Multifunctional Applications of a Novel Ru-Metal Mixed PVAL Flexible Composite for Limiting Absorption and Varistor: Synthesis, Optical, and Electrical Characterization

Synthesis, structural characterization, and antimicrobial evaluation of new mononuclear mixed ligand complexes based on furfural-type imine ligand, and 2,2'-bipyridine

The present investigation goal was to investigate the chemistry of four new mononuclear mixed ligand Fe(III), Co(II), Cu(II), and Cd(II) complexes constructed from furfural-type imine ligand (L), and the co ligand 2,2'-bipyridine in addition to assessing their antimicrobial activity against some bacterial, and fungi strains. The structure of the complexes was interpreted by different spectroscopic techniques such as MS, IR, ¹H NMR, UV-Vis, elemental analysis, TG-DTG, conductivity, and magnetic susceptibility measurements. The correlation of all results revealed that ligand (L) acts as a neutral ONNO tetradentate whereas the co ligand acts as a neutral NN bidentate. The coordination of the ligands with the metal ions in a molar ratio of 1:1:1 leads to formation of an octahedral geometry around the metal ions. The octahedral geometry has been validated and optimized by DFT analysis. Conductivity data showed the electrolytic nature of all complexes. The thermal stability of all complexes was deduced in addition to evaluating some thermodynamic, and kinetic parameters using Coats-Redfern method. Furthermore, all complexes in comparison to their parent ligands were tested for their biological potency against some pathogenic bacterial, and fungi strains using the paper disk diffusion method. [CdL(bpy)](NO₃)₂ complex revealed the highest antimicrobial activity.

Preparation of Discontinuous Cu/SiO2 Multilayers-AC Conduction and Determining the Measurement Uncertainty

This paper presents a test stand for testing alternating current electrical parameters of Cu-SiO₂ multilayer nanocomposite structures obtained by the dual-source non-reactive magnetron sputtering method (resistance, capacitance, phase shift angle, and dielectric loss angle tangent δ). In order to confirm the dielectric nature of the test structure, measurements in the temperature range from room temperature to 373 K were carried out. The alternating current frequencies in which the measurements were made ranged from 4 Hz to 7.92 MHz. To improve the implementation of measurement processes, a program was written to control the impedance meter in the MATLAB environment. Structural studies by SEM were conducted to determine the effect of annealing on multilayer nanocomposite structures. Based on the static analysis of the 4-point method of measurements, the standard uncertainty of type A was determined, and taking into account the manufacturer's recommendations regarding the technical specification, the measurement uncertainty of type B.