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.
In this work Laser wireless video communication system using intensity modualtion direct
detection IM/DD over a 1 km range between transmitter and receiver is experimentally investigated and
demonstrated. Beam expander and beam collimeter were implemented to collimete laser beam at the
transmitter and focus this beam at the receiver respectively. The results show that IM/DD communication
sysatem using laser diode is quite attractive for transmitting video signal. In this work signal to noise
ratio (S/N) higher than 20 dB is achieved in this work.
Laser is a powerful device that has a wide range of applications in fields ranging from materials science and manufacturing to medicine and fibre optic communications. One remarkable
This study aims to fabricate and assess the β-tricalcium phosphate (β-TCP) bioactive ceramic coat layer on bioinert ceramic zirconia implants through the direct laser melting technique by applying a long-pulsed Nd:YAG laser of 1064 nm. Surface morphologies, adherence, and structural change in the coatings were evaluated by optical microscopy, field emission scanning electron microscope, hardness, and x-ray diffractometer. The elastic modulus (EM) of the coating was also determined using the nanoindentation test. The quality of the coating was improved when the laser power was 90 W with a decrease in the scan speed to 4 mm s−1. The chemical composition of the coat was maintained after laser processing; also, the Energy Dispersive
... Show MoreThe compressive residual stresses generated by shot peening, is increased in a direct proportional way with shot peening time (SPT). For each metal, there is an optimum shot peening time (O.S.T) which gives the optimum fatigue life. This paper experimentally studied to optimize shot peening time of aluminium alloy 6061-T651 as well as using of and analysis of variance (ANOVA).
Two types of fatigue test specimens’ configuration were used, one without notch (smooth) and the other with a notch radius (1,25mm), each type was shot peened at different time. The (O.S.T) was experimentally estimated to be 8 minutes reaching the surface stresses at maximum peak of -184.94 MPa.
A response surface methodology (RSM) is presen
... Show MoreSuperconducting thin films of Bi1.6Pb0.4Sr2Ca2Cu2.2Zn0.8O10 system were prepared by depositing the film onto silicon (111) substrate by pulsed laser deposition. Annealing treatment and superconducting properties were investigated by XRD and four probe resistivity measurement. The analysis reveals the evolution of the minor phase of the films 2212 phase to 2223 phase, when the film was annealed at 820 °C. Also the films have superconducting behavior with transition temperature ≥90K.
Cervical ectropion is considered to be a physiologic condition caused by columnar epithelium migration from the cervical canal into the vaginal portion of the cervix and usually there is no treatement for clinically asymptomatic cervical ectropion . Treatment can be achieved by thermal cauterization (Electrocautery), Cryosurgery or laser vaporization. Aim of the study: To study the effectiveness of CO2 laser (10600nm) in treatment of symptomatic cervical ectropion . Setting: The study was carried out at Laser Medicine Research Clinic at the Institute of Laser for Postgraduate Studies, University of Baghdad between the first of August 2013 to the end of October 2013. Patients and Methods: Ten female Patients with age range between 25-48 y
... Show MoreSeveral types of laser are used in experimental works in order to study the effects of laser on blood vessel. They differ from each other by a lot of properties mainly in wavelength, energy of the laser and pulse duration. In this study argon laser (488 nm- 514 nm) and continuous Nd: YAG laSer (1064 nm), have been applied to 50 samples of sheep blgod tesselS. Histologically, tha results of the study were different According to the txpe of L`sar used; apgon larer had distrabtave effects on $he blood vessal while continuous Nd: YAG laser Appeaped to be the safesd one on the blmod vessel architecture. This study concluded that argoj laser has da-aging ef&ect on
... Show MoreIn this research study the effect of irradiation by (CW) CO2 laser on some optical properties of (Cds) doping by Ni thin films of (1)µm thickness has been prepared by heat evaporation method. (X-Ray) diffraction technique showed the prepared films before and after irradiation are ploy crystalline hexagonal structure, optical properties were include recording of absorbance spectra for prepared films in the range of (400-1000) nm wave lengths, the absorption coefficient and the energy gap were calculated before and after irradiation, finally the irradiation affected (CdS) thin films by changing its color from the Transparent yellow to dark rough yellow and decrease the value absorption coefficient also increase the value of energy gap.
In an attempt to disposal from nuclear waste which threats our health and environments. Therefore we have to find appropriate method to immobilize nuclear waste. So, in this research the nuclear waste (Strontium hydroxide) was immobilized by Carbon nanotubes (CNTs). The Nd-YAG laser with wave length 1064 nm, energy 750 mJ and 100 pulses used to prepare CNTs. After that adding Sr(HO)2 powder to the CNTs colloidal in calculated rate to get homogenous mixing of CNTs-Sr(OH)2. The Sr(HO)2 absorbs carbon dioxide from the air to form strontium carbonate so, the new solution is CNTs-SrCO3. To dry solution putting three drops from the new solution on the glass slides. To investigate the radi
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