Effect of calcination temperature on structural and morphological properties of bismuth ferrite nanoparticles

Bismuth Ferrite (BiFeO3) is one such materials which has shown very promising multiferroic and excellent optical properties. In this paper, we report effect of annealing temperature on the structural, morphological and optical properties of BiFeO₃ nanoparticles synthesised through sol-gel auto-combustion method. Nanoparticles prepared were calcined at three different temperatures, 400 °C, 500 °C and 600 °C, and named as BFO1, BFO2 and BFO3, respectively. X-ray diffraction confirmed the rhombohedral structure with R3c space group as a primary phase. However, a secondary phase Bi₂Fe₄O₉ was also observed which decreases with increasing temperature. The crystallite sizes were found to increase with increasing temperature with BFO2 as anomaly. Field emission scanning electron microscopy (FESEM) shows clear grain formation for all the samples. TEM micrographs and SAED patterns show crystalline grains with rhombohedral structure. All the functional groups observed in the Fourier infrared spectroscopy (FTIR) measurement are indexed. The FTIR spectra shows presence of two prominent vibrational modes in the wave number range 447 and 560 cm^-1 corresponding to the stretching of Fe-O bonds. Raman analysis shows presence of a peak at ~527 cm^-1 for (BFO3) which was absent in other two samples. Also, the intensity of the A₁-1 mode was found stronger than that of A₁-2 mode in all the samples which confirmed the stability of the structure, except for BFO1.     

A novel hybrid security mechanism for data communication networks

Multimedia Tools and Applications - With the growing internet technology over the last decade, the number of intruders trying to steal the confidential information has also risen. As a result, for...     

Influence of Parathyroid Hormone-Loaded PLGA Nanoparticles in Porous Scaffolds for Bone Regeneration

Biodegradable poly(lactide-co-glycolide) (PLGA) nanoparticles, containing human parathyroid hormone (PTH (1–34)), prepared by a modified double emulsion-solvent diffusion-evaporation method, were incorporated in porous freeze-dried chitosan-gelatin (CH-G) scaffolds. The PTH-loaded nanoparticles (NPTH) were characterised in terms of morphology, size, protein loading, release kinetics and in vitro assessment of biological activity of released PTH and cytocompatibility studies against clonal human osteoblast (hFOB) cells. Structural integrity of incorporated and released PTH from nanoparticles was found to be intact by using Tris-tricine SDS-PAGE. In vitro PTH release kinetics from PLGA nanoparticles were characterised by a burst release followed by a slow release phase for 3–4 weeks. The released PTH was biologically active as evidenced by the stimulated release of cyclic AMP from hFOB cells as well as increased mineralisation studies. Both in vitro and cell studies demonstrated that the PTH bioactivity was maintained during the fabrication of PLGA nanoparticles and upon release. Finally, a content of 33.3% w/w NPTHs was incorporated in CH-G scaffolds, showing an intermittent release during the first 10 days and, followed by a controlled release over 28 days of observation time. The increased expression of Alkaline Phosphatase levels on hFOB cells further confirmed the activity of intermittently released PTH from scaffolds.     

Role of Process Variables on the Solid Particle Erosion of Polymer Composites: A Critical Review

This paper presents a review of the reported research investigations that are related to the solid particle erosion behavior of polymers and polymeric composites. Attention is paid to the effects of test parameters such as erodent type, size of the erodent, impingement angle, impact velocity and stand of distance. On the erosion wear rate of polymer composites. Various predictions and models proposed by different authors to describe and quantify the erosion rate are discussed and their suitability is checked. Recent findings on the erosion response of multi-component hybrid composites are also presented. Lastly the implementation of the design of experiments and statistical techniques in making a parametric appraisal of the erosion processes of composites is discussed.     

Enhancing the Route Optimization Using Hybrid MAF Optimization Algorithm for the Internet of Vehicle

Wireless Personal Communications - Wireless Sensor Networks (WSNs) in modern times enables security techniques to secure the information transmitted via the interconnected network. The poor...     

Implementation of Vertex-Fed Multiband Antenna for Wireless Applications with Frequency Band Reconfigurability Characteristics

In this paper authors present the design and analysis of split ring resonator based multiband antenna for wireless applications with frequency-band reconfigurable features. The proposed design has octagonal shape SRR structure fed at vertex as radiating section and rectangular shape switchable slotted ground part. The antenna has dimensions of 44?×?39?×?1.6 mm³ and fabricated on FR4 substrate. The proposed structure exhibit hexa operating resonance characteristics at 3.3, 5.0, 5.8, 6.6, 9.9 and 15.9 GHz to cover the wireless standards at lower WiMAX, upper WLAN, super extended C-band, middle X band and lower K_U band respectively. Antenna achieve the frequency band reconfigurability characteristics by inserting PIN diode in slotted ground (reclined L-shaped) as triple/hexa resonant bands during OFF/ON switching state of PIN diode. An acceptable gain, stable and consistent radiation patterns with low cross polarization and good impedance matching are obtained at targeted frequency bands of proposed design.