스마트폰에 접속 가능한 소형 혈당 모듈

김경아, 이인광, 허아롱, 김경옥, 차은종 충북대학교 의과대학 충북대학교 의학연구소 2014 忠北醫大學術誌 Vol.24 No.1

연구목적: 스마트폰에 접속하여 혈당을 측정할 수 있는 소형 혈당 모듈을 개발하여 그 유용성을 실험 적으로 검증하고자 하였다. 대상 및 방법: 혈액이 전극에 주입되어 생성되는 전류가 전압의 형태로 변환되어 혈당값으로 변환되는 전기화학적 측정 원리를 적용하여 소형 혈당 모듈을 개발하였다. 혈당 모듈의 최소한의 측정 혈액 양은 0.5 μL이며, 5초 이내로 측정이 가능하도록 설계 및 제작하였다. 스마트폰과의 통신은 frequencyshift keying(FSK) 모뎀 방식을 적용하였다. 혈당 모듈의 정확도 실험을 위해 시판되는 혈당계와 인 공혈액으로 비교 실험을 수행하였다. 결과: 시판되는 제품과의 성능 비교 실험에서 시판 제품은 391 mg/dL를 나타내었으며, 소형 혈당 모 듈은 401 mg/dL를 나타내었다. 혈당 모듈의 크기는 50×30×7 mm로서 휴대의 편리성을 높였다. 결론: 스마트폰 기반의 소형 혈당 모듈을 개발하였으며, 기존 제품과의 혈당 측정 상대오차가 약 2.6%로서 정확한 혈당 측정이 가능함을 실험적으로 검증하였다.

Synergy effects of Al₂O₃ promoter on a highly ordered mesoporous heterogeneous Rh-g-C₃N₄ for a liquid-phase carbonylation of methanol

Kim, Da Mi,Kim, A Rong,Chang, Tae Sun,Koo, Hyun Mo,Kim, Jung Kyu,Han, Gui Young,Shin, Chae-Ho,Bae, Jong Wook Elsevier 2019 Applied catalysis. A, General Vol.585 No.-

<P><B>Abstract</B></P> <P>The effects of Lewis acid Al<SUB>2</SUB>O<SUB>3</SUB> on Rh-incorporated mesoporous g-C<SUB>3</SUB>N<SUB>4</SUB> (AlRh-CN) were investigated to verify an enhanced activity and stability in a liquid-phase carbonylation of methanol. The novel AlRh-CN with 2.0 wt%Al (Al(2)Rh-CN) revealed a higher yield of acetic acid (AA) and methyl acetate (MA) with a small Rh leaching. The enhanced activity on the optimal Al(2)Rh-CN was attributed to the highly dispersed and partially reduced Rh nanoparticles by preserving initial oxidation states as well as by maintaining its stronger interaction on the Al-modified g-C<SUB>3</SUB>N<SUB>4</SUB> surfaces. Its superior activity was originated from the highly dispersed Lewis acid Al<SUP>3+</SUP> sites assigned to Al<SUB>2</SUB>O<SUB>3</SUB> phases due to an increased reverse esterification reaction rate. The higher activity on the Al(2)Rh-CN was originated from synergy effects such as a larger Lewis acid Al<SUB>2</SUB>O<SUB>3</SUB> sites acting as a pillaring material to increase specific surface area of Al(2)Rh-CN and to increase a reverse esterification reaction.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Synergy effect of Al promoter was observed on a highly ordered mesoporous heterogeneous AlRh-CN. </LI> <LI> Novel AlRh-CN with 2.0 wt%Al showed a higher AA yield of with less leaching of Rh species. </LI> <LI> Lewis acid Al sites increased a reverse esterification reaction of MA to AA by hydrolysis reaction. </LI> <LI> A robust preservation of larger amount of acidic Al<SUP>3+</SUP> sites and high surface area of metallic Rh are crucial. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Lewis acid Al<SUB>2</SUB>O<SUB>3</SUB> promoter on the highly ordered mesoporous heterogeneous Rh-incorporated graphitic carbon nitride (mpg-C<SUB>3</SUB>N<SUB>4</SUB>) largely enhanced the catalytic activity and stability in a liquid-phase carbonylation of methanol to acetic acid (AA) by increasing a reverse esterification activity of methyl acetate (MA) intermediate to AA.</P> <P>[DISPLAY OMISSION]</P>

Design of a 10 kJ Class SMES Model Coil for Real Time Digital Simulator Based Grid Connection Study

A-Rong Kim,Hee-Yeol Jung,Jae-Ho Kim,Minwon Park,In-Keun Yu,Seok-Ho Kim,Kideok Sim,Hae-Jong Kim,Ki-Chul Seong IEEE 2009 IEEE transactions on applied superconductivity Vol.19 No.3

<P>Superconducting magnetic energy storage (SMES) system is having increased attention in power system application because of its higher efficiency and faster response. Before the installation of the SMES into utility, the system analysis has to be carried out with a certain simulation tool. Using the Real Time Digital Simulator (RTDS), electrical properties of the miniaturized SMES model coil (75 J) for voltage sag compensation were demonstrated through a previous research work. The simulation results represented the same characteristics as those of large capacity SMES coil (1 MJ). Based on these results, design specifications of the 10 kJ SMES model coil were developed and several necessary analyses were performed for the RTDS based grid connection study in this work.</P>

Analyzed Model of The Active Filter combined with SMES

Kim A-Rong,Kim Jae-Ho,Kim Hae-Jong,Kim Seok-Ho,Seong Ki-Chul,Park Min-Won,Yu In-Keun The Korean Society of Superconductivity and Cryoge 2006 한국초전도저온공학회논문지 Vol.8 No.2

Recently, utility network is becoming more and more complicated and huge due to IT and OA devices. In addition to, demands of power conversion devices which have non-linear switching devices are getting more and more increased. Consequently, because of the non-linear power semiconductor devices, current harmonics are unavoidable. Sometimes those current harmonics flow back to utility network and become one of the main reasons which can make the voltage distortion. Also, it makes noise and heat loss. On the other hands, voltage sag from sudden increasing loads is also one of the terrible problems inside of utility network. In order to compensate the current harmonics and voltage sag problem, AF(active filter) systems could be a good solution method. SMES is a very good promising source due to it's high response time of charge and discharge. Therefore, the combined AF and SMES system can be a wonderful device to compensate both harmonics current and voltage sag. However, SMES needs a superconducting magnetic coil. Because of using this superconducting magnetic coil, quench problem caused by unexpected reasons have always been unavoidable. Therefore, to solve out mentioned above, this paper presents a decisive method using shunt and series active filter system combined with SMES. Especially, authors analyzed the change of original energy capacity of SMES regarding to the size of resistance caused by quench of superconducting magnetic coil.

Performance Analysis of a Toroid-Type HTS SMES Adopted for Frequency Stabilization

A-Rong Kim,Sang-Yong Kim,Kwang-Min Kim,Jin-Geun Kim,Seokho Kim,Minwon Park,In-Keun Yu,Sangjin Lee,Myung-Hwan Sohn,Hae-Jong Kim,Joon-Han Bae,Ki-Chul Seong IEEE 2011 IEEE transactions on applied superconductivity Vol.21 No.3

<P>Superconducting magnetic energy storage (SMES) can overcome fluctuations in frequency because of its fast response time in charging and discharging energy. To stabilize the fluctuations in frequency of wind power generation systems (WPGSs), HTS SMES systems should be connected to the terminal of the WPGSs. Ulleung Island's power network in Korea was modeled with a real-time digital simulator (RTDS) to demonstrate the effectiveness of SMES at stabilizing frequency. A toroid-type HTS SMES cooled by conduction cooling and a DC/DC chopper to charge and discharge current were fabricated for the experiment. The simulation results show the frequency stabilization effected by the HTS SMES system with its operational characteristics such as real time variation in current and temperature.</P>

Ni/M-Al₂O₃ (M=Sm, Ce or Mg) for combined steam and CO₂ reforming of CH₄ from coke oven gas

Kim, A Rong,Lee, Hye Yong,Cho, Jae Min,Choi, Joon-Hwan,Bae, Jong Wook Elsevier Science B.V. Amsterdam 2017 Journal of CO₂ utilization Vol.21 No.-

<P><B>Abstract</B></P> <P>Effects of structural promoters such as Sm, Ce, Mg metal oxides on the Ni/M-Al<SUB>2</SUB>O<SUB>3</SUB> catalysts (where M=Sm, Ce, or Mg) were verified to elucidate different catalytic activity for a combined steam and CO<SUB>2</SUB> reforming reaction with CH<SUB>4</SUB> (CSCR) using H<SUB>2</SUB>-rich coke oven gases generated from steel industry. The enhanced catalytic performance and stability were explained in terms of the variations of surface basic sites with different aggregation phenomena of active nickel crystallites and resistances for a coke formation. The most efficient Sm promoter having a high electronegativity and basic property on the Ni/M-Al<SUB>2</SUB>O<SUB>3</SUB> was found to largely suppress a coke deposition and less aggregation of active nickel crystallites by forming the strongly interacted nickel nanoparticles with an enhanced basic sites on the Sm-modified Al<SUB>2</SUB>O<SUB>3</SUB>. In addition, a larger amount of basic sites on the Ni/Sm-Al<SUB>2</SUB>O<SUB>3</SUB> were responsible for a less coke deposition and best catalytic performances in terms of the conversions of CH<SUB>4</SUB> and CO<SUB>2</SUB>. These positive effects of Sm promoter were also attributed to a relatively easy activation of CO<SUB>2</SUB> and the formation of the strongly interacted smaller nickel crystallites on the newly formed basic perovskite-like SmAlO<SUB>3</SUB> structures or segregated Sm<SUB>2</SUB>O<SUB>3</SUB> species.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Ni/M-Al<SUB>2</SUB>O<SUB>3</SUB> (M=promoter of Sm, Ce, or Mg) were verified for combined steam and CO<SUB>2</SUB> reforming with CH<SUB>4</SUB> (CSCR). </LI> <LI> Basic SmOx was to suppress the coke deposition and less aggregation of Ni crystallites. </LI> <LI> Strongly interacted Ni crystallites on the basic perovskite-like surfaces are responsible for a high CSCR activity. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Design and Manufacturing of a SMES Model Coil for Real Time Digital Simulator Based Power Quality Enhancement Simulation

A-Rong Kim,Gyeong-Hun Kim,Kwang-Min Kim,Jin-Geun Kim,Dae-Won Kim,Minwon Park,In-Keun Yu,Seok-Ho Kim,Kideok Sim,Ki-Chul Seong IEEE 2010 IEEE transactions on applied superconductivity Vol.20 No.3

<P>The Superconducting Magnetic Energy Storage (SMES) system is a key technology for overcoming the voltage sag, swell, interruption, and frequency fluctuation with the fast response speed of current charge and discharge. A toroidal-type SMES is designed using a 3D CAD program, and the inductance and AC loss characteristic during operation are analysed using Finite Element Method (FEM) program. The toroidal-type magnet consists of 30 double pancake coils (DPC). The single pancake coils (SPC), constituting the double pancake coils, are arranged at an angle of 6° from each other, based on the central axis of the toroidal-type magnet. The conduction cooling method is used for the toroidal-type SMES cooling. To evaluate the characteristics of the over-mega-joule class grid-connected HTS SMES system, the authors implemented a simulation by which the SMES coil could be connected to the Real Time Digital Simulator (RTDS). Using the simulation, users can perform voltage sag and frequency stabilization simulations with a real SMES coil in real time and easily change the capacity of the SMES system as much as they need. The effectiveness of the toroidal-type HTS SMES system is demonstrated through the RTDS-based simulation and the results are briefly discussed.</P>

Operating Characteristic Analysis of HTS SMES for Frequency Stabilization of Dispersed Power Generation System

A-Rong Kim,Hyo-Ryong Seo,Gyeong-Hun Kim,Minwon Park,In-Keun Yu,Otsuki, Yusuke,Tamura, Junji,Seok-Ho Kim,Kideok Sim,Ki-Chul Seong IEEE 2010 IEEE transactions on applied superconductivity Vol.20 No.3

<P>This paper analyses operating characteristic of high temperature superconducting magnetic energy storage (HTS SMES) for frequency stabilization of dispersed power generation system. The wind power generation system (WPGS) fluctuates due to wind speed variation and affects the frequency and voltage fluctuations of the utility. SMES is probably a key technology to overcome these fluctuations. To stabilize power system frequency, a large-scale HTS SMES is connected to the terminal of the WPGS. The authors analysed the load side frequencies using two different configurations of SMES, one consisting of a single magnet and the other of a dual magnet. From the simulation results, it can be concluded that the SMES is a useful device for stabilizing the power system frequency fluctuations, and a dual magnet type SMES is more effective for frequency stabilizing but exhibits more AC loss due to the increased operating current than a single magnet type.</P>

내부고장을 고려한 AF-SMES 시스템의 시뮬레이션 해석 및 제작에 관한 연구

김아롱(A-Rong Kim),김재호(Jae-Ho Kim),김해종(Hae-Jong Kim),김석호(Seok-Ho Kim),성기철(Ki-Chul Seong),박민원(Minwon Park),유인근(In-Keun Yu) 대한전기학회 2006 대한전기학회 학술대회 논문집 Vol.2006 No.7

Recently, utility network is getting more and more complicated and huge. In addition to, demands of power conversion devices which have non-linear switching devices are getting more and more increased. Consequently, according to the non-linear power semiconductor devices, current harmonics are unavoidable. Those current harmonics flow back to utility network and become one of the reasons which make the voltage distortion. On the other hands, voltage sag from sudden increasing loads is also one of the terrible problems inside of utility network. In order to compensate the current harmonics and voltage sag problem, AF(Active Filter) systems could be a good solution method and SMES(Superconducting Magnetic Energy Storage) system is a very good promising source due to the high response time of charge and discharge. Therefore, the combined system of AF and SMES is a wonderful device to compensate both harmonics current and voltage sag. However, unfortunately SMES needs a superconducting magnetic coil. Because of the introduction of superconducting magnetic coil, quench problem caused by unexpected reasons is always existed. In case of discharge operation, quench is a significantly harmful factor according as it decreases the energy capacity of SMES. Therefore, this paper presents a decision method of the specification of the AF-SMES system considering internal fault condition. Especially, authors analyzed the change of the original energy capacity of SMES regarding to the size of resistance caused by quench of superconducting magnetic coil. Finally, based on this simulation, authors manufactured actual Active Filter System using DSP.

Novel heterogeneous Rh-incorporated graphitic-carbon nitride for liquid-phase carbonylation of methanol to acetic acid

Nam, J.S.,Rong Kim, A.,Kim, D.M.,Chang, T.S.,Kim, B.S.,Bae, J.W. ELSEVIER 2017 CATALYSIS COMMUNICATIONS Vol.99 No.-

A novel heterogeneous rhodium-incorporated graphitic carbon nitride (Rh-g-C<SUB>3</SUB>N<SUB>4</SUB>) was investigated for a liquid-phase carbonylation of methanol to acetic acid (AA) to overcome disadvantages of the commercialized Rh-based homogeneous catalysts. The heterogeneous Rh-g-C<SUB>3</SUB>N<SUB>4</SUB> catalyst showed a superior catalytic activity in a liquid-phase carbonylation with AA yield above 82% under the reaction conditions of 413K and CO pressure of 4.0MPa, where the initially formed MA intermediate can be easily hydrolyzed to form AA. A higher dispersion of the incorporated rhodium nanoparticles in the g-C<SUB>3</SUB>N<SUB>4</SUB> matrix with a small crystallite size was responsible for a higher catalytic activity with a less leaching degree of active rhodium metals. The novel Rh-g-C<SUB>3</SUB>N<SUB>4</SUB> with rhodium content of 1-3wt% can be a candidate to substitute the commercial homogeneous Rh complex catalyst for AA production by methanol carbonylation.