• Applied Biological Chemistry
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• v.26 no.1
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• pp.47-52
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• 1983

The size distribution and changes of volume and grain hardness of ‘Sedohadaka', waked barley of various polishing yields during hydration process at various temperatures were investigated, and were analyzed kinetically, Both major and minor diameter of barley grain decreased linearly during polishing, and the decreasing rate of major diameter was greater than that of minor diameter. The volume change of barley grain could be expressed as a power of hydration time, and a break point was found in case of non-polished barley. The changing rate of grain hardness followed the equation of a first-order reaction, and the reaction rate constant increased with decreasing polishing yields and at higher temperature in the range of $20{\sim}60^{\circ}C$. The activation energy of hardness change reaction of polished barley during hydration were ranged $5.1{\sim}7.8Kcal/mole$, and 13.3Kcal/mole of non-polished barley.

• Journal of Convergence for Information Technology
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• v.11 no.2
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• pp.117-123
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• 2021

The effects of electrolyte concentration on the electrochemical properties of Fe4[Fe(CN6)]3(FeHCF) as a novel active material for the electrode of aqueous zinc-ion batteries was investigated. The electrochemical reactions and structural stability of the FeHCF electrode were significantly affected by the electrolyte concentration. In the electrolyte solutions of 1.0-7.0 mol dm-3, the charge-discharge capacities increased with increasing electrolyte concentration, however gradually decreased as the cycle progressed. On the other hand, in the 9.0 mol dm-3 electrolyte solution, the initial capacity was relatively small, however showed good cyclability. Additionally, the FeHCF electrode after five cycles in the former electrolyte solutions, had a change in crystal structure, whereas there was no change in the latter electrolyte solution. This suggests that the performance of the FeHCF electrode is greatly influenced by the hydration structure of zinc ions present in electrolyte solutions.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2002.05a
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• pp.115-119
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• 2002

고분자 전해질 연료전지는 전해질로 고체고분자막을 사용하는 연료전지로 고분자막은 수소 이온의 활발한 전달을 위해 일정량의 수분이 존재해야 한다. 따라서 연료전지의 운전 중에 고분자막은 항상 수화되어 있어야 하며 수분이 부족하게 되면 수소이온 전도도가 떨어지고, 막의 수축으로 인해 전극과 막 계면의 저항이 증가한다. 반대로 수분이 많이 존재하면 촉매 표면에 반응기체의 확산이 어려워져 전지 성능이 감소하게 된다.(중략)

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.781-784
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• 2000

A combination of Poisson-Boltzman (PB) equation and quantum mechanics methodologies has been used for the calculation of the solvation energies and $pK_a$ values of biomolecules such as amino acids and nucleotide bases.

• Solar Energy
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• v.15 no.3
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• pp.29-38
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• 1995

The heat-storage characteristics accompanied by exothermic reaction at the regeneration of $Ca(OH)_2$ in tile heat-storage mode of a chemical heat pump system using a $Ca(OH)_2/CaO$ reversible thermochemical reaction was examined in a lab-scale unit. In this heat-storage mode, the particle bed of CaO could be regenerated by heating the $Ca(OH)_2$ packed bed to the higher temperature at which the equilibrium pressure in the reactor is greater than the water vapor pressure in the condenser. The results are i) the dehydration, thermal decomposition, rate of $Ca(OH)_2$ was higher at the lower part of particle bed than at the upper part, ii) in the reactor, the dehydration was proceeded along radial and axial direction, from inner part to the outer part, which explains heat transfers from the center to wall and from the tenter to lower or upper part of reactor.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.6
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• pp.1190-1194
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• 2000

과열 수증기 공정처리 효과가 현미의 수화 및 조직특성에 미치는 영향을 조사하기 위하여 현미(동진)를 과열수증기의 압력이 $1kg_{f}/$\textrm{cm}^2$$로 유지되는 상태에서 수증기의 온도를 127, 150, 16$0^{\circ}C$로 달리하면서 과열 수증기 처리를 하였다. 수분흡수속도는 수침온도(60~8$0^{\circ}C$)에 따라서 현미와 백미가 각각 0.03569~0.1049 $cm/min^{-1/2}$와 0.03474~0/1618 $cm/min^{-1/2}$의 범위를 보였다. 현미와 백미의 활성화에너지는 각각 6.98 및 9.59 cal/mole을 나타내어 열수화 특성이 다름을 보였다. 한편, 과열 수증기 처리현미의 경우 $65^{\circ}C$에서의 확산계수는 18.96$\times$$10^{-5}$$\textrm{cm}^2$/min)와 처리하지 않은 현미(22.28$\times$$10^{-5}$$\textrm{cm}^2$/min)의 중간 값을 나타내었다. 과열 수증기처리 후 현미의 표면조직은 균열이 발생하였는데, 수증기 온도가 높을수록 균열의 정도가 컸다. 이상과 같은 수증기 처리는 현미 강층의 구조를 변화시킬 뿐만 아니라, 내부 전분층의 부분적 균열에도 효과적으로 작용하는 결과를 보인 것으로 예측된다.

• Journal of the Korean Solar Energy Society
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• v.22 no.1
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• pp.9-21
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• 2002

To develope chemical heat pump using available energy sources, solar heat and other kinds of waste thermal energy, we have studied the heat transfer rate in cylindrical bed reactor packed with calcined Dolomite. Two dimensional (radial and circumferential) Partial differential equations, concerning heat and mass transfer in packed bed of calcined Dolomite, are solved numerically to describe the characteristics of the reaction of calcined Dolomite and heat transfer. The results obtained by numerical analysis about two dimensional profiles of temperature and conversion of reactant in the packed bed reactor and the amount of exothermic heat released from the reactor are follows. It was found that all of calcined Dolomite packed bed kept the reaction temperature of about 750K throughout the entire part of the bed, immediately after the steam was introduced exothermic reaction of hydration was proceeded from the packed bed inpu to output and from wall side to center. The rate of thermochemical reaction depends on the temperature and concentration and it is also governed by the boundary conditions and heat transfer rate in the particle packed bed.

• Transactions of the Korean hydrogen and new energy society
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• v.27 no.5
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• pp.540-546
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• 2016

Besides high-efficient photovoltaics based on silicon, polymers, dye-sensitization and hybrid perovskite materials, biomimetic solar cells inspired by a leaf in nature has also been actively studied. As one example, a hydrogel based photovoltaics (HGPV) is a low-cost, environmentally friendly device and requires easy fabrication process. In this paper, the effect of hydroquinone additive on the performance of the HGPV is discussed. The photocurrent increases ~14 times upon the addition of hydroquinone into the agarose hydrogel medium. The photocurrent increase is maximum at the optimum dye concentration, while the photovoltage is barely affected by the dye concentration. The effect of the agarose content in the hydrogel and the types of dyes on the photocurrent is also investigated. Finally, it is shown that the photovoltaic performance of HGPV with hydroquinone can be drastically improved when $TiO_2$ film is deposited on the anode electrode.

• Korean Journal of Food Science and Technology
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• v.12 no.4
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• pp.285-291
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• 1980

The hydration and cooking rate of two rice varieties, Akibare (Japonica) and Milyang 23 (Indica), were investigated in terms of mathematical rate equations. The hydration rate at temperatures of $10{\sim}40^{\circ}C$ was examined by weighing method. The absorption of liquid water by rice grain was directly proportional to the square root of the hydration time. The diffusion coefficient was given by the Arrhenius relation : $D=3.151{\times}10^{-3}\exp\;(-4000/RT)$ for Akibare and $D=5.853{\times}10^{-3}\exp\;(-5700/RT)$ for Milyang 23. Milyang 23 was cooked at a faster rate than Akibare. The activation energies for cooking were in the range of 18 000 cal/mole at $90{\sim}100^{\circ}C$ and 9,000cal/mole at $100{\sim}120^{\circ}C$. However, Milyang 23 showed slightly higher activation energy of cooking at $90{\sim}100^{\circ}C$. Adhesiveness and amylograph viscosities at all reference points for Milyang 23 were higher than those for Akibare.

• Journal of Adhesion and Interface
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• v.8 no.3
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• pp.9-15
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• 2007

The interfacial evaluation of surface modified Jute fiber/polypropylene (PP) composites before and after hydration was investigated using micromechanical test and dynamic contact angle measurement. The IFSS of alkaline and silane-treated Jute fiber/PP composites increased, whereas after hydration, the IFSS of the untreated, alkaline- and silane-treated Jute fibers/PP composites decreased due to swelled fibrils by water infiltration. The interfacial adhesion of silane treated fiber/PP composites was higher than alkaline-treated or the untreated cases. The surface energies of Jute fiber treated under various conditions were obtained using dynamic contact angle measurement. Especially after hydration, the thermodynamic work of adhesion was calculated by considering water interlayer, which indicated the stability of IFSS between silane treated Jute fiber and PP matrix showing better than others.