Experimental vs. numerical investigation of free surface formation in an unbaffled eccentric stirred tank

An elastically asymmetric bonded-particle model for stress wave propagation in bimodular rock masses

Vortex-induced vibration of a circular cylinder near a free surface

Experimental investigation of axis switching and local heat transfer in multiple elliptical free surface water jet impingement

Hydrodynamic interaction between a free surface water wave and a bottom-fixed body near a vertical breakwater by using BEM with a novel Neumann-to-Dirichlet boundary condition

Unsteady behavior of vaneless space water ring and draft-tube free surface during synchronous condenser operation of pump-turbine

Melting in two-dimensional (2D) systems exhibits physics absent in three dimensions, yet its mechanism has been debated for decades. The prevailing Kosterlitz-Thouless-Halperin-Nelson-Young (KTHNY) theory describes 2D melting as two continuous transitions in the bulk with an intermediate hexatic phase. While this framework can describe bulk behavior at the transition, it does not account for the influence of free surfaces. Here, using single-particle imaging of optically-driven 2D colloidal solids, we report that melting with free surfaces proceeds via a double wetting pathway, where an inhomogeneous layer with hexatic order forms between the bulk solid and an outer quasi-liquid layer. Prior to melting, the thicknesses of both wetting layers grow into the bulk following a power-law divergence. The quasi-hexatic layer penetrates the bulk ahead of the quasi-liquid layer, giving rise to separate solid-hexatic and hexatic-liquid transitions. Different from the KTHNY scenario, in which dislocations nucleate as bound pairs in the bulk, the free surface acts as a prolific source that continuously emits dislocations into the solid, driving the invasion of the wetting layers. These results present a surface-initiated pathway for 2D melting, offering insights into colloidal matter, 2D materials, and condensed matter physics.

Starting with an all-atom potential energy surface, we apply a recently introduced intramolecular coarse-graining framework to incorporate nuclear quantum effects in molecular cluster simulations without resorting to path-integral methods. As in previous work [ J. Chem. Phys. 2025, 163, 131101], the configuration space is partitioned into slow intermolecular degrees of freedom and fast intramolecular vibrational modes. Here, the latter are treated quantum mechanically within the local harmonic approximation, allowing zero-point energies and finite-temperature vibrational free energy contributions to be included. The resulting temperature-dependent effective free energy surface is sampled using classical Monte Carlo, yielding equilibrium properties that account for nuclear quantum effects while sampling a lower-dimensional configurational space. The approach is applicable to systems in which the slow intermolecular modes are well-described classically. We use the method to assess the nuclear quantum and isotope effects in a benzene cluster and demonstrate that, although very small, they can be quantified.

Two-dimensional (2D) electrides, featuring an intrinsic nearly free surface electron gas and an ultralow work function, provide an effective platform for efficient charge injection. Their unconventional electronic structure makes them attractive electrode materials for 2D semiconductors. However, in van der Waals (vdW) metal-semiconductor junctions (MSJs), weak interlayer coupling introduces a tunneling barrier that severely limits carrier injection, despite suppressed interfacial disorder and Fermi-level pinning (FLP). Resolving this long-standing incompatibility between weak FLP and efficient carrier tunneling remains a key challenge in contact engineering for 2D electronics. Using first-principles calculations, we demonstrate that the MSJs formed between the 2D electride Ca2N and MX2 (M = Hf, Zr; X = S, Se) simultaneously achieve tunneling-barrier-free transport and intrinsic Ohmic contact behavior. Ca2N forms strongly coupled donor-acceptor interfaces with MX2, enabling barrier-free carrier injection while maintaining weak FLP. The MSJs exhibit intrinsic Ohmic contact behavior with a tunneling probability of 100%. Transport simulations further confirm the contact performance, with a ZrS2/Ca2N-based device delivering a current nearly 104 μA/μm at a low bias of 0.2 eV. Moreover, bromination of the noncontact Ca2N surface enhances high environmental stability without degrading interfacial electronic properties. These results establish 2D electrides as promising electrode materials for transition-metal dichalcogenide (TMD)-based nanoelectronics.

A material family that intrinsically hosts topological, high-mobility semiconducting and ferroelectric properties offers a platform for exploring new physical phenomena and advancing next-generation electronics and optoelectronics. Bismuth-based chalcogenides and oxychalcogenides are especially promising in this context due to their compositionally tunable functionalities. However, their development is hindered by the lack of a general, scalable synthesis method, as existing approaches are material-specific and rely on costly, lattice-matched substrates. Here, we report a synergistic epitaxy strategy that pairs elemental precursors with an atomically engineered K+-free mica surface, enabling universal growth of nine millimeter-sized bismuth-based chalcogenide and oxychalcogenide single crystals, including topological insulators, high-mobility semiconductors, and ferroelectrics/dielectrics. High-quality materials enable high-performance transistors and broadband photodetectors with high responsivities. Furthermore, we demonstrate their integration into large-scale, uniform arrays and showcase their imaging capabilities across visible to infrared bands. This work establishes a scalable and material-agnostic synthesis framework, unlocking the systematic exploration and device integration of this multifunctional material family.

This work investigates, based on laboratory experiments, the influence of particles on the drainage of a bottle filled with an isodense suspension. Similarly to the drainage of a pure liquid, the flow rate remains constant during the whole emptying process and is primarily controlled by the size of the exit hole. Despite a hole-to-particle size ratio that would normally promote clogging, no such events are observed due to the periodic entrainment of air bubbles. The presence of particles causes a slight decrease in flow rate when increasing the particle initial packing fraction. Even for initial packing fractions of up to 60 %, it only decreases by at most 20 %. Revisiting the model of Clanet & Searby (2004) J. Fluid Mech . 510 , 145–168, the flow rate is found to be linked to the rise velocity of the bubbles, which is surprisingly nearly independent of the packing fraction, even for values as high as 60 %. This counterintuitive result suggests that the suspension becomes heterogeneous, with a particle-depleted region in the pathway of the bubbles. Moreover, during drainage, the suspension exiting the bottle has a smaller packing fraction than the initial suspension, leading to an accumulation of particles inside the bottle and therefore an increase in the global packing fraction inside the vessel. When this latter reaches a critical value close to random loose packing, particles start to emerge above the liquid free surface. Based on accurate measurements that enable the computation of the mean packing fraction at all times, a model is proposed to describe this transition.

Transition interface sampling (TIS) and replica exchange TIS (RETIS) are powerful methods for computing rates of rare events inaccessible to straightforward molecular dynamics simulations. Path reweighting extends their output, enabling the evaluation of diverse thermodynamic and kinetic quantities, including reaction prediction metrics, activation barriers, committor functions, and free energies. The recently developed ∞RETIS algorithm boosts parallel efficiency through asynchronous replica exchanges in the infinite-swap limit, thereby eliminating the wall-time bottlenecks of conventional RETIS. This approach introduces fractional samples and biased sampling distributions, requiring a generalized path reweighting framework, for which we derive expressions demonstrating how exact dynamic and thermodynamic variables can be computed. We then focus on a special class of free energy surfaces defined by history-dependent conditions, whose values are influenced by kinetic factors such as particle mass and friction, unlike standard unconditional free energy surfaces. Even with suboptimal reaction coordinates, these conditional free energies can reveal kinetically relevant barriers that may be misrepresented by standard unconditional free energies, thereby providing a rigorous and versatile tool for characterizing complex molecular transitions.

Efficient biomanufacturing of vitamin E succinate in non-aqueous media via synergistic computational evolution and immobilization of lipase.

• Weak formulation of configurational forces (CFs) in the VEM is derived. • Automated mesh refinement based on CFs improves VEM approximations. • Accurate crack tip loading analyses are demonstrated. • Internal moments in virtual elements must not be disregarded in fracture analyses. • Efficient and accurate crack growth simulations with non-convex crack tip elements. The Virtual Element Method (VEM) constitutes a generalization of the Finite Element Method, allowing for spatial discretizations with arbitrary, even non-convex polygonal elements. This offers significant advantages, particularly for problems involving moving discontinuities, local stress concentrations, or multiple phases with distinctly different dimensions. The theory of configurational forces (CF) represents a very flexible basis to quantify driving forces for virtual defect displacements within a thermodynamical framework, and at the same time provides an indicator for the local mesh quality in numerical calculations. In combination, the VEM and the CF theory thus constitute an effective basis for numerical simulations of crack growth within the context of a classical approach with strong discontinuities and sharp crack tips. Challenges to cope with are attributable to the lacking knowledge of shape functions within virtual elements, the numerical integration on arbitrary polygonal elements, and the requirement of an automated generation of polygonal meshes. The weak form of the energy-momentum balance is derived from a variational approach, uniquely separating nodal CFs acting at free surfaces from those driving the defect. Furthermore, internal degrees of freedom, which are inherent to higher-order virtual elements, have to be interpreted within the context of CFs. Unphysical, so-called spurious, CFs are exploited for an improved mesh design at crack tips, eventually generating accurate results of crack tip loading and crack path simulation.

Effect of stiffness on the propulsive performance and vortex dynamics of a semi-active flapping foil near a free surface

In this work, we report a new version of the HOS-Ocean code which is an open-source solver for deterministic nonlinear ocean wave propagation. The numerical model makes use of the so-called High-Order Spectral method, which ensures high efficiency and accuracy. This new release includes i) additional physical features such as spatially varying current and bathymetry together with dedicated models to account for wave-breaking, and ii) numerical developments with parallelization of the code through MPI as well as a more user-friendly code (pre-built binaries available, and simplified building procedure and operation). HOS-Ocean v2.1 is released as open-source, available from GitLab , developed and distributed under the terms of GNU General Public License (GPLv3). Along with the source code, detailed documentation under Sphinx format is available. Program Title: HOS-Ocean CPC Library link to program files: (to be added by Technical Editor) Developer’s repository link: https://gitlab.com/lheea/HOS-Ocean Code Ocean capsule: (to be added by Technical Editor) Licensing provisions(please choose one): GPLv3 Programming language: Fortran Supplementary material: Journal reference of previous version: Comput. Phys. Commun. 203 (2016) 245–254. Does the new version supersede the previous version?: Yes Reasons for the new version: Enhancement of capabilities and ease of use Summary of revisions: Implementation of additional physical features: spatially varying current and bathymetry, and inclusion of dedicated models to account for wave-breaking. Numerical developments with parallelization of the code through a Message Passing Interface (MPI) [1] and more user-friendly code (pre-built binaries available, and simplified building procedure and operation). Nature of problem: HOS-Ocean has been developed to study the propagation of highly nonlinear sea-states over large domains and long duration. Regular and irregular wave fields can be studied, including the effect of directionality (short-crested seas). Solution method: HOS-Ocean provides an implementation of the High-Order Spectral method, which solves the problem formulated on the free surface by means of a pseudo-spectral method. Time integration uses an adaptive Runge-Kutta 4(5) scheme. Additional comments including restrictions and unusual features: In short-crested seas, the individual treatment of wave-breaking events with the Barthelemy-Tian model [1,2] is not yet available. The simulation of directional sea states is consequently limited to non-breaking conditions with this breaking model. The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. [1] http://www.mpi-forum.org [2] B.R. Seiffert, G. Ducrozet, F. Bonnefoy. Simulation of breaking waves using the high-order spectral method with laboratory experiments: wave-breaking onset. Ocean Modelling, 119:94–104, 2017.[3]B.R. Seiffert, G. Ducrozet. Simulation of breaking waves using the high-order spectral method with laboratory experiments: wave-breaking energy dissipation. Ocean Dynamics, 68(1):65–89, 2018.

This study aimed to compare the effectiveness of ultrafiltration-diafiltration (UF-DF) and isoelectric precipitation (IEP) for producing albumin (Alb) and globulin (Glo) fractions from hemp protein isolate (HPI), and to compare their structural and surface properties as well as solubilities. Compared to the Alb-IEP, the Alb-UFDF exhibited higher protein content (88.25 vs 73.76%), greater surface hydrophobicity (48.94×103 vs 38.80×103a.u.), higher free sulfhydryl groups (25.12 vs 14.78μmol/g), a more negative ζ-potential (-22.36 vs -10.06mV), and higher α-helix content (9.03 vs 2.99%), indicating a better-preserved conformational structure. This structural integrity resulted in higher solubility for the Alb-UFDF compared to the Alb-IEP, although both albumin fractions remained highly soluble across all pH values. Protein profiles showed a slight contamination of the Alb-UFDF with 7S globulin. Both UFDF and IEP globulin fractions exhibited similar protein content (∼81%) and ζ-potential (∼-8mV), but the Glo-UFDF showed higher free sulfhydryl content (27.90 vs 18.41μmol/g) and surface hydrophobicity (100.22×103 vs 16.21×103 a.u.), indicating more pronounced denaturation for the Glo-IEP. Moreover, the solubility of the Glo-IEP was lower, particularly at pH8 (18.31 vs 59.09%). Overall, UF-DF better preserved the conformation and solubility of hemp albumins and globulins compared to IEP, however the lower recovery yields indicate that further process optimization is required. Future work should assess the techno-functional properties of these fractions to evaluate their potential applications in food systems.

Optimizing hydraulic performance in free water surface wetlands: Impacts of emergent plant spatial distribution patterns

Site-specific phosphorylation modulates p16/CDK4 binding dynamics and energetics: Insights from molecular simulations.

The dynamic separation of bauxite has gradually gained public awareness following the systematic study and investigation of this phenomenon by the International Maritime Organization (IMO). Researchers on solid bulk cargo urgently need an assessment criterion to determine the trigger of dynamic separation, conduct a subsequent risk assessment, and fill this almost empty space. This study starts from the basic definition of dynamic separation and determines the trigger of dynamic separation by monitoring the phase point of the top sample transition from solid to liquid (free liquid surface). Therefore, a series of shaking table tests for saturated bauxite are carried out and a rigid mold is developed to expand the applicability of the evaluation criteria. The dynamic separation trigger point is determined by dynamically monitoring the apparent viscosity and calculating the minimum point of the radius of curvature function. In this paper, the validity and uniqueness of the criterion are verified from three perspectives: particle size distribution (PSD), pore property parameters (e, n), and state response indicator (Ru). The assessment criteria and standardized testing methods proposed in this study can accurately determine the trigger of dynamic separation and provide the assessment basis and theoretical basis for subsequent research on dynamic separation.