Abstract: A linear motor compressor including a compressor housing and a cylinder housing having a plurality of opposing compression chambers. A piston freely reciprocates within the cylinder housing using a linear electric motor.

Abstract: Methods for inferentially determining various properties of a gas mixture, when the speed of sound in the gas is known at an arbitrary temperature and pressure. The method can be applied to natural gas mixtures, where the known parameters are the sound speed, temperature, pressure, and concentrations of any dilute components of the gas. The method uses a set of reference gases and their calculated density and speed of sound values to estimate the density of the subject gas. Additional calculations can be made to estimate the molecular weight of the subject gas, which can then be used as the basis for heating value calculations. The method may also be applied to inferentially determine density and molecular weight for gas mixtures other than natural gases.

Abstract: An apparatus for rerounding plastic pipe includes a housing having a pipe passage extending therethrough. The housing has a moveable outer frame top positionable between an open position and a closed position to enclose a pipe to be rerounded. A pair of opposing jaws are positioned within the housing and on opposite sides of the pipe passage and have a generally symmetrical configuration with respect to one another. A drive mechanism is connected with respect to at least one of the jaws for compressing the jaws with respect to each other resulting in compression of the pipe to be rerounded.

Abstract: A gas sensor, whose chamber uses filters and choppers in either a semicircular geometry or annular geometry, and incorporates separate infrared radiation filters and optical choppers. This configuration facilitates the use of a single infrared radiation source and a single detector for infrared measurements at two wavelengths, such that measurement errors may be compensated.

Abstract: A composite piezoelectric transducer, whose piezoeletric element is a “ribbon wound” film of piezolectric material. As the film is excited, it expands and contracts, which results in expansion and contraction of the diameter of the entire ribbon winding. This is accompanied by expansion and contraction of the thickness of the ribbon winding, such that the sound radiating plate may be placed on the side of the winding.

Abstract: A system for generating electricity which includes an internal manifold fuel cell stack having an anode fuel gas duct, an anode exhaust gas duct, a cathode air duct and a cathode exhaust duct and a plenum having a fuel gas inlet, an anode exhaust gas outlet, an air inlet and a cathode exhaust gas outlet, which plenum is adapted to deliver a fuel gas and air to the internal manifold fuel cell stack. At least one air preheat panel is provided having two parallel planar surfaces disposed proximate and parallel to the internal manifold fuel cell stack and forming at least one air duct between the two parallel planar surfaces, which at least one air duct extends parallel to the two planar surfaces and has at least one cold air inlet and at least one preheated air outlet. The preheated air outlet is in fluid communication with the cathode air duct. In accordance with one embodiment, the internal manifold fuel cell stack, plenum and the at least one air preheat panel are all disposed within a housing.

Abstract: A ventilation system for removing cooking effluents and combustion products from an exhaust of a cooking appliance. The ventilation system includes a ventilation hood having an air inlet and an exhaust gas outlet disposed over the cooking appliance, a water bath disposed in the ventilation hood between the air inlet and the exhaust outlet, and an effluent removal assembly disposed above the water bath. The cooking effluents in contact with the effluent removal assembly are transferred to the surrounding water, and the clean airflow may be recirculated. Grease particles are also transferred to the surrounding water.

Abstract: A dual conveyor jet impingement oven having a blower box with at least one air inlet opening and at least two air outlet openings and a heating space adjacent to and in fluid communication with the blower box. Disposed within the heating space are two spaced apart pairs of spaced apart heated air distribution plenums, which form a central return air conduit therebetween. The central return air conduit has a return air outlet end in fluid communication with the blower box and the spaced apart heated air distribution plenums have a heated air inlet opening in fluid communication with the at least two air outlet openings. A horizontal heating surface is disposed between each pair of spaced apart heated air distribution plenums, each of which has a perforated heated air distribution plate facing the horizontal heating surface.

Abstract: A method for demodulation of a phase shift keyed signal in which the phase shift keyed signal is converted into a plurality of successive outputs, each of which is representative of a phase and amplitude of the phase shift keyed signal over additional sets of windows and carrier phases. Each said additional set has a different offset in time and carrier phase from the other additional sets of windows and carrier phases. The carrier phase and window offsets of the phase shift keyed signal are estimated using the plurality of successive outputs. The phase shift keyed signal is then decoded back into digital data using the estimates.

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 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 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: 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: 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 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: This specification discloses a method and apparatus for the mobile and remote detection of a gas, such as methane, in the atmosphere. The apparatus includes a TDL based Light Detection and Ranging (LIDAR) driven at carrier frequency lying within the absorption line of the gas. The apparatus also drives the TDL with a modulation frequency to generate upper and lower sidebands in the output of the TDL and with a low ramp frequency to sweep the output of the TDL across twice the width of the pressure-broadened absorption line of the gas, preferably the first overtone absorption line in the case of methane detection. The apparatus include reference and calibration cells or chambers, and includes a light collector and detectors to detect the quantity and modulation of the light that passes the reference or calibration cells and that is received by the apparatus after reflection back toward the apparatus from an uncooperative target.

Abstract: A method for monitoring an in-ground pipeline by detecting an occurrence of a contact with an in-ground pipeline via an acoustic sensor employing a first selected detection parameter and a second sensor employing a second selected detection parameter, which is different from the first selected detection parameter. The locations of the acoustic sensor and the second sensor are known and the input signals from the sensors arrive at a processor at different times and at known respective speeds such as to permit a determination of the point of contact with the in-ground pipeline.

Abstract: An apparatus for measuring and detecting a magnetic signature of a magnetically detectable object from a distance includes a portable sensor group for detecting the magnetic signature. The portable sensor group includes three gradient sensors, each of the three gradient sensors adapted to independently measure both a magnitude and a direction of the magnetic signature, a first of said gradient sensors measuring an axial gradient in the vertical direction, a second of said gradient sensors measuring a first horizontal gradient in the vertical direction, and a third of said gradient sensors measuring a second horizontal gradient in the vertical direction.