Nonhomogeneous Systems Research Articles

Adaptive neural‐based asynchronous control for nonhomogeneous Markov jumping systems with dead zones

Adaptive neural‐based asynchronous control for nonhomogeneous Markov jumping systems with dead zones

Enhanced particle mixing performance of liquid-solid reactor under non-periodic chaotic stirring

This paper introduces the Chebyshev non-periodic chaotic stirring speed based on chaos theory. Additionally, it constructs the DEM-VOF coupled computational model to investigate non-periodic mixing within the reactor system. Numerical calculations are employed to compare and analyze Constant Stirring Speed (CSS) with Chebyshev Non-Periodic Chaotic Stirring Speed and its reverse (CRS, CRS-R). The results indicate that the number of particles deposited at the bottom of end diffusion decreases by 54.3 %. Moreover, it samples particle concentration per unit volume, resulting in a 70.3 % decrease in the Relative Concentration Standard Deviation (RCSD) of particles. Furthermore, it quantifies the mixing effect based on the distribution of distances between particles, leading to a 20.3 % increase in the Unit Block Mixing Index (UBMI). In conclusion, this study improves particle distribution characteristics by utilizing appropriate non-periodic variable speed intervals. Additionally, it provides technical support for production scenarios involving the mixing and dispersion of multiphase non-homogeneous systems.

Adaptive Protocol-Based Control for Nonhomogeneous Stochastic Jump Systems With DoS Attacks and Applications

Adaptive Protocol-Based Control for Nonhomogeneous Stochastic Jump Systems With DoS Attacks and Applications

Z-scheme γ-Fe2O3/g-C3N4 in Photo-Fenton reaction for oxytetracycline degradation: Mechanism study and DFT calculation

With the urbanization and industrialization of the world, the pollution of water due to the misuse of antibiotics is increasing. In this study, a Z-scheme γ-Fe2O3/g-C3N4 composite photocatalyst was prepared, and the removal efficiency of oxytetracycline (OTC) reached 85.7% within 60 min under the Photo-Fenton reaction system higher than that of g-C3N4 and γ-Fe2O3. The composite has great anti-interference capability and sustainability, and the recyclability was demonstrated using hysteresis return lines data. The photoelectrochemical characterization was analyzed to investigate the effect of the building of Z-scheme heterojunction on the photogenerated carrier separation efficiency. The charge behavior of heterojunction interfaces was probed in conjunction with DFT calculations, and differential charge maps were used to visualize charge distributions to analyze possible charge transfer pathways. In addition, the active substances in the system were identified by ESR data and capture experiments. The results showed that ·OH was the dominant active substance for OTC degradation. Meanwhile, LC-MS data combined with Fukui function calculations led to the derivation of a possible degradation pathway dominated by ·OH. This research provides a reference for subsequent studies of non-homogeneous Photo-Fenton systems and offers a viable option for mitigating OTC pollution in water bodies.

Controllability and Observability of Non-homogeneous Granular Descriptor Fractional Dynamical Systems Applied in Electrical Circuit

Controllability and Observability of Non-homogeneous Granular Descriptor Fractional Dynamical Systems Applied in Electrical Circuit

On a class of generalized Choquard system in fractional Orlicz-Sobolev spaces

We study a category of non-homogeneous Choquard systems involving the fractional ϕi(⋅)-Laplacian operator. By establishing suitable hypotheses on the Choquard nonlinearities and the continuous function ϕi, we confirm the existence of nontrivial solutions to the problem at hand. This achievement occurs within the structure of the fractional Orlicz-Sobolev space. Our research makes use of the mountain pass theorem, which circumvents the necessity for the Palais-Smale condition, and strategically leverages the Hardy-Littlewood-Sobolev inequality to enhance our analysis.

Neural Network-Based Anti-Disturbance Control of Nonhomogeneous Markov Switching Systems

Neural Network-Based Anti-Disturbance Control of Nonhomogeneous Markov Switching Systems

Spectral optical performance of phase-change-material-filled glass-block system: Experimental evaluation and comparative exploration

Research on sustainable building design is pushing boundaries to introduce innovative solutions that enhance energy efficiency and improve user comfort. The integration of phase-change materials (PCMs) into transparent façade elements has gained substantial attention; however, its widespread application in current construction practices remains limited. This study examined the solar/light transmittance of PCM-based materials embedded in transparent façade elements, focusing on providing and comparing the optical properties of modular glass blocks integrated with PCM measured experimentally in a laboratory setting. Optical properties of multi-layer and non-homogeneous systems represent a more complex problem in terms of proper characterisation. To overcome this limitation, more comprehensive approaches can be considered, including integrating spheres to perform measurements on the complex nonhomogeneous glass system. This study employed spectrophotometric measurements within the visible and near-infrared (NIR) spectra by two different measurements methods: a direct method and one using an integrating sphere. Additionally, the investigation was based on a comparison between clear and various PCM-filled glass blocks. The results demonstrated that the direct method facilitated reliable spectral transmittance measurements with deviations not exceeding 3 %. In addition, the results revealed that paraffinic PCM glass blocks in liquid phases could achieve up to 90 % of light transmission and act as a highly transparent system in the visible region compared with conventional air-based glass blocks (up to 77 %). However, in the NIR region, the spectral transmission of PCM glass blocks was reduced by half (around 46 %). Depending on the PCM type in solid phases, the visible transmission is significantly reduced, which is from 5 % to a maximum of 19 %. This study contributes to the expanding knowledge base on adaptive building systems, particularly those related to PCM integration in transparent façade components.

Influence of Co-Ni interactions on catalytic activity of xCo/NiO nanosheet catalysts in situ grown on monolithic cordierite for soot combustion

Co3O4-loaded NiO monolithic catalysts were successfully prepared on cordierite substrates using a simple hydrothermal and impregnation method. The mass transfer of gaseous reactants and products during soot combustion is facilitated by the constructed macroporous voids, thereby enhancing the soot-catalyst contact efficiency. The results demonstrate that the interaction of Ni and Co (Co2+ + Ni3+ ↔ Ni2+ + Co3+) leads to an increase in the amount of Co3+ cations, resulting in a higher quantity of oxygen vacancies. Besides the surface adsorbed oxygen (Oads), it demonstrates that the hydroxyl group (-OH) also acts as active oxygen species in soot oxidation. And, the impact of Co loading on the catalysts displays a volcano-type on the performance of soot oxidation. 0.5Co/NiO with the strongest CO-Ni interaction possesses the highest intrinsic activity. As a result, 0.5Co/NiO shows the highest activity with T50 at 382 °C in 600 ppm NO/10 % O2/N2 flow, as well as high stability and water resistance. Moreover, the prepared catalysts can efficiently catalyze NO to NO2, which possesses higher reactivity for soot oxidation than O2 and NO. Consequently, the as-designed Co/NiO monolithic catalysts hold great potential for applications in soot combustion and other non-homogeneous catalytic systems.

Assessing structural integrity of non-homogeneous systems by means of Acoustic Emissions and Non-Extensive Statistical Mechanics

Taking advantage of the interevent time intervals, namely the time intervals between two successive acoustic events recorded during mechanical loading of structural elements, it is attempted to detect indices warning about upcoming failure. The innovative aspect of the study is that the analysis is implemented in the frame of Non-Extensive Statistical Mechanics, a discipline founded on a class of entropies violating the additivity principle, which is the cornerstone of the Boltzmann-Gibbs Statistical Mechanics. The specimens used for the experiments were marble blocks simulating either fragmented and restored epistyles or mutually interconnected intact epistyles of the Parthenon Temple on the Acropolis of Athens. The specimens consisted of three mate­rials (marble, metallic connectors and cementitious pastes) exhibiting, thus, a strongly non-homogeneous nature. The entropic index, i.e., the parameter quantifying the degree of non-additivity, was used for the analysis of the ex­pe­rimental data. The results were considered in juxtaposition to the re­spective ones from experimental protocols with specimens of macroscopically homo­geneous nature. It was concluded that the temporal evolution of the entropic index provides very good insight into the level of damage ac­cumu­lated in the loaded structure, independently of whether the structure is homogeneous or not, providing an interesting pre-failure indicator.

Modeling solvent effects and convergence of 31P-NMR shielding calculations with COBRAMM.

Solvent effects on 31P-NMR parameters for triphenylphosphine oxide and triphenylphosphine in chloroform have been extensively investigated by testing different solvation models. The solvent is described implicitly, mixed implicitly/explicitly, and using full explicit models. Polarizable continuum model (PCM), molecular dynamic (MD) simulations, and hybrid quantum mechanics/molecular mechanics (QM/MM) calculations are used to disclose the effects of solute/solvent interactions and, more generally, the role of the embedding in NMR simulations. The results show the beneficial effect of carrying out QM/MM optimizations on top of geometries directly extracted from classical MD simulations, used to ensure representative conformational sampling. The nuclear shielding convergence has been tested against a different number of snapshots and with the inclusion of solvent shells into the QM region. An automated MD//QM/MM//GIAO protocol, implemented in the COBRAMM package, is here proposed and tested on trimethyl phosphite showing that our approach boosts the convergence of nuclear shielding satisfactorily. The present work aims to be a stepping-stone to assess proper QM/MM computational strategies in simulating chemical shifts in non-homogeneous systems like supramolecular and biological systems.

Strong Ergodicity in Nonhomogeneous Markov Systems with Chronological Order

In the present, we study the problem of strong ergodicity in nonhomogeneous Markov systems. In the first basic theorem, we relax the fundamental assumption present in all studies of asymptotic behavior. That is, the assumption that the inherent inhomogeneous Markov chain converges to a homogeneous Markov chain with a regular transition probability matrix. In addition, we study the practically important problem of the rate of convergence to strong ergodicity for a nonhomogeneous Markov system (NHMS). In a second basic theorem, we provide conditions under which the rate of convergence to strong ergodicity is geometric. With these conditions, we in fact relax the basic assumption present in all previous studies, that is, that the inherent inhomogeneous Markov chain converges to a homogeneous Markov chain with a regular transition probability matrix geometrically fast. Finally, we provide an illustrative application from the area of manpower planning.

Optimizing the Activation Energy of Reactive Intermediates on Single-Atom Electrocatalysts: Challenges and Opportunities.

Single-atom catalysts (SACs) have made great progress in recent years as potential catalysts for energy conversion and storage due to their unique properties, including maximum metal atoms utilization, high-quality activity, unique defined active sites, and sustained stability. Such advantages of single-atom catalysts significantly broaden their applications in various energy-conversion reactions. Given the extensive utilization of single-atom catalysts, methods and specific examples for improving the performance of single-atom catalysts in different reaction systems based on the Sabatier principle are highlighted and reactant binding energy volcano relationship curves are derived in non-homogeneous catalytic systems. The challenges and opportunities for single-atom catalysts in different reaction systems to improve their performance are also focused upon, including metal selection, coordination environments, and interaction with carriers. Finally, it is expected that this work may provide guidance for the design of high-performance single-atom catalysts in different reaction systems and thereby accelerate the rapid development of the targeted reaction.

The dichotomy property in stabilizability of 2 × 2 linear hyperbolic systems

This paper is devoted to discuss the stabilizability of a class of 2 × 2 non-homogeneous hyperbolic systems. Motivated by the example in the Section 5.6 of Bastin and Coron’s book in 2016, we analyze the influence of the interval length L on stabilizability of the system. By spectral analysis, we prove that either the system is stabilizable for all L > 0 or it possesses the dichotomy property: there exists a critical length Lc > 0 such that the system is stabilizable for L ∈ (0, Lc) but unstabilizable for L ∈ [Lc,+∞). In addition, for L ∈ [Lc, +∞), we obtain that the system can reach equilibrium state in finite time by backstepping control combined with observer. Finally, we also provide some numerical simulations to confirm our developed analytical criteria.

Transient Response of Homogenous and Nonhomogenous Bernoulli Production Lines

The transient response of production systems is of significant importance especially if present advancements in Digital Twinning technology are taken into account. While the steady-state response enables long-term strategic decision making, the transient response enables more detailed simulation concerning aspects like production losses and preventive maintenance. This is especially relevant if nonhomogenous aspects of production systems are taken into account. An analytical and approximative solution to the problem of the transient response of homogenous and nonhomogenous Bernoulli production systems is developed in this paper based on the eigendecomposition of transition matrices, the eigenvalue problem, and the finite-state method. In particular, sub-resonant and resonant nonhomogeneous production lines are introduced for the first time. Also, the most significant key performance indicators are developed as functions of the time elapsed from the first cycle. Finally, the relationship between the number of eigenvalues and the accuracy of the results is inspected by employing a sensitivity analysis. The presented theoretical framework was employed in the case of a wood processing facility to present the potential application of the theory in the case of long- and short-term management of production systems.

Comparative performance of Algeria's education districts: The Influence of colonial legacy through cultural capital

This article aims to analyze the comparative performance of Algeria's education districts using a two-stage DEA methodology. Modeling their functioning as non-homogeneous parallel sub-unit production systems, districts are considered Decision-Making Units with three educational subunits. This type of modeling provides an overall regional efficiency analysis of the entire education sector. Furthermore, the current research links early colonial policy of educational discrimination across regions to present-day regional educational performance. The main DEA-like model evaluates the average overall efficiency at 74.5% and identifies no efficient district while the standard DEA overestimates this average by 20.8% and identifies five efficient districts with no efficient subunits. Moreover, IV truncated regression estimates the impact of one standard deviation increase in cultural capital to be a 0.81 standard deviation increase in the efficiency score with a 95% bootstrap percentile confidence interval covering estimations of all alternative methods. The findings confirm that history matters and seem to fit the narrative of the link between colonial legacy and present-day educational performance through the cultural capital transmission channel.

Cross-efficiency evaluation method for non-homogeneous parallel network systems with imprecise data

Cross-efficiency evaluation method for non-homogeneous parallel network systems with imprecise data

Feedback stabilization of non-homogeneous distributed bilinear systems with varying time delay

This paper deals with the feedback stabilization for a class of non-homogeneous distributed bilinear systems, with periodically varying time delay, evolving in Hilbert state space. Sufficient conditions for polynomial and exponential stabilization are given. Explicit energy decay rates are provided in both cases. Illustrative examples are displayed.

Arched beams of Bresse type: New thermal couplings and pattern of stability

This is the second paper of a trilogy intended by the authors in what concerns a unified approach to the stability of thermoelastic arched beams of Bresse type under Fourier’s law. Differently of the first one, where the thermal couplings are regarded on the axial and bending displacements, here the thermal couplings are taken over the shear and bending forces. Such thermal effects still result in a new prototype of partially damped Bresse system whose stability results demand a proper approach. Combining a novel path of local estimates by means of the resolvent equation along with a control-observability analysis developed for elastic non-homogeneous systems of Bresse type proposed in trilogy’s first paper, we are able to provide a unified methodology of the asymptotic stability results, by proving the pattern of them with respect to boundary conditions and the action of temperature couplings, which is in compliance with our previous and present goal.

Online identification of non-homogeneous fractional order Hammerstein continuous systems based on the principle of multi-innovation

Online identification of non-homogeneous fractional order Hammerstein continuous systems based on the principle of multi-innovation