Two layer Fluororesin/PU laminated sheets of fluororesin and polyurethane (PU) were prepared by a double-step treatment consisting of applying low dose ≤0.65 MGy homogeneous low energy electron beam irradiation (HLEBI) to the 2-layer assembly where the HLEBI penetrates through the fluororesin and PU layers, respectively, prior to hot-press under 5 MPa and 403 K. Although the adhesion of the Fluororesin/PU sheets cannot be observed without the double-step treatment, bonding forces were created as evidenced by the mean adhesive forces of peeling resistance (oFp). An increasing trend in oFp occurs by the double-step treatment applying HLEBI up to 0.43 MGy, improving the safety level without radiation damage. When HLEBI cuts the chemical bonds and generates dangling bonds with nonbonding electrons in fluororesin and PU, the created adhesion between the laminated sheets can be explained. Based on surface analysis of the Fluororesin/PU laminated sheets after the peeling tests, fluorine was detected on the PU peeled surface, indicating the strong chemical bonding generated by the double-step treatment.
Nuclear fusion device is developed as one of the future energy source. Fuels particles (tritium and deuterium), which don’t react, are exhausted from divertor to the outside of the reactor with a pump. Since tritium is a radioisotope and rarely exists in nature, fuels recovery is necessary. In this study, we have developed a new recover method by hydrogen storage material in the divertor plate. Tungsten is a candidate material for ITER as well as other future magnetic fusion energy devices. The recovery material consists of tungsten which is combined with titanium films as a hydrogen storage material. The titanium films were deposited by ion plating on tungsten substrates. The sample surface temperature was measured by radiation thermometer. After irradiation with deuterium plasma, retention properties of deuterium were examined with thermal desorption spectroscopy (TDS). The experimental results indicated that this method can be applied as a new hydrogen fuel recovery.
We prepared p-type antimony telluride thin films by an oblique deposition at the incident angle ranging from 0º to 80º. We investigated the relationship between the structural and electrical properties of the thin films. As the structural properties, we analyzed cross-section morphology by scanning electron microscope (SEM), and the crystal orientation and crystallite size by x-ray diffraction (XRD) analysis. As the electrical properties, we measured in-plane electrical conductivity, Seebeck coefficient and power factor at room temperature. As a result, we found the thin film at the incident angle of 40° obtained the highest crystal orientation. As the incident angle increased, the crystallite size were enhanced but the power factor decreased. The power factor of thin film at the incident angle of 0° was 1.26 μW / ( cm·K2 ) and thin film at the incident angle of 80° was 0.38 μW / ( cm·K2 ).
We performed experimental and theoretical investigations of structural and thermoelectric properties of Ga-doped ZnO thin films. We prepared the thin films by a RF magnetron sputtering with various argon gas pressures, followed by thermal annealing at 500°C for 60 min in vacuum condition. We evaluated surface morphology and crystallographic properties as the structural properties of the ZnO thin films. To estimate the thermoelectric properties, we performed Hall measurement and the measurements of electrical conductivity, Seebeck coefficient and power factor. For theoretical analysis, we estimated an energy band structure of ZnO by first-principle calculation (ABINIT) based on density function theory with local density approximation, followed by the calculation of transport properties by BoltzTraP code. As a result, we found that the thin films at 2.0 Pa obtained the highest power factor of 0.73 µW/(cm･K²). Even though the transport properties were exhibited certain differences between the experimental results and the theoretical results, we observed the approximate trend of the transport propeties of ZnO.
This paper reports on developing for equivalent circuit models of the impedance change with crack and compositional gradient on oxide ceramic layer. The Electrochemical impedance spectroscopy (EIS) has been used as a tool to in-situ evaluation for properties of oxide ceramic layer exposed to liquid metal at high temperature by equivalent circuit models.
We succeeded in measuring the negative hydrogen ions temperature TH- in the sheet plasma by using an omegatron mass spectrometer. The TH- was determined by measuring the ion current as a function of the ion repeller voltage VG2 using the omegatron mass spectrometer. Calculated using an energy distribution function, TH- was approximately 0.27 eV in the sheet plasma.
We have investigated effectiveness of electroluminescence (EL) measurement as an estimation method for organic-inorganic perovskite solar cells. EL images of CH3NH3PbI3-based solar cells under a constant voltage of 1 V were obtained. We evaluated a relationship between the current density-voltage (J-V) characteristics of the solar cells and these EL images. It was found that EL intensity from our solar cell has a distribution with respect to the position. Because EL intensity indicates correlation with the power conversion efficiency (PCE) of the solar cell, the distribution of EL intensity results from inhomogeneity of properties of material in the cell. These findings mean that an EL measurement is effective for estimation of perovskite solar cells. Moreover, we confirmed effects of applying a voltage during the EL measurement for the solar cell characteristics. By measuring EL for 15 min, decrease of EL intensity with time and decrease of PCE were observed. During the EL measurement with a constant voltage, the applied current density increased continuously. These findings suggest that the resistance of perovskite layer in the solar cell decreases by applying a voltage.