Creep-rupture properties of 50mm thick 304 stainless steel joints by narrow-gap submerged arc welding were investigated at 550°C using small (round bar) and large (full-thickness plate) specimens. For the small round-bar specimens rupture occurred at the base metal, while fracture was at the weld metal for large plate specimens. This difference in rupture location was attributed to the stress distribution in the welded joint specimens during the creep process. The stress distribution can be caused by the non-uniformity of strength in the weld metal and the suppression of deformation due to hardening of the heat affected zone in the base metal.
The deformation behaviors of base metal and weld metal in the joint can be estimated by a FEM computation, and it allow us to predict the location of fracture in the weldment by comparison of relafive strength with base and weld metals.

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Using hot-rolled 304 stainless plate (60mm thick) and 308 filler wire, a narrow-gap butt welded joint was prepared by GTAW (gas tungsten arc welding) process. In addition to the conventional round-bar specimens of the base metal and weld metal, the full-thickness joint specimens were prepared and subjected to creep tests at 550°C, from 196 to 294MPa. The creep strain distribution on the surface of each large joint specimen was measured by moiré interferrometry. The hardness of the weld metal at the surface is less than that of the inside which is significantly affected by thermal cycling during welding. This means that the heart of the weld metal is overmatched, but the layers near the front and back surfaces are undermatched. The creep-rupture strength of the large joint is about 85% of that of the overmatched weld metal. The initiation of cracks occurs in the beads at closest to the front and back sides. On the basis of the above observations, it is recommended to have the data of large joint specimens in order to interpret the creep life of the multi-pass welded joints.

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Mild steel was welded in CO₂ atmospheres at pressures between 1 and 6 Kg/cm² abs. using an electrode wire of 1.6 mm diameter, commercially available for CO₂ arc welding, in order to study the effect of ambient gas pressure on the characteristics of an arc, the mode of metal transfer, the geometry, composition and hardness of weld beads and so on.
The results obtained are summarized as follows:
(1) In welding under a shorting-arc condition at 22.5V, 250A,
(a) the maximum arc voltage increases and the duration of short circuiting becomes longer with an increasing ambient gas pressure;
(b) the ambient gas pressure has no significant influence on the melting rate of an electrode wire and the chemical composition of weld metals;
(c) the hardness of weld metals increases with an increasing ambient gas pressure; and
(d) the reinforcement of welds increases with an increasing ambient gas pressure.
(2) In welding under a droplet transfer condition at 35V, 350A,
(a) the melting rate of an electrode wire increases with an increase in the ambient gas pressure; (b) the arc voltage during welding under high pressure atmospheres appears in waves at intervals of some 25Hz, accompanied with many small fluctuations in a wave;
(c) the ambient gas pressure has no significant influence on the chemical composition of weld metals;
(d) the hardness of weld metals decreases with an increasing ambient gas pressure; and
(e) the reinforcement and penetration depth of weld metals increase with an increasing ambient gas pressure.
(3) In welding with 4 mm arc length under a droplet transfer condition at 350A,
(a) manganese and silicon contents of weld metals decrease with an increasing ambient gas pressure;
(b) the arc voltage during welding under high pressure atmospheres appears in waves in the same manner 35V, 350A; and
(c) the hardness of weld metals decreases with an increase of the ambient gas pressure;
(4) No porosity was observed in the weld metals made in the pressurized CO₂ atmospheres.

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An experimental study on thin-walled hybrid plate girders subjected to repeated loading is described.
Six large-sized hybrid plate girders which were fabricated of HT-80 (quenched and tempered high strength steel) at a tension flange, SM-58 at a compression flange and SS-41 at a web were tested under repeated bending.
Parameters investigated in this study were maximum stress, stress range, web slenderness ratio and rigidity ratio of longitudinal stiffener.
Test results were discussed on the observed fatigue crack patterns according to the classification proposed by Toprac, and S-N curves for hybrid girders were plotted and compared with several past research data. Consequently, it has been proved that the stress range is one of the most significant parameters that affect the fatigue strength of hybrid girders, and the fatigue failure can be evaluated well from the crack at the transverse stiffener-to-web fillet weld below the neutral axis (Type 2 crack). A good correlation was observed in the fatigue test results between model specimens with transverse fillet welded attachments and largesized girder specimens, and comparisons with several fatigue data on steel plates with transverse fillet welded attachments showed that SS-41 web is the most economical.

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カリフォルニア大学バークリー校東アジア図書館で行なわれている日本の古地図のデジタル化プロジェクトは同図書館のサイトで一般公開されており,古地図に新たなパースペクティブを与えるものとして,いま世界的な注目を集めている。このサイトの画像は単なるイメージの表示に留まらず,同時に提供されているツールを用いてより有効に地図を活用できるよう配慮されている。またGoogle Earthと古地図との重ね合わせもプロジェクトの一部として進行中である。本稿ではそのプロジェクトの内容,使用しているソフトウエアの利用法,デジタル化を行なうことの意義,影響,そして新たに起きた問題点などについて説明する。

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本稿の目的は，小選挙区比例代表並立制における政党競合の展開を，共時的・通時的の両面からトータルに叙述することである。本稿における主な発見は次の３点にまとめられる。①中選挙区制時代の政党競合のあり方が，新しい選挙制度のあり方を規定しており，それが自民党に有利に働いたこと，②小選挙区比例代表並立制導入後の巨大政党の誕生は，予言の自己成就としての性格を有しており，それが非自民勢力に多大な負荷を与えたこと，③異なる原理を有する小選挙区制と比例代表制を足し合わせた制度である小選挙区比例代表並立制は，政治過程に複雑な力学をもたらしており，それが現在の野党分断現象を生んでいること。同じ小選挙区比例代表並立制であっても，小選挙区の数（比率ではない）がいくつになるかで，政党競合のあり方が大きく変わることを，本稿の内容は示唆している。

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