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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Avaliação da qualidade dos queijos Minas Frescal e tipo Mussarela produzidos com leite contendo diferentes níveis de células somáticas / Evaluation of Minas Frescal and Mozzarella type cheeses manufactured from milk containing different somatic cell counts

Andreatta, Evelise 10 March 2006 (has links)
O presente estudo teve por finalidade avaliar os efeitos da contagem de células somáticas (CCS) no leite cru (nos níveis de 100-200.000, 400-500.000 e >800.000 céls./mL) sobre as características físicas, químicas, microbiológicas, sensoriais e funcionais dos queijos Minas Frescal e tipo Mussarela. Utilizou-se um delineamento experimental em parcelas subdivididas em blocos, considerando-se a contagem de células somáticas como efeito principal, os dias de análise como subparcelas e os processamentos como blocos. Cada tipo de leite foi obtido da ordenha de animais previamente selecionados de acordo com o nível de células somáticas. As etapas de elaboração dos queijos incluíram a pasteurização do leite (65º C, 30 minutos), adição de cloreto de cálcio, fermento (para a Mussarela) e coalho, coagulação e obtenção do coágulo, dessoragem, salga na massa, filagem, moldagem, salga na salmoura (para a Mussarela), e embalagem dos produtos. Os queijos foram mantidos em B.O.D. a 4 ºC e avaliados nos dias 2, 9, 16, 23 e 30 após a fabricação. A seqüência de elaboração dos queijos Minas e tipo Mussarela foi repetida 5 e 3 vezes, respectivamente, para cada tratamento. As análises realizadas nos queijos foram: pH, acidez, percentuais de gordura, matéria seca (MS), cinzas, nitrogênio total (NT), nitrogênio não protéico (NNP), nitrogênio não caseinoso (NNC), índice de proteólise, ácidos graxos livres (AGL), textura, avaliação sensorial, propriedades funcionais (capacidade de derretimento a 107 ºC e percentual de óleo livre - somente no queijo tipo Mussarela), contagem de mesófilos, psicrotróficos e número mais provável a 35 e 45 ºC. No queijo Minas Frescal, não houve interação entre CCS e dias de armazenamentos nas avaliações físico-químicas, microbiológicas, funcionais e índice de lipólise, porém houve efeito significativo (P<0,05) para índices de proteólise e profundidade da proteólise. Já para mesófilos, psicrotróficos, acidez, matéria seca, firmeza e ácidos graxos livres houve efeito significativo (P<0,05) ao avaliar dias de armazenamento. A avaliação sensorial, no primeiro dia de análise, não apresentou diferença significativa nos atributos, porém o queijo de alta CCS (> 800.000 céls./mL) diferiu dos demais no dia 30, em que recebeu menor nota em todas as características. No queijo tipo Mussarela, houve interação entre CCS e dias de armazenamento apenas para a capacidade de derretimento, resultando em aumento do derretimento no decorrer do tempo. Para as características de pH, ácidos graxos livres, índices de proteólise, extensão e profundidade da proteólise, mastigabilidade e elasticidade houve efeito significativo (P<0,05) para dias de armazenamento. Entre os atributos avaliados na sensorial, apenas a aparência apresentou diferença entre tratamentos. O rendimento dos queijos, Minas frescal e tipo Mussarela, não foram influenciados pela quantidade de células somáticas dos leites. Os resultados do trabalho indicaram que o leite destinado à fabricação dos queijos Minas e tipo Mussarela deve apresentar CCS até 400-500.000 céls./mL, de maneira a evitar alterações na qualidade dos produtos ao longo do período de armazenagem. / The aim of the present study was to evaluate the effect of somatic cells counts (SCC) in raw milk (at levels of 100-200,000, 400-500,000 and 800,000 cells./mL) on physical, chemical, microbiological, sensorial and functional characteristics of Minas frescal and Mozzarella type cheeses. A completely randomized block design was used, considering SCC as the main effect, the days of analysis as sub parcels and the processing batches as the blocks. Each type of milk was obtained from cows previously selected according to its individual SCC. The manufacture of cheeses included: pasteurization of milk (65ºC, 30 minutes), addition of calcium chloride, starter culture (for Mozzarella) and rennet, coagulation and separation of the curd, whey drainage, salting (for Minas cheese), stretching of the curd, kneading and salting in brine (for Mozzarella), and packing the products. The cheeses were stored in a B.O.D. oven at 4ºC and evaluated on days 2, 9, 16 23 and 30 after the manufacture. The sequence of elaboration of the Minas frescal and Mozzarella cheeses was repeated 5 and 3 times, respectively, for each treatment. The analyses carried out in the cheeses were: pH, acidity, percentages of fat, dry matter (DM), ashes, total nitrogen (NT), non-protein-nitrogen (NPN), non-casein nitrogen (NCN), proteolysis, free fatty acids (FFA), texture, sensorial evaluation, functional properties (melting capacity the 107 ºC and percentage of free oil - only in the cheese Mozzarella), mesophile and psychrotrophic counts and the most probable number at 30 and 45ºC. For Minas frescal cheese, no interaction was found between SCC and days of storage when considering the data on chemical, physical, microbiological, functional and lipolysis index. However, a significant effect (P<0.05) was observed for proteolysis and depth of proteolysis. For mesophiles, psychrotrophics, acidity, dry matter, firmness and free fatty acids, there was a significant effect (P<0.05) for days of storage. The sensorial evaluation made on the first day of analysis did not present significant differences for all attributes. However, the Minas cheese made with high SCC (800,000 cells/mL) differed on day 30, when it received worse grades for all the attributes. For the Mozzarella cheese, an interaction between SCC and days of storage was observed only for the melting capacity, which resulted in an increment of the melting along the time of storage. The parameters of pH, free fatty acid, proteolysis, extension and depth of proteolysis, springiness and elasticity had significant effect (P<0.05) for days of storage. Amongst the attributes evaluated in the sensorial, only the appearance presented difference between treatments. The yield of Minas frescal and Mozzarella cheese was not influenced by the amount of somatic cells in the original milk. Results indicated that milk used for the manufacture of Minas frescal and Mozzarella cheeses should present SCC up to 400-500,000 cells/mL, in order to avoid quality changes in those products during storage.
62

Avaliação de tratamento homeopático com Phytolacca decandra 30CH durante a lactação de vacas com mastite subclínica / Evaluation of homeopathic treatment with Phytolacca decandra 30CH during the lactation of cows with subclinical mastitis

Leslie Avila do Brasil Almeida 13 May 2009 (has links)
O elevado custo dos tratamentos tradicionais da mastite bovina, associado à redução de produção e inviabilidade de tratamento das mastites subclínicas durante a lactação, bem como a exigência cada vez mais rigorosa da ausência de resíduos de antimicrobianos por parte de instituições nacionais e internacionais, impulsiona o desenvolvimento de novas alternativas terapêuticas que visem minimizar o impacto das medidas tradicionais de tratamento. A homeopatia surge como importante alternativa, sendo aceita nacional e internacionalmente. O objetivo do trabalho foi avaliar o tratamento homeopático com Phytolacca decandra 30CH durante a lactação de vacas com mastite subclínica, utilizando parâmetros de qualidade do leite como Califórnia Mastitis Test (CMT), contagem de células somáticas (CCS) totais, porcentagens de polimorfonucleares (PMN) e de mononucleares (MN), teores de proteína, lactose, gordura, sólidos totais (ST) e extrato seco desengordurado (ESD), além da mensuração da produção leiteira. Foram selecionadas 26 vacas, CMT 2+ e 3+ sem sinais de mastite clínica, entre o terceiro e sexto mês de lactação, pluríparas e divididas em dois grupos, um com tratamentos medicamentosos mensais e outro com tratamentos quinzenais. Mensalmente foram colhidas duas amostras de leite de cada glândula mamária (teto) que apresentava mastite subclínica. Uma das amostras foi utilizada para CCS e análise dos componentes do leite, e a outra para identificação microbiológica. Nos grupos tratados, foi administrado o medicamento homeopático Phytolaca decandra 30CH diluído em água e aspergido nas mucosas oro-nasais e vaginais, enquanto que nos grupos denominados controle foi administrado placebo da mesma maneira. A pesagem da produção láctea de ambos os grupos foi realizada quinzenalmente até o final do experimento. Verificou-se então que não houve diferença significativa entre a produção láctea, CCS e a presença de microrganismos na secreção láctea das glândulas quando comparadas antes e depois do tratamento homeopático, dentro de cada grupo, bem como quando comparados os grupos entre si. As medianas de CMT e porcentagens de PMN foram compatíveis com infecções mamárias agudas, embora os animais tenham sido diagnosticados como portadores de mastites crônicas e em nenhum momento desenvolveram sinais clínicos. / The high cost of traditional treatments of bovine mastitis, with the reduction of production and impracticable treatment of subclinical mastitis during lactation, as well as the requirement of an increased demand for absence of antimicrobial agents residues by national and international institutions, drives the development of new therapeutic alternatives in order to minimizing the impact of traditional treatment measures. The homeopathy appears as an important alternative, accepted domestically and internationally. The objective of this work was to evaluate homeopathic treatment with Phytolacca decandra 30CH during the lactation of cows with subclinical mastitis, using some milk quality parameters as California Mastitis Test (CMT), total somatic cell count (SCC), percentages of polymorphonuclear (PMN) and mononuclear (MN) cells, levels of protein, lactose, fat, total solids and dry defatted matter, in addition to the measurement of milk production. Twenty-six cows were selected with CMT 2 + and 3 + without any signs of clinical mastitis, between the third and sixth month of lactation, pluriparous and they were divided into two groups, with monthly or biweekly drug treatments. Monthly were collected two milk samples from each mammary gland (teat) that presented subclinical mastitis. One of the samples was used for analysis of SCC and milk components, and the other one for microbiological identification. In the treated groups, was given the homeopathic medicine Phytolaca decandra 30CH diluted in water and sprayed in the oral-nasal and vaginal mucosa, while to the control group was given placebo following the same method. The weighing of the milk production for both groups was performed fortnightly until the end of the experiment. There was no significant difference between milk production, SCC and the presence of microorganisms in milk gland secretion compared before and after homeopathic treatment, within each group as well as comparing the groups together. The medians of CMT and percentages of PMN were compatible with acute mammary infection, in spite of they have been diagnosed as carriers of chronic mastitis, and at any time no clinical signs have been developed.
63

A study of natural CO₂ reservoirs : mechanisms and pathways for leakage and implications for geologically stored CO₂

Miocic, Johannes Marijan January 2016 (has links)
Carbon Capture and Storage (CCS) is a suite of technologies available to directly reduce carbon dioxide (CO2) emissions to the atmosphere from fossil fuelled power plants and large industrial point sources. For a safe deployment of CCS it is important that CO2 injected into deep geological formations does not migrate out of the storage site. Characterising and understanding possible migration mechanisms and pathways along which migration may occur is therefore crucial to ensure secure engineered storage of anthropogenic CO2. In this thesis naturally occurring CO2 accumulations in the subsurface are studied as analogue sites for engineered storage sites with respect to CO2 migration pathways and mechanisms that ensure the retention of CO2 in the subsurface. Geological data of natural CO2 reservoirs world-wide has been compiled from published literature and analysed. Results show that faults are the main pathways for migration of CO2 from subsurface reservoirs to the surface and that the state and density of CO2, pressure of the reservoir, and thickness of the caprock influence the successful retention of CO2. Gaseous, low density CO2, overpressured reservoirs, and thin caprocks are characteristics of insecure storage sites. Two natural CO2 reservoirs have been studied in detail with respect to their fault seal properties. This includes the first study of how fault rock seals behave in CO2 reservoirs. It has been shown that the bounding fault of the Fizzy Field reservoir in the southern North Sea can with hold the amount of CO2 trapped in the reservoir at current time. A initially higher gas column would have led to across fault migration of CO2 as the fault rock seals would not have been able to withhold higher pressures. Depending on the present day stress regime the fault could be close to failure. At the natural CO2 reservoir of St. Johns Dome, Arizona, migration of CO2 to the surface has been occurring for at least the last 500 ka. Fault seal analysis shows that this migration is related to the fault rock composition and the orientation of the bounding fault in the present day stress field. Using the U-Th disequilibrium method the ages of travertine deposits of the St. Johns Dome area have been determined. The results illustrate that along one fault CO2 migration took place for at least 480 ka and that individual travertine mounds have had long lifespans of up to ~350 ka. Age and uranium isotope trends along the fault have been interpreted as signs of a shrinking CO2 reservoir. The amount of CO2 calculated to have migrated out of the St. Johns Dome is up to 113 Gt. Calculated rates span from 5 t/yr to 30,000 t/yr and indicate that at the worst case large amounts of CO2 can migrate rapidly from the subsurface reservoir along faults to the surface. This thesis highlights the importance of faults as fluid pathways for vertical migration of CO2. It has been also shown that they can act as baffles for CO2 migration and that whether a fault acts as pathway or baffle for CO2 can be predicted using fault seal analysis. However, further work is needed in order to minimise the uncertainties of fault seal analysis for CO2 reservoirs.
64

Carbon dioxide enhanced oil recovery, offshore North Sea : carbon accounting, residual oil zones and CO2 storage security

Stewart, Robert Jamie January 2016 (has links)
Carbon dioxide enhanced oil recovery (CO2EOR) is a proven and available technology used to produce incremental oil from depleted fields. Although this technology has been used successfully onshore in North America and Europe, projects have maximised oil recovery and not CO2 storage. While the majority of onshore CO2EOR projects to date have used CO2 from natural sources, CO2EOR is now more and more being considered as a storage option for captured anthropogenic CO2. In the North Sea the lack of low cost CO2, in large volumes, has meant that no EOR projects have utilised CO2 as an injection fluid. However CO2EOR has the highest potential of all EOR techniques to maximise recovery from depleted UK oil fields. With the prospect of Carbon Capture and Storage (CCS) capturing large tonnages of CO2 from point source emission sites, the feasibility of CO2EOR deployment in the North Sea is high. This thesis primarily aims to address a number of discrete issues which assess the effectiveness of CO2EOR to both produce oil and store CO2. Given the fundamental shift in approach proposed in North Sea CO2EOR projects, the carbon balance of such projects is examined. Using a life cycle accounting approach on a theoretical North Sea field, we examine whether offshore CO2EOR can store more CO2 than onshore projects traditionally have, and whether CO2 storage can offset additional emissions produced through offshore operations and incremental oil production. Using two design scenarios which optimise oil production and CO2 storage, we find that that net GHG emissions were negative in both ‘oil optimised’ and ‘CO2 storage optimised’. However when emissions from transporting, refining and combusting the produced crude oil are incorporated into the life cycle calculations the ‘oil optimised scenario’ became a net emitter of GHG and highlights the importance of continuing CO2 import and injection after oil production has been maximised at a field. This is something that has not traditionally occurred. After assessing rates of flaring and venting of produced associated gas at UK oil fields it is found that the flaring or venting of reproduced CH4 and CO2 has a large control on emissions. Much like currently operating UK oil fields the rates of flaring and venting has a control on the carbon intensity of oil produced. Here values for the carbon intensity of oil produced through CO2EOR are presented. Carbon intensity values are found to be similar to levels of current UK oil production and significantly lower than other unconventional sources. As well as assessing the climate benefits of CO2EOR, a new assessment of CO2EOR potential in Residual Oil Zones (ROZ) is also made. ROZ resource, which is thought to add significant potential to both the oil reserves and CO2 storage potential in some US basins, is here identified in the North Sea for the first time. Based on the foundation of North Sea hydrodynamics study, this thesis identifies the Pierce field as a candidate ROZ field where hydrodynamic tilting of the oil water contact has naturally occurred leaving a zone of residual oil. To test the feasibility of CO2EOR in such a zone a methodology is presented and applied. Notably the study highlights that in this case study recoverable reserves from the ROZ may approach 20% of total field recoverable reserves and have the capability to store up to 11Mt of CO2. While highlighting the CO2EOR potential in the ROZ the thesis discusses the importance in expanding the analysis to quantify its importance on a basin scale. Discussion is also made on whether new resource identification is necessary in a mature basin like the North Sea. With CO2EOR being considered as a feasible option for storing captured anthropogenic CO2, it is important to assess the security of storage in CO2EOR. Using real geochemical and production data from a pilot CO2EOR development in Western Canada two approaches are used to assess the partitioning of CO2 between reservoir fluids through time. Using a number of correlations it is found that CO2 dissolution in oil is up to 7 times greater than in reservoir brine when saturations between the two fluids are equal. It is found that after two years of CO2 injection solubility trapping accounts for 26% of injected CO2. The finding that significantly more dissolution occurs in oil rather than brine indicates that CO2 storage in EOR is safer than in brine storage. However a number of factors such as the increase in oil/CO2 mobility due to CO2 injection is also discussed. The overall conclusion from the work is that CO2EOR in the North Sea has the potential to be an effective way of producing oil and storing CO2 in the North Sea. A number of design, operational and accounting factors are however essential to operate an exemplar CO2EOR project where low carbon intensity oil can be produced from a mature basin while storing large tonnages of captured anthropogenic CO2.
65

Avaliação dos medicamentos homeopáticos Sulphur 30CH e Calcarea carbonica 30CH para tratamento de vacas com mastite subclínica / Evaluation of homeopathic Sulphur 30CH and Calcarea carbonica 30CH for treatment of cows with subclinical mastitis

Sakiyama, Débora Tieko Parlato 22 September 2010 (has links)
O uso de antibióticos para tratamento da mastite bovina subclínica durante a lactação apresenta restrições econômicas e a administração indiscriminada e inadequada destes medicamentos os torna potencialmente tóxicos aos animais e aos consumidores finais dos produtos lácteos. A utilização de medicamentos homeopáticos oferece menor custo, facilidade de administração, não há risco de resistência microbiana e não é necessário o descarte do leite dos animais em tratamento. Além disso, a homeopatia é reconhecida no Brasil como especialidade médica veterinária e aceita para uso no sistema de produção animal orgânico. Portanto, o presente trabalho teve como objetivo avaliar a eficácia de dois protocolos homeopáticos para tratamento da mastite bovina subclínica durante a lactação. O experimento foi realizado no período de seis meses e dividido em duas etapas. Na Etapa I, um grupo foi medicado com Sulphur 30CH, enquanto que o outro recebeu placebo. Na Etapa II, um grupo foi medicado com Calcarea carbonica 30CH e o outro grupo recebeu placebo. Os medicamentos foram administrados a cada trinta dias na Etapa I e a cada quinze dias na Etapa II. Em cada etapa foram coletadas amostras de leite antes, durante e após o tratamento. Para avaliar a eficácia dos protocolos, durante o experimento foram analisadas 138 amostras de leite na Etapa I e 72 amostras na Etapa II, realizando-se prova de Tamis, California Mastitis Test (CMT), contagem de células somáticas (CCS), quantificação de polimorfonucleares (PMN) e mononucleares (MN) por microscopia óptica, exame microbiológico e mensuração da produção leiteira. As análises estatísticas foram realizadas utilizando o software Graphpad Instat 1990-93. Os protocolos homeopáticos testados não diminuíram a celularidade do leite, pois não houve diferenças significativas nos resultados do CMT e da CCS no decorrer do experimento. Também não foi constatada nenhuma alteração significante na produção láctea. O microrganismo isolado com maior frequência no rebanho estudado foi o Corynebacterium bovis. Porém, não houve diferenças significativas em relação à frequência de isolamento deste microrganismo ao longo dos tratamentos, indicando a sua permanência nas glândulas mamárias. Além disso, observou-se durante todo o experimento o predomínio de células PMN em relação às MN. Sugere-se o estudo de novos protocolos homeopáticos com outros medicamentos, potência e frequência de administração, a fim de buscar alternativas para o tratamento de vacas com mastite subclínica / The use of antibiotics for treatment of bovine subclinical mastitis during lactation presents economic restrictions and the indiscriminate and inappropriate administration of these drugs makes them potentially toxic to animals and consumers of dairy products. The use of homeopathic medicine offers lower cost, ease of administration, no risk of microbial resistance and is not necessary to discard milk from animals under treatment. Furthermore, homeopathy is recognized as a medical specialty in Brazil and support for veterinary use in organic livestock production system. Therefore, this study aimed to evaluate the effectiveness of two protocols for homeopathic treatment of bovine subclinical mastitis during lactation. The experiment was performed between six months and divided into two stages. In Phase I, one group was treated with Sulphur 30CH, while the other received placebo. In Phase II, one group was treated with Calcarea carbonica 30CH and the other group received placebo. The drugs were administered every thirty days in the Phase I and every fifteen days in the Phase II. At each step the milk samples were collected before, during and after treatment. To evaluate the effectiveness of the protocols during the experiment were analyzed 138 samples of milk at Phase I and 72 samples at Phase II, performing proof Tamis, California Mastitis Test (CMT), somatic cell count (SCC), quantification of polymorphonuclear (PMN) and mononuclear (MN) by optical microscopy, microbiological examination and measurement of milk production. Statistical analysis was performed using the software Graphpad Instat 1990-93. The homeopathic protocols tested not diminished cellularity of milk because there were no significant differences in the results of CMT and SCC during the experiment. Nor was it found no significant change in milk production. The organism isolated most frequently in the herd studied was Corynebacterium bovis. However, no significant differences were observed in the frequency of isolation of this microorganism during the treatments, indicating his permanence in the mammary glands. Furthermore, it was observed during the experiment a predominance of PMN cells compared to MN. It is suggested the study of new protocols with other homeopathic medicines, potency and frequency of administration, to find alternatives for the treatment of cows with subclinical mastitis
66

Comparação entre a quantidade de unidades formadoras de colônias (UFC) e contagem de células somáticas (CCS) de leite proveniente de glândulas mamárias de bovinos com mastite subclínica e associadas à presença de Staphylococcus spp. e Streptococcus spp. e a associação de ambos microrganismos / Comparison between the amount of colony forming units (CFU) and the somatic cells count (SCC) from milk taken from bovines mammary glands, suffering from subclinical mastitis, associated to the presence of Staphylococcus spp. and Streptococcus spp. as well as the association of both microorganisms

Von Sydow, Anna Catharina Maia Del Guercio 18 August 2010 (has links)
A mastite é uma doença complexa que pode ter diferentes causas, graus de intensidade e variações de duração e de conseqüências. Os processos inflamatórios na glândula mamária são especialmente freqüentes e importantes em bovinos leiteiros. A mastite infecciosa é a mais importante sob os pontos de vista econômico e de saúde pública. A forma subclínica é a mais onerosa e prevalente com um comprometimento mundial de 40% do rebanho leiteiro e perdas econômicas entre 5% e 25% da produção leiteira. No Brasil, a mastite subclínica caracteriza-se pela alta incidência, com índices variando de 44,88% a 97,0%, e a redução da produção leiteira situa-se entre 25,4% e 43,0%. Dentre os agentes etiológicos mais isolados em casos de mastite subclínica destacam-se os Staphylococcus spp., os Streptococcus spp. e o Corynebacterium bovis. A quantidade de UFC/mL no leite proveniente diretamente da glândula mamária bovina com infecção permitiria o conhecimento da quantidade de microrganismos associada a uma determinada intensidade de processo inflamatório na glândula. A comparação destas informações com a contagem de células somáticas na amostra avaliaria mais acuradamente a natureza do processo inflamatório e infeccioso na glândula. Importante seria o risco que representa a presença de microrganismos no leite, sobretudo se considerar o hábito do consumo de leite in natura, verificando em um estudo quantitativo desta natureza, a carga microbiana ingerida pelo homem. Foram examinadas 80 amostras de leite de vacas mestiças ou holandesas, primíparas e multíparas, em diferentes estágios de lactação de plantéis do Estado de São Paulo. Quatro grupos foram formados de 20 animais cada: grupos com crescimento negativo, de Staphylococcus spp. e Streptococcus spp. em cultura pura e grupo com a associação de ambos microrganismos. O objetivo deste trabalho consistiu em avaliação comparativa da quantidade de UFC/mL de microrganismos e CCSs no leite proveniente de glândulas mamárias bovinas, associadas com a presença dos microrganismos Staphylococcus spp. e Streptococcus spp. e infecções mistas ocorridas com a presença de ambos. Tanto Staphylococcus spp. (mediana = 4,772), quanto Streptococcus spp. em cultura pura (mediana = 5,933), não apresentam diferenças significativas na contagem de UFC com seus respectivos agentes em associação (Staphylococcus spp. com mediana da associação foi de 5,048 e mediana de Streptococcus spp. da associação foi de 5,792). Nas amostras em que houve crescimento de Staphylococcus spp. e Streptococcus spp. associados, a quantidade de UFC de Streptococcus spp. foi estatisticamente maior. Comparados entre si (crescimento em cultura pura de Staphylococcus spp. com mediana = 5,765 e Streptococcus spp., mediana = 5,920), mesmo apresentando um maior número na CCSs no grupo de crescimento de Streptococcus spp., este aumento não foi significativo estatisticamente. Porém, quando associados (mediana = 5,673), comparados à cultura pura de Staphylococcus spp. (mediana = 5,765), este último teve aumento significativo. Tanto em cultura pura como em associação, a presença dos microrganismos quando comparados, não induziram a um aumento significativo na CCSs ou à contagem de UFCs em amostras de leite com sinais de mastite subclínica, porém Staphylococcus spp. induziu maior contagem de células somáticas / Mastitis is a complex disease that can occur due to different causes, intensity of degrees and variation of duration and consequences. The inflammatory processes in the mammary gland are specially frequent and important in dairy producing cattle. The infectious mastitis is the most important because of the economic aspects and public health. The subclinical manifestation is the most expensive and prevailing affecting 40% of the milk producing herd and causing an economic loss between 5% and 25% of all dairy production. In Brazil, the subclinical mastitis is characterized by high incidence, with indexes varying from 44,8% to 97,0 % with the reduction of milk production between 25,4% and 43%. Among the more isolated etiological agents in subclinical mastitis, is the Staphylococcus spp., the Streptococcus spp. and the Corynebacterium bovis. The amount of CFU/mL in the milk directly originated from the infected cow mammary gland would make possible to know the amount of microorganisms associated to a determined intensity of inflammatory process in the gland. The comparison between this information with the number of body cells in the sample would evaluate more precisely the nature of the inflammatory process in the gland. The risk represented by the presence of microorganisms in the milk is very important mainly because of the habit of milk consumption in natura, checked in a quantitative study of this nature, based on the amount of microbes intake by man. Eight milk samples of half-breed cows and Dutch cows were examined as well as those in first or after various calving, in different lactation stages in breeding stocks in São Paulo State. Four groups were organized, with 20 animals in each with negative Staphylococcus spp. growth and Streptococcus spp. in pure culture and group, with the association of both microorganisms. The purpose of this study is the comparative assessment of the amount of CFU/mL of microorganisms and CCSs in the milk from the mammary bovine glands, associated with the presence of microorganisms Staphylococcus spp. and Streptococcus spp. and a mixed infection that occurred with the presence of both. The Staphylococcus spp. (median = 4,772) as well as the Streptococcus spp. in pure culture (median= 5,933) did not show significant differences in the CFU count, with their respective agents in association (Staphylococcus spp. with median of association was of 5,048 and median of Streptococcus spp. of the association was of 5,792). On the samples in which there was a growth of Staphylococcus spp. and Streptococcus spp. associated, the amount of CFU of Streptococcus spp. was statistically larger. Compared between themselves (growth in pure culture of Staphylococcus spp., median = 5,920, this increase wasnt statistically significant. Although when associated (median=5,673), compared to the pure culture of Staphylococcus spp. (median=5,765), the latter had a significant increase. In pure culture as well as in association, the presence of microorganisms when compared to a significant increase in CCSs or to the CFUs count in milk samples with indication of subclinical mastitis, but the Staphylococcus spp. induced a larger count of somatic cells
67

Design of Metal-Organic Frameworks for Carbon Capture Applications: Approaches for Adsorptive Separation of CO2/N2 and O2/N2 Mixtures

January 2019 (has links)
abstract: The large-scale anthropogenic emission of carbon dioxide into the atmosphere leads to many unintended consequences, from rising sea levels to ocean acidification. While a clean energy infrastructure is growing, mid-term strategies that are compatible with the current infrastructure should be developed. Carbon capture and storage in fossil-fuel power plants is one way to avoid our current gigaton-scale emission of carbon dioxide into the atmosphere. However, for this to be possible, separation techniques are necessary to remove the nitrogen from air before combustion or from the flue gas after combustion. Metal-organic frameworks (MOFs) are a relatively new class of porous material that show great promise for adsorptive separation processes. Here, potential mechanisms of O2/N2 separation and CO2/N2 separation are explored. First, a logical categorization of potential adsorptive separation mechanisms in MOFs is outlined by comparing existing data with previously studied materials. Size-selective adsorptive separation is investigated for both gas systems using molecular simulations. A correlation between size-selective equilibrium adsorptive separation capabilities and pore diameter is established in materials with complex pore distributions. A method of generating mobile extra-framework cations which drastically increase adsorptive selectivity toward nitrogen over oxygen via electrostatic interactions is explored through experiments and simulations. Finally, deposition of redox-active ferrocene molecules into systematically generated defects is shown to be an effective method of increasing selectivity towards oxygen. / Dissertation/Thesis / Masters Thesis Chemical Engineering 2019
68

VENUS : un outil d'aide à la vérification des systèmes communicants

Soriano Montes, Amelia 09 January 1987 (has links) (PDF)
Description d'un outil d'aide à la conception et à la vérification de systèmes communicants qui est basé sur le calcul CCS de Milner.
69

Design and remote control of a Gantry mechanism for the SCARA robot

Surinder Pal, 15 May 2009 (has links)
Remote experimentation and control have led researchers to develop new technologies as well as implement existing techniques. The multidisciplinary nature of research in electromechanical systems has led to the synergy of mechanical engineering, electrical engineering and computer science. This work describes the design of a model of a Gantry Mechanism, which maneuvers a web-cam. The user controls virtually the position of end-effecter of the Gantry Mechanism using a Graphical User Interface. The GUI is accessed over the Internet. In order to reduce the unbalanced vibrations of the Gantry Mechanism, we investigate the development of an algorithm of input shaping. A model of the Gantry Mechanism is built, and it is controlled over the Internet to view experimentation of the SCARA Robot. The system performance is studied by comparing the inputs such as distances and angles with outputs, and methods to improve the performance are suggested.
70

Design and remote control of a Gantry mechanism for the SCARA robot

Surinder Pal, 15 May 2009 (has links)
Remote experimentation and control have led researchers to develop new technologies as well as implement existing techniques. The multidisciplinary nature of research in electromechanical systems has led to the synergy of mechanical engineering, electrical engineering and computer science. This work describes the design of a model of a Gantry Mechanism, which maneuvers a web-cam. The user controls virtually the position of end-effecter of the Gantry Mechanism using a Graphical User Interface. The GUI is accessed over the Internet. In order to reduce the unbalanced vibrations of the Gantry Mechanism, we investigate the development of an algorithm of input shaping. A model of the Gantry Mechanism is built, and it is controlled over the Internet to view experimentation of the SCARA Robot. The system performance is studied by comparing the inputs such as distances and angles with outputs, and methods to improve the performance are suggested.

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