Full-field velocity imaging technique using high-energy pulsed laser velocimetry

1990 ◽  
Author(s):  
Yassin A. Hassan ◽  
Thomas Blanchat ◽  
Robert D. Hild
Keyword(s):  
Imaging Technique ◽  
Pulsed Laser ◽  
High Energy ◽  
Full Field ◽  
Laser Velocimetry ◽  
Velocity Imaging ◽  
Field Velocity

scholarly journals Full-field velocity imaging of red blood cells in capillaries with spatiotemporal demodulation autocorrelation

2016 ◽  
Vol 21 (03) ◽  
pp. 1
Author(s):  
Mingyi Wang ◽  
Yaguang Zeng ◽  
Nannan Dong ◽  
Riwei Liao ◽  
Guojian Yang
Keyword(s):  
Red Blood Cells ◽  
Blood Cells ◽  
Full Field ◽  
Velocity Imaging ◽  
Field Velocity

scholarly journals Effects of Accumulated Energy on Nanoparticle Formation in Pulsed-Laser Dewetting of AgCu Thin Films

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
H. K. Lin ◽  
C. W. Huang ◽  
Y. H. Lin ◽  
W. S. Chuang ◽  
J. C. Huang
Keyword(s):  
Pulsed Laser ◽  
Blue Shift ◽  
High Energy ◽  
Low Energy ◽  
Nanoparticle Formation ◽  
Energy Accumulation ◽  
Glass Substrates ◽  
Peak Absorption ◽  
Two Peaks ◽  
Sputtering System

AbstractAg50Cu50 films were deposited on glass substrates by a sputtering system. Effects of accumulated energy on nanoparticle formation in pulse-laser dewetting of AgCu films were investigated. The results showed that the properties of the dewetted films were found to be dependent on the magnitude of the energy accumulated in the film. For a low energy accumulation, the two distinct nanoparticles had rice-shaped/Ag60Cu40 and hemispherical/Ag80Cu20. Moreover, the absorption spectra contained two peaks at 700 nm and 500 nm, respectively. By contrast, for a high energy accumulation, the nanoparticles had a consistent composition of Ag60Cu40, a mean diameter of 100 nm and a peak absorption wavelength of 550 nm. Overall, the results suggest that a higher Ag content of the induced nanoparticles causes a blue shift of the absorption spectrum, while a smaller particle size induces a red shift.

Mullite Diffusion Barriers for SiC-C/C Composites Produced by Pulsed Laser Deposition

1998 ◽  
Vol 555 ◽  
Author(s):  
H. Fritze ◽  
A. Schnittker ◽  
T. Witke ◽  
C. Rüscher ◽  
S. Weber ◽  
...  
Keyword(s):  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Target Material ◽  
High Energy ◽  
Single Step ◽  
Laser Deposition ◽  
Reduced Pressure ◽  
Oxidation Rates ◽  
Energy Impact ◽  
Diffusion Parameters

AbstractPulsed Laser Deposition (PLD) allows the ablation of nonconductive and high melting point target materials and the preparation of films with complex composition. High energy impact leads to melting and evaporation of the target material in a single step. In case of mullite ablation, the flux of the metal components is stoichiometric. Under reduced pressure the oxygen content in the layers decreases. However, after a short oxidation treatment, the formation of mullite in the coating is completed, as confirmed by IR spectroscopy and XRD investigations. For a commercial Si-SiC precoated C/C material, the effectiveness of additional PLD mullite layers as outer oxidation protection is tested in the temperature range 773 K < T < 1873 K. Mullite coatings with a thickness of 2.5 pm improve the oxidation behaviour significantly. Because of SiO2 formation at the mullite-SiC interface, all samples exhibited a mass increase upon oxidation. For oxidation durations of three days, only amorphous SiO2 is formed at the mullite-SiC interface. The inward diffusion of oxygen across the outer mullite-containing layer controls the kinetics of the reaction, as was deduced from 18O diffusivity measurements in PLD mullite layers. At temperatures close to the eutectic temperature (1860 K), mullite can seal defects. The calculated oxidation rates resulting from the diffusion parameters in SiO2 and mullite are close to the thermogravimetric data.

Heterodyne speckle interferometer for full-field velocity profile measurements of a vibrating membrane by electronic scanning

2007 ◽  
Vol 45 (6) ◽  
pp. 677-683 ◽  
Author(s):  
Mauro V. Aguanno ◽  
Fereydoun Lakestani ◽  
Maurice P. Whelan ◽  
Michael J. Connelly
Keyword(s):  
Velocity Profile ◽  
Full Field ◽  
Speckle Interferometer ◽  
Field Velocity ◽  
Vibrating Membrane

scholarly journals In-Situ Diagnostics at High Pressures: Ellipsometric and Rheed Studies of the Growth of Yba2Cu3O7

1997 ◽  
Vol 502 ◽  
Author(s):  
Dave H. A. Blank ◽  
Horst Rogalla
Keyword(s):  
Thin Films ◽  
High Pressures ◽  
High Vacuum ◽  
Pulsed Laser ◽  
Complex Oxide ◽  
High Energy ◽  
Diagnostic Tools ◽  
Heteroepitaxial Growth ◽  
Deposition Parameters

ABSTRACTPulsed Laser and Sputter Deposition are used for the fabrication of complex oxide thin films at relatively high oxygen pressures (up to 0.5 mBar). This high pressure hampers the application of a number of in-situ diagnostic tools. One of the exceptions is ellipsometry. Using this technique we studied in-situ the growth of off-axis sputtered Yba2Cu3O6+x thin films on (001) SrTiO3 as a function of the deposition parameters. Furthermore, the oxidation process from O(6) to O(7) has been studied by performing spectroscopic ellipsometry during isobaric cooling procedures.Another suitable in-situ monitoring technique for the growth of thin films is Reflection High Energy Electron Diffraction (RHEED). In general this is a (high) vacuum technique. Here, we present an RHEED-system in which we can observe clear diffraction patterns up to a deposition pressure of 0.5 mBar. The system has been used for in-situ monitoring of the heteroepitaxial growth of YBa2Cu3 06+x on SrTiO3 by pulsed laser deposition.

scholarly journals Overheating In Silicon During Pulsed-Laser Irradiation?

1985 ◽  
Vol 51 ◽  
Author(s):  
B. C. Larson ◽  
J. Z. Tischler ◽  
D. M. Mills
Keyword(s):  
Laser Irradiation ◽  
Thermal Strain ◽  
Pulsed Laser ◽  
Interface Velocity ◽  
High Energy ◽  
Time Resolved ◽  
Synchrotron Source ◽  
Zero Velocity ◽  
The Difference ◽  
Pulsed Laser Irradiation

ABSTRACTNanosecond resolution time-resolved x-ray diffraction measurements of thermal strain have been used to measure the interface temperatures in silicon during pulsed-laser irradiation. The pulsed-time-structure of the Cornell High Energy Synchrotron Source (CHESS) was used to measure the temperature of the liquid-solid interface of <111> silicon during melting with an interface velocity of 11 m/s, at a time of near zero velocity, and at a regrowth velocity of 6 m/s. The results of these measurements indicate 110 K difference between the temperature of the interface during melting and regrowth, and the measurement at zero velocity shows that most of the difference is associated with undercooling during the regrowth phase.

Fabrication of Ni–Al thin films by the pulsed laser deposition technique

1992 ◽  
Vol 7 (10) ◽  
pp. 2639-2642 ◽  
Author(s):  
R.K. Singh ◽  
Deepika Bhattacharya ◽  
S. Sharan ◽  
P. Tiwari ◽  
J. Narayan
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Rutherford Backscattering Spectrometry ◽  
Pulsed Laser ◽  
High Energy ◽  
Laser Deposition ◽  
Nanosecond Laser ◽  
X Ray ◽  
Target Composition

We have fabricated Ni3Al and NiAl thin films on different substrates by the pulsed laser deposition (PLD) technique. A high energy nanosecond laser beam was directed onto Ni–Al (NiAl, Ni3Al) targets, and the evaporated material was deposited onto substrates placed parallel to the target. The substrate temperature was varied between 300 and 400 °C, and the substrate-target distance was maintained at approximately 5 cm. The films were analyzed using scanning electron microscopy, transmission electron microscopy, x-ray diffraction, and Rutherford backscattering spectrometry. At energy densities slightly above the evaporation threshold, a slight enrichment of Al was observed, while at higher energy densities the film stoichiometry was close (<5%) to the target composition. Barring a few particles, the surface of the films exhibited a smooth morphology. X-ray and TEM results corroborated the formation of Ni3Al and NiAl films from similar target compositions. These films were characterized by small randomly oriented grains with grain size varying between 200 and 400 Å.

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