This study evaluated the reliability of relative translucency parameter (RTP00) and whiteness index (WID) measurements of single-shade and multi-shade resin composites (RCs) with different thicknesses using a spectrophotometer and a mobile colorimeter application. A total of 192 specimens were prepared from six RCs, including three single-shade and three multi-shade materials, with 1 mm and 2 mm thicknesses. Color measurements were performed at baseline and after 7 days using a spectrophotometer and a mobile colorimeter application. RTP00 values were calculated using the CIEDE2000 formula, and WID values were calculated using the CIELAB-based formula. Reliability was assessed using intraclass correlation coefficients, and data were analyzed with robust ANOVA. Single-shade RCs showed higher RTP00 and WID values than multi-shade RCs. ColorMeter values were higher than spectrophotometer values. Material and method effects were significant for ΔRTP00 and ΔWID, with interactions. Reliability analysis showed higher consistency for the spectrophotometer. Mobile colorimeters provide practical and cost-effective measurements, while spectrophotometers remain a more reliable option for precise color assessment. Material type, thickness, and measurement method should be considered when evaluating optical properties for clinical use.
Friction Stir Spot Welding (FSSW) is a solid-state route for joining dissimilar aluminum-copper assemblies, but welding-induced softening and the brittle Al-Cu intermetallic layer limit joint reliability. This work investigates the integrated use of FSSW and Laser Shock Peening (LSP) as a post-weld surface treatment for 3 mm thick AA6061-T6/pure copper lap joints. A Taguchi L9 array with ANOVA was used to optimize rotational speed, dwell time, and tool geometry, identifying tool shape as the dominant factor; the optimum joint was then treated by LSP with a Q-switched Nd:YAG laser and compared with the as-welded baseline. The joint exhibited an asymmetric response: the aluminum side recovered its HAZ softening and exceeded its base-metal hardness, while the copper side softened slightly through laser-induced thermal recovery, yet the joint showed a net strengthening. XRD and FTIR supported grain refinement and the absence of thermal-oxidation damage. The integrated FSSW + LSP route is thus proposed as a viable post-weld strengthening strategy for thick dissimilar Al/Cu joints.
This study explores the fusion of traditional dyeing and weaving art of the Hainan Li nationality with modern textile design using a deep learning–based style transfer approach. The objective is to develop a reliable digital method for preserving traditional textile patterns while supporting sustainable and efficient design applications. Image data of traditional Li patterns and contemporary textile designs were systematically collected and processed to ensure cultural authenticity and visual diversity, forming a high-quality image dataset. A deep learning style transfer model based on adaptive feature transfer and hierarchical fusion (AFTH) was developed to integrate traditional dyeing and weaving patterns with modern textile design. Experimental results indicate that the proposed method demonstrates improved performance in pattern structure preservation, style representation accuracy, and overall visual quality when compared with representative existing methods. In addition, this study incorporates intelligent wastewater treatment and environmentally friendly dyeing technologies to evaluate the environmental and economic benefits of sustainable textile production. By combining machine learning–based process optimization with intelligent sewage treatment systems, resource consumption, chemical usage, and pollutant emissions are effectively reduced. The integrated results demonstrate that digital design innovation and intelligent environmental management can be jointly promoted within the textile industry.
To address the challenge of broadband noise control in electric vehicle doors under the constraints of narrow installation space and lightweight design, this study focuses on unreinforced glass fiber-melamine foam (GF-MF) composites and systematically investigates their acoustic performance regulation mechanisms and engineering structural design for vehicle door applications. Combining the Transfer Matrix Method (TMM) with impedance tube experiments, the effects of porosity, air backing layer thickness, and flow resistivity on the acoustic coefficients of the material were analyzed. A hybrid Finite Element-Statistical Energy Analysis (FE-SEA) model was established to evaluate the sound transmission loss (STL) of five door composite layup schemes under diffuse incidence conditions. The results demonstrate that high porosity significantly optimizes the impedance matching characteristics in the mid-to-high frequency range and enhances broadband sound absorption efficiency, while high flow resistivity effectively strengthens the viscous dissipation capacity in the mid-to-low frequency range. Among all structural layup schemes, the pure air layer scheme yields the highest STL across the full frequency band. Adding a 2 mm viscoelastic damping layer on the outer door panel side further improves low-frequency sound insulation performance. In contrast, positioning the damping layer adjacent to the GF-MF side or adopting a honeycomb sandwich structure leads to acoustic performance degradation. This research elucidates the acoustic parameter regulation laws of glass fiber-melamine foam (GF-MF) composites and the optimization strategies for vehicle door layup designs. A systematic comparative analysis of five layup schemes under identical thickness constraints is conducted. The findings provide practical engineering guidance for the development of lightweight, thickness-constrained acoustic packages in electric vehicle door systems.
The increasing demand for lightweight and sustainable materials in the automotive sector has intensified research on hybrid natural-synthetic fiber composites. In this study, teak wood dust was explored as an eco-friendly particulate reinforcement for glass fiber/epoxy laminates to enhance structural performance while reducing material cost and environmental impact. The objective was to evaluate how different teak dust loadings (3, 6, and 12 wt.%) influence the mechanical, morphological, and water-resistance characteristics of the resulting hybrid composites. Composite laminates were fabricated using the hand lay-up process, where teak dust was dispersed in an epoxy matrix (10:1 resin-hardener ratio) and sandwiched between glass fabric layers. Specimens were prepared according to ASTM standards and subjected to tensile, flexural, impact, and water absorption tests. The 12 wt.% teak-reinforced composite exhibited the highest tensile strength (45.50 ± 5 MPa), flexural strength (116.24 ± 2 MPa), impact resistance (4.1 ± 1.5 J), and lowest water absorption (5.22 %), correlating strongly with improved matrix adhesion and uniform morphology. These results demonstrate that teak dust significantly enhances interfacial bonding and mechanical reliability, making the 12 % hybrid composite a promising candidate for lightweight automotive components.
Lead-free solder alloys are crucial in the electronics production sector due to environmental and health concerns. While tin aluminum alloys are good alternatives, the addition of indium improves their properties. This study investigates the effect of indium addition on the structural, thermal, and electrical properties of tin aluminum alloys. Sn95-xAl5Inx alloys (where x = 5, 10, and 15 wt.%) were made, and examined using X-ray diffraction, scanning electron microscopy and differential scanning calorimetry. The mechanical, electrical and thermal properties were measured. The addition of indium caused changes in the microstructure and the formation of intermetallic compounds. The Vickers hardness increased from 36.43 kg/mm² for Sn95Al5 alloys to 38.92 kg/mm² for Sn80Al5In15 alloys, while the modulus of elasticity increased from 31.71 GPa to 37.92 GPa with increasing indium content. The melting temperature decreased by up to 130 °C, while mechanical strength and hardness varied with indium content. Electrical resistivity showed variations depending on indium concentration as well. This work is notable for investigating the change in electrical resistivity with varying indium content, highlighting the important role of indium in modifying these properties. The results demonstrate that tin-aluminum-indium alloys exhibit modified melting points and improved mechanical properties, suggesting their potential use in lead-free welding applications and improved welding efficiency.
The results of the investigation of the anodic behavior of the influence of AlFe5Si10 aluminum alloy (Al+5%Fe+10%Si) with potassium in a NaCl solution medium are presented. The studies were carried out by the potentiostatic method in potentiodynamic mode with a potential sweep rate of 2 mV/s. The addition of potassium to the AlFe5Si10 alloy amounted to 0.05-1.0% (wt.). The studies showed that over time the free corrosion potential of the alloys shifts in the positive direction and, with an increase in the concentration of the potassium addition in the AlFe5Si10 alloy, acquires a positive value. An increase in the corrosion rate of the alloys regardless of their composition is noted as a function of the NaCl concentration in the solution. An increase in the concentration of chloride ion in the NaCl solution leads to a decrease in the free corrosion, repassivation, and pitting formation potentials of the alloys. The addition of potassium to the AlFe5Si10 alloy increases its corrosion resistance by 20-25%.
The relationship between the temperature intervals of martensitic transformations, including pre-martensitic phenomena, and the magnitude of superelastic deformation in Ti-18Zr-15Nb shape memory alloy was investigated by the method of electrical resistance measurement, for the implementation of which an original setup was assembled. It is shown that the search for conditions for the realization of maximum superelastic reversible deformation cannot be based solely on the temperatures Mн or Aкˈ.
The development of new biocompatible osseointegrable materials for bone tissue restoration is a relevant task of modern biomaterials science. In the present work, a study of the influence of strontium-, magnesium-, and barium-substituted low-temperature hydroxyapatite (HAP) on the functional activity of human innate immunity cells - monocytes and macrophages - in vitro was carried out. By the methods of X-ray phase analysis and scanning electron microscopy, it was established that the hydroxyapatite powders obtained by doping with strontium, magnesium, and barium cations represent monodisperse particles with sizes of 50-70 мm. The incorporation of Mg2+, Sr2+, and Ba2+ cations into the crystal lattice at a calculated concentration of 10% (mol.) did not lead to significant changes in the morphology and size of the crystallites. It is shown that all the materials under investigation did not exhibit cytotoxicity with respect to monocytes and macrophages. However, their modulating influence on intracellular processes was revealed: all samples significantly reduced the content of acidic compartments (lysosomes) in monocytes and, to a lesser extent, in macrophages. The obtained data indicate that the biological response to calcium phosphate materials is determined not only by the cell type, but also by the structural features of crystals modified by ionic doping, which opens up prospects for targeted design of materials with specified immunomodulating properties for regenerative medicine.
A simple and workable method for manufacturing a miniature thin-walled lattice structure from (Gd,Y)₃Al₂Ga₃O₁₂:Ce ceramics using 3D printing with digital light processing (DLP) is proposed. It is shown that the shrinkage anisotropy arising during polymerization of the composite, burnout, and sintering of the ceramics can be compensated by optimizing the geometry of the initial computer model. High precision of the manufactured product and its conformity to the model geometry can be achieved by selecting the manufacturing conditions, primarily exposure time and print layer thickness. The results of optical and scanning electron microscopy confirm the obtaining of defect-free translucent dense ceramics of high structural perfection. Using inexpensive and publicly available equipment, a structural element (hole in a plate) with a diameter of less than 100 мm was achieved.
The interaction of microchannel biomorphic scaffolds based on gray alder (Alnus incana) with Sn-Hf melts at temperatures from 950 to 1200 °C in vacuum was investigated. It is shown that upon contact of the biomorphic carbon scaffold with the melt, infiltration of the melt into the sample occurs. The infiltration depth depends on the process temperature and can reach ~17 mm upon holding for one week. The microstructure of the obtained materials and their phase composition were investigated. It is shown that the main products of interaction of the melt with carbon are hafnium carbide (HfC) and MAX-phase Hf-SnC. A qualitative model describing the processes of growth of HfC and Hf-SnC compounds on the carbon walls of the microchannels is proposed.
A methodology for nephelometric determination of chlorides in ammonia-thiosulfate solutions has been developed, allowing the analysis of small sample volumes (0.1-2 ml) in the concentration range 0.01-100 g/l. A method for removing interfering thiosulfate ions by treatment of samples with concentrated HNO₃ with subsequent separation of sulfur is proposed. The methodology has been verified on model solutions by the "added-found" method and shows good convergence with titrimetry. The proposed methodology will provide new data on the composition and stability of silver chloride complexes in hydrothermal fluids.
At present, one of the relevant and actively developing directions of medical materials science is the creation of bioresorbable implants used for the restoration of bone defects. This requires materials with sufficiently high mechanical properties and a controlled corrosion rate. An alternative to the widely known magnesium alloys for bioresorbable implants are zinc alloys. Zn alloys exhibit optimal corrosion resistance for use as a material for the manufacture of bioresorbable implants. However, zinc alloys are less studied and have low mechanical properties. In the present work, studies of the influence of severe plastic deformation by the ECAP-Conform method on the structure and mechanical properties of zinc alloy Zn-0.8Li were carried out. As a result of deformation, the structural constituents were refined. The structure in the longitudinal cross-section of the ECAP-Conform rod differs noticeably from the structure in the transverse cross-section, which determines the strong anisotropy of mechanical properties. In the transverse cross-section, the structure of the LiZn₄ phase matrix with inclusions of Zn-LiZn₄ eutectic globules is observed, whereas a banded structure is observed in the longitudinal cross-section. As a result, the rod in the longitudinal cross-section demonstrates record values of strength characteristics for the alloy (yield strength and ultimate tensile strength amounted to 580 and 520 MPa, respectively) and high plasticity of 43%, while samples in the transverse cross-section failed in a brittle manner.
Based on the presented data of experimental studies, the main advantages of the use of microwave radiation energy in technological processes associated with heat treatment of dielectric materials are shown. In addition to ensuring environmental cleanliness and energy efficiency, the introduction of microwave technologies in a number of cases promotes the obtaining of products possessing higher physical and mechanical characteristics. The introduction into production of high-productivity installations equipped with modern microwave energy sources determines the prospects for further development of microwave technologies.
The mechanisms of formation and degradation of the hybrid scintillation composite «polystyrene/LaBr₃(Ce)» are investigated taking into account the influence of atmospheric humidity, which in this case is very significant due to the strong hygroscopicity of lanthanum bromide. Structural changes at all stages of the process have been systematized by methods of X-ray phase analysis, X-ray luminescence, IR spectroscopy, scanning electron microscopy, and optical microscopy. Analysis of stationary and pulsed X-ray luminescence revealed a decrease in scintillation efficiency by 60-80%, caused by degradation of the luminescence centers LaBr₃(Ce). To suppress hydration, a method for removing water from the composite by application of an electric field (10 kV/cm) is proposed, leading to the electrochemical synthesis of moisture-resistant lanthanum oxybromide (LaOBr).
It is proposed to form coatings based on intermetallic alloys of the copper-magnesium system by liquid-phase spreading of magnesium over copper. The influence of process temperature and the nature of activating fluxes on the chemical, phase composition, structure, and hardness of the coatings is established.
The mechanism of silicide formation in a mixture of elements with atomic composition CrSi₂ was studied both directly in the drum of a planetary mill and during subsequent rapid heating in an improvised differential thermal analysis (DTA) setup. It is shown that mechanical treatment reduces the temperature of silicide formation during annealing of the charge by hundreds of degrees, but at the same time significantly deprives the charge of its energy “reserve” if it is intended for preparation for self-propagating high-temperature synthesis (SHS), since significant silicide formation already occurs during milling.In this case, the preliminary mechanical activation time should not exceed 10-15 min. Thermal effects in milled mixtures measured using DTA and differential scanning calorimetry (DSC) setups are consistent with the content of CrSi₂ formed in situ in the mill drum and determined by X-ray analysis. In the case of independent SHS, the preliminary mechanical activation time should be increased to 45 min, but when external heating is applied, it can be limited to 15-20 min.
Breast cancer occupies leading positions in morbidity and mortality among women, and its incidence continues to increase. According to the literature, by 2050 every twentieth woman will face this disease. One of the predictors of breast cancer is a change in tissue stiffness. In this regard, the study of elastic and hyperelastic properties of tissues is highly informative for successful diagnosis and treatment of oncological and other diseases of this organ. In addition, information on breast stiffness is necessary when selecting substitute materials for various reconstructive interventions during removal, resizing, or reshaping of the breast. This paper considers the modeling of fibroglandular breast tissue using Mooney-Rivlin hyperelastic models; their parameters were calculated, and the accuracy and stability of the models, as well as the behavior of elastic moduli, were investigated. It was established that in terms of fitting experimental data, the 9-parameter model best describes the experimental results (SD = 1.97·10⁻5 MPa, δ = 0.50%, R = 0.99999). The initial Young's modulus E₀ was 0.024, 0.023, 0.012, and 0.017 MPa for the 2-, 3-, 5-, and 9-parameter models, respectively, which in the last three cases does not contradict literature data; the average modulus Eavg is 27.97-34.09 kPa and weakly depends on the number of model parameters.
This paper considers materials based on polycrystalline cubic boron nitride (PcBN) with binder components in the Ti(C,N)-Al system. Cutting tools were produced from the obtained composite material and coated with an AlTiN physical vapor deposition (PVD) coating. The structure of coated and uncoated materials was analyzed using scanning electron microscopy (SEM). Comparative tests for hardness and longitudinal finishing turning were carried out.
This work is dedicated to determining the values of the creep threshold and break creep strength through mathematical processing of experimental data. In the approximation used, these mechanical characteristics are treated as unknown material parameters, to be computed by minimizing the total error. Two magnesium alloys, Mg-5.42Al-0.28Mn and Mg-4.98Al-1.72Ca, were studied, revealing a strengthening effect on the creep threshold and break creep strength due to the addition of 1.72 wt% Ca.
