An experimental and numerical study has been carried out to investigate the heat transfer by natural convection in a three dimensional annulus enclosure filled with porous media (silica sand) between two inclined concentric cylinders with (and without) annular fins attached to the inner cylinder under steady state condition; The experiments were carried out for a range of modified Rayleigh number (0.2 ≤Ra*≤ 11) and extended to Ra* =500 for numerical study, annulus inclination angle of (δ = 0˚, 30˚, 60˚ and 90˚). The numerical study was to write the governing equation under an assumptions used Darcy law and Boussinesq’s approximation and then solved numerically using finite difference approximation. It was found that the average Nusselt number depends on (Ra*, Hf, δ and Rr) and the maximum value of the local Nusselt number for vertical cylinder is about two times as large as that of the horizontal case. The results showed that, increasing of fin length increases the heat transfer rate for any fins pitch unless the area of the inner cylinder exceeds that of the outer one, then the heat will be stored in the porous media. A correlation for Nu in terms of Ra, Rr and δ, has been developed for inner cylinder. A comparison was made between the results of the present work and with other researches for the case without fins and excellent agreement was obtained and reveals deviation less than 5 % for average Nusselt number.
The effect of ethanol and methanol solvent, and their mixture has been studied on the absorption and fluorescence spectra of laser dye Rhodamine B at concentration of (10-4) Molar at room temperature. The molar absorption coefficient has been determined for mixture which was (3.223) at wave number (18181.8 cm-1), Also the Quantum Efficiency of the two solvents (ethanol and methanol) and their mixture have been calculated ,which was for mixture spectrum (38.94%) and it was larger comparing with other and solvents. The characteristics of spectrum has been determined by calculating (??) of absorption spectrum for the solvents and its mixture at maximum wave number ( ) cm-1 depending on solvent polarity and the transitions between molecular ene
... Show MorePurpose: The research aims to build an integrated knowledge framework for the basic research topic. The spirituality of the workplace is through access to the most important scientific proposals on these topics. In management thought framing, the knowledge within them in a serious attempt is to provide the appropriate answers about the intellectual dilemma of research by diagnosing the nature of the relationship with the influential elements and its historical development . Methodology: The study is relied on the analytical survey method. The research sample targeted (88) managers in the center of the Iraqi Ministry of Health exclusively from the researched senior leaders (general manager, assistant general manager, and head of department),
... Show MoreThis Study Sought to Determine The Relationship and Impact Between The Tax Core Capabilities and Tax Settlement The Study Took Place in The Tax Administration, and Based The Problem Was to Two Hypotheses As Solutions Initial Mocked Content to Explain The Relationship Between The Phenomena, and to Test The Validity of Assumptions And Due To The Fact That The General Authority for Taxes is The Body for The Advancement of The Collection Tax In Iraq Random Sample Was Selected to Represent The Population of The Study, Since The Sample Included 22 Individuals Representing 70% of The Total Community to Study, Represented by The Director General, Agents and Directors of Departments and Branch Managers Managers Working in The General Authority fo
... Show MoreIn the contemporary political history of Iraq, a unique protest broke out on October 1st, 2019. This protest reappeared on October 25th and lasted up to the following weeks making this protest as the most comprehensive and deepest one. It has the possibility of lengthening and the diversification of methods among all the social protesting movements during the century for Iraq. This desperate youth movement presents various images and methods to highlight the image of the protesting movement. The role of the Iraqi woman was clear, which was embodied through the mural paintings expressing her artistic and social role in conveying and expressing the goal of the protest. The aim of the current research is to identify the social artistic implica
... Show MoreMotives for public exposure to specialized sports satellite channels and the gratifications achieved about it - Research presented by (Dr. Dr. Laila Ali Jumaa), Imam Al-Kadhim College (peace be upon him) - Department of Information-2021.
The research aims to know the extent of public exposure to specialized sports satellite channels, and what gratifications are achieved from them, and to reach scientific results that give an accurate description of exposure, motives and gratifications verified by that exposure, and the research objectives are summarized in the following:
- Revealing the habits and patterns of public exposure to specialized sports satelli
Contemporary residential neighborhoods suffer from weak sustainability of urban residential environments as a result of the adoption of inefficient spatial organization at the neighborhood unit level. This resulted negative characteristics which affected the achievement of sustainable development plans for the residential environment that constitute the majority of the urban fabric of cities.
The physical affordances ,within the vocabulary of recent times,overcame the spiritual ones and affected the residential environment. Accordingly,the concept of space changed in contemporary residential areas through the dominance of the physical aspect (mass) on the symbolic aspect (space).The modern technology occupied an important level b
... Show Moreيعد التكرار من الظواهر الاسلوبية التي اتخذت دورها في بناء النص الشعري الحديث ويقوم على جملة من الاختيارات الاسلوبية لمادة دون أخرى ولصياغة لغوية دون سواها ، مما يكشف في النهاية عن سرّ ميل هذا النص الشعري أو ذاك لهذا النمط الاسلوبي دون غيره ، وعلى الرغم من ان التكرار يعد مسألة عامة وشائعة في العمل الأدبي ، فأن الاهتمام بهذا الجانب من المنهج الاسلوبي يأتي من جهة كونه مهيمناً له ايحاءاته ودلال
... Show MoreSubjected Find winged bull Assyrian monetary analysis in order to identify the formative relations in terms of percentages, movement and public swab for being aesthetic values upon which the mechanisms of artistic composition, which did not give researchers artistic interest that affects the status of these sculptures and the like of the achievements of the Iraqi civilization in Assyria.
Resulting analysis to a number of the most important results, the percentages approved in the calculation of the parts to do with all when viewed status horizontal with a realistic formulas while in the case of considering frontally clear for Ras stylized proportions and head size larger in length, a ratio confirmed by previous studies, and
... Show MoreBACKGROUND: Three-dimensional (3D) printing is an evolving technology that has been used recently in a wide spectrum of applications. AIM: The objective is to evaluate the application of 3D printing in various neurosurgical practice. PATIENTS AND METHODS: This pilot study was conducted in the neurosurgical hospital in Baghdad/Iraq between July 2018 and July 2019. An X, Y, and Z printer was used. The working team included neurosurgeons, biomedical engineers, and bio-technicians. The procedure starts with obtaining Magnetic resonance imaging (MRI) or computed tomography (CT) scan in particular protocols. The MRI, and CT or angiography images were imported into a 3D programmer for DICOM images called 3D slice where these files con
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