Two terminal current limiter

Two terminal device protects dc electronic circuits and experimental solid state devices, and replaces fuses and circuit breakers directly. The device consists of two transistors and two resistors and draws its necessary supply voltage from power source being protected. The limiter acts as a voltage regulator

Improved technique for inspection of planar surfaces by microscopy and interferometry

Incident white light and ordinary interferometer attachment provide images that differ in color according to relative heights of planar surfaces. With aid of technique, it is possible to perceive buried layers, such as diffused collectors, as well as discover defects in buried layers

Effects of increasing cold exposure on the oxygen uptake of walking unloaded and loaded.

Introduction: Cold exposure and load carriage is an understudied area. Most research shows that VO2max is generally unaffected by cold exposure, however the majority of research suggests that sub-maximal O2 consumption increases for a given workload [1]. This pilot study assessed the effects of cold on load carriage. Methods: 4 male participants (age: 21.8 ± 3.4 years, height: 182.5 ±5.0 cm, weight: 77.8 ± 13.5 kg) completed a walking protocol of ~1 hour in a range of different ambient temperatures within an environmental chamber (20 °C, 10 °C, 5 °C, 0 °C, -5 °C and -10 °C). Humidity was controlled at ~50% while altitude was 0 m (20.95% FiO2). Participants wore shorts and t-shirt for all trials. The protocol included a 15 minute rest period, unloaded walking at 4 km.hr-1 for 4 minutes at 0% and 10% gradient. The same workloads were repeated loaded (18 kg) after a 5 minute rest. Heart rate returned to resting levels before each exercise section to ensure prior activity did not influence findings. Unloaded walking was then repeated. Expired air was collected and analysed using a Cortex 3B Metalyzer (Germany). Statistical analysis was performed using SPSS version 22, with significance denoted by p < 0.05. Results: Table ​Table1 shows a significant increase in VO2 with load (p = 0.019). At all workloads, significant increases in VO2 were associated with decreasing temperature (p = 0.048). ΔVO2 values suggest that the effect of loading was consistent, regardless of ambient temperature (p = 0.997). When comparing the first unloaded exercise bout with the second, VO2 for 20 °C, 10 °C and 5 °C was similar, whereas at 0 °C and below, VO2 was higher in the second unloaded bout, but this interaction was not significant (p = 0.158)

Making memory work: Performing and inscribing HIV/AIDS in post-apartheid South Africa

This thesis argues that the cultural practices and productions associated with HIV/AIDS represent a major resource in the struggle to understand and combat the epidemic. Research into HIV/AIDS is dominated by biomedical scholarship, and yet in South Africa, the main drivers of the epidemic are social and economic. The cultural productions analysed in this thesis confront and illuminate many of the contradictory and unresolved questions facing HIV/AIDS research today. The primary materials analysed in this thesis are the cultural texts that explore representations and performances of HIV/AIDS in South Africa from 1995-2012. I locate experiences of HIV/AIDS in a range of theatrical, literary and visual artworks, including prose, drama and memoir, as well as film and critical work across an array of genres. More than simply surveying HIV/AIDS cultural artefacts, I offer socially and historically contextualised accounts of how stories from post-apartheid writers, performers, artists and subjects engage with HIV/AIDS within a climate hostile to their existence. In my analysis of the texts considered, I develop an argument that underlines the interventionist capacities of cultural production around HIV/AIDS. I investigate to what degree these texts aim to change consciousness and challenge the social behaviours that contribute to HIV prevalence. I argue that the most significant responses to HIV/AIDS in the last thirty years have been grassroots cultural practices that empower those who otherwise have had little agency in dictating their own circumstances and histories of the epidemic. These findings lead me to argue for a paradigm shift in HIV/AIDS research: from the widespread application of medical hegemony to the consideration of community-level cultural interventions in addressing the epidemic

Digitising and archiving HIV and AIDS in South Africa: The Museum of AIDS in Africa as an archival intervention

The AIDS epidemic in South Africa has demanded interventions from a number of different forums. Drawing on theory relating to the archive in post-apartheid South Africa and data from the online archive from the Museum of AIDS in Africa (MAA), this article explores the possibilities and challenges of using digital technologies alongside physical artefacts to intervene in the AIDS epidemic in South Africa by creating a postcolonial AIDS archive. Focusing in particular on the case of the MAA, in this article I examine the ability of the MAA to act as an archival intervention into the epidemic in two ways. The first of these is through the development of physical and digital archives that prioritise diversity and accessibility in order to reach marginalised constituencies. The second is by breaking the silence about those made most marginalised and vulnerable by HIV and AIDS through giving them the opportunity to contribute to the Museum’s digital content

Pathways to parenting stress reduction among parents in South Africa

Parenting stress has a range of effects on parents and their children. Despite existing evidence on the effectiveness of family-based interventions on reducing parenting stress, little is known about the mechanism of change that contributes to its reduction. This study investigates the mechanism of change in a parenting programme (Parenting for Lifelong Health [PLH]) on reducing parenting stress among parents of adolescents in South Africa. A pragmatic cluster randomized controlled trial was conducted among a total sample of 552 parents and primary caregivers (aged, M = 49.37; SD = 14.69) who were recruited from 40 communities in South Africa's Eastern Cape Province. A mediation analysis was performed to investigate direct and indirect effects using PROCESS macrostatistical software. The findings of the study indicate that parenting stress reduction operates via three significant mediators: improved parent–child relationship (β = 0.058, P β = −0.103, P β = −0.049, P

Digitising and archiving HIV and AIDS in South Africa: The Museum of AIDS in Africa as an archival intervention

The AIDS epidemic in South Africa has demanded interventions from a number of different forums. Drawing on theory relating to the archive in post-apartheid South Africa and data from the online archive from the Museum of AIDS in Africa (MAA), this article explores the possibilities and challenges of using digital technologies alongside physical artefacts to intervene in the AIDS epidemic in South Africa by creating a postcolonial AIDS archive. Focusing in particular on the case of the MAA, in this article I examine the ability of the MAA to act as an archival intervention into the epidemic in two ways. The first of these is through the development of physical and digital archives that prioritise diversity and accessibility in order to reach marginalised constituencies. The second is by breaking the silence about those made most marginalised and vulnerable by HIV and AIDS through giving them the opportunity to contribute to the Museum’s digital content

Opening the black box:A mixed-methods investigation of social and psychological mechanisms underlying changes in financial behaviour

We use a mixed-methods approach to open the ‘black box’ of a combined financial literacy and parenting intervention (‘Parenting for Lifelong Health’) to elucidate the key mechanisms through which changes in financial behaviour are realised. Drawing on qualitative data from 16 focus groups and 42 in-depth interviews, we find evidence for three pathways of change. Higher financial skills and, linked to this, higher financial confidence, a more optimistic future outlook and emotional support provided by peers and family members are described as key facilitators of improved financial behaviour. These mechanisms are cross validated in subsequent quantitative analyses based on standardised interviews from a randomised controlled trial with 552 households. A mediation analysis indicates that the programme’s effect on financial behaviour is significantly mediated by financial skills and self-efficacy (24% of total effect) and optimism (22% of total effect). We further show that the psychological factors are significantly reinforced by increased levels of social support in the family and wider community. Mediating variables remain robust in sensitivity analyses and are confirmed as significant paths when entered simultaneously into a structural equation path model. Our findings highlight possible target points for financial literacy interventions and motivate the inclusion of psychosocial programme components

The effect of temperature, gradient and load carriage on oxygen consumption, posture and gait characteristics

Purpose The purpose of this experiment was to evaluate the effect of load carriage in a range of temperatures to establish the interaction between cold exposure, the magnitude of change from unloaded to loaded walking and gradient. Methods Eleven participants (19-27 years) provided written informed consent before performing six randomly ordered walking trials in six temperatures (20°C, 10°C, 5°C, 0°C, -5°C and -10°C). Trials involved two unloaded walking bouts before and after loaded walking (18.2 kg) at 4 km.hr⁻¹, on 0% and 10% gradients in 4 minute bouts. Results The change in absolute oxygen consumption (V̇O₂) from the first unloaded bout to loaded walking was similar across all six temperatures. When repeating the second unloaded bout, V̇O₂ at both -5°C and-10°C was greater compared to the first. At -10°C, V̇O₂ was increased from 1.60 ± 0.30 L.min⁻¹ to 1.89 ± 0.51 L.min⁻¹. Regardless of temperature, gradient had a greater effect on V̇O₂ and heart rate (HR) than backpack load. HR was unaffected by temperature. Stride length (SL) decreased with decreasing temperature but trunk forward lean was greater during cold exposure. Conclusion Decreased ambient temperature did not influence the magnitude of change in V̇O₂ from unloaded to loaded walking. However, in cold temperatures, V̇O₂ was significantly higher than in warm conditions. The increased V̇O₂ in colder temperatures at the same exercise intensity is predicted to ultimately lead to earlier onset of fatigue and cessation of exercise. These results highlight the need to consider both appropriate clothing and fitness during cold exposure

Household economic strengthening through financial and psychosocial programming: evidence from a field experiment in South Africa

Using data from a randomized field experiment with 552 households, nested within 40 villages and townships in South Africa, we examine the impact of a brief financial literacy training that was integrated into a broader psychosocial parenting intervention. Based on self-reported measures, we document significant improvements in financial behaviors, including higher saving and lower borrowing rates. We also see wider implications for household economic welfare, demonstrated by reduced self-reported financial distress, better resilience to economic shocks, and a greater capacity to securing basic needs. We argue that program impact may run through three effect channels, namely improved self-efficacy, higher family and community social support, and greater optimism. Overall, our findings suggest that “hybrid” program curricula that offer combinations of financial and psychosocial components can add value to stand-alone financial literacy training