간행물
한국환경과학회지 KCI 등재 Journal of Environmental Science International
- 발행기관 한국환경과학회
- 자료유형 학술지
- 간기 월간
- ISSN 1225-4517 (Print)2287-3503 (Online)
- 수록기간 1992 ~ 2023
- 주제분류 자연과학 > 자연과학일반 자연과학 분류의 다른 간행물
- 십진분류KDC 539DDC 628
권호리스트/논문검색
제2권 제1호 (1993년 3월) 8건
1.
1993.03
서비스 종료(열람 제한)
This study was carried out to find the relationships between species pairs in the vegetation of eastern valley vegetation in Mt. KumJung from September 20, 1991 to October 15, 1992. Eight sites were selected, each being divided into 5 quadrats, and thus 40 quadrats were in total. To know the correlation among plant species the x^2 values were calculated by using the method of Yates, and the results were analyzed by cluster analysis according to Sneath and Sokal, and the following conclusions were obtained. The species examined can be subdivided into five groups according to the relationships. However, the relationships are not correlated with pH, water-content, maximum water holding capacity and mineral content of soil probably due to the environmental discontinuity.
2.
1993.03
서비스 종료(열람 제한)
Land-sea breeze over Pusan district is investigated by performing the numerical simulations with orography on a two-dimensional mesoscale model. The model results show that the sea breeze strengthens and begins to move inland at 1000LST. The strongest sea breeze is occurred at 1500LST and begins to weak at 1700 LST. After 2400LST a weaker land breeze compared with the sea breeze develops. The observed datas and the simulated land-sea breeze is not coinsidented exactly at the event day(1983. 9. 19.). But simulated land-sea breeze is corresponded of synoptic characteristics that was studied previously.
3.
1993.03
서비스 종료(열람 제한)
The layer that is directly influenced by ground surface is called the atmospheric boundary layer in comparison with the free atmosphere of higher layer. In the boundary layer, the changes of wind, temperature and coefficient of turbulent diffusion in altitude are large and have great influences an atmospheric diffusion. The purpose of this paper is to express the structure and characteristics of development of mixed layer by using laboratory experiment and numerical simulation. Laboratory experiment using water tank are performed that closely simulate the process of break up of nocturnal surface inversion above heated surface and its phenomena are analyzed by the use of horizontally averaged temperature which is observed. The result obtained from the laboratory experiment is compared with theoretical ones from k-ε numerical model. The results are summarized as follows. 1) The horizontally averaged temperature was found to vary smoothly with height and the mixed layer developed obviously being affected by the convection. 2) The mean height of mixed layer may be predicted as a function of time, knowing the mean initial temperature gradient. The experimental values are associated well with the theoretical values computed for value of the universal constant C_T=0.16, our C_T value is little smaller than the value found by Townsend and Deardorff et al.
4.
1993.03
서비스 종료(열람 제한)
Based on the Results of Marine Meteorological and Oceanographical Observations during 1966∼1987 and the Ten-day Marine Report during 1970∼1989 by Japan Meteorological Agency, the possible area where the Japan Sea Proper Water (JSPW) can be formed is investigated by analyzing the distribution of water types in the Japan Sea. The Japan Sea can be divided into three subareas of Northern Cold Water(NCW), Polar Front(PF) and Tsushima Warm Current (TWC) by the Polar Front identified by a 6℃ isothermal line at the sea surface in winter. Mean position of the Polar Front is approximately parallel to the latitude 39∼40°N. The standard deviation of the Polar Front from the mean position of about 130㎞ width is the smallest in the region between 136°E and 138°E where the Polar Front is very stable, because the branches of the Tsushima Current are converging in this region. However, standard deviations are about 180∼250㎞ near the Korean peninsula and the Tsugaru Strait due to greater variability of warm currents. In the NCW area north of 40°30`N and west of 138°E, the water types of the sea surface to the 100m depth are similar to those of the JSPW. This fact indicates that the surface layer of the NCW area is the possible region of the JSPW formation in winter.
5.
1993.03
서비스 종료(열람 제한)
Concentrations of sulfate and δ-values of sulfate, (δ^34SO_4)_pw, dissolved in pore waters were measured from the sediment cores of the two different marine environments: deep northeast Pacific (ST-1) and coastal Kyunggi Bay of Yellow Sea (ST-2). Sulfate concentration in pore waters decreases with depth at both cores, reflecting sulfate reduction in the sediment columms. However, much higher gradient of pore water sulfate at ST-2 than ST-1 indicates more rapid sulfate reduction at ST-2 because of high sedimentation rate at the coastal area compared to the deep-sea. The measured 6-values, (δ^34SO_4)_pw, follow extremely well the predicted trend of the Rayleigh fractionation equation. The range of 26.7‰ to 61.3‰ at the coastal core ST-2 is not so great as that of 32.4‰ to 97.8‰ at the deep-sea core ST-1. Despite greater gradient of pore water sulfate at ST-2, the δ-values become lower than those of the deepsea core ST-1. This inverse relation between the S-values and the gradients of pore water sulfate could be explained by the combination of the two subsequent factors: the kinetic effect by which the residual pore water sulfate becomes progressively enriched with respect to the heavy isotope of ^34S as sulfate reduction proceeds, and the intrinsic formulation effect of the Rayleigh fractionation equation in which the greater becomes the fractionation factor, the more diminished values of (δ^34SO_4)_pw are predicted.
6.
1993.03
서비스 종료(열람 제한)
Mercuric chloride, inorganic compound, is one of the most important drugs that has been used in the field of argriculture, antisyphilitica and anticeptics, but it is not used clinically at present. We have studied the effect of testosterone on the mercuric chlorideinduced nephrotoxicity. Renal lipid peroxide concentration of male rat treated with mercuric chloride was significantly increased in comparison with that of the female rat, it showed similar effects on testosterone pretreatment. Changes in renal catalase and glutathione peroxidase activities were not siginificantly different in testosterone-treated groups. But, renal xanthine oxidase and aldehyde oxidase activities of testrosterone-treated group given mercuric chloride significantly increased in comparison with that of the testosterone-treated alone. Animals treated with testosterone prior to mercuric chloride showed more severe damage on histological observations than those treated with testosterone only. Consequently, we suggest that the mercuric chloride-induced nephrotoxicity might be renal lipid peroxide generating enzyme system by testosterone.
7.
1993.03
서비스 종료(열람 제한)
Result of this study indicate that two criteria must be met in order to have effective macrocycle-mediated transport in these emulsion system. First, one must effective extraction of the post transition metals, Cd^2+ Pb^2+ and Hg^2+,into toluene membrane. The effectiveness of this extraction is greatest if log K values for the metal-macrocycle interaction is large. Second, the ratio of the log K values for the metal ion-receiving phase to the metal ion-macrocycle interaction must be large enough to ensure quantitative stripping of the metal ion at the toluene phase interface. Control of the first step can be obtained by appropriate selection of macrocycle donor atom, substituents, and cavity radius. The second step can be controlled by selecting the proper complexing agent for inclusion in the receiving phase. The order of the transport, when using the several A^- species such as SCN^-,I^-,Br and Cl^- is the order of the changing degree of solvation for A^- and the transport of the metals is also affected by the control of concentration for receiving species because of solubility-differences. In this study, we can seperate each single metal ion from the mixture of Cd^2+, Pb^2+, and Hg^2+ ions by using the toluene membranes controlled by optimized conditions. Transport of the single metal is also very good, and alkaline and alkaline earth metals as interferences ions did not affect the seperation of the metals in this macrocycle-liquid membrances but transition metal ions were partially affected as interferences for the post transition metal ions.
8.
1993.03
서비스 종료(열람 제한)
Adsorption process using granular activated carbon(GAC) has been considered as one of the most effective water treatment technologies to remove humic acid which is recognized as trihalomethane(THM) precursor in chlorination. To design the most effective GAC process, it is necessary to conduct the test of adsorption performance by means of isothem, batch rate and column studies and to select the most effective activated carbon according to raw materials of GAC-lignite and coconut shell. The objective of this study is to investigate the adsorption performance of humic acid on two activated carbons- lignite activated carbon(LAC) and coconut shell activated carbon(CAC) made in Korea. It is available to represent UV-abs and trihalomethane formation potential(THMFP) as concentration of humic acid due to good relationship. The adsorption capacity of humic acid is not concerned with surface area of activated carbon but with pore size related to about 100 A, and then LAC forming at the extent of mesopore is found to be eight times more effective in adsorption capacity than CAC forming at micropore. The adsorption capacity of LAC and CAC is better at pH 5.5 than at pH 7. Pore and surface diffusion coefficients calculated from the diffusion model are 7.61×10 exp (13)㎡/sec, 3.52×10 exp(-15) ㎡/sec for CAC, and 3.38×10 exp (-12)㎡/sec and Ds=1.48×10 exp (-15)㎡/sec for GAC respectively. From the results of column test it shows that the performance of LAC is also better than CAC and the optimal EBCT(Empty Bed Contact Time) is 4.52min. and activated carbon removes selectively the components of humic acid to be easily formed to THM.
