In recent years, air-spring-type tilting vehicles, which use air springs as the car-body tilt mechanism, have been employed, even in Shinkansen trains, to increase the operation speed on curved ...sections. On a test train running at a speed of about 300 km/h with the tilt mechanism, however, it was found that the car-body roll and lateral vibrations increased in compound curves where the plane and vertical curves overlapped. In this study, an analytical model of the air-spring-type tilting vehicle is developed, and a numerical simulation is carried out to clarify the high-speed curving behavior in a compound curve. Then an antiroll damper, which is installed between the car-body and the existing anti-rolling device, is examined as a countermeasure to reduce car-body vibration. As a result, it is shown that the vibration occurring in the compound curve is caused by the centrifugal force generated by the passage of the train on the vertical curve and the imbalance in stiffness between the left and right air springs during tilting. It is also shown that an antiroll damper has a potential to suppress the increase in car-body vibration in compound curves.
Sixteen cases of ischemic colitis (IC), consisting of 14 cases of transient type and z cases of stenotic type, were presented. The course of the disease were endoscopically observed. The results were ...as follows : 1) IC was seen mainly in the elderly persons. Abdominal pain and bloody diarrhea were typical clinical symptoms. 2) The colonoscopic findings of IC of transient type were characteristic and diagnostic. Four stages were recognized according to the endoscopical features. (a) Stage I : (Within 3 days after the onset). Nodular edematous-reddish mucosa due to edema and/or hemorrhage in the submucosa was the earliest change. (b) Stage II: (4-7 days after the onset). Edematous-reddish areas seen in the stage I were fused longitudinaly, followed by formation of linear ulcers. (c) Stage III : (8-14 days after the onset). The linear ulcers and/or linear ulcer scars were seen in all cases. (d) Stage IV : (15-54 days after the onset). Only linear ulcer scars were seen. 3) Gross pathology had proved that linear ulcers were seen along the teniae coli which formed three seperate bands. Endoscopical findings of this investigation also proved this. However, it is obscure why the linear ulcers were seen along the teniae coli. 4) Repeated colonoscopical examination in the early stage were very helpful in the observation of the course of these characteristic lesions. 5) Two cases of stricture formation were recognized to diminish the grade of stenosis by examinations performed on the 56th and 87th day after the onset, respectively. In one case, a barium enema a year after the onset disclosed no evidence of stricture.
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