A photometric method for the determination of a microamount of silicon in vanadium metal is proposed. The method involves the extraction of silicomolybdic acid into methyl isobutyl ketone (MIBK) and the formation of molybdenum blue in the extract. By the method, more than 20 ppm of silicon in vanadium can be determined. The procedure is as follows. The sample is dissolved in nitric acid, evaporated to dryness, fused with sodium carbonate and dissolved with hydrochloric acid. An aliquot (V<50 mg, Si<50 μg) of the solution is taken and made up to 50 ml while keeping the acidity at 0.4M in hydrochloric acid. The solution is then treated with ammonium molybdate and oxalic acid, and silicomolybdic acid is extracted with MIBK. The extract is washed with hydrochloric acid and treated with stannous chloride solution. The absorbance is measured at 750 mμ using the solvent as a reference. The calibration curve should be prepared in the presence of the same amount of vanadium as that in sample solution.

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8-ヒドロキシキナルジンを用いるベリリウムの比色定量法を適用し,ベリリウムー銅ならびにベリリウム-アルミニウム合金中のベリリウムを定量した.この際,定量の妨害となる銅,アルミニウムをそれぞれシアン化カリウム,EDTAによって直接いんぺいする方法について検討し,ベリリウム1～5%の合金について±0.02%以内の誤差で定量できるようになった.銅のいんぺい剤であるシアン化カリウムは吸光係数に変化をあたえないが,アルミニウムのいんぺいに用いるEDTAは吸光係数を低下させることがわかった.なお,合金中の不純物である鉄,ニッケル,コバルトなども同時にいんぺいされ定量の妨害とならない.

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ο-フェナントロリン-鉄の錯体を用いるアルミニウムーバナジウム合金中の鉄の吸光光度定量法について検討した.バナジウムを含む酸性溶液に塩酸ヒドロキシルアミンを加えて還元するとともに錯体を生成させ,酢酸ナトリウムと水酸化ナトリウムを用いて pHを 4.0 ~ 4.5 とすることにより無色とする.続いて硫酸を用いて pHを 1.8 ~ 2.2 まで下げて放置しても30 分間は安定であり,共存する150 ppm までの鉄を精度よく定量できる. pHを 4.5以上にした場合は,バナジウムは一部酸化されると考えられる.発色時の pHは1.8 ~ 2.2が適当であった. pH 1.8 以下では VO²⁺によりVO (C₁₂H₈N₂)²⁺ という錯体を生成する.また pH 2.2以上では時間とともに吸光度が減少した. これらの諸条件の検討において50 mgまでのアルミニウムはまったく影響しなかった.

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ベリリウム銅中のケイ素迅速定量法としてモリブデン青による比色定量法を検討した.その結果,発色時の酸濃度(0.4N),放置温度ならびに時間(25℃で5分間),試薬の添加量などの影響をしらべ,次のような分析法を確立した.
試料をはかり硫酸(1:6)20mlと過酸化水素5mlで溶解し,加熱して過酸化水素を分解したのち,250mlに希釈する.その50mlをピペットでとり10%モリブデン酸アンモニウム溶液6mlを加えて25℃で5分間放置後フッ化水素酸を加えて銅,リン,ヒ素などのモリブデン酸塩を分解したのち,ただちに30%硫酸第一鉄アンモニウム溶液4mlを加えてモリブデン青に還元する.1分間放置後,その吸光度を測定してケイ素含有量を求める.本法によるケイ素の定量結果は重量法とよく一致した.また,分析時間は重量法に比べて大幅に短縮することができた.

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In this paper the fundamental investigations are performed to measure the stresses at the cutting edge during metal cutting operation by using of the method of Caustics formed by reflected light ray from the metal surface. In standard method of Caustics the models made of the transparent material are used, but for the stress analysis in the cutting tool under the actual operating conditions it is needed to investigate the difference from using the transparent model by performing the experiments using the metallic model. Two dimensional problems are treated and the objects of study are half plane and wedge shaped plane loaded perpendicularly or obliquely. Specimens are made of aluminium plate of about 6 mm thickness. The Caustics patterns formed by the reflected light from the polished front surface were observed and those characteristics with the loading conditions are investigated in detail. On the other hand the computational patterns based on the optical theory are plotted. These two patterns are coincided accurately enough. Furthermore it was found that the presented results for the metallic specimens were similar to those of previous report for the transparent specimens under the same loading conditions.

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緑柱石中の酸化ベリリウムをケイフッ化ソーダにより疏解して得られたベリリウムフッ化ソーダを主体とする抽出液をイオン交換樹脂により精製する方法について検討した。H 型ならびにN a 型陽イオン交換樹脂の精製効果を比較検討した結果,H型ではベリリウムの初期吸着が著しく,また初期精製効果がほとんどないのに対し,Na型の場合には,抽出液中のFe, Al … … , 等はほとんど吸着分離され, またベリリウムの初期吸着もなく, 97～98% BeO を97～99% 精製収率で得られることがわかった。
なお,基礎研究において,ベリリウムが陽イオンとして存在する系についてのイオン交換樹脂による分離試験を行ない, 良好な結果を得た。

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Effects of the velocity gradient of linear shear flows at a high Reynolds number (Re, _s=4000-35000) on lift and drag applied on a spherical particle are investigated by measuring surface pressure distribution, using a pendant method, and by comparing computed and photographed trajectories of a sphere falling in upward shear flows. It is made clear that lift is applied on a sphere from the higher velocity side to the lower velocity side, that it increases as the velocity gradient becomes greater, and that drag is hardly affected by the velocity gradient.

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A measurement system of transit time of ultrasonic waves propagating through the thickness of plates under plane-stress state was developed, which is an improvement of the zero-crossing method with a personal computer and a high resolution digital memory or oscilloscope.
In this system, thirty pairs of the first and second echo profiles stored in a digital oscilloscope are averaged in a personal computer, and then the rising portion of the averaged wave profile is enlarged on a screen of the computer and fitted to a straight line. The transit time of the echo is determined by the ordinate of the cross point of the straight line and the zero line. This system can measure the transit time to an accuracy of 1ns for shear waves propagating through an aluminum specimen.
The acoustoelastic constants of a 2017-T3 aluminum plate of which rolling direction was parallel to the uniaxial tensile direction were found as follows; the constant for initial anisotropy=6.5×10^-3, the stress-birefrigent coefficient=-34×10^-6MPa^-1.
Using these constants, the principal stress difference of the residual stress in an annulus which was shrink-fitted to a shaft was measured. The tangential and radial residual stress components were separated with the elastic solution of plane axisymmetric stress field. They were in good agreement with the analytical results.

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A fractographic analysis was made on two kinds of silicon nitride, glass ceramics and borosilicate glass fractured under monotonic tensile loading and tension-compression cyclic loading. Emphasis in the fractographic investigation was placed on the fracture initiation area. The relation between mirror size and fracture stress was investigated under various stress conditions. The mirror sizes observed on the fracture surfaces of tensile fractured specimens were approximately 60% of those for bending tests when the comparison was made at the same fracture stress. The fractographic observation on the area of fracture initiation revealed that the fracture in silicon nitride-B always occurred from the defects formed during sintering, while in silicon nitride-A, in which fracture always occurred from the surface, no defect was observed in the fracture initiation area. This result means that the fracture in silicon nitride-B occurs by the crack growth from these defects (formed during sintering), while in silicon nitride-A, fracture initiation occurs by the cracking formed along the grain boundaries by SCC in the surface layer, and then these cracks grow by SCG to final failure. The results of EDX analysis on the fracture initiation area of silicon nitride-A showed that the relative content of Y, which is the main element of sintering aid additions, was higher in the region inside of the critical crack size than in the region outside this region. This will probably show that the crack growth occurred by SCG in this area and by rapid growth in the area outside of the critical crack size. This observation seems to support the fracture intiation process discussed above on the fracture of silicon nitride-A.

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コランダム単結晶の水熱育成法は未だ確立されているとはいい難い。本報ではこの方法におけるいくつかの問題点,オートクレーブ内の温度差の問題,育成のための最適温度圧力条件,種子結晶,原料など反応物質の問題,時間と成長率との関連の問題についての実験結果をもとに,本法の特質を考察した。この結果,オートクレーブ内の温度差は外壁測温の場合よりかなり小さく,とくに銀カプセルを用いた場合ほとんど無視できるものとなる。コランダムの溶解速度に対する著者らの数値を用いて,この温度差の実効値について半定量的に議論した。つぎに,最適温度圧力については高温高液充填度ほどよいことがわかった。高温は結晶成長速度を速め,液の高充填度は,温度差の実効値を大にするものと考えられる。種子結晶については,成長に少なくとも2段階あり,種子のカット方向が重要であろうことが示唆される。原料については,コランダム,あるいは水酸化アルミニウムの状態の時間変化の影響は認められなかった。成長機構は成長段階が少なくとも二つあることに特徴がある。現在まで著者らの実験方法で数cmのコランダム単結晶を得ることができるが,鉄イオンの混入による着色を除去するのは困難である。

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ケイフッ化ソーダ法により緑柱石中の酸化ベリリウムを高収率,高純度で疏解分離する方法について,ケイフッ化ソーダの添加量,焼成温度,焼成時間等について検討した。その結果,緑柱石微粉末と等量のケイフッ化ソーダを加え,850℃で2時間焼成した場合が最もよい条件であることがわかった。その場合のSiO2含有量は3%以下で,93～95%の比較的純度の高いBeOを90～93%の収率で得た。更に塩化ナトリウムを第二のフラックスとして若干加えることにより,有効かつ有毒なフッ素分は完全に回収され,ケイフッ化ソーダ添加量を0.75倍量に節約でき,SiO2量が2%以下の純度の高い酸化ベリリウムを94%の収率で得た。

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Anodic oxidation of electrodeposited Co in alkaline solutions was investigated to improve the coercivity of thin films in the potential range where Co(OH)₂ might form. The coercivity of the Co film was increased extensively by anodic oxidation. This is attributed to the isolation of individual Co particle caused by the formation of hydroxide at the grain boundaries.

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