Classifying informative and non-informative tweets from the twitter by adapting image features during disaster

Multimedia Tools and Applications - During the crisis, people post a large number of informative and non-informative tweets on Twitter. Informative tweets provide helpful information such as...     

Behaviour of photosensitive soft materials: Thermo-optical,dielectric and elastic constant studies on azo-dye doped nematic liquid crystals

Optical absorption, thermo-optical and dielectric studies have been performed on three guest–host nematic mixtures featuring photo-sensitized flexoelectric polarization. The liquid crystal 4-butyl-cyclohexane carboxylic acid 4-pentyloxy-phenyl ester, a room temperature nematic with a negative dielectric anisotropy served as the host material. Three different azo-dye compounds, also exhibiting liquid crystallinity were employed as the low-concentration guest component in the mixtures. In each case illumination of the sample with actinic (UV) light leads to strong photoisomerization driven effects. Correlations among the shift of the isotropic–nematic phase transition temperature, population of the cis isomers, and the change in the length of the azo-dyes upon UV illumination, are discussed. The UV-induced changes in the dielectric constant values have been shown to be dependent on the nature of the photoactive dopant. The article also describes the first observation of the lowering of the bend elastic constant upon photoisomerization, a feature ascribed to the formation of the bent-shaped cis isomers.     

Efficient traffic control and lifetime maximization in mobile ad hoc network by using PSO–BAT optimization

Recent developments in dynamic mobile ad-hoc network enhance the network speed and reliability. The nodes in the dynamic ad-hoc network are moving in nature. Due to the increased subscribers in this network, the network traffic has increased to manifold which in turn creating the challenge of maintaining the energy level. In path optimization process in mobile ad-hoc network consumes more energy and the draining of the energy is dependent on network reliability and connectivity. Further, the network also suffers by harmful attacks such as denial of service attack, black hole attack and warm hole attack. The primary focus of this paper is to prevent these attacks with the help of dynamic mobile ad-hoc network on demand protocol and hybrid meta-heuristics methodologies, and also to reduce the energy drain rate. This is achieved by estimating the velocity and fitness value of the nodes. Finally, the empirical simulation results of hybrid particle swarm optimization with bat algorithm (PSO–BAT) shows that the energy drain rate level is reduced 90% as 1 mJ/s than ad-hoc on demand vector. The end-to-end delay minimized to 50% than existing Ad hoc on-demand distance vector routing. The performance metrics routing overhead and execution time has been reduced and throughput is gradually increased in PSO–BAT optimization in dynamic mobile ad hoc network scenario.

     

An efficient approach for quantification of aortic regurgitation using proximal isovelocity surface area method

The proximal isovelocity surface area measurement, also called as the “flow convergence” method, can be used in echocardiography to estimate the area of an orifice through which blood flows. It has a lot of applications, but this paper focuses only on its use in the quantitative evaluation of aortic regurgitation. Proximal isovelocity surface area has been anticipated as a quantitative method to evaluate the severity of aortic regurgitation, In this paper, we present an effective approach based on an Image processing techniques which can accurately quantify the effective regurgitates orifice area (EROA) in aortic regurgitation by using the Doppler Echocardiography image with the aid of proximal isovelocity surface area. In the pre-processing stage, the color Doppler echocardiography image with RGB color space has been subjected to Wiener filtering. Subsequently it has been quantized with the aid of color quantization by using NBS/ISCC color space, which has made the quantification of aortic regurgitation color Doppler echocardiography image more accurate. Moreover that, the proximal isovelocity surface area (PISA) method is employed for calculation of quantitative parameters such as effective regurgitant orifice (ERO), Regurgitant volume, Regurgitant Fraction and more of aortic regurgitation (AR). The proximal flow convergence method has been exploited to quantify valvular regurgitation by the analysis of the converging flow field proximal to assess the mildness, severity and eccentricity of an aortic regurgitant lesion. Experimental evaluation on the commonly accessible dataset illustrates the enhanced performance of the proposed effective approach for the quantification of aortic regurgitation.     

Practical equivalent continuum characterization of jointed rock masses

A simple practical method to characterize the strength and stiffness of jointed rock masses is presented in this paper. The empirical relations for the strength and stiffness of rock masses have been arrived based on the statistical analysis of a large amount of experimental data, which are used for representing the jointed rock mass as an equivalent continuum. The effect of joints in the rock mass is taken into account by a joint factor. These obtained relations are incorporated in a non-linear FEM code to represent the equivalent continuum analysis. The equivalent continuum model has been validated against experimental results for jointed rock masses with different joint fabric and joint orientation and also with the results from explicit modeling of joints using FEM. The developed model has also been applied to calculate the deformation around a large power station cavern in rhyolite rock at 200 m depth.     

Preparation and characterization of flash-evaporated CuInSe2 thin films

Thin films of CuInSe₂ have been evaporated onto glass substrates by flash evaporation. The as-deposited films are amorphous and annealing in selenium atmosphere produces polycrystalline films. The films were characterized bytem and x-ray diffraction techniques. The optical absorption of the films shows three energy gaps of 1·03, 1·07 and 1·22 eV. The crystal field and spin-orbit splitting are thus found to be 0·04 eV and 0·16 eV respectively. The percentaged-character of the valence band states is ∼35%. The Arrhenius plot of electrical conductivity of films showed impurity ionization ofE _A = 75 meV.     

Maximizing the production of hydrogen and carbon nanotubes: Effect of Ni and reaction temperature

With the objective of maximizing hydrogen and CNTs production, the catalytic cracking of naphtha has been carried out at progressive reaction temperatures i.e. from 600 to 750 °C. The ZSM-5 and nickel impregnated ZSM-5 were used as catalysts for cracking purpose in fluidization mode. The catalyst analysis imparted that impregnation of metallic nickel induces a strong adhesion on MFI structure of ZSM-5 associated with an enhancement in textural properties and acid density. In addition, the results disclose that the incorporation of nickel on ZSM-5 leads to increment in stability of catalyst which in turn pushes the yields of H₂, CNTs and conversion to greater values of 3.29%, 4.84% and 90%, respectively. The as-grown carbon structures over the catalyst surface were found to be multiwall carbon nanotubes confirmed by Raman spectra and TGA analysis where they exhibited high quality (I_D/I_G = 0.65) and purity, respectively, at 750 °C.     

Vapor-liquid-Solid synthesis of [010]-oriented Sb2Se3 nanowires

In this article we report for the first time the synthesis of Sb2Se3 nanowires using a physical vapor-liquid-solid (VLS) process. We used microcrystals of Antimony as solid catalytic material and molten Selenium to generate the vapor source. Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) images show that as-obtained Sb2Se3 nanowires have diameters in the range between 20 nm and 2 microm and lengths up to 30 microm. Fringes in TEM imaging reveals that Sb2Se3 nanowires are oriented along the [010] crystallographic direction. This orientation is being reported for the first time.     

Investigation of Quantum Confinement Effects on Molybdenum Disulfide (MoS2) Based Transistor Using Ritz Galerkin Finite Element Technique

Silicon - This paper presents the effect of quantum confinement on the potential of short channel mono-layer molybdenum disulfide (MoS2) based transistor using Ritz Galerkin finite element...