Aura’s Two Decades of Enlightening our Understanding of Processes Impacting the Ozone Layer: Progress, Surprises, and Next Challenges
Aura’s two decades of enlightening our understanding of processes impacting the ozone layer.
Ozone Layer↗
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Results for “Understanding”
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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A Natural Language Understanding Approach for Digitizing Aircraft Ground Taxi Instructions
Advancements in natural language processing (NLP) technologies offer a unique opportunity to furnish aircraft crews, primarily pilots, with digital instructions for taxiing operations. Digital taxi instructions, delivered either as text or graphics, can streamline taxiing procedures, thereby reducing radio congestion, minimizing communication errors, and enhancing aircraft monitoring. Techniques used for natural language understanding (NLU), a subset of NLP focused on machine comprehension of natural language, can extract taxi instructions directly from verbal radio communications. This capability paves the way for implementing a digital taxi communication framework with minimal adjustments to the existing air traffic controller operations. This paper delves into a novel application of NLU: the automated generation of digital taxi instructions from air traffic controller speech. We detail the development of an annotation scheme to represent aircraft ground traffic communications within the US National Airspace System (NAS), employing intent classification (IC) and slot filling (SF) to extract taxi instructions using NLU models. Several neural network models were trained on a dataset annotated with our scheme, achieving notable accuracy and 𝐹1 scores. Our research demonstrates the feasibility of using NLU to automatically generate digital taxi instructions, showcasing its potential to streamline the implementation of digital taxi communications.
ATC↗
Understanding the Variability of Helium Abundance in the Solar Corona Using Three Fluid Modeling and Ultraviolet Observations
The variability of helium abundance in the solar corona and the solar wind is an important signature of solar activity, solar cycle, and solar wind sources, as well as coronal heating processes. Motivated by recently reported remote-sensing UV imaging observations by Helium Resonance Scattering in the Corona and Heliosphere payload sounding rocket of helium abundance in the inner corona on 2009 September 14 near solar minimum, we present the results of the first three-dimensional three-fluid (electrons, protons, and alpha particles) model of tilted coronal streamer belt and slow solar wind that illustrates the various processes leading to helium abundance differentiation and variability. We find good qualitative agreement between the three-fluid model and the coronal helium abundance variability deduced from UV observations of streamers, providing insight on the effects of the physical processes, such as heating, gravitational settling, and interspecies Coulomb friction in the outflowing solar wind that produce the observed features. The study impacts our understanding of the origins of the slow solar wind.
Leon Ofman↗
The SWOT Mission Will Reshape Our Understanding of the Global Terrestrial Water Cycle
Simultaneously integrating Surface Water and Ocean Topography (SWOT) measurements and those from other Earth observing satellites into hydrological modeling systems will transform our understanding of the global terrestrial water cycle. Such an opportunity comes with big challenges that the scientific community is now presented with.
Natural hazards↗
Informing Planetary Protection Policies for the Future Exploration of Ceres: State of Understanding after the Dawn Mission
We review the current state of understanding of Ceres as it relates to planetary protection policy for future landed missions, including for sample return, to the dwarf planet. The Dawn mission found Ceres to be an intriguing target for a mission, with evidence for the presence of regional, possibly extensive liquid at depth, and local expressions of recent and potentially ongoing activity. The Dawn mission also found a high abundance of carbon in the regolith, interpreted as a mix of carbonates and amorphous carbon, as well as locally high concentrations of organic matter. Key findings from this review are as follows: (1) outside of the region of Occator crater, Ceres shows no geological evidence for conduits from the surface to the interior; and (2) considering the biological potential of Ceres’ deep interior, a surface sample return mission should be considered Category V restricted, unless it can be demonstrated that evaporites sourced from Ceres’ deep brine region, and recently exposed in Occator crater, have not been scattered to the rest of Ceres’ surface; in that case, the probability of returning an unsterilized particle to an acceptably low value is to be determined by a future study. Key Words: Ceres—Planetary protection—Brines—Future missions.
Julie Castillo-Rogez↗
Understanding and Controlling Hybrid Electric Gas Turbine Engine Transient Dynamics
The electrification of the gas turbine engine is known to increase the flexibility of aircraft architectures by enabling the generation of electrical power to distribute to other electrically based, thrust producing subsystems. It also has potential for direct performance benefits in the gas turbine engine itself, both at steady state and dynamically. Although the design focus of the gas turbine engine performance is primarily at steady state, it is often the instabilities occurring during transients that cause disequilibrium and constrain performance improvements. Instabilities arise due to the disequilibrium of the energy storage mechanisms within the traditional engine system and likewise for the electrified engine system. The primary energy storage mechanisms in the traditional system are the rotational inertia, gas path volumes, the thermal masses that make up the mechanical structure, and now, the electrical power system will provide additional contributions. Understanding the effect each of these energy storage mechanisms has on the others and controlling them appropriately allows for the suppression of state changes within the turbomachinery components to the degree that the components remain near steady state, thus reducing the disequilibrium within the system. The ability to tightly regulate the state changes of turbomachinery components, such as the compressor, minimizes the excursion of the compressor operating point from the operating line (operability), allowing for higher performing, more efficient compressor designs by decreasing the amount of stall margin needed for safe engine power level changes. Preliminary studies with the electrification of the turbine engine have shown that this is possible, and this concept can lead to design trades benefitting engine performance, weight, and volume. This paper explores in detail the energy storage mechanisms and control approaches for coordinating their state changes, and ultimately proposes that a higher performing, more efficient compressor design can result.
transient dynamics↗
Turbomachinery Simulation Impact on Design, Understanding, and Optimization
This presentation shows the impact of Turbomachinery Simulation from simple analytical simulation to high fidelity CFD and Finite Element Analysis on the design of turbomachinery and the understanding of flow physics that is then used to improve design approaches. The impact of Optimization is also presented. The best approach for the tool development is to work with a compressor, fan, or turbine designer or to work on the design process directly. The presentation represents the work and impact of the author over his 45-year career and provides insight for both new and experienced engineers. The presentation explores applications of distortion from a downstream fan frame, the first uses of 3D CFD for fan, compressor and turbine design, and approaches to optimization for performance and structures.
optimization↗
Argonne News Brief: Here be Dragons! Komodo Dragons Help Understanding of Microbial Health
Researchers found that captive Komodo Dragons share microbes with their environment, just as humans and pets do within homes. These observations build our understanding of the impact of captivity on health, which could lead to improvements in the care of animals within our homes and other closed environments.
59 BASIC BIOLOGICAL SCIENCES↗
Storyline Visualization: A Compelling Way to Understand Patterns over Time and Space
Storyline visualization is a compelling way to understand patterns over time and space. Much effort has been spent developing efficient and aesthetically pleasing layout optimization algorithms. But what if those algorithms are optimizing the wrong things? To answer this question, we conducted a design study with different storyline layout algorithms. We found that users with our new design principles for storyline visualization outperform existing methods.
97 MATHEMATICS AND COMPUTING↗
Stereo-Optic High Definition Imaging: A New Technology to Understand Bird and Bat Avoidance of Wind Turbines
There is a critical need to develop monitoring tools to track aerofauna (birds and bats) in three dimensions around wind turbines. New monitoring systems will reduce permitting uncertainty by increasing the understanding of how birds and bats are interacting with wind turbines, which will improve the accuracy of impact predictions. Biodiversity Research Institute (BRI), The University of Maine Orono School of Computing and Information Science (UMaine SCIS), HiDef Aerial Surveying Limited (HiDef), and SunEdison, Inc. (formerly First Wind) responded to this need by using stereo-optic cameras with near-infrared (nIR) technology to investigate new methods for documenting aerofauna behavior around wind turbines. The stereo-optic camera system used two synchronized high-definition video cameras with fisheye lenses and processing software that detected moving objects, which could be identified in post-processing. The stereo- optic imaging system offered the ability to extract 3-D position information from pairs of images captured from different viewpoints. Fisheye lenses allowed for a greater field of view, but required more complex image rectification to contend with fisheye distortion. The ability to obtain 3-D positions provided crucial data on the trajectory (speed and direction) of a target, which, when the technology is fully developed, will provide data on how animals are responding to and interacting with wind turbines. This project was focused on testing the performance of the camera system, improving video review processing time, advancing the 3-D tracking technology, and moving the system from Technology Readiness Level 4 to 5. To achieve these objectives, we determined the size and distance at which aerofauna (particularly eagles) could be detected and identified, created efficient data management systems, improved the video post-processing viewer, and attempted refinement of 3-D modeling with respect to fisheye lenses. The 29-megapixel camera system successfully captured 16,173 five-minute video segments in the field. During nighttime field trials using nIR, we found that bat-sized objects could not be detected more than 60 m from the camera system. This led to a decision to focus research efforts exclusively on daytime monitoring and to redirect resources towards improving the video post- processing viewer. We redesigned the bird event post-processing viewer, which substantially decreased the review time necessary to detect and identify flying objects. During daytime field trials, we determine that eagles could be detected up to 500 m away using the fisheye wide-angle lenses, and eagle-sized targets could be identified to species within 350 m of the camera system. We used distance sampling survey methods to describe the probability of detecting and identifying eagles and other aerofauna as a function of distance from the system. The previously developed 3-D algorithm for object isolation and tracking was tested, but the image rectification (flattening) required to obtain accurate distance measurements with fish-eye lenses was determined to be insufficient for distant eagles. We used MATLAB and OpenCV to improve fisheye lens rectification towards the center of the image, but accurate measurements towards the image corners could not be achieved. We believe that changing the fisheye lens to rectilinear lens would greatly improve position estimation, but doing so would result in a decrease in viewing angle and depth of field. Finally, we generated simplified shape profiles of birds to look for similarities between unknown animals and known species. With further development, this method could provide a mechanism for filtering large numbers of shapes to reduce data storage and processing. These advancements further refined the camera system and brought this new technology closer to market. Once commercialized, the stereo-optic camera system technology could be used to: a) research how different species interact with wind turbines in order to refine collision risk models and inform mitigation solutions; and b) monitor aerofauna interactions with terrestrial and offshore wind farms replacing costly human observers and allowing for long-term monitoring in the offshore environment. The camera system will provide developers and regulators with data on the risk that wind turbines present to aerofauna, which will reduce uncertainty in the environmental permitting process.
Adams, Evan↗
Understanding Composition, Formation, and Aging of Organic Aerosols in Wildfire Emissions via Combined Mountain Top and Airborne Measurements
Wildfires are an important source of global aerosols that have pronounced impacts on regional air quality and global climate. A major component of wildfire emissions is organic, including primary organic aerosols (POA) and large amounts of gases that can be oxidized to form secondary organic aerosols (SOA). The environmental impacts of wildfire emissions are strongly correlated with the chemical, optical, and microphysical properties of biomass-burning organic aerosols (BBOA), which are dependent, in a complex manner, on combustion and atmospheric aging processes. Here we discuss results from recent field and laboratory studies aimed at understanding the chemical composition, formation, and evolution of BBOA in wildfire emissions. Comprehensive analysis of a large number of fresh and aged (up to days of aging) fire plumes originating in the Pacific Northwest region of the United States reveals that the enhancement of BBOA mass concentrations relative to the enhancement of the sum of CO and CO2 in wildfire smokes is primarily driven by combustion efficiency, whereas the composition and properties of the BBOA are strongly influenced by atmospheric oxidation and other aging processes. These results shed light on organic aerosol formation and transformation in biomass burning emissions.
54 ENVIRONMENTAL SCIENCES↗
Understanding Infrastructure Dependency During Natural Hazards Events for Actionable Disaster Responses
One major focus of the Sendai Framework for Disaster Risk Reduction 2015-2030 is to “Build Back Better” in recovery, rehabilitation and reconstruction to achieve disaster risk reduction and resilient communities. While forecasting and decision-making tools help predict and understand future impacts of natural hazards, given the interdependency of infrastructures, predictive approaches fail to identify long-term impacts of an extreme event on infrastructures and recovery time. As seen following hurricane Maria’s impacts in Puerto Rico, the failure of power infrastructure not only isolated the island from the outside world, but also contributed to the lack of supply of clean and filtered water, and sewage treatment. While there have been several decision support tools that look at the vulnerability and resilience of different critical infrastructure systems as a single system and/or coupled systems, there still exists a gap in quantifying system vulnerabilities due to cascading impacts. In this paper, we present a conceptual framework for quantifying dynamic resilience of interdependent infrastructure systems. The proposed approach should provide the knowledge needed for stakeholders and decision-makers to prioritize their efforts during recovery to build resiliency.
Omitaomu, Femi↗
A Dual-Lattice Discrete Element Model to Understand Hydraulic Fracturing in a Naturally Fractured System
Interaction between hydraulic fractures (HF) and natural fractures (NF) may lead to complex fracture networks as a consequence of branching and merging of the natural and hydraulically-induced/reopened fractures. Conventional simulation methods, with assumptions of homogeneous and continuous media, are not able to capture realistic fracture patterns in the presence of pre-existing natural fractures (open or healed). These natural discontinuities alter the local stress field and impact the fracturing fluid pressure distribution when hydraulically-driven fractures approach natural discontinuities. Modeling the propagation of one or more propagating hydraulic fractures in naturally fractured reservoirs should carefully consider the complex mechanical and hydraulic interactions between hydraulically-driven and natural fractures. A rigorous hydraulic fracturing model based on a coupled discrete element method (DEM) and conjugate network flow model is described in this work. The coupled DEM-network flow model conveniently accounts for both continuous poroelasticity and discrete natural fractures simultaneously and provides more realistic fracture growth patterns in low-permeability rocks. This dual lattice DEM-network flow model can capture both tension-induced rock failure and shear-induced natural discontinuity sliding and dilation. Simulation results revealed that reactivation of natural fractures becomes more difficult when the following conditions are present: larger magnitude of stress difference, higher intercepting angle between the natural fracture and the propagating hydraulic fracture (higher implies more orthogonal to the natural fracture), larger natural fracture cohesion and angle of internal friction and/or lower natural fracture permeability - leading to continued growth of the hydraulic fracture. The term stress difference was colloquially used in the preceding sentence. For clarity, we will define this as ΔS = S H,max – S h,min ). The quantitative results of numerous simulations reinforced the intuitive understanding of the underlying phenomena. Other simulations reinforced insights from laboratory experimentation and field measurements that lower injection rates and treating fluid viscosities facilitate preferential fluid intake into natural fractures. Finally, this simulation capability for predicting the nature of complex fracture networks potentially enables optimizing treatment design and completion strategy in naturally fractured reservoirs.
42 ENGINEERING↗
Utilizing M3D-C1 to understand triggering of ELMs in DIII-D pellet pacing experiments
M3D-C1, a code for solving the linear and non-linear extended-MHD equations in toroidal geometry, is used to model pellet ELM triggering in DIII-D ITER-like plasmas. Understanding of the physical mechanisms of ELM triggering and improved modeling are required for condent extrapolation to ITER and beyond. M3D-C1 results run in linear 2D mode show that the localized perturbation is due to the pellet destabilizing peeling-ballooning modes. Calculations of linear peeling-ballooning stability as a function of pellet size suggest that a 2D pellet density ring underestimates the eects of the pellet.
Diem, Stephanie↗
Argonne broadens understanding of America’s transportation and mobility systems
Mobility in America is changing fast. To understand where it’s headed, Argonne caught up with Michael Berube, the acting deputy assistant secretary for transportation in the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy. While at the laboratory, Berube took time to highlight the ways in which technology and consumer demand are shaping transportation, and the insights national laboratories like Argonne can provide about the future.
97 MATHEMATICS AND COMPUTING↗
Toward Greater Understanding of Upstream and Downstream Manufacturing Processes for Automotive of Li-Ion Batteries
This work focuses on cost associated with extraction and purification of raw materials used in Li-ion batteries such as Co, Ni, Mn and graphite. This work also attempts to expand cost analysis to cover costs associated with cells and modules packaging. Value chain analysis will be used to facilitate understanding of costs in the manufacturing processes of Li-ion batteries.
25 ENERGY STORAGE↗
Developing Publicly Available LCA Guidance, Data, and Tools for Environmental Understanding of Emerging CO2 Utilization Research - LCAXIX
This work was presented at the American Center for Life Cycle Assessment 2019 Conference (LCAXIX) in Tucson, AZ on September 25, 2019. Capturing carbon dioxide (CO2) emissions from power and industrial sources and using that CO2 to make useful products is an emerging area of research that will benefit from a consistent and unbiassed framework like life cycle assessment/analysis (LCA) to understand the environmental impacts and net life cycle GHG reductions compared to the current state of the alternative in the marketplace. In the interest of supporting the creation of useful and consistent LCAs of CO2 utilization projects, the DOE National Energy Technology Laboratory has developed a CO2 utilization LCA toolkit. The primary audience for the toolkit is the group of principal investigators that have been awarded a grant through a DOE Carbon Use and Reuse funding opportunity announcement. However, we believe that there is potential wider application beyond those grant recipients.
Cooney, Gregory↗
Understanding Occupancy Patterns in a Commercial Space
Heating, ventilation, and air conditioning (HVAC) is a prime source of energy consumption in the US. In 2006, approximately 35% of energy in the US was used for HVAC [1]. Usually building operators use a static schedule for controlling HVAC systems without having a deeper understanding of how many people use the building at different times of the day. In addition, HVAC systems operate by assuming maximum occupancy in each room, which leads to a significant energy waste, e.g., an HVAC system providing ventilation for 30 people when there are only 10 people in a room. Considering how many people use different rooms at different times of the day is very crucial for achieving building energy efficiency and providing occupant comfort. There have been several attempts to collect long term occupancy patterns from office buildings, e.g., Mitsubishi’s Electronic Research Lab (MERL) dataset [14] and Colorado School of Mines (CSMBB) dataset. However, PIR motion detectors are used in these projects for sensing occupancy and hence these datasets only reflect whether a room is occupied or not without revealing the actual person count. Similar datasets are also collected from households. Only a few datasets from commercial spaces capture actual person count, and even in these cases, the data collection period was very limited, e.g., in [3] only 5 days of occupancy data is collected as ground truth. We are the first to collect long term (9 months) occupancy data (people count) from an 11,000 square foot commercial office (second floor of Bosch Research and Technology Center Pittsburgh). In this paper, we outline some statistical results from our empirical study and explore their implications for saving energy.
42 ENGINEERING↗