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        검색결과 1,157

        1.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        It was found in this study that fluorinated microporous carbon aerogels with enhanced hydrophobicity could be successfully prepared by direct fluorination to separate water-in-oil emulsions at high flux. The fluorinated carbon aerogel (F-CA) surface treated by the fluorination method had a water contact angle of 151.2° and could immediately absorb oil. In addition, the unique network structure of F-CA and its hydrophobicity allow surfactant-stabilized water-in-oil emulsions to be effectively and simply separated under gravity without requiring external forces such as vacuum or pressurization. The network structure of F-CAs consists of randomly connected spherical particles that form fluorinated permeation channels, which induce high flux during emulsion separation. The F-CA spherical particles have nanosized pores and high hydrophobicity, which repel and trap water droplets to increase the separation purity. Therefore, F-CA exhibited excellent performance, such as high filtrate purity (up to 99.9954%) and flux (up to 11,710 L/m2h). Furthermore, F-CA reusability was demonstrated as it did not lose its hydrophobicity and maintained its performance even after repeated use. This type of aerogel has great potential to be utilized throughout various environmental fields, including oil remediation.
        4,200원
        2.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this work, we have designed a novel gas inlet structure for efficient usage of growth and doping precursors. Our previous gas injection configuration is that the gas is mixed to one pipe first, then divided into two pipes, and finally entered the chamber symmetrically above the substrate without a jet nozzle. The distance between gas inlet and substrate is about 14.75 cm. Our new design is to add a new tube in the center of the susceptor, and the distance between the new tube and substrate is about 0.5 cm. In this new design, different gas injection configurations have been planned such that the gas flow in the reactor aids the transport of reaction species toward the sample surface, expecting the utilization efficiency of the precursors being improved in this method. Experiments have shown that a high doping efficiency and fast growth could be achieved concurrently in diamond growth when methane and diborane come from this new inlet, demonstrating a successful implementation of the design to a diamond microwave plasma chemical vapor deposition system. Compared to our previous gas injection configuration, the growth rate increases by 15-fold and the boron concentration increases by ~ 10 times. COMSOL simulation has shown that surface reaction and precursor supply both have a change in determining the growth rate and doping concentration. The current results could be further applied to other dopants for solving the low doping efficiency problems in ultra-wide-band-gap semiconductor materials.
        4,600원
        3.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, the effect of Distribution efficiency through the fishery production base distribution center (FPC) on the production site board facility was studied. FPC is a new distribution system for Korean fishery products that has been promoted in earnest since 2012, and in this study, the effect before and after the introduction of FPC was analyzed using the DID (Difference in Difference) model for the effect of FPC in the fishery industry. The results of analysis shows that in the case of Wando Geumil FPC, the volume and unit price of consignment sales decreased during the analysis period, which was statistically significant. In the case of Sokcho FPC, the volume of consignment sales decreased during the analysis period, which was statistically insignificant. But the unit price of consignment sales rose during the analysis period, which was statistically significant. In the case of Gyeongju FPC, the volume of consignment sales increased during the analysis period, which was statistically significant at the 90% confidence level. But the unit price of consignment sales fell during the analysis period, which was statistically significant.
        5,700원
        7.
        2024.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The challenge of incorporating photothermal conversion function into chitosan (CS) hybrid fibers lies in balancing functionality and mechanical properties. In this study, we successfully prepared a chitosan/graphene oxide/gelatin (CS/GA/GO) hybrid fiber using the wet spinning process, achieving improved mechanical properties and efficient photothermal conversion capabilities. When compared with pure CS fiber with a breaking strength of 1.07 cN/dtex, the breaking strength of the CS/ GA composite fiber increased by 46.73%, while the CS/GA/GO hybrid fiber showed an even greater increase of 85.98%. In addition, the introduction of gelatin (GA) led to secondary scattering of near-infrared light, enhancing the photothermal conversion efficiency. As a result, the CS/GA/GO hybrid fiber exhibited a faster temperature rise rate and higher maximum temperatures (94.3 °C, 103.0 °C, and 111.3 °C) as compared to the CS/GO hybrid fiber. The successful incorporation of GA not only improved the mechanical properties but also enhanced the photothermal performance of the hybrid fiber.
        4,200원
        8.
        2024.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : This study investigates the effects of three different three-color arrow traffic light operations on right-turn vehicles at intersections in Busan Metropolitan City. METHODS : Intersections in this study were categorized as general intersections (Type 1), intersections with right-turn pockets (Type 2), and intersections with scramble crosswalks (Type 3), and were investigated in terms of the efficiency (i.e., control delay) and safety (i.e., number of conflicts) of right-turn vehicles by employing VISSIM 2023 and SSAM3. RESULTS : From a mobility perspective (i.e., control delay), the protected/permitted operation outperformed the other two methods at the three types of intersections. The protected operation, similar to the results of the protected/permitted operation, was also superior to the permitted operation in terms of safety (i.e., number of conflicts). CONCLUSIONS : Protected/permitted operation has been proven to be a more efficient and safer measure than other operation methods for alleviating the problems of protected right-turn operation, which is currently implemented without three-color arrow traffic lights.
        4,000원
        9.
        2024.04 구독 인증기관·개인회원 무료
        노지 나방류 해충인 담배거세미나방 방제를 위한 유충기생성 천적 2종인 긴등기생파리와 예쁜가는배고치벌 의 방사조건을 확립하고자 콩 재배포장에서 방사거리 및 방사밀도별 기생율을 조사하였다. 긴등기생파리는 방사 후 24시간 이내 방사지점으로부터 10m까지 이동하여 나방류 유충을 기생하였으며, 예쁜가는배고치벌도 방사지점으로부터 15m에서도 기주유충에 산란하여 고치가 형성된 것이 확인되었다. 긴등기생파리는 면적당 방사밀도가 높아질수록 기생율이 증가했으며, ㎡당 0.15마리(천적:해충=1:5) 방사했을 때 평균기생율 63.1%로 나타났다. 예쁜가는배고치벌은 긴등기생파리와 같은 방사밀도에서 평균기생율 47.8%로 확인되었으나, 방사 밀도에 따른 기생율 차이는 없었다.
        10.
        2024.04 구독 인증기관·개인회원 무료
        The baculovirus expression system (BES) utilize the p10 or polyhedrin promoter, a very late promoter that exhibits strong transcriptional activity primarily at the end of viral infection, to produce useful recombinant proteins. The burst sequence of the very late promoter is essential for strong transcription, and VLF-1 is a transcription factor that binds specifically to the burst sequence, and it has been reported that it can regulate the amount and timing of expression of protein by the very late promoter. Recently, a VLF-1 constitutively expressing cell line was constructed to increase the production of the target protein, but the effect was minimal. In this study, to find the optimal VLF-1 expression conditions to increase target protein production efficiency, we controlled the expression of VLF-1 through various promoters and evaluated the target protein expression efficiency by the p10 promoter accordingly.
        11.
        2024.04 구독 인증기관·개인회원 무료
        우리나라에서 공용중인 시설물은 총 172,111개로 집계되고 있으며, 그 중 교량은 34,199개로 사회 기반시설 중 가장 많은 비중을 차지한다. 이러한 교량은 공용하중, 온도, 습도 등에 의해 거더간 신축 량이 발생하게 되고 신축량 발생으로 인한 유간거리에 대해 차량의 통행 안정성 및 주행성 확보를 위 한 신축이음장치를 설치하게 된다. 신축이음장치를 설치하여 차량의 통행 안정성 및 주행성을 확보할 수 있지만 누수 및 퇴적물 낙하 등을 직접적으로 방지하지 못하여 고무지수재를 별도로 설치하게 된 다. 하지만 이러한 고무지수재는 다양한 원인에 의해 쉽게 손상이 발생한다. 손상된 고무지수재를 통 해 거더의 부식, 교량하부 인명사고 등 다양한 2차 피해가 발생할 수 있다. 피해방지를 위한 교량의 유지관리를 지속적으로 수행하고 있지만 고무지수재 특성상 지속적인 교체가 불가피한 실정이다. 따라 서 본 연구에서는 기존 신축이음장치에 활용되는 고무지수재의 문제점을 해결하기 위하여 초탄성 형 상기억합금을 활용한 새로운 지수재 개발 연구를 수행하였다. 이에 대해 초탄성 형상기억합금 지수재 와 고무지수재에 대한 유한요소해석을 수행하고 비교 및 분석하였으며, 하중 제거 후 원형으로 복원되 는 효과를 통해 지속 사용 가능한 지수재 연구를 검증하였다.
        12.
        2024.04 구독 인증기관·개인회원 무료
        본 연구에서는 유도가열기법을 활용한 콘크리트 촉진 발열양생 기술의 효율성을 평가하기 위하여 철근 배근 및 전도체 변수에 따른 유도가열에 의한 콘크리트 온도향상 성능 및 압축강도를 평가하였 다. 먼저 철근 자체의 유도가열 성능을 평가한 결과, 주철근 및 나선철근 모두 유도가열 직후 10분 이 내에 목표온도인 70℃에 도달하여 충분한 가열성능을 나타내었다. 주요변수로 나선철근의 유무, 나선 철근의 간격, 피복두께, 거푸집 종류, 시험체 크기의 변수를 고려하여 15시간의 유도가열 발열양생 후 압축강도 평가를 실시하였다. 평가 결과, 철근을 포함한 경우 유도가열 발열양생 효율이 약 20~85% 만큼 증가하였다. 또한 총 6종(강섬유, 비정질강섬유, 전기로슬래그, 탄소섬유, 탄소나노튜브, 흑연나노 섬유)의 전도성 재료를 선정하여 재료 자체의 유도가열을 통해 발열성능을 평가하였다. 평가결과 강섬 유, 비정질강섬유, 전기로슬래그는 1~7분 사이에 가열 목표온도인 70℃에 근접하게 도달하여 유도가 열에 의한 콘크리트 발열성능을 향상 시킬 수 있는 혼입재료로 최종 선정하였다. 이상의 3가지 전도체 를 혼입하여 콘크리트를 타설한 뒤 15시간 유도가열 후의 압축강도를 평가한 결과, 강섬유 1%를 혼 입한 경우 발열양생을 실시하지 않은 상온양생에 비하여 강도가 186% 증가하였고, 잔골재의 50%를 전기로 슬래그로 치환한 경우 발열양생을 실시하지 않은 상온양생에 비하여 강도가 187% 상승하였다.
        13.
        2024.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 논문은 분점정부 하에서 국회 효율성을 ‘공공선택론(Public Choice)’ 의 관점에서 분석하였다. 기계·경제적, 사회·정치적 등 다양하게 측정되 는 효율성의 개념을 살펴보고, 국회 효율성을 국회 위원회 제도, 대통령 거부권, 국회의원의 활동 및 국회 의안 처리를 기준으로 분석하였다. 구 체적으로 뷰캐넌과 톨록의 집단의사결정에 관한 이론을 근거로 국회의 위원회 중심주의 운영제도가 어떻게 효율성을 제공하는지를 분석하였다. 또한 거대 양당의 대결 구도가 더 심각해지는 분점정부(여소야대) 구조가 국회 효율성에 미치는 영향을 대통령 거부권 제도와 연계하여 분석하였 다. 본 연구는 제21대 국회 상반기는 단점정부로, 하반기는 분점정부 구 조라는 데 주목하면서, 대통령 거부권 행사, 국회의원의 활동, 국회의 의 안 처리 등을 각각 비교·분석하였다. 제21대 국회의 효율성은 단점 정부 인 상반기가 하반기보다 상대적으로 높게 나타났다. 분점정부에서 나타 날 수도 있는 국회 효율성이 상쇄된 것은 여야의 양당 정쟁 구조가 대통 령과 국회의 극단적인 대결 구도로 굳어지고 있다는 것을 시사한다.
        6,300원
        14.
        2024.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, in order to analyze the water purification efficiency according to the influent water conditions of artificial wetlands, the purification efficiency was compared at two points where sewage treatment water flows in and one point where good effluent flows in. As a result of reviewing the results of the analysis of influent and effluent and the removal efficiency, the T-N and T-P removal efficiency was calculated at 54.7% and 77.4%, respectively, for the two points where sewage treatment water was treated, the treatment efficiency of SS 90.8%, BOD 51.1%, TOC 30.6%, T-N 38.8%, T-P 55.3% was shown. As a result, the efficiency of removing pollutants in the artificial wetland was found to be proportional to the concentration of influent water, and in order to create an efficient artificial wetland, it is judged that thorough review and management at the design stage are necessary considering that the removal efficiency of high-concentration contaminated water was high.
        4,200원
        15.
        2024.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study evaluated the effectiveness of odor reduction when spraying inside the Bio-curtain (hereinafter referred to as curtain) according to the exhaust fan operating rate. Spraying is a main factor affecting the ability to odor reduction of curtains. The curtain (total area: 37.9m3) was constructed with two layers of light-shielding screens stretched over a rectangular parallelepiped structure installed around an exhaust fan (630 mm) on the side wall of a pig barn. Air samples for odor analysis were collected from inside the pig barn and outside the curtain. The main odorous compounds such as volatile fatty acids, phenols, indoles, and ammonia were measured. The odor reduction effectiveness was evaluated by total odor activity values (TOAVs) summed to the odor activity values of each odorous compounds. Depending on the exhaust fan operating rate, the reduced rate of TOAVs gradually decreased to the range between 15.67% and 68.80%. Because the contact time between the spraying liquid and the air velocity of the exhaust fan becomes shorter (or there is a reduction in liquid to gas flow ratio) as the exhaust fan operating rate increases. The results of this study can be used as basic data for research into spraying conditions to improve the odor reduction effectiveness of curtains.
        4,000원
        16.
        2023.12 구독 인증기관 무료, 개인회원 유료
        Port operational efficiency is considered as one of the most important competitive factors and plays a critical role in the port development all over the world, especially container ports. Haiphong Port, which is in the northern of Vietnam, is planned to become one of the national and regional ports. To do this objective, it is important to analyse the operational efficiency of its container terminals. The paper aims to comparatively analyse the operational efficiency of 16 container terminals in Haiphong Port from 2016 to 2022 by basic and Malmquist DEA models. With 112 observations collected and calculated in R software, DEA models have five inputs (container yard area, number of quay crane, berth draft, berth length, labour force) and one output (annual cargo throughput). Consequently, Hai An, Tan Vu, and Vip Greenport are more efficient terminals over the 7-year period, whereas Transvina and MIPEC have lower efficiency. Paper contributions are the literature review about port operational efficiency and references to propose resolutions in next author’s research as well as masterplans to develop Vietnam seaport’s system. Besides, the limitations are discussed as the number of observations and environmental factors in ports.
        4,300원
        17.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aimed to a sign device using quantum dot film. We synthesized quantum dots with an absolute quantum yield of more than 95% using the solution process method, coated the quantum dot film by mixing it with acrylate resin, made a sign device, and studied the improvement of visibility, and obtained the following conclusions. Quantum dots with absolute quantum yield of 97.63% at 535 nm and 97.85% at 615 nm were synthesized by doping InP with GaP and stacking ZnSe and ZnS composite shells. The synthesized quantum dots were mixed with acrylate syrup at a weight ratio of 10% to coat a film with a luminance uniformity of more than 95%, and the quantum dot film was attached to a luminous display with an insulation capacity of 500 V, an insulation resistance of 99.9 GΩ, and a luminance of 688.5 ㏅/㎠ at white region and 122.3 ㏅/㎠ at red region.
        4,000원
        18.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 중국의 사천성과 중경시의 공항을 대상으로 공항의 이용효율성을 분석 하고 있다. 본 연구의 투입변수는 터미널 면적, 게이트 수 그리고 개통 노선 수를 이 용하였다. 그리고 산출변수는 여객운송량, 화물운송량 그리고 운항 횟수를 이용하였 다. 분석방법은 Malmquist지수를 이용하고 분석대상은 자료의 일치성을 고려하여 사 천성과 중경시의 14개 공항을 설정하였다. 분석기간은 코로나19 기간을 포함하여 20 13-2022년으로 설정하였다. 분석결과는 아래 세 가지로 요약할 수 있다. 첫째는 2013 -2022년 분석기간 중 사천성과 중경시의 14개 공항의 이용효율성은 전반적으로 악화되고 있다. 둘째는 여객중심의 공항의 이용효율성이 화물중심 보다는 상대적으로 높 게 나타나고 있다. 셋째는 분석대상 공항들을 등급별로 구분하면 4F급 공항의 이용 효율성이 4D급이나 4C급 보다 상대적으로 낮게 나타나고 있다. 4F급 공항은 인프라 적인 측면에서 4D급이나 4C급 보다 상대적으로 양호한 조건을 가지고 있다. 그러나 공항의 이용효율성 분석결과에 의하면 상대적으로 낮은 효율성을 가진다. 따라서 4F 급 공항의 이용효율성의 개선은 향후 과제이기도 하다.
        6,400원
        19.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Considering the characteristics of aldehydes among volatile organic compounds, a combined process was established by linking an absorbent and a photocatalytic reactor. Experiments to find the optimal operating conditions of the combined process showed that as the amount of photocatalyst coating increases, the wavelength of the ultraviolet lamp used becomes shorter, the photodegradation rate becomes faster, and the removal efficiency increases. It was also demonstrated that by controlling the relative humidity during the connection process of the combined process, the re-evaporation phenomenon at the front end (absorption area) of the hybrid process can be improved and the removal efficiency at the back end (photocatalytic reaction area) can be significantly enhanced. This confirmed the need for a combined process that complements the advantages and disadvantages of each process.
        4,000원
        20.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        It is very important to evaluate how the functions of products, facilities, and spaces affect human life. The evaluation of these actions has legal regulations such as certification, inspection, and diagnosis, and the degree of quality, safety, and excellence of the results is announced. This study sought to secure safety through efficient system operation by reviewing safety-related certification systems established and implemented by each government department in Korea and analyzing the characteristics of each system and similarities between systems. There was also an aspect of cross-checking safety through the certification and diagnosis system implemented by each ministry, but it was confirmed that the efficiency of the system should also be considered in terms of overlapping application. Therefore, when securing safety is confirmed based on each safety-related law, active alternatives such as exemption, substitution, delegation, etc. should be presented.
        4,000원
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