Search Results (1,286)

To maintain power system stability and supply quality when integrating doubly fed induction generator (DFIG)-based wind energy conversion systems (DFIG-WECSs), regulators regularly update grid codes specifying low voltage ride-through (LVRT) requirements. This paper presents a systematic literature review (SLR) on the use of STATCOMs to enhance LVRT capability in DFIG-WECSs. Objectives included a structured literature search, bibliographic analysis, thematic synthesis, trend identification, and proposing future research directions. A PRISMA-based methodology guided the review, utilising PRISMA 2020 for Abstracts in the development of the abstract. The final search was conducted on Scopus (31 March 2025). Eligible studies were primary research in English (2009–2014) where STATCOM was central to LVRT enhancement; exclusions included non-English studies, duplicates, reviews, and studies without a STATCOM focus. Quality was assessed using an adapted Critical Appraisal Skills Programme (CASP) tool. No automation or machine learning tools were used. Thirty-eight studies met the criteria and were synthesised under four themes: operational contexts, STATCOM-based schemes, control strategies, and optimisation techniques. Unlike prior reviews, this study critically evaluates merits, limitations, and practical challenges. Trend analysis shows evolution from hardware-based fault survival strategies to advanced optimisation and coordinated control schemes, emphasising holistic grid stability and renewable integration. Identified gaps include cyber-physical security, techno-economic assessments, and multi-objective optimisation. Actionable research directions are proposed. By combining technical evaluation with systematic trend analysis, this review clarifies the state of STATCOM-assisted LVRT strategies and outlines pathways for future innovation in DFIG-WECS integration. Full article

This study developed a two-step conversion strategy for the efficient conversion of bamboo waste into 5-hydroxymethylfurfural (HMF). First, ultrasonic-assisted formic acid pretreatment was used at 80 °C for 3 h, removing approximately 83.7% of hemicellulose and 76.5% of lignin from the biomass, with a cellulose recovery of 93.5%. The ultrasonic step significantly enhanced the chemical action of formic acid through cavitation, allowing formic acid to penetrate deeper into the biomass, thereby more effectively removing hemicellulose and lignin. Subsequently, glucose was obtained through an enzymatic hydrolysis. In the second step of HMF preparation, citric acid in the hydrolysate was combined with ChCl to form an acidic deep eutectic solvent (DES), and metal chlorides were added as Lewis acid catalysts. Experiments results showed that when the ChCl–citric acid ratio was 2:1, and the Ca²⁺ concentration was 100 mM, an HMF yield of 51.9% was obtained at 220 °C for 1.5 h. This study provides an efficient, mild, and environmentally friendly method for the high-value valorization of waste bamboo. Full article

Spent coffee grounds (SCG) are an abundant, carbon-rich residue that can be valorized through thermochemical conversion into biochar. Conventional CO₂ activation is typically performed in a two-step process, which is time- and energy-consuming. This study aims to evaluate whether a one-step CO₂-assisted pyrolysis can produce biochar with comparable or enhanced structural and textural properties while simplifying the process. We compare a two-step pyrolysis process followed by CO₂ activation with a one-step CO₂-assisted route for producing biochar from SCG. CO₂ treatment markedly increases surface area (from 9.8 m²∙g⁻¹ to 550.6–671.0 m²∙g⁻¹) and pore volume. FTIR and Boehm titration indicate depletion of oxygenated surface groups, while N₂ adsorption–desorption analyses and SEM reveal a more uniform micro/mesoporous texture for the one-step sample. Although fixed carbon decreases due to gasification, the one-step route delivers superior textural properties in a single thermal stage, reducing energy demand. These results highlight one-step CO₂-assisted pyrolysis as an efficient, scalable option for producing high-porosity biochar from coffee waste. Full article

Objectives: To compare the therapeutic efficacy and safety of balloon-assisted transarterial chemoembolization (B-TACE) versus conventional TACE (C-TACE) in hepatocellular carcinoma (HCC) and to evaluate the potential predictive value of intraoperative balloon-occluded arterial stump pressure (Boasp). Methods: In this prospective, single-centre, randomized controlled study, 60 patients with hepatocellular carcinoma were allocated to either the B-TACE group (n = 30) or the C-TACE group (n = 30). One patient in the B-TACE group was lost to follow-up after allocation. The primary analyses were conducted according to the intention-to-treat (ITT) principle, including all randomized patients, with conservative handling of missing data. Sensitivity analyses were performed to assess the robustness of the results. Tumor response and survival outcomes were evaluated using the modified Response Evaluation Criteria in Solid Tumors (mRECIST) and Cox proportional hazards regression models. Intraoperative balloon-occluded arterial stump pressure (BOASP) was measured as an exploratory parameter to quantify embolization adequacy. Adverse events (AEs) were systematically assessed and graded according to the Common Terminology Criteria for Adverse Events (CTCAE), version 5.0. Results: TACE achieved a higher 3-month ORR (63.3% vs. 10.0%, p < 0.001) and 6-month disease control rates (80.0% vs. 36.7%, p < 0.001), with PFS (HR = 0.30, 95% CI 0.148–0.608) and procedures within 6 months (1 vs. 3, p < 0.001). The 6-month surgical conversion rate was higher (34.5% vs. 6.7%, p = 0.009). Changes in Boasp correlated with efficacy (AUC = 0.825, p = 0.0398). Severe infections were lower in B-TACE (17.2% vs. 76.7%, p < 0.001). Conclusions: B-TACE offers superior efficacy, survival, and surgical conversion versus C-TACE with favorable safety. Boasp provides a quantitative biomarker for predicting treatment response. Full article

Objectives: Robotic-Assisted Thoracic Surgery (RATS) has emerged as a viable alternative to traditional median sternotomy for patients with anterior mediastinal tumors suspected of having thymoma or those with Myasthenia Gravis (MG). While median sternotomy remains a widely accepted standard approach, RATS has gained popularity due to its potential benefits. Methods: We retrospectively reviewed our 5 years’ experience of performing 111 surgeries for patients with anterior mediastinal tumors and patients with MG suspected of having thymoma. We performed multivariate regression models to assess the association between main demographic and clinical variables and two primary outcomes: overall complications and hospital stay. Results: Out of 111 patients, 54 were men (48.6%) and 57 were women (51.4%). The majority of surgeries (n = 93) were performed by RATS (83.8%), while the remainder were performed by either median sternotomy (n = 15, 13.5%) or by other approaches (n = 3, 2.7%). Sixty-five patients were diagnosed with thymoma (58.6%), with 96.9% R0 resection. Sixty-five patients underwent left-sided surgery (58.6%), and thirty-one underwent right-sided surgery (27.9%). The conversion rate was 2.5%. The rate of postoperative complications was 8.1 without perioperative mortality. The median hospital stay was 4.62 days, but it was significantly shorter in the RATS compared to the median sternotomy group (mean 3.64 vs. 10.67 days, p = 0.040). Conclusions: Our results suggest that RATS for patients with anterior mediastinal tumors suspected of having thymoma or for those with MG is safe and technically feasible and may be the preferred surgical approach for selected patients, whereas traditional median sternotomy remains the preferred choice for more locally advanced tumors. Full article

Electrochemical CO₂ reduction (CO₂RR) is a promising route to transform a major greenhouse gas into value-added fuels and chemicals. However, its deployment is still hindered by the sluggish activation of CO₂, poor selectivity toward multielectron products, and competition with the hydrogen evolution reaction (HER). Single-atom catalysts (SACs) have emerged as powerful materials to address these challenges because they combine maximal metal utilization with well-defined coordination environments whose electronic structure can be precisely tuned through metal–support interactions. This minireview summarizes current understanding of how structural, electronic, and chemical features of SAC supports (e.g., porosity, heteroatom doping, vacancies, and surface functionalization) govern the adsorption and conversion of key CO₂RR intermediates and thus control product distributions from CO to CH₄, CH₃OH and C₂⁺ species. Particular emphasis is placed on selectivity descriptors (e.g., coordination number, d-band position, binding energies of *COOH and *OCHO) and on rational design strategies that exploit curvature, microenvironment engineering, and electronic metal–support interactions to direct the reaction along desired pathways. Representative SAC systems based primarily on N-doped carbons, complemented by selected examples on oxides and MXenes are discussed in terms of Faradaic efficiency (FE), current density and operational stability under practically relevant conditions. Finally, the review highlights remaining bottlenecks and outlines future directions, including operando spectroscopy and data-driven analysis of dynamic single-site ensembles, machine-learning-assisted DFT screening, scalable mechanochemical synthesis, and integration of SACs into industrially viable electrolyzers for carbon-neutral chemical production. Full article

The increasing global demand for clean hydrogen necessitates production methods that minimize greenhouse gas emissions while being scalable and economically viable. Hydrogen has a very high gravimetric energy density of about 142 MJ/kg, which makes it a very promising energy carrier for many uses, such as transportation, industrial processes, and fuel cells. Methane pyrolysis has emerged as an attractive low-carbon alternative, decomposing methane (CH₄) into hydrogen and solid carbon while circumventing direct CO₂ emissions. Still, the process is very endothermic and has always depended on fossil-fuel heat sources, which limits its ability to run without releasing any carbon. This review examines the integration of geothermal energy and methane pyrolysis as a sustainable heat source, with a focus on Enhanced Geothermal Systems (EGS) and Closed-Loop Geothermal (CLG) technologies. Geothermal heat is a stable, carbon-free source of heat that can be used to preheat methane and start reactions. This makes energy use more efficient and lowers operating costs. Also, using flared natural gas from remote oil and gas fields can turn methane that would otherwise be thrown away into useful hydrogen and solid carbon. This review brings together the most recent progress in pyrolysis reactors, catalysts, carbon management, geothermal–thermochemical coupling, and techno-economic feasibility. The conversation centers on major problems and future research paths, with a focus on the potential of geothermal-assisted methane pyrolysis as a viable way to make hydrogen without adding to the carbon footprint. Full article

This paper presents the design, implementation and evaluation of an agentic virtual assistant (VA) for a medical clinic, combining large language models (LLMs) with retrieval-augmented generation (RAG) technology and multi-agent artificial intelligence (AI) frameworks to enhance reliability, clinical accuracy and explainability. The assistant has multiple functionalities and is built around an orchestrator architecture in which a central agent dynamically routes user queries to specialized tools for retrieval-augmented question answering (Q&A), document interpretation and appointment scheduling. The implementation combines LangChain and LangGraph with interactive visualizations to track reasoning steps, prompts using Gemini 2.5 Flash defines tool usage and strict formatting rules, maintaining reliability and mitigating hallucinations. Prompt engineering has an important role in the implementation and thus, it is designed to assist the patient in the human–computer interaction. Evaluation through qualitative and quantitative metrics, including ROUGE, BLEU, LLM-as-a-judge and sentiment analysis, confirmed that the multi-agent architecture enhances interpretability, accuracy and context-aware performance. Evaluation shows that the multi-agent architecture improves reliability, interpretability and alignment with medical requirements, supporting diverse clinical tasks. Furthermore, the evaluation shows that Gemini 2.5 Flash combined with clinic-specific RAG significantly improves response quality, grounding and coherence compared with earlier models. SBERT analyses confirm strong semantic alignment across configurations, while LLM-as-a-judge scores highlight the superior relevance and completeness of the 2.5 RAG setup. Although some limitations remain, the updated system provides a more reliable and context-aware solution for clinical question answering. Full article

Advanced ceramics are known for their lightweight, high-temperature resistance, corrosion resistance, and biocompatibility. They are crucial in energy conversion, environmental protection, and aerospace fields. This review highlights the recent advancements in ceramic matrix composites, high-entropy ceramics, and polymer-derived ceramics, alongside various fabrication techniques such as three-dimensional printing, advanced sintering, and electric-field-assisted joining. Beyond the fabrication process, we emphasize how different processing methods impact microstructure, transport properties, and performance metrics relevant to catalysis. Additive manufacturing routes, such as direct ink writing, digital light processing, and binder jetting, are discussed and normalized based on factors such as relative density, grain size, pore architecture, and shrinkage. Cold and flash sintering methods are also examined, focusing on grain-boundary chemistry, dopant compatibility, and scalability for catalyst supports. Additionally, polymer-derived ceramics (SiOC, SiCN, SiBCN) are reviewed in terms of their catalytic performance in hydrogen evolution reaction, oxygen evolution reaction, oxygen reduction reaction, and CO₂ reduction reaction. CeO₂-ZrO₂ composites are particularly highlighted for their use in environmental catalysis and high-temperature gas sensing. Furthermore, insights on the future industrialization, cross-disciplinary integration, and performance improvements in catalytic applications are provided. Full article

Efficient conversion of biomass-based platform molecules into high-value derivatives is recognized as one formidable challenge in biomass upgrading. In this work, a one-pot deep eutectic solvents-assisted solvothermal method was developed for the modification of the commercial Pt/C catalysts by introducing a secondary metal (M = Sn, Bi, Ge, Sb, Pb). The structural and electronic properties of the catalysts were precisely tuned. Among the screened metals, the addition of Sn yielded the most significant improvement in catalytic activity. The optimized PtSn_0.5/C-140 catalyst achieved superior furfural (FAL) conversion and furfuryl alcohol (FOL) selectivity under mild conditions (20 °C, 2 MPa H₂). Comprehensive characterizations, including XRD, HRTEM, XPS, and H₂-TPD, confirmed the formation of Pt-Sn solid-solution phase. Furthermore, Characterization and reaction results revealed that the electronic and geometric effects induced by Sn modulated Pt active sites, significantly enhancing the adsorption of the active H species. Additionally, the SnO_x species adjacent to the Pt-Sn sites served as hydrogen spillover acceptors, further accelerating the hydrogenation process. The synergy between the Pt-Sn solid-solution phase and SnO_x species is identified as the origin of the superior performance at room temperature. These findings provide a new strategy for the design of high-performance biomass conversion catalysts by upgrading commercial noble metal catalysts. Full article

Background/Objectives: Evaluating the feasibility of randomized controlled trials (RCTs) represents a critical next step for advancing human–animal interaction (HAI) science and rigorously exploring the role of animal-assisted interventions (AAIs) in psychiatric acute care. This study presents strategies for conducting a pilot RCT comparing an animal-assisted intervention involving dogs (AAI) with an active conversational control (CC), which incorporated conversation with a human volunteer, and treatment as usual (TU) for improving mental health outcomes in psychiatrically hospitalized adults. Methods: We recruited participants from an acute-care psychiatric unit at an academic medical center. AAI and CC were delivered by volunteer handlers with and without their registered therapy dogs. Feasibility data included number of recruitment contacts, recruitment rate, and reasons for non-enrollment. We describe recruitment challenges encountered and mitigating strategies for successful study completion. Results: Recruitment occurred over 23 months with a goal of 60 participants participating in at least one intervention day. A total of 264 patients were referred to the study and 72 enrolled. The additional 12 people were recruited to replace participants who did not complete any intervention days and did not provide any intervention data. Study recruitment goals were met with a recruitment rate of 27.30%. Conclusions: Research to improve the lives of patients in acute psychiatric care is a vital public health goal, yet RCTs are difficult to conduct in acute care settings. Studies like this strengthen HAI and psychiatric science by providing a roadmap for implementing successful AAI RCT designs. Full article

Burnout results from chronic workplace stress and is most effectively addressed through workplace interventions. Successful implementation of interventions may, however, be constrained by factors within the work environment. This study aimed to evaluate a new tool, the Veterinary Nurse Burnout Prevention Survey (VNBPS). The 35-item, cross-sectional mixed methods survey aimed to identify the presence of burnout risk factors for veterinary nurses (VNs), and support selection of tailored interventions within the clinic. The VNBPS was conducted within VN teams (N = 67) across six Australian veterinary clinics between August and September 2025. After delivery and analysis of the survey, a summary of results and tailored recommendations was provided to each clinic. A subsequent evaluation questionnaire measured perceived ease of participation, accuracy of findings, and practicality of recommendations. The majority of the 17 respondents who completed the evaluation questionnaire (71%, n = 10) found the survey very easy to complete, and the findings to be accurate (79%, n = 11), or very accurate (21%, n = 3). Recommended interventions were perceived to be practical (50%, n = 7) or very practical (29%, n = 4). Internal reliability of the VNBPS was good. Participants reported that the survey held additional value in initiating conversations about burnout. This confirms the VNBPS as a useful tool to assist veterinary workplaces in the prevention of VN burnout and provide practical support for leaders to improve the wellbeing and professional sustainability of VN teams. Full article

Existing vehicle-mounted satellite terminals primarily rely on mechanical or purely analog electronically steered antennas. They lack protocol-level relay capability and usually provide only short-range hotspot connectivity. These limitations make it difficult for such systems to deliver stable, high-throughput satellite access for personal mobile devices in dynamic vehicular environments, especially in remote regions without terrestrial networks. This paper proposes an intelligent vehicle repeater for satellite networks (IVRSN) that builds a dedicated satellite–vehicle–device relay architecture. It enables reliable broadband connectivity for conventional mobile terminals without requiring specialized satellite hardware. The IVRSN consists of three key technical components. Firstly, a dual-mode relay coverage mechanism is designed to support energy-efficient in-vehicle access and extended out-of-vehicle coverage. Secondly, a DoA-assisted, attitude-compensated hybrid beamforming scheme is developed. It combines subspace-based direction estimation with inertial sensor measurements to maintain high-precision satellite pointing under vehicle dynamics. Finally, a bidirectional protocol conversion module is introduced to ensure compatibility between ground wireless protocols and satellite link-layer formats with integrity-checked data forwarding. Compared to existing solutions, the proposed IVRSN provides higher stability and broader device compatibility, making it a feasible solution for high-speed, high-quality communications in remote or disaster regions. Full article

In situ preparation routes have become central to advancing lead sulfide (PbS) quantum dots (QDs) for solar-energy conversion, owing to their ability to create strongly coupled QD/oxide interfaces that are difficult to achieve with ex situ colloidal methods, along with their simplicity and potential for low-cost, scalable processing. This review systematically examines the fundamental mechanisms, processing levers, and device implications of the dominant in situ approaches successive ionic layer adsorption and reaction (SILAR), voltage-assisted SILAR (V-SILAR), and chemical bath deposition (CBD). These methods enable conformal QD nucleation within mesoporous scaffolds, improved electronic coupling, and scalable low-temperature fabrication, forming the materials foundation for high-performance PbS-based architectures. We further discuss how these in situ strategies translate into enhanced solar-energy applications, including quantum-dot-sensitized solar cells (QDSSCs) and photoelectrochemical (PEC) hydrogen production, highlighting recent advances in interfacial passivation, scaffold optimization, and bias-assisted growth that collectively suppress recombination and boost photocurrent utilization. Representative device metrics reported in recent studies indicate that in-situ-grown PbS quantum dots can deliver photocurrent densities on the order of ~5 mA cm⁻² at applied potentials around 1.23 V versus RHE in photoelectrochemical systems, while PbS-based quantum-dot-sensitized solar cells typically achieve power conversion efficiencies in the range of ~4–10%, depending on interface engineering and device architecture. These performances are commonly associated with conformal PbS loading within mesoporous scaffolds and quantum-dot sizes in the few-nanometer regime, underscoring the critical role of morphology and interfacial control in charge transport and recombination. Recent studies indicate that performance improvements in PbS-based solar-energy devices are primarily governed by interfacial charge-transfer kinetics and recombination suppression rather than QD loading alone, with hybrid heterostructures and inorganic passivation layers playing a key role in modifying band offsets and surface trap densities at the PbS/oxide interface. Remaining challenges are associated with defect-mediated recombination, transport limitations in densely loaded porous scaffolds, and long-term chemical stability, which must be addressed to enable scalable and durable PbS-based photovoltaic and photoelectrochemical technologies. Full article

This study investigates the accumulation potential of Brassica napus L. and Zea mays L. cultivated on soils contaminated with Zn, Cd, Cu and Pb, using HEDTA—Hydroxyethyl Ethylenediamine Triacetic Acid—to enhance metal mobility. The research addresses a gap in the literature regarding the dual-purpose use of energy crops for assisted phytoextraction and bioenergy recovery. Two pot experiments were conducted on soils of different textures, with HEDTA applied at 2.5 and 5 mmol·kg⁻¹. Metal concentrations in soil and plant tissues were measured, and indices such as the geoaccumulation index (Igeo), bioconcentration factors (BCF), translocation factor (TF), metal tolerance index (MTI), crop growth rate (CGR) and higher heating value (HHV) were calculated. Results showed that HEDTA significantly increased Cd and Zn mobility, leading to higher accumulation in rapeseed shoots. Maize demonstrated phytostabilization by retaining metals in roots. Rapeseed biomass exhibited a higher HHV (up to 20.6 MJ·kg⁻¹) and greater carbon and hydrogen content, indicating suitability for thermochemical conversion. Maize, with lower ash content, showed potential for bioethanol production. The findings support the integration of chelate-assisted phytoextraction with energy recovery from biomass. Full article