• Korean Journal of Food Science and Technology
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• v.38 no.3
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• pp.419-426
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• 2006

A thermophilic microorganism, strain JE 375, which produces a thermostable protease, was isolated from soil and compost in Korea. This gram-positive, rod-shaped, catalase positive, motility positive, and hemolysis ${\beta}$ containing organism was implicated in glucose fermentation, mannitol fermentation, xylose oxidation, aerobic activity and spore formation. The color of the colony was yellowish white. The temperature range for growth at pH 6.5 was between 55 and $70^{\circ}C$, with an optimum growth temperature of $65^{\circ}C$. This result confirmed the strain JE 375 as a thermophilic microorganism. The enzyme was produced aerobically at $65^{\circ}C$ during 20 hr in a medium (pH 6.5) containing 1% trypton. 1% maltose, 0.5% yeast extract and 1% NaCl. The 16S rDNA of strain JE 375 had 97.6% sequence similarity with the 16S rDNA of Bacillus caldoxyloyticus. On the basis of biochemical and physiological properties and phylogenetic analysis, we named the isolated strain as Bacillus sp. JE 375. The thermostable protease from Bacillus sp. JE 375 had been partially purified and characterized. The molecular weight of the enzyme was deduced from SDS-PAGE and gel chromatography as 55 kDa and its optimal temperature was $60^{\circ}C$. The enzyme showed its highest activity at pH 7.5 and was stable from pH 7.0 to 8.0.

• Journal of Yeungnam Medical Science
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• v.1 no.1
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• pp.59-66
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• 1984

Although it is well established that steroid is effective for treatment of neonatal respiratory distress syndrome (NRDS), the action mechanism of steroid on NRDS is not well known. Several authors have insisted that steroid increases secretion of pulmonary surfactant from type II pneumocyte, but others have insisted that steroid does not affect the secretory function of the type II pneumocyte. And some authors have suggested that steroid may ca use compositional change of pulmonary surfactant phospholipid. From these aspects, it is desirable to confirm the effect of steroid on (he secretory function of the type II pneumocyte. In order to know the effect of steroid on pulmonary surfactant activity, phospholipid phosphorus of lung lavage was measured and composition of pulmonary surfactant phospholipid of lung lavage was analyzed by thin layer chromatography (TLC) in control (C), pneumonectomized (PN), and pneumonectomized with betamethasone treated (PNS) rabbits. And lung weight and lung weight-body weight ratio were measured in each experimental group also. In PN group, right lung pneumonectomy was performed under general anesthesia with pentobarbital sodium (30mg/kg). On the fifth day after the surgery, the left lung was excised and measured above parameters. In PNS group, pneumonectomy was performed as PN group, and one day after the surgery, betamethasone was injected for four days intramusculary (4mg/day) and rabbits were sacrificed. The experiment yielded following results. PNS group's lung weight was significantly (p<0.01) heavier than C group's, but in comparison with PN group's it showed no significant change. PNS group's L/B ratio was significantly (p<0.05) higher than C group's, but compared with PN group's it showed no significant change. The value of phospholipid phosphorus content of PNS group was significantly (p<0.01) higher than that of C group. Even if the value of phospholipid phosphorus content in PNS group was not significantly higher than that of PN group, it showed increasing tendency compared with that of PN group. And in an analysis of the thin layer chromatogram, quantity (${\mu}mol/gm$ of wet weight lung) of phosphatidylcholine in PNS group decreased significantly (p<0.05) compared with C and PN group. From these results, it may be suggested that though steroid inhibits cellular hyperplasia in the compensatory growing lung, it auguments the secretory function of type II pneumocyte and causes compositional change of pulmonary surfactant phospholipid.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.12
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• pp.1731-1737
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• 2000

This study was conducted to investigate the effects of threonine:lysine ratios on growth performance, apparent nutrient digestibility and blood urea nitrogen (BUN) concentration, and to estimate the optimal threonine:lysine ratios for growing barrows and gilts. A total of 150 pigs (Landrace${\times}$Yorkshire${\times}$Duroc, $16.75{\pm}0.42kg$ average body weight, 75 barrows and 75 gilts) was randomly allotted into six treatments in a $2{\times}3$ factorial design. Six diets were formulated to contain 1.12% lysine for barrows and 1.33% lysine for gilts with three threonine:lysine ratios (50, 60 and 70%) for both barrows and gilts. Throughout the whole experimental period (16 to 56 kg body weight), there was no interaction between sex and dietary threonine:lysine ratio in average daily gain (ADG), average daily feed intake (ADFI) and feed conversion rate (FCR). Between sexes, there was a clear sex-effect showing better growth performance of barrows. Barrows consumed more feed (p<0.01) and grew faster (p<0.01) than gilts. For barrows, there was a trend to improved ADG and FCR with increasing threonine:lysine ratio. For gilts, there was a trend to improved ADG and FCR up to threonine:lysine ratio of 60%, but not significant. There was no interaction between sex and threonine:lysine ratio in nutrient digestibilities of growing pigs except for crude ash (CA). Between sexes, there were differences in nutrient digestibilities, except for calcium for which gilts showed higher a digestibility (p<0.01). Among dietary threonine:lysine ratios, there were no differences in nutrient digestibilities. Mean values of essential amino acids (EAA), non-essential amino acids (NEAA) and total amino acids (TAA) digestibilities were not affected by sex and dietary threonine:lysine ratio. There was no evidence of an interaction between sexes and dietary threonine:lysine ratio. Between sexes, total BUN concentration was lower in gilts than barrows (p<0.05). It was concluded that a 70 and 60% dietary threonine:lysine ratio for barrows (1.12% lysine) and gilts (1.33% lysine) tended to result in better growth performances and nutrient utilization and lower BUN concentration than other threonine:lysine ratios.

• Korean journal of applied entomology
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• v.32 no.3
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• pp.307-316
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• 1993

The potential of using GIS in analyzing pest surveillance data was explored. The Spatial Analysis System (SPANS) was used to construct a spatial data base to study pest distributions using pest surveillance data collected from 152 stations in South Korea. The annual spatIal distributions of the striped rice borer(SRB), Chdo suppressalis, showed that high densities started to expand in the early 1980s, reaching a peak in 1988. The pattern change appears to be related to cultivation of japonica and indica-japonica hybrid varieties in South Korea. Japo7l!ca varieties have longer duration resulting in the SRB haVlng more time to mature and hibernate in wmter. The locus of SRB spread appears to be located in the mid-west region near lri, Chun~ Buk Province. High brown planthopper (BPH) populations in South Korea are often related to the early immigration and temperature. The simulated distribution of PPH densities in September using these two factors was compared with the actual distribution obtained using 1990 data. The two density maps corresponded closely excepL for differences in the south eastern valley. By overlaying the simulated map layer with the elevation and rice area maps, more specific BPH risk zones could be identified.

• Korean Journal of Plant Taxonomy
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• v.48 no.1
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• pp.9-23
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• 2018

The distribution of orbicules was investigated for eleven taxa of six genera in Lamiaceae and four taxa of three genera in Verbenaceae using scanning electron microscopy. A literature survey to evaluate the phylogenetic potential of the orbicules and their possible correlations with tapetum types was also conducted. The orbicules are consistently absent in all investigated taxa of Lamiaceae, while small orbicules of an average size of less than $1{\mu}m$ are densely distributed in Verbenaceae. In fact, orbicules appear consistently in 123 of 150 angiosperm families when investigated in at least one species. Thus, the distribution patterns of orbicules could be a useful diagnostic character in angiosperms. In addition, orbicules occur in 84% taxa of the secretory tapetum type, while they are commonly absent in the amoeboid tapetum type (ca. 80%). The presence of orbicules may be correlated with the secretory tapetum type. However, the study of orbicules is restricted in 150 families and the tapetum type within these families can be applied for 92 families out of a total of 416 angiosperm families. Thus, further investigation of orbicules is necessary in extended taxa to address the questions pertaining to orbicules.

• The Journal of the Petrological Society of Korea
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• v.14 no.3 s.41
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• pp.169-179
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• 2005

Acidic metavolcanic rocks distributed around the Chungju iron deposit show significantly high abundances of rare earth elements and high field strength elements. Relatively high ${\epsilon}_{Nd}$(0) values and lack of negative Nb anomaly suggest that assimilation of crustal material is not involved in their generation. They are plotted within the within-plate environment according the tectonic discrimination diagrams. Such geochemical characteristics are very similar to the acidic metavolcanic rocks of Munjuri Formation. They also show geochemical characteristics of Al-type magma of Eby (1992). All such diagnostic characters indicate differentiation of mantle-derived magma produced from the rift environment, related to the breakup of continent. In contrast to the alkali granites and the rare metal deposit both having age of c. 330 Ma, Sm-Nd isotopic data of the acidic metavolcanic rocks do not form well defined isochron. However, the alkali granites reveal low ${\epsilon}_{Nd}$(0) values, while the acidic metavolcanic rocks and the rare metal deposit both have significantly higher ${\epsilon}_{Nd}$(0) values. Considering such differences, we propose following generation hypothesis: The acidic metavolcanic rocks around Chungju iron deposit was erupted at 750 Ma as rest of the acidic metavolcanic rocks of Gyemyeongsan and Munjuri Formations. About 330 Ma ago, partial melting of existing Al-type igneous materials and some old crustal materials produced alkali granite. The rare metal deposit was also produced by redistribution of related materials within the acidic volcanics due to hydrothermal activities occurred at the same time. Sm-Nd isotopic systematics of the acidic metavolcanic rocks were disturbed during the regional metamorphic event at ca. 280 Ma.

• The Journal of the Petrological Society of Korea
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• v.19 no.3
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• pp.199-208
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• 2010

The Cenozoic alkali basalts are distributed over Korea, both on central part as Bangnyeongdo, Ganseong, Pyeongtaek-Asan and Jogongni and also on southernmost part Jejudo. The ultramafic mantle xenoliths carried by Korean alkali basalts are spinel lherzolites. Garnet lherzolite that is more stable at the deeper level has not been reported so far, indicating that the lithospheric thickness under Korea does not reach deep enough to the stable zone of garnet lherzolite. The crustal evolution history of the Korean peninsula, at least some part of it, seemingly started since the Archean, it normally should have lithospheric thickness greater than 150 km. However, the mantle xenoliths carried by the Cenozoic alkali basalts indicate the maximum depth of origination in the much shallower range of 60-90 km. Such significantly thinner lithospheric thickness of the Korean peninsula than expected is quite similar to the case of North China Craton having lithospheric thickness of ca. 80 km in average, suggesting thinning of the lithospheric mantle in a depth scale of a few tens of kilometers during the past geologic time. The main causal events for such significant thinning of the lithospheric mantle can be continental collisional events of Paleoproterozoic and early Mesozoic similar to the case of North China Craton, which are also supported by Paleoproterozoic igneous and metamorphic events during the 1.9-2.0 Ga occurring all over the Korean peninsula and also early Mesozoic continental collisional event which has been discussed on lively arguments.

• Journal of The Korean Astronomical Society
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• v.51 no.1
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• pp.17-25
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• 2018

Detecting exoplanets around giant stars sheds light on the later-stage evolution of planetary systems. We observed the M giant HD 18438 and the K giant HD 158996 as part of a Search for Exoplanets around Northern circumpolar Stars (SENS) and obtained 38 and 24 spectra from 2010 to 2017 using the high-resolution Bohyunsan Observatory Echelle Spectrograph (BOES) at the 1.8m telescope of Bohyunsan Optical Astronomy Observatory in Korea. We obtained precise RV measurements from the spectra and found long-period radial velocity (RV) variations with period 719.0 days for HD 18438 and 820.2 days for HD 158996. We checked the chromospheric activities using Ca $\text\tiny{II}$ H and $H{\alpha}$ lines, HIPPARCOS photometry and line bisectors to identify the origin of the observed RV variations. In the case of HD 18438, we conclude that the observed RV variations with period 719.0 days are likely to be caused by the pulsations because the periods of HIPPARCOS photometric and $H{\alpha}$ EW variations for HD 18438 are similar to that of RV variations in Lomb-Scargle periodogram, and there are no correlations between bisectors and RV measurements. In the case of HD 158996, on the other hand, we did not find any similarity in the respective periodograms nor any correlation between RV variations and line bisector variations. In addition, the probability that the real rotational period can be as longer than the RV period for HD 158996 is only about 4.3%. Thus we conclude that observed RV variations with a period of 820.2 days of HD 158996 are caused by a planetary companion, which has the minimum mass of 14.0 $M_{Jup}$, the semi-major axis of 2.1 AU, and eccentricity of 0.13 assuming the stellar mass of $1.8 M_{\odot}$. HD 158996 is so far one of the brightest and largest stars to harbor an exoplanet candidate.

• Journal of the Korean Institute of Gas
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• v.23 no.6
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• pp.39-60
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• 2019

Korea Gas Safety Corporation is developing consequence analysis system for combustible materials release events to enhance risk assessment technology and its efficiency. Unlike general consequence analysis programs, the final consequence area was implemented through ETA analysis based on API-581 standard, and a convenient user interface was constructed based on HTML5-based responsive web technology. In addition, a phase equilibrium module using third-order state equations (such as Peng-Robinson, SRK, and RK) and fugecity was implemented to analyze the mixture quality. Also. using the consequence analysis algorithm introduced in CCPS books and TNO Yellow Book, we developed material leak analysis module, fireball, pool fire, jet fire, flash fire, and vapor cloud explosion consequence assessment module. In addition, the conditions for calculating the safety distance were prepared with using the control values in the EIGA standard, PAC, and Bevi Reference Book.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.7
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• pp.779-785
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• 2015

Cathodic protection is recognized as the most cost-effective and technically appropriate corrosion prevention method for the submerged zone of offshore structures, ships, and deep-sea facilities. When cathodic protection is applied, the cathodic currents cause dissolved oxygen reduction, generating hydroxyl ions near the polarized surface that increase the interfacial pH and result in enhanced carbonate ion concentration and precipitation of an inorganic layer whose principal component is calcium carbonate. Depending on the potential, magnesium hydroxide can also precipitate. This mixed deposit is generally called "calcareous deposit." This layer functions as a barrier against the corrosive environment, leading to a decrease in current demand. Hence, the importance of calcareous deposits for the effective, efficient operation of marine cathodic protection systems is recognized by engineers and scientists concerned with cathodic protection in submerged marine environments. Calcareous deposit formation on a marine structure depends on the potential, current, pH, temperature, pressure, sea-water chemistry, flow, and time; deposit quality is significantly influenced by these factors. This study determines how calcareous deposits form in sea water, and assesses the interrelationship of formation conditions (such as the sea water temperature and surface condition of steel), deposited structure, and properties and the effectiveness of the cathodic protection.