In this paper, the problem of developing turbulent flow in rectangular duct is investigated by obtaining numerical results of the velocity profiles in duct by using large eddy simulation model in two dimensions with different Reynolds numbers, filter equations and mesh sizes. Reynolds numbers range from (11,000) to (110,000) for velocities (1 m/sec) to (50 m/sec) with (56×56), (76×76) and (96×96) mesh sizes with different filter equations. The numerical results of the large eddy simulation model are compared with k-ε model and analytic velocity distribution and validated with experimental data of other researcher. The large eddy simulation model has a good agreement with experimental data for high Reynolds number with the first, second and third mesh sizes and the agreement increase near the wall of the duct. The percentage error for the large eddy simulation model with experimental data of the (56×56) mesh size is less than 18 % and for the (76×76) mesh size is also less than 17% and for the (96×96) mesh size is less than 16 %. The large eddy simulation model show high stability and do not need extra differential equation like the k-ε model and a great saving in time and computer memory was achieved.
This research aims to identify the impact of the selective model in acquiring the concepts of Kurdish grammar among female students in the eighth grade, and to achieve the goal of research, the researcher selected the experimental design with partial control and dimensional testing; the sample includes basic schools in the Chim district of Chamal/ Sulaymaniyah and randomly selected the basic school (Maha Bad) to be the field of application of the experiment and the random drawing method was chosen: two out of three sections and the number of students of the two sections is (75) students; section (C) represents the experimental group that studied the rules according to the selective model and its number is (37) students, while secti
... Show MoreDust storms are typical in arid and semi-arid regions such as the Middle East; the frequency and severity of dust storms have grown dramatically in Iraq in recent years. This paper identifies the dust storm sources in Iraq using remotely sensed data from Meteosat-spinning enhanced visible and infrared imager (SEVIRI) bands. Extracted combined satellite images and simulated frontal dust storm trajectories, using the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model, are used to identify the most influential sources in the Middle East and Iraq. Out of 132 dust storms in Iraq during 2020–2023, the most frequent occurred in the spring and summer. A dust source frequency percentage map (DSFPM) is generated using ArcGIS so
... Show MoreThe researcher attempts to examine Barman model in acquiring the historical concepts among fourth-grade students at literary classrooms. To this end, the researcher held the null hypothesis, there is no significant difference between the experimental groups who was taught based on Barman model and the control group that taught based on the traditional method in acquiring the historical concepts on the post-test. To testify the effectiveness of Barman model, the researcher administered a questionnaire included (60) items on bunch of female-students who were selected from al-khamaeal preparatory school in al-hurriyah district in Baghdad. The author utilized different statistical tools to analyze the collected data. &
... Show MoreMultilocus haplotype analysis of candidate variants with genome wide association studies (GWAS) data may provide evidence of association with disease, even when the individual loci themselves do not. Unfortunately, when a large number of candidate variants are investigated, identifying risk haplotypes can be very difficult. To meet the challenge, a number of approaches have been put forward in recent years. However, most of them are not directly linked to the disease-penetrances of haplotypes and thus may not be efficient. To fill this gap, we propose a mixture model-based approach for detecting risk haplotypes. Under the mixture model, haplotypes are clustered directly according to their estimated d
The two body model of (Core+n) within the radial wave functions of the cosh potential has been used to investigate the ground state features such as the proton, neutron and matter densities, the root mean square (RMS) nuclear proton, neutron, charge and mass radii of unstable neutron-rich 14B, 15C, 19C and 22N nuclei. The calculated results show that the two body model with the radial wave functions of the cosh potential succeeds in reproducing neutron halo in these nuclei.
إن تجسيد الشعراء للجمال واقامته تمثالا مصورا مرئيا ، كان الهدف منه اولا اشاعة جو نفسي مريح في مقدمات قصائد المديح ، فهو الجزء البصري الممتع لمدركات حسية اخرى ترافقه، وأما المرامي الاخرى
ﻓﮭﻲ إﻣﺘﺎع اﻟﻨﻔﺲ إﻣﺎ ﺑﺎﺳﺘﺮﺟﺎع أﺟﻤﻞ ﺻﻮرة أو أﻧﻤﻮذج ﻗﺎﺋﻢ ﻓﻲ اﻟﺬاﻛﺮة، وﺟﻌﻠﮫ ﯾﺤﯿﺎ ﻣﻦ ﺟﺪﯾﺪ ﻟﺪواﻋﻲ اﻟﺤﻨﯿﻦ للاماكن والازمنة الاثيرة . أو الميل للتعبير عن الوعي الجمالي الذي يتصل بموضوع الج
... Show More<p>The speech act of request is face-threatening by nature and an inappropriate request can cause offence to the hearer, particularly when s/he has higher authority (Economidou-Kogetsidis, 2011). E-mail is frequently used to facilitate communication between student and professor in Iraq. Iraqi EFL (English as a foreign language) learners face pragmatic difficulty in making proper requests to individuals of higher authority via e-mail. Some studies have been conducted on Arab EFL learners to uncover the pragmatic behaviour of these learners in real-life requests using elicited data. This research fills a gap in Inter-language Pragmatics (ILP) literature in that it investigates the use of academic request in three diverse imposi
... Show MoreCities have witnessed great changes since the planning of the first cities. This is due to the increase in population and problems in services that affect urban security. As such, urban security is directed and affected by the nature of city planning and the types of services. Besides, the kind of services plays an imminent place in providing urban security at all levels. Other factors that influence urban security can be limited to the increase of population, economic and social changes. This leads to losing urban control. This study will explore the historical chronology to identify weaknesses in urban planning since its dawn and reaching solutions to protect urban security. The importance of the research lies in achieving urban securi
... Show MoreBackground: Cervical lymph nodes are the most frequently enlarged and biopsied of all the peripheral lymph nodes and in most of the cases the enlargement results from benign infectious causes, however, the presence of cervical lymphadenopathy (LAP) requires accurate diagnosis to exclude more serious causes. The aim of this study was to analyze cases of Iraqi patients presenting with cervical LAP who underwent surgical lymph node biopsy to establish accurate diagnosis. Materials and Methods: This retrospective study included 25 patients who presented with cervical LAP for whom surgical biopsy was performed to establish a definitive diagnosis. The investigated data included the demographic and clinical parameters in addition to the final his
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