• Solar Energy
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• v.18 no.3
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• pp.217-228
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• 1998

The purpose of this research is to investigate the characteristics of static and total pressure distribution in the upward free water jet system impinged on a downward flat plate. The rectangular nozzle was used and its contraction and aspect ratio was five and about seven respectively. Experimental conditions considered were jet velocity, distance between nozzle and flat plate, height of supplementary water. It was founded that pressure distribution on the flat plate had the Gaussian curve when the pressure at stagnation point and impinging half width were chosen as the scaling parameters. The maximum pressure was shown at the stagnation point. The central impingement velocity decreased with the increment of distance between nozzle and flat plate, and its slop of decay was similar to that of chracteristics decay region in the three-dimensional free jet.

• Solar Energy
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• v.16 no.2
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• pp.65-77
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• 1996

The operating thermal chracteristics of direct contact liquid-ice heat exchanger was experimentally investigated. In this paper, The effects of Ice Packing Factor(IPF), the inlet temperature and the flow rate of Heat Transfer Fluid(HTF) were stuided in the liquid-ice heat exchanger. Thermal stratification in liquid-ice heat exchanger was established clearly and faster at the higher inlet temperature and flow rate of HTF. At the end of melting of the lower flow rate is cleared the thermal stratification in liquid-ice heat exchanger. The temperature stratification is long with higher value of IPF of liquid-ice heat exchanger. The mean temperature of liquid-ice storage was changed rapidly with increasing flow rate and inlet temperature of HTF. The gradiant of ratio of total energy to latent energy was found higher with increasing inlet temperature and flow rate.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.4
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• pp.591-595
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• 1998

Browning chracteristics were investigated for Chicory roots(Cichorium intybus L.) when roasted at different conditions of 120 to $180^{\circ}C$ in temperature and 10 to 40min in time. The soluble solid of water extracts obtained from roasted Chicory roots increased slowly with increasing roasting temperature and time, but it decreased above $160^{\circ}C$. The contents of reducing sugar and amino-type nitrogen in aqueous extracts obtained from roasted Chicory roots decreased rapidly with increasing the roasting time and temperature. Browning color intensity in aqueous extracts of roasted Chicory roots increased with increasing the roasting temperature and time, Hunter's color L and b values of Chicory powder decreased with increasing the roasting temperature and time, while Hunter's color a and ${\Delta}E$ values continuously increased with increasing the roasting temperature and time.

• Journal of the Korea Concrete Institute
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• v.17 no.6 s.90
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• pp.911-922
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• 2005

A theoretical study was performed to investigate the behavioral chracteristics and shear strength of fiber reinforced concrete slender beams. In the fiber reinforced concrete beam, the shear force applied to a cross section of the beam was resisted by both compressive zone and tensile zone. The shear capacity of the compressive zone was defined addressing the interaction with the normal stresses developed by the flexural moment in the cross section. The shear capacity of the tensile zone was defined addressing the post-cracking tensile strength of fiber reinforced concrete. Since the magnitude and distribution of the normal stresses vary according to the flexural deformation of the beam, the shear capacity of the beam was defined as a function of the flexural deformation of the beam. The shear strength of the beam and the location of the critical section were determined at the intersection between the shear capacity and shear demand curves. The proposed method was developed as a unified shear design method which is applicable to conventional reinforced concrete as well as fiber reinforced concrete.

• Applied Biological Chemistry
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• v.35 no.5
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• pp.361-366
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• 1992

The antagonistic bacteria, showing distinguished effect against Fusarium oxysporum and Rhizoctonia solani were isolated from the rhizosphares of horticultural plants and identified as Bacillus subtilis. The strains were studied for their chracteristics of biochemistry, physiology, antagonistic effect against plant pathogenic fungi, and growth promoting effect on horticultural plants. The Bacillus thuringiensis(BT) HD-1 toxin gene was introduced into these B. subtilis. The BT toxin genes on chromosome of the bacteria were identified by southern blotting, but its proteins were not detected by SDS-PAGE. These transformed bacteria showed growth promoting effect and showed also insecticidal and antagonistic effects against Bombix mori and fungi F. oxysporum and R. solani but not against nematode Bursaphelenchus xylophilus.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.2
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• pp.401-406
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• 2015

The change of subthreshold swing for channel length of asymmetric double gate(DG) MOSFET has been analyzed. The subthreshold swing is the important factor to determine digital chracteristics of transistor and is degraded with reduction of channel. The subthreshold swing for channel length of the DGMOSFET developed to solve this problem is investigated for channel thickness, oxide thickness, top and bottom gate voltage and doping concentration. Especially the subthreshold swing for asymmetric DGMOSFET to be able to be fabricated with different top and bottom gate structure is investigated in detail for bottom gate voltage and bottom oxide thickness. To obtain the analytical subthreshold swing, the analytical potential distribution is derived from Possion's equation, and Gaussian distribution function is used as doping profile. As a result, subthreshold swing is sensitively changed according to top and bottom gate voltage, channel doping concentration and channel dimension.

• Korean Journal of Ecology and Environment
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• v.35 no.3 s.99
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• pp.181-186
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• 2002

To evaluate the eutrophication status of the Asan Reservoir in Korea, physicochemical parameters were analyzed for samples of 19 sampling stations collected in the period from March to November in 1997. Water temperature was in the range of $8.3{\sim}35.3{\circ}^C$, with thermocline appearing in summer. Dissolved oxygen also showed similar verticle variation to temperature. Secchi depth was very shallow with a range of 0.1~1m. Suspended solids ranged from 11.3 mg/1 to 2143.3 mg/1, and seemed to be affected by the amount of rainfall and the standing stocks of phytoplankton. Nutrient concentrations were higher in tributaries, and decreased with downflow. Nutrients were low in the summer and early autumn when algal blooms occur, and high in the early spring and winter. The Trophic State Index showed that the Asan Reservoir is in a hypertrophic condition．

• Journal of Sericultural and Entomological Science
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• v.43 no.2
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• pp.99-103
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• 2001

Daeseongppong, Daebungppong, Daeokppong were bred, and Shingwangppong was selected among the recommended mulberry varieties of the grown silkworm, in order to meet the increasing the interest about the mulberry fruit, The major characteristics of the mulberry fruits were also studies. The chromosome number of Daeseongppong, Daebungppong and Daeokppong are 2n=56 recognized autotetraploid, and that of Shingwangppong is 2n=42 as a triploid. Seed forming rate of Daeseongppong, Daebungppong, and Daeokppong are more than 58%, but that of the Shingwangppong is very low with 6.7%. Concerning the single fruit weight, Daeseongppong is 4.05g, Daeokppong 3.38g, Daebungppong 2.99g which belonged to big fruit group. However Shingwangppong is medium as 2.28g. The sugar contents of Shingwangppong, Daeokppong, Daebungppong, Daeseongppong are 14.8%,13.7%,13.1% and 12.7% respectively. The sugar/acidity rate of them are above 21. The fruit maturity of Shingwangppong is early, those of Daebungppong, Daeokppong are medium and that of Daeseongppong is late. Yielding Potentiality of Daebungppong is high, those of Daeseongppong, Shingwangppong are comparatively high, and that of Daeokppong is moderate. In the case of cold hardiness, those of Shingwangppong, Daeokppong, Daebungppong are comparatively good, that of Daeseongppong is weak slightly.

• Journal of the Korean Solar Energy Society
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• v.39 no.3
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• pp.9-17
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• 2019

Laser cutting cell of solar cells can achieve high voltage and efficiency through more array than conventional 6 inch cell compared to same area. In this study, we fabricated c-Si cutting cell with various lasers and laser conditions such as power, speed, and number of times. In the case of picosecond laser, excellent surface characteristics were obtained due to small surface defects and low thermal damage at the output of 20W and the speed of 100 mm/s. However, it is not possible to fabricate a cutting cell having good characteristics due to nonuniform cutting inside the wafer when the processing for forming a cutting cell is not sufficiently performed. For nanosecond lasers, the best wafer characteristics were obtained for fabrication of excellent cutting cells at a frequency of 500 kHz and a laser speed of 100 mm/s. However, the nanosecond laser has not been processed sufficiently in the condition of a number of times. As a result, it was confirmed that the wafer thickness was cut by $63{\mu}m$ of the cell thickness of $170{\mu}m$ in the condition of five times of laser process. It was found that more than 30% of the wafer thickness had to be processed to fabricate the cutting cell. After cutting the 6-inch cell having the voltage of 0.65 V, we obtained the voltage of about 0.63 V.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2021.04a
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• pp.26-26
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• 2021

메밀(Fagopyrum esculentum Moench)은 마디풀과(Polygonaceae) 메밀속 (Fagopyrum)으로 약 20종이 있으며, 전 세계 인류 역사와 함께해 왔으며, 오랫동안 사랑을 받아 온 작물이다. 메밀 생태형 분류는 늦게 파종할수록 종실 수량이 떨어지는 여름메밀, 반대로 늦게 파종할수록 종실 수량이 증가하는 가을메밀과 중간형 메밀이 있다. 여름메밀 대표품종은 양절메밀, 양절메밀2호가 있다. '양절메밀'은 춘파·하파 재배가 가능한 여름메밀 품종으로, 1994년 육성되어 장려 품종으로 결정되었다. '양절메밀'의 특성은 유한생육 초형으로, 조숙·단간·다수성 이며, 꽃색은 흰색이며 종자는 흑색이다. 성숙일수는 60-64일로 짧으며, 성숙 후에도 탈립이 강하고, 경장은 단간으로, 도복에 강한 편이다. 그 후 수량성이 증가된 '양절메밀 2호'가 육성되었다. 양절메밀2호는 대립종자로 종자가 흑갈색이며 천립중도 29.5g으로 양절메밀보다 무겁다. 가을메밀로는 대산메밀, 다원 및 순백이 육성되었다. 싹용인 '대산메밀'은 줄기가 연홍색이고 종자가 갈색이었다. '대산메밀'은 가을메밀 품종으로 가을 재배에 적합하다. 경장은 중장간종이며, 생육 일수는 양절메밀보다 약간 늦은 중생종이다. 메밀싹 수율이 높아 새싹 재배에 적합한 것으로 나타났다.