• Korean Journal of Veterinary Service
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• v.20 no.2
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• pp.169-175
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• 1997

This study was carried out to assess the effect of the chlorine treatment into water for processing chicken products in each stage of slaughtering, with a special viewpoint related with reducing the viable number of microorganisms by which the water and the chicken body were contaminated. The mean bacterial number on chicken samples after picking process was log5.37$\pm$0.20~5.84$\pm$0.160CFU/$\textrm{cm}^2$. When assessed by standard plate count method, it was the higher one than any other processing stage in which eviscerating, pinning, packaging, and chilling was followed in order of the mean bacterial number. The coliform bacterial numbers on carcasses after sampling from different processing stages were log2.11$\pm$0.63~2.88$\pm$0.25MPN/$\textrm{cm}^2, which show almost similar numbers in each processing stage. But, after chilling process the number was decreased slightly. The bacterial counts in the water for scalding and chilling showed log3.43 $\pm$ 0.59~5.06$\pm$0.21 and log4.30$\pm$0.21~6.62$\pm$0.33CFU/$m\ell$, respectively. In the coliform counts for the water taken out from the 2nd chilling tank, the number was log1.97$\pm$0.35~2.91$\pm$0.22MPN/$m\ell$ which showed higher than those of the 1st and the 3rd chilling tank water. The effect of chlorination in reducing the bacterial numbers was accepted at the residual chlorine concentration of 1$m\ell$/$\ell$by showing the reduction from $10^8$ to $10^4$CFU level and the numbers were decreased less than 10CFU at the concentration of 5mg/$\ell$, when assessed by viable cell counts. In conclusion, these results suggested that chlorination In chilling water with final concentration of 5mg/$\ell$was strongly recommended to reduce the bacterial numbers on final chicken products.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.5
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• pp.515-525
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• 2007

In this study, various techniques for measurement and analysis of PAHs in the ambient air were verified in order to select a more reliable method. Sampling and analysis of PAHs were done by the EPA TO-13a method. QA/QC of the measurement was conducted to minimize errors in sampling and analyzing processes. The linearity of calibration curve of the PAH standards was good ($R^2{\geq}0.99$). Audit accuracy was evaluated using 5 internal standards of PAHs ($Naphthalene-d_8,\;Acenaphthene-d_{10},\;Phenanthrene-d_{10},\;Chrysene-d_{12},\;Perylene-d_{12}$). Relative standard deviations of the internal standard of the PAHs were ranged from 6.22% for $acenaphthene-d_{10}$ to 8.11% for $chrysene-d_{12}$. To evaluate the surrogate recoveries, two field surrogate standards of PAHs ($fluoranthene-d_{10},\;benzo(a)pyrene-d_{12}$) and two extract surrogate standards of the PAHs ($fluorene-d_{10},\;pyrene-d_{12}$) were spiked into all samples before field sampling and sample extraction, respectively. Recoveries of field the surrogate standards ranged from $80.4{\pm}12.2%$ for $fluoranthene-d_{10}$ to $66.2{\pm}12.8%$ for $benzo(a)pyrene-d_{12}$. Extraction recoveries of the surrogate standards ranged from $70.4{\pm}10.2%$ for $fluorene-d_{10}$ to $77.6{\pm}10.8%$ for $pyrene-d_{10}$. The detection limit of benzo(a)pyrene among 16 PAHs standards for quantitation was 20 pg.

• Journal of Korean Society for Atmospheric Environment
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• v.34 no.5
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• pp.651-658
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• 2018

Particulate matter (PM) emitted from fossil fuel-combustion facilities can be classified as either filterable or condensable PM. The U.S. Environmental Protection Agency (EPA) defined condensable PM as material that is in the phase of vapor at the stack temperature of the sampling location which condenses, reacts upon cooling and dilution in the ambient air to form solid or liquid in a few second after the discharge from the stack. Condensable PM passed through the filter media and it is typically ignored. But condensable PM was defined as a component of primary PM. This study investigates the change of condensable PM according to the variation in the sulfur dioxide of combustion gas. Domestic oil boilers were used as the source of emission ($SO_2$) and the level of $SO_2$ concentration (0, 50, 80, and 120 ppm) was adjusted by diluting general light oil and marine gas oil (MGO) that contains sulfur less than 0.5%. Condensable PM was measured as 2.72, 6.10, 8.38, and $13.34mg/m^3$ when $SO_2$ concentration in combustion gas were 0, 50, 80, and 120 ppm respectively. The condensable PM tended to increase as the concentration of $SO_2$ increased. Some of the gaseous air pollutants emitted from the stack should be considered precursors of condensable PM. The gas phase pollutants which converted into condensable PM should reduced for condensable PM control.

• Journal of the Korean Vacuum Society
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• v.5 no.4
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• pp.284-291
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• 1996

We have implemented a fast pressure control system for the transport chamber of a high vacuum cluster tool for advance semiconductor fabrication and evaluated its performance. To overcome the typically slow response of mass flow controllers, the modified experimental method is used very effectively to optimize the pressure control procedure. We successfully obtained quite fast pressure control by adjusting the starting time and eht tuning constants by the Ziegler-Nichols method. In the transport pressure $10\times 10^{-5}$ torr, actual pressure control starts from 4 sec after an initial gas load of 2.1 sccm. As a result, optimum conditions for the tuning constants are the rise rate of 0.02 torr/sec, the lag time of 0.15 sec, and the sampling period of 0.5 sec. Then the settling time is about 9 sec within about $\pm$0.5% for the referenced value. This settling time is enhanced above 75 percents in comparison with conventional experimental method. To account for the experimental effects observed, a theoretical model was developed. This experimental result has a tendency to fit with the theoretical result of $\omega$=-1.0.

• Biomolecules & Therapeutics
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• v.6 no.3
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• pp.296-302
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• 1998

The bioequivalence of two cyclosporin A products was evaluated in 26 normal male volunteers (age 25 ~33 yr, body weight 56~84 kg) following single oral administration. Test product was a hard capsule containing the granule of cyclosporin A (Chong Kun Dang Corp., Korea) and reference product, Sandimmun", was a soft capsule containing surfactant, oil, alcohol and cyclosporin A (Sandoz, Swiss). Both products contain 100 mg of cyclosporin A. Four capsules of the test and the reference product were administered to the volunteers, respectively, by randomized two period cross-over study (2$\times$2 Latin square method). Average drug concentrations at each sampling time and pharmacokinetic parameters were not significantly different between two products (p>0.05); the area under the concentration-time curve to last sampling time (24 hr) (AU $Co_{24}$) (5034.8$\pm$ 1760.6 vs 4635.4$\pm$ 1158.9 ng . h/ml), maximum plasma concentration ( $C_{max}$) (1002.7$\pm$353.1 vs 980. 4$\pm$ 171.7 ng/71), and mean residence time (MRT) (6.16$\pm$0.81 vs 5.64$\pm$0.50 h). The differences of mean AUC 7-,4,7~, T_ and MRT between the two products (7.93,2.22,16 and 8.39%, respectively) were less than 20% given as a guideline. The power (1-$\beta$) and treatment difference ($\Delta$) for AU $Co_{24}$, $C_{max}$ and MRT were more than 0.8 and less than 0.2, respectively. Although $T_{max}$ of the two products was significantly different each other (p<0.05), $T_{max}$ might be an insignificant parameter because cyclosporin A generally requires long-term administration. From these results, the two products are bioequivalent.alent.t.

• Journal of Korean Society of Forest Science
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• v.60 no.1
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• pp.10-16
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• 1983

This survey was carried out in Schneegattern Forest District which is located 40 km northeast of Salzburg, Austria. The purpose of interpretation with two sampling methods, stratified sampling and unstratified sampling, on B & W infrared photos, with a scale of 1:10,000 was to know coniferous stand volumn and to reduce the cost, Forest stands were classified into 4 groups; those were non-forest, young stands, beech, coniferous stands. Coniferous and beech stands were devided into age classes I (41-80 years), II (above 81 years). After this delineation sample points were designated on the orthophoto map whose data were transferred from the aerial photos. The volumn data were calculated from DBH using relascope in the field and the results were as follows. 1) Coniferous stand volumn per hactare was ($470{\pm}31.9m^3$ 2) The diameter distribution of $C_1$ was binomial, but $C_2$ showed normal distribution. 3) The stratified sampling method was better than unstratified sampling method.

• Journal of Pharmaceutical Investigation
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• v.23 no.1
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• pp.41-49
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• 1993

The bioequivalence of two omeprazole enteric-coated products was evaluated in 16 normal male volunteers (age 26-32 yr, body weight 57-75 kg) following single oral administration. Test product was enteric-coated KD-182 tablet (Chong Kun Dang Corp., Korea) and reference product was $Rosec^{\circledR}$ capsule containing enteric-coated pellets of omeprazole (Yuhan Corp., Korea). Both products contain 20 mg of omeprazole. One tablet or capsule of the test or the reference product was administered to the volunteers, respectively, by randomized two period cross-over study ($2\;{\times}\;2$ Latin square method). Average drug concetrations at each sampling time and pharmacokinetic parameters calculated were not significantly different between two products(p>0.05); the area under the concentrationtime curve to last sampling time (8 hr) $(AUC_{0-8hr})$ $(1946.5{\pm}675.3\;vs\;2018.3{\pm}761.6\;ng{\cdot}hr/ml)$, AUC from time zero to infinite $(AUC_{o-\infty})$ $(2288.6{\pm}1212.8\;vs\;2264.9{\pm}1001.3\;ng{\cdot}hr/ml)$, maximum plasma concentration $(C_{max})$ $(772.5{\pm}283.3\;vs\;925.8{\pm}187.7\;ng/ml)$, time to maximum plasma concentration $(T_{max})$ $(2.38{\pm}1.06\;vs\;2.34{\pm}1.09\;hr)$, apparent elimination rate constant $(k_{\ell})$ $(0.5339{\pm}0.2687\;vs\;0.5769 {\pm}0.2184\;hr^{-I})$, apparent absorption rate constant $(k_a)$ $(1.1536{\pm}0.5278\;vs\;0.9739{\pm}0.9507 hr^{-1})$ and mean residence time (MRT) $(3.13{\pm}0.73\;vs \;3.41{\pm}1.04\;hr)$. The differences of mean $(AUC_{0-8hr})$, $C_{max}$, $T_{max}$ and MRT between the two products (3.69, 19.83, 1.32 and 8.99%, respectively) were less than 20%. The power $(1-{\beta})$ and treatment difference $(\triangle)$ for $AUC_{o-8hr}$ $C_{max}$ and MRT were more than 0.8 and less than 0.2, respectively. Although the power for $T_{max}$ was under 0.8, $T_{max}$ of the two products was not significantly different each other(p>0.05). These results suggest that the bioavailability of KD-182 tablet is not significantly different from that of $Rosec^{\circledR}$ capsule. Therefore, two products are bioequivalent based on the current results.

• Journal of Korean Society for Atmospheric Environment
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• v.16 no.4
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• pp.317-326
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• 2000

Carbonyl compounds have been measured in downtown Seoul for September 1998 using 2-series impinger method. Average concentration (ppbv) of carbonyl compounds were 12.66$\pm$5.77 HCHO, 12.05$\pm$4.86 CH3CHO and 7.92$\pm$2.63 CH3CHCH3 These compounds were the most abundant carbonyl,. They showed maximum concentration during the daytime when photochemical activity was very strong minimum concentration were usually showed during the night and early morning. Comparison of diurnal variation of carbonyl compounds with the concentration of O3, NMHC, CO and meteorological data indicated that primary and secondary sources contributed the observed carbonyl compounds. Photochemical Formation Rate(PFR) of carbonyl compounds dur-ing the sampling periods were 61% HCHO, 85% CH3CHO, 85% CH3CHO, 71% CH3COCH3.

• Particle and aerosol research
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• v.16 no.1
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• pp.19-30
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• 2020

The organic carbon in the ambient particulate matter (PM) is divided into primary organic carbon (POC) and secondary organic carbon (SOC) by their formation way. To regulate PM effectively, the estimation of the amount of POC and SOC separately is one of important consideration. Since SOC cannot be measured directly, previous studies have evaluated determination of SOC by the EC tracer method. The EC tracer method is a method of estimating the SOC value from calculating the POC by determining (OC/EC)pri which is the ratio of the measured values of OC and EC from the primary combustion source. In this study, three different ways were applied to OC and EC concentrations in PM_2.5 measured at Seoul for determining (OC/EC)pri: 1) the minimum value of OC/EC ratio during the measurement period; 2) regression analysis of OC vs. EC to select the lower 5-20% OC/EC ratio; 3) determining the OC/EC ratio which has lowest correlation coefficient value (R²) between EC and SOC which is reported as minimum R squared method (MRS). Each (OC/EC)pri ratio of three ways are 0.35, 1.22, and 1.77, respectively from the 1 hourly data. We compared the (OC/EC)pri ratio from 1hourly data with 24 hourly data and revealed that (OC/EC)pri estimated from 24 hourly data had twice larger than 1hourly data due to the low time resolution of sampling. We finally confirmed that the most appropriate value of (OC/EC)pri is that calculated by a regression analysis of 1 hourly data and estimated SOC amounts at PM_2.5 of the Seoul atmosphere.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.6 no.1
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• pp.97-108
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• 1996

A new type of passive samplers were designed and produced by authors. After evaluating the quality of activated carbon by measuring recovery rate of organic vapors and steadiness of sampling rate, activated carbon with 30 - 35 mesh produced by Company S in Korea was selected. In each passive sampler, an amount of 400 mg of the activated carbon was filled in 25-mm cassette and covered by fixed screen (or wire screen with 100 mesh). In addition to the fixed screen, a wind screen (or wire screen with 300 mesh) was also attached at outer face. The sampling rate of the new Korean passive samplers was estimated Conclusions obtained in the study are as follows. 1. Sampling rates of the newly developed Korean passive samplers were affected by sampling time. For n-hexane, sampling rates of 15- and 60-minute samples were 70.92 and 37.45 ml/min, respectively. Sampling rate of both 200- and 450-minute samples was 25.96 ml/min. It is concluded that, when passive samplers are used for measuring organic vapors, samples be collected longer than 60 minutes. 2. Sampling rate of the passive samplers was also affected by airborne concentration of organic vapors. Lower sampling rates were determined at level of 1/2 threshold limit values (TLVs) recommended by the American Conference of Governmental Industrial Hygienists (ACGIH). It is recommended that sampling rate of the passive samplers be obtained at site by measuring concentrations using both the NIOSH Method and passive samplers simultaneously. 3. When the passive samplers, which collected organic vapors, were exposed to clean air for five hours, there was no significant loss of organic vapors due to reverse diffusion. 4. When samples were stored at room temperature ($21.8{\pm}0.7^{\circ}C$) and refrigerator ($3.8{\pm}0.7^{\circ}C$), there was no significant difference in the accuracy of results. For trichloroethylene and n-hexane, accuracies were within 25 % at both temperatures until seven days. However, poor accuracy exceeding 25 % was indicated in toluene from the first day. It is recommended that samples be stored at freezing temperature below $0^{\circ}C$. 5. Sampling efficiency was significantly affected by direction of the passive samplers. Results of samplers facing wind and down, respectively, were compared. Lower amount of organic vapors were collected when the sampler was oriented down. It is recommended that, when air velocity is low in plants, the passive samplers be oriented to the wind. However, when air velocity is high, the passive samplers be oriented down.