Effect of Powder Metallurgy Process and its Parameters on the Mechanical and Electrical Properties of Copper-Based Materials: Literature Review

Powder Metallurgy and Metal Ceramics - As the world is shifting towards renewable sources of energy, the demand for copper is increasing due to its excellent electrical and corrosion resistance...     

Integration of moment invariants and uniform local binary patterns for human activity recognition in video sequences

Multimedia Tools and Applications - In this study, we present a method for human activity recognition in video sequences. Human activities are often described by a holistic feature vector...     

Sensitivity Analysis of Junction Free Electrostatically Doped Tunnel-FET Based Biosensor

Silicon - The electrostatic doping technique has a remarkable ability to reduce random dopant fluctuations (RDFs), fabrication complexity and high thermal budget requirement in the fabrication...     

Experimental and Numerical Study of Discharge Capacity and Sediment Profile Upstream of Piano Key Weirs with Different Plan Geometries

Piano key weirs (PKWs) are an improved form of labyrinth weirs, which are becoming popular as a more hydraulically efficient and cost-effective type of weir over its counterparts for both spillway and river flow conditions. More than thirty PKWs are already in construction worldwide, with constructions in India at Swara Kuddu. More than twenty parameters influence the flow over a PKW, and as such, the flow hydraulics near PKW is complex. It is imperative to study the performance of different shapes of PKW to know which shape offers more hydraulically and cost-effective advantages over other shapes. The present study combines the experimental and numerical study of discharge capacity and sediment carrying capacity of the different plan geometries of PKW. The experimental study of the discharging capacity of PKW has been carried out at eighteen discharge points for three plan geometries of PKW. A numerical study using ANSYS FLUENT has also been carried out at five discharges and compared with the experimental results. Vertical velocity near a weir is an essential factor facilitating the uplift of sediment. Sediment profile in the channel has been studied at three discharges experimentally for two types of PKWs: RPKW and TPKW6, all for free-flow conditions. The numerical study has also been carried out at these experimental discharges for studying the vertical component of velocity (v) upstream of PKW. An attempt has been made to isolate critical areas where the sediments are being lifted by the turbulence mechanism, thus helping them pass over the weir. The study shows PKW with a rectangular plan (RPKW) to be more hydraulically efficient than TPKWs with six-degree and thirteen-degree lateral crest variations (TPKW6 & TPKW13). The study also shows RPKW to be more self-cleaning in nature than its trapezoidal counterpart (TPKW6). Numerical study shows a close resemblance to the experimental results with errors well within permissible limits implying its greater use in ascertaining complex flows around hydraulic structures.

     

CED-Net: context-aware ear detection network for unconstrained images

Pattern Analysis and Applications - Personal authentication systems based on biometric have seen a strong demand mainly due to the increasing concern in various privacy and security applications....     

Optimal Sensing and Transmission of Energy Efficient Cognitive Radio Networks

Wireless Personal Communications - The issue of spectrum scarcity can be alleviated by the cognitive radio technology with efficient spectrum sensing and allocation of free spectrum bands....     

Preparation,characterization, and optical properties of a chitosan–anthraldehyde crosslinkable film

A novel chitosan–anthraldehyde derivative film was prepared by the reaction of 79% deacetylated chitosan with 9‐anthraldehyde with a hydrogel by a solution casting method. The prepared chitosan derivative film was confirmed by ultraviolet–visible absorption spectroscopy of the absorption peak at 266 nm due to the presence of an anthracene ring. The crosslinking reaction showed significant changes in the Fourier transform infrared spectrum of the chitosan derivative film. The characteristic peak of CH?N stretching bands at 1610 cm^?1 confirmed the formation of a Schiff base after the reaction of chitosan with 9‐anthraldehyde. The film was evaluated by X‐ray diffraction, scanning electron microscopy, photoluminescence spectroscopy, and second harmonic generation (SHG). The nature of the crystallinity of the chitosan derivative from X‐ray diffraction analysis confirmed that the film may have had nonlinear optical properties. The chitosan derivative showed a redshifted emission maximum because of the electron‐rich polymer main chain. No reabsorption of the second harmonic signal and no resonance enhancements were noticed during the SHG study; this indicated that the chitosan derivative possessed SHG ability. Overall, the chitosan derivative film opens new perspectives for optical material for biomedical applications. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

A first principle study of SO3 decomposition on silver nano-clusters: Implications toward hydrogen production

In this work, based on first principles density functional theory, we have investigated the interaction of SO₃ molecule on three different substrates; (i) clean Al₂O₃ surface (0001) (ii) an isolated Ag₆ cluster and (iii) Ag₆ clusters deposited on the Al₂O₃ surface. All calculations were carried out using the plane wave based pseudopotential method under the framework of density functional theory. For the clean Al₂O₃ surface, the SO₃ molecule was adsorbed in parallel orientation on the surface resulting in an elongation of the S–O bond from 1.44 to 1.52 Å with interaction energy of 1.67 eV. In contrast, the interaction of SO₃ with Ag₆ was found to be weak with 0.4 eV interaction energy and 1.47 Å as the largest S–O bond length. Remarkably, when SO₃ molecule interacted with Ag₆ cluster deposited on the Al₂O₃ support, the binding was found to be higher than both Al₂O₃ and Ag₆ clusters in their isolated state. In particular, upon adsorption of SO₃ on Ag₆/@Al₂O₃, the S–O bond length was found to increases from 1.44 to 1.64 Å and the interaction energy was estimated to be 2.00 eV. As the bond elongation bears the signature of bond weakening, a comparison of the above three results clearly suggests that the dissociation barrier of S–O bond on the Ag₆@Al₂O₃ support will be significantly lower than that on the isolated Ag₆ or Al₂O₃ surface. The nature of chemical interaction of SO₃ on these three systems has been discussed based on the electronic density of states analysis.     

Seasonal variation in content,chemical composition and antimicrobial and cytotoxic activities of essential oils from four Mentha species

BACKGROUND: The aim of the present study was to appraise variation in the chemical composition, and antimicrobial and cytotoxic activities of essential oils from the leaves of four Mentha species—M. arvensis, M. piperita, M. longifolia and M. spicata—as affected by harvesting season. Disc diffusion and broth microdilution susceptibility assays were used to evaluate the antimicrobial activity of Mentha essential oils against a panel of microorganisms. The cytotoxicity of essential oils was tested on breast cancer (MCF‐7) and prostate cancer (LNCaP) cell lines using the MTT assay. RESULTS: The essential oil contents of M. arvensis, M. piperita, M. longifolia and M. spicata were 17.0, 12.2, 10.8 and 12.0 g kg^?1 from the summer and 9.20, 10.5, 7.00 and 9.50 g kg^?1 from the winter crops, respectively. Gas chromatographic–mass spectrometric analysis revealed that mostly quantitative rather than qualitative variation was observed in the oil composition of each species. The principal chemical constituents determined in M. arvensis, M. piperita, M. longifolia and M. spicata essential oils from both seasons were menthol, menthone, piperitenone oxide and carvone, respectively. The tested essential oils and their major components exhibited notable antimicrobial activity against most of the plant and human pathogens tested. The tested essential oils also exhibited good cytotoxicity potential. CONCLUSION: Of the Mentha essential oils tested, M. arvensis essential oil showed relatively better antimicrobial and cytotoxic activities. A significant variation in the content of most of the chemical components and biological activities of seasonally collected samples was documented. Copyright © 2010 Society of Chemical Industry