Abstract: Two-component fibers, having surface area of at least 1 m.sup.2 /g, suited for replacing cellulose fibers in the manufacture of paper and paper-like products comprise a core of olefinic polymer and from 2 to 50% by weight of a sheath of a hydrophilic polymer, and exhibit values of the tenacity higher than 3,000 meters and cohesion higher than 300 meters. They are prepared by extruding a stable emulsion formed by a mixture of a solution of the olefinic polymer with a solution of the hydrophilic polymer in reciprocally immiscible solvents, at a temperature exceeding the boiling temperature of the solvent of the olefinic polymer and at least equal to the dissolution temperature of such polymer in such solvent, in a medium at a lower pressure, by using a volume ratio of solvent for the olefinic polymer to solvent for the hydrophilic polymer of at least 2.5 and concentrations of hydrophilic polymer in its solution of at least 2 g/l of solvent.

Abstract: Apparatus for producing a graph of a function represented by a varying analogue input signal supplied to the apparatus, comprising display means adapted to display in a graphing operation the graph of the function, calculating means adapted to receive the analogue input signal and to calculate the value of a parameter of the function, and control means operable to interrupt the operation of the display means at preselected points in the graphing operation and to cause the display means to display the value calculated by the calculating means and thereafter to resume the graphing operation.

Abstract: Computing apparatus for producing a digital output equal to ##EQU1## where N.sub.1 is a preset digital factor and V.sub.1 and V.sub.2 are analogue input signals. The apparatus includes a pulse generator arranged to receive in turn each of the signals V.sub.1 and V.sub.2 and to generate pulses at a frequency proportional to the magnitude of the signal, a counter for counting pulses received from the generator, timing means for measuring the time T taken for the count in the counter to reach the value N.sub.1 when signal V.sub.1 is applied to the pulse generator, means for resetting the counter, and means for extracting the count in the counter after a time equal to time T has elapsed during a counting operation with signal V.sub.2 applied to the pulse generator.