Ionic size dependent electroosmosis in ion‐selective microchannels and nanochannels

Electrokinetics in salt‐free media (in which counterions are only present) is central to the performance of many systems of modern technological relevance, ranging from ion‐selective nanopores to electronic papers. Here, we introduce an analytical theory to describe the size dependence of electroosmosis in such typical scenarios, exhibiting an interesting confluence of the implications of interdependence of the electroosmotic transport mechanisms, ionic sizes, and confinement dimensions along with the counterion concentration. Our results do reveal that the concerned mobility parameter, describing the strength of electroosmotic transport, increases simultaneously with increments in the surface charge density as well as an ionic size factor (also known as the steric factor), bearing far‐ranging consequences in microfluidic and nanofluidic technology.     

Vibrational dynamics of Ni-glassy alloys

The well known model potential is used to investigate the vibrational properties of some Ni-based binary glassy alloys using three theoretical models. Different local field correction functions are employed to see the effect of exchange and correlation in the aforesaid properties and have been found successful.     

Superconducting state parameters of CuCZr100-C metallic glasses

The theoretical investigation of the superconducting state parameters (SSP) viz. electron-phonon coupling strength λ, Coulomb pseudopotential μ*, transition temperature T _c, isotope effect exponent α and effective interaction strength N ₀ V of ten Cu _C Zr_100−C metallic glasses have been reported using Ashcroft’s empty core (EMC) model potential. Three local field correction functions proposed by Hartree (H), Taylor (T) and Ichimaru-Utsumi (IU) are used in the current investigation to study the screening influence on the aforesaid properties. It is observed that the electron-phonon coupling strength λ and the transition temperature T _C are quite sensitive to the selection of the local field correction functions, whereas the Coulomb pseudopotential μ*, isotope effect exponent α and effective interaction strength N ₀ V show weak dependences on local field correction functions. The T _c obtained from IU-local field correction function are found an excellent agreement with available theoretical or experimental data. Also, the present results are found in qualitative agreement with other such earlier reported data, which confirms the superconducting phase in metallic glasses.      

Comparison of SOLPS5.0 and SOLPS-ITER simulations for ASDEX upgrade L-mode

This paper examines the backward compatibility of SOLPS-ITER with SOLPS5.0 and produces a basic test of the physics/numerics improvements/additions in SOLPS-ITER recommended by developers, taking an ASDEX Upgrade L-mode simulation as an example. SOLPS-ITER, which is emerging as the most advanced tool for edge plasma modelling, can be instructed to mimic SOLPS5.0 physics/numerics. This allows producing a detailed comparison of the two codes, in a framework where they are expected to produce the similar results, thus raising the confidence in using SOLPS-ITER to continue SOLPS5.0 simulations. Under such framework, SOLPS-ITER results match well with those of SOLPS5.0. The remaining differences might be from the ion energy source, and a full benchmark activity is expected to solve this in the future. We then test the effect of the recommended physics/numerics introduced in SOLPS-ITER with respect to the widely used SOLPS5.0. Only deuterium shots are considered as the basic test, where the recommended physics/numerics are simple and expected not to change the simulation results significantly. Electron density and temperature on divertor targets are the key metrics in this study, instead of particle fluxes and power load. Numerical simulations show that the effect of the recommended physics/numerics on the final solution results in only ∼5% differences in the outer mid-plane and target profiles of electron density and temperature. An upstream density scan, covering the full range from attached to detached conditions, also produces closely matching results (∼10% differences). Thus, we believe that recommended physics/numerics do not introduce unwanted spurious effects and are confident about future modelling results of SOLPS-ITER.     

Hydrodynamic Dispersion and Lamb Surfaces in Darcy Flow

Transport in Porous Media - Transport processes such as the dispersion and mixing of solutes are governed by the interplay of advection and diffusion, where advection acts to organise fluid...     

An Asymptotic-Numerical Method for a Class of Weakly Coupled System of Singularly Perturbed Convection-Diffusion Equations

A weakly coupled convection dominated system of m-equations is analyzed. A higher order accurate asymptotic-numerical method is presented. The solutions of convection dominated problem are known to exhibit multi-scale character. There exist narrow region across the boundary of the domain where the solution exhibit steep gradient. This region is termed as boundary layer region and the solution of problem is said to have a boundary layer. Outside of this region, the solution of system behaves smoothly. To capture this multi-scale nature given system is factorized into two explicit systems. The degenerate system of initial value problems (IVPs), obtained by setting ??=?0, corresponds to the smooth solution, which lies outside of boundary layers. For solution inside boundary layers, a system of boundary value problems (BVPs) is obtained using stretching transformation. Regardless of this simple factorization, solutions of these systems preserve the key features of the given coupled system. Runge–Kutta method is used to solve the degenerate system of IVPs, whereas the system of BVPs is solved analytically. Stability and consistency of the proposed method is established. A uniform convergence of higher order is obtained. Possible extension to differential difference equations are also brought to attention. A comparative study of the present method with some state of art existing numerical schemes is carried out by means of several test problems. The results so obtained demonstrate the effectiveness and potential of present approach.     

Bio-Assisted Preparation of Nano Zinc Oxide and Its Behavior Towards Textile Azo Pollutants

High Energy Chemistry - Recent reports on nanoparticles rise significantly as they possess numerous applications in medical, material science, optics, and bioscience etc. Nanoparticles show unique...     

Benzyl isobornyl amines: a simple and practical class of NMR discriminating agents for effective chiral recognition of acids

The design and synthesis of a few simple N-benzyl derivatives of isobornyl amine is presented. The derivatives have been assessed as chiral solvating agents for effective discrimination of the signals of some acids in NMR analysis. The single crystal X-ray analysis of the salts of (R)-mandelic acid with two of the title derivatives help to understand the supramolecular interactions and assign the induced chemical shifts in ¹H NMR analysis. The title derivative is found to be suitable for quantitative determination of the enantiomeric excess of unknown enantiomeric purity as well as being efficient in resolving racemic mandelic acid.