In this work, the copper metal was treated using Nd:YAG laser with energy 1Joul to enhance corrosion resistance and improve surface properties. The copper metal has many applications in industry as well as water, oil and gas pipes. The same conditions, (laser power density, scan speed, distance between paths, medium gas-air) were applied in the laser surface treatment, After laser treatment, the samples microstructures were investigated using optical microscope (OM) to examine micro structural changes due to laser irradiation. Specimen surfaces were investigated using atomic force microscopy (AFM), X-ray diffraction (XRD), macro hardness, and corrosion test before and after laser treatment to examine the surface properties changes as a result of laser irradiation, and X-ray fluorescence (XRF). Results showed that laser irradiation enhances the corrosion resistance of the metal copper. Corrosion rates as low as 0.550 mpy for laser treated samples were obtained in comparison to 0.699 mpy obtained for the untreated samples. The corrosion protection afforded by laser treatment is attributed mainly to the grain refinement of the top surface layer. This layer is found to consist of nano-scale grains. Higher hardness and lower average roughness due to laser surface treatment.
The inverse kinematics of redundant manipulators has infinite solutions by using conventional methods, so that, this work presents applicability of intelligent tool (artificial neural network ANN) for finding one desired solution from these solutions. The inverse analysis and trajectory planning of a three link redundant planar robot have been studied in this work using a proposed dual neural networks model (DNNM), which shows a predictable time decreasing in the training session. The effect of the number of the training sets on the DNNM output and the number of NN layers have been studied. Several trajectories have been implemented using point to point trajectory planning algorithm with DNNM and the result shows good accuracy of the end
... Show MoreThe main aim of this research to study and recognize the specifications and main concepts of (Fuzzy Logic) and its components and studying the practical experiments of the (Fuzzy Logic) techniques in the electrical engineering field through by using the (Fuzzy Logic) for controlling the three-phase AC induction motor by using (Matlab_ simulation_7) for modeling the system by using the computer
This research aims at investigating pupils’ ability in using discourse markers which are identified in the English textbooks of secondary schools. Four texts are chosen from third intermediate class. The four texts are short stories of different topics.
This research hypothesizes that there are no statistical significant differences among Iraqi intermediate pupils’ ability in using textual
... Show MoreThis research was conduct to evaluate the cytotoxic effect of exotoxin A (ETA) produced by Pseudomonas aeruginosa on mice in comparison with (phosphate buffer saline (PBS) as a negative control. The effect of the toxin was measured by employing the cytogenetic analysis which included (the mitotic index (MI), chromosomal aberrations (CAs), micronucleus (MN) and sperm abnormalities) parameters. In order to specify the cytotoxic effect of the toxin, three doses of ETA (125, 250 and 500 ng/ml) were used. Results showed that ETA was found to cause a significant decrease in mitotic index (MI) percentage, while significant increase in micronucleus (MN), chromosomal aberrations (CAs) and sperm abnormalities parameters in compression with control wa
... Show MoreA detailed study of adsorption from solution of amitriptyline-HCl, chlorpromazine-HCl and
chlordiazepoxide-HCl on bentonite clay surface has been performed at variable conditions of
temperature, pH and ionic strength. It is aimed in this work to explore the capability of this clay in
treatment of poisoning by the mentioned drugs if taken in quantities higher than the usual doses.
Quantities of drugs adsorbed have been determined by UV spectrophotometric technique. The
sequence of adsorption in neutral media at 37.5 CÙ’ followed the order:
Amitriptyline-HCl > chlorpromazine-HCl > chlordiazepoxide-HCl.
The results were discussed in the light of Langmuir and Freundich adsorption isotherms. The usual
basic th
This work aimed to investigate the effect of Diode laser 805 nm on plasmid DNA and RNA
contents of some Gram negative bacteria represented by Escherichia coli and Proteus mirabilis isolates
.Plasmid extraction was done using two methods (Salting out and CTAB method).Different powers and
pulse repetition rates for 805 nm Diode Laser were used to study this effect. Results revealed that the
plasmid profile of the two species were highly affected using (2, 3) W at different frequencies including
5and 10 kHz as compared with 1 kHz while plasmids were gradually disappeared at 1W, 10 kHz. In the
same time the shining of RNA was also decreased gradually then disappeared with increasing powers
especially at 2W and 10 kHz cau
Background: The demand for esthetic orthodontic appliances is increasing; so the esthetic orthodontic archwires were introduced. Among them, Teflon and Epoxy coated stainless steel archwires. The amount of force available from the archwire depends on the structural properties and susceptibility to corrosion. All metallic alloys are changed during immersion in artificial saliva, chlorhexidine mouthwash andtoothpaste, but their behaviors differ from one type to another. They corrode at different rates, which lead to decrease the amount of force applied to the teeth. This in vitro study was designed to evaluate the corrosion pits in stainless steel archwires coated with Teflon and with Epoxy in dry and after immersion in artificial saliva, chl
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