용해성 poly(dimethy-co-diphenylsilane)공중합체의 특성과 열분해에 관한 연구

강필현,양현수,황택성,김봉만,권오현 忠南大學校 産業技術硏究所 1993 산업기술연구논문집 Vol.8 No.2

Soluble poly(dimethyl-co-diphenylsilane)copolymer,[(SiMe₂)x(SiPh₂)1-x]n where x=0.5 to 0.9., was synthesized by condensation polymerization of dimethyldichlorosilane and diphenyldichlorosilane in xylene. In the TG analysis of the copolymer, weight loss started at 170℃ and the weight residue at 1000℃ was 32%. The copolymer was stabilized by thermal oxidation at 80 to 110℃ for 5 hr. in air, and its thermal stability increased as the temperature increased. The copolymer heat treated above 700℃ showed no organic bonds of C-H and Si-CH₃. while Si-C, and Si-O large bonds were observed. Amorphous SiC was obtained by pyrolysis at 1000℃ and β-SiC at 1200 to 1400℃, in which a better crystallinity of β-SiC was observed at a higher temperature.

Zn를 첨가한 고온초전도체 Y Pr Ba₂Cu₃O 의 Raman 분석

강재필,김성재,박현진,노태호,송승기,박영민,전인 明知大學校 自然科學硏究所 1997 자연과학논문집 Vol.15 No.-

고온초전도제 Y Pr Ba₂Cu₃O 에 Zn를 첨가(x=0.00, 0.05, 0.10, 0.15, 0.20)하여 전이온도 측정, X-ray회절 실험과 Raman 실험을 하였다. Raman 측정결과 다섯 개의 시료가 일반적인 YBCO 초천도체의 Raman 스펙트럼에서 존재하는 다섯 개의 대칭활성모드(115cm¹,150cm¹.340cm¹,440cm¹,504cm¹)가 관측되었다. 이것은 Cu 와 관련된 대칭활성모드의 주파수가 모두 저주파 변위를 나타내어 Zn가 Cu(1)과 Cu(2)에 치환되었음을 의미한다. 저주파 변위 정도는 Zn에 거의 무관했으나, Raman 스펙트럼의 각 피이크의 선폭은 치환된 Zn에 의해 증가했다. 이 결과는 Zn가 Cu자리에 어느 한계 이상은 치환되지 못하고 시료 내에서 불순물상을 형성함을 나타내는 것이다. We measured transition temperature, X-ray diffraction pattern and Raman spectra of Zn added(x=0.00, 0.05, 0.10, 0.15, 0.20) high-T superconductor Y Pr Ba₂Cu₃O All samples have been observed five symmetric activity modes(115cm,150cm¹.340cm¹,440cm¹,504cm¹)which exist in Raman spectrum of general YBCO superconductor. This means Zn is substituted for Cu(1) and Cu(2) due to the fact that symmetric activity mode frequency related with Cu shows low-frequency shift. The degree of low-frequency shift was nearly independent on Zn but line width of Raman spectra peaks were increased by the substituted Zn. This results shows that Zn does not be substituted for Cu-site more than limit value and formes impurity phase in the sample.

척추 유합술에서 자가 이식골과 동종 이식골의 비교 : 증례보고 A Case Report

정필현,김태훈,채동주,문상호,박윤근,배호균,이재학 東國大學校 1999 東國論叢 Vol.38 No.-

척추 유합술에 있어서 자가 골 이식이 가장 좋은 방법으로 알려져 있지만 수술 시간과 실혈량이 늘어나고 공여부의 통증 및 감염의 위험등 단점으로 동종 골 이식도 많이 사용되어지고 있다. 이러한 동종 이식골의 효용성에 대해서 많은 논란이 있어온 것은 사실이나 여러 변수들, 즉 나이, 성별, 흡연력, 수술의 종류등에 따른 영향을 완전히 배제시키지 못하여 순전히 동종 이식골과 자가 이식골간의 비교가 어려웠다. 저자들은 척추관 협착증으로 후방 감압술 및 후방 기기 고정술, 후외방 골 이식술을 받은 환자에게서 우측은 자가 이식골, 좌측은 동종이식골로 골 이식을 시행한 후 4년 추시에서 자가 골 이식한 부위는 견고한 골유합 소견을 보였으나 동종골 이식 부위는 이식 골이 모두 흡수되는 소견을 체험하여 같은 조건하에서 자가 이식골이 동종 이식골보다 골유합체의 형성에 있어서 더 우수하다고 생각한다. Posterior decompression, spinal instrumentation and bone grafting are the standard operative treatment method of spinal stenosis and other low back disorders. Although autograft bone is considered the standard in performing fusion of the bone, allografts are recommended as an alternative bone graft agent becaue of the lack of complications at the donor site such as infection, increased blood loss and prolonged operative time Autografts have the other limitations because of inadequate quality and quantity. Many investigators have compared autografts and allografts in posterior spinal fusion, and there are proponents as well as opponents of allograft use. Numerous factors are thought to affect fusion, including age, sex, nutritional status, associated disease, type of fusion, length of fusion, types of instrumentation and smoking status. The validity of comparison studies between allografts and autografts is questionable when these variables are not controlled. We describe a man who had a spinal stenosis at the level of L4-5 and L5-S1. He was operated with posterior decompression, spinal instrumentation and underwent a posterolateral bone graft, comparing autografts and allografts in the same patient. At 4-year follow up, autografts have a solid union but allografts are resorbed completely.

반도체 메모리에 사용되는 전압발생기의 펌핑 커패시터 개선

김필중,구대성,윤중현,김종빈 조선대학교 전자정보통신연구소 2002 電子情報通信硏究所論文誌 Vol.5 No.1

In semiconductor memory, the kinds of voltage generator are high voltage generator, negative voltage generator, drain voltage generator and etc. The relevant circuits supported voltage generator, are clock generator, sense amplifier, voltage regulator and etc. The voltage generator consists of MOS diodes and MOS capacitors. To get the out voltage with sufficient charge, the MOS capacitors are big size. These MOS transistors can be adapted only on the EEPROM process. Thus, in this study, we designed stacked metal capacitor. This capacitor is small size bat can get capacitance. This capacitor is designed to comb type using metal-line and poly-line. The size of designed capacitor is 208×52 ㎛2 and the capacitance is about 4pF. The stacked metal capacitor can get much capacitance of 5~6 times than single plane capacitor. Also this capacitor will be easy adapted in sub-micro process technology of semiconductor memory. And this capacitor can be adapted on all memory process.

19세 환자의 골성 변화를 동반한 선천성 사경의 치료 : 증례보고

정필현,배성한,문상호 東國大學校 1998 東國論叢 Vol.37 No.-

Congenital muscular torticollis has been recognized for centuries and has been the subject of many reports. Controversy remains regarding the indications for conservative or operative treatment, the regarding the indications for conservative or operative treatment, the surgical procedure of choice and the ultimate results. The optimal time for surgery is between 1 and 4 years and most children treated before the age of 1 year respond well to conservative treatment. However, there has been very limited experience in terms of what kind of results one can expect in the management of the older child. The authors reviewed a case of neglected 19-year-old congenital muscular torticollis who has fibrotic band, bony deformity on clavicle, facial asymmetry and cervical scoliosis due to contracture of sternocleidomastoid muscle. Although articles showed that the best results can be expected in children<4 years of age, we believe that surgery should be offered to those of older age as well. Although facial asymmetry is unlikely to improve, these patients benefit from tilt and have increased range of neck movement by surgery, physiotherapy, short-term Halter traction and cervical collar.

비확공성 골수강내 금속정을 이용한 폐쇄성 경골 간부 골절의 치료

정필현,황정수,채동주,문상호 東國大學校 1998 東國論叢 Vol.37 No.-

Most of closed fractures of the tibial shaft can be treated successfully with medullary nails. Reamed intramedullary nailing technique has become a good alternative method in treating the close tibial fracture. Unreamed interlocking intramedullary nailing has been employed successfully in the treatment of open tibial fractures. This study was undertaken to evaluate the result of interlocking intramedullary nailing without reaming in the treatment of closed fractures of the tibial shaft. From 1995 through 1998, fifty four cases of the closed, displace tibial fractures were treated by an unreamed intramedullary nailing and the average follow-up period was 1 year and 5 months(ranged from 12 months to 27 months). The results were as follows : 1. Fifty four cases were treated with closed, unreamed nailing technique and the nail which has 1mm smaller diameter than isthmic width of unaffected tibia was choosen. 2. The average time to bony union was achieved at 17 weeks without abundant periosteal b callus formation. 3. Eight tibiae were required the additional procedure such as autogenous bone graft, skin graft or local skin flap. We also have observed the screw breakage of ten tibiae but there were no intraoperative jamming or incarceration and no significant complicaton such as bending or breakage of the nail, shortening or non-union of the fractures. In conclusion, unreamed technique is an attractive method to treat the close, displaced fractures of the tibial shaft. 경골 간부 골절의 치료에 있어서 견고한 내 고정으로 조기 관절운동 및 체중 부하를 통해 골절 유합 및 기능 회복을 도모할 수 있는 골수강내 금속정 고정술이 널리 사용되어지고 있다. 골수강내 금속정술의 장점은 술 후 조기 관절운동과 체중 부하가 가능하여 이환율(morbidity)을 감소시키며 불유합의 발생률이 낮아는 것이다. 경골 간부 골절의 치료에 있어서 비확공성 금속정 고정술은 주로 심한 연부 조직 손상을 동반한 골절 및 개방성 골절의 치료에 적용되어지고 있으며, 대부분의 폐쇄성 경골 간부 골절의 치료로는 골수강 확공 후 골수강을 충만시키는 금속정을 삽입하는 확공정 금속정 고정술이 시행되어지고 있는 경향이다. 저자들은 폐쇄성 경골 간부 골절에 대해서 비확공성 금속정 고정술의 유용성 여부를 알아보기 위해서 동국대학교 의과대학 정형외과학교실에서 치료했던 54례를 평균 1년 5개월 추시하여 골 유합 기간, 합병증의 발생에 대해서 분석하였다. 본 연구에서 비확공성 금속정 고정술시 골 유합 기간은 확공성 금속정 고정술시와 비교하여 유의한 차이가 없음을 알 수 있었으며, 확공을 하지 않음으로써 발생할 수 있는 jamming이나 가는 직경의 금속정을 선택함으로써 우려되는 금속정의 휨, 부러짐 등의 합병증은 발생하지 않았다. 결론적으로 폐쇄성 경골 간부 골절의 치료에 있어서도 비확공성 골수강내 금속정 고정술은 유용한 방법으로 사료된다.

뇌동맥류 수술환자의 정신신경학적 분석

정현태,박순필,김상진,도종웅 대한신경외과학회 1987 Journal of Korean neurosurgical society Vol.16 No.4

The mortality rate of aneurysmal surgery had recently been reduced remarkably due to mordern microsurgical technique and refinement of the timing of operation. Despite recovery without neurological deficits, many patients remain with emotional and psychological sequelae postoperatively. We evaluated 33 patients, operated on intracranial aneurysm for recent 2 years, about quality of life and degree of cognitive function. For proper evaluation of outcome of aneurysmal surgery, in addition to the neurological outcome, psychological aspects must be considered.

77K와 상온에서 CO(NH₂)₂의 ¹⁴N Pulsed NQR 연구

강재필,박영민,전인,김성재,최숙자,박현진,송승기,서용문 명지대학교 자연과학연구소 1996 자연과학논문집 Vol.13 No.-

77K와 상온에서 CO(NH₂)₂분말 시료의 ??N Pulsed NQR실험을 하여 위와 아래 공명 진동수, 핵 사중극 결합상수, 비대칭 인자, 스핀-스핀 완화시간, 결정 격자 진동에서의 평균 비틀림 진동수, 진동자의 관성 모먼트 등을 구하였다. 공명 진동수의 온도 의존성은 전형적인 Bayer이론의 격자 진동에 의한 주파수 변화를 보였다. Bayer-Kushida이론의 고온근사식을 실험값에 적용하여 OK에서 공명 진동수 ν??와 ν??를 구했으며, 77K와 상온에서의 스핀-스핀 완화시간 T₂를 관측했다. 상온에서 T₂의 감소는 결정 내의 reorientation motion과 관련이 있을 것으로 보인다. Upper and lower resonance frequencies, nuclear quadrupole coupling constants, asymmetry parameters, spin-spin relaxation time, average torsional frequency in the crystal lattice motion and moment of inertia in the oscillator are found for CO(NH₂)₂powder sample by using ??N Pulsed NQR(Nuclear Quadrupole Resonance) technique at 77K and room temperature. Temperature dependence of resonance frequencies showed frequency variation in agreement with the typical Bayer's theory in lattice motion. Resonance frequencies ν?? and ν?? at OK were obtained by fitting the high temperature approximation of Bayer-Kushida theory to the experimental data and spin-spin relaxation time (T₂) was observed at 77K and room temperature. Decrease of T₂at room temperature was explained by the effect of reorientational motion in the crystal lattice.

채널간 파장간격 Δλ=2nm인 4채널 WDM 광소자 설계 및 특성에 관한 연구

라경태,김필중,윤중현,김상덕,김종빈 조선대학교 전자정보통신연구소 2000 電子情報通信硏究所論文誌 Vol.3 No.1

WDM/FDM is expected to be a basic technology for constructing cost-effectively high-speed and large capacity optical networks in the future, device technologies for supporting WDM/FDM function have begun to be studied actively In this paper, we proposed a 4 channel WDM optical device and simulated it based on Mach-Zehnder Interferometer with channel spacing Δλ=2nm at central wavelength λ =1 55㎛. So, we assumed initial condition that core dimension, 6㎛×6㎛, core index, 1 455, clad index, 1 444 at wavelength 1 55㎛, and the separation between channel waveguides, 4㎛ From this condition, we analyzed a channel waveguide and optical coupler(3㏈ coupler), simulated a single Mach-Zehnder Interferometer, and then designed a 4 channel WDM

V₂O-B₂O₃-PbO 유리의 전자 상자성 공명연구

노태호,전인,박영민,강재필,김성재,박현진,송승기 명지대학교 자연과학연구소 1996 자연과학논문집 Vol.14 No.-

V₂O??-B₂O₃-PbO 유리의 VO??에 관한 전자 상자성 (EPR) 스펙트럼으 연구하였으며, vanadium이온의 스핀해밀토니안 상수들을 구하였다. 유리시료안의 V₂O??양을 증가시킴에 따라 g??과 g??값은 증가하였으나 A??과 A??값은 감소하였다. 이는 V₂O??수가 증가하면 동일 평면상의 vanadium과 oxygen배위간 결합의 공유성이 증가함을 의미한다. 유리내의 vanadium 4가이온은 정방형 일그러진 8면체를 한 vanadyl착물로 존재한다. Electron Paranmagnetic Resonance(EPR) SPECTRA OF (VO)?? in V₂O??-B₂O₃-PbO glasses have been studied and spin hamiltonian paramenters of vanadium ion have been calculated. It is found that the value of g??and g?? increases while the value of A?? and A?? decreases with an increase of V₂O?? content in the glass samples, showing that the covalency in the in-plane vanadium -oxygen ligand bonds increase with increasing the concentration of V₂O??. The tetravalent vanadium ions exist as vanadyl complexes with tetragonally distorted octahedral sites in the glasses.