Dual Estimation of Fractional Variable Order Based on the Unscented Fractional Order Kalman Filter for Direct and Networked Measurements

The paper is devoted to variable order estimation process when measurements are obtained in two different ways: directly and by lossy network. Since the problem of fractional order estimation is highly nonlinear, dual estimation algorithm based on Unscented Fractional Order Kalman filter has been used. In dual estimation process, state variable and order estimation have been divided into two sub-processes. For estimation state variables and variable fractional order, the Fractional Kalman filter and the Unscented Fractional Kalman filter have been used, respectively. The order estimation algorithms were applied to numerical examples and to real fractional variable order inertial system realized as an analog circuit.     

Complex variable step method for sensitivity analysis of effective properties in multi-field micromechanics

This paper shows an approach to computing the effective properties of multi-field composite materials and their first-order sensitivities. The approach is based on the application of the complex variable step method for the micromechanical Mori–Tanaka scheme; hence, the first-order sensitivities can be computed in the same analysis. Numerical results are presented for magnetoelectroelastic properties of piezoelectric–piezomagnetic composite materials. A comparison of the results to those obtained by other methods shows that the presented sensitivity analysis gives highly accurate and stable results, but the values of the results are dependent on the applied micromechanical model. The presented approach may be used to solve ill-posed problems of optimal design or identification in coupled fields micromechanics.     

31P CSI of the human brain in healthy subjects and tumor patients at 9.4 T with a three-layered multi-nuclear coil: initial results

Magnetic Resonance Materials in Physics, Biology and Medicine - Investigation of the feasibility and performance of phosphorus (31P) magnetic resonance spectroscopic imaging (MRSI) at 9.4 T with a...     

Magnetic-aligned,magnetite-filled epoxy composites with enhanced thermal conductivity

This paper investigates the influence of magnetic field-assisted filler alignment technology on the morphology and the thermal conductivity of magnetite-filled epoxy composites. A magnetic field was applied during the solidification of the composite in order to change the position of the filler and its distribution in the polymer matrix. It is shown that the applied procedure leads to the filler being oriented along the direction of the magnetic field, and as a result, the thermal conductivity is improved by up to 120 % compared to a composite with randomly oriented filler obtained without the assistance of a magnetic field. This positive effect is caused by the appearance of conductive paths at a much lower content of the filler when the composite solidification is assisted by a magnetic field, relative to an equivalent isotropic sample. These morphological changes were confirmed by microscopic and X-ray microtomography imaging. The temperature dependences of thermal conductivity were also investigated over a broad temperature range for a magnetite-filled epoxy composite sample and compared to the bulk magnetite reference, showing that thermal behaviour of the magnetite-filled composite is stable, which is a promising result when considering the future application of the technology.     

Investigations of chromium (VI) ion sorption and reduction on strongly basic anion exchanger

Removal of chromium(VI) ions and their reduction were studied on the anion exchanger Dowex PSR-2 in the pH range from 1.5 to 10. The parameters of Cr(VI) sorption process on the anion exchanger were calculated based on the most popular isotherm models such as: Freundlich, Langmuir, Temkin, and Dubinin–Radushkevich (D-R). The Langmuir isotherm was the most appropriate to describe Cr(VI) sorption. The Cr(VI) uptake by Dowex PSR-2 was found to follow the pseudo-second-order rate kinetics. Reduction of chromium(VI) in the pH range 1.5–10 was observed using the HPLC-ICP-MS (high-performance liquid chromatography–inductively coupled plasma-mass spectrometry) method. Oxidation of tri-n-butyl quaternary ammonium groups during the chromate (VI) removal process was observed.     

Effect of CO<Subscript>2</Subscript> addition on lignite gasification in a CFB reactor: A pilot-scale study

The addition of carbon dioxide to the gasification media during lignite gasification is introduced. The paper presents thermodynamic grounds of CO₂ enhanced gasification using a simplified equilibrium model. Experimental tests conducted using a pilot-scale circulating fluidized bed gasifier are discussed. Detailed analysis of the CO₂/C ratio on process conditions, namely on the process gas composition, lower heating value and H₂/CO ratio, is provided. Process gas composition implies that the gas is suitable for heat and power generation. Alternatively, CO₂ enhanced gasification could be considered as a carbon capture and utilization technology when external, renewable heat supply to the process is used. The results thus obtained are the initial step toward development of the CO₂ enhanced gasification process.     

A methodology for implementation of mobile robot in adaptive manufacturing environments

With the rapid development of technologies, many production systems and modes has been advanced with respect to manufacturing, management and information fields. The paper deals with the problem of the implementation of an autonomous industrial mobile robot in real-world industrial applications in which all these fields are considered, namely mobile robot technology, planning and scheduling and communication. A methodology for implementation consisting of: a mobile robot system design (Little Helper prototype), an appropriate industrial application (multiple-part feeding), an implementation concept for the industrial application (the Bartender Concept), a mathematical model and a genetic algorithm-based heuristic is proposed. Furthermore, in order for the mobile robot to work properly in a flexible (cloud-based) manufacturing environment, the communications and exchange of data between the mobile robot with other manufacturing systems and shop-floor operators are addressed in the methodology. The proposed methodology provides insight into how mobile robot technology and abilities contribute to cloud manufacturing systems. A real-world demonstration at an impeller production line in a factory and computational experiments are conducted to demonstrate the effectiveness of the proposed methodology.