Search Results (1,690)

This work presents the design, modeling, and experimental validation of an innovative, highly autonomous, and economically viable photovoltaic solar cooker, integrating a robust battery storage system. The system combines 1200 Wp photovoltaic panels, a control block with DC/DC power converters and digital control for intelligent energy management, and a thermally insulated heating plate equipped with two resistors. The objective of the system is to reduce dependence on conventional fuels while overcoming the limitations of existing solar cookers, particularly insufficient cooking temperatures, the need for continuous solar orientation, and significant thermal losses. The optimization of thermal insulation using a ceramic fiber and glass wool configuration significantly reduces heat losses and increases the thermal efficiency to 64%, nearly double that of the non-insulated case (34%). This improvement enables cooking temperatures of 100–122 °C, heating element surface temperatures of 185–464 °C, and fast cooking times ranging from 20 to 58 min, depending on the prepared dish. Thermal modeling takes into account sheet metal, strengths, and food. The experimental results show excellent agreement between simulation and measurements (deviation < 5%), and high converter efficiencies (84–97%). The integration of the batteries guarantees an autonomy of 6 to 12 days and a very low depth of discharge (1–3%), allowing continuous cooking even without direct solar radiation. Crucially, the techno-economic analysis confirmed the system’s strong market competitiveness. Despite an Initial Investment Cost (CAPEX) of USD 1141.2, the high performance and low operational expenditure lead to a highly favorable Return on Investment (ROI) of only 4.31 years. Compared to existing conventional and solar cookers, the developed system offers superior energy efficiency and optimized cooking times, and demonstrates rapid profitability. This makes it a sustainable, reliable, and energy-efficient home solution, representing a major technological leap for domestic cooking in rural areas. Full article

The rapid expansion of China’s photovoltaic (PV) industry has led to a significant increase in decommissioned PV modules. To address the high energy consumption and environmental impact of traditional recycling techniques, this study proposes a novel method that integrates DMPU solvent recycling with pyrolysis for recovering PV cell sheets. DMPU, an organic solvent with low volatility, non-toxicity, and excellent recyclability, was used in this study. The effects of temperature and treatment duration on the structural integrity of silicon cell sheets were systematically evaluated, establishing optimal parameters: immersion in DMPU at 200 °C for 60 min, followed by pyrolysis at 480 °C for 60 min. A case study was conducted on a small-scale recycling facility with a daily processing capacity of 200 standard PV panels, encompassing system boundaries such as transportation, pretreatment, and pyrolysis. The recycling process consumed 2.14 × 10⁹ kJ of energy annually, reducing CO₂ emissions by 9357.2 tons. Compared to conventional methods such as pyrolysis, mechanical dismantling, and chemical dissolution, the proposed approach employing a green, recyclable solvent markedly reduces energy consumption and carbon emissions, offering notable environmental benefits. Full article

Heavy metals released from industrial effluents accumulate in the human body through the ecosystem, causing several health disorders. This study investigated the removal of cadmium (Cd²⁺) using Micellar-Enhanced Ultrafiltration (MEUF). This study employed sodium dodecyl sulfate (SDS) and flat-sheet polyethersulfone (PES) ultrafiltration membranes to separate Cd²⁺ ions from lab-simulated water. The experiments involved examining the removal efficiency of membranes without SDS usage, optimizing SDS concentration for Cd²⁺ removal, and evaluating the long-term membrane performance. Other parameters include analyzing the removal percentage of varying Cd²⁺ at constant SDS dosage, examining the effect of pH, and electrolyte concentrations on the removal of Cd²⁺. Several analytical characterizations were performed, such as FT-IR, and SEM. The FTIR confirms the aromatic C-H group at 620–867 cm⁻¹, the sulfone group at 1100–1200 cm⁻¹, and the ether group at 1230–1270 cm⁻¹ and the SEM analysis indicates no significant fouling, which aligns with the stable flux observed over time. The result showed that the optimum SDS concentration for Cd²⁺ removal was 1 Critical Micellar Concentration (CMC), achieving over 99% removal. The presence of an electrolyte decreased Cd²⁺ removal efficiency, while the pH (3 to 9) had no effect on removal. Our findings suggest that the SDS-aided ultrafiltration process is suitable for eliminating Cd²⁺ from wastewater. Full article

Pulse current-assisted flexible granular medium forming is a promising approach for manufacturing complex thin-walled components from difficult-to-deform Ti₂AlNb-based alloys. In this study, the electro-thermo-mechanical deformation behavior of Ti₂AlNb sheets is investigated through pulse current-assisted uniaxial tensile tests, microstructural characterization, and finite element simulations. The influences of pulse current intensity and strain rate on flow behavior, fracture characteristics, and phase evolution are clarified, and an effective forming window is identified. Numerical simulations are employed to analyze the role of granular medium friction in material flow and wall thickness distribution, providing guidance for forming box-shaped components. The results demonstrate that forming at approximately 950 °C with a strain rate of 0.001 s⁻¹ reduces deformation resistance, while enhanced tangential interaction between the granular medium and the sheet improves wall thickness uniformity. This study provides a feasible processing route and practical guidelines for the fabrication of complex Ti₂AlNb sheet components. Full article

This research reports the development of photocatalytic active composites for hydrogen evolution obtained through high-energy mechanical milling of a mixture of the organic semiconductor g-C₃N₄ (CN) and the metal–organic framework ZIF-67. These composites, called CNZ-x (X = mass proportion of ZIF-67), were characterized using powder XRD, which showed that the crystalline phases of both the g-C₃N₄ and ZIF-67 precursors are present in the composites. SEM was used to determine the morphology, revealing that the ZIF-67 octahedral particles adhere to the surface of the CN sheets due to the intimate interfacial contact induced by high-energy mechanical grinding. The results of the photocatalytic evolution of H₂ indicate that the CNZ-50 composite produced 261 μmol g⁻¹ of H₂, which is higher than the 229.5 and 124 μmol g⁻¹ produced by the precursors ZIF-67 and CN, respectively. The higher efficiency in H₂ evolution is due to the composite having better electron-hole separation than the precursor materials. Full article

rGO/ZnO composites have been widely studied for use as toxic gas sensors due to the synergistic effect between the materials and the reduction in sensor operating temperature promoted by rGO. However, few studies have employed rGO/ZnO sensors for ozone detection, as graphene materials are oxidized and/or degraded when exposed to ozone. This paper reports on a study of ZnO/rGO/ZnO-based sensors with different ZnO NP morphologies for ozone sensing. ZnO nanoparticles with needle-like and donut-like morphologies were synthesized by the precipitation method, and bare ZnO and ZnO/rGO/ZnO composite sensors were fabricated by layer-deposition of ZnO and/or rGO via drop-casting, forming a “sandwiched” structure that protects the rGO sheets. Bare ZnO and ZnO/rGO/ZnO composites were analyzed by varying the temperature from 200 to 300 °C. The ZnO/rGO/ZnO sensor provided a high 13.3 response (R_gas/R_air) and recovery times of 442 s and 253 s, respectively, for 50 ppb of O₃, as well as high selectivity to ozone gas compared to CO, NH₃, and NO₂ gases. No oxidation or degradation of the sensor was observed during ozone detection measurements, indicating that the adopted manufacturing methodology was successful. Full article

To test whether fructooligosaccharide (FOS) and inulin (INU) molecules can improve the hardness of cooked rice through forming a hydrogel network, we added FOS or INU at 0%, 3%, 5%, 7%, and 10% concentrations to two cooking japonica rice and compared the cooking and textural parameters, the pasting, thermal, and thermo-mechanical properties, and the microstructure of the cooked rice. General Linear Model Univariate (GLMU) analysis revealed that, compared with no oligofructose addition, both FOS and INU addition reduced the rice cooking time and increased the gruel solid loss. The addition of these dietary fibers (DFs) to cooking rice lowered the hardness, adhesiveness, springiness, gumminess, and chewiness of the rice, but maintained the cohesiveness and increased the resilience. Compared with no oligofructose addition, FOS and INU addition improved the smell, taste, and total sensory score of cooked rice. The addition of these DFs significantly decreased the trough, peak, final, breakdown, and setback viscosities, but increased the pasting temperature and peak time. Both FOS and INU addition decreased the enthalpy of gelatinization but increased the peak and conclusion temperature of gelatinization of rice flour paste. After the retrograded flour pastes were kept at 4 °C for 21 days, both FOS and INU significantly increased amylopectin aging compared with no oligofructose addition. The FOS-added and INU-added rice doughs had a higher dough development time and stability time, gelatinization peak torque, setback torque, and gelatinization speed, with a lower protein weakening degree, amylase activity, breakdown torque, heating speed, and enzymatic hydrolysis speed. Compared with no oligofructose addition, both FOS and INU addition reduced the amorphous region of starch and β-sheet percentage, but increased the percentages of random coils, α-helixes, and β-turns in cooked rice. Principal component analysis (PCA) further demonstrated that the gruel solid loss, cooked rice hardness, chewiness, gumminess, taste, and the peak, trough, breakdown, final, and setback viscosities were sensitive parameters for evaluating the effects of species and the amount of oligofructose addition on rice quality. The microstructure showed that FOS or INU addition induced thickening of the matrix walls and an increase in the pore size, forming a soft and evenly swollen structure. These results suggest that FOS or INU addition inhibits amylose recrystallization but maintains amylopectin recrystallization in cooked rice, with INU addition producing greater improvements in the texture and sensory scores of cooked rice compared withFOS addition. This study provides evidence of the advantages of adding DFs and probiotics such as INU and FOS to cooked rice. Full article

Leaks in ponds are a problem due to the loss of water resources, although the problem is greater when the ponds store livestock or agricultural waste (slurry or wastewater), in which case there is a risk of hydrogeological contamination of the environment. The proposed leak detection system is based on distributed temperature sensing (DTS) with hybrid fiber optics using the Raman effect. Using active detection techniques, i.e., applying a specific amount of electrical power to the copper wires that form part of the hybrid cable, it is possible to increase the temperature along the fiber and measure the thermal increments along it, detecting and locating the point of leakage. To validate the system, a full-scale prototype reservoir (25 m × 10 m × 3.5 m) was built, equipped with mechanisms to simulate leaks under the impermeable sheet that retains the reservoir’s contents. For environmental reasons, the tests were carried out with clean water. The results of the leak simulation showed significant differences in temperature increases due to the electrical pulse in the areas affected by the simulated leak (1 °C increase) and the areas not affected (5 °C increase). This technology, which uses hybrid fiber optics and a low-cost sensor, can be applied not only to ponds, but also to other types of infrastructure that store or retain liquids, such as dams, where it has already been tested, to measure groundwater flow, etc. Full article

Differential speed rolling (DSR) has been recognized as a unique processing technique in recent years, which has been used to plastically deform Mg-based alloys and to investigate the role of dynamic recrystallization (DRX) and its influence on both microstructure and mechanical properties. In this study, Mg–2Al–0.5Ca–0.5Mn (AXM20504) was solution-heat-treated (T4 condition) and subjected to single-pass DSR at both 20 and 40% thickness reductions, followed by post-annealing at temperatures of 350, 400, and 450 °C for the durations of 20, 40, and 60 min to evaluate the onset and development of static recrystallization (SRX) and its overall effect on the formability of Mg-based alloys. The results demonstrate how post-annealing yields nearly complete SRX at 400 °C for 60 min and 450 °C for 40 min with a significant improvement in ductility, increasing from 5% to 12% while maintaining an average tensile strength above 200 MPa. Thus, the improvement in mechanical properties demonstrates that post-annealing can deliver significant potential in terms of the enhanced formability of Mg alloys used in sheet metal forming applications. Full article

Background and Clinical Significance: We present an 85-year-old male case of primary hepatic SCC manifesting as multiple liver nodules with atypical imaging findings. Case Presentation: The patient was negative for hepatitis B surface antigen and hepatitis C virus antibody. Serum tumor markers were all within normal limits. Contrast-enhanced ultrasonography with perflubutane demonstrated hypervascular nodules in the early vascular phase, early washout in the portal phase, and a defect in the postvascular phase (10 mm in S5 and 25 mm in S6). Histopathological examination revealed irregularly shaped tumor cells with large hyperchromatic nuclei and basophilic cytoplasm, surrounded by dense fibrous stroma forming cords, solid nests, and sheet-like structures. Immunohistochemical analysis showed positivity for AE1/AE3, p40, CK5/6, c-kit, and NCAM. Conclusions: The lesions were diagnosed as primary hepatic squamous cell carcinoma and suggested the possible involvement of hepatic progenitor cells, supporting the hypothesis of de novo carcinogenesis. Full article

The utilization of metal roofing as natural air terminals is a standard practice in lightning protection; however, the risk of thermal perforation and subsequent ignition of internal hazardous atmospheres remains a critical safety concern. While current standards (e.g., IEC 62305) primarily focus on material thickness and total charge (Q), this study demonstrates that these parameters alone are insufficient for predicting burn-through failure. We present a comprehensive electrothermal analysis based on the method of images to simulate three-dimensional heat diffusion in finite-thickness plates (0.5–7 mm) made of aluminum, copper, and steel. Unlike simplified 1D models, our approach considers the spatial distribution of the heat source and the varying depth of the thermal penetration. The results confirm that the continuing current component ($Q_{long}\approx 200$ C) is the primary driver of volumetric melting. Crucially, the sensitivity analysis reveals that the lightning channel radius ($r_{mbo}$) acts as a governing factor for perforation risk; a reduction in the lightning channel radius from 5 mm to 2 mm can shift the outcome from minor surface heating to complete perforation for thin sheets ($0.5$ mm), even under identical charge conditions. This paper identifies a “safety gap” in current engineering practices, demonstrating that neglecting this parameter constriction effect results in an underestimation of the thermal threat. The proposed analytical model provides a precise tool for determining the safety margins of natural air terminals, offering direct applicability for designing lightning protection systems in high-risk industrial facilities. Full article

α-L-Rhamnosidase can specifically hydrolyze plant natural glycosides and holds significant potential for biocatalytic applications in functional foods, healthy products, and pharmaceutical industries. Herein, a novel thermophilic and acidophilic α-L-rhamnosidase TsRha from Thermotoga sp. 2812B belonging to glycoside hydrolase family 78 was identified by genome mining and comprehensively characterized by bioinformatics, computer-aided structural analysis, and biochemical characterization. TsRha possesses a domain architecture comprising one catalytic (α/α)₆-barrel domain and four β-sheet domains. TsRha displayed optimal activity at 90 °C and pH 5.0, remarkable thermostability at 80 °C, and considerable tolerance to organic solvents. TsRha exhibited broad substrate selectivity and might efficiently hydrolyze a series of natural flavonoid glycosides with various glycosidic bonds (α-1, α-1, 2, α-1, 6) from different aglycone subgroups (flavanone, flavone, flavonol, and dihydrochalcone). Moreover, it demonstrated high conversion efficiencies toward a variety of natural flavonoid diglycosides rutin, naringin, naringin dihydrochalcone, hesperidin, and troxerutin, achieving ≥99.1% conversion within 20~100 min. The excellent properties including high activity, thermophilicity, acidophilicity, good thermostability, broad substrate spectrum will make the α-L-rhamnosidase TsRha a promising biocatalyst for the efficient production of rare and high-value flavonoid glucosides with improved bioavailability and bioactivity. Full article

This study investigates coke formation, structure, and combustion behaviors in paraffin-based Menggulin and naphthenic-based Xinjiang heavy oils under simulated in-situ combustion (ISC) conditions (350 °C, 450 °C), utilizing GC-MS, SEM, ¹³C ss-NMR, and TG-DSC. The results indicate that the crude oil composition determines the coking mechanisms: Xinjiang oil, rich in cyclic hydrocarbons and O/N/S heteroatoms, forms high-yield, compact, sheet- or block-like coke at 350 °C via π–π stacking. In contrast, Menggulin oil, composed primarily of long-chain alkanes, yields loose coke at 350 °C but produces dense, highly aromatized coke at 450 °C, which corresponds to the critical alkane cracking temperature, through intense cracking–polymerization. Temperature differentially regulates oxidative processes, thereby shaping the divergent functional group distributions. Correlations between coke structure and combustion properties reveal that oxygenated/aliphatic-rich cokes exhibit high reactivity, whereas aromatized cokes release more heat. These findings provide guidance for ISC optimization, suggesting that sufficient high-temperature energy is required for paraffinic oils while medium-temperature oxidation regulation is suitable for naphthenic oils. This work advances the theory of ISC coke formation and supports enhanced recovery of heavy oils. Full article

Galvanized steel sheets are vital anti-corrosion materials, yet their surface quality is prone to defects that impact performance. Manual inspection is inefficient, while conventional machine vision struggles with complex, small-scale defects in industrial settings. Although deep learning offers promising solutions, standard object detection models like YOLOv5 (which is short for ‘You Only Look Once’) exhibit limitations in handling the subtle textures, scale variations, and reflective surfaces characteristic of galvanized sheet defects. To address these challenges, this paper proposes S-C-B-YOLO, an enhanced detection model based on YOLOv5. First, a Squeeze-and-Excitation (SE) attention mechanism is integrated into the deep layers of the backbone network to adaptively recalibrate channel-wise features, improving focus on defect-relevant information. Second, a Transformer block is combined with a C3 module to form a C3TR module, enhancing the model’s ability to capture global contextual relationships for irregular defects. Finally, the original path aggregation network (PANet) is replaced with a bidirectional feature pyramid network (Bi-FPN) to facilitate more efficient multi-scale feature fusion, significantly boosting sensitivity to small defects. Extensive experiments on a dedicated galvanized sheet defect dataset show that S-C-B-YOLO achieves a mean average precision (mAP@0.5) of 92.6% and an inference speed of 62 FPS, outperforming several baseline models including YOLOv3, YOLOv7, and Faster R-CNN. The proposed model demonstrates a favorable balance between accuracy and speed, offering a robust and practical solution for automated, real-time defect inspection in galvanized steel production. Full article

Formability testing is a fundamental method for determining sheet metal’s susceptibility to deep drawing operations. This article presents the results of formability analysis of several batches of 0.7 mm thick cold-rolled DX56D+Z100-M-C-O steel sheets. As part of the preliminary tests, mechanical properties of the tested steel sheets were determined. The ARAMIS digital image correlation system was used to determine the formability of sheet metal during the hemispherical punch stretching test. The stretching tests were conducted over a wide range of strain rate variations between 2 mm/min and 17 mm/min. A total of 540 individual geometry measurements were taken to analyze the test material’s formability. It was observed that with increasing strain rate, the strength properties increased, while the plastic properties decreased. From the perspective of formability, the margin of plasticity (the ratio of yield strength to tensile strength) deteriorated with increasing strain rate in tensile tests. Forming limit curves revealed that at higher strain rates, the metal sheet’s formability decreased. A reduction in the safety margins with an increasing hemispherical punch stretching test speed was also observed. Full article