Submitted in fulfilment of the academic requirements for the Degree of Masters in Technology: Chemical Engineering, M.L. Sultan Technikon, 2002. / Crossflow microfiltration (CFMF) using a fabric support has been successfully used to treat a range of problematic waters. Experimental evidence indicates that the formation of a dynamic membrane or precoat on a woven-fibre microfilter can significantly increase the performance of the filter, that is, the production rate and rejection. The use of precoats in filtration applications is based on the precoat's unique microstructure that is able to trap sub-micron particles while maintaining a permeable filter cake. However, to date the precoating step has been more of an art than a science. Very little knowledge exists on the best type of precoat to use, or the the optimal velocity, pressure and concentration to form a stable precoat. Further, although various models have been proposed for CFMF, their still exists a lack of knowledge of the mechanisms by which precoats improve performance. / M

Submitted in fulfilment of the academic requirements of Masters in Applied Sciences (Chemistry), Durban University of Technology, 2017. / This thesis forms part of the Durban University of Technology Thermodynamics Research Unit’s project which is aimed at developing a method for determination of the liquid-liquid equilibria (LLE) data for the azeotrope {methanol + water} with an ionic-liquid (IL) using DSA5000M to assess the efficiency of the ionic liquid to be used in liquid-liquid extractions for the recovery and recycling of methanol from petroleum refinery. The objective of this study was to determine the liquid-liquid equilibria data of the azeotrope {methanol + water} using 1-ethyl-3-methylimidazolium ethyl sulfate ionic liquid with the intention to recycle methanol from the Fischer-Tropsch (FT) process by- products in petroleum industries and to utilize it in gasoline additives in a new methanol to gasoline (MTG) petroleum process. LLE studies of systems containing alcohols and water are important due to the increasing demands of oxygenated compounds to produce lead free gasoline. Light alkanols such as methanol and ethanol are reported to be suitable compounds in order to produce lead free gasoline, but the use of methanol in gasoline blends can cause phase separation problems in: 1. dry conditions, these are due to its partial solubility in saturated hydrocarbons. 2. the presence of water from ambient humidity or in storage tanks, this depend on unfavourable distribution factor between aqueous and the hydrocarbon phase. To determine the possibility of separating methanol from water using ionic liquid, the liquid-liquid equilibria data was determined at room temperature, T = 298.15 K and atmospheric pressure to investigate whether it separate from water and/or a non-phase separation if it is used as an additive. The experimental data generated was compared to that of the literature for the system {methanol (1) +toluene (2) + dodecane (3)} and showed good agreement with the literature data with only maximum deviation of ± 0.0015 in the mole fraction using density calculations and ± 0.0092 in the mole fraction when using refractive index calculations The selectivities and distribution coefficients for this system were also calculated and the maximum deviation between the two methods (nD and ρ) was ± 1.33 in selectivities and found to be ±0.001 for distribution coefficients. The maximum deviation in distribution coefficients from literature when using nD calculations for system 1 was ±0.04 and ±0.01 for ρ. For the selectivity values the deviation from that of literature of nD when compared was found to be ± 1.28 and 0.29 for ρ respectively. The selectivity values from the density calculations were found to be in the range 2.82 – 7.66 for this system with the distribution coefficient values reported in the range 0.17 – 0.23. In the second system (system 2) the generated experimental data was also compared to that of the literature for the system {water (1) + methanol (2) + cyclohexane (3)} and in good agreement with literature values with only maximum deviation of ± 0.0091 in the weight fraction based on density calculations. The selectivities and distribution coefficients were also calculated and the maximum deviation between the literature and the experimental data was computed to be at ± 0.0003 for selectivity and ±0.09 in distribution coefficient. The selectivity values were found to be in a range 0.00 - 0.04 for this system and were constant throughout the phases but significantly less than one; with the distribution coefficient values in the range 0.00 – 0.008. For 1-ethyl-3-methylimidazolium ethyl sulfate system (Ionic liquid system) the selectivity values were not constant throughout the two-phase region and the values were found to be in the range 0.63 -0.99 still below one which indicates that the ionic liquid used in this study could not be considered as a potential solvent for the separation of the investigated azeotrope. The distribution coefficients for this system were determined and found to be in the range 0.23 – 0.74. The certainty and reliability of experimentally measured tie-line data was ascertained by applying Othmer-Tobias (OT) correlations and the Non-Random, Two Liquid (NRTL) parameters. The OT correlations for system 1 was linear and indicated the certainty of the five tie-lines prepared for this system. In system 2 the OT correlation was not linear and indicated extensively high errors as well as high systematic multiplicative and additive errors in calculations of mole fractions. For the IL system the OT correlation was linear throughout the whole tie-line range and indicated the adequate precision, which denotes that the investigation was carried out with minimal random and systematic errors and indicated the efficiency of the DSA 5000 M to generate the liquid-liquid equilibria data. All the ternary systems were well correlated and in good agreement with the estimated NRTL data. It was only system 1{methanol (1) + toluene (2) + dodecane (3)} that gave a high maximum deviation ( %RSMD) of 1.288 when using the RI measurements with the minimum error margin of 0.6320, this account as to why RI measurements were not applied in other systems (system 2 and ionic liquid system). Similarly for the same system; system 1{methanol (1) + toluene (2) + dodecane (3)} when using the density measurements; the NRTL model gave a maximum deviation of 0.5620 and minimum error margin of 0.2590. The NRTL obtained for system 2 {water (1) + methanol (2) + cyclohexane (3)} gave the maximum deviation of 0.5752 and minimum error margin of 0.0127. The NRTL for the ionic liquid ternary system {[EMIM][EtSO4](1) + methanol (2) + water (3)}showed a good agreement between the experimental data and the NRTL model tie- line data with the %RSMD of 1.0201 on the upper limit and 0.1620 as a lower deviation. / M

Close relationships play an integral role in human health (Coan & Sbarra, 2015). It follows, then, that the dissolution of an important relationship can have a variety of negative health consequences (Amato, 2010; Kitson & Morgan, 1990; Sbarra, Law, & Portley, 2011), and social loss confers vulnerability to a range of morbidities and early mortality. Disrupted marital status is one of the strongest sociodemographic predictors of stress-induced physical illness (Somers, 1979) and marital disruption has long been reported as one of life's most stressful events (Bloom, Asher, & White, 1978). Robust evidence links divorce or separation to poorer health outcomes; however, the exact mechanisms through which relationship dissolution influences our health so profoundly are not yet fully elucidated (Sbarra, Hasselmo, & Bourassa, 2015). The current study investigated how changes in psychological responses to divorce are associated with changes in immune responding in recently-separated adults (N = 55). I followed participants over an average of five months, collecting psychological distress measures at three visits, each one month apart, and immune measures at two visits, five months apart. To assess how variability in social engagement is associated with immunological responses following the end of a marriage, I incorporated naturalistic, observational data using a new methodology. I found that an objectively derived composite of social behaviors including (a) time spent with others; (b) time spent socializing/entertaining; (c) time spent in substantive conversation; and (d) time spent receiving positive support predicted concurrent immune outcomes over and above the effects of psychological distress and/or loneliness, and that psychological distress may exert indirect influence on immune outcomes through social integration. Furthermore, attachment style revealed differential longitudinal associations between social integration and immune outcomes. This research expands current knowledge on the immune-relevant outcomes of divorce and separation, and includes new methodology for naturalistically-derived measures of social engagement in determining how this common life stressor is associated with health over time.

M. Tech. / The separation of minerals such as coal, diamonds and others have involved the use of a heavy medium. The heavy medium separation technique, used in the diamond industry as a primary concentrator, is a physical process that separates minerals of different specific densities based on their relative movement and resistance to motion in a viscous fluid. It is made up of a suspension of finely ground solid particles constituting a stable suspension. There is a wide range of materials that are used to prepare suspension media in Heavy Medium Separation (HMS), but Ferrosilicon has found a wider usage. Major demand for dense medium Ferrosilicon powder is from the diamond industry which accounts for 77 percent of milled sales. In HMS, either dynamic or static separators can be used, even though; dynamic separators are widely used because they give higher separation efficiencies. A number of accounts have been reported on the effects of stability and viscosity to the medium. It is, however, observed that the effect of ore mineralogy, which is a major contributing factor during ore and medium interaction, during separation, has not been properly taken into account, apart from the fact that ore mineralogy form a basis for HMS efficiency. The literature, however, does not cover a thorough investigation of the relationship between the recovery of diamond bearing ores and stability of Ferrosilicon grades media, as a function of physicochemical properties of ferrosilicon. Eight samples of Ferrosilicon, four milled and four atomized were used to prepare media to recover value from kimberlitic ore, alluvial ore and synthetic ore in a laboratory set-up HMS. Both Ferrosilicon and ore samples were characterized with the following techniques before use: XRD, XRF, SEM-EDAX and Screening, to investigate physico-chemical properties of ferrosilicon and ore mineralogy. The used Ferrosilicon was also characterized to investigate any v changes as Ferrosilicon medium interacted with the ores. Settling tests were performed on each Ferrosilicon grade to investigate media stability before and after recovery exercise. The stability of the media was then related to the recovery of each ore. In-circuit sample of ferrosilicon was collected from Letšeng diamonds to compare any changes with Ferrosilicon used in the laboratory, and also used to study the effects of contamination on the degradated medium. All recovery results were done in a static HMS, but in practice dense medium cyclones are widely used. The screening characterization technique revealed that there was a loss of finer particles size fraction, predominant in sieves 75 microns and 45 microns and that loss was highest with atomized grades than milled ferrosilicon grades. Minimal changes in density and chemical compositions were observed for each ferrosilicon grade. The loss of the finer fraction was found to effect changes in the settling rate of each ferrosilicon grade differently, hence changes in the stability of their media. The efficiency (Ep) of separation was found to vary with each grade of Ferrosilicon used, accompanied by a shift in cut point density indicating the influence of grade on the separation efficiency. The effects of medium stability on recovery for both ores showed that although both ores percentage recoveries differ, the trend of medium stability to recovery, with each Ferrosilicon grade, is the same. However, the recovery was found to be more dependent on the density of the medium, as the effects of loss of finer particle size fraction did not show any significant contribution to recovery, but rather on the medium loss. The mineralogy of the ores also had been observed to give a minimal or no contribution to the separation efficiency, if related to recovery. Milled Ferrosilicon is further recommended over atomized Ferrosilicon, based on cost and stability. The highest loss of atomized Ferrosilicon could escalate the operating costs and affect the stability of the medium. It should be remembered that the purchasing costs of atomized grades is higher than that of milled grades.

This is a multi-method research which consists of four studies. The first examined the influence of cultural values and ethnic identity on collective self-esteem, acculturative stress and attitudes toward seeking psychological help among 117 Saudi students living and studying in the UK, 20 of them were interviewed in the second part of the study in order to examine their acculturation strategies and their attitude toward seeking psychological help. The measures used were: Asian Values Scale (AVS), Male Arab Acculturation Scale (MAAS), Male Arabic Ethnic Identity Measure (MAEIM), Attitudes toward Seeking Professional Psychological Help-Short Form (ATSPPH-SF), and Collective Self-Esteem (CSE-R). The study sample was divided into two groups: 49 (Junior) newly arrived students and 68 (senior) students who had spent more than one year in the UK. Also, gender and marital status were considered as variables. Interviews were conducted to examine the questionnaire's findings in depth. Results supported the hypothesis that adherence to original cultural values is a positive predictor of collective self-esteem. Also it was found that there was a difference between new and senior students in the scores on the following scales: AVS, CSE, SAFE, ATSPP, and MAAS Int. Results also supported the hypothesis that ethnic identity is a positive predictor of collective self-esteem. However, no relation was observed between adherence to original cultural values and students‟ attitudes towards seeking psychological help, acculturative stress, and communication styles. Also, ethnic identity did not correlate with acculturative stress. Regarding gender and marital status, findings suggest that they are not significant predictors of the research‟s dependent variables. In the third part of the study: the researcher examined and measured the effect of providing counselling sessions for a sample of 12 Saudi students during their stay in the UK using a pre- and post- Culture Shock Questionnaire, and results were compared with a control group of 12 Saudi participants who were not engaged in the counselling sessions. Results were statistically significant for the experimental group which indicated a positive effect of providing counseling services for Saudi students. In the fourth part of the study: the researcher measured the effect of reverse culture shock on students who returned home using a modified version of the Home-comer Culture Shock Scales (HCSS) and inviting view participants to take part in un formal interview. The thesis will be concluded with an explanatory conclusion which might lead to further studies.

A fundamental challenge for liquid-liquid separation techniques such as countercurrent chromatography (CCC)and centrifugal partition chromatography (CPC), is the swift, efficient selection of the two phase solvent system containing more than two solvents, for the purification of pharmaceuticals and other molecules. A purely computational model that could predict the optimal solvent systems for separation using just molecular structure would be ideal for this task. The experimental value being predicted is the partition coefficient (Kd), which is the concentration of the compound in one phase divided by the concentration in the other. Using this approach, Quantitative Structure Activity Relationship (QSAR) models have been developed to predict the partitioning of compounds in two phase systems from the molecular structure of the compound using molecular descriptors. A Kd value in the range of 0.5 to 2 will give optimal separation. Molecular descriptors are varied, examples include logP values, hydrogen bond donor values and the number of oxygen atoms. This work describes how the QSAR models were developed and tested. A dataset of experimental logKd values for 54 compounds in six different combinations of four solvents (heptane, ethyl acetate, methanol and water) was used to train the QSAR models. A set of 196 possible molecular descriptors was generated for the 54 compounds and a partial least squares regression was used to identify which of these was significant in the relationship between logKd and molecular structure. The resulting models were used to predict the logKd values of four test compounds that had not been used to build the QSAR models. When these predictions were compared to the experimental logKd values, the root mean squared error for four of the six models was less than 0.5 and less than 0.7 for the remaining two. These models were used to successfully separate a range of structurally diverse pharmaceutical compounds by predicting the best solvent systems to carry out the separation on the CCC/CPC using nothing but their molecular structure.

Magister Scientiae - MSc / South Africa s coal and platinum mineral resources are crucial resources towards creating an alternative and environmentally sustainable energy system. The beneficiation of these natural resources can help to enhance a sustainable and effective clean energy base infrastructure and further promote their exploration and exportation for economics gains. By diversification of these resources, coal and the platinum group metals (PGMs) especially palladium market can be further harnessed in the foreseeable future hence SA energy security can be guaranteed from the technological point of view. The South Africa power industry is a critical sector, and has served as a major platform in the South African socio-economic development. This sector has also been identified as a route towards an independent energy base, with global relevance through the development of membrane technologies to effectively and economically separate and purify hydrogen from the gas mixtures released during coal gasification. The South Africa power industry is a critical sector, and has served as a major platform in the SA's socio-economic development. This sector has also been identified as a route towards an independent energy base, with global relevance through the development of membrane technologies to effectively and economically separate and purify hydrogen from the gas mixtures released during coal gasification. Coal gasification is considered as a source of hydrogen gas and the effluent gases released during this process include hydrogen sulphide, oxides of carbon and nitrogen, hydrogen and other particulates. In developing an alternative hydrogen gas separating method, composite membrane based on organic-inorganic system is being considered since the other available methods of hydrogen separation are relatively expensive. The scientific approach of this study involves the use of palladium modified polyimide composite membrane. Palladium metal serves as hydrogen sorption material, deposited on polyimide substrates (composite film) by electroless technique. Polyimide is a class of polymer with excellent physico-chemical properties such as good mechanical strength, superior thermal stability and high resistance to chemical attack. In this study, a composite polymer-palladium membrane was developed and investigated to determine the prospect of using this membrane as a cheap, accessible, reliable and efficient system to separate and purify hydrogen gas. Prior to the palladium metal plating, the challenge of metal adhesion on glassy polymer such as polyimide film was addressed by chemical etching and unirradiated and irradiated polyimide film surface using NaOH, NaOCl and a mixture of NaOH/NaOCl solutions. The time of etching was varied and the overall effect of this surface treatment was deeply investigated using Fourier transform infrared (FTIR) spectroscopy. The FTIR study focused on the structural deformation of the polyimide functional group units and the emergence of ‘active sites’ along the polyimide backbone structures that have been identified to allow the Pd metal exchange on the functionalised polyimide film. The detailed use of FTIR spectroscopic technique in this study on the etched unirradiated and irradiated polyimide film was to understand the chemical interaction between the polyimide functional group units and the chemical etchants. The surface morphology of unirradiated and irradiated polyimide samples was studied using SEM, the depth profile (penetration) of palladium particles after electroless deposition on the polyimide matrix was investigated by SEM and TEM analysis. As for the alkaline etched irradiated polyimide, pore distribution, shape and size depended on the etching time and solution. In the XRD analysis, the palladium modified unirradiated polyimide film indicated the diffraction peaks of palladium metal in the (1,1,1), (2,2,0) and (2,0,0) planes present in the polyimide surface, and the peel test showed that the strength of adhesion of palladium on unirradiated surface was low compared to the palladium modified irradiated polyimide. The NaOH solution showed the best etchant at 20 minutes for the unirradiated palladium modified polyimide. The hallmark of this study was the design, fabrication and assemblage of home-built hydrogen diffusion reactor unit used to measure rate of hydrogen diffusion property of unirradiated and irradiated polyimide films from 25 °C to 325 °C. The rate of hydrogen diffusion was observed to depend on the etching time of polyimide surface before and after the polyimide surface irradiation treatment. / South Africa

Magister Legum - LLM / The 1996 Constitution of the Republic of South Africa is the supreme law of the Republic and in enjoying this status it is prescribing the composition of the three different arms of government as well as each branch’s status within the new constitutional dispensation. Prior to this era of constitutional supremacy South Africa was subject to the principle of parliamentary sovereignty, an era where the courts could only challenge legislation on procedural grounds, but had no general power to declare legislation unconstitutional. The Constitution further provides for a separation of powers between these arms of government, and it has vested the judicial authority in the courts and conferred strong judicial review powers upon the Constitutional Court. The head of executive has recently argued that “the powers conferred on the courts cannot be regarded as superior to the powers resulting from a mandate given by the people in a popular vote”. The preceding quote is one of many statements and claims that forms part of a national debate on the nature and scope of the Constitutional Court’s powers in South Africa. The Constitutional Court has in recent years handed down judgments that were not favourable to the legislative and executive arms of the South African government. These judgments are evident in the existing and on-going tension between, the three arms of government.

Magister Scientiae (Medical Bioscience) - MSc(MBS) / Passage of spermatozoa through the female reproductive tract is essential for the regulation of fertilization, ensuring that healthy sperm reach the oocyte. Previous studies were devoted to morphological selection of sperm cells by the cervical mucus. However, research prove that the loss of integrity of the sperm plasma membrane is associated with infertile men, irrespective of their normal semen parameters. This indicates that the sperm plasma membrane plays an important role in fertilization. Further studies indicated that sperm surface proteins assist penetration through the female reproductive tract and would therefore provide useful insight in understanding other factors associated with male infertility. The aim of this project was to determine if there are any differences between sperm surface proteins of fertile donor samples in relation to infertile patient samples using different separation techniques and different detergents. Three different sperm separation techniques were employed, including wash, swim-up (SU) and Percoll density gradient centrifugation (DGC).Parallel to this, the deoxy-ribose nucleic acid (DNA) fragmentation of these cells were analysed for comparison of the extent of DNA damage induced due to different separation techniques used. This provided evidence that the best separation technique is the DGC as it minimises the amount of DNA fragmentation caused. Four different detergents were used in the process of extracting the membrane proteins from spermatozoa, namely sodium dodecyl sulphate (SDS), saponin,cetyl-trimethyl-ammonium bromide (CTAB), and TWEEN-20. The membrane proteins were then separated on a12% SDS poly-acrylamide gel electrophoresis (PAGE), and analysed by Coomassie blue and silver staining techniques as well as densitometry. Due to the different chemical nature of the detergents that extracted different surface proteins, CTAB (cationic) and SDS (anionic) extracted the most because of its strong solubilising abilities as non-ionic detergents. Common proteins that were extracted in donor samples included; 115, 92.5, 89, 61, 55.5, 51.5, 47, 44.5, 43, 38.5, 34 and 28 kDa proteins. In patients, commonly occurring proteins included; 92.5, 74.5, 70, 60.5, 51.5, 50, 44.5, 43, 36, 29.5, and 25.5 kDa proteins. Marked differences were found between membrane proteins extracted from donor samples in comparison to patient samples. Identification of these proteins was done using the SwissProt database and a literature search. Mostly non-genomic progesterone receptors were identified; others included oestrogen receptor, a phosphotyrosyl protein, P34H, equatorial segment protein, mannose lectin receptor, human guanylylcyclase receptor, epididymal protease inhibitor receptor, PH30 and estradiol binding protein. The function of the membrane surface proteins identified in this study plays a vital role in fertilization. A few of these functions include sperm attachment and binding to the oocyte as well as penetration thereof. Others play a role in signalling events such as capacitation, hyperactivation and acrosome reaction. The absence of these proteins in patient sperm possibly accounts for the functional inability to successfully achieve fertilization suggesting that this provides molecular insight to reasons for infertility amongst men. In addition to this, proteins presented by patient samples that were absent in healthy donors may too account for their infertility status. Estradiol binding protein and PH30 are two proteins presented only in patient samples. Their function plays a role in the inhibition of the acrosome reaction and sperm-egg fusion, respectively. In conclusion, these differences in protein expression between fertile donors and patients may form the molecular basis of infertility amongst men and indicates possibilities for novel proteonomic approaches to improve andrological diagnosis in future.

‘The non-dialectical mean between which extremes are suspended constitutes something like an interface, which is the condition of the possibility and impossibility of seemingly seamless systems and structures. When radically conceived, this interface extends beyond every margin of difference to ‘contaminate’ opposites that once seemed fixed.’ (Taylor 1997: 269) The site is positioned at the juxtaposition of: poor opposite rich, inviting opposite closed, dense urban fabric opposite sprawling suburban, exclusive opposite inclusive. Therefore the question arise: when dealing with an island placed amidst these contradictions, how do you include and acknowledge all? By providing for the one inevitably leads to the exclusion of the other, yet again reinforcing the legacy apartheid left South African urban environments. Therefore, the search for the INbetween informs the merging of these realms by means of a public park and recreational youth facility at the juxtaposition of these contrasting realms. The merge creates a dynamic tension between public / private, rich / poor, active / contemplative, movement / rest and inside / outside which informs the design philosophy. The architecture investigates the fading of boundaries. The design problem is a youth facility with recreational, educational and counselling functions, for youth living within the inner city area of Hillbrow, Houghton, Berea and Parktown. It is part of the City of Johannesburg’s Child Friendly City Initiative (CFCI) and will be managed by Non Governmental Organisations (NGO) operating in the area. Therefore, the centre will be a facility of which youth can take ownership of. A platform for ‘accidental’ interaction between the people from these different communities. The centre needs to provide opportunities and facilities that would entice, intrigue and motivate in order to resist the attraction of street life and drugs, through the provision of recreational activities, entertainment, educational facilities in the form of skills and entrepreneurial training, counseling and medical assistance. / Dissertation (MArch(Prof))--University of Pretoria, 2007. / Architecture / unrestricted