Abstract: The connections to anodes used in impressed current electrochemical treatments of steel in concrete construction are at risk from rapid corrosion arising from induced anodic dissolution when these connections are embedded in reinforced concrete. A corrosion resistant connection that does not require any further protective insulation can be formed using titanium conductors [2,6] and connecting the conductors together at a conductor-conductor connection [5] using a clamping device comprising a non-metallic material wherein the clamping device only brings corrosion resistant material into contact with the conductors.

Abstract: An electric field modifier for boosting a current output of a sacrificial anode to enhance its protective effect and direct the current output to improve current distribution in galvanic protection of steel in a concrete element exposed to air is disclosed. A cavity is formed in a concrete element and a combination comprising a sacrificial anode, an electric field modifier and an ionically conductive filler are embedded therein. The sacrificial anode is connected to the steel. The modifier comprises an element with an anode side, supporting an oxidation reaction, in electrical contact with a cathode side, supporting a reduction reaction. The cathode of the modifier faces the sacrificial anode and is separated therefrom by a filler which contains an electrolyte that connects the sacrificial anode to the cathode of the modifier. The anode of the modifier faces away from the sacrificial anode. Preferably, the reduction reaction, on the cathode of the modifier, comprises reduction of oxygen from the air.

Abstract: A wired reamer for use on a downhole drillstring is disclosed. In some embodiments, the reamer includes a reamer body comprising a pathway therethrough and wiring located within the pathway for transmitting at least one of power or communications. In other embodiments, the reamer includes a reamer body comprising a pathway enclosed within the reamer body, wiring located within the pathway for transmitting at least one of power or communications, a sensor and a processor located within the reamer body. The sensor is connected with the wiring for transmitting data measured by the sensor through the wiring, and the processor is connected with the wiring for receiving the data from the sensor.

Abstract: A method of protecting steel in concrete is disclosed. A voltage between two connections of a power supply is generated such that current can flow between a negative connection and a positive connection. In a first protection step, one of the connections of the power supply is electrically connected to the steel to be cathodically protected and a sacrificial anode is electrically connected in series with the other connection of the power supply such that the voltage generated by the power supply is added to the voltage generated between the sacrificial anode and the steel to produce a voltage greater than the voltage generated between the sacrificial anode and the steel alone. The power supply may be a cell or battery and may be combined with the sacrificial anode to form a single unit.

Abstract: High performance proprietary cementitious concretes or mortars developed for use as patch repair materials for corrosion damaged concrete often have high resistivities that inhibit the performance of sacrificial anodes located within the patch repair areas. A method of repair is disclosed which comprises removing the corrosion damaged concrete to form a cavity to receive a concrete repair material and forming within this cavity a smaller distinct cavity for assembling a sacrificial anode assembly and placing within this second cavity a pliable viscous ionically conductive backfill and a sacrificial anode and an activating agent to form a sacrificial anode assembly and connecting the anode to the steel and covering the anode and the backfill in the second cavity with a repair material to restore the profile of the concrete structure. In this arrangement a high resistivity repair material promotes the flow of protection current to steel in adjacent contaminated concrete that is at risk of corrosion.

Abstract: High performance proprietary cementitious concretes or mortars developed for use as patch repair materials for corrosion damaged concrete often have high resistivities that inhibit the performance of sacrificial anodes located within the patch repair areas. A method of repair is disclosed which comprises removing the corrosion damaged concrete to form a cavity to receive a concrete repair material and forming within this cavity a smaller distinct cavity for assembling a sacrificial anode assembly and placing within this second cavity a pliable viscous ionically conductive backfill and a sacrificial anode and an activating agent to form a sacrificial anode assembly and connecting the anode to the steel and covering the anode and the backfill in the second cavity with a repair material to restore the profile of the concrete structure. In this arrangement a high resistivity repair material promotes the flow of protection current to steel in adjacent contaminated concrete that is at risk of corrosion.

Abstract: Sacrificial anode assemblies have the advantage that they can provide galvanic protection to steel in concrete and do not require long term maintenance of a DC power supply. However sacrificial anode assemblies often loose adhesion to the concrete surface. This invention discloses the use of a sacrificial anode (4) and a backfill (3) and a tape (5) and an adhesive to protect steel (8) in concrete. The backfill is preferably placed in a shallow cavity (1) in the concrete surface (2) and the sacrificial anode is inserted into the backfill. The cavity is covered with a tape that extends over the adjacent concrete surfaces on opposite sides of the sacrificial anode and backfill and the tape is attached to the concrete surface with the adhesive. The tape and the adhesive holds the anode in place and prevents a weathering environment from damaging the backfill.

Abstract: The connections to anodes used in impressed current electrochemical treatments of steel in concrete construction are at risk from rapid corrosion arising from induced anodic dissolution when these connections are embedded in reinforced concrete. A corrosion resistant connection that does not require any further protective insulation can be formed using titanium conductors [2,6] and connecting the conductors together at a conductor-conductor connection [5] using a clamping device comprising a non-metallic material wherein the clamping device only brings corrosion resistant material into contact with the conductors.

Abstract: A fractional N phase locked loop (PLL) includes a programmable digital signal processor (DSP) to perform various processing functions within the PLL. In at least one embodiment, the programmable nature of the DSP allows programs to be modified and/or added to the PLL to support a variety of different applications.

Abstract: A method and apparatus to bias each of a plurality of stages of a limiting amplifier are described.

Abstract: According to one embodiment a microelectromechanical (MEMS) switch is disclosed. The MEMS switch includes a pulse generator to provide a low voltage source, a transformer coupled to the pulse generator to boost a voltage received from the pulse generator and a switch component coupled to the pulse generator. The switch component includes an actuation capacitor to store charge associated with the voltage received from the transformer.

Abstract: In one embodiment, the present invention includes a differential traveling wave amplifier having a lumped differential preamplifier stage and a distributed differential amplifier stage coupled by a differential end termination interface. In certain embodiments, the distributed differential amplifier stage may include transverse electromagnetic transmission lines coupled between its input and output.

Abstract: In one embodiment, the present invention includes an apparatus having a threshold detector with a current comparator to determine if an input signal exceeds a threshold. The input signal may be obtained from a received optical signal and may be compared to a reference signal obtained from a hierarchical Schmitt trigger, in certain embodiments.

Abstract: A method and apparatus to bias each of a plurality of stages of a limiting amplifier are described.

Abstract: A method and apparatus to provide slice adjustment and offset cancellation in a high frequency limiting amplifier is described.

Abstract: An amplifier includes a Darlington transistor pair and a biasing network to increase bias currents in an input transistor.

Abstract: The invention provides a reinforced concrete having improved corrosion resistance in which the content of voids in the concrete at the surface of the steel reinforcement is below 0.8%, preferably below 0.5%, more preferably below 0.2% by area of steel and in which there is a layer of solid alkali, preferably at least one micron in thickness on the steel surface. The reinforced concrete preferably has a chloride threshold level of at least 0.5% preferably at least 0.8% by weight of the cement. The invention also provides a process for reducing corrosion of steel reinforcement in concrete which comprises forming a reinforced concrete in which the voids at the steel surface are below 0.5% by volume and in which there is a layer of solid alkali on the steel surface the layer being at least 1 micron in thickness and covering at least 20% of the steel surface.

Abstract: The invention provides a reinforced concrete having improved corrosion resistance in which the content of voids in the concrete at the surface of the steel reinforcement is below 0.8%, preferably below 0.5%, more preferably below 0.2% by area of steel and in which there is a layer of solid alkali, preferably at least one micron in thickness on the steel surface. The reinforced concrete preferably has a chloride threshold level of at least 0.5% preferably at least 0.8% by weight of the cement. The invention also provides a process for reducing corrosion of steel reinforcement in concrete which comprises forming a reinforced concrete in which the voids at the steel surface are below 0.5% by volume and in which there is a layer of solid alkali on the steel surface the layer being at least 1 micron in thickness and covering at least 20% of the steel surface.