巻号一覧
67 巻, 757 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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菅原 公平1951 年 67 巻 757 号 p. 247-252
発行日: 1951/06/25
公開日: 2011/07/13
ジャーナル フリーGeneral industrial enterprises, having perpetual life, should be valued in accordance with the principle of the present worth of perpetual annuity, and the original capital is not expected to be redeemed. In regard to the mining industry, however, its valuation is done on the principle of the present worth of limitted annuity because of its wasting asset nature, and the capital invested therein should be amortized during its life.
It seems to me that no such fundamental distinction is made in Japan between the two methods of valuation, because the customary valuation formula widely employed at present for ordinary industrial enterprises in our country is nothing else but the mine valuation formula. I would call attention to the necessity of the two valuation methods to be clearly distinguished one from the other and to be applied to proper use, otherwise there would be no sound valuation.抄録全体を表示PDF形式でダウンロード (1402K) -
伊藤 一郎1951 年 67 巻 757 号 p. 253-257
発行日: 1951/06/25
公開日: 2011/07/13
ジャーナル フリーIn this paper the author discusses the effects of non-conductor on the potential curves obtained by the spontaneous polarization method. The problem is dealt as a two-dimentional one, and the non.conductors are supposed to lie near by the polarized orebody.
For some cases the methods for reducing the formulas for the surface potential are given and some numerical calculations are carried out. The results of them are shown in the form of potential profiles.抄録全体を表示PDF形式でダウンロード (970K) -
海底採掘において水災の原因となる各要素についての検討岩澤 栄1951 年 67 巻 757 号 p. 259-262
発行日: 1951/06/25
公開日: 2011/07/13
ジャーナル フリーIn this paper, I will treat on the causes, processes, and countermeasures ef inundation, Ube undersea coal field.
This paper is devided into three parts: First, explanation on the factors causing inundation; second, indication and process of inundation, and third, countermeasures to be taken against inundation.
There are many undersea coal fields in Japan, but because of the differetnt geological structures in each case, the factors composing the causes of inundation vary greatly; moreover due to the lack of fundamental study of such factors, it is very difficult to constrive a general countermeasure. Therefore I here with, for ref ernce's sake, wish to submit my studies based on actual experiences on the above subject.抄録全体を表示PDF形式でダウンロード (987K) -
城 温三1951 年 67 巻 757 号 p. 263-268
発行日: 1951/06/25
公開日: 2011/07/13
ジャーナル フリーThe floatability of flotation solution was studied by the vibrating condenser method and the variation of single electrode potential of Itsudan coal sent from Okinoyama was studied by the vacuum tube potentiometer.
From thes results, the effect of ε-potential on the floatability of coal was cleared out.抄録全体を表示PDF形式でダウンロード (1161K) -
梅津 良之, 島津 敏郎1951 年 67 巻 757 号 p. 269-272
発行日: 1951/06/25
公開日: 2011/07/13
ジャーナル フリーSulphide ores are usually roasted at high temperatures, such as 700°C. or 800°C. In the experiments complex sulphide ores (Kurokô) are roasted under high oxygen pressure in autoclave and leached with with water, 5% H2SO4 and 10% H2SO4 solutions. Good extractions were Obtained, though roasting temperature was exceedingly lower as 300°C. And the reactions of extraction are as follow. Metal Sulphide+3/2O2=SO2+Metal Oxide, SO2+1/2 O2=SO3, Metal Oxide+SO3=Metal Sulphate. And the reactions of roasting under high oxygen pressure finished in short time. For example, the extractions of roasted ores for 15 minites at 300°C. were no difference so much than for 1 hour.抄録全体を表示PDF形式でダウンロード (733K) -
今泉 常正1951 年 67 巻 757 号 p. 273-277
発行日: 1951/06/25
公開日: 2011/07/13
ジャーナル フリーPDF形式でダウンロード (1042K) -
瀬戸 英太郎1951 年 67 巻 757 号 p. 277-278
発行日: 1951/06/25
公開日: 2011/07/13
ジャーナル フリーPDF形式でダウンロード (362K) -
1951 年 67 巻 757 号 p. 279-286
発行日: 1951/06/25
公開日: 2011/07/13
ジャーナル フリーPDF形式でダウンロード (3942K)
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