• Korean Journal of Materials Research
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• v.9 no.10
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• pp.985-991
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• 1999

Corrosion behaviors of Incoloy 800H, KSA(Kaeri Superalloy)-6, Inconel 600 and Hastelloy C-276 in molten salts were investigated in the temperature range of 650 ~ $850^{\circ}C$. Due to $\textrm{Li}_{2}\textrm{O}$-induced basic fluxing mechanism, the corrosion rates of the alloys in mixed molten salt of LiC1-$\textrm{Li}_{2}\textrm{O}$ were significantly higher than those in molten salt of LiCl. In the mixed molten salt, Fe-base alloys showed higher corrosion resistance than the Ni-base alloys. and Hastelloy C-276 with high Mo and W contents exhibited the highest corrosion rate among the examined alloys. The single layer of $\textrm{LiCrO}_{2}$ was formed in molten salt of LiCl and two phase structure of a scale consisted of oxides and Ni was formed in the mixed molten salt.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.4 no.4
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• pp.305-311
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• 1999

This study aims to decipher surface water mass interaction in summer in the South China Sea and East China Sea by radium isotope distribution pattern. Salinity and activity ratio of radium ($^{228}Ra/^{226}Ra$) showed gradual changes, which were adequate to apply simple two end-member mixing between Kuroshio surface water and Changjiang Dilute Water for the East China Sea and the former and Nearshore Diluted Watermass (NDW) for the South China Sea. Two tracer methods, salinity and Ra isotope ratio, were compared for East China Sea. Results showed remarkable consistency for waters near Kuroshio, however, discrepancy were noticeable after Tsushima Warm Current branching. Mixing with subsurface waters may cause the discrepancy. When mixed with subsurface waters, salts and radium isotope ratio are expected to be biased in opposite direction, i. e. prone to underestimate the fraction of less saline water in the case of salts and vice versa for Ra isotope ratio. Taking the mean values of two different results seems more realistic to estimate fraction of end-members.

• Applied Chemistry for Engineering
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• v.9 no.2
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• pp.273-277
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• 1998

The synthesis of hydroxy-terminated poly(propylene carbonate)(HTPPC) was performed by the reaction of propylene carbonate(PC) with alcohol initiator using metal alkoxides, crown ethers and quaternary onium salts as catalysts. The effects of catalyst structure, types and concentration of alcohol, and solvent were investigated. Among the alkoxide catalysts tested, the ones with higher Lewis acidity and with more nucleophilic alkoxide anion showed higher catalytic activity. Mixed catalysts of metal alkoxied and crown ether showed higher conversion of PC than metal alkoxide alone. Quaternary onium salts of bulky cation exhibited higher catalytic activity. High polar solvent showed higher yield of HTPPC and the yield increased with the decrease of [PC]/[Initiator] ratio.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.12
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• pp.1915-1923
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• 2013

The aim of this study is carried out to evaluate the fermentation characteristics and increased functionality when doenjang was prepared with bamboo salts. Grain type mejus were fermented with mixed starter cultures of Aspergillus oryzae, Bacillus subtilis, and Lactococcus lactis. These mejus were mixed with different kinds of salts-purified salt (PD), sea salt (SD), one-time baked bamboo salt ($1{\times}BD$), three-time baked bamboo salt ($3{\times}BD$), and nine-time baked bamboo salt ($9{\times}BD$)- when doenjangs were prepared. For doenjang fermentation period of 8 weeks at $37^{\circ}C$, the fermentation characteristics of all the groups were compared. The amino type nitrogen content and enzyme activities (protease and ${\alpha}$-amylase) in the samples were significantly increased. In DPPH radical scavenging activities and hydroxyl radical scavenging activities, $9{\times}BD$ (47% and 69%) showed the highest scavenging activities compared to PD (40% and 49%), SD (42% and 57%), $1{\times}BD$ (42% and 64%) and $3{\times}BD$ (45% and 65%) (P<0.05). The anticancer effects of doenjang in HT-29 cancer cells indicated all the groups, especially doenjang prepared with bamboo salts were higher than the others (P<0.05). Apoptosis related genes of Bax and Bcl-2, as well as inflammation related genes of iNOS and COX-2 were regulated by the treatment of doenjangs in HT-29 cancer cells. SD, $1{\times}BD$, $3{\times}BD$, and $9{\times}BD$ increased the expression level of Bax and decreased the expression level of Bcl-2, iNOS, and COX-2. These results suggest that sea salt and bamboo salt especially bamboo salt could improve fermentation characteristics and functionality of doenjang and play an important role in regulating apoptosis and inflammation related genes in cancer cells.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.5
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• pp.552-557
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• 2010

This study was performed to investigate the effect of zeolite on the reduction of soil EC level in the plastic film house. The EC level of experimental soil was 5.0 dS $m^{-1}$ and the zeolite was applied to the soil at seven levels (0.5, 1, 2, 5, 10, 15, 20%) with three replications. The reduction degree of soil EC level showed positive tendency to the mixing ratio of zeolite. Especially, the EC level reduced rapidly from 5.01 to 2.8 dS $m^{-1}$ in the plot where zeolite was mixed by 20% 10 days after treatment. The pH level of soil was in positive relation to the mixing ratio of zeolite, contrary to the negative relation to the concentration level of water soluble Ca, Mg and phosphorus (P). The water contents of soil mixed with 15% and 20% zeolite were 14% and 17.3% respectively but it was 12.7% for control soil. Therefore, we expect natural zeolite to salts reduction agent for exchangeable cation and phosphate which is difficult to reduce by watering and other methods.

• Membrane Journal
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• v.24 no.1
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• pp.69-77
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• 2014

To prepare the hollow fiber nanofiltration composite membranes, the poly(vinylidene fluoride) (PVDF) membrane was hydrophilized with $K_2Cr_2OH$ and $KMnO_4$ aqueous solutions. And then the composite membrane was synthesized on that membrane surfaces using interfacial polymerization with piperazine (PIP) and trimesoyl chloride (TMC). The resulting membranes were characterized in terms of the rejection and flux for NaCl, $CaSO_4$, $MgCl_2$ 100 ppm solution and 300 ppm of NaCl and $CaSO_4$ mixed solution by varying the coating time, drying time, and the concentration of the coating materials. As a result, the higher rejections were shown for $K_2Cr_2OH$ solutionas a hydrophilization material, and the flux was enhanced while the rejection reduced as the hydrophilization time is longer. Also, the rejection increased and the flux reduced as the concentrations of triethyl amine (TEA) and sodium lauryl sulfate (SLS) were higher. Typically, the rejection 50% and flux 40 LMH for NaCl 100 ppm solution, and the rejection 55% and flux 48 LMH for $CaSO_4$ 100 ppm solution were obtained for the PVDF hollow fiber composite membrane prepared with the conditions of PIP 2 wt% (Triethyl amine (TEA) 7 wt%, SLS 20 wt% mixed solution against PIP concentration) and TMC 0.1 wt%.

• Korean Journal of Materials Research
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• v.10 no.7
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• pp.471-477
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• 2000

Corrosion behavior of Fe-Ni-Cr alloy in molten salts of LiCl and LiCl-$Li_2O was investigated in the tempera-ture range of $650~850^{\circ}C$. In the molten salt of LiCl, and internal oxidation of Fe occurred in the KSA(Kaeri Superalloy)-1 alloy without containing Cr, while a dense protective oxide scale of $LiCrO_2$ was formed in the KSA-4, Incoloy 800H and KSA-5 alloys. In the mixed molten salt of LiCl-$Li_2O$, internal oxidation of Fe and Cr took place in the KSA-1 and KSA-4 alloys, respectively. Non-protective porous oxide scales consisting of $LiCrO_2$ and Ni were formed in the Incoloy 800H and KSA-5. The corrosion rate of the alloys increased with the increase in Cr content and the corrosion rate followed the parabolic law for the alloy containing Cr content less than 8%, and the linear law for the alloy containing Cr content more than 8%. Such a corrosion behavior of the alloy in the mixed molten salt of LiCl-$Li_2O$ was interpreted in terms of the basic fluxing mechanism of protective oxide scale of $Cr_2O_3$.

• Membrane and Water Treatment
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• v.10 no.3
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• pp.207-212
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• 2019

Non-aqueous solvents (NASs) are generally known to be barely miscible, and reactive with polar compounds, such as water. However, water can interact with some NASs, which can be used as a new means for water recovery from saline water. This study explored the fate of water and salt in NAS, when saline water is mixed with NAS. Three amine solvents were selected as NAS. They had the same molecular formula, but were differentiated by their molecular structures, as follows: 1) NAS 'A' having the hydrophilic group ($NH_2$) at the end of the straight carbon chain, 2) NAS 'B' with symmetrical structure and having the hydrophilic group (NH) at the middle of the straight carbon chain, 3) NAS 'C' having the hydrophilic group ($NH_2$) at the end of the straight carbon chain but possessing a hydrophobic ethyl branch in the middle of the structure. In batch experiments, 0.5 M NaCl water was blended with NASs, and then water and salt content in the NAS were individually measured. Water absorption efficiencies by NAS 'B' and 'C' were 3.8 and 10.7%, respectively. However, salt rejection efficiency was 98.9% and 58.2%, respectively. NAS 'A' exhibited a higher water absorption efficiency of 35.6%, despite a worse salt rejection efficiency of 24.7%. Molecular dynamic (MD) simulation showed the different interactions of water and salts with each NAS. NAS 'A' formed lattice structured clusters, with the hydrophilic group located outside, and captured a large numbers of water molecules, together with salt ions, inside the cluster pockets. NAS 'B' formed a planar-shaped cluster, where only some water molecules, but no salt ions, migrated to the NAS cluster. NAS 'C', with an ethyl group branch, formed a cluster shaped similarly to that of 'B'; however, the boundary surface of the cluster looked higher than that of 'C', due to the branch structure in solvent. The MD simulation was helpful for understanding the experimental results for water absorption and salt rejection, by demonstrating the various interactions between water molecules and the salts, with the different NAS types.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.2 no.2
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• pp.99-108
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• 1998

Results obtained from this research showed that the anaerobic contact process was applicable to pear waste with COD removal efficiencies of up to $95\%$ depending on conditions, provided ammonium and phosphate salts were added as well as other nutrients, present in the commercial fertilizer, Milorganite or in yeast extract. These latter materials were required in minimum concentrations of 5 and 1.5 g/L, respectively, in the feed independent of HRT and volatile solids loading rate, with part of the effect due to the mineral fraction. Digestion was satisfactory over the whole range of volatile solids loading rates and liquid retention time of 30 to 0.5 days tested, although treatment efficiency dropped off noticeably between 1 and 0.5 day liquid retention time because of poorer flocculation and separation of anaerobic bacteria. Settling of anaerobic bacteria including methane producing bacteria was related to settling of mixed liquor suspended solids only at 1 to 5 days liquid retention times, at other liquid retention times anaerobic microorganism settled markedly less efficiently than mixed liquor suspended solids. Further studies are being made to provide information of practical and basic interest. Data on the composition of the active fraction of yeast extract might solve many practical nutrient problems encountered with the anaerobic contact process and improve its economics. Further improvement in the flocculation and settling of anaerobic bacteria as well as other bacteria would improve overall performance and allow the use of shorter liquid retention times with dilute waste. Knowledge about the numbers of methane formers present would allow a degree of understanding and control of the process not presently attainable.

• Journal of the Korean Ceramic Society
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• v.42 no.6 s.277
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• pp.432-436
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• 2005

Nickel powders synthesized by the reduction of hydrazine of nickel salts fiom diethanolamine(DEA) solution, and investigated the morphological characteristics of nickel powders with the addition of hydrazine, reaction temperature, the composition of mixed solvents. The addition of hydrazine in DEA solution largely affected on size control of nickel powders. Under $N_2H_4/Ni^{2+}$ molar ratio= 1.5 and 2.0 conditions, spherical nickel powders in the submicron range obtained, owing to higher the reduction rate. An increase of temperature increased the size of nickel particles. At $220^{\circ}C$ for 40 min, the nickel powders composed of polyhedral particles with high crystalline in the submicron range. The mixed volume ratio of TEA to DEA affected on the increase of particle size and the inhibition of agglomerate between particles.