Search Results (712)

This study presents a hybrid computational investigation into the radiation shielding behavior of Fe-enriched Al-based alloys (Al-Fe-Mo-Si-Zr) for potential use in nuclear applications. Four alloy compositions with varying Fe contents (7.21, 6.35, 5.47, and 4.58 wt%) were analyzed using a combination of Monte Carlo simulations, machine learning (ML) predictions based on multilayer perceptrons (MLPs), EpiXS, and SRIM-based charged particle transport modeling. Key photon interaction parameters—including mass attenuation coefficient (MAC), half-value layer (HVL), buildup factors, and effective atomic number (Z_eff)—were calculated across a wide energy range (0.015–15 MeV). Results showed that the 7.21Fe alloy exhibited a maximum MAC of 12 cm²/g at low energies and an HVL of 0.19 cm at 0.02 MeV, indicating improved gamma attenuation with increasing Fe content. The ML model accurately predicted MAC values in agreement with Monte Carlo and XCOM data, validating the applicability of AI-assisted modeling in material evaluation. SRIM calculations demonstrated enhanced charged particle shielding: the projected range of 10 MeV protons decreased from ~55 µm (low Fe) to ~50 µm (high Fe), while alpha particle penetration reduced accordingly. In terms of fast neutron attenuation, the 7.21Fe alloy reached a maximum removal cross-section (Σ_R) of 0.08164 cm⁻¹, showing performance comparable to conventional materials like concrete. Overall, the results confirm that Fe-rich Al-based alloys offer a desirable balance of lightweight design, structural stability, and dual-function radiation shielding, making them strong candidates for next-generation protective systems in high-radiation environments. Full article

Limnospira spp., commercially known as spirulina, is widely recognized for its remarkable benefits due to its rich composition of bioactive compounds like phycobiliproteins, carotenoids, and phenolic compounds. These natural bioactive compounds not only serve as colorants but also offer potent antioxidant, anti-inflammatory, immunomodulatory, anticancer, antimicrobial, and anti-aging properties. As a result, spirulina and its components are increasingly used in cosmetic formulations to promote skin hydration, reduce wrinkles, and protect against UV radiation damage. Its bioactive components enhance fibroblast growth, boost collagen production, and prevent premature skin aging by inhibiting enzymes responsible for elastin degradation. Additionally, spirulina-based cosmetics have demonstrated wound-healing properties without genotoxic effects, with formulations containing C-phycocyanin particularly effective in shielding skin cells from UV-induced apoptosis. Despite these well-established benefits, there remains significant potential for the cosmetic industry to harness spirulina’s capabilities further. Research into the molecular mechanisms underlying its bioactive compounds in cosmetic formulations is still in its early stages, offering many opportunities for innovation. Emerging fields of biotechnology, such as nanotechnology and biocosmetics, could enhance the stability, efficacy, and delivery of spirulina-based ingredients, unlocking new possibilities for skin protection and rejuvenation. Furthermore, its proven biological properties align perfectly with the increasing consumer demand for safe, sustainable, and nature-inspired skincare solutions. Full article

As space missions become increasingly complex, protection against high-energy charged particles has emerged as a critical factor for the safe operation of spacecraft. These electrical particles, including protons and electrons, can penetrate spacecraft structures and cause severe damage to internal components. Therefore, this review discusses the characteristics of the high-energy charged particle environment in Earth orbits. Accordingly, various passive shielding materials have been evaluated, highlighting their advantages, disadvantages, and applicability in different orbital environments. Specifically, the importance of optimizing shielding materials and structures to enhance the radiation resistance of spacecraft has been emphasized. Furthermore, advancements in passive shielding materials for high-energy charged particles in Earth orbit over the past few years have been examined. Finally, future research directions have been proposed, including the development of lighter and more efficient shielding materials, the optimization of multi-layer shielding structures, and the integration of passive shielding with other protective technologies. Full article

This study employs simulation tools to design and evaluate lightweight, lead-free polymer composites incorporating polytetrafluoroethylene (PTFE), polyethylene (PE), and polyetherimide (PEI) for gamma radiation shielding in nuclear medicine. Targeting clinically relevant photon energies from Tc-99m (140 keV), I-131 (364 keV), and Cs-137 (662 keV), composites’ structural and shielding performance with Bi₂O₃ and WO₃ was assessed using XCOM and Phy-X/PSD. PEI emerged as the most suitable polymer for load-bearing and thermally exposed applications, offering superior mechanical stability and dimensional integrity. Bi₂O₃-WO₃ fillers for Tc-99m achieved a ~7000-fold increase in MAC, I-131 ~2063-fold, and Cs-137 ~1370-fold compared to PbO₂. The PEI-75Bi₂O₃-25WO₃ achieved a ~21-fold reduction in half-value layer (HVL) compared to lead for Tc-99m. For higher-energy isotopes of I-131 and Cs-137, HVL reductions of ~0.44-fold and ~0.08-fold, respectively, were achieved. The results demonstrate that high-Z dual filler polymer composites have an equal or enhanced attenuation properties to lead-based shielding, whilst also enhancing the polymer composites’ mechanical and thermal characteristics. As the use of ionizing radiation increases, so does the potential risks; high-Z dual filler polymer composites provide a sustainable, lightweight, non-toxic alternative to conventional lead shielding. Full article

This study discusses how cultural interpretations of the foster parent role might shape perceptions and practices related to the temporariness of care and reunification with biological families. Employing a contrastive-comparative approach, the study compares interviews with seven Japanese foster parents, with prevailing discourses surrounding the foster parent role in Norway. The findings suggest that the Japanese foster parents implicitly recognize the temporariness of their role. In contrast, the Norwegian foster parent role has typically been associated with an emphasis on the risks associated with separation from new attachment figures, which may be perceived as detrimental to children’s well-being. We argue that this conceptualization, which frames children as inherently vulnerable, may shape the foster parent’s role as one of protection, with a primary focus on shielding the child from disruption and fostering a secure attachment. This perspective, we suggest, could have implications for the temporariness of children’s care placements and the process of reunification. The study calls for a critical examination of the values underlying current child protection practices and encourages openness to alternative perspectives, including those informed by different cultural contexts. Full article

One of the most researched minerals in terms of how to produce it and the range of uses for it is calcium carbonate. This work describes how to generate hybrid materials by co-precipitating calcium carbonate loaded with either bis-dehydroxycurcumin (CCOH) or the calcium complex of bis-dehydroxycurcumin (Ca(CCOH)₂). Composite materials with various morphologies were produced when calcium carbonate and different amounts of curcumin derivatives were precipitated in alcoholic media. Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) were used for structural and morphologic characterization of the materials, while thermal stability was verified by thermal-gravimetric analysis (TGA), and porosity analysis was performed to evaluate surfaces and pore sizes. The hybrid materials were embedded in a cosmetic matrix lacking a sun protective effect in order to assess the UV-shielding properties. The transmittance spectra were subsequently measured in the 290–400 nm region, and the sun protection factor (SPF) was calculated. Thus, the co-precipitation approach produced hybrid materials loaded with curcumin derivatives, which were further evaluated for possible applications in the medical field for the delivery of drugs or in skincare products. Full article

Lysine carboxymethyl cysteinate (LCC) is a synthetic substance obtained via lysine salification of S-carboxymethyl-cysteine. LCC has emerged as a promising glutathione (GSH) precursor. In this study, we sought to determine whether LCC could boost GSH levels and protect skin against oxidative stress. Experiments utilizing primary human keratinocytes and skin tissue samples revealed that LCC significantly increased endogenous GSH levels. LCC was able to pass through the stratum corneum and reach deep into the epidermis, where it enhanced the production of key metabolites involved in GSH biosynthesis. Then, the efficacy of LCC on skin protection was explored. LCC demonstrated protective effects by shielding keratinocytes from blue-light-induced oxidative stress and preventing ultraviolet B (UVB)-induced barrier disruption and pigmentation in a pigmented living skin equivalent (pLSE) model. In addition to its antioxidant properties, LCC also reduced the production of inflammatory mediators. Together, these findings underscore the multifaceted role of LCC in bolstering the natural antioxidant defenses of skin and preventing the accumulation of irreversible damage from the environment, thereby positioning it as a promising candidate for advancing skin health. Full article

Blockchain technology uses a consensus mechanism to create and finalize blocks. The consensus mechanism affects the total performance parameters of the blockchain network, such as throughput. In this paper, we present “Nazfast”, a simplified proof of stake—Byzantine fault tolerance based consensus mechanism to create and finalize blocks. The presented consensus is completed in multiple folds. For block producer and validation committee selection, we used a secure and speeded-up election mechanism, S&Sem, in Nazfast. The consensus is designed for fast block finalization in a malicious environment. The simulation result shows that we approximately achieved three block finalizations in 1 s with almost similar latency. We reduced and fixed the number of validators in the consensus to improve the throughput. We achieved a higher throughput among other consensus of the same family. Because we reduced the number of validators, the safety parameters of the consensus are at risk, so we used Sea Shield to improve the overall consensus safety. This is another blockchain to save nodes’ details when they join/unjoin the network as validators. By using all three parts together, our system is protected from 28-plus different attacks, and we maintain a high decentralization by using S&Sem. Finally, we also enhance the incentive mechanism of consensus to improve the liveness of the network. Full article

Protective garments for the medical radiation shielding of healthcare professionals must ensure flexibility and shielding performance. As such, process technologies for density enhancement are required when manufacturing shielding sheets to ensure the reproducibility of flexibility and shielding performance. Although previous efforts commonly reduced particle size to minimize porosity, nanoparticle production cost is significant. Therefore, this study aimed to improve the density of the shielding sheet by controlling the spacing between internal particles. The proposed improvement method is based on polydisperse particle packing. Particle sizes can be adjusted using process techniques such as sintering, pressing, and mixing. The study materials used are tungsten and bismuth oxide (eco-friendly alternatives to lead), with polyethylene as the polymer matrix. First, the shielding performance improved by 4% in the sintering process when the tungsten content reached 90 weight percent (wt%). The solvent removal process, used to eliminate the solvent added for polymer utilization, increased the density by 13.18%; however, it was lower than that of the compression process. The shielding performance improved by approximately 10% in the compression molding process when the tungsten content was 90 wt%. This study confirms that optimizing density enhancement strategies for radiation shielding materials can significantly improve shielding performance. Full article

Energy-selective surfaces (ESSs) have gained attention as an advanced electromagnetic protection technology. This review discusses the evolution of ESSs, focusing on four key areas: frequency bandwidth expansion, material innovations, functional enhancements, and application diversification. ESSs have evolved from narrowband designs to providing ultra-wideband protection, covering L-band to K-band frequencies. New designs, including non-reciprocal mechanisms and cascaded filters, enhance the shielding efficiency. Material advancements like the use of vanadium dioxide (VO₂) and micro–nano fabrication techniques have reduced costs and improved performance, enabling higher-frequency applications. Future developments aim to overcome the current limitations, offering a broader bandwidth, higher power tolerance, and faster response times. ESSs play a key role in integrated electromagnetic protection systems. Full article

In both fundamental and applied scientific exploration, nanostructured protective materials have garnered substantial interest owing to their multifaceted utilization in the fields of medicine, pharmaceuticals, and electronics, among others. This study investigated the evolution of cutting-edge materials for electromagnetic radiation attenuation, with a specific emphasis on the incorporation of superparamagnetic magnetite nanoparticles, Fe₃O₄, into composite systems. The nanoparticles were generated through chemical condensation, meticulously adjusting the proportions of iron salts, specifically FeSO₄·7H₂O and FeCl₃·6H₂O, in conjunction with a 25% aqueous solution of ammonia, NH₄OH·H₂O. This study examined the intricate details of the crystalline structure, the precise composition of phases, and the intricate physicochemical attributes of these synthesized Fe₃O₄ nanoparticles. The analysis was conducted employing a suite of advanced techniques, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and energy-dispersive analysis (EDAX). The key findings of this research suggest that the magnetic nanoparticles generated through chemical condensation have an average size between 10 and 11 nm. This size was determined using BET surface area measurements, which were precise to within 0.1 nm. Moreover, this study demonstrated that incorporating superparamagnetic nanoparticles into composite materials significantly reduces microwave radiation. In particular, an optimal concentration of 0.25% by weight leads to a maximum decrease of 21.7 dB in cement specimens measuring 10 mm in thickness. Moreover, a critical threshold concentration of 0.5 weight percent is established, beyond which the interactions of nanoparticles inhibit the process of remagnetization. These investigations demonstrate that it is feasible to pursue a route towards the development of highly effective electromagnetic shielding materials tailored to specific requirements for diverse applications. Full article

Wool textiles with multifunctional properties such as self-cleaning, antibacterial, electrical conductivity, UV blocking etc. have recently attracted interest. Among the materials employed towards their development, carbon nanotubes (CNTs) have been widely investigated due to their unique chemical, mechanical and electrical properties, exhibiting also notable UV-blocking properties. However, their limited dispersibility in solvents, particularly in water, has hindered their extensive industrial application and diminished their significant potential. In this work, two guanidinylated derivatives of hyperbranched polyethyleneimine (GPEI5k and PEI 25K) functionalized oxCNTs (oxCNTs@GPEI5K and oxCNTs@GPEI5K), with exceptional aqueous compatibility and colloidal stability, developed in our recent publication, were evaluated as to their antibacterial activity on Gram (-) Escherichia coli and Gram (+) Staphylococcus aureus bacteria and their cytotoxicity against mammalian cells, and the most promising, i.e., oxCNTs@GPEI5K, was subsequently used as finishing agent of wool fabric. The resulting wool textiles were evaluated for color, wash fastness, antibacterial properties, and UV-blocking performance. The GPEI-functionalized oxCNTs derivative, exhibited uniform distribution and good adhesion onto the wool fabrics yielding multifunctional wool fabrics with sustained antibacterial properties even after multiple washing cycles. Additionally, the modified textiles exhibited improved ultraviolet protection, highlighting their potential for multifunctional applications in antibacterial and UV-shielding textiles. Full article

Magnesium–lithium alloys, currently the lightest metallic structural materials, exhibit exceptional specific strength, superior damping capacity, and remarkable electromagnetic shielding properties. These characteristics endow them with significant potential for engineering applications in automotive, aerospace, satellite, and military industries. However, their poor corrosion resistance severely restricts practical implementation. This review systematically examines recent advances in surface engineering techniques for magnesium–lithium alloys, with a focus on corrosion protection strategies. Key approaches are critically analyzed, including chemical conversion coatings, electroless plating, anodization, and advanced coating technologies. Furthermore, emerging hybrid methods combining multiple surface treatments are highlighted. Finally, future research directions are proposed to address existing challenges in surface protection of magnesium–lithium alloys. Full article

Electric vehicles have garnered substantial attention as an environmentally sustainable transportation alternative amid escalating global concerns regarding ecological preservation and energy resource management. While the proliferation of electric vehicles necessitates the development of efficient and secure charging infrastructure, the inherent communication-intensive nature of the charging processes has raised concerns regarding potential privacy vulnerabilities. Our paper introduces a privacy protection scheme specifically designed for electric vehicle charging reservations to address this issue. The primary goal of this scheme is to protect user privacy while maintaining operational efficiency and economic viability for charging providers. Our proposed solution ensures a secure and private environment for charging reservation transactions and subsequent deviation settlements by incorporating advanced technologies, including zero-knowledge proof, a consortium blockchain, and homomorphic encryption. The scheme encrypts charging reservation information and securely transmits it via a consortium blockchain, effectively shielding the sensitive data of all participating parties. Notably, the experimental findings establish the robustness of our scheme in terms of its security and privacy protection, aligning with the stringent demands of electric vehicle charging operations. Full article

Biofilms formation by the Burkholderia cepacia complex (Bcc) poses a considerable risk to hospital environments, particularly for immunocompromised individuals. These bacteria exhibit notable resistance to disinfectants and antibiotics, mainly due to their ability to adhere to biotic and abiotic surfaces, forming highly persistent biofilms, contamination, and pharmaceutical solutions. These microbial structures function as protective shields, impeding the effective action of antimicrobial compounds and facilitating the occurrence of chronic infections and outbreaks in healthcare settings. The high genetic plasticity of the Bcc, evidenced by the presence of multiple chromosomes and the ease of horizontal gene transfer, further enhances its capacity for adaptation and treatment resistance. Moreover, the ability of the Bcc to survive in aquatic environments and withstand unfavorable conditions heightens concerns regarding the contamination of pharmaceutical products. This study examines the molecular mechanisms underlying Bcc biofilm formation, its impact on hospital infections, and the challenges associated with its eradication. It also discusses the current detection techniques available and innovative approaches to mitigating contamination in pharmaceutical products. In summary, a thorough understanding of the mechanisms underlying Bcc biofilm formation and maintenance is crucial for implementing more effective preventive measures and minimizing the risks associated with hospital infections. Full article