A phase-field chemo-mechanical model for corrosion-induced cracking in reinforced concrete

We present a new mechanistic framework for corrosion-induced cracking in reinforced concrete that resolves the underlying chemo-mechanical processes. The framework combines, for the first time, (i) a model for reactive transport and precipitation of dissolved Fe2+ and Fe3+ ions in the concrete pore space, (ii) a precipitation eigenstrain model for the pressure caused by the accumulation of precipitates (rusts) under pore confinement conditions, (iii) a phase-field model calibrated for the quasi-brittle fracture behaviour of concrete, and (iv) a damage-dependent diffusivity tensor. Finite element model predictions show good agreement with experimental data from impressed current tests under natural-like corrosion current densities

Staphylococcal bacteremia in cancer patients: Risk factors and outcome in 134 episodes prior to and after introduction of quinolones into infection prevention in neutropenia

A total of 134 episodes of staphylococcal bacteremia (SBE) appearing among 9987 admissions, and 979 episodes of bacteremia in cancer patients within 5 years, were analyzed for risk factors, clinical course and outcome; 64 were monomicrobial and 70 polymicrobial. The most frequent risk factors were acute leukemia, catheter insertion, long-lasting neutropenia, and prior prophylaxis with quinolones. There was no significant difference between polymicrobial and monomicrobial SBE in risk factors. The two groups differed only in the source of bacteremia (gastrointestinal and respiratory-tract infections were more common in monomicrobial SBE) and etiology - Staphylococcus aureus appeared more frequently in monomicrobial than in polymicrobial bacteremia (20.3% compared to 4.3%, P<0.05). More complications (14.3%) such as abscesses, endocarditis, etc. appeared in the group of polymicrobial SBE (P<0.05). No difference was observed in clinical course and outcome between monomicrobial and polymicrobial SBE. The incidence of SBE has increased since 1991, when quinolones were first used in prophylaxis in afebrile neutropenia at our center; however, the infection-associated mortality in monomicrobial SBE was low (4.3%)

Construction of Some Nonautomatic Sequences by Cellular Automata

International audienceIt is known that if p is a prime number, the columns of linear CA are p-automatic sequences and all p-automatic sequences can be realized by some linear CA with memory. We give some constructions of (nonlinear) CA that realize certain nonautomatic sequences. First, we show through a recoding that from a construction with additional symbols, we can construct a CA using only the symbols occurring in the sequence. This answers a question posed by Rowland and Yassawi. Then, we propose a construction for the characteristic sequence of the integer polynomials, which are nonautomatic sequences by the Minsky–Papert criterion. We also provide a construction based on the indicator of Fibonacci numbers for the Fibonacci word, which is an emblematic nonautomatic sequence