Polarization Studies Research Articles

Ajuga orientalis L. Extract as a Green Corrosion Inhibitor of Aluminum in an Acidic Solution: An Experimental and DFT Study

The inhibitory effect of A. orientalis L. extract (AO) on aluminum corrosion in a 1.0 M HCl solution was investigated utilizing weight loss, electrochemical polarization, electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM). The results show that AO is a potent inhibitor in an acidic environment, and that the inhibition potency increases with concentration. Temperature investigations showed that, in an acidic medium, the efficiency decreased, increased, and then decreased as the temperature rose. Adsorption isotherms from Freundlich, Temkin, El Awady, and Redlich–Peterson (R-P) approximated the inhibitor’s adsorption properties. For the inhibitory behavior, a physical and chemical adsorption mechanism is proposed. The adsorption process’s thermodynamic parameters (Ea, ΔH*, and ΔS*) were determined and explained. The inhibitor, AO, was identified as a mixed-type (anodic and cathodic) inhibitor based on polarization studies. According to the SEM findings, the inhibitor partially covers the metal surface, providing it with a respectable level of protection. The weight loss, electrochemical polarization, EIS, scanning electron microscopy (SEM), and quantum chemical calculations show a strong agreement, indicating that the AO extract is a highly effective inhibitor of aluminum in an acidic solution.

Polarization study of the P-wave charmonium radiative decay into a light vector meson at e+e- collider experiment

Abstract In this work, a formalism is presented for the helicity amplitude analysis of the decays ψ(2S) →γ1χcJ, χcJ→γ2V (V=ρ0, Φ, ω) (the subscript 1,2 is used to distinguish the two radiative photons), and the polarization expressions of the P-wave charmonia χcJ and the vector mesons ρ0, Φ, ω for experimental measurements at Electron-Positron Collider. In addition, we derive the formulae of the angular distributions of the χc1,2→γV to extract the degree of transverse polarization PT of e+e- pairs with symmetric beam energy as well as the ratios of two helicity amplitudes x (in χc1 decays) and x, y (in χc2 decays) representing the relative magnitudes of transverse to longitudinal polarization amplitude, and validate it by performing the Monte Carlo simulation. Finally, the statistical sensitivity of PT, x and y are estimated based on the large ψ(2S) data samples collected at the current and proposed future e+e- collider experiment.Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must main tain attribution to the author(s) and the title of the work, journal citation and DOI. Article funded by SCOAP3 and published under licence by Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Sciences and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd

Functionalized polyaniline nanofibrils on lamellar structured zirconium for effective bone mineralization

The surface physiology of certain implant material has the ability to promote implant–cell signalling process through which a stable environment is formed. The formation of this favourable environment hastens the process of biomineralization and regeneration. In this context, Zirconium (Zr) when treated with alkali undergoes a surface modification which results in the development of a lamellar structured Zirconium (ATZ). Further, encapsulation of polyaniline (PAni) on ATZ was achieved through the electropolymerization technique which results in an effective and homogeneous electrodeposition of PAni nanofibrils on ATZ surface. A high resolution scanning electron microscope analysis (HR-SEM), phase analysis and functional group analysis were carried out confirming the semi-crystalline PAni nanofibrils braided on the ATZ surface. Potentiodynamic polarization studies of the coated sample exhibited higher Ecorr (−0.060 V) and lower icorr (0.007 µA/cm2) values signifying its better corrosion resistance behaviour in higher potentials coupled with lower electrochemical activity in the SBF medium. The porosity of PAni/ATZ nanofibril was 0.007 % and it provides an effective platform for implant-tissue attachment. The In-vitro biomineralization studies proved the bioactivity of PAni/ATZ which forms well-matured HAp spherules over the surface. Further, hemocompatibility studies of PAni/ATZ expressed a hemolytic rate of ∼0.39 % which denotes it’s biocompatible and non-hemolytic behaviour with the blood cells. Further, the coated sample on gram-positive and gram-negative bacteria causes demise of bacterial cell wall and exhibits higher inhibition percentage. In addition, a standard MTT assay of PAni/ATZ provides an effective support in maintaining cell viability and aids in proliferation of MG-63 cells. Thus, the results demonstrate that the nanoscale surface architecture of PAni/ATZ could serve as a potential and conducive environment for bone-implant interaction on the implant material for better osseointegration.

Thermal fluctuations on the corrosion behaviour of 17-4PH stainless steel alloys fabricated via material extrusion additive manufacturing technique

Herein, the influence of fluctuating thermal conditions on the corrosion behaviour of 17-4PH stainless steel alloys manufactured via fused filament fabrication is reported. The printed samples were sintered and then exposed to different temperature-fluctuating conditions to simulate the application environment of such alloys. The first set of samples (A) was studied as-sintered, the second set of samples (B) was aged at 480°C for 3 h followed by quenching in water, the third set (C) was exposed to conditions of B followed by aging at 360°C for 3 h and quenching in water and the final set of samples (D) was exposed to conditions of C followed by aging at 200°C for 3 h, quenching in water, aging at 400°C for 3 h, and finally quenching in water. The surface roughness evolved with the temperature conditions. The optical microscopy revealed that sample B had a fine and homogenous distribution of precipitates. Sample B had the highest microhardness values followed by C, D, and A in that order. XRD analysis revealed the presence of retained FCC austenitic phases within the microstructure whose peaks became stronger with the increased thermal fluctuations. The potentiodynamic polarisation studies revealed a distinct linear Tafel region on the cathodic region and a dual-slope inflection point on the anodic region of the polarisation curves. Sample D exhibited the highest corrosion rate whereas sample B revealed the lowest. As such, exposing fused filament fabricated 17-4 PH SS to fluctuating temperature conditions leads to degradation of mechanical strength and corrosion resistance.

ASPECTS OF SURFACE ENAMEL MINERALIZATION IN PERMANENT TEETH OF CHILDREN FROM DIFFERENT AGE GROUPS

The purpose of our study was the examination of external surface enamel mineralization in permanent teeth of children from different age groups. We examined sections of 50 extracted for orthodontic indications premolars in patients from different age groups. A study of 16 teeth was conducted in 11-13 years old children, 8 teeth were investigated in each group of 13-15 years old, as well as 9 teeth in 15-16-year-old patients. All patients were appointed with remineralization therapy during the first six months after tooth eruption fallowed by application of “Tooth Mousse” ones a day for 2 weeks every six months with appropriate monitoring. The comparison group, on the other hand, consisted from extracted teeth taken from children who were not subjected to any preventive remineralization measures. The distribution by age and the studied material was identical to the main group. Segmentation of the teeth was carried out after the tooth extraction with separation of the crown structure and further polishing of the crown using polishing brushes without pastes. Sections 0.3-0.5 mm thick were formed with a diamond disc. The enamel samples were cleaned and degreased and then examined in a polarizing microscope (Optika B-150POL-B 40x-640x Bino) at a magnification in 500 times. The description of the enamel microscopic surface was carried out according to the following parameters: surface heterogeneity, surface opaqueness/shininess, surface roughness/smoothness. The surface homogeneity was assessed by calculating the ratio of identified surface areas that visually differed from the overall enamel texture, which was characteristic of the predominant investigated surface enamel. There were criteria for evaluating the enamel surface heterogeneity according to the research data in a polarizing microscope : the presence of numerous well-defined cracks, the visualization and number of areas from which the enamel prisms extend, the presence and number of enamel surface irregularities confirmed by a change in the direction of the light beam, the percentage of surface homogeneity, which was calculated as the ratio of the area of ​​the visually homogeneous enamel surface to the area with ​​any microscopically detected changes. To assess the opacity of the enamel surface by the microscopic polarization study, the criteria of visual assessment of shiny and dark areas of interest were used. The study suggested that microscopic changes are characterized by a decrease of total number in enamel surface irregularities and an increase of its glossiness and smoothness at the approach of structural compositional stabilization at 15-16 years. The analysis also revealed that there were marked microscopic differences observed in enamel of 15-16 years old after remineralization with the "Tooth Mousse" gel and a comparison group (without remineralization therapy).The difference between them is reliable (p<0.01) according to the indicators of the relative average level of surface heterogeneity, and also statistically different from similar indicators that were registered in the age groups 11-13 and 13-15 years old (p<0.01). The gained results can be considered as the expediency grounds for implementation of dental caries prevention at the early stages of secondary mineralization (immediately after eruption) and throughout the entire period of its intensive phase, which will further contribute to the stabilization of the caries-resistant enamel.

Corrosion behaviour of the magnesium-cerium binary alloy designed for degradable medical implants

ABSTRACT Magnesium (Mg) alloys containing rare earths (RE) gained special attention as promising candidates for degradable implant applications. Cerium (Ce) is one of the RE elements which can be tolerated by the human physiological system when used as an alloying element in Mg alloys. In this current research work, Mg-Ce binary alloys (0%, 0.5%, 1%, 1.5%, and 2% Ce by weight) were prepared by the stir-casting method. The developed alloys were characterised, and corrosion performance was assessed by immersion experiments in normal saline solution and by electrochemical experiments. The degradation rate of the developed alloys was measured as decreased with the increased Ce content up to 1.5%. From the polarisation studies, lower corrosion current density values 3.5 × 10−5 A/cm2 and 4.1 × 10−5 A/cm2 were observed for Mg-1.5%Ce and Mg-2%Ce alloys, respectively compared with the other samples. The surface morphologies after removing the corrosion products revealed more degraded regions for Mg and alloys with lower Ce content (0.5% and 1%) compared with 1.5% and 2% Ce. From the results, it is concluded that developing an Mg-Ce alloy with an optimum fraction of Ce (1.5%) is promising to produce degradable Mg-based medical implants with controlled degradation.

Ice Sheet Mass Changes over Antarctica Based on GRACE Data

Assessing changes of the mass balance in the Antarctic ice sheet in the context of global warming is a key focus in polar study. This study analyzed the spatiotemporal variation in the Antarctic ice sheet’s mass balance, both as a whole and by individual basins, from 2003 to 2016 and from 2018 to 2022 using GRACE RL06 data published by the Center for Space Research (CSR) and ERA-5 meteorological data. It explored the lagged relationships between mass balance and precipitation, net surface solar radiation, and temperature, and applied the random forest method to examine the relative contributions of these factors to the ice sheet’s mass balance within a nonlinear framework. The results showed that the mass loss rates of the Antarctic ice sheet during the study periods were −123.3 ± 6.2 Gt/a and −24.8 ± 52.1 Gt/a. The region with the greatest mass loss was the Amundsen Sea in West Antarctica (−488.8 ± 5.3 Gt/a and −447.9 ± 14.7 Gt/a), while Queen Maud Land experienced the most significant mass accumulation (44.9 ± 1.0 Gt/a and 30.0 ± 3.2 Gt/a). The main factors contributing to surface ablation of the Antarctic ice sheet are rising temperatures and increased surface net solar radiation, each showing a lag effect of 1 month and 2 months, respectively. Precipitation also affects the loss of the ice sheet to some extent. Over time, the contribution of precipitation to the changes in the ice sheet’s mass balance increases.

Quantum tomography with τ leptons at the FCC-ee: Entanglement, Bell inequality violation, sinθW , and anomalous couplings

The Future Circular Collider (FCC)—in its first incarnation as a lepton collider—will produce, according to the proposed design, more than 100 billion pairs of τ leptons after working for four years at the energy of the Z-boson resonance. The τ lepton is special because its relatively long lifetime makes it possible to reconstruct the momenta of neutrinos emitted in the single pion decay mode. The resulting large number of events is an ideal source for a full quantum tomography of the process that will test quantum entanglement and the violation of Bell inequality with unprecedented precision. In addition, the study of polarizations and spin correlations can provide a competitive determination of the Weinberg angle θW and constrain possible anomalous couplings in the neutral electroweak current. We utilize analytic results and Monte Carlo simulations to explore to what extent these goals might be accomplished. Published by the American Physical Society 2024

Aromaticity of Heterocyclic Compounds and Their Corrosion Inhibition Property: Experimental and Theoretical Analysis.

Heterocycle derived moieties, namely, N-(4-methoxyphenyl)-1-(1H-pyrrol-2-yl)methanimine (MPM), 1-(furan-2-yl)-N-(4-methoxyphenyl)methanimine (FMM), and N-(4-methoxyphenyl)-1-(thiophen-2-yl)methanimine (MTM), were synthesized followed by analysis of their structural aspects using FTIR and 1H NMR spectroscopic techniques. The corrosion retarding abilities of the same were distinguished by gravimetric and certain electrochemical measures for mild steel in 0.5 M H2SO4, and MTM was obtained with maximum inhibition efficiency of 97.93% at 250 mg L-1 concentration; the thermodynamic and activation parameters were recorded in this regard. The results were further seen to be supported by various surface studies: SEM-EDS, XPS, AFM, contact angle, and UV-visible spectroscopy. Potentiodynamic polarization studies unveiled the mixed nature of heterocyclic inhibitors with overriding anodic effect. Furthermore, the adsorption of inhibitors over mild steel coupons demarcates the prevalence of physical and chemical interactions in the environment. In addition, the computational studies, global and local reactivity, molecular dynamics, and density functional theory, were employed and the experimental results obtained were found in correlation with the theoretical results.

Design and development of DSPE-PEG2000/DPPC disk-like micelles for targeted delivery of icariin phytochemical in pulmonary fibrosis

Icariin (ICA)-loaded DSPE-PEG2000/DPPC disk-like micelles were synthesized utilizing the thin film hydration method to enhance the solubility and delivery of ICA to the lungs. The micellar formulation significantly improved the water solubility of ICA. This was attributed to the high encapsulation efficiency (95 %) and drug loading capacity (12 %) of the DSPE-PEG2000/DPPC micelles. Comprehensive characterization using Fourier-transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). Particle size analysis through dynamic light scattering (DLS) and transmission electron microscopy (TEM) demonstrated the formation of stable micelles with an average particle size around 10 nm.In vitro aerosolization studies using the next-generation impactor (NGI) revealed that the fine particle fraction was 63.5 ± 4 %, which means that over 60 % of the aerosolized ICA/DSPE-PEG2000/DPPC micelles were capable of reaching and targeting the deep lung alveoli, indicating their potential efficacy for pulmonary delivery. Cytotoxicity assessments via the MTT assay showed IC50 values of ICA-loaded DSPE-PEG2000/DPPC micelles were 117 ± 8 μg/mL, 29 ± 3 μg/mL, and 21 ± 1 μg/mL at 24, 48, and 72 h, respectively, highlighting the time-dependent cytotoxic effects of the ICA-loaded micelles on A549 cells. However, the IC50 values of free ICA were > 500 μg/mL, 252 ± 3 μg/mL, and 109 ± 2 μg/mL, respectively at three different time points. That indicated that ICA-loaded nano micelles enhanced the cytotoxicity of ICA. Furthermore, the cellular uptake of the nano micelles by A549 cells was visualized and confirmed using EVOS fluorescence imaging and flow cytometry techniques. In addition, RAW 264.7 M2 polarization studies indicated ICA loaded DSPE-PEG2000/DPPC micelles have potential for treating pulmonary fibrosis.These findings suggest that DSPE-PEG2000/DPPC micelles significantly enhance the solubility and delivery of ICA, presenting a promising nanocarrier system for targeted pulmonary fibrosis therapy.

Synthesis and Characterization of Ni(II) Schiff Base Complex as a Precursor for NiO Nanoparticles and an Investigation of Their Corrosion Inhibition

This study first aimed to synthesize and characterize a [Ni(C14H13NO2)(OAC)2(H2O)2] via the preparation of a ligand, coordination with Ni(II) ions, and full characterization, such as "FTIR, 1H and 13C-NMR, UV-Visible spectroscopy; and ESI-mass spectrometry" The Nickel complex was then used as a precursor to prepared NiO Nps by calcination at 450°C. The phase purity, crystalline structure, and morphological characterizes of the NiO nanoparticles were investigated via X-ray diffraction (XRD), FESEM, and FTIR spectroscopy, revealing them to be cubic system with an average crystalline is 26 nm. The preparation technique is facile, cost-effective, and rapid and suitable for generating NiO nanoparticles for use in industrial processes. Further, the corrosion inhibition effectiveness of all synthesized compounds on mild steel in 1 M HCl was evaluated. Their inhibition efficiencies were determined via potentiodynamic polarization studies, revealing the highest inhibition efficiency for the NiO nanoparticles compared to the Nickel complex and free a ligand.

How #Trad Catholics Challenge Current Constructions of Christian Nationalism: Counterknowledge, Masculinity, and Elite Aesthetics on Instagram

ABSTRACT I analyze traditionalist Catholic (or Trad) content on Instagram to add digital hyperconnectivity to current conversations about Christian nationalism in the United States. Building on studies of both epistemological and affective shifts in the age of digital hyperconnectivity, I argue that some pockets of right-wing Christian content are not anti-intellectual, but rather construct alternative knowledge bases to challenge mainstream authorities. This populist strategy of counterknowledge is mediatized in Trad Instagram, creating an epistemic community to counter those of the mainstream. The affordances of Instagram as a platform, characterized by its emphasis on visual content, brevity, and rapid consumption, have resulted in the decontextualized presentation of fragmented elements of Catholic philosophy and social teaching. This reconfiguration not only reshapes the public perception of Catholic thought but also fundamentally alters the grammar of public discourse. I draw on studies of affective polarization to argue that counterknowledge is not primarily about building a substantive alternative knowledge base, but rather about constructing an identity around the media image of an epistemic community under threat. The Trad aesthetic representation of intellectualism is distinctly gendered, presenting intellectual pursuit and reason as masculine virtues. I conclude by explaining how Trad Instagram contributes to and challenges current discourses on Christian nationalism by centering digital hyperconnectivity instead of a rationalist analysis of motivating beliefs, providing insights not only about shifts in authority and populism, but also moving beyond ideology to highlight aesthetic, affect, and the algorithmic curation of knowledge.

Corrosion Inhibition Potential of Aqueous Extract of Bauhinia acuminata Linn Leaves on Carbon Steel in Hydrochloric Acid Medium

The corrosion of carbon steel in 1 N HCl was analyzed using an aqueous Bauhinia acuminata Linn (BaL) leaf extract. Weight loss method was used to determine the inhibitor efficaciousness and corrosion rate. When dissolved in water, a linneus plant leaf extract exhibit an inhibitory effect which is proportionate to the amount of inhibitors present. It is possible to speed up the corrosion process by increasing the inhibitors’ concentration. Studies have shown that the BaL leaves extract has a 97.30% inhibitory efficiency. By increasing the concentration of inhibitor solutions, a surface layer forms on carbon steel, which inhibits the activity of the active site. The potentiodynamic polarization (PDP) and AC impedance studies (EIS) were employed to examine the mechanical properties of corrosion inhibition. The surface homogeneity and irregularity of carbon steel were examined using AFM and SEM under polished, corroded and inhibitor-treated surfaces. The surface irregularity of the carbon steel were analyzed using atomic force microscopy.

Linear polarization study of open clusters in the anticenter direction: Signature of the spiral arms

Aims. Our objective is to investigate the distribution of dust and associated large-scale structures of the Galaxy using optical linear polarization measurements of various open clusters located at different distances in the Galactic anticenter direction. Methods. We present R-band linear polarization observations of stars toward five open clusters: Kronberger 1, Berkeley 69, Berkeley 71, Berkeley 19, and King 8 in the anticenter direction. The polarization observations were carried out using the ARIES (Aryabhatta Research Institute of Observational Sciences) IMaging POLarimeter mounted on the 104 cm Sampurnanand telescope of ARIES, Nainital, making it the first study to target the polarization observations toward distant clusters (~6 kpc). We combined the observed polarization data with the distance information from the Gaia space telescope to infer the dust distribution along the line of sight. Results. The variation in the degree of polarization and extinction with distance reveals multiple dust layers in each cluster direction. In addition, common foreground-dust layers detected toward different cluster directions highlight global features such as spiral arms. Our results show that the dust clouds at 2 kpc toward Berkeley 69 and Berkeley 71 coincide with the Perseus arm, while the dust layer at ~4 kpc toward the distant clusters Berkeley 19 and King 8 indicates the presence of the Outer arm. The large-scale dust distribution obtained by combining our polarization results with previous polarization studies of nearby open clusters suggests that the anticenter direction is characterized by a low-extinction homogeneous dust distribution with a somewhat uniform orientation of the plane-of-sky component of the magnetic field along the line of sight. Conclusions. Our study demonstrates that polarization is useful as a tool for studying the large-scale dust distribution and structural features where kinematic distance methods are inadequate and cannot provide accurate distances to the dust clouds. The global dust distribution in the anticenter direction shows signatures of the intervening spiral arms.

Imidazole derivative for corrosion protection: A comprehensive theoretical and experimental study on mild steel in acidic environments

The inhibition efficiency derivative imidazole, 2-mercapto-5,5-diphenyl-3,5-dihydro-4 H-imidazol-4-one (AM0), against corrosion in a hydrochloric acid (HCl) environment was studied. The research focused on the compound's ability to adsorb onto mild steel surfaces. Various experimental techniques, including potentiodynamic polarization (PDP), electrochemical frequency modulation (EFM), and impedance spectroscopy (EIS), were employed to analyze the inhibitory effects. Results showed that the effectiveness of AM0 increased with concentration, reaching an inhibitory efficiency of 95.1 %. Polarization studies revealed that the inhibitor displayed mixed-type behavior. The adsorption process was modeled using the Langmuir adsorption model. Surface characterization techniques such as scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDS), and X-ray photoelectron spectroscopy (XPS) were utilized to examine the inhibited corrosion surfaces. Theoretical calculations based on density functional theory (DFT) and density functional tight binding (DFTB) suggested that inhibitors with electron-accepting capabilities exhibited strong interactions with the iron surface, shedding light on specific bond formations that contribute to the stability and interaction dynamics at the molecular interface. This study provides valuable information on the corrosion inhibition potential of the new imidazole compound, offering important pointers for the development of effective corrosion inhibitors in acidic environments.

Influence of Pumping Laser Intensity Uniformity on Hybrid Optically Pumped Comagnetometer in the SERF Regime

AbstractThe effect of pumping laser intensity uniformity (PLIU) on the operation of a hybrid optically pumped comagnetometer operating in the spin‐exchange relaxation‐free regime (SERF) regime is investigated in this paper. First, an analytical steady‐state output model for the comagnetometer with two alkali‐metal atoms and one noble‐gas atom is presented. By varying the diameter of the pumping laser beam to control the PLIU, 3D distribution models of the electron spin and nuclear spin polarization under different PLIU conditions are obtained. In the experiment, the effects of PLIU on multi‐parameter, low‐frequency magnetic‐noise suppression capability, and long‐term stability of the SERF comagnetometer are studied. The results indicate that within a certain range, increasing the diameter of the pumping laser beam improves the polarization uniformity of the atomic ensemble and reduces the light shift of the comagnetometer. As a result, both the low‐frequency magnetic noise suppression capability and the long‐term stability of the system increase. However, further reduction of the pumping laser diameter leads to a reversal of the system performance metrics, suggesting the presence of a tipping point. The research presented in this article is critical for advancing the efficient polarization study and hyperpolarization of SERF comagnetometers.

Polarized ATR-FTIR studies of DPPC/DPPG lipid bilayers doped with PLL

The structural characterization of lipid bilayers is crucial for understanding various biological processes and designing effective systems of drugs. Attenuated Total Reflection Fourier Transformed Infrared (ATR-FTIR) spectroscopy is a powerful technique for probing lipid membrane properties, but conventional methods face challenges in discerning molecular orientation and intermolecular interactions. The polarized ATR-FTIR spectroscopy combined with Principal Component Analysis (PCA) was used to investigate the interactions between positively charged peptide (poly-L-lysine (PLL)) and anionic lipid bilayers (dipalmitoylphosphatidylcholine/dipalmitoylphosphatidylglycerol, DPPC/DPPG). This integrated approach offers deeper insight into mutual interactions between proteins and lipids of membrane, providing a comprehensive understanding of structure of both protein and lipid bilayers components. The findings of this study shed light on the orientational order of lipid molecules in DPPC/DPPG membrane structure as well as secondary strictures of PPL peptides. It was shown that the presence of PLL peptide disrupts lipid molecule ordering within the lipid bilayer, primarily through electrostatic and H-bond interactions. The utility of polarized ATR-FTIR spectroscopy supported by PCA calculations in elucidating molecular organizations within complex membrane systems is emphasized.

An electrochemical and theoretical approach towards the efficient microwave synthesis of imidazolium-based ionic liquids for unprecedented mild steel corrosion inhibition in 0.5 M H2SO4 solution

The inhibition potential of newly synthesized imidazolium-based ionic liquids (IL-1 and IL-2) on mild steel corrosion in a 0.5 M H2SO4 solution has been comprehensively investigated using gravimetric analysis, potentiodynamic polarization, and electrochemical impedance spectroscopy across various temperatures. Gravimetric analysis indicated that the adsorption of these inhibitors adhered to the Langmuir adsorption isotherm. Significantly, IL-2, featuring a longer alkyl chain, demonstrated superior inhibition efficiency (92.51 % at 303 K) compared to IL-1 (88.71 % at 303 K). Potentiodynamic polarization studies revealed a mixed-type inhibitory behavior, impacting both anodic and cathodic reactions. Surface morphological analyses via SEM and EDX confirmed the formation of a protective film on the mild steel surfaces, substantiating the corrosion inhibition capabilities of IL-1 and IL-2. The novelty of this research lies in the application of density functional theory (DFT) using the B3LYP method, which elucidated that the alkyl chain length at the N-3 position in imidazolium cation-based ionic liquids significantly enhances their inhibition potential. This mechanistic insight suggests that these ionic liquids effectively obstruct both anodic and cathodic sites, providing robust corrosion protection in a 0.5 M H2SO4 solution.

Polarization Study of Swift J151857.0–572147 with IXPE Observation

We present an analysis of the Imaging X-ray Polarimetry Explorer observation from a newly discovered transient source: Swift J151857.0–572147. The obtained polarization degree (PD) and angle are 0.3% ± 0.3% and −24° ± 26° respectively in 2–8 keV within 68% confidence level errors, and polarization results are below MDP99 in all energy bins, with the upper limit on PD of 0.8% in the 2–8 keV energy range. No quasi-periodic oscillations (QPOs) are detected in this observation. The polarization and QPO analyses support the hypothesis that the source was in the high soft state, and the results are consistent with predictions for a thin accretion disk model.

Sodium salt of dodecyl benzene sulphonic acid as an effective corrosion inhibition for different heat-treated steel in sulphuric acid medium

Abstract The purpose of this work is to use electrochemical and gravimetric techniques to investigate the inhibition of DBSS on the corrosion of heat-treated dual-phase AISI 1040 steel in a 0.5 M sulphuric acid solution at 35 °C. The corrosion studies are performed by potentiodynamic polarization study (PDP), electrochemical impedance study (EIS), and gravimetric method. To confirm the inhibition surface characterization like x-ray diffraction technique (XRD) analysis, scanning electron microscopy (SEM), and EDS analysis are performed. Depending on the phase change of metals due to heat treatment, the corrosion inhibition of the heat-treated metal increased when it was exposed to 0.5 M H2SO4 at 35 °C in the presence of dodecyl benzene sulphonic acid sodium salt (DBSS) inhibitor. The highest inhibition efficiency of 63%, 82%, 87%, 43%, and 63% was obtained for AISI 1040 steel at heat treatment conditions of Normalized, Quenched at 700 °C, Quenched at 750 °C, Quenched at 790 °C and Quenched at 900 °C respectively. In the gravimetric and electrochemical study, the IE increases with the increase with the concentration of DBSS unto 75% from gravimetric analysis and 87% from PDP analysis for Quenched at 750 °C and 790 °C respectively. The metal protection is achieved by heat treatment process as well as by using DBSS as inhibitor. Corrosion inhibition on the metal’s surface was confirmed by SEM and XRD. In addition, the adsorption of DBSS on the anodic and cathodic sites of the metal surface was well explained.