다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

Fundamentals, processes and applications of high-permittivity polymer–matrix composites

Study of flexible nanodielectric materials (FNDMs) with high permittivity is one of the most active academic research areas in advanced functional materials. FNDMs with excellent dielectric properties are demonstrated to show great promise as energy-storage dielectric layers in high-performance capacitors. These materials, in common, consist of nanoscale particles dispersed into a flexible polymer matrix so that both the physical/chemical characteristics of the nanoparticles and the interaction between the nanoparticles and the polymers have crucial effects on the microstructures and final properties. This review first outlines the crucial issues in the nanodielectric field and then focuses on recent remarkable research developments in the fabrication of FNDMs with special constitutents, molecular structures, and microstructures. Possible reasons for several persistent issues are analyzed and the general strategies to realize FNDMs with excellent integral properties are summarized. The review further highlights some exciting examples of these FNDMs for power-energy-storage applications.

Flexible Nanodielectric Materials with High Permittivity for Power Energy Storage

Synthesis methods for nanosized hydroxyapatite with diverse structures.

Magnetocaloric effect: From materials research to refrigeration devices

In this paper we present the impedance spectroscopy of ternary solid solutions of BiFeO3, TbFeO3 and PbTiO3, prepared by solid-state reaction method. The preliminary structural studies were carried out by x-ray diffraction technique, showing the formation of polycrystalline sample with ABO3 type of perovskite structure with hexagonal symmetry for Bi0.8Tb0.1Pb0.1Fe0.9Ti0.1O3system at room temperature. Dielectric and impedance study of this ceramic has been characterized in the temperature range 175 - 325 0C and frequency range 100 Hz - 1 MHz. The maximum ferroelectric transition temperature (Tc) of this system was in the range 210 - 225 0C with the dielectric constant having maximum value ~2480 at 1 kHz. The complex impedance graph exhibited one impedance semicircle arc at all reported temperatures, which indicates that the impedance response is a Cole-Cole type relaxation. Single semicircle indicate that the grain effect of the bulk in ceramic. The bulk resistance of the material decreases with increasing temperature showing negative temperature showing a typical semiconducting property, i.e. negative temperature coefficient of resistance (NTCR) behavior.

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Impedance and Modulus Spectroscopy Characterization of Tb modified Bi0.8A0.1Pb0.1Fe0.9Ti0.1O3 Ceramics

Electromagnetic and thermal history during microwave heating

Superparamagnetic MnFe2O4 dispersed over graphitic carbon sand composite and bentonite as magnetically recoverable photocatalyst for antibiotic mineralization

M.A. Valente

Papers

Impedance and Modulus Spectroscopy Characterization of Tb modified Bi0.8A0.1Pb0.1Fe0.9Ti0.1O3 Ceramics

Electromagnetic and thermal history during microwave heating

Superparamagnetic MnFe2O4 dispersed over graphitic carbon sand composite and bentonite as magnetically recoverable photocatalyst for antibiotic mineralization

Nb2O5 nanosize powders prepared by sol–gel – Structure, morphology and dielectric properties

Structural characterization, magnetic, magnetocaloric properties and phenomenological model in manganite La0.75 Sr0.1Ca0.15 MnO3 compound