YAG-laser machining of TiO2 ceramics and its mechanical property

Single-shot processing and cutting processing were performed on both CIP and HIP-treated TiO2 ceramics using YAG laser, and the basic mechanical properties by the processing were investigated. Increasing the pulse height and pulse width of the machining shot pulse increases the laser beam power and energy, and basically increases the diameter and depth of the beam hole. This relationship holds true for CIP-treated TiO2, but it is not always true for HIP-treated high-density products, which sometimes cracked. In cutting processing, the hardness of the machined surface was maintained at about 80% of that of the non-machined surface. The surface roughness of the machined surface was greatly deteriorated.departmental bulletin pape

コウイカ類のターゲットストレングス

編集：水産総合研究センター　水産工学研究所articl

Fundamental study of YAG laser processing of various ceramics

In this study, YAG laser beams with energies of about 3.8 J/shot for cutting and 6.05 J/shot for welding were applied to various ceramics such as oxides, nitrides, carbides, borides and their composites. The possibility of laser processing for ceramics and the ceramics suitable for cutting and welding were investigated with one shot irradiation. As a result, the ceramics considered to be suitable for laser processing (cutting and welding) are PLS(pressureless sintering)-TiO2, HP(hot-press)-TiB2-B4C system, HP-TiN-B4C system and PLS-Si3N4. Otherwise, HP and PLS-TiB2-ZrB2 systems are considered unsuitable ceramics.departmental bulletin pape

YAG laser cutting of Si3N4, AlN, SiC ceramics and its mechanical property

Si3N4, AlN and SiC ceramics with a relative density of 96.5% or more were processed by YAG laser cutting, and the change in strength due to the processing was evaluated. When a single laser beam was irradiated, the beam depth ? increased in proportion to the energy E [J] of the laser beam. The relationship between E and ? is about 1J→0.6~0.8mm, 2J→0.9~1.1mm. The beam-hole diameter with conical shape was 0.15 to 0.22 mm at the irradiated surface. The Vickers hardness of the processed surface decreased to about 13-22%. The 3-point bending strength decreased to 33-45%. The surface roughness decreased greatly from 1/62 to 1/146. From the observation of the structure of the irradiated cross section, the structure melted by heat of laser beam was observed in Si3N4 and AlN, and the sintered structure with traces of processing was observed in SiC.departmental bulletin pape

当科うつ病入院患者における治療経過中の血圧変動

うつ病と高血圧などの心血管系疾患ついては関連を示唆する多くの報告があるが、一定の見解には至っていない。そこで今回我々は、抑うつ症状の悪化を契機に当科に入院した大うつ病性障害患者12名の入院後1週間の平均血圧と症状改善後の安定期の平均血圧を調査・検討した。その結果、全12例の平均では入院時（117/71mmHg）と安定期（114/71mmHg）で血圧に差はなかったが、単一エピソード群（3名：131/78→ 105/67）で反復性群（9名：112/68→ 116/72）と比較して入院時に上昇していた血圧が安定期には低下する傾向が認められた。また、高齢の単一エピソード群には症状の悪化と血圧の上昇が相関している症例も存在した。以上から、高齢の初発例では血圧上昇を起こしやすい可能性も考えられ、診察する際には留意する必要があると思われた

公開講座「モノづくり体験実習―特殊鋳造で野菜の形の文鎮を作ろう―」の実施報告

applicationdepartmental bulletin pape

A Case of Strangulated Ileus Due to Intersigmoid Hernia Treated by Laparoscopic Surgery.

A 50-year-old woman visited our hospital in emergency because of sudden lower abdominal pain. There was tenderness in the left lower abdomen. An abdominal computed tomography scan showed a loop-shaped small bowel in the left lower abdomen. A strangulated ileus due to an internal hernia was diagnosed and emergency laparoscopic surgery was performed 21 hours after the onset of symptoms. The laparoscopic findings showed that the small bowe1 had herniated into the intersigmoid fossa. We diagnosed intersigmoid hernia. The incarceration was reduced by laparoscopic maneuver. Since the incarcerated portion of the small bowel was viable, we did not remove it. The postoperative course was uneventful. The patient was discharged from our hospital on the fifth day after surgery and we followed the patient 47 days after surgery. Intersigmoid hernia is very rare. We report our experience of successful laparoscopic diagnosis and treatment for intersigmoid hernia along with a literature revlew