Search Results (1,463)

The counterfeiting of official documents and banknotes represents a critical threat to global security and requires robust and low-cost protection techniques. This work presents an innovative information security system that uses photoluminescent inks for chromatic multiplexing of QR codes. Unlike conventional cryptographic methods, the proposed approach employs physical-layer information hiding through the superposition of two QR codes encoded in magenta and cyan colors on a white background. The controlled interaction between these codes generates an additional logical state that enables a third representation of information through pixel-level operations. The resulting chromatic QR code remains visually imperceptible under ambient illumination and can be reliably recovered through chromatic demultiplexing and thresholding process. Additionally, its visibility can be enhanced under ultraviolet (UV) excitation due to photoluminescent behavior and spectral response variations. The experimental results demonstrate that both encoded data layers can be extracted independently with high fidelity using standard CMOS sensors, while preserving structural integrity and decodability. The proposed scheme increases information density within a single optical tag while improving resistance against unauthorized replication and visual forgery. Full article

Underwater images exhibit severe colour distortion, low contrast, and blurred details due to light absorption and scattering, which limits their practical use in marine applications. Existing methods face poor generalisation, high computational costs and weak integration of physical priors. To address these issues, this paper proposes TIDE-Net, a triple-branch illumination and detail enhancement network for underwater images. It decomposed inputs into illumination, reflectance intensity, and chromaticity branches for parallel optimisation, enabling decoupled handling of brightness, texture, and colour degradation. A piecewise colour correction module mitigated complex colour casts without introducing artefacts; a lightweight U-Net branch enhanced fine details while suppressing noise; and a local gain compensation module improved brightness uniformity and reduced halo effects. Experiments on four datasets showed that TIDE-Net outperforms some state-of-the-art methods, achieving a PSNR of 29.44 dB, an SSIM of 0.94, and competitive UIQM/UCIQE scores with only 7.74 M parameters. The results confirmed that the proposed triple-branch strategy effectively balances physical interpretability, restoration quality, and computational efficiency. In conclusion, TIDE-Net provides a robust and lightweight solution suitable for deployment on resource-limited underwater platforms, offering practical value for real-world underwater vision tasks. Full article

Background: The influence of surface sealants on the color stability of composite resin restorations remains controversial. This in vitro study evaluated the effect of two surface sealants on the color stability of a nanohybrid composite resin exposed to staining beverages. Methods: Ninety specimens of Enamel Plus HRi Bio Function (BF2) composite resin were divided into three groups: without sealant, with Embrace™ WetBond™ Seal-n-Shine™, and with Ena Bond Seal. Specimens were immersed in black tea, Coca-Cola^®, red wine, orange juice, coffee, or distilled water for 40 h. Color measurements were obtained before and after immersion using the OptiShade colorimeter in accordance with the CIELAB color system. Results: Significant differences were observed according to both the staining solution and the surface sealant applied (p < 0.001). Red wine produced the highest color changes in all groups, while coffee and black tea also caused clinically perceptible discoloration. The Seal-n-Shine™ group exhibited the highest ΔE values and greater color variation compared with the control group. In contrast, the Ena Bond Seal group exhibited chromatic behavior closer to that of the unsealed composite resin. Conclusions: Color stability was significantly influenced by both the staining solution and the applied surface sealant. Full article

Visual discomfort or visual stress is an uncomfortable subjective experience that occurs in response to specific visual stimuli. It affects a large proportion of the population to various degrees, disproportionately impacting those with heightened sensory sensitivities, particularly neurodivergent individuals. We argue that this might stem from a mismatch between the statistical properties of visual stimuli in human-made environments and those in natural environments that the visual system can process efficiently. We discuss the inefficiency with which images with certain spatial, chromatic and temporal characteristics are processed by the visual system and propose a cerebral mechanism to account for the discomfort they induce. The mechanism offers a potential explanation for the large individual differences in susceptibility to discomfort. We highlight two avenues for intervention: (1) environmental modifications aimed at reducing the prevalence of visually stressing stimuli in urban settings, and (2) individual-level strategies, such as personalised optical treatments. Addressing these challenges requires an interdisciplinary effort bridging neuroscience, vision science, interior and urban design and typography to create visually accessible and inclusive environments. Full article

Fruit pomace derived from traditional distillation has emerged as a valuable source of nutrients and bioactive compounds in sustainable food systems. This study investigated the nutritional and physicochemical characteristics of plum, peach, sour cherry, and quince pomace generated during the production of traditional Romanian fruit distillates. Samples were characterized in terms of proximate composition, color parameters, mineral composition, and B-complex vitamin content. Carbohydrates were the predominant macronutrients (59.97–69.30 g/100 g dw), while quince and peach pomace exhibited the highest fiber contents, reaching values of 27.47 ± 0.55 g/100 g dw and 27.37 ± 0.50 g/100 g dw, respectively. Sour cherry pomace showed the highest protein (10.83 ± 0.20 g/100 g dw) and ash levels (5.41 ± 0.11 g/100 g dw), whereas peach pomace was richest in lipids (2.98 ± 0.06 g/100 g dw). Color analysis revealed distinct chromatic characteristics among samples. Potassium, calcium, and magnesium were the dominant minerals, with plum pomace presenting particularly high potassium and calcium concentrations. In addition, peach pomace exhibited the highest levels of vitamins B2 (1987.73 ± 20 µg/100 g dw), B7 (906 ± 8 µg/100 g dw), and B9 (14.18 ± 0.1 µg/100 g dw). These findings support the valorization of fruit pomace as a nutritious functional ingredient within circular economy frameworks. Full article

The evolution of neutron scattering from reactor-based steady-state sources to high-power pulsed spallation sources has necessitated a paradigm shift in neutron optics. While pulsed sources offer high peak brilliance and energy-resolved measurements via the time-of-flight (TOF) technique, the intrinsic divergence and broad wavelength bandwidth of the incident beam pose significant challenges for focusing, particularly in the realm of very small-angle neutron scattering (VSANS, Q < 0.001 Å⁻¹). This review presents a comprehensive analysis of diverse focusing techniques, including converging multi-slit apertures, electrical and superconducting magnetic sextupole lenses, grazing-incidence focusing mirrors, compound refractive lenses with oscillation apertures, and a special multi-beam VSANS configuration. Special attention is given to the transition from permanent magnet systems to nested rotating sextupole permanent magnets (Nest-Rot-SPM) and modulated superconducting sextupoles (SSM), detailing the physical and engineering challenges involved. Furthermore, grazing-incidence reflective optics, notably toroidal Wolter mirrors, are discussed as an achromatic alternative. The integration of these technologies into world-leading pulsed neutron sources is reviewed to project the future landscape of extended Q-range coverage for SANS instruments. Full article

For the removal of hexavalent chromium [Cr(VI)] from drinking water, a hybrid biosorbent designated chitosan–natural diatomaceous earth (CNDE) was developed and thoroughly characterized. The material couples the ion-exchange and chelating capacity of chitosan—applied at an 85% degree of deacetylation—with the high-surface-area mineral framework of natural diatomaceous earth, onto which the polymer was deposited as a conformal coating. Surface morphology and internal microstructure were examined by scanning and transmission electron microscopy (SEM/TEM), while elemental composition across the hybrid matrix was resolved by energy-dispersive X-ray spectroscopy (EDX). Fourier transform infrared (FTIR) spectroscopy was employed to identify the surface functional groups responsible for chromate binding, and streaming current measurements established the pH of zero charge (pH_pzc), which governs the electrostatic environment at the sorbent–solution interface. Specific surface area was quantified by the Brunauer–Emmett–Teller (BET) method, and the balance of surface acidic and basic sites was determined through titrimetric analysis of total acidity and alkalinity. Thermogravimetric analysis (TGA) was conducted to assess thermal stability. Batch equilibrium isotherm experiments were performed to evaluate Cr(VI) uptake from model drinking water prepared using dilute potassium dichromate solutions adjusted to target pH levels. The effects of solution pH and competing anions (chloride and sulfate) were also investigated. Kinetic studies were conducted to determine the rate of Cr(VI) adsorption, and residual metal concentrations were measured using inductively coupled plasma mass spectrometry (ICP-MS). Results indicated that CNDE containing 30% chitosan (CNDE30) achieved effective Cr(VI) removal at pH 5. Adsorption was strongly pH-dependent, decreasing as pH increased from 5 to 8. Equilibrium data were well described by both Langmuir and Freundlich isotherm models, while kinetic data followed a pseudo-second-order model. The presence of chloride ions (15 mg/L) reduced adsorption capacity by approximately one-third, whereas sulfate at the same concentration significantly inhibited Cr(VI) removal. Overall, the isotherm results suggest that CNDE30 is a promising material for Cr(VI) removal from drinking water. Its cost-effectiveness, ease of synthesis, and potential for reuse make it particularly attractive for small-scale and decentralized water treatment applications. Full article

Raramuri Criollo (RC) cattle from Mexico have special genetic and resilience characteristics which have positioned them as an important alternative for future meat production under arid conditions. Despite the remarkable hardiness of RC cattle, their meat has been anecdotally catalogued as lean, tough and unattractive for consumption. However, abundant information about RC meat quality has not been documented to date. This study evaluated technological characteristics and tenderness of Longissimus lumborum muscle from Raramuri Criollo cattle compared to a commercial Hereford × Angus (H × A) crossbreed during dry ageing. pH, water-holding capacity (WHC), Warner–Bratzler shear force (SF), and instrumental colour were analyzed at 0, 15 and 30 d of ageing. pH values remained within the normal physiological range (5.4–5.5) for high-quality beef in both genetic groups. WHC showed significant differences among days of ageing, but not by racial group (p > 0.05). Additionally, RC beef demonstrated higher chromatic stability than H × A meat during ageing. Meat from H × A animals exhibited faster early tenderization, while RC beef showed a more gradual and sustained reduction in SF, with RC reaching lower SF than meat from crossbred animals by d 30 of ageing. From day 0 to day 15 SF decreased by 9.48 N and 12.16 N for RC and H × A meat, respectively, while from day 16 to day 30 the SF showed decreases of 4.73 and 2.11 N for RC and H × A meat respectively. In conclusion, RC meat is as tender as H × A after 30 d ageing without deterioration in its technological properties. These findings highlight the potential of RC to produce competitive tender meat, supporting valorisation of indigenous cattle genetic resources as a viable strategy for sustainable beef production in arid environments. Full article

The detection of small archaeological artifacts in high-resolution aerial imagery is challenged by minimal target size and local spectral and geometric similarity to background soils. This study identifies a failure mode in end-to-end deep learning where radiometrically dominant chromatic signals destabilize gradient-based optimization, leading to rapid training collapse. Using UAV imagery of Maya archaeological sites in Belize, we examine fingernail-sized ceramic sherds characterized by a consistent reddish hue. A Hue-Weighted Loss Function (HWLF) is introduced as a diagnostic instrument. Under severe class imbalance, chromatic gradients suppress geometric feature learning, collapsing detection within 300 iterations. Motivated by this discovery, we propose a staged detection architecture that decouples geometric candidate generation from chromatic validation. Candidates are detected via a transformer-based object detector and validated using hue constraints derived from unmodified 16-bit HSV representations. This approach reduced the Phase I candidate pool (177,148 geometric detections) to 1647 prioritized detections—a 99.1% reduction—while retaining 97.8% of annotated targets (F1 = 0.731). Chromatic priors may be more effective as decoupled post-inference discriminants than as embedded end-to-end optimization signals under severe class imbalance, where their gradient influence risks suppressing geometric feature learning entirely. Full article

Storage duration critically shapes the characteristic sweet and mellow quality of ripened pu-erh tea (RPT), yet the underlying chemical mechanisms remain poorly understood. This study investigated the sensory and chemical evolution of a representative commercial RPT product across a nine-year storage gradient (1, 3, 5, 7, and 9 years) by integrating Quantitative Descriptive Analysis (QDA), chromaticity measurement, targeted quantification of 42 non-volatile components, and Headspace Gas Chromatography–Mass Spectrometry (HS-GC-MS) volatilomics with multivariate statistical modeling. Prolonged storage drove systematic sensory maturation: the stale aroma gradually purified, and the taste profile transitioned significantly from heavy and mellow to sweet and mellow (p < 0.05), accompanied by a deepening infusion color with increased redness and yellowness indices. Targeted chemical profiling revealed significant decreases in total polyphenols and astringent esterified catechins, particularly epicatechin gallate (ECG) and epigallocatechin gallate (EGCG) (p < 0.05), while theabrownins remained stable and soluble sugars peaked at intermediate storage stages. Pearson correlation analysis linked these chemical shifts to sensory perception, with enhanced sweetness, mouthfeel thickness strongly associated with reduced monomeric catechins and free amino acids (p < 0.001). Volatilomics combined with K-means clustering and relative odor activity value (ROAV) analysis revealed a dual mechanism of flavor refinement: progressive accumulation and increasing odor activity of aged aroma markers (1,2,3-trimethoxybenzene, β-ionone) coupled with systematic attenuation of pungent acids and grassy aldehydes. These findings, based on a single, standardized commercial product, elucidate the chemical-sensory foundation of the sweet and mellow profile in aged RPT and provide candidate markers and a transferable analytical framework for quality assessment of stored teas. Full article

Accurate oil–water interface measurement in small transparent test tubes is important for subsequent volume readout in laboratory analysis. However, manual observation and conventional vision-based methods are easily affected by illumination variation, wall stains, and bubbles, while deep learning detectors alone usually provide only coarse semantic perception. To address this issue, a coarse-to-fine framework is proposed for robust oil–water interface measurement. In the coarse stage, YOLOv8n is used to provide semantic constraints for subsequent processing. In the fine stage, a Fisher-discriminative chromatic-weighted brightness feature is constructed from RGB information, where the RGB weights are derived from the Fisher criterion to enhance oil–water chromatic separability rather than using fixed grayscale or empirical channel weights. This feature is then fused with a SobelY-based vertical-gradient feature to improve interface localization. A stain-aware row-aggregation strategy with effective-pixel compensation is further introduced to suppress artefact interference. The validated interface position is finally converted into a volume readout, with additional correction for bubble-induced bias. The framework was validated on sampled frames from a complete shale-oil core pressing process conducted under mixed-lighting conditions. Stage-wise evaluation and ablation results indicate that the proposed design improves readout stability under stains, bubbles, and illumination variation, achieving a mean absolute error of 0.0159 mL and keeping the maximum error below 0.03 mL in the current experimental setup. Full article

Objective: Perillae Fructus (PF) (Perilla frutescens (L.) Britt.) and stir-fried Perillae Fructus (SFPF) are commonly used clinically for the treatment of cough and asthma, yet their quality control methods have not been fully established. Method: The best processing techniques of PF were optimized by one-variable-at-a-time (OVAT) analysis and Box–Behnken design (BBD); fingerprint combined with chemical pattern recognition techniques was employed to establish chromatographic fingerprints of PF and SFPF from different regions. Differential compounds were screened and the reliability of the established method was verified through quantitative analysis of multi-components; image processing technology was applied to determine chromaticity values and perform cluster heatmap analysis. The composition–color correlation of PF and SFPF was investigated. Result: Four characteristic components were identified through 36 batches of PF and SFPF, with rosmarinic acid, 5-hydroxymethylfurfural, caffeic acid and luteolin serving as discriminant markers differentiating PF and SFPF. The contents of seven components and the corresponding chromaticity parameters (L*, a*, b*) were determined to generate a visualized heatmap. Rosmarinic acid and caffeic acid showed positive correlations with L*, whereas a negative correlation was shown with b* and 5-hydroxymethylfurfural. Conclusions: This study provides a theoretical basis for judgment of processing endpoints and the rapid online quality monitoring of SFPF. Full article

Pumpkin (Cucurbita spp.) is a globally significant vegetable crop known for its high nutritional value and remarkable phenotypic diversity. Yet, the surge in new cultivar releases has overwhelmed traditional morphological descriptors, creating critical gaps in variety purity control and breeders’ rights enforcement. Despite the established utility of SNP markers as the gold standard for genetic analysis, a dedicated high-resolution molecular database for modern pumpkin cultivars remains unavailable. To address this gap, we conducted whole-genome resequencing (WGS) on 94 representative pumpkin cultivars (spanning C. moschata, C. maxima, and C. pepo). Clean reads were mapped to the Cucurbita maxima reference genome. We employed a stringent pipeline to identify genomic variants and utilized STRUCTURE software, Principal Component Analysis (PCA), and Neighbor-Joining (NJ) trees to evaluate population stratification. Linkage disequilibrium (LD) decay and DNA fingerprinting barcodes were also developed. A total of 8,873,150 high-quality variants were identified, including 7,345,007 SNPs and 1,528,143 InDels, with an average SNP density of 21,281.50 SNPs/Mb. Population analysis consistently categorized the 94 cultivars into two primary subpopulations (G1 and G2). The first two PCs accounted for 74.06% of the total genetic variance. Further analysis revealed that G1 possessed a more complex genetic architecture and slower LD decay compared to G2, suggesting distinct selection histories. Finally, we screened for highly informative biallelic SNPs to construct a DNA fingerprinting database, enabling precise sample discrimination through unique chromatic barcodes. This study fills a critical gap in pumpkin genomics by establishing a high-density SNP database and a robust fingerprinting system. These resources provide a definitive tool for variety certification, seed purity testing, and the advancement of molecular-assisted breeding in pumpkin. Full article

This study investigates the composition, morphology and cultural significance of red pigment traces identified on bone pointed tools discovered in the Chalcolithic tell settlement of Pietrele–Măgura Gorgana, attributed to the Kodjadermen–Gumelnița–Karanovo VI cultural complex (4600–4250 BC). The observed use-wear patterns are consistent with repeated contact with soft, non-abrasive materials, including hide working, pigment application on leather or other organic surfaces, fiber manipulation, and perforation of soft substrates. Use-wear analysis revealed polished and flattened distal ends, compatible with repeated use on soft, non-abrasive materials, such as hide, leather, fiber, or other organic substrates. The possibility of pigment application directly on skin, in a practice analogous to tattooing, as previously published, cannot be excluded but remains speculative in the absence of experimental reference data or residue evidence specifically linked to such use. An associated ceramic container was tentatively interpreted as a possible vessel for ochre preparation, suggesting local processing of the pigment. The artifacts were investigated using multi-analytical archaeometric methods: SEM-EDS, AFM, TEM, FTIR, Raman, TGA, CLSM and pseudo-color image segmentation and 3D rendering of porosity distribution. The results consistently identified an iron oxide-based pigment, dominated by hematite and/or goethite, specific to ochre. Pigment particles (50–300 nm) form a well-defined superficial layer on the bone substrate, without Fe–Ca reactions at the interface. The simultaneous presence of Ca, P, Si, Mg and K indicates a silicate matrix with an apatite component, compatible with local and poorly purified raw materials. CIELAB colorimetric analyses revealed significant chromatic variability, suggesting the use of hematite-rich pigments and possible thermal transformations of goethite. The results contribute to the understanding of the pigment technologies of the Chalcolithic communities of the Lower Danube. Full article