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Composition- and Size-Dependent Ammonia Electrooxidation Activity of Homogeneously Alloyed PtIr Nanoparticles Prepared by an Ionic Liquid/Metal Sputtering Deposition Technique
No full textHomogeneously alloyed bimetallic PtIr nanoparticles (NPs) were successfully prepared by the simultaneous sputtering of Pt and Ir onto a room-temperature ionic liquid (RTIL) of N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium tetrafluoroborate (DEME-BF4) at room temperature without any additional stabilizing agents. The alloy composition of PtIr NPs was controlled by varying the surface areas of the Pt and Ir plates used as sputtering targets. Catalyst powders (PtIr/CB) were prepared by heating the RTIL containing PtIr NPs with added carbon black (CB) powders. The particle size of PtIr NPs on CB increased from ca. 1.3 to 3.2 nm with an increase in the heating temperature from 100 to 300 °C. Further size enlargement of PtIr NPs was achieved through post-heat treatment of isolated PtIr/CB at 300–500 °C for 1 h. The electrocatalytic activity for the ammonia oxidation reaction (AOR) of PtIr/CB catalysts was significantly influenced by particle size, with optimal activity observed at a size of ca. 2.5 nm. The composition of the PtIr alloy also affected catalytic performance, displaying a volcano-like dependence on the Pt fraction. The highest AOR activity was obtained with ca. 2.5 nm PtIr NPs at a Pt fraction of 73%, showing a specific activity ca. 1.6 times higher than that of pure Pt NPs of similar size.journal articl
SME-sorted hourly mean values of the FPI thermospheric wind and Dynasonde ionospheric velocity in Tromsoe, Norway
No full textFPI thermospheric wind (630nm) and Dynasonde ionospheric ion velocity (F region)datase
宇宙地球環境科学を基盤にした文理融合研究
Get PDF第123回名大カフェ「デジタルアーカイブと旅する和本の宇宙～読んで、さわって、くずし字体験～」(開催日時:2025年11月7日(金)18:00-19:30, 開催地:名古屋大学 Common Nexus) 発表資料名古屋大学宇宙地球環境研究所 融合研究戦略室の融合研究戦略課題「デジタルデータを活用した文理融合研究の可能性検討」の一環として実施conference outpu
Factors associated with intended surrogates’ understanding of end-of-life preferences: a nationwide survey
No full textDesignating a surrogate decision-maker and discussing end-of-life preferences are essential steps to prepare for a potential future loss of decision-making capacity. Yet, little is known about the factors associated with better surrogate understanding of a person’s end-of-life preferences. We aimed to examine which sociodemographic factors, values related to end-of-life care, and decision-making-related factors were associated with perceived surrogate understanding of end-of-life preferences among adults who had designated a surrogate. This cross-sectional study entailed a secondary analysis of data from the Public Awareness of Hospice and Palliative Care Study 2018, a nationwide, web-based survey conducted in Japan. The survey included 1000 adults aged 20–79 who were registered with a market research company. Participants were asked to evaluate the extent to which their designated surrogate understood their end-of-life care preferences. The participants had a mean age of 50.3 years (SD = 15.7), and 51% were female. Among the 873 participants who had designated a surrogate, 57.4% had never discussed their end-of-life preferences with that person. Only 19.9% (n = 174) believed that their surrogate understood their preferences sufficiently. Perceived surrogate understanding was associated with several factors, including age, living status, preferences regarding diagnostic disclosure to family, preferences for end-of-life treatment goals, and the extent of prior end-of-life discussion. The results emphasize the value of end-of-life discussions and the influence of individual characteristics on perceived surrogate understanding.journal articl
Discharge characteristics of a hybrid plasma source using hot cathode arc discharge and helicon wave discharge
No full textHigh-density and large-diameter plasma generation is expected to contribute to semiconductor manufacturing, space propulsion, and nuclear fusion. We develop a plasma generation method for high-density, large-diameter plasma by combining the advantages of both hot cathode arc discharge and helicon wave discharge characteristics. The experiment confirmed that hybrid discharges produce a higher-density plasma compared to standalone arc discharges or helicon wave discharges across a wide range of gas pressures. Additionally, the diameter of the plasma was found to be twice as large as that of arc discharges alone. The mechanisms behind hybrid discharge and potential performance improvements are discussed.journal articl
Decomposition of abrupt transport phenomena in Kelvin–Helmholtz turbulence by using multi-field singular value decomposition
No full textA method of decomposition of abrupt transport phenomena in magnetized plasmas is demonstrated by using a data-driven science method. The set of turbulence data is produced for the Kelvin–Helmholtz turbulence in a cylindrical plasma by using a numerical nonlinear simulation, which is based on an extended Hasegawa–Wakatani model. The obtained turbulence state is accompanied by limit-cycle-like dynamics, and the abrupt particle transport phenomena is observed. We apply a singular value decomposition to the turbulence data with a clustering method, and the turbulence state is decomposed into background, zonal flows, and coherent and incoherent modes. The contribution of these decomposed modes to the particle transport is evaluated for all the combinations of the modes. It is found that the abrupt transport is mainly driven by the incoherent mode, and that it determines the spatio-temporal scale of the abrupt transport for the presented case.journal articl
An electromagnetic shape optimisation for perfectly electric conductors by the time-domain boundary integral equations
No full textThis study proposes a shape optimisation framework for unsteady electromagnetic scattering problems on the basis of the time-domain boundary integral equation method, focusing on the perfectly electric conductors (PECs). The boundary-only formulation is ideal for treating a shape optimisation problem in an exterior domain. However, the electromagnetic shape optimisation in concern has been unrealised with the boundary integral approach regardless of the fact that the boundary-type shape derivative has been known in the literature. The first contribution of the present study is to derive a novel expression of the shape derivative in terms of the surface current densities of the primary and adjoint problems, by considering that the surface current density is handled by usual integral equations methods. The second contribution is to clarify the integral representations and equations of the adjoint electromagnetic fields in terms of the reversal time. These theoretical achievements possess a high affinity with the standard spatial discretising approach (i.e. RWG basis) whenever the temporal basis is sufficiently smooth. The numerical experiments confirmed the reliability of the proposed shape optimisation methodology and indicated the capability to deal with scientific and engineering applications.journal articl