• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 180
  • 84
  • 81
  • 48
  • 22
  • 14
  • 8
  • 7
  • 7
  • 7
  • 3
  • 3
  • 2
  • 2
  • 2
  • Tagged with
  • 553
  • 67
  • 61
  • 48
  • 47
  • 38
  • 36
  • 32
  • 32
  • 31
  • 30
  • 29
  • 27
  • 26
  • 26
  • 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.
221

Polarimetric SAR decomposition of temperate Ice Cap Hofsjokull, central Iceland

Minchew, Brent Morton 17 December 2010 (has links)
Fully-polarimetric UAVSAR data of Hofsjokull Ice Cap, central Iceland, taken in June 2009 was decomposed using Pauli-based coherent decomposition as well as Cloude and H/A/alpha eigenvector-based decomposition methods. The goals of this research were to evaluate the effect of the near-surface conditions of temperate glaciers on polarized SAR data and investigate the potential of creating a model of the radar scattering mechanisms based on the decomposed elements and local temperature. The results of this data analysis show a strong relationship between the Pauli and H/A/alpha decomposition elements and the near-surface conditions. Fitting curves to the normalized Pauli decomposition elements shows consistent trends across several spatially independent regions of the ice cap suggesting that the Pauli elements might be useful for modeling the scattering mechanisms of temperate ice with various surface conditions. / text
222

The influence of CO₂ pricing on NOx emissions programs

Paine, Jeffery Hubbard 14 February 2011 (has links)
Electricity generating units (EGUs) are major emitters of both nitrogen oxides (NOx) and CO₂, and cap-and-trade programs are either currently used or proposed as management strategies for both pollutants. Emission cap and trade programs for these two pollutants have generally been considered independently, but since each EGU will have a characteristic NOx to CO₂ emission ratio, these programs are inherently connected. This thesis examines the extent to which CO₂ emission pricing and NOx emission markets are likely to influence each other, using Texas as a case study. The relationship is first demonstrated with a simple scenario of four power plants, followed by a second scenario accounting for the largest 34 plants in Texas. The analysis demonstrates that future CO₂ pricing will cause NOx emissions markets to be inefficient at reducing emissions through changes in the dispatching order. There will also exist a greater potential for NOx price spikes. Two plausible alternatives to this problem are suggested: a temporally- and spatially-variable NOx program, or increased emphasis on retrofitting the existing fleet of power plants for NOx reduction. / text
223

Essays in environmental regulation and firm dynamics

Dardati, Evangelina Alejandra 22 June 2011 (has links)
In this dissertation, I study the effect of environmental regulation on firm behavior. In the first chapter, I use a dynamic model to quantify the effects on exit, entry, investment and welfare of different allocation schemes of a cap-and-trade program. I focus on allocation rules regarding closing plants and new entrants. I calibrate the model with data from the US power plants and perform two policy experiments: first I quantify the effects of the introduction of a cap-and-trade program; second, I do a counterfactual where I switch the allocation rule and study the effect on the new equilibrium and welfare. In the second chapter of this dissertation, I ask whether multinational firms are harmful for a host country environment. I use plant-level data from Chile and find empirical evidence that multinational are cleaner than domestic plants. Based on the trade literature, I build a model where I add environmental regulation and a technology choice. The model proposes a new explanation of why multinationals firms might be cleaner than their domestic peers. I get policy implications from the model and test them with the data. In the third chapter, I study the relation between free permit allocation in a cap-and-trade program and financial constraints. I use the change in the permit prices and the heterogeneity in permit allocation to identify financial constraints for the investor-owned utilities in the electricity sector. / text
224

Return on diversity : a study on how diversity in board of directors and top management teams affects firm performance

Pohjanen, Becky, Bengtsson, Douglas January 2010 (has links)
Today, gender quotation in the Board of Directors has become an important political question that is being discussed not only in Sweden but in several other countries as well. However, research on gender diversity and, for that matter, other forms of diversity in the corporate world is not something new. Diversity in Board of Directors and Top Management Teams and how it affects firm performance have been the topic of many researches the last two decades. Nevertheless, there are still many unanswered questions in this field that need to be answered. The purpose of this dissertation is to study how diversity in BoDs and TMTs affect firm performance. We used five different diversity variables, tenure, age, education, nationality and gender in our research and we tested them separately to see how they each affect firm performance. Because there is limited previous research conducted on diversity in Sweden and on Swedish firms, this dissertation attempts to fill that gap. This study is conducted on Swedish firms that are listed on large cap on Stockholm stock exchange. We used several ways to measure the five different diversity variables in both BoDs and TMTs. Firm performance was measured by using two well established measurements, Return on Equity and Return on Assets. We developed ten hypotheses to test how diversity affects firm performance; some diversity variables had positive effect on firm performance, while others had negative effect. The hypotheses are based on earlier research. There are mixed results from our study; seven out of ten hypotheses had to be rejected due to insignificant relationship between diversity and firm performance. Three hypotheses were rejected, even though they showed a significant relationship between diversity and firm performance, because the relationship was the opposite of our hypotheses. One reason for these results can be that there is low diversity in both BoDs and TMTs, and this makes it difficult to measure and establish a relationship between diversity and firm performance.
225

Connections between Climate Policy and Forests in the Western Climate Initiative Cap-and-Trade System

Roberts, ALLAN 30 October 2009 (has links)
The Western Regional Climate Action Initiative (WCI) was signed by the governors of Arizona, California, New Mexico, Oregon, and Washington, on February 26, 2007. Upon the release of the September 2008 Design Recommendations for the WCI Regional Cap-and-Trade Program, the WCI also included Montana, Utah, and the Canadian provinces of British Columbia, Manitoba, Ontario, and Quebec. A WCI goal is to reduce regional greenhouse gas (GHG) emissions 15% below 2005 levels by 2020. It has previously been recognized that the region’s forests can be important carbon sinks and sources, and it has been suggested that the carbon-storage capacity of forests may have economic value. Here, connections between forests and the developing WCI cap-and-trade system design are examined. Qualitative comparative analysis is used to examine characteristics of US states participating in the WCI. Content analysis is used to identify what advocacy groups promote what forest-related WCI cap-and-trade rules. A combination of low per capita GHG emissions, and strong environmental politics, is found to be related to regional climate initiative participation by US states, with important exceptions among WCI participants. Forest industry presence alone does not obviously influence participation. Electric utility and industry groups, including the forestry sector, are found to support an extensive WCI carbon offset system. Forest industry groups are also found to support the carbon neutrality of forest biomass combustion, and oppose regulating forest carbon emissions. Several environmental non-governmental organizations are found to oppose extensive carbon offset use, and oppose the unconditional consideration of biomass combustion as carbon neutral. Forest related aspects of the WCI Design Recommendations of September 2008 are found to largely agree with forest industry advocated policies. Some WCI provisions may provide incentives for forest carbon loss, or weaken the GHG emissions cap. Three recommendations are made: consideration should be given to appropriately discounting forest offset projects to address carbon emissions leakage; forest carbon emissions from land conversion should be accounted for; combustion of forest biomass from old-growth forests should not be considered carbon neutral. / Thesis (Master, Environmental Studies) -- Queen's University, 2009-10-29 22:29:48.499
226

Influence of Soil Cap Depth and Vegetation on Reclamation of Phosphogypsum Stacks in Fort Saskatchewan, Alberta

Turner, Elizabeth Lenore Unknown Date
No description available.
227

AN EMPIRICAL INVESTIGATION OF THE COMMON AGRICULTURAL REFORM PROCESS

FINO, CARLO 31 March 2015 (has links)
la tesi si divide in tre parti. La prima parte ripercorre l'evoluzione storica della PAC. La seconda è un'analisi econometrica delle riforme McSharry e Fischler mentre la terza è un'analisi del processo di riforma attuale / Thesis is divided in three parts. The first one is an historical illustration of the CAP in its "price support" period. The second is an econometric analysis of the effectiveness of the McSharry and Fischler's reforms. The third is an anakys of the current reform process
228

Investigating aberrant cell separation in sloughy, an Arabidopsis thaliana mutant allelic to schizoriza

Broad, Ronan Charles January 2014 (has links)
Plant growth and development depends on controlled cell expansion. This, in itself, is determined by the plant cell wall, a structural matrix of polysaccharides encasing the plant cell. One line of investigation that has proven particularly successful in elucidating the components of the plant cell wall machinery has been the forward genetic screens of cell wall mutants. In this study, the molecular and cellular characterisation of sloughy, a cell separation mutant in Arabidopsis thaliana, was commenced. This mutant has a striking phenotype, with files of elongating epidermal cells snaking away from the adjacent epidermal cells and from the underlying cortex, loosing contact from the side walls while remaining attached at the cell ends, in a manner reminiscent of border-like cells in the root cap of arabidopsis. The sloughy mutation was fine mapped to a short region on chromosome I using high resolution melt point analysis. On sequencing all five genes in this region, a single nucleotide mutation, introducing a stop codon, was detected in exon 2 in the previously-described heat shock transcription factor SCHIZORIZA that results in a truncated protein missing several conserved domains essential for activity. SCHIZORIZA acts as a cell fate determinate in the root meristem to promote cortex fate, while suppressing epidermal and root cap fate in the mature ground tissue. Although the literature on schizoriza mutants has focused on the developing root meristem, with little documentation on the cell separation phenotype further up in the roots, the investigation of a collection of schizoriza TILLING mutants revealed that aberrant cell separation was ubiquitous to schizoriza mutants with a severely truncated protein. To investigate cell identity in the mature roots, sloughy was crossed to GAL4-GFP enhancer trap lines that act as cell-specific markers. Epidermal identity lines revealed that sloughy possessed a supernumerary ground tissue layer with epidermal identity. A cortex and endodermal line revealed that these two identities are restricted to the endodermal layer and the next ground tissue layer out. There was no indication of root cap identity in the mature root with any of the root cap lines used, although partial lateral root cap identity has been previously described in the epidermal and subepidermal cell layers in the meristem of schizoriza mutants expressing SOMBRERO-GFP, a lateral root cap-specific transcription factor. Immunolabelling of cell wall epitopes revealed that the JIM13 antibody, which specifically labels arabinogalactan-proteins in wild-type root caps, often labelled the epidermal cells and surrounding mucilage further up the in the roots of sloughy. The aberrant cell separation present in sloughy is thought to be a consequence of epidermal cells possessing partial lateral root cap identity. The data on sloughy/schizoriza is sufficient to generate a model on how a meristem developmental gene can generate a cell separation phenotype in the mature roots. Loss of SCHIZORIZA causes confused cell identity in the root meristem that results in an epidermal and subepidermal layer possessing mixed epidermal and lateral root cap identity. The distinctive properties of border-like cells in the root cap of arabidopsis have been linked to unique cell wall maturation and developmental processes, implicating the cellulases CEL3 and CEL5, the pectin glycosyltransferase QUA1, the pectin methyltransferase QUA2 and other pectolytic enzymes. The ectopic expression of these cell wall enzymes in the epidermal and subepidermal layers of sloughy roots result in reduced adhesion along the sides of the cell, while the ends remain attached, causing the observed cell separation phenotype.
229

Satellite observations of auroral acceleration processes

Eliasson, Lars January 1994 (has links)
Measurements with satellite and sounding rocket borne instruments contain important information on remote and local processes in regions containing matter in the plasma state. The characteristic features of the particle distributions can be used to explain the morphology and dynamics of the different plasma populations. Charged particles are lost from a region due to precipitation into the atmosphere, charge exchange processes, or convection to open magnetic field lines. The sources of the Earth’s magnetospheric plasma are mainly ionization and extraction of upper atmosphere constituents, and entry of solar wind plasma. The intensity and distribution of auroral precipitation is controlled in part by the conditions of the interplanetary magnetic field causing different levels of auroral activity. Acceleration of electrons and positive ions along auroral field lines play an important role in magnetospheric physics. Electric fields that are quasi-steady during particle transit times, as well as fluctuating fields, are important for our understanding of the behaviour of the plasma in the auroral region. High-resolution data from the Swedish Viking and the Swedish/German Freja satellites have increased our knowledge considerably about the interaction processes between different particle populations and between particles and wave fields. This thesis describes acceleration processes influencing both ions and electrons and is based on in-situ measurements in the auroral acceleration/heating region, with special emphasis on; processes at very high latitudes, the role of fluctuating electric fields in producing so called electron conics, and positive ion heating transverse to the geomagnetic field lines. / <p>Diss. (sammanfattning) Umeå : Umeå universitet, 1994, härtill 6 uppsatser.</p> / digitalisering@umu.se
230

Climate Change Leaders and Laggards: An Analysis of Initiatives in China, the United States, and California, and Their Potential for Collaboration

Akiyama, Taryn 01 January 2014 (has links)
The purpose of this thesis is to analyze climate change initiatives in China, the United States, and California, determine where they fall on a spectrum from climate change leader to climate change laggard, and evaluate the need for more effective collaboration among these entities in order to collectively tackle the global threat of climate change. This thesis supplements existing literature in the field by synthesizing the climate change activities of three important players in the global arena: China, the United States, and California. This thesis is different from other research, however, by underscoring the collaboration between these three entities and specifically recommending cap and trade as a mechanism through which to reduce greenhouse gas emissions. In this thesis, I claim that on a spectrum from climate change laggard to climate change leader, the United States settles as a laggard, California emerges as a leader, and contrary to popular belief, I argue that China is transitioning between the two. Moreover, I emphasize the importance of more collaboration – especially more substantive collaboration – between these key players in order to achieve significant global emissions reductions because they will stimulate other partnerships around the world and trigger more collective action on climate change. Finally, I offer cap and trade as a viable option through which these three entities can work together to reduce their contribution to global greenhouse gas emissions.

Page generated in 0.0218 seconds