Influence of Guard Intervals Length on Detection of Long Pulse Signals

2018 ◽  
Author(s):  
Ilnur R. Ishkaev ◽  
Andrei A. Belov ◽  
Sergey V. Zavjalov
Keyword(s):  
Long Pulse

Thermal scribing processes with long-pulse and Q-switch fiberlasers

2014 ◽  
Author(s):  
Christoph Ruettimann ◽  
Ulrich Duerr ◽  
Raymond von Niederhaeusern ◽  
Matthias Julius
Keyword(s):  
Long Pulse

Long Pulse Homopolar Generator

1988 ◽  
Author(s):  
Edward A. Knoth ◽  
David P. Bauer
Keyword(s):  
Long Pulse

Optical properties of benzene and derivatives by the single beam thermal lens technique

2017 ◽  
Vol 26 (02) ◽  
pp. 1750025 ◽  
Author(s):  
M. K. Biswas ◽  
P. K. Das ◽  
E. Hoque ◽  
S. M. Sharafuddin ◽  
S. K. Das ◽  
...  
Keyword(s):  
Thermal Lens ◽  
Continuous Wave ◽  
Refractive Index Change ◽  
Optical Nonlinearity ◽  
Index Change ◽  
Single Beam ◽  
Cw Laser ◽  
Ion Laser ◽  
Benzene Toluene ◽  
Long Pulse

The present work studies the optical nonlinearity exhibited by the material (for Continuous Wave (CW) laser or long pulse) due to the change in thermal properties of the material on illumination. Thermal lens (TL) technique has been used to measure the refractive index change due to the formation of TL along with other thermo-optic properties of the material in solution. A CW Ar-ion laser has been used as light source and the laser beam was chopped at 25[Formula: see text]Hz frequency to obtain 12[Formula: see text]ms pulse to observe the formation of the TL within the sample. The [Formula: see text] value have been calculated by the TL technique for Benzene, Toluene and Dimethylaniline (DMA) in toluene and Benzene. The [Formula: see text] value is found to be in the order of 10[Formula: see text] to 10[Formula: see text][Formula: see text]cm2[Formula: see text]W[Formula: see text].

scholarly journals Experimental Study of Plasma Plume Analysis of Long Pulse Laser Irradiates CFRP and GFRP Composite Materials

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 545
Author(s):  
Yao Ma ◽  
Chao Xin ◽  
Wei Zhang ◽  
Guangyong Jin
Keyword(s):  
Composite Materials ◽  
Laser Processing ◽  
Plasma Plume ◽  
Material Surface ◽  
Laser Fabrication ◽  
Breakdown Time ◽  
Reinforced Polymer ◽  
Gfrp Composite ◽  
Damage Process ◽  
Long Pulse

The application of laser fabrication of fiber-reinforced polymer (FRP) has an irreplaceable advantage. However, the effect of the plasma generated in laser fabrication on the damage process is rarely mentioned. In order to further study the law and mechanism of laser processing, the laser process was measured. CFRP and GFRP materials were damaged by a 1064 nm millisecond pulsed laser. Moreover, the propagation velocity and breakdown time of plasma plume were compared. The results show that GFRP is more vulnerable to breakdown than CFRP under the same conditions. In addition, the variation of plasma plume and material surface temperature with the number of pulses was also studied. The results show that the variation trend is correlated, that is, the singularities occur at the second pulse. Based on the analysis of experimental phenomena, this paper provides guidance for plasma phenomena in laser processing of composite materials.

scholarly journals Effects of Non-thermal Ultrasound on a Fibroblast Monolayer Culture: Influence of Pulse Number and Pulse Repetition Frequency

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5040
Author(s):  
Silvia Ronda Peñacoba ◽  
Mar Fernández Gutiérrez ◽  
Julio San Román del Barrio ◽  
Francisco Montero de Espinosa
Keyword(s):  
Short Pulse ◽  
Pulse Repetition Frequency ◽  
Pulse Number ◽  
Repetition Frequency ◽  
Pulse Repetition ◽  
Treatment Protocols ◽  
Culture Plate ◽  
New Treatment ◽  
Long Pulse

Despite the use of therapeutic ultrasound in the treatment of soft tissue pathologies, there remains some controversy regarding its efficacy. In order to develop new treatment protocols, it is a common practice to carry out in vitro studies in cell cultures before conducting animal tests. The lack of reproducibility of the experimental results observed in the literature concerning in vitro experiments motivated us to establish a methodology for characterizing the acoustic field in culture plate wells. In this work, such acoustic fields are fully characterized in a real experimental configuration, with the transducer being placed in contact with the surface of a standard 12-well culture plate. To study the non-thermal effects of ultrasound on fibroblasts, two different treatment protocols are proposed: long pulse (200 cycles) signals, which give rise to a standing wave in the well with the presence of cavitation (ISPTP max = 19.25 W/cm2), and a short pulse (five cycles) of high acoustic pressure, which produces a number of echoes in the cavity (ISPTP = 33.1 W/cm2, with Pmax = 1.01 MPa). The influence of the acoustic intensity, the number of pulses, and the pulse repetition frequency was studied. We further analyzed the correlation of these acoustic parameters with cell viability, population, occupied surface, and cell morphology. Lytic effects when cavitation was present, as well as mechanotransduction reactions, were observed.

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