The European Physical Journal Special Topics最新文献

This study investigates the master–slave synchronization criteria for four-dimensional electrocardiogram (ECG) chaotic networks, focusing on the interconnecting electrical potentials in the sinoatrial and atrioventricular nodes. The model encompasses electrocardiograms from healthy hearts and those with known rhythm abnormalities such as atrial flutter, ventricular tachycardia, and ventricular flutter. For the first time, a state feedback controller is employed to address the master–slave synchronization problem of stochastic ECG chaotic networks (SECCNs) for both pathological and non-pathological heartbeats. We establish a sufficient condition based on a quadratic Lyapunov-Krasovskii functional, ensuring synchronization of the SECCNs to the desired state. Furthermore, we provide a numerical simulation to illustrate the theoretical findings.

This study uses deep learning methods to classify the projection of the attractor’s images of five different chaotic systems. The chaotic systems addressed in the research are Sprott C, Sprott F, Sprott G, Sprott H, and Sprott M. A dataset was created for classification using the projection of attractors of these five different chaotic systems. This dataset contains time series images, and the graphs are generated based on initial conditions, Runge–Kutta 4 step size, and time length. Deep learning methods such as ResNet50, ResNet50V2, VGG19, InceptionV3, MobileNetV2, and VGG16 have been utilized for classification. This study's classification accuracy varies between 91.6% and 99.9%, depending on the problem. Therefore, this research accurately determines which chaotic system a projection of the attractors graphic image belongs to. This high accuracy demonstrates the usability of this model in analyzing chaotic systems in real-world applications. Such accuracies can be considered a powerful tool in analyzing industrial systems or other systems with complex structures. This work successfully uses deep learning methods for classifying chaotic systems. Such research could be an important step toward understanding and managing complex systems.

This manuscript explains the approximate controllability of (psi)-Hilfer fractional neutral hemivariational inequalities ((psi)-HFNHVI) with infinite delay via an almost sectorial operator. The facts related to semigroup theory, Hilfer fractional derivative (HFD), fractional calculus, the fixed point approach, and multi-valued maps are used to prove the results. Initially, we show the existence of a mild solution and exhibit that the (psi)-Hilfer fractional system is approximately controllable. Further, we have provided an example.

The importance of touch in human social development and interpersonal interactions is widely recognized, yet the underlying neurological processes remain relatively unexplored. To better understand these mechanisms, we analyzed functional magnetic resonance imaging (fMRI) data to investigate how affective touch influences brain activity. Our study employed independent component analysis (ICA) and cluster analysis to identify brain components that exhibit significant changes following tactile stimulation. These components were then mapped to large-scale brain networks, focusing on those with the most pronounced spatial intensity differences. Our findings highlight the crucial role of distinct brain networks in processing tactile sensations. Notably, we observed significant changes in the default mode network (DMN) activity, particularly in the control group, after the touch experiment. Additionally, specific alterations were detected in the amygdala, cuneus, and orbitofrontal cortex. This study sheds light on the neurological foundations of tactile experiences and their potential impact on behavior and emotional states. Understanding these processes could inform the development of therapeutic strategies that leverage touch to alleviate stress and enhance mental health.

In the area of photovoltaics, monocrystalline silicon solar cells are ubiquitously utilized in buildings, commercial, defense, residential, space, and transportation applications throughout the world. Their performance is impeded by the heating of the cells during their interaction with the incident solar radiation. The development of reliable computer simulations that effectively model the thermal response of monocrystalline silicon solar cells is critical for their design, fabrication, and utilization. This work employs a novel computer simulation to incorporate the optical, electrical, and thermal properties of silicon in the thermal analysis of silicon solar cells. After establishing the theoretical principles and the values of these properties, the results of the simulation are compared with other established studies. The analysis shows that the percentage difference in solar cell temperatures between simulation and literature is within a range of 0.354–0.487%. The proposed simulation shows that the visible range of wavelengths is the dominant source of heating in commercial monocrystalline silicon solar cells.

The non-thermally produced freeze-in dark matter is an attractive alternative to look beyond the weakly interacting massive particle (WIMP) paradigm. With the singlet-doublet dark matter model, a simple extension to the standard model (SM), we probe the light dark matter parameter space, assuming feeble couplings between SM particles and the dark matter candidate. We tried to show how non-standard cosmological background affects dark matter production in the early Universe and alters the search strategy at colliders. We found that the prompt decay search using the jet substructure analysis is more effective than the existing displaced vertex searches.

In the era of precision medicine, cell-based therapy is one of the most promising techniques to fight against cancer cells or for the regeneration of diseased tissues/organs. In cell-based therapy, sensitive and quantitative detection of cells is of great importance and interest to understand the behavior of the cells in vivo. Existing techniques, including magnetic resonance imaging, X-ray computed tomography and optical imaging, suffer from some limitation on sensitive cell quantification. In this paper, we report on the approach of sensitive and quantitative detection of magnetic nanoparticle (MNP)-labelled cells with magnetic particle spectroscopy (MPS). The influence of the MNP dynamics on the MPS signal of the MNPs is investigated and analyzed. Finally, the MPS signal of the MNPs is measured to quantify cell amount with a limit-of-detection of 200 and with a linearity of better than 98%. The work presented in this paper has great potential for providing a novel tool for in vivo cell detection and tracking during cell-based therapy.

The present article is designed to study the Hamilton and Crosser model applied to the flow of ternary hybrid nanofluids over a Riga wedge, incorporating the effects of heterogeneous catalytic reactions. The complex interactions within the ternary hybrid nanofluids, comprising three distinct nanoparticles suspended in a base fluid, present significant challenges in accurately predicting flow and thermal characteristics. The Hamilton and Crosser model, known for its efficacy in determining the thermal conductivity of composite materials, is employed to analyze this intricate system. The analysis reveals the model's potential in offering a comprehensive understanding of the thermal and fluid dynamics involved, highlighting its suitability for predicting the behavior of ternary hybrid nanofluids in the presence of catalytic reactions. The governing model equations and boundary conditions are non-dimensionalized by introducing suitable similarity transformations. Thereafter, the computational Chebyshev collocation spectral technique implemented in the MATHEMATICA 11.3 software is used to calculate the numerical solution. The study reveals that the Casson parameter has a negative influence on the velocity distribution, causing it to reduce as the Casson parameter rises. This research contributes to the advancement of modeling techniques for complex fluid systems, with implications for enhanced design and optimization in various industrial and engineering applications.

The present study investigates the scattering of ocean wave and currents by an inverted T-type lightweight surface-piercing wave barrier that is situated over a uniform sea bed. To handle the boundary value problem (BVP), an iterative boundary element method (BEM) has been used. To analyze the efficacy of employing thin wave barriers, the impact of porosity, relative submergence depth and width of the barrier on the hydrodynamic properties (like wave force, reflection, dissipation, and transmission) are investigated in the presence of ocean currents. The simulated outcomes demonstrate that the Doppler Shift effect of the frequency due to the presence of ocean currents significantly influences the behaviour of the aforementioned hydrodynamic properties. Moreover, these simulated results also demonstrate that the use of lightweight wave barriers provides a better wave energy dissipation compared to the bulky submerged structures.

Left ventricular assist devices (LVADs) have proven to be the best alternative treatment to address the increasing number of heart failures, while donors are in short supply. However, ventricular assist devices (VADs) have been linked to thrombosis, hemolysis, and other postoperative complications. Despite significant technological advancements, blood damage caused by high shear stress generation has remained a serious concern, which is greatly attributed to the VAD's geometry. The goal of this research is to develop a centrifugal pump design using computational fluid dynamics (CFD) and experimental evaluation. Based on characteristics such as pressure head generation, flow rate, maximum wall shear stress, and hydraulic efficiency, the simulations produce a pump design suitable for mechanical circulatory support. The subsequent experimental testing for pressure head and flow rates validate the CFD outcomes. Further, the pump is installed in an indigenously designed mock circulation loop to examine its capability as an LVAD. The outcomes of CFD and experimental studies reveal that the developed pump is well capable of delivering blood with a flow rate at the required pressure as per desired physiological requirements. Also, the wall shear stress values are within the limit (< 300 N/m²) to avoid any blood damage.