Search NASA⌕ Search

SEARCH · Search NASA

Results for “AM Part Cleaning”

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 91 records · Page 5
All sourcesNASA NTRSDOE OSTI
NASA NTRS2002

Development of Metal-impregnated Single Walled Carbon Nanotubes for Toxic Gas Contaminant Control in Advanced Life Support Systems

The success of physico-chemical waste processing and resource recovery technologies for life support application depends partly on the ability of gas clean-up systems to efficiently remove trace contaminants generated during the process with minimal use of expendables. Carbon nanotubes promise superior performance over conventional approaches to gas clean-up due to their ability to direct the selective uptake of gaseous species based on their controlled pore size, high surface area, ordered chemical structure that allows functionalization and their effectiveness also as catalyst support materials for toxic gas conversion. We present results and findings from a preliminary study on the effectiveness of metal impregnated single walled nanotubes as catalyst/catalyst support materials for toxic gas contaminate control. The study included the purification of single walled nanotubes, the catalyst impregnation of the purified nanotubes, the experimental characterization of the surface properties of purified single walled nanotubes and the characterization of physisorption and chemisorption of uptake molecules.

Pisharody, Suresh A.↗
NASA NTRS2010

Supercritical CO2 Cleaning for Planetary Protection and Contamination Control

We have designed and built a prototype Supercritical CO? Cleaning (SCC) system at JPL. The key features of the system are: 1) the parts inside a high-pressure vessel can be rotated at high speeds; 2) the same thermodynamic condition is maintained during First-In First-Out flushing to keep solvent power constant; and 3) the boil-off during decompression is induced in a separate vessel downstream. Our goal is to demonstrate SCC's ability to remove trace amounts of microbial and organic contaminants down to parts per billion levels from spacecraft material surfaces for future astrobiology missions. The initial cleaning test results showed that SCC can achieve cleanliness levels of 0.01 microgram/cm(sup 2) or less for hydrophobic contaminants such as dioctyl phthalate and silicone and it is less effective in the removal and inactivation of the hydrophilic bacterial spores as expected. However, with the use of a polar co-solvent, the efficacy may improve dramatically. The same results were obtained using liquid CO?. This opens up the possibility of using subcritical cleaning conditions, which may prove to be more compatible with certain spacecraft hardware.

Lin, Ying↗
NASA NTRS2018

Curating NASA's Past, Present, and Future Extraterrestrial Sample Collections

As codified in NASA Policy Directive 7100.10F, the Astromaterials Acquisition and Curation Office at NASA Johnson Space Center (hereafter JSC Curation) is charged with curation of all extraterrestrial material under NASA control, including future NASA missions. JSC Curation curates all or part of nine astromaterial collections in seven clean room suites: (1) Apollo Samples (1969; ISO 6-7), (2) Luna Samples (from USSR; 1972; ISO 7), (3) Antarctic Meteorites (1976; ISO 7), (4) Cosmic Dust (1981; ISO 5), (5) Microparticle Impact Collection (formerly called Space Exposed Hardware; 1985; ISO 5), (6) Genesis Solar Wind Atoms (2004; ISO 4); (7) Stardust Comet Particles (2006; ISO 5), (8) Stardust Interstellar Particles (2006; ISO 5), (9) Hayabusa Asteroid Particles (from JAXA; 2010; ISO 5). In addition to the labs that house the samples, we have installed and maintained a wide variety of facilities and infrastructure required to support the clean-rooms: more than 10 different HEPA-filtered air-handling systems, ultrapure dry gaseous nitrogen systems, an ultrapure water system (UPW) and cleaning facilities to provide clean tools and equipment for the labs. We also have sample preparation facilities for making thin sections, microtome sections, and even focused ion-beam (FIB) sections to meet the research requirements of scientists. To ensure that we are keeping the samples as pristine as possible, we routinely monitor the cleanliness of our clean rooms and infrastructure systems. This monitoring includes: daily monitoring of the quality of our UPW, weekly airborne particle counts in the labs, monthly monitoring of the stable isotope composition of the gaseous N2 system, and annual measurements of inorganic or organic contamination in processing cabinets. We track within our databases the current and ever-changing characteristics of more than 250,000 individual samples across our various collections (including the 19,141 samples on loan to 433 Principal Investigators in 24 countries). The next sample return missions that NASA will participate in are Hayabusa2 and OSIRIS-REx (Origins Spectral Interpretation Resource Identification Security - Regolith Explorer). The designs for a new state-of-the-art suite of clean rooms to house these samples at JSC have been finalized. This includes separate ISO class 5 clean rooms to house each collection, a common ISO class 7 area for general use, an ISO class 7 microtome laboratory, and a separate thin section lab. Additionally, a new cleaning facility is being designed and procedures developed that will allow for enhanced cleaning of cabinets and tools in an inorganically, organically, and biologically clean manner. We are also designing a large multi-purpose Advanced Curation laboratory that will allow us to develop the techniques necessary to fully support the Hayabusa2 and OSIRIS-REx missions, as well as future possible sample return missions (e.g., Lunar Polar Volatiles, Mars, Comet Surface). A micro-CT (micro Computed Tomography) laboratory dedicated to the study of astromaterials has come online within JSC Curation, and we plan to add additional facilities that will enable non-destructive (or minimally-destructive) analyses of astromaterials in the near future (e.g., micro-XRF (micro X-Ray Fluorescence), confocal imaging Raman Spectroscopy). These facilities will be available to: (1) develop sample handling and storage techniques for future sample return missions, (2) be utilized by PET (Positron Emission Tomography) for future sample return missions, (3) for retroactive PET-style analyses of our existing collections, and (4) for periodic assessments of the existing sample collections.

Zeigler, Ryan A.↗
NASA NTRS2007

Clean Assembly of Genesis Collector Canister for Flight: Lessons for Planetary Sample Return

Measurement of solar composition in the Genesis collectors requires not only high sensitivity but very low blanks; thus, very strict collector contamination minimization was required beginning with mission planning and continuing through hardware design, fabrication, assembly and testing. Genesis started with clean collectors and kept them clean inside of a canister. The mounting hardware and container for the clean collectors were designed to be cleanable, with access to all surfaces for cleaning. Major structural components were made of aluminum and cleaned with megasonically energized ultrapure water (UPW). The UPW purity was >18 M resistivity. Although aluminum is relatively difficult to clean, the Genesis protocol achieved level 25 and level 50 cleanliness on large structural parts; however, the experience suggests that surface treatments may be helpful on future missions. All cleaning was performed in an ISO Class 4 (Class 10) cleanroom immediately adjacent to an ISO Class 4 assembly room; thus, no plastic packaging was required for transport. Persons assembling the canister were totally enclosed in cleanroom suits with face shield and HEPA filter exhaust from suit. Interior canister materials, including fasteners, were installed, untouched by gloves, using tweezers and other stainless steel tools. Sealants/lubricants were not exposed inside the canister, but vented to the exterior and applied in extremely small amounts using special tools. The canister was closed in ISO Class 4, not to be opened until on station at Earth-Sun L1. Throughout the cleaning and assembly, coupons of reference materials that were cleaned at the same time as the flight hardware were archived for future reference and blanks. Likewise reference collectors were archived. Post-mission analysis of collectors has made use of these archived reference materials.

Allton, J. H.↗
NASA NTRS2000

Cleaning at the Edge of Science: NASA's Genesis Mission

As part of NASA's continuing exploration of the origins of our solar system, the California Institute of Technology, Jet Propulsion Laboratory, Lockheed Martin Astronautics, Los Alamos National Laboratory, and the Johnson Space Center are working together to develop the Genesis mission to return solar matter for analysis in terrestrial laboratories. These samples will be used to define a baseline for the chemical and isotopic composition of the solar nebula. Deviations from the baseline resulted as the solar system evolved; thus, providing a tracer for materials incorporated into meteorites, comets and planetary bodies. These differences represent "fossil residues" that provide invaluable insight into how the solar nebula evolved to form the planets. We cannot collect a sample of the Sun as we would for a planet; fortunately, solar material comes to us in the form of the solar wind. Ultrapure materials will be exposed at the Earth-Sun L1, outside the Earth's magnetic influence, where solar wind nuclei will be captured for 2 years before returning to Earth in January 2001. The key challenge to obtaining a good sample of solar wind, uncontaminated by terrestrial atoms, is a clean collection surface in a clean sample canister and clean facilities with which to handle the samples for allocation and future reference. The Johnson Space Center QSQ is responsible for contamination control for the mission, for ensuring the cleanliness of collection surfaces and providing a clean environment for their subsequent handling. The level of cleanliness required is high; at the time of analysis (after sample return), the surface contamination by C, N, O must each be less than 10(exp 15) atoms per centimeter squared and for elements other than C, N, O, the number of atoms per centimeter squared of each surface contaminant shall not exceed the estimated solar wind fluence of the species (varies by element between U at approx. 10 (exp 4) atoms per centimeter squared to Fe, Si, Mg, and Ne at approx. 10(exp 12), atoms per centimeter squared). Typical spacecraft assembly is done in class 10,000 cleanrooms. The final cleaning and reintegration of the Genesis payload canister as well as all sample material handling will be done within a class 10 cleanroom using Dryden suits to protect the collector materials from any human debris. Each component is unique, no standard size, shape, material, or precleaning history. We are developing new final cleaning techniques utilizing ultra-pure water to minimize molecular residues on the hardware components.

Stansbery, Eileen K.↗
NASA NTRS1998

Balanced Rotating Spray Tank and Pipe Cleaning and Cleanliness Verification System

A system for cleaning and verifying the cleanliness of the interior surfaces of hollow items, such as small bottles, tanks, pipes and tubes, employs a rotating spray head for supplying a gas-liquid cleaning mixture to the item's surface at a supersonic velocity. The spray head incorporates a plurality of nozzles having diverging cross sections so that the incoming gas-liquid mixture is first converged within the spray head and then diverged through the nozzles, thereby accelerating the mixture to a supersonic velocity. In the preferred embodiment, three nozzles are employed; one forwardly facing nozzle at the end of the spray head and two oppositely facing angled nozzles exiting on opposite sides of the spray head which balance each other, and therefore impart no net side load on the spray head. A drive mechanism is provided to rotate the spray head and at the same time move the head back and forth within the item to be cleaned. The drive mechanism acts on a long metal tube to which the spray head is fixed, and thus no moving parts are exposed to the interior surfaces of the items to be cleaned, thereby reducing the risk of contamination.

Caimi, Raoul E. B.↗
NASA NTRS2014

ToF-SIMS Investigation of the Effectiveness of Acid-Cleaning procedures for Genesis Solar Wind Collectors

ToF-SIMS images of Genesis sample surfaces contain an incredible amount of important information, but they also show that the crash-derived surface contamination has many components, presenting a challenge to cleaning. Within the variability, we have shown that there are some samples which appear to be clean to begin with, e.g. 60471, and some are more contaminated. Samples 60493 and 60500 are a part of a focused study of the effectiveness of aqua regia and/or sulfuric acid cleaning of small flight Si implanted with Li-6 using ToF-SIMS.

Goreva, Y. S.↗
DOE OSTI2024

Methods to Track Effective Doses from Airborne Radioactive Emissions for Compliance with 40 CFR 61, SUBPART H

US Department of Energy national laboratories can play an integral role in not only the advancement of science but also in the treatment of various medical conditions through research and development activities conducted at radioisotope production facilities. Here, a project has been underway at Oak Ridge National Laboratory since 2016 whose mission is to produce and supply the radioisotope 227 Ac, which is used in a radiopharmaceutical developed to treat certain types of prostate cancer and bone metastases. Production activities result in the environmental release of airborne radioactive emissions, which are governed by Clean Air Act regulations described in 40 CFR Part 61, Subpart H. Stack 3039, the source that emits radioactive effluents from 227 Ac production, is subject to additional requirements outlined in American National Standards Institute (ANSI) N13.1-1969 due to its grandfathered status. Radioactive emissions are limited to levels below those that would cause annual compliance dose standards for members of the public to be exceeded and stack 3039 to lose its grandfathered status. To allow for maximum production of 227 Ac without exceeding relevant dose limits, monthly tracking of project emissions and resulting CAP88-PC modeled effective doses to a maximally exposed individual have been implemented. Four years of tracking data were compiled and analyzed to identify additional methods that could be used to estimate project doses more frequently, potentially further optimizing 227 Ac production while maintaining compliance with applicable regulations.

atmospheric emissions↗
DOE OSTI2024

First Measurement of Deeply Virtual Compton Scattering on the Neutron with Detection of the Active Neutron

Measuring deeply virtual Compton scattering (DVCS) on the neutron is one of the necessary steps to understand the structure of the nucleon in terms of generalized parton distributions (GPDs). Neutron targets play a complementary role to transversely polarized proton targets in the determination of the GPD E . This poorly known and poorly constrained GPD is essential to obtain the contribution of the quarks’ angular momentum to the spin of the nucleon. DVCS on the neutron was measured for the first time selecting the exclusive final state by detecting the neutron, using the Jefferson Lab longitudinally polarized electron beam, with energies up to 10.6 GeV, and the CLAS12 detector. The extracted beam-spin asymmetries, combined with DVCS observables measured on the proton, allow a clean quark-flavor separation of the imaginary parts of the Compton form factors H and E . Published by the American Physical Society 2024

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2024

North Birmingham Alternative Transportation Improvement Roadmap

The community of North Birmingham, Alabama, participated in the Communities LEAP pilot program. As part of this technical assistance pilot, the Alabama Clean Fuels Coalition conducted community engagement in the community to learn about the state of transportation and community priorities. This report highlights results and provides opportunities for improvements.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
NASA NTRS1990

Cleaning With Supercritical CO2

Supercritical carbon dioxide effective industrial cleaning agent. Replaces conventional halocarbon solvents for degreasing parts becoming coated with oil during such manufacturing procedures as forming and machining. Presents none of environmental threats and occupational hazards associated with halocarbon solvents. Spontaneously evaporates after use and leaves no waste to be disposed of. Evaporated gas readily collected and recycled.

Herzstock, James J.↗
NASA NTRS1996

Aqueous-Spray Cleaning System

Simple aqueous-spray cleaning system with overall dimensions comparable to large kitchen refrigerator constructed for use in cleaning hardware in shop. Made of commercially available parts and materials. Incorporates economical cleaner-and-rinse-recycling subsystem, as well as programmable logic-controller device for either manual or automatic operation.

Morgan, Gene E.↗
NASA NTRS2012

Understanding Differences in the Response to Composition Change as Simulated by CCMVal Models

Chemistry climate models (CCMs) have a common conceptual basis. Differences in implementation lead to differences in the stratospheric ozone response to changes in composition and climate. Although evaluation by CCMVal-2 identified strengths and weaknesses of participant models, the evaluation results were not used to discriminate among projections for future ozone evolution, at least in part because the overall diagnostic evaluation did not cleanly relate to the differences in CCM response. Here we use a subset of CCMVal diagnostics and additional analysis to understand the differences in response. In the upper stratosphere, differences in simulated temperature and total odd nitrogen prior to increases in chlorine loading explain the large differences in CCM sensitivity. In the lower atmosphere, there are two principle contributions to differences in CCM sensitivity to chlorine and climate change. First, differences in the lower stratospheric ClO affect simulated sensitivity to chlorine. CCMs with best transport performance match NDACC column HCl measurements at a broad range of latitudes. Other CCMs disagree with observations due to differences in total inorganic chlorine, partitioning between HCl and ClONO2, or both. Differences in ClONO2 are directly related to differences in simulated ClO. Second, although all CCMs predict increased tropical upwelling, the rate of increase varies and contributes to differences in tropical ozone and the 60N-60S column average.

Douglass, Anne R.↗
NASA NTRS1990

Improved Radiography Of Wooden Parts

Technique developed to increase radiographic contrasts of inherent latent defects in wood. Involves introduction of radiopaque substance into defect site and subjecting site to penetrating radiation. Radiopaque penetrant used is commercially available fluorocarbon cleaning solvent, trichlorotrifluoroethane. Applicable in inspection of wooden aircraft components, fan and wind-turbine blades, marine parts, insulators, and other wooden components, assemblies, and structures.

Berry, Maggie L.↗
DOE OSTI2025

Review of Presentation by Carter Wolf

The presentation was informative on the different techniques used to study the electronic dynamics of materials on the femtosecond scale, such as ARPES and TR ARPES. The presentation also discussed in depth code analysis, and the procedure used to remove noise from noisy data via machine learning procedures. The presentation first focused on an overview of the ARPES technique, and how TR-ARPES differs from it. The presentation then explored computational techniques used for fitting ARPES and TR-ARPES data, using the pyARPES framework. After that, the presentation discussed machine learning approaches for denoising noisy data such as Noise2Noise and Noise2Self. The main issue of denoising existing ARPES data and the necessity of machine learning approaches due to the lack of clean ARPES data were very clearly articulated as a major part of the project. The implementation, training and refinement and optimization were clearly detailed, along with a full documentation of attempts that worked and attempts that did not, thus thoroughly and clearly showing the research process. Experimental techniques regarding ARPES were also briefly documented.

36 MATERIALS SCIENCE↗
NASA NTRS1989

Whistle Gauge Measures Flow And Temperature

Simple, rugged gauge used to measure speed of flow and temperature of steam or other gas flowing through pipes of arbitrary diameter, from 1 to 28 in. or larger. Specially designed, instrumented whistle - has no moving parts, small, nonobstruction, operates at high temperature and pressure, and cleans itself. Does not operate at zero flow, but at moderate flows (tens of meters per second) generates intense sound for use in measurements. Consists of slanted ring groove of depth D and pressure taps in wall of pipe carrying flow to be measured. Resonant wavelength of sound generated by ring groove depends primarily on size and shape of groove and approximately equal to 4D.

Shakkottai, Parthasarathy↗
NASA NTRS1997

Developing a Stand Alone Sun Photometer for Ships and Buoys

During November and December 1995 the first Aerosol Characterization Experiment (ACE 1) was carried to characterize the aerosol physical and optical properties in the clean marine atmosphere near Tasmania in the South Pacific. As part of this effort, and with funding from this proposal, we installed a sun photometer on the R/V Discoverer and a spectro-photometer on the NOAA C-130 aircraft.

Porter, John N.↗