• 한국환경과학회지
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• 제14권1호
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• pp.61-69
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• 2005

Adsorption characteristics of toluene vapor, which is one of important source of volatile organic compounds (VOCs), by activated carbon were investigated using a fixed bed adsorption column. The operating parameters such as breakthrough curve, adsorption capacity, mass transfer zone (MTZ), and length of unused bed (LUB) were studied. The experimental results showed that the breakthrough time decreased with increasing inlet toluene concentration and gas flow rate. MTZ and LUB increased with the increase of inlet concentration, gas flow rate, and particle size of activated carbon. The adsorption capacity increased with the increase of inlet toluene concentration, while it decreased with increasing particle size. However, it was kept at constant value regardless of the increase of gas flow rate. Adsorption isotherm of toluene vapor could be represented by the Freundlich adsorption equation fairly well. From the adsorption experiments using some VOC gases such as toluene, xylene, butyl acetate. butanol and acetone, it was also found that the adsorption capacity was higher in the case of gas with higher boiling point and lower vapor pressure.

• 한국환경과학회지
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• 제18권3호
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• pp.345-353
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• 2009

The purpose of this study is to examine the health of beauty salon workers through the utilization of questionnaires concerning the extent of exposure to organic solvents found in the air of some beauty salons and any resultant symptoms in employees. The subjects were 36 employees from 10 beauty salons who agreed to participate in this study. The degree of exposure to organic solvents in the air of beauty salons was measured from September 1, 2008 to September 30, 2008. A survey of symptoms that occurred due to exposure to these solvents was also performed. The results were as follows: questionnaires were collected and analyzed from a total of 36 subjects. Of these, 28(77.8%) were female and 8(22.2%) were male. The mean age was 29.08. The mean working period was 7.13 years. Sixteen subjects attended programs at universities while 11 went to beauty schools for vocational education. When testing the concentration of organic solvents in the air of beauty salons, the highest value found was Isopropyl alcohol 511.85 ppb followed by butyl acetate, toluene, acetone, xylene, ethyl benzene, styrene, and chlorobenzene. A logistic regression analysis was performed as follows: the point of each factor was the dependent variable while sex, age, drinking, smoking, educational level, work experience, hairdresser's license, and organic solvents were the independent variables. Statistically significant difference (p<0.05) was shown in the hairdresser's license among Factor 1 and in Xylene among Factor 2; however, difference was not shown in the other variables.

• Journal of Preventive Medicine and Public Health
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• 제47권3호
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• pp.169-176
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• 2014

Objectives: This study aimed to evaluate occupational symptoms and chemical exposures of nail salon technicians. Methods: Work-related symptoms of nail salon technicians in Daegu City were surveyed using a researcher-administered questionnaire, and responses were compared to those of non-exposed office workers as controls. Personal exposure level of airborne volatile organic compounds was also monitored using passive samplers. Results: A total of 159 subjects in 120 salons were interviewed. Average work-shift concentrations of 13 chemicals were measured for 50 workers from 30 salons using personal passive samplers. The most frequently reported respiratory or neurologic symptoms by nail shop technicians compared to controls were nose irritation (odds ratio [OR], 54.0; confidence interval [CI], 21.6 to 134.8), followed by headache (OR, 9.3; CI, 4.7 to 18), and throat irritation (OR, 4.3; CI, 2.2 to 8.5). For eyes and skin, 92% of respondents complained eye irritation (OR, 13.1; CI, 5.7 to 30.1). In musculoskeletal symptoms, workers reported pain or discomfort in shoulders (OR, 20.3; CI, 7.7 to 54) and neck (OR, 19.7; CI, 8.9 to 43.6). From personal measurements, the proportion of exceeding the Korean Occupational Exposure Limit was the highest for acetone with 64%, followed by toluene (50%), butyl acetate (46%), and methyl methacrylate (12%). However, the service was being provided without a proper ventilation system in most surveyed shops. Conclusions: Based on these findings, it is warranted to have appropriate local exhaust ventilation place to ensure adequate health protection of nail shop technicians as well as customers. At the same time, greater policy interests are warranted in nail care business to protect health of both workers and customers.

• 한국식품영양과학회지
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• 제34권9호
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• pp.1325-1329
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• 2005

유전자발현 조절 수준에서 멜라닌 색소 생합성 억제물질을 탐색하고자 지치 뿌리로부터 유용성 물질을 추출${\cdot}$분획하여 tyrosinase 프로모터를 지닌 B16 mouse melanoma cell에 처리한 결과 그 메탄을 추출물은 $10{\mu}g/mL$의 농도에서 약 $33\%$ 이상의 tyrosinase프로모터 활성 억제효과를 나타내었으며, 세포 활성능이 $100{\mu}g/mL$의 농도에서 약 $108\%$로 매우 안전하였다. 그리고 methylene chloride, ethyl acetate, butyl alcohol, 물 등의 용매 분획물들도 농도에 따라 차이는 있었지만 $100{\mu}g/mL$또는 $500{\mu}g/mL$의 고농도에서 tyro-sinase 프로모터의 활성을 억제하였다 또한, 지치 메탄올 추출물의 농도를 달리하여 3일 동안 처리하였을 때 멜라닌색소의 생성능은 $10{\mu}g/mL$와 $100{\mu}g/mL$의 농도에서 대조군 세포에 비 해 각각 약 $11\%$와 $24\%$로 크게 감소하는 결과를 보여주었다.

• 한국대기환경학회지
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• 제30권5호
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• pp.492-503
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• 2014

In this study, emission characteristics of volatile odorant species released from urine samples were investigated in relation to two key variables: [1] storage conditions before sampling and [2] incubation conditions during sampling. To this end, 20 offensive odorants were quantified by four different analytical systems and then sorted according to seven functional groups. It is indicated that benzene (B), styrene (S), isobutyl alcohol (i-BuAl), butyl acetate (BuAc), butyraldehyde (BA), isovaleraldehyde (IA), and valeraldehyde (VA) did not contribute to urine odor because their concentration levels were measured below detection limits in all samples. On the other hand, emission concentrations of toluene (T), methyl ethyl ketone (MEK), methyl mercaptan ($CH_3SH$), carbon disulfide ($CS_2$), and ammonia ($NH_3$) were generally higher than other compounds. In terms of odor intensity (OI), $CH_3SH$ and $NH_3$ showed the largest OI values in the range of 2~4. According to t-test (storage approach and urine temperature), the results of T, $CS_2$, and $NH_3$ were statistically distinguished from each other in terms of differences in sampling temperature. Likewise, the emissions of certain odorants from urine samples were affected by changes in sample treatment conditions to a degree.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 춘계학술대회 논문집 센서 박막재료 반도체 세라믹
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• pp.111-115
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• 2003

200nm 정도의 두께를 가진 SBT 박막이 liquid delivery MOCVD 공정에 의해 (111) oriented Pt/Ti/$SiO_2$/Si 기판 위에 증착되었다 이 실험에서는 $Sr(TMHD)_2$tetraglyme, $Bi(ph)_3$ 그리고 $Ta(O^iPr)_4$(TMHD)를 출발 물질로 사용하였다. Sr 출발 물질의 열적 안정화를 위해서 adduct로 tetraglyme를 사용하여 실험하였고 유기 용매로는 n-butyl acetate를 사용하였다 Substrate temperature와 reactor pressure는 각각 $570^{\circ}C$와 5Torr로 유지시켰다. 또한 vaporizer의 용도는 $190-200^{\circ}C$, 그리고 delivery line 의 온도는 vaporizer 보다 높게 유지 $(220-230^{\circ}C)$하여 출발 용액을 분당 0.1ml로 50분간 주입하였다. 수송가스로 Ar, 산화제로 $O_2$ 가스를 사용하였다. 제조한 SBT 박막은 $750^{\circ}C$에서 열처리한 후 인가전압 3V와 5V에서 $2P_r$값이 각각 6.47, $8.98{\mu}C/cm^2$이었으며, $2E_c$값은 인가전압 3V와 5V에서 각각 2.05, 2.31V이었다 그리고 $800^{\circ}C$에서는$750^{\circ}C$에서 열처리한 SBT 박막보다 다소 우수한 이력특성을 나타내어 $2P_r$ 값은 인가전압 3V와 5V에서 각각 7.59, $10.18{\mu}C/cm^2$ 이었으며, $2E_c$값은 인가 전압 3V와 5V에서 각각 2.00, 2.21V 이었다.

• Journal of Applied Biological Chemistry
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• 제59권2호
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• pp.155-158
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• 2016

산복사나무(Prunus davidiana) 열매를 실온에서 80% MeOH 수용액으로 추출하고 이 추출물을 EtOAc 분획, n-BuOH 분획, 물 분획으로 나누었다. EtOAc 분획에 대하여 $SiO_2$과 ODS column chromatography를 반복 실시하여 3종의 화합물을 분리 및 정제하였다. NMR, MS, 및 IR data 등을 해석하여, ursolic acid (1), corosolic acid (2), 그리고 ${\alpha}-amyrin$ (3)로 구조동정 하였다.

• 한국환경과학회지
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• 제30권3호
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• pp.219-234
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• 2021

Industrial emissions, mainly from industrial complexes, are important sources of ambient Volatile Organic Compounds (VOCs). Identification of the significant VOC sources from industrial complexes has practical significance for emission reduction. VOC samples were collected from July 2019 to June 2020. A Positive Matrix Factorization (PMF) receptor model was used to evaluate the VOC sources in the area. Four sources were identified by PMF analysis, including coating-1, coating-2, printing, and vehicle exhaust. The coating-1 source was revealed to have the highest contribution (41.5%), followed by coating-2 (23.9%), printing (23.1%), and vehicle exhaust (11.6%). The source showing the highest contribution was coating emissions, originating from the northwest to southwest of the sample site. It also relates to facilities that produce auto parts. The major components of VOC emissions from the coating facilities were toluene, m,p-xylene, ethylbenzene, o-xylene, and butyl acetate. Industrial emissions should be the top priority to meet the relevant control criteria, followed by vehicular emissions. This study provides a strategy for VOC source apportionment from an industrial complex, which is helpful in the development of targeted control strategies.

• 한국산업보건학회지
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• 제32권4호
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• pp.340-349
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• 2022

Objectives: The importance of MSDS is emphasized for communicating hazardous information due to the increase in the types and usage of chemical substances. The purpose of this study is to assess the reliability of MSDS by collecting and examining paint thinners commercially available in South Korea. Methods: Twenty-five paint thinners were purchased at paint stores and the provision of MSDS was checked. Quantitative and qualitative analysis was performed on the chemical constituents of the thinners using GC-MSD and GC-FID. Reliability was evaluated by the MSDS collection rate for the paint thinners and calculating the rate of matching between laboratory analysis results and the contents and composition of chemical constituents given in the MSDS. Results: Unlike a study conducted in 2006, MSDS were provided for all 25 thinners. As a result of qualitative analysis using GC-MSD, 104 chemical substances were detected. The substances with the highest detection rate were identified in the order of toluene, butyl acetate, acetone, xylene, and ethyl benzene. A component matching rate of 41% was found by comparing the differences between the number of substances detected in laboratory testing and the number of substances listed in the MSDS. Benzene, a carcinogen not listed in the MSDS, was detected in two thinners produced by a small company. The detected benzene contents were 0.039 and 0.040%. When benzene is used, it should be strictly handled according to the Industrial Safety and Health Act. However, since it is not listed on the MSDS, it is judged that benzene was not being managed as a carcinogen in the workplaces where it is used. Conclusions: Since the reliability of MSDS, which play an important role in hazard communication, was evaluated to be low, it is necessary to systematically and continuously secure this reliability. In particular, carcinogens should be managed more strictly.

• 대한본초학회지
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• 제28권2호
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• pp.55-60
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• 2013

Objectives : Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by eczematous inflammtion of the skin. The chestnut inner shell extracts (CI) has been used as a cosmetic material for a long time in Korea. However, the precise anti-allergy effects of CI have yet to be clearly elucidated. In this study, we attempted to evaluate the effect of CI on mast cell-mediated allergy inflammation. Methods : To find the anti-allergy and inflammatory effect of CI, we investigated the inhibitory effect of CI on the production of inflammatory mediators using by enzyme-linked immunosorbent assay in phorbol 12-myristate 13-acetate (PMA) plus calcium ionophore (A23187) stimulated-human mast cell (HMC-1). Results : In this study, we found that CI did not show cytotoxic effect at up to 10 ug/ml on HMC-1. CI inhibited the production of tumor necrosis factor (TNF)-${\alpha}$, interleukin (IL)-6 and IL-8 in stimulated HMC-1. Maximal rate of TNF-${\alpha}$, IL-6 and IL-8 inhibition by CI (10 ug/ml) were about 47.6%, 44.1% and 22.5% respectively. In addition, we showed that Fr.3 isolated from n-Butyl alcohol layer of CI attenuated the production of TNF-${\alpha}$, IL-6 and IL-8 in HMC-1. Conclusion : Taken together, the findings of this study provide us with a novel insight action of CI as a potential molecule for use in the treatment of allergic inflammation diseases.