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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.
131

Bovine milk proteins : their determination, and associations between milk protein genotypes and milk yield and composition / by Douglas M. McLean

McLean, D. M. (Douglas M.) January 1981 (has links)
Typescript (photocopy) / xv, 210 leaves, [2] leaves of plates : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / By using a regression equation relating the difference between dye binding and Kjeldahl values with the total protein concentration of the milk, the accuracy of estimates of casein in milk from individual cows was improved. / Thesis (Ph.D.)--University of Adelaide, Dept. of Animal Physiology, 1981
132

The mobilisation of soil phosphorus in surface runoff from intensively managed pastures in South-East Australia

Dougherty, Warwick John January 2006 (has links)
The application of substantial quantities of phosphorus (P) has been required to increase productivity on many Australian soils. Unfortunately, these applications have often resulted in increased concentrations of P in surface runoff that contributes to excessive algal growth in surface waters and consequently a decline in their quality. The concentrations of P in runoff from intensively managed pastures are often high (1-5 mg/L) and typically at least an order of magnitude higher than water quality targets. Although a substantial amount of research has been devoted to the problem of P accumulation and mobilisation in arable systems ( in which P is typically mobilised by the action of raindrop impact and subsequently transported in particulate form ), there has been substantially less research in intensively managed pasture systems. Consequently, there is a paucity of knowledge concerning the fundamental processes and factors responsible for P in runoff from these systems and a dearth of truly effective remedial strategies. In this thesis, the accumulation of P in soil under intensively managed pastures used for dairying and the processes responsible for its mobilisation in surface runoff were investigated. This research was undertaken at two research sites in South - east Australia, i.e. Camden in New South Wales and Flaxley in South Australia. A number of factors relating to scale and hydrology may influence the processes of P mobilisation and its concentration in runoff. A comparison was made of the forms and concentrations of P in runoff between a typical rainfall simulation methodology and large runoff plots. The effect of rainfall intensity on the forms and concentrations of P was also investigated. The concentrations of P in runoff from small - scale, high - intensity rainfall simulations were on average 33 % lower than those from large plots ( approximating hillslopes ) although the processes of mobilisation ( as evidenced by runoff P forms ) were similar. Increasing rainfall intensity resulted in decreasing P concentrations, but similar forms of P. It was hypothesised that changes in hydrological characteristics ( residence time and depth of runoff ) were responsible for the differences in the P concentrations. A model of P mobilisation ( incorporating hydrological and P - release characteristics ) was developed and shown to successfully predict runoff P concentrations under a range of rainfall intensities. These findings and the subsequent model were used in the successful modelling of landscape scale nutrient exports based on rainfall simulation data as part of a separate, but complementary project. There is anecdotal evidence to suggest that Australian soils are relatively ' leaky ' in terms of P in runoff compared to soils overseas. Consequently, comparisons of the labile soil P characteristics and soil P - runoff P relationships were made between Australian soils and soils of similar fertility from the USA, UK and New Zealand ( using both experimental data and data sourced from the literature ). It was concluded that Australian soils leak more P than soils of similar fertility in the USA, UK and New Zealand, although it was beyond the scope of the thesis to make more detailed comparisons between Australian and overseas soils. The accumulation and mobilisation of P in two soils used for intensive pasture production in Australia were investigated. In intensive pasture systems P accumulated in the shallowest zones of the soil and principally as inorganic P. The concentrations of labile P were 3 - 5 times higher in the top 0.01 m than in the top 0.1 m. Using a simple model, it was estimated that only the top several mm of soil influence runoff P concentrations. The dominant form of P in runoff was shown to be orthophosphate although in low to moderate fertility soils, dissolved organic P can constitute a substantial proportion of the P in runoff. These results confirm the need to reduce the pool of P available for mobilisation in the immediate topsoil in order to reduce runoff P concentrations. Because P is stratified, it was hypothesised that one method to reduce the pool of P available for mobilisation is to de - stratify the soil ( i.e. mix the topsoil ). The effect of this technique on runoff P concentrations was investigated in laboratory and rainfall simulation experiments. These experiments revealed that reductions in runoff P concentrations between 45 and 70 % can be achieved by de - stratification of soils under permanent pastures. It was hypothesised that the benefits of de - stratification could be maximised using a combination of information relating to catchment hydrology and the spatial distribution of soil P and that this would result in large reductions in P exports with a relatively small degree of inconvenience to land managers. Given the limited opportunities identified in previous research to reduce P exports in runoff, the strategic utilisation of de - stratification is a potentially important option in water quality management for the dairy industry and warrants further investigation. / Thesis (Ph.D.)--School of Earth and Environmental Sciences, 2006.
133

Development of an antecedent precipitation index model to detect seasonal changes in fecal coliform levels during storm events /

Bidaurreta, Jennifer L. January 1900 (has links)
Thesis (M.S.)--Humboldt State University, 2007. / Includes bibliographical references (leaves 24-25). Also available via Humboldt Digital Scholar.
134

Tratamento de águas residuárias de laticínio em reatores anaeróbios alternativos

Santos, Ariane Chiareli dos [UNESP] 27 November 2015 (has links) (PDF)
Made available in DSpace on 2018-07-27T18:26:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-11-27. Added 1 bitstream(s) on 2018-07-27T18:30:28Z : No. of bitstreams: 1 000869019.pdf: 3969961 bytes, checksum: e279291fa8339b144054553ff68e2e67 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Foi avaliado o desempenho de dois sistemas anaeróbios para o tratamento de água residuária de laticínios. O primeiro sistema foi composto por reatores anaeróbios horizontais, combinados à fertirrigação subsuperficial (SAHFS) em plantação de tomates cereja no tratamento de águas residuárias de laticínios. Diferentes meio suporte foram testados, pedra brita e tiras de pneus, para verificar qual o material proporcionaria uma melhor aderência aos micro-organismos formando assim o biofilme para o sistema de tratamento anaeróbio. Obteve-se uma eficiência de remoção de Demanda Química em Oxigênio (DQO) de 80% e 90% para o meio suporte brita e pneu (sistemas A e B), respectivamente. Foram também avaliadas diferentes concentrações de alimentação de água residuária e, verificou-se uma eficiência de remoção de DQO de 97% para os sistemas alimentados com 1 e 6 g L-1 DQO (sistema D e E, respectivamente). Para o sistema alimentado com 10 g L-1 DQO (sistema F) a eficiência de remoção de DQO foi de 92%. Em relação aos resultados obtidos pela fertirrigação subsuperficial nos sistemas D, E e F, os valores médios da taxa de crescimento das plantas foram de 80, 120 e 70 cm, e, a área de massa foliar foram de 7.000, 18.000 e 6.000 cm2, respectivamente. O segundo sistema utilizado para o tratamento de água residuária de laticínio, foi composto por um reator anaeróbio de manta de lodo invertido (IASB). Uma nova configuração do reator anaeróbio de alta taxa que visa principalmente tratar águas residuárias com grandes quantidades de lipídios como é o caso da água residuária de laticínio. O reator foi operado em ciclos de alimentação/reação, para que o consórcio microbiano do reator conseguisse degradar a matéria orgânica. Durante os ciclos foram testados diferentes Tempo de Detenção Hidráulico (TDH) de 1.00, 0.67 e 0.33 dias e uma Carga Orgânica Volumétrica (COV) de 2.4, 3.6 e 7.2 g DQO L-1. Foi possível... / The performance of two anaerobic systems for treating wastewater from dairy products industries was evaluated. The first systems composed by horizontal-flow anaerobic reactors combined with subsurface ferti-irrigation (SAHFS) culture cherry tomato were fed with wastewater from the dairy products industry. Different support materials, crushed stone and tire strips, were used in order to verify the best materials which provide a better adherence to microorganisms, thereby forming a biofilm for the anaerobic treatment system. The chemical oxygen demand (COD) removal efficiency obtained was 80 % and 90 % for the material crushed stone and tire strips (Systems A and B) respectively. Also different feed concentrations of wastewater were tested, and 97 % of COD removal efficiency was obtained for the system feed with 1 and 6 g L-1 COD (system D and E, respectively). For the system feed with 10 g L-1 COD (system F) the COD removal efficiency was 92%. The results obtained in the subsurface ferti-irrigation culture cherry tomato for the systems D, E and F, were 80, 120 and 70 cm for culture plants growth and for the leaf area mass were 7.000, 18.000 and 6.000 cm2, respectively. The second system used for the treatment of wastewater from dairy industry was composed by an inverted anaerobic sludge blanket reactor (IASB). A new configuration of high rate anaerobic reactor with the aim to treating wastewater with large amounts of lipids, as in the case of dairy industries wastewaters. The reactor operated in cycles feed/reaction, so that the microbial consortia of the reactor could degrade the organic matter. During the cycles, different Hydraulic Retention Times (HRT) were tested of 1, 0.67 and 0.33 days and also different organic load rate (OLR) of 2.4 3.6 and 7.2 g COD L-1. It was possible to verify values of COD removal of 90% in all HRT and OLR used. The production of methane during the experiment was 70 - 80 L CH4 day-1. The percentage of organic ...
135

Tratamento de águas residuárias de laticínio em reatores anaeróbios alternativos /

Santos, Ariane Chiareli dos. January 2015 (has links)
Orientador: Vanildo Luiz Del Bianchi / Coorientador: Maria Madalena Alves / Coorientador: Giovana Tommaso / Banca: Ana Júlia Viana Cavaleiro / Banca: Gisele Ferreira Bueno / Banca: Crispin Humberto Garcia Cruz / Banca: Crislene Barbosa de Almeida / Resumo: Foi avaliado o desempenho de dois sistemas anaeróbios para o tratamento de água residuária de laticínios. O primeiro sistema foi composto por reatores anaeróbios horizontais, combinados à fertirrigação subsuperficial (SAHFS) em plantação de tomates cereja no tratamento de águas residuárias de laticínios. Diferentes meio suporte foram testados, pedra brita e tiras de pneus, para verificar qual o material proporcionaria uma melhor aderência aos micro-organismos formando assim o biofilme para o sistema de tratamento anaeróbio. Obteve-se uma eficiência de remoção de Demanda Química em Oxigênio (DQO) de 80% e 90% para o meio suporte brita e pneu (sistemas A e B), respectivamente. Foram também avaliadas diferentes concentrações de alimentação de água residuária e, verificou-se uma eficiência de remoção de DQO de 97% para os sistemas alimentados com 1 e 6 g L-1 DQO (sistema D e E, respectivamente). Para o sistema alimentado com 10 g L-1 DQO (sistema F) a eficiência de remoção de DQO foi de 92%. Em relação aos resultados obtidos pela fertirrigação subsuperficial nos sistemas D, E e F, os valores médios da taxa de crescimento das plantas foram de 80, 120 e 70 cm, e, a área de massa foliar foram de 7.000, 18.000 e 6.000 cm2, respectivamente. O segundo sistema utilizado para o tratamento de água residuária de laticínio, foi composto por um reator anaeróbio de manta de lodo invertido (IASB). Uma nova configuração do reator anaeróbio de alta taxa que visa principalmente tratar águas residuárias com grandes quantidades de lipídios como é o caso da água residuária de laticínio. O reator foi operado em ciclos de alimentação/reação, para que o consórcio microbiano do reator conseguisse degradar a matéria orgânica. Durante os ciclos foram testados diferentes Tempo de Detenção Hidráulico (TDH) de 1.00, 0.67 e 0.33 dias e uma Carga Orgânica Volumétrica (COV) de 2.4, 3.6 e 7.2 g DQO L-1. Foi possível... / Abstract: The performance of two anaerobic systems for treating wastewater from dairy products industries was evaluated. The first systems composed by horizontal-flow anaerobic reactors combined with subsurface ferti-irrigation (SAHFS) culture cherry tomato were fed with wastewater from the dairy products industry. Different support materials, crushed stone and tire strips, were used in order to verify the best materials which provide a better adherence to microorganisms, thereby forming a biofilm for the anaerobic treatment system. The chemical oxygen demand (COD) removal efficiency obtained was 80 % and 90 % for the material crushed stone and tire strips (Systems A and B) respectively. Also different feed concentrations of wastewater were tested, and 97 % of COD removal efficiency was obtained for the system feed with 1 and 6 g L-1 COD (system D and E, respectively). For the system feed with 10 g L-1 COD (system F) the COD removal efficiency was 92%. The results obtained in the subsurface ferti-irrigation culture cherry tomato for the systems D, E and F, were 80, 120 and 70 cm for culture plants growth and for the leaf area mass were 7.000, 18.000 and 6.000 cm2, respectively. The second system used for the treatment of wastewater from dairy industry was composed by an inverted anaerobic sludge blanket reactor (IASB). A new configuration of high rate anaerobic reactor with the aim to treating wastewater with large amounts of lipids, as in the case of dairy industries wastewaters. The reactor operated in cycles feed/reaction, so that the microbial consortia of the reactor could degrade the organic matter. During the cycles, different Hydraulic Retention Times (HRT) were tested of 1, 0.67 and 0.33 days and also different organic load rate (OLR) of 2.4 3.6 and 7.2 g COD L-1. It was possible to verify values of COD removal of 90% in all HRT and OLR used. The production of methane during the experiment was 70 - 80 L CH4 day-1. The percentage of organic ... / Doutor
136

Milk yield and quality, nitrogen metabolism and rumen fermentation parameters in dairy cows fed different level of dietary concentrate and live yeast

Shabangu, Nomthandazo Petronella January 2015 (has links)
MSCAGR (Animal Science) / Department of Animal Science / The overall objective of this study was to investigate the effects of level of dietary concentrate and live yeast (LY) on milk yield, milk composition, rumen fermentation and nitrogen metabolism in lactating dairy cows. Four primiparous Holstein dairy cows in early lactation (average weight 500 ±9 kg and 20 days in milk (DIM)) were used in a 4 x 4 Latin Square design for a period of 44 days. The animals had seven days of adaptation to the treatments and four days for measurements. The treatments were, Low concentrate to forage (C:F) diet (40:60) with no additive, High C:F diet (60:40) with no additive, High C:F diet with LY and Low C:F diet with LY.Cows weremilked at 06h00 and 16h00 daily and milk samples were analysed for fat, protein, lactose milk urea nitrogen (MUN) and somatic cell count (SCC). Proximate analysis of feed samples was done and daily feed intake was recorded. Weight and body condition score were determined at beginning and end of every experimental period. Faecal and urinary nitrogen (N)were determined. In vitro batch fermentation was conducted to determine ruminal fermentation kinetics. Data generated from the feeding trial was analysed for a 4 x 4 Latin square design (LSD) using the PROC MIXED procedure of SAS (2009) and data for the invitro trialwassubjected to ANOVA using PROC GLM (SAS Institute, 2009) for a complete randomized design. Addition of LY affected only dry matter intake (DMI) (P<0.05), which effect was pronounce when cows were fed low (40:60) C:F diet resulting in better feed efficiency(FE). Cows fed high C:F diet consumed more feed, produced more milk with high fat and protein content (P<0.05). Both LY and C:F reduced (P<0.05) N intake as result of low DMI, but reduced (P<0.05) N excretion in manure. Addition of LY decreased ruminal ammonia and increased total VFA’s (P<0.05). The effects on ammonia suggest a better utilisation of diet proteins and probably more incorporation of products of CP degradation into microbial proteins, which support the observed reduced manure N excretion. The opposite was observed with high C:F diet, which increased ammonia and decreased total VFA’s. Propionate and butyrate were increased and decreased, respectively by high C:F diet.Addition of LY reduced SCC and MUN compared to control.The effects of LY were better pronounced on most parameters at low C:F diet. It is therefore recommended that the effects of LY be tested at low C:F on a larger scale of animals over longer periods to observe its effect of the rest of the parameters.
137

Tariffication in the dairy industry : a spatial equilibrium approach to analyze geographic price relationships between Canada and United States

Rinfret, Hugues January 1993 (has links)
No description available.
138

Cooperation in Sardinia : Production, Exchange and Cooperatives among Highland Pastoralists

Vargas-Cetina, Rosa Gabriela January 1993 (has links)
Note:
139

Building 'a natural industry of this country': an environmental history of the Ontario cheese industry from the 1860s to the 1930s / An environmental history of the Ontario cheese industry

Goodchild, Hayley 11 1900 (has links)
This dissertation examines the origins and development of the cheese industry in rural Ontario between the 1860s and 1930s from the perspective of environmental history. Scholars have generally accepted contemporary beliefs that cheese was a “natural industry of this country” and that its growth was cooperative and inevitable. This dissertation tests these claims by comparing the rhetoric and actions of the rural elite and state officials against the human and extra-human work involved in manufacturing cheese for export, a method that has yielded new interpretations about the character and development of the industry. I build on James Murton’s concept of “alternative rural modernity” to argue that rural cheese manufacturing was a project of rural reform encouraged by elite ‘dairy reformers,’ rather than a natural development. Reformers believed cheese factories could support the social, economic and environmental stability of rural society indefinitely. Through cheese, they sought to create a society that was liberal and capitalist, but also cooperative and stable. They also believed that dairying would restore fertility to the region’s soils. In practice, however, their results were mixed. Although cheese became one of the province’s most significant export-oriented industries, transformed the environment, and deepened liberal values amongst rural people, it failed to deliver the alternative rural modernity reformers had envisioned. I provide two reasons why. First, the reformers’ mechanistic vision could not contend with the complexity and unpredictability of the socio-ecological world they sought to control. Second, the industry could not withstand the pressures of the emerging global capitalist food system and, ironically, facilitated the rise of ‘Big Dairy’ after the First World War, which hastened the industry’s demise. Overall, this dissertation emphasizes the dynamism of rural Ontario, contributes to an environmental history of liberal order in Canada, and contextualizes the resurgence of craft-based rural development in the twenty-first century. / Thesis / Doctor of Philosophy (PhD) / This dissertation examines the origins and development of the factory cheese industry in rural Ontario between the 1860s and 1930s. I challenge the belief that cheese manufacturing was a “natural industry of this country” whose development was cooperative and inevitable. Instead I argue that the industry was a deliberate project of rural reform encouraged by elite ‘dairy reformers’ who believed cheese factories could sustain the social, economic, and environmental progress of rural society indefinitely. The industry failed to deliver all the reformers promised, even though it became one of the province’s most significant export-oriented industries by the early-twentieth century and transformed the environment and rural society in the process. Rural people and the environment behaved in more complicated ways than reformers anticipated, and the changing capitalist economy made the industry’s long-term success untenable. This study also contextualizes the twenty-first century resurgence of craft production in Ontario.
140

The effect of available resources on the forage-grain feeding ratios and forage production systems on selected Virginia grade A dairy farms

Reynolds, Robert K. 07 April 2010 (has links)
Dairy farmers in Virginia are confronted with the problem of continually re-organizing and adjusting their farming operations in an effort to maintain or improve their competitive position. Increasing competition in dairying within the state, as well as potential competition developing in areas outside of the state, makes it essential that dairymen operate efficiently. In particular, they must give careful consideration to various ways of reducing their production costs. Feed costs make up 50 to 60 percent of the total cost of producing milk. Consequently, the feeding program on any dairy farm greatly affects the cost of producing milk and, ultimately, the net return to the farmer. This study had four objectives: (1) to determine the available resources and their restrictions on the farms included in this study; (2) to determine an optimum forage and grain production system and forage to grain feeding ratio for three levels of milk production per cow with milk sales at the blend price not to exceed the present total base sales; (3) to determine which of the three levels of milk production is the most profitable at the present blend price of $5.73 per 100 pounds; (4) to study the effect of changes in the price of milk on the relative profitability of the three levels of production per cow and the forage-to-grain feeding ratios when the amount of profitable milk production is less than the present base. / Master of Science

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