We present a study on radiation losses in the microwave X band in Al-Cr substituted Y-type hexaferrites, namely Ba2Mg2Alx/2Crx/2Fe12-xO22 （x = 0, 0.5 and 1.0）. The study is performed by means of a vector network ana...We present a study on radiation losses in the microwave X band in Al-Cr substituted Y-type hexaferrites, namely Ba2Mg2Alx/2Crx/2Fe12-xO22 （x = 0, 0.5 and 1.0）. The study is performed by means of a vector network analyzer, Fourier transform infrared spectroscopy, a vibrating sample magnetometer and x-ray powder diffraction. Ba2Mg2Fe12O22 hexaferrite shows radiation loss of -37.25dB （99.999% loss） at frequency 9.81 GHz, which can be attributed to its high value of saturation magnetization, i.e., 22.08emu/g. Moreover, we obtain that magnetic properties have strong influence on the radiation losses.展开更多
The present paper investigates the effects of a vertical magnetic field on the double diffusive nanofluid convection, The effects of the Brownian motion and ther- mophoresis due to the presence of nanoparticles and th...The present paper investigates the effects of a vertical magnetic field on the double diffusive nanofluid convection, The effects of the Brownian motion and ther- mophoresis due to the presence of nanoparticles and the effects of the Dufour and Sorer parameters due to the presence of solute are included in the investigated model. The normal mode technique is used to solve the conservation equations. For the analytical study, valid approximations are made in the complex expression for the Rayleigh number to get useful and interesting results. The bottom heavy binary nanofluids are more stable than the regular binary fluids, while the top heavy binary nanofluids are less stable than the regular binary fluids. The critical wave number and the critical Rayleigh number in- crease whereas the frequency of oscillation （for the bottom heavy configuration） decreases when the Chandrasekhar number increases. The numerical results for the alumina-water nanofiuid are studied by use of the MATHEMATICA software.展开更多
文摘We present a study on radiation losses in the microwave X band in Al-Cr substituted Y-type hexaferrites, namely Ba2Mg2Alx/2Crx/2Fe12-xO22 （x = 0, 0.5 and 1.0）. The study is performed by means of a vector network analyzer, Fourier transform infrared spectroscopy, a vibrating sample magnetometer and x-ray powder diffraction. Ba2Mg2Fe12O22 hexaferrite shows radiation loss of -37.25dB （99.999% loss） at frequency 9.81 GHz, which can be attributed to its high value of saturation magnetization, i.e., 22.08emu/g. Moreover, we obtain that magnetic properties have strong influence on the radiation losses.
文摘The present paper investigates the effects of a vertical magnetic field on the double diffusive nanofluid convection, The effects of the Brownian motion and ther- mophoresis due to the presence of nanoparticles and the effects of the Dufour and Sorer parameters due to the presence of solute are included in the investigated model. The normal mode technique is used to solve the conservation equations. For the analytical study, valid approximations are made in the complex expression for the Rayleigh number to get useful and interesting results. The bottom heavy binary nanofluids are more stable than the regular binary fluids, while the top heavy binary nanofluids are less stable than the regular binary fluids. The critical wave number and the critical Rayleigh number in- crease whereas the frequency of oscillation （for the bottom heavy configuration） decreases when the Chandrasekhar number increases. The numerical results for the alumina-water nanofiuid are studied by use of the MATHEMATICA software.
