Abstract: A free piston Stirling engine, comprising a power piston fitted into a cylinder further includes: a support structure carrying moving magnets for a linear alternator; and a passive structure that at normal operating power and frequency produces a restoring force on the piston in the absence of contact with the cylinder. In one variation, the passive structure further comprises a mass suspended within the piston from at least one spring, such that the mass oscillates under influence of movement of the piston at normal operating power and frequency so as to produce the restoring force. In another variation, the passive structure further comprises: a magnet disposed outside the cylinder at a position and in an orientation to produce a field that opposes a field of a moving magnet carried by the support structure when the piston moves toward the magnet.

Abstract: A system includes an optical sensor and a signal processing module. The optical sensor is configured to be positioned on an area of skin of a patient. The optical sensor includes a light source for illuminating a capillary bed in the area of skin and a photodetector. The photodetector is configured to receive an optical signal from the capillary bed resulting from the illumination and to convert the optical signal into an electrical signal, the optical signal characterizing a fluctuation in a level of blood in the capillary bed. The signal processing module is configured to process the electric signal using a nonstationary frequency estimation method to obtain a processed signal related to at least one of a heart rate and a respiration rate of the patient. Another aspect relates to obtaining a quantity related to the blood pressure of the patient in addition to or instead of obtaining a processed signal related to at least one of the heart rate and the respiration rate of the patient.

Abstract: A method includes combining fumed silicon oxide with a metal to form silicon having an average particle size of less than approximately 100 nm. The silicon can be incorporated into an anode of a lithium ion cell.

Abstract: A composition having a formula LixMgyNiO2 wherein 0.9<x<1.3, 0.01<y<0.1, and 0.91<x+y<1.3 can be utilized as cathode materials in electrochemical cells. A composition having a core, having a formula LixMgyNiO2 wherein 0.9<x<1.3, 0.01<y<0.1, and 0.9<x+y<1.3, and a coating on the core, having a formula LiaCobO2 wherein 0.7<a<1.3, and 0.9<b<1.2, can also be utilized as cathode materials in electrochemical cells.

Abstract: A simple and robust variable coaxial capacitive sensor and detection method for monitoring the position of a rapidly reciprocating member such as a piston or displacer in a free piston Stirling engine. The coaxial capacitor of the present invention in a preferred embodiment thereof is configured to modulate capacitive electrode area rather than inter-electrode spacing and as a result a highly linear transfer function can be achieved. Also disclosed are detection methods which derive and process signals in connection with applications which have small sensor capacitance variations while suppressing stray capacitance error.

Abstract: A system is provided for balancing state of charge among plural series connected electrical energy storage units that includes a power converter that selectively couples to an individual storage unit of the a string of electrical energy storage units and transfers energy by bidirectionally between the individual storage unit and the string of storage units.

Abstract: A composition having a formula LixMgyNiO2 wherein 0.9<x<1.3, 0.01<y<0.1, and 0.91<x+y<1.3 can be utilized as cathode materials in electrochemical cells. A composition having a core, having a formula LixMgyNiO2 wherein 0.9<x<1.3, 0.01<y<0.1, and 0.9<x+y<1.3, and a coating on the core, having a formula LiaCobO2 wherein 0.7<a<1.3, and 0.9<b<1.2, can also be utilized as cathode materials in electrochemical cells.

Abstract: A system is provided for balancing state of charge among plural series connected electrical energy storage units that includes a power converter that selectively couples to an individual storage unit of the a string of electrical energy storage units and bidirectionally transfers energy between the individual storage unit and the string of storage units.

Abstract: A sensor system includes a first measurement subsystem including a driver and a measurement component. The measurement component includes a set of sensors for generating complimentary signals representing each of one or more characteristics. The complimentary signals representing a characteristic include related error components. The driver is configured to accept the complimentary signals for a characteristic and to determine a measurement value for the characteristic by combining the complimentary signals to reduce effects of the error components in the complimentary signals.

Abstract: A system and method of balancing state of charge among plural series connected electrical energy storage unit is provided. Individual storage units are selectively coupled by semiconductor switches for monitoring and balancing state of charge. When the state of charge of a selected unit is greater than a target state of charge, energy is transferred from the selected unit to the string of storage units, such that the state of charge of the selected unit converges toward the target state of charge. Conversely, when the state of charge of a selected unit is less than a target state of charge, energy is transferred from the string of storage units to the selected unit, such that the state of charge of the selected unit converges toward the target state of charge.

Abstract: A linear electrical machine may function as an alternator or a motor. Three annular magnets may be provided that move relative to a core. The magnets may all have a different magnetic orientation. Two magnets may have a north pole oriented in a direction parallel to an axis along which the magnets move relative to the core. Another magnet may have a north pole oriented in a direction perpendicular to the axis. The core may include a plurality of ferromagnetic core elements; and a support structure composed of a composite material defining plural spaces, each for receiving one of the plurality of core elements. The core may further include a core shield disposed on the support structure substantially following a perimeter of the support structure defining an opening through which a reciprocating element can pass.

Abstract: A simple and robust variable coaxial capacitive sensor and detection method for monitoring the position of a rapidly reciprocating member such as a piston or displacer in a free piston Stirling engine. The coaxial capacitor of the present invention in a preferred embodiment thereof is configured to modulate capacitive electrode area rather than inter-electrode spacing and as a result a highly linear transfer function can be achieved. Also disclosed are detection methods which derive and process signals in connection with applications which have small sensor capacitance variations while suppressing stray capacitance error.

Abstract: A body ventilation system for enhanced personal comfort. A gas distributor including a network of gas flow elements is disposed on a permeable substrate. The gas distributor defines at least one channel in fluid communication with the gas flow elements. The gas flow elements are configured to receive gas from a gas supply such that gas flows through the gas flow elements and exits to the channels substantially parallel to the surface of the permeable substrate. The gas from the gas supply may be conditioned. The permeable substrate may be a wicking material and may be a garment substrate. The gas distributor may be substantially incompressible. The gas flow elements may be selectively positioned to target the ventilation needs of a particular class of users.

Abstract: A control system for a Stirling engine including the use of a synchronous power converter (“SPC”) which is connected to the terminals of the alternator in a linear alternator/FPSE power system. According to the teachings of the present invention, the attached SPC is small and portable and further ensures that piston and displacer excursion within the system remain within design limits. The system and method are designed such that it is possible to adjust both the voltage amplitude and the waveform frequency at the terminals of the linear alternator. By controlling these operational aspects, both the speed and the range of travel associated with the piston and the displacer in the FPSE can be controlled.

Abstract: A system and method for determining and balancing state of charge among plural series connected electrical energy storage units is provided. State of change of a selected storage unit in a string of storage units is determined by (i) applying a non-dissipative load to the selected storage unit, resulting in an energy transfer between the selected storage unit and the string of electrical energy storage units through the non-dissipative load and (ii) determining the state of charge of the selected unit from voltage and current data of the selected storage unit resulting from the energy transfer. When the state of charge of the selected unit is different than a target state of charge, energy can be transferred between the selected unit and the string of storage units, such that the state of charge of the selected unit converges toward the target state of charge.

Abstract: A simple and robust variable coaxial capacitive sensor and detection method for monitoring the position of a rapidly reciprocating member such as a piston or displacer in a free piston Stirling engine. The coaxial capacitor of the present invention in a preferred embodiment thereof is configured to modulate capacitive electrode area rather than inter-electrode spacing and as a result a highly linear transfer function can be achieved. Also disclosed are detection methods which derive and process signals in connection with applications which have small sensor capacitance variations while suppressing stray capacitance error.

Abstract: Impingement style heat exchanger through which significant heat transfer improvements can be obtained. The heat exchanger of the present invention operates such that the bulk of heat transfer between the heat source and the working fluid occurs during the portion of the Stirling cycle in which the working fluid impinges upon the pressure vessel surface. Either or both of two heat exchanger configurations may be used. In a first, the impingement heat transfer occurs while the fluid is traveling in the forward direction and towards the expansion space in the vessel. In contrast, and in connection with the second configuration of the heat exchanger of the present invention, the impingement heat transfer occurs while the working fluid is traveling in the backward direction and toward the compression space of the vessel.

Abstract: The present invention provides compositions effective in decontaminating either biological pathogens or both chemical and biological pathogens. These compositions are particularly suitable for the decontamination of biological warfare agents or both chemical and biological warfare agents The compositions comprise generally a blend of biocides, and may additionally comprise a protein and an enzyme. Further, the composition is contained in a buffered foam forming material for ease in distribution The compositions are nontoxic, noncorrosive and nonflammable.

Abstract: The systems and methods of the invention utilize time-resolved techniques to deconvolve a measured response to characterize the nature of particles. The measured response is deconvolved into a scatter component and a fluorescence component. The fluorescence component is further characterized into biological and non-biological components. A discriminant vector is mapped to characterize the nature of the particle.

Abstract: A pressure vessel for containing a mechanical device operable to convert heat to mechanical or electrical power, comprising: a high temperature section, the high temperature section having a first end and an open second end, a sealing flange, the sealing flange having a first end and a second threaded end, the first end bonded to the open second end of the high temperature section, and a low temperature section having an open threaded first end, the open first end in sealing engagement with the second threaded end of the sealing flange. Also provided are a Stirling engine and a method of hermetically sealing a pressure vessel of a Stirling engine.