Search Results (4,002)

Data centers are large and rapidly growing electricity consumers, and cooling systems account for a substantial share of their energy demand. A key contribution of this study is a climate-sensitive, hourly techno-economic comparison of three data-center cooling configurations under consistent operating assumptions: a conventional water-cooled centrifugal chiller baseline, a magnetic bearing chiller (MBC) system, and an MBC system integrated with aquifer thermal energy storage (ATES). The comparison is performed for Phoenix, Arizona, and Fairbanks, Alaska, which represent substantially different cooling climates in the U.S. Hourly simulations use identical information technology (IT) load profiles, identical aggregate installed chiller capacity represented by two 4058 kW chiller units, common water-side economizer controls, and site-specific weather and electricity tariffs. Results show that the MBC system reduces annual cooling-system electricity consumption from 1169.4 to 957.4 MWh in Phoenix (18.1%) and from 361.6 to 319.4 MWh in Fairbanks (11.7%). Peak cooling-system electrical demand decreases by 119.4 kW in Phoenix and 71.6 kW in Fairbanks. Relative to the centrifugal baseline, the MBC case gives a 5.8-year simple payback in Phoenix but is not economically attractive in Fairbanks under the assumed tariff. The MBC-only case gives the lowest annual cooling electricity use in both climates. The MBC+ATES case is treated only as a screening-level, discharge-assisted cold-storage scenario rather than a full techno-economic assessment of seasonal ATES, and no site-specific hydrogeological feasibility assessment is performed. Under the assumed O&M cost structure, MBC+ATES gives a higher discounted value of savings than MBC-only, but this economic result is not caused by additional cooling-electricity savings relative to MBC-only. The MBC+ATES case also has a longer payback period because of its higher capital cost. These results show that the value of advanced cooling configurations depends on climate, free-cooling availability, electricity pricing, storage assumptions, and economic assumptions within the modeling framework considered in this study. Full article

Phycobiliproteins are water-soluble photosynthetic pigments extracted mainly from microalgae and cyanobacteria with many potential biotechnological applications, such as healthy food colorants, nutraceuticals, fluorescent tags, or non-toxic therapeutic agents. We have recently devised a green innovative two-step ultrasound-based process (named UltraBlu) to obtain blue phycocyanin (a phycobiliprotein) with a high-purity grade from the cyanobacterium Limnospira platensis. To assess the possibility of a wider use of the method, this study evaluates the UltraBlu process on an organism of a different taxonomic domain, the red microalga Porphyridium cruentum, for extracts rich in B-phycoerythrin (B-PE), the main phycobiliprotein produced by this organism. The UltraBlu process is characterized by the extraction of phycobiliproteins decoupled from biomass cell lysis, although the process is entirely carried out in an aqueous medium. Conversely, cell lysis is integrated with the purification step and is carried out by ultrasonication in ammonium sulfate solution before the pigment extraction/recovery step. B-PE, significantly purer than that obtained via conventional one-step direct ultrasound-assisted extraction, was recovered within a few hours from fresh biomass, only isolating the B-PE extract from the leftover biomass by centrifugation. Yields generally exceeded 9%, approaching the highest pigment contents reported for P. cruentum in the literature. Full article

Raw Chinese lacquer, tapped from the sap of Toxicodendron vernicifluum, is a natural water-in-oil microemulsion containing urushiol, polysaccharides, proteins, and laccase. Because this reactive system continues to oxidize and polymerize after harvesting, handling conditions directly determine water content, viscosity, and later film-forming performance. This review analyzes potential in situ stabilization routes that couple purification, low-temperature vacuum dehydration, and quality conditioning at, or near, the collection site. Emphasis is placed on how laccase retention, oxygen exposure, and urushiol polymerization are controlled together to limit transport losses and premature crusting. Portable filtration devices, reported centrifugal filtration systems, and proposed vacuum dehydration strategies are compared in terms of throughput, field compatibility, and process control. Physical and bio-based conditioning strategies, including shear adjustment, oxygen management, and natural film-forming aids, are further considered for on-site regulation. Surface-enhanced Raman spectroscopy (SERS) and portable spectroscopic devices are examined as feedback tools for parameter adjustment under field temperatures, humidity, and storage variation; however, these signals are treated as decision-support indicators that still require lacquer-specific calibration after tapping. The central task is to define a field-compatible process window for water removal, laccase retention, viscosity control, drying behavior, and storage stability before downstream coating preparation. The remaining challenges involve miniaturized equipment, standardized evaluation, evidence-level classification, and dynamic control of coupled variables. Full article

Time delays are inherently present in active control systems as a consequence of sensor acquisition, communication lags, and actuator dynamics, and their impact on system behavior cannot be overlooked. This paper examines the effect of delayed displacement and speed feedback gains on the nonlinear lateral and vertical vibrational behavior of a MAGLEV vehicle subjected to aerodynamic and centrifugal forces. A delayed nonlinear dynamic model incorporating a fractional-order PD controller under aerodynamic excitation is first established for the MAGLEV system. Subsequently, the method of multiple scales is employed to derive the frequency response relationships, while the corresponding steady-state solutions are analyzed to determine system stability. The investigation further explores how the delays alter the nonlinear dynamic response. It also considers the impact of changing the value of the fractional-order parameter $\alpha$ on the vehicle’s dynamics. The results showed that increasing controller delays reduces the stability region, with displacement-feedback delays having a more pronounced effect than speed-feedback delays, while fractional-order derivatives ($0<\alpha <1$) further degrade stability; consequently, the integer-order case ($\alpha =1$) is recommended to achieve lower vibration levels and improved dynamic stability. The outcomes of this work provide valuable understanding of vibration phenomena encountered in MAGLEV systems and contribute to the development of improved control and optimization strategies for safer, smoother, and more reliable vehicle performance. Full article

In vitro capacitation of boar spermatozoa remains highly variable among laboratories due to differences in media composition, incubation conditions, and previous semen handling. Since capacitation is a dynamic process, identifying how different media modulate specific sperm responses over time is crucial to improving the standardization of porcine in vitro fertilization protocols. This study evaluated the temporal dynamics of membrane lipid disorder, acrosomal integrity, mitochondrial activity, and motility patterns in response to different media. Commercial boar semen doses were centrifuged and resuspended in a non-capacitating control solution or in three capacitation media differing mainly in bicarbonate, caffeine, and energy substrate composition, and evaluated every 15 min using flow cytometry and computer-assisted semen analysis at 38 °C for up to 2 h. Media containing higher bicarbonate and caffeine concentrations induced rapid membrane lipid destabilization and increased acrosomal exocytosis during the initial incubation period. Subsequently, these changes were accompanied by a more rapid decline in cell viability over time. In contrast, the medium containing lower bicarbonate together with lactate and pyruvate preserved higher viability, mitochondrial activity, and a more sustained, linear movement pattern (higher linearity and straightness). Interestingly, training-associated responses were detected immediately at time 0, suggesting that semen storage conditions may prime spermatozoa before incubation. Overall, medium composition and pre-treatment handling conditions should both be considered when standardizing porcine reproductive technologies. Full article

High-temperature smoke remains a primary threat in tunnel fire safety. The curved walls of small-radius Urban Traffic Link Tunnels (UTLTs) significantly alter smoke flow patterns and temperature distribution. Furthermore, no quantitative model exists to assess the impact of transverse fire location variation on temperature distribution in small-radius UTLTs. To address this gap, this study integrates experimental and numerical methods to specifically investigate the influence of curvature radius and transverse fire location on ceiling temperature distribution. Key findings demonstrate: (1) Wall-adjacent fires exhibit substantially higher temperatures than non-adjacent scenarios, resulting from restricted air entrainment (increasing flame height) combined with wall thermal constraint effects. (2) Competition between centrifugal and inertial forces consistently produces a higher maximum temperature rise beneath the convex ceiling versus the concave side in curved sections. (3) A novel dimensionless parameter $R_{cs}$ is derived from smoke control volume force analysis. This parameter quantifies the coupled effect of curvature radius and ventilation velocity on convex-concave ceiling temperature difference, enabling a predictive regression equation. (4) Through dimensional analysis, key governing dimensionless parameters are identified. Incorporating the Richardson number ($Ri$), which characterizes inertial-to-buoyant force competition, a predictive model for maximum ceiling temperature rise in small-radius UTLTs is ultimately established. Full article

Mixing a proppant-laden base fluid with high-pressure CO₂ can reduce its effective sand volume fraction, thereby impairing proppant placement and fracture conductivity. This study performs a numerical structural screening of the helical guide groove in a centrifugal–filtration sand concentrator intended for the pre-foaming base-fluid line upstream of the foam generator and operating against a 105 MPa outlet backpressure. The full-scale base geometry—an inner diameter of 500 mm, a concentration-zone length of 3500 mm, and 18 slotted-screen openings—was retained, while groove depth (10–40 mm), groove width (110–150 mm), and pitch (300–700 mm) were varied sequentially in 14 factor-level evaluations (12 unique geometries). Steady-state calculations were conducted in ANSYS Fluent 2022 R1 using an Eulerian–Eulerian two-fluid framework, the RNG k–ε turbulence closure, a constant apparent liquid viscosity of 0.040 Pa·s, and a compiled UDF-based phase-selective screen condition. CO₂ was not included as a separate phase. Within the investigated ranges, increasing groove depth and width increased the sand volume fraction at the concentrated-fluid outlet, whereas pitch produced a pronounced inverted-U-shaped response. The best tested geometry had a pitch of 500 mm, a width of 150 mm, and a depth of 40 mm, yielding an outlet sand volume fraction of 54.05%. This value is 3.80 percentage points higher than the lowest-performing tested configuration (50.25%), corresponding to a relative increase of 7.56%; it is also 14.05 percentage points above the inlet value of 40.00% and 4.05 percentage points above the engineering target of 50.00%. The results provide comparative numerical evidence for groove-parameter selection; independent experimental validation remains required before field application. Full article

To address the technical bottleneck of balancing the wideband noise (100–800 Hz) and aerodynamic performance of multi-blade centrifugal fans in air conditioning indoor units, this paper proposes a “frequency-domain target-driven” parametric design method for micro-perforated silencers. This method began with the precise identification of the 1/3-octave band noise spectrum to determine two noise peak clusters—200–400 Hz and 700–800 Hz—as the target suppression frequency bands. Based on Ma Dayou’s micro-perforated plate theory, a reverse mapping chain of “target frequency range → resonance frequency → structural parameters (hole diameter, perforation rate, rear cavity depth)” was established to enable the quantitative calculation of the silencer’s geometric parameters. Addressing engineering constraints related to manufacturing precision, clogging prevention, and structural stiffness for the theoretically optimal aperture size (0.24 mm), the aperture was adjusted to 1.0 mm through iterative recalculation of the relationship between plate thickness and perforation rate, while maintaining the perforated plate constant k ≈ 1.40 to ensure that the theoretical sound absorption frequency band remained unchanged. Test results show that under semi-anechoic chamber conditions (background noise ≤ 10 dB(A)), the micro-perforated silencer maintains airflow and power without attenuation across all airflow rates; noise peaks in the 200–400 Hz and 700–800 Hz frequency bands are significantly suppressed, and the full-band spectrum tends toward flatness. The average total noise level was reduced by 1 dB(A), and the average peak sound pressure level was reduced by 4 dB(A); the reduction in peak levels was four times that of the total reduction, revealing that the noise reduction mechanism of this method is “frequency-selective resonant absorption” rather than “uniform attenuation across the entire frequency band.” This study provides a quantifiable and reproducible design process for micro-perforated silencers, offering methodological support and engineering references for the development of low-noise compact fan systems in household appliances. Full article

This preliminary within-animal study focuses on the comprehensive characterization of pork jowl (PJ) by comparing it with pork belly (PB), Boston butt (BB), and spare ribs (SR) collected from the same ten castrated Duroc × Landrace × Yorkshire (DLY) pigs; headspace volatile analysis used a matched subset of six pigs. Instrumental quality, proximate composition, amino-acid and fatty-acid profiles, low-field nuclear magnetic resonance (LF-NMR) water distribution and headspace solid-phase microextraction–gas chromatography–mass spectrometry (HS-SPME-GC-MS) volatile profiles were evaluated. PB exhibited the lowest shear force, hardness, and chewiness. Across the four pork cuts, crude protein content ranged from 16.87% to 18.10%, whereas crude fat content ranged from 13.03% to 22.20%. BB had the lowest crude fat content (13.03%) and relatively high protein (18.10%) and amino-acid contents. PJ showed highest content of monounsaturated fatty acids (MUFAs) and the lowest numerical atherogenic (AI) and thrombogenic indices (TI), but also the highest n-6/n-3 polyunsaturated fatty acids (PUFA) ratio. LF-NMR showed that PJ had the highest T₂₃ and P23 values, consistent with its higher cooking and centrifugal losses. Sixty-five headspace volatile compounds were tentatively identified under the standardized 80 °C HS-SPME conditions. OPLS-DA differentiated the four cuts, and ten compounds meeting the combined criteria of VIP > 1, q < 0.05, and OAV > 1 were retained as candidate discriminant aroma-relevant compounds. Overall, the four cuts exhibited distinct quality profiles: PJ combined a MUFA-rich lipid fraction with greater free-water mobility and water loss, PB showed the greatest instrumental tenderness, BB had the lowest crude fat content and relatively high protein and amino-acid contents, and SR exhibited the greatest headspace volatile abundance. The data provide a reference for cut-specific utilization of pork raw materials. Full article

Extracellular polymeric substances (EPS) are recoverable high-value biopolymers from excess sludge (ES), but their antioxidant performance and enhancement strategies remain poorly understood. This study systematically investigated sludge-derived EPS (EPS_S) and Pseudomonas sp.-derived EPS (EPS_P) to elucidate the effects of source, extraction conditions, and sulfation on antioxidant activity. Compositional analysis, physicochemical characterization, Fourier-transform infrared spectroscopy, and excitation-emission matrix fluorescence spectroscopy were used for mechanistic analysis. EPS_S exhibited stronger 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity than EPS_P, associated with its higher polysaccharide content, lower protein-to-polysaccharide ratio, and more stable polysaccharide–protein heterogeneous network. Extraction conditions significantly influenced EPS yield, particle size, apparent viscosity, and composition; optimal recovery efficiency and antioxidant activity were achieved by centrifugation at 10,000 rpm for 10 min followed by dialysis through a 3500 Da molecular weight cutoff membrane. Sulfation successfully introduced sulfate ester groups while preserving the main structural framework, further enhancing the radical scavenging activities of both EPS types. Notably, EPS_S demonstrated greater structural stability during sulfation and retained higher Pb(II) removal capacity compared with EPS_P at the tested concentration. Overall, this study provides a mechanistic understanding of factors governing EPS antioxidant performance and validates sulfation as an effective enhancement strategy, supporting the high-value utilization of ES from wastewater treatment plants. Full article

Real-time monitoring of wind turbine aeroelastic damping is crucial for dynamically adjusting operational strategies and enhancing turbine stability and economic efficiency. However, since aeroelastic damping cannot be directly measured and effective industrial methodologies remain limited, this study proposes an innovative hybrid prediction framework for aeroelastic damping of wind turbine blades based on field-measured turbine data. First, a general model for calculating blade root reaction forces was developed using blade element momentum theory, considering multiple influencing factors such as motor torque, gravitational force, and centrifugal force. Linear regression and decision tree algorithms were employed to identify key coefficients in the theoretical model, thereby providing accurate hub load inputs for finite element (FE) calculations of tower aeroelastic damping through blade physical modeling. Second, a full-scale FE model of the wind turbine was constructed in Abaqus, where dynamic responses were computed using hub axial forces as inputs and compared with field data to obtain aeroelastic damping values, yielding high-quality labeled data for training machine learning models. Finally, an aeroelastic damping dataset was generated through data analysis and downsampling, and a long short-term memory recurrent neural network was trained as the prediction model. Simulation results demonstrated high accuracy, with mean prediction errors below 2.2% and maximum errors below 2.5% on real turbine datasets. In addition, experimental validation further confirmed the effectiveness of the proposed method. The model features a computationally efficient architecture, strong real-time applicability for high-dimensional inputs, and considerable potential for practical implementation. Full article

Centrifugal atomization is used to generate droplets or particles in processes ranging from crop protection and metallurgical powder production to rotary-bell coating, combustion, and spray-based product processing. However, comparison across studies is hindered by differences in atomizer geometry, characteristic scales, fluid properties, operating windows, diagnostic methods, and performance metrics. This article presents a structured critical review of centrifugal atomization mechanisms, investigation methods, and multidisciplinary applications. The literature is organized according to operational definitions, atomizer configuration, liquid-film evolution, primary and secondary breakup, experimental and numerical approaches, and application-level performance. Rather than assuming universal phase boundaries, the review synthesizes reported transition criteria for direct-drop, ligament, and film breakup and examines their dependence on geometry, liquid throughput, rotational speed, fluid rheology, surface tension, and surrounding-gas conditions. Across applications, the available evidence indicates that rotational speed and liquid throughput strongly affect film thickness and breakup intensity, but their influence on droplet or particle size remains conditional on the prevailing regime and device geometry. The review further compares the strengths, limitations, validation status, and transferability of commonly used experimental and computational methods. Remaining priorities include standardized definitions of characteristic scales, matched-condition comparisons, uncertainty reporting, benchmark datasets for multiphysics models, and testable criteria for scale-up and cross-application transfer. Full article

This study evaluated plasma gel preparation protocols with potential to yield more biocompatible materials for facial aesthetic applications. Human dermal fibroblasts were cultured in medium supplemented with 20% plasma gel obtained using four protocols: G1, centrifugation at 580 g for 8 min in tubes with anticoagulant followed by activation with 10% calcium chloride; G2, centrifugation at 580 g for 8 min in tubes with anticoagulant without activation; G3, centrifugation at 210 g for 8 min in tubes without anticoagulant with activation; and G4, centrifugation at 210 g for 8 min in tubes without anticoagulant and without activation. All protocols involved heating plasma at 76 °C for 12 min to produce gels. Cell viability was assessed using MTT and Crystal Violet assays over 72 h. Cell morphology and fibrin formation were analyzed by hematoxylin/eosin staining. Cell migration was evaluated using a wound healing assay. RT-qPCR analysis of COL1A1 and FN1 was performed after 24, 48, and 72 h. Fibroblasts cultured with plasma gel from G3 and G4 showed significantly higher viability compared with the control group. G1 and G2 exhibited increased fibrin formation and reduced cell density. Slower wound closure was observed in G2, which was consistent with increased late-stage expression of COL1A1 and FN1. In the conditions evaluated, low-speed centrifugation and the use of tubes without anticoagulant improved plasma gel biocompatibility. Lack of activation after high-speed centrifugation was associated with slower wound closure. Full article

Pump-as-Turbine (PaT) systems represent a cost-effective solution for hydraulic energy recovery in existing water networks and industrial processes. However, the prediction of their performance in turbine mode remains challenging, especially under off-design conditions where unsteady flow structures and internal losses strongly affect the machine efficiency. In this work, transient CFD simulations of a real industrial centrifugal pump operating as a turbine are performed using OpenFOAM and ANSYS CFX and compared with available experimental data. The investigated operating range extends from $0.7Q_{\mathrm{BEP}}$ to $1.3Q_{\mathrm{BEP}}$. A mesh independence analysis is first carried out using the Grid Convergence Index method, leading to the selection of a mid-size computational mesh as a compromise between accuracy and computational cost. The transient OpenFOAM results show close agreement with the ANSYS CFX predictions over the complete operating range. Both numerical frameworks reproduce the experimental hydraulic-efficiency trend and the location of the BEP, while systematic deviations in hydraulic head and mechanical power are mainly attributed to the geometrical and physical simplifications adopted in the common computational model. The local pressure coefficient monitored at the tongue region shows that both the mean pressure level and the fluctuation amplitude increase with flow rate, indicating stronger transient behavior under high-flow conditions. Beyond the global performance comparison, the flow field is analyzed using $Q_{crit}$ iso-surfaces, mean circumferential velocity, the swirl-intensity parameter $S_{\mathrm{int}}$, relative velocity fields at the PaT operational leading edge, and volute head-loss evaluation. The results show that part-load operation is characterized by strong outlet vortical structures and high residual swirl intensity, while the BEP region corresponds to reduced outlet rotational content. Under overload conditions, the outlet swirl remains limited, but the volute head loss increases significantly, becoming a dominant contributor to the efficiency drop. The study demonstrates that PaT performance cannot be interpreted from outlet swirl alone, but results from the combined effect of residual rotational structures, tongue-region unsteadiness, impeller incidence conditions, and volute dissipation. Full article

This study obtained the energy levels and examined the partition function (Z) of a quantum system described by an Eckart-like potential model. By adopting the Greene–Aldrich approximation scheme for the centrifugal term, the radial Schrödinger equation (SE) is solved and the analytic expression of the energy eigenvalues is obtained. The ro-vibrational Z is computed by explicitly incorporating the rotational quantum number, a feature often neglected or misapplied in many studies. This result is used to evaluate the key thermodynamic properties (TP), including the Gibbs free energy (G), entropy (S), and enthalpy (H). Numerical analysis reveals that the Z increases monotonically with temperature, while the G decreases in accordance with statistical thermodynamics. The S exhibits saturation-like behaviour at higher temperatures, while the H displays convex growth with increasing thermal energy. Parametric studies demonstrate that the Eckart-like potential allows for the controlled tuning of TP, with variations in the potential parameters, including the screening parameter, having distinct effects. The results generalise existing models, reproduce the Hulthén potential under specific conditions, show the effect of the rotational quantum number of TP, and provide new insights into the ro-vibrational statistical mechanics of exponential-type potentials. Full article