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Submitted in fulfillment of the requirements for the Master of Engineering Degree, Durban University of Technology, Durban, South Africa, 2018. / Ethanol and butanol obtainable through fermentation of lignocellulose biomass have become promising alternative feedstock for production of fuels as they are biodegradable and sustainably regenerated via the photosynthesis cycle. The properties of hydrocarbons produced through alcohol conversion closely resemble those of gasoline. Catalytic systems are reported to play a vital role during alcohol conversion to hydrocarbons. In this study ethanol and butanol were used as a feedstock for production of hydrocarbons over Fe, Zn and Ni catalyst systems supported on zeolite ZSM-5 (Zeolite Socony Mobil-5) and activated carbon (AC). X- Ray Diffraction (XRD), Scanning Electron Microscope (SEM) coupled with Energy- dispersive X-ray spectroscopy (EDS) and Brunauer, Emmet, and Teller (BET) analyses were employed for catalyst characterization. XRD patterns confirmed the success of metal doping on ZSM-5 and activated carbon supports. Major peaks at 7.96° and 23.97° corresponding to ZSM-5 crystals were observed in ZSM-5, and AC was found to be amorphous. Impregnation with metals reduced the crystallinity of ZSM-5 supported catalysts. Whereas SEM analysis showed that catalysts supported on ZSM-5 exhibited irregular shapes and catalyst supported on activated carbon exhibited disordered structures. The BET analyses confirmed that the surface areas of promoted catalysts decreased after metal doping. Evaluation of the catalysts were carried out in a ½ inch stainless steel reactor at 400 °C and atmospheric pressure with a weight hourly space velocity (WHSV) of 2.5 h-1 (g feed)/ (g catalyst). The ZSM-5 support performed better than activated carbon support. More than 90% conversion was achieved over catalysts supported on ZSM-5. Production of hydrocarbons over catalysts supported on activated carbon were as a result of the active component. Conversion of feedstock was observed to produce more benzene, toluene and xylene (BTX) compounds with an increase in butanol content. 100% conversion was achieved with pure butanol and not more than 99.86% conversion was achieved with pure ethanol. Catalyst systems supported on HZSM-5 and activated carbon were successfully synthesised. Ethanol, butanol and ethanol-butanol mixtures were successfully converted to liquid hydrocarbons and the conversion was greater than 90%. On the promoted catalysts, production of BTX were suppressed and various metals were observed to perform differently. / M

Research indicates that parental involvement in transition planning for adolescents with disabilities is associated with more successful adult outcomes as well as higher family well-being and parental satisfaction Given that parents invest more time and energy into transition planning for their child with a disability than one without, and that parental involvement is associated with transitional success, it is important to understand parental experiences during transition so that the best and most comprehensive support can be provided to them. This qualitative study examined how parents of youth with disabilities describe their own, personal experiences of their son or daughter’s transition to adulthood. A conceptual model was developed to describe the tension between parents’ preparedness for and their emotions regarding the transition process. This tension ultimately contributes to a sense of uncertainty about their son or daughter’s future.

Lower-extremity amputees face numerous challenges when returning to daily activities. Amongst these challenges is the ability to safely and dynamically transition from one locomotor state to another. Switching between level-ground, ramp, and stair locomotion poses an increased risk as lower-extremity functionality is compromised. Powered prosthetics have been proposed as a solution to this problem. Hypothetically, powered prosthetics would be able to return full functional to the amputated limb. The most common and successful source of information used in algorithms for lower-extremity prosthetics has been electromyography. However, in practice, amputees remain unable to easily actuate the mechanized joints of powered prostheses. Therefore, the current project aimed to identify myoelectric activation differences in lower-extremity musculature during the gait cycles preceding locomotor transition in able-bodied, trans-tibial, and trans-femoral subjects to assist efforts in developing robust classification algorithms for locomotor transitions. Analysis of electromyography was completed to determine if there were periods of activation where classification algorithms could utilize differences in myoelectric activation to appropriately control joint actuation in a subset of eight transitions that included level-ground locomotion and switching to either ramp or stair locomotion and vice versa. Ramp transitions were fundamentally similar to level-ground locomotion and elicited no differences in myoelectric activation. Stair transitions were found to alter muscle activation patterns in able-body and trans-tibial subjects. Trans-femoral subjects differentiated from able-bodied and trans-tibial subjects due to increased recruitment pattern variability. These patterns are distinct and may suggest individual learning patterns within the trans-femoral amputee population. Further investigation of these patterns may be warranted. Findings within able-bodied and trans-tibial subjects suggest common transition based differences within each respective population. Trans-tibial classification algorithms may be developed to utilize this information, using schemes that are focused on important areas during the gait cycle.

Le sujet central de la thèse concerne la Roumanie postcommuniste, dont la transition est analysée àla lumière des théories de la transition démocratique. Prise dans la vague des transitionsdémocratiques qu’ont connues les pays de l’Europe Centrale et Orientale après 1989, la Roumanieest le seul pays qui a vécu un changement violent de régime ; elle est aussi celui qui a connu latransition démocratique la plus longue et la plus sinueuse de la région. La thèse présente unetypologie générale des théories de la transition démocratique, élaborées avant et après 1989. Lespremières tentent de dégager les facteurs de transition, avec des approches centrées, soit sur lesstructures, soit sur les acteurs. Les secondes insistent sur les facteurs d'incertitude propres à toutetransition et aussi sur les choix rationnels des acteurs. La confrontation du cas roumain auxthéories de la transition constitue un test de validité des différentes approches et souligne, en toutehypothèse, les spécificités de l'itinéraire suivi par la Roumanie pour sortir du régime communiste.La thèse, qui éclaire à la fois la genèse et le cheminement complexe de la transition roumaine,souligne les limites des théories de la transition démocratique, celles d'avant 1989 comme cellesd'après 1989, dans l'explication du processus transitionnel roumain, démontrant par là lacomplexité du cas roumain. / The central issue of this thesis concern post communist Romania and deals with the Romaniandemocratic transition regard to democratic transition theories. Part of the democratic transitionwave that experimented counties of Central and Eastern Europe, Romania is the only country toexperiment a violent regime change and a democratic transition known to be the longest and themost twisting. The thesis presents a general typology of democratic transition theories existingbefore and after 1989. The first theories attempt to identify the transition’s factors with centredapproaches either on structures or on actors. The latter emphasises the uncertainty inherent to anytransition, as well as on the actor’s rational choice. The confrontation of the Romanian case to thetransition theories is a test of the validity of different approaches and underlines the specific of theroute that Romania followed to escape communism. The thesis, which stresses both the genesisand the complex process of Romania’s transition, highlights the limitations of democratictransition theories, those before 1989 as well as those after 1989 in explaining the Romaniantransition process, thus demonstrating the complexity of the Romanian case.

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The x-ray structures of several alkyl halide, alkyl dihalide, and hydrogen adducts to pyrazolyl-bridged diiridium complexes [special characters omitted] are determined. The diiridium (bis-pyrazolyl) core of these complexes enables contact between the two centers so that metal-metal bond formation may occur, exemplified by a short iridium-iridium distance of 2.78(I) A in the diiridium(II) complex [special characters omitted]. Oxidation mechanisms are postulated based on reaction kinetics. The oxidative addition of methyl iodide to [special characters omitted] is observed to occur by a two-step mechanism, where a high positive ΔS‡ term may be due to a highly ordered intermediate. This is proposed as evidence for an [special characters omitted] addition, where coordination of the alkyl halide is followed by halide dissociation and migration to a trans diaxial coordination site. Different kinetics of the reaction are observed in THF and benzene, which is also attributed to a polar [special characters omitted] intermediate. Occupation of the 3,3’ and 5,5’ positions of the pyrazolyl ligand decreases the reaction rate by an order of magnitude or greater, which indicates steric inhibition of the reaction by the bridging ligands. Experimental evidence for a competing light-induced reaction that corresponds to a radical-chain mechanism rather than the dark [special characters omitted] reaction is also presented. Oxidative isomerization of an iodo (iodomethylene) complex to the methylene-bridged isomer is determined to be an intramolecular process based on isotope labelling experiments and kinetics. Negligible isomerization to the bridging methylene complex under ambient conditions is attributed to coordinative saturation; the stability of [special characters omitted] is likewise due to coordinative saturation of the metal centers. The addition of hydrogen or hydride to [special characters omitted] is possible through a number of synthetic routes, but the stereochemistry of the iridium(II) hydrido complexes is such that the metal-hydride and iridium-iridium bonds do not occupy coordination sites trans to each other: it is proposed that the strong σ-trans effect of the hydride induces structural rearrangements in substitution reactions so that stereochemistry of parent complexes is not conserved. This is demonstrated by the x-ray structures of [special characters omitted]. The hydride ligand promotes nucleophilic attack on an electron-rich iridium center; thus water and other Lewis bases are found to react with the cationic diiridium hydride complex [special characters omitted]. / Graduate

The ligands of the ten-membered series, [10]-aneS3, [10]- aneS2N, [10]-aneSN2 and the macrobicyclic ligand - 1,4-bis(1-aza- 4,8-dithia-4-cyclodecyl) ethane, and their transition metal complexes were successfully synthesised. Chromium (III) complexes of the homoleptic hexaaza ligands [18]-aneN6 and [20]-aneN6 were synthesised, structurally characterised and their spectral properties studied. Bis complexes of Ni(II) with [10]-aneS3, [10]-aneS2N and [10]-aneSN2 were octahedral as is evident from their crystal structures. The esr spectra of the corresponding Ni(III) complexes are characteristic of a low spin d7 ion in a compressed octahedral coordination in the complex based on [10]-aneS2N and an elongated octahedral coordination in the complexes based on [10]-aneSN2 and [10]-aneS3. The spectral and electrochemical properties of the various Ni(II) complexes are compared with each other. The redox reactivity of the Ni(II) complex based on [10]-aneS3 was studied. The synthesis of a macrobicyclic ligand is described. The Ni(II)complex of the macrobicyclic ligand is a distorted octahedron and the esr spectrum of the Ni(III) complex is characteristic of a low spin d7 ion in a compressed geometry. The covalency parameter K, and the energy separation between the low spin ground state and the first excited high spin state were determined from the esr and the electronic spectra of the Ni(III) complex. Two isomers for the Pd(II) bis complexes of [10]-aneS2N were obtained and characterised by X-ray methods and nmr spectroscopy. Evidence for the formation of a high spin Pd(II) octahedral species has been provided for the first time. Oxidation of the Pd(II) complex is metal centered and the esr spectra of the Pd(III) complexes are characteristic of a low spin d7 PdS4N2 core. Fe(II), Fe (III), Co(II), Co(III), Ni (II) and Pd(ll) bis complexes of the ligand [10]-aneS3 were synthesised and characterised by elemental analysis, nmr and esr spectroscopies, where appropriate, and their spectral and electrochemical properties studied. The crystal structures of Fe(II), Co (II) and Ni(II) bis complexes of [10]-aneS3 were octahedral with three S atoms from each of the thioether ligands coordinated to the central metal ion. The esr spectra of the Fe(III) bis complexes of [9]-aneS3 and [10]-aneS3 were characteristic of a low spin d5 complex ion. The ligand field distortion parameters were obtained from the electronic and esr spectra and the energies of the Jahn-Teller splitting were estimated. The Co(II, bis complex of [10]-aneS3 is low spin. The half-wave potentials due to the [special characters omitted] and [special characters omitted] couples were obtained by cyclic voltammetry. The electron self exchange rate constant for the [special characters omitted] and the [special characters omitted] couples were determined by the 59Co nmr line broadening technique for the first time. The self exchange rate constant for the [special characters omitted] couple was determined by the 'H nmr line broadening technique. The crystal structure of the Pd(II) bis complex of [10]—aneS3 is essentially square planar with significant interactions from the axial S atoms. This complex is fluxional as is evidenced in the variable temperature nmr spectra. / Graduate

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