Preferred Language
Articles
/
alkej-502
Free Convection in an Inclined Concentric Annular Square Cavities Filled With Porous Medium and Heated By Non-Uniform Temperature
...Show More Authors

A numerical study of the two-dimensional steady free convection flow in an inclined annulus between two concentric square cavities filled with a porous medium is presented in this paper for the case when the side outer walls are kept with differentially heated temperature while the horizontal outer walls and the inner walls are insulated. The heated wall is assumed to have spatial sinusoidal temperature variation about a constant mean value. The Darcy model is used and the fluid is assumed to be a standard Boussinesq fluid. For the Cartesian coordinate system, the governing equations which were used in stream function form are discretized by using the finite difference method with successive under – relaxation method (SUR) and are solved by Gauss-Siedel iterative method. The upwind scheme was used for the transport terms in the energy conservation equation. The results are presented to demonstrate the streamlines, the isotherms, and the Nusselt number depending on the Rayleigh number ranging from (Ra =10 to 1000), dimension ratio from (Dr = 0.15 to 0.45), and the inclination angle from (= 0o to 45o). Also the effects of the amplitude (=0 to 1) and the wave number (f =0 to 5) of the heated side wall temperature variation on the free convection are investigated. The results show the effect of previous parameters (Ra, Dr,, , and f) on the flow fields and temperature profiles. It also show that the average Nusselt number is a strong function of the Rayleigh number, inclination angle, dimension ratio, and temperature variation. The peak value of the average Nusselt number based on the hot wall temperature is observed to occur at dimension ratio of (0.15), inclination angle of (40.1°), amplitude and wave  number (1 & 0.75) for Rayleigh number of (1000).

View Publication Preview PDF
Quick Preview PDF
Publication Date
Sun Apr 17 2016
Journal Name
Al-academy
Expressionism in painting contemporary in Iraq Study features formalism: عبد الرزاق جبار رحيل الكناني
...Show More Authors

In the present research is marked (expressive drawing in contemporary Iraq, the study of morphological features) eating expressive as the direction of modern art in the drawing for the period before and after World Wars I and II. And follow the tracks. And in research and investigation about the origins and sources and characteristics of expressionist painting at adult patrons and art gatherings, and the extent of their impact in the drawing for contemporary Iraqi sixties and seventies generation (generation of professors) and down to the younger generation in the eighties of the last century. Over the nearly two decades of history of fine movement in Iraq, a period specified in the search within the limits of temporal boundaries, and by

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Apr 11 2023
Journal Name
Indonesian Journal Of Chemistry
Synthesis of Co (ll), Ni (ll), Cu (ll), Pd (ll), and Pt (lV) Complexes with 14, 15, 34, 35-Tetrahydro-11 H, 31 H-4, 8-diaza-1,3 (3,4)-ditriazola-2,6 (1,4)-dibenzenacyclooctaphane-4,7-dien-15, 35-dithione, and the Thermal Stability of Polyvinyl Chloride Modified Complexes
...Show More Authors

In the current endeavor, a new Schiff base of 14,15,34,35-tetrahydro-11H,31H-4,8-diaza-1,3(3,4)-ditriazola-2,6(1,4)-dibenzenacyclooctaphane-4,7-dien-15,35-dithione was synthesized. The new symmetrical Schiff base (Q) was employed as a ligand to produce new complexes comprising Co(II), Ni(II), Cu(II), Pd(II), and Pt(II) metal-ions at a ratio of 2:1 (Metal:ligand). There have been new ligands and their complexes validated by (FTIR), (UV-visible), 1H-NMR, 13C-NMR, CHNS, and FAA spectroscopy, Thermogravimetric analysis (TG), Molar conductivity, and Magnetic susceptibility. The photostabilization technique to enhance the polymer was also used. The ligand Q and its complexes were mixed in 0.5% w/w of polyvinyl chloride in tetrahydrofuran

... Show More
View Publication Preview PDF
Publication Date
Wed Oct 01 2014
Journal Name
Journal Of Economics And Administrative Sciences
knowledge strategic abilities And impact in the building of competitive advantage Field research the views of a sample of the administrative leaders of the Iraqi private banks
...Show More Authors

The research synthesis variables of competitive advantage and the mechanism achieved by focusing on knowledge abilities and strategic of the administrative leadership, and governments and the developed countries took the racing frantically and my destiny to invest more money and resources to development of wealth and human knowledge is so choice investment winner always and who Aaikhyee never, because God Almighty give humans the abilities of all other creatures and that these abilities varying from person to person, there is the problem of search provoking questions about the essence of what it's about research and both sides theoretical and field, the objective of this research

... Show More
View Publication Preview PDF
Crossref (2)
Crossref
Publication Date
Sun Jan 01 2023
Journal Name
مجلة ميسان للدراسات الأكاديمية
Bond Strength Of 3D Printed Acrylic Resin With Silicone Soft Liner After Ethyl Acetate Surface Treatment:, A Review Of Literature
...Show More Authors

View Publication
Crossref
Publication Date
Thu Mar 05 2026
Journal Name
Journal Of Baghdad College Of Dentistry
Photogrammetric analysis of facial soft tissue profile of Iraqi adults sample with Class I normal occlusion: (A cross sectional study)
...Show More Authors

Background: The purposes of this study were to determine the photogrammetric soft tissue facial profile measurements for Iraqi adults sample with class I normal occlusion using Standardized photographic techniques and to verify the existence of possible gender differences. Materials and methods: Eighty Iraqi adult subjects (40 males and 40 females) with an age ranged between 18-25 years having class I normal occlusion were chosen for this study. Each individual was subjected to clinical examination and digital standardized right side photographic records were taken in the natural head position which is mirror position which the patient looking straight into his eyes into the mirror mounted on the stand. The photographs were analyzed using A

... Show More
View Publication Preview PDF
Publication Date
Fri May 01 2020
Journal Name
Applied Thermal Engineering
Thermal performance of a flat-plate solar collector using aqueous colloidal dispersions of graphene nanoplatelets with different specific surface areas
...Show More Authors

The effects of using aqueous nanofluids containing covalently functionalized graphene nanoplatelets with triethanolamine (TEA-GNPs) as novel working fluids on the thermal performance of a flat-plate solar collector (FPSC) have been investigated. Water-based nanofluids with weight concentrations of 0.025%, 0.05%, 0.075%, and 0.1% of TEA-GNPs with specific surface areas of 300, 500, and 750 m2/g were prepared. An experimental setup was designed and built and a simulation program using MATLAB was developed. Experimental tests were performed using inlet fluid temperatures of 30, 40, and 50 °C; flow rates of 0.6, 1.0, and 1.4 kg/min; and heat flux intensities of 600, 800, and 1000 W/m2. The FPSC’s efficiency increased as the flow rate and hea

... Show More
Crossref (43)
Crossref
Publication Date
Tue Dec 01 2009
Journal Name
Journal Of Engineering
EFFECT OF ZRO2 , WO3 ADDITIVES ON CATALYTIC PERFORMANCE OF PT/HY ZEOLITE COMPARED WITH PT/ΓAL2O3 FOR IRAQI NAPHTHA TRANSFORMATION
...Show More Authors

Light naphtha treatment was achieved over 0.3wt%Pt loaded-alumina, HY-zeolite and Zr/W/HY-zeolite catalysts at temperature rang of 240-370°C, hydrogen to hydrocarbon mole ratio of 1-4 0.75-3 wt/wt/hr, liquid hourly space velocity (LHSV) and at atmospheric pressure. The hydroconversion of light naphtha over Pt loaded catalyst shows two main reactions; hydrocracking and hydroisomerization reactions. The catalytic conversion of a light naphtha is greatly influenced by reaction temperature, LHSV, and catalyst function. Naphtha transformation (hyroisomerization, cracking and aromatization) increases with decreasing LHSV and increasing temperature except hydroisomerization activity increases with increasing of temperature till 300°C then began

... Show More
Publication Date
Thu Jul 01 2010
Journal Name
Bulletin Of The Iraq Natural History Museum (p-issn: 1017-8678 , E-issn: 2311-9799)
NEW SUB-SPECIES OF CHUKAR PARTRIDGE ALECTORIS CHUKAR (GRAY 1830) (PHASIANIDAE, GALLIFORMES) FROM NORTH EAST OF IRAQ WITH BIOLOGICAL OBSERVATIONS
...Show More Authors

Chukar partridge Alectoris chukar (Gray, 1830) is the only species of the 46 species of the genus Alectoris to be found in Iraq. At least there are fourteen subspecies of chukar were described from east Europe, the Middle East and west Asia, two of them were known to be found in Iraq, A.c. Kurdestanica (Meinertzhagen, 1923) from Alpine bio-geographical zone of altitude more than 2000m high, and A.c. werae Zarundny and Loudon, 1904, from the foothills of altitude not more than 400m. In between these two regions, there is another bio-geographical region known as the Irano-toranian zone 400-2000m high. Using morphological, ecological, behavioural, reproduction and hybridization criteria this study discove

... Show More
View Publication Preview PDF
Publication Date
Sun Dec 06 2009
Journal Name
Baghdad Science Journal
Study of properties of electrical conductivity of Tin dioxide thin films treated with Xenon impulse radiation used as Gas sensors
...Show More Authors

During of Experimental result of this work , we found that the change of electrical conductivity proprieties of tin dioxide with the change of gas concentration at temperatures 260oC and 360oC after treatment by photons rays have similar character after treatment isothermally. We found that intensive short duration impulse annealing during the fractions of a second leads to crystallization of the films and to the high values of its gas sensitivity.

View Publication Preview PDF
Crossref
Publication Date
Thu Apr 02 2020
Journal Name
Indian Journal Of Forensic Medicine & Toxicology
New Record of the Species Synthesiomyia Nudiseta (van der Wulp, 1883) (Diptera, Muscidae) with Forensic Study from Kerbala City, Iraq
...Show More Authors