Search Results (3,350)

A study was conducted on the interaction of surface gravity waves with a relatively thin, free-floating ice floe compared to the height of the waves. Physical and numerical modeling, as well as analytical research, were used. An overview of scientific works on the research topic is presented. The physical model consisted of an experimental setup (wave flume) with a wooden plate exposed to gravitational harmonic waves of different lengths and periods. The numerical model is based on calculations performed in the LS-DYNA program, where the fluid was simulated using the Euler–Lagrange method, and solid bodies were considered rigid. Analytical studies use the theory of interaction of small-amplitude waves with floating breakwaters. It is shown that as the wave height increases for conditions of interaction between waves and ice floes of almost identical horizontal dimensions, one end of the floating body sinks into the water, which leads to a significant reduction in the drift speed of the ice floe. Formulas have been obtained that express the ratio of the ice floe’s speed to the wave velocity, as well as the ratio of the height of the incident waves to the height of the transmitted waves, depending on the ratio of the wavelength to the horizontal dimensions of the floating ice floe. Full article

Background: Over the past 25 years, advances in knee surgery have been driven by an improved understanding of fracture morphology and associated injuries, as well as by significant technological progress. The introduction of novel classification systems has led to the refinement of treatment strategies, particularly with respect to the selection of surgical approaches. Furthermore, advances in biomechanical understanding have facilitated the development of new osteosyntheses designed to promote earlier rehabilitation while simultaneously reducing complication rates. Research Question: Which key milestones over the last 25 years have significantly influenced treatment strategies for knee joint fractures, with a perspective on unresolved issues? Results: Recent advances in fracture management, osteosynthesis, imaging techniques, and biomechanical research have substantially improved clinical outcomes, including a reduction in infection rates and improved postoperative results. The implementation of new classification systems has enabled more precise preoperative planning, allowing surgeons to define approaches that ensure adequate visualization of the articular surface while facilitating optimal positioning of the osteosynthesis. In terms of osteosynthesis, the introduction of locking plate technology has become widely established and supported by biomechanical evidence and has largely replaced traditional methods such as tension-band wiring of the patella. Despite these advances, fracture management in geriatric patients remains a considerable challenge, as compromised bone quality frequently limits the ability to achieve sufficiently load-stable osteosynthesis. Direct visualization of the articular surface is essential for adequate assessment and reduction of the affected articular segment. However, there is currently no consensus on which surgical approach or possible extension is most appropriate while simultaneously ensuring a low complication rate. Full article

Self-oscillators convert constant external stimuli into sustained mechanical work, offering potential for applications such as soft robotics, energy absorption, and mechanical logic. However, the effective design of a light-driven self-oscillation system is challenging due to geometrically constrained deformation modes and the inherent rigidity of rectilinear light propagation paths. Notably, the mirror-reflected optical feedback loop decouples the feedback mechanism from geometric constraints imposed by deformation modes, enabling dynamic coupling independent of structural geometry. In this study, we introduce a geometry-flexible light feedback loop to drive a liquid crystal elastomer (LCE) self-oscillator. The system comprises an optically responsive LCE fiber, a spring, a mirror, and a perforated plate. By integrating the dynamic photon propagation path in light feedback routing with the dynamic deformation model of the LCE, we develop a dynamic theoretical model of the oscillator under constant illumination. Numerical simulations reveal two distinct patterns: static equilibrium and self-oscillation. Self-oscillation is generated by the light-induced contraction of LCE fiber segments illuminated by reflected light. Crucially, mirror-reflected light enables localized deformations anywhere along the fiber to contribute to global displacement feedback, thereby transcending the constraints of geometric deformation modes. This capability transcends the limitations posed by constrained geometric deformation modes, enabling adaptable control of the optical feedback loop through simple geometric alterations. This innovative approach circumvents the need for intricate structural feedback designs and separate energy harvesters, as well as actuator systems. Full article

Axial compression tests were conducted on four groups of C-shaped steel tube-confined concrete specimens. The results demonstrate that the C-shaped steel tube effectively confines the core concrete, significantly enhancing the peak compressive stress by 14.1% to 22.1% compared to unconfined concrete, resulting in a more gradual descending branch of the stress–strain curve, and effectively improving the ultimate deformation capacity of the concrete with peak strain increasing by a factor of 1.45 to 1.68. The influences of steel plate thickness and reinforcement on the compressive stress–strain curve of the confined concrete were systematically analyzed. Based on the analysis of the strain in the steel tube and the stress state of the confined concrete during testing, a method for calculating the effective confining stress on the core concrete is proposed. A uniaxial compressive stress–strain model for C-shaped steel tube-confined concrete is developed based on the Mander model. Comparisons show that the proposed model agrees well with the experimental stress–strain curves, with predicted peak stresses within 5% of experimental values and predicted peak strains within 7% deviation. Full article

Automotive plastic parts present multiple challenges for Computer-Aided Engineering (CAE) simulation modeling, including complex thin-walled geometries, difficulties in meshing fine features (e.g., clips and snap-fits), and time-consuming manual processing with inconsistent quality. To address these issues, this paper proposes an automated method for generating mid-surface meshes. The proposed approach integrates AI-based feature recognition, point cloud registration, and geometric fitting. First, a specialized point cloud dataset consisting of 132,000 samples of plastic part features was constructed. Using a PointNet++ model, precise semantic segmentation of typical features, such as clips and backing plates, was achieved. Subsequently, a library of typical features was established, and an FPFH-ICP point cloud registration strategy was implemented. Based on the matching rate, an adaptive selection between two processing paths, direct standard mesh replacement and segmentation-fitting generation was performed. For features with low matching rates, a suite of segmentation-fitting algorithms was proposed. These algorithms incorporate incomplete cylinder parameter extraction, Monte Carlo boundary identification, and internal point cloud reordering, thereby facilitating high-quality mid-surface mesh generation for complex topological structures. Finally, experimental validation was conducted on typical automotive interior plastic parts as well as on new cross-platform vehicle models. The results demonstrate that the proposed method reduces mesh modeling time by 67% while preserving the accuracy of geometric feature restoration. The mesh quality compliance rate increases from 52.27% to 90.9% with the proposed method, reaching a level comparable to that of professional manual meshing. In cross-platform validation, the proposed method maintained high accuracy. Consequently, this approach significantly enhances the intelligence and engineering reliability of CAE pre-processing, providing effective technical support for the automated simulation modeling of complex thin-walled components. Full article

The rapid increase in memory power density has made memory thermal management a critical challenge in high-density servers, where extremely limited DIMM spacing significantly reduces the effectiveness of air cooling. Compared with CPUs and GPUs, memory-level liquid cooling has received less systematic study, particularly regarding the influence of cold plate structural design on thermal and hydraulic performance under realistic server conditions. In this paper, three engineering-feasible memory liquid cooling solutions (water-flowing cold plate, clamp-type cold plate and heat-pipe-based cold plate) are experimentally compared on a high-density server system. Experiments are conducted at coolant inlet temperatures of 37–50 °C with a fixed flow rate of 0.8–1.5 L/min. Memory, CPU, and voltage regulator temperatures, as well as system pressure drop, are measured. Results show that memory temperature increases with coolant inlet temperature for all configurations, while their relative performance remains unchanged. Memory temperatures range from 62.04 to 71.13 °C, 57.65 to 66.98 °C, and 66.22 to 76.07 °C, with corresponding pressure drops of 24.19–26.69 kPa, 32.73–35.98 kPa, and 27.00–29.96 kPa. These results provide insight into the role of coolant distribution and flow-path topology in memory thermal performance. Full article

Ochetobibus elongatus (Kner) is a migratory fish found in the Yangtze River basin and areas south of it, and listed as a critically endangered (CR) fish on the China Red List of Vertebrates. To achieve group recovery and artificial breeding, this study investigated the dietary characteristics of O. elongatus based on high-throughput sequencing of its intestinal contents, and its digestive system morphology, and its histology. Results showed that the digestive system of O. elongatus lacked a stomach and mainly consisted of the oropharynx, pharyngeal teeth, esophagus, intestine, and anus. The gut index was 0.88, with clear segmentation of the foregut, midgut, and hindgut, and the visceral mass index was 7.35%. Histological analysis of the digestive system revealed the presence of keratinized dental plates or pharyngeal teeth in the pharynx, as well as a high density of taste bud cells in the soft palate of the oral cavity. The surface layer of the intestinal villi contained numerous mucous cells, with the average number of mucous cells per villus gradually increasing from the esophagus to the hindgut, and the foregut having the longest and most abundant mucosal folds. The esophagus exhibited well-developed circular and longitudinal muscle layers, while in the hindgut, both the circular and longitudinal muscle layers were slightly thicker than those in the midgut. High-throughput sequencing of the intestinal contents of O. elongatus revealed the following phyla based on 18S V4 meta-barcoding: Chlorophyta, Diatoms, Arthropoda, Basidiomycetes, and Ascomycetes, with the genus Hypophthalmichthys and algae being the main classifications. In contrast, based on COI meta-barcoding, the study newly identified the phyla Cnidaria and Mollusca, with the genera Chlorophyta, Scenedesmus, Pectinodesmus, and zooplankton such as Pseudodiaptomus. Metagenomic sequencing revealed that the gut microbiota at the phylum level was predominantly composed of Pseudomonadota, Ascomycota, Basidiomycota, Chytridiomycota, and Bacillota, with key genera including Cetobacter, Pseudomonas, Acinetobacter, Aeromonas, and Clostridium. This study indicates that O. elongatus is an omnivore with carnivorous tendencies. Basic biological research on O. elongatus is of great significance for the restoration of the population, artificial breeding, and the development of its artificially formulated feed. It also provides important data for the formulation of biodiversity conservation measures. Full article

Some actinobacterial species have been reported to improve plant growth due to their roles as biostimulants and biological control agents. In this study, the effect of actinobacterial isolate 27, obtained from the rhizospheric soil of melon plants and identified as Streptomyces calvus, was evaluated on the growth of Arabidopsis thaliana and tomato plants. In Arabidopsis, in vitro assays showed that after seven days of interaction, isolate 27 increased fresh weight by 1.4-, 1.5-, and 2.3-fold and lateral root number by 1.7-, 1.3-, and 2.5-fold under physical contact and split-plate systems (MS and ISP2 media), respectively, compared with non-inoculated plants. An increased β-glucuronidase (GUS, encoded by the uidA gene) signal was observed in primary and lateral roots of the Arabidopsis DR5::uidA reporter line during both interaction types, suggesting the activation of auxin-responsive pathways. In addition, isolate 27 rescued the rhd6 (root hair defective 6) mutant phenotype, restoring root hair formation. Gas chromatography-mass spectrometry (GC-MS) analysis revealed that isolate 27 emitted volatile organic compounds (VOCs), including an alcohol and several sesquiterpenes, and that this profile changed during interaction with Arabidopsis plantlets. In soil-based pot assays, inoculation with isolate 27 significantly enhanced the development of Arabidopsis plants after 23 days, both when applied alone and in co-inoculation with Trichoderma atroviride. Furthermore, isolate 27 stimulated tomato plant growth, leading to significant increases in fresh and dry biomass, as well as shoot and root lengths after 28 days. Overall, these results demonstrate that S. calvus isolate 27 promotes plant growth and development through the production of bioactive compounds that modulate plant growth pathways, including hormonal responses, highlighting its potential as a bioinoculant for sustainable and productive agricultural systems. Full article

In this study, the microstructure and mechanical properties of ultrasonic welded joints between large-diameter aluminum wire and Cu (Ni-plated copper) terminals were systematically investigated, to reveal the underlying fracture mechanisms. The cross-sectional morphology, interfacial microstructure, and mechanical properties of the two types of welded joints are investigated. The results indicate that ultrasonic welding produces well-structured Al-Cu and Al-Ni joints. Under the same welding process parameters, the Al-Cu joint exhibits many pores, while the Al-Ni joint has no pores in its microstructure. The interfacial region of the Al-Cu joint presents various morphologies, such as flat bonding, interlocking, and eddy current patterns, whereas the Al-Ni joint interface is flat. No significant atomic diffusion phenomenon occurs between the interfaces of the two types of joints. The tensile strength of the Al-Cu joint is 53 MPa, with fracture modes including ductile fracture and brittle fracture, whereas the tensile strength of the Al-Ni joint is 50 MPa, with a failure mode of pull-out fracture. In working conditions requiring ultrasonic welding of aluminum and copper, nickel-plated copper can be used as a substitute for copper to prevent electrochemical corrosion between aluminum and copper. Full article

Background: Additive manufacturing provides a rapid and flexible alternative to conventional micromolding for producing microneedle systems. This study evaluates the potential of a cost-effective LCD 3D printer for fabricating microneedle arrays (MNAs) and investigates how the geometry of MNAs and the formulation of hydrogel influence the performance of lidocaine-coated arrays. Methods: Conical and pyramidal MNAs, along with a reservoir plate, were designed and manufactured. Lidocaine-loaded and placebo hydrogels with two different polymer concentrations were prepared for dip-coating using both single and multilayer applications. Mechanical resistance and insertion efficiency were evaluated under controlled compression. The physicochemical behavior of the hydrogels were characterized, including pH, spreadability, adhesiveness, and rheological behavior. The uniformity of the coating was analyzed using 3D confocal microscopy. Drug loading was quantified by HPLC, drug release was studied using Franz diffusion cells, and skin penetration was confirmed by 3D confocal imaging and Raman mapping. Results: Conical microneedles exhibited high mechanical integrity, showing only a 2% reduction in height compared to 4% for pyramidal MNAs. Stronger drug signals were achieved in deeper skin layers with the conical geometry, indicating enhanced penetration, while pyramidal MNAs provided slightly higher lidocaine loading due to their larger lateral surface. Hydrogels with higher polymer content produced more stable, uniform coatings, particularly when applied in three layers. Rapid drug release was observed, with over 70% of the drug delivered within minutes. Conclusions: LCD 3D printing offers a cost-effective approach for fabricating MNAs with suitable structural stability and sharpness. The optimized hydrogel formulation ensured uniform coverage, as well as maximal and consistence penetration, making this platform a promising candidate for the dermal delivery of other potent drugs. Full article

The potential of Trichoderma nordicum (Hypocreales, Ascomycota), a recently described species, for antagonism and use in the biocontrol of oomycete-caused plant diseases is unknown. Trichoderma is a well-known genus for containing microbial antagonists and biocontrol agents. The T. nordicum in this study was isolated from decomposing wood, and rpb2 and tef1 barcode sequencing demonstrated that the isolates were a match to the reference T. nordicum and T. nigricans strains. Since T. nordicum was described before T. nigricans, the isolates were assigned to T. nordicum, although taxonomic uncertainty between these species requires future clarification. In dual-culture confrontation assays, T. nordicum overgrew five economically important oomycete plant pathogens (Phytophthora capsici, P. sojae, Pythium aphanidermatum, P. myriotylum, and Globisporangium ultimum). The inability to recover viable P. aphanidermatum and P. capsici from the parts of the plate overgrown by T. nordicum, coupled with protease and endo-cellulase activities, correlates with T. nordicum having antagonistic abilities. Inoculation with T. nordicum preventively reduced the levels of cucumber seedling damping-off caused by P. aphanidermatum by up to 70%. The T. nordicum biocontrol effects against pepper blight caused by P. capsici were greater than 80%, compared to an autoclaved T. nordicum spore control. T. nordicum could also significantly promote the growth of pepper, with plant weight increased by up to 40%, compared to an autoclaved-spore control. In contrast, T. nordicum could not be used to control Pythium soft rot of ginger caused by P. myriotylum, even though P. myriotylum was overgrown by T. nordicum, suggesting host- or pathosystem-specific factors influence biocontrol efficacy. In summary, T. nordicum is a promising biocontrol agent for use in the control of pepper blight caused by P. capsici, and also has potential for use in the control of other oomycete-caused plant diseases in vegetable production systems. Full article

Two-phase displacement between cement slurry and drilling fluid in wellbore systems is inherently nonlinear, interface-dominated, and strongly affected by geometric confinement, posing substantial challenges to efficient and stable numerical simulation. Conventional CFD approaches rely on mesh discretization and explicit interface tracking, which become computationally demanding and sensitive to grid quality in complex geometries and convection-dominated regimes. To address these limitations, this study develops a unified physics-informed neural network (PINN) framework for directly solving the coupled incompressible Navier–Stokes and Volume of Fluid (VOF) equations governing pressure-driven displacement. The framework is first validated against canonical transient flows and then applied to two-phase displacement in parallel-plate channels, semicircular bends, and a casing–annulus geometry representative of well cementing operations. The predicted velocity, pressure, and volume fraction fields exhibit strong agreement with ANSYS Fluent (2024R1) results, with relative errors generally around 5%, thereby demonstrating physical consistency and numerical stability without mesh generation or pressure–velocity splitting, while also showing favorable computational efficiency for the cases considered. Sensitivity analyses demonstrate that a smoother casing-shoe geometry significantly enhances PINN convergence, while higher Péclet numbers deteriorate training stability by increasing convection-dominated stiffness and optimization difficulty. The results demonstrate that the proposed PINN framework, with its mesh-free and geometrically flexible characteristics, is a promising approach for modeling multiphase displacement in cementing applications. Full article

This study investigates the mechanism of cell death associated with discharge plasma treatment from the perspective of electrical energy injection, using equivalent circuit network analysis to represent cells, buffer solutions, and well plates as electrical components. Our analysis demonstrated that the observed cell death cannot be adequately explained by a One-Step Model, which assumes that cell death occurs when the total injected electrical energy simply reaches a specific threshold. Accordingly, we proposed a Two-Step Model that explicitly incorporates biological tolerance to external stimuli. In this model, a stimulus accumulates only when the instantaneous power exceeds a primary threshold, and cell death is induced only when this accumulated stimulus surpasses a secondary threshold of energy. The proposed Two-Step Model successfully reproduced the experimental cell death data. These findings suggest that plasma-induced cell death is not a simple physical destruction process governed solely by cumulative energy, but instead reflects a biologically regulated response characterized by a specific power-dependent tolerance. Consequently, this Two-Step Model could provide a theoretical foundation for future optimization of delivery conditions for macromolecules such as messenger RNA (mRNA). Full article

Background/Objectives: Peritoneal micrometastases (micromets) remain a major barrier to durable cytoreduction in ovarian and other intra-abdominal cancers because lesions are difficult to visualize and are often resistant to systemic therapy. Liposomal doxorubicin (Dox) improves pharmacokinetics but can be limited by slow intratumoral release. Porphyrin-phospholipid (PoP) liposomes enable near-infrared light–triggered release of Dox (chemophototherapy (CPT)), creating an opportunity for intraoperative fluorescence-guided treatment planning and monitoring. Here, we evaluate a laparoscopic fluorescence imaging platform for quantifying light-triggered drug delivery. Methods: LC-Dox-PoP was applied to SCC2095sc and SKOV-3 cultures in 2D monolayers and 3D spheroid clusters. Dox fluorescence was quantified using a laparoscopic fluorescence imaging system over 1–9 μg/mL concentrations and compared with standard well-plate reader measurements. Porphyrin fluorescence was monitored to assess spheroid localization and photobleaching after activation light exposure. Results: For both cell lines, Dox fluorescence exhibited an approximate 4-fold increase at the maximum administered LC-Dox-PoP concentration, following a linear trend in both SCC2095sc and SKOV-3 cultures (R² = 0.97, 0.98 for 2D and R² = 0.98, 0.98 for spheroids). Laparoscope-derived fluorescence measurements agreed with well-plate reader measurements (R² = 0.89–0.96). Porphyrin fluorescence provided stronger complementary contrast for localizing spheroid constructs and decreased after activation light exposure, consistent with photobleaching during triggered release. Conclusions: These results support a quantitative imaging framework for fluorescence-guided monitoring of light-triggered liposomal drug release and may enable individualized CPT dosimetry for peritoneal micrometastases. Findings in SCC2095sc additionally suggest potential relevance of fluorescence-guided CPT for head and neck/oral cancer, where localized post-resection adjuvant treatment may improve control of residual disease. Full article

The Fused Filament Fabrication (FFF) process has established itself as a key technology in prototyping and development and has garnered increasing interest in academic research. A substantial body of research on the FFF process has focused on the influence of process parameters on the resultant material/part properties. The thermal history of the printed part has proven itself as one of the most important factors in the printing process. It influences warping behavior, dimensional accuracy, build plate adhesion, as well as the mechanical properties of the finished part. A key requirement for understanding the influence of thermal history is the knowledge of the thermal properties of the considered material. In this study, the temperature-dependent thermal properties (isobaric heat capacity, thermal conductivity and density) of an unfilled polyamide 6 material for 3D printing are provided. Special attention is given to discussing the challenges associated with measuring these properties, particularly regarding how well the measured values represent the actual conditions during the printing process. Full article