Thermal,Microstructural, Magnetic,and Optical Studies for La0.7M0.3CoO3 (M = Ca,Pb) Cobaltites for Potential Magneto-optical Applications

Journal of Superconductivity and Novel Magnetism - In this work, the thermal, microstructural, magnetic, and optical studies for both La0.7Ca0.3CoO3 (LCCO) and La0.7Pb0.3CoO3 (LPCO) cobaltite...     

Structural,dielectric and electrical properties of Sol–gel auto-combustion technic of CuFeCr0.5Ni0.5O4 ferrite

Journal of Materials Science - The CuFeCr0.5Ni0.5O4 (CFO) compound was synthesized using sol–gel reaction combustion technic. The structural analysis showed that the obtained composites have...     

Searching for knee regions of the Pareto front using mobile reference points

Evolutionary Algorithms (EAs) have been recognized to be well suited to approximate the Pareto front of Multi-objective Optimization Problems (MOPs). In reality, the Decision Maker (DM) is not interested in discovering the whole Pareto front rather than finding only the portion(s) of the front that matches at most his/her preferences. Recently, several studies have addressed the decision-making task to assist the DM in choosing the final alternative. Knee regions are potential parts of the Pareto front presenting the maximal trade-offs between objectives. Solutions residing in knee regions are characterized by the fact that a small improvement in either objective will cause a large deterioration in at least another one which makes moving in either direction not attractive. Thus, in the absence of explicit DM’s preferences, we suppose that knee regions represent the DM’s preferences themselves. Recently, few works were proposed to find knee regions. This paper represents a further study in this direction. Hence, we propose a new evolutionary method, denoted TKR-NSGA-II, to discover knee regions of the Pareto front. In this method, the population is guided gradually by means of a set of mobile reference points. Since the reference points are updated based on trade-off information, the population converges towards knee region centers which allows the construction of a neighborhood of solutions in each knee. The performance assessment of the proposed algorithm is done on two- and three-objective knee-based test problems. The obtained results show the ability of the algorithm to: (1) find the Pareto optimal knee regions, (2) control the extent (We mean by extent the breadth/spread of the obtained knee region.) of the obtained regions independently of the geometry of the front and (3) provide competitive and better results when compared to other recently proposed methods. Moreover, we propose an interactive version of TKR-NSGA-II which is useful when the DM has no a priori information about the number of existing knees in the Pareto optimal front.     

Optical gain calculation of mid-infrared InAsN/GaSb quantum-well laser for tunable absorption spectroscopy applications

We report on optical gain calculations of a dilute-nitride mid-infrared laser structure designed to be grown on InAs substrate. The active region is composed of several strain-compensated type-II “W”-like InAsN/GaSb/InAsN quantum wells adapted to operate near 3.3 μm at room temperature. For typical injected carrier density σ = 1.1012 cm^− 2, the theoretical laser structure performances reveal a gain value at around 1000 cm^− 1 at 300 K, inducing a modal gain value equal to 50 cm^− 1. Low radiative current densities lower than 100 A/cm² are predicted, indicating that this dilute-nitride structure could operate at 300 K with small threshold current density.     

Nanoarchitectonics of Ba0.97La0.02Ti1-xNb4x/5O3 (x = 0.00 and 0.10) polycrystalline compounds with electrical and optical properties

Journal of Materials Science: Materials in Electronics - A lead-free solid solution, of a composition Ba0.97La0.02Ti1-xNb4x/5O3 (for x?=?0.00 and 0.10) (noted BLT, BLT0.9Nb0.08), was...     

Mixed Valence Perovskite Cs2Au2I6: A Potential Material for Thin‐Film Pb‐Free Photovoltaic Cells with Ultrahigh Efficiency

New light is shed on the previously known perovskite material, Cs₂Au₂I₆, as a potential active material for high‐efficiency thin‐film Pb‐free photovoltaic cells. First‐principles calculations demonstrate that Cs₂Au₂I₆ has an optimal band gap that is close to the Shockley–Queisser value. The band gap size is governed by intermediate band formation. Charge disproportionation on Au makes Cs₂Au₂I₆ a double‐perovskite material, although it is stoichiometrically a single perovskite. In contrast to most previously discussed double perovskites, Cs₂Au₂I₆ has a direct‐band‐gap feature, and optical simulation predicts that a very thin layer of active material is sufficient to achieve a high photoconversion efficiency using a polycrystalline film layer. The already confirmed synthesizability of this material, coupled with the state‐of‐the‐art multiscale simulations connecting from the material to the device, strongly suggests that Cs₂Au₂I₆ will serve as the active material in highly efficient, nontoxic, and thin‐film perovskite solar cells in the very near future.     

Heat inactivation of Listeria monocytogenes and Salmonella enterica serovar Typhi in a typical bologna matrix during an industrial cooking-cooling cycle

The heat resistance of Salmonella enterica serovar Typhi PF-724 and Listeria monocytogenes 2812 was determined in a commercial bologna batter. The heat inactivation of the two bacterial species was also studied in a semiautomatic pilot smokehouse under cooking conditions that reproduced an industrial bologna process. S. enterica serovar Typhi PF-724 was less heat resistant than L. monocytogenes 2812. The D-values (times required to reduce the population by 1 logarithmic cycle) for S. enterica serovar Typhi PF-724 ranged from 10.11 to 0.04 min for temperatures of 50 to 70 degrees C, while for L. monocytogenes 2812, the D-values were 2.5-, 4.9-, 3.8-, 3.3-, and 2-fold higher at 50, 55, 60, 65, and 70 degrees C, respectively, than for S. enterica serovar Typhi PF-724. However, the z-value (temperature required to reduce log D by 1 logarithmic cycle) for S. enterica serovar Typhi PF-724 (5.72 degrees C) was not significantly different from the z-value for L. monocytogenes 2812 (7.04 degrees C), indicating that a given increase in temperature would have a similar effect on the decimal reduction time for both bacterial species in that meat emulsion. Our data on experimentally inoculated batter also showed that processing bologna at a cooking-cooling cycle commonly used in the industry resulted in a minimum 5-log reduction for both S. enterica serovar Typhi PF-724 and L. monocytogenes 2812.     

Feature construction as a bi-level optimization problem

Neural Computing and Applications - Feature selection and construction are important preprocessing techniques in data mining. They allow not only dimensionality reduction but also classification...