A Machine Learning Approach to Predicting Coverage in Random Wireless Networks

There is a rich literature on the prediction of coverage in random wireless networks using stochastic geometry. Though valuable, the existing stochastic geometry-based analytical expressions for coverage are only valid for a restricted set of oversimplified network scenarios. Deriving such expressions for more general and more realistic network scenarios has so far been proven intractable. In this work, we adopt a data-driven approach to derive a model that can predict the coverage probability in any random wireless network. We first show that the coverage probability can be accurately approximated by a parametrized sigmoid-like function. Then, by building large simulation-based datasets, the relationship between the wireless network parameters and the parameters of the sigmoid-like function is modeled using a neural network

Antioxidant activity of phenols and flavonoids contents of aqueous extract of Salvia Officinalis origin in the North-East Morocco

Oxidative stress is responsible for several diseases. This phenomen has moved researchers into action in looking for new remedies «antioxidants». The aim of this work was to characterize the phenols and flavonoids compounds of extracts of Salvia Officinalis from  North-East Morocco (TAZA) in terms of antioxidant activity.  The antioxidant activityof this aromatic plant was determined according to the DPPH radical scavenging assay to suggest it as a new potential source of natural antioxidants. The quantification of phenolics and flavonoids compounds of solvent extracts (diethyl ether and ethyl acetate) were determined spectrometrically. Furthermore, The DPPH scavenging activity of extracts increased in the order diethyl ether extract < ethyl acetate extract < ascorbic acid. Finally, we suggest that the phenols and flavonoids compounds of Salvia Officinalis has significant potential as a natural antioxidant

Studies of Catecholase Activities of N-donor Bidentates Ligands derivated from Benzoxazole with Copper (II) Salts

Three functional, N-donorbidentates ligands, L1: 2-(pyridin-2-yl)benzoxazole L2: 2-(quinolin-2-yl)benzoxazole and L3: 2-(4-(trifluoromethyl)pyridin-2-yl)benzoxazole have been examined for their catalytic oxidative activities. The dioxygen complexes of Cu(II) were generated in situ by stirring copper salts and bidentates ligands derivated from benzoxazole. It has been found that these compounds are very efficient to give o-quinone. The nature of the ligands, the counter anion copper (II) salts and solvent have been investigated. These three parameters have an important effect on the oxidation reaction rate

Potential Anticorrosive Effect of Hexamethylenediamine Penta(methylphosphonic) Acid on Carbon Steel in Hydrochloric Acid Solution

The inhibition ability of Hexamethylenediamine penta(methylphosphonic) acid (HTMP) against carbon steel corrosion in 1 M HCl at 30°C was evaluated by weight loss, electrochemical (potentiodynamic and electrochemical impedance spectroscopy, EIS) methods. The experimental results showed that HTMP was a good inhibitor for the steel corrosion in 1 M HCl medium and its inhibition efficiency increased with the inhibitor concentration. Data, obtained from ac impedance measurements, were analyzed to model the corrosion inhibition process through appropriate equivalent circuit models. Adsorption of HTMP on the carbon steel surface followed the Langmuir adsorption isotherm. Surface analysis by (SEM) supported the formation of a protective inhibitor film on the carbon steel surface. Furthermore, the theoretical study was carried out using the density functional theory (DFT) metho

Corrosion Protection of Mild Steel in Hydrochloric Acid at 308 K using Benzimidazole Derivatives: Weight Loss, Adsorption and Quantum Chemical Studies

For the first time, the investigation and characterization of Benzimidazole derivatives, as a potential corrosion inhibitors for mild steel in acidic aqueous solutions has been reported. The inhibition efficiency was calculated based on the data using weight loss, surface studies and basic computational calculations. The values reported in this manuscript were 80% for P1 and 89 for P2. The adsorption of the inhibitors on the mild steel surface was found to obey the Langmuir’s adsorption isotherm. The results obtained from chemical and theoretical techniques are in good agreement with each other

The inhibitive action of Pistacia lentiscus as a potential green corrosion inhibitor for mild steel in acidic medium

The aim of present work is to test the effect of the extract (PLE) and the essential oil (PLO) of Pistacia lentiscus as a potential green corrosion inhibitors for acidic media using weight loss measurements and electrochemical techniques (potentiodynamic polarization curves, and electrochemical impedance spectroscopy) in the presence of different concentrations of PLE & PLO ranging from 0.25 to 2 g/L. The inhibition efficiency was found to increase with increasing inhibitor concentration up to maximum 81.2 % and 92.1 % for PLO and PLE at 2g/L, respectively. Potentiodynamic polarization showed that PLE and PLO act as mixed type inhibitors. Nyquist plots show that the efficiency of inhibition increases with increasing concentration of PL and the increased charge transfer resistance. Adsorption of PLO and PLE on the steel surface followed a Langmuir’s isotherm and the thermodynamic parameters were determined and discussed.

Chemical composition of essential oil and antioxidant and anti-corrosion activity of extract and essential oil of Pennyroyal Mint (Mentha pulegium, MP)

View the growing success of natural products as an alternative to synthetic chemicals. The purpose of this study was to contribute to the valorization of leaves of Mentha pulegium by determining the chemical composition of its essential oil and evaluate in vitro the antioxidant and the anticorrosive activities of its aqueous extract and essential oil. The essential oil revealed 1,8-Cineole (31.9%) followed by piperitone (15.6%), Limonene (14.6%) and β-Pinene (4.8%) as the main constituents. The antioxidant activity of aqueous extract was evaluated by the method of DPPH radical scavenging. The extract and the essential oil of M. pulegium were tested as corrosion inhibitors of mild steel in 0.5 M H2SO4 using weight loss measurements and electrochemical methods. The aqueous extract exhibited a moderate antioxidant activity compared to acid ascorbic and the IC50 value was 36,62 µg/mL. The obtained  results  have showed that the inhibition efficiency increases with increasing  inhibitor  concentration  to  attain  90.3 % at  2 g/L of  MPE and 87.3 %  at 4g.L-1 of MPO at 303 K. Finally, extracts and essential oil of M. pulegium from Mediterranean origin have numerous potential as a substitute to chemical additives for the food industry

The Palm oil from seed of Phoenix dactylifera (Oil of both Deglet Nour and Kentichi) as a natural antioxidants and Environment-Friendly inhibitors on the Corrosion of mild Steel in HCl 1M

The flora of Republic of Algeria comprises a lot of Palm species, including Phoenix dactylifera. In this work, we used the Palm oil from seed of Phoenix dactylifera (Oil of both Deglet Nour and Kentichi). The objective of this study is divided into two parts. Firstly, determine the antioxidant activity of Palm oil from seed of Phoenix dactylifera (Oil of both Deglet Nour and Kentichi) according to the DPPH radical scavenging assay to suggest it as a new potential source of natural antioxidants, secondly, study the effect of inhibiting Palm oil from seed of Phoenix dactylifera (Oil of both Deglet Nour and Kentichi) on corrosion of mild steel in hydrochloric acid by electrochemical methods. Furthermore, The DPPH scavenging activity of Oil of both Deglet Nour and Kentichi increased in the order, Deglet Nour Oil < Kentichi Oil < ascorbic acid. The results of the polarization curves show that the corrosion current density decreases 577.9 μA/cm2 to 58μA/cm2 and to 59.3 μA/cm2 after addition of the inhibitor (oil of Deglet Nour and Kentichi respectively). The charge transfer resistance increases 21.69 ohm.cm2 to 186.5 ohm.cm2 and to 222.8 ohm.cm2 in the electrochemical impedance spectrum after addition of oil of Deglet Nour and Kentichi respectively. The inhibition of the compound effect is attributed to the formation of a film on the surface of the steel.

Imidazo[4,5-b]pyridines as a New Class of Corrosion Inhibitors for Mild Steel: Experimental and DFT Approach

6-Bromo-2-methyl-1H-imidazo[4,5-b]pyridine (P1), was investigated for its adsorption and corrosion inhibition traits for mild steel corrosion in 1.0 M HCl solution. Gravimetric, potentiodynamic polarization and electrochemical impedance spectroscopy methods, were used to test the nature of adsorption and the inhibition effect of P1 on the mild steel in acidic media. It was found that the inhibition efficiency improved with the increase of P1 concentration in the acid solution (1.0 M HCl). The adsorption of P1 favored Langmuir adsorption isotherm. The results of corrosion tests confirmed that P1 could serve as an efficient corrosion inhibitor for the mild steel in 1.0 M HCl solution, yielding a high efficiency and low risk of environmental pollution. The theoretical quantum chemical calculations were in good correlation with the experimental result