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

Comparative behavior of conjugates of tantalum phthalocyanines with gold nanoparticles or single walled carbon nanotubes towards bisphenol A electrocatalysis

The characterization of tantalum phthalocyanine conjugates with gold nanoparticles and single wall carbon nanotubes as well as their electrocatalytic oxidation of bisphenol A is hereby presented. The formation of the conjugates was confirmed by X-ray diffraction and transmission electron microscope techniques. Single walled carbon nanotube conjugates of TaPc complexes showed the best catalysis as well as less passivation for bisphenol A detection and significant recovery of ∼98% compared to gold nanoparticle conjugates

The Thermal Agitated Phase Transitions on the Ti32 Nanocluster: a Molecular Dynamics Simulation Study

Molecular dynamics simulations were performed to investigate the stability with respect to increasing the simulated temperature from 300 to 2400 K of an isolated cluster composed of 32 titanium atoms. The interatomic interactions were modelled using Gupta potentials as implemented within the classical molecular dynamics simulation software DL_POLY. The radial distribution functions (RDF), diffusion coefficient, and density profiles were examined to study the structural changes as a function of temperature. It was found that the Ti32 nanocluster exhibits temperature structural transition. The icosahedron and pentagonal bi-pyramid structures were found to be the most dominant building block fragments. Deformation of the nanocluster was also measured by diffusion coefficient, and it was found that the Ti32 are mobile above the bulk melting point. The phase transitions from solid to liquid have been identified by a simple jump in the total energy curve, with the predicted melting temperature near the bulk melting point (1941.15 K). As expected, the RDF’s and density profile peaks decrease with increasing temperature

Women’s perspectives on the measures that need to be taken to increase the use of health-care facility delivery service among slums women, Addis Ababa, Ethiopia: a qualitative study

Abstract Background Global strategies to target high maternal mortality ratios are focused on providing skilled attendance at delivery along with access to emergency obstetric care. Research that examines strategies to increase facility-based skilled birth attendance among slum residents in Addis Ababa, Ethiopia, is limited. Objective The study aimed to explore women's perspectives on the measures that need to be taken to increase the use of the facility—delivery service among slums women, Addis Ababa, Ethiopia Methods Qualitative exploratory and descriptive research designs were used. Participants in the study were women in the reproductive age group (18–49 years of age) living in the slum areas of Addis Ababa, Ethiopia. A purposive sampling strategy was used to select study participants. Potential participants' names were gathered from health facilities and followed to their homes for the study. Four audio-recorded focus group discussions [FGDs] were conducted with 32 participants from the three public health centers and one district hospital. The number of participants in FGDs was between 6 and 10 women. Data were analyzed simultaneously with data collection. Thematic analysis was used in data analysis, which entails three interconnected stages: data reduction, data display, and data conclusion. In addition, thematic analysis entailed evaluating the structure and content of textual data, identifying data themes, coding the themes, and then interpreting the structure and content of the themes. A codebook was first devised, discussed, and adopted by the writers before they could use this technique. Using the codebook, the theme codes were then manually produced. To explain the study results, verbatim excerpts from participants were given. The researcher used Techs' eight steps of qualitative data analysis method for analyzing the data. A multi-level life-course framework of facility-based delivery in low- and middle-income countries (LMICs) developed by Bohren et al. was used to frame the current study and link the findings of the study to the body of knowledge. Results The FGDs included a total of 32 participants. The mean age of the overall sample was 32.6 years (± SD = 5.2). Participants' educational characteristics indicate that the majority (24 out of 32) was found to have no formal education, and two-thirds of participants were found to have one to five children. Three-fourths of them attended the ANC twice and they all gave birth to their last child at home. Two themes emerged from the analysis of focus group data, namely provision of quality, respectful and dignified midwifery care, and lack of awareness about facility delivery. These themes were described as a rich and comprehensive account of the views and suggestions made by focused antenatal care [FANC] participants on measures required to improve the use of the facility-delivery services. The findings of the study raise concerns about the effectiveness of FANC in encouraging facility-deliveries since FANC participants had not used health facilities for their last childbirth. According to the findings of the focus groups, women who took part in this study identified measures required to increase the use of health facility-delivery services among FANC participants in Addis Ababa's slum residents. It is to be expected that diligent counseling during antenatal care about birth plans would facilitate prompt arrival at facilities consistent with the desires of women.Plain language summary Global strategies for targeting high maternal mortality levels are based on ensuring eligible delivery attendance along with access to obstetric emergency care. Research examining strategies to increase facility-based skilled birth attendance among slum residents in Addis Ababa, Ethiopia, is minimal. The study aimed to examine women's perspectives on measures needed to improve the use of health facility-based delivery services. A qualitative research design, both exploratory and descriptive, was used. Women in the reproductive age group (18–49 years of age) living in the slum areas of Addis Ababa, Ethiopia, participated in the study. The study used a purposeful sampling method. Four audio-recorded focus group discussions [FGDs] were conducted with 32 participants. In FGDs, the number of participants was between 6 and 10 women. Data were analyzed in conjunction with data collection. For the research, thematic analysis was performed. Two issues arose from the review of data from focus group interviews, namely quality care provision, respectful and dignified midwifery care, and lack of awareness about facility delivery. These themes were identified as a detailed and comprehensive account of the views and suggestions of focused antenatal care [FANC] participants on steps needed to enhance the use of health facility-based delivery services. According to the results of the focus groups, among FANC participants in the slum residents of Addis Ababa, women who took part in this study identified steps needed to increase the use of health facility-based delivery services. It is to be expected that diligent counseling during antenatal care about birth plans would facilitate prompt arrival at facilities consistent with the desires of women

Collaborative custodianship through collaborative cloud mapping : challenges and opportunities

Collaborative custodianship refers to an arrangement where a number of custodians work together to produce integrated datasets for a spatial data infrastructure (SDI), e.g. local authorities contributing address or street data to a national SDI dataset. Collaborative cloud mapping allows for ubiquitous, convenient, on-demand, configured and tailor-made mapping with resources shared between various entities collaborating on a specific initiative, such as an SDI or for disaster management. This paper presents the results of a workshop in South Africa during which case studies from the Netherlands, Belgium and Austria of collaborative custodianship of address data were presented, and OpenStreetMap as a case study of collaborative cloud mapping. Subsequently, challenges and opportunities for implementing similar initiatives in the context of the South African SDI were debated in break-away sessions. The results from these sessions were analysed using the PESTEL framework

Third order nonlinear optical properties of phthalocyanines in the presence nanomaterials and in polymer thin films

Third order nonlinear optical properties were determined for phthalocyanine complexes 1–10 containing In, Ga and Zn central metals and tetra- or octa-substituted with benzyloxyphenoxy, phenoxy, tert-butylphenoxy and amino groups at peripheral or non-peripheral positions. The phthalocyanines were embedded in poly (methyl methacrylate) polymer in the presence of CdTe quantum dots. All complexes 1–10 were studied in the presence of CdTe quantum dots and embedded in poly (methyl methacrylate) to form thin films. Complex 3 tetrasubstituted with tert-butylphenoxy groups at non-peripheral positions was also studied in the presence of CdS, CdSe quantum dots, fullerenes, single walled carbon nanotubes. Third order nonlinear optical parameters generally increase for Pcs in the presence of CdTe quantum dots

MEDICINAL PLANT USE OF VILLAGERS IN THE MOPANI DISTRICT, LIMPOPO PROVINCE, SOUTH AFRICA

Background: An ethnomedical survey of plants was conducted at Mashishimale village near Phalaborwa, in Limpopo Province (South Africa). Owing to high level of poverty and lack of proper daily operational healthcare facilities in certain parts of Mashishimale village, the use of plants as medicine persists. The aim of the study was to compile a list of medicinal plants used by traditional health practitioners for treatment of diabetes mellitus and other ailments. Materials and methods: Traditional health practitioners were identified using the snowballing sampling technique. Structured interviews were conducted and a list of medicinal plants compiled. Data collection included local names of the plants, the plant parts used in the traditional medicine, the disease treated by the plant-based remedies and the method of preparation of the medicines. Results and discussion: A total of 49 plants species belonging to 20 different families we identified. Plant parts used in preparation of remedies by practitioners are roots (51%), stem barks (30%) and leaves (19%). The most preferred methods of administration were boiling (74%) and infusion (12%). About 14 plants species were indicated for treatment of diabetes mellitus, while most plant species were indicated for sexually transmitted diseases, fertility and erectile dysfunction. Conclusion: The results of the survey indicate that plants play a significant role in primary healthcare of the community of Mashishimale Village. It would seem that a number of major diseases/ailments are treated by traditional methods. Scientific investigation is therefore needed to isolate active compounds and to determine safe dosages for treatment. These studies may guide the regulation of herbal medicine industry in South Africa. Key words: Ethnobotanical, Medicinal plants, Mashishimale villag

Urban fuelwood demand and markets in a small town in South Africa: Livelihood vulnerability and alien plant control

Fuelwood is the primary energy for most households throughout the developing world. With increasing urbanization and declining local availability of fuelwood, a growing proportion of households obtain their fuelwood by purchasing it. These fuelwood markets are the key nexus in supply and demand scenarios and can be potentially significant points for intervention to address energy security amongst the urban poor. This paper reports on the fuelwood demand and marketing in a small town in South Africa. Despite the availability of more modern fuels and state subsidization of electricity, fuelwood was still used by half the households. Annual demand was 1.2 t per household. Over half of the households bought their fuelwood requirements because local stocks were limited. Those households that did collect their own fuelwood were significantly poorer than households that purchased fuelwood, as well as households that did not use fuelwood at all. Fuelwood markets operated through 45-60 vendors who transported fuelwood from further afield. Income from the fuelwood trade was low, but was strongly linked to hours worked. Thus, vendors working a full week did earn a meaningful income, especially in the context of high unemployment in the area. Fuelwood vendors also provided casual employment opportunities for unskilled labour. Most vendors harvested fuelwood from commonage lands, with most of the wood being from alien species. Local stocks of wood are declining in the face of constant transformation of commonage to residential areas, and a national water and biodiversity conservation programme to eradicate alien plants. This decline poses a threat to the financial viability of fuelwood markets. Yet, an opportunity exists to incorporate the vendors into the alien plant clearing programme, since they already perform such a function

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

The thermal agitated phase transitions on the Ti32 nanocluster: a molecular dynamics simulation study

Molecular dynamics simulations were performed to investigate the stability with respect to increasing the simulated temperature from 300 to 2400 K of an isolated cluster composed of 32 titanium atoms. The interatomic interactions were modelled using Gupta potentials as implemented within the classical molecular dynamics simulation software DL_POLY. The radial distribution functions (RDF), diffusion coefficient, and density profiles were examined to study the structural changes as a function of temperature. It was found that the Ti32 nanocluster exhibits temperature structural transition. The icosahedron and pentagonal bi-pyramid structures were found to be the most dominant building block fragments. Deformation of the nanocluster was also measured by diffusion coefficient, and it was found that the Ti32 are mobile above the bulk melting point. The phase transitions from solid to liquid have been identified by a simple jump in the total energy curve, with the predicted melting temperature near the bulk melting point (1941.15 K). As expected, the RDF's and density profile peaks decrease with increasing temperatur