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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.
1211

Effects of rhizosphere priming and microbial functions on soil carbon turnover

Lloyd, Davidson A. January 2015 (has links)
A major uncertainty in soil carbon studies is how inputs of fresh plant-derived carbon affect the turnover of existing soil organic matter (SOM) by so-called priming effects. Priming may occur directly as a result of nutrient mining by existing microbial communities, or indirectly via microbial population adjustments. Soil type and conditions may also influence the intensity and direction of priming effects. However the mechanisms are poorly understood. The objectives of this study were (1) to investigate how additions of labile C4 substrate affected SOM turnover in two contrasting unplanted C3 soils (clayey fertile from Temple Balsall, Warwickshire (TB) and sandy acid from Shuttleworth, Bedfordshire (SH) using13 C isotope shifts; (2) to investigate the influence of rhizodeposition from plant roots on SOM turnover in the same two soils planted with a C4 grass; (3) to assess an automated field system for measuring soil temperature, moisture and photosynthesis sensitivities of SOM turnover in the same two soils over diurnal to seasonal time scales. I used a combination of laboratory incubation, glasshouse and field experiments. In the soil incubation experiment, I made daily applications of either a maize root extract or sucrose to soil microcosms at rates simulating grassland rhizodeposition, and followed soil respiration (Rs) and its δ13 C over 19 days. I inferred the extent of priming from the δ13 C of Rs and the δ13 C of substrate and soil end-members. There were positive priming effects in both soils in response to the two substrates. In the SH soil there were no differences in priming effects between the substrates. However in the TB soil, sucrose produced greater priming effects than maize root extract, and priming effects with sucrose increased over time whereas with maize root extract declined after the first week. I explain these effects in terms of the greater fertility of the TB soil and resulting greater microbial nitrogen mineralization induced by priming. Because the maize root extract contained some nitrogen, over time microbial nitrogen requirements were satisfied without priming whereas with sucrose the nitrogen demand increased over time. In the glasshouse experiment, I planted C4 Kikuyu grass (Pennisetum clandestinum) in pots with the same two soils. The extent of rhizodeposition by the plants was altered by intermittently clipping the grass in half the pots (there were also unplanted controls) and priming effects were inferred from the δ13 C of Rs and the δ13 C of plant and soil end-members. Unclipped plants in both soils generated positive priming effects, while clipping reduced priming in TB soil and produced negligible PEs in SH soil. Microbial nutrient mining of SOM again explained the observed PEs in this experiment. Photosynthesis was a major driver of priming effects in the planted systems. In the third experiment, I found that the tested automated chamber system provided reliable measurements of Rs and net ecosystem exchange (NEE), and it was possible to draw relations for the dependency of Rs and NEE on key environmental drivers. Collectively, the results contribute to a better understanding of the mechanisms of priming effects and highlight possibilities for further research. The methods developed here will allow high temporal and spatial resolution measurements of Rs and NEE under field conditions, using stable isotope methods to separate fluxes into plant- and soil-derived components. Keywords: Soil respiration, soil moisture, soil temperature, Isotope ratio, maize root, flux chamber, climate change, organic matter, rhizodeposition.
1212

Evaluation of reclaimed asphalt pavement materials from ultra-thin bonded bituminous surface

Musty, Haritha Yadav January 1900 (has links)
Master of Science / Department of Civil Engineering / Mustaque Hossain / The ultra-thin bonded bituminous surface (UBBS), popularly known as Novachip, is a thin hot-mix asphalt layer with high-quality, gap-graded aggregates bonded to the existing surface with a polymer-modified emulsion membrane. This thin surfacing improves ride quality, reduces road-tire noise, minimizes back spray, and increases visibility under wet conditions. The Kansas Department of Transportation (KDOT) has been using UBBS since 2002. Performance of this thin surface treatment strategy has been good in Kansas and elsewhere. However, some of these projects are now being rehabilitated. The objective of this study is to evaluate whether reclaimed asphalt pavement (RAP) materials from existing UBBS layers can be used in chip seal and Superpave mixtures. UBBS millings were studied with two different polymer-modified emulsions to assess their performance as precoated aggregates in chip seal. The ASTM D7000-04 sweep test was used to assess chip retention of UBBS millings. Three different mix designs were developed for both 12.5-mm and 9.5-mm nominal maximum aggregate size (NMAS)Superpave mixtures using a PG 70-22 asphalt binder and three different percentages (0%, 10%, and 20%) of reclaimed UBBS materials. The designed Superpave mixes were then tested for performance in terms of rutting and stripping using the Hamburg wheel tracking device (HWTD)and moisture sensitivity by modified Lottman tests. Sweep test results showed that UBBS millings did not improve chip retention. Superpave mix design data indicated volumetric properties of Superpave mixes with UBBS millings met all requirements specified by KDOT. HWTD and modified Lottman test results indicated all designed mixes performed better with the addition of UBBS millings as RAP materials. Field performance of UBBS projects was also evaluated. It was found that pavements treated with UBBS showed high variability in service life with majority serving six years. Before and after (BAA) studies showed that UBBS reduces pavement roughness, transverse and fatigue cracking one year after the treatment. However, no consistent improvement in rutting condition was found.
1213

Physico-chemical properties, and water and oil uptake characteristics of novel, soy-based snacks processed using extrusion

Kodavali, Swathi Sree January 1900 (has links)
Master of Science / Department of Grain Science and Industry / Sajid Alavi / Extrusion processing and frying are the two most commonly used methods to produce savory snacks. These snacks are mostly starch based and also contain high amounts of fat. Snacking percentage has increased drastically over the past few decades causing many health problems like obesity, hypertension and cardiovascular diseases. The overall objective of this study was to develop novel soy based savory snack that are high in protein and has less fat using both extrusion processing and frying. In the first part of this study both defatted soy (25-75%), wheat flour, monoglycerides (0.375 & 0.75%) and sodium bicarbonate (0 and 0.5%) were used to produce dense extrudates, which mimic the shape of lentils using pilot scale twin screw extruder. The extrudates were soaked in water and fried in corn oil to produced savory snacks. Soy influenced the water absorption during soaking and oil uptake during frying. The water uptake and % fat decreased with increase in soy and the amount of water uptake influenced the % fat absorption in the product. No significant differences were observed in overall acceptability and to summarize the increased protein and dense structure of the products challenge the texture of the products. In the second part of this research, dynamics of water and oil uptake were studied to see the role of texture modifiers like soy protein isolate (4, 8, & 12%), calcium bicarbonate (0.2, 0.4 & 0.6%) and pregelatinized wheat starch (4, 8, & 12%) on texture, water and oil uptake. Descriptive sensory analysis was conducted to study the sensory attributes of the products. Water holding capacity is influenced by the level of % starch addition and the degree of starch degradation during processing. Oil uptakes correlates to that of WHC and is also affected by the degree of gelatinization and crust formation. Degree of starch gelatinization, oil uptake and oil and starch matrix interactions had an impact on hardness. Among SPI, CaCO3 and PGWS, PGWS lowered the product hardness followed by SPI and CaCO3. Descriptive sensory results are similar to experimental results with PGWS samples having lower initial or substantial hardness and more oxidized or heated oil aroma and flavor.
1214

Capteurs intégrés pour la fiabilisation des technologies d'encapsulation en microélectronique / Embedded sensors for microelectronics packaged module reliability

Quelennec, Aurore 13 July 2018 (has links)
L’entreprise IBM a lancé en 2014 un projet de recherche pour introduire de l’intelligence, c’est-à-dire des capteurs, dans des modules micro-électroniques. Le projet vise l’amélioration, à partir des données des capteurs, des procédés d’assemblage de puce qui serviront dans des serveurs pour du calcul haute performance ou les télécommunications.Mon projet consiste à concevoir, caractériser, puis intégrer 109 micro-capteurs, de dimensions 1 x 100 x 100 µm3, de température, humidité et contrainte sur une puce électronique de 2 x 2 cm2. L’objectif est d’obtenir en temps réel la répartition de l’humidité, la température et la contrainte dans l’assemblage, en environnement sévère.Les capteurs à base de nanotubes de carbone réalisés sont très sensibles à l’humidité et la température, avec par exemple une variation de 50% de la grandeur de sortie du capteur pour une variation de -40 à 140 °C. J’ai proposé une méthode novatrice à partir des propriétés de l’impédance du capteur permettant la séparation de la réponse à la température de celle à l’humidité. / IBM is combining forces with the Université de Sherbrooke to introduce intelligency, which are sensors, in microelectronics module. The project is to make the assembly process of a chip more robust thanks to the sensor data. These microelectronics module are used in high-performance computing servers or telecommunications. The objectives are to design, characterize and embed 109 micro-sensors, having dimensions below 1 x 100 x 100 µm3. These micro-sensors will be on chip and measure temperature, moisture and strain. Thus these micro-sensors will give the spatial distribution of temperature, moisture and strain into the microelectronics module in severe environments. The carbon nanotube-based sensor realized are very sensitive to moisture and temperature, as example the output quantity value of the sensors is reduced by 50 per cent with a temperature excursions from -40 to 140 ℃. I developed a novel method to separate the temperature response from the moisture one, using the impedance properties of the sensor.
1215

Through air drying : The influence of formation and pulp type on non-uniform drying and air flow

Tysén, Aron January 2014 (has links)
The removal of water is an integral part of tissue paper production. Through air drying (TAD) is used for water removal when producing premium tissue grade products, however, at the price of higher energy demand. A better understanding of TAD may therefore lower the energy demand. The objective was to investigate the influence of formation, pulp type and grammage on non-uniform drying and air flow through sheets. A laboratory method, based on infrared thermography, was used to determine drying time and area-specific and mass-specific drying rates. Air flow rate and pressure drop were used to determine flow resistance and modified permeability. Pulp type had a large influence on the air flow through the sheet. Modified permeability, i.e. the material property describing the air flow through the fibre network, was strongly dependent on grammage for lower grammages, while it approached a constant value for higher grammages. In contrast to that, mass-specific drying rates were similar for the different pulp types at lower grammages, but proved to be grammage-dependent for higher grammages. Formation did not influence the drying speed to any large extent. The results illustrate that industrial TAD processes operate under very special process conditions due to the low grammage sheets.
1216

Conservação de sementes de Talauma ovata St. Hil. / Talauma ovata St. Hil. seed conservation

Pupim, Túlio Lourenço 31 October 2008 (has links)
A pesquisa objetivou estudar a influência do grau de umidade da semente e da temperatura de armazenamento sobre a conservação das sementes de Talauma ovata. Para tanto, dois lotes de sementes com teores de água iniciais de 23,5% (lote 1) e 23,8% (lote 2) foram submetidos à secagem para a obtenção de sementes com os demais teores de água, 17,4%, 10,9% e 7,1% para o lote 1 e 15,8%, 13,1% e 10,0% para o lote 2. Em seguida, as sementes foram acondicionadas em sacos de polietileno e armazenadas sob temperaturas controladas de 15ºC e de 20ºC. As sementes foram armazenadas por 180 dias, lote 1, e por 60 dias, lote 2, e avaliadas mensalmente quanto ao teor de água, à emergência da plântula, ao índice de velocidade de emergência da plântula, à velocidade de emergência da plântula, ao comprimento da plântula e à massa da matéria seca da plântula; as sementes do lote 2 foram também avaliadas quanto à sanidade. O potencial fisiológico das sementes de Talauma ovata é favorecido pela secagam das sementes. A qualidade inicial das sementes de T. ovata influencia a longevidade das sementes. A secagem das sementes, para teores de água entre 10,9% e 13,1%, e o armazenamento das sementes a 15°C favorecem a conservação das sementes de T. ovata. / The research aimed to study the influence of the seed moisture content and storage temperature on Talauma ovata seed conservation. Thus, two seed lots with initial moisture content of 23.5% (lot 1) and 23.8% (lot 2) were dried and obtained tree moisture content levels in each lot, and the moisture contents were 17.4 %, 10.9% and 7.1% for lot 1 and 15.8%, 13.1% and 10.0% for lot 2. After obtaining the moisture content, seeds were conditioned in polyethylene bags and stored under controlled temperature at 15°C and 20°C. Seeds were stored for 180 days, lot 1, and 60 days, lot 2, and were monthly evaluated as for moisture content, sand seedling emergence, emergence index, seedling emergence speed, seedling length and seedling dry mass; seeds from lot 2 were also evaluated as health condition. Talauma ovata seeds has the phisiological potencial favored by drying seeds. T. ovata seed longevity has been influenced by initial quality. T. ovata seed conservation is favoured by seed with moisture content between 10,9% and 13,1% and storage temperature at 15°C.
1217

Contribuição dos horizontes profundos do solo para o fornecimento de nutrientes em plantações de eucalipto / Contribution of deep horizons of the soil to nutrients supply in eucalypts plantations

Silva, Eduardo Vinicius da 06 September 2011 (has links)
No Brasil, a alta produtividade das plantações florestais tem despertado grande interesse em relação à nutrição das árvores. Diante disso, este trabalho tratou de 2 estudos sobre a absorção de nutrientes pelas árvores de Eucalyptus grandis. O primeiro avaliou o potencial de absorção de N, K e Ca pelas árvores de E. grandis (6 anos de idade - 25 m de altura média) em função da profundidade, da textura e da umidade do solo. Através de tubos de plástico, aplicou-se conjuntamente os marcadores NO3 --15N, Rb+ (análogo ao K+) e Sr2+ (análogo ao Ca2+) nas profundidades de 10, 50, 150 e 300 cm, num Latossolo vermelho textura média e num Latossolo vermelho argiloso. Utilizou-se o delineamento experimental inteiramente casualizado com 3 repetições de pares de árvores por profundidade de injeção e por tipo de solo. Após a injeção dos marcadores nas quatro profundidades, coletou-se dessas árvores folhas recém expandidas em vários períodos do verão, sendo o experimento repetido no período do inverno. O conteúdo de água foi monitorado continuamente em diferentes profundidades dos dois solos. A partir das quatro profundidades de injeção dos marcadores, a determinação das concentrações foliares de Rb, de Sr e da percentagem de átomo de 15N permitiu estimar a potencial absorção relativa (PAR) e a potencial absorção relativa específica (PARE), definida na divisão da PAR pela densidade de raízes finas em cm cm-3 (DRF), na camada de solo correspondente. O segundo, através de microeletrôdos seletivos de íons, mediu os fluxos de NH4 +, NO3 -, K+ e H+ (nmol m-2 s-1) em soluções de NH4NO3 (50 µM) e KNO3 (50 µM). Os microeletrôdos foram posicionados ao longo da raiz desde a ponta (0 cm) até 0,5; 1,0; 1,5; 2,0; 3,0; 5,0; e 8,0 cm de distância da ponta da raiz. Os fluxos foram medidos na raiz fina de 4 mudas de E. grandis que permaneceram numa solução pré-tratamento menos concentrada (50 µM) e na raiz fina de 4 mudas que permaneceram numa solução pré-tratamento mais concentrada (500 µM). No primeiro estudo, os resultados sugeriram que as raízes finas de E. grandis apresentaram um contraste entre as taxas potenciais de absorção e a profundidade, dependendo do nutriente. No segundo estudo, a tendência de maior absorção K+ e NH4 + em relação ao NO3 - pôde ter ocorrido devido às células das raízes de E. grandis serem mais permeáveis ao K+ e a forma preferencial de absorção de nitrogênio desta espécie ser o NH4 +. Os padrões distintos de absorção de NH4 +, K+ e NO3 -, desde a ponta da raiz das mudas de E. grandis até 8 cm de distância, puderam resultar das diferenças morfológicas, como: maior absorção de íons entre a zona de diferenciação e elongação celular das raízes e a zona de maturação celular (zona branca até 2 cm de distância da ponta); e diminuição da absorção na zona em que as células do córtex começaram a morrer ou já estavam mortas (zona escura entre 2 e 8 cm de distância da ponta da raiz). / The high productivity of forest plantations in Brazil has attracted great interest in relation to the nutritional aspect of trees. Therefore, this work deals with two studies on nutrient uptake by trees of Eucalyptus grandis. The first assessed the potential uptake of N, K and Ca by E. grandis trees (6 years of age 25 m mean height), in Brazil, as a function of soil depth, texture and water content. We injected NO3 --15N, Rb+ (analogue of K+) and Sr2+ (analogue of Ca2+) tracers simultaneously in a solution through plastic tubes at 10, 50, 150 and 300 cm in depth in a sandy and a clayey Ferralsol soil. A complete randomized design was set up with 3 replicates of paired trees per injection depth and soil type. Recently expanded leaves were sampled at various times after tracer injection in the summer, and the experiment was repeated in the winter. Soil water contents were continuously monitored at the different depths in the two soils. Determination of foliar Rb and Sr concentrations and 15N atom% made it possible to estimate the relative uptake potential (RUP) of tracer injections from the four soil depths and the specific relative uptake potential (SRUP), defined as RUP, per unit of fine root length density (RLD) in the corresponding soil layer. The second, in solutions of NH4NO3 (50 µM) and KNO3 (50 µM) were measured the flows of NH4 +, NO3 -, K+ and H+ (nmol m-2 s-1) through microelectrodes selective ions. Along the root, the microelectrodes were positioned at the root tip (0 cm) to 0.5, 1.0, 1.5, 2.0, 3.0, 5.0, and 8.0 cm away of the root tip. The flows were measured in fine roots of 4 E. grandis seedlings that remained in a pretreatment solution less concentrated (50 µM) and fine root of 4 seedlings that remained in pretreatment solution more concentrated (500 µM) through ion selective microelectrode. In the first study, the results suggest that the fine roots of E. grandis trees exhibit contrasting potential uptake rates with depth depending on the nutrient. In the second, the trend towards greater uptake K+ and NH4 + in relation to NO3 - may be due to the root cells of E. grandis are more permeable to K+ and to the preferred form of nitrogen absorption of this species is NH4 +. The different absorptions patterns of NH4 +, K+ and NO3 - along the roots of E. grandis seedlings from the root tip up to 8 cm away can be the result of morphological differences, such as higher absorption of ions between the zone of cell differentiation and elongation of the roots and cell maturation zone (white zone up to 2 cm away from tip), and decreased absorption in the area where the cortical cells start dying or already are dead (dark zone between 2 and 8 cm away from the root tip).
1218

Efeito do tratamento com calor e baixa umidade sobre características físicas e funcionais dos amidos de mandioquinha-salsa (Arracacia xanthorrhiza), de batata - doce (Ipomoea batatas) e de gengibre (Zingiber officinale). / Effect of heat-moisture treatment in physics and funcionals caracteristics of peruvian carrot starch (Arracacia xanthorrhiza), of sweet potato starch (Ipomoea batatas) and of ginger starch (Zingiber officinale).

Vieira, Fabiana do Carmo 04 October 2004 (has links)
O objetivo do presente trabalho foi o de obter maiores informações acerca das modificações causadas pelo tratamento com calor e baixa umidade (TCBU) sobre a estrutura granular e propriedades funcionais dos amidos extraídos de mandioquinha-salsa, gengibre e batata-doce, fontes alternativas desse carboidrato. Os amidos foram extraídos desses vegetais e caracterizados quanto à composição macromolecular, substâncias acompanhantes, tamanho e forma dos grânulos. Para avaliar o efeito do tratamento térmico e baixa umidade (100°C, 27% de umidade, 16 horas), os amidos foram submetidos a processo de digestão enzimática pela alfa-amilase de Bacillus sp e amiloglucosidase de Rhizopus mold. As amostras obtidas foram avaliadas quanto ao modo de ataque das enzimas aos grânulos em microscópio eletrônico de varredura (MEV), padrão de cristalinidade por difração de raios-x e propriedades da pasta em Rapid Visco Analyser (RVA). O amido de mandioquinha-salsa apresentou 17% de amilose e 0,032% de fósforo, tamanho médio de grânulo de 12,5 x 17,3µm, padrão B de cristalinidade e 38% de hidrólise enzimática. O amido de batata-doce apresentou 22% de amilose, 0,027% de fósforo, tamanho médio de grânulo de 20,4 x 26,2µm, padrão A de cristalinidade e 72% de hidrólise. O amido de gengibre apresentou 25% de amilose, 0,022% de fósforo, tamanho médio de grânulos de 17,6 x 23,2µm, padrão A de cristalinidade e 15% de hidrólise. O tratamento com calor e baixa umidade nas condições do estudo provocou aumento na suscetibilidade à ação enzimática em todos os amidos, mas principalmente no de mandioquinha-salsa. Com este tratamento ocorreram também alterações na intensidade dos picos nos difratogramas de raios-x, entretanto, os padrões de cristalinidade dos amidos não foram alterados. Os perfis e valores dos viscoamilogramas dos amidos estudados foram substancialmente alterados com o tratamento térmico em baixa umidade, havendo elevação da temperatura de pasta e do tempo para ocorrência do pico, redução nos valores de viscosidade e extinção da quebra, ou seja, estabilização da viscosidade dos amidos quando sob temperaturas elevadas e agitação mecânica. O tratamento térmico sob baixa umidade, nas condições do estudo, promoveu alterações que apontam para um rompimento seguido de rearranjo das associações internas na estrutura granular do amido fazendo com que ocorra redução da cristalinidade e aumento significativo de sua área acessível à ação enzimática. / The goal of this work is to obtain more information about the modifications caused by heat-moisture treatment (TCBU) on the granular structure and functional properties extracted of starch Peruvian carrot, sweet potato and ginger, sources alternative sources of this carbohydrato. The starches were extracted of these vegetables and how characterized macromolecular composition, non-starch components, size and form of granules. To evaluate effect of heat-moisture treatment (HMT- 100°C, 27% of humidity, 16 hours), starches had been submittedby to enzymatic digestion with alpha-amilase of Bacillus sp and amiloglucosidase of Rhizopus mold. The samples had been evaluated about the way of enzymes attack to granules in scanning electron microscope (SEM), pattern of cristallinity for rays-x diffraction and properties of the paste in Rapid Visco Analyser (RVA). The peruvian carrot starch presented amylose content of 17% and phosphorus content of 0,032%, granule average size of 12,5 x 17,3µm, standard B of cristallinity and 38% of enzymatic hydrolysis. The sweet potato starch presented of amylose content of 22%, phosphorus content of 0,027%, granule average size of 20,4 x 26,2µm, standard A of cristallinity and 72% of hydrolysis. The ginger starch presented amylose content of 25%, phosphorus content of 0,022%, granule average sizes of 17,6 x 23,2µm, standard A of cristallinity and 15% of hydrolysis. Heat-moisture treatment (HMT), in this work , caused increase in susceptibility to enzymatic action in all studied starches, but mainly in peruvian carrot starch. With this treatment had also occurred alterations in rays-x diffraction peaks intensity, however, starches patterns of cristallinity had not been modified. The heat-moisture treatment, in this conditions, changed in the profiles and values of viscosity and increase of susceptibility to enzymatic hydrolysis, what probably, it was caused by the breached crystal rearrangement, starch chain association and disruption of double helices in the amorphous regions.
1219

Alterações fisiológicas causadas pela utilização de glicerina na alimentação de frangos de corte / Physiological changes caused by using glycerin as a feed ingrediente for broilers

Komatsu, Glaucia Samira Napty 15 July 2014 (has links)
O aumento na produção de biodiesel e, consequentemente, de glicerina como subproduto, motivou a utilização desta na alimentação animal. Portanto, o presente trabalho objetivou avaliar as alterações fisiológicas do uso de glicerina na alimentação de frangos de corte, analisando o consumo e excreção de água, sua implicação na qualidade da cama e possível retenção de água pelas aves. Foram realizados três experimentos, dois com frangos de corte machos da linhagem Ross 308 e um com cama de aviário. No Experimento 1 (E1) foram utilizados 240 pintinhos distribuídos em 24 gaiolas em baterias, em um delineamento inteiramente aleatorizado (DIA) com 3 tratamentos e 8 repetições de 10 aves criadas até os 40 dias de idade. Os tratamentos foram compostos por dietas experimentais sendo: T1 - controle - à base de milho (M) e farelo de soja (FS); T2 - dieta com inclusão de 10% de glicerina loira (GL); T3 - dieta com inclusão de 8,75% de glicerina purificada (GP) para conter a mesma quantidade em glicerol que a GL. Foram avaliados o consumo de água, de ração e matéria seca (MS) das excretas como medidas repetidas no tempo. Aos 40 dias de idade foi determinada a MS do conteúdo ileal. Não houve efeito de tratamentos no consumo de ração. O consumo de água foi maior quando utilizada glicerina nas rações (T2 e T3). A relação consumo de água:ração apresentou interação tratamento × idade, sendo T2 e T3 maiores do que o controle até os 28 dias de idade e, após essa idade, o T3 passou a ser maior do que o T2. A matéria seca das excretas do T2 e T3 foi, de maneira geral, próxima ao T1 aos 16 e 20 dias e após os 24 dias de idade foi inferior. No Experimento 2 foi avaliada a capacidade de retenção de água (CRA) da cama composta por maravalha de madeira e as excretas das aves dos tratamentos do E1, acondicionadas em recipientes, em um DIA, composto por 3 tratamentos e 6 repetições. Por sete dias foi adicionada água à mistura. Foram avaliadas as umidades inicial e final para determinação da CRA, porém os resultados não apresentaram diferenças. No Experimento 3 foi elaborado um DIA similar ao E1, entretanto com os seguintes tratamentos: T1 - controle - dieta a base de M e FS; T2 - inclusão de 5% de GL; T3 - inclusão de 10% de GL. Foram realizados 2 abates (aos 7 e 42 dias de idade) e coletados: sangue, fígado, intestino músculo do peito e pintinho inteiro (apenas aos 7 dias), para avaliação da MS e proteína bruta (apenas músculo e fígado). As variáveis não apresentaram diferenças significativas, exceto pela MS do fígado, que foi menor para o T3. Os resultados indicam que aves alimentadas com níveis elevados de glicerina apresentam consumo e excreção de água maiores, podendo levar a uma piora na qualidade da cama. A matéria seca corporal, de maneira geral não foi afetada, exceção para a redução observada no fígado. / The increase in biodiesel production and, consequently, of glycerin as a byproduct, has led to its use in animal nutrition. Therefore, this study aimed to evaluate the physiological changes of feeding broilers with glycerin by analyzing water consumption and excretion, its effects on litter quality and possible water retention by poultry. Three experiments were conducted. Two comprised Ross 308 male broilers and one of poultry litter. In experiment 1 (E1), 240 chicks were distributed in 24 cages in batteries, in a completely randomized design (CRD) with three treatments and eight repetitions of 10 birds reared until 40 days of age. Experimental diets were used in the treatments: T1 - control - corn (C) and soybean meal based diet (SM); T2 - diet with 10% glycerin (GL); T3 - diet with 8.75% purified glycerin (GP) to contain the same amount in glycerol of GL. The consumption of water, feed and the dry matter (DM) of the excreta were evaluated as repeated measures in time. At 40 days of age, the DM of the ileal content was determined. There was no effect of treatments on feed consumption. Water consumption was higher when glycerin was used in the diet (T2, T3). The ratio for water:feed consumption showed interaction treatment × age, and in T2 and T3, it was greater than in the control until 28 days of age. Afterwards, T3 was greater than T2. The DM of the excreta of T2 and T3 was generally similar to that in T1 at 16 and 20 days of age, and after 24 days of age, it was lower. In experiment 2, it was evaluated the water retention capacity (WRC) of litter composed of wood shavings and excreta of the birds of treatments of E1, kept in bowls, in a CRD, composed of three treatments and six repetitions. For seven days, water was added to the mixture. It was evaluated the initial and final moisture to determine WRC. There was no difference among treatments. In E3, it was prepared a CRD similar to that in E1, with the following treatments: T1 - control - C and SMbased diet; T2 - 5% of GL; T3 - 10% of GL. Two slaughters were carried out (at 7 and 42 days of age) and it was collected: blood, liver, intestines, breast muscle and whole chick (only at 7 days) to evaluate DM and crude protein (only muscle and liver). The variables showed no significant differences, except for DM of the liver, which was lower for T3. The results show that birds fed high glycerin contents diets have increased water consumption and excretion; the increased water excretion is due to urinary loss and not to fecal loss. Body and tissue dry matter was not changed with the exception for a reduction found in the liver.
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DESENVOLVIMENTO DE UM SENSOR DE UMIDADE DO SOLO PARA DETERMINAÇÃO DA FRENTE DE MOLHAMENTO

Cruz, João Alexandre Batista da 05 September 2013 (has links)
Made available in DSpace on 2017-07-21T14:19:38Z (GMT). No. of bitstreams: 1 Joao Alexandre Cruz.pdf: 7505097 bytes, checksum: 227ae1f1c6b1c1dd753fb648adc79f93 (MD5) Previous issue date: 2013-09-05 / The knowledge and control of soil properties in gricultural cultivation, obtained from sensors at automated system, extend the possibilities of increasing the results of a culture. This work aims to develop an electrical measure sensor at low cost to determinethe soil moisture, test and evaluate the correlation between the readings and gravimetric soil moisture, considered standard to calibratethe other methods. To achieve the proposed objective, in the first place we sought to study the main aspects of the interaction process water-soil-plant and the existing methods of determination. Subsequently, we performed the fabrication of prototype sensors in different shapes and geometry. We have also developed a measurement and record systemthat enables us to collect the data and to store them in a memory card. Having the operation of the sensors as a beginning, the concept of capacitance is obtained by the effect of the electric field, the charge of two plates insulated by a dielectric material, which, therefore, in this study is the soil moisture. Thus, when there is a variation in the dielectric constant, depending on the amount of water present in it, the capacitance of the system will also vary. Finally, tests were performed to evaluate the sensors and circuitry construction. The results were satisfactory, with a correlation coefficient of 99.14% for a non conventional coplanar plates sensor. / O conhecimento e controle das propriedades do solono cultivo agrícola, obtidos a partir de sensores em sistema automatizado, ampliam as possibilidades de incremento dos resultados de uma cultura. Este trabalho tem por objetivo desenvolver um sensor de medidas elétricas e de baixo custo, para determinação da umidade do solo; testar e avaliar a correlação entre as leituras e a umidade gravimétrica do solo, considerada padrão para a calibração de outros métodos. Para alcançar o objetivo proposto, buscou-se, em primeiro lugar, o estudo dos principais aspectos relacionados ao processo de interação água-solo-planta e os métodos de determinação existentes. Posteriormente, efetuou-se a confecção de protótipos de sensores em diferentes formatos e geometria. Foi também desenvolvido um sistema de medida e registro que permite a coleta dos dados e armazenamento num cartão de memória. Tendo como princípio o funcionamento dos sensores, o conceito de capacitância, que é obtido pelo efeito do campo elétrico, da carga de duas placas isoladas por um material dielétrico, que neste estudo é o solo com umidade. Assim, quando há variação na constante dielétrica, em função da quantidade de água presente nele, a capacitância do sistema também irá variar.Por fim, realizaram-se os ensaios para avaliar os sensores e circuitos construídos. Os resultados obtidos foram satisfatórios, apresentando coeficiente de determinação de 99,14% para um sensor de placas coplanares não-convencional. létrico, capacitância, umidade do solo, sensor, arduino.

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