巻号一覧
39 巻 (2012)
- 4 号 p. 121-
- 3 号 p. 94-
- 2 号 p. 41-
- 1 号 p. 2-
39 巻, 4 号
選択された号の論文の8件中1～8を表示しています
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解説
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小川 悦代2012 年 39 巻 4 号 p. 121-129
発行日: 2012/10/25
公開日: 2022/11/20
ジャーナル フリーPolysaccharide gellan gum forms transparent, heat, and acid resistant gels. In the present paper, recent studies on gelation mechanism for gellan gum aqueous solution are reviewed. Using sodium, lithium, potassium, and tetramethyl-type gellan gums as samples, viscometry, osmometry, and differential scanning calorimetry, and light scattering and circular dichroism measurements were carried out in aqueous solutions with and without salts. On lowering temperature, gellan gums undergo a coil to double-helix conformational transition in aqueous solutions with and without salts and a sol to gel transition took place by aggregation of double-helical gellan gum molecules. Attention is especially paid to the effects of molar masses of gellan gum molecules on the coil to double-helix transition and the sol-gel transitions in aqueous solutions. Effects of cations on these transitions of gellan gums in aqueous solutions are also mentioned.抄録全体を表示PDF形式でダウンロード (1409K) -
菅原 透2012 年 39 巻 4 号 p. 130-136
発行日: 2012/10/25
公開日: 2022/11/20
ジャーナル フリーPreviously reported values and properties of enthalpy of fusion of silicate minerals, heat capacity, enthalpy of mixing and entropy of mixing of silicate melts are reviewed. The entropy of fusion of silicate minerals varies linearly with heat capacity of those melts, because both properties reflect configurational freedom of components in silicate melt. Based on the compilation of calorimetric enthalpy measured for melts of mixtures of mineral endmemer compositions, we found that enthalpy of mixing of multi-component silicate melt is controlled by interactions among network-forming oxides (SiO2, NaAlO2, KAlO2), network-modifying oxides (CaO, MgO) and intermediate oxide (CaAl2O4). Entropy of mixing of SiO2-Na2O melt is calculated by a combination of Na2O activity data and calorimetric enthalpy of mixing. The comparison with previous entropy models suggests that a quasi-chemical model and an Adam-Gibbs model overestimate the configurational entropy of mixing of SiO2-Na2O melt.抄録全体を表示PDF形式でダウンロード (503K) -
阿部 陽香2012 年 39 巻 4 号 p. 137-142
発行日: 2012/10/25
公開日: 2022/11/20
ジャーナル フリーIn the National Metrology Institute of Japan (NMIJ), a certified reference material (CRM) for specific heat capacity measurements was produced in accordance with the NMIJ’s quality system which is in compliance with ISO GUIDE 34 and ISO/IEC 17025. A material for the CRM was a single-crystalline silicon. Certified values of specific heat capacity were determined based on the heat capacity obtained by a cryogenic adiabatic calorimeter using a pulse-tube refrigerator in the measurement temperature range from 50 K to 350 K. In this paper, the development of the specific heat capacity CRM is reported in detail.抄録全体を表示PDF形式でダウンロード (651K) -
船橋 正弘, 国岡 正雄2012 年 39 巻 4 号 p. 143-150
発行日: 2012/10/25
公開日: 2022/11/20
ジャーナル フリーEvaluation of biobased content of biobased polymers and their composites by measuring carbon-14 using accelerator mass spectrometry (AMS) was described. Biobased carbon content can be evaluated by measuring carbon-14 content using AMS, since biomass includes carbon-14 atoms in atoms of its constitution and fossil include no carbon-14 atoms in it. Sample preparation and pretreatment for AMS were explained in detail. Results of biobased content of plants, polymers and polymer composites by AMS were shown. Reproducibility and accuracy of AMS measurement were investigated. Evaluation method for biobased polymer content of polymer products can be also obtained using results by AMS. Examples of these evaluation results were shown. The international standards concerning this method were also described.抄録全体を表示PDF形式でダウンロード (503K) -
田中 賢, 佐藤 一博2012 年 39 巻 4 号 p. 151-157
発行日: 2012/10/25
公開日: 2022/11/20
ジャーナル フリーA number of polymeric biomaterials have been proposed, such as hydrophilic, phase-separated, and zwitterionic polymers. Also, new generation polymer: poly(2-methoxyethyl acrylate) (PMEA) shows excellent biocompatibility, and has been approved for medical use. It has not been clearly elucidated which mechanisms are responsible for the biocompatibility on a molecular level, although many theoretical and experimental efforts have been devoted to understand this mechanism. Water interactions have been recognized as a fundamental part of the biological response to contact with biomaterials. We have proposed the “Intermediate water” concept; the water exhibited clearly defined peaks for cold crystallization in the DSC chart. We found that the localized hydration structure consisting of three hydrated water in poly(2-methoxyethyl acrylate) (PMEA). We hypothesized that Intermediate water, which prevents the proteins and blood cells from directly contacting the polymer surface or non-freezing water on the polymer surface, plays an important role in the excellent biocompatibility. Here, I will give an overview of the recent progress in the experimental description of mechanisms of biocompatibility driven by thermal analysis.抄録全体を表示PDF形式でダウンロード (658K) -
津田 健治2012 年 39 巻 4 号 p. 158-163
発行日: 2012/10/25
公開日: 2022/11/20
ジャーナル フリーThe convergent-beam electron diffraction (CBED) technique and its applications to phase transformations are described. Point- and space-group determination, nanometer-scale crystal structure refinement and electrostatic potential analysis using CBED are presented along with examples of the low-temperature ferromagnetic insulator phase of La1-xSrxMnO3 (x = 0.12) and the orbital-ordered phase of FeCr2O4.抄録全体を表示PDF形式でダウンロード (1147K)
技術ノート
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新 大軌, 佐藤 博, 坂井 悦郎, 飯田 真吾2012 年 39 巻 4 号 p. 164-166
発行日: 2012年
公開日: 2022/11/20
ジャーナル フリーA new apparatus, an improved reaction calorimeter was designed and constructed to determine the reaction rate of contact hydration of cement in a short time. The calorimeter consists of twin cells with comb-like agitators in them: a sample cell, wherein hydration reaction takes place, filled with cement and water and a reference cell filled with a reference material. A thermocouple probe is attached at the center of each cell to detect the temperature difference between the cells. The differential output from the thermocouples acts as feedback signal to control the input to an electric heater in the reference cell to compensate the temperature difference between the cells.
Input power to the heater in the reference cell agreed with the calibration heat supplied in the sample cell within 3%. The heat rate curve obtained for contact hydration of Portland cement coincided with that determined by the time differentiation of a reaction thermogram which was obtained using an isoperibol calorimeter and corrected by Newton’s law of cooling.抄録全体を表示PDF形式でダウンロード (304K)
フロギストン
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2012 年 39 巻 4 号 p. 167-169
発行日: 2012/10/25
公開日: 2022/11/20
ジャーナル フリーPDF形式でダウンロード (222K)
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