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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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At least 253 records · Page 14

All sources NASA NTRS DOE OSTI

NASA NTRS2014

MicroRNA Expression Profiles in Cultured Human Fibroblasts in Space

Microgravity, or an altered gravity environment from the static 1g, has been shown to influence global gene expression patterns and protein levels in living organisms. However, it is unclear how these changes in gene and protein expressions are related to each other or are related to other factors regulating such changes. A different class of RNA, the small non-coding microRNA (miRNA), can have a broad effect on gene expression networks by mainly inhibiting the translation process. Previously, we investigated changes in the expression of miRNA and related genes under simulated microgravity conditions on the ground using the NASA invented bioreactor. In comparison to static 1 g, simulated microgravity altered a number of miRNAs in human lymphoblastoid cells. Pathway analysis with the altered miRNAs and RNA expressions revealed differential involvement of cell communication and catalytic activity, as well as immune response signaling and NGF activation of NF-kB pathways under simulated microgravity condition. The network analysis also identified several projected networks with c- Rel, ETS1 and Ubiquitin C as key factors. In a flight experiment on the International Space Station (ISS), we will investigate the effects of actual spaceflight on miRNA expressions in nondividing human fibroblast cells in mostly G1 phase of the cell cycle. A fibroblast is a type of cell that synthesizes the extracellular matrix and collagen, the structural framework for tissues, and plays a critical role in wound healing and other functions. In addition to miRNA expressions, we will investigate the effects of spaceflight on the cellular response to DNA damages from bleomycin treatment.

Wu, Honglu↗

NASA NTRS2014

Non-Spherical Microcapsules for Increased Core Content Volume Delivery

The goal of this project was to advance microencapsulation from the standard spherical microcapsule to a non-spherical, high-aspect ratio (HAR), elongated microcapsule. This was to be accomplished by developing reproducible methods of synthesizing or fabricating robust, non-spherical, HAR microcapsules. An additional goal of this project was to develop the techniques to the point where scale-up of these methods could be examined. Additionally, this project investigated ways to apply the microencapsulation techniques developed as part of this project to self-healing formulations.

Technology Portfolio System↗

NASA NTRS2014

Novel Wiring Technologies for Aerospace Applications

Because wire failure in aerospace vehicles could be catastrophic, smart wiring capabilities have been critical for NASA. Through the years, researchers at Kennedy Space Center (KSC) have developed technologies, expertise, and research facilities to meet this need. In addition to aerospace applications, NASA has applied its knowledge of smart wiring, including self-healing materials, to serve the aviation industry. This webinar will discuss the development efforts of several wiring technologies at KSC and provide insight into both current and future research objectives.

novel↗

NASA NTRS2014

Heterogeneous Wireless Mesh Network Technology Evaluation for Space Proximity and Surface Applications

NASA has identified standardized wireless mesh networking as a key technology for future human and robotic space exploration. Wireless mesh networks enable rapid deployment, provide coverage in undeveloped regions. Mesh networks are also self-healing, resilient, and extensible, qualities not found in traditional infrastructure-based networks. Mesh networks can offer lower size, weight, and power (SWaP) than overlapped infrastructure-perapplication. To better understand the maturity, characteristics and capability of the technology, we developed an 802.11 mesh network consisting of a combination of heterogeneous commercial off-the-shelf devices and opensource firmware and software packages. Various streaming applications were operated over the mesh network, including voice and video, and performance measurements were made under different operating scenarios. During the testing several issues with the currently implemented mesh network technology were identified and outlined for future work.

DeCristofaro, Michael A.↗

NASA NTRS2014

Recent Developments on Microencapsulation for Autonomous Corrosion Protection

This work concerns recent progress in the development of a multifunctional smart coating based on microencapsulation for the autonomous control of corrosion. Microencapsulation allows the incorporation of desired corrosion control functionalities, such as early corrosion detection and inhibition through corrosion controlled release of corrosion indicators and inhibitors, as well as self-healing agent release when mechanical damage occurs.While proof-of-concept results have been reported previously, more recent efforts have been concentrated in technical developments to improve coating compatibility, synthesis procedure scalability, as well as fine tuning the release property of encapsulated active agents.

Corrosion↗

NASA NTRS2015

Random Vibration Testing of Advanced Wet Tantalum Capacitors

Advanced wet tantalum capacitors allow for improved performance of power supply systems along with substantial reduction of size and weight of the systems that is especially beneficial for space electronics. Due to launch-related stresses, acceptance testing of all space systems includes random vibration test (RVT). However, many types of advanced wet tantalum capacitors cannot pass consistently RVT at conditions specified in MIL-PRF-39006, which impedes their use in space projects. This requires a closer look at the existing requirements, modes and mechanisms of failures, specifics of test conditions, and acceptance criteria. In this work, different lots of advanced wet tantalum capacitors from four manufacturers have been tested at step stress random vibration conditions while their currents were monitored before, during, and after the testing. It has been shown that the robustness of the parts and their reliability are mostly due to effective self-healing processes and limited current spiking or minor scintillations caused by RVT do not increase the risk of failures during operation. A simple model for scintillations events has been used to simulate current spiking during RVT and optimize test conditions. The significance of scintillations and possible effects of gas generation have been discussed and test acceptance criteria for limited current spiking have been suggested.

cracking↗

NASA NTRS2015

Bioreactor Yields Extracts for Skin Cream

Johnson Space Flight Center researchers created a unique rotating-wall bioreactor that simulates microgravity conditions, spurring innovations in drug development and medical research. Renuèll Int'l Inc., based in Aventure, Florida, licensed the technology and used it to produce a healing skin care product, RE`JUVEL. In a Food and Drug Administration test, RE`JUVEL substantially increased skin moisture and elasticity while reducing dark blotches and wrinkles.

Source record↗

NASA NTRS2015

Creep Behavior and Durability of Cracked CMC

To understand failure mechanisms and durability of cracked Ceramic matrix composites (CMCs), Melt Infiltration (MI) SiCSiC composites with Sylramic-iBN fibers and full Chemical vapour infiltration SiCSiC composites with Sylramic-ion bombarded BN (iBN) and Hi-Nicalon -S fibers were pre-cracked between 150 to 200 megapascal and then creep and Sustained Peak Low Cycle Fatigue (SPLCF) tested at 13150 C at stress levels from 35 to 103 megapascal for up to 200 hours under furnace and burner rig conditions. In addition creep testing was also conducted on pre-cracked full Chemical vapour infiltration SiCSiC composites at 14500 C between 35 and 103 megapascal for up to 200 hours under furnace conditions. If the specimens survived the 200 hour durability tests, then they were tensile tested at room temperature to determine their residual tensile properties. The failed specimens were examined by Scanning electron microscope (SEM) to determine the failure modes and mechanisms. The influence of crack healing matrix, fiber types, crack density, testing modes and interface oxidation on durability of cracked Ceramic matrix composites (CMCs) will be discussed.

Creep↗

NASA NTRS2015

Omics Research on the International Space Station

The International Space Station (ISS) is an orbiting laboratory whose goals include advancing science and technology research. Completion of ISS assembly ushered a new era focused on utilization, encompassing multiple disciplines such as Biology and Biotechnology, Physical Sciences, Technology Development and Demonstration, Human Research, Earth and Space Sciences, and Educational Activities. The research complement planned for upcoming ISS Expeditions 45&46 includes several investigations in the new field of omics, which aims to collectively characterize sets of biomolecules (e.g., genomic, epigenomic, transcriptomic, proteomic, and metabolomic products) that translate into organismic structure and function. For example, Multi‐Omics is a JAXA investigation that analyzes human microbial metabolic cross‐talk in the space ecosystem by evaluating data from immune dysregulation biomarkers, metabolic profiles, and microbiota composition. The NASA OsteoOmics investigation studies gravitational regulation of osteoblast genomics and metabolism. Tissue Regeneration uses pan‐omics approaches with cells cultured in bioreactors to characterize factors involved in mammalian bone tissue regeneration in microgravity. Rodent Research‐3 includes an experiment that implements pan‐omics to evaluate therapeutically significant molecular circuits, markers, and biomaterials associated with microgravity wound healing and tissue regeneration in bone defective rodents. The JAXA Mouse Epigenetics investigation examines molecular alterations in organ specific gene expression patterns and epigenetic modifications, and analyzes murine germ cell development during long term spaceflight. Lastly, Twins Study ("Differential effects of homozygous twin astronauts associated with differences in exposure to spaceflight factors"), NASA's first foray into human omics research, applies integrated analyses to assess biomolecular responses to physical, physiological, and environmental stressors associated with spaceflight.

Love, John↗

NASA NTRS2011

VESGEN Mapping of Bioactive Protection against Intestinal Inflammation: Application to Human Spaceflight and ISS Experiments

Challenges to successful space exploration and colonization include adverse physiological reactions to micro gravity and space radiation factors. Constant remodeling of the microvasculature is critical for tissue preservation, wound healing, and recovery after ischemia. Regulation of the vascular system in the intestine is particularly important to enable nutrient absorption while maintaining barrier function and mucosal defense against micro biota. Although tremendous progress has been made in understanding the molecular circuits regulating neovascularization, our knowledge of the adaptations of the vascular system to environmental challenges in the intestine remains incomplete. This is in part because of the lack of methods to observe and quantify the complex processes associated with vascular responses in vivo. Developed by GRC as a mature beta version, pre-release research software, VESsel GENeration Analysis (VESGEN) maps and quantifies the fractal-based complexity of vascular branching for novel insights into the cytokine, transgenic and therapeutic regulation of angiogenesis, lymphangiogenesis and microvascular remodeling. Here we demonstrate that VESGEN can be used to characterize the dynamic vascular responses to acute intestinal inflammation and mucosal recovery from in vivo confocal microscopic 3D image series. We induced transient intestinal inflammation in mice by DSS treatment and investigated whether the ability of the pro biotic yeast Saccharomyces boulardii (Sb) to protect against intestinal inflammation was due to regulation of vascular remodeling. A primary characteristic of inflammation is excessive neovascularization (angiogenesis) resulting in fragile vessels prone to bleeding. Morphological parameters for triplicate specimens revealed that Sb treatment greatly reduced the inflammatory response of vascular networks by an average of 78%. This resulted from Sb inhibition of vascular endothelial growth factor receptor signaling, a major angiogenesis signaling pathway. It needs to be determined whether pro biotic yeast represents a promising approach to GI protection in space. GRC performed only the VESGEN post-testing analysis.

Parsons-Wingerter, P. A.↗

NASA NTRS2015

Random Vibration Testing of Advanced Wet Tantalum Capacitors

cracking↗

NASA NTRS2015

Transient Gene and miRNA Expression Profile Changes of Confluent Human Fibroblast Cells in Space

Microgravity or an altered gravity environment from the static 1 gravitational constant has been shown to influence global gene expression patterns and protein levels in cultured cells. However, most of the reported studies conducted in space or using simulated microgravity on the ground have focused on the growth or differentiation of the cells. Whether non-dividing cultured cells will sense the presence of microgravity in space has not been specifically addressed. In an experiment conducted on the International Space Station, confluent human fibroblast cells were fixed after being cultured in space for 3 and 14 days for investigations of gene and miRNA (microRNA) expression profile changes in these cells. A fibroblast is a type of cell that synthesizes the extracellular matrix and collagen, the structural framework for tissues, and plays a critical role in wound healing and other functions. Results of the experiment showed that on Day 3, both the flown and ground cells were still proliferating slowly even though they were confluent, as measured by the expression of the protein Ki-67 positive cells, and the cells in space grew slightly faster. Gene and miRNA expression data indicated activation of NF(sub kappa)B (nuclear factor kappa-light-chain-enhancer of activated B cells) and other growth related pathways involving HGF and VEGF in the flown cells. On Day 14 when the cells were mostly non-dividing, the gene and miRNA expression profiles between the flight and ground samples were indistinguishable. Comparison of gene and miRNA expressions in the Day 3 samples in respect to Day 14 revealed that most of the changes observed on Day 3 were related to cell growth for both the flown and ground cells. Analysis of cytoskeleton changes by immunohistochemistry staining of the cells with antibodies for alpha-tubulin showed no difference between the flight and ground samples. Results of our study suggest that in true non-dividing human fibroblast cells, microgravity in space has little effect on the gene and miRNA expression. Gene and miRNA expression changes were observed in cells that were confluent, but still proliferating slowly. The faster growth in the flown cells was associated with the activation of NF(sub kappa)B pathways which triggers the expression of several growth factors and the suppression of the cell cycle checkpoint.

Zhang, Ye↗

NASA NTRS2015

NASA and ESA Collaboration on Hexavalent Chrome Alternatives - Pretreatments with Primers Screening Final Test Report

Hexavalent chromium (hex chrome or Cr(VI)) is a widely used element within applied coating systems because of its self-healing and corrosion-resistant properties. The replacement of hex chrome in the processing of aluminum for aviation and aerospace applications remains a goal of great significance. Aluminum is the major manufacturing material of structures and components in the space flight arena. The National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA) are engaged in a collaborative effort to test and evaluate alternatives to hexavalent chromium containing corrosion coating systems. NASA and ESA share common risks related to material obsolescence associated with hexavalent chromium used in corrosion-resistant coatings. In the United States, Occupational Safety and Health Administration (OSHA) studies have concluded that hexavalent chromium is carcinogenic and poses significant risk to human health. On May 5, 2011, amendments to the Defense Federal Acquisition Regulation Supplement (DFARS) were issued in the Federal Register. Subpart 223.73 prohibits contracts from requiring hexavalent chromium in deliverables unless certain exceptions apply. Subpart 252.223-7008 provides the contract clause prohibiting contractors and subcontractors from using or delivering hexavalent chromium in a concentration greater than 0.1 percent by weight for all new contracts associated with supplies, maintenance and repair services, and construction materials. ESA faces its own increasingly stringent regulations within European directives such as Registration, Evaluation, Authorization and Restriction of Chemical (REACH) substances and the Restriction of Hazardous Substances Directive (RoHS) which have set a mid-2017 sunset date for hexavalent chromium. NASA and ESA continue to search for an alternative to hexavalent chromium in coatings applications that meet their performance requirements in corrosion protection, cost, operability, and health and safety, while typically specifying that performance must be equal to or greater than existing systems. The overall objective of the collaborative effort between NASA TEERM and ESA is to test and evaluate coating systems (pretreatments, pretreatments with primer, and pretreatments with primer and topcoat) as replacements for hexavalent chrome coatings in aerospace applications. This objective will be accomplished by testing promising coatings identified from previous NASA, ESA, Department of Defense (DOD), and other project experience. Additionally, several new materials will be analyzed according to ESA-identified specifications.

coating↗

NASA NTRS2015

The Development of 2700-3000 F Environmental Barrier Coatings for SiC/SiC Ceramic Matrix Composites: Challenges and Opportunities

Environmental barrier coatings (EBCs) and SiCSiC ceramic matrix composites (CMCs) systems will play a crucial role in future turbine engines for hot-section component applications because of their ability to significantly increase engine operating temperatures, reduce engine weight and cooling requirements. The development of prime-reliant environmental barrier coatings is a key to enable the applications of the envisioned 2700-3000F EBC - CMC systems to help achieve next generation engine performance and durability goals. This paper will primarily address the performance requirements and design considerations of environmental barrier coatings for turbine engine applications. The emphasis is placed on current NASA candidate environmental barrier coating systems for SiCSiC CMCs, their performance benefits and design limitations in long-term operation and combustion environments. The efforts have been also directed to developing prime-reliant, self-healing 2700F EBC bond coat; and high stability, lower thermal conductivity, and durable EBC top coats. Major technical barriers in developing environmental barrier coating systems, the coating integrations with next generation CMCs having the improved environmental stability, cyclic durability, erosion-impact resistance, and long-term system performance will be described. The research and development opportunities for turbine engine environmental barrier coating systems by utilizing improved compositions, state-of-the-art processing methods, and simulated environment testing and durability modeling will be discussed.

CMAS Resistance↗

NASA NTRS2015

Random Vibration Testing of Advanced Wet Tantalum Capacitors

wet tantalum capacitors↗

NASA NTRS2015

Characterization of Encapsulated Corrosion Inhibitors Containing Microparticles for Environmentally Friendly Smart Coatings

This poster presents the results obtained from experiments designed to evaluate the release properties, as well as the corrosion inhibition effectiveness, of several encapsulated corrosion inhibitors. Microencapsulation has been used in the development of environmentally friendly multifunctional smart coatings. This technique enables the incorporation of autonomous corrosion detection, inhibition and self-healing functionalities into many commercially available coating systems. Select environmentally friendly corrosion inhibitors were encapsulated in organic and inorganic pH-sensitive microparticles and their release in basic solutions was studied. The release rate results showed that the encapsulation can be tailored from fast, for immediate corrosion protection, to slow, which will provide continued long-term corrosion protection. The incorporation of several corrosion inhibitor release profiles into a coating provides effective corrosion protection properties. To investigate the corrosion inhibition efficiency of the encapsulated inhibitors, electrochemical techniques were used to obtain corrosion potential, polarization curve and polarization resistance data. These measurements were performed using the free as well as the encapsulated inhibitors singly or in combinations. Results from these electrochemical tests will be compared to those obtained from weight loss and other accelerated corrosion experiments.

Coatings↗

NASA NTRS2015

Recent Developments on Autonomous Corrosion Protection Through Encapsulation

This paper concerns recent progress in the development of a multifunctional smart coating, based on microencapsulation, for the autonomous detection and control of corrosion. Microencapsulation has been validated and optimized to incorporate desired corrosion control functionalities, such as early corrosion detection and inhibition, through corrosion-initiated release of corrosion indicators and inhibitors, as well as self-healing agent release triggered by mechanical damage. While proof-of-concept results have been previously reported, more recent research and development efforts have concentrated on improving coating compatibility and synthesis procedure scalability, with a targeted goal of obtaining easily dispersible pigment-grade type microencapsulated materials. The recent progress has resulted in the development of pH-sensitive microparticles as a corrosion-triggered delivery system for corrosion indicators and inhibitors. The synthesis and early corrosion indication results obtained with coating formulations that incorporate these microparticles are reported. The early corrosion indicating results were obtained with color changing and with fluorescent indicators.

Autonomous↗

NASA NTRS2016

Hydrophobic-Core Microcapsules and Their Formation

Hydrophobic-core microcapsules and methods of their formation are provided. A hydrophobic-core microcapsule may include a shell that encapsulates a hydrophobic substance with a core substance, such as dye, corrosion indicator, corrosion inhibitor, and/or healing agent, dissolved or dispersed therein. The hydrophobic-core microcapsules may be formed from an emulsion having hydrophobic-phase droplets, e.g., containing the core substance and shell-forming compound, dispersed in a hydrophilic phase. The shells of the microcapsules may be capable of being broken down in response to being contacted by an alkali, e.g., produced during corrosion, contacting the shell.

Calle, Luz M.↗