만정 뇌경막하혈종에서 술전 CT음영 및 천두폐쇄배액술후 배액량과 재발과의 상관관계에 대한 연구

임동준,박윤관,정용구,김봉룡,정흥섭,이기찬,이훈갑,서중근 대한신경외과학회 1998 Journal of Korean neurosurgical society Vol.27 No.10

후방순환계 뇌동맥류의 임상분석

임동준,이훈갑,정흥섭,김봉룡,권택현,이기찬,서중근 대한신경외과학회 1998 Journal of Korean neurosurgical society Vol.27 No.11

급성기 뇌지주막하출혈에서 Three-Dimensional Computed Tomographic Angiography (3-D CTA)의 유용성

임동준,이훈갑,김봉룡,정흥섭,정용구,이기찬,서중근 대한신경외과학회 1998 Journal of Korean neurosurgical society Vol.27 No.12

흰쥐 해마박편에서 콜린성 수용체와 glutamate 유리와의 상호관계에 관한 연구

신동인,김형룡,고성희,김관식,정동균 대한구강생물학회 1990 International Journal of Oral Biology Vol.14 No.2

Present study was performed to clarify the effect of cholinergic agents on the release of glutamic acid employing hippocampal slices. Hippocampal slices(300∼400㎛ thick) were prepared by the method of Kim et al.(1988) and pre-equilibrated in Krebs-bicarbonate medium(KBM, pH 7.4) for 1hr at 37℃. Pre-equilibrated slices were incubated in fresh KBM and then potssium(50mM)-containing KBM for 5 min period. Basal and potassium-induced release of GABA and glutamic acid were determined from recovered medium by HPLC. After 30 min resting period, slices were reincubated in cholinergic agents-containing KBM and cholinergic agent plus potassium-containing medium consecutively for 5 min period each to investigate the effect of cholinergic agent on basal or potassium-induced glutamic acid release from hippocampal slices. The observed results were as follows: 1. The release of glutamic acid induced by the first and second 5 min-exposure of 50mM potassium was 139.7±14.05 nmol and 114.5±10.01 nmol, respectively. When compared with released amounts of glutamic acid during the corresponding spontaneous periods, these were 5.3 and 5.6-fold increase respectively. 2. Acetylcholine(10-1000μM) inhibited potassium-induced glutamic acid release in dose-dependent manner. 3. The inhibition of glutamic acid release caused by acetylcholine(1mM) was antagonized by atropine(50μM) but not by mecamylamine(50μM).

Norepinephrine이 흰쥐 해마박편에서 아미노산 신경전달물질 유리에 미치는 영향에 관한 연구

김성룡,김관식,정동균 대한구강생물학회 1990 International Journal of Oral Biology Vol.14 No.1

Present study was performed to clarify the effect of norepinephrine on the release of amino acid neurotransmitters employing hippocampal slices. Hippocampal slices (300-400㎛ thick) were prepared by the method of Spencer et al.(1976) and pre-equilibrated in Krebs-bicarbonate medium (KBM, pH 7.4) for 1 hr at 37℃. Pre-equilibrated slices were incubated in fresh KBM and then veratrine (25μM)-containing KBM for 10 min period. Basal and veratrine-induced release of GABA and glutamic acid were determined from recovered medium by HPLC. After 30 min resting period, slices were reincubated in norepinephrine-containing KBM and test agent plus veratrine-containing medium consecutively for 10 min period each to investigate the effect of norepinephrine on basal or veratrine-induced amino acid release from hippocampal slices. The observed results were as follows: 1. The release of GABA induced by the first and second 10min-exposure of 25μM veratrine was 246.9±16.82 nmol and 209.9±20.84 nmol, respectively. When compared with released amounts of GABA during the corresponding spontaneous periods, these were 7.3 and 7.3-fold increase respectively. 2. The release of glutamic acid induced by the first and second 10min-exposure of 25μM veratrine was 426.3±63.16 nmol and 377±61.83 nmol, respectively. When compared with released amounts of glutamic acid during the corresponding spontaneous periods, these were 9.9 and 10.2-fold increase respectively. 3. Norepinephrine (1-100μM) increased veratrine-stimulated and spontaneous release of GABA in dose-dependent manner. 4. Norepinephrine (1-100μM) inhibited veratrine-stimulated glutamic acid release in dose-dependent fashion.

퍼지 PID제어기를 이용한 직류 전동기의 속도제어에 관한 연구

김동희,박순규,김자룡 진주여자전문대학 1994 論文集 Vol.17 No.-

본 논문은 직류서보 전동기 시스템의 퍼지논리를 이용한 PID제어의 한 기법이다. 이러한 제어기법은 재래식 조정기법(ITAE table)을 이용하여 정상적인 제어기의 변수를 조정한 다음 퍼지제어 행렬을 사용하여 시스템이 동작하는 동안 작은 이득값의 변화를 결정함으로서 전동기의 속도제어 시스템의 정상상태오차와 과도응답의 성능을 향상시킬 수 있으리라 기대된다. 이러한 시스템은 마이크로프로세서를 이용함으로서 쉽게 실현할 수 있다. This paper present an approach to use fuzzy logic PID control of DC servo control system. This approach assumes that available nominal controller parameter settings through some classical tuning technique (ITAE table). By using an appropriate fuzzy matrix(which is 3- separate Look-up Table), we determine small changes on these gain values during the system operation, and these lead to improved performance of the transient and steady behavior of the motor speed control system, this achieved at the expense of some small extra computational effort, which can be very easily undertaken by a microprocessor.

실관막을 이용한 중금속 추출에서 물질전달에 미치는 분배비의 영향

李龍珍,金英一,陳道源,黃德基,朴東源 동아대학교 공과대학부설 생산기술연구소 1997 生産技術硏究所硏究論文集 Vol.2 No.1

The liquid-liquid extractions by use of microporous hollow fiber membrane modules are fast compared with conventional extraction equipment. Because they have a large surface area per volume. Solute diffuses out of the feed solution, through the fibers' porous wall, and into the extractant. The extractant and feed can be contacted at high speed, there are no problems with flooding, loading and channeling. Moreover, these modules should be characterized by low investment and operating costs because of the reduced hardware and the favorable hydrodynamics which minimizes concentration polarization and membrane fouling. In this paper, it was investigated the extraction selectivities for liquid-liquid extraction of heavy metal(Cd(Ⅱ)Co(II)) from dilute aqueous solution into the eatractants(EHPNA and TBP) by using the hydrophobic hollow fiber module. We also examined the effect of distribution ratio on the overall mass transfer coefficients.

급성 유기인제 중독환자의 혈청 Cholinesterase 활성도와 임상적인 의의에 관하여

전동석,김재룡,박승국,김윤년,이경민,윤덕구 啓明大學校 醫科大學 1988 계명의대학술지 Vol.7 No.2

To study the pseudocholinesterase acticity and its clinical significance in patients with acute organophosphate poisoning, Authors checked the serum cholinesterase activity in 49 normal subjects and 31 acute organophosphate poisoned patients. The results were followings. 1. The mean pseudocholinesterase activity f normal subjects was 1271 IU/L in male and 1131 IU/L in female. The total mean cholinesterase activity was 1209/ IU/L. 2. The pseudocholinesterase activity of patients were significantly reduced compare to normal. 22 patients(73%) were below 10% of normal, 6 patients(20%) were between 10-20% of normal and only 2 patients (7%) were between 20-50% of normal. 3. As a whole there was more depressed cholinesterase activity in patients with comatous and drowsy mentality, but there was no statistically significant difference between three groups. 4. The pseudocholinesterase activity in patients with respiratory failure was more depressed than without respiratory failure, but there was no statistically significant difference between three groups. 4. The pseudocholinesterase activity in patients with respiratory failure was more depressed than without respiratory failure, but there was no statistically significant difference presented. 5. The mean arterial blood gas checked on arrival was pH 7.386, PaO?? 66mmHg, PaCO?? 38mmHg 02 Saturation 91%. There was noted no statistically significant correlation between pseudocholinesterase activity and these parameters. 6. The pseudocholinesterase activity on the 1st day of admission was 5.7% of normal and progressively increased during admission. On the 14th day of admission, the pseudocholinesterase activity was 35.5% of normal and it takes 20 days to reach 50% of normal. Authors concluded that serum cholinesterase activity of acute organonphosporus poisoned patients were markedly depressed and progressively increased during admission. As a whole the pseudocholine-sterase activity seemed to be related to the clinical findings but no statistically significant difference was found.

실관형 막모듈에 의한 Hg(Ⅱ)의 분리에 관한 연구

이용진,김만수,황덕기,박동원 동아대학교 환경문제연구소 1997 硏究報告 Vol.20 No.1

By use of hollow fiber membrane module, this study examines the value of H(distribution ratio) and Kw(overall mass transfer coefficient) on the Hg(Ⅱ), and used di-2-ethylhexylphospric acid(DZEHPA), tributyl phosphate(TBP), tri-n-octylamine(TOA) as extractant, Also, shown the change of changing the acid. From these experiments and discussions, we have the results as follows. 1. In case of Hg(Ⅱ), the order of well seperated is TOA, DZEHPA, TBP. 2. Concentration decrease ratio have the straight lines for the changing of the time in each systems. So, It was know that the result coincide with theory. 3. The effect of Kw vs. H were shown that in case of H is lower than 10, H is high effect. But H is higher than 10, H is low effect.

SOL-GEL법을 이용한 강유전체 BaTiO₃박막 및 Ceramics 제조

조채룡,이수재,장민수,김호종,정세영,노동택,김성철 동의대학교 기초과학연구소 1993 基礎科學硏究論文集 Vol.3 No.1

Concentrated solution was prepared for a sol-gel process of BaTiO₃. Barium hydroxide and Ti-isopropoxide were used as the raw materials with methanol and isopropanol as solvents. Dense ferroelectric polycrystalline BaTiO₃thin films with the perovskite structure were fabricated by spin coating of the prepared concentrated solution on a few substrates. From XRD investigation, it was confirmed that tetragonal phase of polycrystalline BaTiO₃powders are formed after heat treatment above 550℃ in air and grain-oriented BaTiO₃thin films are obtained by coating of 0.06M concentrated solution on the substrates. It was observed that surfaces of thin films deposited on the substrates by our methods were formed crack-free and uniformly. The thickness of thin film which depends the concentration of the solution was 400∼900Å for 1 time coating, which was confirmed by SEM analysis. Ceramics and thin films show dielectric constant of 4600 (at 1㎑) and capacitance 300∼800㎊ (at 1㎑) at room temperature, respectively.