Search Results (163)

Surface soil moisture (SM) is a critical factor in hydrological modeling, agricultural management, and numerical weather forecasting. This paper presents a highly effective soil moisture retrieval algorithm developed for the FY-3E (FengYun-3E) GNOS-R (GNSS Occultation Sounder II-Reflectometry) instrument. The algorithm incorporates a first-order vegetation model that considers vegetation density and volume scattering. Utilizing multi-angle GNOS-R observations, the algorithm derives surface reflectivity, which is combined with ancillary data on opacity, vegetation water content, and soil moisture from SMAP (Soil Moisture Active Passive) to optimize the retrieval process. The algorithm has been specifically tailored for different surface conditions, including bare soil, areas with low vegetation, and densely vegetated regions. The algorithm directly incorporates the angle-dependence of observations, leading to enhanced retrieval accuracy. Additionally, a new approach parameterizes surface roughness as a function of angle, allowing for refined corrections in reflectivity measurements. For vegetated areas, the algorithm effectively isolates the soil surface signal by eliminating volume scattering and vegetation effects, enabling the accurate estimation of soil moisture. By leveraging multi-angle data, the algorithm achieves significantly improved retrieval accuracy, with root mean square errors of 0.0235, 0.0264, and 0.0191 (g/cm³) for bare, low-vegetation, and dense-vegetation areas, respectively. This innovative methodology offers robust global soil moisture estimation capabilities using the GNOS-R instrument, surpassing the accuracy of previous techniques. Full article

With the increasing deployment of DC power systems, particularly in DC distribution systems, there is a growing demand for rapid and effective fault current limiting solutions. Conventional fault current limiters (FCLs) often suffer from limitations in terms of response time, size, and operational complexity. As a solution to these challenges, this paper proposes a hybrid FCL based on a pyro conductor switch (PCS), which combines passive limiting elements with an active switching mechanism. The proposed PCS FCL consists of a pyro fuse, an IGBT switch, a limiting inductor, and a damping resistor. Upon fault detection, the IGBT switch is first turned off to initiate current transfer into the limiting branch. Subsequently, the pyro fuse operates by explosively severing the embedded conductor using a pyrotechnic charge, thereby providing galvanic isolation and reinforcing current commutation into a high-impedance path. This operational characteristic enables effective fault current suppression without requiring complex control or real-time sensing. A detailed analysis using PSCAD/EMTDC simulations was conducted to evaluate the current limiting characteristics under fault conditions, and a prototype was subsequently developed to validate its performance. The simulation results were verified through experimental testing, indicating the limiter’s ability to reduce peak fault current. Furthermore, the results demonstrated that the degree of current limitation can be effectively designed through the selection of appropriate current limiting parameters. This demonstrates that the proposed PCS-based FCL provides a practical and scalable solution for improving protection in DC power distribution systems. Full article

This paper presents a non-fragile observer-based dissipative control strategy for the suspension systems of electric vehicles equipped with in-wheel motors, accounting for input delays, actuator faults, and observer gain uncertainty. Traditional control approaches—such as $H_{\infty }$, passive control, and robust feedback schemes, often address these challenges in isolation and with increased conservatism. In contrast, this work introduces a unified framework that integrates fault-tolerant control, delay compensation, and robust state estimation within a dissipativity-based setting. A novel dissipativity analysis tailored to Electric Vehicle Active Suspension Systems (EV-ASSs) is developed, with nonzero delay bounds explicitly incorporated into the stability conditions. The observer is designed to ensure accurate state estimation under gain perturbations, enabling robust full-state feedback control. Stability and performance criteria are formulated via Linear Matrix Inequalities (LMIs) using advanced integral inequalities to reduce conservatism. Numerical simulations validate the proposed method, demonstrating effective fault-tolerant performance, disturbance rejection, and precise state reconstruction, thereby extending beyond the capabilities of traditional control frameworks. Full article

This work presents a novel microfabrication process that addresses the interference of thiol groups on off-stoichiometry thiolene (OSTE) surfaces with the curing of polydimethylsiloxane (PDMS) by integrating the high-performance polymer Parylene-C. The process utilizes a Parylene-C coating to encapsulate the active thiol groups on the OSTE surface, enabling precise replication of PDMS microstructures. Based on this method, PDMS micropillar arrays and microwell arrays were successfully fabricated and applied in passive plasma separation and polymorphic crystal formation, respectively. The experimental results demonstrate that the plasma-separation chip efficiently isolates plasma from whole-blood samples with varying hematocrit (HCT) levels, achieving a separation efficiency of up to 57.5%. Additionally, the microwell array chip exhibits excellent stability and controllability in the growth of salt and protein crystals. This study not only provides a new approach for microfabricating microfluidic chips, but also highlights its potential applications in biomedical diagnostics and materials science. Full article

The global market for fresh, ready-to-eat products has grown rapidly, leading to some microbiological safety concerns. Lactic acid bacteria (LAB), along with their metabolites, represent a green alternative to chemical preservatives. For this purpose, the cell-free supernatant of LAB strains previously isolated from fruits and their potential antibacterial effects against pathogens commonly found in minimally processed fruit were evaluated. Based on the preliminary results, a mix of cell-free supernatants (CFSs) was applied as a postbiotic solution in minimally processed orange slices packed in a passive atmosphere. Different pathogenic strains were intentionally inoculated to evaluate their antimicrobial effect, and their trend was monitored. Microbiological and physico-chemical analyses were carried out at different times (3, 8, and 10 days) during cold storage. The CFSs obtained from Lactiplantibacillus plantarum and Leuconostoc mesenteroides strains highlighted an antibacterial activity against Escherichia coli and Staphylococcus aureus in both in vitro and in vivo tests, showing a reduction of 1 Log CFU/mL for E. coli and the disappearance of vital S. aureus. In conclusion, the CFSs can be proposed as an eco-friendly biopreservative for orange slices with a clean label, although their stability needs to be evaluated and their limits of application need to be ruled by specific legislation. Full article

Background: This study investigated the effects of preoperative maxillary plates on cleft width reduction in infants with unilateral cleft lip and palate and their control group. The study also aimed to compare the digital and manual methods in measurement of changes in maxillary segment positioning in sagittal and transverse dimensions using digital 3D models and conventional plaster casts. Methods: Twenty infants with unilateral cleft lip and palate and their control group of eleven infants with isolated cleft palate were enrolled in a prospective interventional study (2020 to 2024). Participants were treated with either active or passive maxillary plates. Sagittal, transversal and angular measurements were taken both manually as well as digitally at three time points: 24–48 h postnatal (T0), approximately at six months old (T1, immediately before surgery), and one year postoperatively (T2). Results: Significant reductions in cleft width were observed across all patients over the treatment period, regardless of the type of plate used (p < 0.001). The mean cleft width reduction was 5.050 mm. Infants treated with active plates had a larger reduction in cleft width than those with passive plates (p = 0.024), averaging 5.846 mm compared to 3.571 mm. Neither the side of the cleft nor the patient’s gender influenced the degree of cleft reduction (p = 0.884 and p = 0.245, respectively). The study found significant modifications in the maxilla’s transverse, sagittal, and angular dimensions (p < 0.001). When comparing sagittal growth, the study group differed from the control group (p = 0.004), with isolated cleft palate patients showing more substantial sagittal expansion. Additionally, the overall change in the ITT’ distance differed significantly between the study and control groups over time (p < 0.001). Cleft size at baseline did not affect the extent of changes within the cleft area. No significant discrepancies were found between digital and manual measurement methods, confirming the reliability of both. Conclusions: Active plates demonstrated greater efficacy in cleft reduction for wider and more divergent clefts, while passive plates were suitable for smaller clefts. Full article

Respiratory syncytial virus (RSV) is a leading cause of severe respiratory illness in infants, young children, as well as elderly and immunocompromised patients worldwide. RSV is classified into two major subtypes, RSV-A and RSV-B, and remains the most frequently detected pathogen in infants hospitalized with acute respiratory infections. Recent advances have brought both passive and active immunization strategies, including FDA-approved vaccines for older adults and pregnant women and new monoclonal antibodies (mAbs) for infant protection. Although significant progress has been made, the need remains for improved antiviral treatments, particularly for vulnerable infants and immunocompromised patients. Recent studies have identified multiple RSV mutations that confer resistance to current treatments. These mutations, detected in both in vitro studies and clinical isolates, often complicate therapeutic outcomes, underscoring the need for updated and effective management strategies. In this context, evaluating protein flexibility through tools like DisoMine provides insight into how specific mutations impact structural dynamics at binding sites, thus affecting ligand affinity. This review aims to synthesize these aspects, offering a comprehensive insight into ongoing efforts to counteract RSV and address the evolving challenge of drug resistance. Full article

Spasticity, characterized by elevated muscle tone, is commonly managed with botulinum toxin type A (BTX-A). However, BTX-A can paradoxically increase passive muscle forces, narrow muscles’ length range of force exertion (l_range), and elevate extracellular matrix (ECM) stiffness. C3 transferase, known to inhibit myofibroblast and fascial tissue contractility, may counteract ECM stiffening. This study investigated whether combining BTX-A with C3 transferase reduces active forces without altering passive forces or l_range. Additionally, we examined the isolated effects of C3 transferase on muscle levels. Male Wistar rats received injections into the tibialis anterior (TA): Control (n = 7, saline) and C3 + BTX-A (n = 7, 2.5 µg C3 + 0.1U BTX-A). TA forces were measured one month post-injection, and isolated C3 transferase effects were assessed in separate groups (Control and C3, n = 6 each). Active forces were 43.5% lower in the C3 + BTX-A group compared to the Control group. No differences between groups in passive forces (p = 0.33) or l_range (p = 0.19) were observed. C3 transferase alone had no significant effect on relative muscle mass (p = 0.298) or collagen content (p = 0.093). Supplementing BTX-A with C3 transferase eliminates BTX-A’s adverse effects at the muscle level. C3 transferase alone causes no atrophy or collagen increase, which are key factors in BTX-A-induced ECM stiffening. This novel neurodenervant formula shows promise for advancing spasticity management. Full article

Active and passive surveillance, followed by gene sequencing, continue to be used to identify a diverse range of novel bacteria, viruses, and other microorganisms in ticks with the potential to cause disease in vertebrate hosts following tick bite. In this study, we describe the isolation and characterization of a novel virus from Bothriocroton hydrosauri ticks collected from a blotched blue-tongue, Tiliqua nigrolutea. In an attempt to isolate rickettsia, the inoculation of Vero cell cultures with tick extracts led to the isolation of a virus, identified as a novel tick Orthomyxovirus by electron microscopy and gene sequencing. Transmission electron microscopic analysis revealed that B. hydrosauri tick virus-1 (BHTV-1) is a spherical orthomyxovirus, 85 nm in size. Multiple developmental stages of the virus were evident in vitro. Analysis of putative BHTV-1 amino acid sequences derived from a genomic analysis of virus-infected host cell extracts revealed the presence of six putative RNA segments encoding genes, sharing the closest sequence similarity to viral sequences belonging to the arthropod-borne Thogotovirus genus within the Orthomyxoviridae. Thogotoviruses are an emerging cause of disease in humans and animals following tick bite. The detection of this new thogotovirus, BHTV-1, in B. hydrosauri, a competent vector for human tick-borne infectious diseases, warrants follow-up investigation to determine its prevalence, host range, and pathogenic potential. Full article

The detrimental effects of low-frequency vibrations on the measurement accuracy of commercial high-precision instrumentation demand urgent resolution, particularly for instruments requiring <1 μm positioning stability. Conventional base-mounted active damping systems exhibit limitations in suppressing the structural resonance induced by passive isolators—especially when the environmental vibration intensity surpasses the standard thresholds. Therefore, in this study, we developed an innovative multi-mode control architecture to substantially enhance the vibration-damping capabilities of the DCSMS. The proposed methodology synergistically integrates foundation vibration isolators with embedded passive modules through a dual-stage spring-mass system optimization framework. Experimental validation combining ADAMS–MATLAB multi-physics co-simulation, complemented by a decoupling analytical control model based on the vibrational transmission characteristics of the source propagation path, substantiated the efficacy of the proposed control methodology. Full article

The rise of industrial machinery and military training activities has significantly contributed to low-frequency noise pollution, which can penetrate traditional passive noise isolation methods and pose serious health risks, including irreversible hearing damage. To address this challenge, this study proposes a hybrid active noise control (HANC) system, integrating an adaptive active noise control (AANC) module based on the filtered-x least mean squares (FxLMS) algorithm and an audio-balance control circuit (ABCC). The AANC system actively generates anti-noise signals to mitigate low-frequency disturbances, while the ABCC module enhances voice clarity and protects users from excessive impulse noise. MATLAB R2023b simulations and hardware implementations validate the system’s effectiveness, achieving a noise reduction of up to 21.8 dB in controlled environments. Additionally, the proposed feedback active noise control architecture ensures robust performance under dynamic noise conditions, improving stability and response time. By integrating both software-based adaptive filtering and hardware circuit design, this study provides a comprehensive noise mitigation solution with potential applications in military, industrial, and vehicular environments. Full article

As a common neurodegenerative disorder, Alzheimer’s disease (AD) manifests as progressive memory loss, cognitive deficits, and dementia in older adults. As the basis of the traditional Chinese medicinal herb Goji berries, Lycium barbarum polysaccharide (LBP) has been proven to exhibit multiple pharmacological activities, including antioxidant, neuroprotective, and anti-inflammatory effects. Evidence supports that LBP can enhance cognitive function and holds promise in counteracting AD. In order to determine the neuroprotective effects of LBP, this study was conducted on an AD rat model induced by intracerebroventricular injection of Aβ_1–42 peptides. From 24 h after induction until the end of the behavioral experiment, rats were orally administered LBP (150 and 300 mg/kg) once a day. Neurobehavioral parameters were evaluated starting 1 week after administration. After behavioral tests, rats were euthanized, and the whole brain and cortex were isolated to detect the variations in histopathology and biochemical parameters. LBP significantly reversed cognitive impairments, assessed through the Y-maze, Passive Avoidance Test (PAT), and Morris water maze (MWM) test, respectively. Furthermore, LBP not only attenuated NFκB, TNF-α, IL-1β, IL-6, AChE, and oxidative/nitrosative stress levels but also increased IL-4, IL-10, and ACh levels and ChAT activity in the cortex. HE staining also exhibited the neuroprotection of LBP. Our study findings imply that LBP may improve cognitive function through multiple mechanisms and is a potential anti-AD compound. Full article

Interferometric gravitational wave (GW) detectors are sophisticated instruments that require suspended mirrors to be effectively isolated from all forms of vibrations and noise. This isolation is crucial for enabling the detectors to function efficiently at low frequencies, which directly impacts their capacity to detect distant events from the universe’s past. To address this challenge, various suspension systems have been developed, utilizing passive, active, or hybrid control mechanisms. The effectiveness of these systems in suppressing noise determines the lowest detectable frequencies. Designing and managing mirror suspensions present significant challenges across all interferometric GW detectors. Detectors such as LIGO, VIRGO, TAMA300, KAGRA, and GEO600 implement unique suspension designs and techniques to enhance their performance. A comprehensive comparison of these systems would offer valuable insights. This paper provides an overview of the different suspension systems employed in major global interferometric GW detectors, alongside a brief examination of proposed future detectors. It discusses the rationale behind each design, the materials utilized, and other relevant details, serving as a useful resource for the gravitational wave detector community. Full article

The inevitable vibration caused by the normal operation of the spacecraft in orbit will interfere with sensitive instruments, such as space telescopes, reconnaissance cameras, and spatial interferometers. Severe vibrations can impact the accuracy and reliability of these sensitive instruments, potentially leading to mission failure. To address this issue, active–passive integrated six-dimensional orthogonal vibration isolation (APIVI) platform has been proposed for vibration isolation in spaceborne sensitive instruments. The APIVI platform is composed of three orthogonal isolation modules, each made up of an active piezoelectric actuator and passive rubber isolator. Taking into account the parameter uncertainties of the actual system, the H_∞ controller was designed, and the μ-synthesis method was proposed to establish a parameter uncertainty model for the APIVI platform. Finally, experimental studies were conducted on the APIVI platform. The results demonstrated the excellent vibration isolation performance of the APIVI platform, with the vibration isolation frequency band above 18 Hz. With the addition of active control, it was able to fully attenuate the first-order resonance peak of the system, with a maximum attenuation of 18 dB. Full article

The Active Radar Interferometer (AcRaIn) represents a novel approach in secondary radar technology, aimed at environments with high reflective clutter, such as pipes and tunnels. This study introduces a compact design minimizing peripheral components and leveraging commercial semiconductor technologies operating in the 24 GHz ISM band. A heterodyne principle was adopted to enhance unambiguity and phase coherence without requiring synchronization or separate communication channels. Experimental validation involved free-space and pipe measurements, demonstrating functionality over distances up to 150 m. The radar system effectively reduced interference and achieved high precision in both straight and bent pipe scenarios, with deviations below 1.25% compared to manual measurements. By processing signals at intermediate frequencies, advantages such as improved efficiency, isolation, and system flexibility were achieved. Notably, the integration of amplitude modulation suppressed passive clutter, enabling clearer signal differentiation. Key challenges identified include optimizing signal processing and addressing logarithmic signal attenuation for better precision. These findings underscore AcRaIn’s potential for pipeline monitoring and similar applications. Full article