Crystal quality and optical properties for Nd:GdVO4 single crystals by a floating zone method

Single crystals of neodymium-doped gadolinium orthovanadate (Nd:GdVO₄) were successfully grown by the floating zone method (FZ) with an infrared convergence type heater. These crystal quality and optical properties are sufficient for application to a laser host. Distribution of (Nd/Nd + Gd) concentration by 50 mm in the growth direction was 0.20 ± 0.02 against a target concentration of 0.20. Distribution of extinction ratio at 633 nm by 50 mm in the growth direction was 51 ± 2 dB. Laser performance for these crystals with a-cut were measured. The maximum slope efficiency was 65% and the maximum output power was 3.4 W with continuous wave at 808 nm.     

Somatotopical mapping of the human somatosensory cortex with echo-planar MRI

The somatotopical organization of the somatosensory cortex was analyzed. Echo-planar imaging was used to obtain functional images, and magnetic field strength was 1.5T. Natural stimulation at a frequency of 3 Hz (scrubbing or tapping) was applied to one of the three cutaneous areas: toes, fingertips, and tongue tip. The focal bands which show the significant signal increases were located on the contralateral post-central gyrus, and these changes of signal intensity originate from the cortical parenchyma because there were no major veins in the central sulcus. The focal bands which respond to each stimulation sites were anatomically distinct and located medially-to-laterally in the order of toes, fingertips, and tongue tip.     

Quasi-radial basis functions applied to boundary element solutions for the Grad–Shafranov equation

The Grad–Shafranov equation for axisymmetric fusion plasma has been transformed into a boundary integral equation by expanding the inhomogeneous current density term into a set of ‘quasi’-radial basis functions (RBFs). These quasi-RBFs are derived in such a way that a particular solution for the Grad–Shafranov equation will be a simple Gaussian function. Two or three stages of eigenvalue iterations are required together with a nonlinear optimization to update the scaling factor of each quasi-RBF. It has been found that excellent accuracy of the boundary element solution can be realized with a small number of quasi-RBFs when adopting RBF-dependent scaling factors.     

Characterization and primary structure of a base non-specific and acid ribonuclease from Dictyostelium discoideum

A base non-specific and acid RNase was isolated from cellular slime mold (Dictyostelium discoideum) cells in a homogeneous state (about 2.4 kDa) by SDS-polyacrylamide gel electrophoresis. The RNase (RNase DdI) has a pH optimum of 5.0. The amino acid sequence of RNase DdI was determined by a combination of protein chemistry, a search of Data base, Dicty cDB and further sequence analysis of cDNA from the same bank. RNase DdI consists of 198 amino acid residues, and about 13.3, 0.9, 1.2, 3.3, and 1.0 residues of mannose, xylose, glucose, GlcNAc, and GalNAc, respectively. RNase DdI has two characteristic conserved segments of the RNase T2 family, and thus belongs to the RNase T2 family. Considering the fact that most of the RNase activity of D. discoideum is present in the lysosomal fraction [Wiener and Ashworth (1970) Biochem. J. 118, 505-512], it was concluded that the lysosomal RNase in D. discoideum is a member of the RNase T2 family. The amino acid sequence of RNase DdI is highly homologous with that of Physarum polycephalum RNase (RNase Phyb), and its amino acid sequence seems to be similar to those of plant/animal type RNases, rather than fungal RNases. The location of RNase DdI in the phylogenetic tree of the RNase T2 family was estimated.     

Hyper singular boundary element formulation for the Grad-Shafranov equation as an axisymmetric problem

The Grad-Shafranov equation describes the magnetic flux distribution of plasma in an axisymmetric system such as a tokamak-type nuclear fusion device. This paper presents a scheme to solve the hyper singular boundary integral equation (HBIE) corresponding to this Grad-Shafranov equation. All hyper and strong singularities caused by differentials of the complete elliptic integrals have been regularized up to the level of the Cauchy principal value integral. Test calculations commonly using discontinuous boundary elements have been made to compare the HBIE solutions with the solutions of the standard boundary integral equation (SBIE).     

Flashing characteristics in a pipe downstream from a depressurizing tank and temperature fluctuation characteristics at a mixing tee junction with cold water injection

The flashing characteristics in a pipe downstream from a depressurizing tank were experimentally and analytically investigated on the basis of the transient test and two‐phase flow analysis. The following conclusions were obtained. (1) When the pressure margin of the pump inlet side and the distance to obtain an isothermal condition were sufficient, flashing phenomena did not occur in spite of the decreasing pressure. (2) When the ratio of the cold water injection flow rate to the hot water flow rate M_c/M_h increased, the peak distance of the water temperature fluctuation moved from L/D = 1 to 0, and the maximum water temperature fluctuation ratio was about 40% of the temperature difference between hot and cold water near the mixing tee junction. Because no problem occurred regarding the pipe material thermal fatigue, reliability of the mixing tee junction was assured. (3) Due to suppression of flashing phenomena of the mixing pipe system, the decision diagram on the flashing occurrence was obtained from the test and the analytical results, taking into consideration three factors: the depressurizing ratio in the tank; the cold water injection flow rate due to remaining subcooling; and the delay time of thermal mixing. The simplified analytical equation was used to decrease the cold water injection flow rate by the optimized pipe length between the mixing tee junction and the drain pump. The cold water injection flow rate was minimized when the pipe length was about 15 to 20 times the pipe inner diameter. © 2003 Wiley Periodicals, Inc. Heat Trans Asian Res, 32(5): 411–429, 2003; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.10096     

Non-periodic inspection by Bayesian method I

This paper introduces a Bayesian analysis methodology to determine appropriate non-periodic inspection intervals of fatigue-sensitive structures, so that their reliability remains above a prespecified minimum level throughout their service life. Fatigue damage is considered to initiate in a structural element when cracks develop, whether or not they are detected. The fatigue process then continues by crack propagation, resulting in strength degradation. If a fatigue crack is detected during an inspection, the cracked component is assumed to be repaired or replaced with a new one, resulting in the renewal of its residual strength and fatigue characteristics and increasing thus the overall reliability of the structure. The Bayesian approach introduced in this paper is unique and novel in that it allows one to utilize judiciously the results of earlier inspections for the purpose of determining the time of the next inspection and estimating the values of several parameters involved in the problem that can be treated as uncertain. Numerical simulations verify the above-mentioned capabilities of the Bayesian method.     

Diagnosis of quality of fresh water for carbon steel corrosion by Mahalanobis distance

Corrosion diagnosis of carbon steel in fresh water was carried out by electrochemical method and Mahalanobis-Taguchi (MT) method. The corrosion morphology of carbon steel was classified by the combination of i-E curve measurement and chronopotentiometry. The MT method is one of discriminant analysis and can diagnose distinction data by multiple causes, i.e., ion concentrations. In the present paper, the concept for the application of this method to corrosion diagnosis is introduced. Additionally, electrochemical method was used for specific classification of carbon steel corrosion. By comparing the results of electrochemical measurements with those of Mahalanobis distance, the utility of MT method in the corrosion diagnosis was discussed.     

Chiral separation, determination of absolute configuration, and high-performance liquid chromatography detection of enantiomeric 3-hydroxyhexadecanoyl-CoA

The enoyl-coenzyme A (CoA) hydratase catalyzes the hydration of 2-enoyl-CoA to yield 3-hydroxyacyl-CoA in mitochondrial and peroxisomal β-oxidation. However, the stereospecificities of these hydratases differ from each other. To provide clear evidence of the stereospecificities of hydratases, the absolute configuration of 3-hydroxyhexadecanoyl-CoAs was determined, and they were subjected to a high-performance liquid chromatography (HPLC) using a chiral separation column. The retention time of 3(R)-hydroxyhexadecanoyl-CoA was shorter than that of 3(S)-hydroxyhexadecanoyl-CoA. The HPLC analysis carried out using a chiral separation column is considered to be useful for the study of enoyl-CoA hydratase.