• Korean Journal of Food Science and Technology
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• v.24 no.2
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• pp.149-153
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• 1992

Antioxidative effects of crude ethanol extract of the Rhus javanica L. and its fractionates with various synergists on the oxidation of palm oil, lard and soybean oil were compared with induction period(IP) using a Rancimat test. Addition of 200 ppm of the crude extract with phosphoric acid to palm oil extended IP 2.89 times as much as that of control and ethyl acetate fractionate extended IP 4.18 times at the same condition. To lard, 600 ppm of chloroform fraction with 200 ppm of ${\delta}-Tocopherol$ extended IP 13.42 times as much as that of control. 200 ppm of each fraction with various synergists were added to palm oil and lard, and oxidative stability of the oils were monitored by measuring POV, AV, and TBA value. The POV of palm oil containing 200 ppm of ethyl acetate and chloroform fraction with 200 ppm of phosphoric acid after 27 days storage at $60^{\circ}C$ were 8.9 meq/kg and 9.4 meq/kg respectively while the POV of control was 98.3 meq/kg at the same condition. AV and TBA value were also lower than that of control. The POV value of lard containing same amount of ethyl acetate and chloroform fraction with ${\delta}-Tocopherol$ after 12 day storage at $60^{\circ}C$ were 20.0meq/kg and 10.7 meq/kg respectively while the POV of control was 161.1 meq/kg at the same condition. AV and TBA value were also lower than that of control.

• Journal of Animal Science and Technology
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• v.62 no.3
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• pp.396-408
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• 2020

This study investigated the quality properties of enhanced beef, manufactured by injecting the beef with a brine containing winter mushroom juice powder (WMJP). The enhanced beef was manufactured by injecting the eye of round with brine (15% by green weight). Four treatments consisted of control (no injection of brine) and three enhanced beef, EBS (brine containing 5 g sodium chloride per kg beef), EBW 0.2 (brine containing 5 g sodium chloride and 2 g WMJP per kg beef), and EBW 0.5 (brine containing 5 g sodium chloride and 5 g WMJP per kg beef), were tested. The effect of enhancement or WMJP on the quality properties of beef was evaluated during storage at 4℃ for 1, 5, and 10 days. Total aerobic bacteria counts between the control and the enhanced beef, and among EBS, EBW 0.2, and EBW 0.5 were not significantly different after any storage period (p > 0.05). The pH of beef was not different between the control and the enhanced beef, and among enhanced beef at 1 and 5 days of storage (p > 0.05). However, it was higher in the enhanced beef than control, and EBW 0.2 and EBW 0.5 had higher pH than EBS after 10 days of storage (p < 0.05). The enhanced beef showed a high total loss at all storage days (p < 0.05). There were no differences in total loss among enhanced beef after any storage period (p > 0.05). The enhanced beef had no consistent differences in L*, a*, and b* values with control during storage, however, EBW 0.5 showed high color stability. The hardness of the enhanced beef was significantly lower than that of the control after 10 days of storage, although the values were lower at all storage stages. EBS 0.5 had the lowest thiobarbituric acid reactive substance (TBARS) value among cooked beef of all treatments at all storage days. The enhanced beef received higher scores in all sensory properties than control, and no negative effect of WMJP was found in the sensory quality of the enhanced beef. The use of winter mushroom juice can result in quality improvement in enhanced beef.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.2
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• pp.151-157
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• 2005

A one-dimensional numerical model was developed to simulate vertical profiles of electron acceptors and their reduced species in benthic sediments. The model accounted for microbial degradation of organic matter and subsequent chemical reactions of interest using stoichiometric relationships. Depending on the dominant electron acceptors utilized by microorganisms, the benthic sediments were assumed to be vertically subdivided into six zones: (1) aerobic respiration, (2) denitrification, (3) manganese reduction, (4) iron reduction, (5) sulfate reduction, and (6) methanogenesis. The utilizations of electron acceptors in the biologically mediated oxidation of organic matter were represented by Monod-type expression. The mass balance equations formulated for the reactive transport of organic matter, electron acceptors, and their corresponding reduced species in the sediments were solved utilizing an iterative multistep numerical method. The ability of model to simulate a freshwater sediments system was tested by comparing simulation results against published data obtained from lake sediments. The simulation results reasonably agreed with field measurements for most species, except for ammonia. This result showed that the C/N ratio (106/16) in the sediments is lower than what the Redfield formula prescribes. Since accurate estimates of vertical profiles of electron acceptors and their reduced species are important to determine the mobility and bioavailability of trace metals in the sediments, the model has potential application to assess the stability of selected trace metals in the sediments.

• Korean Chemical Engineering Research
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• v.43 no.3
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• pp.425-431
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• 2005

New type of supercapacitor using high surface area activated carbons mixed with high conductivity polypyrrole (Ppy) has been prepared in order to achieve low impedance and high energy density. Mixed carbons of BP-20 and MSP-20 were used as the active electrode material, and polypyrrole doped with 2-naphthalenesulfonic acid (2-NSA) and carbon black (Super P) as conducting agents were added to activated carbons in order to enhance good electric conductivity. Electrodes prepared with the activated electrode materials and the conducting agents were added to a solution of organic binder [P(VdF-co-HFP) / NMP]. The ratio of optimum electrode composition was 78 : 17 : 5 wt.％ of (MSP20 : BP-20=1 : 1), (Super P : Ppy=10 : 7) and P(VdF-co-HFP) respectively. The performance of unit cell with addition of 7 wt％ Ppy have shown specific capacitance of 28.02 F/g, DC-ESR of $1.34{\Omega}$, AC-ESR of $0.36{\Omega}$, specific energy of 19.87 Wh/kg and specific power of 9.77 kW/kg. With addition of Ppy, quick charge-discharge of unit cell was possible because of low ESR, low charge transfer resistance and quick reaction rate. And good stability up to 500 chargedischarge cycles were retained about 80％ of their original capacity. It was concluded that the specific capacitance originated highly from compound phenomena of the pseudocapacitance by oxidation-reduction of polypyrrole and the nonfaradaic capacitance by adsorption-desorption of activated carbons.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.11
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• pp.1054-1062
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• 2010

Oxidative coupling reactions of humic substances (HS) can be catalyzed by a variety of natural extracellular enzymes and metal oxides. In this study, property changes of HS induced by a natural enzyme, horseradish peroxidase (HRP), and the effect of it to microfiltration (MF) were investigated. PAHA was transformed by oxidative coupling reaction with HRP and hydrogen peroxide ($H_2O_2$), verifying the catalytic effects of the HRP. Size exclusion chromatography (SEC) revealed that weight-average molecular weight (MWw) of PAHA was proportionally increased with the dosages of HRP and $H_2O_2$, indicating the transform action of HS into larger and complex molecules. An increase in the conformational stability of HS was achieved through the promotion of intermolecular covalent bondings between heterogeneous humic molecules. Spectroscopic analysis (fluorescence and infrared spectroscopy) proved that functional groups were transformed by the reaction. Additionally, HS and transformed products were undergone microfiltration (MF) to examine the treatment potential of them in a water treatment facility. Original HS could not be removed by MF but larger molecules of transformed products could be removed. Meanwhile, transformed products caused more fouling on the filtration than original HS. This results proved that natural organic matter (NOM) can be removed by MF after its increase in molecular size by oxidative coupling reaction.

• Korean Chemical Engineering Research
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• v.46 no.1
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• pp.194-199
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• 2008

In this study, the effective method to esterify the free fatty acids in jatropha oil was examined. Compared to other plant oils, the acid value of jatropha oil was remarkably high, 11.5 mgKOH/g. So direct transesterification by a base catalyst was not suitable for the oil. After the free fatty acids were esterified with methanol, jatropha oil was transesterified. The activities of four solid acid catalysts were tested and Amberlyst-15 showed the best activity for the esterification. After constructing the experiment matrix based on RSM and analyzing the statistical data, the optimal esterification conditions were determined to be 6.79% of methanol and 17.14% of Amberlyst-15. After the pretreatment, jatropha biodiesel was produced by the transesterification using KOH in a pressurized batch reactor. Jatropha biodiesel produced could meet the major specifications of Korean biodiesel standards; 97.35% of FAME, 8.17 h of oxidation stability, 0.125% of total glycerol and $0^{\circ}C$ of CFPP.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.4
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• pp.505-511
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• 2008

This study was carried out to investigate the antioxidative effect of Kochujang seasoning sauce with the addition of fruit and vegetable extract (FVE) for pork Bulgogi, as well as to establish the optimum mixture ratio of ingredients using mixture experimental design (MED). During 5 months of storage at $-25^{\circ}C$, the thiobarbituric acid (TBA) values of the seasoned pork containing soy sauce (control), Kochujang added group (KG) and Kochujang and FVE added group (KFVEG) were remarkably lower than that of unseasoned pork. Among the seasoned porks, the antioxidative effect of KG was much higher than the control. Moreover, TBA values of KFVEG were significantly lower than those of KG. Therefore, the lipid oxidation stability of seasoned pork Bulgogi was improved by the addition of Kochujang, red pepper powder and FVE into the seasoning sauce. When Kochujang was used in seasoning sauce, the preference scores of pork Bulgogi increased with the increasing amount of red pepper powder and FVE. The optimum mixture ratios of seasoning sauce for pork Bulgogi established by the MED were Kochujang 0.04, red pepper powder 0.20, FVE 0.39 and water 0.37.

• Korean Journal of Materials Research
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• v.21 no.1
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• pp.8-14
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• 2011

To improve the chemical stability of metal, the ceramic coatings on metallic materials have attracted interest from many researchers due to the chemical inertness of ceramic materials. To endure strong acids, SiOC coating on metal substrate was carried out by dip coating method using 20wt% polyphenylcarbosilane solution; SiC powder was added to the solution at 10wt% and 15wt% to improve the mechanical properties and to prevent cracks of the film. Thermal oxidation as a curing step was carried out at $200^{\circ}C$ for crosslinking of the polyphenylcarbosilane, and the coating samples were pyrolysized at $800^{\circ}C$ under argon to convert the polyphenylcarbosilane to SiOC film. The thicknesses of the SiOC coating films were $2.36{\mu}m$ and $3.16{\mu}m$. The quantities of each element were measured as $SiO_{1.07}C_{6.33}$ by EPMA, and it can be confirmed that the SiOC film from polyphenylcarbosilane was formed in a manner that was carbon rich. The hardness of the SiOC film was found to be 3.2Gpa through nanoindentor measurement. No defect including cracks appeared in the SiOC film. The weight loss of the SiOC coated stainless steel was within 2% after soaking in 10% HCl solution at $80^{\circ}C$ for one week. From these results, SiOC coating shows good potential for application to protect against severe chemical corrosion of stainless steel.

• Journal of the Semiconductor & Display Technology
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• v.6 no.3
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• pp.19-23
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• 2007

The NiSi is very promising candidate for the metallization in 45 nm CMOS process such as FUSI(fully silicided) gate and source/drain contact because it exhibits non-size dependent resistance, low silicon consumption and mid-gap workfunction. Ni film was first deposited by using ALD (atomic layer deposition) technique with Bis-Ni precursor and $H_2$ reactant gas at $220^{\circ}C$ with deposition rate of $1.25\;{\AA}/cycle$. The as-deposited Ni film exhibited a sheet resistance of $5\;{\Omega}/{\square}$. RTP (repaid thermal process) was then performed by varying temperature from $400^{\circ}C$ to $900^{\circ}C$ in $N_2$ ambient for the formation of NiSi. The process temperature window for the formation of low-resistance NiSi was estimated from $600^{\circ}C$ to $800^{\circ}C$ and from $700^{\circ}C$ to $800^{\circ}C$ with and without Ti capping layer. The respective sheet resistance of the films was changed to $2.5\;{\Omega}/{\square}$ and $3\;{\Omega}/{\square}$ after silicidation. This is because Ti capping layer increases reaction between Ni and Si and suppresses the oxidation and impurity incorporation into Ni film during silicidation process. The NiSi films were treated by additional thermal stress in a resistively heated furnace for test of thermal stability, showing that the film heat-treated at $800^{\circ}C$ was more stable than that at $700^{\circ}C$ due to better crystallinity.

• Food Science of Animal Resources
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• v.32 no.2
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• pp.198-203
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• 2012

To improve hygienic quality of egg, the ozone treatment was applied. Eggs were inoculated with Salmonella Typhimurium, and the inoculated eggs were treated by ozone (38.8 ppm) for 10-30 min. Furthermore, microbiological and chemical quality changes of eggs were investigated during storage. Initial number of S. Typhimurium of egg shell was 6.18 log CFU/g and the number was increased during storage (p<0.05). However, those of ozonated samples for 10-30 min were 4.22-5.25 log CFU/g, which was lower than that of the control. Especially, ozone treatment for 30 min achieved about 2 decimal reductions and the numbers were maintained during storage. Other physical and chemical characteristics of eggs by ozone treatment, including Haugh unit, yolk color, pHs of egg white and yolk, foaming ability, foam stability and lipid oxidation development were not different when compared with that of the control. Therefore, ozone treatment is one of the available methods to improve hygienic quality of eggs.