Thermolysis Synthesis of Pure Phase Nano-Sized Cobalt(II) Oxide from Novel Cobalt(II)-Pyrazole Discrete Nano Coordination Compound

Nano-structures of a new discrete coordination compound of divalent cobalt with the pyrazol (pzH) containing the terminal isothiocyanate anions, [Co(pzH)₂(NCS)₂] (1), with discrete molecular architecture in solid state was synthesized by a sonochemical method. The new nanostructure was characterized by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray powder diffraction, IR, and elemental analysis. The supramolecular features in these complexes are guided and controlled by weak directional intermolecular interactions. The discrete molecules interact with each other through labile interactions creating a 3D supramolecular framework. The CoO nanoparticles were obtained by thermolysis of 1 at 180 °C with oleic acid as a surfactant.     

Synthesis, Structural Investigation and DFT Calculations of Cadmium (II) Fluorine-Substituted β-Diketonate: A Precursor to Producing Pure Phase Nano-Sized Cadmium (II) Oxide

A novel aza-aromatic base adduct of a cadmium(II) fluorine-substituted β-diketonate, [Cd(dmp)(ttfa)₂]_n(1), (“dmp” is an abbreviation for 2,9-dimethyl-1,10-phenanthroline and “ttfa” is an abbreviation for thenoyltrifluoroacetonate) was synthesised and characterised by elemental analysis and IR, ¹H NMR and ¹³C NMR spectroscopy and studied by thermal as well as X-ray crystallography. The single-crystal structure of this complex shows that the coordination number of the Cd²⁺ ion is six with two N-donor atoms from the dmp ligand and four O-donors from ttfa. Self-assembly of this complex was mediated by CH···F–C and π–π stacking interactions. The supramolecular features of these complexes are controlled by weak directional intermolecular interactions. The structural energy of the title complex was determined by density functional theory calculations. The calculated HOMO–LUMO gap is 0.131 a.u. (3.474?eV). The CdO nano-particles were obtained by thermolysis of 1 at 180?°C with oleic acid as the surfactant. Scanning electron microscopy showed that the size of the CdO particles is ~35?nm.     

The quality‐constrained scheduling problem in plastics compounding

Interest is increasing in plastic compounding plants that offer tailor‐made resins. Such plants produce a wide range of products in small quantities and with frequent changeovers. The underlying scheduling problem has been extensively researched; however, the concept of incorporating qualities of the finished product in the problem of plastics compounding has not been considered. We express product qualities as an additional problem constraint so that the production schedule ensures product quality. The additional constraint makes this mixed integer nonlinear program (MINLP) problem more difficult to solve. Several case studies are solved to illustrate the utility of the proposed approach. Experiments demonstrated that qualities of the finished product can be ensured a priori if the appropriate relations are developed and integrated in the optimisation model. As well, this paper provides insight into the economic aspects of the scheduling problem under consideration. Experiments showed that none of the cost components (operation, raw material, inventory, penalty or utilities) can alone play the role of the optimisation criterion. © 2012 Canadian Society for Chemical Engineering     

A comparative study of an industrial effluent treatment using enzymatic and alkaline adapted consortium assays

BACKGROUND: Dyeing effluents are the main source of water pollution from textile industries. Consequently, the treatment of such effluents is of environmental concern. RESULTS: Decolorization of a textile industry effluent was investigated using, for the first time, the trimeric Scytalidium thermophilum laccase without mediator addition. The maximum effluent decolorization (50%) was achieved after 8 h using a diluted effluent (5 fold) and 4 units of crude enzyme, operating at 50 °C and pH 4. Characterization of raw effluent presents two peaks as demonstrated by the UV‐visible spectrum, showing an intensive peak around 670 nm and a smaller one at 290 nm. At the end of the enzymatic treatment, these two peaks disappeared and a new peak emerged at 280 nm. Because laccase catalyzed effluent decolorization percentage did not exceed 50%, an alkaline adapted consortium treatment assay of this effluent was carried out. An alkaline adapted consortium was used at bench scale in order to decolorize the raw effluent. After 24 h of exposure, color and COD (chemical oxygen demand) removal rates reached 73% and 71%, respectively, at pH 11. CONCLUSION: The adapted consortium treatment of the industrial effluent is economically very interesting since the treatment is costless and can be applied at pilot or industrial scales. © 2012 Society of Chemical Industry     

A Fast and Reliable Tool for Estimates for Plastic Blowing Moulds

This work presents a procedure to evaluate machining costs of dies made on CNC machines. Our survey deals with companies manufacturing plastic blowing moulds, and it is limited to the unit parts, that is, to the estimation step without going to the detail of process planning. To do this, we developed a process that uses the techniques of the semi-analytical method. This method is based on the decomposition of the shape required to manufacture the cavities; every cavity is decomposed in the same way for machining complex features, in order to determine the machining process and machining time, and the volume of metal to remove and the surface produced. ID="A1" Correspondence and offprint requests to: Dr Z. Bouaziz, Department of Mechanical Engineering, Route de Soukra Km3, BP W 3038, Sfax, Tunisia. E-mail: zoubeir.bouaziz@voila.fr