Five coordinated complexes of divalent nickel and copper with ligands derived from acid hydrazides and acetylacetone

Summary Picolinic acid hydrazide (PH) and isonicotinic acid hydrazide (INH) react with acetylacetone to form complexes, containing open chain tetradentate ligands, through anin situ process in the presence of nickel and copper salts. The complexes were isolated and characterised as five-coordinate with the aid of analyses, magnetic, e.s.r., electronic and i.r. spectral studies.Attempts to obtain the free ligand were unsuccessful, but its solid complexes can be isolated. Acetylacetonebispicolinoyl hydrazone Ac(PH)₂ coordinates through azomethine and pyridine nitrogen atoms while acetylacetonebisisonicotinoyl hydrazone Ac(INH)₂ does so through azomethine nitrogens and amido oxygen atoms, giving rise to complexes of the MAc(PH)₂X or MAc(INH)₂X type where X=Cl, Br, NO₃ or NCS and M=nickel(II) and copper(II). Magnetic, e.s.r. and electronic spectra are consistent with five coordinate geometries incorporating one anion on the axial positions. Various ligand field parameters have been calculated and the amount of distortion assessed in terms of DT/DQ. The metal-ligand vibrations in the far i.r. are discussed.     

An application of <Emphasis Type="Italic">H</Emphasis>-differentiability to nonnegative and unrestricted generalized complementarity problems

This paper deals with nonnegative nonsmooth generalized complementarity problem, denoted by GCP(f,g). Starting with H-differentiable functions f and g, we describe H-differentials of some GCP functions and their merit functions. We show how, under appropriate conditions on H-differentials of f and g, minimizing a merit function corresponding to f and g leads to a solution of the generalized complementarity problem. Moreover, we generalize the concepts of monotonicity, P ₀-property and their variants for functions and use them to establish some conditions to get a solution for generalized complementarity problem. Our results are generalizations of such results for nonlinear complementarity problem when the underlying functions are C ¹, semismooth, and locally Lipschitzian.     

Two-component modeling for non-Newtonian nanofluid slip flow and heat transfer over sheet: Lie group approach

The present paper deals with the multiple solutions and their stability analysis of non-Newtonian micropolar nanofluid slip flow past a shrinking sheet in the presence of a passively controlled nanoparticle boundary condition. The Lie group transformation is used to find the similarity transformations which transform the governing transport equations to a system of coupled ordinary differential equations with boundary conditions. These coupled set of ordinary differential equation is then solved using the RungeKutta-Fehlberg fourth-fifth order(RKF45) method and the ode15 s solver in MATLAB.For stability analysis, the eigenvalue problem is solved to check the physically realizable solution. The upper branch is found to be stable, whereas the lower branch is unstable. The critical values(turning points) for suction(0 sc s) and the shrinking parameter(χc χ 0) are also shown graphically for both no-slip and multiple-slip conditions. Multiple regression analysis for the stable solution is carried out to investigate the impact of various pertinent parameters on heat transfer rates. The Nusselt number is found to be a decreasing function of the thermophoresis and Brownian motion parameters.     

Free Convective Nonaligned Non-Newtonian Flow with Non-linear Thermal Radiation

The present study explores the free convective oblique Casson fluid over a stretching surface with non-linear thermal radiation effects. The governing physical problem is modelled and transformed into a set of coupled non-linear ordinary differential equations by suitable similarity transformation, which are solved numerically with the help of shooting method keeping the convergence control of 10^-5 in computations. Influence of pertinent physical parameters on normal, tangential velocity profiles and temperature are expressed through graphs. Physical quantities of interest such as skin friction coefficients and local heat flux are investigated numerically.     

Galerkin Finite Element Study on the Effects of Variable Thermal Conductivity and Variable Mass Diffusion Conductance on Heat and Mass Transfer

This article investigates the effects of variable thermal conductivity and variable mass diffusion coefficient on the transport of heat and mass in the flow of Casson fluid. Numerical simulations for two-dimensional flow induced by stretching surface are performed by using Galerkin finite element method (GFEM) with linear shape functions. After assembly process, nonlinear algebraic equations are linearized through Picard method and resulting linear system is solved iteratively using Gauss Seidal method with simulation tolerance 10^-8. Maximum value of independent variable η is searched through numerical experiments. Grid independent study was carried out and error analysis is performed. Simulated results are validated by comparing with already published results. Parametric study is carried out to explore the physics of the flow. The concentration increases when mass diffusion coefficient is increased. The concentration and thermal boundary layer thicknesses increase when ε₁ and ε are increased. The effect of generative chemical reaction on concentration is opposite to the effect of destructive chemical reaction on the concentration.     

Effect of Martensite Volume Fraction on Strain Partitioning Behavior of Dual Phase Steel

Monotonic deformation behavior of ferrite-martensite dual phase steels with martensite volume of 13-43% have been analyzed in the current investigation using micromechanics based finite element simulation on representative volume elements. The effects of martensite volume fraction on the strain partitioning behavior between soft ferrite matrix and hard martensite islands in dual phase steels during tensile deformation have been investigated. As a consequence of strain incompatibility between hard martensite and soft ferrite phases, inhomogeneous deformation and finally deformation localization occur during tensile deformation. Restricted local deformation in ferrite phase caused by the adjacent martensite islands triggers the local stress triaxiality development. As the martensite volume fraction increases, the local deformation restrictions in ferrite phase also increases and which results in higher stress triaxiality development. Similarly the strain partitioning behavior between ferrite matrix and martensite island is also influenced by the volume fraction of martensite. The strain partitioning coefficient increases with increasing martensite volume fraction.     

Planar Channelling Criticalities of MeV Protons in Si Crystal: Simulations, Evaluation and Applications

We reports a phase-space structure of MeV proton beam planar channelled along {110} planes in Si crystal using simulation results with the help of a computer code FLUX. The aim is to understand channelling conditions suitable for disorder measurement in crystals. Phase-space distribution of a planar channelled proton beam evolutes in a systematic fashion when it travels into the crystal. Planar channelled beam oscillates between phase-like and space-like conditions in which a part of the beam becomes under phase and space criticalities. These criticality conditions in planar channelling are analysed, explained and discussed with the perspective of defect measurement in crystals.     

Dirac Nodal Arc Semimetal PtSn4: An Ideal Platform for Understanding Surface Properties and Catalysis for Hydrogen Evolution

Conductivity, carrier mobility, and a suitable Gibbs free energy are important criteria that determine the performance of catalysts for a hydrogen evolution reaction (HER). However, it is a challenge to combine these factors into a single compound. Herein, we discover a superior electrocatalyst for a HER in the recently identified Dirac nodal arc semimetal PtSn₄. The determined turnover frequency (TOF) for each active site of PtSn₄ is 1.54 H₂ s^?1 at 100 mV. This sets a benchmark for HER catalysis on Pt‐based noble metals and earth‐abundant metal catalysts. We make use of the robust surface states of PtSn₄ as their electrons can be transferred to the adsorbed hydrogen atoms in the catalytic process more efficiently. In addition, PtSn₄ displays excellent chemical and electrochemical stabilities after long‐term exposure in air and long‐time HER stability tests.