Highlights • Classical Taylor model proves inadequate for strain prediction. • Micromechanical Taylor Factor outperforms in capturing local effects. • Work-hardening models improve with Micromechanical Taylor Factor. • Different insights into dislocation mechanisms using refined approach. • Potential to revolutionize materials design with greater precision. This study uses Fast Fourier Transform (FFT) simulations in the Düsseldorf Advanced Material Simulation Kit (DAMASK) to investigate the influence of the micromechanical Taylor Factor on the work hardening parameters. Departing from the assumption of a homogeneous deformation in the classical Taylor model, we use the micromechanical Taylor Factor, which takes better account of local grain interactions and strain distributions. Our comparison of simulations using both classical and micromechanical Taylor factors reveal crucial differences in the predicted dislocation mechanisms, leading to different interpretations of work hardening behavior. Our results question the adequacy of conventional models and suggest a more sophisticated understanding of the deformation of polycrystalline materials. The study underscores the importance of an improved modeling approach to characterize deformation and leads to a re-assessment of existing predictive mechanisms in materials science with possible implications for optimizing of material performance. Graphical abstract Download : Download high-res image (259KB) Download : Download full-size image
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By employing atomic material properties (i.e., elastic moduli and general stacking fault energy (GSFE)) of Ni3Al with L12 structure, we predict a series of core configurations of dislocations with edge and screw characters associated with slip systems of ( 1 1 1 ) 0 1 1 ¯ and ( 0 0 1 ) 1 1 0 under various external applied stresses. For the slip system of ( 1 1 1 ) 0 1 1 ¯ , the dislocation cores are found to consist of one APB and two CSF faults, with a larger core for the edge dislocation than for the screw. Such multi faults core configuration is missing for the ( 0 0 1 ) 1 1 0 slip system, where only a larger APB fault is present due to a lower APB energy on ( 0 0 1 ) as compared with that on ( 1 1 1 ) . The dissociation mechanism for full dislocations into super partials and possible faults under different applied shear stresses are carefully investigated. It is found that the core structures (including APB, CSF and SISF faults) exhibit different degrees of dependence on the direction and magnitude of the applied stresses. The evolution of local displacements exhibits a specific sequence of “full dislocation → SISF → APB”, which can be modulated by the variation of stresses. Graphical abstract Download : Download high-res image (163KB) Download : Download full-size image
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Highlights • This study analyses the stability of COFs at 37 °C and 42 °C and their impact on the binding and interaction energies with DOX. • vdW interactions contribute most to DOX-COF binding energy, while ES and HB interactions were negligible. • The COFs with small polar or non-polar substitutions were unsuitable for DOX release. • COF-HQ with bulky substitution having the highest binding energy, and placement of DOX between the COF substitution layers impeded the temperature effect to release DOX. • DOX release was observed only in COF-OMe at the higher temperature of 42 °C. Nowadays, drug release through temperature control between healthy and cancer cells is also one of the most critical topics in drug delivery. Covalent organic frameworks (COFs) with specific structural units and functional groups can be optimized for efficient smart drug delivery applications. Hence, in the present study, a detailed systematic study on the release of the anticancer drug doxorubicin (DOX) in a temperature-sensitive method from COFs with structural units of 1,3,5-tris(4-aminophenyl)benzene and terephthalaldehyde substituted with hydrogen (COF-H), ethyl (COF-Et), hydroxyl (COF-OH), methoxy (COF-OMe) and 8-hydroxyquinoline (COF-HQ), by molecular dynamics (MD) simulation method at two temperatures of 37 °C and 42 °C was performed. In addition to the stability of COF systems at 37 °C and 42 °C, the results showed that changing the temperature and substitution effectively changes the binding and interaction energies between the DOX and COFs. It was understood that van der Waals (vdW) interactions, in contrast to electrostatic (ES) interactions, have the major contribution to the binding energy ( Δ G bind ° ). Also, hydrogen bonding (HB) can be effective in binding between the DOX and COFs capable of donating and accepting HBs, such as COF-HQ and COF-OH. It was seen that COFs with completely polar substitution (COF-OH) or completely non-polar substitution (COF-Et and COF-H) were unsuitable, because the DOX establishes strong interactions with these COFs by being placed on the inner surface of the cavities of the COF backbone. Also, COF with bulky substitution, COF-HQ, has the highest Δ G bind ° = −45.9108, but it was observed, due to the gradual placement of the DOX between the COF substitution layers, increasing the temperature was not able to release the DOX. Finally, DOX release was observed among the five COF systems in COF-OMe at 42 °C ( Δ G bind ° = −21.0080 kcal/mol). But at 37 °C, due to the absorption of the DOX inside COF-OMe cavities ( Δ G bind ° = −30.9486 kcal/mol), DOX release was not observed. Graphical abstract Download : Download high-res image (188KB) Download : Download full-size image
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