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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
Sun Jul 02 2017
Journal Name
Journal Of Educational And Psychological Researches
The Effectiveness of Employing Microteaching in Acquiring Teaching Skills for Students Teaching The Basic Stage in Al-Aqsa University- Gaza
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The study aims to identify the effectiveness of employing microteaching in acquiring teaching skills of students teaching basic stage in Al-Aqsa University. The two researchers used the experimental method and a quota sample consisted of a group of (80) students who were distributed on the university two branches in Gaza and Khan younis and on males and females equally, and on four teaching courses counted (20) students for each. The study tool represented in an observation card ,and the results showed statistically significant differences between the level of all the skills of teaching and between the standard rate (75%) in favor of teaching skills, also showed statistically significant differences attributed to the variable of the univ

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Publication Date
Tue Jul 01 2014
Journal Name
Political Sciences Journal
Article International attitudes to change in the Arab countries in the positions of analytical Read (United States, European Union, Russia)
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المواقف افي الدول العربية قراءة تحليلية في مواقف لدولية من التغيير (الولايات المتحدة - الاتحاد الاوروبي - روسيا)

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Publication Date
Sun Sep 01 2019
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The role of target cost technology in reducing product costs: Applied Study in the General Company for Soft Drinks Industry
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The Research dealt with the role of the target costs in reducing the cost of products in the General Company for soft drinks. One the modern approaches reduce costs and thus increase the ability and continuity to compete in the market. Where the problem of research in identifying the shortcomings in the traditional method used in the company sample research. Which led to a weak control of the cost and the researcher relied on data and costs of the company. The research recommended that the target cost of the company should be applied to the research sample. Training the employees. In addition, preparing training courses for them. He stressed the need to address obstacles that prevent the existence of an effective cost system. Including t

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Publication Date
Sun Dec 01 2019
Journal Name
Journal Of Economics And Administrative Sciences
The impact of brand identity in achieving marketing objectives Applied Study in the International Company for smart card "Key Card"
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Each organization has values ​​and objectives, tangible and intangible properties of its products. The reflection of properties on the brand constitutes the identity of the brand that contributes to building the customer's convictions about the products or services provided by any organization and its brand in a positive or negative way. This is reflected in purchasing behavior, which may push forward the progress towards marketing goals or deviation from them. Therefore, the current research came to identify the brand identity, its types and the factors affecting them and how they affect to achieve each of the marketing goals. At a time when

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Publication Date
Wed Oct 15 2014
Journal Name
International Journal Of Advanced Research
A survey/ Development of Passive Optical Access Networks Technologies
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The bandwidth requirements of telecommunication network users increased rapidly during the last decades. Optical access technologies must provide the bandwidth demand for each user. The passive optical access networks (PONs) support a maximum data rate of 100 Gbps by using the Orthogonal Frequency Division Multiplexing (OFDM) technique in the optical access network. In this paper, the optical broadband access networks with many techniques from Time Division Multiplexing Passive Optical Networks (TDM PON) to Orthogonal Frequency Division Multiplex Passive Optical Networks (OFDM PON) are presented. The architectures, advantages, disadvantages, and main parameters of these optical access networks are discussed and reported which have many ad

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Publication Date
Fri Nov 11 2022
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Analytical Methods for Determination of Ketoprofen Drug: A review
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Ketoprofen has recently been proven to offer therapeutic potential in preventing cancers such as colorectal and lung tumors, as well as in treating neurological illnesses. The goal of this review is to show the methods that have been used for determining ketoprofen in pharmaceutical formulations. Precision product quality control is crucial to confirm the composition of the drugs in pharmaceutical use. Several analytical techniques, including chromatographic and spectroscopic methods, have been used for determining ketoprofen in different sample forms such as a tablet, capsule, ampoule, gel, and human plasma. The limit of detection of ketoprofen was 0.1 ng/ ml using liquid chromatography with tandem mass spectrometry, while it was 0

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Publication Date
Thu Jul 31 2025
Journal Name
مجلة واسط للعلوم الانسانية
A Schizoanalytic Reading of Crimp’s Attempts on Her Life
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The concept of Assemblage appeared obviously in Postdramatic works, where a character or a text may stand as an assemblage of potentialities in the sense that it signifies unidentified subjectivity. Assemblages are constituted essentially of heterogeneous elements yet fused without specific demarcations. In order to enjoy the desired productivity at a "smooth pace," the regularities of political and societal institutionalization are disseminated. To achieve this dissemination, Deleuze-Guattari suggest an unsatiated platform of a "Body without Organs' (BwO), where desire escapes identification. Martin Crimp (b. 1956) defines his off-stage characters in Attempts on Her Life (1997), Anne, or whatever the name is, as a 'BwO', upon which

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Publication Date
Sat Oct 27 2018
Journal Name
Bulletin Of The Iraq Natural History Museum (p-issn: 1017-8678 , E-issn: 2311-9799)
A NEW SPECIES OF CARABIDAE (NSECTA: COLEOPTERA) FROM IRAQ
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Aniera desert/cola was found new to science and to the Iraqi fauna. The description was
mainly based on external features and male genit

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Publication Date
Mon Jan 01 2024
Journal Name
Tropical Journal Of Natural Product Research
Cytotoxic Potential of Neem (Azadirachta indica A. Juss) Oil
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An increasing interest is emerging in identifying natural products to overcome drug resistance in cancer patients. In this context, the present study was conducted to investigate the cytotoxic effects of neem plant (Azadirachta indica) oil in three different biological models (breast cancer cell lines, Allium cepa root tip, and mice vital organs). The cytotoxic potential of the neem oil was evaluated with two human cell lines (MCF7 and MDA-MB231) and an Allum cepa root tip bioassay. Histopathological analysis was conducted on the neem oil-treated and untreated control mice. The results revealed an anti-proliferative effect for neem oil on both estrogen receptor-positive (MCF7) and estrogen receptor-negative (MDA-MB231) breast cancer cell li

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Publication Date
Thu Dec 01 2016
Journal Name
Bulletin Of The Iraq Natural History Museum (p-issn: 1017-8678 , E-issn: 2311-9799)
A NEW RECORD OF ZIZIPHORA SPECIES (LAMIACEAE) FOR IRAQ
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    Ziziphora persica Bunge is recorded as a new Study in Iraq. This species has been collected from Jabal Sinjar in Nineveh province in the north western part of Iraq. The morphological characters, habitat and geographical distribution of the species with a key to Ziziphora L. species in Iraq have been provided.

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