Redefined SI Units and Their Implications

Metrology plays the key role as the engine of industrial revolution and growth of any country. It promotes global competence and confidence. With the advent of better quality products through metrological advancement, our industries can compete internationally and to overcome trade barriers/constraints and finally to achieve exports targets. This translates into growth of industries through rapid industrialization, economic growth and societal upliftment. The metrology requires continued and sustained efforts to cater the stakeholders’ demands for advancements in measurement technologies, standards and measurement techniques for more and more precise, reliable, reproducible and accurate measurements with improved measurement uncertainties. In this context, the recent revolutionary changes in redefinition of SI units based on fundamental constants were unanimously voted for adoption by world community during November 16, 2018, at Versailles, France, and implemented world over from May 20, 2019—the World Metrology Day. Therefore, it was considered appropriate to compile a brief status report and apprise the readers about these historical events. The present paper touches glimpse of some of these activities and describes the implications of these changes in our daily life.     

α-Alumina and spinel react into single-phase high-alumina spinel in <3 seconds during flash sintering

In situ X-ray diffraction measurements at the Advanced Photon Source show that α-Al₂O₃ and MgAl₂O₄ react nearly instantaneously and completely, and nearly completely to form single-phase high-alumina spinel during voltage-to-current type of flash sintering experiments. The initial sample was constituted from powders of α-Al₂O₃, MgAl₂O₄ spinel, and cubic 8 mol% Y₂O₃-stabilized ZrO₂ (8YSZ) mixed in equal volume fractions, the spinel to alumina molar ratio being 1:1.5. Specimen temperature was measured by thermal expansion of the platinum standard. These measurements correlated well with a black-body radiation model, using appropriate values for the emissivity of the constituents. Temperatures of 1600-1736°C were reached during the flash, which promoted the formation of alumina-rich spinel. In a second set of experiments, the flash was induced in a current-rate method where the current flowing through the specimen is controlled and increased at a constant rate. In these experiments, we observed the formation of two different compositions of spinel, MgO•3Al₂O₃ and MgO•1.5Al₂O₃, which evolved into a single composition of MgO•2.5Al₂O₃ as the current continued to increase. In summary, flash sintering is an expedient way to create single-phase, alumina-rich spinel.     

Investigation of structural,optical, and magnetic properties of Nd-doped Sr2SnO4 Ruddlesden Popper oxide

The samples of Sr_2-xNd_xSnO₄ with x = 0, 0.01, 0.02, 0.04, 0.06, and 0.10 were synthesized by a high-temperature solid-state ceramic route. Rietveld refining of X-ray diffraction results showed that all the synthesized compositions are single phase under tetragonal crystal structure. The presence of functional group and local structure has been studied using FTIR and Raman spectroscopy, respectively. XPS study of samples showed the presence of oxygen vacancy and interstitial oxygen in the sample. Optical band gap of samples analyzed by UV-Vis spectra gradually increases with dopant concentration, and Photoluminescence (PL) spectroscopy study showed most intense emission around 1064 nm. Room-temperature magnetic hysteresis curve in sample SSN2 showed ferromagnetism, slowly decreasing with Nd and becoming antiferromagnetic for higher compositions. Utilizing the absorption state observed in PL as metastable state makes it promising candidate for laser and IR detector application and the ferromagnetic/antiferromagnetic nature of sample makes it suitable candidate for spintronics device applications.     

Effect of bacterial inoculum ratio in mixed culture for decolourization and detoxification of pulp paper mill effluent

BACKGROUND: Effluent released from industry is a mixture of various pollutants. For the degradation of complex pollutants, mixed bacterial cultures can be more effective than a single culture. This study investigated the balance of bacterial populations in a mixed culture for maximum reduction of pollutants. RESULTS: This study deals with the degradation and detoxification of pulp paper mill effluent (PPME) by three bacterial strains, i.e. Serratia marcescens, Serratia liquefaciens and Bacillus cereus in different ratios, and found that two ratios, 4:1:1 and 1:4:1, were effective for the degradation of PPME. These ratios reduced the various pollution parameters. Enzyme bioassay revealed that more enzyme was produced during degradation for the ratio 4:1:1. High performance liquid chromatography (HPLC) analysis showed that the ratio 4:1:1 degraded 95% of lignin and related compounds, and chlorophenols up to 98%, whereas ratio 1:4:1 reduced lignin by 84% and chlorophenols by 58% after 7 days incubation. Degradation products were confirmed by gas chromatography–mass spectrometry (GC‐MS) analysis. A seed germination bioassay on Phaseolous mungo L. revealed that toxicity was reduced by the ratio 4:1:1. CONCLUSION: Due to variable potential of different bacteria show variation in their growth pattern at any contaminated site. This study shows that an appropriate ratio of mixed cultures is required for maximum degradation and detoxification of PPME. Copyright © 2012 Society of Chemical Industry     

Physico chemical,microstructural and sensory characteristics of low‐fat meat emulsion containing aloe gel as potential fat replacer

In this study, a possible use of aloe gel (AG) as a potential fat replacer in the manufacture of low‐fat meat emulsion was investigated. The low‐fat meat emulsions with added AG and vegetable oil (VO) in different proportions [AG7.5 (7.5% AG + 7.5% VO); AG5 (5% AG + 10% VO); AG2.5 (2.5% AG + 12.5% VO)] were compared with full‐fat meat emulsion [Control (15% VO only)]. A substantial fat reduction (P < 0.05) up to 50% as compared to full‐fat control meat emulsion was recorded without compromising other sensory attributes of meat emulsion. Microstructural properties as studied by scanning electron microscopy indicated more homogenous regular emulsion matrix with fewer cracks and more regular shaped oil droplets in AG‐added samples than the control samples.     

A hybrid optimization model for proficient bidding strategies with no Karush–Kuhn–Tucker optimality conditions

The computational complexity behind the bi‐level optimization problem has led the researchers to adopt Karush–Kuhn–Tucker (KKT) optimality conditions. However, the problem function has more number of complex constraints to be satisfied. Classical optimization algorithms are impotent to handle the function. This paper presents a simplified minimization function, in which both the profit maximization problem and the ISO market clearance problem are considered, but with no KKT optimality conditions. Subsequently, this paper solves the minimization function using a hybrid optimization algorithm. The hybrid optimization algorithm is developed by combining the operations of group search optimizer (GSO) and genetic algorithm (GA). The hybridization enables the dispersion process of GSO to be a new mutated dispersion process for improving the convergence rate. We evaluate the methodology by experimenting on IEEE 14 and IEEE 30 bus systems. The obtained results are compared with the outcomes of bidding strategies that are based on GSO, PSO, and GA. The results demonstrate that the hybrid optimization algorithm solves the minimization function better than PSO, GA, and GSO. Hence, the profit maximization in the proposed methodology is relatively better than that of the conventional algorithms. Copyright © 2015 John Wiley & Sons, Ltd.     

Dielectric and conducting behavior of pyrene functionalized PANI/P(VDF‐co‐HFP) blend

Herein, we present the dielectric and electrical conductivity properties of the partially miscible polymer blend prepared using pyrene functionalized polyaniline (pf‐PANI) and poly(vinylidene fluoride‐co‐hexafluoro propylene) (PVDF‐co‐HFP). The blend mostly retains the fluorescent nature of pf‐PANI as well as can be moldable and possesses good damping property. The dielectric properties have been investigated as a function of temperature at three different frequencies and the plausible origin of polarization responsible for dielectric behavior in this blend has been identified. The experimental results of dielectric measurements are compared with theoretical models and discussed. The surface morphology of the samples has been examined with a scanning electron microscope. The electrical conductivity has also been studied as a function of temperature and explained in terms of hopping of charge carriers/interconnected networks. The combined dielectric and conductivity results together with scanning electron microscope micrographs, reveal that there is hindrance to achieve percolation threshold even after pf‐PANI addition of 57 vol % and subsequent thermal treatment. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44077.