Synthesis of ultrathin polymer insulating layers by initiated chemical vapour deposition for low-power soft electronics

Moon, Hanul,Seong, Hyejeong,Shin, Woo Cheol,Park, Won-Tae,Kim, Mincheol,Lee, Seungwon,Bong, Jae Hoon,Noh, Yong-Young,Cho, Byung Jin,Yoo, Seunghyup,Im, Sung Gap Springer Science and Business Media LLC 2015 Nature Materials Vol.14 No.6

Separation of Light Rare Earth Elements and High Activity Nuclides Using Gas Pressurized Extraction Chromatography With Anion Exchange Resin

Sojin Jeong,Hanul Cho,Byungman Kang,Sang Ho Lim,Jihye Kim 한국방사성폐기물학회 2023 한국방사성폐기물학회 학술논문요약집 Vol.21 No.1

This study was performed to evaluate the separation of Sr, Cs, Ba, La, Ce, and Nd using gas pressurized extraction chromatography (GPEC) with anion exchange resin for the quantitation of Neodymium. GPEC is a micro-scaled column chromatography system that provides a constant flow rate by utilizing nitrogen gas. It is overcome the disadvantages of conventional column chromatography by reducing the volume of elution solvent and shortening the analysis time. Here, we compared the conventional column chromatography and the GPEC method. The whole analysis time was decreased by nine times and radioactive wastes were reduced by five times using the GPEC system. Anion exchange resin 1-X4 (200~400 mesh size) was used. The sample was prepared at a 0.8 M nitric acid in methanol solution. The elution solvent was used at a 0.01 M nitric acid in methanol solution. Finally the eluate was analyzed by ICP-MS to determine the identification and recovery. In this case, we applied the natural isotopes of LREEs (139La, 140Ce, and 144Nd) and high activity nuclides (88Sr, 133Cs, and 138Ba) instead of radioactive isotopes for the preliminary test; as a result, unnecessary radioactive waste was not produced. The recoveries were 93.9%, 105.9%, 91.9%, 47.6%, 35.9%, and 79.9% of Sr, Cs, Ba, La, Ce, and Nd, respectively. The reproducibility of recoveries by GPEC were in the range 2.8%–10.9%.

Separation of Sr, Cs and Ba Using Gas Pressurized Extraction Chromatography With Cation Exchange Resin

Sojin Jeong,Hanul Cho,Byungman Kang,Jihye Kim,Sang Ho Lim 한국방사성폐기물학회 2023 한국방사성폐기물학회 학술논문요약집 Vol.21 No.2

During the initial cooling period of spent nuclear fuel, Cs-137 and Sr-90 constitute a large portion of the total decay heat. Therefore, separating cesium and strontium from spent nuclear fuel can significantly decrease decay heat and facilitate disposition. This study presents analytical technique based on the gas pressurized extraction chromatography (GPEC) system with cation exchange resin for the separation of Sr, Cs, and Ba. GPEC is a micro-scaled column chromatography system that allows for faster separation and reduction volume of elution solvent compared to conventional column chromatography by utilizing pressurized nitrogen gas. Here, we demonstrate the comparative study of the conventional column chromatography and the GPEC method. Cation exchange resin AG 50W-X12 (200~400 mesh size) was used. The sample was prepared at a 0.8 M hydrochloric acid solution and gradient elution was applied. In this case, we used the natural isotopes 88Sr, 133Cs, and 138Ba instead of radioactive isotopes for the preliminary test. Usually, cesium is difficult to measure with ICP-OES, because its wavelengths (455.531 nm and 459.320 nm) are less sensitive. So, we used ICP-MS to determine the identification and the recovery of eluate. In this study, optimized experimental conditions and analytical result including reproducibility of the recovery, total analysis time and volume of eluents will be discussed by comparing GPEC and conventional column chromatography.

Separation of nuclide (Sr, Cs, and Ba) using gas pressurized extraction chromatography

Sojin Jeong,Hanul Cho,SangHo Lim,Jihye Kim 한국분석과학회 2023 학술대회논문집 Vol.2023 No.5

Cargo specificity, regulation, and therapeutic potential of cytoplasmic dynein

Park Jin-Gyeong,Jeon Hanul,Hwang Kwang Yeon,Cha Sun-Shin,Han Rafael T.,Cho Hyesung,Lee In-Gyun 생화학분자생물학회 2024 Experimental and molecular medicine Vol.56 No.-

Intracellular retrograde transport in eukaryotic cells relies exclusively on the molecular motor cytoplasmic dynein 1. Unlike its counterpart, kinesin, dynein has a single isoform, which raises questions about its cargo specificity and regulatory mechanisms. The precision of dynein-mediated cargo transport is governed by a multitude of factors, including temperature, phosphorylation, the microtubule track, and interactions with a family of activating adaptor proteins. Activating adaptors are of particular importance because they not only activate the unidirectional motility of the motor but also connect a diverse array of cargoes with the dynein motor. Therefore, it is unsurprising that dysregulation of the dynein-activating adaptor transport machinery can lead to diseases such as spinal muscular atrophy, lower extremity, and dominant. Here, we discuss dynein motor motility within cells and in in vitro, and we present several methodologies employed to track the motion of the motor. We highlight several newly identified activating adaptors and their roles in regulating dynein. Finally, we explore the potential therapeutic applications of manipulating dynein transport to address diseases linked to dynein malfunction.

Synthesis of heavy fermion CeCoIn₅ thin film via pulsed laser deposition

Kim, Jihyun,Lee, Hanul,Lee, Sangyun,Park, Sungmin,Park, Tuson,Cho, YoonHee,Lee, Hyoyoung,Kang, Won Nam,Choi, Woo Seok Elsevier 2019 CURRENT APPLIED PHYSICS Vol.19 No.12

<P><B>Abstract</B></P> <P>CeCoIn<SUB>5</SUB> (Co115) thin films have been grown on Al<SUB>2</SUB>O<SUB>3</SUB> (000l) substrates through the pulsed laser deposition (PLD). The films are grown mainly along the <I>c</I>-axis, with CeIn<SUB>3</SUB> and In-related alloys. The rock-salt type grains are nucleated, where Co115 grains mixed with excess indium are evenly distributed over the substrate. The electrical resistivity of the films shows a Kondo coherence peak near 47 K and the zero-resistance superconducting state at 1.8 K, which is the first observation in the PLD grown thin films of Co115. The Rietveld refinement of the thin films shows that the <I>c</I>/<I>a</I> ratio (tetragonality) is suppressed to 1.6312 from 1.6374 of single crystals, which is consistent with the linear relationship between the superconducting transition temperature and tetragonality. The good agreement indicates that the PLD could provide an alternative route to tune the 2D character of the critical spin fluctuations to understand the superconducting pairing mechanism of Co115.</P> <P><B>Highlights</B></P> <P> <UL> <LI> CeCoIn<SUB>5</SUB> thin films have been grown on an Al<SUB>2</SUB>O<SUB>3</SUB> (000l) substrate via pulsed laser deposition technique. </LI> <LI> The films are mainly oriented along the <I>c</I>-axis, and the rock-salt type grains are nucleated and connected grain by grain. </LI> <LI> The electrical resistivity shows a Kondo coherence peak near 46 K and the superconducting state at 1.8 K. </LI> <LI> The temperature dependence of the upper critical field is in good agreement with that of high-quality single crystals. </LI> </UL> </P>

A rapid separation of Cs, Sr and Ba using gas pressurized extraction chromatography with inductively coupled plasma-mass spectrometry

Sojin Jeong,Jihye Kim,Hanul Cho,Hwakyeung Jeong,Byungman Kang,Sang Ho Lim 한국분석과학회 2024 분석과학 Vol.37 No.2

We present a rapid method for the determination of Cs, Sr, and Ba, heat generators found in highly active liquid wastes, by gas-pressurized extraction chromatography (GPEC) using a column containing a cationexchange resin. GPEC is a microscale column chromatographic technique that uses a constant flow rate of solvent (0.07 mL/min) with pressurized nitrogen gas supplied through a valve. In particular, because this method uses a small sample volume (a few hundred microliters), it produces less chemical waste and allows for faster separation compared to traditional column chromatography. In this study, we evaluated the separation of Cs, Sr, and Ba using GPEC. The eluate from the column (GPEC or conventional column chromatography) was quantitatively analyzed using inductively coupled plasma-mass spectrometry to measure the column recovery and precision. The column reproducibility of the proposed GPEC system (RSDs of recoveries) ranged from 2.7 to 4.1 %, and the column recoveries for the three elements ranged from 72 to 98% when aqueous HCl was used as the eluent. The GPEC results are slightly different in efficiency and separation resolution compared to those of conventional column chromatography because of the differences in the eluent flow rate as well as the internal diameter and length of the column. However, the two methods had similar recoveries for Cs and Sr, and the precision of GPEC was improved by two-fold. Remarkably, the solvent volume required for GPEC analysis was five times lower than that of the conventional method, and the total analysis time was 11 times shorter.

Low-Voltage High-Performance Pentacene Thin-Film Transistors With Ultrathin PVP/High- <tex> $\kappa$</tex> HfLaO Hybrid Gate Dielectric

Woo Cheol Shin,Hanul Moon,Seunghyup Yoo,Yuxiang Li,Byung Jin Cho IEEE 2010 IEEE electron device letters Vol.31 No.11

<P>Low-voltage and high-performance pentacene thin-film transistors with a hybrid gate dielectric consisting of ultrathin PVP (8 nm) and a high-κ HfLaO (20 nm) have been demonstrated. The hybrid gate dielectric exploits the advantages of both dielectrics, i.e., a good interface between the organic dielectric and channel material as well as the insulating properties of the inorganic metal-oxide, resulting in very low leakage current, hysteresis-free behavior, superior drain-current drivability, and successful operation at -2 V. The superior device performance is attributed to good intermolecular ordering and the large grain size of the pentacene channel layer formed on the hybrid dielectric.</P>

Identification of peptide based B-cell epitopes in Zika virus NS1

Lee, Hee-Jung,Cho, Yeondong,Kang, Hyeon Jeong,Choi, Hanul,Han, Kang Rok,Chong, Chom Kyu,Kim, Young Bong Elsevier 2018 Biochemical and biophysical research communication Vol.505 No.4

<P><B>Abstract</B></P> <P>Zika virus (ZIKV), a mosquito-borne flavivirus that has recently emerged globally, poses a major threat to public health. To control this emerging disease, accurate diagnostics are required for monitoring current ZIKV outbreaks. Owing to the high nucleotide sequence similarity and cross-reactivity of ZIKV with other members of the Flaviviridae family, discrimination from other flavivirus infections is often difficult in endemic areas. ZIKV NS1 induces major virus-specific antibodies and is therefore utilized as a serological marker for ZIKV diagnosis. To identify ZIKV specific epitopes for clinical application, 33 NS1 peptides that are 15–30 amino acid in length covering whole NS1 were synthesized and analyzed linear B-cell epitopes with 38 human serum samples (20 ZIKV-positive and 18 ZIKV-negative). As a result of screening, eight epitope regions were identified. In particular, the Z8 and Z14 peptides located in the β-ladder surface region showed higher levels of binding activity in ZIKV-positive sera without cross-reactivity to other flaviviruses. These identified sensitive and specific epitopes provide a tool for design of diagnostics and structure-based vaccine antigens for ZIKV infection.</P> <P><B>Highlights</B></P> <P> <UL> <LI> B-cell epitope mapping in ZIKV NS1. </LI> <LI> Identification of the ZIKV NS1 specific antibody binding site. </LI> <LI> Tool for design of diagnostics and structure-based vaccine against ZIKV. </LI> </UL> </P>

지하철역 승강장 유도 사인시스템에 관한 연구

이석희(Seokhee Lee),장한얼(Hanul Jang),조우상(Woosang Joo),민훈기(Hungi Min),조광수(Kwangsu Cho) 한국HCI학회 2013 한국HCI학회 학술대회 Vol.2013 No.1

지하철 사인시스템은 지하철 이용객에게 목적지로 향하는 열차에 대한 정보를 보다 쉽고 정확하게 알려주어야 한다. 하지만 현재의 지하철 사인시스템은 선적인 인지(Linear cognition)유도하는 사인시스템 방식을 채택함으로써, 이용객들이 수행하는 지하철 노선도 중심의 공간적 인지(Spatial cognition)와 다소 거리가 있는 정보를 담아내고 있다. 따라서 본 연구는 실험 방법론을 통해서, 지하철 사인시스템에 추가한 방향 정보가 지하철 이용객의 정확한 승강장 선택에 미치는 영향에 대해 알아보았다. 그 결과, 현 승강장 사인시스템은 이용객들의 올바른 승강장 유도에 유용하지 않으며, 사인시스템에 이용객의 인지 상태를 반영한 방향 정보가 추가되었을 때 이용객들의 승강장 결정이 더욱 용이해졌음을 확인했다. 본 연구는 지하철 길 찾기 시 방향 정보 전달에 있어 종점과 주요역 표기 사인시스템이 갖는 문제점에 대해 고찰한다. Subway signage systems in Seoul tend to make users or passengers confused. A major problem with the systems is that the current signage only shows end station names on either direction of a train. In other words, strange passengers whose destination stations are not the end stations have significant difficulties of finding their ways to take right trains. This study has the purpose of investigating the effects of directional information on signage system to find proper platform on subway station. The research shows that passengers are confused by present signage system but user’s performances were improved when directional information was suggested in signage system.