Abstract: A system and method for maintaining fluid pressure within a well bore includes: (a) an axially reciprocable choke; (b) a mud pump; (c) a programmable controller in communication with the choke and providing operational control of the axial reciprocation of the choke to maintain a set point choke pressure; (d) the controller configured to associate a drilling set point choke pressure within the well bore with a drilling pump rate and associate a predetermined connection set point choke pressure within the well bore with a pump rate; and (e) a mud pump monitor configured to communicate with the mud pump and the programmable controller, measure the pump rate of the pump, and communicate the measured pump rate to the programmable controller.

Abstract: The present disclosure contemplates a method and apparatus for maintaining well pressure control despite fluctuations arising due to mud pump speed changes during startup and shutdown of a mud pump. More particularly, the present disclosure relates to a method and apparatus for closely coordinating changes in mud pump speed, or the flow rate of drilling mud, with the operation of choke valves for the maintenance of a constant drilling fluid pressure during drilling breaks such as the addition of drill pipe sections to the drill string.

Abstract: Baseline values for battery testing are automatically determined for individual batteries, battery cells, or networks of batteries. Impedance information is obtained from individual batteries and adjusted for operating conditions at a site of use (e.g., temperature, age, connection topology and user-entered information). Population-referenced baselines are automatically calculated from the group of individual-referenced baselines. All baselines can be continually updated and improved. The state of charge and state of health characteristics of batteries in the network can be automatically determined by comparison of measured impedance, and other values, to the baselines.

Abstract: A temperature is measured for each terminal of the battery unit. The magnitude and sign of a temperature differential is calculated from the temperatures. The temperature differential is then correlated to a deteriorating condition of the battery unit.

Abstract: Determination of a remaining life fraction for a network of batteries during use in an electrical circuit is disclosed. A state of health of the battery network can be determined by measuring a change in impedance characteristics of the individual battery units and/or the battery network as a whole. More specifically, a mode and a severity of a failure can be determined for individual battery units.

Abstract: DC offsets introduced in battery testing equipment are automatically compensated for using complementary current-mode servo feedback. An op amp receives and amplifies a response signal, while also introducing internal errors manifested in the amplified response signal. A correction circuitry coupled to receive the amplified response signal and comprising a balanced circuit with a positive input correction device and a negative input correction device to remove the DC bias. The correction circuitry further comprises an error sensing device to correct for the internal errors introduced by the op amp.

Abstract: Determination of a remaining life fraction for a network of batteries during use in an electrical circuit is disclosed. A state of health of the battery network can be determined by measuring a change in impedance characteristics of the individual battery units and/or the battery network as a whole. More specifically, a mode and a severity of a failure can be determined for individual battery units.

Abstract: DC offsets introduced in battery testing equipment are automatically compensated for using complementary current-mode servo feedback. An op amp receives and amplifies a response signal, while also introducing internal errors manifested in the amplified response signal. A correction circuitry coupled to receive the amplified response signal and comprising a balanced circuit with a positive input correction device and a negative input correction device to remove the DC bias. The correction circuitry further comprises an error sensing device to correct for the internal errors introduced by the op amp.

Abstract: A temperature is measured for each terminal of the battery unit. The magnitude and sign of a temperature differential is calculated from the temperatures. The temperature differential is then correlated to a deteriorating condition of the battery unit.

Abstract: The invention provides a method for capturing and analyzing the total electrical response to a time-varying electrical stimulation of a system or device containing electrochemically active biological or non-biological substances. The response can be either a time-varying voltage (in the case of current-mode stimulation), or a time-varying current (in the case of voltage-mode stimulation). Using synchronous data acquisition technology and advanced data analysis, the method yields not only the idealized 2-parameter information (e.g., phase and amplitude) provided by conventional methods, but also parameters extracted from non-ideal features of the response waveform that are suppressed by impedance methods. By extracting the full range of response characteristics, the method yields a multi-parameter representation of the system or device under test.

Abstract: The composition of an electrically conductive mixture, such as a mixture of gasoline and alcohol, is measured using a single measurement cell having a first electrode and a second electrode with a measurement space therebetween for receiving a specimen of the mixture. With a specimen of the mixture in the measurement space, the first electrode is alternatively connected to a reference discharge voltage, preferably ground, and to an applied voltage through a resistor. A first operational state encompasses the period when the first electrode is connected to the reference discharge voltage and a second operational state encompasses the period when the first electrode is connected to the applied voltage through the resistor. A first operational state peak voltage is measured during the first operational state, and a second operational state peak voltage is measured during the second operational state.

Abstract: The composition of an electrically conductive mixture, preferably a mixture of gasoline and alcohol, is measured using a single measurement cell having a first electrode and a second electrode with a measurement space therebetween for receiving a specimen of the mixture. With a specimen of the mixture in the measurement space, the first electrode is alternatively connected to a reference discharge voltage, preferably ground, and to a feedback control voltage. A first operational state encompasses the period when the first electrode is connected to the reference discharge voltage and a second operational state encompasses the period when the first electrode is connected to the feedback control voltage. A first operational state peak voltage is measured during the first operational state, and a peak second operational state voltage is measured during the second operational state.

Abstract: A simple robust sensor probe for determining the magnesium concentration in molten metal alloys in real-time. The probe provides needed process control information in molten metal technologies and has particular application to processes for removing magnesium impurities from scrap aluminum. The probe employs a specially constructed electrochemical concentration cell adapted for repeated immersions into vessels containing molten metal alloys. Specifically, the probe comprises two electrodes, both inert to a molten salt layer, to the molten metal (aluminum), and to magnesium. One electrode comprises an inverted molybdenum cup, a magnesium reference material, and a fibrous ceramic wick, e.g., yttrium oxide, for retaining molten salt therein in contact with the magnesium reference material when the sensor probe is first inserted into the molten salt layer and then into the molten aluminum layer.

Abstract: An improved device for monitoring the presence of toxic metals in workplace air comprises a base and a removable top assembly. The top assembly includes a test substrate, such as filter paper, having a first surface and a second surface. The first surface is supported by the top assembly and the second surface has an area that is sensitized with at least one chemical reagent for producing a reaction with at least one toxic metal. The base has an air inlet, an air outlet, and a channel connecting the air inlet and the air outlet, thereby enabling air entering the monitor from the air inlet to directly contact the area of the second surface of the test substrate prior to exiting the monitor through the air outlet.

Abstract: An device for monitoring workplace air comprises a monitor cell comprising a base and a removable assembly. The removable assembly comprises (1) a flat, electrically insulating substrate having a first surface, (2) an electrolyte cell having an anode and a cathode disposed on the first surface, the anode and cathode spaced apart to define a controlled volume for holding a quantity of an electrolyte, and (3) means for applying a controlled electrical potential to the cathode. The base comprises (1) an air inlet portion for sampling air, (2) an air outlet portion connected to an air sampling pump, (3) a channel connecting the air inlet and the air outlet and adapted to introduce air to the electrolyte in the electrolyte cell, (4) a reservoir for storing the electrolyte for the electrolyte cell, and (5) a wick for supplying electrolyte from the reservoir to the electrolyte cell.

Abstract: Precise information about the position of a liquid-liquid interface (28, 32) is often important for the control and automation of molten metal refining processes. For example, in an electrolytic process for removing magnesium from molten aluminum, knowledge of the vertical position of an interface (32) between the electrolyte and the magnesium and an interface (28) between the electrolyte and the aluminum facilitates the automatic removal of the purified metals. Differences in surface tension in the fluid layers of a molten electrolytic salt (30) and a molten metal (29) produce different pressures as bubbles (57) evolved from vertically displaced tips (52) of tubes (34, 36) press against the liquid layers on either side of their interfaces (28, 32).

Abstract: An electrochemical synapse adapted for use in a neural network which includes an input terminal and an output terminal located at a distance of less than 100 microns from the input terminal. A permanent interconnect having controllable conductivity is located between the two inputs. The conductivity of the permanent interconnect is controlled by either growing or eliminating metallic whiskers between the inputs. The growth and elimination of whiskers provides a rapid and controllable electrochemical synapse. Partial neural network systems are disclosed utilizing the electrochemical synapse.

Abstract: A method for evaluating characteristics of a printed wiring board by measuring the alternating current impedance spectra of the printed wiring board conductor pattern. The method is useful in evaluating a number of different characteristics, such as moisture content, delamination, interlayer thickness and surface characteristics.

Abstract: An electrochemical capacitor (battery-capacitor) which provides high power density and rapid charging and discharging times ranging from a few milliseconds to a few seconds. The capacitor device includes at least one electrochemical cell having two electrodes and an electrolyte therebetween. The electrodes and electrolyte are capable of rapid redox kinetics with the electrodes being spaced apart by no more than 0.002 inch (5.08.times.10.sup.-3 cm) to thereby provide rapid charging and discharging times.