32 resultados para Interagency Council on Meeting the Housing and Service Needs of Seniors (U.S.)
Resumo:
Nickel nanocomposites were prepared by incorporating nickel nanoparticles in a neoprene matrix according to a specific recipe for various loadings of nickel particles. The dielectric properties of these composites were evaluated for different frequencies ranging from 100 kHz to 8MHz at different temperatures from 30 ◦C to 120 ◦C. The dielectric permittivity increases with increase of nickel concentration. Increase in temperature enhances the permittivity initially, till 40 ◦C and thereafter the permittivity decreases. The dielectric loss exhibits relaxation peaks and the peaks shift to lower frequencies with increase in volume fraction of the nickel nanoparticles in the matrix. The evaluation of magnetic and dielectric properties of these composites suggests that the dielectric permittivity can be tailored by an appropriate loading of the filler using semi-empirical equations and the magnetic properties vary according to simple mixture equations
Resumo:
The results of the investigation of the magnetic and structural properties of the alloy system Fe0.75–xSi0.25Sbx, where x = 0, 0.05, 0.1, 0.15, 0.2, and 0.25 synthesized by mechanical alloying followed by heat treatment are described. The x-ray diffraction reveals that all samples crystallize in the DO3-type cubic phase structure. Substituting Fe by Sb led to a de-crease in the lattice constant and the unit cell volume. The magnetic properties are investigated by vibrating sample magnetometer and show that all the samples are ferromagnetically ordered at room temperature. The Curie temperature is found to decrease linearly from (850 ± 5) K for the parent alloy to (620 ± 5) K for the alloyith x = 0.25. The satura-tion magnetizations at room temperature and at 100 K are found to decrease with increasing the antimony concentration. The above results indicate that Sb dissolves in the cubic structure of this alloy system.
