The purpose of the study was to explore and understand how orphaned adolescents in grandparent-headed households achieve healthy functioning and how they rise above unfavourable circumstances. In exploring and gaining understanding, the research was approached from an interpertivist stance as it entails an inductive qualitative enquiry suitable to gaining a better understanding of the experiences and perceptions of orphaned adolescents. A qualitative methodological design was followed to ensure that the research questions could be answered. Purposive sample selection was used to select participants for this research study. The sample included nine adolescent orphans who reside in grandparent-headed households and are affiliated with Stanza Bopape Community Centre. Data collection included biographical questions, focus group interview and semi-structured interviews. Five of the nine participants took part in a focus group interview and the remaining four participated in individual semi-structured interviews. All interviews were conducted and transcribed by the researcher. Inductive thematic analyses was utilised to identify themes which emerged from the data. The themes which emerged were: the person I am, the supportive roles in parenting, role models in my life, things that are important to me, the future in me. These themes reflect the factors which contribute to the participants’ resilience and can be deduced as the mediating factors which assist them in achieving healthy functioning. The risks identified are aligned with residing in a township and attending a township school, however these risks were not experienced as demotivating adversities for the participants. They rather viewed them as motivating factors to achieve a better future. Bronfenbrenner’s bio-ecological theory served as the theoretical foundation for the study and it emerged that factors which contribute to the orphaned adolescents’ resilience (maintaining factors) come from various systems. Based on the findings of the study it can be concluded that orphaned adolescents residing in grandparent-headed households, although generally of low socio-economic status, are aware of their challenges and utilise certain processes to strengthen their resilience and overcome their challenges. / Dissertation (MEd)--University of Pretoria, 2018. / Educational Psychology / MEd / Unrestricted

This study is based on data from in-depth individual interviews carried out in a poor township, Ngangelizwe in Mthatha, South Africa. It discusses and describes the livelihoods and strategies of low–income households headed by elderly (>60years old) women. The study draws primarily on interviews with 15 elderly women who are receiving or not receiving State pension, selling goods or receiving or not receiving a Child Support Grant from the government for their grandchildren in order to meet the daily challenges they are faced with. It discusses the cultivation of social networks and how these networks in turn impact on the livelihoods, health, survival and social adjustment of the elderly women. This includes reports of these women’s perceptions of poverty, their incomes (the majority (thirteen) were receiving a State pension) as well as a professional pension. The study also reports on the strategies they used to try and avoid poverty through participation in income generating activities, having their grandchildren engaging in income-earning activities mostly after school or during holidays. The study underscores the reality of the adjustments and coping measures that the women have to adopt when faced with new challenges as a result of high morbidity and mortality among adults in the reproductive age groups. The findings of this study indicate that for most women, the inability to attain basic essentials of life leads to loss of self-dignity. Socio-economic factors such as low levels of education, unemployment, little or no income, poor access to resources, many dependants and looking after their children who suffer from HIV/AIDS among the women create a situation where they operate within the “little opportunities” circle. The evidence in this study suggests that social support groups, a pension grant, a child support grant and remittances from their children helped to mitigate some of the poverty experiences of the elderly women. The study also shows that there is a dire need for intensification of poverty reduction programmes at community levels. Women have to be supported with institutional credit to grow and expand their businesses. They need the support and assistance of government in taking care of their sick children and grandchildren due to HIV/AIDS. / Dissertation (MSocSci)--University of Pretoria, 2010. / Sociology / unrestricted

In the last half century, gun ownership has been one of the most hotly debated topics in the United States. The right to bear arms was written into the U. S. Constitution and into the hearts and minds of its citizens. During the last half century, however, numerous gun control laws have been enacted at Federal, state and local levels, and it can be argued (plausibly or not) that part of the legislative intent has been to decrease the number of gun owning households in the United States. For many decades, this number hovered at one half of all households (Wright, 1995). The possible success of these gun control efforts is suggested by an apparent and rather sharp decline in the ownership percentage beginning in the 1990s. In 2000, the household gun ownership rate had decreased to 32.5% (according to the General Social Survey). The question raised in this thesis is how to account for declining gun ownership. More specifically, I ask if there has in fact been a decline in ownership, or whether the apparent decline is an illusion resulting from changing demographics. A third possibility, that social norms have changed such that admitting gun ownership in surveys is now more problematic for many people, is also considered and seems, indeed, to be the most telling line of explanation.

Composite beams are frequently used in building, combining a steel beam with either a concrete-filled steel deck or solid concrete slab. To ensure proper composite action, shear connectors, typically in the form of headed shear studs, are utilized. Traditionally, the strength assessment of these headed shear studs is made using empirical design specifications that are based on push-out tests, which have been widely conducted and standardized over the years. However, the standardized push-out tests have short-comings, such as uneven slab bearing, slab buckling, questions regarding the distribution of load to each stud, etc. A study was conducted to evaluate and compare the existing push-out test setup with two alternative test setups. The study also aimed to examine the behavior of headed shear studs in composite beams having deck deeper the current allowable limit of 3 in., as specified by American Institute of Steel Construction (AISC) design specification. While the standard specification allows for steel decks with rib heights of up to 3 in., there are deck profiles deeper than 3 in. available in the market. Utilizing these deeper decks in composite beams offers several advantages, including faster and more cost-effective construction by reducing the number of beams required. This research therefore found that a major challenge in creating an alternative test setup involves eliminating moment at the interface between the concrete-filled steel deck and the steel beam. This moment leads to tension in the headed shear stud/stud group closest to the actuator, thus affecting the shear strength of the headed shear studs. Further, these headed shear studs have significant strength when used with 3.5 in. decks but further research is necessary. / Master of Science / Composite beams are widely used in building construction, combining a steel beam with either a concrete-filled steel deck or a solid concrete slab. To ensure their proper function, shear connectors are used, typically in the form of headed shear studs. Traditionally, the strength of these shear studs is determined using standardized push-out tests, but these tests some challenges like uneven slab bearing, questions about even load distribution, etc. In this study, the existing push-out test setup was evaluated and compared with two alternative setups. The behavior of headed shear studs in composite beams with deeper decks than the current allowable limit specified by design standards was also investigated. Using these deeper decks offers advantages such as faster and more cost-effective construction. One major challenge in creating an alternative test setup was eliminating the moment at the interface between the concrete-filled steel deck and the steel beam. This moment caused tension in the headed shear stud closest to the actuator, impacting the overall shear strength of the studs. Additionally, it was found that these shear studs show promising strength when used with 3.5 in. decks, but more research is needed to fully understand their capabilities. By exploring new test setups and considering deeper decks, this research contributes to improving the design and construction of composite beams, making them more efficient and reliable for future building projects.

No / This paper presents the experimental and numerical investigation into the behaviour of headed shear studs in composite beams with profiled metal deck flooring. A new single-sided horizontal push test arrangement is proposed to evaluate the shear capacity of the headed shear connectors in pairs with metal deck profiled sheeting. The characteristic resistance obtained from the horizontal push test is compared with Eurocode 4. A three-dimensional finite element model was developed using general purpose finite element program ABAQUS/Explicit. The shear connector capacity, load-slip behaviour and failure modes are validated against experimental results and close correlations were obtained.

Use of composite steel construction with precast hollow core slabs is now popular in the UK, but the present knowledge in shear capacity of the headed shear studs for this type of composite construction is very limited. Currently, all the information is based on the results obtained from experimental push-off tests. A finite element model to simulate the behaviour of headed stud shear connection in composite beam with precast hollow core slabs is described. The model is based on finite element method and takes into account the linear and non-linear behaviour of all the materials. The model has been validated against the test results, for which the accuracy of the model used is demonstrated. Parametric studies showing the effect of the change in transverse gap size, transverse reinforcement diameter and in-situ concrete strength on the shear connection capacity are presented.

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No description available.

In this project, we have designed and synthesized a new series of long-chain, water-soluble, dendritic, anionic amphiphiles [3CAmn, RCONHC(CH₂CH₂COOH)₃, R= CnH2n+1] to alleviate the low aqueous solubility of fatty acids. The dendritictricarboxlyato headgroup improves aqueous solubility and allows us to measure the intrinsic biological activity of our amphiphiles without the potential hindrance of low aqueous solubility. The aqueous solubilities of the anionic amphiphiles have been measured and were vastly higher than that of fatty acids. For example, 3CAm17 (1700 μM at pH 7.2) has much better aqueous solubility than the C₁₈ fatty acid analog (<<1 micromol at pH 7.4). Following the determination of aqueous solubility, both anionic and nonionic amphiphiles were tested against a wide variety of microorganisms. The anionic amphiphiles were mostly active against Candida albicans (4.4 microgram/mL), Saccharomyces cerevisiae (4.4 μg/mL), and Mycobacterium smegmatis (18 microgram/mL) and exhibited modest activity against both Gram-negative (71–280 microgram/mL) and Gram-positive bacteria (36– >6300 microgram/mL). With the exception of Neisseria gonorrhoeae (9.8 microgram/mL), the nonionic amphiphiles were mostly minimally active or inactive against Gram-negative bacteria (630–5000 microgram/mL). The nonionic amphiphiles were similarly inactive against fungi (625–5000 microgram/mL). However, the nonionic amphiphiles exhibited good activity against M. smegmatis (20 microgram/mL) and exhibited the best activity against Grampositive bacteria, such as MRSA (22 microgram/mL), Staphylococcus aureus (20 microgram/mL), and Micrococcus luteus (20 microgram/mL). The anionic and nonionic amphiphiles were also tested for possible spermicidal and anti-human immunodefiency virus (HIV) activity. The anionic amphiphiles exhibited anti-HIV activity (EC₅₀, 73–340 microgram/mL), but lacked spermicidal activity. The series had comparable anti-HIV activity to the commercial product N-9 (80 microgram/mL). Except 3CAm13, all anionic amphiphiles (1.4–4) had better selectivity indices than that of N-9 (0.9). The nonionic amphiphiles exhibited both anti-HIV (44–67 microgram/mL) and spermicidal activity (226–2000 microgram/mL). The nonionic amphiphile were more spermicidal and antiviral than Nonoxynol-9. In addition to biological activity, we determined whether the anionic amphiphiles could be utilized as corrosion inhibitors or ore flotation enhancers. The anionic amphiphiles formed stable thin films on silver oxide that were resistant to ethanol washings. We also measured the water contact angles of the anionic amphiphiles on mineral surfaces [apatite (95°), calcite (92°)]. / Ph. D.

Many previous studies of biological activity in a homologous series of amphiphiles have shown a cut-off effect, where the biological activity increases with an increase in chain length, after which the activity plateaus or weakens. One factor suspected to cause this problem is solubility issues. We have designed several series of very hydrophobic, water-soluble amphiphiles to overcome this problem. Three homologous series containing mobile hydrophobic moieties and two series of epimers containing rigid cholestane moieties have been synthesized; the hydrophobic moiety is connected to the first-generation, Newkome-type dendron via a ureido linker. We have demonstrated that as tris(triethanolammonium) salts, these amphiphiles show excellent solubility in water. The solubilities in aqueous triethanolamine solution of the three series containing mobile hydrophobic moieties are 19,500 to 25,700 μM depending on the formula weight of the homolog, while those containing rigid cholestane moieties are 18,900 and 17,400 μM. Having eliminated the solubility issue, the antimicrobial activity against a broad spectrum of microorganisms has been screened. We have demonstrated that the antimicrobial activity depends on the amphiphile-series, species, chain-length, or epimer specificities, as well as hydrophobicity. The one-tailed, tri-carboxylato amphiphiles are generally better than the other series, with two exceptions. First, the two-tailed tri-carboxylato amphiphiles, <b>3CUr1(11)₂</b> and <b>3CUr1(12)₂</b>, are more active against <i>Cryptococcus neoformans</i>; in fact, both amphiphiles (MICs are 6.9 and 7.2 μM, respectively) are considered to display good antifungal activity. Second, amphiphile <b>3CUr-β-cholestane</b>, whose MIC is 27 μM, is more active against <i>Staphylococcus aureus</i>. Overall, these new tri-carboxylato amphiphiles only exhibit moderate activity with two promising leads. Furthermore, we have demonstrated the intrinsic activity (MIC₀) of the one-tailed, tri-carboxylato amphiphile series (<b>3CUrn</b>) against <i>Mycobacterium smegmatis</i>. All the MIC₀s observed are at least 8-fold lower than the corresponding CMCs. Amphiphile <b>3CUr16</b> is the most active; the MIC₀ is 100-fold smaller than the CMC. With this consideration, we have suggested that the mechanism of action of the antimycobacterial activity in amphiphile <b>3CUr16</b> is not related to detergency. / Ph. D.