The brittleness of Sendust with the nominal composition of 9.6% silicon, 5.4% aluminum and the balance of iron has been studied experimentally. By high thermal stress due to temperature gradient in the crystal, cleavage cracks along {001} plane or grain boundary cracks are easily introduced during either solidification after casting or subsequent heat treatments. The {001} cleavage cracks are also formed under applied external stress. Fracture stress of hot rolled Sendust examined by bending tests is higher than that of cast one, indicating the removal of internal defects by hot rolling. The single crystal which was prepared by zone-melting, and therefore, less-stressed thermally can be bent plastically even at room temperature, showing a lack of internal defects acting as the origin of cracking.

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The transport of steroid hormones was investigated for a liquid membrane system using bovine serum albumin (BSA) as the carrier that separated the hexane source phase from the hexane receiving phase. The experimental results could be adequately explained by a model in which hormones are transferred from the hexane source phase to the water membrane for binding with BSA and then transported through the membrane in both BSA-bound and free forms. Based on the results of analysis, the dynamic parameters for transport were determined. For a hormone with a lower water/hexane partition coefficient, the uptake from the hexane source phase to the water phase was one of the rate-determining steps in the transport and hormone transport was accelerated by the addition of BSA. The release process from the water phase to haxane receiving phase is the rate-determining step when the partition coefficient is high. Transport is thus governed by concentration of the hormone in the free form on the water membrane and hormone transport is decelerated by the addition of BSA, since the concentration of the free form decreases inversely by association with BSA for the system in which the amount of hormone in the hexane source phase is limited.

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液膜法によりHTABミセルを担体とするステロイドホルモンの輸送が実験的に確かめられ,実験結果はヘキサン原相よりいったん水溶液膜に分配されたホルモンが,界面拡散層でHTABミセルに内包され,遊離型ホルモンとともに輸送されるとしたモデルで動力学的に説明された。水/ヘキサソ分配係数の低いホルモンの場合は.ヘキサソ原相から水相へのホルモンの取込み過程が律速となり:HTABの添加は輸送を促進する。分配係数が高くなると0水相からヘキサン受相へのホルモン放出過程が律速となり,水溶液膜中の遊離型ホルモン濃度が輸送を支配するようになる。そのため,水への分配係数の高いホルモンでは,ヘキサン原相のホルモン量が有限の系では,As!の添加は水相中の遊離型ホルモン濃度を逆に低下させる結果,ホルモン輸送は逆に阻害されるようになる。

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The transport behavior of steroid hormones and their derivatives was investigated in a liquid membrane system with bovine serum albumin (BSA) as a carrier separating a hexane source phase (I) and a hexane receiving phase (II). The rate constant of hormone uptake from the hexane phase (I) to the water phase was designated as k₁ and the rate constant of release from the water phase to the hexane phase (II) as k₂. Positive correlations were found between k₁ and the water/hexane partition coefficient of the hormone, while inverse correlations were noted between k₂ and the partition coefficient with and without added BSA. For lower partition coefficients, hormone uptake from the hexane phase (I) was rate-determining in the transport process, while release of the hormone from the water became so with increase in the partition coefficient. Transport behavior through the water membrane was governed primarily by partition coeffcients between the water/hexane phases. For hormones, whose partition coefficients were less than 0.02, transport was accelerated by the addition of BSA. For hormones with partition coefficients over 0.02, the rate of transport lessened on addition of BSA.

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Deformability by hot rolling of Sendust and magnetic properties of hot rolled Sendust have been investigated as a function of composition. With increasing silicon content at a constant aluminum content, deformability decreases, while it is not changed by increasing aluminum content at a constant silicon content. These results are qualitatively explained on the basis of mechanical tests at lower strain rates. Magnetic properties are improved by hot rolling, and especially the initial permeability is raised in the low frequency range. Molding and μ_i-temperature characteristics of cast and hot rolled Sendust are quite sensitive to composition. Segregation of alloying elements introduced during solidification is removed by hot rolling.

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Vacuum hot pressing of Fe-10%Si-6%Al alloy (Sendust) powder prepared by Ar-gas atomizing was carried out at temperatures between 1123 and 1273 K and at pressures between 100 and 200 MPa for various periods of time up to 7.2 ks.
Under the pressure of 100 MPa, the compacts having high relative density (>99%) were obtained at a temperature higher than 1223 K. At a lower temperature such as 1173 K, a higher pressure (200 MPa) was necessary to obtain the compacts having a high relative density (>99%).
The high temperature deformation behaviors of the compacts were also investigated by compression tests at various temperatures corresponding to the hot pressing temperatures using the compacts having the density higher than 99%. The results indicated that, in this alloy, the high temperature deformation behaviors changed at the temperature (\simeq1173 K) where the DO₃\ ightleftarrowsα order-disorder transformation occurred. Remarkable differences in the deformation behavior were recognized between lower and higher temperatures than this temperture. These facts were presumed to be a cause of the observed difference between densification behaviors of the compact at the lower temperatures (1123 K and 1173 K) and the higher temperatures (1223 K and 1273 K) during hot pressing.

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The affinity of bovine serum albumin (BSA) to progesterone, testosterone and androsterone was found to increase significantly by the binding of free fatty acids (FFA) such as myristic acid, palmitic acid and stearic acid, to BSA, while the binding of FFA to BSA affected differently the transport of these hormones through an aqueous membrane containing BSA from a hexane source phase (I) to a hexane receiving phase (II). The main factor governing transport is thought to be the partition coefficient of hormones between the water and hexane phases. The rate constant of hormone transport from the hexane phase (I) to the water phase was defined as k₁ and that from the water phase to the hexane phase (II) as k₂. In the case of a hormone with a lower partition coefficient such as progesterone, the binding of FFA to BSA increased both k₁ and k₂, and accelerated hormone transport. For testosterone with a higher partition coefficient, k₁ did not change, but k₂ decreased to cause decrease in rate of hormone transport. For androsterone with a moderate partition coefficient, k₁ increased, but k₂ decreased so that the binding of FFA had no effect on hormone transport flux.
During transfer from the water to hexane phase (II), the transport rate constant of BSA-binding was 0.050.1 that of the free hormone transport from the water to hexane phase (II) indicating decrease of the rate by the binding of BSA to the hormone. The transport rate constant of BSA-binding was noted to increase for progesterone, to show no change for other hormones by the binding of FFA to BSA.

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Based on the previous result that the steady state deformation is observed in the Sendust single crystals, deformation behaviors of Sendust polycrystals were investigated in compressive tests at various temperatures and strain rates.
The steady state deformation occurs at high temperatures and low strain rates. Under the conditions, the strain rate is represented by the relationship of \dotε=Bσⁿexp(−Q⁄kT), where n=4.3 and Q=360 kJ/mol. Compared with the values obtained on Sendust single crystals, n is nearly equivalent but Q is considerably lower. Sendust polycrystals can be plastically compressed to high strain under the conditions where the steady state deformation occurs. After the deformation, fine recrystallized grains are formed at original grain boundaries, and sub-boundaries and dislocation networks are observed within original grains. The steady state deformation of Sendust polycrystals is controlled by grain boundary sliding, grain boundary migration and dynamic recrystallization. On the contrary, the steady state deformation of Sendust single crystals can be explained in terms of the recovery-controlled mechanism.

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Deformability by hot rolling of Sendust with the nominal composition of 9.6% silicon, 5.4% aluminum and balance iron has been investigated as a function of hot rolling temperature and reduction per pass. It was found that under the optimum rolling conditions Sendust became ductile and was hot rolled without grain boundary cracking or cleavage cracking. The optimum rolling conditions are consistently derived from conditions of ductile deformation in tensile or bending tests at the lower strain rate region.

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It has been revealed in previous papers that under the conditions where the steady state deformation is observed, Sendust alloys can be plastically deformed to high strain without cracks in compressive tests. In this study, deformation behaviors of Sendust polycrystals were investigated by the experiments that tensile stress was predominantly applied, such as bending tests and tensile tests.
In the diagram showing the relation between the logarithm of the cross head speed and the reciprocal of the absolute temperature in bending tests, a straight line is obtained as the critical conditions of the ductile-brittle transition of deformation.
Below 800 K, cleavage fracture is dominant independent of the deformation conditions. Above 900 K, either cleavage fracture or grain boundary fracture is observed depending on the deformation conditions.
By extrapolating the straight line of critical conditions of ductile deformation to a higher strain rate region, the optimum condition of hot rolling or forging can be determined.

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Cast Fe-Si-Al alloys containing 0.5%Ti, 0∼0.06%C, 0.2%rare earth metal, were prepared using a 10-kg vaccum induction furnace. Fe-Si-Al alloy cores for magnetic recording head were produced by grinding from those alloys which were hot-rolled and annealed at 900∼1100°C. In this paper, the effect of grain size on chipping resistance in rough cutting, groove grinding and fine cutting of head-cores process is studied. The results obtained are as follows. \ding”C0 The methods to obtain a fine grain size of Fe-Si-Al alloy are “hot-rolling” and “adding the minimum quantity of inhibiting grain-growth elements C, Ti, M. M. to alloy”. The former is the best method to obtain alloys with fine grains. \ding”C1 The larger the grain size in Fe-Si-Al alloys, the more the number of chips increases. \ding”C2 Both the depth and the number of chips are larger in cast alloys than hot-rolled and annealed alloys. \ding”C3 Alloys with fine grains are obtained by the adding two elements (Ti & C) to alloys rather than adding one element (Ti or C).

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除草剤CNP及びプレチラクロール原体についてコイに対するBCFを求めた。両薬剤について処理濃度1及び30ppbで14日間の処理を行った。処理期間中のBCFはかなり低い蓄積性の部類に属し, 最大値でもCNPで62, プレチラクロールで48であった。
また, 供試魚を14日間処理後清水に戻すとプレチラクロールでは急速に体外へ排出されることがわかった。

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CNPを一定濃度に溶解した人工海水を用い, ムラサキイガイを飼育し, 3種類の還元代謝物 (CNP-NH₂, CNP-formamide, CNP-acetamide) の生成量を経時的にECD及びN-PFIDガスクロマトグラフィーで測定した. CNPの水中濃度約12ppbで9日間飼育したとき, CNPはイガイに蓄積され30～35ppmに達し, 同時にCNP-NH₂, CNP-formamide はそれぞれ0.2ppm (CNPの約0.6%) の濃度で生成していることが認められたが, CNP-acetamide は検出されなかった. 清浄な海水にイガイを移すと, そのCNP濃度は生物学的半減期4～8日で減少した. それとともにCNP-NH₂, CNP-formamide は0.2～0.3ppmを最高値にCNPの排泄速度ほどは速やかではないが減少した.

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室内実験条件下で二枚貝のムラサキイガイに対して除草剤モリネート, ベンチオカーブ, CNP及びクロメトキシニルの蓄積及び排泄を組織部位別に調べた. それぞれの生物濃縮係数は10, 100, 2,600及び500で, 薬剤の水に対する溶解度と生物濃縮係数との間には負の相関を認め, 中腸腺や生殖腺のような脂肪含量の高い組織への蓄積性が高かった. またその排泄は, モリネートは速やかに, その他は生物学的半減期で表わすとベンチオカーブ約0.7日, CNP4～8日, クロメトキシニル1.6日であったが, 各組織毎の半減期には有意な差は認められなかった. ムラサキイガイに蓄積された4種の除草剤は, その90%以上が未代謝のまま排泄されることが示唆された.

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The binding of steroidhormones to bovine serum proteins was examined so as to explain the transport behavior of steroidhormones by proteins in serum. The affinities of bovine serum proteins prepared by Cohn's separation method with six kinds of steroidhormones (α-estradiol, ethynylestradiol, progesterone, androsterone, dehydroisoandrosterone and testosterone) were measured from partition experimental results. The affinity of Cohn's fraction III with hormones was not observed, but binding to fraction IV-1 and V (albumin) was clearly evident. When these hormones were added exogenously, binding coefficients K (protein-binding form/free form) in 3.5% bovine serum albumin (BSA) solution were 4080% of those noted in bovine serum containing the same amount of albumin.
The effect of the binding of free fatty acid (FFA : C_{14 : 0}, C_{16 : 0}, C_{18 : 0}, C_{18 : 1} and C_{18 : 2}) with BSA on the affinity of BSA to steroidhormones was also investigated. Change in affinity could not be clearly detected for α-estradiol, ethynylestradiol or dehydroisoandrosterone, but a distinct increase was observed for progesterone, androsterone and testosterone following the addition of FFA. The binding coefficients of the latter three hormones increased by 5060% beyond that of the repeated control without the addition of FFA.

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