Search Results (1,524)

Maintaining frequency regulation in interconnected power systems becomes increasingly difficult in the presence of nonlinear operating conditions. To address this issue, this study develops a hybrid load frequency control scheme in which a fuzzy fractional-order FOPI–FOPD controller is incorporated within a PIDF framework for a two-area LFC system. The controller parameters are optimized using the Dwarf Mongoose Optimization Algorithm (DMOA) and the Catch Fish Optimization Algorithm (CFOA), while the Integral of Time-Weighted Absolute Error (ITAE) is adopted as the performance criterion. The proposed strategy is examined under both linear and nonlinear scenarios, including the effects of Governor Dead Band (GDB) and Generation Rate Constraints (GRC). In the linear case, the DMOA-based design achieves an ITAE of 0.02939 with a tie-line settling time of 13.5478 s, whereas the CFOA-based design produces a bounded and convergent response with an ITAE of 0.03937 and a settling time of 14.4947 s. When GDB nonlinearity is introduced, the DMOA-tuned controller exhibits performance deterioration, yielding an ITAE of 0.1098 and a settling time of 19.0416 s, while the CFOA-tuned design shows more favorable time-domain performance with a lower ITAE of 0.05845 and a bounded settling time of 16.3595 s. These findings indicate that the CFOA-optimized PIDF–Fuzzy FOPI–FOPD controller provides an effective LFC solution under the examined nonlinear operating conditions. Full article

Background/Objectives: Static cold storage (SCS) remains the standard method of kidney preservation. As a referral transplant center, we frequently receive kidneys initially preserved with SCS and subsequently initiate prolonged hypothermic machine perfusion (HMP) to extend allocation time and optimize recipient matching. The clinical impact of this sequential preservation strategy remains incompletely defined. To compare outcomes between kidneys preserved with SCS followed by prolonged HMP (SCS+HMP) and SCS alone. Methods: This single-center retrospective study included 200 adult recipients of kidney transplants from brain-dead donors (67 SCS+HMP; 133 SCS). Outcomes were primary graft non-function (PNF), delayed graft function (DGF), patient and death-censored graft survival, and renal function over 24 months. Univariable and multivariable analyses identified predictors of DGF. Propensity score matching was performed to adjust for baseline imbalances. Results: In the SCS+HMP group, grafts underwent a median of 244 min of SCS followed by 1300 min of HMP, resulting in longer total cold ischemia time than SCS alone (1545 vs. 1104 min; p < 0.001). After matching, 51 pairs (n = 102) were analyzed. In the matched cohort, PNF occurred in 2 patients (3.9%) in the SCS+HMP group and 3 patients (5.9%) in the SCS group (p = 1.0). DGF occurred less frequently in the SCS+HMP group than in the SCS group (17.6% vs. 39.2%; p = 0.027). In multivariable Firth penalized logistic regression, HMP was independently associated with lower odds of DGF (OR 0.34; 95% CI 0.13–0.82). During the 24-month follow-up, patient survival, death-censored graft survival, and creatinine trajectories were comparable between groups. Conclusions: Sequential HMP after initial SCS enables extended preservation and was associated with a lower incidence of delayed graft function. This strategy does not compromise patient survival, death-censored graft survival, or renal function at 24 months. Full article

Hydrogen combustion is known to be fast compared to traditional hydrocarbon fuels. The fast combustion leads to a higher thermal efficiency. In this research a 600 cc single cylinder hydrogen engine was tested at 1250 rpm, lambda = 2 and 3, and three load levels (load was represented by Manifold Absolute Pressure (MAP); MAPs tested were 75, 95 and 120 kPa) and compared to operation with gasoline and propane. The fast burn duration (Mass Fraction Burnt MFB10% to MFB90%) and the MFB 50% were determined and analyzed. The hydrogen MFB50% location for Minimum Timing for Best Torque (MBT) was found to occur at around the typical 8 Crank Angle Degrees (CADs) After Top Dead Center (ATDC). Measurements of ignition delay based on the fast data direct measurement of spark ignition coil current drop to the change in polarity of net heat release are presented. With shifts towards direct injection and higher injection pressures, consideration was given to the hydrogen pressurization penalty, where it was calculated that pressurizing hydrogen to 100 bar at the flow required for lambda = 2 operation is 2.3 bar, i.e., higher than the Friction Mean Effective Pressure (FMEP)! Furthermore, hydrogen is widely cited to have a higher heat loss than typical hydrocarbon fuels. In this paper, detailed analyses at lambda 2 and lambda 3 showed that hydrogen in fact has lower heat losses. Full article

The construction industry requires sustainable building materials to reduce its environmental impact. While using these materials in newly constructed structures primarily focuses on environmental benefits, their application in the protection of architectural heritage presents an additional requirement. These materials must be physically and chemically compatible with historical substrates to ensure the longevity of the structure. Therefore, developing eco-friendly and compatible restoration materials is a significant concern. This study aims to produce artificial aggregates to develop lightweight concrete for structural interventions and reduce natural resource consumption (i.e., minimizing the destructive extraction of natural river sand and crushed stone aggregates). Magnesium-based binders were used to mimic the carbonation process of historical lime mortars. The binders were mixed with water, shaped into coarse pellets, and cured in a ${CO}_2$ incubator for 3 and 14 days before being used in concrete production. The results show that using artificial aggregates decreased the concrete density by approximately 16.5%. Since reducing the dead load improves the seismic safety of historical masonry structures, this reduction is critical. Although the compressive strength decreased compared to natural aggregate concrete, the 14-day cured series achieved a strength of 34.7 MPa. This demonstrates that the material can be used in restoration interventions where stiffness compatibility is essential (e.g., vault infills, ring beams, or floor screeds). At the same time, since magnesium-based artificial lightweight pellets have ${CO}_2$ sequestration capacity, they can be used as a carbon-negative solution for both historical structures and broader civil infrastructure. Full article

Background/Objectives: Retinoblastoma (RB) is the most common primary intraocular malignancy in children, with treatment limited by chemoresistance and therapy-related toxicity. Enhancing the efficacy of conventional chemotherapeutics while reducing dose-related adverse effects is crucial. This study investigates the chemosensitizing potential of rosmarinic acid (RA), a natural polyphenolic compound, in combination with cisplatin (Cis) in RB models. Methods: The antiproliferative and synergistic effects of RA and Cis were evaluated in Y79 and WERI-Rb1 RB cell lines using MTT assays and Combination Index (CI) analysis. Apoptosis and oxidative stress were assessed by Annexin V-FITC/PI flow cytometry and intracellular reactive oxygen species (ROS) measurements, respectively. Three-dimensional (3D) tumor spheroids were generated from Y79 cells for in vitro validation using spheroid size analysis, ATP-based viability assays, and live/dead fluorescence staining. The ROS dependency of cytotoxicity was further examined using N-acetylcysteine (NAC) pretreatment. Cytokine secretion was analyzed by ELISA, and apoptosis-related gene expression was assessed by qRT-PCR. Results: RA and Cis reduced cell viability in a dose- and time-dependent manner, while their combination induced significantly enhanced cytotoxicity, confirmed by CI values < 1. Combined treatment increased apoptotic populations, elevated intracellular ROS, and upregulated Caspase-3 and Caspase-9. These effects were maintained in 3D spheroids, with reduced spheroid size and impaired integrity. NAC pretreatment attenuated ROS generation and partially rescued cell viability, indicating a ROS-dependent, but not exclusive, contribution to cytotoxicity. Conclusions: RA synergistically enhances cisplatin-induced anticancer effects in RB through oxidative stress, engagement of intrinsic (mitochondria-associated) apoptotic signaling, and reduction of tumor cell-derived inflammatory and angiogenic mediators. These findings highlight the potential of RA and Cis combination as a chemosensitizing strategy for RB therapy, warranting further in vivo evaluation. Full article

For effectively assessing blood, red blood cell (RBC) aggregation and blood viscosity have been measured in microfluidic environments. However, the previous methods still face several challenges (dead-volume loss, RBC sedimentation, hematocrit-sensitive blood velocity, and precise flow rate control). In this study, a novel method is suggested to resolve several issues. Air cavity (V_air = 250 μL) is secured above the blood column (at least 100 μL) loaded into a driving syringe. To probe RBC aggregation and blood viscosity, a microfluidic chip consists of a main channel ($\dot{\gamma }$ > 1000 s⁻¹) and an aggregation channel ($\dot{\gamma }$ < 50 s⁻¹). Blood is supplied into a microfluidic chip with two-step blood delivery (i.e., air compression for RBC aggregation, and syringe pump for blood viscosity). RBC aggregation index and blood viscosity are obtained from time-lapse image intensity and blood flow rate in both channels. As performance demonstrations, first, the measurement accuracy of fluid viscosity is validated with glycerin solution. Then, the present method is adopted to probe the difference in hematocrit and dextran concentration. At last, the proposed method is employed to detect heat-shocked RBCs (45~50 °C for 40 min). In conclusion, the proposed method has the ability to accurately measure substantial changes in RBCs or blood medium. Full article

Indoor positioning in hospitals is challenging because global navigation satellite systems signals are unavailable and existing solutions struggle with complex indoor propagation and high maintenance requirements. Fingerprinting-based methods using Wi-Fi, Bluetooth Low Energy (BLE), or magnetic field depend on extensive site surveys, while time or angle-based systems such as ultra-wide band, angle of arrival, and Wi-Fi round trip time require additional infrastructure. Recent machine learning approaches improve performance but remain limited by Pedestrian Dead Reckoning (PDR) drift and unstable spatial representations. This study proposes an AI-generated spatial pattern matching framework that integrates an AI-based PDR model with BLE Received Signal Strength Indicator (RSSI) to construct a user RSSI surface. Spatial similarity between user-generated patterns and the pre-built radio map is evaluated using Surface Correlation (SC), and a bi-directional candidate generation strategy with SC-based heading correction is employed to mitigate inertial drift. Experiments in a real hospital setting show that the proposed method achieves robust and accurate localization even in complex indoor environments where conventional fingerprinting and PDR techniques often fail. The results indicate that combining AI-driven inertial modeling with SC-based spatial pattern matching offers a practical and infrastructure-friendly solution for hospital indoor positioning. Full article

In response to the challenges of low detection efficiency, high omission rate in small target detection and high model complexity in wood surface defect detection, this study proposes a lightweight detection model based on YOLO, which integrates a dual-path integrated attention network (DFA-Net). The model is built on the enhanced YOLOv5 framework and achieves a balance of accuracy and efficiency through the collaborative optimization of multiple modules. Specifically, this paper designs a dual-path downsampling convolutional module (DP-DCM), combining wavelet transform with dual-path feature fusion to improve multi-scale feature extraction capabilities while reducing the number of parameters. Next, a fusion attention module (FAM) is designed to dynamically focus on defect features in complex backgrounds through channel and spatial attention mechanisms. Furthermore, a focal modulation network (FMNet) is introduced to enhance the robustness of the augmentation model in detecting small defects. Finally, the NWD Loss function is used to mitigate the localization bias of small targets. Experimental results show that the improved model achieves a 92.8% mAP rate on five types of defect datasets (dead knots, live knots, cracks, notches, and marrow). Compared with the baseline model, YOLOv5s, the performance of this model has been improved by 6.5%. The model runs at a detection speed of 105 FPS, and the number of parameters is only 5.8 million, which is better than models such as YOLOv8 and YOLOv9-t. While maintaining a lightweight design, this method achieves high precision and real-time performance on a consumer-grade GPU platform, indicating its practical applicability in automated wood inspection scenarios. The proposed approach provides an efficient solution for intelligent wood sorting, contributing to improved wood utilization and enhanced processing automation. Full article

This paper focus on the high accuracy force control of electro-hydraulic proportional load simulator (EHPLS). Firstly, to weaken the influence of the unknown dead zone of the proportional valve, a mathematic model with a smooth inverse dead zone was constructed. Then, finite-time prescribed performance function, of which the desired steady-state value can be achieved within finite time, is defined to impose constraints on the tracking error, while the neural network feedback is introduced to compensate for the unknown dynamic, which can ensure the tracking accuracy further improved for the entire tracking process in the presence of unknown dead-zone parameters, unknown system parameters and disturbance. Finally, through design modification, the proposed control technologies are realized based on the output feedback signal. Comparative simulations under two desired force trajectories are carried out to verify the effectiveness of the proposed controller. Full article

The illegal wildlife trade remains a significant threat to biodiversity in South Africa. The poaching of native species in the country has increased over the years, primarily driven by the demand for abalone, rhino horns, and pangolin scales. This study analysed TRAFFIC wildlife crime records between 1984 and 2025 to identify hotspots, trends in enforcement over time, and the most affected species. We found that provinces such as Gauteng and KwaZulu-Natal have the highest diversity of species affected, while the Western Cape recorded the highest number of incidents, predominantly seizures. Seizure was the most common wildlife activity, followed by poaching and illegal harvesting, with fewer cases of smuggling, breeding, and prosecution. A total of 50 species across nine animal classes were impacted, with white rhinoceros (Ceratotherium simum (Burchell, 1817)), abalone (Haliotis midae (Linnaeus, 1758)), lion (Panthera leo (Linnaeus, 1758)), and ground pangolin (Smutsia temminckii (Smuts, 1832)) among the most frequently targeted. Correlation analysis revealed a strong positive relationship between seizures and arrests (Pearson’s r = 0.90, p = 0.001) across provinces. This indicates a substantial strengthening of law-enforcement activity across provinces, likely driven by enhanced detection or reporting, as reflected in a rising proportion of cases resulting in arrests. Species such as elephants and pangolins were associated with enforcement outcomes, particularly those involving horns, tusks, scales, and dead specimens. There is a need for targeted interventions in high-risk areas, and provinces must collaborate in combating the wildlife trade. Limitations in data completeness and species representation suggest the need for improved surveillance and reporting mechanisms to fully understand and combat illegal wildlife trade in South Africa. Full article

We report the isolation and coding complete genome sequences of a new CHeRI orbivirus from the spleen of a dead farmed white-tailed deer in Florida whose death was attributed to an infection by mule deerpox virus. Phylogenetic and genetic analyses support this new virus as the fifth strain of the CHeRI orbivirus 3 species, and we designated it CHeRI orbivirus 3–5. While our previous detections and isolations of CHeRI orbiviruses were from deer spleens that also contained epizootic hemorrhagic disease virus-2, or in one case, Hardee County ephemerovirus 1, no deerpox virus was isolated from the spleen of the animal in this report, marking the first time we have isolated a CHeRI orbivirus without a co-infecting agent. Full article

As an important biomass material, bamboo is susceptible to fungal infection during use, leading to severe deterioration. The white-rot fungus Schizophyllum commune is one of the world’s most widely distributed fungi, which preferentially colonizes dead or senescent bamboo tissues. However, the mechanism of the influence of the S. commune infection on the mechanical and chemical properties of bamboo remains unexplored. This research systematically examined the temporal effects (0, 30, 60, and 90 days) of S. commune QP33 infection on bamboo’s mechanical properties and chemical composition using various characterization methods. Results showed that S. commune QP33 secreted key lignin-modifying enzymes (laccase and lignin peroxidase) and hemicellulases (xylanase). Mass loss of bamboo increased progressively with infection time, reaching 13.33% after 90 days. Decayed bamboo showed distinct mechanical deterioration patterns, including a sharp initial drop in bending strength and a continuous decline in tensile strength. Microstructural and chemical analyses revealed that the fungus preferentially degraded lignin and hemicellulose. This selective degradation led to cell wall delamination and pore formation, ultimately causing the observed macroscopic mechanical deterioration. Our study provides critical insights into the biodeterioration mechanism of bamboo by S. commune and offers valuable guidance for bamboo preservation and high-value utilization. Full article

We report a dual-readout self-resetting CMOS image sensor that achieves a signal-to-noise ratio (SNR) exceeding 70 dB and resolves sub-percent optical contrast variations by effectivly suppressing reset artifacts. The proposed sensor employs a Dual-Readout architecture with two independent scanners operating with a temporal offset; while one readout system is in the self-reset “dead time”, the other remains active, thereby physically ensuring continuous data acquisition. To minimize pixel area while achieving high reconstruction accuracy, a minimum frame-to-frame difference algorithm is utilized for signal restoration without requiring in-pixel counters. A prototype chip fabricated in a 0.35-$\mathsf{\mu }$m process demonstrated SNR characteristics near the shot-noise limit, with a peak SNR exceeding 70 dB. Vascular phantom experiments using a carbon black suspension successfully visualized ±0.25% contrast fluctuations—dynamic signals previously undetectable by conventional sensors. This device provides a powerful platform for high-precision bio-imaging applications, including brain surface blood flow monitoring, where both wide dynamic range and high SNR are essential. Full article

The deployment of Discrete Variable Quantum Key Distribution (DV-QKD) in high-traffic, short-reach environments, such as intra-data center networks, is currently constrained by the saturation of single-photon detectors. While CMOS Single-Photon Avalanche Diodes (SPADs) offer a cost-effective solution, their Secure Key Rate (SKR) is limited by detector dead time. To the best of the authors’ knowledge, this work is the first to derive a generalized detection rate model for SiPMs that addresses the dead-time bottlenecks of gigahertz-rate quantum cryptography. While methods for managing deadtime via active optical switching have been proposed, our model quantifies the benefits of passive spatial multiplexing inherent in standard SiPM arrays. Furthermore, contrasting with models designed to optimize energy resolution or characterize nonlinear charge response to light pulses, our work focuses on maximizing the detection count rate. We derive exact detection rate models for both analog (paralyzable) and digital (non-paralyzable) SiPM architectures, incorporating correlated noise sources such as optical crosstalk and afterpulsing. Simulation results indicate that SiPMs can increase detection rates by over an order of magnitude compared to single SPADs. Full article

Brushless DC (BLDC) motors are widely used in mobile robotics and off-road vehicles due to their high efficiency, reliability, and compactness. However, achieving robust, high-performance speed control in embedded environments remains challenging due to nonlinearities, dead-time effects, parameter uncertainties, and strict real-time constraints. This paper presents a comprehensive experimental study of classical and robust control strategies for BLDC motor speed control, fully implemented on an FPGA platform. Classical PI and PID controllers tuned using Ziegler–Nichols, Cohen–Coon, and Chien–Hrones–Reswick methods are first investigated and discretized using both Zero-Order Hold (ZOH) and Tustin (bilinear) approximations. Model-based approaches, including IMC-based PID controllers, are then introduced to enhance robustness. In addition, a robust two-degree-of-freedom dead-time compensator (DTC) is implemented to explicitly address dead-time uncertainties inherent to inverter-based motor drives. All controllers are implemented using fixed-point arithmetic on a Xilinx Nexys A7 FPGA and validated experimentally on a BLDC motor test bench representative of semi-autonomous robotic applications. Performance is evaluated through time-domain responses and quantitative indices, including ISE, ITAE, I, control effort, and FPGA resource utilization. Experimental tests under controlled DC bus voltage disturbances are conducted to assess disturbance rejection capability and robustness under realistic operating conditions. Experimental results demonstrate that Tustin discretization consistently improves tracking performance, while IMC-PID and DTC strategies provide superior robustness against dead-time and modeling uncertainties, making them particularly suitable for embedded FPGA-based motor control. Full article