Thermal analysis of randomly oriented carbon nanotube reinforced functionally graded timoshenko beam

The unique thermal properties of carbon nanotubes (CNT) are utilized to increase the use of functionally graded material (FGM) at higher temperatures which resulted in introduction of a new type of material called as functionally graded carbon nanotube-reinforced composites (FG-CNTRCs). To use the FG-CNTRCs at elevated temperatures, their thermal analysis is very important. In this context, this article presents the thermal analysis of a CNT based FG Timoshenko beam. Material properties distribution is assumed to vary along the thickness direction according to power law distribution and linear distributions. Finite difference method is implemented to find out the temperature distribution. Using first order shear deformation theory (FSDT), expressions for strains and stresses are obtained. The results are compared with temperature distribution according to power law. The effect of CNT distribution on strains and stresses is also observed. Based on these results important conclusions have been drawn.     

Proposal and investigation of photonic data selector based on cross-phase modulation in a highly nonlinear fiber

It is proposed and demonstrated a design of 2-to-1 photonic data selector based on the cross-phase modulation in a highly nonlinear fiber. By using bidirectional configuration, this scheme has potentially advantages of cost effective and simple structure. The correct output logic function is obtained at 40 Gbit/s without using any additional input light beams. In addition, the output signals have a single spectrum component by reasonable selecting input signals wavelength, which is important for transmission and scalability. The dependences of performances on signal wavelength, pump power, the temporal relative position of pulses, as well as the OSNR and chirp of input signals are calculated and discussed respectively, showing impressive operation performance. This scheme could be a promising candidate for future ultrafast all-optical signal processing applications.     

Combined effect of Ni and nano-Y2O3 addition on microstructure,mechanical and high temperature behavior of mechanically alloyed W-Mo

Nanostructured tungsten (W) based alloys with the nominal compositions of W₇₀Mo₃₀ (alloy A), W₅₀Mo₅₀ (alloy B), and 1.0 wt.% nano-Y₂O₃ dispersed W₇₉Ni₁₀Mo₁₀ (alloy C) (all in wt.%) have been synthesized by mechanical alloying followed by compaction at 0.50, 0.75 and 1 GPa pressure for 5 mins and conventional sintering at 1500 °C for 2 h in Ar atmosphere. The microstructure, evolution of phases and thermal behavior of milled powders and consolidated products has been investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), High resolution transmission electron microscopy (TEM), Energy dispersive spectroscopy (EDS) and differential scanning calorimetry (DSC). Minimum crystallite size of 29.4 nm and maximum lattice strain and dislocation density of 0.51% and 18.93 (10¹⁶/m²) respectively has been achieved in alloy C at 20 h of milling. Addition of nano-Y₂O₃ reduces the activation energy for recrystallization of W based alloys. Alloy C compacted at 1 GPa pressure shows enhanced sintered density, hardness, compressive strength and elongation of 95.2%, 9.12 GPa, 1.51 GPa, 19.5% respectively as well as superior wear resistance and oxidation resistance (at 1000 °C) as compared to other W-Mo alloys.     

A Graphical-based educational simulation tool for Wireless Sensor Networks

Many routing protocols have been developed to improve the lifetime, bandwidth reusability and scalability of the Wireless Sensor Networks (WSNs). The operation of routing protocols is difficult to understand and some problems may occur while developing these protocols. Simulation is a relatively fast way of estimating these protocols and understating what is happening in the network. Thus, this paper presents an open source Graphical-based educational simulation tool called Gbest-WSN for simulating routing protocols of the static and mobile, homogeneous and heterogeneous WSNs. Gbest-WSN tool has a user-friendly interface that helps the user to select the routing protocol and define the network configuration. It is provided with four routing protocols; namely LEACH, LEACH-Mobile, immune algorithm-based and genetic algorithm-based routing protocols. Also, it allows the user to update the existing routing protocols and add a new routing protocol. Gbest-WSN is provided with radio, coverage and mobility models for modeling the hardware of the sensor node. It shows a detailed 2D and 3D graphical perception for what is happing during the routing process. Also, it has the ability to compare the simulation results of different simulation methods or different network configurations. In addition, it allows the user to save and load simulation scenarios and also exports the graphical results on PDF files and the statistical results on excel or mat files. Moreover, Gbest-WSN is provided with html help documents to help the user how to use it. The illustrative simulation examples clarified that the Gbest-WSN is a helpful tool for the students, teachers and researchers who work in the field of WSNs.     

Face expression recognition system based on ripplet transform type II and least square SVM

Multimedia Tools and Applications - This paper discusses the development of an efficient and automated system for the recognition of facial expressions, which is essentially an application...     

Toughening of Polylactic Acid: An Overview of Research Progress

To overcome the limitations of polylactic acid, alterations are needed to enhance its toughness, to improve handling and for various applications. Extensive studies were reported, mainly in the area of blends with renewable resource polymer blends. Better phase dispersion between the blend materials is achieved either by reactive mixing of the two components or by incorporation of a block copolymer compatibilizer, finally showing highly enhanced property. In this article, the recent research progress of different toughening processes of PLA via blending is reviewed and a detailed understanding about toughening of PLA using biodegradable or renewable polymers has been established.     

Effect of low energy proton beam irradiation on structural and electrical properties of ZnO:Al thin films

In this study, we report the structural modification and change in electrical behaviour of aluminium doped zinc oxide by low energy (100 keV) proton irradiation. Aluminium doped zinc oxide films were deposited using DC magnetron sputtering and then annealed for a short duration at 600 °C before irradiation. Structural and defect studies of the films carried out using XRD and Raman spectroscopy. It suggests that the crystalline ordering increases at higher fluences due to annealing of defects in the film. The increase in crystallinity at higher fluences decreases the grain boundary scattering and causes low resistivity. There is no significant change in carrier concentration after the irradiation, however the mobility and resistivity of the Al doped ZnO films change with proton irradiated fluences. The development of defect due to irradiation has been confirmed through Raman spectroscopic studies. The increase in activation energy of particles has been suggested by low energy proton irradiations at higher fluences in the annealed Al doped ZnO thin films. The uniform particle distribution increases with fluences of the irradiation that may be helpful for spintronics and sensor device technology.     

Characterization of host response to bruchids (Callosobruchus chinensis and C. maculatus) in 39 genotypes belongs to 12 Cajanus spp. And assessment of molecular diversity inter se

Thirty nine genotypes belong to 12 Cajanus species were characterized for host response to bruchids (C. chinensis and C. maculatus) using no-choice based in vivo and in vitro antibiosis assay, and these assays revealed seven genotypes of primary gene pool (C. cajan) were more susceptible to bruchid infestation as compared to the genotypes of secondary and tertiary gene pools. Among all the genotypes, C. cajanifolius acc. ICPW-31 showed higher degree of resistance to both the bruchids. The molecular diversity using CDDP and SCoT markers showed wide range of genetic variations among the 12 species of Cajanus, and was supported by estimates of Nei's genetic distance and fixation index (F_ST) based haplotype matrix. The genetic structure showed clustering of 39 genotypes into eight distinct groups (K = 8) on the basis of their allelic composition, and among them C. cajanifolius acc. ICPW 31 and ICPW 30 showed close affinity with the cultivars of C. cajan by sharing several alleles. AMOVA analyses showed the existence of higher extent of genetic variation both at the genotype (37%) and species (63%) level in the genus Cajanus. The dendrogram and the principal coordinate analysis (PCoA) placed the 39 genotypes into six major clusters at par with their sectional classification. MCheza and ARLEQUIN based outlier analysis revealed 13 common loci under balancing selection, which are supposed to be involved in maintenance of genetic polymorphism either at species or genotype level, and are assigned to putative gene families such as KNOX, WRKY, ERF, MYB, ABP1 and MADS. The in vivo and in vitro bruchid assay vis-à-vis the DNA marker based molecular diversity analysis affirmed the possible use of C. cajanifolius acc. ICPW-31 as donor genotype for the introgression of bruchid resistance allele(s) into cultivated genetic background.     

Fatigue performance of friction stir welded Al2024 alloy in a different corrosive environment

The study examines the corrosion fatigue behavior of friction stir welded Al2024 alloy in the corrosive medium. The fatigue tests are conducted at a stress ratio of -1 in the different corrosive medium. The decrease in the fatigue life of welded joints in the corrosive environment is attributed to an increase in the crack initiation susceptibility in the presence of corrosive media. The fractured surfaces are investigated using the scanning electron microscopy (SEM). The formation of the corrosive compounds was studied using x-ray diffractometry.     

Effect of particle grading on fracture behavior and thermal shock resistance of MgO-C refractories

Two types of MgO-C refractories with tight particle grading and non-tight particle grading were prepared according to Andreasen's continuous packing theory. Fracture behaviors were investigated using wedge splitting tests combined with digital image correlation method and acoustic emission techniques. The results indicated that MgO-C refractory with non-tight particle grading treated at 1400 ℃ had more in situ phases (e.g., AlN and MgAl₂O₄) and exhibited less brittleness than specimens with tight particle grading even though they had similar nominal tensile strengths. In contrast, specimens with non-tight particle grading had greater horizontal strain under various loading stages, reflecting their better ability to resist rupture deformation. In addition, more microcracks were initiated earlier in the pre-peak region, and more energy was consumed. The decrease in coarse particles and corresponding increase in fine powder content increased the interface between particles, benefiting for reducing the local stress concentration and improving the thermal shock resistance of refractories.