Microwave Absorption Study of Nano Synthesized Strontium Ferrite Particles in X Band
Microwave ferrites require high coercivity for their use as microwave absorbers. Strontium hexaferrite is one of the best material due to its magnetic properties , high coercivity, large unilateral magnetic anisotropy and very low cost in comparison to others make it suitable for the use as microwave components specifically microwave absorber .Strontium nano hexa ferrites were successfully synthesized through chemical co-precipitation method. The synthesized nanostructure was characterized by X-Ray powder diffraction(XRD) and fourier transform infrared spectroscopy (FTIR).The XRD result shows the shift from amorphous to crystalline after the calcination of sample at 600 0 C.The behaviour of ferrite as microwave absorber was also studied for X band of frequencies.
Low-Loss Z-Type Hexaferrite for Microwave Antenna Miniaturization Application
Magnetic and dielectric properties of conventional ceramics processed Ba3Co2Fe24O41 hexaferrite were investigated for microwave antenna miniaturization. Iron deficiency and optimizations of technology conditions have been used to control the high frequency properties of Co2Z materials. The properties of the materials were characterized by SEM, XRD, Vector Network Analyzer, and so on. The experimental results showed that Z-phase was the main phase with traces of Y-phases for all the tested samples and the resonance frequencies were above 2GHz. 3BaO·2CoO·10.4Fe2O3 samples sintered at 1050°C had a loss tanδμ of 0.07 with the permeability of 7.28 at 1GHz and the miniaturization factor n reached a value up to 10 under 2GHz. It was found that Z-type hexaferrites with iron deficiency and low sintering temperatures met the demands of low-loss tanδμ for microwave antenna applications.
Euthanasia — again: “Letting die” is not in the patient's best interests: a case for active euthanasia
Recent discussions in the Journal on the subject of euthanasia have relied on intuitive appeals to distinctions traditionally considered to be morally relevant, such as the distinction between acts and omissions (or killing and letting die), or ordinary and extraordinary means of treatment. These discussions remained inconclusive. However, the question of euthanasia no longer remains inconclusive if one adopts the perspective suggested by the United States President's Commission for the Study of Ethical Problems in Medicine and Biomedical and Behavioral Research and by the World Medical Assembly – that a doctor should act in his or her patient's best interests. From this vantage point, it is argued, there will be instances when active euthanasia is the proper cause of action.