136 research outputs found
Fatigue assessment of steel rollers by means of the local energy
This paper aims to analyses the fatigue behavior of steel rollers using the average strain energy density (SED) criterion. Considering the variability of the V-notch opening angle, a simple scalar quantity, i.e. the value of the strain energy density averaged in a control volume surrounding the notch tip, has been introduced to overcome the complexities in failure assessment of this component. The strain energy is obtained using close form solutions based on the relevant Notch Stress Intensity Factors (NSIF) for modes I, II and III. Referring to the conventional arc welding processes, the radius of the control volume is carefully identified with reference to conventional arc welding processes being equal to 0.28 mm for welded joints made of steel. In this paper firstly the employed methodology for the fatigue assessment is described and then the first synthesis of fatigue data by means of local SED for a specific geometry is shown
Direct and cross-scheme effects in a research and development subsidy program
This study investigates the effects of an R&D subsidy scheme on participating firms’ net R&D
investment. Making use of a specific policy design in Belgium that explicitly distinguishes
between research and development grants, we estimate direct and cross-scheme effects on research
versus development intensities in recipients firms. We find positive direct effects from research
(development) subsidies on net research (development) spending. This direct effect is larger for
research grants than for development grants. We also find cross-scheme effects that may arise due
to complementarity between research and development activities. Finally, we find that the
magnitude of the treatment effects depends on firm size and age and that there is a minimum
effective grant size, especially for research projects. The results support the view that public
subsidies induce higher additional investment particularly in research where market failures are
larger, even when the subsidies are targeting development
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