To obtain the risk assessment of hazardous materials in Rehmanniae Radix Preparata, the residual pesticides and heavy metals in samples on the Korea and China are surveyed. Group Ⅰ(BHC-δ, BHC-β, Fenitrothion, Penthoate, Endosulfan-α, Dieldrin, Endosulfan-β and Endosulfan-sulfate), Group Ⅱ(BHC-γ, Aldrin, DDD, DDT-p,p Permethrin and Fenvalerate), Group Ⅲ(BHC-α, Chlorpyrifos, Tolyfluanid, Captan and DDT-o,p) and Group Ⅳ(Quintozene, Vinclozolin, DDE and Chlorfenapyr) could analysed on gas chromatography-ECD for evaluation of residual pesticides. Qualified detection concentration on the GC-ECD are 0.45 ng/g～2.50 ng/g. Group Ⅰ, Group Ⅱ, Group Ⅲ and Group Ⅳ are not detected in Rehmanniae Radix Preparata on the Korea and China. Concentration of As, Cd and Pb in Rehmanniae Radix Preparat. on the Korea are 3.06%, 7.00% and 5.78% for Korea Food & Drug Administration(KFDA). Concentration of As, Cd and Pb in Rehmanniae Radix Preparata. on the China are 5.16%, 5.33% and 6.50% for Korea Food & Drug Administration(KFDA). The hazardous materials in Rehmanniae Radix Preparata on the Korea and China were verified the safety of the residual heavy metals and pesticides compare with Korea Food & Drug Administration (KFDA) advisory level.

The concentration of heavy metal were studied for the estimation of quality in herbal medicines which is Bupleuri Radix, Paeoniae Radix, Dioscoreae Rhizoma and Astragali Radix in products of north Gyeongbuk area. Also, we collected soils from several area in Gyeongbuk, and determined heavy metal concentration of soils by ICP. We compared with herbal medicines in products of Gyeongbuk and their soils. The average levels of heavy metal of herbal medicines in Gyeongbuk area are as follows : Mercury is 0.037㎎/㎏, Chromium is 0.093㎎/㎏, Nickel is 0.108㎎/㎏, Copper is 0.475㎎/㎏, Zinc is 3.14㎎/㎏, Manganese is 1.52㎎/㎏, Iron is 7.83㎎/㎏, and Cadmium, Lead and Arsenic is not detected. It was very lower in concentrations than those of average Korea area. For the heavy metals contents of Gyeongbuk area, in Gong Jung Ri, represented the higher level, it may be due to a near the road. The Cd contents in soil was not a wide difference. For the As and Pb contents in soil, Song Sa Ri (Bupleuri Radix) represented the higher level(0.68㎎/㎏, 1523㎎/kg). Correlation coefficients of heavy metal contents in cultured herbal medicines and their soils did not give reproducible results. But the degree of correlation between a few heavy metal contents of Dioscoreae Rhizoma and their soil showed the good transfer from the soil.

Diurnal variations of air quality due to the characteristic features of local weather phenomena over Kunsan, Taegu, and Pohang are analyzed using various synoptic wind fields and the characteristics of local weather during the period of 1990 to 1992. The air pollutants analyzed are sulfur dioxide(SO_2), nitrogen dioxide(NO_2), and oxidants (O_3). The synoptic wind fields estimated at over the 850 hPa geopotential height are divided in terms of four wind directions and two wind speed categories for each season. The synoptic weather conditions are also classified into two categories depending on the total cloud amounts. The present study shows that the SO_2 concentration over Kunsan, and Taegu was maximum at the two or three hours after sunrise and second primary was three or four hours after sunset. On the other hand, its concentration over Kunsan was maximum at 1900 LST or 2000 LST. The O_3 concentration over the three cities shows its maximum in the afternoon when the solar radiation is strong. The NO_2 concentration over Kunsan shows in reverse proportion to the 0_3 concentration over the Kunsan.

This study is an attempt to classify climatic regions of Korea based on the data of sunshine duration and to clarify the characteristics of sunshine for each divided regions. The data used in this study are the mean values of monthly and ten-daily sunshine duration, sunshine percentage, solar radiation and cloud amount obtained from 63 weather stations of the Korea Meteorological Administration during the period of 1974∼1993. The characteristics of annual change of sunshine percentage, annual duration of sunshine, percentage of sunshine, annual radiation, amount of cloud, days of sunshine percentage above 80% and days of sunless are investigated by the mean values of the stations belong to divided regions. The ward method of hierarchical cluster analysis is adopted to the analysis of data for the regional division. The results obtained in this study are summarized as follows. (1) The sunshine regions of Korea can be divided into six regions of the central west, central east, south west, south east, Ullung-do and Cheju-do. These are strongly affected by the distribution of inclined slopes taking account of the topographic characteristics of Korea. (2) Annual distribution shows the sunshine duration of 1777∼2287 hours, sunshine percentage of 40∼53%, solar radiation of 3469∼4637 MJ/㎡, cloud amount of 5.0∼6.1, days of sunshine percentage above 80% of 53∼116days and sunless days of 46∼71days. (3) The types of annual change of sunshine percentages is classified with four types of minimum in July and maximum in October, minimum in July and maximum in December, high in May and October and low in July and January, high in May and November and low in June and January. (4) The Iong-term trend of sunshine duration decrease in peninsula area but increase in island area and the long-term inclination of cloud amount is almost zero. The author believe this tendency is related to a pollutional turbidity than a cloud amount in inland area.

This study is an attempt to investigate the chemical components of precipitation and its variation according to surface wind. Precipitation samples were collected by an wet-only precipitation sampler during the period of October 1994 to September 1995 at Kyungsan in Korea. The results obtained in this study are summerized as follows. The annual average of precipitation pH is 5.0, the highest month of pH is July of 5.5, and the lowest month of pH is December of 4.4. The most frequent appearance is in the range of pH 5.0 to 5.5 and its rate is 56.8%. The order of ion concentration in precipitation is SO4^2->NO3^->Cl^-in case of anion and Ca^2+>NH4^+ >Na^+>Mg^2+ in case of cation. It is found from our analysis that the correlation coefficient among the precipitation pH and ion components is below r=0.3, while the correlation coefficient between SO4^2- and NO3, Na^+ and Cl^- is above r=0.8, respectively. The mean pH of precipitation is 4.8 under the westerly wind and 5.2 under the easterly wind. The concentrations of anion and cation under the westerly wind are more than the concentrations under the easterly wind. In autumn, the concentration of Na^+ and Cl^- under the easterly wind are higher than the concentration under the westerly wind. The correlation coefficients between wind speed and pH, ion components show very low correlation of -0.41≤r≤0.2. But the present study show that the correlation coefficient between wind speed and pH of precipitation is positive and the correlation coefficients between wind speed and ion concentration is negative.

Catalytic slurry reactors, in which a solid maintained in the form of fine particles suspended in a liquid, are frequently used in chemical and biochemical and industries. In these processes the particle loading is normally low so that the effects of particles on the liquid-film mass transfer coefficent and the gas-liquid interface area are assumed to be negligible. But it is known from the works, amongst others, that the finely powdered activated carbon can increase the gas-liquid mass transfer significantly in surface-aerated reactors. The stirred cell (13.2cm inside diameter) contained four baffles and at the stirring speeds range of 80∼300rpm, the gas-liquid interfacial area could be considered as that of the cross section of the vessel (that is, 130.1㎝2). When the stirrer speeds were increased, the effective interfacial area was slightly higher than the geometric area and was obtained experimentally from the Danckwerts`plots.