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Experimental and Numerical Analysis of Laser Surface Melting by Using Enthalpy Method
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Abstract<p>In this study, experimental and numerical applied of heat distribution due to pulsed Nd: YAG laser surface melting. Experimental side was consists of laser parameters are, pulse duration1.3<italic>ms</italic>, wavelength 1064nm, laser energies 1.5, 2. 6 and 4.3 J, laser beam diameter is 0.6 mm and spot diameter 0.78 mm was applied a low carbon steel type St37 with a dimension 10, 10, 3 mm, length, width and thickness respectively. Numerical analysis side consist of a mathematical model and calculating a thermal cycle by using equation in the enthalpy method applied to determine the cooling rate in fusion zone. The simulation by using the enthalpy method, applied on conduction heat transfer to estimate the cooling rate model in fusion zone and heat affected zones. Cooling rates models are helping to estimate the microstructure and micro hardness distribution in fusion and heat affected zones. The complication of the heat transfer in laser surface melting process, because at in rapid solidification, therefore the enthalpy model is more appropriate for this case. The result shows that increases of laser energy lead to decrease cooling rates and increase width and penetration of fusion zone, also decrease micro hardness in fusion zone and we found an increase in the pool size of fusion and heat affected zones.</p>
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Publication Date
Tue Nov 30 2021
Journal Name
Iraqi Journal Of Science
Measurement and Analysis of Natural Radioactive Elements in Salty Sediments from Central and Southern Iraq
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Purification of fifteen NaCl samples from natural and different area in the middle and south of Iraq are prepared  and studied the structural characteristics of samples by powder X-ray diffraction analysis at 𝛌=1.542Ã…. The present work considered the specific activities of naturally occurring radioactive materials in salt samples, which are measured and analyzed using high resolution HPGe system. Also, the radiological parameters have been considered in this work. The average specific concentration (in Bq.kg-1) of the salt samples is found 16.864.92 for 226Ra, 5.972.05 for 232Th and 9.852.8 for 40K, respectively, which are below the national levels, 40Bq.kg-1, 30Bq.k

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Publication Date
Sun Jun 11 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Determine the Biofilm Formed by Using ELISA Technology for Gram-Negative Bacteria Isolated from Wounds and Burns Infections, and the Study of the Production of the Biofilm Molecularly.
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    This study was designed to investigate the capability of gram-negative bacteria that isolated form wound and burn infection to production of Biofilm which included (32) isolates, which have multi – drug resistant to antibiotics. The isolates included (10) Pseudomonas aeruginosa, (9) Klebsiella pneumoniae, (6) Escherichia coli, (5) Proteus mirabilis and (2) Enterobacter cloacae. The method used method links the crystal violet with biofilm and reading by ELISA which was adopted on the values of optical density of violets that linked to the mass of biofilm at the wavelength of (620) nm, the test results showed variation of biofilm composition for all bacterial species depending on the optical density value while th

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Publication Date
Tue Sep 01 2009
Journal Name
Al-khwarizmi Engineering Journal
Stress Analysis of Guide Rails of Elevators
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The mechanical design of elevator elements is always performed by international standards. The engineer selects the appropriate elements of elevator according to catalogues without knowing scientific details. Therefore, a theoretical analysis is achieved at two operating conditions for guide rails (1) safety gear operation, and (2) running condition with the loads unevenly distributed on the elevator car. The guide rail is considered a continuous beam with variable supports. Then the British code is listed showing the equations used in it.

The theoretical equations showed that guide rails are never subjected to stress in simultaneous combined buckling and bending in the plane, where the bending moment is exerted. It is always a c

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Publication Date
Mon Jan 29 2018
Journal Name
Environmental Earth Sciences
A preliminary assessment of the geochemical factors affecting groundwater and surface water quality around the rural communities in Al-Anbar, Western Desert of Iraq
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Publication Date
Wed Dec 15 2004
Journal Name
Iraqi Journal Of Laser
Evaluation of 532 nm Laser Effect on Dental Enamel Dissolution: In Vitro Study
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to evaluate the effect of various Nd:YAG frequency doubled laser parameters on the acid
dissolution and the progression of in vitro caries like lesions in human enamel.
Materials and Methods: Human extracted caries free upper first premolar teeth were collected for
this study. The irradiated teeth were divided into two groups. The first group was irradiated with
continuous Nd:YAG laser radiation, and the second group was irradiated with chopped Nd:YAG laser
radiation. For the first group, power and exposure time were changed while for the second group
power and number of pulses were changed. The spot diameter was kept constant for all the samples.
Results: using 1.5 W and 3 seconds (exposure time), best results among

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Publication Date
Tue Jan 08 2019
Journal Name
Iraqi Journal Of Physics
Preparation of Ag nanoparticles via pulsed laser ablation in liquid for biological applications
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Ag nanoparticles were prepared using Nd:YAG laser from Ag matel in distilled water using different energies laser (100 and 600) mJ using 200 pulses, and study the effect of the preparation conditions on the structural characteristics of and then study the effect of nanoparticles on the rate of killing the two types of bacteria particles (Staph and E.coli). The goal is to prepare the nanoparticle effectively used to kill bacteria.

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Publication Date
Tue Oct 08 2002
Journal Name
Iraqi Journal Of Laser
Cross-focusing Effect of Two Intense Laser Beams on Electron Plasma Wave Excitation
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This paper presents the effect of relativistic and ponderomotive nonlinearity on cross-focusing of two intense laser beams in a collisionless and unmagnetized plasma. It should be noted here that while considering the self-focusing due to relativistic electron mass variation, the electron ponderomotive density depression in the channel may also be important. Therefore/these two nonlinearties may simultaneously affect the self-focusing process. These nonlinearities depend not only on the intensity of one laser but also on the second laser. Therefore, one laser beam affects the dynamics of the second beam and hence the process of cross-focusing takes place. The electric field amplitude of the excited electron plasma wave (EPW) has been cal

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Publication Date
Fri Feb 08 2019
Journal Name
Iraqi Journal Of Laser
Laser Induced Fluorescence Spectroscopy of Decamethylrhenocene ( - C5 Me5)2 Re in Supersonic Jet
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In this paper we report the use of supersonic jet laser induced fluorescence (LIF) spectroscopy to facilitate the study of the spectra of some organometallic sandwich compounds particularly the metallocenes. The charge-transfer processes within these compounds, especially ligand to metal charge transfer within decamethylrhenocene ( - C5 Me5)2 Re were of particular interest. The spectrum shows a high degree of structures, indicating that there are several levels populated and these molecules are able to undergo many possible transitions

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Publication Date
Tue Feb 12 2019
Journal Name
Iraqi Journal Of Laser
Effects of Ho: YAG Laser (2100nm) in Prostate Tissue: An in vitro Study
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Benign prostate hyperplasia (BPH), non-cancerous enlargement of prostate, is the most prevalent disease entity in elderly men. BPH affects 40% of men after the age of 60year worldwide. BPH causes problems for patients with significant lower urinary tract obstructive symptoms, if not responding to medical therapy, surgical intervention is instituted. One method of the treatment of symptomatic BPH is laser prostatectomy. The understanding of tissue effects by laser radiation is very important for the safe clinical application of laser. Objective: study the 2100 nm Ho: YAG laser gross tissue effects in the prostate at different laser dose settings in an vitro model prostate tissue samples harvested from same specimen of open surgery prostat

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Publication Date
Fri Dec 01 2023
Journal Name
Baghdad Science Journal
Numerical Investigation of Physical Parameters in Cardiac Vessels as a New Medical Support Science for Complex Blood Flow Characteristics
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This study proposes a mathematical approach and numerical experiment for a simple solution of cardiac blood flow to the heart's blood vessels. A mathematical model of human blood flow through arterial branches was studied and calculated using the Navier-Stokes partial differential equation with finite element analysis (FEA) approach. Furthermore, FEA is applied to the steady flow of two-dimensional viscous liquids through different geometries. The validity of the computational method is determined by comparing numerical experiments with the results of the analysis of different functions. Numerical analysis showed that the highest blood flow velocity of 1.22 cm/s occurred in the center of the vessel which tends to be laminar and is influe

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