Dissipative Method Research Articles

Reciprocal or nonreciprocal bimolecular interface and quantum entanglement

We study a hybrid system of a plasmonic cavity coupled to a pair of different molecular vibration modes with the strong optomechanical-like interactions. Here, this plasmonic cavity is considered as a quantum data bus and then assist several applications. For instance, it can first establish a bimolecular interface to ensure the reciprocal or non-reciprocal information transmission, and then engineer both molecules into the steady-state quantum entanglement of the continuous variable through the dissipative method. In contrast to the traditional optomechanical system, this hybrid system can provide the stronger optomechanical-like interactions and more convenient controls to the molecular quantum units. This investigation is believed to be able to further expand the practical application range of quantum technology.

Effects of flowing red blood cells on the motion of a circulating tumour cell in the asymmetric bifurcated microvessel

ABSTRACT Asymmetric bifurcate are common in the vascular system, and circulating tumour cells (CTCs) tend to metastasize at these locations. In this study, the dissipative particle dynamics method is used to simulate the motion of a CTC in an asymmetric microvessel combined with a spring-based network model. Effects of flow rate, the presence of RBCs and haematocrit on the motion of the CTC are investigated. The results indicate that under higher flow rate, the CTC could not adhere to the microvessel and invariably migrated towards the branch exhibiting a higher flow rate. In the presence of RBCs, the initially attached CTC would disassociate from the parent vessel wall under the collisions with them, and it finally enters into the large branch. While at lower flow rates, the RBCs pass over the CTC that is rolling along the top wall of the parent vessel and overtake it, facilitating the CTC adhesion, it ultimately moves into the small branch. At a mediate flow rate, though the attached CTC detaches and enters into the large branch, it would touch the inner wall of the branch. With the haematocrit increasing up to 5.1%, the CTC retains rolling along the vessel wall and is ultimately captured in the small branch.

Analysis of Electric Breakup Characteristics of Emulsion Droplets Based on Dissipative Particle Dynamics Method

Crude oil desalination and dehydration are necessary for storage, transportation, and processing procedures. However, the behaviour of fine emulsion droplets under an electric field has always been questioned. This paper modified the dissipative particle dynamics method (DPD) to study the deformation process of fine emulsion droplets under a high-strength electric field. Compared with the literature data, the reliability of the DPD method is confirmed. The influence of the crude oil properties and the electric field characteristics on the behaviour of the emulsion droplet was analysed, and the effect factors included electric field intensity, electric field frequency, emulsion droplet size, centre distance ratio, conservative force intensity, dissipative strength, and crude oil density. The relationship between critical electric field intensity and emulsion droplet deformation was formulated based on the simulational dates.

All-natural and triple-inspired Janus electrospun fibers with integrated functions for high-performance liquid food packaging

The liquid barrier is a central component of functional liquid packaging materials and is crucial for encapsulating liquid food. To develop high-performance liquid packaging materials for the long-term storage of liquid food, a strong and stable liquid barrier and the simultaneous integration of diverse functionalities must be realized. In this study, inspired by mussel adhesion proteins, nanoparticles are synthesized through oxidative self-polymerization. Furthermore, electrostatic spinning is used for creating multifunctional electrospun fibers for liquid food packaging, which is inspired by the superhydrophobicity of lotus leaf surface and structures of red blood cells. A unique Janus structure with a thin hydrophilic layer and a thick hydrophobic layer prevents liquid food penetration for 12 (EHN/KN electrospun fibers) and 17 days (KN/EHN electrospun fibers). The liquid infiltration mechanism of Janus electrospun fibers is elucidated using the multibody dissipative particle dynamics method, emphasizing their efficacy in avoiding liquid penetration. Moreover, multifunctional KN/EHN electrospun fibers exhibit remarkable characteristics such as water resistance (water contact angle > 150°), UV-blocking (∼100 %), degradability (70 days in soil), biosafety (∼100 %), antioxidation (> 90 %), antimicrobial (∼100 %), grapes and meat freshness retention properties. Thus, this study provides insights into sustainable, high-performance liquid food packaging for enhanced preservation.

Cholesteric liquid crystal phase variations within nanotubes: an in-depth analysis of the influences of twist radius and molecular pitch

ABSTRACT This study investigates the self-assembly and phase transitions of cholesteric liquid crystals (CLCs) when confined in nanotubes, specifically focusing on the variations in their molecular structures. A dissipative particle dynamics method was used to investigate how the changes in helix radius ( r LC ) and pitch ( P ) affect the behaviour of the LCs. For pitches of 24, 12, and 6, the orientation order parameter ( P 2 ) showed distinct trends during cooling. Smaller helix radii resulted in isotropic to nematic to smectic phase transitions, whereas larger radii resulted in a novel smectic phase with spiral structures (Sm s ). Circumferential local-order parameters ( P 2 r and P 2 z ) were introduced to better characterise the phases, and a disordered spiral-structure phase (Sm s 2 ) with local perturbations was observed. The transitions between isotropic, nematic, and smectic phases, highlighting the influence of the pitch and helix radius, were observed from the phase diagrams. Smaller pitches and radii prevented the formation of stable structures; however, specific combinations induced characteristic spiral structures in the smectic phase. These results provide new insights into the self-assembly of confined CLCs, which have potential applications in the design of photonic devices and LC-based sensors. This study advances our understanding of phase control in quasi-one-dimensional systems and highlights the importance of molecular variations in liquid crystal behaviour.

Expression of Concern: Representing Fluid Particle Model to incorporate two non-central components for dissipation forces associated with random forces: A new integral algorithm in modified Dissipative Particle Dynamics method

Expression of Concern: Representing Fluid Particle Model to incorporate two non-central components for dissipation forces associated with random forces: A new integral algorithm in modified Dissipative Particle Dynamics method

Investigation of LAS-based fatigue evaluation methods for high-viscosity modified asphalt binders with high-content polymers

The objective of this paper is to investigate the microstructure of high-viscosity modified asphalt binder (HVA) containing high-content polymers and its effect on fatigue performance, as well as the applicability of different analytical methods and failure criteria of linear amplitude sweep (LAS) test to HVA. In this paper, two types of HVAs with different polymer contents, a commercial HVA, a conventional polymer-modified asphalt binder, and a base asphalt binder were first prepared or selected. Fluorescence microscopy tests, time sweep tests, and LAS fatigue tests were then performed on these binders. Finally, the fatigue properties of the different binders were analyzed in depth using different analytical methods and failure criteria. The results show that the polymers in HVA crosslink with each other to form a strong cross-linking structure, and the phase inversion of the polymers renders them into a continuous phase, which significantly improves the fatigue damage resistance of the HVA; moreover, the evolutions of stress with shear strain for the fatigue process of HVAs is related to the polymer network. Besides, the two-dimensional damage characteristic curve (DCC) cannot accurately reflect the evolution of the fatigue performance of HVA, and this paper suggests the use of a three-dimensional DCC curve with strain information. Furthermore, the 35% reduction in C0 in the dissipative energy method is not a suitable failure criterion, a more accurate fatigue performance ranking can be obtained by using the yield stress as the failure criterion. Although the fatigue resistance of HVA after yield stress is theoretically considered using the pseudo-strain energy approach, HVA does not show a peak of stored pseudo-strain energy even when the strain is increased to 60% in the LAS test. Therefore, the maximum strain value (30%) in the standard LAS test is not sufficient in characterizing high-polymer HVAs because there is not enough fatigue accumulation of HVAs in this range, consequently, the maximum shear strain parameter in the LAS experiment needs to be reconsidered.

Adsorption mechanism of asphaltenes and surfactants at oil-water interface: based on dissipative particle dynamics method

The study of emulsion stabilization mechanisms is of great importance in the field of crude oil extraction, transportation and processing. In order to further investigate the roles of asphaltenes and surfactants in the emulsion stabilization process, the adsorption mechanisms of asphaltenes and surfactants at the oil-water interface were investigated using dissipative particle dynamics. The results show that: the asphaltene interfacial film gradually becomes thicker before the saturation adsorption of asphaltene molecules at the oil-water interface, and the interfacial tension decreases with the increase of the number of molecules until it reaches the equilibrium state; different surfactant molecules have different influences on the interface, and the calculations of the radial distribution function and the interfacial tension show that H2T4 molecules have a stronger effect than H4T4 at the oil-water interface and have stronger surface activity. H2T4 reaches saturation adsorption capacity faster than H4T4 and has higher interfacial efficiency. The asphaltene-surfactant composite system can stabilize the oil-water interface more effectively. Competitive and synergistic effects of asphaltene and surfactant in the process of interfacial adsorption. When the concentration of surfactant in the composite system is low, there is a synergistic effect between the two in the interfacial adsorption process; when the concentration of surfactant is high, there is a competitive effect between the two in the synergistic adsorption process. The surfactant H4T4 has both interfacial adsorption and self-aggregation in the competitive adsorption process. This paper provides ideas for exploring the kinematic laws of molecular behavior in the stabilization mechanism of crude oil emulsions.

Synergy between surfactants' stiffness and concentration on their self-assembly into reverse micelles as water droplet carriers in nonpolar solvents.

A study of the self-assembly process into reverse micelles (RMs) of linear surfactants and monomeric aqueous solutes dissolved in nonpolar solvents, varying the concentration (cs) and the persistence length (Lp) of the surfactants is presented here. The influence of cs and Lp on the structural and dynamic properties of the aggregates is investigated through mesoscopic simulations carried out with the dissipative particle dynamics method. All simulations are performed at a fixed water/surfactant molecular ratio of 2:1, varying the surfactant concentration from c = 6 wt% up to c = 12 wt%, for increasing surfactants' rigidity from Lp = 0.73 nm up to Lp = 44.99 nm. It is found that there exists a collaborative interplay between cs and Lp that enhances the number of RMs assembled and their diffusion as carriers of water droplets. These results should be useful as guidelines to understand and improve processes where the RMs are implemented to carry aqueous solutes in nonpolar solvents.

Motion of microswimmers in cylindrical microchannels.

Biological and artificial microswimmers often have to propel through a variety of environments, ranging from heterogeneous suspending media to strong geometrical confinement. Under confinement, local flow fields generated by microswimmers, and steric and hydrodynamic interactions with their environment determine the locomotion. We propose a squirmer-like model to describe the motion of microswimmers in cylindrical microchannels, where propulsion is generated by a fixed surface slip velocity. The model is studied using an approximate analytical solution for cylindrical swimmer shapes, and by numerical hydrodynamics simulations for spherical and spheroidal shapes. For the numerical simulations, we employ the dissipative particle dynamics method for modelling fluid flow. Both the analytical model and simulations show that the propulsion force increases with increasing confinement. However, the swimming velocity under confinement remains lower than the swimmer speed without confinement for all investigated conditions. In simulations, different swimming modes (i.e. pusher, neutral, puller) are investigated, and found to play a significant role in the generation of propulsion force when a swimmer approaches a dead end of a capillary tube. Propulsion generation in confined systems is local, such that the generated flow field generally vanishes beyond the characteristic size of the swimmer. These results contribute to a better understanding of microswimmer force generation and propulsion under strong confinement, including the motion in porous media and in narrow channels.

Dynamic dissipative control for fuzzy distributed parameter cyber physical system under input quantization and DoS attack.

This article explores the dissipative control for a class of nonlinear DP-CPS (distributed parameter cyber physical system) within a finite-time interval. By utilizing a Takagi-Sugeno (T-S) fuzzy model to represent the system's nonlinear aspects, the studied system is formulated as a class of fuzzy parabolic partial differential equation (PDE). In order to optimize network resources, both the system state and input signal are subjected to quantization using dynamic quantizers. Subsequently, a dynamic state control strategy is proposed, taking into account potential DoS attack. The finite-time boundedness of the fuzzy parabolic PDE is analyzed, with respect to the influence of quantization, through the construction of an appropriate Lyapunov functional. The article then presents the conditions for finite-time dissipative control design, alongside the adjustment parameters for the dynamic quantizers within the fuzzy closed-loop system. Furthermore, the decoupling of interlinked nonlinear terms in the control design conditions is achieved by using an arbitrary matrix. Finally, an example is provided and the simulation results indicate the effectiveness of the dissipative control method proposed.

Collective behavior of squirmers in thin films.

Bacteria in biofilms form complex structures and can collectively migrate within mobile aggregates, which is referred to as swarming. This behavior is influenced by a combination of various factors, including morphological characteristics and propulsive forces of swimmers, their volume fraction within a confined environment, and hydrodynamic and steric interactions between them. In our study, we employ the squirmer model for microswimmers and the dissipative particle dynamics method for fluid modeling to investigate the collective motion of swimmers in thin films. The film thickness permits a free orientation of non-spherical squirmers, but constraints them to form a two-layered structure at maximum. Structural and dynamic properties of squirmer suspensions confined within the slit are analyzed for different volume fractions of swimmers, motility types (e.g., pusher, neutral squirmer, puller), and the presence of a rotlet dipolar flow field, which mimics the counter-rotating flow generated by flagellated bacteria. Different states are characterized, including a gas-like phase, swarming, and motility-induced phase separation, as a function of increasing volume fraction. Our study highlights the importance of an anisotropic swimmer shape, hydrodynamic interactions between squirmers, and their interaction with the walls for the emergence of different collective behaviors. Interestingly, the formation of collective structures may not be symmetric with respect to the two walls. Furthermore, the presence of a rotlet dipole significantly mitigates differences in the collective behavior between various swimmer types. These results contribute to a better understanding of the formation of bacterial biofilms and the emergence of collective states in confined active matter.

Adaptive sliding mode observers‐based dissipative Hamilton finite time optimization control for the speed and tension system of reversible cold strip rolling mill

SummaryFor the complex time‐varying uncertain nonlinear speed and tension system of reversible cold strip rolling mill, an adaptive sliding mode observers (ASMOs)‐based dissipative Hamilton finite time optimization control method is given in this article. First, the ASMOs are developed to observe rolling mill system's unmatched uncertainties, and their observation errors can converge to the origin in finite time. Second, combined with rolling mill system's physical structure characteristics, its dissipative Hamilton model is established by pre‐feedback processing, and then the dissipative Hamilton finite time controllers are designed based on interconnection and damping configuration and energy shaping method, and the system states can converge in finite time. Third, the adaptive mutation particle swarm optimization algorithm is adopted to optimize the controller parameters, which can further improve rolling mill system's control performance. Finally, the simulation results verify the validity of the given method based on actual field data.

Understanding the pore structure evolution of polyethylene separator with dissipative particle dynamics simulation

AbstractThe commercialized lithium‐ion battery separators are mass‐produced by mixing ultra‐high molecular weight polyethylene (UHMWPE) and paraffin oil (PO). The dissipative particle dynamics method is utilized to investigate the extrinsic factors (shear rate and cooling rate) and the intrinsic factors (the molecular chain length) on the microstructure of the UHMWPE‐PO mixture. For the mixture with UHMWPE possessing the same chain length, the high shear rate promoted a lower porosity (~28%) and smaller pores. In contrast, the slow shearing led to a high porosity (~40%) and larger pores. For the mixture with UHMWPE possessing short and long chains, the shear rate hardly affects the porosity and the pore size: the porosity was kept at ~30%, and the pore size was reduced by ~35% compared to the model with the same‐chain‐length UHMWPE. The cooling rate after shearing is the dominant factor in determining the porosity and pore size: the fast cooling raised the porosity by ~33% but hardly increased the pore size, while the slow cooling raised the porosity by ~74%, and the pore size by ~105%. The current study provided a deep understanding of the pore structure evolution in separator processing.Highlights The effects of processing parameters on the pore structures are numerically illustrated. MD simulation and rheometer measurement assist DPD interaction parameters calibration for UHMWPE and PO. The low shear rate leads to a higher porosity and pore size. At the high shear rate, short UHMWPE chains reduce porosity but do not increase pore size. The fast‐cooling process slightly increases the porosity while keeping the pore size.

Formula omitted]-[formula omitted]-dissipative control of T-S fuzzy systems via aperiodic sampling control with communication delay

This article concerns the strict (Q,S,R)-γ dissipativity of Takagi–Sugeno fuzzy systems (TSFSs) via aperiodic sampled-data control with communication delay. The motivations of this paper are that the transmission channels have communication delay and the original dissipative analysis method may be conservative. In order to consider the impact of communication delays, first of all, a sampled-data controller (SDC) with a constant communication delay is conceived to analyze the dissipativity of TSFSs. Next, the overall closed-loop system model is established stemming from the designed controller. In order to attain less conservative results, a new looped-functional which can take advantage of the available information of the sampling instants is formed. Then, strict (Q,S,R)-γ dissipativity can be guaranteed by a criterion obtained by using the looped-functional and the modified free-matrix-based inequality (FMBI) technique. By working out the obtained linear matrix inequalities (LMIs), the controller gain matrix that meets the requirement can be determined. Finally, the truck trailer and the mass–spring systems are showcased as simulation examples to provide evidence of the effectivity and superiority of the devised approach. In the presence of 0.1 s communication delay in the truck trailer system controller, the maximum γ can reach 0.9751 when sampling interval h takes 0.15 s, which makes the system can achieve strict (Q,S,R)-γ dissipativity.

Effect of Film Thickness on the Self-Assembly of CBABC Symmetric Pentablock Terpolymer Melts under 1D Confinement: A Dissipative Particle Dynamic Study.

The study investigates the impact of film thickness on the phase behavior of pentablock terpolymers, denoted as C3B3A6B3C3, when subjected to wall confinement by utilizing the dissipative particle dynamics method. Phase diagrams were constructed to elucidate how factors such as block-block interaction strength, film thickness, and wall properties affect the self-assembly structures. In cases where the wall exhibits no preference for any of the blocks, lamellae phases with orientations perpendicular to the wall are observed. The order-disorder transition (ODT) temperature is found to be influenced by the interaction between the polymer and the wall in thin confinement scenarios. When the wall displays a preference for specific blocks, the orientation of lamellae structures undergoes variations. Lamellae tend to align parallel to the wall when the wall favors A or C blocks, and they orient perpendicularly when B blocks are favored. Furthermore, the mechanical properties of the lamellae structures are related to the conformations of the polymer chains. Structures where chains predominantly adopt a loop conformation exhibit enhanced elastic properties. The ratio of looping to bridging conformations can be adjusted by altering the film thickness and wall selectivity.

Representing the Fluid Particle Model to incorporate two non-central components for dissipation forces associated with random forces: A new integral algorithm in the modified Dissipative Particle Dynamics method

The standard formulation of dissipative particle dynamics (DPD) only considers centripetal forces acting on a single DPD particle, neglecting the eccentric cut-off forces between dissipation particles. Consequently, this model does not account for angular momentum and torque for individual DPD particles, whereas suspended particles in a stream exhibit both translational and rotational motion. To overcome this limitation, the fluid particle model (FPM) is proposed in this study, which incorporates two non-central cut-off components for dissipation forces that are associated with random forces via the fluctuation-dissipation theory. To accurately account for single particle hydrodynamics, a novel integration algorithm is introduced and assessed for its precision. Through simulations in low Reynolds number flows, this research determines the coefficients of the modified DPD formulation and validates its accuracy for simulating colloidal and polymeric solutions. Furthermore, this modified model can be employed for simulating currents passing through single DPD particles. The simulation results are compared with the analytical results, revealing the superior accuracy of the modified formulation. The findings also suggest an optimal choice of constants, time steps, and weight functions.

Unraveling the Interactions between Nanoparticles and Benzo[a]pyrene in Environmental Waters and Human Blood by Dissipative Particle Dynamics Simulations

Abstract The microscopic interactions between nanoparticles with different physicochemical properties and benzo[a]pyrene (BaP) in environmental waters and human blood are still unknown. By using dissipative particle dynamics method, we found that the interaction parameter between beads in nanoparticles and BaP (aNP) can dictate the dispersion state of them in water and the distance between protein corona and nanoparticles in simulated human blood. Moreover, blood proteins reduce the number of BaP adsorbed on nanoparticles when aNP ≤ 25 and increase the number of BaP when aNP > 25. These findings provide detailed interaction information of combined pollutants at microscopic level.

Poisson stable solutions and solution maps for stochastic functional differential equations

We observe Poisson stable solutions for nonlinear stochastic functional differential equations (SFDEs) with finite delay. Firstly, we prove the existence and uniqueness of bounded (in square-mean sense) solutions and solution maps for SFDEs with finite delay by remoting start (or dissipative method) and classical pull-back attraction method. Then, based on the relationship between the solution and coefficients, we obtain such Poisson stable solutions by using Shcherbakov’s comparability method in character of recurrence. Because the solutions of the delay equations are not-Markov, we employ the solution maps in the appropriate phase space as a viable alternative for studying further asymptotic properties, and we also discuss Poisson stable solution maps and their asymptotic stability. For illustration of our results, we give the application arising from stochastic Lotka–Volterra cooperative systems with distributed delay.

The symplectic cohomology of magnetic cotangent bundles

We construct a family version of symplectic Floer cohomology for magnetic cotangent bundles, without any restrictions on the magnetic form, using the dissipative method for compactness introduced by Groman (2023). As an application, we deduce that if N is a closed orientable manifold and is a magnetic form that is not weakly exact, then the \pi_1 1-sensitive Hofer–Zehnder capacity of any compact set in the magnetic cotangent bundle determined by \sigma is finite.