SEARCH · Engineering Papers

Results for “nitrate removal”

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.

SourceResearch connectionFrom yearThrough year

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

65 records · Page 4

All sources NASA NTRS DOE OSTI

NASA NTRS1989

Filter measurement results from the Airborne Antarctic Ozone Experiment

Filter samples obtained as part of the AAOE to determine the total nitrate, sulfate, acidic chloride, and acidic fluoride content along the flight path of the NASA ER-2 are studied. These compounds were obtained in the aerosol and vapor phase. The ratio of particulate sulfate observed outside the chemically perturbed region (CPR) of the vortex to that inside the CPR was 2.6. The ratio of total acidic chloride to total acidic flouride within the CPR is near 1, indicating the removal of chloride from the air mass or the partitioning of chloride into an unmeasured species.

Gandrud, B. W.↗

NASA NTRS1992

Indications of photochemical histories of Pacific air masses from measurements of atmospheric trace species at Point Arena, California

Measurements were made of a suite of photochemically active trace species (including light hydrocarbons, ozone, peroxyacetyl nitrate, HNO3, NO3(-), NO(x), and NO(y)) in marine air collected during a 10-day period in April and May 1985 at Point Arena (California), a coastal inflow site. It was found that the mixing ratios of the alkanes, ozone, peroxyacetyl nitrate, and HNO3 correlated with variations in the origins of calculated air parcel trajectories and with variations in the ratios of the light alkanes. The highest levels of alkanes and the photochemical products were found in parcels that had been rapidly transported across the North Pacific Ocean from near the 600-mbar level above the east Asian coast. It is suggested that production over the continents, transport to the marine areas, and parallel removal processes account for much of the observed correlation.

Parrish, D. D.↗

NASA NTRS2018

Aiding in the Efforts of Bioregenerative Life Support for the Future Residents of Mars and Long-Duration Space Flights Plant Growth in Amended Martian Regolith Simulant

Currently, the goal of plant growth research at KSC (Kennedy Space Center) is to provide a sustainable source of healthy food on long-duration space flights so astronauts and future residents of Mars can get the nutrition they need and produce food, recycle the atmosphere, and aid in recycling water. The sustainable production of food will aid in the efforts of closed life support. Plants have a vital application for bioregenerative life support as demands for food and oxygen can be provided through photosynthesis, while the carbon dioxide from human respiration is removed. In order for a growing medium to provide for plant growth, it needs to provide support, oxygen, ions, and liquid to the plant. This summer research determines how amended Martian regolith simulant acts as a growing medium for plants through looking at the structural properties of each amendment. Mars is covered with regolith which is crushed volcanic rock that is composed of a high amount of perchlorate salts. The composition of Martian soil is such that it is roughly basaltic and consists of sulfur, nitrates, and oxychlorine species. Martian regolith simulants have been generated to further analyze plant growth and aim to replicate features of the reference sample. The JSC (Johnson Space Center) Mars-1A regolith simulant resembles Martian regolith at the Viking I landing site. The objectives of the research this summer at Kennedy Space Center are to devise a plant growth in amended JSC Mars-1A Martian regolith simulant and perform crop studies to assess the performance of full duration crop growth in amended Martian regolith simulant. This research will provide a deeper understanding of how the combination of soil amendments to Martian regolith has a synergistic effect on improving crop production The plant growth experiment will be completed with three treatments each containing inorganic and organic soil amendments.

Onsay, Daphne↗

NASA NTRS1993

Carbonates, surfates, phosphates, nitrates, and organic materials: Their association in a Martian meteorite

The debate concerning the evolution of CO2 on Mars continues. It would appear that in order to explain the valley networks and other relict fluvial landforms it is necessary to accept that liquid water was once present at the surface of Mars. This in turn requires, at some point in the planet's history, a higher surface temperature than exists today, proposition explained traditionally by an early dense CO2, atmosphere. However, there are a number of problems with this notion: for instance, CO2 alone is not an efficient greenhouse gas because of its tendency to form clouds. Moreover, if there was an early dense CO2 atmosphere, it is necessary to explain where the elemental constituents now reside. There are two possibilities for the latter, namely loss to outer space of atmospheric CO2 or the formation of vast carbonate deposits. While some models of atmospheric loss predict that up to 0.4 bar of CO2 could be removed from the Martian surface, this is still not enough to account for the original atmospheric inventory, usually considered to have been in the range of 1-5 bar. Thus, most models of the evolution of the Martian surface require removal of CO2 from the atmosphere and into carbonate deposits. However, as yet, the evidence for the existence of carbonates on Mars is fairly scant. This is an issue that would have been resolved by results obtained from Mars Observer.

Wright, I. P.↗

NASA NTRS1991

New evidence for a dramatic rise in atmosphere oxygen ca. 1,900 m.y. ago

Several lines of geologic evidence have pointed to a significant increase in P sub O2 about 2,000 m.y. ago, but the magnitude of P sub O2 before and after that time has been quite uncertain. The data that we have recently accumulated suggest that P sub O2 was approximately less than 2 x 10 (exp -3) atm more than 2,000 m.y. ago, and approximately greater than 0.03 atm more recently than ca. 1,900 m.y. ago. These estimates are based on the behavior of iron in Precambrian weathering horizons. More than ca. 2,000 m.y. ago, Fe(+2), released during the weathering of basalts was not oxidized to Fe(+3), and was removed in ground water from the upper layers of soil horizons. More recently than ca. 1,850 m.y. ago, Fe(+2) was oxidized to Fe(+3) and precipitated as iron oxides and hydroxides in such soil horizons and in the weathering products of a carbonate facies banded iron formation in Griqualand West, South Africa. The O2 content of the atmosphere must have increased dramatically about 1,900 m.y. ago to explain these observations. The reasons for the increase are still obscure, but are probably related to changes in the biologic productivity of the oceans. Eukaryotes appear to have developed shortly after the increase in P sub O2, perhaps in response to the subsequent increase in the supply of nitrate from the atmosphere to the oceans.

Holland, H. D.↗

NASA NTRS1987

Antarctic stratospheric chemistry of chlorine nitrate, hydrogen chloride, and ice - Release of active chlorine

The reaction rate between atmospheric hydrogen chloride (HCl) and chlorine nitrate (ClONO2) is greatly enhanced in the presence of ice particles; HCl dissolves readily into ice, and the collisional reaction probability for ClONO2 on the surface of ice with HCl in the mole fraction range from about 0.003 to 0.010 is in the range from about 0.05 to 0.1 for temperatures near 200 K. Chlorine is released into the gas phase on a time scale of at most a few milliseconds, whereas nitric acid (HNO3), the other product, remains in the condensed phase. This reaction could play an important role in explaining the observed depletion of ozone over Antarctica; it releases photolytically active chlorine from its most abundant reservoir species, and it promotes the formation of HNO3 and thus removes nitrogen dioxide from the gas phase. Hence it establishes the necessary conditions for the efficient catalytic destruction of ozone by halogenated free radicals.

Molina, Mario J.↗

NASA NTRSDate not supplied

Plasma Activated Water Developments for Lunar and Martian Applications

Plasma activated water (PAW) would be of great use for space applications, due to the myriad of on-demand uses. Some of these applications were directly explored at NASA’s Kennedy Space Center including: Space crop production, Martian systems, and acid-base production. The presence of any nitrogen in the gas stream, including in a simulated Martian atmospheric composition, allows for nitrates to form in water during plasma treatment. These nitrates form nitric acid and drive down the pH while also being in a readily useable form by plants. Inedible biomass ash, which can be created using the same plasma system that treats the water, can be added into the acidic PAW to raise the pH. Measured pH values ranged from 2.7 to 11.5 using this process. Both the nitrates and the nutrients from the inedible biomass are beneficial for the plants, and the pH control allows for use with many different plant species. This methodology is also enabling for space-based hydroponic systems. At KSC, growth studies of Cherry Belle radishes showed comparable dry masses of edible biomass grown with Hoagland’s nutrient solution (a best-case scenario solution that is impractical for launch transportation) and the edible biomass grown with plasma water with the added ash. Both solutions showed substantial improvements over the deionized water that is most similar to what is available in Space systems via the water processor assembly. Additionally, the ability to produce both acidic PAW and basic PAW has benefits for sanitation as well. Preliminary studies showed a 5.8 log reduction of P. Aeruginosa when exposed to PAW mixtures, which shows the ability to remove this common biofilm.

Ryan Patrick Gott↗

NASA NTRSDate not supplied

Plasma Activated Water Developments for Lunar and Martian Applications

Plasma activated water (PAW) could be of great use for space applications, due to the myriad of on-demand uses. The presence of any nitrogen in the gas stream, including in a simulated Martian atmospheric composition, allows for nitrates to form in water during plasma treatment. These nitrates form nitric acid and drive down the pH while also being in a readily useable form by plants. By varying the reactions and mixing in natural additives, pH values from 2.7 to 11.5 were achieved. The pH control allows for use with many different plant species. This methodology is also enabling for space-based hydroponic systems. Growth studies of Cherry Belle radishes showed comparable dry masses of edible biomass grown with Hoagland’s nutrient solution (a best-case scenario solution that is impractical for launch transportation) and the edible biomass grown with PAW. Both solutions showed substantial improvements over the deionized water that is most similar to what is available in Space systems via the water processor assembly. Additionally, the ability to produce both acidic PAW and basic PAW has benefits for sanitation as well. Preliminary studies showed a 5.8 log reduction of P. Aeruginosa when exposed to PAW mixtures, which shows the ability to remove this common biofilm.

Ryan Gott↗

NASA NTRS1996

Chemical Characterization and Reactivity Testing of Fuel-Oxidizer Reaction Product (Test Report)

The product of incomplete reaction of monomethylhydrazine (MMH) and nitrogen tetroxide (NTO) propellants, or fuel-oxidizer reaction product (FORP), has been hypothesized as a contributory cause of an anomaly which occurred in the chamber pressure (PC) transducer tube on the Reaction Control Subsystem (RCS) aft thruster 467 on flight STS-51. A small hole was found in the titanium-alloy PC tube at the first bend below the pressure transducer. It was surmised that the hole may have been caused by heat and pressure resulting from ignition of FORP. The NASA Johnson Space Center (JSC) White Sands Test Facility (WSTF) was requested to define the chemical characteristics of FORP, characterize its reactivity, and simulate the events in a controlled environment which may have lead to the Pc-tube failure. Samples of FORP were obtained from the gas-phase reaction of MMH with NTO under laboratory conditions, the pulsed firings of RCS thrusters with modified PC tubes using varied oxidizer or fuel lead times, and the nominal RCS thruster firings at WSTF and Kaiser-Marquardt. Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), accelerating rate calorimetry (ARC), ion chromatography (IC), inductively coupled plasma (ICP) spectrometry, thermogravimetric analysis (TGA) coupled to FTIR (TGA/FTIR), and mechanical impact testing were used to qualitatively and quantitatively characterize the chemical, thermal, and ignition properties of FORP. These studies showed that the composition of FORP is variable but falls within a limited range of compositions that depends on the fuel loxidizer ratio at the time of formation, composition of the post-formation atmosphere (reducing or oxidizing), and reaction or postreaction temperature. A typical composition contains methylhydrazinium nitrate (MMHN), ammonium nitrate (AN), methylammonium nitrate (MAN), and trace amounts of hydrazinium nitrate and 1,1-dimethylhydrazinium nitrate. The thermal decomposition reactions of FORP compositions used in this study were unremarkable, Neither the various compositions of FORP, the pure major components of FORP, nor mixtures of FORP with propellant-system corrosion products showed any unusual thermal activity when decomposed under laboratory conditions. Off-limit thruster operations were simulated by rapid mixing of liquid MMH and liquid NTO in a confined space. The test hardware was constructed with pressure- and temperature-measurement devices to determine if the expected fuel oxidizer reaction would result in increased energy release when FORP, FORP constituents, or propellant-system corrosion products were present. These tests demonstrated that FORP, MMHN, AN, or Inconel corrosion products can induce a mixture of MMH and NTO to produce component-damaging energies. The simulation-test program was not extensive enough to provide statistical probabilities for these events but did show that such events can occur. Damaging events required FORP or metal salts to be present at the initial mixing of MMH and NTO. Based on the results of these studies, it is suggested that removal or mitigation of a buildup of these materials may decrease the incidence of these high-energy, potentially damaging events.

Source record↗

NASA NTRS2015

Predicting the Mineral Composition of Dust Aerosols: Representing Key Processes - Part 1

Soil dust aerosols created by wind erosion are typically assigned globally uniform physical and chemical properties within Earth system models, despite known regional variations in the mineral content of the parent soil. Mineral composition of the aerosol particles is important to their interaction with climate, including shortwave absorption and radiative forcing, nucleation of cloud droplets and ice crystals, heterogeneous formation of sulfates and nitrates, and atmospheric processing of iron into bioavailable forms that increase the productivity of marine phytoplankton. Here, aerosol mineral composition is derived by extending a method that provides the composition of a wet-sieved soil. The extension accounts for measurements showing significant differences between the mineral fractions of the wetsieved soil and the emitted aerosol concentration. For example, some phyllosilicate aerosols are more prevalent at silt sizes, even though they are nearly absent at these diameters in a soil whose aggregates are dispersed by wet sieving. We calculate the emitted mass of each mineral with respect to size by accounting for the disintegration of soil aggregates during wet sieving. These aggregates are emitted during mobilization and fragmentation of the original undispersed soil that is subject to wind erosion. The emitted aggregates are carried far downwind from their parent soil. The soil mineral fractions used to calculate the aggregates also include larger particles that are suspended only in the vicinity of the source. We calculate the emitted size distribution of these particles using a normalized distribution derived from aerosol measurements. In addition, a method is proposed for mixing minerals with small impurities composed of iron oxides. These mixtures are important for transporting iron far from the dust source, because pure iron oxides are more dense and vulnerable to gravitational removal than most minerals comprising dust aerosols. A limited comparison to measurements from North Africa shows that the model extensions result in better agreement, consistent with a more extensive comparison to global observations as well as measurements of elemental composition downwind of the Sahara, as described in companion articles.

aerosols↗

NASA NTRS2011

Coupled Aerosol-Chemistry-Climate Twentieth-Century Transient Model Investigation: Trends in Short-Lived Species and Climate Responses

The authors simulate transient twentieth-century climate in the Goddard Institute for Space Studies (GISS) GCM, with aerosol and ozone chemistry fully coupled to one another and to climate including a full dynamic ocean. Aerosols include sulfate, black carbon (BC), organic carbon, nitrate, sea salt, and dust. Direct and BC snow-albedo radiative effects are included. Model BC and sulfur trends agree fairly well with records from Greenland and European ice cores and with sulfur deposition in North America; however, the model underestimates the sulfur decline at the end of the century in Greenland. Global BC effects peak early in the century (1940s); afterward the BC effects decrease at high latitudes of the Northern Hemisphere but continue to increase at lower latitudes. The largest increase in aerosol optical depth occurs in the middle of the century (1940s-80s) when sulfate forcing peaks and causes global dimming. After this, aerosols decrease in eastern North America and northern Eurasia leading to regional positive forcing changes and brightening. These surface forcing changes have the correct trend but are too weak. Over the century, the net aerosol direct effect is -0.41 Watts per square meter, the BC-albedo effect is -0.02 Watts per square meter, and the net ozone forcing is +0.24 Watts per square meter. The model polar stratospheric ozone depletion develops, beginning in the 1970s. Concurrently, the sea salt load and negative radiative flux increase over the oceans around Antarctica. Net warming over the century is modeled fairly well; however, the model fails to capture the dynamics of the observedmidcentury cooling followed by the late century warming.Over the century, 20% of Arctic warming and snow ice cover loss is attributed to the BC albedo effect. However, the decrease in this effect at the end of the century contributes to Arctic cooling. To test the climate responses to sulfate and BC pollution, two experiments were branched from 1970 that removed all pollution sulfate or BC. Averaged over 1970-2000, the respective radiative forcings relative to the full experiment were +0.3 and -0.3 Watts per square meter; the average surface air temperature changes were +0.2 degrees and -0.03 C. The small impact of BC reduction on surface temperature resulted from reduced stability and loss of low-level clouds.

Koch, Dorothy↗