검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 268

        82.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In vivo assay of glucose detection was described using a skin tattoo film electrode (STF), and the probe was made from carbon nano tube paste modification film paper. Here in the square-wave stripping anodic working range obtained of 20-100 mgL-1 within an accumulation time of 0 seconds only in sea water electrolyte solutions of pH 7.0. The relative standard deviations of 50 mg glucose that were observed of 0.14 % (n=12), respectively, using optimum stripping accumulation of 30 sec, the low detection limit (S/N) was pegged at 15.8 mg/L. The developed results can be applied to the detect of in vivo skin sensing in real time. Which confirms the results are usable for in vitro or vivo diagnostic clinical analysis.
        4,000원
        83.
        2017.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The production amount can be increased by shortening the work process time, and the stability of the worker can be secured by the development of the transfer control system. The production time can be shortened and the introduction of production can be speeded up, and the production quantity is doubled. The length of the product is changed according to the product package, and the length of the product has reached 15m. Developed a feed straight line automatic adjustment feeder to reduce the defect rate to less than 4%.
        4,000원
        85.
        2017.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, FLUENT v.16.1 was used to investigate the compressible flow generated by the supersonic jet spewed from a high pressure tube. As the boundary condition for CFD (Computational Fluid Dynamics) analysis, the inlet temperature of air was constantly 300 K and the variation of JPR (Jet Pressure Ratio) were 5, 50, 100, 150 and the variation of tube diameter were 10, 20, 30 cm. As a result, it was confirmed that the effective range was increased as the JPR was higher, but it was confirmed that the effective range was lower than the JPR rise, and that the effective range was increased as the diameter was larger. Therefore, it is found that the tube diameter is more sensitive than the JPR among the influence factors of jet, and if the result of this study were reflected in the design of high pressure system, it will contribute to the design of the system for preventing the second accident.
        4,000원
        86.
        2017.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        분리막 오염을 감소시키고 투과유속 향상을 위하여 관형분리막 모듈 내에 공기 분사노즐관을 삽입시켰다. 분리막 의 평균 기공크기는 0.1 μm이며 이스트를 오염물질로 사용하였다. 모든 투과실험은 노즐관을 모듈에 장착하고 공기를 주입 하지 않는 실험을 먼저 실시하고 연속해서 공기를 주입하는 투과실험을 하였다. 그 다음 노즐관을 제거한 후 공기를 주입시 키지 않으면서 투과유속을 측정하였다. 측정된 투과유속은 공기주입 효과를 분석하기 위하여 비교하였다. 공기주입에 대한 투과유속은 거의 일정하거나 증가하였다. 노즐관이 장착되고 공기 주입을 하지 않을 경우의 투과유속이 빈 관형 모듈의 경우 보다 높았다. 운전압력을 0.4 bar까지 감소시키면 노즐관이 장착되지 않는 경우와 비교하여 공기를 주입할 경우 투과유속이 21%까지 향상되었다. 기체량이 증가하여 기/액체 2상 흐름이 stratified-smooth에서 intermittent 상태로 변화됨에 따라서 공기 주입에 의한 투과유속은 30% 이상으로 증가하였다
        4,000원
        87.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Coal Ash, a byproduct of coal combustion in power plants, is usually disposed in surface impoundments or wet disposal areas and landfill sites. Toxic substances contained in coal ash which slowly seep into the groundwater and aquifers in nearby impoundments, and which are also dispersed by wind and storm water in landfill sites, lead to serious health and environmental effects. The main focus of this study is to analyze the strength characteristics of the recycled coal ash mixed with dredged soil to test its capabilities from external forces such as in the stacking of geotextile tubes. The SEM and XRF analysis were carried out in order to grasp the grain size and composition of the coal ash and the dredged soil. To find the optimum mixing ratio of the coal ash and dredge soil, the type of deformation and the strength of the different mixtures were obtained by performing a uniaxial compression test. The relationship between the compressive stress and deformation of the uniaxial compression test and the tubular structure formed by injecting the coal ash into geotextile tube was confirmed and the applicability of the geotextile tube reinforced with the recycled and improved fill material is very high.
        4,000원
        89.
        2016.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This paper is about improvements to prevent the crack on welding parts of bleed air duct and vent tube in Advanced Trainer ECS owing to vibration. The configurations and the path of vent tube should be changed to prevent the crack. To assure the result of improvements, measured the status of each pressure condition attaching pressure censers on duct and vent tube. The result of life analysis shows that a crack does not happen on improved configuration while a crack initiates after 19th flight and thru cracking could happen after the 30th flight on previous configuration.
        4,000원
        90.
        2016.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The electric flexible videoscope was developed. The developed components of the videoscope are insertion tube, 360 degrees full articulation tip with joystick control, detachable probe part, camera module equipped with CMOS sensor and adjustable high-intensity white LED light sources. The insertion tube can have strong torsional rigidity from the components of spiral spring and tungsten mesh tube. The handset with joystick control makes it possible to manipulate the videoscope tip articulation in 360 degrees of all directions easily. Over 90 degrees of bending angle measured from the straight camera probe makes it possible to inspect the surface of side wall. The detachable probe model can separate insertion tube with probe. It is useful to select proper length of insertion tube. Several tests were performed to check the development objectives.
        4,000원
        91.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 시험은 만개기 기온(15~40oC) 및 생장조절제(GA4+7 +BA와 prohexadione-calcium) 살포가 국내 주요 사과 품종(‘후지’, ‘쓰가루’)과 국내에서 육성한 품종들(‘추광’, ‘감홍’, ‘홍안’, ‘홍금’, ‘홍로’, ‘홍소’, ‘화홍’, ‘섬머드림’, ‘선홍’)의 화분 발아율 및 화분관 신장에 미치는 영향을 조사하고자 실시하였다. 15oC부터 25oC까지 온도가 올라갈수록 화분 발아율과 화분관 신장 길이는 증가되었으나, 30oC 이상의 고온은 화분 발아율과 화분관 신장 길이를 억제시켰다. 30oC 이상의 고온에서 화분 발아율과 화분관 신장 길이가 가장 높았던 국내 육성 사과품종은 ‘선홍’이었다. GA4+7+BA 살포는 무처리구에 비해 화분 발아율 및 화분관 신장 길이를 증진시켰으나, 이러한 효과는 40oC에서 발생하지 않았다. prohexadione-calcium 살포는 화분 발아율과 화분관 신장 길이에 영향을 주지 않았다. 결론적으로, 사과나무 만개기 기온이 30~35oC 정도로 높아지면, 인공수분 후 GA4+7+BA를 살포하는 것이 착과 증진에 좋을 것으로 판단되었다.
        4,000원
        92.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The steel I-girder inserted circular steel pipe is a new structural cable-anchorage system that the circular guide pipe is connected and welded to the web of the I-girder for cable-stayed bridge. This guide pipe-anchor system has many merits of the structural and aesthetic performances. However, there has been little research into the behavior mechanism with respect to anchor angles and the strengthening methods against the sectional area reduction caused by the penetration of guide pipe. Therefore, this paper investigates an experimental behavior of the steel I-girder with circular steel tube which is fabricated 1/3 scale model as fundamental study to examine the flexural behavior and failure mode in the laboratory. Based on the comparison of test results and nonlinear FE analyses, it is found that FEM is suitable to estimate the stiffness of I-girder with circular tube in order to design the cable-stayed bridge.
        4,000원
        93.
        2016.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was investigated heat flow and heat transfer coefficient characteristics of around tube when changing the tube arrangement type and heat transfer area. When  ≒1∼4, convective heat transfer coefficient of staggered and aligned arrangement was increased. Growth rate of the heat transfer coefficient becomes smaller in case of ≒5∼8 because a change in the turbulence was very small. At the staggered arrangement, all tubes were always arranged in front of the open passage between the back of the tube. Then, the entire surface area of the tube was exposed to the main flow. Thus growth rate of heat transfer coefficient appear larger than aligned arrangement.
        4,000원
        94.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to investigate the influence of moisture removal using a moisture condensation tube on the odor concentration, when sampling a malodorous substance from an odor discharge facility’s emission sites. For high-temperature and humid gas streams, the odor concentration was decreased through the use of a moisture condensation tube. The multiple odor concentration of the high-temperature and humid gas streams emitted from boiler-burning equipment decreased from a 3,000 to a 1,221 dilution factor when using one or two moisture condensation tube. This multiple odor concentration was further decreased to a 1,000 dilution factor by using two moisture condensation tubes and glass beads, and also was decreased to a 374 dilution factor by using two moisture condensation tubes and silicagel. Among the designated offensive odorous substances, ammonia, trimethylamine and acetaldehyde that have high solubility in water showed high reduction rate of their concentration. Compared to the result using a sampling tube only, the concentration was decreased by 94.8% ~ 97.7% for ammonia, by 87.5% ~ 95.9% for trimethylamine and by 100% for acetaldehyde. The findings of this study indicate that sampling using a moisture condensation tube affects the concentration of multiple odors. Therefore, it is considered that using a sampling tube only for emissions sampling enhances analytical accuracy and precision rather than using moisture condensation tube with sampling tube, even for the emissions containing moisture.
        4,000원
        95.
        2016.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This work investigated the decomposition of aqueous anatoxin-a originated from cyanobacteria using an underwater dielectric barrier discharge plasma system based on a porous ceramic tube and an alternating current (AC) high voltage. Plasmatic gas generated inside the porous ceramic tube was uniformly dispersed in the form of numerous bubbles into the aqueous solution through the micro-pores of the ceramic tube, which allowed an effective contact between the plasmatic gas and the aqueous anatoxin-a solution. Effect of applied voltage, treatment time and the coexistence of nutrients such as NO3 -, H2PO4 - and glucose on the decomposition of anatoxin-a was examined. Chemical analyses of the plasma-treated anatoxin-a solution using liquid chromatography-mass spectrometry (LC-MS) and ion chromatography (IC) were performed to elucidate the mineralization mechanisms. Increasing the voltage improved the anatoxin-a decomposition efficiency due to the increased discharge power, but the energy required to remove a given amount of anatoxin-a was similar, regardless of the voltage. At an applied voltage of 17.2 kV (oxygen flow rate: 1.0 L min-1), anatoxin-a at an initial concentration of 1 mg L-1 (volume: 0.5 L) was successfully treated within 3 min. The chemical analyses using LC-MS and IC suggested that the intermediates with molecular weights of 123~161 produced by the attack of plasma-induced reactive species on anatoxin-a molecule were further oxidized to stable compounds such as acetic acid, formic acid and oxalic acid.
        4,200원
        96.
        2016.04 구독 인증기관 무료, 개인회원 유료
        In the blast work inevitably exists a vacant space between drilling hole wall and explosive. So it cause an blast inefficiency called on a decoupling effect. In this study, For enhancing the detonation efficiency and reducing the environmental problem(vibration, noise, etc.), water is used to fill the vacant space. Water filling has many advantages such as efficiency, low price and workability. In the comparison analysis the field test is carried out. It result on an aspect of the effectiveness and safety. The result measured in the field is as follows; First, the water tube blast reduces the vibration by 16.5% and lessen the noise by 1% comparing to general blast. Secondly, water tube blast makes a separation distance shortened by maximum 15m. Thirdly, in the case that the same quantities of explosive are used, the amount of crushing per hole increased by about 12.8% in water blast method. The quantity of the explosive is reduced by about 11.4% comparing with general blast.
        4,000원
        97.
        2016.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : The field application and performance of continuously reinforced concrete pavement (CRCP), constructed by using the mechanical tube-feeding method, are evaluated in this study. METHODS: The location of the rebar was evaluated by using the MIRA system. The early-age CRCP performance was evaluated via visual survey, in which the crack spacing and crack width were examined. RESULTS: The location of longitudinal reinforcing bars was evaluated via MIRA testing and the results showed that the longitudinal rebars all lie within a given tolerance limit (±2.5 cm) of the target elevation. In addition, owing to the low temperature when the concrete was pured, the crack spacing in the Dae-Gu direction is slightly wider than that of the Gwang-Ju direction. Almost all of the crack spacings lay within the range of 1.0 m~3.0 m. A crack width of <0.3 mm was measured at the pavement surface. However, as revealed by the field survey, the crack spacing was not correlated with the crack width. CONCLUSIONS : In CRCP constructed by using the mechanical tube-feeding method, almost all of the longitudinal reinforcing bars lay within the tolerance limit (2.5 cm) of the target elevation. The concrete-placing temperature affects the crack spacing, owing to variations in the zero-stress temperature. Crack survey results show that there is no correlation between the crack spacing and crack width in CRCP.
        4,000원
        98.
        2016.02 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to evaluate the performance of a tube and badge type NO2 passive air sampler. The principle of the method is a colorimetric reaction of NO2 with N-1-naphthylethylendiamine under acidic conditions. The sampling rates for the tube and badge type passive air samplers was determined 12.3 ± 4.4 mL/min and 27.3 ± 4.9 mL/min, respectively, as obtained from the slope of the linear correlation between the NO2 mass collected by the passive air sampler and the NO2 concentration with the NO2 analyzer. The tube and badge type passive air sampler were moderately correlated with a correlation coefficient of 0.9112. The measurement for the precision and accuracy of the passive air sampling was carried out with duplicate measurement of passive air samplers. The passive air sampler had good precision and accuracy for measuring NO2 in atmosphere. A good correlation was observed between the passive air sampler and the NO2 analyzer with a coefficient of determination of 0.9153 (tube type) and 0.9514 (badge type). This passive air sampler would be suitable for the NO2 concentration monitoring in atmosphere.
        4,000원
        99.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, the heat flow characteristics of natural convection was theoretically analyzed with time by changing various locations of heat trace with tube surface about enclosed circular tube by applying nominal tube diameter 90 mm of KS D 3507. Before carrying out CFD (Computational Fluid Dynamics) analysis, it is presumed that the boundary condition is the tube’s inside and outside fluid temperature of 273 °K, the tube surface heat flux according to the heat trace location of 16 W/m. The result confirmed that water of inside tube is occurred natural convection caused by density difference depending on temperature profile. Additionally, in case of heat trace location, the heat transfer and flow characteristics showed clearly that two-heat trace location =135° and 180° was more favorable distribution than one-heat trace appropriate location =135°.
        4,000원
        100.
        2015.11 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        A dynamic tube pressure method was proposed for a liquid level measurement. The reliability of our in-house manufactured prototype level measurement system was investigated for water samples in a vial as a preliminary study. The prototype instrument, equipped with a stepper motor and a differential pressure sensor, was used to measure the travel distance of the tube from an initial zero position to the liquid surface. Unlike a conventional bubbler method, our dynamic tube pressure method is based on the abrupt changes in the tube pressure to directly detect the liquid surface. Optimum conditions were determined from the measurements of the travel distance with different-sized tubes at various ambient base pressures and various descending tube speeds. In addition, we proposed a gravimetric calibration method. In the gravimetric calibration method, the travel distances are used instead of the liquid level, which can be obtained from the measurement data of the travel distance. The travel distance versus the weight calibration curve showed a good linear relationship (R2 = 0.9999), and standard deviations of the travel distance over the whole range of experimental conditions were less than 0.1 mm. In a further study, our present system will also be used in the measurement of density and surface tension by minimizing the contact time with high-temperature and highly-corrosive molten salts.
        4,000원
        1 2 3 4 5