On emulated nonlinear reduced-order observers for networked control systems

We consider a general class of nonlinear reduced-order observers and show that the global asymptotic convergence of the observation error in the absence of network-induced constraints is maintained for the emulated observer semiglobally and practically (with respect to the maximum allowable transmission interval) when system measurements are sent through a communication channel. Networks governed by a Lyapunov uniformly globally asymptotically stable protocol are investigated. Our results can be used to synthesize various observers for networked control systems for a range of network configurations, as we illustrate it by considering classes of immersion and invariance observers which include the circle-criterion observers.     

Influence of thermal treatment on structure and microhardness of Fe75Ni2Si8B13C2 amorphous alloy

Correlation between hardness of amorphous Fe₇₅Ni₂Si₈B₁₃C₂ alloy and thermally induced structural transformations has been investigated by measuring microhardness in a series of samples heated at different temperatures from 25 to 1000 °C. The alloy has a relatively high hardness in the amorphous state, due to its chemical composition involving silicon, boron and carbon. As the alloy begins to crystallize, microhardness increased and reached a plateau in 500–650 °C temperature region, due to formation composite structure involving the small nanocrystals of α-Fe(Si) and Fe₂B phases dispersed in the amorphous matrix. After treatment at higher temperatures, the nanocomposite structure is replaced by a more granulated structure, leading to decline in microhardness.     

The p-hub Model with Hub-catchment Areas,Existing Hubs,and Simulation: A Case Study of Serbian Intermodal Terminals

This paper addresses the problem of optimally locating intermodal freight terminals in Serbia. To solve this problem and determine the effects of the resulting scenarios, two modeling approaches were combined. The first approach is based on multiple-assignment hub-network design, and the second is based on simulation. The multiple-assignment p-hub network location model was used to determine the optimal location of intermodal terminals. Simulation was used as a tool to estimate intermodal transport flow volumes, due to the unreliability and unavailability of specific statistical data, and as a method for quantitatively analyzing the economic, time, and environmental effects of different scenarios of intermodal terminal development. The results presented here represent a summary, with some extension, of the research realized in the IMOD-X project (Intermodal Solutions for Competitive Transport in Serbia).     

Improvement of the corrosion characteristics of 1.4713 ferritic steel in 0.1 M sulfuric acid by heat treatment and Al2O3–TiO2 coating

This study addresses the influence of heat treatment and alumina coating on the corrosion of EN 1.4713 steel in 0.1 mol dm⁻³ sulfuric acid. The corrosion characteristics of three different samples are examined using the open circuit potential measurements, Tafel extrapolation, linear polarization resistance, weight-loss method, and electrochemical impedance spectroscopy. The results showed that the application of the weight-loss method yielded similar values to the electrochemical method in the first 24 h. A decrease in corrosion rate, in a similar manner, was observed for all three samples. The largest deacceleration was obtained for the alumina/titania-coated sample. It was obtained that the heat treatment significantly increased the corrosion resistance, but only in the first 24 h. The alumina/titania coating decreases the corrosion rate by approximately 30 times at the beginning of the corrosion exposure and by nearly 300 times after 240 h. This coating could have a significant influence on construction design, which uses ferritic stainless steel as the material.     

Effect of Pulsed Light Treatment on the Germination of Bacillus subtilis Spores

Food and Bioprocess Technology - The loss of cell culturability (spore counts), spore germination and subsequent vegetative growth of Bacillus subtilis were evaluated after pulsed light (PL)...     

Self-assembled polyaniline 12-tungstophosphate micro/nanostructures

Polyaniline (PANI) micro/nanostructures were synthesized by the external-template-free oxidative polymerization of aniline in aqueous solution of 12-tungstophosphoric acid (WPA), using ammonium peroxydisulfate (APS) as an oxidant and starting the oxidation of aniline from slightly acidic media (pH 5.4–5.9). The effect of the initial weight ratio of WPA to aniline on molecular structure, morphology, and physicochemical properties of polyaniline 12-tungstophosphate (PANI-WPA) was investigated by FTIR, Raman and inductively coupled plasma optical emission (ICP-OES) spectroscopies, elemental analysis, X-ray powder diffraction (XRPD), scanning and transmission electron microscopies (SEM and TEM), thermogravimetric analysis (TGA), differential thermal analysis (DTA), and conductivity measurements. The morphological change of polymerization products during a single polymerization process, from non-conducting submicro-/microspherical oligoaniline intermediates to semiconducting PANI-WPA consisted of self-assembled nanotubes and/or nanorods co-existing with submicro-/microspheres, has been revealed by SEM and TEM. The average diameter of nanorods in PANI-WPA samples decreased with increasing the initial WPA/aniline weight ratio. The incorporation of 12-tungstophosphate counter-ions into PANI matrix has been proved by FTIR, Raman and ICP-OES spectroscopies, TGA and DTA analysis. Electrical conductivity of PANI-WPA increased in the range (2.5–5.3) × 10^?3 S cm^?1 with the increase of the initial WPA/aniline weight ratio. The presence of branched structures and phenazine units besides the ordinary paramagnetic and diamagnetic emeraldine salt structural features in PANI-WPA was proved by FTIR and Raman spectroscopies.