Search NASA⌕ Search

SEARCH · Search NASA

Results for “sustainable manner”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 109 records · Page 6

Design and experimental demonstration of feedback adaptive RMP ELM controller toward complete long pulse ELM suppression on KSTAR

Operation of a fusion power plant requires robust edge localized mode (ELM) suppression simultaneously with high plasma performance. In this study, we describe a novel feedback adaptive resonant magnetic perturbation (RMP) ELM controller designed to address this problem by achieving optimized ELM suppression through the advanced application of 3D RMPs. From real-time $D_α$ data, the controller is achievable robust ELM suppression while simultaneously minimizing the applied RMP in order to enhance plasma performance. In real time, the instantaneous ELM-frequency is analyzed with an adaptive feedback algorithm to determine amplitudes and phases of RMP coil currents that will maximize plasma performance while maintaining ELM suppression. When applied through the KSTAR plasma control system in several experiments using $textiti{n}$ = 1 RMPs, robust ELM suppression is achieved and sustained in feedback while reducing the RMP strength to ~65% of its initial value. Minimization of the RMP strength in this manner not only allows for operation of longer discharges due to a decrease in flux consumption but also allows for a strong recovery of up to ~60% of $β_N$ throughout the ELM-free period.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

Increasing CO2 Conversion Efficiency with Optical Thermal Management in Concentrated Solar Reactors: New Dual-Stage Solar Reactor Design for Reduction of CO2 to Fuels

The proposed project will result in a new dual-stage solar chemical reactor designed to convert carbon dioxide (CO2) to value-added chemicals. Using sunlight as the main power source, a sustainable process will be developed that closes the loop on our industrial carbon cycle in an energy efficient and environmentally friendly manner. The hybrid photochemical and photothermal reactor design will vastly increase utilization of the solar spectrum and increase CO2 conversion efficiencies over Dimensional Energy’s current state-of-the-art.

10 SYNTHETIC FUELS↗

High Resolution Ion Energy Distribution Measurements for Energization Studies on Madison Symmetric Torus RFP Plasmas

We propose to continue a comprehensive and aggressive collaborative study of the critical issues of RFP and fusion physics at MST by enhancing the inferred ion distribution function and the high (spatial and temporal) resolution of magnetic fluctuation measurements. For this, we propose to make novel use of a retarding potential before a neutral particle analyzer as well as a novel millimeter magnetic probe. The measurement of relationships between ion and electron temperatures and magnetic field fluctuations can provide otherwise unobtainable insights on the role of turbulence in fusion plasmas with special focus on the impact of magnetic field turbulence on plasma confinement and scaling. These insights can be particularly valuable when they are coupled with an increased understanding of the issues which drive the turbulence onset, enhance steady-state sustainment, and enable turbulent dissipation. With these new insights, MST will be particularly well positioned to provide important insights in a manner portable to a broad class of fusion devices. We propose to exploit this opportunity and, at the same time, take full advantage of the associated educational enhancements for plasma physics students as FAMU continues to expand the diversity of the fusion scientific workforce.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

Engineering custom morpho- and chemotypes of Populus for sustainable production of biofuels, bioproducts, and biomaterials

Humans have been modifying plant traits for thousands of years, first through selection (i.e., domestication) then modern breeding, and in the last 30 years, through biotechnology. These modifications have resulted in increased yield, more efficient agronomic practices, and enhanced quality traits. Precision knowledge of gene regulation and function through high-resolution single-cell omics technologies, coupled with the ability to engineer plant genomes at the DNA sequence, chromatin accessibility, and gene expression levels, can enable engineering of complex and complementary traits at the biosystem level. Populus spp., the primary genetic model system for woody perennials, are among the fastest growing trees in temperate zones and are important for both carbon sequestration and global carbon cycling. Ample genomic and transcriptomic resources for poplar are available including emerging single-cell omics datasets. To expand use of poplar outside of valorization of woody biomass, chassis with novel morphotypes in which stem branching and tree height are modified can be fabricated thereby leading to trees with altered leaf to wood ratios. These morphotypes can then be engineered into customized chemotypes that produce high value biofuels, bioproducts, and biomaterials not only in specific organs but also in a cell-type-specific manner. For example, the recent discovery of triterpene production in poplar leaf trichomes can be exploited using cell-type specific regulatory sequences to synthesize high value terpenes such as the jet fuel precursor bisabolene specifically in the trichomes. By spatially and temporally controlling expression, not only can pools of abundant precursors be exploited but engineered molecules can be sequestered in discrete cell structures in the leaf. The structural diversity of the hemicellulose xylan is a barrier to fully utilizing lignocellulose in biomaterial production and by leveraging cell-type-specific omics data, cell wall composition can be modified in a tailored and targeted specific manner to generate poplar wood with novel chemical features that are amenable for processing or advanced manufacturing. Precision engineering poplar as a multi-purpose sustainable feedstock highlights how genome engineering can be used to re-imagine a crop species.

09 BIOMASS FUELS↗

Theoretical investigation of surface chemical reactivity of compositionally disordered multi-metallic alloys

Alloys are widely used in both academic and industrial research as heterogeneous catalysts for accelerating technologically important reactions ranging from hydrocarbon reforming, selective hydrogenation, to electrochemical reactions involving hydrogen and oxygen that are fundamental and indispensable to a sustainable future energy infrastructure. Most basic catalysis research has been limited to combinations of two elements that are usually ordered in some manner at the nanoscale because doing so allows observable results to be easily rationalized. It however leaves a huge material space consisting of multi metallic, compositionally disordered alloys unexplored. This research demonstrates a viable theoretical approach combining different types of first principles calculations (including Green’s function-based Korringa–Kohn–Rostoker coherent potential approximation (KKR–CPA) and planewave-based density functional theory) to enable the surface chemical reactivity of compositionally complex alloy surfaces to be investigated. We demonstrate the approach by investigating hydrogen adsorption and evolution on two types of compositionally disordered alloys: a quaternary CoCrFeNi high-entropy alloy, and binary Pt-3d base metal alloys.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Resolution Study of Thermonuclear Initiation in White Dwarf Tidal Disruption Events

Abstract We study the initiation of thermonuclear detonations in tidally disrupted white dwarf stars by intermediate-mass (10 3 M ⊙ ) black holes. The length scales required to resolve the initiation mechanism are not easily reached in 3D, so instead we have devised 2D proxy models, which, together with a logarithmic gridding strategy, can adequately capture detonation wave fronts as material undergoes simultaneous compression and stretching from tidal forces. We consider 0.15 and 0.6 M ⊙ white dwarf stars parameterized by tidal strengths in the range β = 4–23. High spatial resolution elucidates the manner and conditions leading to thermonuclear detonation, linking the initiation sequence to stellar composition and tidal strength. All of our models suffer sustained detonations triggered by a combination of adiabatic compression, mild thermonuclear preconditioning, and collisional heating, in degrees depending primarily on tidal strength. We find that many diagnostics, such as temperature, total released energy, and iron-group products, are fairly well converged (better than 10%) at resolutions below 10 km along the scale height of the orbital plane. The exceptions are intermediate-mass transients like calcium, which remain uncertain up to factors of 2, even at 1 km resolution.

79 ASTRONOMY AND ASTROPHYSICS↗

A graph neural network (GNN) approach to basin-scale river network learning: the role of physics-based connectivity and data fusion

Abstract. Rivers and river habitats around the world are under sustained pressure from human activities and the changing global environment. Our ability to quantify and manage the river states in a timely manner is critical for protecting the public safety and natural resources. In recent years, vector-based river network models have enabled modeling of large river basins at increasingly fine resolutions, but are computationally demanding. This work presents a multistage, physics-guided, graph neural network (GNN) approach for basin-scale river network learning and streamflow forecasting. During training, we train a GNN model to approximate outputs of a high-resolution vector-based river network model; we then fine-tune the pretrained GNN model with streamflow observations. We further apply a graph-based, data-fusion step to correct prediction biases. The GNN-based framework is first demonstrated over a snow-dominated watershed in the western United States. A series of experiments are performed to test different training and imputation strategies. Results show that the trained GNN model can effectively serve as a surrogate of the process-based model with high accuracy, with median Kling–Gupta efficiency (KGE) greater than 0.97. Application of the graph-based data fusion further reduces mismatch between the GNN model and observations, with as much as 50 % KGE improvement over some cross-validation gages. To improve scalability, a graph-coarsening procedure is introduced and is demonstrated over a much larger basin. Results show that graph coarsening achieves comparable prediction skills at only a fraction of training cost, thus providing important insights into the degree of physical realism needed for developing large-scale GNN-based river network models.

54 ENVIRONMENTAL SCIENCES↗

Summary Report for National Aeronautics Space Administration (NASA) and Centro Para Prevencao da Poluicao (C3P) 2011 International Workshop on Environment and Alternative Energy

The C3P &. NASA International Workshop on Environment and Alternative Energy was held on November 15-18, 2011 at the European Space Agency (ESA)'s Research and Technology Centre (ESTEC) in Noordwijk, The Netherlands. The theme of the workshop was "Global Collaboration in Environmental and Alternative Energy Strategies". The workshop was held at ESTEC's conference center. More than 110 individuals from eleven countries attended the workshop. For the first time since the inception of NASA-C3P workshops, a full day was dedicated to a student session. Fifteen students from around the globe gave oral presentations along with poster displays relating to the latest technologies in environmental and alternative energy strategies. Judges from NASA, C3P and ESA awarded plaques to the top three students. In addition to the students, thirty eight U.S. and international subject matter experts presented on the following general environmental-related topics: (1) Hazardous materials management and substitution in support of space operations (2) Emerging renewable and alternative energy technologies (3) Sustainable development and redevelopment (4) Remediation technologies and strategies The workshop also included a panel discussion on the topic of the challenges of operating installations across borders. Throughout the workshop, attendees heard about the scope of environmental and energy challenges that industry and governments face. They heard about technologies for increasing energy efficiency and increasing use of renewable energy. They learned about ways companies and government agencies are using materials, processes, goods and services in a manner more respectful with the environment and in compliance with health and safety rules. The concept of partnerships and their inherent benefits was evidenced throughout the workshop. Partnering is a key aspect of sustainability because sustainable development is complicated. Through formal presentations and side discussions, attendees commented on the need for continued exploration of joint projects of mutual interest.

Greene, Brian↗

NASA Human Spaceflight Scenarios - Do All Our Models Still Say No?

Historically, NASA human spaceflight planning has included healthy doses of life cycle cost analysis. Planners put projects and their cost estimates in a budget context. Estimated costs became expected budgets. Regardless, real budgets rarely matched expectations. So plans would come and go as NASA canceled projects. New projects would arise and the cycle would begin again. Repeatedly, NASA schedule and performance ambitions come up against costs growing at double-digit rates while budgets barely rise a couple of percent a year. Significant skepticism greets proposed NASA programs at birth, as cost estimates for new projects are traditionally very high, and worse, far off the mark for those carried forward. In this environment the current "capability driven framework" for NASA human spaceflight evolved, where long term life cycle cost analysis are even viewed as possibly counter-productive. Here, a space exploration project, for example the Space Launch System, focuses on immediate goals. A life cycle is that of a project, not a program, and for only that span of time to a near term milestone like a first test launch. Unfortunately, attempting to avoid some pitfalls in long-term life cycle cost analysis breeds others. Government audits have noted that limiting the scope of cost analysis "does not provide the transparency necessary to assess long-term affordability" making it difficult to understand if NASA "is progressing in a cost-effective and affordable manner." Even in this short-term framework, NASA realizes the importance of long-term considerations, that it must "maximize the efficiency and sustainability of the Exploration Systems development programs", that this is "critical to free resources for re-investment...such as other required deep space exploration capabilities." Assuming the value of long-term life cycle cost analysis, where due diligence meets reconnaissance, and accepting past shortcomings, the work here approaches life cycle cost analysis for human spaceflight differently. 1) If costs have traditionally been so high that adding them up is discouraging, are there any new facts on the ground offering paths to significantly lower costs? 2) If NASA's spaceflight budget and process is an over-arching constraint, with its planning limitations favoring short-term outlooks, is there a way to step outside the budget box? 3) If life cycle answers have historically been too uncertain to be useful, is there a process where stakeholders gain valuable insights merely from emphasizing a common understanding around questions? We analyze the potential life cycle cost of assorted NASA human spaceflight architectures - an architecture as a sum of individual systems, working together. With the prior questions of high costs, limited budgets and uncertainties in mind, public private partnerships are central in these architectures. The cost data for current commercial public private partnerships is encouraging, as are cost estimates for future partnership approaches beyond low Earth orbit. Private capital, directly or indirectly, an ingredient of public private partnerships, may be a significant factor in finding a path around the limits of the NASA spaceflight budget. Also, understanding and reviewing the pros, cons and uncertainties of assorted architectures can assist in developing a common understanding around key questions as important if not more so than the numbers and answers. Lastly, a scenario planning technique is briefly explored that can mature a common understanding about the agencies situation at hand and how diverse stakeholders can go forward together. Scenario planning, rather than focusing on answers, places emphasis on stakeholders developing a common understanding about the future. Putting aside costs, this is especially true of questions about sustainability and growth, results, benefits and expectations. While efficiency exercises or analysis look to reduce resources in one place to apply them elsewhere, moving around slices in a pie, scenario planning can get at the heart of the matter, growing the pie, transforming it, and making the pieces relevant. Especially important is the question of sustainability for different scenarios in the broad sense of the word - not just the narrow ability to survive or continue, but also the ability to adapt, prosper and grow.

space systems life cycle costs↗

Reinforcement Learning for Intentional Islanding in Resilient Power Transmission Systems

Intentional islanding is the process of identifying and deliberately decomposing the transmission network to form self-sustained islands from an endangered network during disruptions to improve resilience and security. Most existing intentional islanding models are offline resilience decision tools and hence do not provide outage responses in a timely manner. In this paper, a reinforcement learning (RL) based model for intentional islanding is developed, which offers real-time switching control, online deployability, and adaptability to varying system conditions. The intentional islanding process is formulated as a Markov decision process, where the optimal transmission switching policy is learned using the RL approach. The control policy is learned over an environment that encompasses a Power System Simulator for Engineering (PSS/E) model of the transmission network, facilitated by an interface to the standard openAI Gym framework. The proposed RL-based methodology aims to form stable and self-sustainable islands by ensuring voltage stability while reducing the power mismatch in the formed islands. A proximal policy optimization algorithm is designed, which is suitable for controlling the on/off status of the switches with multi-layer perceptron as value and actor networks. The effectiveness of the proposed framework in the self-recovery of the grid by island formation is applied on the modified IEEE 39-bus test network and validated by dynamic simulations.

24 POWER TRANSMISSION AND DISTRIBUTION↗

A new framework to map fine resolution cropping intensity across the globe: Algorithm, validation, and implication

We report accurate estimation of cropping intensity (CI), an indicator of food production, is well aligned with the ongoing efforts to achieve sustainable development goals (SDGs) under diminishing natural resources. The advancement in satellite remote sensing provides unprecedented opportunities for capturing CI information in a spatially continuous manner. However, challenges remain due to the lack of generalizable algorithms for accurately and efficiently mapping global CI with a fine spatial resolution. In this study, we developed a 30-m planetary-scale CI mapping framework with the reconstructed time series of Normalized Difference Vegetation Index (NDVI) from multiple satellite images. Using a binary crop phenophase profile indicating growing and non-growing periods, we estimated pixel-by-pixel CI by enumerating the total number of valid cropping cycles during the study years. Based on the Google Earth Engine cloud computing platform, we implemented the framework to estimate CI during 2016–2018 in eight geographic regions across continents that are representative of global cropping system diversity. Comparison with PhenoCam network data in four cropland sites suggests that the proposed framework is capable of capturing the seasonal dynamics of cropping practices. Spatially, overall accuracies based on validation samples range from 80.0% to 98.9% across different regions worldwide. Regarding the CI classes, single cropping systems are associated with more robust and less biased estimations than multiple cropping systems. Finally, our CI estimates reveal high agreement with two widely used land surface phenology products, including Vegetation Index and Phenology V004 (VIP4) and Moderate Resolution Imaging Spectroradiometer Land Cover Dynamics (MCD12Q2), meanwhile providing much more spatial details. Due to its robustness, the developed CI framework can be potentially generalized to produce global fine resolution CI products for food security and other applications.

54 ENVIRONMENTAL SCIENCES↗

Frontier In-Situ Resource Utilization for Enabling Sustained Human Presence on Mars

The currently known resources on Mars are massive, including extensive quantities of water and carbon dioxide and therefore carbon, hydrogen and oxygen for life support, fuels and plastics and much else. The regolith is replete with all manner of minerals. In Situ Resource Utilization (ISRU) applicable frontier technologies include robotics, machine intelligence, nanotechnology, synthetic biology, 3-D printing/additive manufacturing and autonomy. These technologies combined with the vast natural resources should enable serious, pre- and post-human arrival ISRU to greatly increase reliability and safety and reduce cost for human colonization of Mars. Various system-level transportation concepts employing Mars produced fuel would enable Mars resources to evolve into a primary center of trade for the inner solar system for eventually nearly everything required for space faring and colonization. Mars resources and their exploitation via extensive ISRU are the key to a viable, safe and affordable, human presence beyond Earth. The purpose of this paper is four-fold: 1) to highlight the latest discoveries of water, minerals, and other materials on Mars that reshape our thinking about the value and capabilities of Mars ISRU; 2) to summarize the previous literature on Mars ISRU processes, equipment, and approaches; 3) to point to frontier ISRU technologies and approaches that can lead to safe and affordable human missions to Mars; and 4) to suggest an implementation strategy whereby the ISRU elements are phased into the mission campaign over time to enable a sustainable and increasing human presence on Mars.

Moses, Robert W.↗

A Multi-Criteria Impact Evaluation Methodology Applied to FLEX Strategies in Nuclear Power Plants

As responses to Fukushima Dai-ichi nuclear accident, several advanced, near-term technologies have been or are being introduced to enhance safety of operating nuclear power plants (NPPs) as well as improving their sustainability. Examples include Accident-Tolerant Fuel designs, Diverse and Flexible Coping Strategies (FLEX), and passive cooling system designs. The combinations of these technologies, coupled with enhancements to plant components and systems and improved fuel cycle efficiency, constitute a concept of Enhanced Resilient Plant Systems, which is proposed and being explored by Idaho National Laboratory (INL) under the Risk-Informed Systems Analysis Pathway of the U.S. Department of Energy’s Light Water Reactor Sustainability Program. To decide if introducing a technology is necessary or worthy, the impacts of this technology on NPPs should be evaluated, preferably in a quantitative manner, and provided to decision makers. This paper summarizes an on-going work conducted by the authors on developing a multi-criteria impact evaluation methodology. This methodology is expected to be applicable to evaluate a variety of technologies, while FLEX strategy is adopted as a case study for this paper.

99 GENERAL AND MISCELLANEOUS↗

Onward to Petaflops Computing

With programs such as the US High Performance Computing and Communications Program (HPCCP), the attention of scientists and engineers worldwide has been focused on the potential of very high performance scientific computing, namely systems that are hundreds or thousands of times more powerful than those typically available in desktop systems at any given point in time. Extending the frontiers of computing in this manner has resulted in remarkable advances, both in computing technology itself and also in the various scientific and engineering disciplines that utilize these systems. Within the month or two, a sustained rate of 1 Tflop/s (also written 1 teraflops, or 10(exp 12) floating-point operations per second) is likely to be achieved by the 'ASCI Red' system at Sandia National Laboratory in New Mexico. With this objective in sight, it is reasonable to ask what lies ahead for high-end computing.

Bailey, David H.↗

Strategies for Semiconductor/Electrocatalyst Coupling toward Solar‐Driven Water Splitting

Abstract Hydrogen (H 2 ) has a significant potential to enable the global energy transition from the current fossil‐dominant system to a clean, sustainable, and low‐carbon energy system. While presently global H 2 production is predominated by fossil‐fuel feedstocks, for future widespread utilization it is of paramount importance to produce H 2 in a decarbonized manner. To this end, photoelectrochemical (PEC) water splitting has been proposed to be a highly desirable approach with minimal negative impact on the environment. Both semiconductor light‐absorbers and hydrogen/oxygen evolution reaction (HER/OER) catalysts are essential components of an efficient PEC cell. It is well documented that loading electrocatalysts on semiconductor photoelectrodes plays significant roles in accelerating the HER/OER kinetics, suppressing surface recombination, reducing overpotentials needed to accomplish HER/OER, and extending the operational lifetime of semiconductors. Herein, how electrocatalyst coupling influences the PEC performance of semiconductor photoelectrodes is outlined. The focus is then placed on the major strategies developed so far for semiconductor/electrocatalyst coupling, including a variety of dry processes and wet chemical approaches. This Review provides a comprehensive account of advanced methodologies adopted for semiconductor/electrocatalyst coupling and can serve as a guideline for the design of efficient and stable semiconductor photoelectrodes for use in water splitting.

Thalluri, Sitaramanjaneya Mouli↗

Nevada National Security Site Demonstration Reactor Siting and Capabilities Study

The NNSS Demonstration Reactor Siting and Capabilities study identifies siting opportunities supporting the demonstration of advanced and emerging reactor designs and operations in a manner that optimizes these activities within the NNSS physical, operational, and regulatory footprint considering relevant evaluation factors to ensure the designated site locations provide the necessary defense-in-depth for safe and secure sustained operations.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

Lightning discharge protection rod

A system for protecting an in-air vehicle from damage due to a lighning strike is disclosed. It is an extremely simple device consisting of a sacrificial graphite composite rod, approximately the diameter of a pencil with a length of about five inches. The sacrificial rod is constructed with the graphite fibers running axially within the rod in a manner that best provides a path of conduction axially from the trailing edge of an aircraft to the trailing end of the rod. The sacrificial rod is inserted into an attachment hole machined into trailing edges of aircraft flight surfaces, such as a vertical fin cap and attached with adhesive in a manner not prohibiting the conduction path between the rod and the aircraft. The trailing end of the rod may be tapered for aerodynamic and esthetic requirements. This rod is sacrificial but has the capability to sustain several lightning strikes and still provide protection.

Bryan, Charles F., Jr.↗

Risk-informed Physical Security Using Dynamic Force-on-Force Modelling Tools (ABSTRACT)

Physical security requirement of nuclear power plants (NPPs) in the US is regulated in a mainly prescriptive manner. This “one size fits all” approach may consequently overlook plant-specific characteristics which are beneficial for the inherent safety and security of the plant. Although a performance-based security measure has been promulgated in 10 CFR 73.55(r), current evaluation methods generally emphasize static and conservative assumptions on physical security uncertainties. This conservatism contributes to the overall operational and maintenance costs, which account to 70% of total operating expenditures for an NPP. This paper describes an ongoing work at the Idaho National Laboratory within the Light Water Reactor Sustainability pathway, which aims to optimize physical protection system with regards to system effectiveness and dollar costs. To achieve this goal, a risk-informed approach to physical security is proposed. This approach leverages the Event Modeling Risk Assessment using Linked Diagrams (EMRALD) tool to model facility infiltration and Force-on-Force (FoF) engagement in a dynamic manner. The dynamic FoF analysis was conducted by coupling human performance uncertainties modeled in EMRALD to existing commercial 3-dimensional FoF software, i.e. SCRIBE3D, AVERT and Simajin. Meanwhile, risk analysis was accomplished by coupling the attack outcomes to existing plant Probabilistic Risk Assessment (PRA) model with FLEX strategy. This approach reduces the conservatisms in security modeling and further acknowledges the possibility for plant operators to mitigate the attack outcomes. A sabotage attack on a hypothetical NPP facility was devised to demonstrate the proposed methodology. Dynamic FoF rules were implemented in EMRALD coupled to SCRIBE3D. This dynamic evaluation revealed an additional 21% system effectiveness in protecting the target set relative to the static modelling approach. Furthermore, the conditional core damage probability could be reduced by up to 46% by crediting operator actions in mitigating the sabotage outcomes. We evaluated the relative importance of each component of the physical security posture included in the model and assessed tradeoffs between components to identify potential opportunities for cost reduction while maintaining a specific level of system effectiveness. Results of the cost analysis will be presented in the conference. This study is expected to help NPP operators in allocating resources optimally to satisfy the security requirements.

97 MATHEMATICS AND COMPUTING↗