Hydrogen-enhanced local plasticity in aluminum: an ab initio study

Dislocation core properties of Al with and without H impurities are studied using the Peierls-Nabarro model with parameters determined by ab initio calculations. We find that H not only facilitates dislocation emission from the crack tip but also enhances dislocation mobility dramatically, leading to macroscopically softening and thinning of the material ahead of the crack tip. We observe strong binding between H and dislocation cores, with the binding energy depending on dislocation character. This dependence can directly affect the mechanical properties of Al by inhibiting dislocation cross-slip and developing slip planarity.Comment: 4 pages, 3 figure

Semantics-preserving and memory-efficient implementation of inter-task communication on static-priority or EDF schedulers

In previous work, we have proposed a method of preserving the functional semantics of model-based designs by the use of static checks and a double-buffer protocol [12]. However, this is restricted to static, fixed-priority scheduling and for high-priority to low-priority communications requires a double buffer to be stored for each pair of communicating tasks. In this paper we extend the method to dynamic-priority scheduling in the form of earliest-deadlinefirst (EDF) scheduling and show that, although scheduling is dynamic, a static buffering scheme can still be used. We also suggest some memory optimizations of our protocol which still preserve the original functional semantics. Finally, we show how model checking can be used to prove correctness of the scheme

ABSTRACT Semantics-Preserving and Memory-Efficient Implementation of Inter-Task Communication on Static-Priority or EDF Schedulers ∗

In previous work, we have proposed a method of preserving the functional semantics of model-based designs by the use of static checks and a double-buffer protocol [12]. However, this is restricted to static, fixed-priority scheduling and for high-priority to low-priority communications requires a double buffer to be stored for each pair of communicating tasks. In this paper we extend the method to dynamic-priority scheduling in the form of earliest-deadlinefirst (EDF) scheduling and show that, although scheduling is dynamic, a static buffering scheme can still be used. We also suggest some memory optimizations of our protocol which still preserve the original functional semantics. Finally, we show how model checking can be used to prove correctness of the scheme