• 한국주조공학회지
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• 제15권5호
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• pp.507-513
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• 1995

The effect of forced convention on the solute redistribution of the Al ingot was studied quantitatively in an effort to fabricate high purity aluminum using a segregation method. Based on the experimental results, the solute concentration in the solid phase tended to decrease at the early state of solidification, and then increased gradually as solidification proceeded. Fe and Si concentrations decreased as growth rate decreased and as revolution speed increased. The solute redistribution obtained from the BPS model incorporated with the tangential flow component as well as the axial flow component within the melt, agreed well with the measurements.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 B
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• pp.675-678
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• 1997

In this paper, we present a fast and robust algorithm for the design of fuzzy controller and identifying fuzzy model from numerical data by combining the cluster estimation method with a linear least squares estimation procedure. The proposed method is compared with Adaptive Neuro-Fuzzy Inference System(ANFIS) as the standard example of neuro-fuzzy model. Finally we will show its usefulness and effectiveness for the design of fuzzy controller of a cart-pole system and fuzzy modeling for the coagulant dosing of a water purification system.

• 약학회지
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• 제32권6호
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• pp.415-419
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• 1988

A rapid and simple method for the determination of pentoxifylline and its major metabolite, metabolte(I) in plasma was examined by HPLC. For the purification and enrichment of drug from plasma, solid-phase extraction was examined using Sep-pak C18 cartridge. The effectiveness of test method was proved by monitoring of the rat after oral administration of pentoxifylline in a dose of 40mg/kg.

• 대한화학회지
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• 제52권1호
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• pp.52-56
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• 2008

제법을 위한 쉽고 효과적인 이 방법은 solvent-free하에서 H3PMo12O40 촉매를 사용해서 개선되었다. 이 방법의 큰 이점은 조작의 간편성, 더 작은 촉매량, 선택성, 온화한 반응조건,짧은 반응 시간 그리고 높은 수율이다. 재생된 촉매는 어떤 정제도 없이 다시 사용되어질 수 있다.

• 청정기술
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• 제24권1호
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• pp.15-20
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• 2018

Hexafluoropropyleneoxide ($C_3F_6O$, HFPO) is highly expensive and it may be used as a raw material for the synthesis of various fluorine based compounds. Currently, extractive distillation method has gained considerable attention to collect the HFPO from a mixture of HFPO / hexafluoropropylene ($C_3F_6$, HFP). Optimized operating conditions are studied using a theoretical method for the extraction process. Among available solvents for the purification process, the use of 1,1-dichloro-1-fluoroethane exhibits a high purity of HFPO as a top product and minimize the required heat duty. Since the boiling point of the solvent increases as the pressure in the column increases, the enhanced extractive capability of the solvent led to the high purity of HFPO at the high pressure.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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• pp.813-816
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• 2006

Recently, improvements in the standard of living in industrial area require the establishment of a convenient residential environment in order to enhance the quality of living. To achieve such an environment, it is necessary to effectively reduce or prevent various environmental problems occurring in and around residential areas. Although conventional concrete has been regarded as a destroyer of nature, water and air can pass freely through concrete when it is made porous concrete by forming continuous void. In view of the harmony between nature and concrete, various research paths are being taken focusing on coarse aggregates to make porous concrete having continuous voids so as to improve water and air permeability, acoustic absorption, water purification, and applicability to vegetation. In this study, the Physical and Mechanical Properties of porous concrete according to compaction method analyzed by void ratio, coefficient of permeability and compressive strength.

• 생명과학회지
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• 제7권3호
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• pp.186-191
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• 1997

수정된 선별법(modified selection method)을 사용하여 candiosis에 대한 새로운 생리활성물질(anticandiosis agent)을 생성하는 미생물을 분리하여Streptomyces sp. S627이라 명명하였으며, 이균의 발효액으로부터 methanol추출, diaion Hp-20, silica gel chromatography, 및 분취용 TLC 등의 방법을 사용하여 물리화학적 특성이 다른 S-637(A)와 S-627(B)을 분리하였다.

• 한국식품저장유통학회지
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• 제4권1호
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• pp.45-51
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• 1997

In our studies on the role of $\beta$-galactosidase in fruit softening, significant difficulty, was encountered in our attempts to extract RNA from persimmon(Diospyros kaki L. cv. Fuyu) fruit due to astringency and tannin content. Initial, unsuccessful RNA extractions involved methods using guanidinium isothiocyanate/CsCl with and without polyvinylpyrrolidone(PVP), phenol/sodium lauryl sulfate(SDS), guanidinium hydrochloride, as well as polysomal RNA purification method that used 0.2 M Tris-HCI (pH 9.0) containing KCI, Mg-acetate, EDTA, $\beta$-mercaptoethanol, and sucrose. A method was devised which employed treatment of fruit with CO2 gas to diminish astringency prior to RNA extraction, followed by extraction of tissue powders with Proteinase K extraction buffer containing PVP and ascorbate at an alkaline pH. This procedure resulted in the removal of tannins and other polyphenolics and extraction of relatively large amount of high-quality RNA suitable for cDNA library construction and polymerase chain reaction(PCR). Futhermore, the procedure does not use the toxic and corrosive chemical guanidinium isothiocyanate or require ultracentrifugation.

• Advances in environmental research
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• 제2권1호
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• pp.1-8
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• 2013

There is a significant demand to make various dissolved gases in water. However, the conventional aeration method shows low gas mass transfer rate and gas utilization efficiency. In this study, a novel rotating wheel entraining gas method was developed for making high dissolved $O_2$ and $O_3$ in water. It produced higher concentration and higher transfer rate of dissolved $O_2$ and $O_3$ than conventional bubble aeration method, especially almost 100% of gas transfer efficiency was achieved for $O_3$ in enclosed reactor. For application of rotating wheel entraining gas method, aerobic bio-reactor and membrane bio-reactor (MBR) were successfully used for treatment of domestic and pharmaceutical wastewater, respectively; and vacuum ultraviolet $(VUV)/UV+O_3/O_2$ reactors were well used for sterilization in air/water, removal of dust particles and toxic gases in air, and degradation of pesticide residue and sterilization on fruits and vegetables.

• Advances in nano research
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• 제14권1호
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• pp.103-115
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• 2023

Recent developments in the synthesis of nanomagnesia of controlled sizes and shapes that are suitable for various applications are reviewed. Two main methods, based on liquid-phase synthesis, i.e., chemical methods and bio-based methods, are used to synthesize nanomagnesia. Conventionally, nanomagnesia was synthesized by chemical methods such as coprecipitation, sol-gel, combustion method, and so on using different chemical agents and stabilizers which later on become responsible for several biological risks because of the toxicity of used chemicals. Bio-based protocols are growing as another environmental friend method for the synthesis of various nanostructures especially nanomagnesia using biomass, plant extracts, alga, and fungi as a source of precursor material. The ideal method should offer better control of textural properties of nanostructures and decrease the necessity for purification of the synthesized nanoproducts, which sequentially removes the use of large amounts of chemicals and organic solvents and manipulation of products that are unsafe to the environment. Finally, the broad applicability of nanomagnesia in diverse areas is presented. Employment of nanomagnesia reported in several laboratory and industrial fields are valued from the standpoint of the significance of these issues for technological requests, as described in the literature. Nanomagnesia has various applications such as antimicrobial performance, removing pollutants, batteries application, and catalysis.