Potentiometric Determination of Alkyl Dimethyl Hydroxyethyl Ammonium Surfactant by a New Chemically Modified Carbon Past Electrode

This paper introduces the development a new chemically modified carbon paste electrode (CMCPE) for the determination of a cationic surfactant. The paste is based on alkyl dimethyl hydroxyethyl ammonium chloride (ADHACl) with phosphomolybdic acid as an ion‐exchanger (ADHA‐PM). The electrode exhibits a Nernstian slope of 59.1 ± 0.5 mV/decade for ADHA ions in the concentration range 1.0 × 10^?6–1.0 × 10^?3 M with the limit of detection of 8.2 × 10^?7 M. The proposed electrode has a fast and stable response time of 5–8 s, a good reproducibility and it can be used in the pH range of 2.2–9.0. Selectivity coefficients, determined by a matched potential method and separate solution method, showed high selectivity for ADHA over a large number of inorganic cations and organic cations. These characteristics of the electrode enable it to be used successfully for determination of ADHA in shampoo and liquid detergents solutions by standard addition and the calibration curve methods. In addition, the modified electrode was applied as an indicator electrode in potentiometric titration and successfully used to determine ADHA in water samples with satisfactory results.     

Inferential sensor – Based adaptive principal components analysis for mechanical properties prediction and evaluation

This paper is concerned with a method for on-line quality prediction and evaluation of mechanical properties in metal testing. This method uses an Adaptive Principal Component Analysis (APCA) as a multi predictor of different sub-models defining the mechanical properties such as constraints limits and elongation. The PCA technique, characterized by its multivariate component, is strongly recommended to model a multi-input-multi-output system. The complex system is generally known as a non-linear and unsteady state process. The PCA method is a linear projection. To adapt it and to improve the prediction accuracy, a variant of this method is considered based on iteratively using a specific algorithm. This kind of approaches is applied for constructing an inferential model, which allows a reliable and accurate predictor. Simulation results, based on the measured and computed data using the above-cited method, show that the proposed approach is easily implementable and give an accurate prediction.     

High‐Mechanical‐Strength Flame‐Retardant Nanocomposites Based on Novel Al(III)‐ and Zr(IV)‐Melamine Phosphates and Sulfates

Nanoparticles based on Al(III) and Zr(IV) melamine phosphate and sulfate, respectively, are prepared. Cone calorimeter measurements reveal that compared to an unfilled polyacrylate matrix the polyacrylate‐based nanocomposites containing the novel nanoparticles display significantly improved flame‐retardant properties as evidenced by the corresponding values for the peak heat release rate, the time‐to‐ignition, the values for the peak rate of heat release, the total heat evolved, the time to the CO peak and the CO yield. Concomitantly, the mechanical properties of the acrylate‐based composite coatings, i.e., the Martens and surface hardness, can also be significantly improved.

     

Effects of hydrogen addition and Carbone dioxide dilution on the velocity field in non reacting and reacting flows

The evolution of anti-pollution standards and the optimization of combustion efficiency push the development of new fuels with high energy efficiency. It is necessary to develop new alternative fuel to improve the efficiency of conventional systems, reduce emissions (NO_x, SO_x, soot particles) and recover for its materials. A new fuel called bio-hythane, a mixture of natural gas up to 20% hydrogen and up to 50% Carbone dioxide, from the recovery of the waste from households and agriculture, via suitable digesters provides a source of renewable energy and usable, is a very interesting solution to improve emission standards and optimization of the combustion chambers.     

Intervention in biological phenomena modeled by S-systems

Recent years have witnessed extensive research activity in modeling biological phenomena as well as in developing intervention strategies for such phenomena. S-systems, which offer a good compromise between accuracy and mathematical flexibility, are a promising framework for modeling the dynamical behavior of biological phenomena. In this paper, two different intervention strategies, namely direct and indirect, are proposed for the S-system model. In the indirect approach, the prespecified desired values for the target variables are used to compute the reference values for the control inputs, and two control algorithms, namely simple sampled-data control and model predictive control (MPC), are developed for transferring the control variables from their initial values to the computed reference ones. In the direct approach, a MPC algorithm is developed that directly guides the target variables to their desired values. The proposed intervention strategies are applied to the glycolytic-glycogenolytic pathway and the simulation results presented demonstrate the effectiveness of the proposed schemes.     

An Autonomous Fault-Awareness model adapted for upgrade performance in clusters of homogeneous wireless sensor networks

Wireless Networks - Wireless sensor networks (WSNs) have conquered comprehensive survey progressions in the regular control and management fields. Although WSN allows the spatial monitoring of...     

Determination of benzalkonium chloride preservative in pharmaceutical formulation of eye and ear drops using new potentiometric sensors

A novel approach for determination of low concentrations of the preservative, benzalkonium chloride (BCCl), in pharmaceutical formulation constitutes is presented. New chemically modified carbon paste electrodes (CMCPEs) are developed. The first is based on an ion-association of BCCl with phosphomolybdic acid (PMA) as the ion-exchanger (BC–PM) dissolved in the mixed plasticizers dibutyl phthalate (DBP) and dioctyl sebacate (DOS) encoded sensor A. In the other electrode, encoded sensor B, the plasticizers DBP and dioctyl phthalate (DOP) are more suitable solvent mediators for the paste. These electrodes exhibit a Nernstian slope of 58.2 ± 0.6 and 62.3 ± 0.7 mV/decade in concentration range 1.3 × 10^? 7–1.7 × 10^? 4 M and 2.5 × 10^? 7–1.7 × 10^? 4 M with the limit of detection of 1.0 × 10^? 7 M and 1.6 × 10^? 7 for sensors A and B, respectively. The sensors have short and stable response time 5–8 s, good reproducibility and can be used in pH range of 5.7–8.6. The present electrodes show good discrimination of BCCl from several inorganic, organic ions and some common drug excipients. These characteristics of the electrodes make them useful in successful determination of BCCl in its pharmaceutical preparations (eye and ear drops) and aqueous solutions. The results obtained were satisfactory with excellent percentage recovery comparable and sometimes better than those obtained by other routine methods for the assay.     

Equations of Motion of Planar Serial Chains of Rigid Bodies

In the present study, the equations of motion of planar serialchains that consist of a system of rigid bodies with all commontypes of kinematic joints are presented. The system of rigid bodiesis replaced by a dynamically equivalent constrained system ofparticles. The concepts of linear and angular momentums are used togenerate the equations of motion for the resulting equivalentconstrained system of particles without either introducing anyrotational coordinates or distributing the external forces and forcecouples over the particles. The method can be applied for open orclosed chains. An example of a closed chain is chosen to demonstratethe generality and simplicity of the proposed method.     

On the effectiveness of porosity on unsteady flow between parallel plates of a viscoelastic fluid under constant pressure gradient with heat transfer

The unsteady flow in a porous medium of an incompressible non-Newtonian viscoelastic fluid between two parallel horizontal non-conducting porous plates is studied with heat transfer. A sudden uniform and constant pressure gradient and uniform suction and injection through the surface of the plates are applied. The two plates are kept at different but constant temperatures, while the Joule and viscous dissipations are taken into consideration. Numerical solutions for the governing momentum and energy equations are obtained using finite difference approximations. The effect of the porosity of the medium, the parameter describing the non-Newtonian behavior, and the velocity of suction and injection on both the velocity and temperature distributions is examined.