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        검색결과 95

        1.
        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
        2.
        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.
        3.
        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
        4.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The spectrum of this study was research on the closed hydroponic cultivation of netted melons (Cucumis melo L.) using coir substrate, analyzing the impact of this cultivation method on melon yield, fruit quality, and the efficiency of water and nutrient usage. The experimental results showed that the average fruit weight of the melons grown in a closed system was 71.4 g higher than that of the open system, and the fruit width was on average 0.2 cm larger, showing a statistically significant difference. However, there was no difference in the average sugar content of the fruit flesh and height. Although there is no substantial commercial difference, it is conjectured that the change in the macronutrients ratio in the irrigation has played a role in the statistically significant increase in fruit weight, which is attributed to changes in the crops' nutrient uptake concentrations. This necessitates further research for a more comprehensive understanding. In terms of the productivity of irrigation required to produce the fruit, applying the closed system resulted in an increase of 7.6 kg/ton compared to the open system, saving 31.6% of water resources. Additionally, in terms of nutrients, cultivating in a closed system allowed for savings of approximately 59, 25, 55, 83, 76, and 87% of N, P, K, Ca, Mg, and S, respectively, throughout the entire cultivation period. As the drainage was reused, the ratios of NO3 - and Ca2+ increased up to a maximum of 9.6 and 9.1%, respectively, while the ratios of other ions gradually decreased. In summary, these results suggest that closed hydroponic cultivation can effectively optimize the use of water and fertilizer while maintaining excellent fruit quality in melon cultivation.
        4,000원
        5.
        2023.10 구독 인증기관·개인회원 무료
        표면발현(surface-display system)은 세포 또는 바이러스 표면에 목적 단백질을 고정하여 발현시킴으로써 목적 단백질에 대하여 독립적인 공간 구조 및 생물학적 활성을 부여하는 단백질 공학 기술이다. 또한 이를 이용하여 높은 중화항체 유도 및 대량생산이 가능한 삼량체의 형태로 항원 단백질의 발현 또한 가능하다. BES(baculovirus expression system)에서의 표면발현 기술은 번역 후 수정과정 및 복잡한 구조의 다양한 단백질의 발현이 가능하기 에 다른 숙주 기반 시스템보다 효율적이라고 보고되고 있다. 그러나 목적 단백질 외의 다른 표면 단백질과 발현 공간에서의 경쟁으로 목적 단백질의 낮은 생산량이 큰 문제점으로 지적되고 있다. 따라서, 이러한 BES에서 표면 발현의 생산 효율을 증대시키기 위하여, 동일한 표면 공간에 대한 단백질 간의 발현 경쟁에 대해 실험적으로 확인 후, 그를 해결하기 위하여 표면발현에 최적인 목적 단백질 발현을 위한 프로모터 선발 실험을 수행하였다. 이를 통해 BES에서 표면발현에 의한 목적 단백질의 생산 효율을 증대시킬 수 있음을 확인하였다.
        9.
        2022.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, we propose a standardized design method using dimensionless design factors (specific catchment area, specific storage capacity) for the catchment area and storage tank capacity for the installation of rainwater facilities under rainfall conditions in Korea. As a result of simulating the water-saving efficiency of rainwater facilities that supply toilet flushing water in 17 office buildings in the metropolitan area, it was confirmed that the specific catchment area is a major design factor affecting the water-saving efficiency. In order to achieve the annual water-saving efficiency of 30%, it was evaluated that the specific catchment area and the specific rainwater storage capacity required 0.2 or more, respectively. In addition, when looking at the monthly water-saving efficiency, it is estimated that 100% of the required water demand can be supplied for up to three months from July to September under optimal conditions. Due to the annual rainfall variation, there is a limit to using all of the collected rainwater as toilet flushing water. Consideration of temporary use for other purposes should be reflected in the design stage of the building considering the characteristics of the target building and local conditions. In the future, follow-up studies are needed for field verification of dimensionless design and efficiency evaluation based on water supply and demand.
        4,000원
        10.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        With the advent of the 4.0 era of logistics due to the Fourth Industrial Revolution, infrastructures have been built to receive the same services online and offline. Logistics services affected by logistics 4.0 and IT technology are rapidly changing. Logistics services are developing using technologies such as big data, artificial intelligence, blockchain, Internet of things, and augmented reality. The convergence of logistics services and various IT new technologies is accelerating, and the development of data management solution technology has led to the emergence of electronic cargo waybill to replace paper cargo waybill. The electronic waybill was developed to supplement paper waybill that lack economical and safety. However, the electronic waybill that appeared to complement the paper waybill are also in need of complementation in terms of efficiency and reliability. New research is needed to ensure that electronic cargo waybill gain the trust of users and are actively utilized. To solve this problem, electronic cargo waybill that combine blockchain technology are being developed. This study aims to improve the reliability, operational efficiency and safety of blockchain electronic cargo waybill. The purpose of this study is to analyze the blockchain-based electronic cargo waybill system and to derive evaluation indicators for system supplementation.
        4,300원
        11.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This experiment evaluated the efficiency of mechanical ventilation, one of the measures to reduce indoor radon concentration in residential spaces. In the most popular ventilation rates of the air conditioning system, the most efficient air conditioning system was confirmed by checking the time when the radon concentration reached the lowest level, the radon reduction rate, and the radon concentration that could be lowered as much as possible. The results showed a reduction rate of up to 80% or more as a result of conducting the experiment by blocking the inflow of outside air. It was confirmed that the time to reach the lowest concentration after starting the mechanical ventilation was about 6 hours to a maximum of 7 hours. Therefore, this study verified that indoor radon concentrations can be efficiently reduced by using a mechanical ventilation system.
        4,000원
        12.
        2020.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        High concentrations of PM2.5 were generated in new apartments before moving in, and PM2.5 reduction efficiencies using air cleaners and ventilation systems were evaluated. The experimental results for different air cleaner capacities showed that the PM2.5 reduction efficiencies for 46.2 m2, 66 m2, and 105.6 m2 areas were 81.7%, 92.9%, and 92.5%, respectively. Thus, the larger the air cleaning application area, the higher the PM2.5 reduction efficiency. However, there was no difference in the efficiency of overcapacity air cleaners above a certain capacity. The efficiencies of air cleaners located at the living room center, interior wall, and edge were 81.7%, 79.2%, and 75.8%, respectively. There was, therefore, no significant difference in the PM2.5 reduction efficiencies of air cleaners in different locations. Furthermore, the PM2.5 reduction efficiencies at distances of 1 m, 2 m, and 3 m were 81.7%, 81.3%, and 81.7%, respectively. Therefore, there was also no significant difference in efficiency with distance. The PM2.5 concentration decreases rapidly during natural ventilation. Therefore, when the indoor PM2.5 is higher than the outdoor PM2.5, the air cleaner should be used after natural ventilation. The efficiency of PM2.5 reduction using an air supply-type ventilation system in apartments was 35%, which is not high. The simultaneous operation of the ventilation system and kitchen range hood was effective, showing a PM2.5 reduction efficiency of 69.1%. However, a water sprayer was not effective, showing a PM2.5 reduction efficiency of 24.3%. The results of this study suggest that PM2.5 reduction performance should be standardized by evaluating the efficiency of different ventilation systems. Effective usage and maintenance standards for ventilation systems need to be disseminated, and ventilation systems and air cleaners should be used effectively.
        4,000원
        13.
        2020.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The cooking-generated particles are major indoor sources of air pollution. Recently, the performance of the range hood is focused on particle removal performance. Range hood with an auxiliary air supply system can improve the fine and ultrafine particles removal efficiency by making a supply air during cooking activities. The particles were measured in the experimental building by varying ventilation types. Only operating range hood during the cooking activities was not enough to reduce the cooking-generated particles. Despite operating range hood systems, fine and ultrafine particle concentrations were maintained when cooking was finished. The range hood with a make-up air supply system can reduce the indoor particle concentration below background conditions when those systems were operated after cooking. In this study, the assessment of cooking-generated particle removal efficiency of the range hood with an auxiliary air supply system was conducted. The removal efficiency of ultrafine particles showed trends similar to the removal efficiency of fine particles.
        4,000원
        14.
        2020.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 주류공장 내 고농도 CO2 제거 및 포집을 위해 L-alanine 흡수제를 적용하여 CO2 흡수, 탈리 효율을 평가 후 재생 성능을 확인하였다. 탈리공정의 효율적인 처리를 평가하기 위해 실험 실 규모에서 Hot plate, Steam 두가지 탈리 방법을 비교하였으며 Hot plate는 약 10%, Steam의 경우 약 60%의 재생효율을 확인하였다. 따라서 주류공장 내 100m3/min 실증화 규모에 Steam-Tower 탈리공정을 적용하여 최적조건을 평가한 결과 탈리 유량 4L/min 이하, Steam 온도 160℃ 이상, 탈리효율 85.5%로 확 인할 수 있었다.
        4,000원
        15.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 합성가스의 에너지화를 위한 가스엔진 성능 평가를 수행하였다. 회전수 1800 rpm 조건에서 공기과잉률이 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6 증가에 따른 엔진출력(kWm)과 열효율(%)을 평가한 결과, 공기과잉률 λ 1.4에서 엔진출력 34 kWm를 나타냈으며, 공기과잉률이 증가할수록 엔진 열효율은 전반적으로 감소하는 경향을 보였다. 엔진출력 34 kWm 조건에서 공기과잉률이 1, 1.1, 1.2, 1.3, 1.4 증가시 열효율이 34.2%, 36.9%, 37.2%, 37.4%, 38.1%로 증가하였고, 발전출력을 통한 종합효율은 발전출 력 30 kWe 부하조건에서 38.7 kg/h의 연료를 소모하여 32.1%의 발전효율과 냉각수와 배기가스에서의 열 회수를 통해 57.3 kW의 폐열을 회수하여 53.8%의 열을 회수하여 총 85.8%의 종합효율을 보이는 것으로 나타났다.
        4,000원
        16.
        2019.06 구독 인증기관 무료, 개인회원 유료
        Along the 3,200km-long coastline, Vietnam has a significant number of seaports, which are relatively large and named as the keys to economic development. However, most ports are relatively small with obsolete facilities and poor supporting services. Among three largest ports countrywide, Ho Chi Minh City seaport has had the highest throughput and productivity per annum of the country for years, assumed the role of the major port in the south, where cargos and containers come and go from all industrial parks in the southern region. Situated on what was the outskirts but is now the outskirts or suburbs of Ho Chi Minh City, it has however shown some drawbacks, i.e., expansion of the port is not an option regardless of the high throughput. Apart from the inadequate infrastructure, ports are facing another setback due to backward pricing. The rapid increase in number of ports also created a “race to the bottom” situation, where Vietnam ports have reduced their price to attract customers. The direct results are lower service quality and an inability to reinvest into port development. Therefore, the restructuring of Ho Chi Minh City seaport system has been launched since 2006 whereby the plan not only resolves the limited size, obsolete facilities and traffic issues, but also becomes more efficient as the new port complex is located conveniently among the region’s industrial parks and export processing zones of Ho Chi Minh City, Binh Duong, Dong Nai, and Ba Ria – Vung Tau. In line with this plan, the paper will mainly aim to provide the outstanding constraints which Ho Chi Minh City seaport system faced, including illogical distribution among ports/terminals regardless the scale, capacity and geographic locations; ineffective and insecured mooring and anchorage buoys; undeveloped logistic services centres and lack of connecting infrastructure. As so, the recommendations for single issue will be provided.
        4,000원
        17.
        2019.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We developed a wet scrubber by applying cyclone flow to the gas flow and using a spiral filter structure. While the size of a new scrubber was about half that of a conventional scrubber, the device showed relatively high efficiency in pollutants removal such as particulate matter and compounds inducing odor. The new scrubber installed in a plating industry showed a higher removal efficiency of about 5% for dust, about 23% for hydrogen chloride, and about 23% for sulfur dioxide compared to the conventional scrubber. Plurality of tubes in the spiral filer housing are arranged to be vertically shifted from each other. Because the upward residual gas does not directly rise vertically, the residence time of gas between the filter plates is extended. Thus, the purification efficiency of the pollutants was enhanced in the new scrubber. In addition, the new scrubber developed in this study is more cost effective because the cost saving in manufacturing it compared with a conventional scrubber increases with increasing the size of equipment. It is expected that a scrubber with better dust collecting efficiency can be obtained by carrying out a study in connection with facilities capable of controlling acidity of washing water.
        4,000원
        19.
        2019.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was successfully achieved out the optimized system for dispersing and mixing condition of resin liquid. The flow analysis was simulated according to the shape of the impeller and the stirring tank using ANSYS software and optimized in advanced design. As a result, it was confirmed that the shape and double number of the impeller on the flow field are influenced better effects in a range of mixing and diffusion areas comparing to single number of impeller. It was considered that stirring was performed more quickly and efficiently under the condition of double numbers and saw tooth type impeller. This result can be applied practically for the mixing tank in the industrial application and avaliable used to make a new system for painting equipment.
        4,000원
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