Microwave-resonance-induced resistivity: evidence of ultrahot surface-state electrons on liquid 3He

Measurements of the dc resistivity of surface-state electrons on liquid helium exposed to microwave radiation are reported. It is shown that the resonant microwave excitation of surface-state electrons is accompanied by a strong increase in their resistivity, which is opposite to the result expected from the previously used two-level model. We show that even a very small fraction of electrons excited to the first excited state and decaying back due to vapor-atom scattering strongly heat the electron system, causing a population of higher subbands. The calculated resistivity change is in good agreement with the observed data.     

Synthesis of nickel nanoparticles supported on hollow samaria-doped ceria particles via the solution-spray plasma technique: Anode catalysts for SOFCs

Aiming at SOFC anode applications, we have synthesized nanometer-sized nickel catalysts supported on hollow spherical particles of samaria-doped ceria (Ni/SDC) by spraying a mixed solution of nickel, samarium, and cerium nitrates into an atmospheric pressure plasma. The as-prepared particles consisted of SDC (average diameter d_SDC = ca. 0.8 µm) and uniformly dispersed nanometer-sized NiO particles. When reduced in H₂ at 800 °C or 1000 °C, Ni nanoparticles (average diameter d_Ni = 34 nm) were found to be embedded uniformly into the SDC surface.     

Kinetic spectrophotometric determination of tetraphenylporphinecobalt(II) based on photochromism of immobilized norbornadiene

The cobalt(II) complex is detected spectrophotometrically by its catalysis of a photochromic isomerism of norbornadiene (NBD). NBD is immobilized on porous glass beads, and is isomerized to quadricyclane (QC) by UV irradiation. The beads are then immersed in a solution containing tetraphenylporphinecobalt(II) [TPPCo(II)], and the QC is converted back to NBD by a catalytic reaction with TPPCo(II). The rate constant, measured spectrophotometrically, is proportional to the concentration of TPPCo(II). The detection limit of TPPCo(II) is 60 μM for a reaction period of 1 h. This spectrophotometric detection can be applied repetitively without any supply of the chemical reagent, as NBD immobilized on the porous glass beads can be re-isomerized to QC by UV irradiation.     

Influence of extraction process on Cs isotope ratios for Fukushima Daiichi nuclear power plant accident-contaminated soil

Journal of Radioanalytical and Nuclear Chemistry - The influence of extraction process on Cs isotope ratios was investigated by thermal ionization mass spectrometry (TIMS) for nitric-acid (HNO3)...     

Atomic force microscopy study on the stability of a surface film formed on a graphite negative electrode at elevated temperatures

The stability at elevated temperatures of a solid electrolyte interphase (SEI) formed on a graphite negative electrode in lithium ion batteries was investigated by storage tests and in situ atomic force microscopy (AFM) observation. When the fully discharged graphite electrode was stored at elevated temperatures, the irreversible capacity in the following cycle increased remarkably. On the other hand, when the electrode was stored at the fully charged state at elevated temperatures, it was severely self-discharged during storage. AFM observation of the SEI layer formed on a model electrode of highly oriented pyrolytic graphite revealed two important facts on the stability of the SEI at elevated temperatures: (i) dissolution and agglomeration of the SEI layer at the discharged state and (ii) serious SEI growth at the charged state. These phenomena well explain the results of the charge and discharge tests. It was also shown that the addition of vinylene carbonate greatly improves the stability of the SEI at elevated temperatures, and gives good charge and discharge performance after storage.     

Occupational Health Physiotherapy (OHP) Practice: A Comparison between Japan and Australia

Objective: This study aimed to adapt a pre-existing cross-country comparison (CCC) model to Occupational Health Physiotherapy (OHP) practice as a basis for locating and examining contextual factors that may influence OHP practice in Japan and Australia. Method: A secondary analysis was conducted of existing publicly-available data on OHP and related influential factors, following the five components of the CCC model: work-related legislation; labor market characteristics; culture; physiotherapy practice norms; and organization of OHP practice. Results: Legislation in both countries promotes safe work and rehabilitation of work injured/ill workers. 2019 unemployment was lower in Japan with higher employment protection than Australia. Both countries have an ageing workforce and rising retirement age. Cultural differences relate to higher long-term orientation and uncertainty avoidance in Japan. Australia has higher individualism and physiotherapists are autonomous practitioners with direct access, which differs from Japan. Both countries have a national OHP subgroup, to date only Australia has OHP professional practice standards. Discussion: This study is the first to compare OHP practice in Japan and Australia. Contextual similarities and differences observed may underpin OHP practitioner role and its enhancement in work-related musculoskeletal disorder prevention and management strategies, the return-to-work process, and development of this physiotherapy discipline nationally. Conclusion: Adapting the CCC model to OHP practice enabled a structured exploration of resources and data, from which to extract and compare contextual factors that may shape OHP practice in Japan and Australia. This in turn may provide a useful springboard for further discussion about OHP practice internationally.     

The Progress of the Gait Impairment and Brain Activation in a Patient with Post-stroke Hemidystonia

Objective: We explore the effects of body weight-supported (BWS) treadmill training, including the change of cortical activation, on a patient with post-stroke hemidystonia. Patient: The patient was a 71-year-old man with left thalamus hemorrhage. His motor symptoms indicated slight impairment. There was no overactive muscle contraction in the supine, sitting, or standing positions. During his gait, the right initial contact was the forefoot, and his right knee showed an extension thrust pattern. These symptoms suggested that he had post-stroke hemidystonia. Methods: The patient performed BWS treadmill training 14 times over 3 weeks. The effects of the BWS training were assessed by a step-length analysis, electromyography and functional magnetic resonance imaging (fMRI). Results: The patient''s nonparetic step length was extended significantly in the Inter-BWS (p<0.001) and Post-BWS (p=0.025) periods compared to the Pre-BWS session. The excessive muscle activity of the right gastrocnemius medialis in the swing phase was decreased at the Inter-BWS, Post-BWS, and follow-up compared to the Pre-BWS session. The peak timing difference of the bilateral tibialis anterior muscle became significant (p<0.05) on the first day of the intervention. The fMRI revealed that the cortical areas activated by the motor task converged through the intervention (p<0.05, family-wise error corrected). Conclusion: These results suggest that there was improvement of the patient''s symptoms of post-stroke hemidystonia due to changes in the brain activity during voluntary movement after BWS intervention. Body weight-supported treadmill training may thus be an effective treatment for patients with poststroke hemidystonia.     

Extended Hartree—Fock (EHF) theory of chemical reactions VI: hybrid DFT and post-Hartree—Fock approaches for concerted and non-concerted transition structures of the Diels—Alder reaction

Activation barrier heights for concerted and non-concerted transition structures between butadiene and ethylene have been calculated by the broken-symmetry Hartree-Fock (HF), QCISD(T), and CCSD(T) methods with and without approximate spin projection, and the spin-restricted CASCI, CASSCF UNO MP2 and MR MP2 methods. They also have been calculated by the density functional theory (DFT) and hybrid DFT (HDFT) methods such as B2LYP and B3LYP. The reliability and utility of the HDFT methods have been investigated, and compared with the post-HF and MR MP2 results. The information entropy and related electron correlation indices also have been examined in relation to the polyradical character of the transition structures. Implications of the present results are discussed concerning the applicability of HDFT to large systems.     

Relationship between oxide-ion conductivity and dielectric relaxation in the Ln2Zr2O7 system having pyrochore-type compositions (Ln=Yb, Y, Gd, Eu, Sm, Nd, La)

Ln₂Zr₂O₇ (Ln=Yb, Y, Gd, Eu, Sm, Nd, La) system changed from fluorite (F)-type to pyrochlore (P)-type phases when the ionic radius ratios, r(Ln³⁺)/r(Zr⁴⁺), were larger than 1.26. The oxide-ion conductivity showed sharp maximum at the vicinity of the phase boundary between the F- and P-type phases. The frequency dependence of dielectric constant () and dielectric loss factor () were successfully explained by the superimposition of Debye-type polarization due to dopant-vacancy associate and electrode-electrolyte interfacial polarization by the numerical calculation. The peak of dielectric loss tangent (tan δ) was ascribed to the dopant-vacancy associate. The ε_r(0) and dielectric constant of the associate (ε_r0) showed also the maximum values at the vicinity of the phase boundary between the F- and P-type phases.