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Determining the Optimum Reference Orbits Using Lagrange’s Series for Geocentric Satellite in Low Earth Orbit
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The Taylor series is defined by the f and g series. The solution to the satellite's equation of motion is expanding to generate Taylor series through the coefficients f and g. In this study, the orbit equation in a perifocal system is solved using the Taylor series, which is based on time changing. A program in matlab is designed to apply the results for a geocentric satellite in low orbit (height from perigee, hp= 622 km). The input parameters were the initial distance from perigee, the initial time, eccentricity, true anomaly, position, and finally the velocity. The output parameters were the final distance from perigee and the final time values. The results of radial distance as opposed to time were plotted for dissimilar times in seconds and their comparison with the exact solution, with the aim of selecting an optimized reference orbit at a height of 622 km. The results indicated that the two series diverged excessively as the time increased from the exact solution, excluding the time of 850 sec. The f and g series had a little shift. Besides, the root mean square error (rmse) is computed for 750 sec. It was about 5 for the two series before diverging at about 180 sec and rapidly growing with time. For 850 sec, the (rmse) is approaching 10 for the two series and increasing quickly over time. So, the (rmse) is directly proportional to time, which means that as time increases, the diverging behavior and the value of the (rmse) will also increase. If more terms (Δt) are used for the two series and more time is included, the two series will deviate from the exact solution. The program's results are compared to other published studies in this field; they demonstrated high convergence.

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Publication Date
Mon Apr 01 2019
Journal Name
Journal Of Engineering
Investigation of Optimum Heat Flux Profile Based on the Boiling Safety Factor
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An experimental study is conducted to investigate the effect of heat flux distribution on the boiling safety factor of its cooling channel. The water is allowed to flow in a horizontal circular pipe whose outlet surface is subjected to different heat flux profiles. Four types of heat flux distribution profiles are used during experiments: (constant distribution profile, type a, triangle distribution profile with its maximum in channel center, type b, triangle distribution profile with its maximum in the channel inlet, type c, and triangle distribution profile with its maximum in the channel outlet, type d). The study is conducted using heat sources of (1000 and 2665W), water flow rates of (5, 7 and 9 lit/min). The water

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Publication Date
Tue Jan 29 2019
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The Impact of Tax Laws and Decisions in Determining the Tax Base of the Results of the Financial Statements of Companies
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This research aims to measure the discrepancy between the accounting income which is prepared according to generally accepted accounting principles and the tax income that is being prepared according to the rules and tax laws, and find out the most important differences that arise between incomes.The research found the most important to the following conclusions:1.Faces determining the tax base for companies subject to income challenges related to the weakness of the efficiency and the possibility of technical angel tax and its ability to examine the financial statements submitted to the tax administration tax.2.That the tax system in Iraq does not comply with accepted accounting principles generally accepted.The research recommends the

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Publication Date
Sun Mar 01 2020
Journal Name
Journal Of Engineering
Effect of Dam Height on The Stability of Earth Dam (Case Study: Karolinka Dam)
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The Karolinka earth-fill dam was constructed between 1977 and 1984 on the Stanovnice river above the town of Karolinka in the region of Vsetínsko in Czech Republic. Because of leakage on the downstream dam face due to technological indiscipline when filling dam layers during the dam construction stage, there were some steps to improve state dam safety. The final rehabilitation is to construct the diaphragm walls from self-hardening cement-bentonite suspension along the length of the dam. In addition to connecting the gallery and abutment (2 × 25 m long) by using jet piles. The article presents numerical modeling of safety factor evaluation associated with the state of the dam body and foundation; before, and after seal

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Publication Date
Fri Mar 01 2019
Journal Name
Iraqi Journal Of Physics
The effect of rear earth doping CdS nanostructure on structural, optical and photoconductivity properties
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Rare earth elements (Cerium, Lanthanum and Neodymium) doped CdS thin films are prepared using the chemical Spray Pyrolysis Method with temperature 200 oC. The X-ray diffraction (XRD) analysis refers that pure CdS and CdS:Ce, CdS:La and CdS:Nd thin films showed the hexagonal crystalline phase. The crystallite size determined by the Debye-Scherrer equation and the range was (35.8– 23.76 nm), and it was confirmed by field emission scanning electron microscopy (FE-SEM). The pure and doped CdS shows a direct band gap (2.57 to 2.72 eV), which was obtained by transmittance. The room-temperature photoluminescence of pure and doped CdS shows large peak at 431 nm, and two small peaks at (530 and 610 nm). The Current – voltage measurement in da

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Publication Date
Fri May 01 2020
Journal Name
Environmental Technology & Innovation
Environmental remediation of synthetic leachate produced from sanitary landfills using low-cost composite sorbent
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Publication Date
Sat Feb 01 2020
Journal Name
Journal Of Economics And Administrative Sciences
Applying some hybrid models for modeling bivariate time series assuming different distributions for random error with a practical application
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Abstract

  Bivariate time series modeling and forecasting have become a promising field of applied studies in recent times. For this purpose, the Linear Autoregressive Moving Average with exogenous variable ARMAX model is the most widely used technique over the past few years in modeling and forecasting this type of data. The most important assumptions of this model are linearity and homogenous for random error variance of the appropriate model. In practice, these two assumptions are often violated, so the Generalized Autoregressive Conditional Heteroscedasticity (ARCH) and (GARCH) with exogenous varia

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Publication Date
Wed Sep 01 2021
Journal Name
Baghdad Science Journal
Optimum Median Filter Based on Crow Optimization Algorithm
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          A novel median filter based on crow optimization algorithms (OMF) is suggested to reduce the random salt and pepper noise and improve the quality of the RGB-colored and gray images. The fundamental idea of the approach is that first, the crow optimization algorithm detects noise pixels, and that replacing them with an optimum median value depending on a criterion of maximization fitness function. Finally, the standard measure peak signal-to-noise ratio (PSNR), Structural Similarity, absolute square error and mean square error have been used to test the performance of suggested filters (original and improved median filter) used to removed noise from images. It achieves the simulation based on MATLAB R2019b and the resul

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Publication Date
Sat Dec 20 2025
Journal Name
Al-nahrain Journal For Engineering Sciences
Optimum Height of Plate Stiffener under Pressure Effect
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The economical design of plate loaded by pressure can be obtained by using stiffeners instead of increasing the thickness of plate. The main subject of this work is to obtain the effect of stiffener height on the maximum stress in the plate subjected to pressure load. Different plate-stiffener sets are selected to find the effects of stiffener thickness, plate dimensions and pressure, on the optimum stiffener height. The models under consideration are square plates clamped rigidly from four edges. Finite Element method is used to analyze 160 different models by using the Finite Element software package ANSYS version 11. Another analysis method based on maximum stress equation is used to analyze 30 models. The graphical comparison of results

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Publication Date
Tue Jan 01 2019
Journal Name
Energy Procedia
The relationship of Nuclear Decay Methods (alpha and beta) Particles with the Nuclear Deformation for Nuclei inUranium-238 and Thorium -232 Series
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Publication Date
Mon Feb 25 2019
Journal Name
Iraqi Journal Of Physics
Determining the concentrations of radon and the rate of annual effective dose in some types of drinking water available in the Iraqi markets
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           In this research, radon concentrations in some types of healthy drinking water samples available in Iraq's market were measured using a technique called Durridge RAD-7-H2O with closed loop. Then the rate of annual effective dose in human taken this water is determined.

          It was found that, radon concentrations in studied samples ranged between 1.2 Bq.m-3 to 142 Bq.m-3. The results of the radon concentrations and the rate of annual effective dose for drinking water samples were significantly lower than the USEPA and WHO recommended limits that equal 500 Bq/m3 and 1 mSv/y resp

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