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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.
1

The impact of the removal of the Multi-Fiber Arrangement on textile and cotton trade of the United States and China

Xia, Yan 12 April 2006 (has links)
Textiles and apparel trade has been governed by the Multi-Fiber Arrangement (MFA) for three decades. Trade restrictions have generated substantial welfare losses and price wedges in exporting and importing countries through trade distortions. Beginning in 1995, textiles and apparel trade underwent fundamental changes in trade flows and patterns. The World Trade Organization’s Agreement on Textiles and Clothing (ATC) aimed to remove all MFA quotas by January 2005. This study established an equilibrium displacement model to investigate the impact on textile and cotton sectors of different countries and country-groups of removing the MFA quota. The model specifies the basic linkages of textile and cotton markets in the United States, China and four other country-groups. With different assumptions about U.S. textile supply elasticity, foreign cotton exporters’ reaction and changes in the U.S. farm program payments, alternative scenarios are simulated to predict changes in domestic and import demand for textiles and apparel, import demand for U.S. cotton, domestic and import price of textiles and apparel, U.S. cotton price and adjusted world cotton price. Uniform distribution was imposed for selected parameters involved in the model to overcome the deficiency of equilibrium displacement models of assuming certainty of known related parameters. Results indicate increased import demand for U.S. cotton by China, higher U.S. cotton supply, more textile and apparel supply from China, decreased domestic demand for U.S. cotton, and lower U.S. domestic demand for textiles and apparel. However, prices of both textile and cotton markets experience both positive and negative changes under different scenarios. Holding other assumptions unchanged, when farm program payments increase, U.S. cotton price and adjusted world cotton price declined. When farm program payments are held constant, prices rise. The changes expected in U.S. cotton price are, in absolute value, greater than those of the adjusted world price.
2

Investigating the performance of continuous helical displacement piles

Jeffrey, John January 2012 (has links)
The Continuous Helical Displacement (CHD) pile is an auger displacement pile developed by Roger Bullivant Ltd in the UK. The CHD pile is installed in-situ through the use of a drilling auger, in a similar fashion to European screw piles and as such, it has performance characteristics of both displacement and non-displacement piles Based on field experience, it is known that the load capacity performance of the CHD pile significantly exceeds the current design predictions, particularly when installed in sand. Model CHD piles were created in pluviated test beds at a range of different densities and compared to model displacement and non-displacement piles. The load tests show that the CHD piles have a similar ultimate capacity to displacement piles. Instrumentation of the model piles allowed load distribution throughout the pile length to be determined. The tests allowed design parameters to be established, with it being shown that the CHD has lower bearing capacity factors and higher earth pressure coefficients than current suggestions .The disturbance to the in-situ soil conditions caused by the installation of the CHD piles was measured using a model CPT probe. The CHD pile was found to cause significant changes in soil relative density laterally around the pile shaft while displacement piles show changes predominantly below the pile base. The CHD pile is found to cause a densification of the in situ soil for all relative densities with the greatest increase occurring in loose sand. The ultimate capacity of the CHD pile is determined from load tests carried out on field CHD piles with the aid of capacity prediction methods for piles which have not been loaded to their ultimate capacity. The results from model testing have been applied to field pile tests to allow the development of design parameters including appropriate pile diameter, bearing capacity factor Nq and the earth pressure coefficient k which are suitable for CHD piles.
3

Value of animal traceability systems in managing a foot-and-mouth disease outbreak in southwest Kansas

Pendell, Dustin Lester January 1900 (has links)
Doctor of Philosophy / Department of Agricultural Economics / Ted C. Schroeder / Concerns regarding management of animal disease and related perceptions about food safety have escalated substantially in recent years. Terrorist attacks of September 2001, discovery of bovine spongiform encephalopathy in a dairy cow in December 2003 in Washington state and subsequent discoveries of BSE infected animals in Texas in 2005 and Alabama in 2006, and recent worldwide outbreaks of highly contagious animal diseases (i.e., Foot-and-Mouth Disease and Avian Influenza A (H5N1)) have made apparent the need for animal traceability in U.S. livestock production and marketing. In addition, animal identification and trace-back systems are rapidly developing throughout the world increasing international trading standards. In recent years, increasing numbers of economic analyses of animal diseases have integrated epidemiological models into economic frameworks. However, there are only a few studies that have used this integrated framework to analyze the effects of animal traceability on highly contagious animal diseases. This study’s goal is to quantify and evaluate the economic impacts of different depths of animal identification/trace-back systems in the event of a hypothetical highly contagious foot-and-mouth disease outbreak that poses a threat to U.S. livestock competitiveness. Specifically, an epidemiological disease spread model is used to evaluate the impact of a foot-and-mouth disease outbreak in southwest Kansas. The information obtained from the disease spread model is then used in conjunction with an economic model to determine the changes in welfare of producers and consumers. Results obtained from the epidemiological model indicate that as the depth of animal identification in cattle is increased, the number of animals destroyed is reduced as are the associated costs. Also, the length of the outbreak is reduced by approximately two weeks. The economic results suggest that as surveillance is increased, decreases in producer and consumer welfare are smaller. Furthermore, as surveillance is increased, decreases in producer and consumer surplus measures can be reduced by approximately 60 percent.
4

Predicting the vertical low suspended sediment concentration in vegetated flow using a random displacement model

Huai, W., Yang, L., Wang, W-J., Guo, Yakun, Wang, T., Cheng, Y. 05 September 2019 (has links)
Yes / Based on the Lagrangian approach, this study proposes a random displacement model (RDM) to predict the concentration of suspended sediment in vegetated steady open channel flow. Validation of the method was conducted by comparing the simulated results by using the RDM with available experimental measurements for uniform open-channel flows. The method is further validated with the classical Rouse formula. To simulate the important vertical dispersion caused by vegetation in the sediment-laden open channel flow, a new integrated sediment diffusion coefficient is introduced in this study, which is equal to a coefficient multiplying the turbulent diffusion coefficient. As such, the RDM approach for sandy flow with vegetation was established for predicting the suspended sediment concentration in low-sediment-concentration flow with both the emergent and submerged vegetation. The study shows that the value of for submerged vegetation flow is larger than that for emergent vegetation flow. The simulated result using the RDM is in good agreement with the available experimental data, indicating that the proposed sediment diffusion coefficient model can be accurately used to investigate the sediment concentration in vegetated steady open channel flow. / National Natural Science Foundation (No. 51439007, 11672213, and 11872285); Open Funding of State Key Laboratory of Water Resources and Hydropower Engineering Science (WRHES), Wuhan University (Project No: 2018HLG01)
5

Stochastic Simulation of the Suspended Sediment Deposition in the Channel With Vegetation and Its Relevance to Turbulent Kinetic Energy

Yang, L., Huai, W., Guo, Yakun 22 March 2022 (has links)
Yes / The aquatic vegetation patch plays a significant role on sediment net deposition in the vegetated channels. Particularly, the flow is decelerated at the leading edge of a patch that tends to induce vertical updraft, that is, a diverging flow region, in which vegetation greatly affects the pattern of sediment net deposition. This study focuses on the simulation of the sediment net deposition in the whole vegetation patch region through an innovative random displacement model, a Lagrange method, with probability-based boundary conditions, instead of the reflection or sorption boundary at the channel bottom. The probability model of deposition and resuspension is proposed according to the flow field characteristics in the different regions of the vegetation patch. The variation of the sediment deposition and resuspension with the turbulent kinetic energy is analyzed to illustrate the effect of the turbulence induced by vegetation, represented by the dimensionless turbulent kinetic energy (ψ), on the sediment deposition and resuspension. The sediment deposition predicted by the proposed model agrees well with the experimental measurements. Results show that the effect of vegetation on the sediment deposition and resuspension motions begins to prevail when the vegetation-induced ψ is larger than its threshold, ψ *. The threshold of ψ is predicted to be within 6.8–10 according to the simulation results in this study. As the turbulent kinetic energy increases, the deposition probability decreases continuously when ψ > ψ *. / ational Natural Science Foundation of China (NSFC). Grant Numbers: 52020105006, 11872285; UK Royal Society - International Exchanges Program. Grant Number: IES\R2\181122; Open Funding of State Key Laboratory of Water Resources and Hydropower Engineering Science (WRHES), Wuhan University. Grant Number: 2018HLG01
6

Regras, normas e padrões no comércio internacional: o Protocolo de Cartagena sobre Biossegurança e seus efeitos potenciais para o Brasil / Rules, Norms and Standards in the international market: the Cartagena Protocol on Biosafety and its potential effects for Brazil

Simões, Débora da Costa 01 April 2008 (has links)
O estabelecimento de regras, normas e padrões internacionais relacionados ao comércio de produtos geneticamente modificados é bastante complexo e envolve uma diversidade de interesses. Essa complexidade pode ser evidenciada pela demora em se definir a forma de operacionalizar o Protocolo de Cartagena sobre Biossegurança - PCB. O PCB estabelece normas e padrões para regulamentar o comércio transfronteiriço de organismos vivos modificados com o objetivo de proteger a biodiversidade. Ele afeta diretamente o mercado internacional de commodities agrícolas, podendo alterar a competitividade dos países. Nesse estudo, calcula-se que o PCB atinge 81,2% das exportações mundiais das principais lavouras GM da atualidade: soja, milho, algodão e canola. Nesse contexto, o Brasil ocupa uma posição peculiar, pois foi o único grande produtor mundial de commodities agrícolas que ratificou o acordo. O objetivo central desse trabalho foi verificar as implicações (em termos de custos) e os impactos potenciais da ratificação do PCB pelo Brasil e seus possíveis efeitos no mercado internacional. A análise centrou-se nas negociações referentes ao Artigo 18 do PCB, que define procedimentos para transporte, manuseio, embalagem e uso de OVMs e restringiu-se ao mercado de soja. Primeiramente, definiu-se uma base teórica para analisar os efeitos de barreiras regulatórias no comércio internacional e no mercado doméstico de exportadores e importadores. Verificou-se que esses efeitos são incertos e dependem da capacidade da medida em questão de resolver ou minimizar falhas de mercado. Posteriormente, calculou-se os custos adicionais de identificação de carregamentos contendo OVMs com base em propostas feitas pelos países-Partes durante as negociações: \'contém\' com fornecimento de uma lista de eventos, \'contém\' com quantificação de eventos, e adoção de um sistema de preservação de identidade. Para fins de comparação, esses cálculos não foram feitos apenas para o Brasil, mas se estenderam para a Argentina e EUA, principais competidores brasileiros no mercado de soja. Os números demonstraram que os custos adicionais de implementação do PCB são mais elevados no Brasil do que nos concorrentes e que essa diferença aumenta à medida que as exigências de identificação tornam-se mais rígidas. Por fim, para verificar o impacto desses custos no mercado internacional, utilizou-se o Equilibrium Displacement Model e definiram-se dois cenários. O Cenário 1 considerou que apenas o Brasil cumpriria as normas de identificação do PCB e o Cenário 2 considerou que Argentina e EUA também adotariam medidas equivalentes. Os resultados evidenciaram que ambas situações implicariam em perdas para o Brasil. Considerando todo o complexo, as perdas poderiam chegar a US$ 133 milhões no Cenário 1 e a US$ 329 milhões no Cenário 2. Apesar das exportações brasileiras de soja em grão terem diminuído nos dois casos, as vendas de farelo e óleo aumentaram no Cenário 1, o que indica um incentivo ao processamento. No Cenário 2, entretanto, apenas as exportações de óleo apresentam bons resultados. Com relação aos outros países, o Cenário 2 apresenta melhores resultados. Dessa forma, espera-se que Argentina e EUA também adotem medidas semelhantes às exigidas pelo PCB. / The development of international rules, norms and standards related to the trade of GM products is complex and involves a diversity of interests. This complexity can be verified by the tough negotiations aiming at establishing procedures to put the Cartagena Protocol on Biosafety - CPB in place. The CPB establishes norms and minimum standards to control the transboundary movements of Living Modified Organisms - LMOs in order to protect the biodiversity. It has a direct effect in the international agricultural commodities market and can even alter the countries\' competitiveness. This work estimates that 81.2% of the main GM crops (soybean, corn, canola and cotton) global exports are affected by the CPB. In this context, Brazil is in a peculiar position, as it was the only country among the biggest world agricultural commodities producers that has ratified the agreement. The main objective of this dissertation was to verify the implications (related to additional costs) and potential impacts of the CPB to Brazil and its possible outcomes for the international market. The analysis was restricted to the Protocol\'s Article 18 - which states the rules related to transport, handling, packing and use of LMOs - and to the soybean international market. First, a theoretical framework was defined in order to analyze the effects of regulatory barriers to the international trade and to the domestic markets of exporters and importers countries. Then, the necessary additional costs to identify the cargoes containing LMOs were calculated considering the main proposals submitted by CPB members during the negotiations: \'contains\' with a list of events, \'contains\' with quantification of events and the adoption of an identity preservation system. In order to compare the CPB effects on different countries, this procedure was not only applied to Brazil, but also to Argentina and the US, two important soybeans exporters that have not signed the agreement. The outcomes revealed that the compliance costs of the CPB requirements are greater in Brazil than its competitors and that this difference increases as the exigencies become stricter. Last, the potential impacts of these additional costs in the international market were estimated using the Equilibrium Displacement Model - EDM. Two scenarios were constructed: under Scenario 1 it was considered that only Brazil complied with CPB standards; under Scenario 2, Argentina and the US also adopted equivalent measures with those established by the Protocol. The results showed that Brazil would be harmed in both situations. Considering the whole soybean complex, the country could loose US$ 133 million under Scenario 1 and US$ 329 million under Scenario 2. Though Brazilian soybean exports decreased in both circumstances, it could be verified that there was a stimulus to meal and oil production in the country under the conditions settled in Scenario 1. In Scenario 2, however, the rise of exports concentrated only in the oil market. Regarding Argentina and the US, the Scenario 2 presented better results that Scenario 1. Therefore, it is almost certain that these countries will comply with CPB requirements. It implies that Brazil will incur in greater losses.
7

Regras, normas e padrões no comércio internacional: o Protocolo de Cartagena sobre Biossegurança e seus efeitos potenciais para o Brasil / Rules, Norms and Standards in the international market: the Cartagena Protocol on Biosafety and its potential effects for Brazil

Débora da Costa Simões 01 April 2008 (has links)
O estabelecimento de regras, normas e padrões internacionais relacionados ao comércio de produtos geneticamente modificados é bastante complexo e envolve uma diversidade de interesses. Essa complexidade pode ser evidenciada pela demora em se definir a forma de operacionalizar o Protocolo de Cartagena sobre Biossegurança - PCB. O PCB estabelece normas e padrões para regulamentar o comércio transfronteiriço de organismos vivos modificados com o objetivo de proteger a biodiversidade. Ele afeta diretamente o mercado internacional de commodities agrícolas, podendo alterar a competitividade dos países. Nesse estudo, calcula-se que o PCB atinge 81,2% das exportações mundiais das principais lavouras GM da atualidade: soja, milho, algodão e canola. Nesse contexto, o Brasil ocupa uma posição peculiar, pois foi o único grande produtor mundial de commodities agrícolas que ratificou o acordo. O objetivo central desse trabalho foi verificar as implicações (em termos de custos) e os impactos potenciais da ratificação do PCB pelo Brasil e seus possíveis efeitos no mercado internacional. A análise centrou-se nas negociações referentes ao Artigo 18 do PCB, que define procedimentos para transporte, manuseio, embalagem e uso de OVMs e restringiu-se ao mercado de soja. Primeiramente, definiu-se uma base teórica para analisar os efeitos de barreiras regulatórias no comércio internacional e no mercado doméstico de exportadores e importadores. Verificou-se que esses efeitos são incertos e dependem da capacidade da medida em questão de resolver ou minimizar falhas de mercado. Posteriormente, calculou-se os custos adicionais de identificação de carregamentos contendo OVMs com base em propostas feitas pelos países-Partes durante as negociações: \'contém\' com fornecimento de uma lista de eventos, \'contém\' com quantificação de eventos, e adoção de um sistema de preservação de identidade. Para fins de comparação, esses cálculos não foram feitos apenas para o Brasil, mas se estenderam para a Argentina e EUA, principais competidores brasileiros no mercado de soja. Os números demonstraram que os custos adicionais de implementação do PCB são mais elevados no Brasil do que nos concorrentes e que essa diferença aumenta à medida que as exigências de identificação tornam-se mais rígidas. Por fim, para verificar o impacto desses custos no mercado internacional, utilizou-se o Equilibrium Displacement Model e definiram-se dois cenários. O Cenário 1 considerou que apenas o Brasil cumpriria as normas de identificação do PCB e o Cenário 2 considerou que Argentina e EUA também adotariam medidas equivalentes. Os resultados evidenciaram que ambas situações implicariam em perdas para o Brasil. Considerando todo o complexo, as perdas poderiam chegar a US$ 133 milhões no Cenário 1 e a US$ 329 milhões no Cenário 2. Apesar das exportações brasileiras de soja em grão terem diminuído nos dois casos, as vendas de farelo e óleo aumentaram no Cenário 1, o que indica um incentivo ao processamento. No Cenário 2, entretanto, apenas as exportações de óleo apresentam bons resultados. Com relação aos outros países, o Cenário 2 apresenta melhores resultados. Dessa forma, espera-se que Argentina e EUA também adotem medidas semelhantes às exigidas pelo PCB. / The development of international rules, norms and standards related to the trade of GM products is complex and involves a diversity of interests. This complexity can be verified by the tough negotiations aiming at establishing procedures to put the Cartagena Protocol on Biosafety - CPB in place. The CPB establishes norms and minimum standards to control the transboundary movements of Living Modified Organisms - LMOs in order to protect the biodiversity. It has a direct effect in the international agricultural commodities market and can even alter the countries\' competitiveness. This work estimates that 81.2% of the main GM crops (soybean, corn, canola and cotton) global exports are affected by the CPB. In this context, Brazil is in a peculiar position, as it was the only country among the biggest world agricultural commodities producers that has ratified the agreement. The main objective of this dissertation was to verify the implications (related to additional costs) and potential impacts of the CPB to Brazil and its possible outcomes for the international market. The analysis was restricted to the Protocol\'s Article 18 - which states the rules related to transport, handling, packing and use of LMOs - and to the soybean international market. First, a theoretical framework was defined in order to analyze the effects of regulatory barriers to the international trade and to the domestic markets of exporters and importers countries. Then, the necessary additional costs to identify the cargoes containing LMOs were calculated considering the main proposals submitted by CPB members during the negotiations: \'contains\' with a list of events, \'contains\' with quantification of events and the adoption of an identity preservation system. In order to compare the CPB effects on different countries, this procedure was not only applied to Brazil, but also to Argentina and the US, two important soybeans exporters that have not signed the agreement. The outcomes revealed that the compliance costs of the CPB requirements are greater in Brazil than its competitors and that this difference increases as the exigencies become stricter. Last, the potential impacts of these additional costs in the international market were estimated using the Equilibrium Displacement Model - EDM. Two scenarios were constructed: under Scenario 1 it was considered that only Brazil complied with CPB standards; under Scenario 2, Argentina and the US also adopted equivalent measures with those established by the Protocol. The results showed that Brazil would be harmed in both situations. Considering the whole soybean complex, the country could loose US$ 133 million under Scenario 1 and US$ 329 million under Scenario 2. Though Brazilian soybean exports decreased in both circumstances, it could be verified that there was a stimulus to meal and oil production in the country under the conditions settled in Scenario 1. In Scenario 2, however, the rise of exports concentrated only in the oil market. Regarding Argentina and the US, the Scenario 2 presented better results that Scenario 1. Therefore, it is almost certain that these countries will comply with CPB requirements. It implies that Brazil will incur in greater losses.
8

A fundamental study on the heat partition ratio of vehicle disc brakes

Loizou, Andreas, Qi, Hong Sheng, Day, Andrew J. January 2013 (has links)
no / The interface tribo-layer (ITL) in an automotive brake friction pair is a layer of material created from transfer films, wear particles, and surface transformations between the rotor and stator. Its presence in a brake friction interface has been proven, e.g. by the existence of a temperature ‘jump’ across the friction interface. In this paper two static transient heat transfer models which force one dimensional heat flow, have been used to investigate the ITL behaviour and obtain an equivalent thermal conductance value. The ITL equivalent thermal conductance value is important as it reduces computational requirements and software restrictions encountered in the physical model of the ITL. This approach is developed into a more realistic two-dimensional coupled temperature-displacement model using commercial FEA software (ABAQUS). A newly developed relationship that utilises the contact pressure, real contact area, and the ITL equivalent thermal conductance, has been used to estimate the effective thermal conductance at the friction interface. Subsequently the effective thermal conductance relationship is combined with the 2-D coupled temperaturedisplacement model. The combination of this relationship with the 2D FE model provides a new method of heat partition prediction in brake friction pairs. Heat partition at a brake friction interface is confirmed to be neither uniform nor constant with time. / IMechE / The full text will not be made available in Bradford Scholars due to the publisher's copyright policies.

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