Dynamic Concentration and Separation by Isoelectric Focusing in Microfluidic Channel

Kwangsuk Yang(양광석),Philippe Clementz,Tae Jung Park(박태정),Jong Pil Park(박종필),Seok Jae Lee(이석재),Do Hyun Kim(김도현),Sang Yup Lee(이상엽) 한국생물공학회 2004 한국생물공학회 학술대회 Vol.2004 No.4

Engineered biochar composite fabricated from red mud and lipid waste and synthesis of biodiesel using the composite

Yoon, Kwangsuk,Jung, Jong-Min,Cho, Dong-Wan,Tsang, Daniel C.W.,Kwon, Eilhann E.,Song, Hocheol Elsevier 2019 Journal of hazardous materials Vol.366 No.-

<P><B>Abstract</B></P> <P>Co-pyrolysis of lipid waste and red mud was investigated to achieve valorization of red mud by fabricating biochar composite. For the further sustainable approach, this study intentionally employed carbon dioxide (CO<SUB>2</SUB>) as reaction medium in the co-pyrolysis process. The use of CO<SUB>2</SUB> on co-pyrolysis of lipid waste and red mud enabled manipulation of the carbon distributions between pyrogenic products. CO<SUB>2</SUB> expedited the thermal cracking of lipid waste and further reacted with lipid waste during the thermolysis. These mechanistic roles of CO<SUB>2</SUB> were catalytically enhanced by the presence of mineral phases (Fe<SUB>2</SUB>O<SUB>3</SUB>) in red mud, thereby resulting in the enhanced formation of CO (40 times more at 550 °C). However, CO<SUB>2</SUB> suppressed dehydrogenation of lipid waste (∼ 50%), which resulted in the different pathway for reducing iron oxide in red mud. Moreover, as an aspect of valorization of red mud, catalytic capability of biochar composite was evaluated. As a case study, biodiesel (FAMEs) were synthesized, and all experimental findings suggested that biochar composite could be an effective catalyst for biodiesel synthesis. As compare to biodiesel synthesis using silica (92% yield at 360 °C), the equivalent biodiesel yield was achieved with the biochar at much lower temperature (130 °C).</P> <P><B>Highlights</B></P> <P> <UL> <LI> Valorization of red mud and lipid waste via the thermo-chemical process. </LI> <LI> Enhanced energy recovery in the thermo-chemical process using CO<SUB>2</SUB>. </LI> <LI> Fabrication of biochar composite from red mud and lipid waste. </LI> <LI> Biodiesel synthesis using biochar composite. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

고조파 조절기 형상이 자석 기어의 코깅 자기력에 미치는 영향 분석

정광석,Kwangsuk, Jung 한국교통대학교 융복합기술연구소 2022 융ㆍ복합기술연구소 논문집 Vol.12 No.1

The reduction ratio of the magnetic gear is determined by the ratio of the number of poles between the high-speed permanent magnet layer and the low-speed permanent magnet layer. In general, it is known that the greater the least common multiple of both poles, the smaller the torque ripple called by cogging of the magnetic force generated in the magnetic gear. However, little is known about the effect of the harmonic modulator that filters the magnetic field in the magnetic gear to magnetically couple the high-speed side and the low-speed side except for the number of poles. In this study, torque ripple characteristics according to changes in modulator shape such as opening ratio and tooth thickness are analyzed using a finite element analysis tool.

자기 포커싱 방법을 적용한 감속 장치의 자기력 특성에 관한 연구

정광석,Jung, Kwangsuk 한국교통대학교 융복합기술연구소 2021 융ㆍ복합기술연구소 논문집 Vol.11 No.1

The magnetic gear, which amplifies the torque by filtering the magnetic field generated by the low-speed permanent magnet with a modulator, can exclude gear contact and can be effectively applied when there are environmental restrictions. In this paper, we discuss the magnetic force characteristics of a magnetic gear using a magnetic focusing array that replaces a general permanent magnet array magnetized in a radial direction along the circumferential direction. The torque increasing effect of the discussed array, known as an arrangement that increases the principal component by focusing a radial magnetic field, is compared with that of a general magnetic gear. In particular, in a magnetic gear using such an array, the sensitivity of torque according to variables is analyzed to see how various variables known as factors affecting torque have an effect.

부분 모드만을 고려하여 성형된 입력을 이용한 잔류 진동의 감소 효과

정광석,Jung, Kwangsuk 한국교통대학교 융복합기술연구소 2011 융ㆍ복합기술연구소 논문집 Vol.1 No.1

Shaping an input command through considering the resonant modes of multi degrees of freedom system, it is possible to realize the wanted motion, without exciting the uncontrollable modes of the flexible system. But, an increase of modes to be considered brings inevitably about the time delay due to an excessive rising time. On the purpose of reducing the rising time, only the interesting and dominant modes can be considered to determine the timing pulses of input shaper. In this paper, an effect of shaper by the partial modes is analysed for a specific system and the input shapers by the partial modes are analysed for three d.o.f damped system, using Matlab simulation.

자기 폐회로를 갖는 마그네트 기어의 변수 설계

정광석,Jung, Kwangsuk 한국교통대학교 융복합기술연구소 2015 융ㆍ복합기술연구소 논문집 Vol.5 No.2

A novel topology for the magnet gear is proposed in this study. Differently from the existing methods, both sides of magnet array in this topology are used, resulting in increasing the efficiency of the mechanism. The closed magnetic path between the magnetic elements decreases the leakage flux, so the interlinking magnetic flux through the air-gap is focused and intensified. This paper discusses the dominant parameters of the proposed magnet gear influencing the resulting transmission torque. The parameters are designed from the sensitivity analysis using the commercial FEM analysis tool. And, the test setup for verifying the performance of the system is described.

래디알 동전기 휠의 다축력 특성

정광석,Jung, Kwangsuk 한국교통대학교 융복합기술연구소 2017 융ㆍ복합기술연구소 논문집 Vol.7 No.2

The rotating electrodynamic wheel over a conductive plate produces thrust force as well as normal force. Specially, separating the conductive plate and spacing apart each part, the lateral stability of the rotating wheel is guaranteed due to the restoring force into neutral position. In this paper, the force characteristics of the electrodynamic wheel rotating over the conductive plate is analyzed using the finite element tool. First, the dominant parameters are identified considering the geometric configuration and the operating condition. And the sensitivity for the parameter deviation is quantified for the high force density. The above topology can be applied as an actuating principle for inter-city train as well as contact-free transfer device.

마그네틱 기어드 모터의 자석 기어 자기력 해석 및 설계

정광석,Kwangsuk Jung 한국교통대학교 융복합기술연구소 2023 융ㆍ복합기술연구소 논문집 Vol.13 No.1

The built-in motor with an integrated magnetic gear can realize high torque without a separate reduction device. In this paper, the main design parameters of the magnetic gear constituting the magnetic geared motor are derived and the sensitivity analysis results according to these design parameters are discussed. In particular, processing and assembly issues of modulators sandwiched between rotating bodies are discussed, and loss and magnetic force characteristics of various types of modulators are introduced. Since the modulator, which plays a key role in converting the torque of the magnetic gear, is desirable to have a separate form, it is inevitable to add a non-magnetic support to add torsional stiffness according to high-speed rotation, so the effect of this is also analyzed.

고정밀 서피스 서보 방법론

정광석,박준규,심기본,Jung, Kwangsuk,Park, Junkyu,Shim, Kibon 한국교통대학교 융복합기술연구소 2013 융ㆍ복합기술연구소 논문집 Vol.3 No.1

High-precision surface actuator, in which in-plane motion is realized by not two-dimensional actuator superposing linear actuators but integrated planar actuator, has been developed to cope with the severe target performance like precise motion with large envelope. It is very difficult to accomplish the performance with the traditional actuating principle. So, various methods have been tried to break through the problem. This paper discusses some meaningful trials performed in the Nano Measurement and Precision Motion Control Lab. of Korea National University of Transportation.

액시얼 마그네틱 하모닉 기어의 특성 해석

원훈희,정광석,Won, Hunhee,Jung, Kwangsuk 한국교통대학교 융복합기술연구소 2020 융ㆍ복합기술연구소 논문집 Vol.10 No.1

Magnetic gears of non-contact power type have great advantages in terms of maintenance and repair than mechanical gears, and are used in various ways. Harmonic gears can derive a higher gear ratio than conventional gears through power transmission through a unique rotation mechanism. Magnetic harmonic gears, in which the gear teeth of the harmonic gears are replaced with magnets, have the advantages of both gears, but are difficult to implement and practical, so many studies are being conducted. In this study, we check whether the results of various types of magnetic gears can be applied to harmonic gears. By applying the axial type magnetic gear to the harmonic gear, the characteristic analysis is conducted to see if the result comparable to the existing radial type magnetic harmonic gear is obtained.