Abstract: A structural member includes a split beam within a box structure. The split beam may be a segmented beam that includes multiple segments for each of its parts. Movement of the split beam parts within the box structure, as the structural member flexes, dissipates energy and adds to the damping of the structural member.

Abstract: A shape-changing structural member has a shape-changing material, such as a suitable foam material, for example a polymer foam capable of withstanding at least 300% strain or a metal alloy foam capable of withstanding at least 5% strain. Springs, such as one or more coil springs, provide structural support for the shape-changing material. The springs may also be used to provide forces to expand and contract the shape change material. The springs may include pairs of concentric springs, one inside of another. The concentric springs may surround an underlying skeleton structure that supports the shape-changing material and/or aids in changing the shape of the material. The concentric springs may or may not be wrapped around the underlying skeleton structure. Multiple springs or pairs of springs may be coupled together using a sheet metal connector.

Abstract: A shape-changing structural member has a shape-changing material, such as a suitable foam material, for example a polymer foam capable of withstanding at least 300% strain or a metal alloy foam capable of withstanding at least 5% strain. Springs, such as one or more coil springs, provide structural support for the shape-changing material. The springs may also be used to provide forces to expand and contract the shape change material. The springs may include pairs of concentric springs, one inside of another. The concentric springs may surround an underlying skeleton structure that supports the shape-changing material and/or aids in changing the shape of the material. The concentric springs may or may not be wrapped around the underlying skeleton structure. Multiple springs or pairs of springs may be coupled together using a sheet metal connector.

Abstract: An active infrared sensor may include an imaging infrared sensor to provide an output signal conveying time-sequential infrared images of a scene which includes a subject, a beam generator to generate a millimeter wave energy beam, and a processor. An initial infrared image of the scene may be stored in a memory. After storing the initial infrared image, the beam generator may illuminate the subject with the millimeter wave energy beam. A temperature change across the subject due to the millimeter wave energy beam may be estimated based on the output signal and the stored initial infrared image. The beam generator may stop illuminating the subject when a highest temperature change across the subject is at least equal to a predetermined temperature change limit.

Abstract: A shape-changing structure has a superelastic metal foam structural member that changes shape (morphs) to change configuration of the structure. The superelastic metal foam structural member changes shape while maintaining a continuous outer surface, with the continuous metal foam material inside the outer surface expanding, contracting, or otherwise changing shape. The superelastic metal foam material may be heated above a transition temperature to allow it to change shape, and then cooled to cause it to increase in strength, more easily maintaining its new shape. The superelastic metal foam material may be a suitable alloy, for example a nickel titanium alloy, that exhibits superelastic (pseudoelastic) behavior. The superelastic metal foam material may be a shape memory alloy material that returns to a set shape upon moderate heating. The superelastic metal elastic foam structural member may be heated either by an internal heat source or by external heating.

Abstract: A laminated wing structure includes at least one layer of metal material and at least one layer of a shape memory polymer (SMP) material. The SMP is heated to a temperature in its glass transition band Tg to roll the wing around the air vehicle into a stored position. The metal layer(s) must be thin enough to remain below its yield point when rolled up. In preparation for launch, the SMP material is thermally activated allowing the strain energy stored in the layer of metal material to return the wing to its deployed position at launch. Once deployed, the SMP cools to its glassy state. The SMP material may be reinforced with fiber to form a polymer matrix composite (PMC). SMP may be used to provide shear strain relief for multiple metal layers. By offloading the motive force required to return the wing to its original deployed position from the SMP to the metal, the polymer does not acquire a permanent set and the wing may be deployed accurately.

Abstract: A wing, such as a wing for an unmanned aerial vehicle (UAV), includes a beam or box that can be selectively expanded from a collapsed condition, to increase the thickness of the wing. The beam may include a pair of plates that are close together when the beam is in a collapsed condition, and separate from one another to put the beam in an expanded condition. The plates may be substantially parallel to each other, and may have shape memory foam and/or resilient devices, such as coil springs, between them, in order to provide a force to separate the plates before, during, and/or after deployment of the wing. The expandable/collapsible beam may have a lock mechanism to lock it into place when the beam is in an expanded condition.

Abstract: A shape-changing structure has a superelastic metal foam structural member that changes shape (morphs) to change configuration of the structure. The superelastic metal foam structural member changes shape while maintaining a continuous outer surface, with the continuous metal foam material inside the outer surface expanding, contracting, or otherwise changing shape. The superelastic metal foam material may be heated above a transition temperature to allow it to change shape, and then cooled to cause it to increase in strength, more easily maintaining its new shape. The superelastic metal foam material may be a suitable alloy, for example a nickel titanium alloy, that exhibits superelastic (pseudoelastic) behavior. The superelastic metal foam material may be a shape memory alloy material that returns to a set shape upon moderate heating. The superelastic metal elastic foam structural member may be heated either by an internal heat source or by external heating.

Abstract: A shape-changing structural member has a shape-changing material, such as a suitable foam material, for example a polymer foam capable of withstanding at least 300% strain or a metal alloy foam capable of withstanding at least 5% strain. Springs, such as one or more coil springs, provide structural support for the shape-changing material. The springs may also be used to provide forces to expand and contract the shape change material. The springs may include pairs of concentric springs, one inside of another. The concentric springs may surround an underlying skeleton structure that supports the shape-changing material and/or aids in changing the shape of the material. The concentric springs may or may not be wrapped around the underlying skeleton structure. Multiple springs or pairs of springs may be coupled together using a sheet metal connector.

Abstract: A structure includes a polymer structural member, which may include a shape memory polymer material, that can change its size and/or shape. An electromagnetic source is used to impose an electric field or a magnetic field on the polymer structural material, in order to control the shape of the material. The force may be used to change the shape of the material and/or to maintain the shape of the material while it is under load. The polymer material may be a solid material, may be a foam, and/or may include a gel. A shape memory polymer material may have mixed in it particles that are acted upon by the electromagnetic field. The structure may be used in any of a variety of devices where shape change (morphing), especially under loading, is desired.

Abstract: A system for preventing freezing of crops within a volume includes a plurality of RF radiators configured to radiate RF energy into the volume. A height, a spacing, an output power, a vertical beam angle, a vertical beam width, and a horizontal beam width of each one of the plurality of RF radiators is selected to result in an average RF power density taken about three dimensions within the volume sufficient to prevent freezing of a substantial portion of the crops, and also to result in a peak-to-peak variation of RF power density taken about two dimensions in a horizontal plane within the volume and at heights below a predetermined height to be less than a predetermined percentage of an average RF power density taken about the two dimensions.

Abstract: A method of generating a high-level vacuum comprises evacuating a chamber having a substantially-pure gas therein to a medium-level vacuum, and freezing the residual gas to generate the high-level vacuum within the chamber. Impurities, such as atmospheric air, may be purged from the chamber by evacuating the chamber to a medium level vacuum (e.g., around 10?2 Torr) and subsequently filling the chamber with the gas. This purging process may be repeated multiple times to decrease the level of impurities in the gas filling the chamber. The substantially-pure gas may have an impurity-level of less than approximately 100 PPM and may comprise carbon-dioxide, although the scope of the invention is not limited in this respect. The medium level vacuum may range between approximately 1×10?2 Torr and 5×10?2 Torr allowing the use of a roughing pump, and the high-level vacuum may range between approximately 1×10?5 and 1×10?8 Torr.

Abstract: A system and method for monitoring a cargo container. The novel system (100) includes a sensor module (10) mounted in each target area (20) and a central monitoring system (40). Each sensor module (10) includes one or more sensors (22) and a transceiver (28) for transmitting data from the sensors to the central monitoring system (40). The central monitoring system (40) includes a transceiver (44) for receiving the data from all sensor modules (10) and a local master processor (46) for processing and analyzing the data. In the preferred embodiment, each transceiver (28) is capable of receiving and retransmitting signals of other sensor modules to relay signals of a particular sensor module (10) in a daisy chain fashion to and from the central monitoring system (40).

Abstract: A system and method for monitoring a cargo container. The novel system (100) includes a sensor module (10) mounted in each target area (20) and a central monitoring system (40). Each sensor module (10) includes one or more sensors (22) and a transceiver (28) for transmitting data from the sensors to the central monitoring system (40). The central monitoring system (40) includes a transceiver (44) for receiving the data from all sensor modules (10) and a local master processor (46) for processing and analyzing the data. In the preferred embodiment, each transceiver (28) is capable of receiving and retransmitting signals of other sensor modules to relay signals of a particular sensor module (10) in a daisy chain fashion to and from the central monitoring system (40).

Abstract: A light transmitter/receiver is shielded against high-power radio-frequency radiation by a window having a first light-transparent plate, a second light-transparent plate disposed substantially parallel to and spaced apart from the first light-transparent plate, a frame receiving the first light-transparent plate and the second light-transparent plate therein, and a liquid filling the space between the first light-transparent plate and the second light-transparent plate. The liquid includes water. The window is positioned between the light transmitter/receiver and a source of radio-frequency radiation with the first light-transparent plate facing the source. The radio-frequency radiation has a frequency exceeding about 0.9 GHz and a power exceeding about 1 milliwatt per square centimeter measured at the first light-transparent plate.

Abstract: An explosively-driven magneto-cumulative generator that employs a Bitter coil with configurable electromagnet windings and insulation in its stator. An armature with a conducting metal liner filled with high explosive is initiated by an initiator and a switchable seed capacitor. The stator is coaxially aligned with and surrounds the armature and comprises the Bitter coil. A load is coupled between the armature and the Bitter coil. The Bitter coil comprises a series of conducting annular disks with an azimuthal sector of conductor removed. The disks are stacked with interleaved insulation, and are connected turn-by-turn. The windings of the Bitter coil can be modified, turn-by-turn, to change the inner and outer radii, and thickness, of each winding, and the material, size, and spacing of the interleaving insulation. This design variability solves many performance problems of conventional magneto-cumulative generators.

Abstract: A high-power wideband transformer (40). The transformer (40) includes a first input terminal (42) connected in parallel to one or more conductor paths (50 and 52) and to a first output conductor (48). A second input terminal (44) is connected in parallel to the one or more conductor paths (50 and 52) and to a second output conductor (54). An inductive device (56, 60, 64, 58, 62, and 66) effects electrical coupling between the one or more conductor paths (50 and 52) and the first output conductor (48) and between the one or more conductor paths (50 and 52) and the second output conductor (54) sufficient to implement a desired transformer ratio from input of the transformer (40) to output of the transformer (40) via approximately colinear wires (56, 60, and 64). In a first illustrative embodiment, the co-linear wires (56, 60, and 64) are parallel wires placed sufficiently close to effect the electrical coupling. The transformer 40 effects a nine-to-one transformer ratio.

Abstract: A broadband, high power balun which includes plural sets of first and second coaxial cables. Each cable has a center conductor and a shield conductor. Each shield conductor of each cable within each set is connected to a shield conductor of the other coaxial cable of the set. The first input lead is connected to a first end of a center conductor of a first coaxial cable of each set. The second input lead is connected to a first end of a center conductor of a second coaxial cable of each set. A second end of a center conductor of a first coaxial cable of a set of coaxial cables provides an output lead for the balun. A second end of a center conductor of a second coaxial cable of a set of coaxial cables provides an output lead for the balun. A second end of each remaining center conductor of each coaxial cable of each set of coaxial cables is connected to a second end of a center conductor of a coaxial cable of another set of coaxial cables.

Abstract: A wire antenna having a Vivaldi taper that is used to radiate or receive low frequency RF energy from or to an airborne platform. The antenna comprises two conducting wires that trail from the platform, and which comprise a radiator having a Vivaldi taper. The shape of the conducting wires is maintained by a combination of aerodynamic drag on the conducting wires, a weight connected to the end of the lower wire, a chute connected to the end of the upper wire, and nonconducting guy-wires connecting the upper and lower conducting wires. The nonconducting guy-wires are positioned at locations between the upper and lower conducting wires to form and maintain an optimal taper between the conducting wires. A method of deploying a Vivaldi antenna from an airborne platform is also disclosed. A lower conducting wire is attached to the enclosure, and an upper conducting wire is attached to a chute. The antenna and chute are stored in the enclosure, and the enclosure is disposed beneath the platform.