• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.17 no.4
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• pp.377-381
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• 1988

Effects of thermal resistance of mold during freezing processes have been investigated. Saturated liquid is chosen to present one-dimensional quasi-steady solution and this solution is compared with numerical solutions. Front tracking finite element method has been applied for the numerical solutions. Results show that mold should be considered as well as phase change material except the cases when the very thin mold with relatively high thermal conductivity is used.

• Applied Chemistry for Engineering
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• v.8 no.4
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• pp.645-652
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• 1997

Electrochemical characteristics and kinetic parameters of copper ion reduction were investigated with a platinum rotating disk electrode (RDE) in a diffusion controlled region. Reduction of Cu(II) in sulfate had one-step two-xelectron process, while the reduction of Cu(II) in chloride solution was involved two one-electron processes. The transfer coefficient of Cu(II) in sulfate solution was lowest, and the transfer coefficient of Cu(I) in halide solutions had the value of nearly one. In chloride solutions, electrodeposition rate of Cu(II) was about one hundred times faster than Cu(I). Diffusion coefficient increased in the order of Cu(II) in chloride solution, Cu(I) in the iodide, bromide, chloride solution, Cu(II) in sulfate solution. The calculated ionic radii and activation energy for diffusion decreased in the same order as above. Morphological study on the copper electrodeposition indicated that the electrode surface became rougher as both concentration and reduction potential increases, and the roughness of the surface was analyzed with UV/VIS spectrophotometer.

• Journal of the Korean Chemical Society
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• v.23 no.1
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• pp.7-14
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• 1979

Changes in CD, ORD and uv-spectra during the mutarotation of poly(trans-5-methyl-L-proline) (PTMP) were studied. The forward mutarotion of PTMP occurred in strong organic acids and trifluoroethanol, while the reverse mutarotation was observed by dilution of the trifluoroethanol solution with excess aliphatic alcohols. The changes in CD, ORD and uv-spectra during the forward and reverse mutarotation proceeded paralell to those found for the mutarotation of polyproline. The chemical shift of the ${\alpha}CH-$proton was shifted downfield about 0.3 ppm during the forward mutarotation. The reduced viscosity for the forward mutarotation increased from 0.15 to 0.26 (dl/g) during 5 days. The equilibrium between form I and form II was estabilished in an appropriate solvent mixture. All changes in solution properties mentioned above are similar to those found for polypoline. These results support that the two forms of PTMP are the same conformations as polyproline form I and form II, i. e., a right-handed helix with all cis amide bonds and a lefthanded helix with all trans amide bonds.

• Archives of Pharmacal Research
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• v.7 no.1
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• pp.47-52
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• 1984

Four polymorphic forms (I, II, III and IV) of hydrochlorothiazide have been characterized on the basis of x-ray diffractometry and differential thermal analysis. Form I was obtained by crystallization from N, N-dimethylformamide and Form II was crystallized from hot methanol. Form III was precipitated from sodium hydroxide aqueous solution by treatment with hydrochloric acid and Form IV was crystallized from 50% methanol. The metastable form I was a most stable form among four polymorphs, which was stable more than ten months at room temperature. The thermodynamic parameters such as heat of solution, enthalpy, entropy, free energy difference and transition temperature were determined by the measurement of intrinsic dissolution rate. The transition temperature and the heat of transition between the metastable Form I an Form II were determined to be $299.15^{\circ}$K and 5.03 Kcal/mole, respectively and free energy difference ($\delta$ F) was 302. 13 cal/mole. Diuretic action of these four polymorphic forms was also evaluated by monitoring the difference in urinary excretion of sodium, potassium and magnesium in rats.

• Journal of the Korea Society of Computer and Information
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• v.21 no.6
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• pp.77-81
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• 2016

This paper deals with the optimization problem that decides the routing of connection between multi-source and multi-sink. For this problem, there is only in used the mathematical approach as linear programming (LP) software package and has been unknown the polynomial time algorithm. In this paper we suggest the heuristic algorithm with $O(mn)^2$ time complexity to solve the optimal solution for this problem. This paper suggests the simple method that assigns the possible call flow quantity to augmenting path of ($s_i,t_i$) city pair satisfied with demand of ($s_i,t_i$). The proposed algorithm can be get the same optimal solution as LP for experimental data.

• Advances in concrete construction
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• v.10 no.6
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• pp.509-514
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• 2020

In the preliminary design phase of explosion-proof structures, the use of P-I diagram is useful. Based on the fact that the deformation criteria at failure or heavy damage is significantly larger than the yield deformation, a closed form solution of normalized P-I diagram is proposed using the complete plastic resistance curve. When actual sizes and material properties of RC structural component are considered, the complete plasticity assumption shows only a maximum error of 6% in terms of strain energy, and a maximum difference of 9% of the amount of explosives in CWSD. Thru comparison with four field test results, the same damage pattern was predicted in all four specimens.

• Analytical Science and Technology
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• v.22 no.6
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• pp.519-523
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• 2009

$^{129}I$ is especially one of the most harmful radioactive elements because of its long half-life ($t_{1/2}$=$1.7{\times}10^7$ yr). The efficient removal of iodide ($I^-$) and iodate (${IO_3}^-$) in a aqueous solution by adsorption using activated alumina and activated carbon was studied. The removal efficiency was over 99% for iodide ion with silver treated basic alumina and iodate ion with acidic alumina or silver treated acidic alumina without any chemical addition or physical treatments.

• Journal of Chest Surgery
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• v.29 no.9
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• pp.931-939
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• 1996

An experimental comparative study was done to determine the protective effects of three preservation solutions on isolated rabbit heart-lung bloc during acute ischemia and reperfusion of the lung during lung transplantation. Thirty Isolated rabbit heart-lung blocs were divided into 3 groups , group I(n:9) was preserved with Hartmann's solution, group II(n: 10) with modified University of Wisconsin solution, and group III(n: 1 1) with Kosin solution. The isolated heart-lung blocs were washed with Hartmann's so ution. Aftar infusion of each preservation solution into pulmonary artery, the heart-lung bloc was stored at 4'c cold preservation solution for each group for 4 hours and .then the heart-lung blocs were reventilated and reperfused. The changes of weight of heart-lung blocs, airway pressure, percent change of PCO2, level of lactate and adenosine deaminase(ADA) and microscopic structure of the lung parenchyme were evaluated. Results were as follows 1. A change of weight of the heart lung bloc after reperfusion was lowest in group 111(p< .05) 2. The airway pressure increased after reperfusion in group I but decreased in group II, and II. Especially in group II, post-reperfusion airway pressure returned to level lower than that of en-bloc resection. 3. Pulmonary artery pressure during reperfusion after 4 hour preservation was lowest in group III, and pulmonary artery pressure in group II was higher than in group I(P> 0.1). 4. The level of lactate and ADA in the lung tissue were higher in group III than in group I and II(P< .05) 5. The percent change of PCO2 in perfusate was slightly higher in group III than group I and II. 6. Microscopic changes in lung tissue after reperfusion were diffuse pulmonary edema, expansion of inter- stitial tissue, focal aggregation of erythrocytes, and basement membrane abnormalities, but no differences were found among the three groups. In conclusion, the protective effects of modified University of Wisconsin solution and Kosin solution were slightly superior to Hartmann's solution.

• KSBB Journal
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• v.17 no.3
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• pp.283-289
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• 2002

The present study was aimed at investigating the metabolic regulation of insulin-like growth factor-I(IGF-I) expression in fasting animals. The expression of IGF-I gene was determined by a solution hybridization/RNase protection assay using total RNA from control, 4d-fasting, and 2d-fasting-refed rats. The levels of IGF-I transcripts were reduced in 4d-fasting than in control by decreasing its transcriptional rate, which was measured through nuclear nun-on assay. DNase I footprinting, which was performed using nuclear extracts from fasting rat, demonstrated protein binding to a sequence that extended from +179 to +210 (termed region B). These data suggest that the expression of IGF-I is transcriptionally regulated through DNA-liver enriched protein binding in a sequence which is located downstream from major transcription initiation site of IGF-I gene.

• Korean Journal of Animal Reproduction
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• v.16 no.3
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• pp.269-276
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• 1992

Studies were carried out to find the freezing media which gives no ice crystals in single(glycerol, ethylene glycol, dimethyl sulfoxide(DMSO)) and mixture solutions(glycerol＋propylene glycol, glycerol＋ethylene glycol) of permeable cryoprotectants in vitrification solution and to study effects of VS on the survival of vitrified mouse morulae. The results are summarized as follows: 1. In toxicity test of permeable cryoprotectants, 30% glycerol of single solution showed the highest FDA-score(4.1) in mouse morulae frozen compared among other single solutions. The FDA-score(4.1) of 30% glycerol was higher than 30% ethylene glycol(3.6) and DMSO(1.4( (P<0.05). 2. 20, 30 or 40% single solution of permeable cryoprotectants containing m-PBS with 10% sucrose and 20% BSA was not crystallized during cooling, but crystallized during warming. However, the 30% mixture solution of the two permeable cryoprotectants was not crystallized both during cooling and warming.3. When mouse morulae were frozen in 30% mixture solutions of two permeable cryoprotectants(glycerol and propylene glycol, glycerol and ethylene glycol), highest FDA-score(4.5) was obtained in a mixture solution of 20% glycerol and 10% ethylene glycol(20G10E) than other 30% mixture solutions(10G20E, 15G15E, 20G10P, 15G15P, 10G20P) and there was significant difference between 20G10E and 10G20E(P<0.05).