Birla Institute of Technology, Mesra

About: Birla Institute of Technology, Mesra is a education organization based out in Ranchi, India. It is known for research contribution in the topics: Computer science & Dielectric. The organization has 2801 authors who have published 4789 publications receiving 52426 citations. The organization is also known as: BIT.

Software defined radio: Operation, challenges and possible solutions

Abstract: Software Defined Radio (SDR) or Software Radio is one of the most important technologies for the modern wireless communication system. SDR is a radio which can tune to any frequency band, implement different modulation and demodulation schemes and different standards in the same device by using reconfigurable hardware and powerful software. SDR provides flexible, upgradeable, multi-standard and longer lifetime radio equipment for both the military and for civilian wireless communications infrastructure. This paper provides a detailed analysis of SDR hardware and its operation focusing on analog front end and digital front end. The paper also highlights the benefits of SDR. However, it was expected to implement SDR since the third generation of wireless communication but many practical challenges that SDR faces, causing SDR evolution slower. This paper also discusses some of the current issues impacting the SDR technology and investigates how they are being resolved.

Tailoring the performance of bamboo filler reinforced epoxy composite: insights into fracture properties and fracture mechanism

Abstract: Due to the graded micro-structure and high specific strength-stiffness, bamboo micro fillers are systematically utilized in reinforcing different thermoset and thermoplastic polymers as replacement of conventional glass and carbon fillers. In this work, micro-size bamboo particle fillers are reinforced in ‘specific grade’ thermoset epoxy matrix and its fracture properties has been evaluated by following linear elastic fracture mechanics. To enhance its compatibility with the polymer matrix and to reduce the hydrophilicity, the bamboo micro fillers are surface modified through alkaline treatment. The extent of surface modification and removal of lower weight polymers from filler surface are examined and established by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction analysis and thermogravimetric analysis. The fracture properties of bamboo-epoxy composite material are observed to be increasing with the addition of bamboo fillers and the maximum value of fracture toughness is 0.678 MPa.m0.5 which is 32% higher than the same for neat epoxy samples. In addition, the mechanisms of notch initiated fracture propagation have also been explained for the understanding of stress singularity present at the preexisted crack tip.

A Simple and Generalized Space Vector PWM Control of Cascaded H-Bridge Multilevel Inverters

Abstract: This paper presents an automatic switching pattern generation for multilevel cascaded H-bridge inverters with equal dc voltage sources, based on the space-vector pulse width modulation (SVPWM) techniques. The proposed switching strategy generates a voltage vector with very low harmonic distortion and reduced switching frequency. This new control method is an attractive alternative to the classic multilevel pulse width modulation techniques considering the following aspects, mainly, minimization of voltage and current total harmonic distortion (THD), extension of range of linear operation; and least number of commutations. To solve the problem of computational complexity in multilevel inverters due to the large number of space vectors and redundant switching states, a simple and general space vector PWM algorithm is proposed. Based on this algorithm, the location of the reference voltage vector can be easily determined and the calculation of dwell times becomes very simple. It is also mentioned that this method requires lower memory spaces as there is no need of any look-up table. To verify the algorithms, a seven-level cascaded H-bridge inverter drive system was constructed and simulation results are present here.

A novel dissolution media for testing drug release from a nanostructured polysaccharide-based colon specific drug delivery system: an approach to alternative colon media.

Abstract: The aim of this study was to develop a novel microbially triggered and animal-sparing dissolution method for testing of nanorough polysaccharide-based micron granules for colonic drug delivery. In this method, probiotic cultures of bacteria present in the colonic region were prepared and added to the dissolution media and compared with the performance of conventional dissolution methodologies (such as media with rat cecal and human fecal media). In this study, the predominant species (such as Bacteroides, Bifidobacterium, Lactobacillus species, Eubacterium and Streptococcus) were cultured in 12% w/v skimmed milk powder and 5% w/v grade "A" honey. Approximately 10(10)-10(11) colony forming units m/L of probiotic culture was added to the dissolution media to test the drug release of polysaccharide-based formulations. A USP dissolution apparatus I/II using a gradient pH dissolution method was used to evaluate drug release from formulations meant for colonic drug delivery. Drug release of guar gum/Eudragit FS30D coated 5-fluorouracil granules was assessed under gastric and small intestine conditions within a simulated colonic environment involving fermentation testing with the probiotic culture. The results with the probiotic system were comparable to those obtained from the rat cecal and human fecal-based fermentation model, thereby suggesting that a probiotic dissolution method can be successfully applied for drug release testing of any polysaccharide-based oral formulation meant for colonic delivery. As such, this study significantly adds to the nanostructured biomaterials' community by elucidating an easier assay for colonic drug delivery.