Tech Briefs

Personal Annunciation Device (PAD)

The PAD can be used where chemical, biological, or other hazards are present, and traditional notification means are not adequate.

Many industrial and commercial plants, government and private research facilities, and industrial facilities perform potentially dangerous processes. Automated warning and alarm systems alert personnel to dangerous or abnormal conditions inside or near a plant so the personnel may take prompt protective action such as evacuation, co-location, or shelter in place. Such automated systems include simple fire and smoke detectors that detect the presence of fire or smoke and immediately activate a connected, audible alarm confined to a specific area of a plant. Many systems include a central hub for receiving detection signals from detectors located throughout a plant. In some systems, the central hub also is connected to a network of alarms including audible alarms — both siren-like and information-based — and visual alarms, including flashing emergency lights and textual-based information screens.

Posted in: Briefs, Communications, Security systems, Wireless communication systems, Security systems, Wireless communication systems, Smoke detection, Smoke detection, Automation, Evacuation and escape, Fire detection

Decoupled Ranging and Orientation Inversions Enable Linear and Fast Long-Range Non-Line-of-Sight Positioning

New linear solutions are significantly simpler than the previous complex nonlinear solutions.

The wireless radio positioning or radiolocation problem is of great importance in society today. Existing radiolocation systems such as the Global Positioning System (GPS), Radio-Frequency Identification (RFID) systems, and Ultra Wide-Band (UWB) systems use propagating EM waves and show reduced accuracy in non-line-of-sight (NLoS) environments due to propagation losses, delays, or multi-path effects. These significantly limit their use in radiolocation applications where the line of sight to the device is blocked. Examples of these are many, and include radiolocation for a device inside a cave or building, embedded underground or in a tunnel or mine, and for underwater applications, which covers a multitude of space, military, and civilian applications. In addition to these severe limitations, existing radiolocation systems using propagating EM waves enable ranging and positioning, but cannot provide precision two-dimensional (2D) or three-dimensional (3D) orientation sensing, which is critical in many applications where the sensor's attitude is important.

Posted in: Briefs, Test & Measurement, Global positioning systems, Global positioning systems (GPS), Radio equipment, Sensors and actuators, Global positioning systems, Global positioning systems (GPS), Radio equipment, Sensors and actuators

Calibration and Synchronization of Micro-Air-Vehicle Autopilots

Conventional calibration of an inertial measurement unit (IMU) through open-loop data collection includes typical flight simulator systems that provide processed stimuli to emulate real-life flight conditions. Other solutions involve testing inertial measurement devices on a multi-axis rate table using a processor internal to the inertial measurement devices, and transferring the signals directly to the processors for determining and storing the calibration coefficients of the inertial measurement devices internally so that they are self-calibrating. Unfortunately, conventional solutions typically involve evaluating control algorithms in a computer simulation before experimentation in the aircraft occurs. This can result in unstable flight during the first few cycles that could lead to failure of the aircraft.

Posted in: Briefs, Aeronautics, Aerospace, Calibration, Computer simulation, Automatic pilots, Automatic pilots, Test procedures, Aircraft

Ultrasonic Transducer Delivery Tool

This tool can be used in any industry using double-walled storage tanks.

Stennis Space Center has the need to measure the inner wall thickness of cryogenic storage tanks without entering the inner tank of the double-walled vessels. It was proposed that an ultrasonic probe be inserted through access points in the outer wall of the vessel and delivered to the inner wall of the vessel, which would provide for at least a discrete set of inner wall thickness measurements where access points were available.

Posted in: Briefs, Test & Measurement, Measurements, Tools and equipment, Storage, Inspections

Graphene-Based Sensor for Improved Evaluation, Diagnosis, and Treatment of Asthma

This device detects and measures inflammation in the lungs.

Asthma, which causes inflammation of the airway and obstructs airflow, affects about 300 million people worldwide. Symptoms include coughing, wheezing, shortness of breath, and chest tightness. Other serious lung ailments include chronic obstructive pulmonary disease (COPD), which encompasses emphysema and chronic bronchitis.

Posted in: Briefs, Medical, Sensors and actuators, Sensors and actuators, Diagnosis, Diseases, Fluids and secretions, Medical equipment and supplies, Nanotechnology

Mobile Underwater Acoustic Communications

This invention does not require any complicated signal processing.

Reliable, long-range acoustic communications (LRAC) is an enabling technology for numerous applications of manned and unmanned underwater systems. For example, with the capability of communicating at long ranges of several hundreds or even thousands of kilometers, it will become possible to remotely command and control unmanned underwater vehicles that are otherwise unreachable. As another example, underwater systems will be able to rely on such capability to establish a wide-area undersea network to complete missions in a collaborative fashion.

Posted in: Briefs, Communications, Telecommunications systems, Telecommunications systems, Acoustics, Acoustics, Marine vehicles and equipment

Three-Dimensional Zinc Electrode Architectures for High-Performance Batteries

Zinc-based batteries offer a safe, inexpensive alternative to fire-prone lithium-based batteries, yet have been historically limited by poor rechargeability. A 3D zinc (Zn) “sponge” electrode architecture was developed comprising interpenetrating networks of Zn scaffolding and void space. The design characteristics yield superior electrochemical properties when cycled in alkaline electrolytes compared to conventional Zn powder-composite electrodes.

Posted in: Briefs, Energy, Architecture, Batteries, Battery cell chemistry, Architecture, Batteries, Battery cell chemistry, Zinc alloys

Nanofabricated Devices Detect Ultrasound with Light

Tiny, soft, transparent, nanofabricated devices can be integrated into a contact lens.

The Micro-ring resonator detector can determine the speed of blood flow and the oxygen metabolic rate at the back of the eye. This information could help diagnose such common and debilitating diseases as macular degeneration and diabetes. The tiny, transparent device can fit into a contact lens, and could help a range of scientific endeavors from biomedicine to geology.

Posted in: Briefs, Test & Measurement, Optics, Sensors and actuators, Optics, Sensors and actuators, Diagnosis, Medical equipment and supplies, Fabrication, Nanotechnology

A Smooth-Walled Feedhorn with Sub-30-dB Cross-Polarization Over a 30-Percent Bandwidth

The focus of this research was the design, optimization, and measurement of a monotonically profiled, smooth-walled scalar feedhorn with a diffraction-limited ~14° FWHM (full width at half maximum). It is an easier-to-manufacture, smooth-walled feed that approximates the properties of excellent beam symmetry, main beam efficiency, and cross-polar response over wide band-widths, but over a finite bandwidth.

Posted in: Briefs, Communications, Optimization, Antennas, Radio equipment, Antennas, Radio equipment, Research and development

System for Repairing Cracks in Structures

This thermally activated coating heals cracks in metallic materials.

NASA’s Langley Research Center has developed an innovative coating to heal cracks in metal components, such as in aircraft and bridges. Currently, the coating is used for in-laboratory repairs of surface cracks. Development continues with the ultimate goal of an in-situ healing mechanism that can work autonomously with structural health monitoring detectors.

Posted in: Briefs, Coatings & Adhesives, Materials, Aircraft structures, Sensors and actuators, Sensors and actuators, Thermodynamics, Thermodynamics, Maintenance, Repair and Service Operations, Maintenance, repair, and service operations, Coatings Colorants and Finishes, Coatings, colorants, and finishes, Fatigue

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