7807 results about "Steady state" patented technology

A method for determining the concentration of a reduced (or oxidised) form of a redox species in an electrochemical cell of the kind comprising a working electrode and a counter electrode spaced from the working electrode by a predetermined distance, said method comprising the steps of: (1) applying an electric potential difference between the electrodes; (2) selecting the potential of the working electrode such that the rate of electro-oxidation of the reduced form (or electro-reduction of the oxidised form) of the species is diffusion controlled, (3) selecting the spacing between the working electrode and the counter electrode so that reaction products from the counter electrode arrive at the working electrode; (4) determining current as a function of time after application of the potential and prior to achievement of a steady state; (5) estimating the magnitude of the steady state current, and (6) obtaining from the change in current with time and the magnitude of the steady state current, a value indicative of the diffusion coefficient and / or of the concentration of the reduced form (or the oxidised form) of the species. Also disclosed is an apparatus for determining the concentration of a redox species in an electrochemical cell comprising: an electrochemical cell having a working electrode and a counter (or counter / reference) electrode, means for applying and electric potential difference between said electrodes, means for measuring the change in current with time, and characterised in that the working electrode is spaced from the counter electrode by less than 500 mum.

A medical robotic system having non-ideal actuator-to-joint linkage characteristics, includes a control system including a proximal control loop with actuator sensor feedback to control dynamic response of an actuator coupled to a distal joint which in turn, is coupled to an end effector to provide a degree of freedom movement of the end effector, a distal control loop with distal joint sensor feedback and feedforward to the actuator to ensure steady-state convergence of the distal joint position, and an end effector control loop with end-point sensor feedback to control the end effector position to reach a commanded end effector position.

A stable continuous method for producing ethanol from the anaerobic bacterial fermentation of a gaseous substrate containing at least one reducing gas involves culturing a fermentation bioreactor anaerobic, acetogenic bacteria in a liquid nutrient medium; supplying the gaseous substrate to the bioreactor; and manipulating the bacteria in the bioreactor by reducing the redox potential, or increasing the NAD(P)H TO NAD(P) ratio, in the fermentation broth after the bacteria achieves a steady state and stable cell concentration in the bioreactor. The free acetic acid concentration in the bioreactor is maintained at less than 5 g / L free acid. This method allows ethanol to be produced in the fermentation broth in the bioreactor at a productivity greater than 10 g / L per day. Both ethanol and acetate are produced in a ratio of ethanol to acetate ranging from 1:1 to 20:1.

A method and system of controlling element activation within arrays subject to row and column address signaling. The display, or other form of output device, is configured with circuitry for controlling element activation. The multiplexed row and column signals are utilized for commanding activation of the element, whereas power is constantly provided for driving the display element. By way of example, an embodiment is described wherein the row and column lines can be driven from providing steady-state power to selecting the element for activation or deactivation during the next multiplexing interval. Additional display embodiments are described to suit various applications.

Oxycodone formulations are provided which produce substantially flat in vivo steady state plasma profiles. Tolerance levels associated with such profiles and tolerance levels associated with biphasic profiles are shown not to be statistically different. The substantially flat in vivo steady state plasma profiles are produced by dosage forms having substantially zero order in vitro release profiles. Such release profiles produce low single dose in vivo Cmax levels which can reduce the probability of adverse side effects.

The present invention relates to particulate compositions of a lower ash type petroleum coke containing at least two preselected components (alkali metal and calcium) that exhibit an efficient, enhanced-yielding gasification to value added gaseous products, particularly when used in a steady-state integrated gasification process. The compositions of the present invention are particularly useful for catalytic gasification of petroleum coke at moderate temperatures ranging from about 450° C. to about 900° C. Advantageously, the compositions can be readily incorporated into fluidized bed gasification units, and can result in a cost-effective, high-yielding production of methane gas from petroleum coke.

A new current loop control system method is proposed for a single-phase grid-tie power conditioning system that can be used under a standalone or a grid-tie mode. This type of inverter utilizes an inductor-capacitor-inductor (LCL) filter as the interface in between inverter and the utility grid. The first set of inductor-capacitor (LC) can be used in the standalone mode, and the complete LCL can be used for the grid-tie mode. A new admittance compensation technique is proposed for the controller design to avoid low stability margin while maintaining sufficient gain at the fundamental frequency. The proposed current loop controller system and admittance compensation technique have been simulated and tested. Simulation results indicate that without the admittance path compensation, the current loop controller output duty cycle is largely offset by an undesired admittance path. At the initial simulation cycle, the power flow may be erratically fed back to the inverter causing catastrophic failure. With admittance path compensation, the output power shows a steady-state offset that matches the design value. Experimental results show that the inverter is capable of both a standalone and a grid-tie connection mode using the LCL filter configuration.

The present invention pertains to a system for processing semiconductor wafers. The processing may involve the removal of material from the wafers or deposition of material on the wafers. Various aspects of the invention include specialized pressurization, process vessel, recirculation, chemical addition, depressurization, and recapture-recycle subsystems. A solvent delivery mechanism can convert a liquid-state sub-critical solution to a supercritical processing solution and introduce it into a process vessel that contains a batch of wafers. The wafers may be rotated within the supercritical processing solution. The supercritical processing solution is preferably recirculated through the process vessel by a recirculation system. When chemical additives are added to a supercritical solvent, the momentum of the chemical additives are preferably matched to the momentum of the supercritical solvent. Additives may be added at a higher initial flow rate, then ramped down a lower flow rate, e.g., a steady-state flow rate.

Disclosed is a system and methods for accelerating network protocol processing for devices configured to process network traffic at relatively high data rates. The system incorporates a hardware-accelerated protocol processing module that handles steady state network traffic and a software-based processing module that handles infrequent and exception cases in network traffic processing.

A medical robotic system has a robot arm holding an instrument for performing a medical procedure, and a control system for controlling movement of the arm and its instrument according to user manipulation of a master manipulator. The control system includes at least one joint controller that includes a controller having programmable parameters for setting a steady-state velocity error and a maximum acceleration error for the joint's movement relative to a set point in response to an externally applied and released force.

Structures and methods to form a bistable resistive random access memory for reducing the amount of heat dissipation from electrodes by confining a heating region in the memory cell device are described. The heating region is confined in a kernel comprising a programmable resistive memory material that is in contact with an upper programmable resistive memory member and a lower programmable resistive memory member. The lower programmable resistive member has sides that align with sides of a bottom electrode comprising a tungsten plug. The lower programmable resistive member and the bottom electrode function a first conductor so that the amount of heat dissipation from the first conductor is reduced. The upper programmable resistive memory material and a top electrode function as a second conductor so that the amount of heat dissipation from the second conductor is reduced.

A level shift circuit includes an input stage and an output stage coupled to each other by two nodes. The input stage changes the voltages on the nodes according to an input signal, and the output stage determines an output signal according to the voltages on the two nodes. In a transition state, the input stage provides a large current to charge or discharge the first node or the second node so as to quickly change the voltage thereon. In a steady state, the input stage lowers the current so as to reduce power consumption.

A method for operating at least one wind turbine with a rotor and an electric generator coupled to the rotor for delivering electrical power into an energy distribution system with the aid of a control device ensures that the wind turbine operates within its operating range. The wind turbine is controlled in response to the change of a system operating parameter and for a period of time, in such a manner that a higher power is fed into the system than belongs to the operating range of the steady-state operation. The same conditions also apply to a method for providing control power or primary control power for an electric energy generator and distributor system to which a multiplicity of power stations including wind turbines is connected, and to a wind turbine.

The present invention provides a power regulation system and method with high speed signal settling capabilities for providing rapid active transient response to a microelectronic device. An active transient response system includes a power supply configured to receive external and / or internal signals indicating the occurrence of transient load conditions and to respond to the transient load conditions based on one or more of these signals. The system may further include a transient suppressor configured for early detection of transients, assisting in transient suppression, and early signaling of transient activity to the power supply.The system provides rapid recovery to steady state operation from the active transient response mode by using a digital compensator to quickly modifying the duty cycle and provide a voltage offset proportional to the transient microprocessor load step. Recovery is further improved by current rephasing techniques.

The present invention provides a method and apparatus for controlling the thermal stress in lighting devices, for example light-emitting elements, that are exposed to large thermal gradients typically upon start-up, for example light-emitting elements operating in relatively cold ambient environments. The present invention provides an apparatus that can reduce this thermal stress, wherein the apparatus comprises a temperature determination mechanism for evaluating the temperature of the light-emitting elements prior to activation, and a control system to control the drive current such that it is gradually ramped up to the desired steady state peak current value, wherein the ramping of the drive current is dependent on the evaluated temperature of the light-emitting element.

A wearable device that may transform between an annularly bent state and a flat state is provided. The wearable device includes a plurality of segment members including a top portion and a bottom portion having a shorter length than the top portion; a plurality of connecting members that are disposed to correspond to the plurality of segment members, wherein each of the plurality of connecting members is connected to be mutually rotatable with two segment members disposed respectively on both sides thereof; a bistable spring that is supported on a plurality of segment members to provide elasticity in a direction into the annularly bent state and retentivity of the flat state; and a flexible display device that is supported on the top portion of the plurality of segment members.

A DC-to-DC converter having a transformer with a primary and a tapped secondary, two serial output filter inductors connected parallel with the secondary, a center output filter inductor connected between the secondary tap and serial output inductors, two serially connected switches connected in parallel with the two output inductors for receiving a signal to control operation of the switches during steady state and an output load connected between the serial connection of the serial output inductors and serial switching devices. The transformer primary side connected with double-ended primary-side topologies. The transformer secondary and output filers configured to form a current tripler rectifier, current quadtupler rectifier or current N-tuper rectifier. The output filter inductors evenly share output current resulting in reduction of current and thermal stress during high current application and the rectification topology has simple driving for synchronous rectifier application without increasing complexity of control and operation of primary-side topologies.

A vehicle control system that selectively provides rear-wheel steering to prevent a vehicle-trailer from jackknifing during a back-up maneuver. The system senses a steering angle of the vehicle, a speed of the vehicle and a hitch angle between the vehicle and the trailer. The system calculates an equilibrium hitch angle that is a steady-state hitch angle position based on the steering angle and the vehicle speed, and a pseudo-equilibrium hitch angle that is a steady-state hitch angle at a maximum rear-wheel steering input based on the steering angle and the vehicle speed. The system then determines whether the rear-wheel steering should be provided based on a predetermined relationship between the sensed hitch angle, the equilibrium hitch angle and the pseudo-equilibrium hitch angle.

A closed-loop LRF pointing technology to measure the range of a target satellite from a chaser satellite for rendezvous is provided that includes several component technologies: LOS angle measurements of the target satellite on a visible sensor focal plane and the angles' relationships with the relative position of the target in inertial or LVLH frame, a relative navigation Kalman filter, attitude determination of the visible sensor with gyros, star trackers and a Kalman filter, pointing and rate commands for tracking the target, and an attitude controller. An analytical, steady-state, three-axis, six-state Kalman filter is provided for attitude determination. The system and its component technologies provide improved functionality and precision for relative navigation, attitude determination, pointing, and tracking for rendezvous. Kalman filters are designed specifically for the architecture of the closed-loop system to allow for pointing the laser rangefinder to a target even if a visible sensor, a laser rangefinder, gyros and a star tracker are misaligned and the LOS angle measurements from the visible sensor are interrupted.

The power flow model of the multiterminal voltage-source converter-based high voltage DC (M-VSC-HVDC) transmission system for large-scale power systems is studied. The mathematical model is derived using the d-q axis decomposition of HVDC's control parameter. The developed model can be applied to all existing shunt voltage-source converter (VSC) based controllers, including Static Synchronous Compensator (STATCOM), point-to-point HVDC system, back-to-back HVDC system and multiterminal HVDC system. A unified procedure is developed for incorporating the proposed model into the conventional Newton-Raphson power flow solver. The IEEE 300-bus test system embedded with multiple HVDC transmission systems under different configurations are investigated. Simulation results reveal that the proposed model is effective and accuracy in meeting various control objectives.

A spherical display and control device, that is preferably collapsible between a spherical configuration and a collapsed generally cylindrical ellipsoid configuration, comprising a flexible transparent spherical surface sprung attached to a central hinged modular cube assembly that contains digital displays on outward faces, and circuitry, battery units and electronic modules on inward surfaces, where said sphere surface contains surface position sensing layers and said central cube contains gyroscopic and inertial sensing devices to provide spherical rotation, and physical displacement data for three dimensional control applications, where said displays preferably have curved polarizer lenses such that the overall device appears as a spherical display or are flat to form an overall Cuboid display or are combined with a flexible spherical display surfaces. The overall device being mechanically biased such that it is Bi-stable between the spherical and collapsed configuration via the action of pulling open and rotating the central cube halves.

A ferroelectric liquid crystal display including an upper base plate and a lower base plate which are disposed apart from each other at a predetermined distance, electrode layers respectively formed on the upper base plate and the lower base plate facing each other, orientation layers respectively formed on the electrode layers and treated by rubbing in a first rubbing direction and a second rubbing direction which intersect at a predetermined angle, and a liquid crystal layer disposed between the orientation layers and filled with a ferroelectric liquid crystal having a bookshelf structure. Due to the ferroelectric liquid crystal display and the method of manufacturing the same, the ferroelectric liquid crystal of the bookshelf structure can stably twist by the treatment of the orientation such that an afterimage phenomenon is prevented and further a low threshold voltage and a bistability can be obtained.

An improved method of controlling build-up of adhesive coating on a Yankee drying cylinder preferably includes intermittently: (a) increasing the add-on rate of resinous adhesive to the drying cylinder substantially above the steady-state add-on rate; (b) segregating the absorbent sheet product produced while the add-on rate of resinous adhesive to the drying cylinder is elevated above the steady-state add-on rate from absorbent sheet product accumulated during steady-state operation; and (c) while the add-on rate of resinous adhesive to the drying cylinder is increased above the steady-state add-on rate, stripping at least a portion of the adhesive coating from the drying cylinder with a cleaning doctor.