Series Array Research Articles

Corrigendum to “Quantum sampling AC standard for electrical power metrology based on programmable Josephson junction series array” [Measurement 233 (2024) 114747

Corrigendum to “Quantum sampling AC standard for electrical power metrology based on programmable Josephson junction series array” [Measurement 233 (2024) 114747

Deep echo state network with projection-encoding for multi-step time series prediction

To fully utilize the advantage of reservoir computing in deep network modeling, a deep echo state network with projection-encoding (DEESN) is newly proposed for multi-step time series prediction in this paper. DEESN integrates multiple echo state network (ESN) modules and extreme learning machine (ELM) encoders in series arrays. Firstly, the kth ESN in DEESN learner is responsible for kth step ahead prediction. The forecast output and encoded reservoir states of the previous ESN module are concatenated with the input variable to form the new input signals for the next adjacent module. Therefore, the temporal dependency among future time steps can be learned, which contributes the performance improvement. Secondly, the ELM encoder is used to optimize the reservoir states for time consumption reduction. Finally, the effectiveness of DEESN is evaluated in artificial chaos benchmarks and real-world applications. Experimental results on six different datasets and comparative models demonstrate that the proposed DEESN has excellent accuracy and robust generalization for multi-step time series prediction.

Development model of a high-performance multiple input multiple output microstrip antenna based on a planar series array with 8×2 elements for 5G communication systems

MIMO (Multiple Input Multiple Output) makes a major contribution to 5G communication systems by increasing network capacity and spectrum efficiency. In 5G, MIMO enables the use of multiple antennas at base stations and user devices, allowing simultaneous sending and receiving of data over multiple paths. This significantly increases data throughput and connection reliability, especially in environments with high user density. In addition, MIMO technology supports the implementation of beamforming, which focuses signals on a specific direction, reduces interference, and improves signal coverage and quality, making it one of the keys to achieving faster and more responsive 5G performance. Therefore, antennas with wide bandwidth, high gain and MIMO performance are crucial for supporting 5G communication systems. This paper proposes a high-performance MIMO microstrip antenna based on a series planar array with 8×2 elements operating at a resonant frequency of 3.5 GHz for 5G communication systems. A spiral stub and a feed inset are proposed to control the reflection coefficient and bandwidth of the antenna while the series planar array is proposed to increase the gain. To support the MIMO communication system, the proposed antenna is separated into two different ports with a certain distance. From the measurement results, the proposed antenna has high performance indicated by a wide bandwidth of 680 MHz (3–3.68 GHz) and a high gain of 17.8 dB at a resonant frequency of 3.5 GHz. In addition, the proposed antenna has high mutual coupling and diversity indicated by ECC and DG of 0.001 and 9.99 dB, respectively. This work provides a solution to design a high-performance microstrip antenna and can be implemented as a receiving antenna for 5G communication systems

Links between mutations in functionally separate arms of mitochondrial complex I and responses to volatile anesthetics.

Individuals with mitochondrial defects, especially those in Complex I of the electron transport chain, exhibit behavioral hypersensitivity and toxicity to volatile anesthetics. In Drosophila melanogaster, mutation of ND23 (NDUFS8 in mammals), which encodes a subunit of the matrix arm of Complex I, sensitizes flies to toxicity from isoflurane but not an equipotent dose of sevoflurane. Also, in ND23 flies, both anesthetics activate expression of stress response genes, but to different extents. Here, we investigated the generality of these findings by examining flies mutant for ND2 (ND2 in mammals), which encodes a subunit of the membrane arm of Complex I. The serial anesthesia array was used to expose ND2del1 and ND2360114 flies to precise doses of isoflurane, sevoflurane, and oxygen. Behavioral sensitivity was assessed by a climbing assay and toxicity by percent mortality within 24 h of exposure. Changes in expression were determined by qRT-PCR of RNA isolated from heads at 0.5 h after anesthetic exposure. Unlike ND2360114, ND2del1 did not affect behavioral sensitivity to isoflurane or sevoflurane. Furthermore, sevoflurane in hyperoxia as well as anoxia caused mortality of ND2del1 but not ND2360114 flies. Finally, the mutations had different effects on induction of stress response gene expression by the anesthetics. Mutations in different arms of Complex I resulted in different behavioral sensitivities and toxicities to isoflurane and sevoflurane, indicating that (i) the anesthetics have mechanisms of action that involve arms of Complex I to different extents and (ii) the lack of behavioral hypersensitivity does not preclude susceptibility to anesthetic toxicity.

Recoverability degradation of adhesion between soft matters under uniaxial cyclic bonding–debonding: Modified cohesive interface model and numerical implementation

The main objective of this work is to propose a partial recoverable cohesive interface model, coupled with a bi-potential contact algorithm, to simulate the phenomenon of adhesion recoverability degradation under cyclic bonding–debonding between hyperelastic bodies. For this end, the proposed adhesion recoverability degradation model is constructed by defining the recovery of interface damage during the rebonding when two bodies come into contact, and a degradation factor related to the number of bonding–debonding cycles is introduced into the fully recoverable adhesion model to reduce energy dissipation after multiple cycles. Recoverability degradation includes adhesive stiffness and strength degradation, which is physically described as parallel, series and mixed arrays of adhesive bonds. Then, a finite element framework coupling the adhesion recoverability degradation model and the bi-potential contact algorithm is proposed, with Mooney–Rivlin hyperelastic material used to describe the soft matters. This framework is implemented in an in-house finite element code, with numerical examples demonstrating the model’s reliability. The proposed approach could be applied to investigate interfacial adhesion effects in fields such as flexible electronics and intelligent robotics.

Logic Computing Field-Effect Transistors Based on a Monolayer WSe2 Homojunction for the Semi-adder and Decoder.

Two-dimensional reconfigurable field-effect transistors (FETs) are promising candidates for next-generation computing hardware. However, exploring the cascade design of FETs for logic computing remains challenging. Here, by using density functional theory combined with the nonequilibrium Green's function method, we design a 5 nm split-gate FET based on a monolayer WSe2 homojunction, which can implement dynamic polarity control in different gate configurations. The series array of two FETs shows a functional family of logic gates (NOR, AND, XOR, A̅B, and AB̅), and the semi-adder designed by the logic functions AND and XOR reduces the number of transistors by 66.7%. The parallel array of two FETs demonstrates reconfigurable logic gates with NAND/OR/A̅+B/A+B̅ quadruple functions, which can realize the decoding function of 00-11 in the decoder. The cascade design of the electrically tunable FETs helps to tackle the logic device downscaling and integration dilemmas.

Noise Scaling in SQUID Arrays

Abstract We numerically investigate the noise scaling in high-T_c commensurate 1D and 2D SQUID arrays. We show that the voltage noise spectral density in 1D arrays violates the scaling rule of ~1/N_p for the number N_p of Josephson junctions in parallel. In contrast, in 2D arrays with N_s 1D arrays in series, the voltage noise spectral density follows more closely the expected scaling behaviour of ~N_s/N_p. Additionally, we reveal how the flux and magnetic field rms noise spectral densities deviate from their expected ~(N_sN_p)^{-1/2} scaling and discuss their implications for designing low noise magnetometers.

Inspection of aluminum sheets using a multi-element eddy current sensor: 2d and 3d imaging of surface defects of various sizes and internal defects at various depths

In the industrial sector, ensuring reliability and durability is of paramount importance. Our research aims to advance beyond conventional non-destructive testing methods by focusing on thorough defect detection and imaging. We utilize advanced, sensor-enhanced eddy current testing, featuring multiple elements arranged in a cutting-edge serial array. This innovative configuration addresses the issue of magnetic repulsion between sensor elements, thereby speeding up the testing process and ensuring precise results through both 3D and 2D imaging. This sophisticated approach allows us to more effectively characterize defects of varying sizes and depths in aluminum sheets. By meticulously collecting and analyzing data from the sensors, we can identify the appearance and nature of these defects with greater clarity. Our findings introduce a pioneering method for defect detection, highlighting the efficacy of our advanced testing technique. Our research underscores the potential of multi-element eddy current sensors in revolutionizing the inspection process. The ability to produce detailed 3D and 2D images of surface and internal defects represents a significant leap forward in non-destructive testing. This comprehensive imaging capability not only accelerates the detection process but also enhances the accuracy and reliability of defect characterization. By employing this state-of-the-art technology, we can detect even the smallest and most deeply embedded defects that traditional methods might miss. The precise imaging provided by our approach ensures that defects of various sizes and depths are accurately identified and characterized. This level of detail is crucial for maintaining the structural integrity and performance of aluminum sheets used in industrial applications. Our research demonstrates a groundbreaking approach to defect detection in aluminum sheets, leveraging the advanced capabilities of multi-element eddy current sensors. The innovative use of a serial array of sensors, combined with sophisticated data analysis techniques, allows for rapid, accurate, and detailed imaging of defects. These findings pave the way for improved reliability and durability in industrial applications, setting a new standard for non-destructive testing.

Optimization of Thermoelectric Nanoantenna for Massive High-Output-Voltage Arrays.

Thermoelectric nanoantennas have been extensively investigated due to their ability to directly convert infrared (IR) radiation into direct current without an additional rectification device. In this study, we introduce a thermoelectric nanoantenna geometry for maximum output voltage (Voc) and propose an optimal series array configuration with a finite number of antennas to enhance the Voc. A finite and open-ended SiO2 substrate, with a thickness of a quarter-effective wavelength at a frequency of 28.3 THz, is used to generate standing waves within the substrate. An array of antennas is then positioned optimally on the substrate to maximize the temperature difference (∆T) between hot and cold areas, thereby increasing the average Voc per antenna element. In numerical simulations, a linearly polarized incident wave with a power density of 1.42 W/cm2 is applied to the structure. The results show that a single antenna with the optimum geometry on a substrate measuring 35 µm × 35 µm generates a ∆T of 64.89 mK, corresponding to a Voc of 1.75 µV. Finally, a series array of 5 × 6 thermoelectric nanoantennas on a 150 µm × 75 µm substrate including measurement pads achieves an average ∆T of 49.60 mK with a total Voc of 40.18 µV, resulting in an average Voc of 1.34 µV per antenna element and a voltage responsivity (βv) of 0.77 V/W. This value, achieved solely by optimizing the antenna geometry and open-ended substrate, matches or exceeds the Voc and βv of approximately 1 µV and 0.66 V/W, respectively, from suspended thermoelectric antenna arrays over air cavities. Therefore, the proposed thermoelectric nanoantenna array device, characterized by high stability and ease of fabrication, is suitable for manufacturing massive nanoantenna arrays for high-output IR-DC energy harvesters.

Circularly Polarized Series Array and MIMO Application for Sub-Millimeter Wave/Terahertz Band

This article presents a compact, planar, and circularly polarized array antenna operating in the W-band (84.5–110 GHz), with all its prototypes fabricated using a low-cost, traditional, microwave printed circuit board composed of Rogers RT/duroid 5880 (ε<sub>r</sub> = 2.2, tanδ = 0.009). The final design that was fabricated and measured was a 4 × 4 array antenna having an overall size of 9 mm × 20 mm × 0.254 mm that used series feeding to reduce its sidelobes. Measurements of the 4 × 4 patch antenna array showed approximately 6.9% 3-dB axial ratio bandwidth along with 15.2 dBi maximum right-hand circularly polarized (RHCP) antenna gain at 100 GHz. The array antenna yielded RHCP radiation characterized by a low profile, low cross-polarization levels (<−25 dB), low sidelobe levels (≤−10 dB), and high radiation efficiency (>91%). Additionally, a two-port MIMO antenna system was investigated by considering side-by-side and front-tofront configurations, both of which achieved good isolation and considerable envelope correlation coefficient and diversity gain values. Therefore, the proposed series array and MIMO antennas can be reasonable candidates for 6G applications of the sub-THz band (100– 110 GHz) in ultra-high-speed wireless and satellite communication systems.

Stock Sight

Stock Sight aspires to serve as a beacon of knowledge and insight, equipping stakeholders with a powerful forecasting tool capable of deciphering emerging market trends, predicting future stock prices, and optimizing investment strategies. By harnessing the latent potential of time series analysis, the project seeks to empower investors and financial professionals with the foresight and understanding necessary to navigate the dynamic and ever-evolving landscape of the stock market effectively. Through meticulous attention to detail and a commitment to excellence, "Stock Sight" emerges as an indispensable resource in the pursuit of financial success and prosperity. As "Stock Sight" progresses, it embarks on the development and evaluation of an array of sophisticated time series forecasting models, each meticulously tailored to discern and predict future stock prices with precision. Drawing upon methodologies such as Autoregressive Integrated Moving Average (ARIMA), Seasonal ARIMA (SARIMA), and Long Short-Term Memory (LSTM) networks, the project meticulously trains and optimizes these models using historical data. Through the rigorous application of robust evaluation metrics and comprehensive validation techniques such as cross-validation, "Stock Sight" meticulously assesses the effectiveness of each model, ensuring only the most reliable and accurate predictions are presented. Ultimately, "Stock Sight" aspires to serve as a beacon of knowledge and insight, equipping stakeholders with a powerful forecasting tool capable of deciphering emerging market trends, predicting future stock prices, and optimizing investment strategies. By harnessing the latent potential of time series analysis, the project seeks to empower investors and financial professionals with the foresight and understanding necessary to navigate the dynamic and ever-evolving landscape of the stock market effectively. Through meticulous attention to detail and a commitment to excellence, "Stock Sight" emerges as an indispensable resource in the pursuit of financial success and prosperity.

Arrays of nano-high-transition temperature superconductor quantum interference devices

We report the fabrication and testing of arrays of nanoscale superconducting quantum interference devices (SQUIDs) directly written into a thin film of the high-transition temperature superconductor YBa2Cu-3O7−δ with a focused helium ion beam. We compare three array configurations with 400 nm by 400 nm nanoSQUIDs connected in series and parallel and a two-dimensional (2D) combination of both. Our electrical transport measurements show that series arrays of three nanoSQUIDs exhibit modulation voltages greater than 1 mV and that combining the devices in parallel greatly enhances the slope of the voltage–magnetic field characteristic. A 2D array with 3 SQUIDS in series and 7 in parallel exhibited a transfer function of 5.51 mV/mT.

Multi-piezoelectric energy harvesters array based on wind-induced vibration: Design, simulation, and experimental evaluation

The efficiency of a single piezoelectric energy harvester (PEH) is inadequate to meet the energy requirements of equipment, requiring the simultaneous operation of multiple PEHs. Consequently, this work conducts research on multi-piezoelectric energy harvesters (MPEH) array based on wind-induced vibration. Analyze the output characteristics of array configurations using simulation and experimental methods, including dual parallel array (PEH-2p), dual series array (PEH-2s), four-square array (PEH-4), and nine-square array (PEH-9) energy harvesters. The results indicate that the spacing ratio (L/D) is the primary factor influencing the output performance of the PEH array. Both of the starting and peak wind speeds of PEH-2p were below the reference value, but the power peak has increased. The starting wind speed of PEH-2s has been reduced, with a more significant improvement in the output performance of the downstream energy harvester compared to the upstream energy harvester. The output power of the downstream energy harvester has increased by 323.35 % in comparison to the reference value. Additionally, the PEH-4 demonstrates a boosting effect on the output power of both the upstream and downstream energy harvesters. The energy harvester in the center of the PEH-9 has the highest power peak, being 349.44 % higher than the reference value.

Quantum sampling AC standard for electrical power metrology based on programmable Josephson junction series array

We report on the realization and preliminary validation of a quantum-based sampling power standard, based on a 1 V Programmable Josephson Voltage Standard (PJVS). The PJVS has been integrated into an existing sampling power standard along with a new synchronous multiplexer. Measurement scenarios for voltage and power measurements have been implemented and internally validated. Results of the measurement comparison against the Italian primary electrical power standard at 53Hz agree well within the respective uncertainties, and did not exceed 15μW/VA from 120V to 240V and 5A and any power factor. Likewise, measurements of alternating voltage up to a few kilohertz show good agreement when compared against AC/DC voltage transfer method. The article illustrates the quantum power standard and its main constituents, measurement scenario, comparison results and discussion, along with a preliminary estimation of the uncertainty budget.

Comparison of series and parallel reactance to identify changes in intracellular water in response to physical training in athletes during a sports season

Cross-sectional evidence has demonstrated that parallel reactance obtained by bioelectrical impedance analysis (BIA) may be an alternative to the regularly used series of measurements to predict intracellular water (ICW) in athletes. However, we are not aware of any studies that have determined the predictive role or compared the effectiveness of both series and parallel reactance for tracking ICW changes during an athletic season. The main aim of this study was to determine the predictive role and compare both series and parallel reactance (Xc) in tracking ICW during an athletic season. This longitudinal study analyzed 108 athletes in the preparatory and competitive periods. Using dilution techniques, total body water (TBW) and extracellular water (ECW) were determined and ICW was calculated. Resistance (R), Xc, and impedance (Z) standardized for height were obtained through BIA spectroscopy using a frequency of 50kHz in a series array and then mathematically transformed in a parallel array. Multiple regression analyses showed that only changes in parallel Xc and capacitance (CAP) (P < 0.05) were predictors of delta ICW during the sports season. In contracts, this was not the case for Xcs. Both changes in R and Z, series and parallel, predicted similarly the changes in ECW and TBW (P < 0.05) in athletes. Our findings highlight the potential of parallel BIA values to detect changes in body water compartments over a competitive season. These data provide preliminary evidence that changes in parallel Xc/H, and ultimately CAP, represent valid markers of alterations in cell volume during a sports season.

Passive communication for low power distributed sensors using MEMS optical cavities

Distributed sensing has been of great interest in recent research. Distributed sensors are in part defined by the methods they use to communicate. We demonstrate a new low power method of optical communication. Instead of communicating optically by generating new light to communicate using a light emitting diode or laser, our method uses optical interference to vary the reflectivity of a micro-electromechanical systems (MEMS) optical cavity. A thin air gap between an adjustable MEMS mirror made on a silicon on insulator die and glass encapsulation generates optical interference. By moving the mirror electrostatically, the reflected light intensity is modulated, and signals are transmitted passively. The transmitted signal is measured by observing the reflected light intensity with a photodiode. We demonstrate the use of fiber optic cables to deliver illumination and collect reflected light with modulated intensity. We propose that these devices may also be used in series arrays where reflected light from one optical cavity can be used as illumination for another.

Design and Optimization of High-gain Series and Parallel-fed Array Antennas for Enhanced Gain and Front-to-back Ratio in X-Band Applications

Design and Optimization of High-gain Series and Parallel-fed Array Antennas for Enhanced Gain and Front-to-back Ratio in X-Band Applications

Results of modeling different schemes of the spatial orientation and scanning series of base blocks of images to confront an unauthorized extraction of steganographic data

This work presents the results of modeling attempts at unauthorized extraction of steganocontent (halftone test images) under the condition of selective compromise of each of the two active processing parameters of the source array series of base blocks (BB) of content, i.e.: - the scheme scanning of BB series and the spatial processing of BB. The current program version ensures consistent realization of the main stages of content processing with the necessary settings parameters. As part of the modeling, it is suggested that the attacker has correctly identified one of the two current content processing parameters. Several modifications of the main schemes scanning of BB series and the spatial orientation of BB (rotation and horizontal mirroring) as an additional mechanism to counteract attempts of illegitimate content extraction are considered. The modeling was conducted on the examples of three types of images: - portrait, landscape, and mnemonic scheme. Manipulations with the spatial orientation parameter of BB strengthen the opportunities to counteract attempts at unauthorized data extraction. Characteristic quantitative and time histograms for different dimensions BB of content, changes in the peak of value signal-to-noise ratio for different types of schemes scanning BB series are presented, and samples of attacked test images are presented. The analysis and generalization of the main differences in the attack results using different parameters of the spatial processing of BB and ways of scanning series of BB of image-content are performed. Attention is drawn to the fact that the use of two active processing parameters of the source array of BB series is an effective and computationally «simple» means of counteracting attempts at unauthorized data extraction. The relationship between the stage of preprocessing the source content and the parameters of the formed arrays BB is emphasized. It is concluded that the introduction into the structure of the data extractor key, the elements of «The state of scanning» and «The spatial processing of BB», strengthens the overall capabilities to counteract attacks. The used processing parameters of the source array of BB series determine the structure of visual artifacts of attacked images but do not produce a simple solution to identify the attacked image at the level of classifying the type of source images. Prospective directions for further modeling of the main protection mechanisms within the proposed algorithm concept are indicated.

Performance Evaluation of Induction Motor Behaviour on Conventional and PV System Power Sources

The present study explores the integration of photovoltaic (PV) systems for enhancement of power system quality and reliability, particularly when PV system is deployed to power inductive loads which have wide applications in commercial and industrial settings. A mixed approach is deployed using MATLAB/Simulink for the modelling and simulation process. The study investigates the impact of inductive loads on PV system, comparing its performance with a conventional power source of same power willing capacity. The PV system was modelled by connecting PV arrays in series and parallel combinations. The output of the PV arrays was fed into a three phase PWM inverter, the harmonics present at the inverter output were eliminated using properly sized Inductor- capacitor (L-C) filter circuit. Also, a three-phase conventional source of same output capacity was modelled. Comparative analysis of the impacts inductive loads has on both sources were carried out and this was accomplished by integrating three-phase asynchronous motor rated at 15kW(20HP). The induction motors were independently powered by two distinct sources and further subjected to intermittent loading conditions. The major parameters investigated includes the rotor speed, rotor current, and electromagnetic torque of the asynchronous motor. The outcome of the study showed that the conventional source outperforms the PV system. These necessitates the studies on adoption of advance strategies on how the negative impacts and challenges encountered in the course of integrating PV system to power inductive loads will be address.

Lysozyme Inhibitors as Tools for Lysozyme Profiling: Identification and Antibacterial Function of Lysozymes in the Hemolymph of the Blue Mussel.

Lysozymes are universal components of the innate immune system of animals that kill bacteria by hydrolyzing their main cell wall polymer, peptidoglycan. Three main families of lysozyme have been identified, designated as chicken (c)-, goose (g)- and invertebrate (i)-type. In response, bacteria have evolved specific protein inhibitors against each of the three lysozyme families. In this study, we developed a serial array of three affinity matrices functionalized with a c-, g-, and i-type inhibitors for lysozyme typing, i.e., to detect and differentiate lysozymes in fluids or extracts from animals. The tool was validated on the blue mussel (Mytilus edulis), whose genome carries multiple putative i-, g-, and c-type lysozyme genes. Hemolymph plasma of the animals was found to contain both i- and g-type, but not c-type lysozyme. Furthermore, hemolymph survival of Aeromonas hydrophila and E. coli strains lacking or overproducing the i- type or g-type lysozyme inhibitor, respectively, was analyzed to study the role of the two lysozymes in innate immunity. The results demonstrated an active role for the g-type lysozyme in the innate immunity of the blue mussel, but failed to show a contribution by the i-type lysozyme. Lysozyme profiling using inhibitor-based affinity chromatography will be a useful novel tool for studying animal innate immunity.