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Natural-Convection Phenomenon from a Finned Heated Vertical Tube: Experimental Analysis

       In this work, an experimental analysis is made to predict the thermal performance of the natural-convection phenomenon from a heated vertical externally finned-tube to surrounding air through an open-ended enclosure. Two different configurations of longitudinal rectangular fin namely, continuous and interrupted are utilized with constant thickness, different numbers, and different heights are extended radially on the outer surface of a heated tube. The tube is heated electrically from inner surface with five varied power input magnitudes. The effect of fins configuration, fins number, fins height, and heat flux of the inner tube surface on the thermal performance of natural convection have been studied and analyzed experimentally. Obtained results show that the tube with twelve interrupted longitudinal fins gives the best natural-convection thermal performance in terms of average Nusselt number, about 20% greater than that for the tube with continuous fins. Experimental correlations to predict the average Nusselt number for the heated tubes with continuous and interrupted longitudinal fins are proposed. The present data are compared to previous study and good convergence is noticed.

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Publication Date
Fri Feb 18 2022
Journal Name
Journal Of Engineering And Sustainable Development
CONJUGATE NATURAL CONVECTION IN A POROUS ENCLOSURE SANDWICHED BY FINITE WALLS AND SUBJECTED TO CONVECTION COOLING CONDITION

Steady conjugate natural convection heat transfers in a two-dimensional enclosure filled with fluid saturated porous medium is studied numerically. The two vertical boundaries of the enclosure are kept isothermally at same temperature, the horizontal upper wall is adiabatic, and the horizontal lower wall is partially heated. The Darcy extended Brinkman Forcheimer model is used as the momentum equation and Ansys Fluent software is utilized to solve the governing equations. Rayleigh number (1.38 ≤ Ra ≤ 2.32), Darcy number (3.9 * 10-8), the ratio of conjugate wall thickness to its height (0.025 ≤ W ≤ 0.1), heater length to the bottom wall ratio (1/4 ≤  ≤ 3/4) and inclination angle (0°, 30° and 60°) are the main consid

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Publication Date
Wed Feb 20 2019
Journal Name
Political Sciences Journal
The phenomenon of military governments in the Arab countries

The modern nation state, by virtue of its institutional nature, is divided into political and non-political institutions according to their respective jurisdictions. It is natural for non-political institutions to perform their functions under the control of the political establishment, for two reasons: first, Second: Ensuring the achievement of cooperation, harmony and integration between these different institutions in serving the stability of the society and its continuity and achieving its supreme objectives. The location of the military establishment is part of the non-political institutions of the state, since it carries out a non-political function that is based on defending the homeland against any threats that may threaten its s

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Publication Date
Fri Jun 29 2018
Journal Name
Journal Of Engineering
The Effect of Circular Perforation on a V-Corrugated Fin Performance under Natural Convection

An experimental investigation has been made to study the influence of using v-corrugated aluminum fin on heat transfer coefficient and heat dissipation in a heat sink. The geometry of fin is changed to investigate their performance. 27 circular perforations with 1 cm diameter were made. The holes designed into two ways, inline arrangement and staggered in the corrugated edges arrangement. The experiments were done in enclosure space under natural convection. Three different voltages supplied to the heat sink to study their effects on the fins performance. All the studied cases are compared with v-corrugated smooth solid fin. Each experiment was repeated two times to reduce the error and the data recorded after reaching t

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Publication Date
Sun Mar 28 2021
Journal Name
Journal Of The College Of Education For Women
The Role of Social Work in Reducing the Phenomenon of Fanaticism: حسن فاضل جواد

The present study is concerned with the concept of ethics academically. It aims to investigate the major problems that contemporary Iraqi society suffers from; on top of which is the problem of sectarian and religious intolerance. Such a problem has a major role in the emergence of extremism and terrorism. It further destabilizes the security and stability of the country, exposing, as a result, the lives of citizens to the danger of genocide, disintegrating the social structure, stopping the wheel of development, rampant corruption, and deteriorating the political, social, moral and economic situation. Here comes the role of social work as governmental institutions and civil society organizations in curbing this reprehensible phenomenon

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Publication Date
Tue Dec 28 2021
Journal Name
College Of Islamic Sciences
The concept of the phenomenon of nuns: an analytical ideological study

ملخص البحث باللغة الإنجليزية

The concept of the phenomenon of nuns: an analytical ideological study

Dr. Samia bint Yassin Al-Badri

Department of Islamic Doctrine & Contemporary Ideologies

College of Shariʿah & Islamic Studies

Qassim University

 

The study of concepts is one of the main pillars of doctrinal studies, in order to understand the formation of the concept, and to understand its contexts in religious sources, in order to be systematically criticized; So, this research came with the title:

The concept of the phenomenon of nuns, an analytical doctrinal study

The study concluded with resu

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Publication Date
Wed Apr 01 2015
Journal Name
Journal Of Economics And Administrative Sciences
Identifying the Phenomenon of monopoly according to the vision of Accounting

The research seeks to identify the factors affecting the monopoly and the possibility of measuring the phenomenon of economic ( monopolistic profit) accounted for and that the importance of research topic arising from the transformation of the majority of developing countries to the market economy, which represents the image of the capitalist economy, which is a monopoly, a stages that economy in its various forms, whether Market Worldwide sales monopoly or monopoly, which generates absolute monopolistic profits, which more or less affect on the overall economy of those countries than they should study the phenomenon of monopoly and its impact on the economies of those countries that still love to find her site reinforces its pos

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Publication Date
Sun Jun 30 2019
Journal Name
Journal Of Engineering
Energy, Exergy and Anergy Analysis of Vertical Split Air Conditioner Under experimental ON-OFF Cycling

A time series analysis can help to observe the behavior of the system and specify the system faults. In addition, it also helps to explain the various energy flows in the system and further aid in reducing the thermodynamic losses. The intelligent supervisory LabVIEW software can monitor the incoming data from the system by using Arduino microcontroller and calculates the important parameters. Energy, exergy, and anergy analysis present in this paper to investigate the system performance as well as its components. To accomplish this, a 4-ton vertical split air conditioner based on vapor compression refrigeration cycle charged with refrigerant R-22 was modified for experimental analysis. The results showed that during 540

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Publication Date
Sun Sep 01 2013
Journal Name
Journal Of Economics And Administrative Sciences
Sustainable Tourism development and its contribution in facing unemployment phenomenon

Tourism is a human phenomenon and economic and social activity. It represents an effective forces in the life of the individuals and state alike. As any other economic and human activity has appositive and negative results.

So there is a necessary to planning and activate this sector to get the most possible advantage.

Tourism  has special importance out of its effect on the structure  and performance of national economy. It can be regarded a dynamic activity with mutual effect include all the economic activities within and out the state. Tourism is affected and affect the  production con summing , joineries , communication , ports ,hotel , restaurants ,internal and

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Publication Date
Tue Jul 01 2014
Journal Name
Journal Of The Faculty Of Medicine Baghdad
The incidence of hypoxemia due to malposition of double lumen endotracheal tube during one lung ventilation

Background: Oxygenation during one lung ventilation (OLV) can be affected by positioning of Double lumen endobronchial tube (DLT). Mal position can occurs following intubation and moving the patient to the lateral decubitus position.

Objectives: To study the relation of hypoxemia to mal position of double lumen endo bronchial  tube after patient positioning in lateral decubitus position and during one lung ventilation. The use of fiber-optic

Fac Med Baghdad

2014; Vol.56, No.2

Received: Jan., 2014

Accepted March. 2014

 

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Publication Date
Mon Dec 31 2012
Journal Name
Al-khwarizmi Engineering Journal
The Effect of Doppler Phenomenon on the Speed of Blood Flow

This research studying the phenomenon of Doppler (frequency Doppler) as a method through which the direction and speed of the blood cells flows in blood vessels wear measured. This Doppler frequency is relied upon in medicine for measuring the speed of blood flow, because the blood flow is an important concept from the concepts of medicine. It represents the function and efficient of the heart and blood vessels in the body so any defect in this function will appear as a change in the speed of blood flow from the normal value assumed. As this speed changes alot in cases of  disease and morbidity  of the heart, so in order to identify the effect of changing the Doppler frequency on the speed of blood flow and the relationship of

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