• Journal of the Korean Crystal Growth and Crystal Technology
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• v.19 no.1
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• pp.39-47
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• 2009

The effects of thermo-solutal convection on mercurous chloride system of ${Hg_2}{Cl_2}$, and Ne during physical vapor transport are numerically investigated for further understanding and insight into essence of transport phenomena, For $10\;K{\le}{\Delta}T{\le}30\;K$, the growth rate slowly increases and, then is decreased gradually until ${\Delta}T$=50 K, The occurrence of this critical point near at ${\Delta}T$=30 K is likely to be due to the effects of thermo-physical properties stronger than the temperature gradient corresponding to driving force for thermal convection. For the range of $10\;Torr{\le}P_B{\le}300\;Torr$, the rate is second order-exponentially decayed with partial pressures of component B, $P_B$. For the range of $5{\le}M_B{\le}200$, the rate is second order-exponentially decayed with a function of molecular weight of component B, $M_B$. Like the case of a partial pressure of component B, the effects of a molecular weight arc: reflected through the binary diffusivity coefficients, which are intimately related with suppressing the convection flow inside the growth enclosure, i,e., transition from convection to diffusion-dominant flow mode as the molecular weight of B increases. The convective mode is near at a ground level, i,e., on earth (1 $g_0$), and the convection is switched to the diffusion mode for $0.1\;g_0{\le}g{\le}10^{-2}g_0$, whereas the diffusion region ranges from $10^{-2}g_0$ up to $10^{-5}g_0$.

• Preventive Nutrition and Food Science
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• v.13 no.4
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• pp.306-312
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• 2008

This study investigated the influence of pH on the color development of melanoidins formed from amino acid enantiomer model systems. For this, the color development was evaluated by measuring browning at 420 nm and color measurements by spectrophotometry and colorimetry. The browning and browning index showed no difference according to the type of amino acid enantiomers, while that formed from the D-Asn system was the only difference according to pH level. The tristimulus value of melanoidins formed from all model systems was located on a dominant wavelength of 475 nm, the blue zone of the diagram. In addition, the $L^*$, $a^*$, $b^*$, $C^*_{ab}$ values, and ${\Delta}E^*$ index on the basis of the type of amino acid enantiomers, the differences were markedly found at pH 4.0. At pH 7.0, significantly differences were found in the $L^*$, $a^*$, $b^*$ values, and ${\Delta}E^*$ index and not in the case of the lysine enantiomers. In addition, at pH 10.0, the differences were found in the $a^*$ and $b^*$ values from the lysine enantiomers and $C^*_{ab}$ value from the asparagine enantiomers. Therefore, the color development of melanoidins was influenced by the type of amino acid enantiomers and pH levels. Especially, it is thought that the $a^*$ and $b^*$ values can be used to explain the differences among the amino acid enantiomers in the color development of melanoidins.

• Korean Journal of Microbiology
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• v.29 no.2
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• pp.80-84
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• 1991

We cloned and expressed hepatitis B viral core antigen (HBcAg) gene in E. coli using $P_{L}$ promoter system. For optimal expression of the gene, we undertook the studies on the effects of the distance between Shine-Dalgarno (SD) sequence and start codon, copy number of repressor gene, induction temperature, and the stability of the core antigen. The results demonstrated that the induction at 37.deg.C was more efficient than at 42.deg.C, and the 11 base pairs (bp) distance between SD sequence and start codon of HBcAg gene was more efficient than the 15 bp distance in E. coli. The copy number of cI857 repressor gene did not influence on the expression of HBcAg, and the expression level of HBcAg in mutant type (low protease activity) and wild type strains was almost the same. The produced core antigen appeared to be HBcAg not HBeAg judged by two different radioimmunoassat (RIA) kits. This result suggested that the antigen was stable in E. coli.i.

• Journal of architectural history
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• v.5 no.2 s.10
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• pp.9-24
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• 1996

Owing to the energitic studies of the leading shcolars, some paradigmatic theories on the history of Korean dwellings have been suggested. They constructed periodization of their own and defined characteristics of each period with very limited historical materials. However the new historical materials have been discovered in the neighboring academic fields, which require to review the existing theories. This study aims at restructuring periodization in the history of Korean dwellings during the age of The prehistory and The ancient Kingdomes. Through the study, the existing theories on the same period are revived and evaluated based on the new materials. I suggest a new theory on the periodization and the characteristics of each period: a. the paleolithic period(6,000,000 B.P.-10,000 B.P.) : natural shelter, the emergence of man-made dwellings b. the neolithic period(10,000 B.P.-1,000 B.C.) : construction of pit house c. the bronze period(1,000 B.C.- 300 B.C.) : construction of semi-pit house d. the early metalic period(300 B.C. - 300 AD.) : construction of house on the ground level development of the Ondol system e. the ancient kingdomes period(300 AD - 700 AD): classification of housing type

• Journal of Life Science
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• v.15 no.6 s.73
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• pp.972-978
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• 2005

The present study was carried out to investigate the blood markers of Jeju horses. The redcell cypes (blood groups) and blood protein types (biochemical polymorphisms) were tested from 102 Jeju horses by serological and electrophoretc procedure, and their phenotypes and gene frequencies were estimated. The blood group and biochemical polymorphism phenotypes observed with high frequency were $A^{af}\;(27.45\%$), $C^{a}\;(99.02\%$), $K^{-}\;(97.06\%$), $U^{a}\;(62.75\%$), $P^{b}\;(36.27\%$), $Q^{c}\;(47.06\%$), $D^{cgm/dghm}\;(13.73\%$), $D^{adn/cgm}\;(9.80\%$), $D^{ad/cgm}$\;(8.82\%$), $D^{dghm/dghm}(7.84\%$), $D^{cgm/cgm}(7.84\%$), $AL^{B}\;(48.04\%$), $GC^{F}\;(99.02\%$), $AlB^{K}\;(97.06\%$), $ES^{FI}\;(36.27\%$), $TF^{F2}\;(25.49\%$), $HB^{B1}\;(45.10\%$), and $PGD^{F}\;(86.27\%$) in Jeju horses, respectively. Alleles observed with high gene frequency were $A^{af}$ (0.3726), $A^{C}$ (0.2647), $C^{-}$ (0.5050), $K^{-}$ (0.9853), $U^{-}$ (0.6863), $P^{b}$ (0.4657), $Q^{c}$ (0.5294), $D^{cgm}$ (0.3039), $HB^{B1}$(0.6863), $PGD^{F}$ (0.9265), $AL^{B}$ (0.6912), $ALB^{K}$ (0.9852), $GC^{F}$ (0.9950), $ES^{I}$ (0.5000) and $TF^{F2}$ (0.4950) in Jeju horses, and sfecific alleles, $D^{cgm(f)}$ (0.0196), $HB^{A}$ (0.0147), $HB^{A2}$ (0.0196), $ES^{G}$ (0.0441), $ES^{H}$ (0.0098), $TF^{E}$TF'(0.0246), $TF^{H2}$ (0.0049) and $PGD^{D}$ (0.0098) were detected in Jeju horses. These preliminary results present basic information for detecting the genetic markers in Jeju horse. and developing a system for parentage verification and individuals identification in jeju horses.

• Toxicological Research
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• v.11 no.2
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• pp.205-213
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• 1995

This study was undertaken to investigate the effects of organic solvents on xenobiotic metabollzing enzyme system in vivo by meaas of experimental conditions i.e. (1) single group which was treated by benzene (B), toluene (T) and xylene (X), respectively, (2) combination group which was treated by mixture of benzene+toluene (BT), benzene+xylene (BX), and toluene+xylene (TX), respectively, (3) mixture group which was treated by benzene+ toluene+xylene mixture (M), and to interpreat the interaction between the organic solvents metabolizing enzymes. 1. The contents of cytochrome P-450 in liver microsomes were increased (p < 0.01) in organic solvents treated groups, and the contents of cytochrome P-450 were increased by following order of B < T < M < BT=BX < X < TX. 2. The activity of cytochrome P-450 dependent AHHase was significantly higher in organic solvents treated groups than in control group (p < 0.01), and the activity of AHHase was increased by following order of B < T < BT=BX=TX=xylene < M. 3. The activity of NADPH P-450 reductase was significantly higher in organic solvents treated groups than in control group (p < 0.01), and the order of M < combinated group < X < T

• Journal of the Korean Chemical Society
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• v.56 no.4
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• pp.416-423
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• 2012

Using time domain reflectometry, the complex dielectric spectra between 10 MHz to 20 GHz has been measured in the whole composition range at 10, 20, 30 and $40^{\circ}C$ for the binary mixtures of ethylene glycol and dimethyl sulfoxide. For all the mixtures, only one dielectric loss peak was observed in this frequency range. The relaxation in these mixtures can be described by a single relaxation time using the Debye model. A systematic variation is observed in dielectric constant (${\varepsilon}_0$) and relaxation time (${\tau}$). The excess permittivity (${\varepsilon}^E$), excess inverse relaxation time $(1/{\tau})^E$, Kirkwood correlation factor (g) and thermodynamic parameters viz. enthalpy of activation (${\Delta}H$) and Gibbs free energy of activation (${\Delta}G$) have been determined, to confirm the formation of hydrogen bonded homogeneous and heterogeneous cooperative domains, the dynamics of solute - solute interaction and the hindrance to molecular rotation in the hydrogen bonded glass forming ethylene glycol - dimethyl sulphoxide system.

• Journal of Power Electronics
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• v.10 no.6
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• pp.628-634
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• 2010

The paper describes aspects regarding an E-learning approach of resonant ac inverters. The learning process is based on "Learning by Doing" paradigm supported by several learning tools: electronic course materials, interactive simulation, laboratory plants and real experiments accessed by Web Publishing Tools under LabVIEW. Built on LabVIEW and accompanied by a robust, flexible and versatile hardware, the experiment allows a comprehensive study by remote controlling and performing real measurements on the inverters. The study is offered in a gradual manner, according to the Leonardo da Vinci project EDIPE ($\b{E}$-learning $\b{D}$istance $\b{I}$nteractive $\b{P}$ractical $\b{E}$ducation) philosophy: theoretical aspects followed by simulations, while in the end the real experiments are investigated. Studying and experimenting access is opened for 24 hours a day, 7 days a week under the Moodle booking system.

• Microbiology and Biotechnology Letters
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• v.23 no.6
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• pp.784-788
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• 1995

The lambda Integrase (Int) carries out site-specific recombination between the two partner DNA sequences, attachment P (attP) and attachment B (attB). In order to study the recombination mechanism, a large quantity of pure integrase is required. Then, we constructed an int gene inserted recombinant plasmid (pNYL3) by using the pQE31 HIS-Tag vector, and produced the fusion protein, 6xHIS-Int from the E. coli TG1 strain carrying the pNYL3 plasmid. The recombinant protein produced was purified by phosphocellulose and Ni$^{++}$-NTA affinity column chromatographies. The result of the in vitro recombination assay using the standard reaction mixture containing 6xHIS-Int and partially purified integration host factor (IHF) showed that the 6xHIS-Int tagged recombination Integrase had the full recombination activity.

• Microbiology and Biotechnology Letters
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• v.25 no.4
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• pp.339-345
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• 1997

Under the light intensity of 25-72$\mu$E/ m$^{2}$/s Botryococcus braunii UTEX 572 grew faster than Botryococcus sp. GE 24 isolated from a freshwater lake. The specific growth rate ($\mu$) of B. braunii UTEX 572 was highest at 0.260 (1/day) on a dry weight basis in Chu 13 medium from 1 to 9 days of incubation and then continuously decreased. Carbohydrate concentration and cellular nitrogen and phosphorus contents of B. braunii UTEX 572 gradually decreased with light intensity over a range of 25-72$\mu$E/m$^{2}$2/s, whereas the concentrations of protein and cellular N:P ratio increased with light intensity. Chlorophyll-a concentration showed a decreasing tendency with light intensity. The dry weight of B. braunii UTEX 572 increased in the highest rate of 83 mg/l/day at pH 8.0. When the N: P ratio of Chu 13 medium was adjusted to 50: 1 by addition of nitrogen source, dry weight increasing rate was 115 mg/l/day between 20 and 28 days of incubation which was the highest value during the cultivation. Cell growth in an open culture of B. braunii UTEX 572 was highest with Chu 13 medium, whereas that with Chu 13 medium adjusted to pH 7.0, containing 250 mg/l penicillin, or containing 1% glucose was reduced on a large scale. However, this result shows the possibility of the mass cultivation of B. braunii UTEX 572 in an open system competing with other microorganisms.