Seismic proof test of a reinforced concrete containment vessel (RCCV): Part 1: Test model and pressure test

In Japan, the Nuclear Power Engineering Corporation (NUPEC), sponsored by the Ministry of Economy, Trade and Industry (METI), has been conducting a series of seismic reliability proving tests using full-scale or close to full-scale models to simulate actual important equipment that is critical for seismic safety of nuclear power plants. The tests are intended to validate the seismic design and reliability with a sufficient margin even under destructive earthquakes. A series of tests was carried out on a reinforced concrete containment vessel (RCCV) for advanced boiling water reactor (ABWR) from 1992 to 1999. A large-scale high-performance shaking table at Tadotsu Engineering Laboratory, the largest in the world, was used for this test. Part 1 reports the test model and the results of pressure and leak tests. Part 2 describes test procedures, input waves and the results of verification tests such as changes of stiffness, characteristic frequency and damping ratio, the failure of the model and the load deflection. Part 3 shows the seismic safety margin that was evaluated from the energy input during the failure test to a design basis earthquake. Part 4 reports simulation analysis results by a stick model with lumped masses.     

Seismic proof test of a reinforced concrete containment vessel (RCCV): Part 2: Results of shaking table tests

A 1/8-scale model was constructed of a reinforced concrete containment vessel (RCCV) used in the latest advanced boiling water reactors (ABWR). Shaking table tests were conducted on it with input motions corresponding to or exceeding a design earthquake assumed for a real Nuclear Power Plant.The objectives of the tests were to verify the structural integrity and the leak-proof functional soundness of the RCCV subjected to design earthquakes, and to determine the ultimate strength and seismic margin by an excitation that led to the model's collapse. The model, the test sequence and the pressure and leak test results were addressed in Part 1. The shaking table test method, the input motions and the test results, including the transition of the model's stiffness, natural frequencies and damping factors and the effects of vertical input motions and internal pressure on the model's characteristics and behavior, the load–deformation, the ultimate strength, the failure mode of the reinforced concrete portion and the liner plate are described here. The seismic safety margin that was evaluated by the energy input during the failure test to a design basis earthquake will be described in Part 3. The analytical results of simulation using the multi-lumped mass model will be described in Part 4.     

Deuterium trapping by irradiation damage in tungsten induced by different displacement processes

The deuterium trapping behaviors in tungsten damaged by light ions with lower energy (10 keV C⁺ and 3 keV He⁺) or a heavy ion with higher energy (2.8 MeV Fe²⁺) were compared by means of TDS to understand the effects of cascade collisions on deuterium retention in tungsten. By light ion irradiation, most of deuterium was trapped by vacancies, whose retention was almost saturated at the damage level of 0.2 dpa. For the heavy ion irradiation, the deuterium trapping by voids was found, indicating that cascade collisions by the heavy ion irradiation would create the voids in tungsten. Most of deuterium trapped by the voids was desorbed in higher temperature region compared to that trapped by vacancies. It was also found that deuterium could accumulate in the voids, resulting in the formation of blisters in tungsten.     

Difference of histology and elemental composition of the cervical enamels among human permanent teeth

The purpose of this study is to clarify the difference of histology and elemental composition of the cervical enamels among the human permanent teeth. The reground surfaces at the cervical enamels of them were observed under scanning electron microscopy (SEM). The contents of seven elements were analyzed quantitatively with electron probe microanalyzer (EPMA). The widths of the rod sections at the cervical enamels were larger than those at the cuspal enamels. The rod sections at the mesial cervical enamels in the incisors were more obscure and more decayed by acid solution than those in the premolars and molars. The calcium and phosphorus contents of the cervical enamels were significantly lower than those of the cuspal enamels. The carbon content of the cervical enamels was significantly higher than that of the cuspal enamels. The calcium and phosphorus contents of the cervical enamels were the significantly highest in the premolars. The carbon and sodium contents of the cervical enamels were significantly highest in the premolars. It is thought that the calcification level is lower, while the content of organic matter is higher at the cervical enamels than those at the cuspal enamels. It is considered that the sodium causes high calcification.     

Cooking up an interactive olfactory game display.

It's long been possible to give users outside an actual environment that environment's visual and auditory information and thus contribute to establishing presence. However, we've yet to establish much presence when users require olfactory information - such as in environments focused on foods, flowers, perfumes, or, in some cases, more offensive smells. Recently, several VR researchers have become interested in olfaction and olfactory displays that present smells in virtual environments (VEs). In this article, we describe our interactive olfactory display. One of our development goals is to confirm the assumption that users' interactions with the system increases presence. Thus, we used our interactive olfactory display to develop a cooking game in collaboration with electronic engineers and artists.     

Development of High Count Rate TES Microcalorimeters

To realize new TES imaging for high energy X-ray or gamma-ray spectrometer with a large pixel array and high count rate, we will try to develop a new radiation absorber self-adjusting the operating temperature and adopting an original reading out method of large pixel array using parallel biasing scheme. Our first prototype TES pixel using Au/Ti/Au tri-layer which consists of the small heat sensors and the radiation absorption area, and these are biased in serial. In this device, the current pulse with the decay time constant of less than 20 microseconds of incident X-rays from ⁵⁵Fe source were observed.      

Methane Oxidation on Perovskite-Type Ca(Mn1−xTix)O3−δ

X-ray photoelectron spectroscopy was performed to elucidate the catalytic activity of CH₄ oxidation on perovskite-type Ca(Mn_{1− x} Ti _x )O_3−δ synthesized at 1173 K in a flow of oxygen from a gel with citric acid and ethylene glycol. The Mn ion content decreases and the ratio of the Mn³⁺ ion in the Mn ion increases with increases in x . Ca(Mn_{1− x} Ti _x )O_3−δ has a high catalytic activity of CH₄ oxidation at x =0.4. These results indicate that the catalytic activity strongly depends on the Mn³⁺ ion content of the surface.     

Radiation induced synthesis of Au-Pd nanoparticles of random alloy structure supported on carbon particles using the high energy electron beam

Au-Pd bimetallic nanoparticles supported on carbon particles were synthesized by reduction of precursor ions in an aqueous solution irradiated with a high energy electron beam. The composition of the samples was analyzed by the inductively coupled plasma atomic emission spectrometry (ICP-AES), and the morphology of the samples was observed by the transmission electron microscope (TEM). TEM micrographs indicated that Au-Pd particles of ca. 5-nm were well dispersed on the surface of carbon particles of ca. 30-nm without any serious agglomeration. Addition of citric acid to the initial solution and high pH were found to be effective for formation of random alloy structure in the resultant bimetallic nanoparticles. The change in the bimetallic structure from core-shell to random alloy was identified by techniques of the X-ray diffraction (XRD) and the extended X-ray absorption fine structure (EXAFS).     

Increased Synovial CD14 mRNA Expression and Proportion of CD14high Subsets in Early-Stage Hip Osteoarthritis: Propensity Matched Score Analysis

The pathophysiology of early-stage hip osteoarthritis (EOA) is not fully understood. Although a previous study in an age-unmatched cohort reported that the number of macrophages was increased in knee EOA compared to late OA (LOA), it remained unclear whether increased macrophages in EOA accurately reflect EOA pathology. We investigated the differences in CD14 expression levels between EOA and LOA using age-unmatched and -matched cohorts. Synovial tissues were obtained from 34 EOA (Tönnis grades 0 and 1) and 80 LOA (Tönnis grades 2 and 3) patients. To correct for differences in demographics between patients with LOA and EOA, we also created propensity score-matched cohorts (16 EOA and 16 LOA). CD14 expression and its association with pain was estimated in LOA and EOA before and after propensity matching. We performed flow cytometry on tissues from the 16 patients, with 8 from each group, to assess for CD14+ subsets in the cells. The CD14 expression in EOA was higher than that in LOA both before and after propensity matching. The proportion of CD14^high subsets in EOA was higher than that in LOA. The CD14 expression was associated with pain in EOA before matching. However, no difference was observed between the pain and CD14 expression after matching in EOA. The increased CD14 expression and the proportion of CD14^high subsets may be important features associated with hip EOA pathology. To accurately compare early and late OA, the analysis of a propensity score-matched cohort is necessary.     

Application of the generalized body-fixed coordinate system for the wave-body interaction problem of a small-depth elastic structure in head seas

The body-fixed coordinate system is applied to the wave-body interaction problem of a small-depth elastic structure which has both rigid and elastic body motion...