Search Results (786)

In this work, the microstructure and mechanical properties of the FeAlCrNiV complex concentrated alloy (CCA) were studied in the as-cast and annealed states. The material was annealed at 800 °C for 16 days to test microstructure stability and phase evolution. It was found that the microstructure does not differ in the two investigated states, and the results of differential scanning calorimetry and dilatometry showed that there is almost no difference in the thermal response between the as-cast and annealed states. Both investigated states exhibit eutectic structure with bcc solid solution and ordered phase with B2 symmetry. In a single grain, several regions with B2 laths in the bcc matrix were observed. Inside the B2 laths and in the bcc matrix, bcc spheres and B2 spheres were observed, respectively. All three features—laths, matrix and spheres—are fully crystallographically coherent. Nevertheless, in the adjacent region in the grain, the crystal structure of the matrix, laths and sphere changed to the other structure, i.e., the characteristics of the microstructure feature with B2 symmetry changed to bcc, and vice versa. Compression deformation tests were performed for various temperatures from room temperature to 800 °C. The results showed that the material exhibits exceptional yield stress values, especially at high temperatures (820 MPa/800 °C), and excellent plasticity (25%). Full article

An anion exchange-assisted technique was used for the synthesis of platinum-decorated SnO₂ supports, providing nanocatalysts with enhanced activity for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). In this study, a series of SnO₂ supports, namely SnA (synthesized almost at room temperature), SnB (hydrothermally treated at 180 °C), and SnC (annealed at 600 °C), are systematically investigated, all loaded with 1 mol% Pt from H₂PtCl₆ under identical mild conditions. The chloride ions from the SnCl₄ precursors were efficiently removed via a strong-base anion exchange reaction, resulting in highly dispersed, crystalline ~5 nm cassiterite SnO₂ particles. All Pt/SnO₂ composites displayed mesoporous structures with type IVa isotherms and H₂-type hysteresis, with SP1a (Pt on SnA) exhibiting the largest surface area (122.6 m²/g) and the smallest pores (~3.5 nm). STEM-HAADF imaging revealed well-dispersed PtOx domains (~0.85 nm), while XPS confirmed the dominant Pt⁴⁺ and Pt²⁺ species, with ~25% Pt⁰ likely resulting from photoreduction and/or interactions with Sn–OH surface groups. Raman spectroscopy revealed three new bands (260–360 cm⁻¹) that were clearly visible in the sample with 10 mol% Pt and were due to the vibrational modes of the PtOx species and Pt-Cl bonds introduced due the addition and hydrolysis of H₂PtCl₆ precursor. TGA/DSC analysis revealed the highest mass loss for SP1a (~7.3%), confirming the strong hydration of the PtOx domains. Despite the predominance of oxidized PtOx species, SP1a exhibited the highest catalytic activity (k_app = 1.27 × 10⁻² s⁻¹) and retained 84.5% activity for the reduction of 4-NP to 4-AP after 10 cycles. This chloride-free low-temperature synthesis route offers a promising and generalizable strategy for the preparation of noble metal-based nanocatalysts on oxide supports with high catalytic activity and reusability. Full article

Arbuscular mycorrhizal (AM) fungi (AMF) form a symbiotic association with terrestrial plants and increase growth and productivity. The relationships between the growth of centipedegrass (CG) and AMF are not well understood. We monitored the growth and AM colonization of CG growing on the four slopes (north, east, south, and west) of a pasture, to obtain information on aspect differences in the soil chemical properties–grass–AMF association. Soil properties almost always varied between the slope aspects. The total soil N, C, EC, and moisture tended to be highest on the northern aspect, whereas the soil available P and pH tended to be highest on the western and southern aspects, respectively. Despite the aspect differences in the microclimate and soil properties, CG grew well in all aspects, showing similar dry matter weights (DMW) for the fouraspects. Furthermore, the AM colonization of CG, in any characteristic structures (internal hyphae, vesicles, and arbuscules), was not significantly different between the slope aspects on most measurement occasions, although the colonization usually varied between the seasons and years. There were no relationships between the DMW and AM characteristic structure colonization and between the DMW and soil chemical properties. However, the colonization of the arbuscules and vesicles of the CG had a correlation with some soil chemical properties. The results suggest that AM colonization on CG growing in a hill pasture did not differ between the slope aspects. This may be a factor contributing to the high adaptability of the grass to all slope aspects. Full article

In the present study, the coaxial waterjet-assisted nanosecond laser drilling of micro-holes in C_f/SiC composites, coupled with nanosecond laser drilling in air for fabricating micro-holes with high aspect ratios, were investigated. The surface morphology, reaction products, and micro-hole shapes were thoroughly examined. The results reveal that, for the coaxial waterjet-assisted nanosecond laser drilling of micro-holes in the C_f/SiC composite, the increasing of waterjet velocity enhances the material removal rate and micro-hole depth, but reduces the micro-hole diameter and taper angle. The coaxial waterjet isolates the laser-ablated region and cools down the corresponding region rapidly, leading to the formation of a mixture of SiC, SiO₂, and Si on the surface. As the coaxial waterjet velocity increases, the morphology of residual surface products changes from a net-like structure to individual spheres. Coaxial waterjet-assisted nanosecond laser drilling, with a waterjet velocity of 9.61 m/s, achieves micro-holes with a good balance between efficiency and quality. For the fabrication of micro-holes with a high aspect ratio in C_f/SiC composites, micro-holes fabricated by nanosecond laser drilling in air exhibit obvious taper features, which should be ascribed to the combined effects of spattering slag, plasma, and energy dissipation. The application of coaxial waterjet-assisted nanosecond laser drilling on micro-holes fabricated by laser drilling in air effectively expands the hole diameter. The fabricated micro-holes have very small taper angles, with clean wall surfaces and almost no reaction products. This approach, combining nanosecond laser drilling in air followed by coaxial waterjet-assisted nanosecond laser drilling, offers a promising technique for fabricating high-quality micro-holes with high aspect ratios in C_f/SiC composites. Full article

The oxidative degradation of anthocyanins in red wine was investigated under controlled conditions using hydroxyl radicals generated in the presence of Cu (II) as a catalyst. A full factorial experimental design with 23 replicates was used to evaluate the effects of hydrogen peroxide concentration, catalyst dosage, and reaction temperature on anthocyanin degradation over a fixed time. Statistical analysis (ANOVA and multiple regression) showed that all three variables and the main interactions significantly affected anthocyanin loss, with temperature identified as the most influential factor. The combined effects were described by a first-order polynomial model. The activation energies for degradation ranged from 56.62 kJ/mol (cyanidin-3-O-glucoside) to 40.58 kJ/mol (peonidin-3-O-glucoside acetate). Increasing the temperature from 30 °C to 40 °C accelerated the degradation kinetics, almost doubled the rate constants and shortened the half-life of the pigments. At 40 °C, the half-lives ranged from 62.3 min to 154.0 min, depending on the anthocyanin structure. These results contribute to a deeper understanding of the stability of anthocyanins in red wine under oxidative stress and provide insights into the chemical behavior of derived pigments. The results are of practical importance for both oenology and viticulture and support efforts to improve the color stability of wine and extend the shelf life of grape-based products. Full article

This work presents a comprehensive evaluation of the heat-sealability of films developed from chañar brea gum (CBG), a biopolymer with potential for packaging applications. Heat sealability is a critical property in the packaging industry, as it directly determines the integrity and functionality of the final product. The films were prepared by the 10% casting method with the addition of glycerin, and heat sealing was performed at 140 °C using a heat sealer. Heat sealing was performed on 2 cm × 10 cm strips of chañar gum in the horizontal (CBG-H) and vertical (CBG-V) directions. This study employs a joint determination to explore the fundamental properties of the films, including proximate analysis, antioxidant capacity, FTIR, DSC, TGA-DTGA, XRD, mechanical testing, water vapor permeability, sorption, and biodegradability. By integrating the results of all these determinations, this study seeks to evaluate and explain the “intimate relationships”—i.e., the complex interconnections among the molecular structure, composition, thermal behavior, mechanical properties, and barrier properties of channier gum films—and how these fundamental properties dictate and control their heat sealability. The thermal stability of CBG is up to 200 °C, with a melting point of 152.48 °C. The interstrand spacing was very similar at 4.88 nm for CBG and 4.66 nm for CBG-H. The SEM images of the heat seal show rounded shapes on the surface, while in the cross section, it is homogeneous and almost without gaps. The WVP decreased from 1.7 to 0.37 for CBG and CBG-H, respectively. The Young’s modulus decreased from 132 MPa for CBG to 96.5 MPa for CBG-H. The heat sealability is 656 N/m, with a biodegradability of 4 days. This comprehensive approach is crucial for optimizing the sealing process and designing functional and efficient biodegradable packages. Full article

Significant morphological transformations resulting from open-pit mining activities always present major problems with site safety and slope stability. This study investigates an active marble quarry in Dinar, Türkiye by combining geospatial analysis and photogrammetry based on unmanned aerial vehicles (UAV). Acquired in 2024 and 2025, high-resolution images were combined with dense point clouds produced by Structure from Motion (SfM) methods. Iterative Closest Point (ICP) registration (RMSE = 2.09 cm) and Multiscale Model-to-Model Cloud Comparison (M3C2) analysis was used to quantify the surface changes. The study found a volumetric increase of 7744.04 m³ in the dump zones accompanied by an excavation loss of 8359.72 m³, so producing a net difference of almost 615.68 m³. Surface risk factors were evaluated holistically using a variety of morphometric criteria. These measures covered surface variation in several respects: their degree of homogeneity, presence of any unevenness or texture, verticality, planarity, and linearity. Surface variation > 0.20, roughness > 0.15, and verticality > 0.25 help one to identify zones of increased instability. Point cloud modeling derived from UAVs and GIS-based spatial analysis were integrated to show that morphological anomalies are spatially correlated with possible failure zones. Full article

The study of the processes of low-temperature synthesis of one-dimensional particles, which are the basis for two- and three-dimensional structures, is relevant for materials science. The modified metal-stimulated electrochemical etching method made it possible to synthesize silicon nanowires with an average thickness of about 292.6 nm. Scanning electron microscopy has shown the formation of nanowires, flower-like structures, and clusters of matter after the deposition of zinc oxide on the porous surface. The hexagonal structure of ZnO crystallites was determined by X-ray diffraction spectroscopy. Studies of the initial sample by electron paramagnetic resonance (EPR) spectroscopy revealed a narrow signal in the center of the spectrum. The subtraction of the EPR spectra with a sequential increase in microwave power up to 8 mW shows the absence of saturation of the signal. This indicates an almost free flow of charges through the surface nanostructures under the influence of an external field. Heat treatment in an air atmosphere at 300 °C caused a significant increase in the intensity of the EPR spectrum. This led to an increase in the intensity of charge transfer through paramagnetic centers. Full article

The poor interfacial adhesion between ductile gold (Au) electrodes and polydimethylsiloxane (PDMS) substrates affects their application in flexible sensors. Here, a porous Au electrode is designed and combined with a flexible PDMS substrate to form a structure that embeds Au into the PDMS film, thereby enhancing the interfacial adhesion of the Au/PDMS electrode. The resistivity change of the Au/PDMS electrode is only 12.3% after 100 tape peeling trials. The resistance of the Au/PDMS electrode remains stable at the 30% strain level after 2000 tensile cycling tests. This feature is mainly attributed to the deformation buffering effect of the porous Au film. After 100 min of ultrasonic oscillation testing, the resistivity change of the Au/PDMS electrode remains stable. It is also shown that the Au/PDMS electrode has excellent interfacial adhesion properties, which is mainly attributed to the interlocking effect of the Au/PDMS electrode structure. In addition, the temperature coefficient of resistance (TCR) of the temperature sensor based on the Au/PDMS electrode is approximately 0.00320/°C and the sensor’s sensitivity remains almost stable after 200 temperature measurement cycles. Au/PDMS electrodes have great potential for a wide range of applications in flexible electronics due to their excellent interfacial adhesion and electrical stability. Full article

Cytochrome c (Cytc) is a multifunctional protein, essential for respiration and intrinsic apoptosis. Post-translational modifications of Cytc have been linked to physiological and pathophysiologic conditions, including cancer. Cytc tyrosine 67 (Y67) is a conserved residue that is important to the structure and function of Cytc. We here report the phosphorylation of Y67 of Cytc purified from bovine heart mapped by mass spectrometry. We characterized the functional effects of Y67 Cytc modification using in vitro and cell culture models. Y67 was mutated to the phosphomimetic glutamate (Y67E) and to phenylalanyl (Y67F) as a control. The phosphomimetic Y67E Cytc inhibited cytochrome c oxidase (COX) activity, redirecting energy metabolism toward glycolysis, and decreased the pro-apoptotic capabilities of Cytc. The phosphomimetic Y67E Cytc showed a significantly impaired rate of superoxide scavenging and a reduced rate of oxidation by hydrogen peroxide, suggesting a lower ability to transfer electrons and scavenge reactive oxygen species (ROS). Phosphomimetic Y67E replacement led to an almost complete loss of cardiolipin peroxidase activity, pointing to a central role of Y67 for this catalytic function of Cytc. In intact cells, phosphomimetic replacement leads to a reduction in cell respiration, mitochondrial membrane potential, and ROS levels. We propose that Y67 phosphorylation is cardioprotective and promotes cell survival. Full article

Glycans on the surface of all immune cells are the product of diverse post-translational modifications (glycosylation) that affect almost all proteins and possess enormous structural heterogeneity. Their bioinformational content is decoded by glycan-binding proteins (lectins, GBPs), such as C-type lectins, including selectins, galectins, and Siglecs. Glycans located on the surface of immune cells are involved in many immunological processes through interactions with GBPs. Lectins recognize changes in the glycan epitopes; distinguish among host (self), microbial (non-self), and tumor (modified self) antigens; and consequently regulate immune responses. Understanding GBP–glycan interactions accelerates the development of glycan-targeted therapeutics in severe diseases, including inflammatory and autoimmune diseases and cancer. This review will discuss N- and O-glycosylations and glycosyltransferases involved in the biosynthesis of carbohydrate epitopes and address how interactions between glycan epitopes and GBPs are crucial in immune responses. The pivotal role of the glycan antigen tetrasaccharide sialyl Lewis x in mediating immune and tumor cell trafficking into the extravascular site will be discussed. Next, the role of glycans in modulating bacterial, fungal, viral, and parasitic infections and cancer will be surveyed. Finally, the role of glycosylation in antibodies and carbohydrate vaccines will be analyzed. Full article

In this study, phosphogypsum waste collected from a factory dump in Kedainiai, Lithuania, was used for the first time as a starting material in the dissolution–precipitation synthesis of high-quality bioceramic calcium hydroxyapatite (Ca₁₀(PO₄)₆(OH)₂; CHA). The CHA powders were synthesized using the dissolution–precipitation method, employing phosphogypsum in four different conditions: untreated, dried at 100 °C, dried at 150 °C, and annealed at 1000 °C. Various phosphorus sources were used in the CHA synthesis process: Na₂HPO₄; a mixture of Na₂HPO₄ and NaH₂PO₄; or a combination of Na₂HPO₄, NaH₂PO₄, and NaHCO₃. These mixtures were allowed to react at 80 °C for 48 h, 96 h, 144 h, and 192 h. X-ray diffraction (XRD) analysis revealed slight variations in the synthesized products depending on the specific starting materials used. Fourier transform infrared spectroscopy (FTIR) was conducted to confirm the structural characteristics of the synthesized CHA samples. The surface microstructure of the synthesized CHA samples differed notably from that of the raw phosphogypsum. All synthesized CHA samples exhibited Type IV nitrogen adsorption–desorption isotherms with H3-type hysteresis loops, indicating the presence of mesoporous structures, typically associated with slit-like pores or aggregates of plate-like particles. To the best of our knowledge, an almost monophasic CHA has been fabricated from phosphogypsum waste for the first time using a newly developed dissolution–precipitation synthesis method. A key challenge in the high-end market is the development of alternative synthesis technologies that are not only more environmentally friendly but also highly efficient. These findings demonstrate that phosphogypsum is a viable and sustainable raw material for CHA synthesis, with promising applications in the medical field, including the production of artificial bone implants. Full article

The drilling machinability of glass fiber G₁₄, basalt fiber B₁₄, and two hybrid laminates (B₄G₆B₄, G₄B₆G₄) was evaluated through 36 full-factorial experiments employing an HSS-G drill, three spindle speeds (715, 1520, 3030 rpm), and three feed rates (0.1–0.3 mm rev⁻¹). Peak thrust force varied from 65.8 N for B14 at 0.1 mm rev⁻¹ to 174.3 N for G₁₄ at 0.3 mm rev⁻¹; hybrids occupied the intermediate range of 101–163 N. Infra-red thermography recorded maximum drill temperatures of 110–120 °C for G₁₄, almost double those of B₁₄, while both hybrids attenuated hotspots to below 90 °C. ANOVA attributed 73.4% of thrust force variance to feed rate, with material type and spindle speed contributing 15.5% and 1.7%, respectively; for temperature, material type governed 41.5% of variability versus 17.0% for speed. Dimensional quality tests revealed that the symmetric hybrid G₄B₆G₄ maintained entrance and exit diameters within ±2% of the nominal 6 mm, whereas B₄G₆B₄ over-expansion exceeded 8% at the lowest feed and G₁₄ exit diameters grew to 6.1 mm at 0.3 mm rev⁻¹. Integrating basalt compliance with glass stiffness, therefore, halves thrust force relative to G₁₄, suppresses delamination and overheating, and offers a practical strategy to prolong tool life and improve hole quality in multi-material composite structures. These insights guide parameter selection for lightweight hybrid composites in aerospace, renewable-energy installations, and marine components worldwide. Full article

An elastic bandage or tensor bandage is widely known as a flexible medical device made of polymer materials. It is usually made of cotton and reinforced with elastic yarns. Depending on the therapy and clinical picture, elastic bandages are used for compression treatment and as support bandages. The aim of this work was to carry out a washing process and investigate its influence on the physical–mechanical properties of elastic bandages. The washing process was carried out at 40 °C with 25, 50, 60, and 70 wash cycles using Autowash 311L. The elastic bandages were subjected to a tensile load. The tensile strength, elongation, elasticity, and structural properties of the elastic bandages were determined. The results of the elongation show that the values increase with the wash cycles (in standard soap) and decrease after 70 cycles (in standard soap without phosphate). The tensile strength values are highest after 25 wash cycles. The results of the cyclic elasticity measurements show that the elastic bandages do not lose their elongation properties after the first cycle. After the second to fifth cycle, the samples do not return to their original or almost original dimensions when the tensile load is stopped. In addition, an analysis of the data from the 3D leg scanning and an approximation of the compression of the bandages was performed. The circularity and compression values after 60 washes remain within the limits in which the compression bandage can fulfill the compression function. Full article

This work addresses enhancing flow boiling heat transfer via the use of engineered surfaces possessing specific novel geometries created via femtosecond laser texturing. Surface functionalization can result in improved, more controlled, and denser nucleation as well as controlled surface rewetting, leading to reduced incipient superheats, higher heat transfer coefficients, reduced flow instabilities, and increased critical heat fluxes with respect to a non-modified reference surface. Specifically, this study investigates how bubble dynamics and heat transfer performance are affected by three different surface textures fabricated on 200 µm thick 316L stainless steel foils using a femtosecond (fs) laser. The examined textures consist of inclined (=45°) microgrooves, inclined (=45°) conical microholes, and laser-induced periodic surface structures (LIPSSs). Each textured surface’s degree of heat transfer enhancement is assessed with respect to a plain reference surface in identical operating conditions. The working fluid is PP1, a replacement of 3M™ FC-72 in heat transfer applications. Among the tested surfaces, submicron-scale LIPSSs contribute to the rewetting of the surface but only show a slight improvement when not combined with bigger microscale structures. The inclined grooves result in the most gradual onset, showing almost no incipient overshoot. The inclined conical microholes achieve superior results, improving heat transfer coefficients up to 70% and reducing the incipient temperature up to 13.5 °C over a plain reference surface. Full article