The thesis describes some aspects of the aqueous solution chemistry of chlororuthenate(III) and chlorocarbonylruthenate(III or II) complexes including their reactivity toward carbon monoxide. This led to the synthesis and characterisation of a polymeric complex [HRu(CO)₃][sub n], which is formally a Ru(I) derivative. The use of these ruthenium complexes for activating CO catalytically was studied, especially for the carbonylation of amines. The [HRu(CO)₃][sub n] polymer was characterised by microanalysis, infra-red and high-field ¹H n.m.r. , and its chemistry In donor solvents in which it was soluble. The polymer may be formed by reductive carbonylation of chloro complexes of Ru[sup II], Ru[sup III](CO), Ru[sup II] (CO), Ru[sup II] (C0)₂ and Ru[sup II]CO)₃, and stoichiometric evidence suggests processes such as: [chemical reactions 1 to 4]. Increasing acidity and chloride concentration inhibit the reductive carbonylation process, which likely requires simultaneous coordination of cis CO and OH ligands. Reactions (1) - (4) are accompanied by formation of smaller amounts of low valent ruthenium complexes including Ru₃(CO)₁₂, which could result from a reductive carbonylation process such as [chemical reaction 5] or via 'combination' of Ru[sup I] and Ru[sup -I] species. Evidence is presented for reaction (5) starting with CsRu(CO)₃Cl₃. Reductive carbonylation 2- of Ru(CO)₂Cl₄⁻² (reaction (4)) shows autocatalytic gas uptake plots, indicating catalysis of the reaction via a Ru(0) or Ru(I) intermediate. The kinetics for the carbonylation of piperidine to N-formyl piperidine catalysed by each of the complexes [HRu(CO)₃][sub n], [Ru(CO)₂(OAc)(pip)]₂, and CsRu(CO)₃Cl₃, have been studied under mild conditions. Mechanisms are proposed to explain the observed kinetics and in each case a tricarbonyl monomeric species appears to be the active catalyst. A CO insertion reaction in a Ru(CO)₃ (pip)[sub x] intermediate must be involved. A scheme such as (6) e.g. [chemical reaction 6] requires a hydride shift, likely metal activated. Alternatively, piperidine could behave as a proton acceptor with the reaction proceeding via a carbamoyl intermediate (reaction (7)). [chemical reaction 7] Both [HRu(CO)₃][sub n] and CsRu(C0)₃Cl₃ carbonylate piperidine in a stoichiometric reaction in the absence of CO, and in the case of the cesium salt evidence suggests the following reactions: [chemical reactions 8-9] Only secondary amines were carbonylated effectively. Attempts to isolate and characterise ruthenium complexes via the reactions [HRu(CO)₃][sub n] or CsRu(C0)₃Cl₃with piperidine proved frustrating, although one complex isolated from the polymer reaction is thought to be H₂Ru₂(CO)₄(pip)₃, and an oxygenated solution of [HRu(CO)₃][sub n] in piperidine yielded a complex which analysed well for [HRu(CO)₂(pip)]₂•0₂. / Science, Faculty of / Chemistry, Department of / Graduate

The aim of the thesis is to fabricate Schottky contact carbon nanotube field effect transistor (CNFET) using the dielectrophoresis (DEP) to resolve the alignment issue and show its transistor behaviour. The work presented is a combination of fabrication and simulation of CNFET. Fabrication of the device electrode had been done using the electron beam lithography to achieve a channel length of 150nm and analysis was done on an optical microscope, SEM, AFM and Raman spectroscopy. Second half of the thesis provides a solution to “bottleneck communication” between microprocessor and memory to increase the computation for applications like AI, IoT etc and 3D monolithic memories. As a solution, we propose a novel CNFET based processing in-memory architecture using a novel CNFET dual port single-ended SRAM bit cell. The combination of the CNFET and processing in-memory can be a new phase for memory and computation.

The subject matter of the research conducted in this mini dissertation is carbon tax within South Africa. It investigates the Carbon Tax Act 15 of 2019 to determine whether it is suitable for the South African economy. The tax was implemented in South Africa to send a strong signal to producers and consumers to change their polluting behaviour, reduce their carbon emissions and initiate the transition to a low-carbon economy. Pigouvian taxes such as carbon tax have the potential to correct market failures and negative externalities by reflecting the true costs of carbon intensive activities in the price of carbon products. The ‘double dividend hypothesis’ is a foundational principle of carbon tax, it assumes that the carbon tax is capable of achieving double and perhaps in special cases, triple benefits for the economy and society at large. Placing a price on carbon emissions increases the price of carbon-intensive goods, consequently polluters are required to pay for their emissions. Decision-making is heavily influenced by price; therefore, the carbon tax corrects the defective behaviour by incentivising the public to consider the cost of carbon emissions going forward. An improvement in environmental outcomes as behavioural patterns change and shift to renewable and greener energy alternatives, and an improvement in economic and social welfare funded by revenue generated from the tax gives rise to the double benefit. The triple benefit comes in where the carbon tax also reduces poverty.The increase in revenue from carbon tax could improve economic efficiency and reduce the overall burden on the tax system. The tax will have widespread effects, many of which cannot accurately be predicted before some time has been allowed for it to be operational. This study considers the framework of carbon tax within South Africa and critically evaluates whether it is capable of achieving the double dividend. / Mini Dissertation (LLM (Tax Law))--University of Pretoria, 2021. / National Research Foundation/ NRF / Mercantile Law / LLM (Tax Law) / Unrestricted

Forests are sites for mercury deposition, where accumulation in aquatic environments can occur. Soil total mercury (THg), C and N to 15 cm were studied in ten seasonal pond basins in a northern hardwood forest (Minnesota, USA). Pools and concentrations of THg were lower in uplands than in ponds, indicating downslope transport or differential deposition. In uplands, THg concentrations were the same in 0-2 and 2-5 cm depths and then decreased, whereas density peaked in 2-5 cm, highlighting the importance of bulk density on mass. Carbon and N trends were similar to THg. Apart from pond centers, strong positive relationships between THg and C were observed. Upland slope length, graminoid cover, basin area and tree height accounted for over half of THg variance at pond edge. Understanding the distribution, trends and contributing factors of soil THg can further efforts toward immobilization and sequestration, thus minimizing the potential for bioaccumulation. / United States Forest Service / North Dakota State University

Calorimetric heats of mixing per mole, ΔH_x^M, and a solid-liquid phase diagram were obtained for the system water--p-dioxane at 25°C over the entire range of composition. From these data are derived values for the partial molar heat contents, activities and free energies and entropies of mixing. The excess free energy-composition curve, which is roughly parabolic in shape, gives little indication of the extent of interaction in this system. The ΔH_x^M values, however, range from 115 cal./mole endothermic to 142 cal./mole exothermic. A sharp exothermic dip occurs at a mole fraction of 0.143, which corresponds to a ratio of 6.00 water molecules to each dioxane molecule. Minimum values for the freezing points and entropies of mixing also occur at approximately this same composition. Possible short range structures that could contribute to the properties of this system are discussed. ΔH_x^M data were determined calorimetrically for the ternary and the three binary systems that can be formed from carbon tetrachloride (1), cyclohexane (2), and benzene (3). The following analytical equations, in which x_i is the mole fraction of component i, summarize these data: ΔH_12^M = x_1x_2 [ 160.8 / 18.9 (x_1 - x_2) - 20.2(x_1 - x_2)^2 ] 15,25,and 35°c ΔH_13^M = x_1x_3 [ 103.2 / 11.0 (x_1 - x_3) - 13.3(x_1 - x_3)^2 ] 25°C ΔH_13^M = x_1x_3 [ 96 / 4.17 (x_1 - x_3) - 13.19 (x_1 - x_3)^2 ] 10°C ΔH_23^M = x_2x_3 [ 3105 - 7.980 T - (1303-4.370 T) (x_2 - x_3) / (1738 - 5.486 T) (x_2 - x_3)^2 ] 15,25,and 35°C ΔH_123^M = x_1x_2 [ 160.8 / 18.9 (x_1 - x_2) - 20.2 (x_1 - x_2)^2 ] / x_1x_3 [ 103.2 / 11.0 (x_1 - x_3) - 13.3 (x_1 - x_3)^2 ] / x_2x_3 [ 726.0 / 102.4 (x_2 - x_3)^2 ] 25°C Solid-liquid phase equilibria data were also obtained for these systems. This information for the system cyclohexane-benzene, together with the thermal data, made possible the calculation of the partial molar heat contents, L_i, and the excess free energies, ΔF_x^E, and entropies, ΔS_x^E, of mixing per mole as functions of composition. These data are summarized by the following expressions: L_2 = x_3^2 [ (6146 - 17.836T) - (19116-61.368T) x_2 / (20856-65.832T) x_2^2 ] L_3 = x_2^2 [ (3540-9,096T) - (8692-26.408T) x_3 / (20856-65.832T) x_3^2 ] ΔF_x^E = x_2x_3 [ 310.6 / 2.33 (x_2 - x_3) / 40.0 (x_2 - x_3)^2 / 130.8 (x_2 - x_3)^3 ] 25°C TΔS_x^E = x_2x_3 [ 415.4 - 2.33 (x_2 - x_3) / 62.4 (x_2 - x_3)^2 - 130.8 (x_2 - x_3)^3 ] 25°C The system carbon tetrachloride-benzene proved to be especially interesting in that the phase diagram of this "near-to-ideal" system reveals a complex of approximately one benzene molecule to one carbon tetrachloride molecule composition. It is suggested that TT bonding between the electron cloud of the aromatic ring and the empty 3-d shell of chlorine may be responsible for the formation of the compound. Replacing benzene with p-xylene to increase the electron density of the ring enhanced the formation of the complex. On the other hand, either decreasing the electron density of the ring by using nitrobenzene, or decreasing the electronegativity of the chlorine atoms by substituting CHCl_3 for CCl_4 prevented complex formation. The results of this study of carbon tetrachloride-cyclohexane-benzene mixtures seem to indicate that the system carbon tetrachloride-cyclohexane is very nearly ideal, the system carbon tetrachloride-benzene is much more complex than was previously considered, and the high entropy in the system cyolohexane-benzene is probably due partially to volume change on mixing and partially to lack of randomness in the pure benzene.

The angle, distance and vibration dependence of the Ar-CO intermolecular potential is calculated using the electron gas model to obtain the short range interaction which is smoothly joined onto the long range van der Waals tail which is obtained from accurate C_6, C_7, and C_8 coefficients. Our calculated second interaction virial coefficients are compared with experiment and with a simple adjustment of the Ar-CO potential an excellent agreement is obtained. Our spherically averaged potential is also in excellent agreement with a spherical potential inferred from high energy scattering data. Simplified expressions for the scattering amplitude and differential cross section are obtained in the infinite order sudden approximation. Then, treating the rotations and vibrations in the infinite order sudden and close coupling approximations respectively, vibrational transition probabilities and relaxation rates are calculated using the Ar-CO intermolecular potential. Our calculated vibrational relaxation rates are much smaller than the experimental values.

A Thesis submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, in fulfilment of the requirements for the degree of Doctor of Philosophy in the School of Chemical and Metallurgical Engineering, University of the Witwatersrand, Johannesburg, 2019 / Due to the energy- and carbon-intensive economic structure of South Africa (SA), the country has become one of the biggest contributors to greenhouse gas emissions, emitting more CO2 than any other African country. The ratio of greenhouse gas emissions compared to per capita economic benefit, the so called carbon intensity of the economy, is amongst the highest in the world. Carbon capture and storage (CCS) seems to be the most immediate form of action that can be implemented with the possibility of instantaneous reduction of CO2. The injection of CO2 into deep-unmineable coal seams, although not commercially viable for coal production, is a possible mitigation option under CCS for permanent underground storage of CO2. As a spin-off, useful coal-bed CH4, referred to as enhanced coal bed CH4 (ECBM), could be extracted from the coal seam following CO2 injection. In SA it has been estimated that approximately 1.2 Gt of CO2 could be stored in the coalfields. Although not currently the preferred option for geological storage, coalfields provide the largest onshore CO2 storage possibility. The current research project aimed to study the fundamental differences in CO2 adsorption in a variety of SA coal samples in order to access the CO2 sorption capacities and secondly to evaluate the potential CH4 characteristics of SA coals. The investigation aimed to identify the fundamental differences around the effects of increased pressure under simulated in-seam conditions including super-critical pressures up to ~90 bar for gaseous and supercritical CO2 injection. The effects on CO2 adsorption with regard to the difference in coal moisture contents, simulated in the range from ~0.5 – 4.4% and the influence of increased temperatures in the range of 35 to 55 ˚C were carried out on ten (10) SA coals taking into consideration differences in coal properties, samples with varying rank, ash and maceral compositions were sourced for this research. Then secondly, to evaluate the desorption potential of CH4 for seven (7) selected SA coals. A High Pressure Volumetric adsorption system (HPVAS) was successfully designed and constructed in order to conduct experimental tests to generate the adsorption isotherms for the various parameters tested. Results presented show comparable results with published literature in terms of the degree of variance in coal properties (with respect to rank, maceral and mineral content, ash contents and the effects of moisture, and temperature variance) and the uptake of CO2. Higher rank coals have a greater CO2 absorption propensity, whereas lower rank bituminous coals tend to exhibit lesser CO2 uptake, however, this is dependent on the coals’ petrographic composition. It was clear that samples in the range greater than a vitrinite reflectance of 0.7% (RoVmr) exhibited increased CO2 uptake due to larger macro, increasing meso porosity and micro-pore volumes. Findings related to coal properties; revealed that coals with a higher ash content exhibited a negating effect with regard to enhanced CO2 adsorption. On average, for a 1% increase in ash content in HRC and MRC coals, a decrease of CO2 adsorption capacity of 1.1 mmol/g and 0.018 mmol/g is observed respectively. While for maceral composition these findings suggest that a specific or ideal ratio between only the maceral components, in similar rank coals, is the controlling factor for best CO2 adsorption required. In terms of addressing the adsorption parameters, such as super-critical pressure, temperature and moisture variations inherent in natural coal seams, etc., it was determined that with increased pressure, more adsorption takes place for most coal types. A very positive correlation was found to exist between adsorption of CO2 and desorption of CH4, with increased pressure injections, ranging from sub-critical to super critical pressures, exhibiting increased sorption results, irrespective of coal moisture or temperature effects. From these findings for simulated conditions regarding the effects of coal seam moisture and temperature variations, it has been concluded that results displayed an obvious decrease in CO2 sorption ranging from sub-critical to supercritical pressures overall. The decrease in CO2 sorption was as much as 77% from dry (0%) to the maximum moisture simulated value of ~4.4%. Sorption decreased almost linearly for every 1% of coal moisture increase, until the maximum coal saturation was approached at around 4%. Sorption results relating to increased temperature also displayed an inverse relationship, and hence lower overall CO2 sorption capacities were calculated. The heats of adsorption for these coals were found to be between 21.9 and 39.9 kJ/mol confirming the nature of adsorption to be physical. Results confirm that the calculated heat of adsorption (KJ/mol) and the adsorption capacity (mmol/g) are positively correlative. For investigations pertaining to CH4 desorption for CH4 saturated simulated coals (CH4 added to and then removed from coal samples due to the unavailability of freshly cored coal samples), it was observed that CO2 uptake by pressurized injection for low - high pressures certainly enhances CH4 desorption rate. Results revealed that incremental CO2 injection pressures yielded higher CH4 desorption rates, for both the HRC and MRC coals. Generally there was an observed increase in the rate of CH4 desorbed for all coals tested at 55 oC as compared to 35 oC. This can as well be attributed to the fact that the increase in temperature causes the adsorbed CH4 molecules to vibrate more due to the increased kinetic energy of the molecules. This consequently leads to ease of desorption when CO2 is pumped under pressure into the coal structure, which clearly favours ECBM potentials. Some very good findings have been highlighted in the thesis from a SA coal perspective, and certainly serve as a very good starting point for further investigations pertaining to CO2, CH4, and coal interactions. However, from the vast literature already published globally, it can be seen that much more needs to be done in terms of addressing coal-CO2-CH4 research from a SA perspective, and indeed CCS in SA in general. It is apparent that the results and sum of the key findings presented in this thesis, are of importance for the selectivity and technical modelling for CO2 onshore coalbed storage and ECBM projects to be implemented in SA in the near future so as to meet the demands required to reduce CO2 emissions in SA as part of the global community. / PH2020

In this work, liquid phase Carbon-thirteen DNP experimental data were collected in a flow transfer system for different mono-substituted aromatic compounds, such as, anisole, nitrobenzene and halobenzenes. These substitute groups covered a wide range of electronic effects from strong electron donating groups to strong electron withdrawing groups. Hammett linear free energy relationship was used to quantitatively study the electronic effect of substituent on the carbon-thirteen DNP enhancement. It was found that the carbon-thirteen DNP enhancements at meta and para positions exhibits a reasonable correlation. A better correlation of carbon-thirteen DNP enhancements with the Hammett inductive factor was observed. A large scalar dominated enhancement at ipso (C-1) position was observed for iodobenzene. This suggests that facile transfer of spin polarization to the C-1 carbon via the highly polarizable iodine atom is possible and the dominate electron transfer mechanism for this system. A model of polarization transfer via spin diffusion of abundant proton spins was examined. The results indicate that it is not important. / Master of Science

The purpose of this study was to determine the economic impact of the College of Eastern Utah on Carbon County. The amount of income that accrued to County households, due to the College's presence in the County, was used as a measure of this impact. The College expenditure flow to the County Has $61,610. Faculty salaries amounted to $318,309, during the 1964-1965 fiscal year. Student expenditure flow to the County was estimated at $636,254. Retail trade and service margins were calculated and applied to the College and student expenditure floor. This calculation indicated an income flow of $122,339, to the County. Wages and salaries paid by the College in the amount of $318,309, was considered as first round income. The total income flow to the County, due to the presence of the College, was $440,648. Relating this amount to job equivalents by dividing the average non-agricultural wage in Carbon County into $440,648, there were 93 jobs created in the County. This is 2.0 per cent of all non-agricultural jobs in the County.

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