Null space-based control with gain modulation applied to a MARV in backward movement.

A controller is proposed to guide a multi-articulated robot vehicle (MARV) moving backwards, following a certain path. The ability to avoid fixed and moving obstacles is included, using the null space-based control technique to manage the conflicting tasks of following a path and avoiding obstacles. Additionally, control gains are modulated, thus reducing the risk of jackknifing.

Structure-activity relationships in N1-acetylderivatives of sulpha drugs.

The N1-acetylderivatives (ASA) of sulphanylamides (SA) were prepared and their stability to hydrolysis was evaluated together with the spectroscopic and antibacteric activity parameters, with the aim both of obtaining electronic structure-activity relationships and of comparing these results with those previously found for SA. From our results it appears that: a) the stability to hydrolysis is dramatically reduced on passing from the aqueous medium (pH 7) to the culture broth, and that b) in general, the ASA examined do not show any greater antibacterial activity with respect to the parent compounds, as suggested by the values of the spectroscopic indices-taken as experimental electronic indices. This result is in full agreement with the structure-activity relationships previously proposed fo the sulpha drugs.