Applied Chemical Engineering (Transferred)

Abstract Olanzapine (OLP), chemically known as 2-Methyl-10-(4-methyl-piperazin-1-yl)-4H-3-thia-4, 9-diaza-benzo[f]azulene, is an atypical antipsychotic drug. It is used for the treatment of schizophrenia and bipolar disorder. A new simple and selective membrane based potentiometric sensor was developed for potentiometric determination of olanzapine. The membrane was constructed using an ion-pair of OLP and sodium tetraphenyl boron in dioctyl phthalate and PVC. The membrane provides good linear Nernstian response covering relatively wide concentration range of 4 × 10 -6 - 1 × 10 -2 M OLP over pH range of 2.6 - 7.8. The detection limit for the developed sensor was founded as 2.02 × 10 -6 M. The response time of developed sensor is <10 s for the range of determination. The sensor showed good selectivity for OLP in the presence of various cations, anions and other organic molecules. The membrane was successfully applied in direct potentiometric determination of OLP in tablets. The percentage recovery of OLP, ranged from 96.2 to 99.68% with a mean standard deviation <5%, indicates the adoptability of sensor for the direct estimation of OLP in pharmaceuticals. The developed sensor was used to determine OLP in spiked human urine sample and the satisfactory results were obtained.

Abstract We report the in situ synthesis of polyaniline/copper oxide (PANI/CuO) nanocomposites and their characterization as electrocatalyst for non-enzymatic electrochemical glucose detection. Copper oxide (CuO) nanoparticles were prepared by wet chemical precipitation method followed by thermal treatment while the composites of PANI and CuO were synthesized by in situ chemical polymerization of aniline with definite amount of CuO. X-ray diffraction (XRD) results revealed that the composites are predominantly amorphous. The composite formation was confirmed by fourier transform infrared (FTIR) and UV-Vis spectroscopy analysis. The surface morphology was greatly altered with the amount of CuO in composite structure. PANI/CuO nanocomposites were coated on copper substrate to investigate their electrocatalytic activity for glucose sensing. PANI/CuO with 10 wt. % CuO exhibited good response towards electrochemical glucose oxidation.

Abstract This paper subject focuses on modelling of electrochemical processes during a deposition of nanostructured materials on a metallic substrate. Fundamentals of electrocrystallization processes and parameters influenced the final quality of the resulting products are considered. To quantify the evolution of the electrochemical reactor processes with respect to time, an equivalent electric circuit has been established. Two types of periodic supplying currents were taken into consideration: bipolar pulse current and sinusoidal rectified current. Results of performed computer simulations of electrocrystallization processes with the focus on mixed mode oscillations (MMOs) as the dynamical switches between small amplitude oscillations (SAOs) and large amplitude oscillations (LAOs) are presented. The established circuit model can lead to methods for fast treating large quantities of electrocrystallizator data and extracting from them kinetic parameters importantly influenced the structure of the produced materials. 

Abstract The subcooled flow boiling heat transfer characteristics of n-heptane and water is conducted for an upward flow inside the vertical annulus with an inner gap of 30 mm, in different heat fluxes up to 132kW.m -2 , subcooling max.:30C, flow rate: 1.5 to 3.5lit.min -1 under the atmospheric pressure. The measured data indicate that the subcooled flow boiling heat transfer coefficient significantly increases with increasing liquid flow rate and heat flux and slightly decreases with decreasing the subcooling level. Although results demonstrate that subcooling is the most effective operation parameter on onset of nucleate boiling such that with decreasing the subcooling level, the inception heat flux significantly decreases. Besides, recorded results from the visualization of flow show that the mean diameter of the bubbles departing from the heating surface decreases slightly with increasing the flow rate and slightly decreases with decreasing the subcooling level. Meanwhile, comparisons of the present heat transfer data for n-heptane and water in the same annulus and with some existing correlations are investigated. Results of comparisons reveal an excellent agreement between experimental data and those of calculated by Chen Type model and Gungor–Winterton predicting correlation.

Abstract This study focuses on synthesis of nickel oxide catalyst and exploration of its catalytic activities for degradation of methyl orange in aqueous medium. Nickel oxide was prepared sole-gel method using nickel nitrate haxahydrate and citric acid as precursor materials. X-ray diffractometry and scanning electron microscopy were used for characterization of prepared nickel oxide particles. The prepared particles were used as the catalysts for the degradation of Methyl Orange in aqueous medium. The effects of different parameters on degradation of methyl orange were investigated. The degradation of methyl orange followed the Eley-Rideal (E-R) mechanism. The apparent activation energies for degradation of methyl orange determined was found as 36.4 kJ/mol.

Abstract This review article reports the effect of the counter-ions on the ionic surfactant adsorption layer and its relation to the stability of foams and emulsions. The adsorption theory of Davies about the ionic surfactant monolayer was revisited and it is shown how to account for the type of the counter-ions. The experimental validation of this theory on thin liquid films was shown as well, thus explaining the effect of Hofmeister. However, their effect on foams and emulsions is more complex. Furthermore, it is shown how the counter-ions affect in complex way the stability of foams and emulsions via the surfactant adsorption layer in the light of the newest theory. To elucidate the nature of this effect, further investigation is called for.

Abstract Dividing wall column (DWC) offers higher degree of freedom in comparison with the conventional column. Furthermore, the different sections configurations within the column are highly interacting with several recycle loops. Facing with such complex unit operation, describing its behaviour encourages the focal point on the resolution of ideal modelling approaches. Equation oriented (EO) modelling of DWC has been studied by several researchers involving complex algorithm and methodology. In this work, a new approach for modelling of DWC is presented. The modelling methodology involves variables connectivity based on ports and streams that is admissible to equation-oriented flow sheet. To verify the functionality of the proposed method, the modelled DWC is validated with two case studies depicted from experimental literature data to separate alcohol mixture and fatty acid fractionation. The model development was performed in MOSAIC, a web-based modelling tool and run in gPROMS. The model shows good convergence and has less than 10% error when compared to the above mentioned case studies. To furthermore extend the model capability, relative gain array (RGA) analysis was conducted for the fatty acid fractionation to determine the best control configuration in DWC. Result shows that L-S-V and L-S-B configurations are the best control configurations. Our analysis also shows that reflux flowrate, side flowrate and vapor boilup are best to control distillate product, side product and bottom product, respectively.