Objectives This work presents laser coating of grade 1 pure titanium (Ti) dental implant surface with sintered biological apatite beta-tricalcium phosphate (β-TCP), which has a chemical composition close to bone. Materials and methods Pulsed Nd:YAG laser of single pulse capability up to 70 J/10 ms and pulse peak power of 8 kW was used to implement the task. Laser pulse peak power, pulse duration, repetition rate and scanning speed were modulated to achieve the most homogenous, cohesive and highly adherent coat layer. Scanning electron microscopy (SEM), energy dispersive X-ray microscopy (EDX), optical microscopy and nanoindentation analyses were conducted to characterise and evaluate the microstructure, phases, modulus of elasticity of the coating layer and calcium-to-phosphate ratio and composition. Results showed that the laser power and scanning speed influenced coating adherence. The cross-sectional field-emission scanning electron microscopy images at low power and high speed showed poor adherence and improved as the laser power increased to 2 kW. Decreasing the scanning speed to 0.2 mm/s at the same power of 2 kW increased adherence. EDX results of the substrate demonstrated that the chemical composition of the coat layer did not change after processing. Moreover, the maps revealed proper distribution of Ca and P with some agglomeration on the surface. The sharp peaks on the X-ray diffraction patterns indicated that β-TCPs in the coat layer were mostly crystalline. The elastic modulus was low at the surface and increased gradually with depth to reach 19 GPa at 200 nm; this value was close to that of bone. The microhardness of the coated substrate increased by about 88%. The laser pulse energy of 8.3 J, pulse peak power of 2 kW, pulse duration of 4.3 min, repetition rate of 10 Hz and scanning speed of 0.2 ms−1 yielded the best results. Conclusion: Both processing and coating have potential use for dental implant applications.
Zinc Oxide thin film of 2 μm thickness has been grown on glass substrate by pulsed laser deposition technique at substrate temperature of 500 oC under the vacuum pressure of 8×10-2 mbar. The optical properties concerning the absorption, and transmission spectra were studied for the prepared thin film. From the transmission spectra, the optical gap and linear refractive index of the ZnO thin film was determined. The structure of the ZnO thin film was tested with X-Ray diffraction and it was formed to be a polycrystalline with many peaks.
In this work, the Al-Mg alloys plasma plume that produced under vacuum (10-1 torr) by Nd:Yag Laser was studied. the plasma spectra were analyzed by comparing the atomic lines of Al and Mg lines with standard lines. The effect of laser energies on spectral lines produced by laser ablation were investigated using optical
spectroscopy .several plasma characteristics like electron temperature, electron density, Debye’s length, plasma frequency and number of particles in the ‘‘Debye’s Sphere’’ were calculated in vacuum .The results show the electron temperature and electron density increase in magnesium, aluminum and magnesium :aluminum alloy
targets . It was found that the lines intensities at
Pulsed laser ablation in liquid (PLAL) has become an increasingly important technique for metals production and metal oxides nanoparticles (NPs) and others. This technique has its many advantages compared with other conventional techniques (physical and chemical). This work was devoted for production of zirconia (ZrO2) nanoparticles via PLAL technique from a solid zirconium target immersed in a wet environment in order to study the effect of this environment on the optical properties and structure of ZrO2 nanoparticles. The solutions which used for this purpose is distilled water (D.W). The produces NPs were characterized by mean of many tests such as UV-visible (UV-Vis.), transmission electron microscope (TEM) and Z-Potential. The UV-Vis.
... Show MoreThe applications of hot plasma are many and numerous applications require high values of the temperature of the electrons within the plasma region. Improving electron temperature values is one of the important processes for using this specification in plasma for being adopted in several modern applications such as nuclear fusion, plating operations and in industrial applications. In this work, theoretical computations were performed to enhance electron temperature under dense homogeneous plasma. The effect of power and duration time of pulsed Nd:YAG laser was studied on the heating of plasmas by inverse bremsstrahlung for several values for the electron density ratio. There results for these ca
... Show MoreThis work aims to investigate the inhibition of vitality of Streptococcus mutans, which is the causative agent of caries. A 632.8 nm He-Ne laser with the output power of 4.5mW was used in combination with toluidine blue O (TBO) at the concentration of 50μg/ml as a photosensitizer. Streptococcus mutans was isolated from 35 patients if carious teeth. Three isolates were chosen and exposed to different energy densities of He – Ne laser light 3.8, 11.7, 34.5 and 104.1 J/cm². After irradiation, substantial reduction was observed in the number of colony forming units (CFU)/ ml. The reduction in the number of CFU was increasing as the dose increased.
A simple, new, and sensitive spectrophotometric technique for the determination of methyldopa was presented in this research article. The suggested technique includes reacting metoclopramide with NaNO2 in the presence of hydrochloric acid to produce diazonium salt, and then the drug methyldopa reacts with the diazonium salt to produce a yellow azo dye. The maximum wavelength of the dye was 458 nm. This method is effectively used for the determination of methyldopa in different pharmaceutical formulations. It has been found that there are no significant interactions between common excipients and pure methyldopa. The results were processed statistically, and compared with those obtained from officially approved methods, they were found to be
... Show MorePure Polyaniline salt, and protonation PANI by H2SO4 were synthesized by electro-chemical oxidative polymerization of aniline with acidity of H2SO4. The solution was prepared in reaction temperature equal 291 K and the acidity of aqueous solution was 1 molarities. The prepared polyaniline was characterized by FT-IR, the result indicate that the intensity is increase with increasing of applied voltage. The dc conductivity has been measured for bulk polyaniline pure and doped in the form of compressed pellet with evaporated Ohmic Al electrodes in temperature range (303-423) K. The Eav energy of the thermal rate process of the electrical conductivity was determined. The results indicate that the dc conductivity of doped samples are two or t
... Show MoreBackground: A tattoo is a foreign material implanted into the dermis by needle or some other trauma that
results in a visible mark in the skin .either decorative or cosmetic tattoos or may be traumatic tattoos
resulting from car accident or iatrogenic tattoos placed in radiation ports. There are many ways for tattoo
removal one of them is laser treatment by Q-Switched (1064 nm and 532 nm) Nd: YAG Laser.
Objectives: The purpose of this study is to evaluate the efficacy and safety of Q-Switched Nd: YAG (1064 &532 nm) Laser in treatment of tattoos.
Patient and Method: Nineteen lesions of tattoo in different body sites in nine patients collected in private
plastic surgery clinic in