• Archives of Pharmacal Research
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• v.24 no.2
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• pp.159-163
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• 2001

The accelerated stability of dimethoxy biphenyl monocarboxylate.HCl (DDB-S) was investigated in 6 mg/mL water solution in the pH ranging 2-10 and the temperature of $45-85^{\circ}C$. The observed rate of degradation followed first-order kinetics. The energy of activation for DDB-S degradation was calculated to be 14.1 and 16.5 $Kcal/mole$ at pH 5 and in distilled watery respectively. The degradation rate constant ($K_{25^{\circ}C}$) obtained by trending line analysis of Arrhenius plots for DDB-S was $5.3{\times}10^{-6}h^{-1}$. The times to degrade 10% ($t_{10}$) and 50% $t_{500}$) at $K_{25^{\circ}C}$ were 829 and 5,416 days, respectively. DDB-S exhibited the fastest degradation at pH 10 and the slowest rate at pH 5. In addition, at $K_{65^{\circ}C}$, degradation rate constants of DDB-S were 0.066, 0.059, 5.460, 32.171, and $1.4{\times}10^{-6}h^{-1}$ at pH 2, 5, 8, 10 and in distilled water, respectively. These observations indicated that the rate-pH profile of DDB-S showed general acid-base catalysis reaction in the range of pH 2-10.

• Electrical & Electronic Materials
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• v.1 no.1
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• pp.26-34
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• 1988

Sintered CdS/CdTe solar cells have been farbricated by coating a (Cd+Te) slurry on sintered CdS films followed by the sintering at 625.deg.C for one hour with various heating rates. When cadmium and tellurinm powders are used instead of CdTe powder to form CdS/CdTe junction, CdTe is formed in the temperature range of 290.deg.C-400.deg.C. The microstructure of the CdTe films depends strongly on the heating rate of the sintering due to the low melting temperature and the high vapor pressure of the elemental Cd and Te. An optimum heating rate obtain CdTe films with uniform and dense microstructure which, in turn, improves the efficiency of the sintered CdS/CdTe solar cells. All-polycrystalline CdS/CdTe solar cells with an efficiency of 9.57% under 50mW/cm$^{2}$ tungsten light have been farbricated by using a heating rate of 14.deg.C/min.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.3
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• pp.235-238
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• 2009

This paper describes the mechanical properties of poly (Polycrystalline) 3C-SiC thin films with $N_2$ in-situ doping. In this work, the poly 3C-SiC film was deposited by APCVD (Atmospheric Pressure Chemical Vapor Deposition) method using single-precursor HMDS (Hexamethyildisilane: $Si_2(CH_3)_6)$ at $1200^{\circ}C$. The mechanical properties of doped poly 3C-SiC thin films were measured by nono-indentation according to the various $N_2$ flow rate. In the case of 0 sccm $N_2$ flow rate, Young's Modulus and hardness were obtained as 285 GPa and 35 GPa, respectively. Young's Modulus and hardness were decreased according to increase of $N_2$ flow rate. The crystallinity and surface roughness was also measured by XRD (X-Ray Diffraction) and AFM (Atomic Force Microscopy), respectively.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.4 no.2
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• pp.3-9
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• 2005

In this study, the chip breaking characteristics of S, PbS and BiS free machining steels have been assessed. PbS free machining steel shows the lowest value of chip thickness ($t_c$) under the same cutting conditions. SM10C steel has the largest value of the chip cross-section area ratio ($R_{CA}$). As the feed rate becomes larger the chip breaking cycle time ($T_B$) decreases and the chip breaking index ($C_B$) increases. The properly controlled-C type chip has been obtained with the value of $C_B$ between 0.05 and 0.2. Free machining steel, PbS produces the properly controlled-C type chip in a wider feed rate range than other steels.

• Korean Journal of Food Science and Technology
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• v.7 no.3
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• pp.135-140
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• 1975

Among many honeys, the buckwheat honey was the best one using for Yackwa(a Korean cookie). We made a substitute, similary syrups of buckwheat honey, and then we got the following conclusions through the case of the similar syrups. 1. The best syrups are A, B and C syrup. A syrup's composition rate was sugar (40%), corn-syrup (20%) and water (40%) before boiling for 10 minutes. B syrup's composition rate was water (40%), glucose (20%), corn-syrup (20%) and sugar (20%) before boiling for 15 minutes. C syrup's composition rate like B syrup's but boiled for 10 minutes. 2. The best syrups used for dough are A and B syrup. C syrup was good for soaking. When A syrup used for dough, we have to immediate soaking in A syrup after frying or soaking in C syrup an hour later after frying. When B syrup used for dough, we must soaking in C syrup an hour later after frying. 3. The rate of fat in the composition of buckwheat honey's, A syrup's and B syrup's Yackwa was 27.22%, 23.05%, 23.05% and 30.35%.

• Proceedings of the KSME Conference
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• 2001.06c
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• pp.525-530
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• 2001

As a part of efforts to examine feasibility of warm forging near-net-shape process for non-heat-treated steel to replace quenched and tempered S45C steel, the optimized process condition has been determined to be $820^{\circ}C$ for heating, 10/sec for strain rate of forging and approximately 250MPa for flow stress from observed results such as the $A_{3}$ transformation temperature of about $790^{\circ}C$, the fully dynamic recrystallized behavior between $800^{\circ}C\;and\;850^{\circ}C$ when compressed up to 63% engineering strain at 10/sec strain rate, and the high temperature microsturctural stability. Also, controlled cooling rate of $6.3^{\circ}C/sec$ by water-spraying at a rate of $0.10cc/sec-cm^{2}$ for 60seconds followed by air-cooling right after forging process has been considered in this study as a feasible approach based on examination of the microsturcture of mixed ${\alpha}-ferrite$ and pearlite, the hardness and tensile properties meeting specification, and the reduced total cooling time to room temperature. Successive works would be carried out for the impact strength, machinalility, and forgeability at this process in the near future.

• Applied Chemistry for Engineering
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• v.20 no.4
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• pp.423-429
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• 2009

The purpose of this study is to investigate the optimal condition for the hydrogen-rich gas production and the CO removal by reforming of gliding arc plasma reforming system using biogas. The parametric screening studies were carried out according to changes of steam feed amount, catalyst bed temperature in water gas reactor and catalyst bed temperature, input air flow rate in preferential oxidation reactor. The standard condition is as follows. The steam/carbon ratio, catalyst bed temperature, total gas flow rate, input electric power and biogas composition rate ($CH_4$ : $CO_2$) were fixed 3, $700^{\circ}C$, 16 L/min, 2.4 kW and 6 : 4, respectively. The results are as follow, HTS optimum operating conditions were S/C ratio of 3 and reactor temperature of $500^{\circ}C$. LTS were S/C ratio of 2.9 and temperature of $300^{\circ}C$. Also, PROX I optimum conditions were input air flow rate of 300 mL/min and reactor temperature of $190^{\circ}C$. PROX II were 200 mL/min and $190^{\circ}C$ respectively. After having passed through each reactor, the results were as follows: 55% of $H_{2}$ yield, 0% of CO selectivity, 99% of $CH_4$ conversion rate, 27% of $CO_2$ conversion rate, respectively.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.92-95
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• 2008

We performed the theoretical calculation of CN Violet radiation using the code SPRADIAN07 to predict the Lee et al.'s experimental measurements and to reinvestigate $C_2$ dissociation rate. CN Violet radiations are calculated under the Boltzmann and non-Boltzmann distribution using two chemical reaction sets: Park-Losev-G\"{o}kcen-Tsang and Park-Losev-G\"{o}kcen-Tsang-Lee models. Our SPRADIAN07 calculations show improvement in prediction of absolute radiation intensity of CN Violet and its decay rate by Park-Losev-G\"{o}kcen-Tsang reaction set with $C_2$ dissociation rate coefficient of $k_f$ = 1.5${\times}$10$^{16}$ exp(-71,600/$T_x$) cm$^3$ mole$^{-1}$ s$^{-1}$.

• The Korean Journal of Malacology
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• v.31 no.1
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• pp.35-41
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• 2015

In order to investigate the live food value of microalgae for efficacious rearing of larvae and spats of bivalve, we studied growth rates of four microalgal species (Isochrysis galbana, Pavlova lutheri, Chaetoceros simplex, Tetraselmis tetrathele) cultured in different environmental conditions. These include changes in temperatures (20, 25, 30 and $35^{\circ}C$), salinities (20, 25, 30 and 33 psu) and light intensities (60, 100 and $140{\mu}mol\;m^{-2}s^{-1}$). The growth rate of I. galbana was faster at $25^{\circ}C$ than that of $20^{\circ}C$. At $25^{\circ}C$ the highest growth rate of I. galbana was observed at 33 psu (0.413) and the lowest at 20 psu (0.368) in 10 days of culture (P < 0.05). The growth rate of I. galbana was lower at 25 psu (0.383) than that of 30 psu and higher than that of 20 psu (P < 0.05). Similar temperature and salinity-dependent changes were also found in P. lutheri and T. tetrathele. C. simplex showed faster growth rate at $30^{\circ}C$ than that of $25^{\circ}C$. The highest growth rate of C. simplex was observed at 33 psu (0.428) and the lowest at 20 psu (0.389) in 10 days of culture (P < 0.05). Upon exposure to the light with different intensities, all four microalgal species showed a significantly faster growth rate at $140{\mu}mol\;m^{-2}s^{-1}$ than at $100{\mu}mol\;m^{-2}s^{-1}$ (P < 0.05).

• Journal of IKEEE
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• v.23 no.1
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• pp.1-8
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• 2019

In this paper, the electrical characteristics with various C-rates are tested with a high power series battery pack comprised of 18650 cylindrical nickel cobalt aluminum(NCA) lithium-ion battery. The electrical characteristics of discharge capacity test with 14S1P battery pack and electric vehicle (EV) cycle test with 4S1P battery pack are compared and analyzed by the various of C-rates. Multiple linear regression is used to estimate voltage imbalance of 14S1P and 4S1P battery packs with various C-rates based on experimental data. The estimation accuracy is evaluated by root mean square error(RMSE) to validate multiple linear regression. The result of this paper is contributed that to use for estimating the voltage imbalance of discharge capacity test with 14S1P battery pack using multiple linear regression better than to use the voltage imbalance of EV cycle with 4S1P battery pack.