The structures of molten LaCl3 and molten CsCl-NaCl mixtures were studied by Raman spectroscopy. Ionic association in these melts was discussed according to the information of vibrational modes. Complex species of the octahedral type, LaCl63−, was formed in the melt and no association was observed in the molten CsCl-NaCl system.
The porous silicon wafer filled with acid or Nafion was developed as a proton conduction membrane for micro fuel cells. The pores in size of 3-6 μm penetrated through the silicon wafer were prepared by anodic etching with back illumination. When the sulfuric solution or the Nafion solution sank the porous silicon substrate, it was assembled into the H2/air feed fuel cell test section at ambient conditions using conventional electrodes. For the porous wafer filled with sulfuric solution of 10% and 20%, the open circuit voltages (OCV) of 0.932 V and 0.971 V were obtained and the maximum power density of 12.75 mW/cm2 was achieved. For the Nafion filled porous silicon wafer, an OCV of 0.892 V and a maximum power density of 1.27 mW/cm2 were achieved.
Biopsied bovine embryos were evaluated based on oxygen consumption rate, as measured by scanning electrochemical microscopy. The biopsy procedure was found to decrease the oxygen consumption rate of the bovine embryos, and in some cases, caused a marked decrease. Biopsied embryos that showed oxygen consumption rates of above 1.0×10−14 mol·S−1 at 24 h after continuous cultivation exhibited excellent tolerance to the freeze-thawing process. Scanning electrochemical microscopy is considered feasible as a tool for classifying biopsied embryos, and it may facilitate the establishment of a technique for selecting the sex of calves.
A dense La0.9Sr0.1Ga0.8Mg0.2O3–δ (LSGM, 5μm in thickness)/Ce0.8Sm0.2O2–δ (SDC, 400 nm in thickness) bi-layer film was fabricated on a dense NiO (Fe3O4)-SDC anode substrate by a pulsed laser deposition method. After in-situ reduction, the substrate turned to be porous by the reduction of NiO and Fe3O4 to Ni and Fe, and the porosity reached to 13.6 vol%. Stoichiometric composition of LSGM film was successfully prepared by optimizing the deposition parameters and the target composition. When Sm0.6Sr0.4CoO3–δ (SSC) was used as cathode material, extremely high power density was achieved at relatively low temperature. The maximum power density reached to 3270, 1951, 612 and 80 mW/cm2 at 973, 873, 773 and 673 K, respectively. Detail analysis by current interruption method revealed that IR drop was still dominant internal resistance at low temperature and the overpotential of the anode and the cathode was not significant even at 673 K. Therefore, SOFC can be operated at temperature lower than 773 K by using LSGM thin film.
The purpose of this investigation was to study Sn-Ag-Cu alloy electroplating for Pb-free solder from acid sulfate baths (2M H2SO4+0.1 M SnSO4+0.0025 M Ag2SO4+0.002 M CuSO4+0.2 M thiourea) containing N,N-bis(polyoxyethylene)octadecylamine[C18H37N[(CH2CH2O)10H]2:POOA-10] by means of various electrochemical methods, scanning electron microscopic observation, X-ray diffractometry and differential scanning calorimetry. Dendritic electrodeposits were obtained from acid sulfate bath in the absence of organic additives. On the other hand, granular crystals were observed on the whole surface by adding POOA-10. Sn-Ag-Cu alloy electrodeposits containing 3.5~4.2 at% Ag and 1.1~1.8 at% Cu were obtained from acid sulfate baths containing 1 mM POOA- 10 under galvanostatic conditions (1.0~ 5.0 A/dm2). Sn-Ag-Cu alloy electrodeposits obtained from acid sulfate baths containing 1 mM POOA- 10 consist of β-Sn phase, ε(Ag3Sn) phase and η(Cu6Sn5) phase. The solidus temperature of electrodeposit is 217°C and this temperature coincides with the eutectic temperature of casted Sn-3.8 at% Ag-1.4 at%Cu eutectic Alloy.
NASICON (Na3Zr2Si2PO12)-based potentiometric NO2 devices, such as an Au-attached and an (ITO, NaNO2)-attached types, were prepared and their NO2 sensing properties investigated in the range of 1.9 to 6.7 ppm NO2 diluted with air at 30℃.The Au-attached device was found to have a NO2 sensing capability under a humidity condition (30% RH) without any auxiliary phase, although it showed no EMF response under a dry condition (below 1% RH). This experimental result suggests that NO2 sensing reaction of the device is closely related with water vapor. To enhance the NO2 sensitivity of the NASICON-based device, the (ITO, NaNO2)-attached device was therefore fabricated. As the result, the ΔEMF of the (ITO, NaNO2)-attached device was estimated to be 43.6 mV under 30% RH in the range of 1.9- 6.7 ppm NO2, and improved more remarkably in comparison with 17.7 mV of the Au-attached device.
A networked, alternating neodymium-O-phenylene hybrid copolymer was calcined under an argon atmosphere at 400~700°C to obtain black-colored materials. ICP and elemental analyses and XRD measurements showed that the calcined materials were composed of carbon clusters and neodymium oxide particles with diameters of a few nm. ESR spectral measurements showed that the calcined materials have free electrons on carbon clusters. Changes in the ESR signal intensities of the calcined materials with the additions of an oxidant and a reductant showed that an electron transfer from neodymium oxide to carbon clusters took place.
The sterilizing power for the spore of Bacillus cereus was compared between hypochlorous acid and the hypochlorite ion. The ratio between the hypochlorous acid and the hypochlorite ion was increased, and the bactericidal performance for the spore was improved, when the pH of the solution was lowered by adding succinic acid to the sodium hypochlorite solution. To compare the sterilization effect, many samples were tested at peak intensity of the ESR spectrum. In the cases where the ESR spectral peak is low, the sterilizing performance for the spore is high.