Search Results (1,049)

We experimentally observe harmonic oscillations in a bosonic condensate of exciton-polaritons confined within an elliptical trap. These oscillations arise from quantum beats between two size-quantized states of the condensate, split in energy due to the trap’s ellipticity. By precisely targeting specific spots inside the trap with nonresonant laser pulses, we control frequency, amplitude, and phase of these quantum beats. The condensate wave function dynamics is visualized on a streak camera and mapped to the Bloch sphere, demonstrating Hadamard and Pauli-Z operations. We conclude that a qubit based on a superposition of these two polariton states would exhibit a coherence time exceeding the lifetime of an individual exciton-polariton by at least two orders of magnitude. Full article

We investigate the phenomenon of quantum interference in spontaneous emission pathways for a quantum emitter embedded in a two-dimensional photonic crystal composed of a square lattice of dielectric cylindrical rods. Using a V-type three-level system as a model, we demonstrate that the anisotropic Purcell effect inherent in such photonic structures can amplify quantum interference to its theoretical maximum, where the degree of interference p reaches unity. This results in the complete suppression of spontaneous emission for one polarization (directional suppression) and the emergence of coherent population trapping without the need for external coherent fields. By employing density matrix formalism, we derive analytical expressions for the population dynamics and identify conditions for indefinite or long-lived excited-state population. Our findings can find application in quantum technologies, including high-precision atomic clocks, magnetometry, and quantum information processing. Full article

A mathematical model was established to describe the sublimation and diffusion of water molecules and their adsorption onto cold traps. This model was used to analyze the combined influence mechanisms of sublimation temperature and ambient pressure on the vapor deposition process of water ice. Tunable Diode Laser Absorption Spectroscopy (TDLAS) was employed to provide real-time feedback on water vapor concentration within the experimental apparatus. Based on this feedback, the sublimation temperature was dynamically adjusted to maintain the concentration dynamically stabilized around the target value. A dedicated apparatus for generating controlled water vapor flow fields and detecting concentration was constructed. The accuracy of both the mathematical model and Finite Element Analysis (FEA) simulations was verified through comparative experiments. Laser triangulation was utilized as a method to detect the thickness of the adsorbed ice film on the sample surface. Leveraging this technique, a water vapor deposition and adsorption verification system was developed. This system was used to test the differences in water adsorption performance across various materials and to measure the correlation between the thickness of the adsorbed/deposited ice film on the samples and both deposition time and sublimation temperature. Full article

The Global Cement and Concrete Association (GCCA) estimated that by 2050, 36% industry-wide sustainable value will be created, which includes sequestering CO₂ into the cement and concrete industry to produce commercially feasible high-value products. Direct utilization of CO₂ in the cement and concrete industry, which utilizes natural and sustainable materials, is gaining momentum. Naturally occurring mixtures of hydro magnesite and huntite are important industrial minerals which, upon endothermic decomposition over a specific temperature range, will release water and CO₂. This unique chemistry has led to such mixtures being successfully utilized as fire retardants, replacing aluminum hydroxide or Alumina Tri-Hydrate (ATH). Despite the developed marketplace for magnesium-based fire-retardant products, there is little mention of CO₂ mineral carbonation methods, which attempt to recover and convert magnesium from natural seawater or industrial waste into oxides or carbonates as part of the carbon sequestration initiative. The hypothesis to be proven in this work states that if the process of seawater mineral carbonation is prematurely quenched, Mg²⁺ ionic species in seawater adsorbed on the calcite lattice formation will be trapped and therefore recovered in various oxidized forms, such as magnesium oxides, magnesium hydro magnesite, and magnesium carbonate precipitates. A novel method to recover magnesium Mg²⁺ ions from seawater was successfully explored and documented; as such, from an initial concentration of 1250 ppm Mg²⁺ in raw seawater, the average concentration of spent Mg²⁺ ions after the reaction was as low as 20 ppm. A very efficient near-total recovery of Mg²⁺ from the seawater into the solid precipitates was recorded. Subsequently, the process for continuous seawater mineral carbonation for the production of magnesium/brucite/huntite products was successfully proven and optimized to operate with a 30 s reaction time, a dynamic feedstock concentration, [CaO] at 1 gpl in seawater and a room temperature reaction temperature (30 °C), where the average yield of the fire-retardant magnesium-based compounds was 26% of the synthesized precipitates. Approximately 5000 g of the hydro magnesite materials was molded into a fire-retardant brick or concrete wall, which was subjected to an accredited fire performance and durability testing procedure BS476-22:1987. There were encouraging results from the fire resistance testing, where the fire-retardant material passed BS476-22:1987, with performance criteria such as physical integrity failure, the maximum allowable face temperature, and a minimum duration before failure, which was up to 104 min, evaluated. Full article

Electromagnetically induced transparency (EIT) is well known as a quantum optical phenomenon that permits a normally opaque medium to become transparent due to the quantum interference between transition pathways. This work addresses multi-soliton dynamics in an EIT system modeled by the integrable Maxwell–Bloch (MB) equations for a three-level $\Lambda$-type atomic configuration. By employing a generalized gauge transformation, we systematically construct explicit N-soliton solutions from the corresponding Lax pair. Explicit forms of one-, two-, three-, and four-soliton solutions are derived and analyzed. The resulting pulse structures reveal various nonlinear phenomena, such as temporal asymmetry, energy trapping, and soliton interactions. They also highlight coherent propagation, elastic collisions, and partial storage of pulses, which have potential implications for the design of quantum memory, slow light, and photonic data transport in EIT media. In addition, the conservation of fundamental physical quantities, such as the excitation norm and Hamiltonian, is used to provide direct evidence of the integrability and stability of the constructed soliton solutions. Full article

The sine cosine algorithm (SCA) is a population-based stochastic optimization method that updates the position of each search agent using the oscillating properties of the sine and cosine functions to balance exploration and exploitation. While flexible and widely applied, the SCA often suffers from premature convergence and getting trapped in local optima due to weak exploration–exploitation balance. To overcome these issues, this study proposes a multi-faceted SCA (MFSCA) incorporating several improvements. The initial population is generated using dynamic opposition (DO) to increase diversity and global search capability. Chaotic logistic maps generate random coefficients to enhance exploration, while an elite-learning strategy allows agents to learn from multiple top-performing solutions. Adaptive parameters, including inertia weight, jumping rate, and local search strength, are applied to guide the search more effectively. In addition, Lévy flights and adaptive Gaussian local search with elitist selection strengthen exploration and exploitation, while reinitialization of stagnating agents maintains diversity. The developed MFSCA was tested against 23 benchmark optimization functions and assessed using the Wilcoxon rank-sum and Friedman rank tests. Results showed that MFSCA outperformed the original SCA and other variants. To further validate its applicability, this study developed a fuzzy c-means MFSCA-based adaptive neuro-fuzzy inference system to forecast energy consumption in student residences, using student apartments at a university in South Africa as a case study. The MFSCA-ANFIS achieved superior performance with respect to RMSE (1.9374), MAD (1.5483), MAE (1.5457), CVRMSE (42.8463), and SD (1.9373). These results highlight MFSCA’s effectiveness as a robust optimizer for both general optimization tasks and energy management applications. Full article

The conventional kinesin (kinesin-1) molecular motor is a prototypical member of the kinesin superfamily. It can processively step on microtubules toward the plus end by hydrolyzing ATP molecules, performing the biological function of shuttling cargos in cells. Its dynamics have been thoroughly studied using various methods including biochemical measurement, single molecule imaging, single molecule optical trapping, and so on. While most of the experiments yielded consistent results on the dynamics of the motor, a lot of conflicting experimental results have also been presented. Here, a brief review is given of the diverse conflicting experimental results. Furthermore, a model for the chemomechanical coupling of the motor is briefly reviewed, which can consistently and quantitatively explain these conflicting experimental results in addition to the other experimental results. A consistent explanation of the diverse conflicting experimental results with the same model is an essential criterion for determining the correctness of the model. Full article

This study reports the development of a fiber-optic localized surface plasmon resonance (FO-LSPR) sensor incorporating a three-dimensional micropillar array functionalized with gold nanoparticles. The micropillar structures were fabricated on the fiber facet using a single-mask imprint lithography process, followed by nanoparticle immobilization to create a composite plasmonic surface. Compared with flat polymer-coated fibers, the micropillar array markedly increased the effective sensing surface and enhanced light trapping by providing anti-reflective conditions at the interface. Consequently, the sensor demonstrated superior performance in refractive index sensing, yielding a sensitivity of 4.54 with an R² of 0.984, in contrast to 3.13 and 0.979 obtained for the flat counterpart. To validate its biosensing applicability, Interleukin-8 (IL-8), a cancer-associated cytokine, was selected as a model analyte. Direct immunoassays revealed quantitative detection across a broad dynamic range (0.1–1000 pg/mL) with a limit of detection of 0.013 pg/mL, while specificity was confirmed against non-target proteins. The proposed FO-LSPR platform thus offers a cost-effective and reproducible route to overcome the surface-area limitations of conventional designs, providing enhanced sensitivity and stability. These results highlight the potential of the micropillar-based FO-LSPR sensor for practical deployment in point-of-care diagnostics and real-time biomolecular monitoring. Full article

This paper investigates the transient stability of Grid-Forming (GFM) Permanent Magnet Synchronous Generator (PMSG) systems during grid faults. An analysis demonstrates how a fixed saturated current angle can trap the system in undesirable operating points, while reactive power coupling can degrade performance. Both factors pose a risk of turbine overspeed and instability. To overcome these vulnerabilities, a dual-mechanism control strategy is proposed, featuring an adaptive saturated current angle control that, unlike conventional fixed-angle methods, which risk creating Current Limiting Control (CLC) equilibrium points, dynamically aligns the current vector with the grid voltage to guarantee a stable post-fault trajectory. The effectiveness of the proposed strategy is validated through time-domain simulations in MATLAB/Simulink. The results show that the proposed control not only prevents overspeed trip failures seen in conventional methods but also reduces post-fault recovery time by over 60% and significantly improves system damping, ensuring robust fault ride-through and enhancing overall system stability. Full article

To address the issue of hysteresis nonlinearity adversely affecting the tracking accuracy of piezoelectric actuators, an improved particle swarm optimization (PSO) algorithm is proposed to improve the accuracy of hysteresis model parameter identification. Additionally, a discrete-time linear quadratic optimal tracking (DLQT) control strategy incorporating hysteresis compensation is developed to improve tracking performance. This study employs the Hammerstein model to characterize the nonlinear hysteresis behavior of piezoelectric actuators. Regarding parameter identification, the conventional PSO algorithm tends to suffer from premature convergence and being trapped in local optima. To address this, a cross-variation mechanism is introduced to enhance population diversity and improve global search ability. Furthermore, adaptive and dynamically adjustable inertia weights are designed based on evolutionary factors to balance exploration and exploitation, thereby enhancing convergence and identification accuracy. The inertia weights and learning factors are adaptively adjusted based on the evolutionary factor to balance local and global search capabilities and accelerate convergence. Benchmark function tests and model identification experiments demonstrate the improved algorithm’s superior convergence speed and accuracy. In terms of control strategy, a hysteresis compensator based on an asymmetric hysteresis model is designed to improve system linearity. To address the issues of incomplete hysteresis compensation and low tracking accuracy, a DLQT controller is developed based on hysteresis compensation. Hardware-in-the-loop tracking control experiments using single and composite frequency reference signals show that the relative error is below 3.3% in the no-load case and below 4.5% in the loaded case. Compared with the baseline method, the proposed control strategy achieves lower root-mean-square error and maximum steady-state error, demonstrating its effectiveness. Full article

Neutrophils are the most abundant immune cells in the human body. Neutrophil extracellular traps (NETs) have recently garnered significant attention as a novel, non-traditional mechanism for combating pathogenic microorganisms. Recent studies have shown that NETs play a crucial role in antiviral immunity, providing new perspectives on how neutrophils defend against viral invasion. Viruses not only induce NET formation through various mechanisms but have also developed multiple escape strategies targeting NETs. It is worth noting that NETs are a double-edged sword for the host: while they possess antiviral effects that inhibit viral spread and replication, their constituent components may also exacerbate tissue damage and play important pathological roles in the progression of certain viral infections. Therefore, a thorough understanding of the regulatory mechanisms and dynamic balance of NETs in viral infections is of critical importance. Additionally, since the components of NETs may vary depending on the stimulus, NET-related markers have the potential to serve as biomarkers for the severity and prognosis of viral diseases. This article provides a systematic review of the induction mechanisms, antiviral effects, viral escape strategies, and virus-induced NET-related immunopathological damage in viral infections, offering new insights for antiviral immunotherapy. Full article

With the global expansion of hydrogen infrastructure, the safe and efficient transportation of hydrogen is becoming more important. In this study, several technical factors, including material degradation, pressure variations, and monitoring effectiveness, that influence hydrogen transportation using pipelines are examined using system dynamics. The results show that hydrogen embrittlement, which is the result of microstructural trapping and limited diffusion in certain steels, can have a profound effect on pipeline integrity. Material incompatibility and pressure fluctuations deepen fatigue damage and leakage risk. Moreover, pipeline monitoring inefficiency, combined with hydrogen’s high flammability and diffusivity, can raise serious safety issues. An 80% decrease in monitoring efficiency will result in a 52% reduction in the total hydrogen provided to the end users. On the other hand, technical risks such as pressure fluctuations and material weakening from hydrogen embrittlement also affect overall system performance. It is essential to understand that real-time detection using hydrogen monitoring is particularly important and will lower the risk of leakage. It is crucial to know where hydrogen is lost and how it impacts transport efficiency. The model offers practical insights for developing stronger and more reliable hydrogen transport systems, thereby supporting the transition to a low-carbon energy future. Full article

Unmanned surface vehicles (USVs) rely on multi-sensor perception, such as radar, LiDAR, GPS, and vision, to ensure safe and efficient navigation in complex maritime environments. Traditional ant colony optimization (ACO) for path planning, however, suffers from premature convergence, slow adaptation, and poor smoothness in cluttered waters, while the dynamic window approach (DWA) without global guidance can become trapped in local obstacle configurations. This paper presents a sensor-oriented hybrid method that couples an improved ACO for global route planning with an enhanced DWA for local, real-time obstacle avoidance. In the global stage, the ACO state–transition rule integrates path length, obstacle clearance, and trajectory smoothness heuristics, while a cosine-annealed schedule adaptively balances exploration and exploitation. Pheromone updating combines local and global mechanisms under bounded limits, with a stagnation detector to restore diversity. In the local stage, the DWA cost function is redesigned under USV kinematics to integrate velocity adaptability, trajectory smoothness, and goal-deviation, using obstacle data that would typically originate from onboard sensors. Simulation studies, where obstacle maps emulate sensor-detected environments, show that the proposed method achieves shorter paths, faster convergence, smoother trajectories, larger safety margins, and higher success rates against dynamic obstacles compared with standalone ACO or DWA. These results demonstrate the method’s potential for sensor-based, real-time USV navigation and collision avoidance in complex maritime scenarios. Full article

Line traps are critical components of power line carrier systems, enabling remote control signaling, voice communication, and inter-substation control within electrical transmission and distribution networks. Despite their importance, limited research has addressed their seismic performance, particularly under near-fault and far-fault ground motions. This study addresses this gap by experimentally and numerically evaluating a full-scale 170 kV line trap. Ambient Vibration Tests (AVTs), using Enhanced Frequency Domain Decomposition (EFDD), and shake table testing established its modal and seismic response characteristics. A finite element (FE) model was then developed and calibrated using the experimental results. Dynamic analyses were conducted to evaluate the structural response under both near-fault and far-fault ground motions. Experimental findings revealed that the seismic response of the line trap increased with height, with the upper segment experiencing over four times the base acceleration. Numerical analyses further demonstrated that near-fault ground motions induced significantly higher displacement and acceleration responses than far-fault records. These findings collectively constitute a detailed investigation into the seismic performance of a full-scale line trap, emphasizing the pivotal role of ground motion characteristics in the structural evaluation of substation apparatus. Full article

Stomoxys calcitrans (Linnaeus, 1758) is a hematophagous fly species of veterinary importance, known for its negative effects on animal health and productivity. The stress caused by their painful bites results in losses in milk and meat production. Despite its impact, data on its ecology and activity in Algeria are lacking. Such knowledge is needed to evaluate its potential effects on livestock production and rural health, and to support surveillance, outbreak prediction, and control strategies. This study aimed to investigate the monthly and daily dynamics of S. calcitrans in livestock farms in the Batna region and evaluate the influence of climatic factors on its abundance. From July 2022 to July 2023, Vavoua traps were placed monthly from 7 a.m. to 6 p.m. on four farms in the Batna region, representing different livestock types. Captured flies were identified, sexed, and counted every two hours. Climatic data were collected both in situ and from NASA POWER datasets. Fly abundance was analyzed using non-parametric statistics, Spearman’s correlation, and multiple regression analysis. A total of 1244 S. calcitrans were captured, mainly from cattle farms. Activity occurred from August to December, with a peak in September. Males were more abundant and exhibited a bimodal activity in September. Fly abundance was positively correlated with temperature and precipitation and negatively correlated with wind speed and humidity. This study presents the first ecological data on S. calcitrans in northeastern Algeria, highlighting its seasonal dynamics and the climatic drivers that influence it. The results highlight the species’ preference for cattle and indicate that temperature and rainfall are key factors influencing its abundance. These findings lay the groundwork for targeted control strategies against this neglected pest in Algeria. Full article