Search Results (308)

This work proposes an effective control technique for enhancing the stability of Doubly Fed Induction Generator-Based Wind Turbines (DFIG-WTs) connected to the grid during voltage sag and swell events, ensuring the reliable and efficient operation of wind energy systems integrated with the grid. The proposed approach integrates a Dynamic Voltage Restorer (DVR) in series with a Wind Turbine Generator (WTG) output terminal to enhance the Fault Ride-Through (FRT) capability during grid disturbances. To develop a flexible control strategy for both unbalanced and balanced fault conditions, a combination of feedforward and feedback control based on a sliding mode control (SMC) for DVR converters is used. This hybrid strategy allows for precise voltage regulation, enabling the series compensator to inject the required voltage into the grid, thereby ensuring constant generator terminal voltages even during faults. The SMC enhances the system’s robustness by providing fast, reliable regulation of the injected voltage, effectively mitigating the impact of grid disturbances. To further enhance system performance, Model Predictive Control (MPC) is implemented for the Rotor-Side Converter (RSC) within the back-to-back converter (BTBC) configuration. The main advantages of the predictive control method include eliminating the need for linear controllers, coordinate transformations, or modulators for the converter. Additionally, it ensures the stable operation of the generator even under severe operating conditions, enhancing system robustness and dynamic response. To validate the proposed control strategy, a comprehensive simulation is conducted using a 2 MW DFIG-WT connected to a 120 kV grid. The simulation results demonstrate that the proposed control approach successfully limits overcurrent in the RSC, maintains electromagnetic torque and DC-link voltage within their rated values, and dynamically regulates reactive power to mitigate voltage sags and swells. This allows the WTG to continue operating at its nominal capacity, fully complying with the strict requirements of modern grid codes and ensuring reliable grid integration. Full article

In shallow groundwater areas, the freeze–thaw process can easily exacerbate soil salinization. The variations and migrations of Na⁺, K⁺, Ca²⁺, Mg²⁺, Cl⁻, SO₄²⁻, and HCO₃⁻ at the depth of 0–100 cm under shallow groundwater depth (2.63–2.87 m) during the freeze–thaw period were analyzed. And a multi-index comprehensive evaluation method based on factor analysis was employed to investigate the soil salinization degree. The results show that K⁺, Mg²⁺, and HCO₃⁻ exhibited surface enrichment during the freeze–thaw period, while Na⁺, Cl⁻, and SO₄²⁻ accumulated in the frozen layer during the freezing stage. However, there is no surface enrichment of Ca²⁺. During the freezing stage, Mg²⁺ and Cl⁻ exhibited the strongest migration capabilities among cations and anions, respectively. During the thawing stage, K⁺ and HCO₃⁻ were the cation and anion with the highest ionic migration capabilities, respectively. Total salinity (TS), Cl⁻, SO₄²⁻, HCO₃⁻, Na⁺, K⁺, Mg²⁺, and residual sodium carbonate (RSC) were identified as the dominant factors influencing the salinization degree during the freeze–thaw period. During the freezing stage, soil salt ions predominantly migrated from the unfrozen to the frozen layer, and the salinization degree in the frozen layer increased with the development of the frozen layer. In the thawing stage, soil salt ions migrated upward from the thawing front, and the salinization degree at the depth of 0–30 cm increased. This study provides insights for the prevention and control of soil salinization in arid regions. Full article

Aiming at the transient overcurrent problem faced by doubly-fed induction generators (DFIGs) during continuous voltage fault ride-through, a segmented control strategy based on the rotor side converter (RSC) is proposed. First, through theoretical analysis of the relationship between stator current and transient induced electromotive force (EMF) in each stage of continuous faults, a feedforward control strategy based on the transient component of stator current is proposed. The observable stator current is extracted for its transient component, which is used as a rotor voltage compensation term to effectively counteract the influence of transient EMF. Meanwhile, a fuzzy control algorithm is introduced during the low voltage ride-through (LVRT) stage to dynamically adjust the virtual resistance value, enhancing the system’s damping characteristics. Studies show that this strategy significantly suppresses rotor current spikes in all stages of voltage ride-through. Finally, simulation results verify that the proposed method improves the ride-through performance of DFIG under continuous voltage faults. Full article

Background and Objectives: To evaluate the feasibility and clinical outcomes of a novel non-mesh robot-assisted sacrocolpopexy (RSC) using autologous round ligament (ARL) grafts in patients with pelvic organ prolapse (POP). Materials and Methods: This retrospective study included 92 patients who underwent non-mesh RSC with ARL grafts at Kagoshima University Hospital between August 2020 and June 2024. All patients met the inclusion criteria for symptomatic POP-Q stage II or higher and elected to undergo non-mesh RSC. The procedures were performed using the da Vinci^® Xi or the hinotori™ Surgical Robot System. The clinical characteristics, operative data, complications, and recurrence rates were analyzed. Results: ARL harvesting was feasible in all patients, and the non-mesh RSC procedure was completed without conversion to open surgery or any intraoperative complications. The median operative time was 251 min, and the median blood loss was 30 mL. Postoperative complications of Clavien-Dindo grade ≥ 2 occurred in five patients (5%), all of whom developed pelvic infections. De novo stress urinary incontinence was observed in one patient (1%). POP recurrence occurred in seven patients (8%) during a median follow-up of 3 months (range, 3–18 months), all of whom presented with cystocele. Five patients underwent reoperation, and two were managed conservatively. All patients experienced postoperative symptomatic improvement. A higher BMI and advanced POP-Q stage were significant predictors of recurrence. Conclusions: This is the first report of non-mesh RSC using an ARL graft. The procedure is feasible and effective, avoids the use of synthetic mesh, and offers short-term outcomes comparable to those of mesh-based RSC. ARL-based RSC represents a promising alternative, especially for patients at risk of mesh-related complications. Long-term follow-up is required to confirm durability. Full article

Effluents from wastewater treatment plants (WWTPs) represent a potential pollution risk to surface waters. Moreover, the growing practice of using treated wastewater for irrigation has recently received increased attention in terms of its suitability, raising concerns about its impact on soil health, agricultural productivity, and human well-being. The aim of this study is to apply a comprehensive approach to assess the impact of wastewater from a Romanian WWTP on surface water quality and its suitability for irrigation practices. For this purpose, a set of physico-chemical parameters were analyzed, and a Water Quality Index (WQI) was developed based on Principal Component Analysis (PCA). The irrigation suitability of the effluent was further assessed using key parameters (electrical conductivity—EC; total dissolved solids—TDSs; turbidity; Biochemical Oxygen Demand—BOD₅) and specific irrigation indices (Sodium Adsorption Ratio—SAR; Permeability Index—PI; Residual Sodium Carbonate—RSC; Sodium percentage—%Na; Kelly’s ratio—KR). The results for the surface water quality indicated high contents of Na⁺ (10.2–42.5 mg/L), Cl⁻ (11.9–48.4 mg/L), and SO₄²⁻ (10.7–68.5 mg/L) downstream of the wastewater discharge point. The WQI, which reflects overall water quality for environmental health, showed excellent water quality, with a mean of 34 upstream and 47 downstream, suggesting the potential impact of treated wastewater discharge downstream. However, the irrigation indices revealed elevated sodium levels in the effluent, with %Na (up to 86%) categorizing 70% of the samples as unsuitable, while KR (up to 6.2) classified all samples as unsuitable. These findings suggest that despite a low impact on the river water, elevated sodium levels in effluent may limit suitability for irrigation, highlighting the importance of monitoring effluent water reuse. Full article

Adhesion between Schwann cells (SCs, a type of glial cell in the peripheral nervous system) and their underlying substrates is a fundamental process that holds critical importance for the proper functioning of the peripheral nervous system. Conducting further in-depth research into the adhesion mechanisms of nerve cells is of paramount significance, as it can pave the way for the development of highly effective biomaterials and facilitate the repair of nerve injuries. Thyroid Receptor Interaction Protein 6 (TRIP6), a member of the ZYXIN family of LIM domain-containing proteins, serves as a key component of focal adhesions. It plays a pivotal role in regulating a diverse array of cellular responses, including the reorganization of the actin cytoskeleton and cell adhesion. Accumulated data indicate that RSC96 cells (rat Schwann cells), which are rat Schwann cells, exhibit integrin-based mechanosensitivity during the initial phase of adhesion, specifically within the first 24 h. This enables the cells to sense and respond to alterations in matrix stiffness. The results of immunofluorescence staining experiments revealed intriguing findings. An increase in matrix stiffness not only led to significant changes in the morphological parameters of RSC96 ells, such as circularity, aspect ratio, and cell spreading area, but also enhanced the expression levels of TRIP6, focal adhesion kinase (FAK), and vinculin within these cells. These changes collectively promoted the adhesion of RSC96 cells to the matrix. Furthermore, when TRIP6 expression was silenced in RSC96 cells cultured on hydrogels, a notable decrease in the expression of both FAK and vinculin was observed. This, in turn, had a detrimental impact on cell adhesion. In summary, the present study strongly suggests that TRIP6 may play a crucial role in promoting the adhesion of RSC96 cells to polyacrylamide hydrogels with varying stiffness. This research not only offers a fresh perspective on the study of the integrin-mediated force regulation of cell adhesion but also lays a solid foundation for potential applications in tissue engineering, regenerative medicine, and other related fields. Full article

This study investigated the response of pepper seeds with varying seed coat conditions (SCs) to dielectric barrier discharge plasma treatment (PT). The experimental design was a split plot with three replications. The primary plot factor was the SC (normal seeds [NMS], nicking at the hilum part [NHP], and removed seed coat [RSC]), while the subplot factor was the plasma exposure time (0.4–2.0 s/cm), including a control, to determine the effects on seed viability, germination, and vigor. The results indicate that NMS seeds exhibit the highest performance in terms of seed viability. The NMS and NHP had statistically significantly higher seed germination, electrical conductivity, radical emergence, and germination index at 14 days after sowing, and the shoot length measured longer than RSC. Plasma exposure at 1.2 s/cm improved germination and vigor, whereas 2.0 s/cm exposure significantly decreased seed viability and increased the number of abnormal seedlings. The interaction between SC and PT significantly affected seedling abnormalities, with RSC seeds being more vulnerable to damage under prolonged exposure. These findings highlight the crucial role of seed coat integrity in maintaining seed quality and suggest that carefully controlled PT can be a promising and sustainable method to enhance pepper seed performance. Full article

In this work, we propose an improved network, RSCS6D, for 6D pose estimation from RGB-D images by extracting keypoint-based point clouds. Our key insight is that keypoint cloud can reduce data redundancy in 3D point clouds and accelerate the convergence of convolutional neural networks. First, we employ a semantic segmentation network on the RGB image to obtain mask images containing positional information and per-pixel labels. Next, we introduce a novel keypoint cloud extraction algorithm that combines RGB and depth images to detect 2D keypoints and convert them into 3D keypoints. Specifically, we convert the RGB image to grayscale and use the Sobel edge detection operator to identify 2D edge keypoints. Additionally, we compute the Curvature matrix from the depth image and apply the Sobel operator to extract keypoints critical for 6D pose estimation. Finally, the extracted 3D keypoint cloud is fed into the 6D pose estimation network to predict both translation and rotation. Full article

This study focuses on assessing the hydrogeochemical characteristics and irrigation suitability of groundwater in the Ras El Aioun and Merouana districts, using an integrated approach that combines physicochemical analysis, machine learning (ML), and Geographic Information Systems (GISs). Thirty groundwater samples were collected in June 2023 and subjected to extensive analyses, including major ions (Ca²⁺, Mg²⁺, Na⁺, K⁺, HCO₃⁻, Cl⁻, SO₄²⁻), pH, TDS, alkalinity, and hardness. Hydrochemical facies analysis revealed that the Ca-HCO₃ type was dominant (93.33%), with some samples exceeding FAO limits, particularly for Na⁺, K⁺, SO₄²⁻, Cl⁻, Mg²⁺, and HCO₃⁻. Assessment of groundwater irrigation suitability revealed generally favorable conditions based on three key parameters: all samples (100%) were classified as excellent based on the Sodium Adsorption Ratio (SAR < 10), 70% showed good-to-permissible status by Sodium Percentage (Na% < 60), and 83.3% were within safe limits for Residual Sodium Carbonate (RSC < 1.25 meq/L). However, the Permeability Index (PI > 75%) categorized 96.7% of samples as unsuitable for long-term irrigation due to potential soil permeability reduction. Additionally, Total Hardness (TH < 75 mg/L) indicated predominantly soft water characteristics (90% of samples), particularly in the central study area, suggesting possible limitations for certain agricultural applications that require mineral-rich water. GIS-based spatial analysis showed that irrigation suitability was higher in the eastern and western regions than in the central zone. Advanced machine learning algorithms provide superior predictive capability for water quality parameters by effectively modeling complex, non-linear feature interactions that conventional statistical approaches frequently fail to capture. Three ML models—Support Vector Regression (SVR), Random Forest (RF), and Extreme Gradient Boosting (XGBoost)—were used to predict the Irrigation Water Quality Index (IWQI). XGBoost outperformed the others (RMSE = 2.83, R² = 0.957), followed by RF (RMSE = 3.12, R² = 0.93) and SVR (RMSE = 3.45, R² = 0.92). Integrating ML and GIS improved groundwater quality assessment and provided a robust framework for sustainable irrigation management. These findings provide critical insights for optimizing agricultural water use in water-scarce regions. Full article

Bimetals—materials composed of two metal components with dissimilar standard reduction–oxidation (redox) potentials—offer unique electronic, optical, and catalytic properties, surpassing monometallic systems. These materials exhibit not only the combined attributes of their constituent metals but also new and novel properties arising from their synergy. Although many reviews have explored the synthesis, properties, and applications of bimetallic systems, none have focused exclusively on iron (Fe)- and aluminum (Al)-based bimetals. This systematic review addresses this gap by providing a comprehensive overview of conventional and emerging techniques for Fe-based and Al-based bimetal synthesis. Specifically, this work systematically reviewed recent studies from 2014 to 2023 using the Scopus, Web of Science (WoS), and Google Scholar databases, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and was registered under INPLASY with the registration number INPLASY202540026. Articles were excluded if they were inaccessible, non-English, review articles, conference papers, book chapters, or not directly related to the synthesis of Fe- or Al-based bimetals. Additionally, a bibliometric analysis was performed to evaluate the research trends on the synthesis of Fe-based and Al-based bimetals. Based on the 122 articles analyzed, Fe-based and Al-based bimetal synthesis methods were classified into three types: (i) physical, (ii) chemical, and (iii) biological techniques. Physical methods include mechanical alloying, radiolysis, sonochemical methods, the electrical explosion of metal wires, and magnetic field-assisted laser ablation in liquid (MF-LAL). In comparison, chemical protocols covered reduction, dealloying, supported particle methods, thermogravimetric methods, seed-mediated growth, galvanic replacement, and electrochemical synthesis. Meanwhile, biological techniques utilized plant extracts, chitosan, alginate, and cellulose-based materials as reducing agents and stabilizers during bimetal synthesis. Research works on the synthesis of Fe-based and Al-based bimetals initially declined but increased in 2018, followed by a stable trend, with 50% of the total studies conducted in the last five years. China led in the number of publications (62.3%), followed by Russia, Australia, and India, while Saudi Arabia had the highest number of citations per document (95). RSC Advances was the most active journal, publishing eight papers from 2014 to 2023, while Applied Catalysis B: Environmental had the highest number of citations per document at 203. Among the three synthesis methods, chemical techniques dominated, particularly supported particles, galvanic replacement, and chemical reduction, while biological and physical methods have started gaining interest. Iron–copper (Fe/Cu), iron–aluminum (Fe/Al), and iron–nickel (Fe/Ni) were the most commonly synthesized bimetals in the last 10 years. Finally, this work was funded by DOST-PCIEERD and DOST-ERDT. Full article

The present study investigates the control strategy of a novel doubled-fed induction generator (DFIG) with a series grid-side converter (SGSC) during grid faults. The rotor-side inverter is subject to a control strategy derived from the Model Predictive Current Control (MPCC) theory, which is implemented during periods of fault occurrence; for the series grid-side converter, the positive and negative sequence component control is implemented during both steady state and fault periods to enhance system stability and performance. The proposed coordinated control strategy is implemented on a doubly fed turbine with SGSC, while taking into account different degrees of symmetric and asymmetric faults to further evaluate the efficacy of the proposed method. The results of the simulations demonstrate the efficacy of the model-predictive current control scheme applied to the rotor-side converter under conditions of asymmetric faults. This enables the suppression of a range of phenomena, including rotor overcurrent, stator overcurrent, and overvoltage, electromagnetic torque ripple, and DC bus voltage during low-voltage ride-through (LVRT), among others. The present study confirms the viability of implementing positive and negative sequences of voltage separation control in the SGSC during both grid faults and steady state. This approach is expected to minimize the switching of SGSC control strategies and thereby reduce output power fluctuations. The Rotor Side Converter (RSC) and SGSC can perform coordinated control during faults, and the proposed method is able to improve low-voltage ride-through performance compared to existing methods, thereby preventing damage to the converter under multiple fault conditions. Full article

Road–stream crossings (RSCs) are vital for the sustainability of both stream ecosystems and transportation networks, yet many are aging, undersized, or failing. Limited funding and lack of stakeholder coordination hinder effective RSC management. This study develops a multi-objective optimization (MOO) framework utilizing the non-dominated sorting genetic algorithm (NSGA-II) to maximize and balance diverse stakeholder interests (i.e., environmental and transportation agencies) while minimizing management costs. MOO was used to identify optimal RSC management scenarios at a watershed scale, using the Piscataqua–Salmon Falls watershed, New Hampshire, as a testbed. It was found that MOO consistently outperformed the currently used scoring and ranking method by the environmental and transportation agencies, improving the environmental and transportation objectives by at least 19.56% and 37.68%, respectively, across all evaluated budget limits. These improvements translate to a maximum cost saving of USD 19.87 million under a USD 50 million budget limit. Structural conditions emerged as the most influential factor, with a Pearson coefficient of 0.60. This research highlights the potential benefits of a data-driven, optimization-based approach to sustainable RSC management. Full article

Background/Objectives: HINOTORI™ is a robotic-assisted surgical platform developed in Japan. It has been applied in urologic procedures such as robot-assisted radical prostatectomy (RARP) and partial nephrectomy (RAPN). This study aimed to evaluate the clinical performance of HINOTORI™ compared with the da Vinci^® surgical system by analyzing outcomes of robot-assisted sacrocolpopexy (RSC) performed by a single skilled surgeon using a uniform surgical procedure. Methods: A total of 125 patients who underwent RSC for pelvic organ prolapse (POP) were analyzed. Surgical outcomes were compared between the HINOTORI™ (h-RSC group) and da Vinci^® (d-RSC group) platforms. Evaluated parameters included operative time, robotic console time, anterior compartment dissection time, suture time per stitch, perioperative complications, hospital stay, and POP recurrence. Results: Operative and robotic console times were significantly longer in the h-RSC group (148 vs. 139 min, p < 0.005; 109 vs. 95 min, p < 0.001). Anterior compartment dissection time showed no significant difference (p = 0.58), but suture time per stitch was longer in the h-RSC group (76 vs. 60 s, p < 0.005), possibly due to limited suture-cutting functionality, requiring manual assistance. No significant differences were observed in perioperative complications, hospital stay, and POP recurrence. Conclusions: HINOTORI™ demonstrated surgical precision and safety comparable to the da Vinci^® surgical system. It may serve as a viable alternative robotic platform, supporting broader adoption of robot-assisted surgical technologies. Full article

Well-designed rocking self-centering (RSC) columns are capable of achieving small residual displacement. However, quantitative assessments of residual displacement mechanisms in RSC columns remain understudied. The residual displacement is the product of the struggle between the self-centering (SC) capacity and the energy dissipation (ED) capacity. In this study, an SC factor and an ED parameter were defined to reflect the SC and ED capacity of the RSC column, respectively. The hysteretic behavior of an RSC pier under quasi-static load was studied. Based on the finite element model, the factorial analysis of two types of RSC piers was carried out, and the influence of eight common design parameters on the SC factor and ED parameters was discussed. Parametric analysis was performed to investigate the effect of the SC factor and the ED parameter with an increase in maximum displacement. According to the results of the parametric analysis, the effect of the SC factor and the ED parameter on the distribution of the residual displacement was statistically researched. A simplified formula was proposed to calculate the upper limit of the residual displacement. Furthermore, a set of predictive regression formulas was established to estimate the actual residual displacement. These regression formulas have an applicable condition that the ED parameter should be larger than 0.75. When the ED parameter is less than 0.75, the residual displacement is approximately zero. The hysteretic performance of an RSC pier is mainly determined by a single-factor effect, and the residual displacement distribution under a quasi-static load is mainly controlled by the SC factor and ED parameter. Full article

The irrational disposal of agricultural waste harms the interests of the main bodies of the related supply chain while seriously jeopardizing the environment. To a certain extent, the reverse supply chain (RSC) of agricultural waste can provide more high-quality resources for agricultural production and promote the green development of agricultural production. Therefore, RSC optimization is of great significance to the sustainable development of agriculture. We constructed an evolutionary game model of agricultural waste recyclers and reprocessing enterprises for agricultural waste. The stability of mixed strategies was analyzed using a Jacobi matrix, and evolutionary paths under varying parameter ranges were simulated using MATLAB. The simulation results show that in the early stage of RSC optimization, government subsidies to reprocessing enterprises and increased subsidies for agricultural waste recyclers are conducive to a more stable agricultural waste reverse-recycling market. When the agricultural waste reverse-recycling market reaches a certain scale, the government should gradually reduce subsidies, effectively preventing enterprises from being overly reliant on them. This study not only offers a decision-making foundation for agricultural waste recyclers and agricultural waste reprocessing enterprises to make optimal strategic choices but also serves as a reference for the government in formulating appropriate policies. Full article