• 태양에너지
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• 제18권3호
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• pp.95-105
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• 1998

In this study, basic design data which were required for development of highly efficient ice storage system with low temperature latent heat were experimentally obtained. The ice storage system considered in this study was the one that has been widly used in the developed country and called the ice-on-coil type. Using the system, the ice storage performance for various design parameters which were the flow direction and the inlet temperature of the secondary fluid was tested. In addition, the timewise variation of the interface profiles between the solid and the liquid were visualized, and the heat transfer characteristics of the Phase Change Material(PCM) in the ice storage tank were Investigated. During the freezing processes in the ice storage tank with several vertical tubes, decrease of the heat transfer area and the heat resistance of the ice layer made the increasing rate of ice packing factor(IPF) less. The total freezing energy for the upward flow of the secondary fluid was higher than that for the downward flow. The average ice storage efficiency for the upward flow of the secondary fluid was higher than that for the downward flow.

• 설비공학논문집
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• 제16권2호
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• pp.142-149
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• 2004

Recently, the government introduced the thermal storage system for reducing the electric power load. Especially, the ice slurry type has gained lots of interest due to its good heat transfer and flowing characteristics. This study was peformed to understand the effects of transporting ice slurry through elbows of various angle. Propylene glycol water solution was used and about 2 mm ice particles were circulated. The experiments were carried out under various conditions, such as concentration and velocity of water solution ranging between 0∼20 wt％, 1.5∼2.5 m/s, respectively. And elbows with 4 different angles of 30$^{\circ}$, 45$^{\circ}$, 90$^{\circ}$, 180$^{\circ}$. The differential pressure and IPF (ice packing factor) between the pipe entry and exit were measured. The tendency of pressure loss and outlet IPF in elbow is that the pressure loss was reduced as concentration and flow velocity of water solution is increased, and low value appeared at 10 wt％ and 2.5 m/s. The variation of outlet IPF was compared with the inlet IPF in the range of $\pm$20％.

• 한국식품저장유통학회지
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• 제1권2호
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• pp.81-86
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• 1994

This study examined the quality change of red peppers during storage at various temperatures and humidities. It was observed that red peppers showed mold at aw 0.75(>25% water content), discoloration at aw 0.33(<10%) and browning at aw 0.75(>19%). The most ideal condition of the storage for red peppers was a 13∼15% water content and 60${\pm}$5% RH. The storage life for whole red peppers were 2.0 months at 40$^{\circ}C$, 13.6 months at 25$^{\circ}C$, 27.3 months at 15$^{\circ}C$, 30.0 months at 10$^{\circ}C$, and 65.0 months at -3$^{\circ}C$. During any storage period above, level of capsanthin, browning and capsaicin were changed for whole peppers. Browning appeared to be a crucial factor for marketable quality of stored red peppers. It was found that the level of capsaicin & capsanthin have a miner relationship with marketable quality for consumer. Storing red peppers in nitrogen and vacuum atmosphere packing condition was found to be better than storing them in air at various temperatures in terms of storage life and quality maintenance. The nitrogen gas packaged red peppers kept longer shelf life and better quality compared with vacuum packaging.

• KSBB Journal
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• 제17권1호
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• pp.14-19
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• 2002

본 연구의 목적은 회전생물반응기에 고정화한 P. chrysosporium IFO 31249를 이용하여 LiP 생산의 최적 조건을 조사하는 것이다. 회전생물반응기에서 batch culture시 최대 LiP 활성도는 300 U/L이었다. LiP 생산의 최적 조건은 드림의 회전 속도는 1 rpm, 담체 충진율은 20%이었다. MnP 생산을 위한 $MnSO_4$$\cdot$$H_2O$ 의 최적 농도는 50 ppm이었다. 그리고 산소의 충분한 공급은 LiP 생산의 가장 중요한 인자이었다. 또한 LiP 및 MnP의 생산에 있어 repeated-batch culture가 3번이나 가능하였다.

• 한국결정학회지
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• 제8권2호
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• pp.144-148
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• 1997

단결정 X-ray 회절법을 이용하여 Bentazone, C10H12N2O3S의 결정 및 부자구조를 규명하였다. 공간군은 P21/c이며 a=9.7818(9)Å, b=9.6095(9)Å, c=13.5737(9)Å, β=97.269(1)', Z=4, V=1136.1(6) Å. 직접법으로 개략적인 분자모델을 설정하고, 1396(Fo2>4σFo2)개의 독립 회절반점에 완전행력 최소자승법으로 정밀화하여 최종신뢰도값, R=0.045인 최종적인 분자모형을 구하였다. 분자내의 Thiocarbazin ring과 Isopropyl작용기는 staggered conformation을 이루고 있으며, 수소결합에 의하여 결합된 분자들은 c-축 방향으로 교차 하면서 packing 되어 있다.

• 한국공작기계학회논문집
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• 제17권2호
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• pp.110-113
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• 2008

Embedded capacitor technology is one of the effective packing technologies for further miniaturization and higher performance of electric packaging system. In this paper, the embedded capacitors were simulated and fabricated in 8-layered printed circuit board employing standard PCB processes. The composites of barium titanante($BaTiO_3$) powder and epoxy resin were employed for the dielectric materials in embedded capacitors. Theoretical considerations regarding the embedded capacitors have been paid to understand the frequency dependent impedance behavior. Frequency dependent impedance of simulated and fabricated embedded capacitors was investigated. Fabricated embedded capacitors have lower self resonance frequency values than that of the simulated embedded capacitors due to the increased parasitic inductance values. Frequency dependent capacitances of fabricated embedded capacitors were well matched with those of simulated embedded capacitors from the 100MHz to 10GHz range. Quality factor of 20 was observed and simulated at 2GHz range in the 10 pF embedded capacitors. Temperature dependent capacitance of fabricated embedded capacitors was presented.

• 설비공학논문집
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• 제20권12호
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• pp.825-832
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• 2008

The ice slurry maker which can produce the ice slurry well for the ice particle in-flowing condition was revised. We removed the stagnant region at the top of the ice slurry maker, and IPF 40% could be realized. The IPF controller with 6 mm diameter holes at the bottom was designed. But the IPF controller with only 6 mm diameter holes could not control IPF in a pipe. This is because the ice particles at ice slurry flow exist homogeneously not only at the upper part but also at the bottom part. We changed the hole size of IPF controller surface using fine meshes and then, IPF in a pipe was increased by 70% when the hole size was $80{\mu}m$ and less.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
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• pp.181-184
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• 2004

Organic semiconductors have attracted considerable attention due to their interesting physical properties followed by various technological applications in the area of electronics and opto-electronics. It has been a long time since organic solar cells were expected as a low-cost high-energy conversion device. Although practical use of them has not been achieved, technological progress continues. Morphology of the materials, organic/inorganic interface, metal cathodes, molecular packing and structural properties of the donor and acceptor layers are essential for photovoltaic response. We have fabricated solar-cell devices based on copper-phthalocyanine(CuPc) as a donor(D) and fullerene($C_{60}$) as an electron acceptor(A) with doped charge transport layers, and BCP as an exciton blocking layer(EBL). We have measured photovoltaic characteristics of the solar-cell devices using the xenon lamp as a light source.

• Current Photovoltaic Research
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• 제9권2호
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• pp.31-35
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• 2021

Shingled module shows high ratio active area per total area due to more efficient packing without inactive space between cells. The module is fabricated by connecting the pre-cut cells into the string using electrically conductive adhesives (ECA). ECAs are used for electric and structural connections to fabricate the shingled modules. In this work, we investigated a correlation between ECA peel strength and the efficiency of pre-cut 5 cells module which are fabricated according to ECA interconnection conditions. The curing conditions are varied to determine whether ECA interconnection properties can affect module properties. As a result of the peel test, the highest peel strength was 1.27 N/mm in the condition of 170℃, the lowest peel strength was 0.89 N/mm in the condition of 130℃. The efficiency was almost constant regardless of the curing conditions at an average of 20%. However, the standard deviation of the fill factor increased as the adhesive strength decreased.

• Journal of Animal Science and Technology
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• 제65권2호
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• pp.427-440
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• 2023

The current study evaluated carbon dioxide (CO₂) emissions from beef and pork production and distribution chains in the South Korean meat industry. Data from industrial example farms and slaughterhouses were assessed on the basis of both the guidelines from the United Kingdom's Publicly Available Specification (PAS) 2050:2011 and the Korea Environmental Industry & Technology Institute carbon footprint calculation. The main factors for our estimations were animal feeds, manure waste, transportation, energy and water, refrigerants, and package data. Our analyses show that 16.55 kg CO₂ equivalent (eq) was emitted during the production of 1 kg of live cattle. When retail yields and packing processes were considered, the CO₂-eq of 1 kg of packaged Hanwoo beef was 27.86 kg. As for pigs, emissions from 1 kg of live pigs and packaged pork meat were 2.62 and 12.75 kg CO₂-eq, respectively. While we gathered data from only two farms and slaughterhouses and our findings can therefore not be extrapolated to all meats produced in the South Korean meat industry, they indicate that manure waste is the greatest factor affecting ultimate CO₂ emissions of packaged meats.