Wide spaced reinforced masonry (WSRM) walls that contain vertical reinforced cores at horizontal spacing up to 2000mm are commonly used in high wind zones of Australia although their inplane shear resistance is not well understood. This thesis aims at providing better insight into the behaviour of WSRM walls subjected to inplane lateral loading through experimental and numerical investigations. The interactions between the unreinforced masonry (URM) panels and vertical reinforced cores are first determined using an elastic finite element analysis and the potential failure paths hypothesized. The hypotheses are then validated using a series of full-scale WSRM and Non-WSRM wall tests under monotonic and cyclic lateral loading by keeping the spacing between the vertical reinforced cores as the main design variable. Load-displacement response of these shear walls indicates that the current classification of the WSRM in AS3700 (2001) as those walls containing vertical reinforced grouted cores at 2000mm maximum spacing is appropriate. A finite element model (FEM) based on an explicit solution algorithm is developed for predicting the response of the masonry shear walls tested under static loading. The FEM has adopted macroscopic masonry failure criteria and flow rules, damaged plasticity model for grout and tension-only model for reinforcing bars reported in the literature, and predicted crack opening and post-peak load behaviour of the shear walls. By minimising the kinetic energy using appropriate time scaling, the FEM has provided reasonable and efficient prediction of load flow, crack patterns and load–displacement curves of the shear walls. The FEM is further validated using full-scale tests on WSRM walls of aspect ratios and pre-compression different to that tested before. The validated FEM is used to examine the appropriateness of the prescriptive design details for WSRM concrete masonry shear walls provided in AS3700 (2001) allowing for a large scatter in material properties. It is shown that the inplane shear capacity formula provided in AS3700 (2001) for squat WSRM shear walls is non-conservative.

The ability to separate a suspension into its respective solid and liquid constituents is an important requirement in the chemical, wastewater and mineral industries. Typically, separation occurs in open, large diameter tanks known variously as thickeners, settlers or clarifiers. The design and operation of these devices have been based, until recently, on kinematic models and macroscopic mass balances. The problem with these approaches is that consolidation in the bed is not described accurately and consequently, the area required for thickening is often grossly overestimated. Recently, Buscall and White [24] proposed a 1−D phenomenological theory of dewatering that encompasses both sedimentation and consolidation, providing a more solid grounding for understanding, simulating and optimising dewatering in a range of devices, including thickeners. This theory identifies two important rheological parameters; a concentration dependent yield stress, Py (φ) and hindered settling function, R(φ). / Despite representing a significant improvement over a kinematical approach, Buscall and White’s dewatering theory involves a number of simplifications so that in practise, simulations often underestimate dewatering in full sized thickeners [97, 153]. One aspect of thickening that is poorly understood is the effect of raking. At the base of the thickener, a rake transports the thickened sediment to the outlet. An additional effect from raking is to increase the average solid concentration in the underflow [33, 46]. Raking introduces normal and shear stresses, which cannot be described within a one-dimensional framework. Therefore, observed differences between predicted and measured thickener underflow concentrations are attributed to the action of the rake. / The aim of this thesis is to develop a better understanding of how shear stresses effect compressional dewatering in both pilot and full scale thickening operations. Before attempting to quantify the effect of shear on dewatering, it was considered necessary to first establish that the 1-D model was capable of predicting dewatering in the absence of shear. Up until now, no known studies have been undertaken to validate the model under controlled conditions. To approximate one-dimensional flow with no shear, a tall narrow column with no moving parts was used. Two solid fluxes and several bed heights were studied, and the outputs from the column were compared with the 1-D model predictions. The results show that under ideal conditions, the model predicted the underflow solid concentration to within 10 %. / The effect of shear on dewatering was investigated using a Couette shear device. Couette geometry was chosen to provide uniform shear. Since in Couette flow, no normal stresses act in the direction of rotation, the mechanism behind dewatering can investigated. These experiments showed that shear caused dewaterability to improve up to a critical shear rate, beyond which dewaterability was adversely affected. The relationship between this critical shear rate and flocculation conditions was investigated by using different flocculant dosages. The shear modified Py (φ,γ) and R(φ,γ) can be input to the 1−D model, thereby incorporating shear indirectly. As a result, the model predicted an order of magnitude increase in solids flux. / The above procedure was used to characterise the dewaterability of a real thickener feed as a function of shear rate. The optimum shear rate was determined by finding the minimum R(φ,γ). Then, Py(φ) and R(φ) were input into the thickener model. The predicted underflow concentration could then be compared against plant data. / Even when shear is taken into account, the model still under predicts the performance of the thickener. To understand this result, the pilot column work was revisited since the control over experimental conditions was far greater. To introduce shear, concentric cylinders were installed in the column and rotated at a fixed speed. Thus, the effect of shear and bed height on underflow density were determined at different rates of shear. This showed that the underflow concentration increased with bed height; a result not expected based on the model prediction. The effects of shear on underflow density were secondary to bed height. / The bed height dependence can only be explained if dewatering is not steady but changes over time. For a four metre bed height the residence time is eight times longer than a one metre bed. Improvements in dewatering could be related to time dependent restructuring of aggregates which would result in an associated change in R(φ). By fluidizing suspensions for times corresponding to the residence times in the tall column, R(φ) and Py(φ) could be determined, as functions of volume fraction and time. Aggregate properties including structure and density were measured before and after fluidization using focussed beam reflectance measurement (FBRM) and floc density analysis (FDA).

A dual-station high frequency Wellen Radar (WERA), transmitting at 16.045 MHz, has been deployed along the Eastern Florida Shelf (EFS). From September 2004 to June 2005, a moored acoustic Doppler current profiler (ADCP) acquired subsurface current measurements within the radar footprint along the shelf break at 86-m depth. The shallowest ADCP bin located at 14-m depth is used as a comparison for the WERA surface measurements. The RMS differences range from 0.1 to 0.3 m s super -1 between the surface and 14-m depth, with good agreement over most of the period. Regression analyses indicate slopes near unity in the north-south (v-) component and approximately 0.5 for the east-west (u-) component velocities. Following validation of the HF radar surface current measurements, an assessment of the variability and character of eddies in the region is conducted for 2006. Optimal interpolation is utilized to create a uniform 45 km by 45 km grid of surface current data consisting of 1980 points in the inshore portion of the WERA domain. The Okubo-Weiss parameter is used to identify eddies as closed regions with values greater than a threshold of 2*10 super -8 s super -1. This method reveals a total of twenty-two eddy-like features over the year 2006. Given the asymmetric shape of the eddy regions, equivalent radii are computed as an estimate of eddy size with an annual average of 2.6 km. Eddy intensity is measured by maximum relative vorticity in the eddy region with an annual average of approximately 5f, where f is the local Coriolis parameter. Translational velocities are computed from the displacement of peak Okubo-Weiss parameter. This method tends to overestimate eddy speed given the shape-changing nature of the eddy regions. Nonetheless, the average translational velocity is 0.9 m s super -1 with a standard deviation of 0.4 m s super -1. Eddy tracks indicate a unique pattern in which eddies propagate inshore during the period of July to September and offshore during October to December related to position of the FC axis. The periodicity and spatial distribution of eddy events suggest that submesoscale eddy features are "wave-like" and centered along the strong topographical gradients between 200 to 600 m. By applying this methodology to other years of HF radar data, this statement can be tested with statistical confidence. In general, this study has shown the effectiveness of the Okubo-Weiss parameter in identifying eddy regions from a background field with large, ambient vorticity.

Thesis (M.S.)--Washington State University, December 2006. / Includes bibliographical references (p. 88-93).

Thesis (Ph.D.)--University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (February) Vita. Includes bibliographical references.

In the pharmaceutical industry uniform flow of powders is one of the most important considerations in solid dosage manufacture. Improper feeding of powders from storage hoppers into dye-presses can lead to inconsistent product quality, causing economic and health impacts. Investigation into the properties affecting powder flow is crucial. There were four objectives of the current research: 1. To determine the effect of moisture on the flow (Jenike flow index, Hausner Ratio and Carr Index, static and dynamic angle of repose) of selected pharmaceutical powders. 2. To study the effect of particle shape and size on Jenike flow index for selected starch and pharmaceutical powders. 3. To determine the effect of mixture compositions on the Jenike flow index of ordered mixtures of selected pharmaceutical powders. 4. To develop a novel flowability tester based on electrical capacitance tomography (ECT) that measures the dynamic angle of repose of powders.<p>To address the first objective, to determine the effect of moisture content on the flow of four pharmaceutical powders; an active pharmaceutical ingredient (API), aspartame, hydroxypropyl methylcellulose (HPMC), and Respitose® ML001 were selected. The API and Respitose® powders were found to be nonhygroscopic and were tested at near zero moisture contents only (in this case 0.31% and 0.19% respectively). Aspartame was tested at moisture contents of 0%, 2%, 5% and 8% and HPMC at moisture contents of 0%, 2%, 5% and 10%. Powder flowability was measured using the Jenike shear index, the Hausner Ratio, the Carr Index and the static and dynamic angles of repose. The Jenike flow index of aspartame increased from 0.885 to 3.65 with an increase in moisture content, which was attributed to the formation of large, round agglomerates. The Jenike flow index of HPMC decreased from 3.28 to 2.65 with an increase in moisture content, which was attributed to the increasing strength of liquid bridges. The Jenike flow index was the only flowability indicator to capture this complex behaviour. <p>In order to address the second objective, five starches (cow cockle, barley, rye, rice and tapioca), as well as four pharmaceutical ingredients (an API, aspartame, HPMC, and Respitose® ML001), were characterised for size and shape, and then tested for flowability. Powder flowability was measured using the Jenike shear test, the most widely accepted flowability standard in the pharmaceutical industry. It was found that the Jenike flow index decreased linearly with decreasing aspect ratio and decreasing roundness for the powders investigated. It was also determined that particle shape had a greater impact on flowability than size for powders under 30 microns in diameter. <p>To address the third objective, ordered mixtures of pharmaceutical powders were examined to determine their flowability. Six combinations of Respitose® ML001, hydroxypropyl methylcellulose (HPMC), and an active pharmaceutical ingredient (API) in varying concentrations were selected for investigation. Powder flowability was measured using the Jenike shear test, the most widely accepted flowability standard in the industry. The Jenike flow indices of the ordered mixtures were indistinguishable from the Jenike flow index of pure Respitose® at the alpha = 0.1 level.<p>The fourth objective, to develop a novel flowability tester using electrical capacitance tomography to measure the dynamic angle of repose, was investigated at the same time as the effect of moisture content. It was determined that the results of the novel dynamic angle of repose tester did not correlate well with the Jenike shear test. More development is needed before the novel flowability tester is ready for industrial use. The Jenike shear cell remains the only acceptable flow test for complex flow behaviour.

In the pharmaceutical industry uniform flow of powders is one of the most important considerations in solid dosage manufacture. Improper feeding of powders from storage hoppers into dye-presses can lead to inconsistent product quality, causing economic and health impacts. Investigation into the properties affecting powder flow is crucial. There were four objectives of the current research: 1. To determine the effect of moisture on the flow (Jenike flow index, Hausner Ratio and Carr Index, static and dynamic angle of repose) of selected pharmaceutical powders. 2. To study the effect of particle shape and size on Jenike flow index for selected starch and pharmaceutical powders. 3. To determine the effect of mixture compositions on the Jenike flow index of ordered mixtures of selected pharmaceutical powders. 4. To develop a novel flowability tester based on electrical capacitance tomography (ECT) that measures the dynamic angle of repose of powders.<p>To address the first objective, to determine the effect of moisture content on the flow of four pharmaceutical powders; an active pharmaceutical ingredient (API), aspartame, hydroxypropyl methylcellulose (HPMC), and Respitose® ML001 were selected. The API and Respitose® powders were found to be nonhygroscopic and were tested at near zero moisture contents only (in this case 0.31% and 0.19% respectively). Aspartame was tested at moisture contents of 0%, 2%, 5% and 8% and HPMC at moisture contents of 0%, 2%, 5% and 10%. Powder flowability was measured using the Jenike shear index, the Hausner Ratio, the Carr Index and the static and dynamic angles of repose. The Jenike flow index of aspartame increased from 0.885 to 3.65 with an increase in moisture content, which was attributed to the formation of large, round agglomerates. The Jenike flow index of HPMC decreased from 3.28 to 2.65 with an increase in moisture content, which was attributed to the increasing strength of liquid bridges. The Jenike flow index was the only flowability indicator to capture this complex behaviour. <p>In order to address the second objective, five starches (cow cockle, barley, rye, rice and tapioca), as well as four pharmaceutical ingredients (an API, aspartame, HPMC, and Respitose® ML001), were characterised for size and shape, and then tested for flowability. Powder flowability was measured using the Jenike shear test, the most widely accepted flowability standard in the pharmaceutical industry. It was found that the Jenike flow index decreased linearly with decreasing aspect ratio and decreasing roundness for the powders investigated. It was also determined that particle shape had a greater impact on flowability than size for powders under 30 microns in diameter. <p>To address the third objective, ordered mixtures of pharmaceutical powders were examined to determine their flowability. Six combinations of Respitose® ML001, hydroxypropyl methylcellulose (HPMC), and an active pharmaceutical ingredient (API) in varying concentrations were selected for investigation. Powder flowability was measured using the Jenike shear test, the most widely accepted flowability standard in the industry. The Jenike flow indices of the ordered mixtures were indistinguishable from the Jenike flow index of pure Respitose® at the alpha = 0.1 level.<p>The fourth objective, to develop a novel flowability tester using electrical capacitance tomography to measure the dynamic angle of repose, was investigated at the same time as the effect of moisture content. It was determined that the results of the novel dynamic angle of repose tester did not correlate well with the Jenike shear test. More development is needed before the novel flowability tester is ready for industrial use. The Jenike shear cell remains the only acceptable flow test for complex flow behaviour.

Laminated glass is comprised of multiple glass plates coupled together in a sandwich construction through the use of a polymorphous interlayer that acts as a bonding agent between the glass plates. Laminated glass offers several advantages over monolithic glass including the ability to resist post fracture collapse, improved sound insulation, lower ultraviolent light trans-mission, and improved thermal insulation. Because the stiffness of the interlayer is often many orders of magnitude less than that of the glass, plane sections prior to loading do not remain plane throughout the laminate?s thickness after load is applied. The behavior of laminated glass is controlled by the stiffness of the interlayer. This behavior rules out the use of classical theoretical formulations for thin plates. In such cases, it is necessary to use specially formulated equations or finite element analyses to evaluate the performance of laminated glass. Previous attempts have been made to develop procedures to quantify the interlayer stiffness for use in laminated glass design. However, there is no widely accepted technique that can be referenced for use. It is known that the interlayer stiffness is a function of both temperature and load duration. The primary objective of this thesis is to formalize a standard procedure to estimate the in situ interlayer shear modulus through the use of nondestructive testing. Physical experiments were carried out on simply supported laminated glass beams subject to three point loading in a temperature controlled environmental testing chamber. Strains and temperatures were recorded as a function of time. These data were used in combination with results from finite element analyses to quantify the variation of the interlayer stiffness as a function of temperature and load duration for a given laminated glass beam. This procedure was applied to three common types of interlayer materials: freshly man-factured polyvinyl butyral (PVB), over a decade old PVB, and freshly manufactured SentryGlas Plus (SGP). Results from these efforts provide specific design guidance for laminated glass that incorporates these interlayer materials. Further, the procedure was applied to various data presented in open literature by previous researchers. In addition, a standardized procedure to estimate interlayer stiffness is provided for the development of additional interlayer properties as required.

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The shear strength behavior of unsaturated soils is a complex phenomenon. The major factors that lead to the complex behavior are grain size, natural alteration in status of moisture and associated capillary potential. The need for research is felt to understand the various aspects associated with development of shear strength of unsaturated soils. The research is conducted to obtain the most economical and reliable design solutions. The magnitude of positive pore water pressure developed in saturated soil reduces the shear strength to a great extent. The tensile pore water pressure in the capillary meniscus developed around the soil grain contacts, on the contrary, enhances the factor of safety in the case of unsaturated soil mass. In this research, the shear strength of unsaturated soil is studied for a range of saturation based on the parametric study. The principle of effective stress has proven to be the basis for understanding the shear strength of saturated soil mass and it has provided an explanation for the geotechnical engineering problems. The thesis presents a study on the shear strength of the soil specimen using the direct shear apparatus. The previous research was mainly directed towards evaluation of shear strength under controlled soil suction, by modifying the apparatus. A simple technique is put forward in this research by making use of the conventional direct shear apparatus for testing the unsaturated soil. The suction stress was induced in the soil specimen and the shear strength was evaluated. The soil water characteristic curve has been used in the research to determine the tensile pore water pressure. Hypothesis based on parametric study has been put forward to present a technique to determine the unsaturated soil shear strength parameter in the thesis.