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Theoretical and Experimental Reflection Coefficients in Flexible Tubes as a Function of the Mach Number
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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.

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Publication Date
Wed Dec 30 2015
Journal Name
College Of Islamic Sciences
Linguistic correction To some modern narrators In the book (Reforming the error of the modernists) For the Orator (d. 388 AH)
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Il semble que Khattabi était un linguiste, avec un endroit linguistique pour comprendre les textes de conversations et des mots étranges en particulier. Langue, et chacun avait ses arguments et ses preuves. Ses corrections incluaient la mélodie dans les mouvements, telle qu'une dilution plus serrée, la dilution de l'agitateur, le remplacement d'un autre mouvement, ou une autre rotation des mouvements, et le changement de structure morphologique du mot qui en résultait, ainsi que l'alerte sur les conséquences des lettres, Certaines de ces erreurs sont dues à la langue, et certaines sont considérées comme un type de déformation ou de fausse représentation connue de certains spécialistes, ce qui constitue un précédent louable

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Publication Date
Wed Jun 30 2021
Journal Name
Journal Of Economics And Administrative Sciences
The Impact of Innovative Marketing on the Organization's Reputation by Mediating the Brand _ Field Research in the Oil Marketing Company (SOMO)
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The research aims to verify that there is an influence between innovative marketing and the organization's reputation by brand mediation.

The research problem is that the Oil Marketing Company (SOMO) needs innovative, unconventional methods in marketing its products and improving its reputation by adopting a solid brand that adds value to the product.

The importance of the research: The importance of the research is highlighted as it deals with essential variables in business organizations that help increase customer loyalty by adopting a distinctive brand.

The research started from four main hypotheses to explore correlations and influence between researc

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Publication Date
Sat Mar 25 2023
Journal Name
Kirkuk University Journal For Agricultural Sciences
The role of the agricultural extension in educating farmers about the legislation on protecting the environment from pollution with chemical pesticides
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The research aimed to determine the role of the agricultural extension in educating farmers about the legislation on the protection of the rural environment from pollution with chemical pesticides working in the Department of Agricultural Extension and Training and the Department of Agricultural Extension in the directorates of agriculture of Najaf and Qadisiyah, and to determine the role of the agricultural extension in the axis of farmers' use of the correct methods to protect the rural environment from pollution with chemical pesticides and the axis of the reasons that lead farmers to pollute the rural environment with chemical pesticides, and to achieve the objectives of this research prepared A questionnaire in the light of rev

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Publication Date
Thu Nov 13 2025
Journal Name
Journal Of Physical Education
The Effect of Using Especial Exercises Suggested for Developing of Accuracy Direction by Fencing in Foil for the Players of the National Team of the Young who Handicap
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Publication Date
Mon Mar 25 2019
Journal Name
Al-academy
The Impact of Educational Techniques in Developing Teaching Skills of Apprentice Students in the Faculty of Fine Arts - Diyala University: عمر قاسم علي - رجاء حميد رشيد
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For the purpose of achieving the desired goal of the educational learning process, it was necessary to devote attention to educational means and employ them in this field because of their great role in overcoming the difficulties facing the learning process and providing an educational environment that keeps abreast of the scientific developments. This is the goal of the research in which the researchers wanted to know the effect of the educational techniques in the development of apprentice students' skills in teaching.
The research consisted of the problem of the research which is: what is the impact of educational techniques on developing the apprentice students' teaching skills in the Faculty of Fine Arts? In addition to its imp

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Publication Date
Thu Jun 01 2017
Journal Name
Journal Of Economics And Administrative Sciences
A Comparison Between Maximum Likelihood Method And Bayesian Method For Estimating Some Non-Homogeneous Poisson Processes Models
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Abstract

The Non - Homogeneous Poisson  process is considered  as one of the statistical subjects which had an importance in other sciences and a large application in different areas as waiting raws and rectifiable systems method , computer and communication systems and the theory of reliability and many other, also it used in modeling the phenomenon that occurred by unfixed way over time (all events that changed by time).

This research deals with some of the basic concepts that are related to the Non - Homogeneous Poisson process , This research carried out two models of the Non - Homogeneous Poisson process which are the power law model , and Musa –okumto ,   to estimate th

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Publication Date
Thu Dec 01 2011
Journal Name
Journal Of Economics And Administrative Sciences
Dynamic algorithm (DRBLTS) and potentially weighted (WBP) to estimate hippocampal regression parameters using a techniqueBootstrap (comparative study)
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Bootstrap is one of an important re-sampling technique which has given the attention of  researches recently. The presence of outliers in the original data set may cause serious problem to the classical bootstrap when the percentage of outliers are higher than the original one. Many methods are proposed to overcome this problem such  Dynamic Robust Bootstrap for LTS (DRBLTS) and Weighted Bootstrap with Probability (WBP). This paper try to show the accuracy of parameters estimation by comparison the results of both methods. The bias , MSE and RMSE are considered. The criterion of the accuracy is based on the RMSE value since the method that provide us RMSE value smaller than other is con

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Publication Date
Fri Jul 27 2012
Journal Name
Journal Of Prosthodontics
A Three-Dimensional Finite Element Analysis for Overdenture Attachments Supported by Teeth and/or Mini Dental Implants
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Publication Date
Tue Dec 01 2015
Journal Name
Journal Of Engineering
Importance of New Use of Concrete in Iraq Analysis of Development And Use of Concrete in Architecture
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Since its invention by the Ancient Romans and later developed during the mid-18th century, the concrete structure and finish, has been considered as the most powerful, practical, economic and constructional material that meets the building’s architectural and aesthetical requirements. By creating unique architectural forms, the pioneer architects used concrete widely to shape up their innovative designs and buildings.

The pre-mixed ultra-high performance concrete which manufactured by Lafarge.

The transparent concrete and cement that allow the light beams to pass through them, introduces remarkable well-lit architectural spaces within the same structural criteria. This product is a recyclable, sustainab

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Publication Date
Sun Sep 02 2012
Journal Name
Baghdad Science Journal
Study The Predation Efficiency of Chrysoperla carnea (Stephens)(Neuroptera :Chrysopidae) Larvae in Controlling Nymphs and Adults of Cabbage Aphid Brevicoryne brassicae (L.) (Homoptera :Aphididae).
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Results showed high efficiency of the predator Chrysoperla carnea (Stephens) to attack and consume nymphal instars and adults of cabbage aphid, Brevicoryne brassicae (L.).The total average of the nymphal instars consumed by the larval stage of predator were 308.67, 285.9, 198.77, 154.7 for 1st ,2nd ,3rd ,4th nymphal instars respectively .While it was 110,107.9 for apterae and alatae respectively . Also, predation efficiency increases with the progress of the larval instars up to the third (last) which was the most voracious .The 1st instar nymph consumed by the larvae of the predator were 47,80,181.67 nymphs ,with predation rate of 14.71% , 23.75% and 50.13% for 1st ,2nd and 3rd larval instars

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