Alternating electrical conductivity of polyphenylenes and their pyrolysis residues after doping

o,m,p-Polyphenylenes were prepared by oxidation-cationic polymerization of biphenyl and then pyrolyzed up to 800°C. The o,m,p-polyphenylenes as well as their pyrolysis residues were doped with anhydrous FeCl₃ from their solution in acetonitrile. The real part of the alternating electrical conductivity σ′ of the undoped and doped materials was determined at room temperature. Decreasing σ′-values of pyrolyzed residues at 600°C without doping were observed because of the large weight losses during the pyrolysis leading to chain scission reactions within the polymer. At higher pyrolysis temperatures (i.e. 700°C, 800°C) the σ′-values are increased due to the formation of closed aromatic systems in the polymer. The doped materials have higher σ′-values in relation to the corresponding specimens without doping, with the exception of the pyrolysis residues at 800°C. The dependence of doping effect and time was also determined. The transition of the organic polymer to the pyropolymers can be followed and characterized by the measurement of alternating electrical conductivity.     

Study of Algorithmic and Architectural Characteristics of Gaussian Particle Filters

In this paper, we analyze algorithmic and architectural characteristics of a class of particle filters known as Gaussian Particle Filters (GPFs). GPFs approximate the posterior density of the unknowns with a Gaussian distribution which limits the scope of their applications in comparison with the universally applied sample-importance resampling filters (SIRFs) but allows for their implementation without the classical resampling procedure. Since there is no need for resampling, we propose a modified GPF algorithm that is suitable for parallel hardware realization. Based on the new algorithm, we propose an efficient parallel and pipelined architecture for GPF that is superior to similar architectures for SIRF in the sense that it requires no memories for storing particles and it has very low amount of data exchange through the communication network. We analyze the GPF on the bearings-only tracking problem and the results are compared with results obtained by SIRF in terms of computational complexity, potential throughput, and hardware energy. We consider implementation on FPGAs and we perform detailed comparison of the GPF and SIRF algorithms implemented in different ways on this platform. GPFs that are implemented in parallel pipelined fashion on FPGAs can support higher sampling rates than SIRFs and as such they might be a more suitable candidate for real-time applications.     

P3HT : PCBM solar cells—The choice of source material

Bulk heterojunction solar cells based on P3HT : PCBM blend films are among the most intensively studied polymer solar cells. In spite of that, there is a huge variation of reported efficiencies in the literature, even for same device architectures and film preparation procedures. Here we investigated the influence of starting properties of P3HT and PCBM (different suppliers) on blend film morphology and device performance. We found that there was a strong dependence of the film morphology and device performance on the source of chemicals used. Both P3HT and PCBM affected the results, and higher nominal purity did not necessarily result in better device performance. The dependence of the film morphology and device performance on the properties of P3HT and PCBM is discussed in detail. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39776.     

Rare case of congenital chyluria

A rare case is presented of congenital chyluria in a 16-year-old boy. On the basis of literature data the pathological mechanism of that disease is discussed. The clinical data and examinations carried out, particularly lymphography, confirmed the preliminary clinical diagnosis.     

Statistical Modeling of the Industrial Sodium Aluminate Solutions Decomposition Process

This article presents the results of the statistical modeling of industrial sodium aluminate solution decomposition as part of the Bayer alumina production process. The aim of this study was to define the correlation dependence of degree of the aluminate solution decomposition on the following parameters of technological processes: concentration of the Na₂O (caustic), caustic ratio and crystallization ratio, starting temperature, final temperature, average diameter of crystallization seed, and duration of decomposition process. Multiple linear regression analysis (MLRA) and artificial neural networks (ANNs) were used as the tools for the mathematical analysis of the indicated problem. On the one hand, the attempt of process modeling, using MLRA, resulted in a linear model whose correlation coefficient was equal to R ² = 0.731. On the other hand, ANNs enabled, to some extent, better process modeling, with a correlation coefficient equal to R ² = 0.895. Both models obtained using MLRA and ANNs can be used for the efficient prediction of the degree of sodium aluminate solution decomposition, as the function of the input parameters, under industrial conditions of the Bayer alumina production process.     

Some peculiarities of (Hg,Cd) Te liquid-phase epitaxial growth in a semi-closed,two-zone system

A semi-closed, two-zone system for (Hg, Cd) Te liquid-phase epitaxy (LPE) is described which has the main advantage of closed systems: namely, there is no loss of mercury from the solution. The system retains all the good properties of open systems, i.e. it simplifies the repeated use. One other advantage is the possibility of rinsing the system in pure hydrogen. In order to establish the experimental conditions for obtaining the LPE (Hg, Cd) Te layers of desired composition on the CdTe or CdZnTe substrates, it is first necessary to study the problems of maintenance of the already homogenized solution composition, homogenization rate, and the epitaxial layers' composition changes as a function of solution supercooling.     

A review on solid oxide derived from waste shells as catalyst for biodiesel production

The waste eggs and mollusk shells are found to be the richest sources of calcium carbonate and have been utilized for various purposes after proper treatments. When calcined at a proper temperature calcium carbonate converts into CaO, which is a metal oxide. Researchers have found that the CaO prepared from the waste shells can be used as catalyst in biodiesel production process. Utilization of waste shells as a source of CaO not only gives an opportunity to use it as catalyst but also adds value to the waste generated. In this paper a brief discussion with recent development on biodiesel production using waste shell derived solid oxide as catalyst is presented.