Bioceramic hydroxyapatite coating fabricated on TI-6AL-4V using Nd:YAG laser

A method of synthesising a biocompatible HAP coating is presented. In the current study, Nd:YAG laser was used to directly melt pre-place HAP powder beds on Ti-6Al-4V. The processing parameters used were 750 W laser power, 5 mm/s scanning speed and 27° inclined beam plane. The coating was studied under white light and scanning electron microscope where it was possible to characterise the microstructures. The produced coating was characterised of mixed morphologies of HAP, short and elongated titanium needles at the surface while in the middle of the coating dendrite trunks without arms were observed. This observation is related to the heat inputs, dilution and melting of the substrate and powder during processing. The absence of the arms growing from the trunks indicated low heat inputs. In addition, the microstructure of the HAP after soaking in Hanks’ solution indicated octagonal and hexagonal crystals of HAP. The hardness values indicated good metallurgical bonding at the interface. In conclusion, this study was successful in fabricating a desirable coating of HAP on Ti-6Al-4V for biomedical applications. This work highlights that even though laser power and scanning speed are predominantly influential parameter settings, it is also necessary to consider the angle at which the laser beam is scanned across the material

Iot-enabled supply chain management and logistics

Papers presented virtually at the 41st International Southern African Transport Conference on 10-13 July 2050Supply Chain Management (SCM) has evolved over the years, from mechanisation in the 1920s to intelligentisation in the 2000s. Major changes in supply chain are due to challenges in the environment, such as the fragmentation of SCM activities and the introduction of the Internet of Things (IoT). The lack of visibility of assets and transportation management issues in SCM led to research being conducted to alleviate these challenges. In the South African context, the quality and competence of logistics operations, tracking and tracing of assets and management of activities are the main challenges identified in SCM, even though there are numerous companies involved in tracking assets. Effective management of supply chain activities requires the integration of technology into the SCM and logistics value chain. The supply chain value chain includes inbound logistics, outbound logistics, operations, sales, marketing, and supply services. Automating warehouse operations can help to address some of the challenges in SCM. This research paper addresses how the Smart Warehousing Management System (SWMS) and the Fleet Management System (FMS) developed aim to resolve asset tracking and tracing and improving logistics operations. Using the Internet of Things (IoT) in integrating sensors to track assets and improve warehouse operations can reduce SCM challenges. The FMS aims to resolve transportation management issues by tracking and tracing assets in logistics operations, while the SWMS automates warehouse operations, thus, improving SCM activities

PROPOSED GUIDELINES TO MINIMISE MULTI-DRUG RESISTANT TUBERCULOSIS TREATMENT DEFAULT IN A MULTI-DRUG RESISTANT UNIT OF LIMPOPO PROVINCE, SOUTH AFRICA

Background: The increasing prevalence and incidence of Multi Drug Resistant Tuberculosis (MDR-TB) is as a result of the defaulting of treatment by patients. Worldwide, several factors that contribute to patients defaulting to tuberculosis treatment protocol have been identified. This paper aims to develop guidelines to minimise the defaulting rate of MDR-TB patients in MDR unit of Limpopo Province. Materials and Methods: The study was conducted using a qualitative approach. Tesch’s open coding method of data analysis was adopted to analyse the data obtained. Reasoning strategies were employed in the development of the guidelines. These include analysis, synthesis, deductive reasoning and inductive reasoning. Synthesis strategy was used to construct relational statements. Results: The factors contributing to patients’ default from MDR-TB treatment were identified and organized into four themes. Guidelines were developed to address each factor and give recommendations on possible solutions. Conclusion: The guidelines that were developed concluded that co-operation amongst the Department of Health, health practitioners, patient, and family members can help in preventing the defaulting of treatment

Thermodynamically accessible titanium clusters TiN, N = 2-32

We have performed a genetic algorithm search on the tight-binding interatomic potential energy surface (PES) for small TiN (N = 2-32) clusters. The low energy candidate clusters were further refined using density functional theory (DFT) calculations with the PBEsol exchange-correlation functional and evaluated with the PBEsol0 hybrid functional. The resulting clusters were analysed in terms of their structural features, growth mechanism and surface area. The results suggest a growth mechanism that is based on forming coordination centres by interpenetrating icosahedra, icositetrahedra and Frank-Kasper polyhedra. We identify centres of coordination, which act as centres of bulk nucleation in medium sized clusters and determine the morphological features of the cluster

Thermodynamically accessible titanium clusters TiN, N = 2–32

We have performed a genetic algorithm search on the tight-binding interatomic potential energy surface (PES) for small TiN (N = 2–32) clusters. The low energy candidate clusters were further refined using density functional theory (DFT) calculations with the PBEsol exchange–correlation functional and evaluated with the PBEsol0 hybrid functional. The resulting clusters were analysed in terms of their structural features, growth mechanism and surface area. The results suggest a growth mechanism that is based on forming coordination centres by interpenetrating icosahedra, icositetrahedra and Frank–Kasper polyhedra. We identify centres of coordination, which act as centres of bulk nucleation in medium sized clusters and determine the morphological features of the cluster

COVID‑19 in pregnant women in South Africa: A retrospective review

Background. The majority of maternal deaths in South Africa (SA) occur as a result of non-pregnancy-related infections (NPRI). Pregnancy is a known risk factor in severe COVID‑19, increasing the burden of NPRI in SA. In this study, we describe the prevalence, profile and clinical outcomes of pregnant women with COVID‑19 admitted to a tertiary facility. Objectives. To describe the prevalence, profile and clinical outcomes of pregnant women with COVID‑19 admitted to a tertiary facility in Gauteng, SA. Methods. We performed a retrospective review of all pregnant women with COVID‑19 admitted to Charlotte Maxeke Johannesburg Academic Hospital between 6 March and 30 August 2020. Data collected included demographics, medical history, obstetric history, clinical findings and laboratory variables. Outcomes assessed were mortality, admission to intensive care unit (ICU), symptomatic v. asymptomatic disease, maternal and fetal outcome and mode of delivery. Results. A total of 204 pregnant women were included in the study. Of these, 33 (16.2%) women were critically ill, with 21 (10.3%) admitted to the ICU and 3 (1.5%) deaths related to COVID‑19. The median gestational age was 37 weeks and median birthweight 2 940 g. Sixty-seven women (33%) were HIV-positive, in keeping with national statistics regarding HIV in pregnancy. Caesarean section was the most common mode of delivery (n=105, 60%). However, no women underwent caesarean section for indications related to COVID‑19. Conclusion. COVID‑19-related mortality in our cohort was higher than that seen internationally, likely due to differences in background maternal mortality rates and difficulty in accessing care

Thermodynamically accessible titanium clusters Ti_N, N = 2–32

We have performed a genetic algorithm search on the tight-binding interatomic potential energy surface (PES) for small TiN (N = 2–32) clusters. The low energy candidate clusters were further refined using density functional theory (DFT) calculations with the PBEsol exchange–correlation functional and evaluated with the PBEsol0 hybrid functional. The resulting clusters were analysed in terms of their structural features, growth mechanism and surface area. The results suggest a growth mechanism that is based on forming coordination centres by interpenetrating icosahedra, icositetrahedra and Frank–Kasper polyhedra. We identify centres of coordination, which act as centres of bulk nucleation in medium sized clusters and determine the morphological features of the cluster

Independent and combined effects of improved water, sanitation, and hygiene, and improved complementary feeding, on child stunting and anaemia in rural Zimbabwe: a cluster-randomised trial.

BACKGROUND: Child stunting reduces survival and impairs neurodevelopment. We tested the independent and combined effects of improved water, sanitation, and hygiene (WASH), and improved infant and young child feeding (IYCF) on stunting and anaemia in in Zimbabwe. METHODS: We did a cluster-randomised, community-based, 2 × 2 factorial trial in two rural districts in Zimbabwe. Clusters were defined as the catchment area of between one and four village health workers employed by the Zimbabwe Ministry of Health and Child Care. Women were eligible for inclusion if they permanently lived in clusters and were confirmed pregnant. Clusters were randomly assigned (1:1:1:1) to standard of care (52 clusters), IYCF (20 g of a small-quantity lipid-based nutrient supplement per day from age 6 to 18 months plus complementary feeding counselling; 53 clusters), WASH (construction of a ventilated improved pit latrine, provision of two handwashing stations, liquid soap, chlorine, and play space plus hygiene counselling; 53 clusters), or IYCF plus WASH (53 clusters). A constrained randomisation technique was used to achieve balance across the groups for 14 variables related to geography, demography, water access, and community-level sanitation coverage. Masking of participants and fieldworkers was not possible. The primary outcomes were infant length-for-age Z score and haemoglobin concentrations at 18 months of age among children born to mothers who were HIV negative during pregnancy. These outcomes were analysed in the intention-to-treat population. We estimated the effects of the interventions by comparing the two IYCF groups with the two non-IYCF groups and the two WASH groups with the two non-WASH groups, except for outcomes that had an important statistical interaction between the interventions. This trial is registered with ClinicalTrials.gov, number NCT01824940. FINDINGS: Between Nov 22, 2012, and March 27, 2015, 5280 pregnant women were enrolled from 211 clusters. 3686 children born to HIV-negative mothers were assessed at age 18 months (884 in the standard of care group from 52 clusters, 893 in the IYCF group from 53 clusters, 918 in the WASH group from 53 clusters, and 991 in the IYCF plus WASH group from 51 clusters). In the IYCF intervention groups, the mean length-for-age Z score was 0·16 (95% CI 0·08-0·23) higher and the mean haemoglobin concentration was 2·03 g/L (1·28-2·79) higher than those in the non-IYCF intervention groups. The IYCF intervention reduced the number of stunted children from 620 (35%) of 1792 to 514 (27%) of 1879, and the number of children with anaemia from 245 (13·9%) of 1759 to 193 (10·5%) of 1845. The WASH intervention had no effect on either primary outcome. Neither intervention reduced the prevalence of diarrhoea at 12 or 18 months. No trial-related serious adverse events, and only three trial-related adverse events, were reported. INTERPRETATION: Household-level elementary WASH interventions implemented in rural areas in low-income countries are unlikely to reduce stunting or anaemia and might not reduce diarrhoea. Implementation of these WASH interventions in combination with IYCF interventions is unlikely to reduce stunting or anaemia more than implementation of IYCF alone. FUNDING: Bill & Melinda Gates Foundation, UK Department for International Development, Wellcome Trust, Swiss Development Cooperation, UNICEF, and US National Institutes of Health.The SHINE trial is funded by the Bill & Melinda Gates Foundation (OPP1021542 and OPP113707); UK Department for International Development; Wellcome Trust, UK (093768/Z/10/Z, 108065/Z/15/Z and 203905/Z/16/Z); Swiss Agency for Development and Cooperation; US National Institutes of Health (2R01HD060338-06); and UNICEF (PCA-2017-0002)

Infrastructure Development and Economic Complexity in South Africa Running Title: Can Infrastructure Development Influence Economic Complexity?

South African economy comprises of a narrow range of exports and an over-dependence on the primary production. These challenges hindered the growth and development of the country as well as the continent. One of the ways to enhance growth and development is through the improvement of economic complexity which measures productive capabilities of sophisticated products that countries export. The study seeks to find the role of investing in infrastructure development has on economic complexity using South African data. The autoregressive distributive lag approach was employed using yearly data spanning from 1960 to 2018. Results indicate that investing in government economic infrastructure has a negative and robust impact on economic complexity. Investment on government social infrastructure and public corporations' infrastructure can positively influence economic complexity. It can be recommended that there should be policies to support industrial development that targeted incentivising economic infrastructure development. The development should prioritize specific geographical areas such as special economic zones to improve the lives of citizens, boost the economy, attract foreign direct investment and create jobs