Search Results (340)

The foaming of hydrogels presents a promising strategy for tailoring mechanical and radiological properties to replicate biological soft tissues for biomedical phantom applications. A computational fluid dynamics (CFD) framework is developed to predict void fraction distribution in alginate hydrogel precursor solutions aerated by air injection through a bottom nozzle. The objective is to use the framework for the design of the foaming system to match the desired gas-fraction distribution and radiological property. Seven parametric cases are investigated, varying inlet air velocity, alginate concentration, and surface tension. Results show that higher inlet velocities promote stronger jet penetration and greater gas accumulation, while increasing alginate concentration confines the bubble plume, with quasi-steady gas fractions displaying a non-monotonic trend with concentration. Elevated surface tension yields broader plume coverage and improved gas distribution uniformity at the expense of peak void fraction. The predicted void fractions map to Hounsfield Unit (HU) values of −34 to −103, corresponding to adipose and fatty breast tissue attenuation (−50 to −150 HU). The peak gas fraction at 5.0 wt% alginate yields −307 HU, approaching published experimental CT measurements for the same formulation (−460 to −233 HU). Full article

Pitch-based foam carbon, a novel lightweight material, boasts excellent mechanical and thermoelectric properties, and tantalum film deposition on its surface can further enhance its performance. However, this deposition process often suffers from non-uniform deposition and suboptimal coating quality. To address these issues, this study systematically optimized the furnace structure by tuning pipe diameter, tilt angle, and porous media height. Numerical simulations of 216 models were conducted to evaluate the effects of these parameters on axial velocity, turbulence intensity (quantified by the vortex criterion Q > 1), and reactant concentration uniformity. The results showed that pipe diameters below 70 mm increased the mean axial velocity by 8-fold compared to larger diameters, whereas tilt angles of 15° and porous media heights of 60–80 mm yielded limited velocity enhancements of only 2%. Pipe diameter was identified as the dominant factor governing flow stability, inducing up to a 300% variation in the volume fraction of Q > 1, with minimal turbulence observed at the maximum diameter. In contrast, adjustments to tilt angle and porous media height had weaker effects, altering the Q > 1 volume fraction by 26% and 5%, respectively. Smaller pipe diameter (70–80 mm) also optimized TaCl₅ concentration uniformity; tilt angles between 0° and 30° showed negligible influence, while porous media height exhibited no definitive trend. Guided by the practical priorities of process evaluation, a multi-objective optimization was performed. The globally optimal structural parameters were determined to be a pipe diameter of 70 mm, a tilt angle of 15°, and a porous media height of 60 mm, which comprehensively balance deposition uniformity, process stability, and deposition efficiency. These findings establish pipe diameter as the pivotal factor for deposition homogeneity and provide a reference scheme for the structural design of industrial tantalum deposition furnaces and lay a foundation for subsequent multi-physics coupling studies and experimental validation. Full article

Per- and polyfluoroalkyl substances (PFASs) include thousands of fluorinated organic compounds of anthropogenic origin. Their extensive use, combined with their high stability, has led to the widespread contamination of water and soil resources. Here, single-step foam fractionation enhanced soil washing was carried out for the remediation of PFAS-contaminated soil. Concentrations of target Perfluoroalkyl Carboxylic Acids (PFCAs) and Perfluoroalkane Sulfonic Acids (PFSAs) were monitored in foam and leachate along the duration of the treatment. Among PFCAs, only long-chain compounds peaked in foam at the beginning of the treatment. This was consistent with the increase in the sorption affinity to the air–water interface with chain length. The same behavior was observed also in PFSAs by comparing PFHXs, PFHpS and PFOS. The fraction of PFCAs still in the leachate after 40 min of treatment was found to decrease with chain length, with PFSAs showing a similar trend. PFAS removal significantly increased with soil particle size, ranging from 48.2 ± 3.2% (fraction < 0.063 µm) to 64.1 ± 1.9% (fraction > 2 mm). Final mass balance analyses detail PFAS distribution among soil, leachate, and foam, providing valuable information for the additional treatment required to destroy the PFAS load extracted from the contaminated soil. Full article

Urban underground construction in water-rich sandy strata produces large quantities of high-fluidity pipe-jacking spoil whose high water content, residual conditioning agents and heavy metal contaminants make conventional dewatering and landfilling increasingly unsustainable under carbon peaking and neutrality targets. This study explores a low-carbon route that converts such spoil into CO₂ foamed concrete through a coupled alkali activation–CO₂ foaming process. Ground granulated blast furnace slag and fly ash are used as geopolymer precursors, while a CO₂-based aqueous foam is introduced as both a pore-forming phase and carbon source. Single-factor tests and an L16(4⁴) orthogonal design are conducted to quantify the effects of CO₂ concentration, foam volume fraction, geopolymer dosage and alkali activator content on fluidity, setting time and compressive strength. Scanning electron microscopy (SEM) is employed to examine pore structure, gel morphology, carbonate precipitation and the interfacial transition zone around spoil particles. The results identify an optimum mix window (CO₂ 60–80%, foam 70–80%, geopolymer ≈ 20% and alkali activator ≈ 10% of solids) that delivers a fluidity above 210 mm, 28-day strength exceeding 3.0 MPa and a uniform closed-pore network. A multi-scale mechanism is proposed in which physical foaming, chemical carbonation and spoil particle immobilization act synergistically to form a dense gas–solid–soil composite suitable for in situ backfilling. Full article

Natural gas streams extracted from production wells often contain undesirable components such as water vapor, gas condensate, and solid particulates. These impurities reduce fuel quality and damage downstream equipment through corrosion, fouling, and foaming. This study presents the development and field-scale evaluation of a high-performance gas–liquid separator designed for the deep decontamination of natural gas. The proposed separator incorporates 30 suspended baffles arranged in three rows and an anti-foaming mesh to enhance phase separation and prevent liquid re-entrainment. Field experiments were conducted at the Somontepa gas field in Uzbekistan. Compared to the baseline industrial unit, the upgraded separator reduced gas condensate from 16.58 g/m³ to 0.725 g/m³, water from 4.84 g/m³ to 0.10 g/m³, and solid impurities from 1.20 g/m³ to 0.0058 g/m³. The foam height was lowered from 96.4 mm to 10.2 mm, and the average bubble diameter was reduced by over 60%. The design maintained low pressure drops and demonstrated stable operation under varying flow rates. Fractional analysis confirmed the quality of a recovered condensate suitable for downstream utilization. The proposed configuration offers substantial improvements in gas purification performance and economic efficiency. These results support the application of this separator design for high-contaminant natural gas streams in industrial gas processing facilities. Full article

The integrated valorization of whey into multifunctional food ingredients is constrained by sequential processing routes and the need for purified lactose and protein fractions. The simultaneous enzymatic conversion of lactose and whey proteins in a single reactor remains underexplored despite the frequent co-formulation of galacto-oligosaccharides (GOS) and whey protein hydrolysates in functional foods. This study evaluated the feasibility of a one-pot enzymatic system using native whey as the sole substrate for the concurrent production of GOS and antioxidant peptide fractions. A batch process combining β-galactosidase from Aspergillus oryzae and Alcalase^® was assessed through a 3² factorial design, analyzing the effects of pH (4.5–6.5) and temperature (40–60 °C) on GOS yield and degree of protein hydrolysis. The system enabled simultaneous transgalactosylation and proteolysis under mildly acidic conditions without significant mutual enzyme inhibition. Multi-response optimization identified pH 6.0 and 59.5 °C as the optimal conditions, yielding 25.7 ± 0.2% GOSs and 10.5 ± 0.3% protein hydrolysis. The antioxidant capacity and emulsifying and foaming properties were strongly dependent on pH, temperature, and reaction time. The results demonstrate that native whey can be directly transformed into a multifunctional ingredient through a one-pot enzymatic strategy, offering a simplified valorization approach. Full article

This study investigated the temporal variation and removal efficiency of solid waste, together with the dynamics of water quality parameters and microbial community structure, in a recirculating aquaculture system (RAS) for mandarin fish (Siniperca chuatsi) fed a formulated diet. The average fish weight was 384.62 ± 12.13 g, and the stocking density was 25 kg/m³. The results showed that: (1) the contents of the stomach and intestine exhibited a bimodal pattern, characterized by an initial increase followed by a decrease, and a subsequent secondary increase and decline. In the culture tanks, the total suspended solid (TSS) concentration at the main discharge outlet of the dual-channel bottom drainage system was highest immediately after feeding (0 h), reached its lowest level at 5 h post-feeding, and displayed a double-peak pattern during the 6–24 h post-feeding period. The temporal variations of in-tank TSS and chemical oxygen demand (COD) generally followed the same trend as the TSS concentration at the main discharge outlet. (2) Total ammonia nitrogen (TAN) reached its maximum at 6 h, whereas nitrite nitrogen (NO₂⁻-N) peaked at 9 h. (3) The solid–liquid separation efficiencies of the dual-drain system, vertical flow clarifier, and Rotating drum microfilter were 30.40–58.33%, 51.30–76.61%, and 37.04–68.26%, respectively, with the highest removal efficiencies observed at 0 h post-feeding. (4) In the nitrifying biofilter, the TAN concentrations ranged from 0.22–0.99 mg/L at the inlet to 0.15–0.36 mg/L at the outlet. In contrast, NO₂⁻-N concentrations exhibited negligible differences between the inlet and outlet at the corresponding sampling times. At the phylum level, Pseudomonadota, Bacteroidota, and the superphylum Patescibacteria dominated the biofilter microbial communities. At the genus level, Sediminibacterium and Limnohabitans were predominant in BF_1, whereas taxa affiliated with norank_f__Hyphomicrobiales_ and unclassified_o__Saccharimonadales dominated BF_2. Overall, the results indicated that increasing water circulation and tank flow rate at 0 h and during the 7–14 h post-feeding period may facilitate the timely removal of solid waste, and that the installation of a foam fractionator could contribute to the removal of dissolved and fine organic matter. Full article

To meet the miniaturized cooling demands of high-heat-flux electronic devices, metal foams—featuring high specific surface area and multiscale porous structures—are considered promising candidates for enhancing flow boiling evaporation. However, pore density (PPI) and grooved geometry (channel aspect ratio, AR) jointly regulate vapor–liquid distribution, rewetting, and flow resistance, thereby constraining overall performance. Here, flow boiling experiments were conducted on nickel and copper foams with pore densities of 100, 500, and 1000 PPI and AR values of 0.7, 1.0, and 1.3. Heat transfer coefficient (HTC), wall superheat ($\mathsf{\Delta }T$), and pressure drop ($\mathsf{\Delta }p$) were systematically evaluated, complemented by transient two-phase simulations revealing vapor fraction, temperature, and pressure drop distributions. A pronounced non-monotonic pore-density dependence is observed: 500 PPI achieves an optimal balance between heat-transfer enhancement and flow resistance, whereas 100 PPI suffers from vapor accumulation and temperature non-uniformity, and 1000 PPI is penalized by excessive permeability resistance and pore-scale confinement. An optimal AR of 1.0 promotes efficient vapor venting and stable rewetting. Under the optimal configuration (500 PPI, AR $=1.0$), a limiting heat flux of 348.6 W/cm², corresponding to the HTC of 55.4 kW/(m² · K), and a limiting HTC of 130.3 kW/(m² · K) are achieved, providing quantitative design guidelines for metal-foam two-phase evaporators. Full article

Through-plane electronic transport in porous membrane electrode assembly (MEA) electrodes is governed by the three-dimensional (3D) connectivity of the conducting phase. Here, we quantify the role of the spanning-cluster fraction $P_{\infty }$, defined as the fraction of conducting-phase voxels that belong to the $z$-spanning connected component in a finite reconstructed volume, on effective conductivity using scanning electron microscopy (SEM)-informed 3D reconstructions of four archetypal morphologies: a granular catalyst layer (CL), labeled CL1; a fibrous gas diffusion layer (GDL), labeled GDL1; an open-cell foam (OCF); and a micro-fibrous non-woven (MFM), labeled MFM1. Each morphology is reconstructed on a $150\times 150\times 150$ voxel grid, and $z$-spanning connectivity is identified with a 26-neighbor flood-fill algorithm. Steady-state conduction is solved by a finite-volume method (FVM) with an imposed potential difference between the z-faces and no-flux lateral boundaries. Although all samples exhibit through-thickness connectivity, the normalized conductivity ${\sigma }_{\mathrm{e}\mathrm{f}\mathrm{f}}/{\sigma }_{\mathrm{b}\mathrm{u}\mathrm{l}\mathrm{k}}$ varies widely, from $\approx 0.134$ (MFM1) to $\approx 0.706$ (OCF). The corresponding ${(P}_{\infty },{\sigma }_{eff}/{\sigma }_{bulk})$ pairs are $\left(0.996,\approx 0.306\right)$ for CL1, $\left(0.999,\approx 0.303\right)$ for GDL1, $\left(0.997,\approx 0.706\right)$ for OCF, and $\left(0.901,\approx 0.134\right)$ for MFM1. OCF exhibits the highest response due to vertically coherent channels, whereas MFM1 underperforms due to laminated constrictions; CL1 and GDL1 lie in an intermediate regime with nearly isotropic skeletons. Overall, the results show that while a $z$-spanning connected component is required for measurable conduction, the magnitude of ${\sigma }_{\mathrm{e}\mathrm{f}\mathrm{f}}$ is dictated by percolating-skeleton quality (bottlenecks, cross-sectional constrictions, and pathway alignment) rather than phase amount alone. The proposed descriptors therefore enable percolation-aware screening metrics for designing and comparing MEA-relevant GDL and CL microstructures. Full article

Per- and Polyfluoroalkyl substances (PFASs) are commonly detected in airport stormwater runoff due to historical and ongoing use of aqueous film-forming foams (AFFFs). Conventional stormwater control measures (SCMs) are generally effective at removing PFASs associated with the particulate fraction, but may provide limited removal of dissolved-phase PFASs. Sorbent polishing beds represent a potential downstream treatment option; however, their applicability and performance for PFASs in stormwater have not been well studied. In this study, measured PFAS concentrations and runoff volumes from an AFFF-affected airport apron were combined with literature-derived sorption parameters to develop a screening-level framework for evaluating adsorber beds as polishing units for SCM effluent. Bed sizing was calculated using a representative empty bed contact time (EBCT) of 10 min and a design volume based on the 85th percentile storm event. Sorbent performance was evaluated using literature equilibrium partition coefficients (K_d) for activated carbons, ion exchange resins, and specialty materials to estimate operational lifetimes prior to regeneration or replacement. Model-based results indicated lifetimes ranging from approximately 7 years for activated carbon to more than 50 years for specialty materials, depending on PFAS chain length and affinity. Sensitivity analysis using quartile K_d ranges showed predicted lifetimes spanning orders of magnitude, emphasizing the screening-level nature of the estimates. This work links field monitoring data with conceptual adsorber design to support early-stage evaluation of sorbent polishing strategies for airport runoff management, supporting compliance under tightening discharge regulations. Full article

This study investigates how wheat arabinoxylan (AX) structure influences its functional properties following enzymatic hydrolysis with wheat malt β-1,4-endoxylanase. Using three types of wheat AX with initial molecular weights of 489.42–602.42 kDa, arabinose-to-xylose (A/X) ratios of 0.49–0.55, and average degrees of polymerization (avDP) of 1223.57–1506.05 as substrates, enzymatic cleavage produced four high-purity fractions with reduced molecular weight (98.63–301.42 kDa), increased A/X (0.60–0.65), and lower avDP (246.59–753.56). Enzyme action led to triple-helix unwinding, especially at low avDP, accompanied by reduced storage modulus. Molecular weight was the key factor affecting water-holding capacity and foam stability, with high-molecular-weight AX showing superior performance due to its intact helical structure and higher viscoelasticity. In contrast, low-molecular-weight AX with high A/X ratios exhibited enhanced interfacial adsorption and free radical scavenging, supported by greater hydroxyl exposure and higher negative charge density (−9.23 mV). Its emulsifying activity and hydroxyl radical scavenging rate increased by 32.95% and 32.02%, respectively, compared to the original AX. These findings demonstrate that enzymatic modulation of AX molecular weight and branching can directionally tune its functionality, providing a theoretical basis for targeted applications in food systems. Full article

Additive manufacturing, and particularly the vat photopolymerization process, enables the fabrication of complex geometries at high resolution and small length scales, making it well-suited for fabricating cellular structures (e.g., foams and lattices). Among these, elastomeric cellular structures are of growing interest due to their tunable compliance and energy dissipation. However, comprehensive data on the compressive behavior of these structures remains limited, especially for investigating the structure-property effects from changing the density and distribution of material within the cellular structure. This study explores how the mechanical response of polyurethane-based simple cubic structures changes when varying volume fraction, unit cell length, and unit cell patterning, which have not been systematically investigated previously in additively manufactured elastomers. Increasing volume fraction from 10% to 50% yielded significant changes in compressive stress–strain performance (decreasing strain at 0.5 MPa by 41.6% and increasing energy absorption density by 3962.5%). Although changing the unit cell length between 2.5 and 7 mm in ~30 mm parts did not result in statistically different stress–strain responses, modifying the configuration of struts of different thicknesses across designs with 30% volume fraction altered the stress–strain behavior (differences of 12.5% in strain at 0.5 MPa and 109.4% for energy absorption density). Power law relationships were developed to understand the interactions between volume fraction, unit cell length, and elastic modulus, and experimental data showed strong fits (R² > 0.91). These findings enhance the understanding of how multiple structural design aspects influence the performance of elastomeric cellular materials, providing a foundation for informing strategic design of tailorable materials for diverse mechanical applications. Full article

This study aimed to evaluate the substitution of wheat flour (WF) for grape (Vitis vinifera L.) pomace (GP) on cookie formulation. The techno-functional properties of GP flour (GPF) were characterized, and cookie formulations containing 15% (C15) and 20% (C20) GPF were developed. To evaluate the antioxidant and functional potential, free (FPF, soluble phenols) and bound phenolic fraction (BPF, insoluble phenols) were extracted. The total phenolic content (TPC) and antioxidant potential (ABTS and DPPH assays) were measured. The GPF shows differences in oil and water retention, non-foaming properties, and non-significant differences in swelling capacity compared to WF. C15 and C20 show L* values from 27.9 to 36.2, b* values from 2.22 to 2.64, and a* values from 8.84 to 10.49. GPF addition elevates ash and fiber content by 3.5–4.2 and 14–31.6 times. GPF cookie (C15) exhibited a significantly higher TPC compared to WF. Although the FPF fraction in the cookies was higher compared to BPF, the contribution of BPF to antioxidant activity was high (DPPH = 29.9%, ABTS = 16.3%) compared to FPF (DPPH = 26.3%, ABTS = 20.3%). Given that FPF is traditionally the only antioxidant fraction measured, the antioxidant potential of incorporating grape by-products is being underestimated; this is the first report of this in a cookie. Full article

Phycobiliproteins are recognized as potential bioactive compounds and described as highly valued natural products for industrial and biotechnological applications. Moreover, they have been observed to possess antioxidant, anticancer/antineoplastic, and anti-inflammatory activities. Therefore, the search for new methods of their extraction and isolation is still ongoing. Foam fractionation, a bubble separation technique that allows amphiphilic molecules to be separated from their aqueous solutions, is a promising but understudied method. The process may be carried out both under mild conditions that are suitable for proteins and also for diluted solutions. This paper presents the results of applying the foam fractionation process to concentrate and separate phycobiliproteins. Allo- and C-phycocyanin from a thermophilic Synechococcus PCC 6715 strain were used in extract form after biomass cultivation and disintegration. Two ways of running the process were investigated: batch mode and continuous mode, the latter of which has not been reported in the literature previously. The results indicate that the method can be applied on a larger scale, as the outcomes of the continuous mode processes were comparable to those of the batch mode. Moreover, the results indicate that the process provides, to a certain extent, the opportunity of separating phycobiliproteins from each other. Full article

Foamed concrete is a lightweight, environmentally friendly civil engineering material with excellent absorption capacity. It has been widely applied in engineering fields such as building thermal insulation and pore filling of underground buried pipelines. But the mechanical properties of existing foamed concrete cannot meet the engineering requirements for support, pressure relief and filling of weak surrounding rock. The mechanical properties of foamed concrete were improved with CNTs to prepare CNT foamed concrete (CNTFC) pressure-relieving filling materials. The effects of five factors (the fly ash (FA) incorporation rate, aggregate–cement ratio, water–binder ratio, CNT incorporation rate and foam volume fraction) on the density and 2:1 cylinder strength (the ratio of uniaxial compressive strength to apparent density), splitting tensile (the ratio of splitting tensile strength to apparent density) and specific strength of the CNTFC were analyzed. By combining stress–strain and scanning electron microscopy analyses, the mechanism of improvement of the mechanical strength of CNTFC due to CNTs was clarified. The results show that the foam volume fraction, water–binder ratio and aggregate–cement ratio are the top three factors affecting its strength, followed by the CNT incorporation rate and FA incorporation rate. Among the five influencing factors, only the incorporation of CNTs increases the 2:1 cylinder strength, splitting tensile strength and specific strength. When the doping rate is 0.05%, this ratio specifically refers to the mass of CNTs accounting for 0.05% of the mass of the total cementitious materials of cement and fly ash. At this doping dosage, compared with the condition without CNTs (0% doping dosage), the uniaxial compressive strength increased from 6.23 MPa to 7.18 MPa (with an increase rate of 15.3%). The splitting tensile strength increased from 0.958 MPa to 1.02 MPa (with an increase rate of 6.5%). The density only slightly increased from 0.98 g/cm³ to 1.0 g/cm³ (with an increase rate of 2.0%), achieving the balance of “high strength-low density”. CNTs and cement hydrates are interwoven into a network structure, and the mechanical properties of the CNTFC are effectively improved by the excellent nanoscopic tensile properties. Excessive doping of CNTs takes 0.05% as the threshold. Exceeding this doping dosage (such as 0.10% and 0.15%) leads to a decrease in its strength and ductility due to CNT agglomeration and deterioration of pore structure. And 0.05% is the ratio of the mass of CNTs to the total cementitious materials of cement and fly ash. At this doping dosage, CNTs are uniformly dispersed and can balance the strength and density of CNTFC. The optimum proportion of CNTs is 0.05%. Full article