Abstract: A DC power supply, a DC motor driven by DC voltage outputted from the DC power supply, and a control unit outputting a drive control signal to drive the DC motor are provided. A motor drive switch is provided between the DC power supply and the DC motor, and a brake switch is connected to a positive input terminal of the DC motor. The motor drive switch is on while receiving the drive control signal and outputs an output current monitor signal while current is being applied to the motor drive switch. The brake switch is configured to operate faster than the motor drive switch and is off while at least one of the drive control signal and the output current monitor signal is on. Accordingly, when the drive control signal is supplied, the brake switch is turned off, and then the motor drive switch is turned on.

Abstract: The invention relates to a direct current motor control circuit. The invention also relates to the use thereof in a windscreen wiper system for vehicles. An MOS FET transistor with an anti-parallel diode (M3) is serially mounted on the braking system (M2) of the control circuit.

Abstract: The invention relates to an electric driven tool device, especially an electric hand-held tool device, comprising an asynchronous electric motor (2) or a brush-less synchronous electric motor and a computer-controlled motor control device (8). The invention is characterized by a frequency converter (4) which can be controlled by the motor control device, whereby a motor (drive) voltage can be applied to the motor (2), and with a current detector (10) which co-operates with the motor control device (8) and detects the motor current. The motor control device (8) is embodied in such a manner that, in a first phase of the motor operation, the frequency of the motor current is maintained in a constant manner up to a limiting current I(grenz) and, in a second phase of the motor operation, at loads above the load at which the motor current reaches the limiting current I(grenz), the frequency of the motor current is lowered in such a manner that the motor current is maintained at a constant value.

Abstract: A controller writes position information (count value) of the window glass into an EEPROM based on halting of operation of a drive motor and identifies the current position of the window glass based on the position information of the window glass written in the EEPROM at the start of power supply. The controller determines whether the current position of the window glass has been lost or not at the start of power supply. Only when the controller determines that the current position of the window glass has been lost at the start of power supply, the controller shifts to a mode of performing relearning of the origin position for matching the position of the window glass with the position of the window glass corresponding to the position information written into the EEPROM.

Abstract: A drive arrangement for positioning a positioning element is disclosed that includes an electric servo motor for driving the positioning element, a potentiometer for presetting a setpoint, an actual value sensor disposed at the servo motor, and a motor driver with an integrated evaluation and control unit comparing the setpoint and actual value, whereby a pulse-shaped signal is superposed on the setpoint and the pulse-shaped signal exceeds the motor driver hysteresis in the evaluation and control unit.

Abstract: A pattern register stores an excitation pattern of stepping motors. A first pattern control unit reads out an excitation pattern for n bits from a predetermined address of a pattern register for supplying the same to an external motor driver. A second pattern control unit reads out an excitation pattern for the same n bits as in the first pattern control unit from a predetermined address of the pastern register and supplies the same to an external motor driver. An output control unit selectively outputs a first output mode for using the first pattern control means and the second pattern control means independently, or a second output mode for using them in an interlocked manner.

Abstract: A motor/generator unit in which a motor/generator and an invertor part are integrated and the wiring of a field circuit part for supplying current to a winding on a rotor is rationalized. In a motor/generator unit in which a motor/generator body part having a field winding supplied with electricity via brushes and current-controlled by a semiconductor control device controlled by a control circuit part and an invertor power circuit part controlled by the control circuit part has the invertor power circuit part and the control circuit part mounted thereto, the brushes are disposed between the field winding and the armature winding on one side and the control circuit part on the other and the semiconductor control device is mounted on a control circuit mounting part on which the control circuit part is mounted.

Abstract: A method and apparatus for stopping an AC motor that is controlling a load while detecting mechanical brake slippage of a mechanical brake for holding the load against movement includes a controller for decreasing torque-producing current commands from the drive while a speed regulator is commanding zero speed, sensing movement of the load while the speed regulator is commanding zero speed, detecting movement of the load past a pre-determined distance limit, and increasing torque to support the load and prevent further movement of the load. The controller will again decrease torque-producing current commands from the drive, and again checking for movement of the load, and upon sensing no load movement upon reaching zero torque, then shutting off the motor.

Abstract: A three-in-one AC servo drive includes a main console, a control module, a power module and a plurality of servo motors. A single drive can be connected to a plurality of motors. The power module and control module for the motors can be integrated to a single modular unit. Therefore, the redundant portion such as communication interface, display unit and I/O unit can be eliminated. The capacitor of the bus of the IGBT module can also be reduced, whereby the occupied space and cost can be reduced with less assembling time.

Abstract: A switched reluctance machine is energized by phase circuits with four active switches, for example MOSFETs, arranged in a bridge configuration. The switches are capable of conducting current in both a first direction and a second direction and are capable of operating as a diode. The direction of current flow through the phase winding is reversed when changing from motoring to generating and from generating to motoring. The ratings of the switches are set in accordance with the energy supply and energy return currents.

Abstract: The present invention relates to a system and method for harvesting ambient electromagnetic energy, and more particularly, to the integration of antennas and electronics for harvesting ubiquitous radio frequency (RF) energy, transforming such electromagnetic energy into electrical power, and storing such power for usage with a wide range of electrical/electronic circuits and modules.

Abstract: A battery charger and emergency power supply assembly includes a housing. A switch is positioned in the housing and electrically coupled to a power supply. At least one electrical plug outlet is mounted in the housing and electrically coupled to the switch. A battery charger is mounted within the housing and is electrically coupled to the power supply. Each of a plurality of charging ports extends into the housing and is electrically coupled to the battery charger. Each of a plurality of rechargeable batteries includes plug members adapted for electrically coupled to the charging ports. An inverter is electrically coupled to each of the charging ports. The inverter is also electrically coupled to the switch. The switch may selectively open a circuit between the plug outlet and the power supply or the plug outlet and the inverter.

Abstract: A portable battery charger for a mobile device having a rechargeable battery includes battery contacts, a switching regulator, and a charger interface. The battery contacts are configured to receive a battery having a low-voltage value. The switching regulator is coupled to the battery contacts and configured to draw the low-voltage value from the battery and convert the low-voltage value to a charger output. The charger interface is configured to electrically engage the mobile device and is further configured to couple the charger output from the switching regulator to the rechargeable battery in the mobile device.

Abstract: A sense amplifier adapted to amplify a voltage signal representative of a charging current provided to a rechargeable battery. The sense amplifier may include a p-type input sense amplifier and an n-type input sense amplifier, The p-type input sense amplifier may be enabled and the n-type input sense amplifier may be disabled if a battery voltage level of the rechargeable battery is less than an under voltage threshold level. The p-type input sense amplifier may be disabled and the n-type input sense amplifier may be enabled if the battery voltage level is greater than or equal to the under voltage threshold level. A related method and an electronic device having a sense amplifier consistent with an embodiment are also provided.

Abstract: An electric drive system having a power source which provides power to an electric motor through an electric motor control. Discharging of stored capacitor energy of a capacitor coupled between the power source and the electric motor controller is provided by controlling energy transfer from the capacitor to the electric motor.

Abstract: A wound field synchronous (WFS) dynamoelectric machine comprises: a rotor assembly; an exciter generator section comprising a stationary multiphase exciter stator winding for receiving excitation power from a multiphase alternating current (AC) source to generate an exciter stator magnetic field, a multiphase exciter rotor winding in the rotor assembly for generating multiphase AC excitation power as it cuts through the exciter stator magnetic field and a rotating rectifier assembly in the rotor assembly for converting the multiphase AC excitation power to direct current (DC) excitation power; a synchronous machine section comprising a DC main rotor winding in the rotor assembly for generating a main rotor magnetic field and a stationary multiphase main stator winding for receiving a multiphase AC control signal to generate a rotating main stator magnetic field that interacts with the main rotor magnetic field to rotate the rotor assembly; and an impedance that selectively connects one phase of the exciter st

Abstract: A constant voltage power supply circuit is provided with a constant voltage circuit part to convert an input voltage into a predetermined constant voltage, a first excessive current protection circuit part to control the constant voltage circuit part so as to reduce the output voltage while maintaining an output current that is output to a predetermined maximum value if the output current is greater than or equal to the predetermined maximum value when the output voltage is a rated voltage, and a second excessive current protection circuit part to control the constant voltage circuit part so as to reduce the output voltage and the output current and to output a short-circuit current if the output voltage decreases to a ground voltage when the output voltage is decreased to a predetermined value by the first excessive current protection circuit part. The second excessive current protection circuit part is disabled in response to a first test signal that is active.

Abstract: A voltage regulator includes a first and second amplifier stage, an output stage, and a variable zero circuit. The first amplifier stage is coupled to receive a reference voltage and introduces a first pole of the voltage regulator. The second amplifier stage is coupled to the first amplifier stage and introduces a second pole of the voltage regulator. The output stage is coupled to the second amplifier stage, has an output driver, and is coupled to provide an output voltage based on the reference voltage. The variable zero circuit is coupled to the first amplifier stage, the second amplifier stage, and the output stage. The variable zero circuit provides a zero to compensate for at least one of the first pole or the second pole of the voltage regulator based on a gate to source voltage of the output driver and a drain to source voltage of the output driver.

Abstract: A buck-boost converter includes: a buck converter section including a first switch, a first rectifier, and an inductor; a boost converter section sharing the inductor and including a second switch, a second rectifier, and a smoothing circuit; and a control circuit for generating and outputting a first driving signal for opening and closing the first switch and a second driving signal for opening and closing the second switch.

Abstract: An apparatus and method is arranged to dynamically adjust a pulse width (e.g., off-time pulse) associated with a switching device in a converter such as a buck converter, a boost converter, or a buck-boost regulator. A one-shot circuit is configured to dynamically initiate a pulse cycle for the switching converter when the output voltage collapses to a level that is related to a monitored inductor current in the converter. By changing the start time associated with the one-shot circuit, the pulse-width (e.g., off-time pulse) associated with the switching device is varied. In one example, the one-shot circuit is triggered when the inductor current is sensed as decaying below a threshold. The one-shot circuit can be further arranged to have another pulse-width (e.g., on-time pulse) that is adjusted for phase alignment with a reference frequency using a PLL circuit.

Abstract: An apparatus and method for measuring output current and power in real-time is provided for a CPU core powered by a DC-to-DC power converter having active voltage positioning. In an embodiment of the invention, a switched mode power converter comprises at least one power switch operatively coupled to an input voltage source, an output filter operatively coupled to the at least one power switch to provide an output voltage and output current to a load, and a control circuit coupled to the at least one power switch. The control circuit activates the power switch with a duty cycle controlled to regulate at least one of the output voltage and the output current. The control circuit receives a first control signal defining a desired value for the output voltage, a second control signal defining a relationship between voltage input and current draw for the load, and a voltage sense signal corresponding to an actual value of the output voltage. The control circuit thereby provides a measurement of load current.

Abstract: A constant-current circuit and a system power source using this constant-current circuit are disclosed, which can generate plural highly accurate constant currents and supply them as bias currents by reducing variations caused by a change of a manufacturing process and a change of temperature. An operational amplification circuit AMP controls the operation of PMOS transistors M1 and M2 so that negative feedback is applied to a variation of one of currents i1 and i2 flowing from the PMOS transistors M1 and M2 and the variation is canceled.

Abstract: The present invention provides a band gap type reference voltage generating circuit and a semiconductor integrated circuit having the same, capable of generating a reference voltage of about 1.2V or less whose temperature dependency is low, and realizing reduced offset voltage dependency of a differential amplifier. A band gap part has: a first resistor and a first bipolar transistor connected in series between power supply voltage terminals; a second resistor, a second bipolar transistor, and a third resistor connected in series between the power supply voltage terminals; and a differential amplifier that receives voltages generated by the first and second resistors, and an output of the differential amplifier is applied to the bases of the two transistors.

Abstract: A novel method is described that enables the measurement of the phase of the spectral components generated by an harmonic phase reference generator without using a calibrated sampling oscilloscope. First one uses a vector network analyzer to measure the output reflection coefficient of an harmonic phase transfer standard and of the harmonic phase reference generator that needs to be characterized. Next one connects the transfer standard to a microwave receiver and one measures the spectral components that are generated by the transfer standard. One then connects the harmonic phase reference generator to be characterized to the microwave receiver. The spectral components of the harmonic phase reference generator to be characterized are calculated by using the spectrum of the transfer standard as measured by the receiver, the spectrum of the harmonic phase reference generator to be characterized as measured by the receiver and the known spectrum of the transfer standard.

Abstract: Delay-locked loops, signal locking methods and devices and system incorporating delay-locked loops are described. A delay-locked loop includes a forward delay path, a feedback delay path, a phase detector and a timer circuit. The forward delay path alternatively couples to an external clock signal and to an internal test signal. The phase detector adjusts a delay line based upon the phase differences of a feedback signal and the external clock signal. The timer circuit switches the test signal into the forward delay path and measures the time of traversal of the test signal around the forward delay path and the feedback delay path and generates a time constant for configuring the phase detector's update period. The phase detector is thereafter able to stabilize at an improved rate.

Abstract: Calculation of an offset value is permitted when a current value detected by an ammeter of a magnetic flux detection type is switched from a negative value to a positive value, or from a positive value to a negative value, and also a state where an absolute value of the current value is with in a predetermined range is continued for a predetermined time. When calculation of the offset value is permitted, the fact that an ignition switch is turned OFF is detected, and the current value detected by the ammeter is calculated as the offset value.

Abstract: A chuck adapted to test electrical and/or optical components on a device-under-test (DUT).

Abstract: Sorting handler for a burn-in tester including two DC testing parts and two unloading buffers on opposite sides of a burn-in board at a working post in a line with a main working line respectively, one pair of a loader part for supplying new devices and an unloader part for receiving tested good devices on each of side parts of a body, so that two insert/remove pickers carry out a work continuously in which two insert/remove pickers move along the main working line in both directions with reference to the burn-in board, to remove the devices from the burn-in board, and insert devices to be tested in the space in turn, thereby improving a test productivity per a unit time period.

Abstract: An exemplary hi-pot testing device (2) includes a testing table (20), a transfer table (21) movably supported on the testing table and configured to support a product (200) to be tested, and a hi-pot testing signal generator (27) under the testing table. The transfer table includes a top surface and a bottom surface, a first current input portion (23) at the bottom surface (202), a first power connector (234) embedded at the top surface, and electrically connecting to the first current input portion, and a first signal cable connector (25) arranged on the top surface. The first signal cable connector is grounded and configured to enable the product to be grounded. The hi-pot testing signal generator is configured to electrically connect with and electrically disconnect from the first current input portion of the transfer table.

Abstract: A magnetic linear position sensor comprises a first yoke which is made of soft magnetic material; a first magnet which is placed at the first yoke, and whose surface is the N-pole and is inclined; a second magnet which is placed at the first yoke, and whose surface is the S-pole and is inclined in a direction opposite to the surface of the first magnet and in a direction facing the surface of the first magnet; a second yoke which is placed at a position opposing the first magnet and the second magnet through an air gap and is made of soft magnetic material; and a magnetoelectric transducer which is placed in the air gap.

Abstract: Disclosed are a rotation angle detection device including: a stator provided with a one-phase excitation winding and two-phase output windings; and a rotor having salient poles, and a dynamo-electric machine using the same. The two-phase output windings are wound around a plurality of teeth of the stator, and respective numbers of turns of the two-phase output windings are obtained by using m-phase windings (m is an integer of 3 or more) imaginarily defined to convert the numbers of turns of the m-phase windings into those of two-phase windings. Thus, since the number of phases decreases compared with the case in which the windings are structured with m phases, a structure is simplified, and a manufacturing process is facilitated.

Abstract: A magnetic rotational position sensor including first and second magnets spaced apart to define an air gap and cooperating with one another to generate a magnetic field within the air gap extending along an axis of rotation. At least one magnetic flux sensor is positioned within the magnetic field and is operable to sense varying magnitudes of magnetic flux in response to relative rotational movement between the magnetic field and the magnetic flux sensor about the axis of rotation.

Abstract: A pulse signal generator using a magnetic device that can cause a large Barkhausen effect, comprises means having a number of pits and projections and generates pulses according to the behavior of these, the means being capable of moving the pits and projections in a first or second direction, the pits and projections being disposed in the moving direction with some of the projections missing or some of the pits filled. The value of the ratio between the time interval of pulses generated by portions other than a projection-missing portion and the time interval of pulses generated by the projection-missing portion or the value of the ratio between the time interval of pulses generated by portions other than a pit-filled portion and the time interval of pulses generated by the pit-filled portion differs between when the pits and projections move in the first or second direction.

Abstract: Conductive wires run parallel to each other and connect a Hall element and an ECU. The conductive wire includes an extracting part and a wiring part. The extracting part runs along a surface of a base, on which the Hall element is positioned, and in a direction of a sensitivity of the Hall element. The wiring part extends from the extracting part and runs near a rotating crankshaft in an axial direction of the crankshaft. Similar to the conductive wire, the conductive wire includes an extracting part and a wiring part. Conductive wires run parallel to each other and connect a Hall element and the ECU. The conductive wires include an extracting part and a wiring part, and an extracting part and a wiring part, respectively.

Abstract: A flexible elongate structure, such as a flexible riser (10), comprising at least one layer (20) of steel wires near the surface which extend at least partly along the length of the structure, can be monitored by inducing a small, alternating magnetic field in the steel wires using an electromagnetic coil, and monitoring the magnetic flux density near the surface of the structure so as to asses the stress and hence detect if any wires have broken. By using an array of stress-measuring electromagnetic probes (24) around the structure some spatial resolution can be provided as to the location of any break in the wires.

Abstract: A scanning SQUID microscope is set forth to provide improved output imaging. The SQUID microscope includes a vertically adjustable housing adapted to securely retain a SQUID loop or sensor. A scanning stage of the SQUID microscope is adapted to support a sample while moving the sample along a predetermined path to selectively position predetermined portions of the sample in close proximity to the SQUID loop or sensor to permit the loop or sensor to detect predetermined magnetic field information provided by the predetermined portions of the sample. A position control processor coupled to the scanning stage is operative to receive and process the predetermined magnetic field information to provide corresponding position noise information. Criteria are also presented for determining the expected level of position noise under given experimental conditions.

Abstract: A device for detecting magnetic fields, of the type comprising at least one element made of hard 5 magnetic material (12) and an element made of soft magnetic material (13) associated an element made of semiconductor material (11), electrodes (15) for forcing a current (I) in the semiconductor material (11), characterised in that the element made of hard magnetic material (12) and element made of soft magnetic material (13) are positioned in planar fashion on the element made of semiconductor material (11).

Abstract: A magnetism detecting device includes a magnetometric sensor, a bias magnetic field generating unit, a voltage applying unit, a detecting unit, and an operating unit. The detecting unit calculates a first output corresponding to a difference between two voltage values each corresponding to the positive and negative bias magnetic fields, and the positive voltage; and a second output corresponding to a difference between two voltage values each corresponding to the positive and negative bias magnetic fields, and the negative voltage. The detecting unit eliminates an offset voltage included in the first output and the second output by taking difference between the first output and the second output.

Abstract: A magnetic sensor 10 includes GMR elements 11-18, and heating coils 21-24 serving as heat generating elements. The elements 11-14 and 15-18 are bridge-interconnected to constitute X-axis and Y-axis sensors, respectively. The heating coils 21, 22, 23, and 24 are disposed adjacent to the elements 11 and 12, the elements 13 and 14, the elements 15 and 16, and the elements 17 and 18, respectively. The heating coils 21-24, when electrically energized, heat mainly the adjacent elements. Therefore, the elements can be heated and cooled in a short period of time in which constant geomagnetism can be ensured. Data for compensation of temperature-dependent characteristic (ratio of change in sensor output value to variation in element temperature) is obtained on the basis of the temperatures of the elements before and after the heating, and the magnetic sensor outputs before and after the heating. Subsequently, the temperature characteristics of the elements are compensated on the basis of the data.

Abstract: Methods and systems for spatially resolved spin resonance detection in a sample of material are disclosed. Also disclosed are methods and systems for spatially resolved impedance measurements in a sample of material. The disclosed methods and samples can be used in screening of plurality of biological, chemical and material samples.

Abstract: An apparatus and method for compensating for the effect of tool motion in NMR MWD measurements. Signals obtained from a directionally sensitive receiver are compensated for the effects of tool motion. In an alternative embodiment, directional transmitters and receivers are used, with the pulsing of the transmitter controlled by the output of motion sensors. In another embodiment, the transmitters and receivers may be axisymmetric and the received signals are corrected using results of a NMR simulation program that takes account of the recorded motion of the apparatus.

Abstract: A system and method for acoustic noise reduction/cancellation is disclosed that includes a medical imaging scanner configured to scan an imaging subject within an imaging area that emits system noise when in operation. An ultrasonic emitter system is included that is constructed to emit an inaudible signal having properties to reduce perception of the system noise about at least a portion of the imaging area.

Abstract: EPR spectrometer comprising a ferroelectric single crystal resonator, a rectangular channel with holes in its narrow sides for inserting a sample and wires, a permanent magnet with planar poles, and a coil within the channel connected through the holes by the wires with a modulation source and a NMR spectrometer comprising a magnet, a probe with means for transmitting a radio frequency magnetic pulse and detecting NMR signal, and a ferroelectric single crystal resonator. A ferroelectric single crystal consisting essentially of potassium tantalate and the alkali metal substituting from about 1% to 3% of potassium or a group (V) metal substituting in part for tantalum, having cubic form of perovskite crystalline structure, and essentially free of impurities and defects is also disclosed.

Abstract: An antenna element for magnetic resonance applications has at least one sub-section that extends along a section axis and is adjacent to an auxiliary circuit. The antenna element has a coupling section and an auxiliary circuit section that is inductively coupled to the sub-section via the coupling section. The auxiliary circuit section extends parallel to the sub-section at a distance from the section axis. The auxiliary circuit has controllable tuning elements therein. Depending on their control state, a radio-frequency excitation current flowing in the sub-section causes, at respectively different times, each of a leading auxiliary current, or a lagging auxiliary current, or no auxiliary current to flow in the auxiliary current section.

Abstract: A method for estimating a value of a diffusion tensor includes obtaining, from a plurality of test subjects, DT-MRI data from which an initial estimate of the tensor can be derived. Values indicative of int-subject variation and inter-subject variation in the data are then determined. These values are used to determine a subject-specific additive offset for adjusting the DT-MRI data.

Abstract: A Toroid Cavity Detector (TCD) is provided for implementing nuclear magnetic resonance (NMR) studies of chemical reactions under conditions of high pressures and temperatures. A toroid cavity contains an elongated central conductor extending within the toroid cavity. The toroid cavity and central conductor generate an RF magnetic field for NMR analysis. A flow-through capillary sample container is located within the toroid cavity adjacent to the central conductor to subject a sample material flowing through the capillary to a static magnetic field and to enable NMR spectra to be recorded of the material in the capillary under a temperature and high pressure environment.

Abstract: Magnet assembly for use in medical magnetic resonance imaging includes means for increasing flux generation in the gap region to provide the capability of scanning smaller volume regions of a patient at increased levels of scanning resolution. The means for increasing flux generation is mechanical or electromagnetic, is coupled to each of the polar regions and maintains the gap region sufficiently large and unobstructed to allow for access to the patient by several persons during scanning. Tapered outer walls of the polar region proximate the gap region further enhance accessibility to the patient during scanning.

Abstract: An RF coil suitable for use in imaging systems is provided which coil has a dielectric filled cavity formed by a surrounding conducting enclosure, the conducting enclosure preferably being patterned to form continuous electrical paths around the cavity, each of which paths may be tuned to a selected resonant frequency. The patterning breaks up any currents induced in the coil and shortens path lengths to permit higher frequency, and thus higher field strength operation. The invention also includes improved mechanisms for tuning the resonant frequency of the paths, for selectively detuning the paths, for applying signal to the coil, for shortening the length of the coil and for controlling the field profile of the coil and the delivery of field to the object to the image.

Abstract: A multicomponent induction logging tool includes a transmitter antenna and two receiver antennas, one of which is aligned parallel to the transmitter. Using measurements made at a plurality of rotational angles, a misalignment angle between the transmitter antenna and the second receiver antenna is estimated.

Abstract: An improved induction tool for formation resistivity evaluations. The tool provides electromagnetic transmitters and sensors suitable for transmitting and receiving magnetic fields in radial directions that are orthogonal to the tool's longitudinal axis with minimal susceptibility to errors associated with parasitic eddy currents induced in the metal components surrounding the transmitter and receiver coils. Various transmitter receiver combinations are provided to select sensitivity to a desired reservoir formation properties, for example, different orientations xy, xz, yz, 20-40, 20-90, and combinations, such as, Symmetric-symmetric; Asymmetric-symmetric; and Asymmetric-asymmetric. Measurements made with a multi-component logging instrument when used in a substantially horizontal, vertical or deviated borehole in earth formations are diagnostic of the direction of resistive beds relative to the position of the borehole.