• Journal of Astronomy and Space Sciences
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• v.10 no.2
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• pp.123-145
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• 1993

UBVRi photometry of Algol was carried out from December of 1988 to March of 1991 at Chungbuk National University Observatory and a total of 3465 observations in U, B, V, R, I were obtained. Three times of primary minimum light of JDH el 2447898.0938, JEH el 2448265.1205 and JDH el 2448288.0598, and two secondary minimum light of JDH el 2447808.1014 and JDH el 2448275.146 were determined from our observations. We analyzed simultaneously the UBVRI light curves of the Algol system with the Wilson-Devinney method for the determination of the photometric parameters. Indivisual masses for the 3 components of Algol are derived as $m_1$=3.36, $m_2$=0.76, $m_3$=1.6 in solar mass and radii as $R_1$=2.97, $R_2$=0.76 in solar radinus using i=$82.{\circ}47$, q=0.227, $r_1$=0.2102, $r_2$=0.2512 of our solution and some parameters of the spectroscopic solution of Hill et al. (1971). Our results is simiar to those reported by Kim (1989). The temperature of Algol C, $T_3$=8800 was obtained by means of fitting $l_1$, $l_2$, and $l_3$ of five colors to Planckian curve, and $R_3$=$1.6R_\odot$ is derived from its result. It is believed that its semidetached configuration of Algol A and B is the consequence of case B mass transfer. According to its location in a mass-radius diagram. Algol b may have evolved significantly in its Hburnning phase.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.12
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• pp.4933-4938
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• 2014

Background: Although various tumor markers have been utilized in management of stomach cancer (SC), only a few reports have described relevance of examples such as CYFRA 21-1 and neuron-specific enolase (NSE). The purpose of this study was to evaluate the potential diagnostic performance of carcinoembryonic antigen (CEA), CA 19-9, CA72-4, CYFRA 21-1 and NSE in patients with SC. Materials and Methods: Ninety-six SC patients with pathologic confirmation between 2012 and 2013 were enrolled. Serum levels of five tumor markers were analyzed using a solid-phase immunoradiometric assay. Receiver operating characteristic (ROC) curves were plotted for the five tumor markers to investigate their diagnostic powers and adjusted cutoff values derived from analysis of ROC curves were evaluated to calculate the sensitivity of each for SC with recommended cutoff values. Results: Based on two different cutoff values (recommended and adjusted), CYFRA 21-1 (${\geq}2.0$ and 1.2 ng/ml) had a respective sensitivity of 50% and 78.1%, compared with 8.3% and 18.8% for CEA (${\geq}7.0$ and 3.9 ng/ml), 15.6% and 18.8% for CA 19-9 (${\geq}37$ and 26.7 ng/ml), 28.1% and 9.6% for CA 72-4 (${\geq}4.0$ and 13 ng/ml) and 7.3% and 7.3% for NSE (${\geq}14.7$ and 15.0 ng/ml) in the initial staging of primary SC. The area under the curve (AUC) for CYFRA 21-1, with a value of 0.978 (95% confidence interval, 0.964-0.991) was comparatively the highest. Univariate analysis revealed significant relationships between tumor marker level and lymph node involvement, metastasis and staging with CYFRA 21-1, CA 72-4 and NSE. Conclusions: CYFRA 21-1 was the most sensitive tumor marker and showed the most powerful diagnostic performance among the five SC tumor markers. NSE and CA 72-4 are significantly related to lymph node involvement, metastasis or stage. Further evaluations are warranted to clarify the clinical usefulness and prognostic prediction of these markers in SC.

• Journal of Pharmaceutical Investigation
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• v.35 no.5
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• pp.323-328
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• 2005

The purpose of the present study was to evaluate the bioequivalence of two torasemide tablets, Torem tablet (Roche Korea Co., Ltd., Korea, reference drug) and Boryung Torsemide tablet (Boryung Pharmaceutical Co., Ltd., Korea, test drug), according to the guidelines of Korea Food and Drug Administration (KFDA). After adding an internal standard (furosemide) to human serum, serum samples were extracted using 5 mL of ethyl acetate. Compounds were analyzed by reverse-phase HPLC method with UV detection. This method showed linear response over the concentration range of 0.05 ug/mL with correlation coefficient of 0.999. The lower limit of quantitation using 0.5 mL of serum was 0.05 ug/mL which was sensitive enough for pharmacokinetic studies. Twenty-eight healthy male Korean volunteers received each medicine at the torasemide dose of 20 mg in a $2{\times}2$ crossover study. There was a one-week washout period between the doses. Serum concentrations of torasemide were monitored by an HPLC-UV for over a period of 12 hr after the administration. $AUC_{t}$(the area under the serum concentration-time curve from time zero to 12 hr) was calculated by the linear trapezoidal rule method. $C_{max}$ (maximum serum drug concentration) and $T_{max}$ (time to reach $C_{max}$) were compiled from the serum concentration-time data. Analysis of variance was carried out using logarithmically transformed $AUC_{t}$ and $C_{max}$. No significant sequence effect was found for all of the bioavailability parameters indicating that the crossover design was properly performed. The 90% confidence intervals of the $AUC_{t}$ ratio and the $C_{max}$ ratio for Boryung Torsemide/Torem were log 0.97-10g 1.03 and log 0.93log 1.12, respectively. These values were within the acceptable bioequivalence intervals of log 0.80-log 1.25. Thus, the criteria of the KFDA guidelines for the bioequivalence was satisfied, indicating Boryung Torsemide tablet and Torem tablet are bioequivalent.

• Journal of Astronomy and Space Sciences
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• v.33 no.2
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• pp.127-135
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• 2016

Inactive space objects are usually rotating and tumbling as a result of internal or external forces. KOREASAT 1 has been inactive since 2005, and its drift trajectory has been monitored with the optical wide-field patrol network (OWL-Net). However, a quantitative analysis of KOREASAT 1 in regard to the attitude evolution has never been performed. Here, two optical tracking systems were used to acquire raw measurements to analyze the rotation period of two inactive satellites. During the optical campaign in 2013, KOREASAT 1 was observed by a 0.6 m class optical telescope operated by the Korea Astronomy and Space Science Institute (KASI). The rotation period of KOREASAT 1 was analyzed with the light curves from the photometry results. The rotation periods of the low Earth orbit (LEO) satellite ASTRO-H after break-up were detected by OWL-Net on April 7, 2016. We analyzed the magnitude variation of each satellite by differential photometry and made comparisons with the star catalog. The illumination effect caused by the phase angle between the Sun and the target satellite was corrected with the system tool kit (STK) and two line element (TLE) technique. Finally, we determined the rotation period of two inactive satellites on LEO and geostationary Earth orbit (GEO) with light curves from the photometry. The main rotation periods were determined to be 5.2 sec for ASTRO-H and 74 sec for KOREASAT 1.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.5
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• pp.252-261
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• 2017

This study examined the effect of heat treatment on the microstructure and mechanical properties of J55 line pipe steel. The experiments were carried out at under the following various conditions: austenization temperature($880^{\circ}C$, $910^{\circ}C$, $940^{\circ}C$), cooling methods(water quenching, oil quenching) and tempering temperature(none, $550^{\circ}C$, $650^{\circ}C$). The phase diagram and CCT curve were simulated based on the chemical composition of J55 steel to predict the microstructures. In the results, A1, A3 temperature decreased. As the austenization temperature increased, existing austenite grains grew exponentially which seriously degraded their mechanical properties. Various microstructures, including martensite, bainite, ferrite, and pearlite, developed in accordance with the heat treatments and were closely correlated with hardness, tensile strength and toughness. Martensite was formed after water quenching, but bainite and ferrite appeared after oil quenching. FeC precipitation formed and coarsened during tempering, which improved their toughness.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.7
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• pp.990-995
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• 2016

In the present study, reversed-phase HPLC was utilized to quantify the ${\beta}$-carotene content of 22 kinds of raw and blanched vegetables consumed in Korea. In addition, true retention (TR) of ${\beta}$-carotene in samples was obtained. For quantification of ${\beta}$-carotene, external standard curve was obtained with limit of detection and limit of quantitation. The ${\beta}$-carotene contents in 22 raw vegetables ranged from 6.29 (bellflower root) to $7,050.73{\mu}g/100g$ (spinach, field culture). After blanching, ${\beta}$-carotene contents of 13 vegetables increased up to 103.05% while nine vegetables resulted in reduced content, ranging from -2.17 to -29.16%. However, even though increased ${\beta}$-carotene content was observed after blanching, TR of some vegetables was lower than 100% due to their weight reduction. The highest TR of ${\beta}$-carotene was found from blanched cabbage (164.46%) while the lowest TR was found from Turcz (Gomchwi) at 59.35%. TR is an effective method to evaluate retention of nutrients in cooked foods, considering changes of nutrient content and weight.

• Journal of the Korean Society of Groundwater Environment
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• v.5 no.3
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• pp.155-161
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• 1998

Retardation effect of heavy metals in soils caused by adsorption onto the surfaces of solids particles is well known phenomenon. In this study, we investigated the retardation effect on the mobility of a Zn in a sandy soil by conducting batch and column tests. The column test consisted of monitoring the concentrations of effluent versus time known as a breakthrough curve (BTC). We used NaCl and ZnCl$_2$ solutions with the concentration of 10 g/L as a tracer, and injected them respectively into the inlet boundary of the soil sample as a square pulse type, and monitored the effluent concentrations at the exit boundary under a steady state condition using an EC-meter and ICP-AES. The batch test was conducted based on the standard procedure of equilibrating fine fractions collected from the soil with various initial ZnCl$_2$ concentrations, and analysis of Zn ions in the equilibrated solutions using ICP-AES. The results of column test showed that i) the peak concentration of ZnCl$_2$analyzed by ICP was far less than that of either NaCl or bulk electrical conductivity and ⅱ) travel times of peak concentrations for two tracers were more less identical. The relatively low concentration of Zn can be explained by ion exchange between Zn and other cations, and possible precipitation of Zn in the form of Zn(OH)$_2$due to high pH range (7.0∼7.9) of the effluent. The identical result of travel times of peak concentrations indicates that the retardation effect is not present in the soil. The only way to describe the prominent decrease of Zn ion was to introduce decay or sink coefficient in the CDE model to account for irreversible decrease of Zn ions in the aqueous phase.

• Food Science of Animal Resources
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• v.33 no.6
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• pp.772-780
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• 2013

The aim of this study was to investigate the effect of season and location on activities of enzyme produced by psychrotrophic bacteria isolated from raw milk located in Kyunggi region of South Korea. Agar diffusion and colorimetric methods were used for the lipase and protease activities of psychrotrophic bacteria. Intensities of dark blue and transparent ring around colony were compared for activity measurement. Nutrient agar with 1% skim milk added was employed for measuing protease activity. 14 strains of Arthrobacter russicus with lipase activity and 19 strains of Chryserobacterium shigense with protease activities were found to be present. It was found that Acinetobacter genomospecies 10 (match %: 99.90) isolated from B region in fall was the most lipolytic species, whereas Serratia liquefaciens (match %: 99.39) isolated from the same region in spring was the most proteolytic species. Growth curve of Acinetobacte and Serratia liquefaciens was a typical sigmoidal form. Lipase activity increased with incubation time, but its activity began to drop at stationary to motality phase. Optimum condition for incubation time, pH and temperature for extracellular lipase from Acinetobacter genomospecies 10 (match %: 99.90) was 12 h, 8.5, and $45^{\circ}C$, respectively. Extracellular protease from Serratia liquefaciens (match %:99.39) had the same optimum incubation time and pH as extracellular lipase, but optimum temperature was $35^{\circ}C$.

• Korean Journal of Environmental Agriculture
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• v.33 no.3
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• pp.205-212
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• 2014

BACKGROUND: This study focused on the contents of flavonoid compounds in vegetables. Generally vegetables have contributed to a healthy diet, arisen from contains a large amount of fiber and functional ingredients. And flavonoid compounds are one of major functional components in the vegetables. currently research of flavonoid contents does not enough, specially in the part of homegrown vegetable. METHODS AND RESULTS: Vegetable samples were purchased in domestic market. Sample extraction by methanol, distilled water, and formic acid based solvent. Also same solvent used for mobile phase in UPLC. Eleven types of flavonoid compounds were analyzed with same kind of external standard and one kind of internal standard (galangin) for quantification. Standard calibration curve presented linearity with the correlation coefficient $R^2$ > 0.98, analysed from 1 to 50 ppm concentration. The quantitative value and multivariate analysis results were derived from the Excel and SIMCA-P11. Overall, onion has largest amount(916.5 mg/100 g) of flavonoid and also other vegetables have has significant amount[Mugwort: 138.8, Galic stem:123.6 mg/100 g etc.] of flavonoid compounds. Edible portion of vegetables per share for simulating by SIMCA-P11, root vegetables has had difference with other vegetables according to distributions and amounts of flavonoid compounds. CONCLUSION: Optionally, the results from this experiment can use to select the material for flavonoid researches. And based on these results, if this experiment will be continuously complemented, and performed, could used in various fields.

• Analytical Science and Technology
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• v.24 no.3
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• pp.225-230
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• 2011

Anatoxin-a is a cyanobacterial neurotoxin with a high toxicity produced by Anabaena, Aphanizomenon and Oscillatoria. Water bloom, formed by Anabaena has been occurring frequently in Lake Yeongchun. It is need to develop a sensitive method for determination of anatoxin-a to control potential hazard in raw water resources. In this study, we developed a highly sensitive analytical method of anatoxin-a using solid phase extraction (SPE) and high performance liquid chromatography (HPLC) with fluorescence detection. Anatoxin-a was converted into a highly fluorescent derivative using 4-fuoro-7-nitro-2,1,3-benzoxadiazole (NBF-F). The method was evaluated in terms of linearity of calibration curve, recovery and repeatability, and the adequate values were obtained. The method detection limit was $0.034\;{\mu}g/g$ and $0.022\;{\mu}g/L$ for algal and water samples, respectively. The concentrations of anatoxin-a were measured in algal and water samples from Lake Andong, Yeongchun and Daechung and ranged from $0.135\;{\mu}g/g$ to $10.979\;{\mu}g/g$ in algal samples and not detected in water samples.