The constantly growing demand for energy and the consequent depletion of fossil fuels have led to a drive for energy that is environmentally friendly, efficient and sustainable. A viable source with the most potential of adhering to the criteria is nuclear-produced hydrogen. The hybrid sulphur cycle (HyS) is the proposed electrothermochemical process that can produce the energy carrier, hydrogen. The HyS consists of two unit operations, namely the electrolyzer and the decomposition reactor, that decomposes water into hydrogen and oxygen. A techno-economic evaluation of the technology is needed to prove the commercial potential of the cycle. This research project focuses on determining the hybrid sulphur cycle’s recommended operating parameter range that will support economic viability whilst maintaining a high efficiency. This is done by comparing the results of an evaluation of four case studies, all operating under different conditions. The technical evaluation of the research project is executed using the engineering tool Aspen PlusTM. The models used to achieve accurate results were OLI Mixed Solvent Electrolyte, oleum data package for use with Aspen PlusTM, which provides an accurate representation of the H2SO4 properties, and ELECNRTL to provide an accurate representation of H2SO4 at high temperature conditions. This evaluation provides insight into the efficiency of the process as well as the operating conditions that deliver the highest efficiency. The economic evaluation of the research project determines the hydrogen production costs for various operating conditions. These evaluations provide a recommended operating parameter range for the HyS to obtain high efficiency and economic viability. / Thesis (M.Ing. (Nuclear Engineering))--North-West University, Potchefstroom Campus, 2010.

The performance of a submerged membrane bioreactor for the duty of gas field produced water treatment was appraised. The system was operated under steady state conditions at a range of mixed liquor suspended solids (MLSS) concentrations and treatment and membrane performance examined. Organics removal (COD and TOC) display removal rates between 90 and 97%. Removal of specific target compounds Benzene, Toulene, Ethylbenzene and Xylene were removed to above 99% in liquid phase with loss to atmosphere between 0.3 and 1%. Comparison of fouling rates at a number of imposed fluxes has been made between long term filtration trials and short term tests using the flux step method. Produced water fed biomass displays a greater fouling propensity than municipal wastewater fed biomass from previous studies. Results indicate an exponential relationship between fouling rate and flux for both long and short term trials, although the value was an order of magnitude lower during long term tests. Moreover, operation during long term trials is characterised by a period of pseudo stable operation followed by a catastrophic rise in TMP at a given critical filtration time (tfi, ) during trials at 6 g. L"1. This time of stable operation, tfit, is characterised by a linear relationship between fouling rate and flux. Results have been compared with the literature. Data for membrane fouling prior to the end of t fit yielded a poor fit with a recently proposed model. Trends recorded at t> trlt revealed the fouling rate to follow no definable trend with flux. The system showed resilience to free oil shocking up to an oil concentration of 200ppmv. Following an increase in oil concentration to 500 ppmv, rapid and exponential fouling ensued.

Made available in DSpace on 2014-06-11T19:29:14Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-05-28Bitstream added on 2014-06-13T20:59:30Z : No. of bitstreams: 1 mattos_mcc_me_botfmvz.pdf: 2029467 bytes, checksum: 940e4724967df5043139371eecb13c64 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Objetivou-se com o presente estudo avaliar a criotorerância de mórulas e blastocistos produzidos in vivo de doadoras da raça Sindi e Nelore (Bos indicus) e Holandês Preto e Branco (HPB - Bos taurus). No Experimento 1, 24 fêmeas lactantes e não lactantes da raça Sindi foram superovuladas com 100 mg de FSH suíno com protocolos em que as duas últimas aplicações de FSH foram substituídas ou não por 300 UI de eCG. Sete dias após a indução da ovulação, os embriões foram colhidos e avaliados quanto ao estágio de desenvolvimento embrionário e grau de qualidade. Dois terços dos embriões foram destinados à criopreservação, dos quais metade foi congelada pelo método convencional, com curva de resfriamento de –0,5ºC/min e a outra metade foi vitrificada pela técnica de Cryotop. Em seguida, foram descongelados e transferidos para receptoras sincronizadas, de maneira contemporânea aos embriões frescos. No Experimento 2, 31 fêmeas da raça Nelore foram superovuladas com 133 mg de FSH suíno e os dois terços dos embriões colhidos foram criopreservados e transferidos semelhantemente ao Experimento 1. No Experimento 3, 67 vacas lactantes e novilhas da raça HPB foram superovuladas com 500 e 300 UI de FSH suíno, respectivamente, e após a colheita dos embriões foram adotados os mesmos procedimentos realizados nos Experimentos 1 e 2. Os resultados foram analisados por modelos lineares generalizados e estão apresentados na forma de média dos quadrados mínimos ± erro padrão. Nos Experimentos 1 e 2, os embriões transferidos a fresco apresentaram maior taxa de concepção aos 30 dias do que os vitrificados e congelados (54,8±7,4a, 17,7±7,3b e 19,5±6,6%b; respectivamente; P 0,0013) na raça Sindi (n=231 embriões) e (46,0±6,1a; 31,2±5,4b e 28,1±5,3%b; respectivamente, P 0,04) na raça Nelore (n=297 embriões). O estágio de desenvolvimento embrionário parece não... / The aim of this study was to evaluate the cryotolerance of morulae and blastocysts produced in vivo in Sindhi and Nelore (Bos indicus) and Holstein (Bos taurus) donnors. In Experiment 1, 24 lactating and non-lactating Sindhi donnors were superovulated with 100 mg porcine FSH with protocols in which the last two FSH treatments were replaced or not by 300 IU eCG. Embryos were collected 7 days after ovulation induction and embryo development and quality degree were accessed. Two thirds of the embryos were cryopreserved, by the conventional freezing or Cryotop method. After that, embryos were thawed and transferred to synchronized recipients, simultaneously to fresh embryos. In Experiment 2, 31 Nelore cows were superovulated with 133 mg porcine FSH and two thirds of the embryos were cryopreserved and transferred similarly to Experiment 1. In Experiment 3, 67 Holstein lactating dairy cows and heifers were superovulated with 500 and 300 IU pFSH, respectively, and the same procedures were performed as in Experiments 1 and 2. Results were analyzed using generalized linear models and are presented as least squares means ± standard error. In Experiments 1 and 2, fresh embryos had a higher conception rate at Day 30 than those vitrified and frozen (54.8±7.4a, 17.7±7.3b and 19.5±6.6%b; respectively; P 0.0013) in Sindhi donnors (n=231 embryos) and (46.0±6.1a; 31.2±5.4b and 28.1±5.3%b; respectively; P 0.04) in Nelore donors (n = 297 embryos). Embryo developmental stage seems to have not influenced conception rates of Zebu embryos, especially cryopreserved ones. Finnaly, in Experiment 3, conception rates of fresh and cryopreserved embryos were similar (37.4±12.3, 24.5±11.3 and 21.0±9.5%; respectively, P>0.15) and also no difference was detected for the cryotolerance of morulae versus blastocysts (P>0.10)

Produced water (PW), or water associated with crude oil extraction, is the largest oily wastewater stream generated worldwide. The reuse and reclamation of these important water volumes are critical for more sustainable operation in the oilfield. Ceramic membrane filtration is a promising technology for PW treatment; however, fouling is the major drawback for a broader application. Fouling leads to higher resistance to flow, reducing membrane lifetime, and ultimately leading to higher capital expenditures and operating expenses. Further understanding of the interactions between PW foulants and the ceramic materials is needed for designing fouling control strategies and cleaning protocols for ceramic membranes. This work explored different techniques to characterize, visualize, and quantify the submicron PW contaminants content and its adsorption interactions with metal oxides. We visualized and characterized submicron oil droplets in oilfield PW samples by applying suitable advanced microscopy techniques. For the first time, crude oil droplets as small as 20 nm were found in oilfield PW together with other submicron contaminants. The adsorption studies performed by quartz crystal microbalance with dissipation (QCM-D) showed that the interactions of organic surface-active compounds with the metal oxides are driven by the nature of the surfactant and not by the surface properties. This has implications in the selection of the ceramic membrane material, wherein electrostatic interactions should not be taken as the only predicting factor of adsorption and fouling during PW treatment. Furthermore, our results suggested that the more fluid or viscoelastic-like the contaminant layer, the more difficult the cleaning process from the metal oxide. It demonstrates that the mechanical property of the attached films is a crucial factor in designing appropriate cleaning protocols for ceramic membranes. Finally, QCM-D and advanced microscopy techniques were applied to analyze adsorption and cleaning of contaminants in a complex Bahraini PW into alumina as a case study. Bacteria were found to attach irreversibly on the alumina surface, promoting nucleation points for calcium precipitates. The protocols developed in this work are suitable for understanding membrane fouling phenomena in the micron scale and could be implemented before filtration pilot testing to save time and expenses at larger scales.

The Women's Revolution in 2015 has led to a drastic shift in the ways women are portrayed in professional wrestling. The Women's Revolution came as a result of the social unrest over the lack of time women were receiving on the televised shows. Where women's storylines had centered on their sexuality, they are now presented as equal to their male counterparts after the Women's Revolution. Through an exploration of concepts in globalization, commodification, and socially produced spaces, this research seeks to understand and contextualize the Women's Revolution, the degree to which the portrayed women's equality has been achieved, and the resulting impacts of the female superstars overall. I argue that that this "equality" has been achieved through inscribing the traditionally masculine qualities of wrestling to women, has resulted in an unequal distribution of opportunities to particular female superstars rather than equality for all women on the shows, and that phallocentric objectification of the female superstars still occurs in certain aspects of professional wrestling.

The simultaneous treatment of different produced water streams with the forward osmosis membrane distillation hybrid system (FO-MD) has been suggested recently. This work investigates the need for pretreatment of produced water prior to filtration with FO-MD in order to reduce the level of fouling and scaling in the system. The desalter effluent (DE) stream was selected as FO feed solution, and the water oil separator (WO) stream was used as FO draw solution/MD feed solution, and a significant flux decline was observed in FO and MD within the first 5 hours of operations. SEM and EDX analysis indicated that the formation of scale layer on both membranes was the main reason for the sharp flux decline. Silica was the major contributor to the scaling of the support layer of the FO membrane. While the scaling layer on MD membrane consisted mainly of CaSO4 crystals with some deposition of Silica. Therefore, electrocoagulation (EC) was selected for the pretreatment of produced water to target the removal of Ca, SiO2 and SO4 ions in order to reduce the likelihood of inorganic fouling in FO-MD. The different parameters of EC, namely, the current density, electrolysis time, and initial pH were tested at a wide range of values of 7-70 mA/cm2 , 10-60 minutes, 5-9, respectively. calcium and sulfate ions were not effectively removed at the relatively high applied current density of 70 mA/cm2 , while high removal of silica was achieved even at low applied current densities. The optimum conditions of EC for silica removal were found to be 7 mA/cm2 for the current density and 10 minutes for the electrolysis time which resulted in a 97% removal of silica. it was found that due to pretreatment, the average FO and MD fluxes increased by 49% (9.93 LMH) and 39% (8.55 LMH), respectively. Therefore, even though EC did not show promising results in terms of the removal of calcium and sulfate, efficient silica removal was achieved with minimum energy requirements which suggests that it could have a potential to be integrated with the FO-MD hybrid system for the treatment and reclamation of produced water.

Aqueous industrial effluents containing organic pollutants, such as textile dyes and crude oil, represent environmental and human health concerns due to their toxicity and possible carcinogenic effects. Adsorption is the most promising wastewater treatment method due to its efficiency, ease of operation, and low cost. However, currently used adsorbents have either high regeneration costs or low adsorption capacities. In this work, new organic/inorganic hybrids based on hollow silica microspheres were successfully synthesized, and their ability to remove Methylene Blue from wastewater and crude oil from simulated produced water was evaluated. By employing four different silanes, namely triethoxy (octyl) silane, triethoxy (dodecyl) silane, trichloro (octadecyl) silane, and triethoxy (pentafluorophenyl) silane, hydro and fluorocarbons were grafted onto the surface of commercially available silica microspheres. These silica derivatives were tested as adsorbents by exposing them to Methylene Blue aqueous solutions and synthetic produced water. Absorbance and oil concentration were measured via a UV/Vis Spectrophotometer and an HD-1000 Oil-in-Water Analyzer respectively. Methylene Blue uptake experiments showed that increasing the adsorbent dosage and decreasing initial dye concentration might increase adsorption percentage. On the other hand, adsorption capacities were improved with lower adsorbent dosages and higher initial dye concentrations. Varying the initial solution pH, from pH 5 to pH 9, and increasing ionic strength did not seem to have a significant impact on the extent of adsorption of Methylene Blue. Overall, the silica derivative containing aromatic functional groups, Caro, was proven to be the most effective adsorbent due to the presence of π-π and cation-π interactions in addition to the van der Waals and hydrophobic interactions occurring with all four adsorbents. Although the Langmuir Model did not accurately represent the equilibrium data, it produced consistent maximum adsorption values and adsorption equilibrium constants. Preliminary experiments demonstrated the potential to recover and reuse the silica microspheres by washing with NaOH and organic solvents. The preferential adsorption of oil micro-droplets onto the surface of functionalized hollow silica microspheres was evidenced. However, preparing synthetic produced water that was stable enough to carry out kinetics experiments remained a challenge.

These studies investigated the effects of retinoic Acid (RA) on angiogenesis. Three human, neoplastic cell lines were used to examine angiogenic promotion and/or inhibition. The cell lines, U-373MG glioblastoma, DU-145 prostate carcinoma, and TCCSUP bladder transitional cell carcinoma, were treated with the following: all-trans, 9-cis, or 13-cis RA, at doses from 0.0001 to 100 μM. Hpoxia was used to assist the expression of the angiogenic phenotype. Conditioned media (CM) were prepared by growing the tumor cells in the presence of RA and hypoxia for 24 hours, and then the CM was transferred to bovine, capillary endothelial cells (EC) for 48 hours. The EC were counted for each CM and compared to controls. Multiplex, reverse transcriptase-polymerase chain reaction (MRT-PCR) was used on tumor cell RNA to demonstrate that mRNA expression of several angiogenic growth factors was modified. Angiogenic proteins in the CM were identified by enzyme-linked immunosorbent assay (ELISA). The CM from the U-373 and DU-145 cells, but not the TCCSUP cells, treated with all-trans or 9-cis RA caused significant increases (P<0.05) in EC proliferation. RA in nonconditioned media inhibited EC proliferation. CM treated with 13-cis RA did not increase EC proliferation. MRT-PCR demonstrated that the tumor cells expressed vascular endothelial growth factor (VEGF), midkine, interleukin-8 (IL-8), thrombospondin (TSP), and leukemia inhibitory factor (LIF) mRNAs. Increases VEGF mRNA corresponded to increase EC proliferation. IL-8 mRNA increased at RA concentrations greater than 0.1 μM. Midkine mRNA concentrations were generally unaffected by RA treatments. ELISA demonstrated that VEGF was increased by all-trans RA, to a lesser degree by 9-cis, and even less by 13-cis. IL-8 protein secretion was inhibited by RA. The expression of TSP and LIF mRNAs was almost completely inhibited by hypoxia. EC were grown with sodium heparin at 0, 10, 100, 500, or 1000 μg/ml in CM produced with DU-145 cells and 0.0001, 0.001, or 1 μM all-trans RA. Heparin increased EC proliferation at 10 μg ml and inhibited proliferation at higher concentrations.

This thesis engages with sustainable cultural heritage by considering how user-produced maps may reveal new knowledge about heritage values. Through interrogating whether authorized heritage values and unauthorized heritage values are aligned, as manifested in cartographical sources, by taking the World Heritage city of Visby, Sweden as a case study. The thesis will use primary source maps produced by users and compare them to sites of authorized heritage values to determine if, and where, new and divergent heritage values may appear. By considering a bottom-up approach to cultural heritage valuation, as well as supporting the preservation of user heritage values, this thesis contributes how to sustainably plan for cultural heritage from both a social and physical perspective.            The findings from the study reveal how heritage is functioning within the city of Visby, and the larger Gotland Island, to both reenforce authorized values, as well as portray new sites of heritage values. A major feature of Visby and Gotland has to do with its many periods of heritagization, which have created a phenomenon described by the user-produced maps as several heritages existing together in a singular geographical location. The user-produced maps are therefore proved to be exceptionally rich sources for user values and trends related to heritage, and should be considered for digital preservation for scholars, learners and those preserving heritage environments into the future. This study demonstrates the usefulness of user-produced maps as primary sources, and highlights key ways in which authorized heritages may be limiting to user contributions. Therefore, initiatives to encourage users to continue to create maps related to their heritage values should be encouraged. The creation of digital maps by users has limitless potential to enrich, portray, and preserve the lived heritage realities of the users, supplementing the authorized heritage values already established.

Bovine in vitro produced embryos suffer from poor developmental competence and altered metabolism which hinders their cryotolerance. Overall, the goals of this thesis were to improve oocyte and embryo culture with the antioxidant polydatin and to optimize slow freezing procedures. This thesis was designed as three experiments, and in each experiment, oocytes were aspirated from abattoir ovaries, matured for 23h, fertilized with semen from 1 of 3 bulls, and cultured in synthetic oviductal (SOF) based medium (SCF1) in 38.5 °C in 5% O2, 5% CO2 and 90% N2. Stage 7 blastocysts were stained with Nile Red for lipid content or Mitotracker Red CMX-Rosamine for mitochondrial activity or Cell Rox Green for reactive oxygen species. Ten images per embryo were acquired using confocal microscopy at 5-µM step size and detected fluorescence by IMAGE PRO software. Embryos were also slow frozen in ethylene glycol and analyzed for post-thaw re-expansion after 24 and 48 hours. Experiment one was a 2x2x2 factorial design to test two culture media (SCF1 and a conventional SOF media), the use of a sucrose dehydration prior to slow freezing (2 min in 0 or 0.6 sucrose), and the length of equilibration in ethylene glycol prior to slow freezing (10 or 20 min). We determined that embryos cultured in SCF1 had increased blastocyst rate, mitochondrial activity, and cryotolerance and decreased lipid accumulation (pin vitro.