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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 955 records · Page 53
All sourcesNASA NTRSDOE OSTI
NASA NTRS1994

Microphone Corrections for Accurate In-Flow Acoustic Measurements at High Frequency

Acoustic analysis of aircraft components through small-scale experiments in wind tunnels requires in-flow acoustic measurements at high frequencies. This high frequency information is shifted to lower frequencies during the geometric scaling process. As a result, models of scale one tenth and smaller require frequency information of up to at least 100 kHz to resolve the midpoint of the full-scale equivalent audible range. Farfield acoustic measurements of frequencies higher than 100 kHz are prohibitively difficult to make due to the physical limitations of atmospheric propagation over large distances and the delicacy of the required instruments. Even measurements up to 100 kHz require special corrections and calibration procedures to maintain sufficient accuracy. In-flow microphone measurements at high frequencies require additional consideration due to the presence of the aerodynamic microphone forebody which protects the microphone diaphragm from flow impingement. The screen located at the forebody surface attenuates the high frequency acoustic waves and must be accounted for. The purpose of this paper is to present procedures for calibrating and correcting high frequency acoustic measurements to retain high accuracy. Specifically, this paper gives calibration procedures and examples of typical data for calibrating or correcting for five physical effects. These effects include the frequency response of the entire acoustic data acquisition system, intrusion of the microphone into the acoustic field, forebody screen attenuation, directionality of microphone forebody response and atmospheric absorption.

Allen, Christopher S.↗
NASA NTRS2009

Continuous-Flow System Produces Medical-Grade Water

A continuous-flow system utilizes microwave heating to sterilize water and to thermally inactivate endotoxins produced in the sterilization process. The system is designed for use in converting potable water to medical-grade water. Systems like this one could be used for efficient, small-scale production of medical- grade water in laboratories, clinics, and hospitals. This system could be adapted to use in selective sterilization of connections in ultra-pure-water-producing equipment and other equipment into which intrusion by microorganisms cannot be tolerated. Lightweight, port - able systems based on the design of this system could be rapidly deployed to remote locations (e.g., military field hospitals) or in response to emergencies in which the normal infrastructure for providing medical-grade water is disrupted. Larger systems based on the design of this system could be useful for industrial production of medical-grade water. The basic microwave-heating principle of this system is the same as that of a microwave oven: An item to be heated, made of a lossy dielectric material (in this case, flowing water) is irradiated with microwaves in a multimode microwave cavity. The heating is rapid and efficient because it results from absorption of microwave power throughout the volume of the lossy dielectric material. In this system, a copper tube having a length of 49.5 cm and a diameter of 2.25 cm serves as both the microwave cavity and the sterilization chamber. Microwave power is fed via a coaxial cable to an antenna mounted inside the tube at mid-length (see figure). Efficient power transfer occurs due to the shift in wavelength associated with the high permittivity of water combined with the strong coupling of 2.45-GHz microwaves with rotational-vibrational transitions of the dipolar water molecule.

Akse, James R.↗
NASA NTRS2011

Nature's Way of Making Audacious Space Projects Viable

Building a starship within the next 100 years is an audacious goal. To be successful, we need sustained funding that may be difficult to maintain in the face of economic challenges that are poised to arise during these next 100 years. Our species' civilization has only recently reached the classification as (approximately) Type-I on the Kardashev scale; that is, we have spread out from one small locality to become a global species mastering the energy and resources of an entire planet. In the process we discovered the profound truth that the two-dimensional surface of our world is not flat, but has positive curvature and is closed so that its area and resources are finite. It should come as no surprise to a Type I civilization when its planet's resources dWindle; how could they not? Yet we have gone year by year, government by government, making little investment for the time when civilization becomes violent in the unwelcome contractions that must follow, when we are forced too late into the inevitable choice: to remain and diminish on an unhappy world; or to expand into the only dimension remaining perpendicularly outward from the surface into space. Then some day we may become a Type-II civilization, mastering the resources of an entire solar system. Our species cannot continue as we have on this planet for another 100 years. Doubtless it falls on us today, the very time we intended to start building a starship, to make the late choice. We wished this century to be filled with enlightenment and adventure; it could be an age of desperation and war. What a time to begin an audacious project in space! How will we maintain consistent funding for the next 100 years? Fortunately, saving a civilization, mastering a solar system, and doing other great things like building starships amount to mostly the same set of tasks. Recognizing what we must be about during the next 100 years will make it possible to do them all.

Metzger, Philip T.↗
NASA NTRS2014

Combinatorial Multidomain Mesoporous Chips and a Method for Fractionation, Stabilization, and Storage of Biomolecules

A new fractionation device shows desirable features for exploratory screening and biomarker discovery. The constituent MSCs may be tailored for desired pore sizes and surface properties and for the sequestration and enrichment of extremely low abundant protein and peptides in desired ranges of the mass/charge spectrum. The MSCs are effective in yielding reproducible extracts from complex biological samples as small as 10 microliter in a time as short as 30 minutes. They are inexpensive to manufacture, and allow for scaled up production to attain the simultaneous processing of a large number of samples. The MSCs are multiplexed, label-free diagnostic tools with the potential of biological recognition moiety modification for enhanced specificity. The MSCs may store, protect and stabilize biological fluids, enabling the simplified and cost-effective collection and transportation of clinical samples. The MSC-based device may serve as a diagnostic tool to complement histopathology, imaging, and other conventional clinical techniques. The MSCs mediated identification of disease-specific protein signatures may help in the selection of personalized therapeutic combinations, in the real-time assessment of therapeutic efficacy and toxicity, and in the rational modulation of therapy based on the changes in the protein networks associated with the prognosis and the drug resistance of the disease.

Ferrari, Mauro↗
DOE OSTI2011

TESTING OF THE SECOND GENERATION SPINTEK ROTARY FILTER -11357

The SpinTek rotary microfilter has been developed under the Department of Energy (DOE) Office of Environmental Management (EM) for the purpose of deployment in radioactive service in the DOE complex. The unit that was fabricated and tested is the second generation of the filter that incorporates recommended improvements from previous testing. The completion of this test satisfied a key milestone for the EM technology development program and technology readiness for deployment by Savannah River Remediation in the Small Column Ion Exchange and Sludge Washing processes at the Savannah River Site (SRS). The Savannah River National Laboratory (SRNL) contracted SpinTek Filtration to fabricate a full scale 25 disk rotary filter and perform a 1000 hour endurance test with a simulated SRS sludge. Over 1500 hours of operation have been completed with the filter. SpinTek Filtration fabricated a prototypic 25 disk rotary filter including updates to manufacturing tolerances, an updated design to the rotary joint, improved cooling to the bottom journal, decreases in disk and filter shaft hydraulic resistances. The filter disks were fabricated with 0.5 {micro} pore size, sintered-metal filter media manufactured by Pall Corporation (M050). After fabrication was complete, the filter passed acceptance tests demonstrating rejection of solids and clean water flux with a 50% improvement over the previous filters. Once the acceptance test was complete, a 1000 hour endurance test was initiated simulating a sludge washing process. The test used a simulated SRS Sludge Batch 6 recipe. The insoluble solids started at 5 wt% and were raised to 10 and 15 wt% insoluble solids to simulate the concentration of a large volume tank. The filter system was automated and set up for 24 hour unattended operation. To facilitate this, process control logic was written to operate the filter. During the development it was demonstrated that the method of starting and stopping the filter can affect the build up of filter cake on the disks and therefore the performance of the filter. The filter performed well with the simulant. Very little drop in production was noticed between the 5 and 10 wt% insoluble solids feed. Increasing to 15 wt% had a more pronounced impact due to the rheology of the feed. Acid cleaning was used to clean the filter disks in-situ and restore filtration rate to almost 90% of the initial clean disk rate. Eighty liters of 0.2 M nitric acid in conjunction with water rinses were used to clean the filter in less than 2 hours. Filter testing was completed after 1000 hours of operation were performed on the final filter assembly configuration. The total run time for the testing was over 1500 hours. At the end of the test, the sludge washing was performed successfully from approximately 5.6 M to less than 1 M sodium.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2016

Development and Scale-Up of Copper-Based Chemical Looping with Oxygen Uncoupling

The University of Utah has been researching chemical looping with oxygen uncoupling of coal since 2007, focusing on copper-based carriers and a system configuration based on two interconnected circulating fluidized bed reactors. R&D has combined fundamental, lab-scale systems with operation of CLOU reactor systems at various scales and computational simulations for performance evaluation and reactor scale-up. Development has progressed from small lab scale through bench scale with a 10 kW dual bed research reactor to semi-pilot scale with a recently-inaugurated 220 kW chemical looping combustion process development unit. One of the challenges of scaling up copper-based CLOU technology is acquiring enough oxygen carrier material to support operation in larger reactor systems. The UofU CLC PDU, for example, requires 150-200 kg of inventory, so the oxygen carrier must be readily available in large quantities at comparatively low cost. Because no supplier capable of delivering 1+ tons of copper-based oxygen carrier material could be identified, an inexpensive oxygen carrier material was developed in-house and the carrier production process was scaled to produce large quantities of material sufficient for the CLC PDU. This presentation describes development of the CLOU process at the University of Utah, including evaluation of fundamental processes key to performance of CLOU, modeling and scale-up of the process, large-scale production of copper based oxygen carrier material and experience to date with the world’s largest dedicated CLOU reactor.

Whitty, Kevin J.↗
DOE OSTI2017

Electrochemical Membrane for Carbon Dioxide Capture and Power Generation

FuelCell Energy, Inc. (FCE), in collaboration with AECOM Corporation (formerly URS Corporation) and Pacific Northwest National Laboratory, has been developing a novel Combined Electric Power and Carbon-dioxide Separation (CEPACS) system. The CEPACS system is based on electrochemical membrane (ECM) technology derived from FCE’s carbonate fuel cell products featuring internal (methane steam) reforming and carrying the trade name of Direct FuelCell®. The unique chemistry of carbonate fuel cells offers an innovative approach for separation of CO 2 from existing fossil-fuel power plant exhaust streams (flue gases). The ECM-based CEPACS system has the potential to become a transformational CO 2 -separation technology by working as two devices in one: it separates the CO 2 from the exhaust of other plants such as an existing coal-fired plant and simultaneously produces clean electric power at high efficiency using a supplementary fuel. The development effort was carried out under the U.S. Department of Energy (DOE) cooperative agreement DE-FE0007634. The overall objective of this project was to successfully demonstrate the ability of FCE’s ECM-based CEPACS system technology to separate ≥90% of the CO 2 from a simulated Pulverized Coal (PC) power plant flue gas stream and to compress the captured CO2 to a state that can be easily transported for sequestration or beneficial use. In addition, a key objective was to show, through the technical and economic feasibility study and bench scale testing, that the ECM-based CEPACS system is an economical alternative for CO 2 capture in PC power plants, and that it meets DOE’s objective related to the incremental cost of electricity (COE) for post-combustion CO 2 capture (no more than 35% increase in COE). The project was performed in three budget periods (BP). The specific objective for BP1 was to complete the Preliminary Technical and Economic Feasibility Study. The T&EF study was based on the carbon capture system size suitable for a reference 550 MW PC power plant. The specific objectives for BP2 were to perform (flue gas) contaminant effect evaluation tests, small area membrane tests using clean simulated flue gas, design a flue gas pretreatment system for processing of the gas feed to ECM, update the Technical & Economic Feasibility Study (T&EFS) incorporating results of contaminant effect tests and small area membrane tests, and to prepare a test facility for bench scale testing. The specific objectives for BP3 were to perform bench scale testing (parametric and long-duration testing) of a 11.7 m 2 ECM-based CO 2 capture, purification and compression system, and update (as final) the Technical and Economic Feasibility Study. In addition, an Environmental Health and Safety evaluation (assessment) of the ECM technology was included. This final technical report presents the progress made under the project.

20 FOSSIL-FUELED POWER PLANTS↗
DOE OSTI2021

Baryonic effects in the Effective Field Theory of Large-Scale Structure and an analytic recipe for lensing in CMB-S4

Upcoming Large-Scale Structure surveys will likely become the next leading sources of cosmological information, making it crucial to have a precise understanding of the influence of baryons on cosmological observables. The Effective Field Theory of Large-Scale Structure (EFTofLSS) provides a consistent way to predict the clustering of dark matter and baryons on large scales, where their leading corrections in perturbation theory are given by a simple and calculable functional form even after the onset of baryonic processes. In this paper, we extend the two-fluid-like system up to two-loop order in perturbation theory. Along the way, we show that a new linear counterterm proportional to the relative velocity of the fluids could generically be present, but we show that its effects are expected to be small in our universe. Regardless, we show how to consistently perform perturbation theory in the presence of this new term. We find that the EFTofLSS at two-loop order can accurately account for the details of baryonic processes on large scales. Additionally, we compare our results to a hydrodynamical N-body simulation at many redshifts and find that the counterterms associated with the leading corrections to dark matter and baryons start to differ between redshifts z ≈ 3 and z ≈ 2, signaling the onset of star-formation physics. We then use these fits to compute the lensing power spectrum, show that the understanding of baryonic processes will be important for analyzing CMB-S4 data, and show that the two-loop EFTofLSS accurately captures these effects for ℓ ≲ 2000. Our results are also potentially of interest for current and future weak lensing surveys.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2015

Nanofiltration across Defect-Sealed Nanoporous Monolayer Graphene

Monolayer nanoporous graphene represents an ideal membrane for molecular separations, but its practical realization is impeded by leakage through defects in the ultrathin graphene. Here, we report a multiscale leakage-sealing process that exploits the nonpolar nature and impermeability of pristine graphene to selectively block defects, resulting in a centimeter-scale membrane that can separate two fluid reservoirs by an atomically thin layer of graphene. After introducing subnanometer pores in graphene, the membrane exhibited rejection of multivalent ions and small molecules and water flux consistent with prior molecular dynamics simulations. The results indicate the feasibility of constructing defect-tolerant monolayer graphene membranes for nanofiltration, desalination, and other separation processes.

77 NANOSCIENCE AND NANOTECHNOLOGY↗
NASA NTRS2002

The cold land processes experiment (CLPX) local scale observatin site (LSOS)

The Local Scale Observation Site (LSOS) is the smallest study site of the Cold LandProcesses Experiment (CLPX) and is located within the Fraser Meso-cell Study Area (MSA), near the Fraser Experimental Forest Headquarters Facility, in Fraser, CO USA.The 100-m x 100-m site consists of a small open field, a managed dense canopy and an open, mixed age canopy. Unlike the other components of the experiment, which focus on spatial distributions at relatively brief snapshots in time, measurements at the local scale site focused on the temporal domain.

cold land processes ground-based remote sensing va↗
DOE OSTI2024

Dark matter isocurvature from curvature

Isocurvature fluctuations, where the relative number density of particle species spatially varies, can be generated from initially adiabatic, or curvature, fluctuations if the various species fall out of or were never in thermal equilibrium. The freezing of the thermal relic dark matter abundance is one such case, but for modes that are still outside the horizon the amplitude is highly suppressed and originates from the small change in the local expansion rate due to the local space curvature produced by the curvature fluctuation. We establish a simple separate-universe method for calculating this generation that applies to both freeze-in and freeze-out models, identify three critical epochs for this process, and give general scaling behaviors for the amplitude in each case: the freezing epoch, the kinetic decoupling epoch and matter-radiation equality. Freeze-out models are typically dominated by spatially modulated annihilation from the latter epochs and can generate much larger isocurvature fluctuations compared with typical freeze-in models, albeit still very small and observationally allowed by cosmic microwave background measurements. Here, we illustrate these results with concrete models where the dark matter interactions are vector or scalar mediated.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2017

Slipstream pilot-scale demonstration of a novel amine-based post-combustion technology for carbon dioxide capture from coal-fired power plant flue gas

Post-combustion CO 2 capture (PCC) technology offers flexibility to treat the flue gas from both existing and new coal-fired power plants and can be applied to treat all or a portion of the flue gas. Solvent-based technologies are today the leading option for PCC from commercial coal-fired power plants as they have been applied in large-scale in other applications. Linde and BASF have been working together to develop and further improve a PCC process incorporating BASF’s novel aqueous amine-based solvent technology. This technology offers significant benefits compared to other solvent-based processes as it aims to reduce the regeneration energy requirements using novel solvents that are very stable under the coal-fired power plant feed gas conditions. BASF has developed the desired solvent based on the evaluation of a large number of candidates. In addition, long-term small pilot-scale testing of the BASF solvent has been performed on a lignite-fired flue gas. In coordination with BASF, Linde has evaluated a number of options for capital cost reduction in large engineered systems for solvent-based PCC technology. This report provides a summary of the work performed and results from a project supported by the US DOE (DE-FE0007453) for the pilot-scale demonstration of a Linde-BASF PCC technology using coal-fired power plant flue gas at a 1-1.5 MWe scale in Wilsonville, AL at the National Carbon Capture Center (NCCC). Following a project kick-off meeting in November 2011 and the conclusion of pilot plant design and engineering in February 2013, mechanical completion of the pilot plant was achieved in July 2014, and final commissioning activities were completed to enable start-up of operations in January 2015. Parametric tests were performed from January to December 2015 to determine optimal test conditions and evaluate process performance over a variety of operation parameters. A long-duration 1500-hour continuous test campaign was performed from May to August 2016 at a selected process condition to evaluate process performance and solvent stability over a longer period similar to how the process would operate as a continuously running large-scale PCC plant. The pilot plant integrated a number of unique features of the Linde-BASF technology aimed at lowering overall energy consumption and capital costs. During the overall test period including startup, parametric testing and long-duration testing, the pilot plant was operated for a total of 6,764 hours out of which testing with flue gas was performed for 4,109 hours. The pilot plant testing demonstrated all of the performance targets including CO 2 capture rate exceeding 90%, CO 2 purity exceeding 99.9 mol% (dry), flue gas processing capacity up to 15,500 lbs/hr (equivalent to 1.5 MWe capacity slipstream), regeneration energy as low as 2.7 GJ/tonne CO 2 , and regenerator operating pressure up to 3.4 bara. Excellent solvent stability performance data was measured and verified by Linde and BASF during both test campaigns. In addition to process data, significant operational learnings were gained from pilot tests that will contribute greatly to the commercial success of PCC. Based on a thorough techno-economic assessment (TEA) of the Linde-BASF PCC process integrated with a 550 MWe supercritical coal-fired power plant, the net efficiency of the integrated power plant with CO 2 capture is increased from 28.4% with the DOE/NETL Case 12 reference to 30.9% with the Linde-BASF PCC plant previously presented utilizing the BASF OASE® blue solvent [Ref. 4], and is further increased to 31.4% using a Linde-BASF PCC plant with BASF OASE® blue solvent and an advanced stripper interstage heater (SIH) configuration. The Linde-BASF PCC plant incorporating the BASF OASE® blue solvent also results in significantly lower overall capital costs, thereby reducing the cost of electricity (COE) and cost of CO 2 captured from $147.25/MWh and $56.49/MT CO 2 , respectively, for the reference DOE/NETL Case 12 plant, to $128.49/MWh and $41.85/MT CO2 for process case LB1, respectively, and $126.65/MWh and $40.66/MT CO 2 for process case SIH, respectively. With additional innovative Linde-BASF PCC process configuration improvements, the COE and cost of CO 2 captured can be further reduced to $125.51/MWh and $39.90/MT CO 2 for a further optimized PCC process defined as LB1-CREB. Most notably, the Linde-BASF process options assessed have already demonstrated the potential to lower the cost of CO 2 captured below the DOE target of $40/MT CO 2 at the 550 MWe scale for second generation PCC technologies. Project organization, structure, goals, tasks, accomplishments, process criteria and milestones will be presented in this report along with highlights and key results from parametric and long-duration testing of the Linde-BASF PCC pilot. The parametric and long-duration testing campaigns were aimed at validating the performance of the PCC technology against targets determined from a preliminary techno-economic assessment. The stability of the solvent with extended operation in a realistic power plant setting was measured with performance verified. Additionally, general solvent classification information, process operating conditions, normalized solvent performance data, solvent stability test results, flue gas conditions data, CO 2 purity data in the gaseous product stream, steam requirements and process flow diagrams, and updated process economic data for a scaled-up 550 MWe supercritical power plant with CO 2 capture are presented and discussed in this report.

20 FOSSIL-FUELED POWER PLANTS↗
DOE OSTI2016

Development and Demonstration of Large-Scale Metal Additive Manufacturing for Military Vehicle Applications (Final Report)

Additive Manufacturing (AM) is a process by which complex parts can be manufactured directly from a basic feedstock without the need for tooling. From a defense perspective, this will enable direct manufacture of parts for legacy equipment. However, current AM technologies are limited to small part sizes (approximately 1 cubic foot), slow production rates (approximately 1 cubic inch per hour) and expensive feedstocks (approximately $100/lb). The objective of this project was to explore the impact large-scale, high production rate additive manufacturing can have on military applications. First, the program explored the use of existing composite large-scale (Big Area Additive Manufacturing – BAAM) systems for both tooling and direct part replacement with the use of the Army’s Low Velocity Airdrop Delivery (LVAD) system and Willy’s Jeep. We report on the cost and time required for the development of both tooling and parts. Second, the program focused on expanding the BAAM technology to directly manufacture aluminum and steel components. A robotic welding system was developed, test articles manufactured and with a final deliverable of a steel bumper manufactured and installed on the Jeep. This report covers the results of the program and describes follow-on efforts to commercialize the technology.

36 MATERIALS SCIENCE↗
NASA NTRS1978

Volcanism in the cratered terrain hemisphere of Mars

Four kinds of Martian volcanoes and their prevalences in the cratered terrain hemisphere (generally the southern hemisphere) are described. Patera, which are large low-profile volcanic structures, appear to be either older shield volcanoes or a unique type of volcano. 'Plains' volcanics represent low-volume eruptions that formed cones, low shields, and other small-scale structures. Flood volcanics are produced by high-volume eruptions, post-date the older and more degraded plateau plains, and occur mostly as basin-fill materials. Plateau plains, the Martian intercrater plains, contain many wrinkle ridges and floor-fractured craters. It is suggested that volcanic processes as well as erosional processes have been important in obliterating small Martian craters and that volcanic products may constitute a significant fraction (up to 44%) of the surface rocks in the cratered terrain

Greeley, R.↗
DOE OSTI2020

Sizing Small-Scale Renewable Energy Systems for the Navajo Nation and Rural Communities

The Navajo Nation consists of about 55,000 residential homes spread across 27,000 square miles of trust land in the Southwest region of the United States. The Navajo Tribal Utility Authority (NTUA) reports that approximately 15,000 homes on the reservation do not have electricity due to the high costs of connecting rural homes located miles from utility distribution lines. In order to get these rural homeowners access electricity, NTUA and other Native owned companies are examining small-scale renewable energy systems to provide power for necessary usage such as lighting and refrigeration. The goal of this study is to evaluate the current renewable deployment efforts and provide additional considerations for photovoltaic (PV) systems that will optimize performance and improve efficiency to reduce costs. There are three case studies presented in different locations on the Navajo Nation with varying solar resource and energy load requirements. For each location, an assessment is completed that includes environmental parameters of the site- specific landscape and a system performance analysis of an off-grid residential PV system. The technical process, repeated for each location, demonstrates how the variance and uniqueness of each household can impact the system requirements after optimizations are applied. Therefore, the household variabilities and difference in locations must be considered. The differing results of each case study suggests additional analysis is needed for designing small-scale PV systems that takes a home-land-family specific approach to allow for better efficiency and more flexibility for future solar innovations to be considered for overall cost reductions.

14 SOLAR ENERGY↗
DOE OSTI2023

A deep learning upscaling framework: Reactive transport and mineral precipitation in fracture-matrix systems

Pore-scale modeling has limited applicability at large scales due to its high computational cost. One common approach to upscale pore-scale models is the use of effective medium theories, which homogenize small-scale features in a porous structure and characterize the medium by macroscale properties (e.g., permeability) and equations (e.g., Darcy’s law). However, there are classes of physical processes for which effective medium approximations may become inaccurate, e.g., mineral precipitation and clogging during reactive transport. We have developed a deep learning upscaling framework, in which pore-scale modeling is directly employed in macroscale systems, without relying on effective medium approximations. The upscaling framework is first developed for general multiscale systems and then applied to modeling reactive transport with mineral precipitation in the altered layer in fracture-matrix structures. Solute transport from the fractures to the matrix is modeled as a wall boundary condition for the fractures, which, in turn, is predicted by recurrent neural networks using the concentration histories at the fracture-matrix boundary. Specifically, we consider a meter-scale fracture network embedded in sandstones, where the smallest feature is at the micron scale. Here the proposed framework allows us to span five orders of magnitude in length scales by capturing mineral precipitation in the altered layer of the rock matrix at the pore scale across the entire meter-scale fracture network.

42 ENGINEERING↗
DOE OSTI2016

Relating structure and composition with accessibility of a single catalyst particle using correlative 3-dimensional micro-spectroscopy

To understand how hierarchically structured functional materials operate, analytical tools are needed that can reveal small structural and chemical details in large sample volumes. Often, a single method alone is not sufficient to get a complete picture of processes happening at multiple length scales. Here we present a correlative approach combining three-dimensional X-ray imaging techniques at different length scales for the analysis of metal poisoning of an individual catalyst particle. The correlative nature of the data allowed establishing a macro-pore network model that interprets metal accumulations as a resistance to mass transport and can, by tuning the effect of metal deposition, simulate the response of the network to a virtual ageing of the catalyst particle. In conclusion, the developed approach is generally applicable and provides an unprecedented view on dynamic changes in a material’s pore space, which is an essential factor in the rational design of functional porous materials.

36 MATERIALS SCIENCE↗
DOE OSTI2016

Chemical Biology And Endomembrane Trafficking In Plants

Endomembrane trafficking is essential for coordinated growth and development in plants and response to environment. In particular, key plasma membrane proteins such as PIN auxin transporters and the BRI1 brassinosteroid receptor translocate dynamically between the endosomes and plasma membrane. We utilized a previously published large‐scale chemical library screening approach in which we identified small molecules that inhibited pollen germination or tube growth. This tip growth requires exocytosis, endocytosis and other endomembrane trafficking processes We then identified groups of small molecules that affect trafficking of PIN auxin transporters and other plasma membrane proteins in Arabidopsis roots. One of these compounds (ES2) targets the essential EXO70A1 component of the exocyst complex in Arabidopsis which is necessary for normal development. In Arabidopsis, there are 23 EXO70 genes (in mammals and yeast they are low copy number) where, among other roles, they appear to be involved in autophagy, cell division and pathogen responses. ES2 targets the exocyst complex in plants as well as mammals including humans where defective recycling/exocytosis have been correlated with disease. To our knowledge, ES2 is the first bioactive compound known to have this specificity. To examine exocytosis and its regulation in more detail, we have examined exo70 mutants, generated EXO70A1 structural data and are examining additional small molecules that may affect recycling/exocytosis. Support or Funding Information Acknowledgement: This work was supported by the US Department of Energy DE‐FG02‐02ER15295 (GRH, NVR).

Hicks, Glenn R.↗