Square Wave Research Articles

Protecting Infinite Data Streams from Wearable Devices with Local Differential Privacy Techniques

The real-time data collected by wearable devices enables personalized health management and supports public health monitoring. However, sharing these data with third-party organizations introduces significant privacy risks. As a result, protecting and securely sharing wearable device data has become a critical concern. This paper proposes a local differential privacy-preserving algorithm designed for continuous data streams generated by wearable devices. Initially, the data stream is sampled at key points to avoid prematurely exhausting the privacy budget. Then, an adaptive allocation of the privacy budget at these points enhances privacy protection for sensitive data. Additionally, the optimized square wave (SW) mechanism introduces perturbations to the sampled points. Afterward, the Kalman filter algorithm is applied to maintain data flow patterns and reduce prediction errors. Experimental validation using two real datasets demonstrates that, under comparable conditions, this approach provides higher data availability than existing privacy protection methods for continuous data streams.

First Voltammetric Determination of Karbutylate via Pencil Graphite, Glassy Carbon, and Boron-Doped Diamond Electrodes in Soil Sample

We investigated the electrochemical behavior of carbamate pesticide-type karbutylate (KB) with boron-doped diamond (BDD), glassy carbon (GC), and pencil graphite (PG) electrode, and analytical determination in real samples. Similar to organophosphate insecticides, carbamate pesticides are produced from carbamic acid and are extensively utilized in agriculture, gardens, and residences. Therefore, a rapid and simple detection of KB in real samples is important. Carbon-based electrodes are widely used in electroanalytical chemistry due to their rich surface chemistry, chemical inertness, broad potential window, low background current, and congruency for various demanding applications. Three different carbon-based electrodes were used. The effect of buffer solutions, scan rate, square wave (SWV), and differential pulse voltammetry parameters on the voltammetric response of KB was tested. The optimum working media for all three electrodes was determined as pH 2.00 phosphate buffer solution and voltammetric measurements were carried out in this media. Under optimum experimental conditions, linear calibration dependences for KB were obtained as 6.00 × 10−7–8.00 × 10−5 M, 4.00 × 10−7–8.00 × 10−5 M, and 8.00 × 10−8–8.00 × 10−5 M with a limit of detection of 2.18 × 10−7, 3.71 × 10−8 M, and 2.66 × 10−8 M by the BDD, GC, and PG electrodes, respectively, using SWV. As a result, sensitive determination of KB has been successfully performed using different carbon-based electrodes in real soil samples.

Task-dependent contribution to edge-based versus region-based texture perception

Texture segregation studies indicate that some types of textures are processed by edge-based and others by region-based mechanisms. However, studies employing nominally edge-based textures have found evidence for region-based processing mechanisms when the task was to detect rather than segregate the textures. Here we investigate directly whether the nature of the task determines if region-based or edge-based mechanisms are involved in texture perception. Stimuli consisted of randomly positioned Gabor micropattern texture arrays with five types of modulation: orientation modulation, orientation variance modulation, luminance modulation, contrast modulation and contrast variance modulation (CVM). There were four modulation frequencies: 0.1, 0.2, 0.4 and 0.8 cpd. Each modulation type was defined by three types of waveforms: sinewave (SN) with its smooth variations, square-wave (SQ) and cusp-wave (CS) with its sharp texture edges. The CS waveform was constructed by removing a sinewave from an equal amplitude square-wave. Participants performed two tasks: detection in which participants selected which of two stimuli contained the modulation and discrimination in which participants indicated which of two textures had a different modulation orientation. Our results indicate that threshold amplitudes in the detection task followed the ordering SQ < SN < CS across all spatial frequencies, consistent with detection being mediated by the overall energy in the stimulus and hence region based. With the discrimination task at low texture spatial frequencies and with CVM textures at all spatial frequencies the order was CS ≤ SQ with both < SN, consistent with being edge-based. We modeled the data by estimating the spatial frequency of a Difference of Gaussian filter that gave the largest peak amplitude response to the data. We found that the peak amplitude was lower for detection than discrimination across all texture types except for the CVM texture. We conclude that task requirements are critical to whether edges or regions underpin texture processing.

Elliptic-rogue waves and modulational instability in nonlinear soliton equations.

We present elliptic-rogue wave solutions for integrable nonlinear soliton equationsin rational form by elliptic functions. Unlike solutions generated on the plane wave background, these solutions depict rogue waves emerging on elliptic function backgrounds. By refining the modified squared wave function method in tandem with the Darboux-Bäcklund transformation, we establish a quantitative correspondence between elliptic-rogue waves and the modulational instability. This connection reveals that the modulational instability of elliptic function solutions triggers rational-form solutions displaying elliptic-rogue waves, whereas the modulational stability of elliptic function solutions results in the rational-form solutions exhibiting the elliptic solitons or elliptic breathers. Moreover, this approach enables the derivation of higher-order elliptic-rogue waves, offering a versatile framework for constructing elliptic-rogue waves and exploring modulational stability in other integrable equations.

Electro-dewatering performance of sewage sludge under interrupted pulsating voltage: A comparison between square shape and half-sine shape waveform

Electro-dewatering of sewage sludge with pulsating voltage was conducted under the two different wave shapes (square wave (SQW) and half-sine wave (HSW)) to investigate the influence of wave shape and duty cycle on sludge dewatering performance. The results indicated that, under the same average voltage, the moisture content of dewatered sludge with HSW was 10.3%–35.4% lower than that with SQW, suggesting the better dewatering performance of HSW. The optimal dewatering performance was achieved at duty cycle of 80% for SQW and 60% for SHW. The chemical oxygen demand of filtrate from HSW could be 13% higher than that from SQW, indicating the higher capacity of HSW in breaking sludge cells/floc structure. The applied voltage during electrochemical treatment promoted the hydrolysis of protein in filtrate, and the main components in the electro-dewatered filtrate were fulvic acid- and humic acid-like substances. The specific energy consumption for sludge electro-dewatering were 0.015–0.269 kWh/(kg removed water), and it was almost in linear relationship with duty cycle. By overall considering the energy consumption and electro-dewatering performance, the condition of 60% duty cycle with HSW was obviously better than other conditions, which provides a meaningful guidance for future application of sludge electro-dewatering technology with pulsating voltage.

AC-Modulated XPS Enables to Externally Control the Electrical Field Distributions on Metal Electrode/Ionic Liquid Devices.

X-Ray Photoelectron Spectroscopy (XPS) has been utilized to extract local electrical potential profiles by recording core-level binding energy shifts upon application of the AC [square-wave (SQW)] bias with different frequencies. An electrochemical system consisting of a coplanar capacitor with a polyethylene membrane (PEM) coated with the Ionic Liquid (IL) N,N-diethyl-N-methyl-N-(2-methoxyethyl) ammonium bis(trifluoromethanesulfonyl)imide (DEME-TFSI) as the electrolyte is investigated. Analyses are carried out in operando, such that XPS measurements are recorded simultaneously with current measurements. ILs have complex charging/discharging processes, in addition to the formation of Electrical Double Layers (EDL) at the interfaces, and certain properties of these processes can be captured using AC modulation within appropriate time windows of observation. Herein, we select two frequencies, namely, 10 kHz and 0.1 Hz, to separate effects of the fast polarization and slow migratory motions, respectively. Moreover, the local potential developments after adding two equivalent series resistors at three different physical positions of the device have been carefully evaluated from the binding energy shifts in the F 1s peak representing the anion of the IL. This circuit modification allows us to quantify the AC currents passing through the device, as well as the system's impedance, in addition to revealing the potential variations due the IR drops. The complex AC-modulated local XPS data recorded can also be faithfully reproduced using the unmodulated F 1s spectrum and by convoluting it with electrical circuit output provided by the LT-Spice software. The outcome of these efforts is a more realistic equivalent circuit model, which can be related to chemical/physical makeup of the electrochemical system. An important finding of this methodology emerges as the possibility to induce additional local electrical field developments within the device, the directions of which can be reversed controllably.

Breathers of Gerdjikov-Ivanov equation under background of elliptic function

As one specific type of local solutions of nonlinear evolution equation, the breathers have the characteristic of envelope oscillation structure. This kind of oscillation is periodic. According to the periodicity of the distribution and evolution directions, there are three kinds of breathers, namely, the Kuznetsov-Ma breather (KMB), the Akhmediev breather (AB), and the general breather (GB). In recent years, the propagation of envelope breathers under the periodic background has been observed in many nonlinear physical fields, including nonlinear optical fibers and hydrodynamics. It is believed that the breathers can arise due to the modulational instability of the periodic waves, and they demonstrate many rich physical properties and dynamic behaviors of interactions. Therefore, recently great attention has been paid to the breathers under the periodic background in nonlinear science. As an important integrable model, the Gerdjikov-Ivanov (GI) equation can be used to describe various nonlinear phenomena in many physical fields such as in the quantum field theory, weak nonlinear dispersive water wave, and nonlinear optics. It is very meaningful to solve various types of solutions of this model to describe the propagation of nonlinear waves. As far as we know, the breather solutions for the GI equation have not been given under the elliptic function background. In this study, firstly, elliptic function solutions of the GI equation are solved by the modified squared wave (MSW) function approach and the traveling wave transformation. Then, we obtain the basic solution of the Lax pair corresponding to the Jacobi elliptic function seed solution. Based on the elliptic function transformation formulas and the integral formulas, the potential function solution can be expressed in terms of the Weierstrass elliptic function. Secondly, by the once iterated Darboux transformation, three types of breather solutions under the elliptic function background are constructed including the GB, the KMB and the AB. In addition, we analyze the dynamic behaviors of these three kinds of breathers, and present their three-dimensional space-time structures. By the twice iterated Darboux transformation, under the dn-periodic background we exhibit three types of interactions between two breathers, i.e. a GB and a KMB, an AB and a KMB, and a GB and an AB. Finally, we also present three types of interactions between two breathers under the general periodic background.

Neurotransmitter Assay for In Vivo Nerve Signal Detection Using Bismuth Immobilized on a Carbon Nanotube Paste Electrode.

Voltammetric analysis of the neurotransmitter epinephrine (EP) was performed using bismuth immobilized on a carbon nanotube paste electrode (BCE), whose properties were compared with those of a carbon nanotube paste electrode (CE). BCE was found to be more efficient in detecting EP. The analytical parameters used were 0.3 V square-wave (SW) stripping voltammetric amplitude, 400 Hz frequency, -0.8 V initial potential, and 0.015 V increment potential. The optimized conditions were applied to an assay of a carp's front fin. A BCE was inserted into a carp's front fin muscle, and a stimulus was given every 50 s. This circuit is easy to use and does not require much analytical preparation time. The working electrode is miniscule, and its detection limit is very low. The in vivo muscle's chronoamperometric nerve currents were analyzed. These results have potential for applications in medical diagnostics, pharmaceuticals, interface controllers, and other fields.

Electrochemical sensor based on ZrO2/ionic liquid for ultrasensitive simultaneous determination of metoclopramide and paracetamol in biological fluids

A novel electrode, carbon paste electrode modified with a nanocomposite of zirconium dioxide nanoparticles and ionic liquid (ZrO2NP/IL/CPE), has been fabricated and used to determine both the paracetamol (PAR) and metoclopramide (MCP) mixture in bulk powder, pharmaceutical formulations, and biological fluids. Furthermore, it is the first reported method to determine the paracetamol in presence of its toxic impurities (i.e., p-aminophenol and p-chloroacetanilide) simultaneously. Square wave (SWV) and cyclic voltammetric (CV) techniques were used to investigate the effect of scan rate, concentration, and pH in order to optimize sensor’s response. The calibration curves were obtained in both low and wide concentration ranges from (0.1–200 nM) to (3.0–100.0 µM) for both drugs with limit of detection (LOD) as low as 28 and 29 pM and limit of quantification (LOQ) 93 and 97 pM for PAR and MCP, respectively. The proposed sensor was used to assess PAR, MCP, and paracetamol toxic impurities in human plasma, urine samples, and pharmaceutical formulations with satisfactory results showing a broad dynamic linear range from 100 pM to 100 µM with high sensitivity and good reproducibility.Graphical

Polymerase incorporation of fluorescein or rhodamine modified 2′-deoxyuridine-5′-triphosphates into double-stranded DNA for direct electrochemical detection

The 2′-deoxyuridine-5′-triphosphates modified with fluorescein (dUTP-Fl) or rhodamine (dUTP-Rh) were tested as bearers of electroactive labels and as proper substrates for polymerases used in polymerase chain reaction (PCR) and isothermal recombinase polymerase amplification (RPA) with the aim of electrochemical detection of double-stranded DNA (dsDNA) amplification products. For this purpose, electrochemical behavior of free fluorescein and rhodamine as well as the modified nucleotides, dUTP-Fl and dUTP-Rh, was studied by cyclic (CV) and square wave (SWV) voltammetry on carbon screen printed electrodes. Both free fluorescein and dUTP-Fl underwent a two-step oxidation at the peak potentials (Ep) of 0.6–0.7 V and 0.8–0.9 V (phosphate buffer, pH 7.4). The reduction peaks of fluorescein and dUTP-Fl were registered between –0.9 V and −1 V, but they did not depend on concentration. The free rhodamine and dUTP-Rh have demonstrated the well-defined oxidation peaks at 0.8–0.9 V. In addition, the distinct reduction peaks at Ep between –0.8 V and −0.9 V were registered for both rhodamine and dUTP-Rh. The dUTP-Fl and dUTP-Rh were further tested as substrates to incorporate an electroactive label into 210 or 206 base pair long dsDNA amplicons generated either by PCR or RPA. Among two dUTP derivatives tested, dUTP-Fl revealed significantly better compatibility with PCR and RPA, producing the full-size amplicons at 50–90% substitution of dTTP in the reaction mixture. In the PCR, the best compromise between amplicon output and labeling was achieved at the dUTP-Fl : dTTP and dUTP-Rh : dTTP molar ratios of 70% : 30% and 20% : 80% in the PCR mixture, respectively, allowing the direct electrochemical detection of amplicons at micromolar concentrations. Alongside with fluorescence DNA assays, the fluorescein and rhodamine modified dUTP appear as promising electroactive labels to develop direct electrochemical DNA assays for detecting PCR and RPA products.

Investigating the Effects of Cascading Accelerated Stress Tests (ASTs) on the Localized Electrochemical Performance Degradation in Polymer Electrolyte Fuel Cells (PEFCs)

With a recent shift in focus from light-duty to heavy-duty vehicle applications, the durability and performance targets for polymer electrolyte fuel cells (PEFCs) have become even more stringent and challenging to achieve; for example, a net power output of 2.5 kW/g-PGM (1.07 A/cm2 current density) at 0.7 V is required after 25,000 hour-equivalent accelerated stress test (AST) [1]. Generally, different ASTs are designed to evaluate Pt electrocatalyst and support durability; for example, a square-wave (SW) AST with H2/N2 between 0.6 V to 0.95 V vs. reversible hydrogen electrode (RHE) targets Pt catalyst and a separate triangular-wave (TW) AST with a higher potential range (1 – 1.5 V vs. RHE) assesses the durability of carbon-based supports [2]. Recently, many studies [3]–[7] have revealed the heterogeneous nature of cathode catalyst layer degradation under different ASTs. Fuel cell electric vehicles are typically subjected to an enormous number of load/unload and start/stop cycles during regular operation. Though there is a considerable body of literature discussing the isolated effects of load/unload and start/stop cycles on durability and performance, there is a dearth of studies exploring the effects of cascading load/unload and start/stop cycles, a scenario more relevant to actual automotive conditions. In the present study, a segmented cell along with ex-situ Pt particle size mapping (through micro-X-ray diffraction) is used to understand the effects of cascading a DoE square-wave AST (0.6 V to 0.95 V vs. RHE) and a triangular-wave (1 – 1.5 V vs. RHE) on the durability and performance of a PEFC.The membrane electrode assemblies (MEAs) are subjected to two cascade ASTs. The first one involves 15k cycles of SW AST followed by 2.5k cycles of TW AST (referred to as Pt-followed-by-carbon, PtfCC, AST) and the other one involves 2.5k cycles of TW AST followed by 15k cycles of SW AST (referred to as Carbon-followed-by-Pt, CCfPt, AST). Multiple in-situ and post-mortem ex-situ techniques are used to obtain particle size distribution and spatial degradation profiles. Preliminary results indicate that the performance losses at the end-of-life (EOL) depend on the cascade order; PtfCC AST leads to higher losses compared to CCfPt AST in wet polarization conditions. The local current distributions are also strongly impacted by the cascade order during the aging process. Figure 1 shows the polarization performance of the samples at the beginning, middle (following the first AST), and the end-of-life of cascade ASTs.

The development, validation, and optimization of a SWAdSV method for the simultaneous determination of epinephrine and uric acid in real samples using a poly(L-cysteine) modified SPCE sensor

This work demonstrates the development, optimization, and method validation of a square-wave adsorption stripping voltammetry (SWAdSV) method for the simultaneous determination of epinephrine (EP) and uric acid (UA) using a poly(L-cysteine) (pLC) film modified screen-printed carbon electrode (pLC-SPCE). The pLC film was deposited by the electropolymerization of L-cysteine (LC). The successful deposition of pLC was confirmed by time-of-flight secondary ion mass spectrometry. A comparison was made between a bare SPCE and a pLC-SPCE for the analysis of EP and UA. In order to improve the electroanalytical performance of the pLC-SPCE sensor, the parameters of the square-wave (SW) technique, such as amplitude, frequency, and potential step, as well as the pH of the 0.1 M PBS solution, the concentration of the LC, the number of cycles for electropolymerization, the deposition potential, and the deposition time, were optimized. Subsequently, the SWAdSV method was validated for the limit of detection (LOD), the limit of quantification (LOQ), the linear concentration range, accuracy, and precision. The method had a very low LOD and LOQ, i.e. 10.0 µg/L and 19.8 µg/L for both analytes, respectively. Two linear concentration ranges were obtained, i.e. from 49.0 µg/L to 326.1 µg/L and from 326.1 µg/L to 887.1 µg/L, for both analytes. The average recoveries and the relative standard deviations for both analytes were in a range from 94.4% to 108.4% (n = 6) and from 2.6% to 11.7% (n = 6), respectively, at the four EP and UA concentration levels tested. In addition, the effect of possible interferents, such as glucose, L-ascorbic acid, K+, Cl–, Ca2+, SO42–, Mg2+, NH4+, C2O42–, and urea on the SW signal of EP and UA, were investigated. However, none of these compounds significantly affected the performance of the electroanalytical method. Finally, the applicability of the pLC-SPCE sensor was successfully demonstrated for the analysis of a pharmaceutical sample (an EP auto–injector) and human urine, proving accurate and precise analysis using the developed sensor.

Multi-breather and high-order rogue waves for the quintic nonlinear Schrödinger equation on the elliptic function background

In this paper, we derive the multi-breather and higher-order rogue wave solutions of the quintic nonlinear Schrödinger (NLS) equation on the elliptic function background by using the Darboux transformation (DT) and the modified squared wave (MSW) function approach. Firstly, we construct the elliptic function solution and solve the corresponding associated Lax pair with the given elliptic function potential by the traveling wave transformation. Secondly, we use the theta functions to represent the elliptic function solution and the fundamental solution of the Lax pair. Thirdly, we present several types of breathers on the dn- and cn-periodic backgrounds including the general breather (GB), the Kuznetsov–Ma breather (KMB) and the Akhmediev breather (AB). In addition, we illustrate the nonlinear dynamics of the breathers on the effect of elliptic function background. Finally, at branch points for breather solutions we obtain the higher-order rogue wave solutions by using the generalized DT. By several examples, we provide the first-, second- and second second-order rogue waves on the elliptic function background. It is expected that our results are helpful to understand the dynamics of breathers and rogue waves on the periodic background in various physical systems with higher-order effects.

Multiwalled Carbon Nanotubes-Modified Metallic Electrode Prepared Using Chemical Vapor Deposition as Sequential Injection Analysis Detector for Determination of Ascorbic Acid.

A carbon nanotubes modified silver electrode (CNTs-Ag) was prepared via catalytic chemical vapor deposition and characterized. The morphology, crystallinity, elemental composition, and other quality parameters of the prepared electrode were investigated using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Raman techniques. The characterization results revealed the modification of the silver metal surface with CNTs of good characteristics. A sequential injection analysis (SIA) system was developed for studying the reaction of ascorbic acid with KIO3 using the prepared CNTs-Ag electrode. Electrodes were polarized with both direct current (DC) and periodic square wave (SW). Various experimental conditions affecting the differential electrolytic potentiometric (DEP) peak such as current density, SW bias value, and flow rate were appraised. Under the optimum conditions, good linear responses for ascorbic acid were obtained in the range of 60.0-850.0 µM for both types of polarization with detection limits of 14.0-19.0 µM. The results obtained showed that the periodic polarization method was more sensitive than DC polarization and the electrode response was faster. Ascorbic acid in pharmaceutical tablets was determined with satisfactory results using this method. The prepared CNTs-based electrode exhibited good performance for a long period of use. The method is simple, rapid, and inexpensive for routine analysis.

Modulation Engineering: Stimulation Design for Enhanced Kinetic Information from Modulation-Excitation Experiments on Catalytic Systems

Modulation excitation (ME) with phase-sensitive detection (PSD) is an emerging strategy to selectively characterize catalytic species that actively participate in a chemical reaction. The commonly applied square-wave (SW) modulations, however, contain a limited frequency content, impeding rigorous kinetic analysis of short-lived reaction intermediates through PSD analysis by considering higher-order harmonics. To overcome this bottleneck, a “modulation engineering” approach is designed, whereby stimulation shapes with a complementary frequency content are superposed onto a base modulation, thus subjecting the system to a more complex frequency pattern in a single experiment. Building on practical and mathematical considerations, this design scheme’s feasibility is demonstrated using a superposition of SW and rectangular wave stimulations, applied to H2/CO2 concentration modulation-excitation X-ray absorption spectroscopy of a Ni/MgFeAlO4 methane dry reforming (DRM) catalyst at the Fe and Ni K edge. Under redox conditions, PSD evidences Ni ↔ Ni2+ and Fe0 ↔ Fe2+ ↔ Fe3+ redox events, wherein Fe2+ ↔ Fe3+ transitions exhibit faster kinetics, adding insight into this material’s redox functionalities under DRM conditions. This approach is extendable to other ME-based characterization techniques and provides a general, time-efficient framework to expand the transient kinetic insights that can be obtained for catalytic systems through ME with PSD.

Kinetics and Mechanism of In(III) Ions Electroreduction on Cyclically Renewable Liquid Silver Amalgam Film Electrode: Significance of the Active Complexes of In(III)—Acetazolamide

The results of kinetic measurements revealed an accelerating effect of acetazolamide (ACT) on the multistep In(III) ions electroreduction in chlorates(VII) on a novel, cyclically renewable liquid silver amalgam film electrode (R-AgLAFE). The kinetic and thermodynamic parameters were determined by applying the DC polarography, square-wave (SWV) and cyclic voltammetry (CV), as well as electrochemical impedance spectroscopy (EIS). It was shown that ACT catalyzed the electrode reaction ("cap-pair" effect) by adsorbing on the surface of the R-AgLAFE electrode. The catalytic activity of ACT was explained as related to its ability to form active In(III)- acetazolamide complexes on the electrode surface, facilitating the electron transfer process. The active complexes constitute a substrate in the electroreduction process and their different structures and properties are responsible for differences in the catalytic activity. The determined values of the activation energy ΔH≠ point to the catalytic activity of ACT in the In(III) ions electroreduction process in chlorates(VII). Analysis of the standard entropy values ΔS0 confirm changes in the dynamics of the electrode process.

Multi-channel anion sensing behaviour of a Ru(II)-bipyridine complex based on benzothiazolyl pyrazole ligand: Experimental and implication of machine learning tools for data prediction

Multi-channel anion sensing characteristics of a Ru(II) complex of the form [(bpy)2Ru (Hpzbzth)](ClO4)2 (1) {bpy = 2,2′-bipyridine and Hpzbzth = 3,5-bis(benzthiazol-2-yl)pyrazole} has been carried out in this work and analyzed through multiple machine learning tools. The complex possesses one pyrazole NH proton in its outer sphere which upon interaction with specific anions yields considerable change in its photo-redox behaviours. The anion sensing aspect of the complex is systematically investigated in acetonitrile through absorption, steady state and time-resolved emission spectroscopy as well as by square-wave (SWV) voltammetry. In absence of anions, the complex displays emission and represents the “on-state”, while complete quenching of emission takes place in presence of basic anions and designates the “off-state” of the system. The initial state of the complex could also be restored upon addition of acid and the process is reversible. Essentially, the complex acts as anion- and acid-induced molecular switches. The absorption, emission and electrochemical outputs of the complex in presence of anions and acid are employed to mimic different types of Boolean and Fuzzy logic (FL) functions. Additionally, we implemented herein different deep learning tools such as artificial neural networks (ANNs) and adaptive neuro-fuzzy inference system (ANFIS) to envisage the full anion sensing aspects of the complex. The outcomes of the three models are compared and also tallied with the experimental results.

Synergistic Cu+/Cu0 on Cu2O-Cu interfaces for efficient and selective C2+ production in electrocatalytic CO2 conversion

The electrocatalytic CO2 reduction technology is expected to simultaneously alleviate increasing CO2 emissions and the depletion of fossil resources. However, it is still a big challenge to improve the selectivity toward valuable multi-carbon products in electrocatalytic CO2 reduction reaction. In this study, the synergistic role of Cu+ and Cu0 species in Cu2O-Cu interfaces is unravelled through density functional theory (DFT) calculations, in which the electrode surface exhibits low free energy of *COCO intermediate formation and H2O dissociation, which are beneficial to the high selectivity towards multi-carbon products, especially C2H4. Guided by these DFT results, an oxide-derived copper electrode activation strategy that builds the synergistic Cu+ and Cu0 on Cu2O-Cu interfaces is designed to boost the selectivity toward multi-carbon products. Interestingly, Cu2O cubes chosen as the pristine catalyst are activated via a square-wave (SW) potential treatment to form SW-Cu2O cubes that bear Cu+ and Cu0 species. The as-prepared SW-Cu2O cubes exhibit superior Faradaic efficiencies for C2H4 (60%) and C2+ products (75%) in an H-type cell, which are about 1.5 times that of the Cu2O cubes. This study demonstrates the synergistic Cu0 and Cu+ on Cu2O-Cu interfaces for improving the selectivity of a specific valuable multi-carbon product in electrocatalytic CO2 conversion.

Square-wave generation in vertical external-cavity Kerr-Gires-Tournois interferometers.

We study theoretically the mechanisms of square-wave (SW) formation in vertical external-cavity Kerr-Gires-Tournois interferometers in the presence of anti-resonant injection. We provide simple analytical approximations for their plateau intensities and for the conditions of their emergence. We demonstrate that SWs may appear via a homoclinic snaking scenario, leading to the formation of complex-shaped multistable SW solutions. The resulting SWs can host localized structures and robust bound states.

Trace assay of insulin in a pharmacy drug with a paste electrode.

This paper describes the development of a voltammetric assay of insulin using a DNA immobilized onto a carbon nanotube paste electrode (CNPE), the peak potential of which was 0.2V, vs. Ag/AgCl on the CNPE. The cyclic voltammetry (CV) and square-wave (SW) stripping voltammetry parameters of the optimized conditions were determined. Low analytical working ranges of 10-80 ugL-1 CV and 0.01-0.1 ngL-1 SW were attained. The precision of the insulin concentration of 0.01 ugL-1 was 0.14 (n = 15) RSD using the optimum conditions, in which the detection limit was 0.004 ngL-1 (6.9 × 10-12M) (S/N = 3) using only an accumulation time of 400s. The developed method was applied to determine insulin in a pharmacy drug from analytical-grade chemicals (from Aldrich).