our plans are up in the air→ nuestros planes están en el aireto be walking or floating on air→ no caber en sí de alegríasee also breath A2see also change A1see also clear D1see also hot Dsee also thin A92. (Rad, TV)off air...
During the lockdown, the distance rules can usually be adhered to, but what happens when the actual lockdown is over and the people meet again in a confined space? Then additional effective and efficient protection is essential to stabilize infection rates. Since the viruses are spread by ...
Similarity theory is based on the organization of variables into dimensionless groups. The complex nature of these groups has a deep physical meaning, reflecting the interaction of various effects. The basic rules for the analysis of dimensionality and similarity have been reported in [25,26,27]....