• Journal of the Korean Society of Clothing and Textiles
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• v.26 no.5
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• pp.582-593
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• 2002

Metal materials have been used in the clothing design on the spirit of ingenious experiment by fashion designers, and they have been put to practical use by several designers who work out a scheme of popular fashion merchandise. This current starting from the 1960s was weakened in the 1980s, but it was appeared with various shapes of metal materials in the 1990s due to a popularity of techno/cyber fashion. Recently, textile engineering technology causes to develop new-materials which are practical and sanitary. The development of fashionable metal materials brings about the popularization of fashion with metal materials, and it induces that mainstream of modem fashion has been changed into designers of pursuing the spirit of ingenious experiment. This study examines the formative characteristics of metal materials that are based on the spirit of ingenious experiment. As a result, it is evaluated that the formative of metal materials shown in modern fashion is futurism, visual concentration, avast-garde, resistance, precious.

• Journal of Preventive Medicine and Public Health
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• v.31 no.4 s.63
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• pp.666-679
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• 1998

This study aims at providing the fundamental data on the field of cosmetics by comparing heavy metal concentration in terms of domestic/foreign products, items, companies and colors. This study has determined the concentration of chromium, lead, mangagnese, nickel, copper and vanadium in cosmetics such as moisturizer, concealer, foundation (Ivory-yellow), compact powder (Ivory-yellow), lip colo. (Red, brown), eye shadow (Red, brwon and dark green) and eye liner (Black) manufactured by five domestic cosmetic companies and five foreign cosmetic companies on the market. The samples have been collected in cosmetic stores in Pusan from Dec. lst 1996 to Jan. 3lst 1997. The results are as follows : 1. The heavy metal concentration in cosmetics was $2.420{\mu}g/g$ for chromium, $0.82{\mu}g/g$ for lead, $4.49{\mu}g/g$ for manganese, $1.69{\mu}g/g$for nickel, $0.53{\mu}g/g$ for copper, and $51{\mu}g/g$ for vanadium, respectively. 2. Lead and vanadium concentration were significantly higher in domestic cosmetics than foreign cosmetics(p<0.05). 3. The mean(GM) concentrations of heavy metal were different significantly (p<0.01) when classified with cosmetic items. The highest means shown at eye shadow in $Cr(14.96{\mu}g/g),\;Cu(1.32{\mu}g/g),\;V(1.28{\mu}g/g),\;and\;Ni(8.30{\mu}g/g)$, compact powder in $Pb(2.50{\mu}g/g)$, eye liner in $Mn(90.62{\mu}g/g)$. 4. The mean(GM) concentrations of heavy metal were different significantly (p<0.01) among colored cosmetics. The highest mean concentration of Cr, Ni, Cu and V were dark green-colored cosmetics, that of Mn was black-colored cosmetics, and that of Pb was ivory yellow- colored cosmetics.

• Journal of Korean Society on Water Environment
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• v.20 no.4
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• pp.307-312
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• 2004

This study was focused on experiment for the separation and concentration process of Cu(II), Zn(II) solution with the variation of applied pressure and concentration using reverse osmosis plate and frame modules. Rejection coefficient and degree of concentration for Cu(II) component using single and multi-stage reverse osmosis process were showed 96.3~97.8%, 0.044~0.191(in single-stage), 96.3~98.4%, 0.400~2.264(in multi-stage) within the range of experimental condition, respectively. Those of Zn(II) were 93.3~97.1%, 0.019~0.395(in single-stage), 96.3~98.2%, 0.365~1.454(in multi-stage), respectively. Degree of concentration of multi-stage were higher than those of single-stage. Heavy metal[Cu(II), Zn(II)] separation was very efficient in using reverse osmosis plate and frame type modules. Separation efficiency for a mixed solution Cu(II) and Zn(II) was higher than those of each one of Cu(II) and Zn(II).

• Korean Journal of Environmental Biology
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• v.30 no.3
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• pp.238-244
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• 2012

Toxic effects of heavy metal (Pb, Cr, As) were examined by the hatching rates of fertilized eggs in the oliver flounder, Paralichthys olivaceus. Eggs were exposed to Pb, Cr, As (0, 10, 100, 500, 1,000, 2,500, 5,000 ppb) and then normal hatching rates were investigated after 48 h. The normal hatching rates in the control condition (not including heavy metal) were greater than 80%, but suddenly decreased with increasing of heavy metal concentrations. Pb, Cr and As reduced the normal hatching rates in concentration-dependent way and a significant reduction occurred at concentration grater than 100, 100, 500 ppb, respectively. The ranking of heavy metal toxicity was Cr>As>Pb, with $EC_{50}$ values of 415, 518 and 1,029 ppb, respectively. The no-observed-effect-concentration (NOEC) and lowest-observed-effect-concentration (LOEC) show each 100 bbp and 500 ppb of normal hatching rates in exposed to Pb and As. The NOEC and LOEC of normal hatching rates in Cr were 10 ppb and 100 ppb, respectively. From these results, the normal hatching rates of P. olivaceus have toxic effect at greater than the 100 ppb concentrations in Pb, As and the 10 ppb concentrations in Cr in natural ecosystems. These results suggest that biological assay using the normal hatching rates of P. olivaceus are very useful test method for the toxicity assessment of a toxic substance as heavy metal in marine ecosystems.

• Journal of Environmental Impact Assessment
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• v.5 no.2
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• pp.21-31
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• 1996

To assess the impact resulted from the slag dumping, we studied that the changes in the concentration of heavy metal were researched through the statistic analysis at 4 stations in Yongil bay, Korea from 1988 to 1995. And in order to clarify resulting from the changes in heavy metal concentration due to be leaked out from dumped slag, it was fulfilled experiments of the slag extraction. In the extracting experiment, Pb and As were only leaked out from slag aged during 10 days but all of heavy metals were not from it aged during 90 or 180 days. It was found that the concentrations of heavy metals in sea water of vincinity of slag dumping area were still remained in similar, comparing with it of control site(site 4) when they were by analysed statistic method, anova test and Mann-Whitney test. The slag recycling ratio of our country is lower than foreign country. While we need to apply a new process for phosphate treatment, foreign country already apply a slag to phosphorous removal. We suggest that slag dumping cannot putatively affected the changes in the concentration of heavy metal. And we thought that impact of heavy metal induced by slag dumping was not severe. So, it is necessary to utilize this process in phosphorous removal, like a foreign country.

• Advances in nano research
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• v.5 no.4
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• pp.359-372
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• 2017

Metallic copper nanoparticles were synthesised by reduction of copper ions in aqueous solution, and metal-metal bonding by using the nanoparticles was studied. A colloid solution of metallic copper nanoparticles was prepared by mixing an aqueous solution of $CuCl_2$ (0.01 M) and an aqueous solution of hydrazine (reductant) (0.2-1.0 M) in the presence of 0.0005 M of citric acid and 0.005 M of n-hexadecyltrimethylammonium bromide (stabilizers) at reduction temperature of $30-80^{\circ}C$. Copper-particle size varied (in the range of ca. 80-165 nm) with varying hydrazine concentration and reduction temperature. These dependences of particle size are explained by changes in number of metallic-copper-particle nuclei (determined by reduction rate) and changes in collision frequency of particles (based on movement of particles in accordance with temperature). The main component in the nanoparticles is metallic copper, and the metallic-copper particles are polycrystalline. Metallic-copper discs were successfully bonded by annealing at $400^{\circ}C$ and pressure of 1.2 MPa for 5 min in hydrogen gas with the help of the metalli-ccopper particles. Shear strength of the bonded copper discs was then measured. Dependences of shear strength on hydrazine concentration and reduction temperature were explained in terms of progress state of reduction, amount of impurity and particle size. Highest shear strength of 40.0 MPa was recorded for a colloid solution prepared at hydrazine concentration of 0.8 M and reduction temperature of $50^{\circ}C$.

• Environmental Engineering Research
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• v.12 no.1
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• pp.16-20
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• 2007

Toxicity of metal plating wastewater was evaluated by using acute toxicity tests on Daphnia magna. To identify toxicants of metal plating wastewater, several manipulations such as solid phase extraction (SPE), ion exchange and graduated pH adjustment were used. The SPE test had no significant effect on baseline toxicity, suggesting absence of toxic non-polar organics in metal plating wastewater. However, anion exchange largely decreased the baseline toxicity by 88%, indicating the causative toxicants were inorganic anions. Considering high concentration of chromium in metal plating wastewater, it is thought the anion is Cr(VI) species. Graduated pH test showing independence of the toxicity on pH change strongly supports this assumption. However, as revealed by toxicity confirmation experiment, the initial toxicity of metal plating wastewater (24-h TU=435) was not explained only by Cr(VI) (24-h TU = 725 at $280\;mg\;L^{-1}$). Addition of nickel($29.5\;mg\;L^{-1}$) and copper ($26.5\;mg\;L^{-1}$) largely decreased the chromium toxicity up to 417 TU, indicating antagonistic interaction between heavy metals. This heavy metal interaction was successfully predicted by an equation of 24-h $TU\;=\;3.67\;{\times}\;\ln([Cu]\;+\;[Ni])\;+\;79.44$ at a fixed concentration of chromium.

• Journal of the Korean GEO-environmental Society
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• v.19 no.3
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• pp.15-24
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• 2018

As electromagnetic waves are affected by electrical conductivity or permittivity, they are widely used to evaluate geotechnical characteristics. In this study, a probe for measuring electromagnetic waves using a time domain reflectometry is manufactured to evaluate heavy metal concentration in saline water. In the experiments, a copper is used as a heavy metal, and a probe is demonstrated with the concentration of copper. Solutions were set for 8 different copper concentration (0, 0.01, 0.05, 0.1, 0.5, 1, 5, 10 mg/L) in saline water with 3% salinity. The probe is coated by electrical insulating materials such as epoxy, top-coat, varnish, acrylic paint, heat-shrinkage tube to measure electromagnetic waves in saline water. The measured signals are compared according to coating material. As results, for probes coated with acrylic paint and heat-shrinkage tube, signal variation is not detected. For epoxy, top-coat, and varnish coated probes, the voltage decreases with an increase of copper concentration. Probes coated by epoxy at once and top coat can estimate under 5 mg/L of copper concentration and the probe coated by epoxy twice can estimate over 5 mg/L of copper concentration. This study shows that the probe using the time domain reflectometry can be used to evaluate the concentration of heavy metal in saline water by coating the probe with insulating material.

• Korean Journal of Environmental Agriculture
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• v.16 no.2
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• pp.124-129
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• 1997

This study was performed to develop the biological treatment technology of wastewater polluted with heavy metals. Heavy metal-tolerant microorganisms, such as Pseudomonas putida, P. aeruginosa, P. chlororaphis and P. stutzeri possessing the ability to accumulate cadmium, lead, zinc and copper, respectively, were isolated from industrial wastewater and mine wastewater polluted with various heavy metals. The effect of several external factors, such as temperature, pH and heavy metal compounds on heavy metal accumulation in the cells was investigated. The amount of heavy metal accumulation into cells according to the kind of heavy metal compound was slightly increased in the case of the heavy metal compound with -nitrate group, but generally, there is little change according to the kind of compound in the amount of heavy metal accumulation. The amount of heavy metal accumulation according to the precultured time was increased in the case of the cell precultured for 24 hours, but generally the precultured time did not affect to the amount of heavy metal accumulation. Heavy metal accumulation into cells was affected by several external factors, such as temperature and pH. The optimum temperature and optimum pH of the accumulation of heavy metal into cells were $20{\sim}37^{\circ}C$ and pH $6{\sim}8$, respectively. By increasing the concentration of each heavy metal-tolerant microorganism in the solution, the total amount of heavy metal accumulated was increased, whereas the amount of heavy metal accumulated per cell(mg, heavy metal/g, dry cells) was decreased. These results indicated that the amount of heavy metal accumulated was not proportional to the concentration of microorganisms.

• Journal of Korean Society of Water and Wastewater
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• v.18 no.5
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• pp.573-579
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• 2004

Electroflotation, which is used as an alternative to sedimentation, is a separation treatment process that uses small bubbles to remove low-density particulates. Making allowances for recent collision efficiency diagram based on trajectory analysis, it is necessary to tailor zeta potential of bubbles that collide with negatively charged particles. In this paper, the study was performed to investigate the effects of magnesium and aluminium ions on zeta potential of bubbles. And, it was studied to find out factors which could affect the positively charged bubbles. Consequently, zeta potential of bubbles increased both with higher concentration of metal ions and in the acidic pH value. And, a probable principle that explained the procedure of charge reversal could be a combined mechanism with both specific adsorption of hydroxylated species and laying down of hydroxide precipitate. It also depended on the metal ion concentration in the solution to display its capacity to control the bubble surface.