• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 8
  • 1
  • 1
  • Tagged with
  • 17
  • 17
  • 17
  • 17
  • 6
  • 5
  • 4
  • 4
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 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

Trade barriers, international business, and the environment

Baggs, Jennifer Jane 11 1900 (has links)
This dissertation consists of three chapters discussing the effects of changing trade barriers for Canadian firms and a final chapter investigating hazardous waste trade, one of the important environmental issues in international business. The first three chapters use simple theoretical structures and firm level data to examine the evolution of Canadian manufacturing following the tariff changes imposed by the Canada-US Free Trade Agreement. Chapter one considers the influence of falling tariffs on firm survival, chapter two investigates how trade liberalization effects firm growth in terms of size and productivity, and the third chapter considers the implication o f falling trade barriers for firm financial structure. The fourth chapter diverges from the first three to explore the determinants of international shipments in hazardous waste using a gravity model with factor endowment conditions and waste trade data from 89 countries.
2

A quantitative spatial thoroughness methodology for environmental site characterization

Tsai, Yi-Chang 08 1900 (has links)
No description available.
3

Trade barriers, international business, and the environment

Baggs, Jennifer Jane 11 1900 (has links)
This dissertation consists of three chapters discussing the effects of changing trade barriers for Canadian firms and a final chapter investigating hazardous waste trade, one of the important environmental issues in international business. The first three chapters use simple theoretical structures and firm level data to examine the evolution of Canadian manufacturing following the tariff changes imposed by the Canada-US Free Trade Agreement. Chapter one considers the influence of falling tariffs on firm survival, chapter two investigates how trade liberalization effects firm growth in terms of size and productivity, and the third chapter considers the implication o f falling trade barriers for firm financial structure. The fourth chapter diverges from the first three to explore the determinants of international shipments in hazardous waste using a gravity model with factor endowment conditions and waste trade data from 89 countries. / Business, Sauder School of / Graduate
4

Chromium contamination in the vicinity of [the] Xstrata Wonderkop plant.

Sedumedi, Hilda N. January 2009 (has links)
M. Tech. Chemistry. / The aim of this study was to develop and evaluate an analytical method for the determination of Cr(VI) in ferrochrome dusts and to apply the method in the analysis of environmental samples (grass, soil and tree bark) for Cr(VI) content (that might be caused by dust emissions originating from the smelter). Both the public and Xstrata Wonderkop ferrochrome plant will benefit from data of Cr(VI) determination generated from the study. The information can potentially be incorporated into health risk assessments of the affected geographical areas. The results of the investigation showed that ferrochrome smelter dust emissions were the source of contamination of the environment with Cr(VI). With time, Cr(VI) could accumulate in soil to unacceptable levels, thereby endangering both plants and animals.
5

A preliminary study on the Hong Kong external trade of non-ferrous metal waste (and scrap) and other potentially hazardous wastematerials

Leung, Oi-kwan, Winnie., 梁愛群. January 1995 (has links)
published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management
6

Deterministic vs probabilistic ecological risk assessment modeling at hazardous waste sites : a comparative case study

Sorenson, Mary T. 05 1900 (has links)
No description available.
7

Temperature dependent PCDD/PCDF product distributions from phenols

Yang, Yun 05 1900 (has links)
No description available.
8

Copper migration through petroleum-treated soils

Woods, William Eric January 1990 (has links)
The purpose of the project was to determine the effect of various petroleum amendments on the migration rate of Cu. The petroleum amendments used in this research are frequently added to the soil surface in petroleum landfarming. Such petroleum wastes often contain significant amounts of Cu and other metals.Soil columns were amended with citric acid, used crankcase oil and Illinois crude oil. Each amendment was spiked (treated) with three different concentrations of Cu and each treatment was replicated three times. The columns were leached once per week, for ten weeks, with distilled water acidified to pH 4.5 to simulate acid rain. Leachate from the soil columns was analyzed weekly for total Cu. At the end of the ten week period, the soil was analyzed for Cu and TOC content at 7 cm intervals to determine the amount of migration by Cu and the organic amendments, resectively. The soil (a Glynwood silt loam) and the organic amendments were each analyzed for total Cu to determine background levels. The soil was analyzed for pH, TOC, electrical conductivity and soil texture.Analysis of the leachate and soil showed differential migration of Cu through the soil columns. Significant levels of Cu leached in the columns amended with citric acid (as high as 85.3 mg/L) in the first 3 weeks of the study. The Cu content of the leachate from columns amended with crude petroleum were at approximately background levels (5.5 mg/L) as was the leachate from columns amended with crankcase oil (0.2 mg/L). In the later weeks of the research, as the petroleum amendments were broken down by microorganisms, some Cu was chelated to small fragments of the petroleum and leached through the soil columns. Most of the Cu appeared to remain on the surface of the columns, bound to the petroleum amendments. Analysis of the soil, for total Cu content with depth, showed very little Cu accumulation at any depth in the soil column, beyond the soil surface. In most cases Cu levels remained near the background levels found in the control columns.Moderate correlation was found (r2 = .59 for crude oil; r2 = - .54 for crankcase oil; r2 = .85 for citric acid) between Cu levels and TOC levels in the soil columns with depth.From the results of the current study it can be inferred that practices such as petroleum landfarming and land disposal of some hazardous materials may allow for the migration of both the applied petroleum wastes and any metals which may be contained within. / Department of Natural Resources
9

The effects of a toxic metals spill on aquatic fauna in streams near Culpeper, Virginia

Barker, Shelley Jaye January 1983 (has links)
The event which prompted this study was a spill of two hundred thousand gallons of chromium-arsenic-copper solution from a holding pond into an adjacent, first-order stream on January 31, 1981. The holding pond, owned by Culpeper Wood Preservers Company of Culpeper, Virginia, was used to store wastes generated during the wood-preserving process. The stream is a tributary of Jonus Run whose waters eventually empty into the Rappahannock River. A waste-chemical landfill, located on a different first-order stream, but within the same vicinity and watershed, also threatens the water quality of the area. It is known as Lamphier landfill and industrial solvents, paint thinner's and metals were dumped there. The landfill is located on an unnamed tributary which also drains into Jonas Run. Aquatic insects and detritus were collected at all sampling sites. Crayfish and small fish were collected whenever possible. Various water quality parameters were measured at each site. Also, aquatic insect community structure and function, concentration of metals in aquatic insects and the pathway of metals through the aquatic food web was studied at each site. Generally, the concentrations of metals in waters near the spill and landfill areas were higher in chromium and arsenic then would normally be expected. Also, the concentrations of most metals, especially copper, were higher at downstream contaminated waters (rather than at upstream reference sites). The community structure and functional analysis showed that the sampling sites were influenced by various factors (agricultural runoff, road runoff, silt, heavy metal pollution, possible chemical pollution). Unfortunately, it was difficult to distinguish which effects were caused by heavy metal or chemical contaminants. Consequently, the results of the community structure and function analysis were inconclusive. Metals pollution may have contributed to the concentrations of metals found in aquatic insects collected at only one site. However the analysis of the concentration of metals found in aquatic insects from the remaining sites were inconclusive. The concentrations of metals found in detritus and crayfish suggested that metal contamination from the spill site did occur, however biomagnification did not. / M.S.
10

Hazardous waste treatment and disposal: alternative technologies and groundwater impacts

Robinson, Janet E. January 1986 (has links)
The most important thermal, chemical, physical, and biological methods for treating hazardous wastes and the fate of their land-disposed residues are reviewed and evaluated. Technologies are described as major, minor, and emerging according to their stage of development or application to hazardous waste; major ones include rotary kiln, liquid injection, and cement kiln incineration; neutralization, chemical oxidation-reduction, and ion exchange; filtration, distillation and settling techniques; and activated sludge, aerated lagoon, and landfarming treatment. Emerging technologies include molten salt and fluidized- bed combustion, liquid-ion extraction and other processes, none of which are considered to be outside the realm of current or future economic feasibility. In addition, waste reduction strategies and the land burial of stabilized/solidified wastes are discussed. Residues from these technologies vary widely according to waste type and composition, but a common component in many of them is heavy metals, which, as elements, cannot be further degraded to other products. The results of the available literature suggests that these metals will be retained in clay liners beneath a landfill through the mechanism of cation exchange, with the adsorption of metals favored by their smaller hydrated size, lower heat of hydration, and in some cases, higher valences than the naturally occurring alkali earth metals. Other important factors include ionic activity, the pH and ionic strength of the solution, the presence of complexing agents, and the possible surface heterogeneity of the clay. In soils, metal binding through cation exchange with clay is augmented by adsorption onto iron and manganese oxides and complexing with organic matter such as humic acids. Many field studies with landfarmed metal-bearing wastes show that these mechanisms are usually sufficient to retain metals to within several inches of their zone of application. / M.S.

Page generated in 0.1368 seconds