Ziziphus mauritiana leaves extracts as corrosion inhibitor for mild steel in H2SO4 and HCl solutions

The inhibition performance of extracts of Ziziphus mauritiana on mild steel corrosion in 0.5 M H2SO4 and 0.5 M HCl was investigated using gravimetric, electrochemical polarization, electrochemical impedance spectroscopy and scanning electron microscopic studies. The gravimetric results indicate that Ziziphus mauritiana leaves extract exhibits good inhibition efficiency in both the acids. Furthermore, the inhibition efficiency decreases with increase in temperature. Polarization measurements showed that the studied inhibitor is mixed type in both acids with significant reduction of cathodic and anodic current densities. Electrochemical impedance spectroscopy measurements revealed that the charge transfer resistance increases with increase in the concentration of Ziziphus mauritiana extracts. Various thermodynamic parameters such as activation energy, activation enthalpy and activation entropy are evaluated and discussed. Adsorption thermodynamic parameters are also computed, and SEM was used to analyze the surface adsorbed film

Corrosion Inhibition on Mild Steel by Phosphonium Salts in 1M HNO3 Aqueous Medium

The corrosion inhibition on mild steel by phosphonium salts in 1 M HNO3 medium has been investigated by weight loss and polarization techniques. The result revealed that these derivatives are excellent inhibitors. Potentiostatic polarization, impedance and electrochemical noise studies showed mixed type inhibitors. Ellipsometer, quantum chemical and FTIR results indicated Phosphonium bromide derivatives exhibit excellent corrosion protective thin layer performance

Corrosion Resistance of AA6063-Type Al-Mg-Si Alloy by Silicon Carbide in Sodium Chloride Solution for Marine Application

The present work focused on corrosion inhibition of AA6063 type Al-Mg-Si alloy in sodium chloride (NaCl) solution with a silicon carbide inhibitor, using the potentiodynamic electrochemical method. The aluminium alloy surface morphology was examined, in the as-received and as-corroded in the un-inhibited state, with scanning electron microscopy equipped with energy dispersive spectroscopy (SEM-EDS). The results obtained via linear polarization indicated a high corrosion potential for the unprotected as-received alloy. Equally, inhibition efficiency as high as 98.82% at 10.0 g/v silicon carbide addition was obtained with increased polarization resistance (Rp), while the current density reduced significantly for inhibited samples compared to the un-inhibited aluminium alloy. The adsorption mechanism of the inhibitor aluminium alloy follows the Langmuir adsorption isotherm. This shows that the corrosion rate of aluminium alloy with silicon carbide in NaCl environment decreased significantly with addition of the inhibito

Study of Temperature Effect on the Corrosion Inhibition of C38 Carbon Steel Using Amino-tris(Methylenephosphonic) Acid in Hydrochloric Acid Solution

Tafel polarization method was used to assess the corrosion inhibitive and adsorption behaviours of amino-tris(methylenephosphonic) acid (ATMP) for C38 carbon steel in 1 M HCl solution in the temperature range from 30 to 60∘C. It was shown that the corrosion inhibition efficiency was found to increase with increase in ATMP concentration but decreased with temperature, which is suggestive of physical adsorption mechanism. The adsorption of the ATMP onto the C38 steel surface was found to follow Langmuir adsorption isotherm model. The corrosion inhibition mechanism was further corroborated by the values of kinetic and thermodynamic parameters obtained from the experimental data

MODELING WHEAT YIELD BY USING PHENOLOGYCAL METRICS DERIVED FROM SENTINEL2 IN ARID AND SEMI-ARID REGIONS- A case study in MOROCCO-

ABSTRACT  Context and background Wheat is one of the oldest cultivated plants in the world and has always been one of the most important staples for millions of people around the world and especially in North Africa, where wheat is the most used crop for typical food industry. Thus, an operational crop production system is needed to help decision makers make early estimates of potential food availability Yield estimation using remote sensing data has been widely studied, but such information is generally scarce in arid and semi-arid regions such as North Africa, where interannual variations in climatic factors, and spatial variability in particular, are major risks to food security.Goal and Objectives: The aim of this study is to develop a model to estimate wheat yield based on phenological metrics derived from SENTINEL-2 NDVI images in order to generalize a spatial model to estimate wheat yields in Morocco's semi-arid conditionsMethodology:The 10 m NDVI time series was integrated into TIMESAT software to extract wheat phenology-related metrics during the 2018-2019 agricultural season, the period in which ground truth data was collected.  Through the multiple stepwise regression method, all phenological metrics were used to predict wheat yield. Moreover, the accuracy and stability of produced models were evaluated using a K-fold cross-validation (K-fold CV) method.Results:The results of the obtained models indicated a good linear correlation between predicted yield and field observations (R2 = 0.75 and RMSE of 7.08q/ha). The obtained method could be a good tool for decision makers to orient their actions under different climatic conditions

trans-Diaqua­bis­[2,5-bis­(pyridin-2-yl)-1,3,4-thia­diazole]cobalt(II) bis­(tetra­fluoridoborate)

The bidentate 1,3,4-thia­diazole ligand substituted by two 2-pyridyl rings (denoted L) has been found to produce the new monomeric title complex, [Co(C12H8N4S)2(H2O)2](BF4)2. The thia­diazole and pyridyl rings surrounding the Co atom are almost coplanar [dihedral angle = 4.35 (7)°]. The mean plane defined by these heterocyclic moieties makes a dihedral angle of 18.72 (6)° with the non-coordinated pyridyl ring. The Co2+ cation, located at a crystallographic center of symmetry, is bonded to two ligands and two water mol­ecules in a trans configuration in an octa­hedral environment. The tetra­fluorido­­borate ions can be regarded as free anions in the crystal lattice. Nevertheless, they are involved in an infinite two-dimensional network along the [010] and [101] directions of O—H⋯F hydrogen bonds

Recours aux satellites pour appuyer le management de l’eau d’irrigation: Estimation des besoins en eau des agrumes par télédétection dans la Plaine de Triffa-Berkane (Maroc)

Les agrumes représentent la première culture irriguée dans la plaine de Trifa (Berkane, Maroc) avec une superficie en extension continue. Ceci accentue les pressions sur les ressources en eau déjà limitées dans la région. De ce fait, une gouvernance efficace et rationnelle de l’eau agricole s’impose. Dans ce travail, nous proposons une approche basée sur les observations satellitaires pour appuyer la gestion de l’eau d’irrigation consommée par les surfaces agrumicoles. Cette approche est scindée en deux étapes : des cartes de coefficient cultural d’agrumes ont été d’abord établies à partir d’une cartographie d’agrumes stratifiés selon l’âge, dérivée à partir des images satellitaires Sentinel optique et radar. Ensuite, une implémentation validée du modèle de Hargreaves a permis l’estimation de l’évapotranspiration potentielle à partir des images thermiques du capteur TIRS du Landsat 8. Comparé au modèle de référence de Penman-Montheith, une erreur (RMSE) inférieure à 0.5mm/jour est enregistrée. Finalement, le croisement des cartes du coefficient cultural et de l’évapotranspiration potentielle a permis de spatialiser l’évapotranspiration maximale des agrumes à l’échelle du pixel de la taille d’un hectare. Ces informations pourraient être intelligemment converties en services de pilotage assisté de l’irrigation pour une meilleure productivité de l’eau agricole

Punica granatum leave extract as green corrosion inhibitor for mild steel in Hydrochloric acid

Leave of Punica granatum extract (LPGE) as green inhibitor for the corrosion of mild steel in 1M HCl solution was studied using weight-loss and potentiodynamic polarization measurements. The results obtained revealed that LPGE has fairly good inhibiting properties for mild steel corrosion in 1M HCl solution, with efficiency of around 94 % at a concentration of 1 g/l. The inhibition was of a mixed anodic–cathodic nature. The film which is formed over the metal surface was analysed by FT-IR spectroscopy. Further examination using X-ray diffraction confirms the role of LPGE as an effective corrosion inhibitor for mild steel in acid media

DNA from Plant leaf Extracts: A Review for Emerging and Promising Novel Green Corrosion Inhibitors.

With growing global awareness and concern for environmental protection through the use of less hazardous and environmentally-friendly extracts of plant origin, there has been a plethora of green corrosion inhibitors research with far reaching contributions to the science of corrosion prevention and control. Attention has increasingly turned towards green corrosion inhibitors, compounds of natural origin with anti-oxidant activity towards metals and their alloys. Green inhibitors have been investigated for their corrosion and adsorption properties with good results. The findings from these research works provide evidence of the adsorption behavior of green inhibitors which was confirmed by the adsorption isotherms that were proposed. Adsorption is the first step of any surface reaction and since corrosion is a surface phenomenon the effectiveness of green corrosion inhibitors is related to their ability to adsorb on metal surfaces. This review proposes the potential of plant dna as an emerging and promising novel inhibitor for mild steel. It begins with a list of plants that have been used in studies to determine corrosion inhibition properties and moves on to establish the adsorption behavior of bio macromolecules; protein, polysaccharides (chitosan) and dna. It reviews studies and investigation of dna interaction and adsorption on inorganic surfaces before focusing on the use of salmon (fish) sperm dna and calf thymus gland dna as green corrosion inhibitors for mild steel. It concludes that plant dna is a promising candidate for green corrosion inhibitor given the similarity between the plant and animal dna structure and function, and the fact that the use of plant is more environmentally sustainable than animal-based produc

Inhibitive action of gramine towards corrosion of mild steel in deaerated 1.0 M hydrochloric acid solutions

The effect of addition of gramine on mild steel dissolution in deaerated 1.0 M hydrochloric acid was studied through potentiodynamic polarisation curves, electrochemical impedance spectroscopy and gravimetric measurements in the temperature range from 25 °C to 55 °C. Gramine was found to shift the corrosion potentials towards less noble values and decrease both dissolution of mild steel and hydrogen evolution reaction. Gramine did not affect the corrosion reaction mechanism (blocking effect). Results obtained from the several measurement techniques were in good agreement and revealed good inhibition efficiencies in the concentration range (0.75 mM ÷ 7.5 mM) particularly at higher concentrations