Abstract: In an example, a conductive concrete structure disclosed. The conductive concrete can include a plurality of conductive side structures defining an interior of the conductive concrete structure and a plurality of conductive concrete partitions disposed within the interior of the conductive concrete structure. The plurality of conductive concrete partitions are arranged to define a labyrinth within the conductive concrete structure.

Abstract: In some implementations, a conductive concrete composition for providing improved shielding against electromagnetic radiation comprises cement, one or more supplementary materials, aggregates, one or more carbon products, and fibers. In some implementations, the composition comprises between about 5% and about 40% by weight of cement, between about 1% and about 20% by weight of one or more supplementary materials, between about 5% and about 80% by weight of aggregates, between about 1% and about 40% by weight of one or more carbon products, and between about 1% and about 10% by weight of fibers. In some embodiments, the one or more supplementary materials comprises ground granulated blast furnace slag (GGBS), the one or more carbon products comprises graphite, and the fibers comprise steel fibers. The aggregates can include normal weight, lightweight, and/or fine aggregates.

Abstract: A conductive concrete electric thermal battery includes conductive concrete; and a plurality of electrodes disposed in the conductive concrete, each electrode of the plurality of electrodes is mechanically isolated from every other electrode of the plurality of electrodes and configured to connect electrically to a source of electrical energy. The conductive concrete includes a mixture of concrete and at least one conductive material.

Abstract: In an example, a conductive concrete structure disclosed. The conductive concrete can include a plurality of conductive side structures defining an interior of the conductive concrete structure and a plurality of conductive concrete partitions disposed within the interior of the conductive concrete structure. The plurality of conductive concrete partitions are arranged to define a labyrinth within the conductive concrete structure.

Abstract: Systems and methods for providing a high performance current source are described. In an example implementation, the current source includes transistors in dual current mirror configuration. The dual mirror configuration employs current feedback to increase the output resistance of the current source while achieving a wide voltage swing.

Abstract: An electrical filter is disclosed. The electrical filter can include a conductive concrete structure including at least one of a conductive carbon material, a magnetic material, or a conductive metallic material. The conductive concrete structure is characterized by an electrical conductivity greater than 0.5 siemens per meter. The electrical filter also includes at least one electrical cable disposed within the conductive concrete structure. The at least one electrical cable includes an input to receive an electrical signal and an output to output an attenuated electrical signal.

Abstract: Systems and methods for a conductive concrete slab having protection against one or more of surface current, ground fault current, and current leakage. A method includes, but is not limited to, introducing an electrical insulation base layer to a ground surface; introducing a plurality of electrodes to the electrical insulation base layer; and casting conductive concrete over the plurality of electrodes and the electrical insulation base layer. An electrical insulation top layer can also be applied to mitigate one or more of surface current and ground fault current.

Abstract: Systems and methods are described for providing a conductive concrete slab having protection against one or more of surface current, ground fault current, and current leakage. A method includes, but is not limited to, introducing an electrical insulation base layer to a ground surface; introducing a plurality of electrodes to the electrical insulation base layer; and casting conductive concrete over the plurality of electrodes and the electrical insulation base layer. An electrical insulation top layer can also be applied to mitigate one or more of surface current and ground fault current.

Abstract: Systems and methods for providing a high performance current source are described. In an example implementation, the current source includes transistors in dual current mirror configuration. The dual mirror configuration employs current feedback to increase the output resistance of the current source while achieving a wide voltage swing.

Abstract: Conductive concrete mixtures are described that are configured to reflect, for instance, EM waves propagating from an EM pulser onto the conductive concrete mixture forming a ground plane, rather than absorb or dissipate the electromagnetic energy. The conductive concrete mixtures include cement, aggregate, water, metallic conductive material, and conductive carbon particles.

Abstract: Conductive concrete mixtures for shotcrete applications are described that are configured to provide varied EM shielding and reflect and/or absorb, for instance, EM waves propagating through the conductive concrete mixture, while providing flowability (e.g., fluidity) for shotcrete applications. The conductive concrete mixtures include cement, aggregate, water, metallic conductive material, and conductive carbon particles and magnetic material. The metallic conductive material may include steel fibers and/or shavings having sizes suitable for application through shotcrete nozzles/applicators, and the magnetic material may include a taconite aggregate, such as taconite sand.

Abstract: An optical fiber (OF) spatial mode filter element includes a structure having an internal cylindrical volume and is adapted to connect an exit end of a first OF with an entrance end of a second OF. An index of refraction of the structure is greater than an index of refraction of a material within the internal cylindrical volume, and when disposed between the exit end of the first OF with the entrance end of the second OF a gap width of the hollow volume between the exit end of the first OF and the entrance end of the second OF defines an effective numerical aperture of the entrance end of the second OF.

Abstract: Conductive concrete mixtures are described that are configured to provide EMP shielding and reflect and/or absorb, for instance, EM waves propagating through the conductive concrete mixture. The conductive concrete mixtures include cement, water, conductive carbon material, magnetic material, and metallic conductive material. The conductive carbon material may include conductive carbon particles, conductive carbon powder, and/or coke breeze. The metallic conductive material may include steel fibers, and the magnetic material may include taconite. The conductive concrete mixture may also include supplementary cementitious materials (SCM). A method of making a concrete structure includes pouring a concrete mixture to form conductive concrete, and positioning a first conductive screen within the conductive concrete proximate to an exterior surface of the conductive concrete.

Abstract: Conductive concrete mixtures are described that are configured to provide EMP shielding and reflect and/or absorb, for instance, EM waves propagating through the conductive concrete mixture. The conductive concrete mixtures include cement, water, conductive carbon material, magnetic material, and metallic conductive material. The conductive carbon material may include conductive carbon particles, conductive carbon powder, and/or coke breeze. The metallic conductive material may include steel fibers, and the magnetic material may include taconite. The conductive concrete mixture may also include supplementary cementitious materials (SCM). A method of making a concrete structure includes pouring a concrete mixture to form conductive concrete, and positioning a first conductive screen within the conductive concrete proximate to an exterior surface of the conductive concrete.

Abstract: Conductive concrete mixtures are described that are configured to provide EMP shielding and reflect and/or absorb, for instance, EM waves propagating through the conductive concrete mixture. The conductive concrete mixtures include cement, aggregate, water, metallic conductive material, and conductive carbon particles and/or magnetic material. The conductive material may include steel fibers, and the magnetic material may include taconite aggregate. The conductive concrete mixture may also include graphite powder, silica fume, and/or other supplementary cementitious materials (SCM). The conductive carbon particles may comprise from about zero to twenty-five percent (0-25%) of the conductive concrete mixture by weight and/or the magnetic material may comprise from about zero to fifty percent (0-50%) of the conductive concrete mixture by weight.

Abstract: Conductive concrete mixtures are described that are configured to provide EMP shielding and reflect and/or absorb, for instance, EM waves propagating through the conductive concrete mixture. The conductive concrete mixtures include cement, aggregate, water, metallic conductive material, and conductive carbon particles and/or magnetic material. The conductive material may include steel fibers, and the magnetic material may include taconite aggregate. The conductive concrete mixture may also include graphite powder, silica fume, and/or other supplementary cementitious materials (SCM). The conductive carbon particles may comprise from about zero to twenty-five percent (0-25%) of the conductive concrete mixture by weight and/or the magnetic material may comprise from about zero to fifty percent (0-50%) of the conductive concrete mixture by weight.

Abstract: A heated bridge deck (20) uses electrodes (24, 26) embedded within conductive concrete and connected to a power source to remove snow and ice accumulation. A cement-based mixture containing optimal amounts of conductive materials is molded into pre-formed slabs (22) placed atop the paved surface of a bridge deck. Alternatively, the conductive concrete may be cast in place on top of an existing bridge deck. A control unit with temperature and moisture sensors may be coupled to the heated bridge deck.

Abstract: Disclosed is a method of “self-encoding” data symbols for transmission over spread-spectrum, (eg. (CDMA), (FDMA)), communication systems which utilizes encountered data symbols, in a sequence of data symbols, to develop data symbol energy spreading codes which are applied to encode subsequently encountered data symbols. The method includes decoding each encoded data symbol after it is transmitted to a receiver in the spread-spectrum communication system.

Abstract: Aspects for preventing deadlock in a log structured array are described. In an exemplary method aspect, and system for providing same, the method includes monitoring available segments to determine when to reserve an open segment, identifying a process type requesting access to the open segment, and limiting access to one process type for the reserved segment. Limiting access further includes limiting access to a garbage collection process.

Abstract: An optical encoding and decoding system which performs code-division multiple access (CDMA) communication in the incoherent, or direct detection, optical domain using bipolar +1/-1 codes. The present invention uses code modulation and detection principles that permit all-optical implementation of the bipolar, +1/-1, code and correlation detection that have been developed for the radio frequency (RF) systems. This is possible in spite of the non-negative, or unipolar, +1/0, nature of the incoherent optical system that only detects and processes the signal intensity. The unipolar optical system of the present invention is equivalent to the bipolar RF system in that the correlation properties of the bipolar codes is completely preserved. The optical CDMA system can be realized both in time or frequency domain encoding with all-optical components.