Vignan University

About: Vignan University is a education organization based out in Guntur, Andhra Pradesh, India. It is known for research contribution in the topics: Control theory & CMOS. The organization has 1138 authors who have published 1381 publications receiving 7798 citations.

Removal of multiple metals using Tamarindus indica as biosorbent through optimization of process variables: a statistical approach

Abstract: In the present study, biosorption capacity of Tamarindus indica is investigated for removal of lead and zinc. The heavy metals, namely lead and zinc, are successfully removed from aqueous solution by batch biosorption using Tamarindus indica as biosorbent. The removal percentage of selected metals, namely lead and zinc, was improved through optimization of variables using response surface methodology (RSM). The conditions obtained with RSM are agitation time of 47.65 min, initial metal ion concentration of 46.49 mg/l, biosorbent dosage of 1.23 g and pH of 7.64 for lead biosorption, whereas those for zinc are agitation time of 22.84 min, dosage of 0.78 g, initial ion concentration of 20.87 mg/l and pH of 6.98. The maximum of 83.52% removal of lead was achieved and for zinc 63.7%. Heavy metal biosorption ability of biosorbent has been qualitatively characterized using Fourier transform infrared spectroscopy and scanning electron microscopy analysis. This study reveals that the Tamarindus indica efficiently removes heavy metals. The biosorption kinetic study at RSM optimized conditions exhibited better fit to Freundlich isotherms (R2 0.993) for lead than Langmuir isotherm (R2 0.974).

A Novel Approach for Minimization of Tool Vibration and Surface Roughness in Orthogonal Turn Milling of Silicon Bronze Alloy

Abstract: The advanced manufacturing system is aimed to produce components at right quantity, quality and cost. Turnmilling is one of the advanced machining techniques that combines turning and milling processes for high metal removal rate. In orthogonal turn milling, bottom surface of the end mill cutter removes material from the surface of a rotating workpiece. Optimization of process parameters plays an important role in machining to improve quality and productivity and reduce production cost. In the present work, an advanced teaching learning based optimization (TLBO) technique was introduced to optimize process parameters in orthogonal turn milling of Silicon Bronze. Experiments were conducted at five levels of cutting speed, feed and depth of cuts. Experimental results of surface roughness and amplitude of cutter vibration were analysed using analysis of variance. The experimental results were also used to optimize process parameters through TLBO. Experiments were also conducted using TLBO optimized process parameters and the results were compared with TLBO results. The TLBO results were found to be in good agreement with target values of the responses. Artificial neural networks were developed for the surface roughness and amplitude of cutter vibration to verify optimization.

Thermal protection coatings of metal oxide powders

Abstract: Metal oxide powders and thick and thin films of metal oxides are drawing the attention of researchers owing to their use in industry and societal applications. To improve the efficiency, lifetime and also to arrest the degradation of the composition, protection coatings are very much important. Continuous development in finding out newer materials and composites is essential to meet the challenges posed by the demands. In this chapter the necessity of thermal protection coating and the development of coatings on various metal oxide powders by various physical and chemical deposition techniques are discussed.

A new low-power full-adder cell for low voltage using CNTFETs

Abstract: One of the most crucial components in the computing devices is the full adders. The efficiency and effectiveness of arrays of full adders is essential; thus making it sensible to put in a reasonable effort towards improvisation of computational devices. In this paper, a new 1-BIT Full Adder (FA) with a combination of pass transistor logic and transmission gate logic is suggested. This new hybrid adder is having only 18 transistors. The proposed full adder is a CNTFET based design and also implemented 8-BIT Ripple carry Adder (RCA) at 32 nm CNTFET model files using the Cadence virtuoso tool.