Development of Synthetic Ketonic Resin

In the present work, the self-polymerization reaction of cyclohexanone was studied to develop a synthetic resin. Synthetic resins are extensively used in paint industry to improve the adhesiveness of paints. Polymerization reactions were carried out in a high-pressure reactor. The results suggest that the self-polymerization of cyclohexanone mainly depends on alkali concentration, reaction temperature, and reaction time. As the ketone-to-alkali ratio decreases, the degree of polymerization increases, which leads to an increase in the hydroxyl value and softening point and a remarkable decrease in solubility. A good-quality solid resin could be obtained with a ketone-to-alkali ratio less than 5 in the temperature range between 130°C and 160°C and within the time duration of 12–22 h. These data may be useful to develop the desired quality of resin in the field of paint application.     

Cooperative spectrum sensing in cognitive radio network using multiobjective evolutionary algorithms and fuzzy decision making

The cognitive radio has emerged as a potential solution to the problem of spectrum scarcity. Spectrum sensing unit in cognitive radio deals with the reliable detection of primary user’s signal. Cooperative spectrum sensing exploits the spatial diversity between cognitive radios to improve sensing accuracy. The selection of the weight assigned to each cognitive radio and the global decision threshold can be formulated as a constrained multiobjective optimization problem where probabilities of false alarm and detection are the two conflicting objectives. This paper uses evolutionary algorithms to solve this optimization problem in a multiobjective framework. The simulation results offered by different algorithms are assessed and compared using three performance metrics. This study shows that our approach which is based on the concept of cat swarm optimization outperforms other algorithms in terms of quality of nondominating solutions and efficient computation. A fuzzy logic based strategy is used to find out a compromise solution from the set of nondominated solutions. Different tests are carried out to assess the stability of the simulation results offered by the heuristic evolutionary algorithms. Finally the sensitivity analysis of different parameters is performed to demonstrate their impact on the overall performance of the system.     

Directional Properties of Cold Rolled Non-oriented Electrical Steel Sheets

Applications of cold rolled non-oriented (CRNO) electrical steels demand uniform magnetic property in all directions. The objective of the present study was to investigate the magnetic properties of CRNO steel in different directions. Four different sets of samples were made from CRNO steel sheets—(1) samples along the rolling direction, (2) samples at 30° to the rolling direction, (3) samples at 60° to the rolling direction and (4) samples at 90° to the rolling direction. The textural and magnetic properties were investigated using standard techniques. X-ray diffraction and electron backscattered diffraction were used for bulk- and micro-texture measurements respectively. Single sheet tester was used for core loss and magnetic permeability measurements. The results showed different textural and magnetic properties in all the CRNO samples. However, the properties were always better in rolling direction where the texture was more.     

High speed multiplier using Nikhilam Sutra algorithm of Vedic mathematics

This article presents the design of a new high-speed multiplier architecture using Nikhilam Sutra of Vedic mathematics. The proposed multiplier architecture finds out the compliment of the large operand from its nearest base to perform the multiplication. The multiplication of two large operands is reduced to the multiplication of their compliments and addition. It is more efficient when the magnitudes of both operands are more than half of their maximum values. The carry save adder in the multiplier architecture increases the speed of addition of partial products. The multiplier circuit is synthesised and simulated using Xilinx ISE 10.1 software and implemented on Spartan 2 FPGA device XC2S30-5pq208. The output parameters such as propagation delay and device utilisation are calculated from synthesis results. The performance evaluation results in terms of speed and device utilisation are compared with earlier multiplier architecture. The proposed design has speed improvements compared to multiplier architecture presented in the literature.     

Effect of Zn concentration on diffusion induced grain boundary migration in Cu -Zn system

Cu-Zn alloy system with three different compositions has been chosen to study the time, temperature and composition dependence of the Diffusion Induced Grain boundary Migration (DIGM) in the temperature range of 277–427°C. The grain boundary migration follows parabolic rate law as a function of time. The diffusivity, D_bα, was calculated from concentration-distance profile using growth rate, v. The activation energy for diffusion is found to be 101kJ/mol which is nearly half of the activation energy required for volume diffusion indicating that preferential grain boundary diffusion is more favorable than volume diffusion leading to grain boundary migration in Cu-Zn system.     

Low-temperature magnetic and electromagnetic studies of Y-Ba-Cu-O: Agx Ceramic superconductor

Magnetization and magnetic relaxation measurements have been studied at 4.2 K on YBa₂Cu₃O_7–:Ag _x (x=0 to 1.2) superconducting samples prepared by a coprecipritation technique. Remanent magnetization and hysteresis loops were found to be increased on Ag addition. Transport current density (J _c) was enhanced with the addition of Ag concentration. Flux creep rate was also increased with increase in Ag addition resulting in stronger pinning potential. Microwave-induced d.c. voltage measurements show a reduction of weak links with increase in Ag concentration. The enhancement of transportT _c is attributed to the stronger Josephson current paths due to the reduction of the total number of weak links after Ag addition.     

Area-Optimized BCD-4221 VSLI Adder Architecture for High-Performance Computing

Decimal arithmetic circuits are promising to provide a solution for accurate decimal arithmetic operations which are not possible with binary arithmetic circuits. They can be used in banking, commercial and financial transactions, scientific measurements, etc. This article presents the Very Large Scale Integration(VLSI) design of Binary Coded Decimal(BCD)-4221 area-optimized adder architecture using unconventional BCD-4221 representation. Unconventional BCD number representations such as BCD4221 also possess the additional advantage of more effectively representing the 10''s complement representation which can be used to accelerate the decimal arithmetic operations. The design uses a binary Carry Lookahead Adder (CLA) along with some other logic blocks which are required to perform internal calculations with BCD-4221 numbers. The design is verified by using Xilinx Vivado 2016.1. Synthesis results have been obtained by Cadence Genus16.1 synthesis tool using 90 nm technology. The performance parameters such as area, power, delay, and area-delay Product (ADP) are compared with earlier reported circuits. Our proposed circuit shows significant area and ADP improvement over existing designs.     

Non-isothermal crystallization of Ziegler Natta i-PP-graphene nanocomposite: DSC and new model prediction

Crystallization occurs in processing i-PP-GnP nanocomposites, and these nanocomposites have the potential to replace traditional fillers and be used to fabricate advanced materials and technology. Therefore, this subject was comprehensively investigated by applying a recent crystallization model, non-isothermal DSC experiments, Raman spectroscopy, and WAXRD. The multi-layer GnP-induced nucleation and the crystal growth rates were modelled. The overall modelling effort generated new insights, results, and explanations. This study confirmed and elucidated, or refuted several published conclusions. It has also been reported that the present model can pursue differences in catalyst-mediated i-PP backbone defects (stereo and regio) by simulating the relative crystallization profile and determining the crystallization kinetic triplet (n, k _o, and E _a). The multiple roles played by GnP were underscored, which exceed what the related literature currently reports. The Raman and XRD work revealed the interaction between GnP and i-PP. The shear-induced dispersion of GnP that occurs during extrusion significantly affected i-PP crystal size distribution. The present approach can also assess the effects of catalyst type and structure, and backbone defect types and their distribution on the non-isothermal crystallization of, in general, polyolefin blends and nanocomposites.