• 약학회지
• /
• 제31권1호
• /
• pp.33-39
• /
• 1987

In order to elucidate the defence mechanism of Cyprinus carpio nudus to Clonorchis sinensis, clonorchicidal substance in the epidermal mucus of this fish was isolated by silica gel column and thin layer chromatography and analyzed for its chemical nature by UV, IR and NMR-spectroscopy. The epidermal mucus of the fish was extracted by ethyl ether and separated into 2 fractions by column chromatography using petroleum ether/chloroform(30/70,v/v) as first solvent and methanol as second solvent. The second fraction with greyish white colour showed clonorchicidal effect. The second was again fractionated into greyish white precipitate and clonorchicidal greenish yellow supernatant fraction, by adding petroleum ether and standing the mixture for 5 days at $5^{\circ}C$. The latter was divided into 7 fractions in column chromatography with acetone/ benzene (10/90, v/v) as carrier. The fraction on equivalent to the spot of Rf. 0.225 value among them disclosed the strongest clonorchicidal effect. By this purification procedure, clonorchicidal substance was purified 154-fold with 0.9% yield from the mucus of the fish, and 10mg of the final fraction killed tne metaceicariae in 22 min. Infra red, nuclear magnetic resonance and ultraviolet spectrometric analysis of the purified substance revealed that the substance is linoleic acid. According to the results of the present studies it seemed that this fish could not be proper intermediate host of Clonorchis sixensis, and that defence mechanism of this fish to the worm seems to be correlated with clonorchicidal substance in epidermal mucus.

• KIEAE Journal
• /
• 제9권5호
• /
• pp.77-84
• /
• 2009

This study was initiated by the fact that Kangwon Land and large sized resorts was failed the financial benefit to the local residents. This research analyzed the best important tourist resource among the main tourist resource by perception interviewing local residents and related professionals. This study shows that the leisure resource was most important resource field in Jeong-Seon. So more attention to the leisure resources and investment them. Among natural attraction resources 'Hwa-Ahm cave and Hwa-Ahm mineral water' is estimated to have most potential for the strategic financial support. In leisure sector 'High One resort' is judged to be more important attraction resource by professionals but a case of local residents 'Dong-gang Rafting' and 'Rail Bike' were estimated more important resources rather than 'High One resort;. Lastly, in cultural resources, although the importance is a bit behind natural attraction and leisure resources, 'Jeong-Seon 5th day market' and 'Araree village' should be the core linking other related cultural resources. In order to activate tour industry and development of Jeong-Seon area, it is necessary to find identify of regional owned attraction resources and to build tourist attraction infra structure by selecting core bases of existing major attraction points and linking other various resources to those core bases.

• Geomechanics and Engineering
• /
• 제21권2호
• /
• pp.153-164
• /
• 2020

Tunnel excavation in shallow soft ground conditions of urban areas experiences inevitable surface settlements that threaten the stability of nearby infrastructures. Surface settlements during shield TBM tunneling are related to a number of factors including geotechnical conditions, tunnel geometry and excavation methods. In this paper, a database collected from a construction section of Hong Kong subway was used to analyze the correlation of settlement-inducing factors and surface settlements monitored at different locations of a transverse trough. The Pearson correlation analysis result revealed a correlation between the factors in consideration. Factors such as the face pressure, advance speed, thrust force, cutter torque, twin tunnel distance and ground water level presented a modest correlation with the surface settlement, while no significant trends between the other factors and the surface settlements were observed. It can be concluded that an integrated effect of the settlement-inducing factors should be related to the magnitude of surface settlements.

• KEPCO Journal on Electric Power and Energy
• /
• 제7권2호
• /
• pp.295-299
• /
• 2021

Recently, interest in maintenance has been increasing due to the enlargement and aging of infra structures. Therefore, a new paradigm is required to secure and improve the durability of structures differentiated from the past. Accordingly, research on smart concrete incorporating the concept of self-healing into concrete is being actively conducted. In this study, the crack healing performance and durability performance of self-healing concrete applied with a hydrogel containing biomineral-forming microorganisms were evaluated. As a result of evaluating the dispersion of the hydrogel in concrete, it was confirmed that the hydrogel was well distributed in concrete matrix with a dispersion coefficient of 0.35 to 0.46. The crack healing performance evaluation was verified by a water permeability test, and showed a recovery rate of 95% or more at the age of 28 days, confirming the applicability of self-healing concrete. The durability performance of self-healing concrete was evaluated in terms of resistance to penetration of chloride ion and freezing and thawing. Regardless of the mixing of the hydrogel, the same level of durability performance was shown for various compressive strength level. Therefore, it was confirmed that the microbial admixture did not affect concrete durability. In the future, long-term crack healing performance and durability verification studies should be supplemented.

• 한국산업융합학회 논문집
• /
• 제26권6_2호
• /
• pp.1073-1082
• /
• 2023

Thermal sensors, also called thermal infrared wavelength sensors, measure temperature based on the intensity of infrared signals that reach the sensor. The infrared signals recognized by the sensor include infrared wavelength(0.7~3.0㎛) and radiant infrared wavelength(3.0~100㎛). Infrared(IR) wavelengths are divided into five bands: near infrared(NIR), shortwave infrared(SWIR), midwave infrared(MWIR), longwave infrared(LWIR), and far infrared(FIR). Most thermal sensors use the LWIR to capture images. Thermal sensors measure the temperature of the target in a non-contact manner, and the data can be affected by the sensor's viewing angle between the target and the sensor, the amount of atmospheric water vapor (humidity), air temperature, and ground conditions. In this study, the characteristics of three thermal imaging sensor models that are widely used for observation using unmanned aerial vehicles were evaluated, and the optimal application field was determined.

• 한국수자원학회:학술대회논문집
• /
• 한국수자원학회 2009년도 학술발표회 초록집
• /
• pp.1494-1498
• /
• 2009

세계기상기구(WMO)에 의하여 홍수예경보시스템의 평가를 위하여 개발된 MOFFS Ver.3의 개선을 위하여 특정유역의 홍수방어체계의 취약성을 평가하고 홍수방어시스템의 완성도를 높이기위한 DSS-FOP를 개발하였다. DSS-FOP는 지점별, 홍수사상별로 예보시스템 운영결과를 간단한 평가양식에 나타내는 시스템이며, 홍수방어구조물(Flood control infra)과 홍수조절운영(Flood control operation)으로 분류한다. 홍수방어구조물은 수문관측, 홍수방어구조물, 홍수조절지휘소로, 홍수조절 운영은 자료처리 및 전송, 홍수예측모형, 예경보발령의 총 6가지 주요평가항목과 하부의 23가지 세부평가항목으로 구성하였다. 점수부여체계는 최대점수, 목표점수, 성과점수, 부족점수, 취약점수의 산정을 통하여 구조물인프라와 운영측면에서의 시스템취약부분을 평가 진단할 수 있도록 하였다. 개발된 DSS-FOP를 이용하여 국내의 한강유역과 UN/ESCAP 태풍위원회의 회원국인 태국의 Khlong U-Taphao 유역을 대상으로 적용하고 그 결과를 비교 평가하였다. 한강유역의 경우 하천정보센터 신설 및 조직강화로 인적자원측면에서 높은 성과점수를 보였으며, 향후 수문레이더 설치 등으로 관측분야에서의 개선이 기대된다. 태국의 Khlong U-Taphao 유역의 경우 목표수준을 다소 조정할 필요가 있으며, 비상행동계획의 마련이 시급하다. 더불어 홍수방어구조물에 대한 지속적인 투자가 필요한 상황이다. 이러한 DSS-FOP의 평가결과는 국가별, 유역별, 호우사상별로 관리되며, 태풍위원회 회원국의 적용 및 기술지침의 작성을 위해 많은 평가 및 조사가 축적되어야 한다.

• 대한환경공학회지
• /
• 제31권12호
• /
• pp.1089-1094
• /
• 2009

도시화에 따른 불투수면적의 증가가 도시지역의 유출량 증가에 미치는 영향을 SWMM (Storm Water Management Model) 모델을 미국 프린스턴 대학 캠퍼스에 적용하여 분석하였다. 도시지역의 하수관거망을 고려하여 정밀한 지형 및 인프라 자료를 구축하기 위하여 모형의 유역을 격자 형식으로 제시하고, GIS를 활용하여 지형인자를 추출하였다. 모델의 격자망은 구축 자료의 사용 용이성 및 활용도를 높이기 위하여 200${\times}$200 ft (60.96${\times}$60.96 m)의 정사각형 형태의 131개의 소유역으로 구성하였다. 적용성이 검토된 도시지역의 SWMM 모델을 이용하여 도시화에 따른 불투수면적의 증가가 지표면 유출에 미치는 영향을 예측하기 위하여 불투수면적이 50% 및 100%로 증가했을 경우의 유출량 증가를 검토하였다. 도시화에 따른 불투수 면적의 증가로 인하여 초기 강우시 유출량의 증가율 평균이 가장 높게 나타났으며 최대 강우 강도시에 최대 증가율을 보였다.

• 한국터널지하공간학회 논문집
• /
• 제15권6호
• /
• pp.547-557
• /
• 2013

전단응력에 의한 전단강도 및 모드 II 파괴인성은 이산화탄소 지중저장에서의 덮개암 및 주입층의 안정성 평가에 활용되는 중요한 인자들이다. 본 연구에서는 짧은 보 압축시험을 이용하여 코코니노 사암의 전단강도 및 모드 II 파괴인성을 측정하였다. 측정된 평균 전단강도는 23.53 MPa이며, 모드 II 파괴인성은 1.58 MPa${\surd}$m이다. 응력확대계수(stress intensity factor)는 변위외삽법(displacement extrapolation method)을 이용한 유한요소법으로 결정하였다. 또한 이축응력(biaxial stress)과 수분포화(water saturation)가 모드 II 파괴인성에 미치는 영향을 분석하였다. 그 결과 이축응력이 증가할수록 파괴인성도 증가하였고, 완전포화된 시험편의 파괴인성은 건조상태의 파괴인성보다 대략 11.4% 감소하였다.

• Environmental Engineering Research
• /
• 제25권4호
• /
• pp.579-587
• /
• 2020

Novel silane grafted bentonite was obtained using the natural bentonite as precursor material. The material which is termed as nanocomposite was characterized by the Fourier Transform Infra-red (FT-IR) and X-ray diffraction (XRD) methods. The surface imaging and elemental mapping was performed using Scanning Electron Microscopic (SEM/EDX) technique. The electroanalytical studies were performed using the nanocomposite electrode. The electroactive surface area of nanocomposite electrode was significantly increased than the pristine bentonite or bare carbon paste based working electrode. The impedance spectroscopic studies were conducted to simulate the equivalent circuit and Nyquist plots were drawn for the carbon paste electrode and nanocomposite electrodes. A single step oxidation/reduction process occurred for As(III) having ΔE value 0.36 V at pH 2.0. The anodic stripping voltammetry was performed for concentration dependence studies of As(III) (0.5 to 20.0 ㎍/L) and reasonably a good linear relationship was obtained. The detection limit of the As(III) detection was calculated as 0.00360±0.00002 ㎍/L having with observed relative standard deviations (RSD) less than 4%. The presence of several cations and anions has not affected the detection of As(III) however, the presence of Cu(II) and Mn(II) affected the detection of As(III). The selectivity of As(III) was achieved using the Tlawng river water sample spiked with As(III).

• 한국군사과학기술학회지
• /
• 제20권4호
• /
• pp.528-535
• /
• 2017

Fuel cells have been spotlighted in the world for being highly efficient and environmentally friendly. A hydrogen which is the fuel of fuel cell can be obtained from a number of sources. Hydrogen source for operating the polymer electrolyte membrane fuel cell(PEMFC) in the current underwater environment, such as a submarine and unmanned underwater vehicles are currently from the metal hydride cylinder. However, metal hydride has many limitations for using hydrogen carrier, such as large volume, long charging time, limited storage capacity. To solve these problems, we suggest diesel reformer for hydrogen supply source. Diesel fuel has many advantages, such as high hydrogen storage density, easy to transport and also well-infra structure. However, conventional diesel reforming system for PEMFC requires a large volume and complex CO removal system for lowering the CO level to less than 10 ppm. In addition, because the preferential oxidation(PROX) reaction is the strong exothermic reaction, cooling load is required. By changing this PROX reactor to hydrogen separation membrane, the problem from PROX reactor can be solved. This is because hydrogen separation membranes are small and permeable to pure hydrogen. In this study, we conducted the pressurized diesel reforming and water-gas shift reaction experiment for the hydrogen separation membrane application. Then, the hydrogen permeation experiments were performed using a Pd alloy membrane for the reformate gas.