Search Results (638)

This paper presents a wideband circularly polarized (CP) stacked patch antenna for 5G Sub-6 GHz applications. A major challenge in wideband dual-feed antennas is the fabrication limit caused by standard chemical etching and mechanical milling processes for extremely narrow high-impedance microstrip lines in two-stage branch-line couplers. To overcome this bottleneck, a Defected Ground Structure (DGS) is utilized. By etching the ground plane, the distributed inductance is increased, allowing the highly sensitive narrow traces to be physically widened while strictly maintaining the 50 Ω impedance. The antenna features an aperture-coupled mechanism via an H-shaped slot to excite the driven and parasitic patches, which are separated by an air gap to maximize bandwidth. The fabricated prototype demonstrates an impedance bandwidth (|S₁₁| < −10 dB) of 41.6% (2.92–4.37 GHz) and a simulated 3 dB axial ratio bandwidth of 23.14% (3.26–4.07 GHz) with a peak realized gain of 7.54 dBi. Excellent agreement between simulated and measured results validates the robustness of the proposed DGS technique against fabrication tolerances. Full article

Furfural is a pivotal indicator of the aging condition of transformer oil-paper insulation. Traditional analytical techniques such as liquid chromatography require sophisticated pretreatment and phase-separation procedures and are therefore not well suited to rapid oil-sample analysis. This study reports the direct analysis of furfural in complex oil mixtures using surface-enhanced Raman spectroscopy (SERS). The weak vibrational response of furfural in oil was enhanced using a Au-coated silicon nanowire substrate fabricated by metal-assisted chemical etching (MACE). The textured metal-coated surface enabled trace furfural at the μL/L level to be measured directly in the oil mixture without adsorption enrichment or chemical extraction, with the entire test process completed within 1 min. Peak deconvolution was used to extract the fitted area of the 1365 cm⁻¹ band, and the relationship between this Raman response and furfural concentration yielded R² = 0.9910. Temperature- and pressure-dependent measurements were also performed to examine their effects on the positions of the main Raman peaks. This work demonstrates a rapid approach for analyzing trace furfural in complex liquid mixtures and provides a basis for further spectroscopic studies of transformer oil-paper insulation aging. Full article

This article examines a group of Torah arks made for rural Jewish communities in German lands during the seventeenth and early eighteenth centuries. Scholarship on Ashkenazi synagogue furnishings has largely focused on monumental Torah arks associated with larger and wealthier communities. The examples discussed here reveal a different tradition, one that emerged under distinct social and material conditions and served smaller rural congregations. Drawing on an analysis of construction techniques, materials, and design, the article demonstrates that these arks were rooted in regional woodworking practices shared with contemporary furniture, cabinetry, and church furnishings. Produced in local workshops, likely by Christian craftsmen, they adapted familiar carpentry forms to Jewish liturgical requirements. Visible structural compromises, improvised solutions, and simplified construction techniques preserve traces of this process. Rather than evaluating these arks primarily against monumental urban examples, this study situates them within the regional material and craft environments in which they were produced. Their forms reflect a localized process of sacralization through which ordinary woodworking traditions were transformed into ritual furnishings and focal points of communal worship. By highlighting this group of objects, whose carpentry, construction, and relationship to regional furniture traditions have not been systematically examined, the article expands current scholarship on Torah ark design and demonstrates the diversity of material solutions developed by Jewish communities in early modern German lands. Full article

Microbial forensics has beneficial characteristics for investigating crimes. Law and order are fundamental to any nation and carry significant responsibilities. Failure in this domain may result in wrongful convictions or the guilty remaining free. Key duties include managing criminal cases and addressing threats to public order. While identifying the culprit, establishing their connection to the crime is paramount. Since legal systems require evidence for conviction, law enforcement increasingly relies on advancing scientific methods to meet this need. For example, in this case, after applying conventional techniques like DNA analysis and fingerprinting, a new technique, such as microbial forensics or fingerprints, can be applied. Trace evidence can be in the form of microbial fingerprints, and this evidence can play an important role in solving the crime. Microbial communities are dense and active in living and non-living things and in the environment. The classification and roles of these bacterial populations could be used as markers. The distinction between forensic samples is achievable because there is a diversity of microbial communities found in the human body from one location to another, and even in identical twins. The specific microbiome, which can be found on the skin or in specific body areas, may precisely identify the suspect’s connection with the crime scene for the purposes of human identification. This paper discusses the objects and latest advancements in the science of microbial forensics and their significance within the law enforcement process. Full article

This paper presents a summary of the activities carried out in relation to the shared objectives of the SCORPiò-NIDI project, an interdisciplinary research initiative aimed at investigating ballistic traces preserved along the northern fortification of Pompeii, produced by Roman siege engines during the siege of 89 BC. The study integrates digital surveying, computational modeling, experimental archaeology, and visualization techniques to document, analyze, and interpret specific types of anthropic damage caused by large stone projectiles and metal-tipped darts. High-resolution 3D acquisitions and reverse engineering processes guided the formulation of reconstructive hypotheses concerning projectile trajectories, impact velocities, and energy transfer mechanisms, supporting the determination of dimensional modules on the basis of which ancient treatises describe the proportional design of dart-throwing and stone-throwing machines in siege conditions. Mechanical simulations and comparative analysis provided quantitative validation of the virtual demonstrators prototyped and/or reconstructed using techniques and materials compatible with the pre-Christian period. The project further developed interactive digital models, animations, and visualization tools to support knowledge dissemination and public engagement. By combining archaeological data, engineering analysis, and human–computer interaction strategies, this research demonstrates the potential of digital technologies to enhance the study, interpretation, and communication of cultural heritage. Full article

Isotopic and nuclear techniques, including fallout radionuclides (FRNs), fingerprinting (FP), and isotope hydrology (IH), are essential tools for assessing soil and water degradation. However, as in state-of-the-art reviews, isolated application of FRNs, FP and IH limits their potential to address complex, interconnected environmental processes across landscapes. This study proposes a novel methodology based on the concept of Synergistic Convergence to integrate FRNs, FP, and IH into a unified framework for assessing soil and water degradation. Validated through a case study in Cuba’s Hanabanilla sub-basin, the five-stage methodology improves the identification of erosion hotspots, sediment sources, and water resource vulnerabilities. Results demonstrate that combining FRNs (quantifying soil redistribution), FP (tracing sediment sources), and IH (evaluating water dynamics) provides a robust approach for sustainable landscape management, according to the United Nations Sustainable Development Goals (SDGs) and the One Health framework. The integrated methodology proves superior to the non-integrated approach, connecting causes (erosion), drivers (water), and consequences (sedimentation, pollution). The Synergistic Convergence methodology effectively integrates isotopic and nuclear techniques (INTs) (FRNs, FP, and IH), enabling a holistic assessment of soil and water degradation and their interactions within terrestrial and aquatic ecosystems. Full article

Reliable determination of macro- and micronutrients in cereal plant tissues is essential for agronomic management, environmental monitoring, and interlaboratory data comparability. However, most existing plant certified reference materials (CRMs) are derived from temperate-region matrices and do not adequately represent cereals cultivated under semi-arid conditions, where differences in mineral composition may lead to matrix-related analytical bias. In this study, a new multi-element plant reference material, Cereal Plant Powder 2023 (CPP-23), was developed from composite wheat (Triticum aestivum and T. durum) samples collected across major Moroccan agro-ecological zones. The material was processed, homogenized, and evaluated for homogeneity and stability in accordance with ISO 33405:2024, with no significant short- or long-term variability observed. Elemental characterization was performed using microwave-assisted acid digestion followed by ICP-OES for major and trace elements, while total nitrogen was determined using the Kjeldahl method. Method validation demonstrated satisfactory linearity (R² > 0.995), precision, and trueness against established reference materials. Certified values were assigned through an interlaboratory comparison involving eight ISO/IEC 17025-accredited laboratories using robust statistical estimators (ISO 13528:2022). Expanded uncertainties (k = 2) were below 15% for all analytes. While these results indicate acceptable internal consistency, the relatively limited number of participating laboratories and the absence of independent analytical validation techniques represent important constraints. CPP-23 provides a matrix-representative material suitable for quality control and method validation in semi-arid agricultural systems. Nevertheless, its ability to reduce analytical bias relative to existing CRMs and its applicability to specific use cases require further experimental validation. Full article

High-purity quartz is a critical raw material for high-tech industries such as semiconductors and photovoltaics, yet its purity is severely constrained by gas–liquid inclusions within quartz crystals that are difficult to eliminate. The calcination–water quenching process is a key pretreatment step for removing inclusions and achieving deep purification, but its underlying mechanisms and the influence of process parameters on removal efficiency remain insufficiently understood. In this study, systematic calcination–water quenching experiments at different temperature gradients (500 °C, 700 °C, 900 °C, and 1100 °C) were conducted on high-purity quartz samples from Inner Mongolia and Angola. Comprehensive analytical techniques, including X-ray diffraction (XRD), major and trace element analyses, and polarizing microscopy, were employed to investigate the microstructural evolution, inclusion morphology, impurity element concentration changes, and phase transformation behavior before and after treatment. With increasing temperature, the quartz samples exhibited pronounced whitening and pulverization, accompanied by a significant reduction in the number of internal linear inclusions. Elemental analysis revealed that calcination–water quenching effectively removed certain alkali metals, alkaline-earth metals, and iron impurities, with 900 °C identified as the optimal calcination temperature; moreover, the sand-sized samples consistently showed better impurity removal efficiency than the lump-sized counterparts. XRD analysis was used to verify the phase transformation of quartz during calcination. Excessive temperatures (e.g., 1100 °C) led to a rebound in the content of some impurity elements. The calcination–water quenching process promotes inclusion decrepitation, exposure, and subsequent removal through the combined effects of volumetric strain induced by quartz phase transitions, thermal pressurization of inclusions, and thermal-shock stress from water quenching. This study establishes the optimal process window (hold at 900 °C for 2 h, sand-sized morphology) for the specific ore samples, elucidates the multi-factor synergistic mechanism of inclusion rupture, and provides both experimental and theoretical bases for the industrial purification of high-purity quartz. Full article

Soil contamination in underexplored environments remains poorly characterized, particularly in regions where systematic monitoring is limited. El-Bur (Somalia) represents one such environment, where prolonged drought, humanitarian instability, limited accessibility, and inadequate waste management are expected to influence soil quality while hindering systematic environmental investigations. In this study, an exploratory multi-technique approach was applied to soil samples collected from selected sites in El-Bur (Somalia) to obtain chemical, structural, and morphological information. A combination of SEM–EDX, ICP-OES, XRD, and GC–MS was used to characterize both inorganic and organic fractions. The results show a predominant presence of sodium chloride, indicating severe soil salinity likely associated with prolonged drought and evaporative processes. In addition, trace organic compounds, including plastic-related species such as diethyl phthalate and styrene, together with short- to medium-chain hydrocarbons, were detected, suggesting localized anthropogenic contamination likely related to plastic waste and inadequate wastewater and waste management practices. This work provides a proof-of-concept analytical framework for identifying contamination features in soils affected by severe drought. The findings highlight the coexistence of natural and anthropogenic drivers of soil degradation and provide exploratory evidence for future targeted investigations in underexplored regions. Full article

Advanced patterning technologies have evolved from direct optical image transfer into predictive manufacturing frameworks in which defects are shaped by imaging physics, material response, process variation, and computational correction. Starting from the development of resolution enhancement techniques (RET) and optical proximity correction (OPC), this review traces how conventional optical lithography became the foundation of modern computational lithography. The discussion then extends to extreme ultraviolet lithography (EUVL) and nanoimprint lithography (NIL), where defect mechanisms no longer follow the same geometry-driven correction logic. EUVL introduces stochastic resist response, photon-limited variability, and mask 3D effects, while NIL shifts the dominant defect origins toward resist filling, residual layer variation, template interaction, viscoelastic deformation, and demolding. This review focuses on two major modeling paradigms for defect prediction from an OPC-centric view: physics-based frameworks that provide mechanism-level interpretability, and data-driven frameworks that enable rapid pattern recognition, hotspot detection, layout-to-image prediction, and uncertainty-aware screening. Recent advances also point to hybrid physics–machine learning (ML) frameworks as a promising way forward by synergistically combining physical constraints, simulation-derived knowledge, and data-driven inference. In summary, this review emphasizes the transition from contour correction to physically grounded, data-efficient, and uncertainty-aware defect prediction in optical lithography, EUVL, and NIL. Full article

Hyperspectral imaging (HSI) is a state-of-the-art analytical technique that combines the use of conventional digital imaging and spectroscopy to capture both spatial and spectral information simultaneously in hundreds of narrow, adjacent wavelength bands. In recent decades, the progress in HSI has been rapid, and the technique has been increasingly utilized in forensic sciences, demonstrating its superiority to standard analytical techniques with respect to being non-invasive and contact-free. Although numerous forensic HSI articles have appeared in the literature in recent years, there has yet to emerge a systematic comparison of HSI performance, instrumentation, and cross-domain translational difficulties within forensic science. This review fills this important gap by analyzing the principles, instrumentations, methods of HSI data processing, and potential applications of HSI in forensics in the context of nine important fields: blood stain analysis and estimation of blood age; document authentication; fingerprint detection and enhancement; gunshot residue (GSR) analysis; analysis of trace evidences; detection of biological fluids; postmortem interval (PMI) estimation; determination of bruise age; and multidisciplinary applications. Comparative analysis of over fifty peer-reviewed articles published from 2010 to 2026 in HSI-based forensic sciences is provided herein, with classification accuracies between 81% and 100%. The use of chemometric and machine-learning methods, such as principal component analysis (PCA), support vector machines (SVM), partial least square discriminant analysis (PLS-DA), and Convolutional Neural Networks (CNNs), is carefully analyzed. Some problems concerning standardization, legal acceptance, data sets available, and forensic application are considered alongside future developments of HSI technology. Full article

In this study, the through-thickness texture of an accumulative roll-bonding (ARB)-processed aluminum single crystal was characterized using the Electron Backscatter Diffraction (EBSD) technique, and the texture reversal during ARB was investigated. Partitioned crystal rotation about the transverse direction (TD) and the activation of two sets of slip systems that resulted in TD-rotation and slip traces were evidenced. Reduced TD-rotation in certain layers of 2-ARB and 3-ARB corresponded to the destruction of previously formed slip traces, which resulted from the activation of the other set of slip systems. The partial texture reversal in ARB was experimentally revealed for the first time, and the revealing of texture evolution mechanisms helps with texture tailoring for better formability of ARB-processed sheet metals. Full article

Ultracold neutrons (UCNs) are free neutrons with kinetic energies so low that their equivalent thermal temperature lies below 3.5 mK (below 3 × 10⁻⁷ eV). At these extreme energies, neutrons exhibit de Broglie wavelengths on the order of hundreds of angstroms and move slowly enough to be confined in material, magnetic, and gravitational traps through total internal reflection. For context, this is about three orders of magnitude colder than the 1 K regime used in superfluid helium UCN sources, which underscores why these neutrons are called “ultracold”: their equivalent thermal energy is comparable to millikelvin physics, even though UCN sources themselves typically operate at 0.8–5 K and produce UCN through superthermal downscattering rather than thermal equilibrium. Over the past several decades, substantial progress in ultracold-neutron source technology has been achieved through the transition from mechanical neutron turbines to superthermal converters based on solid deuterium and superfluid helium. This review provides a comprehensive analysis of modern reactor-based (ILL, PNPI, TRIGA) and spallation-driven (PSI, TRIUMF, SNS, ESS) UCN sources, together with next-generation facilities targeting UCN densities of 10³–10⁴ cm⁻³. Particular attention is devoted to anomalous neutron losses during storage. It is shown that hydrogen-containing surface contaminants, inelastic scattering processes, and wall-induced depolarization contribute significantly to losses beyond those predicted for ideal materials. Current approaches for loss reduction are discussed, including diamond-like carbon coatings, magnetron sputtering techniques, optimization of the ortho–para ratio in neutron converters, and purification of superfluid ⁴He from trace concentrations of ³He impurities. The review further examines key precision experiments that drive advances in UCN technology, including investigations of the neutron lifetime discrepancy and searches for the neutron electric dipole moment at sensitivities approaching 10⁻²⁷–10⁻²⁸ e·cm as probes of CP violation and baryon asymmetry of the Universe. Finally, future directions for increasing UCN density, extending storage times, and enhancing the sensitivity of fundamental physics experiments are discussed. Full article

To achieve high interconnect density in 2.5D packages, various microscale structures such as through-silicon vias (TSVs), microbumps, and redistribution layers (RDLs) are employed. These features typically exist at the micron scale, whereas other package components span millimeter to centimeter scales, resulting in a wide range of physical dimensions within the package. Although finite element analysis (FEA) has proven effective for evaluating the mechanical and thermal characteristics of 2.5D packages, the inherent multi-scale nature poses significant computational challenges and numerical convergence issues, severely hindering the design and analysis of increasingly dense packages. To address this problem, this paper proposes an efficient numerical homogenization method for the mechanical and thermal analysis of 2.5D packages. The method employs periodic boundary conditions (PBCs) based on the concept of referential statistical volume elements (rSVEs). In this approach, typical microstructures—including TSVs, microbumps, and RDL traces together with the surrounding matrix material—are treated as a homogeneous medium, and the equivalent material properties of the multi-scale structures are evaluated. These properties include the stiffness matrices (from which the equivalent Young’s modulus, shear modulus, and Poisson’s ratio can be derived), coefficients of thermal expansion, and thermal conductivity. Validation results demonstrate that the proposed method ensures continuity of displacement, stress, strain, and heat flux across opposite surface pairs of the rSVEs. Compared with experimental measurements and other existing homogenization techniques, the method accurately determines the equivalent material properties of complex multi-scale structures without being restricted to specific geometries, while significantly improving computational efficiency. Finally, the proposed numerical homogenization method is successfully applied to wafer warpage analysis during the manufacturing process and to thermal analysis under operating conditions. The results indicate that the method achieves high computational efficiency while maintaining accuracy in both mechanical and thermal analyses of 2.5D packages, thereby laying a solid foundation for the development of next-generation 2.5D package structures. Full article

Alternative methodologies to analyze and quantify surface morphology using techniques such as Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) are of great interest to researchers. This study presents an approach using fractal dimension (D) analysis to characterize FeCrAl alloy plates oxidized in an air atmosphere at 750, 800, 850, and 900 °C for 24 h. SEM and AFM surface traces were used to determine the fractal dimensions via Rescaled Range (R\S) analysis using the BENOIT program; with this, it is expected that the fractal dimension results are between 1 ≤ D ≤ 2. The fractal dimension analysis describes with precision the surface morphology, given that local topographic features are represented by the analyzed traces. The experimental results demonstrate that D increases with the oxidation temperature for both techniques, which correlated with an increase in surface roughness. Specifically, SEM results in D values of 1.402, 1.545, 1.557 and 1.583, while AFM results in values of 1.494, 1.561, 1.573 and 1.593 at respective temperatures. Fractal dimension analysis is a robust tool for quantifying micro- and nanostructured roughness. This approach allows researchers to track surface changes induced by thermal, mechanical, or environmental processes, thus transforming SEM into a quantitative complementary technique. Full article