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The development of barium strontium titanate-based tunable dielectrics is currently hindered by high losses in the paraelectric phase. Barium strontium titanate (BST) thin films and ceramics show a range of ferroelectric transition behavior, from normal, diffuse, and relaxor-like ferroelectric responses, depending on the sample preparation route. Rayleigh analysis, the temperature-dependent dielectric response, and the optical second harmonic generation were used to characterize the ferroelectric response of bulk and thin film BST. Ferroelectricity is observed to persist in BST for 30°C above the global phase transition temperature in ceramics and over 50°C in thin films. Piezoresponse force microscopy on BST ceramics with extensive residual ferroelectricity reveals the coexistence of nanoscale polar regions, typical of relaxor ferroelectrics, as well as micrometer scale domain structures. The nature of the phase transition was probed using electron energy loss spectroscopy and found to correlated with the nanoscale A-site chemical inhomogeneity in the samples.

This study examines the capability assessment of fully polarimetric L-band data for snow and non-snow area classification. The data sets used are the fully polarimetric Advanced Land Observation Satellite – Phased Array type L-band Synthetic Aperture Radar (ALOS-PALSAR) data, optical (ALOS-AVNIR) data close to the radar acquisition, and ENVISAT-ASAR data. Several parameters are used to discriminate snow from non-snow-covered areas in the Indian Himalaya region, including backscattering coefficients, the ratio of cross/co-polarized backscattering power and polarization fraction value. Supervised classification schemes are employed using polarimetric decomposition methods based on the complex Wishart classifier. The accuracy of the classification was found to be 97.95% for the Wishart supervised classification. Among various parameters and methods, it was found that the alternative newly proposed Polarization Fraction (PF) scheme, based on the implementation of fully polarimetric synthetic aperture radar (POL-SAR) data, yielded the best classification result in the absence of training samples. The PF value has been effective for discrimination of snow-covered from non-snow-covered areas, debris covered glacier, and vegetation. The results of this investigation show that L-band fully polarimetric SAR data provide considerable improvement but may not possess the optimal capability to discriminate snow from other inherent natural and man-made scatterers in heavy snow laden mountainous scenarios which may require fully polarimetric S-Band or C-Band POLSAR measurements.

Screening of proteins for crystallization under laser irradiation was investigated using six proteins: ribonuclease B, glucose dehydrogenase, lysozyme, sorbitol dehydrogenase, fructose dehydrogenase and myoglobin. Shining 532 nm green circularly polarized laser light with a picosecond pulse and 6 mW power for 30 s on newly set-up protein drops showed a marked improvement in the number of screen conditions amenable for crystal growth compared with control drops under identical conditions but without laser exposure. For glucose dehydrogenase and sorbitol dehydrogenase, larger and better quality crystals were formed and the resolution of X-ray diffraction was improved. The speed of crystallization increased in the case of ribonuclease B, lysozyme and sorbitol dehydrogenase. During laser irradiation, the amount of precipitation in the screened drops increased, indicating a transient decrease in protein solubility. At the optimized laser settings, there was no deleterious effect of the laser on crystal growth or on the protein. In the cases of ribonuclease B and lysozyme the crystal packing did not change owing to the laser exposure.