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The speed, reflection and intensity of waves propagating in flexible tubes with aneurysm and stenosis: Experimental investigation
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A localized stenosis or aneurysm is a discontinuity that presents the pulse wave produced by the contracting heart with a reflection site. However, neither wave speed ( c) in these discontinuities nor the size of reflection in relation to the size of the discontinuity has been adequately studied before. Therefore, the aim of this work is to study the propagation of waves traversing flexible tubes in the presence of aneurysm and stenosis in vitro. We manufactured different sized four stenosis and four aneurysm silicone sections, connected one at a time to a flexible ‘mother’ tube, at the inlet of which a single semi-sinusoidal wave was generated. Pressure and velocity were measured simultaneously 25 cm downstream the inlet of the respective mother tube. The wave speed was measured using the PU-loop method in the mother tube and within each discontinuity using the foot-to-foot technique. The stenosis and aneurysm dimensions and c were used to determine the reflection coefficient ( R) at each discontinuity. Wave intensity analysis was used to determine the size of the reflected wave. The reflection coefficient increased with the increase and decrease in the size of the aneurysm and stenosis, respectively. c increased and decreased within stenosis and aneurysms, respectively, compared to that of the mother tube. Stenosis and aneurysm induced backward compression and expansion waves, respectively; the size of which was related to the size of the reflection coefficient at each discontinuity, increases with smaller stenosis and larger aneurysms. Wave speed is inversely proportional to the size of the discontinuity, exponentially increases with smaller stenosis and aneurysms and always higher in the stenosis. The size of the compression and expansion reflected wave depends on the size of R, increases with larger aneurysms and smaller stenosis.

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Publication Date
Wed Jan 01 2020
Journal Name
Journal Of Human Sport And Exercise - 2020 - Winter Conferences Of Sports Science
Test design to measure the cognitive processing speed of table tennis players
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Table tennis is considered one of the fast base sports that the player needs to have the speed of performance and awareness, especially in straight forward and back strikes, which is an important offensive skills, and the player success depends on his perception speed to the point of the fall of the ball in the arena of his competitor. But there is no way to measure cognitive processing speed. Therefore, the researchers sought to design a test that measures this ability to ensure its scientific evaluation, and then establish standard scores for this test for the players of the specialized school of table tennis, to help evaluate them objectively and move away from subjective estimates when evaluating and developing measuring instruments in

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Publication Date
Sat Dec 30 2023
Journal Name
Modern Sport
The effect of interactive speed exercises on developing some skills Women's futsal
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The speed of skills has become linked to modern methods of individual and group play, and each of them has begun to serve the other tactically. Through the follow-up of the researchers, they noticed that there is a significant weakness in the speed of performance and slowness in mental preparation, which plays a major role in understanding mental readiness, which is linked to the speed of making decisions during the game, as well as the weakness of the physical speed of the female players, which in turn has an impact on the skill performance of the players of the Iraqi clubs, which are the main supporter of the national team. The study aimed to identify the effect of interactive speed training on the performance of some skills among

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Publication Date
Fri Jan 01 2016
Journal Name
Journal Of Engineering
Thermal Characteristics of Closed Wet Cooling Tower Using Different Heat Exchanger Tubes Arrangement
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This paper presents thermal characteristics analysis of a modified Closed Wet Cooling Tower (CWCT) based on heat and mass transfer principles to improve the performance of this tower in Iraq. A prototype of CWCT optimized by added packing was designed, manufactured and tested for cooling capacity of 9 kW. Experiments are conducted to explore the effects of various operational and conformational parameters on the thermal performance. In the test section, spray water temperature and both dry bulb temperature and relative humidity of the air measured at intermediate points of the heat exchanger and packing. Heat exchangers consist of four rows and eight columns for an inline tubes arrangement and six rows and five columns f

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Publication Date
Wed Jun 01 2016
Journal Name
Journal Of Engineering
Investigation the Optimum Combined Dosages of Date Seeds Powder as Natural Coagulant with Chemical Coagulants in Domestic Wastewater Pretreatment
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The pretreatment process can be considered one of the important processes in wastewater treatment, especially coagulation process to decrease the strength of many pollutants. This paper focused on using powdered date seeds as natural coagulant in addition to chemical coagulants (alum and ferric chloride) to find the optimum dosage of each coagulant that makes efficient removal of turbidity and chemical oxygen demand (COD) from domestic wastewater as a pretreatment process, then finding the optimum combined dosages of date seeds with alum, date seeds with ferric chloride that make efficient removal for both pollutants. Concerning turbidity, the optimum dosage for date seeds, alum and ferric chloride were 40 mg/l (79%), 70

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Publication Date
Mon Nov 01 2010
Journal Name
Iraqi Journal Of Physics
Streams and plasma parameters experimental studies in He-CO gas mixtures
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DC glow discharges were generated between a thin cylindrical anode and a flat cathode, streamers are thought to propagate by photo-ionization; the parameters of photo-ionization depend on the He: CO ratio. Therefore we study streamers in He ( 90%, 80% and 70% ) with (10%, 20% and 30%) CO respectively. The streamer diameter is essentially the change by increase for similar voltage and pressure in all He-CO mixtures.

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Publication Date
Sat Sep 01 2012
Journal Name
Journal Of Economics And Administrative Sciences
Reflection of knowledge workers characteristics on knowledge acquision “Survey Study of the views of a sample of engineers and technicians in the Directorate of Electricity In the city of Sulaymaniyah
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Purpose: The research aims to diagnose the current availability of knowledge workers characteristics and the role of these characteristics in knowledge acquision in the city of Sulaimaniya Directorate of Electricity, and to identify the differences between personal and occupational characteristics of a sample of research and its impact on the availability of such properties.

Design/methodology/approach :to achieve the objectives of the research questionnaire was developed especially for it and then distributed to a sample of engineers and technicians working in the Directorate of Electricity city of Sulaimaniya, where the sample of the research (52) respondents.

Findings:  the most important conclusions reached

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Publication Date
Tue Jun 30 2020
Journal Name
Journal Of Economics And Administrative Sciences
Reflection of marketing deception in organizational reputation / applied research in Baghdad pharmacies
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The research aims to provide an integrated knowledge framework for the two basic research topics of (marketing deception, organizational reputation), their main dimensions, and framing the knowledge within them in a serious attempt to provide appropriate answers to the questions of the research problem by diagnosing the nature of the relationship between the components of marketing deception to identify the elements and how to activate it via reputable organizational components. The research was based on the analytical survey method. The research sample targeted (364) pharmacies within the capital Baghdad exclusively, the main tool of the research was the questionnaire, as well as the design of models prepared fo

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Publication Date
Sun Oct 01 2023
Journal Name
Baghdad Science Journal
The Influence of Ablation Speed on the Synthesis of Carbon Nanostructures Via Pulsed Laser Ablation of Asphalt in Ethanol
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Pulsed liquid laser ablation is considered a green method for the synthesis of nanostructures because there are no byproducts formed after the ablation. In this paper, a fiber laser of wavelength 1.064 µm, peak power of 1 mJ, pulse duration of 120 ns, and repetition rate of 20 kHz, was used to produce carbon nanostructures including carbon nanospheres and carbon nanorods from the ablation of asphalt in ethanol at ablation speeds of (100, 75, 50, 10 mm/s).  The morphology, composition and optical properties of the synthesized samples were studied experimentally using FESEM, HRTEM, EDS, and UV-vis spectrophotometer. Results showed that the band gap energy decreased with decreasing the ablation speed (increasing the ablation time), the mi

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Publication Date
Fri Jan 15 2021
Journal Name
Plant Archives
STUDY OF THE EFFECT OF SPEED, DEPTH OF THE CULTIVATION AND THE NUMBER OF TIMES THE SPRING – LOADED CULTIVATOR PASSES ON SOME TECHNICAL PARAMETERS OF THE CULTIVATOR AND ON WEED CONTRO
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Publication Date
Fri Jan 01 2021
Journal Name
Plant Archives
STUDY OF THE EFFECT OF SPEED, DEPTH OF THE CULTIVATION AND THE NUMBER OF TIMES THE SPRING – LOADED CULTIVATOR PASSES ON SOME TECHNICAL PARAMETERS OF THE CULTIVATOR AND ON WEED CONTROL
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