Abstract: Presented herein are methodologies for generating clock signals for transceivers that rely on frequency and phase error correction functions. The methodology includes generating a differential clock signal at a fundamental frequency, generating, based on the differential clock signal and using a multiphase generator, four quadrature signals at the fundamental frequency, supplying the four quadrature signals to an injection-locked phase rotator, and outputting, from the injection-locked phase rotator, a phase adjusted multiphase clock signal based on the four quadrature signals.

Abstract: Presented herein are methodologies for generating clock signals for transceivers that rely on frequency and phase error correction functions. The methodology includes generating a differential clock signal at a fundamental frequency, generating, based on the differential clock signal and using a multiphase generator, four quadrature signals at the fundamental frequency, supplying the four quadrature signals to an injection-locked phase rotator, and outputting, from the injection-locked phase rotator, a phase adjusted multiphase clock signal based on the four quadrature signals.

Abstract: Thermal tuning and quadrature control of opto-electronic devices using active extinction ratio tracking is proved by phase shifting, via a first phase shifter, a first optical signal carried on a first arm of an interferometer relative to a second optical signal carried on a second arm of the interferometer; combining the first optical signal with the second optical signal as an output signal; detecting a peak value in the output signal; and adjusting a relative phase offset imparted by the first phase shifter on the first optical signal relative to the second optical signal, based on the peak value, to increase an amplitude of the peak value. In various embodiments, the peak value is increased over time to maximize an extinction ratio of the optoelectronic device and maintain the extinction ratio in a maximized state during operation.

Abstract: Active relative intensity noise mitigation in nested interferometers using trans-impedance amplifiers is provided by splitting an optical carrier signal into a first version and a second version, wherein the first version is orthogonal to the second version; re-combining predefined portions of the first version and the second version to determine a noise level; modulating at least one of the first version and the second version based on the noise level to reduce the noise level; after modulating the at least one of the first version and the second version based on the noise level, encoding data onto at least one of the first version and the second version; and recombining the first version and the second version to transmit the data.

Abstract: An example clock generator circuit includes a fractional reference generator configured to generate a reference clock in response to a base reference clock and a phase error signal, the reference clock having a frequency that is a rational multiple of a frequency of the base reference clock. The clock generator circuit includes a digitally controlled delay line (DCDL) that delays the reference clock based on a first control code, and a pulse generator configured to generate pulses based on the delayed reference clock. The clock generator circuit includes a digitally controlled oscillator (DCO) configured to generate an output clock based on a second control code, the DCO including an injection input coupled to the pulse generator to receive the pulses.

Abstract: Provided herein are methods and devices to enrich trace quantities of impurities in gaseous mixtures, such as hydrogen fuel. The methods and devices rely on concentration of impurities so as to allow the detection of the impurities using commonly-available detection methods.

Abstract: Provided herein are methods and devices to enrich trace quantities of impurities in gaseous mixtures, such as hydrogen fuel. The methods and devices rely on concentration of impurities so as to allow the detection of the impurities using commonly-available detection methods.

Abstract: Provided herein are batch methods and devices for enriching trace quantities of impurities in gaseous mixtures, such as hydrogen fuel. The methods and devices rely on concentrating impurities using hydrogen transport membranes wherein the time period for concentrating the sample is calculated on the basis of optimized membrane characteristics, comprising its thickness and permeance, with optimization of temperature, and wherein the enrichment of trace impurities is proportional to the pressure ratio Phi/Plo and the volume ratio V1/V2, with following detection of the impurities using commonly-available detection methods.

Abstract: Provided herein are methods and devices to enrich trace quantities of impurities in gaseous mixtures, such as hydrogen fuel. The methods and devices rely on concentration of impurities so as to allow the detection of the impurities using commonly-available detection methods.

Abstract: A method for preparing compositionally graded metallic plates and compositionally graded metallic plates suitable for use as interconnects for solid oxide fuel cells are provided. The method of the invention, utilizing powder metallurgy, enables making metallic plates of generally any desired composition to meet the corrosion requirements of fuel cells and other applications, and enables making metallic plates of graded composition from one surface of the plate to the other. A powder of the desired alloy composition is obtained, then solvents, dispersants, a plasticizer and an organic binder are added to form a slip. The slip is then formed into a layer on a desired substrate that can be flat or textured. Once dried, the layer is removed from the substrate and the binder is burned out. The layer is sintered in a reducing atmosphere at a set temperature for a predefined duration specific to the materials used and the desired final properties.

Abstract: A solid oxide fuel cell (SOFC) repeat unit includes an oxide electrolyte, an anode, a metallic fuel flow field, a metallic interconnect, and a metallic air flow field. The multilayer laminate is made by casting tapes of the different functional layers, laminating the tapes together and sintering the laminate in a reducing atmosphere. Solid oxide fuel cell stacks are made by applying a cathode layer, bonding the unit into a gas manifold plate, and then stacking the cells together. This process leads to superior mechanical properties in the SOFC due to the toughness of the supporting metallic layers. It also reduces contact resistances in stacking the cells since there is only one physical contact plane for each repeat unit.

Abstract: A method for preparing compositionally graded metallic plates and compositionally graded metallic plates suitable for use as interconnects for solid oxide fuel cells are provided. The method of the invention, utilizing powder metallurgy, enables making metallic plates of generally any desired composition to meet the corrosion requirements of fuel cells and other applications, and enables making metallic plates of graded composition from one surface of the plate to the other. A powder of the desired alloy composition is obtained, then solvents, dispersants, a plasticizer and an organic binder are added to form a slip. The slip is then formed into a layer on a desired substrate that can be flat or textured. Once dried, the layer is removed from the substrate and the binder is burned out. The layer is sintered in a reducing atmosphere at a set temperature for a predefined duration specific to the materials used and the desired final properties.

Abstract: A method of forming a hydrogen rich gas from a source of hydrocarbon fuel. A vapor of the hydrocarbon fuel and steam is brought in contact with a two-part catalyst having a dehydrogenation powder portion and an oxide-ion conducting powder portion at a temperature not less than about 770°C. for a time sufficient to generate the hydrogen rich. The H2 content of the hydrogen gas is greater than about 70 percent by volume. The dehydrogenation portion of the catalyst includes a group VIII metal, and the oxide-ion conducting portion is selected from a ceramic oxide from the group crystallizing in the fluorite or perovskite structure and mixtures thereof. The oxide-ion conducting portion of the catalyst is a ceramic powder of one or more of ZrO2, CeO2, Bi2O3, (BiVO)4, and LaGaO3.

Abstract: A partial oxidation reformer comprising a longitudinally extending chamber having a methanol, water and an air inlet and an outlet. An igniter mechanism is near the inlets for igniting a mixture of methanol and air, while a partial oxidation catalyst in the chamber is spaced from the inlets and converts methanol and oxygen to carbon dioxide and hydrogen. Controlling the oxygen to methanol mole ratio provides continuous slightly exothermic partial oxidation reactions of methanol and air producing hydrogen gas. The liquid is preferably injected in droplets having diameters less than 100 micrometers. The reformer is useful in a propulsion system for a vehicle which supplies a hydrogen-containing gas to the negative electrode of a fuel cell.

Abstract: A two-part catalyst comprising a dehydrogenation portion and an oxide-ion conducting portion. The dehydrogenation portion is a group VIII metal and the oxide-ion conducting portion is selected from a ceramic oxide crystallizing in the fluorite or perovskite structure. There is also disclosed a method of forming a hydrogen rich gas from a source of hydrocarbon fuel in which the hydrocarbon fuel contacts a two-part catalyst comprising a dehydrogenation portion and an oxide-ion conducting portion at a temperature not less than about 400.degree. C. for a time sufficient to generate the hydrogen rich gas while maintaining CO content less than about 5 volume percent. There is also disclosed a method of forming partially oxidized hydrocarbons from ethanes in which ethane gas contacts a two-part catalyst comprising a dehydrogenation portion and an oxide-ion conducting portion for a time and at a temperature sufficient to form an oxide.

Abstract: A partial oxidation reformer comprising a longitudinally extending chamber having a methanol, water and an air inlet and an outlet. An igniter mechanism is near the inlets for igniting a mixture of methanol and air, while a partial oxidation catalyst in the chamber is spaced from the inlets and converts methanol and oxygen to carbon dioxide and hydrogen. Controlling the oxygen to methanol mole ratio provides continuous slightly exothermic partial oxidation reactions of methanol and air producing hydrogen gas. The liquid is preferably injected in droplets having diameters less than 100 micrometers. The reformer is useful in a propulsion system for a vehicle which supplies a hydrogen-containing gas to the negative electrode of a fuel cell.

Abstract: A partial oxidation reformer comprising a longitudinally extending chamber having a methanol, water and an air inlet and an outlet. An igniter mechanism is near the inlets for igniting a mixture of methanol and air, while a partial oxidation catalyst in the chamber is spaced from the inlets and converts methanol and oxygen to carbon dioxide and hydrogen. Controlling the oxygen to methanol mole ratio provides continuous slightly exothermic partial oxidation reactions of methanol and air producing hydrogen gas. The liquid is preferably injected in droplets having diameters less than 100 micrometers. The reformer is useful in a propulsion system for a vehicle which supplies a hydrogen-containing gas to the negative electrode of a fuel cell.

Abstract: A method of forming a hydrogen rich gas from a source of hydrocarbon fuel in which the hydrocarbon fuel contacts a two-part catalyst comprising a dehydrogenation portion and an oxide-ion conducting portion at a temperature not less than about 400.degree. C. for a time sufficient to generate the hydrogen rich gas while maintaining CO content less than about 5 volume percent. There is also disclosed a method of forming partially oxidized hydrocarbons from ethanes in which ethane gas contacts a two-part catalyst comprising a dehydrogenation portion and an oxide-ion conducting portion for a time and at a temperature sufficient to form an oxide.

Abstract: A propulsion system for a vehicle having pairs of front and rear wheels and a fuel tank. An electrically driven motor having an output shaft operatively connected to at least one of said pair of wheels is connected to a fuel cell having a positive electrode and a negative electrode separated by an electrolyte for producing dc power to operate the motor. A partial oxidation reformer is connected both to the fuel tank and to the fuel cell receives hydrogen-containing fuel from the fuel tank and water and air and for partially oxidizing and reforming the fuel with water and air in the presence of an oxidizing catalyst and a reforming catalyst to produce a hydrogen-containing gas. The hydrogen-containing gas is sent from the partial oxidation reformer to the fuel cell negative electrode while air is transported to the fuel cell positive electrode to produce dc power for operating the electric motor.

Abstract: Apparatus for analyzing aerosols in essentially real time includes a virtual impactor which separates coarse particles from fine and ultrafine particles in an aerosol sample. The coarse and ultrafine particles are captured in PTFE filters, and the fine particles impact onto an internal light reflection element. The composition and quantity of the particles on the PTFE filter and on the internal reflection element are measured by alternately passing infrared light through the filter and the internal light reflection element, and analyzing the light through infrared spectrophotometry to identify the particles in the sample.