• Applied Chemistry for Engineering
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• v.8 no.5
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• pp.790-795
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• 1997

Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofuransfurans are the archetype of toxic chemicals. So it has absorbed public attention. The majors primary sources of PCDDS and PCDFs are chemical, thermal and photochemical reactions. Municipal solid waste incinerator facilities has been reported as the major contributors of dioxins to the environment. In this paper, Dioxins and furans were examined emission gas and fly ash produced during combustion in municipal solid waste incinerator. More effective method for sampling, extraction was described. The sample was extracted using a soxhlet method and purified using silicagel, alumina and carbon fibre HPLC to remove interfering compound. The extract was then analyzed by HRGC/HRMS. The result of this study showed recovery standard was good and the data resembled those of thermal processes. Total dioxins and furans were $1076.20pg/Nm^3$ and $1452.34pg/Nm^3$ respectively. The amount of highly chlorinated compound was more than that of lowly chlorinated compound. The 2,3,7,8-substituted TCDD was Just 0.34% of the total dioxins/furans amount.

• Applied Chemistry for Engineering
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• v.29 no.3
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• pp.356-361
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• 2018

It is common to analyze volatile organic compound (VOC) or semi-VOC (SVOC) in a sample composed of a complex matrix consisting of multiple components such as bloods through a separation process. Adsorption is a physical phenomenon in which certain components accumulate on the surface of other phases. In order to overcome difficulties in the pretreatment process, an adsorption is frequently used. Solid phase microextraction (SPME) equipment with porous carbon carboxen (CAR) is an example of adsorption application. In this study, the adsorption of 4-octylphenol to carboxen was examined. To do so, the extraction efficiency for such solvents as dichloromethane ($CH_2Cl_2$, DCM), ethylacetate ($CH_3COOC_2H_5$, EA) and diethylether ($C_2H_5OC_2H_5$, $Et_2O$) was studied and also the derivatization reaction for 4-octylphenol with reagents of bistrimethylsilyltrifluoroacetamide (BSTFA), methylchloroformate (MCF) and pentafluorobenzylbromide (PFBBr) was compared. The combination of DCM and BSTFA showed good performance thus they were adopted for this study. Thermodynamic adsorption experiments showed that the adsorption process was endothermic and Freundlich isotherm equation was more suitable than Langmuir isotherm. It was also found that the adsorption followed a pseudo-$2^{nd}$ order kinetic model.

• Journal of the Korean Electrochemical Society
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• v.15 no.1
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• pp.19-26
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• 2012

SEI (solid electrolyte interphase) layers are generated on a graphite negative electrode from three different electrolytes and low-temperature ($-30^{\circ}C$) charge/discharge performance of the graphite electrode is examined. The electrolytes are prepared by adding 2 wt% of vinylene carbonate (VC) and fluoroethylene carbonate (FEC) into a standard electrolyte solution. The charge-discharge capacity of graphite electrode shows the following decreasing order; FEC-added one>standard>VC-added one. The polarization during a constant-current charging shows the reverse order. These observations illustrate that the SEI film resistance and charge transfer resistance differ according to the used additives. This feature has been confirmed by analyzing the chemical composition and thickness of three SEI layers. The SEI layer generated from the standard electrolyte is composed of polymeric carbon-oxygen species and the decomposition products ($Li_xPF_yO_z$) of lithium salt. The VC-derived surface film shows the largest resistance value even if the salt decomposition is not severe due to the presence of dense film comprising C-O species. The FEC-derived SEI layer shows the lowest resistance value as the C-O species are less populated and salt decomposition is not serious. In short, the FEC-added electrolyte generates the SEI layer of the smallest resistance to give the best low-temperature performance for the graphite negative electrode.

• Composites Research
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• v.30 no.1
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• pp.46-51
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• 2017

Structural battery has been researched extensively to combine the functions of the battery and structure without gravimetric or volumetric increments compared to their individual components. The main idea is to employ carbon fabric as the reinforcement and electrode, glass fabric as the separator, and solid-state electrolyte which can transfer load. However, state-of-the-art solid-state electrolytes do not have sufficient load carrying functionality and exhibiting appropriate ion conductivity simultaneously. Therefore, in this research, a system which has both battery and load carrying capabilities using glass fabric separator and liquid electrolyte was devised and tested to investigate the potential and feasibility of this structural battery system and observe electric properties. It was observed that elongating separator decreased electrical behavior stability. A possible cause of this phenomenon was the elongated glass fabric separator inadequately preventing the penetration of small particles of the cathode material into the anode. This problem was verified additionally by using a commercial separator. The characteristic of the glass fabric and the interface between the electrode and glass fabric needed to be further studied for the realization of such a load carrying structural battery system.

• Journal of the Korea Organic Resources Recycling Association
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• v.1 no.2
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• pp.227-235
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• 1993

This study was carried out to evaluate the possibility of composting for organic solid waste from restaurants and domestics. Small three vessels were prepared which were conditioned to semianaerobic, convectional and air-blowed type. During the experiment period for 4 months, the values of volatile solid(VS) %, moisture % and carbon/nitrogen (C/N) ratio of the wastes in the vessels were stabilized, 80 % to 40-50 %, 80 % to 48-55 % and 18 to 8-10, respectively. On the basis of VS % and C/N ratio, the reactions were more adaptable to 2nd order formula than to 1st order one, Reaction rate constant of the 3 vessels were estimated, $4.96{\times}10^{-5}(day^{-1})$ in the semianaerobic type, $5.82{\times}10^{-5}(day^{-1})$ in the convectional type and $8.42{\times}10^{-5}(day^{-1})$ in the air-blowed type on VS. Compared reaction rate constants(k), it can be said that composting period shorten if air is supplied artificially and that vessels simular to those of this study are useful for household organic waste at the backyards.

• Mycobiology
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• v.37 no.1
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• pp.53-61
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• 2009

The process of biodegradation in lingo-cellulosic materials is critically relevant to biospheric carbon. The study of this natural process has largely involved laboratory investigations, focused primarily on the biodegradation and recycling of agricultural by-products, generally using basidiomycetes species. In order to collect super white rot fungi and evaluate its ability to degrade lingo-cellulosic material, 35 fungal strains, collected from forests, humus soil, livestock manure, and dead trees, were screened for enzyme activities and their potential to decolorize the commercially used Poly-R 478 dye. In the laccase enzymatic analysis chemical test, 33 white rot fungi and 2 brown rot fungi were identified. The degradation ability of polycyclic aromatic hydrocarbons (PAHs) according to the utilized environmental conditions was higher in the mushrooms grown in dead trees and fallen leaves than in the mushrooms grown in humus soil and livestock manure. Using Poly-R 478 dye to assess the PAH-degradation activity of the identified strains, four strains, including Agrocybe pediades, were selected. The activities of laccase, MnP, and Lip of the four strains with PAH-degrading ability were highest in Pleurotus incarnates. 87 fungal strains, collected from forests, humus soil, livestock manure, and dead trees, were screened for enzyme activities and their potential to decolorize the commercially used Poly-R 478 dye on solid media. Using Poly-R 478 dye to assess the PAHdegrading activity of the identified strains, it was determined that MKACC 51632 and 52492 strains evidenced superior activity in static and shaken liquid cultures. Subsequent screening on plates containing the polymeric dye poly R-478, the decolorization of which is correlated with lignin degradation, resulted in the selection of a strain of Coriolus versicolor, MKACC52492, for further study, primarily due to its rapid growth rate and profound ability to decolorize poly R-478 on solid media. Considering our findings using Poly-R 478 dye to evaluate the PAH-degrading activity of the identified strains, Coriolus versicolor, MKACC 52492 was selected as a favorable strain. Coriolus versicolor, which was collected from Mt. Yeogi in Suwon, was studied for the production of the lignin-modifying enzymes laccase, manganese-dependent peroxidase (MnP), and lignin peroxidase (LiP).

• Composites Research
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• v.30 no.6
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• pp.384-392
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• 2017

Sandwich panels with three different joint configurations were tested to design a novel sandwich joint structure that can effectively support both the tensile and compressive loads. The sandwich core was mainly aluminum flex honeycomb but the PMI foam core was limitedly applied to the ramp area which is transition part from sandwich to solid laminate. The face of sandwich panel was made of carbon fiber composite. For configuration 1, the composite flange and the sandwich panel were cocured. For configurations 2 and 3, an aluminum flange was fastened to the solid laminate by HI-LOK pins and adhesive. The average compressive failure loads of configurations 1, 2, and 3 were 295, 226, and 291 kN, respectively, and the average tensile failure loads were 47.3 (delamination), 83.7 (bolt failure), and 291 (fixture damage) kN, respectively. Considering the compressive failure loads only, both the configurations 1 and 3 showed good performance. However, the configuration 1 showed delamination in the corner of the composite flange under tension at early stage of loading. Therefore, it was confirmed that the structure that can effectively support tension and compressive loads at the same time is the configuration 3 which used a mechanically fastened aluminum flange so that there is no risk of delamination at the corner.

• Analytical Science and Technology
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• v.15 no.5
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• pp.475-481
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• 2002

The determination of phthalates and adipate in natural mineral water and its container is described. Phthalates and adipate were extracted from natural mineral water by liquid-liquid extraction with methylene chloride, concentrated and then injected in GC-MS (SIM). Phthalates and adipate from 1) PET, cap, label and glue were extracted in Soxhlet with 50 mL of carbon tetrachloride, purified with silicagel and detected with GC-MS (SIM). Peak shapes and quantitation of phthalates and adipate were excellent, with linear calibration curves over a range of $0.1{\sim}10{\mu}g/L$ in water sample ($r^2$ > 0.996) and over a range of $1{\sim}1,000{\mu}g/Kg$ in solid samples ($r^2$>0.994). The detection limits of analytes were $0.002{\sim}0.010{\mu}g/L$ in water and $0.01{\sim}0.02{\mu}g/Kg$ in solid samples. Five kinds of natural mineral water samples, two PETs, two labels, two caps and two glues were quantified by the described procedure. As a results, the concentrations of total phthalates in natural mineral water ranged from ND ~ 1.2 ng/mL. Otherwise, the concentrations of total phthalate extracted from PET ranged from 0.55 ~ 1.2 mg/Kg. We found that the accurate determination of phthalte and adipate in natural mineral water and container must be considered blank correction and the removal of label and glue in PET sample.

• Analytical Science and Technology
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• v.14 no.3
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• pp.274-285
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• 2001

In this study, the thermal desorption-cryofocusing-gas chromatographic(TD-C-GC) method was developed for determination of volatile organic compounds(VOCs) in ambient air and was applied at the municipal solid waste landfill sites. On-column cryofocusing was possible only with a 100 ml dewars bottle in TD-C-GC method with a stainless steel column. However, high operating pressure was needed for purging VOCs from the absorbent trap, which was able to solve by pressure programming with a electric pressure controller. By using both pressure and temperature programming brought increasing of resolution power in on-column cryofocusing method, but the high pressure caused a leakage of sample tube with repeated use. A loop cryofocusing devise was also developed and compared with the direct on-column method. In loop cryofocusing method, VOCs were concentrated on a 0.8mm i.d. loop which is located between the injector and separation column by using liquid nitrogen. In order to purge VOCs from the absorbent trap, only 0.4 psi of pressure was need in the loop cryofocusing method. Dual detection system was applied for the analysis of VOCs; a FID was used for hydrocarbons and a FPD was used for sulfur-containing compounds. Qualitative analysis was done by on-column cryofocusing GC-MS system. Among the large number of VOCs, toluene was the most abundant. Hydrogen sulfide, dimethyl sulfide, carbon disulfide, dimethyl disulfide and methyl propyl disulfide were detected at landfill site by FPD.

• THE JOURNAL OF KOREAN ORIENTAL ONCOLOGY
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• v.8 no.1
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• pp.103-125
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• 2002

This experimental study was carried out to evaluate the anti-tumor and the immunomodulatory effects of Jiaweicitaowan(加未慈桃丸) against cancer. The in vitro anti-tumor effects were evaluated by MTT assay. The cytotoxicity, extension of survival days, the effect of inhibition solid tumor which was induced sarcoma 180, and the changes of body weight were evaluated for in vivo effects of anti-tumor. To evaluate the immunomodulatory effects of Jiawei- citaowan(加未慈桃丸), delayed type hypersensitivity, hemagglutinin, hemolysin titers for humoral immune response, rosette forming cells for cell-mediated immune response, natural killer cell activity, proliferation of lymphocyte, productivty of Interleukin-2, and carbon clearance were measured with methotrexate treated mice. The results were as follows; 1. In the case of existence ability of tumor cell, IC50 had an anti-tumor ativity resulted 2.52mg/ml to SNU-C4. 0.41mg/ml to SNU-396, resulted to 0.09mg/mlSNU-1. 2. The groups of Jiaweicitaowan(加未慈桃丸) 10mg/ml, 20mg/kg had no body weight loss. reduction in intake of water and feed, so these had no toxicity. 3. In the case of the effect of extention of existence. the group of 20mg/kg Jiaweicitaowan(加未慈桃丸) extract treated group was showed 250% in ILS. 4. The effect of inhibition solid tumor was significantly decreased in both 10mg/kg, 20mg/kg of Jiaweicitaowan(加未慈桃丸) extract treated groups as compared with control group S. The groups of 10mg/kg, 20mg/kg Jiaweicitaowan(加未慈桃丸) had significant effect of body weight change compared to control group. 6. Delayed type hypersensitivity was not significant in both Jiaweicitaowan(加未慈桃丸) extract treated groups as compared with control group. 7. Hemagglutinin and Hemolysin titers were significantly increased by dose-dependent. so these results showed that the humoral immume respose was activated. 8. For the effect of rosette formimg cells was not significant in hoth Jiaweicitaowan(加未慈桃丸) extract treated groups as compared with control group. 9. Natural killer cell activity was significantly increased in both Jiaweicitaowan(加未慈桃丸) extract treated groups as compared with control group in the ratio of 100: 1, 50: 1 of effector and target cells, but in the ratio of 10:1, the Jiaweicitaowan(加未慈桃丸) extract treated groups were not significant. 10. The proliferation of lymphocyte and productivty of Interleukin-2 were significantly increased by dose-dependent in both 10mg/ kg, 20mg/ kg of Jiaweicitaowan(加未慈桃丸) extract treated groups as compared with control group. 11. In the phagocytic effect, the 20mg/kg of Jiaweicitaowan(加未慈桃丸) extract treated group showed the increasing effect with significance as compared with control group. According to the results, we can suggest that Jiaweicitaowan(加未慈桃丸) has the antitumor and the immunomodulatory effects.