람사협약과 우리나라의 습지보전 정책방향

김원민,Kim, Won-Min 환경보전협회 1996 환경정보 Vol.18 No.11

모터구동밸브의 압력잠김 분석방법

송은실(Song Eun Sil),김원민(Kim Won Min),이광남(Lee Kwang Nam) 대한기계학회 2002 대한기계학회 춘추학술대회 Vol.2002 No.5

Pressure locking occurs when the fluid in the valve bonnet is at a higher pressure than the adjacent piping at the time<br/> of valve opening by pressure trapping and bonnet heatup. Pressure locking is a phenomena which can cause the<br/> unseating thrust for a gate valve to increase from its typically static unseating thrust. This can result in the valve<br/> actuator having insufficient capability to open the valve. In addition, this can result in valve damage in cases where the<br/> actuator capability exceeds the valve structural limits. This paper discusses the primary mechanisms which cause<br/> pressure locking. These include sudden depressurization of piping adjacent to the valve and depressurization of fluid<br/> trapped in the valve bonnet due to heat transfer. This paper provides a methodology to calculate the unseating thrust for<br/> a valve which is pressure locking and applies to motor operated isolation valves of Residual Heat Removal<br/> System(RHRS).

발전소 주급수 계통 감발 과정에서의 스윙체크밸브 닫힘 시점의 실험적 결정

서진성(Suh, Jin-Sung),김원민(Kim, Won-Min) 한국소음진동공학회 2009 한국소음진동공학회 논문집 Vol.19 No.8

The reliable operation of a swing check valve in the main feed water system of a power plant is most essential for successful shout-down process. A failure to close the valve at proper time often leads to the instability of the main feed water system, or even to an emergency stop of the power plant. In reality it is a very difficult task to monitor the behavior of a swing check valve. Furthermore it is impossible to see the motion of the valve. In this work two measurements were carried out simultaneously to determine the precise valve closure time. The dynamic pressure measurements were made at the inlet and outlet regions of the swing check valve. The transient vibration of the valve housing in the direction of water flow was also measured, which enabled the measurement of the transient vibration of the valve housing near valve closure. By comparing the results produced from these measurements the precise valve closure time could be determined. By carrying out order tracking technique using the dynamic pressure signals and pump rpm signal, the complicated dynamic problems inside the main feed water system can be more easily dealt with. This measurement scheme might be implemented in a power plant on a real-time basis without much difficulty. If this could be implemented, valuable information essential for shut-down operations can readily be passed on to the main control room. The feasibility of this implementation was demonstrated by this experimental work.

저알부민혈증에서 관찰한 혈청 전해질, 동맥혈가스 분석과 Anion Gap의 변화

신양수 ( Sin Yang Su ),임현성 ( Im Hyeon Seong ),김원민 ( Kim Won Min ),김완중 ( Kim Wan Jung ),장경식 ( Jang Gyeong Sig ),문철웅 ( Mun Cheol Ung ),김호중 ( Kim Ho Jung ) 대한내과학회 1992 대한내과학회지 Vol.42 No.5

연구배경 : 저알부민혈증의 환자는 전체 체용량은 증가되어 있으나 유효 순환 용량은 감소되어 있다. 이에 동반될 수 있는 혈청 전해질, 특히, 나트륨, 칼륨 농도의 변화, 동맥혈 가스 분석, anion gap의 감소 정도를 관찰함과 동시에, 이러한 변화를 기저 질환에 따른 혈청 알부민 농도의 감소 정도와 비교 분석하여 상호 연관 관계를 관찰하였다. 방법 : 전향적 관찰로써 저혈압이나, 유산증, 케톤 산증등 뚜렷한 유기 산증이 보이지 않는 저알부민혈증을 가진(혈청 알부민 3.1gm/dL 이하) 31명을 기저질환에 따라 신증후군의 12명(group 1), 간경변증 환자인 9(group 2), 다른 만성 질환을 가진 10명(group 3)으로 나누고, 이 군들과 17명의 건강인(group 4)을 대상으로 혈청 알부민, 전해질 농도, 동맥혈 가스 분석을 동시 측정하고, Na^(+)-(CI^(-)+HCO^(-)₃)로 anion gap을 계산하였다. 결과 : 1) 저알부민혈증의 각군에서 저나트륨혈증, 저칼륨혈증, anion gap의 감소, 동맥혈 pH의 상승(alkalemia)이 관찰되었고, 신증후군(group 1)의 혈청 나트륨, 칼륨, 동맥혈 pH를 제외하고는 각각의 평균치는 대조군에 비해서 모두 통계학적으로 유의하였다(p<0.01)>. 2) 저알부민혈증 환자(n=31)와 건강한 대조군 (n=17)과 비교시 평균 알부민 농도의 감소에 따라 anion gap의 평균치도 의의있게 낮았으나(p<0.001), 상호비교시, 혈청 알부민 농도가 2.6 gm/dL의 감소가 있는 반면, 4mEq/L의 anion gap의 감소 정도는, 정상혈 pH에서 혈청 알부민 1 gm당 2.54mEq/L 이상의 음이온가를 가진다는 기왕의 보고된 사실로 미루어 보아 예상치보다 덜 감소되어 있었다. 3) 총 48명에서 각각의 혈청 알부민 농도와 혈청 나트륨 농도 사이 (r=0.57,p<0.001), 그리고 각각의 혈청 알부민 농도와 anion gap의 사이 (r=0.62, p<0.001)에는 의의있는 상관관계가 있었다. 결론 : 저알부민혈증의 환자에서 저나트륨혈증, 저칼륨혈증, alkalemia, 그리고, 감소된 anion gap을 관찰하였으며, 각각의 혈청 알부민 농도와 혈청 나트륨 농도, anion gap 사이에는 의의있는 상관관계가 있었다. 저알부민혈증의 환자에서 anion gap의 감소 정도는 단순히 혈청 알부민 농도의 감소 뿐 아니라, 저알부민혈증과 동반된 다른 요인들, 즉, alkalemia, 저나트륨혈증, 본연구에서는 측정하지 않은 유산이나 아직 알려지지 않은 음이온을 갖는 물질의 상승에 따른 총화의 결과로 사료된다. Background : The clinical conditions of hypoal-buminemia known as decreased effective arterial blood volume despite increased total blood volume would be well associated with changes of serum electrolytes and acid-base imbalances at initial presentation and/or on the course of tratments for this hypoalbuminemia. The purpose of this study is to determine the influence of hypoabluminemia related to the diverse underlying causes on concentrations of serum sodium and potassium, arterial blood gas findings and the degree of reduced anion gap as well as cause of it. Methods : Thirty one patients admitted to medical wards with hypoalbuminemia (serum albumin13.1 gm/dL) subdivided to three groups (group 1, nephrotic syndrome; group 2, liver cirrhosis; group 3, other chronic diseases) by underlying diseases, but without hypotension or overt organic acidosis, and seventeen healthy control subjects designated as group 4 (serum albumin>4.0 gm/dL) were included in this prospective study. Simultaneous measurements of serum electrolytes, calculation of anion gap as Na^(+)-(Cl^(-)+HCO^(-)₃), and arterial blood gas analysis were performed. Results : Hyponatremia, hypokalemia and decreased anion gap with more alkalemic pH were observed in mean values of each hypoalbuminemic subgroup when compared to control group with statistical significance (p<0.01) except mean value of serum sodium, serum potassium and alkalemia in a subgroup with nephrotic syndrome. Mean albumin level and mean anion gap of total hypoalbuminemic patients (n=31) were significantly lower compared to those of control healthy subjects (n=17)(p<0.001). However, the difference of reduced anion gap (mean value, 4 mEq/L) was smaller than expected to degree of serum albumin reduction (mean value of reduction, 2.6 gm/dL) on view of more than 2.5 mEq/L of negative charges per 1 gm of serum albumin in normal blood pH. In all 48 subjects, a statistically significant correlation was found between serum sodium and individual albumin (r=0.57, p<0.001), and between the anion gap and individual serum albumin (r=0.62, p<0.001) with no correlation between the anion gap and serum sodium as well as the anion gap and arterial pH. Conclusions: Hyponatremia, hypokalemia, alkalemia and decreased anion gap were commonly noted in patients with hypoalbuminemia in addition to statistical significant positive correlation between the anion gap and individual serum albumin, and between serum sodium and individual serum albumin. The decrement of anion gap associated with hypoalbuminemia was out of proportion to the degree of hypoalbuminemia, which would be explained by summation of other factors associated with hypoalbuminemia, such a s alkalemia, hyponatremia, unidentified anions and increased lactate in alkalemia though not measured in this study.

만성 활동성 간염에 병발한 재발성 Guillain-Barre´ 증후군 1예

임현성,신양수,김원민,최성도,정태홍,김만우,조경원,정원영 대한내과학회 1993 대한내과학회지 Vol.44 No.2

저자등은 간 생검으로 밝혀진 41세된 만성 활동성 간염환자에서 발생한 사지마비 및 호흡마비등의 증세등이 뇌척수액 소견과 전기생리학적 소견이 GBS와 부합되고, 간염의 악화-호전과 경과를 같이하는 양상을 보였기에 보고하는 바이다. Guillain-Barre syndrome complicating chronic active hepatitis is rare. In its antecedent and associated illness, various viral infections are commonly involved (esp. viral hepatitis). A classic features that allow diagnosis of GBS is ascending symmetrical weakness, areflexia, minimal sensory loss, and albuminocytological dissociation in CSF. A number of neurological complications of viral hepatitis have been reported, including hepatic coma, hemorrhages into the CNS, both subdural and intraparenchymal. encephalitis, meningitis, myelitis, isolated pyramidal tract and extrapyramidal tract dysfunction, Meniere's disease, dermatomyositis, seizures, mononeuritis, plexitis, and psychiatric disturbances. But there were no reports about GBS complicating chronic active viral hepatitis in Korea until now. We report a case of GBS complicating chronic active hepatitis in a 41-year-old male.