摘要:
An exemplary method for set retarding the surface of a mortar or concrete material, comprising applying to the surface of a mortar or concrete, or to the inner surface of a mold for forming the mortar or concrete, a hot melt coating composition which is heated to assume a flowable or sprayable form, and allowing the hot melt coating composition to cool to ambient temperature whereby the composition forms a solidified membrane, and thereafter removing the membrane. Preferably, the hot melt coating composition contains at least one agent operative to retard the setting of the mortar or concrete, and optional finely divided particulate materials, light-reflective pigments, or mixtures thereof.
摘要:
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.
摘要:
An exemplary method for set retarding the surface of a mortar or concrete material, comprising applying to the surface of a mortar or concrete, or to the inner surface of a mold for forming the mortar or concrete, a hot melt coating composition which is heated to assume a flowable or sprayable form, and allowing the hot melt coating composition to cool to ambient temperature whereby the composition forms a solidified membrane, and thereafter removing the membrane. Preferably, the hot melt coating composition contains at least one agent operative to retard the setting of the mortar or concrete, and optional finely divided particulate materials, light-reflective pigments, or mixtures thereof.
摘要:
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.
摘要:
Provided is a method and system for increasing cyclic prefix and cyclic suffix based upon a fast Fourier transform (FFT) and inverse fast Fourier transform (IFFT). The method includes representing at least one of the one or more DMT symbols in frequency domain to produce a frequency domain representation. The frequency domain representation corresponds to a quadrature amplitude modulation (QAM) constellation. Next the QAM constellation is rotated in the frequency domain by changing a characteristic of the DMT symbol as a function of tone index (k), cyclic extension length (CE), inverse fast fourier transform (IFFT) size (N), and pi. Finally, a number of extended symbols are produced to represent the DMT symbol based upon the rotating.
摘要:
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. For each position of the window determining bit allocation for the respective at least one carrier, and in the event that a predetermined average power spectrum density threshold (TPSD) of the carriers over the window for the present window position is not respected, selecting at least one carrier within the window for power spectrum density reduction.
摘要:
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.
摘要:
To generate a pseudo-random sequence of multi-carrier data symbols, a pseudo-random bit sequence is produced by repetitively generating a pseudo-random sequence of L bits, L being a first integer value. To create a multi-carrier data symbol, N bits are used, N being a second integer value. The pseudo-random bit sequence is subdivided into strings of N′ bits, N′ being a third integer value larger than N, and N bits out of each string of N′ bits are used to generate a respective multi-carrier data symbol. N′-N bits out of each string of N′ bits are left unused.
摘要:
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.
摘要:
Provided is a method and system for increasing cyclic prefix and cyclic suffix based upon a fast Fourier transform (FFT) and inverse fast Fourier transform (IFFT). The method includes representing at least one of the one or more DMT symbols in frequency domain to produce a frequency domain representation. The frequency domain representation corresponds to a quadrature amplitude modulation (QAM) constellation. Next the QAM constellation is rotated in the frequency domain by changing a characteristic of the DMT symbol as a function of tone index (k), cyclic extension length (CE), inverse fast fourier transform (IFFT) size (N), and pi. Finally, a number of extended symbols are produced to represent the DMT symbol based upon the rotating.