Search Results (1,366)

Broth cooking is a traditional pretreatment and ripening strategy for high-commercial-value dehydrated marine food, effectively enhancing its texture and rehydration properties. In this work, we characterized the structural information of Maillard reaction products (MRPs) derived from beef scrap stock and investigated their effects on the texture and rehydration performance of dehydrated abalone. The optical and structural properties of the MRPs were analyzed using X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), transmission electron microscopy (TEM), and fluorescence spectroscopy. These MRPs showed osmosis in abalone processing including pretreatment and drying. Low-field nuclear magnetic resonance (LF-NMR) results revealed that MRP pretreatment improved the moisture migration and physicochemical properties of dehydrated abalone. These findings suggest that MRPs, owing to their high osmotic efficiency and nanoscale size, could serve as promising food additives and potential alternatives to traditional penetrating agents in the food industry, enhancing the rehydration performance of dried seafood and reducing quality deterioration. Full article

Asphalt plant reclaimed powder is a common solid waste in road engineering. Reusing reclaimed powder as filler holds significant importance for environmental protection and resource conservation. The key factors affecting the feasibility of reclaimed powder reuse are its acidity/alkalinity and cleanliness. Traditional evaluation methods, such as the methylene blue test and plasticity index, can assess reclaimed powder properties to guide its recycling. However, these methods suffer from inefficiency, strong empirical dependence, and high variability. To address these limitations, this study proposes a rapid and precise evaluation method for reclaimed powder properties based on Fourier transform infrared spectroscopy (FTIR). To do so, five field-collected reclaimed powder samples and four artificial samples were evaluated. Scanning electron microscopy (SEM), X-ray fluorescence spectroscopy (XRF), and X-ray diffraction (XRD) were employed to characterize their microphase morphology, chemical composition, and crystal structure, respectively. Subsequently, FTIR was used to establish correlations between key acidity/alkalinity, cleanliness, and multiple characteristic peak intensities. Representative infrared characteristic peaks were selected, and a quantitative functional group index (Is) was proposed to simultaneously evaluate acidity/alkalinity and cleanliness. The results indicate that reclaimed powder primarily consists of tiny, crushed stone particles and dust, with significant variations in crystal structure and chemical composition, including calcium carbonate, silicon oxide, iron oxide, and aluminum oxide. Some samples also contained clay, which critically influenced the reclaimed powder properties. Since both filler acidity/alkalinity and cleanliness are affected by clay (silicon/carbon ratio determining acidity/alkalinity and aluminosilicate content affecting cleanliness), this study calculated four functional group indices based on FTIR absorption peaks, namely the Si-O-Si stretching vibration (1000 cm⁻¹) and the CO₃²⁻ asymmetric stretching vibration (1400 cm⁻¹). These indices were correlated with conventional testing results (XRF for acidity/alkalinity, methylene blue value, and pull-off strength for cleanliness). The results show that the Is index exhibited strong correlations (R² = 0.89 with XRF, R² = 0.80 with methylene blue value, and R² = 0.96 with pull-off strength), demonstrating its effectiveness in predicting both acidity/alkalinity and cleanliness. The developed method enhances reclaimed powder detection efficiency and facilitates high-value recycling in road engineering applications. Full article

Color is a primary determinant of the value of jadeite jade, but the petrological provenance of the chromogenic elements of jadeite jade remains uncertain. The characteristics of the associated chromite in Myanmar jadeite jade were systematically investigated through a series of tests, including polarized microscopy, microarea X-ray fluorescence spectroscopy (micro-XRF) mapping, electron probe microanalysis (EPMA), and backscattered electron (BSE) imaging. The results demonstrate that the chromite composition in Myanmar jadeite jade is characterized by a high concentration of Cr₂O₃ (46.18–67.11 wt.%), along with a notable abundance of MnO (1.68–9.13 wt.%) compared with the chromite from the adjacent Myitkyina peridotite. The diffusion of chromium (Cr) and manganese (Mn) in jadeite jade is accomplished by accompanying the metamorphic pathway of Mn-rich chromite → kosmochlor → chromian jadeite → jadeite. In the subsequent phase of jadeite jade formation, the chromium-rich omphacite veins generated by the fluid enriched in Ca and Mg along the fissures of kosmochlor and chromian jadeite play a role in the physical diffusion of Cr and Mn. The emergence of the lavender hue in jadeite is contingent upon the presence of a relatively high concentration of Mn (approximately 100–1000 ppmw) and the simultaneous absence of Cr, which would otherwise serve as a more effective chromophore (no Cr or up to a dozen ppmw). The distinctive Mn-rich chromite represents the primary origin of the chromogenic element Cr (green) and, perhaps more notably, an overlooked provider of Mn (lavender) in Myanmar jadeite jade. Full article

The modern world has brought extensive socioeconomic and ecological changes. Urbanization in developing nations has significantly increased municipal solid waste, necessitating in-depth understanding of waste composition particularly in developing nations for sustainable management practices. This study aimed to classify and characterize waste while evaluating potential waste management methods. Mixed methods were used to examine landfilled waste from Soshanguve and Hatherley sites in Tshwane Metropolitan, South Africa, using techniques such as Fourier transform infrared spectroscopy, X-ray fluorescence, proximate, and ultimate analysis. Seasonal variations in waste components were analysed over two seasons. The study identified that both sites are predominantly composed of organic waste, accounting for over 42 wt.%, with moisture content of ~50 wt.%, and minimal recyclables (<5 wt.%). Seasonal variations in MSW were significant for glass (<4% increase), organic waste (<5% increase), while plastic decreased by ~7% during spring. The biodegradable waste showed high carbon (>50%) and oxygen (>40%) levels, low ash content (<18%), and calorific values of 15–19 MJ/kg. Biodegradables mainly contained oxides of calcium, silicon, iron (III), and potassium with chemical composition indicating functional groups that emphasize composting and energy recovery benefits. The research provides insights into sustainable waste management, revealing waste composition at Tshwane landfills, aiding informed decision-making for resource usage and environmental conservation. Full article

The cements industry is increasingly under pressure to reduce carbon emissions while maintaining performance standards. Limestone calcined clay cement (LC³) presents a promising low-carbon alternative; however, its performance depends significantly on the type and reactivity of clay used. This study investigates the effect of three common low-grade clay minerals—kaolinite, montmorillonite, and illite—on the behavior of LC³ blends. The clays were thermally activated and characterized using X-ray diffraction (XRD), thermogravimetric analysis (TGA), X-ray fluorescence spectroscopy (XRF), and Blaine air permeability testing to evaluate their mineralogical composition, thermal behavior, chemical content, and fineness. Pozzolanic reactivity was assessed using the modified Chapelle test. Microstructural development was examined through scanning electron microscopy (SEM) of the hydrated specimens at 28 days. The results confirmed a strong correlation between clay reactivity and hydration performance. Kaolinite showed the highest reactivity and fineness, contributing to a dense microstructure with reduced portlandite and enhanced formation of calcium silicate hydrate. Montmorillonite demonstrated comparable strength and favorable hydration characteristics, while illite, though less reactive initially, showed acceptable long-term behavior. Although kaolinite delivered the best overall performance, its limited availability and higher cost suggest that montmorillonite and illite represent viable and cost-effective alternatives, particularly in regions where kaolinite is scarce. This study highlights the suitability of regionally available, low-grade clays for use in LC³ systems, supporting sustainable and economically viable cement production. Full article

Fluorescent chemosensors are increasingly becoming relevant in recognition chemistry due to their sensitivity, selectivity, fast response time, real-time detection capability, and low cost. Boronic acids have been reported for the recognition of mycolactone, the cytotoxin responsible for tissue damage in Buruli ulcer disease. A library of fluorescent arylboronic acid chemosensors with various signaling moieties with certain beneficial photophysical characteristics (i.e., aminoacridine, aminoquinoline, azo, BODIPY, coumarin, fluorescein, and rhodamine variants) and a recognition moiety (i.e., boronic acid unit) were rationally designed and synthesised using combinatorial approaches, purified, and fully characterised using a set of complementary spectrometric and spectroscopic techniques such as NMR, LC-MS, FT-IR, and X-ray crystallography. In addition, a complete set of basic photophysical quantities such as absorption maxima (λ_abs^max), emission maxima (λ_em^max), Stokes shift (∆λ), molar extinction coefficient (ε), fluorescence quantum yield (Φ_F), and brightness were determined using UV-vis absorption and fluorescence emission spectroscopy techniques. The synthesised arylboronic acid chemosensors were investigated as chemosensors for mycolactone detection using the fluorescent-thin layer chromatography (f-TLC) method. Compound 7 (with a coumarin core) emerged the best (λ_abs^max = 456 nm, λ_em^max = 590 nm, ∆λ = 134 nm, ε = 52816 M⁻¹cm⁻¹, Φ_F = 0.78, and brightness = 41,197 M⁻¹cm⁻¹). Full article

This paper presents the synthesis of La₂Ti₂O₇ nanoparticles by the sol–gel method starting from lanthanum nitrate and titanium alkoxide (noted as LTA). Subsequently, the lanthanum titanium oxide nanoparticles are modified with noble metals (platinum) using the chemical impregnation method, followed by a reduction process with NaBH₄. The comparative analysis of the structure and surface characteristics of the nanopowders subjected to thermal treatment at 900 °C is conducted using Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray fluorescence (XRF), ultraviolet-visible (UV–Vis) spectroscopy, as well as specific surface area and porosity measurements. The photocatalytic activity is evaluated in the oxidative photodegradation of ethanol (CH₃CH₂OH) under simulated solar irradiation. The modified sample shows higher specific surfaces areas and improved photocatalytic properties, proving the better conversion of CH₃CH₂OH than the pure sample. The highest conversion of ethanol (29.75%) is obtained in the case of LTA-Pt after 3 h of simulated solar light irradiation. Full article

This study demonstrated the successful recovery of zinc, lead, and copper collective concentrates from historical metal-bearing mine tailings (sulfide–polymetallic ore with a composition of 7.38% Zn, 1.45% Pb, and 0.49% Cu) using froth flotation techniques, which were originally developed during uranium ore mining. Froth flotation techniques were used to justify suitability for recovering metals. The effects of a dosage of the foaming agent Polyethylene glycol (PEG 600) at 50 and 100 g t⁻¹, collector types Aerophine 3418A (AERO), Danafloat 067 (DF), and potassium ethyl xanthate (KEX) at 50 and 80 g t⁻¹, and a suspension density of 300 and 500 g L⁻¹ on froth flotation collective concentrates were investigated. The final collective concentrate achieved recoveries exceeding 91% for lead (Pb), 88% for copper (Cu), and 87% for zinc (Zn). The obtained concentrates were analyzed using Atomic Absorption Spectroscopy (AAS) and X-ray Fluorescence Spectrometry (XRF), while selected samples were further examined via Scanning Electron Microscopy (SEM) with Energy Dispersive X-ray Spectroscopy (EDS). The resulting sulfide concentrates can subsequently be treated using suitable hydrometallurgical techniques. The application of these concentrates in metal production would help reduce the environmental burden of mining activities. Full article

This work investigates photoactive inorganic powders (SiO₂, IrSiO₂, and IrO₂/IrSiO₂) and their derivatives modified with metallated porphyrin, focusing on their ability to generate reactive oxygen species (ROS) under visible light exposure. The core material, SiO₂, exhibits a tubular morphology and a high density of optically active defects. Modifiers such as metallic and iridium oxide nanoparticles, along with porphyrin, are employed to enhance light absorption and the generation of singlet oxygen (¹O₂) for potential biomedical applications. The time-dependent photogeneration of singlet oxygen is monitored using a Singlet Oxygen Green Sensor (SOSG), and its reactivity is evaluated in relation to DL α-Tocopherol through a spectrofluorimetric analysis. The photoactive materials, both before and after porphyrin modification, are characterized using Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), X-ray Diffraction (XRD), X-ray Fluorescence (XRF), UV–Vis Spectroscopy, X-ray Photoelectron Spectroscopy (XPS), N₂ adsorption–desorption measurements, and zeta potential measurements. Full article

The eastern Junggar Basin in Xinjiang, China is a key coal-bearing region dominated by the Middle Jurassic Xishanyao Formation. Despite its significance as a major coal resource base, detailed paleoenvironmental reconstructions of its coal seams remain limited. This study investigates the B₁, B₂, B₃, and B₅ coal seams of the Xishanyao Formation using X-ray fluorescence spectroscopy (XRF) and inductively coupled plasma mass spectrometry (ICP-MS) to assess geochemical indicators of the depositional environment during coal formation. The results show that the coal samples are characterized by high inertinite content and low vitrinite reflectance, indicative of low-rank coal. Slight enrichment of strontium (Sr) was observed in the B₁, B₂, and B₅ seams, while cobalt (Co) showed minor enrichment in B₃. Redox-sensitive elemental ratios (Ni/Co, V/Cr, and Mo) suggest that the peat-forming environment ranged from oxidizing to dysoxic conditions, with relatively high oxygen availability and strong hydrodynamic activity. A vertical trend of increasing paleosalinity and a shift from warm–humid to dry–hot paleoclimatic conditions was identified from the lower (B₁) to upper (B₅) coal seams. Additionally, the estimated atmospheric oxygen concentration during the Middle Jurassic was approximately 28.4%, well above the threshold for wildfire combustion. These findings provide new insights into the paleoenvironmental evolution of the Xishanyao Formation and offer a valuable geochemical framework for coal exploration and the assessment of coal-associated mineral resources in the eastern Junggar Basin. Full article

Twelve sherds of blue-and-white Chinese porcelains recovered from archaeological excavations in the Santana Convent (Ming and Qing Dynasties) in Lisbon were studied using several non-invasive spectroscopies, namely micro-Raman, X-ray Fluorescence (XRF), Ground State Diffuse Reflectance (GSDR), and stereomicroscopy. The use of the X-ray diffraction technique (XRD) allowed us to complete the mineralogical characterization of the ceramic bodies and glazes of the porcelains. The sample selection ranges from the 16th to the 18th centuries. The micro-Raman spectra clearly showed two types of glazes, alkaline glaze and calcium-based glaze. The GSDR absorption spectra of the blue glazes point to the use of different cobalt pigments, but a strong dependence on the glaze type does not seem to exist. The kilns where the porcelains were produced also play an important role. Both the GSDR absorption and the micro-Raman spectroscopies allow us to differentiate the Iranian blue pigment from the Chinese pigment. A direct and simple correlation between the use of Iranian blue pigment, mixtures of Iranian and Chinese pigments, or simply Chinese pigments and the stylistic dating of each sample was established. Furthermore, several important spectroscopic characterizations could be achieved in this study. Full article

Their demonstrable bioactive characteristics, coupled with their wide structural diversity and coordination versatility, render Schiff bases and their coordination complexes biologically active compounds demonstrating outstanding properties. This research describes the synthesis and characterization of new Cu(II) and Ni(II) complexes with an NNO-donor hydrazone ligand (HL). The crystal structure of the HL ligand was determined through single-crystal X-ray diffraction studies. The in vitro antibacterial activities of the HL ligand and its metal(II) complexes against Gram-positive and Gram-negative bacteria demonstrated that the metal(II) complexes displayed greater antimicrobial activities compared to the free Schiff base ligand. Furthermore, the interaction of the ligand and the complexes with calf thymus DNA (CT-DNA) was explored through electronic absorption and viscosity measurements, suggesting intercalation as the most likely mode of binding. The compounds promoted oxidative DNA cleavage, as demonstrated by the strand breaks of the pmChery plasmid under oxidative stress conditions. Finally, fluorescence spectroscopy also revealed the strong binding affinity of these compounds for bovine serum albumin (BSA). Full article

Eggshell quality inspection plays a pivotal role in enhancing the commercial value of poultry eggs and ensuring their safety. It effectively enables the screening of high-quality eggs to meet consumer demand for premium egg products. This paper analyzes the surface characteristics, ultrastructure, and mechanical properties of poultry eggshells. It systematically reviews current advances in eggshell quality inspection technologies and compares the suitability and performance of techniques for key indicators, including shell strength, thickness, spots, color, and cracks. Furthermore, the paper discusses challenges in non-destructive testing, including individual egg variations, species differences, hardware precision limitations, and inherent methodological constraints. It summarizes commercially available portable and online non-destructive testing equipment, analyzing core challenges: the cost–accessibility paradox, speed–accuracy trade-off, algorithm interference impacts, and the technology–practice gap. Additionally, the paper explores the potential application of several emerging technologies—such as tactile sensing, X-ray imaging, laser-induced breakdown spectroscopy, and fluorescence spectroscopy—in eggshell quality inspection. Finally, it provides a comprehensive outlook on future research directions, offering constructive guidance for subsequent studies and practical applications in production. Full article

In 1900, Francis Herbert Jennison’s book The Manufacture of Lake Pigments from Artificial Colours was published in London. In the early 20th century, the technical literature focussing on synthetic dyes mainly dealt with their use for dyeing. Conversely, the literature on lake pigment manufacture is less comprehensive, and Jennison’s publication was the first monograph on this topic. His book comprises descriptions of the dyes, substrates, and various methods for lake making. Practical examples complete the work: sixteen colour plates with original samples of lake pigments showcase the practical effect on colour of the different dyes and preparation methods. Herein, we present an overview of the context of Jennison’s research and delve into a selection of formulations. Green lake pigment plates were sampled and analysed by liquid chromatography coupled with spectroscopic and spectrometric detectors and by X-ray fluorescence spectroscopy to correlate the chemical composition with the recipes reported in the book. Seldom or no longer used and unexplored historical dyes were detected, along with polyphenolic compounds possibly used as precipitating agents in lake pigment formulations. Moreover, the examination of two different editions of the Jennison manuscript (i.e., the English and German books) revealed different chemical profiles corresponding to the same lake pigment formulation. This emphasizes the significance of Jennison’s book, confirming how understanding of early formulations is needed to elucidate the later ones. Full article

Significant research has been carried out on the applications of imaging and spectroscopy technologies for a variety of foods and agricultural products, and the technical fundamentals and their feasibilities have also been widely demonstrated in the past decade. Imaging technologies, including computer vision, Raman, X-ray, magnetic resonance (MR), fluorescence imaging, spectroscopy technology, as well as spectral imaging technologies, including hyperspectral or multi-spectral imaging, have found their applications in non-destructive tea quality assessment. Tea quality can be assessed by considering their external qualities (color, texture, shape, and defect), internal qualities (contents of polyphenols, amino acids, caffeine, theaflavin, etc.), and safety. In recent years, numerous studies have been published to advance non-destructive methods for assessing tea quality using imaging and spectroscopy technologies. This review aims to give a thorough overview of imaging and spectroscopy technologies, data processing and analyzing methods, as well as their applications in tea quality non-destructive assessment. The challenges and directions of tea quality inspection by using imaging and spectroscopy technologies for future research and development will also be reported and formulated in this review. Full article