Abstract: Next to a window opening (4) an inlet air pipe (14) and an exit air pipe (17) are arranged vertically a distance apart in an outer insulation (1), each of which connect an outer inlet air opening (15) and an outer exit air opening (18), respectively, to an inner inlet air opening (13) and an inner exit air opening (16), respectively, which are located in a depression (12) of a cladding (9) into which a fan (19) is inserted with a back. It connects the inner inlet air opening (13) via an inlet air channel to an inlet air outlet (21) and the inner exit air opening (16) via an exit air channel, which, together with the inlet air channel, forms a heat exchanger, to an exit air entrance (22). The exit air entrance (22) and the inlet air outlet (21) are arranged one on top of the other and a distance apart on the front of the fan (19). Instead of the fan (19), a closure plate (23) can also be inserted into the depression (12).

Abstract: Process for the preparation of tert-alkyl esters of the formula I ##STR1## in which m is 1 or 2, R is C.sub.4 -C.sub.12 tert-alkyl and X, if m=1, is unsubstituted or halogen-substituted alkyl, cycloalkyl, unsubstituted or substituted aryl or aralkyl, or an aromatic heterocyclic radical and, if m=2, is a direct bond, --CH.sub.2).sub.n, in which n can be an integer from 1 to 8, or 1,2-, 1,3- or 1,4-phenylene, by reaction of an ester of the formula II ##STR2## in which R.sub.1 is methyl or ethyl, with an alcohol ROH in the presence of a catalyst customary for transesterifications.

Abstract: A printer device for the individual feed of pre-printed sheets or tickets through a sheet guide channel to a printer platen of an associated printer comprises at least two sensors. The at least two sensors are connected to the inputs of a control processor which processes the electrical states of the sensors. The outputs LINE FEED and SELECT of this control processor are conducted to inputs of the SELECT and LINE FEED function input circuits of the associated printer. Commercially available printers can be converted into specialized printers for data recording or for filling in pre-printed forms without substantial modification by employing this device.