• Journal of Microbiology and Biotechnology
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• v.28 no.7
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• pp.1156-1167
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• 2018

The aim of this study was to isolate and characterize lead (Pb)-solubilizing bacteria from heavy metal-contaminated mine soils and to evaluate their inoculation effects on the growth and Pb absorption of Brassica juncea. The isolates were also evaluated for their plant growth-promoting characteristics as well as heavy metal and salt tolerance. A total of 171 Pb-tolerant isolates were identified, of which only 15 bacterial strains were able to produce clear haloes in solid medium containing PbO or $PbCO_3$, indicating Pb solubilization. All of these 15 strains were also able to dissolve the Pb minerals in a liquid medium, which was accompanied by significant decreases in pH values of the medium. Based on 16S rRNA gene sequence analysis, the Pb-solubilizing strains belonged to genera Bacillus, Paenibacillus, Brevibacterium, and Staphylococcus. A majority of the Pb-solubilizing strains were able to produce indole acetic acid and siderophores to different extents. Two of the Pb-solubilizing isolates were able to solubilize inorganic phosphate as well. Some of the strains displayed tolerance to different heavy metals and to salt stress and were able to grow in a wide pH range. Inoculation with two selected Pb-solubilizing and plant growth-promoting strains, (i.e., Brevibacterium frigoritolerans YSP40 and Bacillus paralicheniformis YSP151) and their consortium enhanced the growth and Pb uptake of B. juncea plants grown in a metal-contaminated soil. The bacterial strains isolated in this study are promising candidates to develop novel microbe-assisted phytoremediation strategies for metal-contaminated soils.

• Journal of the Korean Ceramic Society
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• v.29 no.9
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• pp.711-718
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• 1992

Pb(Fe1/2Nb1/2)O3 was prepared by the molten salt synthesis method using an equimolar mixture of NaCl-KCl. Initial particle size could be controlled by varying the weight ratio of the NaCl-KCl to raw materials from 0.1 to 1.0, and the initial particle size effects on the sintering and dielectric properties of Pb(Fe1/2Nb1/2)O3 were investigated at the sintering temperature range from 90$0^{\circ}C$ to 105$0^{\circ}C$. As the weight ratio of salt increased, the average particle size decreased and the particle size distributions tended to narrow. As the initial particle size decreased, the linear shrinkage and density increased due to the promotion of densification. Dielectric constant increased with decreasing the initial particle size resulting from the increase of density and grain size.

• Journal of Environmental Science International
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• v.9 no.5
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• pp.437-441
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• 2000

A study on the removal of Pb ion from Pb-contaminated soil was carried out using ex-site extraction process. Tartaric acid (TA) and iminodiacetic acid sodium salt(IDA) as a washing agent were evaluated as a function of concentration reaction time mixing ratio of washing agent and recycling of washing agent. TA showed a better extraction performance than IDA. The optimum washing condition of TA and IDA were in the ratio of 1:15 and 1:20 between soil and acid solution during 1 hr reaction. The total concentrations of Pb ion by TA and IDA at three repeated extraction were 368.8 ppm and 267.5 ppm respectively. The recovery of Pb ion from washing solution was achieved by adding calcium hydroxide and sodium sulfide form the precipitation of lead hydroxide and lead sulfide and optimum amounts of sodium sulfide and calcium hydroxide were 7 g/$\ell$ for the TA washing solution and 4 g/$\ell$, 5g/$\ell$ for the IDA washing solution respectively. The efficiency of recycle for TA and IDA washing solution were 78.8% , 95.1%, and 89.2%, 96.6% at third extractions under $Na_2S$ and $Ca(OH)_2$, respectively.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.7 no.3
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• pp.400-405
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• 1997

Lead scandium niobate powders were prepared by a molten salt synthesis method using KCl as a flux. Variations in phase formation and particle morphology were investigated for the temperature range $700^{\circ}C$ to $850^{\circ}C$. Pure $Pb(Sc_{1/2}Nb_{1/2})O_3$ perovskite phase was formed at $850^{\circ}C$ after 2hrs and the average particle size of powder was below 0.5 $\mu\textrm{m}$. The results are discussed with respect to DTA, X-ray diffraction, and microstructural characterization data.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.3
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• pp.413-418
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• 1998

There are several types of salts that classifed into raw salts(Chunil salt, Saeng salt), purified salts (NaCl reagent grade, Hanju salt) and processed salts(Gueun salt, Saeng kum, Bamboo salt) in Korea. Their major element is NaCl but raw salt from sea water contains other minerals such as K, Mg and S. Mineral contents of the various kinds of salt analyzed with ICP-AES and AAS were different, especially on the contents of K, Mg and Ca. Chunil salt was abundant in Ca(1,037ppm), K(3,707ppm), Mg(10,266ppm) and S(7,459ppm), and salt water from the Chunil salt contained small amounts of Pb, Al, Cr and Hg. Processed salts contained high levels of Ca, K, Mg and Fe. Especially, high levels of K, P, Fe and Ge were detected in bamboo salt. Purified salts showed regular crystal form and raw salts exhibited irregular crystal form under the SEM. The processed salts were not crystal form, but fused and irregular round form.

• Journal of the Korean Ceramic Society
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• v.25 no.4
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• pp.349-356
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• 1988

The PTCR characteristics of (Ba0.8Pb0.2)TiO3 ceramics prepared by the molten salt sysnthesis (MSS) method have been investigated as a function of the amount of Nb2O5 dopant and KCl flux. When the weight ratio of KCl to raw material is 0.8, the resistivity at room temperature decreases with increasing amount of Nb dopant up to 0.6 atom%. It can be explained by compensation for electrons due to Nb+5 ion and holes due to K+ ion. The resistivity of (Ba0.8Pb0.2)(Ti0.994Nb0.006)O3 ceramics at room temperature decreases with increasing the ratio of KCl to raw material up to 0.6, and then increases. These results can be explained by the effect of K+ ion.

• Journal of the Korean Ceramic Society
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• v.28 no.1
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• pp.79-85
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• 1991

The effects of MnO2 on the microstructure and dielectric properties of Pb(Fe1/2Nb1/2)O3 ceramics prepared by KCl-NaCl molten salt synthesis(MSS) method have been investigated. As the amount of MnO2 increased up to 0.25wt%, the density increased and the grain size decreased, while above 0.25wt%, the density decreased with the grain growth. Dielectric constant increased with increasing the amount of MnO2, and dielectric loss decreased up to 0.25wt% and then increased. This is due to the compensation effect by the substitution of Mn4+ to Fe3+ and the appearance of the second phase.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.8
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• pp.1248-1256
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• 2014

The purpose of this study was to investigate the mechanisms of behind $SO_2$ formation and elevated cause of reducing power in purple bamboo salt (PBS) along with an analysis of physicochemical properties, content of sulfur compounds, oxidation reduction potential (ORP), mineral contents of salt type (MSS, mudflat solar salt; BS, bamboo salt), and addition of raw bamboo (RB). $SO_2$ content of 630 ppm was detected in PBS. $SO_2$ was not detected in MSS, BS, or RB, whereas $SO_2$ (782 ppm) from $K_2SO_4$ was detected after heating a NaCl, KCl, $MgCl_2$, $MgSO_4$, MgO, $CaCl_2$, $K_2SO_4$, and $FeSO_4$ with RB. $SO_2$ content of BS increased with baking time, and it originated from BSRB1 (13.88 ppm) to BSRB4 (109.13 ppm). $SO_3{^{2-}}$ originated only from MSSRB4 and BSRB2~BSRB4. Sulfate ion content decreased along with increasing $SO_2$ and sulfite ion contents. ORP increased with baking time of MSS and BS, and it was present at higher levels in BSRB4 (-211.40 mV) of BS than MSS. Insoluble content was higher in BS than MSS. Further, Ca, K, and Mg ion contents decreased in MSS and increased in BS with baking time. BSRB4 had 1.4 fold higher levels of Ca, 1.5 fold higher levels of Mg, and 1.8 fold higher levels of K than BS. Li, Al, Mn, Fe, and Sr in MSS as well as Al, Fe, and Ni in BS increased with baking time. Anions (Cl, $NO_3$, and Br) and heavy metals (Pb, Cd, Hg, and As) between MSS and BS were not significantly different. These results suggest that the reducing power of BS was due to $SO_2$ and sulfite ion. To increase the amounts of these compounds and reducing power, higher melting temperature and longer baking time are necessary along with BS, which is created by the addition of RB to roasted salt.

• Korean Journal of Food Science and Technology
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• v.42 no.2
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• pp.160-164
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• 2010

This study examined the safety of various salts (domestic purified salt, domestic solar salt, imported purified salt, imported solar salt) as well as the effects on the quality of kimchi fermented during 28 days at $4^{\circ}C$. All salts contained DEHP, but ferrocyanide ion and heavy metals (Cd, Pb, As, Hg) were not detected. Following fermentation, the pH of kimchi was decreased during storage, but total acidity and salinity values increased. There was no considerable differences between the various salts. As the fermentation period increased, the lactic acid bacterial counts increased remarkably. Regarding the sensory characteristics of kimchi during storage, the appearance of domestic purified salt was better than that of domestic solar salt following fermentation. Imported salts produced a strong salty taste initially, but domestic refined salt had the highest salty taste at 7 days. Therefore, there were no considerable differences between the various salts.

• Clean Technology
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• v.11 no.3
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• pp.153-164
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• 2005

This study found a reliable evaluation for four kinds of pb-Free plating solutions and it's layers, through pure Sn, SnAg, SnBi and SnCu. These four kind of solutions are widely used to pb-Free plating. Hull-cell, Harring-blum, coverage, throwing power, current efficiency, stability, life-time, composition, hardness, roughness, abrasion, scratch, solderability, corrosion, contact angle, morphology, SIR(Surface insulation resistance) and Whisker test were experimented. Also, Using ICP, XRF, FE-SEM, EDS, temperature/humidity chamber, solderability tester, hardness tester, roughness tester, abrasion tester, salt spray tester, contact angle tester, SIR tester, and microscope. In this paper could be shown the systematic and various analysis for reliability about four kinds of pb-Free plating solutions, processes and it's deposit surface.