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        검색결과 5,320

        5124.
        1998.12 KCI 등재 서비스 종료(열람 제한)
        The sericite ore is formed by the hydrothermal alteration of rhyodacitic welded tuff. The alteration zone of the host rock can be classified into four types based on the mineral assemblages ; sericite, quartz-sericite, silicified and propylite zone. The sericite ore mainly occurs as vein types and fault clay along the fault plane in the quartz-sericite zone. Mineral components of the sericite ore are mainly sericite with minor diaspore, corundum and pyrite. The sericitic porcelaineous ore is mainly composed of quartz and sericite. Accessory minerals are muscovite, diaspore, sphene, corundum, pyrite, iron-oxides and etc. The chemical compositions of K2O, Al2O3, and ignition loss in the sericite ore increase largely than that of the host rock, while the compositions of SiO2, Na2O and Fe2O3 decrease. XRD patterns of the heat-treated sericite ores show the formation of mullite at 1,200℃. and the diaspore-bearing sericite ore forms mullite and corundum at 1,200℃. The differential thermal analysis of the sericite ores show small endothermic peak at 645~668℃. and the diaspore-bearing sericite ore shows a strong endothermic peak at 517℃. It indicates that the decomposition of diaspore appear at lower temperature than that of sericite. The thermal expansivity of the sericite ores show the similar pattern. The sericite ores show the thermal expansivity of 3.3~4.7% at 900℃ and 0.39~0.75% at 1,200℃, respectively. DTA-TG curves of the sericite ores show closely relations with the thermal expansivity.
        5125.
        1998.10 KCI 등재 서비스 종료(열람 제한)
        The concentrations and wet deposition flux into the sea of heavy metals of precipitation in Pusan area were measured and estimated. The samples were collected by polyethylene bottle(30ℓ) from January to November in 1996, and heavy metals were analyzed by atomic absorption spectrometer. The concentration order of heavy metals was Al >Fe >Zn >Pb >Mn >Cu >Ni >Cd >Co, and they were high at inland sites and low at coastal sites. The enrichment factors for some metals(Zn, Cu, Pb, Cd), based on crustal Al, were significantly greater than unity, and the order was Cd > Pb > Zn > Cu. This evidence suggests Cd and Pb are derived predominantly from non-crustal sources. Al, Fe and Mn contents showed good correlation with each other. Therefore this enrichment factor indicates similar geochemical behavior of these elements. The annual wet depositional flux(㎎/㎡/yr) from P1 site was as follows: Al (121.1), Fe,(177.2), Zn(12.9), Mn(6.19), Pb(14.4), Cu(0.64), Ni(1.03), Cd(1.02) and Co(1.01).
        5126.
        1998.10 KCI 등재 서비스 종료(열람 제한)
        The chemical characteristics of precipitation was investigated in Pusan area. Samples were collected from January to November in 1996 at 4 sites, and analyzed pH, mayor soluble ionic components(Cl^-, NO_3^-, SO_4^2-, Na^+, K^+, NH_4^+, Mg^2+, Ca^2+). The order of anion and cation concentrations for the initial precipitation were Cl^- > SO_4^2- > NO_3^- , and Ca^2+ > Na^+ > NH_4^+ > Mg^2+ > K^+, respectively. At coastal sites(P1 and P2) Cl^- and Na^+ of maritime sources (seasalt) were high, but at inland sites(P3 and P4) nss-Ca^2+ and nss-SO_4^2- were high. Calcium ion for the initial precipitation showed high value of enrichement factor(EF) relative to seawater composition. The contribution of seasalt to the composition of precipitation was higher at site P1 (53.5%) than those of the other sites. Throughout the year the concentrations of major ions for the initial precipitation were low in the heavy rain season. The mean pH for the initial precipitation was 5.4 and showed the negative relationship with the precipitaion amount. The SO_4^2- and NO_3^- do not play an important role in rain acidification due to the high(97%) neutralizing effect of amonia and calcium species.
        5128.
        1998.09 KCI 등재 서비스 종료(열람 제한)
        의성지역의 약용작물 생산현황(生産現況) 및 경영분석(經營分析)을 위하여 약용작물 재배 농가 147호를 대상으로 재배실태와 작물별 소득(所得)을 조사(調査)한 결과는 다음과 같다. 1. 특화계수(特化計數)가 1이상인 작물은 작약(21.59), 산수유(14.82), 시호(7.90), 지모(6.41), 지황(3.96), 두충(3.44), 목단(2.28), 백지(1.51)순으로 나타났다. 2. 조사농가의 평균 토지이용면적(土地利用面積)은 1.92ha이었는데, 그중 밭이 1.35ha. 논은 0.56ha이었다. 농지분포(農地分布)는 농가당 평균 3.1곳에 10.2필지로 구성되어 있으며, 약용작물부문에 년간 노동투하(勞動投下)는 31.1%를 차지하였다. 3. 조사대상 지역에 재배되고 있는 약용작물은 36개 작물로 농가당 평균 2.4작물이었다. 대표적인 작물은 작약이었는데, 조사농가 147호 가운데 85농가가 참여하여 30.72ha를 재배하고 있었다. 4. 약용작물 재배실태를 보면, 작약, 시호, 택사, 길경, 황기, 감국 등은 재배면적이 줄어드는 추세(趨勢)이고 홍화는 새로운 소득작물(所得作物)로 재배되고 있으며, 더덕, 지모, 지황, 원황정, 백출 등은 재배 면적이 늘어났다. 5. 36개 약용작물중 10a당 평균소득이 높은 작물은 홍화(2,775천원), 원황정 (2,706천원), 일천궁(2,573천원) 등의 순이었으나 재배농가에서는 농가여건에 부응하면서 위험부담이 적고 가격안정(價格安定)이 기대되는 작물을 선택하여 농가 수준에서 부가가치(附加漂値)를 최대한 증대(增大)시켜야 할 것으로 생각되었다.
        5129.
        1998.08 KCI 등재 서비스 종료(열람 제한)
        Precipitation samples were collected at sixteen sites in Northeast Asia from June 1995 to February 1997, and were analysed for the anions SO_4^2- NO_3^- and Cl^- and for the cations Na^+, NH_4^+, K^+, Mg^2+ and Ca^2+ in addition to pH and conductivity measurements. The quality assurance of chemical composition data was checked by considering the ion balance evaluating by │h│ value and the conductivity balance. The sum of cation concentrations were slightly greater than the sum of anion concentraions. For the anions, SO_4^2- clearly dominates in most of sampling sites whereas Cl^- is more abundant in coast and rural sites in Japan. For the cations, Ca^2+ and NH_4^+ are generally the more abundant ions except when sources of Na^+ exist. The contribution rate of nss-SO_4^2- and NO_3^- to acidity are about 70% and 10-30%, respectively. The neutralizing capacity by a major neutralizing cations such as NH_4^+ and nss-SO_4^2+ are above 98%(heavy polluted and urban sites in China), above 70%(urban sites in Japan and in Korea, coast sites in China) and above 60%(rural sites in Japan and in Korea), respectively.
        5130.
        1998.08 KCI 등재 서비스 종료(열람 제한)
        The two-stage numerical model was used to study the relation between three-dimensional local wind model, advection/diffusion model of random walk method and second moment method in western coastal area for Korean peninsula. The first stage is three dimensional time-dependent local wind model which gives the wind field and vertical diffusion coefficient. The second stage is advection/diffusion model which uses the results of the first stage as input data. First, wind fields on Korean peninsula for none synoptic scale wind showed typical land and sea breeze circulation, and the emitted particles were transported by sea breeze for daytime, emissions return to sea by land breeze for nighttime.
        5131.
        1998.08 KCI 등재 서비스 종료(열람 제한)
        One hundred and thirty two ground water samples from the Ulsan area were divided into urban and non-urban groupings and were assessed between 1993 and 1996. The results of statistical analysis were as follows: There were significant differences between the two groupings in the average value of the following water quality parameters: total hardness, nitrate, pH, iron, ammonia and chloride ion in the order of Z-score. Because total hardness, nitrate, and pH were also significant in ANOVA test, these three parameters can be regarded as the most sensitive parameters of artificial pollutants. By the comprehensive comparison of Ulsan water quality to that of Kangwon-do, all of the major parameters(pH, KMnO_4 consumption, sulfate, chloride and hardness except nitrate) were confirmed as being significantly increased levels.
        5132.
        1998.08 KCI 등재 서비스 종료(열람 제한)
        우리나라 서남부지역은 금강, 만경강, 동진강, 영산강 및 이들 하구 담수호와 관련하여 용수수급에 있어 불균형을 이루고 있는 실정이다. 예를 들면, 금강하구호는 저수용량이 작기 때문에 많은 양을 바다로 버리고 있는 실정이다. 반면, 현재 건설중인 새만금호는 비교적 저수용량에 비하여 유입량이 적은 편이다. 그리고 영광, 영암의 경우와 같이 영산강 하류 지역은 용수수요량은 많고 공급량은 부족한 실정이다. 이러한 용수수급의 불균형을 해결하고, 수자원의 이용 효
        5133.
        1998.08 KCI 등재 서비스 종료(열람 제한)
        The objective of this study is to approach on the spatial boundary of rural development protect by areal classification technique with spatial reference to searching of areal homogeneities in two hierachial administrative units, Ri Eup/Myun. In this study, a criterion for judging areal homogeneities is the degree of agriculture and urbanizing. Variables selected by these two criteria are analysed with the method of fator analysis. The results of areal analysis are as follows: first, generally, the importance of agricultural factors in areal analysis is getting less. Second, areal classification by Myun, Ri in Ansong City is revealed variously because of urban factors. Urban factors make areal heterogeneities become greater, Therefore urban factors are important when analyzing areal characteristics. Third, lately, in areas near by Chung- cheong Do and areas with bad road's condition, areal heterogeneities have been also getting greater. The results of analysis about areal characteristics of Myun and Ri are different from each other. In addition, urban factors are more influential on the areal characteristics than agricultural factors. Therefore, the establishment of rural development project for inindle spatial boundary between Myun unit and Ri unit is needed.
        5134.
        1998.08 KCI 등재 서비스 종료(열람 제한)
        A small wastewater collection system for rural area was reviewed and the small diameter gravity (SDG) was thought to be the most appropriate. The pilot-scale field experiment was performed for 15 months and the result is presented. The wastewater used for experiment was the effluent of septic tank in Kon-Kuk University, and components are similar to normal domestic wastewater. The SDG experimental system included 2" PVC pipe and reverse-sloped lower section is included. No clogging problem by solids was experienced at the points where flow direction changed. The pipe-breaking by freezing was experienced during the cold weather, thus proper protection may be required where severe weather is expected.
        5135.
        1998.06 KCI 등재 서비스 종료(열람 제한)
        The structure such as building and cultural properties was composed of various materials like wood, metal and stone that have been utilized and exposed to air, wind and rain for a long time. However, because of their special characteristics as structure, collecting of samples that may involve their destruction cannot be permitted, ever for material analysis. Therefore, in order to study the influence of atmospheric pollution on structure, atmospheric corrosion tests were achieved by making use of materials(bronze, ancient copper, copper, steel and marble) in field exposure tests. Atmospheric exposure sites are selected from places which are characterized by urban, rural, industrial and marine environments in Northeast Asia. According to the results of atmospheric corrosion tests; The corrosion rates of industrial sites in china were more serious than other sampling sites. In the correlation of meteorological factors, wet hours was defined as integrated hours under that atmospheric temperature is above O℃ and relative humidity in above 80% that has a great influence on corrosion tests of materials in case of a short time. The relative humidity was above about 75% that resulted in great increase of corrosion rates. In the esimation of corrosion rates between materials, corrosion rates of steel was about thirty times and decuple larger than that of other materials excluding marble in unshelterd exposure and in sheltered exposure.
        5137.
        1998.06 KCI 등재 서비스 종료(열람 제한)
        Textures of claystones of the Cheonunsan Formation in the Hwasoon area have been studied using optical microscope and electron microprobe. Microscopic images were observed under the optical microscope using the transmitted polarizing light from thin sections and under the electron microprobe using the back-scattered electron beam from the polished sections. Identification of minerals were made using X-ray diffraction analysis and chemical analysis by electon microprobe. Textural analyses show that the original sedimentary claystones rich in aluminium were subjected to metamorphism by which they changed to the metamorphosed claystone consisting mainly of chloritoid, quartz, andalusite and illite. Later intensive hydrothermal kaolinization of this metamorhosed claystones resulted in the formation of high-aluminous claystones rich in kaolinite exhibiting various complicated replacement textures.
        5138.
        1998.04 KCI 등재 서비스 종료(열람 제한)
        In this research, two stochastic models are considered to detect and estimate the effect of air temperature change due to industrialization in Ulsan area. Using the monthly mean minimum air temperature anomalies, the data are divided into pre-industrialization part and industrialization one for analysis. The ARMA(autoregressive moving-average) model and intervention model have been applied to the data for the analysis. The results show that the variability of minimum temperature anomalies are very significant in 1989, and also significant in 1971 when the industrialization have started. Therefore, it is stochastically possible to estimate the time when the affection of increase of the temperature concerning industrialization to climate change in Ulsan area has happened.
        5139.
        1998.04 KCI 등재 서비스 종료(열람 제한)
        The purpose of this study was to investigate the pollutions of water qualities in 30 water samples from Nakdong River, Western Nakdong River, and Suyoung Stream. COD, BOD, T-N and negative ions(F-, Cl- NO3-, SO42-) of water samples were analyzed and the correlationships between water qualities were examined. The mean concentrations of COD(20.26ppm), BOD(25.36ppm), and T-N(18.05ppm) were the highest in the water sample of Suyoung Stream among the three streams and those of F-(0.25ppm), Cl-(27.70ppm), and SO2-(37.66ppm) in Western Nakdong River, that of NO_3,(10.81ppm) in Nakdong River. The water quality of Suyoung Stream was the worst among the three streams in Pusan area. The correlationships between water qualities were as follows ; BOD and COD showed very high correlationship(correlation coefficient, r=0.97), SO42- and NO3- did high one(0.75), and NO3- and COD, BOD did relatively high ones(0.56 and 0.48, respectively).
        5140.
        1998.04 KCI 등재 서비스 종료(열람 제한)
        A preliminary study on the chemical compositions of forty seven precipitations from March 1994 to May 1995 in Yeoncheon-gun, which is adjacent to the southern boundary of demilitarized zone (DMZ) in the northernmost tip of Kyunggi province has been performed. The metal cation and anion concentrations were measured by atomic absorption spectrometer and ion chromatography, respectively. pH/Ion meter and direct nesslerization method were used for the concentration measurements of H- ion and NH_4+ ions, respectively. Based on the data, the quantitative orders of the cation and anion average concentrations were Ca2+ > NH_4+ > Na+ > K+ > Mg2+ > H+ and SO_42- > Cl- > NO_3-, respectively. The ratio of average total anion concentration to average total cation concentration was 0.97. The average pH value of the precipitations was 5.60. These results, correlation coefficients between the ion concentrations, and monthly variations of pH value and precipitation amount are used for chemical analysis on the environmental pollution and pollutant sources in Yeoncheon-gun of Kyunggi province near DMZ.