• The Journal of the Petrological Society of Korea
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• v.25 no.2
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• pp.107-119
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• 2016

Trace element abundances in the igneous rocks are important data for petrogenetic interpretation. Their concentrations are generally measured using ICP-MS from the dissolved solution. The acid digestion of rock powder can be performed by conventional teflon vial or pressure bomb. In this paper, we investigated a problem that happened during acid digestion experiment using conventional teflon vial or pressure bomb of BCR2 and GSP2 USGS rock standard materials. The results show that the measured concentrations of the elements like Cr, Ni, Zn, Ta, W in the BCR2 are different from the recommended values of USGS whereas those of the elements like Rb, Sr, Zr, Hf, Ta, W in the GSP2 are different from those values. Our experiment shows that defect of specific elements like Cr, Ni may happen during the sample digestion. Our results also indicate that the Cr, Ni, W, Zr, Hf, Ta concentration obtained based on an acid digestion of geological samples need to be careful in their geochemical interpretation.

• Korean Chemical Engineering Research
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• v.45 no.3
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• pp.269-276
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• 2007

$TiO_2$-containing pitch fibers were prepared and various stabilization variables were investigated by characterizations of the fibers and behaviors of $TiO_2$ particles in the optimum stabilization conditions. When pitch fiber was stabilized by air at the optimum condition, the fiber weight increased as an increase of the stabilization temperature and a decrease of $TiO_2$ concentration. The carbonization yield was 71~82 wt.%, showing a decrease of the yield with the $TiO_2$ increase caused by the catalytic activity of $TiO_2$ to combustion. During the stabilization, newly developed carbonyl and carboxyl groups were introduced on the fiber surface and cross-linking reactions were progressed resulting the thermosetting property, which was verified by the replacement of hydrogen with oxygen. Pore size of the activated carbon fiber was increased by an increase in $TiO_2$ concentration. In the considerations of the aggregation behaviors of the $TiO_2$ particles, the optimum stabilization conditions of 0.5 wt.% $TiO_2$ containing petroleum-based pitch fiber were suggested as $280^{\circ}C$, 3 hr.

• Polymer(Korea)
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• v.33 no.1
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• pp.58-66
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• 2009

The thermotropic liquid crystalline behavior of the homologous series of cellulose tri[4-{4'-(nitrophenylazo) phenoxycarbonyl}] alkanoates (NACEn, n=2$\sim$8, 10, the number of methylene units in the spacer) have been investigated. All of the homologoues formed monotropic nematic phases. The isotropic-nematic transition temperature ($T_{iN}$) decreased when n is increased up to 7, but it became almost constant when n is more than 7. The plot of transition entropy at $T_{iN}$ against n had a sharp negative inflection at n=7. The sharp change at n=7 may be attributed to the difference in arrangement of the side groups. The melting temperature ($T_m$) and associated entropy change at $T_m$, in contrast with $T_{iN}$ and associated entropy change at $T_{iN}$, exhibited a distinct odd-even effect, suggesting that the average shape of the side chains in the crystalline phase is different from that in the nematic phase. The thermal stability and degree of order of the nematic phase observed for NACEn were significantly different from those reported for the homologous series of side-chain and combined type liquid crystal polymers bearing azobenzene or biphenyl units in the side chains. The results were discussed in terms of the differences in the chemical structure, the flexibility of the main chain, the mode of chemical linkage of the side group with the main chain, and the number of the mesogenic units per repeating unit.

• THE JOURNAL OF KOREAN ORIENTAL ONCOLOGY
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• v.4 no.1
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• pp.37-53
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• 1998

The sprig of Jinryungtang Gagambang has been used for curing as a traditional medicine without any experimental evidence to support the rational basis for their clinical use. This experiment was carried out to evaluate the possible therapeutic or antitumoral effects of Jinryungtang Gagambang extract against cancer, and to study some mechanisms responsible for its effect. The cytotoxic and antitumor effects were evaluated on human cell liens (A549, hep3B, Caki-1, Sarcoma 180) after exposure to Jinryungtang Gagambang extract using in ILS, colony forming efficency and SRB assay which were regarded as a valuable method for cytotoxic and antitumor effects of unknown compound on tumor cell lines. The results obtained in this studies were as follows. 1. As a result of exposure to Jinryungtang Gagambang extract, the proliferation of A549, hep3B, Caki-1, good correlations were shown from the results of SRB assay and those of clogenetic assay. 2. The oral administration of Jinryungtang Gagambang extract showed significant effects of increase of MST(mean survival time) and ILS(increased life span) depending on the increasing concentration. 3. Against squamous cell carcinoma induced by MCA, Jinryungtang Gagambang decreased not only the frequency of tumor production but also the number and weight of tumors per tumor bearing mice(TBM). Jinryungtang Gagambang also significantly suppressed the development of 3LL cell-implanted tumors by frequency and their size, and some developed tumors were regressed by the continuous treatment of Jinryungtang Gagambang extract into TBM. 4. Jinryungtang Gagambang extract also increased NK cell activities. According to the above results, it could be suggested that Jinryungtang Gagambang extract has prominent antiutmor effect.

• Journal of Wetlands Research
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• v.25 no.2
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• pp.145-158
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• 2023

Constructed wetlands (CWs) are effective technologies for urban wastewater management, utilizing natural physico-chemical and biological processes to remove pollutants. This study employed a bibliometric analysis approach to investigate the progress and future research trends in the field of CWs. A comprehensive review of 100 most-recently published and open-access articles was performed to analyze the performance of CWs in treating wastewater. Spain, China, Italy, and the United States were among the most productive countries in terms of the number of published papers. The most frequently used keywords in publications include water quality (n=19), phytoremediation (n=13), stormwater (n=11), and phosphorus (n=11), suggesting that the efficiency of CWs in improving water quality and removal of nutrients were widely investigated. Among the different types of CWs reviewed, hybrid CWs exhibited the highest removal efficiencies for BOD (88.67%) and TSS (95.67%), whereas VSSF, and HSSF systems also showed high TSS removal efficiencies (83.25%, and 78.83% respectively). VSSF wetland displayed the highest COD removal efficiency (71.82%). Generally, physical processes (e.g., sedimentation, filtration, adsorption) and biological mechanisms (i.e., biodegradation) contributed to the high removal efficiency of TSS, BOD, and COD in CW systems. The hybrid CW system demonstrated highest TN removal efficiency (60.78%) by integrating multiple treatment processes, including aerobic and anaerobic conditions, various vegetation types, and different media configurations, which enhanced microbial activity and allowed for comprehensive nitrogen compound removal. The FWS system showed the highest TP removal efficiency (54.50%) due to combined process of settling sediment-bound phosphorus and plant uptake. Phragmites, Cyperus, Iris, and Typha were commonly used in CWs due to their superior phytoremediation capabilities. The study emphasized the potential of CWs as sustainable alternatives for wastewater management, particularly in urban areas.

• Proceedings of the Korean Aquaculture Society Conference
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• 2003.10a
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• pp.80-81
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• 2003

양식 생물의 질병 제어는 예방과 치료를 통해 이루어진다. 그러나 항생제의 오ㆍ남용으로 인하여 약제 내성균의 증가와 치료 효과가 감소하고, 나아가 식품안전성 문제로 양식생물의 소비를 위축시켜왔다. 따라서 질병이 발생한 후에 시행하는 화학약품 치료법은 이미 한계에 달하였다. 이에 따라 사전에 질병을 차단하는 예방법인 vaccine이나 질병에 대한 저항능력을 키우는 비특이적 면역 증강물질에 대한 관심이 꾸준히 높아지고 있다. 해조류에는 다량의 lectin이 포함되어 있는데, Lectin은 당에 결합하는 단백질의 총체적인 이름으로, defence molecule로 작용하여 어류가 섭취할 경우 외래 항원으로 인식하여 지속적으로 면역 기능을 활성화시키는 것으로 알려져 있다. 따라서 본 연구는 돌돔사료에 kelf meal을 첨가하여 공급한 후 이들의 성장과 비특이적 면역기구에 미치는 효과를 조사하였다. 실험사료는 상업용 kelf meal을 0%, 2%, 5% 첨가하고, 2반복으로 500L FRP 탱크에서 8주간 사육하였다. 실험어류는 40g 내외의 돌돔을 대상으로 하였고, 사료공급 4주 및 8주에 각 실험구의 돌돔을 대상으로 비특이적 면역기구에 미치는 효과를 조사하였다. 체액성 면역 조사로는 혈청 및 점액 lysozyme 활성과 Escherichia coli에 대한 혈청 내 보체의 살균 능력을 조사하였고, 세포성 면역 조사는 전신 식세포의 NBT 환원 실험과 말초혈액의 식세포 식균능을 측정하였다. 식균능 시험은 Escherichia coli FKC (formalin killed cell)에 대한 식균율 및 식균지수로 나타내었다. 나아가 돌돔 말초혈액의 혈구조성에 미치는 영향을 조사하기 위하여 적혈구 5,000 세포당 임파구, 전구, 호중구의 수를 계수하였다. 8주간의 사육결과 사료계수는 각각 1.20, 1.25, 1.42로 대조구와 2% 첨가구는 큰 차이가 없었으나, 5% 첨가구는 나빠지는 경향을 보였다. 사료섭취량은 kelf meal의 첨가량이 늘어나면서 감소하는 경향이었다. 비특이적인 면역 기구에 대한 자극 효과는 체액성 면역의 지표로 측정한 lysozyme의 활성도는 혈청과 점액 모두에서 대조구보다 실험구에서 활성이 높았고, 혈청 lysozyme 활성은 5% 첨가구에서 가장 높았다. 혈청 내 보체의 살균능은 실험구간 차이가 없었다. 세포성 면역의 지표로 측정한 전신 식세포의 $O_2$ 생성능(NBT 환원능)은 5% 첨가구에서 가장 높았다. 말초 혈액의 식균능은 식균율과 식균지수 모두 실험구에서 높았고, 특히 5% 첨가구에서 가장 높았다. 말초 혈액 혈구조성의 변화는 임파구와 전구의 경우 실험구에서 높았으나 호중구에서는 차이가 없었다. 이상의 결과, 양식 돌돔에 kelf meal을 2% 첨가하는 것이 사료계수에 큰 영향을 미치지 않고, 돌돔의 체액성 및 세포성 면역을 적절히 자극하는 것으로 나타나, 돌돔의 기능성 사료 첨가물로서 이용 효과가 있을 것으로 기대된다.

• Journal of the Korean Electrochemical Society
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• v.17 no.1
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• pp.30-36
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• 2014

Redox complexes to transport electrons from enzyme to electrodes are very important part in glucose sensor. Pentacyanoferrate-bound aniline ($Fe(CN)_5$-aminopyridine), was prepared as a potential redox mediator in a glucose dehydrogenase (GDH)-glucose sensor. The synthesized pyridyl-$NH_2$ to pentacyanoferrate was characterized by the electrochemical and spectroscopic methods. A amperometric enzyme-linked electrode was developed based on GDH, which catalyses the oxidation of glucose. Glucose was detected using GDH that was co-immobilized with an $Fe(CN)_5$-aminopyridine and gold nano-particles (AuNPs) on ITO electrodes. The $Fe(CN)_5$-aminopyridine and AuNPs immobilized onto ITO electrodes provided about a two times higher electrochemical response compared to that of a bare ITO electrode. As glucose was catalyzed by wired GDH, the electrical signal was monitored at 0.4 V versus Ag/AgCl by cyclic voltammetry. The anode currents was linearly increased in proportion to the glucose concentration over the 0~10 mM range.

• Korean Journal of Agricultural and Forest Meteorology
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• v.11 no.1
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• pp.27-38
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• 2009

The multi-level profile system is designed to measure the vertical profile of $H_2O$ and $CO_2$ concentrations in the surface layer to estimate the storage effects within the plant canopy. It is suitable for long-term experiments and can be used also in advection studies for estimating the spatial variability and vertical gradients in concentration. It enables the user to calculate vertical fluxes of water vapor, $CO_2$ and other trace gases using the surface layer similarity theory and to infer their sources or sinks. The profile system described in this report includes the following components: sampling system, calibration and flow control system, closed path infrared gas analyzer(IRGA), vacuum pump and a datalogger. The sampling system draws air from 8 inlets into the IRGA in a sequence, so that for 80 seconds air from all levels is measured. The calibration system, controlled by the datalogger, compensates for any deviations in the calibration of the IRGA by using gas sources with known concentrations. The datalogger switches the corresponding valves, measures the linearized voltages from the IRGA, calculates the concentrations for each monitoring level, performs statistical analysis and stores the final data. All critical components are mounted in an environmental enclosure and can operate with little maintenance over long periods of time. This report, as a practical manual, is designed to provide helpful information for those who are interested in using profile system to measure evapotranspiration and net ecosystem exchanges in complex terrain.

• Applied Chemistry for Engineering
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• v.10 no.1
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• pp.154-159
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• 1999

EDTA (ethylenediaminetetraacetic acid), a chelating agent is most widely used in industrial applications, especially for cleaning of metals in water, frequently prohibits metal removal from water in conventional water treatment technologies. It could be easier to remove aqueous metal ions by the breakdown of DETA complexed bonds first. This study investigated the availability of $TiO_2$ photo-catalysis for the aqueous phase oxidation of Cu(II)-EDTA, under an aerobic condition at $20^{\circ}C$ with $TiO_2$ (Degussa P-25) and 1.79mM of Cu(II)-EDTA. When $TiO_2$ loading was 2.0 g/L, the photo-catalytic oxidation of Cu(II)-EDTA was maximal. The tendency of EDTA adsorption onto the catalyst surface was affected by $TiO_2$ surface charge, and the oxidation rate of Cu(II)-EDTA by photo-catalysis was shown to be dependent upon the tendency of EDTA adsorption before photo-irradiation.

• The Journal of Engineering Geology
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• v.27 no.3
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• pp.293-304
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• 2017

This study was performed in order to hydrogeological analysis of aquifer, which is a necessary part for evaluating the efficiency of the combined well and open-closed loops geothermal (CWG) systems. CWG systems have been proposed for the effective utilization of geothermal energy by combining open loop geothermal systems and closed loop geothermal systems. Small aperture CWG systems and large aperture CWG systems were installed at a green house land with water curtain facilities in Chungju City. Aquifer tests include pumping tests and step-drawdown tests were conducted to analyse hydrogeological characteristics of aquifer in the study area. The transmissivity was estimated in the range of $13.49{\sim}58.99cm^2/sec$, and the storativity was estimated in the range of $1.13{\times}10^{-5}{\sim}5.20{\times}10^{-3}$. The geochemical analysis showed $Ca^{2+}$ ion and ${HCO_3}^-$ ion were dominant in groundwater. The Langelier Saturation Index and the Ryznar Stability Index showed low scaling potential of groundwater. In the analysis of vertical water temperature change, the geothermal gradient was estimated as $2.1^{\circ}C/100m$, which indicated the aquifer was enough for geothermal systems. In conclusion, groundwater is rich, can stably use geothermal heat, and it is less likely to cause deterioration of thermal energy efficiency by precipitation of carbonate minerals in study area. Therefore, the study area is suitable for installation of the combined geothermal system.