• Journal of the Korean Society for Marine Environment & Energy
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• v.18 no.4
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• pp.245-253
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• 2015

Total acid digestion and 1 M HCl extraction methods were used to investigate the pollution status and the degree of ecological risk of trace metals in surface sediments from the Ulsan-Onsan coast. Total concentrations of trace metals (Cu, Cd, Pb, Zn, and Hg) were two-fold higher in surface sediments from Onsan coast than in those from Ulsan coast. The mean labile fractions of the total concentrations of Cd and Pb were 72% and 78%, respectively, indicating a high contribution from anthropogenic sources, whereas Cr, Li, Ni, and As in the residual fraction exceeded 80%, indicating a high contribution from natural sources. According to the results of assessment of trace metal pollution using the sediment quality guidelines in Korea, the concentrations of Cu, Pb, Zn, and Hg were higher than the values of the probable effects level (PEL) at some stations of Onsan coast, and the concentrations of Cr and Ni were lower than the values of the threshold effects level (TEL). The pollution level and ecological risk of the trace metals were analyzed using various indexes (EF, $I_{geo}$, m-PEL-Q, and ERI). Our results showed that the degree of pollution by trace metals (Cu, Cd, Pb, Zn, and Hg) on the Ulsan-Onsan coast was high, and Hg and Cd were the major potential ecological risk factors.

• 한국해양학회지
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• v.23 no.3
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• pp.110-122
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• 1988

Between the Clarion and Clipperton fracture zones of the Northeastern Pacific, nodules and crusts were collected from abyssal plain and hills by the Korea Ocean Research and Development Institute in December, 1983 aboard the R/V KANA KEOKI of the Hawaii Institute of Geophysics. Mineralogical and geochemical data of bulk nodules are obtained and compared with analyses of other studies. Mechanisms of nodule formation are discussed based on these data. Generally, the nodules of the KONOD-1 site are composed of todorokite and ${\delta}-MnO_2$. The contents of Mn, Fe, Ni, and Cu of the bulk nodules are variable and the average contents of metals are slightly lower (Mn, 21.40%; Ni, 0.9%; Cu, 0.8%) than those of nodules from other abyssal plains between the Clarion and Clipperton fracture zones. High Mn/Fe (average 3.9; maximum 5.9) and Cu/Ni (average 0.8; maximum 1.0) ratios are similar to the nodules that were formed diagenetically in the northeast Pacific. The chemical characteristics of the KONOD-1 nodules reflect their sedimentary environments; nodules with higher diagenetic signatures occur in areas of thin Quaternary siliceous ooze, and nodules of lower diagenetic influence occur in topographically irregular abyssal hill areas.

• Journal of the Microelectronics and Packaging Society
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• v.19 no.4
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• pp.65-69
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• 2012

Composite coating can be manufactured during the electroplating with the bath containing a suspension of particles: ceramic, polymer, nanopowders. Improvement of hardness, wear resistance, corrosion resistance and lubrication properties are well-known advantage of composite coating. In this study, nano $TiO_2$ powder dispersed Ni composite plating was investigated. The improvement of surface hardness and photo decomposition effects can be expected in this coating. Zeta potential was measured with pH. The effect of ultrasonication time and types of ultrasonicator were studied to minimize the agglomeration of $TiO_2$ nanopowders in the electrolyte. Optimum conditions for nano $TiO_2$ dispersed Ni composite coating were $40mA/cm^2$ of current density, pH 3.5, and $50^{\circ}C$. At these conditions, $TiO_2$ nanoparticles contents in the Ni deposit was 15-20 at.%.

• Korean Chemical Engineering Research
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• v.43 no.5
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• pp.588-594
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• 2005

We have investigated Y zeolite and activated carbon for an adsorptive desulfurization of diesel. In batch experiments, cation ($Cu^{2+}$, $Ni^{2+}$) exchanged Y zeolites showed high equilibrium adsorption capacity for sulfur compounds in model diesel, which contained BT, DBT and 4,6-DMDBT of each 50 ppmw in n-octane. But the cation exchanged Y zeolites lost its capacity in commercial diesel (186 ppmw). On the other hand, activated carbon showed reasonable adsorption capacity for sulfur compounds in both model and commercial diesel. The adsorption capacity of sulfur on Ni-Y zeolite was decreased with the increase of benzene concentration in model diesel but the sorption capacity on activated carbon was insensitive to aromatic concentration. In breakthrough test, activated carbon of 1 g could treat 15 ml of commercial diesel with 186 ppmw sulfur. Toluene showed good solvent for regenerating activated carbon among several solvents.

• Korean Journal of Materials Research
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• v.9 no.10
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• pp.985-991
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• 1999

Corrosion behaviors of Incoloy 800H, KSA(Kaeri Superalloy)-6, Inconel 600 and Hastelloy C-276 in molten salts were investigated in the temperature range of 650 ~ $850^{\circ}C$. Due to $\textrm{Li}_{2}\textrm{O}$-induced basic fluxing mechanism, the corrosion rates of the alloys in mixed molten salt of LiC1-$\textrm{Li}_{2}\textrm{O}$ were significantly higher than those in molten salt of LiCl. In the mixed molten salt, Fe-base alloys showed higher corrosion resistance than the Ni-base alloys. and Hastelloy C-276 with high Mo and W contents exhibited the highest corrosion rate among the examined alloys. The single layer of $\textrm{LiCrO}_{2}$ was formed in molten salt of LiCl and two phase structure of a scale consisted of oxides and Ni was formed in the mixed molten salt.

• Resources Recycling
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• v.26 no.2
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• pp.33-38
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• 2017

Waste can be utilized as secondary or alternative fuel. Solid recovered fuel (SRF) and dried sewage sludge were combusted to investigate heavy metal emissions from their combusiton in this study. Content of copper (Cu), chromium (Cr), cadmium (Cd), nickel (Ni), zinc (Zn), lead (Pb), arsenic (As) and mercury (Hg) of coal, SRF and dried sewage sludge were determined, respectively. Concentrations of these heavy metals in the combustion flue gas were also determined. As a result, emissions of gas-phase Cu, Cr, Cd, Ni, Zn, Pb and As compounds were found to be little. However, a significant amount of gas-phase Hg was emitted from combustion of coal, SRF and dried sewage sludge. While SRF showed a high mercury oxidation percentage in its combustion flue gas, dried sewage sludge showed a high level of gaseous mercury emission.

• Resources Recycling
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• v.7 no.4
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• pp.35-42
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• 1998

Surface mount technology is the biggest theme in the area of deιIronic component. To miniatunze an electronic component, s such as ferrite chip inductor, the cer뼈lic wet process for green-sheet lamination and/or screen printing method through a s solvent medium system is widely used. The preparation and characterization of NiCuZn Ferrite (NCZF) shurry and the green s sheet using the water mixed binder system has been studied. The 21 vol% of NCZF slurry was prepared by a ball milling. The p polyacrylic vinyl copolymer (Mw; 60,000) was used as a binder. Th$\xi$ mixture of distilled water, isopropyl alcohol (IPA) and 2l butoxy ethanol was used as a dispersion medium. The water content of medium varied from about 40% to 80%. As the results. Thc disp$\xi$rston stability of the NCZF slurry was attributed to the free polymer rather than the electrostatic force of the particle. T The viscosity of the NCZF slurry was greatly depended on the ratio of water content in the medium.

• Journal of Environmental Health Sciences
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• v.45 no.2
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• pp.154-163
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• 2019

Objectives: The hazardous heavy metal contents of cosmetics were investigated and the resulting values were compared by type of cosmetics: skin care preparations (SCP), hair preparations (HP), makeup preparations (MP), and eye makeup preparations (EMP). Methods: The hazardous heavy metal contents (Pb, As, Cd, Sb, Ni and Hg) were analyzed for 358 cosmetics products (187 SCP, 82 HP, 56 MP, and 33 EMP). Hg was measured by the amalgamation method, and other hazardous heavy metals were measured by inductively coupled plasma optical emission spectrometer (ICP-OES) after decomposition using the microwave method. Results: The mean contents of Pb, As, Cd, Sb, Ni, and Hg in cosmetics were 0.424, 0.068, 0.024, 0.398, $0.567{\mu}/g$, and Not Detected, respectively. All of the hazardous heavy metals were detected in most products, but below the recommended maximums of the Ministry of Food and Drug Safety. The level of Cd was the lowest at 14.8%, and Sb was the highest at 41.2%. Pb, Sb and Ni showed the highest mean value and detection rate in EMP. As, Cd, and Hg showed the highest in SCP, HP, and MP, respectively. Conclusion: Hazardous heavy metals were detected in most products. In particular, Pb, Sb, and Ni were broadly detected in EMP, meaning more stringent quality control is required.

• Journal of the Speleological Society of Korea
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• v.24 no.25
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• pp.69-80
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• 1991

광화시기가 같은 유화광물중에서 상접하는 황철석과 자류철석 내에 함유되어 있는 코발트와 니켈의 함량을 정량분석하여 이들 원소들의 Partition Coefficients로부터 Bezmen method를 이용하여 광물의 생성온도를 구하였다(217～395$^{\circ}$). 지질 연대가 같은 유화광물의 생성온도는 동시기에 생성된 인접한 석영내의 유체포유물의 filling temperature와 거의 일치한다(255～395$^{\circ}$). 따라서 이들 광산내의 광물의 생성온도는 지질온도계로 사용이 가능하며 광물의 생성환경을 규명하는데도 유용할 것이다.

• YAKHAK HOEJI
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• v.4 no.1
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• pp.12-13
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• 1959

The contents of trace elements of the 44 Korean women's hair samples are studied quantitatively by means of th ecircular paper chromatography method in this paper. The elements studied are Fe, Co, Cu, Ni, Mn, Mg, Ca, and Zn. The age distribution of subjectes and the results are shown in table 1 and 2.