Synthesis, structural and thermal characterization of metaphosphatenickel(II) salt

A new inorganically template metaphosphate of Ni(II) complex has been synthesized and characterized by different measurements such as DSC, FT-IR, C?CH?CN?CS, X-RD and ICP-AES. Differential scanning calorimeter (DSC) elucidated negative specific heat of the system and has used to evaluate some thermodynamical constants like specific heat, enthalpy and entropy of that system. The specific heat capacity of the system is measured in atmospheric O₂ at heating rate of 278 and 283?K?min^?1. The specific heat is found both positive and negative at 278?K?min^?1.     

Synthesis,structural and thermal characterization of metaphosphatecobalt(II) salt

A new inorganically template metaphosphate of Co(II) complex has been synthesized and characterized by different measurements such as DSC, FT-IR, C–H–N–O–S, ESR, TG-DTA and X-RD. Differential Scanning Calorimeter (DSC) elucidated negative specific heat of the system and has used to evaluate some thermo dynamical constants like activation energy (E _a), frequency factor (A), enthalpy and entropy of that system. The specific heat capacity of the system is measured both in atmospheric O₂ and N₂ atmosphere at different heating rates of 278, 283, 293 and 298 K min⁻¹ in room atmosphere and 288 K min⁻¹ in N₂ atmosphere.     

Boundary element method for wave trapping by a multi-layered trapezoidal breakwater near a sloping rigid wall

This study examines the multiple layers in a rubble mound breakwater and their effect on reflection and dissipation of incoming ocean waves. The numerical model is developed using multi-domain boundary element method for oblique water wave trapping near a sloping wall by a multi-layered trapezoidal porous structure, which is utilized to model armour, filter and core layers while examining the hydrodynamics in different configurations. Both, the constant element and linear element approaches to boundary element method are discussed. The cases of bottom-standing porous structures as being submerged and fully extended are considered. The wave hydrodynamics over the structure is described by the reflection and dissipation coefficients along with the forces acting on the sloping wall, and is influenced by wave and structural parametrics of the system. The influence of armour layer in different configurations is highlighted for various structural and wave parameters.

     

Studies on chromium(III) complexes of some new dithiocarbamato ligands

Summary Tris-chelates of chromium(III) have been synthesised with five new dithiocarbamates, [RR'NCS₂]^–, where R=PhCH₂ and R/t'=H, PhCH₂, Me, Et and i-Pr. Magnetic moments together with electronic, i.r. and e.s.r spectra of the complexes have been described. Various ligand-field parameters have been evaluated and discussed.     

Hydroelastic analysis of very large floating structure over viscoelastic bed

Effect of viscoelastic bed on the hydroelastic response analysis of very large floating structures is studied using the linear water wave theory and small amplitude structural response in finite water depth. The floating structure is modeled using Euler–Bernoulli beam equation and the bottom bed is assumed to be viscoelastic in nature and is based on the Voigt’s model. The dispersion relation, phase speed and response amplitude of the floating structure as well as viscoelastic bed surface, pressure distribution along water depth are analyzed to study the effect of viscoelastic bed parameters, flexural rigidity of the floating structure, time period on flexural gravity wave motion. The study reveals that structural response of the floating structure can be mitigated for moderate thickness of the viscoelastic layer. Moreover, both shear modulus and viscosity of the viscoelastic layer play dominant role in reducing the structural response compared to the flexural rigidity of the structure. Further, pressure distribution within the viscoelastic bed decreases at a higher rate compared to the inviscid fluid layer irrespective of shear modulus and viscosity. The present study will be of immense help in the site selection of very large floating structures in the coastal water and installation of various marine facilities over muddy bed.     

Synthesis and thermal characterization of sulfur containing methionine bridged cobalt(III) and copper(II) complex

The sulfur containing amino acid bridging polynuclear transition metal complex has been synthesized and characterized by different measurements such as UV?CVis, FT?CIR, C?CH?CN?CS, TG?CDTA, ICP-AES, differential scanning calorimeter (DSC), and XRD. DSC has showed negative specific heat of this polynuclear system and has used to evaluate some thermodynamic constants like activation energy (E _a), frequency factor (A), enthalpy, and entropy of that system. The specific heat capacity is measured at heating rate of 10?°C?min^?1 in room atmosphere of this polynuclear complex. The characterization of this complex has showed five Co(III) and four Cu(II) atoms and this complex contained ten sulfur containing methionine amino acid units.     

Microstructure-controlled enhancement of magnetoimpedance in nanocrystalline FeSiNbBCu alloys

Rapidly solidified amorphous Fe_68.5Si_18.5Nb₃B₉Cu₁ ribbon has been subjected to heat treatment at a temperature of 550 °C for different time periods. All the annealed ribbons show the precipitation of nanocrystalline Fe₃Si phase from the amorphous phase. The estimated crystallite size from X-ray diffraction peak analysis was in the range of 15-25 nm. While the surface studies confirm the presence of a distribution of spherical nanostructures in amorphous matrix. Both magnetoimpedance and longitudinal permeability ratios are found to increase with annealing time, and attain a maximum value for 60 min annealed ribbon and decrease on further increase in the annealing time. The enhanced magnetic properties and magnetoimpedance on suitable heat treatment is attributed to the change of magnetic parameters such as anisotropy and magnetostriction, due to change in microstructure. Analysis of permeability and impedance data taken under similar conditions suggests a strong correlation between them.     

Synthesis,characterization, and thermal property of phosphate-based cobalt mixture of non-calcined,calcined, and composite material

Monatshefte für Chemie - Chemical Monthly - The phosphate-containing cobalt mixtures of non-calcined, calcined, and composite materials were synthesized in atmospheric conditions and...     

Reactivity of Aquadiethylenetriamineplatinum(II) Ion with Disulfide Moiety Cystine: A Kinetic and Mechanistic Approach

Abstract

Substitution reactions of the complex [Pt(dien)H₂O]²⁺ (where dien = diethylentriamine or 1,5-diamino-3-azapentane) with sulfur-containing L-cystine have been studied in a 1.0 × 10^?1 mol dm^?3 aqueous perchlorate medium at various temperatures (298–323 K) and 4.45 ≤ pH ≤ 2.15 using UV-vis spectroscopy. The products obtained have been characterized by their infrared and ¹H NMR datasets at various pH levels and temperatures. From infrared and ¹H NMR data, products have indicated that [Pt(dien)H₂O]²⁺ reacted with L-cystine forming a Pt–S bond at low pH. At high pH, a product complex through the Pt–N bond has been formed. All rate constants have been evaluated from nonlinear double exponential plots. The activation parameters ΔH^# and ΔS^# have been determined using the Eyring equation. The products, S_Ni, and reversible rate constants have been evaluated.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.

GRAPHICAL ABSTRACT      

Patterns in Ge cluster growth on clean and oxidized Si(111)-(7 × 7) surfaces

Ge atoms have been deposited on domain-patterned clean Si(111)-(7 × 7) and oxidized Si(111)-(7 × 7) surfaces. Clustering of Ge from the deposited Ge adatoms on these two kinds of surfaces shows contrasting patterns. On the clean Si surface, clustering predominantly occurs on domain boundaries, which include step edges on two sides. This leaves small domains denuded. Ge diffusion length has been estimated from the size of these denuded domains. For large domains, additional clustering is observed within the domains. For the oxidized Si surface, the pattern formation is in sharp contrast with that for the clean Si surface. In this case the domain boundaries remain relatively empty and there is strong clustering within the domains leading to the formation of dense Ge nanoislands within the domains. This contrasting pattern formation has been explained via a reaction diffusion model.