인공판막 재대치험예에서의 판막실패의 양상

박영배,김유호,서정돈,최윤식,이영우,오병희,도문홍,최동주,전은석 대한내과학회 1987 대한내과학회지 Vol.32 No.3

In order to observe the aspects of prosthetic cardiac valve failure, we analyzed 26 cases of Redo operation among 1081 cases of valve replacemant performed from Jan. 1961. to July 1986. The results are as follows; 1) Crude Redo operation rate was 2.4%. 2) The most common cause or prosthetic cardiac valve failure was the primary tissue failure (73%) 8r the PVE was the 2nd (15.4%). 3) Mean valve implantation time was 47.7 months. Implantation time in the child group was shorter than in adult by 6.8 months, In the primary tissue failure group (19 cases) implantation time in the child was 42.8 months 8z in adult, 66.8 months. (P$lt;0.05) In conclusion, the durability of tissue valves was significantly decreased in the child age group because of increased propensity for calcification, so the preference of tissue valves especially in this age group should be reconsidered.

급성췌장염에 의한 췌장가성남종에서 내시경적 배액술후 발생한 췌장가성남종과 십이지장 및 대장에 발생한 내부 췌장루 1예

김연수,이문성,김진오,조영덕,이영홍,봉형근,조주영,이준성,심찬섭,황성규,전기원,변재호,장재영 대한소화기학회 1996 대한소화기학회지 Vol.28 No.1

양산단층 중앙부의 활단층 지형과 Trench 조사

조화룡,강전독정,전명순,김성작,도변만구,좌등비여지,전정수,지헌철,미지화부 한국지형학회 1994 한국지형학회지 Vol.1 No.2

梁山斷層系의 중앙부에 대하여 항공사진 판독과 현지 지형, 지질 조사를 통하여 다음과 같은 사실이 밝혀졌다. 1. 梁山斷層系는 第脚紀(後期)에도 활동을 반복하고 있는 活斷層이다. 따라서 이 단충은 그 좌우에 분포하는 高位, 中位, 低位의 각 河岸段丘面 모두를 상, 하방향으로 누적적으로 변화시키고 있다. 2. 梁山斷層系의 중앙부에서 段丘面의 變位로 미루어 볼 때 동측이 상대적으로 隆起하고 있다. 이것은 이 지역의 中地形的 山地高度의 분포와는 逆이다. 3. 斷層線온 현저하게 直線的으로 연장되어 있고, 斷層面은 거의 수직이다. 이 斷層系에 수반되는 破碑帶도 폭 수십 m 이상으로 넓고, 현저한 斷層粘土帶와 變形帶를 동반한다. 4. 偏平礫의 변형 형태에 의하면 走向移動이 탁월한 단층운동이 추정된다. 斷層粘土帶의 破碎物質의 관찰에 의하여 右橫變位走向移動(right strike slip)이 인정된다. 5. 이들의 특징으로부터 梁山斷層系는 走商移動(右橫變位)이 탁월한 活斷層으로 판명되었다. 段丘面 및 堆積物의 추정 계산치로부터 梁山斷層系의 평균 상, 하 變位 速度는 0.02-0.03㎜/y. 정도이고, 右橫變位의 평균 속도는 적어도 C급 상위(0.05∼0.1㎜/y.) 정도이든지 이것을 약간 상회하는 정도일 것으로 추정된다. 6. 低位 및 最低位의 段丘面에서는 上位變位를 밝히기 어려웠다. 이들의 段丘面 위에는 논으로 이용되고 있기 때문에 오랜 기간 동안 인공적으로 改變을 받아왔으며 이들 단구면 위에서 1 ∼2m 정도의 상·하 변위가 있었다고 해도 인공적 개변이 이를 지워버렸을 것이다. 따라서 이들의 최근에 형성된 단구면에서는 변위의 유무를 언급할 수 없었다. Many distinct lineaments have been recognized by Landsat images In Korea Peninsula. The Yangsan fault system situated in the southeastern part of Korea is especially linear, continuously traceable for a long distance(about 200㎞), and particularly remarkable among these linearnent. The topographic expression of the Yangsan fault system is derived from the straightly stretching fault valley with wide shattered zones in the direction of NNE-SSW. This fault system extends for about 200㎞ from the mouth of the Nagdong River west of Busan in the south to Yeondong in the north, and geologically separates Korean Peninsula from the East Sea. The amount of horizontal displacement may reach 30㎞. It is recognized as one of the most important faults in Korea Peninsula. From the interpretations of aerial photographs, and field surveys along the central part of the Yangsan fault system, the main results are summarized as follows; 1. The Yangsan fault system has repeatedly moved in the late Quaternary. The lower to higher river terrace surface on this system show cumulative vertical offsets. 2. The vertical component is upthrown on the east side from considering the terrace offset and the distribution of the mountainous lands. This vertical movement is reverse to the topographical situation on the meso-scale. 3. The fault trace is extremely straight. The fault plane is almost vertical. The shattered zone exceeds tens of meters in width with a remarkable fault gouge. 4. The longer axis of flat clasts within the gravel excavated in the exploratory trench showed the rearrangement along the fault. The predominantly right-lateral movements were recognized as the elongation of clayey parts and breccias in the fault gouge. 5. From these characteristics, the Yangsan fault was clarified to be active with predominantly right-lateral movement. Estimated ages of terraces and its deposits give average rates of vertical and right slip on the Yangsan fault system at about 0.02~0.03&/y., respectively. 6. The fault topography is not found on the lower terraces. As the surface of lower fault scarplets less than a few meters high might have been modified or destroyed by the human actions. Therefore, we cannot mention the existence of the younger movement on the lower terraces.

미세현미조작된 생쥐배의 발생과 단일할구의 성감별 기술에 관한 연구 (1) 2. 미세조작에 의해 분리된 할구의 염색체 분석조건에 관한 연구

박수봉,최광수,전익수,정범식 경북대학교 유전공학연구소 1995 遺傳工學硏究所報 Vol.10 No.1

The study was carried out to investigate the optimum condition of C-handing for sexing mouse embryo by chromosome analysis of single blastomere. The sexing rate was 42.9% with the 114 blastocyst embryos which were used C-handing after being hypotonic-treated in 1% sodium citrate for 30 minutes. The separated blastomeres for 4-cell embryos were used For C-banding after being hypotonic-treated in 1% sodium citrate for 20-30, 10-15 and 1-2 min., and the sexing rate For different treatment times were 5.5%, 0% and 0%, respectively. The separated blastomeres from 4-cell embryos were used for C-banding after being hypotonic-created in 30% fetal calf serum for 20-30. 10-15 and 1-2 min., and the sexing rate for different treatment tunes were 18.5%. 0% and 0%, respectively.

WC-TiN 초고경도 복합재료 박막 합성 및 기계적 특성에 관한 연구

한전건,명현식,윤주선 대한금속재료학회(대한금속학회) 2000 대한금속·재료학회지 Vol.38 No.4

Composite films have been one of approaches for new hard coating development and provided properties which are unachievable in uniform materials. Structurally, composite films tended to have dense and fine granular structure because column propagation was periodically interrupted by the nucleation of another phase. In this study, WC-TiN composite films were deposited on cemented carbide substrates by cathodic arc ion plating process. The chemical compositions and crystal structures were evaluated by energy dispersive spectroscopy(EDS) and X-ray diffractometry(XRD), respectively. Film thickness and fracture morphologies were investigated by using scanning electron microscopy(SEM). The mechanical properties such as film adhension and microhardness were evaluated by scratch test, microknoop hardness test and nano indentation hardness test. The microhardness of the WC-TiN composite film on cemented carbide was measured to be 4000(㎏/㎟) which is 1.5 times higher than that of the WC and TiN single layer. The critical load(Lc) of WC-Ti/WC-TiN multi-layer film was measured to be 48.5N in scratch test.

Arc-Magnetron 복합 코팅 공정에 의한 (TiAl)N 박막 합성에 관한 연구

한전건,윤주선,한준희 대한금속재료학회(대한금속학회) 2000 대한금속·재료학회지 Vol.38 No.3

(TiAl)N films deposited by cathodic arc process employing two separate targets of Al and Ti have lots of macro-particles on the surface. The macro-particles were found out to be generated mainly from Al cathode of low melting temperature. In the previous study, TiN films deposited with external magnetic field showed remarkable reduction of surface droplet. For the (TiAl)N coatings, however, the efficiency of Al droplet removal was not so much as TiN films. A new coating concept combining magnetron sputtering and arc evaporation for improved coating properties was made in this study. (TiAl)N and Al-gradient (TiAl)N coatings were deposited by arc-magnetron hybrid process and content of Al in the films was changed by power density of Al magnetron sputtering source. This hybrid process allowed compositionally gradient (TiAl)N coatings to be deposited with low macro-particles and excellent adhesion. It is noted that Al-gradient (TiAl)N coating showed micro hardness of 3,000 ㎏/㎟ and good adhesion of HF2 grade. The present study introduces the hybrid process parameters involved. The formation behavior of (TiAl)N and Al-gradient (TiAl)N coatings were investigated by SEM, EDX AES and XRD.

레이저 용접을 위한 박판재의 정밀 전단 메카니즘 개발 : 유한요소법을 이용한 정밀 전단 공정해석 Analysis of Precise Shearing Process using FEM

조명래,표창률,전병희 한국산업안전학회 1999 한국안전학회지 Vol.14 No.4

Recently, Tailor Welded Blank (TWB) is widely used in automotive industry since the trans formation characteristic of its material can be changed. However, clearance between welding surfaces becomes the important factor which affect the quality of the laser weld, causing difficulties in preparing the sheet. The objective of this paper is to systematically evaluate the effects of previously presented fracture criterion and shearing condition on precise mechanical shearing simulation result. For this purpose, a parametric study was performed to investigate the effect of finite element size and fracture criterion on simulation result. Also, in order to predict the optimum shearing condition, effect of shearing conditions such as clearance and punch radius on the shear plane shape was evaluated.

미세현미조작된 생쥐배의 발생과 단일할구의 성감별 기술에 관한 연구 (1) 1. 미세조작된 배의 생존성과 분리된 단일할구의 체외 발생태에 관한 연구

박수봉,최광수,전익수 경북대학교 유전공학연구소 1995 遺傳工學硏究所報 Vol.10 No.1

This study investigated survival and development in vitro of micromanipulated embryos and biopsied blastomeres during early development of mouse embryos. The micromanipulated 4-cell and intact 4-cell embryos in Medium 2 developed to blastocyst stage by 83.3% and 90.4%, respectively. Blastomeres either biopsied or separated of 4-cell embryos in vitro developed to trophoblastic vesicle by 80.8% and 83.3%, respectively. After transfer to pseudopregnant recipient mice, the offspring races of biopsied embryos and intact embryos were 36% and 48.6%, respectively. The results suggest that the biopsy of single blastomeres from 4-cell mouse embryos have no detrimental effect on survival of embryos and blastomeres.

Bias Voltage 에 따른 WC 박막의 형성거동 및 밀착력 향상에 관한 연구

김상식,한전건,명현식 대한금속재료학회(대한금속학회) 1999 대한금속·재료학회지 Vol.37 No.11

WC mono- and multilayer films were deposited on STD61 and cemented carbide substrates by Cathodic Arc Ion Plating process in various bias voltages of 0V to 200V. Chemical compositions and deposition rates were investigated using Energy Dispersive Spectroscopy(EDS) and Scanning Electron Microscopy(SEM). Microstructures of WC films were analysed by X-ray Diffractometer(XRD). The adhesion and microhardness were evaluated by Rockwell-C indentation test method, Scratch test and Microknoop hardness test. The films were formed in a mixture of α-W₂C(hexagonal structure) and β-WC(B1 NaCl structure) phase and the preferential orientation of β-WC have been changed from [311] to [220] with increasing bias voltage. The microhardness of the deposited WC films on cemented carbide were evaluated up to Hk3000 and WC multilayer films exhibited good adhesion in Rockwell-C indentation test and Scratch test.

PETRI NET 를 이용한 평행 예측 - 교정 연산에 관한 연구

전흥우,차균현 고려대학교 공학기술연구소 1982 고려대학교 생산기술연구소 연구보고 Vol.17 No.1

Petri Net is a modeling device for representing and studying concurrent and parallel systems. In this paper, the papallol predictor-corrector algorithm using Petri net is discussed. And, an application of this model to the computation of the test equation and the state equation for the tunnel diode oscillator is presented. In this way, algorithms and systems can be analyzed concretely, and programed according to the transition firing sequence.