Daegu Gyeongbuk Institute of Science and Technology
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Nonlinear Landau Fan Diagram for Graphene Electrons Exposed to a Moire Potential
Get PDFDue to Landau quantization, the conductance of two-dimensional electrons exposed to a perpendicular magnetic field exhibits oscillations that generate a fan of linear trajectories when plotted in the parameter space spanned by density and field. This fan looks identical, irrespective of the dispersion and field dependence of the Landau level energy. This is no surprise because the position of conductance minima depends solely on the level degeneracy that is linear in flux. The fractal energy spectrum that emerges within each Landau band when electrons are also exposed to a two-dimensional superlattice potential produces numerous additional oscillations, but they also create just linear fans for identical reasons. Here, we report conductance oscillations of graphene electrons exposed to a moiré potential that defy this general rule and form nonlinear trajectories in the density-field plane. We attribute this anomalous behavior to the simultaneous occupation of multiple minibands and magnetic breakdown-induced open orbits. © 2024 The Authors. Published by American Chemical Society This article is licensed under CC-BY 4.0TRUEsciescopu
종합적인 공액 고분자 변형을 통한 페로브스카이트 태양전지의 계면 결함 복원
No full textPerovskite Solar Cells; Dfects; Passivation; Polymer; Li-capturingList of Contents
Abstract i
List of contents ⅳ
List of tables ⅵ
List of figures ⅶ
Ⅰ. Introduction 1
1.1 Perovskite Solar Cells 1
1.2 Passivation Engineering 4
1.2.1 Passivation Engineering by Metal Cations 5
1.2.2 Passivation Engineering by Anions 7
1.2.3 Passivation Engineering by Ammonium Salts 8
1.2.4 Passivation Engineering by Polymer 10
1.3 Summary 12
1.4 Reference 13
Ⅱ. Synergistic Dual-Passivation Strategies for Efficient Charge Transport Perovskite
Solar Cells with Bi-Functional Polymer 19
2.1 Introduction 19
2.2 Results and Discussion 23
2.2.1 Design and Application of Ambipolar Polymer 23
2.2.2 Hole transport blended Passivation 32
2.2.3 Integration of Polymer Passivation 35
2.3 Conclusion 40
2.4 Experimental Section 41
2.4.1 Materials 41
2.4.2 Synthesis of DP 43
2.4.3 n-i-p Device Fabrication (CsFAMA perovskite) 44
2.4.4 p-i-n Device Fabrication (CsFAMA perovskite) 45
2.4.5 n-i-p Device Fabrication (FAPbI3 perovskite) 46
2.4.6 Characterization 47
2.4.7 Grazing Incidence Wide-Angle Scattering (GIWAXS) Analysis 48
2.4.8 Supplementary Note 49
2.5 Reference 53DoctordCollectio
Dynamic Offloading and CPU Clock Scaling for Edge Computing in LEO Satellite Networks
No full text저궤도 (LEO) 위성 통신은 기존 지상 네트워크의 글로벌 커버리지 구축 문제를 해결하는 좋은 방법으로 채택되고 있다. 또한 6G 서비스 시대로 나아감에 있어 복잡한 어플리케이션의 출현은 자연스럽게 장치들의 계산 부담을 증가하게 만들었고, 합리적인 컴퓨팅을 위해 오프로딩 및 엣지 컴퓨팅 기법이 활발하게 적용되고 있다. 따라서 6G 서비스의 전 지구적이고 원활한 활용을 위해, 저궤도 위성에 컴퓨팅이 가능한 서버를 설치하여 엣지 컴퓨팅을 가능하게 하는 위성 엣지 컴퓨팅 (SEC) 연구가 활발히 진행되고 있다. 다만 진행 중인 연구들은 지상 네트워크에서의 엣지 컴퓨팅 기법을 위성 네트워크로 확장만 할 뿐, 위성 네트워크의 물리적인 토폴로지 변화를 고려한 동적인 채널 상태를 합리적으로 고려하지 않고 있다. 이를 해결하기 위해 본 연구에서는 동적 채널 상태를 합리적으로 반영하는 저궤도 위성 네트워크에서의 엣지 컴퓨팅 프레임워크를 제안하고, 시스템의 전력 소모와 전파 지연 최소화를 목표로 하는 Lyapunov 최적화 기법 기반의 알고리즘을 제안한다. 제안한 SEC 시나리오에서의 시뮬레이션을 통해 알고리즘이 동적으로 변화하는 채널 상태와 요청되는 서비스에 따라 적응적으로 동작하여 기존의 통상적인 방법들에 비해 같은 처리 지연 대비 더 적은 전력을 소비함을 확인할 수 있다.
Low Earth Orbit (LEO) satellite communication is an effective solution for addressing global coverage challenges in terrestrial networks. As we enter the 6G era, the rise of complex applications has increased device computational demands, driving the adoption of techniques like offloading and Edge Computing for efficient processing. To achieve seamless global 6G service integration, active research is underway in Satellite Edge Computing (SEC). SEC involves deploying computation-capable servers on LEO satellites, enabling edge computing. However, many studies extend terrestrial Edge Computing techniques to satellite networks without adequately considering dynamic channel conditions due to physical topology changes. Our research proposes an Edge Computing framework tailored to LEO satellite networks, effectively addressing dynamic channel conditions. We introduce optimization algorithms to minimize system power consumption and propagation latency. Simulations in our proposed SEC scenario confirm our algorithm’s adaptability to changing channel conditions and service requests, resulting in lower power consumption compared to conventional methods for the same processing latency.FALSEscopuskc
Unraveling capacity recovery behavior of 78 Ah pouch cells after long-term storage for EVs: Passive anode and calendar-aged SEI effects
No full textThe unavoidable long-term storage after production can result in capacity and power fading in commercial lithium-ion batteries. Remarkably, the decreased capacity is partially and gradually recovered when the stored cells are cycled again, known as capacity recovery. However, it is challenging to analyze the capacity recovery phenomenon independently from the capacity decay during re-cycling. Moreover, the most well-known explanation for capacity recovery, the passive anode effect (PAE) is only focus on the lithium inventory inside the overhang anode site. To address these issues, the large-capacity LiNi0 . 4Co0 . 3Mn0 .3O2/graphite pouch cells stored for 4 years is used. Typically, throughout the re-cycling, the capacity is gradually recovered up to 120 cycles, and the fully recovered capacity was maintained up to 500 cycles, indicating that additional capacity decay by re-cycling was almost suppressed. Also, we clearly reveal the impact of breakdown and thinning of the calendar-aged solid electrolyte interphase (SEI) on the whole anode site influences both capacity and power recovery, not just limited to the PAE. Furthermore, by combining both the PAE and breakdown of the calendar-aged SEI into a life prediction model, the capacity recovery behavior for up to 1000 cycles under various operating conditions can be predicted. © 2024 Elsevier B.V.FALSEsciescopu
Pan-cancer proteogenomic landscape of whole-genome doubling reveals putative therapeutic targets in various cancer types
Get PDF[No Abstract Available]TRUEsci
TRIBOELECTRIC NANOGENERATOR, METHOD OF MANUFACTURING THE SAME, AND WEARABLE DEVICE INCLUDING THE SAME
No full text
Nitrogen-doped graphene quantum dots/ polyvinyl alcohol nanocomposite for photon management: Application in CIGS photovoltaic cells
No full textThe efficiency (η) of copper indium gallium selenide (CIGS) solar cells has been hampered by absorption losses that happen within the ZnO and CdS layers. A photon downconversion layer created from polyvinyl alcohol (PVA) and nitrogen-doped graphene quantum dots (NGQDs) composite (NGQDs/PVA) was implemented on the top of the cell to overcome this obstacle. Notably, the NGQDs/PVA layers, prepared at spin speeds of 3000, 4000, and 5000 rpm, exhibited optimal characteristics, demonstrating superior light absorption at low wavelengths along with elevated transmittance at longer wavelengths. The η was found to be highest for the layer prepared at 4000 rpm, accompanied by elevated values of short-circuit current (Jsc), open-circuit voltage (Voc), and fill factor (FF). Consequently, Cell #2 incorporating the champion NGQDs/PVA layer outperformed all other CIGS photovoltaic cells, showcasing an impressive enhancement of 8.96 % in Jsc, 1.62 % in Voc, 2.03 % in FF, and an overall η of 11.51 %. This champion cell significantly improves the performance of CIGS photovoltaics. © 2024FALSEsciescopu
Identification and characterization of novel ERBB4 variant associated with sporadic amyotrophic lateral sclerosis (ALS)
No full textAmyotrophic Lateral Sclerosis (ALS) is the most common type of motor neuron disease characterized by progressive motor neuron degeneration in brain and spinal cord. Most cases are sporadic in ALS and 5–10% of cases are familiar. >50 genes are known to be associated with ALS and one of them is ERBB4. In this paper, we report the case of a 53-year-old ALS patient with progressive muscle weakness and fasciculation, but he had no cognitive decline. We performed the next generation sequencing (NGS) and in silico analysis, it predicted a highly pathogenic variant, c.2116 A > G, p.Asn706Asp (N706D) in the ERBB4 gene. The amino acid residue is highly conserved among species. ERBB4 is a member of the ERBB family of receptor tyrosine kinases. ERBB4 has multiple tyrosine phosphorylation sites, including an autophosphorylation site at tyrosine 1284 residue. Autophosphorylation of ERBB4 promotes biological activity and it associated with NRG-1/ERBB4 pathway. It is already known that tyrosine 128 phosphorylation of ERBB4 is decreased in patients who have ALS-associated ERBB4 mutations. We generated ERBB4 N706D construct using site-directed mutagenesis and checked the phosphorylation level of ERBB4 N706D in NSC-34 cells. We found that the phosphorylation of ERBB4 N706D was decreased compared to ERBB4 wild-type, indicating a loss of function mutation in ERBB4. We report a novel variant in ERBB4 gene leading to ALS through dysfunction of ERBB4. © 2024 Elsevier B.V.FALSEsciescopu
Enhancing Li-Ion Battery Anodes: Synthesis, Characterization, and Electrochemical Performance of Crystalline C60 Nanorods with Controlled Morphology and Phase Transition
No full textRecently, C60 has emerged as a promising anode material for Li-ion batteries, attracting significant interest due to its excellent lithium storage capacity. The electrochemical performance of C60 as an anode is largely dependent on its internal crystal structure, which is significantly influenced by the synthesis method and corresponding conditions. However, there have been few reports on how the synthesis process affects the crystal structure and Li+ storage capacity of C60. This study used the liquid-liquid interface precipitation method and a low-temperature annealing process to fabricate one-dimensional C60 nanorods (NRs). We thoroughly investigated synthesis conditions, including the growth time, drying temperature, annealing time, and annealing atmosphere. The results demonstrate that these synthesis conditions directly impact the morphology, phase transition, and electrochemical efficiency of pure C60 NRs. Remarkably, the hexagonal close-packed structural C60 NRs-6012h, in a metastable form, exhibits a reversible Li+ storage capacity as an anode material in Li-ion batteries. Furthermore, the face-centered cubic C60 NRs-603001h electrode shows significantly enhanced rate performance and long-cycle stability. A discharge-specific capacity of 603 mAh g-1 was maintained after 2000 cycles at a current density of 2 A g-1. This study elucidates the effect of synthesis conditions on C60 crystals, offering an effective strategy for preparing high-performance C60 anode materials. © 2024 American Chemical SocietyFALSEsciescopu