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Laser-guided surface modification for high-capacity metallic anodes
No full textLithium metal batteries, Native passivation layer, Nanosecond-pulsed laser, Surface reconstruction, Interfacial evolutionⅠ. Introduction 1
1.1. Basic Principles of Lithium Secondary Batteries 1
1.2. Evolution of Lithium Metal Batteries 2
1.3. Next generation Batteries: Revisiting LMA 2
1.3.1. Superiority of LMBs 2
1.3.2. Challenges in LMBs Implementation: Inherent Inhomogeneity of LMAs 3
1.4. Surface treatment of LMA 4
1.5. Laser technology 5
1.6. Research Goals 5
Ⅱ. Experimental Method 6
2.1. Preparation of laser-treated Li 6
2.2. Preparation of electrolytes and cathodes 8
2.3. Cell assembly and electrochemical testing 8
2.4. Characterization 9
Ⅲ. Results and discussion 9
3.1. Analysis of characteristics of laser-treated Li surface 9
3.1.1. Structural characteristics 9
3.1.2. Chemical characteristics 11
3.1.3. Electrochemical characteristics 13
3.2. Morphological study of laser-treated Li 14
3.3. Cycling performance and postmortem analysis 16
Ⅳ. Conclusion 18
References 19
Summary in Korean 22MasterdCollectio
Automated fast label-free quantification of cardiomyocyte dynamics with raw holograms for cardiotoxicity screening
Get PDFTraditional cell analysis approaches based on quantitative phase imaging (QPI) necessitate a reconstruction stage, which utilizes digital holography. However, phase retrieval processing can be complicated and time-consuming since it needs numerical reconstruction and then phase unwrapping. For analysis of cardiomyocyte (CM) dynamics, it was reported that by estimating the spatial variance of the optical path difference from QPI, the spatial displacement of CMs can be quantified, thereby enabling monitoring of the excitation-contraction activity of CMs. Also, it was reported that the Farnebäck optical flow method could be combined with the holographic imaging information from QPI to characterize the contractile motion of single CMs, enabling monitoring of the mechanical beating activity of CMs for cardiotoxicity screening. However, no studies have analyzed the contractile dynamics of CMs based on raw holograms. In this paper, we present a fast, label-free, and high throughput method for contractile dynamic analysis of human-induced pluripotent stem cell-derived CMs using raw holograms or the filtered holograms, which are obtained by filtering only The proposed approach obviates the need for time-consuming numerical reconstruction and phase unwrapping for CM’s dynamic analysis while still having performance comparable to that of the previous methods. Accordingly, we developed a computational algorithm to characterize the CM’s functional behaviors from contractile motion waveform obtained from raw or filtered holograms, which allows the calculation of various temporal metrics related to beating activity from contraction-relaxation motion-speed profile. To the best of our knowledge, this approach is the first to analyze drug-treated CM’s dynamics from raw or filtered holograms without the need for numerical phase image reconstruction. For one hologram, the reconstruction process itself in the existing methods takes at least three times longer than the process of tracking the contraction-relaxation motion-speed profile using optical flow in the proposed method. Furthermore, our proposed methodology was validated in the toxicity screening of two drugs (E-4031 and isoprenaline) with various concentrations. The findings provide information on CM contractile motion and kinetics for cardiotoxicity screening. © 2025 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement.TRUEsciescopu
리소그래피 기반 패터닝 가능한 자기 폴리머 복합체의 제조 및 응용
No full textLithography, Z-axis arrangement Fe₃O₄ , PHMR sensor, Magnetophoretic circuit, Cell delivery boatAbstract ⅰ
List of contents ⅱ
List of tables ⅳ
List of figures ⅳ
Ⅰ. Introduction 1
1.1 Motivation 1
1.2 Trends of study 3
1.3. The necessity of study 5
Ⅱ. Background 8
2.1 Dipole-dipole interaction 8
2.2 Magnetic flux gradient 10
Ⅲ. Materials and method 12
3.1 Materials 12
3.1.1 Photoresist 12
3.1.2 Magnetism 13
3.2 Method 16
3.2.1 Photo-lithography 16
3.2.2 Sputtering 19
Ⅳ. Experiments 22
4.1 Fabrication 22
4.1.1 Magnetic polymer composite (MPC) 22
4.1.2 Z-axis magnetic field application equipment 24
4.1.3 Lithography-compatible magnetic polymer composite 25
4.2 Application 28
4.2.1 Magnetophoretic circuit 28
4.2.2 Cell delivery boat 30
4.2.3 Device integration 33
4.3 Measurement 38
4.3.1 Vibrating Sample Magnetometer (VSM) 38
4.3.2 Scanning Electron Microscope (SEM) 39
4.3.3 Ultraviolet-Visible-Near Infrared Spectrophotometer 40
4.3.4 Magnetoresistance (MR) measurement 41
4.3.5 Rotating field Microscope 42
Ⅴ. Result and Discussion 43
5.1 MPC properties 43
5.2 Magnetophoretic circuit 49
5.3 Cell delivery boat 51
5.4 Device integration 53
Ⅵ. Conclusion 56
References 58
Summary 60MasterdCollectio
최신 저장 기술을 활용한 고효율 키-값 저장 시스템 연구
No full textKey-value storage system, Key-value store, Key-value cache, Multi-tiered memory system, File systemThis dissertation investigates efficient key-value (KV) storage systems using emerging storage technologies to meet modern data center demands. The study introduces four systems—LightStore, BigKV, MigFlow, and KEVIN—to reduce costs and improve performance. LightStore replaces x86 servers with lightweight, ARM-based SSD nodes directly connected to networks, achieving 2.0× better power efficiency, 2.3× greater space efficiency, and up to 7.4× higher energy efficiency. BigKV optimizes flash-based KV caching for large objects, improving throughput by 3.5× and reducing latency by 57%, enabling cost-effective, petabyte-scale caching. MigFlow enhances multi-tiered memory systems using persistent memory and CXL. With MigOpt, an offline optimizer, MigFlow reduces migration overhead and achieves up to 2.76× better performance while cutting migration traffic by 60.6%. KEVIN integrates file systems directly with KV storage, eliminating block-based overhead. It improves metadata performance by 6.2× and boosts throughput by 68% for real workloads. This work demonstrates how emerging technologies can enhance scalability, efficiency, and cost-effectiveness in hyperscale data centers. Keywords: Key-value storage system, Key-value store, Key-value cache, Multi-tiered memory system, File system.|본 논문은 차세대 스토리지 기술을 활용하여 효율적인 키-값 저장 시스템을 설계하고 현대 데이터 센터의 성능과 비용 문제를 해결하는 방법을 제시한다. 이를 위해 LightStore, BigKV, MigFlow, KEVIN 네 가지 시스템을 제안한다. LightStore는 ARM 기반의 SSD 노드를 도입해 기존 x86 기반 키-값 스토리지 서버를 대신하는 역할을 수행하며, 이로써 전력 효율을 2.0배, 공간 효율을 2.3배 향상시키며 에너지 효율은 최대 7.4배 높인다. BigKV는 대형 객체를 효율적으로 캐싱하는 플래시 기반 키-값 캐시로서, 처리량을 3.5배 향상시키고 지연 시간을 57% 줄여 페타바이트 캐싱 비용을 절감한다. MigFlow는 PMEM과 CXL을 활용 등을 사용하는 이기종 멀티 티어 메모리 최적화 시스템으로, MigOpt의 오프라인 분석을 통해 마이그레이션 오버헤드를 줄이고 성능을 최대 2.76배 향상시킨다. KEVIN은 파일 시스템을 키-값 저장소와 직접 통합해 블록 추상화를 제거하고, 메타데이터 성능을 6.2배, 처리량을 68% 개선한다. 본 연구는 차세대 스토리지 기술을 기반으로 확장성과 비용 효율성을 개선하는 새로운 키-값 저장 시스템을 제시한다.1 Introduction 1
2 LightStore 5
2.1 Introduction 5
2.2 Related Work 9
2.3 LightStore Overview 10
2.4 Design of LightStore Node 12
2.4.1 LightStore Controller 12
2.4.2 LightStore Software 14
2.5 Expected Operating Cost 23
2.6 Experimental Results 24
2.6.1 Prototype and Experimental Setup 25
2.6.2 LightStore as a Key-value Store 27
2.6.3 Evaluation under Datacenter Applications 36
3 BigKV 40
3.1 Introduction 40
3.2 Background and Related Work 43
3.2.1 NAND Flash and All-Flash Array 44
3.2.2 Persistent Key-value Stores 45
3.2.3 Key-value Caches for Flash 46
3.3 Motivation 47
3.3.1 Huge Metadata and High Overhead 48
3.3.2 Space Waste by Expired Objects 50
3.3.3 Fault Tolerance vs Parity Cost 51
3.4 Design and Implementation of BigKV 52
3.4.1 Overall Architecture of BigKV 54
3.4.2 Object Indexing with Two-level Metadata 55
3.4.3 TTL-aware Space Management 60
3.4.4 Reactive Fault Tolerance Mechanism 64
3.5 Experiments 66
3.5.1 Experimental Setup 66
3.5.2 Experimental Results 68
4 MigFlow 77
4.1 Introduction 77
4.2 Background and Related Work 80
4.2.1 Tiered Memory System 81
4.2.2 Traditional 2-tier Memory System 82
4.2.3 Multi-tiered Memory System 83
4.3 Motivation 85
4.4 MigOpt 89
4.4.1 Existing Research for Exploring the Optimality 90
4.4.2 Providing the Optimality for Multi-tiered Systems 91
4.4.3 Analysis of MigOpt Results 93
4.5 MigFlow 97
4.5.1 MigFlow Overview 97
4.5.2 Top-down Allocation and Page Monitoring 99
4.5.3 Migration Policy 100
4.6 Experiments 102
4.6.1 Experimental Setup 103
4.6.2 Experimental Results 105
5 KEVIN 109
5.1 Introduction 109
5.2 Background and Related Work 113
5.2.1 Traditional Block I/O Interface 113
5.2.2 Review of In-Storage Indexing 114
5.2.3 File System over Key-value Store 116
5.2.4 LSM-Tree Basics 117
5.3 Overall Architecture of KEVIN 118
5.3.1 Mapping of File and Directory 119
5.3.2 Indexing of KV Objects 121
5.3.3 Mitigating Indexing Overhead 124
5.4 Implementing VFS Operations 127
5.5 Crash Consistency 130
5.5.1 Maintaining Consistency in KEVINFS 131
5.5.2 Transaction Processing in KEVINSSD 133
5.6 Experiments 135
5.6.1 Experimental Setup 135
5.6.2 Experimental Results 136
6 Conclusions 147
References 150DoctordCollectio
Artificial tilted of spin structure of a cobalt thin film within a Co/VOx magnetic heterostructure
No full textVanadium oxide (VOx), Interfacial Dzyaloshinskii-Moriya interaction (iDMI), Perpendicular magnetic anisotropy (PMA), Brillouin light scattering spectroscopy (BLS), MOKE (Magneto-optical Kerr effect)List of Contents
Abstract i
List of contents ii
List of figures iv
I. Introduction 1
IⅠ. Theoretical backgrounds 7
2.1 Exchange interaction 7
2.1.1 Heisenberg exchange interaction 7
2.1.2 Dzyaloshinskii-Moriya interaction 9
2.2 Magnetic anisotropy energy 13
2.2.1 Magneto-crystalline anisotropy 13
2.2.2 Shape magnetic anisotropy 17
2.2.3 Interfacial magnetic anisotropy 21
2.3 The other magnetic energies 24
2.3.1 Zeeman energy· 24
2.3.2 Landau-Lifshitz-Gilbert equation 25
2.4 Spin wave 30
2.4.1 Basic concept of spin wave 30
2.4.2 Mechanism of inelastic scattered light 33
2.5 Hall effect 35
IIⅠ. Fabrication process and Experiment tools 39
3.1 Magnetic multilayer deposition 39
3.2 Experimental tools 42
3.2.1 Magneto-optical Kerr effect 42
3.2.2 SQUID-VSM measurements 45
3.2.3 Physical properties measurement system and transport measure 46
3.2.4 Transmission Electron Microscope-Electron Energy Loss Spectroscopy 47
ⅠV. Result and discussion 52
Ferromagnetism of pure vanadium oxide and their magnetic properties 53
4.1 Overview 53
4.2 Introduction 54
4.3 Experimental results and discussion 56
4.4 Summary 75
V. Result and discussion 77
Unconventional energy occurring in vanadium oxide and the ferromagnetic layer 78
5.1 Overview 78
5.2 Introduction 79
5.3 Experimental result and discussion 81
5.4 Summary 90
VI. References 92DoctordCollectio
Efficient Multimodal Model Training Techniques Using Storage Servers
No full textAI 시스템, 데이터 주변 처리, 멀티모달 모델, 모델 프리징, AI 최적화Ⅰ. Introduction 1
Ⅱ. Background 3
Ⅲ. Motivation 7
Ⅳ. Designs 11
Ⅴ. Experiments 16
Ⅵ. Conclusions 25MasterdCollectio
심장 질환 진단을 위한 방향성 초음파 탄성영상
No full textHigh-frequency ultrasound, Ultrasound elastography, Mechanical anisotropy, Tissue characterization, Heart disease심혈관 질환은 전 세계적으로 사망의 주요 원인입니다. 이러한 높은 사망률의 주요 원인 중 하나는 효과적으로 병을 조기에 진단할 수 있는 진단 방법이 부족하기 때문이다. 최근 에는 조직의 기계적 특성이 병리학적 상태와 밀접하게 관련되어 있다는 사실을 바탕으로 탄성 영상이라는 진단 방법이 발전하고 있다. 하지만 심장 조직은 심근섬유의 방향 때문에 이방성 기계적 특성을 지니며, 이는 탄성 영상을 이용한 심장 질환 진단을 어렵게 한다. 본 논문은 이러한 어려움을 고려하여 심장 조직 진단에 탄성 영상을 적용하는 방법을 다룬다. 특히, 탄성 영상 기법 중 초음파 기반의 전단파 탄성 영상을 고려하여 심장 조직의 정량적 상태 평가를 위한 새로운 영상 시스템 및 진단 지표를 제안한다.
첫 번째로, 심장 조직의 이방성 기계적 특성을 다루기 위한 새로운 초음파 기반 전단파 탄성 영상 시스템을 제안한다. 기존의 초음파 전단파 탄성 영상 시스템을 이용하여 돼지 심장의 다양한 방향과 위치에 따른 기계적 특성 변화를 분석하여 새로운 초음파 전단파 탄성 영상 시스템 개발의 필요성을 보여준다. 이를 바탕으로 체외 방향성 전단파 탄성 영상 시스템을 개발하고, 절제된 돼지 심장 조직의 이방성 기계적 특성을 관찰한다.
두 번째로, 이방성 기계적 특성을 평가하는 새로운 지표를 제안한다. 이방성 기계적 특성을 평가하는 기존 지표는 심장 조직의 점도와 기하학의 영향으로 인해 심장 질환을 정 확하게 진단하기에 충분하지 않다. 따라서 심장 조직의 이방성 기계적 특성을 정량화하기 위한 새로운 지표로 최대 코사인 유사도가 제안한다. 이 지표는 전파 방향에 따라 전단파 속도의 주기 및 모양을 분석하여 이방성 기계적 특성을 평가한다. 독소루비신을 사용한 쥐 심장 실험을 수행하고, 실험 데이터에 최대 코사인 유사도를 적용하였다. 쥐 심장의 조 직병리학적 변화와 쥐 심장에 대한 최대 코사인 유사도 결과의 비교를 통해 최대 코사인 유사도를 유효성을 보여준다.
마지막으로, 심장의 이방성 기계적 특성을 측정하기 위한 새로운 유형의 초음파 변환 기를 제안한다. 외부에서 심장을 측정하는 기존 방법은 침투 깊이가 깊어야 하기 때문에 저주파 초음파 프로브를 사용한다. 그러나 진단 정확도를 높이고 조기 발견을 가능하게 하 려면 고주파수 프로브를 사용해야 한다. 따라서 본 논문에서는 심장 내 탄성 영상 시스템을 제안한다. 하지만 심장 내 심장초음파 카테터의 크기가 제한되어 있기 때문에 모든 방향에 서 이방성 거동을 측정하는 것이 어렵다. 이 문제를 해결하기 위해 세 가지 다른 방향에서 전단파 속도를 측정하는 새로운 심장 내 초음파 변환기를 설계하고 측정된 세 가지 전단파 속도를 사용하여 이방성 기계적 특성을 추정하는 것이 심장 내 탄성파 시스템에 적용된다. 심장 내 탄성 영상 시스템은 체외 방향성 전단파 탄성 영상 시스템과 비교하여 유효성이 검증된다.|Cardiovascular diseases are the leading cause of death worldwide. One of the primary reasons for the high mortality rate is the lack of effective diagnostic methods for early detection. Conventional diagnostic methods are generally applied to evaluate the extent of cardiac damage after cardiac dysfunction has manifested. Therefore, advances in diagnostic methods and the development of diagnostic instruments are still needed. The mechanical properties of biological tissues, including heart tissue, are closely related to pathological states, as diseases alter the mechanical properties of tissue. Based on this relation, a medical imaging method called elastography could serve as an advanced diagnostic method for assessing the condition of heart tissue. However, heart tissue exhibits anisotropic mechanical behavior (directional mechanics) because of the direction of the fiber, which causes challenges in the diagnosis of heart disease. This dissertation addresses applications of ultrasound-based elastography to a diagnosis of heart tissue considering these challenges. Specifically, ultrasound-based shear wave elastography is addressed in this dissertation to evaluate the quantitative state of heart tissue. The first problem addresses the anisotropic mechanical behavior of the heart and proposes the necessity of a new ultrasound elastography system for evaluating directional mechanics. The mechanical behaviors at different directions and different locations are analyzed on dissected swine hearts. It implies the necessity of a directional ultrasound elastography system. Based on this result, an ex vivo directional ultrasound elastography system is developed, which allows an observation of anisotropic mechanical behavior for the dissected tissues. The second problem concerns a metric to quantify directional mechanics. Conventional metrics quantifying directional mechanics are insufficient for accurately diagnosing heart disease due to the influence of viscosity and geometry of heart tissues. Thus, a new metric, maximum cosine similarity, is proposed. This metric quantifies directional mechanics by evaluating the periodicity and shape of the shear wave speeds depending on the propagation directions. Animal experiments were performed on forty rat hearts, some of which were administered doxorubicin. The histopathological changes of the rat heart agree with the results of maximum cosine similarity in rat hearts, which validates maximum cosine similarity. Finally, we propose a new type of ultrasound transducer for measuring the directional mechanics of the heart. Existing methods for measuring the heart externally utilize low- frequency ultrasound probes due to the need for greater penetration depth. However, improving diagnostic accuracy and enabling early detection requires the use of higher- frequency probes. Consequently, the development of an intracardiac elastography system is necessary. However, it is difficult to measure the anisotropic behavior in all directions because intracardiac echocardiography catheters are limited in size. To solve this problem, we designed a new intracardiac ultrasound transducer to measure shear wave speed in three different directions, and the estimation method for directional mechanics, using three measured shear wave speeds, was applied to the intracardiac elastography system. The intracardiac elastography system is validated through the comparison to ex vivo directional ultrasound elastography system.1 Introduction 1
1.1 Necessity of Developing Diagnostic Tools for Heart Disease 1
1.2 Background 3
1.2.1 Mechanical Properties of Tissue 3
1.2.2 Ultrasound Elastography 6
1.3 Contributions and Outline of Dissertation 7
2 A High-Frequency Directional Ultrasound Elastography System for Analyzing Directional Mechanics 13
2.1 Imaging System Development 14
2.1.1 Hardware Setup and Specification 14
2.1.2 Image Processing to Acquire Directional Mechanics 17
2.2 Experimental Preparation 19
2.2.1 Phantom Experiments 19
2.2.2 Animal Experiments 20
2.2.3 Calculation of Spatial Resolution 20
2.3 Results 21
2.3.1 Phantom Experiments 21
2.3.2 Animal Experiments 26
2.4 Discussion 34
2.5 Conclusion 36
3 A New Metric to Quantify Directional Mechanics Measured by Directional Ultrasound Elastography 39
3.1 Maximum Cosine Similarity 40
3.2 Fractional Anisotropy 41
3.3 Experimental Preparation 41
3.3.1 Experimental Setup 41
3.3.2 Anisotropic Phantom Fabrication 42
3.3.3 Animal Models 44
3.3.4 Histopathological Assessment 46
3.3.5 Statistical Analysis 46
3.4 Results 48
3.4.1 Phantom Experiment 48
3.4.2 Baseline Experimental Animal Characteristics 49
3.4.3 Shear Wave Speed Maps for Rat Hearts 50
3.4.4 Histological Evaluation of Rat Hearts 55
3.4.5 Comparison of MaxCosim and Histological Evaluation in Rat Hearts 58
3.5 Discussion 60
3.6 Conclusion 63
4 New Type of Intracardiac Ultrasound Probe for Evaluating Directional Mechanics 65
4.1 Intracardiac Directional Ultrasound Elastography System 66
4.1.1 Intracardiac Ultrasound Transducer 66
4.1.2 Imaging System 68
4.2 Shear Modulus Estimation Method 70
4.3 Design of Phantom Experiment 72
4.4 Results 72
4.4.1 Isotropic Phantom 72
4.4.2 Anisotropic Phantom 73
4.5 Discussion 75
4.6 Conclusion 76
5 Conclusion 79
Bibliography 81
국문초록 91DoctordCollectio
생체결합입자 제어 및 세포 스크리닝을 위한 마이크로 자기 운동 시스템
No full textMagnetophoresis, Cell screening, Magnetic particle, Droplet microfluidics, Magnetic thin filmⅠ. Introduction 1
1.1 Motivation 1
1.2 Overview of the study 13
1.3 Theoretical background 15
1.3.1 Magnetophoretic-based manipulation 15
1.3.1.1 Fundamental principle of magnetophoresis 16
1.3.1.2 Micro-magnetophoretic circuits 18
1.3.2 Magnetically actuated droplet manipulation 25
1.3.2.1 Fundamental principle of magnetic droplet manipulation 30
1.3.2.2 Applications based on magnetic droplet manipulation 33
1.3.3 Cell screening method 35
1.3.3.1 Cell cytotoxicity assay 35
1.3.3.2 Doxorubicin mediated cell death 37
1.3.3.3 Calcium signaling 38
Ⅱ. Material and method 43
2.1 Fabrication of microscale magneto-kinetic system 43
2.1.1 Sputtering-based process 43
2.1.1.1 Photolithography 43
2.1.1.2 Direct-current magnetron sputtering 44
2.1.1.3 Lift-off and fabrication of passivation layer 44
2.1.2 Electrochemical deposition-based process 45
2.1.2.1 Fabrication of micro-pattern templet by photolithography 45
2.1.2.2 Electrochemical deposition 45
2.2 Integration of microfluidic and magneto-kinetic system 47
2.2.1 Fabrication of microfluidic channel 47
2.2.2 Droplet generating microfluidic system 48
2.3 Preparation of biochemical components 50
2.3.1 Antibody conjugation on micro magnetic particle for labeling cells 50
2.3.2 Conjugation of polystyrene beads to magnetic particles 51
2.3.3 Doxorubicin loading on nano magnetic particle for drug delivery 52
2.3.4 Drug response test using DOX-loaded nanoparticles (NPs) 53
2.4 Analysis equipment 54
2.4.1 Magneto-Optical Kerr Effect (MOKE) 54
2.4.2 Vibration Sample Magnetometer (VSM) 54
2.4.3 UV-vis spectrophotometer 55
2.4.4 Scanning Electron Microscope (SEM) 55
2.4.5 Atomic Force Microscope (AFM) 56
2.5 Analysis using simulations 56
2.5.1 Micromagnet simulation, Mumax3 56
2.6 Cell preparation 58
2.6.1 Cell culture and treatment 58
2.6.2 Binding cells to antibody-coated magnetic particles 58
2.6.3 Cell staining for viability assay 58
2.6.4 Live cell calcium imaging 59
2.7 Experimental setup 59
Ⅲ. Results and discussion 61
3.1 Selective cell sorting with parameters control 61
3.1.1 Size-based cell sorting by ellipse-shaped micromagnet 61
3.1.2 Trapping desired number of particles using topographic structure ·· 70
3.1.3 Conclusion 76
3.2 On-chip drug response test using nanoparticle 77
3.2.1 A systemic design for on-chip drug response test 77
3.2.2 Collection and transportation of MNPs 78
3.2.3 Drug loading and release characteristics of MNPs 80
3.2.4 Drug response test for potential Cell-on-chip applications 83
3.2.5 Conclusion 85
3.3 Droplet manipulation based on magneto-kinetic system 86
3.3.1 Design of a hybrid system for droplet manipulation 87
3.3.2 Adjusting magnetic force from magnetic disk 92
3.3.3 Droplet generation by microfluidic channel 98
3.3.4 Investigation of operating conditions for droplet manipulation 100
3.3.5 Conclusion 104
3.4 Cell-cell communication study 105
3.4.1 Calcium dynamics of MCF-7 in confined droplets 105
3.4.2 Calcium dynamics of HUVEC with stimulus in open space 107
3.4.3 Conclusion 109
Ⅳ. Conclusion 110
4.1 Conclusion of the works 110
References 113
Summary (in Korean) 124
List of publications 125DoctordCollectio
초음파와 광 에너지를 결합하여 유도된 가스 기포를 기반으로 한 심층 광학 이미징 기술
No full textOptical scattering, Light penetration, Combined ultrasound and laser energy, Gas bubbles, Deep optical microscopyⅠ. Introduction 1
1.1 Optical Microscopy 1
1.1.1 Why Optical Microscopy? 1
1.1.2 History and Principle of Optical Microscopy 2
1.2 Light Penetration Depth in Optical Microscopy 6
1.2.1 Interaction in Tissue and Light 8
1.2.2 Limitation of Light Penetration Depth 9
1.3 Deep Tissue Imaging Techniques 14
1.3.1 Two-Photon Microscopy 14
1.3.2 Wavefront Shaping 17
1.3.3 Optical Clearing Methods 21
1.3.4 Ultrasound-Induced Optical Clearing Microscopy (US-OCM) 24
1.4 Objective of Research 27
1.5 Dissertation Organization 28
Reference 30
ⅠI. Control of Optical Imaging Depth using Ultrasound-Induced Gas Bubbles for Deep Optical Microscopy
2.1 Introduction 37
2.2 Principle of FI-OCM 41
2.3 Materials and Methods 43
2.3.1 Configuration of FI-OCM system 43
2.3.2 Fabrication and Characteristics of 2 MHz ring-typed ultrasound transducer with long-wavelength for gas bubble generation. 46
2.3.3 Experimental arrangement for ultrasound-induced gas bubbles generation and observation inside the tissue-mimicking phantom. 49
2.4 Results 51
2.4.1 Observation of the ultrasound-induced gas bubbles due to the change in ultrasound frequency inside the tissue-mimicking phantom. 51
2.4.2 The measurement of light-beam distribution affected by ultrasound-induced gas bubbles by changing the ultrasound frequency. 53
2.4.3 Imaging performance affected by ultrasound-induced gas bubbles by changing the ultrasound frequency in the tissue-mimicking phantom with fluorescent bead. 56
2.5 Experimental Section 59
2.6 Discussion and Conclusion 61
Reference 63
ⅠII. Gas Bubbles Induced by Combined Optical and Ultrasound Energies for High-Resolution Deep Optical Microscopy
3.1 Introduction 67
3.2 Principle of OPS-DOM 71
3.3 Materials and Methods 73
3.3.1 Fabrication of a 1 MHz donut-shaped ultrasound transducer for gas bubble generation 73
3.3.2 Experimental arrangement for optrasound-induced gas bubble generation and observation of the tissue-mimicking phantom 76
3.3.3 OPS-DOM configuration and experimental setup arrangement 79
3.4 Results 81
3.4.1 Parameter determination for pre-established ultrasound field using the finite element method (FEM) 81
3.4.2 Observation of the optrasound-induced gas bubbles inside the tissue-mimicking phantom 83
3.4.3 Measurement of light beam distribution affected by optrasound-induced gas bubbles 91
3.4.4 Imaging performance evaluation of OPS-DOM in the tissue-mimicking phantom 92
3.5 Experimental Section 95
3.6 Discussion and Conclusion 97
Reference 101
IV. In Vivo Study of the Integrated Confocal Fluorescence and Photoacoustic Microscopy for High-Resolution Deep Tissue Imaging
4.1 Introduction 105
4.2 Principle of Multi-OCM 109
4.3 Materials and Methods 112
4.3.1 Configuration of Multi-OCM System 112
4.3.2 Operating sequence of Multi-OCM system 114
4.3.3 Fabrication of a fusion transducer for gas bubble generation and detection of photoacoustic signal 117
4.4 Results 119
4.4.1 Imaging performance evaluation of Multi-OCM in the tissue-mimicking phantom and chicken breast 119
4.4.2 Imaging performance evaluation of Multi-OCM in the mouse tumor for in vivo 123
4.5 Experimental Section 126
4.6 Discussion and Conclusion 129
Reference 132
V. Conclusion and Future WorksDoctordCollectio
Surface Engineering of Nanocrystals for Highly Efficient Optoelectronic Devices
No full textNanocrystals, Surface engineering, ZnO, CsPbBr3, Solar cells, QLEDsList of Contents
ABSTRACT. i
List of Contents ii
List of Tables iv
List of Figures v
CHAPTER 1. INTRODUCTION 1
1.1. Nanocrystals & surface engineering 1
1.1.1. Nanocrystals 1
1.1.2. Quantum confinement effect 2
1.2. Surface engineering of nanocrystals 8
1.2.1. Surface chemistry and electronic structure of nanocrystals 8
1.2.2. Surface engineering of nanocrystals 9
1.3. Optoelectronic applications 10
1.3.1. Photovoltaics 10
1.3.2. Light-emitting diodes 14
CHAPTER 2. Solvent Miscibility-Driven Solid-State Ligand Exchange for High-Voltage, Green-Emitting Perovskite Nanocrystal Solar Cells 20
2.1. Introduction 20
2.2. Experimental 23
2.2.1. Materials 23
2.2.2. Synthesis of CsPbBr3 PNCs. 23
2.2.3. CsPbBr3 PNC Solar cell fabrication. 24
2.2.4. Characterization. 25
2.3. Results and discussion. 26
2.4. Conclusion 54
CHAPTER 3. Diverse Exciton Recombination Pathways and Enhanced Stability of Perovskite Nanocrystals through Plasmonic Photonic Crystals 56
3.1. Introduction 56
3.2. Experimental 58
3.2.1. Chemicals. 58
3.2.2. Synthesis of CsPbX3 (X = I or Br) Perovskite NCs 58
3.3. Results and discussion. 61
3.4. Conclusion 81
CHAPTER 4. Surface Passivation of Zinc Oxide Electron Transporting Layer Using Benzoic Acids for High-Efficiency Nanocrystal Light-Emitting Diodes 83
4.1. Introduction 83
4.2. Experimental 84
4.2.1. Materials 84
4.2.2. Surface passivation of ZnO with benzoic acids 85
4.2.3. Device fabrication 85
4.2.4. Characterization 85
4.3. Results and discussion. 86
4.4. Conclusion 95
CHAPTER 5. Conclusions 96
References 99
요 약 문 120DoctordCollectio