Search Results (802)

Smallholder dairy farms are central to rural livelihoods in Latin America, yet feeding strategies can shift environmental burdens across climate, land, and water dimensions. This study integrated cluster analysis and life cycle assessment to identify methane-related feeding typologies and assess their environmental trade-offs in smallholder dairy farms in the Mexican highlands. Twenty-nine farms from two dairy regions were classified by k-means clustering into two methane-emission-related farm typologies, which were subsequently characterized by their observed feeding profiles: conserved-forage-dominant (Cluster 1, n = 17) and green-forage-dominant (Cluster 2, n = 12). Their environmental performance was assessed with a cradle-to-farm gate life cycle assessment following ISO 14040/14044 and ReCiPe 2016 Midpoint across 18 impact categories. Feed production and ration supply were the main hotspots, contributing 72 to 100% of the total impacts. Global warming potential averaged 2.29 and 2.47 kg CO₂-eq per kg of raw milk in Clusters 1 and 2, respectively. Within the study sample, exploratory comparisons indicated higher marine eutrophication and land use in Cluster 1, whereas Cluster 2 showed higher fine particulate matter formation, terrestrial acidification, terrestrial ecotoxicity, and human carcinogenic toxicity (nominal p < 0.05). These potential trade-offs require validation in larger cohorts and with more geographically representative inventories. These findings show that similar milk outputs can arise from distinct feeding pathways with different environmental trade-offs and that greater reliance on fresh forage does not necessarily imply a more favorable environmental profile. Cluster-based characterization offers a practical basis for improving feed sourcing and ration design in dairy systems facing resource constraints. Full article

Fish processing generates substantial quantities of by-products, creating important management and valorization challenges, particularly in insular regions. This study provides a first-order quantification of fishery and aquaculture wastes in the Madeira archipelago. The methodology combined a feed-based mass-balance model, targeted data collection, stakeholder analysis, and valorization assessment. Organic matter (OM) released from marine cage aquaculture was estimated at approximately 851.6 t yr⁻¹ (dry weight), while fish by-products from processing activities in factories and retail stores generated approximately 938 t yr⁻¹ (wet weight). These waste streams differ substantially in their physical characteristics and management pathways, with aquaculture producing diffuse environmental discharges and processing activities generating concentrated and potentially recoverable residues. Structured stakeholder interviews identified limited scale and insufficient raw materials, logistics and labor as the main factors affecting valorization initiatives. A comparative multi-criteria assessment further evaluated potential valorization strategies based on environmental performance and economic viability. Despite the generation of organic residues, the results suggest that effective valorization is constrained less by total waste generation than by biomass fragmentation, logistical limitations, and restricted economies of scale, emphasizing the need for integrated circular management approaches. A combined approach, integrating farm usage of decaying OM from cage systems and locally supported valorization strategies is required to transition towards a more resource-efficient production system. Full article

Accurate ocean wave sensing in polar and other low-temperature marine environments is of great significance for marine environmental observation, climate research, and navigation safety. However, conventional wave sensors rely on external power supplies and suffer from poor stability under low-temperature and high-salinity conditions, making long-term self-powered waves sensing a significant challenge. Herein, a highly stable composite eutectogel electrode is developed by integrating sodium lignosulfonate, Fe³⁺ crosslinking, Zn²⁺-carboxylate coordination interactions, and a choline chloride/urea deep eutectic solvent (DES). The DES effectively suppresses solvent crystallization and endows the gel with excellent low-temperature tolerance, while the synergistic effect of metal coordination and multiple non-covalent interactions constructs a robust ion-conducting network with enhanced structural stability. Furthermore, eutectogel-based composite electrode architecture is designed to improve electrical conductivity and charge collection efficiency, thereby enabling stable electrical output under harsh marine conditions. Based on the as-prepared eutectogel electrode, a self-powered solid–liquid triboelectric nanogenerator is fabricated for ocean wave-motion sensing. The device can detect the wave amplitude, with an accuracy of 0.2 cm, and sense the frequency of waves ranging from 0.2 Hz to 1.6 Hz. More importantly, the SL-TENG exhibits excellent environmental adaptability, operating reliably in 3.5 wt% simulated seawater and at 0 °C. The current retention ratio reaches approximately 91% at 0 °C, which is significantly higher than that of the hydrogel-based device (≈6%). The remarkably low-temperature and salt-tolerant performance originates from the stable ion-transport network and anti-freezing characteristics of the eutectogel electrode. This work provides an effective strategy for constructing environmentally resilient eutectogel-based triboelectric devices and offers a promising route toward self-powered wave sensing systems for long-term deployment in harsh marine environments. Full article

Marine-derived bioactive compounds have attracted considerable attention as functional ingredients for food and nutraceutical applications due to their various biological activities. Among marine resources, macroalgae represent a sustainable and abundant source of structurally diverse bioactive compounds, including polyphenols, pigments, and polysaccharides. This review provides a comprehensive overview of macroalgal bioactive compounds, with particular emphasis on their sources, the environmental and seasonal factors influencing their composition, chemical classification and characteristics, extraction technologies, biological properties and food and nutraceutical applications. Particularly, attention is given to the molecular mechanisms underlying their antioxidant and anti-inflammatory effects, including radical scavenging, metal chelation, modulation of endogenous antioxidant defense systems, and regulation of key signaling pathways involved in inflammation. Green extraction techniques and encapsulation strategies for improving the stability, bioavailability, and functionality of macroalgal bioactives are critically discussed. Current applications in foods and nutraceutical products are reviewed alongside the major challenges related to biomass variability, large-scale production, standardization, and regulatory compliance. Overall, macroalgal bioactive compounds represent a promising class of sustainable health-promoting ingredients, and continued advances in cultivation, processing, extraction technologies, formulation, and regulatory frameworks will be essential to support their broader industrial utilization. Full article

Astaxanthin is a high-value xanthophyll carotenoid known for its antioxidant activity and potential health benefits that is becoming increasingly important in food, nutraceutical, and health-related applications. In recent years, growing interest in natural bioactive compounds has driven research on astaxanthin sources, bioactivity, functional properties, and its applications in food, nutraceutical, and health-related subjects. This review synthesizes current knowledge on the natural sources, extraction methods, stability, biological activities, and food applications of astaxanthin, with particular attention to challenges and opportunities relevant to food systems. The review discusses a food science-oriented perspective that connects molecular properties and biological functionality with processing stability, formulation strategies, and regulatory considerations. Special emphasis is given to emerging extraction and encapsulation methods, interactions with complex food matrices, and technological limitations affecting bioavailability and consumer acceptance. The review also highlights recent advances in sustainable production, valorization of marine by-products, and the potential role of astaxanthin in personalized nutrition and precision health frameworks. These approaches contribute to circular food systems by reducing food-processing waste, replacing synthetic antioxidants with natural alternatives, and supporting more resource-efficient and environmentally sustainable food production. Full article

Growing environmental concerns over petroleum-based plastics have increased interest in sustainable and biodegradable alternatives such as polyhydroxybutyrate (PHB). PHB is a naturally produced biopolymer synthesized by microorganisms and is widely recognized for its biodegradability, biocompatibility, renewability, and thermoplastic properties. Despite these advantages, PHB use remains limited by brittleness, high crystallinity, low thermal stability, a narrow processing window, and high production costs. This review discusses the production, properties, biodegradation behavior, and applications of PHB, with a focus on strategies to improve its performance. Modification approaches, including copolymerization, polymer blending, filler reinforcement, plasticization, and hybrid composite formulation, are critically reviewed to evaluate their effects on the thermal, mechanical, and processing behavior of PHB-based materials. The review also highlights recent developments in additive manufacturing, particularly fused deposition modeling/fused filament fabrication (FDM/FFF) for the extrusion of biodegradable PHB composite filaments. In addition, the biodegradation of PHB under various environmental conditions, including soil, compost, freshwater, marine, aerobic, and anaerobic environments, are discussed. Current challenges, research gaps, commercialization barriers, and future opportunities related to sustainable feedstocks, advanced composites, additive manufacturing, and circular economy integration are addressed. Overall, PHB shows strong potential as a sustainable alternative for packaging, biomedical, agricultural, and three-dimensional (3D) printing applications. Full article

Marine monitoring records collected from buoys and nearshore sensors are often affected by missing values, abrupt spikes, and short-term fluctuations. These errors are difficult to remove with a single detection or interpolation rule, especially when local anomalies and global outliers occur in the same sequence. This study develops a Multi-Strategy Fusion Architecture (MSFA) for cleaning marine environmental time-series data. In MSFA, DBSCAN is not applied directly to the raw observations; instead, the time index and measurement value are first normalized into a common feature space, where local density anomalies can be detected more consistently. IQR screening is then used to identify global extreme values. After abnormal positions are marked, the repair result is estimated from two complementary sources: linear interpolation, which follows local temporal change, and a moving average based only on neighboring valid observations, which reduces random noise. Their contributions are adjusted according to local reliability rather than fixed manually. Because initial repair may still leave small residual errors, we further use a Combined Residual Metric (CRM) with a median/MAD-based threshold to recheck the repaired sequence and update the abnormal-position set when necessary. Experiments on the 2020 Dongying offshore buoy dataset and a self-collected nearshore dataset show that MSFA achieves AUROC/AUPRC/NRMSE values of 0.896/0.855/0.066 and 0.986/0.915/0.0653, respectively. Compared with DBSCAN+LOF, DBSCAN+Transformer, and IQR+Sigmoid, MSFA improves AUROC and AUPRC by about 12–25% on average and reduces NRMSE by more than 40%. These results indicate that the proposed method can improve the usability of noisy and incomplete marine monitoring data while keeping the cleaning process interpretable. Full article

Small non-coding RNAs (sRNAs) are ubiquitous post-transcriptional regulators that enable rapid bacterial adaptation to fluctuating environments. Previous reviews have largely focused on sRNA mechanisms in model organisms. This review integrates computational prediction, meta-omics-based discovery, and synthetic biology applications of small regulatory RNAs in marine and environmental prokaryotes, providing a multi-layered perspective from identification to functional and engineering applications. The current landscape of sRNA identification tools is critically evaluated, with emphasis on strategies to overcome challenges such as false-positive predictions. Recent advances in mapping the RNA interactome and emerging evidence of previously underappreciated roles of sRNAs in environmental adaptation are discussed. Additionally, metagenomic and metatranscriptomic studies revealing the diversity of environmental sRNAs in uncultured microbial communities are summarized, highlighting their ecological significance. Finally, a curated overview of synthetic sRNA applications in metabolic engineering, including target genes and enhanced product yields, is provided as a resource for strain engineering. Collectively, this review provides a holistic view of prokaryotic sRNA biology, distinguishing it from more narrowly focused studies. Overall, sRNAs are highlighted as key regulatory elements linking microbial environmental adaptation with emerging biotechnological applications through advances in meta-omics guided discovery and synthetic RNA engineering. Full article

To achieve the stabilization and high-value utilization of Basic oxygen furnace (BOF) slag leaching residues, this study proposes a synergistic strategy combining compaction and pressurized carbonation. The effects of moisture content, molding pressure, holding time, and carbonation duration on the carbonation efficiency, mechanical properties, and surface characteristics of the residue briquettes were systematically investigated. Using a combination of orthogonal and single-factor experiments with the carbonation weight gain rate as the primary indicator, this study reveals the intrinsic mechanism by which forming parameters regulate CO₂ mass transfer and reaction efficiency through pore structure modification. The results indicate that moisture content is the dominant factor influencing carbonation efficiency, with an optimal moisture range achieving a balance between reaction kinetics and gas diffusion. Furthermore, molding pressure and holding time dictate the effective carbonation depth by altering the pore size distribution. The carbonation process significantly enhances the compressive strength of the specimens, reduces the surface pH from 12.45 to approximately 10.2, and decreases surface roughness, thereby improving environmental compatibility. These findings provide a theoretical foundation for the high-value application of leached steel slag in marine ecological materials and carbon sequestration. Full article

In marine environmental monitoring, target detection, identification and positioning, and other missions, the detection performance of unmanned underwater swarms directly depends on their deployment strategy. To address complex task scenarios requiring a balance between detection range, positioning accuracy, and connectivity, a multi-objective deployment optimization method is proposed in this paper. First, based on realistic underwater acoustic environment modeling using the Bellhop3D model, a collaborative detection model, positioning accuracy model, and network connectivity model for unmanned underwater platforms are established. These three models are integrated with weighted coefficients to construct the objective function, whose maximum value is sought to achieve optimal detection performance of the unmanned swarm. Second, an improved cuckoo search (ICS) algorithm is designed as the solution tool. The results demonstrate that the proposed deployment model achieves multi-objective balance and exhibits significant advantages over single-objective optimization models. Furthermore, the ICS algorithm obtains better solution quality than the compared intelligent optimization algorithms, providing an effective optimization tool for deployment in complex underwater acoustic environments. Full article

Polyhydroxybutyrate (PHB), a microbial polyester belonging to the polyhydroxyalkanoate (PHA) family, has emerged as one of the most promising biodegradable alternatives to conventional petroleum-derived plastics. Its inherent marine biodegradability (typically mineralizing within months depending on material geometry and ambient temperature), biocompatibility, and ability to be synthesised from renewable and waste-derived feedstocks position PHB as a key candidate for supporting the transition towards a circular bioeconomy. Despite these advantages, widespread commercial adoption remains limited by high production costs, processing challenges, and performance constraints relative to established commodity plastics and competing biopolymers. This review critically evaluates the current state of PHB development from the perspective of sustainable commercialisation. Key aspects discussed include microbial biosynthesis pathways, feedstock selection, upstream fermentation strategies, downstream recovery technologies, and technoeconomic considerations influencing industrial feasibility. The intrinsic thermal, mechanical, and degradation characteristics of PHB are examined alongside modification approaches such as copolymerisation, polymer blending, plasticisation, and composite reinforcement that have been developed to overcome certain inherent physical–mechanical properties, narrow processing windows, and limited functional performance. Furthermore, characterisation methodologies, environmental degradation behaviour, and emerging industrial applications are assessed within the context of market requirements and sustainability objectives. Particular emphasis is placed on identifying the interconnected technical and economic bottlenecks that continue to hinder large-scale deployment, including feedstock costs, fermentation scalability, downstream processing expenses, and material performance trade-offs. By integrating advances across the entire PHB value chain, this review highlights current opportunities, remaining challenges, and future priorities required to enable the sustainable and economically viable commercialisation of PHB-based materials. Full article

With the rapid development of offshore engineering, marine cranes are widely deployed in critical maritime operations, such as the precision installation of wind turbine blades. However, their highly coupled three-dimensional spatial dynamics, uncertain payload mass, and susceptibility to severe external sea wave disturbances pose significant challenges in achieving fast, accurate payload transportation and rapid anti-swing performance. To address these issues, this paper proposes a novel energy-based intelligent coupling control strategy utilizing fuzzy logic and adaptive gravity compensation for 5-DOF (5-Degrees of Freedom) marine cranes. Firstly, to handle the severe underactuation and facilitate natural energy dissipation, a novel set of error coupling variables is constructed, organically linking the actuated crane structure with the unactuated payload swing dynamics. Then, an adaptive gravity compensation mechanism is designed to dynamically estimate the uncertain payload mass in real time, eliminating the need for precise prior mathematical models. Subsequently, to counteract complex external environmental disturbances and unmodeled internal dynamics, a targeted fuzzy observer is developed based on the universal approximation theorem, providing robust, real-time perturbation compensation. The sufficient conditions for the asymptotic stability of the closed-loop system are rigorously proven based on the Lyapunov method and LaSalle’s invariance principle. Finally, extensive comparative simulations are conducted, demonstrating that the proposed method significantly improves the operational accuracy, anti-swing capability, and safety of marine cranes under varying load conditions and persistent wave disturbances. Full article

Sicily is a Mediterranean island region whose economy is based especially on tourism, with tourists being attracted to its beaches. The whole coastline of the island, including its minor islands, is 1745 km. At the moment, considering the whole period analyzed by the Coastal Plan of Sicilian Region (2008–2024), about 115 km of the 683 km of the main island’s sandy coastline present erosion problems that affect 23% of its unprotected coastline (506 km). Some of these problems are threatening Sicily’s economic and important historical assets as well as its cultural heritage; 177 km of protected beaches, using hard structure, have lost their original beauty. In the last fifty years, about 2.5 km² of beaches were lost due to erosion, causing damages worth approximately 5 billion Euros. Current coastal management guidelines identify artificial beach nourishment as the most sustainable strategy for protecting the insular economy against the accelerating impacts of climate change. Successful nourishment, however, hinges on the availability of vast quantities of borrow material that must be granulometrically, compositionally, and chromatically compatible with native beach sediments. While subaerial quarries are being phased out due to their irreversible environmental degradation and logistical inefficiency, as well as local “ephemeral” sources (such as harbor dredging or over-alluvial deposits) providing insufficient volumes, the research has shifted toward Remote/Relict Marine Sediment Deposits (RMSDs). This study evaluates the strategic potential of RMSDs as a high-volume, low-impact resource for coastal defense. By integrating the geological, morphological, and sedimentological characteristics of the Sicilian continental shelf within a GIS framework, we have delineated potential dredging sectors. These areas are bounded by the −30 m isobath (the lower limit of Posidonia oceanica meadows) and the −200 m isobath, which represents the current operational limit of Jumbo Trailer Suction Hopper Dredgers (TSHDs). A multi-criteria constraint analysis was performed, categorizing environmental and infrastructural overlaps into fatal flaws (prohibitive) and non-prohibitive constraints. This subtractive spatial analysis reveals that approximately 6500 km² of the Sicilian shelf may be eligible for resource exploitation concessions, pending site-specific, high-resolution surveys. Full article

Marine biofouling on aquaculture netting compromises mass transfer and structural performance, particularly in high-fouling marine environments. Here, a biomimetic antifoulant based on a butenolide scaffold was synthesized and incorporated into silicone coatings to achieve effective antifouling performance. The antifoulant exhibited bactericidal activity against Escherichia coli, Vibrio harveyi, and Staphylococcus aureus, while coating characterization showed increased hydrophobicity and reduced water uptake with minimal loss of adhesion. Algal attachment assays revealed significant inhibition of Isochrysis zhanjiangensis, with an optimal loading of 8 wt%. Notably, planktonic algal growth remained largely unaffected, indicating a surface-mediated mechanism. Mechanistically, the antifoulant is proposed to interfere with quorum sensing-regulated microbial behavior, thereby suppressing initial colonization and biofilm formation. Field immersion tests over six months confirmed sustained antifouling performance with low fouling coverage and stable coating integrity. These findings demonstrate a promising strategy for environmentally compatible biofouling control in offshore aquaculture. Full article

Cold spray additive manufacturing (CS) has emerged as a transformative solid-state deposition technique for designing advanced functional surfaces with tailored tribological performance. By accelerating micron-scale particles to supersonic velocities and depositing them below their melting point, CS enables the fabrication of dense, oxidation-resistant coatings with strong metallurgical bonding and beneficial compressive residual stresses. These distinctive attributes create unique opportunities for the design-driven engineering of wear-resistant surfaces across aerospace, automotive, marine, biomedical, and industrial sectors. Despite a growing literature on CS processing and properties, a comprehensive framework linking design principles encompassing material selection, coating architecture, process parameter optimization, and post-processing strategies to tribological outcomes is absent from the field. This review addresses that gap by critically examining the design space of CS coatings and positioning tribological performance as an outcome of deliberate engineering decisions. The relationships between coating architecture and tribological behavior, specifically friction control, wear resistance, adhesion-cohesion integrity, and surface roughness, are examined under varying environmental and loading conditions. Design strategies involving composite and hybrid coatings incorporating solid lubricants, ceramic reinforcements, and nanostructured architectures are discussed in the context of achieving specific functional objectives. The influence of process parameters, such as particle velocity, gas temperature, substrate preparation, and post-treatments including heat treatment, friction stir processing, and laser shock peening, on tribological outcomes is critically synthesized. Environmental performance under high-temperature, corrosive, and extreme wear conditions is analyzed through a design lens. A design decision framework summarizing material-process-property linkages for CS tribological coatings is presented to provide practical guidance for engineers and researchers. Future directions include AI-driven process optimization, multi-material architectures, and the integration of CS within broader design-for-manufacturing workflows. Full article