Reflection Scanning Research Articles

Attenuated Total Reflection Fourier Transform Infrared Spectroscopy and Chemometrics for the Discrimination of Animal Hair Fibers for the Textile Sector.

Analyzing the composition of animal hair fibers in textiles is crucial for ensuring the quality of yarns and fabrics made from animal hair. Among others, Fourier transform infrared (FT-IR) spectroscopy is a technique that identifies vibrations associated with chemical bonds, including those found in amino acid groups. Cashmere, mohair, yak, camel, alpaca, vicuña, llama, and sheep hair fibers were analyzed via attenuated total reflection FT-IR (ATR FT-IR) spectroscopy and scanning electron microscopy techniques aiming at the discrimination among them to identify possible commercial frauds. ATR FT-IR, being a novel approach, was coupled with chemometric tools (partial least squares discriminant analysis, PLS-DA), building classification/prediction models, which were cross-validated. PLS-DA models provided an excellent differentiation among animal hair of both camelids and eight animal species. In addition, the combination of ATR FT-IR and PLS-DA was used to discriminate the cashmere hair from different origins (Afghanistan, Australia, China, Iran, and Mongolia). The model showed very good discrimination ability (accuracy 87%), with variance expression of 94.88% and mean squared error of cross-validation of 0.1525.

SLOctolyzer: Fully Automatic Analysis Toolkit for Segmentation and Feature Extracting in Scanning Laser Ophthalmoscopy Images.

The purpose of this study was to introduce SLOctolyzer: an open-source analysis toolkit for en face retinal vessels in infrared reflectance scanning laser ophthalmoscopy (SLO) images. SLOctolyzer includes two main modules: segmentation and measurement. The segmentation module uses deep learning methods to delineate retinal anatomy, and detects the fovea and optic disc, whereas the measurement module quantifies the complexity, density, tortuosity, and caliber of the segmented retinal vessels. We evaluated the segmentation module using unseen data and measured its reproducibility. SLOctolyzer's segmentation module performed well against unseen internal test data (Dice for all-vessels = 0.91; arteries = 0.84; veins = 0.85; optic disc = 0.94; and fovea = 0.88). External validation against severe retinal pathology showed decreased performance (Dice for arteries = 0.72; veins = 0.75; and optic disc = 0.90). SLOctolyzer had good reproducibility (mean difference for fractal dimension = -0.001; density = -0.0003; caliber = -0.32 microns; and tortuosity density = 0.001). SLOctolyzer can process a 768 × 768 pixel macula-centered SLO image in under 20 seconds and a disc-centered SLO image in under 30 seconds using a laptop CPU. To our knowledge, SLOctolyzer is the first open-source tool to convert raw SLO images into reproducible and clinically meaningful retinal vascular parameters. It requires no specialist knowledge or proprietary software, and allows manual correction of segmentations and re-computing of vascular metrics. SLOctolyzer is freely available at https://github.com/jaburke166/SLOctolyzer. SLO images are captured simultaneous to optical coherence tomography (OCT), and we believe SLOctolyzer will be useful for extracting retinal vascular measurements from large OCT image sets and linking them to ocular or systemic diseases.

Enhanced thermal stability photophysical properties of photoselective PMMA/ITO nanohybrid films for greenhouse cooling in hot climates

The current research proposed innovative photoselective greenhouse cooling films made from PMMA/ITO nanohybrids, incorporating varying concentrations of Indium tin oxide nanocrystals (ITO NCs) and the fluorescent organic dye Lumogen F Red300, utilizing the solvent casting method. The morphology and structure were examined using transmission electron microscopy (TEM) and X-ray diffraction (XRD), demonstrating good homogeneity and amorphous nature. The impact of different ITO NC concentrations on physical properties was examined through differential scanning calorimetry (DSC), optical absorption, transmission, reflection, fluorescence, and Fourier transform infrared (FT-IR) spectroscopy. Integrating ITO NCs into the PMMA matrix showed enhanced thermal insulation capabilities of PMMA films while maintaining their transparency to photosynthetically active radiation (PAR). Maintaining this balance is crucial because it enables the films to selectively filter and reflect infrared radiation leading to lower greenhouse temperatures while still allowing the essential light needed for plant growth to pass through. This research is particularly significant for Sustainable Development Goals (SDGs) 2 and 13, especially in hot, water-scarce regions, as it protects plants from thermal stress, promotes growth, and supports food security in developing countries.

Recombinant laccase biosynthesis for efficient polydopamine coating

Laccases are versatile biocatalysts with interest for various industrial applications. This study reports the expression of Trametes versicolor laccase in Komagataella phaffii X33. The cultivation parameters (methanol and CuSO4 concentration, and temperature) for recombinant laccase production were studied in an orbital shaker. Enhanced laccase production was achieved by adding 1 % (v/v) methanol daily, supplementing 0.1 mM CuSO4 and incubating at 25 °C. Under these conditions, laccase production was scaled-up in a 4 L stirred tank bioreactor. Subsequently, laccase was concentrated and purified using a combined protocol of ultrafiltration and acetone precipitation, achieving a purification factor of 3.02. The laccase produced exhibited robust stability within a pH range from 4.0 to 8.0 and thermal stability up to 30 °C. Michaelis Menten kinetic revealed Michaelis constant (KM) and maximum rate of reaction (Vmax) values of 44.5 µM and 110.9 µM/min, respectively. Finally, laccase was employed as a biocatalyst to assist the polymerization of dopamine to polydopamine, allowing the one-step coating of cellulose filter paper, as confirmed by diffuse reflectance spectroscopy (UV-Vis DRS) and scanning electron microscopy (SEM). This work represents an advance in the field of laccase production in both orbital shaker and bioreactor, while demonstrating, for the first time, the laccase-assisted polymerization of dopamine for the coating of filter paper with polydopamine.

Ridged Apertures for LEO Direct Radiating Arrays in Ka-Band

This paper presents an extensive performance analysis of open-ended waveguide elements for direct radiating arrays with a high scan angle (±50° /60°). The evaluated designs are based on square and hexagonal apertures loaded with ridges. Both square and triangular lattices are considered in the framework of Ka-band downlink design requirements for future LEO mega-constellations. The parameter space defined by the monomodal condition has been explored to find an optimum value for each structure. The analyses carried out with both infinite and finite full-wave models in terms of active reflection coefficient, scan loss and cross-polar discrimination are in good agreement.

A multi-disciplinary analysis of the Portrait of Philip the Good in Dijon

One of the finest fifteenth-century portraits of the Burgundian Duke Philip the Good resides in the Musée des Beaux-Arts in Dijon. This small yet exceptionally crafted panel holds significance for both historians and art historians alike. Surprisingly, prior to this study, the context, the dating and the authorship of the piece remained obscure, and the widely circulated hypothesis of it being “a copy of a lost portrait by Rogier van der Weyden” has never been corroborated by convincing arguments. Clarifying the context, dating and authorship of the painting were the primary objectives of the investigations discussed in the article. Therefore, this painting underwent a multidisciplinary investigation spanning both the positive and human sciences. Macro-XRF scans were conducted alongside hyperspectral reflectance scans, multispectral imaging in the visible and infrared range, and optical coherence tomography. These analyses were complemented by an art historical study. As a result, a precise delineation between authentic and retouched sections was achieved. This article does not merely present the various perspectives separately but constructs a coherent narrative based on all these foundations. This holistic multidisciplinary research methodology produced a clear account, albeit with some scope for future inquiry. The involvement of the painter Pieter Cristus was conclusively demonstrated. This painter, whether himself personally, an assistant in the workshop or a contemporary follower, is attributed to the genesis of this work, which is presumed to be not the original portrait but a contemporaneous copy, possibly commissioned by the Burgundian Duke himself. While we no longer remain in the dark and have lifted some veils, this study also paves the way for further investigation into this panel and the numerous other portraits of Philip the Good.

Enhancement of Solubility and Dissolution Rate of Simvastatin Tablets by Liquisolid Compact Approach

The aim of the current work was to improve the solubility and dissolution rate of poorly water-soluble drug, simvastatin (SM) by using the liquisolid compact technique (LS; SM-LS). Liquid load factors, and excipient ratios were used to calculate the required amounts of excipients necessary to prepare the SM-LS and compressed to tablets according to mathematical models. Avicel PH102, Aerosil 200 and Crosspovidone (CP) was used as carrier, coating material and disintegrant, respectively. Drug-excipient mixtures were evaluated compatibility by Attenuated total reflectance (ATR) and differential scanning calorimetry (DSC). Prepared SM-LS formulations were evaluated for various pre-compression and post-compressional parameters, in-vitro dissolution, and stability studies (40 ± 2°C / 75 ± 5% RH) for 3 months. Among the different formulations, LS10 formulation which contains 30% drug, 5% CP, Avicel pH 102: Aerosil 200 (1:10) showed 14-folds increase in dissolution rate when compared with pure SM powder. FTIR-ATR and DSC studies confirmed that there was no interaction between the drug and excipients. Further, the LS10 formulation had shown comparable dissolution profile with commercially available tablet formulation. The LS10 formulation showed no significant changes in the physicochemical properties over 3 months during stability studies. Therefore, the SM loaded LS formulation could be considered as an alternative approach to enhance the solubility and dissolution for commercial formulations. Keywords: Liquisolids compacts, solubility, dissolution, carrier, coating material, stability.

Nanoscale ultrastructures increase the visual conspicuousness of signalling traits in obligate cleaner shrimps.

Signal theory predicts organisms should evolve signals that are conspicuous to intended receivers in natural signalling environments. Cleaner shrimps remove ectoparasites from reef fish clients and many signal their intent to clean by whipping long, white antennae. As white is a reliably conspicuous colour in aquatic environments, we hypothesized that selection has acted to increase broad-spectrum antennal reflectance in cleaners. Using scanning electron microscopy, optical models and reflectance measurements, we found that the antennae in three obligate cleaner species from two families (Palaemonidae and Lysmatidae) had thick (∼6 µm) chitinous layers or densely packed high refractive index spheres (300-400 nm diameter), which models show increase reflectance (400-700 nm). Two facultative and non-cleaning species had no visible antennae ultrastructure beyond the chitinous exoskeleton. Antennae reflectance was significantly higher in obligate cleaners than in facultative and non-cleaning species. Our results suggest that some obligate cleaners may have evolved ultrastructures that increase the conspicuousness of their antennae as signals.

Strain mapping in amorphous germanium thin films with scanning reflectance anisotropy microscopy

Strain imaging is a critical aspect in the design and characterization of opto-electronics, microelectronics, flexible electronics, and on-chip photonics. However, strain mapping techniques are often material specific and strain measurements in amorphous materials remain a challenge. Here, we demonstrate strain mapping and optical characterization of an amorphous semiconductor using scanning reflectance anisotropy microscopy. Using reflection anisotropy spectroscopy and finite element simulations on evaporated amorphous germanium films, we showcase the strain sensitivity of the ellipsometric parameters. We demonstrate nondestructive mapping for simple and complex strain states in amorphous systems. The sub-degree phase and amplitude sensitivity of the microscope is able to determine strain states on the order of 10−3.

SLO-Net: Enhancing Multiple Sclerosis Diagnosis Beyond Optical Coherence Tomography Using Infrared Reflectance Scanning Laser Ophthalmoscopy Images.

Several machine learning studies have used optical coherence tomography (OCT) for multiple sclerosis (MS) classification with promising outcomes. Infrared reflectance scanning laser ophthalmoscopy (IR-SLO) captures high-resolution fundus images, commonly combined with OCT for fixed B-scan positions. However, no machine learning research has utilized IR-SLO images for automated MS diagnosis. This study utilized a dataset comprised of IR-SLO images and OCT data from Isfahan, Iran, encompassing 32 MS and 70 healthy individuals. A number of convolutional neural networks (CNNs)-namely, VGG-16, VGG-19, ResNet-50, ResNet-101, and a custom architecture-were trained with both IR-SLO images and OCT thickness maps as two separate input datasets. The highest performing models for each modality were then integrated to create a bimodal model that receives the combination of OCT thickness maps and IR-SLO images. Subject-wise data splitting was employed to prevent data leakage among training, validation, and testing sets. Overall, images of the 102 patients from the internal dataset were divided into test, validation, and training subsets. Subsequently, we employed a bootstrapping approach on the training data through iterative sampling with replacement. The performance of the proposed bimodal model was evaluated on the internal test dataset, demonstrating an accuracy of 92.40% ± 4.1% (95% confidence interval [CI], 83.61-98.08), sensitivity of 95.43% ± 5.75% (95% CI, 83.71-100.0), specificity of 92.82% ± 3.72% (95% CI, 81.15-96.77), area under the receiver operating characteristic (AUROC) curve of 96.99% ± 2.99% (95% CI, 86.11-99.78), and area under the precision-recall curve (AUPRC) of 97.27% ± 2.94% (95% CI, 86.83-99.83). Furthermore, to assess the model generalization ability, we examined its performance on an external test dataset following the same bootstrap methodology, achieving promising results, with accuracy of 85.43% ± 0.08% (95% CI, 71.43-100.0), sensitivity of 97.33% ± 0.06% (95% CI, 83.33-100.0), specificity of 84.6% ± 0.10% (95% CI, 71.43-100.0), AUROC curve of 99.67% ± 0.02% (95% CI, 95.63-100.0), and AUPRC of 99.65% ± 0.02% (95% CI, 94.90-100.0). Incorporating both modalities improves the performance of automated diagnosis of MS, showcasing the potential of utilizing IR-SLO as a complementary tool alongside OCT. Should the results of our proposed bimodal model be validated in future work with larger and more diverse datasets, diagnosis of MS based on both OCT and IR-SLO can be reliably integrated into routine clinical practice.

Optimization of Weak Ultrasonic Defect Signal Detection of Carbon Fiber Composites Based on Double-Sided Pulse Reflection Scanning

Optimization of Weak Ultrasonic Defect Signal Detection of Carbon Fiber Composites Based on Double-Sided Pulse Reflection Scanning

Synthesis, characterization and photocatalytic activity of alginate based hybrid material for efficient degradation of organic pollutants under UV light and sunlight irradiation

This study reports the development of alginate based hybrid material (Alg/CuO-gC₃N₄) with copper oxide (CuO) and graphitic carbon nitride (gC₃N₄). The Alg/CuO-gC₃N₄ hydrogel bead was prepared by two step process is as follows: formation of CuO-gC₃N₄ by co-precipitation method and incorporation of CuO-gC₃N₄ in the calcium alginate (Alg) by ionotropic gelation method. The structural and morphological features of the Alg/CuO-gC₃N₄ was characterized using different techniques namely Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Thermogravimetric analysis (TGA), UV Diffuse Reflectance spectroscopy (UV-DRS) and Scanning electron microscopy (SEM). The photocatalytic activity of the Alg/CuO-gC₃N₄ was extensively evaluated by degrading methylene blue (MB) under UV–vis and sunlight irradiation. The influence of various parameters like pollutant type, initial dye concentration, catalyst dosage, effect of pH, light intensity and reusability was investigated. The Alg/CuO-gC₃N₄ achieved a maximum degradation efficiency of 86.26 % and 85.15 % for MB at a dye concentration of 1 × 10−5 M under UV–vis and sunlight irradiation respectively, within 60 min using 0.3 wt% of catalyst dosage. The Alg/CuO-gC₃N₄ exhibited excellent stability and reusability over multiple cycles. Additionally, the incorporation of CuO-gC₃N₄ in alginate facilitates in reducing the bandgap (2.54 to 2.28 eV) for efficient charge separation, further enhancing the overall photocatalytic activity.

Azo chromophore functionalized polyesters; Synthesis, characterizations and applications for efficient Electrocatalyst for oxygen evolution reaction and heavy metal ion detection

The current study focuses on the synthesis, characterization and investigation of the potential applications of azo chromophore functionalized polyesters and their composites with graphene derivatives. Employing the two-step diazotization coupling reaction, diazo diol monomers are synthesized. Subsequently, the azo polyesters are prepared via low-temperature solution polycondensation of the diazo diols with diacid chloride followed by the incorporation of graphene derivatives to obtain composite materials. Characterization techniques including Fourier transform Infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Ultraviolet-Visible Diffuse reflectance spectroscopy (UV–Vis DRS) and Scanning electron microscopy (SEM) are employed to evaluate the chain structure, degree of crystallinity, optical properties and morphology. Further, their electrocatalytic activity towards the oxygen evolution reaction (OER) and detection ability toward heavy metal ion was evaluated. The results demonstrate enhanced catalytic and detection capabilities attributed to synergistic interactions between polymer and graphene components. This study provides significant insights into the development of efficient polymer-graphene hybrid materials, with potential applications in green chemistry and environmental monitoring.

Unlocking the power of Inula Viscosa essential oil: A green solution for corrosion inhibition in XC48 steel within acidic environments

A sustainable corrosion inhibitor for XC48 steel in a 1 M HCl environment was effectively formulated using the essential oil of Inula viscosa (IVEO), as corroborated by gas chromatography-mass spectrometry (GC-MS) results. This novel application was assessed via multiple techniques: mass loss, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), Fourier-transform infrared spectroscopy with an attenuated total reflectance accessory (FT-IR/ATR), X-ray diffraction (XRD) and scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS) and Atomic Force Microscopy (AFM) for surface examination. The plant extract’s inhibitory capacity raised in proportion to its concentration, as confirmed by both mass loss and electrochemical investigations. This trend reached a high point at a 97% inhibitory efficiency at a concentration of 400 ppm at 298 K. FTIR, XRD, SEM/EDS, and AFM analyses further validated the binding of this eco-friendly inhibitor onto the steel surface, which exhibited mixed-type characteristics, thus elucidating its exceptional inhibitory performance. The Langmuir isotherm model aptly fitted the adsorption analysis, indicating the development of an organic protective layer. Advances computational calculations of various quantum chemical parameters for the key ingredients of the essential oil added to the understanding of the link between adsorption and corrosion inhibition.

Palaeoscolecids from the Ludlow Series of Leintwardine, Herefordshire (UK): the latest occurrence of palaeoscolecids in the fossil record

AbstractThe documentation of cuticular micro‐ornament is vital for the taxonomic assignment of palaeoscolecids: vermiform lower Palaeozoic ecdysozoans interpreted as stem‐group priapulans or early diverging panarthropods. This is due to the absence of the character‐rich proboscis and tail hooks in palaeoscolecid material not from Burgess Shale‐type Konservat‐Lagerstätten. Here, the cuticular micro‐ornamentation of palaeoscolecids from the upper Silurian (Ludlow) fauna of Leintwardine (Herefordshire, England), is described using scanning electron microscopy and reflectance transformation imaging. This material is taxonomically unstable because it was included in an effective wastebasket genus (Protoscolex) long before these imaging techniques were developed. The Leintwardine material is shown to be most closely comparable to a palaeoscolecid from the Darriwilian (Middle Ordovician) of the Builth–Llandrindod inlier, Powys, Wales, and is transferred accordingly to Radnorscolex Botting et al. as Radnorscolex latus (Bather). The Leintwardine fauna represents the uppermost stratigraphic occurrence of palaeoscolecids, constrained to the Saetograptus leintwardinensis Zone (lower Ludfordian), and the comparatively sparse Silurian palaeoscolecid record is subsequently discussed. It is hypothesized that palaeoscolecids may have become extinct during the mid‐Ludfordian Lau Event, the onset of which is recorded in the biozone immediately above the Leintwardine fauna (Bohemograptus Zone). Finally, the British palaeoscolecid fauna is summarized, including a new record from the Dapingian (Middle Ordovician) of Carmarthenshire, South Wales.

Antimicrobial treatments with chitosan microencapsulated angelica (Angelica archangelica) and marsh Labrador tea (Rhododendron tomentosum) supercritical CO2 extracts in linen-cotton jacquard woven textiles

In this study antimicrobial linen-cotton jacquard textiles were manufactured using green chemistry methods. The functionalization of the fabrics was executed by impregnating chitosan microencapsulated bio-based oils from angelica ( Angelica archangelica L.) (AAC) and marsh Labrador tea ( Rhododendron tomentosum Harmaja) (MLTC) obtained with pilot scale supercritical carbon dioxide extraction. The chemical compositions of the extracts of angelica and marsh Labrador tea were analyzed by a combination of gas chromatography and mass spectrometry. The antimicrobial activities of the extracts, AAC and MLTC microcapsules, and the microencapsulated textiles (AAC and MLTC textiles) were analyzed against gram-positive Staphylococcus aureus and gram-negative Escherichia coli bacteria, dimorphic yeast Candida albicans and filamentous mold Aspergillus brasiliensis. The AAC textile proved 40% inhibition against S. aureus, whereas the MLTC textile demonstrated 43.8% and 51.7% inhibition against both S. aureus and E. coli, respectively. Although the chitosan shell material itself indicated mild activity against both bacterial strains, the extracts increased the antibacterial activities in microencapsulated textiles. In addition, the antifungal impact of the MLTC textile was demonstrated against A. brasiliensis. According to the Fourier transform infrared spectroscopy with attenuated total reflection and field emission scanning electron microscopy analyses, covalent bonding between the microcapsules and textile fibers was established with citric acid as a cross-linker. The antimicrobial activity was also shown to persist in the MLTC textiles after six domestic washing cycles.

Thermo-mechanical aging of carbon-black reinforced styrene-butadiene rubber under cyclic-loading

PurposeThe research aims to investigate the impact of thermo-mechanical aging on SBR under cyclic-loading. By conducting experimental analyses and developing a 3D finite element analysis (FEA) model, it seeks to understand chemical and physical changes during aging processes. This research provides insights into nonlinear mechanical behavior, stress softening and microstructural alterations in SBR compounds, improving material performance and guiding future strategies.Design/methodology/approachThis study combines experimental analyses, including cyclic tensile loading, attenuated total reflection (ATR), spectroscopy and energy-dispersive X-ray spectroscopy (EDS) line scans, to investigate the effects of thermo-mechanical aging (TMA) on carbon-black (CB) reinforced styrene-butadiene rubber (SBR). It employs a 3D FEA model using the Abaqus/Implicit code to comprehend the nonlinear behavior and stress softening response, offering a holistic understanding of aging processes and mechanical behavior under cyclic-loading.FindingsThis study reveals significant insights into SBR behavior during thermo-mechanical aging. Findings include surface roughness variations, chemical alterations and microstructural changes. Notably, a partial recovery of stiffness was observed as a function of CB volume fraction. The developed 3D FEA model accurately depicts nonlinear behavior, stress softening and strain fields around CB particles in unstressed states, predicting hysteresis and energy dissipation in aged SBRs.Originality/valueThis research offers novel insights by comprehensively investigating the impact of thermo-mechanical aging on CB-reinforced-SBR. The fusion of experimental techniques with FEA simulations reveals time-dependent mechanical behavior and microstructural changes in SBR materials. The model serves as a valuable tool for predicting material responses under various conditions, advancing the design and engineering of SBR-based products across industries.

Effects of surface property on loading octaaza bis-α-diimine Ni complex, charge separation, and H2 production activity of MnS@ZnS photocatalysts

The MnS@ZnS photocatalyst was prepared using a microwave-assisted solvothermal method. Then, the octaaza bis-α-diimine Ni complex was loaded to prepare a composite photocatalyst. The adsorption of metal complex on photocatalyst depends on the anchoring groups of the Ni complex and the colloidal surface charge of the photocatalyst. The effects of the zeta potential of MnS and MnS@ZnS photocatalysts on the loading of Ni complex, separation of photogenerated carriers, and activity of Ni complex-modified composite photocatalysts were studied. The loading of NiC complex in photocatalysts was analyzed by Raman spectra, TEM line scan, mapping images, and total reflection x-ray fluorescence spectrometer. MnS@ZnS photocatalyst exhibits negative zeta potential that provides a strong electrostatic attraction force between photocatalysts and the Ni complex (Columb attraction), leading to increased Ni complex loading. MnS@ZnS/Ni complex exhibits better photocatalytic activity than MnS/Ni complex. Loading the Ni complex facilitates the photosensitization of photocatalysts, resulting in improved light absorbance. Besides, the electron-hole separation was further improved because the Ni complex acted as a redox mediator, enabling the transfer of electrons from MnS@ZnS to the Ni complex. The H2 production activity of MnS@ZnS/Ni complex photocatalyst reaches 3997 μmol h−1g−1, which is 1.72 times the pristine MnS.

Characterization of Tableware from Fábrica de Loiça de Sacavém—Linking Analytical and Documental Research

Fábrica de Loiça de Sacavém (ca. 1858–1994) was among the first to produce white earthenware in Portugal, becoming one of the country’s leading ceramic manufacturers during the late 19th to early 20th centuries. Research on white earthenware has accompanied the growing interest in post-industrial archaeology but is still poorly explored compared to more ancient ceramic productions. This study focused on the ceramic body, glazes, and colourants of tableware produced by Fábrica de Loiça de Sacavém during the first 50 years of its activity (1859–1910). A multi-analytical approach was selected to investigate the chemical and mineralogical composition of the ceramic body, glaze, and pigments using optical microscopy, variable-pressure scanning electron microscope energy-dispersive X-ray spectroscopy (VP-SEM-EDS), μ-Raman spectroscopy, μ-X-ray Diffraction (μ-XRD), and reflectance spectroscopy (hyperspectral image analysis). The studied tableware was produced with a Ca-poor siliceous–aluminous white earthenware ceramic body covered with transparent alkali lead or lead borosilicate glaze, and most colourants were complex Cr-based pigments. These results are in agreement with the little documental evidence from this period found in the manufacturer’s archives.

Delving into judiciously extracted inexpensive micro-algal dyes for DSSCs: Spectral decipherment and time-oriented extraction systems

The temperature and extraction techniques used for natural dye fabrication in dye-sensitized solar cells have significant implications for the future economy, influencing the efficiency and yield of dye extraction. This study analyzes the optical properties of microalgal dyes, examining reflectance and photo-electron energy scans, alongside emission rates in the UV–visible region, using aqueous methanol and ethanol solvents. Different time-oriented extraction methods, involving heating and a combination of sonication and heating, are assessed for their impact on specific and non-specific dye and pigment peaks. Extended heating periods result in dye degradation, while longer sonication proves efficient at 60 °C. The sonication technique's efficiency exponentially increases with Scenedesmus sp. concentration but not as much with Asterarcys quadricellulare at 60 °C. Asterarcys quadricellulare exhibits higher efficiency with ethanol, especially at 80 °C, and performs comparably with Scenedesmus sp. The optimal heating duration ranges from 10 to 25 min, while sonication is more efficient within 25 to 40 min for both temperatures.