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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.
191

Variations in heritability and repeatability of milk, fat and percentage of fat yield in stratified Holstein-Friesian herds

Duckwall, James Ward, January 1963 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1963. / Typescript. Vita. With this is bound: Production performance of artificially and nonartificially sired herd-mates in Wisconsin / E.L. Corley, J.W. Duckwall, and E.E. Heizer. Reprinted from Journal of dairy science, vol. XLVI, no. 1 (Jan. 1963), p. 50-56. Includes bibliographical references (leaves 53-54).
192

Milk production response to supplementation of encapsulated methionine per os or casein per abomasum

Broderick, Glen Allen, January 1970 (has links)
Thesis (M.S.)--University of Wisconsin--Madison, 1970. / Typescript eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 62-74)
193

Effect of biotin supplementation on the metabolism of lactating dairy cows

Ferreira, Gonzalo, January 2006 (has links)
Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 101-118).
194

Health and welfare of high producing dairy cows : effects of milk production level on adaptive capacity of cows assessed by hypothalamo-pituitary-adrenocortical function and severity of experimental Escherichia coli mastits = Gezondheid en welzijn van hoog-productieve melkkoeien /

Kornalijnslijper, Esther, January 2003 (has links)
Thesis (doctoral)--Universiteit Utrecht, 2003. / Includes bibliographical references (158-171).
195

Novel device architectures for perovskite solar cells

Hoerantner, Maximilian January 2017 (has links)
The aim of the work presented in this thesis is to study the opto-electronic properties of semi-conducting perovskite materials when being used in unconventional solar cell device configurations. Being a young technology, perovskites as solar cell materials have seen an unparalleled rise in the research community which has driven the fastest performance inflation to power conversion efficiencies competing with the ones of long established single crystalline technologies. The ability to process perovskites inexpensively makes them the new hope in the fight against climate change. Herein device architectures were developed with a special focus on potential commercial applications. Initially the work in this thesis has been motivated by the interest in crystal growth and morphology of perovskite thin-films, which has led to the study of confined crystal growth within microstructures. Controlling the crystal domain geometry enabled the fabrication of enhanced semi-transparent devices. More efforts were directed into the improvement of specifically neutral colour semi-transparent devices, which could be improved via a simple treatment of selectively attaching shunt-blocking layers. Furthermore, a back-contacted perovskite device design was introduced, which allows not only for the fabrication of a new type of perovskite solar cell, but also represent a great material testing platform to study perovskite and electrode characteristics. This led to the discovery of charge transport distances, that exceed those of other thin-film devices. Finally, perovskite-on-silicon tandem solar cell designs were analysed through a rigorous optical model to estimate the expected real world energy yield from such systems. Important implications include the fact that two terminal tandem solar cells come close to four-terminal configurations and can overall compete, in relative terms, well with established single junction silicon cells.
196

Comportamento de variedades de soja em condições de solo compactado e níveis de irrigação /

Oliveira, Paula Regina. January 2011 (has links)
Resumo: O objetivo do vigente trabalho foi avaliar a qualidade física de um LATOSSOLO VERMELHO Eutroférrico, textura argilosa, cultivado com as variedades de soja (CAC-1 e FT-Cristalina), submetidos aos efeitos da compactação e da irrigação, utilizando os atributos físicos do solo e associá-los ao crescimento radicular e à produtividade da cultura da soja, em experimentos conduzidos em campo e em casa de vegetação (vasos). O experimento de campo constou de parcelas subdivididas, com quatro repetições cujos tratamentos principais foram constituídos por quatro níveis de compactação, proporcionados pelo tráfego controlado de tratores, três níveis de irrigação e duas camadas de solo (Capítulos 2 e 3). Foram coletadas amostras indeformadas do solo nas camadas de 0-0,10 e 0,10-0,20 m, para determinação dos atributos físicos. A produtividade máxima da soja foi obtida com a resistência do solo à penetração de 0,71 e 1,88 MPa para as variedades CAC-1 e FT-Cristalina, respectivamente. Foi obtido o valor de "S" de 0,036 e redução nos níveis mais compactados para 0,026. O experimento de casa de vegetação apresentou parcelas subdivididas com três repetições cujas variedades CAC-1 e FT-Cristalina diminuíram o comprimento de raízes à medida que aumentou a compactação e consequentemente reduziu a área explorada pelas raízes (Capítulo 4) / Abstract: The aim of the current study was to evaluate the physical quality of an Eutrustox, clayey texture, cultivated with soybean varieties (CAC-1 and FT-Cristalina), submitted to the effects of soil compaction and irrigation, using the physical attributes of soil and associates them to root growth and yield of soybean culture, in experiments conducted in field and greenhouse (vases). The field experiment consisted of split plots, with four replications, where the main treatments was consisted of four levels of compaction, induced by controlled tractors traffic, three levels of irrigation and two layers of soil (Chapters 2 and 3). Undisturbed samples of soil were collected in the layers of 0-0,10 and 0,10-0,20 m, to determine the physical attributes. The maximum yield of soybeans was obtained with the soil resistance to penetration of 0,71 and 1,88 MPa for the varieties CAC-1 and FT-Cristalina, respectively. It was obtained the "S " value of 0,036 and a reduction in the levels more compressed to 0,026. The greenhouse experiment showed a split plot design with three replications whose varieties CAC-1 and FT-Cristalina decreased the root length as increased the compaction and consequently reduced the area explored by the roots (Chapter 4) / Orientador: José Frederico Centurion / Coorientador: Maria Aparecida Pessôa da Cruz Centurion / Banca: José Renato Zanini / Banca: Alberto Carvalho Filho / Mestre
197

Influencia do uso de retentados de baixo fator de concentração no rendimento e na qualidade da mussarela de reduzido teor de gordura feita por acidificação direta / Use influence of low concentration factor ultrafiltration retentates on the yield and the quality of mozzarella of reduced text of fat made for direct acidification

Ferreira, Daniela Nunes 08 December 2004 (has links)
Orientador: Walkiria Hanada Viotto / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-03T22:21:34Z (GMT). No. of bitstreams: 1 Ferreira_DanielaNunes_M.pdf: 1136425 bytes, checksum: db7319f8dbfb05eece9d3f83668bad71 (MD5) Previous issue date: 2004 / Resumo: O objetivo deste trabalho foi avaliar a influência do uso de retentados de ultrafiltração de baixo fator de concentração na composição, rendimento, proteólise, propriedades viscoelásticas e funcionais, microestrutura e aceitação sensorial do queijo mussarela de reduzido teor de gordura feito por acidificação direta com ácido acético. Dois fatores de concentração (FC 1,4 e 1,8) foram comparados a um controle (leite não ultrafiltrado) e os ensaios foram realizados em triplicata. Leite, retentado, permeado, soro, água de filagem e queijo foram pesados e suas composições determinadas. Foram calculados as recuperações de gordura e de proteína e o rendimento de fabricação. Os queijos foram analisados nos dias 4, 11, 18, 25 e 32 do armazenamento refrigerado a 4ºC em relação a pH, acidez titulável, teor de nitrogênio solúvel (NS) a pH 4,6 e em 12% TCA e capacidade de derretimento. Nos dias 5, 12, 19, 26 e 33, os queijos foram avaliados quanto a capacidade de retenção de água, cor antes e após derretimento, óleo livre e propriedades reológicas (teste de compressão uniaxial e relaxação). A microestrutura dos queijos foi avaliada através de Microscopia Eletrônica de Varredura (MEV) no 26º dia após a fabricação e a aceitação sensorial foi verificada no 27° dia do armazenamento refrigerado. Os queijos feitos com retentados apresentaram menores teores de proteína e de cálcio (p<0,05), tendência de maior teor de umidade, menor recuperação de gordura na água de filagem (p<0,05) e maior rendimento real (p<0,05). O uso de retentados não influenciou significativamente (p>0,05) o pH, acidez titulável, proteólise, capacidade de retenção de água e capacidade de derretimento do queijo. Os queijos feitos com retentados apresentaram menor formação de óleo livre, menor elasticidade e menor firmeza (p<0,05). Os índices de proteólise aumentaram significativamente durante o tempo de armazenamento; no entanto, este aumento foi pequeno em relação aos normalmente encontrados para queijo mussarela, o que provavelmente está associado à pequena quantidade de coalho utilizado na fabricação do queijo. Isto resultou na manutenção das propriedades funcionais e reológicas constantes (p>0,05) ao longo do tempo de armazenamento. O eletroforetograma dos queijos confirma a lenta evolução da proteólise e evidencia que esta ocorreu fundamentalmente em virtude da ação do coalho residual. Os queijos feitos a partir de retentados apresentaram cor mais clara, provavelmente devido ao efeito de homogeneização da gordura que pode ter ocorrido durante a ultrafiltração do leite. Todos os queijos apresentaram uma rede protéica bastante densa devido à redução do teor de gordura. Os queijos feitos com retentados parecem ter apresentado uma rede protéica menos compacta, provavelmente em função de seu menor teor de proteína e tendência de maior teor de umidade e isto pode ter refletido nas diferenças em relação às propriedades reológicas. A qualidade sensorial do queijo não foi prejudicada pelo uso de retentados de baixo fator de concentração. Os queijos tiveram boa aceitação, apesar do reduzido teor de gordura, sendo similar à de queijos mussarela light comerciais. O uso de retentados de baixo fator de concentração se mostrou viável na produção de queijo mussarela de reduzido teor de gordura por acidificação direta. Como o fator de concentração não influenciou significativamente a qualidade dos queijos, o FC 1,8 é mais indicado por viabilizar um maior aumento da capacidade da planta. No entanto, são necessários maiores estudos no sentido de aprimorar as propriedades funcionais, em especial a capacidade de derretimento, visto que este é um atributo de fundamental importância para o queijo mussarela / Abstract: Use of low concentration factor ultrafiltration retentates on composition, yield, proteolysis, rheological and functional properties, microstructure and sensory acceptability of reduced fat Mozzarella cheese made by direct acidification was evaluated. Two concentration factors (1.4 and 1.8) were compared with a control (semi-skimmed milk) and three trials were carried out. Milk, retentate, permeate, whey, stretching water and cheese were weighted and their composition were determined. Fat and protein recoveries and yield were also calculated. Titratable acidity, pH, pH 4.6-soluble nitrogen, 12% TCA-soluble nitrogen and melting of cheese were determined at 4, 11, 18, 25 and 32 d of refrigerated storage at 4°C, and at 5, 12, 19, 26 and 33 d, water holding capacity, color of unmelted and melted cheese, free oil formation and rheological properties (uniaxial compression and stress relaxation tests) were evaluated. Cheese microstructure was evaluated by Scanning Electron Microscopy (SEM) at 26 d after manufacturing and the sensory acceptability were determined at 27 d of refrigerated storage. Cheese made with retentates had lower protein and calcium contents (p<0.05), tendency of higher moisture, lower fat recovery in stretching water and higher actual yield than control cheese. The use of retentates had no significant influence (p>0.05) on pH, acidity, proteolysis, water holding capacity and melting behaviour of cheese. Free oil formation, elasticity and firmness of cheeses were reduced when using low concentration factor retentates. The levels of proteolysis increased significantly during storage, however this increase was slow which is probably associated to the small amount of rennet used in cheese manufacture. This fact is probably responsible for no alterations of the functional and rheological properties during storage. The electrophoretogram confirms the slow changes in proteolysis and indicates that it was due to residual rennet action. Cheeses made with retentates were whiter than the control cheese, probably due to the homogenization effect that could be occurred during ultrafiltration of milk. All cheeses showed a dense protein network because of fat reduction. It seems that cheeses made with retentates had a less compact protein matrix probably due to their lower protein content and tendency of higher moisture that could reflect in the rheological differences of cheeses. The sensory quality was not impaired by the use of retentates. All cheeses had good acceptability, despite of the fat reduction, that was similar to the comercial light Mozzarella cheeses. The use of low concentration factor retentates in production of reduced fat Mozzarella cheese by direct acidification is viable and how the concentration factor did not affect significantly cheese quality, CF 1.8 is recommended because of higher improvement of plant capacity. However more research is needed in order to improve functional properties, especially melting that is an important attribute of Mozzarella cheese / Mestrado / Mestre em Tecnologia de Alimentos
198

Nutrients, Salinity and Shading in an Algae Growth Model

Gao, Song, Gao, Song January 2017 (has links)
Microalgae have been recognized as one of the most promising feedstocks for biofuel production. In the Regional Algal Feedstock Testbed (RAFT) project, scientists and engineers have been working on various topics including improving cultivation strategy, optimizing culture system, developing production models, controlling contamination, and so on. One of the objectives in this project is to improve an algae cultivation model for productivity prediction and techno-economic assessment. The model adopted in this project is the Huesemann Algae Biomass Growth (HABG) model which is based upon strain characteristics obtained from laboratory experiments. However, because the model assumed optimal growth conditions for microalgae, it over-predicted biomass growth significantly when its results were compared to outdoor raceway experimental data. For example, in an attempt to control contamination, culture salinity was raised to a high level. The high salinity may limit growth of contaminants, but it also causes stress on salinity sensitive strains of microalgae. Researchers also lowered nutrient fertilization rates in order to minimize fertilizer input and cost of production. However, this introduced nutrient stress and lowered the growth rate of microalgae. In the raceways used in the RAFT project, shade covered a large fraction of the culture surface when solar angle was low. All of these growth limiting factors were not included in the original model. In this study, salinity stress, nitrogen limitation and shading effect were incorporated into the model. Growth rate reduction due to salinity stress and nitrogen limitation were quantified through laboratory experiments. An innovative concept of nitrogen availability was introduced, which estimates the nitrogen stress factor without measuring intracellular nitrogen. The shading factor was calculated based on solar position during the day and raceway geometry. The modification greatly improved the model accuracy. In addition to HABG model improvements, this study also focused on nutrient application. Several experiments were performed in both indoor and outdoor systems to improve field cultivation practices. The nitrogen experiments provided not only the growth kinetics that improved the growth model, but also demonstrated that high lipid accumulation rate was triggered at different nitrogen stress intensities for different strains. Stress should be applied depending the saturation demand of the final lipid product. In order to quickly evaluate the nitrogen status in the culture, a nitrogen stress index using optical density was proposed. Experiments in RAFT experiments supported the feasibility of applying the method in outdoor cultivation. This study also investigated maximum biomass yields of nitrogen and phosphorus for producing S. obliquus biomass with indoor bench scale experiments. The results were tested in the outdoor raceways and demonstrated the potential of using fertilizer more efficiently in microalgae cultivation.
199

Predictive modelling and uncertainty quantification of UK forest growth

Lonsdale, Jack Henry January 2015 (has links)
Forestry in the UK is dominated by coniferous plantations. Sitka spruce (Picea sitchensis) and Scots pine (Pinus sylvestris) are the most prevalent species and are mostly grown in single age mono-culture stands. Forest strategy for Scotland, England, and Wales all include efforts to achieve further afforestation. The aim of this afforestation is to provide a multi-functional forest with a broad range of benefits. Due to the time scale involved in forestry, accurate forecasts of stand productivity (along with clearly defined uncertainties) are essential to forest managers. These can be provided by a range of approaches to modelling forest growth. In this project model comparison, Bayesian calibration, and data assimilation methods were all used to attempt to improve forecasts and understanding of uncertainty therein of the two most important conifers in UK forestry. Three different forest growth models were compared in simulating growth of Scots pine. A yield table approach, the process-based 3PGN model, and a Stand Level Dynamic Growth (SLeDG) model were used. Predictions were compared graphically over the typical productivity range for Scots pine in the UK. Strengths and weaknesses of each model were considered. All three produced similar growth trajectories. The greatest difference between models was in volume and biomass in unthinned stands where the yield table predicted a much larger range compared to the other two models. Future advances in data availability and computing power should allow for greater use of process-based models, but in the interim more flexible dynamic growth models may be more useful than static yield tables for providing predictions which extend to non-standard management prescriptions and estimates of early growth and yield. A Bayesian calibration of the SLeDG model was carried out for both Sitka spruce and Scots pine in the UK for the first time. Bayesian calibrations allow both model structure and parameters to be assessed simultaneously in a probabilistic framework, providing a model with which forecasts and their uncertainty can be better understood and quantified using posterior probability distributions. Two different structures for including local productivity in the model were compared with a Bayesian model comparison. A complete calibration of the more probable model structure was then completed. Example forecasts from the calibration were compatible with existing yield tables for both species. This method could be applied to other species or other model structures in the future. Finally, data assimilation was investigated as a way of reducing forecast uncertainty. Data assimilation assumes that neither observations nor models provide a perfect description of a system, but combining them may provide the best estimate. SLeDG model predictions and LiDAR measurements for sub-compartments within Queen Elizabeth Forest Park were combined with an Ensemble Kalman Filter. Uncertainty was reduced following the second data assimilation in all of the state variables. However, errors in stand delineation and estimated stand yield class may have caused observational uncertainty to be greater thus reducing the efficacy of the method for reducing overall uncertainty.
200

Nondormant alfalfa varieties for Arizona 2016

Ottman, Michael J 10 1900 (has links)
2 pp. / Alfalfa varieties differ in fall dormancy, defined as growth during the fall. Nondormant alfalfa varieties are usually planted in mild winter areas for their ability to grow in the late fall, winter, and early spring. Select alfalfa varieties that have resistance to potential pest problems. Alfalfa varieties are available that have salt tolerance or are Roundup Ready. Ratings are provided in this publication. Many of the varieties listed in this publication have been tested for yield and final stand by the University of Arizona in small plot trials. Revised 10/2016. Most recent version 09/2015

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