Preparation and Characterization of SnO2 Nanofibers via Electrospinning

Tin oxide (SnO2) nanofibers are successfully prepared by electrospinning homogeneous viscous solutions of tin acetate in polyvinylpyrrolidone (PVP). The electrospinning is carried out by applying a DC voltage to the tip of a syringe and maintaining the tip to collector distance (TCD), i.e. at DC electric field of 1.25 kV•cm–1. The electrospun nanofibers are calcined between 550℃ and 650℃ for 4 h. Both spun and heat treated nanofibers are characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infra red spectroscopy (FTIR) etc. XRD analysis of calcined nanofibers confirms the formation of pure tin oxide. TEM study showed that fibers have a polycrystalline structure with multiple nano-grains.

An Optimal Lempel Ziv Markov Based Microarray Image Compression Algorithm

In the recent years,microarray technology gained attention for concurrent monitoring of numerous microarray images.It remains a major challenge to process,store and transmit such huge volumes of microarray images.So,image compression techniques are used in the reduction of number of bits so that it can be stored and the images can be shared easily.Various techniques have been proposed in the past with applications in different domains.The current research paper presents a novel image compression technique i.e.,optimized Linde–Buzo–Gray(OLBG)with Lempel Ziv Markov Algorithm(LZMA)coding technique called OLBG-LZMA for compressing microarray images without any loss of quality.LBG model is generally used in designing a local optimal codebook for image compression.Codebook construction is treated as an optimizationissue and can be resolved with the help of Grey Wolf Optimization(GWO)algorithm.Once the codebook is constructed by LBGGWO algorithm,LZMA is employed for the compression of index table and raise its compression efficiency additionally.Experiments were performed on high resolution Tissue Microarray(TMA)image dataset of 50 prostate tissue samples collected from prostate cancer patients.The compression performance of the proposed coding esd compared with recently proposed techniques.The simulation results infer that OLBG-LZMA coding achieved a significant compression performance compared to other techniques.

A Novel Low Temperature Synthesis of KNN Nanoparticles by Facile Wet Chemical Method

Sodium potassium niobate (KNN) (K0.5Na0.5NbO3) nanopowder with a mean particle size of about 20 - 30 nm was synthesized by wet chemical route using Nb2O5 as Nb source. A solution of K, Na and Nb cations was prepared, which resulted in a clear gel after the thermal treatment. Phase analysis, microstructure and morphology of the powder were determined by X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Field Emission Scanning Electron Microscopy (FESEM). The obtained gel was first analyzed by Thermo Gravimetric Analyzer (TGA) and Differential Scanning Calorimetry (DSC), and then calcined at different temperatures of 400℃, 500℃, 600℃ and 700℃. The X-Ray Diffraction (XRD) patterns of the synthesized samples confirmed the formation of the orthorhombic crystal phase of K0.5Na0.5NbO3 at 500?C, a temperature significantly lower than that typically used in the conventional mixed oxide route. The process developed in this work is convenient to realize the mass production of KNN nanopowders at low cost and suitable for various industrial applications.

Influence of Sintering Temperature on Densification, Structure and Microstructure of Li and Sb Co-Modified (K,Na)NbO₃-Based Ceramics

Polycrystalline samples of Lead free (K0.5Na0.5)1-x(Li)x(Sb)x(Nb)1-xO3 ceramics with nominal compositions (x = 0.040 to 0.060) have been prepared by high temperature solid state reaction technique. X-ray diffraction (XRD) pattern shows that the crystal structure transforms from orthorhombic to tetragonal as Li and Sb content increases. Normal sintering process yield compounds with density ~98.2% of the theoretical value. Densification of the Li and Sb co-doped KNN ceramics might be explained by the liquid-phase sintering. This may be attributed to the low melting temperature of Li compounds that appears to promote the formation of a liquid phase during sintering.

Study of the structural and electrical behavior of Bi(Mg,Ti)O_(3)modified(Ba,Ca)TiO_(3)ceramics

The ability of BaTiO_(3)to form solid solutions with different dopants(both iso-and aliovalent)makes it versatile for various applications.In the present study,(Ba,Ca)TiO_(3)(BCT)is modified with Bi(MgTi)O_(3)(BMT)in search for new lead-free ferroelectric material and improve their properties.For this purpose,BCT acts as a main base material and BMT acts as a modifier to fabricate a multifunctional material.In this study,we report the structural and electrical properties of lead free piezo-ceramics(1-x)(Ba_(0.8)Ca_(0.2))TiO_(3–x)Bi(Mg_(0.5)Ti_(0.5))O_(3)with x=0.2,0.4,0.5 prepared by solid-state sintering technique.Single perovskite phase with tetragonal structure is obtained for all the compositions,which is reconfirmed by the Raman Spectroscopic study.Dielectric study confirm the temperature stable behavior of the dielectric permittivity values above 300℃.The dielectric constant value decreases with increase in BMT doping content.Impedance Spectroscopic study confirms non-Debye type dielectric relaxation in the specimen.The Nyquist plot and conductivity studies show the negative temperature coefficient of resistance behavior(NTCR)of the samples.