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DOE OSTI2026

Fault Slip and Fluid Flow: Seismic Source Analysis to Assess Role of Multiple Slip Patches in Fault Permeability

The relationship between fault reactivation, microearthquakes (MEQs), and permeability evolution during fluid injection plays a critical role in energy harvesting and waste disposal. Recent studies have demonstrated the possibility of predicting fault permeability using cumulative seismic moments of MEQs quantitatively. To understand the underlying physical processes, we conduct fault reactivation experiments using Utah FORGE granitoid and analyze acoustic emission (AE) signals generated during stepwise increases in fluid injection pressure. Frequency analysis of thousands of calibrated AE signals reveals that fault reactivation produces multiple AE source patches with millimeter-scale radii—smaller than the sample fault radius. The cumulative area of the reactivated patches covers the fault multiple times over (∼10x–50x area) for each pressure step. These findings provide mechanistic insight that measured permeability enhancement is not driven by a single large slip event, but by the sequential and interacting activation of multiple slip patches that create a continuous flow pathway.

Nurshal, M. E. M. [Pennsylvania State University, ↗

DOE OSTI2024

Self-assembled reconfigurable pump architectures via magnetic colloidal swarms

Self-assembled swarms of interactive active units, which are adaptive and dynamically reconfigurable to accommodate different functionalities, represent a promising platform for the development of next-generation robotics. Here, we utilize the emergent collective behavior of active magnetic colloids confined in quasi-two-dimensional arrays of overlapping wells to demonstrate the self-organization of a colloidal swarm into a dynamic pump architecture capable of controlled transport of passive cargo particles. This dynamic architecture provides a global unidirectional looping flow pattern along the entire length of the system. We show that the flow direction of the dynamic swarm-based pump can be externally controlled by a phase shift of a driving magnetic field energizing the swarm. The experimental observations are supported by computational modeling based on phenomenological coarse-grained particle dynamics coupled to shallow-water Navier-Stokes hydrodynamics. In conclusion, our findings demonstrate how the emergent collective behavior of a swarm can be orchestrated into a desired functionality by exploiting the interplay between activity and confinement potentials.

36 MATERIALS SCIENCE↗

DOE OSTI2023

Origin of surface and subband states at the InAs(111)A surface

The atomic structure of surfaces and interfaces plays a vital role in the electronic quality and properties of quantum devices. The interplay between the surface and confined bulk subband states in terms of their susceptibility has been investigated in relation to crystal defects on an InAs(111)A-(2×2) reconstructed surface, using low-temperature scanning tunneling microscopy and spectroscopy. We measure the two-dimensional quantized subband states arising from the confined potential imposed by downward bending of the conduction band edge. Furthermore, we show evidence of the existence of surface Bloch states within the confined bulk band gap projected on the surface spectrum which have originated from the surface reconstruction. As expected, larger confined bulk band gaps at the surface and conduction band offset are measured to be 0.58 and 0.31 eV, respectively. Here we further show the scattering of these quantum states at different surface defects and demonstrate that surface states are more susceptible to the defect potential when compared with the corresponding subband states. This apparent contrast follows from the length scale at which these defect potentials actively interact on or near the surface. Our observed experimental results are supported by empirical tight-binding simulations for the subband states and first-principles density functional theory simulations for the surface states present on the surface.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

DOE OSTI2024

JISEA-CSU Sustainable Agriculture Workshop [Slides]

The JISEA-CSU Sustainable Agriculture Workshop was co-hosted by the National Renewable Energy Laboratory's Joint Institute for Strategic Energy Analysis Sustainable Agriculture Catalyzer and the Colorado State University Ag Innovation Center, and sponsored by the Colorado-Wyoming Climate Resilience Engine. The workshop brought together researchers, agricultural producers, technology innovators, investors, and policymakers to examine the past, present, and future of the U.S. agriculture and energy strategy. The workshop will feature presentations, panels, and interactive activities that dive into the successes and challenges of the industry to help inform the direction of future research efforts.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

DOE OSTI2025

SBND Calibration

The Short-Baseline Near Detector (SBND) is a 112-ton liquid argon time projection chamber (LArTPC) serving as the near detector of the Short-Baseline Neutrino Program at Fermilab. SBND aims to make precise measurements of neutrino-argon interactions, necessitating an extensive calibration program for the LArTPC to ensure precision/accuracy in these measurements. This talk describes the use of cosmogenic, radiogenic, and neutrino interaction activity with both Monte Carlo simulation and data in calibrating the SBND subsystems of the Time Projection Chamber, Photon Detection System, and Cosmic Ray Tagger. We will highlight some of SBND's first calibration results, including electronics calibrations, measurement of the electron lifetime, shower calibration, and studies of space charge effects in the detector.

Oh, Sungbin [Fermilab]↗

NASA NTRS1978

NASA metrication activities

NASA's organization and policy for metrification, history from 1964, NASA participation in Federal agency activities, interaction with nongovernmental metrication organizations, and the proposed metrication assessment study are reviewed.

Vlannes, P. N.↗

NASA NTRS1986

Protobiological informatoin, bidirectional recognition and reverse translation

Emergence of protobiological information has been suggested by experiments in which heated mixtures of alpha-amino acids order themselves into a self limited array of thermal proteins. The polymers display selective catalytic, hormonal, and other activities. Interactions of varied cationic thermal proteins with polynucleotides indicate selective recognition in both directions. Reverse translation is partly a missing link in the molecular evolution flowsheet. The self ordering of amino acids serves conceptually as a deterministic evolutionary precursor of the modern coding mechanism. The possibility for the evolution of information at an early nontemplated protein stage is supported by findings of electrical signals from proteinoid microspheres prepared with no DNA/RNA in their history. The deposition of thermal copolyamino acids on lipid membranes in the Mueller-Rudin apparatus has here been found to produce electrical behavior like that evoked by bacterial EIM polypeptide. A new procedure is to make a film of membrane on the electrode; the results provide maximal repeatability. The principle of nonrandom biomacromolecular specificity identified by these studies in molecular evolution have been extrapolated to principles of evolution of advanced organisms.

Fox, S. W.↗

NASA NTRS1987

The spectral characteristics of rotor blade-vortex interaction noise - Experimental and mathematical results

The BVI impulsive content of a rotor acoustic signal is shown to appear in the mid-frequency range of the power spectrum, between the fifth and thirtieth harmonics of the blade passage frequency, concentrated at the harmonics of the blade passage frequency. These harmonics exhibit a humped or scalloped shape in this mid-frequency spectral region. Increased energy at the harmonics of the shaft frequency appears when the BVI impulsive content demonstrates unsteadiness and blade-to-blade differences in the time domain. A mathematical model of a generalized BVI acoustic signal and its power spectrum shows that the power spectrum is scalloped and filtered by a comb function. The spectrum amplitude is defined by the impulse amplitude and emission time. The scalloping of the spectrum is related to the emission time of the impulse itself, and the spacing of the comb function is related to the repetition time (period) of the impulse. The decay rate of the spectral humps is governed by the inverse of frequency squared. The mathematical model validates the characteristics observed in the data and verify that these characteristics are due to blade-vortex interaction activity.

Martin, Ruth M.↗

NASA NTRS1985

KARL: A Knowledge-Assisted Retrieval Language

Data classification and storage are tasks typically performed by application specialists. In contrast, information users are primarily non-computer specialists who use information in their decision-making and other activities. Interaction efficiency between such users and the computer is often reduced by machine requirements and resulting user reluctance to use the system. This thesis examines the problems associated with information retrieval for non-computer specialist users, and proposes a method for communicating in restricted English that uses knowledge of the entities involved, relationships between entities, and basic English language syntax and semantics to translate the user requests into formal queries. The proposed method includes an intelligent dictionary, syntax and semantic verifiers, and a formal query generator. In addition, the proposed system has a learning capability that can improve portability and performance. With the increasing demand for efficient human-machine communication, the significance of this thesis becomes apparent. As human resources become more valuable, software systems that will assist in improving the human-machine interface will be needed and research addressing new solutions will be of utmost importance. This thesis presents an initial design and implementation as a foundation for further research and development into the emerging field of natural language database query systems.

Dominick, Wayne D.↗

NASA NTRS1990

Influence of penetrating solar radiation on the heat budget of the equatorial Pacific Ocean

Recent satellite observations of ocean transparency, coupled with climatological surface heat fluxes and ocean density profiles, are used here to show that solar radiation in visible frequencies, usually assumed to be absorbed at the sea surface, in fact penetrates to a significant degree to below the upper mixed layer of the ocean which interacts actively with the atmosphere. The net effect is a reduction of the heat input into the upper layer; for a 20 m-thick mixed layer this is equivalent to an annual reduction in temperature of about 5-10 K. The results provide a natural explanation for the discrepancy between the SSTs predicted by models and those observed.

Lewis, Marlon R.↗

NASA NTRS1992

A near-infrared imaging survey of interacting galaxies - The small angular-size Arp systems

Near-IR images of a large sample of interacting galaxies selected from the Atlas of Peculiar Galaxies by Arp (1966) have been obtained. Approximately 180 systems have been imaged in at least two, and usually three of the standard JHK bands. The survey and the observing and data reduction procedures, are described, and contour plots and aperture photometry are presented. Future papers will analyze the imaging data by groupings based on interaction type, stage, and progenitors. The goals of the analysis are to explore the relationships between galaxy interactions, activity, and morphology by studying the structure of the near-IR luminosity distribution, where extinction effects are much reduced relative to the optical and the major stellar mass component of galaxies dominates the observed light.

Bushouse, Howard A.↗

NASA NTRS1992

Spatial orientation, adaptation, and motion sickness in real and virtual environments

Reason and Brand (1975) noted that motion sickness occurs in many situations involving either passive body motion or active interaction with the world via indirect sensorimotor interfaces (e.g., prism spectacles). As might be expected, motion sickness is being reported in VEs that involve apparent self-motion through space, the best known examples being flight simulators (Kennedy et al., 1990). The goals of this paper are to introduce the motion-sickness symptomatology; to outline some concepts that are central to theories of motion sickness, spatial orientation, and adaptation; and to discuss the implications of some trends in VE research and development.

Dizio, Paul↗

NASA NTRS1994

Interferometric investigations of compressible dynamic stall over a transiently pitching airfoil

The compressible dynamic stall flowfield over a NACA 0012 airfoil transiently pitching from 0 to 60 deg at a constant rate under compressible flow conditions has been studied using real-time interferometry. A quantitative description of the overall flowfield, including the finer details of dynamic stall vortex formation, growth, and the concomitant changes in the airfoil pressure distribution, has been provided by analyzing the interferograms. For Mach numbers above 0.4, small multiple shocks appear near the leading edge and are present through the initial stages of dynamic stall. Dynamic stall was found to occur coincidentally with the bursting of the separation bubble over the airfoil. Compressibility was found to confine the dynamic stall vortical structure closer to the airfoil surface. The measurements show that the peak suction pressure coefficient drops with increasing freestream Mach number, and also it lags the steady flow values at any given angle of attack. As the dynamic stall vortex is shed, an anti-clockwise vortex is induced near the trailing edge, which actively interacts with the post-stall flow.

Chandrasekhara, M. S.↗

NASA NTRS1998

The Mars Gravity Simulation Project

Human beings who make abrupt transitions between one gravitational environment and another undergo severe disruptions of their visual perception and visual- motor coordination, frequently accompanied by "space sickness." Clearly, such immediate effects of exposure to a novel gravitational condition have significant implications for human performance. For example, when astronauts first arrive in Earth orbit their attempts to move about in the spacecraft and to perform their duties are uncoordinated, inaccurate, and inefficient. Other inter-gravitational transitions for which these difficulties can be expected include going from the 0 g of the spacecraft to the. 16 g of the Moon, from 0 g to the .38 g of Mars, and from 0 g back to the 1.0 g of Earth. However, after astronauts have actively interacted with their new gravitational environment for several days, these problems tend to disappear, evidence that some sort of adaptive process has taken place. It would be advantageous, therefore, if there were some way to minimize or perhaps even to eliminate this potentially hazardous adaptive transition period by allowing astronauts to adapt to the altered gravitational conditions before actually entering them. Simultaneous adaptations to both the altered and the normal gravitational environment as a result of repeatedly adapting to one and readapting to the other, a phenomenon known as dual adaptation. The objective of the Mars Gravity Simulator (MGS) Project is to construct a simulation of the visual and bodily effects of altered gravity. This perceptual-motor simulation is created through the use of: 1) differential body pressure to produce simulated hypo-gravity and 2) treadmill-controlled virtual reality to create a corresponding visual effect. It is expected that this combination will produce sensory motor perturbations in the subjects. Both the immediate and adaptive behavioral (postural and ambulatory) responses to these sensory perturbations will be assessed.

Korienek, Gene↗

NASA NTRS1998

HEDS-UP Mars Exploration Forum

In the early 1990s, Duke and Budden convened a series of workshops addressing mission rationale, exploration objectives, and key constraints and issues facing human crews on Mars. The focal point was "why" the U.S. should fly humans to Mars. In the mid-1990s, strategies for a Mars mission matured and evolved, driven formally by NASA Johnson Space Center's Office of Exploration. In 1997, NASA published a report capturing the current thinking: the NASA Mars Reference Mission. In the 1997-1998 school year, HEDS-UP sponsored six universities to conduct design studies on Mars exploration, using the Reference Mission as a basis for their work. The 1998 Mars Exploration Forum presents the results of these university studies, suggesting "how" we might explore Mars, in terms of specific technical components that would enable human missions to Mars. A primary objective of the HEDS-UP Mars Exploration Forum was to provide a forum for active interaction among NASA, industry, and the university community on the subject of human missions to Mars. NASA scientists and engineers were asked to present the state of exploration for Mars mission options currently under study. This status "snapshot" of current Mars strategies set the stage for the six HEDS-UP universities to present their final design study results. Finally, a panel of industry experts discussed readiness for human missions to Mars as it pertains to the aerospace industries and technologies. A robust poster session provided the backdrop for government-industry-university discussions and allowed for feedback to NASA on the Mars Reference Mission. The common thread woven through the two days was discussion of technologies, proven and emerging, that will be required to launch, land, and sustain human crews on the Red Planet. As this decade (and indeed this millenium) draws to a close, Mars will continue to loom in our sights as the next target for human space exploration. It is our hope that the efforts of the Mars Exploration Forum will serve as one small contribution toward the ultimate goal of humans exploring Mars.

Budden, Nancy Ann↗

NASA NTRS2003

Imagine the Universe!

Welcome to the 2004 edition of the education CD from the Laboratory for High Energy Astrophysics at NASA Goddard Space Flight Center. We hope that you will find it to be an exciting and fun learning experience. We have tried very hard to make this CD as user-friendly as possible and along the way we have discovered some things that every user may need to know. Please read the README file found on the CD if you have any questions or problems using the disk. Then, after that, if you still have problems, email us at itu@athena.gsfc.nasa.gov. We will be happy to help you 'get going'! Below are links to all of the sites included on the CD. You will also find the addresses for the on-line version of each of these sites. If you have a good Internet connection available, we recommend that you view the sites on-line. There you will find the latest updated information, interactive activities, and active links to other sites. Included on the disk are: Imagine The Universe! This site is dedicated to a discussion about our Universe... what we know about it, how it is evolving, and the kinds of objects and phenomena it contains. Emphasizing the X-ray and gamma-ray parts of the electromagnetic spectrum, it also discusses how scientists know what they know, what mysteries remain, and how the answers to remaining mysteries may one day be found. Lots of movies, quizzes, and a special section for educators. Geared for ages 14 and up. This site can be viewed on-line at http://imagine.gsfc.nasa.gov/. StarChild: A learning center for young astronomers The 1998 Webby Award Winner for Best Education Website, StarChild is aimed at ages 4-14. It contains easy-to-understand information about our Solar System, the Universe, and space exploration. There are also activities, songs, movies, and puzzles! This site can be viewed on-line at http://starchild.gsfc.nasa.gov/. Astronomy Picture of the Day APOD offers a new astronomical image and caption each calendar day. We have captured the year 2003 entries of this award-winning site and included them on the disk. The images and information provide a wonderful resource for all ages. This site can be viewed on-line at http://apod.gsfc.nasa.gov/apod/astropix.html.

White, N.↗

NASA NTRS1995

Observations of chemical processing in the circumstellar environment

High resolution interferometer and single-dish observations of young, deeply embedded stellar systems reveal a complex chemistry in the circumstellar environments of low to intermediate mass stars. Depletions of gas-phase molecules, grain mantle evaporation, and shock interactions actively drive chemical processes in different regions around young stars. We present results for two systems, IRAS 05338-0624 and NCG 1333 IRAS 4, to illustrate the behavior found and to examine the physical processes at work.

NASA Program Exobiology↗

NASA NTRS2010

Layered Model for Radiation-Induced Chemical Evolution of Icy Surface Composition on Kuiper Belt and Oort Cloud Bodies

The diversity of albedos and surface colors on observed Kuiper Belt and Inner Oort Cloud objects remains to be explained in terms of competition between primordial intrinsic versus exogenic drivers of surface and near-surface evolution. Earlier models have attempted without success to attribute this diversity to the relations between surface radiolysis from cosmic ray irradiation and gardening by meteoritic impacts. A more flexible approach considers the different depth-dependent radiation profiles produced by low-energy plasma, suprathermal, and maximally penetrating charged particles of the heliospheric and local interstellar radiation environments. Generally red objects of the dynamically cold (low inclination, circular orbit) Classical Kuiper Belt might be accounted for from erosive effects of plasma ions and reddening effects of high energy cosmic ray ions, while suprathermal keV-MeV ions could alternatively produce more color neutral surfaces. The deepest layer of more pristine ice can be brought to the surface from meter to kilometer depths by larger impact events and potentially by cryovolcanic activity. The bright surfaces of some larger objects, e.g. Eris, suggest ongoing resurfacing activity. Interactions of surface irradiation, resultant chemical oxidation, and near-surface cryogenic fluid reservoirs have been proposed to account for Enceladus cryovolcanism and may have further applications to other icy irradiated bodies. The diversity of causative processes must be understood to account for observationally apparent diversities of the object surfaces.

Cooper, John F.↗