Abstract: A convection oven having multiple airflow patterns within a cooking chamber during a baking cycle. In one embodiment, at least one reversible blower wheel rotatable at varying speeds produces separate airflow states to create multiple airflow patterns within the cooking chamber during a baking cycle. In another preferred embodiment, at least one adjustable airflow control surface mounted within the cooking chamber creates multiple airflow patterns within the cooking chamber during the baking cycle.

Abstract: A method for reducing noise in borehole electromagnetic telemetry systems in which a signal receiver is positioned at a distance from a drill site borehole at which the signal receiver couples strongly to a signal from a signal transmitter disposed in the borehole and weakly to drill site noise emanating from the drill borehole, a noise receiver is positioned at a distance from the drill site borehole at which the noise receiver couples substantially only to magnetotelluric and/or drill site noise, the contributions of the magnetotelluric noise and drill site noise are determined, and subtracted from the signal received by the signal receiver, resulting in a reduced noise signal.

Abstract: A method and apparatus for generating electricity by direct oxidation of methanol in which methanol is passed through a porous anode current collector to contact the anode electrode of a polymer electrolyte membrane fuel cell, an oxidant is passed at atmospheric pressure through a porous cathode current collector which acts as an air diffuser to contact the cathode electrode and the methanol is directly oxidized, producing water which is removed through the cathode current collector, carbon dioxide and electricity.

Abstract: A method for producing regenerable sulfur sorbents in which a support material precursor is mixed with isopropanol and a first portion of deionized water at an elevated temperature to form a sol mixture. A metal oxide precursor comprising a metal suitable for use as a sulfur sorbent is dissolved in a second portion of deionized water, forming a metal salt solution. The metal salt solution and the sol mixture are mixed with a sol peptizing agent while heating and stirring, resulting in formation of a peptized sol mixture. The metal oxide precursor is dispersed substantially throughout the peptized sol mixture, which is then dried, forming a dry peptized sol mixture. The dry peptized sol mixture is then calcined and the resulting calcined material is then converted to particles.

Abstract: A method for monitoring sound in an in-ground pipeline via at least first and second in-ground acoustic sensors wherein the first in-ground acoustic sensor is in contact with the in-ground pipeline and the second in-ground acoustic sensor is spaced from both the first in-ground acoustic sensor and the in-ground pipeline.

Abstract: A method and apparatus for measuring the concentration of at least one gaseous component and/or vaporous component of a gaseous mixture in which a controlled sensor flame is introduced into the gaseous mixture and at least one narrow spectral band in the controlled sensor flame is optically measured. The concentration of the gaseous component using a result obtained from the optical measuring of the at least one narrow spectral band is then calculated. The method of this invention is particularly suitable for substantially real-time control of combustion processes.

Abstract: An earth boring apparatus at least partially locatable within a borehole. The apparatus includes a plurality of optical fibers, each of which has a proximal fiber light energy input end and a distal fiber light energy output end. At least one focal lens is disposed at the distal fiber light energy output end. The focal lens is made up of a plurality of focal elements, each of which corresponds to the distal fiber light energy output end of at least one optical fiber. The focal lens is arranged to receive light energy from the corresponding distal fiber light energy output end of the at least one optical fiber and focus it outwardly from the distal fiber light energy output end.

Abstract: A bi-polar separator plate constructed of a graphite/carbon composition and having a substantially flat peripheral sealing region on each face in which substantially flat peripheral sealing region a silicone gasket is disposed. The silicone gasket is applied to the bi-polar separator plate by a screen-printing process.

Abstract: A condensing heat exchanger structure in contact with a combustion environment and which structure includes a ferrous substrate is provided with a corrosion resistant diffusion coating applied to the ferrous substrate via a fluidized bed application. Also provided is a method for improving the corrosion resistance of a condensing heat exchanger structure which includes a ferrous substrate and a surface portion at least partially exposed to a combustion product-containing environment. In such method, a corrosion resistant diffusion coating is applied onto the ferrous substrate via a fluidized bed application.

Abstract: A method for locating gas leaks from underground gas pipelines in which a first acoustic sensor having a first signal output is positioned in ground disposed substantially above or at a distance from the underground gas pipeline. At least one second acoustic sensor having a second signal output is positioned in the ground at a plurality of locations substantially above the underground gas pipeline. The output signals from the acoustic sensors are measured for each location of the second acoustic sensor and the signals are adaptively filtered to remove common noise signal components. The statistical minima of these rms voltages are determined for both the first output signal and the adaptively filtered second output signals and the differences determined. The location of the second acoustic sensor corresponding to the largest positive said difference is the location closest to the leak site.

Abstract: A polymer electrolyte membrane fuel cell stack having a plurality of substantially planar fuel cell units, each of which comprises an anode electrode, a cathode electrode and a polymer electrolyte membrane disposed between the anode electrode and the cathode electrode. A metal bipolar plate is disposed between the anode electrode of one fuel cell unit and the cathode electrode of an adjacent fuel cell unit. The metal bipolar plate is made of a chromium-nickel austenitic alloy, in which the chromium and the nickel, on a combined basis, make up at least about 50% by weight of the alloy.

Abstract: An oven assembly having oppositely disposed first and second wall structures enclosing a cooking chamber, each wall structure having a plurality of spaced apart openings for passage of air therethrough. A rotating valve is provided, which is in heated air receiving communication and return air communication with a heat source and in heated air distributing communication with the first wall structure and in return air communication with the second wall structure whereby heated air is passed through the spaced apart openings in the first wall structure into the cooking chamber and return air from the cooking chamber is passed through the spaced apart openings in the oppositely disposed second wall structure and to the rotating valve for return to the heat source. The rotating valve is rotatable to be in heated air distributing communication with the second wall structure and in return air communication with the first wall structure.

Abstract: A method is disclosed for operating a gas-fired heater to maintain temperature within a zone. The gas-fired heater is modulated between a higher firing rate and a lower firing rate within a pseudo steady-state mode until a current firing rate exceeds a predetermined maximum time period ttrans. The gas-fired heater is then modulated between an updated higher firing rate and an updated lower firing rate within a transient mode until an updated current firing rate exceeds a predetermined maximum time period tdiag. Finally, the higher firing rate and the lower firing rate are redefined in a diagnostic mode until the gas-fired heater returns to the pseudo steady-state mode.

Abstract: A combustion system for automatic, real-time control of a combustion process which can be applied with significant advantage to a wide range of furnaces, boilers and combustors. The system includes a burner body having a primary first fluid inlet end forming at least one primary first fluid inlet and a first fluid outlet end forming at least one first fluid outlet. An inner conduit is disposed within the burner body, forming a fluid flow region between the burner body and the inner conduit. The inner conduit has a second fluid inlet distal from the first fluid outlet and a second fluid outlet proximate the first fluid outlet. An internal adjustment device is provided for adjusting a flow cross-sectional area for a first fluid and/or a second fluid disposed within the burner body.

Abstract: In a flame ionization sensor type gas combustion control apparatus, the sensor tip, or probe, exposed to the flame is constructed and arranged according to materials and shapes which promote mechanical deformation of the sensor due to thermal expansion and contraction. The mechanical deformation will cause cracks to open in the contaminant layers surrounding the probe, enabling the sensor to perform as intended even though insulative contaminant build up is present.

Abstract: An apparatus and method for detecting utilities buried in the ground wherein an array of sonic receivers are arranged in rows and ranks against the ground and a corresponding array of sonic transmitters are arranged relative to the array of sonic receivers so that a distance between each sonic transmitter and each adjacent sonic receiver is the same. Echoes generated by the apparatus may then be normalized, averaged and compared to the original echoes to develop a profile of the buried utility.

Abstract: A valve box having a metallic riser and a metallic lid covering a top of the metallic riser and an electromagnetic resonator coupled to the valve box interior facing side of the metallic lid, whereby, upon generation of an eddy current in the metallic lid, a current is generated in the electromagnetic resonator. This valve box, when buried, is readily locatable and identifiable by an above-ground interrogating device.

Abstract: A method and system for detecting an underground obstacle in which a plurality of acoustic signal sensors are deployed in a predetermined pattern on an area of ground defined by a guided drill path. A drill head of a drill is inserted into the ground and a borehole is drilled in the ground along the guided drill path. The noise signal generated by the drill head is detected at at least two of the acoustic signal sensors and the difference in arrival time of the noise signal at the two acoustic signal sensors is determined. This difference in arrival time of noise signal is analyzed, whereby the presence or absence of an underground obstacle is determined.

Abstract: An apparatus for combustion of a fuel in stages having at least one wall enclosing a chamber and forming at least one fuel inlet opening, at least one oxidant inlet opening and a plurality of fuel/oxidant outlet openings. A recirculation sleeve is disposed on the fuel/oxidant outlet side of the chamber and is coaxially aligned with the center axis of the apparatus. A plurality of fuel distributors are disposed within the chamber, each fuel distributor having a fuel inlet and a plurality of fuel outlets, each of the fuel outlets being aligned with a corresponding one of the fuel/oxidant outlet openings. Also disclosed is a method for combustion of a fuel in stages.

Abstract: A method and apparatus for combustion of a fuel in which a first-stage fuel and a first-stage oxidant are introduced into a combustion chamber and ignited, forming a primary combustion zone. At least about 5% of the total heat output produced by combustion of the first-stage fuel and the first-stage oxidant is removed from the primary combustion zone, forming cooled first-stage combustion products. A portion of the cooled first-stage combustion products from a downstream region of the primary combustion zone is recirculated to an upstream region of primary combustion zone. A second-stage fuel is introduced into the combustion chamber downstream of the primary combustion zone and ignited, forming a secondary combustion zone. At least about 5% of the heat from the secondary combustion zone is removed. In accordance with one embodiment, a third-stage oxidant is introduced into the combustion chamber downstream of the secondary combustion zone, forming a tertiary combustion zone.