We have investigated the impact of laser pulse wavelength on the quantity of ablated materials. Specifically, this study investigated the structural, optical, and morphological characteristics of tungsten trioxide (WO3) nanoparticles (NPs) that were synthesized using the technique of pulsed-laser ablation of a tungsten plate. A DD drop of water was used as the ablation environment at a fixed fluence at 76.43 J/cm2 and pulse number was 400 pulses of the laser. The first and second harmonic generation ablations were carried out, corresponding to wavelengths of 1064 and 532 nm, respectively. The Q-switched Nd: YAG laser operates at a repetition rate of 1 Hz and has a pulse width of roughly 15 ns. These parameters are applicable to both wavelengths and are maintained at room temperature. Results of the absorption spectra demonstrated that the quantity of material ablated is inversely proportional to the laser pulses' wavelength. FESEM and TEM images show that WO3-NPs, which were prepared by both samples, were spherical. They also show that the wavelength of laser pulses caused an increase in the particle size of NPs. The X-ray diffraction analysis revealed a polycrystalline structure with a preferential orientation along the (220) plane, which corresponded to a diffraction angle of 58.84°. The energy of the optical bandgap of WO3-NPs increases with a decrease in the wavelength of laser pulses, which is calculated to be 3.4 and 3.42 eV for 1064nm and 532 nm wavelengths, respectively. The photoluminescence result agrees well with the estimated optical band gaps.
Klebsiella pneumoniae is one of common hospital-acquired bacteria causing nosocomial pneumonia, urinary tract infections, and intra-abdominal infections. The aim of this study is investigating the Modulation effect of Zinc Oxide nanoparticles (ZnO NPs) against multidrug resistant K. pneumonia which was isolated from Respiratory Tract Infections (RTIs). The results of isolation and characterization of bacterial specimens showed that 20.81% of RTIs were Klebsiella pneumoniae. The strongest isolate showed resistant for most usable antibiotics selected. Simultaneously, ZnO NPs were produced by an aqueous extract of Green Tea leaves as a reducing and stabilizer agent. The Ultraviolet-Visible (UV-Vis) spectrum was indicated a successful produc
... Show MoreBackground: Dental implants provide a unique treatment modality for the replacement of a lost dentition .This is accomplished by the insertion of relatively an inert material (a biomaterial) into the soft and hard tissue of the jaws, there by providing support and retention for dental prostheses. Low level laser therapy (LLLT) is an effective tool used to prompt bone repair and remodeling, this has referred to the biostimulation effect of LLLT. The Aim of this study was to evaluate the effects of inflammatory cells on osseointegration of CpTi implant irradiated by low level laser. Materials and Methods: thirty two adult New Zealand white rabbits, received titanium implants were inserted in the tibia. The right side is considered as experime
... Show MoreIn this work, the spectra for plasma glow produced by pulse
Nd:YAG laser (λ=532 and 1064nm) on Ag:Al alloy with same molar
ratio samples in distilled water were analyzed by studying the atomic
lines compared with aluminum and silver strong standard lines. The
effect of laser energies of the range 300 to 800 mJ on spectral lines,
produced by laser ablation, were investigated using optical
spectroscopy. The electron temperature was found to be increased
from 1.698 to 1.899 eV, while the electron density decreased from
2.247×1015 to 5.08×1014 cm-3 with increasing laser energy from 300
to 800 mJ with wavelength of 1064 nm. The values of electron
temperature using second harmonic frequency are greater than of<
In this work, the optical emission characteristics of the ZnO plasma were presented. The plasma parameters: electron temperature (Te), electron density( ne), plasma frequency (fp) and Debye length (λD) were studied with a spectrometer that collects the spectrum ZnO plasma in air produced by Nd:YAG laser,(λ=1064 nm) at ratio X=0.5 in the range of energy of (700-1000 mJ), duration (10 ns). The Boltzmann plot methodwas employed to calculate the electron temperature (Te), while the Stark broadening was used to determine the electron density (ne), Debye duration (λD), and plasma frequency (fp). Te, ne, and fp
... Show MoreLow-intensity laser irradiation has been explored as an alternative, non-invasive method to encourage chronic wounds to heal. This study aimed to evaluate the effects of low level laser therapy (biostimulation) using semiconductor diode laser with wavelength (785 nm) on the enhancement of chronic wound healing. Fifty patients with chronic wounds were selected to be treated with Low Level Laser Therapy. Their ages ranged between 1 to 76 years. The wound sites were distributed in the lower limb, upper limb, trunk , perineum and head (70%,14%,12%,2%,2%, respectively). Application of laser therapy by noncontact method few millimeters from the skin for 15 minutes per one session twice weekly for two months ; ie,16 sessions for each patient. R
... Show MoreAim: surface modification of titanium using fiber laser 1064 nm to enhance the bond strength to resin cement. Material and Methods: thirty titanium discs of 0.6 cm x 0.3 cm (diameter and thickness respectively) were categorized after preparation into three groups (n=10) as follows: control group with no surface treatment and two test groups were treated with fiber laser after estimation the appropriate parameters in the pilot study which are 81 ns pulse duration, 30,000 Hz frequency, 50 µm spot size and 10,000 mm/s scanning speed and different average power values (10 W and 20 W) depending on the tested group. Titanium discs surface characterization was performed by scanning electron microscope (SEM), a
... Show MoreDue to the scientific and technical development in the free electron laser devices and the accompanying industrial and technological progress in various fields of civil and military life, it became necessary to expand the understanding of the mechanism of interaction of electrons (as an effective medium) with the magnetic field that they pass through to form coherent photons.
In this paper, the Lorentz force effect is simulated and analysed. The results showed that the Lorentz force originates from the magnetic field, making the electron move through it oscillate. This sinusoidal motion of the electron causes it to emit two photons for every electron wavelength. It has been concluded that the electron velocity directly affe
... Show MoreThis study presents the effect of laser energy on burning loss of magnesium from the holes' drilled in aluminum alloy 5052. High energy free running pulsed Nd:Glass laser of 300 µs pulse duration has been used to perform the experiments. The laser energy was varied from 1.0 to 8.0 Joules, The drilling processes have been carried out under atmospheric pressure and vacuum inside a specially designed chamber. Microhardness of the blind drilled holes has been investigated .The results indicated that the magnesium loss could be manipulated by adjusting the focusing conditions of the laser beam. Almost, the obtained holes were free of cracks with low taper and low sputter deposition. .The holes performed under atmospheric conditions have high
... Show MoreThe paper include study the effect thickness of the polymeric sample which is manufactured by thermo press way. The sample was used as an active tunable R6G laser media. The remarks show that, when the thickness of the samples is increased, with the same concentration, the spectrum will shift towards the short wavelength, & the quantum fluorescence yield will increased. The best result we obtained for the quantum fluorescence yield is (0.68) at the sample, with thickness (0.304mm) in Ethanol solvent, while when we used the Pure Water as a solvent, we found that the best quantum fluorescence yield is (0.63) at (0.18mm) thickness of the sample.
A numerical investigation has been performed to examine the effect of fluorine concentration on the chain reaction mechanisms and parameters of hydrogen fluoride (HF) chemical laser. The practical difficulties associated with this type of lasers impose that an alternative route might be quite useful. Thus, particular attention was paid to develop a computer program to investigate various processes. The results of this computer simulation program proved their credibility when compared with the little published data. This computer program is called Reaction Rate Simulation Model (RRSM). An entirely new approach to emulate the reaction mechanisms has been followed. The effectiveness of reaction rates in the processes of HF lase
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