This device for displaying time periods comprises a display element, an indicator component, a drive component for driving the indicator component, an instantaneous-jump cam engaged with the drive component, a drive mobile for driving the cam and correction means for coming into direct engagement with the indicator component. Respective position coordinates of the particles on the surface are determined. Each target user may instantly retrieve a message by using a smart notification provided by the IVM server. Radionuclides may be removed using volcanic ash alone or in combination with chitin or chitosan. The motor selector compares a detection signal of a steering torque detector of a boat with the motor characteristic data and the correction data in order to select at least one of the steering motors to be operated. The multi-sample pixel data is received and is analyzed to identify subsets of samples of a multi-sample pixel that have equal data, such that data for one sample in a subset represents multi-sample pixel data for all samples in the subset.