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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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At least 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS1992

Data parallel sorting for particle simulation

Sorting on a parallel architecture is a communications intensive event which can incur a high penalty in applications where it is required. In the case of particle simulation, only integer sorting is necessary, and sequential implementations easily attain the minimum performance bound of O (N) for N particles. Parallel implementations, however, have to cope with the parallel sorting problem which, in addition to incurring a heavy communications cost, can make the minimun performance bound difficult to attain. This paper demonstrates how the sorting problem in a particle simulation can be reduced to a merging problem, and describes an efficient data parallel algorithm to solve this merging problem in a particle simulation. The new algorithm is shown to be optimal under conditions usual for particle simulation, and its fieldwise implementation on the Connection Machine is analyzed in detail. The new algorithm is about four times faster than a fieldwise implementation of radix sort on the Connection Machine.

Dagum, Leonardo↗
DOE OSTI2019

Material sorting system

A material sorting system sorts materials, such as scrap pieces composed of unknown metal alloys, as a function of their detected x-ray fluorescence. The x-ray fluorescence may be converted into an elemental composition signature that is then compared to an elemental composition signature of a reference material in order to identify and/or classify each of the materials, which are then sorted into separate groups based on such an identification/classification. The material sorting system may include an in-line x-ray tube having a plurality of separate x-ray sources, each of which can irradiate a separate stream of materials to be sorted.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Material sorting using a vision system

A material sorting system sorts materials utilizing a vision system that implements a machine learning system in order to identify or classify each of the materials, which are then sorted into separate groups based on such an identification or classification. The material sorting system may include an x-ray fluorescence system to perform a classification of the materials in combination with the vision system, whereby the classification efforts of the vision system and x-ray fluorescence system are combined in order to classify and sort the materials.

Kumar, Nalin↗
DOE OSTI2025

Alloy selective optical sorting of mixed post-consumer aluminum scrap streams

Shredded post-consumer non-ferrous scrap stream, also known as Zorba, contains a mixture of cast and wrought aluminum pieces with very different compositions. Cast Al pieces, with their high Si, Cu and Fe content, are a major contaminant in wrought scrap fraction, which results in downcycling of the mixed cast + wrought scrap into non-structural cast Al alloys and parts. Here, in this paper, we introduce a chemical treatment method to color-code scrap aluminum pieces by alloy family and demonstrate low-cost optical sorting of cast from wrought pieces to upgrade the scrap stream. We utilized non-acidic chemical solutions that react with (i.e., etch) the scrap pieces to produce colors based on the Al alloy chemistry of a given piece. Cast pieces with high Si and Cu fractions turned black, whereas the much leaner wrought pieces remained unreacted. We showed > 95% sorting efficiency of mixed cast and wrought pieces using a repurposed low-cost optical sorter originally designed for food sorting. We also colored wrought Al pieces by alloy families, such as 5xxx and 6xxx, using a two-step chemical etching technique, which has the potential to create a circular supply chain in which wrought aluminum alloys are sorted from the mixed scrap stream and recycled back to high-value wrought products such as sheets, extrusions, and forgings with minimal contamination from cast scrap.

Aluminum↗
DOE OSTI2019

Self–Sorting of 10–µm–Long Single–Walled Carbon Nanotubes in Aqueous Solution

Single-walled carbon nanotubes (SWCNTs) are a class of 1D nanomaterials that exhibit extraordinary electrical and optical properties. However, many of the fundamental studies and practical applications are stymied by sample polydispersity. SWCNTs are synthesized in bulk with broad structural (chirality) and geometrical (length and diameter) distributions; problematically, all known post-synthetic sorting methods rely on ultrasonication, which cuts SWCNTs into short segments (typically <1 μm). Here it is demonstrated that ultralong (>10 μm) SWCNTs can be efficiently separated from the shorter ones through a solution-phase “self-sorting.” It is shown that thin film transistors fabricated from long semiconducting SWCNTs exhibit a carrier mobility as high as ≈90 cm 2 V –1 s –1 , which is ≈10 times higher than the shorter counterparts and well exceeding other known materials such as organic semiconducting polymers (<1 cm 2 V –1 s –1 ), amorphous silicon (≈1 cm 2 V –1 s –1 ), and nanocrystalline silicon (≈50 cm 2 V –1 s –1 ). Mechanistic studies suggest that this self-sorting relies on the equilibrium between isotropic and liquid crystalline SWCNT phases, which is driven by the solution phase behavior above the cloud point of the isotropic phase, and inversely scales with the SWCNT length. Furthermore, this length-dependent self-sorting technique opens a path to attain the long- sought ultralong, electronically pure carbon nanotube materials through scalable solution processing.

36 MATERIALS SCIENCE↗
DOE OSTI2018

A Fundamental Frequency Sorting Algorithm for Capacitor Voltage Balance of Modular Multilevel Converter With Low-Frequency Carrier Phase Shift Modulation

This paper proposes a fundamental frequency sorting algorithm for balancing the floating capacitors in modular multilevel converters with low-frequency carrier phase shift modulation. The relationship between the driving pulses and submodules (SMs) is rebuilt in every fundamental period by sorting the voltage increments and present voltages. Besides, an improved and simplified strategy is proposed to predict the charging abilities of the driving pulses, so as to avoid sorting the voltage increments. Based on the proposed method, the switching frequency of each power device and the carrier frequency are identical, which reduces the operational losses for applications regarding high power. At the same time, the sorting frequency is as low as the fundamental frequency, which alleviates a large amount of computational cost, and the necessity to measure arm currents is omitted. In this case, the arm current sensors are eliminated, and simplified communication among the central controller and the local ones is set up. Finally, a three-phase 1-MVA simulation platform with 120 SMs and a down-scaled 6-kVA experimental prototype with 48 SMs are constructed to validate the proposed approach.

42 ENGINEERING↗
DOE OSTI2017

The Power of Exclusion using Automated Osteometric Sorting: Pair‐Matching,

Abstract This study compares the original pair‐matching osteometric sorting model ( J Forensic Sci 2003 ;48:717) against two new models providing validation and performance testing across three samples. The samples include the Forensic Data Bank, USS Oklahoma , and the osteometric sorting reference used within the Defense POW / MIA Accounting Agency. A computer science solution to generating dynamic statistical models across a commingled assemblage is presented. The issue of normality is investigated showing the relative robustness against non‐normality and a data transformation to control for normality. A case study is provided showing the relative exclusion power of all three models from an active commingled case within the Defense POW / MIA Accounting Agency. In total, 14,357,220 osteometric t ‐tests were conducted. The results indicate that osteometric sorting performs as expected despite reference samples deviating from normality. The two new models outperform the original, and one of those is recommended to supersede the original for future osteometric sorting work.

Lynch, Jeffrey James↗
NASA NTRS1978

Sorting on STAR

Timing comparisons are given for three sorting algorithms written for the CDC STAR computer. One algorithm is Hoare's (1962) Quicksort, which is the fastest or nearly the fastest sorting algorithm for most computers. A second algorithm is a vector version of Quicksort that takes advantage of the STAR's vector operations. The third algorithm is an adaptation of Batcher's (1968) sorting algorithm, which makes especially good use of vector operations but has a complexity of N(log N)-squared as compared with a complexity of N log N for the Quicksort algorithms. In spite of its worse complexity, Batcher's sorting algorithm is competitive with the serial version of Quicksort for vectors up to the largest that can be treated by STAR. Vector Quicksort outperforms the other two algorithms and is generally preferred. These results indicate that unusual instruction sets can introduce biases in program execution time that counter results predicted by worst-case asymptotic complexity analysis.

Stone, H. S.↗
NASA NTRS1987

Algorithm Sorts Groups Of Data

For efficient sorting, algorithm finds set containing minimum or maximum most significant data. Sets of data sorted as desired. Sorting process simplified by reduction of each multielement set of data to single representative number. First, each set of data expressed as polynomial with suitably chosen base, using elements of set as coefficients. Most significant element placed in term containing largest exponent. Base selected by examining range in value of data elements. Resulting series summed to yield single representative number. Numbers easily sorted, and each such number converted back to original set of data by successive division. Program written in BASIC.

Evans, J. D.↗
NASA NTRS2020

Using XRD to Characterize Sediment Sorting in a Mars Analog Glacio-Fluvio-Eolian Basaltic Sedimentary System in Iceland

The martian surface has a primarily basaltic composition and is dominated by sedimentary deposits. Ancient layered sedimentary rocks have been identified across the planet from orbit, have been studied in situ by the Mars Exploration Rovers and the Mars Science Laboratory rover, and will be studied by the Mars 2020 rover. These ancient sedimentary rocks were deposited in fluvial, lacustrine, and eolian environments during a warmer and wetter era on Mars. It is important to study the composition of sediments in Mars analog environments to characterize how minerals in basaltic sedimentary systems are sorted and/or aqueously altered. This information can help us better interpret sedimentary processes from similar deposits on Mars and derive information about the igneous source rocks. Sediment sorting has been studied extensively on Earth, but not typically in basaltic environments. Previous work has addressed sorting of basaltic sediments through experimental techniques and in modern eolian basaltic systems and aqueous alteration in subglacial and proglacial environments. We add to this body of research by studying sediment sorting and aqueous alteration in a glacio-fluvio-eolian basaltic system in southwest Iceland.

Rampe, E. B.↗
NASA NTRS2022

Galaxy Correlation Function and Local Density from Photometric Redshifts Using the Stochastic Order Redshift Technique (SORT)

The stochastic order redshift technique (SORT) is a simple, efficient, and robust method to improve cosmological redshift measurements. The method relies upon having a small (∼10 per cent) reference sample of high-quality redshifts. Within pencil- beam-like sub-volumes surrounding each galaxy, we use the precise dN/dz distribution of the reference sample to recover new redshifts and assign them one-to-one to galaxies such that the original rank order of redshifts is preserved. Preserving the rank order is motivated by the fact that random variables drawn from Gaussian probability density functions with different means but equal standard deviations satisfy stochastic ordering. This process is repeated for sub-volumes surrounding each galaxy in the survey. This results in every galaxy being assigned multiple ‘recovered’ redshifts from which a new redshift estimate is determined. An earlier paper applied SORT to a mock Sloan Digital Sky Survey at z 0.2 and accurately recovered the two-point correlation function (2PCF) on scales > 4 h−1Mpc. In this paper, we test the performance of SORT in surveys spanning the redshift range 0.75 < z < 2.25. We used two mock surveys extracted from the Small MultiDark–Planck and Bolshoi–Planck N-body simulations with dark matter haloes that were populated by the Santa Cruz semi-analytic model. We find that SORT overall improves redshift estimates, accurately recovers the redshift-space 2PCF ξ (s) on scales > 2.5 h−1Mpc, and provides improved local density estimates in regions of average or higher density, which may allow for improved understanding of how galaxy properties relate to their environments.

James Kakos↗
DOE OSTI2022

Multiple stage sorting

A material sorting system sorts materials utilizing multiple stages of classification and sorting, including a vision system that implements a machine learning system in order to identify or classify each of the materials, and Laser Induced Breakdown Spectroscopy to perform a subsequent classification and sorting of the remaining materials.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2024

Sorting between metal alloys

A material sorting system sorts materials utilizing an x-ray fluorescence and/or a vision system that implements a machine learning system in order to identify or classify each of the materials, which are then sorted into separate groups based on such an identification or classification determining that the materials are composed of either wrought aluminum, extruded aluminum, or cast aluminum. The system is capable of sorting between cast aluminum alloys and also between wrought aluminum alloys.

Kumar, Nalin↗
DOE OSTI2025

Sorting rare earth magnets motors for recycling without opening the motors

Abstract A novel approach for sorting electric motors without dismantling them is reported in this article. This approach increases the likelihood that a motor selected from a mixture for recycling would contain rare earth elements (REEs), which are pivotal for numerous advanced green technologies. The challenge of inadvertently dismantling motors without REEs during recycling is addressed by this proposed innovative method. It relies on cogging interactions and power density for sorting motors with REEs. The process uses an algorithm introduced in this work to sort motors in two steps by (a) distinguishing induction motors from permanent magnet motors, and (b) distinguishing motors with critical REEs (e.g., Nd, Pr, Dy, Tb) from ferrite-based motors, all without opening the motors. The former was accomplished with 100% accuracy while the latter was accomplished with ~ 78% accuracy. Such high accuracy improves the recycling efficiency of critical REEs from motors, alleviating concern about supply disruption and supporting resource conservation and sustainability.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Mammalian Chromosome Analysis and Sorting by Flow Cytometry

The analysis of chromosomes by flow cytometry is termed flow cytogenetics, and it involves the analysis and sorting of single mitotic chromosomes in suspension. The study of flow karyograms provides insight into chromosome number and structure to provide information on chromosomal DNA content and can enable the detection of deletions, translocations, or any forms of aneuploidy. Beyond its clinical applications, flow cytogenetics greatly contributed to the Human Genome Project through the ability to sort pure populations of chromosomes for gene mapping, cloning, and the construction of DNA libraries. Maximizing the potential of these important applications of flow cytogenetics relies on precise instrument setup and optimal sample processing, both of which impact the accuracy and quality of the data that are generated. This article is a compilation of the existing protocols that describe the stepwise methodology of accumulating, isolating, and staining metaphase chromosomes to prepare single-chromosome suspensions for flow cytometric analysis and sorting. Although the chromosome preparation protocols have remained largely unchanged, cytometer technology has advanced dramatically since these protocols were originally developed. Advances in cytometry technologies offer new and exciting approaches for understanding and monitoring chromosomal aberrations, but the hallmark of these protocols remains their simplicity in methodologies and reagent requirements and the accuracy of data resolvable to every chromosome of the cell.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2023

Impact of automated battery sorting for mineral recovery from lithium-ion battery recycling in the United States

The United States has identified several lithium-ion battery materials as critical for reaching the national emission reduction targets that have been set in accordance with the 2015 Paris Agreement. However, with few natural resources available domestically, there is a rapidly growing focus on the development of a domestic recycling industry to recover these materials from end-of-life batteries. Here, we use the Lithium-Ion Battery Resources Assessment (LIBRA) system dynamics model to evaluate the impact of automated battery sorting technology in terms of the shares of cobalt and nickel that are recovered through recycling. Findings show that automated sorting has clear benefits over manual sorting methods by helping recyclers selectively process high-cobalt batteries. By maximizing cobalt recovery, recycling becomes more profitable and drives greater investment in recycling capacity, resulting in a higher share of nickel and cobalt recovered from EOL batteries over time.

25 ENERGY STORAGE↗
DOE OSTI2017

Development of a new approach based on midwave infrared spectroscopy for post-consumer black plastic waste sorting in the recycling industry

Highlights: • MWIR reflectance contact measurements were performed on post-consumer waste. • MWIR absorptions are found to be potentially suitable for black plastic resin classification. • MWIR is also potentially suitable for separation of coloured plastic and wood based products. • Atmospheric transmittance simulations suggest feasibility of stand-off measurements. - Abstract: Waste sorting is key to the process of waste recycling. Exact identification of plastic resin and wood products using Near Infrared (NIR, 1–1.7 µm) sensing is currently in use. Yet, dark targets characterized by low reflectance, such as black plastics, are hard to identify by this method. Following the recent success of Midwave Infrared (MWIR, 3–12 µm) measurements to identify coloured plastic polymers, the aim of this study was to assess whether this technique is applicable to sorting black plastic polymers and wood products. We performed infrared reflectance contact measurements of 234 plastic samples and 29 samples of wood and paper products. Plastic samples included black, coloured and transparent Polyethylene Terephthalate (PET), Polyethylene (PE), Polyvinyl Chloride (PVC), Polypropylene (PP), Polylactic acid (PLA) and Polystyrene (PS). The spectral signatures of the black and coloured plastic samples were compared with clear plastic samples and signatures documented in the literature to identify the polymer spectral features in the presence of coloured material. This information was used to determine the spectral bands that best suit the sorting of black plastic polymers. The main NIR-MWIR absorption features of wood, cardboard and paper were identified as well according to the spectral measurements. Good agreement was found between our measurements and the absorption features documented in the literature. The new approach using MWIR spectral features appears to be useful for black plastics as it overcomes some of the limitations in the NIR region to identify them. The main limitation of this technique for industrial applications is the trade-off between the signal-to-noise ratio of the sensor operating in standoff mode and the speed at which waste is moved under the sensor. This limitation can be resolved by reducing the system’s spectral resolution to 16 cm{sup −1}, which allows for faster spectra acquisition while maintaining a reasonable signal-to-noise ratio.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2024

Self-Sorting vs Coassembly in Peptide Amphiphile Supramolecular Nanostructures

The functionality of supramolecular nanostructures can be expanded if systems containing multiple components are designed to either self-sort or mix into coassemblies. This is critical to gain the ability to craft self-assembling materials that integrate functions, and our understanding of this process is in its early stages. Here, in this work, we have utilized three different peptide amphiphiles with the capacity to form β-sheets within supramolecular nanostructures and found binary systems that self-sort and others that form coassemblies. This was measured using atomic force microscopy to reveal the nanoscale morphology of assemblies and confocal laser scanning microscopy to determine the distribution of fluorescently labeled monomers. We discovered that PA assemblies with opposite supramolecular chirality self-sorted into chemically distinct nanostructures. In contrast, the PA molecules that formed a mixture of right-handed, left-handed, and flat nanostructures on their own were able to coassemble with the other PA molecules. We attribute this phenomenon to the energy barrier associated with changing the handedness of a β-sheet twist in a coassembly of two different PA molecules. This observation could be useful for designing biomolecular nanostructures with dual bioactivity or interpenetrating networks of PA supramolecular assemblies.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗