• Korean Journal of Optics and Photonics
• /
• v.2 no.3
• /
• pp.115-120
• /
• 1991

The effect of ZnS buffer layer on the brightness and luminous efficiency of SrS : Ce, Cl thin film EL device is investigated. The driving voltage is 210V for the cell with ZnS buffer layer, but 220V without ZnS buffer layer. The frequency range is 500 Hz-20 kHz. The. brightness is proportional to the product of the frequency and the transferred charge density within measured range. The luminous efficiency is independent on the frequency and/or driving voltage. By using the ZnS buffer layer, the luminescence characteristics of active layer is improved. The experimental data shows 0.12 Im/W of the luminous efficiency for the device with ZnS buffer layer, but 0.061m/W without ZnS buffer layer.

• Solar Energy
• /
• v.17 no.2
• /
• pp.55-66
• /
• 1997

The structural and optoelectronic properties of polycrystalline CdS films up to several microns in thickness, fabricated by three different methods, are compared to one another for the purpose of preparing CdTe/CdS solar cells. All films were deposited on an indium tin oxide on glass substrate. The three methods are: 1) alternated spraying of cation and anion solution at room temperature; 2) spray pyrolysis with substrate temperature up to $500^{\circ}C$; 3) chemical bath deposition (CBD). Deposited films were thermally treated in various ways. All films showed a well-developed wurtzite structure. Films grown by the alternated-spray method and the chemical bath method consist of randomly-oriented crystallites with dimensions <0.5 microns. Annealing at $400^{\circ}C$ increases the crystallite size slightly. Films which were grown by pyrolysis at substrate temperatures from $400^{\circ}C\;to\;500^{\cir\c}C$ were oriented in the <002> direction. For growth by pyrolysis at $500^{\circ}C$, the surface is rough on a lateral scale of 0.1 to 0.3 microns. The optical band gap and defect states are investigated by optical absorption, photoluminescene, Raman, and photothermal deflection spectroscopies.

• Korean Journal of Poultry Science
• /
• v.16 no.2
• /
• pp.73-81
• /
• 1989

This study was conducted to estimate heritabilities, genetic and phenotypic correlations on economic traits in layers. The data analysis were the records of 351 pullets in S. C. W. Leghorn and 326 pullets in R. I. Red from March 1, 1980 to July 31.1981. The results obtained are summarized as follows：1 The average body weights at the first egg, 300 and 500 days of age were 1, 409, 1, 602 and 1, 709g S. C. W. Leghorn, and 1, 965, 2, 305, and 2, 479g in the R. I. Red, respectively. The age at first egg of the S. C. W, Leghorn and R. I. Red were 156 days and 163 days, respectively. The number of egg produced by the S. C. W. Leghorn and R. I. Red to 300 days and 500 days of age were 101.18, 214.39, and 101.05, 214.93, respectively. The egg weight at first egg, 300 and 500 days of age were 41.93, 57.65 and 60.33g in the S. C. W. Leghorn and 41.52, 57.62 and 60.57g in the R. I. Red, respectively. 2. The heritability estimates based on the variance of sire and dam components were 0.402-0.612 and 0.275-0.458 in the S. C. W. Leghorn, 0.309-0.523 and 0.134-0.380 in R. I. Red for body weight； 0.167 and 0.139 in the 5. C. W. Leghorn, 0.169 and 0.095 in the R.1. Red for age at first egg：0.214-0.139 and 0.336-0.341 in S. C. W Leghorn, 0.137-0.259 and 0.024-0.102 in the R. I. Red for number of egg production； 0.537-0.769 and 0.374-0.686 in the S. C. W. Leghorn, 0.519-0.631 and 0.116-0.365 in the R. I. Red for egg weight, respectively. 3. The genetic correlation coefficients of economic traits were as follows： In the S. C. W. Leghorn and R. I. Red , the coefficients between body weights and age at the first egg, 0.328-0.426 and 0.186-0.244：between body weights and number of egg production, -0.666--0.498 and -0.452--0.073：between body weight and egg weight, 0.384-0.774 and 0.126-0.612； between age at first egg and number of egg production, -0.639--0.452 and -0.754--0.320； between age at first egg and egg weight, 0.475-0.705 and 0.021-0.605； between number of egg production and egg weight, -0.623--0.355 and -0.861--0.327, respectively.

• Korean Chemical Engineering Research
• /
• v.43 no.2
• /
• pp.318-323
• /
• 2005

Supercritical water oxidation (SCWO, P>221 bar, T>$374^{\circ}C$) is a promising method for the decomposition of refractory organic compounds. In this study, the SCWO of Ethylenediaminetetraacetic acid (EDTA) was carried out in a tubular-type continusous reactor system with an $H_2O_2$ oxidant at $387-500^{\circ}C$, 250 bar and residence time (RT) of 15.9-88.9 s. The decomposition efficiencies increased with increasing temperature and oxidant amount, while it was inversely proportional to feed flow rate. The decomposition efficiency of 99.6% was obtained at $500^{\circ}C$, 250 bar, oxidant amount of 400% and residence time of 40.1 s. The effect of temperature on the decomposition efficiency was more significant than that of oxidant amount. In the case of the decomposition efficiency of 5,000 mg/L of EDTA (3,063 mg/L as $COD_{Cr}$), the decompostion of 99% or higher was obtained at the condition of over 40.1 s (RT) and 200 stoichiometric % of $H_2O_2$ in the supercritical water of $500^{\circ}C$ and 250 bar.

• Journal of Practical Agriculture & Fisheries Research
• /
• v.22 no.2
• /
• pp.5-15
• /
• 2020

To extend the shelf life of draft makgeolli, UV irradiation and high hydrostatic pressure were conducted. UV irradiation did not reduce the total cell number in makgeolli, but high hydrostatic pressure treated drastically decreased. The number of viable cells in makgeolli was 2.2-5.8 × 10⁷ CFU/mL, but when treated with 300 MPa pressure for 1 minute, it decreased to 1.4-10 × 10³ CFU/mL, with 400 MPa to 4-68 CFU/mL, and with 500 MPa to under 40 CFU/mL. Yeast died at 400 MPa pressure, but Bacillus amyloliquefaciens and Rummeliibacillus stabekisii survived at 500 MPa pressure. The makgeolli treated with 400 and 500 MPa pressure did not increase the number of cells even when stored at room temperature (25℃) for 30 days, and changes in alcohol, acidity, and amino acid vlaue were also suppressed. However, when stored for more than 30 days at room temperature, the acidity and amino acid levels of makgeolli increased, making it difficult to drink. At low temperature (4℃) storage, the quality change of makgeolli was suppressed until 70 days of storage, so it had a taste similar to that of fresh makgeolli.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.31 no.5
• /
• pp.893-898
• /
• 2002

To examine the antioxidant activity of grape seed ethanol extract, the antioxidative index (AI) by the active oxygen method (AOM) and peroxide value (POV) of linoleic acids containing the extract at levels of 100, 500, 1000 ppm was measured during storage at 6$0^{\circ}C$ for 12 days. When comparing with BHT, the extract at levels of 500 ppm showed similar or better antioxidant activity (AI: 2.25, POV: 57 meq/kg oil) than that (AI: 1.21, POV:58 meq/kg oil ) of BHT at 200 ppm level. The mixture of 500 ppm of the extract and 500 ppm of ascorbic acid showed intense synergistic antioxidant activity (AI: 6.21, POV: 14 meq/kg oil) compared with using 1000 ppm of the extract only (AI: 3.39, POV 43 meq/kg oil). Also to determine the feasibility of using the extract for natural antioxidant, the oxidative stability of roasted peanut and Ramyon was investigated by measuring the POV of crude oils from the samples stored at 60"C for 18 days. The oxidative stability of roasted peanut and Ramyon seemed to be enhanced by treatment with the extract at level of 1000 ppm, especially with the 1 : 1 mixture of extract and ascorbic acid. This study suggested that grape seed ethanol extract could be used as the natural antioxidant for the improvement of overall oxidation stability of fat containing foods.oods.

• Journal of radiological science and technology
• /
• v.27 no.4
• /
• pp.43-48
• /
• 2004

The purpose of this study is to measure cardiothoracic ratio and to report the opinions on it, targeting 500 persons who were conducted simple chest radiography, in terms of clinical symptom, by visiting a medical examination center for S university hospital. As to the general characteristic of 500 research targets, it comprised 263 persons (52%) for males and 237 persons (48%), and the average age is 49.4. Out of 500 persons, it showed 125 persons (25%) in their thirties, 125 persons (25%) in their forties, 125 persons (25%) in their fifties, and 125 persons (25%) in their sixties. 1. In terms of the wholly 500 targets, the average value of cardiothoracic ratio was 0.48, and the average cardiothoracic ratio showed 0.45 in their thirties, 0.46 in their forties, 0.50 in their fifties, and 0.53 in their sixties. 2. The minimum value of cardiothoracic ratio was 0.33, and its maximum value was 0.70, and it showed 319 persons (63.8%) as to a case lower than 0.5, which is a normal value, and 181 persons (36.2%) as to a case more than 0.5, which is a normal value. 3. Among 181 persons who showed cardiothoracic ratio higher than normality, it showed 17 persons (9.4%) in their thirties, 22 persons (12%) in their forties, 54 persons (30%) in their fifties, and 88 persons (49%) in their sixties. 4. The average for the internal diameter (ID) of thorax was 141.8 mm, 229.6 mm at the minimum, and 353.5 mm at the maximum. 5. The average for the maximum transverse diameter of right side of the heart (MRD) was 48.0 mm, 4.95 mm at the minimum, and 84.5 mm at the maximum. The average for the maximum transverse diameter of left side of the heart (MLD) was 93.5 mm, 56.7 mm at the minimum, and 138.5 mm at the maximum. 6. The average for TD (MRD+MLD) of the heart was 292.6 mm, 96.6 mm at the minimum, and 199.2 mm at the maximum. 7. The average of cardiothoracic ratio (MRD+MLD/ID) was 0.48, 0.33 at the minimum, and 0.70 at the maximum.

• Journal of the Korean Society of Food Culture
• /
• v.20 no.5
• /
• pp.603-607
• /
• 2005

Fourteen phenolic compounds(benzoic acid, p-hydroxybenzoic acid, protocatechuic acid, vanillic acid, syringic acid, gallic acid, caffeic acid, ferulic acid, (+)-catechin, quercetin, rutin, catechol, chlorogenic acid and L-ascorbic acid) were examined for their effects on the anticarigenic activity. Among tested samples, catechol was significantly inhibited the S. mutans, exhibiting an clear zone 18.5-19.5mm by 10 mg/disc level. The minimal inhibition concentration(MIC) of the phenolic compounds for Streptococcus mutans, M1 and M2 strain were determined as 2,000 ppm, whereas catechol was 1,000 ppm. The activity of glucosyltransferase(GTase) was significantly inhibited by catechol, at 10 ppm(58.7%), 50 ppm(60.7%) and 100 ppm(88.4%) and 500 ppm(89.6%), respectively. Among them, catechol showed most significant anticariogenic activity as well as inhibition of GTase activity.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.32 no.8
• /
• pp.1214-1220
• /
• 2003

Antimicrobial activity of Rhus javanica (RJ) extract against animal husbandry disease-related bacteria was determined by a paper disc method. The RJ extracts showed a significant antimicrobial activity against Gram positive (+) bacteria and especially the activity was most potent against L. monocytogenes and S. epidermidis. Minimum inhibitory concentrations (MIC) of the MeOH and EtOH extracts of RJ were in the range of 0.8 ∼ 16 mg/mL and 0.8 ∼ 10 mg/mL, respectively. Furthermore, among five solvent fractions (n-hexane, CHC1$_3$, EtOAc, n-BuOH and $H_2O$ frs.) from MeOH extract of RJ, the EtOAc fr. exhibited the most significant antimicrobial activity The antimicrobial activities of RJ extracts against most microbial strains were unstable by either heat treatment or acid treatment. The inhibitory effect of RJ extracts on microbial cell growth was further examined by the addition of 0, 100, 300, and 500 ppm of RJ extracts into growth medium. The growth of gram positive (+) bacteria, S. aureus, S. epidermidis and L. monocytogenes was inhibited for 72 hours when at least 300 ppm of RJ extracts added, but the growth of gram negative (-) bacteria was only inhibited when at least 500 ppm of RJ extracts were added. Taken together, tile antimicrobial activities of RJ extracts were more effective against gram positive (+) bacteria compared to those against gram negative (-) bacteria.

• Proceedings of the Korean Nuclear Society Conference
• /
• 2005.05a
• /
• pp.499-500
• /
• 2005