Abstract: An electro-chemical sensor is described having two molecular redox systems sensitive to the same species and having an detector to detect relative shifts in the voltammograms of the two redox systems.

Abstract: A wirelessly controlled motorized vehicle system may be utilized to facilitate operation of a motorized vehicle. The wirelessly controlled motorized vehicle system may comprise a motorized vehicle and a wireless communications system. The motorized vehicle may comprise a drive system operable to operate the motorized vehicle and a controller in communication with at least a portion of the drive system. The controller may be configured to receive a command from a user. The wireless communications system may be configured to allow wireless communication between the controller and the portion of the drive system. The wireless communications system may comprise one or more transmitters in communication with the controller and one or more receivers in communication with the portion of the drive system. Alternate embodiments may comprise a gauge and/or a central display unit in combination with one or more of the elements listed above.

Abstract: This invention relates to an actuator and has particular reference to linear and rotary actuators, particularly those for use in the control of robotic arms. The invention provides a relatively low cost means of achieving substantially backlashfree rotary and/or linear motion.

Abstract: A well bore treatment fluid of viscoelastic surfactants and methods for increasing the viscosity of the fluid at high temperature without increasing its salt concentration by adding a organic hydrophilic-lipophilic compound and reducing the salt concentration below 6 percent.

Abstract: The present invention is systems and methods for matching desired purchases and sales of mis-matched items. These systems and methods compare the requirements of potential buyers and sellers of items against those of sets of other potential buyers and sellers of items to construct transaction sets that will enable an optimal transaction or set of transactions for the parties involved. The present invention may be used to match purchases and sales of any items, such as goods, services, financial instruments, and property interests (e.g., ownership and/or possessory interests in real property, personal property, etc.).

Abstract: A wellbore fluid comprising a surfactant, the surfactant having the formula (R1—X)nZ, wherein R1 is an aliphatic group—comprising a C18-C22 principal straight chain bonded at a terminal carbon atom thereof to X, and comprising at least one C1-C2 side chain—X is a charged head group, Z is a counterion, and n is an integer which ensures that the surfactant is charge neutral, and wherein the charged head group X is selected to provide that the surfactant is soluble in oil and at least one part of the charged head group is anionic.

Abstract: A powder composition comprising viscoelastic surfactant forms, in aqueous solution, a viscoelastic wellbore treatment fluid.

Abstract: A scale dissolver fluid for dissolving scale in a subterranean hydrocarbon-bearing formation comprises an effective amount of a scale dissolver formulation and an effective amount of a surfactant for controlling the viscosity of the fluid. In use, formation hydrocarbons act on the surfactant to reduce the viscosity of the fluid so that the fluid selectively invades a hydrocarbon-bearing zone of the formation.

Abstract: This invention relates to methods and apparatus for determination of ion concentrations, particularly in downhole water from hydrocarbon wells, aquifers etc. It is useful in a wide range of applications, including predicting the formation of scale and fingerprinting waters from different sources. More particularly, the invention relates to the use of ligands whose electronic configuration is altered by the binding of the scaling ions within a water sample. These alterations are detected, for example by electrochemical means, and are indicative of the concentration of scaling ions in the sample.

Abstract: A computer is used to create a plan for repositioning an orthodontic patient's teeth. The computer receives an initial digital data set representing the patient's teeth at their initial positions and a final digital data set representing the teeth at their final positions. The computer then uses the data sets to generate treatment paths along which the teeth will move from the initial positions to the final positions.

Abstract: A handle assembly for converting a conventional yard cart for use in the manner of a wheelbarrow includes an L-shaped handle including a vertical portion and a horizontal portion. A socket member is connected to the yard cart tow bar which is normally coupled to a garden tractor. The handle member is connected to the socket member after the tow bar is uncoupled from the garden tractor thereby enabling the yard cart to be guided and moved by an operator in the manner of a wheelbarrow.

Abstract: An electrochemical sensor for measuring the amount of hydrogen sulphide or thiols in a fluid in a wellbore comprises a temperature- and pressure-resistant housing containing a flow path for the fluids. The fluids flow over one side of a gas permeable membrane made of zeolite or a suitable ceramic material, the other side of the membrane being exposed to a chamber containing a reaction solution which together with the hydrogen sulphide or thiols create a redox reaction resulting in an electrical current dependent upon the amount of hydrogen sulphide or thiols in the fluid.

Abstract: A method for managing read and write data congestion in a system for executing write and read data commands and having a buffer pool of blocks for temporarily storing read and write data is disclosed. Management of the buffer pool and the initiation of read and write commands ensures that free blocks are available to temporarily store read data arriving at a host bus adapter (HBA). If the currently available blocks would be substantially consumed by the total outstanding inbound read data requested, no more write data commands will be initiated. As inbound read data is received into the buffer pool and subsequently transferred out of the buffer pool to the initiator device, the blocks in the buffer pool are freed up. When the read data transfer is completed and sufficient buffer resources have been freed up, read and write data commands may resume.

Abstract: The invention concerns an apparatus for analysing water chemistry. According to the invention, the apparatus is adapted to operate downhole and comprises a colouring agent supply device for supplying a colouring agent to a water sample, the colour of the water sample thus supplied being indicative of the water sample chemistry, and a colorimetric analyser arranged to determine the colour of the water sample.

Abstract: An electrochemical sensor for measuring the amount of hydrogen sulphide or thiols in a fluid comprises an electrically conductive porous electrode within which are dispersed a precursor and a reaction solution which together with the hydrogen sulphide or thiols a redox reaction resulting in an electrical current dependent upon the amount of hydrogen sulphide or thiols in the fluid. The reaction solution may be initially provided in the pores of the porous electrode, or derived in use from the fluid itself.

Abstract: An electrical stimulation system is provided for electrically stimulating target nerve tissue in a person's brain using a stimulation lead having a tip electrode, having at least five electrodes, or both. The system includes a stimulation lead adapted for implantation into the brain for electrical stimulation of target nerve tissue in the brain. The stimulation lead may include a tip electrode located at a distal tip of the stimulation lead and adapted to be positioned proximate the target nerve tissue in the brain and to deliver electrical stimulation pulses to the target nerve tissue in the brain. The stimulation lead may include at least five electrodes, one or more of which are adapted to be positioned proximate the target nerve tissue in the brain and to deliver electrical stimulation pulses to the target nerve tissue in the brain.

Abstract: In one embodiment, a lead introducer kit for preparing to implant an electrical stimulation lead for electrical stimulation of nerve tissue is provided. The lead introducer kit includes a needle, a guide wire, a lead blank having a similar shape and size as an electrical stimulation, and an introducer. The lead blank is configured for insertion into the human body to determine whether the electrical stimulation lead may be inserted into position proximate nerve tissue to be stimulated. The introducer includes an inner penetrator removably housed within an outer sheath and including an inner channel configured to accommodate the guide wire. The inner penetrator is configured to be advanced along the guide wire to a desired location relative to the nerve tissue and removed from the outer sheath leaving the outer sheath in position for insertion of the lead blank to determine whether the electrical stimulation lead may be inserted into position proximate the nerve tissue to be stimulated.

Abstract: In one embodiment, an introducer is provided for implanting a paddle style electrical stimulation lead to enable electrical stimulation of nerve tissue. The introducer includes an outer sheath and an inner penetrator. The outer sheath may accommodate insertion of the paddle style electrical stimulation lead and may be inserted into a human body near the nerve tissue. The inner penetrator is removably housed within the outer sheath and includes an inner channel configured to accommodate a guide wire, a tip end having a shape and size substantially conforming to that of the guide wire, a body region having a shape and size substantially conforming to that of the outer sheath, and one or more transition regions substantially connecting the tip end with the body region.

Abstract: A method of monitoring gas in a downhole environment is discussed which provides downhole a mid-infrared light emitting diode, operates the diode to transmit respective infrared signals on a first optical path extending from the diode through a downhole gas sample and a second optical path extending from the diode through a reference gas sample, detects the transmitted infrared signals, and determines the concentration of a component of the downhole gas sample from the detected signals.

Abstract: A method of forming the active region of an optoelectronic device incorporating semiconductor quantum dots whose ground state emission occurs at wavelengths beyond 1350 nm at a temperature of substantially 293 K is provided by forming a first layer of quantum dots covered by a spacer layer with strained areas extending there through. The spacer layer then forms a template upon which quantum dots of an active layer may be formed with a surface with a surface density and formation that is influenced by the underlying first layer of quantum dots. This allows a choice of growth parameters more favourable to the formation of quantum dots in the active layer emitting at long wavelengths with a narrow inhomogeneous broadening. As an example, the active layer of quantum dots may be formed at a lower temperature than the first layer of quantum dots.