The aim of the research was to design and assess the effectiveness of a hope enhancement programme for a group of adults and the resulting influence on their general psychological well-being. The purpose of the programme was to increase hope, as conceptualised by Snyder et al. (1991), by enhancing participants' abilities to set feasible goals, planning ways to reach those goals (pathways) and increasing determination and motivation (agency) towards goal achievement. The workshop-format programme, presented by the researcher, consisted of six two-hour sessions spread over five days. The programme was developed through incorporating suggestions from existing Hope literature together with health psychological and positive psychology principles. In order to determine the impact of the programme, four measurement instruments were used, namely the Hope Scale, the Hunter Opinions and Personal Expectations Scale (HOPES), the Satisfaction with Life Scale (SWLS) and the Sense of Coherence scale (SOC-29). A pre and post-test design included an experimental group (n = 8), control group (n = 8) and 'chat' group (n = 8). Prior to group compilation, screening interviews were conducted with interested participants to exclude those who had recently experienced trauma or displayed overt signs of psychological pathology. The control group received no intervention, while the 'chat' group, of which the researcher was also a member, was allowed to discuss topics of their choosing. The study groups comprised both men and women of different ages and socio-economic status. All participants were White and Afrikaans speaking. Descriptive statistics, psychometric analysis of the measuring instruments and significant differences between groups were calculated with the assistance of the STATISTICA (version 6) computer programme (Statsoft Inc., 2003). Reliability indices compared well with those recorded in the literature for the various scales. For the experimental group, the findings indicated an increase in the hope levels as reflected by significant improvement on the Hope Scale and the Hopefulness subscale of the HOPES. Subjective feedback from the group confirmed these findings. Psychological well-being improved, as shown by a significant increase in Sense of Coherence (SOC-29) along with a positive change in Satisfaction with Life (SWLS). Neither the control nor experimental groups revealed any significant changes. It was established that the hope enhancement programme is effective in increasing the levels of hope and general psychological well-being of a group of adults relatively free of psychological pathology. Considering the findings, it is recommended that future wellness intervention should not focus solely on individuals with established psychological pathology, but also consider a preventative approach within the average population. / Thesis (M.A. (Clinical Psychology))--North-West University, Potchefstroom Campus, 2005.

The absorption enhancing ability of chitosan, a linear polysaccharide, is mediated by protonated amino groups on the C-2 position of the molecules that induce interaction with the anionic sites on the cell membranes to subsequently alter tight junction integrity. In neutral and basic environments, such as those found in the small and large intestines, most chitosan molecules will lose their charge and precipitate from solution rendering it ineffective as an absorption enhancer. To increase the solubility of this polymer, methylation of the amino groups on the C- 2 position was proposed. A partially quaternised and water soluble derivative of chitosan, N-trimethyl chitosan chloride (TMC), which exhibits superior solubility in a basic environment compared with other chitosan salts was synthesised and included in a chitosan microbead solid drug delivery system. Two TMC derivatives were synthesised by reductive methylation from high and medium molecular weight Chitoclear™ chitosan respectively. The degree of quaternisation calculated from the 1H-NMR spectra for the medium molecular weight TMC (TMC-M) and the high molecular weight TMC (TMC-H) polymers were 74.7 % and 48.5 % respectively. The mean molecular weights of the synthesised TMC-M and TMC-H polymers were 64 100 g/mole and 233 700 g/mole respectively. The effect of different concentrations TMC-M and TMC-H on chitosan microbeads was studied with results obtained from scanning electron microscopy (SEM), TMC loading capacity and microbead swelling behaviour. After selection of the most suitable TMC concentration, the effect of varying concentration (0.1, 0.2 and 0.5 %) additives on TMC and ibuprofen release was studied. Commonly used modified cellulose gum (Ac-di-sol®(ADS)), sodium starch glycolate (Explotab®(EXP)) and ascorbic acid (AA) were added as disintegrants to different microbead formulations to promote release of both the ibuprofen as model drug and TMC from the beads. It was noticed that the loading (% drug loading capacity) of TMC-M was much lower than that obtained with TMC-H while the inclusion of different additives in varying concentrations did not seem to have a profound influence on the loading of either TMC-M or TMC-H. It was further noticed from the fit factors (f1 and f2) for dissolution profiles of eighteen chitosan microbead variations that the formulation containing TMC-H and 0.5% (w/v) ascorbic acid was the only formulation with a significantly higher ibuprofen and TMC-H release profile compared to all other formulations tested. The chitosan microbead formulation containing 2%(w/v) TMC-H and 0.5 % (w/v) ascorbic acid (H-AA-0.5) was used for in vitro absorption studies through rat intestine in Sweetana-Grass diffusion chambers. Chitosan containing TMC-H (no ascorbic acid) (CHIT-H) only and a plain chitosan microbead (CHIT) formulation was used as control formulations during the in vitro studies. Although the H-AA-0.5 formulation exhibited the highest transport rate for ibuprofen, the mean rate of transport (P app) obtained from the two formulations containing TMCH (CHIT-H and H-AA-0.5) showed no significant difference in the transport rate of ibuprofen. Compared to the CHlT formulation as control, both formulations containing TMC-H exhibited increased ibuprofen transport across in vitro rat jejunum. However, a statistical significant increase in transport was obtained only from the H-AA-0.5 formulation in comparison with the CHlT formulation. It can be concluded that the combination of high molecular weight TMC with a low degree of quaternisation and ascorbic acid (0.5% w/v) in a chitosan microbead lead to a statistical significant increase in the in vitro transport rate of ibuprofen through rat jejunum. / Thesis (Ph.D. (Pharmaceutics))--North-West University, Potchefstroom Campus, 2006.

This work presents an experimental and numerical study of phase change behaviour in a horizontal cylindrical latent heat energy storage system (LHESS). Fins with two orientations, straight fins and angled fins, are added into the PCM to enhance heat transfer. The PCM used in this study is lauric acid which has desirable thermal properties for LHESS. The experimental work concentrates on studying the heat transfer mechanism during phase change, impacts of the HTF inlet temperature and HTF flow rates. Moreover, heat transfer enhancement effectiveness of straight fins and angles fins is compared. Numerical model is simulated using COMSOL Multiphysics software package. It is observed that conduction is the dominant heat transfer mechanism during the initial stage of charging, and natural convection plays a more important role afterwards. Conduction plays a major role during solidification. Complete melting time is affected by the HTF inlet temperature and HTF flow rates.

The goal of radiotherapy is to operate within the therapeutic window - delivering doses of ionizing radiation to achieve locoregional tumour control, while minimizing normal tissue toxicity. A greater therapeutic ratio can be achieved by utilizing radiosensitizing agents designed to enhance the effects of radiation at the tumour. Gold nanoparticles (AuNP) represent a novel radiosensitizer with unique and attractive properties. AuNPs enhance local photon interactions, thereby converting photons into localized damaging electrons. Experimental reports of AuNP radiosensitization reveal this enhancement effect to be highly sensitive to irradiation source energy, cell line, and AuNP size, concentration and intracellular localization. This thesis explored the physics and some of the underlying mechanisms behind AuNP radiosensitization. A Monte Carlo simulation approach was developed to investigate the enhanced photoelectric absorption within AuNPs, and to characterize the escaping energy and range of the photoelectric products. Simulations revealed a 10^3 fold increase in the rate of photoelectric absorption using low-energy brachytherapy sources compared to megavolt sources. For low-energy sources, AuNPs released electrons with ranges of only a few microns in the surrounding tissue. For higher energy sources, longer ranged photoelectric products travelled orders of magnitude farther. A novel radiobiological model called the AuNP radiosensitization predictive (ARP) model was developed based on the unique nanoscale energy deposition pattern around AuNPs. The ARP model incorporated detailed Monte Carlo simulations with experimentally determined parameters to predict AuNP radiosensitization. This model compared well to in vitro experiments involving two cancer cell lines (PC-3 and SK-BR-3), two AuNP sizes (5 and 30 nm) and two source energies (100 and 300 kVp). The ARP model was then used to explore the effects of AuNP intracellular localization using 1.9 and 100 nm AuNPs, and 100 and 300 kVp source energies. The impact of AuNP localization was most significant for low-energy sources. At equal mass concentrations, AuNP size did not impact radiosensitization unless the AuNPs were localized in the nucleus. This novel predictive model of AuNP radiosensitization could help define the optimal use of AuNPs in potential clinical strategies by determining therapeutic AuNP concentrations, and recommending when active approaches to cellular accumulation are most beneficial.

Many speech enhancement algorithms suffer from musical noise - an estimation residue noise consisting of music-like varying tones. To reduce this annoying noise, some speech enhancement algorithms require post-processing. However, a lack of auditory perception theories about musical noise limits the effectiveness of musical noise reduction methods. Scientists now have some understanding of the human auditory system, thanks to the advances in hearing research across multiple disciplines - anatomy, physiology, psychology, and neurophysiology. Auditory models, such as the gammatone filter bank and the Meddis inner hair cell model, have been developed to simulate the acoustic to neuron transduction process. The auditory models generate the neuron firing signals called the cochleagram. Cochleagram analysis is a powerful tool to investigate musical noise. We use auditory perception theories in our musical noise investigations. Some auditory perception theories (e.g., volley theory and auditory scene analysis theories) suggest that speech perception is an auditory grouping process. Temporal properties of neuron firing signals, such as period and rhythm, play important roles in the grouping process. The grouping process generates a foreground speech stream, a background noise stream, and possibly additional streams. We assume that musical noise is the result of grouping to the background stream the neuron firing signals whose temporal properties are different from the ones grouped to the foreground stream. Based on this hypothesis, we believe that a musical noise reduction method should increase the probability of grouping the enhanced neuron firing signals to the foreground speech stream, or decrease the probability of grouping them into the background stream. We propose a post-processing musical noise reduction method for the auditory Wiener filter speech enhancement method, in which we employ a proposed complex gammatone filter bank for the cochlear decomposition. The results of a subjective listening test of our speech enhancement system show that the proposed musical noise reduction method is effective. / Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2008-05-28 16:11:28.374

No description available.

No description available.

Eastern gamagrass [Tripsacum dactyloides (L.) L.] is a warm-season, perennial grass which is native to large areas across North America. Cultivars, selections and ecotypes suitable for erosion control, wildlife planting, ornamental, forage and biofuel applications are commercially available. Plantings are commonly established from seed; however, seed quality and dormancy are barriers to establishment. The objective here was to investigate parameters that contribute to inconsistent performance of this seed kind to subsequently improve seed lot quality. Forty-two seed lots were used, with seed fill and germination potential ranging from 78- 100% and 11-91%, respectively. Actual germination and dormant seed ranged from 0-40% and 1-85%, respectively. Seed count per pound ranged from 3195 to 8344 and was influenced by genotype. Alternating laboratory temperature regimes were generally more effective in promoting germination than constant temperatures. Optimal germination occurred at 15/25, 20/30 or 20/35 ºC (16/8 hours), but was not consistent across cultivars or seed lots. These data suggest that germination temperature contributes to inconsistent laboratory germination and poor stands observed for untreated and pretreated seeds sown under field conditions. Eleven primary dormancy breaking treatments were tested and most improved germination. Although not commercially feasible, cupule removal plus caryopsis scarification hastened germination and completely eliminated seed dormancy. Soaking in H2O2 (18 hr) improved germination, but the effect was not consistent. Moist chilling (5 or 10 °C) was generally superior to other treatments and remains the most simple, effective and consistent dormancy-breaking treatment, although duration varies by seed lot. Benefits of moist chilling and H2O2 treatment were retained for short periods in seeds dried from approximately 55% to 13% moisture content. Removal of empty and light-weight cupules improved seed lot purity and germination, although removal of as much as 40% of the volume was necessary. The priming treatments tested were less than satisfactory in improving germination or the range of germination temperatures compared to moist chilling treatment alone. Eastern gamagrass seed lot quality is highly variable, but can be improved. Multiple physical and physiological targets of opportunity have been identified to improve seed lot quality in eastern gamagrass.

This dissertation addresses the problem of employing 3D depth information on solving a number of traditional challenging computer vision/graphics problems. Humans have the abilities of perceiving the depth information in 3D world, which enable humans to reconstruct layouts, recognize objects and understand the geometric space and semantic meanings of the visual world. Therefore it is significant to explore how the 3D depth information can be utilized by computer vision systems to mimic such abilities of humans. This dissertation aims at employing 3D depth information to solve vision/graphics problems in the following aspects: scene understanding, image enhancements and 3D reconstruction and modeling. In addressing scene understanding problem, we present a framework for semantic segmentation and object recognition on urban video sequence only using dense depth maps recovered from the video. Five view-independent 3D features that vary with object class are extracted from dense depth maps and used for segmenting and recognizing different object classes in street scene images. We demonstrate a scene parsing algorithm that uses only dense 3D depth information to outperform using sparse 3D or 2D appearance features. In addressing image enhancement problem, we present a framework to overcome the imperfections of personal photographs of tourist sites using the rich information provided by large-scale internet photo collections (IPCs). By augmenting personal 2D images with 3D information reconstructed from IPCs, we address a number of traditionally challenging image enhancement techniques and achieve high-quality results using simple and robust algorithms. In addressing 3D reconstruction and modeling problem, we focus on parametric modeling of flower petals, the most distinctive part of a plant. The complex structure, severe occlusions and wide variations make the reconstruction of their 3D models a challenging task. We overcome these challenges by combining data driven modeling techniques with domain knowledge from botany. Taking a 3D point cloud of an input flower scanned from a single view, each segmented petal is fitted with a scale-invariant morphable petal shape model, which is constructed from individually scanned 3D exemplar petals. Novel constraints based on botany studies are incorporated into the fitting process for realistically reconstructing occluded regions and maintaining correct 3D spatial relations. The main contribution of the dissertation is in the intelligent usage of 3D depth information on solving traditional challenging vision/graphics problems. By developing some advanced algorithms either automatically or with minimum user interaction, the goal of this dissertation is to demonstrate that computed 3D depth behind the multiple images contains rich information of the visual world and therefore can be intelligently utilized to recognize/ understand semantic meanings of scenes, efficiently enhance and augment single 2D images, and reconstruct high-quality 3D models.

Numerous advancements made in the field of computational sciences have made CFD a viable solution to the modern day fluid dynamics problems. Progress in computer performance allows us to solve a complex flow field in practical CPU time. Commodity clusters are also gaining popularity as computational research platform for various CFD communities. This research focuses on evaluating and enhancing the performance of an in-house, unstructured, 3D CFD code on modern commodity clusters. The fundamental idea is to tune the codes to optimize the cache behavior of the node on commodity clusters to achieve enhanced code performance. Accordingly, this work presents discussion of various available techniques for data access optimization and detailed description of those which yielded improved code performance. These techniques were tested on various steady, unsteady, laminar, and turbulent test cases and the results are presented. The critical hardware parameters which influenced the code performance were identified. A detailed study investigating the effect of these parameters on the code performance was conducted and the results are presented. The successful single node improvements were also efficiently tested on parallel platform. The modified version of the code was also ported to different hardware architectures with successful results. Loop blocking is established as a predictor of code performance.