Preferred Language
Articles
/
GxefRo4BVTCNdQwCS0AG
Numerical investigation of natural convection in a square enclosure partially filled with horizontal layers of a porous medium
...Show More Authors
Abstract<p>Two‐dimensional buoyancy‐induced flow and heat transfer inside a square enclosure partially occupied by copper metallic foam subjected to a symmetric side cooling and constant heat flux bottom heating was tested numerically. Finite Element Method was employed to solve the governing partial differential equations of the flow field and the Local Thermal Equilibrium model was used for the energy equation. The system boundaries were defined as lower heated wall by constant heat flux, cooled lateral walls, and insulated top wall. The three parameters elected to conduct the study are heater length (7 ≤ <italic>ζ</italic> ≤ 20 cm), constant heat flux (150 ≤ <italic>q</italic>″ ≤ 600 W m<sup>−</sup><sup>2</sup>), and porous material thickness (5 ≤ <italic>H</italic> ≤ 20 cm). The porous material used was the copper metal foam of porosity = 0.9 and pore density PPI = 10, and saturated with a fluid of Prandtl number = 0.7. On the basis of the results obtained, it was concluded that at the porous layer thickness = 5 cm, the rate of heat transferred was (74.6%) higher than when the layer height was 20 cm (the cavity is fully filled) and at the same thickness it was found that the heat rate is (51.4%) higher than when using the half filling (<italic>H</italic> = 10 cm). Further, the local and mean Nusselt number is maximum when using the largest heater size and smallest porous layer thickness. Finally, better circulation and convective modes were observed at high values of heat flux.</p>
Scopus Clarivate Crossref
View Publication
Publication Date
Sun Apr 01 2012
Journal Name
2012 International Conference On Future Communication Networks
Efficient method to find the multiplicative inverse in GF (2&lt;sup&gt;m&lt;/sup&gt;) using FPGA by exponentiation to (2&lt;sup&gt;k&lt;/sup&gt;)
...Show More Authors

Multiplicative inverse in GF (2 m ) is a complex step in some important application such as Elliptic Curve Cryptography (ECC) and other applications. It operates by multiplying and squaring operation depending on the number of bits (m) in the field GF (2 m ). In this paper, a fast method is suggested to find inversion in GF (2 m ) using FPGA by reducing the number of multiplication operations in the Fermat's Theorem and transferring the squaring into a fast method to find exponentiation to (2 k ). In the proposed algorithm, the multiplicative inverse in GF(2 m ) is achieved by number of multiplications depending on log 2 (m) and each exponentiation is operates in a single clock cycle by generating a reduction matrix for high power of two ex

... Show More
View Publication
Scopus (1)
Crossref (1)
Scopus Crossref
Publication Date
Wed Dec 12 2018
Journal Name
Iop Conference Series: Materials Science And Engineering
The performance of MnO<sub>2</sub>/graphite electrode for TOC removal from wastewater by indirect electrochemical oxidation process
...Show More Authors

Electrochemical oxidation in the presence of sodium chloride used for removal of phenol and any other organic by products formed during the electrolysis by using MnO2/graphite electrode. The performance of the electrode was evaluated in terms fraction of phenol and the formed organic by products removed during the electrolysis process. The results showed that the electrochemical oxidation process was very effective in the removal of phenol and the other organics, where the removal percentage of phenol was 97.33%, and the final value of TOC was 6.985 ppm after 4 hours and by using a speed of rotation of the MnO2 electrode equal to 200 rpm.

View Publication Preview PDF
Scopus (6)
Crossref (3)
Scopus Clarivate Crossref
Publication Date
Thu Mar 30 2023
Journal Name
College Of Islamic Sciences
Title: Arabic Manuscript, Concepts and Terms and Their Impact on Determining Its Historical beginnings and extension of its existence.
...Show More Authors

Title: Arabic Manuscript, Concepts and Terms and Their Impact on Determining Its Historical beginnings and extension of its existence.

Researcher: Dr. Atallah Madb Hammadi Zubaie.

Bn the name of Allah Most Merciful

The interest in manuscripts and rules  of their investigation and dissemination appeared soon, and the speech in editing terms and concepts appeared in sooner time.  When looking at the classified books  in the Arab manuscripts , we find the books of the first generation  did not allude definition for this term  , but rather  focused on  the importance of manuscripts and their  existence locations, indexing, care, and verification rules. The  reason for this is that the science of Arabic manuscrip

... Show More
View Publication Preview PDF
Publication Date
Sun Dec 30 2018
Journal Name
Baghdad Science Journal
Adsorption and Kinetic Study of Methylene Blue dye on New Surface Derived from Copolymer (Melamine – Formaldehyde – Para- methyl Anisole)
...Show More Authors

A new copolymer (MFA) was prepared from condensation of melamine (M) with p- methyl – anisole (A) in the presence of condensation agent like 37% (w/v) of formaldehyde. The new copolymer was characterized by elemental, IR and HNMR spectra. The chelating ion-exchange property of this polymer was studied for methylene blue dye in aqueous solution in 100-200ppm concentrations. The adsorption study was carried out over a wide range of pH, shaking time and in media of various kinetic parameters models. Thermal parameters like enthalpy, entropy and Gibbs free energy of adsorption process of methylene blue on surface of MFA resin were determined on the basis of kinetic parameters at different temperatures. To describe the equilibrium of adsorp

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Dec 01 2009
Journal Name
Journal Of Economics And Administrative Sciences
Evaluation The Efficiency And Effectiveness of The Iraq stock Exchange -An Empirical Study From July 2004 to March 2008–
...Show More Authors

 The aim of this study was to provide an overall assessment to the efficiency of the Iraq stocks exchanges (ISE) through specifying well –known models .First, Fama's efficient market hypothesis as a contrary concept to the random walk hypothesis, was performed and it has been found that ISE follows the random process, so the price of the shares can't be predicated on the basis of past information. Second,we use a multifactor model, which so named multiple regression, to explore the link between ISE  and the main economic indicators. our empirical analysis finds that every weak associations exists between major ISE measures and main economic indicators.

View Publication Preview PDF
Crossref
Publication Date
Mon May 01 2023
Journal Name
International Journal Of Supply And Operations Management
How has covid-19 affected the logistics of Europe, Asia and Africa, and do appropriate solutions differ between countries?
...Show More Authors

View Publication
Scopus (4)
Scopus
Publication Date
Wed Jun 15 2022
Journal Name
Journal Of Baghdad College Of Dentistry
Surface Characterization of PEKK Modified by stron-tium –hydroxyapatite coating as implant material Via the magnetron sputtering Deposition technique
...Show More Authors

Background: The best material for dental implants is polyetherketoneketone (PEKK). However, this substance is neither osteoinductive nor osteoconductive, preventing direct bone apposition. Modifying the PEKK with bioactive elements like strontium hydroxyapatite is one method to overcome this (Sr-HA). Due to the technique's capacity to provide better control over the coating's properties, RF magnetron sputtering has been found to be a particularly useful technique for deposition. Materials and methods : With specific sputtering conditions, the RF magnetron technique was employed to provide a homogeneous and thin coating on Polyetherketoneketone substrates.. the coatings were characterized by Contact angle, adhesion test, X-ray

... Show More
Crossref (10)
Crossref
Publication Date
Thu Jul 03 2008
Journal Name
مجلة التقني المجلد الحادي والعشرون العدد3
THE EFFECT OF ULTRA VIOLET, SOME AMINO ACIDS AND VITAMINS ON THE SUSCEPTIBILITY TO SOME ANTIBIOTICS AGAINST STAPHYLOCOCCUS AUREUS
...Show More Authors

Abstract: This research was performed to study the effect of some amino acids and vitamins on the growth of bacteria Staphylococcus aureas and its sensitivity against UV light. The results showed low inhibition in bacterial growth because amino acids repairs the damges caused by UV light. Besides the effect of two groups of antibiotics (β-lactame and tetracycline) on the growth of S. aureus and the possible interference of amino acids and vitamins in the activity of the antibiotics against this bacteria in the presence of UV light were studied. The result show increase in the sensitivity towards these antibiotics and provided protection against the antibiotics.

Publication Date
Sun Oct 23 2016
Journal Name
Oriental Journal Of Chemistry
Synthesis and Antioxidant Ability of Some 4-(((4-(5-(Aryl)-1,3,4-Oxadiazol-2-Yl)Benzyl)Oxy)Methyl)-2,6-Dimethoxyphenol
...Show More Authors

A series of new 4-(((4-(5-(Aryl)-1,3,4-oxadiazol-2-yl)benzyl)oxy)methyl)-2,6-dimethoxy phenol (6a-i) were synthesized from cyclization of 4-(((4-hydroxy-3,5-dimethoxy benzyl)oxy)methyl)benzohydrazide with substituted carboxylic acid in the presences of phosphorusoxy chloride.The resulting compounds were characterized by IR, 1H-NMR, 13C-NMR, and HRMS data. 2,2-Diphenyl-1-picrylhydrazide (DPPH) and ferric reducing antioxidant power (FRAP) assays were used to screen their antioxidant properties. Compounds 6i and 6h exhibited significant antioxidant ability in both assay. Furthermore, type of substituent and their position of the aryl attached 1,3,4-oxadiazole ring at position five are play an important roles in enhancing or declining the antio

... Show More
Scopus (6)
Crossref (1)
Scopus Crossref
Publication Date
Sun Mar 04 2018
Journal Name
Baghdad Science Journal
Synthesis, Characterization and Biological Activates Studies of some New Derivatives From 2-aminoo-5-mercapto-1, 3, 4-thiadiazole
...Show More Authors

In this work, thiadiazole derivatives were prepared by taking advantage of active sites in (2-amino-5-mercapto-1, 3, 4-thiadiazole) as a starting material base. The main heterocyclic compounds (1, 3, 4-thiadiazole, oxazole) etc, 2-amino-5-mercapto-1,3,4-thiadiazole compound (1) was prepared by cyclic closure of thiosemicarbazide compound with anhydrous sodium carbonate and carbon disulfide. Oxidation of (1) via hydrogen peroxide, to have (2) which was treated with chloro acetyl chloride to get (3). Preparation of thiazole ring (4) was from reacting of (3) with thiourea. Synthesis of diazonium salts (5) from compound (4) using sodium nitrite and HCl. Compound (5) reacted with different ester compounds to prepare a new azo compounds (6–8).C

... Show More
View Publication Preview PDF
Scopus (4)
Crossref (2)
Scopus Clarivate Crossref