• Journal of Korean Society of Environmental Engineers
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• v.22 no.4
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• pp.775-784
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• 2000

Nitrate dry deposition fluxes were directly measured using knife-leading-edge surrogate surface (KSS) covered with greased strips and a water surface sampler (WSS). The average gaseous flux ($8.3mg/m^2/day$) was much higher than the average particulate one ($3.0mg/m^2/day$). The best fit gas phase mass transfer coefficient (MTC) of $HNO_3$ was obtained by linear regression analysis between measured gaseous flux containing nitrogen compounds and measured ambient $HNO_3$ concentration. The result showed that the MTCs of $HNO_3$ were approximately two times higher than those of $SO_2$. Especially, during the ozone action day, measured gaseous fluxes containing nitrogen compounds were much higher than those ones calculated as the product of measured ambient $HNO_3$ concentration and gas phase MTC of $HNO_3$, which is calculated from MTC of $SO_2$ using Graham's diffusion law. This result indicated that other nitrogen compounds except $HNO_3$ contributed to gaseous flux containing nitrogen compounds into the water surface sampler. The theoretical calculations suggest the contributions of nitrous acid ($HNO_2$) and PAN to the gaseous dry deposition flux of nitrogen containing compounds to the WSS.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.7
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• pp.700-704
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• 2008

Nitrite and free ammonia have been known as substrate inhibitors in anaerobic ammonium oxidation. To reduce inhibitory effect of these substrates, the NH$_3$-N/NO$_2$-N ratio in the influent could be properly controlled in anaerobic ammonium oxidation process. Five kinds of NH$_3$-N/NO$_2$-N ratio were assayed in batch to find optimum NH$_3$-N/NO$_2$-N ratio, curtailing substrate inhibition. As the results of batch test, the highest T-N removal efficiency of 88% was obtained at 1.00 : 1.30 of NH$_3$-N/NO$_2$-N ratio. In addition, rate constants for ammonium and nitrite in zero-order kinetics were found to be the highest values as 7.66 mg/L$\cdot$hr and 11.89 mg/L$\cdot$hr at 1.00 : 1.30 ratio, respectively. However, as for the specific anammox activity, the ratio of NH$_3$-N/NO$_2$-N ratio was recommended as 1 : 1.15 which can maintain the highest SAA during continuous operation and preclude the accumulation of nitrite in the reactor.

• Journal of the Korea Institute of Building Construction
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• v.12 no.3
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• pp.275-283
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• 2012

Nitrite-type hydrocalumite (calumite) is a material that can adsorb the chloride ions ($Cl^-$)that cause the corrosion of reinforcing bars and liberate the nitrite ions ($NO_2{^-}$) that inhibit corrosion in reinforced concrete, and can provide a self-corrosion inhibition function to the reinforced concrete. In this study, VA/E/MMA-modified mortars with calumite were prepared with various calumite contents and polymer binder-ratios, and tested for corrosion inhibition, chloride ion penetration, carbonation and drying shrinkage. As a result, regardless of polymer-binder ratio, the replacement of ordinary Portland cement with hydrocalumite has a marked effect on the corrosion inhibiting property of the polymer-modified mortars. However, chloride ion penetration and carbonation depths are somewhat increased with higher calumite content, but can be remarkably decreased depending on the polymer-binder ratios. The 28-d drying shrinkage shows a tendency to increase with the polymer-binder ratio and calumite content. VA/E/MMA-Modified mortars with 10 % calumite did not satisfy KS requirements. Accordingly, a calumite content of 5 % is recommended for the VA/E/MMA-modified mortars with calumite.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2010.05a
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• pp.73-76
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• 2010

This study deals with the properties of polymer-modified mortars with a nitrite-type hydrocalumite, which are effectively used as intelligent patch materials for deteriorated reinforced concrete structures. The calumite is a material that can adsorb the chloride ions (Cl-) causing the corrosion of reinforcing bars and liberate the nitrite ions (NO2-) inhibiting the corrosion in reinforced concrete, and can provide a self-corrosion inhibition function to the reinforced concrete. Polymer-modified mortars using hydrocalumite and terpolymer powders are prepared with various calumite contents and polymer-binder ratios, and tested for corrosion inhibition. Subsequently, regardless of the polymer-binder ratio, the replacement of ordinary portland cement with the calumite has a marked effect on the corrosion-inhibiting property of the polymer-modified mortars.

• Korean Journal of Food Science and Technology
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• v.21 no.5
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• pp.662-668
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• 1989

The effect of four different humidities during smokehouse processing on cured color development color intensity, pH, residual nitrite, phenol deposition, TBA value and product yield of Canadian bacon was determined. High humidity resulted in high pigment conversion and lower pH. As the humidity was lowered, more residual nitrite remained, The highest humidity had the highest phenol deposition and TBA value. The lowest humidity had the highest yield.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.9
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• pp.1035-1043
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• 2007

A leachate containing an elevated concentration of organic and inorganic compounds has the potential to contaminate adjacent soils and groundwater as well as downgradient areas of the watershed. Moreover high-strength ammonium concentrations in leachate can be toxic to aquatic ecological systems as well as consuming dissolved oxygen, due to ammonium oxidation, and thereby causing eutrophication of the watershed. In response to these concerns landfill stabilization and leachate treatment are required to reduce contaminant loading sand minimize effects on the environment. Compared with other treatment technologies, leachate recirculation technology is most effective for the pre-treatment of leachate and the acceleration of waste stabilization processes in a landfill. However, leachate recirculation that accelerates the decomposition of readily degradable organic matter might also be generating high-strength ammonium in the leachate. Since most landfill leachate having high concentrations of nitrogen also contain insufficient quantities of the organic carbon required for complete denitrification, we combined a shortcut biological nitrogen removal (SBNR) technology in order to solve the problem associated with the inability to denitrify the oxidized ammonium due to the lack of carbon sources. The accumulation of nitrite was successfully achieved at a 0.8 ratio of $NO_2^{-}-N/NO_x-N$ in an on-site reactor of the sequencing batch reactor (SBR) type that had operated for six hours in an aeration phase. The $NO_x$-N ratio in leachate produced following SBR treatment was reduced in the landfill and the denitrification mechanism is implied sulfur-based autotrophic denitrification and/or heterotrophic denitrification. The combined leachate recirculation with SBNR proved an effective technology for landfill stabilization and nitrogen removal in leachate.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.2
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• pp.138-144
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• 2005

This study was carried out to investigate the changes of nitrifying bacterial populations including Nitrosomonas sp. and Nitrobacter sp. in $A^2/O$ pilot plant with the configuration of anaerobic-anoxic-oxic reactors. The suspended nitrifying bacterial populations in mixed liquor and those of attached populations on granular carrier surface made by molded waste tire were analyzed by Fluorescent in situ Hybridization(FISH) method. The nitrification rate of a pilot plant showed the value of $1.97{\sim}2.98\;mg\;N/g$ MLVSS hr. The ratios of suspended ammonia oxidizer including Nitrosomonas sp. (NSO) to total bacteria in each reactor were oxic < anoxic < anaerobic. On the contrary, the ratios of suspended nitrite oxidizer including Nitrobacter sp. (NIT) were anaerobic < anoxic < oxic. The thickness, dry density and mass of the attached biomass on granular carriers were $180{\sim}188\;{\mu}m$, $38.5{\sim}43.9\;mg/cm^3$, $29.4{\sim}32.5\;mg/g$, respectively. Also, the ratios of attached nitrifier to total bacteria on granular carriers were similar regardless of ammonia/nitrite-oxidizer (NSO; 3.2%, NIT; 2.8%) and very low compared to those(NSO; $22.8{\sim}28.4%$, NIT; $17{\sim}26%$) of suspended nitrifier.

• Applied Chemistry for Engineering
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• v.21 no.1
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• pp.6-10
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• 2010

In order to research the effect of solvents of extract on biological activities of Phyllostachys nigra Munro, antioxidative activity, superoxide dismutase (SOD)-like activity, nitrite scavenging activity, tyrosinase inhibitory activity, angiotensin-converting enzyme (ACE) inhibibitory activity in vitro were investigated. When ethyl acetate and hexane as solvents were used, the total phenols concentrations were 44.1 and 47.3 mg/kg, respectively, which was about 2.0 fold higher than that of water. The antioxidive activity was affected by solvents of extraction. The antioxidative activity was increased in order of hexane > ethyl acetate > n-butanol > methanol > water extraction. On the other hand, in the case of SOD-like activity, it was in the order of methanol > n-butanol > hexane > ethyl acetate extraction. The nitrite scavenging ability showed the most remarkable activity at pH 1.2 irrespective of solvents. Especially, when pH was increased from 1.2 to 6.0 using ethyl acetate extraction, it was decreased from 69.2 to 7.8%. The tyrosinase inhibitory activity was in the range of 15.2~21.3% and was increased in order of water > methanol > n-butanol>hexane > ethyl acetate extract. These results suggest that hexane and ethyl acetate extraction of Phyllostachys nigra Munro can be used in bioactive and functional materials.

• Journal of Life Science
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• v.12 no.6
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• pp.654-660
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• 2002

This study was carried out to investigate the effect of addition of perilla leaf(PL) powder and carcass grade on the surface color, residual nitrite and shelf-life of pork sausage. Pork sausage was prepared by four type such as grade B pork sausage(A sausage), grade B pork sausage containing perilla leaf(B sausage), grade I pork sausage(C sausage) and grade I pork sausage containing perilla leaf(D sausage) and the surface color, residual nitrite, pH, volatile basic nitrogen(VBN), thiobarbituric acid reactive substances(TBARS) and total bacterial counts of the samples were determined during storage at 4$^{\circ}C$. $L^*$ value of pork sausage showed the highest early stage of storage, pork sausage containing PL was lower than pork sausage without PL. The $a^*$ value of A sausage had the lowest on the storage of 8th week, B sausage had the highest on the storage of 4th week, and the $a^*$ value of C and D sausage were not significantly different during storage. The$a^*$ value of pork sausage containing PL was lower than pork sausage without PL, the $b^*$ value was higher than pork sausage without PL. The residual nitrite of pork sausage containing PL highly decreased until storage for 2 weeks, pork sausage without PL highly decreased until storage for 4 weeks, therefore addition of PL was affected in the reduction of residual nitrite of pork sausage. The pH of A and B sausage decreased until storage at 4 weeks, but increased from 6 weeks. The VBN contents were 6.7~8.4 mg% in the early stage of storage, was 16.1~19.5 mg% on the storage of 8th weeks. The TBARS of pork sausage were increased gradually during storage. Pork sausage containing PL showed lower value than pork sausage non added PL during storage. The total bacterial counts of pork sausage were increased gradually during storage, pork sausage containing PL was lower than that of free PL during storage.

• Microbiology and Biotechnology Letters
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• v.31 no.4
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• pp.362-367
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• 2003

Coriolus versicolor was grown in a defined synthetic liquid medium and citrus extracts, and the culture extracts were examined for antioxidant activity, nitrite scavenging activity, and in vitro anticancer activity against HeLa, PC-3, HepG2, and A-549 cells. Whereas the culture extracts obtained from the synthetic medium and the un-inoculated citrus extract showed 60 and 22％ of the 1,1-diphenyl-2-picrylhydrazyl radical scavenger activity, the culture extracts obtained from the citrus extracts medium exhibited antioxidant activity up to 89％. The nitrite scavenging activity of the culture extracts obtained from the citrus extracts medium and the synthetic liquid medium, and the un-inoculated citrus extract at pH 1.2 were up to 67, 55, and 34％, respectively. The culture extract obtained from the synthetic liquid medium inhibited the growth of HeLa, PC-3, HepG2, and A-549 up to 66, 23, 18, 10％ at 48 h of incubation, respectively; however, the culture extract obtained from the citrus extracts medium inhibited the growth of HeLa, PC-3, HepG2, and A-549 up to 75, 82, 55, and 82％, respectively. As a negative control, the un-inoculated citrus extract was examined in the same way and inhibited the growth of HeLa, PC-3, and HepG2 cells 20, 6, and 15％ at 48 h incubation, respectively; the inhibition of A-549 cell growth was negligible. These results clearly showed that the fermentation of C. versicolor in the citrus extracts rather than in the defined synthetic medium significantly enhanced the anticancer activity, antioxidant activity, and nitrite scavenging activity.