Search NASA⌕ Search

SEARCH · Search NASA

Results for “hydrazine detection”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4

A study for hypergolic vapor sensor development

The use of an electrochemical technique for MMH and N02 measurement was investigated. Specific MMH and N02 electrochemical sensors were developed. Experimental techniques for preparation, handling, and analysis of hydrazine's vapor mixtures at ppb and ppm levels were developed. Two approaches to N02 instrument design were evaluated including specific adsorption and specific electrochemical reduction. Two approaches to hydrazines monitoring were evaluated including catalytic conversion to N0 with subsequent N0 detection and direct specific electrochemical oxidation. Two engineering prototype MMH/N02 monitors were designed and constructed.

Stetter, J. R.↗

Hydrazine Detectors Based On Raman Scattering

Goal of sensor-development program to measure concentrations as low as few parts per billion in continuous monitoring as well as peak concentrations up to hundreds of parts per million, such as encountered near leaks. Sensors based on Raman scattering from hydrazine or monomethyl hydrazine adsorbed on roughened metal or metal oxide substrates. Similar systems developed to detect nitrogen oxides and other gases.

Rupich, Martin W.↗

Electronic Nose: Evaluation of Kamina Prototype Unit

The Kamina, Sam and Cyranose electronic nose systems were evaluated and partially trained. Much work was performed on the Kamina as it has the ability to respond to low (less than 10 ppb) concentrations of hydrazine compounds. We were able to tell the difference between Hydrazine (Hz) and Monomethylhydrazine (MMH) in standard clean humid air. We were able to detect MMH in reduced pressure (1/3 atm) at about 250 ppb, however the training set was to far from the real situation to be useful now. Various engineering and usability aspects of both the noses was noted, especially the software. One serious physical engineering flaw was remedied in the Kamina system. A gas flow manifold was created for the Sam system. Different chips were evaluated for the Kamina system. It is still unclear if they can be exchanged without retraining the software.The Sam Detect commercial unit was evaluated for solvent detection and evaluation. It was able to successfully identify some solvents. The Cyranose, was observed and evaluated for two days. It has the ability to detect gasses in the 100 parts per million level but not the 10 parts per billion level. It is very sensitive to humidity changes; there is software to partially handle this.

Schattke, Nathan↗

Development of Microfabricated Chemical Gas Sensors and Sensor Arrays for Aerospace Applications

Aerospace applications require the development of chemical sensors with capabilities beyond those of commercially available sensors. In particular, factors such as minimal sensor size, weight, and power consumption are particularly important. Development areas which have potential aerospace applications include launch vehicle leak detection, engine health monitoring, fire detection, and environmental monitoring. Sensor development for these applications is based on progress in three types of technology: 1) Micromachining and microfabrication (Microsystem) technology to fabricate miniaturized sensors. 2) The use of nanocrystalline materials to develop sensors with improved stability combined with higher sensitivity. 3) The development of high temperature semiconductors, especially silicon carbide. However, due to issues of selectivity and cross-sensitivity, individual sensors are limited in the amount of information that they can provide in environments that contain multiple chemical species. Thus, sensor arrays are being developed to address detection needs in such multi-species environments. This paper discusses the needs of space applications as well as the point-contact sensor technology and sensor arrays being developed to address these needs. Sensors to measure hydrogen, hydrocarbons, hydrazine, nitrogen oxides (NO,), carbon monoxide, oxygen, and carbon dioxide are being developed as well as arrays for leak, fire, and emissions detection. Demonstrations of the technology will also be discussed. It is concluded that microfabricated sensor technology has significant potential for use in a range of aerospace applications.

Hunter, G. W.↗

Low level vapor verification of monomethyl hydrazine

The vapor scrubbing system and the coulometric test procedure for the low level vapor verification of monomethyl hydrazine (MMH) are evaluated. Experimental data on precision, efficiency of the scrubbing liquid, instrument response, detection and reliable quantitation limits, stability of the vapor scrubbed solution, and interference were obtained to assess the applicability of the method for the low ppb level detection of the analyte vapor in air. The results indicated that the analyte vapor scrubbing system and the coulometric test procedure can be utilized for the quantitative detection of low ppb level vapor of MMH in air.

Mehta, Narinder↗

Insight the process of hydrazine gas adsorption on layered WS 2 : a first principle study

The process of hydrazine gas adsorption on layered WS 2 has been systematically studied from first principle calculations. Our results demonstrate that this adsorption process is exothermic, and hydrazine molecules are physically adsorbed. The layer-dependent adsorption energy and interlayer separation induced by van der Waals interaction exerted by hydrazine molecules lead to the difficulty in desorbing hydrazine molecules from layered WS 2 as the number of layers increases. The most interesting finding is the emergence of localized impurity states below the Fermi level upon the hydrazine adsorption, irrespective of the number of WS 2 layers, resulting in a significant effect on the band structures and subsequently changing its electrical conductivity. Furthermore, a layer-dependent small charge transfer occurs between hydrazine and layered WS 2 , leading to a charge redistribution and considerable polarization in the adsorbed systems. The existence of defects and the humidity, on the other hand, influences the sensitivity of layered WS 2 to the hydrazine adsorption. Here, obtained results show that a perfectly layered WS 2 might be a promising candidate as an efficient nanosensor to detect such toxic gas in dry environment.

36 MATERIALS SCIENCE↗

Toxicity Warning Badge

Kennedy Space Center contracted GMD Systems, Inc., now Bacharach, Inc., to design a system for monitoring personnel exposure to hydrazine and monomethyl hydrazine, two dangerous gases which ignite on contact with an oxidizer. GMD developed a reliable colorimetric gas monitoring dosimeter for NASA, then modified it to create the commercial GMD 530 Series Hydrazine Badge. The badge has two separate paper tape chemistries which change color when the gases are detected, the density of the color being in proportion to the time of exposure and amount of gas in the air. The badge is used in facilities where hypergolic fuel is produced or used in support of space vehicles, satellites, missiles, and military aircraft auxiliary power units.

Source record↗

An application of a space technique for pollution detection.

Description of the hazardous gas detection system (HGDS) used during Apollo-Saturn launch tests for identifying and analyzing extremely minute amounts of gases escaping during cryogenic loading. These gases included hydrogen, helium, nitrogen, oxygen, nitrogen tetroxide, and hydrazine N2H3 radical. The heart of the HGDS is a mass spectrometer operating under high vacuum and capable to measure both qualitatively and quantitatively the presence and percentage of any gas whose molecular weight is between 2 and 150 atomic mass units. It is suggested that such a system could be utilized to detect environmental pollutants.

Hall, J. J.↗

Monitoring harmful gases

Instruments are developed for monitoring presence of hydrazine and nitrogen dioxide in air. Nitrogen dioxide and hydrazine are highly toxic and explosive substances used in propellants for rocket engines. Instruments discussed are inexpensive and most useful for detecting above substances in concentrations as low as few parts per million.

Helms, W. R.↗

Hypergolic Propellant Safety Course

Under the sponsorship of the NASA Safety Training Center at the Johnson Space Center, a hypergolic propellant safety course has been developed. This is a 2-day course on guidelines for hypergolic propellant system design, materials selection, operations, storage, and transportation. Recognizing that numerous fuels and oxidizers can be hypergolic, this course is specific to the hydrazine family of fuels and nitrogen tetroxide and its variants. The objectives of the course are to enable the student to identify and evaluate the hazards of hypergolic propellants, and to understand the methods for controlling those hazards and responding to emergencies. The course covers properties and hazards of the hydrazines and oxidizers; design and operations in hypergolic facilities; materials selection for use in hypergol systems; storage vessels, piping, and component considerations; hypergol detection; fire fighting practices; operating and transportation principles and procedures; and emergency practices and considerations. A hazards analysis methodology is presented. Numerous references are provided and the applicability of certain regulatory documents is discussed. A brief overview of other propellants, including hydrogen peroxide, is given at the end of the course.

Rathgeber, Kurt A.↗

A high throughput assay to detect enzymatic polyethylene oxidation

Biological plastics deconstruction and upcycling have emerged as sustainable alternatives to traditional recycling technologies for plastics waste. The discovery and engineering of efficient thermostable poly(ethylene terephthalate) (PET) hydrolases have made biological PET recycling possible at scale; however, enzymes for non-PET plastics, which account for approximately 70% of all plastics produced, remain largely undiscovered. To accelerate the discovery of such enzymes, we develop a high-throughput screen to detect initial polymer oxidation, specifically that of the C-H bond to an aldehyde. We test 4-hydrazino-7-nitro-2,1,3-benxoxadiozole hydrazine (NBD-H), which reacts with generated aldehydes to form a fluorescent hydrazone on plasma oxidized low-density polyethylene (LDPE) films. Hydrazone generation correlated well with the area of aldehyde peaks as measured by Fourier Transform Infrared Spectroscopy (FTIR) (R2 = 0.92). Moreover, we demonstrate that the probe reliably identifies LDPE-active dye decolorizing peroxidases (DyPs) that generate aldehydes on LDPE films (1.7 – 3.0 fold change relative to background), serving as an effective screen as demonstrated by receiver operating characteristic area under the curve of 0.95. Furthermore, this assay offers an LDPE oxidation screening platform that can be readily parallelized and automated for accelerated discovery of enzymes involved in polyolefin deconstruction.

biocatalysis↗

Recent Developments in Chemically Reactive Sensors for Propellants

Propellant system leaks can pose a significant hazard in aerospace operations. For example, a leak in the hydrazine supply system of the shuttle auxiliary power unit (APU) has resulted in hydrazine ignition and fire in the aft compartment of the shuttle. Sensors indicating the location of a leak could provide valuable information required for operational decisions. WSTF has developed a small, single-use sensor for detection of propellant leaks. The sensor is composed of a thermistor bead coated with a substance which is chemically reactive with the propellant. The reactive thermistor is one of a pair of closely located thermistors, the other being a reference. On exposure to the propellant, the reactive coating responds exothermically to it and increases the temperature of the coated-thermistor by several degrees. The temperature rise is sensed by a resistive bridge circuit, and an alarm is registered by data acquisition software. The concept is general and has been applied to sensors for hydrazine, monomethylhydrazine, unsym-dimethylhydrazine, ammonia, hydrogen peroxide, ethanol, and dinitrogen tetroxide. Responses of these sensors to humidity, propellant concentration, distance from the liquid leak, and ambient pressure levels arc presented. A multi-use sensor has also been developed for hydrazine based on its catalytic reactivity with noble metals.

Davis, Dennis D.↗

Vibrational Dynamics and Phase Transitions of Hydrazine to 50 GPa

The high pressure behavior of hydrazine, N 2 H 4 , has been investigated to 50 GPa at room temperature using infrared and Raman spectroscopy to explore pressure induced phase transitions and changes in hydrogen bonding. Three solid–solid phase transitions were detected at 11, 21, and 32 GPa on room temperature compression through dramatic changes in the lattice vibration and N–H stretching regions with increasing pressure in both measurement techniques. The transition to phase IV, which appears at 32 GPa, exhibits increased hydrogen bonding with significant hysteresis, persisting to 9 GPa on decompression. This work presents a detailed analysis of the pressure dependence of mode shifts and calculations of mode Grüneisen parameters as well as a determination of an approximate thermodynamic Grüneisen parameter. We compare these results to the behavior of other small molecular materials such as ammonia and water and explore the evolution of hydrogen bonding in hydrazine toward the symmetrically hydrogen bonded state, which has previously been suggested by theoretical computations.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Test program to demonstrate the stability of hydrazine in propellant tanks

The suitability of stainless steels and Inconel for long-term hydrazine propellant-storage tanks is investigated. Rectangular coupon samples cut from propellent tanks were sealed with a measured amount of hydrazine in glass capsules, stored at 43 or 60 C, and removed after 6 to 24 months, when corrosion of the coupon and decomposition of the hydrazine was determined, and SEM and electron spectroscopy were performed on some coupons. Corrosion was found to be unmeasurably low for all the coupons, and hydrazine decomposition produced less than 1.0 cu cm of gas per sq cm of wetted surface per year, except in those few cases when catalysis or contamination were detected. Especially good stability was observed for type 304L stainless steel. The decomposition rates determined in the coupon tests are confirmed by preliminary results of actual tank storage trials.

Moran, C. M.↗

Automated eddy current inspection of Space Shuttle APU turbine wheel blades

An automated inspection system based on eddy current testing (ET) techniques has been developed to inspect turbine wheel blades on the APU used in NASA's Space Transportation system. The APU is a hydrazine-powered gas turbine with a 15-cm diameter Rene 41 turbine wheel, which has 123 first-stage blades and 123 second-stage blades. The flaw detection capability of the ET system is verified through comparison with fluorescent penetrant test results. Results of the comparison indicate that ET is capable of inspecting surfaces with very restrictive geometries. The ET capability requires development of probes with extremely small coils to allow inspection within 0.4 mm of the blade root and the leading and trailing edges of the blade and within a height restriction of less than 1 mm. The color 2D presentation of the ET data provided crack-growth pattern and length information similar to those found with visual techniques. It also provided visual clues to minimize geometry effects such as generated from blade edges, a neighoring blade, and changes in the blade thickness.

Fisher, Jay L.↗

Sample Diluter for Detecting Hypergolic Propellants and Other Toxic or Hazardous Gases

Hardware was developed to dilute vapor samples of purged hypergolic propellants (with air) into the range of existing instruments for detection of such toxic vapors. Since these detectors are normally used to monitor at the threshold limit value (TLV), most do not have quantitative capability at percent levels which relate to lower explosion limit (LEL) and fire hazards. For example, the upper limits of Energetic Sciences (ESI) 6000 series detectors used at KSC are 200 parts per million (ppm) for monomethyl hydrazine (MMH) and 500 ppm for nitrogen dioxide (NO2) arising from decomposition of nitrogen tetroxide (N2O4). Orbiter Processing Facility (OPF) personnel servicing Shuttle thrusters need to measure up to 250 ppm MMH and 7500 ppm NO2 with portable, intrinsically safe instruments. Our objective was to quickly fabricate a sample diluter out of existing materials as a temporary measure while other parallel efforts were conducted to provide a commercial or in-house-developed instrument to detect high propellant levels. A 3 to 1 diluter would bring 500 ppm MMH into the range of the existing fuel ESI, and a 30 to 1 diluter would do the same for NO2. In this way, familiar equipment already available would be used, resulting in minimal paperwork, safety, and training impacts and low cost. An MMH vapor sample-diluter was constructed from a 1/4-inch Kynar tee, along with specially designed lengths of sample and dilution tubing. The sample line was 3 feet of Bev-A-Line 4, 1/4 inch tube leading to the straight run of the tee. The side run of the tee had a 17-inch length of Bev-A-Line 4, 1/4-inch tube, for nominal 3 to 1 dilution. A gas sample bag was prepared and assayed at 113 ppm MMH, and diluted vapor sarnples were assayed at 39.5 ppm, or a measured dilution of 2.9 to 1. For NO2, a 316 stainless steel (SS) 1/8-inch tee with 49.5 inches of coiled, 1/8-inch outside diameter (OD) 316 SS tubing was used as the sarnpling end of the dilution system. The side run of the tee was open. The measured dilution ratio, based on the input value of 6,480 ppm NO2 and the average output value of 233 ppm, was 28 to 1. Thus, sample-diluters were successful in diluting concentrated hypergolic propellant vapors, both MMH and N2O4, into the ranges of existing TLV detectors.

Barile, R. G.↗

Sample Diluter for Detecting Hypergolic Propellants and Other Toxic or Hazardous Gases

Hardware was developed to dilute vapor samples of purged hypergolic propellants (with air) into the range of existing instruments for detection of such toxic vapors. Since these detectors are normally used to monitor at the threshold limit value (TLV), most do not have quantitative capability at percent levels which relate to lower explosion limit (LEL) and fire hazards. For example, the upper limits of Energetic Sciences (ESI) 6000 series detectors used at KSC are 200 parts per million (ppm) for monomethyl hydrazine (MMH) and 500 ppm for nitrogen dioxide (NO2) arising from decomposition of nitrogen tetroxide (N2O4). Orbiter Processing Facility (OPF) personnel servicing Shuttle thrusters need to measure up to 250 ppm MMH and 7,500 ppm NO2 with portable, intrinsically safe instruments. Our objective was to quickly fabricate a sample diluter out of existing materials as a temporary measure while other parallel efforts were conducted to provide a commercial or in-house-developed instrument to detect high propellant levels. A 3 to 1 diluter would bring 500 ppm MMH into the range of the existing fuel ESI, and a 30 to 1 diluter would do the same for NO2. In this way, familiar equipment already available would be used, resulting in minimal paperwork, safety, and training impacts and low cost. An MMH vapor sample-diluter was constructed from a 1/4-inch Kynar tee, along with specially designed lengths of sample and dilution tubing. The sample line was 3 feet of Bev-A-Line 4, 1/4-inch tube leading to the straight run of the tee. The side run of the tee had a 17-inch length of Bev-A-Line 4, 1/4-inch tube, for nominal 3 to 1 dilution. A gas sample bag was prepared and assayed at 113 ppm ppm MMH, and diluted vapor samples were assayed at 39.5 ppm, or a measured dilution of 2.9 to 1. For NO2, a 316 stainless steel (SS) 1/8-inch tee with 49.5 inches of coiled, 1/8-inch outside diameter (OD) 316 SS tubing was used as the sampling end of the dilution system. The side run of the tee was open. The measured dilution ratio, based on the input value of 6,480 ppm NO2, and the average output value of 233 ppm, was 28 to 1. Thus, sample-diluters were successful in diluting concentrated hypergolic propellant vapors, both MMH and N2O4 into the ranges of existing TLV detectors.

Barile, R. G.↗

Update on Chemical Analysis of Recovered Hydrazine Family Fuels for Recycling

The National Aeronautics and Space Administration, Kennedy Space Center, has developed a program to re-use and/or recycle hypergolic propellants recovered from propellant systems. As part of this effort, new techniques were developed to analyze recovered propellants. At the 1996 PDCS, the paper 'Chemical Analysis of Recovered Hydrazine Family Fuels For Recycling' presented analytical techniques used in accordance with KSC specifications which define what recovered propellants are acceptable for recycling. This paper is a follow up to the 1996 paper. Lower detection limits and response linearity were examined for two gas chromatograph methods.

Davis, C. L.↗