In this work, the structure properties of nano Lead sulfide PbS thin films are studied. Thin samples were prepared by pulse laser deposition and deposited on glass substrates at wavelength 1064nm wavelength with a various laser energies (200,300,400,500)nm. The study of atomic force microscope (AFM) and X-ray diffraction as well as the effect of changing the laser energy on the structural properties has been studied. It has been observed that the membrane formed is of the polycrystalline type and the predominant phase is the plane (111) and (200). The minimum grain size obtained was 16.5 nm at a laser energy about 200 mJ. The results showed that thin films of average granular sizes (75 nm) could be prepared.As for the optical properties, the effect of changing the laser energy on them was studied, and it was found that they have direct allowed transitions in the range of (1.55 to 2.45) eV
Many researchers used different methods in their investigations to enhance the heat transfer coefficient, one of these methods is using porous medium. Heat transfer process inside closed and open cavities filled with a fluid-saturated porous media has a considerable importance in different engineering applications, such as compact heat exchangers, nuclear reactors and solar collectors. So, the present paper comprises a review on natural, forced, and combined convection heat transfer inside a porous cavity with and without driven lid. Most of the researchers on this specific subject studied the effect of many parameters on the heat transfer and fluid field inside a porous cavity, like the angle of inclination, the presenc
... Show MoreDue to the importance of nanotechnology because of its features and applications in various fields, it has become the focus of attention of the world and researchers. In this study, the concept of nanotechnology and nanomaterials was identified, the most important methods of preparing them, as well as the preparation techniques and the most important devices used in their characterization.
<p> Traditionally, wireless networks and optical fiber Networks are independent of each other. Wireless networks are designed to meet specific service requirements, while dealing with weak physical transmission, and maximize system resources to ensure cost effectiveness and satisfaction for the end user. In optical fiber networks, on the other hand, search efforts instead concentrated on simple low-cost, future-proofness against inheritance and high services and applications through optical transparency. The ultimate goal of providing access to information when needed, was considered significantly. Whatever form it is required, not only increases the requirement sees technology convergence of wireless and optical networks but
... Show MoreCholelithiasis is one of the commonest surgical problems and one of the most common gastrointestinal diseases throughout the world but its pathogenesis remains unclear. Many theories have been proposed forward to explain the mechanism of stone formation. It is not fully clear if symptomatic gallstone disease is associated with a specific pattern of some biochemical abnormalities, as lipid profile and fasting blood sugar in serum of patients.
This study was designed to estimate lipid profile and fasting blood sugar in the sera of patients with cholelithiasis in comparison with normal individuals (control).
In this study, 104(male=16, female=88) were symptomatic gallstone patients (aged 42.79± 12.18 years), and 38(male=6
... Show MoreAbstract
Among the things that have happened and that have emerged from the developments in society is the phenomenon of dairy banks, where institutions collect milk from donating mothers or sellers of milk and benefit from it by sterilizing and selling it.
This topic is considered one of the important topics, as Islam considers breastfeeding as a link as well as parentage, and it has the same genealogy as the spread of sanctity. Therefore, Imamate jurists addressed this topic with research despite its absence in Islamic societies.
The importance of r
... Show MoreThe research problem is to determine the nature of the historical relationship between the profession of social work and volunteer work. Consequently, the research aims to investigate the nature of this relationship from a socio-historical perspective. Three axes have been used to analyze this relationship: the role of voluntary work in the development of the social work as a profession, the efforts made by social work to reach professionism and to distinguish it from voluntary work, and the relationship between social work and voluntary work. The research is qualitative analytical research and adopts the Mixed Methods Research (MMR). It identifies some literature for the analysis and implementation of a scoping process. It represents a
... Show More