EFFECT OF CARBON NANOTUBES ON THE ELECTRICAL PROPERTIES OF THE POLYMERIC COMPOSITES

Experimental study of single-wall carbon nabotubes (CNT) effect on the electrical properties of polymeric composite materials based on epoxy matrix has been carried out. Direct-current (DC) as well as alternating-current (AC) electrical conductivity of nanocomposites with different CNT concentrations have been investigated in the temperature interval from 293 K to 373 K. Measurements of Seebeck coefficient confirm n-type conductivity of composite with CNTs. Percolation threshold of the composite material under study has been estimated. It has been found that addition of single-wall CNT at low concentration causes hysteresis of current-voltage characteristics and the temperature dependences of electrical conductivity as well as its anisotropy in the samples under study. No noticeable frequency dependence of the AC electrical conductivity has been found in the frequency range from 100 Hz to 300 kHz

Microscopic Analysis of Severe Structural Rearrangements of the Plant Endoplasmic Reticulum and Golgi Caused by Overexpression of Poa semilatent virus Movement Protein

Cell-to-cell transport of plant viruses is mediated by virus-encoded movement proteins and occurs through plasmodesmata interconnecting neighboring cells in plant tissues. Three movement proteins coded by the “triple gene block” (TGB) and named TGBp1, TGBp2 and TGBp3 have distinct functions in viral transport. TGBp1 binds viral genomic RNAs to form ribonucleoprotein complexes representing the transport form of viral genome, while TGBp2 and TGBp3 are necessary for intracellular delivery of such complexes to plasmodesmata. Recently, it was revealed that overexpression of Potato virus X TGBp3 triggers the unfolded protein response mitigating the endoplasmic reticulum (ER) stress leading to cell death if this protein reaches high levels in the ER. Here we report microscopic studies of the influence of the Poa semilatent hordeivirus TGBp3 overexpressed in Nicotiana benthamiana epidermal cells by particle bombardment on cell endomembranes and demonstrate that the protein C-terminal transmembrane segment contains a determinant responsible for vesiculation and coalescence of the endoplasmic reticulum and Golgi presumably accompanying the ER stress that can be induced upon high-level TGBp3 expression

An efficient truncated SVD of large matrices based on the low-rank approximation for inverse geophysical problems

International audienceIn this paper, we propose a new algorithm to compute a truncated singular value decomposition (T-SVD) of the Born matrix based on a low-rank arithmetic. This algorithm is tested in the context of acoustic media. Theoretical background to the low-rank SVD method is presented: the Born matrix of an acoustic problem can be approximated by a low-rank approximation derived thanks to a kernel independent multipole expansion. The new algorithm to compute T-SVD approximation consists of four steps, and they are described in detail. The largest singular values and their left and right singular vectors can be approximated numerically without performing any operation with the full matrix. The low-rank approximation is computed due to a dynamic panel strategy of cross approximation (CA) technique. At the end of the paper, we present a numerical experiment to illustrate the efficiency and precision of the algorithm proposed

RELIABILITY ANALYSIS OF REINFORCED CONCRETEELEMENTSWITH NORMAL CRACKS (ON RC BEAM EXAMPLE)

The purpose of research is development of methods for reliability analysis of structural reinforced concrete elements (on example of reinforced concrete beam) according to criterion of the normal cracks length in tensile zone of concrete. Cracks in tensile zone of concrete in beams leads to displacement of the beam's neutralaxis towards the compressed part of the concrete, thereby increasing the compressionstress in the concrete, to the increasing of the stress in the reinforcement bars on the crack width, to the growth of corrosion processes, etc. This leads to the decreasing of beams mechanical safety and reliability (as a quantitative measure of mechanical safety). The main parameters, which reduce the strength and stiffness of the beam, of the cracksis the length and width of the crack. The article describesthe influence of the cracks length on the reliability of reinforced concrete elements. The article differs from existing approaches in that isitbuilt on a limited statistical dataofcontrolled parameters in mathematical models of limit state. The article alsoconsidersthe influence of cracks in the structuralelement. The methods of reliability analysis allow to assess the mechanical safety of reinforced concrete elements and to make appropriate decisions about the safety, strengthening or replacement of thereinforced concreteelement

THE CONSTITUTION OF THE RUSSIAN FEDERATION IN THE ASPECT OF REQUIREMENTS FOR RUSSIAN AS A STATE LANGUAGE

On the results of the linguistic analysis of the text of the Constitution of the Russian Federation and the requirements that are imposed by legal discourse to the language of legal documents the authors reveal a set of obligatory characteristics of the language of the legal document, including definiteness, accuracy, clearness, stylistic neutrality, and language correctness. Application of these characteristics to assessing the quality of the text of Russian Constitution lead to finding some contextual gaps which might cause difficulties in understanding of some provisions in the basic law of the country. Violations of the accuracy and clarity of statements include those provisions of the Constitution in which lexical units are implemented in different meanings. In such cases, the distortion of meaning is possible at the stage of understanding (interpretation) of the verbal form. The articles of the Constitution also reveal a violation of clarity, which is accompanied by legal and linguistic uncertainty. The article provides examples of formulations that do not comply with the rules and norms of the use of language means in legal acts, as well as proposed ways to overcome these inconsistencies. It is argued that the development and application of a special linguistic methodology focused on communicative and rhetorical analysis of legally significant texts will allow more effective linguistic interpretation of normative legal acts, including the Constitution of the Russian Federation, as well as ensure uniformity of their application

EFFECT OF HEAT TREATMENT ON ELECTRICAL AND MECHANICAL PROPERTIES OF THE SOLID SAPROPEL

In this work changes of electrical and mechanical properties (hardness) of the solid sapropel after its heat treatment were researched. Changes of real and imaginary parts of dielectric permittivity, dielectric losses and specific electrical resistance depending on electrical field frequency in the range 0.01Hz- 1MHz were observed. Temperature dependences of AC (at 1 kHz) and DC electrical conductivity were studied. Chemical sample composition, IR spectra and structure of the solid sapropel were investigated. Heat treatment has a noticeable effect on the electrical characteristics of solid sapropel due to the strong influence of water on the charge transfer in this complex material. Charge transfer occurs predominantly due to ion migration and demonstrates strong dependence upon hydration - dehydration processes. After the heat treatment of the solid sapropel at the temperature of 1000C its hardness doesn’t change. If the sample of the solid sapropel is subjected to 20 min heat treatment at the temperature of 1500C, its hardness decreases by 5.4%, the number of C=C bonds decreases by 6.3±0.1%, the number of C=N bonds decreases by 2.2±0.1%, the number of C-C bonds decreases by 1,7±0.1%, the number of C-H bonds increases by 18.5±0.3%. It shows that in the temperature range 100-1500C destructive processes of the solid sapropel start, although visually (with optical microscope and with SEM) changes of structure are impossible to observe yet

Plant 4/1 protein: potential player in intracellular, cell-to-cell and long-distance signaling

Originally isolated as a result of its ability to interact with the movement protein of Tomato spotted wilt virus in a yeast two-hybrid system, the 4/1 protein is proving to be an excellent tool for studying intracellular protein trafficking and intercellular communication. Expression of 4/1 in vivo is tightly regulated, first appearing in the veins of the cotyledon and later in the vasculature of the leaf and stem in association with the xylem parenchyma and phloem parenchyma. Structural studies indicate that 4/1 proteins contain as many as five coiled–coil (CC) domains; indeed, the highest level of sequence identity among 4/1 proteins involves their C-terminal CC domains, suggesting that protein–protein interaction is important for biological function. Recent data predict that the tertiary structure of this C-terminal CC domain is strikingly similar to that of yeast protein She2p; furthermore, like She2p, 4/1 protein exhibits RNA-binding activity, and mutational analysis has shown that the C-terminal CC domain is responsible for RNA binding. The 4/1 protein contains a nuclear export signal. Additional microscopy studies involving leptomycin and computer prediction suggest the presence of a nuclear localization signal as well