2,442 research outputs found

    The prevalence of burnout among chiropractors in South Africa

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    Abstract: Aim: The aim of this study was to determine the prevalence of burnout among doctors of chiropractic in South Africa and compare these results with burnout data from other healthcare professionals and chiropractors from other countries. Method: This investigative qualitative study applied cross-sectional data collection using nonprobability convenience sampling. The Chiropractic Association of South Africa provided contact information of all the registered chiropractors on their members register. Participants included in the study were qualified and registered chiropractors whose primary occupation involved the chiropractic profession. The Maslach Burnout Inventory – Human Services Survey for Medical Personnel (MBIHSS (MP)) and a 20-question demographic questionnaire were emailed to a random sample of registered chiropractors. Results: The survey return rate was 11.3%. Of the 700 surveys sent out, 83 surveys were returned to the researcher. Only data from 79 surveys was useable. Of those surveyed, 12.7% reported a high level of emotional exhaustion, while 36.7% reported a moderate level. A further 7.6% reported a moderate level of depersonalisation. In total, two participants (2.5%) met the criteria for severe burnout and two participants (2.5%) for high levels of burnout. The majority, 71 participants (90%), had low level of burnout and 94% of chiropractors scored outstanding levels of personal accomplishment. Statistically significant associations were found between burnout subdivisions and the effect of time dedicated to administrative tasks, the number of hours worked per week, the public’s opinion on chiropractors, the varying chiropractic philosophical perspectives and the consequence of suffering from a work-related injury. When comparing the data from this study with data from other healthcare professionals who used the MBI-HSS (MP) and with chiropractors from other countries, the rate of burnout among chiropractors in South Africa is significantly low. Conclusion: The representatives of chiropractors in this study had encouraging scores in all three subdivisions of burnout. They revealed lower emotional exhaustion and depersonalisation levels and higher personal accomplishment levels than other medical professionals such as nurses, dentists, medical specialists and physical and occupational therapists. The sample of chiropractors had better scores in all subdivisions than the chiropractors in America who have been evaluated using the MBIHSS (MP).M.Tech. (Chiropractic

    Performance and Operability of a Dual Cavity Flame Holder in a Supersonic Combustor

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    The current generation of hydrocarbon fueled scramjet combustors typically requires a flame holding device to facilitate flame ignition and stable combustion. The amount of time available for fuel injection, fuel-air mixing, and combustion is very short, on the order of 1 millisecond. This short dwell time, along with the relatively long ignition delay times of hydrocarbon fuels, makes the flow path and flame holder design extremely important. This study investigates the performance and operability of using a symmetric dual cavity flame holder flow path to stabilize and enhance supersonic combustion. Testing of this flow path configuration, as well as a baseline single cavity flow path, was conducted in Research Cell 18 of the Propulsion Directorate at the Air Force Research Laboratory (AFRL/RZ). Performance and operability of the flow paths were determined through analysis of wall pressures, temperatures, pressure ratios, stream thrusts, combustion efficiencies, computational fluid dynamics, and visualization. The dual cavity flame holder showed a significant overall increase in performance through higher temperatures, pressure ratios, and stream thrusts. This research has proven the potential of a dual cavity flame holder to provide improved performance for a reliable scramjet engine

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    Optimization of Nordsieck's Method for the Numerical Integration of Ordinary Differential Equations

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    Stability and accuracy of Nordsieck's integration method can be improved by choosing the zero-positions of the extraneous roots of the characteristic equation in a suitable way. Optimum zero-positions have been found by minimizing the lower bound of the interval of absolute stability and the coefficient of the truncation error. Various properties of the improved methods have been analysed, such as the behaviour of the high-order terms, the equivalence with multistep methods and the damping of perturbations

    Spatial Variability in Column CO2 Inferred from High Resolution GEOS-5 Global Model Simulations: Implications for Remote Sensing and Inversions

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    Column CO2 observations from current and future remote sensing missions represent a major advancement in our understanding of the carbon cycle and are expected to help constrain source and sink distributions. However, data assimilation and inversion methods are challenged by the difference in scale of models and observations. OCO-2 footprints represent an area of several square kilometers while NASA s future ASCENDS lidar mission is likely to have an even smaller footprint. In contrast, the resolution of models used in global inversions are typically hundreds of kilometers wide and often cover areas that include combinations of land, ocean and coastal areas and areas of significant topographic, land cover, and population density variations. To improve understanding of scales of atmospheric CO2 variability and representativeness of satellite observations, we will present results from a global, 10-km simulation of meteorology and atmospheric CO2 distributions performed using NASA s GEOS-5 general circulation model. This resolution, typical of mesoscale atmospheric models, represents an order of magnitude increase in resolution over typical global simulations of atmospheric composition allowing new insight into small scale CO2 variations across a wide range of surface flux and meteorological conditions. The simulation includes high resolution flux datasets provided by NASA s Carbon Monitoring System Flux Pilot Project at half degree resolution that have been down-scaled to 10-km using remote sensing datasets. Probability distribution functions are calculated over larger areas more typical of global models (100-400 km) to characterize subgrid-scale variability in these models. Particular emphasis is placed on coastal regions and regions containing megacities and fires to evaluate the ability of coarse resolution models to represent these small scale features. Additionally, model output are sampled using averaging kernels characteristic of OCO-2 and ASCENDS measurement concepts to create realistic pseudo-datasets. Pseudo-data are averaged over coarse model grid cell areas to better understand the ability of measurements to characterize CO2 distributions and spatial gradients on both short (daily to weekly) and long (monthly to seasonal) time scale

    Conforming finite element methods for the clamped plate problem

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    Finite element methods for solving biharmonic boundary value problems are considered. The particular problem discussed is that of a clamped thin plate. This problem is reformulated in a weak, form in the Sobolev space Techniques for setting up conforming trial Functions are utilized in a Galerkin technique to produce finite element solutions. The shortcomings of various trial function formulations are discussed, and a macro—element approach to local mesh refinement using rectangular elements is given

    An Accelerated Conjugate Gradient Algorithm to Compute Low-Lying Eigenvalues --- a Study for the Dirac Operator in SU(2) Lattice QCD

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    The low-lying eigenvalues of a (sparse) hermitian matrix can be computed with controlled numerical errors by a conjugate gradient (CG) method. This CG algorithm is accelerated by alternating it with exact diagonalisations in the subspace spanned by the numerically computed eigenvectors. We study this combined algorithm in case of the Dirac operator with (dynamical) Wilson fermions in four-dimensional \SUtwo gauge fields. The algorithm is numerically very stable and can be parallelized in an efficient way. On lattices of sizes 44−1644^4-16^4 an acceleration of the pure CG method by a factor of~4−84-8 is found.Comment: 25 pages, uuencoded tar-compressed .ps-fil

    Analysis of the Relationship Between Climate and NDVI Variability at Global Scales

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    interannual variability in modeled (CASA) C flux is in part caused by interannual variability in Normalized Difference Vegetation Index (NDVI) Fraction of Photosynthetically Active Radiation (FPAR). This study confirms a mechanism producing variability in modeled NPP: -- NDVI (FPAR) interannual variability is strongly driven by climate; -- The climate driven variability in NDVI (FPAR) can lead to much larger fluctuation in NPP vs. the NPP computed from FPAR climatolog
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