A leed analysis of the (2×1)H-Ni(110) structure

A monolayer of H atoms adsorbed on Ni(110) below 180 K forms a (2×1) structure. The unit cell exhibits a glide symmetry plane and contains two adsorbed atoms. Based on a quantitative comparison between experimental and calculated LEED I/V spectra using standard R-factors the following structure was derived: On the clean Ni(110) surface the separation between the first two atomic layers, d12, is contracted by 8.5%±1.5% with respect to the bulk value; those between the second and third and the third and fourth layer, d23 and d34, are expanded by 3.5%±1.5% and 1%±1.5%, respectively—in agreement with recent other results. In the presence of the H adlayer the contraction of d12 is reduced to 4.5%±1.5%, while the expansion of d23 is not affected within the limits of accuracy. The third interlayer spacing d34 returns to its bulk value. The H atoms occupy threefold-coordinated sites formed by two Ni atoms from the first layer and one Ni atom from the second layer which confirms previous more qualitative conclusions based on He diffraction and vibrational spectroscopy. The bond lengths between H and its neighbouring Ni atoms were determined to be equal, namely 1.72±0.1 Å

Impact of misinformation and disinformation on the use of research evidence in Africa : disinfodemic and policy in an African context

The results of this research revealed various cases, actors, origin, impact, and mitigation strategies of mis/ disinformation on the use of research evidence. The COVID-19 global pandemic has revealed the danger of mis/ disinformation with numbers of reported studies from west and central Africa demonstrating significant negative impact on evidence informed policymaking and women’s empowerment. “Evidence hesitancy” can be seen in policy makers, practitioners, and citizens alike. In this study, the underlying reasons for evidence hesitancy are analyzed: mis/disinformation; crises; culture; religion; social media. The study identified strengthening policy makers and researcher’s relationships as a way of institutionalizing research evidence for Evidence-Informed Decision Making (EIDM and EIPM, evidence-based policy-making)

When local poverty is more important than your income: Mental health in minorities in inner cities

Volkswagen Foundation and the German Federal Ministry for Education and Research . Grant Number: BMBF 01 EL080

Resonance ionization of sputtered atoms-progress toward a quantitative technique

The combination of RIMS and ion sputtering has been heralded as the ideal means of quantitatively probing the surface of a solid. While several laboratories have demonstrated the extreme sensitivity of combining RIMS with sputtering, less effort has been devoted to the question of accuracy. Using the SARISA instrument developed at Argonne National Laboratory, a number of well-characterized metallic samples have been analyzed. Results from these determinations have been compared with data obtained by several other analytical methods. One significant finding is that impurity measurements down to ppb levels in metal matrices can be made quantitative by employing polycrystalline metal foils as calibration standards. This discovery substantially reduces the effort required for quantitative analysis since a single standard can be used for determining concentrations spanning nine orders of magnitude

Metabolic syndrome severity score: range and associations with cardiovascular risk factors

Introduction: Metabolic Syndrome Severity Score (MSSS) is a new clinical prediction rule (CPR) for diagnostic and therapeutic decisions and employs available components (sex, age, race, systolic blood pressure, waistline circumference, high-density lipoprotein, triglycerides and fasting blood glucose). The aim of our work was to perform cross-sectional pilot trial on middle-aged healthy volunteers and patients with metabolic syndrome (MetS) with and without type 2 diabetes mellitus (T2DM) for studying feasibility and implementation of MSSS and its associations with cardiovascular risk factors.Material and methods: We approached 64 eligible participants from Bulgaria. The MSSS values, together with demographic, anthropometric, medical history, laboratory findings, CVD risk factors, QRISK2 score for 10-year cardiovascular risk and predicted heart age, were analysed. Descriptive statistics with tests for comparison (e.g., t-test, c2) between groups as well as ANOVA and logistic regression were applied. Results: We analysed data from 56 participants (aged 50.11 ±3.43 years). The MSSS was higher in MetS patients (including 6 T2DM patients) than in controls (n = 29; 51.8%) presented as percentiles (69.97% and 34.41%, respectively) and z-scores (0.60 and –0.45, respectively) (p < 0.05). The logistic regression model of MSSS indicated a positive association with MetS/T2DM cases (correctness > 85%, p < 0.01). For further validation purposes, positive correlations of MSSS with CVDrisk factor as diastolic blood pressure (Rho = 0.399; p < 0.003) and QRISK2 score (Rho = 0.524; p < 0.001) or predicted heart age (Rho = 0.368; p < 0.007) were also found.Conclusions: The pilot study of MSSS in Bulgaria indicated feasibility and consistency of its implementation among patients with metabolic syndrome and/or T2DM and healthy volunteers

Oxygen adsorption on the Ru (10 bar 1 0) surface: Anomalous coverage dependence

Oxygen adsorption onto Ru (10 bar 1 0) results in the formation of two ordered overlayers, i.e. a c(2 times 4)-2O and a (2 times 1)pg-2O phase, which were analyzed by low-energy electron diffraction (LEED) and density functional theory (DFT) calculation. In addition, the vibrational properties of these overlayers were studied by high-resolution electron loss spectroscopy. In both phases, oxygen occupies the threefold coordinated hcp site along the densely packed rows on an otherwise unreconstructed surface, i.e. the O atoms are attached to two atoms in the first Ru layer Ru(1) and to one Ru atom in the second layer Ru(2), forming zigzag chains along the troughs. While in the low-coverage c(2 times 4)-O phase, the bond lengths of O to Ru(1) and Ru(2) are 2.08 A and 2.03 A, respectively, corresponding bond lengths in the high-coverage (2 times 1)-2O phase are 2.01 A and 2.04 A (LEED). Although the adsorption energy decreases by 220 meV with O coverage (DFT calculations), we observe experimentally a shortening of the Ru(1)-O bond length with O coverage. This effect could not be reconciled with the present DFT-GGA calculations. The nu(Ru-O) stretch mode is found at 67 meV [c(2 times 4)-2O] and 64 meV [(2 times 1)pg-2O].Comment: 10 pages, figures are available as hardcopies on request by mailing [email protected], submitted to Phys. Rev. B (8. Aug. 97), other related publications can be found at http://www.rz-berlin.mpg.de/th/paper.htm

Structure determination of an adsorbate-induced multilayer reconstruction: (1×2)-H/Ni(110)

The reconstructed (1×2) structure formed by saturation of a Ni(110) surface with adsorbed H atoms at T<180 K was investigated by LEED. Excellent agreement between experimental and calculated I-V spectra for eleven nonequivalent beams was obtained for a model in which parallel rows of Ni atoms in the topmost layer are laterally shifted by 0.3 Å (‘‘row pairing’’) and which exhibits periodic vertical displacements (‘‘buckling’’) of the atoms in the second layer