Ferrite with the general formula CuLayFe2-yO4 (where y=0.02, 0.04, 0.06, 0.08 and 0.1), were prepared by standard ceramic technique. The main cubic spinel structure phase for all samples was confirmed by x-ray diffraction patterns with the appearance of small amount of secondary phases. The lattice parameter results were 8.285-8.348 Å. X-ray density increased with La addition and showed values between 5.5826 – 5.7461gm/cm3. The Atomic Force Microscopy (AFM) showed that the average grain size was decreasing with the increase in La concentration. The Hall coefficient was found to be positive. It demonstrates that the majority of charge carriers of p-type, suggesting that the mechanism of conduction is predominantly caused by hopping of holes. The resistivity was noticed to increase with the increase in La substitution. The activation energy Eav decreased with the frequency increase. The AC conductivity was found to increase with the frequency and La addition. Dielectric constant was noticed to decrease with frequency and La addition. The dielectric loss factor decreased with La content because rare earths are known as low dielectric loss materials. |
The superconductor compound (YBa2Cu2.8Zn0.2O7+δ) is prepared by solid state reaction (SSR), Sol-gel (SG) and laser Pulse deposition (PLD) methods. We used the X-ray diffraction technique, which shows an orthorhombic crystalline system for all the samples, and increase in the high-phase (Y-123) and decrease in low-phase and vary in proportion according to the method of preparation with the emergence of some impurities. The behavior of the samples in terms of electrical resistance and critical temperature was investigated all samples showed superconducting behavior. The properties of the dielectric (real dielectric constant, imaginary dielectric constant, loss tangent, alternating electrical conductivity) were s
... Show MoreThe aim of this work is studying the binary system ??'??? Ni?)with two ratios (y=36,80) by using casting method for preparing the samples.Magnetic and Mechanical properties have been studidt different httrea^nttem^rature.All the alloys were found a ferromagnetic behavior and sensitive to the heat treatment. Best properties were found at the heat treatment 1100 C°.A significant different results were found above 1100C° for lower magnetic and mechanical values. This is possibly due to the change on the degree of magnetic moment orders, in which most of the moments are started to remove from coupled ferromagnetically.?
Many faces are exposed to degradation, discoloration, changes in humidity. The primary objective has improved some properties of hybrid nanocomposites materials that used for restoring of the function maxillofacial prosthesis and improving the esthetic. In the present research different lengths chopped and continuous of ultrahigh molecular weight polyethylene (UHMWPE) fiber was added at selected percentage (0.0, 0.2% and 1%) to polymer blend composite (95%SR /5%PMMA: 0.2% Pomegranate Peels Powder (PPP)) for developing the properties of silicone rubber used for the maxillofacial prosthesis applications. Some mechanical and physical properties were done on the all prepared samples. The results showed that all properties have improved when add
... Show MoreIn this study three inorganic nano additives, namely; CaCO3, Al2O3 and SiO2 were used to prepare nanocomposites of unsaturated polyester in order to modify their mechanical properties, i.e. tensile strength, elongation, impact and hardness. The results indicated that all the three additives were effective to improve the mechanical properties up to 4% by weight. The effectiveness of them follows the order : CaCO3 > Al2O3 > SiO2 This is due to their particle size in which CaCO3 (13nm), Al2O3 (20-30nm) and SiO2 (15-20nm).
Given the paucity and toxicity of available drugs for leishmaniasis, coupled with the advent of drug resistance, the discovery of new therapies for this neglected tropical disease is recognised as being of the utmost urgency. As such antimicrobial peptides (AMPs) have been proposed as promising compounds against the causative Leishmania species, insect vector-borne protozoan parasites. Here the AMP temporins A, B and 1Sa have been synthesised and screened for activity against Leishmania mexicana insect stage promastigotes and mammalian stage amastigotes, a significant cause of human cutaneous disease. In contrast to previous studies with other species the activity of these AMPs against L. mexicana amastigotes was low. This suggests that ama
... Show MoreThe importance of specifying proper aggregate grading for achieving satisfactory performance in pavement applications has long been recognized. To improve the specifications for superior performance, there is a need to understand how differences in aggregate gradations within the acceptable limits may affect unbound aggregate base behavior. The effects of gradation on strength, modulus, and deformation characteristics of high-quality crushed rock base materials are described here. Two crushed rock types commonly used in constructing heavy-duty granular base layers in the State of Victoria, Australia, with three different gradations each were used in this study. The gradations used represent the lower, medium, and upper gradation li
... Show MoreIn the current study, the definition of mapping of fuzzy neutrosophic generalized semi-continuous and fuzzy neutrosophic alpha has generalized mapping as continuous. The study confirmed some theorems regarding such a concept. In the following, it has been found relationships among fuzzy neutrosophic alpha generalized mapping as continuous, fuzzy neutrosophic mapping as continuous, fuzzy neutrosophic alpha mapping as continuous, fuzzy neutrosophic generalized semi mapping as continuous, fuzzy neutrosophic pre mapping as continuous and fuzzy neutrosophic γ mapping as continuous.
In this study, experimental mortar combinations with 1% micro steel fibers, were examined to create geopolymer mortars. To test the effect of the fibers on the mortar's resistance, the geopolymer mortar was designed with various proportions of more environmentally friendly materials fly ash and slag. The percentage of fly ash by weight was 50, 60, and 70% of the slag. The best results were obtained when a 50:50 ratio of fly ash and slag were mixed with 1% micro steel fibers. The results showed that the mixtures containing fibers performed better in the considered tests (toughness index, ductility index, and resilience index). In the impact resistance test, the mixture contained 50% fly ash by weight of the slag with a temperature of
... Show MoreIn this study, composite materials were prepared using unsaturated polyester resin as binder with two types of fillers (sawdust and chopped reeds). The molding method is used to prepare sheets of UPE / sawdust composite and UPE / chopped reeds composite. The mechanical properties were studied including flexural strength and Young's modulus for the samples at normal conditions (N.C). The Commercial wood, UPE and its composite samples were immersed in water for about 30 days to find the weight gain (Mt%) of water for the samples, also to find the effect of water on their flexural strength and Young's modulus. The results showed that the samples of UPE / chopped reeds composite gained highest values of flexural strength (24.
... Show MoreThis research of using Feldspar in the production self compacting concrete (SCC) ( 5,10,15 )% as partial replacement by weight of cement .In this research some of fresh properties of SCC ( slump flow used V-funnel test and filling ability used ( U- box test ) for concrete mixes and also some of the harden properties of SCC ( compressive and flexural tests ). The research results showed that negative effect of Feldspar on the fresh properties of self compacting concrete but the positive effect of Feldspar on the harden properties of self compacting concrete .