著者

熊谷 誠治 佐々木 恵司 清水 良枝 武田 紘一

出版者

日本素材物性学会

雑誌

素材物性学雑誌 (ISSN:09199853)

巻号頁・発行日

vol.20, no.2, pp.34-38, 2007-12-28 (Released:2010-10-28)

参考文献数

18

被引用文献数

4 4

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Japanese rice husk was converted into an adsorbent for the removal of two types of aldehyde vapors. The rice husks carbonized at 250-800°C in N2 for 1h were exposed to vapors containing 1.0 vol. ppm formaldehyde or 100 vol. ppm acetaldehyde (both N2 carrier) in 5 L-gas sampling bags. Maximum adsorption rates of formaldehyde and acetaldehyde were observed for rice husks carbonized at 800 and 600°C, respectively. The adsorption rates of the aldehydes on the carbonized rice husks were higher than or comparable to those of the commercial granular coconut-shell activated carbon (GCSAC), whereas the specific surface area and the total pore volume of the carbonized rice husks were much lower than that of the GCSAC. The surface basic property of the rice husks carbonized at high temperatures was attributed to the intrinsic inorganic matters of K and Ca, which enhanced an uptake of the aldehydes on their surfaces.

著者

菊池 賢靖 神谷 修 齋藤 省律 熊谷 一男

出版者

日本素材物性学会

雑誌

素材物性学雑誌 (ISSN:09199853)

巻号頁・発行日

vol.11, no.2, pp.12-20, 1998-12-30 (Released:2010-10-28)

参考文献数

9

被引用文献数

5 5

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Beginning of the repeatedly wear, severe wear condition of high wear rate becomes predominate. The wear rate decreases with time and the wear condition changes to a mild wear. After that, a wear becomes hardly advance and becomes stable condition. An oxide film forms at a worn surface and the surface geometry becomes smooth. That condition is called “running-in”. The transition mechanism from severe to “running-in” is important for constant operation of the machine that has a mobile components contacting among metals. A drying repeated wear test of a pin on disk was studied under unlubrication condition in this report. Also, a change of a running-in process in magnetic field has been studied. The results are reported as follows.

著者

中山 勝洋 昌子 智由 牧野 和孝

出版者

日本素材物性学会

雑誌

素材物性学雑誌 (ISSN:09199853)

巻号頁・発行日

vol.15, no.1, pp.8-15, 2002-06-30 (Released:2010-10-28)

参考文献数

5

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The dioxin from the arbage incineration is one of the most serious environmental problems in recent years. There is a method using calcium hydroxide [Ca (OH) 2] as one of the dioxin preventive methods, reacting in the present garbage incineration and removing the chlorine in combustion exhaust gas. The formation mechanism of specific surface in the calcium hydroxide powder generated by reaction from quicklime is not sufficiently elucidated up to now.Calcium hydroxide was thought to decrease specific surface area until now in the case where carboxylic acid is used as an addition in calcium hydroxide reaction.In this paper, the applicability of carboxylic acid to calcium hydroxide reaction, and the morphology formation mechanism of the specific surface of calcium hydroxide is experimentally discussed. As a result, a new triple product factors of the alkyl chain length of the added carboxylic acid, the acidity and the interaction between carboxylic acid and water, were successfully introduced to be reasonably described the experimental result between specific surface area and amount of acid.And, the optimum alkyl chain ength was experimentally pointed out to exist at 5 showing the maximum specific surface area of calcium hydroxide. Also, the increment effect to specific surface area by carboxylic acid addition was shown to be maximum at 0.05 of the amount of carboxylic acid.

著者

成田 章

出版者

日本素材物性学会

雑誌

素材物性学雑誌 (ISSN:09199853)

巻号頁・発行日

vol.11, no.2, pp.102-130, 1998-12-30 (Released:2010-10-28)

参考文献数

82

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The various methods of the non-empirical atomic structure calculations have been so far extensively developed. Their representatives are the Thomas-Fermi, the Hartree, the Hartree-Fock and the density functional methods. These methods have been also applied to the understandings of the physical and the chemical properties for the molecules and the solids. In this review article, mainly the Hartree-Fock and the density functional theories for the atoms are described, and furthermore the methods for the numerical calculations of the basic equations are given. The fundamental physical pictures in the many electron systems are almost included in the HF theory, and the theory is the most standard one in the many body problems even at the present day. The density functional theory is a newer one and originates from the Thomas-Fermi theory, and has merits that the numerical calculations in this method are very easy compared to the HF method and give the similar accuracy to that of the HF method. The studies to improve and to develop the density functional theory are now still continuing. On the other hand, since the relativistic effects are important for the heavier atoms such as the rare earth and the actinide, the fundamentals for the relativistic atomic structure calculations are also given.

著者

大塚 誠 松田 芳久

出版者

日本素材物性学会

雑誌

素材物性学雑誌 (ISSN:09199853)

巻号頁・発行日

vol.4, no.2, pp.128-141, 1991-12-20 (Released:2010-10-28)

参考文献数

25

被引用文献数

1

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Hydroxyapatite (HAP, Ca10 (PO4) 6 (OH) 2), is an important mineral component of hard tissues such as teeth and bones. Therefore, when used in an implanted artificial hard tissue, HAP is expected to show a high affinity for natural hard tissue in situ. However, the bioconvertibility of HAP is affected by the physicochemical properties such as crystallinity, specific surface area, impurities, adsorption and dissolution, depending on the method of synthesis. In this review, the relations between the various kinds of synthesis for HAP and the physicochemical properties are discussed to provide basic information for using biomaterials, and the several application studies about HAP are introduced.