The BEK family of flows have many important practical applications such as centrifugal pumps, steam turbines, turbo-machinery and rotor-stator devices. The Bödewadt, Ekman and von Kármán flows are particular cases within this family. The convective instability of the BEK family of rotating boundary-layer flows has been considered for generalised Newtonian fluids, power-law and Carreau fluids. A linear stability analysis is conducted using a Chebyshev collocation method in order to investigate the effect of shear-thinning and shear-thickening fluids for generalised Newtonian fluids on the convective Type I (inviscid crossflow) and Type II (viscous streamline curvature) modes of instability. The results reveal that shear-thinning power-law fluids have a universal stabilising effect across the entire BEK family of flows. However, the convective instability characteristics for the shear-thinning and shear-thickening Carreau fluids are affected by the value of the relaxation parameter k. The results reveal that Shear-thinning Carreau fluids have a small destabilising effect, while shear -thickening fluids have a slight stabilising effect on the Type I and Type II mode for the BEK family of flows when k =100. On the other hand, shear-thinning and shear-thickening Carreau fluids are found to have stabilising and destabilising effect, respectively for optimal relaxation value ko. The results are presented in terms of neutral curves and growth rates. Furthermore, an energy analysis is presented to gain insight into the underlying physical mechanisms behind the stabilising effects of generalized Newtonian fluids. In conclusion, the use of shear-thinning power-law and Carreau fluids with optimal value ko can be recommended to reduce skin-friction drag in enclosed rotor-stator devices for the entire BEK family of flows.
Abstract
The study aims to clarify the impact of the adoption of the International Financial Reporting Standard (IFRS16) on lease contracts in the General Iraqi Insurance Company on the financial statements, and thus the impact on financial ratios and indicators, Since the financial reporting standard considers lease contracts as an asset called the right to use the asset and is offset by a liability, this changes the way the financial statements are presented, with an addition to both the asset and liability sides. In order to show the extent to which the adoption of the standard reflects on the financial performance
... Show MoreThis study deals with the Spatial and Periodical Variation of the Economical Activities for the
Population of Al – Anbar Province on the level of districts , according to the Population
Computation for the period 1987 and 1997 and the results of determinations and numberings
for the year of 2011 .
This study depends on the Details Classifications of the 17th Activities for 1997 and 2011
beside the Triple Classification of the Economical Activities for the three study years .
The study proves that there is a spatial and periodical variation on the level of study area , and
that’s because of many factors , one of the most important of them was the distribution of
economical siege, as well as the weakness of the
Importance of the research:
The importance of any educational or scientific research through its intellectual arena of facts supply the individual and society, Supports Knowledge and Science Group, which raised will be locked in these topics in the future.
This research seeks to shed light on the image and the role of women and men in the books of the Arabic language in primary education (primary), To illustrate the negative effects of the phenomenon of sexism in textbooks, And its negative impact on emerging, And stay away as much as possible about the distinction between the sexes in the roles and qualities in textbooks traditional stereotypes and remove that put both sexes templates hinder the development of the individual and t
The research addresses the most important elements of the ancient Iraqi heritage represented by architecture and plastic arts being the direct means that preserved the heritage due to the ease of preserving them and the speed of circulating them and diversity of their topics. Through the features of these elements, the research problem has been defined in the form of questions including: what are the most important elements of the ancient Iraqi heritage? What are the plastic arts? What are the most important topics adopted? What is the concept of palm in the ancient Iraqi heritage? What is the evidence for that?
Has it been employed in the Iraqi contemporary art? What is the evidence for that? How to employ it in the arts and t
The aim of this paper is to find out the effects of the strategy of productive thinking upon the student’s achievement for the subject of research methodology in the College of Islamic Sciences. Achieving this objective, the researchers set the null hypotheses: (1) No difference is noticed to be statistically significant at the level of significance (0.05) among the student’s mean scores in the experimental group who were taught by the strategy of productive thinking, and the student’s mean scores in the control group who studied by the traditional method in the achievement test. (2) At level of sig. (0.05), there is no statistically significant difference in the mean of scores of the pre-tests and post ones in the achievement test of
... Show MoreThe amino acids in the liver of chick embryo was analysed for ages (7, 11, 14 and 19) days incubation and small chicken aged (14) days after hatching and adult. The study recorded (18) amino acid, the highest concentration of amino acids in the liver of embryo age (7) days incubation was Cysteine (Cys) and in small chicken aged (14) day after hatching, the following amino acids were found: Asparagine (Asn), Alanine (Ala), Histidine (His), Threonine (Thr), Valine (Val), Lysine (Lys), as well as in adult the following amino acids were recorded the highest concentration: Aspartic (Asp), Glutamic (Glu), Serine (Ser), Arginine (Arg), Proline (Pro), Glycine (Gly), Tyrosine (Tyr), Methionine (Met), Isoleucine (Ile), Leucine (Leu) and phenyl alanin
... Show MoreActual and effective organizational dynamic capabilities in the work environment contribute to a number of factors that contribute to the organization's ability to manage its human talents. Thus, the study sought to identify the level of contribution of organizational dynamic capabilities to human talent management based on their dimensions in the investigated organization by determining the level of relationship and impact between these variables. The presidency of Mosul University was chosen as a field for the current study, and data were collected by adopting the questionnaire form as the main tool for the study. The study used a deliberate sample of (42) administrative leaders in the investigated organization and adopte
... Show MoreThe recognition of the dynamic organizational capabilities in their actual and influential extent in the work environment achieves a set of positive data that can fall under the addition axes, particularly with regard to the organization's ability to manage human talents in them, so the researchers sought to identify the level of contribution of dynamic organizational capabilities in the management of human talents in terms of Keep them away in the research organization by indicating the level of relationship and impact between them. The presidency of Mosul University was chosen as a field for the current study, and data were collected by adopting the questionnaire form as the main tool for the study. The study used a deliberate
... Show MoreCowpea is a very important legume in Nigeria that is being utilized to Substitute high-cost animal protein for low-income people. The knowledge of some physical properties of various moisture contents is of utmost importance in the design of its handling and processing equipment and machinery, which is the aim of this work, which studied the physical properties of IT99K-573-1-1 (SAMPEA14) variety of Cowpea within 8.77 to 21.58 % db moisture content. The properties studied include Major, Intermediate, and Minor diameters, Sphericity, Surface area, Specific gravity, Volume, Bulk density, 50-tap density, 100-tap density, 1250-tap density, seed mass, Angle of repose, Geometric mean diameter, and Arithmetic mean diameter. The
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