Effective medium theory of the microwave and the infrared properties of composites with carbon nanotube inclusions

Carbon nanotubes (CNs) are electrically small particles at infrared and microwave frequencies. The Mossotti–Clausius formalism for estimating the effective permittivity dyadic of a dilute composite containing CN inclusions is described, and simplifications for certain orientational statistics are discussed. The polarizability dyadic of an electrically small CN is estimated from that of an infinitely long CN of the same cross-sectional diameter. A collection of randomly dispersed, aligned, nonchiral, electrically small CNs is shown to be transparent in the axial direction, but it can be either opaque or transparent in the transverse plane. Its effective electromagnetic response properties can be manipulated by a biasing magnetic field.     

New heterobimetallic Cu(I)–Pd(II)-containing polymer complexes: Electrochemical synthesis and application in catalysis

Electrochemical approach to a new electroactive heteropolynuclear catalytic system based on polyamic acids with biquinolyl (biQ) fragments in the polymer backbone capable of coordination to Pd^II and Cu^I-ions was developed using sacrificial Pd and Cu anodes. The order of anode dissolution (first Pd and then Cu) was shown to be important for the synthesis of the heteropolynuclear complex. The opposite order of dissolution resulted in the oxidation of the initially formed Cu^I ions to Cu^II. The redox properties of the obtained heteronuclear polymer complexes containing Cu^I and Pd^II coordination units were characterized by cyclic voltammetry. The catalytic properties of the resultant metal–polymer system were investigated and it showed high catalytic activity in the reaction of aryl halides with phenylacetylene (Sonogashira coupling) at a small Pd loadings (0.1 mol%) yielding 50–90% of arylphenylacetylene depending on the nature of the aryl halide. The proposed catalytic system also exhibits high catalytic activity in cascade cyclisations of 2-iodoaniline and 2-iodophenole in the presence of phenylacetylene yielding synthetically useful 2-phenylindole (90%) and 2-phenylbenzofuran (92%).     

Formation of polymer nanowires through electropolymerization of polybithiophene from mixed electrolyte solutions of tetrabutylammonium hexafluorophosphate and tetrabutylammonium chloride

Preparation of one-dimensional conducting polymer structures such as nanowires and nanotubes require anisotropic growth conditions. Usually, such conditions are achieved by applying a certain template or by patterning the substrate. In this work, we employ a new approach to facilitate the anisotropic growth of electrochemically deposited polybithiophene through variations of the conductivity of the growing material. If the deposited material varies in conductivity, the areas with less conducting material will sustain little or no electrochemical current and only the areas with sufficient conductivity will experience further growth. In this work, the conductivity variations and the resulting anisotropic growth are achieved by performing electropolymerization in mixed electrolyte solutions of tetrabutylammonium hexafluorophosphate and tetrabutylammonium chloride. No growth can be observed in pure tetrabutylammonium chloride because the resulting films are insulating. However, addition of small amounts of tetrabutylammonium hexafluorophosphate was found to selectively activate local nanometer-sized areas of the polymer surface where polymer nanowire growth was observed. The latter was confirmed by atomic-force microscopy (AFM). The local properties of the polymer nanostructures obtained with varying contents of tetrabutylammonium hexafluorophosphate were characterized.     

Evaluation of Substituted 1,2,3‐Dithiazoles as Inhibitors of the Feline Immunodeficiency Virus (FIV) Nucleocapsid Protein via a Proposed Zinc Ejection Mechanism

A diverse library of 5‐thieno‐, 5‐oxo‐, and 5‐imino‐1,2,3‐dithiazole derivatives was synthesized and evaluated for efficacy against the feline immunodeficiency virus (FIV) as a model for HIV in cells. Several diverse compounds from this series displayed nanomolar activity and low toxicity, representing a potential new class of compounds for the treatment of FIV and HIV.     

Parallel modeling of wildfires using efficient solvers for ill-conditioned linear systems

The Journal of Supercomputing - Numerical simulation of multi-physical processes requires a lot of processor time, especially when solving ill-conditional linear systems arising in fluid dynamics...     

The Wald Sequential Analysis Procedure as a Means of Guaranteeing a High Automatic Under-Frequency Load-Shedding Response Rate at Deviations of Unified Power Quality Indices

Power Technology and Engineering - The trend towards the decentralization of generating capacities in the power systems of many countries of the world has resulted in an increase in the proportion...     

Russian–EU collaboration via the mega-transect approach for large-scale projects: cases of RF Federal target Programme and SIWA JPI Climate EU Programme

The mega-transect approach is a unique infrastructure which was developed in Tomsk State University for environmental monitoring and landscape-ecological research. The approach can be followed in all seasons, for field sampling, ground-based research on the field stations in combination with remote sensing and ecosystem manipulations. The mega-transect was established as a framework for the concept of Western Siberia as a natural mega-facility, a kind of natural equivalent to CERN’s Large Hadron Collider, to attract leading international research groups. The paper describes cases of Russian Federation Federal target Programme and Siberian Inland Waters Joint Programming Initiative Climate EU Programme as examples of the large-scale international projects which are now resulting.     

Opening the black box: Managers’ perceptions of IS project success mechanisms

In general, works on information system (IS) project success focus on either project success factors or project success criteria, neglecting the relationships (mechanisms) between these concepts. Accordingly, it is mainly unclear how success factors actually contribute to success criteria. We attempt to illuminate this black box by conducting semi-structured qualitative interviews with experienced IS project managers by applying Repertory Grid and Laddering. Our exploratory study yields numerous success mechanisms, revealing project-related motivation to be the central hub in the factors-criteria network. Factors preceding project-related motivation such as transparency, certainty, and management attention are described.