• Journal of Environmental Health Sciences
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• v.1 no.1
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• pp.21-27
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• 1974

This work was carried out to investigate the chemical properties of the chelate compounds which were produced with 2-methoxy-5-nitrophenol(MNG) and metal salt such as copper nitrate and manganese nitrate. And obtained results were as in the followings. 1) The binding ratio of the chelate compounds formation were determined by using the molar ratio concentration method and their chemical structures were identified by IR-spectrum. 2) In the absorbance measuring, 2-methoxy-5-nitrophenol coordinated with manganese and copper showed the maximum absorbance at $430 m\mu$ and $410 m\mu$ respectively. 3) The binding ratio of chelated compounds were measured by molar ratio method and continuous variation method with spectrophotometer, which was identified as 1:2. 4) The conditional formation constant(log Kn value) of manganese and copper chelate compounds were 6.70, 6.75, respectively according to the equation of $log\frac{A-AM\circ n MNG}{AMm MNG-A}=n log (M\circ)+log Kn$ 5) The dissociations degree of manganese and copper chelate compound were $2, 300{\times} 10^{-7}$, $2, 346{\times} 10^{-7}$ respectively according to the molar calculation method.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.67 no.1
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• pp.41-52
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• 2022

As a cultivar of Korean wheat, 'Keumgang' wheat variety has a fast growth period and can be grown stably. Hexaploid wheat (Triticum aestivum) has moderately high salt tolerance compared to tetraploid wheat (Triticum turgidum L.). However, the molecular mechanisms related to salt tolerance of hexaploid wheat have not been elucidated yet. In this study, the candidate genes related to salt tolerance were identified by investigating the genes that are differently expressed in Keumgang variety and examining salt tolerant mutation '2020-s1340.'. A total of 85,771,537 reads were obtained after quality filtering using NextSeq 500 Illumina sequencing technology. A total of 23,634,438 reads were aligned with the NCBI Campala Lr22a pseudomolecule v5 reference genome (Triticum aestivum). A total of 282 differentially expressed genes (DEGs) were identified in the two Triticum aestivum materials. These DEGs have functions, including salt tolerance related traits such as 'wall-associated receptor kinase-like 8', 'cytochrome P450', '6-phosphofructokinase 2'. In addition, the identified DEGs were classified into three categories, including biological process, molecular function, cellular component using gene ontology analysis. These DEGs were enriched significantly for terms such as the 'copper ion transport', 'oxidation-reduction process', 'alternative oxidase activity'. These results, which were obtained using RNA-seq analysis, will improve our understanding of salt tolerance of wheat. Moreover, this study will be a useful resource for breeding wheat varieties with improved salt tolerance using molecular breeding technology.

• Bulletin of the Korean Chemical Society
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• v.32 no.3
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• pp.829-835
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• 2011

A dispersive liquid-liquid microextraction based on solidification of floating organic droplet (DLLME-SFO) has been developed as a new approach for the extraction of trace copper in water and beverage samples followed by the determination with flame atomic absorption spectrometry. In the DLLME-SFO, 8-hydroxy quinoline, 1-dodecanol, and methanol were used as chelating agent, extraction solvent and dispersive solvent, respectively. The experimental parameters related to the DLLME-SFO such as the type and volume of the extraction and dispersive solvent, extraction time, sample volume, the concentration of chelating agent and salt addition were investigated and optimized. Under the optimum conditions, the enrichment factor for copper was 122. The method was linear in the range from 0.5 to $300\;ng\;mL^{-1}$ of copper in the samples with a correlation coefficient (r) of 0.9996 and a limit of detection of $0.1\;ng\;mL^{-1}$. The method was applied to the determination of copper in water and beverage samples. The recoveries for the spiked water and beverage samples at the copper concentration levels of 5.0 and $10.0\;ng\;mL^{-1}$ were in the range between 92.0% and 108.0%. The relative standard deviations (RSD) varied from 3.0% to 5.6%.

• Korean Journal of Materials Research
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• v.23 no.12
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• pp.695-701
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• 2013

To understand how reactivity between reinforcing nanoparticles and aqueous solution affects electrodeposited Cu thin films, two types of commercialized cerium oxide (ceria, $CeO_2$) nanoparticles were used with copper sulfate electrolyte to form in-situ nanocomposite films. During this process, we observed variation in colors and pH of the electrolyte depending on the manufacturer. Ceria aqueous solution and nickel sulfate ($NiSO_4$) aqueous solutions were also used for comparison. We checked several parameters which could be key factors contributing to the changes, such as the oxidation number of Cu, chemical impurities of ceria nanoparticles, and so on. Oxidation number was checked by salt formation by chemical reaction between $CuSO_4$ solution and sodium hydroxide (NaOH) solution. We observed that the color changed when $H_2SO_4$ was added to the $CuSO_4$ solution. The same effect was obtained when $H_2SO_4$ was mixed with ceria solution; the color of ceria solution changed from white to yellow. However, the color of $NiSO_4$ solution did not show any significant changes. We did observe slight changes in the pH of the solutions in this study. We did not obtain firm evidence to explain the changes observed in this study, but changes in the color of the electrolyte might be caused by interaction of Cu ion and the by-product of ceria. The mechanical properties of the films were examined by nanoindentation, and reaction between ceria and electrolyte presumably affect the mechanical properties of electrodeposited copper films. We also examined their crystal structures and optical properties by X-ray diffraction (XRD) and UV-Vis spectroscopy.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.7
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• pp.1014-1019
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• 2012

This study was conducted to evaluate the heavy metal contents of mudflat solar salt, salt water, and sea water produced in the nationwide salt pan. In mudflat solar salt, moisture contents were significantly different (p<0.001) between regions, ranging from 7.357% to 14.862%. Arsenic (As) content ranged from 0.007 ppm to 0.497 ppm, cadmium (Cd) from 0.000 ppm to 0.101 ppm, plumbum (Pb) from 0.000 ppm to 0.191 ppm, hydrargyrum (Hg) from 0.006 ppb to 0.180 ppb, and copper (Cu) from 0.039 ppm to 4.794 ppm between regions, which were significantly different (p<0.001). Further, As, Cd, Pb, and Hg contents of sea and salt water were not in excess of their criterion points. Our results suggest that heavy metal contents of mudflat solar salt, salt water, and sea water produced in the nationwide salt pan were at safe levels. However, continuous management of heavy metal contamination, such as PVC met, is still necessary.

• Journal of Environmental Health Sciences
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• v.14 no.1
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• pp.73-86
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• 1988

In order to determine the content levels of trace metals in common salts, 64 bay salt samples were collected from three producing districts and 33 bay salt samples, 32 remade salt samples and 5 fine salt samples were collected from 7 major cities in Korea, from August to September 1987. These were analysed for content levels of Pb, Cd, Cu, Zn and Mn using Atomic Absorption Spectrophotometer. The results were as follows: 1. Lead contents in three type salts were N.D. - 1081.9 $\mu$g/kg and fourteen percent of the 114 samples exceeded the World Health Organization(WHO) criteria of 100$\mu$g/kg. Cadmium contents of samples were N.D.- 382C.5 $\mu$g/kg and five percent of the 114 samples were over the Spanish criteria of 500 $\mu$g/kg. Copper contents of samples were 8,9-214.9 $\mu$g/kg and there was not a sample over the World Health Organization(WHO) criteria of 500 $\mu$g/kg. Zinc contents ranged N.D. - 342.9 $\mu$g/kg and Manganese contents ranged N.D.- 8.31 mg/kg. 2. The comparison of heavy metal contents among the bay salts from three producing districts was significantly different in Pb, Cd and Cu contents. 3. The comparison of heavy metal contents between the bay salts and remade salts was not significantly different in Pb, Cd and Cu contents. 4. The contents of Pb, Cd, Zn and Mn in fine salts were much lower than those of bay salts and remade salts.

• Journal of the Korean institute of surface engineering
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• v.36 no.4
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• pp.307-316
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• 2003

Salt spray, CASS(copper accelerated acetic salt spray) and EC(electrolytic corrosion) tests were performed in order to evaluate the corrosion resistance of plated Ni and Ni-Cr layers on Fe substrate. Compared with the conventional methods such as salt spray and CASS, the electrochemical method such as EC test may be beneficial in terms of test time span and quantitative accuracy. Furthermore, EC test can also become the alternative method to evaluate the resistance to corrosion of coatings by measuring the corrosion potentials of the coated layers in the electrolyte during the off-time of EC cycles. Compared with the corrosion potentials of pure iron, nickel, chromium, those potentials of coated layers can be used to anticipate the extent of corrosion. Results showed that in terms of the test time span, EC test gave 14 times and 21 times faster results than the salt spray test in cases of $5\mu\textrm{m}$ Ni and $20\mu\textrm{m}$ Ni plated layers, respectively. In addition, EC test also offered the shorter test time span than CASS test in cases of $5 \mu\textrm{m}$ Ni + $0.5\mu\textrm{m}$ Cr, and $20\mu\textrm{m}$ Ni + $0.5\mu\textrm{m}$ Cr on Fe substrate by 78 times and 182 times, respectively. Therefore, EC test can be regarded as the better method to evaluate the resistance to corrosion of coated layers than the conventional methods such as salt spray and CASS.

• Journal of the Korean Society of Clothing and Textiles
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• v.21 no.5
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• pp.911-921
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• 1997

Recently the interest in natural dyeing has been increased because of the color clarity, natural grace and reactionism in fashion. Indigo dyeing, safflower dyeing and Gal-ott in Cheju-Do become generally known, so the study about the natural dyeing is continued with national intrust and support. In this study, 1 used artemisia for various dyeing tests because we can get it easily. 1 tested the dyeability in wool as well as cotton and silk with wormwood in natural dyeing material. I also dyed nylon with the same material for the comparison of the molecular structure. The mercerization and the chitosan treatment were done in cotton to improve the low dyeability in the natural dyeing. The result of this study are as follows; We have to dye repeatedly to get deep color in natural dyeing, and mordant treatment brought good result in color difference and dyeing fastness. 1. Compared with silk, wool and nylon, the dyeability of cotton was the worse. The color difference of cotton was 18.81 without mordants , and 24.05 with mordant. The dyeability of cotton was much increased by mordants such as potassiumdichromate, copper sulfate, iron sulfate and salt water. The color of cotton was turned into yellow-green in potassium dichromate and yellow-green with deep green in copper sulfate. The mercerization and the chitosan treatment of cotton made the improvement in color, dyeability, laundering fastness, abrasion fastness. 2. The color difference of silk was 3 times as high as cotton. It showed the similar degree with the chitosan treated-cotton. That is to say, silk had good dyeability because it contains amino group and carboxyl group. The dyebility of silk was increased by a mordant such as iron sulfate, potassium dichromate and salt water, Drycleaning fastness showed 5 grade, abrasion-fastness was high over 4~5 grade and sunlight fastness showed 1 grade in all case. 3. The color difference of wool was the best among four fabrics because of 18 kinds of amino acids. It is considered that the sulfate of wool has the polarity and help metal- mordants get the better dyeability such as potassium dichromate, iron sulfate, copper sulfate, and aluminum chloride. The color was reddish-green in potassium dichromate, yellow.greenin iron sulfate and copper sulfate, and yellow in the rest mordants. Drycleaning fastness of wool showed over 4~5 grade, abrasion fastness 5 grade. Sunlight-fastness 1 grade. 4. The dyeability of nylon was almost same because of the similar molecular structure with silk. The clarity of color was poor. The color was yellow-green in copper sulfate and yellow in the rest mordants. Laundering fastness and abrasion-fastness of nylon was good. Sunlight- fastness represented 1 grade.

• Bulletin of the Korean Chemical Society
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• v.17 no.9
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• pp.845-849
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• 1996

Bis(N,N-dimethyl-2-aminomethylthiophenium)tetrahalocuprate(Ⅱ) salt, (dmamtH)2CuCl4 and (dmamtH)2CuBr4 were prepared and characterized by spectroscopic (IR, UV-Vis, EPR, XPS), electrochemical method, and magnetic susceptibility measurement. The experimental results reveal that the compounds have pseudotetrahedral symmetry around copper(Ⅱ) site due to the steric hinderance of the bulky 2-(dimethylaminomethyl)thiophene in the complex. The N-H…Cl type hydrogen bonding is expected in (dmamtH)2CuCl4 from the XPS and IR data. Magnetic susceptibility data show that both of the compounds follow Curie-Weiss law in the range of 77-300 K with negative Weiss constant exhibiting antiferromagnetic interaction between copper(Ⅱ) ions in solid state.

• Bulletin of the Korean Chemical Society
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• v.35 no.9
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• pp.2645-2648
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• 2014

In this paper ultrafine copper nanoparticles (CuNPs) were prepared from copper salt via chemical reduction method with sodium citrate dispersant and polyvinylalcol (PVA) capping polymer. The colloidal CuNPs were characterized by using UV-Visible spectroscopy, Transmission Electron Microscopy (TEM), and X-ray Diffraction (XRD) techniques. Our obtained results indicated that the CuNPs were produced ranging from 2 to 4 nm in diameter. The colloidal solution at 7 ppm of CuNPs exhibited a powerful antifungal activity against Corticium salmonicolor (C. Salmonicolor). Fungal killing assays showed colloid solutions containing 10 ppm of CuNPs killed entirely the cultured fungus. A highly killing activity against the fungus was also performed when the CuNPs were sprayed on pink disease-infected rubber trees. These positive results may offer a great potential to produce CuNPs-based eco-fungicide for pink disease.