In this work, a pulsed Nd:YAG laser(out put energy=5J and pulse
duration=300μsec) was used to perform drilling in samples of lead, stainless steel
304, brass, copper and aluminum. Laser irradiation was carried out in both air and
in a suitable chamber of controlled pressure inside. The effect of pressure inside the
chamber on the drilling process was investigated. Then, the chamber was filled with
argon gas to investigate its effect on drilling process where an enhancement in
drilling depth was observed compared to that in case of irradiation in air and
chamber of air pressure. As well, the effect of focus position on the process was
studied with the pressure varying inside the chamber in order to construct a
mathematical model describing such process
Colloidal dispersions of mono Au, Ag , Cu and bimetallic Ag/Au and Cu/Au
core/shell nanoparticles are synthesized by pulsed laser ablation of metals targets
immersed in 5 ml distilled water (DW). Surface Plasmon resonance (SPR) and
particle sizes are characterized by UV-VIS and HRTEM, the X-ray diffraction
shows the structure of core/shell. The Surface Plasmon resonance of the produced
nanoparticles solutions for silver nanoparticles about 402 nm and copper
nanoparticles about 636 nm. While for the core-shell observed two peaks of SPR,
Ag/Au core/shell at (406-516) nm, and Cu/Au core/shell observed one peak at
565nm, because the region of gold and copper close together. The shape and
particle size have been con
In this work, a (CdO)0.94:(In2O3)0.06 film was developed on a glass substrate using Q- switching pulse laser beam (Nd:YAG; wavelength 1064 nm). The quantitative elemental analysis of the (CdO)0.94:(In2O3)0.06 thin film was achieved using energy dispersive X- ray diffraction (EDX). The topological and morphological properties of the deposited thin film were investigated using atomic force microscope (AFM) and field emission scan electron microscopy (FESEM). The I-V characteristic and Hall effect of (CdO)0.94 :(In2O3)0.06 thin films were used to study the electrical properties. The gas sensor prope
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Nowadays laser in medicine is a rapidly growing field in both researches and applications and many studies have been done in bacteriology against different types of lasers. The effect of the laser depends on many factors, one of the laser factors was the wavelength. The red wavelength band has been considered as a stimulated wavelength for prokaryotic and eukaryotic cells. In this study, three clinical species of Gram-negative bacteria (E. coli, Proteus mirabilis, and Pseudomonas aeruginosa) were exposed to 650 nm band of red region wavelength by a diode laser. The effect of that wavelength appeared on the growth curves for each species along 3 days after laser treatment. The energy density (E.D.) 2.8 J/cm2 gave a positive effect on grow
... Show MoreA theoretical model is developed to determine time evolution of temperature at the surface of an opaque target placed in air for cases characterized by the formation of laser supported absorption waves (LSAW) plasmas. The model takes into account the power temporal variation throughout an incident laser pulse, (i.e. pulse shape, or simply: pulse profile).
Three proposed profiles are employed and results are compared with the square pulse approximation of a constant power.