• Journal of Energy Engineering
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• v.9 no.1
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• pp.54-59
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• 2000

전자부품 및 시스템의 고속/고밀도화 추세에 따라 발열밀도가 계속증가하고 있다. 최근 팬티엄 II 급이상의 노트북 컴퓨터의 CPU에서는 칩당 발열량이 10W 이상으로 증가하고 있고 패키징 공간의 제한 때문에 소형히트파이프를 이용한 냉각이 많이 적용되고 있다. 본 연구에서는 모세압구동력이 크고 생산성등이 고려된 편조 형태의 새로운 윅을 개발하였으며 , 노트북 컴퓨터의 CPU 등 소형 전자부품냉ㄱ가에 적용가능한 직경 3, 4 mm 히트파이프를 설계 및 제작하였다. 직경 3, 4 mm Miniature Heat Pipe (이하 MHP) 의 작동특성은 일반적인 중형히트파이프와 다르므로 MHP 의 열전달 특성 및 작동성능에 미치는 각종 인자들의 영향을 파악하고자 성능시험을 수행하였다. 고려된 작동인자로는 작동유체 충전률, 전체 파이프길이 및 증발부, 응축부길이, 설치 경사각, 윅의 가닥수, 열부하 등이다. 작동인자의 영향과 관련된 연구결과는 향후 패키징을 위한 응용연구의 기초자료로 활용할 수 있을 것이다.

• Proceedings of the KIEE Conference
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• 2001.04a
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• pp.480-484
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• 2001

본 연구에서는 실제 풍력 자원 측정용 Pole에 설치된 풍속계가 mast에 의한 후류와 풍속계 설치시 기울어짐에 의해 풍속 data가 어떠한 영향을 받는가에 대하여 고찰하였다. 먼저 mast은 직경 4", 6" Pipe에 대하여 각각 실험하였고, 측정 mast의 방위각은 풍속에 평행한 방향을 $0^{\circ}$ 로 정하고 측정 mast 중심으로부터 $0^{\circ}{\sim}20^{\circ}$ 까지 $5^{\circ}$ 간격으로 측정하였다. 이 연구를 통해 실제 일정 두께를 갖는 mast에 설치되어 있는 풍속계에서의 풍속이 풍향에 대한 boom의 위치와 기울어짐에 따라 영향이 있음을 확인할 수 있었고, mast의 직경에 대한 영향도 크게 있음을 확인할 수 있었다. 따라서, 본 연구의 결과를 이용하여 향후의 풍력자원 자료 측정설비의 설치상의 정확도 검증이나 혹은 측정된 자료의 보정등에도 광범위하게 이용될 수 있을 것이다.

• Microbiology and Biotechnology Letters
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• v.18 no.1
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• pp.71-75
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• 1990

Yoghurt was prepared with Bifidobacterium longum TK-100 and Lactobacillus acidophilus TK-2070. The prepared yoghurt showed the increase of the titratable acidity under cold storage condition. This was derived from the active L. acidophilus TK-2070 on the logarithmic phase rather than from the B. longumn TK-2070. B. longum TK-100 grew well in the facultative anaerobic condition as well as in the strict anaerobic condition. Reinforced clostridial agar medium with 0.1% aniline blue was tried for the differential viable cell counts in the mixed culture and in the yoghurt. B. longurn TK-2070 had the light gray, blue-dotted colonies of about 2 mm diameter. L. acidophilus TK-2070 had the light gray colonies of about 1 mm diameter.

• Clinical and Experimental Pediatrics
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• v.50 no.10
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• pp.976-981
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• 2007

Purpose : Aortic valve or aortic root (AoRo) replacement is occasionally required because of AoRo dilatation and aortic regurgitation (AR) in repaired tetralogy of Fallot (TOF). We evaluated AoRo size and possible factors associated with its hemodynamic nature in patients with repaired TOF. Methods : We investigated 130 repaired TOF patients more than 15 years of age who followed-up by echocardiography from January 2002 to December 2003. Of 130 patients, we identified 17 patients with AoRo dilatation, which was defined as ratio of expected AoRo size by standard nomogram (AoRo ratio) >1.5 (dilator group), and 113 TOF controls, with AoRo ratio <1.5 (non-dilator group). Results : Mean indexed AoRo size ($mm/m^2$) in the first echo was $24{\pm}3.2$ in the dilator group and $18{\pm}3.4$ in the non-dilator group (P<0.0001). AoRo rate of change (mm/year) from the first to latest echo study was $1.6{\pm}3.8$ in dilator group and $0.05{\pm}1.6$ in the non dilator group (P=0.0021). Patients from the dilator group showed a higher prevalence of pulmonary atresia (P=0.031) and a history of aortopulmonary shunt before repair (P=0.048), moderate to severe AR (P=0.0065), and increased left ventricular end-diastolic dimensions (P=0.003). Conclusions : A subset of patients late after TOF repair may show progressive dilatation of AoRo. To identify and prevent long-term sequelae in this patient group, regular follow-up and speculation about AoRo after TOF repair is recommended.

• Horticultural Science & Technology
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• v.28 no.6
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• pp.964-972
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• 2010

Objective of this research was to determine the influence of physico.chemical properties of root substrates on growth of daughter plants that were developed through plastic bag cultivation of mother plants in 'Seolhyang' strawberry propagation. Six different formulations of root substrates for daughter plant cultivation were peatmoss + vermiculite (5:5, A), peatmoss + perlite (7:3, B), coir dust + perlite (7:3, C), coir dust + peatmoss + perlite (3.5:3.5:3.0, D), rice-hull + coir dust + perlite (2:7:1, E), and rice hull + coir dust (3:7, F). The 10 cm plastic pots filled with formulated substrates were located near the plastic bag where mother plants were growing. Then the runners and daughter plants originated from mother plants were fixed on each root substrate filled into 10 cm plastic pot and daughter plants were grown in the plastic pots. The container capacity and air space showed big differences among substrates tested. The substrates E and F had the less container capacity and the higher air space than other substrates tested. This indicates that the two substrates would have difficulties in water managements during the raising of daughter plants. The substrates of A, B, and D which contained peatmoss in formulation had higher nitrogen concentrations than those containing coir dust or rice hull. The substrates of E and F which contained rice hull had lower nitrogen, phosphorus and potassium concentrations than those that contained coir. The crown diameters of daughter plants grown in substrate A were around 13 mm which is thicker than those grown in other substrates. The fresh weights of daughter plants grown in A substrate were the heaviest followed by C, F, D, E, and B. The dry weight of daughter plants showed similar tendency to those of fresh weight. The daughter plants which had heavy fresh and dry weights and thick crown diameter are considered good seedlings. Based on this justification, the substrates of A, C and F are acceptable for daughter plant growth of 'Seolhyang' strawberry.

• Journal of the Korean earth science society
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• v.45 no.2
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• pp.136-146
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• 2024

This paper introduces the seismic facies classification and mapping of igneous bodies found in the sedimentary sequences of the Yellow Sea shelf area of Korea. In the research area, six extrusive and three intrusive types of igneous bodies were found in the Late Cretaceous, Eocene, Early Miocene, and Quaternary sedimentary sequences of the northeastern, southwestern and southeastern sags of the Gunsan Basin. Extrusive igneous bodies include the following six facies: (1) monogenetic volcano (E.mono) showing cone-shape external geometry with height less than 200 m, which may have originated from a single monogenetic eruption; (2) complex volcano (E.comp) marked by clustered monogenetic cones with height less than 500 m; (3) stratovolcano (E.strato) referring to internally stratified lofty volcanic edifices with height greater than 1 km and diameter more than 15 km; (4) fissure volcanics (E.fissure) marked by high-amplitude and discontinuous reflectors in association with normal faults that cut the acoustic basement; (5) maar-diatreme (E.maar) referring to gentle-sloped low-profile volcanic edifices with less than 2 km-wide vent-shape zones inside; and (6) hydrothermal vents (E.vent) marked by upright pipe-shape or funnel-shape structures disturbing sedimentary sequence with diameter less than 2 km. Intrusive igneous bodies include the following three facies: (1) dike and sill (I.dike/sill) showing variable horizontal, step-wise, or saucer-shaped intrusive geometries; (2) stock (I.stock) marked by pillar- or horn-shaped bodies with a kilometer-wide intrusion diameter; and (3) batholith and laccoliths (I.batho/lac) which refer to gigantic intrusive bodies that broadly deformed the overlying sedimentary sequence.

• Journal of Korean Society of Steel Construction
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• v.28 no.1
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• pp.53-64
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• 2016

The double split tee connection, a type of beam-to-column moment connection, exhibits different behavioral characteristics according to changes in the thickness of the T-stub flange, the gauge distance of the high-strength bolt, and the number and diameter of high-strength bolts. In general, the double split tee connection is idealized and designed so that a T-stub fastened to the top and bottom supports a flexural moment, and a shear tab supports a shear force. However, if the double split tee connection is applied to low-and medium-rise steel structures, the size of the beam member becomes small, and thus the shear tab cannot be bolted to the web of a beam. In this regard, this study was conducted to propose connection details to ensure that the double split tee connection with a geometric shape can display sufficient shear resisting capacity. To this end, experiments were conducted using full-scale specimens for the double split tee connection.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.26 no.2
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• pp.118-124
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• 1990

The rope winder in addition to the line hauler was used for recoiling of the main line to the rope pond at the stern, however, catching the loops, evenly revoiling and arrangements of the loops were done manually by two men. The automatic loop catcher under the rope winder was consisted with the rotary lever, semicircle guide plates, transfer belt and swing rope receiver for arrangements of the loops and evenly recoiling. The obtained results are as follows: 1. The minor diameter of a loop and the diameter of the coiling pile in a lead core PP rope(ø 10mm) are about 14cm and 60cm while the rope is piled on the bottom. 2. Distribution ratio of the loops within upper or lower 10cm from the transfer belt is 93% with a lead sinker and 98% without sinker using by the smaller loop catcher. 3. The relationship between revolutions of the rotary lever N sub(1) (rpm) and the hauling pulley N sub(p) (rpm) by gear ratio 3:1 in the smaller loop catcher is as follows: N sub(p) =2.86 N sub(1) +23.74 and optimum ratio of horizontal speed of the loops by the rotary lever to hauling speed is about 70%. 4. The rope receiver is swung front and rear for the evenly recoiling and its period can be controlled by gear ratio or hydraulic circuit in accordance with the interval of the loops.

• Science of Emotion and Sensibility
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• v.21 no.2
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• pp.137-144
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• 2018

The study figured out the operational conditions of a two-way movement actuator made of one-way shape memory alloy (OWSMA) for versatile ventilation intelligent garments. To develop a low-power actuator that consumes energy only when a garment changes its form such as opening and closing, multiple channels of OWSMA were used, and optimum diameter of the wires was examined. For the switch device, optimum voltage application unit time was determined. Optimum diameter of OWSMA wire was determined by applying 3.7V to the pre-determined candidate diameters, which demonstrated two-way operation in previous studies. In order to evaluate the optimum voltage application time, the internal diameter of the actuator was measured while increasing and decreasing by 50 ms from the unit time of voltage application. Delay time under two-way operation of the actuator was measured to minimize interference caused by heat between channels. Power of 3.7V was applied to OWSMA for assessment of optimal time, and the whole process from heating to cooling was video-recorded with a thermal image camera to determine the point of time at which the temperature of OWSMA wire dropped below the phase transformation temperature. The results showed that $0.4{\Phi}$ was the most suitable diameter, and the optimum unit time of voltage applied to open and close the actuator was 4100ms. It was also shown that the delay time should be more than 1.8 seconds between two-way operations of the actuator.

• Clean Technology
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• v.16 no.3
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• pp.213-219
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• 2010

Vortex tube is the device that can separate small particles from the compressed gas, as well as compressed gas into hot and cold gas. Due to energy and particle separation ability, a vortex tube can be used as the main component of the $CO_2$ absorption device. In this study, experimental approach has been performed to analyze the energy separation characteristics of the vortex tube. To obtain the preliminary design data, energy separation characteristics of the vortex tube has been tested for orifice diameter, nozzle area ratio, and tube length. As a result, the orifice diameter is the major factor of the vortex tube design. The nozzle area ratio and tube length have a minor effect on the energy separation performance. For Dc=0.6D, AR=0.14~0.16, and L=16D, maximum energy separation has been occurred. The result from this study can be used as the basic design data of the $100Nm^3$/hr class vortex tube applied to the $CO_2$ absorption device. Compared with the $CO_2$ absorption process containing an absorption tower, the process with a vortex tube is expected to have a huge advantage of saving the installation space and the operating cost.