Journal articles: 'Laser tracer'

1

MAJIMA, TETSURO. "Laser Separation of Tracer Isotopes." RADIOISOTOPES 43, no. 9 (1994): 577–78. http://dx.doi.org/10.3769/radioisotopes.43.9_577.

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2

Song, Huixu, Hongfang Chen, and Zhaoyao Shi. "A Simple Integrated Geometrical Error Model for Laser Tracer." MATEC Web of Conferences 208 (2018): 03006. http://dx.doi.org/10.1051/matecconf/201820803006.

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Geometrical errors of 2D gimbal mount axes are studied for laser tracer for the sake of realizing rapid detection for numerical control equipment. The high precision reference sphere, which serves as the reflection unit and is set on the base, avoids the influence on measurement accuracy caused by the movements of rotatory axes, and ensures that laser tracer owns large tracing angle. The nonlinear coupling relationship between the geometrical errors and the measurement accuracy of laser tracer is analyzed; the integrated geometrical error model of 2D gimbal mount axes and laser interferometry system is established; the error map of the measuring system is brought. The simulation results demonstrate that the measurement error of the laser tracer is certain and unique after the value and direction of all the geometrical errors determined.

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3

Chen, Hongfang, Bo Jiang, Hu Lin, Shuang Zhang, Zhaoyao Shi, Huixu Song, and Yanqiang Sun. "Calibration Method for Angular Positioning Deviation of a High-Precision Rotary Table Based on the Laser Tracer Multi-Station Measurement System." Applied Sciences 9, no. 16 (August 19, 2019): 3417. http://dx.doi.org/10.3390/app9163417.

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This paper proposes a calibration method for angular positioning deviation of a high-precision rotary table based on the laser tracer multi-station measurement system. The algorithm error of the calibration method for angular positioning deviation of a high-precision rotary table based on the laser tracer multi-station measurement system was mainly discussed. During the experiments, the laser tracer was fixed on the work surface of the rotary table, and the rotary was fixed on the work surface of the coordinate measurement machine (CMM). The rotary table was rotated with the same angular interval. In this case, an optimization method for calculating the coordinates of a laser tracer station by using Levenberg–Marquardt algorithm and singular value decomposition transform was proposed. Then, the angular positioning deviation of the rotary table was calibrated by an established geometric relationship model between the coordinates of laser tracer stations and the rotation angle of the rotary table. The angular positioning deviation of the high-precision rotary table was as low as ±0.9″, and the error of the calibration method was ±0.4″. The experimental results proved the feasibility of the proposed calibration method. The calibration method proposed in this paper is suitable for the case that the rotary table is not linked with the CMM, especially for large high-precision rotary tables.

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KOLB, C. E., J. B. McMANUS, D. D. NELSON, J. C. WORMHOUDT, and M. S. ZAHNISER. "MID-INFRARED TUNABLE LASER ENVIRONMENTAL TRACER SPECIES MEASUREMENT." Optics and Photonics News 7, no. 9 (September 1, 1996): 34. http://dx.doi.org/10.1364/opn.7.9.000034.

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5

Hartwig, Jason, Gaurav Mittal, Kamal Kumar, and Chih-Jen Sung. "System Validation Experiments for Obtaining Tracer Laser-Induced Fluorescence Data at Elevated Pressure and Temperature." Applied Spectroscopy 72, no. 4 (December 27, 2017): 618–26. http://dx.doi.org/10.1177/0003702817746409.

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This paper presents a set of system validation experiments that can be used to qualify either static or flow experimental systems for gathering tracer photophysical data or conducting laser diagnostics at high pressure and temperature in order to establish design and operation limits and reduce uncertainty in data interpretation. Tests demonstrated here quantify the effect of tracer absorption at the test cell walls, stratification, photolysis, pyrolysis, adequacy of mixing and seeding, and reabsorption of laser light using acetone as the tracer and 282 nm excitation. Results show that acetone exhibits a 10% decrease in fluorescence signal over 36 000 shots at 127.4 mJ/cm2, and photolysis is negligible below 1000 shots collected. Meanwhile, appropriately chosen gas residence times can mitigate risks due to pyrolysis and inadequate mixing and seeding; for the current work 100 ms residence time ensured <0.5% alteration of tracer number density due to thermal destruction. Experimental results here are compared to theoretical values from the literature.

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6

OZAWA, Yasumi, and Noriyuki YANAGAWA. "The Measurement of Tracer Adhesion Position in the Tracer Method by Laser Focus Displacement Gage." Journal of the Visualization Society of Japan 21, no. 2Supplement (2001): 65–66. http://dx.doi.org/10.3154/jvs.21.2supplement_65.

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7

Koegl, Matthias, Christopher Mull, Kevin Baderschneider, Jan Wislicenus, Stefan Will, and Lars Zigan. "Characterization of Nile Red as a Tracer for Laser-Induced Fluorescence Spectroscopy of Gasoline and Kerosene and Their Mixture with Biofuels." Sensors 19, no. 12 (June 24, 2019): 2822. http://dx.doi.org/10.3390/s19122822.

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Suitable fluorescence tracers (“dyes”) are needed for the planar measurement of droplet sizes by using a combination of laser-induced fluorescence (LIF) and Mie scattering. Currently, no suitable tracers have been characterized for application in planar droplet sizing in gasoline and kerosene fuels, as well as biofuel blends. One promising tracer is nile red, which belongs to the fluorophore group. For its utilization for droplet size measurements, preliminary characterization of the fluorescence of the respective fuel tracer mixtures are mandatory. For this purpose, the fluorescence and absorption behavior of nile red dissolved in the surrogate fuels Toliso and Jet A-1 as well as in biofuel blends was investigated. The fluorescence signal for nile red that was dissolved in the two base fuels Toliso and Jet A-1 showed a linear behavior as a function of dye concentration. The temperature effect on spectral absorption and emission of nile red was investigated in a specially designed test cell. An ethanol admixture to Toliso led to a spectral shift towards higher wavelengths. The absorption and emission bands were shifted towards lower wavelengths with increasing temperature for all fuels. Both absorption and fluorescence decreased with increasing temperature for all fuels, except for E20, which showed an increased fluorescence signal with increasing temperature. Jet A-1 and its blends with hydroprocessed esters and fatty acids (HEFA) and farnesane did not exhibit explicit variations in spectral absorption or emission, but these blends showed a more distinct temperature dependence compared to the Toliso-ethanol-blends. The effect of photo-dissociation of the LIF signal of the fuel tracer mixtures was studied, and all fuel mixtures besides Toliso showed a more or less distinct decay in the fluorescence signal with time. In summary, all investigated fuel-tracer mixtures are suitable for LIF/Mie ratio droplet sizing in combination with nile red at moderate temperatures and low evaporation cooling rates.

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8

Gisel, A., S. Barella, F. D. Hempel, and P. C. Zambryski. "Temporal and spatial regulation of symplastic trafficking during development in Arabidopsis thaliana apices." Development 126, no. 9 (May 1, 1999): 1879–89. http://dx.doi.org/10.1242/dev.126.9.1879.

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Plasmodesmata provide symplastic continuity linking individual plant cells. However, specialized cells may be isolated, either by the absence of plasmodesmata or by down regulation of the cytoplasmic flux through these channels, resulting in the formation of symplastic domains. Maintenance of these domains may be essential for the co-ordination of growth and development. While cells in the center of the meristem divide slowly and remain undifferentiated, cells on the meristem periphery divide more frequently and respond to signals determining organ fate. Such symplastic domains were visualized within shoot apices of Arabidopsis, by monitoring fluorescent symplastic tracers (HPTS: 8-hydroxypyrene 1,3,6 trisulfonic acid and CF: carboxy fluorescein). Tracers were loaded through cut leaves and distributed throughout the whole plant. Confocal laser scanning microscopy on living Arabidopsis plants indicates that HPTS moves via the vascular tissue from leaves to the apex where the tracer exits the phloem and moves symplastically into surrounding cells. The distribution of HPTS was monitored in vegetative apices, and just prior to, during, and after the switch to production of flowers. The apices of vegetative plants loaded with HPTS had detectable amounts of tracer in the tunica layer of the meristem and in very young primordia, whereas the corpus of the meristem excluded tracer uptake. Fluorescence signal intensity decreased prior to the onset of flowering. Moreover, at approximately the time the plants were committed to flowering, HPTS was undetectable in the inflorescence meristem or young primordia. Later in development, after several secondary inflorescences and mature siliques appeared, inflorescence apices again showed tracer loading at levels comparable to that of vegetative apices. Thus, analysis of fluorescent tracer movement via plasmodesmata reveals there is distinct temporal and spatial regulation of symplastic domains at the apex, dependent on the developmental stage of the plant.

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9

De Domenico, Francesca, Thibault F. Guiberti, Simone Hochgreb, William L. Roberts, and Gaetano Magnotti. "Tracer-free laser-induced grating spectroscopy using a pulse burst laser at 100 kHz." Optics Express 27, no. 22 (October 14, 2019): 31217. http://dx.doi.org/10.1364/oe.27.031217.

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10

Fendt, Peter, Ulrich Retzer, Hannah Ulrich, Stefan Will, and Lars Zigan. "Stability Analysis of the Fluorescent Tracer 1-Methylnaphthalene for IC Engine Applications by Supercontinuum Laser Absorption Spectroscopy." Sensors 20, no. 10 (May 19, 2020): 2871. http://dx.doi.org/10.3390/s20102871.

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1-methylnaphthalene (1-MN) is a widely used laser-induced fluorescence (LIF) tracer for planar imaging of mixture formation and temperature distributions in internal combustion (IC) engines. As the LIF measurement results can be biased by partial tracer oxidation, the conversion of 1-MN and the base fuel isooctane is analyzed in a calibration cell. First, measurements using supercontinuum laser absorption spectroscopy (SCLAS) are presented in order to quantify the conversion by detection of the produced H2O mole fraction. A single mode fiber (SMF) coupled setup is presented, with the fiber core acting as entrance slit of a Czerny-Turner spectrometer. Dependencies on residence time and global air-fuel ratio are presented at pressures up to 1.5 MPa and temperatures up to 900 K, at which distinct tracer and fuel consumption is observed. Signal loss due to intense beam steering was partially compensated using a self-stabilizing double-pass setup with a retroreflector.

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11

Gomez‐San Roman, R., R. Pérez Casero, C. Maréchal, J. P. Enard, and J. Perrière. "18O isotopic tracer studies of the laser ablation of Bi2Sr2Ca1Cu2O8." Journal of Applied Physics 80, no. 3 (August 1996): 1787–93. http://dx.doi.org/10.1063/1.362989.

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12

Moulin, C., and Xavier Vitart. "Pulsed microchip laser induced fluorescence for in situ tracer experiments." Fresenius' Journal of Analytical Chemistry 361, no. 2 (May 13, 1998): 81–85. http://dx.doi.org/10.1007/s002160050838.

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13

Gauthier, J. C., J. P. Geindre, P. Monier, C. Chenais-Popovics, N. Tragin, M. Klapisch, and A. Bar-Shalom. "Diagnostics of Gold Laser Plasmas." International Astronomical Union Colloquium 102 (1988): 357–60. http://dx.doi.org/10.1017/s0252921100108085.

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AbstractIn order to achieve a nickel-like X ray laser scheme we need a tool to determine the parameters which characterise the high-Z plasma. The aim of this work is to study gold laser plasmas and to compare experimental results to a collisional-radiative model which describes nickel-like ions. The electronic temperature and density are measured by the emission of an aluminium tracer. They are compared to the predictions of the nickel-like model for pure gold. The results show that the density and temperature can be estimated in a pure gold plasma.

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14

Del Sorbo, D., Y. Arikawa, D. Batani, F. Beg, J. Breil, H. Chen, J. L. Feugeas, et al. "Approach to the study of fast electron transport in cylindrically imploded targets." Laser and Particle Beams 33, no. 3 (July 3, 2015): 525–34. http://dx.doi.org/10.1017/s0263034615000592.

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AbstractThe transport of relativistic electron beam in compressed cylindrical targets was studied from a numerical and experimental point of view. In the experiment, cylindrical targets were imploded using the Gekko XII laser facility of the Institute of Laser Engineering. Then the fast electron beam was created by shooting the LFEX laser beam. The penetration of fast electrons was studied by observing Kα emission from tracer layers in the target.

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15

Sakaguchi, Isao, Ken Watanabe, Yutaka Adachi, Takeshi Ohgaki, Shunichi Hishita, Naoki Ohashi, and Hajime Haneda. "Oxygen Tracer Diffusion in A-Axis Oriented ZnO Thin Films Grown on (01-12) Sapphire by Pulsed Laser Deposition." Key Engineering Materials 566 (July 2013): 266–70. http://dx.doi.org/10.4028/www.scientific.net/kem.566.266.

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The a-axis oriented ZnO thin films deposited on sapphire substrates by pulsed laser deposition were studied to investigate the effects of pre-annealing on oxygen diffusion. The effect was as follows: the oxygen diffusion coefficient decreased, and the oxygen concentration in the tailing regions of the profiles reduced. Ion images of an oxygen tracer revealed the high-diffusivity paths for oxygen tracer diffusion. The temperature dependence of oxygen tracer diffusion coefficients (Db) in as-deposited and pre-annealed thin films were determined to be Db [cm2/ = 9.2x102 exp (- 405 [kJ/mo / RT) and Db [cm2/ = 1.8x103 exp (- 418 [kJ/mo / RT), respectively. On basis of these results, the crystal orientation on Db and the mechanism for oxygen diffusion were discussed.

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16

Castejón, O., and P. Sims. "Confocal Laser Scanning Microscopy of Hamster Cerebellum using FM4-64 as Intracellular Staining." Microscopy and Microanalysis 4, S2 (July 1998): 1126–27. http://dx.doi.org/10.1017/s1431927600025757.

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Confocal laser scanning microscopy is an excellent method to study nerve cell morphology and the three-dimensional distribution and interrelationship of dentrites and axons in the central nervous system. The cerebellum has been taking as a model of a gray center.The FM4-64, a member of the family of fluorescent dyes, has been applied to the cerebellar cortex to evaluate its properties as an intracellular stain and intracortical tracer. Slabs of hamster cerebellum,5 mm thick, were incubated in 10,30 and 100 μm solutions of FM4-64 in sodium phosphate buffer and observed in a slow scan confocal laser scanning microscope. Mossy and climbing fibers were traced in the cerebellar white and gray substances .They exhibited high fluorescence signal at the level of myelin sheath.Mossy fibers were identified in the granular layer by their typical rosette formation and dichotomous bifurcation pattern. Climbing fibers bundles were observed crossing the granular layer and giving collateral branches around Golgi cell bodies.

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17

Lee, Joseph H. W., Paul C. K. Chu, and Tony W. C. Yau. "Lateral Mixing of Continuous Line Source: An Introduction to Turbulent Diffusion." International Journal of Mechanical Engineering Education 24, no. 4 (October 1996): 265–78. http://dx.doi.org/10.1177/030641909602400405.

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The lateral turbulent mixing of a continuous line source of neutral tracer or contaminant in steady uniform open channel flow illustrates several useful concepts of advective diffusion. Flow visualization of the slender plume downstream of the source in a laboratory flume is presented. The self-similar tracer concentration field is obtained by both conductivity measurements and laser-induced fluorescence (L1F) techniques. The dimensionless turbulent diffusivity is determined, and the pedagogical features of the experiment are discussed.

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18

Chen Hongfang, 陈洪芳, 郑博文 Zheng Bowen, 石照耀 Shi Zhaoyao, 孙衍强 Sun Yanqiang, 隆昌宇 Long Changyu, and 杨再华 Yang Zaihua. "CMM Spatial Coordinate Correction Method Based on Laser Tracer Multistation Measurement." Chinese Journal of Lasers 44, no. 3 (2017): 0304003. http://dx.doi.org/10.3788/cjl201744.0304003.

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19

Mainsah, E., and K. J. Stout. "Signal processing unit for laser tracer providing submicron-accuracy diameter measurement." Electronics & Communications Engineering Journal 5, no. 2 (1993): 95. http://dx.doi.org/10.1049/ecej:19930018.

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20

King, Gregory F., Robert P. Lucht, and J. Craig Dutton. "Quantitative dual-tracer planar laser-induced fluorescence measurements of molecular mixing." Optics Letters 22, no. 9 (May 1, 1997): 633. http://dx.doi.org/10.1364/ol.22.000633.

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21

Zha, Jun, Linhui Li, Lin Han, and Yaolong Chen. "Four-station laser tracer-based geometric error measurement of rotary table." Measurement Science and Technology 31, no. 6 (March 17, 2020): 065008. http://dx.doi.org/10.1088/1361-6501/ab64ab.

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22

Cordier, Matthieu, Lama Itani, and Gilles Bruneaux. "Quantitative measurements of preferential evaporation effects of multicomponent gasoline fuel sprays at ECN Spray G conditions." International Journal of Engine Research 21, no. 1 (March 27, 2019): 185–98. http://dx.doi.org/10.1177/1468087419838391.

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A two-tracer laser-induced fluorescence technique is used to quantify the effects of preferential evaporation of multicomponent fuels on the fuel component distribution. The technique is based on the simultaneous detection of the fluorescence of two aromatic tracers with complementary evaporation characteristics matched to different components of a multicomponent fuel. Relative variations in the spatial distribution of tracer distribution as a consequence of preferential evaporation are determined from the ratio of laser-induced fluorescence signals measured within two distinct spectral bands. A thermodynamic model is then used to relate the ratio map with the fuel component map. The accuracy and precision of the method are characterized from determining the laser-induced fluorescence signal ratio within two identical spectral bands. Measurements are performed in a high-pressure high-temperature vessel equipped with an eight-hole injector. The Engine Combustion Network Spray G target conditions are chosen as reference conditions at injection. The only difference with these target conditions is the use of a multicomponent surrogate fuel. Parametric variations around these target conditions are also performed in order to investigate their effect on the preferential evaporation effect. The ambient temperature is varied between 525 and 625 K and the injection pressure is reduced from 200 to 100 bar. The impact of ethanol addition is also studied with two different fuel mixtures in addition to the reference surrogate fuel: E20 and E85 which feature 20% and 85% of pure ethanol within surrogate, respectively. A significant preferential evaporation effect is observed in this condition representative of engine applications and results in a spatial segregation between low- and high-volatility fuel components, respectively, at the tail and tip of the plumes. This effect is enhanced by the addition of ethanol and the decrease in ambient temperature and injection pressure.

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23

Yurechko, V. N. "Photochromic Flow Visualization for the Investigation of Artificial Heart Valves." International Journal of Artificial Organs 16, no. 3 (March 1993): 146–50. http://dx.doi.org/10.1177/039139889301600308.

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A new method for the investigation of hydrodynamics of artificial heart valves is presented. It is a method of flow visualisation. The photochromic flow visualization method is based on activation of color tracers in originally colorless photochromic solutions by pulse laser radiation during 10-6 − 10-9 seconds. The tracer appears as a straight colored line, which subsequently is deformed by the flow. The methods known so far for the flow visualization give an insight on the general flow but do not provide quantitative data. The method mainly used, the LDA, permits measurements only in one point. The new method combines the precision of the LDA with the clarity of flow visualization.

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Brumley, William C., and John W. Farley. "Determining eosin as a groundwater migration tracer by capillary electrophoresis/laser-induced fluorescence using a multiwavelength laser." ELECTROPHORESIS 24, no. 14 (July 2003): 2335–39. http://dx.doi.org/10.1002/elps.200305514.

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25

Uleh, Charles Adam, Jian Yong Zhang, Dong Lai Xu, and Ian French. "A Novel Approach to Multiphase Flow Metering Using PIV and Tracer Dilution." Advanced Materials Research 508 (April 2012): 71–74. http://dx.doi.org/10.4028/www.scientific.net/amr.508.71.

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This paper introduces a prototype multiphase flow metering system, named Uletech, for multiphase flow measurement. The Uletech Multiphase Flow Meter (UMFM) is based on the combination of particle recognition and the use of Laser Imaging Technology in the form of Particle Imaging Velocimetry (PIV). PIV uses tracer particles which follow the gas or liquid phase. The high resolution digital laser cameras identify/recognize all the different sizes of particle (gas, oil and water) in a multiphase flow. The cameras have sufficiently high resolutions (pixel size) to "see" the tracer particles. The prevailing conditions of high pressure and temperature of the flow regimes makes actual measurement a great challenge. The velocity differences between phases (hold up and slip) means unless the velocities of individual phases and concentrations are known, the true flow rate is practically impossible to obtain. The system comprised of two cameras, laser source, optical arrangement, computer data acquisition system, synchronizer and MATLAB based software. An algorithm that correlates the cameras view to the volume within the pipe has been developed through this research. The computer acquires image signals from the upstream and/or downstream cameras, and carries out the calculation of cross correlation between the two image frames so that the velocity of each pixel can be found. A Gas Liquid Chromatograph (GLC) provides the composition (concentration) of the gas and the liquid hydrocarbon (HC). The product of phase velocity and phase concentration provides the flow rate of the individual phase. This work provides theoretical analysis and experimental validations, and discusses the advantages of the system and its further development.

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26

de Sercey, G., M. Heikal, M. Gold, S. Begg, R. Wood, G. Awcock, and O. Laguitton. "On the use of laser-induced fluorescence for the measurement of in-cylinder air—fuel ratios." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 216, no. 10 (October 1, 2002): 1017–29. http://dx.doi.org/10.1243/095440602760400986.

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This paper presents the development of a new strategy for the calibration of air-fuel ratio measurements in engines by laser-induced fluorescence (LIF). After a brief introduction to the LIF technique, the paper highlights the structured approach undertaken to ensure that accurate quantitative measurements were produced. In particular, the new approach to coping with the fluorescence dependency on pressure and temperature, the issues related to the choice of a fluorescence tracer, the careful determination of the optimum tracer concentration and the complete calibration methodology are described, together with the resolution of some of the obstacles encountered. The paper concludes with some examples of calibrated measurements accompanied by a comparison of the results with combustion and emission performances. These results show a very good correlation.

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27

Zha, Jun, Tao Wang, Linhui Li, and Yaolong Chen. "Volumetric error compensation of machine tool using laser tracer and machining verification." International Journal of Advanced Manufacturing Technology 108, no. 7-8 (June 2020): 2467–81. http://dx.doi.org/10.1007/s00170-020-05556-8.

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28

Chang, Guang, Xin Yu, Jiangbo Peng, Yang Yu, Zhen Cao, Long Gao, Minghong Han, and Guohua Wu. "Absorption, quenching, and enhancement by tracer in acetone/toluene laser-induced fluorescence." Chinese Physics B 29, no. 12 (December 2020): 124212. http://dx.doi.org/10.1088/1674-1056/abb3e1.

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Douglawi, Alber, Anthony McMaster, Megan E. Paciaroni, James B. Michael, Benjamin R. Halls, James R. Gord, and Terrence R. Meyer. "Tracer-free liquid–vapor imaging using lifetime-filtered planar laser-induced fluorescence." Optics Letters 44, no. 8 (April 15, 2019): 2101. http://dx.doi.org/10.1364/ol.44.002101.

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Koban, W., J. Schorr, and C. Schulz. "Oxygen-distribution imaging with a novel two-tracer laser-induced fluorescence technique." Applied Physics B: Lasers and Optics 74, no. 1 (January 1, 2002): 111–14. http://dx.doi.org/10.1007/s003400100769.

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Fan, Rui, and Di Zhang. "Research on the Compensation Method of Installation Errors in Guideway Straightness Measurement with PSD." Advanced Materials Research 630 (December 2012): 389–95. http://dx.doi.org/10.4028/www.scientific.net/amr.630.389.

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Influence and Compensation Theory of Installation Errors in Guideway Straightness Measurement with PSD Is Analyzed. it Shows that Pincushion Distortion Affects PSD’s Accuracy, while Angle θ between Laser and Guideway, Error Angle Caused by Straightness Error and Angle β Generated when PSD Rotates about the Guideway Have Significant Influence on System Measurement Accuracy. PSD’s Pincushion Distortion Could Be Corrected and Installation State Can Be Determined by Measuring on Site and Calibrating with Laser Tracer. after Error Compensation, System Measurement Accuracy Is Greatly Improved.

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Robinson, J. M., and B. E. Batten. "Detection of diaminobenzidine reactions using scanning laser confocal reflectance microscopy." Journal of Histochemistry & Cytochemistry 37, no. 12 (December 1989): 1761–65. http://dx.doi.org/10.1177/37.12.2555410.

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We used scanning laser confocal microscopy to visualize sites of peroxidatic activity as detected by the diaminobenzidine (DAB) reaction. Imaging was achieved by employing the reflectance mode of this instrument. Intense reflectance was detected after DAB localization of endogenous granule-associated myeloperoxidase in neutrophils and of the exogenous tracer horseradish peroxidase in mouse oocytes. Detection of DAB reaction products with confocal reflectance microscopy will probably be an important addition to the utility of this cytochemical technique.

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33

Numata, Hideo, and Takehiko Ono. "Redox features of β-VOPO4 catalyst using 18O tracer and laser Raman spectroscopy." Journal of Molecular Catalysis A: Chemical 130, no. 3 (April 1998): 261–69. http://dx.doi.org/10.1016/s1381-1169(97)00217-3.

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Ferguson, Patrick L., Andrew H. Grange, William C. Brumley, Joseph R. Donnelly, and John W. Farley. "Capillary electrophoresis/laser-induced fluorescence detection of fluorescein as a groundwater migration tracer." Electrophoresis 19, no. 12 (September 1998): 2252–56. http://dx.doi.org/10.1002/elps.1150191234.

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35

NEIJ, H., A. SAITZKOFF, R. REINMANN, A. FRANKE, and M. ALDÉN. "Application of Two-Dimensional Laser-Induced Fuel Tracer Fluorescence for Ion Current Evaluation." Combustion Science and Technology 140, no. 1-6 (December 1998): 295–314. http://dx.doi.org/10.1080/00102209808915775.

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36

Freedman, Lorin J., and Hong Yi. "Confocal imaging of the retrograde tracer fluoro-gold using a non-ultraviolet laser." Brain Research Bulletin 31, no. 6 (January 1993): 749–51. http://dx.doi.org/10.1016/0361-9230(93)90152-2.

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37

Koch, J. A., C. A. Back, C. Brown, K. Estabrook, B. A. Hammel, S. P. Hatchett, M. H. Key, et al. "Time-resolved X-ray spectroscopy of deeply buried tracer layers as a density and temperature diagnostic for the fast ignitor." Laser and Particle Beams 16, no. 1 (March 1998): 225–32. http://dx.doi.org/10.1017/s0263034600011873.

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The fast ignitor concept for inertial confinement fusion relies on the generation of hot electrons, produced by a short-pulse ultrahigh intensity laser, which propagate through high-density plasma to deposit their energy in the compressed fuel core and heat it to ignition. In preliminary experiments designed to investigate deep heating of high-density matter, we used a 20 joule, 0.5–30 ps laser to heat solid targets, and used emission spectroscopy to measure plasma temperatures and densities achieved at large depths (2–20 microns) away from the initial target surface. The targets consisted of an Al tracer layer buried within a massive CH slab; H-like and He-like line emission was then used to diagnose plasma conditions. We observe spectra from tracer layers buried up to 20 microns deep, measure emission durations of up to 200 ps, measure plasma temperatures up to Te=650 eV, and measure electron densities above 1023 cm−3. Analysis is in progress, but the data are in reasonable agreement with heating simulations when space-charge induced inhibition is included in hot-electron transport, and this supports the conclusion that the deep heating is initiated by hot electrons.

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Cong, Hongdong, Jun Zha, Linhui Li, Yipeng Li, and Yaolong Chen. "Accuracy evaluation of geometric error calibration using a laser tracer via a formulaic approach." Measurement Science and Technology 32, no. 2 (November 26, 2020): 025003. http://dx.doi.org/10.1088/1361-6501/abb9e8.

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39

Lozano, A., B. Yip, and R. K. Hanson. "Acetone: a tracer for concentration measurements in gaseous flows by planar laser-induced fluorescence." Experiments in Fluids 13, no. 6 (October 1992): 369–76. http://dx.doi.org/10.1007/bf00223244.

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40

Beissler, H., G. A. Petrucci, K. B�chmann, U. Panne, P. Cavalli, and N. Omenetto. "Determination of ultra-trace levels of gold in size-segregated atmospheric particulate samples by laser induced fluorescence: towards an aerosol tracer." Analytical and Bioanalytical Chemistry 355, no. 3-4 (June 1, 1996): 345–47. http://dx.doi.org/10.1007/s0021663550345.

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41

Shah, A., J. E. Bailes, V. Sahgal, and L. J. Cerullo. "Cytochemistry and morphometry of rat sciatic nerve following laser and suture treatments." Proceedings, annual meeting, Electron Microscopy Society of America 44 (August 1986): 128–29. http://dx.doi.org/10.1017/s0424820100142281.

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The success of nerve repair treatment can be measured by examining the factors (Wallerian degeneration) that prevent functional recovery, and determining the extent of regeneration of proximal axon sprouts in the endoneurial environment of the distal fascicles. In the present study, the neurosurgical alignment of fascicles was attempted by laser as well as suture microsurgery of transected rat sciatic nerve and the relative efficacy of the two procedures was evaluated after 6 and 12 weeks by Neurophysiological Study, Morphological Study with light microscopy, ultrastructure, and the permeability of blood-nerve barrier using horseradish peroxidase (HRP) tracer technique, and Morphometry of the nerve fibers.

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42

Peng, Jiang Bo, Ze Fang Lv, Xin Yu, Song He Meng, Hao Dong, Fan Deng, Lin Chen, et al. "Visualization of Flow Field: Application of PLIF Technique." Journal of Spectroscopy 2018 (2018): 1–6. http://dx.doi.org/10.1155/2018/8759898.

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The objective of this paper is to apply planar laser-induced fluorescence (PLIF) technology to flow field visualization. This experiment was carried out in a one-meter wind tunnel to study the wake flow field around a circular cylinder. This experiment studied the method of injecting tracer into the flow field; the frequency of the vortex in the wake field and the vortex speed are quantitatively analyzed. This paper gives the correspondence between the speed of the flow field and the frequency of the laser, which could be used as a rough reference standard for future wind tunnel visualization experiments. The result shows that PLIF diagnostic technology has great potential in visualization of flow field.

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Kousik, Shravan, Diane Sipp, Karina Abitaev, Yawen Li, Thomas Sottmann, Kaloian Koynov, and Petia Atanasova. "From Macro to Mesoporous ZnO Inverse Opals: Synthesis, Characterization and Tracer Diffusion Properties." Nanomaterials 11, no. 1 (January 14, 2021): 196. http://dx.doi.org/10.3390/nano11010196.

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Oxide inverse opals (IOs) with their high surface area and open porosity are promising candidates for catalyst support applications. Supports with confined mesoporous domains are of added value to heterogeneous catalysis. However, the fabrication of IOs with mesoporous or sub-macroporous voids (<100 nm) continues to be a challenge, and the diffusion of tracers in quasi-mesoporous IOs is yet to be adequately studied. In order to address these two problems, we synthesized ZnO IOs films with tunable pore sizes using chemical bath deposition and template-based approach. By decreasing the size of polystyrene (PS) template particles towards the mesoporous range, ZnO IOs with 50 nm-sized pores and open porosity were synthesized. The effect of the template-removal method on the pore geometry (spherical vs. gyroidal) was studied. The infiltration depth in the template was determined, and the factors influencing infiltration were assessed. The crystallinity and photonic stop-band of the IOs were studied using X-Ray diffraction and UV-Vis, respectively. The infiltration of tracer molecules (Alexa Fluor 488) in multilayered quasi-mesoporous ZnO IOs was confirmed via confocal laser scanning microscopy, while fluorescence correlation spectroscopy analysis revealed two distinct diffusion times in IOs assigned to diffusion through the pores (fast) and adsorption on the pore walls (slow).

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Xiao, F., X. Y. Li, and K. M. Lam. "Investigation of the hydrodynamic behaviour of particles and aggregates by particle image velocimetry (PIV)." Water Supply 7, no. 2 (July 1, 2007): 213–20. http://dx.doi.org/10.2166/ws.2007.056.

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An advanced fluid visualisation technique, particle image velocimetry, was employed to investigate the hydrodynamic properties of particles and aggregates. The experiments were conducted in a settling column filled with a suspension of fluorescent polymeric beads as flow tracers. A thin vertical section of the settling column was illuminated by a laser sheet, while the motions of particles were recorded by a high speed CCD camera. Large solid spheres, flocs of latex microspheres and aggregates of marine diatoms were characterised for their hydrodynamic properties. The trajectories of the tracer particles were tracked when a large particle or aggregate settled through the suspension of the tracers, which gave the streamlines surrounding the falling object. The streamlines demonstrate directly the curvilinear feature of the interaction between approaching particles. However, the available curvilinear model underestimates the collision frequency function of particles by one order of magnitude or two. The collision potentials of the flocs and aggregates are more than an order of magnitude greater than the similar-sized solid spheres. Algal aggregates appear to be highly porous and fractal with a fluid collection efficiency of 10–40%, which would significantly enhance the flocculation between particles and the mass transfer into the aggregates.

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Ono, Takehiko, Nobuaki Ogata, and Robert L. Kuczkowski. "Tracer Studies of Olefin Oxidation over an α-Bi2Mo3O12Catalyst Using Laser Raman and Microwave Spectroscopy." Journal of Catalysis 175, no. 2 (April 1998): 185–93. http://dx.doi.org/10.1006/jcat.1998.2006.

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Zheng, Jihui, Dongjing Miao, Jianshuang Li, Shuai Zhang, and Baixing Fan. "A new large-scale posture measurement system based on a six-laser tracer multilateral method." Measurement Science and Technology 31, no. 5 (February 6, 2020): 055010. http://dx.doi.org/10.1088/1361-6501/ab62c6.

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GRIBBON, Phillip, Boon Chin HENG, and Timothy E. HARDINGHAM. "The analysis of intermolecular interactions in concentrated hyaluronan solutions suggest no evidence for chain–chain association." Biochemical Journal 350, no. 1 (August 9, 2000): 329–35. http://dx.doi.org/10.1042/bj3500329.

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Confocal fluorescence recovery after photobleaching (confocal-FRAP) was used to examine the influence of electrolytes (NaCl, KCl, MgCl2, MnCl2 and CaCl2) on the network and hydrodynamic properties of fluoresceinamine-labelled hyaluronan (FA-HA) at concentrations up to 10mg/ml. Self and tracer lateral diffusion coefficients showed that in Ca2+ and Mn2+, FA-HA (830kDa) was more compact than in Mg2+, Na+ or K+. These results were correlated with changes in the hydrodynamic radius of HA, determined by multi-angle laser-light-scattering analysis in dilute solution, which was smaller in CaCl2 (36nm) than in NaCl (43nm). The permeability of more concentrated solutions of HA (< 10mg/ml) to FITC-dextran tracers (2000kDa) was higher in CaCl2. The properties of HA in urea (up to 6M) were investigated to test for hydrophobic interactions and also in ethanol/water (up to 62%, v/v). In both, there was reduced hydrodynamic size and increased permeability to FITC-dextran, suggesting increased chain flexibility, but it did not show the changes predicted if chain–chain association was disrupted by urea, or enhanced by ethanol. Oligosaccharides of HA (HA20–26) also had no effect on the self diffusion of high-molecular-mass FA-HA (830kDa) solutions, or on dextran tracer diffusion, showing that there were no chain–chain interactions open to competition by short-chain segments. The results suggest that the effects of electrolytes and solvent are determined primarily by their effect on HA chain flexibility, with no evidence for association between chain segments contributing significantly to the major properties.

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Barthel, M., P. Sturm, L. Gentsch, and A. Knohl. "Technical Note: A combined soil/canopy chamber system for tracing δ13C in soil respiration after a 13CO2 canopy pulse labelling." Biogeosciences Discussions 7, no. 2 (March 3, 2010): 1603–31. http://dx.doi.org/10.5194/bgd-7-1603-2010.

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Abstract. In this study we present a combined soil/canopy chamber system that allows the investigation of carbon flow through the atmosphere-plant-soil system via a 13CO2 canopy labelling approach – especially when using short vegetation such as tree saplings. The developed chamber system clearly separates soil and canopy compartment in order to (a) prevent physical diffusion of 13C tracer into the soil chamber during a 13CO2 canopy pulse labelling (b) study stable isotope processes in soil and canopy individually and independently. In combination with novel laser spectrometry, measuring CO2 (Aerodyne Research Inc.) and H2O (Los Gatos Research Inc.) isotopologue mixing ratios at a rate of 1 Hz, we were able to trace the label transport from leaves to roots in small beech saplings (Fagus sylvatica L.) without interference due to contamination of the soil matrix and/or canopy re-labelling via tracer returning from soil respiration. A very tight coupling between above- (photosynthesis) and belowground (soil respiration) processes was found, where newly assimilated carbon fixed from the 13CO2 atmosphere re-appeared in soil respiration 2 h after it has been photosynthetically fixed. We were able to demonstrate that leaf metabolism acts on substrate for soil respiration on a diurnal timescale, with input of fresh photosynthates during daytime and starch re-mobilisation during nighttime. Long-term fluctuations in the δ13C of soil respiration, as observed under reduced water availability, could not be described by any biological or instrumental mechanism, as they did occur in an atypical ca. 15 hourly rhythm – potential mechanisms driving these fluctuations are hypothesized.

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Krainara, Siriwan, Shuya Chatani, Heishun Zen, Toshiteru Kii, and Hideaki Ohgaki. "Manipulation of Laser Distribution to Mitigate the Space-Charge Effect for Improving the Performance of a THz Coherent Undulator Radiation Source." Particles 1, no. 1 (November 7, 2018): 238–52. http://dx.doi.org/10.3390/particles1010018.

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A THz coherent undulator radiation (THz-CUR) source has been developed at the Institute of Advanced Energy, Kyoto University. A photocathode Radio-Frequency (RF) gun and a bunch compressor chicane are used for generating short-bunch electron beams. When the electron beam energy is low, the space-charge effect strongly degrades the beam quality, such as the bunch length and the energy spread at the high bunch charge condition at around 160 pC, and results in the reduction of the highest frequency and the maximum radiated power of the THz-CUR. To mitigate the space charge effect, we have investigated the dependence of the electron beam quality on the laser distribution in transverse and longitudinal directions by using a numerical simulation code, General Particle Tracer GPT. The manipulation of the laser distribution has potential for improving the performance of the THz-CUR source. The electron bunch was effectively compressed with the chicane magnet when the laser transverse distribution was the truncated Gaussian profile, illuminating a cathode. Moreover, the compressed electron bunch was shortened by enlarging the laser pulse width. Consequently, an enhancement of the radiated power of the THz-CUR has been indicated.

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Thomson, S. L., and D. Maynes. "Spatially Resolved Temperature Measurements in a Liquid Using Laser Induced Phosphorescence." Journal of Fluids Engineering 123, no. 2 (February 8, 2001): 293–302. http://dx.doi.org/10.1115/1.1365960.

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This paper describes recent advances in the development of a temperature measurement methodology based on phosphorescence of a tracer molecule in a liquid. The methodology represents an extension of molecular tagging velocimetry (MTV). MTV is a laser-based technique of obtaining spatially resolved fluid velocity profiles. The methodology has the potential of providing spatially resolved simultaneous measurements of velocity and temperature data over a planar domain. Presently, a method of obtaining temperatures over a range of 30°C with a typical uncertainty of ±1.0–1.5°C has been developed. Recent progress has resulted in a method of generating robust calibration curves for use in subsequent temperature measurements. A discussion of the experimental methodology, calibration curve development, and error analysis is presented. Finally, simultaneous temperature and velocity profile measurements using the method are demonstrated under dynamic conditions.

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Journal articles on the topic 'Laser tracer'

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