Cenospheres are plausible intermediates in entrained flow gasification (EFG) of biogenic suspension fuels. However, their structure and reactivity remain poorly understood, limiting the accuracy of numerical simulations of entrained flow gasifiers.The present study characterizes cenospheres from two experiments in a technical entrained flow gasifier using beech wood pyrolysis oil (PO) and char suspensions (slurry; POC) under intentionally low air ratios (0.35). Structural features and CO2 gasification kinetics are investigated, and mass transport effects under technically relevant conditions (1000 – 1500 °C, 10 bar CO2) are evaluated.A broad particle size distribution of the cenospheres (100 – 800 µm) is identified. Micro computer tomography reveals internal macro-structures ranging from uniformly distributed porosity to a porous shell, with embedded char particles in POC cenospheres.Micro- and mesoporosity are analyzed via argon physisorption. Only POC cenospheres show microporosity, which is assigned to the char particles. Structural ordering determined by X-ray diffraction (XRD) is stronger for smaller cenospheres. The evolution with increasing particle diameter differs between POC and PO cenospheres, with radial expansion of the graphene layers prevailing in POC cenospheres, while both radial expansion and graphene stacking vary in the structured domains in PO cenospheres.Reaction kinetics in CO2 (5 – 20 bar, 810 – 850 °C) are determined in the differential fixed bed reactor for 200 – 400 and 600 – 800 µm fractions. The reaction rate increases with increasing temperature and CO2 partial pressure as described by the Arrhenius and the power law model (activation energy: 210 – 242 kJ/mol; reaction order: 0.2 – 0.3). Especially the mantle area-to-volume ratio of the stacked graphene layers derived from XRD and the mesopore surface area are found to impact the reaction rate.
We calculate the unpolarized and polarized three--loop anomalous dimensions and splitting functions $P_{\rm NS}^+, P_{\rm NS}^-$ and $P_{\rm NS}^{\rm s}$ in QCD in the $\overline{\sf MS}$ scheme by using the traditional method of space--like off shell massless operator matrix elements. This is a gauge--dependent framework. For the first time we also calculate the three--loop anomalous dimensions $P_{\rm NS}^{\rm \pm tr}$ for transversity directly. We compare our results to the literature.
Journaling enables students to reflect on their learning processes and thereby strengthen their self-regulation, a key competency for meeting academic goals. Previous work has shown that students benefit from digital support when creating learning journals, such as through mobile learning journaling systems. Yet, a major issue with such systems is the rapid decline in user motivation and engagement, often occurring after only a brief period of use. To address this challenge, we present a mobile chatbot-based learning journaling system that guides students through structured reflective journal entries and supports writing through an LLM-based journaling assistant. The novel system combines (1) an example-based built-in course that teaches reflective journaling through modeled responses with (2) an interactive journaling assistant that scaffolds students’ entries by generating follow-up questions and rewrite suggestions. In a randomized field experiment with 179 students using the system over 22 days, we examined the impact of both design principles on intrinsic motivation and behavioral engagement. While our results indicate that the built-in course can increase intrinsic motivation, we find no evidence that the LLM-based journaling assistant improves intrinsic motivation. Regarding engagement, both design principles provide benefits in different ways: the course shows a rather constant positive influence, whereas the LLM-based assistant appears to form a feedback loop with continued use, increasing engagement over time.
Abstract Background Advanced footwear technologies (AFT) are popular for their potential performance benefits, though concerns about injury risks persist. Among various AFT features, sole thickness is particularly debated, especially after World Athletics imposed a 40 mm limit to prevent unfair competitive advantages. However, the effects of sole thickness on running biomechanics and economy are not well understood, particularly because sole thickness often co-varies with other shoe characteristics in shoe designs. Objective This review examines the effects of sole thickness on spatiotemporal variables, kinematics, kinetics, and running economy. The review focuses on studies in which sole thickness was the primary variable of interest. Methods A systematic literature search was conducted following PRISMA guidelines. Eligible studies included original research on running with participants of all expertise levels, analyzing spatiotemporal variables, kinematics, kinetics, or running economy. Results Fourteen studies met the criteria, mostly focusing on male recreational or experienced runners. Thicker soles were linked to increased stance time, while other spatiotemporal parameters remained unchanged. Significant effects were seen in ankle kinematics, with more dorsiflexion at initial contact with thicker soles, though knee and hip movements were less affected. Thicker soles increased peak eversion in the frontal plane. No consistent trends emerged for joint kinetics, stiffness, or center of mass movement. Vertical ground reaction force (GRF) peaks remained largely unchanged, but loading rates generally decreased with thicker soles. Only one study assessed running economy, with no significant effects. Overall, the certainty of evidence across outcomes was low to very low due to methodological heterogeneity and limited study numbers. Conclusions Thicker soles were largely linked to longer stance times and lower GRF loading rates. Future research should comprehensively report shoe characteristics, include more diverse populations (e.g., female runners, forefoot strikers), and expand investigations to underexplored aspects such as muscle activity and movement coordination.
