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        검색결과 76

        1.
        2023.05 구독 인증기관·개인회원 무료
        There is a need to develop a quantitative residual water measurement method to reduce the measurement uncertainty of the amount of residual water inside the canister after the end of vacuum drying. Therefore, a lab-scale vacuum drying apparatus was fabricated and its characteristics were evaluated by performing vacuum drying experiments based on the amount of residual water, vacuum drying experiments based on the surface area of residual water, and vacuum drying experiments based on the energy of residual water using the lab-scale vacuum drying apparatus. As a result of the vacuum drying experiments, if the surface area of water is the same, the greater the amount of water, the greater the energy of the water, so more energy is transferred to the surface of the water. Therefore, more water evaporated, and the average temperature of the remaining water was higher. The larger the surface area of the water, the more energy it takes to vaporize it, so the faster it dries and the faster the drying time. Before ice formed, energy was actively transferred by conduction heat transfer from the top, center, and bottom of the water to provide the energy needed for the water to evaporate from the surface. However, no energy was transferred from the water just before it turned into ice. When vacuum drying water, you can dry more water if you dry it slowly over a longer period of time. Therefore, by using a vacuum pump with a low flow rate, the pressure can be lowered slowly to prevent ice from freezing, thereby improving the drying quantity. It was evaluated that there was a good agreement between the energy used when water evaporated and the energy absorbed from the surroundings to within about 4%. Therefore, if the energy absorbed from the surroundings is known, it is possible to evaluate the amount of water evaporated in vacuum drying.
        4.
        2022.05 구독 인증기관·개인회원 무료
        This study presents a rapid and quantitative sequential separation method for H-3 and C-14 isotopes with distillation apparatus in environmental samples released from nuclear facilities. After adding 200 mg of granulated potassium permanganate and 500 mg of sodium hydroxide in 100 mL of sample solution, the sample solution was heated until approximately 10 mL of distillate, and the distillate fraction was removed. The sample solution was heated again until a minimum 10 mL of additional distillate was collected. 10 mL of distillate was transferred to the LSC vail and the measurement sample for H-3 was made by adding 10 mL of Ultima Gold LLT to the LSC vial. After adding 2.5 g of potassium persulfate, 2 mL of 1M silver nitrate and 15 mL of concentrated nitric acid to the remained sample solution, the sample solution was heated for 90 minutes and C-14 isotopes were adsorbed into 10 mL of Carbo-Sorb solution in glass vial. The measurement sample for C-14 was made by adding 10 mL of Permafluor to the C-14 fraction in glass vial. The purified H-3 and C-14 samples were measured by the liquid scintillation counter after quenching correction. The average recoveries of H-3 and C-14 with CRM were measured to be 96% and 85%, respectively. The sequential separation method for H-3 and C-14 investigated in this study was applied to activated charcoal filter produced from nuclear power plants after validating the reliability by result of proficiency test (KOLAS-KRISS, PT-2021-51).
        5.
        2021.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recently, the demand for atypical structures with functions and sculptural beauty is increasing in the construction industry. Existing mold-based structure production methods have many advantages, but building complex atypical structures represents limitations due to the cost and technical characteristics. Production methods using molding are suitable for mass production systems, but production cost, construction period, construction cost, and environmental pollution can occur in small quantity batch production. The recent trend in the construction industry calls for new construction methods of customized small quantity batch production methods that can produce various types of sophisticated structures. In addition to the economic effects of developing related technologies of 3D Concrete Printers (3DCP), it can enhance national image through the image of future technology, the international status of the construction civil engineering industry, self-reliance, and technology export. Until now, 3DCP technology has been carried out in producing and utilizing residential houses, structures, etc., on land or manufacturing on land and installing them underwater. The final purpose of this research project is to produce marine structures by directly printing various marine structures underwater with 3DCP equipment. Compared to current underwater structure construction techniques, constructing structures directly underwater using 3DCP equipment has the following advantages: 1) cost reduction effects: 2) reduction of construct time, 3) ease of manufacturing amorphous underwater structures, 4) disaster prevention effects. The core element technology of the 3DCP equipment is to extrude the transferred composite materials at a constant quantitative speed and control the printing flow of the materials smoothly while printing the output. In this study, the extruding module of the 3DCP equipment operates underwater while developing an extruding module that can control the printing flow of the material while extruding it at a constant quantitative speed and minimizing the external force that can occur during underwater printing. The research on the development of 3DCP equipment for printing concrete structures underwater and the preliminary experiment of printing concrete structures using high viscosity low-flow concrete composite materials is explained.
        4,300원
        8.
        2020.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Rhodomonas salina is a phototrophic marine flagellate. We examined the ultrastructure of R. salina with particular attention to the flagellar apparatus by transmission electron microscopy and compared it with that of other cryptomonads reported previously. The major components of the flagellar apparatus in R. salina were a keeled rhizostyle (Rhs), a striated fibrous root (SR), a SR-associated microtubular root (SRm), a mitochondrion-associated lamella (ML), and three types of microtubular roots (9r, 4r, and 2r). The keeled Rhs originated near the proximal end of the dorsal basal body, passed near the nucleus and dissociated at the posterior end of the cell. The SR and SRm originated between two basal bodies and laterally extended to the right side of the cell. The ML originated between two basal bodies and extended to the left side of the cell. The 9r originated between the ventral basal body and the Rhs and extended toward the anterior dorsal lobe of the cell. The 4r originated near the 9r and extended toward the dorsal lobe with the 2r, which originated between two basal bodies. Here, the flagellar apparatus in R. salina is described, and the ultrastructure of the flagellar apparatus is compared among cryptomonad species.
        4,200원
        11.
        2018.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        I have tried to make electronic listening and analyzing appratus, which were used for temporomandibular disorder patient’s. It can be heard T.M.J.D’s sounds. Normal person heard 20~20,000 Hz sound. Electronic appratus can capture furthermore. Electronic appratus composed of stethoscope rubber tube,small microphone, amplifier, telemetry, oscilloscope and speaker. The aim of oscilloscope and speaker are seen and heard T.M.J. sounds both dentists and patients.In developing countries, they use electronic stethoscope for diagnosis of heart sound and use for tele diagnosis. In my nation, laws of food and drugs were very rigid, so many researcher’s developed electronic stethoscope, but they could not produce it because of law. I suggest that soften the rigid law, and many new product will be produced. The apparatus that I developed was operated quite well both wired and wireless. It is suggested that we must develop new apparatus for T.M.D. patients and Telemedicine.
        4,000원
        13.
        2017.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Shape optimization is needed to enhance the performance or efficiency of many industrial products, for instance, such as small-scale electric parts, automotive design and so on. In, especially, small-scale apparatus with heat transfer, it is not easy to decide optimal shape of apparatus. Therefore, the shape of power auxiliary apparatus in automotive engine was investigated using numerical analysis which includes k- model and unsteady state. The relations between temperature and heat transfer were simulated in case of 3 Type and 3 Point for power auxiliary apparatus. As the results, the heat transfer was decreased due to flow recirculation in case of Type-1. Further high temperature did not always mean high heat transfer when the shape interacted with surrounding fluid.
        4,000원
        14.
        2017.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, factors analysis is performed for reducing friction in elevation motion of a large television stand over 50 inch. The first study is for specification decision and volume compensation experiment as an apparatus for compensating of the volume of the cylinder is compressed as the volume of piston rod. The second study is for optimized piston structure development by comparison pipe orifice and labyrinth orifice. Consequently, the result of total consideration in stability problem and performance of volume compensation for specification decision and volume compensation experiment is determined the final speculation of hollow rod ∅8 x ∅4 and riveting system. and the labyrinth orifice is not founded that of the Ø0.4~0.6 orifice both tests on 300 mm intervals.
        4,000원
        16.
        2017.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, The first study attempted to reduce the frictional force the gas seal lip technology. The second study is for specification decision and volume compensation experiment as an apparatus for compensating of the volume of the cylinder is compressed as the volume of piston rod. Consequently, in the gas seal lip technology, the outer-in diameter of ∅20 x ∅8 in the test result of hollow rod is revealed more proper if the weight of 50 inch television assumed as 30 kg. and the result of total consideration in stability problem and performance of volume compensation for specification decision and volume compensation experiment is determined the final speculation of hollow rod ∅8 x ∅4 and riveting system. The spring constant(K) showed an excellent value above the target value of 0.01 to 0.015 N/mm.
        4,000원
        17.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Numerical analysis using k-ε model of unsteady state was performed to decide the optimal shape of power auxiliary apparatus in automotive engine. In order to obtain auxiliary electric power using coolant in automotive engine, shapes of 3 Types were compared. Furthermore to achieve the confidence of numerical analysis, the results of numerical analysis was compared with those of experiment. As the results, it showed that accuracy of numerical analysis was about 85~98%. Further the optimal shape, in this study, was Type-1, which had outer rounding R32.5, among 3 Types.
        4,000원
        18.
        2016.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, factors analysis is performed for reducing friction in elevation motion of a large television stand over 50-inch. The first is a pipe type cross-section control for accurate position control of the piston rod. Here it was compared with the pipe type and labyrinth type orifice cross-section. The second study is for specification decision and volume compensation experiment as an apparatus for compensating of the volume of the cylinder is compressed as the volume of piston rod. Consequently, in the orifice cross section study between pipe type and labyrinth type through CAE and experimental consideration, cross section of labyrinth type orifice is preferred for reducing of friction. The result of total consideration in stability problem and performance of volume compensation for specification decision and volume compensation experiment is determined the final speculation of hollow rod φ8×φ4 and riveting system.
        4,000원
        19.
        2016.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Manual process of the workpiece into the environment with a pleasant to complement the disadvantages of increasing the efficiency of an automatic production process, and to develop the results were obtained as follows. automatic curl the average 2.99 rotation in the machine curling turns have been identified a failure of the product Is about 0.417% to have been identified. per minute of the machine producing the number of the product has been confirmed to 5.114 average. automatic curl a result, the production rate is two times of the machine.
        4,000원
        20.
        2016.05 구독 인증기관·개인회원 무료
        본 연구에서는 경상대학교가 보유한 기기를 이용하여 고분자 분리막의 특성 평가를 진행하였으며, 다양한 기기를 이용해 분리막의 특성을 평가하였다. 분리 막의 표면 개질 정도와 막의 fouling에 대한 정보를 얻기 위해 zeta potential 측정기를 이용하였고, BET 비표면적 측정기를 이용해 막의 비표면적 및 기공크 기 분포를 측정하였다. 또한 Time-lag 장비를 이용해 특정 기체에 대한 분리막 의 solubility와 diffusivity를 측정하였으며, 산소투과도 측정기(OTR)과 수분투습 도 측정기(WVTR)를 이용해 일정시간 동안 막을 통과하는 산소와 수증기의 양을 측정하였다.
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