3,154 research outputs found
The impact of social housing developments on nearby property prices: A Nelson Mandela Bay Case Study
Social housing projects often face substantial “Not-in-my-backyard†(NIMBY) sentiment and as a result are frequently plagued by local opposition from communities who argue that nearby property prices will be affected adversely by these developments. International hedonic pricing studies conducted have, however, produced mixed results with some concluding that social housing developments may in fact lead to an improvement in surrounding property values. There is, however, a paucity of South African evidence. This study considers the validity of the most pervasive NIMBY argument, the claim that social housing developments negatively affect nearby property values, by considering the property prices of 170 single-family homes in the Walmer neighbourhood, Nelson Mandela Bay, as a function of their proximity to an existing low-cost housing development. The results of this study indicate that in the case of one Nelson Mandela Bay low-cost housing development, a negative impact is exerted on the property values of nearby houses.
Caring for people living with AIDS
This paper discusses the concept of care and its implementation with reference to caring for people living with AIDS (PLWA) as 'a labour of love'. The first part of the paper elaborates on care as love, an emotion, and care as labour, an activity, followed by a discussion on four interconnected phases of care, namely 'caring about', 'taking care of', 'care-giving' and 'care-receiving' and the requirements for 'good' care. The gendered nature of care and the resources required for adequate quality care are also discussed. The emphasis in this paper is on the arrangement of care for PLWA, at the micro-level of the household as provided by family and community members, while recognising the role of the state and the market in care provision. This framework is applied to cases from non-urban KwaZulu-Natal in South Africa. The cases, presented according to the four phases of care, not only illustrate care for PLWA as emotion and hard work, but also reveal the gendered nature of care and the resources required to provide quality care. The discussion, the last part of the paper, reflects on care as emotion and care as work and what it entails for different gender groups in this cultural setting characterised by limited access to especially economic resources, where social capital proved to be a crucial resource for the PLWA to access care. It also goes beyond the four phases of care by incorporating the experiences of the caregiver and her/his response to the feedback received from the care receiver
The factors influencing Mathematics students to choose teaching as a career
Prompted by the poor state of mathematics education in South Africa and the shortage of competent mathematics teachers, this study sought to identify what factors influenced 40 Postgraduate Certificate in Education (PGCE) students at three universities in the Western Cape Province, with Mathematics as a major subject, to choose teaching as a career. The respondents were asked to articulate reasons for their career choice by answering an open-ended question and completing an internationally validated FIT-choice questionnaire. The motivations presented in the questionnaire are based on the concepts of Self-efficacy, Self-determination Theory (SDT) and Expectancy Value Theory (EVT). The research has shown that student responses regarding their motivations were remarkably consistent, regardless of the respondents’ home language or social class. Student rating choices were based mainly on intrinsic motivations. The study concludes, therefore, that understanding student choices with respect to Mathematics teaching as a career will assist in the planning and management of the recruitment and retention of quality Mathematics teachers. It is clear from this research that when student teachers with intrinsic motivation are identified and recruited, they will be more likely to perceive teaching as a lifelong career choice.Keywords: career choice; factors; mathematics teachers; motivation; recruitment; retentio
Effect of graphitization on the static mechanical properties of service exposed ASTM A516 Gr. 65 steam pipe metal
The focus of this research project is to establish what effect graphitization has on the static mechanical properties of service exposed ASTM A516 Grade 65 steam pipe material, which operated for prolonged periods above 425 ̊C. The research study was conducted on three graphitized service exposed steam pipe weldment samples and on a newly welded and post weld heat treated sample with graphitized service exposed steam pipe material. Macro samples were removed from each of the samples at two positions and these were evaluated with regard to graphite nodule size, nearest neighbour spacing and % planar graphitization in the parent pipe and HAZ regions on either side of the welds. It was found on all of the service exposed samples that the graphite nodules of the HAZ regions have a smaller median nodule size, smaller median nearest neighbour spacing and increased % planar graphitization in comparison to the parent pipe material. The service expose parent pipe material on either side of the weldments of the respective samples was chemically analyzed. This was done with the focus being on the deoxidizing element content (Si and Al) of the respective parent pipe regions and to what extent these elements influenced the development of planar graphitization in these regions. No correlation could be identified between the level of deoxidizing elements and the levels of % planar graphitization in the parent pipe material. Tensile and Charpy impact samples were removed from the respective service exposed samples parent material on either side of the weld and from the HAZ regions on the side with the highest levels of planar graphitization. These samples were tested and the yield and ultimate tensile strength and Charpy impact toughness of the respective samples were then evaluated to establish how these static mechanical properties were influenced by the % planar graphitization. The yield and ultimate tensile strength of the service exposed material did not show a statistically significant correlation with the % planar graphitization. The Charpy impact toughness results did however show a statistically significant negative correlation towards the % planar graphitization. This was clearly evident from the results of the HAZ regions of the service exposed weldments (Samples A-C) which had the highest levels of % planar graphitization and the lowest impact toughness, while the newly welded and post weld heat treated Sample D had no planar graphitization outside the HAZ and the highest impact toughness. This research project not only investigated how planar graphitization affects the static mechanical properties of service exposed pipe material, it also investigated on a microstructural basis, how planar graphitization nucleates and grows. The microstructural investigation showed that the free carbon required for the development of planar graphitization originated from the regions outside the HAZ, which were formed when the pearlite bands were dissolved during the welding of the steam pipe. The heat input from the welding sensitized this region for the development of planar graphitization, probably due to the formation of a “carbon-rich” matrix due to the partial dissolution of the cementite precipitates. All the carbide precipitates in this region consisted of M3C. aluminium-rich precipitates were found inside newly nucleated graphite nodules, indicating its role as a possible heterogeneous nucleation site. Growth of newly formed graphite nodules showed a preference towards high-angle grain boundaries and regions with dislocations for the initial growth stages of the graphite nodules. The microstructure of the region outside the HAZ of the newly introduced seam weld on the service exposed steam pipe material (with graphitization), was also investigated using advanced electron microscopy methods and it yielded no evidence of the development of planar graphitization
Pediatric Chest X-rays
Chest Radiographs are the most commonly ordered diagnostic image in the pediatric population. These images are encountered often in both the early medical school curriculum and outside in the clinical setting. This module was generated with the goals of giving a framework for approaching pediatric chest x-rays, as well as showcasing common radiographic findings, both normal and pathologic
A comparative study of ROTEM-EXTEM results obtained from EDTA-treated whole blood samples and Sodium Citrate-treated whole blood samples in healthy volunteers
Background: A number of anticoagulants are available in clinical use to preserve blood samples in liquid form until a suitable time for laboratory testing. Rotational thromboelastography is usually performed on a blood sample that has been anticoagulated with sodium citrate and then recalcified immediately prior to testing. In our institution we have had shortages of citrated Vacutainer® sample tubes. The use of a single in vitro anticoagulant promises to cut costs, simplify laboratory processes as well as limit the amount of blood drawn from patients. This together with the known problems with using citrate as an anticoagulant for viscoelastic testing (VET) prompted us to investigate the suitability of EDTA as anticoagulant for VET. Method: Blood samples from 20 healthy volunteers were divided into citrated and EDTA Vacutainer® tubes. A ROTEM EXTEM® assay was performed on each sample in both groups following the manufacturer's guidelines. Clotting time (CT), clot formation time (CFT), alpha angle (α-angle) and maximum clot firmness (MCF) results were compared. Ionised calcium concentrations were measured on each sample before and after recalcification with CaCl2 to determine if there was a significant difference in post - recalcification ionised calcium concentrations between the groups. Results: The results from the two groups were treated by Bland-Altman analysis. Apart from MCF values there was significant bias between all parameters measured in the two groups. The limits of agreement for all parameters apart from MCF were unacceptable. Conclusion: We found that ROTEM EXTEM® results from EDTA samples were not comparable to or interchangeable with those from citrated samples. The difference in results is not due to differences in ionised calcium concentration levels in the samples post-recalcification as the ionised calcium concentrations in both groups post-recalcification were adequate for coagulation. EDTA samples did show superior consistency in all parameters and may be a suitable alternative for sample preservation for VET if reference ranges can be established
Simulation of monolayer distribution for use in evaporation reduction
The use of monolayers to reduce evaporation was originally developed in 1925 (Frenkiel 1965). The major problem with using monolayers is the difficulty associated with the
prediction and control of the distribution of the monolayer to the water surface. Full scale experiments are not very successful due to difficulties quantitatively measuring the
evaporation resistance the monolayer provides to different areas of the water surface.
A simulation of the monolayer as it disperses and degrades on the water surface can be used to predict the long term performance as well as a real time control system. The
model was created in MATLAB and simulates the behaviour of the monolayer based on experimental results. The simulation selects the optimal application rate for each individual applicator based on maximising the amount of money saved by comparing the money gained from all possible permutations of applicator rates and applicator positions. The money saved has two parts, the cost associated with distributing the monolayer and the value of the water saved from evaporation. This comparison is performed for each small time step. After the optimal permutation of rates has been
found, the optimal permutation of rates for the following time step is calculate
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