An experimental and numerical study was 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 and for annulus inclination angle of (δ = 0˚, 30˚, 60˚ and 90˚). The numerical study was to give the governing equation under assumptions that used Darcy law and Boussinesq’s approximation and then it was solved numerically using finite difference approximation. It was found that the average Nusselt number depends on (Ra*, Hf, δ and Rr ). The results showed that the increasing of the fin length increases the heat transfer rate for any fin 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 comparison was made between the results of the present work and those of other researches for the case without fins and excellent agreement was obtained.
يتناول هذا البحث شخصية عراقية مهمة كان لها أثر كبير في تاريخ العراق المعاصر ، وهو الشيخ جلال الحنفي البغدادي ، الذي يعد مثالاً يحتذى به في الوسطية والتعايش والفكر التنويري، والتجديد . يعد الشيخ جلال الحنفي من أهم المؤلفين الموسوعيين العراقيين المعاصرين ، إن لم يكن أهمهم على الاطلاق ، واختص بجوانب متعددة من المعرفة والثقافة، وكان مثالاً للشخصية البغدادية الأصيلة ، حتى أنه أفنى عمره في توثيق التراث والثقا
... Show MoreBACKGROUND: Color Vision Deficiency (CVD) is mostly an inherited trait and is not an uncommon problem. Prevalence of CVD differs among different ethnic and geographic properties of the population that affect their genetic constitution. Ishihara plates remain an internationally accepted tool for screening red-green CVD. OBJECTIVE: To determine the prevalence of red-green CVD among adult males from Baghdad province. PATIENTS AND METHODS: One thousand and five (1005) adult males were enrolled in this study, using a systematic sampling technique, and were screened for CVD utilizing 24-plate Ishihara plates and re-tested by EnChroma 39-Color plates. All males were residing in Baghdad and the center of Iraq. RESULTS: Among all tested males, 948 r
... Show MoreIn this study, phosphorescence analysis (KPA) is used for determining soil collected from the Tigris River from Al- Karrada and Bab Al-Sharq in Baghdad and samples were taken from rainwater collected from Al-Rashad, Al-Obeidi, Al-Dora and Al-Sadr City in Baghdad. The measurements were carried out by the Iraqi Ministry of Health and Environment, in the Radiation Protection Center. The collection, removal and evaporation of the samples ranged from January to the end of March 2018. The results show the presents of concentration of 238U and 235U in soil samples and the rainwater samples. The conclusion of this work is the concentration of uranium in soil samples is more than recommendations by ICRP value of 1.9 μg /l. While all water sample
... Show MoreMedia is one of the main and effective factors; and it is a tool of crisis management equipment. Media is one of the most dangerous, effective and decisive weapons in modern conflicts; a tool for making events and influencing their events and trends as a means of reporting as the enormous capabilities of media which help media to move very quickly, and cross borders; and overcome obstacles, through many means of audio, reading and visual. As its ability, moreover, to influence the psychological and intellectual control of communities, and behaviors.
Intelligent media is, then, used in crises management and coverage. Crises have been existed with the presence of man on Earth. Thei
... Show MoreThis study presents a linguistic analysis of how Russian and American mainstream media and official statements deployed speech acts of accusation during the 2022 Russian invasion of Ukraine. Using Speech Act Theory (Austin, 1962; Searle, 1976) as the framework. The study analyzes 50 texts of English-language official statements and media headlines from both sides. In this research utterances are categorized into assertives, expressives, directives, commissives, and declarations, and analyzes their pragmatic force in shaping narratives. The analysis reveals contrasts in tone and rhetorical strategy: U.S. officials and media overwhelmingly use assertive accusations and expressive condemnations to morally indict Russia, while Russian counterpa
... Show More: translating acronyms of media and international (& world) organizations helps the researcher to draw the following conclusions:1- Acronyms of world news agencies can be translated into Arabic in three ways: by indicating the lexical meaning; by indicating English abbreviated form as letter by letter & by indicating Arabic abbreviated form as a word. 2- Acronyms of world satellite TV's can be translated into Arabic in two ways: by indicating the lexical meaning & by indicating English abbreviated form as letter by letter. 3- Acronyms of world newspapers can be translated into Arabic in two ways: by indicating both the lexical meaning & Arabic transliteration of the English form. 4- Acronyms of U.N. & world organizati
... Show MoreThe most famous phenomena in the media administration, is the transfer of power, from the decision-makers inside the administration, especially those who occupy administrative positions by law, to those who enjoy a natural influence based on knowledge, skill and competence, especially on the psychological, political and social sides.
The old way of dividing the administration into heads and hands is no longer accepted, and the separation of thinking and work based on a traditional format has become rather refused.
Also, a chapter like this one might become a constant routine, but it doesn’t keep pace with the development of field concepts and practices of administrations. The logic of modern administration emphasizes th
... Show MoreThis study aimed to study the inhibition activity of purified bacteriocin produced from the local isolation Lactococcuslactis ssp. lactis against pathogenic bacteria species isolated from clinical samples in some hospitals Baghdad city. Screening of L. lactis ssp. Lactis and isolated from the intestines fish and raw milk was performed in well diffusion method. The results showed that L. lactis ssp. lactis (Lc4) was the most efficient isolate in producing the bacteriocin as well observed inhibitory activity the increased that companied with the concentration, the concentration of the twice filtrate was better in obtaining higher inhibition diameters compared to the one-fold concentration. The concentrate
... Show MoreThe current work concerns preparing cobalt manganese ferrite (Co0.2Mn0.8Fe2O4) and decorating it with polyaniline (PAni) for supercapacitor applications. The X-ray diffraction findings (XRD) manifested a broad peak of PAni and a cubic structure of cobalt manganese ferrite with crystal sizes between 21 nm. The pictures were taken with a field emission scanning electron microscope (FE-SEM), which evidenced that the PAni has nanofibers (NFs) structures, grain size 33 – 55 nm, according to the method of preparation, where the hydrothermal method was used. The magnetic measurements (VSM) that were conducted at room temperature showed that the samples had definite magnetic properties. Additionally, it was noted that the saturation magnetizatio
... Show MorePurpose: The purpose of this study was to clarify the basic dimensions, which seeks to indestructible scenarios practices within the organization, as a final result from the use of this philosophy.
Methodology: The methodology that focuses adoption researchers to study survey of major literature that dealt with this subject in order to provide a conceptual theoretical conception of scenarios theory .
The most prominent findings: The only successful formulation of scenarios, when you reach the decision-maker's mind wa takes aim to form a correct mental models, which appear in the expansion of Perception managers, and adopted as the basis of the decisions taken. The strength l
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