• Korean Journal of Food Science and Technology
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• v.31 no.4
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• pp.1029-1034
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• 1999

To enhance the cleaning and sterilization effect of cooled electrolyzed acid water on lettuce, several kinds of polysorbates were used at various concentrations in immersion washing process. In case of the treatment containing polysorbate 20, coliform count of lettuce was reduced to about 1/40 level of that in non-treated lettuce. The treatment containing polysorbate 60 did not show a significant sterilization effect. Otherwise, the total and coliform counts of lettuce during immersion in electrolyzed acid water containing 1 ppm of polysorbate 80 was reduced to about 1/300 and 1/1,700 level of those in non-treated one. And, the changes of ORP(oxidation-reduction potential), pH and color value of lettuce in electrolyzed acid water containing 1 ppm of polysorbate 80 were not quite different during 60 min. immersion, but HCIO content decreased from 10.28 ppm to 8.51 ppm after 20 min. immersion. Also, total and coliform count of lettuce immersed in electrolyzed acid water containing 1 ppm of polysorbate 80 was lower to about 1/1,800 after 20 min. and 1/5,550 after 30 min, compared with non-treated lettuce.

• Clean Technology
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• v.23 no.3
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• pp.308-313
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• 2017

In this study, we investigated the electrocatalytic effects of the N and O co-doping of Graphite Felt (GF) electrode for the vanadium redox flow battery (VRFB) at the cathode and the anode reaction, respectively. The electrodes were prepared by chemical vapor deposition (CVD) with $NH_3-O_2$ at 773 K, and its effects were compared with an electrode prepared by an O doping treatment. The surface morphology and chemical composition of the electrodes were characterized by scanning electron microscopy (SEM) and photoelectron spectroscopy (XPS). The electrocatalytic properties of these electrodes were characterized in a VRFB single cell comparing the efficiencies and performance of the electrodes at the cathode, anode, and single cell level. The results exhibited about 2% higher voltage and energy efficiencies on the N-O-GF than the O-GF electrode. It was found that the N and O co-doping was particularly effective in the enhancement of the reduction-oxidation reaction at the anode.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.4
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• pp.437-443
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• 1995

Concerns on use of excess amount of chemical fertilizier and pesticide in current farming system turns both of the producer and consumer of agricultural products to an organic farming which use a less chemicals and more natural manure. Rice-duck farming system is one of the strategy to meet the purpose and this experiment was carried out to find the effect of the rice-duck farming system on the quality and yields of rice. 20day-old rice seedling were mechanically transplanted in sandy-loam paddy field and 21 day-old ducks were raised from 3 weeks after transplanting with population of 30 heads per 10a. The plots were consists of reduce fertilizer(70%) with and without duck-raising. The conventional fertilizer treatment without duck-raising was used as check. The results obtained are summarized as follows. The weeds population of test plots which were raised with duck for 3 consecutive years was less than that of test plots without duck-raising, though a speciffic population of Echinochola crusgallis were increased. The weed control effect was higer in duck-raising than in check at the maximum tillering stage but, not at later stages of rice plant. It was found that the small animals and insects inhibiting in the rice field were reduced by duck-treatment, however, there were also damages of grass leaf roller at booting stage in the plots of duck-raising. In rice-duck plot, dark green leaf color were found: 41.8 of SPAD value than 38.6 of SPAD in check plot. Higher root activity and surface soil oxidation were also observed in rice-duck plot than check plot. 3% of the increase in yield was observed by duck-treatment. However, the expected increase of the palatability wsa not observed. This may be due to the unfavorable weather conditions during the rice growing in this expriment.

• Korean Journal of Weed Science
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• v.32 no.2
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• pp.115-120
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• 2012

Weed control is of fundamental importance when planting cereal crops, particularly during the establishment phase. Weeds compete for nutrients, water and light, and can severely threaten the survival and early growth of newly planted crops. Field experiment was conducted to evaluate the effect of ethanol treatment on the weed control efficacy in cereal crops in protected vinylhouse. Five treatments like water, 25 L, 50 L, 75 L, and 100 L per $m^{-2}$ at 2% ethanol were applied and covered with vinyl on 10 days before foxtail millet seeding. After that, foxtail millet seeds were sown on June 20 at $60{\times}10cm$ planting distance and weed control efficacy was recorded at 30, and 50 days after seeding based on the dry weight. Soil oxidation-reduction potential was recorded -200~-400 mV after treatment 2 days. Weed control efficacy of at 75 L, and 100 L per $m^{-2}$ was observed 92%, 84% in 2% ETOH, respectively. Yields of foxtail millet at 75 L, and 100 L per $m^{-2}$ were 1,570 kg $ha^{-1}$, 1,230 kg $ha^{-1}$, respectively.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.27 no.6
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• pp.309-312
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• 2017

The ceria powder is excellent in oxygen storage capacity (OSC) through the oxidation and reduction reaction of Ce ions and is used as a typical material for a three-way catalyst of an automobile which purifies the exhaust gas. However, since ceria generally has poor thermal stability at high temperatures, it is doped with metal ions to improve thermal stability. Therefore, in this study, Zr ions were doped into ceria powder, and their characteristics were further improved due to the increase of specific surface area with decreasing particle size due to doping. In this study, the synthesis of zirconium doped ceria nanopowder was synthesized by hydrothermal process. In order to synthesis Zr ion doped ceria nanopowder, the precursor reaction at was $200^{\circ}C$ for 6 hours. The average particle size of synthesized Zr doped $CeO_2$ nanopowder was below 20 nm. The specific surface area of synthesized Zr ion doped ceria nanopowder increased from $52.03m^2/g$ to $132.27m^2/g$ with Zr increased 30 %.

• Journal of Mushroom
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• v.2 no.3
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• pp.127-139
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• 2004

Laccases are multicopper-containing enzymes which catalyze the oxidation of phenolic and nonphenolic compounds with the concomitant reduction of molecular oxygen. They often occur as isoenzymes, either constitutive or inducible, that oligomerize to multilateral complexes, what allow for penetration to the woody cell wall structure. White rot basidiomycete fungi may produce a number of laccase isoenzymes, some constitutively and others after induction. Fungal laccase is commonly induced by many ions, such as $Cu^{2+}$, $Cd^{2+}$ $Ca^{2+}$, $Li^+$, $Mn^{2+}$, $Ag^+$, $Hg^{2+}$, Mn and $Fe^{3+}$, phenolic compounds, some organic compounds, such as ethanol, isopropanol, cAMP, caffeine, p-anisidine, viscosinamide and paraquat, and nitrogens and even heat shock. A combination of Cu and pHB (p-hydroxybenzoic acid) made it possible to extend the inducible laccase activities over 30-fold. But the most effective inducer of laccase in the basidiomycete and other higher fungi is 2,5-xylidine, over 160-fold stimulation of laccase activity. The laccases are frequently encoded by gene families, as e.g. in Pycnoporus cinnabarinus, from which the lcc3-1 or the allelic form lac1 and lac3-2 have been cloned and sequenced. In the case of inducible forms the post-inductional laccase formation depends upon the synthesis of mRNA and the induction is due to the synthesis of a new protein.

• Journal of the Korean Applied Science and Technology
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• v.32 no.1
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• pp.78-84
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• 2015

The purpose of this study is to evaluate the removal efficiency of phosphorus from synthetic waste water by reduction and oxidation reaction of Cu-Zn metal alloy. Cu-Zn metal alloy applied in this study is composed of 40% of Zn and 60% of Cu, which is so called Muntz metal. And the fibrous type of metal alloy has approximately $200{\mu}m$ of thickness. Metal is oxidized in an aqueous solution to generate electron and metal ion. The mechanism of phosphate treatment is co-precipitation of metal ion and phosphorous ion at various pH and temperature. The treatment efficiency showed the maximum at a one cycle treatment. This result means that the surface area of reaction material is sufficient enough to get reaction equilibrium. Experiment is conducted at various pH from 5 to 9, and showed the maximum efficiency at pH 8. Phosphorous is dominated as a type of $H_2PO_4{^-}$ and $HPO_4{^{2-}}$ at this pH condition. We could not consider the temperature effect independently, because phosphorous removal efficiency showed such a complex mechanism. We could get high efficiency at lower temperature in this research.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.12
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• pp.1813-1818
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• 2015

Grape seed extract (GSE) was added to grape seed oil to improve the oxidative stability of the grape seed oil during storage. To measure the oxidative stability of grape seed oil, peroxide value, acid value, and conjugated diene value were measured, and changes in browning, vitamin E, fatty acid composition, and polyphenol content of oil were examined. In the case of grape seed oil with GSE, peroxide value, acid value, and conjugated diene value were lower than those of grape seed oil. The magnitude of increase in absorbance of grape seed oil with GSE was less than that of additive-free grape seed oil, whereas the magnitude of decrease in vitamin E isomers in grape seed oil with GSE was less than that of grape seed oil with no additive. Changes in fatty acid composition were also similar. However, polyphenol contents showed the greatest reduction in grape seed oil containing GSE. GSE contributes to the oxidation stability of grape seed oil, but the antioxidant capacity of GSE was lower than that of butylated hydroxytoluene.

• Korean Journal of Materials Research
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• v.25 no.12
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• pp.719-726
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• 2015

For a decade, solution-processed functional materials and various printing technologies have attracted increasingly the significant interest in realizing low-cost flexible electronics. In this study, Cu nanoparticles are synthesized via the chemical reduction of Cu ions under inert atmosphere. To prevent interparticle agglomeration and surface oxidation, oleic acid is incorporated as a surface capping molecule and hydrazine is used as a reducing agent. To endow water-compatibility, the surface of synthesized Cu nanoparticles is modified by a mixture of carboxyl-terminated anionic polyelectrolyte and polyoxylethylene oleylamine ether. For reducing the surface tension and the evaporation rate of aqueous Cu nanoparticle inks, the solvent composition of Cu nanoparticle ink is designed as DI water:2-methoxy ethanol:glycerol:ethylene glycol = 50:20:5:25 wt%. The effects of poly(styrene-co-maleic acid) as an adhesion promoter(AP) on rheology of aqueous Cu nanoparticle inks and adhesion of Cu pattern printed on polyimid films are investigated. The 40 wt% aqueous Cu nanoparticle inks with 0.5 wt% of Poly(styrene-co-maleic acid) show the "Newtonian flow" and has a low viscosity under $10mPa{\cdots}S$, which is applicable to inkjet printing. The Cu patterns with a linewidth of $50{\sim}60{\mu}m$ are successfully fabricated. With the addition of Poly(styrene-co-maleic acid), the adhesion of printed Cu patterns on polyimid films is superior to those of patterns prepared from Poly(styrene-co-maleic acid)-free inks. The resistivities of Cu films are measured to be $10{\sim}15{\mu}{\Omega}{\cdot}cm$ at annealing temperature of $300^{\circ}C$.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.6 no.1
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• pp.78-82
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• 2005

Display manufacturing process has adopted RCA cleaning, applying to larger area and coping with environmental issue for last ten years. However, the approaching concept of ozonized, hydrogenised, or electrolyzed water cleaning technologies is within RCA clean paradigm. In this work, only electrolyzed anode water was applied to clean particles and organics as well as metals based on Pourbaix concept, and as a test vehicle, MgO particles were introduced to prove the new concept. The electrolyzed anode water is very oxidative with high oxidation reduction potential (ORP) and low in pH of more than 900 mV and 3.1, respectively. MgO particles were immersed in the anode water and its weight losses due to dissolution were measured with time. Weight losses were in the ranges of 100 to 500 micrograms in 250 ml anode water depending on their ORP and pH. Therefore it was concluded that the cleaning radicals in the anode water was at least in the range of 1 to $5{\times}10^{20}$ ea per 250 ml anode water equivalent to $1{\times}10^{18} ea/cm^2$. Hence it can be assumed that the anode water applied to display cleaning from now on $1{\times}10^{10}$ to $1{\times}10^{15} ea/cm^2$ ranges of contaminants are being treated. In addition, it was observed that anode water did not develop micro-roughness on hydrophobic surface while it did on the native silicon oxide.