This invention provides a method of combining an array-type nanospray ionization source comprising a set of externally wetted proud features and a contact electrode with a pneumatic nebuliser acting to enhance the flux of sprayed ions. Methods for producing a maize plant that comprise crossing maize variety PH128Z with another maize plant. The three-dimensional flip-flop postcard can actually be worn, albeit without a mate unless two are sent, either before or after a message and appropriate address information is written in applicable marking areas and it is mailed with sufficient postage or otherwise delivered to the intended recipient. The flat surface of the field lens is provided with a reference shape to place the polarizer at the end thereof. The radiation sensor arrangement has at least one radiation-sensitive element that has at least one circuit property which changes irreversibly when a radiation dose has exceeded a threshold value, thereby causing the radiation sensor arrangement to output a radiation detection signal.