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Technical textiles are increasingly being engineered and used in challenging applications, in areas such as safety, biomedical devices, architecture and others, where they must meet stringent demands including excellent and predictable load bearing capabilities. They also form the bases for one of the most widespread group of composite materials, fibre reinforced polymer-matrix composites (PMCs), which comprise materials made of stiff and strong fibres generally available in textile form and selected for their structural potential, combined with a polymer matrix that gives parts their shape. Manufacturing processes for PMCs and technical textiles, as well as parts and advanced textile structures must be engineered, ideally through simulation, and therefore diverse properties of the textiles, textile reinforcements and PMC materials must be available for predictive simulation. Knowing the detailed geometry of technical textiles is essential to predicting accurately the processing and performance properties of textiles and PMC parts. In turn, the geometry taken by a textile or a reinforcement textile is linked in an intricate manner to its constitutive behaviour. This thesis proposes, investigates and validates a general numerical tool for the integrated and comprehensive analysis of textile geometry and constitutive behaviour as required toward engineering applications featuring technical textiles and textile reinforcements. The tool shall be general with regards to the textiles modelled and the loading cases applied. Specifically, the work aims at fulfilling the following objectives: 1) developing and implementing dedicated simulation software for modelling textiles subjected to various load cases; 2) providing, through simulation, geometric descriptions for different textiles subjected to different load cases namely compaction, relaxation and shear; 3) predicting the constitutive behaviour of the textiles undergoing said load cases; 4) identifying parameters affecting the textile geometry and constitutive behaviour under evolving loading; 5) validating simulation results with experimental trials; and 6) demonstrating the applicability of the simulation procedure to textile reinforcements featuring large numbers of small fibres as used in PMCs. As a starting point, the effects of reinforcement configuration on the in-plane permeability of textile reinforcements, through-thickness thermal conductivity of PMCs and in-plane stiffness of unidirectional and bidirectional PMCs were quantified systematically and correlated with specific geometric parameters. Variability was quantified for each property at a constant fibre volume fraction. It was observed that variability differed strongly between properties; as such, the simulated behaviour can be related to variability levels seen in experimental measurements. The effects of the geometry of textile reinforcements on the aforementioned processing and performance properties of the textiles and PMCs made from these textiles was demonstrated and validated, but only for simple cases as thorough and credible geometric models were not available at the onset of this work. Outcomes of this work were published in a peer-reviewed journal [101]. Through this thesis it was demonstrated that predicting changes in textile geometry prior and during loading is feasible using the proposed particle-based modelling method. The particle-based modelling method relies on discrete mechanics and offers an alternative to more traditional methods based on continuum mechanics. Specifically it alleviates issues caused by large strains and management of intricate, evolving contact present in finite element simulations. The particle-based modelling method enables credible, intricate modelling of the geometry of textiles at the mesoscopic scale as well as faithful mechanical modelling under load. Changes to textile geometry and configuration due to the normal compaction pressure, stress relaxation, in-plane shear and other types of loads were successfully predicted. During simulation, particles were moved randomly until a stable state of minimum strain energy in the system was reached; as particles moved upon iteration, the configuration of fibres in the textile changed under constant boundary conditions. Then boundary conditions were altered corresponding to strains imposed on the textile, and the system was iterated again towards a new state of minimum strain energy. The Metropolis algorithm of the Monte Carlo method was adopted in this specific implementation. The method relies on a statistical approach implemented in computational algorithms. In addition to geometrical modelling, the proposed particle-based modelling method enables the prediction of major elements of the constitutive behaviour of textiles and textile reinforcements. In fact, prediction of the constitutive behaviour is integral to the prediction of the meso-scale geometry. Simulation results obtained from the proposed particle-based modelling method were validated experimentally for yarns, single-layer textiles and multi-layer textiles undergoing compaction. Validation work showed that the particle-based modelling method replicates reality very faithfully, and it also showed the suitability of including Gutowski's function along with Hertz' function for representing lateral compaction of yarns. The procedure and results were accepted in final form for publication in a peer reviewed journal [104]. The capability of the proposed particle-based modelling method towards replicating the time-dependent relaxation and reconfiguration of woven textiles subjected to compaction loading was investigated. The capability, which was demonstrated for single and double-layers of plain woven textiles, is intrinsic to the modelling method. The method is unique in the fact that in contrary to work previously reported in the literature, it models the compaction and the relaxation seamlessly in the same simulations and environment. This work is being finalised towards submission for publication in a peer reviewed journal [103]. The proposed particle-based modelling method was also used for modelling in-plane shear in woven textiles. Simulation results were validated experimentally for a single-layer plain woven textile. Validation work showed that the particle-based modelling method reproduces experimental data and published trends very well. A novel algorithm for modelling friction was introduced, leading to results being obtained from a significantly less computationally demanding procedure in these simulations. This work was submitted for publication in a peer reviewed journal [102]. Finally the thesis discusses early work towards the application of the method to carbon fibre fabrics through the description of expansion algorithm (EA) to be used in modelling textiles made of yarns featuring very large numbers of fibres. Furthermore, additional modelling work is presented towards further manufacturing process involving technical textiles, namely textile bending and punching. The latter part is presented as early steps towards future work.

Fibroblast growth factor 2 (FGF2) is a multifunctional protein translated as CUG-initiated, high molecular weight (hi FGF2) or AUG-initiated, low molecular weight (lo FGF2) isoforms with potentially distinct functions. Previous work showed that overexpression of hi- but not lo FGF2 elicited chromatin compaction resulting in cell death, by an intracrine route. A series of studies were undertaken aimed at extending our understanding of the intracrine action of Hi FGF2. Major findings are as follows: a. Hi FGF2 overexpression induces apoptotic cell death, as indicated by increased TUNEL staining, and mitochondrial participation (cytochrome c release to cytosol, rescue of the hi FGF2 phenotype by the anti-apoptotic protein Bcl-2. b. Increased expression of pro-survival signals/proteins that are known to upregulate Bcl-2, such as nuclear Akt; the PIM-1 kinase; and the heat shock protein hsp70, also rescued the hi FGF2-induced phenotype. c. The hi-FGF2 effect was associated with sustained, intracrine, activation of ERK, and was blocked by ERK inhibitors. d. FGF2 isoform specific affinity chromatography followed by mass spectroscopy identified several proteins as potentially interacting with hi FGF2; of these, the p68 RNA helicase and the hsp70 were further confirmed as interacting partners, by co-immunoprecipitation. e. Increased nuclear co-localization, and possibly interaction, between hi FGF2 and overexpressed hsp70 correlated with rescue from hi FGF2 induced cell death. f. Factors associated with cardiac pathology (isoproterenol, angiotensin II, endothelin I) also upregulated endogenous hi FGF2 in cardiac cells in culture. Adriamycin-induced cardiotoxicity in the rat, known to be linked to increased incidence of apoptosis, was also associated with increased endogenous hi FGF2. g. Hi FGF2 is expressed in the human heart (atria) and localizes in both cytosol and nuclei, suggesting a participation in human heart physiology and pathophysiology. Work presented here is consistent with the notion that endogenous hi FGF2 up-regulation may play a role in promoting cell death during prolonged tissue stress and dysfunction. It follows that processes related to hi FGF2 upregulation, hi FGF2-nuclear protein interactions and mechanisms of hi FGF2 induced cell death, represent potential therapeutic targets for modulating cell death.

Although levee deposits make up a significant part of modern and ancient deep-marine slope systems, details of their internal lithological composition and stratal architecture remain poorly documented. At the Castle Creek study area, strata of the Neoproterozoic Isaac Formation (Windermere Supergroup) crop out superbly in a kilometre-scale section through a sinuous deep-water channel-levee system (ICC3). Levee deposits near the outer bend of the channel consist of sandstone-rich (sandstone-to-mudstone ratio of 68:42), medium- to thick-bedded turbidites interstratified with thinly-bedded turbidites. Structureless sandstone (Ta), planar laminated sandstone (Tb), non-climbing ripple cross-stratified sandstone (Tc) and massive and laminated siltstone (Td) are common. Thick beds generally thicken and then thin and fine laterally over about 300 m. Thin-bedded strata, in contrast, thin and fine negligibly over similar distances. In the distal part of the outer-bend levee (up to 700 m laterally away from the channel) strata consist predominantly of thin-bedded Tcd turbidites with a much lower sandstone-to-mudstone ratio (35:65). On the opposite side of the channel, inner-bend levee deposits are mudstone-rich, locally as low as 15:85, and consist mostly of thin-bedded, Tcd turbidites, although thicker-bedded, Ta-d turbidites are more common in the lower part of the section. Lateral thinning and fining of beds is more rapid than their outer-bend counterpart. Levee deposits of ICC3 comprise three stacked decametre-scale upward-thinning and -fining successions. Each is interpreted to record a depositional history consisting of lateral channel migration, levee deposition, channel filling, and distal levee deposition. During the early stage of increasing levee relief it is proposed that the termini of individual beds progressively backstep towards the channel margin resulting in an overall lateral thinning of the stratal profile. This interpretation notably contrasts the common assumption that levee morphology is the result of the vertical stacking of beds that dip. In addition to field studies, laboratory experiments were conducted to determine the depositional threshold of non-climbing ripple cross-stratification, which is common in levee strata of ICC3. It was determined that non-climbing ripples form when bed aggradation rates are less than 0.015 cm/sec, and most probably in flows made up of poorly sorted sediment.

In this study, the relationship between soil suction and shear strength parameters of compacted METU campus clay were investigated at different moisture contents. Soil samples were tested at optimum moisture content (i.e. w=20.8%), at dry side of optimum moisture content (i.e. w=14.8%, 16.8%, 18.8%) and at wet side of optimum moisture content (i.e. w=22.8%, 24.8%, 26.8%). Direct shear tests were performed to measure shear strength parameters (c&#039 / , &amp / #934 / &#039 / ) and soil suctions were measured by filter paper method after direct shear tests. These relationships were also investigated on soaked samples. The trends for suction, angle of internal friction and cohesion, which change on the dry side and wet side of optimum moisture content, were analyzed. The compacted METU campus clay gains granular soil fabric at the dry side of optimum moisture content. As moisture content increases, cohesion increases up to optimum moisture content and then decreases. But angle of internal friction decreases as moisture content increases. Soaking affects the samples more which are on the dry side of optimum moisture content. The soil suction (total suction and matric suction) affects the shear strength, and an increase in soil suction increases the shear strength.

The objective of this thesis was to determine how aspen (Populus tremuloides Michx.) root systems and suckering are affected by decking area (site of log processing and storage) disturbances and seasonal timing of these disturbances. In a field study, summer-built log decks reduced regeneration by half compared to fall-built decks, and if decks were built in the fall, 11 month and 1.5-3 month storage were similar in their impact. A growth-chamber study examined the timing of traffic-induced wounding of the root system and simulated log storage on aspen root systems and suckering. For both summer and winter treatments the combination of root wounding and log storage killed nearly the entire root system and prevented suckering. Root wounding and log storage alone caused a 35-40% reduction in living root mass, carbohydrate reserves, and sucker growth. Sucker numbers were reduced by one half for the winter but were unaffected for the summer.

Insitu cementitious stabilisation is an economical, environmentally sustainable and socially advantageous means of rehabilitating pavements. With the recent availability of a wide range of binders and advanced construction equipment, the characterisation of cementitiously stabilised pavement materials has become the focus of further advancement of this technology. Australian practice has moved towards the use of Indirect Diametric Tensile (IDT) methods for the characterisation of these materials. A draft protocol for the IDT test has been prepared and specifies samples to be compacted by gyratory compactor. This procedure provides for both monotonic and repeated load testing, which aims to measure the material???s strength, modulus and fatigue life. A range of host materials, including a new crushed rock and a reclaimed existing pavement base course, were assessed when stabilised with a General Purpose cement binder as well as with a slag-lime blended binder. Materials were assess for their inherent material properties, Unconfined Compression Strength (UCS), Unconfined Compression modulus, IDT strength and modulus under both monotonic and repeated load. A number of amendments and refinements to the testing protocol were recommended. These included the use of minimum binder contents to ensure the binder was uniformly distributed and to promote heavy binding of the materials to ensure they behaved elastically. It was also recommended that samples be gyratory compacted to a pre-determined sample height to allow a constant density to be achieved. The variability of the test results was examined. UCS results were found to be comparatively as variable as other researchers had reported. IDT strength results contained a similar level of variability, which was considered to be acceptable. Modulus results, both monotonic and repeated load, were found to be five to ten times more variable than strength results, which is a generally accepted trend for modulus testing. Under repeated loading, some challenges with the test protocol were encountered. The primary challenge was obtaining reliable and repeatable diametrical displacement data for modulus calculation. This was partially overcome by the insertion of smooth spacers to prevent the Linear Voltage Displacement Transformer (LVDTs) becoming caught on the sample sides. The achievement of reliable and repeatable IDT modulus results through improved displacement measurements should be the focus of future research efforts in this area.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2003. / Härtill 4 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2004. / Härtill 8 uppsatser.

Thesis (MScFor)--University of Stellenbosch, 2007. / Bibliography. Also available via the Internet.