Abstract: A recording sheet for ink jet printing is described, which consists of a paper support having coated on the front side of the support at least one ink-receiving layer consisting of fumed silicon dioxide with a positively charged surface and at least one binder, wherein at least one polyolefin layer is coated at the back side of said support and where there is no polyolefin layer between said paper support and the ink-receiving layer. Preferred is a recording sheet, wherein the surface of the fumed silicon dioxide has been modified by a treatment with the reaction products of a compound of trivalent aluminum with at least one aminoorganosilane.

Abstract: A recording sheet for ink jet printing is described, which consists of a paper support having coated on the front side of the support at least one ink-receiving layer consisting of fumed silicon dioxide with a positively charged surface and at least one binder, wherein at least one polyolefin layer is coated at the back side of said support and where there is no polyolefin layer between said paper support and the ink-receiving layer. Preferred is a recording sheet, wherein the surface of the fumed silicon dioxide has been modified by a treatment with the reaction products of a compound of trivalent aluminum with at least one aminoorganosilane.

Abstract: The apparatus is comprised of two sensors of the thermal type (11a, 11b) made of materials resisting without any alteration to a temperature of 650.degree. C. Probes (15a, 15b) are controlled by a microprocessor (16) to come periodically and momentarily in contact with the sensors in order to calculate (through microprocessor (16)) the thermal time constant of the sensors presenting a deposition layer of environmental polutants. The microprocessor (16) compares the value of the time constant with an order value that commands the closure of a shunt switch (17) of a resistance (18) which, when short-circuited, determines a reinforced heating of the sensors to bring them to a temperature of incineration of organic materials originating from the pollution of the ambient medium and deposited on said sensors. Thus, the sensors are maintained in the cleanliness conditions of their surface, thereby providing for the accuracy of information supplied by the sensors outside cleaning periods.

Abstract: The device consists of a permanent module (10) and a removable cassette (11). The permanent module comprises a housing (12) with control keys (13) and physical value indicators (14), and two drive hubs (20, 21) for driving two peristaltic pumps mounted in a cassette. The inlet duct (15) of the first pump is connected to a container of physiological liquid, the outlet duct (16) of this pump supplies said liquid to the operating zone, and the duct (17) of the second pump is connected to an operating instrument to drain off the liquid, the duct (18) of this second pump being coupled with a drainage circuit.