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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.
151

Impacto do ambiente do incubatório na produção de pintos de corte / Environmental impact of the hatchery production of broiler chicks

Poderoso, Fabiana Maria Gonçalves de Lima 20 August 2018 (has links)
Orientador: Irenilza de Alencar Nääs, Marta dos Santos Baracho / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agrícola / Made available in DSpace on 2018-08-20T11:48:14Z (GMT). No. of bitstreams: 1 Poderoso_FabianaMariaGoncalvesdeLima_M.pdf: 1087757 bytes, checksum: 1db07cd336e1192d99ffb8537b7a5e02 (MD5) Previous issue date: 2011 / Resumo: No Brasil, a avicultura é uma atividade relativamente nova, apesar de ter seu início na década de 30, como atividade fornecedora de subproduto, o esterco para os cafezais, se tornando uma atividade econômica produtora de proteína de alto valor biológico, somente a partir da década de 60. Hoje ocupa um lugar privilegiado na economia mundial devido ao trabalho de muitos profissionais ligados à atividade, sendo os principais pontos que ocorreram grandes melhorias: avanço tecnológico nas áreas de produção, nutrição e sanidade, permitindo uma melhora significativa nos índices zootécnicos. O incubatório é o local onde se obtêm o produto final, ou seja, do pintainho de um dia, tem a responsabilidade de disponibilizar aos produtores, pintos de qualidade para maximizar o desempenho das aves a campo. O presente trabalho teve como objetivo geral avaliar a influência da temperatura e da umidade relativa do ar no ambiente do incubatório, sobre as respostas da taxa de eclosão durante o processo de incubação e nascimento. Os dados de temperatura e umidade relativa do ar foram registrados em uma das salas das incubadoras e em uma das salas de nascedouro do Incubatório São José no município de Amparo - SP e analisados com relação ao índice de eclosão dos ovos incubados que foi analisado no dia do nascimento dos pintos. Foram rastreadas 48 bandejas, tendo capacidade de 96 ovos cada bandeja, até o nascimento desses pintos, sendo estas divididas seis quadrantes na incubadora sendo oito bandejas em cada quadrante classificadas como lotes e após foram monitoradas na sala de nascedouro que foi dividida em quatro quadrantes. Os dados foram submetidos à análise estatística descritiva por lote e análise de comparação de médias, através do teste F na ANOVA e do teste não-paramétrico de Kruskal-Wallis. Os resultados obtidos foram: a temperatura do ambiente influenciou o descarte total de ovos no 14º dia de incubação (de 35.9ºC à 37.0°C) e no 21º de incubação (de 37,0 °C à 37,3 °C) e, comparados com a idade das matrizes (42 semanas e 56 semanas), identificou-se que a matriz mais velha obteve maior número de descartes nas variáveis analisadas como: ovos inférteis, mortalidade de 0 a 7 dias e ovos quebrados, a serem o volume maior do total de ovos descartados. E, somente houve influência da umidade relativa do ar aos 21 dias de incubação ( de 52,2% à 62%). Conclui-se que houve influência do ambiente térmico e da idade da matriz no descarte total de ovos no processo de incubação / Abstract: Poultry science is responsible for studying the birds. In Brazil poultry production is a relatively new activity, although had its beginning in the 30's decade as an activity that supplied waste which was used in coffee production. It became an economical activity that produces protein of high biological value just after the decade of 60. Today Brazil occupies a privileged place in the world's economy due to the work of several professionals connected to this activity. The areas were the greatest technological improvements occurred are: production, nutrition and health, allowing significant enhancement in animal production indexes. The hatchery is the place where the final product is obtained, the one day old pullet, and that has the responsibility of given the producers high quality chicks in order to maximize their performance in the field. The objective of this research is to evaluate the influence of ambient temperature and relative humidity of the air in the hatchery on the response during the process in both incubator and hatcher. Air temperature and relative humidity data will be registered in a incubator and hatcher at the Incubatório São José, county of Amparo - SP and they will be analyzed with relation to the hatcher index at the first day. Forty eight trays with 96 eggs each were screened trays until the birth of these chicks. The hatchery was divided in six quarters and eight incubator trays in each quadrant were classified as lots and they were monitored after the hatcher room, which was divided into four quadrants. The data were analyzed by descriptive statistics and analysis of batch mean comparison, using the F test in ANOVA and nonparametric Kruskal-Wallis. The obtained results were: the temperature of the environment influenced the discarding total egg on day 14 of incubation and 21 of incubation and compared with age of the array, we identified that it took the variables as: infertile eggs, mortality 0-7 days and broken eggs, to be the bulk of total eggs discarded. There was only influence of relative humidity at 21 days of incubation. It is concluded that there was influence of thermal environment and age of female breeder in total egg discarding in the process of incubation / Mestrado / Construções Rurais e Ambiencia / Mestre em Engenharia Agrícola
152

Secagem de figo (Ficus Carica L.) da variedade "Gigante de Valinhos" em secador de bandejas / Dried fig (Ficus Carica L.) variety "Giant Valinhos" in tray dryer

Pacco, Honorato Ccalli 03 August 2018 (has links)
Orientador : Florencia Cecilia Menegalli / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-03T14:22:19Z (GMT). No. of bitstreams: 1 Pacco_HonoratoCcalli_M.pdf: 5330330 bytes, checksum: 95805ddfd009ac3d0f14bfe1ecde920f (MD5) Previous issue date: 2003 / Resumo: Estudou-se a secagem de figo [Fícus carica L.) da variedade "Gigante de Valinhos", obtido no Município de Valinhos no Estado de São Paulo. Os figos devidamente transportados desde o centro de abastecimento, foram selecionados, classificados, lavados, escorridos e seguidamente pré-tratados, obtendo-se as seguintes especificações: inteiro in natura, inteiro perfurado, inteiro branqueado com casca, inteiro branqueado sem casca. A partir de ensaios preliminares optou-se pela utilização de figos semi-maduros, já que apresentaram melhores características para a secagem. O produto foi submetido à secagem a 45, 60 e 75°C a uma velocidade constante do ar de 1 m/s. Utilizaram-se também figos em rodelas com espessura de 10 mm, os quais foram classificados como semi-maduros nos ensaios preliminares, com características similares aos figos in natura inteiros e igualmente secos nas condições de secagem citadas anteriormente. Os figos branqueados sem casca e em rodelas secos a 60"C foram os que apresentaram melhores características de cor e aparência. A isoterma de sorção foi realizada a 25, 40 e 60°C, encontrando-se a presença de histerese para cada temperatura. Os dados experimentais do calor isostérico de sorção foram ajustados através da equação de TSAMI. Os valores experimentais dos coeficientes de encolhimento foram ajustados pela equação de LOZANO. No estudo da cinética da secagem, não houve o período de secagem a taxa constante bem definida, ocorrendo somente o período decrescente, tanto para figos inteiros como para figos em rodelas. A equação de Page foi a que melhor ajustou a curva da secagem de figo inteiro. Os dados obtidos foram correlacionados através de diversas equações, a fim de se encontrar a mais adequada ao projeto e simulação de secadores. Tanto as curvas da cinética de secagem como os dados de sorção foram ajustados com o auxílio do Software Gráfico STATISTICA versão 5,0. A cor do produto foi medida pelo sistema CIELab* em espectofotômetro Color QUEST II / Abstract: The study of the drying of the fig was accomplished (Ficus carica L.) with fruits obtained in the district of Valinhos of the State of Sao Paulo. The figs were properly transported from the center of provisioning, then they were selected, classified, washed, drained and pretreated, obtaing the following specifications: whole in nature, whole perforated, whole blanched with skin, whole blanched without skin. From the results of preliminary tests, it was chosen to use semiripe figs that presented better characteristics for drying. The product was submitted to drying at 45, 60 and 75°C and a constant air speed of 1 m/s. Slices of figs were used with 10 millimeters thickness, which had been classified as semiripe in the preliminary tests, with similar characteristics to the whole figs and in natura fruit semiripe and they were dried in the conditions cited above. The blanched figs withount skin cut in slices and dried at 60°C presented the best color and appearance characteristics. The sorption isotherms took place at temperatures of 25, 40 and 60aC, showing histeresis for each temperature. The experimental data of the isosteric sorption heat were adjusted through the equation of TSAMl. The experimental values of the shrinkage coefficients were adjusted by the equation of LOZANO. In the study of drying kinetics, a constant rate of the drying period at a defined constant rate did not appear, occurring, only the decreasing period, for whole figs and for figs in slices. The equation of Page presented the best fit for the whole fig drying curves. The obtained data were correlated with several equations, with the objective of determining an appropriate equation to the design and simulation of dryers. The curves of drying kinetics and the sorption data were adjusted with the Graphic Software STATIST1CA version 5.0. The color of the product was measured by the system ClELab * in a spectrophotometer Color QUEST II / Mestrado / Mestre em Engenharia de Alimentos
153

A feasibility study of incorporating Surface Tension Elements to improve the efficiency of residential clothes dryers

Cochran, Michael Patrick January 1900 (has links)
Master of Science / Department of Mechanical and Nuclear Engineering / Bruce R. Babin / A Surface Tension Element (STE), device was successfully constructed and tested as the primary moisture removal device in a condensing dryer. The STE was tested via the SAE ARP901 bubble-point test method and resulted in an average micron rating of 46.8 microns. The operation of the STE was compared to that of the typical air-to-air heat exchanger/condenser used in condensing dryers. The total power consumption and IEC efficiency of each case were averaged and compared. The results indicated that the STE used an average of 0.616 kilowatt-hours per kilogram dry laundry while the air-to-air heat exchanger/condenser used an average of 0.643 kWh/kg. This resulted in an improvement of the European efficiency label from class C to Class B. An analytical model was also constructed that well predicted the operation of the STE under steady state conditions.
154

Creep properties of cementitious materials : effect of water and microstructure : An approach by microindentation / Rôle de la microstructure et effet de l'eau sur les propriétés de fluage des liants : une approche par micro-indentation

Zhang, Qing 13 February 2014 (has links)
Les matériaux cimentaires tels que le béton, le ciment et le plâtre sont largement utilisés dans la construction, les matières premières dont ils sont faits étant abondantes sur Terre. Cette tendance ne devrait pas changer dans les prochaines décennies. Mais ces matériaux subissent l'impact du fluage. Le fluage des matériaux cimentaires est une problématique complexe. D'une part, dans les matériaux cimentaires, le fluage est souvent couplé avec d'autres phénomènes tels que le séchage, l'hydratation et la fissuration, et peut être influencé par différents paramètres comme la température, le niveau de contrainte, la teneur en eau et la formulation. D'autre part, la mesure du fluage par un test macroscopique traditionnelle du fluage requiert du temps (il est recommandé de réaliser l'essai de fluage du béton sur plusieurs mois afin de donner une caractérisation fiable du fluage à long terme) et s'avère fastidieuse, puisque les paramètres expérimentaux doivent être bien contrôlés sur de longues périodes de temps. Cette thèse étudie la micro indentation à l'échelle de la pâte de ciment ou du plâtre pour évaluer les propriétés de fluage propre à long terme des matériaux cimentaires, en comparant les fonctions de fluage obtenues par des tests de micro indentation de quelques minutes avec celles obtenues par des expériences macroscopiques de fluage réalisées pendant de longues années. Pour la pâte de ciment, la comparaison a été faite à l'échelle du béton à l'aide d'une certaine homogénéisation. L'étude a validé le fait que un test de micro indentation de quelques minutes peut fournir une mesure des propriétés à long terme de matériaux cimentaires. Une fois validée la technique d'indentation, nous avons étudié l'effet de la microstructure (c'est-à-dire la distribution des phases) et celui de l'eau sur le fluage propre à long terme des matériaux cimentaires. L'effet de la microstructure a été étudiée sur des matériaux tels que des pâtes de C3S et de C2S ainsi que sur des compacts de C-S-H synthétique, de portlandite (CH) et leurs mélanges préparés par compression de poudres. Une attention particulière a été consacrée à créer des compacts avec de grandes fractions volumiques de phase cristalline. Pour tous les échantillons examinés, nous avons identifié le bon modèle micromécanique qui permette de prédire les résultats. Le choix du modèle micromécanique concorde avec les observations microstructurales. L'effet de l'humidité relative a été étudié par le conditionnement et l'indentation de certains de ces matériaux (par exemple la pâte de C3S, de compact de C-S-H et de compact de CH) dans différentes humidités relatives allant de 11% à 94%. L'humidité relative a eu un effet significatif sur le fluage : pour tous les matériaux testés, une plus grande humidité a conduit à un fluage plus important. Le compact de portlandite fut le plus sensible à l'humidité relative, sans doute parce que le fluage se produit au niveau des interfaces entre les cristaux de portlandite. Pour la pâte de C3S, une relation simple a été identifiée entre les propriétés de fluage à long terme et la teneur en eau. Enfin, nous avons proposé des modèles micromécaniques qui permettent la prédiction des propriétés de fluage à long terme de matériaux cimentaires avec une large gamme de fraction volumique de phase cristalline et sur une gamme d'humidités relatives étendue / Cementitious materials such as concrete, cement and gypsum are widely used in construction, as the raw materials of which they are made are abundant on Earth. Such trend is unlikely to change in the coming decades. But these materials suffer from creep. The creep of cementitious materials is a complex issue. On one hand, in cementitious materials creep is often coupled with other phenomena such as drying, hydration and cracking, and can be influenced by various parameters such as temperature, level of stress, water content and mix design. On the other hand, measuring creep by traditional macroscopic creep testing is time-consuming (creep test on concrete is recommended to be carried out over several months in order to provide a reliable characterization of long-term creep) and tedious, since experimental parameters need to be well controlled over extensive periods of time. This thesis studied microindentation at the scale of cement paste or gypsum plaster for the assessment of long-term basic creep properties of cementitious materials, by comparing creep functions obtained by minutes-long microindentation testing with those obtained with macroscopic creep experiments which lasted up to years. For cement paste, the comparison was made at the scale of concrete with the aid of upscaling tools. The study validated that minutes-long microindentation testing can provide a measurement of the long-term creep properties of cementitious materials. With the validated indentation technique, we studied the effect of microstructure (i.e., the distribution and the spatial organization of phases) and of water on long-term basic creep of cementitious materials. The effect of microstructure was studied on materials such as C3S pastes and C2S pastes as well as on compacts of synthetic C-S-H, portlandite (CH) and their mixtures prepared by compaction of powders. For all samples considered, we identified the right micromechanical model that allows predicting the results. The choice of micromechanical model was consistent with microstructural observations. The effect of relative humidity was studied by conditioning and testing some of those materials (i.e., C3S paste, compact of C-S-H, and compact of CH) in various relative humidities ranging from 11% to 94%. Relative humidity had a significant effect on creep: for all materials tested, a greater humidity led to a greater creep. The compact of portlandite was the most sensitive to relative humidity, probably because creep occurs at interfaces between portlandite crystals. For C3S paste, a linear relation was identified between long-term creep properties and water content at relative humidities ranging from 11% to 75%.Finally, we proposed micromechanical models that allow predicting long-term basic creep properties of cementitious materials with a wide range of volume fraction of crystalline phase and over a wide range of relative humidities
155

Incubation humidity as an environmental stressor on the osmoregulatory developmental program of the chicken, Gallus gallus domesticus.

Bolin, Greta M. 08 1900 (has links)
Fetal programming results from stressors during fetal development and may influence the occurrence of disease later in life. Maternal nutritional status and/or environment can affect renal development by inducing limited nephron endowment at birth, which results in diseases such as hypertension and coronary heart disease in mammals. Birds are likely to be effective models for this process because, like mammals, they have high pressure cardiovascular systems, mammalian-type nephrons and are homeothermic. This project uses the chicken embryo to explore physiological responses of disrupted hydration state thereby providing insights into renal fetal programming. Under normal conditions the chorioallantoic membrane (CAM) and developing avian kidney work in unison to ensure a proper balance of ions and water within the egg. White leghorn chicken eggs were incubated at 37.5oC±0.5oC and either <35%, 55-60% (normal) or >85% relative humidity. Amniotic fluid serves as the drinking source for the embryo late in development; its composition is important to salt and water homeostasis. High amniotic fluid osmolality increased the blood osmolality for embryos exposed to low humidity incubation thereby indirectly influencing the renal developmental program of the embryos from this group. Indeed estimated filtering capacity was doubled in the low humidity group (6.77 ± 0.43 mm3) compared to normal (4.80 ± 0.33 mm3) and high (3.97 ± 0.30 mm3) humidity groups. The increased filtering capacity seen for those embryos from low humidity may indicate the ability for more efficient recovery of water if similarly stressed as an adult bird. All embryo populations maintained similar oxygen consumption (0.075 ml/min - 0.37 ml/min), hematocrit (15 % - 32 %) and hemoglobin values (4 g/dl - 9 g/dl), thus displaying control over these aspects of the internal environment despite the obvious environmental insult of extreme incubation humidity. These results signify the embryo's immature kidney, along with lower gastrointestinal tract, functions much like the adult form maintaining homeostasis, although the mechanisms may differ. The overall benefits of this research included better understanding of the role the kidney during embryonic development and determining whether environmental factors, such as humidity, leave an imprint on morphological and physiological aspects of the urinary system of the embryo and water compartments of the egg.
156

Contribution to the Development of Analytical Models to Forecast Alkali-Aggregate Reaction (AAR) Kinetics and Induced Expansion

Goshayeshi, Niloufar 27 August 2019 (has links)
Alkali-aggregate reaction (AAR) is one of the most harmful distress mechanisms affecting the durability and serviceability of concrete infrastructure worldwide. Currently, there is a need to forecast future behaviour of AAR-affected concrete, and thus analytical and numerical models have been developed over the years. Larive developed a model in 1998 that is able to describe the behaviour of concrete samples in the laboratory. This model has been widely accepted and used by AAR community, even to predict the behaviour of concrete structures in the field. Larive’s model is based upon three main parameters and although they are normally set according to the concrete type under analysis, these parameters do not have a clear physicochemical meaning to describe AAR-induced expansion and development. Furthermore, it is widely known that AAR is influenced by several measurable variables such as the type and reactivity degree of the aggregates, temperature, moisture, and alkali content; those are currently not accounted for in Larive’s equation. This work aims to incorporate the previously mentioned parameters to Larive’s equation so that AAR kinetics and final expansion might be precisely described in the lab and/or field. Results indicate that the proposed modified Larive’s equation can predict AAR kinetics and final expansion in the laboratory although some modifications seem still necessary to assess field structures.
157

Heterogeneous reaction and kinetics of acetic acid on components of mineral dust aerosol

Larish, Whitney Anne 01 July 2014 (has links)
No description available.
158

Impact of stiffness and damping capacity using two different rubbers on friction coefficient and noise levels of brake materials

Punna, Harshitha 01 May 2020 (has links)
Friction contact with both external and internal environments can significantly influence its efficiency, which could cause friction instabilities, vibration, and noise. Focusing on the effects that troubles brake pad, rotor, and friction-induced NVH, the main motivation for this study is to understand its drawbacks for some extent in a braking system. By proper study on applied statistics, an experimental design is planned. The design has friction tests that are performed by scaling down real test properties used in dynamometer to scaled-down properties in a subscale tester by using scaling law of physics. The test has two different types of rubbers with different humidity conditions with respect to two different brake pads in a small-scale tester, the Universal Mechanical Tester (UMT). This friction experiment helps in determining how different rubbers impact its stiffness on the coefficient of friction and noise levels, also to evaluate which scenario has the better damping capacity. The effect on the coefficient of friction and noise levels with and without rubbers is also compared. The results are subjected to the Design of Experiments analyses test know the statistical relationship between factors affecting the process and output of that process at different controllable variables namely humidity and temperature.
159

Atmospheric Water Harvesting by an Anhydrate Salt and Its Release by a Photothermal Process Towards Sustainable Potable Water Production in Arid Regions

Alsaedi, Mossab K. 11 1900 (has links)
Only 2.5% of the water on Earth is fresh water and only less than 1% is accessible to human consumption. Landlocked and desert communities and communities that are not wealthy enough to provide clean drinking water via conventional water treatment technologies are facing severe water shortages and tend to rely on long distance transportation to supply fresh water for their daily use. As a lot of the water-scarce countries have abundant annual solar irradiation and relatively high humidity, this project proposes a technology that harvests water from ambient air using an anhydrate salt and releases it for collection using sunlight. This technology is designed to be potentially deployed in night-day cycles, as the humidity at night is at its peak, and solar irradiation during the day is also at its peak. In this work, a mesoporous silica powder filled with CuCl2 and coated with carbon nanotubes is used. The water capture performance of this material was investigated with different relative humidity environments. Furthermore, the powder agglomeration sizes of this material were also investigated for each relative humidity environment. Water release was investigated under 1 kW/m2 simulated solar light in an in-lab ~60% relative humidity environment. The results show that this mesoporous material was able to capture water at 12% relative humidity conditions, low enough to capture water from the air in the Sahara Desert. At relative humidity of 15% and 35%, the material was able to absorb 0.12 and 0.25 kg/kg of water, respectively, within 100 minutes, which indicates its fast water harvesting kinetics. A fully hydrated sample released 0.26 kg/kg of water in almost half an hour under 1 kW/m2 simulated sunlight. This project sheds more light on utilizing the atmosphere as an alternative water source.
160

Nezávislý datalogger s USB připojením / Independent datalogger with USB connection

Novobilský, Petr January 2011 (has links)
This work deals with design and construction logger capable measure temperature and relative humidity value and save them. Work also solution maximize batery life and number of record storaged in bulit-in flash memory.

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