Made available in DSpace on 2016-05-02T13:55:33Z (GMT). No. of bitstreams: 1 AlanKardecdeSouza-dissertacao.pdf: 422059 bytes, checksum: ea2c6f1ec1d26f3446d1eeee444a6292 (MD5) Previous issue date: 2012-08-24 / Goat's milk is a complete food, rich in proteins, fats, vitamins and minerals. Having very small lipid molecules, it is highly digestible when compared to other types of milk. One of the great challenges for the popularization of goat milk is that many potential consumers reject it because of its odor, flavor and high price when compared to pasteurized cow milk. This study aimed at analyzing the quality of the milk commercialized in Alfenas, MG, Brazil and evaluating the effect of pasteurization and freezing on its microbiological, physico-chemical and sensory characteristics. During 270 days, 3 batches of raw, pasteurized, and pasteurized and frozen goat milk were analyzed. Each batch was assessed every 90 days. The data were submitted to ANOVA and the Tukey test. The results showed that the slow pasteurization was effective in improving the microbiological quality of the milk, while no change was found in freezing it for 90 days. The physico-chemical and sensory characteristics of the milk was not changed by pasteurization and 90-day freezing. It was concluded that the goat milk commercialized in Alfenas, MG, Both pasteurized and pasteurized and frozen, have microbiological, physico-chemical and sensory quality within the standards established by law. / O leite de cabra é um alimento completo, rico em proteínas, gorduras, vitaminas e sais minerais, possui moléculas de gordura de tamanho reduzido, apresentando alta digestibilidade comparado aos demais tipos de leites. Um dos maiores desafios para a popularização do leite de cabra é a grande rejeição por parte do público consumidor em potencial, devido ao forte odor, sabor e preço elevado comparado ao leite de vaca pasteurizado. Este trabalho objetivou analisar a qualidade do leite de cabra comercializado na cidade de Alfenas-MG e avaliar o efeito da pasteurização e do congelamento sobre suas características microbiológicas, físico-químicas e sensoriais. Durante 270 dias, foram realizadas análises microbiológicas, físico-químicas e sensoriais de 3 lotes de leite de cabra cru, pasteurizado e pasteurizado e congelado. Cada lote foi analisado a cada 90 dias. Os dados obtidos foram submetidos à análise de variância e teste de Tukey. Verificou-se que a pasteurização lenta foi eficiente para melhorar a qualidade microbiológica do leite e que o congelamento por 90 dias não a alterou. As características físico-químicas e sensoriais não foram alteradas pela pasteurização e nem após o congelamento por 90 dias. Concluiu-se que o leite de cabra, pasteurizado e pasteurizado e congelado, comercializado na cidade de Alfenas-MG possui qualidade microbiológica, físico-química e sensorial dentro dos padrões estabelecidos pela legislação.

The diploma thesis conversant problem of ventilation clean rooms of microbiological laboratory. Clean rooms pose enhanced requirements on quality distributed air, air filtrating, noisiness, humidity, stream velocity, temperature and quarantee requirement overpressures. Practical part is attention paid to solvent project solution airconditioning clean rooms of microbiological laboratory, completion need of calculations and dispose scheme of air conditioning

Orientador: Maria Helena Moraes / Banca: Roberto Lyra Villas Bôas / Banca: José Frederico Centurion / Banca: Maria de Fátima Guimarães / Banca: Ricardo Ralisch / Resumo: A suinocultura é uma exploração pecuária concentradora de dejetos, possuindo alta carga poluidora para o solo, ar e água. Nos últimos quinze anos muita atenção passou a ser dada às necessidades de desenvolvimento tecnológico, com vista à disposição dos resíduos gerados por animais, de forma a causar o mínimo impacto sobre o ambiente, obtendo um aproveitamento na reciclagem destes resíduos. O descarte destes dejetos no solo surge como uma possibilidade de reaproveitar a energia indisponível pelos vários segmentos da atividade antrópica e, desta forma, transformá-los em subprodutos através da capacidade cicladora do solo, proporcionada pela ampla diversidade de espécies microbianas e de vias metabólicas. O trabalho teve por objetivo avaliar as propriedades físicas, químicas e microbiológicas de um LATOSSOLO VERMELHO Distroférrico mediante a aplicação de resíduo líquido de suínos, após os períodos de aplicação de 3, 7 e 26 anos sob a cultura do café, em comparação com área testemunha. O delineamento experimental utilizado foi o inteiramente casualisado com 4 tratamentos e 6 repetições. As amostras de solo foram coletadas em quatro profundidades 0-0,05;0,05-0,10; 0,20-0,40; 0,60-0,80 m. Os resultados foram submetidos a análise de regressão e análise de variância e as médias comparadas pelo teste de Tukey a 5 % de probabilidade. A aplicação do resíduo líquido de suíno promoveu aumento da matéria orgânica, dos ácidos húmicos e da humina até 0,80m, em relação a área de mata. A aplicação de resíduo diminuiu o diâmetro médio ponderado dos agregados, a porcentagem de agregados com diâmetro entre 8 e 2 mm e a permeabilidade do solo, aumentou a porcentagem de agregados com diâmetro entre 2 e 0,105 mm e não influiu na macroporosidade... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Pig production is a cattle breeding exploration which aims to get dejections, having high polluted power for the soil, air and water. In the last fifteen years, a special attention has been given to the tecnologic development needs, aiming the deposition of the residue generated by animals, to cause the minimum impact in the environment, getting the utilization of these residue recicled. With the discarding of these dejections in the soil, a possibility of utilization of the energy available by the several segments of the antropic activity and, thus, transform them in subproducts through that cycling capacity of the soil, given through the wide diversity of microbes species and metabolic ways. The research had the objective to evaluate the physical, chemical and microbiological properties of an OXISOL with the application of a pig liquid residue after the application, a period of 3, 7 and 26 years over the coffee crop, in comparison with a control tratement. The experimental design used was the completely randomized with 4 treatments and 6 replications. The soil samples were collected in 4 layers in the soil 0-0.05; 0.05-0.10; 0.20-0.40; 0.60-0.80 m. The results wee submitted to regression analysis and variance analysis and the means were compared through the Tukey test with 5% of probability. The residue application decreased the medium diameter of the agregates, the percentage of agregates with diameter between 8 and 2 mm and the soil permeability, increased the percentage of agregates with diameter between 2 and 0.105 mm and didn't influenced the macroporosity, microporosity, total porosity, clay dispersed in water and the soil resistance to penetration in relation to the soil under the forest. The soil chemical properties (P, K, Ca, Mg, Zn, CTC, SB, V% e CE) were positively correlated in relation to the soil of the higher layers (0-0.05 and 0.05-0.10 m)... (Complete abstract, click eletronic address below) / Doutor

M. Tech. (Department of Chemistry, Faculty of Applied and Computer Sciences), Vaal University of Technology / Water soluble metal sulfide nanoparticles were successfully synthesized using an aqueous, simple and environmentally friendly synthetic method in the presence of ʟ-alanine, ʟ-aspartic acid and lactose, acting as both stabilizers and crystal growth modifiers. The structural and optical properties of the synthesized metal sulfide nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FTIR), Ultraviolet-visible (UV-Vis) and photoluminescence spectroscopy. Colloidal method was employed in the synthesis of CuS, ZnS and FeS nanoparticles from metal chlorides as precursors and thioacetamide (TAA) as a sulphur source. The effect of temperature on the growth and solubility of nanoparticles was investigated. The absorption spectra of all samples prepared were blue shifted as compared to their bulk materials indicating small particles size. The morphologies and sizes of the nanoparticles were influenced by the variation of temperature and capping agent. TEM images revealed interesting changes in the morphology of CuS nanoparticles formed from various capping agents. By varying the temperature, ʟ-aspartic acid-capped CuS nanoparticles changed from rod-shaped particles to particles dominated with hexagonal shape. However, the morphologies of both ZnS and FeS nanoparticles were close to spherical shape and were unaffected by either change of temperature or capping agent. Water-solubility of bio-functionalized CuS, ZnS and FeS nanoparticles was investigated. Amongst the three capping agents used, ʟ-alanine (Ala) was found to be the most effective capping agent to render solubility of the nanoparticles. As the temperature was increased, the solubility of the particles also increased. Cytotoxicity and antimicrobial activity of ʟ-alanine-capped CuS and ZnS nanoparticles were investigated. The particles were less toxic at low to moderate concentrations and only induced toxicity at higher concentrations. Particles synthesized at 95 °C were less toxic compared to other nanoparticles (35 and 65 °C) for both two set of experiments, as informed by the CC50 values. Antimicrobial properties were tested using different strains of both positive and negative bacteria and fungi. It was found that Ala-capped CuS nanoparticles were more effective against the bacteria than Ala-capped ZnS nanoparticles.

Host cell attachment by pathogenic bacteria can play very different roles in the course of infection. The pathogenic spirochetes Borrelia hermsii and Borrelia burgdorferi sensu lato which cause relapsing fever and Lyme disease, respectively, are transmitted by the bite of infected ticks. After transmission, these spirochetes can cause systemic infection. Relapsing fever spirochetes remain largely in the bloodstream causing febrile episodes, while Lyme disease will often colonize a variety of tissues, such as the heart, joint and nervous system, resulting in a chronic multisystemic disorder. Borrelia species have the ability to bind to various cell types, a process which plays a crucial role in pathogenesis and may influence spirochetal clearance from the bloodstream. Colonization of multiple tissues and cell types is likely promoted by the ability to bind to components found in target tissues, and many B. burgdorferi adhesins have been shown to promote attachment to a wide variety of cells and extracellular matrix components. Different Lyme disease strains have been shown to preferentially colonize certain tissues, although the basis of this tissue tropism is not well understood. In this study we found that among different Lyme disease strains, allelic variation of the adhesin DbpA contributes to variation in its in vitro binding activities raising the possibility that this variation contributes to tissue tropism in vivo. In studying B. hermsii infection, we found evidence by both histological and fluorescence in situ hybridization (FISH) analysis of tissues that indicated that red blood cells were removed by tissue resident macrophages in infected mice. Spirochetes in the spleen and liver were often visualized associated with RBCs, lending support to the hypothesis that direct interaction of B. hermsii spirochetes with RBCs leads to clearance of bacteria from the bloodstream. Our findings indicate that host cell attachment play a key role in the establishment of Lyme disease infection, and in contrast contributes to the clearance of relapsing fever infection.

No description available.

En pilotanläggning för ultrafiltering testas nu i Norrvattens reningsprocess för att undersöka ifall den kan användas som en tredje mikrobiologisk barriär i reningsprocessen. Målet med detta projekt är att testa membranets kapacitet att filtrera bort viruspartiklar men även membranet generella reduktionsförmåga för andra mikrobiologiska och kemiska kontamineringar. För att hitta lämpliga kandidater att använda sig av för att mäta reduktionskapaciteten av membranet har en litteraturstudie samt experimentell testning av råvattnet genomförts. OD mätningar på bakteriekulturer samt plackbildandeenheter (PBE) har undersökt för att se om bakteriofager kan finnas i proven. Ungefär 9000 L av ingående och utgående vatten från ultrafilteringen har koncentrerats med hjälp av ett elektropositivt filter som senare har eluerats och ultracentrifugerats. Pellet från ultracentrifugeringen har testat för virusdetektion med hjälp av PCR, qPCR samt PBE. TOC och absorbansmätningar har också genomförts på ingående och utgående vatten från ultrafiltermembranet. Slutligen utfördes ett bänkskaleexperiment för att undersöka hur väl filtret reducerade MS2 fager i utgående vatten. Den inledande testningen visade att plantviruset PMMoV och Pseudomonas fager kan vara bra kandidater att använda sig av för att mäta virusreduktionen över ultrafiltermembranet. När elueringen från ultrafiltreringen testades indikerades en minskad DNA koncentrationen över ultrafiltermembranet med hjälp av Qubit-mätningar. Testningen visade även indikation på att PMMoV reduceras över membranet samt att Pseudomonas fager kan finnas i vattnet. TOC och absorbansmätningarna visade en konstant reduktion över membranet. I bänkskaleexperiment borde enlig teori alla fager stoppas av membranet eftersom viruset är större än porstorleken 20 nm, dock visade experimentell testning på att fager även fanns i utgående vatten från filteringen. Resultat av studien indikerar att mikrobiologiska och kemiska kontamineringar tas bort av membranet, dock för att bestämma den exakta virusreduktionen över membranet och ifall alla kontamineringar större än filters porstorlek (20 nm) tas bort kräver vidare testning.  E. coli fager, som i Livsmedelverket nya restriktioner används för att undersöka mikrobiologiska risker i vattenreningsprocesser, har också testats under studien på vattnet utan positiva utslag. Det kan därför vara av intresse att även undersöka andra fager, så som Pseudomonas fager för att kontrollera dem mikrobiologiska riskerna med vattenrening. / The present study was investigating the effectiveness of the ultrafiltration membrane as third biological barrier in Norrvattens drinking water treatment process, using a pilot scale model. This project aims to test the viral reduction capability of the membrane but also to remove other microbiological and chemical contaminants. To find suitable candidates for measuring the reduction capability, literature research has been performed as well as experimental testing of the raw water coming into the treatment plant and the backwash water from the membrane. Bacterial growth analysis using optical density (OD) measurements and plaque forming unit (PFU) has been performed to investigate the presence of bacteriophages. Approximately 9000 L of incoming and outgoing water from the ultrafiltration membrane has been concentrated using an electropositive membrane which then was eluted and ultracentrifuged. The pellet from ultracentrifugation has been tested for viral detection with PCR, qPCR and plating. TOC and absorbance measurement was also performed on the ingoing and outgoing water from the ultrafiltration pilot plant. Finally, a bench-scale experiment was performed using MS2-spiked water to investigate how well the filter reduced MS2 phages in the outgoing water.  The initial testing of the raw and backwash water showed that the plant virus Pepper Mild Mottle Virus (PMMoV) and Pseudomonas phages may be good candidates to use when evaluating the ultrafiltration membrane. When testing the eluate from the ultrafiltration pilot plant a reduction was seen in the starting DNA concentration when comparing the inlet and outlet water to the ultrafiltration pilot plant. The testing gave indications of a reduction of PMMoV and presence of Pseudomonas phages. The bench-scale experiment was hypothesized to stop all viral particles since according to theory the virus should be stopped by the membrane due to its pore size, but experimental testing indicated viruses in the outgoing water from the membrane as well. TOC and absorbance measurements showed a constant reduction over the membrane. The result of the study indicates that microbiological and chemical contaminants are removed by the filter, however, to determine the exact viral reduction potential of the filter and if all contaminant over the size of 20 nm is removed further testing is required.  No indications were seen for Escherichia coli (E. coli) phages in the water throughout the study, which in Livsmedelverket’s (The National Food Agency) new regulations is used for determining the microbiological risks in water treatment processes. It may be of interest to investigate the possibility to also look for other type of phages to determine the microbiological risks, for example Pseudomonas phages which has been seen in this study.

Master of Science

The thesis presents an experimental investigation of combustion performance and emissions of waste cooking oil (WCO) based biodiesel. To evaluate the comparative performance of biodiesel and diesel, combustions tests were conducted using Continuous Combustion rig (CCR) and Land Rover VM diesel engine. Firstly, physical properties of WCO biodiesel and diesel samples were measured in the laboratory. Elemental analysis of WCO biodiesel showed that there are differences between the functional groups in diesel and biodiesel which lead to major differences in the combustion characteristics of the two fuel types. It was found that biodiesel had 10% lower carbon content, almost no sulphur content for biodiesel and up to 12% more oxygen content compared with diesel. This explains the lower caloric value for WCO biodiesel (up to l8 %) compared with diesel. However, higher oxygen content and double bounds in WCO biodiesel increase its susceptibility to oxidation. The CCR test results showed an increase in combustion gas temperature with the increases in biodiesel blend ratio in diesel. This was due to a faster reaction rate for biodiesel than that of diesel leading to a faster brakeage of the hydrocarbon chain to release more heat. The engine tests were performed to measure the torque and emissions for different engine speeds and loads. In general a decrease in engine torque with up to 9% for biodiesel was observed, which was due to the lower calorific value of biodiesel compared with that of diesel. The brake specific fuel consumption (BSFC) increased as the biodiesel blend ratio in diesel increases due a greater mass of fuel being injected at a given injection pressure, compared with diesel. Using WCO blends ratio up to 75% in diesel showed a reduction in exhaust emission compared with diesel, however, at the cost of increased fuel consumption. A common conclusion can be drawn in favour of the WCO biodiesel as being a greener alternative to petro-diesel when used in blend with diesel. However, due to large variations in the biomass used for biodiesel production could lead to variations in physical and chemical properties between biodiesel produced from different biomass. Therefore more stringent standards need to be imposed for biodiesel quality in order to diminish the effect of variation in physicochemical properties on engine performance and emissions. The future work in developing standard test procedures for establishing fuel properties and limits/targets would be beneficial in using a large amount of waste cooking oil in the production of biodiesel, thus contributing to reduction in CO2 and waste minimisation.

Thesis (MScMedSc)--University of Stellenbosch, 2011. / It is estimated that 32.8 million people are living with Human Immunodeficiency Virus (HIV) globally with the number of people receiving antiretroviral therapy in low- and middle- income counties increasing to more than 5 million people in 2009. These successes are threatened by treatment failure and the development of resistance to treatment. With an estimated 3.7% patients failing first line treatment after 2 years and 17.9% after 4 years on treatment there is a need for a practical and cheap in-house drug resistance assay that can be used to provide drug resistance data to clinicians and to use as a research tool to investigate drug resistance. In this study we attempted to optimize and validate an in-house drug resistance assay, adapted from Jacobs et al, 2008, to be used as a diagnostic tool and to study the presence of antiretroviral resistance in patients on the Western Cape Mother-To-Child-Transmission (MTCT) regimen. Quality control samples were received from The National Institute of Communicable Diseases AIDS Virus Research Unit, The Round Robin HIV-1 genotyping assessment system from the University of Würzburg and the QCMD assessment system were used for the optimization and validation of an in-house drug resistance assay. The ViroSeq™ HIV-1 Genotyping System was used for comparison of sample and mutation detection. It was possible to optimise and validate a genotyping assay for diagnostic testing and research use by comparison with the ViroSeq™ HIV-1 Genotyping System and evaluation with external quality assessment systems. This assay could subsequently be used to determine the development of genotypic-antiretroviral resistance in patients treated according to the provincial prevention of mother-to-child-transmission (PMTCT) protocol in the Western Cape (single dose nevirapine (sd-NVP), combined with a short course Zidovudine (AZT)). Patient samples were collected from pregnant women who took part in the Western Cape PMTCT program and visited the Tygerberg Obstetrics Clinic and Delft Community Hospital. EDTA blood was obtained to measure CD4-cell count, viral load, and to do genotyping for viral subtype and the presence of resistance mutations. Information on prior exposure to antiretroviral therapy was also collected. A detected resistance rate of 17.1% in this predominantly HIV-1 subtype C population is lower than previously recorded when sd-NVP was administered to HIV-1 subtype C positive patients in PMTCT programs. This could indicate that a dual PMTCT regimen including AZT and NVP reduces the risk of resistance to NVP relative to a regimen that uses sd-NVP. The genotyping assay uses four primers to amplify the PR and the RT gene separately to obtain PCR products, of 487 and 804 base pairs respectively for sequencing. The two PCR products were sequenced with three and five primers respectively to sequence the complete PR and approximately 250 amino acids of the RT gene. The sequences generated, thus, are analysed and aligned with the Sequencer V4.7 software to obtain a consensus sequence of approximately 1200 base pairs for analysis of resistance mutations in the protease and reverse transcriptase genes. The developed assay was hence further simplified and improved, by combining the PR and RT assay into one, which was optimised and validated for use in the routine diagnostic setting. The final genotyping assay uses 8 primers for sequencing to obtain a 1200 bp sequence for genotyping that contains the protease and the 5’ of the reverse transcriptase genes in which antiretroviral resistance associated mutations are found. The assay was accredited by SANAS in 2008.