• Clean Technology
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• v.22 no.1
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• pp.16-28
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• 2016

Textile industry is considered as one of the most polluting sectors in terms of effluent composition and volume of discharge. It is well known that the effluents from textile dying industry contain not only chromatic substances but also large amounts of organic compounds and insolubles. The azo dyes generate huge amount of pollutions among many types of pigments. In general, the electrochemical treatments, separating colors and organic materials by oxidation and reduction on electrode surfaces, are regarded as simpler and faster processes for removal of pollutants compared to other wastewater treatments. In this paper the electrochemical degradation characteristics of dye wastewater containing CI Direct Blue 15 were analyzed. The experiments were performed with various anode materials, such as RuO₂/Ti, PtO₂/Ti, IrO₂/Ti and graphite, with stainless steel for cathode. The optimal anode material was located by changing operating conditions like electrolyte concentration, current density, reaction temperature and initial pH. The degradation efficiency of dye wastewater increased in proportion to the electrolyte concentration and the current density for all anode materials, while the temperature effect was dependent on the kind. The performance orders of anode materials were RuO₂/Ti > PtO₂/Ti > IrO₂/Ti > graphite in acid condition and RuO₂/Ti > IrO₂/Ti > PtO₂/Ti > graphite in neutral and basic conditions. As a result, RuO₂/Ti demonstrated the best performance as an anode material for the electrochemical treatment of dye wastewater.

• Economic and Environmental Geology
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• v.41 no.6
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• pp.685-693
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• 2008

The rates of oxidative degradation of perchloroethene (PCE) and trichloroethene (TCE) using $KMnO_4$ solution were evaluated under the flow condition using a bench-scale transport experimental setup. Parameters which are considered to affect the reaction rates tested in this study were the contact time (or retention time), and the concentration of oxidizing agent. A glass column packed with coarse sand was used for simulating the aquifer condition. Contact time between reactants was controlled by changing the flow rate of the solution through the column. The inflow concentrations of PCE and TCE were controlled constant within the range of $0.11{\sim}0.21\;mM$ and $1.3{\sim}1.5\;mM$, respectively. And the contact time was $14{\sim}125$ min for PCE and $15{\sim}36$ min for TCE. The $KMnO_4$ concentration was controlled constant during experiment in the range of $0.6{\sim}2.5\;mM$. It was found that the reduction of PCE and TCE concentrations were inversely proportional to the contact time. The exact reaction order for the PCE and TCE degradation reaction could not be determined under the experimental condition used in this study. However, the estimated reaction rate constants assuming pseudo-1st order reaction agree with those reported based on batch studies. TCE degradation rate was proportional to $KMnO_4$ concentration. This was considered to be the result of using high inflow concentrations of reactant, which might be the case at the vicinity of the source zones in aquifer. The results of this study, performed using a dynamic flow system, are expected to provide useful information for designing and implementing a field scale oxidative removal process for PCE/TCE-contaminated sites.

• Journal of Animal Science and Technology
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• v.52 no.5
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• pp.427-434
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• 2010

This study was conducted to investigate the growth performance and meat quality improvement according to castration, optimal feeding management and ruminally protected amino acid-enriched fatty acid (RPAAFA) for the unselected Hanwoo bulls in the performance test. Bulls were castrated at approximately 14 months of age. Sixteen Hanwoo steers, 15 months of age and weighing $412.9{\pm}24.9kg$, were distributed into 2 groups. Steers were fed a basal diet supplemented with RPAAFA at 0 g (control) or 100 g (treatment), respectively for 12 months. Steers were slaughtered at 27 months of age. Average daily gain for treatment tended to be higher (p=0.10) than that of control, whereas feed conversion ratio tended to be lower (p=0.07) in treatment than in control. The supplementation of RPAAFA did not affect rib eye area, back fat thickness, meat color, fat color, texture and maturity. The appearance rates of yield 'A' grade and high quality grade ($1^{++}$, $1^+$ and 1) were higher in treatment than in control. The content of moisture, fat, protein and ash in longissimus muscles were similar between control and treatment. The supplementation of RPAAFA did not affect water-holding capacity, oxidation and reduction potential, myoglobin and fatty acid contents in longissimus muscles. Thus, present results indicate that castration, optimal feeding management and RPAAFA may be recommended for improving growth performance and quality grade of the unselected Hanwoo bulls in the performance test.

• Korean Journal of Food Science and Technology
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• v.36 no.6
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• pp.937-942
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• 2004

Physicochemical properties and mineral composition of seaweed salts prepared by incineration and osmotic dehydration methods were determined. As the incineration temperature increased, yield of seaweed salts, insoluble solids, pH, alkalinity, and oxidation-reduction potential (ORP) decreased. Alkalinity of salt prepared with sea tangle was higher than that of sea mustard. ORP decreased by incineration above $700^{\circ}C$, and was lower in salt with sea tangle. As incineration temperature increased, amounts of K and Ca in seaweed salt increased, whereas that of Mg decreased. Potassium and Ca contents of seaweed salt increased remarkably compared with those of common salt. Potassium content of sea tangle salt was higher than that of sea mustard. As incineration time increased, yield of seaweed salts, insoluble solid content, and pH decreased, whereas ORP of the salt increased. Potassium content of seaweed salt with incineration time, while Ca and Na contents decreased after incineration of 8 and 4 hr, respectively. Yield of seaweed salt by osmotic dehydration increased as immersion time in sea water increased. pH of salt from sea mustard was higher than that of sea tangle. ORP of seaweed salt dried three times was -128.8 mV, significantly lower than that of salt prepared by incineration method. As sea water immersion time increased, Mg content of seaweed salt increased significantly, while Ca content decreased. Potassium content of seaweed salt was higher in sea tangle salt. In case of salt prepared by incineration of residuals, pH increased with immersion time but ORP decreased.

• Parasites, Hosts and Diseases
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• v.34 no.1
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• pp.59-68
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• 1996

This study investigated the enzyme histochemical localization and characteristics of lactate (LDH) and malate dehydrogenase (MDH) related with the oxidation-reduction metabolism in the sparganum and adult of 5. erinacei. By enzyme histochemical assay, activity of LDH was strong in the tegument and subtegumental muscle layers of the adult and sparganum. Activity of MDH was strong in the tegument of the sparganum and subtegumental muscle layers of the adult. However it was weak in the tegument of the adult. By electrophoresis, 45 kDa band was major and common in LDH of adults and spargana. The 150 kDa molecule was the major and common band in MDH of adults and r -spargana (from experimentally infected rats) . By isoelectrofocusing, isoelectric points (Pl) or 4 MDH isogyme from adult worm were 6.0.6.5, 6.7 and 7.1, respectively. Pl 6.0 was the major band. The active range of pH for MDH was about pH 6-8 and the optimum pH was pH 7 The effective temperature on the MDH was about $30^{\circ}C$∼$50^{\circ}C$ and the optimum temperature was about 40℃ in spargana md adult worm. In the stability against heat, when MDH was heated at 85℃ for 10 seconds, the activity was denatured perfectly. Maximum activity or MDH was 19.4 unit in the s-sparganum (from snakes), 24.5 unit in the r-sparganum (from rats) and 108.0 unit in the adult worm. The maximum activity was higher in adults than in spargana. The present result showed us that the nutrients absorbed through the tegument were transferred into inner tissues and were utilized as the source of metabolism. According to the habitat of the parasite, the isozymes of LDH and MDH are activated differently, and by this different activation the sparganum and adult can adapt themselves to parasitic circumstances.

• Journal of Life Science
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• v.25 no.7
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• pp.740-747
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• 2015

This study was carried out to evaluate changes in the meat quality and antioxidation activity in the loin and ham of Korean Native Black Pigs (KNBP) during frozen storage at −18℃ for 150 days. The pH value of the loin was decreased as storage days progressed, while the pH value of the ham showed no consistent changes with storage days. The lightness (L*) of the loin did not show any significant reduction until day 120, whereas L* of the ham was significantly declined throughout the storage period (p<0.05). The redness (a*) values of the loin and ham were significantly decreased as storage progressed. The water holding capacity of the loin was decreased by day 30 and that value was maintained until the end of storage. The initial total numbers of microorganisms in the loin and ham were 4.88 and 5.16 Log CFU/g, respectively and these numbers were significantly decreased by day 30 (p<0.05). The levels of 2-thiobarbituric acid reactive substances (a measurement of lipid oxidation) in the loin and ham ranged from 0.057-0.069 and 0.052-0.087 mg MDA/kg meat, respectively, until storage day 150. Volatile basic nitrogen values of the loin and ham ranged from 15.13-16.55 and 16.05-16.23 mg%. Oxygen radical absorbance capacities and carnosine contents of the loin and ham were significantly decreased during frozen storage for 3 months (p<0.05). In summary, the meat quality of the loin and ham from KNBP was somewhat decreased during frozen storage. However, the levels of antioxidants and dipeptides with antioxidant activity were significantly decreased in pork loin and ham during frozen storage.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.3
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• pp.329-336
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• 2006

Iron manufacturing process involves production of various by-product including slag, sludge, sintering and EAF(Electric Arc furnace dust). Some of the by-products such as EAF and sintering dust are disposed of as waste due to their high heavy metal contents. It has been notice for many years that the EAF dust also contain about 65% of Fe(0) and Fe(II) and then the possible utilization of the iron. One possibility is to apply the EAF as a lining material in conjunction with clay or HDPE liners, in waste landfill. The probable reaction between the leachate containing toxic elements such as TCE, PCE dioxine and $Cr^{6+}$ is reduction of the toxic materials in corresponding to the oxidation of the reduced iron and therefore diminishing the toxicity of the leachate. It is, however, prerequisite to evaluate the leaching characteristics of the EAF dust before application. Amelioration of the leachate would be archived only when the level of toxic elements in the treated leachate is less than that of in the untreated leachate. Several leaching techniques were selected to cover different conditions and variable environments including time, pH and contact method. The testing methods include availability test, pH-stat test and continuous column test. Cr and Zn are potentially leachable elements among the trace metals. The pH of the EAF dust is highly alkaline, recording around 12 and Zn is unlikely to be leached under the condition. On the contrary Cr is more leachable under alkaline environment. However, the released Cr should be reduced to $Cr^{3+}$ and then removed as $Cr(OH)_3$. Removal of the Cr is observed in the column test and further study on the specific reaction of Cr and EAF dust is underway.

• Journal of the East Asian Society of Dietary Life
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• v.22 no.6
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• pp.851-859
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• 2012

This study was conducted to investigate the effects of addition of lotus (Nelumbo nucifera) leaf and root extracts on the quality and sensory characteristics of ground pork meat. Four types of ground pork were evaluated: 5% ice water added (T0), 5% lotus leaf extract added (T1), 2.5% lotus leaf extract and 2.5% root extract added (T2), and 5% lotus root extract added (T3). There were no significant differences in moisture, protein, fat, ash, cooking yield, moisture retention, water holding capacity, reduction in diameter, a-value (redness), b-value (yellowness), VBN content (volatile basic nitrogen), hardness, springiness, cohesiveness or chewiness. The fat retention was highest in T0 (p<0.05). The L-values (lightness) of T2 and T3 were higher than those of T0 and T1 (p<0.05). The pH was lowest in T1 (p<0.05). The TBARS (2-thiobarbituric acid reactive substances) values of T0, T1, T2, and T3 were 0.47, 0.17, 0.21, and 0.32 mgMA/kg, respectively, with that of T1 being significantly lower than those of the other samples (p<0.05). The contents of free amino acids related to sweet taste was 642.5 ppm for T1, which was highest among the samples (p<0.05). The flavor was highest in T1 (p<0.05). These results suggest that lotus leaf extracts improved the lipid oxidation and flavor of ground pork meat.

• 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.

• Clean Technology
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• v.24 no.1
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• pp.77-84
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• 2018

In this study, $Li_4Ti_5O_{12}$ anode materials for lithium ion battery were synthesized by dry ball-mill method. Polyvinyl chloride (PVC) as a carbon source was added to improve electrochemical properties. When the PVC was added after $Li_4Ti_5O_{12}$ formation, the spinel structure was well synthesized and it was confirmed by X-ray diffraction (XRD) experiments. When the carbon material was added before the synthesis and the heat treatment was performed, it was confirmed that a material having a different crystal structure was synthesized even when a small amount of carbon material was added. In the case of $Li_4Ti_5O_{12}$ without the carbon material, the electrical conductivity value was about $10{\mu}S\;m^{-1}$, which was very small and similar to that of the nonconductor. As the carbon was added, the electrical conductivity was greatly improved and increased up to 10,000 times. Electrochemical impedance spectroscopy (EIS) analysis showed that the size of semicircle corresponding to the resistance decreased with the carbon addition. This indicates that the resistance inside the electrode is reduced. According to the Cyclic voltammetry (CV) analysis, the potential difference between the oxidation peak and the reduction peak was reduced with carbon addition. This means that the rate of lithium ion insertion and deinsertion was increased. $Li_4Ti_5O_{12}$ with 9.5 wt% PVC added sample showed the best properties in rate capabilities of $180mA\;h\;g^{-1}$ at 0.2 C-rate, $165mA\;h\;g^{-1}$ at 0.5 C-rate, and $95.8mA\;h\;g^{-1}$ at 5 C-rate.