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Way-out for laser-induced breakdown spectroscopy

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Plasma Science and Technology 2020年第7期22卷 1-3页

作者： Zongyu HOU Sungho JEONG yoshihiro deguchi Zhe WANG State Key Lab of Power Systems International Joint Laboratory on Low Carbon Clean Energy InnovationDepartment of Energy and Power EngineeringTsinghua UniversityBeijing 100084People’s Republic o f China School of Mechanical Engineering Gwangju Institute of Science and TechnologyGwangju 61005Republic of Korea Graduate School of Technology Industrial and Social SciencesTokushima UniversityTokushima 770-8501Japan

Ever since its creation in 1963 [1], laser-induced breakdown spectroscopy(LIBS)has gained considerable attention due to its unique capability for real-time, in situ or online analysis [2, 3]. The future world is headi... 详细信息

关键词： breakdown laser spectroscopy

Performance Improvements in Temperature Reconstructions of 2-D Tunable Diode Laser Absorption Spectroscopy(TDLAS)

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Journal of Thermal Science 2016年第1期25卷 84-89页

作者： Doo-Won Choi Min-Gyu Jeon Gyeong-Rae Cho Takahiro Kamimoto yoshihiro deguchi Deog-Hee Doh Tokushima University 2-1 Minamijyosanjima TokushimaJapan Korea Maritime&Ocean University Dongsam-dong 1 Youngdo-guBusan 606-791Korea

Performance improvement was attained in data reconstructions of 2-dimensional tunable diode laser absorption spectroscopy(TDLAS). Multiplicative Algebraic Reconstruction Technique(MART) algorithm was adopted for data reconstruction. The data obtained in an experiment for the measurement of temperature and concentration fields of gas flows were used. The measurement theory is based upon the Beer-Lambert law, and the measurement system consists of a tunable laser, collimators, detectors, and an analyzer. Methane was used as a fuel for combustion with air in the Bunsen-type burner. The data used for the reconstruction are from the optical signals of 8-laser beams passed on a cross-section of the methane flame. The performances of MART algorithm in data reconstruction were validated and compared with those obtained by Algebraic Reconstruction Technique(ART) algorithm.

关键词： Data Reconstruction TDLAS MART ART

Laser-induced breakdown spectroscopy in Asia

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Frontiers of physics 2016年第6期11卷 231-255页

作者： Zhen-ZhenWang yoshihiro deguchi Zhen-Zhen Zhang Zhe Wang Xiao-Yan Zeng Jun-Jie Yan State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an 710049 China Graduate School of Advanced Technology and Science Tokushima University Tokushima 770-8501 Japan State Key Lab of Power Systems Department of Thermal Engineering Tsinghua-BP Clean Energy Center Tsinghua University Beijing 100084 China Wuhan National Laboratory for Optoelectronics (WNLO) Huazhong University of Science and Technology Wuhan ~3007~ China

Laser-induced breakdown spectroscopy (LIBS) is an analytical detection technique based on atomic emission spectroscopy to measure the elemental composition. LIBS has been extensively studied and developed due to the non-contact, fast response, high sensitivity, real-time and multi-elemental detection features. The development and applications of LIBS technique in Asia are summarized and discussed in this review paper. The researchers in Asia work on different aspects of the LIBS study in fundamentals, data processing and modeling, applications and instrumentations. According to the current research status, the challenges, opportunities and further development of LIBS technique in Asia are also evaluated to promote LIBS research and its applications.

关键词： laser-induced breakdown spectroscopy (LIBS) quantitative analysis signal enhancement applications challenges

Remote open-path laser-induced breakdown spectroscopy for the analysis of manganese in steel samples at high temperature

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Plasma Science and Technology 2019年第3期21卷 52-59页

作者： Minchao CUI yoshihiro deguchi Zhenzhen WANG Seiya TANAKA Min-Gyu JEON Yuki FUJITA Shengdun ZHAO School of Mechanical Engineering Xi'an Jiaotong University Graduate School of Advanced Technology and Science University of Tokushima State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Division of Mechanical Engineering Korea Maritime and Ocean University School of Mechanical Engineering Xi’an Jiaotong University

A remote open-path laser-induced breakdown spectroscopy(LIBS) system was designed and studied in the present work for the purpose of combining the LIBS technique with the steel production line. In this system, the relatively simple configuration and optics were employed to measure the steel samples at a remote distance and a hot sample temperature. The system has obtained a robustness for the deviation of the sample position because of the open-path and alloptical structure. The measurement was carried out at different sample temperatures by placing the samples in a muffle furnace with a window in the front door. The results show that the intensity of the spectral lines increased as the sample temperature increased. The influence of the sample temperature on the quantitative analysis of manganese in the steel samples was investigated by measuring ten standard steel samples at different temperatures. Three samples were selected as the test sample for the simulation measurement. The results show that, at the sample temperature of 500 ℃, the average relative error of prediction is 3.1% and the average relative standard deviation is 7.7%, respectively.

关键词： remote open-path LIBS steel manganese sample temperature quantitative analysis

Application of Tunable Diode Laser Absorption Spectroscopy with Optical Hollow Fiber to Engine Exhaust Gas Measurement

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Journal of Mechanics Engineering and Automation 2012年第11期2卷 656-662页

作者： Akira Adachi yoshihiro deguchi Shinichirou Konishi Graduate School of Advanced Technology and Science The University of Tokushima Tokushima 770-8506 Japan

In recent years, tighter regulation has been already enforced on harmful substances such as NOx, CO, and particles. Considering the above situation, it is important to monitor controlling factors of engine systems in order to improve efficiencies of their operations. As to car engines, an increasing concern in environmental issues such as air pollution, global warming and petroleum depletion has helped drive researches into various ways. Laser diagnostics has been applied to measure species concentration in the actual industrial fields. However there are several challenges to proceed in applying laser diagnostics to practical application. Especially stability of the measurement system is one of the most difficult issues. The purpose of this research is the development of a prompt measurement technique which can be applicable to various engine conditions. The Tunable Diode Laser Absorption Spectroscopy （TDLAS） using the hollow fiber has been developed to satisfy above requirements. By using a hollow fiber, misalignment of an optical axis and vulnerability of measurement environment such as vibration can be greatly reduced with sensitive and fast response features. It was demonstrated that this method can be applicable to measure gas compositions in engine exhaust with a range of millisecond response time. A sensitive method using tunable UV diode laser absorption spectroscopy was also discussed to detect NOx in exhausts.

关键词： Tunable diode laser absorption spectroscopy optical hollow fiber exhaust gas concentration measurement.

Development of 2D Temperature and Concentration Measurement Method Using Tunable Diode Laser Absorption Spectroscopy

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Journal of Mechanics Engineering and Automation 2012年第9期2卷 543-549页

作者： yoshihiro deguchi Daisuke Yasui Akira Adachi Graduate School of Advanced Technology and Seienee The University of Tokushima Tokushima 770-8506 Japan

Exhaust gas temperature is an important factor in NOx, THC and PM emissions of engines. Especially 2D temperature and concentration distribution plays an important role for the engine efficiency. A thermocouple is intrinsically a point temperature measurement method and noncontact 2D temperature distribution cannot be attained by thermocouples. Recently, as a measurement technique with high sensitivity and high response, laser diagnostics has been developed and applied to the actual engine combustions. With these engineering developments, transient phenomena such as start-ups and load changes in engines have been gradually elucidated in various conditions. In this study, the theoretical and experimental research has been conducted in order to develop the noncontact and fast response 2D temperature and concentration distribution measurement method. The method is based on a Computed Tomography （CT） method using absorption spectra of water vapor at 1388 nm. It has been demonstrated that the method has been successfully applied to engine exhausts to measure 2D temperature distributions.

关键词： 2D temperature measurement tunable diode laser absorption spectroscopy CT (computed tomography) engine exhausts.

Effect of Heterogeneity of Porous Media on Gas Permeation and Entrapment

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Journal of Flow Control, Measurement & Visualization 2014年第3期2卷 110-119页

作者： Yohei Mikami yoshihiro deguchi Tetsuya Suekane The University of Tokushima Tokushima Japan Tokyo Institute of Technology Yokohama Japan

Capillary trapping prevents the migration of CO2 in reservoirs due to buoyancy. The residual gas saturation is strongly influenced by the gas saturation after gas injection. In this study, we have investigated the effect of stratified structure of heterogeneous porous media on gas permeation and entrapment. Experiments were carried out at a laboratory condition for a nitrogen-water system with the packed beds of glass beads with various diameters which modeled stratified porous media. In the case of parallel structure, the injected gas selectively percolated into permeable layers. The gas permeation can hardly occur for the less permeable layers because of the capillary entrance pressure. In the case of serial structure, the interface of porous structure hindered the migration of gas across it, because of the capillary entrance pressure. When the gas percolated in the permeable layers, capillary fingering was developed in the layers. However, when the tip of finger reached the interface, fingers grew in tangential directions until the pressure built up to overcome the capillary entrance pressure. As a result, high gas saturation was achieved in the permeable layers of both upward and downward gas injections.

关键词： Carbon Dioxide Capture and Storage (CCS) Residual Gas Trapping X-Ray CT Capillarity

Simple and robust 3D MINFLUX excitation with a variable phase plate

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Light(Science & Applications) 2024年第7期13卷 1354-1363页

作者： Takahiro deguchi Jonas Ries European Molecular Biology Laboratory Cell Biology and BiophysicsHeidelbergGermany. Max Perutz Labs Vienna Biocenter Campus(VBC)ViennaAustria. University of Vienna Center for Molecular BiologyDepartment of Structural and Computational BiologyViennaAustria. University of Vienna Faculty of PhysicsViennaAustria

MINFLUX has achieved extraordinary resolution in superresolution imaging and single fluorophore *** is based on localizing single fluorophores by rapid probing with a patterned beam that features a local intensity *** implementations,however,are complex and expensive and are limited in speed and ***,we show that a combination of an electro-optical modulator with a segmented birefringent element such as a spatial light modulator produces a variable phase plate for which the phase can be scanned on the MHz *** or top-hat phase patterns generate high-contrast compact excitation point-spread functions for MINFLUX localization in the x,y,and z-direction,respectively,which can be scanned across a fluorophore within a microsecond,switched within 60 microseconds and alternated among different excitation *** discuss how to compensate for non-optimal performance of the components and present a robust 3D and multi-color MINFLUX excitation module,which we envision as an integral component of a high-performance and cost-effective open-source MINFLUX.

关键词： excitation phase switched

Three-Dimensional Imaging of Pore-Scale Water Flooding Phenomena in Water-Wet and Oil-Wet Porous Media

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Journal of Flow Control, Measurement & Visualization 2014年第2期2卷 25-31页

作者： Arief Setiawan Tetsuya Suekane yoshihiro deguchi Koji Kusano Department of Energy Sciences Tokyo Institute of Technology Tokyo Japan Department of Mechanical Engineering The University of Tokushima Tokushima Japan

The penetration of water during water flooding has been observed over many years using several methods. A microfocused X-ray computed tomography scanner can be used to directly observe 3D water flooding in a nondestructive manner. To eliminate the possibility of false images being produced because of X-ray broadening effects, we developed a visualization method by arranging the brightness distribution of all phases involved. Water flooding experiments were conducted using oil-wet and water-wet porous media. The water phase was injected upward into packed glass beads containing an oil phase, and the process was scanned every minute until steady state was reached. Using this scheme, real-time, the water invasion pattern and oil trapping process in clusters of pores and individual pores can be observed clearly. By eliminating false images, the boundary of each phase could be identified with high precision, even in a single pore. Porelevel phenomena, including snap off (which has never before been captured in a real 3D porous medium), piston-like displacement, and the curvature of the interface, were also observed. Direct measurement of the pore throat radius and the contact angle between the wetting and nonwetting phases gave an approximation of the capillary pressure during the piston-like displacement and snap-off processes.

关键词： Visualization Porous Medium Pore-Scale Water Flooding Oil Trapping X-Ray CT Scanner