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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
Thu Apr 18 2024
Journal Name
Geomatics And Environmental Engineering
Error Analysis of Stonex X300 Laser Scanner Close-range Measurements
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This research reports an error analysis of close-range measurements from a Stonex X300 laser scanner in order to address range uncertainty behavior based on indoor experiments under fixed environmental conditions. The analysis includes procedures for estimating the precision and accuracy of the observational errors estimated from the Stonex X300 observations and conducted at intervals of 5 m within a range of 5 to 30 m. The laser 3D point cloud data of the individual scans is analyzed following a roughness analysis prior to the implementation of a Levenberg–Marquardt iterative closest points (LM-ICP) registration. This leads to identifying the level of roughness that was encountered due to the range-finder’s limitations in close

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Publication Date
Thu Dec 15 2011
Journal Name
Iraqi Journal Of Laser
Laser Hole Drilling of Stainless Steel 321H and Steel 33 Using 3D CO2 Laser CNC Machine
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In present work an investigation for precise hole drilling via continuous wave (CW) CO2 laser at 150 W maximum output power and wavelength 10.6 μm was achieved with the assistance of computerized numerical controlled (CNC) machine and assist gases. The drilling process was done for thin sheets (0.1 – 0.3 mm) of two types of metals; stainless steel (sst) 321H, steel 33 (st). Changing light and process parameters such as laser power, exposure time and gas pressure was important for getting the optimum results. The obtained results were supported with computational results using the COMSOL 3.5a software code.

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Publication Date
Wed May 29 2019
Journal Name
Iraqi Journal Of Physics
Improvement the efficiency of SnO2/n-Si detector by engraving method using a CNC machine
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Tin oxide was deposited by using vacuum thermal method on silicon wafer engraved by Computer Numerical Controlled (CNC) Machine. The inscription was engraved by diamond-made brine. Deep 0.05 mm in the form of concentric squares. Electrical results in the dark were shown high value of forward current and the high value of the detection factor from 6.42 before engraving to 10.41 after engraving. (I-V) characters in illumination with powers (50, 100, 150, 200, 250) mW/cm2 show Improved properties of the detector, Especially at power (150, 200, 250) mW/cm2. Response improved in rise time from 2.4 μs to 0.72 μs and time of inactivity improved 515.2 μs to 44.2 μs. Sensitivity angle increased at zone from 40o to 65o.

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Publication Date
Thu Jan 31 2019
Journal Name
Journal Of Engineering
Estimation of Cutoff Values by Using Regression Lines Method in Mishrif Reservoir/ Missan oil Fields
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Net pay is one of the most important parameters used in determining initial oil in place of a reservoir. It can be delineated through the using of limiting values of the petrophysical properties of the reservoir. Those limiting values are named as the cutoff. This paper provides an insight into the application of regression line method in estimating porosity, clay volume and water saturation cutoff values in Mishrif reservoir/ Missan oil fields. The study included 29 wells distributed in seven oilfields of Halfaya, Buzurgan, Dujaila, Noor, Fauqi, Amara and Kumait.

This study is carried out by applying two types of linear regressions: Least square and Reduce Major Axis Regression.

The Mishrif formation was

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Publication Date
Sun Jun 07 2009
Journal Name
Baghdad Science Journal
Changes of the susceptibility of Staphylococcus aureus bacteria to the local therapeutic agent by using Nitrogen laser
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This study involves the investigation of the effect of nitrogen laser with 337.1 nm wavelength on the sensitivity of Staphylococcus aureus bacteria by using local therapeutic due to burns. Thirty six isolate of Staphylococcus aureus bacteria were isolated from 25 patients suffering from sever burns, each isolate of bacteria was irradiated with nitrogen laser at (5, 10, 15 and 30) pulses/second repetition rates for 1, 5, 10, 20 and 30 minutes for each repetition rate. The effects of nitrogen laser on the local therapeutics sensitivity of bacteria were obtained using Kirby Baur method. Changes in the sensitivity of bacteria to local therapeutics (Tetracyclin, Chloramphenicol, Flumizin and Fucidin) occur at high repetition rate(30 pulses/seco

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Publication Date
Wed Sep 30 2020
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Digital Rock Samples Porosity Analysis by OTSU Thresholding Technique Using MATLAB
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Porosity plays an essential role in petroleum engineering. It controls fluid storage in aquifers, connectivity of the pore structure control fluid flow through reservoir formations. To quantify the relationships between porosity, storage, transport and rock properties, however, the pore structure must be measured and quantitatively described. Porosity estimation of digital image utilizing image processing essential for the reservoir rock analysis since the sample 2D porosity briefly described. The regular procedure utilizes the binarization process, which uses the pixel value threshold to convert the color and grayscale images to binary images. The idea is to accommodate the blue regions entirely with pores and transform it to white in r

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Publication Date
Sat Apr 01 2017
Journal Name
Applied Energy
Melting enhancement in triplex-tube latent heat energy storage system using nanoparticles-metal foam combination
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Publication Date
Wed Mar 18 2020
Journal Name
Baghdad Science Journal
A Hybrid Method of Linguistic and Statistical Features for Arabic Sentiment Analysis
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          Sentiment analysis refers to the task of identifying polarity of positive and negative for particular text that yield an opinion. Arabic language has been expanded dramatically in the last decade especially with the emergence of social websites (e.g. Twitter, Facebook, etc.). Several studies addressed sentiment analysis for Arabic language using various techniques. The most efficient techniques according to the literature were the machine learning due to their capabilities to build a training model. Yet, there is still issues facing the Arabic sentiment analysis using machine learning techniques. Such issues are related to employing robust features that have the ability to discrimina

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Publication Date
Sun Jun 04 2017
Journal Name
Baghdad Science Journal
Analysis and Study of the Effect of Atmospheric Turbulence on Laser weapon in Iraq
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One of the most important challenges facing the development of laser weapons is represented by the attenuation of the laser beam as it passed through the layers of atmosphere.This paper presents a theoretical study to simulate the effect of turbulence attenuation and calculates the decrease of laser power in Iraq. The refractive index structure C_n^2 is very important parameter to measure the strength of the atmospheric turbulence, which is affected by microclimate conditions, propagation path, season and time in the day. The results of measurements and predictions are based on the Kolmogorov turbulence theory. It was demonstrated by simulations that the laser weapons in Iraq were severely affected due to the large change in temperatures,

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Publication Date
Sat Oct 28 2023
Journal Name
Baghdad Science Journal
Experimental Investigation of the Mechanical and Structural Properties of a Functionally Graded Material by Adding Alumina Nanoparticles Using A Centrifugal Technique
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In this work, functionally graded materials were synthesized by centrifugal technique at different
volume fractions 0.5, 1, 1.5, and 2% Vf with a rotation speed of 1200 rpm and a constant rotation time, T
= 6 min . The mechanical properties were characterized to study the graded and non-graded nanocomposites
and the pure epoxy material. The mechanical tests showed that graded and non-graded added alumina
(Al2O3) nanoparticles enhanced the effect more than pure epoxy. The maximum difference in impact strength
occurred at (FGM), which was loaded from the rich side of the nano-alumina where the maximum value was
at 1% Vf by 133.33% of the sample epoxy side. The flexural strength and Young modulus of the fu

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