State Behavior Research Articles

Volatile and Nonvolatile Dual‐Mode Switching Operations in an Ag‐Ag2S Core‐Shell Nanoparticle Atomic Switch Network

AbstractThis paper proposes a nanoparticle‐based atomic switch network memristive device, capable of both volatile and nonvolatile switching operations, which have not been previously reported for this material. The operational modes can be determined by altering the compliance current, demonstrating high stability over 100 cycles. Analysis of the conduction mechanism using I–V curves reveals switching characteristics consistent with space‐charge‐limited current conduction during the set process and ohmic behavior in the reset state. Furthermore, this study analyzes these dual‐operational modes in devices with varying electrode spacings. The results indicate that a wider spacing necessitated a higher compliance current for the volatile‐to‐nonvolatile transition, underscoring the significance of interconnection. These findings facilitate the integration of neuron and synapse functions within a single atomic switch network device, thereby advancing neuromorphic systems.

A novel model-based Cauchy-Schwarz divergence condition indicator for gears monitoring during fluctuating speed conditions

Gear monitoring and fault diagnosis are vital for preventing accidents and minimizing economic losses in transportation and industrial systems. Traditional methods use vibration sensors and a two-stage analysis approach: preprocessing data to remove noise and extract relevant components, and generating a condition indicator to detect behavioral anomalies in the gears over time.Time synchronous averaging is a notable tool for monitoring gears at constant speeds. Such a tool filters sensor signals and extracts rotation-related components by using statistical measurements as condition indicators. However, it has limitations in scenarios with time-varying sampling rates and fluctuating speeds, where statistical measures may not fully capture changes in system parameters.This article proposes a novel methodology for monitoring gears in multivariate rotordynamical systems under fluctuating speed conditions. The method integrates time synchronous averaging, system identification algorithms, and statistical tools. It generates a time-synchronous average signal considering speed fluctuations, computes a state–space model of gear behavior in healthy states, extracts residual data from a data-driven model, and generates a condition indicator based on the Cauchy–Schwarz divergence.The proposed methodology was evaluated using experimental data from three rotor dynamical setups under different operational conditions. Validation showed its effectiveness, especially under high-load conditions with significant speed fluctuations.

Post Covid Effect on the Nutritional Status, Academic Interest and Psycho-Social Behaviors among College Students

The COVID-19 epidemic has eclipsed global development activities. Global political, financial, and technical resources have been mobilised to combat the COVID-19 pandemic. The pandemic’s impact will be long-lasting, affecting all aspects of human life and impeding all developmental endeavours, including the ambitious and aspirational Sustainable Development Goals. Good nutrition is an essential criterion for adolescent health, productivity, and functional efficiency. The present study was to investigate the impact of covid 19 to young people’s health and nutritional state, academic interest, and psychosocial behaviour. This is a cross-sectional study in which 100 adolescents aged 18 to 21 years were assessed for anthropometry, nutritional profile, and perceived stress using relevant scales. The findings demonstrated an association between good nutritional status and psychosocial behaviour in adolescents. In addition, the COVID-19 pandemic has had a significant impact on adolescents’ dietary status, academic interest, and psychosocial behaviour. This study provides novel ideas for future policies and intervention programmes.

Turbulent and non-turbulent analysis of thermomagnetic convection and heat transfer of darcian radiative nanofluid flow across inclined stretching surface in microgravity environment

Turbulent and non-turbulent analysis of thermomagnetic convection, heating rate and mass transport of Darcian radiating nanofluid flow through porous slanted sheet is the aim of present study. Influence of microgravity is more useful for the movement of thermophoresis nanoparticles with maximum temperature and density. Joule heating, porous medium, magnetic field and thermal radiations are incorporated for the performance of thermal convection. Governing equations are reduced in dimensionless form. Oscillatory stokes conditions are applied to separate the steady, real and imaginary equations. Finite difference, Primitive transformation, and Gaussian elimination techniques are applied for numerical outputs. For asymptotic results, the appropriate range of parameters such as 0.1≤JH≤15.0, 0.1≤Pr≤12.0, 0.1≤Rd≤25.0, 0.0≤λT≤5.0, 0.1≤NT≤1.0, 0.1≤Fr≥6.0, and 0.1≤δ≤1.0 is utilized. Main novelty of work is to examine the steady state and oscillatory behavior of friction-rate, heat/mass transport over slanted two-angles π/6 and π/4. Maximum amplitude in fluid velocity is observed by increasing radiations and buoyant forces. Temperature distribution and nanomaterial concentrations enhance as Joule-heating and Prandtl number increases under microgravity region. Amplitude and oscillation of heat and mass rate is increased as reaction rate, Joule heating and Forchheimer parameter increases. Enhancing behavior of energy transport is observed for maximum choice of Prandtl index with small magnetic effects. It is depicted that high rate of oscillating frequency in heat transmission is detected with maximum radiation effects.

Spontaneous Transition between Multiple Conductance States and Rectifying Behaviors in an Artificial Single‐Molecule Funnel

It has long been an aspirational goal to create artificial channel structures that replicate the feat achieved by ion channel proteins. Biological ion channels occasionally demonstrate multiple conductance states (known as subconductance), remaining a challenging property to achieve in artificial channel molecules. We report a funnel‐shaped single‐molecule channel constructed by an electron‐deficient macrocycle and two electron‐deficient aromatic imide arms. Planar lipid bilayer measurements reveal distinct current recordings, including a closed state, two conducting states, and spontaneous transitions between the three states, resembling the events seen in biological ion channels. The transitions result from conformational changes induced by chloride transport in the channel molecule. Both opening states show a non‐linear and rectifying I‐V relationship, indicating voltage‐dependent transport due to the asymmetrical channel structure. This work could enhance our understanding of ion permeation and channel opening mechanism.

Coarse graining correlation matrices according to macrostructures: financial markets as a paradigm

We analyze correlation structures in financial markets by coarse graining the Pearson correlation matrices according to market sectors to obtain Guhr matrices using Guhr’s correlation method according to P Rinn et al (2015, Europhysics Letters 110, 68 003). We compare the results for the evolution of market states and the corresponding transition matrices with those obtained using Pearson correlation matrices. The behavior of market states is found to be similar for both the coarse grained and Pearson matrices. However, the number of relevant variables is reduced by orders of magnitude.

Democratization in the age of artificial intelligence: introduction to the special issue

ABSTRACT As artificial intelligence (AI) technologies become ubiquitous, research on their implications for democratization has blossomed. Will AI empower citizens and strengthen democracy or fuel the rise of autocracy? This special issue brings together diverse theoretical, conceptual, and empirical contributions to offer a synoptic perspective on this question across political contexts. In this introduction, we argue that the most significant socio-technical novelty pertaining to AI - the possibility for automated hyper-personalization - catalyses four structural changes that capture the complex relationship between AI, democratization, and autocratization. First, technology corporations have emerged as a new quasi-governing class that holds political power without democratic legitimacy. Second, automated hyper-personalization has transformed the citizen-state relationship by fostering hyper-technocracy and paternalism in democracies, and enhancing regimes' repertoires for controlling citizens in autocracies. Third, AI is changing the environment in which citizens exercise their political rights, exacerbating political polarization, societal fragmentation, and apathy. Finally, at the international level, AI has created new arenas for competition between democratic and authoritarian states, engendering a struggle for both technological capabilities and the values and norms that will govern them. The articles in this special issue explore these dynamics from micro impacts to structural changes in state behaviour and international relations.

Role conceptions and diplomatic behaviours: comparing Japan and South Korea in the South China Sea

ABSTRACT The South China Sea is a region marked by overlapping territorial claims and escalating tensions among various nations. Unlike claimant states, whose direct territorial interests significantly shape their foreign policy decisions, non-claimant states possess a broader range of diplomatic options. This article examines the contrasting diplomatic behaviours of non-claimant regional states in the South China Sea disputes. Through a comparative case study of Japan and South Korea, it argues that the divergent responses of these two middle powers largely stem from the roles they assume within the policy arena. Japan, as an assertive actor driven by a sense of obligation, has actively taken positions on disputed events to demonstrate its presence. Conversely, South Korea, adopting the role of a detached observer, has exercised caution and maintained a low profile, aiming to avoid potential diplomatic costs. The findings highlight the significance of ideational factors in influencing regional states’ responses to security challenges. Furthermore, this study contributes to role theory research by introducing a new term for further study and by demonstrating the tangible effects of role conceptions on state behaviour in specific policy contexts.

SHG behavior of the solid isomorphic compounds Ni- and Cu-5,10,15,20- tetraphenylporphyrinate. An experimental and theoretical study

We prepared and investigated the SHG behavior in the solid state of the two isomorphic Nickel and Copper 5,10,15,20-tetraphenylporphyrinate, that crystallize in the same acentric I4¯2d space group. The compounds were synthesized and characterized, and the Second Harmonic Generation (SHG) response of powdered samples was measured employing a 1.907 μm pulsed laser radiation. During laser irradiation, for both compounds, a gradual increase of the intensity of the SH signal was observed until, after a few minutes, it reached a plateau of about fifty times (for the Ni-TPP) or ten times (for the Cu-TPP) the initial value. We attempted to understand the origin of this phenomenon both through experimental analysis and theoretical calculations. Absorption and vibrational spectroscopies, in solution and solid state, combined with powder X-ray diffraction, both before and after irradiation, do not evidence any chemical degradation, phase transition or amorphization process. Theoretical calculations on little fragments of the Ni/Cu-TPP structure simulate appropriately the structural features of the complexes and their initial experimental SHG response. Magnetic balance measurement in the solid state before and after irradiation, in conjunction with DFT/B3LYP optimization of excited spin states and TDDFT calculations, highlight a change in the electronic and/or spin state due to the irradiation of the complexes.

Effects of substituted chalcogen atoms on excited state proton transfer reaction for 2,5‐bis(benzoxazole‐2‐yl)‐thiophene‐3,4‐diol derivatives: A theoretical study

AbstractMotivated by the captivating allure of exquisitely regulated characteristics exhibited by 2‐(2‐hydroxyphenyl)‐benzoxazole and its derivatives in the domains of photochemistry and photophysics, our current endeavor primarily focuses on delving into the intricacies of photo‐induced excited state reactions for derivatives of 2,5‐bis(benzoxazol‐2‐yl)‐thiophene‐3,4‐diol (BTD). Given the profound impact of chalcogen element doping, our primary focus lies in investigating the excited state behaviors of BTD‐O, BTD‐S, and BTD‐Se fluorophores. Through simulations encompassing variations in geometry and vertical excitation charge reorganization, we unveil atomic‐electronegativity‐dependent hydrogen bonding interactions and photoexcitation‐induced charge recombination that can significantly augment the intramolecular double proton transfer (ESDPT) reaction in the excited state for BTD‐O, BTD‐S, and BTD‐Se fluorophores. By constructing potential energy surfaces and identifying transition state forms, we elucidate the ultrafast stepwise ESDPT mechanism facilitated by the low potential barriers. Moreover, we rigorously validate the chalcogen atomic electronegativity‐driven regulation of the stepwise ESDPT mechanism. We sincerely anticipate that manipulating solvent polarity will pave the way for groundbreaking advancements in luminescent materials.

Online Multi-Resource Allocation for Network Slicing in 5G with Distributed Algorithms

With the increasing scale of mobile cellular network applications, 5G mobile network infrastructure provides customizable services to users in the form of network slices. How to effectively allocate existing resources in real dynamic networks with time-varying network utility is a key issue that previous work did not consider. This paper first initializes the multi-resource allocation problem of network slicing in an online manner, where the utility function is set to change over time. Therefore, we propose Metis, an online network slicing resource allocation framework that combines the time-varying nature of the network utility function given bandwidth and processing power constraints with the requirement of virtual network function isolation. The goal is to maximize the cumulative network utility in the long term and specify multiple resource allocation problems by utilizing concave optimization methods. In addition, a distributed algorithm based on the online alternating direction method of multipliers with regret optimization has been developed to achieve optimal resource allocation. Our mathematical analysis proves that Metis can provably converge to the optimal solution and the result of experiments demonstrates a steady state behavior of Metis, which converges in dynamic network settings.

Exploring the speed of change: European defence budgets in an age of danger

ABSTRACT This essay explores the theme of speed of change in defence budgets for nations that experience violent deteriorations in their security environments, with a focus on responses to the Russia-Ukraine war. The analysis is innovative in exploiting both long-term historical data and especially collected national data on budget revisions within fiscal years. Recent increases in European defence burdens are comparable to those of European states during the 1930s. The increases are stronger for states that are geographically closer to Russia and, among those states, stronger for larger states. Smaller states tend to choose lower defence burdens, whether or not they are in an alliance. These findings challenge the traditional understanding of free riding within alliances and imply a need for defining new types of state behaviour. Two new behaviours are posited: binding for the case of Poland, and antagonistic free riding for the case of Hungary.

Local strain heterogeneity associated with Al/Si ordering in anorthite, CaAl2Si2O8, with implications for thermodynamic mixing behavior and trace element partitioning in plagioclase feldspars

Abstract Hard Mode IR powder absorption spectroscopy has been used to characterize local strain relaxation associated with Al/Si ordering in a suite of synthetic anorthite samples with structural states that vary from a high degree of Al/Si order through a metastable incommensurate structure at intermediate states of order to long-range order with I1 symmetry. The dominant feature accompanying the changing structural states is line broadening, which has been quantified by autocorrelation analysis and is attributed to local heterogeneous strain variations on a length scale of at least 1–5 unit cells. The autocorrelation results are consistent with contributions to the line broadening as being due to order parameters for both the C1 → I1 and I1 → P1 transitions, which couple biquadratically, λQod2Qdispl2. Close correlation with enthalpy variations from previously published calorimetric data indicates that the driving force for ordering can be understood in terms of elimination of strain fields arising from accommodating more or less rigid AlO4 and SiO4 tetrahedra in the feldspar framework. The metastable incommensurate structure of anorthite is closely analogous to the stable incommensurate structure that develops at intermediate compositions in the plagioclase solid solution, confirming that the same strain relaxation mechanism dominates the properties and behavior of all structural states across the solid solution. Elimination of strain heterogeneity by ordering on the basis of I1 symmetry determines the form of non-ideal mixing shown by the solid solution at high temperatures, and changes in elastic properties may contribute to a break in the slope of partitioning of trace elements between crystals and melt.

A Laboratory test aimed at demostrating the potential of an Interferometric Radar to estimate the Seismic Risk of damaged buildings

In the last decade, the use of interferometric Real Aperture Radar (RAR) to perform the survey of static and dynamical performance of civil structures, and estimate their vibration state and modal behaviour, for bridge monitoring, consolidated. In the case of urban buildings, due to the small amplitude of vibration of these structures, and the higher complexity of the radar survey, a few case studies have been published. Nonetheless, recent research [1] focused on the potential of measuring the frequency of vibration of a building after a seismic event to estimate the occurred damage using this non-invasive and remote sensing technique. The study here described reports the results of an experiment carried out to investigate the potential of this application through a laboratory setup. A framed metal structure, composed of bars fasten by bolts, representing a scaled reproduction of a civil building, is monitored using a portable K band (24 GHz) radar interferometer. The instrument is a prototype developed at CTTC which provides improved range resolution and displacement accuracy, with respect to the state of the art of commercial instruments. In the experiment, the structure is monitored by the radar step by step while its stiffness is decreased by loosening, in different points, the bolts constraining the structure. This procedure aim simulating an increasing damage. Simultaneously to the radar acquisitions, data from a setup of accelerometers mounted on the framed structure are also acquired. Despite the high environmental noise (radar clutter) caused by multiple reflections generated by the neighbour walls and furniture elements internal to the laboratory, the spectral analysis of the displacement samples retrieved from radar acquisitions and from the accelerometers confirm the expected behaviour. [1] Gonzalez-Drigo, R. et al., Assessment of Post-Earthquake Damaged Building with Interferometric Real Aperture Radar. Remote Sens. 2019, 11, 2830. https://doi.org/10.3390/rs11232830

Forecasting the rheological state properties of self-compacting concrete mixes using the response surface methodology technique for sustainable structural concreting.

It is structurally pertinent to understudy the important roles the self-compacting concrete (SCC) yield stress and plastic viscosity play in maintaining the rheological state of the concrete to flow. It is also important to understand that different concrete mixes with varying proportions of fine to coarse aggregate ratio and their nominal sizes produce different and corresponding flow- and fill-abilities, which are functions of the yield stress/plastic viscosity state conditions of the studied concrete. These factors have necessitated the development of regression models, which propose optimal rheological state behavior of SCC to ensure a more sustainable concreting. In this research paper on forecasting the rheological state properties of self-compacting concrete (SCC) mixes by using the response surface methodology (RSM) technique, the influence of nominal sizes of the coarse aggregate has been studied in the concrete mixes, which produced experimental mix entries. A total of eighty-four (84) concrete mixes were collected, sorted and split into training and validation sets to model the plastic viscosity and the yield stress of the SCC. In the field applications, the influence of the sampling sizes on the rheological properties of the concrete cannot be overstretched due to the importance of flow consistency in SCC in order to achieve effective workability. The RSM is a symbolic regression analysis which has proven to exercise the capacity to propose highly performable engineering relationships. At the end of the model exercise, it was found that the RSM proposed a closed-form parametric relationship between the outputs (plastic viscosity and yield stress) and the studied independent variables (the concrete components). This expression can be applied in the design and production of SCC with performance accuracies of above 95% and 90%, respectively. Also, the RSM produced graphical prediction of the plastic viscosity and yield stress at the optimized state conditions with respect to the measured variables, which could be useful in monitoring the performance of the concrete in practice and its overtime assessment. Generally, the production of SCC for field applications are justified by the components in this study and experimental entries beyond which the parametric relations and their accuracies are to be reverified.

The Great Game of Space: Space Political Adventurism and Battle for Superpower Status Beyond the Horizons

Wars will not be fought on the grounds in future, but explosions will occur beyond horizons. The subject of advanced strategies of Great Powers, space militarization, and political adventurism of China, USA, and Russia has been extensively inscribed in this research paper. The paper mainly reflects the political stratagem and space arms race of Russia, China, and the USA, which are combating each other for power status in orbits of space. As China and Russia challenge USA dominance in space, the USA seeks to weaponize space to maintain its supremacy and counter these rivals. The evolving international structure and world order are steering warfare into new dimensions, with space militarization posing nontraditional security threats like spying, surveillance, space debris, and satellite destruction. Technology has advanced to the point where states have developed sophisticated spy satellites and anti-satellite weapons capable of targeting other satellites from space or the ground. Despite international legal efforts and multilateral cooperation, major powers continue to expand their space arsenals, creating national security concerns. The study argues that international institutions have failed to curb the space arms race due to their ineffectiveness. Thus, there is a need for a shift in focus to find common ground and resolve this space security conflict. The paper provides a theoretical overview of the role of international institutions and state behavior in the international system. Using qualitative research techniques, the study conducts in-depth exploration through secondary data gathered from various articles, journals, reports, vlogs, videos, and magazines. Descriptive and explanatory research approaches are employed to achieve the research objectives.

Computational insights into solvent polarity associated excited state behaviour for 2-(1H-benzoimidazol-2-yl)−5-diethylamino-phenyl fluorophore

Inspired by the mesmerising charm emanating from the precisely controlled attributes displayed by 2-(1H-benzoimidazol-2-yl)−5-diethylamino-phenyl (HDP) and its derivatives in the domains of photochemistry and photobiology, our present undertaking predominantly focuses on exploring the complexities of light-triggered excited state reactions for HDP fluorophore dissolved in solvents with diverse levels of polarity. Initially, we performed molecular structure optimisation at various stages of the proton transfer process and collected data on bond length, bond angle, and core-valence bifurcation (CVB) index for the molecular framework. Subsequently, infrared (IR) vibrational spectra were analysed to evaluate the reinforcement of hydrogen bonds in different solutions. Furthermore, the investigation of orbital transitions and potential energy curves has led to the conclusion that the ESIPT process of HDP molecules is most likely to occur in nonpolar ccl4 solution, followed by chloroform solution; acetonitrile ranks last. In essence, the nonpolar aprotic solvents are more conducive to facilitating the ESIPT process. This research aims to contribute towards advancements in new luminescent materials and prove valuable in display technology and medical imaging fields while also promoting related technological development.

L -gap surface resonance at Pt(111): Influence of atomic structure, d bands, and spin-orbit interaction

Pt(111) hosts a surface resonance with peculiar properties concerning energy vs momentum dispersion and spin texture. At variance with the free-electron-like behavior of the L-gap Shockley-type surface states on the fcc(111) surfaces of Au, Ag, and Cu, it splits into several branches with distinct spin polarization around the center of the surface Brillouin zone Γ¯. Theoretical predictions based on density-functional theory vary depending on the particular functionals used. To clarify this issue, we investigate the atomic structure of Pt(111) by low-energy electron diffraction and the unoccupied electronic structure by spin- and angle-resolved inverse photoemission. The experimental results are backed by theoretical studies using different functionals, which show that the characteristics of the surface band depend critically on the lattice constant. From the analysis of the energy-dependent low-energy electron diffraction intensities, we derive structural parameters of the Pt(111) surface relaxation with high accuracy. In addition, we give an unambiguous definition of the nonequivalent mirror-plane directions Γ¯M¯ and Γ¯M¯′ at fcc(111) surfaces, which is consistent with band-structure calculations and inverse-photoemission data. Concerning the surface resonance at the bottom of the L gap, we identified a delicate interplay of several contributions. Lattice constant, hybridization with d bands, and the influence of spin-orbit interaction are critical ingredients for understanding the peculiar energy dispersion and spin character of the unoccupied surface resonance. Published by the American Physical Society 2024

KNOWLEDGE AND ATTITTUDES OF VETERINARY STUDENTS IN SERBIA TOWARD FARM ANIMAL WELFARE

In this study, veterinary students from the Faculty of Veterinary Medicine, University of Belgrade and Department of Veterinary Medicine, Faculty of Agriculture, University of Novi Sad were surveyed to evaluate their knowledge and attitudes toward farm animal welfare. Data were collected from 431 students by survey consisting of 39 closed-ended questions divided into two parts (demographic characteristics and a five-point Likert scale). Results showed that female students, students aged 18 to 21 years, from veterinary high schools, from urban areas, with mixed diets, who own pets, were predominated. Younger students and students from the Faculty of Veterinary Medicine, University in Belgrade agree significantly higher (p<0.001) that animal welfare is necessary for sustainable agriculture, food safety, biological functioning, emotional state, and natural behavior, as well as zootechnical procedures and rearing systems impairing the welfare of farm animals compared with students of the final year of studies, and from Department of Veterinary Medicine, Faculty of Agriculture in Novi Sad. Female students, and younger students, from urban areas, who own pets, have more concerned attitudes regarding farm animal welfare (p<0.001). The findings of this study confirm that attitudes toward farm animal welfare are not homogeneous and are associated with students’ demographic characteristics. Also, results suggest that more attention should be paid to the curriculum and program to indirectly improve the welfare of farm animals.

Critical state behaviour of an unsaturated kaolin mixture

In this paper, a series of suction-controlled triaxial tests were conducted to investigate the hydromechanical behaviour of an unsaturated kaolin mixture. The studied variables included the mean net stress, suction, and initial dry density. The suction was controlled over a wide range – in the span of 0–390 MPa using the axis translation method and the vapour equilibrium technique, aiming to holistically study the mechanical response of unsaturated soils. The discussion focused on the critical state behaviour and dilatancy characteristics of the tested soil. The experimental results indicate that the ductility of the soil decreases and shifts towards brittleness with increasing suctions. The critical state stress ratio (Ma) of the soil exhibits a significant increase with suction, and this increase becomes more pronounced with higher initial dry density. Conversely, the impact of suction on the critical state line in the specific volume-mean net stress plane (v-lnpnet plane) diminishes with higher initial dry density. Furthermore, suction notably influences the stress-dilatancy relationship of kaolin mixtures, while the effect of confining pressure appears to be marginal. The influence of suction on the stress-dilatancy relationship primarily stems from its impact on the critical stress ratio (Ma), which can be normalized by dividing the stress ratio by the critical state stress ratio. Lastly, the stress-dilatancy equation of the modified Cam-clay model is extended to capture the effect of suction on the dilatancy characteristics of unsaturated soils.