Please read abstract in the article. | The National Research Foundation of South Africa and the Austrian Science Fund (FWF). | https://pubs.acs.org/journal/aaemcq | 2022-01-19 | hj2021 | Electrical, Electronic and Computer Engineering | Physics

The possibility of Insubosin electrochemical determination on acid-group modified conducting polymers has been evaluated from the theoretical point of view. The correspondent mathematical model has been developed and analyzed by means of linear stability theory and bifurcation analysis. It was shown that the introduction of acid groups into the conducting polymer backbone makes more efficient the analyte immobilization, and that in general the modified conducting polymer is an excellent modifier for insubosin electrochemical determination. A base may be added in order to neutralize the general pH in the system, but not in excess, to avoid the electroanalytical inefficiency of steady-state stability. The possibility of the oscillatory and monotonic instability in this system has also been verified, and it was shown that it is more probable, than in general case, due to the possibility of the hydrogen bonding.

For the first time, the possibility of overoxidized polypyrrole N-oxidation has been investigated from the theoretical point of view. The correspondent mathematical model has been developed and analyzed by means of the linear stability theory and bifurcation analysis. It was shown that the polypyrroleoveroxidation in the presence of peroxide compounds or at a slightly higher potential will yield a N-oxidized form, and its formation will be accompanied by the enhance of the oscillatory and monotonic instability realization probability. This enhance is among the factors, defining the resulting polymer morphology and conductivity.

The theoretical description of prodigiosin pigment electrochemical determination, assisted by novel triazolic derivatives, reinforced by cobalt and nickel oxyhydroxides, has been described. It was noticed that both cobalt and nickel oxyhydroxides may serve as efficient electrode modifiers of prodigiosin electrochemical determination in neutral and lightly alkaline media. The electroanalytical process is diffusion-controlled. The oscillatory and monotonic instabilities in the system are possible, being caused by DEL influences on the chemical and electrochemical stages.

In this work, the possibility for indirect electropolymerization of a monomer, synthetized by an indirect electrosynthesis, has been evaluated. The correspondent mathematical model, based on the reaction mechanism, has been developed and analyzed by means of linear stability theory and bifurcation analysis. It has been shown that in the case of indirect monomer electrosynthesis and electropolymerization, the polymer deposition is far more stable than for direct participation of the monomer in the electrochemical stage. The surface tends to be more developed. Yet the electrochemical oscillations are expected to be less probable than in the case of the direct anodic process.

To our knowledge, they were no detailed numbers published recently on decentralized solar energy in Morocco, even if it starts to gain importance. In the country, demand for photovoltaic solar modules has experienced three major phases: a long period of "relative gloom" (1995-2010) between two phases of rapid growth (1985-1995 and 2010-2018). Today, the inevitable acceleration of solar PV systems connected to the grid has become a reality, despite the absence of any regulation in a legislative framework that has become permissive. It is increasingly urgent to adopt an Application Decree of the net-metering approach to encourage subscribers to declare their solar PV installations to allow verifying that the installed inverters are of sufficient quality and that they do not send unwanted harmonics in the network. At the same time, butane gas, in addition to its use in cooking, is widely preferred for heating domestic water, because of the subsidy. This subsidy is unfair competition to solar water heaters and should be removed because it greatly benefits the richest quintile of the population[i], slightly increasesMorocco's energy dependency by pushing for the waste of so cheap butane gas and surely encourages its use in pumping for agricultural irrigation.[i] Amin BENNOUNA, (in French) "Energy: The poorer we are, the less we are subsidized!", Finance News Weekly No. 722, 05 June (2014) https: ///DOI.ORG/10.13140/RG.2.2.26437.09447

L-Cysteine (L-Cyst) was tested as corrosion inhibitor of tin in Na2CO3 0.1M + NaCl 1M solution. The inhibition action of this inhibitor was studied by using electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) techniques.  Temperature effect on the inhibition efficiency was studied in the range from 298 to 328 K and the values of activation thermodynamic parameters were calculated and explained. Experiment results show that inhibition efficiency increases with increasing of L-Cysteine concentration and decreases slightly with elevation of temperature. L-Cyst is a good inhibitor and inhibition efficiency reach 88% at 10−3M. Analysis of the polarization curves revealed that L-Cyst is considered as a mixed inhibitor. The results from electrochemical measurements and theoretical calculations are in good agreement. The surface morphology of the metal surface was investigated by scanning electron microscopy (SEM).

Abstract:Application of inhibitors to prevent corrosion is a widely accepted form of protection as it is one of the easily available methods. In recent years the usage of natural products as corrosion inhibitors is gaining momentum due to environmental considerations. Extract of zygophyllum qatarense was investigated as corrosion inhibitor of mild steel in 1M HCl using conventional weight loss, electrochemical polarizations and electrochemical impedance spectroscopy. The weight loss results showed that the extract of zygophyllum qatarense is excellent corrosion inhibitor. Electrochemical polarizations data revealed the mixed mode of inhibition. The results of electrochemical impedance spectroscopy shows that the change in the impedance parameters, charge transfer resistance and double layer capacitance, with the change in concentration of the extract is due to the adsorption of active molecules leading to the formation of a protective layer on the surface of mild steel. The effectiveness of inhibition increases with the concentration of inhibitor reached to 88.16% at 3 g / L in 1M HCl medium .

In this work, the possibility of use of vanadium (II) dioxide as an electrode modifier for the cancer marker 4-nitroquinoline-N-oxide has been made. Two parallel mechanisms of assisted electroanalytical determination are possible, due to the presence of peroxide group and nitric group. Both of them provide the electrode reversibility, due to the formation of V(IV) and V(III) compounds. In both of the cases, the electroanalytical process is efficient. On the other hand, the oscillatory behavior probability in this system is correspondent to the electroanalytical process with sequent or parallel electrochemical stages.

Through an eco-friendly solvothermal approach, a reduced graphene oxide (rGO) was successfully fabricated for the convenient removal of diethyl phthalate (DEP) and di(2-ethylhexyl) phthalate (DEHP) from water streams. The morphological and spectroscopical characterization of the prepared rGO was accomplished using SEM, FTIR, EDX and UV-visible spectroscopy. The adsorption properties of rGO was explored using static adsorption experiments. Kinetics, isotherms, thermodynamics and computational studies were performed to evaluate the adsorption process. The results disclosed that the experimental data were compatible with pseudo-second-order kinetics and the Freundlich adsorption isotherm. The kinetic diffusion model revealed that intraparticle diffusion is present but may not be the sole rate-limiting factor.  Thermodynamic analysis indicated that the test adsorbent spontaneously adsorbed DEP and DEHP, driven mainly by entropy change. In the light of theoretical quantum studies, the frontier molecular orbitals, electrostatic surface potential and molecular reactivity parameters for the studied compounds were reported and discussed.