Many body effects on the transport properties of a doped nano device

In this article, we study the effect of electron-electron interaction in a doped nano cluster sandwich between two electrodes. The Hamiltonian of the cluster is written in the tight-binding model and electrodes are described in the wide-band approximation. The GW approximation has been used for the calculation of the exchange-correlation term in the cluster region. Our results showed that in the presence of the electronelectron interaction the transmittance gap increases and current decreases. Also, in a doped nano structure the transmission decreases and many body effect becomes more important. By considering the exchange-correlation in a doped nano cluster in the GW approximation the transmission and current decrease drastically. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2056

The seroprevalence of Mycoplasma pneumoniae IgM and IgG antibodies in patients with ischemic stroke

Background and Objectives: Association between Mycoplasma pneumoniae infection and increased risk for brain stroke has been well understood. Hence, the value of serologic tests for assessing causative relationship between this infection and brain stroke seems to be high. The present study aimed to determine serum level of anti-Mycoplasma pneumoniae antibodies in patients with brain stroke and to compare it with non-stroke patients. Materials and Methods: This cross-sectional study was performed on 97 consecutive ischemic stroke patients and 97 sex and age-matched non-stroke patients. Quantitative enzyme-linked immunosorbent assay (ELISA) was established to measure the levels of anti-Mycoplasma pneumoniae IgG and IgM antibodies. Results: Regarding the level of anti-Mycoplasma pneumoniae IgM, the titer of this marker was positive in 4.1 of patients with ischemic stroke, while none of the subjects in control group had positive titer for this antibody (OR = 1.043, 95CI: 1.001 � 1.087, p = 0.043). The rate of positivity for anti-Mycoplasma pneumoniae IgG in ischemic stroke patients was significantly higher than in the control group (28.5 versus 13.4, p = 0.031). Odds ratio for exposure to M. pneumoniae was 2.24 times of the control subjects. The level of anti-Mycoplasma pneumoniae IgM was independent to both sex and age variables in patients group (p = 0.77). The level of anti-Mycoplasma pneumoniae IgG did not depend on subjects� gender in control group, but was significantly higher in men compared with women in patients group. Conclusion: A high level of anti-Mycoplasma pneumoniae IgM and IgG antibodies indicate a significant association of M. pneumoniae infection and history of this infection with increased risk for ischemic stroke. © 2016, Tehran University of Medical Science. All rights reserved

A cantilever approach to estimate bending stiffness of buildings affected by tunnelling

The evaluation of the effect of tunnel construction on buildings is a problem being faced by engineers around the world. Building bending stiffness is an important parameter in tunnel-soil-structure interaction analyses. The construction of a new tunnel influences an existing building via induced ground movements, and the existence of a building also affects ground displacements due to tunnelling via its stiffness and weight. The magnitude of the effect depends on the properties of the building and foundation as well as the complex soil-structure interactions that occur. In this paper, an approach is proposed in which the building response to tunnelling is related to the bending of a cantilever beam and empirical-type relationships are developed to predict building bending stiffness. This approach is relevant to cases where the building is perpendicular to the tunnel axis and its nearest edge does not overlap more than half of the tunnel cross-section. Rigorous finite element analyses are used to evaluate the response of buildings to ground displacements and expressions are provided which relate three-dimensional building bending stiffness to a simple beam theory expression. The results show that lower storeys have a proportionally higher stiffness effect than higher storeys. In addition, the parameters that affect the global behaviour of the building, such as component stiffness and geometry, are studied. The suggested approach provides a relatively quick and easy way of accurately evaluating building bending stiffness for use within tunnel-soil structure interaction analyses

Microstructural evolution of copper-titanium alloy during in-situ formation of TiB2 particles

Bulk Cu-Ti alloy reinforced by TiB2 nano particles was prepared using in-situ reaction between Cu-3.4%Ti and Cu-0.7%B master alloys along with rapid solidification and subsequent heat treatment for 1-10 h at 900 C. High-resolution transmission electron microscopy (HRTEM) characterization showed that primary TiB2 nano particles and TiB whiskers were formed by in-situ reaction between Ti and B in the liquid copper. The formation of TiB whiskers within the melt led to coarsening of TiB2 particles. Primary TiB2 particles were dispersed along the grain boundaries and hindered grain growth at high temperature, while the secondary TiB2 particles were formed during heat treatment of the alloy by diffusion reaction of solute titanium and boron inside the grains. Electrical conductivity and hardness of the composite were evaluated during heat treatment. The results indicated that the formation of secondary TiB2 particles in the matrix caused a delay in hardness reduction at high temperature. The electrical conductivity and hardness increased up to 8 h of heat treatment and reached 33.5% IACS and HV 158, respectively.

Synthesis of Suitable SiO2 Nano Particles as the Core in Core–Shell Nanostructured Materials

The effect of surfactant on the luminescent intensity of SiO2@Y2O3:Eu3+ particles with a core shellstructure is described. Core–shell particles are used in phosphor materials and employing sphericalparticles with a narrow size distribution is vital for the enhancement of luminescent properties. Threekinds of different surfactants were used to synthesis SiO2 nano particles via a sol gel process. Theresults demonstrated that comb polycarboxylic acid surfactant had a significant influence on themorphology and particle size distribution. Somehow, particles with 100 nm size and narrow sizedistribution were produced. These particles had relatively uniform packing, unlike particles producedwith other surfactants or without surfactant which had irregular assembly. The photoluminescenceintensity of SiO2@Y2O3:Eu3+ particles that was synthesized by comb polycarboxylic acid surfactantwas higher than those which were produced without surfactan

Synthesis of Suitable SiO2 Nano Particles as the Core in Core–Shell Nanostructured Materials

The effect of surfactant on the luminescent intensity of SiO2@Y2O3:Eu3+ particles with a core shell structure is described. Core–shell particles are used in phosphor materials and employing spherical particles with a narrow size distribution is vital for the enhancement of luminescent properties. Three kinds of different surfactants were used to synthesis SiO2 nano particles via a sol gel process. The results demonstrated that comb polycarboxylic acid surfactant had a significant influence on the morphology and particle size distribution. Somehow, particles with 100 nm size and narrow size distribution were produced. These particles had relatively uniform packing, unlike particles produced with other surfactants or without surfactant which had irregular assembly. The photoluminescence intensity of SiO2@Y2O3:Eu3+ particles that was synthesized by comb polycarboxylic acid surfactant was higher than those which were produced without surfactan