Abstract: The invention relates to compositions comprising:a) a 4-benzoylisoxazole of formula (I) wherein R, R.sup.1 and R.sup.2 are as defined in the description; andb) N-isopropyl-(5-trifluoromethyl-1,3,4-thiadiazol-2-yl)-4-(4'-fluoro-oxyacet anilide) having formula (II)and to their use as herbicides.

Abstract: The invention provides a method for checking the printing quality of an ink jet printer. A control frame is printed independently of a marking message. This frame is, for example, formed of 15 dots of which the charge increases from the first to the fifteenth droplet. The distance (G.sub.1, G.sub.2, G.sub.3) separating, respectively, the droplets (1) and (8), the droplets (8) and (15) and the droplets (1) and (15) are permanently maintained so as to correspond to the two relationships: G.sub.1 G.sub.3 =k.sub.1 and G.sub.2 /G.sub.2 =k.sub.2, where k.sub.1 and k.sub.2 are constants.

Abstract: This method consists in introducing a programmed defect at the writing level; the defect will be detected at the reading level by means of a key corresponding to the writing control algorithm which is known only to the user.

Abstract: The invention relates to a method for marking products in relation with an organization commissioned to check this marking both from the point of view of authenticity of the printed message and from the point of view of the number of these messages which have actually been printed. The printer (A) connected to the packaging chain (C) receives the control instructions either directly from a terminal (B) located in the premises of the checking organization or by means of a memory card programmed by this organization and supplied by this latter to the user. Recording of the number of messages is carried out either directly at the level of the terminal (B) on the premises of the checking party or by means of the memory card which contains a predetermined number of messages. When the card has been utilized, the user acquires another card. The invention applies in particular to checking of affixing of inland revenue stamps and makes it possible to guard against fraud in an effective manner.

Abstract: A printing head for equipping any printer of the continuous ink-jet type comprises a modulator element in which a body and an orientable cylindrical plate are incorporated in a modulator base. The orientable plate carries an ink-drop ejecting nozzle and is capable of optimizing the perpendicularity of the ink jet. The modulator element and an electrode-holder are rigidly fixed respectively to a casing and to a section of its cover which is pivotally mounted with respect to the modulator base. Slits formed in charging electrodes and charging-control electrodes can be positioned with respect to the axis of ejection of the ink jet.