• Journal of the Mineralogical Society of Korea
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• v.19 no.4 s.50
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• pp.337-346
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• 2006

The Jinwon Pb-Zn deposit is located within the Precambrian Youngnam Massif. Ore mineralization at the Jinwon deposit occurred in quartz veins that filled fractures in the Hongjesa granite. Mineral paragenesis can be divided into two stages(stage I and II). Stage I, at which the precipitation of major ore minerals occurred, is further divided into two substages with paragenetic time based on minor fractures and discernible mineral assemblages: substage la is characterized by pyrite, arsenopyrite ($28.4{\sim}30.3$ atomic % As), pyrrhotite, magnetite, chalcopyrite, sphalerite ($13.1{\sim}16.0$ mole % FeS) assemblages; substage $I_a$ is represented by main precipitation of Zn, Pb minerals and is characterized by sphalerite ($15.1{\sim}19.0$ mole % FeS), galena, miargyrite, argentile assemblages. Stage II is economically barren quartz veins. Thermodynamics study is used to estimate changes in chemical conditions of the hydrothermal fluids during stage I mineralization, the main ore deposition period at the Jinwon hydrothermal system. The range of estimated sulfur fugacity ($fs_2$) was from $10^{-7}\;to\;10^{-16}$ atm and oxygen fugacity ($fo_2$) was in the range of $10^{-32.8}{\sim}10^{-38.5} atm$. Carbon dioxide fugacity ($fco_2$) was $<10^{-0.6} atm$.

• Korean Journal of Microbiology
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• v.30 no.4
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• pp.239-245
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• 1992

Buci1llr.s 11c~h~n~1rnSiSi.As 3-2MI which is responsible for the special taste of traditionalKorean soy sause produced two kinds of proteinase. The activity of the proteinasc I washigher about two fold than that of proteinase 11. The optimai, reaction pH of proteinaseI and I1 wcre found to be 7-1 1.5 and 7-9. respectively. Proteinase I1 was more stable andactive than proteinase I at pH ranges around 3 to 5. The optimal te~tlperature of proteinaseI and I1 were 502. The temperature stabilitl of proteinase I1 was Inore stable thanproteinase 1 at temperature range around 30-quot;~A. ctivities of proteinase I and I1 graduallydeclined above $30^{\circ}$C and 45C. respectively. Proteinasc 1 was more active than proteinaseI1 at salt concentration range around 25-3500. The K,,, values of casein and soy proteinfor proteinase I were 6.89 mglml and 3.98 mglml. In case of proteinase 11. they were 9.00mgiml anti 11.44 111g/ml. respectively. The activity of the crudc enzyme was increased by1 rnM Pb(CH3COO). but was decreased by 5 n1M and 10 rnM of HgS04 and ZnS04. Thetwo proteinases produced amino acids and peptides from the soybean protein. The peptideswere digested into amino acids. Both protcinases were found to be the main enzymes thatproduced amino acids which make the main taste of traditional Korean soy sauce.al Korean soy sauce.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.515-517
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• 2003

In order to assess the risk of adverse health effects on human exposure to arsenic and heavy metals influenced by past mining activities, environmental geochemical surveys were undertaken in the abandoned metal mine areas (Dongil Au-Ag-Cu-Zn, Okdong Cu-Pb-Zn, Songcheon Au-Ag, Dongjung Au-Ag-Pb-Zn, Dokok Au-Ag-Cu and Hwacheon Au-Ag-Pb-Zn mines). Arsenic and other heavy metals were highly elevated in the tailings from the Dongil, the Songcheon and the Dongjung mines. High concentrations of heavy metals except As were also found in tailings from the Okdong, the Dokok and the Hwacheon mines. These significant concentrations can impact on soils and waters around the tailing dumps. Risk compounds deriving from mine sites either constitute a toxic risk or a carcinogenic risk. The hazard index (H.I.) of As in the Dongil, the Okdong, the Songcheon and the Hwacheon mine areas was higher value more than 1.0. In the Okdong and the Songcheon mine areas, H.I. value of Cd exceeded 1.0. These values of As and Cd were the highest in the Songcheon mine area. Therefore, toxic risks for As and Cd exist via exposure (ingestion) of contaminated soil, groundwater and rice grain in these mine areas. The cancer risk for As in stream or ground water used for drinking water from the Songcheon, the Dongil, the Okdong, the Dongjung and the Hwacheon mine areas was 3E-3, 8E-4, 7E-4, 2E-4 and 1E-4, respectively.

• Journal of The Korean Society of Agricultural Engineers
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• v.48 no.1
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• pp.3-10
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• 2006

The chemical fractions of heavy metals were investigated in the soils of reclaimed and natural tidelands of southwest coastal area of Korea. The distribution pattern of each heavy metal in different fractions was in the order: 1) Cu : organic bound > organic complex > residual > exchangeable = water soluble. 2) Cr : residual > organic bound > organic complex > water soluble > exchangeable. 3) Pb : organic bound > residual > organic complex > water soluble > exchangeable. 4) Cd residual > organic bound > organic complex > water soluble = exchangeable. 5) Zn : organic bound > residual > organic complex > water soluble > exchangeable. The content of residual Zn showed positive correlation with organic matter content but organic bound Zn showed negative correlation with CEC. The content of residual and exchangeable Cd showed highly positive correlation with organic matter content but residual, organic bound, and exchangeable Cd showed negative correlations with CEC. Water soluble Pb showed positive correlation with CEC but organic bound Pb showed negative correlation with CEC.

• Journal of Environmental Science International
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• v.8 no.1
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• pp.51-59
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• 1999

Chemical composition of atmospheric aerosols was measured at 4 sites in Pusan. All the samples were collected with a high volume air sampler from January to October 1996, to analyze major ions and heavy metals. Dominant ions of aerosols were S $O_4$$^{2-}$ in anion and N $a^{+}$ in cation. Sulfate, nitrate and ammonium ions in aerosols showed high enrichment factor to soil and seawater composition. The concentrations of heavy metals in aerosols was lowest at the site PI near the coast. The lowest concentrations of major ions and heavy metals mainly appeared in August, probably due to scavenging by frequent rains. Especially, the concentrations of total suspended particulate matter(TSP) and heavy metals in aerosols showed good correlations in Pusan. Based on crustal Al, enrichment factors for some metals(Zn, Cu, Pb, Cd) in aerosols were significantly greater than unity, and the order was Cd ＞ Pb ＞ Zn ＞ Cu. This evidence suggests that Cd and Pb are derived predominantly from non-crustal sources.s.

• Journal of Animal Science and Technology
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• v.44 no.2
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• pp.213-220
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• 2002

This study was conducted to investigate the effects of feeding probiotics on the egg quality and excretal noxious gas in laying hens. One hundred forty four, 36 weeks old ISA brown commercial layer, were employed in a 28 d feeding trial with a 7 d adjustment period. Dietary treatments are 1) control(basal diet), 2) PB0.3(basal diet+0.3% probiotics), 2) PB0.6(basal diet+0.6% probiotics). For overall period, hen-day egg production, egg weight and egg shell breaking strength tended to increase (P>0.05) by dietary probiotic supplementation. Egg shell thickness was improved by supplementation of probiotics(linear effect, P$<$0.01). Diets PB0.3 and PB0.6 improved the yolk color compared to control diet(linear effect, P$<$0.02). As supplementation level of probiotics increased in the diets, egg yolk index tended to increase(linear effect, P$<$0.04). $NH_3$-N concentration in excreta fed PB0.6 diet was significantly (P$<$0.04) lower than either control or PB0.3 diet. In conclusion, supplementing probiotics to a Corn-SBM diet for laying hens increased egg shell thickness, yolk color and decreased egg yolk index, and decreased excretal $NH_3$-N concentration.

• Journal of Soil and Groundwater Environment
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• v.11 no.1
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• pp.23-36
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• 2006

Experimental leaching of tailings was performed as a function of times (1, 2, 4, 7, 14, 21 and 30 days) in the laboratory using reaction solutions equilibrated to three different pH set-points (pHs 1,3 and 5). The initial pHs of 5 and 3 stabilized at either 4.6-6.1 or 2.8-3.5 in 2 days and decrease gradually with time afterwards. The results of the leaching tests indicate that the significant increase in the sulfate concentrations and in acidity after 7 days of leaching results from the oxidation of sulfide minerals. There were no significant variations in the extractable Pb found in the leach solutions of pH 5 and 3 within the reaction time (1-30 days), while Zn, Cd and Cu concentrations tend to significantly increase with time. In tailings leaching at an initial pH=1, two trends were observed: i) The 'Zn-type' (Zn, Cd and Cu), with increasing concentrations between days 1 and 30, corresponding to the expected trend when continuous dissolution is the dominant process, ii) the 'Pb-type' (Pb), with decreasing concentrations over time, suggesting rapid dissolution of a Pb source followed by the precipitation of 'anglesite' in relation to the large increase in dissolved sulfates. The high sulfate concentrations were coupled with high concentrations of released Fe, Zn and Cd. Release of Zn and Cd and acidity from these leaching experiments can potentially pose adverse impact to surface and groundwater qualities in the surrounding environment. The kinetic problems could be the important factor which leads to increasing concentrations of trace metals in the runoff water.

• Korean Journal of Materials Research
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• v.4 no.3
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• pp.334-338
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• 1994

This report details the microscopic aspects of grain boundary cracking in Pb-Sn eutecticduring displacement-controlled mechanical tests performed over a range of low frequency ($10^{-3}-10^{-5}$/s)and moderate strain range (0.2 - 1 %) where is the most technologically relevant to solder jointssubjected to thermal cycling. It is shown that intergranular cracking begins with the appearance ofcrack-like features (CLF's), which can be seen due in part because they are associated with grainboundary sliding, and is able to be described by certain stages of isolated crack growth. In the initialstages CLF's are not ture cracks but instead what I shall call "proto-cracks" where grain boundarysliding begins to damage the gram boundary at the surface. At some point during the initiation stagesonce proto-cracks become ture cracks, they develop into isolated cracks and the growth of isolatedcracks is eventually accomplished by coalescence, resulting in 5 stages of cracking.ing in 5 stages of cracking.

• Proceedings of the KIEE Conference
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• 2000.11c
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• pp.494-496
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• 2000

The properties of piezoelectric and dielectric for 0.05Pb$(Mn_{0.4}W_{0.2}Nb_{0.4})O_3$ - $0.95PbZr_{x}Ti_{1-x}O_{3}$ compositions have been investigated. In the composition of 0.05Pb$(Mn_{0.4}W_{0.2}Nb_{0.4})O_3$-$0.95PbZr_{0.51}Ti_{0.49}O_{3}$, the values of $k_p$ and ${\varepsilon_{33}}^T/{\varepsilon}_0$ are maximized, but $Q_m$ was minimized ($k_p$=56.5[%], $Q_m$=1130, $d_{33}$=258[pC/N], ${\varepsilon_{33}}^T/{\varepsilon}_0$=1170). The grain size was suppressed and the uniformity of gram was improved at the $1100[^{\circ}C]$. Dielectric constant increase at the Ti rich, but decrease at the Zr rich after poling. Because the dielectric constant after poling is determined by compromising effects between dipole switching and electostriction inducing stress(dielectric constant increasing factor) and dipole rotation to the poling direction (dielectric constant decreasing factor).

• Journal of Korean Society for Atmospheric Environment
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• v.26 no.2
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• pp.190-201
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• 2010

Fine particulate matter < $1.8{\mu}m$ was collected as a slurry using the Semicontinuous Elements in Aerosol Sampler with time resolution of 30-min between May 23 and 27, 2002 at the Sydney Supersite, Florida, USA. Concentrations of 11 elements, i.e., Al, As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Se, and Zn, in the collected slurry samples were determined off-line by simultaneous multi-element graphite furnace atomic absorption spectrometry. Temporal profiles of $SO_2$ and elemental concentrations combined with meteorological parameters such as wind direction and wind speed indicate that some transient events in their concentrations are highly correlated with the periods when the plume from an animal feed supplement processing facility influenced the Sydney sampling site. The peaking concentrations of the elemental species during the transient events varied clearly as the plume intensity varied, but the relative concentrations for As, Cr, Pb, and Zn with respect to Cd showed almost consistent values. During the transient events, metal concentrations increased by factors of >10~100 due to the influence of consistent plumes from an individual stationary source. Also the multi-variate air dispersion receptor model, which was previously developed by Park et al. (2005), was applied to ambient $SO_2$ and 8 elements (Al, As, Cd, Cr, Cu, Fe, Pb, and Zn) measurements between 20:00 May 23 and 09:30 May 24 when winds blew from between 70 and $85^{\circ}$, in which animal feed processing plant is situated, to determine emission and ambient source contributions rates of $SO_2$ and elements from one animal feed processing plant. Agreement between observed and predicted $SO_2$ concentrations was excellent (R of 0.99; and their ratio, $1.09{\pm}0.35$) when one emission source was used in the model. Average ratios of observed and predicted concentrations for As, Cd, Cr, Pb, and Zn varied from $0.83{\pm}0.26$ for Pb to $1.12{\pm}0.53$ for Cd.