• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 277
  • 37
  • 18
  • 16
  • 11
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 422
  • 422
  • 422
  • 87
  • 86
  • 75
  • 75
  • 62
  • 56
  • 51
  • 47
  • 47
  • 47
  • 39
  • 39
  • 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

[en] A STUDY OF THE DISTRIBUITION OF 2,4-D HERBICIDE IN AGRICULTURAL SOILS OF THE REGION OF SÃO PEDRO DA SERRA -RJ, AND ITS ENVIRONMENTAL SIGNIFICANCE / [pt] ESTUDO SOBRE A DISTRIBUIÇÃO DO HERBICIDA 2,4-D NOS SOLOS DA REGIÃO DE SÃO PEDRO DA SERRA-RJ E SUA IMPORTÂNCIA AMBIENTAL

JOEDY PATRICIA CRUZ QUEIROZ 12 June 2008 (has links)
[pt] A região de São Pedro da Serra tem uma tradição de cultivar a terra com dois tipos manejo principalmente: o pousio, que é baseado na rotação de pequenas áreas, alternadas por um período de descanso da terra e o cultivo tradicional com a utilização de agrotóxicos. Esta pesquisa pretende entender a fixação e mobilização do herbicida ácido diclofenoxiacético (2,4-D) a partir das características do solo e seu tipo de manejo. A área de estudo foi dividida em quatro, classificadas a partir de seu uso: sistema 1 (pousio de 4-7 anos), sistema 2 (pousio de 10-12 anos), sistema 3 (plantio convencional), e sistema 4 (área de floresta). E em três profundidades que variaram de 0-10cm, 10-20cm e 25-40cm. O estudo constituiu em um comparativo entre os resultados dos ensaios de caracterização mineralógica, micromorfologia dos solos, fracionamento físico e fracionamento químico da matéria orgânica do solo e quantificação do herbicida escolhido através de cromatografia líquida. Os dados de cromatografia determinaram a presença do herbicida 2,4-D em todos os sistemas estudados. A concentração de 2,4-D teve uma correlação positiva com o teor de argila presente nos sistemas e negativo com a concentração de Al 3+ e H +. O estudo constatou ainda, que o manejo de pousio é o mais apropriado, pois regenera as propriedades físicas e químicas do solo, dando os subsídios necessários para a sua boa utilização agrícola, além de não necessitar da utilização intensa de agrotóxicos, evitando deste modo a possível contaminação dos mananciais hídricos. / [en] The São Pedro da Serra Region has two types of tillage for the sowing soil, the shifting cultivation is based on the soil area rotation and the traditional utilize high amount of agro-toxics products. The aim of this work is to study the 2,4 D herbicide fixation and mobilization from the soil characteristics and the tillage. The cultivated areas were divided depending of the sow time as: system 1 (shifting cultivation 4-7 years), system 2 (shifting cultivation 10-12 years), system 3 (traditional sow), system 4 (forest area). Three different depths were selected (0-10 cm, 10-20 cm, 25-40 cm). The four different systems were compared using the mineralogical characterization, the soil micro morphology, the physic and chemic fractionation for the organic material and the herbicide quantification by the HPLC technique. The semi quantitative results using the HPLC verify the 2,4- D herbicide contains for all the studied systems. The 2,4-D concentration have correlation with the amount of clay of the soil, and have correlation negative with the amount of Al3+ and H+. The relation depends on the herbicide and soil chemical characteristics. The study found that the shifting cultivation had the best 2,4-D elimination, The shifting cultivation soil management permit the better soil regeneration of the chemical and physical properties and the agro-toxic use reduction and the hydro source contamination.
192

Alterações ambientais decorrentes da presença de depósitos tecnogênicos na bacia hidrográfica do Ribeirão Anicuns em Goiânia, GO /

Brito, Gisele Silveira de. January 2011 (has links)
Orientador: José Eduardo Zaine / Banca: Antonio Roberto Saad / Banca: Julio Cezar Rubin de Rubin / Resumo: O presente trabalho consiste no estudo e avaliação das alterações no meio ambiente decorrentes da presença de depósitos tecnogênicos na bacia hidrográfica do ribeirão Anicuns, na região sudoeste da cidade de Goiânia, Goiás. Os depósitos tecnogênicos são testemunhos da ação geológica humana e revelam características da transformação do ambiente natural pelas diferentes formas de apropriação do espaço. A pesquisa compreendeu as seguintes etapas: delimitação de unidades geoambientais; caracterização e mapeamento dos depósitos tecnogênicos presentes nas planícies e canais fluviais da bacia, destacando-se a dinâmica de formação e evolução dos depósitos, a influência da ação humana nesse processo e sua relação com os depósitos naturais; e a integração dos dados obtidos, evidenciando-se as principais alterações da bacia. A análise integrada do meio físico, biótico e do uso e ocupação do solo resultaram na delimitação de nove unidades geoambientais. A análise dos depósitos tecnogênicos implicou na determinação de cinco tipos de depósitos, classificados em construídos e induzidos. A avaliação da bacia indica os altos índices de impacto do meio ambiente decorrentes do processo de produção do espaço. A metodologia adotada se mostrou eficaz no estudo das alterações da bacia do ribeirão Anicuns e permitiu a compreensão da relação entre o homem e o meio / Abstract: This work consists in the study and evaluation of environment changes arising from the presence of technogenic deposits in the Anicuns river basin, in southwestern of Goiania city, Goiás. Technogenic deposits are witness of human geological action and reveal's features of the natural environment transformation through various forms of space appropriation. The research included the following steps: definition of geoenvironmental units, characterization and mapping of the technogenic deposits placed in floodplains and river channels, highlighting the formation dynamics and evolution of the deposits, the influence of human action in this process and its relationship with the natural deposits; the integration of data, evidencing the main changes of the basin. The integrated analysis of the physical, biotic and land use and occupation resulted in the delineation of nine environmental units. The analysis of technogenic deposits resulted in the determination of five types of deposits, classified as constructed and induced. The basin assessment indicates high levels of environmental impact resulting from the process of space production. The methodology was effective in the study of changes in the Anicuns basin and allowed the understanding of the relationship between man and environment / Mestre
193

A critical evaluation of the concept of sustainable development as applied in the legislation governing environmental impact assessments in South Africa (case studies: housing developments)

Osborne, Bernadette Nadine January 2015 (has links)
Dissertation submitted in partial fulfilment of the requirements for the degree Master of Technology: Environmental Management in the Faculty of Applied Science at the Cape Peninsula University of Technology / The concept “Sustainable Development” (SD) is defined and interpreted differently worldwide with the result that it encompasses different meanings to different people. The environmental impact assessment (EIA) process has been identified as a key tool for the implementation of SD. This research focuses on the concept of SD and its interpretation, meaning and implementation in terms of the legislation governing EIAs in South Africa. The research methodology employed in the thesis involves a literature study of the historical development and emergence of the concept of SD and the legal framework in which it is contextualised in South Africa. This is followed by a critical evaluation of the concept and its implementation using Jacob’s six Fault Lines. These Fault Lines include (i) the degree of environmental protection that is envisaged to attain SD, (ii) the emphasis placed on equality as a prerequisite for SD, (iii) the measure of participation required to attain SD, (iv) the scope of the concept of SD, (v) the environmental monitoring and evaluation that is required for SD as well as (vi) environmental planning to achieve the goal of SD. The second half of the thesis employs a case study methodology to evaluate the implementation of SD in five separate housing EIA processes in the Stellenbosch Municipal Area. Personal interviews and site observations are used to inform the case studies. The study identifies major conceptual flaws associated with the interpretation and implementation of the concept of SD as well as the challenges preventing EIAs from being an effective tool to enhance SD.The main findings are that EIAs do not sufficiently take into account the cumulative impacts of developments, they are unable to protect the environment from the increasing demand for additional housing in South Africa and that there is insufficient monitoring of EIA processes to ensure adequate long-term environmental protection.
194

Economic evaluation of environmental impacts of industrial products

Manmek, Suphunnika, Mechanical & Manufacturing Engineering, Faculty of Engineering, UNSW January 2007 (has links)
Environmental costs of products are closely related to their environmental impacts incurred at all life cycle stages of a product. Life Cycle Assessment (LCA) and Life Cycle Costing (LCC) methods are often used to estimate these environmental costs and impacts. However, LCA analysis is known to be a costly and time-consuming method, whereas LCC analysis often neglects the social cost which is currently paid by society as a whole. Therefore, this research proposes a new methodology to assess the environmental impact and social cost for the entire life cycle of a product, which can be used as a simple and transparent tool for the early conceptual design stage. The methodology delivers the Environmental Impact Drivers and the associated Social Cost Drivers for all product life cycle stages via spreadsheets, and it provides the Life Cycle Impact Assessment (LCIA) method in the SimaPro software as a user interface. Furthermore, the drivers provide the values for four different geographical regions and damage categories. The conceptual model is based on the impact pathway approach which integrates the Simplified LCA (SLCA) model and the social cost databases. The SLCA model is derived from an extension of previous research whereas the social costs are based on the most suitable Economic Valuation (EV) studies such as the EPS2000d, EXMOD, Ecosense and Asian EV studies. The data collection for the SLCA database was accomplished by using the LCA analysis of the Eco Indicator 99 H/A method and the Hierarchical clustering technique. The data for the social cost database was collected using the Benefit Transfer Method which obtains the EV studies mainly from the Environmental Valuation Reference Inventory (EVRI) data source. Several case studies utilising existing products, including a product redesign case study were used to prove the concept and demonstrate the efficiency of this proposed methodology.
195

Are cultural impact assessments a tool for collaborative management?

Vanstone, Anita Mary, n/a January 2003 (has links)
This thesis investigates the participation of Maori (New Zealand�s indigenous people) in the impact assessment process. Traditionally, Maori have had limited involvement in the management of New Zealand�s environment. One possible solution to this could be through the adoption of a collaborative management framework. Unfortunately, there is limited information and research on tools that could facilitate collaborative management between iwi and applicants for resource consent (including, developers, planning consultants and local authorities). Therefore, this research attempts to fill in a gap in current literature and to investigate the potential of the cultural impact assessment as a tool for collaborative management. Despite some criticisms of collaborative management, there are examples where this form of communicative planning has resulted in a very positive outcome for indigenous groups. Therefore, the specific aim of this research is to analyse the extent to which cultural impact assessments can be used as a tool to promote collaborative management between iwi and applicants. In achieving the research objectives of the thesis, the theoretical background of collaborative management and impact assessment theories are explored. In addition, democracy and participation theories are also investigated. In particular, in the discussion of these theories emphasis is placed on the potential involvement of indigenous peoples. The thesis argues that the application of collaborative management via the use of cultural impact assessments may potentially increase Maori involvement in planning. Analysis of collaborative management and impact assessment theories is supported by empirical research. This includes; 1) an exploration of the New Zealand setting for the two theories, 2) a content analysis of cultural impact assessments from eight different iwi authority in New Zealand, and 3) a case study analysis of two iwi organizations that have an established system for undertaking cultural impact assessments (Kai Tahu ki Otago and the Wellington Tenths Trust). The research finds that cultural impact assessments are very similar to other impact assessment reports. However, they should be viewed as evolving documents, as there are some areas of the assessment process that need to be improved upon. The research concludes by suggesting that cultural impact assessments do have the potential to be a tool for collaborative management between iwi and applicants. Further research and education in relation to the content, value and process of cultural impact assessments is required. It is also argued that increased resourcing, training and legislative requirements are needed to further increase Maori participation in planning.
196

The role of the environmental impact statement under the South Australian Planning Act from 1982 - 1993

Harvey, Nicholas January 1993 (has links)
After more than a decade of environmental impact assessment ( EIA ) provisions within South Australian Planning Act, 1982 it is appropriate to examine the role of the environmental impact statement ( EIS ) as a major element of EIA and an important decision making tool for major projects over this period. The thesis first provides a review of EIA from its overseas origins to its development at the Commonwealth level in Australia. This provides the context within which to examine the system of EIA for major developments or projects in South Australia, which are dealt with largely through the EIS process. The thesis examines the type of projects which, according to the discretionary criteria in the Planning Act, have attracted EIS requirements between 1982 - 1993 and uses this to determine generic groupings of projects. It is noted that marinas represent the largest group of projects with EIS requirements, although EISs have been called for power generation related projects, electricity transmission line projects, tourist related projects, industrial projects, mining projects, water management projects, transport projects and a number of other projects. The thesis examines the number of EISs that have been completed, whether or not the projects have been approved or rejected and to what extent any patterns have emerged. The thesis then focuses on all the completed EISs in terms of their content, timing of preparation, public involvement and response, associated legislative requirements, type and role of developer, type and role of EIS consultant, the assessment of the EIS, and the decision making process. The thesis notes the high approval rate for projects with completed EISs suggesting most of the environmental problems have been resolved or are capable of being resolved. It is also noted that a number of projects are abandoned before the EIS is ever completed and that the few rejected EIS proposals are associated with high numbers of public submissions. Although each of the rejected proposals has a complex history of project development, environmental assessment and negotiations, it is noted that the decision to reject the proposals was ultimately a political decision. The thesis comments on the limited role of the South Australian Planning Commission ( SAPC ) in EIS project decision making in South Australia and the increasing use of the Governor as a decision maker. Although the SAPC is the statutory planning authority it is constrained by having to have regard to the principles in the Development Plan which is geared toward development control rather than for the extraordinary major projects which become subject to EIS requirements. The thesis then examines proposed changes to EIA in the context of early attempts to initiate EIA reform in South Australia through to the current Development Bill. These proposals are placed in context with changes to EIA procedures that have taken place at the Commonwealth level, the proposed development of a national agreement on EIA, and also the implications for EIA which are likely to flow from recent Commonwealth initiatives on ecologically sustainable development strategies. In addition the implications of recently developed environment protection agencies and associated legislation are examined at both the State and Commonwealth levels. Collectively these reviews and analyses provide the context of current thinking on EIA as it is likely to affect South Australian EIA processes in the future. Finally the thesis discusses the evolving role of the South Australian EIS in the context of its evolutionary process and the proposed legislative changes in South Australia, together with other related initiatives. This discussion touches on a number of issues such as public administration, the actual practice of the EIA process as opposed to the theory of EIA and what is written into the EIA legislation. In conclusion an overview is given of the current role of the EIS with some predictions for the future of EIA in South Australia. / Thesis (M.Plan.)--Department of Architecture, 1993.
197

The effect of compact development on travel behavior, energy consumption and GHG emissions in Phoenix metropolitan area

Zhang, Wenwen 10 April 2013 (has links)
Suburban growth in the U.S. urban regions has been defined by large subdivisions of single-family detached units. This growth is made possible by the mobility supported by automobiles and an extensive highway network. These dispersed and highly automobile-dependent developments have generated a large body of work examining the socioeconomic and environmental impacts of suburban growth on cities. The particular debate that this study addresses is whether suburban residents are more energy intensive in their travel behavior than central city residents. If indeed suburban residents have needs that are not satisfied by the amenities around them, they may be traveling farther to access such services. However, if suburbs are becoming like cities with a wide range of services and amenities, travel might be contained and no different from the travel behavior of residents in central areas. This paper will compare the effects of long term suburban growth on travel behavior, energy consumption, and GHG emissions through a case study of neighborhoods in central Phoenix and the city of Gilbert, both in the Phoenix metropolitan region. Motorized travel patterns in these study areas will be generated using 2001 and 2009 National Household Travel Survey (NHTS) data by developing a four-step transportation demand model in TransCAD. Energy consumption and GHG emissions, including both Carbon Dioxide (CO₂) and Nitrous Oxide (N₂O) for each study area will be estimated based on the corresponding trip distribution results. The final normalized outcomes will not only be compared spatially between Phoenix and Gilbert within the same year, but also temporally between years 2001 and 2009 to determine how the differential land use changes in those places influenced travel. The results from this study reveal that suburban growth does have an impact on people's travel behaviors. As suburbs grew and diversified, the difference in travel behavior between people living in suburban and urban areas became smaller. In the case of shopping trips the average length of trips for suburban residents in 2009 was slightly shorter than that for central city residents. This convergence was substantially due to the faster growth in trip lengths for central city compared to suburban residents in the 8-year period. However, suburban residents continue to be more energy intensive in their travel behavior, as the effect of reduction in trip length is likely to be offset by the more intensive growth in trip frequency. Additionally, overall energy consumption has grown significantly in both study areas over the period of study.
198

Essays on sustainable operations

Agrawal, Vishal 15 June 2010 (has links)
With the increased attention of different stakeholders on the environmental performance of businesses, several firms are increasingly focusing on product recovery and reuse activities which are not only profitable but may also help to reduce the environmental impact of their operations. This dissertation focuses on managerial challenges associated with such value-added recovery and reuse activities. The first essay examines how a firm should bring a product to market, in particular, whether to lease or sell products. Motivated by claims that leasing can be an environmentally superior to selling, we analytically investigate if either leasing or selling can be both more profitable for a monopolist and have a lower total environmental impact. The second essay first experimentally examines the effect of remanufactured products on the perceived value of new products. This effect is then incorporated to analytically investigate an OEM's strategy in the presence of competition from third-party remanufacturers. In the third essay, motivated by a major IT company, we investigate the optimal product recovery and remanufacturing strategy for a firm that can offer trade-in rebates to achieve price discrimination. We also consider the effect of potential entry of third-party remanufacturers on the firm's recovery and remanufacturing strategy.
199

A methodology to enable rapid evaluation of aviation environmental metrics and aircraft technologies

Becker, Keith Frederick 16 May 2011 (has links)
Commercial aviation has become an integral part of modern society and enables unprecedented global connectivity by increasing rapid business, cultural, and personal connectivity. In the decades following World War II, passenger travel through commercial aviation quickly grew at a rate of roughly 8% per year globally. The FAA's most recent Terminal Area Forecast predicts growth to continue at a rate of 2.5% domestically, and the market outlooks produced by Airbus and Boeing generally predict growth to continue at a rate of 5% per year globally over the next several decades, which translates into a need for up to 30,000 new aircraft produced by 2025. With such large numbers of new aircraft potentially entering service, any negative consequences of commercial aviation must undergo examination and mitigation by governing bodies so that growth may still be achieved. Options to simultaneously grow while reducing environmental impact include evolution of the commercial fleet through changes in operations, aircraft mix, and technology adoption. Methods to rapidly evaluate fleet environmental metrics are needed to enable decision makers to quickly compare the impact of different scenarios and weigh the impact of multiple policy options. As the fleet evolves, interdependencies may emerge in the form of tradeoffs between improvements in different environmental metrics as new technologies are brought into service. In order to include the impacts of these interdependencies on fleet evolution, physics-based modeling is required at the appropriate level of fidelity. Evaluation of environmental metrics in a physics-based manner can be done at the individual aircraft level, but will then not capture aggregate fleet metrics. Contrastingly, evaluation of environmental metrics at the fleet level is already being done for aircraft in the commercial fleet, but current tools and approaches require enhancement because they currently capture technology implementation through post-processing, which does not capture physical interdependencies that may arise at the aircraft-level. The goal of the work that has been conducted here was the development of a methodology to develop surrogate fleet approaches that leverage the capability of physics-based aircraft models and the development of connectivity to fleet-level analysis tools to enable rapid evaluation of fuel burn and emissions metrics. Instead of requiring development of an individual physics-based model for each vehicle in the fleet, the surrogate fleet approaches seek to reduce the number of such models needed while still accurately capturing performance of the fleet. By reducing the number of models, both development time and execution time to generate fleet-level results may also be reduced. The initial steps leading to surrogate fleet formulation were a characterization of the commercial fleet into groups based on capability followed by the selection of a reference vehicle model and a reference set of operations for each group. Next, three potential surrogate fleet approaches were formulated. These approaches include the parametric correction factor approach, in which the results of a reference vehicle model are corrected to match the aggregate results of each group; the average replacement approach, in which a new vehicle model is developed to generate aggregate results of each group, and the best-in-class replacement approach, in which results for a reference vehicle are simply substituted for the entire group. Once candidate surrogate fleet approaches were developed, they were each applied to and evaluated over the set of reference operations. Then each approach was evaluated for their ability to model variations in operations. Finally, the ability of each surrogate fleet approach to capture implementation of different technology suites along with corresponding interdependencies between fuel burn and emissions was evaluated using the concept of a virtual fleet to simulate the technology response of multiple aircraft families. The results of experimentation led to a down selection to the best approach to use to rapidly characterize the performance of the commercial fleet for accurately in the context of acceptability of current fleet evaluation methods. The parametric correction factor and average replacement approaches were shown to be successful in capturing reference fleet results as well as fleet performance with variations in operations. The best-in-class replacement approach was shown to be unacceptable as a model for the larger fleet in each of the scenarios tested. Finally, the average replacement approach was the only one that was successful in capturing the impact of technologies on a larger fleet. These results are meaningful because they show that it is possible to calculate the fuel burn and emissions of a larger fleet with a reduced number of physics-based models within acceptable bounds of accuracy. At the same time, the physics-based modeling also provides the ability to evaluate the impact of technologies on fleet-level fuel burn and emissions metrics. The value of such a capability is that multiple future fleet scenarios involving changes in both aircraft operations and technology levels may now be rapidly evaluated to inform and equip policy makers of the implications of impacts of changes on fleet-level metrics.
200

Exploring the linkage of Environmental Impact Assessment (EIA) and Geographic Information Systems (GIS) a case study of the West Run Expressway (WRE), Morgantown, Monongalia County, West Virginia /

Keleagetse, Sewelo S. January 2001 (has links)
Thesis (M.A.)--West Virginia University, 2001. / Title from document title page. Document formatted into pages; contains vii, 95 p. : ill., maps (some col.). Includes abstract. Includes bibliographical references (p. 93-95).

Page generated in 0.1016 seconds