Search Results (610)

Marine biofouling is a major global concern affecting the marine industry, the environment, and public health. The accumulation of organisms on submerged surfaces causes significant economic losses, including increased fuel consumption, higher pollutant emissions, and accelerated corrosion. Antifouling (AF) coatings with biocides are widely used to prevent this problem. However, many conventional biocides have been banned due to toxicity, creating an urgent need for environmentally friendly alternatives. In previous studies, we synthesized a gallic acid derivative and three flavonoids that showed AF activity against the settlement of mussel larvae (Mytilus galloprovincialis) together with low ecotoxicity. In the present work, to further assess their potential in marine coatings and exploit the advantages of nanocarriers in protecting and prolonging bioactive effects, these compounds were loaded into halloysite nanotubes (HNTs) and incorporated into epoxy coatings. Coatings containing the same AF compounds in free form were also prepared for comparison. HNTs were characterized by scanning electron microscopy (SEM), and compound loading was quantified by thermogravimetric (TG) analysis. The resulting composites were analyzed by SEM and dynamic water contact angle measurements. Laboratory bioassays with M. galloprovincialis larvae showed that coatings containing HNT-loaded synthetic compounds generally reduced larval settlement more effectively than the corresponding coatings containing the same compounds directly dispersed in the epoxy matrix, with values below 20% after both 15 and 40 h of exposure for the best-performing formulation. These findings highlight the novelty of the proposed HNT-based delivery strategy for nature-inspired synthetic antifoulants and support its potential for the development of effective and environmentally safer AF coatings. Full article

To reduce the impact of aviation on the environment, a multitude of concepts must be evaluated to enable subsequent targeted developments. The reduction of on-board energy requirements through the aero-propulsive coupling of a box-wing configuration can represent one possible approach. It enables a decreased environmental impact by cutting the energy required and—in the configuration under consideration—by using hydrogen fuel cells as power generators. To fully exploit the advantages of such a concept, different propulsion system architectures were analyzed. Decision criteria were developed to select the most sensible powertrain architecture for the box-wing regional aircraft considering component and aircraft-level effects in a two-phased approach; following a qualitative preselection, a multi-criteria decision analysis was employed. Fuselage, fairing and nacelle-bound architecture options for the 70-passenger aircraft with a projection of its powertrain characteristics into the year 2045 are shown and compared. The placement of propulsion system components as well as their characteristics play a major role in the downselection of propulsion architecture options, especially considering the requirements placed by the liquid hydrogen energy storage. Due to low aerodynamic interference with the specific aero-propulsive arrangement, its high safety characteristics, synergistic potential with other systems, and not least, ease of integration, a compact propulsion system placement forward of the front hydrogen tank is considered most beneficial on aircraft level. Full article

As the key technology of space exploration, space power has been a major area of international research focus. A lot of research work has been carried out around the world for the space nuclear reactor using the heat pipe, liquid metal and gas cooling methods. With the development of molten salt reactor in the Generation IV reactor system, molten salt dissolving fissile material and acting as a coolant at the same time has become a new cooling scheme, which provides new ideas for the design of space nuclear reactors. In this study, a novel reactor, the liquid-solid dual-fuel space nuclear reactor (LSSNR) was preliminarily proposed, combining the molten salt fuel and cross-shaped spiral solid fuel to achieve the design goals of 30-year lifetime and an active core weight of less than 200 kg. Monte Carlo neutron transport code OpenMC based on ENDF/B-VII.1 library was employed for neutronics design in the aspect of fuel type, cladding material, reflector material and the spectral shift absorber. Then, the thickness of the control drum absorber was optimized to meet the requirement of the sufficient shutdown margin, lower solid fuel enrichment, and 30-effective-full power-years (EFPY) operation lifetime. Finally, UC solid fuel with U-235 enrichment of 80.98 wt.% and B₄C thickness of 0.75 cm were adopted in LSSNR, and BeO was adopted as the reflector and the matrix material of the control drum. A spectral shift absorber Gd₂O₃ was used to avoid the subcritical LSSNR returning to criticality in a launch accident. The k_eff with the control drum in the innermost position is 0.954949, and the k_eff reaches 1.00592 after 30 EFPY of operation. The total mass of the active core is 158.11 kg. In addition, the thermal-hydraulic feasibility of LSSNR using cross-shaped spiral fuel was analyzed based on a 4/61 reactor core model. The structure of cross-shaped spiral fuel achieves enhanced heat transfer by generating turbulence, which leads to a uniform temperature distribution of the coolant flow field and reduces local temperature peaks. Based on the LSSNR scheme, some neutronic characteristics were analyzed. Results demonstrate that the LSSNR has strongly negative reactivity coefficients due to the thermal expansion of liquid fuel, and the fission gas-induced pressure meets safety requirements. One hundred years after the end of core life, the total radioactivity of reactor core is reduced by 99% and is 7.1305 Ci. Full article

Globally, the transport sector accounts for almost a quarter of CO₂ emissions from fuel combustion and generates large amounts of pollutants, placing significant pressure on the environment and human health. By 2050, the European Green Deal requires a 90% reduction in transport-related emissions, making sustainability necessary across all modes of transport. Based on the relevant literature, this study examines the role and potential of railways in decarbonising the EU transport sector. Railway is highly efficient, consuming just 1.9% of transport sector energy while handling 16.9% of freight and 5.1% of passenger transport in the EU, yet is responsible for only 0.4% of total emissions. According to studies, greenhouse gas emissions can be reduced by improving energy efficiency, using low-carbon or renewable energy, and expanding train electrification. The greatest potential for decarbonisation lies in a modal shift to rail. However, this requires significant infrastructure investment: raising line speeds to at least 160 km/h, expanding networks, building terminals, digitalisation, and alignment with TEN-T standards. Although the EU supports the modal shift with funding programmes, the transition is not progressing as expected—the share of road freight transport increased from 74% in 2013 to 78% in 2023. Stronger investment is needed in Member States’ national policies for the development and modernisation of railways. The authors developed a Path Evaluation Matrix (PEM), a quantitative decision framework integrating the fields of energy, transport, politics, and economics. The PEM results indicate that BEMU (battery electric multiple units) is optimal for 68% of secondary lines in south-eastern Europe. Full article

Radiotherapy is essential for treating head and neck cancer but frequently leads to radiation-induced fibrosis (RIF) in salivary glands (SGs). RIF develops through a cascade of radiation-triggered events, including DNA damage, excessive oxidative stress, and epithelial cell death. Persistent injury can cause cells to become senescent and release inflammatory signals, fueling chronic inflammation. These processes activate pathways, particularly TGF-β/SMAD, resulting in fibroblast activation, myofibroblast differentiation, and extracellular matrix accumulation. Potential treatments include drugs, mesenchymal stem/stromal cell (MSC) therapy, and gene-transfer approaches. In which, MSC therapy is particularly promising as MSCs can migrate to injured tissue and support epithelial regeneration. Yet progress is limited by the difficulty of expanding human acinar cells (ACs) in vitro. To address this gap, tunable alginate–gelatin–hyaluronic acid (AGHA) bioink hydrogels have emerged as a suitable system as gelatin provides adhesion sites for AC attachment and 3D organoid formation, alginate offers tunable mechanical support through ionic crosslinking, and hyaluronic acid contributes essential cues for cell adhesion, migration, and morphogenesis. The aim of this review is to synthesize current understanding of the mechanisms driving RIF, evaluate available therapeutic strategies, and highlight the role of AGHA in generating engineered SG constructs to test MSC therapies for RIF. Full article

The most impactful factors for the cost of fleet management are maintenance expenses and fuel consumption. Traditional ways of monitoring fleet performance fail to connect raw operational data with driving habits. The current study addresses this challenge by developing an architecture of frameworks, consisting of unsupervised and supervised machine learning algorithms, statistical testing, simulation and survival analysis to discover insights that lead to key behavioral predictors. The nucleus of this complex architecture is the decision-making grid (DMG), a two-dimensional matrix that groups vehicles based on their frequency of entering the service and the cost of their repairs. It is the first integration of DMG with ML for prescriptive fleet management. The objective of the study is twofold: firstly, to build a system that classifies vehicles according to their risk profile, and secondly, to offer clear directions for changing driver patterns that most affect vehicle costs or for keeping good practices. The framework proposed by this study not only drives the optimization of operational efficiency but also contributes to a methodology that links driver profiles to costs, offering a scalable methodology for similar business contexts. Full article

The increasing demand for energy and the continued reliance on fossil fuels pose important environmental and social challenges, particularly for rural and isolated communities in developing countries that lack reliable access to the grid. Gravitational water vortex turbines (GWVT) are a run-of-river technology for low-head and moderate-flow sites that can provide decentralized electricity without the construction of large reservoirs. The expected environmental impacts are lower; nevertheless, to increase acceptance by the community, there is a necessity to identify and analyze the potential environmental impacts of GWVT in all its life-cycle phases (installation, operation, maintenance, and dismantling). The present study applies the Conesa cause–effect matrix to identify, classify, and analyze the potential environmental impacts associated with GWVT phases. Key identified impacts include removal of vegetation coverage and site disturbance (−32), sediment dynamics alterations (−39), formation of a depleted stretch (−45), accidental releases of hazardous maintenance products (−42), and remobilization of retained sediments (−46). These impacts can produce habitat alteration and fragmentation and loss of ecological connectivity. The relevant significance of energy generation that can have multiple benefits in the local communities was also identified. Primary mitigation measures include the incorporation of environmental flows in the design, sediment management, and strict protocols for hazardous materials. The findings underscore the necessity to conduct site-specific baseline surveys to preserve environmental, socio-economic, and cultural conditions in the local ecosystem and communities. Full article

Renewable hydrogen purification is a critical yet often underemphasised step in enabling its use as a clean energy carrier. Hydrogen produced from biomass-based thermochemical and biological routes typically contains CO₂, CO, CH₄, H₂S, and other impurities that must be removed to meet stringent requirements for fuel cell, industrial, and grid-injection applications. This review provides a critical and up-to-date assessment of renewable hydrogen purification technologies, focusing on their suitability for variable and impurity-rich renewable hydrogen streams. Established benchmark technologies, including pressure swing adsorption and cryogenic separation, are described, with emphasis on their operating principles, material innovations, and process integration strategies. Recent advancements in inorganic, polymeric, and mixed-matrix membranes are highlighted, with particular focus on how advanced porous materials enhance selectivity, permeability, and flexibility. Additionally, a comparative techno-economic assessment is presented, evaluating each purification method based on technology readiness level, capital and maintenance costs, energy efficiency, and operational lifespan. By incorporating recent research trends, this approach facilitates the selection and design of purification systems that are not only efficient and scalable but also cost-effective, tailored to both decentralised and centralised renewable hydrogen production. Full article

Previous research indicates that WC-12Co contents above 60 wt.% in feedstock powders for cermet coatings impair adhesion and wear resistance. This study characterizes NiCrFeSiAlBC coatings—unreinforced or reinforced with 65 wt.% or 85 wt.% WC-12Co—applied via high-velocity oxy-fuel (HVOF) spraying onto stainless steel substrates under controlled parameters. It quantifies the influence of high carbide volume fractions within the NiCrFeSiAlBC matrix on microstructure and tribomechanical performance. Microstructural analysis revealed uniformly distributed cermet layers featuring dissolved reinforcements and WC hard phase formation, with minimal W₂C crystallization. Elevated WC-12Co incorporation promoted densification and reduced porosity. Vickers microhardness tests (HV 0.3) demonstrated increased hardness upon WC-12Co addition, attributable to finer particle sizes, lower porosity, and the presence of WC phases alongside crystallographic refinements. Under dry reciprocating sliding conditions, friction coefficients and wear volumes decreased markedly. Consequently, the coating with 85 wt.% WC exhibited the best mechanical and tribological properties. Full article

The commercialization of proton-exchange-membrane fuel cells is constrained by the limitations of perfluorosulfonic acid membranes like Nafion, which suffer from high methanol crossover, humidity-dependent conductivity, high cost, and poor environmental sustainability. This review presents a comprehensive analysis of aquaporin-inspired chitosan/cellulose (AQP-CS) composite membranes as a transformative, bio-inspired alternative. The central design paradigm integrates a sustainable chitosan/cellulose matrix—which offers inherent mechanical stability, tunable proton conduction, and excellent fuel barrier properties—with biomimetic water channels engineered for selective hydration transport. This synergistic architecture aims to fundamentally decouple water management from proton conduction, directly addressing the core performance flaw of conventional membranes. The review is structured to explicitly trace the logical pathway from the foundational material properties of chitosan and cellulose to the functional requirements for integrating synthetic aquaporin-mimetic components. Experimental evidence from advanced chitosan composites, demonstrating proton conductivities up to 0.131 S cm⁻¹ alongside drastically reduced methanol permeability, validates the potential of this approach. Consequently, AQP-CS composites establish a novel framework for developing next-generation fuel cell membranes that combine high performance with ecological design. However, key challenges in the stable integration of biomimetic channels, long-term operational durability, and scalable manufacturing must be resolved to enable practical deployment and mark a significant leap toward sustainable energy conversion technologies. Full article

Cellular senescence has been traditionally viewed as a tumor-suppressive program that halts its proliferation in response to oncogenic stress or DNA damage. However, recent studies have highlighted a paradoxical role for senescence in glioblastoma (GBM), IDH-wildtype, the most aggressive primary brain tumor in adults. Accumulating evidence indicates that senescence represents a “frequent and durable” cell fate in GBM, particularly following standard therapies such as temozolomide and radiotherapy. Senescent cells frequently persist after temozolomide or radiotherapy and acquire a senescence-associated secretory phenotype (SASP) composed of inflammatory cytokines, growth factors and matrix-remodeling enzymes. These factors not only promote tumor cell survival with stemness-induction but also reshape the pro-tumorigenic microenvironment with metabolic rewiring and immune evasion. Notably, senescence also arises in non-malignant cells—including astrocytes, endothelial cells, microglia, and infiltrating immune cells—creating a multicellular senescent niche that fuels recurrence. Here, we describe a recent advance in our understanding of senescence and SASP in the pathobiology of GBM. We further focus on a state-of-the-art, challenging exploration of the idea that single-cell and spatial profiling, capable of identifying senescence- and SASP-associated morphologic and heterogeneous states, will further refine patient selection and therapeutic timing. By reframing senescence as a modifiable determinant of GBM evolution, this review underscores its emerging significance as both a cancer hallmark and a therapeutic vulnerability. Full article

The transition to green hydrogen is critical for achieving sustainable energy systems and climate goals. This study presents MODERHydrogen-H₂, a comprehensive framework for assessing solar- and wind-based green hydrogen production, fossil fuel substitution, and greenhouse gas (GHG) reduction. The method integrates Geographic Information Systems (GIS) to optimize renewable energy resource allocation while adhering to sustainability criteria. Applied to four solar sites (2000 MW) in Colombia’s Magdalena–Cauca Basin and three wind projects (1700 MW) in the Caribbean Basin, the model estimates an annual production of 211,074 tons of green hydrogen by 2030. This output could displace 37,221 terajoules of fossil fuels, contributing 2.5% to the national energy matrix and reducing CO₂ emissions by 10.09 million tons. MODERHydrogen-H₂ demonstrates scalability and adaptability, offering a decision-support tool for global energy transition strategies. Its implementation supports affordable, reliable, and low-carbon energy systems, aligning with Sustainable Development Goals (SDGs) targets. The model offers a single platform from which to simulate renewable energy potential in a sustainable manner within a given geographical area, develop scenarios for modifying the energy matrix of a country or region, simulate rational and efficient water supply and demand for energy uses, including aspects of climate change, calculate green hydrogen production in a sustainable manner, and finally calculate greenhouse gas emissions. Full article

Ceramic Matrix Composites (CMCs) have emerged as a structural material alternative to nickel superalloys for high-pressure turbines (HPT) components operating at high temperature, like shrouds. Despite the outstanding thermal stability of the CMCs, limited cooling is still necessary due to the extreme thermal operating conditions necessary to maximize engine performance and minimize fuel consumption. The design of CMC components, indeed, must consider a maximum service temperature that should not be exceeded to avoid damage and accelerated oxidation. The cooling, on the other hand, may induce the formation of thermal gradients and thermal stresses. In this work, different design options for the cooling system are investigated to minimize the thermal stresses of an HPT shroud-like geometry subjected to maximum temperature constraints on the material. Cooling is obtained via colder air jet streams (air taken from the compressor), whose impact position (the surface where the cold air impacts the component) has a different effect on the temperature field and on the induced stress field. Besides stress evaluation with different cooling systems, an ONERA damage model is investigated at a key location to potentially take into account stress components acting simultaneously and potential stiffness degradation of the CMC. Finally, the design evaluation of potential discrete crack propagation is discussed. A standard cohesive elements approach has been compared with a brittle element death approach. The results showed that the cohesive element approach resulted in shorter crack propagation, underestimating the actual crack behavior due to the embedded stiffness degradation method, while the element death returned encouraging results as a quicker, less complex, but still accurate design evaluation. Full article

MXenes, a family of two-dimensional transition metal carbides and nitrides, exhibit exceptional electrical conductivity, tunable surface chemistry, and strong broadband light absorption. However, their practical implementation is often limited by structural instability, such as restacking and surface oxidation. In this study, we propose a strategy for the design of hybrid nanocomposites based on exfoliated Ti₃C₂T_x MXene embedded within a porous silica (SiO₂) matrix and further functionalized with cerium dioxide (CeO₂) nanoparticles. The SiO₂ matrix, synthesized via a sol–gel approach, ensures homogeneous dispersion, increased porosity, and thermal stability, effectively reducing MXene restacking. Simultaneously, CeO₂ nanoparticles create surface oxygen vacancies and enhance interfacial reactivity. Comprehensive structural, morphological, surface, and optical characterizations confirm the formation of stable, light-responsive nanoarchitectures with tailored textural properties. Furthermore, the obtained material exhibit promising photothermal-catalytic properties. This work offers a materials-oriented approach for engineering multifunctional MXene-based architectures with enhanced photothermal performance, exemplified by their potential application in the photothermo-catalytic CO₂ conversion into solar fuels, showcasing the broader possibilities enabled by these materials. Full article

The catalyst in methanol oxidation plays a pivotal role in direct fuel cell reaction. The aim of this work is to study the influence of polypyrrole polymer (PPy) added in the carbon Vulcan support for the methanol oxidation reaction. The catalytic active phase synthesized was nickel-based materials, which have been demonstrated to exhibit remarkable chemical stability in alkaline solutions. The metallic-active phase was supported at the PPy-carbon Vulcan matrix. PPy is a conductor polymer and the research of electric conduction in synergy with a carbon Vulcan and a Ni catalyst is scarcely reported. The morphology characterization of composite catalytic material was carried out by XRD, XPS, and TEM techniques. In turn, the catalytic activity of the composite is characterized by means of cyclic voltammetry (CV). Electrochemical impedance spectroscopy (EIS) showed the influence of PPy on the charge transfer resistance (Rch. t.). The results indicate that a decrease in the Rch. t. was associated with an increase in methanol oxidation; therefore, higher amounts of charge transfer is produced. Furthermore, the DEMS technique corroborates the EIS results, confirming elevated conversion toward oxidation products. In turn, the selectivity of the composite-catalytic support on the methanol oxidation was elucidated using in situ Raman spectroscopy. Full article