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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.
101

Avaliação da atividade micobactericida de desinfetantes químicos utilizando a técnica de cultivo em camada de ágar Middlebrook 7H11 / Evaluation of mycobactericidal activity of chemical disinfectants using the Middlebrook 7H11 agar medium technique

Flávia Morato 11 July 2007 (has links)
Avaliou-se a atividade micobactericida de cinco desinfetantes químicos frente a uma estirpe de Mycobacterium bovis isolada de caprinos, tipificada por PCR (polymerase chain reaction) e com 32 dias de cultivo no meio de Stonebrink. O teste de desinfetantes foi realizado utilizando-se a técnica de cultivo em camada delgada de ágar Middlebrook 7H11 modificado e foi comparado ao teste em tubos com meio de Stonebrink, tradicionalmente utilizado no laboratório de zoonoses bacterianas da FMVZ/USP. Os cinco desinfetantes ensaiados foram: \"A\" : grupo controle; \"B\" - hipoclorito de sódio (2,5 % de cloro ativo); \"C\"- glutaraldeído (2 %); \"D\" - ácido peracético 0,25 % e peróxido de hidrogênio 5 %; \"E\" - iodóforo (2,6% de iodo) e \"F\"- compostos fenólicos (orto-fenilfeno 12,243 g; orto-benzil paraclorofenol 11,080 g; para-terceário amilfeno 4,1222 g.). A diluição destes produtos foi feita conforme recomendação do fabricante. Os meios de cultura adotados para o procedimento de isolamento e preparo da suspensão bacteriana foram o meio de Stonebrink e o meio de Middlebrook 7H11 modificado. Os testes foram realizados na presença e ausência de matéria orgânica e à temperatura ambiente (21 ± 2°C) e à temperatura de 4 °C. Os resultados obtidos nas contagens de colônias foram transformados em percentual de redução para análise estatítica e demostraram que: a técnica de cultivo de micobactérias em camada delgada no meio de Middlebrook 7H11 permitiu uma visualização precoce das micobactérias e se mostrou viável para realização de testes de desinfetantes; os cinco tipos de desinfetantes analisados apresentaram atividade micobactericida e o melhor desempenho foi obtido pelo ácido peracético seguido pelo hipoclorito de sódio. A atividade micobactericida dos iodóforos foi instisfatória na presença de matéria orgânica. / The mycobactericidal activity of five chemical disinfectants was evaluated against a strain of Mycobacterium bovis isolated from a goat, typified by PCR (polymerase chain reaction) and with 32 days of growth in the Stonebrink medium. The disinfectants were tested using the modified thin layer Middlebrook 7H11 cultivation technique and it was compared to the test made in tubes with Stonebrink medium, which is tradicionally used at the Bacterian Zoonosis Laboratory of the Veterinary Medicice Faculty of the University of São Paulo. The five disinfectants were: \"A\" was the control group; \"B\"- sodium hypochlorite (2,5% of active chlorine); \"C\"- glutaraldehyde (2 %); \"D\"- peracetic acid (0,25 %) and hydrogen peroxide (5 %); \"E\" - iodine compounds (2,6%) e \"F\"- fenolic compounds (orto-fenilfeno 12,243 g; orto-benzil paraclorofenol 11,080 g; para-terceario amilfeno 4,122 g.). The products were diluted according to label instructions. The culture media used for the isolation procedure and preparation of the bacterian suspension were the Stonebrink and modified Middlebrook 7H11 medium. The assays were performed either in the presence or absence of organic matter, at temperatures of 4 °C and 21 ± 2°C The colony counting results were transformed into reduction percentages for the statistical analysis and concluded in: the modified thin layer Middlebrook 7H11 cultivation technique permitted an earlier visualization of the colonies and was practible for the realization of the disinfectants tests; the five disinfectants showed mycobactericidal activity and the peracetic acid had the best performance followed by the sodium hypochlorite. The mycobactericidal activity of the iodine compound was unsatisfactory when in the presence of organic matter.
102

Avaliação da viabilidade de oocistos esporulados de Neospora caninum a diferentes condições de temperatura e ação de desinfetantes / Evaluation of the viability of sporulated oocysts of Neospora caninum under different temperature and disinfectants treatments

Aldo Francisco Alves Neto 26 October 2009 (has links)
Neospora caninum é um parasita Apicomplexa que causa doença neuromuscular em cães e abortamento em bovinos. Cães e coiotes são as únicas espécies reconhecidas como hospedeiros definitivos, nas quais ocorre a fase sexuada do ciclo evolutivo do N. caninum, com eliminação de oocistos através das fezes, os quais esporulam no ambiente e tornam-se infectantes. Apesar da importância dos oocistos como fonte de infecção para várias espécies de hospedeiros, a viabilidade e resistência desses oocistos a tratamentos físicos e químicos ainda são desconhecidas. Este estudo teve por objetivo avaliar a viabilidade de oocistos esporulados de N. caninum após tratamentos com diferentes desinfetantes, temperaturas e tempos de exposição. Três cães foram alimentados com tecido cerebral de búfalos soropositivos para anticorpos anti-N.caninum pela reação de imunofluorescência indireta (RIFI 100) para a obtenção de oocistos. Desses, somente um cão eliminou oocistos tipo Neospora-Hammondia sendo confirmado serem de N. caninum por bioensaio em gerbilos e por métodos moleculares (PCR-RFLP). Os oocistos esporulados foram purificados e 11 alíquotas contendo aproximadamente 3000 oocistos por alíquota constituíram cada um dos tratamentos, sendo estes: Formol 10% por 1h; Amônia 10% por 1h; Álcool 70% por 1h; Álcool absoluto por 1h; Iodo 2% por 1h; Hipoclorito de sódio 10% por 1h; Temperatura ambiente, controle; -20ºC por 6h; 4ºC por 6h; 60ºC por 1m e 100ºC por 1m. Os tratamentos químicos foram todos realizados à temperatura ambiente. Após tratamento os oocistos foram divididos em alíquotas com 1000 oocistos cada e estas foram administradas, via oral, a gerbilos (1000 oocistos por gerbilo) sendo cada grupo experimental constituídos por três animais. Depois de 63 dias os gerbilos foram sacrificados e colheu-se sangue para a pesquisa de anticorpos anti-N. caninum (RIFI e western blotting) e tecidos para a pesquisa de cistos em esfregaço direto de cérebro e DNA do parasito (PCR em tempo real), além de pesquisa do agente por técnicas histopatológicas e imuno-histoquímica. Considerou-se eficaz o tratamento que confirmou a inviabilidade dos oocistos por resultados negativos em todas as cinco provas realizadas. Dos tratamentos realizados mostrou-se eficaz o uso de calor a 100ºC por 1 minuto e do hipoclorito de sódio a 10% por 1 hora, podendo ser estes indicados para o controle dessas formas no ambiente. / Neospora caninum is an Apicomplexan parasite that causes neuromuscular disorders in dogs and abortion in cattle. Dogs and coyotes are the only species identified as definitive hosts. The sexual phase of the N. caninum life cycle occurs within the host, and results in the shedding of oocysts in the feces that will sporulate in the environment and become infective. Despite their relevance as a source of infection for a number of different hosts, the resistance and viability of such oocysts to physical and chemical treatments are yet to be known. The purpose of this study was to assess the viability of N. caninum sporulated oocysts after exposure to treatments using different disinfectants, temperatures and periods of time. For acquisition of the oocysts, three dogs were fed brain tissue from buffaloes positive for antibodies to N. caninum by an indirect fluorescent antibody test (IFAT 100). Only one of the dogs excreted Neospora-Hammondia type oocysts. Such oocysts were confirmed to be N. caninum by bioassay in gerbils and molecular methods (PCR-RFLP). The sporulated oocysts were purified and 11 doses with approximately 3,000 oocysts each were treated as follows: 10% formaldehyde (formol) for 1 h; 10% ammonia for 1 h; 70% alcohol for 1 h; absolute alcohol for 1 h; 2% iodine for 1 h; 10% sodium hypochlorite for 1 h; Room temperature, control; -20ºC for 6 h; 4ºC for 6 h; 60ºC for 1 min, and 100ºC for 1 min. All chemical treatments were performed at room temperature. After treatment, the oocysts were divided into doses of 1,000 oocysts each and administered into three gerbils (Meriones unguiculatus) orally (1,000 oocysts per gerbil) per treatment. The gerbils were euthanized after 63 days. Blood samples were taken to be tested for the presence of N. caninum antibodies (IFAT and Western blotting analysis), and tissues samples to be tested for the presence of cysts by brain smear technique and detection of the parasite DNA (real-time PCR), and the identification of the parasite by immunohistochemical and histopathological examinations. In order to be considered an effective treatment, negative results should be observed in the gerbils of all five evaluations conducted. Out of the treatments carried out in this study, exposures to a temperature of 100ºC for 1 min and to a 10% sodium hypochlorite solution for 1 h were effective.
103

Limpeza e desinfecção em galpões de frango de corte: eficiência, produtividade e avaliação econômico-financeira frente a Campylobacter spp. / Cleaning and disinfection of poultry houses: efficiency, productivity and economic valuation against Campylobacter spp.

Maria Fernanda de Castro Burbarelli 22 July 2016 (has links)
Os procedimentos de limpeza e desinfecção usados na produção frangos de corte são fundamentais para a manutenção do alto nível de saúde do plantel, reduzindo o risco de ocorrência de enfermidades e melhorando o desempenho produtivo das aves. Existe a possibilidade de contaminação dos produtos desde a chegada das aves às instalações até o abate. Campylobacter é uma bactéria constantemente encontrada no trato gastrointestinal das aves e merece destaque na produção avícola devido a sua capacidade de provocar enfermidades em humanos. Para evitar a ocorrência de surtos de doenças transmitidas por alimentos como a campilobacteriose, para manutenção da saúde de plantéis avícolas e o aumento da produtividade de lotes de frangos de corte é necessário a realização das práticas preventivas como a limpeza e desinfecção. Desta maneira, o presente estudo teve como objetivos avaliar: o desempenho produtivo em lotes de frangos de corte desafiados com Campylobacter jejuni, a redução da pressão de infecção em instalações submetidas a diferentes protocolos de limpeza e desinfecção, e sua viabilidade econômico-financeira. Foi conduzido protocolo experimental no Laboratório de Pesquisa em Aves do departamento de Nutrição e Produção Animal, da Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo, Campus Pirassununga. Foram realizados dois alojamentos cada um com 960 pintos de um dia de idade. No primeiro alojamento, todas as aves foram inoculadas com uma cepa conhecida de Campylobacter jejuni (atcc 33560) a fim de contaminar o ambiente criando desafio sanitário. No segundo alojamento foram realizados dois protocolos de limpeza e desinfecção, constituindo os dois tratamentos experimentais (Comum e Proposto). Neste lote, para avaliação da produtividade, foram mensurados os parâmetros: viabilidade, mortalidade, conversão alimentar, ganho de peso e consumo de ração. Para avaliação microbiológica do ambiente e das carcaças foi realizada a contagem total de microrganismos para ambiente e a identificação de Campylobacter spp.. As amostras positivas foram submetidas a um ensaio de PCR multiplex para identificação de espécies de Campylobacter spp. Para avaliação econômica financeira dos lotes de frangos de corte foram utilizados e adaptados os dados de custos de produção elaborados pela Embrapa Suínos e Aves às condições de criação e resultados obtidos no presente estudo. O tratamento Proposto demonstrou influências positivas no desempenho das aves, na redução da contagem total de microrganismos, na eliminação de Campylobacter spp. e viabilidade econômico-financeira / The procedures of cleaning and disinfection used in broiler production are necessary to maintaining a high standard of birds health, decreasing the risk of diseases, optimizing the animal performance, as well as to ensure sanitary quality of meat. There is possibility of contamination in all farming steps, since chicks arrival until the end of slaughter. Campylobacter is a bacteria constantly found at gastrointestinal tract of the birds, and so, a special concern must be given since it can cause human diseases. In order to avoid foodborne illness outbreaks such as campylobacteriosis, to ensure poultry flocks health maintenance and to improve broilers productivity, adopting preventive practices such as cleaning and disinfection is required. Thus, this study aimed to evaluate: the animal performance of broilers challenged with Campylobacter jejuni; the reduction of infection pressure in housing plants subjected to different cleaning protocols and disinfection, and its economic and financial viability. Experimental protocol was conducted at the Research Laboratory of Poultry of Nutrition and Animal Production Department, College of Veterinary Medicine and Animal Science, University of São Paulo, Campus Pirassununga. Two housings each with 960 day-old chicks of age were performed. In the first housing, all birds were inoculated with a known strain of Campylobacter jejuni (ATCC 33560) to contaminate the environment in order to create health challenge. In the second housing were performed two cleaning and disinfection protocols, featuring two experimental treatments (Common and Proposed). In this lot, to evaluate animal performance, the parameters were measured: feasibility, mortality, feed conversion, weight gain and feed intake. For microbiological evaluation of environment and of carcasses, was performed a total count of microorganisms for environmental and identification of Campylobacter spp. The positive samples were subjected to a multiplex PCR assay identification of species of Campylobacter spp. For economic and financial evaluation of batches, the data of husbandry costs elaborated by Embrapa Swine and Poultry were adapted to conditions and rsults obtained in this study. Based on results, the Proposed treatment has shown positive influences on bird performance, reduction of total count of microorganisms, on elimination of Campylobacter spp. and on economic and financial viability
104

Efeito de desinfetantes hospitalares sobre células vegetativas e esporos de Ribotipos de Clostridium Difficile isolados exclusivamente no Brasil

Ferreira, Thaís Gonçalves 19 April 2017 (has links)
Submitted by Biblioteca da Faculdade de Farmácia (bff@ndc.uff.br) on 2017-04-19T18:55:50Z No. of bitstreams: 1 Ferreira, Thaís Gonçalves [Dissertação, 2012].pdf: 3520619 bytes, checksum: 0a743346b244c2aef9fcdf90c62f99ae (MD5) / Made available in DSpace on 2017-04-19T18:55:50Z (GMT). No. of bitstreams: 1 Ferreira, Thaís Gonçalves [Dissertação, 2012].pdf: 3520619 bytes, checksum: 0a743346b244c2aef9fcdf90c62f99ae (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Fundação de Amparo a Pesquisa do Estado do Rio de Janeiro / Ministério da Ciência e Tecnologia (MTC/Pronex) / Ministério da Saúde do Brasil / INTRODUÇÃO: Clostridium difficile é um importante patógeno entérico e o agente etiológico da diarreia associada ao C. difficile (CDAD). Pacientes com CDAD excretam uma grande quantidade de células vegetativas e esporos em suas fezes, levando a contaminação do ambiente hospitalar e propagação deste patógeno. Este fato pode ser explicado pela resistência dos esporos a muitos desinfetantes utilizados na rotina de desinfecção hospitalar. O objetivo deste estudo foi avaliar a atividade de desinfetantes hospitalares contra os esporos e células vegetativas de C. difficile. Além disso, foram analisados os perfis de proteínas totais das células vegetativas das cepas de C. difficile, tratadas com os mesmos desinfetantes. MÉTODOS: Os agentes de limpeza hospitalar Virkon® (peroxigênio), Cloro-Rio® (agente liberador de cloro ativo), Peresal® (peroxigênio), Riohex® (biguanida), e Cidex Opa® (aldeído), comumente utilizados em hospitais brasileiros, foram testados contra os esporos das cepas de C. difficile HU17- ribotipo 133 e SJ1-ribotipo 135, ambos ribotipos encontrados exclusivamente no Brasil. A cepa hipervirulenta de C. difficile, BI/NAP1/027, foi utilizada para comparação. Os testes foram realizados de acordo com o método padrão para teste da atividade esporocida de desinfetantes dos Estados Unidos, ASTM E2414-05. Para a análise do perfil de proteínas totais, as mesmas cepas de C. difficile, incluindo também a ATCC 9689, foram crescidas na presença e na ausência de concentração subinibitória dos desinfetantes citados e submetidas a eletroforese em gel de SDS-PAGE. RESULTADOS: Os agentes Cloro-Rio® e Cidex Opa® eliminaram completamente os esporos de todas as cepas testadas, enquanto o Riohex® não exibiu qualquer redução significante. Por outro lado, o Virkon® reduziu significativamente a concentração de esporos para as cepas HU17-133 e BI/NAP1/027, mas o mesmo não foi observado com a cepa SJ1-135. O agente Peresal® eliminou completamente os esporos da cepa HU17-133, mas apenas reduziu a concentração inicial dos esporos para as cepas C. difficile SJ1-135 e BI/NAP1/027. Os desinfetantes Cloro- Rio® e Riohex® foram os que mais afetaram a expressão de proteínas em todas as cepas avaliadas. CONCLUSÕES: Em conjunto, nossos resultados mostraram que o Cloro-Rio® e Cidex Opa® foram os desinfetantes mais eficazes para eliminação dos esporos de C. difficile. O estudo das proteínas afetadas pelos desinfetantes poderia ajudar a elucidar a resistência do C. difficile frente a alguns agentes de limpeza e criar novas alternativas para eliminar e/ou diminuir a contaminação do ambiente hospitalar por esta bactéria / Introduction: Clostridium difficile is an important enteric pathogen and the etiological agent of C. difficile-associated diarrhea (CDAD). Patients with CDAD, excrete a large amount of vegetative cells and spores in their stools, leading to contamination of the hospital environment and spread of the pathogen. This fact can be explained by the resistance of spores to many disinfectants used in hospital routine. The aim of this study was to evaluate the activity of hospital disinfectants against C. difficile spores and vegetative cells. Furthermore were analyzed the whole proteins profiles of the vegetative cells of these strains treated with the same disinfectant. METHODS: The hospital cleaning agents Virkon® (peroxygen), Cloro-Rio® (chlorine), Peresal® (peroxygen), Riohex® (biguanide), and Cidex Opa® (aldehyde), usually used in Brazilian hospitals, were tested against C. difficile strains spores HU17-ribotype 133 and SJ1-ribotype 135, both exclusively Brazilian. BI/NAP1/ribotype 027 strain was also used for comparison. The tests were performed in accordance with the standard method for testing the sporicidal activity of disinfectants of the United States, ASTM E2414-05. For the analysis of whole proteins profile, the strains were grown in the presence and absence of sub inhibitory concentrations of the disinfectants and applied on SDS-PAGE gel. RESULTS: Cloro-Rio® and Cidex Opa® completely eliminated spores of all strains tested, while Riohex® did not show any significant reduction. On the other hand, Virkon® significantly reduced HU17 and BI/NAP1/027 spores, but the same was not observed with SJ1 strain. The agent Peresal® completely eliminate the spores of strain HU17-133, but only reduced the initial concentration of spores for strains SJ1-135 and BI/NAP1/027. The disinfectants Cloro-Rio® and Riohex® were the most affected protein expression in all strains evaluated. CONCLUSIONS: Taken together, our results show that Cloro-Rio® and Cidex Opa® are the most remarkable agents for eliminating spores. The study of proteins affected by the disinfectant might help to elucidate the resistance of C. difficile against some cleaning agents and create new alternatives to eliminate and/or reduce the contamination of the hospital by this bacterium
105

A review of chemical disinfection methods for minimally processed leafy vegetables

Velez Rivera, Edwin January 1900 (has links)
Master of Science / Food Science Program / Thomas J. Herald / For the last decade in the U.S., consumers have demanded fresh, healthier convenience-type foods namely, fresh-cut vegetables. Globalization has played a major role in rapid growth of the fresh-cut industry sector. Thus, consumers may purchase their favorite seasonal vegetables in local grocery stores year-round. However, the convenience of year-round produce availability brings the potential of foodborne outbreaks. Thirty-two states reported 190 produce-associated outbreaks, 16,058 reported illnesses, 598 hospitalizations, and eight deaths from 1973 to 1997. Pathogenic bacteria contaminate raw agricultural commodities through various pathways such as irrigation with untreated water, use of noncomposted animal manure as fertilizer, and wash water systems. The increasing number of produce-related outbreaks has raised awareness to interventions that remove human pathogens on fresh produce. Washing solely with tap water cannot be relied upon to completely remove pathogens. Chlorinated water is the most frequently used sanitizer, however, reductions are less than 2.63-log CFU/g on leafy and salad vegetables. Such reductions, although significant, are not sufficient to assure the microbial safety of minimally processed vegetables. The efficacy of several other chemical agents such as chlorine dioxide, ozone, electrolyzed water, hydrogen peroxide, organic acids, and other commercial products have been evaluated as potential alternatives to chlorine.
106

Disinfection of secondary treated sewage by chlorine in a continuous flow reactor.

Heller, Buford Bond January 1975 (has links)
M. S.
107

Investigation of Factors Affecting Fertility: Chromosome Segregation Errors and Environmental Toxins

Jackson, Jodi Michelle 11 June 2007 (has links)
No description available.
108

Sanitizer efficacy towards attached bacteria in a simulated milk pipeline system using pure and mixed cultures

Mosteller, Tracy M. 06 August 2007 (has links)
The efficacy of six sanitizers, [chloline (200 ppm), iodophor (2S: ppm), acid anionic (200 ppm), peracetic acid (200 ppm), and fatty acid sanitizer (200 ppm)], was evaluated against bacteria attached to gasket materials. Pseudomonas fluorescens, Yersinia enterocolitica, Bacillus cereus, and Listeria monocvtogenes were capable of significant attachment to both buna-N nlbber and Teflon® gasket surfaces in either pure or mixed cultures. Differences in initial attachment rates were evident in a mixed culture of P. fluorescens, Y. enterocolitica, and Listeria monocytogenes in vitro. Sanitizer effectiveness depended upon the bacterium being enumerated, the type of surface, if the bacterium was attached in pure culture or as part of a mixed culture, and the system of evaluation, (i.e. whether or not sanitizer was used alone or as part of a cleaning system). Peracetic acid was the most effective. Removal of bacteria was more pronounced on the Te'f1on® surface with all sanitizers used. The cleaning system, which consisted of a pre-rinse with warm water, application of the cleaning solution, post-rinse with warm water, and application of the sanitizing solution, allowed microorganisms to remain, when the bacteria were present as a pure culture, but resulted in the complete removal of bacteria in mixed culture. / Ph. D.
109

Disinfection of secondary treated sewage by chlorine in a continuous flow reactor

Heller, Buford Bond January 1975 (has links)
The purpose of this study was to determine the amount of residual chlorine that was necessary to adequately disinfect secondary treated sewage in a continuous flow reactor. Trickling-filter, clarified effluent collected prior to chlorination at the plant site was filtered sterilized and inoculated with two bacteria commonly found in sewage--Escherichia coli and Streptococcus faecalis. Eight different chlorine residuals were evaluated for contact times of 10, 20 and 30 minutes. The results indicated that the chlorine residuals needed to obtain 99.9% kill of E. coli and S. faecalis were 1.95 and 2.40 mg/1, respectively. The data showed that S. faecalis was more resistant to chlorine than was E. coli. Time of contact rather than chlorine residual concentration was determined to be more important in influencing chlorine effectiveness. / M.S.
110

Analysis of disinfection by products in drinking water by solid phase extraction

Sexton, Diane Lynne 12 September 2009 (has links)
The objectives of this research were to develop a broad spectrum method for the extraction, concentration, and analysis of drinking water disinfection by products using solid phase extraction (SPE), and to determine if this method had lower detection limits and less variability than the proposed liquid-liquid extraction method, EPA Method 551. The disinfection by products investigated were halogenated nitriles, ketones, and aldehydes. The SPE method extracted and concentrated samples using the C-18 Empore Extraction Disks, and desorbed the analytes with methyl-tert-butyl ether (MTBE) as a solvent. The results showed that with the SPE method the recoveries were low (0-50%) for most compounds, and the limit of detection (LOD) values were in the range of 0.2 to 50 ug/L, which were much higher than those for EPA Method 551. The variability was also higher than for EPA Method 551. The SPE method also appeared to be concentration dependent; the recoveries decreased as analyte concentration increased. Highly saline conditions (250 g/L NaCl) resulted in low recoveries and concentration dependencies for some compounds. Even though the SPE method was easier and faster, the lower method detection limit (MDL) values and lower variability made Method 551 more preferable. Further analysis of the SPE method using a new cyclohexyl disk was also recommended. / Master of Science

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