ポアフリーで, 電気的特性ばらつきが小さい弾性表面波フィルター用圧電セラミックスの製造方法について検討するとともに, 中心周波数11-90MHzの弾性表面波フィルターを試作した.
Pb(Sn_1/2Sb_1/2)O₃-PbTiO₃-PbZrO₃-MnO₂系圧電セラミックスを空気中で焼成すると1150℃からポアの生成が始まるが, 酸素中では, ポアフリーなセラミックスが得られ, 密度は1.3%上昇した. この組成系では, 反応中間相であるパイロクロア相Pb₂SnSbO_13/2が粒成長を抑え, 球状粒子を形成すると同時に, ポアを焼成体外へ素早く排出するものと考えられた.
ポアフリーセラミックスの鏡面状態での表面粗さは0.05μm以下であり, 90MHz用すだれ状電極 (電極幅6.7μm) を容易に形成することができた. 酸素中焼成のものは空気中のものに比べ縦波モードで20m/s (約0.8%, ヤング率換算で3.0%), 弾性表面波モードで27m/s (約1.1%) それぞれ音速が増大した. 弾性表面波速度のばらつきσ/xは基板内で0.10%以下, ロット内で0.15%以下であり, 単結晶並の特性をもつことが明らかとなった. また弾性表面波の減衰は周波数範囲90MHz以下では主にセラミックスの内部摩擦からくるものと考えられた.

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(1) The temperature property of resonant frequency of Pb(Sn_1/2Sb_1/2)O₃-PbTiO₃-PbZrO₃ ternary system was studied, and it was found that the three dimensional expression, composition-frequency constant-temperature, would give us better scope than the two dimensional expression; e.g. the composition- temperature coefficient of resonant frequency, which has been widely used.
(2) The composition which gives minimum frequency constant was constant value independently modes of vibration, and it was found that the mixing ratio of ferroelectric tetragonal and rhombohedral phase was approximately 1 to 1 at this composition which was considered as the center of morphotropic phase boundary.

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Physical and electrical properties of Pb(Sn_aSb_1-a)O₃ ceramics are described. Pb(Sr Sbt1-a)O3 compound has a cubic pyrochlore type structure represented by the formula Pb₂Sn_2aSb_2-2aO_7-a (1/8<a<2/3). The relative intensity of X-ray diffraction lines fitted well with the calculated one when the crystal structure of Pb(Sn_aSb_1-a)O₃ was assumed to have the pyrochlore type structure.
The ceramics formed under the hot pressing condition had high density and its microstructure was composed of a mixture of fine grains (1-2μ) and coarse grains (-10μ).
Electrical resistivity of a hot pressed sample (a= 1/2) greatly changed its original value after annealing in oxygen gas.

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Microflora of Kaburazushi (fermented turnip and yellowtail with malted rice) and Daikonzushi (fermented radish and Pacific herring with malted rice), traditional fermented food in Kanazawa, Japan, were surveyed by a simple method using several selective media and non-selective media. In the case of the Kaburazushi or Daikonzushi made by four factories, predominant bacterial groups were lactic acid bacteria (lactobacilli and/or lactococci), however samples obtained from the different factories showed different numbers of lactic acid bacteria (10⁴ to 10⁸/g) and the numbers did not correlate with the concentration of lactic acid and the pH value. In the case of the homemade samples, the numbers of lactic acid bacteria increased to about 10⁸/g in three days and correlated with the increase of lactic acid concentration and the lowering of pH value. The numbers of yeast decreased about from 10⁵ to 10²/g during seven to 14 days' fermentation. The numbers of halophilic bacteria and contaminants, such as bacilli and coliforms, were decreased with the fermentation. These results indicate that the character of the microflora and fermentation of some Kaburazusi and Daikonzushi made by factories differs from that of the homemade variety.

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  Various properties of grown nodular graphite cast iron around wear characteristic were investigated and furthermore the iron was compared with sintered iron for structural parts (SMF4020) whose inner structure was similar to grown iron to promote the probability of utilization as new industrial materials. The resutls obtained were summarized as follows :
1) Density of the iron decreased and damping capacity increased with the growth, but higher mechanical properties were kept even after 10% linear growth (tensile strength; 70kgf/mm², BHN; 180).
2) Wear resistance increased with the growth and melting wear vanished in the range of high friction speed and furthermore adhesive wear vanished in 10% grown iron. Those depended on the results that the iron grew due to the mechanism of irreversible graphite migration and fine graphite nodules redistributed in the matrix and the area of lubrication increased.
3) Wear resistance of all grown irons was superior to that of sintered iron in all friction speed and amount of wear was about from 1/2 to 1/3 that of sintered iron on the average.
4) It was thought that grown nodular graphite iron might be new industrial materials which could be partially replaced with sintered iron. Especially, 2% grown iron was thought to have a bright prospect as it had high tensile strength (80kgf/mm²), high damping capacity (5 times that of as-cast iron), high wear resistance (3 times that of sintered iron at the maximum) and cheaper cost for manufacture.

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The fiber orientation distribution in fiber reinforced thermoplastics (FRP) affects the strength and the final shapes of products. Therefore, for effective product design using computer simulation, it is necessary not only to estimate the fiber orientation distribution, but also to mea-sure it. Although the fiber orientation has been measured using image analysis with soft X-ray photographs of thinly sliced FRP, only the 2D fiber orientation is obtained with these soft X-ray photographs. In recent years, a method to measure the 3D fiber orientation by using images of cut sections of FRP observed through scanning electric microscopy (SEM) has been reported. However, the azimuth angle of the 3D fiber orientation cannot be calculated. We thus propose a method to calculate the 3D fiber orientation by observing the elliptical marks and the interference fringe patterns in cut sections of FRP through scanning acoustic microscopy (SAM) in this paper. This method enables us to calculate the azimuth angle and measure the 3D fiber orientation in both the core layer and the skin layer. We show the effectiveness by measuring the 3D fiber orientation of a general cylindrical material.

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漆塗膜は紫外線に対して脆弱であることが広く知られているが²⁾, 漆塗りが外装にほどこされた歴史的建造物においては, 紫外線のみでなく, 風雨などその他の劣化要因も存在する。本稿では実際に外装に用いられる漆から黒漆を選択し, 劣化要因となりうる紫外線照射や水漬, さらに, それらのサイクルによる劣化促進実験を行った。とくに, 水漬後は風乾あるいは水滴除去をほどこし, 塗膜表面に残存した水滴の有無によっても表面状態に差異が生じるかどうかを検討した。劣化促進実験後は, 光沢度の変動に加え, 走査型電子顕微鏡による表面観察から劣化状態の評価を行った。その結果, 紫外線照射後の水漬により塗膜成分の一部が流失し, 塗膜表面に微小な空隙孔を多数形成していた。また, 紫外線照射および水漬の後, 風乾させた塗膜では, 光沢度の減少がいちじるしく, もっとも表面状態が乱雑化していた。このことから, 紫外線照射後の水漬による劣化表面の除去, あるいは水分蒸発が漆塗膜表面におよぼす影響が甚大であることが確認できた。同時に, 水漬直後に塗膜表面の水分を速やかに除去することによって, 漆塗膜の表面光沢をある程度維持できることも明らかになった。

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An aluminum alloy surface-treated with pure water was directly joined to a rubber containing different fillers to prepare a dissimilar materials joint. In order to study effect of filler on joint strength and joint state, a peeling test and observation for aluminum alloy surface before and after joining were performed in the dissimilar materials joints. There was a difference in the joining strength of the dissimilar materials joint depending on added filler. Microstructure formed by the surface treatment remained on the aluminum alloy surface in dissimilar materials joints after the peeling test, however its morphology was different depending on added filler. Therefore, it is speculated that the filler influences the surface morphology and results in different joining strength.

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