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For hydrogen sensor and storage applications, films of Au and Pd were (i) cosputtered at different rates or (ii) deposited in a sequential layer-by-layer fashion on a cover glass. Peculiarities of hydrogen uptake and release were optically monitored using 1.3 µm wavelength light. Increase of optical transmission was observed for hydrogenated Pd-rich films of 10-30 nm thickness. Up to a three times slower hydrogen release took place as compared with the hydrogen uptake. Compositional ratio of Au:Pd and thermal treatment of films provided control over the optical extinction changes and hydrogen uptake/release time constants. Higher uptake and release rates were observed in the annealed Au:Pd films as compared to those deposited at room temperature and were faster for the Au-richer films. Three main parameters relevant for sensors: sensitivity, selectivity, stability (reproducibility) are discussed together with the hydrogenation mechanism in Au:Pd alloys.

Background: Motor estimation error is an index of how accurately one’s body movement is recognized. This study determines whether motor estimation error distance is a Parkinson’s disease (PD)- or age-related disability using a two-step task. Methods: The participants were 19 PD patients and 58 elderly people with disabilities. A two-step prediction test and an actual two-step test were performed. The motor estimation error distance (prediction of two-step distance minus actual two-step distance) and error rate between the two groups were compared. We conducted a correlation analysis between the motor estimation error and clinical factor (e.g., Hoehn and Yahr stage (H & Y), Unified Parkinson’s Disease Rating Scale (UPDRS)) related to PD. Results: The motor estimation error distance was not significantly different between the PD patient group and the elderly group with disabilities. However, significant correlations between motor estimation error and H & Y, and between motor estimation error and UPDRS part II, were observed. The error rate was significantly correlated with the Fall Efficacy Scale. Conclusions: The motor estimation error distance is influenced by both aging and PD.

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The effect of localized damage due to impact on compressive buckling as well as postbuckling behaviors of blade stiffened composite plates was numerically studied. A partial debonding between a skin panel and a flange and multiple delaminations in the skin panel were chosen as the localized damage. The three-dimensional composite elements used to analyze the compressive behavior of the stiffened panel with multiple delaminations was found to be suitable for this kind of complex composite structure. The contact problem between the skin and flange panels was approximated by a spring element with no restraint of the positive relative displacement and a strong restraint of the negative displacement. At the delaminations in the skin panel, which tended to close during compression, the normal relative displacement was constrained to prevent the delaminated portions from overlapping; this constraint made the convergence of the solution quite smooth compared to the case where the contact problem was exactly considered. When a debonded area only was located at the edge of the flange, no notable reduction of compressive buckling load was found until the size of the debonding reached a half wavelength of the buckling mode. The compressive buckling load dropped significantly when multiple delaminations, which were small in comparison to the half wavelength of the buckling mode, accompanied the skin-flange debonding. The energy release rate distributions at the damage edges, calculated using the virtual crack closure technique, increased quite rapidly, particularly in the transverse direction after buckling became sufficient to increase the delamination.