The present study is aiming to explore the effect of 4-Hydroxy-6-methyl-3-(3-quinolin-8-yl-acryloyl)-pyran-2-one (HMQP) and 3-3-(4-Dimethylamino-phenyl)-acryloyl-4-hydroxy-6-methyl-pyran-2-one ...(DMPHP) on mild steel (MS) corrosion in acid solution (1 M HCl). The compound was tested at various concentrations (0.001–1 mM) and four temperatures (298, 308, 318, and 328 K) to determine the optimal concentration and temperature range for the best corrosion inhibiting effect. In evaluating the inhibition efficiency, weight loss measurement, potentiodynamic polarization measurement (PDP), electrochemical impedance spectroscopy, SEM/EDS and theoretical methods were used. The inhibition efficiencies increase with increase in concentration and decreases with temperature. The maximum inhibition efficiency was found 90% and 85.4% at 298 K in the presence of 1 mM of DMPHP and HMQP respectively. The experimental adsorption data obeyed the Langmuir isotherm model. The polarization parameters suggest that DMPHP and HMQP are mixed type inhibitors. The results of the EIS study suggest that these compounds inhibit corrosion by adsorption mechanism. A good correlation between theoretical and experimental results was obtained.
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•Inhibition effect of new pyran derivatives for mild steel corrosion has been studied.•Adsorption of both inhibitors follows a Langmuir isotherm.•SEM and EDS were performed for surface study.•The experimental results were well supported by DFT and Monte Carlo simulation.
► To improve XC 38 steel properties FeCr thermal spray coatings were elaborated using mechanical milled powder. ► Effects of surface roughness and coating thickness were reported. ► The average ...porosity level for the specimens is about 3%. ► The thinner coatings show the best mechanical and electrochemical properties. ► The chromium concentration increases with decrease of coating thickness. ► Using bond layer and voids sealing treatment reduce NaCl penetration.
This paper discusses augmenting a thermal flame spray process with a mechanically milled feedstock to deposit low porosity FeCr coatings onto a steel substrate. A variety of tests were performed to assess the quality of the coatings obtained: microstructural and chemical analyses using X-ray diffraction (XRD) and optical and scanning electron microscopy (SEM) coupled with energy dispersive spectrometry (EDS). The microscopy studies showed that the coatings displayed a lamellar structure with two distinct darker phases and contained unmelted particles; moreover, oxides and micro-cracks were observed at the surface. A lower level of porosity was observed compared to that reported in the literature, and the chromium concentration was found to increase with decreasing coating thickness. The mechanical properties of the coatings were characterized using micro-hardness, adhesion and residual stress tests. The results show a cohesive fracture mode for all samples, whatever the coating thickness. Electrochemical tests were carried out using open circuit potential (OCP), potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) measurements. The best electrochemical properties were observed for coatings in which the voids were sealed with a polymeric substance and those fabricated with a Ni-based bond coating. However, the thinner coatings show higher chromium concentrations, lower porosity, and better mechanical and electrochemical properties than the thicker coatings.
Two novel pyran-2-one derivatives, namely (E)-4-hydroxy-6-methyl-3-(1-(phenylimino) ethyl)-2H-pyran-2-one (Py1) and (E)-3-(1-((2-chlorophenyl)imino)ethyl)-4-hydroxy-6-methyl-2H-pyran-2-one (Py2) were ...evaluated for corrosion inhibition performance on mild steel (MS) in 1M HCl via potentiodynamic polarization (PDP) and Electrochemical Impedance Spectroscopy (EIS). The experimental results show that the inhibition increases with the concentration and can reach a limit value of 90.0% for the inhibitor Py1 at 10−3 M. The polarization curves offer that the pyran-2-one derivatives (Py1 and Py2) are of mixed type. The increase in temperature may have a decrease in the inhibition efficacy of the compounds studied. In addition, the thermodynamic studies show that the inhibitors adsorbed on the surface with chemical bonds (chemisorption) and according to the Langmuir isotherm, the DFT calculations show a good fit to the experimental data.
Research on Air Traffic Flow Management (ATFM) has provided various models. Generally, these models are used for the strategic or even tactical control of flows. In this paper, we will focus on short ...term ATFM models. We first give an approach of macroscopic traffic flow modeling for the short term control of flights and then show how statistical decision techniques will contribute to the conception of such models. Basically, the statistical approach is used to estimate 'dynamically' two exogenous parameters of the traffic flow model developed in this paper: the flow orientation of an air traffic flow through a volume of controlled airspace (sector) and its travel time within the volume.
Two linear discriminant analysis methods designed for categorical variables are used to estimate the decision rules of the previous output's parameters. Comparisons of the simulation results are made through a set of 35 sectors by varying, in each case, the set of descriptor variables.
Speckle reduction is a longstanding topic in synthetic aperture radar (SAR) imaging. Since most current and planned SAR imaging satellites operate in polarimetric, interferometric, or tomographic ...modes, SAR images are multi-channel and speckle reduction techniques must jointly process all channels to recover polarimetric and interferometric information. The distinctive nature of SAR signal (complex-valued, corrupted by multiplicative fluctuations) calls for the development of specialized methods for speckle reduction. Image denoising is a very active topic in image processing with a wide variety of approaches and many denoising algorithms available, almost always designed for additive Gaussian noise suppression. This paper proposes a general scheme, called MuLoG (MUlti-channel LOgarithm with Gaussian denoising), to include such Gaussian denoisers within a multi-channel SAR speckle reduction technique. A new family of speckle reduction algorithms can thus be obtained, benefiting from the ongoing progress in Gaussian denoising, and offering several speckle reduction results often displaying method-specific artifacts that can be dismissed by comparison between results.
Over the last three decades, the scaffold proteins prohibitins-1 and -2 (PHB1/2) have emerged as key signaling proteins regulating a myriad of signaling pathways in health and diseases. Small ...molecules targeting PHBs display promising effects against cancers, osteoporosis, inflammatory, cardiac and neurodegenerative diseases. This review provides an updated overview of the various classes of PHB ligands, with an emphasis on their mechanism of action and therapeutic potential. We also describe how these ligands have been used to explore PHB signaling in different physiological and pathological settings.
The transport sector is responsible for 29 % of global CO2 emissions. This economic sector par excellence is at the center of all governments' concerns. In addition to the scarcity of oil, transport, ...especially urban transport, generates undesirable effects on the environment, public health, energy consumption and space. It is the Maghreb countries, that should bear the consequences more than elsewhere. In Algeria, the intensive use of the private car and the lack of adequate public transport are obstacles to mobility. Several actions are trying to improve transport in cities and new strategies are being put in place to reduce dependence on oil and move towards more sustainable transport.
In pressurized water reactors (PWRs), boron-10 (10B) is added to the primary fluid as boric acid to regulate criticality and power distribution within the core. Indeed, 10B possesses a significant ...neutron absorption cross section of approximately 3845 barns for thermal neutron energy (around 25.3 meV). Thus, under certain circumstances, even a slight variation in boron concentration could lead to criticality issues. This article addresses the problems regarding the accuracy and real-time measurement of Boron Concentration Online Monitoring Systems (BCOMSs) in PWRs. First, the article focuses on presenting BCOMS's key design and safety requirements to ensure a real-time, accurate response during normal operation, operational transients, and accidental events. These requirements help establish a set of performance criteria. Then, we evaluate the influence of different dimensioning parameters on the overall measuring criteria through Monte Carlo simulations using the MCNP6.2 code. Finally, we investigate the physical phenomena involved in the measurement accuracy of BCOMS. This analytical approach not only fosters a deeper comprehension of the underlying phenomena but also facilitates the identification of potential areas for improving measurement accuracy, thereby enhancing the safety of nuclear reactors.
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