Recycling natural fibers plays a crucial role in promoting environmental sustainability by reducing waste, conserving resources, and lowering the environmental impact of textile production. Natural fibers such as cotton, wool, and linen are biodegradable, but when disposed of in landfills, they contribute to pollution and resource depletion. By recycling these materials, we not only extend the life cycle of valuable resources but also decrease the demand for virgin fiber production, which often involves intensive water, energy, and chemical use. Additionally, recycling natural fibers supports a circular economy, encouraging more responsible consumption and production practices while helping to reduce greenhouse gas emissions and textile waste accumulation. On the other hand, the reinforcement of polymer matrices with natural fibers is opening new avenues for enhancing both the environmental and economic sustainability of the polymer industry, while also broadening their applications in engineering. This study investigates the additive manufacturing of composite materials reinforced with short coffee waste shells. A range of characterizations—including scanning electron microscopy and tensile testing—are presented, along with a statistical analysis of the tensile results using Weibull distribution. By incorporating this organic waste into engineered composites, the useful life of coffee shells is extended, contributing to environmental sustainability, and offering potential socio-economic benefits at the local level. The results demonstrate that the produced filaments possess promising mechanical strength and suggest the viability of scaling up the manufacturing process.

Hydroxyapatite is a mineral composed of hydrated calcium phosphates. As it is the main mineral component of human bone, it is widely used in the fabrication of alloplasts for bone tissue regeneration treatments, known as scaffolds [1][2]. Scaffolds serve as a cellular matrix for the development of new bone tissue; therefore, they must have a porous structure, adequate mechanical strength, and be composed of biocompatible material [3]. To meet these criteria, additive manufacturing techniques, such as fused deposition modeling (FDM) 3D printing, are employed as an alternative for controlling structure and mechanical strength. However, if the printer operates by extruding thermoplastic material, it is necessary to synthesize polylactic acid (PLA) filament loaded with hydroxyapatite to incorporate the bioceramic into the scaffold [4]. Hydroxyapatite can be obtained through various synthesis routes or from synthetic or natural resources. In this study, hydroxyapatite was extracted from the byproduct of the Arapaima gigas fish and used to produce filaments for 3D printing. The scales were subjected to chemical treatment with NaOH and thermal treatment with sintering at 600 ºC in an oxygen-rich environment. The characterizations performed were TG, DTG, DSC, FTIR, and SEM. After these characterizations, the sample was subjected to a thermal treatment at 700 ºC, followed by the same analyses. The filaments were produced by extrusion and were loaded with 1% w/w of hydroxyapatite extracted from the scales of Arapaima gigas. The filaments were subjected to tensile testing according to ASTM C1557-20. Thermal analysis revealed that the sample sintered at 600 ºC did not undergo complete removal of organic volatiles, with mass losses of 3.6% in the range of 75 ºC – 100 ºC due to residual water; 1.1% in the range of 280 ºC – 700 ºC due to collagen residue; and 2.93% between 600 ºC – 742 ºC due to the loss of structural water from hydroxyapatite. The sample sintered at 700 ºC showed little mass loss, with a total loss of 1.68%, and a maximum degradation temperature at 619 ºC, related to the structural water present in hydroxyapatite. In both samples, FTIR analyses revealed the characteristic bands of PO₄³⁻ anions at 1091 cm⁻¹; 1022–1018 cm⁻¹; 602–563 cm⁻¹, and the presence of CO₃²⁻ ions at 1450 cm⁻¹, 1411 cm⁻¹, and 871 cm⁻¹. Scanning electron microscopy (SEM) micrographs showed that the samples sintered at 600 ºC presented agglomerates of inorganic particulates without a defined morphology. Sintering at 700 ºC promoted the growth of particulates larger than 200 µm with polygonal shapes, tending toward hexagonal formation.

In recent years, the use of lignocellulosic natural fibers (LNFs) as reinforcements in composites has increased significantly [1,2]. This trend is driven by environmental concerns and the need to reduce dependence on petroleum reserves [3]. Consequently, there is a growing interest in environmentally friendly materials aligned with the principles of sustainable development. LNFs are considered a promising alternative due to their low cost, renewability, biodegradability, and low specific weight [4,5]. As a result, these fibers have been employed across various technological sectors, particularly in engineering applications. Hybrid composites combining natural and synthetic fibers are being investigated to enhance mechanical performance while reducing weight and cost, balancing the advantages and disadvantages of each constituent. Thus, the present study investigates the influence of different stacking configurations involving aramid fabric and jute fibers, and separately, aramid fabric and sisal fibers, as reinforcement components in composite materials. These composite systems were subjected to ballistic testing using .22 caliber ammunition. Based on the measurements of impact and residual velocities, the absorbed energy and the ballistic limit velocity of the projectile were calculated. Preliminary results indicated that the incorporation of aramid layers into the sisal-based composites enhanced the energy absorption under projectile impact, likely due to modifications in the fracture mechanisms of the composites. In contrast, the jute-based composite did not exhibit significant changes.

A growing demand for research about ballistic armor shields follows the increase of violence around the world. Ultimately, different composite materials with polymeric matrices have already presented the minimum performance as an individual protection required with cheaper and lower density, such as those reinforced with natural lignocellulosic fiber (NLF). The Cyperus malaccensis, a type of sedge fiber, is already used in simple items like ropes, furniture, and paper, but has not yet been investigated as composite reinforcement for possible ballistic protection applications. Therefore, composite plates were prepared for the ballistic tests, based on the condition of 30 vol% alkali treated sedge fibers. A total of seven plates have been subjected to seven test-shots  using 7.62 mm commercial ammunition. The fibers were embedded under pressure in the epoxy resin matrix and cured at room temperature for 24 hours. The tested specimens were examined by scanning electron microscopy. Besides, analysis of variance (ANOVA) was performed and the absorbed energy of all specimens were evaluated, based on a confidence level of 95%.

A growing demand for research about ballistic armor shields follows the increase of violence around the world. Ultimately, different composite materials with polymeric matrices have already presented the minimum performance as an individual protection required with cheaper and lower density, such as those reinforced with natural lignocellulosic fiber (NLF). The Cyperus malaccensis, a type of sedge fiber, is already used in simple items like ropes, furniture, and paper, but has not yet been investigated as composite reinforcement for possible ballistic protection applications. Therefore, composite plates were prepared for the ballistic tests, based on the condition of 30 vol% sedge fibers coated by graphene oxide. A total of seven plates have been subjected to seven test-shots  using 7.62 mm commercial ammunition. The fibers were embedded under pressure in the epoxy resin matrix and cured at room temperature for 24 hours. The tested specimens were examined by scanning electron microscopy. Besides, analysis of variance (ANOVA) was performed and the absorbed energy of all specimens were evaluated, based on a confidence level of 95%.

A growing demand for research about ballistic armor shields follows the increase of violence around the world. Ultimately, different composite materials with polymeric matrices have already presented the minimum performance as an individual protection required with cheaper and lower density, such as those reinforced with natural lignocellulosic fiber (NLF). The Cyperus malaccensis, a type of sedge fiber, is already used in simple items like ropes, furniture, and paper, but has not yet been investigated as composite reinforcement for possible ballistic protection applications. Therefore, composite plates were prepared for the ballistic tests, one for each condition of 10, 20 and 30 vol% sedge fibers. Each plate has been subjected to 5 test-shots  using 7.62 mm commercial ammunition. The fibers were embedded under pressure in the epoxy resin matrix and cured at room temperature for 24 hours. The tested specimens were examined by scanning electron microscopy. Besides, analysis of variance was performed and the absorbed energy of all specimens were evaluated.

Natural lignocellulosic fibers (NLFs) are increasingly replacing synthetic fibers as reinforcement in polymer matrix composites. This work investigates envira fiber (Bocageopsis multiflora), a lesser-known NLF endemic to the Amazon region, analyzing its physical, thermochemical, morphological, and mechanical properties. Epoxy matrix composites with 10–40 vol% of continuous, aligned envira fibers were produced and characterized via Fourier transform infrared spectroscopy (FTIR) and mechanical testing. Results were statistically evaluated using ANOVA and Tukey’s test. The envira fiber exhibited a density of 0.23 g/cm³, a crystallinity index of 69.5%, and a microfibrillar angle of 7.07°, with thermal stability up to 210°C. FTIR confirmed characteristic NLFs functional groups, while morphological analysis revealed fine fibril bundles and a rough surface. The fiber’s average tensile strength was 62 MPa. Composites showed tensile strength improvements up to 40 vol% fiber content, though flexural strength remained unchanged. Fracture analysis indicated brittle failure. These results demonstrate envira fiber’s potential as a lightweight, cost-effective reinforcement for engineering applications.

The growing impacts of climate change, combined with the high demand for environmentally responsible practices, have encouraged the scientific community and the industrial sector to seek sustainable alternatives for the development of new materials [1]. In this context, natural fiber-reinforced composite materials have emerged as a promising alternative to synthetic composites, not only due to their lower environmental impact but also because they offer economic and functional advantages in various applications [2]. The Amazônica region, rich in plant biodiversity, holds significant potential for the use of fibers extracted from native species in the development of sustainable composites. This contributes to reducing dependence on synthetic materials while also promoting the appreciation of the forest’s natural resources through responsible extractive practices [3]. The incorporation of these natural fibers into materials—especially in the construction sector—represents a significant step forward in the development of sustainable cities, while also promoting the growth of the regional bioeconomy, technological innovation, and local infrastructure [4]. In this study, polyester matrix composite materials reinforced with guaruman fibers were analyzed for their flexural mechanical properties. Test specimens were produced using silicone molds and sanded to meet the specifications of ASTM D790 for flexural strength testing. Specimens were fabricated with 10%, 20%, and 30% guaruman fiber volume fractions in polyester resin. The results were validated through ANOVA statistical variance analysis. The flexural mechanical results indicated a slight increase in the average strength. Regarding the flexural modulus, there was an increase in material stiffness as the fiber content increased. ANOVA indicated no statistically significant differences in the strength results among the composites. Although no significant differences in strength were observed, it is important to highlight the reduction in resin content required to produce composites with 30% fiber volume, without compromising strength.

This study aims to develop a nanocomposite based on recycled polycarbonate (PC) with reduced graphene oxide (rGO), intended for applications in electromagnetic radiation absorbing materials (ERAM), with emphasis on stealth technologies applied to vessels [1]. The nanofibers were produced using the Solution Blow Spinning (SBS) process, aiming to maximize efficiency in electromagnetic radiation absorption [2-4]. The methodology involved the characterization of the individual components (PC and rGO) and the resulting nanocomposite through thermal analyses (DSC and TGA), gel permeation chromatography (GPC) to determine the molar mass of PC, and complementary techniques such as Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), and electromagnetic radiation absorption analysis using a vector network analyzer. The results demonstrated that incorporating different proportions of rGO into the PC significantly enhanced radiation absorption in the X-band, indicating the formation of a promising functional system for electromagnetic shielding applications. The combined analyses revealed a homogeneous morphological structure and suitable thermal and structural properties, confirming the potential of the developed nanocomposite as an efficient alternative for use in defense and security systems [5-6].

This study provides an in-depth review of the electrical properties of composite materials, encompassing metals, ceramics, polymers, and nanocomposites reinforced with nanometric particles. It examines critical electrical characteristics, such as conductivity and dielectric properties, and their implications for diverse applications. The analysis highlights the significant enhancement of electrical conductivity through the incorporation of metallic nanoparticles, which establish conductive networks within polymer matrices. By exploring the interactions between composite constituents, the study elucidates the behavior of these materials under varying conditions, offering valuable insights into their performance. This comprehensive review serves as a foundation for targeted future research, facilitating detailed investigations into specific composite types and their potential limitations. Furthermore, it enriches the existing literature by providing a broad perspective on the electrical properties of composites, paving the way for advancements in fields such as electronics, biomedical devices, and environmental technologies. This work underscores the importance of understanding component interactions to drive innovation and develop novel applications for composite materials.

Given the growing demand for sustainable solutions in pavement engineering, the use of agricultural waste as soil reinforcement material has emerged as a technically and environmentally viable alternative. Among these residues, banana fiber shows high potential due to its low cost and wide availability in tropical regions. This study aims to investigate the potential application of banana fiber as a reinforcement material for soils used in pavement subgrades. Initially, physicochemical analyses were conducted using X-ray diffraction (XRD) and scanning electron microscopy (SEM) on both untreated and chemically treated fibers to assess structural modifications and determine the need for treatment to enhance fiber–soil adhesion. Subsequently, preliminary permanent deformation tests were performed using a repeated load triaxial apparatus to evaluate the effectiveness of the fiber as reinforcement and identify the optimal fiber content that provides the best mechanical performance. The results indicate that banana fiber can significantly improve soil strength and reduce permanent deformations, provided that adequate fiber content is used and, if necessary, the fibers undergo prior treatment. These findings are consistent with results reported in the literature, which highlight improvements in shear strength and bearing capacity of clayey soils through the incorporation of natural fibers (Finu John et al., 2018; Bawadi et al., 2020; Guimarães et al., 2024). This research contributes to the advancement of more sustainable subgrade stabilization techniques, offering both environmental and economic benefits.

Niobium is a strategic material for Brazil, a country that holds the largest global reserves of this element. However, its sintering presents significant challenges, mainly due to the high reactivity of the metal, which promotes oxide formation and hinders consolidation. This study aimed to investigate the feasibility of cold sintering of niobium at different temperatures, seeking to minimize oxidative effects and enable new technological applications. The material used was supplied by CBMM (Companhia Brasileira de Metalurgia e Mineração), and experiments were conducted at temperatures of 125 °C, 150 °C, and 175 °C. To promote the formation of a transient liquid phase, niobium powders were mixed with 10 wt.% of absolute ethanol. Sintering was performed under a simultaneous pressure of 300 MPa, with a holding time of 30 minutes at each specified temperature. After processing, the samples were characterized through density measurements, scanning electron microscopy (SEM), and X-ray diffraction (XRD) analyses. The results indicated that cold sintering of niobium was effective even at the relatively low temperatures employed. XRD analysis revealed only minor peaks corresponding to the NbO phase, indicating a low incidence of oxidation during the process. These findings demonstrate the feasibility of cold sintering pure niobium, paving the way for the development of new components and applications, with advantages in reducing processing temperatures and preserving metallic properties. The use of cold sintering techniques thus represents a promising alternative for processing highly reactive metals such as niobium.

Natural lignocellulosic fibers (NLFs) have been widely studied as sustainable alternatives to synthetic fibers, standing out for being renewable, biodegradable, economically viable and for presenting good specific mechanical properties [1-3]. In this context, the present study aimed to evaluate the flexural strength of polyester matrix composites reinforced with short jute and piassava fibers. The fibers were used in their natural form, without surface treatment, cut to a length of 15 mm, and incorporated into the matrix by manual molding (hand lay-up) using silicone molds, without the application of pressure. The specimens were produced with randomly distributed discontinuous fibers, with mass fractions adjusted to the mold volume. The bending tests indicated that the pure polyester composite presented a bending stress of 112.12 ± 17.58 MPa, while the composites reinforced with jute and piassava fibers reached 59.16 ± 8.37 MPa and 62.48 ± 5.89 MPa, respectively, representing reductions of approximately 47% and 44% in relation to the pure matrix. Fractographic analysis of the rupture surfaces revealed that the failure of the composites was predominantly governed by fiber pull-out and low interfacial adhesion between fiber and matrix, also associated with the presence of internal voids resulting from the manual molding process. These factors contributed to the reduction of the mechanical efficiency of the composites, highlighting the need for surface treatments of the fibers and improvements in processing to optimize structural performance.

Hybrid composites composed of carbon and sisal fibers are gaining prominence due to their ability to balance mechanical performance with sustainability. These materials are particularly promising in structural applications where fracture resistance is a critical design factor. Fracture toughness, which reflects a material’s ability to resist crack propagation, is influenced by the fiber-matrix interface, fiber hybridization strategy, and microstructural parameters. This study presents a review of current methods for characterizing fracture toughness in hybrid composites and explores modelling techniques that predict fracture behavior. Emphasis is placed on the interaction between synthetic (carbon) and natural (sisal) fibers, including how their contrasting properties influence crack deflection, fiber pull-out, and energy absorption mechanisms [1]. Modelling approaches such as finite element analysis and cohesive zone modelling are also discussed, offering insights into the prediction of fracture response under different loading conditions [2]. This work provides a framework for optimizing hybrid fiber composites in applications requiring high fracture resistance with environmental considerations [3].

The growing global demand for product customization, coupled with the long lead times associated with traditional manufacturing processes, has driven the industry to adopt faster and more flexible production methods. In this context, additive manufacturing (AM) — particularly material extrusion-based 3D printing (FFF) — stands out as a technological advancement by enabling the fabrication of customized geometries and multi-material parts with minimal waste. Among the polymers used in AM, polyamides are widely recognized for their mechanical strength, thermal stability, rigidity, and wear resistance. When reinforced with carbon fibers, these properties are significantly enhanced, making nylon-based composites highly suitable for high-performance applications, including in the defense sector. However, the mechanical performance of parts produced via FFF depends directly on process parameters such as extrusion temperature, print speed, and layer thickness, which influence material flow and interlayer adhesion. This study investigates the effects of extrusion speed, nozzle temperature, and infill orientation on the mechanical and thermal behavior of a carbon fiber-reinforced polyamide processed on the Bambulab X1E printer. Tensile and Differential Scanning Calorimetry (DSC) tests were conducted to evaluate the influence of these parameters, and an Analysis of Variance (ANOVA) was applied to validate the statistical significance of the results and support the selection of optimal printing conditions.

This research explores the radiological shielding performance of hybrid composites made from aramid and linen fabrics embedded in an epoxy polymer matrix, reinforced with bismuth oxide (Bi2O3), using Monte Carlo N-Particle (MCNP) simulations. The study aims to assess gamma radiation attenuation by analyzing photon flux across composite layers and energy deposition within the material. The MCNP code was utilized to simulate gamma photon interactions, investigating the effects of Bi2O3 concentration, layer thickness, and fabric arrangement. Bi2O3, known for its high atomic number and density, significantly enhances the composite’s radiation attenuation capabilities while maintaining structural integrity. The results indicate substantial reductions in photon flux and efficient energy absorption, driven by the combined properties of aramid’s mechanical strength, linen’s eco-friendliness, and Bi2O3’s superior radiation-blocking capacity. The simulations highlight how composite design influences shielding effectiveness, providing valuable insights into developing lightweight, durable materials for radiological protection in medical imaging, aerospace, and industrial applications. This work lays the groundwork for experimental validation and optimization of Bi2O3-reinforced hybrid composites, advancing the development of sustainable, high-performance solutions for radiation shielding and contributing to safer and more efficient protective technologies.

Solid solution strengthening is an essential process for increasing the strength of metals. It occurs when solute atoms are introduced into a crystalline matrix [1,4]. The interaction between dislocations and solute atoms — which may occupy interstitial sites or substitute lattice positions — generates distortions that hinder dislocation motion, thus enhancing mechanical resistance [2,5]. Substitutional solutes cause spherical distortions in the lattice, creating compressive or tensile stress fields, while interstitial solutes, due to their smaller size, produce more significant distortions and interact more effectively with dislocations [1,6]. The elastic misfit energy resulting from these distortions is a fundamental component of the strengthening mechanism [4,7]. The mathematical modeling of these interactions allows for the estimation of interaction energy based on elastic theory, taking into account parameters such as solute concentration, atomic radius mismatch, and modulus difference [3,8]. Recent studies emphasize the importance of optimizing the concentration and type of solute atoms, as well as processing conditions such as temperature and strain rate, to maximize the strengthening effect in advanced metallic alloys [5–7].

This study investigated the Cold Sintering Process (CSP) [1] of potassium ferrite, previously synthesized by the sol-gel auto-combustion method. To date, there have been no reported cases of potassium ferrite sintering; therefore, two solutions were tested for transient phase formation: acetic acid at a 5 molar concentration and pure ethanol, both applied at 5 wt% of the sample's weight. After consolidation of the specimens, an average material loss of 20 wt% was observed in both cases. Structural characterization by X-Ray Diffraction (XRD) indicated that the use of acetic acid resulted in a poorly defined crystalline phase, highlighting the inadequacy of this solvent for the studied method, despite achieving bulk formation. On the other hand, the use of ethanol revealed significant microstructural changes, confirmed by Scanning Electron Microscopy (SEM) images. It was observed that the initial microstructure, characterized by typical grains resulting from combustion synthesis, evolved into a lamellar (plate-like) structure [2,3], leading to an improvement in the mechanical strength of the material when compared to specimens produced with acetic acid. These results demonstrate that ethanol is an effective solvent for optimizing the microstructural and mechanical properties of potassium ferrite obtained through cold sintering process.

The growing demand for sustainable solutions in civil construction, particularly in tropical regions facing a shortage of natural aggregates, has encouraged the use of mining waste as an alternative raw material for the production of artificial aggregates (Cabral et al., 2008). This study investigates the mineralogical interactions between sandy and silty textured soils and a clayey mining sludge, subjected to calcination processes aimed at forming reactive phases.

The methodology involved the formulation of mixtures with varying proportions of clayey sludge, subjected to calcination at temperature ranges defined based on mineralogical and thermal analyses. The samples were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA), following established practices for assessing the reactivity of calcined clays (Pinheiro et al., 2023; Monteiro et al., 2004).

Preliminary results indicated the formation of potentially pozzolanic phases, such as amorphous aluminosilicates, at temperatures above 700 °C, corroborating literature findings on the influence of firing temperature on clay activation (da Silva et al., 2015). The microstructure observed via SEM showed good integration between the constituents of the mixtures after calcination, suggesting the feasibility of combining soils and mining residues for pavement applications.        

This study investigates the radiological protection capabilities of hybrid composites composed of aramid and linen fabrics embedded in an epoxy polymer matrix, reinforced with graphene oxide (GO), through Monte Carlo N-Particle (MCNP) simulations. The research focuses on evaluating the attenuation of gamma radiation by analyzing photon flux between composite layers and energy deposition within the material structure. The MCNP code was employed to model the interaction of gamma photons with the hybrid composite, considering variations in GO concentration, layer thickness, and fabric stacking configurations. The incorporation of GO enhances the mechanical and shielding properties of the composite, leveraging its high electron density and dispersion within the epoxy matrix. Results demonstrate significant photon flux reduction and optimized energy absorption, influenced by the synergistic effects of aramid’s high tensile strength, linen’s sustainability, and GO’s radiation interaction capabilities. The simulations reveal the impact of composite design on shielding efficiency, offering insights into lightweight, flexible materials for radiological protection in medical, aerospace, and industrial applications. This work establishes a foundation for experimental validation and further optimization of GO-reinforced hybrid composites, contributing to the development of sustainable and high-performance radiation shielding solutions.

Magnetic hyperthermia-mediated cancer therapy (MHCT) faces challenges related to heat stress response (HSR), hypoxic tumor microenvironments, and insufficient reactive oxygen species (ROS) generation. To address these, we explored novel approaches to improve therapeutic outcomes.

In the first study, we synthesized magnetic nanoparticles (MNPs) with varied morphologies, including spherical, cubical, rod-shaped, and flower-shaped structures, to evaluate their heating efficiencies and therapeutic efficacy. Among them, cubical MNPs exhibited superior heating performance due to magnetosome-like chain formation and sustained drug release, leading to enhanced magneto-chemotherapy in vitro and in vivo.

To target hypoxic tumor cores, we developed self-propelling "nano-bacteriomagnets" (BacMags) by integrating anisotropic magnetic nanocubes into Escherichia coli. This innovative bacterial delivery system achieved efficient MNP transport, resulting in superior hyperthermic performance, 85% pancreatic cancer cell death in vitro, and complete tumor regression in vivo within 30 days.

Further, we investigated heat stress responses in glioma cells post-MHCT under different tumor microenvironment conditions, including 2D monolayers, 3D monoculture spheroids, and coculture spheroids. We observed HSP90 upregulation during treatment, which limited therapeutic efficacy. A combinatorial approach using the HSP90 inhibitor 17-DMAG alongside MHCT significantly enhanced glioma cell death, achieving 65% and 53% tumor inhibition at primary and secondary sites within eight days and complete tumor regression in vivo within 20 days via immune activation.

We also explored magnetothermodynamic (MTD) therapy by combining ROS generation and heat-induced immunological effects using vitamin K3-loaded copper zinc ferrite nanoparticles (Vk3@Si@CuZnIONPs) under an alternating magnetic field (AMF). This dual mechanism resulted in substantial ROS-mediated oxidative damage and immune activation, achieving a 69% tumor inhibition rate in lung adenocarcinoma within 20 days and complete tumor regression by 30 days.

Additionally, metabolic profiling of cancer-derived exosomes using LC-MS/MS and NMR revealed dysregulated metabolic pathways associated with tumor progression. Identifying common metabolites across pancreatic, lung, and glioma cells highlighted potential biomarkers for early detection and therapeutic monitoring.

These synergistic approaches—optimizing MNP designs, employing bacterial delivery systems, inhibiting HSP90, combining ROS-heat mechanisms, and utilizing exosomal metabolites—demonstrate significant advancements in MHCT, paving the way for more effective cancer therapies and improved clinical outcomes.

This work proposes for the first time to develop a nanocomposite from polymethyl methacrylate (PMMA) based microfibers and reduced graphene oxide (rGO), synthesized using the Solution Blow-Spinning (SBS) technique [1]. This technique allows the production of fibers with a small diameter using a thermoplastic polymer, being capable of producing microfibers on a large scale. The interest is related to the reduction of the diameter when compared to conventional fibers, as the diameter size of these materials directly affects their properties, which tend to improve as the contact surface increases, thereby improving wettability [2][3]. The use of graphene and graphene oxide as reinforcing materials in composites has attracted attention, as they tend to provide greater rigidity, strength and conductivity to the material [4]. Graphene oxide is obtained by functionalizing graphene through exfoliation, creating regions with sp2 and sp3 hybridized carbons [5], in addition to hydroxyl and epoxy functional groups. This structure improves the interaction with the polymer matrix, increasing the rigidity of the composite and making it conductive, with the advantage of reducing costs when using reduced graphene oxide (rGO). The results obtained from experimental tests of concentration and morphology through Scanning Electron Microscopy (SEM) during the development of the nanocomposite will indicate the feasibility of producing a pure PMMA nanocomposite (matrix) reinforced with rGO in powder form (filler) for applications such as conductive polymer composites via Solution Blow Spinning.

The design and material selection for fuel rods in Small Modular Reactors (SMRs) play a critical role in ensuring both the neutronic efficiency and thermal safety of the reactor core. This study presents a detailed comparative analysis of the neutronic behavior and heat transfer performance of a standard fuel rod configuration using two distinct cladding materials: Zircaloy-4 and stainless steel. Simulations were conducted using the SCALE code package, employing modules suitable for neutron transport and heat generation modeling under steady-state conditions.The investigation focused on key parameters such as the effective multiplication factor (k-eff), neutron flux distribution, and axial power profile, as well as the impact of cladding material on heat conduction away from the fuel. Zircaloy-4, known for its low neutron absorption cross-section and favorable thermal conductivity, demonstrated higher neutronic reactivity and improved thermal performance compared to stainless steel. However, the use of stainless steel—often considered for its mechanical robustness and corrosion resistance—resulted in increased parasitic neutron absorption and a corresponding decrease in reactivity, requiring compensatory design adjustments.The comparative results underscore the trade-offs inherent in cladding material selection, particularly in advanced reactor systems like SMRs where compact core design and passive safety features are prioritized. The findings contribute to the optimization of fuel design by providing quantitative insights into how material choices affect reactor behavior at both the neutronic and thermal levels. This study supports ongoing efforts in the development of next-generation reactors by highlighting material-performance interdependencies that must be carefully considered during the early stages of reactor design and licensing.

The integration of thorium into uranium dioxide (UO₂) fuel presents a promising strategy to enhance fuel cycle sustainability, reduce long-term radiotoxicity, and improve proliferation resistance in nuclear reactors. This study investigates the neutronic performance of a mixed oxide fuel composed of UO₂ and thorium dioxide (ThO₂) in the context of Small Modular Reactors (SMRs), focusing on both a single fuel rod and a complete fuel assembly configuration. The SCALE simulation suite was employed to model and analyze key neutronic parameters, including effective multiplication factor (k-eff), neutron flux distribution, and isotopic evolution over burnup. The analysis explores various UO₂/ThO₂ ratios, with special attention to the moderation properties, resonance absorption behavior, and the production of fissile ²³³U from thorium. In the single-rod model, the addition of ThO₂ slightly reduces initial reactivity but leads to favorable breeding characteristics due to the generation of ²³³U, which contributes to sustained fission over time. In the full assembly configuration, moderation effects and inter-rod neutron interactions further influence the reactivity trends and spatial flux profiles. Results demonstrate that mixed UO₂/ThO₂ fuel exhibits competitive neutronic behavior when compared to conventional UO₂ fuel, with notable advantages in terms of fissile regeneration and longer fuel cycle potential. Moreover, the thorium content contributes to flattening the power distribution across the assembly, which may reduce localized thermal stresses and improve fuel utilization. These findings highlight the feasibility of incorporating thorium into SMR fuel designs and encourage further investigation into thermo-mechanical performance and reprocessing implications. The study supports the development of advanced fuel cycles aligned with the goals of next-generation reactor technologies.

Natural fiber-reinforced polymer composites have emerged as a sustainable alternative to conventional materials, particularly those utilizing biodegradable thermoplastics. Thermoplastic starch (TPS) is a notable candidate due to its renewability, low cost, and biodegradability; however, its limited mechanical strength necessitates reinforcement for broader applications [1]. Among natural reinforcements, guarumã fiber, derived from the Ischnosiphon koern plant native to the Amazon, offers excellent potential owing to its lightweight nature, mechanical resistance, and ecological appeal [2,3]. This research explores the development of TPS-based composites reinforced with guarumã fibers, aiming to enhance mechanical performance while fostering sustainable material solutions aligned with bioeconomic principles and the valorization of Amazonian biodiversity.

The composites were produced using commercial corn starch plasticized with 30% glycerol, incorporating guarumã fibers processed through peeling and milling to improve interfacial compatibility. Five formulations were prepared via single-screw extrusion, varying fiber content up to 30 wt.%. Standardized hot-pressing techniques were applied to obtain films and specimens, which were subsequently characterized by density, hardness (ASTM D2240), tensile (ASTM D638), and impact testing, alongside SEM and XRD analyses.

The incorporation of guarumã fibers led to notable improvements in tensile strength and modified the composite morphology, as evidenced by SEM, which also revealed satisfactory interfacial adhesion. XRD results indicated semi-crystalline structures influenced by fiber content. These outcomes highlight guarumã fiber as an effective reinforcement for biodegradable TPS composites, supporting their application in sustainable plastic packaging with enhanced mechanical properties and reduced environmental footprint.

Sustainable polymer matrix composites have gained prominence as an eco-friendly alternative to conventional materials, especially those based on biodegradable thermoplastics. Among them, thermoplastic starch (TPS) stands out for its abundance, low cost, and biodegradability, although its mechanical limitations require reinforcement for more demanding applications [1]. In this context, the use of natural fibers emerges as a viable and environmentally responsible solution. Ubim fiber, originating from the Amazon region and extracted from the leaves of the Geonoma baculifera palm, presents itself as a promising reinforcement due to its lightness, strength, and renewability [2,3]. This study investigates the potential of TPS composites reinforced with ubim fibers, aiming to improve mechanical properties and promote materials aligned with the bioeconomy and the valorization of sustainable Amazonian forest resources.

For composite production, commercial corn starch plasticized with 30% glycerol was used. Ubim fibers were sourced from the local market in Belém (PA) and subjected to peeling and milling processes to optimize adhesion to the polymer matrix. The composites were processed using a single-screw extruder in five TPS/fiber ratios (0, 5, 10 and 15 wt.%). Films and test specimens were molded by hot pressing under standardized parameters. The composites were characterized through density, hardness (ASTM D2240), tensile strength (ASTM D638), and impact tests, as well as microstructural analyses by scanning electron microscopy (SEM) and phase evaluation by X-ray diffraction (XRD).

The results showed that the addition of ubim fibers to the thermoplastic starch composites significantly increased tensile strength, demonstrating the effectiveness of natural reinforcement in enhancing the mechanical properties of the polymer matrix. SEM analyses revealed morphological changes, highlighting good interfacial adhesion between the ubim fibers and TPS, which is essential for efficient stress transfer. XRD indicated the presence of semi-crystalline structures influenced by fiber incorporation. These findings confirm that the use of natural fibers, such as ubim, is a promising strategy for developing biodegradable composites with improved performance. Such materials exhibit high potential for sustainable plastic packaging applications, combining mechanical performance with reduced environmental impact.

The shortage of natural aggregates in tropical regions has driven the development of alternative materials for road infrastructure applications. Among these, artificial aggregates produced through clay calcination have been investigated for their mechanical properties and pozzolanic reactivity potential (Cabral, 2008; da Silva et al., 2015; Friber et al., 2023). This study proposes the production of artificial aggregates from soil–waste mixtures, incorporating a clay-rich mining sludge, aiming to add value to mineral waste and reduce reliance on conventional materials.

The formulations were defined based on preliminary mineralogical analyses using X-ray diffraction (XRD) and scanning electron microscopy (SEM), with the objective of identifying the phases formed and microstructural changes induced by calcination (Monteiro et al., 2004; Pinheiro et al., 2023). The calcination temperature was selected to maximize the formation of amorphous cementitious phases. After calcination, the aggregates were used to mold cylindrical specimens using split molds, which were then subjected to repeated load triaxial tests to determine the resilient modulus—a key parameter for assessing the mechanical performance of materials used in pavement base and subbase layers.

Initial results indicated that the artificial aggregate exhibits elastic behavior compatible with that of traditional pavement materials, reinforcing its potential as a technically and environmentally sustainable solution.

Fuel cladding and encapsulation materials are fundamental to the structural integrity, thermal management, and neutronic performance of nuclear fuel assemblies. This study proposes the use of a hybrid composite material based on Zircaloy-4 reinforced with silicon carbide (SiC) for the encapsulation of UO₂ fuel pellets, aiming to enhance both the thermal and mechanical properties of the fuel system while maintaining favorable neutronic characteristics. The proposed Zircaloy-4/SiC composite is evaluated and compared with conventional metallic cladding materials, such as standard Zircaloy-4 and stainless steel, as well as ceramic encapsulants like stabilized zirconia (ZrO₂).The analysis considers key parameters including thermal conductivity, neutron absorption cross-section under normal and transient operating conditions. Simulations conducted using the SCALE code system assess the impact of the composite on reactivity, heat distribution, and fuel temperature profiles. Preliminary results indicate that the inclusion of SiC enhances the high-temperature performance of the cladding, while the Zircaloy-4 matrix preserves the low neutron absorption desirable for maintaining core reactivity. When compared to zirconia, the Zircaloy-4/SiC composite offers superior thermal conductivity and reduced swelling under irradiation, albeit with slightly higher neutron absorption. Nonetheless, the composite exhibits a balanced profile that combines the structural advantages of ceramics with the neutronic compatibility of metallic alloys. These findings support the viability of metal-matrix composite encapsulation as a promising pathway for accident-tolerant fuel (ATF) designs in advanced reactor systems, including SMRs and Generation IV concepts. Further experimental validation is recommended to confirm fabrication feasibility and in-reactor behavior.

This research investigates the radiological protection properties of composite materials comprising aramid and linen fabrics integrated within an epoxy matrix through advanced computational simulations. The study focuses on assessing the efficacy of these composites in attenuating gamma radiation, with specific emphasis on measuring the photon flux between layers and the energy deposition within the material structure. Utilizing Monte Carlo simulation techniques, the interaction of gamma photons with the composite layers was modeled, accounting for variations in layer thickness, material density, and stacking configurations. The simulations provide detailed data on the attenuation coefficients and energy absorption profiles, enabling a comprehensive evaluation of the shielding performance. The choice of aramid and linen fabrics, combined with the epoxy matrix, aims to balance lightweight and flexible characteristics with robust radiation protection, offering potential applications in medical imaging, aerospace radiation shielding, and industrial safety equipment. Preliminary results indicate that the hybrid composite structure exhibits promising attenuation capabilities, with the layering sequence and material composition significantly influencing the reduction of photon flux and energy deposition. These findings contribute to the development of sustainable, high-performance radiological protection materials, paving the way for further experimental validation and optimization of composite designs for real-world applications.

This study investigates the interaction of radiation with two-dimensional (2D) materials, including graphene, graphene oxide (GO), hexagonal boron nitride (hBN), and molybdenum diselenide (MoSe₂), to assess their potential in radiation sensor development. Using Monte Carlo N-Particle (MCNP5) simulations with 10⁷ to 10⁸ events, the research evaluates the materials’ responses to photons, neutrons, and charged particles, focusing on energy deposition and interaction efficiency. For photons, MoSe₂ exhibited superior interaction at low energies, while graphene showed limited absorption, particularly at higher energies. GO displayed moderate efficiency at intermediate energies, and hBN’s interaction increased with photon energy. In stacked configurations, MoSe₂ maintained high energy deposition, with other materials showing distinct low-energy behaviors. For neutrons, graphene exhibited minimal response across all energies, whereas MoSe₂ and hBN demonstrated robust interactions, especially at medium to high energies. hBN excelled in thermal neutron absorption, while MoSe₂ was more effective at higher neutron energies. Charged particle interactions mirrored these trends, with MoSe₂ leading in high-energy absorption and graphene, GO, and hBN offering balanced responses at lower energies. These findings highlight MoSe₂ and hBN as promising candidates for radiation sensors in neutron-rich and high-energy environments, while graphene and GO are better suited for moderate-energy applications, paving the way for tailored sensor designs.

This study evaluates the radiological shielding performance of hybrid composites comprising aramid and fique fabrics embedded in an epoxy polymer matrix, reinforced with silicon carbide (SiC), through Monte Carlo N-Particle (MCNP) simulations. The research focuses on assessing the attenuation of both gamma radiation and neutrons by analyzing photon and neutron flux across composite layers and energy deposition within the material structure. The MCNP code was employed to model the interactions of gamma photons and neutrons with the composite, exploring variations in SiC concentration, layer thickness, and fabric stacking configurations. SiC, valued for its high density and neutron absorption capabilities, enhances the composite’s shielding efficiency while maintaining mechanical robustness. The results demonstrate significant reductions in gamma photon and neutron flux, with optimized energy absorption driven by the synergistic effects of aramid’s tensile strength, fique’s sustainable properties, and SiC’s superior radiation interaction characteristics. The simulations reveal the influence of composite design on dual-protection effectiveness, offering insights into lightweight, eco-friendly materials for radiological shielding in medical, nuclear, and aerospace applications. This work establishes a foundation for experimental validation and further optimization of SiC-reinforced hybrid composites, advancing sustainable, high-performance solutions for comprehensive radiation protection.

Among numerous natural lignocellulosic fibers (NLFs), kenaf fiber has been extensively studied for applications in textiles, construction materials, and furniture due to its long history of cultivation worldwide. This work presents, for the first time, a comparison of static and dynamic Izod impact toughness in kenaf fiber-reinforced composites. The area under the stress-strain curve revealed a static toughness of 52.30 kJ/m² for the 30 vol% kenaf fiber composite, which is approximately 12 times higher than that of the neat epoxy matrix. In Izod impact tests, the absorbed energy reached 38.8 kJ/m² for the 30 vol% kenaf fiber composite, corresponding to 22 times the energy absorption of the neat epoxy. The average tensile toughness values were found to be superior to the corresponding dynamic impact toughness values. Scanning electron microscopy (SEM) analysis elucidated the fracture mechanisms and highlighted the influence of reinforcing fibers under the two toughness conditions investigated in this study.

Potassium ferrite was synthesized through the sol-gel auto-combustion [1] chemical route, aiming to evaluate the influence of calcination temperature on the formation of crystalline phases. The obtained samples were subjected to calcination temperatures of 0°C (post-combustion), 300°C, 550°C, 750°C, and 950°C. Structural characterizations were performed using X-Ray Diffraction (XRD), where the crystallite size was calculated from the most intense peak at each calcination temperature using the Scherrer equation [2]. Micrographs were also obtained to assess grain size, along with analyses by Mössbauer Spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), and Raman Spectroscopy. The results demonstrated that the synthesis of potassium ferrite was successful; however, an increasing formation of additional phases of potassium ferrite and magnetite was observed with rising calcination temperatures. Therefore, it is concluded that the sol-gel auto-combustion method is not recommended for applications requiring a specific crystalline phase predominance, due to the simultaneous generation of secondary phases with higher thermal treatment temperatures [3]. Additionally, as the temperature increased, a reduction in grain size was observed, attributed to the combustion of residual fuel traces.

This study developed lightweight, cost-effective ballistic shields using epoxy composites reinforced with short babassu fibers (Attalea speciosa). Composites with 10-30 vol.% fiber content were fabricated via compression molding and characterized for chemical, thermal, and ballistic properties through Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and 9 mm projectile ballistic tests. FTIR revealed interfacial matrix-fiber interactions, evidenced by intensified 1608cm⁻¹ bands, while TGA showed 6% reduced thermal stability in 10 vol.% composites (due to fiber degradation), this effect diminished at higher fractions. Ballistic tests indicated absorbed energy decreased from 230 J (10 vol.%) to 212 J (30 vol.%), with failure mechanisms shifting from matrix fracture to interfacial debonding. Notably, 30 vol.% composites maintained structural integrity after five impacts.  Cost analysis showed the 30 vol.% composite was 98% cheaper than A500 steel and 82% cheaper than commercial polyethylene armor. These results position babassu fibers as a sustainable, economical reinforcement for ballistic applications, offering significant cost savings without substantial performance compromise.