Abstract: Surface retarder compositions of the invention comprise at least one surface retarder active suspended in a vegatable oil or derivative thereof, an animal oil or derivative thereof, or mixtures thereof. Methods involving use of the compositions are also described.

Abstract: The invention relates to a modem and a method for providing bit loading computation in a multi-carrier communication system, using a plurality of simultaneous different carriers or tones by measuring the signal to noise ratios (SNRs) for carriers and by determining in dependence of the SNR a related number of bits to be allocated to the respective carrier. The method comprises the steps of providing a sliding window having a frequency width able to contain a predetermined number of the carriers, moving the sliding window over the frequency spectrum of the carriers through a plurality of positions of the window with respect to the carrier frequencies, and when the window contains the predetermined number of the carriers and there is at least one further carrier to be positioned in the window as a new carrier for bit allocation, the window is moved such that on entering a new carrier into the window at one of its borders, a carrier already in the window at the other frequency border leaves the window.

Abstract: An integrated modem circuits comprising processor-systems (1) and hardware (2,3) for exchanging signals with another modem circuit 1 Mb/s or more are provided with low cost, accurate, flexible filter software (11) for embodying a digital phase locked loop filter. Said hardware (2,3) comprises fast modules (22,32) for compensating for sample processing. The insight of hardware phase locked loops being expensive, not accurate, inflexible and of software phase locked loops being slow results in the basic idea of the phase locked loop calculations being done in software and the compensations being done in hardware. Sample software (14,15) processes samples (shifting-adding-deleting). Said hardware (2,3) comprises in the transmission path (2) mappers (21), rotors (22) and inverse Fourier transformators (23) and in the receiving path (3) Fourier transformators (33), rotors (32) and demappers (31). Control software (12,13) controls said rotors (22,32).

Abstract: The invention relates to a method to synchronise a multi-carrier transmission system wherein a time misalignment between a transmitter and a receiver is determined through an average of at least two pilot tones phase errors (Øi) weighted in accordance with the noise affecting each pilot tone transmission. Such method is characterised in that, when the noise affecting a pilot tone (38, 40) reaches a predetermined level, the pilot tone function is reallocated from this pilot tone (38, 40) to another carrier (42, 44) and/or this pilot tone weight is reduced.

Abstract: The invention relates to a modem and a method for providing bit loading computation in a multi-carrier communication system, using a plurality of simultaneous different carriers or tones by measuring the signal to noise ratios (SNRs) for carriers and by determining in dependence of the SNR a related number of bits to be allocated to the respective carrier. The method comprises the steps of providing a sliding window having a frequency width able to contain a predetermined number of the carriers, moving the sliding window over the frequency spectrum of the carriers through a plurality of positions of the window with respect to the carrier frequencies, and when the window contains the predetermined number of the carriers and there is at least one further carrier to be positioned in the window as a new carrier for bit allocation, the window is moved such that on entering a new carrier into the window at one of its borders, a carrier already in the window at the other frequency border leaves the window.

Abstract: A multi-carrier receiver selects antennas (A31, A32), i.e. carriers whereto a small amount of power and data is allocated, for estimation of characteristics of a narrowband disturber (RFI-Signal-3) in the Radio Frequency Interference band (RFI-Band), a predetermined band for e.g. radio amateur transmission. These antennas (A31, A32) can be selected amongst all carriers located inside the Radio Frequency Interference band (RFI-Band) and at least two carriers (C1, C2) located outside the Radio Frequency Interference band (RFI-Band).

Abstract: To generate a pseudo-random sequence (PRMS1) of multi-carrier data symbols (DMT0, DMT1, DMT2), a pseudo-random bit sequence (PRBS1) is produced by repetitively generating a pseudo-random sequence of L bits, L being a first integer value (L=4). To create a multi-carrier data symbol (DMT0, DMT1, DMT2) N bits are used, N being a second integer value (N=8). The pseudo-random bit sequence (PRBS1) is subdivided into strings of N′ bits, N′ being a third integer value larger than N (N′=9), and N bits out of each string of N′ bits are used to generate a respective multi-carrier data symbol (DMT0, DMT1, DMT2). N′−N bits out of each string of N′ bits are left unused.

Abstract: The invention concerns a composition useful for providing temporary protection against corrosion to metal surfaces comprising an oil-in-water emulsion characterised in that said emulsion contains in its aqueous phase at least a compound of general formula (I) in which the groups R, R1 and R2 represent independently of one another a hydrogen atom, a C1-C20 alkyl group, a C1-C20 halogenoalkyl group with the halogen being chlorine, bromine, iodine or fluorine, a C3-C6 cycloalkyl group, a carboxylic function or a C1-C6 carboxyalkyl group; n is a whole number varying from 1 to 3; and X represents an oxygen or sulphur atom in the form of one of its soluble salts. The invention also concerns a method for preparing said composition, its method of application to the surface of metal part and the resulting part.

Abstract: In a multi-carrier system, the carriers (f0 . . . f511, f512 . . . f1023, . . . , f3584 . . . f4095) are grouped in subsets (SUBSET1; SUBSET2; . . . ; SUBSET8). A constellation information transmitting arrangement (BiGi_TA), for instance located in the multi-carrier receiver (RX), produces for each carrier subset (SUBSET1; SUBSET2; . . . ; SUBSET8) a limited set of parameter values (B1, G1; B2, G2; . . . ; BG8) and transmits these sets of parameter values (B1, G1; B2, G2; . . . ; B8, G8) to a constellation information receiving arrangement (BiGi_RA), for instance located in the multi-carrier transmitter (TX). Through interpolation of the limited set of parameter values (BG1; B2, G2; . . . ; BG8) the latter constellation information receiving arrangement (BiGi_RA) determines the constellation where each carrier (f0 . . . f511, f512 . . . f1023, . . . , f3584 . . . f4095) of a carrier subset (SUBSET1; SUBSET2;. . . ; SUBSET8) will be modulated with.

Abstract: The invention relates to a process for producing organized powders. The powder comprises a set of core particles and a set of satellite particles. To form the organized powders, a substantially homogenous dispersion of each set is made in a dispersing liquid; the resultant dispersion is then sprayed in suitable conditions to form the organized powder. The organized powders obtained are characterized by a very uniform covering of the core particles regardless of their shape.

Abstract: The process is characterised according to the invention by the application to the metal surface, especially sheet metal, of a layer of a solution comprising a block copolymer made up of at least two blocks, the first consisting of a unit based on a siloxane monomer and the second consisting of a unit based on acrylic or vinyl monomers.

Abstract: The present invention relates to new conductive perovskites containing oxygen and nitrogen, their preparation and their use particularly as electrode material.The conductive perovskites containing oxygen and nitrogen according to the invention correspond to the general formula IAB(O,N).sub.3 (I)in the cationic lattice of which:A denotes a metal chosen from the metals of groups IA and IIA, yttrium and the lanthanides,B denotes a metal chosen from the transition metals of groups IVA to IB,on the express condition that at least one of the metals A and B is present in an oxidation state other than its normal maximum oxidation state.