385 research outputs found

    Project on comparison of structural parameters and electron density maps of oxalic acid dihydrate

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    Results obtained from four X-ray and five neutron data sets collected under a project sponsored by the Commission on Charge, Spin and Momentum Densities are analyzed by comparison of thermal parameters, positional parameters and X - N electron density maps. Three sets of theoretical calculations are also included in the comparison. Though several chemically significant features are reproduced in all the experimental density maps, differences in detail occur which caution against overinterpretation of the maps. Large differences between vibrational tensor elements Uij are observed which can often not be corrected by the scaling of all temperature parameters in a set. Positional parameters are reproducible to precisions of 0.001 Å or better. The biggest discrepancies between theoretical and experimental deformation density maps occurs in the lone-pair regions where peaks are higher in the theoretical maps. However, this comparison may be affected by inadequacies in the thermal-motion formalism which must be invoked before experimental and theoretical maps can be compared in a quantitative way

    Docking and Bridging Devices

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    This disclosure describes core devices, like a phone, tablet, or other screen, and how they could be docked to a second device, like a speaker or charger, to take on a new role. This disclosure describes a system that offers more flexibility and allows users to benefit from different combinations of devices. The techniques allow an object to be docked to effectively create a new device, e.g., a tablet docking to a speaker would be like a home hub, and/or to alter their function, e.g., a phone can be placed in a stand or on a charging mat to default to a more passive role

    Particle-resolved hyperspectral pyrometry of metal particles

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    We present temperature histories of individual combusting metal particles using hyperspectral pyrometry. This method gives an increase in accuracy over traditionally used two- or three-color pyrometry, while maintaining temporal and spatial resolution. Temperatures can be determined between 1800 to K with a precision of typically 1%. It is shown that the maximum temperature of the burning iron particles increases from 2760 K to 2840 K with an increasing mean particle size from 32 to 54m in air with 21 % oxygen. The relatively high temperatures and its dependence on particle size are possibly related to flow field properties of the current experimental setup. Opportunities for this method, as well as future work, are discussed.Novelty and Significance Statement: In this article, a method to use a CCD camera and spectrograph as a hyperspectral detector, gaining a wavelength dimension while maintaining two spatial dimensions, is demonstrated and validated. This method is applied to measure the temperature of iron particles, a carbon free and circular energy carrier. This method is then used to prove that there is a particle size dependence on the maximum temperature, an open question which is often disputed in literature. This work will also add a dataset that can be used for the validation of numerical models. There are only two such datasets available for iron at this moment. Our analysis suggests that the heat release of iron is dependent on the slip velocity, possibly due to a circulating flow inside of the particle

    Numerical Simulations of Gravity-Driven Fingering in Unsaturated Porous Media Using a Non-Equilibrium Model

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    This is a computational study of gravity-driven fingering instabilities in unsaturated porous media. The governing equations and corresponding numerical scheme are based on the work of Nieber et al. [Ch. 23 in Soil Water Repellency, eds. C. J. Ritsema and L. W. Dekker, Elsevier, 2003] in which non-monotonic saturation profiles are obtained by supplementing the Richards equation with a non-equilibrium capillary pressure-saturation relationship, as well as including hysteretic effects. The first part of the study takes an extensive look at the sensitivity of the finger solutions to certain key parameters in the model such as capillary shape parameter, initial saturation, and capillary relaxation coefficient. The second part is a comparison to published experimental results that demonstrates the ability of the model to capture realistic fingering behaviour

    Combining transplant professional's psychosocial donor evaluation and donor self-report measures to optimise the prediction of HRQoL after kidney donation:an observational prospective multicentre study

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    OBJECTIVES: Living donor kidney transplantation is currently the preferred treatment for patients with end-stage renal disease. The psychosocial evaluation of kidney donor candidates relies mostly on the clinical viewpoint of transplant professionals because evidence-based guidelines for psychosocial donor eligibility are currently lacking. However, the accuracy of these clinical risk judgements and the potential added value of a systematic self-reported screening procedure are as yet unknown. The current study examined the effectiveness of the psychosocial evaluation by transplant professionals and the potential value of donor self-report measures in optimising the donor evaluation. Based on the stress-vulnerability model, the predictive value of predonation, intradonation and postdonation factors to impaired longer term health-related quality of life (HRQoL) of kidney donors was studied. DESIGN: An observational prospective multicentre study. SETTING: Seven Dutch transplantation centres. PARTICIPANTS: 588 potential donors participated, of whom 361 donated. Complete prospective data of 230 donors were available. Also, 1048 risk estimation questionnaires were completed by healthcare professionals. METHODS: Transplant professionals (nephrologists, coordinating nurses, social workers and psychologists) filled in risk estimation questionnaires on kidney donor candidates. Furthermore, 230 kidney donors completed questionnaires (eg, on HRQoL) before and 6 and 12 months after donation. PRIMARY AND SECONDARY OUTCOME MEASURES: HRQoL, demographic and preoperative, intraoperative and postoperative health characteristics, perceived support, donor cognitions, recipient functioning and professionals risk estimation questionnaires. RESULTS: On top of other predictors, such as the transplant professionals’ risk assessments, donor self-report measures significantly predicted impaired longer term HRQoL after donation, particularly by poorer predonation physical (17%–28% explained variance) and psychological functioning (23%). CONCLUSIONS: The current study endorses the effectiveness of the psychosocial donor evaluation by professionals and the additional value of donor self-report measures in optimising the psychosocial evaluation. Consequently, systematic screening of donors based on the most prominent risk factors provide ground for tailored interventions for donors at risk

    The communication of a secondary care diagnosis of autoimmune hepatitis to primary care practitioners: a population-based study

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    Background Autoimmune Hepatitis is a chronic liver disease which affects young people and can result in liver failure leading to death or transplantation yet there is a lack of information on the incidence and prevalence of this disease and its natural history in the UK. A means of obtaining this information is via the use of clinical databases formed of electronic primary care records. How reliably the diagnosis is coded in such records is however unknown. The aim of this study therefore was to assess the proportion of consultant hepatologist diagnoses of Autoimmune Hepatitis which were accurately recorded in General Practice computerised records. Methods Our study population were patients with Autoimmune Hepatitis diagnosed by consultant hepatologists in the Queens Medical Centre, Nottingham University Hospitals (UK) between 2004 and 2009. We wrote to the general practitioners of these patients to obtain the percentage of patients who had a valid READ code specific for Autoimmune Hepatitis. Results We examined the electronic records of 51 patients who had biopsy evidence and a possible diagnosis of Autoimmune Hepatitis. Forty two of these patients had a confirmed clinical diagnosis of Autoimmune Hepatitis by a consultant hepatologist: we contacted the General Practitioners of these patients obtaining a response rate of 90.5% (39/42 GPs). 37/39 of these GPs responded with coding information and 89% of these patients (33/37) used Read code J638.00 (Autoimmune Hepatitis) to record a diagnosis. Conclusions The diagnosis of Autoimmune Hepatitis made by a Consultant Hepatologist is accurately communicated to and electronically recorded by primary care in the UK. As a large proportion of cases of Autoimmune Hepatitis are recorded in primary care, this minimises the risk of introducing selection bias and therefore selecting cases using these data will be a valid method of conducting population based studies on Autoimmune Hepatitis

    Perturbed Rotations of a Rigid Body Close to the Lagrange Case under the Action of Unsteady Perturbation Torques

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    Perturbed rotations of a rigid body close to the Lagrange case under the action of perturbation torques slowly varying in time are investigated. Conditions are presented for the possibility of averaging the equations of motion with respect to the nutation angle and the averaged system of equations of motion is obtained. In the case of the rotational motion of the body in the linear-dissipative medium the numerical integration of the averaged system of equations is conducted

    Haemostatic changes in urogenital schistosomiasis haematobium: A case-control study in Gabonese schoolchildren

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    In many tropical areas schistosomiasis is a major health problem causing hepatosplenic, intestinal or urogenital complaints. Hepatosplenic schistosomiasis mansoni is also characterized by blood coagulation abnormalities. Liver pathology plays a role in the development of haemostatic changes and the parasitic infection may directly affect coagulation. However, these contributing factors cannot be studied separately in hepatosplenic schistosomiasis infections. This pilot study provides insight in haemostatic changes in urinary schistosomiasis by studying coagulation parameters in schistosomiasis haematobium-infected Gabonese schoolchildren. Selection on urinary schistosomiasis patients without hepatosplenic complaints allows for the investigation of the direct effects of the parasite on haemostasis. Levels of von Willebrand Factor (VWF) antigen, active VWF and osteoprotegerin were elevated, indicating inflammation-mediated endothelial activation. In contrast to hepatosplenic schistosomiasis, thrombin-antithrombin complex and D-dimer levels were not affected. Despite its small sample size, this study clearly indicates that Schistosoma haematobium directly alters the activation status of the endothelium, without initiation of coagulation
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