Preferred Language
Articles
/
jmracpc-248
AN EXPERIMENTAL STUDY OF THE EFFECT OF VORTEX GENERATOR ON THE FLAT-PLATE BOUNDARY LAYER: AN EXPERIMENTAL STUDY OF THE EFFECT OF VORTEX GENERATOR ON THE FLAT-PLATE BOUNDARY LAYER
...Show More Authors

This paper is dealing with an experimental study to show the influence of the geometric characteristics of the vortex generators VG son the thickness of the boundary layer (∂) and drag coefficients (CD) of the flat plate. Vortex generators work effectively on medium and high angles of attack, since they are "hidden" under the boundary layer and practically ineffective at low angles.

            The height of VGs relative to the thickness of the boundary layer enables us to study the efficacy of VGs in delaying boundary layer separation. The distance between two VGs also has an effect on the boundary layer if we take into account the interference between two pairs of VGs. The effect of the changing in (h- the height of vortex generator, d- the average distance between tow vortex generators) on the thickness of the flat plate boundary layer and the drag coefficients has been studied for triangular vortex generator. The measurements of the vortex generator have been changed to determine the optimum boundary layer thickness and the change in drag coefficients. An experiment was done at an average free stream velocity, (U∞,) of 28 m/s. The experiment was conducted in the wind tunnel UTAD-2 University (NAU) Kiev, Ukraine.

View Publication Preview PDF
Quick Preview PDF
Publication Date
Tue May 16 2023
Journal Name
Political Sciences Journal
The Impact of Putinism on the Russian-Ukrainian Conflict: an analysis of the contents of the speeches of Russian President Vladimir Putin on the causes of the Russian war on Ukraine in 2022
...Show More Authors

this research seeks to shed light on the study of the impact of Putinism on the Russian-Ukrainian war that broke out in early 2022, by studying the contents of the speeches of Russian President Vladimir Putin before the start of the war. This research uses the structural approach in analyzing the components of the Russian political regime. The research tools used in this research include case studies, content analysis of Russian speeches, and personal meetings of researchers and specialists in Russian affairs. It sums up a number of important conclusions, most notably are : 1) Putinism is a totalitarian regime that includes the political doctrine during the era of Russian President Vladimir Putin. 2) Duginism represents the totality of t

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Jan 01 2018
Journal Name
Aip Conference Proceedings
Study the effect of nano SiO2 on dielectric strength property of zirconia
...Show More Authors

View Publication
Crossref (2)
Crossref
Publication Date
Mon Jan 01 2018
Journal Name
Aip Conference Proceedings
Study the effect of nano SiO2 on dielectric strength property of zirconia
...Show More Authors

View Publication
Scopus (3)
Crossref (2)
Scopus Clarivate Crossref
Publication Date
Sat Jan 05 2019
Journal Name
Iraqi Journal Of Physics
Study the effect of CaCO3 nanoparticles on physical properties of biopolymer blend
...Show More Authors

Chitosan (CH) / Poly (1-vinylpyrrolidone-co-vinyl acetate) (PVP-co-VAc) blend (1:1) and nanocomposites reinforced with CaCO3 nanoparticles were prepared by solution casting method. FTIR analysis, tensile strength, Elongation, Young modulus, Thermal conductivity, water absorption and Antibacterial properties were studied for blend and nanocomposites. The tensile results show that the tensile strength and Young’s modulus of the nanocomposites were enhanced compared with polymer blend [CH/(PVP-co-VAc)] film. The mechanical properties of the polymer blend were improved by the addition of CaCO3 with significant increases in Young’s modulus (from 1787 MPa to ~7238 MPa) and tensile strength (from 47.87 MPa to 79.75 MPa). Strong interfacial

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Mar 08 2021
Journal Name
Baghdad Science Journal
Theoretical Study of The Heating Effect of Laser Radiations on SiUcaGlass Systems
...Show More Authors

A theoretical study has been proposed to investigate the effects of different laser radiations (Nd - glass, DF and C02) as a heating source on different glass samples (Optical glass, Bk - 7 and Soda - lime glass) and different waves lengths (10.6, 3.8, 1.6) ???. The heat changes as which are resulted due irradiation with laser sources have been determined by using the one dimension mathematical relation as a function of time (t) and depth (z). The results of the study show ed that the irradiation with C02 laser had a greater effect than DF laser, while the effects of Nd - glass laser were minimal with a power density of (1.8*10?? w/m2) within atime(l^sec).(Forboth Kinds) The change in the temperatures were not exceeded than (70"K) in all sa

... Show More
View Publication Preview PDF
Publication Date
Sat Jun 01 2013
Journal Name
Journal Of Economics And Administrative Sciences
A field study of the problems of queues at some checkpoints in the city of Baghdad
...Show More Authors

 

Abstract

Due to the momentum of winning in the streets of the city of Baghdad as a result of the large number of checkpoints so felt researcher to conduct a field visit to find out the main reasons that led to this congestion and to find practical solutions to mitigate wastage winning the arrival time citizen to where you want the least possible time.

This research aims to overcome the difficulties experienced by citizens to reach their places of work and reduce waste at the time of service and waiting time as well as reduce the cost of waiting.

Has emerged study a set of conclusions, including the use of model queue (G / G / C) and the mome

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Aug 01 2017
Journal Name
Journal Of Economics And Administrative Sciences
Post a reflection on the capabilities of personnel programs A prospective study of a sample of the views of the staff at the Ministry of Higher Education and Scientific Research
...Show More Authors

            This research aims to know the role and impact of participation in the capabilities of human resources programs, and for the purpose of measuring it has been determined the dimensions of these two variables by relying on standards for this purpose, was chosen as the Ministry of Higher Education and Scientific Research / device supervision and scientific calendar as one of the important departments in the ministry and includes a large number of individuals at different organizational levels for the purpose of answering a questionnaire prepared for the purpose of measurement and access to the results and the achievement of the objectives of the research and which ha

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Oct 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
The Green Regulatory Tapes and Their Reflections on the Job Development - A Study for the Sample of Employees in the Nineveh Directorate for Bridges & Roads
...Show More Authors

The performance of job effectively requires narrowing the meaningful routine activities and attempting employing the job procedures in favor of public welfare through adding the green impact as well as removing them from the red tapes which reflect the firmness of procedures, to enable the job parties to make their job independently, and pushing them to gain priority in the competition layer. This is not attaining easily amidst the regulatory problems expressed by the complication of procedures, the thing which make identifying the problem of the study through the following question:

Should we make the complex of procedures and their firmness a way to adopt the idea of the green regulatory tapes supportin

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed May 12 2021
Journal Name
Annals Of The Romanian Society For Cell Biology
The Effect of Rehabilitation Exercises Preceded by Reflexology Technique in the Rehabilitation of Patients with Frozen Shoulder: Experimental Research
...Show More Authors

Shoulder immobilization is one of the injuries that lead to disability and loss of movement in the joint within a short time, which called the researchers to find appropriate therapeutic means to rehabilitate this injury. They prepared a rehabilitation program accompanying the reflexology technique to rehabilitate the injury of the immobilized shoulder of the small degree and improve the range of movement and muscle strength working on the shoulder joint The sample was selected from the male patients aged (40-50) years. The muscle strength test was used using the force sensor, the shoulder range test from the flexion and extension position and the visual analog test to measure the level of pain. The study concluded that the pre-rehabilitati

... Show More
View Publication Preview PDF
Publication Date
Sat Sep 26 2026
Journal Name
Journal Of Engineering
Aerodynamic Characteristics of a Rectangular Wing Using Non-Linear Vortex Ring Method
...Show More Authors

The aerodynamic characteristics of general three-dimensional rectangular wings are considered using non-linear interaction between two-dimensional viscous-inviscid panel method and vortex ring method. The potential flow of a two-dimensional airfoil by the pioneering Hess & Smith method was used with viscous laminar, transition and turbulent boundary layer to solve flow about complex configuration of airfoils including stalling effect. Viterna method was used to extend the aerodynamic characteristics of the specified airfoil to high angles of attacks. A modified vortex ring method was used to find the circulation values along span wise direction of the wing and then interacted with sectional circulation obtained by Kutta-Joukowsky theorem of

... Show More
View Publication