Focus-engineered coherent anti-Stokes Raman scattering microscopy: a numerical investigation

The coherent anti-Stokes Raman scattering (CARS) signal is calculated as a function of focal-field distributions with engineered phase jumps. We show that the focal fields in CARS microscopy can be shaped such that the signal from the bulk is suppressed in the forward detection mode. We present the field distributions that display enhanced sensitivity to vibrationally resonant object interfaces in the lateral dimension. The use of focus-engineered CARS provides a simple means to detect chemical edges against the strong background signals from the bulk.     

MoSe2 nanoflowers as a counter electrode for quantum dots sensitized solar cells

Journal of Materials Science: Materials in Electronics - Layered transition metal dichalcogenides hold tunable and promising photoelectrochemical properties. MoSe2 is a potential candidate of the...     

Structural and morphological investigations on DC-magnetron-sputtered nickel films deposited on Si (100)

Pure nickel thin films were deposited on Si (100) substrates under different conditions of sputtering using direct current magnetron sputtering from a nickel metal target. The different deposition parameters employed for this study are target power, argon gas pressure, substrate temperature and substrate-bias voltage. The films exhibited high density of void boundaries with reduction in <111> texture deposited under high argon gas pressures. At argon gas pressure of 5 mTorr and target power of 300 W, Ni deposition rate was ~40 nm/min. In addition, coalescence of grains accompanied with increase in the film texture was observed at high DC power. Ni films undergo morphological transition from continuous, dense void boundaries to microstructure free from voids as the substrate-bias voltage was increased from −10 to −90 V. Furthermore, as the substrate temperature was increased, the films revealed strong <111> fiber texture accompanied with near-equiaxed grain structure. Ni films deposited at 770 K showed the layer-by-layer film formation which lead to dense, continuous microstructure with increase in the grain size.     

Slag eye formation in single and dual bottom purged industrial steelmaking ladles

ABSTRACT

Argon gas is often injected from the bottom of the ladle during steel refining operations. The injected gas interacts with the liquid (metal and slag) bath and enhances the momentum, heat, and mass transfer rate in the melt. However, during these gas–liquid interactions, an opening of the slag layer called slag eye is formed, which exposes the molten metal surface to the atmosphere, which is generally undesirable. In the current work, a transient, three-dimensional mathematical model is used to study the turbulent gas–liquid interactions in single as well as dual bottom blown industrial steelmaking ladles. A Coupled Level Set Volume of Fluid (CLSVOF) model is used for tracking the steel-argon, steel-slag, and argon-slag interfaces, from which the slag-eye area has been predicted. It is found that the inlet gas purging rate, melt height, slag layer thickness, angular and radial positions of the gas inlets affect the slag opening area. Non-dimensional empirical correlations are proposed to predict the slag opening area in both single as well as dual purged ladles, using non-linear regression analysis.     

Enhanced Photocatalytic and Antibacterial Activities of ZnSe Nanoparticles

Water and microbial contamination is a serious issues to aquatic system and human health. The metal selenide has a tremendous technique to degrade the dyes and bacteria.The present work reports the synthesis of ZnSe nanoparticles in a simple co-precipitation method. The synthesized samples were analyzed by structural, optical, morphological, catalytic and biological activity. The size and bandgap by annealing temperature tuning which are confirm by X-ray Diffraction and UV–Visible spectrometer. The quasi-spherical shapes were confirmed by Scanning Electron Microscope and Transmission Electron Microscope.The photo excited electrons have trapped the metals and promoting the degradation system. The release of ions to the surface was acknowledged by Photo Luminescence spectroscopy. The photocatalytic dye degradation of the Methyl Orange showed that the enhanced activity in high temperature. The photocatalytic dye degradation activity suggested that the temperature change the production of free radicals and ROS formation. The hydroxyl radicals were slewing the dye molecules and bacteria. The obtained results giving the information of ZnSe nanoparticles are one of the fascinating research areas in the current research world. Because of its large application in different field it acts as a promoting catalytic and biological application.

Graphical Abstract

     

Multi-objective optimization for optimum tolerance synthesis with process and machine selection using a genetic algorithm

This paper presents a new approach to the tolerance synthesis of the component parts of assemblies by simultaneously optimizing three manufacturing parameters: manufacturing cost, including tolerance cost and quality loss cost; machining time; and machine overhead/idle time cost. A methodology has been developed using the genetic algorithm technique to solve this multi-objective optimization problem. The effectiveness of the proposed methodology has been demonstrated by solving a wheel mounting assembly problem consisting of five components, two subassemblies, two critical dimensions, two functional tolerances, and eight operations. Significant cost saving can be achieved by employing this methodology.     

Investigation of Ba<Subscript>2-x</Subscript>Sr<Subscript>x</Subscript>TiO<Subscript>4</Subscript>: Structural aspects and dielectric properties

Investigation of solid solution of barium-strontium orthotitanates of the type, Ba_2-x Sr _x TiO₄ (0 ≤x≤ 2), show that pure phases exist only for the end members, Ba₂TiO₄ and Sr₂TiO₄, crystallizing in the β-K₂SO₄ and K₂NiF₄ structures, respectively. The intermediate compositions (till≥ 1) lead to a biphasic mixture of two Ba₂TiO₄-type phases (probably through a spinodal decomposition) with decreasing lattice parameters, indicating Sr-substitution in both the phases. Forx > 1, Sr₂TiO₄ along with a secondary phase is obtained. The dielectric constant and dielectric loss were found to decrease with Sr substitution till the nominal composition ofx = 1. However, pure Sr₂TiO₄ shows higher dielectric constant compared to the solid solution composition. Sr₂TiO₄ shows very high temperature stability of the dielectric constant.     

Structural Basis for Intumescence – Part III – Thermal Degradation Study of Intumescent Polymers Containing Spirophosphorus Moiety in the Backbone

3,9-Dichloro-2,4,8,10-tetraoxo-3,9-disphosphaspiro-[5.5]-undecane-3,9-dioxide (spiro) was melt condensed with structurally different dihydric phenols to form poly aromatic spirophosphates. The thermal volatilization analysis showed eruptive release of gases above 300°C and the temperature region of release depends on the nature of the aromatic units incorporated in the polymer backbone. The thermal degradation in nitrogen atmosphere indicated the formation of phenol, substituted phenols, aromatics, alkyl and alkenyl substituted aromatics and condensed aromatics like azulenes, indanes and fluorenes. The source for the formation of these products is the spiropentadiene released from the spiro unit during degradation.