Preferred Language
Articles
/
HhegRo4BVTCNdQwCKkDX
Natural Convection in Annulus Between Two Concentric Cylinders Partially Filled with Metal Foam Distributed with New Suggested Design
...Show More Authors
Abstract<p>The investigation of natural convection in an annular space between two concentric cylinders partially filled with metal foam is introduced numerically. The metal foam is inserted with a new suggested design that includes the distribution of metal foam in the annular space, not only in the redial direction, but also with the angular direction. Temperatures of inner and outer cylinders are maintained at constant value in which inner cylinder temperature is higher than the outer one. Naiver Stokes equation with Boussinesq approximation is used for fluid regime while Brinkman-Forchheimer Darcy model used for metal foam. In addition, the local thermal equilibrium condition in the energy equation of the porous media is presumed to be applicable for the present investigation. CFD ANSYS FLUENT software package (version 18.2) is used as a solver to this problem. Various parameters are examined; Rayleigh number, Darcy number, and thermal conductivity ratio to study the effect of them on fluid flow and heat transfer inside the annuli space in the suggested design of metal foam layer. current model is compared with the available published results and good agreement is noticed. Results showed that as Rayleigh number increases the dominated of convection mode increases and Nusselt increases. Also, Nusselt is larger at the higher Darcy and thermal conductivity ratio. It was found that at Rayleigh of 10<sup>6</sup> and thermal conductivity ratio of 10<sup>4</sup> Nusselt reach its higher value which is 6.69 for Darcy of 0.1 and 6.77 for Darcy of 0.001. A comparison between this design and the traditional design was established for Darcy 0.001 and thermal conductivity ratio 10<sup>2</sup>, and its showed a good enhancement in Nusselt number and the greatest enhancement percentage was 44% at Rayleigh equal 5*10<sup>4</sup> while the lowest percentage is 6% for Rayleigh equal10<sup>6</sup>.</p>
Scopus Crossref
View Publication
Publication Date
Mon Mar 07 2022
Journal Name
Journal Of Educational And Psychological Researches
The Impact of Cognitive Behavior Program Based on Meichenbaum Theory in Reducing the Negative Emotional Sensitivity among the Intermediate Stage Students
...Show More Authors

The aim of this research is to construct a cognitive behavior program based on the theory of Meichenbaum in reducing the emotional sensitivity among Intermediate school students. To achieve the aims of the research, two hypotheses were formulated and the experimental design with equal groups was chosen. The population of research and its sample are determined. The test of negative emotional sensitivity, which is constructed by the researcher, was adopted. The test contains (20) items proved validity and reliability as a reliable test by presenting it to a group of arbitrators and experts in education and psychology. An educational program is constructed based on the theory of Meichenbaum. The test was applied to a sample of (60) second i

... Show More
View Publication Preview PDF
Publication Date
Mon Mar 13 2017
Journal Name
Journal Of Baghdad College Of Dentistry
The Effects of Enamel Protective Agents on Shear Bond Strength After Rebonding of Stainless Steel Orthodontic Bracket (An in Vitro Study)
...Show More Authors

ABSTRACT Background: Bracket rebonding is a common problem in orthodontics which may result in many drawbacks. The aims of this study were to evaluate the effects of application of two enamel protective agents “Icon” and “ProSeal” on shear bond strength before and after rebonding of stainless steel orthodontic brackets using conventional orthodontic adhesive and to assess the site of bond failure. Materials and methods: Fifty sound extracted human upper first premolar teeth were selected and randomly divided into two equal groups; the first time bonding and the rebonding groups (n=30). Each group was subdivided into control, Icon and ProSeal subgroups. The enamel protective agents were applied after etching (precondi

... Show More
View Publication Preview PDF
Crossref (5)
Crossref
Publication Date
Fri Sep 15 2017
Journal Name
Journal Of Baghdad College Of Dentistry
Comparison of Shear Bond Strength of Sapphire Bracket Bonded to Zirconium Surface after Using Different Surface Conditioning Methods (In Vitro Study)
...Show More Authors

Background: The present study was carried out to compare shear bond strength of sapphire bracket bonded to zirconium surface after using different methods of surface conditioning and assessment of the adhesive remnant index. Materials and methods: The sample composed of 40 zirconium specimens divided into four groups; the first group was the control, the second group was conditioned by sandblast with aluminum oxide particle 50 μm, the third and fourth group was treated by (Nd: YAG) laser (1064nm)(0.888 Watt for 5 seconds) for the 1st laser group and (0.444 Watt for 10 seconds) for the 2nd laser group. All samples were coated by z-prime plus primer. A central incisor sapphire bracket was bonded to all samples with light cure adhesive res

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Tue Jan 29 2019
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The Impact of Tax Laws and Decisions in Determining the Tax Base of the Results of the Financial Statements of Companies
...Show More Authors

This research aims to measure the discrepancy between the accounting income which is prepared according to generally accepted accounting principles and the tax income that is being prepared according to the rules and tax laws, and find out the most important differences that arise between incomes.The research found the most important to the following conclusions:1.Faces determining the tax base for companies subject to income challenges related to the weakness of the efficiency and the possibility of technical angel tax and its ability to examine the financial statements submitted to the tax administration tax.2.That the tax system in Iraq does not comply with accepted accounting principles generally accepted.The research recommends the

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sat Sep 01 2018
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Difficulties of scientific research in the financial and administrative fieldaccording to the quality standardsfrom the point of view of the teachers
...Show More Authors

The research aims to identify the most important difficulties facing the scientific research in the technical university in the financial, organizational and administrative according to the quality standards according to the paragraphs studied in the questionnaire questionnaire prepared for this purpose, including the research community on the Central Technical University, which includes several technical colleges and technical institutes were selected A sample of the researchers in the Institute of Technical Management where the number of training was 78 teachers took a random sample of researchers amounted to 40% of the questionnaire, and after the collection and classification of data were used statistical means, including the mean ar

... Show More
View Publication Preview PDF
Crossref
Publication Date
Fri Mar 15 2019
Journal Name
Journal Of The College Of Education For Women
The Impact of Anticyclones Merge on the Temperature in the stations of Mosul, Baghdad and Basra for the Period (2005-2015)
...Show More Authors

           The Anticyclone Merge affects Iraq’s climate clearly through its impact on the different climatic elements. where it appears while they pass through special and distinctive weather . and most of this affection appears in temperatures, Therefore, this research study the relationship between the repetition and the survival period of the Anticyclone Merge and temperature average by using coefficient correlation (Pearson) that shows there’s strong inverse relationship between the integration of Anticyclones and temperatures average.                        &nbs

... Show More
View Publication Preview PDF
Publication Date
Thu Feb 06 2020
Journal Name
Political Sciences Journal
Self-immuniztion: integration of Russian strategic performance a study in the geopolitical orientation circles "of the stage of president putin"n
...Show More Authors

In the period after the collapse of the Soviet Union in 1991, the Federal Republic of Russia witnessed a setback in the overall strategic performance of the country, as it went through a stage of performance flop between the orientation towards Europe in the era of President Boris Yelsen (1991-1999), or the change of direction towards Eurasia, as the Russian Federation managed After President Vladimir Putin assumed power in 2000, from rebuilding the same state and preserving national unity and social cohesion, as well as building a phased military doctrine that made clear moves in Russian strategic thought and future directions towards regions of eternal importance in Russian strategic perception Lack of a set of motivations based on it:

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Mar 01 2023
Journal Name
International Journal Of Research In Social Sciences And Humanities
The Role of Value Chain Analysis as well as Programs and Performance Budget in Reducing Waste of Public Money(Applied Study)
...Show More Authors

Programs and performance budget represents a sophisticated method of public budget numbers, which includes all allocations to be determined for each job or activity within a government entity, which is analyzed according to their needs and costs, and this method can be applied using one of the cost accounting techniques, which is the technique of analyzing the value chain that reduces costs by avoiding activities that do not add value and enhance activities that add value to the economic entity, the current research aims to develop the budget system in government entity by using the budget of programs and performance as a tool for planning and monitoring events and activities, thereby reducing the waste of public money by reducing unnecessa

... Show More
Publication Date
Mon May 25 2026
Journal Name
Journal Of Baghdad College Of Dentistry
The Influence of Different Fabrication Techniques and Preparation Designs on the Marginal Adaptation of Ceramic Veneers (An In vitro Comparative Study)
...Show More Authors

Background: Ceramic veneers represent the treatment of choice in minimally invasive esthetic dentistry; one of the critical factors in their long term success is marginal adaptation. The aim of the present study is to evaluate the marginal gap of ceramic veneers by using two different fabrication techniques and two different designs of preparation. Material and methods: A typodont maxillary central incisor used in the preparation from which metal dies were fabricated, which were in turn used to make forty stone dies. The dies divided into four experimental groups, each group had ten samples: A1: prepared with butt-joint incisal reduction and restored with IPS e.max CAD, A2: prepared with overlapped incisal reduction and restored with IPS e.

... Show More
View Publication Preview PDF
Publication Date
Fri Sep 30 2022
Journal Name
College Of Islamic Sciences
Sfaxi's guidance to alqira'at in "Ghaith al-Nafe fi alqira'at alsabe" From Surat Al-An'am to the end of Surat Hud
...Show More Authors

The research deals with the collection of Allamah Ali al-Nuri’s guidance on readings, which he included in his book (Ghaith al-Naf’ fi al-Qira’at al-Sabe) and singled out it in a separate study, commenting on what needs to be commented and a statement of his guidance, and it consists of an introduction, and three chapters, the first: for the translation of Allamah Sfaxi, and the second: To define the science of guidance, its origins and authorship, and the third: to mention the readings that Al-Safaqi drew from Surat Al-An’am to the end of Surat Hud, followed by the conclusion of the research, then the index of sources and references, and I followed the inductive-analytical method in the research.

Among his most important

... Show More
View Publication Preview PDF