8 research outputs found
Quality of life and stigma in HIV-seropositive adolescents attending Mulago Hospital, Kampala, Uganda
No full textThe use of gasification ash in cement and concrete
No full textDissertation (MEng(Structural))--University of Pretoria, 2007.Cement is an essential material in today’s society because, as a major constituent of concrete, it forms a fundamental element of any housing or infrastructure development. The chemical process of making cement clinker produces CO2, a major greenhouse gas contributing to climate change. This makes it imperative for us to find ways of using this resource more efficiently. Using waste from other industries, as a raw material is a huge opportunity for the cement industry to reduce its environmental impact. Cement extenders are used as a substitute for some of the Portland cement in concrete. The reasons for the use of extenders, is a growing awareness of the engineering, economical and ecological benefits and the variety of useful enhancements, which they give to the concrete properties. The aim of the research is to determine whether a gasification ash can be used as a cement extender in concrete. In this study the properties of cement and concrete containing gasification ash was compared to the properties of cement and concrete containing fly ash. The physical, chemical and mineralogical composition of a gasification ash sample was investigated, and it was found that gasification ash has an angular shape and a similar chemical composition as fly ash. The chemical requirements of the gasification ash meet the majority of the requirements specified for cement extenders. Where limits are exceeded it is by a very narrow margin. The effect of a gasification ash on the short and long term properties of concrete of both interblending and intergrinding was investigated. The experimental work revealed that gasification ash improves the compressive and tensile strength of concrete in both interblending and intergrinding. Gasification ash does not have a detrimental effect on stiffness of concrete, and did not creep significantly more than concrete containing fly ash. The porosity and permeability does not increase when gasification ash is used as a cement extender. Gasification ash should therefore not decrease the durability of concrete. The use of gasification ash as a cement extender has advantages to both the cement industry and the environment.Civil Engineeringunrestricte
I support Open Access
No full textVideo prepared by the Department Education Innovation for the Open Scholarship Office, Department of Library Services, University of Pretoria as part of Open Access Week events 24-28 October 2011.Prof Brenda Wingfield, Professor in Genetics and Deputy-Dean of Reseach and Postgraduate Studies of the Faculty of Natural and Agricultural Sciences discusses the importance of access to research journals. As developing world countries have smaller budgets, Open Access has become increasingly important for research, as it provides greater visibility for researchers and also assists in keeping researchers up to date with information all the time. The University of Pretoria Senate approved a mandate promoting Open Access on campus and this is the wave of the future
Effect of grinding time on the particle size distribution of gasification ash and Portland cement clinker
No full textIn recent years the cement and concrete industry has reduced its environmental impact by increasing the use of waste materials as both cement extenders and fillers in concrete. Fly ash has been widely used as a cement extender in concrete for many years but the use of ash from other industries has been limited. In this study the use of ground coarse gasification ash as cement extender is investigated. The effect of grinding time on the particle size distribution (PSD) of gasification ash (GA) and Portland cement (PC) clinker was investigated. The PSD was determined for both blended GA and PC clinker that were first ground separately and interground GA and PC clinker. There appeared to be an optimum grinding time for the GA and interground of GA and PC clinker beyond which the fineness did not increase significantly. The particle size range was narrow after two hours' grinding and any increase in grinding time made it wider for GA and the blended cement. The fineness and Blaine specific surface area of GA and PC clinker increased with an increase in grinding time. However, this increase was less significant beyond two hours. The fineness had an effect on the rate of strength development of the blended cement. The compressive strength, particle size and Rosin-Rammler distribution parameters clearly indicated that grinding time should not be shorter than two hours for interblending and intergrinding of GA and PC clinke
Human capital and knowledge sharing in entrepreneurship: some empirical evidence
No full textAbstract not available
Inequalities in early marriage, childbearing and sexual debut among adolescents in sub-Saharan Africa
No full textAbstract Background Adolescent sexual and reproductive health (ASRH) is a major public health concern in sub-Saharan Africa (SSA). However, inequalities in ASRH have received less attention than many other public health priority areas, in part due to limited data. In this study, we examine inequalities in key ASRH indicators. Methods We analyzed national household surveys from 37 countries in SSA, conducted during 1990–2018, to examine trends and inequalities in adolescent behaviors related to early marriage, childbearing and sexual debut among adolescents using data from respondents 15–24 years. Survival analyses were conducted on each survey to obtain estimates for the ASRH indicators. Multilevel linear regression modelling was used to obtain estimates for 2000 and 2015 in four subregions of SSA for all indicators, disaggregated by sex, age, household wealth, urban–rural residence and educational status (primary or less versus secondary or higher education). Results In 2015, 28% of adolescent girls in SSA were married before age 18, declined at an average annual rate of 1.5% during 2000–2015, while 47% of girls gave birth before age 20, declining at 0.6% per year. Child marriage was rare for boys (2.5%). About 54% and 43% of girls and boys, respectively, had their sexual debut before 18. The declines were greater for the indicators of early adolescence (10–14 years). Large differences in marriage and childbearing were observed between adolescent girls from rural versus urban areas and the poorest versus richest households, with much greater inequalities observed in West and Central Africa where the prevalence was highest. The urban–rural and wealth-related inequalities remained stagnant or widened during 2000–2015, as the decline was relatively slower among rural and the poorest compared to urban and the richest girls. The prevalence of the ASRH indicators did not decline or increase in either education categories. Conclusion Early marriage, childbearing and sexual debut declined in SSA but the 2015 levels were still high, especially in Central and West Africa, and inequalities persisted or became larger. In particular, rural, less educated and poorest adolescent girls continued to face higher ASRH risks and vulnerabilities. Greater attention to disparities in ASRH is needed for better targeting of interventions and monitoring of progress
Learning from Ethiopia’s success in reducing maternal and neonatal mortality through a health systems lens
No full textBACKGROUND: This study aimed to enhance insights into the key characteristics of maternal and neonatal mortality declines in Ethiopia, conducted as part of a seven-country study on Maternal and Newborn Health (MNH) Exemplars. METHODS: We synthesised key indicators for 2000, 2010 and 2020 and contextualised those with typical country values in a global five-phase model for a maternal, stillbirth and neonatal mortality transition. We reviewed health system changes relevant to MNH over the period 2000-2020, focusing on governance, financing, workforce and infrastructure, and assessed trends in mortality, service coverage and systems by region. We analysed data from five national surveys, health facility assessments, global estimates and government databases and reports on health policies, infrastructure and workforce. RESULTS: Ethiopia progressed from the highest mortality phase to the third phase, accompanied by typical changes in terms of fertility decline and health system strengthening, especially health infrastructure and workforce. For health coverage and financing indicators, Ethiopia progressed but remained lower than typical in the transition model. Maternal and neonatal mortality declines and intervention coverage increases were greater after 2010 than during 2000-2010. Similar patterns were observed in most regions of Ethiopia, though regional gaps persisted for many indicators. Ethiopia's progress is characterised by a well-coordinated and government-led system prioritising first maternal and later neonatal health, resulting major increases in access to services by improving infrastructure and workforce from 2008, combined with widespread community actions to generate service demand. CONCLUSION: Ethiopia has achieved one of the fastest declines in mortality in sub-Saharan Africa, with major intervention coverage increases, especially from 2010. Starting from a weak health infrastructure and low coverage, Ethiopia's comprehensive approach provides valuable lessons for other low-income countries. Major increases towards universal coverage of interventions, including emergency care, are critical to further reduce mortality and advance the mortality transition
Women in health and their economic, equity and livelihood statuses during emergency preparedness and response (WHEELER) protocol: a mixed methods study in Kenya.
No full textIntroduction: Kenya reported its first COVID-19 case on 13 March 2020. Pandemic-driven health system changes followed and unforeseen societal, economic and health effects reported. This protocol aims to describe the methods used to identify the gender equality and health equity gaps and possible disproportional health and socioeconomic impacts experienced by paid and unpaid (community health volunteer) female healthcare providers in Kilifi and Mombasa Counties, Kenya during the COVID-19 pandemic. Methods and analysis: Participatory mixed methods framed by gender analysis and human-centred design will be used. Research implementation will follow four of the five phases of the human-centred design approach. Community research advisory groups and local advisory boards will be established to ensure integration and the sustainability of participatory research design. Ethics and dissemination: Ethical approval was obtained from the Institutional Scientific and Ethics Review Committee at the Aga Khan University and the University of Manitoba. This study will generate evidence on root cultural, structural, socioeconomic and political factors that perpetuate gender inequities and female disadvantage in the paid and unpaid health sectors. It will also identify evidence-based policy options for future safeguarding of the unpaid and paid female health workforce during emergency preparedness, response and recovery periods
