Outage Performance of Uplink (UL) NOMA Network

Wireless Personal Communications - This paper proposes and analyses the power allocation coefficient normalization for successive interference cancellation in power-domain non-orthogonal multiple...     

Development of a new radioanalytical technique for the determination of manganese(II) using potassium periodate

A radiometric method based on redox substoichiometry was applied to accurate and precise determination of manganese. The proposed technique is based on the substoichiometric oxidation of bivalent manganese to permanganate ions with potassium periodate, followed by isolation of the oxidized species by the extraction with tri-n-octylamine in chloroform. The method was successfully applied to the estimation of manganese content of various certified ores and alloys.     

Elimination of Surface Defects in High Tensile Steel for Wheel Rim Application

One of the important applications of high tensile steel grades is in wheel rims by the automotive industry. High tensile steel facilitates vehicle weight reduction under the ‘Go Green’ initiative. Along with weight reduction, in recent times, the surface quality requirement of steels for wheel rim applications has also gained a significant focus, and in many cases, it is becoming the cause of rejection at the customers’ processing line. It is known that owing to chemistry requirements such high strength steel grades generally show peritectic behavior during solidification and are prone to surface defects. Tata Steel India produces several wheel rim grades of varying strength levels. In one such high manganese and micro-alloyed peritectic steel grade, the rejection by the customer on account of surface defects was a major concern. The defects consisted of typical longitudinal cracks of varying dimensions along with the unique defects in transverse direction named tear marks on the surface of 100-mm-thick plates rolled from 215-mm-thick slab. In subsequent stages, these plates were processed into rim profiles through hot working by the wheel customer. The paper highlights how systematic study led to arrive at root causes and helped redesign steel chemistry to ensure zero rejection for surface quality without affecting mechanical property requirements.     

Approximating total citation counts from first author counts and from total papers

This paper is an attempt to improve on the approximation. First author citations (C_f)≈Total citations (C_t) of an author's publications without the work of making the complete citation count under the author and all co-author names. Using the bibliographies of all faculty from each of four large departments: Physics, Chemistry, Materials Sciences, and Biosciences, in the same university, both first author and complete citation counts were made, care being taken to avoid the most common errors in such counts. It is shown that the function C_f·T/F (where T and F are the total number of papers and F those with subject author's name first) correlates strongly (>90%) with C_t. We find also that C_t correlates strongly with T. The data also may be used as one more line of evidence to obtain normalizing ratios for possible comparisons of productivityacross different disciplinary universes. A very tentative ratio from different studies would be 8 (Chem.)=4 (Physics)=2.5 (Mat. Sci.)=2 (Mathematics)=4.5 (Biophysics-Biochemistry).     

Soft computing-based approaches to predict energy consumption and stability margin of six-legged robots moving on gradient terrains

Soft computing-based approaches have been developed to predict specific energy consumption and stability margin of a six-legged robot ascending and descending some gradient terrains. Three different neuro-fuzzy and one neural network-based approaches have been developed. The performances of these approaches are compared among themselves, through computer simulations. Genetic algorithm-tuned multiple adaptive neuro-fuzzy inference system is found to perform better than other three approaches for predicting both the outputs. This could be due to a more exhaustive search carried out by the genetic algorithm in comparison with back-propagation algorithm and the use of two separate adaptive neuro-fuzzy inference systems for two different outputs. A designer may use the developed soft computing-based approaches in order to predict specific energy consumption and stability margin of the robot for a set of input parameters, beforehand.     

A multi-step linearization technique for a class of boundary value problems in non-linear mechanics

Non-linear finite element analyses of structures (such as beams) involve construction of weak solutions for the governing equations. While a weak approach weakens the differentiability requirements of the so-called shape functions, the governing equations are only satisfied in an integral sense and not point-wise, or, even path-wise. Moreover, use of a finite mesh leads to a stiffening of the numerical model. While strong solutions obtained through some of the existing mesh-free collocation methods overcomes some of these lacunae to an extent, the quality of the numerical solutions would be considerably improved if the computational algorithm were able to faithfully reproduce (or approximate or preserve) certain geometrical features of the response surfaces or manifolds. This paper takes the first step towards realizing this objective and proposes a multi-step transversal linearization (MTL) technique for a class of non-linear boundary value problems, which are treated as conditionally dynamical systems. Numerical explorations are performed, to a limited extent, through applications to large deflection analyses of planar beams with or without plastic deformations.     

Electrodeposited carbon nanotube thin films

A successful attempt to grow carbon nanotubes (CNTs) by electrodeposition technique for the first time is reported here. Carbon nanotubes were grown on Si (001) substrate using acetonitrile (1% v/v) and water as electrolyte at an applied d.c. potential ∼20 V. The films were characterized by X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), Raman, optical absorbance, Fourier Transform Infra Red spectroscopy (FTIR) and Electron Spin Resonance (ESR) measurements. The effect of magnetic field on the growth of nanotubes was studied critically. It was found that the presence of magnetic field during electro-deposition played a crucial role on the growth of carbon nanotubes and hence the electronic properties. Photoluminescence (PL) studies indicated band edge luminescence ∼0.72-0.83 eV. Field emission studies indicated lower turn-on voltage and higher current density for films deposited with magnetic field.     

Synthesis of MgAl2O4 spinel: seeding effects on formation temperature

Four different methods of MgAl₂O₄ spinel synthesis in the presence and absence of seeds were studied. The four methods used for MgAl₂O₄ synthesis were (a) one sol (boehmite) and one solution [Mg(NO₃)₂]; (b) two sols (boehmite and magnesia); (c) two nitrates (Al and Mg nitrates) and two alkoxides (Al isopropoxide and Mg ethoxide). The use of a nitrate route led to the formation of spinel at the lowest temperature without the influence of seeding. Seeding with spinel crystallites of all the powders except the one-sol and one-solution diphasic gels apparently resulted in a lower formation temperature of MgAl₂O₄ spinel, and this lowering of crystallization temperature can be explained by the nucleation and epitaxial growth mechanism.     

Starch as a Source of Sweetners. The Actual Situation in the United States of America

It is apparent that in the USA a significant trend is underway in the sweetener field. An economic process has now been developed to commercially hydrolyze a starch slurry to D-glucose with glucoamylase enzyme and to convert the D-glucose to a mixture of approximately equal parts of D-glucose and D-fructose with isomerase enzyme. Apart from isomerase converted corn syrups, the other sugars derived from starch, such as corn syrups and sugars and crystalline dextrose as well as maltose, maltotriose and maltitol are important sweetners.