• Journal of Korean Society of Environmental Engineers
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• v.22 no.4
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• pp.671-678
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• 2000

Reaction characteristics of simultaneous removal of SOx and NOx have been investigated in a thermogravimetric analyzer and tubular fixed bed reactor using the $CuO/{\gamma}-Al_2O_3$ sorbent/catalyst. Sulfur removal capacity of $CuO/{\gamma}-Al_2O_3$ sorbent/catalyst is largely enhanced above both the temperature of $450^{\circ}C$ and the loading of 6wt% due to the participation of alumina support in a sulfation reaction. The NO reduction efficiency of 8wt% $CuO/{\gamma}-Al_2O_3$ sorbent/catalyst shows the maximum value at $370^{\circ}C$ and then decreases with the increase of reaction temperature due to the oxidation of $NH_3$ gas. The presence of sulfate on the surface of sorbent/catalyst enhances the optimum reaction temperature showing the maximum deNOx efficiency. In the simultaneous removal of SOx and NOx at $250^{\circ}C$. deNOx activity of $CuO/{\gamma}-Al_2O_3$ sorbent/catalyst is rapidly decreased due to the formation of ammonium salts such as $NH_4HSO_4$. In the simultaneous removal reaction of SOx and NOx, the optimum temperature showing the maximum deNOx efficiency increases to $400^{\circ}C$ due to the presence of $SO_2$ gas.

• Journal of Life Science
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• v.20 no.7
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• pp.1034-1040
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• 2010

Plants and their extracts can be utilized as inexpensive and rich resources of active constituents in the cosmetic field, as well as the food, pharmaceutical and medicinal fields. Until now, Aster glehni Fr. Schm. had no known active effect, except on anti-oxidation, that was found during investigations for application in the cosmetic field. In this study, we examined the inhibition of enzymatic reactions to protein levels in inclusive B16F10 melanoma cell lines. Significant inhibition of enzymatic reactions was observed in the EtOAc extract, which advanced to tyrosinase protein and TRP-1 in the B16F10 melanoma cell line. These results indicated that the effect of EtOAc extract inhibited expressions of tyrosinase protein and TRP-1 in the B16F10 melanoma cell line by 30.5% and 41.5% at 100ug/ml respectively. On the other hand, antimicrobial activity was evaluated to the four fractions in normal flora of the skin. Hexane extract was only exhibited in the higher clear zone in all strains. In conclusion, any cosmeceutical effects of Aster glehni Fr. Schm. may have a potential meaning, as well as possible value for further studies regarding the effects of chemical constituents of Aster glehni Fr. Schm.

• Korean Journal of Materials Research
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• v.11 no.6
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• pp.453-459
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• 2001

It is important for the fabrication of nuclear cladding to optimize the microstructure, because the properties of Zr-based nuclear claddings such as mechanical properties, oxidation-resistance and corrosion- resistance vary widely with its microstructure. The microstructure in Zr-based alloy is strongly dependent on the solubility of alloying element. However, it is very difficult to measure the solubility due to the low solution limit of alloying elements in Zr-based alloy. In this study, Thermoelectric Power(TEP) measurements are used to determine the solubility of Nb in Zr-0.8Sn alloy, which is confirmed by optical microscopy and transmission electron microscopy. The solutioning of Nb obtained by a homogenization treatment and water-quench leads to a decrease of TEP The saturation of TEP appears with the increase of homogenization temperature, which means the saturation of the Nb content in the matrix. From these results, the solubility ($C_{Nb}$) of Nb in Zr-0.8Sn with temperature could be expressed as fellow equation : $4.69097{\times}10^{16}{\times}e^{-25300\times\;I/T}$(ppm.at.%)

• Journal of the Korean GEO-environmental Society
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• v.8 no.4
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• pp.19-25
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• 2007

Process analysis with ASM3 (Activated Sludge Model3) was performed to offer basic data for the optimization of aerated biofilter (ABF) process design and operation. This study was focused on the simulation of the nitrification reaction in ABF which was a part of the advanced nutrient treatment process using bio-adsorption. The ABF process has been developed for the removal of suspended solids and nitrification reaction in sewage. A GPS-X (General Purpose Simualtor-X) was used for the sensitivity analysis and operation assessment. Sensitivity of ASM3 parameters on ABF was analysed and 4 major parameters ($Y_A$, $k_{sto}$, ${\mu}_A$, $K_{A,HN}$) were determined by dynamic simulation using 70 days data from pilot plant operation. The optimized values were 0.14 for $Y_A$, 3.5/d for $k_{sto}$, 2.7/d for ${\mu}_A$ and 1.1 mg/L for $K_{A,HN}$, respectively. Simulation with optimized parameter values were conducted and TN, $NH_4{^+}-N$ and $NO_3{^-}-N$ concentrations were estimated and compared with measured data at the range of 10 min to 4 hrs of hydraulic retention time (HRT). The simulated results showed that optimized parameter values could represent the characteristics of ABF process. Especially, the ABF showed relatively high nitrification rate (60%) under very short HRT of 10 min. As a consequence, the ABF was thought to be successfully used in the site which having high variation of influent loading rate.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.9
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• pp.4274-4282
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• 2011

In this study, Fenton reaction was studied for the possibility of applying as advanced treatment and its optimal condition for the removal of refractory organics from the dye wastewater. Fenton reaction was applied to remove refractory organics after the bio-treatment (secondary treatment) inside test laboratory and on-site pilot plant. Wastewater from the secondary treatment was used and its $COD_{Mn}$ was measured as 30~50mg/L. After the Fenton reaction, the optimal condition was found as pH 3~3.5, reaction time 2~2.5hr, chemical input ratio of ($FeCl_2$(33%)/$H_2O_2$(35%)) was 3 : 1. When chemical input ratio of ($FeCl_2$(33%)/$H_2O_2$(35%)) was at its optimal, amount of sludge volume ($SV_{2hr}$) was 21~28%. With pilot plant test, removal rate was heavily influenced by the hydraulic retention time(HRT), and optimum value of HRT was 2.0 hr. When pilot plant($2m^3/d$) was placed on-site and operated continuously, it showed steady and fairly good treatment of COD where COD removal rate was 60~70%, treated water showed below 20mg/L.

• Journal of the Korea Organic Resources Recycling Association
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• v.29 no.3
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• pp.5-16
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• 2021

In this study, the applicability of the MBR(Membrane Bio Reactor) process of oxygen dissolve was evaluated through comparison and evaluation of the efficiency of oxygen dissolve device and conventional aeration device in the explosive tank within the MBR process. The organic matter and ammonia oxidation by oxygen dissolve device were evaluated, and the efficiency of persaturation was evaluated by applying real waste water (anaerobic digester effluent treatement from food waste). SCOD and ammonia removal rates for oxygen dissolve device and conventional aeration device methods were similar. However, it was determined that the excess sludge treatment cost could be reduced as the yield of microorganisms by oxygen dissolve device is about 0.03 g MLSS-produced/g SCOD-removed lower than that of microorganisms by conventional aeration device. The removal rates of high concentrations of organic matter (4,000 mg/L) and ammonia (1,400 mg/L) in anaerobic digester effluent treatment from food waste were compared to the conventional aeration device and the oxygen dissolve device organic matter removal rate was approximately 13% higher than that of the conventional aeration device. In addition, for MLSS, the conventional aeration device was 0.3 times higher than for oxygen dissolve device. This is believed to be due to the high progress of sludge autooxidation because the dissolved oxygen is sufficiently maintained and supplied in the explosive tank for oxygen dissolve device. Therefore, it was determined that the use of oxygen dissolve device will be more economical than conventional aeration device as a way to treat wastewater containing high concentrations of organic matter.

• Animal Bioscience
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• v.37 no.3
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• pp.522-535
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• 2024

Objective: Transition period is considered from 3 weeks prepartum to 3 weeks postpartum, characterized with dramatic events (endocrine, metabolic, and physiological) leading to occurrence of production diseases (negative energy balance/ketosis, milk fever etc). The objectives of our study were to analyze the periodic concentration of serum beta-hydroxy butyric acid (BHBA), glucose and oxidative markers along with identification, and validation of the putative markers of negative energy balance in buffaloes using in-silico and quantitative real time-polymerase chain reaction (qRT-PCR) assay. Methods: Out of 20 potential markers of ketosis identified by in-silico analysis, two were selected and analyzed by qRT-PCR technique (upregulated; acetyl serotonin o-methyl transferase like and down regulated; guanylate cyclase activator 1B). Additional two sets of genes (carnitine palmotyl transferase A; upregulated and Insulin growth factor; downregulated) that have a role of hepatic fatty acid oxidation to maintain energy demands via gluconeogenesis were also validated. Extracted cDNA (complementary deoxyribonucleic acid) from the blood of the buffaloes were used for validation of selected genes via qRTPCR. Concentrations of BHBA, glucose and oxidative stress markers were identified with their respective optimized protocols. Results: The analysis of qRT-PCR gave similar trends as shown by in-silico analysis throughout the transition period. Significant changes (p<0.05) in the levels of BHBA, glucose and oxidative stress markers throughout this period were observed. This study provides validation from in-silico and qRT-PCR assays for potential markers to be used for earliest diagnosis of negative energy balance in buffaloes. Conclusion: Apart from conventional diagnostic methods, this study improves the understanding of putative biomarkers at the molecular level which helps to unfold their role in normal immune function, fat synthesis/metabolism and oxidative stress pathways. Therefore, provides an opportunity to discover more accurate and sensitive diagnostic aids.

• Solar Energy
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• v.20 no.2
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• pp.43-54
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• 2000

We prepared and characterized $Cu(In_{1-x}Ga_x)Se_2$(CIGS) films using a elemental co-evaporation method for absorbing layer of high efficiency thin film solar cells. The CIGS films deposited on a soda-lime glass exhibited low resistivity because of higher carrier concentration. Na was accumulated at the CIGS surface and the 0 and Se were also accumulated at the surface, suggesting that oxidation is a driving force of Na accumulation. The structure of CIGS film was modified or a secondary phase was formed in the Cu-poor CIGS bulk films probably due to the incorporation of Na into Cu vacancy sites. As the Ga/(In+Ga) ratio increased, the diffraction peaks of $Cu(In_{1-x}Ga_x)Se_2$ films were shifted to larger angle and splitted, and the grain size of $Cu_{0.91}(In_{1-x}Ga_x)Se_2$ films became smaller. All $Cu_{0.91}(In_{1-x}Ga_x)Se_2$ films showed the p-type conductivity regardless of the Ga/(In+Ga) ratio. Ag/n-ZnO/i-ZnO/CdS/$Cu_{0.91}(In_{0.7}Ga_{0.3})Se_2$/Mo solar cells were fabricated. The currently best efficiency in this study was 14.48% for $0.18cm^2$ area ($V_{oc}=581.5mV,\;J_{sc}=34.88mA$, F.F=0.714).

• Journal of the Korean GEO-environmental Society
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• v.13 no.5
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• pp.5-12
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• 2012

Antibiotics have been considered emerging compounds due to their continuous input and persistence in environment. Due to the limited biodegradability and widespread use of these antibiotics, an incomplete removal is attained in conventional wastewater treatment plants and relative large quantities are released into the environment. In this study, it was determined the adsorption and photocatalysis kinetics of antibiotics (Sulfamethoxazole, SMX) with various catalyst (Titanium dioxide; $TiO_2$, Hydroxyapatite; HAP) conditions under UV/$TiO_2$/HAP system. In addition, the statistical analysis of response surface methods (RSM) was used to determine the effects of operating parameters on UV/$TiO_2$/HAP system. $TiO_2$/HAP adsorbent were found to follow the pseudo second order reaction in the adsorption. In the result of applied intrapaticle diffusion model, the constants of reaction rate were $TiO_2$=$0.064min^{-1}$, HAP=$0.2866min^{-1}$ and $TiO_2$/HAP=$0.3708min^{-1}$, respectively.The result of RSM, term of regression analysis in analysis of variance (ANOVA) showed significantly p-value (p<0.05) and high coefficients for determination values($R^2$=96.2%, $R^2_{Adj}$=89.3%) that allowed satisfactory prediction of second order regression model. And the estimated optimal conditions for Y(Sulfamethoxazole removal efficiency, %) were $x_1$(initial concentration of Sulfamethoxazole)=-0.7828, $x_2$(amount of catalyst)=0.9974 and $x_3$(reation time)=0.5738 by coded parameters, respectively. According to the result of intraparticle diffusion model and photocatalysis experiments, it was shown that the $TiO_2$/HAP was more effective system than conventional AOPs(advanced oxidation processes, UV/$TiO_2$ system).

• Journal of Korean Society of Environmental Engineers
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• v.38 no.12
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• pp.647-655
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• 2016

Lead dioxide ($PbO_2$) is an electrode material that is effective for organic pollutant degradation based on hydroxyl radical ($^{\bullet}OH$) attack. Representative parameters for $PbO_2$ electrodeposition are summarized to current, temperature, reaction time, concentration of Pb(II) and electrolyte agent. In this study, $Ti/PbO_2$ electrodes were fabricated by electrodeposition method under controlled reaction time, current density, temperature, concentration of $HNO_3$ electrolyte. Effects of deposition parameters on $^{\bullet}OH$ evolution were investigated in terms of electrochemical bleaching of p-Nitrosodimethylaniline (RNO). As major results, the $^{\bullet}OH$ evolution was promoted at the $PbO_2$ that was deposited in longer reaction time (1-90 min), lower current density ($0.5-50mA/cm^2$), higher temperature ($5-65^{\circ}C$) and lower $HNO_3$ concentration (0.01-1.0 M). Especially, the $PbO_2$ which was deposited in 0.01 M of lowest $HNO_3$ concentration by applying $20mA/cm^2$ for above 10 min was most effective on $^{\bullet}OH$ evolution. The performance gap between $PbO_2$s that was best and worst in $^{\bullet}OH$ evolution was about 41%. Among the properties of $PbO_2$ related on $^{\bullet}OH$ evolution performance, conductivity of $Ti/PbO_2$ significantly influenced on $^{\bullet}OH$ evolution. The increase in conductivity promoted $^{\bullet}OH$ evolution. In addition, the increase in crystal size of $PbO_2$ interfered $^{\bullet}OH$ evolution at surface of some $PbO_2$ deposits.