|
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. |
The Islamic nation accuses these days of cruelty and extremism, and this is not strange. Every nation comes out
Including the hardline and the extremist, but the self-pity is that these charges have become
It went beyond the example and the mercy of the gift that the Almighty said (and you are to create great)
Al-Qalam: 4, and accusing him of not touching him in dealing with the people of the book and others, so try
It is our humble quest to urge our small speeches to clarify the position of Islam and its Prophet (peace and blessings of Allaah be upon him)
And deal with all human beings, and to show the low level of rights that our prophet has proved
Western laws are parts of his administration and adopted in the field
This study focused on two areas in AL-Najaf city, AL-Ruhbah and Al-Haydariyah regions because of the importance and widespread use of groundwater in these areas. The two areas were compared quantitatively and qualitatively. For the quantitative approach, the GMS software was used in conjunction with the GIS software to simulate the groundwater flow behavior. The solid model for both areas was created, the geological formation was determined, and the hydraulic properties were identified using GMS software. To test the quantity of groundwater in both areas, the wells have been redistributed to a distance of 2000 m between them, and a period of 1000 days was chosen. When a discharge of 10 l/s and operation times of 4, 8, an
... Show MoreAddressed the problem of the research is marked: (Performing processors for the time between Impressionism and superrealism) the concept of time and how to submit artwork. The search came in four sections: general framework for research and identified the research problem and the need for him. With an indication of the importance of his presence. Then determine the research objectives of (detection processors performing to the concept of time in works of art in each of Impressionism and superrealism. And a comparison between them to reveal similarities and differences), followed by the establishment of boundaries Find three (objectivity, the temporal and spatial) were then determine the terms related to the title. Then provide the theore
... Show MoreThe Prophet Muhammed () is distinguished in the history of mankind by the fact that he came with a law that combined these two opposing sides, reality and ideals, a wonderful and amazing collection, and he created a wonderful composition between them, and they used together a wise comprehension to ensure the treatment of its ills, and the reform of their delusions together, and uses both Both of them are in the necessary position of the needs of life, and the contradictions and separation of this collection and the wise harness in this research from his law, may God bless him and grant him peace, which shows us this balance in the system of Islam, the most sincere representation, where it is one of the honors of morality, good appreci
... Show MoreThe research aims to identify the impact of the merger of the companies affiliated to the Ministry of Industry and Minerals on their financial profitability since the companies before the merger suffered a rise in losses and the deficit reached very high levels that affected its overall performance and even on the morale of workers as losses are increasing and solutions Efficiency is absent. The problem stems from knowing the impact of the merger on the profitability ratios of the companies. The research field was represented by the companies affiliated to the Ministry of Industry and Minerals (21) companies, while the research sample reached (6) companies after the merger (14) companies before the merger, was based on data The f
... Show MoreThis work aims to introduce the concepts of left and right derivations in an AT-algebra and discuss some interesting theorems of these concepts. Also, a fuzzy derivation of an AT-subalgebra, a fuzzy right (left) derivation ideal, a fuzzy derivation of AT-subalgebra, and a fuzzy right (left) derivation ideal are studied. Finally, a level derivation of AT-algebras is defined and some propositions are achieved.
Electrocardiogram (ECG) is an important physiological signal for cardiac disease diagnosis. With the increasing use of modern electrocardiogram monitoring devices that generate vast amount of data requiring huge storage capacity. In order to decrease storage costs or make ECG signals suitable and ready for transmission through common communication channels, the ECG data
volume must be reduced. So an effective data compression method is required. This paper presents an efficient technique for the compression of ECG signals. In this technique, different transforms have been used to compress the ECG signals. At first, a 1-D ECG data was segmented and aligned to a 2-D data array, then 2-D mixed transform was implemented to compress the
When embankment is constructed on very soft soil, special construction methods are adopted. One of the techniques is a piled embankment. Piled (stone columns) embankments provide an economic and effective solution to the problem of constructing embankments over soft soils. This method can reduce settlements, construction time and cost. Stone columns provide an effective improvement method for soft soils under light structures such as rail or road embankments. The present work investigates the behavior of the embankment models resting on soft soil reinforced with stone columns. Model tests were performed with different spacing distances between stone columns and two lengths to diameter ratios of the stone columns, in addition to different
... Show MoreThe rise of online platforms has transformed the discourse landscape, enabling users to create and share content actively, thereby shaping public perceptions and societal narratives. Understanding the dynamics of this discourse is essential for comprehending its socio-political implications. This review aims to provide a comprehensive overview of Critical Discourse Analysis (CDA) concerning online platforms, exploring how language is utilized across various digital contexts to influence identity formation and social inequalities. Methodologically, the review systematically searches electronic databases, including Google Scholar and ProQuest, using keywords related to CDA and online platforms. A total of 30 relevant studies are purpo
... Show MoreThe typical test for diagnosis of severe acute respiratory syndrome coronavirus 2 is a reverse transcription-polymerase chain reaction (RT-PCR) technique, but the chest CT scan might play a complementary role at the first detection of Coronavirus Disease 2019 (COVID-19) pneumonia. Objectives: To determine the sensitivity of CT scan on patients with COVID-19 in Al-Najaf, Iraq, and to compare the accuracy of CT scan with that of RT-PCR technique. Material and Method: This is a prospective study. The patients suspicious of having COVID-19 infection and respiratory symptoms were registered. All patients were diagnosed by RT-PCR and chest CT. Diagnostic performance of CT was intended using RT-PCR as the reference sta
... Show More