• Journal of Korea Soil Environment Society
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• v.3 no.2
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• pp.89-99
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• 1998

Sorption of the aqueous cyanide onto steel mill sludge and steel mill slag, both of which are the by-products from the converter furnace, was studied. In the study, the influence of temperature, activation energy, concentration and pH on sorption of cyanide was investigated. Three different temperature($25^{\circ}C$ > $37^{\circ}C$> $50^{\circ}C$) was chosen to represent that of landfill leachate. Initial concentration was 1 mg/$\ell$ 5 mg/$\ell$, 10 mg/$\ell$, and 20 mg/$\ell$. In addition, pH was set to three different level, that is, 3, 7, and 11 respectively. As the result of batch mode experiment for cyanide adsorption, the removal rate was found to be proportional to the initial concentration of cyanide. The order of removal rate was 20 mg/$\ell$> 10 mg/$\ell$> 5 mg/$\ell$> 1 mg/$\ell$. Similarly the influence of pH was proportional because of the change in solubility of cyanide. The order of removal rate was pH 11 > pH 7 > pH 3. As the temperature increased, so did the removal rate. The reaction was endothermic and the value of activation energy(Ea) was 127.93 J/mole and 59.44 J/mole respectively at 1 mg/ιand 20 mg/ιof initial concentration. From the experiment, it can be postulated that the capability of steel mill by-products to attenuate aqueous cyanide is enough to be used as substitute for clay liner of landfill site in the aspect of pollutant removal.

• Journal of Naturopathy
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• v.12 no.1
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• pp.7-15
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• 2023

Background: As a result of analyzing the components of wild Conyza canadensis, it contains physiologically active ingredients, so it is necessary to identify the compound. Purposes: It was to study the compound's molecular structure; a previous study showed that C. canadensis contains antioxidant substances. Methods: The ultrasonic pulverized lysate of C. canadensis stem and leaves was first extracted with 90% methanol and then five organic solvents. Next, the extracts was fractionated by HPLC, LC/MS chromatography, and NMR analyzers identified the molecular structure. Results: 100 g of dry C. canadensis was sonicated in 90% methanol and concentrated under reduced pressure to 11.96 g of a crude extract. Then, this crude was extracted with five types of solvents to obtain 123.8 mg of n-hexane, 448.2 mg of dichloromethane, 1047.7 mg of ethyl acetate (EA), 2563.8 mg of butanol, and 7.04 g of water. The EA extracts were fractionated by LC-MS and then re-fractionated to obtain F1 to F20. Next, the F15 was further fractionated to obtain nine fine fractions. Finally, the F17 fraction was re-fractionated to obtain ten fine fractions. As a result of LC-MS and NMR spectrometer analysis of the F15-7, the structure of this compound was confirmed as 3,5-dicaffeoylquinic acid. As a result of examining the structures of the F17-4 and F17-5 fractions, Quercetin-3-o-β-galactose was identified. In addition, the form of the F17-10 was confirmed to be 1,3,4-tri-caffeoylquinic acid. Conclusions: This study demonstrated that C. canadensis contained phenolic antioxidants, and its utilization may be expected.

• Microbiology and Biotechnology Letters
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• v.41 no.2
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• pp.228-235
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• 2013

Radish (Raphanus sativus) is a common cruciferous vegetable, and its aerial parts, called Mu-chung in Korean, have plentiful nutritional components such as vitamins, minerals and dietary fibers. Mu-chung has been used as a kimchi, a traditional Korean fermented dish, and dried Mu-chung is an important component of soups commonly consumed during winter in Korea. Since the advent of the mass production of radish in Korea, with the segregation of farm areas and towns and changing diets, Mu-chung has mostly been discarded instead of utilized. In addition, studies concerning the efficient utilization and useful bioactivities of Mu-chung are still lacking worldwide. In this study, we prepared the ethanol extract of Mu-chung and its subsequent solvent fractions. Antimicrobial, antioxidation, and anticoagulation activities were then evaluated in the hopes of developing a functional biomaterial from Korean radishes' aerial parts. The ethanol extraction yield for hot-air dried Mu-chung was 5.6%, and the fraction yields of n-hexane (H), ethylacetate (EA), butanol (B) and water residue were 25.3, 3.6, 19.4, and 51.7%, respectively. Analysis of total polyphenol and total flavonoid contents showed that the EA fraction had the highest content (97.57 and 152.91 mg/g) amongst the fractions. In antimicrobial activity assays, the H and EA fractions were effective against gram positive bacteria (Staphylococcus aureus, Listeria monocytogenes, and Bacillus subtilis), but not effective against gram negative bacteria (Escherichia coli and Pseudomonas aeruginosa). The B fraction also exhibited moderate antibacterial activity, suggesting that the extract of Mu-chung has various antibacterial components. In antioxidation activity assays, the EA fraction showed strong DPPH, ABTS and nitrite scavenging activities ($69-222{\mu}g/ml$ of $IC_{50}$), including reducing power. In anticoagulation activity assays, the EA fraction demonstrated strong inhibition activity against human thrombin and prothrombin. Prominent anticoagulation activity was found in aPTT assays; the aPTT of the EA fraction was extended 15-fold compared than that of the solvent control. Our results suggest that Mu-chung is an attractive nutritional food material possessing useful bioactivities, and the EA fraction of Mu-chung could be developed as a functional food ingredient.

• Proceedings of the Korea Database Society Conference
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• 2002.10a
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• pp.197-211
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• 2002

본 연구에서는 정보기술 표준의 활용과 그에 따른 정보시스템의 상호운용성 수준과의 관계를 알아봄으로써 정보기술 아키텍처(ITA)에서 강조하고 있는 정보기술 표준의 활용 수준이 높으면 정보시스템의 상호운용성 수준도 높을 것인지를 실증적으로 알아보고자 하였다. 또한 정보기술 표준의 활용에 대한 측정을 위해 정보기술 아키텍처의 3가지 요소(EA, TRM, S/P) 중 하나인 기술참조모델(한국전산원의 TRM)의 표준서비스 분류를 선택하였고, 정보시스템의 상호운용성 수준을 측정하기 위해서는 정보시스템 상호운용성 수준(LISI : Levels of Information System Interoperability) 모델에 따름으로써 정보기술 아키텍처적 관점에서 접근하였다. 설문지를 통한 실증연구 결과, 다양한 표준서비스 중에서 보안서비스, 플랫폼서비스 및 데이터교환서비스 표준만이 실제 정보시스템 상호운용성에 영향을 미치는 것으로 나타났다.

• The Journal of Information Systems
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• v.30 no.3
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• pp.93-112
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• 2021

Purpose Recently, many organizations are actively adopting enterprise architecture (EA) as a methodology to manage IT assets and build IT-based business system. This study intended to empirically examine how the role of EA operating unit and utilization capability of organizational members impact on system performance at the post-adoption stage. A balanced score card (BSC) is being used as a framework for a company's key performance indicator (KPI). Design/methodology/approach This study tried to investigate the causal relationship between the four perspectives of the balanced scorecard as an influencing factor of the introduction of the Enterprise Resource Planning (ERP) on the financial value. In particular, the mediating effect between the customer's point of view and the business process point of view was investigated between the learning growth point of view and the financial point of view, and the interaction effect (regulating effect) of strategic linkage in the system introduction process was investigated. Findings The results of the study were first, that the organizational learning and growth perspective had a positive effect on the customer perspective, business process, and financial perspective. In addition, the customer perspective and the process perspective also had a positive influence on the financial perspective. Second, between the learning growth and financial perspectives, the customer perspective and the process perspective showed a partial mediating effect. Third, as for strategic linkage, the interaction effect between the customer perspective, the learning growth perspective, and the process perspective and the financial perspective was not significant. The results of this study are expected to provide a framework for performance evaluation to organizations that have introduced ERP systems.

• Journal of Energy Engineering
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• v.8 no.4
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• pp.592-604
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• 1999

The steady state and dynamic characteristics of large cell area MCFC stacks were analyzed to solve the problems such as temperature difference generated in stacks and pressure difference between anode and cathode. Manipulated variables (current density, duel utilization rate, oxidant utilization rate) and controlled variables (temperature difference, anode and cathode pressure difference) which had an important effect on the MCFC stack performance were determined using operation results of two types of MCFC stacks (5kW (3,000 $\textrm{cm}^2$, 20 ea). 3kW (6,000 $\textrm{cm}^2$, 5ea)). The stability and transfer function representing system dynamics were obtained by steady state gain rate which showed the relative change between MVs and CVs. The transfer function was a 3$\times$3 matrix and a typical first order system without time delay. The optimal operating condition of large cell area MCFC stacks could be determined by analyzing dynamic characteristics. In case of a 5 kW MCFC stack, pressurized operation with recycle flow should be used to control the outlet temperature less than 68$0^{\circ}C$ and to control the MCFC system effectively. MIMO control or decoupler should be used to remove the interaction between MVs and CVs. This result will be used as important data in determining the control structure design and operation mode of large cell area MCFC systems in the future.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.251.2-251.2
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• 2010

Plant biomass has been proposed to be an alternative source for petroleum-based chemical compounds. Especially, phenolic chemical compounds can be obtained from lignin by chemical depolymerization processes because lignin consists of complex aromatic polymer such as trans-p-coumaryl, coniferyl and sinapyl alcohols, etc. Phenolic chemical compounds from lignin were usually produced in super critical water. However, we applied Near-critical water (NCW) system because NCW is known as a good solvent for lignin depolymerization. Organic matter like lignin can be solved in NCW system and the system has a unique acid-base property without conventional non-eco-friendly chemicals such as sulfuric acid and sodium hydroxide. In this work, we tried to optimize the NCW depolymerization system by adjusting the processing variables such as reaction time, temperature and pressure. Moreover, the amount of additional phenol was optimized by changing the molar ratio between water and phenol. Phenol was used as capping agent to prevent re-polymerization of active fragment such as formaldehyde. Alkali-lignin was used as a starting material and characterized by a Solid State 13C-NMR, FT-IR and EA (Elemental Analysis). GC-MS analysis confirmed that o-cresol, p-cresol, anisole and 4-hydroxyphathalic acid were the main product and they were quantitatively analyzed by HPLC.

• Bulletin of the Korean Chemical Society
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• v.33 no.8
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• pp.2546-2552
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• 2012

A novel biguanide-functionalized $Fe_3O_4/SiO_2$ magnetite nanoparticle with a core-shell structure was developed for utilization as a heterogeneous organosuperbase in chemical transformations. The structural, surface, and magnetic characteristics of the nanosized catalyst were investigated by various techniques such as transmission electron microscopy (TEM), powder X-ray diffraction (XRD), vibrating sample magnetometry (VSM), elemental analyzer (EA), thermogravimetric analysis (TGA), $N_2$ adsorption-desorption (BET and BJH) and FT-IR. The biguanide-functionalized $Fe_3O_4/SiO_2$ nanoparticles showed a superpara-magnetic property with a saturation magnetization value of 46.7 emu/g, indicating great potential for application in magnetically separation technologies. In application point of view, the prepared catalyst was found to act as an efficient recoverable nanocatalyst in nitroaldol and domino Knoevenagel condensation/Michael addition/cyclization reactions in aqueous media under mild condition. Additionally, the catalyst was reused six times without significant degradation in catalytic activity and performance.

• Journal of Information Technology and Architecture
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• v.11 no.1
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• pp.1-10
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• 2014

From 2004 to 2013, the annual investment for the ICT sector in Korea amounted to about 3.2 trillion won. Depending on whether the government policy allowed for budget increases and/or decreases, this impacted the investment in the ICT sector. In particular, the fixed costs of operation and maintenance lead to a reduced chance for a new potential demands in IT programs. Even though a situation may exist that there are insufficient funds available, there is a need for building a sustainable long-term IT investment management system. The purpose of this study is to conduct basic research for the arrangement of preparation to meet IT needs required in the public sector. For this, this paper introduces the concept of IT Investment Management based on prudent forecasting. After both foreign and domestic relevant cases are reviewed, implications will be derived from the aforementioned cases. Through this process, the direction of IT Investment Management based on forecasting for the IT projects decision making will be suggested. These research results could be used for helping to develop better policies and a more efficient management of the public sector IT budget.

• International Area Studies Review
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• v.15 no.3
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• pp.29-53
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• 2011

This paper studies the contribution of imports and inward foreign direct investment (FDI) as a vehicle of technology transfer onto the EU new member states at both macroeconomic and industry level. The paper takes the effectiveness of the recipient's utilization into account by constructing a new index, the so-called Effective Absorption (EA) Index, to measure ability to absorb and utilize the foreign technology in the recipient country. Using data from 12 donors and 10 recipients from 1998 to 2009, the study at macroeconomic level indicates that technical spillovers of foreign research and development (R&D) play more crucial role relatively to domestic R&D on total factor productivity (TFP) growth of the new member states. Imports are found as the major vehicle of technical spillovers rather than inward FDI. The study at industry level is conducted by using data from 17 manufacturing industries of 10 donors and 6 recipients during 1998 to 2009. The empirical results also support the findings at country level. The patterns of technology transfer are different across industries. Nonetheless, technical spillovers exhibit significantly high contribution on TFP growth in high-tech manufacturing industries.