Abstract:
Soft handover of a mobile unit is facilitated on a wireless network from base station to base station. The network can employ multi-channel receivers to receive signals from mobile units within range, including mobile units assigned to neighboring base stations. Information associated with received signals, such as an indication of their signal strength, can be relayed to a central location for assessing whether the mobile unit should be assigned to another base station, and implement reassignment of one or more mobile units based on such assessment. Soft handover reduces dropped calls when the connection from mobile to base station is unexpectedly lost. The second BTS can add a carrier to communicate with the mobile unit and provides the mobile unit with the necessary parameters, such as frequency and time slot data, to complete the handover or the connection can be established through a variety of contingency plans.
Abstract:
Systems and methods are provided for providing high dynamic range operation over a variable range of frequencies. A delta-sigma modulator, having associated frequency characteristics, produces a digital output signal. A digital-to-analog converter converts the digital output signal into an analog signal. A clock circuit provides a clock signal to the delta-sigma modulator and the digital-to-analog converter. A frequency control controls one or more of the clock circuit, the delta-sigma modulator, and the digital-to-analog converter to alter the frequency characteristics of the delta-sigma modulator. A filter circuit can provide one or more passbands to one or more downstream amplifiers ensuring that out of band quantization noise is removed before amplification.
Abstract:
An amplification system and method is provided that employs a digital cross-cancellation technique which provides a separate digital signal to be input to a separate DAC to generate a cancellation signal. The cancellation signal is added to the output of the amplifier to produce a final signal with substantially reduced distortion and/or out-of-band emissions. The cancellation signal can be pre-computed or derived by generating an inverted version of the wanted signal, and combining it with a portion of the output signal to determine the error or unwanted portion of the output signal. This error signal is then combined with a delayed version of the output signal.
Abstract:
A roller mill includes a base, a pulverizing table having a substantially horizontal upper surface, supported against the base and arranged to rotate around a vertical axis intersecting the upper surface in a center point thereof, an annular groove, formed on the upper surface of the pulverizing table, adjacent to an outer periphery of the table, at least one roller shaft mounted pivotally on the base in proximity to the table, at an angle &agr; with respect to a horizontal direction, toward the center point and having an end portion located above the table, a pulverizing roller supported rotatably against the end portion of the at least one roller shaft and a device for pressing the pulverizing roller toward the annular groove. An outer peripheral surface of the pulverizing roller has a smooth, generally arcuate cross section with at least one substantially flat section in the central portion thereof.
Abstract:
System and methods are provided for selective noise generation. A delta-sigma modulator receives digital input and produces a digital output. A digital-to-analog converter converts the digital output into an analog output. The analog output comprises quasi-random noise having at least one low noise frequency band. The low noise frequency bands have respective associated shapes and center frequencies. A frequency control controls the delta-sigma modulator to alter one of the respective center frequency and the shape of the at least one low noise frequency band.
Abstract:
A two-part coating system comprises a first part comprising one or more aliphatic polyisocyanates, optionally blended with one or more “amine reactive” resins and/or non reactive resins, and a second part comprising one or more aromatic polyamines optionally blended with one or more oligomeric polyamines, such that the two parts, when mixed together and applied to the internal surfaces of pipelines, form a rapid setting impervious coating suitable for contact with drinking water.
Abstract:
A method of protecting from corrosion the junction between adjoining plastics coated, metal pipes, in a pipeline installation or the like, comprising roughening the exposed surface of the plastics coating on either side of the junction region, applying a primer over the abraded region of the plastics coating, allowing or causing the primer to cure or dry, and subsequently applying over the said junction region and over the regions primed with said primer, a protective top coat.
Abstract:
Provided are reactive compositions for making a polyurethane-based rain-erosion protective coating for rotor blades, the reactive composition comprising an isocyanate-reactive component and an isocyanate-functional component and wherein the isocyanate-reactive component comprises a first component i) being a short chain hydroxyl-functional compound having two terminal (α-ω) hydroxyl groups, a molecular weight of less than 250 g/mole and containing at least 2 carbon atoms and a second component ii) comprising a high molecular weight hydroxyl-functional compound having two terminal (α-ω) hydroxyl groups and a molecular weight of at least 250 g/mol and comprising one or more units selected from oxyalkylene units and polyoxyalkylene units and wherein the isocyanate-functional component is an isocyanate prepolymer of the general formula NCO—Z—NCO, wherein Z is a linking group comprising at least two urethane (—NH—CO—O—) units and additionally one or more units selected from alkylenes, oxyalkylenes, polyoxyalkylenes, alkylene esters, oxyalkylene esters, polyoxyalkylene esters and combinations thereof. Also provided are protective coatings obtained from the reactive compositions and methods of applying the coatings to articles.
Abstract:
Provided are reactive compositions for making a polyurethane-based rain-erosion protective coating for rotor blades, the reactive composition comprising an isocyanate-reactive component and an isocyanate-functional component and wherein the isocyanate-reactive component comprises a first component i) being a short chain hydroxyl-functional compound having two terminal (α-ω) hydroxyl groups, a molecular weight of less than 250 g/mole and containing at least 2 carbon atoms and a second component ii) comprising a high molecular weight hydroxyl-functional compound having two terminal (α-ω) hydroxyl groups and a molecular weight of at least 250 g/mol and comprising one or more units selected from oxyalkylene units and polyoxyalkylene units and wherein the isocyanate-functional component is an isocyanate prepolymer of the general formula NCO—Z—NCO, wherein Z is a linking group comprising at least two urethane (—NH—CO—O—) units and additionally one or more units selected from alkylenes, oxyalkylenes, polyoxyalkylenes, alkylene esters, oxyalkylene esters, polyoxyalkylene esters and combinations thereof. Also provided are protective coatings obtained from the reactive compositions and methods of applying the coatings to articles.
Abstract:
Methods of coating surfaces of a (e.g. drinking water) pipeline and pigments dispersions are described. The coating composition of the method and pigment dispersion comprise one or more alkyl phenyl ester compounds wherein the alkyl group comprises at least 8 carbon atoms.