The main objective of this research was to investigate possible uses of Western-Canadian grown chickpea (<i>Cicer arietinum</i> L.) in the form of flour, starch and protein isolates in low-fat pork bologna. <p>In the first study, flour, starch and protein isolates from six chickpea cultivars (three Kabuli and three Desi) from two harvests (2005 and 2006) were evaluated for their physico-chemical, functional and thermal properties. Chickpea flour was made by grinding seed to pass through a 0.1mm screen, whereas protein isolates and starch were prepared by a wet milling process. Protein isolates were prepared from chickpea flour (23.2% protein on average) by alkaline extraction (pH 8.0) and isoelectric precipitation (pH 4.3). Protein isolates contained 72.8-85.3% protein; the starch fraction contained 93.0-98.0% starch. On SDS-PAGE, the chickpea flours and protein isolates contained similar polypeptide bands in the range of 30 to 55 kDa, with three major bands at approximately 50-55, 40 and 30 kDa. Least gelation concentration (LGC) for chickpea flours ranged from 6-14%; LGC for chickpea protein isolates ranged from 10-14%. Differential scanning calorimetry (DSC) of chickpea flour slurries revealed two endothermic peaks. One corresponded to starch gelatinization at approximately 64°C, which was slightly higher than for the starch fraction (~60°C). The second broad peak at approximately 96°C corresponded to the denaturation of the globulin protein fraction, which was also slightly higher than for the protein isolates (~91°C). Chickpea flour exhibited nitrogen solubility index values higher than those of chickpea protein isolates and soy and pea protein isolates. Chickpea protein isolates exhibited water holding capacities, oil absorption capacities, emulsion activity indeces and emulsion stability indeces higher than those of the chickpea flours. CDC Xena (Kabuli) and Myles (Desi), in general, most exhibited properties appropriate for meat applications. In the second study, the efficacy of flour, starch and protein from CDC Xena (Kabuli hereafter) and Myles (Desi hereafter) were investigated in low-fat pork bologna (LFPB). Low-fat pork bologna (<5% fat) was prepared by incorporating 2.5 or 5.0% flour, 1.5 or 3.0% protein isolate (protein basis), or 1.0 or 2.0% starch in the formulation. Controls were prepared without any binder, and formulations containing wheat or pea flour, soy or pea protein isolate, potato or pea starch, or extra meat were prepared for comparison. Inclusion of chickpea flour, protein or starch had a positive effect (P<0.05) on the cook yield, expressible moisture and purge of LFPB, and had little effect on colour. Increasing chickpea flour substitution from 2.5 to 5.0% altered the sensory and instrumental textural quality of LFPB significantly (P<0.05). Desi flour at 5.0% showed the highest TPA (texture profile analysis) hardness and chewiness, Allo-Kramer shear values and torsion shear stress. Similarly, LFPB containing chickpea protein isolate (CPI), soy protein isolate (SPI) or pea protein isolate (PPI) (3.0% protein basis) was firmer than either LFPB containing 1.5% protein from CPI, SPI or PPI or the control-I (with the same level of meat protein). Likewise, LFPB formulated with 2.0% Kabuli or Desi starch had higher TPA values than those prepared with pea or potato starch. For most flavour sensory properties, Kabuli and Desi chickpea flour and starch, irrespective of level of incorporation, performed similarly to the control. However, panellists noted more off-flavours with the addition of wheat flour or pea flour at 5.0%. Chickpea protein isolate, SPI or PPI at the 1.5% protein addition level did not alter the flavour properties of LFPB.<p>It was concluded that chickpea flour, starch and protein had potential for utilization as extenders in low-fat meat emulsion systems such as frankfurters and bologna.

The goal of this thesis is to develop an efficient finite element model of a particular micro-positioning(MP) system, known as the 3RRR Mechanism. MP systems are capable of delivering accurate and controllable motion in the micro-metre to sub-micrometre range. Conventional mechanisms, which are often composed of rigid links with pinned connections are prone to friction, backlash and stiction, which are magnified at small displacements. As such MP systems utilize a new structure known as the compliant mechanism. The structure of most compliant mechanisms is based on conventional mechanisms; however they are monolithic devices which utilize flexible elements, instead of pins, to transform the input to a useful output position. One common flexible element found in compliant mechanisms is the right circular flexure hinge. The seminal work on flexure hinges was done by Paros and Weisbord(1965), the basis of which was to calculate compliance (the reciprocal of stiffness) in order to characterize the behaviour of the hinge when loaded. However they essentially modelled the flexure hinge as a 1-D beam, when it is in fact 3-D in nature. Researchers completing finite element models of MP systems and flexure hinges have extended the model to 2-D elements, still resulting in poor results when compared to experimental data. The task of completing a full 3-D finite element model of a MP system, let alone a right circular flexure hinge, is a major computational effort. For instance, a full 3-D model of the 3RRR mechanism would require over 1,000,000 degrees of freedom(DOF) dedicated to the flexure hinges alone. A 2-D model requires approximately 45,000 DOF in total; however, this number is still regarded as large. Given these facts, a new technique called the Equivalent Beam Methodology(EBM) has been developed to model the 3-D stiffness of any right circular flexure hinge with a low number of DOF. This method essentially maps the 3-D stiffness of the hinge to a number of 1-D beam elements. For comparison, the finite element model of the 3RRR mechanism which incorporates the beams of the EBM has under 300 DOF in total, and is more accurate than the 2-D model. This method is extremely accurate, easy to use, and has a very low number of DOF, which makes it suitable to many advanced finite element modelling analyses such as topographic optimization, dynamic and modal analysis.

The goal of this thesis is to develop an efficient finite element model of a particular micro-positioning(MP) system, known as the 3RRR Mechanism. MP systems are capable of delivering accurate and controllable motion in the micro-metre to sub-micrometre range. Conventional mechanisms, which are often composed of rigid links with pinned connections are prone to friction, backlash and stiction, which are magnified at small displacements. As such MP systems utilize a new structure known as the compliant mechanism. The structure of most compliant mechanisms is based on conventional mechanisms; however they are monolithic devices which utilize flexible elements, instead of pins, to transform the input to a useful output position. One common flexible element found in compliant mechanisms is the right circular flexure hinge. The seminal work on flexure hinges was done by Paros and Weisbord(1965), the basis of which was to calculate compliance (the reciprocal of stiffness) in order to characterize the behaviour of the hinge when loaded. However they essentially modelled the flexure hinge as a 1-D beam, when it is in fact 3-D in nature. Researchers completing finite element models of MP systems and flexure hinges have extended the model to 2-D elements, still resulting in poor results when compared to experimental data. The task of completing a full 3-D finite element model of a MP system, let alone a right circular flexure hinge, is a major computational effort. For instance, a full 3-D model of the 3RRR mechanism would require over 1,000,000 degrees of freedom(DOF) dedicated to the flexure hinges alone. A 2-D model requires approximately 45,000 DOF in total; however, this number is still regarded as large. Given these facts, a new technique called the Equivalent Beam Methodology(EBM) has been developed to model the 3-D stiffness of any right circular flexure hinge with a low number of DOF. This method essentially maps the 3-D stiffness of the hinge to a number of 1-D beam elements. For comparison, the finite element model of the 3RRR mechanism which incorporates the beams of the EBM has under 300 DOF in total, and is more accurate than the 2-D model. This method is extremely accurate, easy to use, and has a very low number of DOF, which makes it suitable to many advanced finite element modelling analyses such as topographic optimization, dynamic and modal analysis.

Elastin is an essential extracellular protein that is a key component of elastic fibres, providing elasticity to cardiac, dermal, and arterial tissues. During the development of the human cardiovascular system, elastin self-assembles before being integrated into fibres, undergoing no significant turnover during the human lifetime. Abnormalities in elastin can adversely affect its self-assembly, and may lead to malformed elastic fibres. Due to the longevity required of these fibres, even minor abnormalities may have a large cumulative effect over the course of a lifetime, leading to late-onset vascular diseases. This thesis project has identified important, over-represented repetitive elements in elastin which are believed to be important for the self-assembly and elastomeric properties of elastin. Initial studies of single nucleotide polymorphisms (SNPs) from the HapMap project and dbSNP resulted in a set of genetic variation sites in the elastin gene. Based on these studies, glycine to serine and lysine to arginine substitutions were introduced in elastin-like polypeptides. The self-assembly properties of the resulting elastin-like polypeptides were observed under microscope and measured using absorbance at 440nm. Assembled polypeptides were also cross-linked to form thin membranes whose mechanical and physical properties were measured and compared. These mutations resulted in markedly different behavior than wild-type elastin-like proteins, suggesting that mutations in the repetitive elements of the elastin sequence can lead to adverse changes in the physical and functional properties of the resulting protein. Using next-generation sequencing, patients with thoracic aortic aneurysms are being genotyped to discover polymorphisms which may adversely affect the self-assembly properties of elastin, providing a link between genetic variation in elastin and cardiovascular disease.

Elastin is an essential extracellular protein that is a key component of elastic fibres, providing elasticity to cardiac, dermal, and arterial tissues. During the development of the human cardiovascular system, elastin self-assembles before being integrated into fibres, undergoing no significant turnover during the human lifetime. Abnormalities in elastin can adversely affect its self-assembly, and may lead to malformed elastic fibres. Due to the longevity required of these fibres, even minor abnormalities may have a large cumulative effect over the course of a lifetime, leading to late-onset vascular diseases. This thesis project has identified important, over-represented repetitive elements in elastin which are believed to be important for the self-assembly and elastomeric properties of elastin. Initial studies of single nucleotide polymorphisms (SNPs) from the HapMap project and dbSNP resulted in a set of genetic variation sites in the elastin gene. Based on these studies, glycine to serine and lysine to arginine substitutions were introduced in elastin-like polypeptides. The self-assembly properties of the resulting elastin-like polypeptides were observed under microscope and measured using absorbance at 440nm. Assembled polypeptides were also cross-linked to form thin membranes whose mechanical and physical properties were measured and compared. These mutations resulted in markedly different behavior than wild-type elastin-like proteins, suggesting that mutations in the repetitive elements of the elastin sequence can lead to adverse changes in the physical and functional properties of the resulting protein. Using next-generation sequencing, patients with thoracic aortic aneurysms are being genotyped to discover polymorphisms which may adversely affect the self-assembly properties of elastin, providing a link between genetic variation in elastin and cardiovascular disease.

Purpose: Biomechanical differences between people with low back pain (LBP) and healthy controls have been shown previously. LBP has been associated with standing postures in occupational settings. A transient pain-generating model allows for comparisons between pain developers (PD) and non-pain developers (NPD). The first objective was to utilize a multifactorial approach to characterize differences between PD and NPD individuals. The second objective was to investigate the impact of exercise on LBP during standing. Methods: Forty-three participants without any history of LBP volunteered for this study. Participants performed pre- and post-standing functional movements and 2-hours of standing. Continuous electromyography (EMG) data were collected from 16 trunk and hip muscles, kinematic and kinetic data were used to construct an 8-segment rigid link model. Vertebral joint rotation stiffness (VJRS) measures were calculated. Participants completed visual analog scales (VAS) rating LBP every 15 minutes during the 2-hr standing. Participants were classified as PD or NPD based on greater than 10 mm increase in VAS. Participants were assigned to exercise (EX) or control (CON) groups. All participants returned for a second data collection following 4-weeks. Results: Forty percent of participants developed LBP during standing. The PD group had elevated muscle co-activation prior to reports of pain (p < 0.05). Following standing, there was a decrease in VJRS about the lateral bend axis during unilateral stance. PDEX had decreased VAS scores during the second data collection (p = 0.007) compared with PDCON. Male PDEX had decreased gluteus medius co-activation during standing (p < 0.05). Between-day repeatability for the CON groups was excellent with intraclass correlation coefficients > 0.80 for the majority of the outcome measures. Conclusions: There were clear differences between PD/NPD groups in muscle activation patterns, prior to subjective reports of LBP, supporting the hypothesis that some of the differences observed between these groups may be predisposing rather than adaptive. An exercise intervention resulted in positive changes in the PD group, both in subjective pain scores as well as muscle activation profiles. Elevated muscle co-activation in the first 15-30 minutes of standing may indicate that an individual is at increased risk for LBP during standing.

Transport measurements and fabrication of superconductor-exchange spring magnet-superconductor systems

In order to explore how electrons and holes in 2D semiconductors behave at 3He temperatures under millimeter wave irradiation, we developed a new probe and measurement technique. Our samples are specially grown high-mobility GaAs/AlGaAs 2D electron or hole systems that have been modulation doped with Si or C respectively and etched into Hall bars. We also use microwave irradiation waveguide techniques to probe edge magnetoplasmons in 2D electron systems and find that the periodic resistance oscillations in the magnetic field are independent of the length between the leads measured. This demonstrates that the propagation of edge states is a non-local effect, contrary to previously established research. We confirm microwave induced resistance oscillations using a newly developed probe that delivers microwaves from a frequency generator down to the sample via a coax line and coplanar waveguides. Due to the low frequency range (2 -- 40 GHz) and high irradiation powers available, we are able to observe microwave induced resistance oscillations and newly revealed fractional microwave induced resistance oscillations. The probe that we develop for this new measurement makes previously unattainable non-Faraday as well as Faraday irradiation geometries accessible. In addition to measuring quantum transport, it also allows us to measure the transmission of microwaves across the sample. We establish a differential measurement technique that instantaneously removes the background signal leaving only the transmission from the 2D system, also reducing the preparation time required. This is accomplished with a gated high-mobility sample prepared to allow for microwaves to be irradiated from the back. The advantage of this new technique is that it accommodates any gated/polished sample which can be mounted on the specially designed sample holder. From this arrangement we are able to measure the cyclotron resonance transmission minima of both the 2D electron and hole systems. We can then use the known values for the effective mass and cyclotron time constant as a confirmation that our new probe can successfully make the expected measurements.

No description available.

In this report a novel low temperature synthesis approach of CdS nanocrystals is described starting from well known precursors, Cd(SA) and TOP-S, in a ligand system of aliphatic long chain alcohols. A one-pot synthesis approach is applied using a laboratory microwave heating source. The resulting CdS nanocrystals exhibit an absorbance with a pronounced fine-structure, a photoluminescence with a very high ratio between the band gap peak and the defect peak and a fluorescence quantum yield of 33%. Different synthesis approaches have been investigated by changing heating rate, temperature, precursor concentration and chain length of the aliphatic alcohol ligand as well as chain length of the Cadmium precursor. It was found that small changes in the heating rate do not affect the reaction. Changing the reaction temperature between 200°C and 160°C has no visible effects on the quality of the resulting CdS nanocrystals. At 140°C the nanoparticles experience a significant drop in quality, probably because there is a major change in the growth mechanism of the nanocrystals at that low temperature. At 100°C and 120°C the creation of so-called CdS nanoclusters is observed, and a growth mechanism towards nanocrystals based on cluster aggregation is suggested. For the synthesis of high quality nanoparticles it was found that a ratio of 1:25 between precursor and aliphatic alcohol is preferable as well as a ratio of 1:1 between the two precursors. If the chain length of both the precursors and the alcohol is short, the reaction rate is enhanced. If the chain length is too short the nanocrystals grow very fast and the size distribution gets broad, the photoluminescence intensity decreases and the ratio between band gap luminescence and defect luminescence decreases. The best Cd-precursor was found to be Cd-Laurate and the most suitable ligand evaluated was Tetradecanol.