Abstract: In one general aspect, a sample area is energized. A thermal energy status of the sample area is monitored. The thermal energy status including at least one of a radiant energy and a temperature. A thermal signature of a region included in the sample area is determined based on the thermal energy status of the region. The thermal signature is analyzed to determine whether explosive particles are included in the region.

Abstract: In one aspect, an apparatus includes a head configured to receive a pad for sampling explosive residue on a surface and a feedback system coupled to the head. The feedback system is configured to indicate when a pressure applied by the head is greater than a minimum threshold value. In another aspect, an apparatus includes a head configured to receive a pad and rotate to apply a shear force to the pad for sampling explosive residue on a surface. The apparatus includes a feedback system coupled to the head, which is configured to restrict the shear force applied by the head to be within a predetermined range. In another aspect, a method includes applying pressure to a pad to sample explosive residue on a surface, sensing the pressure applied to the pad, and providing an indication of when the pressure applied to the pad is greater than a threshold value.

Abstract: Screening an item for prohibited material may include multiple pressurization and rapid depressurization cycles. Screening an item for prohibiting material may include a pressurization chamber including one or more items to be screened for prohibited material and one or more filler objects.

Abstract: A particle-harvesting material includes a flexible, reusable, and thermally conductive material including a rough surface having dimples of a size within a first range of sizes, a microstructure including interstices of a second range of sizes, the second range of sizes including sizes smaller than the first range of sizes, and an etched portion on the rough surface configured to attract particles upon contact between the particles and the etched portion.

Abstract: In one aspect, an apparatus includes a head configured to receive a pad for sampling explosive residue on a surface and a feedback system coupled to the head. The feedback system is configured to indicate when a pressure applied by the head is greater than a minimum threshold value. In another aspect, an apparatus includes a head configured to receive a pad and rotate to apply a shear force to the pad for sampling explosive residue on a surface. The apparatus includes a feedback system coupled to the head, which is configured to restrict the shear force applied by the head to be within a predetermined range. In another aspect, a method includes applying pressure to a pad to sample explosive residue on a surface, sensing the pressure applied to the pad, and providing an indication of when the pressure applied to the pad is greater than a threshold value.

Abstract: Energy released from energized particles is sensed. Whether the energized particles include a possible energetic material is determined based on the sensed energy. If a determination is made that the energized materials include a possible energetic material, a spectral signature of the sensed energy is determined. The spectral signature of the sensed energy is compared to one or more known spectral signatures associated with energetic materials. Whether the possible energetic material is an actual energetic material is determined based on the comparison.

Abstract: Techniques for detecting contraband are described, as are techniques for generating an image of living tissue. A location of interest relative to a target space is received, and a radar signal is transmitted in the direction of the location of interest. Portions of the radar signal are detected with multiple receiving structures. The detected portions are processed to generate information corresponding to dielectric or loss properties, the properties corresponding to particular positions within the target space. A determination is made as to whether contraband is present in the target space based on the determined properties.

Abstract: A handheld radar frequency scanner system for detecting objects concealed on a person, the system includes a radar transmitter coupled to a transmit antenna that is configured and positioned to direct a radar signal at a person, a radar receiver coupled to a receive antenna that is configured to detect a portion of the radar signal reflected by the person, and a processor connected to the radar receiver and operable to process the portions of the radar signals detected by the radar receiver to determine whether the person is carrying a concealed object. The system may produce a real-time alert, such as an audible alert, when a concealed object is detected.

Abstract: A position of an object moving through a region of interest is determined, and at least one source of an air stream is selectively activated based on the determined position. The air stream is capable of dislodging a particle from the object moving through the region of interest. The air stream is directed toward the region of interest. An air collector is selectively activated, based on the determined position, to draw air from the region of interest. The drawn air is deposited on a sample collector, and the sample collector is analyzed to determine whether the deposition of the air stream left particles of a material of interest on the sample collector.

Abstract: A particle-harvesting material includes a flexible, reusable, and thermally conductive material including a rough surface having dimples of a size within a first range of sizes, a microstructure including interstices of a second range of sizes, the second range of sizes including sizes smaller than the first range of sizes, and an etched portion on the rough surface configured to attract particles upon contact between the particles and the etched portion.

Abstract: Techniques for detecting contraband are described, as are techniques for generating an image of living tissue. A location of interest relative to a target space is received, and a radar signal is transmitted in the direction of the location of interest. Portions of the radar signal are detected with multiple receiving structures. The detected portions are processed to generate information corresponding to dielectric or loss properties, the properties corresponding to particular positions within the target space. A determination is made as to whether contraband is present in the target space based on the determined properties.

Abstract: A composition comprising a carrier liquid; a dispersant; and a chemical hydride. The composition can be used in a hydrogen generator to generate hydrogen for use, e.g., as a fuel. A regenerator recovers elemental metal from byproducts of the hydrogen generation process.

Abstract: A composition comprising a carrier liquid; a dispersant; and a chemical hydride. The composition can be used in a hydrogen generator to generate hydrogen for use, e.g., as a fuel. A regenerator recovers elemental metal from byproducts of the hydrogen generation process.