This dissertation investigates deformable computer input device technologies to facilitate capturing complex physical-world gestures. By capturing the physical gestures and using appropriate haptics, it is possible to create virtual models using pinching and squeezing gestures similar to those used when sculpting clay. To date, most desktop modelling applications employ pointing devices that capture a single cursor location to manipulate a model with tedious sequential steps. One reason for this is developers have focused efforts on adopting applications to work with generic two-dimensional pointing devices, such as a mouse or digitising tablet. This is due to the difficulty of developing three-dimensional input technologies. In particular, deformable sensors capable of capturing natural sculpting techniques are undeveloped. / PhD Doctorate

The Unsettled Object is an installational art project that considers the instability of objects in regards to their assembly, classification, and presentation, underpinned by the context of the museum and supported by Michel Foucault’s notion of the classificatory grids he discusses in The Order of Things: an archaeology of the Human Sciences. (Foucault,1970) The artefacts are being fabricated as a response to the corporeal body-on-display; its surfaces, spaces and volumes. An underlying notion of temporality and mutability is indicated in the processes of making, the objects, material responsiveness and the devices employed in the presentation of the work.

This thesis focuses on closed-cell aluminium foams (ALPORAS and ALULIGHT) and on sandwich panels comprising these foams laminated with 2/2 twill carbon fibre (MTM56/0300) skins. The thesis experimentally and analytically investigates the response of foam-only panels (ALPORAS) to indentation with various indenter sizes and shapes; and also studies the behaviour of sandwich panels to contact damage caused quasi-statically or by impact. Quasi??static uniaxial compression testing is used to determine the mechanical properties of the foams (ALPORAS and ALULIGHT). It is revealed that the plastic collapse strength (σ* pl) obtained from the stress??strain curves is lower than the values predicted by the Gibson-Ashby theoretical model. This phenomenon is explained by the fact that the aluminium foams tested are imperfect, non-homogeneous and non-isotropic, and show a distinct cell elongation. Whereas, the Gibson-Ashby theoretical model was based on the finite element method applied to the response of a unit tetrakaidecahedral closed cell having flat faces. The experimental work shows that the deformation of the foam-only panels to indentation is caused by progressive crushing of the cell bands and by shearing and tearing of the cell walls. This thesis presents new analytical models for the response of the foam-only panels and estimates the applied deformation load in all types of indentation. By fitting the experimental load-displacement curves, the shear strength (τ* pl) and the tear energy (γ) are deduced. Compared to the literature, more consistent results are obtained for the shear strength (τ * pl) and the tear energy (γ) from all types of indentation. It is also suggested to determine (τ * pl) and (γ) through indentations with long punches (FEP and LCP), instead of hemi-spherical or cylindrical indenters, because indentation on enclosed areas shows some indenter size dependence. It is concluded that thinner panels are not suitable for the determination of the tear energy (γ) since the densification of the foam is achieved before the tear resistance is fully engaged. Another objective of this thesis is to study the response of sandwich panels comprising a closed??cell aluminium foam core and laminated with carbon fibre skin to quasi-static and impact local damage. Special attention is paid to the residual (remnant) strength in bending of the already indented sandwich panels (quasi-statically or by impact) up to the failure point. The remnant strength in bending is determined by carrying out four point bending strength tests. The local damage is located on either the compressive or on the tensile side of the sandwich panels. Thus, the capacity of the panels to resist transverse loads after they have been locally damaged at contact is investigated. The contact damage on the sandwich panels is experimentally simulated using spherical indenters. The quasi-static indentation is carried out at a low constant velocity (0.5mm/min) ?? the induced contact damage is found to be independent on the sample thickness but dependent on the indenter diameter. On the contrary, the impact test indicates velocity-dependence of the failure mode of the sandwich panel (i.e. skin breakage or punch through) which is found from the load-displacement curves. The results reveal that there is a correlation between the area of the contact damage and the remnant strength, and that the use of metal foam cores leads to high contact damage resilience of composite structures.

This thesis focuses on closed-cell aluminium foams (ALPORAS and ALULIGHT) and on sandwich panels comprising these foams laminated with 2/2 twill carbon fibre (MTM56/0300) skins. The thesis experimentally and analytically investigates the response of foam-only panels (ALPORAS) to indentation with various indenter sizes and shapes; and also studies the behaviour of sandwich panels to contact damage caused quasi-statically or by impact. Quasi??static uniaxial compression testing is used to determine the mechanical properties of the foams (ALPORAS and ALULIGHT). It is revealed that the plastic collapse strength (σ* pl) obtained from the stress??strain curves is lower than the values predicted by the Gibson-Ashby theoretical model. This phenomenon is explained by the fact that the aluminium foams tested are imperfect, non-homogeneous and non-isotropic, and show a distinct cell elongation. Whereas, the Gibson-Ashby theoretical model was based on the finite element method applied to the response of a unit tetrakaidecahedral closed cell having flat faces. The experimental work shows that the deformation of the foam-only panels to indentation is caused by progressive crushing of the cell bands and by shearing and tearing of the cell walls. This thesis presents new analytical models for the response of the foam-only panels and estimates the applied deformation load in all types of indentation. By fitting the experimental load-displacement curves, the shear strength (τ* pl) and the tear energy (γ) are deduced. Compared to the literature, more consistent results are obtained for the shear strength (τ * pl) and the tear energy (γ) from all types of indentation. It is also suggested to determine (τ * pl) and (γ) through indentations with long punches (FEP and LCP), instead of hemi-spherical or cylindrical indenters, because indentation on enclosed areas shows some indenter size dependence. It is concluded that thinner panels are not suitable for the determination of the tear energy (γ) since the densification of the foam is achieved before the tear resistance is fully engaged. Another objective of this thesis is to study the response of sandwich panels comprising a closed??cell aluminium foam core and laminated with carbon fibre skin to quasi-static and impact local damage. Special attention is paid to the residual (remnant) strength in bending of the already indented sandwich panels (quasi-statically or by impact) up to the failure point. The remnant strength in bending is determined by carrying out four point bending strength tests. The local damage is located on either the compressive or on the tensile side of the sandwich panels. Thus, the capacity of the panels to resist transverse loads after they have been locally damaged at contact is investigated. The contact damage on the sandwich panels is experimentally simulated using spherical indenters. The quasi-static indentation is carried out at a low constant velocity (0.5mm/min) ?? the induced contact damage is found to be independent on the sample thickness but dependent on the indenter diameter. On the contrary, the impact test indicates velocity-dependence of the failure mode of the sandwich panel (i.e. skin breakage or punch through) which is found from the load-displacement curves. The results reveal that there is a correlation between the area of the contact damage and the remnant strength, and that the use of metal foam cores leads to high contact damage resilience of composite structures.

People with diabetes suffer from an increased incidence of atherosclerosis, possibly due to the hyperglycaemia associated with this disease. Glucose may covalently modify proteins via glycation and glycoxidation reactions. Reactive aldehydes (e.g. methylglyoxal and glycolaldehyde) generated from these glycation and glycoxidation reactions, lipid peroxidation and other metabolic pathways may also modify proteins in glycation and glycoxidation reactions. These reactions can result in the formation of advanced glycation end-products, which are increased in diabetes and associated complications such as atherosclerosis. Low-density lipoproteins (LDLs) are the main source of lipid in atherosclerotic plaques, and the lipid-laden foam cells contained within. Modification of the single protein in LDL, apolipoprotein B-100 (apo B) by glucose and aldehydes may result in recognition of these altered LDL particles by macrophage scavenger receptors and cellular accumulation of cholesteryl esters; such accumulation is characteristic of atherosclerotic foam cells. The extent and nature of the modifications of LDLs that give rise to this behaviour have been poorly characterised, especially in regards to modification/oxidation of protein versus lipid components induced by glucose and low-molecular-mass aldehydes. Therefore the aims of this project were to: 1) characterise LDL modification by glucose, methylglyoxal and glycolaldehyde; 2) examine the effect of these modified LDLs on arterial cells by monitoring cellular viability, proliferation and cholesterol and cholesteryl ester levels; and 3) examine macrophage handling of apo B from these modified LDLs. Glycolaldehyde induced more rapid and more extensive changes to LDL than methylglyoxal, which was significantly more modified than LDL exposed to glucose, in the presence or absence of Cu2+. LDL was modified by glycolaldehyde and methylglyoxal in a time- and concentration-dependent manner. These aldehyde-modified LDLs were significantly more negatively charged relative (determined by changes in relative electrophoretic mobility), more aggregated (by SDS-PAGE) and lost more Arg, Lys and Trp residues (assessed by fluorescence-based assays) than glucose-modified and control LDLs. Glucose-modified LDL had more modest increases in net negative charge, aggregation and only significantly lost Arg residues. Under the conditions examined none of the modified LDLs contained significant levels of the protein oxidation products DOPA and o-tyrosine, the lipid oxidation products 7-ketocholesterol and cholesteryl ester hydro(pero)oxides, nor marked depletion of the major antioxidant α-tocopherol or significant radical formation (EPR spectroscopy). Therefore these LDLs were glycated, but not (glyc)oxidised, and so allowed the cellular uptake of glycated LDL, rather than glycoxidised LDL, to be examined. These glycated LDLs had no effect on the cellular viability (assessed by LDH release), cell protein (BCA assay), and cholesterol and cholesteryl ester levels (quantified by reverse-phase HPLC) of endothelial and smooth muscle cells. The glycated LDLs also had no effects on human and mouse macrophage viability, protein and free cholesterol levels. However, exposure of macrophages to some of the glycated LDLs resulted in significant accumulation of cholesteryl esters and apo B. The greatest cellular accumulation of cholesteryl esters was in cells exposed to glycolaldehyde-modified LDL, which occurred in a time- and concentration-dependent manner. Less cholesteryl ester accumulation was observed in cells exposed to methylglyoxal-modified LDL, but some conditions resulted in significantly more cellular cholesteryl esters as compared to control LDLs, unlike glucose-modified LDL. Macrophages endocytosed significantly more apo B from glycolaldehyde-modified LDL labelled with 125I on the apo B, than methylglyoxal-modified 125I-LDL. Apo B from methylglyoxal-modified 125I-LDL was also endocytosed and degraded in greater amounts than control 125I-LDLs, unlike glucose-modified 125I-LDLs. The glycation of LDL by some low-molecular-mass aldehydes have been shown to result in model foam cell formation as characterised by cholesteryl ester and apo B accumulation. This accumulation correlated with increases in net negative charge, aggregation and loss of Lys and Trp residues of the apo B in glycated LDL particles. However, the differences in cellular uptake of glycolaldehyde- versus methylglyoxal-modified LDL were not completely resolved and it is postulated that this may arise from the extent or type of products formed on key amino acid residues, resulting in differential uptake by macrophage scavenger receptors, rather than loss of particular amino acids per se. Therefore these studies provide a potential mechanism to explain the increased atherosclerosis in people with diabetes, and a suitable model to examine the potential inhibition of the effects of glycated LDLs. This could provide potential therapeutic interventions to reduce diabetes-induced atherosclerosis.

Thesis (Ph.D.)--University of Delaware, 2007. / Principal faculty advisor: Richard P. Wool, Dept. of Chemical Engineering. Includes bibliographical references.

Thesis (M.S.)--West Virginia University, 2008. / Title from document title page. Document formatted into pages; contains xiii, 101 p. : ill. (some col.). Includes two zip files of TIF images. Includes abstract. Includes bibliographical references (p. 93-94).

Thesis (Master)--İzmir Institute of Technology, İzmir, 2005. / Keywords:crushing, aluminum foam, foam filling, energy absorber, composite tubes. Includes bibliographical references (leaves. 93-96).

Thesis (Ph. D.)--University of Texas at Austin, 2003. / Vita. Includes bibliographical references. Available also from UMI Company.

Thesis (M.S.)--Brigham Young University. Dept. of Mechanical Engineering, 2007. / Includes bibliographical references (p. 53-55).