Iskanje po katalogu digitalne knjižnice

Opis: In additive manufacturing, tooling is frequently built from laminated metal composites (LMCs) that stack dissimilar metals to shorten production times. Accurately predicting fatigue-crack growth in these unequal-strength laminates is difficult—particularly across joints where property mismatches steer crack paths. This work combines experiments and simulations to study fatigue-crack growth in an LMC formed by laser-melting AISI 316L powder onto high-strength structural steel S960. Crack growth was modeled with a linearized bond-based peridynamics (PD) formulation, with interfacial bonds tuned to the measured elastic-modulus gradient, and coupled to the Kinetic Theory of Fracture (KTF). Unlike conventional S–N–based approaches, KTF parameters were calibrated directly from measured crack-length–versus-cycles (a-N) data. Material behavior in the base metals and through the transition zone was characterized via tensile tests, hardness mapping, and nanoindentation; fatigue-crack growth data came from cyclic tests on compact-tension (CT) specimens. The model reproduced the observed differences in crack-growth rates between homogeneous and bimaterial specimens, and KTF parameter transferability across loads and geometries was confirmed for homogeneous samples. A key outcome is a practical calibration workflow for KTF within a nonlocal PD framework, enabling predictive simulation of fatigue-crack growth across multilayer metallic joints.
Ključne besede: Peridynamics, Fatigue Crack Growth, Kinetic Theory of Fracture, Layered Metal Composite, Additive Manufacturing
Objavljeno v DKUM: 13.01.2026; Ogledov: 0; Prenosov: 11
Celotno besedilo (13,30 MB)

Opis: Fluidized bed systems are widely used in chemical and process engineering due to their excellent heat and mass transfer properties. Numerical modeling plays a crucial role in understanding and optimizing these systems, with the two-fluid model enhanced by the kinetic theory of granular flow (TFM-KTGF) and the coupled computational fluid dynamics-discrete element method (CFD-DEM) emerging as leading techniques. This study employs both models to simulate gas-solid interactions and evaluates their performance using a benchmark single-spout fluidized bed case validated against experimental data. Subsequently, the influence of particle presence on gas flow distribution through a non-uniform distribution plate is analyzed. The results show that the common assumption of proportional flow distribution based on the opening area fraction is inaccurate, particularly in the presence of particles. Both numerical models capture this behavior, with TFM-KTGF showing trends comparable to the coupled CFD-DEM approach but at significantly reduced computational cost. The findings highlight the importance of accounting for particle dynamics in distribution plate design and promote the TFM-KTGF approach as a promising alternative for large-scale simulations.
Ključne besede: fluidized bed, distribution plate, two-fluid model with kinetic theory of granular flow, coupled CFD-DEM, flow distribution
Objavljeno v DKUM: 09.12.2025; Ogledov: 0; Prenosov: 7
Celotno besedilo (2,16 MB)
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Opis: The stringy realization of generalized symmetry operators involves wrapping “branes at infinity”. We argue that in the case of continuous (as opposed to discrete) symmetries, the appropriate objects are fluxbranes. We use this perspective to revisit the phase structure of Verlinde’s monopole, a proposed particle satisfies the Bogomol'nyi-Prasad-Sommerfield (BPS) condition when gravity is decoupled, but is non-BPS and metastable when gravity is switched on. Geometrically, this monopole is obtained from branes wrapped on locally stable but globally trivial cycles of a compactification geometry. The fluxbrane picture allows us to characterize electric (respectively magnetic) confinement (respectively screening) in the 4D theory as a result of monopole decay. In the presence of the fluxbrane, this decay also creates lower-dimensional fluxbranes, which in the field theory is interpreted as the creation of an additional topological field theory sector.
Ključne besede: quantum gravity, 4D theory, fluxbranes, generalized symmetries, Verlinde’s metastable monopole
Objavljeno v DKUM: 11.11.2025; Ogledov: 0; Prenosov: 2
Celotno besedilo (371,70 KB)
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Opis: Background: Evolutionary game theory (EGT), originating from Darwinian competition studies, offers a powerful framework for understanding complex healthcare interactions where multiple stakeholders with conflicting interests evolve strategies over time. Unlike traditional game theory, EGT accounts for bounded rationality and strategic evolution through imitation and selection. Aims and objectives: In our study, we use Synthetic Knowledge Synthesis (SKS) that integrates descriptive bibliometrics and bibliometric mapping to systematically analyze the application of EGT in healthcare. The SKS aimed to identify prolific research topics, suitable publishing venues, and productive institutions/countries for collaboration and funding. Data was harvested from the Scopus bibliographic database, encompassing 539 publications from 2000 to June 2025, Results: Production dynamics is revealing an exponential growth in scholarly output since 2019, with peak productivity in 2024. Descriptive bibliometrics showed China as the most prolific country (376 publications), followed by the United States and the United Kingdom. Key institutions are predominantly Chinese, and top journals include PLoS One and Frontiers in Public Health. Funding is primarily from Chinese entities like the National Natural Science Foundation of China. Bibliometric mapping identified five key research themes: game theory in cancer research, evolution game-based simulation of supply management, evolutionary game theory in epidemics, evolutionary games in trustworthy connected public health, and evolutionary games in collaborative governance. Conclusions: Despite EGT’s utility, significant research gaps exist in methodological robustness, data availability, contextual modelling, and interdisciplinary translation. Future research should focus on integrating machine learning, longitudinal data, and explicit ethical frameworks to enhance EGT’s practical application in adaptive, patient-centred healthcare systems
Ključne besede: evolutionary games theory, healthcare, complex healthcare systems, synthetic knowledge synthesis, thematic analysis
Objavljeno v DKUM: 29.10.2025; Ogledov: 0; Prenosov: 5
Celotno besedilo (587,94 KB)

Opis: Despite their potential for promoting environmental sustainability, understanding consumer adoption of green products is limited since such behavior is complex, as it may differ from typical purchasing motives and cultural values. Theory of Planned Behavior (TPB) was used in this study to address the main research problem of how PBC attitudes, subjective norms, environmental (un)concern, and environmental knowledge, influence consumers’ green product purchase intention. It also explores how cultural values moderate these relationships, specifically man-nature orientation and LTO. This study proposes a structural model with multigroup analysis to address the moderating impacts on a sample of 216 respondents participating in an online survey. Results show that attitude, subjective norms, perceived behavioral control, and environmental knowledge positively influence consumers’ green product purchase intention. The group analysis results imply that the dominant group’s environmental concern negatively impacts purchase intention, while this relationship is not significant in the subordinate group. Also, the influence of subjective norms on purchase intention is significantly stronger in the dominant group. The long-term orientation also moderates the relationship between attitude toward green products and purchase intention. The insights from this research extend the literature in TPB and provide practical implications to marketing managers concerning developing marketing communication strategies, perceived value proposals, and the reputation of green products.
Ključne besede: theory of planned behavior, man-nature orientation, green products, long-term orientation, purchase intention
Objavljeno v DKUM: 01.10.2025; Ogledov: 0; Prenosov: 9
Celotno besedilo (405,01 KB)
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