Search Results (5,873)

Hydrodynamic cavitation (HC) is an energy-efficient pretreatment technology; however, few studies have directly applied it to food waste (FW). Most HC modeling approaches simplify the cavitating medium as water, whereas FW exhibits non-Newtonian rheology, which may introduce deviations in cavitation simulation. In this study, the rheological properties of FW with different total solids (TS) were measured, and a CFD model of FW-HC in a Venturi reactor was developed. Simplifying FW as water (TS = 0 wt%) underestimated viscosity within the Venturi tube and overestimated the low-pressure region. For FW at TS = 5, 10, and 20 wt%, the relative root means square error (RRMSE) in average vapor volume fraction, relative to TS = 0 wt%, was 31.8%, 36.1%, and 61.5%, respectively. This simplification also led to a lower model-predicted critical pressure for cavitation inception and produced different predictions of the turbulent viscosity ratio (TVR). When non-Newtonian rheology was incorporated, increasing TS significantly elevated FW viscosity and produced high-viscosity regions in the throat and diffuser. These regions restricted the development of the low-pressure zone, thereby suppressing cavitation. Analysis of vapor volume fraction and TVR indicated that high-TS FW required a higher critical pressure for cavitation, whereas moderate dilution or increased pressure drop enhanced HC in FW. Full article

Conventional chemical gel plugging materials often suffer from poor high-temperature stability and inadequate mechanical properties. To address these issues, this study developed a high-performance composite gel material using a multi-component hybrid crosslinking strategy. The material employs γ-methacryloxypropyltrimethoxysilane (MPTMS) as the silica source, which hydrolyzes in situ to generate SiO₂, thereby enhancing temperature resistance. Laponite nanoplatelets are incorporated as a toughening agent and physical crosslinking points, while a self-synthesized reactive microgel (BWL) serves as the organic crosslinking core. Through copolymerization with monomers such as acrylamide (AM) and methacrylic acid (MAA), a triple-crosslinked network structure is constructed. Compared with conventional gels, the synthesized hybrid crosslinked composite gel maintains a high storage modulus and loss modulus after aging at 140 °C and exhibits excellent tensile and compressive properties. Furthermore, the gel was processed into particle-based lost circulation materials with different particle sizes. High-temperature and high-pressure plugging experiments demonstrate that when using a mixed system of 40–60 mesh, 20–40 mesh, and 10–20 mesh gel particles with a total concentration of 2%, it can effectively seal highly permeable sand beds and fractures with apertures up to 5 mm. This meets the engineering requirements for lost circulation materials with high strength and high stability in deep, high-temperature formations. Full article

The global transition towards sustainable food systems has intensified the search for alternative protein sources that can meet human nutritional demands with reduced environmental impacts. Although microalgae are rich in protein, their applications in food remain limited due to thick cell walls and intense green color. The aim of this study is to modify Chlorella vulgaris by high-pressure homogenization (HPH) and decolorization to improve its processability for extrusion-based 3D printing. Microalgal biomass was pretreated by HPH at different pressures (10,000, 15,000, 20,000 psi) for one to three passes, followed by pigment removal using ethanol of different concentrations (70, 85, 100%). Microscopic imaging shows that HPH effectively disrupted microalgal cell walls and caused cell disintegration, resulting in increased foaming stability (22–28%) but lower solubility (up to 24%), with other functional properties largely preserved. Ethanol treatments markedly decolored microalgae and increased their water-holding capacity (10–45%) and solubility (6–11%). The formulation of HPH-treated decolorized microalgae with soy protein isolate and xanthan gum increased the viscosity (66–179%) and elasticity (78–235%) of printing inks. The resulting 3D prints show higher hardness (47–128%), springiness (up to 155%) and chewiness (47–408%). The information obtained from this study provides guidance for modifying the functional and rheological properties of microalgae and contributes to advancing the formulation and manufacturing of microalgae-based foods. Full article

Formaldehyde emissions from urea–formaldehyde (UF)-bonded particleboards remain a significant environmental and health concern. This study evaluates the effectiveness of flours as bio-based formaldehyde scavengers in particleboard production. Food-based flours (soy, wheat, green pea) and feed flours (hemp, maize DDGS, feather meal) were incorporated into UF resin at concentrations of 0.3–2.0%. Resin characterization included pH, viscosity, gelation time, solid content, and free formaldehyde, while rheological behavior was monitored at 70 °C and 90 °C. The addition of flour decreased pH from 9.1 to 7.9 and increased viscosity from 414 to up to 1600 cP, depending on flour type and dosage. Free-formaldehyde content was reduced from 0.17% to as low as 0.08%, with the most effective reduction observed for hemp flour. At industrial scale, particleboards produced with 0.5% soy and hemp flours significantly reduced free formaldehyde, with emission values of 3.26 mg/m² and 3.05 mg/m², corresponding to reductions of 66–70% compared to the reference (3.97 mg/m²). Mechanical properties, including density (652–665 kg·m⁻³), bending strength (13.2–14.1 N·mm⁻²), and internal bond (0.42–0.45 N·mm⁻²), were maintained within acceptable limits. While feed flours such as feather meal showed strong scavenging potential, they caused significant viscosity increases (up to 1800 cP), limiting processability. These findings demonstrate that adding low levels of flour, particularly soy or hemp, is an effective, renewable, and low-cost strategy to reduce formaldehyde emissions in UF-bonded particleboards, supporting the production of safer and more sustainable wood-based composites. Full article

Against the backdrop of the global trends toward lightweighting, multi-functionalization, and greening of materials, polypropylene (PP) has been extensively applied owing to its advantages of low density and low cost. However, its inferior foaming performance fails to meet high-end application requirements, which is primarily attributed to its low melt strength and restricted crystallization behavior. In this paper, the five-dimensional selection mechanism and classification of components for PP micro/nanocomposites fabricated via supercritical foaming are systematically summarized. The regulatory effects of micro/nano additives on the crystallization, rheological properties, and foaming behavior of PP are quantitatively analyzed. The parameter optimization windows of three foaming processes, namely batch foaming, extrusion foaming, and injection foaming, are integrated (e.g., a foaming temperature of 150–170 °C and a saturation pressure of 8–20 MPa). Additionally, the application progress of PP micro/nanocomposite foams in fields such as automotive lightweighting (with a weight reduction rate of 64.29%) and building thermal insulation (with a thermal conductivity as low as 29 mW/(m·K)) is outlined. The core novel insight of this work lies in clarifying the unified mechanism of crystal refinement induced by reinforcing agents with different geometric morphologies, which is dominated by the synergy between heterogeneous nucleation and steric hindrance. This finding provides theoretical and technical guidelines for the industrial-scale preparation of high-performance PP foams. Full article

Fiber-reinforced cemented tailings backfill (FTB) has been widely adopted in underground mining operations as an effective solution for mitigating the brittleness of cemented tailings backfill (CTB) and ensuring compatibility with deep mining environments. Understanding the coupled effects of temperature and binder composition on the thermal–hydro–mechanical–chemical (THMC) behavior of FTB is essential for low-carbon mix design and practical application. To address this knowledge gap, this work presents a systematic investigation into the influences of curing temperature, binder type, and cement content on the rheological properties, compressive strength, and THMC-related parameters of FTB. The results demonstrate that elevated temperatures accelerate hydration, reducing flowability while significantly enhancing strength and pore structure refinement. Conversely, low temperatures preserve flowability but impede strength development. The incorporation of slag or fly ash as partial cement substitutes reduces rheological parameters; however, fly ash substitution tends to compromise ultimate strength. Multi-field performance monitoring further reveals the underlying coupling mechanisms among temperature evolution, hydration kinetics, matric suction, and mechanical strength development. Based on these insights, a low-carbon design strategy is proposed, emphasizing dynamic optimization of cement content according to ambient temperature. These findings offer a theoretical foundation for the sustainable proportioning and performance control of mine backfill materials. Full article

This research-related study examines the relevance of mud pulse telemetry (MPT) systems and their intersection with drilling performance, focusing on data transmission signal propagation performance and overall operation under different drilling parameters conditions, with an additional focus on drilling fluid flow rate and downhole pressure conditions. The novelty of this study lies in the investigation of adjustments to drilling operating parameters that could potentially improve the transmission of telemetry signals during drilling, in real time, without requiring mechanical or functional modifications to the MPT system itself. Improvements on transmission performance in situations where the data rate may be limited are also addressed, presenting an alternative through possible propagation velocity improvements to counterbalance it. A detailed chronological technical scientific literature review details important parts on analyses of pressure pulse propagation velocities focused on data transmission. A systematic experimental approach was developed and put into practice to evaluate the MPT systems in regard to tendencies on transmission performances, emphasizing pressure pulse propagation velocity. The laboratory-scale experiments were conducted at the Institute of Drilling Engineering and Fluid Mining (IBF) from the Technical University Bergakademie Freiberg (TUBAF), namely the Flow-loop Research Facility, to assess the impact of fluid flow rate (and subsequent pressure) on data transmission efficiency. Experimental results demonstrate that increasing the flow rate significantly speeds up signal propagation. In the performed experiments, for the mud siren configuration, increasing the flow rate from 15 to 25 m³/h improved the data transmission performance by approximately, at minimum, 18%, while for the positive mud pulse system, an increase in flow rate from 11.5 to 14 m³/h resulted in a propagation velocity rise of about 19%. The results also showed that higher concentrations of glycerin in the working fluid reduced the propagation velocity, confirming the influence of the fluid’s rheological properties on telemetry performance. At the end, in the presented case study, for 6 bps data rate configurations and for a transmission of a 40-bit string, it was demonstrated that the propagation time from downhole to the surface could potentially represent approximately 40% of the total time demanded for transmitting the desired information (generation plus propagation time). It was verified that an increment of 0.02208 m³/s (350 gpm) could lead to shortening eventual surveying procedures by 1–2 s, and that it could equally represent 1.137 bps. This is a relevant outcome, since, without any physical or functional alteration to the MPT system, one could have the data transmission performance improved, an approach not yet analyzed in the literature nor at the industrial park. These results, added to the detailed literature investigation and interaction with field personnel, indicate that the drilling fluid flow rate is a critical operational parameter affecting both the telemetry signal transmission speed and the overall drilling efficiency. Increasing the flow rate can reduce survey transmission time and decrease operational exposure to drilling hazards, such as drill string sticking. The results provide quantitative information applicable in optimizing measurement-drilling telemetry and help support the development of integrated drilling optimization strategies that balance drilling performance with real-time data transmission assurance in deep drilling operations. Full article

This study systematically investigates the formulation–property relationships of epoxy-based silver conductive adhesives by varying silver filler architecture, total filler loading, and organic carrier design. Rotational viscometry, four-point probe measurements, thermal conductivity analysis, and scanning electron microscopy (SEM) were employed to elucidate the correlations among rheological behavior, conductive network formation, and electrical–thermal transport properties. All formulations incorporate dicyandiamide (DICY) as a latent curing agent, in combination with a thermally activated accelerator and silane coupling agents, to stabilize filler–matrix interfaces and suppress moisture-assisted side reactions. This latent curing chemistry enables effective low temperature curing at approximately 155 °C, providing compatibility with temperature-sensitive flexible polymer substrates. After sealed storage at 25 °C and 60% relative humidity for two weeks, all formulations exhibited viscosity variations within ≤16%, demonstrating extended pot life and good storage stability under ambient conditions. Meanwhile, the normalized volume resistivity and thermal conductivity remained close to their initial values, with maximum relative deviations of approximately 12% and 7%, respectively, from the initial (Day 0) values across all formulations, indicating stable electrical and thermal transport properties during storage. Differences in conductive network formation and filler packing characteristics were reflected in the observed electrical and thermal transport behaviors. Balanced electrical–thermal performance was achieved without the need for high-temperature sintering or post-annealing, underscoring the effectiveness of the low temperature curing strategy. Overall, this work defines a practical formulation design window that simultaneously achieves low temperature curability, long pot life, stable rheology, and robust electrical–thermal performance. The results provide useful material-level guidelines for the development of epoxy-based silver conductive adhesives intended for conductive interconnects on flexible polymer substrates and related flexible electronic applications. Full article

Background/Objectives: Atopic dermatitis (AD) is associated with gut dysbiosis linked to early-life antibiotic use and Staphylococcus aureus colonization. Gum Arabic (GA), a prebiotic, may modulate this dysbiosis and influence AD-related microbial balance. This study evaluated whether GA could support AD-associated probiotics-Lactobacillus casei, Bifidobacterium bifidum, and Bifidobacterium infantis-under amoxicillin- or azithromycin-containing conditions, examined the response of S. aureus under the same screening conditions, and developed GA-phospholipid-based semisolid carriers for topical application. Methods: Probiotic strains were cultured with 1–5% GA in the presence and absence of antibiotics, and viable cell counts were assessed. Sixteen topical formulations containing propylene glycol or isopropyl myristate in a hydrogenated phosphatidylcholine base were prepared and screened for rheological properties and galactose release using in vitro release testing (IVRT) and HPLC-UV. Results: GA at 1–2% concentrations promoted probiotic growth in antibiotic-free conditions. GA preserved B. infantis viability under azithromycin exposure in this in vitro screening model. For S. aureus, numerical CFU differences were observed between antibiotic-only and GA-containing conditions; however, the present screening design was not intended to determine antibiotic interaction outcomes. Formulations F14 (2% GA + 7% IPM) and F15 (3% GA + 7% IPM) exhibited optimal spreadability. IVRT showed that 6 h cumulative galactose release varied by formulation (F6 > F10 > F14 > F15). Conclusions: GA demonstrated dose-dependent prebiotic activity and preserved B. infantis viability under azithromycin exposure in this in vitro screening model. For S. aureus, the observed CFU differences between antibiotic-only and GA-containing conditions should be considered exploratory only and do not allow for conclusions regarding interference with antibiotic efficacy. Optimized GA-HPC systems with suitable rheological and release characteristics represent promising candidates for further preclinical investigation. Full article

In response to the shortcomings still observed in polyethylene (PE)/ethylene-vinyl acetate (EVA)/styrene-butadiene-styrene (SBS) composite modified bitumen regarding storage stratification and low-temperature performance, this paper further introduces furfural extract, elemental sulphur, stabilisers and Z-6036 into this ternary system, and employs orthogonal design to screen the additive ratios. Tests were conducted on conventional physical properties, rotational viscosity, dynamic shear rheology and bending beam rheology, focusing on the material’s temperature sensitivity, rheological behaviour, low-temperature creep resistance and phase characteristics. The modification effects were analysed using fluorescence microscopy, scanning electron microscopy and infrared spectroscopy. Compared with the control group composed of 4% PE, 4% EVA and 2% SBS, the samples obtained from the orthogonal design showed an increase in elongation at 5 °C ranging from 52.5% to 213.9%; the difference in softening points decreased from 35.2 °C to a minimum of 0.1 °C, indicating improved storage stability. The temperature sensitivity of all sample groups was reduced, with the optimal group achieving a VTS of −0.4413, representing a 46.7% improvement over the control group. At −12 °C, the m-values of all nine orthogonal samples were higher than those of the control group, with seven groups reaching m ≥ 0.3, indicating improved low-temperature stress relaxation capability. A comprehensive analysis of the experimental results indicates that the selected chemical additives are beneficial for optimising the dispersion state and compatibility of the SBS/PE/EVA ternary modified bitumen, whilst also balancing rheological properties and low-temperature crack resistance to a certain extent. Microscopic and spectroscopic analyses further suggest that internal interactions within the system have been enhanced and the phase distribution has become more uniform; however, the current evidence is insufficient to conclusively determine that a specific form of chemical cross-linking reaction has occurred. Full article

This study investigates the dripping and leakage problem in kitchenware known as the “teapot effect” through a multidisciplinary experimental approach encompassing fluid mechanics, material science, and ergonomic design. Unlike previous studies confined to idealized geometries and single-fluid analyses, this work systematically examines 32 distinct spout geometries from commercially available teapots, coffee pots, and milk jugs under realistic operating conditions. Experiments were performed using three fluids with contrasting rheological properties: boiling black tea, cow’s milk, and Turkish coffee on a precision rotating platform operating at quasi-static (1°/s) to isolate surface tension, gravitational, and geometric effects from inertial forces. Three quantitative parameters were measured for each specimen: capillary dome angle, teapot effect angle range, and optimum pouring angle. Results demonstrate that spout tip geometry is the dominant controlling parameter. Thin-lipped elliptical cross-sections effectively suppressed dripping, whereas triangular and wide curved geometries produced the teapot effect across broad pouring angle ranges reaching up to 70°. A spout outlet extension length of 4–5 mm combined with a spout tip radius below 4 mm was found necessary and sufficient for clean flow separation. Furthermore, suspended particles and proteins in milk and Turkish coffee were shown to intensify the teapot effect by disrupting contact line dynamics at the spout tip. These findings provide quantitative design thresholds directly applicable to industrial kitchenware development. Full article

Konjac glucomannan (KGM) is a naturally derived polysaccharide known for its biocompatibility and gel-forming ability and has gained increasing attention in biomaterial and drug delivery research. However, the rheological behavior of KGM gels at clinically relevant concentrations for periodontal use has not been thoroughly investigated. In this study, KGM gels at 0.8%, 1.0%, and 1.2% (w/v) were prepared and evaluated using oscillatory and steady shear rheology. Rheological analysis revealed increased viscoelastic strength with increasing polymer content, with the 1.2% formulation showing the highest storage modulus, viscosity, and shear stress values across strain, frequency, and temperature ranges. All formulations demonstrated pronounced shear-thinning behavior and dominant elastic characteristics (G′ > G″), indicating stable gel network formation and favorable injectability. The viscoelastic profile remained stable near physiological temperature (37 °C), implying that the gel network can preserve mechanical integrity under intraoral conditions. Gamma irradiation at 15 kGy effectively achieved sterility without visible macroscopic instability, although a qualitative reduction in viscosity was observed. Collectively, these findings indicate that increasing KGM concentration improves mechanical robustness and viscoelastic stability, with the 1.2% gel demonstrating the most favorable rheological profile for potential localized periodontal application. Full article

Extrusion-based bioprinting requires hydrogel materials with suitable rheological behavior, structural stability, and bio-related properties; however, the relationships among composition, network structure, and printing performance in multicomponent hydrogel systems remain insufficiently understood. In this study, a GG/SS/PVA/GEL composite hydrogel was developed and optimized using single-factor experiments combined with Box–Behnken response surface methodology. Rheological analysis, Fourier transform infrared spectroscopy, and scanning electron microscopy were further used to characterize the optimized system. The optimal formulation was identified as 0.14 g of GG, 0.60 g of SS, and 2.3 g of PVA. This formulation achieved a comprehensive score of 87 with a prediction error of less than 5%. The optimized hydrogel exhibited pronounced shear-thinning behavior, a printing fidelity of 98.6–101.4%, a maximum swelling ratio of approximately 403.5%, and an enzymatic degradation rate of 68.5%, together with a relatively uniform interconnected porous structure. These results indicate that the optimized composite hydrogel is a promising printable material candidate and provide a useful basis for formulation design in extrusion-based hydrogel systems. Full article

The paper investigates the effect of the degree of HIPS surface yellowness on its properties: colorimetric, surface, rheological, and mechanical. In order to prepare three naturally degraded samples, about 1 kg of white HIPS flakes, semi-yellow HIPS flakes, and yellow HIPS flakes, segregation based on colorimetric analysis was applied. Then, these samples were subjected to ATR-FTIR analysis, sessile drop contact angle measurements, and MFI analysis. These analyses were repeated for standardized specimens made of the segregated HIPS flakes. The average absorbances were determined for 50 HIPS samples of each type in the form flakes. Finally, mechanical tests were carried out on the standardized specimens. As follows from the research, yellowing of the HIPS surface affects the final color of the standardized specimens, which is confirmed by optical colorimetry. Moreover, material degradation demonstrated by yellowing of its surface and confirmed by a decrease in ATR-FTIR spectra absorbance, is associated with changes in mechanical and rheological properties, as well as in surface characteristics. The novelty of this study lies in the investigation of naturally degraded HIPS samples under laboratory conditions (the HIPS materials were not subjected to artificial aging using laboratory equipment), obtained from waste post-consumer cooling devices used in consumers’ homes, representing natural wear and tear of the material. The tests provide insight into both the visual and mechanical properties of components manufactured from recycled HIPS originating from degraded refrigeration equipment. They also constitute a valuable source of information for processors and manufacturers. Full article

In the current study, bioactive-loaded hydrogels were developed with k-carrageenan (1%), and water was replaced with infusions of Urtica dioica L., which modulated the polymer chains to create more robust networks. Urtica dioica L. infusions were obtained with different infusion durations (5 or 10 min) or plant-to-water ratios (0.4, 1, or 2 g/100 mL). The hydrogels were characterized for stability by assessing the syneresis rate and textural and rheological attributes. To elucidate the influence of the infusion on the mechanisms of k-carragenan, temperature ramp tests were applied and FTIR spectra were acquired. Replacing water with Urtica dioica L. infusions for obtaining k-carrageenan hydrogels led to lower syneresis rates (3.34 ± 0.03% and 6.67 ± 0.33%), while the hydrogels showed increased hardness, but lower resilience and cohesiveness. The rheological parameters confirmed the reinforcement; higher G′ and gelling temperatures were registered compared to the reference. While FTIR spectra showed that the primary chemical backbone remained intact, the physicochemical changes indicate a strong physical synergy between nettle polyphenols and the κ-carrageenan chains. Of all samples, the highest antioxidant potential value of 94.66% was exhibited by the infusion obtained in 15 min with a ratio of plant material of 2/100 g. These findings demonstrate that plant-to-water ratios and infusion times are critical parameters for tuning the physical properties and biological efficacy of hydrogels for medical or food applications. Full article