Search Results (12,011)

In this study, the insufficient ability of tartary buckwheat protein (TBP) to stabilize Pickering emulsions was addressed by preparing TBP–sodium alginate (SA) composite particles via cross-linking and systematic optimization of the preparation parameters. The results showed that at a pH of 9.0 with 1.0% (w/v) TBP and 0.2% (w/v) SA, the zeta potential of the prepared TBP–SA composite particles was significantly more negative, and the particle size was significantly larger, than those of TBP, while emulsifying activity index and emulsifying stability index increased to 53.76 m²/g and 78.78%, respectively. Scanning electron microscopy confirmed the formation of a dense network structure; differential scanning calorimetry revealed a thermal denaturation temperature of 83 °C. Fourier transform infrared spectroscopy and surface hydrophobicity results indicated that the complex was formed primarily through hydrogen bonding and hydrophobic interactions between TBP and SA, which induced conformational changes in the protein. The Pickering emulsion prepared with 5% (w/v) TBP–SA composite particles and 60% (φ) oil phase was stable during 4-month storage, at a high temperature of 75 °C, high salt conditions of 600 mM, and pH of 3.0–9.0. The stabilization mechanisms may involve: (1) strong electrostatic repulsion provided by the highly negative zeta potential; (2) steric hindrance and mechanical strength imparted by the dense interfacial network; and (3) restriction of droplet mobility due to SA-induced gelation. Full article

The paper explores the application of heat pipes in thermal management for efficient heat dissipation, particularly in electrical equipment with high heat loads. Heat pipes are devices that transfer heat with high efficiency through the phase transition of the working medium (e.g., water, alcohol, ammonia) between the evaporator and the condenser, while they have no moving parts and are distinguished by their simplicity of construction. Different types of heat pipes—gravity, capillary, and closed loop (thermosiphon loop)—are suitable according to specific applications and requirements for the working position, temperature range, and condensate return transport. An example of an effective application is the removal of heat from the internal winding of a static energy converter transformer, where the use of a gravity heat pipe has enabled effective cooling even through epoxy insulation and kept the winding temperature below 80 °C. Other applications include the cooling of mounting plates, power transistors, and airtight cooling of electrical enclosures with the ability to dissipate lost thermal power in the order of 102 to 103 W. A significant advantage of heat pipes is also the ability to dust-tightly seal equipment and prevent the build-up of dirt, thereby increasing the reliability of the electronics. In the field of environmental technology, systems have been designed to reduce the radiant power of fireplace inserts by up to 40%, or to divert their heat output of up to about 3 kW into hot water storage tanks, thus optimising the use of the heat produced and preventing overheating of the living space. The use of nanoparticles in the working substances (e.g., Al₂O₃ in water) makes it possible to intensify the boiling process and thus increase the heat transfer intensity by up to 30% compared to pure water. The results of the presented research confirm the versatility and high efficiency of the use of heat pipes for modern cooling requirements in electronics and environmental engineering. Full article

In response to the increasing demand for environmentally friendly and cost-effective adsorbents in wastewater treatment, this study reports the green synthesis, characterization, and application of a magnetic epichlorohydrin Rosa canina (m-ECH-RC) nanocomposite for removing Safranin O (SO), a commonly used cationic dye in textile effluents. The synthesized material was characterized using Brunauer–Emmett–Teller (BET), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray diffraction (XRD), and zeta potential analyses to reveal its surface morphology, pore structure, functional groups, crystallinity, and colloidal stability. Adsorption performance was systematically tested under various conditions, including pH, adsorbent dose, contact time, ionic strength, and initial dye concentration. Kinetic analyses revealed that the adsorption process of Safranin O dye mainly obeys pseudo-second-order kinetics, but intraparticle and film diffusion also contribute to the process. As a result of the Isotherm analysis, it was found that the adsorption process conformed to the Langmuir model. Testing on real textile wastewater samples demonstrated a removal efficiency of 75.09% under optimized conditions. Reusability experiments further revealed that the material maintained high adsorption–desorption performance for up to five cycles, emphasizing its potential for practical use. These findings suggest that m-ECH-RC is a viable and sustainable adsorbent for treating dye-laden industrial effluents. Full article

Recently, researchers have been focused on the recycling as well as transforming of bio-waste streams into a valuable resource. Banana peels are promising for such application, due to their wide availability. In this context, the integration of banana peel-derived biochar with environmentally benign magnetite has significantly broadened its potential applications as a solar photocatalyst compared to the conventional photocatalysts. The materials are mixed in varied proportions of Ban-Char500-Mag@-(0:1), Ban-Char500@Mag-(1:1) and Ban-Char500@Mag-(2:1) and characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM) augmented with dispersive X-ray spectroscopy (EDX). Such modification is leading to an improvement in its application as a solar photocatalyst using the photochemical solar collector facility. The study discusses the factors controlling acetaminophen removal from aqueous effluent within 30 min of solar illumination time. Furthermore, the highlighted optimum parameters are pH 3.0, using 10 mg/L of the Ban-Char500@Mag-(1:1) catalyst and 100 mg/L of the hydrogen peroxide as a Fenton combination system for removing a complete acetaminophen from wastewater (100% oxidation). Also, the temperature influence in the oxidation system is studied and the high temperature is unfavorable, which verifies that the reaction is exothermic in nature. The catalyst is signified as a sustainable (recoverable, recyclable and reusable) substance, and showed a 72% removal even though it was in the six cyclic uses. Further, the kinetic study is assessed, and the experimental results revealed the oxidation process is following the first-order kinetic reaction. Also, the kinetic–thermodynamic parameters of activation are investigated and it is confirmed that the oxidation is exothermic and non-spontaneous in nature. Full article

This study evaluated the effect of dietary supplementation with different levels of spray-dried phenolic compounds, extracted from olive mill wastewater, on the volatile compound profile of Caciotta cheese produced from cow’s milk. Thirty dairy cows were divided into three groups and fed diets containing 0% (C), 0.1% (T0.1), and 0.2% (T0.2) polyphenols on a dry matter basis. Milk from each group was used in three cheesemaking sessions, and 27 cheese samples ripened for 21 days were analyzed. Volatile compounds were extracted using solid phase microextraction (SPME) coupled with mass spectrometry, while the odour fingerprint was assessed using an electronic nose (PEN3). Principal Component Analysis (PCA) revealed a clear separation among groups, indicating distinct aromatic profiles associated with dietary polyphenol levels. In summary, incorporating by-products from olive mill wastewater into the diets of dairy cows can significantly affect the aroma of cheese. This approach represents a sustainable and innovative strategy that promotes waste valorization, reduces environmental impact, and supports circular economy principles by transforming a pollutant into a valuable additive. Full article

This study investigates iron acetylacetonate (Fe(acac)₃) as a catalyst for enhancing high-temperature oxidation (HTO) during in situ combustion (ISC) of heavy oil. Thermal analysis revealed that Fe(acac)₃ decomposes at 360 °C to form crystalline magnetite (Fe₃O₄). This transformation precedes the HTO regime. Differential scanning calorimetry demonstrated significantly intensified HTO reactions in catalytic systems, as peak temperatures were lower than those in non-catalytic reactions. Kinetic analysis showed that the catalyst reduces HTO activation energy by 15.6%, substantially increasing reaction rates across the HTO temperature range. X-ray powder diffraction confirmed that the mixed-valence Fe²⁺/Fe³⁺ configuration in the magnetite structure facilitates electron transfer during oxidation, enabling more complete combustion at lower temperatures. These findings represent a novel approach to catalyst design, from general activity to temperature-specific activation for a more stable and efficient in situ combustion process. Full article

As stability is one of the most important property of any system, studying it is paramount when performing a power-hardware-in-the-loop simulation in an experimental setup. To guarantee the proper operation of such a system, a thorough understanding of the critical issues regarding the dynamics of the power amplifier, the real-time simulated system and the hardware under test is required. Thus, this paper provides a detailed analysis of the correct design of the real-time simulation modeling for the secure and reliable execution of power-hardware-in-the-loop simulations involving power electronic devices in an experimental setup. Specifically, the stability region of a power-hardware-in-the-loop simulation in an experimental AC microgrid setup involving two parallel three-phase grid-following inverters with LCL filters is studied. Through experimental testing, the stability boundaries of the power-hardware-in-the-loop simulation in the experimental setup is determined, demonstrating a direct relationship between the short-circuit ratio of the utility grid and the cutoff frequency of the feedback current filter. Experimental evidence confirms the capability of the AC microgrid setup to achieve smooth transitions between diverse operating conditions and determine stability boundaries with parameter variations. This research provides practical design guidelines for modeling and the real-time simulation to ensure stability in the power-hardware-in-the-loop simulations in experimental setups involving actual grid-following inverters, specifically using an Opal-RT platform with a voltage-source ideal transformer model and parameter variations in the short-circuit ratio from 2 to 20, the line impedance ratio $X/R$ from 7 to 10, and the feedback-current-filter cutoff frequency from 100 to 1000 kHz. Full article

The influence of cold rolling deformation degree (15%, 30%, 45%, 60%, 75%, and 90%) on the microstructural evolution and the mechanical properties of type 347H austenitic heat-resistant steel was investigated using optical microscopy, X-ray diffraction, magnetic hysteresis loop measurement, transmission electron microscopy, and a hardness test. Two types of martensite formed in the deformed specimens, as thin ε-martensite in the cold-rolled steels when the deformation degree was less than 60%, and α′-martensite in the heavily cold-rolled steels when the deformation degree ranged from 60% to 90%. Furthermore, the amount of α′-martensite increases rapidly with the increase in the cold rolling deformation degree. Hence, 60% is considered as the critical point of cold rolling reduction for the formation of α′-martensite. If the specimen experienced a cold rolling reduction of 90%, ε-martensite was hardly observed, while the volume faction of the α′-martensite amounts to 25%. It is verified by the TEM observations that the α′-martensite is transformed from the austenitic matrix as well as the preformed ε-martensite. Full article

Accelerated artificial aging of zinc oxide (ZnO)-based acrylic artists’ paint, filled with calcium carbonate (CaCO₃) as an extender, was carried out for a total of 1963 h (~8 × 10⁷ lux·h), with assessments at specific intervals. The total color difference ΔE* was <2 (CIELab-76 system) over 1725 h of aging, while the human eye notices color change at ΔE* > 2. Oxidative degradation of organic components in the paint to form volatile products was revealed by attenuated total reflectance–Fourier transform infrared (ATR-FTIR) spectroscopy, micro-Raman spectroscopy, and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS). It appears that deep oxidation of organic intermediates and volatilization of organic matter may be responsible for the relatively small value of ΔE* color difference during aging of the samples. To elucidate the degradation pathways, principal component analysis (PCA) was applied to the spectral data, revealing: (1) the catalytic role of ZnO in accelerating photodegradation, (2) the Kolbe photoreaction, (3) the decomposition of the binder to form volatile degradation products, and (4) the relative photoinactivity of CaCO₃ compared with ZnO, showing slower degradation in areas with a higher CaCO₃ content compared with those dominated by ZnO. These results provide fundamental insights into formulation-specific degradation processes, offering practical guidance for the development of more durable artist paints and conservation strategies for acrylic artworks. Full article

Efficient routing optimization remains a pivotal challenge in Electronic Design Automation (EDA), as it profoundly influences circuit performance, power consumption, and manufacturing cost. The Rectilinear Steiner Minimum Tree (RSMT) problem plays a crucial role in this process by minimizing the routing length through the introduction of Steiner points. This paper proposes a reinforcement learning-driven RSMT construction model that incorporates a novel Selective Kernel Transformer Network (SKTNet) encoder to enhance feature representation. SKTNet integrates a Selective Kernel Convolution (SKConv) and an improved Macaron Transformer to improve multi-scale feature extraction and global topology modeling. Additionally, Self-Critical Sequence Training (SCST) is employed to optimize the policy by leveraging a greedy-decoded baseline sequence for the advantage computation. Experimental results demonstrate superior performance over state-of-the-art methods in wirelength optimization. Ablation studies further validate the contribution of this model, highlighting its effectiveness and scalability for routing. Full article

This study examines the pigments and materials used in Girolamo Romanino’s Musicians fresco (1537–1538), located in the Duomo Vecchio in Brescia, with the aim of identifying and analyzing the artist’s colour palette. Ten samples of the pictorial layer and mortar were collected from two frescoes and characterized using microscopic and spectroscopic techniques. Confocal laser scanning microscopy (CLSM) was used to define the best positions where single-point, spectroscopic techniques could be applied. Raman spectroscopy and micro-Fourier transform Infrared spectroscopy (micro-FTIR) were used to detect pigments and organic binders, respectively. X-ray powder diffraction (XRPD) provided additional insights into the mineral composition of the pigmenting layers, in combination with environmental scanning electron microscopy equipped with energy-dispersive spectroscopy (ESEM-EDS). The analysis revealed the use of traditional fresco pigments, including calcite, carbon black, ochres, and copper-based pigments. Smalt, manganese earths, and gold were also identified, reflecting Romanino’s approach to colour and material selection. Additionally, the detection of modern pigments such as titanium white and baryte points to restoration interventions, shedding light on the fresco’s conservation history. This research provides one of the most comprehensive analyses of pigments in Romanino’s works, contributing to a deeper understanding of his artistic practices and contemporary fresco techniques. Full article

Background: Hepatocellular carcinoma is associated with high mortality and increasing incidence. Sorafenib, a cornerstone of therapy for advanced hepatocellular carcinoma, presents certain disadvantages, including low bioavailability and poor water solubility. This work describes a new strategy for sorafenib-targeted delivery aimed at improving treatment efficiency and reducing side effects. Methods: Magnetic nanoparticles coated with azelaic acid were modified with aptamer molecules that specifically recognize human liver cancer cell line HepG2, ensuring specificity for the tumor tissue. The nanoparticles were further loaded with sorafenib. The obtained drug delivery system was extensively characterized using UV-Vis spectrophotometry, transmission electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, and electrochemical impedance spectroscopy. Results: The drug delivery system demonstrated a higher release of sorafenib at acidic pH compared to pH 7.4. The cell internalization of the bare and aptamer-modified magnetic nanoparticles was assessed in HepG2 and human normal foreskin fibroblasts BJ cell lines, demonstrating that the aptamer significantly enhances internalization in tumor cells, while having no impact on healthy cells. Conclusions: The sorafenib-modified nanoparticles exhibited excellent cytocompatibility with BJ cells across all tested concentrations, while showing cytotoxicity towards HepG2 cells at higher concentrations, confirming the selectivity of the system. Full article

In this study, the use of spent coffee waste as a green precursor of polyphenolic compounds, which are subsequently employed as reducing agents for the synthesis of zero-valent iron nanoparticles (nZVI) aimed at the efficient removal of dyes from aqueous systems, has been investigated. The nanoparticles, generated in situ in the presence of controlled amounts of hydrogen peroxide, were applied in the removal of organic dyes—including methylene blue, methyl orange, and orange G—through a heterogeneous Fenton-like catalytic process. The synthesized nZVI were thoroughly characterized by nitrogen adsorption at 77 K, scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), and powder X-ray diffraction (XRD). A statistical design of experiments and response surface methodology were employed to evaluate the effect of polyphenol, Fe(III), and H₂O₂ concentrations on dye removal efficiency. Results showed that under optimized conditions, a 100% removal efficiency could be achieved. This work highlights the potential of nZVI synthesized from agro-industrial waste through sustainable routes as an effective solution for water remediation, contributing to circular economy strategies and environmental protection. Full article

The long-term stability of grout-reinforced fractured rock masses in acidic groundwater environments after tunnel fires is critical for the safe operation of underground engineering. In this study, grouting reinforcement tests were performed on fractured diorite specimens using a high-strength fast-anchoring agent (HSFAA), and their mechanical degradation and microstructural evolution mechanisms were investigated under coupled high-temperature (25–1000 °C) and acidic corrosion (pH = 2) conditions. Multi-scale characterization techniques, including uniaxial compression strength (UCS) tests, X-ray computed tomography (CT), scanning electron microscopy (SEM), three-dimensional (3D) topographic scanning, and X-ray diffraction (XRD), were employed systematically. The results indicated that the synergistic thermo-acid interaction accelerated mineral dissolution and induced structural reorganization, resulting in surface whitening of specimens and decomposition of HSFAA hydration products. Increasing the prefabricated fracture angles (0–60°) amplified stress concentration at the grout–rock interface, resulting in a reduction of up to 69.46% in the peak strength of the specimens subjected to acid corrosion at 1000 °C. Acidic corrosion suppressed brittle disintegration observed in the uncorroded specimens at lower temperature (25–600 °C) by promoting energy dissipation through non-uniform notch formation, thereby shifting the failure modes from shear-dominated to tensile-shear hybrid modes. Quantitative CT analysis revealed a 34.64% reduction in crack volume (V_ca) for 1000 °C acid-corroded specimens compared to the control specimens at 25 °C. This reduction was attributed to high-temperature-induced ductility, which transformed macroscale crack propagation into microscale coalescence. These findings provide critical insights for assessing the durability of grouting reinforcement in post-fire tunnel rehabilitation and predicting the long-term stability of underground structures in chemically aggressive environments. Full article

Background: Cadmium (Cd) pollution poses a significant environmental challenge. Microbially induced carbonate precipitation (MICP), an advanced bioremediation approach, relies on the co-precipitation of soluble metals with the microbial hydrolysate from urea. This study isolated a urease-producing strain and evaluated its Cd remediation potential. Methods: The isolated strain UA7 was identified through 16S rDNA gene sequencing. Urease production was enhanced by optimizing the culture conditions, including temperature, dissolved oxygen levels—which were affected by the rotational speed and the design of the Erlenmeyer flask, and the concentration of urea added. Its Cd remediation efficacy was assessed both in water and soil. Results: UA7 was identified as Lysinibacillus sp., achieving peak urease activity of 188 U/mL. The immobilization rates of soluble Cd reached as high as 99.61% and 63.37%, respectively, at initial concentrations of 2000 mg/L in water and 50 mg/kg in soil. The mechanism of Cd immobilization by strain UA7 via MICP was confirmed by the microstructure of the immobilized products with attached bacteria, characteristic absorption peaks, and the formed compound Ca_0.67Cd_0.33CO₃, which were analyzed using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The Cd-remediation effect of strain UA7, which reduces lodging in wheat plants, prevents the thinning and yellowing of stems and leaves, and hinders the transition of soluble Cd to the above-ground parts of the plant, was also demonstrated in a pot experiment. Conclusions: Therefore, Lysinibacillus sp. UA7 exhibited high potential for efficiently remediating contaminated Cd. Full article