Switching Mechanism Research Articles

Comprehensive review of the monitoring and sensing system in slopes with a special focus on the mining sector.

The failure of slopes due to various natural processes or extensive mining activities is a common problem that has an adverse impact on the environment and may result in severe casualties. Despite taking all the geotechnical considerations for the safe design of slopes, there could be unpredictable slope failure because of unexpected weather, seismic activities, or involvement of unidentified geological structures. Thus, continuous monitoring, forecasting, and warning of slope failures are imperative to save lives and property from devastation. This study was conducted to review the various slope monitoring techniques and propose the best possible monitoring system. The conventional instruments used for slope monitoring are wired, involving the human presence. In contrast, the economic Wireless Sensor Networks (WSNs), being less complex, may be utilized for real-time slope monitoring from a distant place to provide early warning about an imminent failure. The proposed early warning monitoring system will consider the local site conditions and be able to obtain various kinds of data regarding the factors influencing slope stability. The monitoring system will be flexible and efficient enough to provide timely warnings with a much higher life time by utilizing energy-efficient ZigBee protocols for communication. A switching mechanism is also proposed to take advantage of network topologies like star and tree. During bad weather, star topology will provide data at a higher rate, and during good weather conditions, tree topology will provide data at a lower rate by letting some nodes go into sleep mode, thus decreasing power consumption.

Multilevel Resistive Switching Dynamics by Controlling Phase and Self-Assembled Nanochannels in HfO2.

A resistive switching device with precise control over the formation of conductive filaments (CF) holds immense potential for high-density memory arrays and atomic-scale in-memory computing architectures. While ion migration and electrochemical switching mechanisms are well understood, controlling the evolution of CF remains challenging for practical resistive random-access memory (RRAM) deployment. This study introduces a systematic approach to modulate oxygen vacancies (OV) in HfO2 films of Ag/HfO2/Pt-based RRAM devices by controlling the substrate temperature. At 300°C, the HfO2 film exhibits a dominant monoclinic phase with maximum OV concentration, which plays a key role in achieving optimal multilevel resistive switching behavior. Self-assembled nanochannels in the HfO2 films guide CF evolution, and the diffusion of Ag at inside these films suggests a synergistic interplay between OV and Ag⁺ ion migration for reseting the voltage-controlled resistive states. This approach addresses the endurance/retention trade-off with an impressive Ron/Roff ratio of ≈8000while demonstrating growth temperature-driven OV modulation as a tool for multi-bit data storage. These findings provide a blueprint for developing high-performance oxide-based RRAM devices and offer valuable insights into multilevel resistive switching mechanisms, paving the way for future low-power, high-density memory technologies.

Macromolecular crowding and bicarbonate enhance the hydrogen peroxide-induced inactivation of glyceraldehyde-3-phosphate dehydrogenase.

The active site Cys residue in glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is sensitive to oxidation by hydrogen peroxide (H2O2), with this resulting in enzyme inactivation. This re-routes the carbon flux from glycolysis to the pentose phosphate pathway favoring the formation of NADPH and synthetic intermediates required for antioxidant defense and repair systems. Consequently, GAPDH inactivation serves as a redox switch for metabolic adaptation under conditions of oxidative stress. However, there is a major knowledge gap as to how GAPDH is efficiently oxidized and inactivated, when the increase in intracellular H2O2 is modest, and there is a high concentration of alternative (non-signaling) thiols and efficient peroxide removing systems. We have therefore explored whether GAPDH inactivation is enhanced by two factors of in vivo relevance: macromolecular crowding, an inherent property of biological environments, and the presence of bicarbonate, an abundant biological buffer. Bicarbonate is already known to modulate H2O2 metabolism via formation of peroxymonocarbonate. GAPDH activity was assessed in experiments with low doses of H2O2 under both dilute and crowded conditions (induced by inert high molecular mass polymers and small molecules), in both the absence and presence of 25 mM sodium bicarbonate. H2O2-induced inactivation of GAPDH was observed to be significantly enhanced under macromolecular crowding conditions, with bicarbonate having an additional effect. These data strongly suggest that these two factors are of major importance in redox switch mechanisms involving GAPDH (and possibly other thiol-dependent systems) within the cellular environment.

Stacking selected polarization switching and phase transition in vdW ferroelectric α-In2Se3 junction devices

The structure and dynamics of ferroelectric domain walls are essential for polarization switching in ferroelectrics, which remains relatively unexplored in two-dimensional ferroelectric α-In2Se3. Interlayer interactions engineering via selecting the stacking order in two-dimensional materials allows modulation of ferroelectric properties. Here, we report stacking-dependent ferroelectric domain walls in 2H and 3R stacked α-In2Se3, elucidating the resistance switching mechanism in ferroelectric semiconductor-metal junction devices. In 3R α-In2Se3, the in-plane movement of out-of-plane ferroelectric domain walls yield a large hysteresis window. Conversely, 2H α-In2Se3 devices favor in-plane domain walls and out-of-plane domain wall motion, producing a small hysteresis window. High electric fields induce a ferro-paraelectric phase transition of In2Se3, where 3R In2Se3 reaches the transition through intralayer atomic gliding, while 2H In2Se3 undergoes a complex process comprising intralayer bond dissociation and interlayer bond reconstruction. Our findings demonstrate tunable ferroelectric properties via stacking configurations, offering an expanded dimension for material engineering in ferroelectric devices.

Analytical and Experimental Study on a Versatile Landing System with Shock Response Mechanism

This paper introduces a versatile, passive-landing system designed for various landing operations such as planetary exploration missions, emergency landings of unmanned aerial vehicles (UAVs), and so on. The system leverages energy and momentum exchange mechanisms, incorporating two spring units and a detachable flyaway component to ensure smooth and safe landings. Initially, the kinetic energy of the lander is converted into potential energy stored in the spring units. A switch mechanism then releases this stored energy, converting it back into kinetic energy and transferring momentum to the flyaway part. This process effectively suppresses rebound and reduces acceleration, ensuring a soft landing. A key advantage of this mechanism is its high robustness against variations in initial-fall height. The energy stored in the spring units adjusts according to the falling height, enhancing the system adaptability. The system performance is evaluated through one-dimensional simulations to assess rebound height and acceleration, and two-dimensional simulations to evaluate its ability to prevent tip-over. An experimental setup further validates the system-rebound suppression capability. Results from both simulations and experiments confirm the superior system performance in minimizing rebound, reducing acceleration, and preventing rotational motion during landing.

Na+-doped WO3 double-layer resistive switching device for biomimetic applications

We report on polycrystalline double-layer NaWO3 thin films in a two-terminal device configuration showing resistive switching (RS) based on the neuronal ion Na+ for biomimetic applications. A top NayWO3 layer functions as a Na+ reservoir, enabling fast Na+ ion intercalation into a bottom NaxWO3 layer with x < y, giving good resistance control for analog processing. Operando Raman measurements show Na+ activation under 0.5 V and the electrical characterization proves that the switching is linked to the motion of Na+. The switching mechanism is investigated thoroughly by studying different film layer combinations. The observed RS performance can be explained by the change of electron emission/hopping site energy levels upon Na+ intercalation. The presented devices based on biocompatible materials constitute a promising route towards an analog processing building block for emulating neuronal ion channels for emerging biomimetic and potentially biomedical applications, as well as for flexible electronics.

Fabrication of bilayer ITO/YZO/PMMA/Al memory devices with insight ternary switching mechanism

Fabrication of bilayer ITO/YZO/PMMA/Al memory devices with insight ternary switching mechanism

Sensor fault diagnosis in nonlinear stochastic systems: a hybrid system formulation

This paper introduces a novel Fault Diagnosis (FD) approach for nonlinear stochastic dynamic systems susceptible to multiple, potentially concurrent sensor faults. We formulate the FD problem as a hybrid state estimation problem. To achieve this, a vector of binary state variables is introduced to augment the continuous-valued state variables. These binary variables act as an on-off switching mechanism, providing a framework for independent reasoning about the presence or absence of each sensor fault. Leveraging this hybrid dynamic system formulation, encompassing both binary and continuous-valued states within a single Particle Filter (PF) framework, enables our approach to efficiently co-estimate fault modes alongside dynamic system states. This innovation ensures efficient diagnosis of multiple, potentially concurrent sensor faults while circumventing the need for the cumbersome bank of estimators characteristic of traditional Multiple Model (MM) approaches used for FD. The performance of the proposed algorithm in diagnosing multiple sensor faults is evaluated using a benchmark nonlinear system from the literature. The results demonstrably validate the algorithm's efficacy, solidifying its potential for practical sensor FD applications under conditions of single or multiple faults.

Partition behavior of bovine serum albumin on homogeneous liquid-liquid extraction with triton X-114 solution by complex formation with pyllogarol red-molybdate reagent

Abstract The present study was conducted to examine the homogeneous liquid-liquid extraction behavior of bovine serum albumin (BSA) using an aqueous solution of Triton X-114 (TX114). We found that the addition of pyrogallol-red molybdate (PR-Mo) to the solution induced the complete extraction of BSA into the TX114-rich phase, though the BSA and PR-Mo could not be extracted selectively into the TX114 phase. To determine the distribution mechanism, photometric titration and circular dichroic (CD) spectroscopy were performed. BSA formed a complex with PR-Mo at a molar ratio of 1:42 in pure water, which shifted to 1:21 in an aqueous solution of TX114, indicating the formation of a ternary BSA-PR-Mo-TX114 complex. The CD spectra revealed that α-helix BSA is dominant in pure water, whereas β-strand BSA is dominant in the presence of PR-Mo. In summary, the structural change induced in BSA by the formation of a ternary complex is a possible switching mechanism of the partitioning behavior in BSA.

Aromaticity‐Dependent Memristive Switching

AbstractIn recent years, memristors have drawn attention as non‐volatile memory devices for advanced computing engineering. The features of memristors, such as hysteresis, high resistance state to low resistance state ratio, retention time, etc., are determined by the material, structure of the device, the switching mechanism, and the kinetics resulting from the characteristics of the materials. Here, a resistive switching is proposed based on the aromaticity change of the material. A device has been built based on tetracyclone that undergoes the transition from an antiaromatic to an aromatic state upon applied potential. This phenomenon results in the presence of two distinguishable, and more importantly, stable resistive states of the memristor. On the basis of theoretical and experimental investigation, it is demonstrated that the working principle of the device depends on the redox change of the molecules. This study provides the foundation for a new kind of memristive switching mechanism: the formation of virtual conductivity paths. They can be a key to improving the performance of semiconductor memory devices in crucial factors such as stability, reversibility, and nonvolatility because these paths are related to electron delocalization and do not involve any significant structural changes in the device (e.g., diffusion).

Voltage-driven molecular switch of highly periodically N‒heterocyclic adlayer enabled deep cycled zinc metal battery

The instable Zn/electrolyte interface due to severe corrosion, especially at high utilization of Zn anode, strongly hindered the practical application of aqueous zinc metal battery. Herein, we report a voltage-driven molecular switch through a reversible transition of the nicotinic molecules between zwitterion and anion to enable deep cycled zinc metal battery. In light of in-situ Raman, the switching mechanism of nicotinic molecules in the electrical double layer is unveiled: during plating, nicotinic molecules switches to zwitterion mode (ON state) with periodical pyridine-ring-substrate adlayer while during stripping, shifts to anion mode with periodical carbonyl group-substrate adlayer (OFF state). The transition of NA molecules enables molecular flipping on the substrate due to the electrostatic force and in this way, in both ON and OFF state, the zinc anode is protected by the adlayer to avoid the zinc corrosion on the anode side. Furthermore, the OTF‒ decomposition is accompanied by the open ring reaction of N‒heterocyclic from nicotinic acid molecules to form highly elastic solid electrolyte interface layer. Benefiting from both the molecular switch function and solid electrolyte interface layer formation, the nicotinic molecules-based electrolyte enables practical zinc metal battery of high energy density (100 Wh/kgelectrode) for over 800 cycles with a cumulative capacity of 2.71 Ah cm−2 at practical condition of low N/P ratio of 2, and lean electrolyte of 10 μL mAh−1, representing the state-of-the-art performance. These findings highlight the utilization of molecular switch and its interfacial protection of the deep cycled zinc anode, and provide a new tactic for the development of high energy metal battery.

Fluorescent “On‐Off‐On” Probe for Cascade Detection of Ag(I) and Ascorbic Acid Using Folic Acid Protected Copper Nanoclusters

AbstractFolic acid (FA) protected copper nanoclusters (FA‐CuNCs, λex=350 nm, λem=445 nm) were synthesized and used as a fluorescent “on‐off‐on” probe for the cascade detection of Ag+ and ascorbic acid (AA). The fluorescence emission of FA‐CuNCs at 445 nm was quenched significantly by Ag+ due to the analyte‐induced aggregation followed by the formation of larger nanoparticles. However, when AA was added to the in‐situ generated Ag@FA‐CuNCs, the fluorescence emission of FA‐CuNCs was recovered at 445 nm because of the AA‐directed reduction of Ag+ to Ag0. The experimental conditions, such as pH, incubation time, and quencher Ag+ concentrations, were optimized to achieve improved sensitivity. The detection limit for Ag+ and AA was estimated as 37.1 nM and 0.27 μM with a linearity range of 2.49–22 μM and 4.71–81.53 μM, respectively. In real sample analysis, the recoveries of Ag+ ions in river water and AA in orange juice samples were found between 99–93 % and 97–94 % using the probes FA‐CuNCs and Ag@FA‐CuNCs, respectively. Overall, this work offers a viable method for the sequential detection of Ag+ and AA using FA‐CuNCs via a fluorescence “on‐off‐on” switch mechanism.

Design and simulation of a smart master switch system based on multi-input XOR logic gate

Mechanical switches have been the conventional way of controlling electrical energy in different electrical systems such as: lighting systems, socket systems, and circuit breakers, especially in domestic, hospital, and industrial applications. Mechanical switches often require physical access to control different electrical devices that are connected to the power sources. The work presented in this paper aimed at designing and simulating a multi-input based Exclusive-Or master switch system that remotely controls the lighting and socket systems using the wireless switching mechanisms of Global System for Mobile communication and Bluetooth. The system therefore limits physical interaction that require use of the single pole double throw and keypad mechanical switches that are however included to act as fall-back mechanism in control of electrical devices. Within the recommended electrical safety measures, the design can be streamlined and integrated to remotely control lighting systems and sockets alongside the conventional mechanical switches in the consumer control unit.

Single-Defect-Induced Peculiarities in Inverse Faraday-Based Switching of Superconducting Current-Carrying States near a Critical Temperature

The Inverse Faraday Effect (IFE) is a phenomenon that enables non-thermal magnetization in various types of materials through the interaction with circularly polarized light. This study investigates the impact of single defects on the ability of circularly polarized radiation to switch between distinct superconducting current states, when the magnetic flux through a superconducting ring equals half the quantum flux, Φ0/2. Using both analytical methods within the standard Ginzburg–Landau theory and numerical simulations based on the stochastic time-dependent Ginzburg–Landau approach, we demonstrate that while circularly polarized light can effectively switch between current-carrying superconducting states, the presence of a single defect significantly affects this switching mechanism. We establish critical temperature conditions above which the switching effect completely disappears, offering insights into the limitations imposed by a single defect on the dynamics of light-induced IFE-based magnetization in superconductors.

Bonferroni‐Type Tests for Return Predictability With Possibly Trending Predictors

ABSTRACTThe Bonferroni test is widely used in empirical studies investigating predictability in asset returns by strongly persistent and endogenous predictors. Its formulation, however, only allows for a constant mean in the predictor, seemingly at odds with many of the predictors used in practice. We establish the asymptotic size and local power properties of the test, and the corresponding Bonferroni ‐test, under a local‐to‐zero specification for a linear trend in the predictor, revealing that size and power depend on the magnitude of the trend for both. To rectify this, we develop with‐trend variants of the operational Bonferroni and tests. However, where a trend is not present in the predictor, we show that these tests lose (both finite sample and asymptotic local) power relative to the extant constant‐only versions of the tests. In practice, uncertainty will necessarily exist over whether a linear trend is genuinely present in the predictor or not. To deal with this, we also develop hybrid tests based on union‐of‐rejections and switching mechanisms to capitalise on the relative power advantages of the constant‐only tests when a trend is absent (or very weak) and the with‐trend tests otherwise. A further extension allows the use of a conventional ‐test where the predictor appears to be weakly persistent. We show that, overall, our recommended hybrid test can offer excellent size and power properties regardless of whether or not a linear trend is present in the predictor, or the predictor's degrees of persistence and endogeneity. An empirical application illustrates the practical relevance of our new approach.JEL Classifications: C22, C12, G14

Impact of the Prey Refuge Parameter in the Presence of Fear Effect on the Fuzzy Two-Prey–One Predator Model with Switching Effect

It has been thought of as a class of models where a generalist predator feeds on two distinct prey species. We wish to examine how prey refuge factors affect prey–predator models when fear effects are present. In order to achieve this, a two-prey–one predator model with prey refuge has been taken into consideration in the presence of the predator’s fear effect on two prey species. Both prey species engage in intra-specific competition. We enhance our model by including a switching mechanism in predation. In order to account for the inherent imperfection of environmental conditions, some parameters have been taken as fuzzy numbers. Analytical and numerical results on the system have been examined in fuzzy sense. The system’s positivity, boundedness, and permanence are examined. The system’s local and global stability analyses have been investigated. Hopf bifurcation analysis around the positive interior equilibrium point has been explored. The stability of the limit cycle of our suggested fuzzy system has been discussed. The system’s numerical simulations have been investigated with pertinent tables and graphical illustrations. When the prey refuge parameter and fear parameter exceed the critical value, the system experiences Hopf bifurcation at the positive interior equilibrium point.

Analyzing negative differential resistance and capacitive effects in SiOx-based resistive switching devices for security applications

In this work, we analyze the negative differential resistance and capacitive effects in SiOx-based resistive switching devices. The cause of the negative differential effect has been investigated through the study of the switching mechanism in the devices. It has been observed that there is a combination of trap-controlled space charge limited conduction and trap-assisted Poole-Frenkel effect in the devices. Trapping and de-trapping of injected electrons in the defects within the silica structure causes the negative differential resistance effect. This characteristic feature can be employed to design chaotic circuits for security applications. In addition, the high electric field developed in the device compared to the applied field during the change of bias voltage from ±5V–0V, results in a capacitor discharge-like effect. This work will be a step forward in achieving the global Sustainable Development Goal of Peace, Justice, and Strong Institutions (SDG 16).

Deciphering the Optical Switching Mechanism of CdSe/CdS QDs Luminescence by Diarylethene Molecular Photoswitches: A Stochastic Model Analysis

Deciphering the Optical Switching Mechanism of CdSe/CdS QDs Luminescence by Diarylethene Molecular Photoswitches: A Stochastic Model Analysis

A semiconducting supramolecular Co(II)-metallogel based resistive random access memory (RRAM) design with good endurance capabilities.

A highly efficient approach for synthesizing a supramolecular metallogel of Co(II) ions, denoted as CoA-TA, has been established under room temperature and atmospheric pressure conditions. This method employs the metal-coordinating organic ligand benzene-1,3,5-tricarboxylic acid as a low molecular weight gelator (LMWG) in DMF solvent. A comprehensive analysis of the mechanical properties of the resulting supramolecular Co(II)-metallogel was conducted through rheological investigation, considering angular frequency and thixotropic study. The hierarchical rocky network structure of the supramolecular Co(II)-metallogel was unveiled using field emission scanning electron microscopy (FESEM). Transmission electron microscopic (TEM) analysis showed rod-shaped structures via low-magnification high angle annular dark field (HAADF) bright field scanning transmission electron microscopic (STEM) imaging, while energy dispersive X-ray (EDX) elemental mapping confirmed its primary chemical constituents. The formation mechanism of the metallogel was examined via fourier transform infrared spectroscopy (FTIR) spectroscopy. The nature of the synthesized CoA-TA metallogel was affirmed through powder X-ray diffraction (PXRD) analysis. Furthermore, this study involved fabrication of Schottky diode structures in a metal-semiconductor-metal geometry based on cobalt(II) metallogel (CoA-TA), enabling observation of charge transport behavior. Remarkably, a resistive random access memory (RRAM) device utilizing cobalt(II) metallohydrogel (CoA-TA) demonstrated bipolar resistive switching at room temperature and under ambient conditions. The switching mechanism was investigated, revealing the formation and rupture of conductive filaments between metal electrodes that govern the resistive switching behavior. This RRAM device exhibited an impressive ON/OFF ratio (~ 414) and exceptional endurance over 5000 switching cycles. These structures offer great potential for diverse applications such as non-volatile memory design, neuromorphic computing, flexible electronics and optoelectronics. Their advantages lie in their fabrication process, reliable resistive switching behavior and overall performance stability.

Mechanisms for the Spin-State Switching of Strapped Ni-Porphyrin Complexes Deposited on Metal Surfaces: Insights from Quantum Chemical Calculations.

The incorporation of molecular switches on nanodevices requires both the intactness of the molecule once deposited on a substrate and the persistence of the reversible switching feature. Recently, the reversible spin-switching of strapped Ni(II)-porphyrin complexes deposited on Ag(111) surface is demonstrated with low-temperature scanning tunneling microscopy (STM). The spin transition is accompanied by the coordination change of the metal center, a phenomenon denominated in coordination-induced spin-state switching (CISSS). In this contribution, the spin switching of the deposited strapped Ni-porphyrin molecules using different quantum chemistry approaches is explored. This calculations inform about the geometry and electronic structure of the adsorbed molecules and the origin of the voltage-dependent switching promoted by the STM tip. Two different mechanisms are inspected to elucidate the key role of the tip, mainly the electron injection between the tip and the molecule and the differential stabilization of the two spin states by the applied electric field between the tip and the silver surface. This study puts in evidence the relevance of the pyridine ligand contained in the strap in the transport properties as in the CISSS process itself.