• Journal of Korean Society for Atmospheric Environment
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• v.28 no.4
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• pp.374-383
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• 2012

In this study, we have observed the airborne radon levels in the subway cabins before and after platform screen doors (PSD) installation. The measurements have been conducted at Seoul metropolitan subway lines in 2008, 2009 and 2010. The mean concentration of the radon inside subway cabins were increased by approximately 53% from $20.1Bq/m^3$ to $30.8Bq/m^3$ by installing PSD. After PSD installation, measured values for the different lines were rather different, and varied between 8.2 and $76.5Bq/m^3$. And mean radon concentrations were in the decreasing order for subway lines 5, 6, 7, 8, 3, 4, 2, 9 and 1. It was also found that the indoor radon concentrations in the subway cabins were highly dependent on the management approach of a ventilation system at the subway stations. By assuming an average of $720\;h\;year^{-1}$ and $2,880\;h\;year^{-1}$ spent in subway cabin, effective doses to passengers and employee were estimated. The expected annual effective dose, in case of an equilibrium factor of 0.4, were $0.07mSv\;y^{-1}$ and $0.26mSv\;y^{-1}$, respectively.

• Korean Journal of Veterinary Service
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• v.28 no.1
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• pp.71-79
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• 2005

In this study, a total of 2,119 samples was taken from bovine feces and carcass from March 2002 to December 2003. And those were examined for the presence of enterohemorrhagic E coli O157:H7. The properties of the isolates were characterized for biochemical features, serotypes, virulence genes and antimicrobial susceptibility. Forty five strains($3.7\%$) of E coli O157:H7 were isolated from 1,208 fecal samples and were not detected in carcass using immunomagnetic separation technique and selective media. In multiplex PCR using stx1, stx2, eaeA and hlyA primers, the amplified bands at 180 bp, 255bp, 384bp and 534bp were observed, respectively. In antimicrobial susceptibility test, all isolates were susceptible to amoxicillin/clavulanic acid and cefazolin. The isolates were most resistant to sulfisoxazole($24.4\%$), followed by streptomycin($22.2\%$), tetracycline($20.0\%$). Eight strains($17.8\%$) of 45 isolates showed the multi-resistant patterns with over 3 drugs.

• Korean Journal of Pharmacognosy
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• v.45 no.1
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• pp.41-47
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• 2014

This study was conducted to investigate the content of foreign mineral materials and heavy metals (Pb, As, Cd, Hg) contained in commercial herbal medicines (1504 samples) classified by parts used, and the effect of removing heavy metals by washing treatment (take 50 g of the sample and put 1000 ml of distilled water, shake it gentle by hand for 1 min). The 5% trimmed means of acid-insoluble ash value (%) were as follows; above ground parts (0.76) and underground parts (0.52). Those of the total amount of individual heavy metals value (mg/kg) were as follows; caulis (1.33), flos (1.23), herba (0.91), cortex (0.76), rhizoma (0.73), radix (0.67), semen (0.44) and fructus (0.39). Acid-insoluble ash content was correlated with Pb in herbal medicines of underground parts (r=0.446) (p<0.01). After washing, the removal rate of heavy metals contained in 6 radix herbal medicines shows 33-13% respectively.

• Korean Journal of Veterinary Service
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• v.30 no.3
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• pp.353-362
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• 2007

A total of 1,354 samples was collected from bovine and porcine carcass from January 2005 to December 2006 in a slaughter house. Twenty five strains(1.8%) of Listeria monocytogenes were isolated from 1,354 samples using selective media. Ten(1.4%) L monocytogenes were isolated from the 677 of bovine carcasses, and 15(2.2%) were isolated from the 677 of porcine carcasses. Among 15 L mono-cytogenes from porcine, 11 siolates were serovars 1/2c, followed by 1/2b (3 strains, 20.0%) and 1/2a(1 strain) Out of 10 bovine samples, positive cases in 1/2a were 9 strains (90.0%), 1/2b were 1 strains(10.0%). PCR primers were selected to amplify a 520-base pair(bp) DNA fragment from the listeolysin O gene (hlyA) of L mono-cytogenes. A 520-bp product was detected in PCR with DNA from L monocytogenes, but not from the other Listeria species tested. A total of 25 L monocytogenes strains were analysed by PFGE after digestion with Apa I. PFGE analysis of genomic DNA showed the $14{\sim}18$ fragments ranging in size from 30 to 550 kb, resulting in 14 patterns.

• Particle and aerosol research
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• v.17 no.4
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• pp.115-123
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• 2021

The emission gas from meat grilled restaurants has unpleasant odor and sticky particulate matters (PM) in form of oil mist. This affects the residents living nearby. In oder to decrease the odor and PM, electrostatic precipitators (ESP) were installed at several restaurants by support of Seoul metropolitan government and emission characteristics of PM and odor were investigated. The removal efficiency of odor and PM at before- and after-ESP was that total hydrocarbon (THC), NH₃, H₂S, acetaldehyde, butyraldehyde were not much decreased. Total suspended particles (TSP) emitted from the vent was below the value of 7 mg/m³ regardless of the concentration of before-ESP and removal efficiency was in the range of 64 ~ 86%. The ratio of PM_1.0 to PM₁₀ of emission gas was over 0.9. So it was revealed that most PM of emission gas was PM1.0. The PM concentration in the air of the street near the vent was higher than another street due to the emission gas and the PM of indoor air of restaurant grilling meats was measured very high compared to outdoor air. So it needs more powerful ventilation of indoor air.

• Journal of Wellbeing Management and Applied Psychology
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• v.5 no.4
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• pp.19-31
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• 2022

Purpose: This study was conducted to identify indoor air quality in various living spaces using sensors that can measure noise, vibration, fine dust, and odor in real time and to propose optimal indoor air quality maintenance management using Internet of Things(IoT). Research design, data and methodology: Using real-time sensors to monitor physical factors and environmental air pollutants that affect the comfort of the residential environment, Noise, Vibration, Atmospheric Pressure, Blue Light, Formaldehyde, Hydrogen Sulfide, Illumination, Temperature, Ozone, PM10, Aldehyde, Amine, LVOCs and TVOCs were measured. It were measured every 1 seconds from 4 offices and 4 stores on a small scale from November 2018 to January 2019. Results: The difference between illuminance and blue light for each measuring point was found to depend on lighting time, and the ratio of blue light in total illumination was 0.358 ~ 0.393. Formaldehyde and hydrogen sulphide were found to be higher than those that temporarily attract people in an indoor office space that is constantly active, requiring office air ventilation. The noise was found to be 50dB higher than the office WHO recommendation noise level of 35 ~ 40dB. The most important factors for indoor environmental quality were temperature> humidity> illumination> blue light in turn. Conclusions: Various factors that determine the comfort of indoor living space can be measured with real-time sensors. Further, it is judged that the use of IoT can help maintain indoor air quality comfortably.

• Korean Journal of Head & Neck Oncology
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• v.32 no.1
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• pp.29-32
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• 2016

Venous malformation with phleboliths is uncommon cause of unilateral parotid swelling. The clinical and radiographic appearance of venous malformation with phleboliths may masquerade as sialolithiasis. A 49-year-old female complained about unilateral parotid swelling for 6 years. Preoperative evaluation including computed tomography and sonography showed the suspicion of venous malformation with phleboliths. Superficial parotidectomy was performed. Pathological examination confirmed that the mass was venous malformation with phleboliths combined with sialolith in the parotid gland. We present the case of unilateral parotid swelling caused by a venous malformation combined with sialolithiasis.

• The Korean Journal of Pesticide Science
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• v.18 no.4
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• pp.269-277
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• 2014

The multiclass pesticide multiresidue method for the simultaneous determination of diflubenzuron in agricultural products was conducted by using HPLC-UVD. The method was validated through the guidelines of linearity, specificity, limit of detection (LOD), limit of quantification (LOQ), accuracy and precision with pesticide-free spinach, Korean cabbage, eggplant, squash, sweet pepper, cucumber, Korean melon. The calibration curve of diflubenzuron was linear over the concentration range of 0.05-5 mg/kg with correlation coefficient of above 0.99999. The limit of detection and quantification was 0.008 and 0.02 mg/kg. Mean recoveries of diflubenzuron for each sample were 77.5-105.6%. Relative standard deviation (RSD) in recoveries were all less than 20%. The intra-day and inter-day precision (RSD) were 0.4-1.9% and 0.7-1.9%, respectively. The result of validation indicated that this method was accurate and rapid assay.

• Proceedings of the PSK Conference
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• 2000.10a
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• pp.196.1-196.1
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• 2000

• Journal of Food Hygiene and Safety
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• v.32 no.1
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• pp.35-41
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• 2017

To determine the contents of sodium and potassium in side dishes, 92 samples from 22 different kinds of side dishes that can be classified into 3 groups were collected in Seoul area and analysed using ICP-OES. The highest sodium content was detected in pepper doenjang muchim, while potassium content was the highest in kong jorim. When comparing the content of sodium and potassium in 3 groups, namely namul, muchim, and jorim, the sodium content of namul group was significantly different from those of jorim and muchim (p-value < 0.05). Sodium intake per serving size was the highest in parae muchim among the samples as estimated to 20.2% of WHO recommendation that is 2,000 mg/day. The amount of sodium by simultaneously intake of soybean sprouts namul, anchovy jorim and parae muchim per one serving size was estimated to 1,000 mg. The potassim/sodium ratios of spinach namul and kong jorim were 1.70 and 0.81, respectively, while that of bracken namul was very low as about 0.1. Food-borne pathogens were not detected out of 92 side dishes.