Measurements of keV-neutron capture cross sections and capture gamma-ray spectra of 105Pd

The neutron capture cross sections and capture gamma-ray spectra of ¹⁰⁵Pd were measured in the region from 15 to 100 keV and at 585 keV. A neutron time-of-flight method was utilised with an anti-Compton NaI(Tl) spectrometer and a 1.5-ns pulsed neutron source by the ⁷Li(p,n)⁷Be reaction. The capture yields were obtained by applying a pulse-height weighting technique to the observed net capture gamma-ray pulse-height spectra. The capture cross sections of ¹⁰⁵Pd were derived with errors less than 5%, using the standard capture cross sections of ¹⁹⁷Au. The evaluated capture cross sections of JENDL-4.0 and ENDF/B-VII.1 were compared with the present results. The evaluations of JENDL-4.0 and ENDF/B-VII.1 were larger than the present results by 3%–15% in the region from 15 to 100 keV and at 585 keV. The capture gamma-ray spectra of ¹⁰⁵Pd were also derived by unfolding the observed net capture gamma-ray pulse-height spectra. The multiplicities of capture gamma rays of ¹⁰⁵Pd were obtained from the capture gamma-ray spectra.     

The effect of the hydrothermal treatment with aqueous NaOH solution on the photocatalytic and photoelectrochemical properties of visible light-responsive TiO2 thin films

The effect of the hydrothermal treatment with aqueous NaOH solution on the photoelectrochemical and photocatalytic properties of visible light-responsive TiO₂ thin films prepared on Ti foil substrate (Vis-TiO₂/Ti) by a radio-frequency magnetron sputtering (RF-MS) deposition method has been investigated. The hydrothermally treated Vis-TiO₂/Ti electrodes exhibited a significant increase in their photocurrent under UV and visible light irradiation as compared to untreated Vis-TiO₂/Ti electrode. SEM investigations revealed that the surface morphology of Vis-TiO₂/Ti are drastically changed from the assembly of the TiO₂ crystallites to the stacking of nanowires with diameters of 30–50 nm with increasing hydrothermal treatment time (3–24 h), accompanying the increase in their surface area. The separate evolution of H₂ and O₂ from water under solar light irradiation was successfully achieved using the Vis-TiO₂/Ti/Pt which is hydrothermally treated for 5 h, while the H₂ evolution ratio was 15 μmol h⁻¹ in the early initial stage, corresponding to a solar energy conversion efficiency of 0.23%.     

Aluminum Triflate as a Powerful Catalyst for Direct Amination of Alcohols,Including Electron‐Withdrawing Group‐Substituted Benzhydrols

Direct aminations of allylic alcohols, benzylic alcohols, and benzhydrols with electron‐withdrawing (F, Br, I, NO₂, or CN) substituents were efficiently catalyzed by aluminum triflate [Al(OTf)₃] to afford the corresponding biarylamines in high yield, and the dibromo‐substituted product was further transformed into letrozole.     

Effect of leakage current through ferroelectric and insulator on retention characteristics of metal-ferroelectric-insulator-semiconductor structure

Abstract

Retention characteristics of MFIS (metal-ferroelectric-insulator-semiconductor) structures have been investigated theoretically and experimentally. The simulated retention characteristics have indicated that reducing current through the ferroelectric layer is very effective to make the retention time long. In order to reduce the current through the ferroelectric layer, an MFIS with an improved ferroelectric layer and an M-I-FIS (metal-insulator-ferroelectric-insulator-semiconductor) have been investigated theoretically. Both of them have given good retention characteristics. Experimentally, retention characteristics of MFIS have been much improved by annealing, which is considered to suppress the current density in the ferroelectric layer, although those of M-I-FIS have been improved a little.     

Development of a separable search-and-rescue robot composed of a mobile robot and a snake robot

Abstract

In this study, we propose a new robot system consisting of a mobile robot and a snake robot. The system works not only as a mobile manipulator but also as a multi-agent system by using the snake robot's ability to separate from the mobile robot. Initially, the snake robot is mounted on the mobile robot in the carrying mode. When an operator uses the snake robot as a manipulator, the robot changes to the manipulator mode. The operator can detach the snake robot from the mobile robot and command the snake robot to conduct lateral rolling motions. In this paper, we present the details of our robot and its performance in the World Robot Summit.     

Measurements of gamma-ray emission probabilities in the decay of americium-244g

ABSTRACT

Accurate data of gamma-ray emission probabilities are frequently needed when one quantitatively determines the amount of isotope by gamma-ray measurements or obtains neutron capture cross-sections using them. Americium-243, one of the most important minor actinides, produces ²⁴⁴Am after neutron capture. The 744-keV gamma-ray decaying from the ground state of ²⁴⁴Am has a relatively large gamma-ray emission probability about 66%; however, its uncertainty is as large as 29%. The uncertainty of the gamma-ray emission probability leads to a major factor of the systematic uncertainty on determining an amount of isotope, and therefore the gamma-ray emission probability was measured by using an activation method and an examined level structure of ²⁴⁴Cm. In this study, the emission probability of 744-keV gamma-ray was derived as 66.5 ± 1.1%, and its uncertainty was improved from 29% to 2%.     

Temperature Dependence of Electrical Condutivity in Polycrystalline Tin Oxide

The electrical conductivity of polycrystalline SnO₂ in air was measured between 400° and 1400°C using samples prepared by hot isostatic pressing and normal sintering. The apparent activation energy for conduction above 800°C was 1.3 to 1.4 eV in the hot isostatically pressed sample and 1.9 to 2.0 eV in the normally sintered sample. This difference can be interpreted as a result of the pore contributing an additional blocking effect to conduction. Also we found that the electrical conductivity above 1150°C bent down slightly from the linear regime when using a cumulative slope model.     

Optimal planning for introducing dispersed generating sources in power systems based on an economical viewpoint

This paper discusses optimal planning problems for dispersed generating sources so as to provide a guideline for their introduction to power systems. First, a recursive method is developed from the viewpoint of supplying electric power only where solutions for one unit are superposed. The computational loads are decreased by selecting alternatives of buses based on the so-called penalty factor. However, for effective utilization of dispersed generating sources, it is indispensable to consider their thermal merits in addition to electric power. After applying the Kuhn-Tucker theory to the optimal dispatching problem including boiler fuel costs, thermal values of the dispersed generating units are evaluated quantitatively. Finally, the above-mentioned technique for the optimal planning basically is also effective and is extended into this case. The validity of the proposed algorithms are demonstrated using a real-scale model system.     

Interaction between opiate subtypes and serotonin in suppressing noxiously evoked activity of WDR neurons

The present study examined interactions between mu and delta opiate subtypes and serotonin. Noxious activity evoked by radiant heat (51 degrees C, 8 sec) was extracellularly recorded from single discriminated wide dynamic range (WDR) neurons in decerebrate spinally transected cats. DAGO (mu selective opioid agonist) 1 microgram or DPDPE (delta selective opioid agonist) 30 micrograms was combined with serotonin (n = 6 each) 250 micrograms. The dose of each drug by itself when administered intrathecally produced no suppression of noxiously evoked activity. Although the combination of DAGO and serotonin produced no significant suppression of noxiously evoked activity, DPDPE and serotonin produced significant suppression to 72.8 +/- 8.0 % (mean +/- SEM) of control values (P < 0.01). Intravenously administered naloxone 0.1 mg reversed the suppression produced by the DPDPE-serotonin combination. Our results suggest that combinations of serotonin and delta selective opiates may be more effective in suppressing noxiously evoked activity than combinations with mu selective opiates.