14 research outputs found
Retained austenite: transformation-induced plasticity
The deformation-induced phase transformation of metastable austenite to martensite is accompanied by macroscopic plastic strain and results in significant work hardening and the delayed onset of necking. Steels that exhibit such transformation-induced plasticity (TRIP) effect possess high strength-ductility ratios and improved toughness. Since the stability of the retained austenite (RA) phase is the rate controlling mechanism for the TRIP effect, the factors affecting the chemical and mechanical stability of RA in CMnSi TRIP steels are discussed. It was suggested that chemical stability plays a more important role at low strains, whereas other factors become responsible for RA behavior at higher strains. The importance of optimizing the processing parameters to achieve the desirable level of austenite stability is highlighted. Finally, the influence of mechanical testing conditions and the interaction between the phases during tensile testing are also detailed
Conventional Versus Alternative Pig Production Assessed By Multicriteria Decision Analysis
Differentiated quality and respect for the environment seem to be linked
implicitly, but there is no demonstration of this concept for pig
production. Pig production takes on different forms. Conventional pig
production occurs side by side with some productions of “differentiated
qualities” that are encouraged by the European Union as well as by nations.
At the same time, the EU and nations are imposing environmental limitations
concerning, for instance, the management of nitrogen and respect for
neighbours. Here, we compared environmental impacts of 3 types of
production: conventional production, organic production and free-range
production. We took into account the process performances of 21 farms in the
Walloon Region, Belgium. We compared the global process performances by
multicriteria analysis. A jury of 16 experts was questioned to assign a
relative importance to the emissions of ammonia, greenhouse gases, molecular
nitrogen, odour and nitrogen to effluents. We found that the highest
weighting was assigned to the N content of effluents, then to odour
diffusion, the emission of ammonia, the emissions of greenhouse gas and
finally, the emission of molecular nitrogen got a weak weighting. Our
results showed that the relative ordering obtained was: (1) free-range
production, (2) organic production and (3) conventional production.
Nevertheless, within every sample a significant variability in the
performances was observed. The same method applied within every sample
enabled the creation of sub-groups. After reordering, we found that the most
effective farms of every system of production were classified as top of the
class. Thus, our original approach showed that on average the production of
differentiated qualities was more environmentally effective than the
conventional production. However, the variability of the performances within
a system of production was high and it was quite possible for the
conventional farms to reach results comparable with those of the best
organic and free-range operations
DESHIMA 2.0: development of an integrated superconducting spectrometer for science-grade astronomical observations
Instrumentatio