Abstract: An ordering indication device for use in restaurants, guest houses, hotels, catering companies, and the like, the ordering indication device including an input means, which can be operated by a guest, a communications interface, an optical indicator means, and a control unit, wherein the setting of the brightness of the one or more first light sources and the setting of the brightness of the one or more second light sources depend on an environmental condition, wherein the input means is operatively connected to the optical indicator means via the control unit such that the optical indicator means signals the activation process of the input means by means of an optical signal, following an activation of the optical indicator means by the input means, wherein the optical indicator means, following activation thereof, outputs an optical continuous signal, which can be deactivated.

Abstract: An ordering indication device for use in restaurants, guest houses, hotels, catering companies, and the like, the ordering indication device including an input means, which can be operated by a guest, a communications interface, an optical indicator means, and a control unit, wherein the setting of the brightness of the one or more first light sources and the setting of the brightness of the one or more second light sources depend on an environmental condition, wherein the input means is operatively connected to the optical indicator means via the control unit such that the optical indicator means signals the activation process of the input means by means of an optical signal, following an activation of the optical indicator means by the input means, wherein the optical indicator means, following activation thereof, outputs an optical continuous signal, which can be deactivated.

Abstract: A cavitation apparatus (CHRS) for use in subterranean drilling with a drilling rig, the rig having a drill bit and a drilling string mounted thereto through which a drilling fluid flows to the drill bit. The cavitation apparatus (CHRS) is adapted to be mounted in-line with the drilling string through which the drilling fluid flows. The CHRS has no moving parts and produces controlled low frequency, longitudinal fluctuations of at least a portion of a drill string to enhance the drilling rate of penetration (ROP). Optionally the entire drill string can be subjected to such controlled low frequency, longitudinal fluctuations.