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Ion-irradiation-induced hardening is investigated on six selected reactor pressure vessel (RPV) steels. The steels were irradiated with 5 MeV Fe2+ions at fluences ranging from 0.01 to 1.0 displacements per atom (dpa) and the induced hardening of the surface layer was probed with nanoindentation. To separate the indentation size effect and the substrate effect from the irradiation-induced hardness profile, we developed an analytic model with the plastic zone of the indentation approximated as a half sphere. This model allows the actual hardness profile to be retrieved and the measured hardness increase to be assigned to the respective fluence. The obtained values of hardness increase vs. fluence are compared for selected pairs of samples in order to extract effects of the RPV steel composition. We identify hardening effects due to increased levels of copper, manganese-nickel and phosphorous. Further comparison with available neutron-irradiated conditions of the same heats of RPV steels indicates pronounced differences of the considered effects of composition for irradiation with neutrons vs. ions. [ABSTRACT FROM AUTHOR]

BACKGROUND: hip fracture is a major cause of morbidity and mortality in older people; optimal post-surgical treatment is a matter of controversy. OBJECTIVE:to examine the effects of rehabilitation on the clinical outcome following surgical treatment of hip fracture. DESIGN: prospective longitudinal study in three groups of patients with different post-surgical care. METHODS: initial screening of 283 elderly patients with proximal femur fracture; documentation of medical and social history and clinical data; geriatric assessments (Activities of Daily Living and Instrumental Activities of Daily Living) during hospital stay and follow-up for 12 months. One hundred and forty-five patients (>or=65 years) of normal mental status were eligible for the study. Successful follow-up could be monitored in 120 and 117 patients for 6 and 12 months, respectively. Sixty-nine and 39 patients underwent supervised inpatient rehabilitation in an orthopaedic or geriatric hospital, respectively (intervention groups A and B, respectively) whereas 34 patients received no special rehabilitation as they were directly discharged home (control group C). RESULTS: initially a fall-/surgical-induced reduction (P<0.001) of the main outcome measure (Activities of Daily Living) was observed in all patients. Within 6 months of rehabilitation there was an improvement (P<0.01) in Activities of Daily Living; however the pre-fracture scores were not reached. The same time pattern was seen in group C. Therefore no significant differences between the three groups of patients in approaching the baseline status was visible. Moreover, the one-year total mortality in the studied population with normal mental status averaged 11.7% and did not differ between the three groups. CONCLUSION: based on our measured outcome variables institutional rehabilitation after surgical treatment of hip fracture apparently had no significant impact on mortality and morbidity in older patients of normal mental status. [ABSTRACT FROM AUTHOR]

In this work, neural ordinary differential equations (NODE) are used to identify phenomenological growth rate functions to model the solid electrolyte interphase (SEI) growth during formation. To analyse the capabilities of this approach in a controlled setting, synthetic SEI thickness data is generated using a model that uses a mechanistic growth rate function. Several possible implementations and extensions of the NODE are investigated, including physical constraints and data augmentation. All the investigated variants agree well with the training data, but significant differences are observed for the validation data. The results show that the growth rate functions learnt by the baseline implementation without further constraints significantly differs from the growth rate function given by the mechanistic model. However, it is shown that the use of appropriate data augmentation or physical constraints provides a significant improvement, and low errors can be achieved within the validation data sets. It is concluded that NODE can reveal growth rate functions, but careful consideration is needed to achieve functions that are phenomenologically consistent with the underlying mechanisms. [ABSTRACT FROM AUTHOR]

Highlights: [•] Electron holographic tomography provides a unique access to 3D electric potential at the nanometer scale. [•] It has been successfully applied to reveal the 3D potential in nanowires and across p–n junctions in semiconductors. [•] The prospects of the 3D reconstruction of magnetic vector fields as well as atomic crystal potentials are discussed. [ABSTRACT FROM AUTHOR]

Electron holography at medium resolution simultaneously probes projected electrostatic and magnetostatic potentials as well as elastic and inelastic attenuation coefficients with a spatial resolution of a few nanometers. In this work, we derive how the elastic and inelastic attenuation can be disentangled. Using that result, we perform the first three dimensional tomographic reconstruction of potential and (in)elastic attenuation in parallel. The technique can be applied to distinguish between functional potentials and composition changes in nanostructures, as demonstrated using the example of a GaAs--Al0.33Ga0.67As core-shell nanowire. [ABSTRACT FROM AUTHOR]

Safety considerations have always accompanied the development of new battery chemistries; this holds especially for the Li-ion battery with its highly reactive components. An overall assessment and decrease of risks of catastrophic failures such as during thermal runaway, requires an in-depth and quantitative understanding of the ongoing processes and their interaction. This can be provided by predictive mathematical models. Thus, we developed a thermal runaway model that focuses on rigorous modelling of thermodynamic properties and reactions of each component within a Li-ion battery. Moreover, the presented model considers vapour–liquid equilibria of a binary solvent mixture for the first time. Simulations show a fragile equilibrium between endothermic and exothermic reactions, such as LiPF 6 and LEDC decomposition, in the early phases of self-heating. Further, an autocatalytic cycle involving the production of HF and the SEI component Li 2 CO 3 could be revealed. Additionally, the unpredictability of the thermal runaway could be directly correlated to availability of LEDC or contaminants such as water. Also, solvent boiling can have a significant influence on the self-heating phase of a Li-ion battery, due to its endothermic nature. Further analysis revealed that the rising pressure, stemming from gassing reactions, can suppress solvent boiling until the thermal runaway occurs. [Display omitted] • First time consideration of phase equilibria in Li-ion battery thermal runaway. • Complex interaction of SEI degradation, reformation and solvent boiling revealed. • Fragile equilibrium of endo- and exothermic processes in self-heating phase. • Unpredictability of thermal runaway related to presence of LEDC or water. • Rising pressure from reaction gases can suppress solvent boiling. [ABSTRACT FROM AUTHOR]