TEM/STEM Observation of ZrC Coating Layer for Advanced High-Temperature Gas-Cooled Reactor Fuel, Part II

The Japan Atomic Energy Agency (JAEA) has started to study and develop zirconium carbide (ZrC)-coated fuel particles for advanced high-temperature gas-cooled reactors. The ZrC coating layer has been fabricated at JAEA by chemical vapor deposition using a pyrolytic reaction of zirconium bromide. The microstructures of the ZrC layers, whose nominal deposition temperatures could be measured and controlled during the deposition process, were characterized by means of TEM and STEM. In the present study, three batches were prepared and compared with each other as well as the previous batches. The crystallographic orientation of ZrC with regard to the growth direction in the ZrC layers deposited at a constant temperature of 1630 K was different from that deposited at varying temperatures in the 1493–1823 K range. A thin layer of turbostratic carbon was observed at the boundary between pyrolytic carbon and ZrC in particles deposited at the highest temperature among those used in this study (the nominal temperature was 1769 K); no such structure was found in a batch deposited at a lower temperature (the nominal temperature was 1632 K). Therefore, precise control of temperature is shown to be critical to the formation of good ZrC coatings.     

Switched capacitor circuit for 1/f noise generation using a power-law circuit

A simple switched capacitor (SC) circuit is given which realizes a one-dimensional discrete dynamical system X_n+1 = X_n + ux^z generating intermittent chaos with a 1/f-shaped power spectrum. an integrated circuit with a pair of logarithmic and antilogarithmic amplifiters can easily realize the power-law term x^z which plays a key role in generating l/fnoise. an inevitable small offset voltage ? in the SC circuit governs the cut-off frequency of 1/f noise, and when the dynamical system is modified by introducing an effective ?, the ‘indirect method’ enables us to get the precise power spectrum in the modified system.     

Interactive segmentation of the cerebral lobes with fuzzy inference in 3T MR images.

Measurement of volume and surface area of the frontal, parietal, temporal and occipital lobes from magnetic resonance (MR) images shows promise as a method for use in diagnosis of dementia. This article presents a novel computer-aided system for automatically segmenting the cerebral lobes from 3T human brain MR images. Until now, the anatomical definition of cerebral lobes on the cerebral cortex is somewhat vague for use in automatic delineation of boundary lines, and there is no definition of cerebral lobes in the interior of the cerebrum. Therefore, we have developed a new method for defining cerebral lobes on the cerebral cortex and in the interior of the cerebrum. The proposed method determines the boundaries between the lobes by deforming initial surfaces. The initial surfaces are automatically determined based on user-given landmarks. They are smoothed and deformed so that the deforming boundaries run along the hourglass portion of the three-dimensional shape of the cerebrum with fuzzy rule-based active contour and surface models. The cerebrum is divided into the cerebral lobes according to the boundaries determined using this method. The reproducibility of our system with a given subject was assessed by examining the variability of volume and surface area in three healthy subjects, with measurements performed by three beginners and one expert user. The experimental results show that our system segments the cerebral lobes with high reproducibility.     

Analog Circuit Design Methodology in a Low Power RISC Microprocessor

There are various kinds of analog CMOS circuits in microprocessors. IOs, clock distribution circuits including PLL, memories are the main analog circuits. The circuit techniques to achieve low power dissipation combined with high performance in newest prototype chip in the Super H RISC engines are described. A TLB delay can be decreased by using a CAM with a differential amplifier to generate the match signal. The accelerator circuit also helps to speed up the TLB circuit, enabling single-cycle operation. A fabricated 96-mm² test chip with the super H architecture using 0.35-m four metal CMOS technology is capable of 167-MHz operation at 300 Dhrystone MIPS with 2.0-W power dissipation.     

Obstructive jaundice due to multiple hepatic abscesses

A 63-year-old Japanese male with diabetes mellitus developed obstructive jaundice following the onset of multiple hepatic abscesses. Percutaneous transhepatic cholangiography showed intrahepatic bile duct irregularity and dilatations accompanied by a complete obstruction of the right branch of the intrahepatic bile duct. Three kinds of organisms were cultured from the blood and the drained bile. The cholangiographic changes returned to the normal after the liver abscesses subsided following biliary drainage and the administration of intravenous antibiotics.     

Effects of age and sex on sodium chloride sensitivity: association with plasma renin activity

The mechanism by which excessive NaCl intake raises blood pressure has not been fully clarified. The present study was undertaken in 87 Japanese inpatients with essential hypertension to investigate the interrelation among effects of age, sex and the renin-angiotensin system on NaCl sensitivity. After ingesting a regular NaCl diet (170 mmol/day) for one week, subjects were placed sequentially on a week of low NaCl diet (50 mmol/day) and a week of high NaCl diet (340 mmol/day). NaCl sensitivity defined as the difference in mean blood pressure between the low and high NaCl diets did not differ between genders. NaCl sensitivity was positively correlated with age and the change in PRA. The fall in PRA after NaCl loading was significantly smaller in women than in men. By multiple regression analysis, age and the change in PRA independently contributed to the change in mean blood pressure. Furthermore, the interaction between sex and the change in PRA was selected as a statistically significant variable. In conclusion, NaCl sensitivity of blood pressure is independently associated with age and the inadequate suppression of the renin-angiotensin system. Because the contribution of the change in PRA to NaCl sensitivity was greater in women than in men, the mechanism of blood pressure elevation after NaCl loading may differ between genders.     

Autocrine/paracrine role of adrenomedullin in cultured endothelial and mesangial cells

Neuropsychological profiles were assessed in a large group of nondemented control subjects (n = 261) and individuals with dementia of the Alzheimer type (DAT) (n = 407) by subjecting their psychometric test results to a factor analysis. Nondemented control subjects were functionally homogeneous with only one factor accounting for the results. The results of the factor analysis on the very mild DAT and mild DAT groups, however, yielded a mental control/frontal factor, a memory-verbal/temporal factor, and a visuospatial/parietal factor. Forty-one of the original set of participants came to autopsy an average of 5.1 years after psychometric testing and had neurofibrillary tangles, total senile plaques, and cored senile plaques estimated from frontal, temporal, and parietal regions. The results of correlations indicated that the relative burden of cored senile plaques was systematically related to the three psychometric factors. These results suggest a connection between the specific functions as defined by neuropsychological measures and specific neuropathology occurring in associated areas of cortex.     

Evaluation of 9-cis retinoic acid for a new remedy of human retinoblastoma

We investigated the effect of two isomers of retinoic acid (RA), all-trans RA and 9-cis RA, on the proliferation of Y79 human retinoblastoma cells. The two isomers inhibited the cell proliferation in a concentration-dependent manner. The IC50 for this inhibition by all-trans RA and 9-cis RA was 1.50 and 0.15 microM, respectively. The inhibitory effect of 9-cis RA on Y79 cell growth was observed within 24 hr, thereafter the cell number was gradually decreased. In contrast, no inhibition by all-trans RA of Y79 cell growth was observed within 24 hr, thereafter the cell number was slightly increased. In these cases, the cell viability at 4 days after the addition of 9-cis RA and all-trans RA was more than 90% and 95%, respectively. These results indicate that the two RA inhibit the proliferation of Y79 human retinoblastoma cells without inducing the cell death and that the effect of 9-cis RA on the inhibition of Y79 cell growth is much greater than that of all-trans RA.     

Histamine modulates high-voltage-activated calcium channels in neurons dissociated from the rat tuberomammillary nucleus

Insects are known to be useful in estimating the postmortem interval (PMI). Here several cases are reported which show that a wide range of applications in medicolegal questions and hygiene together or apart from estimating the PMI can be answered by use of forensic entomology techniques, including close observation of larval development. Case 1 describes how blowfly larvae fell from a putrefied corpse, hid, and finally emerged from pupae three months after disinfection and renovation. In case 2, the entomological state of the decomposed corpse of a heroin user is described. Case 3 deals with a single adult Protophormia terranovae found in the skull of a partially mummified woman. Case 4 reports the finding of Serratia marcescens bacteria in red Muscina stabulans pupae which were found on a 5-day-old corpse. In case 5, blowfly eggs on the corpse of another heroin user are interpreted as an indication of the decedent being laid outside at night after his death in a flat. Case 6 deals with the finding of Parasarcophaga argyrostoma, which in Cologne might be an indicator species which tells if a corpse was lying outside at least for some time.     

Theory of powdered metal formation in electrochemistry—morphological instability in galvanostatic crystal growth under diffusion control

Following the presentation of the theory of powder formation in steady state electrocrystallization, some equations based on the linear instability theory in non-steady state deposition under diffusion control were derived; the galvanostatic case was then analysed using the theoretical equations obtained here.As a result, the dependences of powder growth and particle size on various physical parameters, such as current density, bulk concentration and temperature, were made quantitatively clear. Furthermore, a reliable basis was given to the induction time of powder formation which had formerly been liable to amibiguous discussion.