Search Results (1,556)

Minimum quantity lubrication (MQL) is a promising green technology for high-speed milling of GH4169. However, the full-chain oil mist penetration mechanism remains unclear, limiting precise parameter regulation. Based on a cross-scale mechanism, this study develops a semi-empirical oil mist penetration efficiency model coupling four key parameters and conducts single-factor and orthogonal high-speed milling experiments to validate the model and analyze the regulation mechanism using milling force and surface roughness. The experimental results show relative deviations below 6%, demonstrating good model validity and robustness. The influence hierarchy is spindle speed > nozzle orientation > nozzle angle > nozzle distance. Spindle speed and nozzle orientation are strongly coupled dominant parameters with a “drive-adaptation” mechanism, while nozzle distance and nozzle angle are weakly coupled, only notable under extreme conditions. The optimal parameters obtained via BP neural network and NSGA-II are nozzle orientation −X, angle 22.43°, distance 14.96 mm, and spindle speed 16,581 rpm. Under this combination, minimum Surface Roughness Ra of 0.17 μm and milling force of 24.27 N are achieved, reducing surface roughness by 85.32% and milling force by 53.52% versus the worst condition and reducing roughness by 28.57% versus the baseline while maintaining milling force within a reasonable range. This study clarifies the physical mechanism of MQL oil mist penetration, extending conventional macroscopic parameter optimization. The proposed cross-scale framework offers theoretical and engineering guidance for MQL parameter design in green precision machining of nickel-based superalloys. Full article

Magnetic biochar (MBC), a magnetically responsive soil amendment, has attracted considerable attention due to its efficient magnetic separation capability and strong potential for remediating heavy metal-contaminated soils. Despite extensive research, a comprehensive evaluation of its raw materials, synthesis routes, performance-influencing factors, removal mechanisms, and microbial interactions remains limited. This review systematically examines biomass feedstocks and magnetic precursors used in MBC production and critically evaluates preparation methods, including hydrothermal carbonization, co-precipitation, ball milling, microwave pyrolysis, and impregnation–pyrolysis. Key factors affecting heavy metal removal—such as metal speciation, pyrolysis temperature, soil properties, dosage, and feedstock type—are discussed in detail. The primary immobilization mechanisms, including redox reactions, surface and co-precipitation, ion exchange, functional group complexation, physical adsorption, π–π interactions, and electrostatic attraction, are comprehensively analyzed. Furthermore, the interactions between MBC, soil physicochemical parameters, and microbial communities are evaluated to assess ecotoxicological implications. Finally, we provide valuable recommendations for the future direction of magnetic biochar research to advance its application in heavy metal removal from soil. Full article

Artisanal gold mining (AGM) activities are increasing globally and rely on rudimentary methods, such as amalgamation, to recover gold. In this study, mercury (Hg) metallurgical balances were conducted in 18 operations and gold (Au) balances in 35 operations, at a processing site serving approximately 4000 miners in the Korokpa mining area in Minna, Niger State, Nigeria. Ore processing involves grinding ore in hammer mills to below 1 mm, concentrating gold in sluice boxes, followed by amalgamating free gold particles in the concentrate. The results showed an average Au feed grade of 1.74 g/t and an average Au recovery from gravity concentration of 42.7%. Chemical analysis of the gravity separation tailing size fractions indicates that Au is lost in coarse fractions due to poor Au liberation and in fine fractions due to inefficiency in the sluicing process. Hg lost in the tailings was calculated as the mass balance difference between Hg added and the sum of Hg recovered through filtration and volatilized Hg in bonefires. It was found that 34% of Hg was lost during amalgamation, by volatilisation (18%) and with tailings (17%). The Hg lost-to-Au produced ratio was 2.6. By optimising procedures for grinding, classification, and concentration, the efficiency of recovery can be improved. Implementing a simple Hg recovery method, such as using a retort for condensation, and improving amalgam heating time can help miners minimise environmental loss. Full article

The antioxidant efficiency of basil extract (Ocimum campechianum Mill) was evaluated in chilled (4 °C) beef hamburgers. Six treatments were prepared: control (CON), synthetic antioxidant (BHT), basil extract at 0.01% and 0.02% (BE1 and BE2, respectively), and microencapsulated basil extract at 0.01% and 0.02% (ME1 and ME2, respectively). The extracts were analyzed for their antimicrobial activity, antioxidant capacity, and phenolic compound profile. Burger physicochemical properties, lipid oxidation (peroxide value and TBARSs), colour, pH, texture, and sensory acceptance were analyzed during storage. Treatment affected both DPPH and FRAP values. A total of 28 phenolic compounds were identified. Treatments with basil extract helped control pH and reduced peroxide formation compared with the control, while colour and technological parameters were not significantly affected. TBARS values remained low across treatments. Sensory evaluation indicated lower acceptability for BE2 and ME2, although no significant differences in overall preference were observed. Consequently, basil extract, whether microencapsulated or not, can be utilized as a substitute for synthetic antioxidants in refrigerated beef hamburgers. Full article

Basidiomycetes can colonize sweet chestnut (Castanea sativa Mill) xylem, causing white or brown rot and losses in wood quality. The aim of this study was to assess the degradative potential of five Basidiomycota strains (Armillaria mellea (Vahl) P. Kumm. (Am), Fistulina hepatica (Shaeff.) With. (Fh), and Laetiporus sulphureus (Bull.) Murrill (Ls), and two strains of Ganoderma resinaceum Boud.) on three chestnut woods differing in chemistry. The woods differed in nitrogen content (0.3%–1.0%), carbon/nitrogen (C/N) ratio (43–150), and phenolic-related traits. In a 39-day laboratory assay, the five fungal strains were inoculated on three chestnut woods and compared for colonization time, extracellular enzymatic activity, and C mineralization. Fungal colonization strongly depended on fungus × wood interaction: L. sulphureus colonized all woods within 6 days, whereas the two G. resinaceum strains required 9–33 days depending on wood type; A. mellea and F. hepatica colonized only selected woods (up to 39 days). Enzymatic screening indicated laccase activity mainly in G. resinaceum (and to a lesser extent A. mellea), while L. sulphureus expressed cellulolytic activity but no laccase. Over 39 days, total C mineralization peaked under G. resinaceum on the two Sicilian woods (up to 270–300 mg CO₂–C g⁻¹ dry wood), whereas the Tuscan wood (highest C/N and phenolic content) markedly inhibited most strains; only L. sulphureus increased mineralization in this wood (85 mg CO₂–C g⁻¹ dry wood). These findings indicate that wood chemistry, especially C/N ratio and phenolic traits, strongly modulates strain-specific decay patterns. Overall, these results highlight the need for an integrated biological–biochemical approach to evaluate fungal decay potential and to inform both the selection of more durable chestnut woods for wood products and the identification of efficient strains to accelerate lignocellulosic biomass composting. Full article

Parboiling enhances the nutritional, structural, and economic value of rice, yet its adoption in the United States remains limited despite rising domestic and export demand. This review summarizes key stages of the parboiling process and their effects on milling yield, grain integrity, nutrient retention, and glycemic response. It outlines major industry challenges, including high energy and water use, uneven heating and drying, handling of defective kernels, limited automation in smaller mills, labor shortages, and emerging climate-related risks. Advances such as vacuum soaking, infrared and microwave-assisted drying, smart sensors, and AI-driven control systems show strong potential to improve efficiency and product quality. Circular-economy strategies, including biomass energy recovery, water reuse, and by-product valorization, offer additional sustainability gains. Continued research, modernization, and policy support are critical to strengthen competitiveness and positioning of the U.S. parboiled rice sector for a more resilient and sustainable future. Full article

Droplet manipulation constitutes a fundamental operation in numerous bio-microfluidic applications, including but not limited to medical diagnostics and targeted drug delivery. Among the various technologies developed for this purpose, magnetic digital microfluidics (MDMF) has emerged as a compelling approach due to its inherent advantages of contamination-free actuation, low cost, and configurational flexibility. Nevertheless, conventional MDMF remains constrained by its reliance on bulky instrumentation and substantial power consumption for generating controllable magnetic fields, which limit its in-field applications. To address these limitations, this work presents a programmable and portable electromagnetic microfluidic droplet manipulation platform that synergistically integrates static and dynamic magnetic fields to enable non-contact, high-precision droplet control under ultra-low power conditions. The proposed system comprises an electromagnetic actuation module, a permanent magnet, and a glass substrate coated with Teflon film. The entire system is secured by a PMMA support structure, within which a glass substrate is mounted and spatially separated from the permanent magnet. The PMMA support is fabricated using a milling process, offering a simple manufacturing procedure and high structural reusability and reproducibility. The control logic is implemented on a field-programmable gate array (FPGA) development board, facilitating fully autonomous operation powered by a standard battery. The platform operates at a low voltage of 3.5 V and a driving current of 180 mA, corresponding to a total power consumption of merely 0.63 W, while achieving robust manipulation of droplets in the volume range of 0.5 to 5 μL. A maximum average droplet velocity of up to 0.6 cm/s was attained under optimal conditions. The proposed platform offers a scalable and energy-efficient solution for portable droplet-based assays and holds significant promise for integration into point-of-care diagnostic tools and field-ready biochemical analysis systems. The platform demonstrates excellent operational stability and reproducibility, as validated by repeated actuation experiments with a positioning deviation of approximately 0.1 mm under optimized conditions. The fabrication process also exhibits high reliability with consistent performance across multiple experimental runs. Full article

This study aimed to determine the optimal drying, grinding, and extraction conditions for red sweet pepper, garlic, parsley, and celery to obtain concentrated extracts rich in bioactive compounds. Drying was performed using infrared ovens (FD-48 and Basic Station 3) at 30, 45, and 55 °C. The optimal temperature was 45 °C, ensuring effective moisture removal while preserving functional components. Grinding efficiency was compared between an IKA A 11 Basic analytical mill and a Pulverisette 0 vibratory micromill; the analytical mill demonstrated superior performance and processing speed. Soxhlet extraction with 96% ethanol enabled the preservation of flavor, aroma, and functional properties of the extracts. The influence of the herbal extract mixture on the organoleptic, physicochemical, and microbiological characteristics of culinary products was evaluated. For sauces, the optimal extract concentration was 5%, providing balanced taste, pleasant aroma, stable consistency, and intense color. Physicochemical analysis showed increases in protein (3.24–3.68%), ash (2.52–2.68%), dry matter (25.27–26.94%), and pH (4.11–4.24). Microbiological indicators (TAMC—3.0 × 10² CFU/g; molds—21 CFU/g; yeasts—9 CFU/g) complied with regulatory standards. For meat products (meatballs and pies), the optimal extract composition (garlic 30%, red pepper 25%, parsley 25%, celery 20%) was applied at 0.3–0.7% of meat mass. Sensory evaluation identified 0.5% as optimal. The developed technology enables the production of functional food additives rich in protein, antioxidants, and flavonoids and is suitable for industrial implementation. Full article

Cocoa pod husk (CPH), a major agro-industrial residue, contains valuable bioactive compounds whose recovery can support sustainable waste valorization. This study evaluated the influence of increasing ethanol concentrations on the ultrasound-assisted extraction (UAE) of bioactive compounds from CPH and their antioxidant, antihypertensive, and antihyperglycemic activity. Dried and milled CPH was extracted using ethanol–water mixtures (0–100% ethanol) under fixed ultrasonic conditions. Cocoa pod husk powder characterization and the resulting extracts were analyzed in terms of chemical composition (lignocellulosic compounds, proximate and elemental composition, and bromatological composition), antioxidant capacity, and in vivo antihypertensive and antihyperglycemic effects in Wistar rats. The results showed that solvent polarity strongly modulated extraction efficiency: absolute ethanol yielded the highest phenolic (171.43 mg GAE/g) and flavonoid (132.05 mg QE/g) content, whereas hydroalcoholic mixtures, particularly 50:50, enhanced overall antioxidant performance, especially in FRAP. The chemical analysis results showed the selective recovery of compounds such as quercetin, hesperidin, and theobromine, and FTIR-PCA results revealed distinct solvent-dependent chemical profiles. In vivo assays indicated modest blood pressure stabilization and a more pronounced antihyperglycemic effect after chronic administration. Overall, UAE proved an effective, rapid, and solvent-efficient method for CPH valorization, highlighting its potential for producing natural antioxidants applicable to food, nutraceutical, and cosmetic formulations. Full article

Mechanical pretreatment techniques are essential for overcoming lignocellulosic biomass recalcitrance in emerging biorefineries. This review critically synthesizes advances from 2020 to 2025 across fundamental mechanisms, hybrid technologies, energy efficiency, Life Cycle Assessment, and industrial scalability. The analysis reveals that effective pretreatment targets supramolecular modification—defect generation in cellulose crystallites and the creation of reactive sites—beyond simple particle size reduction. Impact–shear regimes prove most effective for fibrous materials. Hybrid approaches are examined: mechanocatalysis enables solvent-free depolymerization, while mechanoenzymatic technologies achieve hydrolysis without bulk water, though enzyme denaturation under mechanical stress remains unresolved. Energy consumption is the primary upscaling barrier, with Life Cycle Assessment identifying electricity use as the dominant environmental hotspot and emphasizing burden per unit of final product as the critical metric. Technology Readiness Level assessment provides a strategic framework: continuous extruders and mills are industrially mature for bulk applications, while high-intensity batch devices are suited for high-value coproducts. A research agenda prioritizing mechanistic understanding, hybrid process engineering, feedstock diversification, and embedded sustainability assessment is proposed. Full article

This study addresses the problem of improving the efficiency of fine grinding of bulk materials in a spring-rotor mill. The objective is to determine technologically sound operating parameters based on mathematical modeling, design of experiments, and multi-objective optimization. The methodology relies on a full-factorial experimental design according to the Hartley plan, with five control factors: rotor rotational speed, material loading ratio, overlap of the working zones, grinding chamber clearance, and grinding duration. The analyzed responses include grinding fineness, throughput, power consumption, specific energy consumption, and specific metal intensity. Based on experimental data, adequate second-order polynomial regression models were obtained for all response variables using the least-squares method. Statistical analysis showed that grinding time and rotational speed had the most significant influence on the process. Multi-objective optimization using the weighted-sum method enabled the identification of optimal operating conditions that balance product quality, throughput, and energy consumption. Verification experiments confirmed the adequacy of the developed models. Practical implementation of the optimized regimes increases throughput by 15–20% while simultaneously reducing energy consumption by 8–12% compared with empirically selected operating conditions. The proposed models and recommendations provide a quantitative basis for tuning and controlling grinding equipment in processing industries. Full article

This work investigates the effect of high-energy mechanical milling on the activation and phase transformation of synthetic pseudoboehmite powders. The approach aims to provide a clean, solvent-free route with potential industrial relevance for alumina production. Mechanical processing proved effective in inducing the transition from pseudoboehmite to χ-Al₂O₃ solely through milling. The process yielded nanometric particles with low levels of contamination. The subsequent conversion to α-Al₂O₃ was achieved through controlled heat treatments, while phase evolution was monitored by differential scanning calorimetry (DSC). A reduction of approximately 110 °C in the α-Al₂O₃ formation temperature was observed after 30 h of milling. This shift was accompanied by a marked decrease in the activation energy, from 526 kJ·mol⁻¹ for the raw powder to 347 kJ·mol⁻¹ for the milled sample. These results demonstrate the strong mechanochemical activation of pseudoboehmite, highlighting mechanical milling as an effective and scalable route for energy-efficient processing of alumina phases. Full article

The discharge of untreated paper mill effluent poses significant ecological risks due to its high organic and nutrient loads. This study aimed to assess the phytoremediation potential of Azolla pinnata for treating paper mill effluent. Response Surface Methodology (RSM) and Artificial Neural Network (ANN) modeling approaches were applied and optimization was used for pollutant removal and plant biomass production. Experiments were designed using a Central Composite Design with two independent variables: effluent concentration (0, 50, and 100%) and plant density (10, 20, and 30 g per container). The responses measured were biochemical oxygen demand (BOD), chemical oxygen demand (COD) removal efficiencies, and final biomass yield after 16 days of exposure. RSM produced statistically significant (p < 0.05) second-order regression models for all three responses (coefficient of determination; R² > 0.98), while ANN showed slightly lower prediction errors within the experimental range studied. Maximum observed removal efficiencies were 91.74% for BOD, 80.91% for COD, and 92.66 g biomass yield under 50% effluent concentration and 30 g plant density. Optimization via both models suggested closely comparable operating conditions (79% effluent concentration and 29 g biomass) for optimal performance. The results indicate that A. pinnata demonstrates potential as a low-cost, nature-based treatment system for industrial effluent remediation under controlled conditions. The integration of data-driven optimization with biological treatment contributes to sustainable effluent management strategies by reducing chemical inputs, minimizing energy demand, and enabling biomass generation with potential downstream valorization. Full article

This study reports the synthesis of a high-entropy AlFeCuTiNi alloy via high-energy ball milling. The study investigates the effects of mechanical alloying time and sintering temperature on the microstructure, mechanical properties, wear, and corrosion behavior of the high-entropy AlFeCuTiNi alloy. XRD, SEM, and EDX analyses revealed that the mechanical alloying time and sintering temperature significantly affected the alloy’s homogeneity, phase structure, and oxide film stability. As the mechanical alloying time increases, the corrosion resistance of alloys sintered at 550 °C initially increases and then stabilizes. In samples sintered at 650 °C, corrosion resistance is generally higher. The highest corrosion resistance was achieved after 15 h of mechanical alloying and sintering at 650 °C. The study reveals that the best corrosion, wear, hardness, and wear density performance was observed in samples obtained at medium conditions, achieved after 20 h of mechanical alloying and sintering at 650 °C. These findings may contribute to optimizing production processes for sustainable material design. Moreover, this research highlights that high-entropy alloys and powder-metallurgy-based production methods enable industrial applications for energy-efficient, sustainable material design and contribute to sustainable production and circular-economy principles. Full article

The disposal of end-of-life fluorescent lamps presents significant environmental challenges due to their mercury (Hg) content and the loss of valuable rare earth elements (REEs) contained in phosphor powders, highlighting the need for sustainable recycling strategies. This study proposes an integrated hydrometallurgical process for simultaneous mercury removal and material recovery from spent fluorescent lamps. Various leaching agents were initially evaluated for mercury dissolution, and 10% NaOCl was identified as the most effective solution. The optimized system was applied to linear T8 lamps using a combined milling–leaching approach, followed by size-based separation of metallic, glass, and phosphor fractions. Dissolved mercury was precipitated at pH 11 using Na₂S, forming crystalline α-HgS (cinnabar), as confirmed by XRD, and reducing the residual mercury concentration to 2.7 µg/L. The metallic fraction was recovered as an aluminum-based alloy containing 20.6 wt.% Cu and 10.9 wt.% Zn with low iron content, while the phosphor-rich fraction yielded approximately 50% REE extraction, followed by oxalate precipitation of yttrium-based compounds. The developed process enables efficient mercury stabilization and selective recovery of valuable materials, supporting environmentally secure and resource-efficient fluorescent lamp recycling. Full article