Search Results (3,673)

Airfoil fin Printed Circuit Heat Exchangers (PCHEs) offer significant advantages in reducing flow resistance, promoting turbulence, and enhancing heat transfer performance due to their discrete fin configuration. However, compared with conventional continuous-channel structures, the geometric discontinuities and sharp trailing edges introduced by discrete fins tend to induce severe stress concentration at the fin roots, resulting in a more complex structural response. In this study, a PCHE core with NACA0020 airfoil fins is investigated. Finite element analysis combined with a sequential one-way thermo-structural coupling approach is conducted to characterize the fins’ stress and deformation behavior under high temperature and pressure. The plate region is evaluated based on the linear elastic stress criteria specified in ASME Boiler and Pressure Vessel Code Section III, while localized yielding regions such as the fin roots are assessed using an equivalent plastic strain indicator. Results indicate that the structural response of the PCHE core is dominated by pressure loading under the investigated operating conditions with ΔT = 18 °C and ΔP = 12.05 MPa, whereas thermal stress caused by constrained thermal expansion mainly modifies local stress distributions and has a limited effect on global deformation. Owing to the discontinuous support provided by discrete airfoil fins, the fin roots act as the primary load-transfer path and sustain higher stress levels. The maximum von Mises stress is observed at the trailing edge of the fin root on the high-pressure side, while the largest deformation occurs in the unsupported plate region and is governed by bending. Parametric analysis indicates that, within the investigated parameter range, a fully staggered fin arrangement promotes more uniform load distribution and exhibits the most favorable structural response. In contrast, increasing the fin chord length and relative thickness reduces the overall load-carrying capacity of the core. Finally, a power-law predictive correlation for the maximum total plate deformation was developed, showing that the parameter influence on plate structural response follows the order horizontal pitch (L_h) > vertical pitch (L_v) > channel etching depth (L_e) > staggered pitch (L_s). In contrast, normalized sensitivity analysis of the maximum fin-root von Mises stress shows the order staggered pitch (L_s) > horizontal pitch (L_h) > vertical pitch (L_v) > channel etching depth (L_e), indicating that global plate deformation and local fin-root response are governed by different structural mechanisms. Full article

Highway slopes susceptible to landslides are typically reinforced by vegetation cover and the application of concrete frame beams, but vegetation cover may degrade the accuracy of InSAR deformation monitoring. We installed artificial corner reflectors (CRs) on the frame beams and assessed the stability of the vegetated slope using finite element simulation constrained by InSAR deformation data. A study was conducted on a typical landslide-risk slope within the K87 + 391.5–K87 + 565 section of the Guihuang highway, which is reinforced with cast-in-place and prefabricated concrete beams. Experimental results demonstrate that two adjacent corner reflectors (CRs) on the two types of frame beams of the slope can be successfully identified, with deformation rates ranging from 0.1 to 0.4 mm/y, and the root mean square error (RMSE) of discrepancies between CR-InSAR measurements and slope displacement monitoring sensors is less than 0.3 mm. Meanwhile, the current strength reduction factor values for slopes reinforced with cast-in-place and prefabricated concrete beams, as constrained by InSAR multi-dimensional deformation, are 0.11 and 0.12, respectively which are much lower than the critical strength reduction factors of 1.28 and 1.22 corresponding to full coalescence of plastic strain from the slope toe to the slope crest, which indicates that the cast-in-place and prefabricated frame beams exhibit comparable support performance. Full article

In punch-bending of thin stainless steel components, the final product angle is significantly influenced by springback after process completion. In the present study, an attempt has been made to investigate the effect of wire straightening strategies and bending tool parameters on the springback behavior of cold-rolled EN 1.4310 flat wire (3.9 mm × 0.4 mm). The wire, supplied in coiled form with inherent residual stresses, was subjected to single-pass, two-pass, and four-pass three-roller straightening prior to bending. Tensile characterization was performed to examine changes in elastic-plastic flow stress behavior, and the experimentally obtained true stress–true plastic strain data were directly implemented in finite element simulations. A full factorial parametric study was conducted by varying the bending angle (66–90°), bending radius (1.33 mm–2.93 mm), and die-punch clearance conditions. Experimental investigations on a subset process parameters were performed to assess the simulation outcomes. It was observed that the straightening history modifies the springback magnitude. Among the parameters considered, the bending radius was found to be the dominant factor governing springback sensitivity. An increase in the clearance gap between the die and punch produces systematic and monotonic shifts in the final product angle due to an increase in the effective bending radius. Full article

Corrosion of reinforcing steel is a key cause of deterioration in reinforced concrete (RC) structures exposed to coastal environments with chloride presence. The loss of reinforcing steel cross-sectional area, cracking of the concrete cover, and reduction in confinement progressively decrease both strength and ductility of structural elements. This study provides a reproducible, open-access dataset, compiling input parameters and numerical results of the cyclic behaviour of isolated RC columns and RC frames, specifically addressing their nonlinear cyclic response under moderate corrosion (η < 25%), as well as in the non-corroded (baseline) conditions, generated through conventional nonlinear modelling. In terms of modelling, the methodology applies fibre-section modelling for columns and concentrated plastic hinges for beams. Furthermore, the corrosion effects are incorporated by reducing the steel area and ultimate strain, while also accounting for the decrease in compressive strength of the cracked concrete cover. Therefore, the cyclic response is represented by a Pivot-type hysteretic model. It is worth noting that the dataset provides model input information, such as material stress–strain relationships and backbone curves reflecting corrosion-induced deterioration. It also includes structural outputs, such as force–displacement relationships, and envelopes of quasi-static hysteretic cycles for the analyzed columns and frames. Overall, the dataset facilitates the calibration and validation of numerical models for RC structures affected by corrosion. In conclusion, the contribution enhances the reliability of computational simulations and supports the development of predictive tools for structural performance under degradation scenarios. Full article

Cellulose ether, like hypromellose (HM), is an extremely versatile material that is widely used in pharmaceutical products as film coatings. To modify the surface properties of HM films, additives are routinely included during the film formulation process, which are typically hydrophobic lubricants or hydrophilic plasticizers. Plasticizers increase the flexibility and reduce the brittleness of the film. The first goal of this study is to demonstrate that plasticization of HM films by low-molecular-weight (400 g∙mol⁻¹) polyethylene glycol (PEG) allows tuning adhesion and friction properties of HM films, both at nano- and macroscales. Surface morphology, surface energy, nano/macro adhesion, and nano/macro friction coefficient were studied by atomic force microscopy (AFM) in adhesion or friction modes at the nanoscale, wettability, and probe-tack adhesion, as well as pin-on-disk friction experiments at the macroscale. The results show that the addition of PEG decreases the Young’s modulus and the Tg of HM-plasticized films while increasing their strain at break and surface energy. The macroadhesion force increases from 9 to 90 mN by the addition of 40% w/w of PEG, whereas the macrofriction coefficient is reduced by 50%. The hypothesis of insertion of plasticizer molecules in HM chains’ nano-domains is evidenced and explains these results. The second goal of this study is to investigate nanoscale versus macroscale correlation of adhesion and friction properties and the role of adhesion in friction experiments. The results show, first, that the evolution of the adhesion energy at the macroscale as a function of adhesion energy at the nanoscale is linear. On the contrary, a high friction coefficient at the nanoscale corresponds to a low friction coefficient at the macroscale and vice versa, showing a first linear decrease for PEG contents ranging from 0 to 30% (w/w) and the second linear decrease, less pronounced, is observed for PEG contents ranging from 30 to 40% (w/w). The hypothesis of a difference in contact pressure applied on the probe at both scales, as well as HM-PEG surface phase separation at a high PEG content (>30% w/w), is proposed to explain this difference. The variations in friction coefficients are linear according to the PEG plasticizer content and suggest its lubricant role in HM-Plasticized films. Finally, the interplay between adhesion and friction, in friction experiments, is evidenced and appears dominant at the nanoscale. Full article

Lysobacter antibioticus Hz25 is a novel strain that was isolated from the rhizosphere of the relict endemic plant Hedysarum zundukii Peschkova (Fabaceae), which grows on carbonate soils in the Baikal region of Russia. This work presents the complete genome sequence of Hz25 (5.98 Mb, 66.94% GC), which was obtained using a hybrid assembly method combining Oxford Nanopore and Illumina sequencing. Phylogenetic analysis based on 47 Lysobacter genomes and an average nucleotide identity (ANI) value of 96% confirmed its affiliation with L. antibioticus. A comparative pan-genome analysis with three closely related strains (13-6, 76, and ATCC 29479) identified 554 strain-specific genes. This significant genomic plasticity likely reflects adaptation to the sharply continental climate, high insolation, and low free iron content of the native soil. The genome encodes a comprehensive micropredator arsenal, including: seven chitinase genes (GH18 and GH19 families); bacteriolytic enzymes (Blp, L1, L4, Ami); a complete type III secretion system (T3SS) with predicted effectors; type IV pili (including the PilZ-PilB regulatory complex); and siderophore biosynthesis genes (lysochelin). The genome contains genes ars of an arsenic resistance system, but lacks the ACR3 efflux pump, suggesting that these genes may have alternative functions. Genes involved in calcium homeostasis (Excalibur domain, Na⁺/Ca²⁺ antiporter) were also identified. These features make Hz25 a promising candidate for biocontrol applications in cold climates and metal-contaminated environments. Full article

Helicobacter pylori (H. pylori) is a highly adaptable gastric pathogen with marked genomic plasticity. Whilst functional CRISPR-Cas systems provide adaptive immunity in many bacteria, they have not been identified in H. pylori, unlike CRISPR-like sequences. In this study, eight H. pylori genomes were analysed using the bioinformatics tools CRISPRCasFinder, CRISPRCasTyper, and CRISPRloci. A total of 25 CRISPR-like arrays were identified, showing high conservation (88%) both between and within strains, suggesting that these arrays are not random remnants but rather organised structures possibly involved in cellular processes. Notably, a structural association was observed between the CRISPR-like sequences and the cag pathogenicity island (CagA-PAI). Conversely, CagA-PAI instability in specific strains was observed in the presence of the TnpA and TnpB transposons. Furthermore, in strain 29CaP, CRISPR-like assemblies were located in genomic proximity to the prophage Helico 1961P, leading to the hypothesis of a compensatory or regulatory effect in the absence of CagA-PAI. Taken together, these findings indicate that CRISPR-like arrays in H. pylori characterise a genomic architecture within regions of high plasticity. This study provides a solid exploratory foundation for future functional research on the adaptive and pathogenic evolution of H. pylori. Full article

The Zircaloy-4 alloy is a key structural material for nuclear reactor cores. However, its behavior under warm deformation conditions and during phase transformations requires in-depth investigation to improve technologies for producing ultrafine-grained (UFG) structures using severe plastic deformation methods. This work presents a comprehensive study of the rheological properties, phase stability, and microstructural evolution of the alloy in the temperature range from 20 to 950 °C at strain rates of 0.5 and 15 s⁻¹. The experimental part included plastometric testing, dilatometric analysis, and microstructural characterization. It was established that the optimal window for plastic deformation corresponds to warm deformation at 650 °C. Dilatometric analysis confirmed that heating to 650 °C ensures the preservation of a stable initial α-phase structure, since the formation of secondary phases and the α→β transformation are initiated at higher temperatures, namely 694 °C (onset) and 847 °C (completion). At 650 °C, the deformation resistance decreases by approximately 70% compared to cold processing, while the strain-rate sensitivity of the flow stress is minimized. EBSD analysis showed that deformation under these conditions leads to intensive grain fragmentation via mechanisms of dynamic recovery and the initial stages of continuous dynamic recrystallization. The decisive role of the kinetic factor was demonstrated: reducing the strain rate to 0.5 s⁻¹ promotes the formation of a finer and more homogeneous grain structure. In contrast, high strain-rate deformation (15 s⁻¹) results in coarser grains and increased non-relaxed intragranular residual stresses. The obtained results provide a physical basis for optimizing thermomechanical processing regimes and can be used to produce UFG structures in zirconium alloys without the risk of phase degradation. Full article

Polypropylene (PP) biocomposites reinforced with Cornus sanguinea L. (CS) pruning-waste particles were investigated using a combined experimental mechanics and finite element (FE) validation framework to support model-based design with an under-utilized lignocellulosic feedstock. Two particle-size fractions (<100 µm, LF1; 100–250 µm, LF2) were produced by grinding and sieving and incorporated into PP at 5–20 wt% via melt compounding and compression molding. Tensile and three-point bending properties were measured in accordance with ASTM D638 and ASTM D790. PP exhibited a tensile strength of 23.63 ± 0.51 MPa and a tensile modulus of 868 ± 21 MPa. Incorporation of LF1 particles increased tensile modulus monotonically, reaching 1020 ± 137 MPa at 20 wt%, while tensile strength decreased with filler content; by contrast, the 20 wt% LF2 formulation showed a pronounced strength reduction to 16.30 ± 0.25 MPa, indicating a disadvantageous size–loading interaction. In flexure, strength was comparatively insensitive to reinforcement (PP: 39.5 ± 0.34 MPa; reductions typically ≤7%), whereas flexural modulus increased to 2152 ± 27 MPa (LF1) and 2110 ± 34 MPa (LF2). FE models calibrated using true stress–true plastic strain data accurately reproduced tensile responses across the full strain range and flexural behavior within the pre-contact-dominated regime, demonstrating the suitability of PP/CS biocomposites for stiffness-driven applications. Full article

The remarkable ecological success of fungi is supported by their capacity for rapid and often reversible molecular responses to fluctuating environments. While conventional evolutionary theory has largely emphasized mutation and selection as central drivers of adaptation, many environmentally responsive fungal traits are also shaped by molecular processes that generate reversible phenotypic variation on ecological or developmental timescales. This review synthesizes current knowledge on reversible genetic and epigenetic mechanisms underlying fungal phenotypic plasticity by integrating insights from programmed genetic rearrangements such as mating-type switching, transposable element activity, variation in tandem repeats and the behavior of accessory chromosomes, together with dynamic epigenetic processes including histone modifications, DNA methylation, chromatin remodeling and RNA mediated regulation. Together, these mechanisms form an interconnected framework that enables rapid and, in many cases, reversible phenotypic diversification, although their consequences range from transient regulatory shifts to partially or fully irreversible sequence-level changes. We highlight the molecular machinery that governs reversibility and its evolutionary implications for fungal pathogenesis, symbiosis, and biotechnology. By uniting genetic and epigenetic perspectives, this review advances a holistic framework in which reversibility is treated as a key property of fungal phenotypic plasticity, helping fungi balance stability with flexibility under environmental challenge. Understanding these mechanisms provides new insights into fungal evolution, and opens new avenues for antifungal intervention and the rational design of industrially valuable fungal strains. Full article

Microplastics (MPs), defined as plastic particles ranging in size from 0.1 μm to 5 mm, have gained significant scientific attention worldwide due to their widespread occurrence and potential risks for human health and the environment. MPs can accumulate in water and soil, affecting organisms across multiple trophic levels and negatively impacting agricultural productivity and animal husbandry. Agricultural practices, such as plastic mulching, compost, and sewage sludge application, contribute to environmental plastic contamination, while irrigation and wastewater reuse facilitate their transport and deposition across ecosystems. Given the limited efficiency and high costs of physicochemical remediation methods, microbial biodegradation has attracted growing attention as a potentially sustainable strategy. This review focuses primarily on the metabolic potential of bacteria and fungi and the mechanisms underlying MP degradation. In the context of environmental safety, such studies are of particular importance. Under optimal laboratory conditions, reported microbial degradation efficiencies varied with microplastic type, microbial strain(s), and experimental conditions, ranging from 4% to >97%. Moreover, the literature review identifies key barriers to practical application, including environmental variability and the limited transferability of laboratory findings to field settings. Future research should therefore prioritize testable, application-oriented approaches. Addressing these gaps is essential to developing effective microbial degradation strategies for mitigating microplastic pollution. Full article

To further improve the mechanical properties of shotcrete in coal mine roadways, end-hooked steel fibers and chopped basalt fibers were selected. Based on the optimal mix ratios identified in existing research, steel–basalt hybrid fiber shotcrete (SBFC) specimens were prepared. Dynamic impact tests under different impact loads and various hybrid fiber contents were conducted using an SHPB. The microstructure was characterized using SEM and XRD. The results show that the dynamic compressive stress–strain curve of steel–basalt hybrid fiber shotcrete can be classified as elastic deformation stage, plastic yield stage, and post-peak failure stage. The incorporation of hybrid fibers reduces the elastic deformation and plastic yield stage, and the post-peak failure stage under active confining pressure shows elastic aftereffect characteristics. The dynamic compressive strength, dynamic elastic modulus, and deformation modulus increase with the increase in impact pressure and fiber content. When there is no confining pressure, the maximum dynamic compressive strength, dynamic elastic modulus, and modulus of deformation of SBFC4 reached 53.1 ± 2.2 MPa, 4.51 ± 0.3 GPa, and 2.55 ± 0.1 GPa, respectively, representing increases of 37.20%, 264.01%, and 59.37% compared with the control group. The dynamic compressive strength increases with the average strain rate, demonstrating a favorable strain rate effect. The energy–time history curves can be roughly divided into initial, growth, and stable stages. Under the same impact load conditions, as the fiber content gradually increases, the incident energy, dissipated energy, and energy utilization rate of the specimens all show a gradual upward trend. SEM and XRD results show that steel fibers and basalt fibers maintain good bonding with the cement matrix, contribute to the formation of gel and crystalline products within the specimens, effectively delay the initiation and propagation of cracks, and thereby improve the mechanical properties of the concrete specimens. Full article

Ductility dip cracking (DDC) remains a persistent challenge in multipass welds of high-chromium nickel-based alloys used in the nuclear power generation industry. While dynamic recrystallization (DRX) has been observed to arrest DDC crack growth and has been associated with weld regions that experience less DDC, there exists no quantitative relationship between the extent of recrystallization in a microstructure and DDC susceptibility. This research examines the influence of intragranular carbides on DRX behavior and establishes an experimental relationship between DDC susceptibility and extent of recrystallization in high-chromium nickel-based weld metals, novel contributions for this alloy system. In this work, the DRX behavior of the weld metal of high-chromium nickel-based filler metals (FM-52, FM-52M, FM-52i, and FM-52xl) was investigated under controlled thermo-mechanical conditions, and its effect on DDC susceptibility was established. Weld metal specimens were subjected to uniaxial deformation at 1100 °C to a true strain of 2% at strain rates of 10⁻³/s and 10⁻⁴/s using a Gleeble 3800^TM. Recrystallization was quantified using electron backscatter diffraction (EBSD) via grain orientation spread (GOS) analysis and dislocation–precipitate interactions were examined using transmission electron microscopy (TEM). Strain-to-fracture (STF) testing at 950 °C was employed to assess DDC susceptibility as a function of the extent of recrystallization and grain surface area. All tested weld metals exhibited increased recrystallization and grain refinement, as the strain rate decreased from 10⁻³/s to 10⁻⁴ s. The FM-52i weld metal specimens exhibited the highest grain refinement under high temperature deformation, followed by the FM-52xl, FM-52, and FM-52M weld metals with a percent reduction in average grain surface area of 51.22%, 41.66%, 35.48%, and 24.40%, respectively. The FM-52i weld metal specimens also exhibited the highest recrystallization response, followed by FM-52M, FM-52xl, and FM-52 weld metals at 75%, 40%, 39% and 21% recrystallized, respectively. Weld metals containing strong carbide formers experienced higher recrystallization responses than those without due to precipitate–carbide interactions. All tested weld metals experienced drastic reductions in DDC response with increasing extent of recrystallization and decreasing average grain surface areas. DRX in STF specimens was observed to facilitate uniform plastic strain accumulation, lowering overall DDC susceptibility compared to non-recrystallized specimens. Full article

The genus Siccibacter consists primarily of environmental bacteria, with strains of Siccibacter colletis previously isolated only from plant materials and related environments. This study aims to characterize the first clinical isolate of S. colletis and explore its genomic evolution and clinical relevance. Strain S25242 was isolated from the urine of a 64-year-old male with a severe urinary tract infection. The genome of S25242 is 4.19 Mb, containing 4012 coding sequences, 73 tRNAs, 10 rRNAs, and 38 snRNAs. Phylogenetic and phylogenomic analyses indicated that strain S25242 is closely related to S. colletis type strain 1383^T. The strain shared >70% of digital DNA-DNA hybridization (dDDH) values and >96% of average nucleotide identity (ANI) values with the type strain of S. colletis 1383^T, thereby confirming its taxonomic status. The isolate was susceptible to all 11 tested antimicrobials. Comparative genomics identified 1942 S. colletis-specific genes (including multidrug efflux systems) and 13 unique genes in S25242 related to transposition and DNA integration. This study reports the first clinical isolate of S. colletis, providing evidence that genomic plasticity facilitates its transition from an environmental inhabitant to an opportunistic pathogen. The findings highlight the need for enhanced clinical surveillance of the Siccibacter genus and offer insights into its genomic evolution and clinical adaptation. Full article

TC4DT (ELI) is a damage-tolerant titanium alloy characterized by high fracture toughness and slow crack propagation rates, and is, therefore, considered one of the standard materials for model fasteners in modern equipment. However, its high yield strength leads to excessive tool wear and forming defects. This paper presents a complete FE simulation framework to investigate the thread-rolling process of TC4DT(ELI) bolts M16 × 1.5. Using the actual geometries of the workpiece and rollers, an elasto-plastic three-dimensional finite element model was built in ABAQUS/Explicit to perform verification simulations, with the theoretical blank diameter and forming force as the reference benchmarks. The simulation results agreed well with the actual industrial data. This study carried out single-factor analyses of the effect of three important process parameters—the roll speed, friction coefficient, and initial temperature—on the resulting stress–strain distribution, forming force, and thread formation depth. A modal analysis was performed in ANSYS Workbench to check the structural integrity and avoid resonance while operating. According to the results, the optimized parameters decreased the maximum forming force by 14.8% and improved thread filling. Compared with experimental data, the simulation error in the blank diameter was controlled within 1.2%. The present work, a reliable numerical underpinning for replacing expensive and time-consuming trial-and-error processes, forms a basis for high-performance titanium alloy fasteners and assists in the wider application of such fasteners in modern equipment and any advanced manufacturing industries. Full article