Abstract: Time crystals are a class of non-equilibrium phases of motion characterized by spontaneous temporal symmetry breaking. We describe a time-crystal-inspired microdevice (TCIM) structured around a hexagonal shell encapsulating a central triangular motif. The geometry is derived from the Fukuta–Cerin theorem, where the centroid of each triangle aligns with that of the surrounding hexagon. In a TCIM flock, this leads to the emergence of controlled, oscillatory behaviour and symmetry-breaking phenomena driven by the internal geometry of the system. Indeed, the triangles introduce geometric frustration that allows the agents to maintain oscillations without relying on continuous external influence. The disruption of perfect synchronization enhances the flock’s ability to exhibit periodic, self-sustained oscillatory behaviour in response to minimal energy input or periodic perturbations, showcasing the system’s capacity for self-organization and dynamic patterns. Numerical simulations demonstrate that, under periodic driving, local alignment rules and structural frustration, the TCIM flock exhibits self-sustained subharmonic oscillations. These oscillations are characterized by a frequency shift to half the driving frequency, a key indicator of the emergence of time-crystal-like behaviour. This points towards the system’s ability to break discrete time-translation symmetry, another hallmark of time-crystal dynamics. TCIMs could enable the development of intelligent microdevices with internally regulated timing mechanisms like self-regulating sensors and synthetic bio-compatible materials that operate with minimal external control. TCIM-inspired devices, utilizing internal temporal rhythms, could also be applied in drug delivery systems, enabling the autonomous release of therapeutic agents in a timed, controlled manner without relying on continuous external inputs.

Abstract: Accurate wind speed prediction is crucial for managing wind power generation systems. However, the stochastic nature of wind complicates the estimation of optimal intervals. This work analyzes the performance of hybrid machine learning techniques for modeling wind speed. Two deep learning models, Large Language Memory Long Short-Term Memory and Large Language Memory Convolutional, are proposed, along with two hybrid models from the literature, Bidirectional LSTM and Convolutional LSTM, for four-season forecasting in the Bodele low-pressure area. Meteorological data come from the NASA Power/Dav site. Data processing includes removal of outliers and imputation of missing values by mean, median, or predictive models, performed with Python. The four hybrid models use the Adam algorithm to optimize predictions. The predicted values calculate wind turbine power, efficiency, and storage energy. Results show that performance indicators vary: MAE from 0.020 to 0.586, RMSE from 0.027 to 0.848, and R² from 0.902 to 0.966. Energy predictions for a 5 MW wind turbine range from 4.91 MWh in winter to 0.89 MWh in summer. The CL-LSTM and LLM-LSTM models give high wind speeds in summer and winter, providing insights for developing efficient models for similar applications, both for researchers and companies.

Abstract: External fields modify the confinement potential and electronic structure in a multiple quantum well system, affecting the light-matter interaction. Here, we present a theoretical study of the modulation of the nonlinear optical response simultaneously employing an intense non-resonant laser field and an electric field. Considering four occupied subbands, we focus on a GaAs/AlGaAs symmetric multiple quantum well system with five wells and six barriers. By solving the Schrödinger equation through the finite element method under the effective mass approximation, we determine the electronic structure and the nonlinear optical response using the density matrix formalism. The laser field dresses the confinement potential while the electric field breaks the inversion symmetry. The combined effect of both fields modifies the intersubband transition energies and the overlap of the wave functions. Our results demonstrate a dynamic and adjustable control of the nonlinear optical response, opening up the possibility of designing optoelectronic devices with tunable optical properties.

Abstract: People have always hoped to be able to fill an entire plane with 'single unit cells' without periodicity. This wish was realized after the mathematician discovered a 13-sided ``single cell'' named `einstein', we also refer to it as a hat tiling. These non-periodic tessellations generally exhibit anisotropic properties, making them superior in terms of mechanical performance compared to periodic structures, the application of non-periodic hat tiling in the study of honeycomb metamaterial structures. From the perspective of information entropy, the reason behind the improved mechanical properties of these structures is the higher entropy associated with non-periodic configurations. To quantify the disorder of non-periodic structures, we propose an entropy expression for the `einstein' metamaterial. To demonstrate the mechanical properties of these high-entropy structures, we fabricate specimens using 3D printing and conducte mechanical experiments. For comparative analysis, we also use ABAQUS to perform finite element analysis of the problem. The research results reveal that the mechanical properties of high-entropy structures created by the non-periodic stacking of cells are significantly improved compared to those of low-entropy structures created by periodic stacking. The conclusions drawn from the study of individual issues are generalizable and may be of assistance in future material and structural design.

Abstract: Nonlinear dynamical systems resist global analysis when approached through classical linearization techniques which rely on differential equations and local approximations. In seeking approaches to structurally reduce nonlinear dynamics to linear components, we propose interpreting the evolution of a nonlinear system as a sequence of non-commuting operations within a finite-dimensional associative algebra, where interaction rules are captured abstractly through algebraic composition rather than defined analytically. By embedding the nonlinear system into a semisimple algebra, we employ the Wedderburn–Artin decomposition to represent its dynamics as a direct sum of matrix algebras over division rings. Each matrix block defines a linear action on an irreducible subspace, corresponding to a dynamically invariant mode grounded in the system’s internal symmetries. This block structure reveals a modular architecture, demonstrating how nonlinear interactions can give rise to intrinsically linear behaviours governed by underlying algebraic principles. We apply our method to three distinct systems—symbolic rewriting systems, operator-driven vector dynamics and partially associative bitwise systems—selected to represent symbolic, quantitative and hybrid forms of nonlinearity. This range ensures that our decomposition framework effectively captures both regular and irregular compositional structures across diverse classes of nonlinear behaviour. We demonstrate that our method is able to isolate invariant subsystems and uncover underlying structure, by revealing the latent linear organization embedded within complex nonlinear behaviour. Overall, our framework extends matrix-based analysis into domains that are traditionally nonlinear, bridging symbolic computation, algebraic structure and dynamical behavior and providing an alternative approach to tackle nonlinear systems through their decomposable linear representations.

Abstract: The S-shaped dinaphtho[2,1-b:2′,1′-f] thieno[3,2-b]thiophene (S-DNTT) molecules have shown promise for applications in organic electronic devices, though their molecular characteristics are not yet fully understood. In this study, it firstly revealed the material characteristics of S-DNTT-10 by vibrational dynamics using Raman spectroscopy and density functional theory (DFT) simulations with employing B3LYP functional method and the 6-311G (d, p) basis set. The molecular vibrations identified include C-H bending in alkyl chains and deformation of S-shaped thiophene rings. Additionally, it suggested that surface-enhanced Raman scattering (SERS) with 785 nm incident light was applied to thermally deposited 25 nm S-DNTT-10 thin-films with gold (Au) nanostructures. It illustrated the enhancing Raman signals from the lower S-DNTT-10 layers. The findings significantly contribute to the knowledge of S-DNTT-10 molecular properties and using this material into organic electronic devices in the future.

Abstract: The intricate multi-scale phenomenon of entropy generation, resulting from the inhomogeneous and anisotropic rearrangement of cells during their collective migration, is examined across three distinct regimes: (i) convective, (ii) conductive (diffusion), and (iii) sub-diffusion. The collective movement of epithelial monolayers on substrate matrices induces the accumulation of mechanical stress within the cells, which subsequently influences cell packing density, velocity, and alignment. Variations in these physical parameters affect cell-cell interactions, which play a crucial role in the storage and dissipation of energy within multicellular systems. The internal dynamics of entropy generation, as a consequence of energy dissipation, are characterized in each regime using viscoelastic constitutive models and the surface properties at the cell-matrix biointerface. The focus of this theoretical review is to clarify how cells can modulate their rate of energy dissipation by altering cell-cell and cell-matrix adhesion interactions, undergoing changes in shape, and re-establishing polarity due to the contact inhibition of locomotion. We approach these questions by discussing physical aspects of these complex phenomena.

Abstract: 123 mobile phones in the 1.5 GHz-2.1 GHz frequency band are observed for electromagnetic radiation at two distances from the device (0m and 1m) and four distinct ways of usage. Electric field spectra are measured within a seven minute interval. Spectrum measurements minimum, aveage and maximum electric field (Emin,Eave,Emax) are reported.These values range from 0,021 V/m to 15,0 V/m.The Emax spectra peaks are non-systematic,depend on the provider and phone and range between 1,72 GHz and 1,97 GHz. The Emax measurements are compared via box and whiskers plots.The boxplot Q1-Q3 spectra measurements are compared via ANOVA.The measurements between Q1(25%) and Q3 (75 %) quartiles follow the normal distribution while the outliers are more, denser and with higher maximum Emax values at 0m distance (contact with ear) than at 1m away. Through reorganisation of the whole dataset in columns, the four usage ways are compared.Most significant is the usage way of making a call where only the corresponding columns follow the normal distribution.Making a call signifies the emitted electric field.

Abstract: The KSnI3 based perovskite solar cells have attracted a lot of research interest due their unique electronic, optical, and thermal properties. In this study, we optimized the performance of various lead-free perovskite solar cell structures—specifically, FTO/Al-ZnO/KSnI3/rGO/Se, FTO/LiTiO2/KSnI3/rGO/Se, FTO/ZnO/KSnI3/rGO/Se, and FTO/SnO2/KSnI3/rGO/Se, using the SCAPS-1D simulation tool. The optimization focused on the thicknesses and dopant densities of the rGO, KSnI3, Al-ZnO, LiTiO2, ZnO, and SnO2 layers, as well as the thickness of the FTO electrode. This, respectively, yielded the PCE values of 27.60%, 24.94%, 27.62%, and 30.44% for the FTO/Al-ZnO/KSnI3/rGO/Se, FTO/LiTiO2/KSnI3/rGO/Se, FTO/ZnO/KSnI3/rGO/Se, and FTO/SnO2/KSnI3/rGO/Se perovskite solar cell configurations. The FTO/SnO2/KSnI3/rGO/Se device is 7.66% more efficient than the FTO/SnO2/3C-SiC/KSnI3/NiO/C device, which is currently the highest performing KSnI3-based perovskite solar cell in the literature. Thus, our FTO/SnO2/KSnI3/rGO/Se perovskite solar cell structure is now, by far, the most efficient PSC design. Its best performance is achieved under ideal conditions of zero series resistance, shunt resistance of 107 Ω cm², and temperature of 371 K.

Abstract: Chlorophyll levels are a key indicator of plant nitrogen status, which plays a critical role in optimizing agricultural yields. This study evaluated the performance of three low-cost multi-spectral sensors, AS7262, AS7263, and AS7265x, for non-destructive chlorophyll measurement. Measurements were taken from a diverse set of five leaf types, including smooth, uniform leaves (banana and mango), textured leaves (jasmine and sugarcane), and narrow leaves (rice). Partial Least Squares regression models were used to fit sensor spectra to chlorophyll levels, using nested cross-validation to ensure robust model evaluation. Sensor performance was assessed using R2 and mean absolution error (MAE) scores. The AS7265x demonstrated the best performance on smooth, uniform leaves with R2 scores of 0.96-0.95. Its performance decreased for the other leaves, with R2 scores of 0.75-0.85. The AS7262 and AS7263 sensors, while slightly less accurate, achieved reasonable R2 scores ranging from 0.93 to 0.86 for smooth leaves, and 0.85 to 0.73 for the other leaves. All sensors, particularly the AS7265x, show potential for non-destructive chlorophyll measurement in agricultural applications. Their low cost and reasonable accuracy make them suitable for agricultural applications such as monitoring plant nitrogen levels.

Abstract:

The demand for computing power has been growing exponentially with the rise of artificial intelligence (AI), machine learning, and the Internet of Things (IoT). This growth requires unconventional computing primitives that prioritize energy efficiency, while also addressing the critical need for scalability. Neuromorphic computing, inspired by the biological brain, offers a transformative paradigm for addressing these challenges. This review paper provides an overview of advancements in 2D spintronics and device architectures designed for neuromorphic applications, with a focus on techniques such as spin-orbit torque, magnetic tunnel junctions, and skyrmions. Emerging van der Waals materials like CrI3, Fe3GaTe2, and graphene-based heterostructures have demonstrated unparalleled potential for integrating memory and logic at the atomic scale. This work highlights technologies with ultra-low energy consumption (0.14 fJ/operation), high switching speeds (sub-nanosecond), and scalability to sub-20 nm footprints. It covers key material innovations and the role of spintronic effects in enabling compact, energy-efficient neuromorphic systems, providing a foundation for advancing scalable, next-generation computing architectures.

Abstract:

The occurrence of chaotic instability of oscillations in a self-oscillating system of a generator with selected inertia in an underexcited mode under a quasi-periodic external action is considered. It is established that in a self-oscillating system, quasi-periodic excitation leads to the occurrence of chaotic oscillations. Two different cases of chaos occurrence are distinguished, differing in the arrangement of frequencies of the quasi-periodic external signal. The first case corresponds to a resonant action, when the frequencies of the quasi-periodic action are near the eigenmode of the system. The second case corresponds to a frequency distance of the quasi-periodic action comparable with the value of the inverse quality factor of the system. It is shown that in the first case, the chaotization of the forced oscillatory mode is associated with a sequence of oscillation trains with an arbitrary initial phase and duration. In the second case, the quasi-periodic action leads to the chaotization of the passive underexcited eigenmode of the system based on the intermittency of the forced oscillatory process.

Abstract: Extended short-wave infrared (eSWIR) detectors operating at high temperatures are widely utilized in planetary science. A high-performance eSWIR based on pBin InAs/GaSb/AlSb type-II superlattice (T2SL) grown on a GaSb substrate was demonstrated. It achieves the optimization of the device's optoelectronic performance by adjusting the p-type doping concentration in the AlAs₀.₁Sb₀.₉/GaSb barrier. Experimental and TCAD simulation results demonstrate that both the device's dark current and responsivity grow as the doping concentration riseing. Here, the bulk dark current density and bulk differential resistance area was extracted to calculate the bulk detectivity for evaluating the photoelectric performance of the device. When the barrier concentration is 1×1017 cm-3, the bulk detectivity is 2.1×1011 cm•Hz1/2/W, which is 256% higher than the concentration of 2×1018 cm-3. Moreover, at 300K (-10 mV), the 100% cutoff wavelength of the device is 1.9 μm, the dark current density is 9.48×10-6 A/cm2, and the peak specific detectivity is 7.59×1010 cm•Hz1/2/W (at 1.6 μm). The eSWIR detectors with low operating bias and low dark current density hold promise for being developed into high-performance imagers.

Abstract: In this paper, the impact of annealing at different temperatures (973 K, 1073 K and 1123 K for 1h) on the magnetic and microstructural properties of Mn-Fe-P-Si based glass-coated microwires is studied. Annealing significantly influences the magnetic and microstructural properties of Mn-Fe-P-Si glass-coated microwires. XRD analysis reveals that increasing the annealing temperature leads to a notable increase in the Fe₂P phase content, reaching a maximum at 1123 K, while simultaneously reducing the presence of secondary phases observed in the as-prepared sample. The reduction of secondary phases in Mn-Fe-P-Si -based microwires has a profound impact on their magnetic behavior. High coercivity values are observed in both the as-prepared and annealed samples,. However, annealing at higher temperatures (1073 K and 1123 K) results in a significant reduction in coercivity, decreasing from 1200 Oe for the sample annealed at 973 K to 300 Oe and 150 Oe, respectively. In addition, the sample annealed at 1123 K for 1h shows a notable paramagnetic behavior for loops measured from 200 K to 300 K. Meanwhile, the other samples show ferromagnetic behavior for all meas-uring temperature from 5 to 300 K. This study highlights the significant potential for tailoring and modifying various magnetic properties of Mn-Fe-P-Si glass-coated mi-crowires, including metamagnetic phase transitions, magnetic behavior, and the con-trol of magnetic response (hardness/softness). Such tailored properties make Mn-Fe-P-Si -glass-coated microwires promising candidates for a wide range of appli-cations.

Abstract: This study aims to determine the density of two hydrogel-based media, MAA and MAAG, which are suitable for both irradiation and bacterial growth, considering the presence or absence of Staphylococcus Aureus (SA) and Escherichia Coli (EC) strains. The viability of EC cells-inoculated systems was also evaluated to explore potential applications in radiation dosimetry within the 0-10 Gy range, using spectrophotometric and bacterial culture methods. Mass density measurements were performed at varying temperatures using two approaches: the first one, based on direct measurements of mass and volume, yielded densities comparable to liquid water, with uncertainties ranging from 9 to 16 %, while the second approach, employing Archimedes’ principle (mass in air vs. mass in a liquid of known density), produced more accurate results, with uncertainties between 0.04 and 0.08 %, thus the second method proved more reliable for density determinations. Furthermore, the feasibility study of EC-inoculated MAA and MAAG systems for ionizing radiation dosimetry demonstrated a linear spectrophotometric response to radiation doses across the investigated range, particularly for samples stored at 25°C. The studied systems were characterized in terms of the corresponding growth curve and post-irradiation bacterial survival, supporting their potentiality as reliable ionizing radiation dosimeters.

Abstract: In this work, we present a graphene-based photodetector specifically engineered to op-erate at a wavelength of 1310 nm. The device leverages the SPARK effect, previously investigated only at 1550 nm. It features a hybrid waveguide structure comprising hy-drogenated amorphous silicon, graphene, and crystalline silicon. Upon optical illumi-nation, defect states release charge carriers into the graphene layer, modulating the thermionic current across the graphene/crystalline silicon Schottky junction. The photo-detector demonstrates a peak responsivity of 0.3 A/W at 1310 nm, corresponding to a noise-equivalent power of 0.4 pW/Hz¹/². The experimental results provide deeper insights into the SPARK effect by enabling the determination of the efficiency × lifetime product of carriers at 1310 nm and its comparison with values previously reported at 1550 nm. The wavelength dependence of this product is analyzed and discussed. Additionally, the response times of the device are measured and evaluated. The silicon-based fabrication approach employed is versatile and does not rely on sub-micron lithography techniques. Notably, reducing the incident optical power en-hances the responsivity, making this photodetector highly suitable for power monitoring applications in integrated photonic circuits.

Abstract: The steady thermal model for conformal coating white LEDs is successfully developed to determine the temperature value in the package volume. The Matlab software (version 2017) and finite element method are utilized to solve the heat equation and visualize the temperature distribution, respectively. The thermal model is applied to study the temperature behavior of white LEDs under different injection currents of 50 mA, 150 mA, 250 mA, and 350 mA. The temperature value of each location is determined correspondingly by the temperature interpolation and comparing the color between color bar and color of the pcW-LEDs package structure. Beside, the effect of mesh size on the temperature simulation on the simulation result is also investigated. The result shows that the smaller mesh size provides higher resolution of temperature. The obtained result is meaningful for white LEDs thermal management to reduce the negative effect of heat during the operation process.

Abstract: Starting from earthquake fault dynamic equations, a correspondence between earthquake occurrence statistics in a seismic region before a major earthquake and the statistics of solutions to a nonlinear eigenvalue problem whose eigenfunctions characterize the seismic velocity model of the region is presented. Modelling the eigenvalue solution statistics with a 2D Coulomb gas statistical physics model, previously reported deviation of seismic activation earthquake occurence statistics from Gutenberg-Richter statistics in time intervals preceding a major earthquake is derived. It is also explained how statistical physics modelling predicts a finite dimensional nonlinear dynamic system describes rupture nucleation in the seismic activation region, and how this prediction can be tested experimentally.

Abstract:

We study quantum control of classical motion of a two-dimensional exciton by optimizing the time-dependent electric field of a stripe-like gate acting on the exciton and inducing its time-dependent quantum dipole moment. We propose a search method that significantly reduces computational requirements while efficiently identifying optimal control parameters. By leveraging this method, one can precisely manipulate the exciton’s final position and velocity over a specified evolution time. These results can be applied for control of exciton fluxes and population, and for spatially resolved light emission in two-dimensional semiconducting structures.

Abstract:

Asymmetry in the supply voltage in three-phase circuits disrupts the flow of currents. This worsens the efficiency of the distribution system and increases the problems in determining the mathematical model of the energy system. Among many power theories, the most accurate is the Currents' Physical Components (CPC) power theory, which tries to justify the physical essence of each component. Such knowledge can be used to improve efficiency and reduce transmission losses in the power system. The article discusses the method of mathematical decomposition of current components in the case of a three-wire line connecting an asymmetric power source with of linear time-invariant (LTI) loads. Special cases where irregularities appear in the results of calculations according to the CPC theory has been discussed. The method is illustrated with a numerical examples.