Nanocomposite films of silver-polyvinyl alcohol (Ag/PVA) with varying silver nanoparticle concentrations (1-5 wt%) were synthesized via a solution casting technique. The films were characterized by understanding the influence of Ag content on their structural, optical, mechanical, and electrical properties. UV-Vis spectroscopy (300-800 nm) revealed a red shift in absorption peaks and a significant decrease in the optical band gap from 5.39 eV to 1.06 eV with increasing Ag concentration, indicating the formation of additional energy states within the PVA matrix. FTIR and SEM analyses confirmed the successful incorporation of nanoparticles and revealed changes in surface functionalities and morphology. Mechanically, the nanocomposites exhibited enhanced tensile strength, elongation at break, Young’s modulus, and hardness, attributed to a strong interfacial network between the Ag nanoparticles and the PVA chains. The incorporation of Ag also imparted antibacterial properties and increased hydrophobicity. Electrically, the material showed a dramatic improvement in conductivity, achieving a value of 1.5×10⁵ S/cm with just 3 wt% Ag. Furthermore, AC conductivity increased with frequency and Ag content (from 5.8×10⁻⁹ to 1.01×10⁻⁴ S/cm), while the dielectric constant decreased from 0.95 to 0.25 at 1000 kHz, confirming the role of Ag in facilitating charge transport. These findings demonstrate the great potential of Ag/PVA nanocomposites for use in flexible electronics.
The synthesis and characterization of Schiff base and the complexities of metal ions and the evaluation of its antioxidant activities against 1.1-Diphenyl-2-picrylhydrazyl (DPPH) will compared with standard natural antioxidants and ascorbic acid. These prepared materials gave results are due exhibit excellent radical scavenging activities for all complexes with new prepared from reaction Schiff base and metal ions for [ Mn(II), Zn (II), Cd(II), Pd(II) and Hg(II) ]. The complexes prepared characterization by spectral methods (ultraviolet visible, infrared and mass spectra) will be identified in addition to the element micro analysis, (F.A.A.), magnetic sensitivity. The molar conductance values indicated that the complexes derived from Mn(II)
... Show MoreBackground: Propolis has received great interest because of its wide range antimicrobial activity. Propolis also called (bee glue) due to its collection by (Apismellifera) honeybees from various plants resinous substance. The aim of this study was to determine the antibacterial effect of propolis extracts (aqueous and alcoholic) on anaerobic periodontal pathogen namely Aggregatibacteractinomycetemcomitans. Materials and Methods: Strains of Aggregatibacter actinomycetemcomitans wasisolated from pockets of systemically healthy patients aged between 35-55 years old suffering from chronic periodontitis with pocket depths of 5-6 mm, the bacteria cultured on special blood Agar plates solid media. Propolis was extracted by using water and alcohol.
... Show MoreThe present work presents design and implementation of an automated two-axis solar tracking system using local materials with minimum cost, light weight and reliable structure. The tracking system consists of two parts, mechanical units (fixed and moving parts) and control units (four LDR sensors and Arduino UNO microcontroller to control two DC servomotors). The tracking system was fitted and assembled together with a parabolic trough solar concentrator (PTSC) system to move it according to information come from the sensors so as to keep the PTSC always perpendicular to sun rays. The experimental tests have been done on the PTSC system to investigate its thermal performance in two cases, with tracking system (case 1) and without trackin
... Show MoreBy using governing differential equation and the Rayleigh-Ritz method of minimizing the total potential energy of a thermoelastic structural system of isotropic thermoelastic thin plates, thermal buckling equations were established for rectangular plate with different fixing edge conditions and with different aspect ratio. The strain energy stored in a plate element due to bending, mid-plane thermal force and thermal bending was obtained. Three types of thermal distribution have been considered these are: uniform temperature, linear distribution and non-linear thermal distribution across thickness. It is observed that the buckling strength enhanced considerably by additional clamping of edges. Also, the thermal buckling temperatures and
... Show MoreMany of the proposed methods introduce the perforated fin with the straight direction to improve the thermal performance of the heat sink. The innovative form of the perforated fin (with inclination angles) was considered. Present rectangular pin fins consist of elliptical perforations with two models and two cases. The signum function is used for modeling the opposite and the mutable approach of the heat transfer area. To find the general solution, the degenerate hypergeometric equation was used as a new derivative method and then solved by Kummer's series. Two validation methods (previous work and Ansys 16.0‐Steady State Thermal) are considered. The strong agreement of the validation results (0.3
The paper present design of a control structure that enables integration of a Kinematic neural controller for trajectory tracking of a nonholonomic differential two wheeled mobile robot, then proposes a Kinematic neural controller to direct a National Instrument mobile robot (NI Mobile Robot). The controller is to make the actual velocity of the wheeled mobile robot close the required velocity by guarantees that the trajectory tracking mean squire error converges at minimum tracking error. The proposed tracking control system consists of two layers; The first layer is a multi-layer perceptron neural network system that controls the mobile robot to track the required path , The second layer is an optimization layer ,which is impleme
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