This laboratory column (125 cm high, 15 cm diameter) research investigated solids and P removal from liquid swine manure amended with calcium carbonate, magnesium sulphate, alum and polyacrylamide (PAM). Results showed that PAM was the most effective amendment for enhancing solids removal from manure containing 1% initial total solids (TS). The effectiveness of PAM was lower at 5% and 8% than at 1% due to resuspension of solids occurring at settling times beyond 4 h. After 24 h of settling, P removal from non-amended manure was comparable to that in amended manure and decreased with TS concentration for all amendments except alum, which was equally effective at all TS concentrations. These results indicate that, for manure containing 1% TS, P can be adequately removed by gravity separation without addition of chemical amendments while alum is a more effective amendment for removing P from manure containing higher (5% and 8%) TS.

Pure fluorocarbon gases can be sold for up to 30 USD/kg, if they were manufactured locally. Due to the absence of local demand, South Africa at present has less than 0.3 % of the fluorochemical market and most fluoro–products used in the South African industry are currently imported. The depolymerisation of waste polytetrafluoroethylene (PTFE or Teflon) filters in a nitrogen plasma reactor results in the mixture of gases which includes N2, CF4 and C3F6. An existing challenge entails the separation of these gases, which is currently attained by an energy intensive cryogenic distillation process. Both the small energy requirements as well as the small process streams required, make a membrane separation an ideal alternative to the current distillation process. Based on our research groups existing expertise in the field of zeolite membranes, it was decided to investigate the separation capability of zeolite (MFI, NaA, NaY, and hydroxysodalite) coated tubular ceramic membranes for the separation of the above mentioned gases. The separation study was subdivided into adsorption studies as well as single and binary component studies. CxFy gas adsorption on MFI zeolites. Tetrafluoromethane (CF4) and hexafluoropropylene (C3F6) were adsorbed on zeolite ZSM–5 and silicalite–1 to help explain permeation results through zeolite membranes. According to the obtained data, the separation of CF4 and C3F6 would be possible using adsorption differences. The highest ideal selectivities (~ 15) were observed at higher temperatures (373 K). While the CF4 adsorption data did not fit any isotherm, the heat of adsorption for C3F6 adsorbed on ZSM–5 and silicalite–1 was calculated as –17 and –33 kJ/mol respectively. Single gas permeation. A composite ceramic membrane consisting of a ceramic support structure, a MFI intermediate zeolite layer and a Teflon AF 2400 top layer was developed for the separation of N2, CF4 and C3F6. The adsorption properties of the Teflon AF 2400 sealing layer was investigated. A theoretical selectivity, in terms of the molar amount of gas adsorbed, of 26 in favour of the C3F6 vs CF4 was calculated, while the N2 adsorption remained below the detection limit of the instrument. While the ideal N2/CF4 and N2/C3F6 selectivities for the MFI coated support were either near or below Knudsen, it was 5 and 8 respectively for the Teflon coated support. Ideal selectivities improved to 86 and 71 for N2/CF4 and N2/C3F6 when using the composite ceramic membrane, while CF4/C3F6 ideal selectivities ranged from 0.9 to 2, with C3F6 permeating faster though the composite ceramic membrane. Zeolite based membrane separation. Inorganic membranes (?–alumina support, NaA, NaY, hydroxysodalite, MFI) and composite membranes (Teflon layered ceramic and composite ceramic membrane) were synthesized and characterized using the non–condensable gases N2, CF4 and C3F6. For the inorganic membranes either near or below Knudsen selectivities were obtained during single gas studies, while higher selectivities were obtained for the composite membranes. Subsequently, the MFI, hydroxysodalite and both composite membranes were chosen for binary mixture separation studies. The membranes exhibited binary mixture permeances in the order Teflon layered ceramic > hydroxysodalite > MFI > composite ceramic, which was comparable to the single gas permeation results. The highest separation for N2/CF4 (4) and N2/C3F6 (2.4) was obtained with the composite ceramic membrane indicating that the Teflon layer was effective in sealing non–zeolitic pore in the intermediate zeolite layer. The aim of this project was met successfully by investigating a method of fluorocarbon gas separation by zeolite based membranes using various inorganic and composite membranes with single and binary mixtures. / Thesis (Ph.D. (Chemistry))--North-West University, Potchefstroom Campus, 2012.

South Africa is a land blessed with an abundance of mineral deposits. Yet, despite this, very little value adding of minerals exists. Most of the mined minerals are exported, where it is reworked into valued items. The country subsequently imports the valuable items at a much higher cost. In the 2006/7 financial year, the government made the decision to support several projects aimed at adding value to the mined minerals and by so doing, creating job opportunities. One such project was identified for the mineral Fluorite (CaF2). Fluorite is exposed to a controlled burn in a plasma reactor, producing an array of different fluorocarbon gases used in the electronics industry and for commercial polymers like Teflon®. Currently, fluorocarbon gases are separated using a series of cryogenic distillation columns. Although this technique has proven to be successful, it has several negative aspects such as the high cost involved when operating at cryogenic conditions as well as difficulty handling the gases at these sub–zero temperatures. It was proposed to study the possibility of using membranes to separate fluorocarbon gases at ambient conditions. Several membranes were screened to determine which one is best suited for this application. Two Teflon® based membranes were selected from this data. One of the membranes had a PAN support, while the other had a PEI support. Pure gas data for both membranes showed promising results. It yielded the highest flux for C3F6, followed by N2 and CF4. c–C4F8 was not used because it was demonstrated that the gas tends to condensate at low pressures. It is recommended to rather use pressure swing condensation to remove this gas from the mixture before the remainder is purified using membranes. Both membranes behaved similarly, with selectivity between C3F6 and CF4, and N2 and CF4; all above 10. By including the permeate pressure in the Solution–diffusion model, it was possible to model the pure gas data Binary feed gas mixture experiments showed a large amount of coupling existing between the feed gas mixtures. The result is a decrease in the selectivity as well as the total flux of the gas mixture. Partial fluxes were modelled by introducing a thermodynamic factor that was shown to follow a power law equation. The PAN–supported membrane outperformed the PEI–supported one; it was decided to use this membrane from this point onwards. Analysis of the ternary feed mixtures showed a strong selectivity towards the gas abundant in the feed blend. The existence of convective diffusion was proven, and included in the modelling, as well as a breakthrough pressure constant. This is indicative of strong interaction between the different gases and the membrane. Throughout the study it became clear that the difference in surface charge between the gases and the membrane were decisive. Opposite charges between a gas (C3F6) and the membrane aided in gas permeation. Membrane separation of fluorocarbon gases at ambient conditions is possible. Teflon® based membranes are recommended. It will be advantageous to study the effect of elevated temperatures on the separation efficiency of such a system. / Thesis (M.Ing. (Chemical Engineering))--North-West University, Potchefstroom Campus, 2012.

This thesis is concerned with the use of kinetic resolution strategies for the preparation of enantiomerically pure materials. Chapter 1 introduces kinetic resolution. The limitations of conventional kinetic resolutions are described and the methods used to overcome these limitations are discussed. Chapter 2 presents a double kinetic resolution strategy where the recovered reactant from the first kinetic resolution is used as starting material in a second kinetic resolution. In the second kinetic resolution the major enantiomer present in the starting material is the faster reacting enantiomer. Application of this double kinetic resolution strategy to the Sharpless epoxidation is shown to enable enhanced product enantiomeric excesses to be obtained. Chapter 3 presents an alternative double kinetic resolution strategy where the product from the first kinetic resolution is used as starting material in a second kinetic resolution. In the second kinetic resolution the major enantiomer present in the starting material is the faster reacting enantiomer. Application of this double kinetic resolution strategy using lipase mediated esterification and hydrolysis reactions is shown to enable enhanced product yields to be obtained. Chapter 4 describes the preparation of an enantiomerically pure 2-substituted monoprotected propan-1,3-diol derivative via combination of an asymmetric synthesis and a kinetic resolution. Chapter 5 describes the preparation of the pheromone sulcatol in enantiomerically pure form via combination of an asymmetric synthesis and a kinetic resolution. Chapter 6 presents an investigation into the structure of lithium(α-methylbenzyl)- benzyl amide. Chapter 7 describes an attempted dynamic kinetic resolution of 2-substituted monoprotected propan-1,3-diol derivatives. Chapter 8 describes an attempted preparation of the iron crotonyl complex E-[(η⁵-C₅H₅)Fe(CO)(PPh₃)(COCH=CHCH₃)] in enantiomerically pure form via enzymic kinetic resolution.

Master Paper consist of an introduction, three supplementing each other parts, which first part determined position of prosecutor among system of state powers separation more in theoretic aspect, second part – in process aspect, third part gave some specific features of prosecutor powers, those analysis conclusion is given. At the end of the work the list of used literature, and a summary in Lithuanian and English languages is presented. Meaning to discover in which aspect and volume of work the status or prosecutor will be investigating, a conception of principle of state powers separation and the main features of powers at first in work was discussed. An analysis of prosecutor status among system of state powers separation makes the main part of work. At first analyzed position of prosecutor among system of state powers separation in theoretic aspect, development of status of prosecuting magistracy and relation between prosecuting magistracy and other powers in Lithuania position, examples of status of prosecutor among system of state powers separation in other countries, experience determining this relation, - that taking into account that it could be possible more comprehensively disclosed status of prosecutor and position at first among system of government powers separation and among system of other justice institutions. Two research social test of subjects of Master Paper made easer this work. At the second part of work analyzed powers of prosecutors in... [to full text]

The preparation and characterisation of chelating sorbents suitable for the high efficiency separation of trace metals in complex samples, using a single column and isocratic elution, is described. Hydrophobic, neutral polystyrene divinylbenzene resins were either impregnated with chelating dyes or dynamically modified with heterocyclic organic acids, using physical adsorption and chemisorption processes respectively. A hydrophilic silica substrate was covalently bonded with a chelating aminomethylphosphonic acid group, to assess the chelating potential of this molecule. These substrates were characterised in terms of metal retention capability (selectivity coefficients and capacity factors), separation performance, column efficiency and suitability for analytical applications. Chelating molecules with different ligand groups were found to have unique selectivity patterns dependant upon the conditional stability constants of the chelate. Other factors, including mobile phase constituents - complexing agents, ionic strength and pH, column length and column capacity were additionally investigated to examine their effect upon the separation profiles achieved. The promising metal separation abilities illustrated by a number of these chelating columns were exploited for the determination of trace toxic metals in complex sample matrices using High Performance Chelation Ion Chromatography (HPCIC). This included the determination of beryllium in a certified stream sediment, uranium in seawater and a certified stream sediment, and cadmium, lead and copper in a certified rice flour. The results for each analysis fell within the certified limits, and reproducibility was good. The optimisation of post column detection systems using chromogenic ligands additionally gave good detection limits for the metals in each separation system.

This study aims at providing a new technique for the isolation and culture of goldfish microglial cells. So far no protocol has been designed for the growth of these cells in vitro, despite the growing interest in the remarkable capacity of goldfish central nervous system (CNS) for regenerating severed axons. This newly developed technique has little or no similarity to those used in the isolation of mammalian microglia, and is distinguished by its simple setup and its fast yield for microglial cells. In addition, a virtually pure population of microglia was generated when plated on untreated plastic dishes, eliminating further need for purification. This technique may thus provide a starting point for future characterization of the microglial cells in vitro, which may eventually help toward building a better understanding of the function and biology of these cells. A preliminary morphological characterization of the cells has also been conducted, in addition to groundwork experiments on the phagocytic activity of these cells in vitro, using myelin to stimulate phagocytosis. These assays were oriented toward providing a comparison to the mammalian cultures of microglia, and so far, displayed several similarities in morphologies and phagocytosis.

Thermodiffusion is one of the mechanisms in transport phenomena in which molecules are transported in a multicomponent mixture driven by temperature gradients. Thermodiffusion in associating mixtures presents a larger degree of complexity than non-associating mixtures, since the direction of flow in associating mixtures may change with variations in composition and temperature. In this study a new activation energy model is proposed for predicting the ratio of evaporation energy to activation energy. The new model has been implemented for prediction of thermodiffusion for acetone-water, ethanol-water and isopropanol-water mixtures. In particular, a sign change in the thermodiffusion factor for associating mixtures has been predicted, which is a major step forward in modeling of thermodiffusion for associating mixtures. In addition, a new model for the prediction of thermodiffusion coefficients for linear chain hydrocarbon binary mixtures is proposed using the theory of irreversible thermodynamics and a kinetics approach. The model predicts the net amount of heat transported based on an available volume for each molecule. This model has been found to be the most reliable and represents a significant improvement over the earlier models. Also a new approach to predicting the Soret coefficient in binary mixtures of linear chain and aromatic hydrocarbons using the thermodynamics of irreversible processes is presented. This approach is based on a free volume theory which explains the diffusivity in diffusion-limited systems. The proposed model combined with the Shukla and Firoozabadi model has been applied to predict the Soret coefficient for binary mixtures of toluene and n-hexane, and benzene and n-heptane. Comparisons of theoretical results with experimental data show a good agreement. The proposed model has also been applied to estimate thermodiffusion coefficients of binary mixtures of n-butane & carbon dioxide and n-dodecane & carbon dioxide at different temperature. The results have also been incorporated into CFD software FLUENT for 3-dimensional simulations of thermodiffusion and convection in porous media. The predictions show the thermodiffuison phenomenon is dominant at low permeabilities (0.0001 to 0.01), but as the permeability increases convection plays an important role in establishing a concentration distribution. Finally, the activation energy in Eyring’s viscosity theory is examined for associating mixtures. Several methods are used to estimate the activation energy of pure components and then extended to mixtures of linear hydrocarbon chains. The activation energy model based on alternative forms of Eyring’s viscosity theory is implemented to estimate the thermodiffusion coefficient for hydrocarbon binary mixtures. Comparisons of theoretical results with the available thermodiffusion coefficient data have shown a good performance of the activation energy model.

The recovery of organometallic catalysts from polymer matrices is of great importance in promoting the application of homogeneous catalysts in industry. Such a green recovery technique will not only popularize the techniques of green catalytic hydrogenation of polymers by Rempel’s group, but also consummates the technique of heterogenization of organometallic catalysts. The high value product of hydrogenated nitrile butadiene rubber (HNBR) with dissolution of Wilkinson’s catalyst [RhCl(TPP)3] was selected as the model polymer matrix for developing a green separation technique. The supercritical carbon dioxide (scCO2) soluble fluorous Wilkinson’s catalyst [RhCl(P(p-CF3C6H4)3)3] was synthesized and shown exhibit a very limited activity in the catalytic hydrogenation of bulk HNBR. Its recovery from a HNBR matrix using scCO2 however failed. In spite of the assistance of the scCO2 dissolvable chelating ligand thenoyltrifluoroacetone (TTA), the weak compatibility of scCO2 with rhodium complexes failed again as an extraction solvent for the HNBR matrix. Inspired by the merits of CO2-expanded liquids (CXLs) and the versatility of CO2 in changing the physical properties of polymer melts, CXLs were tested as extracting solvents for separation of Wilkinson’s catalyst from bulk HNBR. CO2-expanded water (CXW) and CO2-expanded alcohols including methanol and ethanol (CXM and CXE) were examined with the assistance of a variety of chelating agents. The investigated chelating agents include ethylenediaminetetraacetic acid (EDTA), ethylenediaminetetraacetic acid disodium salt (EDTA-Na2), diethylenetriamine (DETA), N,N,N',N',N"-pentamethyldiethylenetriamine (PMDETA), and N,N,N’,N’-tetramethylethylenediamine (TMEDA). CXM and PMDETA were recognized as the optimal combination of extracting solvent and chelating agent for recovery of Wilkinson’s catalyst from HNBR. An extraction system consisting of CXM and PMDETA was carefully investigated with respect to the effects of temperature and pressure on the extraction performance over the temperature range of 40 to 100 °C and the pressure range of 20 to 200 bar. Increasing temperature effectively increased the extraction rate and became less influential when the temperature was above 80 °C. Increasing pressure at a fixed temperature was found to improve the extraction rate followed by suppressing it. Nevertheless, further increasing the pressure to an extreme high value above the respective critical point was able to promote the extraction rate again. The complex effects of pressure were thoroughly investigated by the means of analyzing the dissolution behavior of CO2 in HNBR and the variation of the extraction phase composition at different operational conditions. 0.14 g/mL was determined as the CO2 density by which the optimal pressure at a fixed temperature can be estimated. Based on a careful interpretation of the experimental results, an extraction mechanism was illustrated for interpreting the present extraction system. Additionally, the reactions involved in the extraction process were illustrated to reveal the principal challenges present in the extraction process and pointed out the potential solution for eliminating the obstacles. Two special operations-sequential operation and pressure varying procedure were tested for their effectiveness in enhancing the extraction ratio. A pressure varying procedure was found to be beneficial in further improving the extraction ratio, while sequential operation did not show any promise in enhancing the recovery. At last, the developed technique was shown to be highly efficient in applying it to HNBR particles coagulated from the HNBR latex. A residue of 59 ppm rhodium was obtained after 9 hours of operation. This study establishes a technology platform for separating the expensive catalyst from the polymer matrix, using “green” CO2-expanded liquids.

The worlds largest exodus of children is considered the transfer of circa 70,000 children from Finland to Sweden from 1939 to 1945. The experience of the Finnish war children contains a distinctive wealth of knowledge which should not be lost. It is important from a social and cultural-anthropological point of view to pass on this collection of experiences without misrepresentation and to interpret the material to the best of my ability. Childhood experiences have a great psychological importance on how an adult his/her life. When a person's social world changes, their psychological world is also threatened. This is what happened to the Finnish war children. To be a foster child, to be a war child, to be a Finnish war foster child entails something very distinctive. Such a child has experienced separation and break-up from the biological family, confrontation with the foster family or orphanage, sometimes difficult experiences from the war itself and a change of language and culture, all of which can be very traumatic. The Finnish war children were "child refugees" and their experiences must be understood on this basis. Finnish war children represent a unique event in our chaotic world. Therefore, one can say that my interpretation has a limited scope. I cannot refer to the broader "immigrant debate." My research is of a special character and my material is unique! In our world there are countless child refugees, children who live in extremely exposed conditions and who have lost their parents. About the Finnish war children's experience it has been said that "it may not happen again". This is a very careless statement - what do we know of the world's future? No, this may not happen again. But it can happen again. The Finnish war children remember experiences which are frightening and fascinating, but which are also important for us to understand and learn from in order to be able to deal with children who are in that most exposed of situations - refugees from war and persecution, but without the protection of a parent. / digitalisering@umu