• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 60
  • 16
  • 8
  • 2
  • 1
  • Tagged with
  • 139
  • 139
  • 139
  • 56
  • 36
  • 29
  • 28
  • 22
  • 21
  • 21
  • 20
  • 20
  • 20
  • 19
  • 18
  • 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.
11

Evaluating water quality impacts of alternative management practices through development of a BMP database

Butler, Gary Brooks, January 2007 (has links) (PDF)
Thesis (M.S.)--Auburn University, 2007. / Abstract. Vita. Includes bibliographic references (ℓ. 111-121)
12

Assessment of application, effectiveness, and compliance of forestry best management practices in West Virginia

Goff, William A. January 2005 (has links)
Thesis (M.S.)--West Virginia University, 2005. / Title from document title page. Document formatted into pages; contains ix, 109 p. : ill. (some col.), maps (part col.). Includes abstract. Includes bibliographical references (p. 103-105).
13

Simulating the effects of riparian zone delineation and management practices on landscape pattern and timber production

Bellchamber, Sara B. January 2004 (has links)
Thesis (M.S.) University of Missouri-Columbia, 2004. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (June 29, 2006) Vita. Includes bibliographical references.
14

Modeling the influence of climate and management practices on water quality in Goodwater Creek experimental watershed

Bockhold, Amanda Koelling. January 2006 (has links)
Thesis (M.S.) University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on August 21, 2007) Includes bibliographical references.
15

River restoration in the upper Mississippi River Basin

O'Donnell, Thomas Kevin. January 2006 (has links)
Thesis (M.S.) University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on August 27, 2007) Includes bibliographical references.
16

Custos de produção, análise econômica e gerencial em unidades de produção de alevinos de peixes reofílicos : estudo de caso em Rondônia / Production costs, economic analysis and management control in reophilic fish unit: case study in Rondônia

Guerreiro, Luis Ricardo Jayme January 2012 (has links)
O objetivo deste trabalho foi de avaliar economicamente uma unidade de produção de alevinos de espécies reofílicas do estado de Rondônia e desta forma estruturar a análise de custos, econômica e gerencial do empreendimento. O empreendimento avaliado possui 54 ha de área total e 6,5 ha de lâmina d’água disponíveis para a alevinagem. Na safra 2010/2011 o empreendimento produziu os seguintes produtos: alevinos de tambaqui (Colossoma macropomum) nos tamanhos de 3g, 5g, 10g, 15g, 20g e 30g; alevinos de piavuçu (Leporinus macrocephalus); e alevinos de curimba (Prochilodus lineatus). O empreendimento ainda comprou e revendeu alevinos de pirarucu (Arapaima gigas) e alevinos de Jundiara (♀ Pseudoplathystoma fasciatum X ♂ Leiarius marmoratus). A fim de avaliar como a produção de alevinos consumiu os recursos disponíveis do empreendimento, realizou-se o mapeamento do fluxo de produção do empreendimento e de sua estrutura que custos . Foram calculados os seguintes indicadores de custo e rentabilidade: custo operacional efetivo e total, custo total de produção, receita liquida e lucro, além dos indicadores de fluxo de caixa usuais e seus alternativos integrados, ponto de nivelamento e margem de contribuição total. Através do mapeamento do fluxo de produção verificou-se que o plantel de reprodutores apresenta resultados reprodutivos satisfatórios, porém o empreendimento apresenta falhas no manejo de arraçoamento de reprodutores e alevinos e não realiza o controle dos estoques de alevinos e dos parâmetros de qualidade de água nos viveiros. Entre os produtos efetivamente produzidos no empreendimento, os que apresentaram os menores custos médios e as melhores rentabilidades estão os alevinos de tambaqui de 3g, 5g e os alevinos de piavuçu. A análise custos e econômica mostrou que empreendimento apresenta uma baixa lucratividade a médio prazo em relação ao capital investido e economicamente inviável a longo prazo, devido a sua onerosa estrutura de produção. Diante destes resultados fica evidente que as tomadas de decisão para determinação de valores de investimento e preço de venda dos produtos são realizadas sem todas as informações necessárias para o adequado planejamento do empreendimento, o que mostra a importância do contínuo controle dos processos e avaliação econômica deste tipo de empreendimento. / The objective of this study was to evaluate a unit cost of production of fingerlings of reophilic species in the state of Rondônia, Brazil, and thereby structure the cost analysis, and the economic management of the enterprise. The enterprise has 54 ha and 6.5 ha of water is available for the nursery. In the season 2010/2011 the enterprise produced the following products: fingerlings of tambaqui (Colossoma macropomum) in 3g, 5g, 10g, 15g, 20g and 30g weights; piavuçu fingerlings (Leporinus macrocephalus) and curimba fingerlings (Prochilodus lineatus). The venture has bought and resold pirarucu fingerlings (Arapaima gigas) and jundiara fingerlings (♀ Pseudoplathystoma fasciatum X ♂ Leiarius marmoratus). In order to evaluate how the production of fingerlings consumed the resources of the enterprise, was conducted the flow map of production of the enterprise and its cost structure. Was calculated the following indicators of cost and profitability, and total operational cost, total cost of production, net income and earnings, and indicators of cash flow and its usual alternative integrated point of leveling and total contribution margin. By mapping the production flow it was found that the bloodstock breeding presents satisfactory results, but the venture fails in the management and feeding of fingerlings and does not perform the control of fingerlings stocks and the parameters of water quality. Among the products actually produced in the enterprise, who had the lowest average costs and better returns are 3 g and 5 g tambaqui fingerlings, and piavuçu fingerlings. The analysis showed that costs and economic analysis has low profitability in the medium term in relation to capital invested and economically unviable in the long term, due to its costly production structure. Given these results it is evident that the decision making process for determining values of investment and the selling price of the products are made without all the information necessary for proper planning of the enterprise, which shows the importance of continuous control process and economic evaluation of this type of business venture.
17

EFFECT OF MAJOR FACTORS ON BIOSWALE PERFORMANCE AND HYDROLOGIC PROCESSES FOR THE CONTROL OF STORMWATER RUNOFF FROM HIGHWAYS

Akhavan Bloorchian, Azadeh 01 May 2018 (has links)
Highways and roadways are the major source of stormwater runoff due to their prevalence and large non-permeable surface area. Best Management Practices (BMPs) such as bioswale provide effective on-site management and control of stormwater runoff from linear infrastructure such as highways. Many factors affect the performance of bioswales for stormwater volume reduction. The ratio of the installed BMP area to its service drainage area, characteristics of precipitation and the amount of sediment build-up over the surface of the BMP area are among the most important factors. Earlier studies have indicated that volume reductions in stormwater runoff from bioswale application range from 50% to 94%. However, the reported research lacks adequate information for a full understanding of how bioswales perform under various conditions. Consequently, additional systematic and in-depth research to better understand and the potential of bioswales as a method of controlling stormwater runoff is indicated. This research examined the effect of the following factors on bioswale performance: the ratio of the BMP area to the service drainage area, precipitation amounts and intensity, and sediment build-up. Hydraulic and hydrological processes were developed and analyzed through conceptual and physical models using appropriate governing equations including the Green-Ampt method. Field study of discrete rainfall events was conducted to collect information to calibrate and validate the numerical models. The field study tested various bioswale conditions with different levels of sediment accumulation. It also considered expected soil loss in the study area using the Universal Soil Loss Equation (USLE) method. In addition to field study, extensive simulations were conducted considering various contributing areas, rainfall depth and intensity, and sediment accumulation. These variables were manipulated to evaluate their effect on runoff volume reduction. Findings indicate that, for a given rainfall depth and duration, increasing the ratio of the BMP area to the service drainage area from 4% to16% results in increased bioswale efficiency ranging from 84% to 99%. The results revealed that input flowrate to the bioswale ranged from 0.04 to 4.7 in./min. depending on the rainfall intensity and soil type in the area. The runoff reduction performance of a newly constructed bioswale ranged from 44% for the highest input flowrate to 99% for the lowest input flowrate rainfall events. On the low end of rainfall volume/intensity, a 4% increase in the BMP area ratio results in a 34% improvement in efficiency (50% to 84%). On the high end of rainfall volume/intensity, a 16% increase in the area ratio results in only a 5% increase in efficiency (94% to 99%). Results also show that sediment accumulation has a substantial negative effect on infiltration rate. The observed efficiency of a bioswale in runoff reduction ranged from 13% to 100%. According to the USLE, the expected amount of soil loss occurring in the right-of-way area of a highway is approximately 1 ton/acre annually. The research revealed that for a given rainfall depth, duration, and area ratio; increasing the amount of sediment accumulation from 0 lbs./sq. ft. (equivalent to a newly constructed bioswale) to 2.7 lbs./sq. ft. (equivalent to a 10-year old bioswale) results in a 52% reduction in the runoff effectiveness of the bioswale sub-catchment from 98% to 46%. Finally, the physical model and associated governing equations were analyzed to describe the process of each studied factor. These results can be used for further study where the sediment accumulation rates differ from those modeled in this research.
18

Custos de produção, análise econômica e gerencial em unidades de produção de alevinos de peixes reofílicos : estudo de caso em Rondônia / Production costs, economic analysis and management control in reophilic fish unit: case study in Rondônia

Guerreiro, Luis Ricardo Jayme January 2012 (has links)
O objetivo deste trabalho foi de avaliar economicamente uma unidade de produção de alevinos de espécies reofílicas do estado de Rondônia e desta forma estruturar a análise de custos, econômica e gerencial do empreendimento. O empreendimento avaliado possui 54 ha de área total e 6,5 ha de lâmina d’água disponíveis para a alevinagem. Na safra 2010/2011 o empreendimento produziu os seguintes produtos: alevinos de tambaqui (Colossoma macropomum) nos tamanhos de 3g, 5g, 10g, 15g, 20g e 30g; alevinos de piavuçu (Leporinus macrocephalus); e alevinos de curimba (Prochilodus lineatus). O empreendimento ainda comprou e revendeu alevinos de pirarucu (Arapaima gigas) e alevinos de Jundiara (♀ Pseudoplathystoma fasciatum X ♂ Leiarius marmoratus). A fim de avaliar como a produção de alevinos consumiu os recursos disponíveis do empreendimento, realizou-se o mapeamento do fluxo de produção do empreendimento e de sua estrutura que custos . Foram calculados os seguintes indicadores de custo e rentabilidade: custo operacional efetivo e total, custo total de produção, receita liquida e lucro, além dos indicadores de fluxo de caixa usuais e seus alternativos integrados, ponto de nivelamento e margem de contribuição total. Através do mapeamento do fluxo de produção verificou-se que o plantel de reprodutores apresenta resultados reprodutivos satisfatórios, porém o empreendimento apresenta falhas no manejo de arraçoamento de reprodutores e alevinos e não realiza o controle dos estoques de alevinos e dos parâmetros de qualidade de água nos viveiros. Entre os produtos efetivamente produzidos no empreendimento, os que apresentaram os menores custos médios e as melhores rentabilidades estão os alevinos de tambaqui de 3g, 5g e os alevinos de piavuçu. A análise custos e econômica mostrou que empreendimento apresenta uma baixa lucratividade a médio prazo em relação ao capital investido e economicamente inviável a longo prazo, devido a sua onerosa estrutura de produção. Diante destes resultados fica evidente que as tomadas de decisão para determinação de valores de investimento e preço de venda dos produtos são realizadas sem todas as informações necessárias para o adequado planejamento do empreendimento, o que mostra a importância do contínuo controle dos processos e avaliação econômica deste tipo de empreendimento. / The objective of this study was to evaluate a unit cost of production of fingerlings of reophilic species in the state of Rondônia, Brazil, and thereby structure the cost analysis, and the economic management of the enterprise. The enterprise has 54 ha and 6.5 ha of water is available for the nursery. In the season 2010/2011 the enterprise produced the following products: fingerlings of tambaqui (Colossoma macropomum) in 3g, 5g, 10g, 15g, 20g and 30g weights; piavuçu fingerlings (Leporinus macrocephalus) and curimba fingerlings (Prochilodus lineatus). The venture has bought and resold pirarucu fingerlings (Arapaima gigas) and jundiara fingerlings (♀ Pseudoplathystoma fasciatum X ♂ Leiarius marmoratus). In order to evaluate how the production of fingerlings consumed the resources of the enterprise, was conducted the flow map of production of the enterprise and its cost structure. Was calculated the following indicators of cost and profitability, and total operational cost, total cost of production, net income and earnings, and indicators of cash flow and its usual alternative integrated point of leveling and total contribution margin. By mapping the production flow it was found that the bloodstock breeding presents satisfactory results, but the venture fails in the management and feeding of fingerlings and does not perform the control of fingerlings stocks and the parameters of water quality. Among the products actually produced in the enterprise, who had the lowest average costs and better returns are 3 g and 5 g tambaqui fingerlings, and piavuçu fingerlings. The analysis showed that costs and economic analysis has low profitability in the medium term in relation to capital invested and economically unviable in the long term, due to its costly production structure. Given these results it is evident that the decision making process for determining values of investment and the selling price of the products are made without all the information necessary for proper planning of the enterprise, which shows the importance of continuous control process and economic evaluation of this type of business venture.
19

Custos de produção, análise econômica e gerencial em unidades de produção de alevinos de peixes reofílicos : estudo de caso em Rondônia / Production costs, economic analysis and management control in reophilic fish unit: case study in Rondônia

Guerreiro, Luis Ricardo Jayme January 2012 (has links)
O objetivo deste trabalho foi de avaliar economicamente uma unidade de produção de alevinos de espécies reofílicas do estado de Rondônia e desta forma estruturar a análise de custos, econômica e gerencial do empreendimento. O empreendimento avaliado possui 54 ha de área total e 6,5 ha de lâmina d’água disponíveis para a alevinagem. Na safra 2010/2011 o empreendimento produziu os seguintes produtos: alevinos de tambaqui (Colossoma macropomum) nos tamanhos de 3g, 5g, 10g, 15g, 20g e 30g; alevinos de piavuçu (Leporinus macrocephalus); e alevinos de curimba (Prochilodus lineatus). O empreendimento ainda comprou e revendeu alevinos de pirarucu (Arapaima gigas) e alevinos de Jundiara (♀ Pseudoplathystoma fasciatum X ♂ Leiarius marmoratus). A fim de avaliar como a produção de alevinos consumiu os recursos disponíveis do empreendimento, realizou-se o mapeamento do fluxo de produção do empreendimento e de sua estrutura que custos . Foram calculados os seguintes indicadores de custo e rentabilidade: custo operacional efetivo e total, custo total de produção, receita liquida e lucro, além dos indicadores de fluxo de caixa usuais e seus alternativos integrados, ponto de nivelamento e margem de contribuição total. Através do mapeamento do fluxo de produção verificou-se que o plantel de reprodutores apresenta resultados reprodutivos satisfatórios, porém o empreendimento apresenta falhas no manejo de arraçoamento de reprodutores e alevinos e não realiza o controle dos estoques de alevinos e dos parâmetros de qualidade de água nos viveiros. Entre os produtos efetivamente produzidos no empreendimento, os que apresentaram os menores custos médios e as melhores rentabilidades estão os alevinos de tambaqui de 3g, 5g e os alevinos de piavuçu. A análise custos e econômica mostrou que empreendimento apresenta uma baixa lucratividade a médio prazo em relação ao capital investido e economicamente inviável a longo prazo, devido a sua onerosa estrutura de produção. Diante destes resultados fica evidente que as tomadas de decisão para determinação de valores de investimento e preço de venda dos produtos são realizadas sem todas as informações necessárias para o adequado planejamento do empreendimento, o que mostra a importância do contínuo controle dos processos e avaliação econômica deste tipo de empreendimento. / The objective of this study was to evaluate a unit cost of production of fingerlings of reophilic species in the state of Rondônia, Brazil, and thereby structure the cost analysis, and the economic management of the enterprise. The enterprise has 54 ha and 6.5 ha of water is available for the nursery. In the season 2010/2011 the enterprise produced the following products: fingerlings of tambaqui (Colossoma macropomum) in 3g, 5g, 10g, 15g, 20g and 30g weights; piavuçu fingerlings (Leporinus macrocephalus) and curimba fingerlings (Prochilodus lineatus). The venture has bought and resold pirarucu fingerlings (Arapaima gigas) and jundiara fingerlings (♀ Pseudoplathystoma fasciatum X ♂ Leiarius marmoratus). In order to evaluate how the production of fingerlings consumed the resources of the enterprise, was conducted the flow map of production of the enterprise and its cost structure. Was calculated the following indicators of cost and profitability, and total operational cost, total cost of production, net income and earnings, and indicators of cash flow and its usual alternative integrated point of leveling and total contribution margin. By mapping the production flow it was found that the bloodstock breeding presents satisfactory results, but the venture fails in the management and feeding of fingerlings and does not perform the control of fingerlings stocks and the parameters of water quality. Among the products actually produced in the enterprise, who had the lowest average costs and better returns are 3 g and 5 g tambaqui fingerlings, and piavuçu fingerlings. The analysis showed that costs and economic analysis has low profitability in the medium term in relation to capital invested and economically unviable in the long term, due to its costly production structure. Given these results it is evident that the decision making process for determining values of investment and the selling price of the products are made without all the information necessary for proper planning of the enterprise, which shows the importance of continuous control process and economic evaluation of this type of business venture.
20

Evaluating the Effects of Watershed Land Use Distribution and BMP Data on HSPF  Water Quality Predictions

Alukwe, Isaac A. 23 April 2013 (has links)
Preventing impairment of waterbodies requires control, reduction and interception of contaminant losses at the field and subwatershed level. Three specific research objectives were accomplished in this study: 1) compare the HSPF-predicted flow, sediment, total nitrogen (TN) and total phosphorus (TP) loads resulting from simulation of spatially distributed site-specific and county-level disaggregated land use data at subwatershed and watershed levels, 2) evaluate the effects of site-specific and county-level disaggregated BMP data on modeled BMP responses in HSPF-predicted flow, sediment, TN and TP loads at the watershed level, and 3) analyze the long-term effects of the two spatial BMP datasets on achieving the Chesapeake Bay Total Maximum Daily Load (TMDL) goals for sediment, TN and TP. Site-specific data are derived from the local watershed inventory while disaggregated data are based on county-level aggregated data that are distributed to portions of river segments that intersect each county. The study site was the Upper Opequon Watershed in northern Virginia. Results for each research objective are as follows: (1) HSPF-predicted flow, sediment, TN and TP were higher using disaggregated land use data in subwatersheds at monthly and annual time-steps. (2) Predicted load reductions were higher with site-specific BMP data than with disaggregated data for the study watershed. (3) Current levels of cost-shared BMP implementation in the Upper Opequon Watershed using either site-specific or county-level disaggregated BMP datasets do not meet the Chesapeake Bay TMDL goals. Increasing BMP implementation level to 100% of the available land also failed to meet TMDL target goals. Generally, use of disaggregated land use data does not accurately represent the existing watershed conditions. Further, for the study watershed, use of disaggregated county-level BMP data poorly represented actual watershed conditions, which resulted in higher pollutant yields and higher levels of BMPs needed to meet water quality goals. The study suggests that site-specific land use and BMP data must be used during TMDL implementation planning to maintain credibility with local stakeholders and improve the accuracy of the developed implementation plans. / Ph. D.

Page generated in 0.1165 seconds