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ijs-9590
Day to Day variation of Ionosphere Electron and Ion Temperature during Great and Severe Geomagnetic Storms
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The ionospheric characteristics exhibit significant variations with the solar cycle, geomagnetic conditions, seasons, latitudes and even local time. Representation of this research focused on global distribution of electron (Te) and ion temperatures (Ti) during great and severe geomagnetic storms (GMS), their daily and seasonally variation for years (2001-2013), variations of electron and ion temperature during GMS with plasma velocity and geographic latitudes. Finally comparison between observed and predicted Te and Ti get from IRI model during the two kinds of storm selected. Data from satellite Defense Meteorological Satellite Program (DMSP) 850 km altitude are taken for Te, Ti and plasma velocity for different latitudes during great and severe geomagnetic storms from years 2001 to 2013 according to what is available appeared that there is 22 events for severe and great geomagnetic storms happened during years 2001-2005 only from years selected, from maximum solar cycle 23. From data analysis, in general the temperature of the electron is greater than the temperature of the ion, but there are some disturbances happened during the storm time, in the day there is fluctuation in values of Te and Ti with the value of Ti greater than Te. Through the Dst index, Te and Ti do not depend on the strength of the geomagnetic storm. Plasma velocity variation shows the same profile of Te and Ti variation during the storm time and there is a linear relation between (Te) & (Ti) and plasma velocity. The variation of electron and ion temperature with geographic latitude during severe and great storms appears that as the latitude increases the temperature of ions increases reaches its maximum value approximately 80000K at poles.
From comparing the predicted Te and Ti values calculating from IRI model during the great and severe storms with observed values, it’s found that the predicted values from IRI model much less than the observed values and the variation was nonlinear along 24 hours, from this we can conclude that the model must be corrected for Te and Ti for these two kinds of storms.

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Publication Date
Thu Feb 15 2024
Journal Name
Journal Of Al-turath University College
A Comparison of Traditional and Optimized Multiple Grey Regression Models with Water Data Application
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Grey system theory is a multidisciplinary scientific approach, which deals with systems that have partially unknown information (small sample and uncertain information). Grey modeling as an important component of such theory gives successful results with limited amount of data. Grey Models are divided into two types; univariate and multivariate grey models. The univariate grey model with one order derivative equation GM (1,1) is the base stone of the theory, it is considered the time series prediction model but it doesn’t take the relative factors in account. The traditional multivariate grey models GM(1,M) takes those factor in account but it has a complex structure and some defects in " modeling mechanism", "parameter estimation "and "m

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Publication Date
Sat Dec 31 2022
Journal Name
Journal Of Economics And Administrative Sciences
Using Some Estimation Methods for Mixed-Random Panel Data Regression Models with Serially Correlated Errors with Application
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This research includes the study of dual data models with mixed random parameters, which contain two types of parameters, the first is random and the other is fixed. For the random parameter, it is obtained as a result of differences in the marginal tendencies of the cross sections, and for the fixed parameter, it is obtained as a result of differences in fixed limits, and random errors for each section. Accidental bearing the characteristic of heterogeneity of variance in addition to the presence of serial correlation of the first degree, and the main objective in this research is the use of efficient methods commensurate with the paired data in the case of small samples, and to achieve this goal, the feasible general least squa

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Publication Date
Mon Jun 01 2015
Journal Name
Journal Of Engineering
Unity Sliding Mode Controller Design for Active Magnetic Bearings System
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Active Magnetic Bearings (AMBs) are progressively being implemented in a wide variety of applications. Their exclusive appealing features make them suitable for solving traditional rotor-bearing problems using novel design approaches for rotating machinery.  In this paper, a linearized uncertain model of AMBs is utilized to develop a nonlinear sliding mode controller based on Lyapunov function for the electromechanical system. The controller requires measurements of the rotor displacements and their derivatives. Since the control law is discontinuous, the proposed controller can achieve a finite time regulation but with the drawback of the chattering problem. To reduce the effect of this problem, the gain of the uni

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Publication Date
Mon Sep 20 2021
Journal Name
Key Engineering Materials
Effect of Partial Substitution of Sr by Ba on the Structural Properties of Tl<sub>0.8</sub>Ni<sub>0.2</sub>Sr<sub>2-x</sub>Br<sub>x</sub>Ca<sub>2</sub>Cu<sub>3</sub>O<sub>9-δ</sub> System
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In this manuscript, the effect of substituting strontium with barium on the structural properties of Tl0.8Ni0.2Sr2-xBrxCa2Cu3O9-δcompound with x= 0, 0.2, 0.4, have been studied. Samples were prepared using solid state reaction technique, suitable oxides alternatives of Pb2O3, CaO, BaO and CuO with 99.99% purity as raw materials and then mixed. They were prepared in the form of discs with a diameter of 1.5 cm and a thickness of (0.2-0.3) cm under pressures 7 tons / cm2, and the samples were sintered at a constant temperature o

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Publication Date
Tue Oct 25 2022
Journal Name
Aip Conference Proceedings
The structural properties of mawsoniteCu6Fe2 S8Sn[CFTS] thin films effected by violet laser irradiation deposited via semi-computerized spray pyrolysis technique
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Publication Date
Mon Mar 07 2022
Journal Name
Journal Of Educational And Psychological Researches
The Impact of Cognitive Behavior Program Based on Meichenbaum Theory in Reducing the Negative Emotional Sensitivity among the Intermediate Stage Students
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The aim of this research is to construct a cognitive behavior program based on the theory of Meichenbaum in reducing the emotional sensitivity among Intermediate school students. To achieve the aims of the research, two hypotheses were formulated and the experimental design with equal groups was chosen. The population of research and its sample are determined. The test of negative emotional sensitivity, which is constructed by the researcher, was adopted. The test contains (20) items proved validity and reliability as a reliable test by presenting it to a group of arbitrators and experts in education and psychology. An educational program is constructed based on the theory of Meichenbaum. The test was applied to a sample of (60) second i

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Publication Date
Sat Sep 30 2023
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The role of the tax examiner's procedures in increasing or decreasing tax revenue : Applied research in the General Authority for Taxes
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Abstract:

               The tax is one of the elements of the general revenues of the state and contributes to covering its expenses. Taxes are imposed in most countries of the world. The tax proceeds depend on a set of factors that contribute either positively or negatively to the tax share by increasing or decreasing it. Therefore, the research aims to demonstrate the role of the tax examiner's procedures in achieving the validity of the taxable base and its reflection on the tax proceeds, as well as reviewing the tax examiner's procedures related to the tax return process. Examination and tax audit of the financial statements, as well as presenting the financial statements to an independent and i

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Publication Date
Sat Dec 31 2022
Journal Name
International Journal Of Dentistry
Bond Strength Survival of a Novel Calcium Phosphate-Enriched Orthodontic Self-Etching System after Various Ageing Protocols: An In Vitro Study
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Objective. This study aimed to evaluate the orthodontic bond strength and enamel-preserving ability of a hydroxyapatite nanoparticles-containingself-etch system following exposure to various ageing methods. Materials and Methods. Hydroxyapatite nanoparticles (nHAp) were incorporated into an orthodontic self-etch primer (SEP, Transbond™ plus) in three different concentrations (5%, 7%, and 9% wt) and tested versus the plain SEP (control) for shear bond strength (SBS), adhesive remnant index (ARI) scores, and enamel damage in range-finding experiments using premolar teeth. The best-performing formulation was further exposed to the following four artificial ageing methods: initial debonding, 24 h water storage, one-month water stora

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Publication Date
Sun Mar 01 2020
Journal Name
Baghdad Science Journal
Evaluation of Sex Hormone Levels in Benign Prostatic Hyperplasia Patients Treated with 5 Alpha-Reductase Inhibitor (Finasteride) in Amara city/Iraq
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The present study aimed to determine the serum sex hormone levels among Benign Prostatic Hyperplasia (BPH) patients before and after 3 months of oral administration of 5-α reductase inhibitor(finasteride). Forty BPH patients and 40 healthy men from Amara city were involved in this study, their ages were between 40-59 year. They were all subjected  to direct estimation of hormones by MinVidas method including Testosterone (T), Estradiol (E2), Follicle Stimulating Hormone (FSH), Luteinizing Hormone (LH), Prolactin (PRL), and Dihydrotestosterone (DHT) before and after 3 months of treatment with 5α-reductase inhibitor (finasteride) (the healthy individuals didn’t take finasteride).The results showed that T level was significantly lo

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Publication Date
Thu Mar 31 2022
Journal Name
Iraqi Geological Journal
Geological Model of the Khabour Reservoir for Studying the Gas Condensate Blockage Effect on Gas Production, Akkas Gas Field, Western Iraq
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The Khabour reservoir, Ordovician, Lower Paleozoic, Akkas gas field which is considered one of the main sandstone reservoirs in the west of Iraq. Researchers face difficulties in recognizing sandstone reservoirs since they are virtually always tight and heterogeneous. This paper is associated with the geological modeling of a gas-bearing reservoir that containing condensate appears while production when bottom hole pressure declines below the dew point. By defining the lithology and evaluating the petrophysical parameters of this complicated reservoir, a geological model for the reservoir is being built by using CMG BUILDER software (GEM tool) to create a static model. The petrophysical properties of a reservoir were computed using

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