터빈 로터의 응력해석 및 수명평가

정순억(Soon-Uk Chung),정순호(Soon-Ho Chung),장윤석(Yun-Souk Chang),이현우(Hyun-Woo Lee) 한국해양공학회 1988 韓國海洋工學會誌 Vol.2 No.1

The increasing size of steam turbines during recent years has resulted in corresponding increase in diameters of rotors. These larger rotor diameters lead to higher thermal stress in the rotor during start up. So the development of system for rotor life evaluation methodology becomes quite important. This system performs a computer program analysis for the remaining life evaluation of Y-Fossil turbine rotor as a sample.<br/> Stress and thermal analyses were carried out by FEM (finite element method). In the case of the most severe starting condition(115% over speed), the maximum allowable non-metallic inclusion size was calculated through linear elastic fracture mechanics. And, regard of operating conditions(cold, warm, hot start), life consumption ratios were obtained by low cycle fatigue and creep theory.<br/> FEM program ROTEMP(analysis of rotor temperature) was developed to calculate temperature distribution of the rotor by heat transfer from hot steam. And, stress and life evaluation analyses were calculated by the programs such as ROSTRS (analysis of rotor stress) and ROLIFE (analysis of rotor life), respectively. FEM codes used axi-symmetric, quadrilateral (or triangle) element.

터빈 로터강의 피로크랙전파속도의 확률특성 연구(Ⅰ)

오세욱(Sae-Wook Oh),이치우(Chi-Woo Lee),장윤석(Yun-Souk Chang),정순호(Soon-Ho Chung) 한국해양공학회 1987 韓國海洋工學會誌 Vol.1 No.2

In order to estimate the running life of turbine rotors, fatigue crack propagation law, da/dN=C(ΔK)<SUP>m</SUP>, proposed by Paris et al. has been widely applied.<br/> In this study, fatigue crack propagation rates for 16 samples of 1% Cr-Mo-V rotor steel were measured and statistical characteristics of m and C values in above equation were reviewed.<br/> The results are summarized as follows.<br/> 1. C and m follow a log-normal distribution and normal distribution, respectively. And the relation of C and m shows a strong negative correlation.<br/> 2. Fatigue crack propagation equation can be expressed as da/dN=4.11×10<SUP>-4</SUP>(ΔK/153.8)<SUP>m</SUP>, introducing the relationship C=CoKo<SUP>-m</SUP>.<br/> In this case, contribution of Co distribution to the distribution of log C shows very small compared to degrees of contribution by m.

Prolog언어를 이용한 논리회로의 검증에 관한 연구

정순호 釜山工業大學 1987 論文集 Vol.29 No.-

This paper presents Prolog verifier the functional correctness of logic circuit. From primitive logic circuits to combinational circuits are described as atomic formula and are saved in knowledge set. The verfier builds the behavior expression of the logic circuit based on input descriptions and circuit descriptions and then it checkswhether or not the behavior expressions satisfy the output requirements. The above specifications and requirements are described in Prolog.

소아의 뇌종양 제거술 중 저칼륨혈증에 의한 심정지 1예

권대성,정순호,최영균,김영재,박진우,신치만,박주열 인제대학교 1997 仁濟醫學 Vol.18 No.1

심폐 소생술 중 칼슘의 투여는 재관류 손상(reperfusion injury)을 조장하며 특히 성인의 경우에 전신마취하에서는 심근의 흥분성을 증가시켜 부정맥을 유발할 가능성이 있다고 하여 사용을 기피하는 경향이 있다. 저자들은 소아에서 전신 마취하에 뇌종양 제거술중 발생한 심정지의 심폐 소생술에서 칼슘의 투여 후 활력징후가 회복된 1예를 경험하고 문헌 고찰과 함께 보고하는 바이다. There are controversies in calcium adminstration during cardiopulmonary resuscitation. Calcium can induce reperfusion injury and it can increase cardiac irritability which results in arrhythmias. But in the case of pediatric cardiac arrest. calcium does not increase cardiac irritability and calcium adminstration is relatively safe. A 4-year old male child underwent removal of brain tumor under general anesthesia. During operation, cardiac arrest was developed and did not respond to cardiac massage, cardioversion, epinephrine, etc. Arterial blood gas analysis showed severe hypocalcemia and hyperkalemia during cardiac arrest. After infusion of CaCl2, circulation was restored and vital signs returned to normal. We concluded that calcium should be administered to increase cardiac responsiveness in a case of hypocalcemia combined with hyperkalemia during pediatric cardiopulmonary resuscitation.

척추마취하에 자발 호흡하는 환자에서 Nasal Cannula를 통한 호기말 이산화탄소 분압의 감시

김영재,박진우,이동근,박주열,신치만,최영균,정순호 대한마취과학회 1997 Korean Journal of Anesthesiology Vol.33 No.2

Background : Monitoring of PETCO₂ in the patients during regional anesthesia may be no less important than under general anesthesia, but will aid in early detection of potentially catastrophic events. However, the utility and accuracy of capnography in non-intubated patients has received little attention. We examined correlation between PETCO₂ measured via nasal cannula and PaCO₂ values in the sedated spontaneously breathing patients during spinal anesthesia. Methods : Thirty adult patients who underwent elective surgery were administered optimal doses of tetracaine and epinephrine mixture in their site of operation, length, weight and age. Thereafter, we sampled expired gas by 175ml/min and administered oxygen by 3L/min using oxygen delivery CO₂ sampling nasal cannula. End tidal carbon dioxide tension, heart rate, blood pressure and respiratory rate were measured before and 20 min after 0.02 mg/kg midazolam i.v.. And arterial blood gases were once measured 20 min after 0.02 mg/kg midazolam i.v.. Results : The patients, sedation state was asleep or calm in awake. End tidal carbon dioxide tension was significantly increased after midazolam injection(p$lt;0.01), but another values were not different after midazolam injection. Linear regression analysis of arterial carbon dioxide tension and end tidal carbon dioxide tension after midazolam injection yielded y = 0.77x + 4.82 and r2 = 0.76(p$lt;0.01). Conclusions : End tidal carbon dioxide tension using oxygen delivery CO₂ sampling nasal cannula in the sedated spontaneously breathing patients with midazolam during spinal anesthesia were significantly related with arterial carbon dioxide tension. Therefore, we conclude that monitoring of PETCO₂ via nasal cannula is a reliable means during spinal anesthesia. (Korean J Anesthesiol 1997; 33: 243∼247)

Diazepam 투여시 진정정도에 따른 Long Latency Auditory Evoked Potentials 의 P300의 변화

김영재,박진우,김정환,박주열,신치만,최영균,정순호,권대성,임재중 대한마취과학회 1997 Korean Journal of Anesthesiology Vol.33 No.2

Background : P300 component of the long latency auditory evoked potentials(LLAEPs) provides information on conscious and cortical funtion. The P300 wave occures only for stimuli that somehow capture the patients attention. Therefore LLAEPs implys a degree of cognitive processing. We studied sedation scale and P300 wave to determine if LLAEPs could be utilized as electrophysiologic predictors of sedation. Methods : The P300 component of LLAEPs from vertex was recorded from 10 ASA physical status I and II patients undergoing elective surgery while they listened via headphones to a series of clicks which were interrupted unpredictably by a tone burst(2 KHz) before and after diazepam 0.04 mg/kg and 0.08 mg/kg IV. The patients were asked to concentrate on the clicks and to press a button whenever they detected a 2 KHz tone. And sedation scale also was measured. Results : Amplitude of P300 was decreased and latency of P300 was increased in a dose-dependent manner with IV diazepam. Amplitude was greatest and latency was shortest in awake. And sedation scale also was increased according to increased IV diazepam adminstration. Conclusions : Both amplitude and latency may be highly related to the sedation scale with progressively increasing dose of diazepam. Therefore we conclude that P300 component of LLAEPs can be utilized as an electrophysiologic predictor of awareness and sedation. (Korean J Anesthesiol 1997; 33: 248∼253)