The chemical activity of sulphur in liquid lead alloys of Pb-S-X-Y……was measured by means of the reaction, S(in liq. Pb-S-X-Y…)+H_2=H_2S,  K=P_H_2S/P_H_2[s] at 8000 C. Where X, Y,……are added elements such as silver, copper, bismuth and antimony. From this equilibrium, the following relation was found adequate to express the activity coefficient of sulphur in liquid lead alloys: f_S=f_S^X·f_S^Y·…… or =^X+^Y+……where f_S and f_S^X, f_S^Y, …… are the activity coefficients of sulphur in liquid Pb-S-X-Y-…… and Pb-S-X, Pb-S-Y, …… respectively. This equation can be applied to the dilute solution of X, Y, …… in Pb, and its application to solutions of higher concentration is not in good agreement with the experimental results.

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Die Ordnung-Unordnung Umwandlung in der Lennard-Jones und Devonshireschen Theorie des Schmelzens ist näher betrachtet. Obwohl die Molekularanordnung in einer Flüssigkeit analog dem Hypergitter in der Theorie der Legierung behandelt werden kann, ist ihre Theorie, wegen der besonderen Stellung der “Null” Moleküle, quantitativ nicht befriedigend (§2.). Es ist versucht eine modifizierte Theorie zu konstruieren (§3.)

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Physico-chemical properties of ore-forming solution responsible for the formation of Toyoha Pb-Zn vein type deposits, Japan are estimated on the basis of the studies on mineral assemblage and fluid inclusions. The concentration of total dissolved sulfur is estimated in a range from 10^-2 to 10^-3 mol/l which is consistent with that of hot springs accompanying sulfide deposition. The probable ranges of the other variables such as pH, NaCl and base metal contents of ore-forming solution are also calculated. These estimated values are compared with those of hot springs, Broadland geothermal area, New Zealand, now depositing sulfide minerals. It is concluded that both hydrothermal solutions are very similar with respect to physico-chemical properties and both are characterized by (1) total dissolved sulfur in excess over base metals, (2) neutral to slightly alkaline pH, and (3) low NaCl content. These characteristic features are very different from those of Salton Sea geothermal brine which is now depositing sulfide minerals with total dissolved sulfur insufficient for base metals, slightly acid to neutral, and has high NaCl content.

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The information amount obtained through sampling measurement of a dynamic signal is not merely the sum of information amount of each sampling point, because there is a mutual dependency among each point. In this paper, the information obtained per unit time (I₀) is shown as a function of the signal power spectrum (Ω), the sampling frequency (f_s) and the root mean square of measurement errors (σ_n), which is shown in eq. (15), under the assumptions that
(1) the signal is Gaussian,
(2) the measurement errors have a Gaussian distribution and are independent of the signal values. Eq. (15) is derived by calculating the entropies in frequency domain. It is also proved that in the range of f_s «signal bandwidth, I₀ increases by the order of f_s when f_s is increased and in f_s»signal bandwidth, I₀ increases in proportion to log f_s. An example is shown in Fig. 10 and compared with the case of continuous measurement.

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The relation in the chemical composition between coexisting sphalerite and carbonate, which occur together with pyrite, from some hydrothermal vein deposits, was investigated on the basis of the data of both theoretical considerations and electron microprobe analyses. The chemical environment of hydrothermal ore deposition was then discussed. Concentrations of total dissolved sulfur and total dissolved carbon, NaCl-equivalent concentration and pH play an important role as the factors limiting the hydrothermal condition, reflecting the chemical nature of ore-forming solution. Therefore, the relation between the activity of FeS in sphalerite and that of FeCO₃ in carbonate should be considered as a function not only of fugacities of gaseous phases concerned, but also of chemical composition of the ore-forming solution. For refined theoretical considerations, activity-concentration relations for components in the solid phases must be known. The relation between activity and concentration of FeS in sphalerite can be obtained from the recent experimental works in the Zn-Fe-S system. That of carbonate can be approximately obtained on the basis of the experimental work for the CaCO₃-FeCO₃ system by ROSENBERG (1963) and the theoretical study by THOMPSON (1967). Analytical data are plotted on logm'^sp_FeS (m' and sp mean gram formula weight and sphalerite, respectively)-logm'^cb_FeCO3 (cb means carbonate) diagram. In general, the results of the measurements are consistent with the theoretical consideration. Namely, a positive correlation of the logm'^sp_FeS and the logm'^cb_FeCO3 was obtained. Comparing the theoretical consideration with the analytical data obtained, it can be concluded that the fugacity of oxygen gas during ore deposition varies in a very wide range. About eight orders in the range for the fugacity of oxygen gas in logarithmic scale is deduced as a result. This result tells us that the fugacity of oxygen gas could be the most important parameter limiting the physicochemical environment among many parameters. The fugacity of oxygen gas at the time of deposition is increased from the Toyoha (Pb-Zn) thorough the Oe (Mn-Pb-Zn), Inakuraishi (Mn) and Jyokoku (Mn) to the Omori (Au-Ag) vein deposits. The relation may indicate decreasing order of the depth of formation.

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Formation of CO macroblowholes during solidification of Fe-C alloys containing below 0.3%C (mass%) cast into a mold has been studied. The critical compositions for blowhole formation at the carbon concentration of the melt, [%C]_L≤0.3 have been determined by examining 4 types of macroblowhole formation. The critical oxygen concentration for macroblowhole formation is constant at 0.01% in the range of [%C]_L=0.005-0.03, while it decreases as the carbon content increases at [%C]_L =0.05-0.15. It is constant at [%C]_L>0.15. No macroblowholes form at [%C]_L<0.0025. These changes of critical oxygen concentration with carbon concentration have been explained by the changes of microstructures, which correspond to the morphologies of solidification interface. The mechanism of macroblowhole formation has been explained by the fact that microporosities formed in the interdendritic region grows into macroblowholes. Especially the critical composition for blowhole formation at 0.1%C has been explained quantitatively by the calculation of the model. It is found that there is agreement between the calculated and the experimental results of the critical composition.

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Thermal cycle tests for solder joints of electronic devices are generally performed to investigate their reliability under field service (design) conditions. It is important to clear a relationship between an accelerated test condition and a service condition and to determine a practical accelerated test condition. The relationship between an accelerated test condition and a service condition is explained by use of the solder joint fatigue curve. An accelerated reliability test condition is shown taking account of several factors such as a number of test samples, strain ranges of solder joints under accelerated test temperatures conditions, standard variations of fatigue life of solder joints, reliability and confidence level of devices under service conditions. Moreover, the cases that the standard deviation of fatigue life is known or unknown are investigated. A specific analytical and experimental result for single outline packages is shown.

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The stratabound-type sulfide deposits in Japan are divided into two types; the Besshi-type deposit and the Kuroko-type deposit, on the basis of their geological and mineralogical aspects and isotopic characteristics.
The “Kuroko” deposit is a polymetallic sulfide-sulfate deposit genetically related to submarine calc-alkaline acid volcanic activity of Neogene Tertiary. All of the Kuroko deposits occur in the so-called Green Tuff region. The nature of deposits changes downward from the stratiform deposit to the disseminated and/or the stockwork deposits. Meanwhile, the Kuroko deposit can be generally divided into the following four zones according to the mineral assemblage of ores; Quartz-hematite zone, Kuroko (black ore) zone, Ôko (yellow ore) zone, and Keiko (siliceous ore) zone in stratigraphically descending order. The main hypogene minerals constituting the sulfide ore are pyrite, chalcopyrite, sphalerite, galena, minerals of tetrahedrite group, marcasite, bornite in decreasing order with quartz and barite as gangue minerals. Gypsum-anhydrite ores are well developed in the Kuroko deposit closely associated with sulfide ores.
Besshi-type deposit, that is to say, the bedded cupriferous iron-sulfide deposit, is well known in the Sambagawa metamorphic belt, and the deposits of allied type occur in the non-metamorphic Palaeozoic terrains and in the Shimanto belt. Besshi-type deposit is usually associated with submarine basic volcanic materials, and are modified by later metamorphism and deformation. The ore minerals consist chiefly of pyrite, chalcopyrite, sphalerite and of less amount of bornite. A negligible amount of galena is one of the most significant features of ore. Magnetite or hematite layers occassionally interbedded in the cupriferous pyrite layers, are worthy of notice of the connection with the fugacities of S₂ and O₂ during ore deposition.
Taro deposit, Kuroko-type deposit of the early Cretaceous age, occurs in the Taro belt of northeast Japan, being genetically related to submarine calcalkaline acid volcanic activity. The sulfide minerals consist chiefly of pyrite, chalcopyrite, sphalerite, and galena. Barite is rather less in amount than that in the Neogene Kuroko deposit. Small lenticular masses consisting of gypsum and calcite is poorly deleloped below the stratiform sulfide deposit. The ore deposit is comparatively monotonous in mineral assemblages, and variety of minerals is far less than that in the Kuroko deposit. However, alabandite occurring in the hanging wall side is noteworthy for studing the physico-chemical condition of ore deposition.
In this paper, all of the minerals from the above-mentioned deposits are listed up, and some of them are described about their chemical compositions, and also mineral assemblages, in order to offer useful information on the investigation of physico-chemical environments of ore formation. Moreover, the texture and structure of ores from the deposits are briefly summarized.

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Sulphur distribution ratios have been determined between carbon-saturated iron and Na₂O-SiO₂, Na₂O-SiO₂-CaO and Na₂O-SiO₂-CaO-CaF₂ slags at 1350°C. The experiments were performed in graphite crucibles under a carbon monoxide atmosphere. Sulphide capacities were calculated based on the sulphur distribution ratios. Additions of Na₂O increase the sulphide capacity of silicate as well as lime-based slags significantly and the Na₂O-equivalent of CaO was determined as 0.30. CaO-Na₂O-SiO₂-CaF₂ slags possess high sulphide capacities as well as low melting points, and can consequently be utilized for hot-metal treatment at relatively low temperatures. However, additions of CaF₂ decrease the sulphide capacity of these slags and consequently only enough CaF₂ should be used to ensure that the slags remain liquid during the desulphurization treatment.

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To determine the thermodynamic properties of sulphur dissolved in liquid iron, the equilibrium in the reaction S+H₂ (g)=H₂S (g)
was investigated for the temperature range of 1550-1700°C and sulphur concentration up to about 2 pct., using an induction furnace.
Though these measurements have been done by many investigators, their results have scattered by such reasons as sulphur segregation in specimens and thermal diffusion of gas mixture.
After the improvement for these many problems to be solved, the following equilibrium relation was obtained.
log K (=p_H2S/p_H2·a_s) =-3200/T-0.863
The activity coefficient of sulphur in molten iron, that is f_s, decreased with the increase in sulphur concentration, however its decreasing rate became smaller with increasing temperature, indicating that iron-sulphur solution had a tendency to approach on ideal state with increasing temperature.
The relationship among f_s, sulphur concentration and temperature was given as follows, log f_s=(-286/T+0.119)[%S].

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Forming conditions and compositional changes of primary inclusions in molten steel have been studied due to the demand for high cleanliness of steels. MnS, a common inclusion in steel, does not form in molten steel, although it is observed in steel with oxide inclusions such as MnO, Al₂O₃ and SiO₂. On the other hand, Mn and S are enriched in molten steel due to the segregation phenomenon during the solidification process which suggests that MnS form in molten steel during solidification. However, the precipitation behavior of MnS inclusions in molten steel due to the enrichment of Mn and S and the interaction between the primary inclusion and the molten steel is still unclear. In this work, a new experimental technique was developed and the precipitation behavior of MnS from molten steel onto solid Al₂O₃ was studied. Solid MnS precipitates were observed on the Al₂O₃ rod immersed in the sample with adding Al whereas precipitates containing MnO, A₂O₃ and MnS were observed on the Al₂O₃ rod in the sample without adding Al. Thermodynamic analysis revealed that Mn enriched in molten steel is oxidized to form MnAl₂O₄ when Al content is low and the MnAl₂O₄ reacts with S in molten iron to form molten MnO–Al₂O₃–MnS. MnS can precipitate from the molten MnO–Al₂O₃–MnS. On the other hand, Mn enriched in molten steel does not react with Al₂O₃ when Al content is high. Therefore, MnS can precipitate at the final period of solidification where Mn and S are significantly enriched in molten steel.

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三軸スライスせん断試験装置を用いて, 一定の初期せん断応力が作用したせん断破壊前の状態において飽和正規圧密粘土供試体の間隙水圧を増加させる試験を実施し, この過程における粘土の膨潤特性とせん断特性を検討した. その結果, 間隙水圧の増加に伴い, すべり面のせん断応力と有効垂直応力の関係は限界状態線上で定常状態に達しせん断ひずみが急増し累積すること, すべり面で稼動されるせん断弓鍍は限界状態線に沿って減少することを明らかにした. また, 間隙水圧の増加に伴う間隙比増加量と正規化した有効垂直応力およびせん断強度の関係はいずれも膨潤指数によって一義的に定まることを見出した. さらに, 初生地すべり斜面の安全率がすべり面における間隙水圧増加量もしくは間隙比増加量によって概略評価できることを示した.

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The change in entropy upon fusion Was considered based on simplified atomic models of solids and liquids and found that it consists of three parts, these were attributed to the change in static potential energy accompanied by the voluminal expansion, the decrement of the interatomic frequency and the disappearance of the long range order in liquid phase respectively. From this point of view, theories of Eyring Grüneisen and Mott were criticized

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Aesthetic shapes are usually actualized as 3D objects represented by free-form surfaces. The main components used to achieve aesthetic surfaces are 2D and 3D curves, which are the elements most basic for determining the shapes and silhouettes of industrial products. Bézier, B-Spline and NURBS are types of flexible curves developed for various design intents. These curves, however produce complex curvature functions that may undermine the formulation of shape aesthetics. A viable solution to this problem is to formulate aesthetic curves and surfaces from well-defined curvatures to improve aesthetic design quality. This paper advocates formalizing aesthetic curve and surface theories to fill the gap mentioned above, which has existed since the 1970s. This paper begins by reviewing on fair curves and surfaces. It then extensively discusses on the technicalities of Log-Aesthetic (LA) curves and surfaces and touches on industrial design applications. These emerging LA curves have a high potential for being used as standards to generate, evaluate and reshape aesthetic curves and surfaces, thus revolutionizing efficiency in developing curve and shape aesthetics.

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Both natural ores having mineral assemblages of chalcopyrite-monoclinic pyrrhotite and of cubanite-chalcopyrite-hexagonal pyrrhotite were heated in evacuated glass tubes to measure sulfur fugacity at temperatures from 300° to 450°C by electrum-tarnish method. The values of sulfur fugacity were also reconfirmed by pyrrhotite indicator method using chemical composition of coexisting pyrrhotite after heating. They obtained by both methods were in good accordance.
According to the results of the experiments, the ore containing cubanite showed lower sulfur fugacity values than the ore not containing one. It suggests that eubanite has been formied under a lower sulfur fugacity condition. By the heating experiments, the tie line change of mineral assemblages from chalcopyrite-pyrrhotite to intermediate solid solution-pyrite was found at 350°C.

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Edited by the Abstracting Committee, Japan Association of Mineralogical Sciences

Ore Minerals and Economic Geology
Age Determination 104168—104170;
Gold Mineralization 104171—104182

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