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NASA NTRS2010

A Method to Estimate the Probability That Any Individual Cloud-to-Ground Lightning Stroke Was Within Any Radius of Any Point

A new technique has been developed to estimate the probability that a nearby cloud-to-ground lightning stroke was within a specified radius of any point of interest. This process uses the bivariate Gaussian distribution of probability density provided by the current lightning location error ellipse for the most likely location of a lightning stroke and integrates it to determine the probability that the stroke is inside any specified radius of any location, even if that location is not centered on or even within the location error ellipse. This technique is adapted from a method of calculating the probability of debris collision with spacecraft. Such a technique is important in spaceport processing activities because it allows engineers to quantify the risk of induced current damage to critical electronics due to nearby lightning strokes. This technique was tested extensively and is now in use by space launch organizations at Kennedy Space Center and Cape Canaveral Air Force station.

Huddleston, Lisa L.↗

NASA NTRS2011

A Method to Estimate the Probability that Any Individual Cloud-to-Ground Lightning Stroke was Within Any Radius of Any Point

Huddleston, Lisa↗

NASA NTRS2011

A Method to Estimate the Probability that any Individual Cloud-to-Ground Lightning Stroke was Within any Radius of any Point

A new technique has been developed to estimate the probability that a nearby cloud to ground lightning stroke was within a specified radius of any point of interest. This process uses the bivariate Gaussian distribution of probability density provided by the current lightning location error ellipse for the most likely location of a lightning stroke and integrates it to determine the probability that the stroke is inside any specified radius of any location, even if that location is not centered on or even with the location error ellipse. This technique is adapted from a method of calculating the probability of debris collision with spacecraft. Such a technique is important in spaceport processing activities because it allows engineers to quantify the risk of induced current damage to critical electronics due to nearby lightning strokes. This technique was tested extensively and is now in use by space launch organizations at Kennedy Space Center and Cape Canaveral Air Force Station. Future applications could include forensic meteorology.

Huddleston, Lisa L.↗

NASA NTRS2003

Expert Seeker

Expert Seeker is a computer program of the knowledge-management-system (KMS) type that falls within the category of expertise-locator systems. The main goal of the KMS system implemented by Expert Seeker is to organize and distribute knowledge of who are the domain experts within and without a given institution, company, or other organization. The intent in developing this KMS was to enable the re-use of organizational knowledge and provide a methodology for querying existing information (including structured, semistructured, and unstructured information) in a way that could help identify organizational experts. More specifically, Expert Seeker was developed to make it possible, by use of an intranet, to do any or all of the following: Assist an employee in identifying who has the skills needed for specific projects and to determine whether the experts so identified are available. Assist managers in identifying employees who may need training opportunities. Assist managers in determining what expertise is lost when employees retire or otherwise leave. Facilitate the development of new ways of identifying opportunities for innovation and minimization of duplicated efforts. Assist employees in achieving competitive advantages through the application of knowledge-management concepts and related systems. Assist external organizations in requesting speakers for specific engagements or determining from whom they might be able to request help via electronic mail. Help foster an environment of collaboration for rapid development in today's environment, in which it is increasingly necessary to assemble teams of experts from government, universities, research laboratories, and industries, to quickly solve problems anytime, anywhere. Make experts more visible. Provide a central repository of information about employees, including information that, heretofore, has typically not been captured by the human-resources systems (e.g., information about past projects, patents, or hobbies). Unify myriad collections of data into Web-enabled repository that could easily be searched for relevant data.

Fernandez, Becerra↗

NASA NTRS2012

A Probabilistic, Facility-Centric Approach to Lightning Strike Location

A new probabilistic facility-centric approach to lightning strike location has been developed. This process uses the bivariate Gaussian distribution of probability density provided by the current lightning location error ellipse for the most likely location of a lightning stroke and integrates it to determine the probability that the stroke is inside any specified radius of any location, even if that location is not centered on or even with the location error ellipse. This technique is adapted from a method of calculating the probability of debris collision~ith spacecraft. Such a technique is important in spaceport processing activities because it allows engineers to quantify the risk of induced current damage to critical electronics due to nearby lightning strokes. This technique was tested extensively and is now in use by space launch organizations at Kennedy Space Center and Cape Canaveral Air Force Station. Future applications could include forensic meteorology.

Huddleston, Lisa L.↗

NASA NTRS2015

Atmospheric Research 2014 Technical Highlights

Atmospheric research in the Earth Sciences Division (610) consists of research and technology development programs dedicated to advancing knowledge and understanding of the atmosphere and its interaction with the climate of Earth. The Division's goals are to improve understanding of the dynamics and physical properties of precipitation, clouds, and aerosols; atmospheric chemistry, including the role of natural and anthropogenic trace species on the ozone balance in the stratosphere and the troposphere; and radiative properties of Earth's atmosphere and the influence of solar variability on the Earth's climate. Major research activities are carried out in the Mesoscale Atmospheric Processes Laboratory, the Climate and Radiation Laboratory, the Atmospheric Chemistry and Dynamics Laboratory, and the Wallops Field Support Office. The overall scope of the research covers an end-to-end process, starting with the identification of scientific problems, leading to observation requirements for remote-sensing platforms, technology and retrieval algorithm development; followed by flight projects and satellite missions; and eventually, resulting in data processing, analyses of measurements, and dissemination from flight projects and missions. Instrument scientists conceive, design, develop, and implement ultraviolet, infrared, optical, radar, laser, and lidar technology to remotely sense the atmosphere. Members of the various Laboratories conduct field measurements for satellite sensor calibration and data validation, and carry out numerous modeling activities. These modeling activities include climate model simulations, modeling the chemistry and transport of trace species on regional-to-global scales, cloud resolving models, and developing the next-generation Earth system models. Satellite missions, field campaigns, peer-reviewed publications, and successful proposals are essential at every stage of the research process to meeting our goals and maintaining leadership of the Earth Sciences Division in atmospheric science research. Figure 1.1 shows the 20-year record of peer-reviewed publications and proposals among the various Laboratories. This data shows that the scientific work being conducted in the Laboratories is competitive with the work being done elsewhere in universities and other government agencies. The office of Deputy Director for Atmospheric Research will strive to maintain this record by rigorously monitoring and promoting quality while emphasizing coordination and integration among atmospheric disciplines. Also, an appropriate balance will be maintained between the scientists' responsibility for large collaborative projects and missions and their need to carry out active science research as a principal investigator. This balance allows members of the Laboratories to improve their scientific credentials, and develop leadership potentials. Interdisciplinary research is carried out in collaboration with other laboratories and research groups within the Earth Sciences Division, across the Sciences and Exploration Directorate, and with partners in universities and other government agencies. Members of the Laboratories interact with the general public to support a wide range of interests in the atmospheric sciences. Among other activities, the Laboratories raise the public's awareness of atmospheric science by presenting public lectures and demonstrations, by making scientific data available to wide audiences, by teaching, and by mentoring students and teachers. The Atmosphere Laboratories make substantial efforts to attract and recruit new scientists to the various areas of atmospheric research. We strongly encourage the establishment of partnerships with Federal and state agencies that have operational responsibilities to promote the societal application of our science products. This report describes our role in NASA's mission, provides highlights of our research scope and activities, and summarizes our scientists' major accomplishments during calendar year 2014. The composition of the organization is shown in Figure 1.2 for each code. This report is published in a printed version with an electronic version on our atmospheres Web site, http://atmospheres.gsfc.nasa.gov/.

Technical↗

NASA NTRS2002

High Abundance of Ions in Cosmic Ices

Water-rich, mixed molecular ices and polycyclic aromatic hydrocarbons (PAHs) are common throughout interstellar molecular clouds and the Solar System. Vacuum ultraviolet (VUV) irradiation and particle bombardment of these abiotic ices produces complex organic species, including important biogenic molecules such as amino acids and functionalized PAHs which may have played a role in the origin of life. This ability of such water-rich, oxygen dominated ices to promote production of complex organic species is surprising and points to an important, unusual, but previously overlooked mechanism at play within the ice. Here we report the nature of this mechanism using electronic spectroscopy. VUV-irradiation of PAH/H2O ices leads to an unprecedented and efficient (greater than 70 %) conversion of the neutral PAHs to their cation form (PAH+). Further, these H2O/PAH+ ices are stabile at temperatures below 50 K, a temperature domain common throughout interstellar clouds and the Solar System. Between 50 and 125 K they react to form the complex organics. In view of this, we conclude that charged PAHs and other molecular ions should be common and abundant in many cosmic ices. The chemical, spectroscopic and physical properties of these ion-rich ices can be of fundamental importance for objects as diverse as comets, planets, and molecular clouds and may account for several poorly understood phenomena associated with each of these object classes.

Gudipati, Murthy S.↗

NASA NTRS1992

Polarized-Cathodoluminescence Study Of Stress In GaAs/Si

Report describes experiments in which linearly polarized cathodoluminesce scanning electron microscopy, in both imaging and spectroscopic forms, used to analyze spatial variations in stress tensors in specimens of GaAs/Si. Specimens fabricated by atmospheric-pressure metallo-organic chemical vapor deposition of GaAs to thickness of 4 micrometers on Si substrates. Combination of mismatch between Si and GaAs crystal lattices and differential thermal contraction of materials from deposition temperature (700 degrees C) to room temperature gives rise to stresses in GaAs layer. Experiments conducted to contribute to understanding of effects of these stresses and ramifications thereof for fabrication of electronic devices in GaAs/Si system.

Rich, Daniel H.↗

NASA NTRS2005

The features of self-assembling organic bilayers important to the formation of anisotropic inorganic materials in microgravity conditions

Materials with directional properties are opening new horizons in a variety of applications including chemistry, electronics, and optics. Structural, optical, and electrical properties can be greatly augmented by the fabrication of composite materials with anisotropic microstructures or with anisotropic particles uniformly dispersed in an isotropic matrix. Examples include structural composites, magnetic and optical recording media, photographic film, certain metal and ceramic alloys, and display technologies including flat panel displays. The new applications and the need for model particles in scientific investigations are rapidly out-distancing the ability to synthesize anisotropic particles with specific chemistries and narrowly distributed physical characteristics (e.g. size distribution, shape, and aspect ratio).

Talham, Daniel R.↗

NASA NTRS1974

Experiments on the origin of molecular chirality by parity non-conservation during beta-decay

Experiments are described to test a theory for the origin of optical activity wherein the longitudinally polarized electrons resulting from parity violation during radioactive beta-decay, and their resulting circularly polarized bremsstrahlung, might interact asymmetrically with organic matter to yield optically active products. The historical background to this subject is briefly reviewed. Our experiments involve subjecting a number of racemic and optically active amino acid samples to a beta-radiation source for a period of 1.34 years (total dose: 411 Mrads), then examining them for any asymmetric effects by means of optical rotatory dispersion and analytical gas chromatography.

Bonner, W. A.↗

NASA NTRS1994

NASA/DOD Aerospace Knowledge Diffusion Research Project. Paper 39: The role of computer networks in aerospace engineering

This paper presents selected results from an empirical investigation into the use of computer networks in aerospace engineering. Such networks allow aerospace engineers to communicate with people and access remote resources through electronic mail, file transfer, and remote log-in. The study drew its subjects from private sector, government and academic organizations in the U.S. aerospace industry. Data presented here were gathered in a mail survey, conducted in Spring 1993, that was distributed to aerospace engineers performing a wide variety of jobs. Results from the mail survey provide a snapshot of the current use of computer networks in the aerospace industry, suggest factors associated with the use of networks, and identify perceived impacts of networks on aerospace engineering work and communication.

Bishop, Ann P.↗

NASA NTRS1994

NASA/CARES dual-use ceramic technology spinoff applications

NASA has developed software that enables American industry to establish the reliability and life of ceramic structures in a wide variety of 21st Century applications. Designing ceramic components to survive at higher temperatures than the capability of most metals and in severe loading environments involves the disciplines of statistics and fracture mechanics. Successful application of advanced ceramics material properties and the use of a probabilistic brittle material design methodology. The NASA program, known as CARES (Ceramics Analysis and Reliability Evaluation of Structures), is a comprehensive general purpose design tool that predicts the probability of failure of a ceramic component as a function of its time in service. The latest version of this software, CARESALIFE, is coupled to several commercially available finite element analysis programs (ANSYS, MSC/NASTRAN, ABAQUS, COSMOS/N4, MARC), resulting in an advanced integrated design tool which is adapted to the computing environment of the user. The NASA-developed CARES software has been successfully used by industrial, government, and academic organizations to design and optimize ceramic components for many demanding applications. Industrial sectors impacted by this program include aerospace, automotive, electronic, medical, and energy applications. Dual-use applications include engine components, graphite and ceramic high temperature valves, TV picture tubes, ceramic bearings, electronic chips, glass building panels, infrared windows, radiant heater tubes, heat exchangers, and artificial hips, knee caps, and teeth.

Powers, Lynn M.↗

NASA NTRS1999

Induction of Three-Dimensional Growth of Human Liver Cells in Simulated Microgravity

We previously reported that a NASA-developed bioreactor that simulates microgravity environment and creates the unique environment of low shear force and high-mass transfer is conducive for maintaining long term 3-D cell cultures of functional hepatocytes (60 days). However, significant further expansion of liver mass, or the remodeling of liver in vitro was jeopardized by the appearance of apoptotic zones in the center of large cell aggregates. To optimize oxygenation and nutritional uptake within growing cellular aggregates we cultured primary human liver cells (HLC) in a bioreactor in the presence or absence of microcarriers and biodegradable scaffolds. Also, to promote angiogenesis, HLC were cultured with or without microvascular endothelial cells. HLC were harvested from human livers by collagenase perfusion. While microcarriers did not affect cell growth, HLC cultured with biodegradable scaffolds made from polyglycolic acid (PGA) formed aggregates up to 3 cm in length. Culturing cells with PGA scaffolds increased the efficiency of cell self-assembly and the formation of larger cell aggregates. Based on histological evaluation it appears that the degree of apoptotic cells was diminished as compared to cultures without scaffolds. Histology of HLC with PGA-scaffolds revealed cell distribution between the fibers of the scaffolds, and cell-cell and cell-fiber interactions. Analyses of HLC spheroids revealed tissue-like structures comprised of hepatocytes, biliary epithelial cells and/or progenitor liver cells that were arranged as bile duct-like structures along nascent vascular sprouts. Electron microscopy revealed groups of cohesive hepatocytes and bile canaliculi with multiple microvilli and tight cellular junctions. Hepatocytes were further organized into tight clusters surrounded by complex stromal structures and reticulin fibers. Also, we observed higher levels of albumin mRNA expression when hepatocytes were co-cultured with endothelial cells. To evaluate viability and microsomal deethylation activity of hepatocytes we assessed the metabolism of midazolam by gas chromatography. Samples that were collected from HLC cultured in the bioreactor contained higher levels of midazolam metabolites (1-OH-midazolam and 4-OH-midazolam) than samples collected from conventional cultures. In summary, we have shown that co-culture of HLC with endothelial cells and/or culturing in the presence of PGA scaffolds provides additional advantages in maintaining functional activity of 3-D hepatocyte cultures that resemble liver tissue. This cell culture system may facilitate studies of liver regeneration and cell-to-cell interactions that occur in vivo and suggest the feasibility of using this approach for pre-clinical metabolic screening of novel drug candidates.

Pellis, Neal R.↗

NASA NTRS2013

Coordinated in Situ Analyses of Organic Nanoglobules in the Sutter's Mill Meteorite

The Sutter's Mill meteorite is a newly fallen carbonaceous chondrite that was collected and curated quickly after its fall. Preliminary petrographic and isotopic investigations suggest affinities to the CM2 carbonaceous chondrites. The primitive nature of this meteorite and its rapid recovery provide an opportunity to investigate primordial solar system organic matter in a unique new sample. Here we report in-situ analyses of organic nanoglobules in the Sutter's Mill meteorite using UV fluorescence imaging, Fourier-transform infrared spectroscopy (FTIR), scanning transmission electron microscopy (STEM), NanoSIMS, and ultrafast two-step laser mass spectrometry (ultra-L2MS).

Nakamura-Messenger, K.↗

NASA NTRS2017

The Chemistry of Pluto and its Satellites

Pluto's bulk composition and the composition of the surface layers hold clues to the origin and evolution of a number of other Solar System bodies of comparable size in the region beyond Neptune. The July 14, 2015 flyby of the Pluto system with the New Horizons spacecraft afforded the opportunity to corroborate and greatly improve discoveries about the planet and its satellites derived Earth-based studies. It also revealed extraordinary details of the surface and atmosphere of Pluto, as well as the geology and composition of Charon and two smaller satellites. With a mean density of 1.86 g/sq cm, the bulk composition of Pluto is about two-thirds anhydrous solar composition rocky material and one-third volatiles (primarily H2O in liquid and solid states) by mass, the surface is a veneer of ices dominated by N2, with smaller amounts of CH4 and CO, as well as limited exposures of H2O ice (considered to be "bedrock"). N2, CH4, and CO occur as solid solutions at temperature-dependent mutual concentrations, each component being soluble in the others. Frozen C2H6 as a minor component has also been identified. Sublimation and recondensation of N2, CH4, and CO over seasonal (248 y) and Milankovich-type megaseasons (approx. 3 My) result in the redistribution of these ices over time and with latitude control. Solid N2 is found in glaciers originating in higher elevations and flowing at the present time into a basin structure larger than the State of Texas, forming a convecting lens of N2 that overturns on a timescale of order 10 My. The varied colors of Pluto's landscape arise from the energetic processing of the surface ices in processes that break the simple molecules and reassemble complex organic structures consisting of groups of aromatic rings connected by aliphatic chains. When synthesized in the laboratory by UV or electron irradiation of a Pluto mix of ice, this material, called tholin, has colors closely similar to Pluto. The Pluto ice tholin analog contains carboxylic acids, urea, ketones, aldehydes, amines, and some nitriles. The largest satellite, Charon has density 1.70 g/sq cm and it is about 3/5 anhydrous solar composition rock, with the remainder in H2O ice. The surface H2O ice is infused in some way with NH3, probably as a hydrate, distributed nonuniformly, but to some degree related to geological structures. Pluto's atmosphere is N2, CH4, with CO, C2-hydrocarbons, HCN, and other molecules in trace but detectable amounts. The atmosphere supports a complex haze structure with about 20 discrete layers, and suspected clouds. The haze is presumed to be made of aggregates of complex hydrocarbons (tholins) produced by photolysis of the atmospheric gases, and with similar composition to the ice tholins made on the planet's surface. Urea and a suite of carboxylic acids are of interest for prebiotic and biological chemistries.

SOLAR SYSTEMS↗

NASA NTRS2023

Electronic Nose Development and Preliminary Human Breath Testing for Rapid, Non-Invasive COVID-19 Detection

We adapted an existing, spaceflight-proven, robust “electronic nose” (E-Nose) that uses an array of electrical resistivity-based nanosensors mimicking aspects of mammalian olfaction to conduct on-site, rapid screening for COVID-19 infection by measuring the pattern of sensor responses to volatile organic compounds (VOCs) in exhaled human breath. We built and tested multiple copies of a hand-held prototype E-Nose sensor system, composed of 64 chemically sensitive nanomaterial sensing elements tailored to COVID-19 VOC detection; data acquisition electronics; a smart tablet with software (App) for sensor control, data acquisition and display; and a sampling fixture to capture exhaled breath samples and deliver them to the sensor array inside the E-Nose. The sensing elements detect the combination of VOCs typical in breath at parts-per-billion (ppb) levels, with repeatability of 0.02% and reproducibility of 1.2%; the measurement electronics in the E-Nose provide measurement accuracy and signal-to-noise ratios comparable to benchtop instrumentation. Preliminary clinical testing at Stanford Medicine with 63 participants, their COVID-19-positive or COVID-19-negative status determined by concomitant RT-PCR, discriminated between these two categories of human breath with a 79% correct identification rate using “leave-one-out” training-and-analysis methods. Analyzing the E-Nose response in conjunction with body temperature and other non-invasive symptom screening using advanced machine learning methods, with a much larger database of responses from a wider swath of the population, is expected to provide more accurate on-the-spot answers. Additional clinical testing, design refinement, and a mass manufacturing approach are the main steps toward deploying this technology to rapidly screen for active infection in clinics and hospitals, public and commercial venues, or at home.

COVID-19↗

NASA NTRSDate not supplied

Spacecraft Cabin Ventilation Fan Research at NASA

NASA has recently made the geometry and solid model for a spacecraft cabin ventilation fan prototype available to the public via electronic file downloads from the NASA Technical Report Server. This fan can be used for research and development by many organizations. The fan is 3.5 inches in diameter, 9 inches long, and weighed 3.6 lb. The NASA Quiet Space Fan was designed to make 3.64 inches of water pressure rise at 150.3 cfm of airflow at 12,000 rpm at standard air conditions of 70ºF and 14.7 psia. The performance of the metal version of the fan was measured to be 3.48 inches of water at 150.6 cfm at design speed. A low-noise blade-vane count was chosen to try to reduce tone noise generated by this fan by cutting off the first three blade passing frequency tones. In-duct microphone array measurements indicated that the most evident tones occur for frequencies of 1800 Hz (1 BPF) and 7200 Hz (4 BPF). Using reverberant room standard testing methods, the A-weighted sound power level for the fan operating at design point conditions was measured to be 71 dBA. This report describes the current set of publicly available information for this fan. The fan was designed, optimized, and tested with tools and techniques that NASA has traditionally used for turbofan engine research. This is one way that technology developed for aerospace applications can be used more broadly, since quiet and efficient fans are needed for many ventilation systems on spacecraft, aircraft, watercraft, land vehicles, and buildings.

fan, noise, ventilation↗

NASA NTRSDate not supplied

Spacecraft Cabin Ventilation Fan Research at NASA

NASA has recently made the geometry and solid model for a spacecraft cabin ventilation fan prototype available to the public via electronic file downloads from the NASA Technical Reports Server. This fan can be used for research and development by many organizations. The NASA Quiet Space Fan is 8.89 cm (3.50 in) in diameter, 22.9 cm (9.00 in) long, and the metal fan weighs 1.63 kg (3.6 lbm). The fan was designed to generate a system total pressure rise of 906 Pa (3.64 inches of water) at 0.709 m3/s (150.3 cfm) of airflow at 12,000 rpm (at 21.1ºC (70ºF) and 14.7 psia). Performance measured using standardized techniques showed good agreement with design and predicted values. A low-noise blade-vane count was chosen to reduce tonal noise generated by rotor-stator interaction for the first three blade passing frequency harmonics. In-duct microphone array measurements indicated that the most evident tones occur at frequencies of 1,800 Hz (1 BPF) and 7,200 Hz (4 BPF). Using reverberant room standard testing methods, the A-weighted sound power level for the fan operating at design point conditions was measured to be 71 dBA. This report describes the current set of publicly available information for this fan. The fan was designed, optimized, and tested with tools and techniques that NASA has traditionally used for turbofan engine research. This demonstrates that technology developed for aerospace applications can be used more broadly, since quiet and efficient fans are needed for many ventilation systems in spacecraft, aircraft, watercraft, land vehicles, and buildings.

fan↗