• Economic and Environmental Geology
• /
• v.38 no.4 s.173
• /
• pp.435-450
• /
• 2005

The purpose of the study is to analyze the hydrogeochemical characteristics by multivariate statistical method, to interpret the hydrogeochemical processes for the new variables calculated from principal components analysis (PCA), and to infer the groundwater flow and circulation mechanism by applying the geostatistical methods for each element and principal component. Chloride and nitrate are the most influencing components for groundwater quality, and the contents of $NO_3$ increased by the input of agricultural activities show the largest variation. The results of PCA, a multivariate statistical method, show that the first three principal components explain $73.9\%$ of the total variance. PC1 indicates the increase of dissolved ions, PC2 is related with the dissolution of carbonate minerals and nitrate contamination, and PC3 shows the effect of cation exchange process and silicate mineral dissolution. From the results of experimental semivariogram, the components of groundwater are divided into two groups: one group includes electrical conductivity (EC), Cl, Na, and $NO_3$, and the other includes $HCO_3,\;SiO_2,$ Ca, and Sr. The results for spatial distribution of groundwater components showed that EC, Cl, and Na increased with approaching the coastal line and nitrate has close relationship with the presence of agricultural land. These components are also correlated with the topographic features reflecting the groundwater recharge effect. The kriging analysis by using principal components shows that PC 1 has the different spatial distribution of Cl, Na, and EC, possibly due to the influence of pH, Ca, Sr, and $HCO_3$ for PC1. It was considered that the linear anomaly zone of PC2 in western area was caused by the dissolution of carbonate mineral. Consequently, the application of multivariate and geostatistical methods for groundwater in the study area is very useful for determining the quantitative analysis of water quality data and the characteristics of spatial distribution.

• Korean Journal of Soil Science and Fertilizer
• /
• v.26 no.2
• /
• pp.103-110
• /
• 1993

This study was made to evaluate the chemical properties of 481 farmers' orchard fields in An-Seong area. And the reasonable ferilizer rates were recommended utilizing the result of soil analysis. The results are summarized as follows : 1. As the soil fertility status of collected soil samples were evaluated on the basis of temporary optimal range for each soil chemical properties, 12.7 to 49.6% of the total 481 farmers' fields were range for soil improvement. 2. The contents of chemical component have a tendancy to decrease with depth gradually from surface to subsoil. 3. According to the relationship between the contents of soil component in subsoil and those in surface soil, the fertility condition of subsoil could be estimated on the basis of analysis data of surface soil. 4. The multiple regression equation for pear yield prediction to the organic matter and exchangable calcium contents in the soil were obtained. 5. Referring the average value, distribution ratio compared to the optimum level for each soil chemical properties and standard fertilizer rate, the soil fertility status could be categorized as "High" "Medium" and "Low". For each category, the recommended amounts for NPK and organic matter application were established. 6. The recommended rates through soul fertility diagnosis were less than farmer's dosage in the range 7.1~7.7 kg/10a for N, 0.8~11.5 kg/10a for $P_2O_5$, 7.1~19.9 kg/10a for $K_2O$ and 90~116 kg/10a for lime.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.9 no.4
• /
• pp.499-505
• /
• 2021

The purpose of this study is to investigate experimentally the physical/chemical properties of concrete surface according to types of formworks. Plywood formwork and coated plywood formwork were prepared. In addition, plywood formwork with sand paper was prepared to simulate deterioration of concrete or rough surface of concrete. Normal concrete was used in this study. The properties of concrete surface were investigated by visual inspection, scanning electron microscopy and energy-dispersive X-ray spectroscopy techniques, elemental mapping, 2D and 3D surface profile measurement, and zeta potential measurement. Test results showed that concrete in a coated formwork had smooth surface and concrete in the formwork with sand paper had rough surface. It was observed that properties of concrete surface depended on types of formworks. Furthermore, differences in surface roughness were significantly higher than those in chemical compositions and zeta potential.

• Clean Technology
• /
• v.16 no.1
• /
• pp.26-32
• /
• 2010

The low temperature pyrolysis of polypropylene (PP), polystyrene (PS) and polypropylene-polystyrene (PP-PS) mixture in a batch reactor at the atmospheric pressure and $450^{\circ}C$ was conducted to investigate the synergy effect of PP-PS mixture on the yield of pyrolytic oil. The pyrolysis time was varied from 20 to 80 mins. The products formed during pyrolysis were classified into gas, gasoline, kerosene, gas oil and heavy oil according to the petroleum product quality standard of Ministry of Knowledge Economy. The analysis of the product oils by GC/MS(Gas chromatography/Mass spectrometry) showed that new components were not detected by mixing of PP and PS. There was no synergy effect according to the mixing of PP and PS. Conversions and yields of PP-PS mixtures were linearly dependent on the mixing ratio of samples except for heavy oil yields. Heavy oil yields showed almost constant regardless of the mixing ratio.

• Proceedings of the Korean Environmental Health Society Conference
• /
• 2005.11a
• /
• pp.130-133
• /
• 2005

황사는 대기오염과 관련하여 심혈관계 및 호흡기계 질환으로 인한 사망 의 증가 등의 건강 영향으로 인해 관심의 대상이 되어왔다. 그러나 최근의 황사성분을 분석한 연구결과에 따르면 실제로 황사기간 동안에 전체먼지농도 중 조대먼지농도의 비율은 증가한 반면 미세먼지농도의 비율은 감소하였고 유해한 중금속의 농도도 별다른 변화를 보이지 않거나 오히려 감소하였다. 이에 본 연구에서는 서울시의 2000년부터 2002년, 2월부터 5월까지의 황사시기를 포함한 경우와 포함하지 않은 경우를 비교하여 황사현상으로 인한 대기먼지가 총사망에 미치는 영향을 비교하였다. 분석결과에 따르면 총사망에 미치는 대기먼지의 영향은, 황사시기를 포함하여 분석한 경우보다 황사시기를 제외하고 분석한 경우에서 더 큰 건강영향을 보였다. 즉, 황사시기를 제외하고 분석한 경우에서 대기먼지가 총사망에 미치는 위험의 크기가 더 큰 것으로 나타났다. 이는 황사의 화학성분 및 황사시 사람들의 행동양식의 변화와 같은 노출의 감소로 설명될 수 있으며 이는 도시 대기오염의 건강위해성을 평가함에 있어서 황사시기를 포함하여 분석하는 경우 도시 대기오염, 특히 대기먼지의 위해도를 과소평가할 가능성이 있으며, 지금까지 제안되는 기존의 연구결과보다 실제 도시 미세먼지의 건강영향이 훨씬 더 클 수 있음을 본 연구결과가 제시하고 있다.

• Journal of the Korean Chemical Society
• /
• v.30 no.5
• /
• pp.465-474
• /
• 1986

The solvent extraction and cleanup processes for the simultaneous gas-liquid chromatographic determination of 11 kinds of organophosphorous pesticide residues in crops were investigated. The extracts dissolved with acetone were partitioned with petroleum ether after adding saturated NaCl solution. Evaporated the partitioning solvent, the residue was dissolved in methylene chloride and eluted through mixed adsorbent (1 : 2 : 4 of activated carbon, magnesia and diatomaceous earth) with methylene chloride as an eluent. The pesticides recovered were 82∼105% and the impurities were effectively removed.

• Journal of the Korean Institute of Gas
• /
• v.10 no.4 s.33
• /
• pp.29-33
• /
• 2006

Estimation of process safety is important in the chemical process design. Prediction for flash points of flammable substances used in chemical processes is the one of the methods for estimating process safety. Flash point is the property used to examine the potential for the fire and explosion hazards of flammable substances. In this paper, multivariate statistical analysis methods(partial least squares(PLS) quadratic partial least squares(QPLS)) using experimental data is suggested for predicting flash points of flammable substances of binary systems. The prediction results are compared with the values calculated by laws of Raoult and Van Laar equation.

• Journal of Conservation Science
• /
• v.21
• /
• pp.89-100
• /
• 2007

This study analyze concentration of minor and trace elements on 47 white porcelains excavated from Dudong-ri, Baekryeon-ri, Sachon-ri kilns in Gyeonsangnam-do by NAA(neutron activation analysis) and try to classify the provenance and characteristics according to the analytical result. Each kilns are divided into the group by PCA(principal component analysis) and LDA(linear discrimination analysis) using 17 elements; Ba Ce, Co, Cr, Cs, Dy, Eu, Hf, La Lu, Rb, Sc, Sm, Ta, Th, V, Yb. The contribution elements are Dy, Sm, La, Ce, Lu, Sc. And soft and hard white porcelains are similar with the chemical composition of the use materials therefore the difference of the chemical composition not confirmed a cause. The analytical results of the fine(I) and poor(II) quality white porcelains presume the difference of the povenance of clay materials or the poduction process such as difference purify and additive materials.

• Journal of the Korean GEO-environmental Society
• /
• v.3 no.2
• /
• pp.49-60
• /
• 2002

A study on mineral composition and chemical component governing of weathering process is necessary to know the weathering characteristics of sedimentary rocks. In this study, a mineral and chemical component analysis, and physical and engineering characteristic tests were conducted to find out the characteristics of sedimentary rocks in Daegu, according to the weathering degree of sedimentary rock. Test results show that the mineral composition of rock, such as Albite (Ab), Muscovite (Ms), Magenetite (Mt) and the chemical composition of $A_2O_3$, CaO, $Na_2O$, $K_2O$, MgO and so on are closely related to the weathering. Based on the test results, we illustrated the quantitative application of weathering decision for the sedimentary rocks.

• Journal of the Mineralogical Society of Korea
• /
• v.4 no.2
• /
• pp.108-118
• /
• 1991

경남 울산군 농소면의 울산사문석광산에서 세피오라이트(sepiolite)가 발견되었다. 그래서 이 세피오라이트시료에 대해 X-선회절분석, 열분석, 적외선분광분석, 투과전자현미경관찰 및 화학분석을 행하여 그 결과를 기술하였다. 본 세피오라이트는 사문암과 염기성암체와의 접촉부에 발달된 열극충진상 세맥에서 산출된다. 이 세맥내에서 많은 암편들이 포함되어 있는데, 그 기질부분은 회백색을 띠며 연질이고 부드러운 가죽같은 느낌을 준다. 이 기질부분이 거의 순수한 세피오라이트로 구성되어 있다. X-선회절분석의 결과로부터 이 광물시료가 결정도가 높은 {{{{ alpha }}-세피오라이트에 해당된다는 것이 밝혀졌다. 이 세피오라이트의 화학성분은 Mg를 많이 함유하는 일반적인 세피오라이트와 유사하였다. 산상 및 광물학적 특성으로 볼 때 이 세피오라이트는 열수용액에서 직접 침전하여 형성된 것으로 사료된다.