• Journal of Food Hygiene and Safety
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• v.30 no.1
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• pp.87-91
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• 2015

Eight minerals (Ca, Cu, Fe, K, Mg, Mn, Na and Zn) were determined in Schizandra chinensis fruits and their infusions in Seoul. The average mineral contents per Schizandra chinensis fruits (100 g) were K (966.08 mg), Mg (87.20 mg), Ca (15.19 mg), Mn (6.19 mg), Fe (3.99 mg), Zn (2.78 mg), Na (2.15 mg) and Cu (0.31 mg) respectively by Inductively Coupled Plasma-Mass Spectrometer. The quantity of K and Zn were found significantly higher in Korean fruits than the Chinese fruits (p < 0.05). The other 6 minerals did not reveal remarkable difference. In the case of processed Schizandra chinensis tea, it had K (217 mg), Mg (20.40 mg), Ca (7.16 mg), Na (2.95 mg), Mn (1.34 mg), Fe (0.95 mg), Zn (0.25 mg) and Cu (0.09 mg) per 100 g respectively. In extraction of Schizandra chinensis fruits, as it took a longer extraction time, and in a powder form rather than a raw form, it had a higher contents of minerals. When a powder type of Schizandra chinensis fruits was extracted for 24 hours at $25^{\circ}C$, the transfer rate appeared with Ca (36.27%), Mn (25.44%), K (22.43%), Zn (21.00%), Na (19.91%), Mg (19.55%) Cu (13.78%) and Fe (6.45%) respectively.

• Corrosion Science and Technology
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• v.17 no.3
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• pp.101-108
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• 2018

AA7010 is an Al-Zn-Mg-Cu alloy containing Zr, developed as an alternate to traditional AA7075 alloy owing to their high strength combined with better fracture toughness. It is necessary to improve the corrosion resistance and surface properties of the alloy by incorporating plasma electrolytic oxidation (PEO) method. AA7010-T7452 aluminum alloy has been processed through the forging route with multi-stage working operations, and was coated with $10{\mu}m$ thick $Al_2O_3$ ceramic aluminina coating using the plasma electrolytic oxidation (PEO) method. The corrosion, stress corrosion cracking (SCC) and nano-mechanical behaviours were examined by means of potentiodynamic polarization, slow strain rate test (SSRT) and nano-indentation tests. The results indicated that the additional thermomechanical treatment during the forging process caused a fully recrystallized microstructure, which lead to the poor environmental cracking resistance of the alloy in 3.5% NaCl solution, despite the overaging treatment. Although the fabricated PEO coating improved general corrosion resistance, the brittle nature of the coating did not provide any improvement in SCC resistance of the alloy. However, the hardness and elastic modulus of the coating were significantly higher than the base alloy.

• Korean Journal of Materials Research
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• v.19 no.10
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• pp.533-537
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• 2009

This paper presents a new method for the improvement of color temperature without the change of the driving scheme using transparent dielectric layers with various metal oxides (CeO$_2$, Co$_3$O$_4$, CuO, Fe$_2$O$_3$, MnO$_2$, NiO) in plasma display panels (PDP). In this study, we fabricated ZnO-B$_2$O$_3$-SiO$_2$-Al$_2$O$_3$ glasse with various metal oxides and examined the optical properties of these glasses. As the metal oxides were added to the glasses, the visible transmittances of the dielectric layers decreased and the transmittances in special wavelength regions were reduced at different rates. The change of the transmittance in each wavelength range induced the variation of the visible emission spectra and the change of the color temperature in the PDP. The addition of Co$_3$O$_4$ and CuO slightly decreased the intensity of the blue light, but the intensities of the green and the red light were significantly decreased. Therefore, the color temperature can be improved from 6087K to 7378K and 7057K, respectively.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.4
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• pp.346-353
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• 2012

The Laser-Induced Breakdown Spectroscopy (LIBS) has great advantages as an analytical technique, namely real-time analysis without sample preparation, ideal for mobile chemical sensor for space exploration. The LIBS plasma characteristics are strongly dependent on the surrounding pressure. In this study, seven types of target (C, Ti, Ni, Cu, Sn, Al, Zn) were investigated for their elemental lifetime. The target was located in vacuum chamber which has the pressure range of 760 to $10^{-5}$ torr. As the pressure is decreased, the elemental lifetimes of carbon and titanium declined, while all other targets showed increased lifetimes until reaching 1 torr and declined with continued pressure decrease. The boiling point and electronegativity amongst the physicochemical properties of the samples are used to explain this peculiarity.

• Proceedings of the Korean Environmental Health Society Conference
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• 2003.06a
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• pp.89-93
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• 2003

Daily average concentrations of fine particulates have been measured simultaneously in Seoul and Asan area by using PM minivolTM portable air sampler(Air Metrics, U.S.A) from September 2001 to August 2002. The sampler were analyzed by ICP-OES(inductively coupled plasma optical emission spectrometry, optima 3000DV, Perkin Elmor) to determine the fine particulate concentrations of metallic elements(As, Mn. Ni, Fe, Cr, Cu, Cd, Pb, Zn, Si). The concentration of PM$\sub$2.5/ showed a high trend in the Seoul area. Zn showed a similar distribution ratio for the fine particle in both Seoul and Asan. Mn and Fe, Cr, Cd are highly correlated in the Seoul and Asan area(P<0.05).

• Analytical Science and Technology
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• v.32 no.4
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• pp.121-130
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• 2019

Alumina is one of the most important ceramic materials because of its useful physical and chemical properties. Recently, high-purity alumina has been used in various industrial fields. This leads to increasing demand for reliable elemental analysis of impurities in alumina samples. However, the chemical inertness of alumina makes the sample preparation for conventional elemental analysis a tremendously difficult task. Herein, we demonstrated the feasibility of laser ablation for effective sampling of alumina powder. Laser ablation performs sampling rapidly without any chemical reagents and also allows simultaneous optical emission spectroscopy and mass spectrometry analyses. For six alumina samples including certified reference materials and commercial products, laser-induced breakdown spectroscopy (LIBS) and laser-ablation inductively-coupled plasma mass spectrometry (LA-ICP-MS) analyses were performed simultaneously based on a common laser ablation sampling. LIBS was found to be useful to quantify alkali and alkaline earth metals with limits-of-detection (LODs) around 1 ppm. LA-ICP-MS could quantify transition metals such as Ti, Cu, Zn, and Zr with LODs in the range from a few tens to hundreds ppb.

• Journal of Advanced Marine Engineering and Technology
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• v.23 no.3
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• pp.360-368
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• 1999

The paper describes spectroscopic characteristics of plasma induced in the pulsed YAG laser welding of alloys containing a large amount of volatile elements. The authors have conducted the spectroscopic analyses of laser induced Al-Mg alloys plasma in the air and argon atmosphere. In the air environment the identified spectra were atomic lines of Al, Mg, Cr, Mn, Cu, Fe and Zn and singly ionized Mg lines as well as the intense molecular spectra of ALO and MgO formed by chemi-cal reactions of evaporated Al and Mg atoms from the pool surface with oxygen in the air. In argon atmosphere MgO and AlO spectra vanished but AlH spectrum was detected. the hydrogen source was presumable hydrogen dissolved in the base metals water absorbed on the surface oxide layer or $H_2$ and $H_2O$ in the shielding gas. The resonant lines of Al and Mg were strongly self-absorbed in particular self-absorption of the Mg line was predominant. These results show that the laser induced plasma was made of metallic vapor with relatively low temperature and high density.

• Journal of Korea Soil Environment Society
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• v.5 no.2
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• pp.67-85
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• 2000

Fifty seven soil samples were collected from the paddy soil filled with tailings in the vicinity of the Seosung Pb-Zn mine. Those samples were analyzed for As, Cd, Co, Cr, Cu, Pb, and Zn in order to investigate heavy metal pollution levels in the paddy soil. Analyses of the soil samples were carried out using Inductively Coupled Plasma Atomic Emission Spectrometry(ICP-AES) . Paddy soils show pH range from 6.55 to 8.26. X-ray diffraction analyses of the paddy soil indicate that the soils consist predominantly ankerite, siderite, quartz, mica, and clay minerals with minor amounts of amphibole and chlorite. The mineral composition of the waste rocks consists of massive galena, sphalerite, and minor amounts of pyrite, arsenopyrite, chalcopyrite, calcite, siderite, Pb-sulfosalt, and marcasite. The paddy soils were significantly contaminated by heavy metals(average concentrations, As: 334.4 ppm, Cd: 37.6 ppm, Co: 15.7 ppm, Cu: 214.1 ppm, Pb: 4,612 ppm, and Zn: 4,468 ppm).

• Journal of the Korean Applied Science and Technology
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• v.24 no.3
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• pp.233-237
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• 2007

This study is focused on the possibility of copper alloy metal fiber for an antimicrobial activity in the water soluble metal working fluids. Electrochemical potential of Cu/Zn ion is -268mV, and easily makes radicals with molecular oxygen. Especially, hydroperoxide radical shows strong toxicity to the strains. Plasma membrane causes conformational change when hydroperoxide radical binds to plasma membrane. Elution of copper ion from copper alloy metal fiber is detected in metal working fluid. As a result antimicrobial activity of copper alloy metal fiber in metal working fluid is superior to that of copper fiber.

• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.1
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• pp.22-26
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• 1984

The effect of changes in body weight, some blood components and some inorganic ions in liver and kidney, were studied on male rats receiving ad libitum on 5, 40, and 200 ppm of mercuric chloride solution during so days. The results obtained were summarized as follows ; 1. The total body weights were decreased in proportion to increment of mercury concentration. The internal organs weights i. e. , liver, kidney, spleen, and heart, were generally increased. Especially, the weight increment of kidney was the highest by intaking of mercuric chloride solution. 2. There were no significant changes in hematocrit values, activities of GOT and GPT in blood of rats receiving mercuric chloride. On the other hand, the plasma levels of cholesterol were significantly increased. The receiving of 200 ppm mercuric chloride solution to rats was resulted in the remarkable reduction of total protein levels and A/G ratio in plasma. 3. The markable rise occured in the accumulation of Hg, in both liver and kidney in proportion to supplying in rats while there was a tendency decreasing of Cu, Zn contents in liver, whereas there was a tendency increasing of Cu, Zn in kidney of rats.