• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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• pp.418-421
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• 2001

The ceramic filters were developed using technology similar to that of quartz crystal and electromechanical filter. However, the key to this development involved the theoretical analysis of vibration modes and material improvements of piezoelectric ceramics. The primary application of ceramic filters has been for consumer-market use. Accordingly, a major emhpasis has involved mass production technology, leading to low-priced devices. A typical ceramic filter includes monolithic resonators and capacitors packaged in unique configurations. Nakazawa developed a double-mode resonator as two acoustically coupled single resonators. And he developed 10.7MHz crystal filters using multi-energy trapping mode of thickness shear vibration. He succeeded in realizing a two-pole band pass filter response without external inductance by splitting a dot electrode to creat coupled symmetric and antisymmetric vibration modes. Accordingly, the simulation for ceramic filter were important. So that, this paper were investigated the pass frequency of filter on the electrode length and thickness of ceramic.

• 대한수의학회지
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• 제38권1호
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• pp.183-199
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• 1998

The effects of electroacupuncture(EA) on gastrointestinal motility were investigated in 6 horses. Three acupuncture points ; Guan Yuan Shu(BL-26), Wei Shu(BL-21) and Da Chang Shu(BL-25) were stimulated for 20 minutes by EA at separate occasions under varying condition ; 2V-1Hz, 2V-5Hz, 2V-30Hz, 4V-1Hz, 4V-5Hz and 4V-30Hz. Myoelectric activity of stomach and cecum was monitored to investigate the gastrointestinal motility. Electromyogram(EMG) recordings were carried out before, 0, 20 minutes after and 40 minutes after the EA stimulation. EMG bipolar electrode was surgically implanted in seromuscular layer of greater curvature in the stomach and between medial band and ventral band in the cecum. The EA stimulation and monitoring were not commenced until 15 days after electrode implantation. The EA stimulation of Wei Shu influenced on stomach motility and that of Da Chang Shu on, cecum motility. However, the EA stimulation of Guan Yuan Shu influenced on both the stomach and the cecum motility. The myoelectrical spike burst amplitude of the stomach and the cecum was significantly(p<0.05) increased by 2V-1Hz stimulation, but the myoelectrical spike burst frequence of the stomach and the cecum was significantly decreased by 2V-30Hz or 4V-30Hz stimulation. The myoelectrical spike burst duration of the stomach and the cecum was significantly lengthened by 4V-30Hz and 2V or 4V-30Hz stimulation, respectively.

• 식물조직배양학회지
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• 제28권6호
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• pp.297-304
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• 2001

현삼의 기내배양에서 TDZ처리가 비교적 재분화에 효율적이었고 형질전환 식물체를 선발하기 위하여 선발표지 유전자로 사용되는 NPTII gene이 항생제 kanamycin에 대한 저항성은 50 mg/L가 적당하였다. 선발배지에서 자란 현삼 식물체에서 DNA를 추출하여 PCR 분석을 통하여 특정 유전자 Gh-5 gene을 검정한 결과 형질전환되지 않은 식물체에서는 볼수가 없는 988 bp의 band가 형질전환된 식물체에서는 관찰되어 GST 유전자가 현삼의 염색체 안으로 삽입되었음을 확인하였다. 형질전환 효율 증진을 위하여 선발과정에서 암상태를 30일까지 유지할 경우 높은 형질전환 효율을 나타내었으나 그 이상의 처리는 오히려 형질전환 효율이 감소하는 결과를 나타내었다 (Table 5). 형질전환 식물체에서 GST의 활성이 형질전환 되지 않은 식물체의 2배로 나타났고 유도체의 적정 처리 농도는 50$\mu$M이며 유도체 처리 시간에 따라서는 12시간까지는 점차적으로 높아지는 경향이었으나 그 이상의 시간에서는 활성이 저하됨이 확인되었다. Fungus 피검균인 Asperigillus awamori에서 6, 12시간 처리 시 비교적 높은 활성을 보여주었으며 그 이상의 시간처리에서는 명확한 균사 억제를 나타내지 못하였으며, 특히 12시간에서 상대적으로 높은 활성을 나타내었다. Cladosporium herbarum에서 형질전환된 식물체의 활성이 훨씬 높게 나타났으며 6시간 처리에서 다른 처리에 비하여 높은 활성을 나타내었다. 피검균인 Saccharomyces cerevisiae에서는 형질전환 식물체에서 높은 활성을 보여주었으며 6, 12시간 처리에서 비슷하게 높은 활성을 보여 주었다. 박테리아 피검균 Bacillus subtillis에서는 50$\mu$M 이하의 유도체 처리에서 비교적 높은 활성을 나타내었다.