• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제50권8호
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• pp.392-401
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• 2001

This paper presents the single-stage high power factor AC to DC converter operated in active-clamp mode. The proposed converter is added active-clamping circuit to boost-flyback single-stage power factor corrected power supply. The active-clamping circuit limits voltage spikes, recycles the energy trapped in the leakage inductance, and provides a mechanism for achieving soft switching of the electronic switches to reduce the switching loss. The auxiliary switch of active-clamping circuit uses the same control and driver circuit as the main switch to reduce the additional cost and size. To verify the performance of the proposed converter, a 100W converter has been designed. The proposed converter gives good power factor correction, low line current harmonic distortions, and tight output voltage regulation, as used unity power factor.

• 한국구조물진단유지관리공학회 논문집
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• 제10권1호
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• pp.131-138
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• 2006

일정한 크기의 마찰력을 도입한 가새(FSB)는 에너지를 소산시키는 효과적인 구조 부재이며, 가새의 축력이 마찰력을 넘지 않을 때까지만 탄성 거동을 한다. 본 연구에서는 FSB 개념을 보다 확장시켜서 가새를 죄는 마찰력의 크기를 능동적으로 변화시킬 수 있는 능동 조임 마찰 가새(AFSB)를 착상하여 단자유도 구조물에 적용하고 조화 하중으로 기진시켜 그 거동을 시뮬레이션 하여 FSB와 비교 분석해본다. 이를 위해 간단하고 효과적인 알고리즘을 개발해보았다. 연구 결과, 지반 가속도 값이 그다지 크지 않은 경우, AFSB는 초기에 오우버슈팅이 발생하는 문제만 제외하고 FSB에 비해 효과적으로 진폭과 밑면 전단력을 감소시켰다.

• Journal of Pharmaceutical Investigation
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• 제2권1호
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• pp.18-30
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• 1972

Renal pathways for excretion of sulfadiazine has been studied by standard clearance technique in the rabbit. 1. Large part of sulfadiazine filtered in the glomeruli is reabsorbed in the tubules, as visualized from the fact that Csd (clearance of sulfadiazine) amounts only a fraction of simultaneously measured Ccr (GFR). 2. Csd changed linearly with the rate of urine flow, whether it is increased by the duir etics or decreased by clamping u reter. 3. Csd remained unchanged until the plasma level of the Csdremained unchanged drug reached 10.0 mg%, and the amount transported in the tubules increased linearly with the increase in the load, exhibiting No maximum capacity for transport. 4. Csd was increased by 2,4-dinitrophenol which is an uncoupling agent of oxidative phosphorylation and decreased by probenecid which is on uricosuric agent. 5. During sodium bicarbonate infusion net secretion of sulfadiazine by tubules observed. All the evidences obtained in the rabbit indicated that sulfadiazine was reabsorbed by active, energy-requiring, or passive, simple diffusion, process, and secreted simultaneously by a probenecid-sensitive, active procss.

• The Korean Journal of Physiology
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• 제25권2호
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• pp.171-177
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• 1991

This study was carried out to determine effect of acute renal ischemia on transport function of organic cation, tetraethylammonium (TEA), in rabbit kidney proximal tubule. Clamping of the renal artery for 30 and 60 min produced a polyuria which was accompanied by an increase in $Na^+$ excretion. The capacity of kidney cortical slices to accumulate TEA was increased after 30 and 60 min of ischemia. When blood flow was restored for 30 min after 30 and 60 min of ischemia, the augmented TEA uptake was recovered to the control values. Oxygen consumption of cortical slices was stimulated after 30 min of ischemia, whereas it was not altered by 60 min of ischemia. A 90-min ischemia produced a significant inhibition of TEA uptake and tissue oxygen consumption. These results suggest that the basolateral transport system for organic cation persists after ischemic periods of 60 min despite evidence that tubular reabsorptive mechanism of $Na^+$ and water is markedly impaired. This may indicate that the active secretory systems of proximal tubule are more resistant to ischemic injury than the reabsorptive systems.