Search Results (669)

In two-phase systems with heat transfer, developing tools that allow the analysis of interphase phenomena is crucial. In molten salt nuclear reactors, the fuel salt and helium in the core form a two-phase liquid–gas system. Understanding the heat transfer behavior between phases allows us to assess the impact of temperature changes in each phase as well as the feedback of neutron processes in the reactor. This work proposes using an upscaled heat transfer model to analyze the two-phase system, highlighting the importance of solving boundary value problems to obtain the closure variables in a unit cell with symmetry and periodicity. The closure variables are crucial for determining the heat transfer coefficients that exhibit the MSR’s scaled behavior. The coefficients are validated against the literature, and the results of the numerical experiments show that the cross-heat transfer coefficients exhibit symmetric properties. Full article

Background/Objectives: Propolis is well recognized for its antioxidant, anti-inflammatory, and wound-healing properties, supporting its cutaneous application in phytopharmaceuticals for the management of ultraviolet B (UVB)-induced skin damage. However, the application of propolis is limited by its intense coloration, stickiness, and poor user convenience. In situ film-forming systems (FFS) represent a novel dosage form designed to overcome these challenges, although efficacy data for using FFS remains limited. Consequently, this study aimed to develop a propolis-based FFS and evaluate its efficacy in mitigating UVB-irradiated HaCaT keratinocytes. Methods: Apis mellifera propolis was macerated and analyzed for total phenolic content (TPC) and total flavonoid content (TFC), radical scavenging activity (DPPH assay), and nitric oxide scavenging capability. Bioactive compounds were identified using high-performance liquid chromatography analysis (HPLC). The propolis extract was formulated into FFS and investigated on UVB-damaged HaCaT keratinocytes. An MTT viability assay, propidium iodide flow cytometry for cell cycle analysis, and a scratch wound healing assay were used to evaluate the therapeutic effects of the FFS. Results: The 72 h macerated propolis extract contained high levels of TPC, TFC, and targeted phytochemicals. The propolis extract exhibited free radical scavenging and nitric oxide inhibitory activities. Seven formulations exhibited suitable performance, with formulation F7 (FFS-F7) demonstrating superior drying time and dose-dependent free radical scavenging. Notably, FFS-F7 (≥12.5 µg/mL) significantly enhanced HaCaT proliferation, mitigated UVB-induced cell cycle arrest, reduced cellular damage, and accelerated wound closure. Conclusions: This study successfully developed an FFS that not only overcomes these physical drawbacks but also preserves the biological activity of the extract. The significant protective and restorative effects against UVB-induced HaCaT damage demonstrate the therapeutic potential of Thai Apis mellifera propolis and establish the FFS as a versatile base with the potential for delivering other bioactive compounds. Full article

Numerical simulation of sequential fracturing in horizontal wells for shale gas and oil extraction requires careful consideration of mechanical interactions between proppant and fracture surfaces—a challenge that remains largely unresolved. This study proposes a novel phase-field model featuring a strain-based formulation and a width-dependent proppant reaction force. Unlike previous studies, we integrate an empirical propped force solution, adapted from established work to account for rock properties and proppant support, to capture nonlinear fracture closure. Results show that reaction stress models significantly dictate propped geometry. The model’s fracture length, width, and closure predictions are validated against theoretical solutions. We conducted a sensitivity analysis to evaluate how fracture deflection angles and widths vary with dimensionless fracture spacing, in situ stress contrast, and proppant strength. Numerical results show that proppants induce pronounced morphological asymmetry and distinct geometric discrepancies. Specifically, the heterogeneous support provided by proppants and the resulting stress redistribution alter fracture propagation paths, leading to an 8% reduction in fracture length and a marked difference in fracture orientation of approximately 80° between supported and unsupported fractures, highlighting the important role of proppants in governing fracture geometry. Both dimensionless fracture spacing and in situ stress contrast strongly influence fracture deflection, with proppant strength also contributing. The propped-force formulation is further extended to nonplanar fractures, enabling application to sequential fracturing with multiple fractures. These results highlight fracture propagation mechanisms and demonstrate the robustness of the proposed phase-field model. Full article

Electrohydrodynamic effects can significantly alter transport processes in reacting flows, even when the plasma is weakly ionized. However, predictive modeling of such plasma–flame interactions remains challenging due to the multiscale coupling among charge transport, fluid motion, and chemical kinetics. This study presents a charge-transport closure model to investigate electrohydrodynamic influences on laminar non-premixed flames. A two-dimensional computational framework in cylindrical coordinates is used to simulate plasma-assisted methane–air diffusion flames under weak electric-field conditions representative of practical combustion environments. To represent plasma–flow coupling in a computationally feasible yet physically consistent manner, a charge-transport formulation based on the drift–diffusion approximation is employed. The model solves transport equations for representative positive and negative charge carriers coupled with Poisson’s equation for the electric potential to obtain a self-consistent electric field. This formulation assumes a weakly ionized regime for low-temperature plasma-assisted combustion, in which neutral species dominate the mass and momentum transport, while ionization chemistry is simplified and charge transport primarily influences the flow through electrohydrodynamic body forces and Joule heating. Assuming a weak electric field, the steady flamelet model is applied, in which plasma effects primarily influence scalar transport and local thermal balance rather than inducing significant bulk ionization dynamics. The governing equations are discretized using a high-order compact finite-difference scheme that provides improved resolution of steep gradients in temperature, species concentration, and space-charge density near thin reaction zones. The canonical laminar flame model configuration was validated using the established laminar methane–air diffusion flame benchmark, and steady-state spatial profiles of key transport properties were evaluated. Two-dimensional analysis identified the discharge coupling location as an important factor. The application of discharge in the fuel-air mixing region leads to a clear restructuring of the flame. When the discharge is activated, electrohydrodynamic forcing and ion-driven momentum transfer produce a highly localized, columnar flame with sharp gradients and a confined reaction zone. Compared with the baseline case, the plasma-assisted flame localizes the OH-rich reaction zone, confines the high-temperature region into a narrow column, and enhances downstream H₂O formation. Full article

Hyaluronic acid (HA), a major extracellular matrix component, is used therapeutically to aid healing and deliver drugs to injury sites. Burns create serious clinical and aesthetic problems needing fast skin repair to prevent complications. This study compared 1.8% pharmaceutical-grade HA with panthenol-containing gel (PCG) in deep-burn healing in rats against spontaneous healing. HA slightly accelerated wound closure from day 3 compared to PCG; both induced granulation by day 7 and epithelialization by day 28. HA caused early collagen drop (day 3), later matched PCG levels with abnormal distribution, and both exceeded control by day 28. HA normalized systemic leukocyte counts by day 14 while strongly increasing local leukocyte infiltration in the wound area. HA dual immune effect depends on source and properties; further research is required for clinical use in wound healing. Full article

The multi-cycle high-rate injection and production operations in Underground Gas Storage (UGS) facilities converted from depleted fracture-pore carbonate gas reservoirs induce complex rock–fluid interactions that threaten long-term integrity and performance. This study experimentally investigates the petrophysical responses of the Xiangguosi (XGS) UGS carbonate reservoirs in China using multi-cycle stress sensitivity tests, fines migration experiments, and water evaporation–salt precipitation analyses. SEM observations distinguish the contributions of crack closure and matrix compression to permeability evolution. Results show a sharp contrast in mechanical damage: high-quality rocks present negligible permanent deformation (<8% Young’s modulus reduction), whereas poor-quality rocks suffer catastrophic deterioration (>60%). Fines migration exhibits a three-stage behavior under cyclic flow, with water saturation significantly aggravating permeability impairment. A critical salinity threshold (220,000 ppm) is identified for the transition between drying-enhanced storage and salt plugging. Permeability declines sharply despite a slight porosity increase due to selective salt clogging of key pore throats, revealing a clear porosity–permeability decoupling. Salt deposition under movable water conditions can reduce UGS capacity by up to 1.45%. Reservoir heterogeneity, microfractures, karst structures, and initial petrophysical properties dominate the storage and flow space evolution. This work provides a predictive framework for optimizing injection–production strategies and improving the performance of complex carbonate UGS. Full article

Heat treatment is essential for In625 fabricated by laser powder bed fusion (L-PBF), as it significantly influences microstructural evolution, defect behavior, and mechanical performance. In this study, the effects of different solution heat treatments on L-PBF-fabricated In625 were systematically investigated. Industrial computed tomography was employed to characterize internal defects before and after heat treatment, while optical microscopy, EBSD, TEM, and EDS were used to analyze microstructural evolution. Room-temperature tensile tests evaluated mechanical properties. The results show that heat treatment at 1090 °C reduces porosity from 0.33% to 0.25%, whereas increasing the temperature to 1150 °C results in a further increase in porosity to 0.45%. This non-monotonic behavior is interpreted as the result of competing mechanisms, including partial closure of small pores at 1090 °C and pore coarsening/enlargement at higher temperatures, with the latter possibly involving the growth of sub-resolution pores into the CT-detectable range. Complete grain equiaxiality occurs after heat treatment at 1090 °C or higher, with average grain sizes below 100 μm, although grain coarsening becomes pronounced at higher temperatures. Samples heat-treated at 1150 °C exhibit reduced mechanical anisotropy, achieving tensile strength above 919 MPa and elongation up to 60%. These results clarify the mechanisms by which heat treatment governs microstructure–defect–property relationships in L-PBF In625, guiding its engineering application. Full article

Background and Objectives: The objective of this study is to evaluate whether deferoxamine modulates cell biological properties, such as proliferation and wound closure of porcine corneal endothelial cells (CECs) in vitro, and whether the treatment of CECs with deferoxamine results in an enhanced expression of vascular endothelial growth factor (VEGF). Materials and Methods: Corneal endothelial cells were extracted from porcine globes within 24 h postmortem. Immunohistochemistry for the endothelial Na⁺/K⁺-ATPase was performed to confirm the cells’ endothelial origin. To assess CEC viability and proliferation, a water-soluble tetrazolium salt (WST-1) and 5-bromo-2′-deoxyuridine (BrdU) assay were performed. Corneal endothelial wound closure was evaluated using a wound closure assay. VEGF mRNA expression was evaluated using real-time polymerase chain reaction (rt-PCR). Results: The extracted corneal endothelial cells showed a typical hexagonal morphology with Na⁺/K⁺-ATPase staining of the cell membrane. The treatment with 200 µM deferoxamine significantly increased CEC viability to 121 ± 24% compared to the control group (p = 0.0024). Corneal endothelial cell proliferation did not show any significant changes under the treatment with deferoxamine (p > 0.05). Both 100 µM and 200 µM deferoxamine led to a significantly smaller remaining wound area of 82.4 ± 6.7% and 78.7 ± 6.2% (p < 0.0001) in comparison to the control group after 24 h of treatment in the wound closure assay. Treatment with 200 µM deferoxamine significantly induced VEGF mRNA expression to 1.67- ± 0.57-fold from 1.00- ± 0.03-fold in the control group (p = 0.0006). Conclusions: Deferoxamine effectively enhances corneal endothelial cell viability and wound healing associated with an overexpression of VEGF. Thus, deferoxamine is a potent modulator of cell biological properties of corneal endothelial cells and maintains their integrity in vitro. Full article

Wound healing research has advanced through nanotechnology-based delivery systems that enhance the stability and therapeutic potential of bioactive compounds. Resveratrol, a natural polyphenol with antioxidant and anti-inflammatory properties, shows promise for wound healing but is limited by poor bioavailability. This study investigates the efficacy of nano-liposome-encapsulated resveratrol in enhancing skin wound repair in adult zebrafish (Danio rerio). Using a laser-based ablation method, precise full-thickness skin wounds were induced and monitored over 50 days. Resveratrol-loaded liposomes were prepared and orally administered via gavage to facilitate systemic exposure. Compared to the control and blank liposome groups, resveratrol liposome treatment significantly accelerated wound closure, achieving earlier healing milestones (25%, 50%, and 75%). The zebrafish model provided a regenerative platform for real-time evaluation of nanomedicine-based therapies. This study demonstrates the wound healing effects of resveratrol and liposomal encapsulation, offering a targeted, systemically administered strategy for advanced systemic healing and highlighting zebrafish as a valuable model for preclinical regenerative medicine research. Full article

In this study, a hydrogel was developed based on a chondroitin sulfate–iron complex (CSFe) incorporated into a sodium alginate matrix. The CSFe complex was first prepared through the interaction of chondroitin sulfate (CS) with Fe³⁺ ions, achieving an iron content of 2.06%. Structural characterization confirmed that Fe³⁺ coordinated with the carboxyl, sulfate, and N-acetyl groups of CS, resulting in increased molecular weight and altered physicochemical properties. The CSFe complex exhibited significant antibacterial activity against Escherichia coli and Staphylococcus aureus (S. aureus), and was further incorporated into a sodium alginate matrix to form an injectable hydrogel with favorable physicochemical properties such as spreadability, shear-thinning behavior, and a compact porous microstructure. In a mouse model of S. aureus-infected wounds, the CSFe hydrogel significantly accelerated wound closure, reduced the levels of pro-inflammatory cytokines (TNF-α and IL-6), and increased the anti-inflammatory cytokine IL-10, indicating potent anti-infective and immunomodulatory functions. Overall, this work presents a multifunctional CSFe-incorporated hydrogel system that integrates antibacterial, anti-inflammatory, and tissue-regenerative properties, offering a promising strategy for infected wound healing and highlighting the potential of trivalent iron–polysaccharide coordination complexes in the development of advanced biomedical materials. Full article

This study presents the design, thermodynamic modelling, and numerical optimisation of a medium-scale (100 kW) transcritical CO₂ air-source heat pump water heater (ASHP-WH) intended to deliver 90 °C domestic hot water under sub-zero ambient conditions. A detailed component-sizing methodology was established and implemented in AMESim 2404 using REFPROP-based property calculations, with model convergence confirmed by the mass and energy balance closure. Parametric investigations covering the discharge pressure, refrigerant charge, ambient air temperature, and water outlet temperature were conducted through 140 steady-state simulations. The results show that the system achieved a heating capacity of 100–121 kW with a coefficient of performance (COP) of 2.7–3.3 across −15 °C to +10 °C ambient conditions. The optimal discharge pressure (≈11.2 MPa) and charge inventory (10 ± 2 kg) define a broad operating window that ensures COP stability (±2%) and avoids liquid carry-over. The exergetic efficiency remained above 0.75 throughout the tested climate range. Compared with published laboratory prototypes, the proposed 100 kW module demonstrates a superior performance at harsher sub-zero boundaries, highlighting its potential for commercial hot water and industrial applications. The findings provide actionable guidelines for component sizing, charge management, and adaptive pressure control, and establish a pathway from a numerical prototype to scalable field deployment of medium-scale transcritical CO₂ systems. Full article

Background/Objectives: Diabetic wound healing faces significant challenges due to the harsh microenvironment of wounds such as high blood glucose levels, excessive inflammation, persistent infection, upregulated reactive oxygen species (ROS), and damaged new blood vessels. Therefore, developing hydrogel dressings with microenvironmental regulation functions has become an important strategy in treating diabetic wounds. Methods: In this study, an ultraviolet in situ crosslinked hydrogel (D@H/E) was developed using methacrylic anhydride modified hyaluronic acid (HA-MA) and glycidyl methacrylate modified ε-polylysine (EPL-GMA), loaded with the iron chelating agent desferrioxamine (DFO). The physicochemical and biochemical properties of the hydrogel were comprehensively characterized, and its efficacy as a dressing for diabetic wounds was evaluated in a STZ-induced hyperglycemic mouse model. Results: This hydrogel demonstrated remarkable multidimensional effects by alleviating oxidative stress damage, inhibiting bacterial infection, regulating inflammatory responses, mitigating ferroptosis, and promoting cell migration and tubule formation. Specifically, the DFO-loaded hydrogel achieved a high DPPH radical scavenging efficiency of 80.8% and exhibited excellent antibacterial activity, with over 99.8% inhibition against both S. aureus and E. coli. In streptozotocin (STZ)-induced diabetic mice, the hydrogel accelerated wound closure to near completion by day 14. Mechanistically, it significantly upregulated CD206 expression to promote M2 macrophage polarization, upregulated the expression of angiogenesis-related factors to promote angiogenesis at the wound site, and enhanced GPX4 expression to alleviate ferroptosis. Conclusions: By orchestrating multi-dimensional synergy that combines ROS scavenging, infection control, immune regulation, and anti-ferroptosis, this D@H/E hydrogel system effectively remodels the harsh diabetic wound microenvironment, offering a promising platform for chronic wound management. Full article

Impaired wound healing is a major cause of morbidity among patients with diabetes. Human α1-antitrypsin (hAAT) promotes the resolution of injured tissues. In hyperglycemic conditions, circulating hAAT is likely to undergo glycation, yet it is unknown whether its reparative properties are preserved. We hypothesized that clinical-grade hAAT treatment, but not deliberately glycated hAAT (gly-hAAT), would promote wound repair under hyperglycemic conditions. Mice were rendered hyperglycemic, excisional wounding was performed, and wounds were treated with topical albumin or hAAT every three days. The wound area was assessed, and samples were collected for histology and gene expression analysis. Gly-hAAT was generated from clinical-grade hAAT, after which in vitro RAW 264.7 macrophage responses and re-epithelialization of A549 cells were assessed. Gap closure was further assessed using sera from a human cohort (prospective samples from 10 patients with poorly controlled diabetes at Soroka University Medical Center, Beer-Sheva, Israel, 2018). Group comparisons were performed using one-way ANOVA with Tukey’s post hoc test. hAAT accelerated in vivo wound closure and in vitro A549 cell gap closure, accompanied by an anti-inflammatory IL-1Ra/IL-1β gene expression profile. In contrast, gly-hAAT inhibited normoglycemic mouse wound closure, evoked an inflammatory response in macrophages, and interfered with A549 cell gap closure; concomitant hAAT treatment improved gap closure. Similarly, patient serum inhibited A549 gap closure, and concomitant hAAT treatment improved gap closure. Importantly, inferential statistical analysis was not performed on this outcome due to the small and heterogeneous human cohort. In conclusion, hAAT accelerated wound closure in hyperglycemic mice and in A549 cells, whereas gly-hAAT promoted inflammatory responses and impaired wound closure, a trend reversed by native hAAT. These findings support the concept that glycation undermines the beneficial functions of circulating hAAT and provides a mechanistic insight into the pathophysiology of diabetic wound healing. Further studies are warranted to evaluate clinical-grade hAAT as a potential therapeutic for hyperglycemia-associated impaired wound healing. Full article

Binder Jetting 3D Printing (BJ3DP) offers an effective pathway for the rapid fabrication of complex high-entropy alloy (HEA) components. In this study, the macroscopic characteristics, microstructural evolution and mechanical properties of Al_0.5Cr_0.9FeNi_2.5V_0.2 HEA green parts prepared via BJ3DP were investigated under various sintering conditions. Results showed that the relative density of the sintered parts increased significantly with temperature, transitioning from a low density (<90%) at 1300–1330 °C to near-fully dense (~98%) at 1340–1350 °C. Consequently, the mechanical properties were remarkably improved. The yield strength (σ_0.2) increased from 300 MPa to 710 MPa (a 136% increase), and the ultimate tensile strength (σ_b) rose from 310 MPa to 780 MPa (a 148% increase) as sintering temperature rose from 1300 °C to 1350 °C. Microstructural analysis revealed that at lower sintering temperatures, the alloy exhibited high porosity and a non-coherent structure composed of an FCC matrix and Cr-rich BCC phase, with Al/Ni intermetallic compounds distributed around pores. Conversely, at the final sintering stage, pore closure was achieved, and a coherent structure consisting of an FCC matrix and scale-like L1₂ precipitates was formed. Optimal mechanical properties (tensile strength ≥ 700 MPa) were achieved when sintering at 1340 °C, primarily attributed to densification and precipitation strengthening. Full article

Long-term safety assessment of deep geological repositories for spent nuclear fuel requires explicit evaluation of thermo-mechanical (TM) processes induced by decay heat and their influence on fractured host rock. A safety-relevant, though low-probability, scenario concerns shear reactivation of fractures intersecting deposition holes, which could compromise canister integrity if displacement exceeds design limits. This study presents a three-dimensional discrete element modelling approach to analyze the thermal evolution of the Forsmark repository (Sweden) and the associated long-term response of a discrete fracture network (DFN) during the post-closure phase. The model explicitly represents repository panel, deterministic deformation zones, and a stochastically generated fracture network embedded in a bonded particle assembly representing the rock for Particle Flow Code (PFC) numerical simulations. Time-dependent heat release from spent nuclear fuel canisters is implemented using a physically based decay power function. A deposition panel-scale heat-loading formulation accounts for deposition-hole and tunnel spacing. Two emplacement scenarios are analyzed: (a) a simultaneous all-panel heating scenario, used as a conservative bounding case, and (b) a sequential panel heating scenario representing staged emplacement and closure. The simulations show that temperature and thermally induced stress evolution are sensitive to the emplacement and closure sequence. Sequential heating produces a more gradual thermal build-up and lower peak temperatures than simultaneous heating, indicating that thermal and stress perturbations in the host rock can be influenced not only through repository design, but also by operational strategy. Thermally induced fracture shear displacement displays a systematic temporal response. Fractures located within the deposition panel footprint develop shear displacement rapidly during the early post-closure period, reaching peak values at approximately 200 years, followed by gradual relaxation as temperatures decline. The average peak shear displacement on fractures is on the order of 2–3 mm, while fractures outside the panel footprint show smaller early-time displacements and a more prolonged long-term response. All simulated shear displacements remain more than one order of magnitude below the commonly cited canister damage threshold for Forsmark of approximately 50 mm, even for the conservative simultaneous heating case. These results indicate that thermally induced fracture shear is unlikely to cause direct mechanical damage to canisters. At the same time, the persistence of residual shear displacement after heating implies permanent fracture dilation, which may influence long-term hydraulic properties and indirectly affect processes such as groundwater flow and canister corrosion. The modelling framework and results presented here were conducted for review purposes independently from the Swedish safety case, and provide a mechanistic basis for evaluating thermally induced fracture deformation in crystalline rock repositories and contribute to bounding the role of thermo-mechanical processes in the safety assessment of spent nuclear fuel disposal at Forsmark. Full article