Blood flow and its payload of molecular oxygen are two parameters of most physiological interest. Systemic tissue health is routinely gauged through measurements of vitals and oxygen saturation to estimate the state of these physiological parameters. We design, develop, and deploy optical imaging systems for examining perfusion and oxygenation at the local tissue level and apply these techniques for elucidating the normal and pathological processes associated with neurovascular disease. Specifically, we develop and validate the ability to use Multi-Exposure Speckle Imaging (MESI) to estimate microvascular flow dynamics in rodents over acute and chronic periods. Next, we pose significant optimizations to improve the efficacy of the widefield imaging technique for adoption by bench-side and clinical perfusion studies. We also introduce re-interpretations of the underlying physics to advance the theory that quantifies motion from the imaged speckle patterns. Finally, the technique is deployed for chronic monitoring of cortical flow dynamics before after focal ischemia of the motor cortex as part of a behavioral study in rodents. At the microscale, we develop and validate Two Photon Phosphorescence Lifetime Microscopy (2PLM) to examine dissolved oxygen concentration in microvasculature in three dimensions. We examine the technique’s ability for functional mapping of the rodent cortical microvascular network by quantifying the partial pressure of oxygen (pO₂) before and after occlusion of critical arterioles. Automation of acquisitions and processing for robust oxygen mapping within the micro-vascular network are developed and evaluated. The in vivo results are presented in light of those from studies utilizing more invasive mapping electrodes to provide independent corroboration of the observed neurovascular oxygen distributions. The technique is deployed for examining high resolution functional and structural remodeling after focal cerebral ischemia. / text

Automated Material Handling Systems are practically ubiquitous across industry and many rely on the operation of timing belt drives, which require that the belt be tensioned properly in order to function correctly. A series of experiments was carried out in which the frequency spectrum of acoustic radiation caused by transverse vibrations of a timing belt was used to calculate the belt tension. A lumped-parameter model was developed that considers the geometric complexity of the timing belt's construction by calculating the stiffness of a single belt tooth using commercially-available finite element analysis software. This was used to modify the belt's effective stiffness suggested by the manufacturer. Based on the experimental data, a set of material properties was determined that, when used in the lumped-parameter model, resulted in tension predictions that agreed with the experiment within the 95% confidence intervals of the means. / text

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The two interconnected rubber balloons system is a demonstration widely used to show the effect of surface tension; however, the nature of the rubber skin, sizes of the balloons limit the ability of this demonstration. In this research, I measured the circumference and pressure of balloons for the calculation of surface tension. It was found that the demonstration can be done between circumferences of 30 cm to 50 cm for the party balloons to show the effect of surface tension as explained by the Laplace-Young equation.

The proposed tension measurement method focuses on measurement of tension in a single belt span of the multi-pulley Front End Accessory Drive (FEAD) system. The mean belt span tension is calculated from the measured belt span natural vibration frequency. The oscillation belt span tension is calculated from the measured belt span transverse displacement. The dynamic belt span tension is calculated using the mean and oscillation tensions, belt span support pulley rotations, and belt slip, where the slip equation is based on Euler's equation. The proposed tension measurement method is validated using an experimental testing FEAD system which consists of a five pulley system and an automatic tensioner arm. Non-contact sensors are used to prevent disruption of the typical system behaviour. Testing conditions simulate typical engine crankshaft rotation input. Results from experimental testing consistently produce results with percent error less than 10 % for mean and maximum belt span dynamic tension.

Dissertation submitted in partial compliance with the requirements for the Masters Degree in Technology: Chiropractic, Durban University of Technology, 2010. / The 1 year overall prevalence of Episodic Tension-Type Headache (ETTH) is 38.3%; with lifetime prevalence at 46% for TTH. Little literature exists to support the effectiveness of spinal manipulation in the treatment of ETTH. Therefore aim of this study was to determine the relative effectiveness of cervical spine manipulation and a Nonsteroidal Anti-inflammatory drug (NSAID) (Ibuprofen®) in the treatment of ETTH. Method: This study was a prospective randomised clinical trial with two intervention groups (N=32, n1=16 and n2=16). The allocation of participants to the two groups was completed by means of simple randomization. Group one were treated using cervical spine manipulation. Group two were treated using Ibuprofen. Subjective measurements included the Numerical Rating Scale 101 Questionnaire (NRS-101), Short Form McGill Pain Questionnaire (SF-MPQ), CMCC Neck Disability Index (CMCC) and Headache Diary. A p value <0.05 was considered as statistically significant. Results: The subjective measurements of the NRS-101, SF-MPQ and CMCC showed a significant time effect in both treatment groups. Several of the subjective Headaches Diary outcomes followed this trend with significant time effect in both groups. There was a significant treatment effect for the NRS-101. Several subject outcomes from the Headache Diary showed a significant treatment effect in favour of manipulation, namely frequency and duration of headaches. Conclusion: The findings in this study have shown that cervical spine manipulation is more effective than Ibuprofen® for the treatment of ETTH in terms of several subjective outcomes namely: pain intensity (NRS-101), and the frequency and the duration of headache per day.

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Glass Fibre-Reinforced Polymer (GFRP) bars offer a feasible alternative in locations where steel is not the suitable reinforcement; namely locations that are sensitive to corrosion. In this study 60 specimens, 52 GFRP reinforced and 8 steel reinforced, were constructed and tested under direct tension in order to investigate the tension stiffening and cracking behaviour. The effects of different variables such as the bar type, the bar diameter, the reinforcement ratio and the concrete strength on tension stiffening and crack spacing were studied. The current code provisions for tension stiffening, namely ACI-440 and CEB-FIP were evaluated against the obtained test data. It was determined that the current code provisions significantly overestimate tension stiffening in GFRP reinforced specimens. A new tension stiffening model was, therefore, developed that provides better simulation of the test data. The CEB-FIP 1978 model for crack spacing was also modified for GFRP reinforced members.

Glass Fibre-Reinforced Polymer (GFRP) bars offer a feasible alternative in locations where steel is not the suitable reinforcement; namely locations that are sensitive to corrosion. In this study 60 specimens, 52 GFRP reinforced and 8 steel reinforced, were constructed and tested under direct tension in order to investigate the tension stiffening and cracking behaviour. The effects of different variables such as the bar type, the bar diameter, the reinforcement ratio and the concrete strength on tension stiffening and crack spacing were studied. The current code provisions for tension stiffening, namely ACI-440 and CEB-FIP were evaluated against the obtained test data. It was determined that the current code provisions significantly overestimate tension stiffening in GFRP reinforced specimens. A new tension stiffening model was, therefore, developed that provides better simulation of the test data. The CEB-FIP 1978 model for crack spacing was also modified for GFRP reinforced members.