Oscillatory Systems Research Articles

A Radiation Heating-Based Oscillatory Polymerase Chain Reaction System for Detecting Donkey-Hide Gelatin

Abstract Polymerase chain reaction (PCR) is a biochemical technique for copying DNA by repeatedly changing the temperature of nucleic acid samples. In this study, we aim to create an oscillatory PCR system with a short reaction time, which could have significant practical implications. The device uses an electromechanical module with a servo motor and a homemade heating–cooling system that combines a halogen lamp, a Peltier element, a cooling fin, and a blower fan. We code the motor program to control the reaction chamber moving back and forth in the infrared thermal cycling system. The system uses one infrared lamp for heating and one Peltier element/thermal dissipation fins/blower fan for cooling to shorten the overall reaction time of the thermal process. Results show that using the radiant heating and convection cooling method and a micro-sample of 10 μL to perform a PCR, the total time spent is 35 min, which saves about 1 h compared to commercially available PCR instruments. The proposed PCR approach could specifically detect donkey-hide gelatin (DHG) made from donkey skin, offering a rapid and cost-effective solution. Therefore, our device has the advantages of easy manufacturing, low cost, and rapid temperature ramping rate for PCR.

Phylogeography and genetic diversity of Ulmus elongata (Ulmaceae), a Tertiary relict tree with extremely small populations (PSESP)

BackgroundAssessing the current status and identifying the mechanisms threatening endangered plants are significant challenges and fundamental to biodiversity conservation, particularly for protecting Tertiary relict trees and plant species with extremely small populations (PSESP). Ulmus elongata (Ulmus, Ulmaceae) with high values for the ornamental application, is a Tertiary relict tree species and one of the members from PSESP in China. Currently, the wild populations of U. elongata have been threatened by excessive deforestation and urbanization, but limited knowledges of its genetic diversity seriously hinder conservation efforts. Therefore, a further study on the genetic diversity and drivers of genetic pattern in U. elongata is crucial for preserving genetic resources and can serve as a reference for other Tertiary relict plants and PSESP under climate change.ResultsHere, a total of 12 populations from 70 individuals of U. elongata were collected covering its geographical distribution in China. Utilizing chloroplast genome datasets, we found that U. elongata exhibited remarkably low nucleotide diversity and gene flow (π = 0.00013, Nm = 0.03). Analysis of molecular variance (AMOVA) showed that genetic variation in U. elongata occurs mainly between eight clades (60.95%). The Mantel tests indicated a significant correlation between genetic differentiation and geographical distances (r = 0.3777, p < 0.05) in U. elongata populations. A notable phylogeographic structure was identified in U. elongata, comprising eight distinct haplogroups (NST = 0.917, GST = 0.876, p < 0.05), which was attributed to the global cooling in the East Asia and Quaternary climate oscillations.ConclusionsOverall, our study using Ulmus elongata as a representative supported the hypothesis that plants belonging to Tertiary relict species and PSESP simultaneously exhibits significantly lower genetic diversity compared to those are either Tertiary relict species or PSESP individually. Furthermore, the low genetic diversity and significant genetic differentiation in U. elongata populations can be primarily ascribed to a combination of factors, including habitat fragmentation resulting from human activities, populations contraction during LGM and small population sizes. This provides a crucial foundation for guiding conservation efforts and implementing management strategies for other Tertiary relict tree species and PSESP. Our findings also provide evidence for the important roles of East Asian monsoon system and climate oscillations in shaping the phylogeographic pattern in subtropical broad-leaved forests.

Aptamer-Driven Multifunctional Nanoplatform for Near-Infrared Fluorescence Imaging and Rapid In Situ Inactivation of Salmonella typhimurium.

Salmonella typhimurium (S. typhimurium) is a prominent pathogen responsible for intestinal infections, primarily transmitted through contaminated food and water. This underscores the critical need for precise and biocompatible technologies enabling early detection and intervention of bacterial colonization in vivo. Herein, a multifunctional nanoplatform (IR808-Au@ZIF-90-Apt) was designed, utilizing an S. typhimurium-specific aptamer to initiate cascade responses triggered by intracellular ATP and GSH. The nanoplatform precisely targets S. typhimuriumvia aptamer recognition, promoting bacterial aggregation through nanoparticle sedimentation in an oscillatory system. Furthermore, the intelligent nanoplatform significantly enhances the sensitivity of S. typhimurium detection based on near-infrared (NIR) fluorescence signals, achieving a detection limit as low as 2 CFU mL-1. Additionally, in situ NIR irradiation was applied at the 30 min peak of fluorescence detection, enabling rapid and irreversible inactivation of S. typhimurium through the synergistic effects of photothermal and photodynamic effects. Importantly, in a mouse model of intestinal infection, the nanoplatform successfully detected early S. typhimurium colonization and achieved highly efficient in situ inactivation without adversely affecting the major organs. In conclusion, the nanoplatform achieved precise localized detection and in situ inactivation of S. typhimurium, offering valuable insights for disease surveillance and epidemiological studies, with promising implications for food safety and public health.

A new vision of the Adriatic Dense Water future under extreme warming

Abstract. We use the Adriatic Sea and Coast (AdriSC) kilometer-scale atmosphere–ocean model to assess the impact of a far-future extreme-warming scenario on the formation, spreading, and accumulation of North Adriatic Dense Water (NAddW) over the entire basin, including the Jabuka Pit accumulation site, and Adriatic Deep Water (AdDW) over the Southern Adriatic Pit (SAP). Our key findings differ from previous studies that used coarser Mediterranean climate models and did not update the thresholds for dense-water and deep-water definitions to account for the far-future background density changes caused by warmer sea surface temperatures. We show that surface buoyancy losses at NAddW generation sites, driven by evaporation, are expected to increase by 15 % under extreme warming, despite a 25 % reduction in the intensity and spatial extent of Bora winds. As a result, future NAddW formation will remain similar to present conditions. However, the volume of dense water in the Jabuka Pit will decrease due to the increased far-future stratification. Additionally, dense-water transport between the Jabuka Pit and the deepest part of the SAP will stop, as future NAddW will be lighter than the AdDW. Regarding Ionian–Adriatic exchanges, extreme warming will not affect the impact of the bimodal oscillation system on the Adriatic salinity variability, but future AdDW dynamics will be determined by density changes in the northern Ionian Sea. Our findings highlight the complexity of climate change impacts on Adriatic atmosphere–ocean processes and the importance of high-resolution models for more accurate far-future projections in the Adriatic Sea.

Amplitude and frequency of human gait synchronization with a machine oscillator system

Humans sometimes synchronize their steps to mechanical oscillations in the environment (e.g., when walking on a swaying bridge or with a wearable robot). Previous studies have discovered discrete frequencies and/or amplitudes where individuals spontaneously synchronize to external oscillations, but these parameters are often chosen arbitrarily or for convenience of a successful experiment and are sparsely sampled due to time constraints on subject availability. As a result, the parameter space under which human gait synchronization occurs is still relatively underexplored. Here we systematically measure synchronization over a broad range of parameters in machine oscillations, applied vertically near the body center of mass during walking. Two complementary experiments were utilized to characterize the amplitudes and frequencies where subjects’ gait matched the oscillation frequency within ± 0.02 Hz for at least 80% of 20 consecutive steps (i.e., synchronization). Individuals were found to synchronize at lower amplitudes and in less time when the oscillation frequency was nearer their baseline step frequency, as well as over a broader range of frequencies during larger oscillation amplitudes. Subjects also had a greater tendency to synchronize with oscillation frequencies below (rather than above) their baseline step frequencies. The results of this study provide a comprehensive mapping of parameters where synchronization occurs and could inform the design of exoskeletons, rehabilitation devices and other gait-assistive technologies.

Irreversible Dynamics of Nonequilibrium System of Cavity Optomechanical Coupled Oscillators

Irreversible Dynamics of Nonequilibrium System of Cavity Optomechanical Coupled Oscillators

Algorithm performance study pulse suppression of auto-oscillation phenomena in the electromechanical system of the electric traction drive in braking mode electric traction drive system in braking mode by methods of simulation modeling

Research relevance. Modes accompanied by increased sliding of a wheel with negative viscous friction, characterized by reduction of friction force at growth of sliding speed, can arise at the movement of the vehicle. In these cases, a loss of stability may occur, resulting in the excitation of auto-oscillation phenomena in the electromechanical system (road-wheel-mechanical drive-electric motor). The emergence of this process sharply increases the dynamic load of the system, which can lead to its failure or breakdown. As a consequence, the development of suppression methods of auto-oscillation phenomena is considered to be an urgent task.Purpose of the research. Verification of operability and efficiency of the suppression method of auto oscillations in the electromechanical system of wheel drive during braking of the vehicle.Materials and Methods. With the help of Lyapunov’ function analysis for the electromechanical system of wheel drive the suppression method of auto oscillation phenomena is substantiated. The study of the algorithm performance has been carried out with the use of MATLAB Simulink program complex.Research results. The operability and efficiency of the algorithm is proved by methods of simulation mathematical modeling, which allows its further use in the development of traffic control systems. In case of braking of the vehicle equipped with antilock braking system with the function of suppression of auto oscillations on a slippery support base the reduction of amplitudes oscillation of angular velocities of wheels by 80% and braking moments by 96% is observed. When this vehicle is braked on a high adhesion base, the amplitudes are reduced by 98% in angular velocities and 81% in torques. In simulation modeling of vehicle braking dynamics on a support base with low adhesion properties it has also been shown that in these cases the evasive maneuver can be performed, which indicates on the increase in controllability and active safety of the vehicle.Conclusion. The practical value of the study lies in the possibility of using the developed algorithm for suppressing auto oscillations in practical application as part of vehicle control systems. The developed algorithm can be used on vehicles of different classes equipped with individual traction electric drive of driving wheels.

Effects of ambient noise on quantum speed limit time and quantum discord dynamics of a double ‘gravitational cat state’ system

The exploration of the quantum nature of gravity has always been the focus of academic research. In this work, we consider a double ‘gravitational cat state’ quantum system consisting of a pair of massive particles coupled by gravitational interaction confined in their respective double potential Wells. Specifically, we model the double ‘gravitational cat state’ system as a two-qubit system, consider that the system is initially in the two-qubit Bell state, and study the influence of stable classical field and decayed field noise on the quantum speed limit time (QSLT) and trace distance discord (TDD) dynamics of the double ‘gravitational cat state’. The results show that the QSLT can be controlled by changing the parameters of the system and the environment, and the quantum state dynamics evolution of the system with massive particles can be accelerated. The quantum state evolution can be accelerated by increasing the gravitational coupling intensity between the two massive particles. The decay rate of the decaying field can also regulate the QSLT of the system to a certain extent, so as to accelerate the quantum state evolution, as shown in Fig. 8(a). Under the influence of decaying field noise, it is worth noting that the intensity of gravitational coupling affects the frequency of quantum discord oscillations in this two-particle system. The QSLT shows an oscillating trend with time, rapidly increases to a certain value in a short period of time, then begins to decline, and then oscillates until it reaches a stable value. That is to say, the evolution of quantum states goes through an oscillatory cycle of first deceleration and then acceleration until the evolution rate becomes stable after a certain period of time. At the same time, there are similar oscillations in the dynamics of quantum discord. Moreover, by comparing these two, it is found that the QSLT decreases in the process of the system's quantum discord increase. When the discord oscillation has regularity, QSLT tends to a certain value, and the quantum discord of the double ‘gravitational cat state’ system has a certain relationship with the QSLT, as shown in Fig. 8(b). In other words, quantum discord will affect the rate of quantum state evolution to some extent, and the increase of quantum discord between systems will be more conducive to the evolution of quantum states.

The adaptive suppression method for high-frequency oscillations in renewable energy generation system integrated with multi-terminal MMC-HVDC

The adaptive suppression method for high-frequency oscillations in renewable energy generation system integrated with multi-terminal MMC-HVDC

Sustained Oscillations in Modern AC Distribution Systems With High DER Infiltration

Sustained Oscillations in Modern AC Distribution Systems With High DER Infiltration

Effects of pulse amplitude modulation on relaxation oscillations in the Duffing system

Effects of pulse amplitude modulation on relaxation oscillations in the Duffing system

Oscillation Control of a Double-Pendulum Overhead Crane Using Positive and Negative Input Shaping Techniques

A double-pendulum overhead crane system exhibits significant nonlinearity and is classified as an under-actuated system, making control more complex. This study focuses on designing a robust shaper to effectively mitigate oscillations in such systems. Two robust shapers, which are Zero Vibration Derivative (ZVD) and Negative Equal-Magnitude (NEM), are considered. These are obtained by convolving two input shapers that are designed based on the hook and payload oscillation frequencies. Matlab simulations are utilized to evaluate the performance of the shapers, using a nonlinear dynamic model of the crane to assess their effectiveness. Simulation results show that the ZVD shaper has a better performance in oscillation reduction, with 81% and 76% reductions for the hook and payload oscillations, respectively. In addition, the ZVD provides the lowest mean average error by achieving 87% and 83% reductions in the hook and payload as compared to the case with an unshaped input. However, the NEM shaper provides less delay in the trolley response.

Estimating the internal friction and the rotational inertia of a homemade oscillatory system

Abstract In this work, we apply the dynamics of translation and rotation to a real system-a homemade mass-spring system composed of a cart-in which the rolling without slipping constraint of the cart's wheels may be violated at any moment. In this case, we demonstrate how modeling combined with video analysis can be powerful in determining the constraint forces acting on the system. In this case, the translational and rotational accelerations are determined, and the temporal behavior of all constraint forces can be identified. Initially, we show how rotations with slipping of the cart's wheels at the return points of the system's motion impact the system's kinematics. Finally, we apply the developed methodology to estimate the system's internal friction and rotational inertia. The estimates are compared with results from the literature and with a theoretical limit, in the case of rotational inertia, achieving good agreement.

Interactions and Oscillatory Dynamics of Chemically Powered Soft Swimmers.

We report the interactions and dynamics of chemically powered soft swimmers that undergo autonomous oscillatory motion. The interaction of autonomous entities is the basis for the development of collective behaviors among biological organisms. Collective behaviors enable organisms to efficiently attain food and coordinate against threats. The basis of these behaviors is the interaction between nearest neighbors. Mimicking these interactions in artificial systems would enable their organization for the performance of complex tasks. Oscillatory phenomena are also ubiquitous in nature. Hence artificial oscillatory systems can serve as the most direct mimics and models of many biological systems. In this work, we report the interactions and dynamics of oscillatory swimmers propelled by the nonlinear oscillatory Belousov-Zhabotinsky (BZ) reaction. Individually, these swimmers displace by undergoing nonfully reciprocal oscillatory motion in conjunction with the BZ reaction. We find that, in addition to their individual oscillatory motion, multiple BZ swimmers exhibit successive oscillatory changes in their inter swimmer distance. This oscillatory attraction and repulsion between adjacent swimmers occurs in conjunction with the BZ waves and oxidation state of the catalyst. The effect of swimmer size and number on these dynamic interactions is interrogated. The level of chemical synchronization between multiple swimmers is determined. This work is a starting point for the design of collective behaviors utilizing autonomous chemically propelled soft swimmers.

Quantization of the Bateman damping system with conformable derivative

In this work, the conformable Bateman Lagrangian for the damped harmonic oscillator system is proposed using the conformable derivative concept. In other words, the integer derivatives are replaced by conformable derivatives of order [Formula: see text] with [Formula: see text]. The corresponding conformable Euler–Lagrange equations of motion and fractional Hamiltonian are then obtained. The system is then canonically quantized and the conformable Schrödinger equation is constructed. The fractional-order dependence of the energy eigenvalues [Formula: see text] and eigenfunctions [Formula: see text] is obtained using suitable transformations and the extended fractional Nikiforov–Uvarov method. The corresponding conformable continuity equation is also derived and the probability density and probability current are thus suitably defined. The probability density evolution as well as its dependence on [Formula: see text] is plotted and analyzed for various situations. It is found that the energy eigenvalues are real and there are sort of gradual ordering in the behavior of the probability densities.

The effects of conical singularity and the Wu–Yang magnetic monopole on the thermodynamic properties of a harmonic oscillator interacting with a potential

Abstract This paper investigates the thermodynamic properties of the harmonic oscillator system in a conical singularities background. Moreover, we incorporate a Wu-Yang magnetic monopole (WYMM) and inverse square potential into the quantum system and analyze the resulting effects. Using analytical methods, we derive the energy eigenvalues and study the thermodynamic properties, such as the partition function, Helmholtz free energy, Gibbs's free energy and specific heat capacity at finite temperature $T \neq 0$. Our findings demonstrate that these physical parameters are influenced by the topological parameter, strength of WYMM and potential parameters. These results provide valuable insights into the interplay between thermodynamic properties of a quantum mechanical problem and the gravitational effects.

Improvement of vibration protection of ship machines and mechanisms based on the use of dynamic stiffness compensators

The purpose of this study is the theoretical justification for improving vibration protection of ship machines and mechanisms based on the use of dynamic stiffeners. The main disadvantage of existing vibration protection devices is the impossibility of resolving the objectively existing contradiction: their efficiency is achieved with a minimum total stiffness of the suspension and, at the same time, to limit the mobility of the mechanism protected from vibration, the stiffness of the elastic elements must be sufficiently high. Design solutions of dynamic vibration dampers are proposed with spring-loaded inertial masses coaxially located relative to the main elastic element of the suspension, which vibrate in antiphase relative to vibrations of the object protected from vibrations. Design schemes of dynamic vibration damper with stiffness compensation developed on the basis of provisions of automatic control theory are presented. Based on the analysis of the developed theoretical assumptions, the main factors affecting the value of the vibration isolation coefficient and allowing to obtain a dynamically stable oscillatory system are determined. The main results of preliminary mathematical modeling of vibration protection system using the model of dynamic damper of low mass vibrations are given. The result of the research is confirmation of the prospects of the proposed technical solutions and the possibility of practical implementation of a full-fledged solution to the problem of protecting ship machines and mechanisms from vibrations.

Delayed optical feedback-regulated artificial soliton molecule in a femtosecond optical parametric oscillator

Soliton molecules (SMs) play a crucial role in nonlinear optical systems, enriching our understanding of nonlinear science through the study of their interaction dynamics. While passively mode-locked fiber lasers offer an efficient platform for generating diverse types of SMs, the complex internal dynamics of the laser often pose challenges in achieving predetermined temporal separations between SMs. Here, we implement a delayed optical feedback technique within a femtosecond optical parametric oscillator, enabling the generation of SMs with precise and controllable temporal separations. A theoretical model, which models the intracavity iterations of the signal with a simplified Ikeda map, is proposed to study the impact of parametric gain, intracavity feedback delay, and cavity length on the internal separations of the SMs. Our experimental results confirm that adjusting the cavity length allows for producing desired temporal separations within SMs. To reveal the evolution dynamics of the SMs, we further develop a rigorous numerical model using the carrier-resolved Forward Maxwell Equation, which is capable of modeling ultra-broadband complex dynamics based on a single equation without relying on the slowly-varying envelope approximation. The numerical model unveils the rich formation dynamics of the SMs at various separations, which confirms the critical role of the gain window provided by the pump. This work opens up new opportunities for the on-demand generation of SMs and provides valuable insights into the complex dynamics in femtosecond optical parametric oscillator systems with optical delayed feedback.

Aperiodic and oscillatory systems underpinning human domain-general cognition

Domain-general cognitive systems are essential for adaptive human behaviour, supporting various cognitive tasks through flexible neural mechanisms. While fMRI studies link frontoparietal network activation to increasing demands across various tasks, the electrophysiological mechanisms underlying this domain-general response to demand remain unclear. Here, we used MEG/EEG, and separated the aperiodic and oscillatory components of the signals to examine their roles in domain-general cognition across three cognitive tasks using multivariate analysis. We found that both aperiodic (broadband power, slope, and intercept) and oscillatory (theta, alpha, and beta power) components coded task demand and content across all subtasks. Aperiodic broadband power in particular strongly coded task demand, in a manner that generalised across all subtasks. Source estimation suggested that increasing cognitive demand decreased aperiodic broadband power across the brain, with the strongest modulations overlapping with the frontoparietal network. In contrast, oscillatory activity showed more localised patterns of modulation, primarily in frontal or occipital regions. These results provide insights into the electrophysiological underpinnings of human domain-general cognition, highlighting the critical role of aperiodic broadband power.

STUDY OF THE DYNAMICS OF A VIBRATION MACHINE CONSIDERING THE INFLUENCE OF THE PROCESSING MEDIUM

This paper presents the results of studying the dynamics of a vibration machine, takinginto account its interaction with the processing medium based on representing the medium as a continuoussystem. The application of the complex number method significantly simplifies the formation of equations ofmotion for the discrete-continuous system, which is a computational model of the vibration system "machinemedium."The study substantiates and develops a method for considering the mutual influence of the machineand the processing medium, based on representing the medium as a continuous system. The dynamicsof the vibration system "machine-medium" is studied, and oscillation parameters are determined withoutconsidering resistance forces. It is found that the overall motion of the vibration system is described by fourcomponents. The first three describe the natural oscillations of the system, of which the first two are determinedonly by initial conditions, and the third reflects the accompanying oscillations caused by the externalforce applied to the system. The last component defines the forced oscillations following the external force'schange law. This result shows that the oscillations of the vibration system are not strictly harmonic, which isconfirmed by the provided graphs. The dynamics of the "machine-medium" vibration system, consideringresistance forces, are studied, and analytical dependencies for determining oscillation amplitudes and natural and resonant frequencies are obtained. The results of the amplitude calculations of the vibration platform forvarious heights of compacted concrete mixtures reveal the influence of the resistance coefficient and theratio of oscillation frequency to the wave propagation speed in the mixture. Analysis of the obtained graphsshows that the resistance coefficient has a different effect on the amplitude of oscillations for different heightsof the compacting mixture. Certain mixture height zones of the vibration system "machine-medium" operatein a near-resonant mode. A significant influence on the amplitude is exerted by the wave propagation speed,which is included in the analytical formulas for determining the numerical values of the coefficients accountingfor reactive and active components of resistance.