• Journal of Food Hygiene and Safety
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• v.32 no.1
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• pp.75-81
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• 2017

For people who have a food allergy the only way to manage the allergy is to avoid the food allergen. The mackerel is one of the major food allergens, but no immunoassay for the rapid and simple detection of mackerel has been reported. The objectives of this study are to develop and characterize monoclonal antibodies (MAbs) specific to mackerel using thermal stable-soluble proteins (TSSP) as an immunogen and to characterize the MAbs by indirect enzyme-linked immunosorbent assay (iELISA). The mice immunized with mackerel TSSP and showing high titer were used for cell fusion and cloning. The characterization of MAbs produced from hybridoma cells obtained was confirmed by indirect ELISA and western blot. Four MAbs were confirmed to be specific to mackerel without cross-reaction to other marine products and livestock products in the both methods. The iELISA and western blot based on the MAbs can sensitively detect 1% mackerel protein in other marine products. These results support that immunochemical methods based on the MAb produced could be used as rapid means to detect low levels of mackerel and to identify mackerel adulterated in food.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.12
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• pp.1371-1380
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• 2007

Study on the instability of waste plastic's thermal pyrolysis oil was carried out for the purpose of improving its quality. The reaction of pyrolysis oil with ozone changed double bonds into aldehydes and ketone, estimated that HDPE pyrolysis oil contained $\sim45$ wt% 1-alkene type olefins, and PP pyrolysis oil did $\sim73$ wt% olefins, which consisted of $\sim47$ wt% secondary and $\sim20$ wt% primary alkenes. The dark brown color and odor of pyrolysis oil were improved by eliminating double bonds, indicated that they were directly related to unsaturated hydrocarbons. Container test showed that metal can affected oil quality worse than the brown glass bottle. Antioxidant added into pyrolysis oil was consumed up to 90% within $2\sim3$ days and the wt. composition of unsaturated hydrocarbons in pyrolysis oil was not changed within 50 days, inferring that instability of pyrolysis oil due to unsaturated bonds can be stabilized by antioxidants. Adsorption test on silica gel, activated carbon and alumina to remove precipitates in oil produced a good result, but not enough to remove moisture. However, cheap anhydrous sodium carbonate showed the best removal efficiency of moisture as well as precipitates in oil. Therefore the pyrolysis oil quality improvement was accomplished by applying anhydrous $Na_2CO_3$ into the production plant.

• Journal of the Korean Electrochemical Society
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• v.5 no.2
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• pp.52-56
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• 2002

Tin oxide was coated on graphite particle by sol-gel method and an electrode with this material having microcrystalline structure for lithium ion battery was obtained by heat treatment in the range $400-600^{\circ}C$. The content of tin oxide was controlled within the range of $2.25wt\%\~11.1wt\%$. The discharge capacity increased with the content of tin oxide and also initial irreversible capacity increased. The discharge capacity of tin oxide electrode showed more than 350 mAh/g at the initial cycle and 300 mAh/g after the 30th cycle in propylene carbonate(PC) based electrolyte whereas graphite electrode without surface modification showed 140 mAh/g. When the charge and discharge rate was changed from C/5 to C/2, The discharge capacity of tin oxide and graphite electrode showed $92\%\;and\;77\%$ of initial capacity, respectively. It has been considered that such an enhancement of electrode characteristics was caused because lithium $oxide(Li_2O)$ passive film formed from the reaction between tin oxide and lithium ion prevented the exfoliation of graphite electrode and also reduced tin enhanced the electrical conduction between graphite particles to improve the current distribution of electrode.

• Economic and Environmental Geology
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• v.41 no.2
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• pp.183-199
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• 2008

This study is focused on characterization of the physio-chemical and mineralogical properties, investigation of their vertical changes in the tailing profile of the Guryoung mining area, classification of the profile into distinct zones, and condition conceptual model of physio-chemical conditions and phases-water relationships controlling the element behaviors in the tailings. The upper part of the groundwater is characterized by the high contents of $Fe_2O_3$ and $SO_3$ for whole rock analysis, low pH, and the occurrence of jarosite, schwertmannite and Fe-oxyhydroxide as the secondary mineral phases. The tailing profile can be divided into the covering soil, jarosite zone, Fe-sulfate zone, Fe-oxyhydroxide and gypsum-bearing pyrite zone, calcite-bearing pyrite zone, soil zone, and weathered zone on the based of the geochemical and mineralogical characteristics. The profile can be sampled into the oxidized zone and the carbonate-rich primary zone with the dramatic changes in pH and the secondary mineral phases. The conceptual model proposed for the tailing profile can be summarized that the oxidation of pyrite is the most important reaction controlling the changes in pH, the dissolution of the primary silicates and carbonates, the precipitation of secondary mineral phases, acid-neutralizing, and heavy metal behaviors through the profile.

• Journal of Food Hygiene and Safety
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• v.33 no.3
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• pp.185-192
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• 2018

The purpose of this study was to develop an indirect enzyme-linked immunosorbent assay (indirect ELISA) based on a monoclonal antibody (MAb) that is specific to mackerel thermal stable-soluble protein (TSSP), that can be used for the rapid detection of mackerel in processed marine foods. Among the four MAbs (3A5-1, 2, 9, and 12) developed in previous studies, the 3A5-2 MAb that showed high specificity and sensitivity were selected and used to develop the indirect ELISA method. The detection range of the indirect ELISA was 0.02%-0.001% and the detection limit of 0.001% was shown. No cross-reaction to other marine products and food ingredients was observed by the indirect ELISA. Processed marine foods containing mackerel with ${\geq}0.3$ O.D. value at 405 nm were estimated as positive samples by the indirect ELISA. Therefore, the indirect ELISA can be used as a rapid and sensitive method to identify mackerel authenticity and adulteration in processed marine foods.

• Journal of the Korean Chemical Society
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• v.33 no.1
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• pp.37-45
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• 1989

Voltammetric behavior of alkylammonium ion was studied in the absence and in the presence of crown ether in propylene carbonate as solvent. The peak potentials and the peak currents, their dependency on the concentrations, the reversibility of the electrode reactions are described. In the presence of crown ether chemical reaction might be preceeded before the electron-transfer process, the peak potential for the reduction shifts at the negative direction as the concentration of crown ether to the electrolyte solution increases. The addition of crown ether(20mM 18CR6)to the electrolyte solution made it possible to determine voltammetrically the dialkylammonium ions($Me_2NH^{+}_{2};O.6{\sim}0.8mM$) in the presence of the monoalkylammonium ions ($EtNH^{+}_{3} ;1.6mM$) and the monoalkylammonium ions ($EtNH^{+}_{3} ; 0.5{\sim}2.5mM$) in the presence of the dialkylammonium ions($Me_2NH^{+}_{2};0.5mM$)

• Resources Recycling
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• v.28 no.4
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• pp.30-36
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• 2019

In this study, Li powder was recovered from the by-product of LNO ($Li_2NiO_2$) process, which is the positive electrode active material of waste lithium ion battery, through the $CO_2$ thermal reaction process. In the process of recovering Li powder, the $CO_2$ injection amount is 300 cc/min. The $Li_2NiO_2$ award was phase-separated into the $Li_2CO_3$ phase and the NiO phase by holding at $600^{\circ}C$ for 1 min. After this, the collected sample:distilled water = 1:50 weight ratio, and after leaching, the solution was subjected to vacuum filtration to recover $Li_2CO_3$ from the solution, and the NiO powder was recovered. In order to increase the purity of Ni, it was maintained in $H_2$ atmosphere for 3 hours to reduce NiO to Ni. Through the above-mentioned steps, the purity of Li was 2290 ppm and the recovery was 92.74% from the solution, and Ni was finally produced 90.1% purity, 92.6% recovery.

• Resources Recycling
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• v.32 no.3
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• pp.9-17
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• 2023

Efforts are currently underway to develop a method for efficiently recovering lithium from the cathode material of waste lithium iron phosphate batteries (LFP). The successful application of lithium battery recycling can address the regional ubiquity and price volatility of lithium resources, while also mitigating the environmental impact associated with both waste battery material and lithium production processes. The isomorphic substitution leaching process was used to recover lithium from spent lithium iron phosphate batteries. Lithium was leached by the isomorphic substitution of Fe²⁺ in LFP using a relatively inexpensive ferric chloride etching solution as a leaching agent. In the study, the leaching rate of lithium was compared using the ferric chloride etching solution at various multiples of the LFP molar ratio: 0.7, 1.0, 1.3, and 1.6 times. The highest lithium leaching rate was shown at about 98% when using 1.3 times the LFP molar ratio. Subsequently, to eliminate Fe, the leachate was treated with NaOH. The Fe-free solution was then used to synthesize lithium carbonate, and the harvested powder was characterized and validated. The surface shape and crystal phase were analyzed using SEM and XRD analysis, and impurities and purity were confirmed using ICP analysis.

• Applied Chemistry for Engineering
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• v.26 no.5
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• pp.557-562
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• 2015

In order to analyze and compare the desulfurization characteristics of five different kinds of domestic limestons, a thermogravimetric analyzer (TGA) was used in this study. Calcium carbonate contents of the domestic limestone varied from 91 to 96 wt%. Experimental temperature and sulfur dioxide concentration of $850^{\circ}C$ and 2,750 ppm, respectively were selected to simulate commercial operation conditions. In this study, the calcination and desulfurization reaction of limestones were simultaneously occurred and investigated to simulate in-situ desulfurization reaction in commercial circulating fluidized bed combustors. In addition, desulfurization reactivities of limes having the average particle sizes of 37.5, 90.5, 159, 356 and $750{\mu}m$ were investigated. Desulfurization reactivities via simultaneous calcination and desulfurization reactions were 5-20% lower than those of using general desulfurization reactions.

• Environmental Engineering Research
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• v.20 no.1
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• pp.73-78
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• 2015

The aim of this study was to examine the phosphate (P) removal by quintinite from aqueous solutions. Batch experiments were performed to examine the effects of reaction time, temperature, initial phosphate concentration, initial solution pH and stream water on the phosphate adsorption to quintinite. Kinetic, thermodynamic and equilibrium isotherm models were used to analyze the experimental data. Results showed that the maximum P adsorption capacity was 4.77 mgP/g under given conditions (initial P concentration = 2-20 mgP/L; adsorbent dose = 1.2 g/L; reaction time = 4 hr). Kinetic model analysis showed that the pseudo second-order model was the most suitable for describing the kinetic data. Thermodynamic analysis indicated that phosphate sorption to quintinite increased with increasing temperature from 15 to $45^{\circ}C$, indicating the spontaneous and endothermic nature of sorption process (${\Delta}H^0=487.08\;kJ/mol$; ${\Delta}S^0=1,696.12\;J/(K{\cdot}mol)$; ${\Delta}G^0=-1.67$ to -52.56 kJ/mol). Equilibrium isotherm analysis demonstrated that both Freundlich and Redlich-Peterson models were suitable for describing the equilibrium data. In the pH experiments, the phosphate adsorption to quintinite was not varied at pH 3.0-7.1 (1.50-1.55 mgP/g) but decreased considerably at a highly alkaline solution (0.70 mgP/g at pH 11.0). Results also indicated that under given conditions (initial P concentration=2 mgP/L; adsorbent dose=0.8 g/L; reaction time=4 hr), phosphate removal in the stream water (1.88 mgP/g) was lower than that in the synthetic solution (2.07 mgP/g), possibly due to the presence of anions such as (bi)carbonate and sulfate in the stream water.