Preferred Language
Articles
/
mBflto0BVTCNdQwCFRkA
Theoretical and Experimental Reflection Coefficients in Flexible Tubes as a Function of the Mach Number
...Show More Authors

The standard formulation of Wave Intensity Analysis (WIA) assumes that the flow velocity (U) in the conduit is <;<; the velocity of propagation of waves (c) in the system, and Mach number, M=U/c, is negligible. However, in the large conduit arteries, U is relatively high due to ventricular contraction and c is relatively low due to the large compliance; thus M is > 0, and may not be ignored. Therefore, the aim of this study is to identify experimentally the relationship between M and the reflection coefficient in vitro. Combinations of flexible tubes, of 2 m in length with isotropic and uniform circular cross sectional area along their longitudinal axes, were used to present mother and daughter tubes to produce a range of reflection coefficients. An approximately semi-sinusoidal pulse was generated at the inlet of the mother tube using a syringe pump, first in the condition of initial velocity, U 0 =0, and when U 0 >0 with steady flow to superimpose the pulse. Pressure (P) and Velocity (U) were measured in the mother tube, wave speed was determined using the foot to foot and PU-loops methods. The theoretical reflection coefficient, R t at M=0, has been compared to the experimental reflection coefficient, R at M>0, which was determined as dP-/dP+ as calculated using WIA. The function R(M) changes significantly with the geometrical and mechanical features of the connected tubes. In our experiments, R increased significantly with small values of M. In the range of M=0-0.02, R increased by 4-36%. Therefore, we conclude that M significantly affects the magnitude of reflections.

Scopus Clarivate Crossref
View Publication
Publication Date
Tue Nov 01 2016
Journal Name
Journal Of Economics And Administrative Sciences
Reflection Leader-Member Exchange In Organizational Commitment A Field research in Ministry of Iraqi Defense
...Show More Authors

Abstract

The researcher seeks, through different aspects of the search, to reach a set of objective concerning in content creation a clear vision about conceptual and practical dimension of relation and effects between (Leader-Member Exchange, and Organizational Commitment) to construct a framework of a pragmatic model as a solution to research problem and it questions. The theoretical problem is derived basically from the scarcity of Arab studies and researches that deal by study and analyses for such important of The two variables blend. The practical problem depends in deriving from reality of every day work in the Iraqi ministry of defense.

On this basis, a formula of research problem for pur

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Jul 30 2020
Journal Name
Journal Of Sustainability Science And Management
THE DIFFERENTIATION IN WORK ENRICHMENT STRATEGIES AND ORGANIZATIONAL CREATIVITY FUNCTION: A PERSPECTIVE FROM THE LEADERS OF THE MINISTRY OF OIL IN IRAQ
...Show More Authors

View Publication
Scopus (5)
Crossref (2)
Scopus Crossref
Publication Date
Fri Apr 29 2016
Journal Name
Iraqi Journal Of Market Research And Consumer Protection
The net effect of the nominal protection coefficients in the production of table eggs and poultry meat in Iraq For the period 1990- 2013.: The net effect of the nominal protection coefficients in the production of table eggs and poultry meat in Iraq For the period 1990- 2013.
...Show More Authors

The research aims to measure the net nominal protection coefficients for the products table eggs and poultry meat and the extent of its impact on domestic production volume for the period of 1990- 2013 has been the use of mathematical formulas simplified in the calculation of the transaction process with a view to the extent of support and protection offered by the state pricing policy for products Resources Sector Animal in Iraq and reach search Highlights and most important, there are volatile price state policy with regard to eggs and poultry meat, as it ranged net nominal protection coefficients between the larger and less than the right one, which means that values are unstable to support local producers or consumers, and can be The

... Show More
View Publication Preview PDF
Publication Date
Mon Oct 01 2018
Journal Name
Arpn Journal Of Engineering And Applied Sciences
Achieving a theoretical approximation characterize the stopping power of heavy ion in D-T plasma
...Show More Authors

The dependence of the energy losses or the stopping power for the ion contribution in D- T hot plasma fuels upon the corresponding energies and the related penetrating factorare arrive by using by a theoretical approximation models. In this work we reach a compatible agreement between our results and the corresponding experimental results.

View Publication Preview PDF
Scopus
Publication Date
Sun Jan 01 2023
Journal Name
Technologies And Materials For Renewable Energy, Environment And Sustainability: Tmrees22fr
A theoretical enhancement of electronic transfer dynamics in the D35CPDT dye donor to 𝑻𝒊𝑶𝟐 acceptor
...Show More Authors

View Publication
Crossref
Publication Date
Fri Feb 28 2020
Journal Name
Neuroquantology
Studying the Swarm Parameters and Electron Transport Coefficients in N2– CH4 Mixtures Using BOLSIG+ Program
...Show More Authors

View Publication
Scopus Crossref
Publication Date
Wed Nov 01 2023
Journal Name
International Society For The Study Of Vernacular Settlements
Using Modern Techniques in the Formation of Flexible Interior Spaces: Insights from Iraq
...Show More Authors

View Publication
Scopus Crossref
Publication Date
Thu May 11 2023
Journal Name
Engineering Applications Of Computational Fluid Mechanics
Photovoltaic-thermal system combined with wavy tubes, twisted tape inserts and a novel coolant fluid: energy and exergy analysis
...Show More Authors

To create a highly efficient photovoltaic-thermal (PV-T) system and maximise the energy and exergy efficiency, this study aims to propose an innovative configuration of a PV-T system comprising wavy tubes with twisted-tape inserts. Following the validation of a numerical model, a parametric study has been conducted to assess the geometrical effects of twisted tape and wavy tubes, as well as the coolant fluid type and velocity, on the overall performance of a PV-T system, located in Shiraz, Iran. It is found that employing twisted tape improves the energy and exergy efficiency by approx. 6.3%. The best configuration yields 12.4% and 16.8% increase in energy and exergy efficiency compared to conventional PV systems. This is achieved at 15% vo

... Show More
View Publication
Scopus (14)
Crossref (8)
Scopus Clarivate Crossref
Publication Date
Thu Dec 01 2016
Journal Name
Journal Of Economics And Administrative Sciences
Organizational Ethnography and its Reflection in the Resonant LeadershipCase study at the University of Kufa
...Show More Authors

ABSTRACT

The purpose of this research is to investigate the relationship between organizational ethnography and resonant leadership in the University of Kufa, importance of research includes rare of studies that investigated the relationship between organizational ethnography and resonant leadership. Moreover, it comes as an attempt to reduce or bridge the knowledge gap between the variables of the research. As well as try to put the right foundations and appropriate for industry leaders of various Iraqi organizations aimed at profit or service. Based on the random sampling, 450 questionnaires were distributed to employees at the University of Kufa. Only 392 questionnaires were returned. Out of which 104 questionnaires we

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Jan 01 2013
Journal Name
Brain Research Bulletin
A note on the probability distribution function of the surface electromyogram signal
...Show More Authors

View Publication
Scopus (81)
Crossref (85)
Scopus Clarivate Crossref