Objective. A duty of wear of a rear-seat belt was imposed from June 1, 2008. Although it was reported that non-worn seat belt at the rear-seated crew tended to worsen the head injury, there were no clinically studies to head injuries for rear-seated passengers.

Methods. The study was performed in 12 hospitalized patients in our unit with diagnosis of head injuries at rear-seated crew from January, 2004 to May, 2008.

Results. There were nine cases of brain contusion, eight cases of scalp laceration, including 3 cases of skull fracture under the wound. Also there were five cases of skull base fracture, 3 of acute subdural hematoma, one of acute epidural hematoma, two of diffuse axonal injury, respectively. 4 or more head injury Abbreviated injury score were recognized 75%. There were no special breast-abdominal traumatic injuries. Three passengers were wearing the seat belt; on the other hand 9 passengers were considered un-wearing the seat belt. GOS on discharge were 4 in GR, 5 in MD, 2 in SD, and 1 in D, respectively.

Conclusion. The characters for head injuries of rear-seated passengers were examined. Most of them were un-wearing the seat belt, and head serious injury rate was high. It seemed that long scalp laceration with skull fracture directly under the wound were characteristic. It is expected that head injury for rear-seated passengers will decrease and be slightly after the formation of seat belt wear duty.

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A prediction method of service loading from striations on fracture surface is proposed. Although it is well known that striation spacing corresponds to the crack growth rate da/dN, it is not possible to determine P_max and P_min under service loading only from s. This is because the value of s is influenced not only by ΔK but also by the stress ratio R (=P_min/P_max).
The new idea in this study for determination of P_max and P_min is based on the anticipation that the information on R must be included in the relative height of striation H to s. The results of fatigue tests on 2017-T4 Al Alloy CT specimens showed a definite correlation between H/s and R. The difficulty of the measurement of H was overcome by sectioning the specimens at an inclined angle and by measuring small distance using SEM.
Striations under R=-1 were compressed and flat, and H/s was small. With increasing R, H/s became large. Therefore, the standard laboratory test results on the relationship between s and ΔK, and also that between H/s and R enables us to predict service loading from the fatigue fracture surfaces.

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For the prediction of service load from fatigue fracture surface, not only the measurement of striation spacing(s) but also the information on stress ratio are necessary.
In the previous paper, the authors found that there was one to one correspondence between the ratio of striation height H to s (H/s) and the stress ratio R for 2017-T4 aluminum alloy. Since s ranges approximately from 0.1 to 2μm and H is smaller than s, the prediction of accurate R value requires the accurate measurement of H and s. For this purpose the procedure composed of cutting, polishing by emery paper and buff polishing was utilized previously. In this paper, an improved method using Microtome to reveal sharp striation sections is proposed and the improvement of measurement accuracy is shown.
In addition to 2017-T4 aluminum alloy, type 304 stainless steel was investigated in order to study the effect of mechanical properties on the relationship between H/s and R. The experimenal results gave almost the same relationship for type 304 stainless steel and 2017-T4 aluminum alloy. This result implies that the H/s-R relationship is independent of material properties, suggesting that one master curve of H/s-R and striation spacing s give a crucial information about the service load at the occurrence of fatigue fracture accidents.

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溶融Fe-Cr合金およびFe-Cr-Ni合金中のCrの拡散係数を1 5500℃において拡散対法によつて測定して,次の結果を得た.
(1)Fe-Cr合金中の相互拡散係数D_Fe-Crは0～15 at%Crの濃度範囲で次の実験式で表される.
D_Fe-Cr×10⁵=3.36-20.9N_Cr+171N²_Cr,cm²/s

(2)Ni濃度4at%,Cr濃度0～12at%のFe-Cr-Ni合金中のCrの主拡散係数D_CrCrはD_Fe-Crの1.3～1.9倍で,Niの添加によつてCrの拡散は速くなる.また,副拡散係数D_CrNi,D_NiCr,を推算した結果,これらは負の値をとり,その絶対値は主拡散係数にくらべて1オーダ小さいことがわかつた.

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A strong earthquake occurred at the Ebino-Yoshimatsu district on February 21, 1968. The most damaged area of this earthquake is covered by the Kakuto formation. The damages were much affected by the “Shirasu” or “Shirasu-like sediments”, which were the main parts of the Kakuto formation, representing the lacustrine facies of the Aira pumice flow which invaded into “Kakuto caldera”.

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平成5年8月6日に鹿児島市を中心に発生した土砂災害について, 写真判読を中心に災害特性調査を実施し, 報告した。調査内容は, 降雨特性調査, 地形・地質特性調査, および写真判読による崩壊発生特性調査である。
今回の災害は長雨後の集中豪雨が原因であったが, 日雨量の確率規模は20年～30年である。崩壊の発生箇所は地形・地質によって, シラス台地面浅谷の谷壁の斜面崩壊, シラス台地周辺部の斜面崩壊および山地の斜面崩壊に区分される。最も人的被害が大きかったのは山地に区分される竜ケ水急傾斜地である。シラス台地の土砂災害がほとんど表層崩壊であるのに対し, 山地部の災害の特徴は斜面崩壊と土石流が混在していることである。写真判読によると, この地区における土石流に対し, 治山・砂防施設の効果が明らかに発揮されているところが多く確認される。しかし, 地形的な制約からハード対策では限界があり, 総合的なソフト対策の検討も必要であるものと考えられる。

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　本研究は近代化遺産橋梁を対象とし、その保存決定の要因を明らかにすることを目的とした。
　研究対象の筑後川昇開橋は、佐賀線の廃止に伴い撤去が計画され、地域住民や自治体が保存要望を提出するなど保存運動が行われ、保存が決定した事例である。
　昇開橋の保存決定の要因は、地域シンボルとして認知度が高く、それによって地元の商業地区住民によって保存運動が起こり、また、地元自治体も昇開橋の観光資源としての利用に向けて、保存に向けた活動を行ったことが挙げられる。また、歩道橋として継続利用することができたこと、そして、保存に必要な撤去費用、維持管理費用、整備費用の財源を確保することが可能だったことが保存決定の要因となった。

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