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.
Quantum dots (QDs) can be defined as nanoparticles (NPs) in which the movement of charge carriers is restricted in all directions. CdTe QDs are one of the most important semiconducting crystals among other various types where it has a direct energy gap of about 1.53 eV. The aim of this study is to exaine the optical and structural properties of the 3MPA capped CdTe QDs. The preparation method was based on the work of Ncapayi et al. for preparing 3MPA CdTe QDs, and hen, the same way was treated as by Ahmed et al. via hydrothermal method by using an autoclave at the same temperature but at a different reaction time. The direct optical energy gap of CdTe QDs is between 2.29 eV and 2.50 eV. The FTIR results confirmed the covalent bonding betwee
... Show MoreThe amount of protein in the serum depends on the balance between the rate of its synthesis, and that of its catabolism or loss. Abnormal metabolism may result from nutritional deficiency, enzyme deficiency, abnormal secretion of hormones, or the actions of drugs and toxins. Renal cancer is the third most common malignancy of the genitourinary system, and accounts for 3% of adult malignancies globally. Total serum proteins were measured in malignant kidney tumor, benign kidney tumors, and non tumoral kidney diseases patient groups, as well as in healthy individuals. A significant decrease (p< 0.001) of total serum protein levels in patients with malignant kidney tumors when compared with those of benign tumors, non tumoral diseases, and hea
... Show MoreThe present researchers are trying to enhance the properties of paper sheet that used widely in many fields such as printing and packaging. The enhancement of paper quality is also possible to preserve paper documents of all kinds, as they are the true record, full of the history, achievements of the human being and the intellectual and cultural of the country. It is possible to improve its physical and mechanical properties and preserve them from damage through the use of some solutions of polymeric adhesives, which act as protective barriers against water and moisture penetration. The paper also has the advantage of porosity, which has been overcome by using three types of polymeric adhesives (Nitro Cellulose, Polyvinyl alcohol acetate, a
... Show MoreObjectives: This Paper is an attempt to evaluate the services provided by the private hospitals
and to identify the strength and weakness in
their performance The results can be utilized in stating conclusion and recommendations to improve
and activate the role of private medical sector in society .
Methodology: A questionnaire has be designed for this purpose and distributed to ( 132 ) beneficiaries
mostly from Baghdad private hospitals .
Results: The paper has come out with many important results . Among These are the following :
* these who benefit from services provided by private hospitals believe that the good performance of
such hospital is not due to the medical services alone but also to scientific aspect
This research deals with the hadiths of intimidation. An analytical study of the serious effects of intimidation in society. Intimidation and intimidation of a Muslim is a serious matter, because of the anxiety, intimidation, and dispossession of others ’rights, but some consider it easy, and others intimidate jokingly or seriously, which may lead to such intimidation to have effects Serious.
For intimidation entails the death of the individual, the disappearance of his mind, or the loss of his money, etc., from here the need was urgent; to show the vision of the prophetic Sunnah in denouncing intimidation, so we had this humble research tagged with (hadiths prohibiting the intimidation of a Muslim in the books The six are an analyt
ABSTRACT
The purpose of this research is to investigate the relationship between organizational ethnography and resonant leadership in the University of Kufa, importance of research includes rare of studies that investigated the relationship between organizational ethnography and resonant leadership. Moreover, it comes as an attempt to reduce or bridge the knowledge gap between the variables of the research. As well as try to put the right foundations and appropriate for industry leaders of various Iraqi organizations aimed at profit or service. Based on the random sampling, 450 questionnaires were distributed to employees at the University of Kufa. Only 392 questionnaires were returned. Out of which 104 questionnaires we
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