A concise review on microbial remediation cells (MRCs) in soil and groundwater radionuclides remediation

Currently, the existing microbial radionuclides transformations processes are not completely understood. Bacteria, however, solubilize radionuclides by direct enzymatic reduction, or indirectly by its metabolites and by facilitating electrochemical redox systems. Microbes exchange electrons from proteins, organelles, metabolites to metals and electrodes have strengthened the novel bioremediation methods. In contrast, MRCs based on this redox behavior has offered considerable value over traditional treatment because of growing renewable and conception of energy incentives methods. Moreover, MRCs provides a flexible platform that enables us to access integrated treatment process of generating power and for recovering valuable resources from the contaminated sites.     

Role of reactive species in processing materials at laboratory temperature by spray plasma devices

Processing the aerosol of metal salts in non-equilibrium plasma represents a promising technique that combines the advantages of spray pyrolysis with the high reactivity of plasmas at nearlaboratory temperature in order to produce mixed-oxides and perovskite materials. The aim of this paper is to describe the principles of this new technique and to present the various applications and latest developments. This technique’s capacity to deposit various mixed metal oxides with precise stoichiometry is demonstrated. It is shown that oxidant plasma species play a key role in the chemical transformation of starting materials into oxides at laboratory temperature, while the configuration of the reactor determines the morphology and texture of the deposited layers. Two different reactor configurations are presented. The porous layers of La _x Sr_1−x MnO₃ as the cathode for fuel cells were synthesised in a wave shock reactor configuration, while nanostructured ZnO-Al layers to form a transparent conductive cathode for photovoltaic cells were deposited in the spray plasma reactor of the latest generation for this technique. The experimental results emphasise the role of plasma species in the rate of chemical reactions and in the chemical composition of the deposited layers.     

Polymeric catalyst for the synthesis of new pyrido[2,3-b]indoles

A new and efficient method has been developed for the one-pot synthesis of novel 2,9-dihydro-2-oxo-4-aryl-1H-pyrido[2,3-b]indole-3-carbonitrile derivatives by condensation of substituted (triethoxymethyl)arene, 1-methyl-1H-indol-2-ol and cyanoacetamide in the presence of a catalytic amount of crosslinked poly(2-acrylamido-2-methyl propane sulfonic acid) (AMPS) as an efficient and heterogeneous catalyst. This polymeric solid acid catalyst is stable and can be easily recovered and reused without significant change in its activity.     

Electrosynthesis,characterization and photoconducting performance of copolymer poly(terthiophene + sexithiophene + TiO<Subscript>2</Subscript>)/ITO composite material

In the present work, a new composite material poly(3T + 6T + TiO₂) was electrochemically synthesized. This composite material was synthesized in a solution of (CH2Cl2/TBAP) containing the monomers (terthiophene), (sexithiophene) and semiconductor (TiO₂) particles. The preparedsamples were characterized electrochemically by cyclic voltamperometry (CV) and spectrometry analysis by scanning electron microscopy (SEM), ultraviolet-visible (UV-Vis) absorption spectroscopy, energy dispersive X-ray spectroscopy (EDX) and fourier transform infrared spectroscopy (FTIR), respectively. The effect of TiO₂ concentration in the solution on dispersed microparticle entity and on the photocurrent response was investigated. The results showed that TiO₂ particles were dispersed and codeposited into the copolymer poly(3T + 6T + TiO₂) matrix, and titanium atom was confirmed by EDX spectra. From SEM images, the TiO₂ has a spherical shape and micrometer size. The FTIR spectrum indicated that titanium dioxide do not show a significant modification in terms of band shape and no interaction between polymers and TiO₂ particles. Furthermore, the results showed that the composite films with different amounts of TiO₂ exhibit good photocurrent properties which imply that these composites films can be used in various fields, such as photoelectrochemical applications as photovoltaic cells.     

General pairing mechanisms in the BCS-theory of superconductivity

Starting from the linearized BdG-equation we make the simple observation that pairing can occur between particles with total momenta different from zero, e.g., with equal momentum and opposite spin, in cases of an effective interaction acting in the center-of-mass coordinates.     

Study on alpha cup technique for monitoring of soil radon levels

Determination of radon concentrations in soil usually requires the accumulation of many measurements over a large area. In this study, an alpha cup technique that provides a cumulative result for adsorption of radon progeny over time was investigated. In addition, the performance of measurements were evaluated. To avoid the impacts of temperature and humidity, a new arithmetic correction was explored. Finally, we also investigated the effect of burial time of the alpha cup on soil radon measurements. Experiments showed that the alpha cup technique can satisfy the demands of soil radon measurements in efficiency, accuracy, reliability, and stability.     

Integral representations for the Lagrange polynomials,Shively’s pseudo-Laguerre polynomials,and the generalized Bessel polynomials

Motivated essentially by their potential for applications in the mathematical, physical, and statistical sciences, the object of this paper is to investigate several general families of hypergeometric polynomials and their associated multiple integral representations. By suitably specializing the main results presented here, the corresponding integral representations are derived for familiar simpler classes of hypergeometric polynomials such as (for example) the Lagrange polynomials, Shively’s pseudo-Laguerre polynomials, and generalized Bessel polynomials. Each of the integral representations derived in this paper may be also viewed as a linearization relationship for the product of two different members of the associated family of hypergeometric polynomials.     

Modelling intra- and intermolecular vibrations under the harmonic oscillator approximation: from symmetry-adapted to coarse-grained coordinate approaches

Motions of some four-body spring–mass systems are analyzed as models of normal-mode vibrations of bimolecular systems interacting via intermolecular forces. The formulation is first introduced with Cartesian coordinates, and the basis is subsequently transformed to symmetry-adapted coordinates; this transformation easily leads to coarse graining of atomic displacement vectors. We derived an analytical form for the eigenfrequencies of homodimeric coupled oscillators, and an approximated form for heterodimeric coupled oscillator. Compared to the primitive pseudodiatomic approximation, this approach provides a more realistic view of intermolecular stretching motions.