• Resources Recycling
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• v.12 no.1
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• pp.25-32
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• 2003

A study on the separation of heavy metals such as iron, copper, zinc and nickel from electroplating waste water has been investigated. The results showed that the PC-88A was more effective extractant for the extraction of zinc and the efficiency of zinc was to be about 100% at pH 2.5. And copper and nickel were extracted about 100% at pH 2 and more than 90% at pH 4～5 with LIX 84, respectively. On the other hand, in the case of solvent extraction of electroplating waste water(Acid-Alkali type) containing heavy metals, the ferric ion was first extracted at pH 2∼2.5 with 20% Naphthenic acid or 10% Versatic acid-10. And then, copper and zinc were extracted at pH 2 with 3% LIX 84 and at pH 2.5∼3 with 20% PC-88A respectively, remaining nickel in the raffinate. In this manner, the heavy metals in electroplating waste water could be effectively separated with solvent extraction method.

• Journal of Veterinary Science
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• v.22 no.3
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• pp.31.1-31.12
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• 2021

Background: Blackened intestines in slaughtered pigs have been commonly observed in China in recent years. However, no cause has been reported. Objectives: We attempted to determine whether the blackening of the pig intestine was related to an excess of copper (Cu) in their feed. Methods: In this study, we observed and collected porcine intestines in small- and large-scale pig slaughterhouses in Shandong province from May to October 2018. Twelve types of metal ions were detected in the black intestinal samples. Results: The Cu level in the intestine samples was mostly higher than the Chinese national limit for food. Further study showed that Cu supplementation in most commercial porcine feed also exceeded the national standard. An animal model (mouse) that could mimic the intestinal blackening in pigs was established. Compared to control mice, Cu accumulated in the liver and intestines of mice fed an excessive Cu level, confirming the excessive Cu in the feed may be considered the major cause of blackened porcine intestines. Microscopic examination revealed that black intestines had many particles containing Cu in the lamina propria of the intestinal mucosa, and the intestinal mucosal epithelial cells showed degeneration and necrosis. Conclusions: In conclusion, overuse of Cu in animal feed can lead to animal poisoning and Cu accumulation in animal products. Such overuse not only harms the health of livestock but can also affect public health.

• Resources Recycling
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• v.28 no.2
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• pp.31-39
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• 2019

The pelletizing of printed circuit board (PCB) sludge was researched for copper recovery in pyrometallurgical process. This pelletizing was carried out by using self-manufactured compression-type apparatus after pre-treatments (drying, water scrubbing, size classification) were proceeded. The physical properties (compression strength and drop-breakage test) were tested with a change of sludge sizing and the number of compression. In the case of using the undersized sludge of #140, its properties were improved to 0.6 MPa and 9.3 times. Moreover, they increased to 0.82 MPa and 19.0 times by using the #140 ~ 325 sludge. These imply that the packing density increases due to the elimination of large-sized sludge (#140), and also the weight of required binder decreases by the removal of fine-sized sludge (#325).

• Korean Journal of Materials Research
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• v.29 no.1
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• pp.37-42
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• 2019

This study investigates Ag coated $Cu_2O$ nanoparticles that are produced with a changing molar ratio of Ag and $Cu_2O$. The results of XRD analysis reveal that each nanoparticle has a diffraction pattern peculiar to Ag and $Cu_2O$ determination, and SEM image analysis confirms that Ag is partially coated on the surface of $Cu_2O$ nanoparticles. The conductive paste with Ag coated $Cu_2O$ nanoparticles approaches the specific resistance of $6.4{\Omega}{\cdot}cm$ for silver paste(SP) as $(Ag)/(Cu_2O)$ the molar ratio increases. The paste(containing 70 % content and average a 100 nm particle size for the silver nanoparticles) for commercial use for mounting with a fine line width of $100{\mu}m$ or less has a surface resistance of 5 to $20{\mu}{\Omega}{\cdot}cm$, while in this research an Ag coated $Cu_2O$ paste has a larger surface resistance, which is disadvantageous. Its performance deteriorates as a material required for application of a fine line width electrode for a touch panel. A touch panel module that utilizes a nano imprinting technique of $10{\mu}m$ or less is expected to be used as an electrode material for electric and electronic parts where large precision(mounting with fine line width) is not required.

• Journal of Life Science
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• v.13 no.4
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• pp.421-427
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• 2003

A natural habit at bacterium, Enterobacter intermedious KH410 was isolated from freshwater plant root and identified. Adsorption of heavy metals such as lead, cadmium, and copper by this strain was examined. The minimal inhibitory concentrations(MIC) for each metal were 1.78 mM for lead, 0.17 mM for cadmium and 1.39 mM for lopper, respectively. Maximum production of dried cell was 2.56 g/$\ell$ in LB medium containing 0.5% NaCl, 1% yeast extract and 1% of lactose. Optimal conditions for adsorption were 0.6 dry g-biomass, at pH 4.0 and the temperature of $20^{\circ}C$. Adsorption equilibrium reached maximum after 30 min in 400 mg/$\ell$ metal solution. The adsorption capacity (K) of copper was 1.5 times higher than that of cadmium and lead was 1.1 times higher than that of cadmium. from the results obtained in this study, Freundlich adsorption model was applicable for all metals. Adsorption strength (1/n) of heavy metal ions were in the order of cadmium>copper>lead. The adsorption of dried cell for lead, cadmium, and copper was 56.2, 58.0, 55.8 mg/g-biomass, respectively. Pretreatment to increase ion strength was the most effective with 0.1 M NaOH whereas slight difference was found both KOH and $CaCl_2$ upon same concentration. Effective desorption was induced by 0.1 M EDTA for lead and 0.1 M $HNO_2$ for cadmium and copper.

• The Journal of the Korea Contents Association
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• v.20 no.6
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• pp.425-432
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• 2020

For this study copper ions-containing bioactive glass nanoparticles commonly used in mineral trioxide aggregate (MTA) was developed to improve the mechanical properties and promote antibacterial effect of MTA with the original material. The mechanical properties and antibacterial activity of Cu-BGn incorporating varying amounts cooper incorporated bioactive glass nano particles(BGn) 0.5,1.0,2.0 and 4.0 wt% in MTA were characterized composition of the resulting were investigated. The compressive strength was calculated by weighing specimens with a diameter of 4 mm and a thickness of 6 mm according to ISO 6876 (2012). The antimicrobial effect was evaluated using two strains of S. mutans and E. faecalis. The mechanical properties of the test results was Cu-BGn increased no statistically significant difference was observed (p>0.05). Adhesion experiment results S. mutans in contrast to the control group Ortho MTA, 4.0 wt% of Cu-BGn added experimental group showed a significant difference was observed (p<0.05). Also, E. faecalis statistical analysis indicated a significant difference for antibacterial agents between control and Cu-BGn containing(p<0.05). It seems that this Cu-BGn proved that even a antibacterial effect was demonstrated. Therefore, it was suggest that it is necessary for in-depth research into various environments that can reproduce the oral environment.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.12
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• pp.1734-1740
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• 2001

Feeding trials using weanling pigs and broiler chicks were conducted to evaluate the efficacy of different metal-amino acid chelates and complexes at various levels of copper and zinc on the performance and fecal excretions. A total of 200 weanling pigs (Large White ${\times}$ Yorkshire ${\times}$ Duroc, $11.20{\pm}0.81kg$) were randomly assigned to 5 dietary treatments following a randomized complete block design. Each treatment was replicated 4 times with 10 pigs per pen. The dietary treatments were designated as : A-diet containing 170 ppm Cu from $CuSO_4$ and 120 ppm Zn from $ZnSO_4$, B-diet containing 85 ppm Cu from Cu-amino acid chelate (CAC) and 60 ppm Zn from Zn-amino acid chelate (ZAC), C-diet containing 170 ppm Cu from CAC and 120 ppm Zn from ZAC, D-diet containing 85 ppm Cu from Cu-lysine complex (CL) and 60 ppm Zn from Zn-methionine complex (ZM), and E-diet containing 170 ppm Cu from CL and 120 ppm Zn from ZM. On the other trial, 144 of one day old broiler chicks were randomly distributed to 6 dietary treatments following a completely randomized design. Each treatment was replicated 3 times with 8 chicks per replicate. The dietary treatments were as follows: 1-diet with 60 ppm Cu from $CuSO_4$ and 40 ppm Zn from $ZnSO_4$, 2-diet with 120 ppm Cu from $CuSO_4$ and 80 ppm Zn from $ZnSO_4$, 3-diet with 60 ppm Cu from CAC and 40 ppm Zn from ZAC, 4-diet with 120 ppm Cu from CAC and 80 ppm Zn from ZAC, 5-diet with 60 ppm Cu from CL and 40 ppm Zn from ZM, and 6-diet with 120 ppm Cu from CL and 80 ppm Zn from ZM. In Exp. 1 with pigs, there was no difference on average daily gain and average daily feed intake observed among treatments. There was improvement (p<0.05) on the overall feed conversion ratio (FCR) of pigs fed diet containing 120 ppm Zn and 170 ppm Cu from metal-amino acid chelates relative to those fed diet containing inorganic sources of Cu and Zn but equally efficient as those fed diet containing metal-amino acid complexes. Pigs fed diet containing either metal-amino acid chelates or complexes as sources of Cu and Zn had higher (p<0.05) Cu and Zn concentration in serum and lower (p<0.05) in feces than those receiving diet with inorganic sources. In Exp. 2 with broiler chicks, the overall FCR was not different among treatments. Higher (p<0.05) Cu and Zn concentration in serum was obtained from birds fed diet with 60 ppm Cu and 40 ppm Zn from metal-amino acid chelates compared to those fed diet with inorganic sources of Cu and Zn. Also, the feces collected from birds fed diet with either metal-amino acid chelates or complexes contained generally lower Cu and Zn than those birds fed diet with inorganic sources. The higher the dietary level of Cu and Zn the higher the Cu and Zn concentration in the feces. Based on the results, both metal-amino acid chelates and complexes of Cu and Zn at low levels (Zn 60 ppm, Cu 85 ppm for weanling pigs and Zn 40 ppm, Cu 60 ppm for broiler chicks) are not different from that of high levels of inorganic sources in maintaining growth performance and serum concentration. The fecal excretions for Cu and Zn were greatly reduced when organic sources were used.

• Journal of Life Science
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• v.18 no.1
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• pp.9-15
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• 2008

Sulfur containing compounds in garlic have all be used as one of the traditional folk medicine as well as food source. The present study was performed to investigate the antioxidative compounds of 1-methyl-1-cysteine, dimethyl trisulfide and 2-vinyl-4H-1,3-dithiin. The antioxidative activity of sulfur containing compounds on human LDL was investigated by monitoring a thiobarbituric acid substances (TBARS). Sulfur containing compounds inhibited on oxidation of LDL mediated by $CuSO_4$ and macrophages in dose dependent manner with almost completely inhibition at $80{\mu}g/ml$. Antioxidant activities of sulfur containing compounds on LDL oxidation were 2-vinyl-4H-1,3-dithiin, 1-methyl-1-cysteine, and dimethyl trisulfide in order. Inhibitory effects of sulfur containing compounds on oxidation of LDL mediated by $CuSO_4$ and macrophages were degraded at much greater rate than native LDL, the LDL oxidation process was arrested as shown by the lower conjugated dienes formation at the concentration of $60{\mu}g/ml$. Sulfur containing compounds in garlic revealed at high antioxidative activity at low physiological concentration for human LDL oxidation in vitro specially, it was indicated that the antioxidative activity of 3-viny l-4H-1,2-dithiin was higher than that of the other sulfur containing compounds.

• Progress in Superconductivity and Cryogenics
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• v.19 no.1
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• pp.22-25
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• 2017

Steel slag has been considered as an industrial waste. A huge amount of slag is produced as a byproduct and the steel slag usually has been dumped in a landfill site. However the steel slag contains valuable resources such as iron, copper, manganese, and magnesium. Superconducting magnetic separation has been applied on recovery of the valuable resources from the steel slag and this process also has intended to reduce the waste to be dumped. Cryo-cooled Nb-Ti superconducting magnet with 100 mm bore and 600 mm of height was used as the magnetic separator. The separating efficiency was evaluated in the function of magnetic field. A steel slag was ground and analyzed for the composition. Iron containing minerals were successfully concentrated from less iron containing portion. The separation efficiency was highly dependent on the particle size giving higher separating efficiency with finer particle. The magnetic field also effects on the separation ratio. Current study showed that an appropriate grinding of slag and magnetic separation lead to the recovery of metal resources from steel slag waste rather than dumping all of the volume.

• Journal of environmental and Sanitary engineering
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• v.24 no.3
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• pp.28-36
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• 2009

We have closely examined the concentration change characteristics, emission amounts, and the material balance of hazardous air pollutants at both early and later stages of the prevention facilities. These results will be uses as the basic data when preparing for the regulatory and management plans for hazardous air pollutants. The results of the study on heavy metals illustrated that the content of heavy metals in sludge across five facilities were as follows: copper> zinc> chrome> nickel> cadmium> mercury. In terms of heavy metal content in swage sludge, the sludge in incinerating facilities other than the sludge in the D incinerating facility containing industrial water waste, was examined in order to satisfy the ocean contamination standard and fertilizer specifications. Most of the items were shown to have satisfied the emission tolerance standards in the latter part of the prevention facilities(The average elimination rate was over 90%). Therefore, it is concluded that swage sludge containing high-concentrate heavy metals needs to be incinerated rather than recycled as fertilizer.