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jeasiq-1344
Comparison of Multistage and Numerical Discretization Methods for Estimating Parameters in Nonlinear Linear Ordinary Differential Equations Models.
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Many of the dynamic processes in different sciences are described by models of differential equations. These models explain the change in the behavior of the studied process over time by linking the behavior of the process under study with its derivatives. These models often contain constant and time-varying parameters that vary according to the nature of the process under study in this We will estimate the constant and time-varying parameters in a sequential method in several stages. In the first stage, the state variables and their derivatives are estimated in the method of penalized splines(p- splines) . In the second stage we use pseudo lest square to estimate constant parameters, For the third stage, the remaining constant parameters and time-varying parameters are estimated by using a semi-parametric regression model and then comparing this method with methods based on numerical discretization methods, which includes two stages. In the first stage we estimate the state variables and their derivatives by (p spline) , In the second stage we use Methods of numerical discretization methods (the Euler discretization method  and the trapezoidal discretization method), where the comparison was done using simulations and showed the results superior to the trapezoidal method of numerical differentiation where it gave the best estimations to balance between accuracy in estimation And high arithmetic cost.

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Publication Date
Wed Jun 30 2004
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Studying the Factors Effects on the Flowability of ZnO-CuO/γAl2O3 Catalyst Through Hopper Before Tableting Process
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Publication Date
Sun Mar 01 2026
Journal Name
Case Studies In Thermal Engineering
Dynamic thermal modelling of energy storage unit based on PCM under single or two-phase flow conditions
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Phase change materials are extensively studied for use in low-, mid-, and high-temperature applications due to their melting and solidification temperatures, latent heat, and thermophysical properties. This work aims to explore the energy stored, or released and their duration for the energy storage unit formed of a phase change material surrounding a tube within which a hot or cold, single or Two-Phase fluid flows, serving as a heat source or sink. The 3D axial transient thermal analysis of the energy storage unit is performed using the finite element method via a MATLAB-developed computer program. The effects of single- or Two-Phase fluid flow on temperature distribution, solidification, melting duration, and energy stored within phase ch

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Publication Date
Thu Jan 01 2009
Journal Name
Ibn Al- Haitham J. Fo R Pure & Appl. Sci
Multiple Mixing Ratios of Gamma Rays Erγ)nEr(n, From 168 168 Reaction  Using a2 – Ratio Method
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The -mixing of  - transition in Er 168 populated in Er)n,n(Er 168168  reaction is calculated in the present work by using a2- ratio method. This method has used in previou studies [4, 5, 6, 7] in case that the second transition is pure or for that transition which can be considered as pure only, but in one work we applied this method for two cases, in the first one for pure transition and in the 2nd one for non pure transitions. We take into accunt the experimental a2- coefficient for p revious works and -values for one transition only [1]. The results obtained are, in general, in agood agreement within associated errors, with those reported previously [1], the discrepancies that occur are due to inaccuracies existing

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Publication Date
Fri Mar 31 2017
Journal Name
Journal Of Engineering
Cultivation of Chlorella Vulgaris Using Airlift Photobioreactor Sparged with 5%CO 2 -Air as a Biofixing Process
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The present paper addresses cultivation of Chlorella vulgaris microalgae using airlift photobioreactor that sparged with 5% CO 2 /air. The experimental data were compared with that obtained from bioreactor aerated with air and unsparged bioreactor. The results showed that the concentration of biomass is 0.36 g l -1  in sparged bioreactor with CO2/air, while, the concentration of biomass reached to 0.069 g l -1  in the unsparged bioreactor. They showed also that aerated  ioreactor.with CO2/air gives more biomass production even the bioreactor was aerated with air. This study proved that application of sparging system for  ultivation of Chlorella vulgaris microalgae using either CO2/air mixture or air has a significant

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Publication Date
Wed Jul 11 2018
Journal Name
دراسات تربوية
Understanding the nature of the scientific endeavor among chemistry teachers according to the Educational Reform Project 2061
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Publication Date
Sun Jun 26 2022
Journal Name
Electrical Engineering
Optimal insulation design of form-wound stator winding with stress grading system under fast rise-time excitation
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The effective insulation design of the stress grading (SG) system in form-wound stator coils is essential for preventing partial discharges and excessive heat generation under pulse-width modulation excitation. This paper proposes a method to find the optimal insulation design of the SG system aimed at reducing the dielectric and thermal stresses in the machine coil. The non-uniform transmission line model is used to predict the voltage propagation along the overhang, SG, and slot regions considering the variation in the physical properties of the insulation layers. The machine coil parameters for different insulation materials are calculated by using the finite element method. Two optimization algorithms, fmincon and particle swarm optimiz

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Publication Date
Thu Jan 17 2019
Journal Name
Biochemichal And Cellular Archives
A FIRST RECORD OF EOBANIA VERMICULATA (O. F. MÜLLER, 1774), TERRESTRIAL SNAIL (GASTROPODA-HELICIDAE) FROM BAGHDAD, IRAQ
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: The terrestrial snail Eobania vermiculata (O. F. Müller, 1774) were collected from three station in Baghdad Al- Karkh, Iraq between the period from June 2016 to July 2017. Then we studied the life cycle from the egg to maturity. We studied and photographed the external morphology of it’s shell to identified the species. This species was recorded for the first time in Baghdad.

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Publication Date
Mon Jun 20 2022
Journal Name
Bulletin Of The Iraq Natural History Museum (p-issn: 1017-8678 , E-issn: 2311-9799)
CONCHOLOGICAL VARIABILITY OF TERRESTRIAL MOLLUSK CHONDRULOPSINA FEDTSCHENKOI (ANCEY, 1886) (GASTROPODA, PULMONATA, ENIDAE) FROM THE ZARAFSHAN RANGE, UZBEKISTAN
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The article presents the results of studying the conchological variability of the terrestrial mollusk Chondrulopsina fedtschenkoi (Ancey, 1886), known to occur in three regions of the Zaravshan Range (Central Asia): the Urgutsay Gorge, the vicinity of the Gissarak Reservoir and the Ingichka-Irmak Gorge. Conchological variability was determined based on statistical analysis. The climate of the three regions is different, and environmental factors have led to changes in the mollusk shell. The shells have changed in response to environmental factors, these are their adaptive traits for survival; the variability of conchological features is also reflected in the color of the shell, and the intensive development of the color of the shell in m

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Publication Date
Sun Mar 01 2009
Journal Name
Baghdad Science Journal
MORPHOLOGICAL STUDIES ON THE EFFECT OFNIGELLA SATIVA SEEDS ON THE MAMMARY GLAND OF MATURE MALE NORWAY RAT
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Nigella sativa seeds (NSS) are reputed traditionally and scientifically as a potent agent that promote milk secretion (galactagogue), but their mechanism of action is studied trivially. One suggestion was that these seeds are bio-transformed to sex hormones within the ovaries. Therefore, this investigation was designated to throw light on the action of these seeds in the absence of ovaries i.e. in male rats. Thirty Norway male albino rats were used in this investigation. They were divided into experimental (n=20,fed NSS 2g/ Kg body weight /day for 14 days) and control (n=10, fed placebo for 14 days). After sacrifice mammary gland and blood samples were obtained. Experimental rats revealed a significant increase (p (0.01>in

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Publication Date
Fri Mar 25 2022
Journal Name
Asian Journal Of Biochemistry, Genetics And Molecular Biology
Evaluation of the Simple Sequence Repeats to Work as a Phase Variation with the Neisseria meningitidis Genome
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Background: The most crucial mechanism of genetic variation in N. meningitidis is the slipped strand mispairing, this mechanism generates Phase variation using simple sequence repeat (SSR) and is commonly used by the N. meningitidis to escape the immune system despite its function in eradicating the pathogenic and commensal bacteria. Some of simple sequence repeats (SSRs) that located within the genome works as phase variation while other SSRs have no role in generating phase variation mechanisms. Therefore, Aim: the main goal of the current in silico study was to detect the probability of SSR to enroll with phase variation for the entire N. meningitidis genome. Methods: Different criteria were used to judge SSR as

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