• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.41 no.2
• /
• pp.200-206
• /
• 1996

Experiment was conducted to get the information about physico-chemical properties of flue-cured tobacco on the degree of maturity cultivated in paddy-upland rotated field, and compared to upland ones. For the samples of this experiment, 3~4 leaves at each stalk position were harvested from the bottom of plants. Physico-chemical properties of cured leaves were determined from the samples collected at weekly intervals, and of obtained from 4 stalk positions. For the degree of maturity, harvested leaves were separated with visual characters into four classes such as immature, mature, ripe, and mellow. Regardless of stalk position, the order of shrinkage rate with length and width of leaves was mellow> immature> ripe> mature, and ripe leaves from paddy field showed higher shrinkage rate than those of upland. Nicotine and total nitrogen contents were decreased with the degree of maturity while reducing sugar content were showed a reverse tendency. Ripe leaves from paddy field had lower reducing sugar contents, comparing with upland tobacco. Filling capacity of cured leaves from paddy field was decreased with degree of maturity, but there was no difference between upland and paddy tobacco. Shatter index was increased in the oeder of immature > mellow > mature > ripe. Chemical components of cigarette smoke from paddy field tobacco were little higher in $CO_2$ total particulate matter and tar contents, while combustibility was little lower than that of upland tobacco. It was also evaluated that paddy field tobacco was unfavorable for the non-volatile organic and higher fatty acids contents comparing with upland tobacco.

• Journal of Korean Society for Atmospheric Environment
• /
• v.33 no.5
• /
• pp.497-514
• /
• 2017

This study quantitatively analyzes the effects of emission inventory choices on the simulated particulate matter (PM) concentrations and the domestic/foreign contributions in the Seoul Metropolitan Area (SMA) with an air quality forecasting system. The forecasting system is composed of Weather Research and Forecasting (WRF)-Sparse Matrix Operator Kernel Emissions (SMOKE)-Community Multi-Scale Air Quality (CMAQ). Different domestic and foreign emission inventories were selectively adopted to set up four sets of emissions inputs for air quality simulations in this study. All modeling cases showed that model performance statistics satisfied the criteria levels (correlation coefficient >0.7, fractional error <50%) suggested by previous studies. Notwithstanding the apparently good model performance of total PM concentrations by all emission cases, annual average concentrations of simulated total PM concentrations varied up to $20{\mu}g/m^3$ (160%) depending on the combination of emission inventories. In detail, the difference in simulated annual average concentrations of the primary PM coarse (PMC) was up to $25.2{\mu}g/m^3$ (6.5 times) compared with other cases. Furthermore, model performance analyses on PM species showed that the difference in the simulated primary PMC led to gross model overestimation in general, which indicates that the primary PMC emissions need to be improved. The contribution analysis using model direct outputs indicated that the domestic contributions to the annual average PM concentrations in the SMA vary from 44% to 67%. To account for the uncertainty of the simulated concentration, the contribution correction factor method proposed by Bae et al. (2017) was applied, which resulted in converged contributions(from 48% to 57%). We believe this study shows that it is necessary to improve the simulated concentrations of PM components in order to enhance the accuracy of the forecasting model. It is deemed that these improvements will provide more accurate contribution results.

• Journal of Environmental Health Sciences
• /
• v.37 no.1
• /
• pp.44-49
• /
• 2011

Under the Enforcement Rules of the National Health Promotion Act, smoking areas in coffee shops in Korea should be divided off from other areas. The effect on indoor air quality of different division types for smoking areas was evaluated. Using real-time monitors, fine particulate matter <2.5 ${\mu}m$ in diameter ($PM_{2.5}$) concentrations were measured simultaneously in the smoking and non-smoking areas of 30 coffee shops in Seoul. Average $PM_{2.5}$ concentrations in smoking and non-smoking areas were 132 ${\mu}g/m^3$ and 52 ${\mu}g/m^3$, respectively; significantly different. Average $PM_{2.5}$ concentrations in non-smoking areas were 39 ${\mu}g/m^3$ in the glass-wall type and 64 ${\mu}g/m^3$ in the separate-floor type. These $PM_{2.5}$ levels were above the US national ambient air quality standard of 35 ${\mu}g/m^3$. Although indoor $PM_{2.5}$ levels in non-smoking areas were reduced by the division, the rates of reduction were not significantly different by division type. Our results demonstrated that $PM_{2.5}$ from smoking areas can infiltrate into non-smoking areas. Therefore, a complete indoor smoking ban in coffee shops is the only way to protect customers and workers in non-smoking areas.