Aerodynamic aircraft design methods and their notable applications: Survey of the activity in Japan

An overview of aerodynamic aircraft design methods and their recent applications in Japan is presented. A design code which was developed at the National Aerospace Laboratory (NAL) and is in use now is discussed, hence, most of the examples are the result of the collaborative work between heavy industry and the National Aerospace Laboratory. A wide variety of applications in transonic to supersonic flow regimes are presented. Although design of aircraft elements for external flows are the main focus, some of the internal flow applications are also presented. Recent applications of the design code, using the Navier Stokes and Euler equations in the analysis mode, include the design of HOPE (a space vehicle) and Upper Surface Blowing (USB) aircraft configurations

Electroless Deposition of Silver on Multiwalled Carbon Nanotubes Using Iodide Bath

Electroless deposition of silver on multiwalled carbon nanotubes (MWCNTs) was investigated using an iodide bath. Prior to electroless deposition of silver, the MWCNTs were chemically oxidized and then pre-treated using a typical two-step method (sensitization and activation) to form catalytic palladium nuclei on the MWCNTs. Dimethylaminoborane (DMAB) was used to reduce silver ions. Electroless deposition of silver was carried out at 25 degrees C with variation of the pH. The microstructure of the deposits was evaluated using field emission-scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), and transmission electron microscopy (TEM). The silver iodide complex ion species present was determined to be AgI(4)(3-) from equilibrium potential measurements. Silver was selectively deposited on palladium nuclei on the surface of the MWCNTs and continuous diffusion of deposited silver and palladium nuclei resulted in a solid solution of Ag-Pd alloy particles on the MWCNTs at pH = 7.5.ArticleJOURNAL OF THE ELECTROCHEMICAL SOCIETY 158: D506-D510(2011)journal articl

Interatomic potentials for cubic zirconia and yttria-stabilized zirconia optimized by genetic algorithm

Fujii S., Kuwabara A.. Interatomic potentials for cubic zirconia and yttria-stabilized zirconia optimized by genetic algorithm. Computational Materials Science 233, 112722 (2024); https://doi.org/10.1016/j.commatsci.2023.112722.Yttria stabilized zirconia (YSZ) is an important engineering ceramic oxide used for various applications, including solid electrolytes in solid oxide fuel cells due to its high ionic conductivity. Accurate and computationally inexpensive interatomic potentials for cubic ZrO2 and YSZ are required to accommodate the large number of defect configurations originating from high concentrations of Y and oxygen vacancies and to statistically understand their properties in realistic time. In this study, a genetic algorithm has been used to optimize empirical interatomic potential parameters for cubic ZrO2 and 10Y2O3 mol% YSZ using energies, forces acting on atoms, and stresses generated by ab initio calculations as training data. The optimized potentials reproduce the structural, mechanical, and thermal properties as well as the ionic conduction properties more accurately than previously reported empirical interatomic potentials. The developed potentials will be useful for a statistical characterization of YSZ properties, combined with more accurate ab initio calculations

Empirical interatomic potentials for ZrO2 and YSZ polymorphs: Application to a tetragonal ZrO2 grain boundary

Yttria stabilized zirconia (YSZ) ceramics have been used for various engineering applications including structural ceramics, biomedical materials, and thermal barrier coatings. The versatile and excellent properties of YSZ stem from its unique microstructure consisting of monoclinic, tetragonal, and cubic phases, whose stability depends on yttria concentration and temperature. However, there are no empirical interatomic potentials (EIPs) that can reproduce the structures and energies of ZrO2 and YSZ polymorphs, limiting the atomic-scale investigation of lattice defect structures and their interactions that affect the YSZ microstructure and properties. Here, using a genetic algorithm and ab initio training datasets, we have optimized EIPs to sufficiently reproduce the structures and stability of ZrO2 and YSZ polymorphs, as well as the properties of the tetragonal and cubic phases at finite temperature. The potentials have also been applied to the search for a tetragonal grain boundary structure, showing that the obtained grain boundary structure is consistent with that obtained by ab initio calculations. The developed EIPs will aid in revealing the microstructure-property relationships in YSZ by performing large-scale and systematic calculations, which are practically difficult to perform with ab initio and machine-learning-potential calculations.Fujii S., Shimazaki K., Kuwabara A.. Empirical interatomic potentials for ZrO2 and YSZ polymorphs: Application to a tetragonal ZrO2 grain boundary. Acta Materialia 262, 119460 (2024); https://doi.org/10.1016/j.actamat.2023.119460

Comparison of PM10 Pattern and PM2.5 Carbonaceous Fraction from Episodic and Non Episodic Period of Peat Land Wildfire

The peatland wildfire in Indonesia was periodically occurs even in nun ENSO period thus may pose health risk do the inhabitants each year. During non episodic peatland wildfire, we measured PM2.5 using 2 sets of PM2.5 samplers combined with secondary data from fixed monitoring station for ambient PM10. We compare the data with previous Study on episodic wildfire in this peatland area. EC and OC concentrations in PM2.5 were determined using a thermal/optical carbon analyzer with IMPROVE-A protocol. The pattern of PM10 during episodic peatland wildfire can reach more Ethan ten times of PM10 standard (24 h). This is may pose health risk since this high concentration may persist during one month or more. While during non episodic wildfire the ambient PM10 showed moderate fluctuation. During episodic burning period, the ambient atmosphere are enriched by OC1 and OC2 fraction, while in non episodic burning, fraction of OC2, OC3 as well as OC4 shows higher level than OC1. Based on EC ratio analysis the char-EC in biomass burning shows higher than soot-EC leading to dominant fraction of low temperatur elemental carbon originated from biomass burnin

Effect of General Anesthesia on Plasma Ascorbic Acid Level

Ascorbic acid (AsA) and dehydroascorbic acid (DHA) in plasma, and the total vitamin C (AsA + DHA) in urine after oral surgery were measured to investigate whether general anesthesia has effects on the level of plasma AsA. Plasma AsA decreased significantly on the 1st and 3rd post-operative day in the general anesthesia group, but not in the local anesthesia group. A decrease in the AsA level was seen in both the halothane group and the neuroleptanesthesia group. Plasma DHA was not detected pre-operatively, but increased post-operatively and the total vitamin C in the urine decreased on the 1st post-operative day in the general anesthesia group. It was concluded that general anesthesia caused a decrease in the plasma AsA level. This can be only partially explained by the oxidation of AsA. We are going to investigate other causes as the degree of decrease of AsA was larger than the degree of increase of DHA

Complete amino acid sequence of bovine colostrum low-Mr cysteine proteinase inhibitor

AbstractThe complete amino acid sequence of bovine colostrum cysteine proteinase inhibitor was determined by sequencing native inhibitor and peptides obtained by cyanogen bromide degradation, Achromobacter lysylendopeptidase digestion and partial acid hydrolysis of reduced and S-carboxymethylated protein. Achromobacter peptidase digestion was successfully used to isolate two disulfide-containing peptides. The inhibitor consists of 112 amino acids with an Mr of 12787. Two disulfide bonds were established between Cys 66 and Cys 77 and between Cys 90 and Cys 110. A high degree of homology in the sequence was found between the colostrum inhibitor and human γ-trace, human salivary acidic protein and chicken egg-white cystatin

Coronary artery bypass surgery with arterial grafts in familial hypercholesterolemia

AbstractObjective: Familial hypercholesterolemia is a dominantly inherited disorder caused by mutations at the locus for the low-density lipoprotein receptor and is frequently associated with premature coronary artery disease. This study was performed to determine whether arterial grafting was associated with long-term benefits for patients with familial hypercholesterolemia. Methods: During the past 18 years, 101 patients with heterozygous familial hypercholesterolemia underwent primary coronary artery bypass grafting, with one hospital death. Group 1 patients (n = 31) received only saphenous vein grafts. Group 2A patients (n = 47) received one internal thoracic artery graft and supplemental vein grafts, and group 2B patients (n = 23) had multiple arterial grafts. After operation, all patients received diet therapy and intensive cholesterol-lowering drug therapy. Thirteen patients received low-density lipoprotein apheresis. Results: During a mean follow-up period of 95 months, 8 patients died, 9 underwent reoperation, and 12 received catheter intervention. The overall survival was 82% (95% confidence limits, 65%-97%) at 18 years after operation. The survival in group 2 was higher than that found in group 1 (P = .01). The overall freedom from major cardiac events (myocardial infarction, cardiac death, reoperation, and catheter intervention) was 57% (95% confidence limits, 40%-74%) at 16 years after operation. The freedom from reoperation in group 2 was higher than that found in group 1 (P = .03). There was no difference in the survival or freedom from major cardiac events between groups 2A and 2B. Conclusion: Arterial grafting improved the long-term freedom from reoperation in patients with familial hypercholesterolemia. Additional benefit of multiple arterial grafting could not be identified. (J Thorac Cardiovasc Surg 2000;119:1008-14

常温血性心筋保護液による開心術中の心筋保護法に関する研究

取得学位 : 博士（医学）, 学位授与番号 : 医博甲第1137号, 学位授与年月日：平成6年3月25日,学位授与年：199