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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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DOE OSTI2024

Distributed optimization for multi-commodity urban traffic control

A distributed method for concurrent traffic signal and routing control of traffic networks is proposed. The method is based on the multi-commodity store-and-forward model, in which the destinations are the commodities. The system benefits from the communication between vehicles and infrastructure, providing optimal signal timings to intersections and routes to vehicles on a link-by-link basis. Using the augmented Lagrangian to model the constraints into the objective, the baseline centralized problem is decomposed into a set of objective-coupled subproblems, one for each intersection, enabling the solution to be computed by a distributed- gradient projection algorithm. Further, the intersection agents only need to communicate and coordinate with neighboring intersections to ensure convergence to the optimal solution while tolerating suboptimal iterations that offer more flexibility, unlike other distributed approaches. Through microsimulation, we demonstrate the effectiveness of the proposed algorithm in traffic networks with time-varying demand. Computational analysis shows that the distributed problem is suitable for real-time applications. A robustness analysis show that the distributed formulation enables a graceful degradation of the system in case of failure.

Augmented Lagrangian↗

DOE OSTI2013

Accelerating semantic graph databases on commodity clusters

We are developing a full software system for accelerating semantic graph databases on commodity cluster that scales to hundreds of nodes while maintaining constant query throughput. Our framework comprises a SPARQL to C++ compiler, a library of parallel graph methods and a custom multithreaded runtime layer, which provides a Partitioned Global Address Space (PGAS) programming model with fork/join parallelism and automatic load balancing over a commodity clusters. We present preliminary results for the compiler and for the runtime.

commodity clusters↗

DOE OSTI2020

Self-healing magnetic nanocomposites with robust mechanical properties and high magnetic actuation potential prepared from commodity monomers via graft-from approach

Herein, we report the design, synthesis and characterization of self-healing magnetic nanocomposites prepared from readily available commodity monomers. These multi-functional materials demonstrate robust mechanical properties, with a Young's modulus of 70 MPa and over 500% extensibility. The magnetic nanocomposites also show self-healing ability, achieving 46% recovery of extensibility in 5 hours in ambient conditions while retaining high magnetic actuation with a commodity magnet.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2017

Product-Focused Innovation and Value Creation are Needed to Drive Commodity-Scale Algae Production

Microalgae’s (algae) productivity can greatly exceed that of terrestrial plants. Scientists, policy makers, entrepreneurs, and investors have long hoped to harness these high biomass yields to produce novel solutions for energy and nutrition. Despite nearly 60 years of research and development efforts, commodity-scale production of algae food or fuels has yet to materialize. A recent pivot in focus from fuels to food by the algal biotechnology industry presents an opportunity to evaluate historical challenges to commodity-scale production. Food and fuel commercialization efforts are compared below though a lens of product-focused innovation strategy. Here, this analysis is then used to identify several recommendations to enable industry growth.

59 BASIC BIOLOGICAL SCIENCES↗

DOE OSTI2017

Rapid Calculation of Max-Min Fair Rates for Multi-Commodity Flows in Fat-Tree Networks

Max-min fairness is often used in the performance modeling of interconnection networks. Existing methods to compute max-min fair rates for multi-commodity flows have high complexity and are computationally infeasible for large networks. In this paper, we show that by considering topological features, this problem can be solved efficiently for the fat-tree topology that is widely used in data centers and high performance compute clusters. Several efficient new algorithms are developed for this problem, including a parallel algorithm that can take advantage of multi-core and shared-memory architectures. Using these algorithms, we demonstrate that it is possible to find the max-min fair rate allocation for multi-commodity flows in fat-tree networks that support tens of thousands of nodes. We evaluate the run-time performance of the proposed algorithms and show improvement in orders of magnitude over the previously best known method. Finally, we further demonstrate a new application of max-min fair rate allocation that is only computationally feasible using our new algorithms.

97 MATHEMATICS AND COMPUTING↗

DOE OSTI2015

Efficient Execution of Recursive Programs on Commodity Vector Hardware

The pursuit of computational efficiency has led to the proliferation of throughput-oriented hardware, from GPUs to increasingly-wide vector units on commodity processors and accelerators. This hardware is designed to efficiently execute data-parallel computations in a vectorized manner. However, many algorithms are more naturally expressed as divide-and-conquer, recursive, task-parallel computations; in the absence of data parallelism, it seems that such algorithms are not well-suited to throughput-oriented architectures. This paper presents a set of novel code transformations that expose the data-parallelism latent in recursive, task-parallel programs. These transformations facilitate straightforward vectorization of task-parallel programs on commodity hardware. We also present scheduling policies that maintain high utilization of vector resources while limiting space usage. Across several task-parallel benchmarks, we demonstrate both efficient vector resource utilization and substantial speedup on chips using Intel's SSE4.2 vector units as well as accelerators using Intel's AVX512 units.

resursion↗

DOE OSTI2013

Integrated Electrochemical Processes for CO 2 Capture and Conversion to Commodity Chemicals

The Massachusetts Institute of Technology (MIT) and Siemens Corporations (SCR) are developing new chemical synthesis processes for commodity chemicals from CO 2 . The process is assessed as a novel chemical sequestration technology that utilizes CO 2 from dilute gas streams generated at industrial carbon emitters as a raw material to produce useful commodity chemicals. Work at Massachusetts Institute of Technology (MIT) commenced on October 1st, 2010, and finished on September 30th, 2013. During this period, we have investigated and accomplished five objectives that mainly focused on converting CO 2 into high-value chemicals: 1) Electrochemical assessment of catalytic transformation of CO 2 and epoxides to cyclic carbonates; 2) Investigation of organocatalytic routes to convert CO 2 and epoxide to cyclic carbonates; 3) Investigation of CO 2 Capture and conversion using simple olefins under continuous flow; 4) Microwave assisted synthesis of cyclic carbonates from olefins using sodium bicarbonates in a green pathway; 5) Life cycle analyses of integrated chemical sequestration process. In this final report, we will describe the detailed study performed during the three year period and findings and conclusions drawn from our research.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

NASA NTRS1974

Domestic wash water reclamation for reuse as commode water supply using filtration: Reverse-osmosis separation technique

A combined filtration-reverse-osmosis water recovery system has been evaluated to determine its capability to reclaim domestic wash water for reuse as a commode water supply. The system produced water that met all chemical and physical requirements established by the U.S. Public Health Service for drinking water with the exception of carbon chloroform extractables, methylene blue active substances, and phenols. It is thought that this water is of sufficient quality to be reused as commode supply water. The feasibility of using a combined filtration and reverse-osmosis technique for reclaiming domestic wash water has been established. The use of such a technique for wash-water recovery will require a maintenance filter to remove solid materials including those less than 1 micron in size from the wash water. The reverse-osmosis module, if sufficiently protected from plugging, is an attractive low-energy technique for removing contaminants from domestic wash water.

Hall, J. B., Jr.↗

NASA NTRS1998

Building and managing high performance, scalable, commodity mass storage systems

The NAS Systems Division has recently embarked on a significant new way of handling the mass storage problem. One of the basic goals of this new development are to build systems at very large capacity and high performance, yet have the advantages of commodity products. The central design philosophy is to build storage systems the way the Internet was built. Competitive, survivable, expandable, and wide open. The thrust of this paper is to describe the motivation for this effort, what we mean by commodity mass storage, what the implications are for a facility that performs such an action, and where we think it will lead.

Lekashman, John↗

NASA NTRS1997

Predicting Cost/Performance Trade-Offs for Whitney: A Commodity Computing Cluster

Recent advances in low-end processor and network technology have made it possible to build a "supercomputer" out of commodity components. We develop simple models of the NAS Parallel Benchmarks version 2 (NPB 2) to explore the cost/performance trade-offs involved in building a balanced parallel computer supporting a scientific workload. We develop closed form expressions detailing the number and size of messages sent by each benchmark. Coupling these with measured single processor performance, network latency, and network bandwidth, our models predict benchmark performance to within 30%. A comparison based on total system cost reveals that current commodity technology (200 MHz Pentium Pros with 100baseT Ethernet) is well balanced for the NPBs up to a total system cost of around $1,000,000.

Becker, Jeffrey C.↗

NASA NTRS1998

Predicting Cost/Performance Trade-offs For Whitney: A Commodity Computing Cluster

Recent advances in low-end processor and network technology have made it possible to build a "supercomputer" out of commodity components. We develop simple models of the NAS Parallel Benchmarks version 2 (NPB 2) to explore the cost/performance trade-offs involved in building a balanced parallel computer supporting a scientific workload. By measuring single processor benchmark performance, network latency, and network bandwidth, and using closed form expressions detailing the number and size of messages sent by each benchmark, our models predict benchmark performance to within 30%. A comparison based on total system cost reveals that current commodity technology (200 MHz Pentium Pros with 100baseT Ethernet) is well balanced for the NPBs up to a total system cost of around $ 1,000,000.

Becker, Jeffrey C.↗

NASA NTRS2018

Orbital Syngas Commodity Augmentation Reactor (OSCAR)

The goal of the Orbital Syngas Commodity Augmentation Reactor (OSCAR) project is to study and develop Trash to Gas (TtG) technology in a microgravity environment. This could be implemented on the International Space Station (ISS) and future deep space exploration missions involving long-term human habitation. TtG technology will be used to convert trash and human waste into useful gasses such as methane, hydrogen, water, and carbon dioxide. This will both reduce the spacecraft pressurized volume dedicated for waste storage and provide gaseous commodities that have energy storage and life support applications. As a fall 2018 intern on the OSCAR team at Kennedy Space Center, I helped to prepare the experimental setup for microgravity testing in the drop tower at Glenn Research Center.

McClure, Thomas S.↗

DOE OSTI2011

Crunching Large Graphs with Commodity Processors

Crunching large graphs is the basis of many emerging appli- cations, such as social network analysis and bioinformatics. Graph analytics algorithms exhibit little locality and therefore present significant performance challenges. Hardware multi- threading systems (e.g, Cray XMT) show that with enough concurrency, we can tolerate long latencies. Unfortunately, this solution is not available with commodity parts. Our goal is to develop a latency-tolerant system built out of commodity parts and mostly in software. The proposed system includes a runtime that supports a large number of lightweight contexts, full-bit synchronization and a memory manager that provides a high-latency but high-bandwidth global shared memory. This paper lays out the vision for our system, and justifies its feasibility with a performance analysis of the run- time for latency tolerance.

99 GENERAL AND MISCELLANEOUS↗

DOE OSTI2013

Build Less Code, Deliver More Science: An Experience Report on Composing Scientific Environments using Component-based and Commodity Software Platforms

Modern scientific software is daunting in its diversity and complexity. From massively parallel simulations running on the world’s largest supercomputers, to visualizations and user support environments that manage ever growing complex data collections, the challenges for software engineers are plentiful. While high performance simulators are necessarily specialized codes to maximize performance on specific supercomputer architectures, we argue the vast majority of supporting infrastructure, data management and analysis tools can leverage commodity open source and component-based technologies. This approach can significantly drive down the effort and costs of building complex, collaborative scientific user environments, as well as increase their reliability and extensibility. In this paper we describe our experiences in creating an initial user environment for scientists involved in modeling the detailed effects of climate change on the environment of selected geographical regions. Our approach composes the user environment using the Velo scientific knowledge management platform and the MeDICi Integration Framework for scientific workflows. These established platforms leverage component-based technologies and extend commodity open source platforms with abstractions and capabilities that make them amenable for broad use in science. Using this approach we were able to deliver an operational user environment capable of running thousands of simulations in a 7 month period, and achieve significant software reuse.

Gorton, Ian↗

DOE OSTI2020

Strategic Trade Atlas 2014-2018. Country- and Commodity-Based Views

A Strategic Trade Atlas was developed to promote understanding of global trade flows of strategic goods, i.e., goods of militarily strategic value, including dual-use goods. This Atlas provides macroscopic graphical representations of global trade flows classified under Harmonized System (HS) codes associated by the World Customs Organization with strategic commodities. The profiles provide information rich representations of strategic commodity-related imports and exports classified under these HS codes, based on data originally reported to and made publicly available by the United Nations Statistical Division, then processed to reconcile trade asymmetries by the Centre d'Etudes Prospectives et d'Informations Internationales. This and other high quality, statistically relevant data sources exist, but are largely untapped resources for strategic trade control purposes. Efforts to promote and facilitate use of trade data should enhance the effectiveness and efficiency of strategic trade control efforts.

strategic trade, world customs organization, trade↗

DOE OSTI2021

Strategic Trade Atlas 2015-2019: Country- and Commodity-Based Views

strategic trade, world customs organization, trade↗

DOE OSTI2018

Estimation of Commodity Origin-Destination Matrices and Flows: The Network Tomography of U.S. Wheat Shipments

This study proceeds from the belief that an examination of railroads and railcar flows provides important insights into economic geography and to the economics of transportation. The flows of wheat in the United States are examined using rail carload waybill survey data in order to model the network routes likely taken from origin to destination, a characterization of the flows themselves, and modeling the flows through the comparison of standard gravity models with two relatively new gravity estimation methodologies suggested in the network analysis literature. The analysis covers Wheat flows through the U.S. for the years 2013 through 2015. Rail flows are highly conducive to the emergence of high volume corridors, a primary hypothetical relationship described by Taaffe, Morrill and Gould (1963). Hubs are expected to develop in market centers with sufficient traffic, as in a Christaller (1966) system, where market centers above a certain size have terminal facilities, or serve as primary interchange points. Centers of different sizes may also have more than one load center thereby concentrating and attracting more flows (o’Kelly, 1998). Implications are for commodity production and processing locations to develop concentrations of flows and the development of identifiable commodity-specific components of the national rail network. As the railroad nodes are structured in relation to the railroad network, the origin and destination nodes take the form of an irregular lattice (Besag 1974). One implication of this irregular lattice network is the probable presence of network autocorrelation in the flows: the constraints of network connectivity assure flows are not open between the terminals, but travel to and from distinct neighbors on the network. In addition, the network terminal structure can be expected to follow a hierarchical central place ordering. Evidence of such an ordering may be determined by examining the clustering and concentration of flows at nodes and, by association, particular network links serving those nodes (Fujita and Thisse 2002; Hesse and Rodrigue 2004; Nierat 1997). The presence of hierarchies implies economies of scale are being realized which leads to a centralizing or agglomerating effect (Fujita and Thisse, 2002 and Brakman et al, 2001). Thus the transportation sector will also develop an associated central place hierarchy with its own associated network of flows and flow concentrations.

Peterson, Steven↗

DOE OSTI2011

A Review on Biomass Densification Systems to Develop Uniform Feedstock Commodities for Bioenergy Application

Developing uniformly formatted, densified feedstock from lignocellulosic biomass is of interest to achieve consistent physical properties like size and shape, bulk and unit density, and durability, which significantly influence storage, transportation and handling characteristics, and, by extension, feedstock cost and quality. A variety of densification systems are considered for producing a uniform format feedstock commodity for bioenergy applications, including (a) baler, (b) pellet mill, (c) cuber, (d) screw extruder, (e) briquette press, (f) roller press, (g) tablet press, and (g) agglomerator. Each of these systems has varying impacts on feedstock chemical and physical properties, and energy consumption. This review discusses the suitability of these densification systems for biomass feedstocks and the impact these systems have on specific energy consumption and end product quality. For example, a briquette press is more flexible in terms of feedstock variables where higher moisture content and larger particles are acceptable for making good quality briquettes; or among different densification systems, a screw press consumes the most energy because it not only compresses but also shears and mixes the material. Pretreatment options like preheating, grinding, steam explosion, torrefaction, and ammonia fiber explosion (AFEX) can also help to reduce specific energy consumption during densification and improve binding characteristics. Binding behavior can also be improved by adding natural binders, such as proteins, or commercial binders, such as lignosulphonates. The quality of the densified biomass for both domestic and international markets is evaluated using PFI (United States Standard) or CEN (European Standard).

09 BIOMASS FUELS↗