Abstract: Copoly(imide oxetane) materials are disclosed that can exhibit a low surface energy while possessing the mechanical, thermal, chemical and optical properties associated with polyimides. The copoly(imide oxetane)s are prepared using a minor amount of fluorinated oxetane-derived oligomer with sufficient fluorine-containing segments of the copoly(imide oxetane)s migrate to the exterior surface of the polymeric material to yield low surface energies. Thus the coatings and articles of manufacture made with the copoly(imide oxetane)s of this invention are characterized as having an anisotropic fluorine composition. The low surface energies can be achieved with very low content of fluorinated oxetane-derived oligomer. The copolymers of this invention can enhance the viability of polyimides for many applications and may be acceptable where homopolyimide materials have been unacceptable.

Abstract: Systems, methods, and devices are provided for the creation of predictable and accurate defects in a fiber tow of an Automated Fiber Placement (AFP) process, with such artificial defects being useful to support calibration of an in situ inspection system used in the AFP process. Various embodiments include methods for creating such artificial defects that support calibration of an in situ inspection system of an AFP system or process. Various embodiments may also include a defect stencils for an AFP system or process.

Abstract: A method of detecting defects in a composite structure includes applying heat to a surface of a composite structure. Thermographic images or frames captured by a moving camera may be utilized to corm temporally aligned images that include temperature data (pixels) from a plurality of frames, wherein the pixels comprise data captured at a simple (uniform) time delay from the time at which heat was applied. The temporally aligned thermographic data for the surface region may include variations due to differences in thermal transients caused by defects in the composite structure. The variations in the thermographic data may be utilized to detect one or more defects in the composite structure.

Abstract: An inflatable pressure structure includes an airtight flexible membrane having collapsed and inflated configurations. The inflatable pressure structure includes an elongated pressure-assisted seal that is configured to selectively seal an opening in the airtight flexible membrane. The pressure-assisted seal includes first and second seal components that sealingly engage one another and prevent escape of gas from inside the airtight flexible membrane. The airtight flexible membrane, when inflated, generates a force transverse to the pressure-assisted seal tending to pull the first and second seal components apart. Pressurized gas inside the airtight flexible membrane causes the first and second seal components to more securely engage one another whereby a force transverse to the pressure-assisted seal does not disengage the first and second seal components.

Abstract: A radiation hardened, digital to analog converter includes first and second serial communication circuits, a common bus interface configured to connect the first and second serial communication circuits to first and second digital serial communication buses, respectively, and a digital to analog converter circuit, where the first and second serial communication circuits are configured to receive data over the first and second digital serial communication buses, respectively, for use by the digital to analog converter circuit.

Abstract: A method and system delay the laminar-to-turbulent transition of a supersonic or hypersonic boundary layer flow moving in a flow direction over a surface. For supersonic boundary layer flow, oblique first-mode instability waves present in the boundary layer and propagating at an oblique angle relative to the flow direction cause a laminar-to-turbulent transition in the boundary layer flow. These instability waves have a wavelength associated therewith in a direction perpendicular to the flow direction. Flow disruptors are used to generate modulations within the boundary layer flow wherein a wavelength of the modulations along the direction perpendicular to the flow direction is less than one-half of the wavelength of the instability waves.

Abstract: A lidar system includes an optical transmitter having a laser light source that is configured to generate a beam of light that is azimuthally polarized or has Orbital Angular Momentum (OAM). The lidar system further includes an optical receiver having an optical sensor defining a focal plane. A photon sieve is configured to produce a ring pattern on the focal plane corresponding to a laser return signal. The ring pattern comprises azimuthally polarized or Orbital Angular Momentum (OAM) light that is transmitted by the transmitter and reflected towards the receiver. The photon sieve is also configured to cause stray light that is not polarized to produce a central region at the center of the ring pattern that is distinct from the ring pattern.

Abstract: A method of producing a modification of pigments using atomic layer deposition (ALD) in varying electrical resistivity. More specifically, ALD may be used to encapsulate pigment particles with controlled thicknesses of a conductive layer, such as indium tin oxide (ITO). ALD may allow films to be theoretically grown one atom at a time, providing angstrom-level thickness control.

Abstract: A multi-layer radiation reflector/emitter includes first and second materials. The first material is transparent to radiation in a wavelength spectrum ranging from approximately 0.2 microns to at last 6 microns. The first material is a self-supporting arrangement of randomized particles having an average dimension in a range of approximately 0.2 microns to approximately 0.4 microns and defining a fill factor of approximately 0.1 to approximately 0.5. The second material reflects radiation having a wavelength greater than approximately 2 microns.

Abstract: Provided is a system and method for active multispectral imaging having a transmitter that uses narrowband optical radiation to dynamically illuminate an object with modulated structured light in multiple spectral bands, and a receiver that includes an independent panchromatic imager. The transmitter and receiver can be operated in a bistatic decoupled configuration to enable passive multispectral synthesis, illumination-invariant sensing, optical communications, and the ability for the transmitter to emit a sequence of spectral bands in an order that is unknown to the receiver, and the receiver is able to passively decode the spectral identity from a band identifier embedded in the modulated structured light. The receiver passively decodes embedded high-bandwidth simplex communications while reconstructing calibrated multispectral images at video frame rates.

Abstract: An infrasonic stethoscope for monitoring physiological processes of a patient includes a microphone capable of detecting acoustic signals in the audible frequency bandwidth and in the infrasonic bandwidth (0.03 to 1000 Hertz), a body coupler attached to the body at a first opening in the microphone, a flexible tube attached to the body at a second opening in the microphone, and an earpiece attached to the flexible tube. The body coupler is capable of engagement with a patient to transmit sounds from the person, to the microphone and then to the earpiece.

Abstract: The invention is a magneto-optic coupled magnetic sensor that comprises a standard optical fiber Bragg grating system. The system includes an optical fiber with at least one Bragg grating therein. The optical fiber has at least an inner core and a cladding that surrounds the inner core. The optical fiber is part of an optical system that includes an interrogation device that provides a light wave through the optical fiber and a system to determine the change in the index of refraction of the optical fiber. The cladding of the optical fiber comprises at least a portion of which is made up of ferromagnetic particles so that the ferromagnetic particles are subject to the light wave provided by the interrogation system. When a magnetic field is present, the ferromagnetic particles change the optical properties of the sensor directly.