The published literature on the strength and structural changes occurring during and after hot working of AI5I316 and 304 austenitic stainless steels are reviewed. Isothermal plane strain compression tests have been carried out with the purpose of determining relationships to describe the kinetics of static recrystallization, the recrystallized grain size, the isothermal grain growth rate and the strength during hot rolling of AISI316 steel. The kinetics of static recrystallization were also studied in samples tested in axisymmetric compression, or hot rolled. The effect on the kinetics of static recrystallization of the strain distribution in samples tested in plane strain compression was analysed. The set of equations determined for 316 steel wasused in a computer model modified from the one developed by Leduc (1980) for simulation of hot rolling loads and microstructural evolution. Partially recrystallized microstructure was generated in a laboratory hot rolling mill and was reasonably simulated by the use of the computer programme. Non-isothermal plane strain compression tests were carried out for direct simulation of laboratory hot rolling results. Comparison between experimental hot rolling and plane strain compression data has shown reasonable levels of agreement in the microstructural simulations undertaken in the present work. The mean plane strain strengths from non-isothermal plane strain compression tests were higher than the ones from hot rolling. This may have been caused by thermal gradients inside the sample being tested.

No description available.

No description available.

Surgery to correct cam femoroacetabular impingement (FAI) is increasingly popular. Despite this, no known study has used motion analysis and ground reaction forces to quantify the outcome of surgery for FAI. The goal of this study was to compare the preoperative and postoperative lower-extremity joint kinematic and kinetic measurements of cam FAI patients during activities of daily living with use of a high-speed motion capture system and force platforms. We hypothesized that the lower-extremity joint mechanics of FAI patients during level walking and maximal squatting would resemble more those of healthy control subjects, after surgery. Ten patients with unilateral symptomatic cam FAI, who underwent corrective surgery using an open or combined technique, performed walking and maximal depth squatting trials preoperatively and postoperatively. Thirteen healthy control subjects, matched for age, sex and body mass index, provided normative data. Results showed that postoperatively, FAI patients had reduced hip ROM in the frontal and sagittal planes, produced smaller peak hip abduction and external rotation moments, and generated less peak hip power compared to the control group during level walking. During maximal squatting, postoperative FAI patients squatted to a greater depth, and had larger knee flexion and ankle dorsiflexion angles, as well as the sum of all joint angles of the affected limb at maximal depth compared to the preoperative values. The lower-extremity joint and pelvic mechanics of FAI patients did not fully return to normal after surgery. Although surgery seemed to reduce hip pain and restore a normal femoral head-neck offset, it further impaired muscle function as a result of muscle incisions. More research is needed to determine the effects of muscle incisions, which could help improve surgical techniques and develop better rehabilitation programs for FAI patients.

This thesis describes the research conducted by t he author in completion of a Doctor of Philosophy in the Centre for Advanced Macromolecular Design(CAMD), Univcrsity of New South Wales (UNSW) , Sydney, Australia; under the supervision of Professor Christopher Barner-Kowollik and Doctor Michelle L. Coote (Australian National University). The research has led to the creation of new knowledge in the fields of free radical polymerisation and chemical kinetics. Research was conducted in two main thrusts: (1) investigation into the governing kinetic processes behind star polymer synthesis via what has become known as a reversible addition fragmentation chain transfer (RAFT), R-group approach and (2) an entirely new mode of living free radical (LFR) polymerisation which has been named thioketone mediated polymerisation (TKMP). In the first broad area of the described research, a novel kinetic modelling scheme has been developed in which only the reactions of a single arm star are simulated explicitly. Subsequently, the molecular weight distributions (MWDs) arising from the single arm star simulation are convolved, using probabilistic calculations, to generate the MWD appropriate to a multi-arm star polymerisat ion bearing t he same kinetic parameters as the single arm one. This model is validated against experimental data, enabling, for the first time, the use of rigorous theoretical reasoning to distill a set of synthetic guidelines for star polymer synthesis via a RAFT, R-group approach. Subsequently, the product spectra resulting from RAFT, R-group approach polymerisations of para-acetoxystyrene have been analysed via mass spectrometry. This has led to direct evidence for many of the complex species whose existence had, up until this point, been inferred from gel permeation chromatography (GPC) measured MWDs. The menagerie of species identified includes, but is not limited to, star-star couples, initiator fragment terminated stars, initiator fragment terminated star-star couples and linear chains -- both living and terminated. Using a kinetic model devised specifically for application in mass spectrometry analysis, the experimentally observed abundances of each of the above species have been compared to t hose predicted by simulation. The qualitative agreement between the predicted and observed abundances has provided additional evidence that t he proposed mechanism for RAFT, R-group approach polymerisations is correct and operative. Further, it seems unlikely that significant, undiscovered kinetic phenomena exist. Due to (a) long simulation times encountered using the state of the art, commercial partial differential equation solver for polymerisation kinetics (i.e. PREDICI, Computing in Technology (CiT), GmbH; see http://www.cit-wulkow.de) and (b) the limited flexibility this software provides with respect to the types of chemical species that can be simulated, fundamental research has been conducted into the kinetic Monte Carlo method to (i) examine fundamental aspects of this simulation approach; (ii) determine the maximum speed attainable through a combination of optimisations including run-time generation of problem specific code and parallelisation; and, therefore (iii) find out what the potential of this method may be as a replacement for t he existing methods. In terms of speed, the developed code outperforms previous Monte Carlo benchmarks in the literature by a factor of 2.6 and the latest developments in the commercial tool, PREDICI that took place during the author's Ph.D. candidature give it similar performance to the herein described Monte Carlo code; however, the latter is required to run on multiple processors in order to compete with the serial algorithm implemented in PREDICI. The Monte Carlo method does, however, provide complete freedom with respect to the chemical species whose kinetics can be simulated, allowing for complex species with many chain lengths and, in principal copolymer compositions and branched structures. The Monte Carlo approach is the method of choice for these types of simulations and for the first time competes with the commercial tool in terms of speed. In the second broad area of the described research, an experimental investigation has been conducted into the applicability of thioketones, S=C (R1) (R2), as mediating agents for free radical polymerisations. The compound di-tert-butyl thioketone (DTBT), S=C-(C(CH3)3)2, has been chosen as a model reagent and this, when incorporated into a free radical polymerisation of styrene has led to a linear increase of the average molecular weight as conversion of monomer into polymer takes place - demonstrating control. A reversible radical trapping mechanism has been proposed and evidence for this has been provided in the form of an ab initio calculation of the equilibrium constant for the trapping of a styryl dimer radical by DTBT. This equilibrium constant was approximately K = 105 L mol-1 and is close to the value which is expected on the basis of the experimental results. To aid future experimental investigations intoTKMP, a quantum chemical survey has, been conducted with the aim of discovering the radical affinities of a large range of thioketones. It has been demonstrated that there is ample scope within this class of compound for potent radical trapping - far above that of DTBT. The affinities of various thioketone substrates for radicals have been understood in terms of the radical stabilising and thioketone destabilising effect of the two substituents R1 and R2 on, respectively, the adduct radical, R-S-C???(R1) (R2), and the parent thioketone. All results appearing in this thesis have been published previously in peer-reviewed scientific journals.

Typescript / Includes 4 reprints of articles by the author / Includes bibliographical references / 112 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Physical and Inorganic Chemistry, 1965

Air injection is an enhanced oil recovery (EOR) process in which compressed air is injected into a high temperature, light-oil reservoir. The oxygen in injected air is intended to react with a fraction of reservoir oil at elevated temperature resulting in in-situ generation of flue gases and steam, which, in turn, mobilize and drive the oil ahead towards the producing wells. To understand and determine the feasibility of the air injection process application to a given reservoir, it is necessary to understand the oxidation behaviour of the crude oil. The aim of this study is to screen two Australian light-oil reservoirs; Kenmore Oilfield, Eromanga Basin, and another Australian onshore oil and gas field “B”* for air injection EOR process, and to understand the oxidation reaction kinetics during air injection. It is carried out by the thermogravimetric and differential scanning calorimetric (TGA/DSC) studies to investigate the oxidation mechanism during an air injection process. There has not been any TGA/DSC evaluation conducted to date with regard to air injection for Australian light-oil reservoirs. A series of thermal tests was performed to investigate the oxidation behaviour of two selected reservoirs in both air and oxygen environments. The first step undertaken in this study is thermogravimetric and calorimetric characterization of crude oils to (i) identify the temperature range over which the oil reacts with oxygen, (ii) examine the oxidation behaviour within the temperature identified, and (iii) evaluate the mass loss characteristics during the oxidation. This study also examines the effect of pressure on oxidation at different temperature ranges and the effect of core material (rock cutting) on oxidation reactions. Finally, kinetic data are calculated from thermal tests results by literature described method. Kenmore and Field B both are high temperature and light-oil reservoirs. Hydrocarbon distribution indicates that Kenmore oil contains 84 mole% of lower carbon number n-C₅ - n-C₁ ₃ compounds. Reservoir B oil also contains a substantial amount (i.e., 95 mole %) of lower carbon number n-C₄ - C₁ ₉ compounds. These lighter components may contribute favourably towards efficient oxidation. However, a high content of lighter ends in the oil may also result in a lower fuel load. Generally, low molecular weight oil gives fastest mass loss from heavy crude oil. Thermal tests on Kenmore oil showed two distinct exothermic reactivity regions in temperatures of 200-340°C and 360-450°C, with a 85-95% mass loss when the temperature reached 450°C. Reservoir B oil showed a wider exotherm range between approximately 180°C-260°C with 90-95% mass loss by temperature 350°C. In the high temperature range, the combustion reactions of Reservoir B oil are weaker than Kenmore oil. This is due to insufficient fuel available for oxidations in high temperature region. Reservoir B oil has more chance to auto ignite; but it has less sustainability to the ignition process. Based on the sustainability study of the ignition process, between the two reservoirs, Kenmore is the better candidate for air injection. Based on the thermal tests, it is concluded that for light-oil oxidation, vaporization is the dominant physical phenomenon. At low temperature range, the addition of the core material enhanced the exothermic reactions of the oil. The elevated pressure accelerated the bond scission reactions. The largest amount and highest rate of energy generation occurred at the low temperature range. Activation energies (E) are calculated from thermal test results and the value of ‘E’ in oil-with-core combined tests is smaller than the oil-only test. This indicates that the rock material has a positive impact on the combustion process. Moreover, the compositional analysis result addresses the composition of oils, which can help understand the oxidation behaviour of light-oils. * For confidentiality reasons, the field name is coded as Field B at the request of the operating company. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1381084 / Thesis (M.Eng.Sc.) -- University of Adelaide, Australian School of Petroleum, 2010

Air injection is an enhanced oil recovery (EOR) process in which compressed air is injected into a high temperature, light-oil reservoir. The oxygen in injected air is intended to react with a fraction of reservoir oil at elevated temperature resulting in in-situ generation of flue gases and steam, which, in turn, mobilize and drive the oil ahead towards the producing wells. To understand and determine the feasibility of the air injection process application to a given reservoir, it is necessary to understand the oxidation behaviour of the crude oil. The aim of this study is to screen two Australian light-oil reservoirs; Kenmore Oilfield, Eromanga Basin, and another Australian onshore oil and gas field “B”* for air injection EOR process, and to understand the oxidation reaction kinetics during air injection. It is carried out by the thermogravimetric and differential scanning calorimetric (TGA/DSC) studies to investigate the oxidation mechanism during an air injection process. There has not been any TGA/DSC evaluation conducted to date with regard to air injection for Australian light-oil reservoirs. A series of thermal tests was performed to investigate the oxidation behaviour of two selected reservoirs in both air and oxygen environments. The first step undertaken in this study is thermogravimetric and calorimetric characterization of crude oils to (i) identify the temperature range over which the oil reacts with oxygen, (ii) examine the oxidation behaviour within the temperature identified, and (iii) evaluate the mass loss characteristics during the oxidation. This study also examines the effect of pressure on oxidation at different temperature ranges and the effect of core material (rock cutting) on oxidation reactions. Finally, kinetic data are calculated from thermal tests results by literature described method. Kenmore and Field B both are high temperature and light-oil reservoirs. Hydrocarbon distribution indicates that Kenmore oil contains 84 mole% of lower carbon number n-C₅ - n-C₁ ₃ compounds. Reservoir B oil also contains a substantial amount (i.e., 95 mole %) of lower carbon number n-C₄ - C₁ ₉ compounds. These lighter components may contribute favourably towards efficient oxidation. However, a high content of lighter ends in the oil may also result in a lower fuel load. Generally, low molecular weight oil gives fastest mass loss from heavy crude oil. Thermal tests on Kenmore oil showed two distinct exothermic reactivity regions in temperatures of 200-340°C and 360-450°C, with a 85-95% mass loss when the temperature reached 450°C. Reservoir B oil showed a wider exotherm range between approximately 180°C-260°C with 90-95% mass loss by temperature 350°C. In the high temperature range, the combustion reactions of Reservoir B oil are weaker than Kenmore oil. This is due to insufficient fuel available for oxidations in high temperature region. Reservoir B oil has more chance to auto ignite; but it has less sustainability to the ignition process. Based on the sustainability study of the ignition process, between the two reservoirs, Kenmore is the better candidate for air injection. Based on the thermal tests, it is concluded that for light-oil oxidation, vaporization is the dominant physical phenomenon. At low temperature range, the addition of the core material enhanced the exothermic reactions of the oil. The elevated pressure accelerated the bond scission reactions. The largest amount and highest rate of energy generation occurred at the low temperature range. Activation energies (E) are calculated from thermal test results and the value of ‘E’ in oil-with-core combined tests is smaller than the oil-only test. This indicates that the rock material has a positive impact on the combustion process. Moreover, the compositional analysis result addresses the composition of oils, which can help understand the oxidation behaviour of light-oils. * For confidentiality reasons, the field name is coded as Field B at the request of the operating company. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1381084 / Thesis (M.Eng.Sc.) -- University of Adelaide, Australian School of Petroleum, 2010

Thesis (Ph.D.)--McMaster University, 2006. / Supervisor: William J. Garland. Includes bibliographical references (leaves 139-148).

Thesis (Ph.D.)--University of Adelaide. Dept. of Chemical Engineering, 1979.