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Geopolymers, a class of largely X-ray amorphous aluminosilicate binder materials, have been studied extensively over the past several decades, but largely from an empirical standpoint. The primary aim of this investigation has been to apply a more science-based approach to the study of geopolymers, including introducing a variety of mathematical modelling techniques to the field. The nanostructure of geopolymers is analysed via an extensive literature review, and conclusions regarding the presence and role of crystallinity within the geopolymer structure are drawn. Si/Al ordering within the tetrahedral aluminosilicate gel framework is described by a statistical thermodynamic model, which provides an accurate representation of the distribution of Si and Al sites within the framework as well as physically reasonable values for the energy penalty associated with ordering violation. Framework and extraframework structure within the geopolymer binder are also described by the pair distribution function (PDF) technique, whereby synchrotron X-ray scattering data are converted via a Fourier transform-based method into real-space structural data on an Ångstrom length scale. Real-space Rietveld analysis of geopolymers crystallised at high temperature is used to back-calculate and analyse the original geopolymer structure, and the primary change in very short-range structure from the as-synthesised geopolymer to the high-temperature crystalline product is observed to be a shift in the location of the extraframework charge-balancing cation.

The optimisation of strength and power through resistance training has been the source of debate amongst health professionals and researchers for many years. As resistance training involves the repeated activation and contraction of skeletal muscles, continuous training will ultimately result in a failure to sustain the training intensity especially when performing multiple sets and / or repetitions. Therefore the prescription of rest periods within the training session becomes an important consideration. Relatively short rest periods (60-90 seconds) have been traditionally used for the maximal strength adaptation involving increases in the cross-sectional area of the muscle, whereas longer rest periods (180-300 seconds) have traditionally been used for the maximal strength adaptation involving enhancement of neural function and maximal power adaptation. However, there is very little scientific evidence to support these current practices. In fact, the effect of different rest periods on maximal strength and power development has received very little research attention. Additionally, research that has been conducted in this area has been typified by a number of methodological inconsistencies, within and between studies, which confound scientific understanding. Although traditionally resistance training has employed continuous training schemes with inter-set rest periods, intra-set rest training methods which distribute rest intervals between groups of repetitions have also been investigated. It has been theorised that the short rest periods within the training set allow partial resynthesis of the intramuscular phosphocreatine stores, potentially allowing an athlete to increase their training volume by training at high intensities for longer durations, or performing additional repetitions (Berg, 2003). This is thought to lead to an increased exposure of the muscle to the kinematic and kinetic stimuli thought important for strength and power adaptation whilst minimising performance-inhibiting metabolic accumulation and substrate depletion. However, research into intra-set rest training schemes is still in its infancy, and many of the theories surrounding intra-set rest training are currently unsubstantiated. It is thought that examinations of the acute kinematic, kinetic and blood lactate profiles of continuous and intra-set rest training schemes may enhance scientific understanding regarding the efficacy of intra-set rest training. The purpose of this study was to investigate and compare the acute kinematic, kinetic and blood lactate responses to continuous and intra-set rest loading schemes. Nine male subjects performed an isoinertial Smith machine bench press task (6RM load) with a continuous loading scheme (CONT), an intra-set rest loading scheme equated by total rest time, volume and load (ISRV) and an intra-set rest loading scheme equated by total rest time and load (ISRR). The order of the loading schemes was assigned in a block randomised order with a minimum of 48 hours recovery between each testing session. Attached to the bar of the Smith machine was a linear position transducer that measured vertical displacement with an accuracy of 0.01cm. Displacement data was sampled at 1000Hz and collected by a laptop computer running custom built data acquisition software. Finger prick blood lactate samples were taken from the non-dominant hand using sterile techniques at the following time points: pre-exercise (Pre), immediately post-exercise (P0), five (P5), fifteen (P15) and thirty minutes (P30) post exercise. Blood glucose samples were taken pre-exercise only. It was observed that manipulating the rest period, by increasing the frequency but decreasing the length of each rest period, did not significantly influence the kinematics and kinetics associated with resistance training, but did have an effect on the post-exercise blood lactate response when the load, rest duration and training volume was equated (ISRV). This finding may be of practical significance if fatigue is important in strength development or conversely if power training needs to be performed with minimal fatigue. It was also observed that increasing the frequency of the rest period enabled the subjects to perform a greater number of repetitions (ISRR), resulting in significantly greater kinematics, kinetics and blood lactate accumulation. It may be speculated, therefore, that ISRR training may offer a superior training stimulus for the development of maximal strength and hypertrophy than CONT training methods, as ISRR loading increased the exposure of the muscle to the kinematic, kinetic and metabolic stimuli thought important for the development of these qualities.

Radical polymerisation (RP) has for many years been an industrially important process, and the kinetics of the process remains an active area of research. As polymerisation proceeds, converting monomer (small molecules) into polymer (long chain molecules), chemical species of a variety of chain lengths are produced. Recent work has pointed toward the fact that rate coefficients for polymerisation reactions (specifically, termination and propagation) are often dependent on the chain-length of the reacting species. The focus of this thesis is to study the effects of chain-length-dependent reactions on the kinetics of RP, by using computer-based modeling and comparing the results of such modeling with experimental data. This enables the understanding of otherwise inexplicable trends and the building of more mechanistically detailed and accurate models for RP kinetics. In Chapter 2, a new model for termination is developed, connecting observations and analyses of termination kinetics at short chain lengths (particularly small molecule studies) with other observations and analyses at long chain lengths (conventional RP kinetics studies) in order to construct a model for termination that is shown to be capable of coherently describing termination kinetics at any chain length. In Chapter 3, this new model for termination is tested at short chain lengths on polymerisations with large quantities of added chain transfer agent. With the inclusion of chain-length-dependent propagation in the model, the model for termination is validated. Chapter 4 is aimed at extending an existing reduced-variable, compact, 'universal' description of steady-state RP kinetics by incorporating all known chain-length dependent reactivities. This both increases computational efficiency over other approaches and provides easily evaluated, approximate analytical expressions for RP kinetics. This foundational theory is applied in Chapter 5 to reach a deeper understanding of the behaviour of the model, and show how experimental data may readily be analysed to extract information about chain-length-dependent termination kinetics. In Chapter 6, the effect of chain-length dependent reactivities on the important technique of single-pulse pulsed-laser polymerisation is investigated, and this technique is validated as the best experimental method for investigation of termination kinetics. In general, a central result of this thesis is that chain-length-dependent reactivities, when acknowledged and properly incorporated into models, can explain many phenomena in RP kinetics which otherwise seem difficult to account for. No exceptions to this principle have been found.

Thesis (Ph. D.)--Ohio University, November, 1993. / Title from PDF t.p.

Thesis (M.S.)--Rutgers University, 2007. / "Graduate Program in Pharmaceutical Science." Includes bibliographical references (p. 69-71).

Thesis (Ph.D.)--Drexel University, 2007. / Includes abstract and vita. Includes bibliographical references.

Thesis (M.S.)--Ohio University, November, 2000. / Title from PDF t.p.

Diss. (sammanfattning) Uppsala : Univ., 2004. / Härtill 5 uppsatser.

Thesis (Ph. D.)--University of Adelaide, Dept. of Chemical Engineering, 1990. / Includes bibliographical references (leaves 168-174).