Nanoscale stacking fault-assisted room temperature plasticity in flash-sintered TiO2.

Ceramic materials have been widely used for structural applications. However, most ceramics have rather limited plasticity at low temperatures and fracture well before the onset of plastic yielding. The brittle nature of ceramics arises from the lack of dislocation activity and the need for high stress to nucleate dislocations. Here, we have investigated the deformability of TiO2 prepared by a flash-sintering technique. Our in situ studies show that the flash-sintered TiO2 can be compressed to ~10% strain under room temperature without noticeable crack formation. The room temperature plasticity in flash-sintered TiO2 is attributed to the formation of nanoscale stacking faults and nanotwins, which may be assisted by the high-density preexisting defects and oxygen vacancies introduced by the flash-sintering process. Distinct deformation behaviors have been observed in flash-sintered TiO2 deformed at different testing temperatures, ranging from room temperature to 600°C. Potential mechanisms that may render ductile ceramic materials are discussed

Anisotropic lattice expansion determined during flash sintering of BiFeO3 by in-situ energy-dispersive X-ray diffraction

BiFeO3 has a Curie temperature (TC) of 825 °C, making it difficult to sinter using conventional methods while maintaining the purity of the material, as unavoidably secondary phases appear at temperatures above Tc. Flash sintering is a relatively new technique that saves time and energy compared to other sintering methods. BiFeO3 was flash sintered at 500 °C to achieve 90% densification. In-situ energy dispersive X-ray diffraction (EDXRD) revealed that the material did not undergo any phase transformation, having been sintered well below the TC. Interestingly, anisotropic lattice expansion in the material was observed when the sample was exposed to the electric field.U.S. Office of Naval Research (ONR) N00014-10-1- 042, N00014-17-1-2087, Sub 4104-78982U.S. Department of Energy DE-AC02-06CH1135

"It's not like taking chocolates": factors influencing the feasibility and sustainability of universal test and treat in correctional health systems in Zambia and South Africa

Background: Sub-Saharan African correctional facilities concentrate large numbers of people who are living with HIV or at risk for HIV infection. Universal test and treat (UTT) is widely recognized as a promising approach to improve the health of individuals and a population health strategy to reduce new HIV infections. In this study, we explored the feasibility and sustainability of implementing UTT in correctional facilities in Zambia and South Africa. Methods: Nested within a UTT implementation research study, our qualitative evaluation of feasibility and sustainability used a case-comparison design based on data from 1 Zambian and 3 South African correctional facilities. Primary data from in-depth interviews with incarcerated individuals, correctional managers, health care providers, and policy makers were supplemented by public policy documents, study documentation, and implementation memos in both countries. Thematic analysis was informed by an empirically established conceptual framework for health system analysis. Results: Despite different institutional profiles, we were able to successfully introduce UTT in the South Africa and Zambian correctional facilities participating in the study. A supportive policy backdrop was important to UTT implementation and establishment in both countries. However, sustainability of UTT, defined as relevant government departments' capacity to independently plan, resource, and administer quality UTT, differed. South Africa's correctional facilities had existing systems to deliver and monitor chronic HIV care and treatment, forming a “scaffolding” for sustained UTT despite some human resources shortages and poorly integrated health information systems. Notwithstanding recent improvements, Zambia's correctional health system demonstrated insufficient material and technical capacity to independently deliver quality UTT. In the correctional facilities of both countries, inmate population dynamics and their impact on HIV-related stigma were important factors in UTT service uptake. Conclusion: Findings demonstrate the critical role of policy directives, health service delivery systems, adequate resourcing, and population dynamics on the feasibility and likely sustainability of UTT in corrections in Zambia and South Africa

Costs of implementing universal test and treat in three correctional facilities in South Africa and Zambia.

INTRODUCTION: Universal test and treat (UTT) is a population-based strategy that aims to ensure widespread HIV testing and rapid antiretroviral therapy (ART) for all who have tested positive regardless of CD4 count to decrease HIV incidence and improve health outcomes. Little is known about the specific resources required to implement UTT in correctional facilities for incarcerated people. The primary aim of this study was to describe the resources used to implement UTT and to provide detailed costing to inform UTT scale-up in similar settings. METHODS: The costing study was a cross-sectional descriptive study conducted in three correctional complexes, Johannesburg Correctional Facility in Johannesburg (>4000 inmates) South Africa, and Brandvlei (~3000 inmates), South Africa and Lusaka Central (~1400 inmates), Zambia. Costing was determined through a survey conducted between September and December 2017 that identified materials and labour used for three separate components of UTT: HIV testing services (HTS), ART initiation, and ART maintenance. Our study participants were staff working in the correctional facilities involved in any activity related to UTT implementation. Unit costs were reported as cost per client served while total costs were reported for all clients seen over a 12-month period. RESULTS: The cost of HIV testing services (HTS) per client was $92.12 at Brandvlei,$ 73.82 at Johannesburg, and $65.15 at Lusaka. The largest cost driver for HIV testing at Brandvlei were staff costs at 55.6$917 for Brandvlei, $421.8 for Johannesburg, and$252.1 for Lusaka. The activity cost drivers were adherence counselling at Brandvlei (59%), and at Johannesburg and Lusaka it was the actual ART initiation at 75.6% and 75.8%, respectively. The annual unit cost for ART maintenance was $2,640.6 for Brandvlei,$710 for Johannesburg, and $385.5 for Lusaka. The activity cost drivers for all three facilities were side effect monitoring, and initiation of isoniazid preventive treatment (IPT), cotrimoxazole, and fluconazole, with this comprising 44.7% of the total cost at Brandvlei, 88.9% at Johannesburg, and 50.5% at Lusaka. CONCLUSION: Given the needs of this population, the opportunity to reach inmates at high risk for HIV, and overall national and global 95-95-95 goals, the UTT policies for incarcerated individuals are of vital importance. Our findings provide comparator costing data and highlight key drivers of UTT cost by facility

Costs of implementing universal test and treat in three correctional facilities in South Africa and Zambia

Introduction Universal test and treat (UTT) is a population-based strategy that aims to ensure widespread HIV testing and rapid antiretroviral therapy (ART) for all who have tested positive regardless of CD4 count to decrease HIV incidence and improve health outcomes. Little is known about the specific resources required to implement UTT in correctional facilities for incarcerated people. The primary aim of this study was to describe the resources used to implement UTT and to provide detailed costing to inform UTT scale-up in similar settings. Methods The costing study was a cross-sectional descriptive study conducted in three correctional complexes, Johannesburg Correctional Facility in Johannesburg (>4000 inmates) South Africa, and Brandvlei (~3000 inmates), South Africa and Lusaka Central (~1400 inmates), Zambia. Costing was determined through a survey conducted between September and December 2017 that identified materials and labour used for three separate components of UTT: HIV testing services (HTS), ART initiation, and ART maintenance. Our study participants were staff working in the correctional facilities involved in any activity related to UTT implementation. Unit costs were reported as cost per client served while total costs were reported for all clients seen over a 12-month period. Results The cost of HIV testing services (HTS) per client was $92.12 at Brandvlei,$ 73.82 at Johannesburg, and $65.15 at Lusaka. The largest cost driver for HIV testing at Brandvlei were staff costs at 55.6$917 for Brandvlei, $421.8 for Johannesburg, and$252.1 for Lusaka. The activity cost drivers were adherence counselling at Brandvlei (59%), and at Johannesburg and Lusaka it was the actual ART initiation at 75.6% and 75.8%, respectively. The annual unit cost for ART maintenance was $2,640.6 for Brandvlei,$710 for Johannesburg, and $385.5 for Lusaka. The activity cost drivers for all three facilities were side effect monitoring, and initiation of isoniazid preventive treatment (IPT), cotrimoxazole, and fluconazole, with this comprising 44.7% of the total cost at Brandvlei, 88.9% at Johannesburg, and 50.5% at Lusaka. Conclusion Given the needs of this population, the opportunity to reach inmates at high risk for HIV, and overall national and global 95-95-95 goals, the UTT policies for incarcerated individuals are of vital importance. Our findings provide comparator costing data and highlight key drivers of UTT cost by facility

Abstracts from the NIHR INVOLVE Conference 2017

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Designing for the elderly : total care & the elderly lifestyle

Thesis (Undergrad) -- University of Melbourne, Faculty of Architecture, Building and Town & Regional Plannin

Insight into the BiFeO3 flash sintering process by in-situ energy dispersive X-ray diffraction (ED-XRD)

The sintering mechanism of BiFeO3 has been investigated in-situ by energy dispersive X-ray diffraction (ED-XRD) using a high-energy white collimated X-ray beam from the Advanced Photon Source (Argonne National Laboratories). Such radiation is very penetrating thereby allowing measurements of the sample even when placed inside the flash sintering set up. Additionally, the fast ED-XRD measurements permit monitoring the flash sintering process by providing information about phase composition and sample temperature in real time. Moreover, profile scans, obtained by moving the stage vertically while recording the ED-XRD spectra, permit investigating the homogeneity of the flash for the entire length of the sample. All experiments have been complemented by ex-situ studies. It has been concluded that flash sintering of BiFeO3 is a homogeneous process without any directionality effects. Furthermore, flash sintering takes place at quite low temperatures (below the Tc ≈ 830 °C), which may be related to the high quality of the samples, as pure, highly insulating ceramics without evidence of secondary phases with a homogenous nanostructured grain size distribution are obtained by this technique. Moreover, it is also evidenced that the rapid heating of the sample does not seem to justify, at least by itself, the densification process. Therefore, it appears that the electric current should play a role in the enhanced mobility during the sintering process.Office of Naval Research (ONR) N00014-10-1-042, N00014-17-1-208, 4104-7898DOE Office of Science by Argonne National Laboratory DE-AC02-06CH11357Ministerio de Economía y Competitividad Q2014-52763-C2-1-R, CTQ2017-83602-C2Junta de Andalucía TEP-785

Cation reordering instead of phase transitions: Origins and implications of contrasting lithiation mechanisms in 1D ζ- and 2D α-V2O5

Substantial improvements in cycle life, rate performance, accessible voltage, and reversible capacity are required to realize the promise of Li-ion batteries in full measure. Here, we have examined insertion electrodes of the same composition (V(2)O(5)) prepared according to the same electrode specifications and comprising particles with similar dimensions and geometries that differ only in terms of their atomic connectivity and crystal structure, specifically two-dimensional (2D) layered α-V(2)O(5) that crystallizes in an orthorhombic space group and one-dimensional (1D) tunnel-structured ζ-V(2)O(5) crystallized in a monoclinic space group. By using particles of similar dimensions, we have disentangled the role of specific structural motifs and atomistic diffusion pathways in affecting electrochemical performance by mapping the dynamical evolution of lithiation-induced structural modifications using ex situ scanning transmission X-ray microscopy, operando synchrotron X-ray diffraction measurements, and phase-field modeling. We find the operation of sharply divergent mechanisms to accommodate increasing concentrations of Li-ions: a series of distortive phase transformations that result in puckering and expansion of interlayer spacing in layered α-V(2)O(5), as compared with cation reordering along interstitial sites in tunnel-structured ζ-V(2)O(5). By alleviating distortive phase transformations, the ζ-V(2)O(5) cathode shows reduced voltage hysteresis, increased Li-ion diffusivity, alleviation of stress gradients, and improved capacity retention. The findings demonstrate that alternative lithiation mechanisms can be accessed in metastable compounds by dint of their reconfigured atomic connectivity and can unlock substantially improved electrochemical performance not accessible in the thermodynamically stable phase