The purpose of this research was to determine uni-axial response of synthetic fibres required for structural design. The stress versus crack opening curves, required by RILEM for structural design of fibre reinforced concrete, were determined for each fibre type investigate and were used to compare the per fibre post-crack response, the pullout curves, and the flexural response. A study of the fibre distribution was conducted in order to determine the orientation factor required to predict the number of fibres expect in the tensile specimen crack face. The orientation factor, dosage, fibre geometry, and per fibre post-crack response were determined in order to predict the resulting tensile strength of a concrete mix. The tensile strength was compared to that of steel fibre currently being used in structural applications. The synthetic fibres tested only achieve a small percentage of their ultimate tensile strength; in order to produce synthetic fibres for structural applications, the bond strengths must be improved.

Despite nursing’s espoused professional values of caring and social justice, some patients are stigmatized and receive discriminatory nursing care. There is a gap in existing literature about how nurses deal with the tension they experience when personal and professional values collide. The purpose of this study was to generate a substantive theory of the process that nurses use when faced with values tension in clinical practice and how this affects their behaviour. Using constructivist grounded theory methodology informed by symbolic interactionism and critical social theory, the theory of Juggling a Way of Being was co-constructed with data obtained through interviews with registered nurses (n=8) who provide frontline care in an emergency department in Atlantic Canada. The study’s findings revealed a process fraught with tension as nurse participants assimilated internal and external stressors, adjusted the patient-centered/nurse-centered lens according to their interpretation of the situation, and achieved a point of action or inaction. Implications for nursing practice and administration, education and research are discussed.

Neonatal respiratory distress syndrome (RDS) is a disease that affects premature infants born prior to 32 weeks gestation. The main cause is a deficiency in pulmonary surfactant due to immature type II pneumocyte cells found in the alveoli. These cells are not capable of producing the required surfactant which normally functions to reduce the surface tension at the air-liquid interface of the lungs, as well as reduce the work of breathing and prevent alveolar collapse. A current treatment method for RDS is exogenous surfactant replacement therapy involving application of an exogenous surfactant preparation directly into the lungs of premature infants. Current surfactant preparations are animal-derived and very costly. Synthetic preparations, on the other hand, are an attractive alternative. The goal of this research is to synthesize a diether phosphonolipid analogue of dipalmitoyl phosphatidylcholine (DPPC), designated DEPN-8. When incorporated into a synthetic exogenous surfactant mixture, DEPN-8 exhibits greater adsorption and surface activity compared to its natural counterpart, DPPC. The synthesis of several components related to the re-tailored synthesis of DEPN-8 will be presented and discussed below. / National Institute of Health, NSERC

No description available.

Dissertation submitted in partial compliance with the requirements for a Masters Degree in Technology: Chiropractic, Durban University of Technology, 2009. / Headaches are one of the most common clinical conditions in medicine, and 80% of these are tension-type headaches (TTH). TTH has a greater socioeconomic impact than any other type of headache due to its prevalence. Within the TTH category, episodic TTH are more prevalent than chronic TTH. The mainstay in the treatment of TTH are simple analgesics and NSAIDs. Unless contraindicated, NSAIDs are often the most effective treatment for ETTH. However patients suffering with TTH tend to relate their headaches to increased muscle stiffness in the neck and shoulders and thus the non-pharmacological treatment of ETTH could be directed at the associated musculoskeletal components of ETTH. It is therefore proposed that the Kinesio Taping® Method may have an effect in the treatment of the muscular component of ETTH. Method: This study was a prospective randomised clinical trial with two intervention groups (n=16) aimed at determining the relative effectiveness of a NSAID and the Kinesio Taping® Method in the treatment of ETTHs. The patients were treated at 5 consultations over a 3 week period. Feedback was obtained using the: NRS – 101, the CMCC Neck Disability Index and a Headache Diary. Results: The Headache Diary showed a reduction in the presence and number, mean duration and pain intensity of ETTH in both groups. These treatment effects were sustained after the cessation of treatment with the exception of mean pain intensity in the Kinesio Taping® Method group. The mean NRS score decreased in both groups but at a slightly faster rate in the Kinesio Taping® Method group. The CMCC showed an improvement in the functional ability of the patients in both groups. Conclusion: There seems to be no significant difference in the relative effectiveness of the treatment modalities. We can thus state that the overall short-term reduction in symptomatology supports the use of NSAIDs or Kinesio Taping® Method in the treatment of ETTH.

Noninvasive measurements of myocardial carboxymyoglobin levels (%MbCO) and oxygen tensions (PtO2) are difficult to obtain experimentally. We have developed a compartmental model which allows prediction of myocardial %MbCO levels and PtO2 for varied carbon monoxide (CO) exposures. The cardiac compartment in the model consists of vascular subcompartments which contain two tissue subcompartments varying in capillary density. Mass-balance equations for oxygen (O2) and CO are applied for all compartments. Myocardial oxygen consumption and blood flow are quantified from predictive formulas based on heart rate. Model predictions are validated with experimental data at normoxia, hypoxia, exercise and hyperoxia. CO exposures of varying concentration and time (short-high, long-low), CO rebreathing during 100% O2, and exposure during exercise is simulated. Results of the simulations demonstrate that during CO exposures and subsequent therapies, the temporal changes of %MbCO in the heart differ from those of carboxyhemoglobin levels (%HbCO). Analysis of correlation between %HbCO, %MbCO and PtO2 was done to understand myocardial injury due to CO hypoxia. This thesis demonstrates that the model is able to anticipate the uptake and distribution of CO in the human myocardium and thus can be used to estimate the extravascular burden (MbCO, PtO2 ) of CO on the human heart.

This paper examines five cooperative board games from the perspective of how randomization is used and how it affects the replayability and player strategy, with the intent to properly identify and categorize elements that contribute to replayability and tension and uses randomization to do so. Each element directly affected by or causes randomization is identified, explained (both what it does and how and what it affects), and categorized based on where in the game the randomization originates in the effort to create a base for game designers to get a better understanding of randomization, if and how they can use it, and which method of using it that can be useful for their own designs.The thesis discusses the impact of using certain randomization elements and draws some conclusions based on how they relate to the replayability and tension of games that use those elements.

The objective of this thesis was to further develop a methodology for surface tension measurement called Axisymmetric Drop Shape Analysisn(ADSA) and to adapt it to studies of lung surfactants, i.e. the material that coats and facilitates the functioning of the lungs of all mammals. The key property of a functioning lung surfactant is its surface tension, which can reach extremely low values. Such values are difficult to measure; but a certain configuration of ADSA, using a constrained sessile drop (ADSA--CSD), is capable of performing such measurements. Clinically, lung surfactant films can be altered from both sides, i.e. from the airspace as well as from the bulk liquid phase that carries the film. Therefore, being able to access the interface from both sides is important. Here, ADSA--CSD was redesigned to be used as a micro film balance allowing access to the interface from both gas- and liquid-side. This allows deposition from the gas side as well as complete exchange of the bulk liquid phase. The new design was used to study lung surfactant inhibition and inhibition reversal. A dynamic compression-relaxation model (CRM) was developed to describe the mechanical properties of lung surfactant films by investigating the response of surface tension to changes in surface area. The model evaluates the quality of lung surfactant preparations -- beyond the minimum surface tension value -- and calculates the film properties, i.e. elasticity, adsorption and relaxation, independent of the compression protocol. The accuracy of the surface tension measurement can depend on drop size. A detailed analysis of drop shapes and accuracy of measured surface tension values was performed using a shape parameter concept. Based on this analysis, the design of ADSA--CSD was optimized to facilitate more accurate measurements. The validity analysis was further extended to the more conventional pendant drop setup (ADSA--PD). An overall upgrade of both hardware and software of ADSA--CSD, together with extensive numerical work, is described and applied to facilitate a more efficient operation. Finally, it is noted that the ADSA--CSD setup developed here can be used for a wide range of colloid and surface chemical applications.

In the present study a parallel three dimensional Volume of Fluid (VOF) method is developed to simulate Marangoni force in immiscible fluids with variable surface tension. Conservation equations are solved based on cell-averaged one-field volume tracking scheme. Evaluating the convective term in the energy equation along the boundary between the fluids highly depends on the position and orientation of the interface; hence, using average cell values simply ignores the interface shape and leads to computational uncertainty. As a remedy to this issue, the original idea behind the volume tracking method is used not only to advect mass and momentum but also energy across cells. To verify the proposed algorithm, results are compared against theoretically predicted thermocapillary migration velocity of a droplet at the limit of zero Marangoni number. However, at relatively high Marangoni numbers, thermal boundary layers are very thin and challenging to resolve. To demonstrate the capabilities of the heat transfer module, simulations of a Fluorinert droplet moving in silicon oil under applied temperature gradient in microgravity are compared against the available experimental results and the migration velocity of the droplet are reported.

The objective of this thesis was to further develop a methodology for surface tension measurement called Axisymmetric Drop Shape Analysisn(ADSA) and to adapt it to studies of lung surfactants, i.e. the material that coats and facilitates the functioning of the lungs of all mammals. The key property of a functioning lung surfactant is its surface tension, which can reach extremely low values. Such values are difficult to measure; but a certain configuration of ADSA, using a constrained sessile drop (ADSA--CSD), is capable of performing such measurements. Clinically, lung surfactant films can be altered from both sides, i.e. from the airspace as well as from the bulk liquid phase that carries the film. Therefore, being able to access the interface from both sides is important. Here, ADSA--CSD was redesigned to be used as a micro film balance allowing access to the interface from both gas- and liquid-side. This allows deposition from the gas side as well as complete exchange of the bulk liquid phase. The new design was used to study lung surfactant inhibition and inhibition reversal. A dynamic compression-relaxation model (CRM) was developed to describe the mechanical properties of lung surfactant films by investigating the response of surface tension to changes in surface area. The model evaluates the quality of lung surfactant preparations -- beyond the minimum surface tension value -- and calculates the film properties, i.e. elasticity, adsorption and relaxation, independent of the compression protocol. The accuracy of the surface tension measurement can depend on drop size. A detailed analysis of drop shapes and accuracy of measured surface tension values was performed using a shape parameter concept. Based on this analysis, the design of ADSA--CSD was optimized to facilitate more accurate measurements. The validity analysis was further extended to the more conventional pendant drop setup (ADSA--PD). An overall upgrade of both hardware and software of ADSA--CSD, together with extensive numerical work, is described and applied to facilitate a more efficient operation. Finally, it is noted that the ADSA--CSD setup developed here can be used for a wide range of colloid and surface chemical applications.