The effect of rare-earth oxide CeO2 on the electromagnetic properties of ferrite-ceramic composite materials
In this work, we present the influence of rare-earth element additions on this new composite material. A great improvement of the electromagnetic properties was obtained. The constituent chemicals were mixed in the stoichiometric composition, calcined at 850degC for 2 h and blended with PVA to press into steroidal or disc shaped specimens. These specimens were sintered at 900degC for 2.5 h in air. The complex permeability, capacity and impedance were measured with HP4291B and 4291A instruments, respectively, in the frequency range from 1MHz to 2GHz.
Synthesis and electromagnetic properties of ferroelectric-ferromagnetic composite material
Abstract Ferroelectric–ferromagnetic composite materials which possess both capacitive and inductive properties for suppressing electromagnetic interference (EMI) were synthesized by usual ceramic technology. These composite materials have relatively high dielectric constant ( e r = 70 ) and high relaxation frequency (fr>1.8 GHz). The influences of different composition on the electromagnetic properties of composite materials were investigated. The microstructures of the sintered ceramics were observed and analyzed by SEM. It was found that the average grain size of sintered ceramics was smaller than 5 μm and the densities ranged from 4.9 to 5.3 g/cm3.
Amphotericin B microspheres: A therapeutic approach to minimize toxicity while maintaining antifungal efficacy
Amphotericin B microsphere formulations with and without addition of polyethylene glycol 2000 in cross-linked bovine serum albumin were prepared. Amphotericin B microspheres were characterized for particle size (<5 µm), zeta potential (∼30 mV) and drug interaction by DSC and FTIR and were found to be stable formulations. Drug release profiles for these microspheres revealed that the release was primarily by diffusion. In vitro toxicity as assessed by release of haemoglobin and potassium demonstrated no toxic effect as compared with conventional solution formulation. Antifungal activity in vitro was comparable to solution formulation when tested by broth dilution method.