Essential Factors for Shock Compaction of Diamond Composites

Shock compaction experiments for some diamond composites were carried out, and the best consolidated compacts of diamond/SiC and diamond/TiC had relative densities of 95% and 96%, and microhardnesses of 51 ± 2.9 and 48.6 ± 4.8 GPa, respectively. For obtaining better compacts on the shock compaction of mixtures, the ratio of the constituent particle sizes and the properties of the constituent materials are considered, and then the starting conditions of the mixtures must be decided. Here, a simple model concerned with the influence of both the ratio of the constituent particle sizes and the thermal properties of the constituent materials on the shock compaction of mixtures is also presented.     

Estimation of concentrations of antifungal agents allowed as food additives in foods and their daily intake based on official inspection results in Japan in fiscal year 1998

The mean concentrations and daily intake of four antifungal agents were estimated based on the results of an analysis of 7,005 samples of food obtained in official inspections by Japanese local governments in fiscal year 1998. The mean concentration of diphenyl was 0.0004% of the allowable limit, and those of imazalil, o-phenylphenol, and thiabendazole were 14.0%, 3.5%, and 5.7%, respectively. The daily intakes of these antifungal agents per person, estimated from their concentrations and the daily consumption of the foods, were 0.000326, 1.89, 11.5, and 23.3 micrograms, respectively, and assuming a body weight of 50 kg, the amounts of these antifungal agents consumed were 0.000013%, 0.15%, 0.12%, and 0.47% of the acceptable daily intake, respectively. These values are similar to the values obtained on the basis of the results of the official inspection in fiscal years 1994 and 1996, except that the amount of diphenyl is much lower (1/100).     

Characterization of crystalline silicon grown by plasma-enhanced CVD for thin-film solar cells

High growth-rate Si epitaxy by plasma-enhanced chemical vapor deposition (PECVD) has been investigated for a thin-film solar cell application. A high growth rate of 50 μm/h was obtained at 1050°C with plasma which is 50% larger than that by the conventional CVD without plasma. The electrical properties are almost the same for epitaxial layers with and without plasma. For undoped n-type layers, the Hall mobility and carrier density were about 600 cm²/V s and low 10¹⁵ cm⁻³, respectively. The electron diffusion length in doped p-type layers was about 20 μm. These electrical properties for the layer with plasma, in spite of higher growth rate, are comparable or better than those without plasma.     

Ozonation of trichloroethylene in acetic acid solution with soluble and solid humic acid

The combined flushing and oxidation process using acetic acid and ozone has been used successfully to remove trichloroethylene (TCE) completely from contaminated soil. In this study, the effects of humic acid, a fraction of the organic matter in soil, over the performance of TCE decomposition was evaluated. TCE decomposition by ozone was enhanced by the presence of humic acid at concentrations lower than 8mgCL(-1) and then inhibited at higher concentrations. It is possible that the presence of the soluble humic acid fraction during the ozonation of TCE in acetic acid solutions produces hydroxyl radicals during the TCE ozonation which appears to be the reason for the enhanced TCE decomposition rate. Solid humic acid reduced TCE decomposition rate by acting as an ozone scavenger. Similarly, sorbed TCE reduced the amount of TCE available for decomposition by ozone in solution.     

Improvement of the Nelder-Mead method using Direct Inversion in Iterative Subspace

Optimization and Engineering - The Nelder-Mead (NM) method is a popular derivative-free optimization algorithm owing to its fast convergence and robustness. However, it is known that the method...     

Blockchain and smart contract architecture for notaries services under civil law: a Brazilian experience

International Journal of Information Security - This paper proposes a blockchain solution for some activities currently performed by notary offices under the Civil Law judiciary that is technically...     

Direct growth of CdTe on (100), (211), and (111) Si by metalorganic chemical vapor deposition

CdTe epilayers were grown directly on (100), (211), and (111) silicon substrates by metalorganic chemical vapor deposition (MOCVD). The crystallinity and the growth orientation of the CdTe film were dependent on the surface treatment of the Si substrate. The surface treatment consisted of exposure of the Si surface to diethyltelluride (DETe) at temperatures over 600°C prior to CdTe growth. Direct growth of CdTe on (100) Si produced polycrystalline films whereas (lll)B single crystals grew when Si was exposed to DETe prior to CdTe growth. On (211) Si, single crystal films with (133)A orientation was obtained when grown directly; but produced films with (211)A orientation when the Si surface was exposed to DETe. On the other hand, only (lll)A CdTe films were possible on (111) Si, both with and without Te source exposure, although twinning was increased after exposure. The results indicate that the exposure to a Te-source changes the initial growth stage significantly, except for the growth on (111) Si. We propose a model in which a Te atom replaces a Si atom that is bound to two Si atoms.     

Thermal strain of high strength polyethylene fiber in low temperature

High strength polyethylene fiber (Toyobo, Dyneema® fiber: hereinafter abbreviated to DF) has a negative thermal expansion coefficient. Relation between fiber structure and thermal strain of DF used as reinforcement of DF reinforced plastic (DFRP) for cryogenic use was investigated. The crystallinities and orientation angles of several kinds of polyethylene fibers having different modulus from 15 to 134Gpa (herein after abbreviated to DFs) were measured by NMR and X‐ray. We obtained the parameters of the mechanical series‐parallel model composed of crystal and amorphous by crystallinity and modulus. Thermal expansion coefficients of DFs were estimated by mechanical series‐parallel model. All DFs having different modulus showed negative thermal expansion coefficients in the temperature range from 180 to 300K, and absolute values of those markedly increased by increasing tensile modulus of DF. The estimated thermal expansion coefficients showed negative values, and thermal strains showed a similar curve to observed ones mostly. Average thermal expansion coefficients in the temperature range from 180 to 300K estimated by mechanical model agreed with the observed ones. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2918–2925, 2004     

The Anti-Inflammatory Effects of the Methanolic Extract and Fractions from Davilla elliptica St. Hil. (Dilleniaceae) on Bothrops jararaca Envenomation

Inflammation and haemorrhage are the main characteristics of tissue injury in botropic envenomation. Although some studies have shown that anti-venom prevents systemic reactions, it is not efficient in preventing tissue injury at the site of the bite. Therefore, this work was undertaken to investigate the anti-inflammatory effects of the methanolic extract and fractions from D. elliptica and to evaluate the role of matrix metalloproteinases (MMPs) in this process. Effects of the extract and fractions from D. elliptica were evaluated using a carrageenan-induced paw oedema model in rats, and leukocyte rolling was visualized by intravital. The quantification of MMPs activities (MMP-2 and MMP-9) extracted from the dermis of mice treated with extract and fractions alone or incubated with venom was determined by zymographic analyses. Our results show that intraperitoneal (i.p.) injection of fractions significantly reduced paw oedema after the carrageenan challenge. Treatment with the tannins fraction also resulted in considerable inhibition of the rolling of leukocytes and this fraction was able to decrease the activation of MMP-9. These results confirmed the anti-inflammatory activity of the methanolic extract and tannins fraction of D. elliptica and showed that the dermonecrosis properties of B. jararaca venom might be mediated through the inhibition of MMP-9 activity.