In this work, vacuum electron acceleration driven by a periodic chirped Hermite–Sinh–Gaussian (HSG) laser pulse is theoretically investigated, with particular emphasis on the influence of frequency chirp parameters and beam waist on relativistic energy gain. The study demonstrates that frequency chirping significantly modifies the phase evolution of the electromagnetic field, thereby improving phase synchronism between the electron and the accelerating field. In the unchirped case, energy saturation occurs at 3.38 GeV due to rapid electron–laser dephasing. Introduction of a positive chirp enhances phase matching and prolongs the effective interaction time, leading to systematic energy enhancement. The saturation energy increases from 3.84 GeV (α = 0.002) to 4.18 GeV (α = 0.005). Similarly, the chirp modulation constant Ω plays a crucial role in dynamic frequency compensation, increasing the maximum energy to 4.18 GeV for Ω = 0.002. Furthermore, the beam waist is found to strongly influence acceleration efficiency. Larger beam waists reduce transverse ponderomotive effects, extend the interaction length, and enhance longitudinal confinement, resulting in a monotonic rise in energy up to 5.26 GeV. The results establish chirp parameters and beam waist as effective control parameters for optimizing vacuum electron acceleration.
This paper present a unified theoretical framework connecting relativistic time dilation, time–state correlation, and quantum superposition. The physical state of an object is modeled as an objective, continuous time-series function s = f(t). In the unobserved regime, the proper timeline of an object is independent of the observer’s reference frame; during observation, relativistic time dilation induces a corresponding state dilation effect, and the observed value represents the projection of the intrinsic state onto the observer’s timeline. Under elementary observation, classical behavior corresponds to a one-to-one state mapping (1 ≤ n < 2), while quantum behavior arises from a many-to-one relation (n ≥ 2) accompanied by state superposition, probabilistic outcomes, and the loss of temporal order. This paper derive formal superposition-projection formulas for time and state and apply the framework to interpret the double-slit interference experiment. The observed randomness of photon detection originates from unit-time projective sampling rather than fundamental indeterminacy, while the photon maintains a deterministic intrinsic wave function along its proper timeline. This paper predict a stepwise increase in discrete observable states as particle velocity approaches critical relativistic thresholds, supporting a continuous transition from classical to quantum behavior. This framework establishes a consistent bridge between special relativity, classical mechanics, probability theory, and quantum mechanics.
This work presents a mixed-mode circuit analysis of a negative-capacitance heterostructure nanotube tunnel field-effect transistor (NC-HNT-TFET) using Silvaco ATLAS TCAD for analog-on-chip applications. The proposed device achieves a subthreshold swing (SS) of 20.2 mV/dec, a transconductance-to-current ratio (gm/ID) superior to that of a conventional Gate-All-Around (GAA) architecture, and a significantly higher intrinsic gain than MOSFET-based amplifiers, owing to enhanced drain resistance (ro). A complementary TFET common-source (CS) amplifier demonstrates a low-frequency voltage gain of 15 dB, a 3 dB and cutoff near 310 GHz, and two-pole system behaviour consistent with the extracted transfer function. The heterostructure employs a Ge/AlGaAs heterostructure with a HfO2 gate dielectric and a ferroelectric (FE) layer modelled using the Landau–Khalatnikov (LK) equation. Stability and non-hysteretic operation are confirmed through capacitance-matching analysis. The extracted RF figures of merit, cutoff frequency (fT) of 7.2 THz and maximum oscillation frequency (fmax) of 11.3 THz, are obtained by extrapolation of Y-parameter-based current-gain and unilateral-power-gain roll-offs, and are physically justified by the high tunnelling-enhanced gm and the ultra-thin ferroelectric capacitance. These results demonstrate strong potential for ultra-high-frequency analog front-end and system-on-chip integration.
Silver bismuth selenide thin films were prepared and examined to understand their structural, optical, compositional, electrical, and thermoelectric behavior. X-ray diffraction analysis verified the formation of a phase pure hexagonal structure with good crystallinity and preferred orientation. The scanning electron images reveal a dense and continuous film composed of uniformly distributed nanoscale crystallites, with sizes ranging approximately 18–25 nm. Optical characterization showed strong absorption across the visible to near-infrared spectral region, and the optical band gap determined from Tauc plots lies within a range favorable for optoelectronic and energy-conversion applications. Electrical transport measurements revealed temperature dependent semiconducting behavior. Thermoelectric investigations conducted over the temperature range of 300–525 K exhibited a negative Seebeck coefficient throughout, indicating n-type charge transport. The Seebeck coefficient increased from 80.46 μV K–1 at 300 K to 105.49 μV K–1 at 525 K. With increasing temperature, the carrier concentration rose from 1.1 × 1019 to 1.9 × 1019 cm–3, while the carrier mobility improved from 0.3 to 0.9 cm2 V–1 s–1. The enhancement in mobility is attributed to the weakening of grain-boundary potential barriers at elevated temperatures. The corresponding fill factor was 0.48, resulting in a photoelectrochemical conversion efficiency of approximately 1.02
This study focuses on the intricate design and comprehensive investigation of electrostatic properties, analog analysis, and linearity characteristics associated with various neutral biomolecules. These investigations were conducted under varying dielectric constants, utilizing a novel device designated as the Negative Capacitance Junctionless Gate-All-Around (NC-JL-GAA) MOSFET. To evaluate the device’s sensing behavior, the analysis incorporated several neutral biomolecules, including Deoxyribonucleic Acid (DNA), Amino-propyl-tri-ethoxysilane (APTES), Streptavidin, Biotin, and air. The sensitivity of the electrostatic characteristics was thoroughly examined to ascertain the extent of their responsiveness. The simulated results demonstrate that the Subthreshold Swing (SS), Drain-Induced Barrier Lowering (DIBL), and OFF-state current (IOFF) consistently exhibit optimal performance across all investigated conditions. Notably, DNA yielded the highest ON-current (ION) and ION/IOFF ratio, thereby highlighting its superior interaction with the channel potential. These simulations were performed using the ATLAS™ 3D device simulator (SILVACO), which was calibrated against a device previously reported by other research groups. For validation purposes, the electrical and sensing characteristics of the device were benchmarked against those of other reported FET-based biosensors.
An algorithm for automatic alignment of the absolute rotor position sensor of a brushless permanent-magnet synchronous motor with distributed windings is proposed and developed, which makes it possible to calculate and consider the initial positioning error angle from the values of the control action of the regulator of the direct-axis component Id of the stator current. A deviation of the control output of the Id regulator in a vector field-oriented control system from the known nominal value and/or a change in the rotor rotation direction makes it possible to judge the initial error in the installation angle of the absolute rotor position sensor. It is proposed to calculate the deviation of the regulator control output in order to determine and add an offset to the rotor position angle when transforming the components of the rotating reference frame into the two-phase stationary reference frame (inverse Park transformation). A model of the converter with the electric motor has been developed. The results of mathematical simulation and full-scale experiments are presented. The relationship describing the effect of the deviation of the absolute rotor position sensor on the direct-axis current component in a control system with a speed loop is derived. The results of the effect of the encoder angle error on the control output of the direct-axis current regulator are presented.
In this article a robust Guided Physics-Informed Neural Network (GPINNs) method is used for learning and predicting the nonlinear dynamic of variable-order fractional hyperchaotic mathematical model. Fractional orders are based on polynomial, trigonometric and hyperbolic function into the sigmoid function. This variable-order fractional hyperchaotic system has been solved with GPINNs scheme that integrates data-driven learning with physics-based constraints. Four distinct fractional-order scenarios are considered to capture a broad range of memory and hereditary effects, that are inherent in practical electronic circuits. These cases made comprehensive assessment of the ability of the model. Furthermore, the effectiveness of this approach is shown through detailed analyses of time-series evolution, phase-space projections, and training diagnostics for multiple control parameters. This framework also highlights the strong potential of GPINNs for modeling complex integer- and variable fractional-order hyperchaotic systems, with promising applications in electronic circuit design, secure communication, and advanced signal processing.
In this study, we synthesized and investigated the influence of dopant nature on copper oxide nanoparticles (NPs) for four compositions: undoped CuO, Ni-doped CuO (Cu0.95Ni0.05O), Mg-doped CuO (Cu0.95Mg0.05O), and (Ni,Mg) co-doped CuO (Cu0.90Ni0.05Mg0.05O), using the sol–gel method. Samples were characterized through various characterization techniques and by photocatalytic performance. X-ray diffraction (XRD) analysis confirmed single-phase monoclinic CuO structure. (Ni,Mg) co-doping significantly reduced the average crystallite size from 20.95 to 6.24 nm. Scanning electron microscopy (SEM) demonstrated that the incorporation of Ni and Mg affected the morphology of the CuO NPS. Fourier-transform infrared (FTIR) spectra confirm the formation of CuO NPs. Moreover, (Ni,Mg) co-doping generated a synergistic electronic effect, where Ni narrowed and Mg widened the band gap, yielding an optimized band structure, improved light absorption in both the visible and UV ranges. This tunability is advantageous for photocatalytic applications, as the broader spectral response improves light harvesting and, consequently, photocatalytic efficiency.
The present work suggests and examines a hetero-oxide, dual-metal, negative-capacitance, double-gate tunnel field-effect transistor (HDM-NC-DGTFET) to achieve improved electrostatic control, ON-state current, and analog/RF characteristics to low-power applications. The suggested architecture combines (i) dual metal gate work-function engineering (φ1 < φ2), (ii) hetero-gate dielectric arrangement, and (iii) a ferroelectric covering to produce negative capacitance voltage amplification. The low-work-function gate at the source-channel interface not only sharpens the band bending and increases band-to-band tunneling (BTBT) but also the high-work-function drain-side gate prevents ambipolar conduction by reinforcing the channel-drain barrier. Extensive 2D TCAD simulations with a non-local BTBT model show a great deal of improvement over the traditional single-metal HSM-NC-DGTFET. The proposed device is able to attain a 90
The mechanisms responsible for generation of Majorana zero modes in carbon nanotubes proximately represented by an s-wave superconductor and placed in a uniform axial magnetic field are theoretically and numerically analyzed. An effective 1D low-energy model is built on the basis of the Dirac description of electronic states of graphene taking into account the rolled-up structure geometry. It is shown that the quantization of transverse motion, the orbital contribution of a magnetic field (the Aharonov–Bohm effect), and the curvature-induced spin–orbit coupling jointly form a topologically nontrivial superconducting state. In the appropriate parametric mode, the effective Hamiltonian is reduced to a known 1D model with all its parameters expressed directly through the geometric characteristics of a nanotube and the value of an external magnetic field, without introducing phenomenological assumptions. The Majorana modes emerging at the nanotube edges are nonlocal quantum states protected by the superconducting gap, which makes them promising for implementing topological qubits. The analytical results are confirmed by the numerical simulation within the Bogoliubov–de Gennes Hamiltonian, which demonstrates the energy gap closing and reopening and the emergence of localized edge states.
Nickel oxide (NiO) nanograins were successfully synthesized through a green, eco-friendly route using jojoba oil as a natural precursor. This sustainable approach enables the formation of nanocrystalline NiO without relying on harsh chemicals or toxic solvents. XRD analysis confirmed the development of phase-pure NiO with characteristic reflections indexed to the (111), (200), (220), (311), and (222) planes of the C12/m1 space group, while a minor Ni(OH)2 phase was also detected. The average crystallite size, calculated from the Scherrer equation, was approximately 50 nm. SEM images revealed well-defined grains and clear grain boundaries, highlighting the polycrystalline nature of the product, whereas EDX spectra verified the presence of Ni and O along with trace elements such as Na, Cl, and C originating from the natural synthesis medium. Although electrical and dielectric measurements were conducted to probe charge-transport behavior, the primary significance of this work lies in demonstrating jojoba oil as an effective, sustainable, and low-impact precursor for producing high-quality NiO nanograins. This green synthesis pathway offers a promising alternative for the environmentally responsible fabrication of functional metal oxide nanomaterials.
The present work investigates the influence of indium incorporation on the structural and thermo-physical characteristics of In–Sb–Se chalcogenide glass systems, InxSb30Se70 – x (x = 0–25), using a theoretical framework. A set of composition-dependent parameters including average coordination number, bond energy, network constraints, heat of atomization, deviation from stoichiometry, and lone-pair electron concentration were evaluated to understand the evolution of network connectivity and thermal stability. The results indicate that increasing indium content leads to enhanced network rigidity, as reflected by higher coordination numbers, increased bond strength, and reduced structural disorder. The decrease in lone-pair electrons and deviation from stoichiometry suggests improved cross-linking within the glassy network, contributing to enhanced thermal stability. In addition, a simple machine-learning-based regression model was employed as a supplementary validation tool to examine correlations between selected structural parameters and the glass transition temperature (Tg). The close agreement between theoretical predictions and regression-based estimates confirms the consistency and robustness of the adopted approach. The present study provides a systematic theoretical understanding of composition-driven trends in In–Sb–Se chalcogenide glasses and offers useful guidance for tailoring their thermo-physical properties.
We present an irreversible completion of Einstein gravity as a controlled small-diamond approximation of a null-boundary ledger framework. The primitive input is protocol-level bookkeeping on a null screen patch: a context (𝒜,ω ) fixing modular comparisons, a geometric capacity 𝒳: = A/(4G_ren) in entropy units, and a nonnegative record ledger N_c counting logically irreversible register updates. A two-sheet carrier separates, within each update, the reference structure used to define increments from the record-bearing structure stabilized across updates, avoiding self-referential metric-increment ambiguities. Coarse-grained balance, together with the standard small-diamond modular-universality and covariant phase-space inputs, yields a local non-equilibrium screen law whose reversible sector recovers the Einstein equation. We clarify how ledger–CTP differs structurally from standard Schwinger–Keldysh, modified gravity, and stochastic gravity. We then propose two discriminator-style tests that directly target the ledger–CTP identification of record production with an irreducible imaginary influence phase: a gravitational Loschmidt-echo bound in atom interferometry and, within a stated linear/Gaussian completion class, a dissipation–noise consistency constraint linking any inferred non-GR propagation kernel to a correlated stochastic component in gravitational-wave data.
The impact of polarization-graded AlGaN back-barrier engineering on the DC and RF performance of InAlN/GaN HEMTs is systematically investigated. The study also investigates the influence of varying indium mole fraction (x) in the InxAl1 – xN barrier layer (x = 0.75–0.83). Compared to a uniform back-barrier structure, the graded back-barrier device demonstrates enhanced DC characteristics, delivering a higher drain current density of 0.73 A/mm vs. 0.66 A/mm at VGS = –3 V and VDS = 2 V. The graded structure also exhibits an improved peak transconductance of 0.61 S/mm, representing an 10
The rivers of the North Caucasus, particularly the Terek, experience significant anthropogenic loads of heavy metals (Pb, Cd, Zn), which accumulate in bottom sediments and, during flood periods, pose a risk of secondary pollution of floodplain agricultural lands. This paper presents a comparative analysis of the hydrological and sedimentological characteristics of the Terek and Yangtze rivers (Hunan Province, China). It is shown that both rivers exhibit similarities in three key parameters: a pronounced summer flood regime, the dominant role of fine suspended solids in pollutant transport, and the presence of anthropogenic sources of heavy metals (mining activities, industrial discharges). Based on the established similarities, the feasibility of adapting hybrid architectures with bidirectional long short-term memory networks and preliminary signal decomposition, which have been successfully tested on the Yangtze River, to predict Pb, Cd, and Zn concentrations in the Terek River was substantiated. The results of the study provide a scientific and methodological basis for subsequent calibration and verification of the model using our own field data, which it is planned to collect in 2026.
The current study investigates nonlinear second harmonic generation of q-Gaussian laser beam in cold quantum plasma. We considered combined action of relativistic and ponderomotive (RP) forces. The electron effective mass varies under combined action of RP forces thereby leading to variation in background plasma density across the beam’s path and causing the beam to self-focus. An electron plasma wave (EPW) is excited at laser’s original frequency due density gradients established in plasma. The nonlinear interaction of EPW with fundamental beam produces second harmonic generation (SHG). In order to explore this process, we have used standard approximations such as WKB approximation and paraxial theory to derive 2nd order ODE denoting the beam waist dynamics with dimensionless propagation distance and efficiency of 2nd harmonic generation. We also explored influence of different laser and plasma parameters on beam’s focusing behavior and the overall SHG efficiency.
In this paper, we have identified and studied five major geomagnetic storms whose disturbance storm time Dst < –100 nT was calculated and examined during Solar Cycle 24 and the ascending phase of Solar Cycle 25. There have been five geomagnetic storms found on March 17, 2015; December 20, 2015; September 8, 2017; August 26, 2018; and November 4, 2021, with Dst magnitudes of –234, –155, –124, –174, and –105, correspondingly. Correlation analysis of hourly plasma parameters and Kp indices (April 22–26, 2023) shows a strong relationship (Cr = 0.76) between the IMF B component and the Kp index. The solar and interplanetary parameters as well as their connection with the parameters of geomagnetic storms, have been studied in this paper. In this study, we found that coronal mass ejection is the principal cause of severe storms. It has been determined that there is a positive correlation between sunspot numbers and solar flux (F10.7), with a correlation coefficient of 0.95. The investigation aims to evaluate how the results might be applied practically to enhance forecast accuracy and mitigation strategies for safeguarding critical infrastructure, such as satellite operations, power grids, and communication networks, during geomagnetic storms.
Junctionless field effect transistors heavily rely on control gate engineering to perform. Dielectric material types, scaling of gate oxide, gate metal work, among others all choose the performance of the entire device. This paper simulates and analyses a graphene nanoribbon double gate junctionless tunnel field effect transistor (DG-JL GNR-TFET) using a non-quasi-static small-signal model to investigate its radio frequency properties. The control gate engineering effect, dielectric choice, and oxide scaling has been evaluated in detail with regard to device performance. The experiment shows that as the thickness of the oxide is increased, the efficiency of tunneling increases and the cut-off frequency (fT) reaches a maximum of 1.01 × 1012 Hz when the oxide thickness is 1nm thick. Electrostatic control is further enhanced by high-k dielectrics with TiO2 (2 nm) giving the best trade-off, with current ratio of 2.61 × 1012, subthreshold swing of 20.75 mV/dec, transconductance of 0.36 mS and gate capacitance of 0.065 fF at 1 V gate and drain voltages. Work function variation reveals an inverse dependence of frequency on work function, with the highest value (5.23 × 1011 Hz) obtained at 4.1 eV. Comparative benchmarking against reported tunnel field effect transistors highlights the superior switching ratio and steep subthreshold swing of the proposed device, confirming its potential for low-power, high-efficiency radio frequency front-end circuits and emerging Internet of Everything applications.
Experimental studies of the process of displacement of industrial oil with a viscosity of 55.2 and 88.3 mPa s from a homogeneous porous medium at pressures in the range of 8–14 MPa and temperatures of 313.333 and 353 K. It is shown that an increase in the dynamic viscosity of hydrocarbons leads to a decrease in the amount of displaced hydrocarbon from the porous medium. It has been suggested that the reduction in the amount of hydrocarbon displaced is due to the low solubility of carbon dioxide in both of the tested hydrocarbons. The dynamic viscosity of industrial oil was calculated in the pressure range of 8–14 MPa on isotherms of 313, 333, and 353 K. It is shown that the dynamic viscosity at pressures of 12 and 14 MPa decreases by 100–150
This work is aimed to develop a technology for fabrication of high-temperature carbon–ceramic composite materials. The approach includes the following processing stages: the fabrication of filled carbon-fiber blanks, their subsequent carbonization, high-temperature heat treatment, and pyrolytic compaction. A distinctive feature of the technology is the impregnation of particles of refractory component precursors into the interlayer space, that ensures in situ synthesis and subsequent sintering of the ceramic component of the matrix during the carbonization and high-temperature heat treatment stages. This approach has been successfully tested in the fabrication of carbon–ceramic composites in the Cf/C system—carbides and borides of transition metals of IV (Hf, Ti) and V (Nb) groups. The results of gas-dynamic tests of samples of the resulting composites under the influence of high-speed, high-enthalpy flows of oxidizing gases are presented. It is noted that the number of functional layers and their thickness allow to regulate the magnitude of the thermal load by changing the rate of oxidation, ablation and the duration of each mode.
