408 research outputs found

    The impact of varying statutory arrangements on spatial data sharing and access in regional NRM bodies

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    Spatial information plays an important role in many social, environmental and economic decisions and increasingly acknowledged as a national resource essential for wider societal and environmental benefits. Natural Resource Management is one area where spatial information can be used for improved planning and decision making processes. In Australia, state government organisations are the custodians of spatial information necessary for natural resource management and regional NRM bodies are responsible to regional delivery of NRM activities. The access and sharing of spatial information between government agencies and regional NRM bodies is therefore as an important issue for improving natural resource management outcomes. The aim of this paper is to evaluate the current status of spatial information access, sharing and use with varying statutory arrangements and its impacts on spatial data infrastructure (SDI) development in catchment management sector in Australia. Further, it critically examined whether any trends and significant variations exist due to different institutional arrangements (statutory versus non-statutory) or not. A survey method was used to collect primary data from 56 regional natural resource management (NRM) bodies responsible for catchment management in Australia. Descriptive statistics method was used to show the similarities and differences between statutory and non-statutory arrangements. The key factors which influence sharing and access to spatial information are also explored. The results show the current statutory and administrative arrangements and regional focus for natural resource management is reasonable from a spatial information management perspective and provides an opportunity for building SDI at the catchment scale. However, effective institutional arrangements should align catchment SDI development activities with sub-national and national SDI development activities to address catchment management issues. We found minor differences in spatial information access, use and sharing due to varying institutional environment (statutory versus non-statutory). The non-statutory group appears to be more flexible and self-sufficient whilst statutory regional NRM bodies may lack flexibility in their spatial information management practices. We found spatial information access, use and sharing has significant impacts on spatial data infrastructure development in catchment management sector in Australia

    Mapping long-period soil resonances in the Kathmandu basin using microtremors

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    This study reports the geostatistical analysis of a set of 40 single-station horizontal-to-vertical spectral ratio (HVSR) passive seismic survey data collected in the Kathmandu basin (Nepal). The Kathmandu basin is characterized by a heterogeneous sedimentary cover and by a complex geo-structural setting, inducing a high spatial variability of the bedrock depth. Due to the complex geological setting, the interpretation and analysis of soil resonance periods derived from the HVSR surveys is challenging, both from the perspective of bedrock depth estimation as well as of seismic-site effects characterization. To exploit the available information, the HVSR data are analyzed by means of a geostatistical approach. First, the spatial continuity structure of HVSR data is investigated and interpreted taking into consideration the geological setting and available stratigraphic and seismic information. Then, the exploitation of potential auxiliary variables, based on surface morphology and distance from outcropping bedrock, is evaluated. Finally, the mapping of HVSR resonance periods, together with the evaluation of interpolation uncertainty, is obtained by means of kriging with external drift interpolation. This work contributes to the characterization of local seismic response of the Kathmandu basin. The resulting map of soil resonance periods is compatible with the results of preceding studies and it is characterized by a high spatial variability, even in areas with a deep bedrock and long resonance periods

    Electronic, magnetic, and magnetocrystalline anisotropy properties of light lanthanides

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    Theoretical understanding of interactions between localized and mobile electrons and the crystal environment in light lanthanides is important because of their key role in much needed magnetic anisotropy in permanent magnet materials that have a great impact in automobile and wind turbine applications. We report electronic, magnetic, and magnetocrystalline properties of these basic light lanthanide elements studied from advanced density functional theory (DFT) calculations. We find that the inclusion of onsite 4f electron correlation and spin orbit coupling within the full-potential band structure is needed to understand the unique magnetocrystalline properties of these light lanthanides. The onsite electron correlation, spin orbit coupling, and full potential for the asphericity of charge densities must be taken into account for the proper treatment of 4f states. We find the variation of total energy as a function of lattice constants that indicate multiple structural phases in Ce contrasting to a single stable structure obtained in other light lanthanides. The 4f orbital magnetic moments are partially quenched as a result of crystalline electric field splitting that leads to magnetocrystalline anisotropy. The charge density plots have similar asphericity and environment in Pr and Nd indicating similar magnetic anisotropy. However, Ce and Sm show completely different asphericity and environment as both orbital moments are significantly quenched. In addition, the Fermi surface structures exemplified in Nd indicate structural stability and unravel a cause of anisotropy. The calculated magnetocrystalline anisotropy energy (MAE) reveals competing c-axis and in-plane anisotropies, and also predicts possibilities of unusual structural deformations in light lanthanides. The uniaxial magnetic anisotropy is obtained in the double hexagonal closed pack structures of the most of the light lanthanides, however, the anisotropy is reduced or turned to planar in the low symmetry structures. Through crystal field calculations we also illustrate the crystal field ground state 4f multiplets of light lanthanides

    Temperature dependent carrier lifetime studies on Ti-doped multicrystalline silicon

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    Carrier lifetimemeasurements were performed on deliberately Ti-doped multicrystalline silicon wafers using a temperature controlled photoconductance device. The dominant recombination center was found to be the double-donor level associated with interstitial titanium. The interstitial Ti concentrations in multicrystalline silicon wafers were determined by measuring the Shockley–Read–Hall time constant for holes and using the known values of the thermal velocity and capture cross section for holes of the double-donor level at different temperatures. The measured values of the Ti concentration were then used to determine the electron capture cross section of the double-donor level over the temperature range of 140–270 °C via the measured values of the Shockley–Read–Hall time constant for electrons and the known thermal velocity. Multiphonon emission was found to be the most likely capture mechanism for this temperature range for electron capture into the double-donor level of Ti in silicon. The effective segregation coefficient for Ti was estimated by fitting Scheil’s equation to the measured values of the Ti concentrations and their respective vertical positions in the ingot. If all Ti were present as the interstitial double-donor, a lower limit of 1.8×10⁻⁶ can be ascribed to the segregation coefficient, which is very close to the equilibrium value.This work was funded by an Australian Research Council Linkage Grant between the Australian National University, SierraTherm Production Furnaces, and SunPower Corporation. D.H.M. is supported by an Australian Research Council fellowship

    The health and wellbeing of offshore workers: a narrative review of the published literature.

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    Recent developments within the offshore industry have highlighted the role that health and wellbeing plays in ensuring the safety and longevity of the offshore workforce. Developing an understanding of the overall health and wellbeing of offshore workers could aid future developments. This narrative review aims to identify and synthesise the relevant published literature on offshore health and wellbeing. The Cochrane Library, Cumulative Index to Nursing and Allied Health Literature, Medical Literature Analysis and Retrieval System Online, PsycArticles, and Web of Science databases were searched with publication search dates limited from January 1994 to November 2014. Twenty-six studies were identified and covered aspects of occupational stress; mental wellbeing; body mass index; diet; physical activity; musculoskeletal disorder; smoking; alcohol and drug use; shift work amongst offshore workers. This narrative review has highlighted a lack of high quality and relevant research. There is a particular need to research workers' participation in self care activities and the resultant influence of domains on health and well being. NOTE: publisher link is not currently working (last checked 2019-01-25

    Evaluation of work-related psychosocial factors and regional musculoskeletal pain: results from a EULAR Task Force

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    Objectives: to establish whether review articles provide consistent conclusions on associations between workplace psychosocial factors and musculoskeletal pain and, if differences exist, to explore whether this is related to the methods used.Methods: reviews, reported up to February 2007, that included consideration of workplace psychosocial factors and upper limb, back or knee pain were identified through searches of multiple databases. The specific work-related psychosocial factors considered were job demands, support, job autonomy and job satisfaction. The conclusions of each review on one or more of the psychosocial/musculoskeletal pain associations were extracted.Results: 15 review articles were identified that considered one or more of the regional pain syndromes included in the study. For back pain, the most consistent conclusions (four reviews positive out of six) were with high job demands and low job satisfaction. The studies of upper limb pain were exclusively related to shoulder and/or neck pain, and the most consistent positive conclusions were with high and low job demands (four reviews positive out of six and two reviews positive out of three, respectively). For knee pain, only a single review was identified. For individual reviews of back and upper limb pain, there were marked differences in the number of associations concluded to be positive between reviews.Conclusions: the reasons for reviews coming to different conclusions included that they were often evaluating different bodies of evidence (according to their search criteria, the year when the review was conducted, the role that quality assessment played in whether studies contributed to evidence, and the combination of risk factors addressed in individual studies), but more important was whether the review specified explicit criteria for making conclusions on strength of evidence. These conclusions emphasise the importance of developing standardised methods for conducting such evaluations of existing evidence and the importance of new longitudinal studies for clarifying the temporal relationship between psychosocial factors and musculoskeletal pain in the workplac

    Complex magnetism of lanthanide intermetallics unravelled

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    We explain a profound complexity of magnetic interactions of some technologically relevant gadolinium intermetallics using an ab-initio electronic structure theory which includes disordered local moments and strong ff-electron correlations. The theory correctly finds GdZn and GdCd to be simple ferromagnets and predicts a remarkably large increase of Curie temperature with pressure of +1.5 K kbar1^{-1} for GdCd confirmed by our experimental measurements of +1.6 K kbar1^{-1}. Moreover we find the origin of a ferromagnetic-antiferromagnetic competition in GdMg manifested by non-collinear, canted magnetic order at low temperatures. Replacing 35\% of the Mg atoms with Zn removes this transition in excellent agreement with longstanding experimental data.Comment: 11 pages, 4 figure

    Phase stability analysis in Fe-Pt and Co-Pt alloy systems: An augmented space study

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    We have studied the problem of phase stability in Fe-Pt and Co-Pt alloy systems. We have used the orbital peeling technique in the conjunction of augmented space recursion based on the tight binding linear orbital method as the method for the calculation of pair interaction energies. In particular, we have generalized our earlier technique to take into account of magnetic effects for the cases where the magnetic transition is higher than the order disorder chemical transition temperature as in the case of Co3_3Pt. Our theoretical results obtained within this framework successfully reproduce the experimentally observed trends.Comment: 17 pages, 9 Figures. Accepted for publication in Journal of Physics : Condensed Matte
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