Abstract The design method for slender fiber-reinforced polymer (FRP) reinforced concrete (FRP-RC) rectangular columns based on the nominal curvature is not yet included in the new Eurocode 2 Annexure R. However, a proposal to expand Eurocode 2 in this regard is presently being considered and would also be included in the new DAfStb guideline for nonmetallic reinforcement. Additionally, other national codes, such as ACI 440.11-22 and CSA S806-12, also require load–moment capacity curves for the design of FRP-RC column cross sections. However, distinct load–moment capacity curves are required for each type of FRP bar in FRP-RC columns due to their different modulus of elasticity and ultimate design strain limits. This paper presents a novel concept of universal interaction diagrams, which can be used regardless of the type of FRP reinforcement bar such as glass, carbon, basalt, or aramid FRP. This significantly enhances both its usability and practicality in structural design. These diagrams only depend on the concrete strength, reinforcement configuration, and cover-to-depth ratio. This paper introduces provisions to expand Eurocode 2, provides universal interaction diagrams for rectangular cross sections for cross-section design, and provides universal interaction diagrams for slender FRP-RC columns with slenderness ratios of 40, 60, and 80, all of which are based on the nominal curvature method. The universal interaction diagrams for slender columns bypass the iterative solution of the presented equations and therefore have high practical value. Finally, the paper provides three worked examples that illustrate how to analyze and design short and slender FRP-RC columns using the presented diagrams.
Hetero-agglomeration of micron- and submicron-sized particles enables the formation of all-solid-state battery cathode materials with enhanced safety and energy density. This study investigates a turbulent pipe flow process for mixing lithium iron phosphate (LiFePO4, LFP), lithium indium chloride (Li3InCl6, LIC), and carbon black (CB) to form three-component hetero-agglomerates. The analysis aims to identify suitable pipe dimensions and evaluate how different mixing configurations affect agglomerate size, composition, and structure. The investigation employs a dedicated simulation framework utilizing a mesh-free representation of turbulent flow fields derived from direct numerical simulation datasets. Lagrangian particle tracking incorporates an improved discrete random walk model, while stochastic agglomerate structure simulations account for various turbulent collision mechanisms, hydrodynamic interactions, and breakup events. Prior to simulations, virtual CB aggregates were stereologically reconstructed from scanning electron microscopy images, the particle size distributions were determined using laser light diffraction, and the surface energies of all materials were determined from contact angle measurements using the Owens-Wendt-Rabel-Kaelble method. Simulations examined parallel mixing and sequential premixing configurations (LFP-CB, LIC-CB, and LFP-LIC) across various pipe diameters. For parallel mixing under experimental process conditions, an 18 mm pipe diameter proved optimal, achieving maximum particle capture in agglomerates at a downstream distance of 2.73 m. Premixing diameters were selected based on mixing length and deposition. The mixing configuration significantly influences the agglomerate composition, material-specific mixing quality measures, and the contact-pair distribution. The findings provide concrete recommendations for experimental process design regarding pipe dimensions and mixing strategies, while the influence on electrochemical properties requires further investigation.
This study examines associations between student teachers’ professional competencies and elementary school children’s learning behavior, and explores how children’s learning behavior relates to their reading achievement and motivation. During a five-month professionalization program, 33 student teachers implemented a differentiated, evidence-based reading training in small groups with 216 children. Student teachers’ self-reported knowledge, self-efficacy, and instructional beliefs were assessed before the training. After each training session, the student teachers rated children’s learning behavior. Children’s reading achievement and motivation were measured with standardized assessments before and after the training. Structural equation modeling revealed that student teachers’ self-efficacy, transmissive, and constructivist beliefs were significantly associated with children’s learning behavior, which positively predicted children’s reading achievement and motivation development. Higher student teachers’ self-efficacy corresponded with greater motivation and fewer disruptions during training. Findings should be interpreted in light of the non-causal study design and the use of student teachers’ self-reports and ratings of children’s learning behavior. Overall, results highlight the role of teacher competencies in students’ learning processes even in standardized learning settings.
For 50 years, the standard model of particle physics has been very successful in describing subatomic phenomena. In the past quarter of a century, this was challenged by a mismatch between its predictions and precision measurements of the anomalous magnetic moment of the muon, aμ. This disagreement was eventually reconciled, first through a determination in an ab initio lattice calculation1 of the most uncertain theoretical contribution, the leading-order hadronic vacuum polarization (LO-HVP), a μ LO-HVP , and subsequently by experimental results2 and updates of the reference standard-model predictions using lattice results for a μ LO-HVP (ref. 3). Here we present a new calculation for this crucial quantity, obtaining a μ LO-HVP = 715.1 ( 2.5 ) ( 2.3 ) [ 3.4 ] × 1 0 - 10 . This reduces the uncertainty by a factor of 1.6 compared with our earlier computation1. We use a hybrid approach that includes a small, long-distance contribution from experiments in a low-energy regime in which they all agree. Our approach combines the strengths of experimental and lattice data in different energy ranges, achieving better precision than with either alone. Our lattice quantum chromodynamics (QCD) simulations are performed on finer lattices than in ref. 1, allowing for an even more accurate continuum extrapolation. Combined with the calculations of the other standard-model contributions summarized in ref. 3, our result leads to a prediction that differs from the recent measurement of aμ (ref. 4) by only 0.5 standard deviations. This provides a notable validation of the standard model to 11 digits.
Understanding patterns of adolescent political participation is essential for healthy democracies. Drawing upon data from Greek youth (n = 589, Mage = 15.1), this study (1) identified distinct profiles of adolescent political participation, (2) examined predictors of profile membership, and (3) explored transitions between profiles across a one-year period. Latent profile analyses uncovered three profiles that differentiated between their level of participation in both latent and manifest forms: 'informed enthusiasts' (90.3%), 'activists' (7.4%), and 'involved conventionalists' (2.2%). Political efficacy, national identity processes, political alienation, and perceived ethnic discrimination were predictive of profile membership. Our exploratory analysis revealed stable profile membership across one year. Our findings highlight the multifaceted nature of youth political participation and underscore the need to broaden its understanding in research and policy.
