Evaluation of metal nitrides and borides as alternative electrocatalyst support materials for polymer electrolyte fuel cells

Includes bibliographical references.Polymer electrolyte fuel cells (PEFCs) have wide variety of commercial applications, however due to poor durability and high cost, this technology has currently not reached its commercialization stage. Poor durability is mainly attributed to carbon support corrosion during start-up and shut-down of the fuel cell. Corrosion of the electrocatalyst support materials has numerous adverse effects on the performance of the fuel cell, such as weakening of metal-support interaction which results in Pt detachment, dissolution and sintering. Hence, the electrochemical active surface area is significantly reduced. It is clear that there is an urgent need for more robust, high performance alternative support materials to carbon. In this study, metal nitrides and borides (TiN, ZrN, TiB₂ , ZrB₂ and LaB₆) were evaluated as potential support materials, in an attempt to improve the durability and performance of PEFCs

Letter Ruling 12-6: Sales/Use Tax on Publishing Software

BACKGROUND:Infection with, and treatment of HIV is associated with effects on glycaemia and renal function. The purpose of this study was therefore to compare glycaemic control and albuminuria in HIV-positive and HIV-negative type 2 diabetic patients. MATERIALS AND METHODS:Diabetic patients with and without HIV infection were recruited from a diabetic clinic at Chris Hani Baragwanath Hospital in Soweto, South Africa. Data was collected on weight, height, HbA1c, fasting glucose, urine albumin:creatinine ratio, HIV status, CD4 counts, viral load and concomitant therapies. Multivariable regression analysis was used to isolate the determinants of fasting glucose and HbA1c levels and risk factors for albuminuria. RESULTS:Data were collected from 106 HIV-positive and 214 HIV-negative diabetics. All HIV infected subjects were receiving anti-retroviral therapy. The determinants of fasting glucose levels (log) were HIV infection (β = 0.04, p = 0.01) and use of anti-hypertensive agents (β = 0.07, p = 0.0006), whilst for HbA1c levels (log) they were HIV infection (β = -0.03, p = 0.03), BMI (β = 0.004, p = 0.0005), statin use (β = 0.04, p = 0.002) and glucose levels (β = 0.01, p<0.0005). In HIV-positive subjects, CD4 counts were negatively associated with glucose levels (β = -0.0002, p = 0.03). The risk factors for albuminuria were (odds ratio [95% CIs]) dyslipidaemia (1.94 [1.09, 3.44], p = 0.02) and HbA1c levels (1.24 [1.12, 1.38], p<0.0001). DISCUSSION:These data suggest that glycaemic control is worse in type 2 diabetic subjects with HIV infection and that HbA1c underestimates glycaemia in these patients. Albuminuria was not associated with HIV-positivity. The negative relationship of CD4 counts with glucose levels may reflect viral removal and easing of the associated inflammatory response. It is possible that the association of statin and anti-hypertensive therapies with high HbA1c and glucose levels, respectively, is due to such therapies being given largely to subjects with poor glycaemic control

Adverse drug reactions reporting at a referral hospital in Zimbabwe

To establish factors influencing voluntary reporting of adverse drug reactions among health workers. A second objective was to establish the level of awareness on adverse drug reaction reporting and attitudes towards the voluntary adverse drug reaction reporting scheme. Design: Cross sectional descriptive study. Setting: Parirenyatwa Hospital, a major referral and teaching hospital in Harare, Zimbabwe. Subjects: 200 health professionals randomly selected from various departments. Main Outcome Measures: Number of health workers reporting adverse drug reactions; awareness of the adverse drug reaction reporting scheme

Communication and school readiness abilities of children with hearing impairment in South Africa: A retrospective review of early intervention preschool records

Background: The national prevalence of hearing impairment in South Africa is estimated to be four to six in every 1000 live births in the public health care sector. An undetected hearing impairment in childhood can lead to delayed speech and language development as well as put the child at risk of not achieving the necessary school readiness abilities that will enable them to achieve academic success. However, through early hearing detection and intervention services, children with hearing impairment can develop communication and school readiness abilities on par with children with normal hearing. Objective: The aim of the study was to describe communication and school readiness abilities of children who were identified with hearing impairment and enrolled in early intervention (EI) preschools in Gauteng. Methods: Within a descriptive research study design, a retrospective record review was conducted on files of eight children, ranging in age from 9 years and 7 months to 12 years and 7 months, identified with a hearing impairment and enrolled in EI preschools in Gauteng, South Africa. Descriptive statistics were used to analyse the data, using frequency distribution and measures of central tendency. Results: Current findings revealed that children with hearing impairment who were enrolled in EI preschools in Gauteng were identified late. This consequently led to delayed ages at initiation of EI services when compared to international benchmarks and the Health Professions Council of South Africa’s (HPCSA) guidelines of 2018. Consequently, participants presented with below average communication and school readiness abilities, which are characteristic of hearing impairment that is identified late. Conclusions: Transference of current contextually relevant research findings into practice by both the Department of Health and the Department of Basic Education forms part of future directions from this study. This conversion of research findings into service delivery must be conducted in a systematic manner at all levels in these two sectors to facilitate achievement of Early Hearing Detection and Intervention (EHDI), resulting in better communication and school readiness outcomes

Lithospheric structure of an Archean craton and adjacent mobile belt revealed from 2-D and 3-D inversion of magnetotelluric data : example from southern Congo craton in northern Namibia

Author Posting. © American Geophysical Union, 2013. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Solid Earth 118 (2013): 4378–4397, doi:10.1002/jgrb.50258.Archean cratons, and the stitching Proterozoic orogenic belts on their flanks, form an integral part of the Southern Africa tectonic landscape. Of these, virtually nothing is known of the position and thickness of the southern boundary of the composite Congo craton and the Neoproterozoic Pan-African orogenic belt due to thick sedimentary cover. We present the first lithospheric-scale geophysical study of that cryptic boundary and define its geometry at depth. Our results are derived from two-dimensional (2-D) and three-dimensional (3-D) inversion of magnetotelluric data acquired along four semiparallel profiles crossing the Kalahari craton across the Damara-Ghanzi-Chobe belts (DGC) and extending into the Congo craton. Two-dimensional and three-dimensional electrical resistivity models show significant lateral variation in the crust and upper mantle across strike from the younger DGC orogen to the older adjacent cratons. We find Damara belt lithosphere to be more conductive and significantly thinner than that of the adjacent Congo craton. The Congo craton is characterized by very thick (to depths of  250 km) and resistive (i.e., cold) lithosphere. Resistive upper crustal features are interpreted as caused by igneous intrusions emplaced during Pan-African magmatism. Graphite-bearing calcite marbles and sulfides are widespread in the Damara belt and account for the high crustal conductivity in the Central Zone. The resistivity models provide new constraints on the southern extent of the greater Congo craton and suggest that the current boundary drawn on geological maps needs revision and that the craton should be extended further south.The SAMTEX consortiummembers (Dublin Institute for Advanced Studies, Woods Hole Oceanographic Institution, Council for Geoscience (South Africa), De Beers Group Services, The University of the Witwatersrand, Geological Survey of Namibia, Geological Survey of Botswana, Rio Tinto Mining and Exploration, BHP Billiton, Council for Scientific and Industrial Research (South Africa), and ABB Sweden) are thanked for their funding and logistical support during the four phases of data acquisition. This work is also supported by research grants from the National Science Foundation (EAR-0309584 and EAR-0455242 through the Continental Dynamics Program to R. L. Evans), the Department of Science and Technology, South Africa, and Science Foundation of Ireland (grant 05/RFP/ GEO001to A. G. Jones).2014-02-0

Preventive audiology

This book is an original scholarly book that introduces the concept of preventive audiology, with a specific focus on the African context, which is in line with the South African re-engineered primary healthcare strategy as well as the World Health Organisation’s approach. The book reflects on contextually relevant and responsive evidence-based perspectives, grounded in an African context on preventive audiology, in four major ear and hearing burdens of disease within the South African context: (1) early hearing detection and intervention, (2) middle ear pathologies, (3) ototoxicity, and (4) noise-induced hearing loss. The book represents innovative research, seen from both a South African and global perspective. It offers new discourse and argues for a paradigm shift in how audiology is theorised and performed, particularly in low-and-middle-income country contexts. The goal of this book is to motivate a paradigm shift in how the ear and hearing care is approached within this low-and-middle-income country context while arguing for Afrocentric best practice evidence that leads to next practice

Preventive audiology

This book is an original scholarly book that introduces the concept of preventive audiology, with a specific focus on the African context, which is in line with the South African re-engineered primary healthcare strategy as well as the World Health Organisation’s approach. The book reflects on contextually relevant and responsive evidence-based perspectives, grounded in an African context on preventive audiology, in four major ear and hearing burdens of disease within the South African context: (1) early hearing detection and intervention, (2) middle ear pathologies, (3) ototoxicity, and (4) noise-induced hearing loss. The book represents innovative research, seen from both a South African and global perspective. It offers new discourse and argues for a paradigm shift in how audiology is theorised and performed, particularly in low-and-middle-income country contexts. The goal of this book is to motivate a paradigm shift in how the ear and hearing care is approached within this low-and-middle-income country context while arguing for Afrocentric best practice evidence that leads to next practice

Livelihood and vulnerability in the wake of Typhoon Yolanda: lessons of community and resilience

Livelihood strategies that are crafted in ‘extra-ordinary’ post-disaster conditions should also be able to function once some semblance of normalcy has resumed. This article aims to show that the vulnerability experienced in relation to Typhoon Yolanda was, and continues to be, directly linked to inadequate livelihood assets and opportunities. We examine the extent to which various livelihood strategies lessened vulnerability post-Typhoon Yolanda and argue that creating conditions under which disaster survivors have the freedom to pursue sustainable livelihood is essential in order to foster resilience and reduce vulnerability against future disasters. We offer suggestions to improve future relief efforts, including suggestions made by the survivors themselves. We caution against rehabilitation strategies that knowingly or unknowingly, resurrect pre-disaster vulnerability. Strategies that foster dependency, fail to appreciate local political or ecological conditions or undermine cooperation and cohesion in already vulnerable communities will be bound to fail. Some of the livelihood strategies that we observed post-Typhoon Yolanda failed on some or all of these points. It is important for future policy that these failings are addressed

The African intellectuals’ project

Soon after taking the position of editor of IJARS at the beginning of 2019, I was contacted by the dean of Unisa’s College of Graduate Studies (CGS), Prof. Lindiwe Zungu, who informed me that the university’s principal and vice-chancellor, Prof. Mandla Makhanya, had decided to revive his project, the African Intellectuals’ Project (AIP). I was asked to coordinate this project, through which Makhanya sought to invite scholars, academics, and intellectuals, both on and outside of the African continent, to deliver presentations reflecting on the ills afflicting Africa and, at the same time, to offer possible solutions. In pursuing the AIP, Prof. Makhanya was carrying on a perennial tradition

Addiction in the Light of African Values: Undermining Vitality and Community

In this article I address the question of what makes addiction morally problematic, and seek to answer it by drawing on values salient in the sub-Saharan African philosophical tradition. Specifically, I appeal to life-force and communal relationship, each of which African philosophers have at times advanced as a foundational value, and spell out how addiction, or at least salient instances of it, could be viewed as unethical for flouting them. I do not seek to defend either vitality or community as the best explanation of when and why addiction is immoral, instead arguing that each of these characteristically African values grounds an independent and plausible account of that. I conclude that both vitalism and communalism merit consideration as rivals to accounts that Western ethicists would typically make, according to which addiction is immoral insofar as it degrades rationality or autonomy, as per Kantianism, or causes pain or dissatisfaction, à la utilitarianism