Abstract: A modulator for a spread spectrum telecommunication system not only receives local data and processes it, but also receives input data from one or more other modulators, sums the input data with the local data, and provides the sum as data for a subsequent modulator or as final output for a transmit power amplifier. The modulator includes an input block and an output block and, depending on a control data signal, input data will be summed with the internally generated local data of the modulator before being provided to the output block. The output data can include parity data. The parity data can be used to check for faults such as might be introduced, for example, by a faulty connection or broken hard-wired interconnect. If an error is detected, the summation function of the transmit modulator can be automatically disabled.

Abstract: A composite abrasive wheel with improved thermal properties is comprised of a fibrous substrate with abrasive particles adhered thereto by a crosslinked polyurethane binder comprising heterocyclic groups. The heterocyclic structures, such as isocyanurate and/or oxazolidone rings, in the binder system improve the thermal properties required for a tough, durable abrasive wheel.