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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.
91

Sublethal Effects of Crude Oil and Chemical Dispersant on the Eastern Oyster (<em>Crassostrea virginica</em>) at Multiple Life History Stages

Garcia, Sara Marie 15 March 2018 (has links)
Oil spills in the marine environment can threaten vulnerable ecosystems that support ecologically and economically significant organisms, such as the eastern oyster (Crassostrea virginica), in coastal habitats. The use of chemical dispersant (Corexit 9500) was applied as a cleanup effort in response to the Deepwater Horizon blowout to minimize crude oil slicks, but also resulted in increased concentrations of polycyclic aromatic hydrocarbons in the water column. The effects of increased soluble fractions of crude oil and dispersant components may be harmful to marine organisms. This study aimed to investigate possible sublethal impacts to the eastern oyster at multiple life history stages in order to understand potential implications on performance at an organismal, population, and ecosystem levels. Specifically, this study addressed 1) veliger swimming, 2) pediveliger settlement rates, 3) pollutant induced larval inactivity and 4) adult clearance rates after acute exposures to relevant concentrations (10 – 100 µL L-1) of water accommodated fractions of crude oil (WAF) and with a combination of chemical dispersant (CEWAF). No significant differences were observed in any tested swimming kinematics between controls and WAF or CEWAF treatments after 24 hour exposures for early staged veligers at concentrations up to 100 µL L-1 WAF and CEWAF. However, settlements rates of competent pediveligers were significant decreased compared to control (52.1 % s.d. 1.66) rates at concentrations of 50 µL L-1 WAF (30.9% s.d. 6.16) and 10 (41.2 % s.d. 0.857) and 50 (22.0% s.d. 1.23) µL L-1 CEWAF. Later staged larvae also showed increased vulnerability to oil pollution given that a higher percentage of organisms were inactive (48.3% s.d. 4.80) compared to early staged larvae (12.7% s.d. 7.68 ) after initial exposure at 50 µL L-1 CEWAF. Based on this result, we assumed effects of oil pollution were not manifested until the later larval life history stage evident by metamorphosis failure during the complex settlement transformation that results in reduced spat and eventually reduced adult oysters. Adult oysters were also exposed to increasing concentrations of WAF and CEWAF for 24 hours and feeding experiments were conducted in both clean seawater and the same oiled seawater conditions as their initial exposure. Oysters fed in oiled seawater had decreased clearance rates, but oysters fed in clean water had increased clearance rates, suggesting feeding efficiency can be returned to control rates when moved to the presence of clean water. However, our long term study conducted in clean seawater suggested of the oysters exposed to crude oil only (9.31 L h-1 g-1 s.d. 2.04) are able to return to clearance rates comparable to controls (7.69 L h-1 g-1 s.d. 1.89) after the 33 day time period but oysters exposed to crude oil with a combination of chemical dispersant (2.12 L h-1 g-1 s.d. 1.08) were not. Decreased feeding efficiency can have negative impacts on water quality in estuarine ecosystems that support productive habitats. Understanding the impacts of crude oil, and crude oil with a combination of chemical dispersant on ecologically significant organisms can aid in future oil spill response decisions in order to minimize environmental impacts.
92

IS OPEC'S ALLOCATION OF CRUDE OIL PRODUCTION EFFICIENT? (Bachelor Thesis in Economics) / IS OPEC‟S ALLOCATION OF CRUDE OIL PRODUCTION EFFICIENT? (Bachelor Thesis in Economics)

ud din, Fateh, hazar, Hazal, salih, ali January 2009 (has links)
<p>The foundation of OPEC (Organization of Oil Exporting Countries) was laid in the early 1960‟s by the five major oil exporters, Iran, Iraq, Kuwait, Saudi Arabia and Venezuela, in Baghdad, Iraq. OPEC is supposed to allocate its production level among its member countries based on cartel- dominant firm model, for profit maximization.</p>
93

Trading Oil Futures

He, Qiao January 2008 (has links)
<p>Oil is an important energy source and a necessary industrial raw material. Every country’s economic growth and the daily life of its people are dependent on this energy form.</p><p>Historically, the oil prices have varied significantly on the world market. This led to at least two oil crises when prices increased in a very fast pace. In order to reduce such rapid fluctuations, oil was introduced at so called commodity exchanges. At such trading places oil could be traded openly for future delivery and hence the market was aware of price changes in advance. A commodity exchange sells special contracts in the form of so called “futures”. In fact there are many different contracts, each exchange has its own set of them covering for a number of different oil types. This thesis deals with these contracts and how they are traded.</p>
94

Oljeprisets påverkan på aktiekurserna i internationella och svenska oljebolag

Werninger, Nichlas January 2010 (has links)
<p>Uppsatsen studerar hur aktiekurser i oljerelaterade bolag har reagerat vid kraftiga svängningar av oljepriset och undersöker hur oljepriset och aktiekurserna följer varandra under en längre period. Uppsatsen använder sig av en event studie samt ett korrelationstest som metod. Det ingår totalt 8 bolag i studien som undersöks mot Brent råolja. Studien visar att företagen reagerar vid en kraftig rörelse i oljepriset samt att det finns en stark korrelation mellan oljepriset och aktiekurserna i majoriteten av företagen.</p>
95

IS OPEC'S ALLOCATION OF CRUDE OIL PRODUCTION EFFICIENT? (Bachelor Thesis in Economics) / IS OPEC‟S ALLOCATION OF CRUDE OIL PRODUCTION EFFICIENT? (Bachelor Thesis in Economics)

ud din, Fateh, hazar, Hazal, salih, ali January 2009 (has links)
The foundation of OPEC (Organization of Oil Exporting Countries) was laid in the early 1960‟s by the five major oil exporters, Iran, Iraq, Kuwait, Saudi Arabia and Venezuela, in Baghdad, Iraq. OPEC is supposed to allocate its production level among its member countries based on cartel- dominant firm model, for profit maximization.
96

An economic analysis of crude oil exploration in Saskatchewan and Alberta

Kamsari, Haul 28 February 2005
The International market of crude oil and natural gas is well established and very competitive. Knowledge about costs is important in helping to understand the current position of producers within the industry. In the eyes of the producers, the lower the costs the more profitable they will become given the price of crude. This thesis focuses on an economic analysis of crude oil exploration in Saskatchewan and Alberta. In a competitive market, the producers require estimates of finding costs in both regions. The public policies that are designed to encourage crude exploration also rely heavily on reliable estimates of these costs. The results show that Saskatchewans per-unit finding cost is significantly lower than Albertas in spite of the geological differences between the two provinces. The finding costs are estimated by using a methodology (Uhler 1979) that has been widely accepted within economic literature of non-renewable resources. The results support the hypothesis that finding costs in both regions are increasing and the argument that these costs will converge in the long-run, except for the last six years of the analysis.
97

An economic analysis of crude oil exploration in Saskatchewan and Alberta

Kamsari, Haul 28 February 2005 (has links)
The International market of crude oil and natural gas is well established and very competitive. Knowledge about costs is important in helping to understand the current position of producers within the industry. In the eyes of the producers, the lower the costs the more profitable they will become given the price of crude. This thesis focuses on an economic analysis of crude oil exploration in Saskatchewan and Alberta. In a competitive market, the producers require estimates of finding costs in both regions. The public policies that are designed to encourage crude exploration also rely heavily on reliable estimates of these costs. The results show that Saskatchewans per-unit finding cost is significantly lower than Albertas in spite of the geological differences between the two provinces. The finding costs are estimated by using a methodology (Uhler 1979) that has been widely accepted within economic literature of non-renewable resources. The results support the hypothesis that finding costs in both regions are increasing and the argument that these costs will converge in the long-run, except for the last six years of the analysis.
98

Essays on Pricing Behaviors of Energy Commodities

Qin, Xiaoyan 2011 May 1900 (has links)
This dissertation investigates the pricing behaviors of two major energy commodities, U.S. natural gas and crude oil, using times series models. It examines the relationships between U.S. natural gas price variations and changes in market fundamentals within a two-state Markov-switching framework. It is found that the regime-switching model does a better forecasting job in general than the linear fundamental model without regime-switching framework, especially in the case of 1-step-ahead forecast. Studies are conducted of the dynamics between crude oil price and U.S. dollar exchange rates. Empirical tests are applied to both full sample (1986—2010) and subsample (2002—2010) data. It is found that causality runs in both directions between the oil and the dollar. Meanwhile, a theoretical 5-country partial dynamic portfolio model is constructed to explain the dynamics between oil and dollar with special attention to the roles of China and Russia. It is shown that emergence of China‘s economy enhances the linkage between oil and dollar due to China's foreign exchange policy. Further research is dedicated to the role of speculation in crude oil and natural gas markets. First a literature review on theory of speculation is conducted. Empirical studies on speculation in commodity markets are surveyed, with special focus on energy commodity market. To test the theory that speculation may affect commodity prices by exaggerating the signals sent by market fundamentals, this essay utilizes the forecast errors from the first essay to investigate the forecasting ability of speculators' net long positions in the market. Limited evidence is provided to support the bubble theory in U.S. natural gas market. In conclusion, this dissertation explores both fundamentals and speculators' roles in the U.S. natural gas and global crude oil markets. It is found that market fundamentals are the major driving forces for the two energy commodities price booms seen during the past several years.
99

Developing Electrospray-Assisted Pyrolysis Ionization/Mass Spectrometry for Rapid Characterization of Trace Polar Components in Macromolecules

Hsu, Hsiu-Jung 24 July 2006 (has links)
ABSTRACT In this paper we describe the use of electrospray-assisted pyrolysis ionization/mass spectrometry (ESA-Py/MS) to selectively ionize trace polar compounds that coexist with large amounts of nonpolar hydrocarbons in synthetic polymer, crude oil, amber, humic substances, and rubber. Samples of different origins are distinguished rapidly by their ESA-Py mass spectra without prior separation or chemical pretreatment. During ESA-Py analysis, the samples in their solid or liquid states were pyrolyzed at 590 ¢XC using a commercial Curie-point pyrolytical probe; the gaseous pyrolysates were transferred into a glass reaction cell; the polar compounds (M) in the pyrolysates were then ionized in the form of protonated molecules (MH+), through their reactions with the charged species in the ESI plum. Although the major components of the pyrolysates are nonpolar hydrocarbons, their lack of functional groups that can receive a proton in the ESA-Py source results in no hydrocarbon ion signals being produced; thus, the ions detected in ESA-Py mass spectra all result from trace polar component in the pyrolysates.
100

Trading Oil Futures

He, Qiao January 2008 (has links)
Oil is an important energy source and a necessary industrial raw material. Every country’s economic growth and the daily life of its people are dependent on this energy form. Historically, the oil prices have varied significantly on the world market. This led to at least two oil crises when prices increased in a very fast pace. In order to reduce such rapid fluctuations, oil was introduced at so called commodity exchanges. At such trading places oil could be traded openly for future delivery and hence the market was aware of price changes in advance. A commodity exchange sells special contracts in the form of so called “futures”. In fact there are many different contracts, each exchange has its own set of them covering for a number of different oil types. This thesis deals with these contracts and how they are traded.

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