The phase-field approach to dislocations is conceptually advanced. Large strain formulation is developed. A local thermodynamic potential eliminates stress dependence of the Burgers vector and reproduces the desired local stress-strain curve, as well as the desired, mesh-independent, dislocation height for any dislocation orientation. A gradient energy contains an additional term, which exclude...

TaC and HfC are thought to have the highest melting point (~4000°C) among all refractory materials. The binary solid solution of TaC and HfC (Ta4HfC5) is also considered as the most refractory material with the melting point over 4000 °C and valuable physical and mechanical properties. The main goal of this work is to fabricate TaC/HfCbased composites which consolidated by means of spark plasma...

We reconsider the Eigen’s quasi-species model for competing self-reproductive macromolecules in populations characterized by a single-peaked fitness landscape. The use of ideas and tools borrowed from polymers theory and statistical mechanics, allows us to exactly solve the model for generic DNA lengths d. The mathematical shape of the quasi-species confined around the master sequence is pertur...

Evolution in changing environments is an important, but little studied aspect of the theory of evolution. The idea of adaptive walks in fitness landscapes has triggered a vast amount of research and has led to many important insights about the progress of evolution. Nevertheless, the small step to time-dependent fitness landscapes has most of the time not been taken. In this work, some elements...

the pseudo-elastic behavior of shape memory alloy (sma) truss and cantilever beam are investigated. brinson’s one-dimensional material model, which uses the twinned and detwinned martensite fractions separately as internal variables, is applied in the algorithm to establish the sma stress-strain characteristics. this material model also incorporates different young’s modulus for austenitic and ...

In a previous work, the authors proposed a Grammatical Evolution algorithm to automatically generate Lindenmayer Systems which represent fractal curves with a pre-determined fractal dimension. This paper gives strong statistical evidence that the probability distributions of the execution time of that algorithm exhibits a heavy tail with an hyperbolic probability decay for long executions, whic...

We have evidence that the classical random pinning model , if simulated numerically using a phase evolution scheme pioneered by Littlewood , gives dispersion relationships that are inconsistent with experimental values near threshold. . These results argue for a revision of contemporary classical models of charge density wave transport phenomena. Classically, phase evolution equations are in es...