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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.
261

Removal of Sulfur Dioxide and Nitric Oxide From a Flue Gas Stream By Two Sodium Alkalis of Various Sizes

Carson, John R. 01 August 1980 (has links)
The primary purpose of this research effort was to examine the dry removal of SO2 and NO from a flue gas stream by injecting two sodium additives into a pilot bag house system. The additives tested were NaHCO3 and Na2CO3 dusts with mass mean diameters ranging from approximately 30 to 200 microns. The Na2CO3 was obtained by decomposing the NaHCO3 (with heat) prior to testing. The bag house temperature was maintained at either 250 or 300 degrees F. It was demonstrated that 70% SO2 removal can be attained with NaHCO3 powders that have mass mean diameters of 32 and 52 microns at stoichiometric ratios of 0.8 and 1.3, respectively. The rate of mass transfer limited the desulfurization capacity of NaHCO3 powders with mass mean diameters greater than 50 microns. The rate of chemical reaction limited the SO2 removal capability of the smallest NaHCO3 additive tested (mass mean diameter = 32 microns). Decomposition of NaHCO3 to Na2CO3 in bulk before injection yielded poorer SO2 removal. It was also demonstrated that 7 to 36% of the NO was removed simultaneously with SO2 by the NaHCO3 additives with mass mean diameters smaller than 120 microns. This removal was inversely dependent on the system temperature. No appreciable NO removal was observed with Na2CO3 injection.
262

Elemental Analysis of Soils Using Laser-Induced Breakdown Spectroscopy (LIBS)

Yang, Ningfang 01 August 2009 (has links)
Laser-induced breakdown spectroscopy (LIBS) has been applied for the quantitative analysis of various samples, but it is controversial for chemically-complex soils. In order to study the effect of delay time, gate width, and repetition rate on the LIBS signal in soil, the emission line at 396.84 nanometer was selected. The results indicated that repetition rate, delay time, and gate width significantly affected the LIBS signal, delay time was more important than gate width in controlling the LIBS signal. The optimum instrumental parameters for soil analysis were obtained when repetition rate, delay time, and gate width equaled 10 hertz, 1 microsecond, and 10 microsecond, respectively. In order to compare the analytical ability of univariate and multivariate approaches in analyzing the LIBS spectral data and to quantitatively determine copper and zinc concentrations in soils, 12 samples with different copper and zinc concentrations were analyzed by inductively coupled plasma optical emission spectroscopy (ICP-OES) and LIBS, respectively. The univariate and the partial least square (PLS) regression were coupled with LIBS to build the calibration models and to predict copper and zinc concentrations. The background-subtracted signal intensity at 324.75 nanometer (copper) and 334.59 nanometer (zinc) were used for the univariate analysis, and the full spectral range 200-600 nanometer and the reduced spectral ranges 250-450 nanometer and 300-350 nanometer were used for the PLS analysis. Copper and zinc concentrations predicted by LIBS were compared with those measured by ICP-OES. The results demonstrated that (1) the PLS regression was powerful in analyzing the LIBS spectral data, and compared to the univariate regression, it improved the normalized root mean square error of calibration (NRMSEC) about 15% and the normalized root mean square error of prediction (NRMSEP) about 10% respectively; (2) The PLS regression using the reduced spectral range (300-350 nanometer) containing copper and zinc peaks produced the best results among all the spectral ranges, which indicated that use of the suitable spectral range in the PLS regression improved the LIBS analytical ability; (3) The implementation of multivariate approaches in analyzing the LIBS spectral data made the quantitative analytical ability of LIBS promising and comparable to that of ICP-OES.
263

Utfasning av farliga kemikalier - Vid Banverket och Vägverket

Nyholm, Sofia January 2009 (has links)
Large quantities of chemicals are used in all areas of society. The chemicals can be toxic and dangerous for the environment if used incorrectly. To protect people and the environment from dangerous chemicals, a good control of them and an active work to phase out hazardous substances in all areas where chemicals are present, are needed. Banverket and Vägverket handle in production a wide range of chemical products. Many of the products are dangerous to the environment, for those who work with them and to others who may come into contact with them. Since January 2005 Banverket and Vägverket cooperates in the chemical field, using a common chemical database and common requirements and criteria for the assessment of chemical products. In this work, I have conducted an inventory of hazardous substances used within Banverket and Vägverket and I have also tried to identify the drivers and barriers that are linked to work with the phasing out of hazardous chemicals and to apply the law product choice principle. One of Sweden's environmental objectives is Non-Toxic Environment, which has an intermediate target, which reads, "Phasing out of hazardous substances." Working actively with the phase-out reduces the risks of hazardous chemicals coming out into the environment and contributes to reaching the desired environmental goal in time. Higher demand from authorities and legislative changes may intensify work with chemicals and the phasing out. However, the driving force for wanting to reduce the number of hazardous chemicals found in an activity must be there if the phasing out process will be successful and a general responsibility must be taken in order to achieve the environmental objective. I have found that the phasing out of chemicals is very complex and requires hard work to tbe successful. Banverket and Vägverket are on track and have good practices in their work but there is more to do. Making use of the driving forces that exist and the smooth way to pass obstacles in the way you will get a very successful work with the phasing out of chemicals and application of the product choice principle. I hope that the outcome of the thesis will stimulate a more active work with the phasing out of chemicals, which also contributes to achieving the environmental objective A Non-Toxic Environment.
264

Have the automobile companies; Honda and Renault achieved to deliver their environmental message to their customers?

Ometlic, Tanja, Smith, Caroline, Svajda, Adela January 2009 (has links)
Environment friendly, so called green marketing has become a discussed subject and companies are constantly trying to find the best ways to reach the customers with their green message. A trademark is considered to be able to work as a source of information and risk reducer for customers, which can be a step towards green communication. Customers are becoming more demanding and they have started to pay more attention to the environment. What is important with trademarks is how customers perceive them, what the image of the trademark is. The aim of this study is to find out and compare how two multinational car manufacturers, Honda and Renault, have used their strategic trademark in order to create a “green” image. By green image meaning so called goods that are being perceived as environmental friendly by the customers. The research study took place in Worcester and Birmingham in England, during the spring 2009. A questionnaire was designed in order to find out how people perceive these two trademarks and how aware they are of the “environmental contribution” that is being made by these companies. The question we wanted to find a respond to where “Have the automobile companies Honda and Renault achieved to deliver their environmental message to their customers?” The results from this illustrates that both companies need to increase their communication with the customers, and that attributes like price and quality are more important than “environmental responsibility”. This study is based on only Honda and Renault and has not taken the rest of the automobile industry into consideration.
265

Re-imagining the Public Trust Doctrine to Conserve U.S. Ocean Ecosystems

Turnipseed, Mary P. January 2011 (has links)
<p>Sustainably managing marine ecosystems has proved extremely difficult, with few success stories. Traditional approaches to managing ocean-borne activities, including the structure of the governance systems themselves, have had difficulty keeping pace with the dynamics of coupled human, ecological, and oceanographic systems. In essence, our governance systems for ocean resources and environments have had difficulty keeping pace with advances in ocean use and exploitation technologies.</p><p>In the United States today there are over twenty federal agencies and thirty-five coastal states and territories operating under hundreds of statutory authorities shaping coastal and ocean policy. For years, among marine ecologists and policy experts there has been consensus that a major overhaul in U.S. ocean governance is necessary. This dissertation broadly suggests the public trust doctrine--an ancient legal concept that is already incorporated in U.S. state coastal laws--could uniquely provide a critical legal foundation for a new era in U.S. federal ocean governance.</p><p>Though the public trust concept can be located in the legal systems of many countries, it robustly manifests in the United States, where it has historically protected the public's rights to fishing, navigation, and commerce in and over navigable waterways and tidal waters. In its most basic form, the doctrine obliges governments to manage common natural resources, the body of the trust, in the best interest of their citizens, the beneficiaries of the trust. Today the public trust doctrine is integral to the protection of coastal ecosystems and beach access in many states and has even made its way into state constitutions. It would be simple, and seemingly logical, to assume that the same fiduciary responsibility of states to protect public trust uses of their waters extends to all marine resources within the United States' 200-mile Exclusive Economic Zone (EEZ). However an artificial line has been drawn around state waters, and the legal authority and responsibility of the U.S. government to protect public trust resources in the vast space of its EEZ (the largest of any country on earth) have never been fully and expressly established. The second chapter in this dissertation outlines the development of states' public trust doctrines; discusses the expansion of U.S. sovereignty over its neighboring ocean waters during the twentieth century; analyzes possible avenues for expanding the doctrine to federal waters; and considers how a federal public trust doctrine could clarify some specific issues in U.S. oceans management. At the heart of this chapter's analysis lie three questions: (1) does a federal public trust doctrine exist; (2) if so, can it be rightfully extended to include the entirety of the U.S. ocean waters; and (3) could the doctrine provide the missing catalyst for federal agencies to manage the use of U.S. ocean resources in a coordinated, sustainable fashion? </p><p>The third chapter asks how the public trust doctrine could inform marine spatial planning in US waters. It argues that in the absence of a statutory mandate for agencies to collaborate in their management of ocean-borne activities, the public trust doctrine could provide a framework for restructuring the way the US federal government regulates ocean uses. The forth chapter examines the blowout of the Deepwater Horizon oil rig on April 20, 2010, and surmises that regulatory capture of the Minerals Management Service aided by a balkanized ocean governance regime in the pre-Deepwater Horizon era provided a potent source of systemic risk in the U.S. offshore oil and gas industry. It discusses the factors contributing to MMS' susceptibility to capture in the pre-Deepwater Horizon era, as well as examples of decisions it made that suggest dynamics of regulatory capture were at play. The chapter then explores the reform of offshore oil and gas regulation under BOERME and the National Ocean Council to understand the how these new governmental structures might be less susceptible to capture. Lastly, the chapter considers the added value of extending two alternative versions of a clear federal public trust mandate - a foundational US natural resources doctrine - to offshore oil and gas regulation and, more generally, to coastal and marine spatial planning under the National Ocean Council. </p><p>The final substantive chapter of this dissertation concerns the US Interagency Ocean Policy Task Force and reports the results of a case study analysis that I conducted to explore how and why the Task Force designed the National Ocean Policy and interagency governance structure, the National Ocean Council, like it did. I found that the recommendations of the Task Force drew heavily from previous studies of US federal ocean policy and the Committee on Ocean Policy, which lasted from 2004-2009. Additionally I sought to understand the Task Force within the context of other US interagency collaborative efforts and theories concerning collaborative governance. I found that the Task Force process was characterized by several characteristics that policy scholars have previously identified as important to promoting collaboration among agencies. I also found support for the theoretical proposition that often external and political factors have major impacts on the level of success attained by interagency efforts. Lastly, via interviews with Task Force staffers and content analysis of public comments submitted to the Task Force, I determined that - though not included in the National Ocean Policy - there remains interest in the principles of the public trust doctrine as underpinning for the policy, which seeks "[t]o achieve an America whose stewardship ensures that the ocean, our coasts, and the Great Lakes are healthy and resilient, safe and productive, and understood and treasured so as to promote the well-being, prosperity, and security of present and future generations."</p> / Dissertation
266

An Analysis of the Prevalence of the West Nile Virus in Relation to Health Resilience along the Gulf of Mexico

Mata, Lillian Patricia 11 May 2013 (has links)
As the Earths climate changes, coastal communities are increasingly vulnerable to the natural hazards that are driven by these processes, particularly in regards to the health of these communities. It has been shown that disease patterns can change in response to our environment, putting the health resilience of communities at risk. This study looks at the relationship between natural exposure and traditional resilience index variables in the context of the spread of West Nile Virus along the Gulf of Mexico. Through analysis of 534 counties, the West Nile Virus for 2001-2012 was analyzed as an incidence and incidence rate at three levels of urban and rural classification (metropolitan, micropolitan, and rural) as well as for the entire study area. Regression analysis found that models incorporating both natural and society indicators were more successful at explaining a populations vulnerability to the West Nile Virus. It was seen that short-term climate variability and economic indicators were important measures of a communitys health resilience in the context of the prevalence of the West Nile Virus. Socio-economic characteristics proved to be more explanatory in rural environments while natural characteristics explained more variance in metropolitan and micropolitan environments. Increasing temperatures were found to increase the spread of the West Nile Virus, particularly in urban areas. This study is a tangible analysis of health resilience in the context of both the human and natural environments across different levels of human infrastructure on a large spatial scale.
267

Impacts and Recovery of the Deepwater Horizon Oil Spill on Vegetation Structure and Function of Phragmites Australis

Judy, Chad Robert 20 June 2013 (has links)
Abstract The aim of this study was to determine the impacts of the Deepwater Horizon (DWH) oil spill on the common reed Phragmites australis, and the processes controlling species effects and recovery, via a greenhouse mesocosm study. In the greenhouse DWH source oil, weathered approximately 40% by weight and emulsified, was applied to the aboveground shoots of P. australis growing in marsh sods to produce the following treatment-levels: (1) oil coverage of the lower 30% of shoot-height, (2) the lower 70% of shoot-height, (3) repeated oil coverage of the lower 70% of shoot-height, (4) 100% oil coverage of shoots, (5) oil applied to the soil at a rate of 8 L m⁻², and (6) unoiled controls. I quantified a strong resilience of P. australis when oil was applied only to aboveground biomass, with negative impacts becoming apparent when oil was added to the soil profile. The Total biomass and stem cumulative length were both impacted by the addition of 8 L m⁻² of weathered DWH source oil to the soil profile. Due to the apparent negative results of adding oil directly to the soil, a second experiment was designed to better understand impacts from soil oiling. Aboveground biomass was harvested from the sods that had received only shoot oiling and allowed to regrow for two months, at which point weathered DWH source oil was applied to the marsh sods at rates of (1) 0 L m⁻² (control), (2) 4 L m⁻², (3) 8 L m⁻², (4) 12 L m⁻², and (5) 16 L m⁻². This experiment verified that increased oiling to the soil profile increased negative impacts to P. australis, reducing stem cumulative length, aboveground biomass, and belowground biomass at the highest oiling rates. Higher oiling doses resulted in higher rates of soil respiration and reduced soil Eh. Based on my research, complete mortality of P. australis is unlikely from exposure to weathered and emulsified DWH source oil. However, vertical growth, above and belowground biomass, and other plant processes will be impacted, with oiling to the soil having much greater impact than oiling to the aboveground shoots.
268

Reform of environmental laws in Botswana: the need for an environmental framework act

Koboto, Oduetse January 2010 (has links)
No description available.
269

Leadership in Environmental and Energy Design: A True Sustainable Development Model?

Loser, Christopher Jay 10 April 2013 (has links)
Suburban sprawl and sustainable development has received increasing worldwide attention over the past few decades. In 1998, sustainable development principles were codified in the Leadership in Energy and Environmental Design (LEED) certification system. The most recent LEED certification system to be released, LEED for New Development (LEED-ND), includes sustainable development goals with the addition of smart growth principles intended to curb sprawl. This study examines and evaluates LEED-ND in order to determine if it meets the requirements of sustainable development to provide for the needs of future generations, as defined by the United Nations World Commission on Environment and Development. It also analyzes certified LEED-ND projects to determine which portions of the rating system were utilized the most, and least, frequently, and provided recommendations for future LEED-ND revisions. The study found that, while LEED-ND does promote most long-term sustainable development goals, it focuses more upon climate change and social equity than it does in combating sprawl and its environmental impacts. However, its inflexible and exclusory nature prevent many sustainable development goal from being fulfilled, and its use of double-counting credits exaggerates its sustainable development achievements.
270

ENVIRONMENTAL MICROPOLLUTANTS THE ROLE OF CONCENTRATION ON TREATABILITY, TECHNOLOGICAL TREATMENT OPTIONS, AND BUSINESS CONSIDERATIONS

Simpson, Francis Joseph 15 April 2013 (has links)
Pharmaceuticals and Personal Care Products (PCPPs) are an emerging class of water pollutants, which have the potential for human health and adverse environmental impacts. This thesis will seek to answer key questions related to biological treatment, adsorption processes, the viability of advanced treatment processes, and business considerations to remove PCPPs from water. The hypotheses are: How does the concentration of these micropollutants affect their ability to be treated? How are carbon adsorption and biological treatment affected by competition of other substrates? To what extent will current technology allow for their safe removal from discharge sources? Addressing these questions will be accomplished with Monte Carlo simulations and kinetics modeling. To successfully remove these micropollutants, biological, chemical adsorption, and other novel treatment methods were explored to ascertain if these methods could be utilized to remove these substance from water and wastewater. It was found that currently available treatment methods (biological and chemical adsorption) are highly dependent upon the competitive effects that occur as a result of the other constituents within wastewater. Therefore, advances processes like wet-air oxidation, Reverse Osmosis, and Plasma Arc Waste Disposal must be considered to adequately remove these compounds.

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