Conformational characteristics of polycaproamide in dimethylacetamide containing lithium chloride

The viscosity behavior, index of refraction, and density of dilute polycaproamide solutions in DMAc containing lithium chloride have been studied. On the basis of temperature dependences of the index of refraction and the density of solutions, the θ-condition of polycaproamide solutions in DMAc containing 2.5% lithium chloride is estimated as 21.3°C. From intrinsic viscosity [η] measurements, the coefficients of swelling of a polymer coil, the mean-square distance between chain ends, and other parameters of macromolecules in solution are calculated.     

Improving Construction for Connected Dominating Set with Steiner Tree in Wireless Sensor Networks

The connected dominating set plays an important role in ad hoc wireless networking. Many constructions for approximating the minimum connected dominating set have been proposed in the literature. In this paper, we propose a new one with Steiner tree, which produces approximation solution within a factor of 6.8 from optimal. This approximation algorithm can also be implemented distributedly.     

Recovered-voltage phenomenon and prospects for its use for assessment of the condition of polymers

A general theory of the phenomenon of recovered voltage in polymers was considered on the basis of representation of an actual poling process by a discrete set of Debye relaxators. Examples of numerical solution of the direct and inverse problems are given. A correlation expression between intentionally aged polymer specimens and recovered-voltage curves was proposed for use in the assessment of the material state of a polymer under actual service conditions. It was shown that it is sufficient to restrict consideration to three relaxation processes in analysis of the phenomenon.     

Magnetic,electrical transport and electron spin resonance studies of ferromagnetic insulating manganites Nd0.85Na0.15MnO3

We have investigated the magnetic, electrical transport and electron spin resonance (ESR) properties of polycrystalline Nd_0.85Na_0.15MnO₃ prepared by sol–gel method. A ferromagnetic–paramagnetic (FM–PM) transition is observed around 110 K, which is not accompanied by a metal–insulator transition. The sample displays the complete PM state associated with the ESR spectra fitted by single Lorentzian line shape above 130 K. Below 130 K, ESR spectra become distorted and then linewidth increases rapidly, where short-range magnetic order develops and coexists with PM phase due to the inhomogeneous magnetic state. In addition, the large difference between the activation energies obtained from the resistivity and ESR parameters (peak-to-peak linewidth and line intensity) at the frame of adiabatic small polaron hopping model is pointed out for Nd_0.85Na_0.15MnO₃.     

Corn stover fractions and bioenergy

Information is presented on structure, composition, and response to enzymes of corn stover related to barriers for bioconversion to ethanol. Aromatic compounds occurred in most tissue cell walls. Ferulic acid esterase treatment before cellulase treatment significantly improved dry weight loss and release of phenolic acids and sugars in most fractions over cellulase alone. Leaf fractions were considerably higher in dry weight loss and released sugars with esterase treatment, but stem pith cells gave up the most phenolic acids. Results help identify plant fractions more appropriate for coproducts and bioconversion and those more suitable as residues for soil erosion control.     

Visualization of industrial engineering data in Augmented Reality

This paper presents an innovative application of Augmented Reality (AR) techniques in the field of industrial engineering in which the user explores data from numerical simulations or the results of measurements and experiments, superimposed to the real object that they refer to. The user observes the object through a tablet PC, used as a video see-through handheld display. Data are visualized superimposed to the real object that represents a spatial reference relative to which the user can refer to, so the exploration is more natural compared to a traditional visualization software. Moreover, we have developed a new framework, called VTK4AR, that provides a set of useful software classes for the rapid development of AR applications for scientific visualization. VTK4AR is built on top of VTK (an open source API for scientific visualization), so it will be possible to employ a wide range of visualization techniques in many application fields, and moreover, it is possible to interactively manipulate data-sets in order to achieve a more effective way of visualization.     

Thermal treatment on composite γ-zirconium phosphate-silica

The prepared amorphous γ-ZrP\SiO₂ composite had a complicated composition, since a part of γ-ZrP is converted to α-form during the exfoliation of it. The γ-ZrP\SiO₂ composite have specific surface area of 421 m²g^–1. The acidic P–OH groups of the lamellae species placed on the surface (it is ≈1.0 meq g^–1), do not destroy until the temperature of 1030 K. During the thermal treatment the total mass loss of 7.79% was found. This value corresponds to 0.42 mole of H₂O per molecule unit. The water loss process was found very slow, because of the placing of bilamellar species in the composite.     

Synthesis and properties of carbon-chain polymers with pendant 1,3,4-oxadiazole rings

Carbon-chain polymers with 1,3,4-oxadiazole rings were prepared by radical polymerization and polymer-analogous transformations. The kinetic relationships of the polymerization of vinyl-1,3,4-oxadiazole monomers and some properties of the resulting polymers were studied. The thermodynamics of interaction of poly-2-vinyl-5-methyl-1,3,4-oxadiazole, a nonionic water-soluble polymer, with water was examined.     

Properties of the extraction system constituted by phosphoric acid produced from Khibiny apatite and tri-n-butyl phosphate

Data on the equilibrium distribution of phosphoric acid among the aqueous and organic phases in extraction of phosphoric acid with tri-n-butyl phosphate are presented for the system constituted by phosphoric acid produced from the Khibiny concentrate and by the extracting agent from the industrial system for purification of extraction phosphoric acid at 25–50°C.