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.
It is the dynamic tension between the relatively fixed built environment and the constantly changing in social life that determines the nature of urban spaces belonging to different historical periods, and considered as a tool for diagnosing transformations in urban spaces, that’s why, the characteristics of urban space became unclear between positive spaces and negative spaces, so emerged the need to study contemporary urban space belonging to the current period of time and show the most important transformations that have occurred in contemporary urban space to reach urban spaces that meet the current life requirements. Therefore, the research dealt with a study of the characteristics of contemporary urban space and the most pr
... Show MoreThe childhood of the important stages in which the adopted child's personality, mental and physical, motor and configure , as well as gain experience , it is the basis on which the future life of the child , studies have unanimously competent in the fields of childhood verily the first five years of a child of the most important stages of life and the most fertile life . Because the stage Childhood its an active role as the foundation upon which to build human personality , it was necessary to create all leads to raise the level of intelligence of children , because intelligence is the first element in the organization of thinking makes the child able to do the activities characterized by mental qualities .
Indicated most of the scien
Source, sedimentation, coagulation, flocculation, filter, and tank are parts of a water treatment plant. As a result, some issues threaten the process and affect the drinking water quality, which is required to provide clean drinking water according to special standards and international and local specifications, determined by laboratory results from physical, chemical, and biological tests. In order to keep the water safe for drinking, it is necessary to analyze the risks and assess the pollution that occurs in every part of the plant. The method is carried out in a common way, which is monitoring through laboratory tests, and it is among the standards of the global and local health regulators
Examining the pictures of the scientific miracles in Surat Al-Ra’d revealed to us - as all other verses of miracles revealed - the truth of the prophecy of our noble Messenger (may God bless him and his family and grant him peace) in receiving the verses of the Qur’an from God Almighty through revelation. It is not possible to talk about cosmic phenomena and their secrets in this way. Fourteen centuries ago, when scientific techniques, observational devices, space surveys, and means of science were non-existent, except for what is related to eye observation, transmitted experiences, and even observation is unable to explain many phenomena near as well as distant ones. The interpretations that are tainted by myth in the books
... Show MoreMultiple myeloma (MM) is a heterogenous plasma cell malignancy with various complications. Sclerostin is a Wingless-type (Wnt) inhibitor specifically expressed by osteocytes; it acts as a negative regulator of bone formation.
To assess plasma sclerostin level in MM patients and find its correlations with clinical and laboratory data, including osteolytic bone disease and international staging system (ISS).
This cr
The aim of this research is subjected to discover The Dictation mistakes which occur
widely in the Arabic Language written by Iraqi – News papers.
The research classified These Mistakes in Three groups as Follows:
1. The first group dealing with distinguishing between the Arabic – letter ) ا ( When Written
or ) أ ( at The beginning The word and as ) ئ ( which differ in meaning from each other .
2. The second group dealing with the writing of The Arabic ) ٙ( and as ) ٛ( at the end of The
word which differ in meaning from each other.
3. The Third group dealing with distinguishing in written The Arabic letter as ) ض( or as ) )ظ
which differ in meaning From each other.
4. The fourth group dealing with Th
In this thesis, we study the topological structure in graph theory and various related results. Chapter one, contains fundamental concept of topology and basic definitions about near open sets and give an account of uncertainty rough sets theories also, we introduce the concepts of graph theory. Chapter two, deals with main concepts concerning topological structures using mixed degree systems in graph theory, which is M-space by using the mixed degree systems. In addition, the m-derived graphs, m-open graphs, m-closed graphs, m-interior operators, m-closure operators and M-subspace are defined and studied. In chapter three we study supra-approximation spaces using mixed degree systems and primary object in this chapter are two topological
... Show MoreFree boundary problems with nonlinear diffusion occur in various applications, such as solidification over a mould with dissimilar nonlinear thermal properties and saturated or unsaturated absorption in the soil beneath a pond. In this article, we consider a novel inverse problem where a free boundary is determined from the mass/energy specification in a well-posed one-dimensional nonlinear diffusion problem, and a stability estimate is established. The problem is recast as a nonlinear least-squares minimisation problem, which is solved numerically using the
I often read in Islamic jurisprudence in all chapters as much as possible from divine success, time and health, and everything I read in any of the chapters of jurisprudence, I see divine light, eternal wisdom, and a constitution that does not accept error and alteration, as I looked at the great jurisprudential treasures and this enormous wealth, A person finds in himself helplessness in front of this law, how clear, easy, and accurate it is, and it contains permanent good for man, as it is a religion of mercy, benevolence, and goodness, and among these chapters of jurisprudence is the jurisprudence of the commandment. Of the reasons, in the will, the person has had the opportunity to make up for what he missed of doing good that a pers
... Show MoreBackground: The access cavity is a critical stage in root canal therapy and it may influence the subsequent steps of the treatment. The new minimally invasive endodontic access cavity preparation concept aims to preserve sound tooth structure by conserving as much intact dentine as possible including the pulp chamber's roof, to keep the teeth from fracturing during and after endodontic treatment. While there is great interest in such access opening designs in numerous publications, still there is a lack of scientific evidence to support the application of such modern access cavity designs in clinical practice. This review aims to critically examine the literature on minimal access cavity preparations, explain the effect of minimally inva
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