By using vacuum evaporation, thin films of the (CdS)0.75-(PbS)0.25 alloy have been deposited to form a nanocrystalline composite. Investigations were made into the morphology, electrical, optical and I-V characteristics of (CdS)0.75-(PbS)0.25 films asdeposited and after annealing at various temperatures. According to AFM measurements, the values of grain sizes rise as annealing temperatures rise, showing that the films' crystallinity has been increased through heat treatment. In addition, heat treatment results in an increase in surface roughness values, suggesting rougher films that could be employed in more applications. The prepared films have direct energy band gaps, and these band gaps increase with the increase in the degrees of annealing temperature. Additionally, Urbach energy values decrease with an increase in annealing temperature degrees, indicating a reduction in the tail defects and an enhancement in crystal structure through annealing. The produced films' conductivity raise when temperature in the range (RT-473)K increased, demonstrating that they are semiconducting films. At comparatively lower temperature degrees, the conduction is caused by carriers that are stimulated into localized states at the band edges. At relatively higher temperatures, the conductivity appears to be substantially temperature-dependent. As a result, the conduction mechanism results from carriers being excited into extended states beyond mobility edges. The photovoltaic measurement (I–V) properties, open circuit voltage, short circuit current, efficiency and fill factor of (CdS)0.75-(PbS)0.25 heterostructure cells have been examined under 100mW/cm2 . Interestingly, rising annealing had enhanced photovoltaic cell performances; the solar cell had shown its highest efficiency (0.42%) at 573K. From XRD the structures are polycrystalline with cubic and hexagonal structures indicating that there’s a mix of phases of PbS and CdS, the grain size and intensity raise with annealing temperatures.
Background: The aim of this study was to evaluate the effect of three types of light curing devices QTH, LED and Flashmax on the surface microhardness of three types of bulkfill composite resins; Filtek Bulkfill posterior composite ( 3M), Tetric Evo Ceram ( Ivoclar Vivadent) and Sonicfill composite ( Kerr) Materials and methods: Total number of 90 samples was prepared, 30 samples for each type of bulkfill composite, were divided into three main groups, group A: Filtek posterior bulkfil (3M), group B: Tetric Evo Ceram (Ivoclar Vivadent) and group C: contain Sonicfill composite (kerr). Which then divided into three subgroups (n= 10) (1) Samples cured by QTH system (2) Samples cured by LED system and (3) samples cured by Flashmax system the
... Show MoreA particulate polymer composite material was prepared by reinforcing with the Aluminum Oxide (Al2O3) or Aluminum (Al) metallic particles with a particle size of (30) µm to an unsaturated Polyester Resin with a weight fraction of (5%, 10%, 15%, 20%).
Tensile test results showed the maximum value of elastic modulus reached (2400MPa.) in the case of reinforcing with (Al) particles with weight fraction (20%) and (1500 MPa.) in the case of reinforcing with (Al2O3) particles of the same weight fraction.
When the impact and the flexural strength tests were done, the results showed that flexural strength (F.S), maximum shear stress (τmax), impact strength
... Show MoreThe first studies on shocks and vibrations were carried out at the beginning of the 1930s to improve the behavior of buildings during earthquakes. Vibration tests on aircraft were developed from 1940 to verify the resistance of parts and equipments prior to their first use. Flutter is a well-known example of dynamic aero elasticity, where when oscillation of structure interacted with unsteady aerodynamic forces the flutter will occur. Vibration on any structure without damping means that self-harmonic oscillation will occur, and in most cases the oscillation may start to increase until structural failure. This behavior is very similar to resonance phenomena if only the oscillation is being studied as a vibration case. In vibration suppre
... Show MoreThis research, the author deals with a number of topics, including: What is interpretation?, the difference between exegesis and I interpretation of the Quran, the meaning of interpretation in the term, and the meaning of interpretation in the terminology of the people of interpretation, It deals with then, he demonstrates the interpretation and reasoning meanings of language, and the need of Muslims to interpret the Quran, and limitations of the use of interpretation and exegesis, On the interpretation of opinion and when it began, and the need of Muslims to explain, Finally he discusses the ways of interpretation, and the conditions to be provided in the interpreter.
Several new derivatives of 1, 2, 4-triazoles linked to phthalimide moiety were synthesized through following multisteps. The first step involved preparation of 2, 2-diphthalimidyl ethanoic acid [2] via reaction of two moles of phthalimide with dichloroacetic acid. Treatment of the resulted imide with ethanol in the second step afforded 2, 2-diphthalimidyl ester [3] which inturn was introduced in reaction with hydrazine hydrate in the third step, producing the corresponding hydrazide derivative [4]. The synthesized hydazide was introduced in different synthetic paths including treatment with carbon disulfide in alkaline solution then with hydrazine hydrate to afford the new 1, 2, 4-triazole [10]. Reaction of compound [10] with different alde
... Show MoreCopper (I) complex containing folic acid ligand was prepared and characterized on the basis of metal analyses, UV-VIS, FTIR spectroscopies and magnetic susceptibility. The density functional theory (DFT) as molecular modeling calculations was used to determine the donor atoms of folic acid ligand which appear clearly at oxygen atoms binding to hydrogen. Detection of donation sights is supported by theoretical parameters such as geometry, mulliken population, mulliken charge and HOMO-LUMO gap obtained by DFT calculations.
Five membered heterocyclics derivatives were synthesized in this work by three routes. The first route includes the synthesis of N-benzoic acid 1,2,3,-triazole derivatives (3),(4) by diazotation of methyl-2-amino benzoate and treating the resulted salt (1) with sodium azide and ethyl acetoacetate or acetyl acetone, respectively. In the second route, derivatives of pyrazole (8) pyrazolin-5-one (9), (10) were prepared by the reaction of the salt (1) with some active methylene compounds to give the corresponding hydrazones derivatives (5-7) which then they were treated with hydrazine hydrate. The third route afforded the synthesis of three derivatives (12), (15a), (15b) of thiazolidinone by two different methods. AII compounds were confirmed b
... Show MoreThe need for wireless sensing technology has rapidly increased recently, specifically the usage of electromagnetic waves which becoming more required as a source of information. Silicon carbide (SiC) Nano particles has been used in this study, the material under test (MUT) was exposed directly to a microwave field to examine the electromagnetic behavior. The permittivity and permeability were investigated with different filler materials to approach best and optimal electromagnetic absorbing characteristics to assist engineers to monitor structure-based composite for defects evaluation that may occur during operation conditions or through manufacturing process. XRD, FESEM and both complex permittivity and permeability were measured f
... Show MoreNew 2-amino thiazole ,oxodiazole, sulphonilamide and diazin derivatives of N-(α-chloro aceto)-3-(tolyl imino)-5-bromo-2-oxo-indole(2) have been synthesized .The preparation process started by the reaction of 5-bromo isatin with P-toluidine in the presence of glacial acetic acid and dimethylformamide(DMF) as a solvent to give 3-(tolyl imino)5-bromo-1H-indole-2-one.(1), Compound (1) with sodium hydride in dimethylformamide(DMF) at 0C0 gave a suspension of the sodium salt of Schiff base derivative and subsequent reaction with monochloroacetylchloride obtained the intermediate compound(2).Compound(2) was reacted with different reagents in four routes.The first route involved direct reaction with substituted 2-aminobenzothiazole u
... Show More