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Behaviour of Oxygenates and Aromatic Hydrocarbons in Groundwater from Gasoline ResidualsMocanu, Marian January 2006 (has links)
ABSTRACT
This study focuses on the dissolution and near-source attenuation of oxygenated gasoline hydrocarbons in groundwater from two gasoline residual sources: one containing gasoline with 9.8% methyl tert butyl alcohol (MTBE) and 0.2% tert-butyl alcohol (TBA) (GMT source) and the other containing gasoline with 10% ethanol (E10 source). The sources were injected into a shallow sand aquifer, leaving a residual plume to dissolve under natural gradient conditions.
The MTBE plume (from the GMT source) and the ethanol plume (from the E10 source) were compared with predictions by the BIONAPL numerical model assuming ideal source dissolution and no biodegradation of the oxygenates or aromatic hydrocarbons. While the complete mass of injected MTBE appeared to pass row 2, little MTBE was found further downgradient. This mass loss was considered to be an artifact of the monitoring system and of possible biodegradation. The ethanol mass flux was better captured in the E10 gate. Essentially all the ethanol from the E10 source also passed row 2, but, the ethanol mass flux decreased somewhat from row 2 to row 4. The better mass recovery may reflect that the ethanol plume remained more in the center of the monitoring network as compared to the MTBE plume some of which may have bypassed the monitoring fence. MTBE, TBA, and ethanol in the model were assumed to dissolve at equilibrium. The MTBE and TBA concentration breakthrough curves are generally consistent with equilibrium dissolution. However, the mass flux values suggest non ideal dissolution. The ethanol concentration breakthrough curves and mass flux are consistent with equilibrium dissolution. Also, the observed concentrations were often higher than predicted at later times. These features could be due to non-equilibrium (kinetically-limited) dissolution However, non-ideal source conditions may have arisen due to most of the oxygenates being dissolved into the water injected along with the gasolines thus distributing the residual gasoline in a non-uniform manner. The concentrations of aromatics are higher than expected from the BIONAPL model and are consistent with tailing expected with non-equilibrium dissolution. However, the probable complexity of the source concentration distribution likely account for much of the concentrations variability.
There were insufficient electron acceptors to support complete mineralization of either the oxygenates or the BTX-TMB compounds. Although, evidence of weak MTBE biodegradation was found, the major mass loss seemed to be related to the uncertainties in the monitoring network. Some ethanol mass loss could be attributed to fermentation to organic acids (which were not sought in the field experiment). The persistence of BTX-TMB through the gates seemed to be slightly greater in the presence of ethanol.
The field study was also used to test the Ratio Mass Estimation (RME) method of estimating the initial NAPL mass in the source from downgradient contaminant concentrations. The method was found reasonably reliable if the downgradient concentrations were collected close to the source where biodegradation was minor.
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Behaviour of Oxygenates and Aromatic Hydrocarbons in Groundwater from Gasoline ResidualsMocanu, Marian January 2006 (has links)
ABSTRACT
This study focuses on the dissolution and near-source attenuation of oxygenated gasoline hydrocarbons in groundwater from two gasoline residual sources: one containing gasoline with 9.8% methyl tert butyl alcohol (MTBE) and 0.2% tert-butyl alcohol (TBA) (GMT source) and the other containing gasoline with 10% ethanol (E10 source). The sources were injected into a shallow sand aquifer, leaving a residual plume to dissolve under natural gradient conditions.
The MTBE plume (from the GMT source) and the ethanol plume (from the E10 source) were compared with predictions by the BIONAPL numerical model assuming ideal source dissolution and no biodegradation of the oxygenates or aromatic hydrocarbons. While the complete mass of injected MTBE appeared to pass row 2, little MTBE was found further downgradient. This mass loss was considered to be an artifact of the monitoring system and of possible biodegradation. The ethanol mass flux was better captured in the E10 gate. Essentially all the ethanol from the E10 source also passed row 2, but, the ethanol mass flux decreased somewhat from row 2 to row 4. The better mass recovery may reflect that the ethanol plume remained more in the center of the monitoring network as compared to the MTBE plume some of which may have bypassed the monitoring fence. MTBE, TBA, and ethanol in the model were assumed to dissolve at equilibrium. The MTBE and TBA concentration breakthrough curves are generally consistent with equilibrium dissolution. However, the mass flux values suggest non ideal dissolution. The ethanol concentration breakthrough curves and mass flux are consistent with equilibrium dissolution. Also, the observed concentrations were often higher than predicted at later times. These features could be due to non-equilibrium (kinetically-limited) dissolution However, non-ideal source conditions may have arisen due to most of the oxygenates being dissolved into the water injected along with the gasolines thus distributing the residual gasoline in a non-uniform manner. The concentrations of aromatics are higher than expected from the BIONAPL model and are consistent with tailing expected with non-equilibrium dissolution. However, the probable complexity of the source concentration distribution likely account for much of the concentrations variability.
There were insufficient electron acceptors to support complete mineralization of either the oxygenates or the BTX-TMB compounds. Although, evidence of weak MTBE biodegradation was found, the major mass loss seemed to be related to the uncertainties in the monitoring network. Some ethanol mass loss could be attributed to fermentation to organic acids (which were not sought in the field experiment). The persistence of BTX-TMB through the gates seemed to be slightly greater in the presence of ethanol.
The field study was also used to test the Ratio Mass Estimation (RME) method of estimating the initial NAPL mass in the source from downgradient contaminant concentrations. The method was found reasonably reliable if the downgradient concentrations were collected close to the source where biodegradation was minor.
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Retrofitting analysis of integrated bio-refineriesCormier, Benjamin R. 25 April 2007 (has links)
A bio-refinery is a processing facility that produces liquid transportation fuels
and/or value-added chemicals and other products. Because of the dwindling resources
and escalating prices of fossil fuels, there are emerging situations in which the economic
performance of fossil-based facilities can be enhanced by retrofitting and incorporation of
bio-mass feedstocks. These systems can be regarded as bio-refineries or integrated fossilbio-
refineries. This work presents a retrofitting analysis to integrated bio-refineries.
Focus is given to the problem of process modification to an existing plant by considering
capacity expansion and material substitution with biomass feedstocks. Process integration
studies were conducted to determine cost-effective strategies for enhancing production
and for incorporating biomass into the process. Energy and mass integration approaches
were used to induce synergism and to reduce cost by exchanging heat, material utilities,
and by sharing equipment. Cost-benefit analysis was used to guide the decision-making
process and to compare various production routes. Ethanol production from two routes
was used as a case study to illustrate the applicability of the proposed approach and the
results were bio-refinery has become more attractive then fossil-refinery.
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Impact of ethanol expansion on the cattle feeding industryDaley, Erin 17 September 2007 (has links)
The U.S. has a history of producing surplus corn, but the current and projected growth
in ethanol production combined with strong feed and export demand is causing an
overall increase in corn utilization. Although livestock feeders are projected to remain
the largest users of corn, corn utilization can be reduced if ethanol co-products are used
to replace a portion of corn in finishing rations.
The objective of this study was to determine the economic trade-offs for cattle
feeders when facing higher corn prices and increasing supplies of ethanol co-products.
A stochastic partial budget model was used to determine the impact on the cost of gain
when ethanol co-products are substituted into rations at varying inclusion rates. The
model was built for all four major cattle feeding states: Texas, Nebraska, Kansas, and
Colorado. Ration scenarios were developed for each state, based on the research
results of feedlot nutrition and personal communication with feedlot operators. The
various scenarios were simulated to determine the impacts of changing corn prices,
corn processing costs, cattle performance, and feeding and transportation costs for Wet
DistillerâÂÂs Grains with Solubles (WDGS) on the key output variable, cost of gain.
The model results indicated when 15 percent WDGS (on a dry matter basis)
replaces a portion of corn and protein supplement, the simulated cost of gain is lower than the base ration scenario when the feedlot is located within 200 miles of ethanol
production. When feedlots are located more than 200 miles from an ethanol plant,
Dried DistillerâÂÂs Grains with Solubles (DDGS) can be fed to lower the cost of gain;
therefore, ethanol co-products can be fed to help offset potential increases in corn
prices.
The partial budget model is a useful tool for livestock, corn, and ethanol
producers who are attempting to determine the impacts of ethanol expansion on corn
price and utilization. Policy makers can also benefit from the model analysis as they
face decisions in the future regarding ethanol and farm policy alternatives.
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The role of circadian genes in tolerance to ethanol in Drosophila melanogasterPohl, Jascha Benjamin, 1981- 04 June 2012 (has links)
Alcoholism is a devastating inheritable disease that causes a large fiscal and societal impact worldwide. The fruit fly, Drosophila melanogaster, has proven to be a useful model system in identifying genetic factors underlying ethanol-associated behaviors. Many genes have been identified in the fly that are involved in the acquisition of tolerance, or the reduced response of an effect of a drug caused by previous exposure. In this thesis, I investigated whether circadian genes are involved in tolerance to ethanol in the fly. Circadian genes had previously been implicated in cocaine sensitization in flies, as well as some ethanol responses in mammals. I developed a novel assay using a bootstrapping paradigm to analyze tolerance to ethanol in the fly that allows for the investigation of multiple components of tolerance. I then used this assay to test whether circadian genes were necessary for the acquisition of tolerance in the fly. Interestingly, only some circadian genes affect tolerance to ethanol. These results argues that circadian genes are involved in tolerance to ethanol, but because some mutants are arrhythmic but still acquire tolerance, that they are acting in a role outside of the circadian system. While in the course of this work, I intended to investigate if these mutations affected ethanol preference in a two-choice assay. Before employing this assay, however, we wished to determine if flies prefer ethanol for its pharmacological effect or for its value as a food. Weperformed experiments in which flies had a choice between food supplemented with ethanol and food supplemented with an isocaloric carbohydrate. When presented with the isocaloric alternative, flies no longer demonstrated preference for ethanol. Flies will even stop showing preference for ethanol when switched to a balanced assay after preference has already been attained. We conclude that the flies prefer ethanol not because of its effect as a drug, but as a food source. / text
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A critical role for zinc in ethanol action at the glycine receptorMcCracken, Lindsay Marie 17 July 2012 (has links)
Ethanol is a widely used drug, yet an understanding of its sites and mechanisms of action remains incomplete. Among the protein targets of ethanol are glycine receptors (GlyRs). In addition to ethanol, zinc also modulates GlyR function. Although the individual effects of zinc and alcohols on GlyR function have been well studied, the combined effects of these agents have not been thoroughly examined. This project investigated the effects of zinc on alcohol action at the glycine receptor (GlyR). In Aim 1, the effects of zinc on ethanol modulation of GlyR function were tested and characterized in three GlyR [alpha] subunits ([alpha]1-3). Aim 2 explored a site of action for the augmenting effects of zinc on ethanol action at the GlyR. Mutant D80A GlyRs, which lack a zinc binding site (D80), were constructed and allowed us determine if this zinc binding site is important for the zinc/ethanol interactions that were observed in Aim 1. The effects of ethanol were reduced in mutant D80A GlyRs compared to wild type (WT). In addition, manipulating zinc levels in our buffers either by adding or chelating zinc did not change the magnitude of ethanol enhancement of mutant D80A GlyRs as it did in WT GlyRs suggesting that the D80 position is important for zinc modulation of ethanol action. Finally, Aim 3 extended the findings from Aims 1 and 2 by evaluating the effects of a GlyR point-mutation on alcohol consumption and other behavioral tests in mice. Glra1(D80A) knock-in mice provided an animal model for behavioral studies of zinc/ethanol interactions at the GlyR and showed decreased alcohol consumption and preference compared to their WT littermates. In addition, D80A KI mice had increased startle responses compared to their WT littermates. Other behavioral tests were also conducted including tests of ethanol motor incoordination and strychnine induced convulsions; there were no differences detected between KI and WT mice in these assays. Overall, our findings demonstrate that zinc is critical in determining the effects of ethanol at GlyRs and suggest that zinc signaling at the D80 position may be important for mediating the behavioral effects of ethanol action at GlyRs. / text
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Estimation of Ethanol/Water Solubility ProfilesMachatha, Stephen Gitu January 2006 (has links)
The goal of this study was to develop a simple means of estimating the cosolvent/water solubility profile using just the available properties (logKow, dielectric constant etc.) of the solute, cosolvent and water. Ethanol was used as the model cosolvent.One of the most commonly used polarity indicators is the octanol/water partition coefficient (logKow). Numerous programs are used to predict the logKow. The calculated values of logKow from three of the most commonly used programs ClogP®, ACD/logPdb® and KowWin® were compared to experimental values. It was found that all three programs have a user friendly interface but ClogP appears to be more accurate.While the ethanol/water solubility profiles of very polar and very non-polar drugs are monotonic, many semi-polar drugs show a maximum solubility at an ethanol volume fraction (fmax) between zero and one. A new empirical function that describes this deviation from linearity was applied to the experimental data forfifty-one compounds. The proposed model was a more accurate predictor of the co-solvent solubility profile than a general third order polynomial with the samenumber of parameters. The fmax value was also accurately predicted from the first derivative of the model.A sigmoidal relationship was observed between the value of fmax and logKow of the solute. Combining this sigmoidal relationship with the previously reportedlinear relationship between logKow and the initial slope of the plot of log solubility vs. ethanol composition enables the estimation of the totalethanol/water solubility profiles of semi-polar compounds from just logKow.A new bilinear function was also introduced to address the deviation from linearity. This model accounts for both the initial and terminal slopes in theethanol/water solubility profiles of semi-polar solutes. The proposed model is dependent only on logKow and an empirical constant that is cosolvent specific. It is also more accurate than the log-linear model and a general parabolic model.A solubility case study using Antalarmin, a novel stress inhibitor was performed.This study illustrates the use of cosolvents as solubility enhancers as well as pH,surfactants, complexants and lipid based systems.
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ECONOMIC ANALYSIS OF THE REGIONAL EFFECTS OF GRAIN-BASED ETHANOL PRODUCTION ON THE COMPETITIVENESS OF FED CATTLE PRODUCERS IN EASTERN AND WESTERN CANADADeJong, Alex 15 September 2011 (has links)
This thesis investigates the regional impacts that increased grain based ethanol production has the competitiveness of fed cattle producers in Eastern and Western Canada. A simulation model solves for the price of feed grains in Eastern and Western Canada and the United States. Fed Cattle Producer Surplus values are calculated as a baseline by which scenario results are compared.
Two scenarios are tested by the model, both applying increased ethanol production to the 2002 base year. Results show that 2008 ethanol production increases the price for feed grains in all three regions of the model by between 95% and 100%. Applying the projected ethanol production for 2015 to the model produces feed grain increases of greater than 200%. / Beef Research Council (BRCR, Advancing Canadian Agriculture and Agri-Food (ACAAF) program
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MODERATE ETHANOL CONSUMPTION BY THE PREGNANT GUINEA PIG INCREASES ETHANOL PREFERENCE IN OFFSPRINGShea, KAYLA 24 June 2009 (has links)
Ethanol teratogenicity involving the developing brain is the leading preventable cause of mental deficiency in the Western world. Chronic prenatal ethanol exposure (CPEE) may be a risk factor for ethanol abuse and altered responsiveness to nicotine in postnatal life. Previous studies in our laboratory have utilized maternal oral administration of a high-dose (4 g ethanol/kg maternal body weight/day) ethanol regimen that induces structural and functional deficits in the fetus and postnatal offspring. The objective of this thesis was to test the hypotheses that moderate CPEE produces in postnatal offspring: (i) structural and functional teratogenic effects; (ii) increased ethanol preference; (iii) altered responsiveness to acute nicotine; and (iv) increased nicotinic acetylcholine receptors (nAChR) in forebrain structures, namely the hippocampus and frontal cortex. Pregnant Dunkin-Hartley-strain guinea pigs were given 24-h access to aqueous ethanol solution (5%, v/v) sweetened with sucralose (1g/L) or aqueous sucralose solution (1g/L) throughout gestation. Spontaneous locomotor activity in an open field was measured in offspring on postnatal day (PD) 10. Beginning around PD 40, ethanol preference in the offspring was determined using a two-bottle-choice paradigm. Each animal was given 2-h daily access to aqueous ethanol solution (0 - 3%, v/v) and water over 33 days of testing. Subsequently, hippocampal and frontal cortical tissues were obtained for the measurement of nAChR population by radioligand binding. Moderate maternal consumption of the aqueous ethanol produced growth restriction in postnatal offspring of both sexes, and increased spontaneous locomotor activity in male offspring only. These postnatal outcomes are similar to the teratogenic effects produced by a high-dose, binge-type ethanol regimen. Compared with control, offspring from mothers that consumed ethanol throughout gestation exhibited greater preference for aqueous ethanol, and a decrease in the concentration of nAChRs in the frontal cortex, but not the hippocampus. These data demonstrate that, in the guinea pig, moderate maternal consumption of ethanol is a useful model for studying ethanol neurobehavioural teratogenicity; and chronic prenatal exposure to ethanol enhances ethanol preference in young adult offspring and altered expression of nAChRs in the frontal cortex. / Thesis (Master, Pharmacology & Toxicology) -- Queen's University, 2009-06-19 10:26:40.229
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Cellulosic ethanol feasibility frameworkSawatzky, Curtis 08 January 2013 (has links)
The objective was to create a feasibility framework for assessing the feasibility of a cellulosic ethanol refinery. In addition, the research aimed to create a base case scenario based on data from literature and conduct sensitivity analysis to determine significant parameters of a cellulosic ethanol refinery. The base case was found to be not feasible in the financial and economic analysis given the assumptions used.
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