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High-pressure X-ray diffraction studies on gadolinium sesquioxide (Gd2O3) have been carried out up to a pressure of ∼25 GPa in a diamond-anvil cell at room temperature. Gadolinium oxide, which has a cubic or bixbyite structure under ambient conditions, undergoes an irreversible structural phase at around 12 GPa. The high-pressure phase has been identified as a hexagonal La2O3-type structure. The bulk modulus and its pressure derivative of this phase have been calculated.

This letter reports a novel in vitro test of blood analysis based on the measurement of the dielectric properties at microwave frequencies. The measurements were made using rectangular cavity perturbation technique at the S-band of microwave frequency with the different samples of blood obtained from healthy donors as well as from patients. It is observed that an appreciably change in the dielectric properties of patient samples with the normal healthy samples and this measurements were in good agreement with clinical analysis. This measurement technique is nondestructive in nature. These results indicate an alternative in-vitro method of diagnosing blood abnormalities using microwaves.

The effect of the electromagnetic fields on the human brain due to the usage of mobile phones is an active research area. These effects are a direct function of the electrical properties of the brain tissue which depends on the bound water content. This paper reports the microwave study of cerebrospinal fluid (CSF), the main constituent of which is water. Both normal and pathologically abnormal CSF samples are subjected to the microwave study and a study of the variation of the dielectric parameters of CSF with frequency is done for both the normal and pathologically different samples. In this communication, in vitro measurements using cavity perturbation technique is employed. The frequency range employed is between 2 to 3 GHz. It is seen that in the band of frequencies employed for the study, the normal and abnormal CSF samples exhibit distinctive behavior for the variation of dielectric constant and conductivity with frequency.

This article communicates the study of both the dielectric properties of human colostrums and breast milk at microwave frequencies. The colostrum samples were taken immediately after child birth and breast milk samples were collected at weekly intervals following the delivery. Rectangular cavity perturbation technique is used for the measurements of dielectric properties at the S-band of microwave frequency. The dielectric constants of the colostrums samples and breast milk samples are found to increase as weeks elapse, which is attributed to the reduced fat content and increased lactose concentration. The conductivity of these samples is similarly found to increase due to the increased dilution.

Microwave dielectric properties and crystal structure of Sr1-xBaxNb2O6 ceramics (x = 0·39, 0·45, 0·50, 0·55, 0·57, 0·60, 0·65) have been investigated. The microwave cavity perturbation technique was employed for the study of dielectric properties. Parameters such as complex permittivity and conductivity of strontium barium niobate ceramics were determined at the S band by measuring changes in the resonant frequencies and Q values of the cavity resulting from the introduction of the sample. The real part of the complex permittivity of all samples shows an increase with frequency, whereas the imaginary part of permittivity decreases as frequency increases. The effects of composition and sintering temperature on crystal structure and microstructure were studied by X-ray powder diffraction and scanning electron microscopy. Most compositions show preferred orientations along the c axis, as is evident from the relatively high intensity of (001) and (002) peaks. The microstructure contains ferroelectric ...