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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.
481

National competitiveness of Vietnam : determinants, emerging key issues and recommendations

Nguyen, Hien Phuc. January 2008 (has links)
Zugl.: Leipzig, Univ., Diss., 2008 / Includes bibliographical references.
482

Optimization of industrial shop scheduling using simulation and fuzzy logic

Rokni, Sima. January 2010 (has links)
Thesis (M. Sc.)--University of Alberta, 2010. / Title from pdf file main screen (viewed on June 22, 2010). A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science in Construction Engineering and Management, Department of Civil and Environmental Engineering, University of Alberta. Includes bibliographical references.
483

Numerical modelling of heat transfer and thermal stresses in gas turbine guide vanes

Rahman, Faisal. January 2003 (has links)
Thesis (M. Eng.(Mechanical))--University of Pretoria, 2003. / Includes summary. Includes bibliographical references (leaves 87-90).
484

A diagnostic and remedial study of potentially and actually failing students at Purdue University

Remmers, H. H. January 1928 (has links)
Thesis (Ph. D.)--University of Iowa, 1927. / On cover: Bulletin of Purdue University, vol. XXVIII, no. 12. Without thesis note.
485

Prediction of job completion times and optimal overtime allocation for satisfying production due dates /

Liu, Olivia. January 2006 (has links)
Thesis (M.S.)--Rochester Institute of Technology, 2006. / Typescript. Includes bibliographical references (leaves 79-81).
486

Exploring the relationships between influencing factors and performance for construction joint ventures /

Chen, Hua, January 2006 (has links)
Thesis (Ph. D.)--University of Hong Kong, 2006. / Also available online.
487

Adoption of irrigation scheduling methods in South Africa

Stevens, Joseph Benjamin. January 2006 (has links)
Thesis (Ph.D.)(Agricultural Economics)--University of Pretoria, 2006. / Includes summary. Includes bibliographical references. Available on the Internet via the World Wide Web.
488

Modelagem e simulação para a eficiência em uma fornalha de 1,2 Dicloroetano.

SANTOS, Jorge Luiz Moura dos. 05 February 2018 (has links)
Submitted by Dilene Paulo (dilene.fatima@ufcg.edu.br) on 2018-02-05T12:19:11Z No. of bitstreams: 1 JORGE lUIZ MOURA DOS SANTOS – DISSERTAÇÃO PPGEQ 2009.pdf: 1242850 bytes, checksum: 4b01984b14177e53d87f83f20fe95699 (MD5) / Made available in DSpace on 2018-02-05T12:19:11Z (GMT). No. of bitstreams: 1 JORGE lUIZ MOURA DOS SANTOS – DISSERTAÇÃO PPGEQ 2009.pdf: 1242850 bytes, checksum: 4b01984b14177e53d87f83f20fe95699 (MD5) Previous issue date: 2009 / O processo de combustão tem grande importância para o desenvolvimento industrial. Nos últimos anos o setor industrial Brasileiro vem sofrendo seguidos aumentos no preço do gás natural e a legislação ambiental é cada vez mais restritiva, principalmente no que tange a emissões atmosféricas. O setor industrial, principalmente as empresas que tem como concorrência direta os produtos importados, concorre cada vez mais com mercados competitivos sendo necessária a redução de custos variáveis de produção. Tanto do ponto de vista econômico como ambiental é fundamental o profundo conhecimento e controle das reações de combustão que ocorrem nas fornalhas de craqueamento para a adoção de medidas de maior eficiência energética que resultem um aproveitamento mais racional de energia e uma menor disposição de poluentes como, por exemplo, CO e NOx. Este trabalho apresenta uma analise metodológica estruturada para avaliar a eficiência da combustão em uma fornalha de craqueamento de 1,2 Dicloroetano pelos métodos direto e indireto, assim como as perdas térmicas na fornalha e a carga efetivamente útil para o sistema. A eficiência de uma fornalha é obtida pela determinação da percentagem da energia fornecida para a fornalha e as percentagens de perdas térmicas devido aos vários fenômenos naoperação da fornalha. / The Combustion process has great importance to the industrial development. In recent years the Brazilian Industrial sector comes suffering increases in the prices from the natural gas and the environment legislation is each more restrictive time. The sector industrial mainly the companies who have as direct competition the imported products concur each time more with competitive market being necessary the reduction of changeable costs of production. As much of the economic point of view as environment is basic the deep knowledge and control of the combustion reaction that occur in the cracking furnace for the adoption of measures of bigger energy efficient that a more rational exploitation of the energy and a lesser disposal of pollutants results as for example CO and NOx. This work presents a structuralized methodological analyzes to evaluated the combustion´s efficiency in a cracking furnace of 1,2 Ethane Dichloride for the direct and indirect method as well as the thermal losses in the furnaces and the effectively useful load for the system. The efficiency of a furnace is gotten by the determination of the percentage of the energy supplied to the furnace and the percentages of thermal losses due some phenomena in the operation of the furnace. The evaluated thermal losses in this work had been the losses of the gases of combustion, the wall of the furnace and the losses due to the fuel that did not burn. In this work also the behavior of the efficiency of the furnace with the variation of the level of air excess was evaluated for the combustion.
489

Sistemas de controle solar e ações de retrofitting

Nuss, Claudio Andre January 2018 (has links)
Os sistemas de controle solar auxiliam no controle da radiação solar incidente no envoltório, e, de acordo com a NBR 15220-3, é recomendável seu uso para a zona bioclimática 3, na cidade de Porto Alegre. Assim, com a ação de retrofitting, é possível utilizar os sistemas de controle solar como modo de adaptar o envoltório das edificações ao clima local e aos padrões de consumo atuais. Dessa forma, o retrofitting do envoltório pode contribuir com a redução do consumo energético e a dependência de sistemas de refrigeração e aquecimento mecânico. Logo, o objetivo da dissertação é qualificar e quantificar energeticamente os sistemas de controle solar com vistas à redução do consumo energético nos ambientes construídos. Um estudo de caso foi realizado na cidade de Porto Alegre, onde um edifício foi selecionado perante um conjunto de edificações existentes. Com o auxílio de um método expedito de cálculo energético, foi realizada a avaliação energética do envoltório da edificação atual e do seu retrofitting proposto. A edificação passou de nível energético E para nível A, comprovando o êxito do estudo de retrofitting aplicado. A pesquisa concluiu que, alinhado com o encontrado na revisão da literatura, as edificações com grandes aberturas orientadas para oeste são um equívoco de projeto no clima de Porto Alegre e que as ações de retrofitting são uma alternativa de adaptação ao clima local, tornando os edifícios eficientes energeticamente. / Shading systems help to control the incident solar radiation on the envelope, and, according to NBR 15220-3, its use is recommended for the bioclimatic zone 3, in the city of Porto Alegre. Hence, with retrofitting, it is possible to use shading systems as a way of adapting the building envelope to the local climate and current consumption patterns. Thus, the retrofitting of the envelope can contribute to the reduction of the energy consumption and of the dependence on systems of refrigeration and mechanical heating. Therefore, the objective of this dissertation is to qualify and quantify the energy of shading systems in order to reduce energy consumption in built environments. Thus, a case study was conducted in the city of Porto Alegre, where a building was selected from a set of existing buildings. We performed an energetic evaluation of current envelope of buildings and its proposed retrofitting by using a facilitated method for energy calculation. The buildings moved from energy level E to level A, proving the success of the study on the applied retrofitting. We conclude that, as also shown in literature review; buildings with large openings oriented to the west in Porto Alegre are a design misconception due to the city’s climate. Thus, retrofitting actions are alternative ways to adapt to the local climate so that buildings are energy efficient.
490

Production efficiency and policy impact of heterogeneous farm households in developing countries

Embaye, Weldensie Teklay January 1900 (has links)
Doctor of Philosophy / Department of Economics / Jason S. Bergtold / Benjamin B. Schwab / Agricultural development is an essential factor in the economic development of much of the developing world and comprises a significant element of foreign assistance portfolios. Over the last decade, there has seen a renewed interest in more credible estimates of the economic impacts of development programs, such as assistance to extension programs. We compare the estimation of technical efficiency to farm output and income as an outcome variable to evaluate the impact of development programs such as farm education and extension programs. We develop a simple theoretical model which shows that using technical efficiency as an outcome variable could be a viable alternative to more traditionally used outcome variables such as farm output and farm profit. We note that when farmers are capital constrained, extension programs can theoretically have a large efficiency effect despite a small or zero change in farm profits. If farm technical efficiency is used as an outcome variable, then it must be estimated correctly. Mismeasurement of farm technical efficiency leads to misleading extension program evaluations. Farm households face heterogeneous infrastructural constraints (Suri 2011; Ojiem et al. 2006), credit constraints, information barriers and other input market constraints (Duflo, Kremer and Robinson 2011; Jack 201; Suri 2011and Stifel and Minten 2008), labor markets constraints (Henning and Henningsen 2007), socio-economical (Ojiem et al. 2006) and non-farm income opportunities (Chang et al. 2012) and thus have different access to agricultural inputs and outputs. These constraints have a substantial impact on agricultural production decisions of farm households. A key production decision of farm households is the allocation of resource to cash and food crops. Production of cash crops requires relatively higher market involvement in both the purchase of inputs and the selling of output than home-consumed food crops. The heterogeneous constraints across farm households leads to a substantial imbalance in the transaction costs associated with the production of each crop. Moreover, home-consumed crops may have quality attributes (e.g. color, taste, softness of dough, and suitability for certain dishes) not reflected in market prices. Factors such as transaction costs, crop quality attributes, and other factors such as household characteristics are farmer specific and drive a heterogeneous price wedge between the market prices for household’s crop production and the economic value of these crops for the household. These distinctions have important implication for farm productivity analysis, such as technical efficiency measurement. The standard approach to productivity analysis, such as efficiency estimation, assume that farm households face homogenous price wedges that leads to homogenous set of production and profit functions. However, the price gap created by transaction costs, crop quality attributes, and other factors such as household characteristics generally vary among subsistence, semi-subsistence and commercial farmers and leads to a heterogeneous set of profit and production frontiers. Subsistence and semi-subsistence farmers who produce largely home consumed crops have potentially greater price wedges than commercial farmers. Failing to account for the heterogeneity in price wedges that drive heterogeneity profit and production frontiers is likely to lead to underestimation of the efficiency of subsistence and semi-subsistence farmers. We test if traditional productivity analysis indeed underestimates the efficiency of subsistence and semi-subsistence farmers by employing a conditional Data Envelopment Analysis (DEA) model for household survey data in Uganda. Results confirm that naïve estimates of efficiency understate the efficiency scores of subsistence and semi-subsistence farmers. The results cast doubt on policies, such as extension programs or other information treatments, that interpret low efficiency scores for subsistence and semi-subsistence farmers as a management shortfall. We demonstrate the use of farm technical efficiency as an outcome measure by analyzing data from 2008-2012 for farm training program in Armenia. In this program, farmers received technical guidance on modern farm techniques. Two previous evaluations (Schwab and Shanoyan 2016; Fortson et al. 2012) find ambiguous evidence that farm profits increased. The measurement or potential gain from an extension program is captured using farm technical efficiency measures. We find evidence that the program in Armenia increased farm technical efficiency from 2008 to 2012.

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