Dopamine increases in the nucleus accumbens after contingent and noncontingent ethanol administration in rats, but the contributions of the core, coreshell border, and shell subregions to this response are unclear. Also, it is not fully understood if increases in dopamine under these circumstances are due to the pharmacological effects of ethanol, stimuli associated with administration, or both. The studies presented in this dissertation were conducted to investigate dopamine’s role in each of these accumbal regions during ethanol administration and presentation of associated stimuli. Using microdialysis, ethanol and dopamine concentrations in accumbal subregions were measured every five minutes before, during, and after either experimenter-delivered intravenous ethanol or operant ethanol self-administration. After intravenous ethanol infusions, the increase in dopamine in the shell of the accumbens was significantly higher than that observed in the core. During operant ethanol self-administration, the core, core-shell border, and shell, all exhibited significant increases in dopamine during transfer of the animal into the operant chamber, with animals trained to drink sucrose + ethanol showing significantly higher increases when compared to those trained to drink sucrose alone. Dopamine increased significantly only in the core-shell border during ethanol consumption, and dopamine levels in the core and shell responded in a similar manner during all phases of the experiment. Together, these results suggest that dopamine responses to intravenous ethanol infusions and operant ethanol self-administration are subregion specific. Also, while increases in dopamine resulting from intravenous ethanol infusions in naïve animals appear to be due to the pharmacological effects of the drug, increases in ethanol-experienced animals during transfer into the operant chamber, and during ethanol consumption, may also be due to stimuli associated with ethanol administration. / text

Thesis (MTech (Environmental Management))--Cape Peninsula University of Technology, 2018. / South Africa is taking a continental lead towards the transition of the green economy, and the energy sector has been identified as one of the cornerstones integral in this transition. This transition pays attention to alternative energy sources to gradually replace fossil fuels. Recently, the production of ethanol is seen as an energy source that is an integral player in achieving a green economy. The ethanol production project is linked to the improvement of the economy, and social well-being concomitant with the enhancement of the environmental quality tenets embodied by the green economy. Scholars have noted that these projects tend to ignore socio-economic realities of under privileged people especially in rural areas and small towns. While the green energy is often presented by the state there is, however, no evidence of the positive as well as negative impacts of ethanol projects on improving the livelihoods of the local communities or contributing to the substance of the local economies while protecting the quality of the environment. This thesis explored the subject of ethanol projects as green economic models in the context of the ethanol project in Cradock. The thesis investigated the socio-economic implications of the ethanol project in Cradock as a green economic model. The research study argues that the inclusion of the local people in decision making for the ethanol project is crucial to securing their benefits from the project. This means that local people should be involved early in the decision making process. Failure to engage the local residents in the initial stages of decision making, may create a lack of sense of ownership resulting in a lack of socio-economic benefits for the residents. The research study adopted a qualitative research design and an inductive approach. The ethanol project in Cradock was used as a case study for the research, and two sampling techniques, purposive sampling and random sampling were used. Interviews, questionnaires and observations were used to collect data from the residents of Cradock, the business sector (hospitality, tourism and agricultural retail), the emerging farmers, the farm workers, the Agrarian Research Development Agency, and Government Departments (Local Economic Development, Department of Agriculture, Department of Rural Development and Land Reform). The findings illustrate that the ethanol project in Cradock is not consistent with the tenets of a green economic model. The results suggested that the project does not improve the livelihood of the community or contribute to the sustenance of the local economies while protecting the quality of the environment. From an environmental perspective, while the ethanol project regarding providing ethanol fuel contributes positively to the global green agenda, it deteriorates the quality of the local environment. The project pollutes the local environment which is a source of livelihood for the local people and the economy. Therefore, the adverse effect of the project on the local environment contributes to a negative effect on the local economy and livelihood of the residents. The results also revealed that the project stakeholders, particularly the residents of Cradock and the emerging farmers, were not involved in the early stages of the project where the benefits were determined. As a result, the stakeholders do not have a sense of ownership of the project, and there are uncertainties about the sustainability of their socio-economic benefits. The ethanol project introduces a shift from the traditional commercial agriculture to the production of biofuel feedstock. This causes an effect on the local economy and livelihood because traditional commercial agriculture has sustained the town for more than 200 years. The thesis raises questions about the notion that ethanol projects are green economic models.

The production of ethanol and other sustainable products including methane, limonene and pectin from citrus wastes (CWs) was studied in the present thesis. In the first part of the work, the CWs were hydrolyzed using enzymes – pectinase, cellulase and β-glucosidase – and the hydrolyzate was fermented using encapsulated yeasts in the presence of the inhibitor compound ‘limonene’. However, the application of encapsulated cells may be hampered by the high price of encapsulation, enzymes and the low stability of capsules’ membrane at high shear stresses. Therefore, a process based on dilute-acid hydrolysis of CWs was developed. The limonene of the CWs was effectively removed through flashing of the hydrolyzate into an expansion tank. The sugars present in the hydrolyzate were converted to ethanol using a flocculating yeast strain. Then ethanol was distilled and the stillage and the remaining solid materials of the hydrolyzed CWs were anaerobically digested to obtain methane. The soluble pectin content of hydrolyzate can be precipitated using the produced ethanol. One ton of CWs with 20% dry weight resulted in 39.64 l ethanol, 45 m3 methane, 8.9 l limonene, and 38.8 kg pectin. The feasibility of the process depends on the transportation cost and the capacity of CW. For example, the total cost of ethanol with a capacity of 100,000 tons CW/year was 0.91 USD/L, assuming 10 USD/ton handling and transportation cost of CW to the plant. Changing the plant capacity from 25,000 to 400,000 tons CW per year results in reducing ethanol costs from 2.55 to 0.46 USD/L in an economically feasible process. Since this process employs a flocculating yeast strain, the major concern in design of the bioreactor is the sedimentation of yeast flocs. The size of flocs is a function of sugar concentration, time and flow. A CFD model of bioreactor was developed to predict the sedimentation of flocs and the effect of flow on distribution of flocs. The CFD model predicted that the flocs sediment when they are larger than 180 micrometer. The developed CFD model can be used in design and scale-up of the bioreactor. For the plants with low CW capacity, a steam explosion process was employed to eliminate limonene and the treated CW was used in a digestion plant to produce methane. The required cost of this pretreatment was about 0.90 million dollars for 10,000 tons/year of CWs. / <p><strong>Sponsorship</strong>:</p><p>Sparbankstiftelsen Sjuhärad, Kommunalförbundet i Sjuhärad, Brämhults juice AB</p>

Published Article / The growth of Saccharomyces cerevisiae strain W303-1A(a) was evaluated in complex and chemically defined media. The use of chemically defined medium allowed the complete utilisation of glucose within 20 h. as well as all of the produced ethanol within 45 h. Maximum specific growth rates (µmax) were increased from 0.28 h-1 to 0.42 h-1 and the volumetric rate of ethanol production increased from 0.204 g l-1 h-1 to 0.597 g l-1 h-1. However, when the ethanol concentration exceeded a threshold value of 10 g l-1, the µmax value was significantly decreased. These observations suggest that ethanol metabolism related growth experiments for the relevant strain should be carried out in chemically defined medium with ethanol concentrations below 10 g l-1.

Research project submitted in fulfillment of the academic requirements for the Masters Degree in Technology: Chemical Engineering, Durban University of Technology, 2010. / Globally there is renewed interest in the production of alternate fuels in the form of bioethanol and biodiesel. This is mainly due to the realization that crude oil stocks are limited hence the swing towards more renewable sources of energy. Bioethanol and biodiesel have received increasing attention as excellent alternative fuels and have virtually limitless potential for growth. One of the key processing challenges in the manufacturing of biofuels is the production of high purity products. As bioethanol is the part of biofuels, the main challenge facing bioethanol production is the separation of high purity ethanol. The separation of ethanol from water is difficult because of the existence of an azeotrope in the mixture. However, the separation of the ethanol/water azeotropic system could be achieved by the addition of a suitable solvent, which influences the activity coefficient, relative volatility, flux and the separation factor or by physical separation based on molecular size. In this study, two methods of high purity ethanol separation are investigated: extractive distillation and pervaporation. The objective of this project was to optimize and compare the performance of pervaporation and extraction distillation in order to produce high purity ethanol. The scopes of the investigation include:  Study of effect of various parameters (i) operating pressure, (ii) operating temperature, and (iii) feed composition on the separation of ethanol-water system using pervaporation.  Study the effect of using salt as a separating agent and the operating pressure in the extractive distillation process. The pervaporation unit using a composite flat sheet membrane (hydrophilic membrane) produced a high purity ethanol, and also achieved an increase in water flux with increasing pressure and feed temperature. The pervaporation unit facilitated separation beyond the ethanol – water system azeotropic point. It is concluded that varying the feed temperature and the operating pressure, the performance of the pervaporation membrane can be optimised. v The extractive distillation study using salt as an extractive agent was performed using the low pressure vapour-liquid equilibrium (LPVLE) still, which was developed by (Raal and Mühlbauer, 1998) and later modified by (Joseph et al. 2001). The VLE study indicated an increase in relative volatility with increase in salt concentration and increase in pressure operating pressure. Salt concentration at 0.2 g/ml and 0.3 g/ml showed complete elimination of the azeotrope in ethanol-water system. The experimental VLE data were regressed using the combined method and Gibbs excess energy models, particular Wilson and NRTL. Both models have shown the best fit for the ethanol/water system with average absolute deviation (AAD) below 0.005. The VLE data were subjected to consistency test and according to the Point test, were of high consistency with average absolute deviations between experimental and calculated vapour composition below 0.005. Both extractive distillation using salt as an extractive agent and pervaporation are potential technologies that could be utilized for the production of high purity ethanol in boiethanol-production.

Due to their ability to simultaneously reduce fuel consumption and NOx emissions, Controlled Auto Ignition (CAI) and HCCI combustion processes have been extensively researched over the last decade and adopted on prototype gasoline engines. These combustion processes were initially achieved on conventional two-stroke ported gasoline engines, but there have been significantly fewer studies carried out on the CAI combustion in two-stroke engines. This is primarily due to the inherent problems associated with conventional two-stroke engine intake and exhaust ports. Meanwhile, engine downsizing has been actively researched and developed as an effective means to improve the vehicle’s fuel economy. This is achieved by operating the engine at higher load regions of lower fuel consumption and by reducing the number of cylinders. However, aggressive downsizing of the current 4-stroke gasoline engine is limited by the knocking combustion and high peak cylinder pressure. As an alternative approach to engine downsizing, boosted two-stroke operation is being researched. In this thesis, it has been shown that the CAI combustion in the two-stroke cycle could be readily achieved at part-load conditions with significant reductions in CO and uHC emissions when compared to typical SI combustion in a single cylinder gasoline direct injection camless engine. In addition, extensive engine experiments have been performed to determine the optimum boosting for minimum fuel consumption during the two-stroke operation. In order to minimise the air short-circuiting rate, the intake and exhaust valve timings were varied and optimised. It is shown that the lean operation under boosted condition can extend the range of CAI combustion and increase combustion and thermal efficiencies as well as producing much lower CO and HC emissions. By means of the cycle-resolved in-cylinder measurements and heat release analysis, the improvement in combustion and thermal efficiencies were attributed to the improved in-cylinder mixture, optimised autoignition, and combustion phases. Finally, in view of the increased use of ethanol in gasoline engines, E15 and E85 were used and their effect on engine performance, fuel economy and exhaust emissions were investigated.

Cocaine- and amphetamine-regulated transcript (CART), as its name implies, was initially identified as an upregulated transcript in response to psychostimulant administration. Consequently, it has been posited to play a role in psychostimulant abuse and dependence. Spurred on by the finding that a polymorphism in the CART gene was associated with alcoholism, we initiated studies designed to elucidate the role of CART peptide in alcohol dependence. We first investigated the functional significance of CART peptide in alcohol dependence in vivo using a CART KO mouse. We found that CART KO mice had a significant decrease in ethanol consumption that could not be attributed to differences in total intake, taste perception, metabolism, or sensitivity to ethanol. In vitro we found that CART peptide facilitated NMDA receptor-mediated currents in central amygdala neurons. Given the emerging role of CART peptide in anxiety and stress, we decided to examine basal and stress-induced anxiety behaviors in CART KO mice. Under basal and acute stress conditions, CART KO mice did not differ in anxiety-like behaviors from WT mice; however, in response to a stressor, CART KO mice exhibited a potentiated corticosterone response. Using chronic intermittent ethanol exposure (CIE), we tested CART KO and WT mice for common signs of ethanol dependence including an escalation of volitional consumption and the presence of withdrawal-induced anxiety. We further investigated glutamatergic neuroadaptations within the central amygdala of CART KO and WT mice following CIE exposure and early withdrawal. CIE increased ethanol consumption and anxiety-like behaviors in mice of both genotypes but to a lower extent in CART KO mice. Electrophysiologically, CIE enhanced spontaneous excitatory postsynaptic currents in both genotypes and decreased the probability of presynaptic release in WT mice only. We believe that these electrophysiological neuroadaptations contribute to the development of ethanol dependence and may mediate withdrawal-induced anxiety behaviors. Overall, these studies indicate a role for CART peptide in alcohol dependence and specifically in modulating ethanol withdrawal-induced anxiety. / text

The fields of biodiesel and bioethanol research and development have largely developed independently of one another. Opportunities exist for greater integration of these processes that may result in decreased costs of production for both fuels.To that end, this work addresses the use of the starches and glycerol from processed algal biomass as substrates for fermentation by the yeasts <ital>Saccharomyces cerevisiae</ital> and <ital>Pachysolen tannophilus,</ital> respectively. Ethanol producers commonly employ the former yeast for ethanol production and include the latter yeast among candidate species for cellulosic ethanol production.A simple 95% ethanol extraction at 70°C followed by sulfuric acid hydrolysis at 121°C and 2 atm proved a sufficient pretreatment for <ital>S. cerevisiae</ital> fermentation of starch from <ital>Chlamydomonas reinhardtii</ital> mutant <ital>cw15.</ital> The maximum rate of ethanol production was observed as 14 mL/g-h and a maximum concentration of 0.9±0.01% (m/v) was observed by 28 hours. Some starch appeared invulnerable to hydrolysis.<ital>P. tannophilus</ital> fermentation of glycerol, both independently and among mixed substrates, was likewise demonstrated. It was found that glucose consumption preceded that of glycerol and xylose, but that the latter two substrates were consumed concurrently. Under aerobic, batch conditions, the maximum specific growth rate of the species on a 2% glycerol substrate was observed as 0.04/hr and the yield coefficient for conversion of glycerol to ethanol was 0.07 g/g. While the maximum observed concentration of ethanol in the glycerol-only fermentation was 0.1% m/v, that in mixed media containing 2% each glucose, xylose, and glycerol was 1.5%.Also investigated here was the flocculation of a mutant species of the algae <ital>C. reinhardtii</ital> by a combination of methanol and calcium. Algae harvest is typically an energy-intensive process, but the technique demonstrated here is not. Complete flocculation of cells was observed with only 5 minutes of mixing and less than 10 minutes of settling using 12 mM CaCl₂ and 4.6% methanol. Ethanol was observed to operate in the same capacity, intimating another area in which yeast bioethanol and algal biodiesel processes might enable one another. During growth, either an inhibitor of flocculation was produced or a facilitator was consumed.

No description available.

Oxycodone is a semi-synthetic opioid originally developed as a safer alternative to morphine. It is commonly prescribed for its pain-relieving effects, but has recently been implicated as a major underlying cause of the current opioid epidemic due to its clinical limitations that include tolerance, dependence and a high abuse liability. Simultaneous consumption of opioids and ethanol has been shown to increase the risk of overdose and death from opioids in opioid-tolerant individuals. We hypothesized that ethanol reversed opioid tolerance and previous studies showed that ethanol reversed morphine tolerance. This dissertation investigated whether ethanol reversed tolerance to other opioids in mice, primarily oxycodone. We found that tolerance developed to the antinociceptive effects of both oxycodone and hydrocodone, and that the same dose of ethanol (1 g/kg i.p.) reversed that tolerance. Oral ethanol (2 g/kg) also effectively reversed oxycodone tolerance. Ethanol did not significantly alter either acute or chronic oxycodone brain concentrations, suggesting that the reversal effect was mediated by neuronal mechanisms. DRG neurons were isolated from adult mice and the effects of oxycodone were assessed using whole-cell patch clamp electrophysiology experiments. Oxycodone [3µM] acutely reduced neuronal excitability as measured by a shift in threshold potentials to a more positive value. DRG neurons incubated overnight with 10µM oxycodone did not respond to the 3µM oxycodone challenge, indicating tolerance developed within these neurons. To test if ethanol was reversing tolerance through neuronal mechanisms, we incubated DRG neurons overnight with 10µM oxycodone and applied 20mM ethanol to the media prior to recording. Tolerance was robustly reversed in these neurons, as indicated by a response to 3µM oxycodone. The PKC inhibitor, Bis XI, also reversed oxycodone tolerance. In these studies we have clearly shown that tolerance develops to oxycodone in both the whole animal in an isolated neuronal preparation. In addition we have shown that the tolerance produced in these two preparations was reversed by ethanol at blood levels similar to those seen in humans. Further we have also included preliminary data that suggest that this reversal of oxycodone tolerance by ethanol may well be due to its actions on PKC.