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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
Thu Jun 01 2023
Journal Name
Iraqi Journal Of Physics
Assessment of the Natural Radioactivity Levels of Soil Samples in IT1 Oil Reservoirs in Kirkuk City, Northeast Iraq
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In this study, gamma-ray spectrometry with an HPGe detector was used to measure the specific activity concentrations of 226Ra, 232Th, and 40K in soil samples collected from IT1 oil reservoirs in Kirkuk city, northeast Iraq. The “spectral line Gp” gamma analysis software package was used to analyze the spectral data. 226Ra specific activity varies from 9  0.34 Bq.kg-1 to 17  0.47 Bq.kg-1. 232Th specific activity varies from 6.2  0.08 Bq.kg-1 to 18  0.2 Bq.kg-1. 40K specific activity varies from 25  0.19 Bq.kg-1 to 118  0.41 Bq.kg-1. The radiological hazard due to the radiation emitted from natural r

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Publication Date
Wed Aug 06 2025
Journal Name
Journal Of Education For Pure Science
EFFECT OF PLANT GROWTH REGULATOR IN INCREASING THE EFFICACY OF HERBICIDES IN COMMON REED(Phragmites communis Trin.) CONTROL.
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This study was carried out in epidemically field with common reed (Phragmites communis Trin.) plants in the Nassiriah cityThiQur governorate ,during 2009/2010 to investigate the influence of plant growth regulator gibberellin (GA3)and cytokinin (CK) in increasing the efficacy of glyphosate and Fluazifop-butyl in common reed control . Factorial experiment in RCBD was used with three replications in tow Factors . Glyphosate 3500mg .l־¹ gave the higher mean of injury score of common reed and lower mean of common reed shoots , shoots dry weight and rhizome dry weight(3.59,22.01 shoot /0.5m² ,0.57Kg / 0.5m² and 250.50gm /0,5m² ),respectively. All plant growth regulators gaves the higher means of common reed shoots and rhizome dry weight com

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Publication Date
Wed Mar 23 2022
Journal Name
Journal Of Educational And Psychological Researches
School Principals’ practices of servant leadership from teachers’ perspectives in basic education schools in the Sultanate of Oman
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The study aimed to explore the school principals’ servant leadership practices for primary teachers’ perspectives in the Sultanate of Oman, furthermore to investigate the differences in those practices attributable to variables (gender, qualification, educational stage, years of experience, governorate). The study relied on the descriptive approach, by employing the survey research design using the questionnaire as a main tool for data collection, which included five dimensions of servant leadership (altruism, humility, enhancing teacher development, emotional healing, commitment to community development), Data collected from (1094) teachers in basic education schools, and they were chosen randomly. The results of the study indicated

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Publication Date
Thu Jun 15 2023
Journal Name
Bionatura
Study the effect of essential oils of some plants in protection from Cowpea beetle, Callosobruchus maculatus in laboratory
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The experiments were conducted in laboratory conditions of a temperature of 25± 2C and relative moisture of 40± 5 % to evaluate the effectiveness of the cinnamon, lavender and clove essential oils on some biological life aspects of cowpea beetle, C. maculates. Results of the obligative experiment for the effect of the oils on insect adult killing showed that the concentration of 5% caused a mortality percentage averaged 13.33% of the insect males. The mortality percentage of the insect females was 11.3% for the cinnamon and lavender oils. The lavender oil had the lowest effect on adult killing, not exceeding 0. For the effect of the oils on egg laying, clove oil affected the number of eggs highly at the concentration of 5%, result

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Publication Date
Mon Jan 01 2018
Journal Name
Int. J. Agricult. Stat. Sci. V
The role of irrigation management processes and micronutrient fertilization on parameter of growth and yield of two wheat varieties
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The experiment was conducted in Al- Mahaweel Research Station in Babel Governorate, Ministry of Agriculture during autumn season 2016-2017 to determine the role of irrigation management processes and micronutrient fertilization in growth and productivity of two varieties of wheat IPA 99 and Al-Rasheed 22 in clay loam soil classified as Typic Torriflovent. The experiment included four irrigation treatments and six fertilization treatments. The experiment was designed under randomized complete block design (RCBD) with three replications. Wheat grain IPA 99 and Al-Rasheed 22 varieties were planted in 23/11/2016 and harvested in 13/5/2017. The amount and periods of irrigation depended on sensors reading of volumetric water content was measured

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Publication Date
Sun Jul 01 2018
Journal Name
Journal Of Pharmaceutical Sciences And Research
Study of Environmental and Biological characteristics of AL-Chibaish marshes and their effect to the biodiversity of southern Iraq
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The Mesopotamian marshlands faced a massive destruction from many years and this lead to effect to ecosystem. In this study a survey was made on the physical chemical and heavy metals characteristics and microbiological analysis of AL Chibaish marsh during the two months. Water analyses revealed unacceptable values for almost all physiochemical and biological properties, according to WHO standard limits for drinking water. Almost all major ions and heavy metal concentrations in water showed a distinct decreasing trend at the marsh outlet station compared to other stations. In general, major and minor ions, as well as heavy metals exhibit higher concentrations in location 1 than in location 3. The concentrations of heavy metals in water show

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Scopus
Publication Date
Sun May 22 2016
Journal Name
Iraqi Journal Of Market Research And Consumer Protection
ESTIMATION OF SOME FOOD ADDITIVES AND HEAVY METALS IN SOME ORANGE JUICE.: ESTIMATION OF SOME FOOD ADDITIVES AND HEAVY METALS IN SOME ORANGE JUICE.
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The study included examination of three types of different origin and orange juice at the rate of recurring per sample, the results showed that the highest rates of acid (pH) in the A and juice were (4). And salts of calcium is 120 ppm in juice C and 86 ppm of magnesium in the juice B, for heavy metals the highest rate of lead .18 recorded ppm in juice B, 1.32 ppm of copper in juice A, 5 ppm of iron in the juice B, 1.3 ppm of zinc in the juice B, 0.05 ppm of aluminum in each of the sappy B and A, 0.02 ppm of cobalt in the juice B, 0.3 ppm of nickel in the juice B, 170.6 ppm sodium in C juice, but for the acids, organic that the highest rates were 3.2 part Millions of acid in the juice owner a, 260 ppm of the acid in the juice the ascorbi

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Publication Date
Fri Jun 25 2021
Journal Name
Journal Of Recent Activities In Architectural Sciences
The Electrical Shanshool to revive Al-Shanasheel in the traditional urban scene in hot dry areas
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One of the functions of Al-Shanasheel was to cool the air, but they could not compete with the Evaporative coolers, As Al-Shanasheel were a sign of luxury and wealth in Arab societies and were only built in homes of wealthy families, they are more expensive than the evaporative coolers, depending on the level of the decoration and the sculpting used to create them aesthetically, where People replaced them with evaporative coolers for their low cost, and higher cooling efficiency. One of the reasons for the disappearance of Al-Shanasheel is the absence of the functional need for them, in exchange for the high cost of construction. The diminished role of Al-Shanasheel in the contemporary urban scene, although they are one of the most

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Publication Date
Sat Jul 18 2020
Journal Name
College Of Islamic Sciences
provisions 0f the special young man in marriageability: provisions 0f the special young man in marriageability
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This research –paper tack les some of matters relating to marriageability of the young man who has not attained discretion. the aim of this study is to highlight the religious precepts concerned. the religious missive to this effect reads; ''all praise be to Allah ,lord of the world ;I witness that  there is no god but Allah, the sole and only, to him all creation is attributed. He taught man with pen, and all that he does not know, so exalted is he, and I witness that Mohammed is his servant and messenger, the master of all messengers and the seal of all prophets who was entrusted with a message of march to all mankind. May the blessings of Allah be to him, his household and companions. Until the day of Judgement. "this missive i

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Publication Date
Sun Jun 01 2014
Journal Name
Journal Of Economics And Administrative Sciences
the role of senior management commitment to total quality in the implementation of knowledge management processes_Asurvey of asample of civil colleges
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Occupies total quality management applications play a key role in the development of institutions of higher education performance and achieve its strategic objectives through the commitment of senior management and their employees to continuous improvement of the quality of performance in the various areas of work, and can be integrated knowledge management processes, which means identifying information of value and how to take advantage. The data were collected using the style of the questionnaire for the purpose of analyzing their results on a sample composed of 83 member of the administrative leadership in colleges as representing the decision-making centers in those colleges . 

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