Superconducting Bearing Design for Outer Rotor Flywheel Using Lumped Parameter Techniques

This paper describes the application of lumped parameter modeling techniques to designing high temperature superconducting bearings for outer-rotor flywheel energy storage systems. The lumped parameter models decrease computational time by 99% compared to Finite Element Analysis (FEM) without compromising fidelity needed to capture the non-linear and hysteretic force-displacement behavior between a levitated permanent magnet and bulk superconductor. The techniques formulated can be used to quickly evaluate lifting capacity and translational stiffness for a superconducting bearing design. The validity of the modeling approach has been verified by comparing results from FEM studies and experimental tests.Center for Electromechanic

Design and Analysis of Slit-cut Stacked Equilateral Triangular Microstrip Patch Antenna

In this paper, a novel structure of slit-cut stacked equilateral triangular microstrip antenna (ETMA) has been theoretically studied using cavity model and found in agreement with the stimulated result calculated by high frequency simulator structure (HFSS). The analysis of stacked ETMA and slit-cut ETMA is done. The theoretical and simulated results of stacked ETMA and slit-cut ETMA are presented and compared. The main concentration is to find the different results, i.e. input impedance and return loss of the slit-cut ETMA and slit-cut stacked ETMA.Defence Science Journal, Vol. 65, No. 3, May 2015, pp.240-244, DOI: http://dx.doi.org/10.14429/dsj.65.797

PRELIMINARY PHYTOCHEMICAL AND ANTIBACTERIAL STUDIES ON LEAF EXTRACTS OF ALTERNANTHERA BRASILIANA (L.) KUNTZE

Objectives: The present study was to study the phytochemical and antibacterial properties of Alternanthera brasiliana leaf extracts using three different solvents (hexane, chloroform and methanol) against human pathogenic microorganism. Methods: Preliminary phytochemical screening of leaf extracts (in different solvents) of A. brasiliana were qualitatively tested using standard procedures. Thin Layer Chromatography (TLC) was performed to detect the phytochemical compounds present in A. brasiliana. Antibacterial activity of crude extract was determined by disc diffusion method. Minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were also performed for the hexane extract. Results: The preliminary qualitative phytochemical screening of hexane extracts revealed the presence of alkaloids, phenols, flavonoids, saponins, tannins, phytosterols and carbohydrates. In chloroform and methanolic extracts, all the tested phytochemicals were present except flavanoids and saponins. Alkaloids were not present in the chloroform extract. TLC analysis revealed the presence of seven compounds with Rf values ranging from 0.173 to 0.933. Promising antibacterial activity was observed in the hexane extract with an inhibition zone of 22 mm against E. coli. Chloroform and methanolic extracts showed negligible antibacterial activities. Conclusion: The results revealed that the hexane leaf extract of A. brasiliana alone exhibited potential antibacterial activity specifically against pathogenic E. coli (MTCC 729)

Using Fuzzy Logic for Performance Evaluation in Reinforcement Learning

Current reinforcement learning algorithms require long training periods which generally limit their applicability to small size problems. A new architecture is described which uses fuzzy rules to initialize its two neural networks: a neural network for performance evaluation and another for action selection. This architecture is applied to control of dynamic systems and it is demonstrated that it is possible to start with an approximate prior knowledge and learn to refine it through experiments using reinforcement learning

Practice of wastewater irrigation and its impacts on human health and environment: a state of the art

The practice of wastewater irrigation lessens the pressure on the aquatic environment by minimizing the use of freshwater resources. However, this may lead to significant damage to the human health and environments. Recycled wastewater possesses a substantial amount of nutrients that act as fertilizers for crops and facilitate the metabolic action of microorganisms. The major advantages of wastewater irrigation are increased agricultural production, nutrient recycling, reduced stress on freshwater, economical support and provision of livelihoods for farmers. However, several harmful impacts of wastewater irrigation are also prominent due to inappropriate wastewater management and irrigation practices. These include severe hazards to farmer’s health, contamination of agricultural land and crops with toxic metals, chemical compounds, salts and microbial pathogens. In addition, long-term irrigation using wastewater can significantly affect the groundwater through leakage of salty and toxic metal-rich wastewater making it unfit for human consumption. Wastewater irrigation may also alter the physicochemical properties and microbiota of soil, which in turn can disturb land fertility and crop productivity. Several factors need to be considered while using treated or partially treated wastewater for irrigation such as diversity and type of pollutants, available nutrients, pathogenic microorganisms and soil salinity. In this review paper, we assess the impact of wastewater irrigation on humans as well as on the environment based on available case studies globally, outline current use of wastewater for irrigation of agricultural crops such as cereals, vegetables, fodder crops, including agroforestry and discuss suitable management practices of wastewater reuse for irrigation

Non-linear IVIV characteristics in two-dimensional superconductors: Berezinskii-Kosterlitz-Thouless physics vs inhomogeneity

One of the hallmarks of the Berezinskii-Kosterlitz-Thouless (BKT) transition in two-dimensional (2D) superconductors is the universal jump of the superfluid density, that can be indirectly probed via the non-linear exponent of the current-voltage $IV$ characteristics. Here, we compare the experimental measurements of $IV$ characteristics in two cases, namely NbN thin films and SrTiO$_3$-based interfaces. While the former display a paradigmatic example of BKT-like non-linear effects, the latter do not seem to justify a BKT analysis. Rather, the observed $IV$ characteristics can be well reproduced theoretically by modelling the effect of mesoscopic inhomogeneity of the superconducting state. Our results offer an alternative perspective on the spontaneous fragmentation of the superconducting background in confined 2D systems.Comment: Final version, as publishe