Preferred Language
Articles
/
HxfSVI8BVTCNdQwCAG0Y
Simulation on Rotation Curve of Spiral Galaxies
...Show More Authors
Abstract<p>The problem of dark matter in galaxies is still one of the most important unsolved problems in the contemporary extragalactic astronomy and cosmology. The existence of a significant dynamic difference between the visible mass and the conventional mass of galaxies firmly establishes observational result. In this paper an unconventional explanation will be tested as an alternative to the cold dark matter hypothesis; which is called the modified Newtonian dynamics (MOND).</p><p>In this paper covers the simulation of galactic evolutions; where the two hypotheses are tested via the rotation curves. N-body simulation was carried adopting different configuration like a hot disk, elliptical (with arms and without arms) with a different parameter that covers the objects distribution, masses and velocities. It is shown from the simulation results that the MOND hypothesis has generated better rotation curves than the Newtonian theorem. Moreover, the appropriate configuration and parameters for spiral galaxy are investigated. It is shown that this assignment has not been easy; because the problem is very delicate and unstable.</p>
Scopus Clarivate Crossref
View Publication
Publication Date
Wed Nov 01 2017
Journal Name
Journal Of Economics And Administrative Sciences
strong criminal capabilities، Using simulation .
...Show More Authors

The penalized least square method is a popular method to deal with high dimensional data ,where  the number of explanatory variables is large than the sample size . The properties of  penalized least square method are given high prediction accuracy and making estimation and variables selection

 At once. The penalized least square method gives a sparse model ,that meaning a model with small variables so that can be interpreted easily .The penalized least square is not robust ,that means very sensitive to the presence of outlying observation , to deal with this problem, we can used a robust loss function to get the robust penalized least square method ,and get robust penalized estimator and

... Show More
View Publication Preview PDF
Crossref
Publication Date
Fri Jul 25 2025
Journal Name
Journal Of Baghdad College Of Dentistry
Assessment of the relationship between maxillary sinus floor and maxillary posterior teeth root apices using spiral CT scan
...Show More Authors

Background: The purpose of this study is to investigate the relationship between the roots of the maxillary posterior teeth and the maxillary sinus using spiral computed tomography, and measured the distances between the roots of the maxillary posterior teeth and the sinus floor. Materials and Methods: The sample of the present study was a total of 120 Iraqi subject (60 males & 60 females) aged (20-60) years old, who admitted to spiral Computed Tomography scan unit in AL-Zahraa hospital in AL-Kut city to have Computed Tomography scan of the brain and paranasal sinuses who had complaints of headaches or with suspicion of sinusitis but without pathological findings in maxillary sinuses. From November 2012 to April 2013, CT sagittal reconstruc

... Show More
View Publication Preview PDF
Publication Date
Fri Jul 25 2025
Journal Name
Journal Of Baghdad College Of Dentistry
Accuracy of spiral computed tomography in evaluation of maxillary sinus septa among dentate and edentulous Iraqi subjects (Comparative study)
...Show More Authors

Background: Presence of maxillary sinus septa has been known to be a complicating factor for sinus elevation procedure and implant placement in posterior maxilla. The maxillary sinuses septa are thin walls of cortical bone inside the sinus. They vary in number, location, and height. This study aimed to discover the accuracy of Spiral Computed Tomographic Scan in evaluation the maxillary sinus septa (prevalence, location, height) in subjects with dentate, partially edentulous and completely edentulous maxilla. Material and method: This study included (267) subjects ranged from (20-70 years), (132) male and (135) female divided into three groups, (97) fully dentate group, (102) partially edentulous group and (68) completely edentulous group w

... Show More
View Publication Preview PDF
Publication Date
Fri Jun 30 2006
Journal Name
Al-kindy College Medical Journal
The Use of Spiral Computerized Tomography in the Diagnosis of Middle –Third Facial Fractures as Compared to Plain Radiography
...Show More Authors

Background: Trauma is one of the most common
clinical problems that confront the maxillofacial
surgeon and radiologist alike. Middle third facial
fractures are diagnosed primarily on the bases of
clinical examination and plain radiographs than can
result in much preoperative speculation.
Objective: To assess the advantages of spiral
computerized tomography over conventional
radiography in the pre-surgical evaluation of middle
third facial fractures.
Methods: Thirty patients with thirty-eight facial
fractures were studied, all patients were examined
clinically, by plain radiography and then by spiral CT.
Results: Of the 38 middle-third fractures, 16
(42.1%) were zygomatic fractures, 8 (21.1%) were

... Show More
View Publication Preview PDF
Publication Date
Sat Mar 30 2013
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Simulation of Cathodic Protection System Using Matlab
...Show More Authors

Iraq has a huge network of pipelines, transport crude oil and final hydrocarbon products as well as portable water. These networks are exposed to extensive damage due to the underground corrosion processes unless suitable protection techniques are used. In this paper we collect the information of cathodic protection for pipeline in practical fields (Oil Group in Al Doura), to obtain data base to understand and optimize the design which is made by simulation for the environmental factors and cathodic protection variables also soil resistivity using wenner four terminal methods for survey sites; and soil pH investigations were recorded for these selected fields were within 7-8, and recording the anodes voltage and its related currents for

... Show More
View Publication Preview PDF
Publication Date
Sat Jan 01 2022
Journal Name
Journal Of Engineering
CFD Simulation Model of Salt Wedge Propagation
...Show More Authors

This study aims to numerically simulate the flow of the salt wedge by using computational fluid dynamics, CFD. The accuracy of the numerical simulation model was assessed against published laboratory data. Twelve CFD model runs were conducted under the same laboratory conditions. The results showed that the propagation of the salt wedge is inversely proportional to the applied freshwater discharge and the bed slope of the flume.  The maximum propagation is obtained at the lowest discharge value and the minimum slope of the flume. The comparison between the published laboratory results and numerical simulation shows a good agreement. The range of the relative error varies between 0 and 16% with an average of 2% and a roo

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Sun Dec 01 2019
Journal Name
Baghdad Science Journal
Comparison of Some Suggested Estimators Based on Differencing Technique in the Partial Linear Model Using Simulation
...Show More Authors

In this paper new methods were presented based on technique of differences which is the difference- based modified jackknifed generalized ridge regression estimator(DMJGR) and difference-based generalized  jackknifed ridge regression estimator(DGJR), in estimating the parameters of linear part of the partially linear model. As for the nonlinear part represented by the nonparametric function, it was estimated using Nadaraya Watson smoother. The partially linear model was compared using these proposed methods with other estimators based on differencing technique through the MSE comparison criterion in simulation study.

View Publication Preview PDF
Crossref (1)
Scopus Clarivate Crossref
Publication Date
Mon Mar 01 2021
Journal Name
Iraqi Journal Of Physics
Studying the Correlation Between Supermassive Black Holes and Star Formation Rate for Samples of Seyfert Galaxies (Type 1 and 2)
...Show More Authors

An optical spectroscopic study is reported in this article to study the correlation between the supermassive black hole (SMBH) and the star formation rate (SFR) for a sample of Seyfert galaxies type (I and II). The study focused on 45 galaxy of Seyfert 1, in addition to 45 galaxy of Seyfert 2, where these samples have been selected form different survey of Salon Digital Sky Survey (SDSS). The redshift (z) of these objects were between (0.02 – 0.26). The results of Seyfert 1 galaxies shows that there good correlation between the SMBH and the SFR depending on statistical analysis parameter named Spearman’s Rank Correlation in a factor of (ρ=0.609), as well as the Seyfert 2 galaxies results show a good correlation between the SMBH

... Show More
Crossref
Publication Date
Mon Mar 01 2021
Journal Name
Iraqi Journal Of Physics
Studying the Correlation Between Supermassive Black Holes and Star Formation Rate for Samples of Seyfert Galaxies (Type 1 and 2)
...Show More Authors

An optical spectroscopic study is reported in this article to study the correlation between the supermassive black hole (SMBH) and the star formation rate (SFR) for a sample of Seyfert galaxies type (I and II). The study focused on 45 galaxy of Seyfert 1, in addition to 45 galaxy of Seyfert 2, where these samples have been selected form different survey of Salon Digital Sky Survey (SDSS). The redshift (z) of these objects were between (0.02 – 0.26). The results of Seyfert 1 galaxies shows that there good correlation between the SMBH and the SFR depending on statistical analysis parameter named Spearman’s Rank Correlation in a factor of (ρ=0.609), as well as the Seyfert 2 galaxies results show a good correlation between the SMBH and

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Apr 01 2021
Journal Name
Journal Of Engineering Science And Technologythis Link Is Disabled
Cfd simulation for the operation effect of gates openings of al-hay regulator on the local erosion
...Show More Authors

Scopus (6)
Scopus