• Journal of the Society of Cosmetic Scientists of Korea
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• v.40 no.2
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• pp.203-214
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• 2014

We measured the contact dermatitis-causing substances concentrations in 28 commercial oxidative hair-coloring products. This study was aimed to provide the fundamental data about oxidative hair-coloring products. We selected 10 oxidation dyes (p-phenylenediamine, toluene-2,5-diamine, m-phenylenediamine, nitro-p-phenylenediamine, p-aminophenol, m-aminophenol, o-aminophenol, p-methylaminophenol, N,N'-bis(2-hydroxyethyl)-p-phenylenediamine sulfate, 2-methyl-5-hydroxyethylaminophenol) and 4 heavy metal (nikel; Ni, chromium; Cr, cobalt; Co, copper; Cu) as contact dermatitis-causing substances. To identify 10 oxidation dyes, hexane-2% sodium sulfite was used for the rapid and simple extraction and ultra performance liquid chromatography (UPLC) analysis was used for simultaneous analysis in 12 minutes. 10 oxidative dyes were detected as indicated on the product packaging and each concentration was lower than prescribed upper concentration limit by pharmaceutical manufacturing standards. And we analysed inductively coupled plasma-optical emission spectrophotometer (ICP-OES) for content search of heavy metal after microwave digestion. The heavy metal average concentration in oxidative hair-coloring products was 0.572 ${\mu}g/g$ for Ni, 3.161 ${\mu}g/g$ for Cr, 2.029 ${\mu}g/g$ for Co, 0.420 ${\mu}g/g$ for Cu, respectively. The average of concentration in powder type (henna) was higher than those of other foam and cream type oxidative hair-coloring products as follows; 1.800 ${\mu}g/g$ for Ni, 10.127 ${\mu}g/g$ for Cr, 7.082 ${\mu}g/g$ for Co, 1.451 ${\mu}g/g$ for Cu. Hair coloring products were classified into the six colors - black, dark brown, brown, dark brown, light brown, red brown and analyzed. Brown color had the highest average concentration of Co and the others had the highest average concentration of Cr.

• Journal of environmental and Sanitary engineering
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• v.23 no.2
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• pp.35-45
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• 2008

In order to recommend criteria for the administration law on indoor air quality, this study was conducted to examine the distribution and the concentration of indoor air pollutants ($PM_{10},\;CO_2$, CO, HCHO, TBC, $NO_2$, Rn, VOCs, asbestos, $O_3$) in public facilities in the Chung-Nam area. The concentrations of indoor air pollutants were obtained from sixty seven public facilities such as a cinema, an office, a restaurant, a theater and an academy. This study was performed from August to December, 2005. The results of this study showed that the concentrations of indoor air pollutants such as $PM_{10},\;CO_2$, CO, HCHO, TBC, Rn and $O_3$ were less than the recommended limits. However, the average concentration of VOCs was $521.73{\mu}g/m^3$ (GM : $221.69{\mu}g/m^3$), which was higher than the recommended limit of $400{\mu}g/m^3$. Moreover, the average concentration of $NO_2$ was 345.66ppb (GM : 69.95ppb), which was higher than the recommended limit of 50 ppb. The correlation between the concentrations of indoor air pollutants and the type of facilities with respect to $CO_2$, TBC and Rn was statistically low (p<0.05). However, the correlation was high in terms of the CO and $O_3$ concentrations (p<0.01). No relationship between the indoor air pollutants and the type of facilities was observed for $PM_{10}$, VOCs and $NO_2$. The year of construction was compared to the concentrations of indoor air pollutants. Specifically, when the construction date was less than 3 years, the HCHO, VOCs and TBC concentrations were $44.75{\mu}g/m^3,\;555.07{\mu}g/m^3$ and $337.79CFU/m^3$, respectively. These concentrations were $120{\mu}g/m^3$ and $211.84CFU/m^3$ higher for VOCs and TBC than the concentrations obtained from the facilities more than 3 years. However, the concentration of HCHO was similar between the facilities older and younger than 3 years of age. Year, temperature, humidity and indoor air pollutant correlation analyses showed that temperature and humidity, temperature and TBC, temperature and $O_3,\;PM_{10}$ and $NO_2$, HCHO and VOCs, $CO_2$ and Rn had positive relationships. However temperature and Rn, humidity and $CO_2,\;CO_2$ and $O_3,\;O_3$ and Rn had negative relationships. Accordingly, it will be necessary to manage the factors affecting indoor air quality so that the residents can have a more comfortable and healthier living environment. Ultimately, the results of this study are expected to be utilized as baseline data.

• Elastomers and Composites
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• v.45 no.2
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• pp.122-128
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• 2010

We measured shear viscosity of copoly(styrene(St)/butyl methacrylate(BMA)) (co-PSB) particles, with a capillary rheometer at $170^{\circ}C$, prepared by suspension polymerization with hydrophobic silica as a stabilizer. co-PSB particles with the weight average molecular weights of lower than 74,800 g/mol displayed a Newtonian behavior at low shear rates. With the weight average molecular weight exceeding 136,800 g/mol, co-PSB particles showed shear thinning against shear rates and the absolute value of the slopes between shear viscosity vs. shear rate increased. When the ratio between St and BMA changed from 7/3 to 5/5 to 3/7, shear viscosity and glass transition decreased despite similar molecular weights. When the ratio was 1/9, it showed a large increase in initial shear viscosity despite reduced glass transition. Shear viscosity exhibited an increase in proportion to carbon black concentration. The effect of carbon black concentration on the shear viscosity of co-PSB composites was less pronounced compared to varying molecular weights and/or compositional ratio.

• Journal of The Korean Society of Agricultural Engineers
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• v.46 no.7
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• pp.35-44
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• 2004

In this study, a ventilation model was developed to determine a ventilation rate for the balance of heat, moisture and $CO_{2}$ in a mushroom house. Internal and external temperature, relative humidity and $CO_{2}$ concentration were measured and used to validate the ventilation model. The effects of various environmental factors on physiological responses of mushroom were also investigated. The verified model was simulated under the observed ventilation rates with a difference of$ 0.001{\~}0.065\;m^{3}{\cdot}S^{-1}$ (relative error of $0.3{\~}18.9\%$) when external temperature varied 22.5 to $24.8^{circ}C$ and average ventilation rates was $0.35m^{3}{\cdot}S^{-1}$. The optimal conditions for mushroom growth (internal temperature $22 ^{circ}C$, relative humidity $80\%$, $CO_{2}$ concentration 1,000 ppm) were used for the model application with external temperature, relative humidity and $CO_{2}$ concentration of $27.5{\~}33.5^{circ}C$, $60\%$, and 355 ppm, respectively. Thermal balance was a important factor for an optimum ventilation up to the external temperature of $32^{circ}C$, while $CO_{2}$ concentration balance was more important over $32^{circ}C$. This suggests that humidification for moisture balance is required to maintain temperature and $CO_{2}$ concentration at an optimal level by ventilation in a mushroom house.

• Journal of Korean Society for Atmospheric Environment
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• v.9 no.1
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• pp.61-68
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• 1993

Since November 1990, the observations of carbon dioxide$(CO_2)$ levels have been carried out at Tae-ahn Peninsula(TAP) in Korea. Analysis on atmospheric data obtained in the period from November 1990 to August 1992 is carried out and the results are included in this study. It is observed that variations of monthly average level on $CO_2$ are in the range of 315.72 $\sim$ 365.37ppm(amplitude 17.65ppm). The seasonal variation is large with a maximum occurring in March-April and with a minimum in July-August. A comparison of TAP data is made with data obtained at Ryori in Japan for 1991. The annual average value of TAP is 1.79ppm higher than that of Ryori. It is also found that in summer the minimum level of $CO_2$ at TAP is almost same as the $CO_2$ level occurring at Quinghai Province in China and at Ulaan Uul in Mongolia. Albeit, a maximum concentration of $CO_2$ at TAP is slightly higher than that of the same gas observed at other sites in spring. We interpret that TAP is generally under the influence of airflows coming from China. According to analysis of trajectories and airflows, we find the high values of $CO_2$ when an air flow is originated mainly from China and when an airflow is both of local(Korea) and of China origins. In contrast, when an airflow of maritime origin arrives, a low value of the atmospheric constituent is observed at TAP.

• Advances in environmental research
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• v.11 no.1
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• pp.17-30
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• 2022

Road transport allows all forms of land conditions to be met at less cost. Because of this function, despite numerous disadvantages, it becomes the most frequently used method of transport, especially in underdeveloped or developing countries. One of the most significant factors used in evaluating the atmosphere's air quality is the amount of CO₂, increasing people's density in indoor spaces. The amount of CO₂ indoors is, therefore, vital to determine. In this study, CO₂ and temperature measurements made on nine different bus journey was made in Turkey. The minimum and maximum values were recorded as 555 ppm and 3000 ppm CO₂, respectively, in the measurements. On all journeys, the average concentration is 1088.72 ppm. The minimum and maximum values were measured as 17.4℃ and 32.7℃ in the temperature measurements, and the average of all trips was calculated to be 25.76℃. In this study conducted before the Covid-19 pandemic, it was determined that the amount of CO₂ increased with the density and insufficient ventilation in the buses. The risk of infection increases in places with high human density and low clean air. For situations such as pandemics, CO₂ measurement is a rapid indicator of determining human density.

• Journal of Preventive Medicine and Public Health
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• v.23 no.4 s.32
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• pp.391-403
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• 1990

In order to assess the degree of atmospheric pollution and noise and to contribute the health improvement of residents in Pusan, the author measured the levels of CO, $SO_2,\;NO_2$, TSP, HCHO and noise in 8 areas (industrial, residential and park areas) from January to March in 1990. The results were as follows : 1. Sasang industrial area was significantly higher($2.85{\pm}0.84ppm$) in the average concentration of CO than other areas. However, there no areas to affect the human body in terms of CO concentration. 2. In general, industrial area was significantly higher ($0.134{\pm}0.084ppm$) in the average concentration of $SO_2$ than other areas, and it was the lowest ($0.009{\pm}0.005ppm$) in the Namchon-dong area. 3. Industrial ($0.033{\pm}0.009ppm$) and residential area ($0.029{\pm}0.004ppm$) were significantly higher in the average concentration of $NO_2$ than Park area ($0.009{\pm}0.001ppm$). However, there were no areas to affect the human body in terms of $NO_2$ concentration. 4. Sasang industrial area was the highest ($580.4{\pm}415.26{\mu}g/m^3$) at the average concentration of TSP and Hae-Un Dae area was the lowest ($97.22{\pm}37.86{\mu}g/m^3$). But TSP concentration showed the level to affect the human body in most areas. 5. Industrial area was significantly higher ($2.25{\pm}1.15ppb$) in the average concentration of HCHO than residential ($1.13{\pm}0.25ppb$) and park area ($1.33{\pm}0.20ppb$). 6. Industrial area was significantly higher ($77.28{\pm}6.92dB(A)$) in the level of noise than residential ($65.77{\pm}3.76dB(A)$) and park area ($64.65{\pm}5.25dB(A)$). In comparison with regional Standard Noise Level, howeverm the average noise level of residential and park area was higher than that of the Standard. In general, the level of pollution of industrial complex areas was relatively higher than those of residential and park areas. Among the industrial areas, sasang area was worst in most items. Both $SO_2$ and TSP showed the level to affect the human body in most of studied areas. It is necessary to install a new Air Quality Standard for HCHO to screen our environmental pollution.

• Journal of Korean Society for Atmospheric Environment
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• v.27 no.1
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• pp.97-116
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• 2011

This study analyzed indoor air pollutants from elementary school with different environment. Air sampling and measurement were carried out from classrooms and hallways from three target elementary schools in the fall and winter seasons. The winter average concentrations of $PM_{10}$, $CO_2$, CO, aldehydes and ketones, and benzene were higher than the fall ones. The fall average concentrations of $O_3$ and $NO_2$ were higher than the winter ones. The concentrations of $PM_{10}$ and $CO_2$ at the schools near the heavy traffic areas and having poor ventilation were higher than those from the other elementary school. The average concentration of CO at the school having heavy traffic volume was highest. The concentrations of $O_3$, $NO_2$, aldehydes and ketones, and VOCs at the school near the shipbuilding industries were highest among the three elementary schools.

• Journal of environmental and Sanitary engineering
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• v.18 no.3 s.49
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• pp.78-88
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• 2003

This study was conducted to investigate the relation between ozone concentration and the affecting factors in Seosan City of Korea from Jan. 2002 to Dec. 2002. We analyzed the air pollutants such as NO$_2$, PM$_{10} $,SO$_2$, CO and the meteorological factors including solar radiation, air temperature, wind speed and relative humidity. The analytical data were taken statistics by SPSS method. The results were as follows: The seasonal average concentration of ozone were detected 35.0 ppb in Spring, 25.4 ppb in Summer, 23.5 ppb in Autumn and 21.4 ppb in Winter. So the difference of concentrations showed significantly in statistics. The hourly ozone concentration in a day was increased at 7-9 AM, peaked at 3-4 PM. The correlation coefficients was negative to ozone concentration and NO$_2$, SO$_2$, CO, relative humidity, but positive to solar radiation, air temperature, wind speed. With stepwise multiple regression analysis on the 8 factors such as NO$ _2$, PMSO$_{10}$,SO$_2$, CO, solar radiation, air temperature, wind speed and relative humidity, the seasonal primary factors were air temperature in spring, relative humidity in summer and solar radiation in autumn and winter. The above results suggest that ozone is the secondary pollutant by photochemical reaction as the concentration of ozone was increased with the raise of solar radiation.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.2
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• pp.143-152
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• 2008

This study investigates the variation and spatial distribution of nitrogen dioxide($NO_2$) concentrations measured with passive diffusive samplers at 40 curbside points in Daejeon. Average $NO_2$ concentration was $39.8{\pm}18.0\;ppb$ (n=1,127) and the significant difference in concentrations by regional groups (Dong-gu, Jung-gu, Seo-gu, Daedeok-gu, Yuseong-gu) was not observed. The frequency distribution of $NO_2$ concentration was found to be a normal distribution with the high frequency in the concentration range of 30 to 40 ppb (20 to 25%). Average $NO_2$ concentration measured during the rainy periods was lower than that measured during the non-rainy periods and the decrease of concentration by rainfall was about 16% (7 ppb). The variation of $NO_2$ concentrations measured by passive diffusive samplers during the sampling period was similar to that continuously measured at the air quality monitoring station.