111.
Texto completoDoctor of Philosophy
When two macroscopic surfaces in water are brought to a close proximity, a thin liquid film (TLF) is formed in between, with its stability being determined by the surface forces present in the film. TLFs are ubiquitous in daily lives and play a decisive role in many industrial processes such as mineral flotation, food processing, oil extraction, heat transfer, etc. In the present work, the surface forces present in wetting films have been measured by approaching an air bubble (or an oil drop) slowly toward a flat surface while monitoring the curvature changes during film thinning by interferometry and calculating the capillary forces using the Young-Laplace equations. By analyzing the results in view of the Frumkin-Derjaguin isotherm and the extended DLVO theory, it was possible to determine the changes in the van der Waals, electrical double-layer (EDL), and hydrophobic forces during film thinning. The results show that both the EDL and the long-range component of the hydrophobic force control the kinetics of film thinning and rupture while the contact angle formation is controlled by the van der Waals force and the short-range hydrophobic force. It has been found also that n-alkane drops form substantially larger contact angles than air bubbles on a hydrophobic surface due to the fact that the van der Waals force is attractive in the drop-surface interactions while the same is repulsive in the bubble-surface interactions. These observations have a profound implication in flotation, that is, oil drops can recover hydrophobic particles from an aqueous phase better than air bubbles.
Freire, Sandra Maria Semedo Carvalho. "Characterization of water-soluble organic matter from urban aerosols". Doctoral thesis, Universidade de Aveiro, 2014. http://hdl.handle.net/10773/13111.
Texto completoWater-soluble organic matter (WSOM) from atmospheric particles comprises a complex array of molecular structures that play an important role on the physic-chemical properties of atmospheric particles and, therefore, are linked to several global-relevant atmospheric processes which impact the climate and public health. Due to the large variety of sources and formation processes, adequate knowledge on WSOM composition and its effects on the properties of atmospheric aerosol are still limited. Therefore, this thesis aims at providing new insights on the molecular composition of WSOM from fine atmospheric aerosols typical of an urban area (Aveiro, Portugal). In a first step, adsorption phenomena of semivolatile organic compounds on quartz fibre filters employed in the collection of atmospheric aerosols were assessed. Afterwards, atmospheric aerosol samples were collected during fifteen months, on a weekly basis. A mass balance of aerosol samples was performed in order to set the relative contribution of elemental carbon, WSOM and water-insoluble organic matter to the aerosol mass collected at the urban area of Aveiro, with a special focus on the assessment of the influence of different meteorological conditions. In order to assess the chemical complexity of the WSOM from urban aerosols, their structural characteristics were studied by means of Fourier transform infrared infrared - Attenuated Total Reflectance (FTIR-ATR) and solid-state cross polarization with magic angle spinning 13C nuclear magnetic resonance (CPMAS 13C NMR) spectroscopies, as well as their elemental composition. The structural characterization of aerosol WSOM samples collected in the urban area highlighted a highly complex mixture of functional groups. It was concluded that aliphatic and aromatic structures, hydroxyl groups and carboxyl groups are characteristic to all samples. The semi-quantitative assessment of the CPMAS 13C NMR data showed different distributions of the various functional groups between the aerosol samples collected at different seasons. Moreover, the presence of signals typical of lignin-derived structures in both CPMAS 13C NMR and FTIR-ATR spectra of the WSOM samples from the colder seasons, highlights the major contribution of biomass burning processes in domestic fireplaces, during low temperature conditions, into the bulk chemical properties of WSOM from urban aerosols. A comprehensive two-dimensional liquid chromatography (LC x LC) method, on-line coupled to a diode array, fluorescence, and evaporative light scattering detectors, was employed for resolving the chemical heterogeneity of the aerosol WSOM samples and, simultaneously, to map the hydrophobicity versus the molecular weight distribution of the samples. The LC x LC method employed a mixed-mode hydrophilic interaction column operating under aqueous reversed phase mode in the first dimension, and a size-exclusion column in the second dimension, which was found to be useful for separating the aerosol WSOM samples into various fractions with distinct molecular weight and hydrophobic features. The estimative of the average molecular weight (Mw) distribution of the urban aerosol WSOM samples ranged from 48 to 942 Da and from 45 to 1241 Da in terms of UV absorption and fluorescence detection, respectively. Findings suggest that smaller Mw group fractions seem to be related to a more hydrophobic nature.
A matéria orgânica solúvel em água (MOSA) de aerossóis atmosféricos é composta por um conjunto complexo de estruturas moleculares que influenciam as propriedades físico-químicas das partículas atmosféricas e, por conseguinte, desempenham um importante papel em diversos processos atmosféricos globalmente relevantes, afectando o clima e a saúde pública. Devido a uma ampla variedade de fontes e processos de formação, é ainda escasso o conhecimento acerca da composição estrutural da MOSA e do respectivo efeito nas propriedades dos aerossóis atmosféricos. Assim, esta tese pretende fornecer novas perspetivas sobre a composição molecular da MOSA presente na fracção fina de partículas atmosféricas características de uma área urbana (Aveiro, Portugal). Para o efeito, numa primeira fase do trabalho, foi avaliada a ocorrência de eventuais fenómenos de adsorção de compostos orgânicos semi-voláteis nos filtros de fibra de quartzo utilizados na colheita das amostras de partículas atmosféricas. Posteriormente, e na mesma área urbana, foi efectuada a colheita de amostras de aerossóis atmosféricos, durante um período de 15 meses, numa base de amostragem semanal e em contínuo. Foram efectuados balanços mássicos que permitiram descrever a importância das fracções de carbono elementar, MOSA e matéria orgânica insolúvel em água, na massa total de aerossóis atmosféricos recolhidos na zona urbana de Aveiro, tendo-se dado especial relevo ao estudo dos efeitos de diferentes condições meteorológicas. Na tentativa de entender a complexidade da MOSA de aerossóis urbanos, foram efectuados estudos de caracterização estrutural com recurso às espectroscopias de infravermelho com transformadas de Fourier (FTIR) acoplada a um sistema de reflectância total atenuada (ATR, sigla inglesa de Attenuated Total Reflectance) (FTIR-ATR) e de ressonância magnética nuclear de 13C com polarização cruzada (CP, sigla inglesa de Cross Polarization) e rotação em torno do ângulo mágico (MAS, sigla inglesa de Magic Angle Spinning) (RMN CPMAS de 13C) de estado sólido, mas também através da avaliação da respectiva composição elementar. A caracterização estrutural da MOSA dos aerossóis recolhidos na zona urbana confirmou o carácter heterogéneo deste tipo de matéria orgânica, traduzido por uma multiplicidade de grupos funcionais. De um modo geral, foi possível concluir que as estruturas alifáticas, as estruturas aromáticas, os grupos hidroxilo e os grupos carboxilo constituem funcionalidades comuns às amostras estudadas. A avaliação semi-quantitativa dos dados de RMN CPMAS de 13C mostrou igualmente diferentes distribuições dos diversos grupos funcionais, entre as amostras de aerossóis colhidos em diferentes períodos sazonais. A presença de sinais típicos de estruturas derivadas de lignina nos espectros de RMN CPMAS de 13C e FTIR-ATR das amostras de MOSA típicas de estações sazonais mais frias sugere que as propriedades de MOSA de partículas atmosféricas são influenciadas pelos processos de queima da madeira para aquecimento doméstico. Complementarmente às técnicas espectroscópicas anteriormente referidas, foi também utilizada a técnica de cromatografia líquida bidimensional abrangente (LC x LC) acoplada aos detectors de fotodíodos, fluorescência e evaporativo com dispersão de luz, com o objectivo de resolver a heterogeneidade das amostras de MOSA e, simultaneamente, mapear a hidrofobicidade versus distribuição de tamanhos moleculares das amostras. A utilização de uma coluna de cromatografia de interacção hidrofílica operada sob condições de fase reversa na primeira dimensão e de uma coluna de cromatografia de exclusão por tamanhos na segunda dimensão, revelou-se muito útil para a separação das amostras de MOSA em frações com hidrofobicidades e tamanhos moleculares distintos. A distribuição de massa molar média (Mw) obtida neste estudo variou entre 48 e 942 Da e 45 a 1241 Da, em termos de detecção por UV e fluorescência, respectivamente. Os resultados obtidos sugerem ainda que as fracções com menor valor de Mw tendem a ter um carácter relativamente mais hidrofóbico.
Kulkarni, Prashant S. "Mixed Hydrophilic/Hydrophobic Fiber Media for Liquid-Liquid Coalescence". University of Akron / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=akron1310686055.
Texto completoChakrabarty, Chitra L. "Figures of merit for a direct injection nebulizer for flow injection analysis and liquid chromatography with inductively coupled plasma spectrometric detection". Virtual Press, 1990. http://liblink.bsu.edu/uhtbin/catkey/722785.
Texto completoDepartment of Chemistry
Secondo, Lynn E. "Toxicological Inhalation Effects of Metal-Based Nanoparticle Aerosols as Studied by a Portable In Vitro Exposure Cassette". VCU Scholars Compass, 2018. https://scholarscompass.vcu.edu/etd/5705.
Texto completoRosa, Paula de Freitas. "Avaliação dos efeitos de suspensões de nanopartículas de prata (AgNP) na erradicação de bactérias e fungos encontrados em material particulado". Universidade Federal de São Carlos, 2014. https://repositorio.ufscar.br/handle/ufscar/4132.
Texto completoUniversidade Federal de Sao Carlos
The monitoring of indoor air quality (QIA) is a subject that has been disseminated in the current research. The objectives of them are the development of common methodologies to identify possible pollution agents at different locations. However, there are few works that develop methodologies in an attempt to mitigate the effects of indoor air pollution. Based on this problem, this study aimed to evaluate the effectiveness of filters doped with silver nanoparticles in the elimination of bacteria and fungi (bioaerosols) present in particulate matter from indoor environments, since it is known that nanosized silver particles have pronounced bactericidal and fungicidal effect. To achieve these goals, fabrics considered common were initially acquired in malls and were evaluated in terms of their filtration properties (permeability, loss, collection efficiency). It was subsequently performed the synthesis of silver nanoparticles suspension followed by immersion in the suspension of the chosen fabric. After drying, they were used to collect air suspended particulate material in a bathroom of the Department of Chemical Engineering of the Federal University of São Carlos. From the results it was verified that the filters doped with silver nanoparticles were able to significantly eradicate microorganisms present in air suspended particulate material. The elimination of microorganisms ranged from 22 to 82% for the mesh PV and 71 to 100% for the cotton fabric.
O monitoramento da qualidade de ar interno (QAI) é um assunto que vem se difundindo nas pesquisas atuais. Os objetivos destas pesquisas comumente são o desenvolvimento de metodologias para identificar possíveis fontes de poluição em diferentes locais. Entretanto, poucos são os estudos que abordam o desenvolvimento de metodologias que tentam amenizar os efeitos da poluição em ambientes fechados. Com base nesta problemática, este trabalho teve como objetivo avaliar a eficácia de filtros impregnados com nanopartículas de prata na eliminação de bactérias e fungos (bioaerossóis) presentes no material particulado de ambientes internos, uma vez que se sabe que partículas nanométricas de prata possuem pronunciado efeito bactericida e fungicida. Para alcançar este objetivo foram adquiridos em centros comerciais tecidos considerados comuns e estes foram avaliados em termos de suas propriedades de filtração (permeabilidade, perda de carga, eficiência de coleta), e posteriormente foram realizadas as sínteses de nanopartículas de prata seguidas da imersão em suspensão de nanopartícula dos filtros escolhidos. Após a secagem dos mesmos foi realizada a coleta do material particulado a qual foi feita em um banheiro do Departamento de Engenharia Química da Universidade Federal de São Carlos. Através dos resultados foi possível verificar que os filtros impregnados com nanopartículas de prata foram capazes de erradicar micro-organismos presentes no material particulado de forma significativa. A eliminação dos micro-organismos variou de 22 a 82% para o tecido malha PV e de 71 a 100% para o tecido algodão.
Berkemeier, Thomas [Verfasser]. "Multiphase kinetics of molecular diffusion, phase transitions and chemical reactions in liquid, semi-solid and glassy organic aerosols / Thomas Berkemeier". Mainz : Universitätsbibliothek Mainz, 2016. http://d-nb.info/110977527X/34.
Texto completoMurray-Chiasson, Audrey. "Étude de la relâche des inclusions lors de la filtration de l'aluminium liquide /". Thèse, Chicoutimi : Université du Québec à Chicoutimi, 2002. http://theses.uqac.ca.
Texto completoThieffry, Guillemette. "Procédé alternatif pour l’épuration des fumées de hauts fourneaux". Thesis, Université de Lorraine, 2018. http://www.theses.fr/2018LORR0288/document.
Texto completoIn order to enable the establishment of a CO2 recovery chain sector from the steel industry, this study aims to propose a new filtration device for the dust removal of blast furnace fumes that would be placed after the current treatment chain to improve their purification. The originality of the chosen technology, a trickle bed, permits to maintain a constant pressure drop by re-entraining continuously the particles trapped on collectors thanks to a water film flow to overcome the clogging problem. A hydrodynamic study and efficiency measurements lead with particles (in a range of diameters between 0.5 and 10 μm) showed that the pressure drop and the initial efficiency increase with the decrease of the collector diameter, which is in agreement with the results of the literature for dry granular beds. The presence of water increases the initial collection efficiency at the expense of a higher pressure drop. These observations are related to the decrease of the bed porosity in presence of a water flow. A good compromise between pressure drop and efficiency was found for an air flow rate of 20 m3.h-1, a liquid flow rate of 12 L.min-1 and using a 50 cm bed composed of glass beads of 5 mm diameter. Long-term clogging tests showed that the efficiency of the bed remains globally constant over time at a value close to the initial one. The pressure drop, although higher at the beginning of the experiment than that of a dry granular bed, stabilizes rapidly at a much lower value than that measured for a dry granular bed for the same mass of particles collected. The experiments have been carried out over 30 h under disadvantageous conditions, and we can expect that under real operating conditions the pressure drop will be stable over much longer times. Thus, the presence of water plays its part by limiting the clogging evolution of the granular bed by the re-entrainment of particles collected by the bed. This study was completed by the development of a model to determine the pressure drop and initial efficiency of a trickle bed, which resulted in an example of pre-sizing of a process on an industrial scale
Olanrewaju, Babajide O. "Non-thermal processes on ice and liquid micro-jet surfaces". Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/39475.
Texto completoAvery, Thomas W. "Further characterization of the direct injection nebulizer for flow injection analysis and liquid chromatography with inductively coupled plasma spectrometric detection". Virtual Press, 1988. http://liblink.bsu.edu/uhtbin/catkey/539620.
Texto completoDepartment of Chemistry
Erasmus, Mothobi. "Leaching of nickel laterite with a solution of ammonia and ammonium carbonate utilizing solids liquid separation under pressure". Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/20091.
Texto completoAFRIKAANSE OPSOMMING: Logingstoetse van saprolitiese lateriet met 'n oplossing van ammonia en ammonium karbonaat is gedoen in 'n druk houer. Die logingsvat vir hierdie studie is ontwikkel om die loging sowel as die vloeistof – vastestof skeiding te doen. Gesinterde metaal filter medium was gebruik vir die vloeistof – vastestof skeiding aangesien dit die volgende eienskappe vertoon; die vermoë om druk te weerstaan, die chemiese weerstand teen bytsoda oplossing, asook voordelige terugspoel eienskappe. Optimum loogkondisies is bepaal deur die temperatuur, ammoniak konsentrasie, ammonium karbonaat konsentrasie, en suurstof druk te varieer. Na loging en filtrasie is die pH van die loogvloeistof gemeet en monsters is deur atoom absorpsie spektrofotometrie geanaliseer vir opgeloste metale (Ni, Fe en Co). Die veranderlike wat die grootste effek op die loging van nikkel gehad het was die ammoniak konsentrasie. Die maksimum herwinning van nikkel van uit ongeroosterde erts was 11.9 % by 4 M NH3, 100 oC, 2 M (NH4)2CO3 en 2 bar O2 druk. Optimisering van die loogdata is gedoen deur die respons profiel te analiseer met Statistica sagteware. Optimum loogkondisies was bepaal as 3 M NH3, 2 M (NH4)2CO2, 100 oC en 2 bar O2 druk. Die mineralogie van die erts voor en na loging is bestudeer om te bepaal waarom die nikel opbrengs van ongeroosterde erts so laag was. XRF analise van die vastestof na loging het gewys dat yster, silikon en magnesium nie deur loging affekteer is nie. Slegs nikkel het 'n merkwaardige afname getoon. XRD analsiese van die vastestof voor en na loging wys dat die meeste mineraal fases teenwoordig in die erts nie deur die loogoplossing affekteer is nie. SEM met EDS deteksie is gebruik om die nikkel verspreiding in die erts te bepaal. Die resultate wys dat nikkel meestal met yster assosieer. Die yster is omring deur magnesium en silikon. Silikaat minerale reageer nie met ammoniak en ammonium karbonaat oplossing nie. In filtrasie eksperimente is daar gevind dat die filtrasie differensiële druk geen noemenswaardige effek op die filtrasie tempo gehad het nie. Die gemiddelde filtrasietempo was 0.29+0.07 ml/min.cm2. Die filtrasie tempo van hierdie eksperimente was baie laag, hoofsaaklik as gevolg van blokkasie van porieë van die sinter metaal filter medium. Dit is gevind dat blokkasie van porieë hoofsaaklik op die oppervlak van die filter medium plaasvind. Lateriedes toon 'n lae deurlaatbaarheid as gevolg van die erts se hoë klei inhoud. Rheologiese studies op hierdie erts wys dat die erts skuif verdikking (“shear thickening”) gedrag vertoon. 'n Baie helder filtraat is egter verkry. Die gesinterde metale is na elke loog en filtrasie eksperiment skoongemaak deur terugspoeling met water en lug. Hierdie procedure was suksesvol, aangesien al 18 eksperimente met dieselfde filter medium uitgevoer is. Die effek van erts roostering voor loging is ondersoek by die optimum kondisies wat verkry was vir die loging van ongeroosterde erts. Nikkel ekstraksie het effens verbeter met geroosterde erts. Die gemiddelde persentasie ekstraksie van nikkel van drie eksperimentele lopies was 19.25 % + 0.19 by 100 oC, 3 M NH3, 2 M (NH4)2CO3, en 5 bar suurstofdruk. 'n Gedeelte van die nikkel in die erts was onherwinbaar as gevolg van die assosiasie van nikkel met her-gekristaliseerde sillikaat-minerale in die gereduseerde erts. Die porositeit van die erts is verbeter deur dit te rooster. Die filtrasie tempo het merkwaardig verbeter nadat die erts gerooster is. Die gemiddelde filtrasie tempo was 2.6+0.05 ml/min.cm2. Kinetika vir die oplossing van ongeroosterde en geroosterde saprolitiese lateriet is ondersoek, met in ag geneem die effekte van temperatuur, ammonia konsentrasie, ammonium karbonaat konsentrasie en suurstofdruk. Vir ongeroosterde erts is gevind dat die oplossingstempo en graad van nikkel ekstraksie toeneem met toenemende temperatuur. Toename in ammoniak konsentrasie lei tot 'n toename in nikkel ekstraksie, maar nikkel ekstraksie is nie alleenlik afhanklik van ammoniak nie. 'n Toename in ammonium karbonaat konsentrasie lei ook tot 'n toename in nikkel ekstraksie. Ammonium karbonaat is krities vir die ekstraksie, aangesien ammonium ione in die oplossing die hidrolise van die nikkel-amien kompleks verhoed. Suurstof het nie 'n merkwaardige effek op die totale nikkel ekstraksie gehad nie. Vir die bepaling van reaksie kinetika is 100˚C gebruik as die logingstemperatuur. Die loging van saprolitiese nikkel lateriet vind in twee stadia plaas. In die eerste fase is die oplossing van nikkel vinnig, maar na 15 minute neem die reaksietempo af. Die reaksietempo word verlaag deur inerte minerale wat teenwoordig is in die nikkel erts. Hierdie minerale bevat yster, magnesium en silikon. Die vinnige oplossing van nikkel in die eerste fase verteenwoordig die loging van vry nikkel in die erts. Die data vir die tweede stadium is geanaliseer deur die krimpende kern model, en die resultate dui aan dat die oplossingstempo deur 'n gemengde meganisme beheer word (as laag diffusie en oppervlak reaksie beheer). Die aktiveringsengergie vir die oplossingsreaksie was bereken as 56.5 kJ/mol. Die reaksieorde ten opsigte van ammoniak en ammonium karbonaat is onderskeidelik bepaal as 0.3 en 0.26. Die hoogste graad van nikkel ekstraksie vir die geroosterde erts is verkry by 60oC, 3 M NH3, 2 M (NH4)2CO3, en 5 bar O2 druk. Die persentasie ekstraksie by hierdie kondisies was 28.7 %. Temperatuur het nie 'n merkwaardige effek op loogtempo gehad nie. 'n Toename in NH3 en (NH4)2CO3 het die graad van nikkel ekstraksie laat toeneem, maar het nie enige effek op die loogtempo gehad nie. In die afwesigheid van ammonium karbonaat het byna geen nikkel ekstraksie plaasgevind nie. Die eksperimentele data het nie 'n lineêre passing vir die krimpende kern model soos vir die ongeroosterde erts ondersoek gegee nie. Die rede hiervoor is dat die monsternemings interval te groot was, of dat die logings karakteristiek van geroosterde nikel gekompliseerd is en nie alleen deur die krimpende kern model voorspel kan word nie. Logings eksperimente wys dat die temperatuur hoog moet wees (> 100 oC) om 'n hoë graad van nikkel ekstraksie te verkry met die ongeroosterde erts. 'n Geslote reaktor word benodig om by 'n hoë temperatuur met ammoniak en ammonium karbonaat te loog om reagens verliese te verhoed. Die reaksie kinetika word grootliks deur aslaag diffusie beheer. Hieruit kan gesien word dat 'n lae graad van nikkel ekstraksie uit die ongeroosterde saprolitiese lateriet die gevolg is van nie-reaktiewe minerale (aslaag) waarin die nikkel binne die erts bevat word. Om 'n hoë graad van nikkel ekstraksie te verkry moet die erts onder reduserende kondisies gerooster word. Rooster kondisies moet versigtig beheer word om hoë oplossing van nikkel te verseker. Optimum rooster kondisies om maksimum nikkel oplossing te verkry, moet bepaal word voordat daar met groter hoeveelhede erts gewerk kan word.
Yeates, Charl Alan. "Optimisation of a stereoconvergent process catalysed by whole yeast cells / Charl Alan Yeates". Phd thesis, North-West University, 2008. http://hdl.handle.net/10394/4100.
Texto completoPeña, Gomez Natalie. "Development of polymeric and silica filtering materials functionalized with antimicrobial compounds for the elimination of microorganisms in liquid food". Doctoral thesis, Universitat Politècnica de València, 2020. http://hdl.handle.net/10251/137041.
Texto completo[CAT] En la present tesi doctoral s'ha avaluat l'ús de nous suports cel·lulòsics i silicis com a sistemes de filtració per a l'estabilització i conservació d'aliments líquids, amb la finalitat d'afrontar dos grans reptes de la indústria de begudes. D'una banda, evitar o minimitzar els canvis en les propietats nutricionals, estructurals i organolèptiques dels aliments, ocasionats per la pasteurització tèrmica tradicional, i oferir una alternativa al problema de la baixa viabilitat deguda als alts costos d'inversió/producció en aplicar noves tecnologies no tèrmiques. Per això, aquesta tesi doctoral es centra en el desenvolupament i avaluació d'una nova tecnologia no tèrmica de conservació d'aliments líquids basada en la filtració. S'han desenvolupat sistemes de filtració a partir de suports cel·lulòsics i silicis, sense funcionalitzar o funcionalitzats amb compostos antimicrobians. En el primer capítol es va avaluar l'ús de materials de cel·lulosa com a suports filtrants per al tractament d'aliments líquids. Com a primera aproximació es va desenvolupar un material porós nano-micro tubular a partir de l'extracció i deslignificació del material cel·lulòsic present en el cor o raquis de la panolla de dacsa. L'ús d'aquest suport va resultar ser efectiu com a material filtrant per al tractament d'aigua i suc de taronja, en un sistema de flux continu, eliminant la càrrega microbiana. L'aplicació d'aquest suport com a sistema de filtració presenta diversos avantatges com la seua capacitat de retenció microbiana, la reutilització de subproductes de la dacsa i, per tant, el seu respecte al medi ambient. No obstant això, seria necessari optimitzar el procés de filtrat per a evitar la freqüent obturació dels seus porus que va requerir diversos cicles de rentada durant el procés, així com establir un mètode de regeneració del material per a incrementar la seua vida útil. A més, aquest sistema va afectar el color del suc filtrat, que no es va mantenir constant durant el procés, la qual cosa suposa un important desavantatge que és necessari abordar. Com a segona aproximació, es va avaluar el potencial de la immobilització d'una molècula bioactiva sobre membranes de cel·lulosa, per a millorar la capacitat de retenció microbiana del material cel·lulòsic, així com permetre la seua reutilització. Els filtres de cel·lulosa funcionalitzats amb poliamines van demostrar ser eficaces en l'eliminació de patògens en aigua, a causa de les càrregues positives generades pels grups amina immobilitzats en la superfície de les membranes, que atrauen i retenen els bacteris carregats negativament. Donada la fàcil preparació i procediment d'ús de les membranes de cel·lulosa funcionalitzades amb poliamines, aquestes podrien ser considerades una bona opció per al desenvolupament de sistemes de tractament d'aigües in situ, ràpids, de fàcil maneig i de baix cost. El segon capítol descriu el desenvolupament i aplicació de partícules de sílice funcionalitzades amb compostos d'olis essencials, amb la finalitat de dissenyar coadjuvants de filtració amb activitat antimicrobiana. La filtració de diverses matrius alimentàries (aigua, cervesa i suc de poma) a través dels suports funcionalitzats amb els antimicrobians naturals va demostrar ser eficaç en la reducció del recompte del cep patogen Escherichia coli, així com enfront de la microflora endògena de la cervesa i el suc (bacteris àcid làctics, aerobis mesòfils, psicròfils, floridures i llevats). L'eficàcia en el control microbià es deu a la combinació de l'adsorció física i la inactivació per contacte amb els compostos d'olis essencials immobilitzats. A més, l'avaluació de les propietats fisicoquímiques i sensorials dels aliments líquids estudiats va demostrar un efecte poc significatiu, aquest depèn de la grandària de les partícules de sílice usades i de la molècula bioactiva immobilitzada. Per tant, el sistema de conserv
[EN] In the present doctoral thesis the use of new cellulosic and silica supports as filtering systems for the stabilization and preservation of liquid foods has been evaluated to overcome two major challenges of the beverage industry. On the one hand, avoid or minimize the changes in the nutritional, structural and organoleptic properties of food caused by traditional thermal pasteurization, and offer an alternative to the problem of low viability due to high investment/production costs when applying new non-thermal technologies. Therefore, this doctoral thesis focuses on the development and evaluation of a new non-thermal technology for the preservation of liquid foods based on filtration. The filtering systems have been developed from cellulosic and silica supports, non-modified or functionalized with antimicrobial compounds. In the first chapter, the use of cellulose materials as filtering supports for the treatment of liquid foods was evaluated. As first approximation, a porous nano-micro tubular material was developed from the extraction and delignification of the cellulosic material present in the corn stalk. The use of this support was effective as filtering material for the treatment of water and orange juice, in a continuous flow system, eliminating the microbial load. The application of this support as filtering system has several advantages, such as its microbial retention capacity, the reuse of corn by-products and, therefore, its respect for the environment. However, it would be necessary to optimize the filtering process to avoid the frequent clogging of its pores that required several washing cycles during the process, as well as to establish a method of material regeneration to increase its life. In addition, this system affected the color of the filtered juice, which did not remain constant during the process, representing an important disadvantage that must be addressed. As a second approach, the potential of the immobilization of a bioactive molecule on cellulose membranes was evaluated to improve the microbial retention capacity of the cellulosic material, as well as to allow its reuse. The cellulose filters functionalized with polyamines proved to be effective in eliminating pathogens in water, due to the positive charges generated by the amine groups immobilized on the surface of the membranes, which attract and retain the negatively charged bacteria. Given the easy preparation and usage of the polyamines-functionalized cellulose membranes, these could be considered a good option for the development of fast, easy to use and low cost in situ water treatment systems. The second chapter describes the development and application of silica particles functionalized with essential oil components to design filtering aids with antimicrobial activity. The filtration of various food matrices (water, beer and apple juice) through the supports functionalized with natural antimicrobials proved to be effective in reducing the load of the pathogenic strain Escherichia coli, as well as reducing the endogenous microflora of beer and the juice (lactic acid bacteria, mesophilic, psychrophilic, mold and yeast). The removal capability is due to the combination of physical adsorption and contact inactivation with the essential oil compounds immobilized. In addition, the evaluation of the physicochemical and sensory properties of the liquid foods studied showed a not significant effect, it depends on the size of the silica particles used and the immobilized bioactive molecule. Therefore, the proposed preservation system has a high potential for cold beverage pasteurization processes.
N. Peña-Gomez would like to thank for financial support in the frame of her PhD project to Operational Programme of the European Social Fund (ESF) 2014-2020, the Agencia Estatal de Investigación, Generalitat Valenciana and FEDER-EU (Projects RTI2018-101599-B-C21 and AGL2015-70235-C2-1-R). The authors also thank the Electronic Microscopy & Microanalysis Laboratory at Patras University for support.
Peña Gomez, N. (2020). Development of polymeric and silica filtering materials functionalized with antimicrobial compounds for the elimination of microorganisms in liquid food [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/137041
TESIS
Parente, Rafael Benevides. "Desenvolvimento de Reator Poroso de GaseificaÃÃo de Biomassa LÃquida por OxidaÃÃo Parcial Aplicado ao Glicerol". Universidade Federal do CearÃ, 2012. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=8032.
Texto completoA biomassa lÃquida residual de processos agrÃcolas e agroindustriais em geral representa um recurso renovÃvel em quantidade expressiva sem uma destinaÃÃo econÃmica e ambientalmente sustentÃvel Como exemplo a soluÃÃo quanto aos estoques de glicerina resultante da transesterificaÃÃo de Ãleos vegetais para obtenÃÃo do biodiesel tem sido postergada pela carÃncia de alternativas de engenharia apropriadas ao aproveitamento adequado dessa biomassa Por essa razÃo foi iniciado o desenvolvimento de um reator de gaseificaÃÃo destinado à biomassa lÃquida pela via da oxidaÃÃo parcial onde à empregada uma tecnologia de combustÃo nÃo convencional a CombustÃo de FiltraÃÃo como base de projeto para a concepÃÃo do reator em que a biomassa de referÃncia utilizada foi o glicerol (C3H8O3) Este trabalho eminentemente experimental foi realizado com a construÃÃo de um protÃtipo de reator de gaseificaÃÃo em escala de laboratÃrio em que seu queimador à preenchido completamente por esferas cerÃmicas de alumina (Al2O3) formando assim uma matriz porosa inerte que fica parcialmente imersa no glicerol na sua extremidade inferior e que envolve um trocador de calor instalado na parte superior do reator O processo à investigado no sentido de identificar algumas caracterÃsticas fundamentais de projeto tais como: limite de operaÃÃo do reator em termos de misturas arcombustÃvel; presenÃa de fenÃmenos de instabilidade; velocidade de propagaÃÃo da onda de combustÃo; e influÃncia dos principais parÃmetros de operaÃÃo, razÃo de equivalÃncia taxa de consumo de combustÃvel e vazÃes de ar e Ãgua na reaÃÃo Embora toda a experimentaÃÃo tenha se restringido a ensaiar o gaseificador para produÃÃo de gÃs de sÃntese pelo mÃtodo da oxidaÃÃo parcial a investigaÃÃo teÃrica foi mais abrangente englobando a reforma autotÃrmica Os experimentos respaldados por instrumentos de monitoramento e anÃlise cromatogrÃfica foram apoiados por um estudo teÃrico a partir de um modelo analÃtico simplificado com base na reaÃÃo global de oxidaÃÃo parcial associada à reaÃÃo de deslocamento ÃguaâgÃs Resultados experimentais demonstraram a viabilidade do processo constatando estabilidade operacional em ampla faixa de razÃo de equivalÃncia e eficiÃncia de conversÃo (>20%) do glicerol em gÃs de sÃntese mantendo extraÃÃo de energia da reaÃÃo
The residual liquid biomass from agricultural and agroindustrial processes in general way represents a renewable resource in significant amount without an economically and environmentally sustainable destination For instance the solution concerning glycerin stocks remaining from the vegetable oil transesterification for obtaining biodiesel has been postponed due to the lack of engineering alternatives appropriate to the proper utilization of this biomass Therefore the development of a liquid biomass gasification reactor based on partial oxidation has been initiated where a non conventional combustion technology has been employed Filtration Combustion as a design basis for the reactor conception in which the reference biomass used was glycerol This work eminently experimental was carried out to build a gasification reactor prototype in laboratory scale in which its burner is completely filled by ceramic spheres of alumina (Al2O3) thus forming a inert porous matrix which is partially immersed in glycerol at its bottom end and which involves a heat exchanger installed at the top of the reactor The process is investigated to identify some key design features such as: reactor operation limit in terms of fuel-air mixtures; occurrence of instability phenomena; combustion wave propagation velocity; and influence of the main operation parameters equivalence ratio fuel consumption rate and air and water flow rates into the reaction Although all experimentation has been restricted to test the gasifier for the production of synthesis gas by partial oxidation method theoretical investigation was broader comprising the autothermal reforming The experiments supported by monitoring instruments and chromatographic analysis were supported by a theoretical study based on a simplified analytical model considering the global reaction of partial oxidation associated with water-gas shift reaction Experimental results have demonstrated the feasibility of the process providing operational stability over a wide range of equivalence ratio and conversion efficiency (>20%) of glycerol to syngas while maintaining energy extraction from reaction
Dall'Ora, Lucia. "Characterization and modeling of organic solvents sorption and transport in PDMS membranes for organic/organic separations". Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017.
Buscar texto completoSteffens, Juliana. "Desempenho de filtros fibrosos operando na remoção de partículas nanométricas de aerossóis". Universidade Federal de São Carlos, 2007. https://repositorio.ufscar.br/handle/ufscar/3847.
Texto completoUniversidade Federal de Sao Carlos
The increase in the air pollution in the last decades is causing a strong increase in the monitoring and control of emissions of particulate matter in the atmosphere, in order to minimize the problems caused to the environment and to the human health. Particularly, the behavior nanometric particles in the air needs special attention. The fiber filters, one of the oldest methods of particle removal, are, in principle, capable to operate in this size range, but data on their performance are still scarce. In this work, the behavior of an industrial filter of polyester and of a high efficiency (HEPA) filter was studied with the intention of evaluating their performance operating in the removal of nanometric particles from aerosols. The polyester filter had a porosity of 0.884, a thickness of 4.5 mm and diameter of fiber of 16 m and the HEPA filter the porosity of 0.920, thickness of 0.4 mm and diameter of fibers between 0.075 and 2.35 µm. The test aerosol was composed by monodispersed NaCl particles, obtained from the Electrospray Aerosol Generator, model 3480, from TSI, using salt solutions in concentrations from 0.5 to 5.0 g/L. The size of the generated particles varied from 8.4 to 94.8 nm. To determine this diameter, images in an Electronic Transmission Microscope were obtained and analyzed in the image analyzer Image Pro Plus, 3.0. The filtration device was built in acrylic with a filtration area of 40 cm2. The performance of the filters was evaluated through the analysis of the collection efficiency of the nanometric particles, by counting the particles before and after the filter, using a TSI Condensation Nuclei Particle Counter , model 3007. The filter of polyester showed a maximum collection efficiency of 0.990. The HEPA filter demonstrated its capacity to collect particles in this size range, obtaining larger efficiencies than 0.99994. The increase of the filtration velocity, as well as the increase of the diameter of the particles resulted in smaller efficiencies in both filters, typical behavior of filters operating in the range of predominance of the diffusional mechanism. When compared to theoretical models form the literature, it was verified poor fitting. Therefore, it is suggested an adjustment to the LIU and RUBOW (1990) model, and an effective increase in the mechanism of direct interception caused by the Brownian motion was introduced. In the case of the HEPA filters, considering the observed discrepancy between theory and experiment, an approach that took into account the fiber size distribution of the filter was proposed. In both cases a sensitive improvement was verified in the adjustment of the theoretical prediction to the experimental data
A crescente escalada da poluição do ar nas últimas décadas vem causando um sensível aumento no monitoramento e no controle de emissões de material particulado na atmosfera, visando minimizar os problemas causados ao meio ambiente e à saúde humana. Particularmente, o comportamento de partículas nanométricas no ar necessita atenção especial. Os filtros de fibras, um dos métodos mais antigos de remoção de material particulado, são, em princípio, capazes de atuar nessa faixa de tamanho, mas dados sobre seu desempenho são ainda escassos. Neste trabalho estudou-se o comportamento de um filtro industrial de poliéster e de um filtro de alta eficiência (HEPA) com o intuito de avaliar o desempenho dos mesmos operando na remoção de partículas nanométricas de aerossóis. O filtro de poliéster tinha porosidade de 0,884, espessura de 4,5 mm e diâmetro de fibra de 16µm e o filtro HEPA uma porosidade de 0,920, espessura de 0,4 mm e diâmetro de fibras entre 0,075 e 2,35 µm. O aerossol de teste era composto por partículas monodispersas de NaCl, que foram obtidas a partir de um gerador de partículas Electrospray Aerosol Generator, modelo 3480, da TSI, utilizando soluções de sal nas concentrações de 0,5 a 5,0 g/L. O tamanho das partículas geradas variou de 8,4 a 94,8 nm. Para determinar este diâmetro foram obtidas imagens do Microscópio Eletrônico de Transmissão e analisadas no Programa Image Pro Plus, 3.0. O dispositivo de filtração foi construído em acrílico com área de filtração de 40 cm2. O desempenho dos filtros foi avaliado através da análise da eficiência de remoção das partículas nanométricas, através da contagem de partículas, utilizando um contador de partículas, da TSI, modelo 3007. O filtro de poliéster apresentou eficiência de coleta máxima de 0,990. O filtro HEPA demonstrou possui uma grande capacidade de coletar partículas nesta faixa de tamanho, obtendo eficiências maiores que 0,99994. O aumento da velocidade de filtração, bem como o aumento do diâmetro das partículas proporcionou queda na eficiência em ambos os filtros, comportamento típico de filtros operando na região de predominância do mecanismo difusional. Quando avaliados os modelos presentes na literatura, verificou-se que os mesmos não se ajustaram aos dados experimentais. Portanto, propôs-se um ajuste ao modelo de LIU & RUBOW (1990), considerando um aumento efetivo no mecanismo de interceptação direta causado pelo movimento Browniano. No caso dos filtros HEPA, frente à observada discrepância entre teoria e experimentos, foi proposto um equacionamento que levou em conta a distribuição de tamanho das fibras do filtro. Em ambos os casos verificou-se uma sensível melhora no ajuste da previsão teórica aos dados experimentais
Xiang, Maiqi. "Aerosol sampling and characterization technique using TEM porous grids". Thesis, Compiègne, 2021. http://www.theses.fr/2021COMP2611.
Texto completoCharacterization and analysis of airborne solid nano/micrometric particles have received considerable attention. The representative collection of particles to be analyzed is a fundamental requirement. The recently developed aerosol sampler called Mini Particle Sampler (MPS), which is equipped with a porous Transmission Electron Microscopy (TEM) grid, renders particle sampling convenient. However, the research for this useful sampling system is still in the initial stage. The thesis improves and quantifies the MPS sampling system. Besides, a new method of pollutant mass characterization is developed based on the optimizedsampling system. The sampling efficiency of the sampling system for particles with mobility diameters ranging from 5 to 100 nm is mainly investigated. According to the sensitivity analysis tof the parameters in the whole setup carried out by the Taguchi method, salt concentration of the atomizer, high-voltage polarity in the Differential Mobility Analyzer (DMA), sampling efficiency assessment method, sampling temperature, and porosity of the porous TEM gridminimally affect the collection efficiency. Small filter pore size, high flowrate, and denserparticles promote particle capturing, which are the main parameters. Based on the investigation of the filtration mechanisms of TEM grids and the comparison of available theoretical models, a method for experimental collection efficiency analysis combined with theoretical modeling is developed by considering the model’s applicability. Using this method, the effects of the main parameters mentioned above are compared between experiments andtheories. The sampling technology is optimized and the minimum collection efficiency isup to 40% by adjusting the parameter settings of the sampling system. In addition, accordingto the Monte-Carlo methods, sampling efficiency uncertainties from measured data andtheoretical models are generally less than 1% and 9%, respectively. Most sampling efficienciesmeasured data are covered by the efficiency uncertainty range simulated by models.Sobol variance-based sensitivity analysis shows that pore size and flowrate contribute significantly to the uncertainties, and require control to improve the efficiency precision. Besides, Cunningham correction factor is also a sensitivity parameter. Based on the above development of the MPS sampling system, a quantitative method is proposed to characterize the elemental mass concentration of airborne nano/micrometric particles via particle sampling and TEM - Energy Dispersive X-ray Spectroscopy (EDS). The principle is to collect airborne particles on a TEM grid, then add a certain mass of reference particles on it, and determine the relative percentages of all elements (reference and unknown particles) via EDS. Regardless of the sampling condition, the quantitative and homogeneously collection of monodisperse RbCl, CsCl, NaCl particles on the TEM grid could be achieved. For all the tested conditions, when depositing divers kinds of quantified airborne particles on one TEM grid, the absolute deviations between theoretical element mass percentages and experimental ratios measured by EDS remain lower than 10%, which confirms that the proposed method could be used for mass characterization of elements in an unknown aerosol. RbCl has been preferred as a reference since its rarity in usual airborne particles and having a low toxicity. The developed method has been used for characterizing aerosol released by the friction between serial pad and braking disc. The mass concentration of Fe in the braking aerosol is calculated as 0.105 μg/L using this method, which is consistent with the concentration range estimated from the data of Scanning Mobility Particle Sizer (SMPS) and Aerodynamic Particle Sizer (APS)
Haupt, Petronella. "Effective solvent extraction of coal and subsequent separation processes". Diss., Pretoria : [s.n.], 2006. http://upetd.up.ac.za/thesis/available/etd-08282007-113611.
Texto completoAccompanied by a CD-ROM containing Matlab programs. Includes bibliographical references. Available on the Internet via the World Wide Web.
Luecke, Steven T. "Performance verification of personal aerosol sampling devices". [Tampa, Fla.] : University of South Florida, 2003. http://purl.fcla.edu/fcla/etd/SFE0000182.
Texto completoБанахевич, Р. Ю. "Розроблення методу діагностування скупчень у порожнинах лінійної частини магістральних газопроводів". Thesis, Івано-Франківський національний технічний університет нафти і газу, 2015. http://elar.nung.edu.ua/handle/123456789/4723.
Texto completoПриведены результаты анализа современного состояния и тенденций развития отечественных и зарубежных достижений по исследуемой проблеме, который позволил определить направления дальнейших исследований. Выполнен анализ причин образования скоплений в полостях газопроводов, исследованы факторы и причины образования гидратных образований в полостях труб при магистральном транспорте газа. Исследовано влияние скоплений на безопасность и режимы эксплуатации газопроводов. Идентифицированы места наиболее вероятного появления скоплений . Проведены экспериментальные исследования с целью установления оптимальных информативных параметров обнаружения гидратных образований в полостях магистральных газопроводов. Разработан опытно-экспериментальный образец прибора для контроля наличия скоплений в полостях линейной части магистральных газопроводов.
The aim of the thesis is to solve the current problem of applied scientific research in the direction of improving methods of exploitation of main gas pipelines through the development and introduction of new methods and means of technical diagnostics clusters in the cavities of the linear part of main gas pipelines. The results of a current state analysis and domestic and foreign developments trends of the researching problem, that allowed to define further research areas. The object of the research is the presence of a main gas pipeline liquid clusters. The subject of research is the methods and means of diagnosing fluid in main gas pipelines. The causes of clusters in the gas pipelines cavities were analyzed, the factors and causes of hydrate formation in the pipes cavities have been investigated at the main gas transport. Provisions are made for protection: the method of determining the location and level of liquids and dirt in the cavity of main gas pipeline. To solve the problems and achieve the goal of a thesis uses methods of analytical modeling, correlation and regression analysis, interpolation data. Experimental study on developing a method of diagnosing clusters in the cavities of the linear part of main gas pipelines and generalization of results were carried out using the theory and practice of technical measurements and experimental design, methods of polynomial filtering of measurement results of mathematical statistics and probability theory, methods of numerical processing of the experimental results to enhance their credibility. Scientific novelty of the results of the thesis by the following provisions: 1. The first time the analytical method for determining the location and volume of fluid accumulation in the cavity of main gas pipelines. 2. For the first time developed a method of technical diagnostics of gas mains pipe cavity without interference in its work and violations of pumping gas is to use ultrasonic method of determining the level of liquid in place of its accumulation in the cavity of the pipe. 3. Improved functional diagram ultrasonic method of technical diagnostics linear part of main gas pipelines, which enabled regardless of environmental conditions, to obtain reliable information on the state of the pipeline. 4. Found a further development of methods of construction and use of technical equipment and diagnostic systems for the evaluation of the technical state of gas mains, which significantly increases the reliability of the transmission system. Solved in dissertation work tasks and the results obtained enable to increase the efficiency and reliability of gas transportation system by applying the proposed method of diagnosing fluid accumulations for their effective withdrawal from the cavities of gas mains pipes for further implementation of in qualitative diagnosis. The basic scientific positions and results are the essence of the thesis received the author alone. The author made the following research: - analyzed and systematized reasons of contamination in the cavity gas pipeline; - analyzed the methodological, technical and regulatory support of technical diagnosing gas pipeline; - developed analytical methods for determining the location and extent of accumulation of fluid in the cavity gas pipeline; - developed, tested and implemented in an industrial environment in the current gas pipeline experimental model, technology information and measuring system of monitoring the presence and amount of fluid in the cavity gas pipeline. The clusters influence on safety and the gas pipelines operation modes was researched. These researches showed that liquid presence makes negatively influence at all the gas-transport system items working, complicates the main gas realization process and substantially worsens gas quality. Besides, the water presence in a gas pipeline considerably complicates the pipelines in-line inspection diagnostics procedure because in such case cleansing and diagnostic pistons damage or their destructions is possible because of the hydraulic shots. The most probable occurrence clusters places were identified. Mainly, it takes place in the ascending overfall heights areas or in deepening. The experimental studies for determination of optimal informative parameters for detection hydrate formation in the pipelines cavities have been done. An acoustic method for the accumulations volume estimation was suggested for using which consists in experimental dependences establishment of the ultrasonic vibrations amplitude with non-technological including type and thickness and ambient temperature that enables high precision (more than 0,9) the non-technological accumulations presence and their volume determination regardless of the environment parameters. An experimental model device has been developed for the non-technical clusters cavities controlling in the pipelines linear parts.