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Trichlorosilane 의 환원에 의한 고순도 Silicon 제조
이종화,주웅길,고경신 대한금속재료학회(대한금속학회) 1976 대한금속·재료학회지 Vol.14 No.1
Among the several known processes of semiconductor-grade silicon production, the hydrogen reduction of trichlosilane (TCS) is found to be the most convenient and economical method. In this study of high purity silicon production, the open tube flow process is used to reduce TCS with hydrogen. 99.9% pure TCS, manufactured by Ventron, is distilled for the starting material in the reduction. The distilled TCS is vaporized by bubbling at 0℃ with small quantity of hydrogen in a quartz tube. The resultant yield is compared with the theoretical one calculated thermodynamically. The yield of silicon is 60-70% at the optimum condition of 1100℃ reaction temperature and 60-100 mole ratio of hydrogen to TCS. Surface of the deposited silicon, a polycrystalline dense mass of lustrous appearance, is treated with hydrofluoric acid. By the emission spectroscopy the purity of silicon product is determined to be higher than 99.999%.
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이종화,신윤권 대한전자공학회 1998 電子工學會論文誌, D Vol.d35 No.4
A program was developed to analyze the electrical characteristics and harmonic distrotion in a two-dimensional silicon BJT. The finite difference equations of the small signal and its second and thired harmonics for basic semiconductor equations are formulated treating the nonlinearity and time dependence with Volterra series and Taylor series. The soluations for three sets of simultaneous equations were obtained sequantially by a decoupled iteration method and each set was solved by a modified Stone's algorithm. Distortion magins and ac parameters such as input impedance and current gains are calculated with frequency and load resistance as parameters. The distortion margin vs. load resistancecurves show cancellation minima when the pahse of output voltage shifts. It is shown that the distortionof small signal characteristics can be reduced by reducing the base width, increasing the emitter stripe length and reducing the collector epitaxial layer doping concentration in the silicon BJT structure. The simulation program called TRADAP can be used for the design and optimization of transistors and circuits as well as for the calculation of small signal and distortion solutions.
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Periodic Lateralized Epileptilform Discharges의 임상적 의의와 뇌영상검사와의 상관성에 관한 연구
이종화,박은영,김남수,설인준 대한소아청소년과학회 2000 Clinical and Experimental Pediatrics (CEP) Vol.43 No.3
목 적 : Periodic lateralized epileptiform discharges (PLEDs)는 주기적인 혹은 반주기적인 형태로 나타나는 편측 또는 국소성의 중등도나 고전위의 극서파복합으로 1964년 Chatrian 등에 의해 처음 기술되었다. 이에 저자들은 소아에서 PLEDs가 가지는 임상적 의의와 뇌영상검사와의 상관성을 알아보기 위해 본 연구를 시행하였다.방 법 : 한양대학교병원 소아과에 입원하여 시행한 뇌파검사상 PLEDs를 보인 환아들중 후향적 연구가 가능하였던 2일에서 14세까지의 환아 20명(남아 10명, 여아 10명)을 대상으로 내원시 주소, 의식상태, 경련의 과거력, 초기진단, 뇌파검사상 PLEDs의 위치, 뇌영상검사 소견과의 상관성, 최종 진단 및 후유증에 대해 후향적 연구를 시행하였다. Purpose : Periodic lateralized epileptiform discharges(PLEDs), initially described by Chatrian et al in 1964, are an EEG phenomenon characterized by lateralized or focal spike-and-wave complexes with moderate to high voltage which occur in a periodic or semiperiodic pattern. This study was performed to assess the clinical significance of PLEDs and its relation to an imaging study of the brain. Methods : Twenty children(10 males and 10 females), from 2 days to 14 years of age, who had been hospitalized at Hanyang University Hospital were studied retrospectively. Their medical records, EEG results and brain imaging study were reviewed. Results : Of the 20 patients studied, 15 patients showed unilateral PLEDs and 5 had bilateral PLEDs in EEG. Brain imaging studies were done for 18 of the patients, revealing abnormalities in 15 patients in this order of frequency : intracranial hemorrhage, diffuse cerebral atrophy, leukomalacia, cerebral infarctions, cerebral edema and hydrocephalus. PLED sites were not significantly correlated with the results of the imaging study. Finally, 3 patients died and 17 patients survived, and among the surviving 17 patients, 5 had recurrent seizures, 1 had recurrent seizures with mental regression, 3 had neurologic sequelae without seizures and 8 had no neurologic sequelae. Conclusion : We conclude that children who show PLEDs in EEG are more commonly associated with acute cerebral lesions and there is a high incidence of subsequent seizures and/or other neurological sequelae in surviving children with PLEDs.
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Screening Test(I) of Several Antipsychotic Agents on NO Formation
이종화,Lee, Jong-Hwa,EI-fakahany, Esam E. The Korean Society of Pharmacology 1994 대한약리학잡지 Vol.30 No.3
정신병치료제들을 장기투여하여 치료를 시도하였을 때에 생기는 여러 부작용은 그 정도 또한 매우 심각하기 때문에 그들의 치료효과와 함께 야기되는 부작용들을 따로 생각할 수가 없게 되었다. 특히 정신병치료는 그 자체에 대한 병인적 원인을 정확히 알 수 없기에 증상에 따른 대중요법이 일괄적으로 사용되므로, 이러한 현재의 치료방법으로는 부작용들이 더 치명적이 될 수 있기 때문에 일차적으로 이들의 공통적약리작용기전들을 연구하는 것은 매우 필요하다. 최근 NO(Nitric oxide)에 대한 많은 연구들에 의하면, 이들이 중추신경계에서 중요한 second messenger 또는 mediator로 신경활동에 영향을 나타내는 것으로 보고되고 있다. 그러므로 저자들은 먼저 이들 약물들과 NO와의 관계를 연구하고자, 중요한 몇종의 정신병치료제들을 택하여 NO생성에 어떤 영향을 미치는 가를 검색하여 다음과 같은 일차 결과를 얻었다 1. 정신병치료제 수종(chlorpromazine, trifluoperazine promazine, pimozide, clozapine, chlorprothixene, haloperidol)을 택하여 쥐의 소내에서 $[^3H]L-arginine$으로부터 $[^3H]L-citrulline$의 생성양을 측정하여 calmodulin antagonist(calmidazolium)와 비교하였다. 2. 이들을 N1E-115 cell에 투여하여 $[^3H]cyclic$ GMP양을 측정하고 그 결과를 calmida-zolium 과 비교하였다. 3. 이들 약물들은 citrulline과 cyclic GMP 모두의 생성양을 의의있게 억제하였으며 그 기전은 calmidazolium과 매우 유사하였다. 위의 일차적 검색결과에 의하면, 정신병치료약물들의 약리작용 기전중에 일부는 중추신경계내의 NO생성 및 cyclic GMP생성에 영향을 나타내는 것으로 사료되며, 이에는 calcium ion이 상당히 중요한 역할을 하는데, 특히 소뇌에서의 NO생성의 감소는 이들 약물들의 치명적 부작용인 tardive dyskinesia와 매우 깊은 관련을 추측할 수 있다. 그러나, 더 많은 약물들의 검색으로 일관적인 기본 결과가 필요 되고 또 각개 약물의 특정적 기전이 연구되기 위하여 현재 실험중이다. A number of neurological syndromes(e.g. tardive dyskinesia) are developed as a consequence of chronic treatment with neuroleptics or antipsychotic agents. Despite the long and succesful use of phenothiazine derivatives and related agents in the treatment of certain states of mental disease, the mechanisms of these drugs are still poorly understood. One current hypothesis from extensive reviews is that these compounds might significantly interfere with the cyclic nucleotide system in brain (Levin and Weiss, 1977; Nowicki et al., 1991; Haley et al., 1992). Nitric oxide (NO), one of an interesting messenger molecule and aberrant transmitter, is believed to play a important role in biological functions of cyclic nucleotides in nervous system. It has been reported that calcium-dependent NO synthesis in endothelial cytosol is mediated by calmodulin which is supposed to be tightly related to pharmacological actions of antipsychotic agents. In the present study, the effect of several antipsychotic agents on the activity of NO synthesis and formation of cyclic GMP were investigated. These agents inhibited both the formation of $[^3H]L-citrulline$ and that of $[^3H]cyclic$ GMP by concentration-dependent manner, and their inhibiting patterns are so similar to that of calmodulin antagonist.
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