Irgafen and Sulfisomidine were administered into the embryonating eggs of white Leghorn, and histopathological examinations were conducted on the thyroid-gland of the embryo.
Irgafen enhanced the development of thyroid-gland, while Sulfisomidine caused the productive changes of the follicular epithelia.

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To investigate the effect of atmospheric-corrosion on the early stage fatigue cracks, fatigue tests were made in air and in vacuum (3×10^-3mmHg) on α-brass under push-pull loading, and both external and fractured surfaces were observed by means of optical and scanning electron microscopy.
It was found that fatigue lives, compared with the case iron, were much longer in vacuum than in air, and the improvement in life increased as the stress amplitude was reduced. The number of cycles up to fatigue crack nucleation in vacuum was found to be about 44 times longer than that in air. Crack nucleation in vacuum occurred predominantly along the slip bands. The number of intercrystalline fracture surfaces increased as crack length and stress amplitude increased. The morphology of transcrystalline fracture surfaces in vacuum was similar to that in air. On the other hand, in vacuum, intercrystalline fracture surface was not observed within the interior of the specimen and few near the specimen surface. Striations observed in vacuum were not clear.

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The measurement of fatigue crack tip opening and closing points in a machine element with complicated shape is expected to involve difficulties. In the present study, the measurement of crack opening and closing points in a center notched thin plate was carried out by the unloading elastic compliance method and the strain interference method, and the application of these methods to an actual machine equipment was discussed. The strain measurements were carried out at several positions around the notch and crack for the purpose of determining crack opening and closing points. When the bending of the specimen arises during a push-pull fatigue process, the measurement of crack opening and closing points becomes more difficult unless the proper measuring position is chosen. However, when the strain function consisting of strains measured at two diffent positions on the same longitudinal axis is used in the case of strain interference method, the crack opening point can easily be measured with sufficient accuracy.

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In previous papers, the authors discussed the J-integral range, ΔJ, evaluated by the path integral and by Dowling's simple estimation formula and showed that ΔJ was a good parameter for characterizing the crack tip stress and strain field under uniaxial and elastic-plastic conditions. In this paper, finite element simulations of fatigue crack growth in a plate under biaxial stresses are conducted in order to clarify whether ΔJ is also applicable under biaxial conditions. It is found that ΔJ-values evaluated by the path integral are almost path-independent irrespective of the depth of crack and ratio of transverse and longitudinal applied stresses. Furthermore, the examination of the relationship between ΔJ and the crack-tip-opening displacemint leads to the conclusion that ΔJ evaluated on the basis of crack opening level is the most appropriate parameter for representing the mechanical state near the crack tip under biaxial loading. ΔJ evaluated by the simple estimating formula is found to agree well with ΔJ evaluated by the path integral.

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The effect of atmospheric-corrosion on the fatigue crack nucleation and fracture surface morphology in the early stage of fatigue has been investigated by tests in air and vacuum on pure iron. The experiments were conducted under push-pull loading, and both external and fractured surfaces were observed by means of optical and scanning electron microscopy.
It was found that the fatigue lives of iron in vacuum were 2.1 times those in air and the fatigue limit was also 1kg/mm² higher in vacuum than in air. The density of slip lines in the specimens tested in vacuum was much higher than that in air and the cyclic numbers up to fatigue crack nucleation in vacuum were found to be 2.6 times those in air. The morphology of initial transcrystalline fracture surfaces in air was classified in two types and the number of intercrystalline fracture surfaces was decreased as stress amplitude increased. The morphology of initial transcrystalline surfaces in vacuum was similar to that in air. No intercrystalline fracture surfaces were observed in the specimens tested in vacuum. Clear striations were found on the fracture surfaces of the specimens tested in vacuum, though most of the surfaces have a flattened and smeared appearance.

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Damage in rolling contact fatigue was observed using polycarbonate which is a transparent material. The rolling contact fatigue tests were performed using a set of one polycarbonate and one carbon steel S45C rollers under lubricated condition. In the tests, damage occurred only in the polycarbonate. With the carbon steel was set as the drive side, experiments in which the rollers were rotated in a single direction and those in which the direction of rotation was changed at a frequency of every 3×10⁵ times were carried out. In the former case, arrowhead shaped surface cracks were initiated, and pits were subsequently formed under the conditions of maximum principal stress criterion. In the latter case, pits were formed which appeared elliptic from a surface view. The cracks then grew from the pits bottom toward the center of roller. When the polycarbonate was set as the drive side, internal cracks initiated in shear mode, then the surface layer of the polycarbonate peeled off. From those experiments, it was found that damage mechanisms of rolling contact fatigue changed depending on the loading conditions. These mechanisms are influenced by the friction of the roller surfaces and the pressure of the oil which enters the cracks.

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If fatigue crack initiation and growth behavior in structures and materials can be detected based on strain information on the surface, the detecting method becomes a practical one for evaluating the fatigue damage and the residual life. From this standpoint, the strain interference method of detecting crack initiation and crack growth becavior was proposed by one of authors and the effectiveness of the method has been shown mainly through the fatigue tests using center-cracked specimens. In this paper, the applicability of the strain interference method to double V-notched specimens is investigated. First, the finite element analyses are carried out for double V-notched specimens, which are subjected to the tension-compression axial loading. The locations of strain measurement for detecting crack initiation and crack tip opening and closing points are discussed. After that, the exial loading fatigue tests of the specimen are carried out referring to the result obtained in finite element analyses. As a result of the experiment, it is shown that the crack initiation and crack growth behavior can also be detected by the strain interference method.

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沖縄県における地下水は，近年では，飲料用としての需要は減ってきてはいるものの，依然として住民の生活を支える上で重要である。地下水の水質については，水質汚濁防止法の規定に基づき常時監視が行われ，概況調査と継続監視調査で構成されている。沖縄県が行った平成22年度の継続監視調査では，砒素が7地点中4地点で環境基準値を超過，総水銀が3地点全て検出下限値未満，低沸点有機化合物（VOCs）が4地点で検出下限値未満または環境基準値以下，硝酸性窒素及び亜硝酸性窒素が1地点で環境基準値以下であった。VOCsと硝酸性窒素及び亜硝酸性窒素の発生源については人為的汚染として解釈されたが，砒素及び総水銀については，調査の結果，自然由来であることが示唆された。砒素については，還元状態の地下水に土壌に含まれる鉄が溶出する際に鉄に吸着していた砒素が溶出するタイプ（（1）タイプ）と，弱アルカリ性の地下水に接した際に鉱物中の鉄に吸着していた砒素が溶出するタイプ（（2）タイプ）とに分けられた。総水銀については，断層に沿って地下深部から上昇してきた水銀蒸気による可能性が高い。平成元年度から22年度までの調査結果は，将来の沖縄県の地下水の水質を考える上で重要な参考資料となる。

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The stress-strain field was assessed by means of the elastic-plastic finite-element method in the vicinity of the crack tip of the through-thickness-center cracked specimen subjected to cyclic loading under test conditions where ratchet deformation occurs. Then the cyclic J-integral range was calculated and its validity was examined. Both the maximum and minimum axial total strains at the crack tip during one stress cycle were greatly increased when ratchet deformation was generated. The path independence of ΔJ_op failed with the beginning of ratchet deformation, where ΔJ_op is cyclic J-integral range corresponding to load ranges above a crack opening point. Cyclic J-integral range ΔJ calculated through Dowling's conventional method, which was plotted against the crack tip opening displacement range ΔΦ_t calculated at 200μm behind crack tip, was situated on the smaller ΔJ side under test condition accompanied with ratchet deformation than under that without ratchet deformation. Meanwhile, the modified parameterΔJ/(1-Φ^min_c/Φ^max_c)^0.2 showed a good linear correlation with ΔΦ_t under all the test conditions with and without ratchet deformation. The earlier work in which one of the authors showed that the elastic-plastic fatigue crack growth rates were controlled quite well by means of the parameter ΔJ/(1-Φ^min_c/Φ^max_c)^0.2 might be realized in this way.

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In a previous paper, the present authors discussed the path-integral expression of the J-integral range, ΔJ, for short fatigue cracks emanating from notches, and showed that ΔJ evaluated based on the crack-opening level was an appropriate parameter for characterizing the near-tip stress and strain fields. In this study, finite-element simulations of fatigue crack growth from notches were conducted. The ΔJ-values evaluated by the path-integral were compared with those estimated by El Haddad's simple estimating formula proposed for short fatigue cracks at notches, and with those estimated by Dowling's formula and by Cho's formula proposed for deep cracks. The ΔJ evaluated by El Haddad's formula did not agree well with ΔJ values evaluated by the path-integral. On the contrary, ΔJ values evaluated by Dowling's formula based on the crack opening level agreed well with ΔJ values evaluated by the path-integral.

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絵本の読み聞かせを効果的に行うための読み手と聴き手のコミュニケーションの1つとして,絵本の読み聞かせ後の問いかけが子どもに与える影響について検討した.具体的には,物語理解とイメージ形成の2つの側面における子どもへの影響を実験的に明らかにすることを目的とした.年長児81名に対して,物語理解への影響を見る実験とイメージ形成への影響を見る実験の2つの実験を行った.それぞれの実験で,問いかけをする質問群と問いかけをしない統制群の2グループに分けて,物語理解度を測るテスト,イメージ形成量を測るテストを行い,分析対象として62名分のデータを得た.実験の結果,物語理解度は質問群の方が統計的に有意に高いことが示され,イメージ形成量は質問群の方が低いという有意傾向が示された.

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In previous papers, the authors discussed the path integral expression of the J-integral range, ΔJ, for short fatigue cracks emanating from notches under uniaxial stresses and showed that ΔJ evaluated based on the crack-opening level was an appropriate parameter for characterizing the near-tip stress and strain fields. In this paper, finite element simulations of fatigue crack growth at notches under biaxial stresses are conducted. It is found that ΔJ values evaluated by the path integral are almost path independent when the minimum-load level or the crack-opening level was selected as a reference level for the evaluation. The examination of the relationship between ΔJ and the crack-tip-opening displacement leads to the conclusion that ΔJ evaluated by the path integral based on the crack-opening level is the most appropriate parameter for representing the mechanical state near the tip of a crack emanating from notches under biaxial stress conditions. Furthermore, it is shown that ΔJ evaluated by Dowling's simple estimation formula based on the crack-opening level agrees well with ΔJ evaluated by the path integral.

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In previous papers, the authors discussed the J-integral range, ΔJ, evaluated by the path-integral and showed that ΔJ was a good parameter for characterizing the crack tip stress and strain fields under elastic-plastic conditions. In this study, finite-element simulations of fatigue crack growth at notches in a plate under uniaxial stress were conducted to examine the applicability of ΔJ to short fatigue cracks emanating from notches. It was found that Δl-values evaluated by the path-integral were almost path-independent when the minimum-load level or the crack-opening level was selected as a reference level for the evaluation. The value of ΔJ evaluated based on the crack-opening level correlated well with the crack-tip-opening displacement, while ΔJ based on the minimum-load level and the effective stress intensity range ΔK_eff did not. Crack closure was mainly responsible for the initial decrease in ΔJ-value and the deceleration of crack growth rates of short cracks emanating from notches.

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カンキツグリーニング病を媒介するミカンキジラミの発生抑制を考える上で,カンキツに登録のある殺虫剤,殺ダニ剤等既存の剤の組み合わせによって防除体系を作ることができれば周年ミカンキジラミの発生を防ぐことが可能になる。そこで14種類の殺虫剤(一部未登録)をミカンキジラミに対して浸漬,散布あるいは樹幹塗布処理して,その後の死亡虫数を実験的に調べた。その結果,DMTP乳剤とMEP乳剤は幼虫,成虫に対して処理1日後に90～100%の死亡率が得られ,速効的でかつ高い殺虫効果があると判断された。一方,イミダクロプリド顆粒水和剤とチアメトキサム顆粒水和剤は幼虫,成虫ともに処理5日後には100%の死亡率に達し,殺虫効果は高いがやや遅効的であった。これら2剤は残効が比較的長いことから防除体系の中心に位置づける剤であると考えられる。今後野外での防除効果の解明や登録に向けた調査が期待される。

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The location and preference of adult Asian citrus psyllid, Diaphorina citri Kuwayama, a vector of the citrus huanglongbing (greening disease) Liberobacter asiaticum, on two host plants, Murraya exotica L. and Citrus depressa Hayata, were investigated in Okinawa Prefecture, Japan. While the adults of D. citri were found on all parts of the C. depressa tree and on the M. exotica tree, all of the D. citri eggs and most of the nymphs and adults were found on young shoots and young leaves. We suggest that it is possible to save labor in the investigation and control of the psyllid by attentively checking the young shoots of M. exotica. Investigation on the distribution of D. citri adults on M. exotica plantlets hung upside down in a container showed that although no difference was found between frequencies of males on young leaves and mature leaves, significantly more females were found on the apical buds, suggesting that females have a preference for this part of the tree.

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