• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 11
  • 1
  • Tagged with
  • 15
  • 15
  • 5
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 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

Exhaustible resources : Theory extension and application

Al-Jasim, M. S. January 1987 (has links)
No description available.
2

Analysing controversies in energy policy : assessing the evidence for rebound effects and global oil depletion

Sorrell, Steve January 2012 (has links)
This thesis is submitted as a PhD by Publication. Part A provides an overview of the thesis and summarises its context, research questions, methodological approach and key findings. Part B is a collection of nine, first-named academic papers. The thesis addresses two highly complex and controversial questions within energy policy, namely the nature and magnitude of ‘rebound effects’ from energy efficiency improvements and the extent and rate of depletion of global oil resources. Both of these questions are critically important to the development of a sustainable energy system and both are the subject of long-standing and highly polarised disputes. The thesis adapts, develops and applies a common methodology for reviewing the evidence on these questions, supplements this with original primary research and syntheses the results in a way that improves understanding and provides new insights. The thesis includes four papers examining different aspects of rebound effects and four examining different aspects of global oil depletion. Given the complexity of the chosen topics, the papers cover a wide range of questions, issues and approaches. Collectively the papers: clarify relevant definitional and conceptual issues; evaluate competing methodological and analytical techniques; appraise the methodological quality of empirical studies; identify levels of uncertainty and potential sources of bias; develop simple mathematical models; conduct statistical analyses of primary data; compare and evaluate the results of modelling studies; and synthesise results from multiple research areas to provide novel insights into poorly understood phenomena. A ninth paper evaluates the strengths and limitations of systematic review techniques when applied to complex, policy-relevant questions such as these. The thesis draws two main conclusions. First, rebound effects are frequently large and can substantially reduce the energy and carbon savings achieved from improved energy efficiency. Second, there is a significant risk that the global production of conventional oil will enter sustained decline before 2020. These conclusions run counter to conventional wisdom and have significant implications for public policy. The thesis also shows how the methodology of systematic reviews can be adapted and modified to make a valuable contribution to energy and climate policy research.
3

Social, Personal, and Environmental Influences on Self-Control

vanDellen, Michelle 21 April 2008 (has links)
Current accounts of self-control are highly individualistic. When individuals succeed at exerting self-control, we assume that they possess some positive internal characteristic that explans their success. Similarly, when individuals do not succeed, we blame their failure on an internal flaw. Yet many factors may influence the likelihood that an individual will exert self-control, including not only internal characteristics of individuals but also external factors. In this dissertation, I develop a framework for understanding the multiple sources of influence on individuals' state self-control that groups these factors into three categories: social, personal, and environmental. Further, I detail the multiple mechanisms by which the factors in the Social, Personal, and Environmental Control of Self (SPECS) model may influence self-control. Specifically, I examine the potential role of regulatory accessibility as a mechanism of influence on state self-control. In Study 1, I show that individuals who think about a friend with good self-control demonstrate increased performance on a persistence task than do participants who think about a friend with bad self-control. In Study 2, I replicate this effect, showing increased inhibitory capacity among individuals who wrote about a friend with good self-control compared to a control group, and decreased inhibitory capacity among individuals who wrote about a friend with bad self-control. In Study 3, I show that regulatory exertion increases among individuals subliminally primed with the name of a friend with good self-control and that regulatory exertion decreases among indivdiuals primed with the name of a friend with bad self-control. These findings support my hypothesis that models of self-control should account for sources of influence external to the individual, as well as explore the multiple pathways by which regulatory exertion is influenced. These findings support my hypothesis that social factors influence regulatory exertion, or state self-control. Further, they provide evidence that state self-control is influenced not only by regulatory capacity, but also by other mechanisms, including regulatory accessibility. Further research following the SPECS model will investigate the combined influence of social and environmental influences on self-control and the indirect influences of personal characteristics, such as trait self-control, on regulatory exertion. / Dissertation
4

Dominance/Suppression Competitive Relationships in Loblolly Pine (Pinus taeda L.) Plantations

Dyer, Michael E. 20 November 1997 (has links)
Data from three long-term field studies with loblolly pine (Pinus taeda L.) plantations were used to examine inequality (Gini coefficient) trends in diameter and the relationship between diameter relative growth rate (r) and initial size. Analysis with two spacing studies shows inequality increases with increasing density. For a given initial density, inequality initially decreases and then begins to increase as trees compete for resources. The slope of the linear relationship between r and relative size also increases with increasing density. The slope is initially negative and switches to positive as competition intensifies. The switch in the slope of the r/size relationship occurs when the crown projection area exceeds 1.05 or when the crown ratio falls below 0.75. These results are consistent with the resource pre-emptive or dominance/suppression theory of intra-specific competition. The r/size trends are not evident when calculations are based on class means as opposed to individual trees. The slope of the r/size relationship is a function of stand height, density, and to a lesser extent, site quality. Density reduction through mid-rotation thinning tends to decrease the slope coefficient. The r/size trends are used to develop a disaggregation model to distribute stand-level basal area growth over an initial tree list. This approach compares well with two other disaggregation models but tends to over predict growth on the largest trees. / Ph. D.
5

Integrating Sustainability in the Food Supply Chain : Two Measures to Reduce the Food Wastage in a Swedish Retail Store

Nilsson, Herman January 2013 (has links)
Due to the growing world population, the environmental impact from the food supply chain is currently increasing in a global perspective, essentially because the global food consumption is increasing in general. The UN Food and Agriculture Organization (FAO) estimates that about one third of the edible portions of the food produced globally is lost or wasted along the way from raw materials to the dinner plate. When food is produced, transported, stored, treated and processed in different ways it consumes a lot of resources and energy and causes large negative impact on the environment due to emissions of pollutants affecting waters, soil and air. When food is wasted somewhere in the food supply chain, it implies unnecessary emissions of greenhouse gases and other pollutants and also entails a pointless extraction and use of natural resources: each since the production is made in vain. Sustainable development has been generally accepted as development that meets the needs of the present without compromising the ability of future generations to meet their own needs. Quite simple, this means that humanity of today needs to conserve the remaining resources on Earth and sharply reduce the anthropogenic environmental impact. In order to attain a state where man can live in equilibrium with the natural world,humanity must pursue sustainability in every activity and every movement. According to the Swedish Environmental Protection Agency (SEPA) a reduction of food loss within the food supply chain could facilitate society’s quest to develop in a sustainable manner. The retail store is one place where large numbers of food items are gathered at the same location and where a lot of food is discarded, many times completely in vain. It is thus a suitable place to take actions to reduce the foodloss in a quite effective way. In a Swedish retail store located in Uppsala, two product specific measures have been introduced; a new display table intended to reduce the loss bananas and a new price reduction routine intended to reduce the loss of grilled chicken. This thesis aims to investigate whether the measures put in place actually have resulted in reduced losses or not. The goal of the study was to examine how much unnecessary environmental impact (in terms of contribution to global warming) that hence has been avoided. The research questions are studied through a combination of data analyses, interviews and life-cycle assessments. SWOT analyses have also been conducted in order to evaluate the introduced measures in terms of contribution to sustainable development within the food sector. The results of the study concluded that the measure based on price reduction has reduced the losses of grilled chicken with approximately 200 kg per annum. This implies that an annual climate impact of around 430 kgCO2-equivalents has not been caused in vain, which should be the case if the 200 kg of chickens had instead been discarded. The study however shows that the measure is not particularly effective and could be improved in order to further reduce the daily losses. The data analysis show that the banana waste that arises during the exposure in the store has decreased with 1 200 kg per year, implying that around 1 400 CO2-equivalents has not been caused in vain. However, the study also shows that a rather complex system containing economic routines for handling food waste, most likely is wrongly used. Unfortunately, the routines may affect the registered waste outcome from the new display table due to a relocation of the waste from one waste category to another. The new display table’s effect on the total waste quantity is therefore difficult to evaluate. The conducted SWOT-analyses finally concluded that both introduced measures had strong environmental and economic benefits (and also favorable social benefits in the case of the display table), making them good and useful interdisciplinary solutions in terms of sustainability: thus contributing to a sustainable development within the food sector.
6

Rare Metals: Energy Security and Supply

Vikström, Hanna January 2011 (has links)
Lithium and neodymium are two critical materials in our modern society, many technological solutions depend on them. Lithium is used in batteries, which are used in cars and portable electronics. Neodymium, which is a rare earth element, is mainly used in permanent magnets which are used in smartphones, hard disc drives and turbines. There are many reports regarding the availability of the metals, with different results. The available data on the reserves varies considerably, from the few sources there are. In this report, based on geological availability, forecasts are done to investigate how much the production can increase and when it will peak. The prognoses are based on historic production to which different functions, the logistic, gompertz and richards, are fitted with the least square method. The production will peak in the end of this century and in the beginning of the next century for both metals. The production of lithium does not seem to be sufficient for both producing electric and hybrid cars with only li-ion batteries along with fusion. The neodymium production will be sufficient for producing a lower percentage of direct driven wind turbines and electric cars with NiMH batteries. Lithium in seawater is sometimes considered a future source. Since the lithium concentration is low, large volumes have to be processed in order to extract a reasonable amount of lithium. Currently it is not economic to extract lithium from seawater.
7

Government Decision-Making and Environmental Degradation: A Study relating to Mining Activities in Papua New Guinea

frcarr@bigpond.com, Frank Carr January 2007 (has links)
Papua New Guinea (PNG) is a country possessing abundant resources of gold, oil, copper, timber, and fish stocks. It is hampered in its development and management of these resources, however, by serious problems of governance and corruption. These problems are evident throughout the economy and also in the management of the environment. The level of environmental damage caused by the mining industry in PNG is now such that it will require extensive rehabilitation, if the areas affected can, indeed, ever be fully rehabilitated. The mining companies which precipitated this damage were licensed and encouraged by the PNG Government in the initiation and exercise of the mining operations. The resulting environmental impact has affected the lives of thousands of New Guineans to their detriment. The degradation caused remains unredressed. Compounding the problem, there is a growing reliance by Papua New Guinea on mineral exploitation for foreign direct investment, government revenues, and foreign exchange. Gold exports accounted for the biggest share of export revenues in 2002 representing 37.5% of the total. In light of this growing dependency on mining activities, there is a correspondingly urgent requirement to address the deficiencies in the administrative, monitoring, and policing aspects of the protection of its environment. Despite the public evidence of the damage to the environment and the ensuing affect on the people of Papua New Guinea by mining activities; and despite universal condemnation of these activities and the companies responsible; the companies continue to conduct these activities without official hindrance and with little apparent concern for the long-term ramifications of their actions. This thesis will examine the degradation resulting from the mining activities of companies in Papua New Guinea over the last three decades – particularly those of Placer Dome’s Porgera gold mine, BHP’s Ok Tedi gold and copper mine (the waste from both of which is dumped into the Ok Tedi and Strickland rivers which are tributaries of the Fly River and form part of the Fly River system) and Lihir Gold Limited's gold mine on Lihir Island. It will examine the extent to which the Government of Papua New Guinea may have wittingly (in the sense of a prescience as to the possible or probable likelihood of deleterious impact) or unwittingly contributed to that degradation as a result of its actions or omissions. Studies of available literature suggest that there has been little attention paid to the subject of culpability on the part of successive PNG governments in matters of environmental damage. This research will contribute to reducing this gap in the literature by focusing on possible motives of the PNG government and its actors which precipitated those decisions and which resulted in environmental degradation. The discussion will examine the likely motivation of the PNG government in its deliberations and decisions and the extent to which corruption and incompetence may have played a role.
8

Evaluation of Recyclability and Recycling Efficiency of Metals for Waste Printed Circuit Boards / 廃プリント基板からの金属の回収並びに回収効率の評価

Le, Hoang-Long 25 November 2013 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(エネルギー科学) / 甲第17966号 / エネ博第291号 / 新制||エネ||60(附属図書館) / 30796 / 京都大学大学院エネルギー科学研究科エネルギー社会・環境科学専攻 / (主査)教授 石原 慶一, 教授 東野 達, 教授 酒井 伸一 / 学位規則第4条第1項該当 / Doctor of Energy Science / Kyoto University / DFAM
9

INTERRACIAL INTERACTIONS AND RESOURCE DEPLETION

Johnson, Darian E. 02 December 2011 (has links)
No description available.
10

A Decision Support System For Electricity Generation Investment

Alpagut, Merih Ayse 01 June 2010 (has links) (PDF)
In the recent years, ongoing debates in the mineral sector has shown that efficient use of natural resources is of vital importance as the use of minerals is essential for modern living. Especially, in the context of sustainable development, it is required that mineral resources should be exploited to maximize the contribution to the well being of current generation without depriving the potential for future generations to meet their own needs. The aim of this thesis is to develop a decision support system using system dynamics methodology where

Page generated in 0.0994 seconds