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        검색결과 79

        65.
        1971.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The forth dye diffusion experiment, which was authorized by the Office of Atomic Energy, and some physical aspect of oceanographic observations were carried out in the sea off Kori in September 29-October 1, 1971. In a series of drift bottle experiments the 337 bottles were released. And bottom topography by echo soundings in the survey was well approached to the chart No. 433, Kori and Approaches, published by Hydrographic Office in October 1970. Results deduced from this survey were as follows: 1. A small ridge extends from Kori-Mal tip in southwestward over 1300 meters, and eastside of which is plain and a little sloping while westside of which cliffy and very steeper sloping. 2. A gyre was formed in the waters from Kori-Mal to Mat-dum in cum sole definitely at flood tide and in contra solem less definitely at ebb tide. And that the gyre rose and decayed with the turn of the tide. 3. Diffusion coefficients of 2.5% Rhodamine B solution of 200 liters were 9. 3 ×102 cm2/sec in the waters Kori-Mal to Mat-dum and 28.6×102 cm2/sec in the waters eastside of Mat-dum at the time after 26 minutes from releasing of the dye solution. 4. According to the above results the eastside of Mat-dum is rather recommendable to settle as the point for the outlet of drainage or waste of atomic power plant to be constructed.
        4,000원
        67.
        2019.06 KCI 등재 서비스 종료(열람 제한)
        본 연구에서는 Geant4 application for tomographic emission (GATE) 시뮬레이션 프로그램을 통해 설계 된 male adult mesh (MASH) 팬텀의 영상을 획득한 후 다양한 필터링 인자가 설정된 FNLM 노이즈 제거 알고리즘을 적용함으로써 그에 따른 영상 특성의 경향성을 알아보고자 한다. 이를 위해 GATE 시뮬레이션 프로그램을 통해 인체를 모사할 수 있는 MASH 팬텀을 설계하였다. 또한, 설계된 MASH 팬텀을 기반으로 MAT LAB 프로그램을 통해 복부영상을 획득한 후 0.005의 σ 값을 갖는 Gaussian noise를 추가하여 열화영상을 모델링하였다. 모델링 된 열화영상으로부터 제안하는 FNLM 노이즈 제거 알고리즘의 필터링 인자를 각각 0.005, 0.01, 0.05, 0.1, 0.5, 1.0 으로 설정하여 적용하였으며, 정량적 평가를 위해 FNLM 노이즈 제거 알고리즘이 적용된 영상들로부터 각각의 coefficient of variation (COV), signal to noise ratio (SNR) 그리고 contrast to noise ratio (CNR)을 측정하였다. 결과적으로, 0.05의 필터링 인자가 적용된 영상에서 가장 개선된 COV, SNR 그리고 CNR 값을 보였다. 특히, COV는 설정된 필터링 인자가 증가함에 따라 감소하였으며, 0.05 값 이후부터 거의 일정한 값을 나타내었다. 또한, SNR 및 CNR의 경우 필터링 인자가 증가함에 따라 증가하였으며, 0.05 값 이후부터 감소하는 경향을 보였다. 결론적으로, 열화 영상으로부터 FNLM 노이즈 제거 알고리즘 적용 시 적합한 필터링 인자를 설정해야 함이 증명되었다.
        68.
        2018.06 KCI 등재 서비스 종료(열람 제한)
        To establish initial response scenarios for nuclear accidents around the Kori nuclear power plants, the potential for radionuclide diffusion was estimated using numerical experiments and statistical techniques. This study used the numerical model WRF (Weather Research and Forecasting) and FLEXPART (Flexible Particle dispersion model) to calculate the three-dimensional wind field and radionuclide dispersion, respectively. The wind patterns observed at Gijang, near the plants, and at meteorological sites in Busan, were reproduced and applied to estimates of seasonally averaged wind fields. The distribution of emitted radionuclides are strongly associated with characteristics of topography and synoptic wind patterns over nuclear power plants. Since the terrain around the power plants is complex, estimates of radionuclide distribution often produce unexpected results when wind data from different sites are used in statistical calculations. It is highly probable that in the summer and autumn, radionuclides move south-west, towards the downtown metropolitan area. This study has clear limitations in that it uses the seasonal wind field rather than the daily wind field.
        69.
        2018.06 KCI 등재 서비스 종료(열람 제한)
        미국의 원전해체 지침서인 MARSSIM과 MARLAP에서는 의사결정 전 부지조사를 계획하고, 계획한 조사를 시행하는데 Data Life Cycle의 사용을 권장하고 있다. 부지조사 계획단계에서 설정되는 데이터품질목표(DQO)는 부지조사 수행 및 설계의 모든 측면에서 얻을 수 있는 데이터를 최선으로 활용하는 방법을 제시하고, 부지조사 계획을 체계화하여 공식적으로 중요한 의사결정을 내리는데 필요한 정보를 얻을 수 있도록 한다. DQO의 일곱 과정 중 5~7단계에서는 앞선 단계에서 수집한 정보를 이용하여 합리적이고 신뢰성있는 의사결정을 내릴 수 있도록 부지조사를 설계하는 과정이다. 이 과정 중 설정되는 회색영역은 관심핵종에 대한 조사단위의 평균농도가 실제로 DCGL을 초과하지 않음에도 불구하고, 초과한다고 판단하여 제염활동과 같은 추가적인 활동을 하도록 결정내리는 Type II 의사결정 오류로 인한 결과가 미약할 것으로 생각되는 농도범위로 정의된다. 회색영역은 부지에서 수집한 Sample에 속한 특정 핵종의 평균농도와, 규제한도로서 설정될 수 있는 잔류방사능 유도농도(DCGL)를 이용하여 정할 수 있다. 회색영역을 설정함으로써 가장 자원효율적으로 부지조사계획을 설정할 수 있으며 의사결정 오류에 대한 영향을 최소화 할 수 있다. 선행연구로 도출된 고리 1호기의 DCGL을 이용하여 회색영역을 설정하고, 이를 이용해 올바른 의사결정을 내릴 수 있도록 하는 Sample의 농도평가 방법을 제시하였다.
        70.
        2015.01 KCI 등재 서비스 종료(열람 제한)
        The characteristics of atmospheric dispersion of radioactive material (i.e. 137Cs) related to local wind patterns around the Kori nuclear power plant (KNPP) were studied using WRF/HYSPLIT model. The cluster analysis using observed winds from 28 weather stations during a year (2012) was performed in order to obtain representative local wind patterns. The cluster analysis identified eight local wind patterns (P1, P2, P3, P4-1, P4-2, P4-3, P4-4, P4-5) over the KNPP region. P1, P2 and P3 accounted for 14.5%, 27.0% and 14.5%, respectively. Both P1 and P2 are related to westerly/northwesterly synoptic flows in winter and P3 includes the Changma or typhoons days. The simulations of P1, P2 and P3 with high wind velocities and constant wind directions show that 137Cs emitted from the KNPP during 0900~1400 LST (Local Standard Time) are dispersed to the east sea, southeast sea and southwestern inland, respectively. On the other hands, 5 sub-category of P4 have various local wind distributions under weak synoptic forcing and accounted for less than 10% of all. While the simulated 137Cs for P4-2 is dispersed to southwest inland due to northeasterly flows, 137Cs dispersed northward for the other patterns. The simulated average 137Cs concentrations of each local wind pattern are 564.1~1076.3 Bqm-3. The highest average concentration appeared P4-4 due to dispersion in a narrow zone and weak wind environment. On the other hands, the lowest average concentration appeared P1 and P2 due to rapid dispersion to the sea. The simulated 137Cs concentrations and dispersion locations of each local wind pattern are different according to the local wind conditions.
        71.
        2015.01 KCI 등재 서비스 종료(열람 제한)
        The effect of the metal oxide catalyst in the dimerization of waste vegetable oil was investigated. The high efficiency and recyclability has allowed different metal oxides to be used as catalysts in numerous synthetic reactions. Herein, clay, aluminum, titanium, calcium, magnesium and silicon oxide micro/nanoparticles are used in a Diels-Alder reaction to catalyze the production of the dimer acids. The metal oxides assist the electron transfers during cyclization to produce the desired product. Liquid chromatography mass spectroscopy (LC-MS) and gel permeation chromatography (GPC) were used to verify the production of dimer acids. For the confirmation of cyclization, compounds were analyzed using the nuclear magnetic resonance (NMR) spectroscopy. From the analysis, silylated or pristine clay showed its effectiveness as a catalyst in dimerization. Furthermore, alumina and alumina/silica composite showed successful performance in the reaction to yield cyclic dimer acids. These result suggested that metal oxides and montmorillonite might be used in synthesis of dimer acids for the recycle of waste vegetable oils.
        72.
        2012.09 KCI 등재 서비스 종료(열람 제한)
        홍수 발생 시 모래하천의 수위-유량 관계가 고리형을 이룬다는 것은 많은 현장 계측을 통해 보고되어 왔다. 또한, 홍수파 해석이나 사련에서 사구로 변동되는 하상해석을 통해 고리형 수위-유량 관계의 원인이 규명되어서 고리의 형태나 진행 방향 등에 대해서는 이론적으로도 상당부분 입증되어 있다. 그러나 경사가 급한 자갈 및 암반으로 구성된 산지하천의 경우, 현장유량계측의 어려움과 관측 정확도의 문제로 고리형 수위-유량 관계에 대한 연구가 매우 드물었다. 본 논문은 자갈 및 암반 지형의 산지하천인 제주도 한천에서 2011년 태풍 무이파 때 계측한 홍수 유량을 바탕으로 수위-유량 관계를 구축하고, 자갈하천에서 형성되는 고리형 수위-유량 곡선을 분석하고자 한다. 유량계측 방식으로는 홍수기에 적합한 비접촉식인 전자파 표면유속계를 사용하여, 홍수의 상승기와 하강기의 유량을 시간 단위로 계측하는 데 성공했다. 계측결과 수위-유량관계에서 뚜렷한 고리 형상을 확인할 수 있었다. 그리고 고리의 이력이 모래하천과 정반대로 동일수위에서 상승기의 유량이 하강기의 유량보다 작은, 고리 경로의 역전 현상을 발견하였다. 이러한 역전현상은 자갈하천의 조도의 변화가 모래하천의 경우와 반대로 발생하는 데 기인하는 것으로 추정한다.
        73.
        2008.03 KCI 등재 서비스 종료(열람 제한)
        The fate of two cyclic ethers, THF(Tetrahydrofuran) and 1,4-Dioxane, in conventional biological wastewater treatment plants was investigated using sequential activated sludge process. Removal efficiency of THF were about 86% in average, which was greater than that of 1,4-Dioxane, 30%. However, it was not clear whether the removal of cyclic ethers in biological system was caused by microbial activity or not. Thus treatability tests were conducted by batch experiments. The effects of mixing, aeration and the addition of activated sludge on the removal of cyclic ethers were investigated in batch experiments. THF was totally removed by mixing and aeration in 24 hours while removal ratio of 1,4-Dioxane was at most 30% for the same period. This results could be ascribed to the differences in Henry's law constants between the two chemicals. In addition, biological degradation including biosorption was not obviously observed in these batch tests.
        74.
        2006.06 KCI 등재 서비스 종료(열람 제한)
        화원 지점의 홍수시 유량은 수위가 상승할 때와 하강할 때 동일한 수위에 대해 많은 차이를 나타내고, 이와 같이 이력효과의 크기가 클 경우에는 많은 오차가 발생할 수 있다. 유량 환산 오차를 줄이기 위해 낙동강 본류 화원 수위관측소 지점에 대한 고리모양 수위-유량 관계곡선을 작성하였다. 하천유량과 단순 환산된 유량의 편차를 계산하기 위해 부정류 모의 사례로부터 (수위, 유량) 자료쌍을 획득하여 단순 수위-유량 관계곡선식을 작성하였다. 이 관계에서 이탈하는
        76.
        1996.04 KCI 등재 서비스 종료(열람 제한)
        New thia-and diselena-crown ethers containing two suffer and selenium donor atoms have been prepared. And then, mercury (Hg^2+) ion-selective electrodes with PVC-plasticizer (STPB) based on some macrocycles as neutral carriers were also made. The electrochemical selectivities for various ions, and the effects for macrocycles, matrix of membranes, ratio of plasticizer to macrocycles, concentration and pH of test solution were investigated on the Hg^2+ ion selective electrodes. The 1,10-diselena-l8-crown-6-PVC-STPB (sodium tetraphenylborate) exhibited good linear responses of 28.2 ± 0.6 decade^-1 for Hg^2+ ion in the concentration ranges of 10^-2∼10^-6 M Hg^2+ ion. This electrode exhibited comparatively good selectivities for Hg^2+ ion in comparison with alkali and alkaline earth metal ions, some heavy metal ions and rare earth metal ion in the range of pH 2.5∼6.0. In addition, this electrode was applied as a sensor in the titration of Hg^2+ ion with I^- ion in water.
        78.
        1995.06 KCI 등재 서비스 종료(열람 제한)
        New two macrocyclic compounds using as carriers of liquid emulsion menbrame, have been synthesized. These reuslts provide evidance for the usefulness of the theory in designing the systems. The efficiency of selective transport for heavy metal ions have been discussed from the membrane systems that make use of SCN^- I^- , CN^- and Cl^- ion as co-anions in source phase and make use of S_2O_3^2- and P_2O_7^4- ion as receiving phase, respectively. The transport, rate of M(Ⅱ) was highest when a maximum amount of the M(Ⅱ) in the source phase was present as Cd(SCN)_2([SCN^-]=0.40M, Hg(SCN)_2([SCN^-]=0.40M) and Pb(CN)_2([CN^-]=0.40M). The Cd(Ⅱ) and Pb(Ⅱ) over each competitive cations were well transprted with 0.3M-S_2O_3^2- and 0.3M-P20_7^4 , respectively in the receiving phase. Results of this study indicate that two criteria must be met in order to have effective macrocycle-mediated transport in these emulsion system. First one must effective extraction of the M^n+ into the toluene systems. The effectiveness of this extraction is the greatest if logK for M^n+-macrocycle interaction is large and if the macrocycle is very insoluble in the aqueous phase. Second, the ratio of the logK values for M^n+-receiving phase (S_2O_3^2- or P_2O_7^4-) to M^n+-macrocycle (L_1 or L_2) interaction must be large enough to ensure quantitative stripping of M^n+(Cd^2+, Hg^2+ or Pb^2+) at the toluene receiving phase interface. L_1(3.5-benzo-10,13,18,21-tetraoxa-1,7,diazabicyclo(8,5,5) eicosan) forms a stable Cd^2+ and Pb^2+ complexes and L_1 is very insoluble in water and its Cd2^+ and Pb^2+ complex is considerably less stable than Cd^2+-(S_2O_3)_2^2- and Pb^2+-P_2O_7^4- complexe is On the other hand, the stability of the Hg^2+-L_1 complex exceed that of the Hg^2+-(S_2O_3)_2^2- and Hg^2+-P_2O_7^4- , and the distribution coefficient of L_2(5,8,15,18,23,26-hexaoxa-1,12- diazabicyclo-(10,8,8) octacosane) is much smaller than that of L_1. Therefore, the partitioning of L_2 is favored by the aqueous receiving phase, and little heavy metal ions transport is seen despite the large logK for Hg^2+-L_1 and M^n+(Cd^2+, Pb^2+ and Hg^2+)-L_2 interactions.
        79.
        1993.03 KCI 등재 서비스 종료(열람 제한)
        Result of this study indicate that two criteria must be met in order to have effective macrocycle-mediated transport in these emulsion system. First, one must effective extraction of the post transition metals, Cd^2+ Pb^2+ and Hg^2+,into toluene membrane. The effectiveness of this extraction is greatest if log K values for the metal-macrocycle interaction is large. Second, the ratio of the log K values for the metal ion-receiving phase to the metal ion-macrocycle interaction must be large enough to ensure quantitative stripping of the metal ion at the toluene phase interface. Control of the first step can be obtained by appropriate selection of macrocycle donor atom, substituents, and cavity radius. The second step can be controlled by selecting the proper complexing agent for inclusion in the receiving phase. The order of the transport, when using the several A^- species such as SCN^-,I^-,Br and Cl^- is the order of the changing degree of solvation for A^- and the transport of the metals is also affected by the control of concentration for receiving species because of solubility-differences. In this study, we can seperate each single metal ion from the mixture of Cd^2+, Pb^2+, and Hg^2+ ions by using the toluene membranes controlled by optimized conditions. Transport of the single metal is also very good, and alkaline and alkaline earth metals as interferences ions did not affect the seperation of the metals in this macrocycle-liquid membrances but transition metal ions were partially affected as interferences for the post transition metal ions.
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