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 amitrol pesticide electrochemical determination, assisted by cobalt (III) oxyhydroxide has been evaluated. The correspondent mathematical model has been developed and analyzed by means of linear stability theory and bifurcation analysis. It was shown that the oxyhydroxide may be applied as an efficient electrode modifier in the detection of Amitrol as sodium salt in neutral and lightly alkaline media. The electrochemical response has to be clear and easy to interpret. The possibility of the oscillatory and monotonic instabilities has also been verified.

The theoretical description for 4-4´-dihydroxyazobenzene CoO(OH) – assisted electrochemical determination in mushroom pulp, food and biological liquids has been described. In this system, a squaraine dye is used as a Cobalt(III)oxyhydroxide stabilizer and electron transfer mediator. It is shown that, contrarily to the great part of the systems with cobalt (III) oxyhydroxide, this system will behave in a more stable manner, providing an efficient diffusion-controlled process. On the other hand, the oscillatory and monotonic instabilities, although possible, are caused by the double electric layer influences of either chemical or electrochemical stage.

In December 2019, a pneumonia outbreak of unknown etiology has been erupted in the city of Wuhan (China). The new coronavirus firstly known as 2019-nCoV, then officially identified as sars-cov-2 still exponentially spreading and growing in all over the world. The virus reaches the lungs through the receptors of angiotensin-converting enzyme 2 (ACE2). Among all proposed treatment related to infections of coronavirus, the flavonoid derivatives are suggested to be alternative therapies in the fight against Covid-19. This research aims to determine the components of natural origin can prevent infection with coronavirus. The molecular docking is applied to explore the binding mode between 54 flavonoids and chloroquine with the (ACE2) receptor. five among 54 components have showed high total score. Afterward, the binding mode of the five selected molecules were further analyzed and detailed. Moreover, these five inhibitors were tested for their ADMET properties and drug-like properties. These findings could be useful for searching new inhibitors against the coronavirus.

The main objective was to assess the level of air pollution, in accordance with World Health Organization (WHO). This work focused on the impact of atmospheric emissions, such as particulate matter (PM10) generated by industrial activities of petroleum refining, liquefied natural gas processing and petrochemicals, on ambient air quality in the region of Arzew (Algeria) during 2019. The study found that PM10 level greatly exceeded (51.18 μg/m3) the annual average (20 μg/m3) recommended by the WHO During the sampling period. This study also demonstrated that PM10 levels are dependent on industrial emission rates and weather seasons, peaking in the summer mainly due to stable weather conditions.

Theoretical developments have made it possible to make quantum physics applied to chemistry an essential tool associated with experimental chemistry. Two avenues have emerged for this development: one addresses the problems by describing systems by a wave function; the other does so by its electron density. In this work, we studied the quantum method of the density functional theory (DFT) B3LYP / 6-311G (d, p) to determine the various quantum chemical descriptors and the optimization of the different molecules: p-bromophenol, p-fluorophenol and p-chlorophenol. The study of the global reactivity of molecules is based on the calculation of global indices deduced from electronic properties, such as ionization potential (I), Electronic affinity (A), chemical hardness (η)., Electronegativity x. and Overall softness (σ), Maximum charge transfer (ΔNmax), Overall electrophilicity (ω). Besides, we worked on nonlinear optical descriptors (NLO) such as the dipole moment (μ), the polarizability (α), the first hyperpolarizability (β), and the second hyperpolarizability (γ). To check the stability of the molecules we determined the 3D maps of the HOMO and LUMO orbitals, the Mulliken charges of each molecule, the electrostatic potential, the lengths, and the bond angles of the molecules of p-bromophenol, p-fluorophenol, and p-chlorophenol.

Covid-19 caught all of us off guard and its devastating impact of such a pandemic is being felt in all the sectors of the society. To prevent the spread of this highly life-threatening disease, the governments on all levels had imposed, inter alia, lockdown measures.  As a result of this, the schools, colleges, offices were shut and the air and road travel was very restricted in the country. The movement of the people was restricted and very few vehicles were on the road. Though the lockdown brought many difficulties for the people, but is a blessing in disguise. Due to people were remaining in homes and transportation was being minimal, there has been a significant improvement in the quality of environment and ecology. The urban environmental parameters like traffic noise emissions and noise indices, concentration of air pollutant was decreased considerably.The present work analyzes the environmental impact of lockdown in Berhampur city. The study reveals that the noise levels and noise pollution indices was decreased drastically. Also, the air pollution level was decreased considerably.

This study examined the theoretical impact and modeling of photocatalyst, MoS2, on organic pollutants and wastewater treatment. The electronic band structures, density of state (total and partial), optical properties, and photocatalytic operation under UV or visible light were investigated by using the first principle method for MoS2 and W doped by 5%. In order to calculate band gap, generalized gradient approximation (GGA) based on Perdew- Burke- Ernzerhof (PBE) was used. The band gap for MoS2 was recorded at 1.78 eV which is close to the experimental value of 1.72-1.8 eV. To recognize the character of photocatalyst activities, the optical properties were investigated and calculated. Moreover, the total density of state and partial density of state were estimated for exploring the nature of 5s, 4d for Mo, and 3p for S atom for MoS2 material. Concurrently, optical properties, absorption, reflection, refractive index, conductivity, dielectric function, and loss function were calculated. Having doped W with MoS2, the band gap, optical properties had changed and improved the photocatalytic effect to the hybridization of W. From the value of band gap and optical properties, it is clear that Mo0.95W0.05S2 can provide better UV or visible light rather than MoS2.

The present paper summarizes a numerical study investigating the behavior of a phase change material PCM filling up a cylindrical container. The PCM is located between two tubes, the inner tube cares for the Heat Transfer Fluid HTF and it is proposed to produce a heat flux. The investigation focuses mainly on comparing the effect of changing the inner tube position, i.e., up, center, and down, in the melting process. Results showed that moving the inner tube downward leads to a decreased melting time and the rate of the thermal energy storage becomes better.

The corrosion inhibition of C38 steel in 1M HCl by isomeric derivatives of 4-methylthiazol-2(3H)-thione (TO1, TO4 and TO6) has been investigated using weight loss and electrochemical measurements supplementing with surface characterization study using X-ray photoelectron spectroscopy (XPS). Experimental observations were found to be in agreement with density functional theory (DFT) calculations. The inhibition efficiency increases with increase in the three compounds concentration and showed maximum inhibition efficiency of 98.33%, 96.91% and 94.44% for TO1, TO4 and TO6 at 2.10-4M in HCl 1M, respectively, at concentration of 2×10-4 M at 30°C. Polarization curves reveal that the three inhibitors act as mixed type inhibitor with tendency to anodic branch. Impedance parameters (charge transfer resistance, Rt, and double-layer capacitance, Cdl) indicate that the investigated compounds form stable protective films on the steel surface. Adsorption of TO1, TO4 and TO6 on the C38 steel surface is found to obey the Langmuir adsorption isotherm. The X-ray photoelectron spectroscopy (XPS) of the carbon steel treated with the three compounds indicated that these later are chemically adsorbed on the steel surface.  Good correlations were obtained between the anti-corrosion performance of these donor-acceptor compounds and their molecular properties.