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 presence of vibration, magnetic fields, and heat generation. They used different thermal and hydrodynamic boundary conditions, different geometries of cavity, and different saturated-fluids. Results manifested that the fluid and thermal characteristics enhance greatly as porosity increases at a high value of Darcy number. Also, vibrational effects are a dominant factor in the heat transfer process only at high Darcy and Reynolds numbers.
2(2-Tetrahydropyranylthio) methyl cyclopropyl amines were synthesized from allylmercaptan through several steps. The structures of the intermediates and the final products where confirmed through IR, NMR and elemental analysis, these compounds may be of value in the treatment of diseases where free radicals are implicated in their pathogensis, since the thio and the amino groups of the synthesized compounds may act as free radical scavengers.
The synthesis of conducting polyaniline (PANI) nanocomposites containing various concentrations of functionalized single-walled carbon nanotubes (f-SWCNT) were synthesized by in situ polymerization of aniline monomer. The morphological and electrical properties of pure PANI and PANI/SWCNT nanocomposites were examined by using Fourier transform- infrared spectroscopy (FTIR), and Atomic Force Microscopy (AFM) respectively. The FTIR shows the aniline monomers were polymerized on the surface of SWCNTs, depending on the -* electron interaction between aniline monomers and SWCNTs. AFM analysis showed increasing in the roughness with increasing SWCNT content. The AC, DC electrical conductivities of pure PANI and PANI/SWCNT nanocomposite h
... Show MoreThis work involves synthesis of amides containing isoxazoline unit starting with
chalcone; 4-[3-(3‾-nitrophenyl)-2-propene- 1-one]-aniline[I]. 4-Aminoacetophenone was
reacted with 3-nitrobenzaldehyde in basic medium giving chalcone [I] by claisen-schemidt
reaction. The chalcone [I] was reacted with hydroxylamine hydrochloride giving isoxazoline
[II] in NaOH basic medium. The amides with structural formula [III]a-h were prepared by the
reaction of amino compounds ; isoxazoline [II] with different acid chlorides in dry pyridine
and using DMF as a solvent at 4
0
C. All the synthesized compounds have been characterized
by melting points , FTIR and
1
HMNR (of compound [III]a) spectroscopy.
The research sheds light on an important religious sect that played a fundamental role in the structure of the Iraqi society in general and the Baghdadi society in particular, in which the Jews in general and the Jewish women in particular played an active role in the culture and heritage of Baghdadi society. The educational, cultural and artistic activity of Jewish literacy is a model for study.
The main aim of conducting this research is to identify the applications of Smart libraries in the Arab world. The Researcher relied on the documentary and Survey approach to collect information and data through the Internet, and to get to know these libraries. Then the Research came in three sections dealing with the first topic: The general framework of the study. The second topic deals with: introducing Smart libraries and indicating their types and characteristics. The Third topic dealt with the requirements of Smart libraries'application by identifying the basic components of it (Smart building, Smart Librarian , Smart devices, systems and software, Smart information sources,and Smart beneficiaries), and dealt with Smart libraries appl
... Show MoreThe last decade of this 20th century provides a wide spread of applications of one of the computer techniques, which is called Fuzzy Logic. This technique depends mainly on the fuzzy set theory, which is considered as a general domain with respect to the conventional set theory. This paper presents in initiative the fuzzy sets theory and fuzzy logic as a complete mathematics system. Here it was explained the concept of fuzzy set and defined the operations of fuzzy logic. It contains eleven operations beside the other operations which related to fuzzy algebra. Such search is considered as an enhancement for supporting the others waiting search activities in this field.
Epoxy resins were modified by some thermosetting materials using unsaturated polyesters which were cured with styrene , MMA ,and MA . When unsaturated Polyester ( as thermosetting material ) was used , and cured with styrene showed better results than acrylic monomers . Thermal stability rised on modification of epoxy resins with unsaturated polyester . The new formulation had converted the epoxy resin from hard brittle material to hard and tough material .
Thermal analysis were studied using ( DSC ) and physicomechanical characteristics were measured .
In this work, an investigation for the dynamic analysis of thin composite cylindrical and spherical shells is presented. The analytical solution is based upon the higher order shear deformation theory of elastic shells from which the developed equations are derived to deal with orthotropic layers. This will cover the determination of the fundamental natural frequencies and mode shapes for simply supported composites cylindrical and spherical shells.
The analytical results obtained by using the derived equations were confirmed by the finite element technique using the well known Ansys package. The results have shown a good agreement with a maximum percentage of discrepancy, which gives a confidence o
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