Scanning Direction Research Articles

Effect of Process Parameters on Distortions Based on the Quantitative Model in the SLM Process

The selective laser melting (SLM) process provides a more extensive design space and manufacturability. However, it is still hindered by its inaccuracy in dimension and functionality. The distortion in the SLM process affects the dimensional accuracy of the component and may even hinder the SLM process. Still, the distortion mechanism has not been well explained; specifically, the effects from the process parameters and scan strategies on the distortion have not been sufficiently investigated. In this study, a quantitative model that considers displacements, plastic strains, and thermal strains on each layer is developed to analyze the distortion mechanism. The distortion is found to be induced by a residual stress gradient among the layers. Then, a transient numerical method calculates residual stress, plastic strain, and distortion in the SLM process. Different simulations with various layers, scanning speeds, stiffness of support structures, and scan strategies are performed to study the relationship between process parameters and distortion. It can be found that the distortion decreases as the height increases. The distortion increases with the scanning speed, reaching the maximum at 700 mm/s and then dropping. We concluded that increasing the stiffness of the support structures is beneficial to reduce the distortion and changing the scanning direction among layers is useless to reduce the distortion. This study gives a theoretical model to analyze the distortion and provides guidance for reducing distortions in the SLM process.

Control of ferroelectric and ferromagnetic domains in BiFe0.9Co0.1O3 thin films by utilizing trailing fields

The effect of in-plane “trailing fields” caused by the scanning motion of a biased cantilever on ferroelectric and ferromagnetic domains of a BiFe0.9Co0.1O3 thin film was investigated. BiFe0.9Co0.1O3 is applicable for an ultra-low power consumption nonvolatile magnetic memory device because the magnetization is reversible by an electric field. In-plane polarization reversal was induced by the trailing field, which was approximately 1/6 of the electric field necessary for the polarization reversal using planar gap electrodes. The in-plane polarization direction of striped domain variants can be reversed by changing the slow scan direction of the cantilever keeping the bias voltage.

Grouping design method dependence on an illumination system and large off-axis distance for an anamorphic extreme ultraviolet lithography objective

High-numerical-aperture (NA) anamorphic extreme ultraviolet lithography (EUVL) is the next-generation technology to achieve a 3 nm node and below. Current EUVL anamorphic projection objectives in publications are designed with small off-axis distance of the field of view (FOV). Further, the ray path of the illumination system will be obscured by the last mirror of the objective. In fact, as the NA increases, the diameter of the last mirror of the objective becomes larger. Thus, the off-axis distance of the FOV should be larger to ensure that the ray path of the illumination system is not obscured by the objective. It is well known that the design of an anamorphic EUVL objective with large off-axis distance is very challenging. In this paper, a high-NA anamorphic EUVL objective with large off-axis distance is designed. The value of the large off-axis distance that satisfies the unobscured constraint is first analyzed. Then an 8× demagnification isomorphic objective with large off-axis distance is designed by a grouping design process. Finally, the XY polynomial surface is adopted to achieve a 4× demagnification perpendicular to the scanning direction. This method is implemented to design a NA 0.55 anamorphic EUVL objective with large off-axis distance. The performance of the designed objective demonstrates that this design method is very effective and will provide a good structure of the objective for the illumination system design.

Endoscopic en-face optical coherence tomography and fluorescence imaging using correlation-based probe tracking.

Forward-viewing endoscopic optical coherence tomography (OCT) provides 3D imaging in vivo, and can be combined with widefield fluorescence imaging by use of a double-clad fiber. However, it is technically challenging to build a high-performance miniaturized 2D scanning system with a large field-of-view. In this paper we demonstrate how a 1D scanning probe, which produces cross-sectional OCT images (B-scans) and 1D fluorescence T-scans, can be transformed into a 2D scanning probe by manual scanning along the second axis. OCT volumes are assembled from the B-scans using speckle decorrelation measurements to estimate the out-of-plane motion along the manual scan direction. Motion within the plane of the B-scans is corrected using image registration by normalized cross correlation. En-face OCT slices and fluorescence images, corrected for probe motion in 3D, can be displayed in real-time during the scan. For a B-scan frame rate of 250 Hz, and an OCT lateral resolution of approximately , the approach can handle out-of-plane motion at speeds of up to 4 mm/s.

Agreement of different OCT scan directions for individual retinal-layer thickness measurements in multiple sclerosis subjects with prior unilateral optic neuritis

The similarities between horizontal and vertical Optical Coherence Tomography (OCT) scans for the individual retinal layer thickness measurements in the macula was evaluated. Two volumetric scans (B-scans oriented horizontally and vertically) were performed in 64 multiple sclerosis subjects with history of unilateral optic neuritis and 64 healthy controls. The agreement between the thickness measurements with horizontal and vertical OCT scans was evaluated in 3 groups of eyes: healthy controls, eyes with history of optic neuritis and the fellow eyes. The mean difference in individual layer thickness between the scans was smaller than the instrument’s axial resolution in all 3 groups. The limit of agreement (LoA) varied among the different layers and sectors analyzed and this trend was similar in all the groups. For the inner retinal layers (retinal nerve fiber layer to inner nuclear layer), the inner macular sectors had a larger LoA compared to the corresponding outer sectors. In the outer plexiform and nuclear layers, the central and inner sectors (except inner temporal) had LoA larger than the other sectors and layers. The larger LoA seen for different layers and sectors suggests that the scan direction must be same for the follow-up OCT measurements and in clinical studies.

NOAA-20 VIIRS On-Orbit Geometric Data Quality Estimation Using the Scheduled Lunar Collections

The second Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard the National Oceanic and Atmospheric Administration (NOAA) 20 satellite has been successfully operating since its launch on November 18, 2017. Since VIIRS does not include onboard calibrators to perform the on-orbit geometric data quality characterization for parameters such as the modulation transfer function (MTF) and band-to-band registration (BBR), the monthly scheduled lunar observations are used in this study. The radiometric property of the moon surface has demonstrated its long-term stability and it is also a suitable spatial target for the on-orbit calibration of remote sensing instruments. Using the commonly practiced methodologies, the VIIRS BBR results are derived in the scan and track directions. The initial trends show that the VIIRS BBR is very stable on-orbit within ±0.1 pixels in both scan and track directions meeting the highest requirements of within 0.2 pixels. Using the sharp edge of the moon, the scan-direction MTF at the Nyquist frequency was approximately 0.23. The MTF values are well above the specification of 0.3 in imaging (I)-bands and they are very stable over the study period, whereas the moderate-resolution (M)-bands results were slightly below the specification line as suggested by prelaunch test results. The scan-direction MTF estimations were consistently near 0.2 over four years of operations. Track-direction MTF values showed oscillations because of the annual cycle of lunar shadow angle and spatial features in the moon side. However, the track-direction MTF values met the specification with large margin.

Systematic Geolocation Errors of FengYun-3D MERSI-II

Geolocation accuracy is a critical issue for remote sensing applications. To achieve subpixel accuracy, geolocation errors need to be systematically identified and corrected. In this study, we propose a geometric sensor model for FengYun-3D (FY-3D) MERSI-II, a second-generation visible (VIS)/infrared (IR) spectroradiometer, to generate the geolocation lookup table (GLT). The geometric sensor model retrieves the imaging rays from the focal plane to the K-mirrors, 45° scanning mirrors, the platform, and the earth’s surface. After refining the attitude errors with ground control points (GCPs), the rigorous sensor model can achieve subpixel geolocation accuracy. However, significant systematic geolocation errors were identified from the residuals, especially for the area with large view angles. To study the errors of MERSI-II, we proposed a homogenous coordinate in the focal plane. As proven by both theory and experiments, the attitudes were adjusted to a wrong value and introduced systematic errors when there were principal point errors. The pitch angle error of K-mirrors caused the oscillation in the flight direction. The principal distance error introduced line coordinate-related error in the flight direction. Meanwhile, the initial phase angle error between the K-mirror and 45° scanning mirrors caused the line coordinate-related errors in the scanning direction. After correcting all the above-mentioned errors, the systematic geolocation errors of MERSI-II were removed. With 23 independent datasets, the root mean square errors (RMSEs) of 250 m bands were approximately 0.4 pixels, 100 m at nadir.

Algorithm for extraction of identification features in ear recognition

The algorithm for feature extraction with the help of cosine transformation in ear recognition is presented. The software was developed on the base of proposed algorithm. The proposed algorithm was tested on solving the problem of person identification by ear images. Collecti on does not have an associated hygiene issue, as may be the case with direct contact fingerprint scanning, and is not likely to cause anxiety, as may happen with iris and retina measurements.

An Intensity-Augmented LiDAR-Inertial SLAM for Solid-State LiDARs in Degenerated Environments

With development of LiDAR technology, solid-state LiDARs receive a lot of attention for their high reliability, low cost and light weight. However, compared with traditional rotating LiDARs, these solid-state LiDARs pose new challenges on simultaneous localization and mapping (SLAM) due to their small field of view (FoV) in horizontal direction and irregular scanning pattern, which arises the issue of degeneracy in indoor environments. To this end, we propose an accurate, robust and real-time LiDAR-inertial SLAM method for solid-state LiDARs. Firstly, a novel feature extraction based on geometry and intensity is proposed, which is the core of handling with degeneracy. To make full use of extracted features, two multi-weighting functions are designed for planar and edge points respectively in the process of pose optimization. Lastly, a map management module using an image processing method is developed not only to keep time efficiency and space efficiency but also to reduce edge intensity outliers in line map. Qualitative and quantitative evaluations on public and recorded datasets show that the proposed method exhibits similar and even better accuracy with state-of-the-art SLAM methods in wellconstrained scenarios, while only the proposed method can survive in the robustness test towards degenerated indoor lab environment.

Adeno-Associated Viral Vector Immobilization and Local Delivery from Bare Metal Surfaces.

Spatially and temporally controlled delivery of biologicals, including gene vectors, represents an unmet need for regenerative medicine and gene therapy applications. Here we describe a method of reversible attachment of serotype 2 adeno-associated viral vectors (AAV2) to metal surfaces. This technique enables localized delivery of the vector to the target cell population in vitro and in vivo with the subsequent effective transduction of cells adjacent to the metal substrate. The underlying bioengineering approach employs coordination chemistry between the bisphosphonic groups of polyallylamine bisphosphonates and the metal atoms on the surface of metallic samples. Formation of a stable polybisphosphonate monolayer with plentiful allyl-derived amines allows for further chemical modification to consecutively append thiol-modified protein G, an anti-AAV2 antibody, and AAV2 particles. Herein we present a detailed protocols for the metal substrate modification, for the visualization of the metal surface-immobilized vector using direct and indirect fluorescent AAV2 labeling and scanning electron microscopy, for quantification of the surface-immobilized vector load with RT-PCR, and for the localized vector transduction in vitro and in vivo.

On-Orbit Spatial Quality Evaluation of SDGSAT-1 Thermal Infrared Spectrometer

The Sustainable Development Science Satellite (SDGSAT-1) was successfully launched on 5th November 2021. It is the world’s first scientific satellite dedicated to serving the United Nations 2030 Agenda for Sustainable Development. To evaluate the on-orbit image quality of its thermal infrared spectrometer (TIS), we propose an improved edge slope calculation method. Learning from past academic research, we found that the traditional edge slop (ES) calculation methods are limited by various factors. For example, it demands highly on geographical aspects and surface temperature uniformity. In this paper, we interpolate the narrow sea-land boundary region. The edge signal-to-noise ratio and dip angle are calculated by the selected region to determine whether it satisfies the conditions of ES calculation. The Otsu algorithm is used to find the optimal threshold for the sea-land division, and the sub-pixel edge positions are extracted by combining with the canny operator. In order to achieve higher precision, we use the modified Fermi function to fit the extracted edge spread function (ESF). During the on-orbit testing of the SDGSAT-1/TIS, we performed ES calculations for a large number of test areas with a flight direction of 0.5 and a scan direction of 0.45.

Oriented AFM Scanning on a Large Sample with Cooperative Rotating Stage and Auxiliary Optical Microscopy

Atomic force microscope (AFM) is a powerful tool capable of constructing accurate 3-D surface profiles at a nanometer resolution. However, the scanning area of the AFM is limited by the piezo-scanner. Hence, this will restrict the AFM from scanning those applications to large samples. Moreover, some features (e.g., strip shape) orientation relative to the AFM scanning direction is necessary to be considered. To address these issues, the AFM system combined with a rotation stage and a long-range stage is constructed. Besides, an automatic method to move the oriented scan region into the AFM workspace is provided through the assistance of an optical microscope (OM). Finally, the result shows that the AFM scanning on large samples is achievable.

Lossless Compression of Bilevel ROI Maps of Hyperspectral Images Using Optimization Algorithms

In this letter, we propose a novel scheme for the compression of the bilevel region of interest (ROI) maps of hyperspectral images. The scheme can achieve high compression ratios by novel ways of partitioning the intricate regions of the image into smaller blocks. We first analyzed the effect of a low-order linear predictive model on the original image. The analysis showed that linear prediction results in lower-entropy residual images compared to the original images, which in turn helps in improving the compression efficiency. We then use the optimization algorithm that finds the best combination of scan directions for the nonzero blocks. It is shown to offer increasingly better compression with additional iterations. The simulation results on various data sets show that our scheme outperforms the international standard for binary image compression [joint bi-level image expert (JBIG2)].

Novel poly(diaquabis(1,10-phenanthroline)copper(II)chloride) modified glassy carbon electrode for square wave voltammetric determination of aspirin in tablet samples

In this study, potentiodynamically fabricated poly (diaquabis(1,10-phenanthroline) copper(II)chloride) modified glassy carbon electrode (poly(A2P2CuC)/GCE) is reported for detection of aspirin in tablet samples. EIS and CV analysis of Fe(CN)6]3-/4- at the modified electrode revealed surface modification by an electroactive polymer material that improved electrode effective surface area and charge transfer resistance. An oxidative peak without a reductive peak in the reverse scan direction for aspirin at poly(A2P2CuC/GCE augmented by peak potential shift with scan rate showed the irreversibility of the electrochemical oxidation of ASA at the electrode. A better R2 (0.9983) for dependence of peak current on square root of scan rate than R2 (0.9612) on scan rate indicated that oxidation of aspirin at poly(A2P2CuC)/GCE was predominantly diffusion mass transport controlled. Under optimized PBS pH (5.5), and square wave parameters, oxidative peak current response of poly(A2P2CuC)/GCE showed linear dependence on the concentration of aspirin in the range 1–200 ​μM with associated %RSD under 3.7% (n ​= ​3), limit of detection 0.039 ​μM, and limit of quantification and 0.13 ​μM. Spike recovery result in the range 96.5–100.5% with %RSD under 1.9% (n ​= ​3), and interference recovery in the range 97.2–103.4% in the presence of 50–200% of uric acid, ascorbic acid, and glucose as potential interferents validated the applicability of the developed method for determination of aspirin content in tablet samples. Detection of aspirin in the studied tablet samples in an amount 99.4–101.5% of their nominal values with %RSD under 2.6% using the present method showed the applicability of the method to control the aspirin content in tablet samples. The present method showed better performance over the previously reported methods for determination of aspirin in tablet samples making it an excellent candidate.

Enlisting Aero-algal Flora and Algal Allergens Using Fan Dust Sampling Method from Pune, Maharashtra

Algae in the atmosphere are one of the bio-components of the environment. Despite the fact that they may have a negative impact on human health, they are the least studied organism in the field of aerobiology. Airborne algae continue to be viable in the atmosphere in the form of spores and filaments. In order to investigate the intramural diversity of airborne algae in Pune, eight residences were chosen, from which 16 fan dust samples were collected over a ten-day period. Total (108) aero-algal forms were recorded. Out of which 107 were Cyanophyta, and only one was Chlorophyta. The dominance of Cyanophyta members is attributed to the presence of a thick mucilaginous sheath around them, which allows them to tolerate the dryness. Overall, filamentous cyanophytes (71) outnumber coccoid cyanophytes (36). However, both fan dust slide samples and culture slide samples show variance. Coccoid cyanophytes (53) outnumber filamentous cyanophytes (11) in direct slide scans, although filamentous cyanophytes (25) were somewhat more numerous in culture samples than coccoid Cyanophyta (19). This increase in filamentous forms might be because of hormogonia of filamentous algae, which remained unidentified in direct slide scan and upon inoculation underwent reproduction increasing number of filamentous algae in culture slides. Chrooccocus, Gloeocapsa, Lyngbya, Nostoc, and Stigonema were among the forms found on the first and tenth days of fan dust sampling, indicating that they were a common inhabitant of fan dust during the study and that the fan, as an aero sampler, was able to capture them, demonstrating its potency as an aero sampler. Soil can be a substantial factor in the creation of fan dust, as these genera were frequently separated from the soil. Gloeocapsa, Phormidium, Lyngbya, Schizothrix, Cylindrospermum, Nostoc, Anabaena, Scytonema, Calothrix, and Scenedesmus were among the allergic aero-algal genera discovered during the investigation.

The detective quantum efficiency of cadmium telluride photon-counting x-ray detectors in breast imaging applications.

In breast imaging applications, cadmium telluride (CdTe) photon counting x-ray detectors (PCDs) may reduce radiation dose and enable single-shot multi-energy x-ray imaging. The purpose of this work is to determine the upper limits of the detective quantum efficiency (DQE) of CdTe PCDs for x-ray mammography and to compare them with the published DQEs of energy-integrating detectors (EIDs) and other PCDs. We calibrated and validated a Monte Carlo (MC) model of the DQE of CdTe PCDs using an XCounter CdTe PCD. Our model accounted for charge sharing, electronic noise, and charge summation logic. We used a 28 kVp Mo/Mo spectrum hardened by 3.9cm of Lucite to optimize the detector thickness and energy threshold for pixel sizes of 50, 85, and 100 m with and without inter-pixel charge summation logic. The figure of merit used for optimization was the integral of the DQE, which is equivalent to the detectability index for a delta function task function, which represents a high-frequency task. For an electronic noise level equal to that of the XCounter, the optimal DQE(0) without charge summing was 0.74. Charge summing for charge-sharing correction reduced DQE(0) by 14% due to an increase in electronic noise. Reducing the electronic noise to ∼0.5keV per pixel in combination with charge summing resulted in DQE(0) 0.78 for 85 m pixels, which is approximately equal to that of a-Se and slot-scanning silicon-strip PCDs. At higher spatial frequencies, and for matched pixel sizes, the DQE was inferior to that of a-Se EIDs and superior to that of slot-scanning silicon-strip PCDs in the scan direction but inferior in the slit direction. (1) CdTe PCDs have the potential to provide a zero-frequency DQE equal to that of a-Se EIDs and slot-scanning silicon-strip PCDs, but this will require electronic noise levels ∼0.5keV per pixel. (2) At mid-to-high spatial frequencies the DQE of CdTe PCDs may be (a) inferior to that of a-Se EIDs and slot-scanning silicon-strip PCDs in the slit direction, and (b) superior to slot-scanning silicon-strip PCDs in the scan direction.

A Study on the Mechanical Properties of an Automobile Part Additively Printed through Periodic Layer Rotation Strategies.

In metal product manufacturing, additive manufacturing (AM) is a method that has the advantage of fabricating complex shapes and customized production, unlike existing machining methods. However, owing to the characteristics of the AM process, anisotropy of macrostructure occurs because of various causes such as the scan direction, melting, fusion, and cooling of the powdered material. The macrostructure anisotropy is realized from the scan direction, and when a single layer is stacked in one direction, it is expressed as orthogonal anisotropy. Here, the classical lamination theory is applied to simply calculate the individual orthotropic layers by superimposing them. Through this, the authors analyzed whether the mechanical properties of the product are isotropically expressed with a periodic layer rotation strategy. To determine if the mechanical properties can be reasonably considered to be isotropic, a shock absorber mount for a vehicle was manufactured by AM. The tensile and vibration test performed on the product was compared with the finite element analysis and experimental results. As a result of the comparison, it was confirmed that the macroscopically of the product was considered isotropic as the load-displacement diagram and the fracture location coincided, as well as the natural frequency and mode shape.

Sectorization of Macromolecular Single Crystals Unveiled by Probing Shear Anisotropy.

Polymer single crystals continue to infiltrate emerging technologies such as flexible organic field-effect transistors because of their excellent translational symmetry and chemical purity. However, owing to the methodological challenges, direct imaging of the polymer chains folding direction resulting in sectorization of single crystals has rarely been investigated. Herein, we directly image the sectorization of polymer single crystals through anisotropic elastic deformation on the surface of macromolecular single crystals. A variant of friction force microscopy, in which the scanning direction of the probe tip is parallel with the cantilever axis, allows for high contrast imaging of the sectorization in polymer single crystals. The lateral deflection of the cantilever resulting from shear forces transverse to the scan direction shows a close connection with the in-plane components of the elastic tensor of the polymer single crystals, which is of a fundamentally different origin than the friction forces. This allows for fast, facile, and nondestructive characterization of the microstructure and in-plane elastic anisotropy of compliant crystalline materials such as polymers.

Synthesizing high-resolution magnetic resonance imaging using parallel cycle-consistent generative adversarial networks for fast magnetic resonance imaging.

The common practice in acquiring the magnetic resonance (MR) images is to obtain two-dimensional (2D) slices at coarse locations while keeping the high in-plane resolution in order to ensure enough body coverage while shortening the MR scan time. The aim of this study is to propose a novel method to generate HR MR images from low-resolution MR images along the longitudinal direction. In order to address the difficulty of collecting paired low- and high-resolution MR images in clinical settings and to gain the advantage of parallel cycle consistent generative adversarial networks (CycleGANs) in synthesizing realistic medical images, we developed a parallel CycleGANs based method using a self-supervised strategy. The proposed workflow consists of two parallely trained CycleGANs to independently predict the HR MR images in the two planes along the directions that are orthogonal to the longitudinal MR scan direction. Then, the final synthetic HR MR images are generated by fusing the two predicted images. MR images, including T1-weighted (T1), contrast enhanced T1-weighted (T1CE), T2-weighted (T2), and T2 Fluid Attenuated Inversion Recovery (FLAIR), of the multimodal brain tumor segmentation challenge 2020 (BraTS2020) dataset were processed to evaluate the proposed workflow along the cranial-caudal (CC), lateral, and anterior-posterior directions. Institutional collected MR images were also processed for evaluation of the proposed method. The performance of the proposed method was investigated via both qualitative and quantitative evaluations. Metrics of normalized mean absolute error (NMAE), peak signal-to-noise ratio (PSNR), edge keeping index (EKI), structural similarity index measurement (SSIM), information fidelity criterion (IFC), and visual information fidelity in pixel domain (VIFP) were calculated. It is shown that the proposed method can generate HR MR images visually indistinguishable from the ground truth in the investigations on the BraTS2020 dataset. In addition, the intensity profiles, difference images and SSIM maps can also confirm the feasibility of the proposed method for synthesizing HR MR images. Quantitative evaluations on the BraTS2020 dataset shows that the calculated metrics of synthetic HR MR images can all be enhanced for the T1, T1CE, T2, and FLAIR images. The enhancements in the numerical metrics over the low-resolution and bi-cubic interpolated MR images, as well as those genearted with a comparative deep learning method, are statistically significant. Qualitative evaluation of the synthetic HR MR images of the clinical collected dataset could also confirm the feasibility of the proposed method. The proposed method is feasible to synthesize HR MR images using self-supervised parallel CycleGANs, which can be expected to shorten MR acquisition time in clinical practices.

Oxidation of capsaicin in acetonitrile in dry and wet conditions

• Water greatly affects the formal potential of capsaicin oxidation. • Two anodic processes were observed for capsaicin under dried conditions. • The second anodic processes shifted negatively with increasing water content. • Different numbers of electrons transferred under CV and CPE conditions. • Two to four electrons were transferred during the electrolysis of capsaicin. An electrochemical study of the phenol capsaicin (CAPH), the active ingredient in chilli pepper, was performed in dried and wet acetonitrile on a glassy carbon electrode. Under dried conditions, two oxidation peaks at ca. 0.7 vs. (Fc/Fc + )/V (labelled E 1 ) and 1.0 vs. (Fc/Fc + )/V (labelled E 2 ) and two reduction peaks at ca . 0.1 and −0.5 vs. (Fc/Fc + )/V when the scan direction was reversed were observed. Rotating disk electrode experiments indicated that the two oxidation processes occur by same number of electrons and it is proposed they occur in two one-electron steps. As water was added to the acetonitrile, hydrogen bonding interactions between the water and the phenolic groups led to the E 1 and E 2 potentials shifting progressively more negatively. The shift in E 2 as water was added was greater than the shift in E 1 , so that after the addition of approximately 0.2 M H 2 O, only one voltammetric wave was observed (labelled as E 1 ′) corresponding to a two-electron oxidation, that continued to shift more negatively as more water was added. Under very wet conditions ([H 2 O] > 1 M), only one chemically irreversible oxidation peak was observed ( E 1 ′) at ca . > 0.5 vs. (Fc/Fc + )/V with one reduction peak at ca . −0.1 vs. (Fc/Fc + )/V upon reversal of the scan direction. Controlled-potential electrolysis under wet conditions indicated a total of two-electrons per molecule were transferred with the overall mechanism interpreted as a −2e – /−H + oxidation, followed by a hydrolysis reaction and loss of a methoxy group to form a 1,2-benzoquinone moiety.