The die quenching of ultrahigh-strength steel sheets in hot stamping using rapid resistance heating was experimentally investigated. A 1.2 mm-thick steel sheet with an ultimate tensile strength of 980 MPa was used as an experimental material. A test piece 130mm long and 20mm wide was resistance-heated at various temperatures above the Ac₁ point with an AC power supply and, immediately after the completion of the electrification, the heated test piece was quenched by sandwiching with cold steel blocks 115mm long, 65mm wide and 30mm thick and holding for a predetermined time. The quenched test piece was evaluated by optical microstructure observation and hardness and tensile tests. The influence of material conditions on the quenching performance of the annealed sheets was also examined. Our findings are as follows. (1) The sheets resistance-heated above the Ac₃ point and properly die-quenched showed a high hardness value of 495 HV, which is 1.6 times as large as the 312 HV of the original sheet, and an ultimate tensile strength of above 1400 MPa. (2) The use of an annealed sheet with coarse grain structures is not suitable for die quenching using rapid resistance heating. (3) The die quenching conducted on a trial basis in hot hat-shaped bending was successful and the hardness of the formed part increased by approximately 1.6 times that of the blank sheet.

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A resistance heating process of a side wall for warm and hot spline forming of cups was developed to manufacture high tensile strength steel gears. The side wall of the cup was heated by the electrification to decrease the forming load and to increase the formability. Since the cross-sectional area of the side wall having a uniform wall thickness is uniform, the heating of the side wall by the resistance heating becomes uniform. The inhomogeneous contact between the electrode and side wall was improved by inserting copper foils in the interface, and thus the temperature distribution in the hoop direction became uniform. The uniformity of the temperature distribution in the axial direction was improved by decreasing the total area of the contact between the electrode and side wall and by increasing the number of contacts. The side wall of the cup was successfully shaped into a gear by the warm and hot spline forming process using resistance heating.

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A hot spline forming process of an ultra high strength steel gear drum was developed to manufacture high tensile strength steel spur gears. Since the cross-sectional area of a side wall of a cup formed by cold deep drawing and ironing was uniform, the side wall formed put between the upper and lower electrodes was uniformly heated by the electrification in the axial direction. The uniformity of the temperature was improved by inserting a copper foil between the electrode and the side wall, and by decreasing the area of contact. Although the high strength steel cup was fractured by cold spline forming, a spur gear was successfully manufactured by the hot spline forming. The load for a hot spline forming of the high strength steel gear drum is similar to that for the cold forming of a mild steel gear drum, and the accuracy of teeth was improved. In addition, the formed gear drum was hardened by die quenching.

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For the past decade, hot stamping technology has been gradually applied to the production of super high strength automotive parts. Although auto-parts such as bumpers, door impact beams, center pillar reinforces have been produced by hot stamping and installed in many cars all over the world, this promising technology has not spread as much as was expected. One of the major reasons is the high production costs owing to the low productivity of this technology. In this study, we investigate the effect of forming conditions on the shape fixability of hot stamped hat-type parts. On the basis of the obtained results, we introduce a new hot-stamping technology characterized by a markedly high productivity.

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The features of sheared edges in warm and hot punching of an ultra high strength steel sheet using resistance heating were examined. As the heating temperature increased, the depth of the shiny burnished surface on the sheared edge increased and that of the rough fracture surface decreased. The rollover depth and burr height of the sheared edge markedly increased from about 800°C. The roughness level of the fracture surface became high above 650°C, whereas that of the burnished surface was almost constant. The punching load was considerably reduced by the heating, i.e., 40% of the cold punching load at 650°C and 15% at 1070°C. The effects of the punching speed and the clearance between the punch and the die on the surface quality of the sheared edge became marked at high temperatures. It was found that the warm and hot shearing of ultra high strength steel sheets is effective for improving the surface quality of the sheared edge and in reducing the shearing load.

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授乳期の母豚は自身の維持成長に加えて子豚に対する乳生産を行うため，多くの栄養摂取が必要となる。飼料摂取量向上の対策として，母豚が常時飼料を摂取することができる不断給餌が挙げられる。本研究では，不断給餌器を用いた不断給餌が授乳中母豚の飼料摂取量およびその後の生産性に与える影響を調査することを目的とした。本研究はランドレース種と大ヨークシャー種の交雑種母豚を約350頭飼養している一般生産農場で実施した。2014年9月11∼13日に分娩した3産以上の母豚19頭を対象として，これらの母豚を自由摂食群（不断給餌器を用いた自由摂食群:n＝10）と従来給餌群（一日二回の従来給餌:n＝9）に無作為に分類した。試験開始日は分娩後4日目とし，離乳日（分娩後20日目）までの17日間，飼料摂取量を毎日観察した。また生産成績として，平均離乳子豚体重および離乳後初回交配日数を調査した。試験期間17日間における総飼料摂取量の平均（±SEM）は105.0±4.8 kgであり，自由摂食群の方が従来給餌群よりも高い傾向にあったが（111.5±7.6 vs. 97.9±4.8 kg;P＝0.16），本解析の検出力は0.235であった。生産成績に関して自由摂食群は従来給餌群よりも平均離乳子豚体重が大きく（9.1±0.1 kg vs. 7.8±0.1 kg;P<0.05），離乳後初回交配日数が短かった（4.8±0.1日 vs. 5.4±0.2日;P<0.05）。本研究では，検出力が低い中，不断給餌器を用いた不断給餌により飼料摂取量が増加することが示唆され，またその効果として，その後の生産成績が向上する可能性が示唆された。

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In this paper I studied on characteristics of filled flow in siphon drainage system. To know how washbasin trap's water seal are affected by self-siphonage, we discharged water by filled flow and observed the state of water seal. We used a S-trap and a P-trap for experiment, and high speed camera for observation.

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本論文では，ゲーミフィケーションと心理学の共通性について考察する.日本ゲーミフィケーション協会の提唱するゲーミフィケーション 6 要素の解説と，対応するサービスや商品の事例を紹介する.さらに，ゲーミフィケーション 6 要素に対応する 11 個の心理学用語を紹介する.ゲーミフィケーションと心理学は，人の心理を操り，行動や意欲を変化させる手法という共通性を持っていると考える.

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This study aimed to accumulate the basic data concerned about the design of the siphonic drainage system. We carried out the verification experiments about the flow characteristic in the following circumstances in the cases that the convex rising elbow pipe was connected to the outlet part of the horizontal drain pipe or it wasn't connected. And in addition, we also examined on experiment about the effectiveness of the formula derived from the Bernoulli's equation to calculate the pressure in the pipes when the siphon effect has been started.

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一般的に、従来の重力式排水システムによる配管では接続箇所が多く漏水の恐れがあり、勾配を必要とするため設計自由度が低い。そこで管内を満流にし、生じた負圧を搬送力とするサイホン排水システムの適用が期待されている。空調ドレン配管においてはドレン排水の流量に対応した極小径配管を用いることにより、省スペースで設置でき、他配管などを跨いで配管することも可能である。本研究では理論値との比較と流量線図の作成を行った。また、測定開始からサイホン現象により負圧が生じるまでの時間の測定も併せて行った。

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