• Analytical Science and Technology
• /
• v.8 no.4
• /
• pp.511-517
• /
• 1995

A cationic water soluble porphyrin (5,10,15,20-tetrakis (l-methyl-pyridinium-4-yl)porphyrin, $H_2tmpyp^{4+}$) and its metalloporphyrins (MP) were easily extracted into acetonitrile separated by addition of sodium chloride ($4mol\;dm^{-3}$) in the presence of sodium perchlorate, where M denotes $Zn^{2+}$, $Cu^{2+}$, $Co^{3+}$, $Fe^{3+}$, and $Mn^{3+}$ and $P^{2-}$ is porphyrinate ion. The extracted ion-pair complexes were completely dissociated to $[MP(ClO_4)_3]^+$, and $[MP(ClO_4)_2]^{2+}$. The extraction and the dissociation constants were determined by taking into account of the partition constant of sodium perchlorate ($K_D=1.82{\pm}0.01$). The chemical properties of the separated acetonitrile phase as $E_{T(30)}$ and $D_{II,I}$ were determined and compared with other water miscible solvents (acetone, actonitrile, 1,4-dioxane, tetrahydrofuran, 1-propanol and 2-propanol). Furthermore, a sensitive and selective method was proposed for the determination of a subnanogram amount of copper(II) in natural water samples by using the present salting-out method and the porphyrins.

• Bulletin of the Korean Chemical Society
• /
• v.16 no.7
• /
• pp.582-588
• /
• 1995

The preconcentration and determination of trace Cd(Ⅱ), Cu(Ⅱ), Pb(Ⅱ), Mn(Ⅱ) and Zn(Ⅱ) in water samples were studied by the precipitate flotation using La(OH)3 as a coprecipitant. The analytes were quantitatively coprecipitated by adding 3.0 mL of 0.1 M La(Ⅲ) solution in a 1,000 mL water sample and adjusting the pH to 9.5 with NaOH solution. After the addition of the 1:8 mixed surfactant solution of each 0.1% sodium oleate and sodium lauryl sulfate, the solution was stirred with a magnetic stirrer for 10 minutes. The precipitates were floated to the surface by bubbling with nitrogen gas and collected in a small sampling bottle. The precipitates were dissolved in nitric acid and then the solutions were diluted to 25.00 mL with a deionized water. The analytes were determined by flame atomic absorption spectrometry. This procedure was applied to the waste water analysis. This technique was simple, convenient and especially rapid for the analysis of a large volume of sample. And also, from the recoveries of better than 92% which were obtained from real samples, this method could be judged to be applicable to the preconcentration and quantitative determination of trace elements in water samples.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2022.10a
• /
• pp.162-162
• /
• 2022

This study was carried out to investigate the effects of nitrogen, phosphorus, potassium (three main macro elements of fertilizer) on growth, yield and mineral contents of Platycodon grandiflorum for. duplux and to obtain the basic data of the proper fertilizer application for increasing the yield of P. grandiflorum for. duplux. Plant height showed significantly good results in all fertilization treatments compared to non fertilizer group (the control, T0), and in particular, the highest was 85.7 cm in the complete group (T4). Chlorophyll content showed a high amount in the range of 20.7 to 23.8 against all fertilization treatment groups, except for non fertilizer (T0) and non nitrogen (T1). The fresh weight of roots were higher quantity than other fertilization treatments in the complete group 55.8 g (T4). The mineral nutrient content ofNa, Mg, Cu and Al of the roots of P. grandiflorum for. duplux from T1 group showed the lowest amount compared to other groups. In addition, P from T2 group, Mn from T3 group and Ca, Fe, Zn from T4 group also exhibited the lowest mineral content compared to other groups respectively.

• Archives of Metallurgy and Materials
• /
• v.66 no.4
• /
• pp.983-986
• /
• 2021

This study investigated the recovery behavior of valuable metals (Co, Ni, Cu and Mn) in spent lithium ion-batteries based on Al₂O₃-SiO₂-CaO-Fe₂O₃ slag system via DC submerged arc smelting process. The valuable metals were recovered by 93.9% at the 1250℃ for 30 min on the 20Al₂O₃-40SiO₂-20CaO-20Fe₂O₃ (mass%) slag system. From the analysis of the slag by Fourier-transform infrared spectroscopy, it was considered that Fe₂O₃ and Al₂O₃ acted as basic oxides to depolymerize SiO₄ and AlO₄ under the addition of critical 20 mass% Fe₂O₃ in 20Al₂O₃-40SiO₂-CaO-Fe₂O₃ (CaO + Fe₂O₃ = 40 mass%). In addition, it was observed that the addition of Fe₂O₃ ranging between 20 and 30 mass% lowers the melting point of the slag system.

• Journal of the Semiconductor & Display Technology
• /
• v.16 no.2
• /
• pp.44-48
• /
• 2017

We explain optical and electrical properties of top and bottom-emission structured alternating-current powder electroluminescent devices (ACPELDs) with Ga-doped ZnO(GZO) transparent electrode. The top-emission ACPELDs were layered as the metal electrode/dielectric layer/emission layer/top transparent electrode and the bottom-emission ACPELDs were structured as the bottom transparent electrode/emission layer/dielectric layer/metal electrode. The yellow-emitting ZnS:Mn, Cu phosphor and the barium titanate dielectric layers were layered through the screen printing method. The GZO transparent electrode was deposited by the sputtering, its sheet resistivity is $275{\Omega}/{\Box}$. The transparency at the yellow EL peak was 98 % for GZO. Regardless of EL structures, EL spectra of ACPELDs were exponentially increased with increasing voltages and they were linearly increased with increasing frequencies. It suggests that the EL mechanism was attributed to the impact ionization by charges injected from the interface between emitting phosphor layer and the transparent electrode. The top-emission structure obtained higher EL intensity than the bottom-structure. In addition, charge densities for sinusoidal applied voltages were measured through Sawyer-Tower method.

• Journal of Korean Society of Environmental Engineers
• /
• v.29 no.7
• /
• pp.793-800
• /
• 2007

A total of 48 samples of street dust were collected in Daegu area during April and May 2006, were sieved below 100 ${\mu}m$, and analysed by ICP for the analysis of 14 elements after an acid extraction. Results obtained from the source assessment of trace elements using enrichment factor showed that Ca, Fe, K, Mg, Mn, Na and V were influenced by natural sources such as soil and dust, while Cd, Cr, Cu, Ni, Pb and Zn were influenced by urban anthropogenic sources such as fuel combustion and waste incineration. The measured values were remarkably higher in components from natural sources than in components from urban anthropogenic sources. The concentrations of trace elements in Daegu area were generally higher than in other foreign cities. Samples originated from industrial and commercial areas had higher concentrations of trace elements and pollution indices of heavy metals than those from residential and green areas. The correlation analysis among trace elements indicated that the correlations among components from urban anthropogenic sources were much significant, while those among components from natural sources were less correlated. In addition there were significant correlations between traffic density and components from urban anthropogenic sources.

• Nutritional Sciences
• /
• v.4 no.2
• /
• pp.79-84
• /
• 2001

The influence of Rhodiola extract on tissue antioxidant status, plasma lipid levels, cholesterol contents of liver and fores were investigated in rats find oxidized linoleic acid. Groups of five-week old male Sprague-Dawley rats fed ad libitum with a diet containing 20% oxidized linoleic acid with or without 300 mg/kg body weight freeze-dried Rhodiola water extract. The antioxidant effect of dietary Rhodiola extract supplementation on the peroxidation potential of rats was investigated. The microsomal thiobarbiruric acid reactive substance (TBARS) contents were changed significantly by Rhodiola extract supplementation. Hepatic Catalase activities were increased in Rhodiola supplemented rats, whereas hepatic Manganese Superoxide Dismutase (MnSOD) or Copper Zinc Superoxide Dismutase (CuZnSOD) were not elevated. In addition, plasma cholesterol lowering effect was observed along with the stimulated excretion of cholesterol through the feces were observed with Rhodiola feeding. Supplementation with Rhodiola extract did not alter high density lipoprotein (HDL) cholesterol. These results support that Rhodiola extract may be effective in protection against oxidative stress, and prevention and treatment of blood dyslipidemia. It demonstntes that Rhodiola extract has a potential to exert anti-atherogenic properties antioxidative capacities .

• The Korean Journal of Mycology
• /
• v.38 no.2
• /
• pp.152-159
• /
• 2010

The influence of urushiol, as an allergen on laccase property of Fomitella fraxinea was investigated. The enzyme production was reached to the highest level after 10 days, cultivation and the activity and mycelial biomass were increased by 2.5 and 1.5 folds, respectively, by adding urushiol in the culture medium. In liquid cultures using a Cu Mn-free medium, laccase lactivity was decreased by 3.8-9.2 folds, with similar dry cell weight. Two isoenzymes, were purified using anion exchange, hydrophobic interaction and size-exclusion chromatographies. Both isoenzymes are monomeric proteins, with $M_W$ around 67 kDa(Lac1) and 66 kDa(Lac2), and isoelectric points of 3.67 and 3.81. The optimal conditions for purified isoenzymes were found to be pH 4.5-5.0 and $30-35^{\circ}C$. Activity decreased by the addition of $Fe^{2+}$, $Mg^{2+}$, $Na^+$, and strongly inhibited by EDTA and sodium azide.

• Ocean and Polar Research
• /
• v.28 no.3
• /
• pp.215-224
• /
• 2006

Spatial variation of heavy metal accumulation was investigated in Manila clam Ruditapes philippinarum collected from several tidal flats. Sediment metal levels varied highly among the sites, which was attributed primarily to differences in Fe and organic carbon contents and in part to gain size. Significant differences in metal concentrations also were found in the clam tissue among the different sampling sites. However, except for a few metals (Mn, Zn, Pb), which showed some elevation, the variations in the clam tissue were not related to the variations in the sediment. This is likely because most metals in filter-feeding herbivores such as R. philippinarum accumulated as a result of feeding on suspended particles such as phytoplankton and organic detritus in the water column, not in bottom sediment. In addition, tissue weight for a specific shell size varied significantly among the sites, and increased tissue mass indicating a good nutritive condition likely caused a subsequent dilution of body metals leading to reduced weight-specific concentrations of some metals (Cd, Zn, Cu, Co).

• Journal of the Korean Society for Environmental Technology
• /
• v.19 no.6
• /
• pp.586-599
• /
• 2018

To learn about the discharge facility management of industrial complexes and the discharge characteristics of water pollutants in drainage, 11 sites were selected, including 16 discharge companies of Hanam Industrial Complex and High-Tech Scientific Industrial Complex and 4 drainages of the industrial complexes. Through the analysis, it was found that 12(75 %) of the 16 discharge companies had specific hazardous substances other than those registered at the time of installation and registration of the wastewater discharge facilities. In terms of other pollutants, 11 of the 16 companies(about 69 %) were found to have pollution items that differed from those included in approved and reported items lists. In addition, Formaldehyde, Mn, Zn, and Ba were discharged from 11 out of the 16 companies. Significantly, one of the specific hazardous water pollutants, Cu, was detected in all discharge facilities at levels from 0.029 to 0.929 mg/L. Even in major complexes drainages and the main stream of the Yeongsangang. As, Dichloromethane, and Chloroform were detected. However, it cannot be conclusively claimed that it is probable that these substances were actually discharged from the above facilities because research was only done in a limited range(Class 1 to Class 3), and therefore, further research is required. In the future, it will be necessary to expand the research scope of the discharge companies in order to establish a database of water pollutants, and to improve permits and reported items based on discharged substances.