Investigation of multilayer printed circuit board materials
Fabrication and environmental tests of circuit boards with polyimide plastic dielectrics and pyrolyzed polyacrylonitrile conductors
Meinhard, J. E.↗
SEARCH · Engineering Papers
Results for “ENVIRONMENTAL MATERIALS”
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.
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Environmental Control Systems
Materials illustrating a presentation on environment control systems for electric flight systems are presented. Schematics and flow diagrams of fresh air source and air conditioning systems, and vapor cycle and air cycle parts lists are presented.
Rosenbush, F. M.↗
An Overview of Nuclear Thermal Rocket Element Environmental Simulator (NTREES) Capabilities, Upgrades, and Overlaps in Advanced Material Testing Areas
The Nuclear Thermal Rocket Element Environmental Simulator (NTREES) was designed to perform non-nuclear testing of nuclear thermal rocket (NTR) fuel elements and materials. NTREES can simulate the thermal hydraulic environment within the reactor of an NTR and has been leveraged to provide data on the thermochemical, thermomechanical and thermohydraulic performance of components and materials. Active upgrades to the NTREES facility include installing a DC power supply for DC powered joule heating, a supply gas chiller for a cryogenically cool gas supply, gas pre-heaters with sample holders for testing samples too small to be inductively heated by bathing them in hot gas, and a high temperature digital image correlation (DIC) capability for measuring high temperature strains real time. In addition to NTR testing, given the commonality of high enthalpy flow environments between the reactor of an NTP engine and the aerothermal heating of high-speed flight, the unique capabilities of NTREES to provide high temperature gas flows at high pressure without combustion or electrode spallation byproducts may lend itself to additional usage of the facility beyond the original intent.
Michael P Schoenfeld↗
Genesis Solar Wind Sample Curation Documentation
Introduction: A scientist with experience as a sample science analyst, provider of flight hardware for multiple missions, and senior engineer in an ISO 2000-rated manufacturing plant has described the timeline of key participants in any PI-led sample return mission, the breadth of the organizations involved [1,2], and, of interest to this meeting, choosing the types of data to preserve and issues of future data accessibility. This work broadens that perspective by giving similar lessons from Genesis sample curation point-of-view. Curation participation regarding data gathering was part of the mission review process from the beginning. Genesis’ story illustrates outcome of several choices about types of data to record and preserve. Precision analysis of solar wind atoms captured in pure, ultraclean substrates is the driving science goal; therefore, detailed documentation was captured from all mission and curation phases and from investigator laboratories because these processes affect the final analytical results [3]. Pre-flight: Design and fabrication of the spacecraft. Like many modern small sample return missions, Genesis was a tightly managed team integrated across science, engineering and curation. Communication across the team was excellent, and, for the most part, the hands-on engineering technicians understood the impacts of “small choices” they routinely make, and the eyes-on oversight of manufacturing processes by scientists was mindful of details. The payload was designed by the Jet Propulsion Laboratory and the spacecraft by Lockheed Martin. Solar wind collectors and instruments were fabricated by multiple vendors and laboratories. The main portion of the payload was assembled at JSC. Fabrication procedures and contamination-control data (with witness coupons) were stored primarily at JSC. The original composition, dimensions and configuration of components, results of thermal testing, etc. are still needed for interpretation of analytical data. At times, these must be estimated from secondary information acquired pre-flight. Moreover, some files (e.g., original 3-D models and early Powerpoint) cannot be opened using software. Archived curation data includes 2-D drawings, material usage lists, QA documentation and analyses of consumables used during fabrication. Important chemical information still resides in archived hardware, paints and lubricants, material coupons, cleaning coupons, environmental witness plates and reference materials from manufacturing facilities. Purity and cleanliness of collector substrates. Semi-conductor vendors provided surface cleanliness data and some purity data. Purity for specific elements of interest was verified by science team members in their laboratories [4]. Curation archived procurement and shipping records, analysis reports, and non-proprietary fabrication data. A physical archive of flight collector reference materials is maintained for future use so additional data can be collected as analytical techniques improve. These are of increased value due to the hard landing upon re-entry. Cleaning and cleanliness assessments of flight hardware. Cleaning of the science canister payload was performed at JSC in a dedicated ISO 4 cleanroom using ultrapure water (UPW). The cleanliness of this UPW was monitored throughout processing. The archive for the clean lab also includes airborne particle counts, airborne molecular and inorganic contamination measurements as well as cleanroom construction material coupons and witness coupons. Hardware cleanliness was assessed by particle counts in rinse water batches. This information is recorded in batch cleaning forms and logbooks, and are, perhaps, of decreased value due to the hard landing. Post-flight: Curation-generated data. The curation handling history of each Genesis sample is documented in a typical astromaterials sample database which captures sample location, physical description and characterization data. Samples have a “shelf life”. Crucial to the preservation of samples is ongoing documentation of the sample environment, initially under curatorial control but is now a separate facility function with requires coordination. PI-generated data. Data on sample characterization and cleaning techniques continues to be generated by sample users [5]. These are often captured in LPSC abstracts, but these “engineering” results often are not publishable as stand-alone papers. We are actively looking for ways to make this information more accessible to users. Ion implants into samples have aided science return and can be shared among investigators. These (and similar) materials should be added to the curatorial collection with appropriate process and characterization data generated externally. Summary: Complete data archives for returned astromaterial samples must be broad in types and formats, and inclusive of environmental monitoring.
Genesis↗
Adhesion in thermomechanically processed seaweed-lignocellulosic composite materials
The increasing concerns associated with petroleum-derived polymers motivate the development of sustainable, renewably sourced alternatives. In ubiquitous applications such as structural materials for infrastructure, the built environment as well as packaging, where natural materials such as wood are used, we rely on nonrenewable and nondegradable polymers to serve as adhesives. In wood panels, such as medium density fiberboards (MDFs), formaldehyde-based resins are predominantly used to bond wood fibers and to provide strength to the materials. To further mitigate the environmental impact of construction materials, more sustainable adhesives need to be investigated. Here, in this article, we introduce Ulva seaweed as an adhesive to enable cohesion and strength in hot-pressed wood panels. Upon hot-pressing, powdered Ulva flows in between the wood particles, generating a matrix, which provides strong binding. We show that the flexural strength of Ulva-bonded wood biocomposites increases with increasing Ulva concentrations. At an Ulva concentration of 40 wt%, our composites reach an average elastic modulus of 6.1 GPa, and flexural strength of 38.2 MPa (compared to 4.7 GPa and 22.6 MPa, respectively, for pure wood compressed at the same pressing conditions). To highlight the bonding mechanisms, we performed infrared and x-ray photoelectron spectroscopy and identified indications of fatty acid mobility during hot-pressing. In addition, we demonstrate that the presence of Ulva improves other properties of the composites such as water resistance and fame retardancy. Ulva is also shown to behave as an excellent adhesive agent between two prepressed beams. Finally, we perform an in-depth analysis of the environmental impact of wood-Ulva biocomposites.
36 MATERIALS SCIENCE↗
EVAPORATION EFFECTS ON MATERIALS IN SPACE
Vacuum environmental effects on the evaporation, sublimation and decomposition rates of materials for space application
SPACE ENVIRONMENT↗
Sample Identifiers and Metadata Reporting Format for Environmental Systems Science
The ESS-DIVE sample identifiers and metadata reporting format primarily follows the System for Earth Sample Registration (SESAR) Global Sample Number (IGSN) guide and template, with modifications to address Environmental Systems Science (ESS) sample needs and practicalities (IGSN-ESS). IGSNs are associated with standardized metadata to characterize a variety of different sample types (e.g. object type, material) and describe sample collection details (e.g. latitude, longitude, environmental context, date, collection method). Globally unique sample identifiers, particularly IGSNs, facilitate sample discovery, tracking, and reuse; they are especially useful when sample data is shared with collaborators, sent to different laboratories or user facilities for analyses, or distributed in different data files, datasets, and/or publications. To develop recommendations for multidisciplinary ecosystem and environmental sciences, we first conducted research on related sample standards and templates. We provide a comparison of existing sample reporting conventions, which includes mapping metadata elements across existing standards and Environment Ontology (ENVO) terms for sample object types and environmental materials. We worked with eight U.S. Department of Energy (DOE) funded projects, including those from Terrestrial Ecosystem Science and Subsurface Biogeochemical Research Scientific Focus Areas. Project scientists tested the process of registering samples for IGSNs and associated metadata in workflows for multidisciplinary ecosystem sciences. We provide modified IGSN metadata guidelines to account for needs of a variety of related biological and environmental samples. While generally following the IGSN core descriptive metadata schema, we provide recommendations for extending sample type terms, and connecting to related templates geared towards biodiversity (Darwin Core) and genomic (Minimum Information about any Sequence, MIxS) samples and specimens. ESS-DIVE recommends registering samples for IGSNs through SESAR, and we include instructions for registration using the IGSN-ESS guidelines. Our resulting sample reporting guidelines, template (IGSN-ESS), and identifier approach can be used by any researcher with sample data for ecosystem sciences.
54 ENVIRONMENTAL SCIENCES↗
Upper Temperature Limit of Environmental Barrier Coatings for Enabling Propulsion Materials Established
Silicon-based ceramics, such as SiC/SiC composites and Si3N4, are the prime candidates for hot section structural components of next-generation gas turbines. A key barrier to such an application is the rapid recession of silicon-based ceramics in combustion environments because of the volatilization of silica scale by water vapor (refs. 1 and 2). Environmental barrier coatings (EBC's) were developed to prevent recession in the High Speed Research--Enabling Propulsion Materials (HSR-EPM) Program (refs. 3 and 4). An investigation under the Ultra-Efficient Engine Technology Program was undertaken at the NASA Glenn Research Center to establish the upper temperature limit of the EPM EBC.
Lee, Kang N.↗
Characterization of Space Environmental Effects on Candidate Solar Sail Material
The National Aeronautics and Space Administration's (NASA) Marshall Space Flight Center (MSFC) is concentrating research into the utilization of photonic materials for spacecraft propulsion. Spacecraft propulsion, using photonic materials, will be achieved using a solar sail. A sail operates on the principle that photons, originating from the sun, impart pressure and provide a source of spacecraft propulsion. The pressure can be increased, by a factor of two if the sun-facing surface is perfectly reflective. Solar sails are generally composed of a highly reflective metallic front layer, a thin polymeric substrate, and occasionally a highly emissive back surface. The Space Environmental Effects Team at MSFC is actively characterizing candidate solar sail materials to evaluate the thermo-optical and mechanical properties after exposure to a simulated Geosynchronous Transfer Orbit (GTO) radiation environment. The technique of radiation dose verses material depth profiling was used to determine the orbital equivalent exposure doses. The solar sail exposure procedures and results of the material characterization will be discussed.
Edwards, David↗
Characterization of Space Environmental Effects on Candidate Solar Sail Material
The National Aeronautics and Space Administration's (NASA) Marshall Space Flight Center (MSFC) is concentrating research into the utilization of photonic materials for spacecraft propulsion. Spacecraft propulsion, using photonic materials, will be achieved using a solar sail. A solar sail operates on the principle that photons, originating from the sun, impart pressure to the sail and therefore provide a source for spacecraft propulsion. The pressure imparted to a solar sail can be increased, up to a factor of two if the sunfacing surface is perfectly reflective. Therefore, these solar sails are generally composed of a highly reflective metallic sun-facing layer, a thin polymeric substrate and occasionally a highly emissive back surface. The Space Environmental Effects Team, at MSFC, is actively characterizing candidate solar sail material to evaluate the thermo-optical and mechanical properties after exposure to radiation environments simulating orbital environments. This paper describes the results of three candidate materials after exposure to a simulated Geosynchronous Transfer Orbit (GTO). This is the first known characterization of solar sail material exposed to space simulated radiation environments. The technique of radiation dose versus material depth profiling was used to determine the orbital equivalent exposure doses. The solar sail exposure procedures and results of the material characterization will be discussed.
Edwards, David↗
Dynamic Modeling and Characterization of Nuclear-grade Graphite
Idaho National Labs serves as the spearhead for many innovative energy solutions to the world's energy crisis. One such solution is the INL's Microreactor which is designed to deploy to extreme/remote environments where other sources of power are either unavailable or unreliable. In order to best design these energy solutions for their operational environments, it is crucial to understand how the design, components, and materials will respond to the environmental conditions. One key material in these innovative designs is a nuclear-grade graphite known as PCEA. This study examines the behavior of PCEA graphite under dynamic loading, similar to that which may occur in extreme environments. The objective is to characterize the dynamic behavior and produce an accurate, reliable constitutive model suitable for use in simulation tools such as INL's MOOSE. Graphite specimens were tested using a Split Hopkinson Pressure Bar (SHPB) to administer the dynamic compressive load. The SHPB was charged at various pressures to produce a range of strain rates on the material in compression. Data was acquired via strain gauges on the SHPB setup, from which stress, strain, and time data were collected. Analysis revealed the stress-strain behavior of the material as well as insights into the material behavior's relationship to strain rate. Further work must continue to characterize the various other dynamic behaviors of the material which will combine to create a substantially trustworthy constitutive model for this grade of nuclear-grade graphite. Ultimately, this will allow for realistic simulation of the material in reactor designs, allowing for prediction of design weaknesses and leading to improved designs for increased resilience, security, and reliability.
22 GENERAL STUDIES OF NUCLEAR REACTORS↗
An Overview of Nanomaterials for Environmental Remediation Applications
The environmental remediation capabilities of nanoparticles were reviewed and evaluated. Nanoparticles (NPs) have been used to remediate various forms of environmental contamination. Various materials, morphologies, and conditions are required to remediate different contaminants. Nanoparticles may have benefits and/or limitations compared with traditional remediation methods. New techniques are being applied to mitigate the limitations of NPs. Nanomaterials are a promising technology for the environmental remediation. NPs have been used for the remediation of aqueous and atmospheric contaminants. Nanoparticles have been used to sequester contaminants toxic to human and environmental health. Various materials, morphologies, and conditions are necessary for the remediation of different contaminants. The remediation of heavy metals is of significant concern. Contaminants may be remediated by means of sorption or reduction. The remediation capability of nanoparticles is promising due to their high surface area and reactivity. Reaction kinetics are, therefore, notably fast. These characteristics make NPs attractive for environmental remediation. Various NPs have been used as sequestering agents for environmental contaminants. NPs have been used to remediate heavy metals as well as organic contaminants. Technical Objectives: Assess viability of nanoparticles (NPs) for environmental remediation; Review benefits and limitations of NPs; Design future experiments to test remediation capabilities of NPs. Future Plans: Create NP filters for remediation - Grow Au NPs on Stainless Steel Wool: Stainless steel wool has many defects and crevices allowing the Au NPs to grow on the surface; Stainless steel wool will not react with the heavy metal contaminants tested; NPs are embedded, so they do not have to be removed from solution. Test sorption capabilities with heavy metal contaminants in aqueous solution. Benefits of Gold NPs: Corrosion/oxidation resistant; Exhibit visible/near IR plasmon resonance; Can be synthesized by solution chemistry: cost efficient and easily scalable. Surfactants: Used to lower surface energy and prevent aggregation; Sodium citrate: anionic surfactant (-); Cetyltrimethylammonium bromide (CTAB): cationic surfactant (+); Ionic surfactants create charged NPs; Charged NPs can be used to sequester ionic contaminants (eg. heavy metals)
54 ENVIRONMENTAL SCIENCES↗
Environmental charging of spacecraft surfaces: Tests of thermal control materials for use on the global positioning system flight space vehicle. Part 1: Specimens 1 to 5
The NASA/USAF program on Environmental Charging of Spacecraft Surfaces consists of experimental efforts directed toward evaluating the response of materials to the environmental charged particle flux. Samples of thermal blankets and second surface mirrors of the type to be used on the Global Positioning System Flight Space Vehicle were tested to determine their response to electron flux. The primary result observed was that the ground connection of the metal layers of the blanket, as made by the baseline grounding technique using serrated washers and grommets, deteriorated with time at test. The discharges observed on the blankets were the glow type, not the 'lightning' strike observed on past specimens. Testing was performed at ambient laboratory temperatures.
Stevens, N. J.↗
Environmental Projects. Volume 9: Construction of hazardous materials storage facilities
Activities at the Goldstone Deep Space Communications Complex (GDSCC) are carried out in support of seven parabolic dish antennas. These activities may give rise to environmental hazards. This report is one in a series of reports describing environmental projects at GDSCC. The construction of two hazardous materials and wastes storage facilities and an acid-wash facility is described. An overview of the Goldstone complex is also presented along with a description of the environmental aspects of the GDSCC site.
Source record↗
Unlocking the magic in mycelium: Using synthetic biology to optimize filamentous fungi for biomanufacturing and sustainability
Filamentous fungi drive carbon and nutrient cycling across our global ecosystems, through its interactions with growing and decaying flora and their constituent microbiomes. The remarkable metabolic diversity, secretion ability, and fiber-like mycelial structure that have evolved in filamentous fungi have been increasingly exploited in commercial operations. The industrial potential of mycelial fermentation ranges from the discovery and bioproduction of enzymes and bioactive compounds, the decarbonization of food and material production, to environmental remediation and enhanced agricultural production. Despite its fundamental impact in ecology and biotechnology, molds and mushrooms have not, to-date, significantly intersected with synthetic biology in ways comparable to other industrial cell factories (e.g. Escherichia coli,Saccharomyces cerevisiae, and Komagataella phaffii). In this review, we summarize a suite of synthetic biology and computational tools for the mining, engineering and optimization of filamentous fungi as a bioproduction chassis. A combination of methods across genetic engineering, mutagenesis, experimental evolution, and computational modeling can be used to address strain development bottlenecks in established and emerging industries. These include slow mycelium growth rate, low production yields, non-optimal growth in alternative feedstocks, and difficulties in downstream purification. In the scope of biomanufacturing, we then detail previous efforts in improving key bottlenecks by targeting protein processing and secretion pathways, hyphae morphogenesis, and transcriptional control. Bringing synthetic biology practices into the hidden world of molds and mushrooms will serve to expand the limited panel of host organisms that allow for commercially-feasible and environmentally-sustainable bioproduction of enzymes, chemicals, therapeutics, foods, and materials of the future.
59 BASIC BIOLOGICAL SCIENCES↗
Exploring the Effect of EBC Composition on CMAS Wetting Behavior
Rare-earth disilicate (REDS) materials are existing materials used in environmental barrier coating (EBC) for the protection of structural materials in the hot-section of turbine engines. REDS interactions with molten calcium-magnesium-aluminosilicate (CMAS) debris are of interest to understand molten CMAS attack and improve CMAS mitigation strategies. This work assesses the effect of REDS composition on CMAS wetting by investigating wetting angle, spreading, and reactivity. Freestanding atmospheric plasma spray (APS) REDS coatings (for RE = Y, La, Nd, Gd, Yb, Lu) were exposed to 10 mg of CMAS (Ca33-Mg9-Al13-Si45 in single cation mol%) in stagnant lab air at 1250C. APS YbDS was compared to a dense spark plasma sintered (SPS) phase-pure Yb2Si2O7 and a nominal 20 vol% phase-mixture of Yb 2 SiO 5 in Yb 2 Si 2 O 7 (20YbMS/YbDS). CMAS mass was held constant but specimen surface areas varied, yielding a range of loading between ~6 and 10 mg/cm2. CMAS was loaded as a cylindrical rod atop the specimen surface, polished to 4000 grit, and heated to temperature in a Linseis L74/HS/1700 heating microscope. The heating microscope measured the evolution of molten CMAS diameter, height, and contact angle. Molten CMAS diameter at 1150C and contact angle measurements after two hours of exposure at 1250C yielded a positive trend with rare-earth cation size. There was no statistically significant difference in CMAS wetting behavior between SPS YbDS and 20YbMS/YbDS. Post-exposure specimens were examined in plan view and cross-section with XRD, SEM, and EDS. CMAS spreading was cross-examined using plan view SEM, while reactivity utilized plan view XRD and cross-sectional SEM/EDS.
Clark Luckhardt↗
LDEF materials overview
The flight and retrieval of the National Aeronautics and Space Administration's Long Duration Exposure Facility (LDEF) provided an opportunity for the study of the low-Earth orbit (LEO) environment and long-duration space environmental effects (SEE) on materials that is unparalleled in the history of the U.S. Space Program. The 5-year, 9-month flight of LDEF greatly enhanced the potential value of all materials on LDEF to the international SEE community, compared to that of the original 1-year flight plan. The remarkable flight attitude stability of LDEF enables specific analyses of individual and combined effects of LEO environmental parameters on identical materials on the same space vehicle. NASA recognized this potential by forming the LDEF Space Environmental Effects on Materials Special Investigation Group (MSIG) to address the greatly expanded materials and LEO space environment analysis opportunities available in the LDEF structure, experiment trays, and corollary measurements so that the combined value of all LDEF materials data to current and future space missions will be addressed and documented. An overview of the interim LDEF materials findings of the principal investigators and the Materials Special Investigation Group is provided. These revelations are based on observations of LEO environmental effects on materials made in space during LDEF retrieval and during LDEF tray deintegration at the Kennedy Space Center, and on findings of approximately 1.5 years of laboratory analyses of LDEF materials by the LDEF materials scientists. These findings were extensively reviewed and discussed at the MSIG-sponsored LDEF Materials Workshop '91. The results are presented in a format that categorizes the revelations as 'clear findings' or 'obscure preliminary findings' (and progress toward their resolution), plus resultant needs for new space materials developments and ground simulation testing/analytical modeling, in seven categories: materials/environmental parameters and data bases; LDEF contamination; thermal control coatings and protective treatments; polymers and films; polymer-matrix composites; metals, ceramics, and optical materials; and systems-related materials. The utilization of LDEF materials data for future low-Earth orbit missions is also discussed, concentrating on Space Station Freedom. In general, the LDEF data is remarkably consistent; LDEF will provide a 'benchmark' for materials design data bases for satellites in low-Earth orbit. Some materials were identified to be encouragingly resistant to LEO SEE for 5.8-years; other 'space qualified' materials displayed significant environmental degradation. General contamination levels on LDEF were low, but molecular contamination was widespread; LDEF offers an unprecedented opportunity to provide a unified perspective of unmanned LEO spacecraft contamination mechanisms. New material development requirements for long-term LEO missions were identified and current ground simulation testing methods/data for new, durable materials concepts can be validated with LDEF results. LDEF findings are already being integrated into the design of Space Station Freedom.
Stein, Bland A.↗
Environmental charging of spacecraft-tests of thermal control materials for use on the global positioning system flight space vehicle. Part 2: Specimen 6 to 9
The NASA/USAF program on the Environmental Charging of Spacecraft Surfaces consists, in part, of experimental efforts directed toward evaluating the response of materials to the environmental charged particle flux. Samples of thermal blankets of the type to be used on the Global Positioning System Flight Space Vehicles were tested to determine their response to electron flux. The primary result observed was that no discharges were obtained with the quartz-fiber-fabric-covered multilayer insulation specimen. The taped aluminized polyester grounding system used on all specimens did not appear to grossly deteriorate with time; however, the specimens require specific external pressure to maintain constant grounding system resistance.
Stevens, N. J.↗