Modulated Binary–Ternary Dual Semiconductor Heterostructures

A generic modular synthetic strategy for the fabrication of a series of binary‐ternary group II‐VI and group I‐III‐VI coupled semiconductor nano‐heterostructures is reported. Using Ag₂Se nanocrystals first as a catalyst and then as sacrificial seeds, four dual semiconductor heterostructures were designed with similar shapes: CdSe‐AgInSe₂, CdSe‐AgGaSe₂, ZnSe‐AgInSe₂, and ZnSe‐AgGaSe₂. Among these, dispersive type‐II heterostructures are further explored for photocatalytic hydrogen evolution from water and these are observed to be superior catalysts than the binary or ternary semi‐conductors. Details of the chemistry of this modular synthesis have been studied and the photophysical processes involved in catalysis are investigated.     

Effects of Hall current and slip condition on unsteady flow of a viscous fluid due to non-coaxial rotation of a porous disk and a fluid at infinity

The unsteady hydromagnetic flow due to non-coaxial rotations of a porous disk with slip condition and a fluid at infinity has been studied on taking Hall currents into account. An exact solution of the governing equation has been obtained by the Laplace transform technique. Asymptotic solution is obtained for large time. It is found that for large time there exists a thin boundary layer near the disk. The thickness of this layer decreases with increase in either suction or magnetic parameter.     

Unsteady Couette flow in a rotating system

The unsteady Couette flow between two infinite horizontal plates induced by the non-torsional oscillations of one of the plates in a rotating system under the boundary layer approximations is investigated. An exact solution of the governing equations has been obtained by using Laplace transform technique. It is shown that when the oscillating plate situated at an infinite distance from stationary plate then the problem reduces to the unsteady boundary layer problem in a rotating system with non-torsional oscillations of the free-stream velocity.     

A Perylene diimide based fluorescent probe for caffeine in aqueous medium

Caffeine is a legal stimulant drug which has received considerable attention due to its widespread use as a beverage and in pharmaceutical formulations. However, reported chemosensors for caffeine are limited. In the present study use of a perylene diimide (PDI) derivative has been explored for the first time for detection and quantification of caffeine in an aqueous medium. Spectroscopic studies (UV-Vis, Fluorescence, FTIR and 1H-NMR) suggest that aspartic acid modified perylene diimide (PASP) may bind to caffeine through π-π interaction. This interaction results in immediate quenching of fluorescence and optical color change which can be perceived through naked eyes. This probe has been successfully used for bio-imaging of caffeine in living cells.     

Oscillatory Couette flow in the presence of an inclined magnetic field

Oscillatory MHD Couette flow of electrically conducting fluid between two parallel plates in a rotating system in the presence of an inclined magnetic field is considered when the upper plate is held at rest and the lower plate oscillates non-torsionally . An exact solution of the governing equations has been obtained by using Laplace transform technique. Asymptotic behavior of the solution is analyzed for M ² ≪1, K ² ≪1 and ω ≪1 and for large M ², K ² and ω. Numerical results of velocities are depicted graphically and the frictional shearing stresses are presented in tables. It is found that a thin boundary layer is formed near the lower plate, for large values of rotation parameter K ², Hartman number M ² and frequency parameter ω. The thickness of this boundary layer increases with increase in inclination of the magnetic field with the axis of rotation.     

The Role of Heterogeneous Nucleation in the Activation of Blood Cells

Physics of the Solid State - The processes of receptors clusterization on the surface of blood cells are considered in the framework of nucleation theory. In the absence of ligands, the...     

Multi‐Objective Optimization of a Batch Copoly(ethylene‐polyoxyethylene terephthalate) Reactor Using Different Adaptations of Nondominated Sorting Genetic Algorithm

Summary: A multi‐objective optimization is carried out for a copoly(ethylene‐polyoxyethylene terephthalate) (CEPT) batch reactor using different adaptations of the elitist nondominated sorting genetic algorithm (NSGA‐II). Several two objective function problems are formulated and solved. One objective is to minimize the total copolymerization time and other objective is to minimize the formation of total undesirable side products, namely, acid end group, vinyl ester end group, diethylene glycol ester end group of polyethylene terephthalate, and diethylene glycol. End‐point constraint is incorporated to obtain the specified number‐average degree of copolymerization. The operating temperature history of batch CEPT reactor is the only important decision variable for first optimization problem, whereas operating temperature history and molar ratio of feed to the reactor are taken as decision variables for the second optimization problem. Optimal Pareto frontiers are obtained for both the problems studied. In order to operate the polymerization reactor optimally, it is found that higher isothermal temperature history is needed for short copolymerization time, whereas lower nonisothermal temperature history is required for higher copolymerization time. The results of NSGA‐II technique are analyzed and compared with the jumping gene (JG) and adapted jumping gene (aJG) operator in NSGA‐II separately. It is found that NSGA‐II‐JG is superior to NSGA‐II and NSGA‐II‐aJG.

Optimization of a batch copoly(ethylene‐polyoxyethylene terephthalate) reactor.     

Chemically Tailoring the Dopant Emission in Manganese-Doped CsPbCl3 Perovskite Nanocrystals

Doping in perovskite nanocrystals adopts different mechanistic approach in comparison to widely established doping in chalcogenide quantum dots. The fast formation of perovskites makes the dopant insertions more competitive and challenging. Introducing alkylamine hydrochloride (RNH₃Cl) as a promoting reagent, precise controlled doping of Mn^II in CsPbCl₃ perovskite nanocrystals is reported. Simply, by changing the amount of RNH₃Cl, the Mn incorporation and subsequent tuning in the excitonic as well as Mn d–d emission intensities are tailored. Investigations suggested that RNH₃Cl acted as the chlorinating source, controlled the size, and also helps in increasing the number of particles. This provided more opportunity for Mn ions to take part in reaction and occupied the appropriate lattice positions. Carrying out several reactions with varying reaction parameters, the doping conditions are optimized and the role of the promoting reagent for both doped and undoped systems are compared.     

Loss of Stability of the Blood Liquid State and Assessment of Shear-Induced Thrombosis Risk

Radiophysics and Quantum Electronics - The loss of stability of the blood liquid state causes changes in the blood aggregation, resulting in thrombus formation. Intravascular thrombus formation is...