Dynamic Field Research Articles

Long-Run Behavior and Convergence of Dynamic Mean Field Equilibria

AbstractWe study the behavior of dynamic equilibria in mean field games with large time horizons in a dynamic consumer choice model. We show that if the stationary equilibrium in the associated infinite horizon game is unique, the dynamic equilibria of the finite horizon games converge to the stationary equilibrium of the infinite horizon game as the time horizon tends to infinity. If the stationary equilibrium is not unique, however, the situation becomes more involved. In this case, we show that in addition to convergence to the stationary equilibria, in the long run, the dynamic equilibria circle around randomized stationary equilibria for certain choices of boundary data.

Sports and Nutrition: A Scientometric Review

Sports nutrition, a dynamic field, benefits competitive athletes. This study examines its evolution through Scopus and Web of Science trends. The authors employed ScientoPy software to analyse various publications, prominent sports (and) nutrition research areas, (pro)active authors in the field, keywords, popular sources, and institutional information. This study exploited the data reconciliation, cluster mapping, webmetric, and scientometric methodologies to analyse 1527 individual entries from the Scopus and Web of Science databases. These databases revealed that the most popular subject matters in the field were "sports nutrition" and "sport Science," with "sports nutrition" having the most 'keynoted' word in most nutrition and dietetics journals since 2019. "Muscle" is the second most popular subject matter in sports and nutrition, demonstrating its reputation in this study area, also experiencing a meteoric rise in popularity since 2019. Our findings showed the top five most popular keywords that gained traction (on a marginal analysis base) were "Sports nutrition," "Exercise," "Sports performance," "Nutrition," and "Dietary supplements." The study's contribution to sports and nutrition is that it grants readers and future researchers a spectrum of past and current sports nutrition trends. Also, the analysis from the study will help future researchers forecast potential industry trends.

Diffusion-driven flows in a nonlinear stratified fluid layer

Diffusion-driven flow is a boundary layer flow arising from the interplay of gravity and diffusion in density-stratified fluids when a gravitational field is non-parallel to an impermeable solid boundary. This study investigates diffusion-driven flow within a nonlinearly density-stratified fluid confined between two tilted parallel walls. We introduce an asymptotic expansion inspired by the centre manifold theory, where quantities are expanded in terms of derivatives of the cross-sectional averaged stratified scalar (such as salinity or temperature). This technique provides accurate approximations for velocity, density and pressure fields. Furthermore, we derive an evolution equation describing the cross-sectional averaged stratified scalar. This equation takes the form of the traditional diffusion equation but replaces the constant diffusion coefficient with a positive-definite function dependent on the solution's derivative. Numerical simulations validate the accuracy of our approximations. Our investigation of the effective equation reveals that the density profile depends on a non-dimensional parameter denoted as $\gamma$ representing the flow strength. In the large $\gamma$ limit, the system is approximated by a diffusion process with an augmented diffusion coefficient of $1+\cot ^{2}\theta$ , where $\theta$ signifies the inclination angle of the channel domain. This parameter regime is where diffusion-driven flow exhibits its strongest mixing ability. Conversely, in the small $\gamma$ regime, the density field behaves like pure diffusion with distorted isopycnals. Lastly, we show that the classical thin film equation aligns with the results obtained using the proposed expansion in the small $\gamma$ regime but fails to accurately describe the dynamics of the density field for large $\gamma$ .

On Integrability of Certain Classes of Variable Dissipation Systems

We study the non-conservative systems for which the methods for studying, for example, Hamiltonian systems is not applicable in general. Therefore, for such systems, it is necessary, in some sense, to “directly” integrate the main equation of dynamics. Herewith, we offer more universal interpretation of both obtained cases and new ones of complete integrability in transcendental functions in dynamics in a non-conservative force field.

Comparative Analyses of Dynamic Characteristics of Gas Phase Flow Field Within Different Structural Cyclone Separators

The gas phase flow field inside a cyclone separator is crucial to the particle separation process. Previous studies have paid attention to the steady-state characteristics of the gas phase flow field, while research on its dynamic characteristics remains insufficient. Meanwhile, cyclone separators often adopt different structural forms according to the process requirements, the evolution laws of the dynamic characteristics flow field within them are still not well understood. Therefore, in this study, a hot-wire anemometer (HWA) was employed to measure the instantaneous tangential velocity of the gas phase flow fields within different structural cyclone separators (cylinder type, cylinder–cone (no hopper), and cylinder–cone (with hopper)). Comparative analyses and discussions were conducted regarding the dynamic characteristic distribution rules of the flow field in the time domain and the frequency domain. The results revealed that the dimensionless tangential velocity distributions of different types of cyclone separators all conformed to the Rankine vortex structure. The instantaneous tangential velocity fluctuated with low frequency and high amplitude, and the low-frequency velocity fluctuation exhibited a transfer behavior along the radial direction. Compared with the cylinder–cone-type cyclone separator, the tangential velocity in the cylinder-type cyclone separator fluctuated more greatly, and its quasi-periodic behavior was also more obvious. The time-averaged tangential velocity, the tangential velocity fluctuation intensity (Sd), and the dominant fluctuation frequency all had obvious attenuation along the axial direction in the cylinder-type cyclone separator, while the above-mentioned parameters had no attenuation along the axial direction in cylinder–cone-type cyclone separators. Additionally, the backflow from the hopper of the cylinder–cone-type cyclone separator (with hopper) led to an increase in the instantaneous tangential velocity fluctuation intensity of the local flow field near the dust outlet, as well as the occurrence of the “double dominant frequencies” phenomenon.

Frequency Selective Surfaces: Design, Analysis, and Applications

This paper aims to provide a general review of the fundamental ideas, varieties, methods, and experimental research of the most advanced frequency selective surfaces available today. Frequency-selective surfaces are periodic structures engineered to work as spatial filters in interaction with electromagnetic (EM) waves with different frequencies, polarization, and incident angles in a desired and controlled way. They are usually made of periodic elements with dimensions less than the operational wavelength. The primary issue examined is the need for more efficient, compact, and adaptable electromagnetic filtering solutions. The research method involved a comprehensive review of recent advancements in FSS design, focusing on structural diversity, miniaturization, multiband operations, and the integration of active components for tunability and reconfigurability. Key findings include the development of highly selective miniaturized FSSs, innovative applications on flexible and textile substrates, and the exploration of FSSs for liquid and strain sensing. The conclusions emphasize the significant potential of FSS technology to enhance wireless communication, environmental monitoring, and defense applications. This study provides valuable insights into the design and application of FSSs, aiming to guide future research and development in this dynamic field.

An Appalled Ghost Guiding Readers Across Semiotic Fault Lines: The Contribution of Literature to the Appreciation of Legal Change

Abstract What are the conditions for meaning-making in intertextuality? The article explores what the relational dynamics of (legal) transtextuality can reveal about the semiotic hierarchies that govern them. The interest in these relational dynamics goes beyond the specific relations between texts captured by the hypo-/hyper-text relation. Rather, it embraces the inner conditions of meaning-making in transtextuality across multiple texts. Shifts in the underlying semiotic hierarchies can be tracked within each (legal) field, but the article turns to literature to explore the potential of intertextuality in exposing the transformative dynamics of various legal fields underneath the shifting semiotic hierarchies. Legal studies have variously investigated these shifting semiotic hierarchies, often resorting to the spectrum imposition/prestige (Sacco 1991) the article thus looks into the intertextuality of a literary text and what it can contribute to the analysis, beyond the spectrum. Egypt in the 19th century witnessed major legal transformations (Fahmy 2018; Hilāl 2011; Peters 2020). Just as major, however, were the transformations in legal discourse to accommodate a new vocabulary of ‘modern’ law, often drawing from Islamic law (Parolin 2016). The dynamic relations between alternative legal discourses and their semiotic hierarchies almost imperceptibly transformed over the course of the century, but by the end of the century these hierarchies were nearly entirely redrawn, and Islamic legal discourse had to be characterised or adjectivised as ‘Islamic’ (Parolin 2015). The article thus considers one of the canonical works of late 19th century Egyptian literature, Muḥammad al-Muwayliḥī’s What ʿĪsá bin Hishām Told Us (1898–1901). In it, the author describes with irony the shock and tribulations of the ghost of a mid-19th century personality in his encounter with late 19th century Egypt. Al-Muwayliḥī’s is however a brilliant fictional device to stage al-Muwayliḥī’s own shock and the shock of late 19th century Egyptians at the transformations of the country in a few decades. His humourous account precisely begins with changes in law and its enforcement agencies. Not only does legal discourse often capture the enormity of these legal transformations, but also how other elements of legal semiotics witness to far-reaching transformations that cause the ghost much tribulation, on top of the shock.

Navigating Challenges in Online Cybersecurity Education: Insights from Postgraduate Students and Prospects for a Standardized Framework

This study focuses on the challenges encountered in online cybersecurity education. It adopts an exploratory research design using a mixed-methods approach to investigate the perceptions and experiences of postgraduate students enrolled in an online cybersecurity program. The collection of data is structured into two distinct phases. In the initial phase, qualitative insights are gathered through workshops with students and industry experts, followed by administering a questionnaire to delve deeper into students’ perceptions and challenges. Thematic analysis of the responses reveals significant interest in online cybersecurity programs but also highlights issues such as ineffective communication and poor engagement. The findings highlight the necessity for a standardized framework to improve communication, engagement, and overall effectiveness in virtual learning environments. By empowering instructors to design more interactive courses and leveraging technology efficiently, the framework aims to improve student motivation, satisfaction, and learning outcomes. Moreover, it serves as a valuable resource for institutions, fostering collaboration and innovation in cybersecurity education. Implementing this framework will create a more conducive learning environment, directly enhancing student preparation for success in the dynamic field of cybersecurity.

Evolution laws of charge mobility of transformer oil and pressboard material with temperature and electric field strength

Abstract Charge mobility, a pivotal parameter in the space charge analysis model for oil-pressboard insulation of converter transformer under DC electric fields, predominantly relies on theoretical or empirical data. The prevalent omission of empirical, measurement-based evaluations, combined with the neglect of temperature and electric field intensity effects, introduces uncertainties in the calculation of electric field and charge dynamics. Grounded on the principles of the electroacoustic pulse technique for space charge measurements, our investigation established a temperature-controlled platform to determine the charge-charge mobility in oil and pressboard insulation mediums. Utilizing diverse oil-pressboard insulation systems, this study identified the temporal patterns of both positive and negative charge mobilities and unravelled the mechanisms modulated by temperature and electric field intensity: 1) With increasing temperatures (from 20°C to 80°C) and intensifying electric field strengths (from 5kV/mm to 25kV/mm), the charge mobility within transformer oil and pressboard exhibits a rising trend. Notably, temperature variations exert the most significant influence, yielding amplifications up to 24.8 times. 2) The intrinsic properties of different transformer oils and oil-impregnated pressboards result in pronounced differences in their charge transport behaviours. Specifically, naphthenic-based oil demonstrates enhanced charge mobility relative to its paraffin-based counterpart. In contrast, transformer oils with higher kinematic viscosities exhibit diminished charge mobility compared to those with lower viscosities. 3) A linear relationship is observed between the oil absorption rate and electrical conductivity, aligning closely with the insulating pressboard's charge mobility. The evaluation of electric field and interface charge dynamics in oil-pressboard insulation under both DC and polarity-reversed conditions revealed that the electric field decay in naphthenic-based oil is more rapid than in paraffin-based oils. Moreover, both the magnitude and rate of interface charge accumulation in naphthenic-based oils exceed those in paraffin-based variants, further validating the accuracy of our charge mobility measurements and ensuing analysis.

Giving the prostate the boost it needs: Spiral diffusion MRI using a high-performance whole-body gradient system for high b-values at short echo times.

To address key issues of low SNR and image distortions in prostate diffusion MRI (dMRI) by means of using strong gradients, single-shot spiral readouts and an expanded encoding model for image reconstruction. Diffusion-weighted spin echo imaging with EPI and spiral readouts is performed on a whole-body system equipped with strong gradients (up to 250 mT/m). An expanded encoding model including static off-resonance, coil sensitivities, and magnetic field dynamics is employed for image reconstruction. The acquisitions are performed on a phantom and in vivo (one healthy volunteer and one patient with prostate cancer). The resulting images are compared to conventional dMRI EPI with navigator-based image reconstruction and assessed in terms of their congruence, SNR, tissue contrast, and quantitative parameters. Using the expanded encoding model, high-quality images of the prostate gland are obtained across all b-values (up to 3 ms/μm2), clearly outperforming the results obtained with conventional image reconstruction. Compared to EPI, spiral imaging provides an SNR gain up to 45% within the gland and even higher in the lesion. In addition, prostate dMRI with single-shot spirals at submillimeter in-plane resolution (0.85 mm) is accomplished. The combination of strong gradients and an expanded encoding model enables imaging of the prostate with unprecedented image quality. Replacing the commonly used EPI with spirals provides the inherent benefit of shorter echo times and superior readout efficiency and results in higher SNR, which is in particular relevant for considered applications.

The Aerodynamic Assessment and Shot Point Position Accuracy of UAV Seismic Source

An unmanned aerial vehicle (UAV) seismic source, suitable for complex terrains due to its eco-friendly, cost-effective, and efficient nature, operates by hovering and releasing impact objects to generate seismic waves. The aerodynamic behavior of these impact objects is vital for shotpoint position accuracy and drag magnitude. Excessive drag will result in the loss of seismic source energy, whereas the deviations of the shotpoint position will disrupt the geometric structure of the observation system, significantly impacting the quality of seismic data acquisition. Through theoretical calculations, the influencing factors of air resistance and cross-wind deflection are analyzed. Air resistance increases with the increase in mass, cross-sectional area, speed, and drag coefficient. Increasing the mass and throwing height can increase the upper limit of the output, but after the air resistance and gravity are balanced, the output kinetic energy of the drone’s seismic source will no longer increase when the throwing height is increased. Using computational fluid dynamics simulations and field tests, this study examines the aerodynamics of four prevalent impact object designs. The results show that shuttle and spherical structures have the least drag during descent and are less influenced by crosswinds, thus being optimal for this application. Field measurement data are also presented for reference.

Power and theory: toward a multidimensional explanation of the dynamic political field

ABSTRACT What theories explain a dynamic political field and its outcome? Can we judiciously combine theories into a better hybrid explanation? To be valid, a theory’s claimed causal factor must manifest in the field as a representative mode of micro power used between actors in dyads (its mechanism). The modes’ relative presence indicates the theories’ relative causal validity. The Integrated Structurational Analysis method analyzes (hundreds of) actor dyads to find evidence on the relative presence of the modes. The results indicate a shifting, multidimensional causal timescape driving the field and its outcome. Findings from a Japanese case study illustrate the method.

Unravelling the Significance of Seed Proteomics: Insights into Seed Development, Function, and Agricultural Applications.

Seeds are essential for plant reproduction, ensuring species survival and dispersal while adapting to diverse environments throughout a plant's life. Proteomics has emerged as a powerful tool for deciphering the complexities of seed growth, germination, and stress responses. Advanced proteomic technologies enable the analysis of protein changes during germination, dormancy, and ageing, enhancing our understanding of seed lifespan and vitality. Recent studies have revealed detailed insights into metabolic processes and storage protein profiles across various plant species. This knowledge is crucial for improving seed storage, conserving quality, and maintaining viability. Additionally, it contributes to sustainable agriculture by identifying stress-responsive proteins and signalling pathways that can mitigate stress and enhance farming practices. This review highlights significant advancements in seed proteomics over the past decade, discussing critical discoveries related to storage proteins, protein interactions, and proteome modifications due to stress. It illustrates how these insights transform seed biology, boosting productivity, food security, and environmentally friendly practices. The review also identifies existing knowledge gaps and provides direction for future research, underscoring the need for continued interdisciplinary collaboration in this dynamic field.

Distinguishing Inner and Outer-Sphere Hot Electron Transfer in Au/p-GaN Photocathodes.

Exploring nonequilibrium hot carriers from plasmonic metal nanostructures is a dynamic field in optoelectronics, with applications including photochemical reactions for solar fuel generation. The hot carrier injection mechanism and the reaction rate are highly impacted by the metal/molecule interaction. However, determining the primary type of reaction and thus the injection mechanism of hot carriers has remained elusive. In this work, we reveal an electron injection mechanism deviating from a purely outer-sphere process for the reduction of ferricyanide redox molecule in a gold/p-type gallium nitride (Au/p-GaN) photocathode system. Combining our experimental approach with ab initio simulations, we discovered that an efficient inner-sphere transfer of low-energy electrons leads to an enhancement in the photocathode device performance in the interband regime. These findings provide important mechanistic insights, showing our methodology as a powerful tool for analyzing and engineering hot-carrier-driven processes in plasmonic photocatalytic systems and optoelectronic devices.

Mapping knowledge structures and theme trends in sport diplomacy: a bibliometric analysis

This study aims to analyse knowledge structures and thematic trends in sport diplomacy, an increasingly prominent field. Using bibliometric analysis of 331 studies from the Web of Science (WoS) database, this study identified several key themes, including the role of sport in promoting peace and diplomacy, the use of sport as a tool for soft power, and the challenges and opportunities of hosting sport mega-events. The study also identified several knowledge structures, including the relationship between sport and (international) politics, globalization, and the role of sport in cultural diplomacy. These findings provide insights for researchers, policymakers, and practitioners, guiding theory development, interdisciplinary collaboration, and practical applications. In summary, this study contributes to understanding the evolution and current state of sport diplomacy scholarship, fostering continued progress in this dynamic field.

Dynamics of optical solitons and sensitivity analysis in fiber optics

The nonlinear Schrödinger equation (NLSE) and its various forms have significant applications in the field of soliton theory. The Fokas-Lenells (FL) equation stands as a cornerstone in deepening our understanding of nonlinear wave dynamics within optical systems, particularly concerning the behavior of ultrashort pulses across different media. Its significance lies in providing a comprehensive framework to study and analyze complex phenomena, ultimately contributing to advancements in optical technology and applications. The FL equation is an integrable extension of the NLSE that provides a description of the nonlinear propagation of pulses in optical fiber. This paper seeks to discover optical soliton solutions for the FL equation by employing a modified sub-equation method. Additionally, the sensitivity analysis is described by using the various initial conditions. The main novelty of this paper lies in conducting a sensitivity analysis of the FL equation by examining the effects of various initial conditions, providing deeper insights into how these conditions influence the behavior of soliton solutions. For the physical behavior of the models, some solutions are graphically shown in 2D, 3D, and contour graphs by assigning specific values to the parameters under the provided situation at each solution. As a result, we discovered several new families of exact traveling wave solutions, such as bright solitons, dark solitons, and combined bright and dark solitons. This research opens numerous avenues for further exploration in the field of nonlinear wave dynamics and optical soliton theory. The discovery of exact soliton solutions for the FL equation through a modified sub-equation method paves the way for deeper investigations for newcomer researchers. The results of this study will contribute further to the field of mathematical physics, particularly in enhancing the understanding of nonlinear wave propagation and soliton theory in optical and other physical systems.

Renormalization in Lorenz maps - completely invariant sets and periodic orbits

The paper deals with dynamics of expanding Lorenz maps, which appear in a natural way as Poincarè maps in geometric models of well-known Lorenz attractor. Using both analytical and symbolic approaches, we study connections between periodic points, completely invariant sets and renormalizations. We show that some renormalizations may be connected with completely invariant sets while some others don't. We provide an algorithm to detect the renormalizations that can be recovered from completely invariant sets. Furthermore, we discuss the importance of distinguish one-side and double-side preimage. This way we provide a better insight into the structure of renormalizations in Lorenz maps. These relations remained unnoticed in the literature, therefore we are correcting some gaps existing in the literature, improving and completing to some extent the description of possible dynamics in this important field of study.

Soil metabolic processes influenced by rice roots co-regulates the environmental evolution of antibiotic resistome

Plant root activities lead to significant differences in metabolites between the rhizosphere and non-rhizosphere soil, profoundly affecting microbial distribution. However, how this process drives the migration and propagation of manure-derived antibiotic resistance genes (ARGs) in farmland ecosystems remains unclear. Herein, we used a rice pot microcosm experiment to explore the characteristics of antibiotic resistome and bacterial communities in rhizosphere and non-rhizosphere soils and the driving effects of rhizosphere metabolites on ARG propagation. The results showed significant differences in some ARGs and bacterial diversity in rhizosphere and non-rhizosphere soils with varied differential ARGs between different growth stages of rice (P < 0.05). The biosynthesis of secondary metabolites and glutathione metabolism were found to be the main pathways affecting ARG differences in rhizosphere and non-rhizosphere soils under manure application. Structural equation modeling (SEM) analysis further indicated that ARG distribution differences between rhizosphere and non-rhizosphere soils were mainly regulated by differential metabolites, which influenced the ARG distribution by altering the succession of soil microbial communities. These results demonstrate the role of differential metabolites resulting from rice root activities in co-regulating ARG distribution, providing new insights into the regulatory mechanisms of soil ARG dynamics in paddy fields.

Westward Displacement of Atmospheric East–West Circulation Ameliorated Drought-Induced Conditions in Australia and India during the Major 2023–24 and 1997–98 El Niño Events

Abstract Based on a compilation of widely available climate analysis products, we show evidence for a significant variation in the spatial pattern of the large-scale vertical zonal atmospheric circulation patterns across the equatorial Indo-Australasian domain of the Eastern Hemisphere during the major 2023–24 El Niño event. The region of large-scale subsidence and its associated teleconnection patterns that are usually centered across Indonesia (the “Maritime Continent”) were displaced to the west over the equatorial Indian Ocean. In the record of El Niño events with readily available online dynamical tropospheric fields (one source from 1947 and the other from 1979), this has only been seen two other times, during the strong 1997–98 El Niño and the weaker 1977–78 event. These three events may well be consistent with internal variability, but at present, the reason for such occurrences has not been established.

Direct hydroacoustics analyses of pipe orifice using lattice Boltzmann method

Acoustic waves in water pipes pose a structural threat but also offer a valuable tool for non-invasive inspection. Complex pipe geometries such as bends and surface liners create complex fluid boundaries, triggering interactions between fluid flow and acoustics. The lattice Boltzmann method (LBM) excels at capturing these interactions near complex boundaries, in contrast to the finite volume method, which can result in errors. However, the application of LBM in water pipes has been limited by stability problems. This study proposes a two-step (DM-TS) collision operator based on a direct method (LBM-HA) for stable LBM simulations in water pipes. LBM-HA enables direct hydroacoustic predictions for both acoustic and dynamic flow fields in a pipe orifice. A novel acoustic-dynamic complex boundary condition was formulated from the linearized Euler's equation to account for the physical effects of the bounded domain of the LBM-HA analysis. To distinguish between dynamic and acoustic components, wavenumber and frequency decomposition techniques were applied to the pressure data obtained within the pipe. In addition, mode decomposition of the acoustic pressure was conducted to identify the dominant acoustic modes. By comparing the LBM-HA results with experimental data, we highlighted the method's potential for direct hydroacoustic analysis considering the acoustic characteristics of the water pipe.