Polarization Measurements Research Articles

Enhanced Experimental Setup and Methodology for the Investigation of Corrosion Fatigue in Metallic Biodegradable Implant Materials

Biodegradable implants as bone fixations may present a safe alternative to traditional permanent implants, reducing the risk of infections, promoting bone healing, and eliminating the need for removal surgeries. Structural integrity is an important consideration when choosing an implant material. As a biodegradable implant is being resorbed, until the natural bone has regrown, the implant material needs to provide mechanical stability. However, the corrosive environment of the human body may affect the fatigue life of the material. Conversely, mechanical stress can have an effect on electrochemical corrosion processes. This is known as corrosion fatigue. In the presented work, an experimental setup and methodology was established to analyze the corrosion fatigue of experimental bioresorbable materials while simultaneously monitoring the electrochemical processes. A double-walled measurement cell was constructed for a three-point bending test in Dulbecco‘s Phosphate-Buffered Saline (DPBS− −), which was used as simulated body fluid (SBF), at 37 ± 1 °C. The setup was combined with a three-electrode setup for corrosion measurements. Rod-shaped zinc samples were used to validate the setup’s functionality. Preliminary static and dynamic bending tests were carried out as per the outlined methodology to determine the test parameters. Open-circuit as well as potentiostatic polarization measurements were performed with and without mechanical loading. For the control, fatigue tests were performed in an air environment. The tested zinc samples were inspected via scanning electron microscopy (SEM). Based on the measured mechanical and electrochemical values as well as the SEM images, the effects of the different environments were investigated, and the setup’s functionality was verified. An analysis of the data showed that a comprehensive investigation of corrosion fatigue characteristics is feasible with the outlined approach. Therefore, this novel methodology shows great potential for furthering our understanding of the effects of corrosion on the fatigue of biodegradable implant materials.

Advancing the Understanding of Microplastic Weathering: Insights from a Novel Polarized Light Scattering Approach.

Weathering is a significant process that alters the properties of microplastics (MPs) and consequently affects their environmental behaviors. In this study, we introduced a novel approach based on polarized light scattering technique, which offers advantages in terms of rapid, high-throughput, and submicron-sized detection. This technique was successfully applied to characterize the weathered MPs after a 180-day laboratory simulation of coastal environments. By employing polarization measurements, we obtained a 46-dimensional matrix data set for the weathered MP fragments and subsequently processed them using a backpropagation neural network. The successful extraction of effective polarization pulses confirmed the presence of MP fragments within the size range of 0.2-60 μm, yielding total accuracies for size classification ranging from 78.9 to 86.9%. Furthermore, this technique achieved an overall accuracy of 93.8% in classifying MPs with different weathering degrees and polymer types, revealing polarization parameters associated with size and morphological changes play a dominant role in characterizing the weathering process of MPs. Compared with conventional approaches, the novel polarized light scattering approach holds great promise for rapid, high-throughput, and accurate characterization of MPs with small sizes. The findings of this study provided new insights into how MPs change after long-term weathering in aquatic environments.

Spectral induced polarization measurements to detect different scales in oil and gas production tubing

Different varieties of scales, such as iron sulfide (FeS) scale, and calcium carbonate (CaCO3), commonly precipitate within oil and gas production tubing, posing operational challenges and production losses. It is essential to implement efficient mitigation strategies and preserve production integrity to detect and characterize these scales in an accurate and efficient manner. Prior studies have explored Spectral induced Polarization (SIP) for the early detection of FeS within porous media, mainly for environmental applications or for identifying FeS in carbonate formations from the perspective of reservoir characterization. This study focuses on applying SIP to address production-related issues in production tubing. For this purpose, six actual subsurface scale samples were analyzed using X-ray Diffraction, X-ray Fluorescence, and SIP techniques. These samples were categorized into three primary groups based on their composition: Pyrrhotite, Goethite, and Calcium Sulfate Hydrate or Calcite. The results indicate that combining phase shift and conductivity as frequency functions makes it possible to develop an approach to classify and differentiate between various scale types. This information could be instrumental in developing methods that can be potentially integrated into tubing systems to detect and characterize the different scale types.

One-Step Magneton Sputtering of Crystalline Cu-Doped TiO2 Coatings: Characterization and Antibacterial Activity

Early biofilm formation could be inhibited by applying a thin biocompatible copper coating to reduce periprosthetic infections. In this study, we deposited crystalline Cu-doped TiO2 films using one-step DC magnetron sputtering in an oxygen atmosphere on a biased Ti6Al4V alloy without external heating. The bias voltage varied from −25 V to −100 V, and the resultant substrate temperature was measured. The deposited coatings were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), microhardness, scratch and hydrophilicity tests, potentiodynamic polarization measurements, and antibacterial assays against S. aureus and E. coli. The findings demonstrated that when a higher negative bias is applied, the substrate temperature drops, and the anatase to rutile transformation is initiated without indicating obvious Cu-containing phases. The SEM images of the films showed spherical agglomerates with homogeneously distributed Cu with decreasing Cu content as the bias value increased. Higher bias results in the grain refinement of the thinning coatings with more lattice microstrain and more defects, together with an increase in water contact angles and hardness values. Samples biased at −75 V exhibited the highest adhesive strength between coatings and substrate, whereas the specimen biased at −50 V demonstrated higher corrosion resistance. Cu-containing TiO2 coatings with pure anatase phase composition and Cu concentrations of 2.62 wt.% demonstrated excellent bactericidal activity against both S. aureus and E. coli. The layers containing 2.34 wt.% Cu exhibited very good antibacterial properties against S. aureus, only. According to these findings, the produced copper-doped TiO2 coatings have high bactericidal qualities in vitro and may be used to prepare orthopaedic and dental implants in the future.

Synergistic inhibition effect of Chlorella sp. and benzotriazole on the corrosion of Q235 carbon steel in alkaline artificial seawater

The interaction of microalgae on the reinforced concrete with corrosion inhibitor is not well understood. Moreover, the inhibition role of microalgae on corrosion has been reported in recent years. In this study, the corrosion inhibition behavior of Q235 carbon steel (CS) due to the presence of Chlorella sp. and benzotriazole (BTA) in alkaline artificial seawater was investigated by means of weight loss, electrochemical measurements including open circuit potential, electrochemical impedance spectroscopy, and potentiodynamic polarization curves, and surface analysis including scanning electron microscopy, energy dispersion spectrometer, and X-ray photoelectron spectroscopy. The results of reduced corrosion rates in the algae-BTA system demonstrated that Chlorella sp. could facilitate the corrosion inhibition efficiency of BTA on the CS specimens. Moreover, polarization measurement showed the algae-BTA system had a mixed-type corrosion inhibition effect. The mechanisms of inhibition were proposed to be the precipitation of iron complexes such as Fe-BTA-EPS and Fe-BTA and iron compounds on the steel surface in the presence of the microalgae and BTA–. This study highlights the application of CS corrosion control by combining biological and chemical approaches that can be used for future research and practice, rather than purely chemical approaches.

Synthesis of Schiff bases of 4-methoxybenzyl amine and hydrazide derivatives and their application in corrosion inhibition of mild steel in 1.0 M HCl

In this work, Schiff bases of 4-methoxybenzyl amine and hydrazide derivatives containing succinic (BMSHE), oxalyl (BMOHE), and phenylaceto (BMPHE) have been synthesized and applied for corrosion inhibition of mild steel (MS) in 1.0 M HCl. The synthesized compounds are characterized by Fourier-transform infrared (FTIR) and H1 nuclear magnetic resonance (NMR) spectroscopy. The FTIR and H1 NMR results have confirmed their formation through the presence of functional groups and hydrogen associated with them. Corrosion mitigation examination is done by polarization measurements (PM), electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) equipped with energy dispersive X-rays (EDX), and atomic force microscopy (AFM). All inhibitors demonstrated notable efficacy in preventing MS in HCl (BMSHE-88%, BMOHE-84%, and BMPHE-72%). As per corrosion potentials, BMOHE and BMPHE have been found to be mixed types of inhibitors, and BMSHE is noticed as a cathodic inhibitor. The SEM results demonstrated how these hydrazide derivatives prevented corrosion by covering the MS surface. The EDX analysis of the surfaces has revealed that the inhibited MS contains lower amounts of O and Cl, which indicate that the inhibitors prevent MS in HCl. AFM analysis shows that the surfaces of MS in the presence of the inhibitors are damaged less than in their absence, which reveals the same facts as told above. The inhibition of MS by BMSHE, BMOHE, and BMPHE is also explained with a reason after analyzing the results.

Minimize flow-induced uncertainty in polarization sensitive optical coherence tomography imaging using eigen decomposition.

Blood flow alters the scattering behavior of penetration light, causing instability in the polarization state to emerge at the underlying tissue during polarization-sensitive optical coherence tomography (PSOCT). We propose an eigen decomposition method to meet this challenge, where the static and dynamic scattering signals are separated for PSOCT to provide the polarization measurements of the tissue of interest that is located beneath the blood flow. Using flow phantoms made by Intralipid solution and 3D-printed birefringent material, we show the flow-induced effects on the measurements of sample birefringent properties of optical axis, phase retardation, and degree of polarization uniformity. We demonstrate the usefulness of the proposed method through in vivo imaging of the human nail fold.

Effect of metalloid element on the microstructural and mechanical properties of AlCoCrCuFeNi high-entropy alloys

ABSTRACT The impact of the metalloid element silicon (Si) addition on the microstructural and mechanical properties of the AlCoCuCrFeNiSix high-entropy alloy system is examined in this paper. The alloys were synthesized using a vacuum arc melting route. X-ray diffraction was used to analyse the current high-entropy alloys’ phase formation to comprehend the alloying process’s behaviour. It is evident from the peak pattern of the X-ray diffraction that the inclusion of Si promotes the growth of body-centred cubic structures. The microhardness and wear resistance were increased by increasing the Si content from 0 to 0.9. Si presence enhances the hardness of the alloys and strengthens the grain boundary. Improved hardness and wear resistance results from the enhanced body-centred cubic-phase formation, which poses a barrier to the dislocation movement and prevents further deformation. Furthermore, the inclusion of Si improved corrosion resistance in potentiodynamic polarization measurements. Excellent compressive strength is possessed by all of the high-entropy alloys with Si addition.

X-ray spectropolarimetric characterization of GX 340+0 in the horizontal branch: A highly inclined source?

We report the first detection of X-ray polarization in the horizontal branch for as obtained by the Imaging X-ray Polarimetry Explorer ( A polarization degree of 4.3<!PCT!>pm 0.4<!PCT!> at a confidence level of 68<!PCT!> is obtained. This value agrees with the previous polarization measurements of Z-sources in the horizontal branch. The spectropolarimetric analysis, performed using a broadband spectral model obtained by and quasi-simultaneous observations, allowed us to constrain the polarization for the soft and hard spectral components that are typical of these sources. The polarization angle for the two components differs by sim This result can be explained by a misalignment of the NS rotation axis with respect to the accretion disk axis. We compared the results with the polarization that is expected in different models. Theoretical expectations for the polarization of the disk and the Comptonization components favor a higher orbital inclination for than 60 as expected for Cyg-like sources. This is in contrast with the results we report for the reflection component based on the broadband spectrum.

Polarization and hate speech based on fuzzy logic and transformers: the case of the 2023 Spanish general elections

ABSTRACT Affective polarization in the digital debate of the Spanish presidential election campaign (2023), following the sudden call of the Spanish president on July 23, was measured. Using transformers, topics were detected, and sentiment analysis techniques were applied in the political debate during the elections to measure the emotional valence of the debate. The topics that dominate most of the debate are Candidates (n1 = 17170) and Opposition (n3 = 15327). These topics also show the highest typical polarization deviances. Based on affective polarization, a polarization measure (JDJ) grounded in the fuzzy sets was applied. The topic activism has the highest polarization value, while the topic of voting has the lowest. This analysis highlights a dichotomy that defines the Spanish political reality: the positive image of conventional political participation in the face of the rejection of collective action processes.

New high-precision measurement system for electron–positron pairs from sub-GeV/GeV gamma-rays in the emulsion telescope

The GRAINE project observes cosmic gamma-rays, using a balloon-borne emulsion-film-based telescope in the sub-GeV/GeV energy band. We reported in our previous balloon experiment in 2018, GRAINE2018, the detection of the known brightest source, Vela pulsar, with the highest angular resolution ever reported in an energy range of >80MeV. However, the emulsion scanning system used in the experiment was designed to achieve a high-speed scanning, and it was not accurate enough to ensure the optimum spatial resolution of the emulsion film and limited the performance. Here, we report a new high-precision scanning system that can be used to greatly improve the observation result of GRAINE2018 and also be employed in future experiments. The scanning system involves a new algorithm that recognizes each silver grain on an emulsion film and is capable of measuring tracks with a positional resolution for the passing points of tracks of almost the same as the intrinsic resolution of nuclear emulsion film (∼70 nm). This resolution is approximately one order of magnitude smaller than that obtained with the high-speed scanning system. With this scanning system, an angular resolution for gamma-rays of 0.1° at 1GeV is expected to be achieved. Furthermore, we successfully combine the new high-precision scanning system with the existing high-speed scanning system, enabling the high-speed and high-precision measurements. Employing these techniques, we reanalyze the gamma-ray events detected previously by only the high-speed scanning system in GRAINE2018 and obtain an about three times higher angular resolution (0.22°) in the 500–700MeV energy range. Adopting this technique in future observations may provide new insights into the gamma-ray emission from the Galactic center region and may realize polarization measurements of high-energy cosmic gamma-rays.

Measurement of microwave polarization using two polarization orthogonal local microwave electric fields in a Rydberg atom-based mixer

We propose and demonstrate what we believe to be a novel method for measuring the polarization direction of a microwave electric field in a single measurement using a Rydberg atom-based mixer with two orthogonally polarized local microwave electric fields. This approach eliminates the need for physical rotation of the local field, allowing the polarization angle of the signal field to be determined directly by measuring the ratio of the two beat signals. Furthermore, introducing a weak static magnetic field enables the utilization of the Zeeman effect and exploitation of polarization asymmetry. This distinction allows for determining the polarization direction of the microwave field is θ or 180° – θ within the 0 to 180-degree range. The capability to measure microwave polarization in real-time across this range is very valuable for applications in microwave sensing and information transmission.

Improved Electrode Performance Using Fine‐Tuned Poly(arylene piperidinium) Ionomers In Anion Exchange Membrane Fuel Cells

AbstractIonomers based on poly(arylene piperidinium)s with varying ion exchange capacities are evaluated in different combinations of anode and cathode electrodes in anion exchange membrane fuel cells. The operational conditions are chosen with an asymmetrical regime including a dry anode with 50% relative humidity at the inlet, and full humidification at the cathode. Polarization and impedance measurements are carried out in potentiostatic steps within 0.3–0.9 V and distribution of relaxation times analysis is utilized to deconvolute resistance contributions. The results show that the best cell performance is achieved with both electrodes utilizing an ionomer with the highest ion exchange capacity (IEC) of 2.79 meq g−1. Cells built exclusively from this ionomer achieved a peak power density of 1.01 W cm−2. Deconvolution of the resistance contributions revealed the impact of water content on the effective charge transfer resistance in both electrodes and a diffusion resistance associated with the movement of water from anode to cathode side. The higher conductivity and water uptake of the high IEC ionomer resulted in a reduction of both resistance contributions, leading to the highest performance under the conditions evaluated. These findings provide important insights into how to tailor the electrode layers for optimum fuel cell output.

Analysis of interference fringes in a long-wave infrared full Stokes polarimeter based on rotating waveplates

In the long-wave infrared (LWIR, 8–15 µm) band, the interference effect of polarization elements becomes an issue in polarimetry due to defects in the anti-reflective coatings. The paper describes an analysis and optimization method for the rotating-waveplates-based Stokes polarimeter, to eliminate interference fringes and improve polarization measurement accuracy in LWIR. An interference model was established based on the theory of polarized light and thin-film optics. Different modulation schemes were simulated and analyzed to obtain an optimized Stokes polarimeter, reducing the instrumental polarization to less than 1E-3. Furthermore, experimental validation was conducted by the Accurate Infrared Magnetic Field Measurements of the Sun (AIMS) telescope. The result shows that the instrumental polarization was less than 2E-3, consistent with the simulation.

Electrochemical, surface, and theoretical investigations of palm kernel shell extract as an effective inhibitor for carbon-steel corrosion in 1M HCl solution.

Herein, we employed palm kernel shell extract (PKSE) as an eco-friendly inhibitor for carbon steel in acidic-induced corrosion. The corrosion inhibition of PKSE on carbon steel in 1M HCI solution was investigated by electrochemical impedance spectroscopy, weight loss, and potentiodynamic polarization measurements. The surface was characterized by scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy. Moreover, the elastic modulus and hardness tests were conducted. Weight loss measurements revealed that the optimum concentration of inhibitors is 500ppm with 95.3% inhibition efficiency in 1M HCl solution. Electrochemical results showed that the inhibitor could exhibit excellent corrosion inhibition performance and displayed mixed-type inhibition. The electrochemical impedance spectroscopy analysis shows that the inhibition performance increases by increasing the concentration of PKSE. The surface studies ensure the PKSE effectiveness in carbon steel surface damage reduction. Also, the adsorption of PKSE molecules on the carbon steel surface occurs according to the Langmuir isotherm model. The primary goal of this investigation was the utilization of palm kernel shell extract as corrosion inhibitor for 1018 low carbon steel in 1M HCl solution, which highlights its novelty. The present results will be helpful to uncover the versatile importance of palm kernel shell compounds in the corrosion inhibition process.

Enhancing corrosion resistance of lightweight metal alloys through laser shock peening

In this study, we investigated the effects of laser shock peening (LSP) on the corrosion resistance of lightweight metal alloys, specifically AA6061 and AZ31. LSP was performed underwater, using a nanosecond pulse laser and without using a protective coating or layer on the workpiece. The corrosion behaviors of these alloys were analyzed through electrochemical tests, including open circuit potential, electrochemical impedance spectroscopy, and potentiodynamic polarization measurements. The results demonstrated that LSP significantly improved the polarization resistance, and higher laser power intensities led to increased corrosion resistance and reduced corrosion rates. This enhancement in anti-corrosion performance is attributed to the formation of a protective oxide layer on the surface, acting as a barrier against corrosion. The findings underscore the potential of laser surface treatment as a viable technique for enhancing the corrosion resistance of lightweight metal alloys.

An Antiferroelectric‐Coated Metal Foam Infiltrated with Liquid Metal as a Dielectric Capacitor

Nickel metal foams serve as both a substrate and bottom electrode for a dielectric capacitor using atomic‐layer deposition (ALD) and a eutectic gallium–indium (EGaIn) liquid metal (LQM) counter electrode. The conformal dielectric has a composition of 6.25% Al–HfO2 in the antiferroelectric phase, confirmed with polarization versus electric field measurements. Liquid EGaIn is pressure‐infiltrated within the coated foams to form the dielectric capacitor. Capacitances up to 4 μF are realized. Calorimetry of the infiltrated capacitor shows a 60 J g−1 latent heat upon melting a frozen EGaIn electrode, suggesting that the phase change can alleviate thermal deviations from pulsed power capacitor operation. Infiltrated capacitors are also shown to survive bending and freeze–thaw cycles. The metal foam–ALD dielectric–LQM capacitor shows a combined set of thermal and electrical properties not available in other classes of capacitors.

Hardness and corrosion resistance of Zn coatings on mild steel obtained by electrodeposition and hot-dip galvanization

The purpose of this work is a comparative study of the characteristics of the layers of Zn on a substrate of mild steel from two different processes (electrodeposition and galvanizing), and to review the progress that has been made in understanding the intermetallics phases’ effect on the corrosion behavior. The obtained Zn-containing film was investigated using diverse instrumental methodologies such as microhardness, X-ray diffraction, and potentiodynamic polarization measurements. This study allows the conclusion that the layers of Zn developed have: a homogeneous structure and good hardness. The corrosion test results showed an improvement in corrosion resistance for electrodeposition coatings compared with galvanizing coatings. XRD results identify that the electrodeposition and the galvanizing coatings have similar phases and the maximum hardness is obtained for the galvanizing process. Intermetallic phases were found to influence the corrosion behavior of mild steel. The results show that the size of Fe–Zn particles gradually decreases with the immersion time.

Fluorescence Polarization Assay for Infection Diagnostics: A Review

Rapid and specific diagnosis is necessary for both the treatment and prevention of infectious diseases. Bacteria and viruses that enter the bloodstream can trigger a strong immune response in infected animals and humans. The fluorescence polarization assay (FPA) is a rapid and accurate method for detecting specific antibodies in the blood that are produced in response to infection. One of the first examples of FPA is the non-competitive test for detecting brucellosis in animals, which was followed by the development of other protocols for detecting various infections. Fluorescently labeled polysaccharides (in the case of brucellosis and salmonellosis) or specific peptides (in the case of tuberculosis and salmonellosis, etc.) can be used as biorecognition elements for detecting infections. The availability of new laboratory equipment and mobile devices for fluorescence polarization measurements outside the laboratory has stimulated the development of new fluorescence polarization assays (FPAs) and the emergence of commercial kits on the market for the detection of brucellosis, tuberculosis, and equine infectious anemia viruses. It has been shown that, in addition to antibodies, the FPA method can detect both viruses and nucleic acids. The development of more specific and sensitive biomarkers is essential for the diagnosis of infections and therapy monitoring. This review summarizes studies published between 2003 and 2023 that focus on the detection of infections using FPA. Furthermore, it demonstrates the potential for using new biorecognition elements (e.g., aptamers, proteins, peptides) and the combined use of FPA with new technologies, such as PCR and CRISPR/Cas12a systems, for detecting various infectious agents.

Hf0.4Zr0.6O2 Thickness-Dependent Transfer Characteristics of InxZn1-xOy Channel Ferroelectric FETs.

We investigate how the threshold voltage (VT) is adjusted to create a memory window (MW) in ferroelectric field-effect transistors (FeFETs) composed of ferroelectric Hf0.4Zr0.6O2 and InZnO (In2O3:ZnO = 9:1 wt %). Temperature-dependent polarization measurements reveal a dipole switching in Hf0.4Zr0.6O2. The properties of the n-type InZnO channel are examined by fabricating an oxide transistor with an HfO2 gate dielectric. Upon replacement of HfO2 with Hf0.4Zr0.6O2 in the oxide transistor, a counterclockwise MW is observed. Specifically, as the Hf0.4Zr0.6O2 thickness increases from 16 to 24 nm, the VT of the FeFET after a + gate voltage (VG) sweep remains nearly constant, while the VT after a -VG sweep shifts significantly from -0.9 to 0.5 V. The enlarged MW of approximately 2 V, which is proportional to the Hf0.4Zr0.6O2 thickness in the FeFET, can be explained by considering the balance between VG controllability across the gate stack and the ferroelectric switching of Hf0.4Zr0.6O2.