Search Results (844)

Wet agglomeration is essential in heap leaching of minerals, as it improves permeability by forming agglomerates through capillary and viscous forces. The Discrete Element Method (DEM) has been used to model this phenomenon, enabling the detailed tracking of interactions between individual particles. This study employs DEM to analyze the effect of particle-size distribution (PSD) on agglomerate formation inside a rotating agglomeration drum. The DEM model was validated using geometry and parameters reported in the literature, which are based on experimental studies of agglomeration in rotating drums. Both wide and bimodal PSD cases were simulated. The results demonstrate that DEM simulations of drums with exclusively fine particles are prone to producing poorly defined macrostructures. In contrast, the presence of coarse particles promotes the formation of stable agglomerates with fine particles attached to them. Additionally, decreasing the maximum particle size increases the number of agglomerates and improves the homogeneity of the final PSD. These findings improve our understanding of wet agglomeration dynamics and provide practical criteria for optimizing feed design in mineral-processing applications. Full article

Unripe Pisang Awak banana is rich in resistant starch and dietary fiber, which are recognized for supporting digestive health and bowel regularity, yet its limited solubility restricts its application in instant beverages. This study aimed to improve the functional quality of Pisang Awak banana powder (PABP) through drum drying, electron beam irradiation, and inulin supplementation. PABP was produced by tray or drum drying and irradiated at 0, 2, 4, 6, and 8 kGy. Drum-dried powder treated with 8 kGy was identified as optimal and further fortified with inulin at 0–10% (w/w). Compared with tray drying, drum drying with irradiation markedly accelerated rehydration and enhanced solubility. Incorporation of 10% inulin produced the best overall performance, yielding faster reconstitution, greater solubility at 80–90 °C, and lower viscosity values across all pasting parameters. Collectively, the combination of drum drying, irradiation, and inulin addition yielded a banana powder with improved reconstitution and reduced gelation upon cooling. This optimized formulation demonstrates potential as a model for starch-based instant powders, while also contributing to the sustainable utilization of local banana resources. Full article

Background: It is crucial to evaluate liver fibrosis in metabolic dysfunction-associated steatotic liver disease (MASLD). Digital pathology, an automated method for quantitative fibrosis measurement, provides valuable support to pathologists by providing refined continuous metrics and addressing inter-observer variability. Although non-invasive tests (NITs) have been validated as consistent with manual pathology, the relationship between digital pathology and NITs remains unexplored. Methods: This study included 99 biopsy-proven MASLD patients. Quantitative-fibrosis (Q-Fibrosis) used second-harmonic generation/two-photon excitation fluorescence microscopy (SHG/TPEF) to quantify fibrosis parameters (q-FPs). Correlations between eight NITs and q-FPs were analyzed. Results: Using manual pathology as standard, Q-Fibrosis exhibited excellent diagnostic performance in fibrosis stages assessment with area under the receiver operating characteristic curves (AUCs) ranging from 0.924 to 0.967. In addition, magnetic resonance elastography (MRE) achieved the highest diagnostic accuracy (AUC: 0.781–0.977) among the eight NITs. Furthermore, MRE-assessed liver stiffness measurement (MRE-LSM) showed the strongest correlation with q-FPs, particularly adjusted by string length, string width, and the number of short and thick strings within the portal region. Conclusions: Both MRE and digital pathology demonstrated excellent diagnostic accuracy. MRE-LSM was primarily determined by collagen extent, location and pattern, which provide a new perspective for understanding the relationship between the change in MRE and histological fibrosis reverse. Full article

As crucial transportation hubs and economic nodes, the underwater security and infrastructure maintenance of harbors are of paramount importance. Harbors are characterized by high vessel traffic and complex underwater environments, where traditional underwater inspection methods, such as diver operations, face challenges of low efficiency, high risk, and limited operational range. This paper introduces a collaborative survey and disposal system that integrates a deformable unmanned surface vehicle (USV) with a lightweight remotely operated vehicle (ROV). The USV is equipped with a side-scan sonar (SSS) and a multibeam echo sounder (MBES), enabling rapid, large-area searches and seabed topographic mapping. The ROV, equipped with an optical camera system, forward-looking sonar (FLS), and a manipulator, is tasked with conducting close-range, detailed observations to confirm and dispose of abnormal objects identified by the USV. Field trials were conducted at an island harbor in the South China Sea, where simulated underwater objects, including an iron drum, a plastic drum, and a rubber tire, were deployed. The results demonstrate that the USV-ROV collaborative system effectively meets the demands for underwater environmental measurement, object localization, identification, and disposal in complex harbor environments. The USV acquired high-resolution (0.5 m × 0.5 m) three-dimensional topographic data of the harbor, effectively revealing its topographical features. The SSS accurately localized and preliminarily identified all deployed simulated objects, revealing their acoustic characteristics. Repeated surveys revealed a maximum positioning deviation of 2.2 m. The lightweight ROV confirmed the status and location of the simulated objects using an optical camera and an underwater positioning system, with a maximum deviation of 3.2 m when compared to the SSS locations. The study highlights the limitations of using either vehicle alone. The USV survey could not precisely confirm the attributes of the objects, whereas a full-area search of 0.36 km² by the ROV alone would take approximately 20 h. In contrast, the USV-ROV collaborative model reduced the total time to detect all objects to 9 h, improving efficiency by 55%. This research offers an efficient, reliable, and economical practical solution for applications such as underwater security, topographic mapping, infrastructure inspection, and channel dredging in harbor environments. Full article

Efficient production of high-quality cubical crushed stone is critical for road construction and concrete manufacturing. Conventional vibrating screens suffer from low cubicality and high energy consumption, limiting their applicability. We developed a novel spiral vibrating screen featuring a helical screening surface and adjustable oscillation parameters. Experimental studies were conducted on granite aggregates (5–20 mm) at vibration frequencies of 16–26 Hz and amplitudes of 1.5–4.0 mm to evaluate cubicality, screening efficiency, throughput, and energy consumption. Under optimal operating conditions (22 Hz, 3.0 mm amplitude), the prototype achieved 84–86% cubical particles, 93–95% screening efficiency, and specific energy consumption of 1.20 ± 0.05 kWh/t. Compared with conventional flat and drum screens, cubicality improved by 8–12 percentage points, while energy consumption decreased by up to 12%. The developed screen offers a scalable solution for producing high-quality cubical aggregates with lower energy demand and reduced clogging risks. These findings provide practical guidance for improving aggregate processing technologies. Full article

Shearer drum cutting of coal seams generates over half of the coal dust in coal mines, while relevant studies focus more on micron-sized dust and much less on nano- to sub-micron-sized coal dust. Based on the self-developed experimental system for simulating dust generation from drum cutting of coal bodies, this study investigated the concentration distribution characteristics and physicochemical properties of 10 nm–10 μm coal dust generated from drum cutting of different rank coals with different cutting parameters. Results showed that the coal dust mass and number concentrations were concentrated in 2–10 μm and 10–200 nm, respectively, accounting for 90% of the total 10 nm–10 μm coal dust; the mass percentages of PM1/PM10 (PM1/PM10 = PM1 particles relative to PM10 particles, similarly hereinafter), PM1/PM2.5, and PM2.5/PM10 were 3.25–4.87%, 19.35–26.73%, and 14.82–18.81%, respectively, whereas over 99% of the total number of particles in the PM10 fraction are within the PM1 fraction (i.e., N-PM1/N-PM10 > 99%), that is, both N-PM1/N-PM2.5 and N-PM2.5/N-PM10 exceeded 99%. Lower-rank coal generates less 10 nm–10 μm coal dust, and either higher moisture content, firmness coefficient, or lower fixed carbon content of the coal can effectively reduce the 10 nm–10 μm coal dust generation. Either reduction in the tooth tip cone angle, the rotary speed, or increase in the mounting angle or the cutting depth can effectively inhibit the 10 nm–10 μm coal dust generation. Higher-rank coal dust shows fewer surface pores, smoother surfaces, larger contact angles, more hydrophobic groups, and fewer hydrophilic groups. The research results have filled the knowledge gap in the pollution characteristics of nano- to submicron-sized dust generated from shearer drum cutting of coal bodies, and can serve as an important reference for the development of dust reduction and suppression technologies in coal mining faces as well as the prevention of coal worker’s pneumoconiosis. Full article

Production flow control is a key area affecting the productivity of production systems. The use of an appropriate control method ensures that customer requirements are met while maintaining an acceptable level of production costs. In many cases, the choice of control method does not allow for significant improvements in production processes, as the known guidelines are not very detailed. This article presents research on the impact of factors related to products, production processes, and customer orders on, for example, the number of technological operations, the number of production stations, product demand (product, process, and order conditions—PPOC), and the effectiveness of production flow control methods. This research was conducted for selected product families (water and gas fittings) for which various production flow control solutions were developed. The most popular control methods were used: push–schedule, supermarket-type pull, sequential pull, mixed pull, and drum-buffer-rope. The criteria for evaluation were in-process stocks and lead time of materials in the production process. As a result of the ranking, relationships were identified by indicating how the values of PPOC factors affect the effectiveness of a given production flow control method. The results of this research can serve as guidelines for companies in selecting the most appropriate method of controlling production processes. Full article

The mixing process of powder materials determines the final quality of industrial products. This study employs the Discrete Element Method (DEM) to numerically characterize the effects of particle shape and mixer structure on mixing performance. Using the superquadratic equation, nine types of particles with regular shape variations are constructed, and mixing models are further simulated. The feasibility of superquadratic-generated particles is validated through a classic drum calibration experiment. To investigate the intrinsic mechanisms of particle shape effects, the motion and contact behaviors of particles are quantified by the diffusion index, proportion of rotational kinetic energy, interparticle compressive force, and contact number. Meanwhile, to examine geometry effects, three supplementary mixing simulations are conducted by varying the plow angle and deactivating the choppers. The results show that Cubic particles exhibited poor mixing performance, while disk-shaped particles outperformed cylindrical ones; Increasing the plow blade inclination angle enhanced particle convection and diffusion, whereas excessively small angles may fail to achieve homogeneous mixing; The auxiliary shear of chopper blades promoted particle diffusion, effectively overcoming dead zones between plow blade intervals. Full article

To meet the usage requirements of the wellhead mandrel-type tube hanger of 175 MPa ultra-high pressure, four specially shaped metal sealing structures are selected as the research objects in this paper. The mechanical properties of different metal sealing structures are calculated, respectively, by using finite element software and binary regression analysis software. It was found that the mechanical properties and contact pressure fluctuations of X-shaped and straight U-shaped metal seals were relatively large, and the sealing width was relatively small among the four types of special-shaped metal seals. The mechanical properties and sealing performance of ball-drum-type metal seals and elliptical U-shaped seals were relatively stable, and the contact width was relatively large. For the single U-shaped sealing structure, the optimization rates of the maximum contact pressure and the minimum equivalent stress reached 11.63% and 10.63%, respectively. For the double U-shaped structure, the optimization rates of its maximum contact pressure and minimum equivalent stress both exceed 12%. The tests showed that the metal sealing structure met the pneumatic sealing requirement of 175 MPa. These results provide theoretical guidance for the research and design of a new type of ultra-high-pressure mandrel oil and casing hanger with a long service life and high reliability. Full article

Green soybean (Glycine max L.), commonly known as edamame, is recognized for its rich phytochemical content and nutritional and functional benefits. However, its limited shelf life and susceptibility to quality degradation restrict its commercial potential in fresh form. To address this, green soybean seeds can be processed into extract and powder forms, which offer greater stability and added value. The preparation of crude procyanidin extract was examined in this study along with the effects of three distinct extraction techniques: enzyme incubation, ultrasonic-assisted extraction (UAE), and enzymatic hydrolysis followed by ultrasonic-assisted extraction (EUAE). Additionally, the effects of two drying methods (drum-drying and spray-drying) on the retention of bioactive compounds and antioxidant activity were assessed. Optimal conditions for each drying method were selected to enhance antioxidant properties by fortifying instant green soybean powder (GSP) with encapsulated crude procyanidin extract (ECPE). The chemical, physical, and sensory properties of ECPE-fortified GSP were analyzed. Results indicated that the EUAE method was the most effective for procyanidin extraction. Encapsulation allowed for procyanidin retention of over 83% after storage at 25 and 35 °C for 12 weeks. The optimal conditions were determined to be drum-drying at 3 rpm and spray-drying at an inlet temperature of 200 °C for the drying techniques. Fortification of GSP with 3–5% ECPE powder positively correlated with increased phytochemical content and antioxidant activity. Both drum- and spray-dried GSP maintained color integrity comparable to the control. Drum-dried GSP preserved greater concentrations of bioactive compounds and exhibited superior antioxidant activity compared to spray-dried GSP. All powdered products had acceptable water activity (≤0.60) and moisture content (≤12%), suggesting suitability for long-term storage. Although spray-dried powders exhibited greater hygroscopicity, they demonstrated lower emulsion stability and solubility compared to drum-dried powders. Drum-dried GSP retained higher levels of carbohydrate, fat, fiber, and ash compared with spray-dried powder, while protein content was similarly preserved by both methods. In conclusion, ECPE powder serves as a promising functional ingredient in instant green soybean powder. Both drum-dried and spray-dried GSP products exhibit potential for application in a variety of functional food products. Full article

A fully automated, buoy-based deployment sensor system is being developed to acquire high-quality water column data, and requires a controller to accurately position an array of sensors at various depths. The sensor system will be potentially deployed under rough ocean conditions. Depth is measured by a pressure sensor and adjusted through a rotating drum powered by a stepper motor. The proposed controller uses a model predictive control algorithm, a type of optimal control that predicts system response to optimize control actions used to track a desired variable-depth, setpoint profile. The profile is calculated to ensure smooth motion of the system, preventing motor malfunction. A simplified system model was created and used to simulate an open-loop test and system response. Constraints were applied to the control actions to match the practical limitations of the stepper motor. The simulated results show successful tracking of both a shallow and deep profile. At this stage of testing, the effects of ocean currents are considered by using a simple disturbance that provides the effect of ocean currents. A practical prototype that can implement the model predictive controller was tested on the physical buoy-based system with good control performance. Full article

To improve the uniformity and precision of soybean seeding, this study designed a high-speed airflow-assisted seeding system for the pneumatic drum-type high-speed precision seed-metering device. The system accelerates seed delivery through airflow and ensures precise seed placement using a seed press wheel. Computational Fluid Dynamics (CFD) and Discrete Element Method (DEM) coupling simulations were employed to analyze the seed motion trajectory, collision process, and velocity changes. Key design parameters of the airflow-assisted delivery system were optimized, including a tube diameter of 16 mm, a curved section radius of 80 mm, a seed delivery angle of 33.65°, and a press wheel diameter of 254 mm. The simulation results indicated that the relative position between the seed delivery tube and the seed drum significantly impacts seed trajectory and uniformity. Lowering the tube to align with the seed velocity direction minimized collisions and enhanced seed spacing consistency during high-speed operation. Increasing inlet air pressure improved seed distribution uniformity by accelerating seeds within the tube, reducing travel time and collisions; a 500 Pa pressure increase raised the maximum flow velocity by approximately 5 m/s. However, seed acceleration exhibited diminishing returns: pressure increase from 2.5 kPa to 3.5 kPa increased seed speed by 2.1 m/s, while a further increase to 4.5 kPa only added 1.1 m/s. The optimal inlet pressure for efficient energy transfer and seed acceleration was approximately 3.5 kPa. The press wheel played a crucial role by dispersing the impact force when seeds contact the soil, which achieved high capture rates above 94.0% across the seed drum rotary speed range of 11 to 19 rpm. This research provides theoretical and experimental support for the optimization of high-speed airflow-assisted seeding systems, offering significant practical value for large-scale agricultural production by enhancing seeding efficiency and quality. Full article

Primary or recurrent infection of cytomegalovirus (CMV) in pregnant women may cause transplacental transmission to fetuses. We aimed to investigate the rate of transplacental CMV transmission in women with positive anti-CMV IgG and negative anti-CMV IgM and its impact on newborns. Pregnant women with positive anti-CMV IgG and negative anti-CMV IgM during the first or second trimester who delivered by Cesarean section were included. Amniotic fluid collected during the Cesarean section was tested for CMV DNA with quantitative real-time polymerase chain reaction. CMV IgG and IgM were measured with enzyme-linked immunosorbent assay. A total of 695 pregnant women were enrolled between April 2019 and February 2023. Of them, 567 (81.6%) were single pregnancies and 128 (18.4%) were twin pregnancies, and 594 (85.5%) were full-term pregnancies and 101 (14.5%) were premature pregnancies. Of the 823 newborns, 7 (0.9%) were CMV DNA positive in amniotic fluid, demonstrating the transplacental CMV transmission. One of these seven neonates was diagnosed with intrauterine growth restriction at gestation week 25⁺¹ and at birth at a gestational age of 30⁺² weeks. However, all seven children had normal hearing, vision, and neurodevelopment at the age of 18–56 months. Transplacental CMV transmission may occur in offspring of pregnant women with positive anti-CMV IgG and negative anti-CMV IgM, but the long-term sequelae appear to be minimal. Full article

This study demonstrates that rearing duration (14 and 30 days) and environmental salinity (0, 4, 8, and 12 parts per thousand (ppt) of NaCl) synergistically modulate osmoregulation and muscle texture in adult freshwater drums (Aplodinotus grunniens). Salinity significantly reduced the hepatosomatic index at 30 days (p < 0.05). Furthermore, serum biochemical indices were markedly affected. Higher salinity and prolonged rearing time decreased triglycerides, total cholesterol, and low-density lipoprotein (LDL), while high-density lipoprotein (HDL) levels increased at 14 days (p < 0.05), indicating improved lipid metabolism efficiency. Crucially, osmotic pressure remained stable across salinities at 14 days but exhibited a dose-dependent increase at 30 days (p < 0.05), driven primarily by elevated Na⁺ and Cl⁻ concentrations. Salinity (8–12 ppt) markedly enhanced water-holding capacity, reducing cooking loss (~58%), centrifugal loss (~74%), drip loss (~83%), and thaw loss (~84%) versus 0 ppt controls (p < 0.05). Concurrently, key texture parameters also significantly improved, as reflected by hardness, chewiness, resilience, and gumminess. These enhancements might be attributed to hyperosmotic stress-induced cellular dehydration and ionic strength-mediated protein cross-linking. Full article

This study investigates the chemical and sensory effects of UV-C disinfection on black, white, green, and pink peppercorns using a scalable mechanical drum reactor. While previous research has demonstrated the efficacy of UV-C radiation in microbial disinfection, there is a lack of deep, quality-focused research on food products. Nevertheless, for spices, this is just as important, if not more so, than food safety. Different analyses were conducted to assess changes in volatile compounds, organic acids, fatty acids, tocopherols, and colour following UV-C exposure. Additionally, sensory evaluations were performed using triangular tests to determine whether these chemical changes were perceptible to consumers. Results revealed that many of the measured chemical components were affected by the UV treatment, with some volatile compounds decreasing by up to 90%, while certain organic acids increased by more than 150%. Despite these changes, no significant differences in colour, aroma, or flavour were detected by the sensory panel across all pepper types. These findings suggest that UV-C irradiation, when applied under the tested conditions, preserves the sensory quality of peppercorns, supporting its potential as a non-thermal processing method for spice treatment. Full article