Physical Systems Research Articles

Electronic security system installation skills requisite for self-reliance of radio-television and electronic work students in technical colleges in Rivers State

The study determined the electronic security system installation skills requisite for self-reliance of radio-television and electronic work students in technical colleges in Rivers State. A descriptive Survey design was used for the study. The population for the study was 30 teachers and 185 NTC III students in technical colleges in Rivers state. The study was carried out in Rivers state. A Structured questionnaire was used as instruments for data collection. Two research questions and two null hypotheses guided the study. Cronbach Alpha method was used for the reliability of the instrument which yielded a coefficient of 0.75. Mean and standard deviation were used to analyze the data for answering research questions, while t- test was used to test the hypotheses of no significant difference at 0.05 level of significant. The study found out that: the acquisition of physical access control system skills will enable the radio-television and electronic work students to be self-reliance upon graduation and the gaining of video surveillance system skills will also make the radio-television and electronic work students in technical colleges to be more effective and efficient in the delivery of their jobs.

Digital twin applications for predicting and controlling vibrations in manufacturing systems

In Recent times, Digital Twin (DT) technology has emerged as an innovative tool for the enhancement of the efficiency and reliability of manufacturing systems, through the creation of virtual replicas of physical assets, systems and processes. As vibrations in machines and tools can lead to reduced product quality, increased wear and tear, as well as unplanned downtimes, this article explores the application of digital twins for predicting and controlling vibrations in manufacturing systems. The integration of digital twins assists in addressing these challenges through the provision of insights into vibration dynamics, enabling proactive maintenance, and optimizing system performance. It examines how sensor data and advanced computational models converge to simulate and predict vibration behavior in real time. Moreover, the role of artificial intelligence and machine learning in analyzing vibration patterns and prescribing corrective measures is discussed. The article also presents case studies that highlight successful implementations of digital twins in diverse manufacturing contexts, showcasing measurable improvements in productivity and system reliability. In addition, the research identifies key challenges, including data integration complexities, high computational requirements, and cost implications, that manufacturers must address to fully leverage the potential of digital twins. By synthesizing these insights, the paper provides a comprehensive framework for researchers and practitioners seeking to harness digital twin technology for vibration management in manufacturing environments.

Chiral Locomotion Transitions of an Active Gel and Their Chemomechanical Origin.

Transitions between chiral rotational locomotion modes occur in a variety of active individuals and populations, such as sidewinders, self-propelled chiral droplets, and dense bacterial suspensions. Despite recent progress in the study of active matter, general principles governing rotational chiral transition remain elusive. Here, we study, experimentally and theoretically, rotational locomotion and its chiral transition in a 2D polyacrylamide (PAAm)-based BZ gel driven by Belousov-Zhabotinsky reaction-diffusion waves. Analysis reveals that the phase difference (Δφ) between orthogonal components of kinematic quantities, such as chemomechanical force, displacement, and velocity, determines rotational chirality, i.e., chiral locomotion transition occurs when Δφ changes sign. This criterion is illustrated with a kinematic equation, which can be applied to biological and physical systems, including super-rotational/superhelical locomotion reported recently during E. gracilis swimming and sperm navigation. This work has potential applications for the design of functional materials and intelligent robots.

Risk analysis and protection in case of intrusion of nuclear facilities

Abstract Physical protection systems (PPSs) are designed to counter and neutralize any theft or sabotage attempts carried out against a given site. PPS designs are crucial, requiring rigorous analysis and evaluation to ensure their reliability, sustainability and optimal security. This paper assumes a Hypothetical Nuclear Research Center (HNRC) for PPS analysis and evaluation. This work will determine the PPS’s most vulnerable path elements, by demonstrating expected intrusion attack scenarios by taking advantage of the HNRC’s design weaknesses. Also, this work determines the threats resulting from adversary intrusion through the weakness path elements located at the nuclear site. Additionally, this paper develops an analytical methodology for this evaluation and risk assessment, by using the Systematic Analysis of Vulnerability to Intrusion (SAVI) computer program. Through constructing adversary sequence diagrams (ASDs), SAVI can easily identify the HNRC’s most vulnerable paths, pinpointing the areas which require the most attention. Alongside SAVI is the quantitative risk analysis method - the Dai et al. Model – which can calculate the effectiveness and risk of the PPS itself by measuring its degree of uncertainty using effectiveness entropy. To comply with effectiveness and risk standards, this work also introduces security system upgrade processes and determines the optimal security solution for the HNRC.

Influence of Joule heating and slip on 3D MHD rotating nanoliquid flow with radiation, viscous dissipation, Soret and Dufour effects

Purpose The purpose of this study is to explore the impact of Joule heating, slip conditions, Dufour and Soret effects on three-dimensional magneto-convection of nanoliquid over a rotating surface in the existence of thermal radiation, viscous dissipation and internal heat generation/absorption. Design/methodology/approach The considered physical system is modelled by a set of partial differential equations (PDEs) with conditions at surface. Then, the nonlinear PDEs are altered into a system of ordinary differential equations and they are solved numerically by the Runge−Kutta−Fehlberg method. Plotting the collected velocity, temperature and solute concentration characteristics allows one to see how relevant parameters affect the results. Calculations are made for skin friction and the rate of heat and mass transfer. Findings The outcomes are portrayed in the form of tables and graphs with a wide range of parameter involved in the study. It is observed that the local thermal energy transfer rate enriches on increasing the value of both thermal and solute slips. The solutal slip parameter suppresses the solute transport rate and thermal slip supports the solute transport. Practical implications Combining the Dufour and Soret effects is used in oil reservoirs, binary alloy solidification and isotope separation in mixtures of gases. Heat exchangers, nuclear reactors and thermal engineering can all benefit from the usage of nanofluid with Joule heating. Social implications This study is mainly useful for thermal sciences and chemical engineering. Originality/value The investigation of the effects of slip circumstances and Joule heating on magnetohydrodynamic rotating nanoliquid stream with thermal radiation and cross-diffusion makes this work unique. The discoveries produced are valuable and distinctive, and they have applications in many areas of thermal science and technology.

Critical spin chains and loop models with $PSU(n)$ symmetry

Starting with the Ising model, statistical models with global symmetries provide fruitful approaches to interesting physical systems, for example percolation or polymers. These include the O(n)O(n) model (symmetry group O(n)O(n)) and the Potts model (symmetry group S_QSQ). Both models make sense for n,Q∈ \mathbb{C}n,Q∈ℂ and not just n,Q∈ \mathbb{N}n,Q∈ℕ, and both give rise to a conformal field theory in the critical limit. Here, we study similar models based on the group PSU(n)PSU(n). We focus on the two-dimensional case, where the models can be described either as gases of non-intersecting orientable loops, or as alternating spin chains. This allows us to determine their spectra either by computing a twisted torus partition function, or by studying representations of the walled Brauer algebra. In the critical limit, our models give rise to a CFT that exists for any n∈\mathbb{C}n∈ℂ and has a global PSU(n)PSU(n) symmetry. Its spectrum is similar to those of the O(n)O(n) and Potts CFTs, but a bit simpler. We conjecture that the O(n)O(n) CFT is a \mathbb{Z}_2ℤ2 orbifold of the PSU(n)PSU(n) CFT, where \mathbb{Z}_2ℤ2 acts as complex conjugation.

Transmission of photonic entangled states encoded via eigenstates of photon-number parity operator

The transfer of quantum entangled states is of fundamental interest in quantum physics and plays an important role in quantum information processing, quantum communication, and quantum technology. Here, we propose a scheme to transfer quantum entangled states of two photonic qubits by utilizing four microwave cavities coupled to a superconducting qutrit (a three-level quantum system). The photonic qubits are encoded using two orthogonal eigenstates of the photon-number parity operator with eigenvalues ± 1, which allows for various encodings for the photonic qubits. The employment of four cavities at distinct frequencies effectively reduces the inter-cavity crosstalk. The utilization of only a single superconducting qutrit as the coupler significantly reduces the circuit resources. The entanglement transfer can be completed in just one step, making this scheme remarkably efficient. During the state transfer process, the third energy level of the coupler qutrit remains unoccupied, and thus decoherence from this level is diminished. Our numerical simulations demonstrate that within current circuit quantum electrodynamics technology, one can achieve high-fidelity transfer of the entangled states of two photonic qubits encoded via squeezed vacuum states and cat states. Our scheme possesses generality and can be applied to accomplish the same task in a variety of physical systems.

Breather, lump and other wave profiles for the nonlinear Rosenau equation arising in physical systems

This work explores the mathematical technique known as the Hirota bilinear transformation to investigate different wave behaviors of the nonlinear Rosenau equation, which is fundamental in the study of wave occurrences in a variety of physical systems such as fluid dynamics, plasma physics, and materials science, where nonlinear dynamics and dispersion offer significant functions. This equation was suggested to describe the dynamic behaviour of dense discrete systems. We use Mathematica to investigate these wave patterns and obtained variety of wave behaviors, such as M-shaped waves, mixed waves, multiple wave forms, periodic lumps, periodic cross kinks, bright and dark breathers, and kinks and anti-kinks. These patterns each depict distinct qualities and behaviors of waves, offering insights into the interactions and evolution of waves. The results found that free parameters have a substantial impact on travelling waves, including their form, structure, and stability. With the aid of this software, we potray the dynamics of these waves in 3Ds, contours and densities plots, which enables us to comprehend how waves move and take on various forms. The novel component is the application of Hirota’s bilinear approach to generate new form of solutions as highlighted above, analyse their interactions, and give better visualisations, which goes beyond prior soliton-focused investigations of the Rosenau problem. All things considered, our work advances our understanding of waves and nonlinear systems and demonstrates the value of mathematical techniques for understanding intricate physical phenomena. These results may have implications for a wide range of fields, including environmental science, engineering, and physics.

Experimental simulation of daemonic work extraction in open quantum batteries on a digital quantum computer

Abstract The possibility of extracting more work from a physical system thanks to the information obtained from measurements has been a topic of fundamental interest in the context of thermodynamics since the formulation of the Maxwell's demon thought experiment. We here consider this problem from the perspective of an open quantum battery interacting with an environment that can be continuously measured. By modeling it via a continuously monitored collisional model, we show how to implement the corresponding dynamics as a quantum circuit, including the final conditional feedback unitary evolution that allows to enhance the amount of work extracted. By exploiting the flexibility of IBM quantum computers and by properly modelling the corresponding quantum circuit, we experimentally simulate the work extraction protocol showing how the obtained experimental values of the daemonic extracted work are close to their theoretical upper bound quantified by the so-called daemonic ergotropy. We also demonstrate how by properly modelling the noise affecting the quantum circuit, one can improve the work extraction protocol by optimizing the corresponding extraction unitary feedback operation.

Can Molecular Systems Learn?

AbstractResearch across various disciplines shows the benefits of learning and memory for gaining functionality and improving performance. It is increasingly clear that learning and memory can be found in both physical and virtual systems, from intelligent life forms to machines, simple organisms, and even designed chemical systems. We are interested in understanding to what extent physical embodiments of these processes can be synthesized and engineered from the bottom up by using molecular components. In this perspective, we raise and attempt to answer conceptual questions about supramolecular systems as the smallest units capable of learning. We define learning as a process where a complex system of interacting components modifies itself in response to an applied stress or stimulus, resulting in structural changes and information gain. We highlight the potential of systems chemistry and molecular networks to design systems that meet this definition by encoding, decoding, and storing information as memory within the system′s composition. Understanding the physical basis of molecular memory and learning could inform the development of materials and chemical systems that autonomously acquire new properties in response to their environment. This could also provide insights for next‐generation computing and physical, rather than virtual, learning systems.

Development of Hybrid Vehicle

Model-Based Design can be applied in the development of a hybrid electric vehicle system. The paper explains how Model-Based Design begins with defining the design requirements that can be traced throughout the development process. This leads to the development of component models of the physical system, such as the power distribution system and mechanical drive line. We also show the development of an energy management strategy for several modes of operation including the full electric, hybrid, and combustion engine modes

Studying the 3d Ising surface CFTs on the fuzzy sphere

Boundaries not only are fundamental elements in nearly all realistic physical systems, but also greatly enrich the structure of quantum field theories. In this paper, we demonstrate that conformal field theory (CFT) with a boundary, known as surface CFT in three dimensions, can be studied with the setup of fuzzy sphere. We consider the example of surface criticality of the 3d Ising CFT. We propose two schemes by cutting a boundary in the orbital space and the real space respectively to realise the ordinary and the normal surface CFTs on the fuzzy sphere. We obtain the operator spectra through state-operator correspondence. We observe integer spacing of the conformal multiplets, and thus provide direct evidence of conformal symmetry. We identify the ordinary surface primary oo, the displacement operator \mathrm{D}D and their conformal descendants and extract their scaling dimensions. We also study the one-point and two-point correlation functions and extract the bulk-to-surface OPE coefficients, some of which are reported for the first time. In addition, using the overlap of the bulk CFT state and the polarised state, we calculate the boundary central charges of the 3d Ising surface CFTs non-perturbatively. Other conformal data obtained in this way also agrees with prior methods. We also discuss future directions, such as special surface CFT, cone defects, and surfaces of other bulk CFTs.

From a testing system to a system for monitoring the level of physical fitness: tasks and functions of assessing the physical fitness of children and youth at the national level

Regular monitoring of physical fitness indicators in youth is critical. Objective. To explore expert perspectives on the main tasks and functions of the physical fitness assessment system for schoolchildren and students. Methodology. A survey of experts (n=17) from six regions of Ukraine was conducted. The questionnaire included open-ended and closed questions addressing the specifics of physical fitness testing in children and youth, as well as opportunities for its improvement, particularly regarding the primary tasks of testing. Descriptive statistics were used to analyze quantitative data. Results. Experts identified five main problem areas that the physical fitness assessment system should address. Monitoring the dynamics of physical fitness in Ukrainian children and youth. Collecting data to form conclusions and recommendations. Assisting educators in implementing physical education goals in educational institutions. Providing opportunities for children to realize their potential. Encouraging children and youth to pursue further self-improvement, identified as the most important task. Some responses highlighted the role and significance of testing as part of a system for observing parameters related to health and quality of life, including monitoring physical fitness levels, motor activity, health, and the development of sports talent in students. Experts emphasized the importance of a testing system in addressing health preservation, wellness, and educational goals within physical education. Conclusions. The tasks addressed by the youth physical fitness testing system partially meet the needs of the educational sector, particularly in physical education. Considering current demands, it is appropriate to deepen the understanding of fitness assessment as a multifaceted phenomenon closely linked to health and influenced by lifestyle and environmental factors. This requires the development of a comprehensive monitoring system for physical fitness and the engagement of specialists in discussions of this concept.

Discipline "Extreme sports" in the physical education system

Extreme sports are a special type of activity that is associated with a high level of risk, physical and psychological challenges. They attract many people who seek to test the limits of their capabilities, experience sharp emotions and adrenaline. Extreme sports are gradually taking an important place in the physical education system, because they develop physical endurance, psychological resilience and form a responsible attitude towards a healthy lifestyle in young people. In educational institutions and sports institutions, extreme activities can be integrated as a supplement to traditional physical education programs. It is obvious that extreme sports are very interesting, exciting types of recreation and are becoming more and more popular among different segments of the population every year, no matter what. Today, Ukrainian students are increasingly participating in many international competitions. It is obvious that extreme sports will gradually develop. The task of the state is to make it as safe as possible for participants and prevent uncontrolled use and destruction of natural tourist resources. Non-Olympic sports are an important component of extreme sports, characterized by a high level of risk, physical exertion and specific technical training. These sports are usually not included in the Olympic Games program, but are widely popular among young people and extreme sports enthusiasts.

Organization and condust of physical education and special physical training of service members in the armed forces of Spain at the present stage

This article is dedicated to the organization and conduct of physical education and special physical training of service members in the Armed Forces of Spain at the present stage, as well as the possibilities of adapting this experience for the Ukrainian Armed Forces. The article analyzes the main methodologies and approaches used in Spain, compares the physical training systems in both countries, and provides recommendations for implementing effective elements of the Spanish system in Ukrainian military practice. The implementation of these methodologies can contribute to improving the level of physical training of Ukrainian service members and enhancing their combat readiness. The organization of physical education and special physical training of service members in the Armed Forces of Spain at the present stage is based on high requirements for the physical readiness of personnel, which is a necessary condition for the effective execution of combat tasks and ensuring national security. Service members undergo specialized physical training that includes various training programs developed considering the requirements of military service and the soldiers' physical capabilities. The primary focus is on developing endurance, strength, speed, coordination, and flexibility, which are essential for performing physically demanding tasks in combat conditions. The Spanish military education system actively uses modern methods and technical means to monitor and assess the physical condition of service members, allowing for an individual approach to each soldier and ensuring the most effective training depending on their needs.

Cyber–Physical System Attack Detection and Isolation: A Takagi–Sugeno Approach

Cyber–Physical System Attack Detection and Isolation: A Takagi–Sugeno Approach

Thermodynamics of Morphogenesis: Beading and Branching Pattern Formation in Diffusion-Driven Salt Finger Plumes

Spontaneous pattern formation is a universal phenomenon that occurs in purely physical systems, biology, and human societies. Salt fingering due to differential diffusion of heat and salt in seawater is a typical example, although the general principle that governs pattern formation remains unknown. We show through simple experiments injecting a salt solution into a sucrose solution of equal density that a salt finger exhibits characteristic pattern transitions depending on the injection flow rate. When the rate increases, a linear finger starts meandering, branching, and multiple branching, whereas when the rate is decreased, it produces a beading pattern. These morphological instabilities and associated pattern formation are caused by a local accumulation of kinetic energy that minimizes the flow resistance and maximizes the energy dissipation in the final steady state. We suggest that this energy accumulation mechanism governs a wide variety of pattern formation phenomena in non-equilibrium systems, including morphogenesis of abiotic protocells.

Blow-Up of Solutions in a Fractionally Damped Plate Equation with Infinite Memory and Logarithmic Nonlinearity

In this article, we consider the dynamics of a viscoelastic plate equation with internal fractional damping, a nonlinear logarithmic source, and infinite memory effects. The existence of a local weak solution is shown effectively through the framework of semigroup theory. Furthermore, we show that the blow-up in finite time of the local solution may occur under specific conditions and is demonstrated within the development of a suitable Lyapunov functional. Our result offers an insight into the challenges presented by this class of equations and their relevance to physical systems.

Application research on mechanical assessment and training based on intelligent physical training system in the rehabilitation of athletes’ ankle injuries

As the only hinge connection between human body and the ground, ankle joint plays an important role in sports. Based on the theory of rehabilitation medicine, this paper puts forward an intelligent physical training system integrating mechanical evaluation and training functions, and applies it to the rehabilitation of athletes’ ankle injuries. The system adopts virtual reality (VR) technology, realizes active ankle rehabilitation training through high-precision sensors and advanced computer simulation technology, and provides accurate evaluation, monitoring and personalized training scheme for ankle rehabilitation. The system creates an immersive training environment for athletes by simulating real sports scenes and processes. The experimental results show that the system is excellent in training convergence speed and performance, and the error is small. Compared with the traditional algorithm, the accuracy is improved by 19.27%. The main contribution of this paper is that the intelligent physical training system integrating mechanical evaluation and training is applied to the rehabilitation of athletes’ ankle injuries, and good rehabilitation results have been achieved.

Kohn-Sham inversion for open-shell systems.

Methods based on density-functional theory usually treat open-shell atoms and molecules within the spin-unrestricted Kohn-Sham (KS) formalism, which breaks symmetries in real and spin space. Symmetry breaking is possible because the KS Hamiltonian operator does not need to exhibit the full symmetry of the physical Hamiltonian operator, but only the symmetry of the spin density, which is generally lower. Symmetry breaking leads to spin contamination and prevents a proper classification of the KS wave function with respect to the symmetries of the physical electron system. Formally well-justified variants of the KS formalism that restore symmetries in real space, in spin space, or in both have been introduced long ago, but have rarely been used in practice. Here, we introduce numerically stable KS inversion methods to construct reference KS potentials from reference spin-densities for all four possibilities to treat open shell systems, non-symmetrized, spin-symmetrized, space-symmetrized, and fully-symmetrized. The reference spin-densities are obtained by full configuration interaction and high-level coupled cluster methods for the considered atoms and diatomic molecules. The decomposition of the total energy in contributions such as the non-interacting kinetic, the exchange, and the correlation energy is different in the four KS formalisms. Reference values for these differences are provided for the considered atoms and molecules. All KS inversions, except the fully symmetrized one, lead in some cases to solutions violating the Aufbau principle. In the purely spin-symmetrized KS formalism, this represents a violation of the KS v-representability condition, i.e., no proper KS wave functions exist in those cases.