Study of the alloying additives and alkaline zincate solution effects on the commercial aluminum as galvanic anode for use in alkaline batteries

The corrosion behavior of different grades of commercial aluminum such as AA1040, AA5083, AA6060 and AA7075 in ZnO-containing 4 M NaOH has been determined by using open circuit potential-time measurements (OCP), galvanostatic and potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The results of scanning electron microscopy (SEM) and energy dispersive analysis of X-ray (EDAX) reveal that ZnO produces the inhibition effect by the formation of a zinc-containing deposit layer on the surface of aluminum electrodes. Although the influence of zincating on the performance of aluminum alloys and considering the amount of alloying elements such as zinc, magnesium and manganese in AA7075 and AA5083 alloys is much more than AA6060 one, the AA6060 aluminum exhibits negligible corrosion rate. Alloying aluminum with other elements and modifying the composition of the electrolyte is a necessary condition for reducing the self-corrosion of the aluminum anodes, whereas the proportion of the amount of additive elements is sufficient and important condition. As AA6060 with a low amount of Zn and Mg, but the high value of the ratio of (Mg/Zn) content (>400) can serve as a good galvanic anode in the alkaline media.     

Effect of Geometry, Joule Heating, and Critical Current on the Responsivity of MOD Superconducting Transition Edge Sensors

By fabrication of several bolometric detectors on the YBCO film made of Metal-Organic Deposition (MOD) and the effect of pattering and film parameters on the optical responsivity of transition edge sensors is investigated. The low cost nonfluorine (MOD) method has been applied to fabricate YBCO thin films with different patterning parameters. The measurement results of the optical responsivity versus modulation frequency up to 100 KHz for these devices are reported.     

Model-based identification of damage from sparse sensor measurements using Neumann series expansion

This paper presents a novel and effective modal data-based methodology for structural damage localization and quantification when the structure is equipped with a limited number of sensors. Damage detection problem is defined as an inverse model-based problem and a new damage-sensitive cost function is introduced using calculated Generalised Flexibility Matrix and Modal Assurance Criterion. The second-order approximation of Neumann Series Expansion-based Model Reduction approach is employed for numerically simulation of sparse sensor installation. Finally, a hybrid version of two different evolutionary optimization algorithms, named Particle Swarm Optimization–Colonial Competitive Algorithm (PSO–CCA), is suggested and utilized for solving optimization problem. This hybridization, not only can pick the positive points of the PSO and CCA for searching complex solution domain, but also can lead to achieving a powerful, fast speed optimization strategy. The efficiency of the presented method is demonstrated by studying three numerical examples under different damage patterns. Various challenges, such as the robustness of the method in the presence of random noises in the input data, are investigated. The obtained results introduce the presented method as a viable and practical strategy for structural damage identification, especially when a limited number of sensors are installed on the structure.     

Partial Oxidation of Propane Over Mo1V0.3Te0.23Nb0.12Ox Catalyst in a Fluidized Bed Reactor

A fluidized bed reactor, for the first time, was employed to investigate the partial oxidation of propane to acrylic acid over Mo₁V_0.3Te_0.23Nb_0.12O_x catalyst. Effects of temperature, oxygen concentration, steam concentration, space velocity, and dilution with different sizes of SiC were studied and discussed. The reaction in the fluidized bed was compared with the reaction in the classical fixed bed. The results indicated that at constant temperature propane conversion obtained in the fixed bed reactor was higher. But the fluidized bed recompensed it by higher acrylic acid selectivity leading to acrylic acid yields and formation rates considerably over the fixed bed. In the fluidized bed reactor, an enhancement in the acrylic acid selectivity was observed over fixed bed at similar conversions. It is suggested that passing a large portion of gas phase oxygen through bubbles allows operation under lower oxygen partial pressure, which favors the desired reaction path. With the heat sink feature of the diluent, the catalytic performance is more influenced by dilution in the fixed bed. However, hot spots are less likely to occur in the fluidized bed and dilution has little effect on the catalytic performance. However, propane conversion increases slightly by increasing SiC particle diameter due to better fluidization quality.     

A Quasi-Exact Dynamic Finite Element for Free Vibration Analysis of Sandwich Beams

A Dynamic Finite Element (DFE) model for the vibration analysis of three-layered sandwich beams is presented. The governing differential equations of motion of the sandwich beam for the general case, when the properties of each layer are dissimilar, are exploited. Displacement fields are imposed such that the face layers follow the Rayleigh beam assumptions, while the core is governed by Timoshenko beam theory. The DFE model is then used to examine the free-vibration characteristics of an asymmetric soft-core sandwich beam with steel face layers and a rubber core. The natural frequency results for the first four modes, in this case, show the exact match between the DFE and ‘exact’ Dynamic Stiffness Matrix (DSM) formulations, using only a one-element mesh, justifying the use of Quasi-Exact (QE-DFE) title. Convergence-wise, the QE-DFE formulation also outperforms the conventional FEM, which makes it useful in benchmarking other studies or the examination of high frequency response where FEM requires the use of large number of elements in order to achieve better accuracy. The application of the DFE to a lead-core sandwich beam is also discussed.     

Antimicrobial Activity of Pomegranate (Punica granatum L.) Peel Extract,Physical, Mechanical,Barrier and Antimicrobial Properties of Pomegranate Peel Extract‐incorporated Sodium Caseinate Film and Application in Packaging for Ground Beef

In the present study, casein‐based edible films containing 1, 1.5 or 2 times of minimum inhibitory concentration of pomegranate peel extract (as antimicrobial agent) were prepared, and their physical, mechanical and antimicrobial impacts against two Gram‐positive and Gram‐negative bacterial strains were investigated. To evaluate the microstructure changes resulting from the addition of the antimicrobial extracts, scanning electron microscopy images were taken from both surface and cross section of the films. Different physical and mechanical properties of films were affected by the addition of pomegranate extract. For example, the water vapour permeability of films increased. Antimicrobial effectiveness of prepared films was more pronounced against Gram‐positive strain compared with Gram‐negative strain. Antimicrobial impact of edible films was also studied on ground meat. It was observed that antimicrobial activity of the films was mostly dependent on the types of microorganisms present in meat. Although they were not a suitable replacement for common films, they could substantially extend the shelf life of ground meat. Copyright © 2015 John Wiley & Sons, Ltd.     

Acoustic scattering of spherical waves incident on a long fluid-saturated poroelastic cylinder

Acoustic scattering of spherical waves generated by a monopole point source in a perfect (inviscid and ideal) compressible fluid by a fluid-saturated porous cylinder of infinite length is studied theoretically in the present study. The formulation utilizes the Biot theory of dynamic poroelasticity along with the appropriate wave-field expansions, the translational addition theorem for spherical wave functions, and the pertinent boundary conditions to obtain a closed-form solution in the form of infinite series. The analytical results are illustrated with a numerical example in which a monopole point source within water is located near a porous cylinder with a water-saturated Ridgefield sandstone formation. The numerical results reveal the effects of source excitation frequency, the cylinder interface permeability condition, and the location of the point source and the field point on the backscattered pressure magnitudes. Limiting cases are considered, and the obtained numerical results are validated by already well-known solutions.     

A SEU-protected cache memory-based on variable associativity of sets

SRAM cache memories suffer from single event upset (SEU) faults induced by energetic particles such as neutron and alpha particles. To protect these caches, designers often use error detection and correction codes, which typically provide single-bit error detection and even correction. However, these codes have low error detection capability or incur significant performance penalties. In this paper, a protected cache scheme based on the variable associativity of sets is presented. In this scheme, cache space is divided into sets of different sizes with variable tag field lengths. The other remained bits of tags are used for protecting the tag using a new protection code. This leads to protect the cache without compromising performance and area with respect to the similar one, fully associative cache. The scheme provides high SEU detection coverage as well as high performance. Moreover, reliability and mean-time-to-failure (MTTF) equations are derived and estimated. The results obtained from fault injection experiments and several trace files from SPEC2000 reveal that the proposed scheme exhibits a good performance near to fully associative cache but can detect high percent of SEU faults.