Search Results (243)

In an era defined by the imperative for sustainable, high-performance materials, this review examines the development and utility of key ester and ether derivatives from both cellulose and hemicellulose sourced from lignocellulosic biomass, with a special emphasis on waste feedstocks. Our findings indicate that these derivatives exhibit tunable physicochemical properties, enabling their broad use in established industrial sectors while also fueling the emergence of novel technological applications in nanotechnology, controlled delivery, tissue engineering, environmental remediation, electronics, and energy fields. This dual-polysaccharide platform demonstrates that underutilized biomass streams can be repurposed as valuable feedstocks, promoting a circular supply chain and supporting more sustainable solutions, thereby aligning with the goals of eco-friendly innovation in materials science. Future progress will likely depend on integrating green chemistry synthesis routes, optimizing waste-to-product conversion efficiency and scalability, and engineering derivatives for multifunctional performance, thus bridging the gap between commodity-scale use and high-tech material innovation. Full article

Soil contamination by heavy metals from industrial and mining activities poses a significant global threat to both environmental and human health, particularly in brownfields—abandoned or underutilized industrial areas that frequently accumulate pollutants. Climate change exacerbates this issue by intensifying extreme events such as floods, which can enhance contaminant mobility and compromise the reliability of conventional remediation methods. This study evaluated the in situ application of a sustainable soil washing technique based on hydrocycloning at a contaminated site in Canoas (Porto Alegre, Brazil), a flood-prone area heavily impacted by the 2024 climate disaster. The method physically separates heavy metals by concentrating them into a fine, high-contamination fraction for controlled disposal. Approximately 3019 m³ of soil was treated, recovering 93.4% of the material (coarse and fine sand) for potential reuse and isolating only 6.6% (200 m³) as hazardous waste. Chemical analyses confirmed that the recovered fractions complied with regulatory limits for heavy metals, while contaminants were effectively retained in the sludge and safely disposed of through landfills. During the April–May 2024 flood events, although the site was inundated, no significant erosion of the backfilled material was registered. The results support hydrocycloning-based soil washing as a robust and climate-resilient approach to adaptive remediation in contaminated environments. Full article

Corn stover and plastic waste, severely underutilized feedstocks generated in the U.S., could be co-pelletized to produce fuel for cement production. High-density polyethylene bags (0–25% in 5% increments, dry basis) and corn stover were co-pelletized using a flat ring pellet mill with die diameters of 6 and 8 mm. Physical and chemical properties were assessed to determine pellet quality. These results informed techno-economic and life cycle greenhouse gas emissions (GHGe) analyses for a Midwestern plant producing 400,000 metric tons of pellets annually. The system boundary included feedstock acquisition at the pellet plant, size reduction, co-pelletization, and transportation of the pellets to the cement plant by rail. Total resource requirements in terms of raw materials, labor, fuel, equipment, the facility, and utilities were estimated. It was determined that the pellets would be delivered to the cement plant at USD 112.4–138.6/t pellets. The life cycle analysis estimated a total GHGe of 1621.1–1753.1 kg CO₂e/t pellets associated with the pellet production, transportation, and combustion. The results suggest that substituting 25% of the thermal energy requirement of a cement plant with a 1.1 million t clinker annual production capacity with plastic–stover pellets would reduce the GHGe by 2.8% compared to 100% of the total energy requirement supplied by coal. Full article

The incorporation of bioactive natural compounds into biomedical applications offers a promising route to enhance therapeutic efficacy while supporting sustainability. In this study, we investigated the synergistic potential of Sericin, a silk-derived biopolymer, and Chelidonium majus L. (C. majus), a medicinal plant with a diverse phenolic profile, in relation to biological activities relevant for wound care and infection control. A combined experimental strategy was applied, integrating detailed chemical characterization of C. majus extracts with antimicrobial and cytocompatibility assays across different Sericin–plant extract ratios (1:1, 1:2, 2:2, and 2:1). Phytochemical analysis identified and quantified 57 phenolic compounds, including high levels of flavonoids (quercetin, kaempferol, isorhamnetin) and phenolic acids (caffeic and ferulic acid). Salicylic acid (123.6 µg/g), feruloyltyramine (111.8 µg/g), and pinocembrin (98.4 µg/g) were particularly abundant, compounds previously reported to disrupt microbial membranes and impair bacterial viability. These metabolites correlated with the strong antimicrobial activity of C. majus against Gram-positive strains (MIC = 5–10 mg/mL). In combination with Sericin, antimicrobial performance was ratio-dependent, with higher proportions of C. majus (2:1) retaining partial inhibitory effects. Cytocompatibility assays with HFF1 fibroblasts demonstrated low antiproliferative activity across most formulations (GI₅₀ > 400 µg/mL), supporting their potential safety in topical applications. Collectively, the results indicate a concentration-dependent interaction between C. majus phenolics and the Sericin protein matrix, reinforcing their suitability as candidates for natural-based wound healing materials. Importantly, the valorization of Sericin, an underutilized byproduct of the silk industry, together with a widely accessible medicinal plant, underscores the ecological and economic sustainability of this approach. Overall, this work supports the exploration of the development of biomaterials with potential for advancing tissue repair and wound management. Full article

Starch is a promising alternative to petroleum-based polymers due to its biodegradability and renewable nature. However, its widespread use in non-food applications raises ethical concerns. Mango kernels, a major byproduct of mango processing, represent an abundant yet underutilized starch source. However, conventional starch extraction requires costly purification steps with significant environmental impact. This study explores the development of extruded biocomposites, using corn starch and mango kernel flour (MKF) as a more sustainable alternative. The influence of lignin, extractives, amylose, and amylopectin content on the material properties was assessed. MKF was obtained by removing both tegument and endocarp from the mango kernels, grinding them in a colloidal mill, and finally drying the ground kernels. The resulting flour was blended with corn starch, processed in an internal mixer, and injection-molded. The composites were characterized through mechanical testing, water absorption analysis, colorimetry, and UV absorption assays. Notably, the composite containing ~20% MKF exhibited mechanical properties comparable to commercial polyethylene (PE-PB 208), with a tensile strength of 9.53 MPa and a Young’s modulus of 241.41 MPa. Additionally, MKF enhanced UVA protection. These findings suggest that mango kernel flour can partially replace starch in the production of injection-molded biopolymers, offering a more sustainable approach to biodegradable plastic development. Full article

Alkali-activated materials (AAMs) offer a promising low-carbon alternative to Portland cement, but their development has been dominated by fly ash and slag, whose availability is increasingly limited. This research explores waste brick powder (WBP) and metakaolin residue (RN), two abundant yet underutilized by-products, as blended precursors for sustainable binder design. The novelty lies in demonstrating how complementary chemistry between crystalline-rich WBP and amorphous RN can overcome the drawbacks of single-precursor systems while valorizing construction and industrial residues. Pastes were prepared with varying WBP/RN ratios, activated with alkaline solutions, and characterized by Vicat setting tests, isothermal calorimetry, XRD with Rietveld refinement, MIP, SEM, and mechanical testing. Carbon footprint analysis was performed to evaluate environmental performance. Results show that WBP reacts very rapidly, causing flash setting and limited long-term strength, whereas the incorporation of 30–50% RN extends setting times, sustains dissolution, and increases amorphous gel formation. These changes refine the formed reaction products, leading to compressive strengths up to 39 MPa and flexural strengths of 8 MPa at 90 days. The carbon footprint of all blends remained 392–408 kg CO₂e/m³, thus providing about a 60% improvement compared to conventional Portland cement paste. The study establishes clear design rules for waste-derived blended precursors and highlights their potential as circular, low-carbon binders. Full article

Pineapple leaf fibers (PALFs), obtained from abundant yet underutilized pineapple leaf residues, represent a promising feedstock for producing fibrillated cellulose. In this work, cellulosic fibers were isolated and characterized by Fiber Quality Analysis (FQA), showing lengths between 0.33 and 0.47 mm and widths of 12.2 µm after organosolv pulping using ethanol and acetic acid as a catalyst, followed by hydrogen peroxide bleaching with diethylenetriaminepentaacetic acid as a chelating agent. The cellulosic fibers were then subjected to TEMPO-mediated oxidation and subsequently disintegrated by microfluidization to produce micro-/nanofibrillated cellulose (MNFC) with a carboxylate content of 0.85 and 1.00 mmol COO⁻/g, zeta potential of −41 and −53 mV, and average widths of 15 and 12 nm for unbleached and bleached nanofibrils, respectively. The nanofibrillation yields were 73% and 68% for the bleached and unbleached MNFC samples, indicating the presence of some non-fibrillated or partially fibrillated fractions. X-ray diffraction analysis confirmed preservation of cellulose type I crystalline structure, with increased crystallinity, reaching 85% in the bleached MNFC. These findings demonstrate the feasibility of a sequential process, combining organosolv pulping, hydrogen peroxide bleaching, TEMPO-mediated oxidation, and microfluidization, for preparing MNFC from pineapple leaf fibers. Overall, this study highlights pineapple leaf residues as a sustainable source of MNFC, supporting strategies to transform agricultural waste into valuable bio-based materials. Full article

This systematic literature review investigates the factors influencing indoor environmental satisfaction in vernacular architecture, with particular attention to sustainability and sociocultural contexts. Drawing on 105 peer-reviewed studies published over the past two decades, the analysis employed thematic synthesis and cluster analysis to identify key design features, theoretical underpinnings, and variables affecting occupant satisfaction. Five major theories emerged, with Sustainability Theory, Bioclimatic Architecture Theory, and Ecological Systems Theory most frequently applied. Cluster analysis of 62 variables produced eight thematic categories, offering a structured basis for hypothesis development and integrative model formulation. The review further identified critical research gaps, including limited empirical validation, methodological inconsistencies, and underutilization of theory in explaining outcomes. Findings reveal that vernacular design features such as courtyards, shading devices, and materiality strongly contribute to SIEQ, while contemporary transitions risk diminishing comfort. This review highlights critical research gaps, particularly evaluation voids and theoretical underuse, and proposes integrative directions for architects and policymakers. Full article

The functionalization of textiles with nanomaterials through green synthesis offers a promising pathway for sustainable material innovation. This study explores the in situ green synthesis of silver nanoparticles (AgNPs) onto cotton fabrics using Solanum tuberosum (potato) peel extract as a natural reducing and stabilizing agent. The synthesis conditions were optimized by varying silver nitrate concentration, extract volume, temperature, pH, and reaction time, after which the optimized protocol was applied for fabric treatment. The presence and distribution of AgNPs were confirmed through UV-Visible spectroscopy, Fourier-transform infrared spectroscopy, scanning electron microscopy and dynamic light scattering. The treated fabrics demonstrated strong and durable antibacterial performance, with inhibition zones of 23 ± 0.02 against Escherichia coli and 16 ± 0.01 against Staphylococcus aureus. Notably, antibacterial activity was retained even after 20 washing cycles, demonstrating the durability of the treatment. Mechanical testing revealed a 32.25% increase in tensile strength and a corresponding 10.47% reduction in elongation at break compared to untreated fabrics, suggesting improved durability with moderate stiffness. Air permeability decreased by 8.8%, correlating with the rougher surface morphology observed in Scanning Electron Microscopy images. Thermal analysis showed a decrease in thermal stability relative to untreated cotton, highlighting the influence of AgNPs on degradation behavior. Overall, this work demonstrates that potato peel waste, an abundant and underutilized biomass, can be used as a sustainable source for the green synthesis of AgNP-functionalized textiles. The approach provides a cost-effective and environmentally friendly strategy for developing multifunctional fabrics, while supporting circular economy goals in textile engineering. Full article

Within the context of Industry 4.0, industrial systems are increasingly integrating digital tools such as discrete-event simulation (DES) and digital twins to enhance operational performance and facilitate data-driven decision-making. This research focuses on the design and implementation of an innovative digital twin to diagnose and optimize the productivity of manufacturing systems. A key advancement of this tool involves the integration of a material flow simulator, specifically WITNESS Horizon, with a suite of mathematical and digital models to create an integrated manufacturing digital tool. Rather than modeling individual pieces of equipment or isolated workstations, this digital twining approach encompasses the entire manufacturing architecture. To demonstrate the capabilities and efficacy of this integrated tool, we applied it to a real-world case study: the “Hub R2-11” production line. Utilizing the diagnostic features of the tool for this case study, we identified significant bottlenecks, revealing that over 70% of the conveyor was blocked and more than 60% of the workstation was underutilized. Utilizing the simulation and optimization features of the tool, we increased productivity by restructuring the manufacturing architecture. This involved implementing parallel machining, regulating inputs, and incorporating robotic palletizing. The resultant manufacturing architecture demonstrated a substantial improvement, increasing weekly pallet output from 17 to 41 while reducing conveyor block time by more than 50%. Additionally, a financial assessment indicated a favorable Net Present Value (NPV) and an Internal Rate of Return (IRR) exceeding 35% over three years. The research presented here employs a digital approach grounded in realistic operational constraints, effectively bridging technical innovations with economic feasibility. The findings underscore that this integrated manufacturing digital tool presents a scientifically robust and economically sound strategy for optimizing production systems. Full article

Hazel wood (Corylus avellana L.) is widespread in Europe but remains underutilized in industry. This study evaluated its potential as a raw material for three-layer particleboards for furniture and interior use. Boards were produced with barked and debarked hazel particles at substitution levels of 0–100% with industrial pine. All variants fulfilled EN 312 P2 requirements. Hazel particles increased the bulk density (211 for debarked vs. 160 kg m⁻³ for pine wood), affecting handling. The modulus of rupture remained stable (11.5–12.7 N mm⁻²), while the modulus of elasticity declined with the hazel content but stayed above 1600 N mm⁻². Internal bond strength improved markedly, reaching 1.63–1.66 N mm⁻² at full substitution, and screw withdrawal resistance rose to ~200 N mm⁻¹. However, dimensional stability worsened at 100% hazel, with higher thickness swelling and water absorption, especially for debarked material. Boards from fully debarked hazel also showed reduced core density to below 80% of the nominal density, potentially influencing bonding. The findings indicate that up to 50% hazel substitution is feasible without performance loss, while full replacement requires optimization of pressing and adhesives. Hazel wood thus represents a promising, sustainable alternative to conventional species, supporting more diversified raw material use in particleboard production. Full article

The global issues of resource depletion and environmental pollution have led to increased interest in a circular bioeconomy focusing on converting renewable biomass into functional biomaterials. This article explores the transformative potential of hemicellulosic biogels as a sustainable platform to address critical societal challenges, such as water scarcity, food solutions and environmental pollution. Derived from hemicelluloses, an abundant and underutilized polysaccharide in lignocellulose biomass, these biogels offer a fundamentally new approach to developing high-performance, ecofriendly based materials. The review examines their development, characterization, and diverse applications in water treatment, food, agriculture, adhesive and coating systems. In water treatment, these gels exhibit exceptional performance, demonstrating a maximum NaCl uptake of 0.26 g/g and rapid pseudo-second-order adsorption kinetics for desalination. They also show high selectivity for heavy metal removal, with a remarkable binding capacity for lead if 2.9 mg/g at pH 5. For adhesive and coating applications, hemicellulose crosslinked with ammonium zirconium carbonate (AZC) forms water-resistant gels that significantly enhance paper properties, including gloss, smoothness, liquid resistance, and adhesive strength. Furthermore, hemicellulosics exhibit controlled biodegradation in physiological solutions while maintaining their mechanical integrity, underscoring their broad application promise. Overall, this review highlights how hemicellulose-based hydrogels can transform a low-value byproduct from biorefinery into high-performance solutions, contributing significantly to a sustainable economy. Full article

This study provides a comprehensive and systematic review of hyperspectral remote sensing in urban areas, with a focus on the evolving roles of airborne and spaceborne platforms. The main objective is to assess the state of the art and identify current trends, challenges, and opportunities arising from the scientific literature (the gray literature was intentionally not included). Despite the proven potential of hyperspectral imaging to discriminate between urban materials with high spectral similarity, its application in urban environments remains underexplored compared to natural settings. A systematic review of 1081 peer-reviewed articles published between 1993 and 2024 was conducted using the Scopus database, resulting in 113 selected publications. Articles were categorized by scope (application, method development, review), sensor type, image processing technique, and target application. Key methods include Spectral Unmixing, Machine Learning (ML) approaches such as Support Vector Machines and Random Forests, and Deep Learning (DL) models like Convolutional Neural Networks. The review reveals a historical reliance on airborne data due to their higher spatial resolution and the availability of benchmark datasets, while the use of spaceborne data has increased notably in recent years. Major urban applications identified include land cover classification, impervious surface detection, urban vegetation mapping, and Local Climate Zone analysis. However, limitations such as lack of training data and underutilization of data fusion techniques persist. ML methods currently dominate due to their robustness with small datasets, while DL adoption is growing but remains constrained by data and computational demands. This review highlights the growing maturity of hyperspectral remote sensing in urban studies and its potential for sustainable urban planning, environmental monitoring, and climate adaptation. Continued improvements in satellite missions and data accessibility will be key to transitioning from theoretical research to operational applications. Full article

The extraction of cellulose from underutilized forest residues can diversify bio-based material supply chains and reduce pressure on commercial pulps. In this study, cellulose was isolated from Tibouchina lepidota (Bonpl.) Baill pruning residues through an alkaline–acid–oxidative protocol, and its suitability for polymeric applications was evaluated. Two granulometric fractions (250 µm and 125 µm) were used; the yields were 4.73 ± 0.12 g and 3.62 ± 0.11 g per 50 g of biomass, equivalent to 90.5% and 92.8% recovery, respectively (fractional remains as bleached pulp after removal of non-cellulosic components). Fourier Transform Infrared spectroscopy (FTIR) showed the disappearance of lignin and hemicelluloses bands and a pronounced β-glucopyranosic signal at 894 cm⁻¹, indicating high purity. Selective solubility in 17.5% NaOH classified the polymer as β-cellulose, suitable for wet spinning and film regeneration. Optical microscopy revealed smooth fibers of 25–50 µm length and 0.5–1 µm diameter, with aspect ratios ≥ 50, indicating favorable morphology for load transfer in composites. Statistical analysis (Shapiro–Wilk, F-test, and Student’s t-test) confirmed the significant influence of particle size on yield (p < 10⁻¹⁵). Overall, T. lepidota residues constitute a viable source of high-purity β-cellulose, whose molecular integrity and microstructure satisfy the requirements of sustainable polymeric manufacturing. Full article

Background/Objectives: Maxillary defects, whether congenital or acquired, can compromise chewing, speech, and aesthetics. This systematic review aimed to evaluate the application and characteristics of definitive palatal obturators in the rehabilitation of such defects, analyzing techniques of fabrication, materials, outcomes of the fabrication, and limitations reported in the literature. Methods: The review was conducted in accordance with PRISMA 2020 guidelines and was registered in PROSPERO (ID: 1011648). A comprehensive search was performed in PubMed, Scopus, Lilacs, and Google Scholar for studies published from 1 January 2014 to 1 January 2025. Inclusion criteria comprised adult patients treated with definitive palatal obturators and with reported follow-up. Exclusion criteria included studies on children, animals, or lacking patient data. Two reviewers independently screened studies and assessed eligibility. Bias was evaluated qualitatively across five domains. No meta-analysis was conducted; data were synthesized descriptively using charts and tables. The study was funded by the Italian Ministry of Health—Current Research IRCCS. Results: A total of 59 studies involving 83 patients (46 males, 37 females; mean age 54.6 ± 13.8 years) were included. Mucormycosis and squamous cell carcinoma were the primary causes of defects. Conventional impressions using alginate and silicone were most common, while digital techniques were reported in only 6.6% of cases. All definitive obturators were fabricated using acrylic resin, with some featuring hollow bulbs, velopharyngeal extensions, or magnetic retention. Multiple sources of bias were observed. Conclusions: Definitive palatal obturators provide effective functional and aesthetic rehabilitation for maxillary defects. However, evidence is limited by methodological weaknesses, lack of standardization, and underutilization of digital technologies. Future studies should focus on improving reporting quality, adopting innovative fabrication protocols, and generating higher-level clinical evidence to support best practices. Full article