Pultruded, fibre reinforced, polymeric composites are now being used in a wide range of structural engineering applications, due to their high strength to weight ratios and resistance to environmental conditions. However, such materials posses a relatively low shear modulus in relation to their axial and flexural moduli. This can result in shear deformation constituting a significant proportion of the total deformation and a reduction in buckling loads for various modes of instability. An experimental and theoretical study of the influence of shear deformation on the flexural and torsional stiffnesses and various modes of instability of pultruded polymeric bars of open cross-section is therefore presented. Theories for the bending and warping torsional response of pultruded, fibre reinforced polymeric bars of open cross-section, excluding and including the influence of shear deformation, are presented. Full section bending mechanical properties of several pultruded beams are determined using a static testing apparatus and a wide variety of span configurations. Full section warping torsional mechanical properties of several pultruded bars are determined using a new testing apparatus, capable of applying a torque to any cross-section along a bar, whilst maintaining the bars lateral position. Theories for the flexural, torsional and lateral instability of pultruded, fibre reinforced polymeric bars of open cross-section, excluding and including the influence of shear deformation, are developed and presented. Parametric studies of the influence of shear deformation in the flexural, torsional and lateral instability of various pultruded bars of open cross-section are also presented. The experimental and theoretical studies indicate that shear deformation reduces significantly the non-uniform bending stiffness of pultruded polymeric bars, but that its influence on the non-uniform and restrained warping torsional stiffness is practically negligible. Shear deformation has also been found to result in a significant reduction in flexural, torsional and coupled flexural-torsional or lateral buckling loads.

This thesis,firstly, studies the impact of financial liberalization and political instability on economic growth and quantitatively examines the relative importance of the identified underling reasons of Argentine riddle by using an innovative econometric methodology and unique data set: it presents power ARCH estimates for Argentina from 1896 to 2000. The main results show that the long-run effect of financial liberalization on economic growth is positive while the short-run effect is negative, albeit substantially smaller. The political instability effects are substantially larger in the short-run than in the long-run. We also investigate potential mechanisms for the effects of financial liberalization and political instability on economic growth: direct impact or happening through the variation of growth volatility. Our results also suggest that financial development, trade openness and political instability are the main factors to explain the Argentine decline. Furthermore, real business cycle variability - growth relationship and the link between inflation and its uncertainty are investigated by using monthly data of four Asian countries/regions (Japan, South Korea, Singapore and Taiwan) and parametric power ARCH methodology to proxy uncertainty. We fnd that more uncertainty about output leads to a higher rate of growth in three of the four countries/regions and the form of the uncertainty matters. Output growth reduces its uncertainty in all countries/regions via inflation uncertainty except Singapore. For all countries/regions, inflation significantly raises inflation uncertainty as predicted by Friedman. On the other hand, increased uncertainty affects inflation positively in Japan and Singapore, which support the Cukierman-Meltzer hypothesis. We find a negative sign for Taiwan which is in accordance with the Holland hypothesis when error term was normally distributed, however, this result is not statistically significant when the student-t distribution is applied. Interestingly, South Korea’s data reveals a positive sign initially, however, it turns around when a structural dummy is incorporated. This dramatic outcome in favour of the Holland hypothesis, and chimes in with Dueker and Kim (1999), who claim that the inflation was strictly controlled by the South Korean monetary authority. In addition, this thesis investigates two-way causal relationships between spread, volatility and volume in the FTSE100 stock index over the period from 1992 to 2004 by using bivariate AR-FI-GARCH model and multiple measurements of risk and spread. The measurements of the spread include relative bid-ask spread, effective bid-ask spread, the inventory cost component of the bid-ask spread and the information cost component of the bid-ask spread. Risk is proxied by two measurements of price volatility: the close-to-close volatility and the range-based volatility. We also take the impact of electronic trading into account. Our results suggest that the spread and volume are positively impacted by volatility simultaneously. In addition, both volatility and volume are negatively affected by the spread. Furthermore, we find that the inventory cost component of the spread has a negative effect on volatility, in contrast, the information component of the spread positively impacts volatility. These results support the argument that speculation generates volatility in the market and higher transaction costs bene t stability of the market.

This thesis is dedicated to the study of the interaction between a gas jet and a liquid film on a moving surface. This flow configuration corresponds to the gas-jet wiping technique, which is widely used in the coating industry to reduce and control the thickness of a liquid film dragged by a moving substrate. For that purpose, a turbulent slot jet impinges on the liquid surface, involving a runback flow and consequently a lower coating thickness downstream wiping. The different process parameters (nozzle pressure, nozzle to substrate standoff distance, slot width, substrate speed) allow controlling the final film thickness. This metering technique is very common in coating processes, such as the application of gelatin layers on photographic films. The first part of this thesis deals with the prediction of the mean jet wiping flow, i.e. the film thickness distribution in the wiping region. A lubrication model is developed for that purpose, which is simplified to a zero-dimensional model giving directly the final thickness In the second part, the prediction of splashing occurrence in jet wiping is addressed. The splashing phenomenon in jet wiping is featured by the ejection of droplets from the runback flow, and it constitutes a physical limit to the process. An experimental investigation is conducted on a water model facility, and based on a phenomenological description, a dimensionless correlation in terms of film Reynolds number and jet Weber number is derived for splashing occurrence. The latter is perfectly well validated with observations on industrial lines. The last part of this thesis is dedicated to the study of the unsteady phenomena occurring on the free surface of the liquid film downstream wiping. This phenomenon has never been understood nor characterized up to now. In the present research, undulation is investigated both theoretically and experimentally. Two model test facilities with dedicated measurement techniques have been designed and constructed. They allow performing parametric studies of the undulation characteristics (amplitude, wavelength, wave velocity), and analyzing the jet/film interaction.

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Rainfall induced granular flow slides pose a significant risk in many areas of the world. These failures, characterized by the sudden release of material in a fluid-like manner, are the result of static liquefaction occurring in these slopes. The static liquefaction phenomenon has been linked to instability. Instability behaviour is primarily studied under undrained triaxial conditions, and although many instability theories have therefore been defined in this stress space, these have been shown to also extend into plane strain conditions. In order to further investigate this behaviour under these stress conditions, Wolinsky et al. (2013) developed a tilt-table soil box for use in a geotechnical centrifuge to analyze instability in infinite slope soil models. This testing apparatus has been used to simulate instability in plane strain under both dry and saturated soil conditions. Stress-controlled experiments were performed on dry infinite slope soil models to investigate the effects of both void ratio and effective stress on instability behaviour. By performing these tests dry, this test apparatus provides the ability to decouple the triggers of instability from the corresponding response in pore pressure and the consequences. The results of this testing confirmed that the instability line angle is a function of both void ratio and effective stress. As the void ratio decreases and effective stress in the soil model increases, the resulting instability line angle will increase. This testing also demonstrated typical stress-dilatancy behaviour in these infinite slope models, characterized by contractive response in loose soils and dilative response in dense soil subject to increasing shear stress. Secondly, this testing apparatus was used to investigate the effects of seepage force on instability behaviour in granular slopes through the introduction of groundwater seepage in the form of a rising groundwater level. Although the results illustrated shear and volumetric response to these increased pore water pressures, these were not significant enough to initiate instability and the resulting pore water response leading to failure. It has been determined that this apparatus must be further adapted to dissipate the matric suctions developed above the water table during groundwater rise. / Thesis (Master, Civil Engineering) -- Queen's University, 2013-12-03 21:06:56.806

Genomic instability and aneuploidy, which are ubiquitous hallmarks of cancer cells, encompass both structural and numerical chromosome aberrations. Strikingly, cancer cells often display recurrent patterns of aneuploidy which are thought to be contingent on selection pressures within the tumour microenvironment maintaining advantageous karyotypes. However, it is currently unknown if individual chromosomes are intrinsically vulnerable to missegregation, and therefore whether chromosome bias may also contribute to pathological aneuploidy patterns. Moreover, the earliest responses to chromosome missegregation in non-transformed cells, and how these are overcome in cancer, has remained elusive due to the difficult nature of isolating nascent aneuploid cells. Results. Individual chromosomes displayed recurrent patterns of biased missegregation in response to a variety of cellular stresses across cell lines. Likewise, a small subset of chromosomes accounted for a large fraction of segregation errors following one specific mechanism driving aneuploidy. This was supported by the discovery that chromosomes 1 and 2 are strikingly susceptible to the premature loss of sister chromatid cohesion during prolonged prometaphase arrest. Additionally, I have elucidated the arrangement of individual metaphase human chromosomes, highlighting missegregation vulnerabilities occurring at the metaphase plate periphery following nocodazole wash-out. Finally, I have developed a novel system for isolating nascent aneuploid cells, suggesting the earliest transcriptome responses to chromosome missegregation in non-transformed human cells involve ATM and BCL2-mediated apoptosis.

Orientador: João Luiz Amaro / Resumo: A instabilidade vesical é uma patologia bastante comum na prática urológica, porém sua etiopatogenia é pouco conhecida. A utilização de seres humanos na investigação de suas causas é restrita, principalmente devido aos problemas éticos. Nosso objetivo foi estudar as alterações histopatológicas e imunohistoquímicas decorrentes da obstrução parcial da bexiga. Foram utilizados 30 coelhos machos, divididos em grupo G1 (controle clínico, n=15) e grupo G2 (obstruído, n=15). No grupo G2 foi realizada obstrução parcial da bexiga usando um bracelete ajustável de polietileno e foram considerados os animais que desenvolveram contrações involuntárias do detrusor (CID). Foram submetidos a dosagem de uréia e creatinina plasmática, cultura de urina e estudo cistométrico em 2 momentos, inicial (M1) e final (M2) após 4 semanas da obstrução. Após este período, os coelhos foram sacrificados e a bexiga retirada para realização de estudo histopatológico e imunohistoquímico. Observou-se um aumento significativo do peso corporal dos coelhos nos diferentes momentos. O peso da bexiga foi 2,5 vezes maior no grupo G2 comparado com o grupo G1 (controle clínico). Não houve diferença estatisticamente significativa na análise da uréia plasmática. A creatinina plasmática foi significativamente maior no grupo G2 (obstruído) em comparação com o grupo G1 no momento final. Detectou-se cultura positiva em 40% dos casos no momento M1 (inicial) e 50% no M2 (final). A análise do estudo urodinâmico demonstrou aumento significativo da capacidade vesical no momento M2 no grupo G2. Não houve diferença estatisticamente significativa na pressão máxima do detrusor e na complacência vesical nos diferentes momentos. Verificou-se persistência das contrações involuntárias do detrusor em todos os animais... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The bladder instability is a very common problem in urology, however its etiology is rather unknown. The use of human beings is limited in the study of detrusor instability, specially because of ethical problems. For this reason we have proposed an experimental study of the bladder instability in rabbits due to partial bladder outlet obstruction. Thirty male rabbits were divided in G1 (control group) and G2. The animals in G2 had their bladder obstructed by using an adjustable polyethylene ring. Both groups were submitted to cystometrical evaluations in two moments: initial (before surgery) and final (after 4 weeks of obstruction). After this period, the rabbits were sacrificed, their bladder was removed and the alterations evaluated in the histologic and immunohistochemical study. The results showed an increase in the body weight of the rabbits and the bladder was 2.5 times heavier than the control group. There was no significative statistical difference in the plasmatic urea analysis. The results showed significative statistical difference between the groups in the final moment (the final moment was superior than the initial moment in G1). There was positive culture in 40% of the cases in M1 and 50% in M2. The analysis of the urodynamics study presented an increase in the bladder capacity in M2, G2. There was no significative statistical difference in the detrusor maximum pressure and in the bladder compliance. We could detect the persistence of the detrusor spontaneous contractions in all the animals in G2 in M2. The histological study showed 13% of epithelium ulceration and 40% of submucosal fibrosis in the obstructed animals. All the rabbits in G2 presented adventitious fibrosis. The inflammatory reaction was significatively bigger in G2. There was no statistical difference in the analysis of the intermuscular fibrosis. The results showed 54% of... (Complete abstract click electronic address below) / Mestre

Foamed concrete has considerable potential as a material for use in the construction industry. However, although some researches have been conducted on the characteristics of foamed concrete, thus far, knowledge on the behaviour of foamed concrete has been limited. Hence, predictions of the stability of foamed concrete under different conditions and mix constituents have been uncertain. The aim of the presented study is to investigate causes of instability of foamed concrete by examining its rheological properties and microstructure. This study explores the complex causes of instability in foamed concrete by examining the rheological parameters, the yield stress and the plastic viscosity, since the rheological properties affect the hardened state. Using flowability as a guide, the relationships are examined between yield stress and viscosity, specifically with reference to their effect on density and w/c ratio. Other factors affecting the rheological properties related to the proportions and fineness of the mix constituents are also considered. Thereafter, the microstructure of foamed concrete is examined to establish links with the rheological values and the relationship with stability. The microstructure, best described by the bubble sizes, has been found to be a function of yield stress, plastic viscosity, material fineness and surfactant types. The bubble diameters have been shown to range between 0.1 to 0.5 mm. Bubbles less than 0.35 mm in diameter correspond to stable mix with a drop in level of less than 5% in height in densities of 1000 kg/m3 and higher. The big bubbles link to unstable mixes and have been found to be a source of instability. Other chemical additions were shown to result in disintegration of bubbles. As this study unfolds, a relationship is established between bubbles and the yield stress values. Bubble sizes reduced when the yield stress increased. For flowability out of Marsh cone test taken between 1 to 2 minutes, the corresponding yield stress was between 6.0 N/m2 to 8.5 N/m2. For this range, the empirical bubble sizes were found to be between 0.33 to 0.35 mm in diameter. In examining the possible causes of instability, it was found that stability improved markedly with increase in density and lesser effect by other factors such as w/c ratio, constituent materials and specimen height. However, the rate of hardening was a dominant factor in stability as evidenced by the use of Calcium Sulfoaluminate cement, CSA and CEM I 52.5R cement which increased the setting times. Stability was drastically achieved even at lower density 300 kg/m3. Blends of CSA with CEM I 52.5R and fine fly ash, FAf, demonstrated similar results. This research has implications for the development of foamed concrete as a material that could be more widely used in certain construction contexts where stability in lightweight density foamed concrete is crucial. It has contributed to better understanding of the rheological properties and the effect on the microstructure, even though the results are based on empirical values. Hence, it is anticipated that the prediction of stability can be made through a selection of materials and proportions to suit different contexts and their requirements.