Synchronization of neural networks with and without disturbance input via control Lyapunov function.

Mussel-inspired nanocellulose scaffold for antibacterial and anti-inflammatory coating for clear aligners.

To address the challenges of low surface charge density, poor stability in humid conditions, and unstable performance in polymer electret triboelectric nanogenerators (TENGs), this study presents a synergistic enhancement strategy combining electrospinning and corona charging. The PAN-PVDF composite nanofiber membrane prepared via electrospinning achieves an initial surface potential of -3.2 kV. Following secondary corona electret treatment, the surface potential significantly increased to - 12.3 kV. In contact-separation mode, this electret demonstrated outstanding output performance: within an operating frequency range of 2–4 Hz and a separation distance of 4–5 mm, its maximum power density reached 12 μW cm -2 (under matched load). Furthermore, the device charged a 47 μF commercial capacitor to 12 V within 15 minutes at 2.5 Hz, demonstrating practical energy storage and driving capabilities. Compared to conventional materials such as PTFE and pure PVDF, the PAN-PVDF composite fiber membrane exhibits a high initial potential, a slow charge decay rate, and good mechanical stability after electret processing. This research provides a highly viable material and process pathway for high-performance self-powered devices in wearable technology and IoT applications.

FusionNet is a parallel, hybrid deep-learning framework engineered for next-generation speech recognition and on-device speech-to-text processing. The system is implemented as an Android application (Java/XML) and integrated with Firebase Realtime Database to support secure, user-centric data management. Audio input undergoes a multi-stage preprocessing pipeline where MFCC, spectral, and temporal features are extracted and clustered using K-Means to group acoustically similar speech segments. These clustered representations are simultaneously processed through a dual-branch architecture: a Convolutional Neural Network (CNN) that learns spectral signatures and a Bidirectional Long Short-Term Memory (BiLSTM) network that models temporal dependencies. The fused embeddings are then classified using a Random Forest classifier, improving prediction stability in noisy or accent-variable conditions. To enhance semantic clarity, an NLP engine supported by a generative AI model refines the raw transcriptions, corrects contextual errors, and extracts user intent. Real-time inference is achieved via TensorFlow Lite (TFLite), enabling low-latency, energy-efficient execution directly on mobile hardware without cloud dependency. FusionNet demonstrates robustness against ambient noise, speaker variability, and multilingual inputs, making it a practical and scalable solution for voice-driven applications. This hybrid architecture effectively combines clustering, parallel deep learning, classical ML classification, and generative AI reasoning to deliver an intelligent, high-accuracy speech recognition system tailored for real-world deployment.

This paper investigates the inverse problem of reconstructing time-dependent source terms in time-fractional diffusion equations with Caputo derivatives, which are widely used to model anomalous subdiffusive processes. The objective is to recover the temporal behaviour of unknown source functions from final-time boundary measurements. The methodology integrates both analytical and computational steps. First, a new Carleman estimate is established, ensuring uniqueness and conditional stability of the inverse problem. Next, this theoretical guarantee is used to design a numerical inversion framework. The forward problem is discretized using finite-difference and spectral schemes, and the source term is reconstructed through a regularized Levenberg–Marquardt optimization algorithm. Numerical experiments are then performed on synthetic and perturbed datasets to evaluate the accuracy and stability of the method. Results demonstrate strong resilience to noise and precise recovery of source terms under various test conditions. To the best of our knowledge, this is the first work to apply Carleman estimates to inverse problems in time-fractional diffusion equations, providing both theoretical validation and numerical implementation. The approach is applicable in diverse fields, including geophysics, biomedical imaging, and environmental monitoring.

Museums open to the public must reconcile heritage preservation requirements with energy-conscious microclimate management and visitors’ environmental experience. In historic buildings, indoor conditions are typically controlled primarily for preventive conservation, while opportunities for detailed assessment of human comfort are often limited by existing monitoring systems and operational constraints. This study investigates visitors’ perceptions of thermal conditions and indoor air quality (IAQ) in two branches of the National Museum in Krakow (NMK) characterized by different microclimate-control strategies: the mechanically ventilated and air-conditioned Cloth Hall and the predominantly passively controlled Bishop Erazm Ciołek Palace. A pilot survey was conducted in spring 2023 to capture subjective assessments of thermal sensation and perceived IAQ. These perceptions were contextualized using long-term air temperature and relative humidity data (2013–2023) routinely monitored for conservation purposes. Environmental data were analyzed to assess the stability of indoor conditions and to provide background for interpreting survey responses, rather than to perform a normative evaluation of thermal comfort. The results indicate that visitors frequently perceived the indoor environment as slightly warm and reported lower air quality in the Palace, where air was often described as stale or stuffy. These perceptions occurred despite relatively small differences in monitored air temperature and relative humidity between the two buildings. The findings suggest that ventilation strategy, air exchange effectiveness, odor accumulation, room configuration, and lighting conditions may influence perceived environmental quality more strongly than temperature or humidity alone. Although limited in scope, this pilot study highlights the value of incorporating visitor perception into discussions of energy-conscious microclimate management in museums and indicates directions for further multidisciplinary research.

Xyloglucan, a key component of plant cell wall polysaccharides, plays a crucial role in cell wall structural remodeling and biomass recalcitrance. This study reports the discovery and biochemical characterization of a novel glycoside hydrolase family 12 (GH12) xyloglucanase, TpXEG12a, from the biomass-degrading fungus Talaromyces pinophilus. Recombinant TpXEG12a exhibited exceptional catalytic efficiency toward xyloglucan, with a specific activity of 2375 U/mg, significantly higher than the typical range reported for GH12 xyloglucanases. The enzyme displayed optimal activity at pH 4.0 and 57 °C, with high stability in acidic conditions (pH 4–8) and moderate thermal stability. TpXEG12a demonstrated strict substrate specificity for xyloglucan, with no detectable activity against cellulose-related substrates, and primarily generated characteristic xyloglucan oligosaccharides (XXXG, XLXG/XXLG, XLLG) upon hydrolysis. Structural analysis revealed that TpXEG12a exists as a stable homodimer in solution, which likely contributes to its catalytic efficiency. Notably, TpXEG12a synergistically enhanced glucose release when combined with cellulase in lignocellulosic biomass degradation. These findings establish TpXEG12a as a promising candidate for industrial applications in biomass conversion, textile processing, and functional oligosaccharide production.

BACKGROUND: The dynamics of multi-axle amphibious wheeled transport and technological complexes (AWTTC) remain poorly understood, especially under variable adhesion and extreme driving conditions. Existing studies focus primarily on two- and four-axle vehicles, ignoring complex nonlinear effects of tire slip and interactions between axles, which limits control accuracy for heavy multi-axle vehicles. AIMS: To develop a comprehensive mathematical model of AWTTC dynamics that combines torque distribution between axles, real-time correction of wheel steering angles, and consideration of nonlinear effects of slip, to improve stability and controllability in transient and extreme conditions. MATERIALS AND METHODS: The article uses the following methods: theoretical and analytical study based on the equations of vehicle dynamics, simulation modeling of the motion of an AWTTC with an 8x8 wheel arrangement, comparative analysis of two steering schemes (1-2-0-0 and 1-2-3-4), assessment of the influence of speed, acceleration and steering angles on stability, verification of the model through the analysis of steady-state and transient modes. RESULTS: It was found that the difference in the slip angles of the outer eyes increases proportionally to the speed and the steering angle, reaching 10 degrees at a speed of 40 km / h. Deviation from the specified trajectory for the 1-2-0-0 scheme reaches 40%, which is 1.6 times higher than for the 1-2-3-4 scheme. In transient modes, an increase in the difference in slip angles by 15-20% was observed compared to the steady-state mode. CONCLUSIONS: The proposed model demonstrates that the integration of torque distribution and active steering reduces the trajectory deviation and improves the stability of the ACTCS. The results highlight the need for adaptive algorithms for multi-axle vehicles, especially in transient conditions.

ABSTRACT This paper studies the source term inversion of a time‐fractional Black‐Scholes equation, which is an ill‐posed problem. Under certain assumptions, we establish conditional stability results and derive the optimal error bound for the problem. The fractional Landweber iterative regularization method is employed to tackle this problem. Based on the selection rules of a priori and a posteriori regularization parameters, the optimal error estimates of regularization solutions are presented. Numerical examples demonstrate that the proposed regularization method is both effective and stable.

Metal halide perovskite single-crystal thin films (SCTFs) show great promise for high-stability optoelectronic applications since their long-range ordered stacking with large grains, few grain boundaries, and low defect density. However, their growth always requires high temperatures due to the inverse temperature solubility of the precursors, which increases the production costs, and decreases the crystal area and quality. Here, an assisting solvent strategy is developed to achieve in situ growth of large-area and high-quality perovskite SCTFs at low temperatures. Tetrahydrofuran serves as the assisting solvent in γ-butyrolactone to hydrogen bond with the precursor to improve the saturation solubility at room temperature. The resulting SCTFs show a maximum area of over 10 mm2, a low defect density of 4.42 × 1012 cm-3, and superior optoelectronic properties. The as-fabricated self-powered photodetectors exhibit a high detectivity of 4.01 × 1012 Jones, a large linear dynamic range of 127dB, and reproducible photocurrent response. Moreover, the devices show long-term stability in humid conditions, maintaining approximately 90% of the initial photocurrents after being stored for nearly 120 days in 60% relative humidity conditions. Our work not only presents state-of-the-art perovskite photodetectors with superior stability, but also demonstrates the huge potential of perovskite SCTFs in optoelectronic applications.

This study evaluates the potential of fish oil, extracted from Pangas (Pangasius pangasius) fish waste, as a sustainable fatliquoring agent in leather processing. Extraction with ethanol medium yielded 14.54% fish oil, compared to 12.30% with water. Upon sulfation, distinct FTIR peaks at 1160 cm-1 and modifications to the -OH band confirmed successful chemical transformation. Physicochemical analysis revealed increased acid value (11.22 mg KOH/g), saponification value (200.52 mg KOH/g), and specific gravity (0.93) for the sulfated fish oil. TGA analysis demonstrated significant stability, with around 20% residue retained above 400 °C, reflecting the robustness of the modified oil. Compatibility tests of sulfated fish oil fatliquor emulsion demonstrated stability in various aqueous, alkaline, and saline conditions, except under strong acid (10% H₂SO₄), where breakdown occurred. It also exhibited a hydrodynamic diameter of 342.3 nm and a zeta potential of -83.0 mV, highlighting the dispersion efficiency and electrostatic stability of the sulfated emulsion. Mechanical performance of leather processed with 4% fish oil fatliquor surpassed conventional fatliquoring agents, delivering tensile strength of 24.60 N/mm2, stitch tear resistance of 98.04 kg/cm, and grain crack load of 42.62 kg, alongside reduced surface defects under SEM imaging. Environmental impact assessment further validated the sustainability of this approach, as effluent from fish oil fatliquor treatment exhibited lower BOD, COD, and TDS values than those associated with commercial alternatives. Collectively, these findings position sulfated fish oil as a high-performing, eco-friendly fatliquoring agent capable of improving both leather quality and environmental outcomes.

Wildfires increasingly threaten the operation and stability of regional socio-economic systems, where infrastructure, population, and environmental conditions are tightly interconnected. To enhance operational efficiency and strengthen community resilience, this study develops an integrated optimization framework for wildfire evacuation system design based on mixed-integer programming. The model simultaneously determines the locations of primary and secondary shelters and establishes both main and backup evacuation linkages, forming a dual-stage structure that ensures continuous accessibility even under disrupted conditions such as road blockages or fire spread. Wildfire risk indices derived from topographic and environmental data are incorporated to support risk-aware and balanced shelter allocation. A case study of Uiryeong County, South Korea, demonstrates that the proposed framework effectively improves evacuation efficiency and system reliability, producing spatially coherent and adaptive evacuation plans under diverse disruption scenarios. The findings highlight how operation optimization can enhance socio-economic system resilience and sustainability when facing large-scale environmental disruptions.

Tea polyphenols (TP) offer health benefits, but their stability is compromised by sensitivity to environmental factors, limiting their applications. Developing stimulus-responsive delivery systems that precisely control TP release is essential. This study prepared novel hydrogel beads encompassing carboxymethyl chitosan (CMC), sodium alginate (SA), and MXene (Ti3C2Tx) using a blending method for the sustained release of TP. After being exposed to 808 nm near-infrared (NIR) radiation, the beads demonstrated excellent stability in simulated gastric conditions, resulting from the pH-dependent solubilization, facilitating controlled TP release under simulated intestinal conditions. The drug release kinetics conformed to the Ritger–Peppas model. Notably, CMC-SA-MXene@TP exhibited strong antioxidant activity and antimicrobial properties, effectively inhibiting the growth of S. aureus (ATCC 6538) and E. coli (ATCC 25922). Additionally, according to in vitro cellular assays, they exhibited good biocompatibility with normal liver cells (HL-7702) and could effectively inhibit hepatocellular carcinoma cells (HepG2). These hydrogel beads, featuring excellent pH and NIR responsiveness, biocompatibility, drug loading efficiency, antioxidant capability, and antibacterial activity, represent promising candidates for advanced wound dressings or oral drug delivery systems for modulating intestinal flora.

The article considers studies of health of elderly population as major element of global stability in conditions of impetuous demographic aging covering countries of the Global North and developing countries. It is noted that by 2050, the share of the elderly will exceed 20% of world population that requires reconsideration both national and international strategies in health care, social care, economics and political sustainability. The health of the elderly is considered both in medical terms and in broad social political context as resource maintaining fiscal resilience, decreasing epidemiological risks, strengthening solidarity of generations and forming inclusive societies. The article analyzes leading international initiatives, including the WHO program "The Decade of Healthy Aging", the UNDP and the UNFPA projects, regional strategies of the EU, ASEAN and other organizations. The key structural barriers are identified preventing implementation of such programs i.e. global inequality in access to medical services, poor inter-sectoral coordination, institutional gaps and insufficient digital inclusion of the elderly. The necessity of institutional development towards global age governance, including establishment of specialized UN body, development of international legal statements on the rights of the elderly and formation of global monitoring system. it is emphasizes that health of the elderly is to be considered as central axis of political and humanitarian agenda of the XXI century, shaping trajectory of sustainable development of global society.

Abstract This work investigates both direct and inverse problems of the variable-exponent sub-diffusion model, which attracts increasing attentions in both practical applications and theoretical aspects. Based on the perturbation method, which transfers the original model to an equivalent but more tractable form, the uniqueness of solutions to the variable-exponent subdiffusion equation with homogeneous Dirichlet boundary condition are established from its partial information, which results in the uniqueness of the inverse space-dependent source problem from local internal observation or partial boundary flux data. Then, based on the variational identity connecting the inversion input data with the unknown source function, we propose a weak norm and prove the conditional stability for the inverse problem in this norm. The iterative thresholding algorithm and Nesterov iteration scheme are employed to numerically reconstruct the smooth and non-smooth sources, respectively. Numerical experiments are performed to investigate their effectiveness.

Abstract This paper addresses the problem of recovering the spatial profile of the source in the complex Ginzburg–Landau equation (CGLE) from regional observation data at fixed times. We establish two types of sufficient measurements for the unique solvability of the inverse problem. The first is to determine the source term by using whole data at one fixed instant. Conditional stability is established by using the eigenfunction expansion argument. Next, using the analytic continuation method, both uniqueness and a stability estimate for recovering the unknown source can be established from local data at two instants. Finally, to effectively handle the complex-valued solutions of the CGLE, we propose a novel complex physics-informed neural networks (C-PINNs) framework. This approach designs complex-valued layers that inherently respect the complex structure of the governing equation, overcoming limitations of standard real-valued PINNs for such dissipative systems. Numerical experiments demonstrate the accuracy and efficiency of our C-PINNs algorithm in recovering the source term.

The Successive Over Relaxation (SOR) method is a well-known iterative method to solve the linear system Ax=b . One effective strategy for increasing the speed of convergence or even getting out of a possible recession is to use an effective preconditioner. With this perspective, in this paper, using a preconditioned version of the SOR method, we extract the numerical solutions of the one-dimensional Burgers' equation. At first, we discretize Burgers' equation by using some central and forward finite difference formulas. Then, we eliminate the non-linear term produced in the obtained differential equations by using an average formula called non-local arithmetic discretization scheme. Next, we examine the error analysis and conditional stability of the method. Finally, we modify the resulting system of linear equations with its preconditioned version. Theoretical and numerical results show that the present preconditioned method has increased the convergence rate significantly compared to the standard method and the resulting methods.

The links between the perception of acoustic signals and postural control remain largely unexplored, and the control models proposed to date have yet to assign these sensory inputs a role alongside visual, proprioceptive, and vestibular information. Research on this topic has produced varied conclusions, likely due to significant methodological differences. Our study makes novel contributions by aiming to determine the impact of the auditory system—specifically through the perception of echoes—on postural control during quiet standing and to identify the potential link between auditory perception and postural stability. To create controlled acoustic conditions, we developed an automated device representing a reflective object, positioned statically in two locations and dynamically moved in two directions relative to the participants. Eleven naive, blindfolded adult participants (mean age: 23 years ±2.2; mean height: 174 cm ±7.4) with normal hearing underwent kinematic (optoelectronic cameras) and kinetic (force plate) analyses in a semi-anechoic room. After each trial, participants reported their perception of the object’s presence, position, movement direction, and distance. Results demonstrated improved object perception and greater stability in dynamic conditions, particularly when the target moved towards the participants, compared to static conditions. However, no significant correlation between perception and postural stability was observed. Our findings suggest that acoustic information, especially through echo perception, could plays a role in postural control processes alongside visual, proprioceptive, and vestibular input. However, more controlled studies are necessary to examine the relationship between perception and postural stability.

Historically, horse breeding in Russia has always held a position of special significance and has been one of the most complex branches of animal husbandry, requiring great patience, knowledge, experience, and intuition. Even today, in developed countries, the standard of living is often measured, like a barometer, to a significant extent by the state and level of horse breeding development. Therefore, considering the changing conditions of horse use, it is necessary to conduct breeding work to improve domestic breeds, considering this the main objective of pedigree horse breeding. Currently, Kabardian breed horses have a fairly wide distribution range in several regions of the Russian Federation, as well as in countries such as Poland, Slovakia, the Czech Republic, Germany, Switzerland, France, and others. Interest in horses of this breed stems from their well-known qualities. As is known, they are distinguished by high endurance and a capacity for rapid recovery. To determine the level of adaptive qualities and condition stability of modern Kabardian broodmares under adverse conditions during winter pasture (herd-based) management, research was conducted at the Taik LLC farm in the Kabardino-Balkarian Republic (KBR), in a foothill zone. To more accurately determine live weight losses, the weighing method was applied, carried out three times during the winter period (at the beginning, middle, and end). The conducted research revealed a very high level of condition stability and adaptive qualities in modern Kabardian horses, while maintaining the conformation typical of the best stable-bred breeds. Mares with high stability were identified as follows: among young mares (5-7 years) - 64.9%, among those 8 years and older - 66.5%. Mares with medium stability accounted for 28.1% and 28.9% respectively. Horses with low stability totaled only 15 head, or 5.1% of the 296 head examined.

The 68th and 69th flights of NASA’s Ingenuity Mars Helicopter marked the first dedicated system identification flights of a powered-lift aircraft on another planet. Frequency-domain techniques, similar to those utilized in the Earth-based system identification campaign for Ingenuity, were employed for the first time under free-flight conditions on Mars. Chirp signals were injected into the swashplate cyclic controls for both legs of the two out-and-back flights. Frequency responses were computed from the flight data, using both the direct method and the joint-input–output approach, for the identification of stability and control derivatives in forward flight conditions. The resulting identified state-space models were compared against existing flight dynamics simulation models, showing excellent correlation in the higher-frequency range. External disturbances were seen to introduce a bias in the identified lower-frequency responses, which was partially mitigated using the joint-input–output method. These findings will inform future modeling and flight testing efforts of Mars rotorcraft.