Abstract: A semi-worked piece of composite material for producing artefacts/devices for dental and/or odontoiatric use such as posts and/or stumps and/or dental crowns for example, comprises a polymeric matrix and a multiplicity of mechanically resistant fibres nested in the polymeric matrix; in this semi-worked piece the resistant fibres are arranged in a predetermined number of reinforcing layers that are substantially planar and are disposed in mutually overlapped relationship.

Abstract: A radiotransmission station transmits digital data at a predetermined rate to a receiving station. The receiving station is controlled by a timing circuit which recognizes a predetermined enabling code. The digital data is transmitted as bit sequences and each sequence contains a first group of bits for synchronizing the timing circuit and the transmission rate. This first group of bits is followed by a second group of bits which includes the enabling code. The recognition of the enabling code enables the reviewing station to receive and process the transmitted information. The enabling code is derived from a sequence of logical "1" and "0" bits and certain bits of the sequence are altered to form groups of three like bits (111,000). Each group of three bits has no more than two adjacent pairs of like and opposite bits (00,11).

Abstract: The apparatus comprises an electronic teleprinter constituted by a first set of basic peripheral units such as the printer, keyboard etc. as well as a punch/reader, arranged to converse directly with the line and controlled by a first central unit, and a second set of peripheral units such as a disc unit, one line display and VDU controlled by a second CPU and able to execute more sophisticated operations such as the automatic filing of messages, their display etc. The two CPUs each autonomously control their own peripheral units with simultaneous processing, and periodically communicate with each other for the exchange of data and commands by way of an interface in an auxiliary unit. The CPU of the basic machine is thus free to handle the basic input/output procedures without having to service the auxiliary peripherals.

Abstract: The teleprinter is provided with a bialphabetic keyboard, for example latin and arabic, and a dot printing head controlled by two different character generating units corresponding to the two alphabets. The teleprinter is normally predisposed for one of the two alphabets and can be switched to the other alphabet by means of a sequence of characters. The arabic character generating unit is adapted to recognize predetermined sequences for generating composite characters, i.e. the lam-alef group. Furthermore, some characters at the end of a word are generated by adding a tail to the normal character in response to the spacing code. The teleprinter can be connected to the conventional existing teleprinters, since neither the composite characters, nor the tails are transmitted on the line.