영광원자력발전소 주변의 식생과 식물현존량 추정

이호준,양효식,전영문,정흥락,강재구,방제용 建國大學校基礎科學硏究所 1996 理學論集 Vol.21 No.-

영광원자력발전소 주변의 식생에 대한 식물사회학적 조사를 실시하였으며, 순 1차 생산량과 식물현존량을 추정하였다. 또한 상관에 의해 현존식생도 및 녹지자연도를 작성하였다(1:50,000). Z-M 방식에 의한 삼림식생은 소나무군락과 곰솔군락으로 구분되었다. 전체적으로 교목층에 소나무와 곰솔, 아교목층에 졸참나무와 곰솔, 관목층에 털진달래와 신갈나무, 초본층에 털대사초와 그늘사초 등의 피복지수가 우세하게 나타났다. 토양의 pH는 4.65∼4.67, 유기물 함량은 7.28∼7.53%의 범위였다. 현존식생도에 의한 분포비율은 경작지(67%), 소나무(21.9%) 및 곰솔군락(9.1%)의 순으로 나타났으며, 녹지자연도는 등급 2가 67%(경작지), 7등급(이차림(A))과 6등급(조림지)이 각각 29.2%와 1.8%로 나타났다. Montreal model에의한 소나무림과 곰솔림의 식물현존량은 657,817.2와 177,367.0ton으로 각각 산정되었다. The forest vegetation and estimation of phytomass and net primary production in the vicinity of Yonggwang Atomic Power Plant were analyzed on the basis of the phytosociological data. Depending on physiognomy, the actual vegetation map and the degree of green naturality(DGN) were also drawn in the scale of 1:50,000. According to Z-M method, the forest vegetation was classified into two communities; Pinus densiflora and Pinus thunbergii communities. It was generally shown that Pinus densiflora and Pirus thunbergii in tree-1 layer, Quercus serrata and Pinus thunbergii in tree-2 layer, Rhododendron mucronulatum var. ciliatum and Quercus serrata in shrub layer, and Carex ciliato-marginata and Carex lanceolata in herb layer had high coverage index. The pHs and contents of organic matter of the forest soils collected in each sites were in the 4.64 to 4.67 and 7.28% to 7.53% in average, respectively. The distribution area of each vegetationindex. The pHs and contents of organic matter of the forest soils collected in each sites were in the 4.64 to 4.67 and 7.28% to 7.53% in average, respectively. The distribution area of each vegetation type in the actual vegetation map was 67% cultivated land, 21.9% in Pinus densiflora community and 9.1% in pinus thunbergii community. The distribution of the degree of green naturality(DGN) was 67% in the second-grade (cultivated land), 29.2% in 7th grade (second forest(A)) and 1.8% in 6th grade (plantation). It was estimated that phytomass of Pinus densiflora and Pinus thunbergii in the study sites, which was calculated by Montreal model, was 657,817.2 and 177,367.0 ton, respectively.

Mid-Span Spectral Inversion 기법을 채택한 장거리 광 전송시스템에서의 비트 에러율 평가

이성렬,김남성,방효창 한국항행학회 2002 韓國航行學會論文誌 Vol.6 No.3

본 논문에서는 MSSI 보상 기법을 채택한 2,000km 광 전송 시스템의 수신 성능 평가를 위해 신호간의 간섭 영향을 고려한 직접 검파 수신단 에서의 잡음 전력과 비트 에러율을 도출하고, 비트율에 따른 수신 감도를 계산해 보았다. 본 논문에서 제안한 BER 계산이 실제 시스템에 적용될 수 있는 방법이라는 것을 확인할 수 있었고, 전송 링크에 MSSI 보상 기법이 적용된 시스템에서 신호 파형의 색 분산과 비선형 효과에 의한 왜곡이 보상되지만, 결국 비트율이 높아질수록 좁아지는 비트 간격에 따른 ISI에 의해 평균 수신 전력의 감소를 가져오고 궁극적으로 수신 감도를 감소시켜 준다는 것을 확인할 수 있어다. In this paper, we induced that the noise powers and bit error rate of direct detection receiver taking account of ISI (intersymbol interference) in the 2,000 km optical transmission system. And we evaluated the sensitivity in the vrious bit rate system. We verified that the proposed calculation method is applicable to the exact optical system. And we confirmed that the signal distortion due to both chromatic dispersion and nonlinear effects compensated by using of MSSI(Mid-Span Spectral Inversion) method, and yet the sensitivity of a higher bit rate system is reduced, because of the increase of ISI and then the decrease of the average receiving power, compared with a the lower bit rate system.

위 유문동 평활근세포의 Caffeine 활성화 전류에 미치는 Ascorbate의 효과

이무열,방효원,엄대용,이상돈 중앙대학교 의과대학 의과학연구소 1992 中央醫大誌 Vol.17 No.4

In order to observe the effects of ascorbate on the background current in pyloric circular smooth muscle cells, caffeine of which action was fairly clarified, was used to induce the current systems. To block all of the known currents, various blocking agents were added in the external bathing solution. A part of pyloric circular muscle tissue was excised out, and enzymatic isolation technique was used to obtain Ca^2+ -tolerant single circular muscle cells. The whole cell mode of patch-clamp experiment was conducted. The results were as follows : 1. Ascorbate induced the increase of inward currents in the hyperpolarized potential ranges, and quite a large increase of outward currents in the depolarized ranges. 2. Caffeine also induced similar results, but the magnitude of outward current was smaller than that of assorbate in the depolarized ranges. 3. These phenomena were disappeared by addition of the anion channel blocker. 4. Replacement of external NaCl with NMG·Cl was rarely affected the effects of ascorbate and and caffeine. But the effects of ascorbate and caffeine were almost abolished when sxternal Cl^- was substituted for aspartate. These results suggested that ascorbate affected chloride current which thought as a component of the background currents in the pyloric circular smooth muscle cells.

위 평활근 세포의 활동전압을 이루는 CI^-전류성분에 관한 연구

방효원,이종찬,이무열,엄대용,이상돈 중앙대학교 의과대학 의과학연구소 1993 中央醫大誌 Vol.18 No.3

Chloride current has been known as a part of backgroud current. Recently, its roles in the maintenance of action potential have much attention. The purposes of the present study are clarifying the chloride current component which might play an important role in generation and maintenance of the action potential in the pyloric circular smooth musele cells. We used the whold cell voltage clamp techniques to assess the current and voltage responses induced by caffeine superfusion. The results were as follow: 1. Caffeine superfusion induced the increase of inward currents in the hyperpolarized potential ranges, and the increase of outward currents in the depolarized ranges. 2. Sodium ion removal from the external medium and the addition of cadmium ion rarely affected these current response. 3. Duration of the action potential was elongated by application of the caffeine and modified by the change of the intracellular chloride ion concentraion. 4. The effect of caffeine superfusion on the action potential disappeared by the addition of the anion channel blocker. The results suggest that caffeine superfusion may prolong the duration of repolarized phase of the action potential probably by the chloride current activation in the gastric antral smooth muscle.

주행차량에 의한 강교량의 충격계수에 관한 연구

김상효,이상호,김방래 연세대학교 산업기술연구소 1996 논문집 Vol.28 No.1

In this study, a finite element program which can perform the dynamic analyses of bridges by considering the interaction forces between the bridge and moving vehicle is developed. The impact factors and dynamic behaviors of bridges according to the various parameters, such as speed and weight of vehicles, span length, damping ratio, girder spacing and transverse stiffnesses of bridges, are studied. The impact factor, in general, increases as the traveling speed increases, whereas the weight of vehicle does not affect the impact factor. The impact factor is larger in exterior girders than in interior girders. As the spacing between two girders increases, the impact factor decreases, and it is also affected by the lateral rigidities of the bridges. In addition, the impact factor is smaller in continuous bridges than in simply supported bridges.

위 유문동 평활근 세포에서 Caffeine에 의해 활성화되는 이온 전류에 관한 연구

정인원,이무열,방효원,엄대용,이상돈 중앙대학교 의과대학 의과학연구소 1992 中央醫大誌 Vol.17 No.3

In order to clarify the existence of the non-selective cationic channel of CI^- -channel in gastric antral smooth muscle cells which suggested to play a critical role in generation and maintenance of depolarization and exitability, the whole cell mode of patch-clamp experiment was conducted. Following results were obtained ; 1. Puff injection of caffeine induced the increase of inward currents in the hyperpolarized holding potential ranges, and the increase of outward currents in the hypopolarized range. 2. In the case of blocking of all known currents, these current components were observed. 3. These current components were disappeared when known as a Cl^- -channel blocking agent was treated and intracellular EGTA concentration was increased. The above results could be concluded that these current components strongly suggested as a Ca^2+ -dependent Cl^- current in the gastric antral smooth muscle cells.

위 윤상근 세포의 Ca^2+-의존성 K^+-전류에 미치는 Ascorbate의 효과

배정원,이무열,방효원,엄대용,이상돈 중앙대학교 의과대학 의과학연구소 1991 中央醫大誌 Vol.16 No.2

In order to observe the effect of ascorbate on the Ca^2+-activated K^+ current in pyloric circular muscle cells which plays a critical role in generation and maintenance of repolarization and automatism, apart of pyloric circular muscle tissue was excised out, digested in collagenase containing Ca^2+-free physiological solution to get single circular muscle cells and the whole cell mode of patch-clamp experiment was conducted. Following results were obtained : 1. Oscillatory outward current was reduced by ascorbate in case of high intrapipette Ca^2+ concentration in whole voltage range and was enhanced in case of low intrapipette Ca^2+ concentration. 2. Oscillatory outward current was reduced in Ca^2+-free physiological solution with calcium channel blocker and not effected by ascorbate. 3. There were no qualitative differences among the control and ascorbate-treated group in effects of pH, steady state inactivation and the remaining component of the outward current. The above results could be concluded that ascorbate effects calcium-dependent component of the oscillatory outward current in the pyloric circular smooth muscle cells.

Ca^(2+)―작동성 Cl^-전류에 미치는 이차 전령들의 효과

송인섭,이무열,방효원,엄대용,이상돈 중앙대학교 의과대학 의과학연구소 1993 中央醫大誌 Vol.18 No.3

The anion movements across the cell membrane were regarded as apart of passive distribution according to the cation movements. Recently, from the developement of patch clamp technique new concept for anion channels were introduced. And their roles in the genesis of action potential and resting potential were noticed. So we clarified the existence of the chloride channel in the smooth muscle cells and studied its nature in regard to the roles of the second messangers. We used the whold cell voltage clamp technique to study the current responses induced by carbachol application in the circular smooth muscle cells of the gastric antrum of the rabbit. The results were as follows; 1. Application of the carbachol induced the increase of inward currents in the hyperpolarized potential ranges, and the increase of outward currents in the depolarized ranges. 2. Even in the cases of blocking all the known currents, these current components were observed. 3. Sodium ion removel from the external medium rarely affected these current responses, and the addition of cadmium ion did not make any remarkable change. 4. Known second messangers such as c-AMP, c-GMP, heparin, A1F_4 rarely affected these current components. 5. Lowering of intracellular calcium ion concentration drastically reduced these current responses. Form the above results we can suggest that the carbachol induced current responses contained chloride currents which were activated by only intracellular calcium ion, not by any other second messegers in the gastric antral smooth muscle cells.

저 분극된 심근에 미치는 Vanadate의 효과

서성옥,방효원,조성일,엄대용,이상돈 중앙대학교 의과대학 의과학연구소 1987 中央醫大誌 Vol.12 No.3

Effects of vanadate on the isometric contraction, membrane potential and its maximal rate of depolarization of rabbit ventricular papillary muscles were recorded in normal Tyrode solution and 19mM K^+ Tyrode solution. Following results were obtained: 1. Vanadate increased the isometric contractions in normal Tyrode and 19mM K^+-Tyrode solution in a dosedependent manner. 2. Vanadate increased the duration and Vmax of slow action potential. 3. Vanadate induced slight hyperpolarization of unstimulated quit preparations in normal and high K^+-Tyrode solution. 4. Effects of vanadate which were observed in K^+-depolarized preparations were reversed by diltiazem, a calcium channel blocker. It could be conciuded that vanadate has positive intropic effect by increasing Ca-current in the papillary mucles of the rabbit.

마산만의 하수기인 유기물 fecal sterol의 분포

최민규,문효방,김상수,이윤 한국환경과학회 2005 한국환경과학회지 Vol.14 No.5

Surface sediments and seawater were sampled at Masan and Haengam Bays of Korea, to evaluate contamination by sewage-derived organic matter using fecal sterols. Six stream-water samples into Masan and Haengam Bays were also sampled. Total concentrations of eight sterols (coprostanol, epichloestanol, epicoprostanol, cholesterol, cholestanol, brassicasterol, stigmasterol and β-sitosterol) were in the range of 1,274~4,768 ㎍/g dry weight in suspended particulate from the stream-water, 292-2,244 ㎍/g dry weight in suspended particulate from the seawater and 4.5~27.2 ㎍/g dry weight in the sediments. Although sterol compositions in sediments, seawater and stream-water were different, cholesterol was the predominant sterol in all samples. The proportion and concentration of coprostanol, a sewage tracer, in stream-water was much higher than those in sediment and seawater. The sterol levels including coprostanol in the sediments and seawater were higher at inner basin than at the outer bay. Some molecular indices and multivariate statistical analysis were used to assess the origin of these sterols and sewage contamination in the study area. The sterol composition patterns in stream-water were mainly associated with contamination by sewage-derived organic matters and those of seawater were associated with the activities of marine-originated organisms. Sterol levels in the sediments were both from the sewage input through stream-water and the marine-originated organisms. This survey suggests that the main source/route of sewage-derived organic matters in Masan Bay is the input of stream-water into the bay.