Synthesis and Structural Characterization of Two New Nano-Coordination Compounds Based on Mercury(II) NN Donor Schiff Base

Two new nano mercury(II) coordination compounds, [Hg₂(μ-L1)(μ-I)₂I₃]_n (1) and [Hg(L2)(I)₂] (2) {L1?=?(E)-N′-(pyridin-2-ylmethylene)isonicotinohydrazide and L2?=?(E)-N′-(1-(pyridin-2-yl)ethylidene)isonicotinohydrazide} have been synthesized by a sonochemical method. The new nano-structures were characterized by scanning electron microscopy, X-ray powder diffraction, elemental analysis and IR spectroscopy. The compounds were also characterized by single crystal X-ray diffraction and the results indicate a 1D fishbone-like structure containing dinuclear units for 1 and a mononuclear structure for 2. In coordination polymer 1, the two Hg(II) centers are four coordinate into a chain-axis and also in the terminal linkages. In complex 2, the Hg(II) center is four coordinate. The chains of polymer 1 interact with each other through π–π stacking interactions which create a 3D framework.     

Experimental Study and Mathematical Modeling of Green Pea Drying in a Spouted Bed

In this study, green pea drying is investigated experimentally in a laboratory-scale spouted bed dryer. A mathematical model is also developed to investigate the effect of operating conditions on the performance of the system. The effect of operating parameters such as inlet air temperature, particle size, and flow rate of the drying air on the performance of the dryer are studied experimentally. In order to build the process model, it is necessary to analyze the transport in both solid and gas phases. A complete set of equations with no adjustable parameters is derived for existing zones in the spouted bed dryer in order to predict variations in the temperature and moisture content of the solid and gas phases with time for batch drying conditions. Model results are compared with corresponding experimental data. Agreement between the model results and experimental data is good.     

Efficiency of mixed hybrid finite element and multipoint flux approximation methods on quadrangular grids and highly anisotropic media

The mixed hybrid finite element (MHFE) and the multipoint flux approximation (MPFA) methods are well suited for anisotropic heterogeneous domains since both are locally conservative and can handle general irregular grids. In this work, behaviours and performances of MHFE and MPFA methods are studied numerically for different heterogeneities and anisotropy factors on parallelograms and then on a more general quadrilateral grid. The superiority of MPFA in terms of accuracy and efficiency is clearly demonstrated for parallelogram grids. In the case of more general quadrilateral grids, MPFA becomes more central processing unit time consuming than MHFE. For high anisotropy factors, both methods give results with significant non‐physical oscillations. Copyright © 2008 John Wiley & Sons, Ltd.     

Sunil de Silva-A Scientist and a Visionary

The objective of this work was to analyze the behavior of good conducting granules in a newly designed plate-type electrostatic separator. Commercial software was employed for the numerical analysis of the electric field generated by an original electrode configuration. This enabled the evaluation of the electric charge and forces on conducting particles. The trajectory of a single particle was calculated over a set of 1300 points. The simulated results show that the trajectories depend on the applied voltage, the radius, and the mass density of the granules. They were found in good agreement with the experiments carried out on a laboratory electrostatic separator.     

Experimental Modeling of the Electrostatic Separation of Granular Materials

This article aims at demonstrating the interest the design of experiment methodology might present for modeling and optimization of a typical electrostatic separation process. A classical 2³ full-factorial design followed by a composite design were employed for carrying out experiments on the selective sorting of conductive and nonconductive particles contained in a granular mixture. The study was performed on a roll-type corona-electrostatic separator, with samples prepared from genuine electric cable wastes, composed of 5% copper and 95% PVC. The response function was the mass of the middling fraction collected after separation, the factors under investigation being the high-voltage level, the speed of the rotating roll electrode, and the angular position of the splitter between the copper and middling compartments of the collector. By using commercial design of experiments software, it was possible to estimate the effects of these factors and then derive the model of the process as a quadratic polynomial function. This model served at predicting the optimal set point of the process. The results reported support design of experiments methodology as an efficient tool for the optimization of industrial electrostatic separation processes.     

Study on analytical methods for quantifying the non‐adsorbed reactive dye forms in an exhausted dyebath

Reported herein are the results of an analysis of the compatibility of three methods for quantifying the non‐adsorbed forms of reactive dyes, in an exhausted dyebath, of the type monochlorotriazine/β‐sulphatoethylsulphone used in dyeing cellulosic fibres (cotton). The first method is based on spectrophotometric analysis and involves measuring the absorbance of the residual dyebath (after the dyeing process), the second is based on colorimetric analysis and involves measuring the reflectance of the dyed fabric and the third is based on high‐performance liquid chromatography. The purpose of the latter is to identify and quantify the non‐adsorbed dye forms in the residual dyebath. The calculated exhaustion values unequivocally prove the reliability and compatibility of these methods.     

Direct Synthesis of CdO Nanoparticles from a Novel Nano-Rods Cadmium(II) 4,4-Difluoro-1-phenyl-1,3-butanedionate Nano Coordination Compound

A novel nano-rods cadmium(II) fluorine-substituted β-diketonate, [Cd(2,2′-bpy)(dfpb)₂] (1), (2,2′-bpy = 2,2′-bipyridine; dfpb = 4,4-difluoro-1-phenyl-1,3-butandion) has been synthesized by a sonochemical method that produces the coordination compound with nano dimensions. The new nanostructure was characterized by scanning electron microscopy, X-ray powder diffraction (XRD) elemental analysis and IR spectroscopy. Compound 1 was structurally characterized by single crystal X-ray diffraction. The single-crystal structure of this complex shows that the coordination number of the Cd^II ions is six with two N-donor atoms from the 2,2′-bpy ligand and four O-donors from two dfpb. Self-assembly of the complex occurs through CH···F–C and π–π stacking interactions. The supramolecular features of 1 are controlled by weak directional intermolecular interactions. CdO nanoparticles were obtained by thermolysis of 1 at 180 °C with oleic acid as a surfactant. The average diameter of the nanoparticles was estimated by the Scherrer equation to be 20 nm. The morphology and size of the CdO samples were further observed using SEM.     

Synthesis and Crystal Structure of [Pb(phen)(μ-N3)(μ-NO3)]n and Its Thermal Decomposition to PbO Nanoparticles

Nano rods of a new 1D polymeric lead(II) complex containing the Pb₂-(μ-N₃)₂ motif, [Pb(phen)(μ-N₃)(μ-NO₃)]_n (phen?=?1,10-phenanthroline), has been synthesized by a sonochemical method. The new nano-structure was characterized by scanning electron microscopy, X-ray powder diffraction, elemental analyses and IR spectroscopy. A single crystalline material was obtained by applying a heat gradient to a solution of reagents. The single crystal X-ray data showed the coordination number of the Pb²⁺ ions to be eight (PbN4O4), with the Pb²⁺ ions having “stereo-chemically active” electron lone pairs; the coordination sphere was hemidirected. The chains of [Pb(phen)(μ-N₃)(μ-NO₃)]_n interact with each other via π–π interactions to create a 3D framework. PbO nanoparticles were obtained by thermolysis of 1 at 180?°C with oleic acid as a surfactant. The average diameter of the nanoparticles was estimated to be 33?nm by the Scherrer equation. The morphology and size of the prepared PbO samples were further observed using SEM.