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.
Praise be to God, who made the pegs of the earth and entrusted them with the task of keeping the earth from tilting, and prayers and peace be upon the one to whom the Qur’an was revealed, Muhammad, and upon his family and all his companions.
The topic of mountains is one of the important topics in human life, as God has associated great miracles with them that indicate the perfection of the power of God Almighty. God Almighty says: (And to the mountains, my palms have turned. This is worthy of every rational person to contemplate His signs, the Almighty, in this solid part and safety belt of the earth, in order to reveal the secrets of the mountains and uncover their treasures. The more the researcher studies the mountains and
... Show MoreElegy is one of the foundations of the Arab poetic heritage, and it is one of the main sections of poetry. Man has found in him his desire to express his innermost self at an hour filled with pain, and an outlet from which his anguish and grief come out in an expressive form that liberates tears and reproaches death.
Lamentation is an evolving purpose that grows with the growth of society and life and records the change that takes place in every stage of history. It is an important result of the poet's collision with life and events.
That is why I chose the lamentation poetry of Hafiz Ibrahim, due to the importance of this art to him, and it is the art in which he excelled the poets of his time.
I have divided this research into
A theoretical investigation is carried out to study the effect of a pencil electron beam propagating inside the plasma region determining the hydrodynamic densities distribution with the aid of numerical analysis finite deference method (FDM).The plasma is generated and trapped by annular electron beams of fixed electron density 1x1014 m-3. The result of the study shows that the hydrodynamic density behaves as the increase in pencil electron beam. The hydrodynamic density ratio goes to more than double as the increase in pencil electron beam density to 1x1018 m-3.
Leiomyosarcoma (smooth muscle tumor) is a rare type of a malignant neoplasm of smooth
muscle. It is a resistant cancer, generally not very responsive to chemotherapy, radiationand surgery.The
aim of this study was to evaluate photodynamic therapy (PDT) as a possible basis for treatment using
(650 nm)diode laser with methyleneblue (MB) as a photosensitizer on leiomyosarcoma (LMS)cell line
(L20B) in vitro. The cytotoxic effects of 650nm diode laser 0.052 W/cm2 (power density) at different
exposure time (10, 20, and 30 min) with methylene blue at different concentrations (0.01% ,0.1 % ,1%)
was investigated on LMS cell line (L20 B). The cytotoxic effect of laser was increased with increasing
irradiation time for a certai
Pancreatic adenocarcinoma is one of the major causes of cancer death in the world. Alterations in p53 tumor suppressor gene
Nanotechnology extends the limits of molecular diagnostics to the nanoscale. This study describes some of the details of how the body interacts with nanoparticles. Biological tests measuring the presence or activity of selected substances become quicker, more sensitive, and more flexible when certain nanoscale particles are put to work as tags. Particular emphasis is placed on the effects of surface changes on body-borne particles, their transport within the body, and the dose-response effect. Other considerations include the definition of "persistent" in the context of therapy, FDA scientific committees, and the need for nanoparticle tracking. In short, there have been dramatic changes in molecular and genetic research findings, as well as
... Show MoreReading Trend in the Recent school book
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Rheumatoid arthritis (RA) is one of the autoimmune diseases characterized by the synovial inflammation which causes organs and tissues damage especially synovial tissues and joints. The study included 50 serum samples from patients with rheumatoid arthritis (RA) when compared with 50 serum samples from healthy individuals as control with age range 35 – 60 years (41.3 ± 2.4 years vs. 41.0 ± 2.0 years, respectively). ELISA technique was used to assess the Anti-cyclic citrullinated peptide IgG antibody (anti-CCP IgG Ab) level, anti-rheumatoid factor IgG antibody (anti-RF IgG) and anti-Cytomegalovirus (anti-CMV IgG) antibodies frequencies in the studied groups. The present findings demonstrated that all RA patients have 100% seropositive fr
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