Three-dimensional rainbow schlieren measurements in underexpanded sonic jets from axisymmetric convergent nozzles

The rainbow schlieren deflectometry has been combined with the computed tomography to obtain three-dimensional density fields of shock containing free jets and we call the method the schlieren CT. Experiments on the schlieren CT have been performed at a nozzle pressure ratio of 4.0 by using an axisymmetric convergent nozzle with an inner diameter of 10 mm at the exit where the nozzle was operated at an underexpanded condition. Multidirectional rainbow schlieren pictures of an underexpanded sonic jet can be acquired by rotating the nozzle about its longitudinal axis in equal angular intervals and the three-dimensional density fields are reconstructed by the schlieren CT. The validity of the schlieren CT is verified by a comparison with the density fields reconstructed by the Abel inversion method. As a result, it is found that excellent quantitative agreement is reached between the three-dimensional jet density fields reconstructed from both methods.     

Dummy humanoid robot simulating several trunk postures and abdominal shapes – Report of element technologies

Development of clothing in consideration of the shape and body function of a person with spinal cord injury is an important task. Then, a dummy robot with a deformation mechanism was developed in this study for evaluating the comfortable level of clothings. Specifically, a trunk joint mechanism and an abdominal mechanism that can realize various deformations of the abdominal area and various trunk poses were developed. The trunk joint mechanism was implemented in order to simulate the seated posture of persons with spinal cord injury. The abdominal deformation mechanism was implemented using linear actuators and rotating servomotors in order to simulate abdominal obesity of persons with spinal cord injury. Further, a tactile sensor system was developed for measuring the clothing pressure on the abdominal area and evaluating the comfort or discomfort of clothing.     

Preparation and Intestinal Immunostimulating Activity of Low Molecular Weight Alginate from Saccharina (Laminaria) Species in Japan

We studied the structure of alginates extracted from five commercial Saccharina (Laminaria) species including three varieties (eight samples in all) harvested in Hokkaido, Japan. The algae used were Saccharina japonica, S. japonica var. diabolica, S. japonica var. ochotensis, S. japonica var. religiosa, S. longissima, S. coriacea, S. angustata, and S. sculpera (Kjellmaniella crassiforia). These alginates have molar fractions of mannuronic acid (F_M) ranging from 0.68 to 0.76 and weight average molecular weights (M_ws) ranging from 511,000 to 616,000. Alginate samples from both S. angustata (F_M = 0.76) and S. longissima (F_M = 0.68) showed intestinal immunological activity through Peyer’s patch cells of C3H/HeJ mice. Low molecular weight S. angustata alginate (F_M = 0.75, M_w = 70,000) degraded using a wet pulverizing system showed higher activity than the native one.     

Fundamental Theories on a Combined Energy Cycle of an Electrostatic Induction Hydrogen Electrolytic Cell and Fuel Cell to Produce Fully Sustainable Hydrogen Energy

A hydrogen electrolyzer for decomposition of stable compound H₂O is essentially an electronic device that uses mainly electrostatic‐to‐chemical energy conversion to produce a stoichiometric H₂+O₂ fuel. To achieve a breakthrough in the practical hydrogen electrolytic cell, we demonstrate the electrostatic induction potential superposed electrolyzer. This system operates on a mechanism in which, on a theoretical basis, the power used is 17% of the total electrical energy required, while the remaining 83% can be provided by electrostatic energy free of power. Because H₂O is placed in its decomposition state in the electrostatic field where no current flows, the decomposition voltage is identified as a barrier potential that the electrolytic current must overcome by expending the major part of the total system power. The potential superposition method for supplying energy to the cell was found to avoid the barrier potential effect within the laws of thermodynamics. Combining a fuel cell for producing power from pure H₂ and O₂ in stoichiometric proportions with this type of hydrogen electrolytic cell in a closed energy cycle can achieve a highly positive H₂ balance.     

The Association of Cholesterol Uptake and Synthesis with Histology and Genotype in Cortisol-Producing Adenoma (CPA)

Cortisol-producing adenoma (CPA) is composed of clear and compact cells. Clear cells are lipid abundant, and compact ones lipid poor but associated with higher production of steroid hormones. PRKACA mutation (PRKACA mt) in CPA patients was reported to be associated with more pronounced clinical manifestation of Cushing’s syndrome. In this study, we examined the association of histological features and genotypes with cholesterol uptake receptors and synthetic enzymes in 40 CPA cases, and with the quantitative results obtained by gas chromatography-mass spectrometry (GC-MS) analysis in 33 cases to explore their biological and clinical significance. Both cholesterol uptake receptors and synthetic enzymes were more abundant in compact cells. GC-MS analysis demonstrated that the percentage of compact cells was inversely correlated with the concentrations of cholesterol and cholesterol esters, and positively with the activity of cholesterol biosynthesis from cholesterol esters. In addition, hormone-sensitive lipase (HSL), which catalyzes cholesterol biosynthesis from cholesterol esters, tended to be more abundant in compact cells of PRKACA mt CPAs. These results demonstrated that both cholesterol uptake and biosynthesis were more pronounced in compact cells in CPA. In addition, more pronounced HSL expression in compact cells of PRKACA mt CPA could contribute to their more pronounced clinical manifestation.     

Heat transfer and flow characteristics of flow boiling of CO2‐oil mixtures in horizontal smooth and micro‐fin tubes

Experiments were carried out on the flow pattern, heat transfer, and pressure drop of flow boiling of pure CO₂ and CO₂‐oil mixtures in horizontal smooth and micro‐fin tubes. The smooth tube is a stainless steel tube with an inner diameter of 3.76 mm. The micro‐fin tube is a copper tube with a mean inner diameter of 3.75 mm. The experiments were carried out at mass velocities from 100 to 500 kg/(m²·s), saturation temperature of 10 °C, and the circulation ratio of lubricating oil (PAG) was from 0 to 1.0 mass%. Flow pattern observations mainly showed slug and wavy flow for the smooth tube, but annular flow for the micro‐fin tube. Compared with the flow patterns in the case of pure CO₂, an increase in frequency of slug occurrence in the slug flow region, and a decrease in the quantity of liquid at the top of the tube in the annular flow region were observed in the case of CO₂‐oil mixtures. With pure CO₂, the flow boiling heat transfer was dominated by nucleate boiling in the low vapor quality region, and the heat transfer coefficients for the micro‐fin tube were higher than those of the smooth tube. With CO₂‐oil mixtures, the flow boiling heat transfer was dominated by convective evaporation, especially in the high vapor quality region. In addition, the heat transfer coefficient decreased significantly when the oil circulation ratio was larger than 0.1 mass%. For the pressure drop characteristics, in the case of pure CO₂, the homogeneous flow model agreed with the experimental results within ±30% for the smooth tube. The pressure drops of the micro‐fin tube were 0–70% higher than those predicted with the homogeneous flow model, and the pressure drops increased for the high oil circulation ratio and high vapor quality conditions. The increases in the pressure drops were considered to be due to the increase in the thickness of the oil film and the decrease in the effective flow cross‐sectional area. © 2010 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20287     

用体硅微加工工艺实现的微纳电械系统

1　Ｉｎｔｒｏｄｕｃｔｉｏｎ　　ＭＥＭＳ (ＭｉｃｒｏＥｌｅｃｔｒｏＭｅｃｈａｎｉｃａｌＳｙｓｔｅｍ )ｂａｓｅｄｏｎｓｅｍｉｃｏｎｄｕｃｔｏｒｍｉｃｒｏｆａｂｒｉｃａｔｉｏｎｐｌａｙｓｉｍ ｐｏｒｔａｎｔｒｏｌｅｓｆｏｒｅｘａｍｐｌｅｉｎｔｈｅ ｐｅｒｉｐｈｅｒｙｏｆＩＴｓｙｓｔｅｍｓ.ＮＥＭＳ (ＮａｎｏＥｌｅｃｔｒｏＭｅｃｈａｎｉｃａｌＳｙｓ ｔｅｍ)ｃｏｎｔａｉｎｓｎａｎｏ＿ｓｃａｌｅｓｔｒｕｃｔｕｒｅｓ.Ｓｏｐｈｉｓｔｉｃａｔｅｄａｎｄｈｉｇｈｐｅｒｆｏｒｍａｎｃｅｓｙｓｔｅｍｓｂａｓｅｄｏｎｔｈ…