New Analytical Method for Maximum Temperature Assessment in an Exothermic Tubular Chemical Reactor

This paper deals with an analytical method to assess the maximum temperature value along a tubular chemical reactor at steady state. This reactor is provided with a jacket in which a counter current cooling liquid flows. The thermal behavior of the chemical reactor is calculated with the McCormack numerical method. Comparison of the exothermic reaction generated flux with the removed flux from the separating wall leads to a two-part reactor subdivision. In the first part, the reactor behaves as an adiabatic reactor followed by a zone in which the flux removed from the wall is not negligible and remains constant. In the second part, the reactor behaves like a simple heat exchanger without internal energy source. Analytical integration of mass and energy balance equations in each subsystem was used to determine the analytical expression of maximum temperature.     

Electrochemical,spectroscopic and molecular docking studies of 4-methyl-5-((phenylimino)methyl)-3H- and 5-(4-fluorophenyl)-3H-1,2-dithiole-3-thione interacting with DNA

Cyclic voltammetry (CV) and UV–Visible spectroscopy (UV–Vis) techniques were used to calculate binding parameters of 4-methyl-5-((phenylimino)methyl)-3H-1,2-dithiole-3-thione (MPDT) and 5-(4-fluorophenyl)-3H-1,2-dithiole-3-thione (FPDT) with DNA. The results obtained from both techniques were confirmed by computational molecular docking using AutoDock molecular docking software. The anodic peak potential shift in CV indicated an intercalative mode of binding. The binding constants (M^?1) of the adducts MPDT-DNA and FPDT-DNA obtained from voltammetric measurements were found to be 8.0?×?10⁴ and 2.4?×?10⁴, respectively, with binding free energy being ?27.99 and ?25.01?KJ?mol^?1, respectively. These results are in good agreement with those obtained from UV–Visible spectroscopic studies. The diffusion coefficients of MPDT and FPDT (2.06?×?10^?10 and 2.42?×?10^?9, respectively) were found to be higher than those of DNA-bound compounds (1.27?×?10^?10 and 1.65?×?10^?9?cm²/s, respectively). The binding free energy of MPDT and FPDT to DNA was also calculated by molecular docking study. The docking study gave excellent approximation with experimental results, shedding light on the sites of binding.     

Effect of nitrogen and carbon sources on Indigo and Congo red decolourization by Aspergillus alliaceus strain 121C

The decolourizing ability of Aspergillus alliaceus 121C was investigated on solid medium. The effects of nitrogen (N), carbon (C) sources and supplements on the decolourization of Indigo and Congo red dyes were studied. It has been shown that both the nature and the quantity of available N- and C-sources exert an influence on growth and decolourization. For the six N-sources (NH(4)Cl, Diammonium Tartrate, urea, malt extract, peptone and yeast extract) tested for Congo red decolourization, 8mM yeast extract provided the higher decolourized zone diameter (80 mm) and colony diameter (80 mm). 12 mM urea provided the higher decolourized zone diameter (76+/-2mm) and colony diameter (80 mm) for Indigo decolourization. For the C-sources tested (glucose, starch, glycerol and lactose), above 12.5mM of glucose and 62.5mM of starch provided the higher decolourized zones diameters of 80 mm and 77+/-3mm for Indigo and Congo red, respectively. When the fungi was grown in liquid medium containing optimum carbon and nitrogen sources supplemented with oak sawdust and wheat bran, more than 98.6% and 98% of colour removal are obtained for Indigo and Congo red dyes, respectively. The detection of ligninolytic enzymes proved that laccase and lignine-peroxidase (LiP) are the two enzymes responsible of the decolourization of the two dyes.     

Electrosynthesis of adherent poly(3-amino-1,2,4-triazole) films on brass prepared in nonaqueous solvents

The kinetics of the electropolymerization of 3-amino-1,2,4-triazole on a brass substrate in alkaline solution containing methanol was investigated using cyclic polarization, chronoamperometry, electrochemical impedance techniques and scanning electronic microscopy. The polymeric film was prepared by successive cycles of potential of a 60Cu–Zn electrode between 0 and 1.6 V. During the second cycle, the oxidation peak of the monomer disappears indicating the formation of the insulating film. We have also shown that the monomer oxidation reaction is essentially irreversible and controlled by a diffusion process. The protective effect of the film formed on brass has been studied in a 3%NaCl and 3%NaCl + S^2? solution. The results showed important inhibition efficiency, about 96% for 4 h of testing time.     

From use case maps to executable test procedures: a scenario-based approach

Software and Systems Modeling - Testing embedded systems software has become a costly activity as these systems become more complex to fulfill rising needs. Testing processes should be both...     

Design of T-shaped tube hydroforming using finite element and artificial neural network modeling

Journal of Mechanical Science and Technology - Tube hydroforming (THF) is a frequently used manufacturing method in the industry, especially on automotive and aircraft industries. Compared with...     

Preparation of Nano-TiO2/Diatomite Composites by Non-hydrolytic Sol–Gel Process and its Application in Photocatalytic Degradation of Crystal Violet

Silicon - The dispersion of anatase TiO2 on diatomic material was a prospective route to avoid agglomerates of these particles. In this work, the TiO2/diatomite composites were prepared using a...     

Effect of the Formulation of Sodium Activation Solutions on the Setting Time of Metakaolin Based Geopolymers

Geopolymer materials today represent innovative products,used frequently as a substitute for cementitious traditional materials.They are obtained by the action ...     

Effect of additives on nickel-phosphorus deposition obtained by electroless plating: Characterization and corrosion resistance in 3%(mass) sodium chloride medium

Nichel-phosphorus (Ni-P) coatings are deposited on mild steel by using an electroless plating process. The effect of three calix[4]arene derivatives, namely tetra methyl ester-P-tertbutyl calix[4]arene (Calix1), tetra acid-P-tert-butyl calix[4]arene (Calix2) and tetra methyl P-tert-butyl-thicalix[4]arene ester (Calix3) on the deposition rate, the deposit composition, and the morphological surface was investigated and the study of growth mechanisms has delivered useful information about the surface properties of deposit. It is found that these additives modify the deposition rate and the nickel crystallization process. In fact, the Calix1 and Calix3 act as an accelerator, while Calix2 acts as an inhibitor for the nickel electroless. Furthermore, it is shown that the chemical bath is more stable with calix[4]arene derivatives addition and the obtained deposits are compact and adherent. It is observed also that the nickel content increases with additives. On the other hand, the X-ray diffraction showed that the orientation peaks are intensified at {1 1 1} in the presence of Calix2, confirming obtained results of EDAX spectrum. The cyclic voltammetry revealed that the tested additives strongly influence the cathodic process and slightly affect the hypophosphite oxidation. Finally, it is found that these compounds improve the anticorrosion efficiency of Ni-P coating on the mild steel substrate in 3% (mass) NaCl, where its polarization resistance increases with Calix2 and Calix3 addition.