High-resolution Ce 3d-edge resonant photoemission study of CeNi_2

Resonant photoemission (RPES) at the Ce 3d -> 4f threshold has been performed for alpha-like compound CeNi_2 with extremely high energy resolution (full width at half maximum < 0.2 eV) to obtain bulk-sensitive 4f spectral weight. The on-resonance spectrum shows a sharp resolution-limited peak near the Fermi energy which can be assigned to the tail of the Kondo resonance. However, the spin-orbit side band around 0.3 eV binding energy corresponding to the f_{7/2} peak is washed out, in contrast to the RPES spectrum at the Ce 3d -> 4f RPES threshold. This is interpreted as due to the different surface sensitivity, and the bulk-sensitive Ce 3d -> 4f RPES spectra are found to be consistent with other electron spectroscopy and low energy properties for alpha-like Ce-transition metal compounds, thus resolves controversy on the interpretation of Ce compound photoemission. The 4f spectral weight over the whole valence band can also be fitted fairly well with the Gunnarsson-Schoenhammer calculation of the single impurity Anderson model, although the detailed features show some dependence on the hybridization band shape and (possibly) Ce 5d emissions.Comment: 4 pages, 3 figur

Photobiocidal-triboelectric nanolayer coating of photosensitizer/silica-alumina for reusable and visible-light-driven antibacterial/antiviral air filters

Outbreaks of airborne pathogens pose a major threat to public health. Here we present a single-step nanocoating process to endow commercial face mask filters with photobiocidal activity, triboelectric filtration capability, and washability. These functions were successfully achieved with a composite nanolayer of silica-alumina (Si-Al) sol-gel, crystal violet (CV) photosensitizer, and hydrophobic electronegative molecules of 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane (PFOTES). The transparent Si-Al matrix strongly immobilized the photosensitizer molecules while dispersing them spatially, thus suppressing self-quenching. During nanolayer formation, PFOTES was anisotropically rearranged on the Si-Al matrix, promoting moisture resistance and triboelectric charging of the Si-Al/PFOTES-CV (SAPC)-coated filter. The SAPC nanolayer stabilized the photoexcited state of the photosensitizer and promoted redox reaction. Compared to pure-photosensitizer-coated filters, the SAPC filter showed substantially higher photobiocidal efficiency (∼99.99 % for bacteria and a virus) and photodurability (∼83 % reduction in bactericidal efficiency for the pure-photosensitizer filter but ∼0.34 % for the SAPC filter after 72 h of light irradiation). Moreover, after five washes with detergent, the SAPC filter maintained its photobiocidal and filtration performance, proving its reusability potential. Therefore, this SAPC nanolayer coating provides a practical strategy for manufacturing an antimicrobial and reusable mask filter for use during the ongoing COVID-19 pandemic

Validating a Cloth Simulator . . .

Tight-fit cloth pressure provides important clue on how well a cloth fits to a body and thus on how comfortable the wearer feels with the cloth. Traditionally-used pressure sensor devices are expensive, sensitive to the experimental environment, and difficult to reproduce. In this paper, a physically-based cloth simulator has been tested for its usability as to measuring the cloth pressure, in order to replace physical measurement of cloth pressure that requires careful operation of pressure sensors. We use existing cloth simulator based on a particle system and measure spring forces exerted on each particle along its normal direction, divided by the summed area of triangles adjacent to that particle. To quantitatively validate the pressure values from the simulator, we have conducted comparative analysis on a set of thin-shell cylindrical tubes − clothing pressure values have been measured by theoretical estimation and physical experiments using pressure sensors, and compared with those measured by the simulation. While their absolute pressure values differ from each other they exhibit a consistent tendency. From these comparative studies we concluded that cloth simulator can actually be used to measure tight-fit cloth pressure, and further conducted the clothing pressure measure on 3D human body models using the simulator

Lotus leaf-inspired droplet-based electricity generator with low-adhesive superhydrophobicity for a wide operational droplet volume range and boosted electricity output

© 2022 Elsevier LtdAs one of the nanogenerators which exploit the potential of the water cycle, a droplet-based electricity generator (DEG) has recently been leading the research field due to its high efficiency. Hence, if the DEG&apos;s effectiveness could be extended to the microscale water cycle, such as raindrop, precipitation, fog, and dew, the application fields of DEG would be countless. While introducing a hydrophobic layer could be a solution to achieving such a wide operational droplet volume range, the hydrophobicity has been so far understood only in terms of increased electricity output of the DEG on the ground that promotes droplet sliding. Herein, we report a lotus leaf-mimicking DEG (simply, LL-DEG) with a low-adhesive superhydrophobic surface of the dielectric layer. The LL-DEG shows not only an increased electricity output with an energy conversion efficiency of 13.7%, but a wide operational droplet volume range to allow normal operation with a droplet volume down to 6 µL. For the first time, we deeply analyze how the lotus leaf-mimicking surface can increase the electricity output of DEG and derive the average rate of droplet contact area change over time by introducing a new parameter, which affects the electricity output. Furthermore, how the lotus leaf-mimicking surface expands the operational droplet volume range is systematically discussed from both the investigations of quasi-static and dynamic states of droplet wetting. The superiority of LL-DEG is confirmed from the demonstration in a rainfall environment including raindrop energy harvesting and self-cleaning property, which is essential for practical utilization in outdoor conditions. Finally, based on the pH-sensitive electricity output, the applicability of the LL-DEG is demonstrated as a raindrop acidity alert. This work, which extends the DEG&apos;s effectiveness to the microscale water cycle, is expected to advance the practical utilization of DEG.11Nsciescopu

Atomistic Simulation of Sintering Mechanism for Copper Nano-Powders

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Material Characterization of Single Crystalline Cu Subjected to High Strain Rates and High Temperatures for Multiscale Simulation

The material characterization of single crystalline Cu columns was numerically carried out at the submicroscopic level. A molecular dynamics (MD) simulation was employed using the embedded-atom method (EAM) interatomic potential between a pair of Cu atoms to describe the interactions among Cu atoms. First, the relationship between mechanical properties and factors affecting their behavior were numerically investigated using a crystal structure including several defects. The factors were specimen size, strain rate, and temperature. As the specimen size increased the normalized yield stress decreased, which was similar to results obtained at other length-scale. The yield stress tended to lead to exponential strain rate-hardening and a linear temperature-softening. Next, material characterization was conducted based on these results. These computational results can lead to the development of an in silico platform to characterize material properties and MD simulation can lay the groundwork for multi-scale modeling and simulation