Hybrid Technique Based Harmonic Elimination of the Thirty-One Level Multi Level Inverter

Wireless Personal Communications - The paper suggests an intelligent control method for extracting multi-level inverter (MLI) harmonics. The hybrid control technology combines the Whale...     

Broadcasting with Controlled Redundancy and Improved Localization in Wireless Sensor Networks

Wireless sensor networks （WSNs） consist of sensor nodes that broadcast a message within a network. Efficient broadcasting is a key requirement in sensor networks and has been a focal point of research over the last few years. There are many challenging tasks in the network, including redundancy control and sensor node localization that mainly depend on broadcasting. In this paper, we propose a broadcasting algorithm to control redundancy and improve localization （BACRIL） in WSNs. The proposed algorithm incorporates the benefits of the gossip protocol for optimizing message broadcasting within the network. Simulation results show a controlled level of redundancy, which is up to 57.6% if the number of sensor nodes deployed in a 500 m×500 m area are increased from 50 to 500.     

On wave modulation by a rotating object

When a time harmonic electromagnetic wave is incident upon a rotating object which is not rotationally symmetric about the axis of rotation, modulation in the secondary waves generally will occur. Two scattering and reflection problems where, under certain conditions, no modulation occurs, are discussed. In the first case, a transverse electric (TE) or transverse magnetic (TM) wave is incident upon an object inside a circular waveguide. The object is rotating about the axis of the waveguide and has periodic characterisitcs in the azimuthal direction with period2pi/N(N: an integer). In the second case, the waveguide is removed, and a linearly polarized plane wave is incident upon the object along its axis of rotation.     

Uptake of permanganate from aqueous environment by surfactant modified montmorillonite batch and fixed bed studies

Organo-clay was prepared by incorporating different amounts (in terms of CEC, ranging from 134?C840 mg of quaternary ammonium cation (QACs) such as hexadecytrimethylammonium bromide ([C₁₉H₄₂N]Br) into the montmorillonite clay. Prepared organo-clays are characterized by CHN analyser and XRD to measure the amount of elemental content and interlayer spacing of surfactant modified clay. The batch experiments of sorption of permanganate from aqueous media by organo-clays was studied at different acidic strengths (pH 1?C7). The experimental results show that the rate and amount of adsorption of permanganate was higher at lower pH compared to raw montmorillonite. Laboratory fixed bed experiments were conducted to evaluate the breakthrough time and nature of breakthrough curves. The shape of the breakthrough curves shows that the initial cationic surfactant loadings at 1??0 CEC of the clay is enough to enter the permanganate ions in to the interlamellar region of the surfactant modified smectile clays. These fixed bed studies were also applied to quantify the effect of bed-depth and breakthrough time during the uptake of permanganate. Calculation of thermodynamic parameters shows that the sorption of permanganate is spontaneous and follows the first order kinetics.     

Stochastic make-to-stock inventory deployment problem: an endosymbiotic psychoclonal algorithm based approach

Integrated steel manufacturers (ISMs) have no specific product, they just produce finished product from the ore. This enhances the uncertainty prevailing in the ISM regarding the nature of the finished product and significant demand by customers. At present low cost mini-mills are giving firm competition to ISMs in terms of cost, and this has compelled the ISM industry to target customers who want exotic products and faster reliable deliveries. To meet this objective, ISMs are exploring the option of satisfying part of their demand by converting strategically placed products, this helps in increasing the variability of product produced by the ISM in a short lead time. In this paper the authors have proposed a new hybrid evolutionary algorithm named endosymbiotic-psychoclonal (ESPC) to decide what and how much to stock as a semi-product in inventory. In the proposed theory, the ability of previously proposed psychoclonal algorithms to exploit the search space has been increased by making antibodies and antigen more co-operative interacting species. The efficacy of the proposed algorithm has been tested on randomly generated datasets and the results compared with other evolutionary algorithms such as genetic algorithms (GA) and simulated annealing (SA). The comparison of ESPC with GA and SA proves the superiority of the proposed algorithm both in terms of quality of the solution obtained and convergence time required to reach the optimal/near optimal value of the solution.     

Green synthesis of copper oxide nanoparticles and its effective applications in Biginelli reaction,BTB photodegradation and antibacterial activity

Metal/metal oxide nanoparticles have gained much attention in the field of organic catalysis and photocatalysis reactions for development of greener methodology. In the present work, copper oxide nanoparticles (CuO NPs) were synthesized by a greener route using Cordia sebestena (C. sebestena) flower aqueous extract. The nanoparticles were evaluated for their catalytic efficiency. The green synthesized CuO NPs were characterized using various analytical studies. A UV–Visible spectrum with peak at 267?nm and the peaks in their FT-IR spectrum at 431 and 542?cm^?1 showed reduction by the plant metabolites. FESEM-EDX analysis of CuO NPs shows an agglomerated spherical shape with signatures of Cu and O and XRD reveals characteristic crystallinity. TEM and DLS analyses showed particle size between 20 and 35?nm and TEM-SAED pattern ensured crystallinity. A Zeta potential of ?26?mV demonstrates moderate stability. The CuO NPs acted as a catalyst in the Biginelli reaction to produce 3,4-dihydropyrimidinones rapidly and at high yield. The NPs also degraded bromothymol blue (BTB) by photocatalysis with hydrogen peroxide. 100% dye removal efficiency was achieved by 3?h exposure of BTB to natural sunlight inferring it as economy, ecofriendly and effective catalyst. This finding illustrates that the NPs could be used in photolysis to remove water pollutants. Moreover, the biological significance of green synthesized CuO NPs was assessed by antibacterial activity against selected pathogenic bacterial organisms.     

Respiratory health problems associated to infrastructural development among residents living near Special Economic Zone in India

A cross-sectional study was undertaken to assess the lung function status of residents living in areas adjacent to Noida Special Economic Zone (NSEZ). The survey included 161 subjects (Bhangal = 79, Bakhtiyarpur = 48, and Hazipur = 34) and 104 subjects from a non-industrial zone. The study showed a significantly high prevalence of lung function impairment (17.7%) amongst residents living adjacent to Special Economic Zone (Bhangal) compared with residents of non-industrial zone. Breathlessness and cough was more prevalent amongst residents of Bhangal. It was found that lung function deficits amongst residents and distance from NSEZ were inversely related. Lung function abnormalities were found to be at maximum in Bhangal at 1-km distance, moderate in Hazipur at 2-km distance and minimum in Bhaktiyarpur at 3-km distance. At all three locations adjacent to NSEZ, particulate matter (PM) concentration showed suspended particulate matter (SPM) and respirable suspended particulate matter (RSPM) above the prescribed limits of national ambient air quality standard; concentration of PM with an aerodynamic diameter ≤ 2.5 μm (PM_2.5) and PM with an aerodynamic diameter ≤ 1 μm (PM₁) was also higher than the control area. Construction activities related to infrastructural development and increased vehicular traffic may be responsible for higher concentrations of PM_2.5, PM₁, RSPM and SPM in these areas.     

Reliability‐based robust design optimization: A multi‐objective framework using hybrid quality loss function

In this globally competitive business environment, design engineers are constantly striving to establish new and effective tools and techniques to ensure a robust and reliable product design. Robust design (RD) and reliability‐based design approaches have shown the potential to deal with variability in the life cycle of a product. This paper explores the possibilities of combining both approaches into a single model and proposes a hybrid quality loss function‐based multi‐objective optimization model. The model is unique because it uses a hybrid form of quality loss‐based objective function that is defined in terms of desirable as well as undesirable deviations to obtain efficient design points with minimum quality loss. The proposed approach attempts to optimize the product design by addressing quality loss, variability, and life‐cycle issues simultaneously by combining both reliability‐based and RD approaches into a single model with various customer aspirations. The application of the approach is demonstrated using a leaf spring design example. Copyright © 2009 John Wiley & Sons, Ltd.     

Erosion behaviour of hydro turbine steels

The martensitic stainless steel (termed as 13/4) is currently being used for fabrication of underwater parts in hydroelectric projects. There are, however, several maintenance problems associated with the use of this steel. A nitronic steel (termed as 21-4-N) has been developed as an alternative with the specific aim of overcoming these problems. A comparative study has been made on the erosion behaviour of 13/4 and 21-4-N steels by means of solid particle impingement using gas jet. The eroded surfaces after erosion tests were analysed by scanning electron microscopy. It is observed that the 21-4-N nitronic steel possesses better resistance to erosion in comparison to 13/4 martensitic stainless steel. The austenitic matrix of the nitronic steel possesses high hardness, high tensile toughness and work hardening ability, which results in higher erosion resistance.     

On the Presence of Cu1+ in the Superconducting (Hg,M)Sr2CuO4+δ; M = Cr, Mo, or Re

The Cu K-edge measurements on the optimum T _c 1201 compounds (Hg_1?x M _x )Sr₂CuO_4+δ (M = Cr, Mo, or Re; 0.10 ≤ x ≤ 0.30) show besides Cu²⁺ (predominant) a very weak but distinct signature of Cu¹⁺, only in the superconducting (SC) samples. The Cu¹⁺ feature is conspicuously absent when these compositions are non-superconducting because of different processing conditions. Our finding of monovalent Cu in SC (Hg,M)/Sr-1201 favors the presence of Cu at the Hg-site and this seems to facilitate superconductivity in these cuprates.