The core facilities of the Wakasa Wan Energy Research Center (WERC) are the multi-purpose 200 MeV synchrotron and 5 MV tandem accelerator. We also have an ion-implanter which provides 10-200 keV high flux ion beam. By using these three accelerators, we have been involved in the development of accelerator technologies, the research on proton therapy, the ion-beam breeding for plants, fungi and bacteria, and the analysis, synthesis, modification, and radiation damage of inorganic materials. We have also performed the ion irradiation experiments on several space equipments, which simulate the effect of space radiation. In this report, our recent research activities using energetic ion beams at WERC will be introduced and the prospects in the near future will be mentioned
Ion beam is used for quantitative element analysis. In the Wakasa Wan Energy Research Center (WERC), various types of ion beam analysis; Particle Induced X-ray Emission (PIXE), Rutherford Backscattering Spectrometry (RBS), and Elastic Recoil Detection Analysis (ERDA), have been performed with a 5 MV tandem accelerator. Recently, in-air and time-of-flight systems have been developed in WERC. The in-air measurement is required often for hydrogen storage materials to determine hydrogen quantity. Hydrogen quantities of magnesium-hydride (MgHx) thin films after production and after hydrogen absorption by magnetron sputtering were measured by the in-air system. The time-of-flight (TOF) ERDA measurement is useful for multi element simultaneous analysis with high depth resolution. The TiO2 thin film of 10 nm thickness has been measured with the TOF ERDA system.
The economic ripple effects of building detached wooden houses using locally sourced wood from Oita Prefecture, Japan, were quantified by an input–output analysis for this evaluation target scenario. In addition, Comparative Scenario 1 (construction using general distribution wood), Comparative Scenario 2 (construction using reinforced concrete), and Comparative Scenario 3 (construction using steel frames) were set for houses built using other construction methods and compared with the evaluation target scenario. The results are as follows. (1) In the evaluation target scenario, production induced a value of 1.65 times the final demand and the gross value added induced a value of 0.79 times the final demand in the prefecture. (2) The sum of the primary indirect effect and the secondary indirect effect of the production-induced value of the evaluated scenarios decreased in the order of wood products, commercial, real estate, transportation, and forestry sectors, thus revealing the impact of the forestry and wood industries on the prefecture. (3) Among all of the scenarios, the production-induced value and gross value added of Comparative Scenario 1 were the lowest. The low self-sufficiency rate in the wood products sector in the prefecture was a causative factor for this result.
Metalation of porphyrins is carried out in the solvents considering the solubility of metal salts and free-base porphyrins. However, the methods using these solvents which have excellent dissolving ability also put at disadvantages such as decreasing reaction rates and yields, and high boiling point of the solvents. In this work, we investigated the Copper(II) metalation of TPP utilizing ionic liquids. The method using [C8mim][Br] provided CuIITPP more effectively with lower amount of solvent than that of using DMSO. A series of studies using multiplicate imidazolium ionic liquids with various structures revealed that the [C8mim][Br] is the most suitable ionic liquids for the Copper(II) metalation of TPP.
Automated identification of surface atoms is very convenient when, for instance, finding atoms that may desorb from a catalyst surface. The proposed algorithm for automated identification is based on the geometry of atom positions and quantifies the solid angle of “open space” around an atom. The solid angle is 2π sr for a prototypical surface atom, while the angle would be larger than 2π sr for a step edge atom, slightly larger than π sr for a surface atom at the foot of a step, and much smaller than π sr for a subsurface atom. The algorithm is expected to accelerate analysis of surface defects of slabs and nanoparticles and contribute to, for example, catalyst design.
An extruded Mg96Zn2Y2 alloy has excellent mechanical properties and a flame-retardant. The alloys have two phases of an Mg matrix and a long-period stacking ordered structure phase (LPSO phase) extended along the extrusion direction. By contrast, the ultrasonic welding technology is a solid-state bonding and the welding is achieved by the severe plastic deformation in the welding processes. However, the dents generated during the welding process are often taken up as issues that affect the weldability. This paper evaluated the relationship between the dent depth and the microstructure in the joints when the welding conditions are kept constant.
After welding, the plastic flow due to the folding phenomenon was observed. When the dent depths became excessive and the sheet thickness reduction rate increased, the LPSO phases extending in the extrusion direction was not maintained. And, the morphology changed into mottled and plate-like LPSO phases. The continuity of the originally LPSO phases was lost, and the plastic deformation progressed during the welding process. It was considered that the heat generated during the process and the severe plastic deformation were the cause. And then, in the joints with the largest sheet thickness reduction rate, a molten structure was formed.
Effects of dual implantation with Ag and Ni ions on the optical absorption of silica glass were investigated. The surface plasmon absorption spectrum after the dual implantation does not correspond to the sum of the spectrum for only Ag ion implantation and that for only Ni ion implantation. The experimental result suggests that morphology and/or the composition of Ag nanoparticles were changed by the subsequent Ni ion implantation. Furthermore, the result of positron annihilation coincidence Doppler broadening profile of Ag and Ni ion implanted sample also shows that the synthesized Ag nanoparticles is affected by the Ni implantation.
Barrier films are key materials not only to preserve foods in fresh from putrefaction, but also to shield electronics devices from oxygen and moisture. A new sensitive method for evaluation of oxygen permeability and biomolecules diffusion coefficients in barrier films is proposed. The principle is to utilize the function of fuel cells, whose output electrical current depends on flow rates of fuel and oxygen to electrodes. By placing barrier films before electrodes, the permeability of barrier films is estimated from the current. In this study, L-ascorbic acid is employed as a model fuel. Diffusion coefficients of fuels in various polymer films have been evaluated, as well as oxygen permeability of a few films.
Fuel cells harvest dissolved oxygen (DO) in water, and can be utilized by same performances to the cell in air within the rated power output. It is also found that fuel cells remove O2 from air and water in closed containers. In deoxidation, several methods, such as direct water supply, bubbling and artificial gill in DO water are studied. The ability of harvesting DO is discussed with relationships between electrical current and O2 flow rate.
In order to predict the potential energy surface (PES) from measured structure in equilibrium state, one should typically perform trial-and-error statistical thermodynamic simulation with assumed multibody interactions. Very recently, we derive map from a set of equilibrium structure in crystalline solids to that of corresponding PES in explicit matrix form, where the PES can be inversely determined from the measured structure. The practical problem to construct the map appears when system size of measured structure is not sufficiently large, which results in non-trivial treatment of asymmetry problem in the map. The present study proposes alternative approach to avoiding treatment of the asymmetry problem, demonstrating more accurate prediction of the PES than the map constructed by explicitly treating the asymmetry.
In order to develop a silicone actuator driven by an electric field in air, the silicone composite films of silicone and polar group-containing material were prepared. The polar group-containing materials were a cyanoethylsucrose containing a cyanoethyl group having a large polarity in its molecule, a side-chain fluoroalkyl-modified silicone oil and a side-chain carboxyl-group-modified silicone oil. The space-charge distribution and the deformation behavior under the electric field of these silicone composite films were measured. Hetero charge accumulation was observed in the silicone composite film in the vicinity of the anode interface, however, no accumulation of hetero charge was observed in the silicone composite film in the vicinity of the cathode. The asymmetry of the space-charge distribution of the silicone/polar group-containing material composite was confirmed. The larger the hetero charge peak value inside the silicone composite film in the vicinity of the anode interface, the larger the deformation. The amount of deformation of the cyanoethylsucrose composite was 280 μm at 3 kV/mm, which was about 20 times as large as that of silicone having no polar group. (silicone composite film size: 168 μm thick, 12 mm long)
We performed complex permittivity measurements for various parts on the flexor surface of wrist by non-invasive dielectric spectroscopy technique using flat-end coaxial electrodes terminated by the tissues with different conditions of bloodstream. The dielectric measurements evaluated dynamic behaviors of ions, water, biomolecules, and various cells including red blood cells in bloodstream with dielectric relaxation processes. The dielectric relaxation curve thus obtained characterized each living tissue and indicated a decreasing tendency of the restoration from the high heart rate and the blood pressure after exercise. Using curve fitting analysis of the relaxation curve with several Cole-Cole functions, one relaxation process was identified as a process reflecting the condition of bloodstream. The present work confirms that the non-invasive dielectric measuring technique using the flat-end coaxial electrode with the fringing electric field quantitatively characterizes the condition of living tissues, and it can be an effective tool for pathology of bloodstream in vivo.
The blood flow of the living body observed by ultrasonic blood flow meter and laser blood flow meter were analyzed whether these results are also reflected in relaxation phenomena obtained from dielectric measurements by impedance analyzer. The interface polarization of red blood cells (RBCs) obtained by dielectric measurements in vivo clearly indicated that the RBC number density increased by sprint. This explanation was confirmed from comparison with the results obtained by ultrasonic blood flow meter and laser blood flow meter. As the blood vessels dilated due to sprint, the amount of blood pumped out increased and RBCs observed by dielectric measurements increased. As the blood volume increased, the mean blood flow velocity was found to be lower than that at rest. The results suggest the blood state in the living body can be obtained by dielectric spectroscopy.