巻号一覧
38 巻 (1998 - 1999)
- 4 号 p. 220-
- 3 号 p. 139-
- 2 号 p. 47-
- 1 号 p. 1-
38 巻, 1 号
選択された号の論文の4件中1～4を表示しています
- |<
- <
- 1
- >
- >|
-
渡村 信治, 前田 雅喜, 犬飼 恵一, 大橋 文彦, 鈴木 正哉, 芝崎 靖雄1998 年 38 巻 1 号 p. 1-9
発行日: 1998/08/17
公開日: 2011/09/20
ジャーナル フリーTo develop a humidity-control building-material, adsorbed water of four kinds of sepiolite were investigated by the differential thermogravimetory (DTG), differential scanning calorimetory (DSC), and water vapor adsorption and desorption isotherm analysis. Following results were obtained;
1) By the DTG analysis, two dehydration peaks at 30°C and 55°C were observed. The intensity ratio of 55°C/30°C peaks were in the order of the sepiolite from USA (39%)< Turkey (45%)< Spain (50%)< China (67%). The DSC analysis also showed two endothermic peaks at 60°C and 90°C, and the intensity ratio 90°C/60°C were in the order of the sepiolite from USA (37%)< Turkey (43%)< Spain (50%)< China (67%). The amount of the water vapor adsorption at the relative humidity of 90% were in the order of the sepiolite from Turkey (28%)> Spain (24%)=USA (23%)> China (10%).
2) Even after the elimination of the impurity mineral effect on the amount of the water vapor adsorption, significant differences remained in the water vapor adsorption. But the order of the adsorption at P/P0=0.9changed like that of DTG and DSC; the sepiolites from USA (31%)> Turkey (29%)> Spain (25%)> China (20%).
3) Those differences were attributed to the difference in the ratio of micropore to total pore volume, which will be affected by the mean diameter of sepiolite fibers indicated by the crystallite size calculated by a peak width of X-ray diffraction and electron microscopy.
4) Pore size distribution curves calculated by the nitrogen and water vapor adsorption isotherms supported the above estimation.抄録全体を表示PDF形式でダウンロード (3116K) -
石井 卓, 伊藤 雅和, 中島 均, 菅原 宏, 大江 俊昭, 平田 征弥1998 年 38 巻 1 号 p. 10-22
発行日: 1998/08/17
公開日: 2011/09/20
ジャーナル フリーBentonite is adopted as an impervious material for prevention of groundwater from seepage. A focus has been placed upon long-term stability of the bentonite in terms of the impervious capacity. In order to investigate actual conditions of degradation development in natural bentonite layers, field data were taken at three bentonite mines in Japan: Kuroishi, Kawasaki and Dobuyama. Tests were made on all the samples which were extracted from drilled cores of 30-50 m depth. The measurement includes 1) methylene blue capacity, 2) swelling property and 3) exchangeable cation extracted by ammonium acetate solution.
Measures of both the swelling property and concentration of the extracted cations such as Na, K, Ca and Mg were normalized in accordance with measures of the methylene blue capacity, which represent heterogeneity of smectite contents between the samples. A result of the swelling property suggests the degradation spread from the surface toward the depth in the bentonite layers. Degradation regions reached a depth of 10-20 m. While concentration of extracted Na is less in the degradation region than that in a virgin bentonite layer, the concentrations of extracted Ca and Mg are greater. The degradation development in the bentonite layers would be ascribed to ion exchange of Ca and Mg for Na, which are exchangeable cations in smectite, due to the groundwater percolating from surface layers.
On some assumptions of commencement of the degradation in Kuroishi mine, where detailed data was obtained, the development rate is estimated at some 10 mm/1000 years of the degradation in terms of the ion exchange.抄録全体を表示PDF形式でダウンロード (2941K) -
再溶脱処理の効果前田 雅喜, 鈴木 正哉, 大橋 文彦, 渡村 信治, 岡田 清1998 年 38 巻 1 号 p. 23-29
発行日: 1998/08/17
公開日: 2011/09/20
ジャーナル フリーTo develop an effective alkali extraction of amorphous Sio2 from calcined kaolinite for preparation of mesoporous material, repeated selective leaching process was examined. A Chinese kaolinitic clay sample was calcined at 1100°C for lhour. Each 100 g of the calcined samples was suspended in 1N KOH solution (100-500ml) at 90°C for 24hours. The selective leaching treatments were repeated. The mesoporous material obtained from first (solid liquid ratio; 1:1) and second treatment (solid liquid ratio; 1: 5) showed a narrow pore size distribution at around 2.0-3.0nm in pore radius. The specific surface area and total pore volume were 83.2 m2/g and 0.167ml/g, respectively. The water vapor adsorption isotherm showed a rapid increase at about 60%RH. It was found that the mesoporous sample was candidate as humidity self-control material. However, more examination of calcing conditions was required to separate amorphous silica phase and γ-alumina phase completely.抄録全体を表示PDF形式でダウンロード (907K) -
須藤 俊男1998 年 38 巻 1 号 p. 30-39
発行日: 1998/08/17
公開日: 2011/09/20
ジャーナル フリーPDF形式でダウンロード (1311K)
- |<
- <
- 1
- >
- >|