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Natural convection in an annular space provided with metal foam fins attached to the inner cylinder is studied numerically. The metal foam fins made of copper were inserted in different axial sections with three fins in each section. The temperature of the inner cylinder is kept constant while the annular outer surface is adiabatic. The thickness effect of the inner pipe wall was considered. Naiver Stokes equation with Boussinesq approximation is used for the fluid regime while Brinkman-Forchheimer Darcy model is used for metal foam. In addition, the local thermal non-equilibrium condition in the energy equation of the porous media is presumed. The effect of Rayleigh number and number of foam fins in the axial direction, on fluid flow and heat transfer characteristics, were examined. The current model was valid with the available published results and good agreement is noticed. Results showed that as the Rayleigh number increases the dominated of convection mode increases and average Nusselt increases. It was found that at Rayleigh of 106 Nusselt reached its higher value which is 4.6 for the case of adding seven axial metal foams. A comparison between adding foam fins and copper fins was established for a range of Rayleigh numbers between 104 and 106. It showed a good enhancement in Nusselt number and the greatest enhancement percentage was 45.9% at Rayleigh equal 106 for the case of using seven sections of foam fins. |
This study showed the basic features of corporate tax in Iraq by showing what was in the Income Tax Law in force .The study aims of this to indicate the role of tax corprates in tax revenue and then the possibility of strengthening the revenue of this tax as an important source of local funding sources in the form that is with him reduce dependence on oil revenues to finance the general budget in Iraq, the risks and the study found a number of conclusions from the most important: that the corporate tax comes in the introduction to the components of the income tax structure in terms of relative importance and formed a revenue source of prime The gross proceeds of the income tax in Iraq, where it contributed to more than a quarter of that
... Show MoreThis study aimed at revealing the degree of availability of standards of word problems in mathematics books for the first three grades of the basic stage in Palestine. For this purpose, the researcher prepared an analysis tool and a list of criteria consisting of two areas: linguistic formulation and mathematical content. Every area had seven items. The results of the study showed that the third-grade mathematics book has the highest degree of availability of the standards with 85.75%, and then came the second-grade mathematics book with 83.12%. Finally, the first-grade mathematics book came with 80.13%. In the light of the previous results, the researcher recommended to develop the language of word problems, to take into account their i
... Show MoreThe research aims to monitor the methods of Counter psychological warfare in the Iraqi press during the operations to liberate Mosul from the control of the terrorist organization ISIS.The research used the survey method, and “Tareek Al Shaab” Newspaper as a research sample, chosen according to the systematic random sample.
The research reached the following results:
1- The Communicator’s relied on the contents of the counter-psychological warfare and its methods in the battle of “Qadimun Ya Naynawa” used in the newspaper. The methods used were labels assigning such as : inevitable victory, prodding and morale, consensus, breaking of opposition morale, stereotyping, demonization of the opponent
Three ligands were prepared, spectroscopic method and elemental analysis verified their structures. The L1 and L2 ligands are flavylium salts while the third one L3 is a Flavon. The reactions between transition metal salts and the ligands have synthesized two groups of new metal complexes, one group contains L1, L3 coordinated with the metal ion. The other group contains L2, L3 and the metal. These complexes have been identified by available spectroscopic tools (UV-Visible and IR), the C.H.N results confirmed the proposed structures. The experimental data disclosed that the complexes were coordinated by 6the coordinate with mono-and bidentate ligands forming octahedral structure, in which L3 acts as monodentate and L1, L2 as bidentate ligan
... Show MoreIn this work the fabrication and characterization of poly(3-hexylthiophene) P3HT-metallic nanoparticles (Ag, Al). Pulsed Laser Ablation (PLA) technique was used to synthesis the nanoparticles in liquid. The Fourier Transformer Infrared (FTIR) for all samples indicate the chemical interaction between the polymer and the nanoparticles. Scanning Electron Microscopic (SEM) analysis showed the particle size for P3HT-AgNps samples between 44.50 nanometers as well the spherical structure. While for P3HT-AlNps samples was flakes shape. Energy Dispersive X-ray (EDX) spectra show the existing of amount of metallic nanoparticles.
Abstract As the United Nations approaches its 70th anniversary, the world is going through the most severe accumulation of serious international security failures in recent memory, challenging the UN Security Council’s ability to address them effectively. Over the past four years, crises in Libya, Syria and Ukraine have precipitated a worrisome erosion of great power relations that has complicated Security Council decision making on a number of trouble spots. Its inability to devise consensus responses to the escalating civil war in Syria has been particularly troubling, resulting in the regional spill over into Iraq and the emergence of Islamic State as a new threat to peace in the region and beyond. Meanwhile, the UN’s often under
... Show MoreAutorías: Nuha Mohsin Dhahi, Muhammad Hamza Shihab. Localización: Revista iberoamericana de psicología del ejercicio y el deporte. Nº. 6, 2022. Artículo de Revista en Dialnet.
In "historical" fiction, characters that never really existed, give expression to the impact of historical events on the people who really did live through them. The result is not history, as an accurate record of actual events, but fiction in which an earlier age is rendered through the personal joys and sufferings of characters. This paper
aims at investigating the historical realities presented in Dickens’s A Tale of Two Cities.
Isolation and identification fungi of Emericella nidulans and Aspergillus flavus from a pinkish and yellowish artificial clay, by using potato dextrose agar (PDA). Results revealed that E. nidulans was the best for degrading anthracene (92.3%) with maximum biomass production (3.7gm/l), compared to A. flavus with the rate of degradation (89%) and biomass production of (1.2gm/l), when methylene blue was used as redox indicator after incubating in a shaker incubator 120rpm at 30Co for 8days. Results indicated that E. nidulans has a high ability of anthracene degradation with the rate of (84%), while A. flavus showed the lower level with (77%) by using HPLC.