Turbulent wake flows: lie group analysis and conservation laws

A thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy. March 2016.We investigate the two-dimensional turbulent wake and derive the governing equations for the mean velocity components using both the eddy viscosity and the Prandtl mixing length closure models to complete the system of equations. Prandtl’s mixing length model is a special case of the eddy viscosity closure model. We consider an eddy viscosity as a function of the distance along the wake, the perpendicular distance from the axis of the wake and the mean velocity gradient perpendicular to the axis of thewake. We calculate the conservation laws for the system of equations using both closure models. Three main types of wakes arise from this study: the classical wake, the wake of a self-propelled body and a new wake is discovered which we call the combination wake. For the classical wake, we first consider the case where the eddy viscosity depends solely on the distance along the wake. We then relax this condition to include the dependence of the eddy viscosity on the perpendicular distance from the axis of the wake. The Lie point symmetry associated with the elementary conserved vector is used to generate the invariant solution. The profiles of the mean velocity show that the role of the eddy viscosity is to increase the effective width of the wake and decrease the magnitude of the maximum mean velocity deficit. An infinite wake boundary is predicted fromthis model. We then consider the application of Prandtl’s mixing length closure model to the classical wake. Previous applications of Prandtl’s mixing length model to turbulent wake flows, which neglected the kinematic viscosity of the fluid, have underestimated the width of the boundary layer. In this model, a finite wake boundary is predicted. We propose a revised Prandtl mixing length model by including the kinematic viscosity of the fluid. We show that this model predicts a boundary that lies outside the one predicted by Prandtl. We also prove that the results for the two models converge for very large Reynolds number wake flows. We also investigate the turbulentwake of a self-propelled body. The eddy viscosity closure model is used to complete the system of equations. The Lie point symmetry associated with the conserved vector is derived in order to generate the invariant solution. We consider the cases where the eddy viscosity depends only on the distance along the wake in the formof a power law and when a modified version of Prandtl’s hypothesis is satisfied. We examine the effect of neglecting the kinematic viscosity. We then discuss the issues that arisewhenwe consider the eddy viscosity to also depend on the perpendicular distance from the axis of the wake. Mean velocity profiles reveal that the eddy viscosity increases the boundary layer thickness of the wake and decreases the magnitude of the maximum mean velocity. An infinite wake boundary is predicted for this model. Lastly, we revisit the discovery of the combination wake. We show that for an eddy viscosity depending on only the distance along the axis of the wake, a mathematical relationship exists between the classical wake, the wake of a self-propelled body and the combination wake. We explain how the solutions for the combination wake and the wake of a self-propelled body can be generated directly from the solution to the classical wake.GR 201

Performative identity and the embodied avatar : an online ethnography of Final Fantasy XIV

This thesis explores the performative enactment of identity and embodiment through an online ethnography of the online game Final Fantasy XIV. It is argued that online identity must be viewed as performative, that is, enacted through speech and action, and embodied via the avatar, which acts as a body project for the player. The avatar identity is also constrained by the notion of authentic identity, which denotes how a single body is expected to hold a single identity. The thesis makes contributions to three areas. Firstly, in substantive terms, the thesis contributes original sociological knowledge of online social interaction, drawn from an online game and its related spaces, which remain under-researched sociologically. Secondly, the thesis makes a theoretical contribution through a theoretical framing of how online, embodied identity is achieved in an online game in a performative fashion, which is centred on the body of the avatar, coupled with the speech and actions of the player. Finally, the thesis also offers a methodological contribution through its original use of photo elicitation in online interviews, and furthers the debates around (online) ethnography. An 11 month programme of fieldwork was undertaken, comprising 36 asynchronous, image elicitation interviews, extensive participant observation of the game over the 11 months, and observation of the official forum lasting nearly six months. The thesis concludes that online identity and embodiment in these spaces are heavily constrained by norms drawn from everyday life, such as heteronormativity, and racism. The game design is also influenced by the developers‟ norms and values, such as the avatar appearance. The possibilities for performative identity and embodiment are severely constrained by the community, who reify the game space as separate from “real” life and reject the inclusion of non-normative avatars

Pharmacy Curriculum Outcomes Assessment (PCOA) as Predictor of Performance on NAPLEX

Objectives: The purpose of the study was to respond to students’ inquiry regarding the relationship between student performance on the PCOA administered in early spring of the P3 year and performance on the NAPLEX administered post-graduation. Method: PCOA scores for two of the four content areas, Pharmaceutical Sciences and Clinical Sciences, resulting from administration of the assessment for P3 students in 2012 and 2013 were compared to the same student scores for the 2013 and 2014 NAPLEX taken post-graduation. A Pearson product-moment correlation coefficient was calculated to measure the linear correlation between the two sets of exam scores. Additionally, a linear regression was used to explain the predictor, PCOA, variability on the NAPLEX Score. Results: The Pearson product-moment correlation coefficient for the combined PCOA content areas, Pharmaceutical Science and Clinical Science scores, was r=.572. A linear regression established that PCOA Pharmaceutical Science and Clinical Science scores could statistically significantly predict NAPLEX scores, p Implications: Students taking the PCOA exam in the P3 year of their PharmD program may find value in using their performance on the assessment in the areas of Pharmaceutical Science and Clinical Science to predict their performance on the NAPLEX which is blueprinted to these areas of study

The Effect of Different Waxing Technologies on Shelf Life of ‘Apple’ Mango Fruits Stored Under Different Storage Conditions

Beneficial effect of Shellac and Mango wax of different formulations was studied on shelf life of apple mango fruits which were harvested at mature green stage and stored in various storage conditions including ambient (25ºC) and simulated commercial cold storage (12ºC).  Mango wax (one mixed with a fungicide and another without) was obtained from United Phosphorous Limited, while Shellac wax was purchased from a commercial trader in flakes form and dissolved in 0.1N Sodium hydroxide to make two concentrations (3% and 5%). The two waxes were applied by dipping the fruits in a bowl of wax and placing them on wire mesh for air drying using fans. Upon drying the fruits were packed in open cotton boxes and stored in ambient (25ºC) and cold storage (12ºC). Three fruits from each treatment and different storage conditions were sampled after every 3 and 7 days (ambient and cold storage respectively) for measurement of attributes associated with ripening including weight loss, respiration rate, peel firmness and pulp hue angle.  Results indicated that waxing whether with Shellac or Mango wax was effective in extending shelf life of mango fruits for 4 and 6 more days in ambient and cold storage respectively. At the end of observation period, un waxed fruits in ambient and cold storage had lost 12.4% (day10) and 5.5% (day 22) compared to an average of 7.6% (day14) and 3.7% (day 28) for the waxed fruits respectively.  Waxed fruits exhibited low respiration peak of 49.39 and 30.38 ml/kg/hr compared to un waxed fruits that had a high peak of 85.09 and 43.15 ml/kg/hr for ambient and cold storage respectively signifying high respiratory activity in the un waxed fruits. Other ripening related parameters had a positive correlation to respiration and water loss. This study shows that coating of mango fruit with wax is effective in delaying ripening thereby extending its postharvest life. Keywords: Mango wax, Shellac wax, Shelf life, Mango, Postharvest technologies, Storag

A Mathematical Model of Black Rhino Translocation Strategy

A deterministic mathematical model of the black rhino population in South Africa will be discussed. The model is constructed by dividing the black rhino population into multiple patches. The impact of human intervention on different translocation strategies is incorporated into the model. It is shown that, when implemented correctly, translocation can accelerate the growth rate of the total black rhino population. Equilibrium points are shown with their local stability criteria

Low-intensity educational interventions supporting self-management to improve outcomes related to chronic breathlessness: a systematic review

Chronic breathlessness is debilitating and frightening, often resulting in emergency department presentations with acute-on-chronic breathlessness. Self-management is complex, involving 14 components as identified by the Practical Systematic Review in Self-Management Support (PRISMS). Low-intensity educational interventions that support breathlessness self-management through written/visual educational materials, alongside limited health professional support, are available. Our aim was to describe components of low-intensity educational interventions that support and improve self-management for adults with chronic breathlessness and evaluate their efficacy for improving breathlessness-related outcomes. A systematic review was conducted, including RCTs that compared these interventions with usual care in adults with chronic disease. Synthesis took a narrative approach utilizing the PRISMS taxonomy and Template for Intervention Description and Replication (TIDieR) checklist. Of the 1948 articles identified, 7 met criteria reporting 7 RCTs using 6 interventions. Studies utilized 12 out of 14 PRISMS components, the most frequent being training/rehearsal for psychological strategies. Evidence for effectiveness was inconsistent and attempts to identify beneficial components were confounded by intervention complexity and heterogeneity. The optimal content and delivery of low-intensity educational interventions that support self-management to improve chronic breathlessness-related outcomes in adults cannot be defined from current published literature. Future research should incorporate more detailed, standardized reporting to enable comparison and meta-analysis

The management of sexually transmitted infections: a scoping survey in primary care

Background National guidelines for sexually transmitted infections (STIs) in primary care exists but their management is uncertain. Aim To assess the management of STIs against national standards in primary care. Design & setting A questionnaire based study in London and Brighton. The survey was conducted in 2015 following reorganisation of sexual health services in England. Method Questionnaires were sent to GPs in London and Brighton about testing for STIs, treatment for gonorrhoea, specialist advice, and referral services. Results Of 119 GPs who responded, most expressed confidence in treating chlamydia (n = 105/119, 88%), trichomonas (n = 81/119, 68%), and herpes (n = 82/119, 69%) but not gonorrhoea (n = 32/119, 27%). Most referred cases of syphilis (n = 92/119, 77%) and genital warts (83/119, 70%) to genito-urinary medicine (GUM) as per guidance. Most GPs tested for gonorrhoea on patient request (n = 95/119, 80%), in tandem with chlamydia screening (n = 89/119, 75%), because of high risk status (n = 85/119, 71%) and genital symptoms (n = 108/119, 91%). Some GPs (n = 22/119, 18%) sampled urine for culture, 53/119 (45%) provided high vaginal swabs (HVS), and 28/119 (24%) provided self-taken vulvovaginal swabs (STVVS) for culture. These samples are not appropriate for gonococcal culture and not processed in the laboratory. Urethral swabs for men and endocervical swabs (ECS) are recommended for gonococcus culture. Over half (n = 60/102, 59%) of GPs did not treat gonorrhoea but some prescribed cefixime, ciprofloxacin, or azithromycin. Eighty-seven per cent (n = 104/119) sought advice from GUM, and 83/103 (81%) referred gonorrhoea nucleic acid amplification test (NAAT)-positive patients. Conclusion There is scope for improvement of STIs management in primary care to ensure that patients are optimally investigated, treated, and referred

Taxonomy and conservation of grassland earless dragons:New species and an assessment of the first possible extinction of a reptile on mainland Australia

Taxonomic research is of fundamental importance in conservation management of threatened species, providing an understanding of species diversity on which management plans are based. The grassland earless dragon lizards (Agamidae: <i>Tympanocryptis</i>) of south-eastern Australia have long been of conservation concern but there have been ongoing taxonomic uncertainties. We provide a comprehensive taxonomic review of this group, integrating multiple lines of evidence, including phylogeography (mtDNA), phylogenomics (SNPs), external morphology and micro x-ray CT scans. Based on these data we assign the lectotype of <i>T. lineata</i> to the Canberra region, restrict the distribution of <i>T. pinguicolla</i> to Victoria and name two new species: <i>T. osbornei sp. nov.</i> (Cooma) and <i>T. mccartneyi sp. nov.</i> (Bathurst). Our results have significant conservation implications. Of particular concern is <i>T. pinguicolla</i>, with the last confident sighting in 1969, raising the possibility of the first extinction of a reptile on mainland Australia. However, our results are equivocal as to whether <i>T. pinguicolla</i> is extant or extinct, emphasizing the immediate imperative for continued surveys to locate any remaining populations of <i>T. pinguicolla</i>. We also highlight the need for a full revision of conservation management plans for all the grassland earless dragons

Assuaging death anxiety in older overseas-born Australians of culturally and linguistically diverse backgrounds hospitalised for end-of-life care

BACKGROUND: Death anxiety is a known phenomenon in older people of culturally and linguistically diverse backgrounds (CALD) hospitalised for end-of-life (EOL) care . Little is known about how nurses assuage death anxiety in this population. AIMS: To investigate strategies used by nurses to assuage death anxiety and facilitate a good death in older CALD Australians hospitalised for EOL care. METHODS: Advanced as a qualitative descriptive inquiry, a purposeful sample of 22 nurses was recruited from four Victorian healthcare services. Interviews were transcribed verbatim and analysed using thematic analysis processes. FINDINGS: Nurses used three key strategies: recognising death anxiety; delineating its dimensions; and initiating conventional nursingcaring behaviours to help contain it. Contrary to expectations, cultural similarities rather than differences were found in the strategies used. CONCLUSIONS: Nursing strategies for recognising, delineating, and managing death anxiety in older CALD people hospitalised at the EOL is an important component of quality EOL care

Nursing strategies for engaging families of older immigrants hospitalized for end-of-life care: an Australian study

BACKGROUND: Engaging with families of older non-English-speaking background (NESB) immigrants hospitalized for end-of-life (EOL) care can be challenging, especially when their cultures, lifeways, and family decision-making processes are unfamiliar to the nurses caring for them. Despite the recognized importance of family engagement when providing EOL care, the issue of ethnic minority family engagement has received little attention in the field. AIM: To explore and describe the strategies nurses use to facilitate engagement with families of older immigrant NESB patients hospitalized for EOL care. METHODS: A qualitative descriptive approach was used. Data were collected via in-depth interviews conducted with 22 registered nurses recruited from 4 Australian health services. FINDINGS: Using thematic analysis processes, 5 key strategies were identified: listening and understanding families, encouraging family members to speak first, dealing with angst, redressing naive views about the dying process, and managing intergenerational differences. Underpinning these strategies was a profound &quot;will to engage&quot; with the families and their cultural worldviews. CONCLUSION: Further cross-cultural comparative research is required to inform evidence-based policies, practice, and education on this issue