• Journal of the Korean Chemical Society
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• v.37 no.10
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• pp.861-866
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• 1993

In general, the concentration of constituents can be more accurately measured in x-ray fluorescence analysis of Fe-Ni-Cr alloy by reducing and correcting the matrix effect with standard ingot samples. Because of the difficult the treatment at a high temperature in preparing the ingot samples of various concentrations, several standard specimens were prepared by mixing the powders of the metallic oxides in certain proportions and pressing them with a costant pressure. With the metallic oxide specimens thus obtained, different matrix coefficients were calculate from the intensities of the strength of the x-ray fluorescence and the concentration of the substances. It is found that effects of Fe and Cr on Ni are absorption rich and effects of Fe and Ni on Cr are enhancement rich, whereas Ni enhances Fe Fluorescence but Cr absorves Fe K${\alpha}$ line. And the x-ray fluorescence intensities were compared and analyzed between the metallic oxides and the ingot samples.

• Journal of the Mineralogical Society of Korea
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• v.21 no.2
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• pp.161-175
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• 2008

The soil developed from volcanic ash in Jeju Island, Korea, were classified as typical Andisols. The soils had acidic pH, high water contents, high organic matters and clay-silty textures. The crystalline minerals of the samples were mainly composed of ferromagnesian minerals such as olivine and pyroxene, and iron oxides such as magnetite and hematite derived from basaltic materials. A large amount of gibbsite was found at the subsurface horizon as a secondary product from the migration of excessive aluminum. In addition, our study has shown that considerable amounts of poorly ordered minerals like allophane and ferrihydrite were present in Jeju soils. The contents of $SiO_2$ were lower than those of other soil orders, but $A1_2O_3$ and $Fe_2O_3$ contents were higher. These results are some of the important chemical properties of Andisols. The contents of heavy metals were in the range of $84{\sim}198$ for Zn, $56{\sim}414$ for Ni, $38{\sim}150$ for Co, $132{\sim}1164\;mg\;kg^{-1}$ for Cr, which are higher than the worldwide values in most of the soils. Some soil samples contained relatively high levels of Cr exceeding 1000 mg/kg. Mean reduction capacity of the Jeju soils was $6.53\;mg\;L^{-1}$ reduced Cr(VI), 5.1 times higher than that of the non-volcanic ash soils from inland of Korea. The soil reduction capacity of the inland soils had a good correlation with total carbon content (R = 0.90). However, in spite of 20 times higher total carbon contents in the Jeju soils, there was a week negative correlation between the reduction capacity and the carbon content (R = -0.469), suggesting that the reduction capacity of Jeju soils is not mainly controlled by the carbon content and affected by other soil properties. Correlations of the reduction capacity with major elements showed that Al and Fe were closely connected with the reduction capacity in Jeju soil (R = 0.793; R = 0.626 respectively). Moreover, the amounts of Ni, Co and Cr had considerable correlations with the reduction capacity (R = 0.538; R = 0.647; R = 0.468 respectively). In particular, in relation to the behavior of redox-sensitive Cr, the oxidation of the trivalent chromium to mobile and toxic hexavalent chromium can be restricted by the high reduction capacity in Jeju soil. The factors controlling the reduction capacity in Jeju soils may have a close relation with the andic soil properties explained by the presence of considerable allophane and ferrihydrite in the soils.

• Journal of Food Hygiene and Safety
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• v.14 no.3
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• pp.305-318
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• 1999

This study were conducted to estimate the values of the heavy metal in the fresh water fish and shellfish collected from fish market. The levels of the heavy metal were determined in a total of 319 samples of 11 species of the fresh water fish and 14 species of the shellfish by mercury analyzer and atomic absorption spectrophotometer. The results of this study were summerized as follows; The average contents of the heavy metal in the fresh water fish were Pb 0.075, Hg 0.05:3, Cd 0.002, Cr 0.135, Fe 8.695, Mn 1.078, Zn 9A91, Cu 0.548 mg/ kg. The average contents of the heavy metal in the shellfish were Pb 0.059. Hg 0.007, Cd 0.146, Cr 0.147, Fe 40.808, Mn 7.738, Zn 13.943, Cu 2.7:31 mg/kg. Being compared the average contents of the heavy metal of the fresh water fish with those of shellfish, the average contents of Cd, Fe, Mn, Cu in the shellfish were significantly higher than in the fresh water fish(P<0.001). Depending on the sampling areas, the average contents of the heavy metal were different by districts. The contents of the heavy metal were changed with the seasons(P<0.05).

• Korean Journal of Environment and Ecology
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• v.14 no.2
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• pp.119-126
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• 2000

충남 사문암 지역인 광천, 홍성, 백동, 대흥 및 유구지역의 토양, 식물체(참억새, 쑥, 리기다소나무) 및 지표수, 갱내수의 중금속 함량을 분석한 결과 사문암 토양의 Ni, Cr 및 Co 원소가 변성암 토양에 비하여 10~13배높았으며 이 원소들이 serpentine factor로 생각된다 사문암 지역간에는 이들원소의 차이가 뚜렷하지 않았다 변성암 토양식물에서보다 사문암 토양 식물에서 Ni, Cr, Co등이 높았다 리기다소나무의 원소 흡수량은 비교적 낮았고 3종 식물에서 대체로 뿌리의 원소 함량이 지상부 함량보다 높았으며 사문암 토양에서는 Ni, Cr, Co, Mo, Sc, As 및 Fe 원소들이 쑥보다 참억새에서 높았다 사문암 토양에서 생육하는 식물체 지상부의 생물학적 흡수계수는 Ni, Cr, Co, Zn, Sc, As 및 Fe 원소는 참억새에 높고Zn은 쑥에서 높았다,. 사문암 토양에서 뿌리로부터 지상부로의 원소 전이는 Ni, Cr, Co, Zn As 및 Fe 원소에 대해 쑥에서 높았고 Mo와 Sc 원소는 리기다소나무에서 높았다. 따라서 사문암 토양에서 참억새가 중금속의 흡수율은 높고 중금속에 대한 내성은 강할 것으로 사료된다 대흥지역에서 광산의 오염이 지표수 및 갱내수의 Ni. Cr, Co, Zn 및 Fe 등의 원소 농도를 높게 하였으며 비오염 계류는 오염계류의 원소 농도를 희석시켰다.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.6
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• pp.446-452
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• 2000

This study was carried out to investigate the effect of mine activity on paddy fields, agricultural water, and plants in the ruined Oksung Cu-Zn mine area. Soil samples collected from paddy fields adjacent to the Cu-Zn mine sites were sequentially extracted and determined the contents of heavy metals such as Cd, Zn, Cu, Pb, Cr and Ni. Distribution of exchangeable heavy metals in soils was 30.2% of Cd, 11.3% of Zn, 2.2% of Cu, 4.6% of Cr, 0.6% of Pb and 3.9% of Ni. Water soluble heavy metals were only detected with Zn. The contents of heavy metals in water collected from the mine were 0.01 of Cd, 27.35 of Zn, 4.86 of Cu, 1.04 of Pb, 0.03 of Cr and $0.08mg\;L^{-1}$ of Ni. while the contents in waler collected out of the mine were 16.67 of Zn, 0.59 of Cu, 0.49 of Pb, 0.05 of Cr and $0.06mg\;L^{-1}$ of Ni. On the other hand, agricultural water near mine area were 1.26 of Zn, 0.05 of Cu, 0.05 of Pb and $0.02mg\;L^{-1}$ of Ni. Both Cd and Cr were not detected in the agricultural water.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2008.11a
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• pp.81-82
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• 2008

하이브리드 코팅 시스템을 이용하여 $CrMoC_xN_{1-x}$ 박막을 AISI D2와 실리콘 웨이퍼 모재 위에 증착하였다. 박막 내 탄소 함량은 $CH_4/(CH_4+N_2)$ 가스 유량 증가에 비례하여 증가했다. 탄소 함량이 0.33일 때 44GPa의 최대강도 및 -4.4GPa의 잔류응력을 나타내었다. CrMoN 박막의 평균 마찰계수는 0.42이지만, 탄소함량을 증가함에 따라 0.31까지 감소 하였다. 이것은 박막 표면과 스틸볼 사이에서 탄소가 풍부한 층이 형성되어 일종의 고체윤활제 역할을 했기때문이다. 박막의 미세조직은 X-ray diffraction, Scanning electron microscopy, 그리고 X-ray photoelectron spectroscopy를 이용하여 분석하였다.

• Korean Journal of Food Science and Technology
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• v.28 no.1
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• pp.90-98
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• 1996

The mineral contents were analyzed for 12 varieties of Korean apples and 9 commercial apple juices by atomic absorption spectrophotometry. On the fresh matter basis, the ash contents of tested apples ranged 0.21-0.48%, Mn 0.20-2.52 ppm, Cu 0.10-1.03 ppm, Fe 0.24-9.88 ppm, Zn 0.09-1.06 ppm, Mg 21.08-99.00 ppm, Ca 15.16-99.56 ppm, K 842.10-1788.10 ppm, Na 10.32-40.53 ppm, P 24.43-90.07 ppm, Pb nd-98.05 ppb, Cd nd-36.08 ppb and Cr 2.25-123.76 ppb. Overally mineral contents of Aori and Jonathan were higher than those of Fuji. The mineral contents of apple cultivated at Wonju, Kangwon and Taegu, $Ky{\check{o}}ngbuk$ were higher than those of the other growing region. The mineral contents of commercial apple juice were ash 0.13-0.36%, Mn 0.24-0.99 ppm, Cu 0.10-0.61 ppm, Fe 0.19-3.70 ppm. Zn 0.20-1.77 ppm, Mg 18.16-49.56 ppm, Ca 14.42-42.30 ppm, K 785.07-1440.30 ppm, Na 14.71-52.58 ppm, P 16.57-63.56 ppm, Pb nd-95.55 ppb, Cd nd-17.65 ppb and Cr 8.60-110.98 ppb, respectively. Comparing mineral contents of apples and commercial apple juices, Cu, Mg, K, Ca and Fe contents of apples were higher and Zn, Na contents were lower than those of apple Juices.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2007.04a
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• pp.38-39
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• 2007

Chromium nitrids(Cr-N)박막은 경질박막재료이며 특히 PVD법을 제조한 CrN 박막은 다른 이원계 박막에 비해 높은 내마모성을 갖는다고 알려져 있다. 본 실험에서는 CrN박막에 Zr을 첨가하여 3원계의 CrZrN 박막을 합성하여 박막의 Zr 함량에 따른 표면경도 및 조도를 측정하고 Ball-on-disk type의 마모실험과 습도제어 하에서의 마모실험을 실시하였다. 박막의 Zr 함량이 증가함에 따라 박막의 표면경도가 증가하고 표면조도는 낮아지는 것을 알수 있었고, 그에 따라 마찰계수 값 또한 낮게 측정되었다. 습도제어하에서는 마찰계수 값은 비슷한 경향을 보였으나 습도가 매우 낮은 건조한 환경에서는 박막의 마찰계수 값이 높게 나타나는 경향을 보였다.

• Journal of the Korean Magnetics Society
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• v.3 no.3
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• pp.221-228
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• 1993

The general requirements of recording media include recording performance, environmental stability, runnability on the drive or deck, and manufacturability. CoCrMo thin films were prepared using RF sputtering system for a study on chemical stability. Surface degradation of the CoCrMo thin film was studied by SEM, XPS and AES. Surface degradation was found to be dependent of sputtering condition and Mo content. Addition of Mo to CoCr thin film improved dramatically its surface degradation resistance in dilute sulfuric acid, as indicated by active-passive transition appeared in electrochemical polarization curve. Futhermore, the passive current density was decreased with increasing Mo content. The reduction in a number density of corrosion sites by Mo addition vms observed, after accelerated corrosion test. AES survey indicated that corrosion occured on the site with Cr depletion and highly concentrated chloride ions.

• Proceedings of the KSEEG Conference
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• 1999.04a
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• pp.39-42
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• 1999

1) 서울 지역 도로가 퇴적물에서는 특히 Cu와 Zn의 오염이 도심 지역을 중심으로 심각하게 진행되고 있으며. Pb는 무연 휘발유의 사용량 증가와 더불어 감소 추세이나 여전히 높은 함량을 나타내고 있다. 2) Pb와 Cr의 함량은 공간적 지배가 강하여 Pb는 주로 교통 혼잡 지역, Cr은 공구상 밀집 지역에서 높게 나타난다. 반면, Cu, Cd, Zn 함량은 시간적 및 공간적 변화를 모두 보여주어 금속 산업 밀집도 및 강우량 변화에 따라 변화된다. 3) 특히 오염이 심화되고 있는 지역의 도로가 퇴적물이 하수계로 직접 유입되지 못하도록 차단하는 적절한 시설이 필요하며, 아울러 오염된 퇴적물을 집적하여 처분할 때는 주변 토양의 오염에 유의해야 할 것이다.