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
Mon Jun 01 2015
Journal Name
Journal Of Economics And Administrative Sciences
Analysis of Robust Principal Components Depends on the some methods of Projection-Pursuit
...Show More Authors

The analysis of the classic principal components are sensitive to the outliers where they are calculated from the characteristic values and characteristic vectors of correlation matrix or variance Non-Robust, which yields an incorrect results in the case of these data contains the outliers values. In order to treat this problem, we resort to use the robust methods where there are many robust methods Will be touched to some of them.

   The robust measurement estimators include the measurement of direct robust estimators for characteristic values by using characteristic vectors without relying on robust estimators for the   variance and covariance matrices. Also the analysis of the princ

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Oct 22 2013
Journal Name
Chinese Journal Of Engineering
Studying the Effect of Some Surfactants on Drag Reduction of Crude Oil Flow
...Show More Authors

The influence of SDBS, SLS, SLES, and SS as drag reducing agents on flow of Iraqi crude oil in pipelines was investigated in the present work. The effect of additive type, additive concentration, pipe diameter, solution flow rate, and the presence of elbows on the percentage of drag reduction (%Dr) and the amount of flow increases (%FI) was addressed. The maximum drag reduction was 55% obtained at 250 ppm SDBS surfactant flowing in straight pipes of 0.0508 m I.D. The dimensional analysis was used for grouping the significant quantities into dimensionless groups to reduce the number of variables. The results showed good agreement between the observed drag reduction percent values and the predicted ones with high value of the co

... Show More
View Publication
Scopus (24)
Crossref (18)
Scopus Crossref
Publication Date
Wed Mar 01 2017
Journal Name
Bioprocess Engineering
Studying the Effect of Eco-addition Inhibitors on Corrosion Resistance of Reinforced Concrete
...Show More Authors

Publication Date
Tue Jun 01 2010
Journal Name
Al-khwarizmi Engineering Journal
'Influence of Draft Tube Diameter on Operation Behavior of Air Lift Loop Reactors
...Show More Authors

The ratio of draft tube to reactor diameters is of decisive importance for the operation behavior of air lift loop reactors. The influence of draft tube geometry was investigated with respect to oxygen mass transfer and mixing time. The diameter ratio was varied between 0.33 and 0.80. The measurements were performed in two loop reactors with liquid capacities of 11.775 and 26.49 liters using aqueous with solutions of different coalescence behavior. The results show that there is no single diameter ratio which would produce most favorable conditions for the two process parameters. With respect to the more important requirements of aerobic cultures, i.e high oxygen mass transfer and efficient mixing, a diameter ratio between 0.5 and 0.6 is

... Show More
View Publication Preview PDF
Publication Date
Mon May 22 2023
Journal Name
Journal Of Optics
The influence of gold nanoparticles on electro-optical properties of nematic liquid crystal
...Show More Authors

View Publication
Scopus (4)
Crossref (4)
Scopus Clarivate Crossref
Publication Date
Sun Mar 01 2015
Journal Name
Journal Of Engineering
Effect of Initial Water Content on the Properties of Compacted Expansive Unsaturated Soil
...Show More Authors

Unsaturated soil can raise many geotechnical problems upon wetting and drying resulting in swelling upon wetting and collapsing (shrinkage) in drying and changing in the soil shear strength. The classical principles of saturated soil are often not suitable in explaining these phenomena. In this study, expansive  soil (bentonite and sand) were tested in different water contents and dry unit weight chosen from the compaction curve to examine the effect of water content change on soil properties (swelling pressure, expansion index, shear strength (soil cohesion) and soil suction by the filter paper method). The physical properties of these soils were studied by conducting series of tests in laboratory. Fitting methods

... Show More
View Publication Preview PDF
Publication Date
Tue Feb 12 2019
Journal Name
Iraqi Journal Of Physics
Effect of industrial powder on mechanical properties of glass fiber reinforced epoxy composite
...Show More Authors

In the present study, composites were prepared by Hand lay-up molding and investigated. The composites constituents were epoxy resin as the matrix, 6% volume fractions of Glass Fibers (G.F) as reinforcement and 3%, 6% of industrial powder (Calcium Carbonate CaCO3, Potassium Carbonate K2CO3 and Sodium Carbonate Na2CO3) as filler. Density, water absorption, hardness test, flexural strength, shear stress measurements and tests were conducted to reveal their values for each type of composite material. The results showed that the non – reinforced epoxy have lower properties than composites material. Measured density results had show an incremental increase with volume fraction increase

... Show More
View Publication Preview PDF
Crossref (2)
Crossref
Publication Date
Mon Feb 01 2016
Journal Name
Journal Of Engineering
Valuation of Construction Projects Based on of Quantity Scale by using Expert System
...Show More Authors

The subject of an valuation of quality of construction projects is one of the topics which it becomes necessary of the absence of the quantity standards in measuring the control works and the quality valuation standards in constructional projects. In the time being it depends on the experience of the workers which leads to an apparent differences in the valuation.

The idea of this research came to put the standards to evaluate the quality of the projects in a special system depending on quantity scale nor quality specifying in order to prepare an expert system “ Crystal “ to apply this special system to able the engineers to valuate the quality of their projects easily and in more accurate ways.

View Publication Preview PDF
Publication Date
Wed Jun 24 2026
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Effect of Temperature and Frequency on the Dielectric Properties of PVC/MnCl2 Composite
...Show More Authors

View Publication
Publication Date
Mon Dec 03 2018
Journal Name
Journal Of Engineering
Studying the Effects of Different Polymers on Rheological Properties of Water Base Muds
...Show More Authors

This research is focusing on finding more effective polymers that leads to enhance the rheological properties of Water Base Muds. The experiments are done for different types of mud for all substances which are Polyacrylamide, Xanthan gum, CMC (Carboxyl Methyl Cellulose). This study shows the effect of add polymer to red bentonite mud, effect of add polymer to Iraqi bentonite mud, the effect of add bentonite to polymer mud. The mud properties of Iraqi bentonite blank are enhanced after adding the polymers to the blank mix, CMC gives the highest value of plastic viscosity and Gel strength than others; X-anthan gives the highest value of yield point and gel strength than others. For the red bentonite mud, Polyacrylamide has the highes

... Show More
View Publication
Crossref (1)
Crossref