• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.46-52
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• 2007

As flue gas desulfurization (FGD) wastewater contains high concentrations of nitrate and is very low in organic carbon, the feasibility of nitrate removal by autotrophic denitrification using Thiobacillus denitrificans was studied. This autotrophic bacteria oxidizes elemental sulfur to sulfate while reducing nitrate to elemental nitrogen gas, thereby eliminating the need for addition of organic compounds such as methanol. Owing to the unusually high concentrations of dissolved salts $(Ca^{2+},\;Mg^{2+},\;Na^+,\;K^+,\;B^+,\;SO_4^{2-},\;Cl^-,\;F^-,)$ in the FGD wastewater, extensive laboratory-scale and pilot-scale tests were carried out in sulfur-limestone reactors (1) to determine the effect of salinity on autotrophic denitrification, (2) to evaluate the use of limestone for pH control and as source of inorganic carbon for microbial growth, and, (3) to find the optimum environmental and operational conditions for autotrophic denitrification of FGD wastewater. The experimental results demonstrated that (1) autotrophic denitrification is not inhibited up to 1.8 mol total dissolved salt content; (2) inorganic carbon and inorganic phosphorus must be present in sufficiently high concentrations; (3) limestone can supply effective buffering capacity and inorganic carbon; (4) the high calcium concentration may interfere with pH control, phosphorus solubility and limestone dissolution, hence requiring pretreatment of the FGD wastewater; and, 5) under optimum conditions, complete autotrophic denitrification of FGD wastewater was obtained in a sulfur-limestone packed bed reactor with a sulfur:limestone volume ratio of 2:1 for volumetric loading rates up to 400g $NO_{3^-}N/m^3.d$. The interesting interactions between autotrophic denitrification, pH, alkalinity, and the unusually high calcium and boron content of the FGD wastewater are highlighted. The engineering significance of the results is discussed.

• Molecules and Cells
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• v.26 no.3
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• pp.236-242
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• 2008

Invertase (${\beta}$-D-fructofuranosidase; EC 3.2.1.26) catalyzes the conversion of sucrose into glucose and fructose and is involved in an array of important processes, including phloem unloading, carbon partitioning, the response to pathogens, and the control of cell differentiation and development. Its importance may have caused the invertases to evolve into a multigene family whose members are regulated by a variety of different mechanisms, such as pH, sucrose levels, and inhibitor proteins. Although putative invertase inhibitors in the Arabidopsis genome are easy to locate, few studies have been conducted to elucidate their individual functions in vivo in plant growth and development because of their high redundancy. In this study we assessed the functional role of the putative invertase inhibitors in Arabidopsis by generating transgenic plants harboring a putative invertase inhibitor gene under the control of the CaMV35S promoter. A transgenic plant that expressed high levels of the putative invertase inhibitor transcript when grown under normal conditions was chosen for the current study. To our surprise, the stability of the invertase inhibitor transcripts was shown to be down-regulated by the phytohormone ABA (abscisic acid). It is well established that ABA enhances invertase activity in vivo but the underlying mechanisms are still poorly understood. Our results thus suggest that one way ABA regulates invertase activity is by down-regulating its inhibitor.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.28 no.5
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• pp.257-264
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• 2016

In this study, experiments for measurements of entrainment rate of fluid mud were carried out using annular flume domestically for the first time. Six entrainment tests using kaolinite sediments were conducted with different initial concentrations of fluid mud. It is shown that sediment settling counteracts the otherwise buoyancy dependent entrainment of fluid mud, and that the settling effect leads to a measurably decreased entrainment rate at higher Richardson numbers in comparison with entrainment of salt water, due to additional dissipation of turbulent kinetic energy in the interfacial layer. Through the comparison with previous other studies, the overall performance of the annular flume, the experimental procedure and the test results in simulating the entrainment of fluid mud are shown to be good enough to verify.

• Applied Chemistry for Engineering
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• v.18 no.1
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• pp.36-40
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• 2007

The study on the isomerization reaction of endo-tetrahydrodicyclopentadiene and endo-tetrahydrodi(methylcyclopentadiene) using heteropolyacid catalyst was carried out. Exo compound was prepared from endo compound through isomerization reaction. To improve the problem of aluminum chloride as an isomerization catalyst, application of heteropolyacid was attempted. In use of Keggin type heteropolyacid, catalytic activity was extremely high at cesium substitution instead of 2.5 hydrogen atoms of $H_3PW_{12}O_{40}$. Using the cesium substituted heteropolyacid, isomerization reaction rate was faster than aluminum chloride and the effect of reaction temperature and times on reactivities were compared in isomerization of tetrahydrodicyclopentadiene and tetrahydrodi(methylcyclopentadiene).

• Journal of Surface Science and Engineering
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• v.49 no.5
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• pp.454-460
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• 2016

Double-layered Al-Mg films have been deposited by using an e-beam deposition method on a cold-rolled steel sheet(CR), which the structure of the film was Al/Mg/CR. The micro-structure, alloy phase, and corrosion resistance of the Al-Mg coated CR were investigated before and after heat treatment at $400^{\circ}C$ for 2, 3, and 10 min in a nitrogen atmosphere. Total thickness of Al-Mg films was fixed at $3{\mu}m$ and the thickness ratio of Al and Mg layers(Al:Mg) has been changed from 5:1 to 1:5. The cross-sectional morphology of the films, which had the thickness ratio of 2:1(Al:Mg), 1:1, and 1:2, was changed after heat treatment from columnar to featureless structure. The x-ray diffraction data for as-deposited films showed only pure Al and Mg peaks. Al-Mg alloy peaks such as $Al_3Mg_2$ and $Al_{12}Mg_{17}$ phase appeared after the heat treatment. The Al-Mg coating with the thickness ratio of 1:1(Al:Mg) showed the best corrosion resistance of up to 500 hours by salt spray test.

• Journal of Nutrition and Health
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• v.43 no.2
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• pp.132-140
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• 2010

High sodium intake is one of the risk factors for the development of hypertension. According to 2007 Korean National Health and Nutrition Examination Survey, sodium intake of Korean was three times higher than adequate intake (1.5 g/day) recommended by Korean Dietary Reference Intakes. High sodium intake is related to high threshold and preference of salty taste. And zinc status is known to affect taste acuity. The hypothesis of this study is that zinc status is associated with salty taste acuity, preference, sodium intake and blood pressure. The subjects included in this study were 50 men and 41 women aged 20-29 y who did not smoke and not take supplements or medications regularly. Dietary intake data for 3 days were collected by 24-h recall for 1 day and dietary record for 2-days. Salty taste acuity and preference were determined by sensory test. Fasting serum concentration of zinc, height, weight, body composition and blood pressure data were collected. Salt taste preference in high zinc intake group ($\geq$ estimated average requirement, EAR; men-8.1 mg/day, women-7 mg/day) was higher than that in low zinc intake group (< EAR). Salty taste preference was inversely correlated with serum zinc concentration in people with low concentration of serum zinc (${\leqq}\;81\;{\mu}g/dL$)(r = -0.3520, p < 0.05). Diastolic blood pressure was higher in high sodium intake group than in low sodium intake group (p < 0.05), positively correlated with salty taste preference (r = 0.3866, p < 0.05) in subjects with daily zinc intake below the EAR. We conclude that low zinc status may be related to high salty taste preference and high blood pressure in Korean young adults.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.2
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• pp.134-140
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• 1992

Carrot(Daucus carota L.) seeds (CV Danver 126) were primed and then separated by density differences to improve both the percentage and time of radicle emergence. Seeds for priming were soaked in aerated distilled water for 2 days (water imbibed), 25% solution of polyethylene glycol(PEG) 6000 for 6 or 10 days, salt solution of 0.2M KNO$_3$＋0.1M $K_2$HPO$_4$ for 6 or 10 days, or mixed with Agro-Lig with 90% moisture content for 6 days and 70% moisture content for 6 or 10 days (SMP) at 2$0^{\circ}C$, respectively. The greatest embryo growth and the highest radicle emergence were observed from the seeds treated SMP with 90% moisture content for 6 days among the primed treatments. After the SMP treatment, the seeds were separated into density classes with a float-sink procedure using aqueous solution of Maltrin 600 with 0.02/cm$^3$ density increments. The lower density classes of the carrot seeds, the more embryo growth, the higher and the faster rates of radicle emergence were exhibited in order from 1.06 to 1.14 density classes of the carrot seeds treated SMP.

• Analytical Science and Technology
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• v.6 no.1
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• pp.121-129
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• 1993

UV/VIS spectrophotometer interfaced with HPIC(High Performance Ion Chromatography) has been applied to the determination of lanthanide elements. The separation of lanthanide elements with HPIC helped to avoid erroneous analytical results due to interferences. Individual lanthanide elements at ppm level were separated on a HPIC CS5 column using pyromellitic acid and oxalic acid. The individual lanthanide elements were detected at 520nm following post-column reaction with PAR. Sm, Eu, Gd, Y, Tb, Dy, Ho, Er, Tm, Tb, and Lu were separated by pyromellitic acid. La, Ce, Pr and Nd were separated by oxalic acid. Appropriate pH of pyromellitic acid for separation was at pH 2.99.

• The Korean Journal of Food And Nutrition
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• v.14 no.5
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• pp.441-445
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• 2001

For the developement of probiotics, three strains haying psychorophilic and salt tolerant characteristics were isolated from Kimchi. Among the isolated strains, MGl9, MG89 and MG208 were identified as Lactobacillus brevis, Enterococcus faecium and Lactobacillus plantarum, respectively. The relationship between cryoprotectant and the viability of freeze dried strains has been studied. The most effective cryoprotectant for MGl9 was found to be 10% skim milk contained 1% soluble starch haying the survival rate of 71.4%. In MG89, 10% skim milk contained 1% sucrose and 10% skim milk contained l% fructose in MG208 were showed effective cryoprotectant having the survival rate 68.9% and 64.7%. respectively These results suggest that these isolated strains can play an important role as probiotics in aquaculture.

• Proceeding of EDISON Challenge
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• 2015.03a
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• pp.14-23
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• 2015

Alzheimer's disease is one of the most common types of degenerative dementia. As a considerable cause of Alzheimer's disease, neurotoxic plaques composed of 39 to 42 residue-long amyloid beta($A{\beta}$) fibrils have been found in the patient's brain in large quantity. A previous study found that erythrosine B (ER), a red color food dye approved by FDA, inhibits the formation of amyloid beta fibril structures. Here, in an attempt to elucidate the inhibition mechanism, we performed molecular dynamics simulations to demonstrate the conformational change of $A{\beta}40$ induced by 2 ERs in atomistic detail. During the simulation, the ERs bound to the surfaces of both N-terminus and C-terminus regions of $A{\beta}40$ rapidly. The observed stacking of the ERs and the aromatic side chains near the N-terminus region suggests a possible inhibition mechanism in which disturbing the inter-chain stacking of PHEs destabilizes beta-sheet enriched in amyloid beta fibrils. The bound ERs block water molecules and thereby help stabilizing alpha helical structure at the main chain of C-terminus and interrupt the formation of the salt-bridge ASP23-LYS28 at the same time. Our findings can help better understanding of the current and upcoming treatment studies for Alzheimer's disease by suggesting inhibition mechanism of ER on the conformational transition of $A{\beta}40$ at the molecular level.