1,052 research outputs found

    Understanding the Factors Contributing to the Adoption of Sustainability in Sub-Saharan Africa - A Scoping Study Review

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    Sustainability in the built environment is a key topic of discussion due to the adverse impact buildings have on the environment. This has propelled many countries to put in place sustainable development measures. This has however, been met with challenges in developing countries, primarily in Sub-Saharan Africa (SSA). SSA has a history of endemic energy crisis, despite its abundance of renewable energy resources. Reflecting this is the heavy reliance on fossil fuels for power generation in SSA countries. The findings reported in this paper form part of a wider study on the perceived barriers to sustainability by built environment professionals in SSA, with specific focus on use of renewable energy source (RES) for power generation in buildings. This paper focuses on the identification of a suitable methodology, which takes into consideration the distinctive characteristics of the SSA context for enquiry through the adoption of a scoping study review. The study addresses the concerns of methodology selection and application by reviewing strategies and methods adopted by past and current enquiry in SSA, which have primarily been aligned with theories, frameworks and research in developed countries. This is of importance due to the impact contextual, subjective and other factors can have on the outcome of enquiry as evidenced by previous research in literature. The purpose of this scoping study review was to provide a comprehensive overview of the available relevant research on barriers to sustainability in SSA, which focused on study designs with empirical evidence, which would aid in informing the selection of a methodology suited for studies specific to the context of SSA. The scoping review is underpinned by the five-stage framework of Arksey and O’Malley (2005). The results indicate that there is a need to view SSA as a distinctive case based on its context and other characteristics, which will influences its research outcomes. Based on the review, it is suggested that grounded theory method is a suitable approach because it will take into consideration the wider context

    Validity of a tool designed to assess the preventability of potentially preventable hospitalizations for chronic conditions

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    Background: Potentially preventable hospitalizations (PPH) are defined as unplanned hospital admissions which could potentially have been prevented with the provision of effective, timely outpatient care. To better understand and ultimately reduce rates of PPH, a means of identifying those which are actually preventable is required. The Preventability Assessment Tool (PAT) was designed for use by hospital clinicians to assess the preventability of unplanned admissions for chronic conditions. Objective: The present study examined the ability of the PAT to distinguish between those unplanned admissions which are preventable and those which are not, compared to the assessments of an Expert Panel. Methods: Data were collected between November 2014 and June 2017 at three hospitals in NSW, Australia. Participants were community-dwelling patients with unplanned hospital admissions for congestive heart failure, chronic obstructive pulmonary disease, diabetes complications or angina pectoris. A nurse and a doctor caring for the patient made assessments of the preventability of the admission using the PAT. Expert Panels made assessments of the preventability of each admission based on a comprehensive case report and consensus process. Results: There was little concordance between the hospital doctors and nurses regarding the preventability of admissions, nor between the assessments of the Expert Panel and the hospital nurse or the Expert Panel and the hospital doctor. Conclusions: The PAT demonstrated poor concurrent validity and is not a valid tool for assessing the preventability of unplanned hospital admissions. The use of Expert Panels provides a more rigorous approach to assessing the preventability of such admissions

    Direct Evidence of the Exfoliation Efficiency and Graphene Dispersibility of Green Solvents toward Sustainable Graphene Production

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    Achieving a sustainable production of pristine high-quality graphene and other layered materials at a low cost is one of the bottlenecks that needs to be overcome for reaching 2D material applications at a large scale. Liquid phase exfoliation in conjunction with N-methyl-2-pyrrolidone (NMP) is recognized as the most efficient method for both the exfoliation and dispersion of graphene. Unfortunately, NMP is neither sustainable nor suitable for up-scaling production due to its adverse impact on the environment. Here, we show the real potential of green solvents by revealing the independent contributions of their exfoliation efficiency and graphene dispersibility to the graphene yield. By experimentally separating these two factors, we demonstrate that the exfoliation efficiency of a given solvent is independent of its dispersibility. Our studies revealed that isopropanol can be used to exfoliate graphite as efficiently as NMP. Our finding is corroborated by the matching ratio between the polar and dispersive energies of graphite and that of the solvent surface tension. This direct evidence of exfoliation efficiency and dispersibility of solvents paves the way to developing a deeper understanding of the real potential of sustainable graphene manufacturing at a large scale

    Health related values and preferences regarding meat intake : a cross-sectional mixed-methods study

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    Background. In addition to social and environmental determinants, people's values and preferences determine daily food choices. This study evaluated adults' values and preferences regarding unprocessed red meat (URM) and processed meat (PM) and their willingness to change their consumption in the face of possible undesirable health consequences. Methods. A crosssectional mixed-methods study including a quantitative assessment through an online survey, a qualitative inquiry through semi-structured interviews, and a follow-up assessment through a telephone survey. We performed descriptive statistics, logistic regressions, and thematic analysis. Results. Of 304 participants, over 75% were unwilling to stop their consumption of either URM or PM, and of those unwilling to stop, over 80% were also unwilling to reduce. Men were less likely to stop meat intake than women (odds ratios < 0.4). From the semi-structured interviews, we identified three main themes: the social and/or family context of meat consumption, healthand non-health-related concerns about meat, and uncertainty of the evidence. At three months, 63% of participants reported no changes in meat intake. Conclusions. When informed about the cancer incidence and mortality risks of meat consumption, most respondents would not reduce their intake. Public health and clinical nutrition guidelines should ensure that their recommendations are consistent with population values and preferences

    Phase Separation and Magnetic Order in K-doped Iron Selenide Superconductor

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    Alkali-doped iron selenide is the latest member of high Tc superconductor family, and its peculiar characters have immediately attracted extensive attention. We prepared high-quality potassium-doped iron selenide (KxFe2-ySe2) thin films by molecular beam epitaxy and unambiguously demonstrated the existence of phase separation, which is currently under debate, in this material using scanning tunneling microscopy and spectroscopy. The stoichiometric superconducting phase KFe2Se2 contains no iron vacancies, while the insulating phase has a \surd5\times\surd5 vacancy order. The iron vacancies are shown always destructive to superconductivity in KFe2Se2. Our study on the subgap bound states induced by the iron vacancies further reveals a magnetically-related bipartite order in the superconducting phase. These findings not only solve the existing controversies in the atomic and electronic structures in KxFe2-ySe2, but also provide valuable information on understanding the superconductivity and its interplay with magnetism in iron-based superconductors

    Spin- and energy relaxation of hot electrons at GaAs surfaces

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    The mechanisms for spin relaxation in semiconductors are reviewed, and the mechanism prevalent in p-doped semiconductors, namely spin relaxation due to the electron-hole exchange interaction, is presented in some depth. It is shown that the solution of Boltzmann-type kinetic equations allows one to obtain quantitative results for spin relaxation in semiconductors that go beyond the original Bir-Aronov-Pikus relaxation-rate approximation. Experimental results using surface sensitive two-photon photoemission techniques show that the spin relaxation-time of electrons in p-doped GaAs at a semiconductor/metal surface is several times longer than the corresponding bulk spin relaxation-times. A theoretical explanation of these results in terms of the reduced density of holes in the band-bending region at the surface is presented.Comment: 33 pages, 12 figures; earlier submission replaced by corrected and expanded version; eps figures now included in the tex
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