Abstract: A battery health monitor (BHM) that operates as a battery-mountable full-spectrum alternating current (ac) impedance meter that facilitates monitoring a state-of-charge and a state-of-health of a battery. The BHM is used for monitoring one or more electrical parameters, e.g., impedance, of a battery. The BHM includes: a current sink coupled to the first terminal and configured to sink therefrom an oscillatory current so as to cause the battery to produce at a first terminal thereof an oscillatory voltage equal to or less than a dc operating voltage of the battery that would be present at the first terminal in the absence of the oscillatory current; and a voltage sensor configured to sense the oscillatory voltage at the first terminal.

Abstract: Numerical techniques such as the finite element method (FEM) are used to model the current and voltage distribution in concrete structures such as bridges. The geometric arrangement of groundbeds and the ideal locations for the electrical contacts vis-a-vis the geometry of the bridge and the rebars can thereby be predicted and a cathodic protection (CP) system for the bridge designed. A magnetic sensor is used to sense the magnetic field generated by the CP current, and a voltmeter or an oscilloscope to measure the output of the magnetic sensor. A current interrupter is also used to interrupt the CP current at the source. The current is mapped by placing the magnetic sensor on or above the concrete surface. By moving the sensor from one location to another, the current is mapped over the entire structure. To achieve uniform distribution over the entire structure, an “expert” CP system controlled by a variety of current and environmental sensors and a dedicated microprocessor is described.

Abstract: The invention is directed to an apparatus and method for locating objects in a body through the mapping and imaging of the conductivity profiles of such objects by applying a force to the object and/or body and measuring certain characteristics of the body responsive to the application of force. In accordance with a preferred embodiment, the force applied to the object and body is in the form of an electrical voltage or current such that electrical potentials, currents, and magnetic fields are generated throughout the subsurface site. The voltage, current, or magnetic field is then measured at the surface or the boundary of the body. An estimate of subsurface conductivity is then made and a conductivity profile generated by minimizing a loss function. Preferably, the loss function is in the form of the sum square of the differences between measurement values and a set of computed values based on a gradient approximation technique.

Abstract: The invention is a process for making sharp tips. A computer controlled instrument and process characterizes the tip while in formation and reliably produces tips having a radius of curvature of approximately 100 nm. In the invention, the position of the wire during the etching operation is mechanically controlled while the etching current is monitored. When the current reaches a predetermined level, the process is halted.