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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.
181

Conservação de sementes de açaí (Euterpe oleracea Mart.) / Conservation of Euterpe oleracea seeds

Walnice Maria Oliveira do Nascimento 10 March 2006 (has links)
Sementes de Euterpe oleracea são consideradas recalcitrantes e demandam ampliação do conhecimento sobre os fatores que interferem na sua conservação. Diante disso, o presente trabalho objetivou verificar os efeitos do grau de umidade da semente e da temperatura do ambiente na manutenção da qualidade dessas sementes. Sementes da cultivar BRS Pará, com teores de água de 43,4%, 37,4%, 30,3%, 26,1%, 21,0%, 15,1% e 11,9%, acondicionadas em sacos de polietileno, foram armazenadas sob temperaturas de 20ºC, 15ºC e 10ºC, durante 360 dias e submetidas a avaliações periódicas do grau de umidade, da germinação, do vigor e da sanidade. A desidratação até 37,4% de água não produz efeitos imediatos sobre a germinação e o vigor das sementes. A partir de 37,4% de água, a dessecação favorece, progressivamente, a deterioração das sementes e ao atingirem 15,1% as sementes não germinam. Após o armazenamento, sementes com 21,0% de água ou menos têm a germinação anulada, independentemente da temperatura. A associação de 43,4% de água na semente e o armazenamento em ambiente a 20ºC, favorece a conservação das sementes por até 270 dias. / Seeds of Euterpe oleracea Mart. are considered recalcitrant and demand enlargement of the knowledge about the factors that interfere in its conservation. The present work aimed to verify the effects on seed moisture content and of the atmosphere temperature in the maintenance of seed quality. Seeds of cultivar BRS Pará, with moisture content of 43,4%, 37,4%, 30,3%, 26,1%, 21,0%, 15,1% and 11,9%, conditioned in polyethylene bags, were stored under controlled temperature at 20ºC, 15ºC and 10ºC, for 360 days, and submitted to periodic evaluations of the moisture content, germination, vigor and the health condition. The dehydration up to 37,4% of water does not produce immediate effects on the germination and vigour. However, after 37,4% it progressively favors the deterioration, and when reaching 15,1% the physiologic performance is annulled. After the storage, seeds with 21,0% of water or less have the germination annulled, independently of the temperature. It was verified that the association of seeds with 43,4% of water and the storage at 20ºC support the conservation of the seeds up to 270 days.
182

Condições de armazenamento e conservação do potencial fisiológico de sementes de diferentes genótipos de milho / Storage conditions and seed performance of different corn genotypes

Tathiana Silva Timóteo 20 April 2011 (has links)
A conservação do potencial fisiológico de sementes durante armazenamento depende de vários fatores, dentre os quais o genótipo e as condições de ambiente. Empresas produtoras de sementes de milho têm demonstrado séria preocupação com variações na longevidade de sementes de diferentes híbridos, que podem não apresentar o desempenho desejado, tanto na época normal de semeadura como na semeadura de safrinha. Visando contribuir para o esclarecimento do problema, este trabalho foi conduzido com o objetivo de avaliar os efeitos de ambientes de armazenamento sobre o potencial fisiológico de sementes de diferentes genótipos de milho, procurando identificar causas de possíveis alterações fisiológicas e diferenças em seu desempenho. Foram avaliadas sementes de três híbridos experimentais de milho, cada um representado por três lotes produzidos pela empresa Syngenta Seeds, armazenados durante quinze meses, em três ambientes: câmara fria e seca (10 ºC e 30 % de umidade relativa do ar), laboratório e ambiente controlado (20 ºC e 70 % de umidade relativa do ar). O desempenho das sementes foi avaliado em épocas trimestrais, por meio de testes de germinação, envelhecimento acelerado, frio e emergência de plântulas em campo. Foi também determinada a atividade dos sistemas enzimáticos superóxido dismutase (SOD), catalase (CAT), esterase (EST), malato desidrogenase (MDH), álcool desidrogenase (ADH), glutamato oxalacetato transaminase (GOT), glutamato desidrogenase (GTDH), -amilase (-AM) e sorbitol desidrogenase (SDH), por meio da técnica de eletroforese. Verificou-se que o potencial de armazenamento de sementes de diferentes genótipos de milho é avaliado, com segurança, associando-se resultados de testes de germinação e de vigor com avaliações da atividade de isoenzimas. Alterações em sistemas isoenzimáticos álcool desidrogenase, catalase, esterase, -amilase e sorbitol desidrogenase permitem identificar o progresso do processo de deterioração de sementes de milho e o estabelecimento de causas de diferenças no desempenho de genótipos e lotes de sementes. O armazenamento sob condições sub-ótimas de temperatura e umidade relativa do ar é adequado para promover diferenças na intensidade e velocidade de deterioração de sementes de genótipos de milho. / Seed storability is affected by several factors including genotype and environmental conditions. Corn seed producers are highly concerned with variations in seed longevity of different hybrids, resulting in lower performance than desired during the normal sowing season as much as during off season times. The objective of this research was to evaluate the effect of storage conditions on the seed physiological potential of different corn genotypes to identify possible causes of changes in seed performance. Three experimental corn hybrids each represented by three seed lots produced by Syngenta Seeds were evaluated. Seeds were stored for fifteen months under three environments: cold and dry chamber (10ºC and 30% relative air humidity), laboratory, and controlled environment (20ºC and 70% relative air humidity). Seed performance was evaluated every three months by germination, accelerated aging and cold tests as well as field seedling emergence. Activity of the enzymatic systems superoxide dismutase (SOD), catalase (CAT), esterase (EST), malate dehydrogenase (MDH), alcohol dehydrogenase (ADH), glutamate oxalacetate transaminase (GOT), glutamate dehydrogenase (GTDH), -amilase (-AM) and sorbitol dehydrogenase (SDH) was also determined using electrophoresis. The storability of corn seeds from different genotypes can be consistently evaluated by associating germination and vigor test results with isoenzymatic activity. Changes in alcohol dehydrogenase, catalase, esterase, -amilase and sorbital dehydrogenase isoenzymatic systems can identify the progress of seed deterioration in corn and establish causes of differences in performance among seed genotypes and lots. Storage under sub-optimal temperature and relative air humidity is an efficient procedure to provoke differences in intensity and speed of seed deterioration in corn seeds of different genotypes.
183

Can meso-level simulation increase medical students' confidence in recognising and responding to clinical deterioration in adult hospital patients?

Hogg, George January 2015 (has links)
Recognising Acute Deterioration: Active Response (RADAR) is a simulation based teaching session using simulated patients to portray acutely unwell adult hospital patients. The genesis, development and progress of RADAR will be discussed along with the findings of questionnaires and focus groups from two further cycles of action research. Readers will become aware of the impact which RADAR makes to the evidence and learning surrounding the recognition and assessment of clinical deterioration in adult hospital patients. The study investigated the impact of simulation on medical students’ confidence in recognising and responding to clinical deterioration in adult hospital patients using simulation, simulated patients and moulage (make-up).
184

Fungos em bibliotecas: frequência dos gêneros em livros e elaboração de teste para avaliação da biorreceptividade em papéis. / Fungi in libraries: genera frequency in books and test development for evaluation of paper bioreceptivity.

Menezes, Adriana Araujo Reis 24 June 2009 (has links)
Em bibliotecas, a grande concentração de matéria orgânica, associada a uma climatização deficiente propicia um ambiente favorável ao crescimento fúngico. O objetivo deste trabalho é desenvolver um teste para detectar a biorreceptividade ao crescimento fúngico de papéis utilizados na confecção de livros. Os gêneros de fungos foram amostrados nos períodos do inverno e verão, em seis bibliotecas da Universidade de São Paulo, três com climatização artificial e três sem. Não houve diferença no número de gêneros encontrados entre as bibliotecas com e sem climatização artificial, mas o inverno mostrou maior diversidade que o verão. Os fungos Cladosporium, Aspergillus, Chaetomium e Trichoderma foram inoculados em quatro tipos de papéis e estes foram testados em câmaras com 95% e 100% de umidade relativa, a 25 oC, por 30 dias. O crescimento ou não dos fungos nos papéis foi avaliado, assim como a alteração de cor. Nas condições do teste conclui-se que o melhor crescimento ocorreu com Cladosporium, na concentração de 106cél/mL e umidade relativa de 100%. / Libraries are very propitious environments for the growth of fungi. The great concentration of organic material available for these microorganisms, and often the lack of adequate ventilation or climate control, favors this situation. The main aim of this study is to develop a test to detect fungal growth bioreceptivity in papers used in books. Firstly, fungi genera where sampled in the summer and winter in six libraries of University of São Paulo, three with artificial acclimatization and three without. There was no difference in number between the libraries with and without artificial acclimatization but the diversity was higher in the winter than in the summer. Cladosporium, Aspergillus, Trichoderma and Chaetomium where inoculated in papers and tested in chambers with 95% and 100% of relative humidity, at 25°C for 30 days. The fungal growth was evaluated, as well the color alteration. The conclusion based on the tests is that the highest growth occurred with Cladosporium, with 106 cel/mL concentration and relative humidity of 100%.
185

Condições de armazenamento e conservação do potencial fisiológico de sementes de diferentes genótipos de milho / Storage conditions and seed performance of different corn genotypes

Timóteo, Tathiana Silva 20 April 2011 (has links)
A conservação do potencial fisiológico de sementes durante armazenamento depende de vários fatores, dentre os quais o genótipo e as condições de ambiente. Empresas produtoras de sementes de milho têm demonstrado séria preocupação com variações na longevidade de sementes de diferentes híbridos, que podem não apresentar o desempenho desejado, tanto na época normal de semeadura como na semeadura de safrinha. Visando contribuir para o esclarecimento do problema, este trabalho foi conduzido com o objetivo de avaliar os efeitos de ambientes de armazenamento sobre o potencial fisiológico de sementes de diferentes genótipos de milho, procurando identificar causas de possíveis alterações fisiológicas e diferenças em seu desempenho. Foram avaliadas sementes de três híbridos experimentais de milho, cada um representado por três lotes produzidos pela empresa Syngenta Seeds, armazenados durante quinze meses, em três ambientes: câmara fria e seca (10 ºC e 30 % de umidade relativa do ar), laboratório e ambiente controlado (20 ºC e 70 % de umidade relativa do ar). O desempenho das sementes foi avaliado em épocas trimestrais, por meio de testes de germinação, envelhecimento acelerado, frio e emergência de plântulas em campo. Foi também determinada a atividade dos sistemas enzimáticos superóxido dismutase (SOD), catalase (CAT), esterase (EST), malato desidrogenase (MDH), álcool desidrogenase (ADH), glutamato oxalacetato transaminase (GOT), glutamato desidrogenase (GTDH), -amilase (-AM) e sorbitol desidrogenase (SDH), por meio da técnica de eletroforese. Verificou-se que o potencial de armazenamento de sementes de diferentes genótipos de milho é avaliado, com segurança, associando-se resultados de testes de germinação e de vigor com avaliações da atividade de isoenzimas. Alterações em sistemas isoenzimáticos álcool desidrogenase, catalase, esterase, -amilase e sorbitol desidrogenase permitem identificar o progresso do processo de deterioração de sementes de milho e o estabelecimento de causas de diferenças no desempenho de genótipos e lotes de sementes. O armazenamento sob condições sub-ótimas de temperatura e umidade relativa do ar é adequado para promover diferenças na intensidade e velocidade de deterioração de sementes de genótipos de milho. / Seed storability is affected by several factors including genotype and environmental conditions. Corn seed producers are highly concerned with variations in seed longevity of different hybrids, resulting in lower performance than desired during the normal sowing season as much as during off season times. The objective of this research was to evaluate the effect of storage conditions on the seed physiological potential of different corn genotypes to identify possible causes of changes in seed performance. Three experimental corn hybrids each represented by three seed lots produced by Syngenta Seeds were evaluated. Seeds were stored for fifteen months under three environments: cold and dry chamber (10ºC and 30% relative air humidity), laboratory, and controlled environment (20ºC and 70% relative air humidity). Seed performance was evaluated every three months by germination, accelerated aging and cold tests as well as field seedling emergence. Activity of the enzymatic systems superoxide dismutase (SOD), catalase (CAT), esterase (EST), malate dehydrogenase (MDH), alcohol dehydrogenase (ADH), glutamate oxalacetate transaminase (GOT), glutamate dehydrogenase (GTDH), -amilase (-AM) and sorbitol dehydrogenase (SDH) was also determined using electrophoresis. The storability of corn seeds from different genotypes can be consistently evaluated by associating germination and vigor test results with isoenzymatic activity. Changes in alcohol dehydrogenase, catalase, esterase, -amilase and sorbital dehydrogenase isoenzymatic systems can identify the progress of seed deterioration in corn and establish causes of differences in performance among seed genotypes and lots. Storage under sub-optimal temperature and relative air humidity is an efficient procedure to provoke differences in intensity and speed of seed deterioration in corn seeds of different genotypes.
186

Effects of Hydro-Cooling, Chemicals, and Packaging Treatments on Refrigerated-Life and Quality of Sweet Cherries and in vitro Effects of Chemicals on Selected Fungi Responsible for Fruit Deterioration

Do, Joseph Yungsheng 01 May 1964 (has links)
As the population tends to urbanize, the potential consumer market of fresh produce becomes distant from the producing farm. This distance brings to growers and handlers the problems of how to keep their fresh products unspoiled after harvest and during transit period of shipping, and how they can be delivered to the specified destination without substantial deterioration. It is the common interest of fruit growers, shippers, wholesalers, and retailers that the shelf-life of fresh fruit be prolonged to increase sales. Sweet cherries are one of the important fruit crops in Utah. Being highly perishable, fresh sweet cherries have relatively short storage life after harvest . It is known that the approximate limit for the successful commercial storage of fresh sweet cherries is about 10 days to 2 weeks only. A practicable measure for extending this storage limit has to be established so that the market may have fresh sweet cherries over a longer season and also be able to balance the time of plenty and the time of scarcity. Furthermore, the Utah grown cherries may find new outlets in the distant market. Thus the benefit will be shared by the grower, the seller, and the consumer. Metabolic breakdown and fungal deterioration are the two important factors which cause the spoilage of fruits. Studies have shown that with many perishable produces, precooling -- the prompt application of refrigeration prior 2 to normal storage or transportation is the key to successful storage. Hydro -cooling treatment is considered to be advantageous especially in Utah, where high temperature and low relative humidity predominate during the harvest season of sweet cherries. Post-harvest chemical and packaging treatments of sweet cherries are possible approaches on ext ending the keeping quality of the fruits concerned. With some of the antifungal agents available today, the fungi which cause fruit decay might be successfully controlled. As a matter of fact, new fungicides, antifungal antibiotics, and packaging films are continuously developed by the industries in the United States. Appropriate combination of these newly developed materials with hydro-cooling followed by refrigerated storage, coupled with in vitro study of the effects of chemicals on fruit decay organisms, might lead to an improvement in the storage life of sweet cherries. It was with this idea in mind that experiments were conducted to study the effects of hydro-cooling, chemicals, and packaging treatments on preserving fresh sweet cherries and also in vitro effects of chemicals on certain fungi responsible for fruit deterioration.
187

Prevention of Pigment Deterioration and Lipid Oxidation in Ground Beef and Pork

Jayasingh, Preetha 01 May 2004 (has links)
Fresh beef was modified-atmosphere packaged in carbon monoxide or oxygen to prolong red surface color. After comparison of several packaging method using carbon monoxide, steaks pretreated with 5% carbon monoxide for 24 hours and then vacuum packaged had the best combination of color and microbial stability (5 weeks), with the least potential for carbon monoxide inhalation. In the evaluation of ground beef in high-oxygen, modified-atmosphere-packaging, thiobarbituric-acid numbers increased over time, and the flavor was disliked slightly after 6 or 10 days of storage at 2° Celsius. The antioxidant effect of milk-mineral was tested in raw and cooked ground pork stored refrigerated or frozen. Thiobarbituric-acid numbers were low for all raw treatments. For cooked ground pork, thiobarbituric-acid numbers were lower for samples with milk-mineral or sodium-tripolyphosphate, compared to control or samples with butylated-hydroxytoluene. Sodium-tripolyphosphate, a type 2 antioxidant (iron chelator), was also very effective in preventing heme degradation during refrigerated storage.
188

Road Crack Condition Performance Modeling Using Recurrent Markov Chains And Artificial Neural Networks

Yang, Jidong 17 November 2004 (has links)
Timely identification of undesirable pavement crack conditions has been a major task in pavement management. Up to date, myriads of pavement performance models have been developed for forecasting pavement crack condition with the traditional preferred techniques being the use of regression relationships developed from laboratory and/or field statistical data. However, it becomes difficult for regression techniques to predict the crack performance accurately and robustly in the presence of a variety of tributary factors, high nonlinearity, and uncertainty. With the advancement of modeling techniques, two innovative breeds of models, Artificial Neural Networks and Markov Chains, have drawn increasing attention from researchers for modeling complex phenomena like the pavement crack performance. In this study, two distinct models, a recurrent Markov chain, and an Artificial Neural Network (ANN), were developed for modeling the performance of pavement crack condition with time. A logistic model was used to establish a dynamic relationship between transition probabilities associated with the pavement crack condition and the applicable tributary variables. The logistic model was then used conveniently to construct a recurrent Markov chain for use in predicting the crack performance of asphalt pavements in Florida. Florida pavement condition survey database were utilized to perform a case study of the proposed methodologies. For comparison purpose, a currently popular static Markov chain was also developed based on a homogeneous transition probability matrix that was derived from the crack index statistics of Florida pavement survey database. To evaluate the model performance, two comparisons were made; (1) between the recurrent Markov chain and the static Markov chain; and (2) between the recurrent Markov chain and the ANN. It is shown that the recurrent Markov chain outperforms both the static Markov chain and the ANN in terms of one-year forecasting accuracy. Therefore, with high uncertainty typically experienced in the pavement condition deterioration process, the probabilistic dynamic modeling approach as embodied in the recurrent Markov chain provides a more appropriate and applicable methodology for modeling the pavement deterioration process with respect to cracks.
189

Procedures for diagnosis and assessment of concrete buildings / Wen-Gang Hua

Hua, Wen-Gang January 1993 (has links)
Bibliography: leaves 213-234 / xviii, 234, 13 leaves ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Faculty of Engineering (Civil), 1994?
190

Sensitivity of Hashin damage parameters for notched composite panels in tension and out-of-plane bending

Wright, Thomas J. (Thomas John) 20 November 2012 (has links)
When using Finite Element Analysis (FEA) to model notched composite panels, the values of certain material properties can have a great effect on the outcome of the simulation. Progressive damage modeling is used to model how a composite structure will fail, and how that failure will affect the response of the structure. Many different progressive damage models exist, but the formulation known as Hashin damage is used to model failure in tension and out-of-plane bending in this study. This model has ten different material properties that are used to define the damage response of the material. Each of these material properties must be calculated experimentally in a time consuming and expensive process. A method of determining which properties will have the greatest effect on the model, and therefore, which to spend the most money on accurate tests, is a factorial analysis sensitivity study. Studies of this nature have been used in many different situations regarding material properties testing and optimization. The work presented in this study uses several factorial analysis designs to perform a sensitivity study on the ten Hashin damage parameters in a variety of situations. Five different ply layups are used in modeling specimens that are loaded in tension and out-of-plane bending. The results of this study show that the significant factors depend on the ply layup and loading scenario, but there are generally less than three factors that play a significant role in modeling the failure of the panels. This means that in most cases, rather than spending substantial money on finding ten different material properties, the time and money can be focused on a small subset of the properties, and an accurate model can still be achieved. While the results of the scenarios presented may not apply to all scenarios, the methods presented can be used to perform a similar study in other specific scenarios to find the significant factors for that case. / Graduation date: 2013

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