Improvement of the spatial resolution of the spatial mapping of metallic coatings by using picosecond LIBS

Spectrochimica Acta. Part B: Atomic Spectroscopy


Particles influence on the direct absorption spectroscopy of TDLAS


High-resolution microanalysis of steel samples segregation based on picosecond laser-induced breakdown spectroscopy imaging


Application of UVAS and TDLAS-based multi-combustion-parameter diagnosis using computerized tomography


A strategy to reduce spectral intensity uncertainty and predicted content uncertainty of low and medium alloy steel elements


Microstructure classification of steel samples with different heat-treatment processes based on laser-induced breakdown spectroscopy (LIBS)

Journal of Analytical Atomic Spectrometry


Lagrangian identification of coherent structures and mass transport in a buoyant jet diffusion flame


The integration of seawater desalination system with nuclear power plant: Operational flexibility enhancement and thermo-economic performances


On-line Multi-gas Concentration and Temperature Measurement Technology Using Tunable Laser Absorption Spectroscopy

半導体レーザ吸収法を用いた大型燃焼設備のオンラインマルチガス成分・温度計測技術


Analysis of Pulse-to-Pulse Signal Uncertainty in LIBS Spectral Intensity on the Basis of Error Propagation

LIBS 測定におけるスペクトル強度の照射ごとのばらつきの誤差伝播による解析


Qualitative and quantitative analysis of interaction between cavitation patterns and vortices of a pitching hydrofoil from Lagrangian viewpoint


Capturing and Analyzing Coherent Structures in Temporal Streamflow with Complex Networks

Journal of Environmental Accounting and Management


Copper signal characteristics using collinear LS-DP-LIBS for underwater measurement


Spectra-assisted laser focusing in quantitative analysis of laser-induced breakdown spectroscopy for copper alloys


Resolution effects on spectral analysis of low alloy steel by laser-induced breakdown spectroscopy


Rapid Analysis of Steel Powder for 3D Printing Using Laser-Induced Breakdown Spectroscopy


Sulfur Detection in Coke by Laser-Induced Breakdown Spectroscopy


レーザー誘起ブレークダウン分光法の基礎と産業プロセスへの応用

レーザー誘起ブレークダウン分光法の基礎と産業プロセスへの応用


Quantitative analysis of trace carbon in steel samples using collinear long-short double-pulse laser-induced breakdown spectroscopy

Spectrochimica Acta. Part B: Atomic Spectroscopy


LIBS Applications to Steel and Iron Making Processes

LIBSの鉄鋼プロセスへの応用

1．はじめに

鉄鋼プロセスでは，鉄鉱石，コークス，石灰石などを原料として鋼板などを製造する過程で各プロセス中の元素組成を分析することが求められる．特に，溶鋼の段階で鋼材の元素組織を調査するため，溶鋼の組成を迅速に分析・制御することが重要となる．プロセス中で分析を行うために

The Journal of The Institute of Electrical Engineers of Japan


Multi-species hydrocarbon measurement using TDLAS with a wide scanning range DFG laser

Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy


Analysis of critical pipe break sizes leading to reactor pressure vessel liquid level collapse and core uncovery with APROS


レーザー誘起ブレークダウン分光法を用いた遠隔元素組成分析技術の開発

レーザー誘起ブレークダウン分光法を用いた遠隔元素組成分析技術の開発


Applications of TDLAS based multi-species hydrocarbon measurement using a wide scanning range DFG laser


Preliminary Study on 2D Temperature Distribution in Pressure Combustion Field by Using CT-TDLAS


Quantitative analysis of carbon content in fly ash using LIBS based on support vector regression


Quantitative Analysis of Manganese in Underwater Steel Samples Using Long-Short Double-Pulse Laser-Induced Breakdown Spectroscopy

The long-short double-pulse laser-induced breakdown spectroscopy (LS-DP-LIBS) method was applied to qualitative and quantitative analyses of underwater steel samples to improve the detection ability of underwater measurement. The stable plasma intensity and discrete emission lines were detected using LS-DP-LIBS when comparing the measured results of single-pulse LIBS (SP-LIBS) and LS-DP-LIBS. The long pulse produces a cavitation bubble without plasma, and the short pulse induces the plasma of steel samples within the bubble. The detection features of LS-DP-LIBS for underwater steel samples were discussed in different intra-pulse delay time, long-pulse width, and delay time conditions when analyzing the measured spectra, the signal intensity of Fe(I) at 400.524 nm and 402.187 nm, Mn(I) at 404.136 nm, and intensity ratio of Mn(I) 404.136 nm/Fe(I) 402.187 nm. The results indicated that the plasma stability and spectral signal intensity were improved significantly with a long-pulse width of 80 µs in the intra-pulse delay time of 70 µs, which were appropriate for bubble formation and plasma generation. According to the discussion of the delay time effect, the state of generated plasma was almost stable from 650 ns to 850 ns. Manganese (Mn) contents in steel samples were analyzed quantitatively when measuring five steel samples with different Mn contents using LS-DP-LIBS in optimal experimental conditions. A strong linear dependence was observed with =0.9842, which demonstrated the feasibility and appropriateness of quantitative analysis for underwater measurement using LS-DP-LIBS.


Determination of manganese in submerged steel using Fraunhofer-type line generated by long-short double-pulse laser-induced breakdown spectroscopy


Optical temperature measurement method of premixed flames using a multi-laser system

Journal of Mechanical Science and Technology


Study on dynamics of vortices in dynamic stall of a pitching airfoil using Lagrangian coherent structures


Temperature measurement of turbulent flame using CT-TDLAS (computed tomography-tunable diode laser absorption spectroscopy)

International Journal of Modern Physics B


Numerical Study on the Route of Flame-Induced Thermoacoustic Instability in a Rijke Burner


Feasibility of controlling gas concentration and temperature distributions in a semiconductor chamber with the CT-TDLAS

Journal of Vibration Testing and System Dynamics


半導体レーザー吸収法を用いた多種炭化水素成分計測技術の開発

半導体レーザー吸収法を用いた多種炭化水素成分計測技術の開発

Transactions of the Society of Automotive Engineers of Japan


Signal improvement for underwater measurement of metal samples using collinear long-short double-pulse laser induced breakdown spectroscopy


Way-out for laser-induced breakdown spectroscopy


Lagrangian Analysis on Routes of Synthetic Jet to Lift Enhancement of Airfoil and Their Relationships with Jet Parameters


Experimental study on mercury content in flue gas of coal-fired units based on LIBS


Fraunhofer-type signal for underwater measurement of copper sample using collinear long-short double-pulse laser-induced breakdown spectroscopy

Spectrochimica Acta. Part B: Atomic Spectroscopy


Carbon detection in solid and liquid steel samples using ultraviolet long-short double pulse laser-induced breakdown spectroscopy


Feasibility Investigation for Online Elemental Monitoring of Iron and Steel Manufacturing Processes using Laser-Induced Breakdown Spectroscopy


A study on two-dimensional temperature and concentration distribution of Propane-Air premixed fame using CT-TDLAS


Current density effects on plasma emission during Plasma Electrolytic Oxidation (PEO) on AZ91D-Mg alloy


Analysis of mass transport in turbulent flame using Lagrangian coherent structures


Sample temperature effect on steel measurement using SP-LIBS and collinear long-short DP-LIBS


Two dimensional temperature measurement characteristics in pulverized coal combustion field by computed tomography-tunable diode laser absorption spectroscopy


Pulverized Coal Combustion Application of Laser-Based Temperature Sensing System using Computed Tomography - Tunable Diode Laser Absorption Spectroscopy(CT-TDLAS)


Two-dimensional temperature measurement in a high temperature and high pressure combustion using CT-TDLAS with a wide scanning laser at 1335-1375nm

Tunable diode laser absorption spectroscopy (TDLAS) technology is a developing method for temperature and species concentration measurements with the features of non-contact, high precision, high sensitivity, etc. The difficulty of two-dimensional (2D) temperature measurement in actual combustors has not yet been solved because of pressure broadening of absorption spectra, optical accessibility, etc. In this study, the combination of computed tomography (CT) and TDLAS with a wide scanning laser at 1335-1375 nm has been applied to a combustor for 2D temperature measurement in high temperature of 300-2000 K and high pressure of 0.1-2.5 MPa condition. An external cavity type laser diode with wide wavelength range scanning at 1335-1375 nm was used to evaluate the broadened HO absorption spectra due to the high-temperature and high-pressure effect. The spectroscopic database in high temperature of 300-2000 K and high pressure of 0.1-5.0 MPa condition has been revised to improve the accuracy for temperature quantitative analysis. CT reconstruction accuracy was also evaluated in different cases, which presented the consistent temperature distribution between CT reconstruction and assumed distributions. The spatial and temporal distributions of temperature in the high-temperature and high-pressure combustor were measured successfully by CT-TDLAS using the revised spectroscopic database.


Application of 2D temperature measurement for coal-fired furnace using CT-TDLAS


Measurement of 2D temperature distribution of flame using CT-TDLAS


Study on vortex acoustic lock-on behavior in thermoacoustic oscillation involving vortex shedding


Particle Size Measurement of Reaction Product Aerosol of Sodium Oxygen


Measurement Enhancement on Two-Dimensional Temperature Distribution of Methane-Air Premixed Flame Using SMART Algorithm in CT-TDLAS


Measurement of Three-Dimensional Combustion Distribution using CT-TDLAS

Transactions of the Korean Society of Mechanical Engineers, B


Simultaneous Measurement of CH4 Concentration and Temperature Distributions in a Semiconductor Process Chamber


Detection Improvement of Unburned Carbon Content in Fly Ash Flow Using LIBS with a Two-Stage Cyclone Measurement System


Simultaneous two cross-sectional measurements of NH3 concentration in bent pipe flow using CT-tunable diode laser absorption spectroscopy

Journal of Thermal Science and Technology


Unburned carbon measurement in fly ash using laser-induced breakdown spectroscopy with short nanosecond pulse width laser


VALUATION OF 3D MEASUREMENT USING CT-TDLAS


From big to strong: growth of the Asian laser-induced breakdown spectroscopy community


Lagrangian analysis of mass transport and its influence on the lift enhancement in a flow over the airfoil with a synthetic jet


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


Improved Analysis of Manganese in Steel Samples Using Collinear LongShort Double Pulse Laser-Induced Breakdown Spectroscopy (LIBS)


Experimental study on the working states of membrane walls in the arch-fired boiler with different fuel proportion coefficients


Development of receiver optics for simplified 3D laser scanner composition Measurement


Quantitative Elemental Analysis Using Long-Short Double-Pulse Laser-Induced Breakdown Spectroscopy

ロングショートダブルパルスを用いたレーザーブレークダウン分光による元素定量分析

The understanding of the controlling factors is becoming more important to improve the efficiency of industrial systems including steel-making processes, boilers and so on. Laser diagnostics such as laser-induced breakdown spectroscopy (LIBS) makes it possible to monitor these parameters due to their fast response, high sensitivity, and non-contact features. In this study, a new collinear long and short double pulse LIBS method was developed to improve the detection ability and the measurement accuracy by the control of the plasma cooling process using the long pulse-width laser radiation. The plasma generated by the short pulse-width laser is stabilized and maintained at high temperature during the plasma cooling process by long pulse-width laser radiation. The method was demonstrated to have better measurement stability and quantitative measurement characteristics for Manganese and Carbon measurement in the steel samples compared to the normal single pulse LIBS method.

鉄鋼プロセス，ボイラなどの様々な産業プロセスにおいて，物質の元素組成をリアルタイムで計測可能な技術が求められている．鉄鋼プロセスでは，鉄鉱石，コークス，石灰石などを原料として，鋼板などを製造する過程で各プロセス中の成分組成を計測することが求められ，溶融金属の組成などをリアルタイム制御することなどが重要となる．しかし，現在まで，これらの産業プロセスで元素組成をリアルタイムで計測可能な技術や装置は実用化されていない．レーザーを用いた非接触，リアルタイム計測方法として，レーザー誘起ブレークダウン分光法(Laser Induced Breakdown Spectroscopy，LIBS)がある．本研究では，LIBSを用いた元素組成の定量計測を目的に，ロング・ショートダブルパルスLIBSの開発を行った．本手法を鋼材中のマンガン及び炭素計測に適用し，計測の安定性，定量性に優れた特性を有することを実証した．


CH4 Concentration Distribution in a Semiconductor Process Chamber Measured by the CT-TDLAS

ECS Journal of Solid State Science and Technology


Analysis of spectral properties for coal with different volatile contents by laser-induced breakdown spectroscopy

Spectrochimica Acta. Part B: Atomic Spectroscopy


Quantitative Analysis of Unburned Carbon in Fly Ash by Laser-induced Breakdown Spectroscopy


Performance of Flux Switching Integrated Starter-Generator system with dual-mode control circuit

International Journal of Mechatronics and Automation


CT半導体レーザ吸収法を用いたエンジン筒内，排気計測技術

CT半導体レーザ吸収法を用いたエンジン筒内，排気計測技術

Journal of the Society of Instrument and Control Engineers


Enhancement and stabilization of plasma using collinear long-short double-pulse laser-induced breakdown spectroscopy


Performance of AC servo axial-infeed incremental warm rolling equipment and simulated production of spline shafts.

The International Journal of Advanced Manufacturing Technology


Reduction of CO2 effect on unburned carbon measurement in fly ash using LIBS


Evaluation of 3D Measurement Performance of Laser Scanner with Simplified Receiver Optics

Journal of Vibration Testing and System Dynamics


Emission characteristics from laser-induced plasma using collinear long and short dual-pulse LIBS


Raman microspectroscopic detection of thermal denaturation associated with irreversible electroporation

International Journal of Heat and Mass Transfer


CT 半導体レーザー吸収法とその応用

CT 半導体レーザー吸収法とその応用


PERFORMANCES OF NEW RECONSTRUCTION ALGORITHMS FOR CT-TDLAS(COMPUTER TOMOGRAPHY-TUNABLE DIODE LASER ABSORPTION SPECTROSCOPY)


Reaction path and product analysis of sodium-water chemical reactions using laser diagnostics


CT半導体レーザ吸収法を用いたエンジン筒内の2次元時系列温度分布計測

CT半導体レーザ吸収法を用いたエンジン筒内の2次元時系列温度分布計測

Transactions of the Society of Automotive Engineers of Japan


Laser-induced breakdown spectroscopy in Asia


DEVELOPMENT OF FUEL COMPOSITION MEASUREMENT TECHNOLOGY USING LASER DIAGNOSTICS


2D Temperature Measurement of CT-TDLAS by Using Two-Ratios-of-Three-Peaks Algorithm

Transactions of the Korean Hydrogen and New Energy Society


Characteristics of emission from laser-induced plasma of metallic compounds in gaseous condition: the effects of gas pressure and laser pulse energy

Spectroscopy Letters; an International Journal for Rapid Communication


Aplication of Laser-Induced Breakdown Spectroscopy to Real-Time Elemental Monitoring of Iron and Steel Making Processes


レーザ誘起ブレークダウン法を用いた排ガス中の微量成分計測

レーザ誘起ブレークダウン法を用いた排ガス中の微量成分計測

Journal of the Combustion Society of Japan


Developments of a Cross-Correlation Calculation Algorithm for Gas Temperature Distributions Based on TDLAS


CT半導体レーザ吸収法の空間分解能及び精度評価

CT半導体レーザ吸収法の空間分解能及び精度評価


Development of self-motivating education method using intellectual property rights

知的財産を用いた自主的創造力創出教育

Journal of the Japan Society for Abrasive Technology


VALIDATION OF THE REAL-TIME 2D TEMPERATURE MEASUREMENT METHOD USING THE CT TUNABLE DIODE LASER ABSORPTION SPECTROSCOPY


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


Improved Measurement Characteristics of Elemental Compositions Using Laser-Induced Breakdown Spectroscopy


Sensitive Cesium Measurement in Liquid Sample Using Low Pressure Laser-Induced Breakdown Spectroscopy

Spectrochimica Acta. Part B: Atomic Spectroscopy


Time resolved 2D concentration and temperature measurement using CT tunable laser absorption spectroscopy


High temperature field application of two dimensional temperature measurement technology using CT tunable laser absorption spectroscopy


2D Temperature Detection Characteristics of Engine Exhaust Gases Using CT Tunable Diode Laser Absorption Spectroscopy

International Journal of Mechanical Systems Engineering


CT半導体レーザ吸収法を用いた高温・高圧域における2次元温度分布計測の特性評価

CT半導体レーザ吸収法を用いた高温・高圧域における2次元温度分布計測の特性評価

Transactions of the Society of Automotive Engineers of Japan


Real-time 2D Concentration Measurement of CH4 in Oscillating Flames Using CT Tunable Diode Laser Absorption Spectroscopy


Breakdown pattern of hydrocarbons by laser breakdown time-of-flight mass spectrometry

Spectroscopy Letters; an International Journal for Rapid Communication


Comparison of the Detection Characteristics of Trace Species Using Laser-Induced Breakdown Spectroscopy and Laser Breakdown Time-of-Flight Mass Spectrometry


Experimental and Numerical Reaction Analysis on Sodium-Water Chemical Reaction Field

In a sodium-cooled fast reactor (SFR), liquid sodium is used as a heat transfer fluid because of its excellent heat transport capability. On the other hand, it has strong chemical reactivity with water vapor. One of the design basis accidents of the SFR is the water leakage into the liquid sodium flow by a breach of heat transfer tubes. This process ends up damages on the heat transport equipment in the SFR. Therefore, the study on sodium-water chemical reactions is of paramount importance for security reasons. This study aims to clarify the sodium-water reaction mechanisms using an elementary reaction analysis. A quasi one-dimensional flame model is applied to a sodium-water counter-flow reaction field. The analysis contains 25 elementary reactions, which consist of 17 H2-O2 and 8 Na-H2O reactions. Temperature and species concentrations in the counter-flow reaction field were measured using laser diagnostics such as LIF and CARS. The main reaction in the experimental conditions is Na+H2O→NaOH+H and OH is produced by H2O+H→H2+OH. It is demonstrated that the reaction model in this study well explains the structure of the sodium-water counter-flow diffusion flame.


Improvement on quantitative measurement of fly ash contents using laser-induced breakdown spectroscopy

Journal of Flow Control Measurement & Visualization


Applications of laser diagnostics to thermal power plants and engines


Applications of laser-induced breakdown spectroscopy and laser breakdown time-of-flight mass spectrometry to thermal power plants


Measurement Accuracy Evaluation of Two Dimensional Concentration Measurement Technology Using CT Tunable Laser Absorption Spectroscopy

CT半導体レーザ吸収法を用いた2次元濃度計測の精度評価


Evaluation of Two Dimensional Temperature Measurement Technology in High Temperature Condition Using CT Tunable Laser Absorption Spectroscopy

CT半導体レーザ吸収法を用いた高温域における2次元温度分布計測の特性評価


Rapid detection of mercury and iodine using laser breakdown time-of-flight mass spectrometry

Spectroscopy Letters; an International Journal for Rapid Communication


Effect of heterogeneity of porous media on gas permeation and entrapment


Three-dimensional imaging of pore-scale water flooding phenomena in water-wet and oil-wet porous media


Pore-scale investigation of the effect of connate water on water flooding behavior

Water flooding is one of the most important processes in oil production. Water is injected into an oil reservoir to maintain the reservoirs pressure and sweep some of the oil toward the production well. In an actual oil reservoir, in situ water, or connate water, is usually present and significantly impacts the water flooding process. We developed a visualization scheme utilizing a microfocused X-ray CT scanner to three-dimensionally observe the effects of connate water during water flooding at the pore scale. The water phase was injected upward into packed glass beads containing an oil phase both with and without connate water, and the process was scanned every minute until steady state was reached. Three-dimensional images were then constructed from X-ray CT data to clearly show the phenomena. Connate water significantly reduces oil recovery. In the porous medium without connate water, water flooding was able to produce approximately 1.5 times more oil than in the medium with connate water because of steadier interface movement. When injected water came in contact with connate water, the displacement front suddenly expanded into the pores containing connate water, thereby creating a jump-like movement leading to fingering. The pressure gradient between the inlet and outlet forced water to select the shortest route to the outlet. Water reached the outlet earlier when connate water exists. Short-circuiting due to fingering leads to formation of entrapped oil pockets and oil recovery yields.


Sensitive detection of iodine by low pressure and short pulse laser-induced breakdown spectroscopySensitive (LIBS)

Journal of Analytical Atomic Spectrometry


Accuracy Verification on 2D Temperature Measurement Method Using CT-tunable Diode Laser Absorption Spectroscopy

CT半導体レーザ吸収法を用いた2次元温度計測の精度検証

Transactions of the Society of Automotive Engineers of Japan


CT半導体レーザ吸収法を用いたNH3の2次元濃度計測

CT半導体レーザ吸収法を用いたNH3の2次元濃度計測


Application of Laser Diagnostics to Sodium-Water Chemical Reaction Field


Sensitive measurement of trace mercury using low pressure laser-induced plasma

Japanese Journal of Applied Physics, Part 1 (Regular Papers & Short Notes)


Enhancement of laser-induced breakdown spectroscopy(LIBS) detection limit by low pressure and short pulse laser-induced plasma process

Laser-induced breakdown spectroscopy (LIBS) technology is an appealing technique compared with many other types of elemental analysis because of the fast response, high sensitivity, real-time, and noncontact features. One of the challenging targets of LIBS is the enhancement of the detection limit. In this study, the detection limit of gas-phase LIBS analysis has been improved by controlling the pressure and laser pulse width. In order to verify this method, low-pressure gas plasma was induced using nanosecond and picosecond lasers. The method was applied to the detection of Hg. The emission intensity ratio of the Hg atom to NO (IHg/INO) was analyzed to evaluate the LIBS detection limit because the NO emission (interference signal) was formed during the plasma generation and cooling process of N2 and O2 in the air. It was demonstrated that the enhancement of IHg/INO arose by decreasing the pressure to a few kilopascals, and the IHg/INO of the picosecond breakdown was always much higher than that of the nanosecond breakdown at low buffer gas pressure. Enhancement of IHg/INO increased more than 10 times at 700 Pa using picosecond laser with 35 ps pulse width. The detection limit was enhanced to 0.03 ppm (parts per million). We also saw that the spectra from the center and edge parts of plasma showed different features. Comparing the central spectra with the edge spectra, IHg/INO of the edge spectra was higher than that of the central spectra using the picosecond laser breakdown process.


Two Dimensional Temperature Measurement Using CT Tunable Laser Diode Absorption Spectroscopy

CT 半導体レーザ吸収法による 2 次元温度計測

2D temperature and concentration distribution plays an important role for the combustion structure and the combustor efficiency in engines, burners, gas turbines and so on. 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) technique using absorption spectra of water vapor at 1388nm. The CT tunable diode laser absorption spectroscopy method was applied to a burner and engine exhausts to measure 2D temperature distributions using 8-path, 12-path, and 16-path CT cells and the accuracy and the special resolution of this method was discussed compared with the measurement results of a thermocouple. Since CT tunable diode laser absorption spectroscopy has a potential of the kHz response time, this method enables the real-time 2D temperature measurements to be applicable in various industrial processes including engine applications.

Journal of the Combustion Society of Japan


Quantitative elemental detection of size-segregated particles using laser-induced breakdown spectroscopy

Spectrochimica Acta. Part B: Atomic Spectroscopy


Laser wavelength and pressure dependence of laser breakdown time-of-flight mass spectrometry


Rapid detection of trace heavy metals using laser breakdown time-of-flight mass spectrometry


Application of 2D Temperature Measurement Method Using Tunable Diode Laser Absorption Spectroscopy with CT to Engine Exhausts

CT利用半導体レーザ吸収法によるリアルタイム2次元温度計測のエンジン排ガスへの適用

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. 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 method using absorption spectra of water vapor at 1388nm. It has been demonstrated that the method has been successfully applied to engine exhausts to measure 2D temperature distributions.

エンジン排気ガス温度分布を明らかにすることは燃焼器改善において重要となる．本研究では，半導体レーザ吸収法とCT(ComputedTomography)を組合せたkHz レベルの2 次元温度計測技術を開発した．本技術をエンジン排ガスに適用し，高応答で温度分布を捉えることができることを実証した．


Development of Tunable diode laser absorption spectroscopy with optical follow fiber and NOx measurement by UV Tunable diode laser absorption

中空ファイバ利用半導体レーザ吸収法の開発と紫外域半導体レーザ吸収法を用いたNOx計測

Recent years have already seen tighter regulation on harmful substances such as NOx, CO and CO2. In car engines an increasing concern in environmental issues such as air pollution, global warming and petroleum depletion has helped drive researches into various ways. 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 using the hollow fiber has been developed to satisfy above requirements. A sensitive method using tunable UV diode laser absorption spectroscopy was also discussed to detect NOx in exhausts.

エンジン排ガスに含まれるNOxなどの排出量を抑える為には燃焼プロセスをリアルタイムで把握する事が重要である．本研究では，中空ファイバを用いた半導体レーザ吸収法による高感度・高応答排ガス成分計測技術を開発すると共に，感度の高い紫外域半導体レーザ吸収法を用いたNOx計測の可能性を検討した．

Transactions of the Society of Automotive Engineers of Japan


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

Journal of Mechanics Engineering and Automation


Questionnaire research and development of self-motivating education method using intellectual property rights

International Journal of Engineering Pedagogy (iJEP)


Development of 2D temperature and concentration measurement method using tunable diode laser absorption spectroscopy


Elementary Reaction Analysis on Sodium-Water Chemical Reaction Field

ナトリウム-水化学反応場の素反応解析

In a sodium-cooled fast reactor (SFR), liquid sodium is used as a heat transfer fluid because of its excellent heat transport capability. On the other hand, it has strong chemical reactivity with water vapor. One of the design basis accidents of the SFR is the water leakage into the liquid sodium flow by a breach of heat transfer tubes. This process ends up damages on the heat transport equipment in the SFR. Therefore, the study on sodium-water chemical reactions is of paramount importance for security reasons. This study aims to clarify the sodium-water reaction mechanisms using an elementary reaction analysis. A quasi one-dimensional flame model is applied to a sodium-water counter-flow reaction field. The analysis contains 25 elementary reactions, which consist of 17 H2-O2 and 8 Na-H2O reactions. Temperature and species concentrations in the counter-flow reaction field were measured using laser diagnostics such as LIF and CARS. The main reaction in the experimental conditions is Na+H2O→NaOH+H, and OH is produced by H2O+H→H2+OH. It was demonstrated that the reaction model in this study well explains the structure of the sodium-water counter-flow diffusion flame.

Transactions of The Japan Society of Mechanical Engineers, Series B

日本機械学会論文集(B編)


Numerical Simulation of Laser Induced Weakly Ionized Helium Plasma Process by Lattice Boltzmann Method

Generation process of laser induced weakly ionized helium plasma is simulated using the lattice Boltzmann method (LBM). Maxwell equations, which are used to model the propagation of laser, are calculated by the finite difference time domain (FDTD) method. Employing coefficients of distribution functions, processes of multi-photon ionization, electron impact ionization and three-body recombination are included in Boltzmann equations. Using D2Q9 model in LBM, number densities of particles in plasma can be obtained after solving Boltzmann equations. For the energy transformation in plasma, the finite volume method (FVM) is applied to calculate the macroscopic energy equations directly coming from the continuous Boltzmann equations. Interaction between laser and plasma as well as laser induced weakly ionized plasma are demonstrate to validate the hybrid model.

Japanese Journal of Applied Physics, Part 1 (Regular Papers & Short Notes)


知的財産立国を目指した自主的創造力創出教育について― 青色発光ダイオード発祥の地 徳島での現状とこれからの取り組み ―


Numerical Prediction and Optimization of Depressurized Sodium-Water Reaction Experiment with Counterflow Diffusion Flame

Journal of Engineering for Gas Turbines and Power


Detection of components in nanoparticles by resonant ionization and laser breakdown time-of flight mass spectroscopy


Development of Direct and Fast Response Exhaust Gas Measurement


Development of Direct and High Response Gas Measurement

自動車エンジンにおける直接・高応答ガス計測技術開発

Transactions of the Society of Automotive Engineers of Japan


Environmental Monitoring Method of Di-, Tri-, Tetra-, Penta-, and Hexa-Chlorinated Biphenyls in the Gas Phase by Use of the Picosecond Laser Ionization

Utilization of the picosecond (100 ps) laser ionization was successful in measuring the mass spectra attributed to di-, tri-, tetra-, penta-, and hexa-chlorinated biphenyls. It was confirmed that the quantitative limit of this method in real-time (1 min) was 10 μg/m3N (equivalent to 1/10 of the value established as the statutory limit for PCBs in the ambient air of the workplace environment). Further evaluations of measurement accuracy based on comparisons with the results of the conventional method (gas sampling and GC-MS) demonstrated a coefficient of variation within 30%. We undertook the measurement of the exhaust gas and the work environment atmosphere in PCBs treatment plants using the LI-IT-TOFMS method, confirming that the monitoring system could be operated appropriately by the introduction of an internal standard gas (2,4-dichlorinated toluene), and that it was possible to make continuous long-term measurements for over 500 h (total measurement time, >6000 h).

Journal of Chemical Engineering of Japan


Development of Heat Input Estimation Technique for Simulation of Shell Forming by Line-Heating

Computer Modeling in Engineering & Sciences


Laser Mass Spectrometry: Rapid Analysis of Polychlorinated Biphenyls in Exhaust Gas of Disposal Plants

Effective prevention from the leakage of Polychlorinated Biphenyls (PCBs) requires the rapid analysis with on-line detection, but conventional methods require extensive analytical time (several days per sample) and are thus unsuitable. The objective of the research reported here was to develop the Laser Ionization / Ion Trap Storage / Time of Flight Mass Spectrometry (LI-IT-TOFMS) capable of monitoring PCBs within 1 min/sample, as applied to exhaust gas and the atmosphere of the disposal work environment. The achievable PCBs sensitivity for on-line measurement was found to be in the pptV range (< 0.01 mg/m3N) by means of comparison with conventional gas sampling and gas chromatograph - mass spectrometry (GC-MS). A satisfactory proportional relationship was confirmed between laser-based and conventional results for PCBs. We measured the exhaust gas in a PCBs treatment plant (hydrothermal decomposition and container treatment processes) by using the PCBs monitoring system, confirming that PCBs monitoring is possible without interference from either the main gas composition or minor coexisting substances. Accordingly, the LI-IT-TOFMS method is a useful method for the trace analysis of PCBs in exhaust gas.


LIBSを用いた微量重金属成分モニタリング技術の開発

LIBSを用いた微量重金属成分モニタリング技術の開発

Exhaust gas regulations for harmful components have been established in most countries of the world. In order to establish reduction technology for harmful components in exhaust gas, technology is required for the real-time detection of trace heavy metal components. In this paper, a method for the detection of trace heavy metal components using laser induced breakdown spectroscopy (LIBS) was examined with respect to powder and gas phase samnles. Detection characteristics were obtained for Pb and Cr in real ash, and measurement sensitivity under 500 mg/kg was confirmed, Detection characteristics were also obtained for As, Be, Cd, Co, Cr, Hg, Mn, Ni, Pb, Se, and Sb in gas, and measurement sensitivity under 0.1 mg/Nm^3 was confirmed for these elements, except for As and Se. Future use of high sensitivity techniques is expeded to reach a sensitivity level under 0.1 mg/Nm^3 for As and Se.

Transactions of The Japan Society of Mechanical Engineers, Series C

日本機械学会論文集(C編)


Determination of organic compounds in nano-particles by laser breakdown and resonant ionization time-of-flight mass spectrometry

Spectrochimica Acta. Part B: Atomic Spectroscopy


On-line monitoring method of PCBs by laser ionization dynamic trapping time of flight mass spectrometry(<Special Article>Environmental Analysis of Island Surrounded with Sea and Sky)

レーザーイオン化ダイナミックトラップ飛行時間型質量分析法によるポリ塩化ビフェニル類の迅速分析

The emissions of organic hazards from environmental protection equipments and other facilities have become a major social issue, and the evaluation of toxicity concentration requires methods having both high precision and high chemical selectivity. LI-IT-TOFMS (laser ionization/ion trap storage/time of flight mass spectrometry) is expected to be a powerful tool for environmental monitoring. This report, discusses real-time LI-IT-TOFMS measurements gaseous 2∼4 chlorinated PCBs in order to evaluate the applicability of the environmental monitoring method. With respect to the effect of ion trap storage for PCBs, we found that it was due to the driving RF voltage on the ring electrode in the ion trap. For the ions of PCBs produced by laser irradiation, we observed that it was more efficient to reach the center of the ion trap by using a gated RF voltage rather than by using a continuous RF voltage. We simulated the ion trajectories in the ion trap by using SIMION 7.0. We found that the voltage of the exit end cap electrode affected both the number of ions trapped and the orbit of ions inside of the trap cell. Optimization of this parameter was performed using both simulated and experimental results. The achievable PCB sensitivity for real-time (1 minute) measurements using the LI-IT-TOFMS technique was found to be in the pptV range (<0.01 mg/Nm^3) by a comparison with the conventional gas sampling GC/MS method. A satisfactory proportional relationship was confirmed between laser-based and conventional results. In the future we will pursue the method for environmental monitoring.

有機ハロゲン化物排出などによる環境汚染が社会問題化している中,オンラインで微量濃度監視(モニタリング)する手法の確立が強く望まれている.その有力な方法のひとつとして,ダイナミックトラップ飛行時間型質量分析(TOFMS)法を適用した結果について報告する.本法はガス直接導入式レーザーイオン化TOFMS技術にイオントラップ濃縮技術を付加した手法である.レーザーイオン化されたイオンを効率的に捕捉する手法として,ダイナミックトラップ法が有用であることを確認した.更なる高感度化のためイオン軌道シミュレーションを実施した.その結果,イオントラップ内に入るイオンを減速させる方法の有効性を確認した.シミュレーションで得た知見を実験にて検証し,ポリクロロビフェニル(PCB)類が計測時間1分でpptVレベルの感度で計測可能を確認した.今後,環境モニタリング手法としての適用性を実証していく予定である.


エンジン排ガス中ナノ粒子の化学成分計測技術

エンジン排ガス中ナノ粒子の化学成分計測技術

Journal of the Combustion Society of Japan


レーザイオン化TOFMS法を用いたPCBモニタリング技術開発

レーザイオン化TOFMS法を用いたPCBモニタリング技術開発

This study demonstrates the applicability of PCB monitoring using laser ionization time of flight mass spectrometry. Picosecond 266 nm laser light ionization reduced fragmentation, with PCB detection sensitivity under ppbv (∼μg/Nm^3) that can be achieved in one minute detection time. This has great advantages in terms of real time monitoring ability compared to the conventional method, which requires several days analysis time. A prototype of the PCB monitoring device has been developed and tested in Mitsubishi Heavy Industries' PCB treatment plant. The one-minute detection time represents a substantial advance in the monitoring of exhaust gas and in compliance with safety regulations in the atmosphere surrounding work areas where PCB vessels are dismantled.

日本機械学会論文集(C編)


Real-Time Measurements of Polychlorinated Biphenyls Using Laser Ionization Rime-of-Flight Mass Spectroscopy

Polychlorinated biphenyls (PCBs) are hazardous compounds for which there are few methods involving real-time measurement. Recently, the development of the pulsed-laser technique has enabled us to measure aromatic hydrocarbons quite rapidly. In particular, the LI-TOFMS (laser ionization time of flight mass spectrometry) technique is expected to be a powerful method for on-line, selective and sensitive measurements. In the context of developing a highly selective and sensitive technique, the effective laser wavelength and pulse duration for laser ionization of 2-4 chlorinated PCBs are considered. Excitation at lambda = 266 nm was found to be substantially more effective than at lambda = 280, 300 or 320 nm. Also, picosecond excitation for PCBs underwent more efficient ionization (by a factor of over 10) and less fragmentation than nanosecond excitation. The achievable sensitivity for trichlorinated biphenyl in a real-time (1 min) measurement using the LI-TOFMS technique was estimated to be in the sub-ppbV range (< 0.01 mg/Nm3).


Real-Time Measurement of Polychlorinated Biphenyls Using Laser lonization Time of Flight Mass Spectroscopy

レーザイオン化TOFMSによるPCBリアルタイム計測技術

Polychlorinated biphenyls (PCBs) are environmental chemicals and there are few methods for real-time PCB measurement. This study demonstrates the applicability of the real-time measurement of PCBs using LI-TOFMS (Laser Ionization Time of Flight Mass Spectroscopy). In order to develop a highly selective and sensitive method, the effective laser wavelength and pulse width for laser ionization of PCBs are discussed. Excitation at λ=266nm is found to be substantially more effective than at λ=280, 300 or 320nm. Also picosecond excitation for PCBs undergoes more efficient ionization (by a factor of over 10) and less fragmentation than nanosecond excitation. The achievable trichlorinated biphenyl sensitivity for real-time (1min) measurement using the LI-TOFMS technique is determined to be in the sub-ppbV range (<0.01mg/Nm^3).

日本機械学会論文集(C編)


Optimal Boiler Control through Real-time Monitoring of Unburned Carbon in Fly Ash Using Laser Induced Breakdown Spectroscopy

A laser-induced breakdown spectroscopy (LIBS) technique has been applied for detection of unburned carbon in fly ash, and an automated LIBS unit has been developed and applied in a 1000-MW pulverized-coal-fired power plant for real-time measurement, specifically of unburned carbon in fly ash. Good agreement was found between measurement results from the LIBS method and those from the conventional method (Japanese Industrial Standard 8815), with a standard deviation of 0.27%. This result confirms that the measurement of unburned carbon in fly ash by use of LIBS is sufficiently accurate for boiler control. Measurements taken by this apparatus were also integrated into a boiler-control system with the objective of achieving optimal and stable combustion. By control of the rotating speed of a mill rotary separator relative to measured unburned-carbon content, it has been demonstrated that boiler control is possible in an optimized manner by use of the value of the unburned-carbon content of fly ash.


Real Time PCB Monitoring Using Time of Flight Mass Spectrometry with Picosecond Laser Ionization

The study demonstrates the applicability of laser ionization time-of-flight mass spectrometry for real-time measurement of polychlorinated biphenyls (PCBs). Picosecond 266-nm laser light ionization reduced fragmentation and provided very high PCB detection sensitivity. This high sensitivity has advantages in terms of real-time monitoring capability as compared to the conventional GC-ECD or GC-MS methods, which require at least several days for the analysis of PCBs. Detection sensitivity of under 0.01 mg/Nm3 was achieved with a 1-min measuring time; this sensitivity is superior to the exhaust gas control guideline of 0.15 mg/Nm3 by a factor of 10. A prototype PCB monitoring device has been developed and tested in a pilot PCB treatment plant. The 1-min detection time represents a substantial advance in the monitoring of exhaust gas and the workplace atmosphere in accordance with safety regulations.


Optical Analysis of Homogeneous Charge Compression Ignition Combustion

予混合圧縮自着火燃焼についての光学的解析

In this study, we applied luminous spectroscopic analysis and Planar Laser Induced Fluorescence (PLIF) method on lean Homogeneous Charge Compression Ignition (HCCI) combustion to obtain some ideas of ignition timing control and combustion rate control methods in HCCI engines. In the tests, we used an optical access engine and n-C_<12>H_<26> as a fuel. Inlet air temperatures and inlet oxygen concentrations were changed as the test parameters, and the following conclusions were obtained : (1) After low temperature reaction, LIF signal from hydrocarbon was disappeared. This was because that hydrocarbon was changed to another molecules or per oxides. (2) In high temperature reaction region, OH radical was appeared across a wide area in the combustion chamber.

Transactions of The Japan Society of Mechanical Engineers, Series B

日本機械学会論文集(B編)


Optimal Boiler Control by Real-time Monitoring of Unburned Carbon in Fly Ash

フライアッシュ未燃分リアルタイム計測によるボイラ最適制御の実証


Improvement of Combustion Control through Real-time Measurement of O2 and CO Concentrations in Incinerators Using Diode Laser Absorption Spectroscopy


Industrial Applications of Temperature and Species Concentration Monitoring Using Laser Diagnostics


Detection of carbon content in a high-temperature and high-pressure environment using laser-induced breakdown spectroscopy

Spectrochimica Acta. Part B: Atomic Spectroscopy


レーザ分光法による微量成分計測

レーザ分光法による微量成分計測


ディーゼル噴霧火炎内のNO瞬時二次元計測

ディーゼル噴霧火炎内のNO瞬時二次元計測

Journal of Society of Automotive Engineers of Japan


線状加熱における燃焼場から鋼板への熱移動に関する研究(その3)

線状加熱における燃焼場から鋼板への熱移動に関する研究(その3)


LIF Applications for Practical Combustors


線状加熱における燃焼場から鋼板への熱移動に関する研究(その2)

線状加熱における燃焼場から鋼板への熱移動に関する研究(その2)


極超音速流れ場中の基本物体周りの温度場のLIF計測

極超音速流れ場中の基本物体周りの温度場のLIF計測


微粉炭燃焼モデルと燃焼診断技術

微粉炭燃焼モデルと燃焼診断技術


ディーゼル噴霧火炎内のNO瞬時二次元計測

ディーゼル噴霧火炎内のNO瞬時二次元計測


NO Measurement in Diesel Spray Flame Using Laser Induced Fluorescence


LIFによる定量計測ならびに超音速横断流中の噴流への適用

LIFによる定量計測ならびに超音速横断流中の噴流への適用

Journal of the Japan Society for Aeronautical and Space Sciences


レーザ誘起蛍光法によるガスタービン燃焼器内のOH，NO計測

レーザ誘起蛍光法によるガスタービン燃焼器内のOH，NO計測

日本機械学会論文集(B編)


極超音速衝撃風洞とレーザ誘起蛍光法による温度・濃度場の計測

極超音速衝撃風洞とレーザ誘起蛍光法による温度・濃度場の計測


水素乱流拡散火炎におけるOHラジカル計測

水素乱流拡散火炎におけるOHラジカル計測


水蒸気とアセチレンのCARSシミュレーション

水蒸気とアセチレンのCARSシミュレーション


ラマン散乱法を用いたアセチレンの温度・濃度計測

ラマン散乱法を用いたアセチレンの温度・濃度計測


レーザ誘起蛍光法を用いたOHの温度・濃度計測

レーザ誘起蛍光法を用いたOHの温度・濃度計測


レーザ誘起ブレークダウン分光法を用いた溶鋼リアルタイム分析技術の開発

レーザ誘起ブレークダウン分光法を用いた溶鋼リアルタイム分析技術の開発


四国支部と四国地域の知財について

四国支部と四国地域の知財について


Education to generate independent creativity using intellectual property

知的財産を用いた自主的創造力創出教育について― パテント/デザインパテントコンテストの大学教育への活用 ―


Development of self-motivating education method using intellectual property rights : Utilization of Patent and Design-Patent Contests for university education


防腐・防蟻剤(CCA)処理木材の選別について

防腐・防蟻剤(CCA)処理木材の選別について


Plant and Environmental Monitoring Techniques Using State-of-the-art Laser Diagnostics

Mitsubishi Heavy Industries, Ltd. Technical Review


最先端レーザ応用技術を用いたプラント・環境計測

最先端レーザ応用技術を用いたプラント・環境計測


Real-time PCB gas monitoring system (MOHMS-21GP)


レーザイオン化TOFMS法によるガス中のPCBモニタリング装置開発

レーザイオン化TOFMS法によるガス中のPCBモニタリング装置開発

環境システム計測制御学会誌

環境システム計測制御学会誌


最先端レーザ応用計測技術を用いたガス中PCBリアルタイムモニタリング技術の開発

最先端レーザ応用計測技術を用いたガス中PCBリアルタイムモニタリング技術の開発

月間地球環境 2003.3,企画特集1 活性化するPCB廃棄物処理

月間地球環境 2003.3,企画特集1 活性化するPCB廃棄物処理


ごみ焼却炉内CO，O2濃度リアルタイム計測による燃焼制御の高度化技術

ごみ焼却炉内CO，O2濃度リアルタイム計測による燃焼制御の高度化技術


極超音速流れ中の球及びくさび周りの温度場のLIF計測

極超音速流れ中の球及びくさび周りの温度場のLIF計測


LIBSによるオンライン成分検出システムの開発

LIBSによるオンライン成分検出システムの開発


Laser Induced Fluorescence Fires Up Engine Research


レーザ誘起蛍光法の実用燃焼場への応用技術開発

レーザ誘起蛍光法の実用燃焼場への応用技術開発


Application of Laser Induced Fluorescence to Practical Combustion Fields


レーザ誘起蛍光法の燃焼解析への応用

レーザ誘起蛍光法の燃焼解析への応用


Application of Laser Induced Fluorescence to Combustion Analysis


CARS Application to Simultaneous Two Species Concentration Measurement of Ammonia-Water Vapor Mixture


CARSによるアンモニア・水混合蒸気の同時二成分濃度計測法

CARSによるアンモニア・水混合蒸気の同時二成分濃度計測法