Abstract: A method for inhibiting corrosion, e.g., pitting corrosion, of alloys is provided. Particularly, the method comprises contacting at least a portion of a surface of the alloy with an aqueous solution comprising a salt of one or more rare earth elements selected from the group consisting of yttrium, gadolinium, cerium, europium, terbium, samarium, neodymium, praseodymium, lanthanum, holmium, ytterbium, dysprosium and erbium; and establishing a voltage differential between an anode comprising the alloy and a cathode in the solution at an effective level and for a sufficient period of time wherein a rare earth element oxide-containing coating is formed on the surface of the alloy to inhibit corrosion thereof.

Abstract: A methanol-air fuel cell consisting of a stack of sub-fuel cells, each sub-fuel cell comprising a proton conducting polymer membrane, with each membrane having an array of 1-cm2-anode unit cells on one side and an array of cathode unit cells on the other. A thin polymer film, with openings for the unit cells and plated with pre-patterned lines of electrical leads, is placed on each side of the membrane to collect the current from each unit cell. A polymer fuel-feed plate is placed on the thin polymer film on each side of the membrane to feed methanol and oxygen to the electrodes.

Abstract: A long-life conductivity sensor system and method that is embeddable or immersible in a medium. The conductivity sensor system includes at least a housing with an enclosing wall that defines an interior volume and that has at least one aperture through the wall; a pair of electrodes protruding through the aperture into a medium surrounding the sensor housing; and conductivity sensing electronics contained within the sensor housing interior volume and connected to the pair of electrodes. The conductivity sensing electronics include a galvanostat connected to the electrodes for inducing discrete constant current pulses between the electrodes creating a transient voltage signal between the electrodes; and a high-speed voltmeter/A-D Converter connected to the electrodes for measuring the transient voltage signal between the electrodes, the transient voltage signal being a function of the conductivity of the medium surrounding the sensor housing.

Abstract: Provided are methods of producing an electrode capable of binding an analyte thereto comprising: providing a substrate capable of binding a dithiol molecule thereto; electrochemically treating the substrate using cyclic voltammetry to provide a treated substrate having a fractal dimension of greater than about 2; and contacting the treated substrate with dithiol molecules to produce an electrode having dithiol groups attached thereto and capable of binding an analyte to be detected thereto. Also provided are methods of accumulating and detecting analytes using the electrodes produced via the methods of the present invention.

Abstract: A long-life conductivity sensor system and method that is embeddable or immersible in a medium. The conductivity sensor system includes at least a housing with an enclosing wall that defines an interior volume and that has at least one aperture through the wall; a pair of electrodes protruding through the aperture into a medium surrounding the sensor housing; and conductivity sensing electronics contained within the sensor housing interior volume and connected to the pair of electrodes. The conductivity sensing electronics include a galvanostat connected to the electrodes for inducing discrete constant current pulses between the electrodes creating a transient voltage signal between the electrodes; and a high-speed voltmeter/A-D Converter connected to the electrodes for measuring the transient voltage signal between the electrodes, the transient voltage signal being a function of the conductivity of the medium surrounding the sensor housing.

Abstract: Provided are methods of producing an electrode capable of binding an analyte thereto comprising: providing a substrate capable of binding a dithiol molecule thereto; electrochemically treating the substrate using cyclic voltammetry to provide a treated substrate having a fractal dimension of greater than about 2; and contacting the treated substrate with dithiol molecules to produce an electrode having dithiol groups attached thereto and capable of binding an analyte to be detected thereto. Also provided are methods of accumulating and detecting analytes using the electrodes produced via the methods of the present invention.

Abstract: The present invention concerns a sensor array and related testing apparatus for rapidly detecting the presence and/or concentration of constituents in samples, particularly biological molecules in fluid samples, including associated testing methods. The invention can be adapted such that a plurality of the sensors each detect a different constituent so that the invention can rapidly detect multiple constituents in a single sample. The sensors may be arranged in an array and connected by a plurality of micro channels that are fed from a main channel into which the sample is introduced. Positive pressure can be applied to the main and micro channels by a micro-pump. Alternately, it can be adapted to detect one or more constituents in a plurality of separate samples. A plurality of sensors are provided, each comprising electrochemical cells comprising an anode, a cathode and a reference electrode separated from each other by one or more filters within which an electrolyte is suspended.

Abstract: A method for inhibiting corrosion, e.g., pitting corrosion, of alloys is provided. Particularly, the method comprises contacting at least a portion of a surface of the alloy with an aqueous solution comprising a salt of one or more rare earth elements selected from the group consisting of yttrium, gadolinium, cerium, europium, terbium, samarium, neodymium, praseodymium, lanthanum, holmium, ytterbium, dysprosium and erbium; and establishing a voltage differential between an anode comprising the alloy and a cathode in the solution at an effective level and for a sufficient period of time wherein a rare earth element oxide-containing coating is formed on the surface of the alloy to inhibit corrosion thereof.

Abstract: A pH sensor system (10) and method capable of monitoring the pH level of a medium based on the characteristics of a chromatic pH sensitive material employed in the pH sensor system is provided. The pH sensor system includes at least a housing (12) having at least one transparent surface (14); a light sensitive circuitry (15), e.g., a LED (16) and photo-detector (18), enclosed within the housing; and, a chromatic pH sensitive material (20) overlaying at least a portion of the transparent surface having the characteristic of becoming saturated when an ambient pH level reaches a predetermined level such that the light sensitive circuitry detects a different intensity of incident light when the chromatic pH sensitive material is saturated than when the chromatic pH sensitive material is not saturated. As the pH level of the medium, e.g., concrete, storage tanks containing chemical reagents, etc.

Abstract: A method for detecting the onset of and/or monitoring the progress of localized corrosion of one or more locations on the surface of a corrodible metal article in a corrosive environment is provided which comprises the step of placing one or more magnetic field corrosion sensing devices, e.g., a magnetometer, in juxtaposition with the corrosive metal article, e.g., a steel rebar in concrete, such that the magnetic field corrosion sensing devices can effectively measure the magnetic fields associated with the localized corrosion of the locations on the surface of the corrodible metal article and determine the degree of localized corrosion occurring at the locations on the surface of the corrodible metal article being monitored.

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: A methanol-air fuel cell consisting of a stack of sub-fuel cells, each sub-fuel cell comprising a proton conducting polymer membrane, with each membrane having an array of 1-cm2-anode unit cells on one side and an array of cathode unit cells on the other. A thin polymer film, with openings for the unit cells and plated with pre-patterned lines of electrical leads, is placed on each side of the membrane to collect the current from each unit cell. A polymer fuel-feed plate is placed on the thin polymer film on each side of the membrane to feed methanol and oxygen to the electrodes.

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.