• Journal of the Korean Ceramic Society
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• v.51 no.5
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• pp.472-476
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• 2014

In this work, a new method that utilizes L-cysteine salicylaldehyde Schiff-base modified macroporous polystyrene resin (PS-CSC) as an effective sorbent has been developed for preconcentration of trace cadmium and lead in environmental water samples. The effect of pH, the contact time, the elution conditions, the flow rate, the initial concentration of target metal ions, and the effects of interfering ions on the preconcentration of the analytes were investigated. The maximum adsorption capacity of PS-CSC under optimum conditions for cadmium and lead were found to be 6.03 - 18.17 mg/g and 12.58 - 36.13 mg/g when the initial concentration of metal ions between 5.0 - 90 mg/L. The limits of detection for cadmium and lead were 2.46 ng/L and $0.52{\mu}g/L$, with a preconcentration factor of 200. The developed method has been validated by analyzing certified reference material and successfully applied for the enrichment and determination of trace cadmium and lead from environmental water samples.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.111.1-111.1
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• 2010

석탄가스화복합발전(IGCC: Integrated Gasification Combined Cycle)의 고온 고압 합성가스로부터 $CO_2$를 저비용으로 포집하기 위한 연소전 포집 기술 중 유동층 촉진수성가스전환(SEWGS) 공정이 제안되어 연구개발 중에 있다. 연소전 $CO_2$ 포집을 위한 SEWGS 공정은 동일한 2탑 순환 유동층 반응기에서 고온 고압의 합성가스($H_2$, CO)를 유동층 WGS 촉매를 사용하여 CO를 $CO_2$로 전환하는 동시에 전환반응으로 생성된 $CO_2$를 흡수제를 이용하여 포집하는 기술이다. 본 연구는 $CO_2$ 회수와 WGS 반응이 동시에 이루어지는 공정에 적용 가능한 건식 재생 흡수제 및 유동층 WGS 촉매 개발을 목표로 $CO_2$ 흡수제(P Series) 및 WGS 촉매(PC Series) 조성을 제안하고 분무건조기를 이용하여 6~8kg/batch로 성형 제조하였다. 제조된 $CO_2$ 흡수제 및 촉매의 특성 평가 결과 내마모도(Attrition resistance)를 포함한 물리적 특성이 유동층 공정의 요구조건을 만족하는 결과를 얻을 수 있었다. 또한, 모사 석탄 합성가스를 이용하여 20bar, $200^{\circ}C$ 흡수/$400^{\circ}C$ 재생 조건에서 열중량 분석기(TGA) 및 가압 유동층(Fluidized-bed) 반응기를 통한 흡수제의 $CO_2$ 흡수능 평가를 수행하였다. 그 결과 내마모도(AI) 3% 이하로 기계적 강도가 우수하며, $CO_2$ 흡수능 17.6 wt%(TGA) 및 11wt%(가압 유동층)를 나타냈다. 유동층 WGS 특성 평가 결과 내마모도가 7~35%로 우수하였고, CO 전환율은 $200^{\circ}C$에서 80% 이상으로, 유동층 SEWGS 공정에 적용 가능한 특성을 확인하였다.

• Journal of the Korean Chemical Society
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• v.51 no.2
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• pp.141-146
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• 2007

The present paper describes a procedure for separation, preconcentration and determination of trace amount of copper in natural water samples by using 2-mercaptobenzimidazol as the complexing agent. The proposed method is based on the surfactant aggregation formed on γ-alumina by mixing sodium dodecyl sulfate and γ-alumina in water; 2-mercaptobenzimidazol was incorporated into inner hydrophobic part of produced ad-micelles in acidic media to produce an assemble suitable for preconcentration and determination of copper ion. Optimum experimental conditions for adsorption of μg/ml levels of copper ions from aqueous solution by the adsorbent have been reported. The copper ions were quantitively adsorbed by the sorbent over the pH range of 7.1-8.0 and were quantitatively desorbed afterward by using sulfosalycilic acid as the eluent. The determination of copper was not interfered in the presence of common metal ions. The procedure was applied for analysis of river water sample. Relative standard deviation was found to be 4.91%.

• Journal of the Korean Chemical Society
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• v.52 no.3
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• pp.239-248
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• 2008

study of the solid phase extraction (SPE) technique using activated carbon fiber (ACF) as a sorbent was carried out on the schedule chemicals in water. 14 different schedule chemicals, which are the hydrolysis products and simulants of chemical agents such as alkylphosphonate, thiodiglycol etc. were selected for the study. Pyridine was used as a promoter to increase the derivatization efficiency, especially to improve silylation of 3-quinuclidinol. To improve the recovery efficiency of amines in the water solution, 1 mL of 5% Et3N/MeOH was introduced into SPE-ACF before the water sample loading. Throughout this study, the optimum condition was established to detect rapidly above chemicals in water.

• Bulletin of the Korean Chemical Society
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• v.34 no.6
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• pp.1783-1790
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• 2013

A simultaneous analytical method has been developed for the fluorimetric determination of haloacetonitriles (HANs) [dichloroacetonitrile (DCAN), trichloroacetonitrile (TCAN), dibromoacetonitrile (DBAN), haloacetamides [dichloroacetamide (DCAD), and trichloroacetamde (TCAD)] in drinking water by using the combined on-line perconcentration/reversed phase liquid chromatography (RPLC)-postcolumn detection system. This on-line perconcentration system was achieved by employing a precolumn packed with a commercial solid phase extraction (SPE) sorbent for the enrichment and purification of the target analytes. The haloacetonitriles and haloacetamides were separated on CN analytical column in a 7.5% methanol-0.02 M phosphate buffered mobile phase at pH 3. The column effluents were reacted with postcolumn reagents of ophthaldialdehyde (OPA) and sulfite ion at pH 11.5, to produce a highly fluorescent isoindole fluorophore, which were measured with a fluorescence detector. Under the optimized conditions for RPLC and the postcolumn derivatization system all of the coefficient of determination of the standard calibration curves for the target analytes were over 0.99 and had a linear range from 5 to 100 ${\mu}g/L$. The detection limits showed 1.6 ${\mu}g/L$ for DCAD, 0.1 ${\mu}g/L$ for TCAD, 0.6 ${\mu}g/L$ for DCAN, 1.6 ${\mu}g/L$ for TCAN and 1 ${\mu}g/L$ for DBAN, and the recoveries were ranged from 64 to 99% except for DCAD with precisions less than 4.9% in distilled water, and from 72(${\pm}4%$) to 116%(${\pm}2%$) in tap water.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.6
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• pp.3851-3854
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• 2013

Objective: To explore changes in the serum tumor makers, hypoxia-inducible factor-$1{\alpha}$ (HIF-$1{\alpha}$) and vascular endothelial growth factor (VEGF) level and their relations in patients with non-small cell lung cancer (NSCLC) before and after intervention. Materials and Methods: Forty patients with NSCLC and 40 healthy individuals undergoing physical examination in our hospital provided the observation and control groups. HIF-$1{\alpha}$ and VEGF levels in serum were detected by enzyme-linked immuno-sorbent assay (ELISA) in the observation group before and after intervention and in control group on the day of physical examination, along with serum carcino-embryonic antigen (CEA), neuron-speci ic enolase (NSE) and squamous cell carcinoma antigen (SCC) levels in the observation group with a fully automatic biochemical analyzer. Clinical effects and improvement of life quality in the observation group were also evaluated. Results: The total effective rate and improvement of life quality after treatment in observation group were 30.0% and 32.5%, respectively. Serum HIF-$1{\alpha}$ and VEGF levels in the control group were lower than that in observation group (p<0.01), but remarkably elevatedafter intervention (p<0.01). In addition, serum CEA, NSE and SCC levels were apparently lowered by treatment (p<0.01). Serum HIF-$1{\alpha}$ demonstrated a positive relation with VEGF level (p<0.01) and was inversely related with CEA, NSE and SCC levels (p<0.01). Conclusions: Significant correlations exist between marked increase of serum HIF-$1{\alpha}$ and VEGF levels and decrease of indexes related to hematological tumor markers in NSCLC patients after intervention.

• Bulletin of the Korean Chemical Society
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• v.25 no.7
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• pp.969-976
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• 2004

Cassava peelings waste, which is both a waste and pollutant, was chemically modified using mercaptoacetic acid (MAA) and used to adsorb $Cu^{2+}\;and\;Cd^{2+}$ from aqueous solution over a wide range of reaction conditions at $30^{\circ}C$. Acid modification produced a larger surface area, which significantly enhanced the metal ion binding capacity of the biomass. An adsorption model based on the $Cu^{2+}/Cd^{2+}$ adsorption differences was developed to predict the competition of the two metal ions towards binding sites for a mixed metal ion system. The phytosorption process was examined in terms of Langmuir, Freundlich and Dubinin-Radushkevich models. The models indicate that the cassava waste biomass had a greater phytosorption capacity, higher affinity and greater sorption intensity for $Cu^{2+}\;than\;Cd^{2+}$. According to the evaluation using Langmuir equation, the monolayer binding capacity obtained was 127.3 mg/g $Cu^{2+}$ and 119.6 mg/g $Cd^{2+}$. The kinetic studies showed that the phytosorption rates could be described better by a pseudo-second order process and the rate coefficients was determined to be $2.04{\times}10^{-3}\;min^{-1}\;and\;1.98{\times}10^{-3}\;min^{-1}\;for\;Cu^{2+}\;and\;Cd^{2+}$ respectively. The results from these studies indicated that acid treated cassava waste biomass could be an efficient sorbent for the removal of toxic and valuable metals from industrial effluents.

• Journal of Energy Engineering
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• v.5 no.2
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• pp.123-130
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• 1996

Reduction, sulfidation, and regeneration reactions were performed using domestic and Australian iron ore in order to develop a desulfurizing sorbent for the high temperature desulfurization process that is one of major processes in the integrated coal gasification combined cycle (IGCC) system. A TGA (Thermogravimetric Analysis) reactor and a fixed-bed reactor were used. Some basic kinetic information was obtained from BET surface area measurements, SEM photos, cyclic reactions, reaction temperature changes and TGA curves of the sorbents. The rates of both desulfurization and regeneration increased with increasing reaction temperature in the range of 500-700$^{\circ}C$.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.4
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• pp.1129-1133
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• 2004

For the purpose of developing new anti-HIV agents from natural sources, the extracts of Kalopanax pictus were tested for their inhibitory effects on HIV-1 replication and its essential enzymes as the reverse transcriptase (RT). protease and α-glucosidase. In the assay of HIV-1-infected human T-cell line, water extracts of stem and leafstalk inhibited the HIV-1-induced cytopathic effects with Ie (inhibitory concentration) of 25 and 50㎍/㎖, respectively. Moreover water extracts (100㎍/㎖) of stem and leafstalk showed strong activity of 80% and 90% on anti-HIV-1 RT using Enzyme Linked Oligonucleotide Sorbent Assay (ELOSA) method. In the HIV-1 protease inhibition assay, aqueous stem extract inhibited the activity of the enzyme to cleave an oligopeptide, resembling one of the cleavage sites in the viral polyprotein which can only be processed by HIV-1 protease with 58%, but no glucosidase inhibitory activities. We found out this result, for these samples it is possible that the inhibition of the viral replication in vitro is due to the inhibition at least one of RT and protease. It would be of great interest to identify the compounds which are responsible for this inhibition, since all therapeutically useful agent up to date are RT, PR and α-glucosidase inhibitors.

• Journal of environmental and Sanitary engineering
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• v.22 no.4
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• pp.11-21
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• 2007

The recent investigation indicates that the kinetic constants for anionic ions were merely the result of ion exchange between the algae cell wall surface and the anionic ion. In this study, Zygnema sterile and Lepocinclism textra, floating flagellate alga as the dominant algae strains, were cultivated using HRABR(High Rate Algae Biomass Reactor) and the cultivation conditions were 24 hrs. and 12 hrs. irradiation and it was studied how this algal biomass acts on the biosorption mechanism of anionic N and P. Results are as follows : 1. Calculating the specific chl.-a growth rate using Michaelis-Menten model, the one of 24hrs. irradiation was about 55 times higher than the one of 12 hrs. irradiation 2. Calculating the specific chl.-a growth rate using Kuo model, the one of 24 hrs. irradiation was about 2.26 times higher than the one of 12 hrs. irradiation 3. Langmuir model can apply to the biosorption mechanism of anionic N and P in HRABP. 4. Regarding the chlorophyll-a concentration as unit weight of sorbent, the ion selectivity coefficients for N and P are as follows : $(NH_3-N)+(NO_3-N)$ in 24 hrs. irradiation ; 44.984 $PO_4-P$ in 24 hrs. irradiation ; 24.237 $(NH_3-N)+(NO_3-N)$ in 12 hrs. irradiation ; 1432.851 $PO_4-P$ in 12 hrs. irradiation ; 599.076