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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.
1

Využití hloubkového kypřiče při pěstování obilovin a řepky olejné

MICHEK, Aleš January 2019 (has links)
The diploma thesis deals with the comparison of two technologies for soil cultivation in winter rape and winter wheat growing in 2017 and 2018. The first technology is a conventional technology, or classic using plowing and the second one is a minimization technology, where plowing is replaced by loosening. The work is focused on the comparison of fuel consumption, investment and operating costs, exploitative indicators and machine work quality. Furthermore, the thesis is focused on the description of particular machines and the company of primary agricultural production, where the machine is used.
2

New Seismic Design Approaches For Block Type Quay Walls

Karakus, Hulya 01 July 2007 (has links) (PDF)
In this study, new design approaches are introduced for the seismic design of block type quay walls after reviewing the conventional methodologies. Within the development of the new design approaches an inverse triangular dynamic pressures distributions are applied to define both seismic earth pressures and seismic surcharge pressures. Differently from the conventional design methodology, the hydrodynamic forces are taken into consideration while dynamic forces are specified and equivalent unit weight concept is used during the both static and dynamic calculations Compatibility of this new design approaches are tested by case studies for the site and it is seen that the numerical results are in good agreement qualitatively with field measurements.
3

Comparação dos métodos microbiológico convencional, imunoanálise e reação da polimerase em cadeia (PCR) no monitoramento de Salmonella sp. em frangos durante o abate / Comparison of the standard microbiological method, immunoanalysis and polymerase chain reaction (PCR) for monitoring Salmonella sp. in chicken during the slaughter

Ruckert, Dimitri Aleksander Saldanha Von 27 July 2006 (has links)
Made available in DSpace on 2015-03-26T13:46:59Z (GMT). No. of bitstreams: 1 texto completo.pdf: 406137 bytes, checksum: 691c5cada5b56820bfd7b97686fb4cbc (MD5) Previous issue date: 2006-07-27 / In this study, the standard microbiological method, immuno-analysis and polymerase chain reaction - PCR were evaluated using, respectively, 135, 70 and 90 carcass samples, distributed into five different slaughter stages of a poultry slaughterhouse. The comparison of the Salmonella sp. contamination frequency among the different slaughter stages and the comparison of the detection efficiency among the three methods were evaluated, considering the possible use as a monitoring tool for the Hazard Analysis and Critical control Points program (HACCP). The whole three methods were compared by the Qui-Squared test (χ2), obtaining a value of 18.51 (p ≤ 0.01). These methods also were compared two by two, to quantify the Odds Ratio (OR). Was obtained a χ2 = 8.72 (p ≤ 0.01), when were compared the positive results of the immuno-analysis and the Standard Microbiological ones; and the OR calculated was 3.34 (IC: 1.36 8.32). When comparing the positive results of PCR and the standard microbiological ones, were obtained χ2 of 18.37 (p ≤ 0.01) and OR = 4.83 (IC: 2.13 11.15). The same didn t happen when comparing the PCR and immuno-analysis methods. These, comparing to the standard microbiological technique, were considered more efficient e suitable methods for utilization as monitoring tools for HACCP. The slaughter stage localized after the chiller (Point E) shows itself as the most suitable as a critical control point, because it was less contaminated and takes over a strategic position at the end of the slaughter line. / Foram avaliados neste estudo os métodos convencional, imunoanalítico e por reação de polimerase em cadeia PCR para a pesquisa de Salmonella sp. em, respectivamente, 135, 70 e 90 amostras de carcaças de frangos, distribuídas em cinco diferentes etapas de abate em um abatedouro. Procedeu-se a comparação da freqüência de detecção de Salmonella sp. das carcaças nas diferentes etapas de abate, e da eficiência de detecção dos três métodos, visando a indicação de método alternativo para o monitoramento no programa de Análise de Perigos e Pontos Críticos de Controle (APPCC). Os resultados foram comparados pelo teste do Qui-quadrado (χ2), obtendo um valor 18,51 (p ≤ 0,01) na análise conjunta dos três métodos avaliados. Tais métodos também foram comparados, dois à dois, para a quantificação das chances de detecção de cada um pela Razão de Chances ou Odds Ratio (OR). Obteve-se um χ2 = 8,72 (p ≤ 0,01), comparando-se os resultados positivos obtidos pelo sistema imunoanalítico com os do método microbiológico convencional, sendo a OR igual a 3,34 e Intervalo de Confiança (IC) entre 1,36 e 8,32. Também houve diferença estatística com um χ2 de 18,37 (p ≤ 0,01) entre os resultados positivos totais da PCR e do método microbiológico convencional, sendo a OR igual a 4,83 (IC: 2,13 - 11,15). O mesmo não ocorreu entre os métodos PCR e imunoanalítico. Estes dois, quando comparados com a microbiologia convencional, foram considerados mais eficientes e adequados para a utilização em monitoramento no APPCC. A etapa de abate localizada após o pré-resfriamento (ponto E) foi considerada a mais adequada como ponto crítico de controle por apresentar a menor contaminação e por assumir uma posição estratégica no final da linha de abate.
4

Preparo e avaliação de material de referência para análise de Salmonella / Preparation and evaluation of reference material for Salmonella analysis

Silva, Carolina dos Santos Fernandes da 18 June 2008 (has links)
Made available in DSpace on 2015-03-26T13:51:52Z (GMT). No. of bitstreams: 1 texto completo.pdf: 738414 bytes, checksum: 553ba8cf81504abac249e2eb5a629a5d (MD5) Previous issue date: 2008-06-18 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The use of Reference Material (RM) in microbiological food analyses increased around the world, mainly with the introduction of quality control and management programs in laboratories. The necessity of the standardization of analysis methods makes the demand for this type of material increase which allows the determination of precision and repeatability of the experimental data. This study aimed to prepare microbiological RMs for quantitative and qualitative analyses of Salmonella, to evaluate the homogeneity and stability of the material during storage time and to compare the sensitivity of the Salmonella detection methods. The study was performed in two stages. The first with RM containing approximately 103 CFU/ g of Salmonella cells, submitted or not to starvation and storage conditions, up until 240 days, at -20 °C. The second stage consisted of the RM preparation containing approximately 10 CFU/ g for comparison of the methodology sensibility of Salmonella detection in food. The RM homogeneity and stability containing approximately 103 CFU/ g was evaluated through the T1 statistical test, analysis of linear regression and proficiency test, while the RM performed with a low number of Salmonella cells was evaluated by the T2 statistical test and by the Epiinfo program of the Center for Disease Control (CDC) of the USA for the evaluation of the detection methods of Salmonella in this material. The T1 statistical test for the RM prepared with 103 CFU/ g demonstrated superior values to the recommended ones for this type of material, which indicated the necessity for new studies for the improvement of the Salmonella resistance to the dehydration and storage conditions. However, the same material presented itself homogeneous in the proficiency test performed by three different laboratories, when the σp value was obtained until 25 % as recommended by the Food Examination Performance Assessment Scheme (FEPAS) of the United Kingdom. In the linear regression analysis, no significant difference was noted between the RMs produced with and without stressed cells, in spite of the decline tendency of the number of Salmonella cells in the material made without stressed cells being obvious after 240 storage days at -20 °C. For the RM prepared with 10 CFU/ g, the T2 statistical test presented acceptable results, after 60 storage days at 4 °C. One gram servings of this RM were evaluated by three analytical methodologies which included the conventional method, the immunoanalytical method VIDAS® and automated PCR, by the BAX system. The results were consistent in all the analyzed samples in the first two methods, with a Kappa rate equal to 1. The PCR method presented an agreement in approximately 95 % to the conventional methodology, with a Kappa rate equal to 0.64. False-negative results were observed in 5% of the analyzed samples, when the PCR method was used. However, this result does not compromise the technique sensibility. This study demonstrated advantages of the quick methodology use of Salmonella detection in food, which offers, besides greater speed and practicality forgetting results, similar sensitivity to the conventional method recommended by Brazil´s Ministry of Agriculture. / A utilização de Material de Referência (MR) na análise microbiológica de alimentos aumentou em todo o mundo, principalmente com a implantação de programas de controle e gestão da qualidade em laboratórios. A necessidade de padronização de métodos de análise faz aumentar a demanda por este tipo de material que permite determinar a precisão e repetibilidade dos dados experimentais. Este estudo teve como objetivo preparar MRs microbiológicos para análises quantitativa e qualitativa de Salmonella, avaliar a homogeneidade e estabilidade ao longo do tempo de estocagem e comparar a sensibilidade dos métodos de detecção de Salmonella. O estudo foi conduzido em duas etapas, a primeira com MR contendo, aproximadamente, 103 UFC/ g de células de Salmonella, submetidas ou não a condições de estresse nutricional e estocadas, por até 240 dias, a -20 °C. A segunda etapa consistiu no preparo de MR contendo, aproximadamente, 10 UFC/ g para comparação da sensibilidade das metodologias de detecção de Salmonella em alimentos. A homogeneidade e a estabilidade do MR contendo, aproximadamente, 103 UFC/ g foram avaliadas por meio do teste estatístico de T1, análise de regressão linear e ensaio de proficiência, enquanto que o MR feito com baixo número de células de Salmonella foi avaliado pelo teste estatístico de T2 e por meio do programa Epiinfo do Centro de Prevenção e Controle de Doenças dos EUA (CDC) para avaliação dos métodos de detecção de Salmonella neste material. O teste estatístico de T1 para o MR preparado com 103 UFC/ g demonstrou valores superiores aos recomendados para este tipo de material, o que indicou a necessidade de realização de novos estudos para melhoria da resistência de Salmonella às condições de desidratação e de estocagem. No entanto, o mesmo material apresentou-se homogêneo no ensaio de proficiência realizado por três diferentes laboratórios, obtendo-se o valor de σp de até 25 % como recomendado pelo Esquema de Avaliação de Desempenho na Análise de Alimentos do Reino Unido (FEPAS). Na análise de regressão linear constatou-se não haver diferença significativa entre os MRs produzidos com e sem células estressadas, apesar de ter sido evidente a tendência de declínio do número de células de Salmonella no material feito sem células estressadas, após 240 dias de estocagem a -20 °C. Para o MR preparado com 10 UFC/ g, o teste estatístico de T2 evidenciou resultados aceitáveis, após 60 dias de estocagem a 4 °C. Porções de 1 g deste MR foram avaliadas por três metodologias analíticas que incluíram o método convencional, o método imunoanalítico VIDAS® e PCR automatizado, pelo sistema BAX. Os resultados foram concordantes em todas as amostras analisadas nos dois primeiros métodos, com índice de Kappa igual a 1. O método de PCR apresentou concordância em aproximadamente 95 % com a metodologia convencional, com índice de Kappa igual a 0,64. Resultados falso-negativos foram observados em 5 % das amostras analisadas, quando utilizado o método de PCR, no entanto, este resultado não compromete a sensibilidade da técnica. Neste trabalho foram destacadas as vantagens do uso de metodologias rápidas de detecção de Salmonella em alimentos, que oferecem além de maior rapidez e praticidade para obtenção dos resultados, sensibilidade semelhante ao método convencional recomendado pelo Ministério da Agricultura, Pecuária e Abastecimento do Brasil.
5

Quantitative thermal performance assessment of building envelopes – emergent practices and infrared thermography

Mahmoodzadeh, Milad 25 January 2022 (has links)
Since many buildings in Canada were built prior to the advent of national and provincial energy codes and standards, quantifying building envelope thermal performance in existing buildings is an important step in identifying retrofit opportunities. Due to the lack of building codes or standards for existing buildings in Canada, development of a rapid and robust quantitative approach to evaluate and rank buildings for vertical envelope retrofits is required. Hence, this dissertation sought to develop quantitative approaches to evaluate existing building envelope thermal performance in Canada and beyond. Following current professional practices, in Chapter 1, a comprehensive study was conducted on 49 campus buildings at the University of Victoria (UVic) to evaluate potential energy savings from vertical envelope retrofits, and to further validate those savings through more detailed energy models and parametric analyses for a subset of buildings. To this end, the thermal performance of a building envelope was quantified based on its heat loss coefficient (UA), obtained from multiplying its surface area (A) by its thermal transmittance (U-value). Heat loss calculations were used as a metric to inform envelope rehabilitation prioritization, while considering other data such as age and physical condition in parallel. Archetype energy models for selected buildings were used to evaluate the impacts of envelope retrofits on energy and GHG savings. The outcomes of this study allowed the University to weigh the benefits of improved energy performance from envelope retrofits against associated capital cost expenditures. Also, the implemented methodology and studied parameters unveiled a new horizon in evaluating the thermal performance of existing building envelopes in Canada, where a building code for existing buildings has not yet been established. Considering the economic findings of the envelope retrofits studied, it was concluded that in the absence of an existing building energy code, the University would likely require additional incentives, such as higher utility costs, higher carbon taxes, or qualifying for utility incentive programs to justify improving existing building envelope performance on the basis of energy only. The strength of the proposed methodology in Chapter 1 was in its balance of effort and ultimate decision-making utility, where reasonable thermal bridging approximations based on simulation models for existing buildings can yield data accurate enough to inform a ranking exercise on a large breadth of subject buildings. However, since numerical models do not consider degradation of building materials, real moisture content, and errors associated with manufacturing and installation, actual building envelope thermal performance differs from 3D simulation models. To study this limitation, in-situ thermal assessments of building envelopes were performed to quantify their actual thermal performances. To this end, Chapters 2 to 4 of this dissertation attempted to determine the viability of an external infrared thermography (IRT) survey technique for quantification of heat losses through the opaque building envelope, and also explores its potential application in identifying and comparing sources of air leakage. The experiments were performed on wood-framed wall assemblies commonly used in Canada due to growing interest among designers, builders, and governments to encourage the use of wood as a building material. In these studies, (Chapter 2 to Chapter 4), thermal transmittances (U-values) of wall assemblies were estimated with external IRT and compared with 3D computer simulations. Furthermore, the impact of the accuracy of U-values estimated with IRT on the deviation of energy simulation outputs with metered data was examined. Finally, a novel relative quantitative infrared index (IRI) was proposed as a means to facilitate rapid evaluation and subsequent ranking of building envelope thermal performance. From the experiments in Chapters 2 & 3, it was found that the U-values obtained with IRT were comparable with simulated values suggesting IRT can be a reliable tool for estimating the thermal performance of wood-framed wall assemblies. Results also demonstrated that thermal imaging artefacts including nonlinear characteristics of infrared (IR) camera focal array, a.k.a. non-uniformity corrections (NUC) and vignetting could have a substantial influence on the accuracy of results, in particular energy model outputs. This limitation was resolved by introducing a practical approach where thermal images were taken from different incident angle. Overall, IRI was found to be a reliable metric for relative quantitative comparison of building envelope thermal performance regardless of boundary conditions. Moreover, outcomes of the IRT air leakage study in Chapter 4 indicated that combined qualitative and quantitative IRT approaches could potentially be implemented by practitioners to identify sources of air leakage and thermal bridges in buildings and compare their relative severity. Since blower door testing is gradually being introduced as a building code requirement to measure building envelope airtightness in an increasing number of Canadian jurisdictions, performing IRT simultaneously is potentially valuable exercise in this context. Ultimately, the methodologies outlined in Chapters 2 to 4 can help decision-makers to characterize building envelope retrofits from a performance perspective, and potentially serve as a basis for governments to develop policies to improve existing building energy performance. The methodologies in Chapters 2 to 4 prompted opportunities to utilize the emergent technology of small unmanned aerial vehicles (UAVs) equipped with an infrared camera for quick thermal assessments of building envelopes. The last chapter of this dissertation, Chapter 5, outlines advantages and limitations of aerial IRT (UAV-IRT) surveys compared to conventional stationary IRT. Furthermore, a set of best practices for UAV-IRT were presented to minimize dynamic measurement uncertainty. It was concluded that with the current IR camera technology, aerial surveys for quantitative thermal assessment of building envelope are not as accurate as with conventional infrared thermography; further investigations by manufacturers and researchers are recommended. / Graduate
6

Presevation of boer goat semen in liquid nitrogen vapour in comparison to the conventional freezing method using different extenders, freezing and thawing regimes

Kalobo, Kidinda 18 May 2018 (has links)
MSCAGR (Animal Science) / Department of Animal Science / The Boer goat (Capra hircus) is one of the most desirable goat breeds for meat production. The impact of cryopreservation on the viability of its semen depends on the extenders, freezing and thawing methods. This study evaluated the effects on sperm viability in Boer goat semen extended using Bioxcell, Biladyl and Ham’s F10, and frozen in semen straws placed on a rack at 4, 5, 6 or 7 cm above the surface of liquid nitrogen. After storage in liquid nitrogen for 7 days, the frozen semen was thawed at 37 oC for 30 seconds or 90 oC for 5 seconds. Samples of sperm were also frozen to -196 oC in a programmable freezer, as the control regime for the freezing treatments. Sperm morphology, motility and viability were evaluated using the computer aided sperm analysis (CASA) system in a randomised design in which the treatments were in a 3 (extender) X 5 (freezing regime) and X 2 (thawing regime) factorial arrangement. The extenders Bioxcell and Biladyl were affected in the total motility, progressive motility and static (P<0.01), the motility was overall maintained only in straws placed at 5 cm above the liquid nitrogen level, with significant difference for the interaction extender X freezing regime in the total motility (p<0.01), non-progressive motility (p<0.05) and progressive motility (p<0.01), the 37 oC for 30 sec thawing regime had significantly more (P<0.05) in cut-head spermatozoa. Ham’s F10 extender had significantly lower normal spermatozoa (P<0.05) compare to Biladyl and Bioxcell extenders. In conclusion, the extender type, freezing and thawing regime were important factors for consideration in goat semen / NRF

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