364 research outputs found

    Adsorption and absorption energies of hydrogen with palladium

    Get PDF
    Thermal recombinative desorption rates of HD on Pd(111) and Pd(332) are reported from transient kinetic experiments performed between 523 and 1023 K. A detailed kinetic model accurately describes the competition between recombination of surface-adsorbed hydrogen and deuterium atoms and their diffusion into the bulk. By fitting the model to observed rates, we derive the dissociative adsorption energies (E0, adsH2 = 0.98 eV; E0, adsD2 = 1.00 eV; E0, adsHD = 0.99 eV) as well as the classical dissociative binding energy ϵads = 1.02 ± 0.03 eV, which provides a benchmark for electronic structure theory. In a similar way, we obtain the classical energy required to move an H or D atom from the surface to the bulk (ϵsb = 0.46 ± 0.01 eV) and the isotope specific energies, E0, sbH = 0.41 eV and E0, sbD = 0.43 eV. Detailed insights into the process of transient bulk diffusion are obtained from kinetic Monte Carlo simulations

    H atom scattering from W(110): A benchmark for molecular dynamics with electronic friction.

    Get PDF
    Molecular dynamics with electronic friction (MDEF) at the level of the local density friction approximation (LDFA) has been applied to describe electronically non-adiabatic energy transfer accompanying H atom collisions with many solid metal surfaces. When implemented with full dimensional potential energy and electron density functions, excellent agreement with experiment is found. Here, we compare the performance of a reduced dimensional MDEF approach involving a simplified description of H atom coupling to phonons to that of full dimensional MDEF calculations known to yield accurate results. Both approaches give remarkably similar results for H atom energy loss distributions with a 300 K W(110) surface. At low surface temperature differences are seen; but, quantities like average energy loss are still accurately reproduced. Both models predict similar conditions under which H atoms that have penetrated into the subsurface regions could be observed in scattering experiments.The authors acknowledge the support of the French Embassy in Cuba, the University of Bordeaux, the CNRS, the Erasmus Mundus programme for funding and ISM and University of Bordeaux for providing computing resources. This work was conducted in the scope of the transborder joint Laboratory QuantumChemPhys: Theoretical Chemistry and Physics at the Quantum Scale (ANR-10-IDEX-03-02). This work was partly performed in the framework of the Elementary Dynamical Processes at Model Catalytic Surfaces (EDPMCS) Experiment, a part of the Molecular Physics at Interfaces Initiative at the Dalian Coherent Light Source. NH, AK and AMW acknowledge support for this project from the Max Planck Society Central Funds, the international partnership program of the Chinese Academy of Science (No. 121421KYSB20170012) as well as the Max Planck Institute for Multidisciplinary Sciences and the Georg-August University of Goettingen. We further acknowledge support from the Deutsche Forschungsgemeinschaft under Grant number 217133147, which is part of the Collaborative research Center 1073 operating Project A04. AK acknowledges European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement no. 833404). OG acknowledges financial support by the Spanish Ministerio de Ciencia e Innovacion [Grant No. PID2019-107396GB-I00/AEI/10.13039/501100011033]

    Immune-Mediated Dermatoses in Patients with Haematological Malignancies: A Comprehensive Review

    Get PDF
    Haematological malignancies induce important alterations of the immune system, which account for the high frequency of autoimmune complications observed in patients. Cutaneous immune-mediated diseases associated with haematological malignancies encompass a heterogeneous group of dermatoses, including, among others, neutrophilic and eosinophilic dermatoses, autoantibody-mediated skin diseases, vasculitis and granulomatous dermatoses. Some of these diseases, such as paraneoplastic pemphigus, are associated with an increased risk of death; others, such as eosinophilic dermatoses of haematological malignancies, run a benign clinical course but portend a significant negative impairment on a patient's quality of life. In rare cases, the skin eruption reflects immunological alterations associated with an unfavourable prognosis of the associated haematological disorder. Therapeutic management of immune-mediated skin diseases in patients with haematological malignancies is often challenging. Systemic corticosteroids and immunosuppressive drugs are considered frontline therapies but may considerably augment the risk of serious infections. Indeed, developing a specific targeted therapeutic approach is of crucial importance for this particularly fragile patient population. This review provides an up-to-date overview on the immune-mediated skin diseases most frequently encountered by patients with onco-haematological disorders, discussing new pathogenic advances and therapeutic options on the horizon

    Thermal Stress Failures : A New Experimental Approach For Prediction and Prevention

    Get PDF
    A new experimental tool for analyzing the topography and deformation of electronics components under thermo-mechanical stress is presented. Application examples are shown for a great variety of components, for localizing and quantifying deformations of electronic assemblies. Cooling and heating cycles following JEDEC type thermal profiles have been applied on different components, both before and after assembly. Simultaneously, real time topography and deformation measurements are obtained. These capabilities constitute a powerful tool for failure prediction, risk evaluation, and accelerated development. The high resolution optical setup allows analysis of deformations in the micrometer range, even for very irregularly shaped surfaces

    Heat Stroke as a Cause of Liver Failure and Evaluation of Liver Transplant

    Get PDF
    Heat stroke is a multiple organ dysfunction syndrome of poorly understood pathogenesis. Exertional heat stroke with acute liver failure is a rarely reported condition. Liver transplant has been recommended as treatment in cases of severe liver dysfunction; however, there are only 5 described cases of long-term survival after this procedure in patients with heat stroke. Here, we present 2 cases of young athletes who developed heat stroke. Both patients developed acute liver failure and were listed for liver transplant. Liver function tests of one patient improved, and he was discharged on postoperative day 13. The other patient showed no signs of improvement and liver biopsy showed massive necrosis. The patient underwent combined kidney-liver transplant and was discharged on postoperative day 17. After a follow-up of longer than 6 years, both patients are doing well with normal liver function and no neurologic sequelae. We also reviewed all published cases of hepatic failure associated with heat stroke and found 9 published cases of liver transplant for heat stroke in the English literature. Conservative management appears to be justified in heat stroke-associated liver failure, even in the presence of accepted criteria for emergency liver transplant
    • …
    corecore