Search Results (669)

Modern culture, strongly influenced by the growth of sectors such as the fashion and textile industries, has generated an environmental trend that is difficult to reverse. It is estimated that between 60 and 70% of the dyes used in these sectors are synthetic, which offer great versatility, a low cost, and a broad spectrum of colors, making them indispensable in many sectors. Among these synthetic dyes, azo dyes stand out due to their excellent chromophoric properties, structural stability, and ease of synthesis. However, these compounds are considered xenobiotics with a strong recalcitrant potential. This review article comprehensively examines the biodegradation potential of azo contaminants by microorganisms, including bacteria, fungi, microalgae, and consortia, using the PRISMA 2020 methodology. In this regard, this study identified 720 peer-reviewed articles on this topic that are outstanding. The analysis of these studies focused on the effect of parameters such as pH, temperature, and exposure time, as well as the enzymatic degradation pathways associated with the degradation efficiency of these contaminants. For example, the results identified that microorganisms such as Meyerozyma guilliermondii, Trametes versicolor, Pichia kudriavzevi, Chlorella vulgaris, and Candida tropicalis possess significant potential for degrading azo dyes (up to 90%). This degradative efficiency was attributed to the high enzymatic activity that cleaves the azo bonds of these contaminants through specialized enzymes, such as azoreductases, laccases, and peroxidases. Furthermore, the results highlight synergistic effects or metabolic cooperation between species that enhance the biodegradation of these contaminants, suggesting an eco-friendly alternative for environmental remediation. Full article

Beyond its renowned gemological value, diamond serves as a vital economic mineral and a unique messenger from Earth’s deep interior, preserving invaluable geological information. Since the Mengyin region is the source of China’s greatest diamond deposits, research on the diamonds there not only adds to our understanding of their origins but also offers an essential glimpse into the development of the North China Craton’s mantle lithosphere. In this article, 50 diamond samples from Mengyin were investigated using gemological microscopy, Fourier-transform infrared (FTIR) spectroscopy, Raman spectroscopy, DiamondView™, and X-ray micro-computed tomography (CT) scanning technologies. The types of Mengyin diamonds are mainly Type IaAB, Type IaB, and Type IIa, and the impurity elements are N and H. Inclusions in diamonds serve as direct indicators of mantle-derived components, providing crucial constraints on the pressure–temperature (P–T) conditions during their crystallization. Mengyin diamonds have both eclogite-type and peridotite-type inclusions. It formed at depths ranging from 147 to 176 km, which corresponds to source pressures of approximately 4.45–5.35 GPa, as determined by the Raman shifts of olivine inclusions. The discovery of coesite provides key mineralogical evidence for subduction of an ancient oceanic plate in the source region. The surface morphology of diamonds varies when they are reabsorbed by melts from the mantle, reflecting distinctive features that record subsequent geological events. Distinctive surface features observed on Mengyin diamonds include fusion pits, tile-like etch patterns, and growth steps. Specifically, regular flat-bottomed negative trigons are mainly formed during diamond resorption in kimberlite melts with a low CO₂ (X_CO2 < ~0.5) and high H₂O content. The samples exhibit varying fluorescence under DiamondView™, displaying blue, green, and a combination of blue and green colors. This diversity indicates that the diamonds have undergone a complex process of non-uniform growth. The nitrogen content of the melt composition also varies significantly throughout the different growth stages. The N3 center is responsible for the blue fluorescence, suggesting that it originated in a long-term, hot, high-nitrogen craton, and the varied ring band structure reveals localized, episodic environmental variations. Radiation and medium-temperature annealing produce H3 centers, which depict stagnation throughout the ascent of kimberlite magma and are responsible for the green fluorescence. Full article

Improving the end-of-life performance of polylactic acid (PLA) for food packaging requires strategies that enhance biodegradability, solubility, and dispersibility without compromising essential material properties. PLA-based films were produced by melt extrusion using polyvinylpyrrolidone (PVP) as a hydrophilic modifier, aiming to enhance the water uptake and affinity of PLA, which may potentially lead to faster environmental degradation. Two PVPs with distinct molar masses at varying concentrations were used to investigate their effects on the structural, thermal, mechanical, optical, and barrier behavior of the films. Thermal analysis revealed a slight depression in glass transition temperature, more evident in blends with low-molecular-weight PVP10, indicating increased chain mobility and partial miscibility. A two-step degradation process with extended thermal decomposition profiles was observed upon the inclusion of PVP. SEM and ATR-FTIR analyses confirmed enhanced dispersion and non-covalent interactions in PVP10-based blends, in contrast to the pronounced phase separation and micro-voids observed in PVP40-based systems. Mechanically, films containing 5 and 10 wt.% of PVP10 retained tensile strength and stiffness, whereas PVP40 led to embrittlement. Optical properties were modified by increasing the PVP content, resulting in greater opacity and color differences, which potentially offer benefits for light-sensitive packaging. Altogether, PLA films containing 5 and 10 wt.% of PVP10 demonstrated the most favorable balance between water affinity-oriented design and packaging-relevant performance. Full article

The objective of the study was to investigate the effects of low-protein amino acid-balanced (LPAB) diets supplemented with Astragalus polysaccharides (APSs) on the production performance, antioxidants, immunity, and biochemical index of laying hens in an elevated-temperature environment. Fifty-two-week-old Hy-Line Brown chickens (n = 768) were randomly divided into four groups, with eight replicates of 24 hens each. The control group was kept at 24 °C with a basal diet (CON), while the treatment groups were exposed to 32 °C and given the following diets: basal (HB), LPAB (HL), and LPAB with 0.5% APSs (HLA). Under heat stress, APSs increased the egg production rate and number of small white follicles, improved the yolk color, and lowered the feed conversion ratio. LPAB diets increased follicle-stimulating hormone, antioxidant enzyme activities, and anti-inflammatory cytokine activity and up-regulated related genes, whereas they reduced stress-related hormones, malondialdehyde concentrations, and triglyceride concentrations and down-regulated related genes. The addition of APSs enhanced immunoglobulin concentrations and cholesterol recovery and altered the expression of related genes. The study found that the adverse effects of high temperatures are directly related to oxidative stress. LAPB diets and APSs relatively alleviate these adverse effects. Therefore, the importance of feeding strategies such as LPAB diets and APSs for laying hens under heat stress conditions has been identified. Full article

Colloidal quantum dots (QDs) are semiconductor crystals a few nanometers in size. Due to their vibrant colors and unique photoluminescence (PL), QDs are widely utilized in displays, where barrier films provide essential shielding. However, one of the primary challenges of QD applications remains achieving sufficient robustness while keeping costs low. Over the past two decades, significant progress has been made in the encapsulation of QDs within silica matrices, aiming to preserve their original PL properties. Research efforts have evolved from bulk forms to thin films. Silica nanoparticles containing multiple embedded QDs have emerged as particularly promising candidates for practical applications. This review highlights recent advancements in silica-based QD encapsulation, incorporating findings from both the authors’ investigations and those of other research groups within the field. Silica glass possesses inherent shielding capabilities, but silane coupling agents such as (3-aminopropyl)trimethoxysilane and (3-mercaptopropyl)trimethoxysilane tend to negatively impact this functionality when they are used alone, partly because of the limited formation of a well-developed glass network structure. However, when judiciously controlled, they can serve as mediators between the QD surface and the surrounding pure silica glass matrix, helping to preserve PL properties and control the morphology of silica particles. This review discusses the potential for achieving exceptional shielding properties through sol–gel glass fabrication at low temperatures, utilizing both tetraethoxysilane and other silane coupling agents. Full article

Jabuticaba (Myrciaria jaboticaba (Vell.) O. Berg) peel is a native Brazilian fruit by-product recognized for its high anthocyanin (ANC) content and strong antioxidant potential, making it a valuable natural source for food applications. This study aimed to optimize the extraction and spray drying-based encapsulation of ANCs from the peels of Sabará jabuticaba. Extraction was performed using ethanol acidified with HCl (6 M) under varying conditions of pH (1.0–3.0), temperature (14–50 °C), and solvent volume (100–250 mL). The highest anthocyanin yield (328.13 mg/100 g dry basis) was achieved at pH 1.0, 50 °C, and 250 mL solvent volume. For encapsulation, gum arabic and maltodextrin were used as wall materials at different mass ratios (1:1, 1:2, 1:3, 1:4, 2:1, 3:1, and 4:1 w/w). The 1:2 ratio (gum arabic/maltodextrin) resulted in the highest retention of anthocyanins (315.37 mg/100 g dry basis), with encapsulation efficiency of approximately 96%, low water activity (0.27), and reduced moisture content (3.6%). These characteristics are essential for ensuring product stability during storage. The optimized anthocyanin-rich microparticles present promising potential for application as natural colorants and functional ingredients in food formulations or as antioxidant carriers in pharmaceutical products. Full article

Green synthesis of copper oxide (CuO) nanoparticles offers a sustainable alternative to conventional chemical methods that often involve toxic reagents and harsh conditions. This study investigates the use of Tithonia diversifolia, an invasive species in Sri Lanka, as a bioreductant for the eco-friendly fabrication of CuO nanoparticles. Using copper sulfate (CuSO₄·5H₂O) as a precursor, eight treatments were conducted by varying precursor concentration, temperature, and reaction time to determine optimal conditions. A visible color change in the reaction mixture initially indicated nanoparticle formation. Among all the conditions, treatment T4 (5 mM CuSO₄, 80 °C, 2 h) yielded the most favorable results in terms of stability, morphology, and crystallinity. UV-Vis spectroscopic analysis confirmed the synthesis, with absorbance peaks between 265 and 285 nm. FTIR analysis revealed organic functional groups and characteristic metal–oxygen vibrations in the fingerprint region (500–650 cm⁻¹), confirming formation. SEM imaging showed that particles were mainly spherical to polygonal, averaging 125–150 nm. However, dynamic light scattering showed larger diameters (~240 nm) due to surface capping agents. Zeta potential values ranged from −16.0 to −28.0 mV, indicating stability. XRD data revealed partial crystallinity with CuO-specific peaks. These findings support the potential of T. diversifolia in green nanoparticle synthesis, suggesting a low-cost, eco-conscious strategy for future applications. Full article

We present a framework that aims to investigate the role of thermal fluctuations in matter composition and color superconductivity in the nucleation of three-flavor deconfined quark matter in the typical conditions of high-energy astrophysical systems related to compact stars. It is usually assumed that the flavor composition is locally fixed during the formation of the first seed of deconfined quark matter, since a weak interaction acts too slowly to re-equilibrate flavors. However, the matter composition fluctuates around its average equilibrium values at the typical temperatures of high-energy astrophysical processes. Here, we extend our previous two-flavor nucleation formalism to a three-flavor case. We develop a thermodynamic framework incorporating finite-size effects and thermal fluctuations in the local composition to compute the nucleation probability as the product of droplet formation and composition fluctuation rates. Moreover, we discuss the role of color superconductivity in nucleation, arguing that it can play a role only in systems larger than the typical coherence length of diquark pairs. We found that thermal fluctuations in the matter composition led to lowering the potential barrier between the metastable hadronic phase and the stable quark phase. Moreover, the formation of diquark pairs reduced the critical radius and thus the potential barrier in the low baryon density and temperature regime. Full article

Anthraquinone acid dyes are widely used in dyeing polyamide due to their good exhaustion and brightness. While ionic interactions primarily govern dye–fiber bonding, the molecular weight (Mw) of these dyes can significantly influence migration, apparent color strength, and fastness behavior. This study offers comparative insight into how the Mw of structurally similar anthraquinone acid dyes impacts their diffusion, fixation, and functional outcomes (e.g., UV protection) on polyamide 6 fabric, using Acid Blue 260 (Mw~564) and Acid Blue 127:1 (Mw~845) as representative low- and high-Mw dyes. The effects of dye concentration, pH, and temperature on color strength (K/S) were evaluated, migration index and zeta potential were measured, and UV protection factor (UPF) and FTIR analyses were used to assess fabric functionality. Results showed that the lower-Mw dye exhibited higher migration tendency, particularly at increased dye concentrations, while the higher-Mw dye demonstrated greater color strength and superior wash fastness. Additionally, improved UPF ratings were associated with higher-Mw dye due to enhanced light absorption. These findings offer practical insights for optimizing acid dye selection in polyamide coloration to balance color performance and functional attributes. Full article

To address the high drying temperature, low yield, and low coating rate that characterize traditional chitosan/gum arabic microcapsules, this study used chitosan/sodium tripolyphosphate (STPP) ionic crosslinking to construct a composite wall, combined with optimized emulsifier compounding (T-80/SDBS), to prepare tung oil self-healing microcapsules. Orthogonal testing determined the following optimal parameters: a core-to-wall ratio of 2.0:1.0, a T-80/SDBS ratio of 4.0:6.0 (HLB = 12.383), an STPP concentration of 4%, and a spray-drying temperature of 120 °C. With these parameters, a yield of 42.91% and coating rate of 68.50% were achieved. The microcapsules were spherical (1–6 μm), with chitosan–STPP electrostatic interactions forming a dense wall. Adding 5% microcapsules to the UV topcoat enabled self-healing after 60 s UV curing: the scratch-healing rate reached 25.25% (width decreased from 11.13 μm to 8.32 μm), the elongation at break increased by 110% to 9.31%, the light transmission remained >82.50%, and the color difference (ΔE = 2.16) showed no significant change versus unmodified coating. Full article

Jackfruit seeds (Artocarpus heterophyllus Lam.) are a viable option for supporting a sustainable protein supply. The objective was to obtain protein powder from jackfruit seeds protein concentrate (JSPC) by spray drying. A central composite design was used; the independent variables were inlet temperature (110, 115, and 120 °C) and the solids of the JSPC solution (5, 7.5, and 10%). With the desirability function, the optimal drying parameters to maximize the process yield and achieve a low moisture content were 7.5% solids in the JSPC solution and an inlet temperature of 115 °C, resulting in a process yield of 71.51 ± 1.21%. Moisture (5.33 ± 0.11%), water activity (0.15 ± 0.02), bulk density (0.40 ± 0.01 g/mL), and color (L*: 70.56 ± 0.38, a*: 7.80 ± 0.11 and b*: 15.18 ± 0.15) were measured; these parameters are within the allowed ranges for stable food powders. Hydrosolubility (82.46 ± 1.68%), foaming capacity (48.33 ± 1.66%), and emulsifying activity (105.74 ± 10.20 m²/g) were evaluated. Glass transition temperature (129.49 °C) of the JSPC powder enables the establishment of optimal storage and processing conditions for the protein. JSPC powder could be applied to the elaboration of food products with nutritional and functional value. Full article

Chlorophyll-a (Chla) and suspended particulate matter (SPM) are key indicators of water quality, playing critical roles in understanding marine biogeochemical processes and ecosystem health. Although satellite data from the Chinese Ocean Color and Temperature Scanner (COCTS) onboard the Haiyang-1C/D satellites is freely available, there has been limited validation of its standard Chla and SPM products. This study is a first step to address this gap by evaluating COCTS-derived Chla and SPM products against in situ measurements in French coastal waters. The matchup analysis showed robust performance for the Chla product, with a median symmetric accuracy (MSA) of 50.46% over a dynamic range of 0.13–4.31 mg·m⁻³ (n = 24, Bias = 41.11%, Slope = 0.93). In contrast, the SPM product showed significant limitations, particularly in turbid waters, despite a reasonable performance in the matchup exercise, with an MSA of 45.86% within a range of 0.18–10.52 g·m⁻³ (n = 23, Bias = −14.59%, Slope = 2.29). A comparison with another SPM model and Moderate Resolution Imaging Spectroradiometer (MODIS) products showed that the COCTS standard algorithm tends to overestimate SPM and suggests that the issue does not originate from the input radiometric data. This study provides the first regional assessment of COCTS Chla and SPM products in European coastal waters. The findings highlight the need for algorithm refinement to improve the reliability of COCTS SPM products, while the Chla product demonstrates suitability for water quality monitoring in low to moderate Chla concentrations. Future studies should focus on the validation of COCTS ocean color products in more diverse waters. Full article

During a volcanic eruption, a large volume of pyroclastic material can be deposited on the roads and roofs of the urban areas near volcanoes. The use of volcanic ash as an additive for the manufacture of bricks provides a solution to the disposal of part of this natural residue and reduces the depletion of a non-renewable natural resource, clayey soil, which brings some environmental and economic advantages. The pore system, compactness, uniaxial compression strength, thermal conductivity, color and durability of bricks without and with the addition of volcanic ash were evaluated through hydric tests, mercury intrusion porosimetry, ultrasound, uniaxial compression tests, IR thermography, spectrophotometry and salt crystallization tests. The purpose of this research is to determine the feasibility of adding 10, 20 and 30% by weight of volcanic ash from La Palma (Canary Islands, Spain) in two grain sizes to produce bricks fired at 800, 950 and 1100 °C. The novelty of this study is to use two sizes of volcanic ash and fire the samples at 1100 °C, which is close to the liquidus temperature of basaltic magmas and allows a high degree of interaction between the volcanic ash and the brick matrix. The addition of fine volcanic ash was found to decrease the porosity of the bricks, although the use of high percentages of coarse volcanic ash resulted in bricks with almost the same porosity as the control samples. The volcanic ash acted as a filler, reducing the number of small pores in the bricks. The presence of vesicles in the volcanic ash reduced the compressive strength and the compactness of the bricks with additives. This reduction was more evident in bricks manufactured with 30% of coarse volcanic ash and fired at 800 and 950 °C, although they still reached the minimum resistance required for their use in construction. No significant differences in thermal conductivity were noticed between the bricks with and without volcanic ash additives, which is crucial in terms of energy savings and the construction of sustainable buildings. At 1100 °C the volcanic ash changed in color from black to red. As a result, the additive blended in better with the matrix of bricks fired at 1100 °C than in those fired at 800 and 950 °C. The bricks with and without volcanic ash and fired at 1100 °C remained intact after the salt crystallization tests. Less salt crystallized in the bricks with volcanic ash and fired at 800 and 950 °C than in the samples without additives, although their low compressive strength made them susceptible to decay. Full article

The visual colorimetric sensing of total volatile basic nitrogen (TVB-N) allows for convenient dynamic monitoring of animal-derived food freshness to ensure food safety. The agarose hydrogel loaded with the natural dye juglone (Jug@AG) prepared in this study exhibits visible multicolor changes from yellow to grayish-yellow and then to brownish with increasing TVB-N gas concentration, achieving sensitive detection of TVB-N gas at concentrations as low as 0.05 mg/dm³ within 8 min. The minimum observable amounts of TVB-N in spiked pork and fish samples are 8.43 mg/100 g and 8.27 mg/100 g, respectively, indicating that the Jug@AG hydrogel possesses sensitive colorimetric sensing capability in practical applications. The Jug@AG hydrogel also shows significant changes in color difference value (∆C) under both room temperature (25 °C) and cold storage (4 °C) conditions, with the changing trends of ∆C showing consistency with the measured TVB-N and total viable counts (TVC) during the transition of pork and fish samples from freshness to early spoilage and then to spoilage. The results indicate that the Jug@AG hydrogel can be used as a colorimetric sensor to achieve real-time dynamic freshness monitoring of animal-derived food. Full article

Solar power generation is rapidly emerging within renewable energy due to its cost-effectiveness and ease of deployment. However, improper inspection and maintenance lead to significant damage from unnoticed solar hotspots. Even with inspections, factors like shadows, dust, and shading cause localized heat, mimicking hotspot behavior. This study emphasizes interpretability and efficiency, identifying key predictive features through feature-level and What-if Analysis. It evaluates model training and inference times to assess effectiveness in resource-limited environments, aiming to balance accuracy, generalization, and efficiency. Using Unmanned Aerial Vehicle (UAV)-acquired thermal images from five datasets, the study compares five Machine Learning (ML) models and five Deep Learning (DL) models. Explainable AI (XAI) techniques guide the analysis, with a particular focus on MPEG (Moving Picture Experts Group)-7 features for hotspot discrimination, supported by statistical validation. Medium Gaussian SVM achieved the best trade-off, with 99.3% accuracy and 18 s inference time. Feature analysis revealed blue chrominance as a strong early indicator of hotspot detection. Statistical validation across datasets confirmed the discriminative strength of MPEG-7 features. This study revisits the assumption that DL models are inherently superior, presenting an interpretable alternative for hotspot detection; highlighting the potential impact of domain mismatch. Model-level insight shows that both absolute and relative temperature variations are important in solar panel inspections. The relative decrease in “blueness” provides a crucial early indication of faults, especially in low-contrast thermal images where distinguishing normal warm areas from actual hotspot is difficult. Feature-level insight highlights how subtle changes in color composition, particularly reductions in blue components, serve as early indicators of developing anomalies. Full article