Synthesis and characterization of niobium doped hexagonal tungsten bronze in the systems,Cs<Subscript>x</Subscript>Nb<Subscript>y</Subscript>W<Subscript>1−y</Subscript>O<Subscript>3</Subscript>

Samples of nominal compositions, Cs_0.25Nb _y W_1−y O₃ and Cs_0.3Nb _y W_1−y O₃ with 0.0 ≤ y ≤ 0.25 and 0.0 ≤ y ≤ 0.3 were synthesized using appropriate amounts of Cs₂WO₄, WO₃ and WO₂ in evacuated and closed silica glass tubes at 800 °C. The polycrystalline products contain hexagonal shaped crystals of up to 15 μm diameter as long as y ≤ 0.15. X-ray powder patterns of the samples reveal the formation of hexagonal tungsten bronze (HTB-I) type phase with y < 0.1. A mixture of HTB-I and an analogous less reduced hexagonal tungsten bronze (HTB-II) type phase is seen when y ≥ 0.1. HTB-II content increases with increasing y, revealing close similarity to bronzoid type phases when y = x. Results of SEM/EDX analysis also support a partial substitution of tungsten by niobium in the HTB-I type phase. Infrared absorption and optical reflectivity data shows the effect of increasing amount of non-metallic phase for y > 0.1 and the effect of counterdoping by Nb⁵⁺/W⁵⁺ substitution in the metallic HTB-I type phase for y ≤ 0.1, respectively. Reinvestigations in the system Rb_0.3Nb _y W_1−y O₃ (0.0 ≤ y ≤ 0.175) show similar results with increasing content of HTB-II type phase related with y.     

A new training strategy for neural network using shuffled frog-leaping algorithm and application to channel equalization

This paper makes use of shuffled frog-leaping algorithm (SFLA) as a training algorithm to train multi-layer artificial neural network (ANN). Next, The SFLA ANNs are used for channel equalization. We, in this paper, also introduce SFLA for channel equalization that is formulated as an optimization problem. In short, this paper introduces a novel strategy for training of ANN and also proposes two novel approaches for channel equalization problem using shuffled frog-leaping algorithm (SFLA). The proposed strategies are tested both in time-invariant and time varying channels and interestingly yield better performance than contemporary approaches as evidenced by simulation results.     

Thin-Layer Drying of Flax Fiber: I. Analysis of Modeling Using Fick's Second Law of Diffusion

Thin-layer drying of moist flax fiber was performed at four temperatures of 30, 50, 70, and 100°C with a constant absolute humidity of 0.0065 kg water per kg dry air. The coefficients of diffusion of the fiber at different drying conditions were estimated by modeling the drying process using the one- to five-term solutions of the second Fick's law of diffusion. The models underestimated the drying process during the initial stages of drying and overestimated this process during the final stages. The estimated coefficient of diffusions ranged from 5.11 × 10^-9 to 1.92 × 10^-8 m²/s and linearly increased with the drying air temperature.     

Bacterial foraging optimisation: Nelder?Mead hybrid algorithm for economic load dispatch

A novel stochastic optimisation approach to solve constrained economic load dispatch problem using hybrid bacterial foraging (BF) technique is presented. in order to explore the search space for finding the local minima of the current location, the simplex algorithm called nelder-mead is used along with BF algorithm. the proposed methodology easily takes care of solving non-convex economic dispatch problems along with different constraints such as transmission losses, dynamic operation constraints (ramp rate limits) and prohibited zones. simulations were performed over various standard test systems with different number of generating units and comparisons are performed with other existing relevant approaches. the findings affirmed the robustness and proficiency of proposed methodology over other existing techniques.     

Development of ultrafine grained Al–Mg–Si alloy with enhanced strength and ductility

The microstructure and mechanical properties of a precipitation hardenable Al–Mg–Si alloy subjected to cryorolling (CR), short annealing and ageing treatments are reported in this present work. The pre-cryorolled solid solution treatment combined with post-CR short annealing (155 °C for 5 min) and then ageing treatment (125 °C for 12 h) has been found to be the optimum processing condition to obtain the ultrafine grained microstructure with substantial improvement of tensile strength (286 MPa) and good tensile ductility (14%) in the Al–Mg–Si alloy. The significant improvement of the mechanical properties of the cryorolled and peak aged 6063 Al alloys have been observed as compared to its bulk alloys in the peak-aged condition (T6).     

Charge-Coupled Memories for Computer Systems

Since their invention in 1970 by Boyle and Smith,^1,2charge-coupled devices (CCD's) have evolved rapidly and are finding wide-ranging applications in three major areas: imaging, memory, and analog signal processing. In this papers, we will primarily concentrate on the memory applications of CCD's.     

Anomaly of arch of atlas--a rare cause of symptomatic canal stenosis in children

Symptomatic canal stenosis at the level of atlas (C1) without atlantoaxial dislocation is thought to be very rare in children. Though common, anomalies of the arch of atlas are generally incidental findings in X-rays. High cord compression due to a narrow canal from a bifid posterior arch, or an absent posterior arch, is a very rare condition. We report 5 children with high cord compression from stenosis of C1 arch.     

Small-angle X-ray scattering studies of a natural fiber: Agave cantala

Summary Agave cantala, a natural fiber is considered as a densely packed colloidal system belonging to the general micelle system and the well known theories of KRATKY and POROD have been utilized to evaluate some macromolecular parameters of the scattering inhomogeneities in it. The small-angle KRATKY Camera of the latest design has been used for experimental measurements. The parameters evaluated are the specific inner surface, transversal lengths like the length of inhomogeneity and the length of coherence and the air fraction of the scattering particles in Agave cantala fiber; these were found to be