Detection Of Presence Of Chemical Precursors

sensors
Detection Of Presence Of Chemical Precursors (TOP2-107)
Precursors provide early warning
Overview
Certain selected chemicals associated with terrorist activities are too unstable to be prepared in final form. These chemicals are often prepared as precursor components, to be combined at a time immediately preceding the detonation. One example is a liquid explosive, which usually requires an oxidizer, an energy source, and a chemical or physical mechanism to combine the other components. Detection of the oxidizer (e.g.H2O2) or the energy source (e.g. nitromethane) is often possible, but must be performed in a short time interval l(e.g.,5- 15seconds) and in an environment with a very small concentration (e.g.1-100ppm), because the target chemical(s) is carried in a sealed container.

The Technology
These needs are met by this invention, which provide easy stem and associated method for detecting one or more chemical precursors (components) of a multi-component explosive compound. Different carbon nanotubes (CNTs) are loaded (by doping, impregnation, coating, or other functionalization process) for detecting of different chemical substances that are the chemical precursors, respectively, if these precursors are present in a gas to which the CNTs are exposed. After exposure to the gas, a measured electrical parameter (e.g. voltage or current that correlate to impedance, conductivity, capacitance, inductance, etc.) changes with time and concentration in a predictable manner if a selected chemical precursor is present, and will approach an asymptotic value promptly after exposure to the precursor. The measured voltage or current are compared with one or more sequence soft heir reference values for one or more known target precursor molecules, and a most probable concentration value is estimated for each one, two, or more target molecules. An error value is computed, based on differences of voltage or current for the measured and reference values, using the most probable concentration values. Where the error value is less than a threshold, the system concludes that the target molecule is likely. Presence of one, two, or more target molecules in the gas can be sensed from a single set of measurements.
Gas Refinery Pipes The technology provide easy stem and associated method for detecting one or more chemical precursors (components) of a multi-component compound.
Benefits
  • High sensitivity sensors (ppm-ppb)
  • Real-time response
  • Distinction between multiple-target molecules that may be present
  • Energy efficient
  • Detects at least one oxidizer and at least one energizer
  • One or more target molecules in the gas can be sensed from a single set of measurements

Applications
  • Homeland Security and Defense
  • Airports
  • Chemical processing environments
  • Gas Leak detection
  • Environmental monitoring
Technology Details

sensors
TOP2-107
ARC-15566-5
7,623,972
Similar Results
Enviornment
Completely biodegradable filtration system for waste metal recovery from aqueous solution
There is a significant need for an inexpensive biological approach to recover specific, targeted metals and other target materials in e-waste or other aqueous solutions that requires minimal input of resources, including energy. This invention is a method of removing or adsorbing a target substance or material, for example, a metal, non-metal toxin, dye, or small molecule drug, from solution, by functionalizing a substrate with a peptide configured to selectively bind to the target substance or material and to bind to the substrate. The substrate is fungal mycelium, and the naturally-occurring or bioengineered peptide is called a target-binding domain, which is chemically bonded to a selected solid substrate. The target chemical species binds to the target-binding domain and is removed from solution. The target can be any chemical species dissolved or suspended in the solution. Capture of the target by the substrate can isolate and allow removal of the target substance from solution, or for utilization in water filtration, or recovery of targeted chemical species from solution, particularly aqueous solution applications. The peptides used include (i) fusion peptides and/or proteins containing metal-binding domain sequence and optionally containing substrate-binding domain sequence; (ii) fusion peptides/proteins containing a metal-binding domain and a chitin-binding domain; and (iii) nucleic acids encoding fusion peptides and/or proteins containing metal-binding domain sequence. The technology enables simple scale up to a level that could be successfully implemented in an environment with limited resources, such as on a space mission or on earth in developing countries with poor access to clean water.
Visualization of LIDAR instrument aboard the CALIPSO satellite
Photo-Acoustic Sub Part-Per-Billion Chemical Sensing
The technology is a sensor for remotely detecting sub part-per-billion (ppb) levels of ambient trace gases and chemical species. The system includes a high-repetition-rate, pulsed laser module that is spectrally tuned to a desired chemical species. The photons from the laser are absorbed by the target chemical, creating an acoustic vibration that impacts a diaphragm (which acts like a speaker). A highly sensitive, photo-emf detector is then used to measure the magnitude of the vibration, which corresponds to the concentration of the target chemical. The technology is being developed for NASA's trace-gas measurement needs for validation and ground truth studies to support airborne and space-based LIDAR operations. The technology has application as a chemical sniffer to detect hazardous or toxic chemical species in the vicinity of IEDs, explosives, or other chemical agents. In such an application the sensor could detect chemical species hidden inside closed containers, bags, or car trunks.
Biohazard Warning
Solid And Liquid Waste Drying Bag
This invention addresses the problem of human solid waste disposal in microgravity, and consists of a soft-sided container or bag that (1) collects wet material using airflow, (2) compacts material under vacuum, and (3) dries material under applied vacuum. End products are clean water and dried, compacted, and bagged material. The bag includes a liquid-impermeable and vapor-impermeable outer layer and a liquid-impermeable but vapor-permeable inner layer membrane, defining an inner bag, through which some vapor can pass. The port is located in the outer layer, and activation of the vacuum source causes some of the original vapors and vaporized liquids to pass through the membrane liner. Liquid components of the moist waste solids within the bag may also be vaporized and transported across the membrane. Waste solids, such as excrement, remain in an inner layer defined by the membrane, and are partly dried by withdrawal of vaporized liquid and vaporized liquid components in the moist solids. These waste solids are thereby trapped and sealable in the bag, while the original vapors and the vaporized portion of the liquids pass through the membrane and are received by an outer bag defined by the membrane and the outer layer of the bag. After use, the bag is sealed and stored for ultimate disposal.
Green PCB chip
Hybrid carbon nanotube-gold nanoparticle composite for Nitric Oxide (NO) detection
A hybrid thin film is fabricated by a simple drop-casting method. Functionalized single-walled carbon nanotubes (SWCNTs) and gold nanoparticles (AuNPs) with a diameter of ≈15 nm are drop-casted onto a printed circuit board (PCB) substrate equipped with interdigitated electrodes. The addition of AuNPs to the carbon nanotube networked films enhance sensitivity and lower the detection limit to low parts-per-billion (ppb) concentrations. The gold particle to carbon nanotube ratio is optimized to find the optimum gold nanoparticle loading. The composite films were tested in both air and nitrogen environments across a wide relative humidity range (0-97%), which is suitable for dissolved Nitric Oxide (NO) detection in sea water for oceanographic study and for human breath analysis in medical diagnosis. The sensors exhibited high selectivity, particularly to NO, outperforming other tested gases. Notably, the sensor reliably detected NO at 10 ppb levels with response times within 10 seconds and recovery time around 1 minute, showcasing excellent reproducibility across sensors and operational efficiency within diverse humidity conditions.
High Flow Differential Cleaning
NASA developed this High Flow Differential Cleaning technology in response to in-house needs for a more automated and effective method to remove stubborn particles from complex parts fabricated using powder-bed-fusion equipment. The invention uses a large volume of pressurized air to quickly enter a cleaning chamber. Based on the Bernoulli principle and Continuity equation, the high flow results in significant air velocity and a decrease in pressure when airflow passes through smaller component orifices, which in turn removes remnant powder from the part. In one embodiment, the invention consists of a (1) high-pressure air compressor with ISO 8573 Class 2 drying capability, (2) a large pressure chamber with a fast-actuated valve system to, (3) a cleaning chamber containing various sensors, injection systems, (4) a test fixture designed for easy orientation adjustments, and (5) an expansion chamber allowing air to expand and drop in velocity, particles to settle, and filtered air to re-enter the room. This NASA technology can be implemented as a standalone cleaning system for powder bed fusion additively manufactured parts, or could be integrated into a packaged post-processing system offering. CT scans of complex NASA parts cleaned using a proof-of-concept system based upon the invention revealed very promising results. NASA welcomes industry to test the cleaning speed and efficacy of the technology under an evaluation license.
Stay up to date, follow NASA's Technology Transfer Program on:
facebook twitter linkedin youtube
Facebook Logo Twitter Logo Linkedin Logo Youtube Logo