Search Results (5,446)

In the presented research, aluminum-doped zinc oxide (AZO) thin films were synthesized on high-power transmission lines using the RF magnetron sputtering process. The impact of deposition power (160 W to 280 W) and deposition pressure (2 Pa to 5 Pa), on key characteristics like material composition, wettability, anti-icing behavior, and average crystal size were analyzed. The optimization of wettability and anti-icing performance was carried out using two-factor, four-level design of the Taguchi method to study the combined effects of multiple parameters rather than the effect of a single parameter. Considerable variation in the water contact angle, from 92.3° to 123.6°, has been observed, suggesting an enhancement in hydrophobic nature with optimized condition. Anti-icing tests demonstrated that the coated surface delayed ice accumulation by approximately 4.56 times compared to the uncoated surface. X-ray diffraction (XRD) analysis was carried out to confirm notable changes in the intensity of the (002) peak along the c-axis, directly correlating with grain size modification. The change in surface roughness was studied using AFM and the results were compared to establish a relationship between surface roughness and average grain size. Overall, the findings highlight the critical role of deposition parameters and their interactions in modifying the surface and structural properties of AZO thin films, which demonstrates their potential application for improving the anti-icing performance of transmission lines. Full article

Rock art in the Albarracín Cultural Park represents one of Spain’s most significant concentrations of post-Paleolithic paintings, yet comprehensive chemical characterization across multiple shelters remained lacking. This study analyzes 102 pigment samples (54 white, 31 black, 17 red) from 12 shelters using portable X-ray fluorescence spectroscopy. Centered log-ratio transformation addressed compositional data constraints, enabling multivariate analyses (PCA, LDA, MANOVA) that properly account for the constant-sum constraint inherent in geochemical data. Linear discriminant analysis achieved 92.6%–100% classification accuracy for site attribution, with barium emerging as the universal discriminating element across all pigment types (Cohen’s d = 4.91–9.19). Iron concentrations confirmed hematite/goethite use in red pigments, with inter-shelter variations suggesting different ochre sources. Black pigments revealed dual technologies: manganese oxides (pyrolusite) and carbon-based materials, with phosphorus enrichment in some samples consistent with possible bone-derived materials, though alternative phosphorus sources cannot be definitively excluded. This technological duality occurred within individual shelters, documenting greater complexity than previously recognized. White pigments combined substrate-derived materials with gypsum and aluminosilicate clay minerals (likely of the kaolinite group), occasionally incorporating phosphate-rich phases. The documented coexistence of compositionally distinct pigments within single shelters (whether from different raw material sources or varied preparation techniques) confirms the technical heterogeneity of Albarracín rock art and challenges assumptions about technological homogeneity in Levantine art production. This interplay between natural geological constraints and cultural technological choices underscores the need for complementary surface-sensitive techniques to fully resolve the technological repertoire of Levantine artists. Full article

To reveal its influence on quasicrystal structure analysis, multiple diffraction effects in a basic Co-rich decagonal Al-Co-Ni quasicrystal have been investigated in-house and with synchrotron radiation. Two weak reflections were chosen as the main reflections in the in-house measurements, and 40° $\psi$-scans of one main reflection have been performed with synchrotron radiation. As well as being known for periodic crystals and the icosahedral quasicrystal, it is also observed for this decagonal quasicrystal that the intensity of the main reflection may significantly increase if the simultaneous and the coupling reflections are both strong. The occurrence of multiple diffraction events during collection of a full data set as well as the $\psi$-scans measurements have been studied based on an average structure model and the kinematical multiple diffraction theory. The present experimental and simulation efforts on the effects of multiple diffraction suggest that it is insufficient on its own to explain the discrepancy in weak-reflection intensities; alternative explanations like the phasonic disorder should be paid more attention in future. Full article

Divalent europium complexes have attracted significant attention in various fields due to the unique electronic configuration of the Eu(II) ion. Given the high sensitivity of the 5d → 4f emission of Eu(II) ions to the ligand field, it is crucial to explore the relationship between ligands and this emission in Eu(II) complexes. However, the heavy-atom effects on the 5d → 4f emission of Eu(II) complexes coordinated with non-metal elements in the same group remain unclear. In this study, five mononuclear Eu(II)-chalcogenide complexes, Eu[H₃B·EPh-κE,H,H]₂(DME)₂ (E = S for 1 and Se for 2; DME = 1,2-Dimethoxyethane) and Eu[EPh]₂(18-C-6) (E = S for 3, Se for 4, and Te for 5; 18-C-6 = 1,4,7,10,13,16-Hexaoxacyclooctadecane), were synthesized via reduction of diphenyl disulfide chalcogenide analogs with Eu(BH₄)₂(THF)₂ or NaH. The structures of these complexes were investigated by single-crystal X-ray diffraction, and their properties were characterized by thermogravimetric analysis and photophysical property tests. Complexes 1 and 2 are isomorphous and show similar yellowish-green luminescence, while complexes 3–5 have similar structures but crystallize in different space groups with bluish-green luminescence. This research reveals the influence of chalcogenide ligands on the 5d → 4f emission of Eu(II) complexes, providing a theoretical basis and new research ideas for the application of Eu(II) complexes in various fields, including luminescent materials, cryogenic refrigerants, and magnetic materials. Full article

Transparent conductive materials (TCMs) are essential for optoelectrical devices ranging from smart windows and defogging films to soft sensors, display technologies, and flexible electronics. Materials, such as indium tin oxide (ITO) and silver nanowires (AgNWs), are commonly used and offer high optical transmittance and electrical conductivity, but suffer from brittleness, oxidation susceptibility, and require high-cost materials, greatly limiting their use. Carbon nanotube (CNT) networks provide a promising alternative, featuring mechanical compliance, chemical robustness, and scalable processing. This study reports an aqueous ink formulation composed of ultra-long mix-walled carbon nanotubes (UL-CNTs), compatible with the flow coating process, yielding uniform transparent conductive films (TCFs) on polyethylene terephthalate (PET), glass, and polycarbonate (PC). The resulting films exhibit tunable transmittance (85%–88% for single layers; ~57% for three layers at 550 nm) and sheet resistance of 7.5 kΩ/□ to 1.5 kΩ/□ accordingly. These TCFs maintain stable sheet resistance for over 5000 bending cycles and show excellent mechanical durability with negligible effects on heating performance. Post-deposition treatments, including nitric acid vapor doping or flash photonic heating (FPH), further reduce sheet resistance by up to 80% (7.5 kΩ/□ to 1.2 kΩ/□). X-ray photoelectron spectroscopy (XPS) results in reduced surface oxygen content after FPH. The photonic-treated heaters attain ~100 °C within 20 s at 100 V. This scalable, water-based process provides a pathway toward low-cost, flexible, and stretchable devices in a variety of fields, including printed electronics, optoelectronics, and thermal actuators. Full article

A review of studies has shown that aromatic azo and hydrazo derivatives are used in a wide spectrum of fields, including food, pharmaceutical, and cosmetic products, as well as in technical and electronic technologies, which has contributed to the development of new such compounds. In this work, the structures of newly obtained 4-methyl-3,5-dinitro-2-(2-phenylhydrazinyl)pyridine (4MDNPHP) and its azo derivative, 4-methyl-3,5-dinitro-2-[(E)-phenyldiazenyl]pyridine (4MDNPAP), were established by spectroscopic (NMR, IR, Raman, and UV-Vis) and emission studies. Single-crystal X-ray diffraction analysis was used to determine the molecular structure of the studied compounds, and the results were compared with DFT calculations (B3LYP/6-311G(2d,2p). The collected X-ray data revealed that the crystal of the hydrazo compound (4MDNPHP) belongs to the triclinic space group P$\overline{1}$ (Z = 2), whereas the crystal of the azo compound (4MDNPAP) follows the symmetry of the monoclinic space group P2₁/n (Z = 4). Both presented derivatives crystallized with one molecule in the asymmetric unit. Specific properties of the hydrazo bridge C_ϕ-NH-NH-C_θ moiety and its azo counterpart C_ϕ-N=N-C_θ were considered in detail. Full article

Benzyl 2,4-dichlorophenyl sulfoxide was synthesized both in racemic and in an enantiopure form. This enantiopure sulfoxide is a further successful confirmation of our straightforward protocol to yield easily chiral aryl benzyl sulfoxides. We solved also the crystal structure of racemic benzyl 2,4-dichlorophenyl sulfoxide with a single crystal X-ray diffraction experiment. The main interactions building up the crystal structure were recognized and compared with other similar sulfoxides. Full article

Perimidine derivatives are versatile heterocycles with growing significance in medicinal chemistry and materials sciences. However, their structural variety remains limited. This study focused on the synthesis and crystal structure characterization of a new perimidine-based molecule. A bicyclic perimidine lactone, (1S,4R)-4,7,7-trimethyl-1-(1H-perimidin-2-yl)-2-oxabicyclo[2.2.1]heptan-3-one (1), was synthesized through an intramolecular dehydration of a monoamide intermediate formed from 1,8-diaminonaphthalene and (1S)-(–)-camphanic chloride under basic conditions. The product was purified and crystallized from acetone, giving single crystals suitable for X-ray diffraction. Structural analysis revealed two stereogenic centers and crystallization in the chiral tetragonal P4₃2₁2 space group, with stabilization through N—H···O and C—H···N hydrogen bonds as well as C—H···π interactions. Full article

Quality assurance in aluminum die casting is critical, as internal defects—such as porosity—can compromise structural integrity and significantly reduce component service life. In the cost-sensitive manufacturing environment of Germany, early and automated rejection of defective parts is essential to minimize scrap, rework, and energy waste. This study investigates the feasibility and performance of deep learning for automated defect detection in industrial X-ray images of two series-production aluminum die-cast components. A systematic methodology was employed: first, candidate object-detection frameworks (YOLOv5 vs. Faster R-CNN) were evaluated under real-time constraints (<2 s per image) on standard industrial hardware; subsequently, position-specific and single global models were trained on annotated datasets. A systematic hyperparameter study—focusing on input resolution, learning rate, and loss weights—was conducted to optimize accuracy and robustness. The best-performing models achieved F1-scores up to 0.87, with position-specific models outperforming the single global model on average. The approach was validated under real production conditions at Hengst SE (Nordwalde), demonstrating practical feasibility, strong acceptance among quality professionals, and significant potential to accelerate inspections and standardize decision-making. The results confirm that deep learning is a viable alternative to rule-based image processing and holds substantial promise for automating X-ray inspection workflows in aluminum die casting, contributing to both operational efficiency and sustainability goals. Full article

Installation in sand is sensitive to its evolving pore structure, yet design models rarely update permeability for real-time fabric changes. This study tracks the stress-dependent pore size distribution of coarse sand under laterally constrained compression using high-resolution X-ray nano-CT. Scans taken at six axial stress levels show that the distribution shifts toward smaller radii while keeping its log-normal shape. A single shifting factor, defined as the current median radius normalized by the initial value, captures this translation. The factor decays with axial stress according to a power law, and the exponent as well as the reference pressure are calibrated from void ratio data. The resulting closed-form expression links mean effective stress to pore radius statistics without extra fitting once the compressibility constants are known. This quantitative relation between effective stress and pore size distribution has great potential to be embedded into coupled hydro-mechanical solvers, enabling engineers to refresh hydraulic permeability at every computation step, improving predictions of excess pore pressure and soil resistance during suction anchor penetration for floating wind foundations. Full article

Cu₂ZnSnSe₄ is a promising light-absorbing material for cost-effective and eco-friendly thin-film solar cells; however, its synthesis often leads to secondary phases that limit device efficiency. To overcome these challenges, we devised a straightforward and efficient method to obtain single-phase Cu₂ZnSnSe₄ nanocrystalline powders directly from the elements Cu, Zn, Sn, and Se via mechanochemical synthesis followed by vacuum annealing at 450 °C. Phase evolution monitored by X-ray diffraction (XRD) and Raman spectroscopy at two-hour milling intervals confirmed the formation of phase-pure kesterite Cu₂ZnSnSe₄ and enabled tracking of transient secondary phases. Raman spectra revealed the characteristic A₁ vibrational modes of the kesterite structure, while XRD peaks and Rietveld refinement (χ² ~ 1) validated single-phase formation with crystallite sizes of 10–15 nm and dislocation densities of 3.00–3.20 10¹⁵ lines/m². Optical analysis showed a direct bandgap of ~1.1 eV, and estimated linear and nonlinear optical constants validate its potential for photovoltaic applications. Scanning electron microscopy (SEM) analysis showed uniformly distributed particles 50–60 nm, and energy dispersive X-ray (EDS) analysis confirmed a near-stoichiometric Cu:Zn:Sn:Se ratio of 2:1:1:4. X-ray photoelectron spectroscopy (XPS) identified the expected oxidation states (Cu⁺, Zn²⁺, Sn⁴⁺, and Se²⁻). Electrical characterization revealed p-type conductivity with a mobility (μ) of 2.09 cm²/Vs, sheet resistance (ρ) of 4.87 Ω cm, and carrier concentrations of 1.23 × 10¹⁹ cm⁻³. Galvanostatic charge–discharge testing (GCD) demonstrated an energy density of 2.872 Wh/kg⁻¹ and a power density of 1083 W kg⁻¹, highlighting the material’s additional potential for energy storage applications. Full article

Four benzyltrimethylammonium (BTMA) salts were successfully prepared: bis(benzyltrimethylammonium) hexachloroplatinate (1), benzyltrimethylammonium tetrachloroaurate (2), bis(benzyltrimethylammonium) tetrachlorocuprate (3), and bis(benzyltrimethylammonium) tetrabromocuprate (4) from benzyltrimethylammonium hydroxide (Triton B). Their crystal structures were determined by single-crystal X-ray diffraction, and the supramolecular architectures were characterized hierarchically. Extended Hirshfeld surface analysis, including enrichment ratio calculations, was performed to evaluate intermolecular interactions. Nonclassical hydrogen bonds, such as C–H^…Cl(Br), involving the anions, contribute to the formation of self-assembled architectures. Additional stabilization arises from π^…π and Cu–Br^…π interactions, particularly in crystals 2 and 4, respectively. Hirshfeld surface analysis showed that H^…H and C^…H/H^…C interactions are the dominant contributors in all crystals. According to enrichment ratio calculations, C^…H/H^…C interactions in 1, 3, and 4; Cl^…H/H^…Cl in 1 and 3; Cu^…H/H^…Cu in 3 and 4; and Br^…H/H^…Br and Br^…C/C^…Br in 4 are statistically favored in the crystal packing. Halogen bonding Cl^…Cl was observed in 1 but does not significantly influence packing. Energy framework calculations indicated that dispersive interactions are favorable in the analyzed crystals. A library of H-bonding supramolecular patterns, including interchangeable synthons, is provided and may guide the rational design of new derivatives with controllable features. Finally, the topology of intermolecular connections and the electronic structure of the benzyltrimethylammonium cation, investigated by quantum-chemical calculations, provide insights into its reactivity. Full article

This study presents SpineCheck, a fully integrated deep-learning-based clinical decision support platform for automatic vertebra segmentation and Cobb angle (CA) measurement from scoliosis X-ray images. The system unifies end-to-end preprocessing, U-Net-based segmentation, geometry-driven angle computation, and a web-based clinical interface within a single deployable architecture. For secure clinical use, SpineCheck adopts a stateless “process-and-delete” design, ensuring that no radiographic data or Protected Health Information (PHI) are permanently stored. Five U-Net family models (U-Net, optimized U-Net-2, Attention U-Net, nnU-Net, and UNet3++) are systematically evaluated under identical conditions using Dice similarity, inference speed, GPU memory usage, and deployment stability, enabling deployment-oriented model selection. A robust CA estimation pipeline is developed by combining minimum-area rectangle analysis with Theil–Sen regression and spline-based anatomical modeling to suppress outliers and improve numerical stability. The system is validated on a large-scale dataset of 20,000 scoliosis X-ray images, demonstrating strong agreement with expert measurements based on Mean Absolute Error, Pearson correlation, and Intraclass Correlation Coefficient metrics. These findings confirm the reliability and clinical robustness of SpineCheck. By integrating large-scale validation, robust geometric modeling, secure stateless processing, and real-time deployment capabilities, SpineCheck provides a scalable and clinically reliable framework for automated scoliosis assessment. Full article

To identify the principal controls on gas-bearing property heterogeneity in tight reservoirs of the Shaximiao Formation in the southwestern Sichuan Basin, this study systematically examines pore structure characteristics and their influence on reservoir quality through an integrated approach incorporating cast thin sections, X-ray diffraction (XRD), high-pressure mercury injection (HPMI), and parameters such as homogeneity and variation coefficients. The research has indicated that the following findings: (1) The reservoir lithology in the study area is predominantly lithic arkose, with pore types dominated by residual intergranular pores and intragranular dissolution pores, and pore-throat radii ranging from 5 nm to 1 μm. (2) The disparity in reservoir quality is attributed to two primary factors. Firstly, diverse sediment provenance directions and varying mineral compositions directly influence the internal pore structure of the reservoirs. Secondly, differences in diagenetic minerals lead to heterogeneity in pore space development. Specifically, early carbonate cementation in the Pingluoba reservoir occluded porosity, resulting in poor physical properties. In the Yanjinggou reservoir, clay mineral cementation and pore-filling activities significantly reduced reservoir quality. In contrast, the presence of chlorite coatings in the Baimamiao and Guanyinsi reservoirs helped preserve primary porosity, contributing to superior reservoir properties. (3) The variation in gas content between different gas reservoirs is primarily attributed to differences in reservoir heterogeneity on a planar scale, whereas the gas content variation within different intervals of the same gas reservoir is controlled by differences in pore structure among various sand units. Furthermore, gas content heterogeneity within the same interval of a single reservoir results from variations in sand body thickness and connectivity. Full article

The effects of Ge⁴⁺ substitution on the microwave dielectric properties of inverse spinel Mg₂SnO₄ ceramics were systematically investigated. A series of Mg₂(Sn_1−xGe_x)O₄ (x = 0.00–0.05) ceramics were synthesized via solid-state reaction and sintered at 1450–1600 °C. X-ray diffraction confirmed single-phase inverse spinel structures (Fd-3 m) for compositions up to x = 0.03, while minor MgSnO₃ secondary phases appeared at x = 0.05. Rietveld refinement revealed a linear decrease in lattice parameter from 8.6579 Å (x = 0) to 8.6325 Å (x = 0.05), consistent with Vegard’s law for the substitution of smaller Ge⁴⁺ (0.53 Å, Shannon ionic radius, octahedral coordination) for Sn⁴⁺ (0.69 Å, Shannon ionic radius, octahedral coordination) in octahedral sites. Optimal dielectric properties were achieved at x = 0.03 sintered at 1550 °C; the dielectric constant (ε_r) increased from 7.6 to 8.0, while the quality factor (Qf) improved by 19% from 56,200 to 67,000 GHz, which is attributed to reduced phonon scattering from Ge-induced lattice contraction. The temperature coefficient of resonant frequency (τ_f) remained stable (−64 to −68 ppm/°C) across all compositions. Property degradation at x = 0.05 correlated with the onset of Ge⁴⁺ solubility limit and MgSnO₃ formation. These results demonstrate that controlled Ge⁴⁺ substitution effectively enhances the microwave dielectric performance of Mg₂SnO₄ ceramics for communication applications. Full article