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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
DOE OSTI2016

Microfluidic ultrasonic particle separators with engineered node locations and geometries

An ultrasonic microfluidic system includes a separation channel for conveying a sample fluid containing small particles and large particles, flowing substantially parallel, adjacent to a recovery fluid, with which it is in contact. An acoustic transducer produces an ultrasound standing wave, that generates a pressure field having at least one node of minimum pressure amplitude. An acoustic extension structure is located proximate to said separation channel for positioning said acoustic node off center in said acoustic area and concentrating the large particles in said recovery fluid stream.

42 ENGINEERING↗
DOE OSTI2019

Accurate Taylor transfer maps for large aperture iron dominated magnets used in charged particle separators and spectrometers

For high-resolution separators like the projected Super-FRS at FAIR, an adapted and accurate ion-optical model considering realistic $B$-dependent magnet parameters is crucial in achieving the desired parameters (e.g. resolution) and to enable a fast optimization. Starting from the magnetic field measurements and simulations, rigidity-dependent Taylor transfer maps are generated for the Super-FRS preseparator dipole magnets. The effects of the magnetic saturation in the steel yoke on the image aberrations are analyzed.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2016

Methods for separating particles and/or nucleic acids using isotachophoresis

According to one embodiment, a method includes co-feeding fluids comprising a leading electrolyte, a trailing electrolyte, and at least one of DNA and RNA to a channel, and applying an electric field to the fluids in a direction perpendicular to an axis of the channel for inducing transverse isotachophoresis. In another embodiment, a method includes co-feeding fluids to a channel. The fluids include a leading electrolyte, a trailing electrolyte, biological objects, at least one of DNA and RNA, and a spacer electrolyte having an electrophoretic mobility that is between an electrophoretic mobility of at least some of the biological objects and an electrophoretic mobility of the at least one of the DNA and the RNA. The method also includes applying an electric field to the fluids in a direction perpendicular to an axis of the channel for inducing transverse isotachophoresis. Other methods of isotachophoresis are disclosed in addition to these.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Efficient Mesofluidic Separation of Large Particles in nuclear slurries - 20408

Efficient and effective particle separation is essential to cleanup of many nuclear wastes. For example, particle separation may be used to accelerate settle-decant bottlenecks that limit the throughput necessary to achieve the U.S. Department of Energy waste cleanup mission in a timely manner. Particle separation may be used to protect downstream processing equipment from pulses of solids that may be encountered near (within a few feet of) liquid-solid interfaces during waste transfer operations, thereby preventing work stoppages. Effective particle separation may permit efficient sludge washing. These are only a few of the ways in which particle separation is important. Yet, efficient and effective particle separation in nuclear processing environments remains challenging. For example, settle-decant operations permit larger and heavier particles to settle, leaving smaller, lighter particles suspended. However, settle-decant operations are slow, convection currents may resuspend solids, hindered settling of multicomponent slurries remains incompletely understood, and predictive models for settling in graduated cylinders fail to match limited observations of settling in large waste tanks. Additionally, pumping operations can cause turbulent resuspension of particles when the pump intake is close to the settled solids layer. Filtration techniques that use membranes or partially permeable barriers retain larger particles, permitting smaller particles to permeate. However, filters, including dead-end filtration, are prone to clogging and caking, operate at elevated pressures due to minimal void volume, and increase in pressure during operations, which require more control systems. Therefore, the need for high throughput particle separation techniques that operate with modest pressure drops persists. A novel mesofluidic separator presents the opportunity to effectively and efficiently accelerate the waste cleanup mission. The separator separates large particles from process streams across a broad range of particle sizes and has no moving parts or media to replace, regenerate, or clean. This separator design has an unusually large void volume, permitting operation at much higher flow rates (and lower pressures) than traditional filtration (e.g., dead-end filtration). Industrial-scale flow rates have been demonstrated. In performance testing, mesofluidic separators operate at might flow rates (>90 gpm (0.0006 m{sup 3}/s) in piping 3 inches (0.08 m) in diameter; Re>10{sup 5}), with modest pressure drop (∼25 psi (170 KPa) in testing). In complex, aggregating waste simulants, the separator loses <25% of flow projected over months without back pulsing or chemical cleaning. Mesofluidic separation presents infrastructure advantages, reduces risk, and provides mission impact. Infrastructure advantages include implementation within existing transfer systems, plug and play without facility modifications to safety systems, and operation at low pressures. The separator is flexible in location, may be positioned within or outside of waste tanks, and may replace or augment dead-end and cross-flow filters. Mesofluidic separation reduces risk by minimizing waste (no media to replace or regenerate and no cleaning chemicals to handle and dispose) and by minimizing filter change-out consistent with as low as reasonably achievable (ALARA) exposure to workers. The potential mission impact of these separators is substantial. The separator has potential to support, simplify, and accelerate in-farm transfers and waste feed delivery. Furthermore, the separator can free up settling and holding tanks in the Direct Feed Low-Activity Waste (DFLAW) mission by reducing or eliminating post-transfer settling and wait times with the potential to free up 1 Mgal (4000 m{sup 3}) of double-shell tank space. This paper quantitatively compares mesofluidic separation to dead-end filtration, discusses scale-up results, and considers the separator's potential to efficiently and effectively reduce the long-term environmental ability of particulate-rich nuclear wastes. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2013

Classification of Volatile Engine Particles

Volatile particles cannot be detected at the engine exhaust by an aerosol detector. They are formed when the exhaust is mixed with ambient air downstream. Lack of a precise definition of volatile engine particles has been an impediment to engine manufacturers and regulatory agencies involved in the development of an effective control strategy. It is beyond doubt that volatile particles from combustion sources contribute to the atmospheric particulate burden, and the effect of that contribution is a critical issue in the ongoing research in the areas of air quality and climate change. A new instrument, called volatile particle separator (VPS), has been developed. It utilizes a proprietary microporous metallic membrane to separate particles from vapors. VPS data were used in the development of a two-parameter function to quantitatively classify, for the first time, the volatilization behavior of engine particles. The value of parameter A describes the volatilization potential of an aerosol. A nonvolatile particle has a larger A-value than a volatile one. The value of parameter k, an effective evaporation energy barrier, is found to be much smaller for small engine particles than that for large engine particles. The VPS instrument provides a means beyond just being a volatile particle remover; it enables a numerical definition to characterize volatile engine particles.

Engine emission↗
DOE OSTI2015

A microfluidic platform for precision small-volume sample processing and its use to size separate biological particles with an acoustic microdevice [Precision size separation of biological particles in small-volume samples by an acoustic microfluidic system]

Here, a major advantage of microfluidic devices is the ability to manipulate small sample volumes, thus reducing reagent waste and preserving precious sample. However, to achieve robust sample manipulation it is necessary to address device integration with the macroscale environment. To realize repeatable, sensitive particle separation with microfluidic devices, this protocol presents a complete automated and integrated microfluidic platform that enables precise processing of 0.15–1.5 ml samples using microfluidic devices. Important aspects of this system include modular device layout and robust fixtures resulting in reliable and flexible world to chip connections, and fully-automated fluid handling which accomplishes closed-loop sample collection, system cleaning and priming steps to ensure repeatable operation. Different microfluidic devices can be used interchangeably with this architecture. Here we incorporate an acoustofluidic device, detail its characterization, performance optimization, and demonstrate its use for size-separation of biological samples. By using real-time feedback during separation experiments, sample collection is optimized to conserve and concentrate sample. Although requiring the integration of multiple pieces of equipment, advantages of this architecture include the ability to process unknown samples with no additional system optimization, ease of device replacement, and precise, robust sample processing.

42 ENGINEERING↗
DOE OSTI2012

Air cooled turbine component having an internal filtration system

A centrifugal particle separator is provided for removing particles such as microscopic dirt or dust particles from the compressed cooling air prior to reaching and cooling the turbine blades or turbine vanes of a turbine engine. The centrifugal particle separator structure has a substantially cylindrical body with an inlet arranged on a periphery of the substantially cylindrical body. Cooling air enters centrifugal particle separator through the separator inlet port having a linear velocity. When the cooling air impinges the substantially cylindrical body, the linear velocity is transformed into a rotational velocity, separating microscopic particles from the cooling air. Microscopic dust particles exit the centrifugal particle separator through a conical outlet and returned to a working medium.

42 ENGINEERING↗
DOE OSTI2023

Gravitational vortex disruption in mesofluidic separators

Typically, bump array devices separate submicrometer particles where gravitational effects remain small. However, as particle size increases from a few micrometers to hundreds of micrometers, gravitational effects become important and settling may induce vortex formation. Here, this article shows under laminar flow that these vortices suffice to disrupt flow fields, frustrating particle separation. The limiting diameter, above which vortices do form, is determined, and the dependence of the limiting diameter on viscosity, particle properties, and separator orientation is quantified.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2014

Electric current-driven migration of electrically neutral particles in liquids

We design and experimentally demonstrate a migration of electrically neutral particles in liquids driven by electric current according to the discrepancies of their electrical conductivities. A force from electric current to electrically neutral particles has been identified to drive the particles toward the lateral surface from the centre of suspension via three distinguishable zones, namely, pushing, trapping, and expelling zones. The driving force can overtake gravity in practical cases. The property of the force is found neither similar to that of the force in electromagnetophoresis nor similar to that of the electromigration force in terms of direction and magnitude. An expression for the force at the pushing zone has been developed based on the numerical calculation of the thermodynamics of suspension fluids. The excellent agreement between numerical calculations and experimental data demonstrates that our calculation provides fundamental and predictive insight into particles separation from the liquids. Therefore, it is possible to use the force in many engineering applications such as separation of particles according to the differences of their electrical conductivities.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2018

The Flotation Chemistry of Nonsulfide Minerals

Particulate separations are of considerable significance in many areas of technology ranging from pharmaceutics and microelectronics, to mining and construction materials industries. In addition, particulate separation technology is of critical importance in the environmental area, for example, the development of advanced water treatment processes for the 21st century will rely on more efficient particulate separation techniques. In this regard it is most appropriate that the Separations Program of the Division of Chemical Sciences, Geosciences, and Biosciences, Office of Basic Energy Sciences, of DOE supports basic science research in the area of particulate separations. One such particulate separation process of special importance is froth flotation, a physico-chemical process that is used to separate particles in an aqueous suspension via differences in hydrophobicity as established by the interaction of various reagents at the solid/water, solid/gas and water/gas interfaces. Surfactants, called collectors, are added to a suspension to selectively adsorb at the surface of specific particles, rendering these particles hydrophobic. Regulators are employed to promote collector adsorption at the desired surfaces, while preventing such reactions at other surfaces. When air is dispersed into the suspension, the bubbles generated attach to the hydrophobic particles. The resulting bubble/particle aggregates float to the suspension surface and are collected in a froth phase as a concentrate. The remaining hydrophilic particles are retained in suspension and discharged as a tailings product. Clearly, particulate separation by froth flotation is an outstanding example of applied surface chemistry, and is used in the food, petroleum, pulp/paper, and mineral industries. The use of flotation technology is perhaps most significant in the mineral industry where, in the U. S. alone, over 500,000 tons/day of nonsulfide minerals are processed. The estimated value of all nonfuel mineral materials processed in the United States during 2015 totaled $630 billion. It is evident that particle separation by flotation is an important process that is used in many of the mineral industries. Understanding of the interfacial chemistry for the development of improved flotation separations is required for more effective production and utilization of our mineral resources, especially the critical minerals as identified in the 2017 USGS report, “Critical Mineral Resources of the United States – Economic and Environmental Geology and Prospects for Future Supply.” In this regard, a research program has been in progress with DOE support from Grant DE-FGO2-93ER14315 to study the fundamental interfacial chemistry features in nonsulfide mineral flotation systems in order to increase our understanding and provide for improved separation efficiencies and energy economy in the processing of our mineral resources. Significant contributions have been made to the flotation chemistry of flotation separations in many areas, including, salt minerals; collector adsorption; wetting, surface forces, bubble attachment; interfacial water structure; phyllosilicate minerals, and critical mineral resources such as rare earth minerals and lithium resources. The research results summarized herein have resulted in more than 225 publications, the education of 28 PhD graduate students, and impressive recognition with university, national, and international awards. For example, among many other awards, Distinguished Professor Jan Miller, PI, was elected to be a member of the National Academy of Engineering (1993) and the National Academy of Inventors (2014). In 2015 he received the University of Utah’s most prestigious award presented annually to a faculty member, the Rosenblatt Prize for Excellence. Research Professor Xuming Wang was selected by SME to be a Henry Krumb Lecturer (2013-2014), and many of the student researchers involved in the program received national awards from AIME, ICE, IPMI, SME, and TMS. It is evident that the flotation separation research program has been quite successful. Unfortunately, the flotation chemistry research for mineral particle separation has been terminated even though the renewal proposal received excellent reviews with recommended funding. The need for continued support of minerals separation research is of critical importance as recognized by 1) the recent 2017 USGS report, “Critical Mineral Resources of the United States – Economic and Environmental Geology and Prospects for Future Supply,” and by 2) the 20 December 2017 executive order from President Trump to increase the discovery, production, and domestic refining of critical minerals. In view of our research accomplishments, the excellent reviews of the renewal proposal, and the expressed need for attention to the production of critical minerals, termination of “The Flotation Chemistry of Nonsulfide Minerals” research program by DOE is not appropriate, and continued support should be reconsidered.

58 GEOSCIENCES↗
DOE OSTI2019

Interplay between Short and Long-Ranged Forces Leading to the Formation of Ag Nanoparticle Superlattice

Nanoparticle (NP) superlattices have attracted increasing attention due to their unique properties. However, key questions remain for predicting the nanoparticle behavior from interparticle forces, especially the role of hydration force (Fhyd) and its correlation to other forces, regarding the transient and final superlattice configurations. Here we investigated the self-assembly of Ag NPs in aqueous solution by employing in situ liquid cell transmission electron microscopy, combined with atomic force microscopy based force measurements and theoretical calculations. In spite of instantaneous Brownian motion of NPs, a correlation between velocity and van der Waals force (FvdW) on average was observed during the later self-assembly process. In the post-assembly state, a delicate balance between Fhyd and FvdW gives rise to ~ 0.6~0.9 nm separation be-tween NPs in the superlattice. Our study demonstrates pivotal roles of interparticle forces, enabling the control of the separation which is critical for tailoring the properties of superlattices.

Lee, Jaewon↗
DOE OSTI2025

Bayesian model mixing with multireference energy density functional

Reliably predicting nuclear properties across the entire chart of isotopes is important for applications ranging from nuclear astrophysics to superheavy science to nuclear technology. To this day, however, all the theoretical models that can scale at the level of the chart of isotopes remain semiphenomenological. Because they are fitted locally, their predictive power can vary significantly; different versions of the same theory provide different predictions. Bayesian model mixing takes advantage of such imperfect models to build a local mixture of a set of models to make improved predictions. Earlier attempts to use Bayesian model mixing for mass table calculations relied on models treated at single-reference energy density functional level, which fail to capture some of the correlations caused by configuration mixing or the restoration of broken symmetries. In this study we have applied Bayesian model mixing techniques within a multireference energy density functional (MR-EDF) framework. We considered predictions of two-particle separation energies from particle number projection or angular momentum projection with four different energy density functionals—a total of eight different MR-EDF models. We used a hierarchical Bayesian stacking framework with a Dirichlet prior distribution over weights together with an inverse log-ratio transform to enable positive correlations between different models. We found that Bayesian model mixing provides significantly improved predictions compared to the participating models. Published by the American Physical Society 2025

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2012

Science Goals for the ARM Recovery Act Radars

Science Goals for the ARM Recovery Act Radars. In October 2008, an ARM workshop brought together approximately 30 climate research scientists to discuss the Atmospheric Radiation Measurement (ARM) Climate Research Facility's role in solving outstanding climate science issues. Through this discussion it was noted that one of ARM's primary contributions is to provide detailed information about cloud profiles and their impact on radiative fluxes. This work supports cloud parameterization development and improved understanding of cloud processes necessary for that development. A critical part of this work is measuring microphysical properties (cloud ice and liquid water content, cloud particle sizes, shapes, and distribution). ARM measurements and research have long included an emphasis on obtaining the best possible microphysical parameters with the available instrumentation. At the time of the workshop, this research was reaching the point where additional reduction in uncertainties in these critical parameters required new instrumentation for applications such as specifying radiative heating profiles, measuring vertical velocities, and studying the convective triggering and evolution of three-dimensional (3D) cloud fields. ARM was already operating a subset of the necessary instrumentation to make some progress on these problems; each of the ARM sites included (and still includes) a cloud radar (operating at 35 or 94 GHz), a cloud lidar, and balloon-borne temperature and humidity sensors. However, these measurements were inadequate for determining detailed microphysical properties in most cases. Additional instrumentation needed to improve retrievals of microphysical processes includes radars at two additional frequencies for a total of three at a single site (35 GHz, 94 GHz, and a precipitation radar) and a Doppler lidar. Evolving to a multi-frequency scanning radar is a medium-term goal to bridge our understanding of two-dimensional (2D) retrievals to the 3D cloud field. These additional microphysical measurements would allow detailed cloud properties to be derived even in the presence of light precipitation. It is important to couple these detailed measurements of cloud microphysics to vertical motion on the cloud scale to couple microphysics with meteorological processes. Vertically pointing Doppler radars provide the vertical motion of cloud particles but, to separate particle motion from air motion, a wind profiler is required. The American Recovery and Reinvestment Act provided the means to address these needs and implement a multi-frequency suite of radars, including scanning radars, at each of the ARM sites. In addition, Doppler lidars have been deployed at several sites. With these new measurement capabilities, ARM has the measurement capabilities to tackle the problems of improving microphysical profile descriptions and evaluating the relationship between our current narrow-field-of view, zenith perspective on clouds to a description of the full 3D cloud field and its temporal evolution.

54 ENVIRONMENTAL SCIENCES↗