The microstructures of rapidly solidified laser clad layers of laser cladding of Inconel 617 with different nickel-aluminum premixed clad powders are discussed. The effect of different cladding speeds on the microstructures of rapidly solidified laser clad layers is discussed too. The detailed microstructural results showed that different growth mechanisms are produced during rapid solidification. These are planar, cellular, cellular/dendritic and dendritic.
The regression analysis process is used to study and predicate the surface response by using the design of experiment (DOE) as well as roughness calculation through developing a mathematical model. In this study; response surface methodology and the particular solution technique are used. Design of experiment used a series of the structured statistical analytic approach to investigate the relationship between some parameters and their responses. Surface roughness is one of the important parameters which play an important role. Also, its found that the cutting speed can result in small effects on surface roughness. This work is focusing on all considerations to make interaction between the parameters (position of influenc
... Show MoreIn this work; Silicon dioxide (SiO2) plasma plume was prepared by laser induced plasma (LIP). The electron number density, plasma frequency and Debye length were calculated by reading the data of I-V curve of Langmuir probe which was used as a diagnostic method of measuring plasma properties. Pulsed Nd:YAG laser was used for measuring the electron number density of SiO2 plasma plume under vacuum environment with varying both vacuum pressure and axial distance from the target surface. Some physical properties of the plasma generated such as electron density, plasma frequency and Debye length have been measured experimentally and the effects of vacuum pressure and Langmuir probe distance from the target were studied on those variables. An
... Show MoreThe subject of biophysics is interdisciplinary and covers various fields of biology and physics. In this research the effect of some parameters of Nd:YAG laser on ants (Camponotus consobrinus) has been studied . This includes the effect on its external shape, as well as the percentage of the killing rate obtained. A laser radiation of a wavelength (1.064 µm) with different energies: (300, 320, 340, 360, 380 and 480 mJ) was used to irradiate ants placed at a distance of (10 cm) distance from the laser source . The irradiation times were (15 and 20 sec) for each energy. The obtained results showed an increase in the rate of ant mortality, as well
... Show MoreModern emerged technologies impose development and fabrication of miniatur-ized parts and devices in the micro- and nano-scale. Producing micro- and nano-featured structures requires nonconventional machining processes where con-ventional machining processes such as grinding, milling and eroding have failed. New emerging processes, such laser machining processes, are still fraught with almost invincible processes. Micro-/nano-machining are the pro-cesses of producing parts, microsystems or features at a scale of a few microm-eters and less than one hundred nanometers, respectively. Precise cutting and clean material removal accompanied with a negligible heat affected zone (HAZ), which are usually the characteristics of laser ablation, have
... Show MoreLaser beam has been widely used to improve the mechanical properties of the metals. It used for cutting, drilling, hardening, welding……etc. The use of Laser beam has many features in accuracy and speeding in work, also in the treatment of metals locally, and in the places that is hard to reach by traditional ways. In this research a surface treatment was done to medium carbon steel (0.4%C) which is common kind of steel that is used in industry. Pulsing Neodymium -YAG Laser has been used and 1.06 micrometer wave length and 5 msec and the distance is about 30 centimeter between the exit area of the Laser beam from the system and the piece that treated . We are going to check the fatigue resistance for samples that is
... Show MoreIn this paper, an experimental study has been conducted regarding the indication of resonance in chaotic semiconductor laser. Resonant perturbations are effective for harnessing nonlinear oscillators for various applications such as inducing chaos and controlling chaos. Interesting results have been obtained regarding to the effect of the chaotic resonance by adding the frequency on the systems. The frequency changes nonlinear dynamical system through a critical value, there is a transition from a periodic attractor to a strange attractor. The amplitude has a very relevant impact on the system, resulting in an optimal resonance response for appropriate values related to correlation time. The chaotic system becomes regular under
... Show MoreHemorrhoids are one of the most common surgical conditions. The hemorrhoid may cause symptoms that are: bleeding, pain, prolapse, itching, spoilage of feces, and psychologic discomfort. There are many methods for treatment of hemorrhoid like, medical therapy, rubber band ligation, electerocoagulation, stapled hemorrhoidpexy, photocoagulation, sclerothereapy, doppler guided artery ligation, Cryosurgery, and surgery. All methods for treatment of hemorrhoids have advantages, disadvantages, and limitations. Conventional haemorrhoidectomy was the traditional operation for the treatment of hemorrhoids. But recently other modalities of treatment had been used as an alternative operations including CO2 laser haemorrhoidectomy. This work aims to
... Show MoreIn this work the design and construction of a flash photolysis pulsed HCl laser was presented. The parameters of the pumping source and discharge current density was obtained, which sufficient to shift the flash lamp spectrum towards uv portion of spectrum. The maximum pulse laser energy parameters was measured. Total pressure and ratio of active gases to optimized the output pulse energy were measured , where at 125 mbar of total pressure and 1:7:14 Cl2:H2: He ratio, the laser energy was measured to be 200 mJ at pumping four flash lamps energy in the order of 6400J .The resonator consists of copper a near hemispherical mirror with the radius of curvature 3m coated by gold and reflectivity 98%,the output coupler sapphire mirror of
... Show MoreThe synthesis of nanoparticles (GNPs) from the reduction of HAuCl4 .3H2O by aluminum metal was obtained in aqueous solution with the use of Arabic gum as a stabilizing agent. The GNPs were characterized by TEM, AFM and Zeta potential spectroscopy. The reduction process was monitored over time by measuring ultraviolet spectra at a range of λ 520-525 nm. Also the color changes from yellow to ruby red, shape and size of GNP was studied by TEM. Shape was spherical and the size of particles was (12-17.5) nm. The best results were obtained at pH 6.
The research included preparation of new iron(II) complexes with mixed ligands including benzilazine(BA) and semicarbazone ligands {benzilsemicarbazone- BSCH or benzilbis(semicarba-zone)- BBSCH2 or salicylaldehydesemicarbazone- SSCH2 or benzoinsemicarbazone- B'SCH2}.by classical and microwave methods. The resulted complexes have been characterized using chemical and physical methods. The study suggested that the above ligands form ionic complexes having formulae [Fe(SCHi)(BA)(Cl)m](Cl)2-m {where SCH, BSCH, BBSCH2, SSCH¬2 or B'SCH2 ligands; m=1 or 2}. Hexacoordinated mononuclear complexes have been investigated by this study and having octahedral geometries. The effect of laser ray type visible region have been studied on solid ligands and
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