419 results on '"Tae Hee Han"'
Search Results
2. Grafting Behavior of Amine Ligands for Surface Modification of MXene
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Hwansoo Shin, Hyeonhoo Lee, Yeongbhin Seo, Woojae Jeong, and Tae Hee Han
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Electrochemistry ,General Materials Science ,Surfaces and Interfaces ,Condensed Matter Physics ,Spectroscopy - Published
- 2023
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3. NCDE: In-Network Caching for Directory Entries to Expedite Data Access in Tiled-Chip Multiprocessors
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Jae Eun Shim, Mingu Kang, and Tae Hee Han
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General Computer Science ,General Engineering ,General Materials Science ,Electrical and Electronic Engineering - Published
- 2023
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4. MRCN: Throughput-Oriented Multicast Routing for Customized Network-on-Chips
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Young Sik Lee, Yong Wook Kim, and Tae Hee Han
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Computational Theory and Mathematics ,Hardware and Architecture ,Signal Processing - Published
- 2023
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5. Binarized Neural Network With Parameterized Weight Clipping and Quantization Gap Minimization for Online Knowledge Distillation
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Ju Yeon Kang, Chang Ho Ryu, and Tae Hee Han
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General Computer Science ,General Engineering ,General Materials Science ,Electrical and Electronic Engineering - Published
- 2023
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6. BER-based Hybrid Partitioning Technique for Improving Lifetime and Write Performance of High-density NAND Flash SSD
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Gi-Jae Choi, Jeong-Hun Kim, and Tae-Hee Han
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- 2022
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7. Advances in Porous Graphene and Scalable Wet-Spinning Fiber Assembly
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Rohan B. Ambade, Ki Hyun Lee, Dong Jun Kang, and Tae Hee Han
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Polymers and Plastics ,Materials Science (miscellaneous) ,Materials Chemistry ,Chemical Engineering (miscellaneous) - Published
- 2022
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8. Suppressing ion migration in metal halide perovskite via interstitial doping with a trace amount of multivalent cations
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Yepin Zhao, Ilhan Yavuz, Minhuan Wang, Marc H. Weber, Mingjie Xu, Joo-Hong Lee, Shaun Tan, Tianyi Huang, Dong Meng, Rui Wang, Jingjing Xue, Sung-Joon Lee, Sang-Hoon Bae, Anni Zhang, Seung-Gu Choi, Yanfeng Yin, Jin Liu, Tae-Hee Han, Yantao Shi, Hongru Ma, Wenxin Yang, Qiyu Xing, Yifan Zhou, Pengju Shi, Sisi Wang, Elizabeth Zhang, Jiming Bian, Xiaoqing Pan, Nam-Gyu Park, Jin-Wook Lee, Yang Yang, and Zhao Y., YAVUZ İ., Wang M., Weber M. H. , Xu M., Lee J., Tan S., Huang T., Meng D., Wang R., et al.
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Kimya (çeşitli) ,Temel Bilimler (SCI) ,Physical Chemistry ,MATERIALS SCIENCE ,Kimya ,CHEMISTRY ,Materials Chemistry ,Yoğun Madde Fiziği ,General Materials Science ,Malzeme Kimyası ,Temel Bilimler ,Physics ,KİMYA, FİZİKSEL ,Metals and Alloys ,Fizikokimya ,Surfaces and Interfaces ,Condensed Matter Physics ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Chemistry (miscellaneous) ,Mechanics of Materials ,Natural Sciences (SCI) ,Physical Sciences ,Engineering and Technology ,Natural Sciences ,İstatistiksel ve Doğrusal Olmayan Fizik ,FİZİK, YOĞUN MADDE ,Yüzeyler, Kaplamalar ve Filmler ,CHEMISTRY, PHYSICAL ,Fiziksel ve Teorik Kimya ,MATERIALS SCIENCE, MULTIDISCIPLINARY ,Fizik ,Metaller ve Alaşımlar ,Elektronik, Optik ve Manyetik Malzemeler ,PHYSICS, CONDENSED MATTER ,Physical and Theoretical Chemistry ,MALZEME BİLİMİ, ÇOKDİSİPLİNLİ ,Engineering, Computing & Technology (ENG) ,PHYSICS, APPLIED ,Mechanical Engineering ,Yüzeyler ve Arayüzler ,Mühendislik, Bilişim ve Teknoloji (ENG) ,Statistical and Nonlinear Physics ,General Chemistry ,Condensed Matter 1: Structural, Mechanical and Thermal Properties ,Yoğun Madde 1:Yapısal, Mekanik ve Termal Özellikler ,Genel Kimya ,Fizik Bilimleri ,FİZİK, UYGULAMALI ,Genel Malzeme Bilimi ,Mühendislik ve Teknoloji ,Malzeme Bilimi - Abstract
Cations with suitable sizes to occupy an interstitial site of perovskite crystals have been widely used to inhibit ion migration and promote the performance and stability of perovskite optoelectronics. However, such interstitial doping inevitably leads to lattice microstrain that impairs the long-range ordering and stability of the crystals, causing a sacrificial trade-off. Here, we unravel the evident influence of the valence states of the interstitial cations on their efficacy to suppress the ion migration. Incorporation of a trivalent neodymium cation (Nd3+) effectively mitigates the ion migration in the perovskite lattice with a reduced dosage (0.08%) compared to a widely used monovalent cation dopant (Na+, 0.45%). The photovoltaic performances and operational stability of the prototypical perovskite solar cells are enhanced with a trace amount of Nd3+ doping while minimizing the sacrificial trade-off.
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- 2022
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9. Joule heating-induced faradaic electrode-decorated graphene fibers for flexible fiber-shaped hybrid supercapacitor with high volumetric energy density
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Hak Bong Lee, Ganesh Kumar Veerasubramani, Kyong Sub Lee, Hyeonhoo Lee, and Tae Hee Han
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General Materials Science ,General Chemistry - Published
- 2022
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10. PSR Operation-specific Adaptive Lossless Image Compression Technique for Reducing the External Memory Accesses of Mobile Display Driver ICs
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Jae-woo Song and Tae-Hee Han
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- 2022
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11. Analysis on Three-Phase Ground Fault Current Limiting Operations of Three-Phase Transformer Type SFCL Using Two Superconducting Modules
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Tae-Hee Han, Seok-Cheol Ko, and Sung-Hun Lim
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Electrical and Electronic Engineering ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials - Published
- 2022
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12. A roadmap for the commercialization of perovskite light emitters
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Tae-Hee Han, Kyung Yeon Jang, Yitong Dong, Richard H. Friend, Edward H. Sargent, and Tae-Woo Lee
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Biomaterials ,Materials Chemistry ,Surfaces, Coatings and Films ,Energy (miscellaneous) ,Electronic, Optical and Magnetic Materials - Published
- 2022
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13. Tracking the thermal dynamics of Ti3C2Tx MXene with XPS and two-dimensional correlation spectroscopy
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Wonsik Eom, Hwansoo Shin, and Tae Hee Han
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Physics and Astronomy (miscellaneous) - Abstract
MXenes are a class of two-dimensional materials with potential applications in the fields such as thermal management and high-temperature materials. In this study, the transitions of Ti3C2Tx MXene are investigated during thermal annealing via x-ray photoelectron spectroscopy and two-dimensional correlation spectroscopy. The thermal evolution of MXene samples occurs as two distinct processes in different temperature regions: process I (from 25 to 500 °C) and process II (from 500 to 777 °C). In process I, the terminal groups of MXene are reduced, and fluorine (–F) terminal groups are released. Four different pathways are identified with C–Ti–O and C–C as probable final products. In process II, the reaction resulting in the removal of –F species and decomposition of the Ti3C2 region in the MXene is observed. These results provide insight into the thermal decomposition behavior of Ti3C2Tx MXene, which can assist in the design of MXene-based materials with specific functionalities.
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- 2023
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14. FSP1 and NRF2 independently contribute to ferroptosis resistance in KEAP1 mutant non-small cell lung carcinoma
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JongWoo KIM, Min-Ju Kim, Tae-Hee Han, Ji-Yoon Lee, Sangok Kim, Hyerin Kim, Kyoung-Jin Oh, Won-Kon Kim, Baek-Soo Han, Kwang-Hee Bae, Hyun Seung Ban, Soo Han Bae, SC Lee, Haeseung Lee, and Eun-woo Lee
- Abstract
Ferroptosis, a type of cell death induced by lipid peroxidation, has emerged as a novel anti-cancer strategy. Cancer cells frequently acquire resistance to ferroptosis. However, the underlying mechanisms are poorly understood. To address this issue, we conducted a thorough investigation of the genomic and transcriptomic data derived from hundreds of human cancer cell lines and primary tissue samples, with a particular focus on non-small cell lung carcinoma (NSCLC). It was observed that mutations in Kelch-like ECH-associated protein 1 (KEAP1) and subsequent nuclear factor erythroid 2-related factor 2 (NRF2, also known as NFE2L2) activation are strongly associated with ferroptosis resistance in NSCLC. Additionally, AIFM2 gene, which encodes ferroptosis suppressor protein 1 (FSP1),was identified as the gene most significantly correlatedwith ferroptosis resistance, followed by multiple NRF2 targets. We found that inhibition of NRF2 alone was not sufficient to reduce FSP1 protein levels and promote ferroptosis, whereas FSP1 inhibition effectively sensitized KEAP1-mutant NSCLC cells to ferroptosis. Furthermore, we found that combined inhibition of FSP1 and NRF2 induced ferroptosis more intensely. Our findings imply that FSP1 is a crucial suppressor of ferroptosis independent of NRF2 and that synergistically targeting both FSP1 and NRF2 may be a promising strategy for overcoming ferroptosis resistance in cancer.
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- 2023
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15. CYB5R3 functions as a tumor suppressor by inducing ER stress-mediated apoptosis of lung cancer cells via PERK-ATF4 and IRE1α-JNK pathway
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Misun Won, Joo-Young Im, Soo Jin Kim, Jong-Lyul Park, Tae-Hee Han, Woo-il Kim, Inhyub Kim, Bomin Ko, So-Young Chun, Mi-Jung Kang, Bo-Kyung Kim, Sol A Jeon, Seon-Kyu Kim, Incheol Ryu, Seon-Young Kim, Inah Hwang, and Hyun Seung Ban
- Abstract
Cytochrome b5 reductase 3 (CYB5R3) is involved in various cellular metabolic processes, including fatty acid synthesis and drug metabolism. However, the role of CYB5R3 in cancer development remains poorly understood. Here, we show that CYB5R3 expression is downregulated in human lung cancer cell lines and tissues. Adenoviral overexpression of CYB5R3 suppresses lung cancer cell growth in vitro and in vivo. However, CYB5R3 deficiency promotes tumorigenesis and metastasis in mouse models. Transcriptome analysis revealed that apoptosis- and endoplasmic reticulum (ER) stress-related genes are upregulated in CYB5R3-overexpressing lung cancer cells. Metabolomics analysis revealed that CYB5R3 overexpression increased the production of NAD+ and oxidized glutathione (GSSG). Ectopic CYB5R3 is mainly localized in the ER, where CYB5R3-dependent ER stress is induced by activating protein kinase RNA-like ER kinase (PERK) and inositol-requiring enzyme 1 alpha (IRE1α). Moreover, NAD+ activates poly (ADP-ribose) polymerase16 (PARP16), an ER-resident protein, to promote ADP-ribosylation of PERK and IRE1α and induce ER stress. In addition, CYB5R3 induces the generation of reactive oxygen species and caspase-9-dependent-intrinsic cell death. Our findings highlight the significance of CYB5R3 as a tumor suppressor for the development of CYB5R3-based therapeutics for lung cancer.
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- 2023
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16. Advances in Solution‐Processed OLEDs and their Prospects for Use in Displays
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Joo Yoon Woo, Min‐Ho Park, Su‐Hun Jeong, Young‐Hoon Kim, Byungjae Kim, Tae‐Woo Lee, and Tae‐Hee Han
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Mechanics of Materials ,Mechanical Engineering ,General Materials Science - Abstract
This review outlines problems and progress in development of solution-processed organic light-emitting diodes (SOLEDs) in industry and academia. Solution processing has several advantages such as low consumption of materials, low-cost processing, and large-area manufacturing. However, use of a solution process entails complications, such the needs for solvent resistivity and solution-processable materials, and yields SOLEDs that have limited luminous efficiency, severe roll-off characteristics, and short lifetime compared to OLEDs fabricated using thermal evaporation. These demerits impede production of practical SOLED displays. This review outlines the industrial demands for commercial SOLEDs and the current status of SOLED development in industries and academia, and presents research guidelines for development of SOLEDs that have high efficiency, long lifetime, good processability to achieve commercialization. This article is protected by copyright. All rights reserved.
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- 2023
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17. Sub-Second Joule-Heated RuO2-Decorated Nitrogen- and Sulfur-Doped Graphene Fibers for Flexible Fiber-type Supercapacitors
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Sung Hyun Noh, Hak Bong Lee, Kyong Sub Lee, Hyeonhoo Lee, and Tae Hee Han
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General Materials Science - Published
- 2022
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18. Elaborating Nitrogen and Oxygen Dopants Configurations within Graphene Electrocatalysts for Two-Electron Oxygen Reduction
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Ki Hwan Koh, Yu Joong Kim, Amir Hassan Bagherzadeh Mostaghim, Samira Siahrostami, Tae Hee Han, and Zheng Chen
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General Chemical Engineering ,Biomedical Engineering ,General Materials Science - Published
- 2022
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19. On-the-Fly Lowering Engine: Offloading Data Layout Conversion for Convolutional Neural Networks
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Mingu Kang, Sangmin Hyun, Tae Hee Han, Jungrae Kim, and Seokin Hong
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General Computer Science ,General Engineering ,General Materials Science ,Electrical and Electronic Engineering - Published
- 2022
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20. Directed Charge Boosting by Polyelectrolytes Nanorods on a Graphene Oxide Membrane for High-Performance Blue Energy Harvesting
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Ki Hyun Lee, Hyeonhoo Lee, Woojae Jeong, and Tae Hee Han
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- 2023
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21. Microglial activation induced by LPS mediates excitation of neurons in the hypothalamic paraventricular nucleus projecting to the rostral ventrolateral medulla
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Tae Hee Han, Heow Won Lee, Eun A Kang, Min Seok Song, So Yeong Lee, and Pan Dong Ryu
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endocrine system ,Neuronal activity ,PVN-RVLM ,nervous system ,Microglial activation ,General Medicine ,Sympathetic outflow ,GABAergic transmission ,Molecular Biology ,Biochemistry ,hormones, hormone substitutes, and hormone antagonists ,Article - Abstract
Microglia are known to be activated in the hypothalamic para-ventricular nucleus (PVN) of rats with cardiovascular diseases. However, the exact role of microglial activation in the plasticity of presympathetic PVN neurons associated with the modulation of sympathetic outflow remains poorly investigated. In this study, we analyzed the direct link between microglial activation and spontaneous firing rate along with the underlying synaptic mechanisms in PVN neurons projecting to the rostral ventrolateral medulla (RVLM). Systemic injection of LPS induced microglial activation in the PVN, increased the frequency of spontaneous firing activity of PVN-RVLM neurons, reduced GABAergic inputs into these neurons, and increased plasma NE levels and heart rate. Systemic minocycline injection blocked all the observed LPS-induced effects. Our results indicate that LPS increases the firing rate and decreases GABAergic transmission in PVN-RVLM neurons associated with sympathetic outflow and the alteration is largely attributed to the activation of microglia. Our findings provide some insights into the role of microglial activation in regulating the activity of PVN-RVLM neurons associated with modulation of sympathetic outflow in cardiovascular diseases.
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- 2021
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22. Improving Cache Locality in Processing-in-Memory Accelerator for Parallel Graph Processing
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Tae Hee Han and Hessa Alshamsi
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Computer science ,Graph (abstract data type) ,Parallel computing ,Cache locality - Published
- 2021
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23. Comparison of the strength of various disposable videolaryngoscope blades
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Jongbong Choi, Yeongtak Song, Yongil Cho, Heekyung Lee, Tae Ho Lim, and Tae Hee Han
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Orthodontics ,Anesthesiology and Pain Medicine ,business.industry ,Anesthesia ,Fracture test ,Medicine ,Endotracheal intubation ,General Medicine ,business ,Foreign Body Ingestion - Abstract
Breaking of disposable blades during emergency endotracheal intubation has been reported. Breakage can cause serious injury and foreign body ingestion. We aimed to measure and analyze the strength characteristics of different disposable videolaryngoscope blades with the application of an upward-lifting force. We measured the strength of four disposable videolaryngoscope blades (C-Mac® S Video laryngoscope MAC #3, Glidescope GVL® 3 stat, Pentax AWS® PBlade TL type, and King Vision® aBlade #3) using the fracture test. The strength of 12 samples of each type of disposable videolaryngoscope blade was measured using an Instron 5,966 tensile tester by applying an upward-lifting force. After the fracture test using C-Mac, Glidescope GVL, Pentax AWS, and King Vision, the number of deformed blades were 0, 12, 3, and 7, respectively, and the number of broken blades were 12, 0, 9, and 5, respectively. The mean (standard deviation) maximum force strengths of Pentax AWS, C-Mac, King Vision, and Glidescope GVL blades were 408.4 (27.4) N, 325.8 (26.5) N, 291.8 (39.3) N, and 262.7 (3.8) N, respectively (P < 0.001). Clinicians should be aware of the varied strength characteristics of the four types of disposable videolaryngoscope blades when they are used in endotracheal intubation.
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- 2021
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24. Fault Current Limiting Operations of Three-Phase Transformer Type SFCL Using Two Common Connection Points Between Secondary Windings
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Seok-Cheol Ko, Sung-Hun Lim, and Tae-Hee Han
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Materials science ,business.industry ,Joule ,Structural engineering ,Condensed Matter Physics ,Fault (power engineering) ,01 natural sciences ,Inductive coupling ,Electronic, Optical and Magnetic Materials ,law.invention ,Power (physics) ,Magnetic core ,Electromagnetic coil ,law ,0103 physical sciences ,Transient (oscillation) ,Electrical and Electronic Engineering ,010306 general physics ,Transformer ,business - Abstract
Three-phase transformer type superconducting fault current limiter (SFCL) using two common connection points between secondary windings, which consisted of three-phase transformer windings wound on three legs of E-I iron core and two/three superconducting modules (SCMs), were suggested and its fault current limiting operations according to ground-fault types were analyzed. To verify the effective operation of the three-phase transformer type SFCL using two common connection points between secondary windings, the unsymmetrical ground and the symmetrical ground faults were applied into three-phase power simulated system with the suggested SFCL. For the comparison, the ground faults were generated into three-phase transformer type SFCL with two/three SCMs. Through analysis on the test results, the SFCL with two SCMs was confirmed to have no different fault current limiting operation from the SFCL with three SCMs. The structure of E-I iron core with three magnetically coupled legs and the constitution of three secondary windings with two common connection points were analyzed to be contributed to the same fault current limiting operation. Furthermore, the power consumption and the joule energy of the SCMs comprising both the SFCL with two SCMs and the SFCL with three SCMs during the fault period had shown to be almost the same except for the transient period due to the quench time difference in case of the single-line ground fault.
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- 2021
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25. Microstructure-Controlled Polyacrylonitrile/Graphene Fibers over 1 Gigapascal Strength
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Hwansoo Shin, Tae Hee Han, Ki Hwan Koh, Wonsik Eom, Woojae Jeong, and Sang Hoon Lee
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Materials science ,Graphene ,Carbonization ,General Engineering ,Polyacrylonitrile ,Oxide ,General Physics and Astronomy ,Microstructure ,law.invention ,chemistry.chemical_compound ,chemistry ,law ,Ultimate tensile strength ,General Materials Science ,Fiber ,Crystallite ,Composite material - Abstract
Controlling the microstructures in fibers, such as crystalline structures and microvoids, is a crucial challenge for the development of mechanically strong graphene fibers (GFs). To date, although GFs graphitized at high temperatures have exhibited high tensile strength, GFs still have limited the ultimate mechanical strength owing to the presence due to the structural defects, including the imperfect alignment of graphitic crystallites and the presence of microsized voids. In this study, we significantly enhanced the mechanical strength of GF by controlling microstructures of fibers. GF was hybridized by incorporating polyacrylonitrile (PAN) in the graphene oxide (GO) dope solution. In addition, we controlled the orientation of the inner structure by applying a tensile force at 800 °C. The results suggest that PAN can act as a binder for graphene sheets and can facilitate the rearrangement of the fiber's microstructure. PAN was directionally carbonized between graphene sheets due to the catalytic effect of graphene. The resulting hybrid GFs successfully displayed a high strength of 1.10 GPa without undergoing graphitization at extremely high temperatures. We believe that controlling the alignment of nanoassembled structure is an efficient strategy for achieving the inherent performance characteristics of graphene at the level of multidimensional structures including films and fibers.
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- 2021
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26. Elucidation and modulation of active sites in holey graphene electrocatalysts for <scp> H 2 O 2 </scp> production
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Ki Hwan Koh, Amir Hassan Bagherzadeh Mostaghimi, Qiaowan Chang, Yu Joong Kim, Samira Siahrostami, Tae Hee Han, and Zheng Chen
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Chemistry (miscellaneous) ,Materials Science (miscellaneous) ,Physical and Theoretical Chemistry - Published
- 2022
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27. Metabolic Engineering of Escherichia coli
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Zi Wei Luo, Sang Yup Lee, Tae Hee Han, Cindy Pricilia Surya Prabowo, Seon Young Park, So Young Choi, Yoojin Choi, Tong Un Chae, Jong An Lee, Dongsoo Yang, Jung Ho Ahn, Jiyong Kim, and Hanwen Xu
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Metabolic engineering ,Biochemistry ,Chemistry ,Commodity chemicals ,law ,medicine ,Recombinant DNA ,medicine.disease_cause ,Escherichia coli ,Speciality chemicals ,law.invention - Published
- 2021
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28. Photonic split-second induced mesoporous TiO2-Graphene architectures for efficient sodium-ion batteries
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Hwansoo Shin, Dong-Won Kim, Swapnil B. Ambade, Ganesh Kumar Veerasubramani, Tae Hee Han, Rohan B. Ambade, Wonsik Eom, Young Beom Kim, and Maria Christy
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Materials science ,Nanocomposite ,Graphene ,Oxide ,Nanotechnology ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrochemistry ,01 natural sciences ,Capacitance ,Energy storage ,0104 chemical sciences ,law.invention ,Anode ,chemistry.chemical_compound ,chemistry ,law ,General Materials Science ,0210 nano-technology ,Mesoporous material - Abstract
Rechargeable sodium-ion batteries (SIBs) have received significant attention as a promising alternative to traditional lithium-ion counterparts for large-scale energy storage applications owing to the low cost and abundance of sodium resources. Herein, we demonstrate the photonic irradiated mesoporous reduced graphene oxide (rGO)-TiO2 nanocomposite architectures using environmentally benign, ultrafast split-second (millisecond) intense pulsed light (IPL) process at room temperature. The photonic IPL irradiation spontaneously triggers the deoxygenation of graphene oxide (GO) and the simultaneous structural engineering of TiO2 nanocomposites. The precisely controlled IPL irradiation (energy density of 10 J cm−2) exhibits excellent conductivity, high surface area, and outstanding electrochemical performance as a green anode material for SIBs. The photonic IPL irradiated rGO-TiO2 nanocomposite delivers a high reversible capacity of 244 mAh g−1 at 0.1 Ag-1, a high rate performance of 112 mAh g−1 at 1 Ag-1, and high cycling stability compared to pristine GO-TiO2 and conventional furnace annealed rGO-TiO2 (FH-rGO-TiO2) nanocomposites. The detailed electrochemical analysis suggests that the improved capacitance contribution results from the fast kinetics of the IPL irradiated rGO-TiO2 nanocomposite anode. This work provides new insight into the fabrication of versatile, cost-effective techniques for developing advanced electrode materials for energy applications.
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- 2021
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29. Highly Electroconductive and Mechanically Strong Ti3C2Tx MXene Fibers Using a Deformable MXene Gel
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Hwansoo Shin, Woojae Jeong, Ki Hyun Lee, Tae Hee Han, Wonsik Eom, and Dong Jun Kang
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Materials science ,Hydrogen bond ,General Engineering ,General Physics and Astronomy ,Modulus ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrostatics ,01 natural sciences ,0104 chemical sciences ,symbols.namesake ,Colloid ,Electrical resistivity and conductivity ,Self-healing hydrogels ,symbols ,General Materials Science ,Composite material ,van der Waals force ,0210 nano-technology ,Spinning - Abstract
Self-assembly of two-dimensional MXene sheets is used in various fields to create multiscale structures due to their electrical, mechanical, and chemical properties. In principle, MXene nanosheets are assembled by molecular interactions, including hydrogen bonds, electrostatic interactions, and van der Waals forces. This study describes how MXene colloid nanosheets can form self-supporting MXene hydrogels. Three-dimensional network structures of MXene gels are strengthened by reinforced electrostatic interactions between nanosheets. Stable gel networks are beneficial for fabricating highly aligned fibers because MXene gel can endure structural deformation. During wet spinning of highly concentrated MXene colloids in a coagulation bath, MXene sheets can be transformed into perfectly aligned fibers under a mechanical drawing force. Oriented MXene fibers exhibit a 1.5-fold increase in electrical conductivity (12 504 S cm-1) and Young's modulus (122 GPa) compared with other fibers. The oriented MXene fibers are expected to have widespread applications, including electrical wiring and signal transmission.
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- 2021
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30. Engineering electrodes and metal halide perovskite materials for flexible/stretchable perovskite solar cells and light-emitting diodes
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Tae Hee Han, Kyung-Geun Lim, and Tae-Woo Lee
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Conductive polymer ,Materials science ,Renewable Energy, Sustainability and the Environment ,Halide ,Nanotechnology ,Pollution ,law.invention ,Metal ,Organic semiconductor ,Nuclear Energy and Engineering ,law ,visual_art ,Electrode ,visual_art.visual_art_medium ,Environmental Chemistry ,Electronics ,Perovskite (structure) ,Light-emitting diode - Abstract
Organic–inorganic hybrid metal halide perovskites have excellent optoelectronic properties and are soft and resilient; therefore, they are appropriate for use in flexible and stretchable electronic devices. Commercialization of these perovskite optoelectronics requires development of flexible and stretchable electrodes that are compatible with perovskite optoelectronic properties. Compared to optoelectronic organic semiconductors, exploitation of the advantages of perovskite optoelectronics requires new perspectives in flexible and stretchable electrodes. Here we describe techniques to control the optical, electrical, and mechanical properties of metal halide perovskites that must be suitable for use in flexible and stretchable applications, and then discuss the most convincing candidates for flexible and stretchable electrode materials such as conducting polymers, low-dimensional carbon materials, and structured metals and their composites.
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- 2021
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31. Sub-Second Joule-Heated RuO
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Sung Hyun, Noh, Hak Bong, Lee, Kyong Sub, Lee, Hyeonhoo, Lee, and Tae Hee, Han
- Abstract
Graphene-based fiber-shaped supercapacitors (FSSCs) have received considerable attention as potential wearable energy storage devices owing to their simple operating mechanism, flexibility, and long-term stability. To date, energy storage capacities of supercapacitors have been significantly improved via strategies such as heteroatom doping and the incorporation of pseudocapacitive metal oxides. Herein, we develop a novel and scalable direct-hybridization method that combines heteroatom doping and metal oxide hybridization for the fabrication of high-performance FSSCs. Using porous and highly conductive nitrogen and sulfur co-doped graphene fibers (NS-GFs) as self-heating units, we successfully convert ruthenium hydroxide anchored to the surface into ruthenium oxide nanoparticles after programmed sub-second electrothermal annealing without structural damage of the fibers. The resulting fibers show an increased gravimetric capacitance of 68.88 F g
- Published
- 2022
32. System-Level Signal Analysis Methodology for Optical Network-on-Chip Using Linear Model-Based Characterization
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Yong Wook Kim, Tae Hee Han, and Min Su Kim
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Signal processing ,Silicon photonics ,Computer science ,business.industry ,Bandwidth (signal processing) ,Linear system ,Physics::Optics ,Computer Graphics and Computer-Aided Design ,Resonator ,Network on a chip ,Interference (communication) ,Electronic engineering ,Electrical and Electronic Engineering ,Photonics ,business ,Software - Abstract
State-of-the-art silicon photonics technology has demonstrated its potential use in all required building blocks for ultrahigh bandwidth on-chip optical links. However, a robust system-level abstraction model reflecting the properties of optical devices has not been well established. We propose a linear optical device model (LODM) for silicon photonic devices and an associated computation method of optical signal propagation (CMOP) in an optical network-on-chip (ONoC). The CMOP manipulates the optical signal routing paths according to the topology, router configuration, and routing algorithm of the given ONoC architecture; thus, it allows the transformed information to be adaptable in an LODM to facilitate simplified analysis. Furthermore, we construct a linear system model of a microring resonator (MR) to reduce the computation complexities caused by its resonance structure. By using the CMOP, we accelerate the system-level analysis of optical signal propagation in ONoCs, reflecting the propagation loss, interference, and phase shift with close accuracy to analog and mixed-signal extensions (AMS) environments. The evaluation results show that the computation speeds up by three orders of magnitude with 1.57% error in accuracy when compared to the AMS environments.
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- 2020
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33. Magnetization Characteristics Due to Fault Angle of Transformer Type SFCL with Two Isolated Secondary Windings
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Tae-Hee Han, Seok-Cheol Ko, and Sung-Hun Lim
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Materials science ,020209 energy ,02 engineering and technology ,Mechanics ,Energy consumption ,Fault (power engineering) ,01 natural sciences ,Flux linkage ,law.invention ,Computer Science::Hardware Architecture ,Magnetization ,Current limiting ,law ,Electromagnetic coil ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,Electrical and Electronic Engineering ,010306 general physics ,Transformer ,Computer Science::Operating Systems ,Computer Science::Distributed, Parallel, and Cluster Computing ,Voltage - Abstract
In this paper, a transformer type superconducting fault current limiter (SFCL) with two isolated secondary windings was fabricated to increase the current limiting capacity. As the magnetization current increased due to the large transient fault current immediately after the fault, the magnetization force variation, the operating range of the flux linkage, and the voltage region variation were compared at fault angles of 0° and 90°, respectively. The short-circuit test analyzed the current limiting operation, power consumption, and energy consumption characteristics according to the fault angle immediately after the fault occurrence. The results showed that the fault angle of 0° could limit the fault current much more than the fault angle of 90°. In addition, it was confirmed that the magnetization force variation, the operating range of the flux linkage, and the voltage induced in the primary winding were all much larger at the fault angle of 0° than at the fault angle of 90°.
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- 2020
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34. Selective Disruption of Synaptic BMP Signaling by a Smad Mutation Adjacent to the Highly Conserved H2 Helix
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Mihaela Serpe, Tae Hee Han, Tho Huu Nguyen, and Stuart J. Newfeld
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Developmental and Behavioral Genetics ,BMP signaling ,animal structures ,Mad alleles ,Amino Acid Motifs ,Neuromuscular Junction ,Drosophila NMJ ,SMAD ,Investigations ,Biology ,medicine.disease_cause ,Bone morphogenetic protein ,Cell junction ,03 medical and health sciences ,0302 clinical medicine ,Postsynaptic potential ,medicine ,Genetics ,Animals ,Drosophila Proteins ,Conserved Sequence ,030304 developmental biology ,Mutation ,0303 health sciences ,Chemistry ,Point mutation ,Synaptic Potentials ,Phenotype ,Cell biology ,DNA-Binding Proteins ,Drosophila melanogaster ,Bone Morphogenetic Proteins ,Phosphorylation ,Signal transduction ,030217 neurology & neurosurgery ,Signal Transduction ,Transcription Factors - Abstract
Bone morphogenetic proteins (BMPs) shape normal development and function via canonical and non-canonical signaling pathways. When activating the canonical pathway, BMPs initiate signaling by binding to transmembrane receptors that phosphorylate pathway effectors, the Smad proteins, inducing their translocation into the nucleus and thus regulation of target genes. Phosphorylated Smads also accumulate at cellular junctions, but this non-canonical signaling modality remains less defined. We have recently reported that phosphorylated Smad (pMad inDrosophila) accumulates at synaptic junctions in complexes with genetically distinct composition and regulation. Here we examined a wide collection ofDrosophila Madalleles and searched for molecular features relevant to pMad accumulation at synaptic junctions. We found that strongMadalleles generally disrupt both synaptic and nuclear pMad accumulation, whereas moderateMadalleles have a wider range of phenotypes and could selectively impact different BMP signaling modalities. Interestingly, synaptic pMad appeared more sensitive to net reduction in Mad levels than nuclear pMad. Importantly, a previously uncharacterized allele,Mad8, showed markedly reduced synaptic pMad levels but only moderately diminished nuclear pMad signals. The postsynaptic composition and electrophysiological properties ofMad8NMJs were similarly altered. Using biochemical approaches, we examined how single point mutations such as S359L, present inMad8, could influence the Mad-receptor interface and we identified a key molecular determinant, the H2 helix. Our study highlights the biological relevance of the Smad-dependent, non-canonical BMP signaling and uncovers a highly conserved structural feature of Smads, critical for normal development and function.
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- 2020
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35. Characterizing the Efficiency of Perovskite Solar Cells and Light-Emitting Diodes
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Tae Hee Han, Su Hun Jeong, Kai Zhu, Matthew O. Reese, Jaehyeok Park, Fei Zhang, Joo Sung Kim, Tae-Woo Lee, Seunghyup Yoo, and Min-Ho Park
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Computer science ,Energy conversion efficiency ,Perovskite solar cell ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Engineering physics ,0104 chemical sciences ,law.invention ,General Energy ,Gamut ,law ,High color ,Quantum efficiency ,0210 nano-technology ,Perovskite (structure) ,Light-emitting diode ,Diode - Abstract
Summary Metal halide perovskites (MHPs) are being widely studied as a light-absorber for high-efficiency solar cells. With efforts being made throughout the globe, the power conversion efficiency of MHP solar cells has recently soared up to 25.2%. MHPs are now being spotlighted as a next-generation light-emitter as well. Their high color purity and solution-processability are of particular interest for display applications, which in general benefit from wide color gamut and low-cost high-resolution subpixel patterning. For this reason, research activities on perovskite light-emitting diodes (LEDs) are rapidly growing, and their external quantum efficiencies have been dramatically improved to over 20%. As more and more research groups with different backgrounds are working on these perovskite optoelectronic devices, the demand is growing for standard methods for accurate efficiency measurement that can be agreed upon across the disciplines and, at the same time, can be realized easily in the lab environment with due diligence. Herein, optoelectronic characterization methods are revisited from the viewpoint of MHP solar cells and LEDs. General efficiency measurement practices are first reviewed, common sources of errors are introduced, and guidelines for avoiding or minimizing those errors are then suggested to help researchers in fields develop the best measurement practice.
- Published
- 2020
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36. Ultrafast photo-annealed carbon-coated SiO2 sphere electrodes for NO2 gas sensing
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Hojae Lee, Hak Bong Lee, Young Beom Kim, Sung Hyun Noh, Tae Hee Han, and Sang Hoon Lee
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chemistry.chemical_classification ,Materials science ,Laser printing ,Nanotechnology ,02 engineering and technology ,General Chemistry ,Polymer ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Laser ,01 natural sciences ,0104 chemical sciences ,law.invention ,chemistry ,law ,Printed electronics ,Electrode ,Screen printing ,Polymer substrate ,General Materials Science ,Electronics ,0210 nano-technology - Abstract
There is great interest in carbon-based printed electronics as a promising technology to achieve lighter, thinner and flexible electronic devices at low-costs. Despite the surge of enthusiasm in this area, research advances in printed electronics are not yet able to realize diverse carbon structures yet. This is due to the limitations in conventional solution-based printing methods (e.g., inkjet printing, roll-to-roll, screen printing). Processes such as polymer phase-inversion offer one possibility but a much faster and efficient method should be devised for reliable production. Here, we demonstrate laser printing combined with intense pulsed-light (IPL) annealing as a novel and efficient technique which can form inter-connected carbon spheres electrode on flexible polymer substrate. Our observations show that the printed patterns from a laser printer consist of a solid-state polymer matrix with inorganic nanoparticles randomly embedded inside. Through ultrafast (5 ms) IPL treatment, core/shell type nanosphere arrays of carbon-coated SiO2 were successfully fabricated, which could be used as a functional platform for highly selective NO2 gas sensing.
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- 2020
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37. Timing Error Recovery Technique in a Single Cycle for Network-on-Chip Router
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Min Gu Kang, Ju Yeon Kang, Tae Hee Han, and Jo Eun Lee
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Router ,Timing error ,Network on a chip ,business.industry ,Computer science ,business ,Computer hardware ,Single cycle - Published
- 2020
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38. Super-Expansion of Assembled Reduced Graphene Oxide Interlayers by Segregation of Al Nanoparticle Pillars for High-Capacity Na-Ion Battery Anodes
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Tae Hee Han, Seong Ji Pyo, Wonsik Eom, Won-Hee Ryu, You Jin Kim, and Sang Hoon Lee
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Battery (electricity) ,Materials science ,Graphene ,Oxide ,Nanoparticle ,Graphite oxide ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Anode ,law.invention ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Electrochemical reaction mechanism ,law ,General Materials Science ,Graphite ,0210 nano-technology - Abstract
The applicability of Na-ion batteries is contingent on breakthroughs in alternative electrode materials that have high capacities and which are economically viable. Unfortunately, conventional graphite anodes for Li-ion battery systems do not allow Na-ion accommodation into their interlayer space owing to the large ionic radius and low stabilizing energy of Na in graphite. Here, we suggest a promising strategy for significantly increasing Na capacity by expanding the axial slab space of graphite. We successfully synthesized reconstructed graphite materials via self-assembly of negative graphite oxide (GO) flakes and Al cation (positive) pillars and by subsequent chemical reaction of the obtained Al-GO materials. Al pillars, atomically distributed in graphite interlayers, can extend the slab space by up to ∼7 Å, which is a 2-fold interlayer distance of pristine graphite. An exceptionally high capacity of 780 mAh/g is demonstrated for reconstructed graphite anodes with Al pillars, compared with rGO materials (210 mAh/g). We investigated the electrochemical reaction mechanism and structural changes associated with discharge and charge to emphasize the benefit of using reconstructed graphite as anodes in Na-ion batteries. Our strategy of modifying the interlayer distance by introducing metallic pillars between the layers can help address the low capacity of carbonaceous anodes.
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- 2020
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39. Room-Temperature, Highly Durable Ti3C2Tx MXene/Graphene Hybrid Fibers for NH3 Gas Sensing
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Sang Hoon Lee, Wonsik Eom, Hwansoo Shin, Tae Hee Han, Hyoun Woo Kim, Jae Hoon Bang, and Rohan B. Ambade
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Imagination ,Chemical substance ,Materials science ,Graphene ,business.industry ,media_common.quotation_subject ,Wearable computer ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,law.invention ,law ,General Materials Science ,0210 nano-technology ,Science, technology and society ,business ,Hybrid material ,Spinning ,Wearable technology ,media_common - Abstract
Graphene-based fibers (GFs) have aroused enormous interest in portable, wearable electronics because of their excellent mechanical flexibility, electrical conductivity, and weavability, which make them advantageous for wearable electronic devices. Herein, we report the development of metal binder-free Ti3C2Tx MXene/graphene hybrid fibers by a scalable wet-spinning process. These hybrid fibers exhibit excellent mechanical and electrical properties for applications in flexible wearable gas sensors. The synergistic effects of electronic properties and gas-adsorption capabilities of MXene/graphene allow the created fibers to show high NH3 gas sensitivity at room temperature. The hybrid fibers exhibited significantly improved NH3 sensing response (ΔR/R0 = 6.77%) compared with individual MXene and graphene. The hybrid fibers also showed excellent mechanical flexibility with a minimal fluctuation of resistance of ±0.2% and low noise resistance even after bending over 2000 cycles, enabling gas sensing during deformation. Furthermore, flexible MXene/graphene hybrid fibers were woven into a lab coat, demonstrating their high potential for wearable devices. We envisage that these exciting features of 2D hybrid materials will provide a novel pathway for designing next-generation portable wearable gas sensors.
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- 2020
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40. Graphene Foam Cantilever Produced via Simultaneous Foaming and Doping Effect of an Organic Coagulant
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Jae Yong Cho, Wonsik Eom, Sung Hyun Noh, Dong Jun Kang, Hak Bong Lee, Hun Park, Tae Hee Han, and Tae Hyun Sung
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Cantilever ,Materials science ,Graphene ,Graphene foam ,Doping ,Foaming agent ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,law.invention ,law ,General Materials Science ,Self-assembly ,Resilience (materials science) ,Composite material ,0210 nano-technology - Abstract
Inspired by the role of cellular structures, which give three-dimensional robustness to graphene structures, a new type of graphene cantilever with mechanical resilience is introduced. Here, NH4SCN...
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- 2020
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41. Extended Worst-Case OSNR Searching Algorithm for Optical Network-on-Chip Using a Semi-Greedy Heuristic With Adaptive Scan Range
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Yong Wook Kim, Tae Hee Han, and Jae Hoon Lee
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worst-case searching ,General Computer Science ,Optical network-on-chip ,Computer science ,OSNR ,secondary effect of crosstalk noise ,General Engineering ,Range (mathematics) ,Network on a chip ,Search algorithm ,semi-greedy heuristic ,General Materials Science ,lcsh:Electrical engineering. Electronics. Nuclear engineering ,Greedy algorithm ,lcsh:TK1-9971 ,Algorithm - Abstract
The advances in silicon photonics technology have facilitated the realization of optical network-on-chips (ONoCs) to cope with the physical limitations of metal interconnections in traditional CMOS integrated circuits. As the performance and reliability of optical links are adversely affected by insertion losses and crosstalk, which inevitably occur during the propagation of optical signals, optimizing the power of a laser source requires a sophisticated analysis of the optical signal-to-noise ratio (OSNR). Calculating the worst-case OSNR for all possible communication links in an ONoC is an NP-hard problem even under the assumption of a single-wavelength laser source. Moreover, when expanding the design space by accommodating wavelength-division multiplexing (WDM), semiconductor optical amplifier (SOA), diverse topologies, and the associated router architectures, the computational complexity becomes excessive. Therefore, in this study, we propose an extended worst-case OSNR search algorithm (EWOSA) that significantly reduces the computational burden through a preprocessing algorithm that reduces the number of candidate paths when the combined effect of the insertion loss and crosstalk on the OSNR is considered. Simulation results demonstrate that the EWOSA can identify approximately 0.18 dB lower worst-case OSNR than the existing formal worst-case analysis method in 8 × 8 mesh-based ONoC, and this improvement in OSNR accuracy becomes more apparent (up to 4.81 dB) when SOAs are deployed in ONoCs. Furthermore, the EWOSA can be used for OSNR optimization, owing to its rapid analysis speed and generality.
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- 2020
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42. The E3 ubiquitin ligase adaptor Tango10 links the core circadian clock to neuropeptide and behavioral rhythms
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Casey O. Diekman, Tomas Andreani, Bridget C. Lear, William L. Kath, Ravi Allada, Jack Curran, Eric C. Johnson, Chunghun Lim, Tae Hee Han, Jongbin Lee, and Matthew J. Moye
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Proteomics ,Timeless ,Ubiquitin-Protein Ligases ,Circadian clock ,Mutant ,Neuropeptide ,ubiquitin ligase ,potassium current ,Circadian Clocks ,Animals ,Drosophila Proteins ,Circadian rhythm ,Neurons ,Multidisciplinary ,biology ,Aryl Hydrocarbon Receptor Nuclear Translocator ,Neuropeptides ,neuronal output ,Biological Sciences ,Cullin Proteins ,Ubiquitin ligase ,Cell biology ,CLOCK ,nervous system ,circadian rhythms ,biology.protein ,Drosophila ,Sleep ,Cullin ,Neuroscience - Abstract
Significance In animals, the control of daily sleep–wake rhythms is mediated by discrete circadian clock neurons via their rhythmic activity–dependent release of neuropeptides and neurotransmitters. Here, we describe a gene, Tango10, critical for daily behavioral rhythms. TANGO10 functions as an adaptor with its partner, the E3 ubiquitin ligase CULLIN 3, to regulate protein ubiquitination, neuronal excitability via voltage-gated potassium channels, and neuropeptide accumulation. These studies define a mechanism for control of neuronal excitability and daily rhythmicity., Circadian transcriptional timekeepers in pacemaker neurons drive profound daily rhythms in sleep and wake. Here we reveal a molecular pathway that links core transcriptional oscillators to neuronal and behavioral rhythms. Using two independent genetic screens, we identified mutants of Transport and Golgi organization 10 (Tango10) with poor behavioral rhythmicity. Tango10 expression in pacemaker neurons expressing the neuropeptide PIGMENT-DISPERSING FACTOR (PDF) is required for robust rhythms. Loss of Tango10 results in elevated PDF accumulation in nerve terminals even in mutants lacking a functional core clock. TANGO10 protein itself is rhythmically expressed in PDF terminals. Mass spectrometry of TANGO10 complexes reveals interactions with the E3 ubiquitin ligase CULLIN 3 (CUL3). CUL3 depletion phenocopies Tango10 mutant effects on PDF even in the absence of the core clock gene timeless. Patch clamp electrophysiology in Tango10 mutant neurons demonstrates elevated spontaneous firing potentially due to reduced voltage-gated Shaker-like potassium currents. We propose that Tango10/Cul3 transduces molecular oscillations from the core clock to neuropeptide release important for behavioral rhythms.
- Published
- 2021
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43. Cancer-specific cytotoxicity of pyridinium-based ionic liquids by regulating hypoxia-inducible factor-1α-centric cancer metabolism
- Author
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Tae-Hee Han, Jong-Dae Lee, Beom-Chan Seo, Won-Hui Jeon, Hyun-A. Yang, Seongyeong Kim, Keeok Haam, Min Kyung Park, Junhee Park, Tae-Su Han, and Hyun Seung Ban
- Subjects
Oxygen ,Health, Toxicology and Mutagenesis ,Colonic Neoplasms ,Tumor Microenvironment ,Public Health, Environmental and Occupational Health ,Humans ,Ionic Liquids ,General Medicine ,Hypoxia-Inducible Factor 1, alpha Subunit ,Hypoxia ,Pollution - Abstract
Owing to their unique properties and biological activities, ionic liquids (ILs) have attracted research interest in pharmaceutics and medicine. Hypoxia-inducible factor (HIF)- 1α is an attractive cancer drug target involved in cancer malignancy in the hypoxic tumor microenvironment. Herein, we report the inhibitory activity of ILs on the HIF-1α pathway and their mechanism of action. Substitution of a dimethylamino group on pyridinium reduced hypoxia-induced HIF-1α activation. It selectively inhibited the viability of the human colon cancer cell line HCT116, compared to that of the normal fibroblast cell line WI-38. These activities were enhanced by increasing the alkyl chain length in the pyridinium. Under hypoxic conditions, dimethylaminopyridinium reduced the accumulation of HIF-1α and its target genes without affecting the HIF1A mRNA level in cancer cells. It suppressed the oxygen consumption rate and ATP production by directly inhibiting electron transfer chain complex I, which led to enhanced intracellular oxygen content and oxygen-dependent degradation of HIF-1α under hypoxia. These results indicate that dimethylaminopyridinium suppresses the mitochondria and HIF-1α-dependent glucose metabolic pathway in hypoxic cancer cells. This study provides insights into the anticancer activity of pyridinium-based ILs through the regulation of cancer metabolism, making them promising candidates for cancer treatment.
- Published
- 2022
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44. Significantly suppressing ion migration in metal halide perovskites via trace of multivalent interstitial doping
- Author
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Anni Zhang, Yang Yang, Marc H. Weber, Jingjing Xue, Jiming Bian, Yepin Zhao, Sang-Hoon Bae, Yifang Zhou, Tianyi Huang, Shaun Tan, Minhuan Wang, Tae Hee Han, Sung-Joon Lee, Ju-Hong Lee, Dong Meng, Rui Wang, Nam-Gyu Park, Ilhan Yavuz, and Jin-Wook Lee
- Subjects
Metal ,Trace (semiology) ,Materials science ,visual_art ,Inorganic chemistry ,Doping ,Ion migration ,visual_art.visual_art_medium ,Halide - Abstract
Cations with suitable sizes to occupy an interstitial site of perovskite crystals have been widely used to inhibit ion migration and promote performance and stability of perovskite optoelectronics. However, the interstitial doping accompanies inevitable lattice strain to impair long-range ordering and stability of the crystals to cause a sacrificial trade-off. Here, we unravel the evident influence of the valence states of the interstitial cations on their efficacy to suppress the ion migration. Incorporation of a trivalent neodymium cation (Nd3+) effectively mitigates the ion migration in the perovskite lattice with significantly reduced dosage (0.08%) compared to a widely used monovalent cation dopant (Na+, 0.45%). Less but better, the prototypical perovskite solar cells incorporated with Nd3+ exhibits significantly enhanced photovoltaic performance and operational stability.
- Published
- 2021
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45. Mechanisms of Two-Electron and Four-Electron Electrochemical Oxygen Reduction Reactions at Nitrogen-Doped Reduced Graphene Oxide
- Author
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Hyo Won Kim, Alan C. Luntz, Johannes Voss, Jinkyu Lim, Tae Hee Han, Wooyul Kim, Young Hoon Cho, Vanessa J. Bukas, Sojung Park, Kyle M. Diederichsen, Ju-Young Kim, Hun Park, and Bryan D. McCloskey
- Subjects
Materials science ,010405 organic chemistry ,Graphene ,Inorganic chemistry ,Oxide ,General Chemistry ,Electron ,010402 general chemistry ,Electrocatalyst ,Electrochemistry ,01 natural sciences ,Catalysis ,Oxygen reduction ,0104 chemical sciences ,law.invention ,chemistry.chemical_compound ,chemistry ,law ,Selectivity - Abstract
Doped carbon-based systems have been extensively studied over the past decade as active electrocatalysts for both the two-electron (2e–) and four-electron (4e–) oxygen reduction reactions (ORRs). H...
- Published
- 2019
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46. Kinetically controlled low-temperature solution-processed mesoporous rutile TiO2 for high performance lithium-ion batteries
- Author
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Ki Hwan Koh, Chong Min Koo, Sung Hyun Noh, Rohan B. Ambade, Seong Hun Kim, Swapnil B. Ambade, Wonsik Eom, and Tae Hee Han
- Subjects
Materials science ,General Chemical Engineering ,chemistry.chemical_element ,02 engineering and technology ,Crystal structure ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,chemistry ,Chemical engineering ,Rutile ,Phase (matter) ,Lithium ,Thermal stability ,0210 nano-technology ,Mesoporous material ,Solution process ,Titanium - Abstract
Solution-processed nanostructured mesoporous rutile phase titanium dioxides (TiO2) are a fascinating class of materials for energy applications owing to their remarkable properties, including thermal stability. The unique lattice structure of rutile TiO2 (R-TiO2) leads to multifaceted physicochemical properties, which influence its performances. We here report the preparation of mesoporous R-TiO2 via a simple and scalable solution process at a low temperature (
- Published
- 2019
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47. Magnetizing Characteristics of a Flux-Coupling Type SFCL With Two Magnetic Flux Paths Using Its Third Winding
- Author
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Seokcheol Ko, Tae-Hee Han, and Sung-Hun Lim
- Subjects
Coupling ,Physics ,Condensed matter physics ,Electrical and Electronic Engineering ,Type (model theory) ,Condensed Matter Physics ,Flux linkage ,Flux (metabolism) ,Magnetic flux ,Electronic, Optical and Magnetic Materials - Published
- 2019
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48. Ideal conducting polymer anode for perovskite light-emitting diodes by molecular interaction decoupling
- Author
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Kwang S. Kim, Tae Hee Han, Jung-Min Heo, Hobeom Kim, Nannan Li, Tae-Woo Lee, Yeongjun Lee, Su Hun Jeong, Min-Ho Park, Hong Kyu Seo, and Soyeong Ahn
- Subjects
Conductive polymer ,Materials science ,Renewable Energy, Sustainability and the Environment ,business.industry ,Exciton ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Anode ,law.invention ,law ,Electrical resistivity and conductivity ,Optoelectronics ,General Materials Science ,Work function ,Electrical and Electronic Engineering ,0210 nano-technology ,business ,Decoupling (electronics) ,Light-emitting diode ,Diode - Abstract
An ideal conducting polymer anode (CPA) in organic and perovskite light-emitting diodes (LEDs) requires high electrical conductivity κ, high work function WF, and prevention of exciton quenching between an anode and an overlying emitting layer. However, increasing the κ and WF at the same time has been a very challenging unsolved issue due to their trade-off relationship: previous approaches to increase the WF have reduced the films’ κ and vice versa. Therefore, delicate molecular scale control of the conducting polymer compositions are required to solve this fundamental issue. Here, we introduce an effective molecular scale control strategy to decouple the WF with κ in a CPA while maintaining blocking capability of exciton quenching. This change resulted in a high current efficiency up to 52.86 cd A−1 (10.93% ph el−1) in green polycrystalline perovskite LEDs. Our results provide a significant clue to develop effective CPAs for highly-efficient organic and perovskite LEDs.
- Published
- 2019
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- View/download PDF
49. Reconstruction of context-specific genome-scale metabolic models using multiomics data to study metabolic rewiring
- Author
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Changdai Gu, Sang Yup Lee, Jae Yong Ryu, Tae Hee Han, and Jae Sung Cho
- Subjects
0303 health sciences ,endocrine system diseases ,Applied Mathematics ,Genome scale ,Computational biology ,Biology ,computer.software_genre ,Precision medicine ,General Biochemistry, Genetics and Molecular Biology ,Computer Science Applications ,Omics data ,03 medical and health sciences ,0302 clinical medicine ,Modeling and Simulation ,Drug Discovery ,Context specific ,computer ,Reprogramming ,030217 neurology & neurosurgery ,030304 developmental biology ,Data integration - Abstract
Metabolic rewiring or reprogramming is the alteration of metabolism in living organisms, leading to disordered states aberrant from homeostasis. As large amounts of omics data become available, complex mechanisms leading to or driven by metabolic rewiring of cells can be better understood using reconstructed context-specific genome-scale metabolic models (GEMs). Here, we review recent advances in reconstructing context-specific GEMs for studying metabolic rewiring of human cells or tissues, from generic GEMs and omics databases to multiomics data integration methods. Also, we review recent studies that use context-specific GEMs to obtain insights such as identifying key regulators or therapeutic targets. Analyses of recent trends indicate the importance of integrating context-specific GEMs with multiscale networks for understanding metabolic diseases and advancing precision medicine.
- Published
- 2019
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50. Carbon Defect Characterization of Nitrogen-Doped Reduced Graphene Oxide Electrocatalysts for the Two-Electron Oxygen Reduction Reaction
- Author
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Hee Wook Yoon, Ho Bum Park, Tae Hoon Lee, Hun Park, Bryan D. McCloskey, Tae Hee Han, Hyo Won Kim, Jae Eun Shin, Ji Soo Roh, Liang Zhang, Vanessa J. Bukas, Young Hoon Cho, and Jinghua Guo
- Subjects
Materials science ,Graphene ,General Chemical Engineering ,Oxide ,chemistry.chemical_element ,02 engineering and technology ,General Chemistry ,Electron ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrochemistry ,01 natural sciences ,0104 chemical sciences ,Catalysis ,law.invention ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,law ,Materials Chemistry ,0210 nano-technology ,Porosity ,Hydrogen peroxide ,Carbon - Abstract
Numerous modified-carbon catalysts have been developed for the direct synthesis of hydrogen peroxide through electrochemical oxygen reduction. However, given the complex structure of most porous ca...
- Published
- 2019
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