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DOE OSTI2018

Some Problems of Distributed and Boundary Control for Systems with Integral Aftereffect

We consider the problem of exact control for a system described by an equation with integral “memory.” It is shown that, under certain conditions, this system can be brought to rest in finite time by distributed control bounded in absolute value, and, in a special one-dimensional case, by control applied to an end-point of the interval. We consider different types of kernels in the integral term of the equation and describe some relationships between problems of controllability of some hyperbolic and parabolic systems.

97 MATHEMATICS AND COMPUTING↗

DOE OSTI2017

Spatial biomarker of disease and detection of spatial organization of cellular receptors

A signature of a condition of a live cell is established in an assay that allows distribution of the receptors on the cell surface in response to binding a ligand. The receptors can be optically detected and quantified to provide a value for the condition, Test drugs can be screened for therapeutic potential in the assay: a potentially efficacious drug is identified by an ability to modulate an established signature. The receptor distribution signature can be corroborated with an mRNA expression profile of several genes, indicating, for example, metastasis.

59 BASIC BIOLOGICAL SCIENCES↗

DOE OSTI2018

Numerical Simulation of Bulging Deformation for Wide-Thick Slab Under Uneven Cooling Conditions

In the present work, the bulging deformation of a wide-thick slab under uneven cooling conditions was studied using finite element method. The non-uniform solidification was first calculated using a 2D heat transfer model. The thermal material properties were derived based on a microsegregation model, and the water flux distribution was measured and applied to calculate the cooling boundary conditions. Based on the solidification results, a 3D bulging model was established. The 2D heat transfer model was verified by the measured shell thickness and the slab surface temperature, and the 3D bulging model was verified by the calculated maximum bulging deflections using formulas. The bulging deformation behavior of the wide-thick slab under uneven cooling condition was then determined, and the effect of uneven solidification, casting speed, and roll misalignment were investigated.

36 MATERIALS SCIENCE↗

DOE OSTI2015

Constrained Surface Complexation Modeling: Rutile in RbCl, NaCl, and NaCF 3 SO 3 Media to 250 °C

In this paper, a comprehensive set of molecular-level results, primarily from classical molecular dynamics (CMD) simulations, are used to constrain CD-MUSIC surface complexation model (SCM) parameters describing rutile powder titrations conducted in RbCl, NaCl, and NaTr (Tr = triflate, CF 3 SO 3 – ) electrolyte media from 25 to 250 °C. Rb + primarily occupies the innermost tetradentate binding site on the rutile (110) surface at all temperatures (25, 150, 250 °C) and negative charge conditions (-0.1 and -0.2 C/m 2 ) probed via CMD simulations, reflecting the small hydration energy of this large, monovalent cation. Consequently, variable SCM parameters (Stern-layer capacitance values and intrinsic Rb + binding constants) were adjusted relatively easily to satisfactorily match the CMD and titration data. The larger hydration energy of Na + results in a more complex inner-sphere distribution, which shifts from bidentate to tetradentate binding with increasing negative charge and temperature, and this distribution was not matched well for both negative charge conditions, which may reflect limitations in the CMD and/or SCM approaches. Finally, in particular, the CMD axial density profiles for Rb + and Na + reveal that peak binding distances shift toward the surface with increasing negative charge, suggesting that the CD-MUSIC framework may be improved by incorporating CD or Stern-layer capacitance values that vary with charge.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Doubling of U.S. Population Exposure to Climate Extremes by 2050

We quantify historical and projected trends in the population exposure to climate extremes as measured by the United States National Center for Environmental Information Climate Extremes Index (CEI). Based on the analyses of the historical observations, we find that the U.S. has already experienced a rise in the occurrence of aggregated extremes in recent decades, consistent with the climate response to historical increases in radiative forcing. Additionally, we find that exposure can be expected to intensify under the Representative Concentration Pathway 8.5, with all counties permanently exceeding the baseline variability in the occurrence of extreme hot days, warm nights, and drought conditions by 2050. As a result, every county in the U.S. is projected to permanently exceed the historical CEI variability (as measured by one standard deviation during the 1981–2005 period). Based on the current population distribution, this unprecedented change implies a yearly exposure to extreme conditions for one in every three people. We find that the increasing trend in exposure to the aggregated extremes is already detectable over much of the U.S., and particularly in the central and eastern U.S. The high correspondence between the pattern of trends in our simulations and observations increases confidence in the projected amplification of population exposure to unprecedented combinations of extreme climate conditions, should greenhouse gas concentrations continue to escalate along their current trajectory.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2017

Dielectric tensor of low-dimensional metal systems

The dielectric tensor of a low-dimensional metal system has been introduced on the basis of the density matrix in the relaxation time approximation. The properties of this tensor have been analyzed. It has been proved that anisotropy and nonlocality are decisive features of the response of low-dimensional systems to an electromagnetic field. In particular, the expression has been derived for the dielectric tensor of nanometer- thick metal films. It has been shown that the dielectric tensor components can be reduced to the Drude dielectric function for a homogeneous metal in the case when the film thickness considerably exceeds the effective electron mean free path. The application of the classical distribution function for describing electrons in the film is justified under these conditions.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

DOE OSTI2013

Four-Dimensional Finite-Orbit-Width Fokker-Planck Code with Sources, for Neoclassical/Anomalous Transport Simulation of Ion and Electron (Final Technical Report)

Within the US Department of Energy/Office of Fusion Energy magnetic fusion research program, there is an important whole-plasma-modeling need for a radio-frequency/neutral-beam-injection (RF/NBI) transport-oriented finite-difference Fokker-Planck (FP) code with combined capabilities for 4D (2R2V) geometry near the fusion plasma periphery, and computationally less demanding 3D (1R2V) bounce-averaged capabilities for plasma in the core of fusion devices. Demonstration of proof-of-principle achievement of this goal has been carried out in research carried out under Phase I of the SBIR award. Two DOE-sponsored codes, the CQL3D bounce-average Fokker-Planck code in which CompX has specialized, and the COGENT 4D, plasma edge-oriented Fokker-Planck code which has been constructed by Lawrence Livermore National Laboratory and Lawrence Berkeley Laboratory scientists, where coupled. Coupling was achieved by using CQL3D calculated velocity distributions including an energetic tail resulting from NBI, as boundary conditions for the COGENT code over the two-dimensional velocity space on a spatial interface (flux) surface at a given radius near the plasma periphery. The finite-orbit-width fast ions from the CQL3D distributions penetrated into the peripheral plasma modeled by the COGENT code. This combined code demonstrates the feasibility of the proposed 3D/4D code. By combining these codes, the greatest computational efficiency is achieved subject to present modeling needs in toroidally symmetric magnetic fusion devices. The more efficient 3D code can be used in its regions of applicability, coupled to the more computationally demanding 4D code in higher collisionality edge plasma regions where that extended capability is necessary for accurate representation of the plasma. More efficient code leads to greater use and utility of the model. An ancillary aim of the project is to make the combined 3D/4D code user friendly. Achievement of full-coupling of these two Fokker-Planck codes will advance computational modeling of plasma devices important to the USDOE magnetic fusion energy program, in particular the DIII-D tokamak at General Atomics, San Diego, the NSTX spherical tokamak at Princeton, New Jersey, and the MST reversed-field-pinch Madison, Wisconsin. The validation studies of the code against the experiments will improve understanding of physics important for magnetic fusion, and will increase our design capabilities for achieving the goals of the International Tokamak Experimental Reactor (ITER) project in which the US is a participant and which seeks to demonstrate at least a factor of five in fusion power production divided by input power.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

DOE OSTI2022

Investigation of the impact of supplemental reflective films to improve micro-light climate within tomato plant canopy in solar greenhouses

The non-uniform growth and development of crops within Chinese Solar Greenhouses (CSG) is directly related to the micro-light climate within canopy. In practice, reflective films are used to improve micro-light climate within plant canopy by homogenizing light distribution and so increasing total plant light interception. However, as to our knowledge, the contributions to light distribution within canopy have not been investigated for passive reflector like reflective films. Field experiments dealing with light conditions and growth behavior over time, are complicated to carry out, time-consuming and hard to control, while however, accurate measurements of how reflective films influence the micro-light climate of canopy are an essential step to improve the growth conditions for any crop. Here, we propose a supplementary light strategy using reflective films to improve light distribution within plant canopy. Based on the example of CSG, a 3D greenhouse model including a detailed 3D tomato canopy structure was constructed to simulate the influence of supplementary reflective films to improve micro-light climate. Comparison of measured solar radiation intensity with predicted model data demonstrated that the model could precisely predict light radiation intensity over time with different time points and positions in the greenhouse. A series of reflective film configurations were investigated based on features analysis of light distribution in the tomato canopy on sunny days using the proposed model. The reflective film configuration scheme with the highest impact significantly improved the evenness of horizontal and vertical light distribution in tomato canopy. The strategy provided here can be used to configure reflective films that will enhance light conditions in CSG, which can be applied and extended in different scenarios.

Liu, Anhua↗

NASA NTRS1981

Heat transfer of phase-change materials in two-dimensional cylindrical coordinates

Two-dimensional phase-change problem is numerically solved in cylindrical coordinates (r and z) by utilizing two Taylor series expansions for the temperature distributions in the neighborhood of the interface location. These two expansions form two polynomials in r and z directions. For the regions sufficiently away from the interface the temperature field equations are numerically solved in the usual way and the results are coupled with the polynomials. The main advantages of this efficient approach include ability to accept arbitrarily time dependent boundary conditions of all types and arbitrarily specified initial temperature distributions. A modified approach using a single Taylor series expansion in two variables is also suggested.

Labdon, M. B.↗

NASA NTRS1987

Convergence properties of modal costs for certain distributed parameter systems

A complete modal cost analysis is presented for the vibration of various kinds of simple continua with different boundary conditions. Explicit formulas for the norm of the response (called the 'cost') are derived for these distributed parameter systems. The convergence theorems developed are useful in the model reduction of the equivalent continuum models of large space structures as well as in the selection of finite-element code for control design.

Hu, A.↗

NASA NTRSDate not supplied

Contrails Measurement and Testing Capabilities in NASA's Particulate Aerosol Laboratory

The NASA Glenn Research Center Particulate Aerosol Laboratory (PAL) is a ground test facility for studying emissions and contrails at upper atmospheric conditions. The facility consists of a small-scale combustor that generates hot combustion gases and soot nanoparticles, which flow through a transition pipe into a jet nozzle, which exhausts into an altitude chamber. Thermodynamic conditions experienced in flight are matched in the altitude chamber, allowing the study of ice particle formation of simulated aircraft engine exhaust plumes. A non-intrusive optical diagnostic technique based on Mie scattering provides ice particle size, number density, and mass density. A suite of commercial extractive particle measurement instruments provides estimates of soot number density, size, and black carbon mass distributions. Measurements are presented for various fuels at chamber conditions covering an altitude range of 20,000 ft (6 km) to 45,000 ft (14 km) altitude and ambient temperatures from -48°C to -68°C. The data presented demonstrate the effect of soot number density, altitude, and fuel-to-air equivalence ratio on the contrail ice particle formation. Ice mass density measurements are compared to values predicted by a thermodynamic plume similarity solution.

Optical Instrumentation↗

DOE OSTI2016

Simultaneously Synchrotron X-ray Fluorescence and Ptychographic Imaging of Frozen Biological Single Cells

Bionanoprobe (BNP), a hard x-ray fluorescence sample-scanning nanoprobe at the Advanced Photon Source of Argonne National Laboratory, has been used to quantitatively study elemental distributions in biological cells with sub-100 nm spatial resolution and high sensitivity. Cryogenic conditions enable biological samples to be studied in their frozen-hydrated state with both ultrastructure and elemental distributions more faithfully preserved compared to conventional chemical fixation or dehydration methods. Furthermore, radiation damage is reduced in two ways: the diffusion rate of free radicals is decreased at low temperatures; and the sample is embedded in vitrified ice, which reduces mass loss.

59 BASIC BIOLOGICAL SCIENCES↗

NASA NTRS1988

MCT crystal growth

Convection and segregation in directional solidification and crystal growth by the Bridgman-Stockbarger technique are traditionally treated by assuming axisymmetric thermal condition on the ampoule wall. It is, however, difficult to achieve such a condition in an experimental setup. Any deviation from an axisymmetric temperature field on the wall of a vertical ampoule represents a horizontal temperature gradient. The horizontal density gradient that results from thermal expansion in the melt under this condition must lead on earth to some buoyance-driven convection, no matter what the axial (vertical) temperature distribution that is imposed on the melt. The magnitude of such convective flows for conditions representative of the MSFC mercury-cadmium-telluride (MCT) Bridgman setup is studied.

Baird, James K.↗

DOE OSTI2020

Ultrasonic Measurements of Temperature Distribution in Extreme Environments: Results of Power Plant Testing

The most hardened insertion sensors do not perform reliably in extreme environmental conditions. We address this problem by developing an ultrasonic thermometry system for the measurements of segmental temperature distributions (MSTD) in solid materials and, specifically, across containments of energy conversion processes. The MSTD approach uses an echogenically segmented ultrasound propagation path, structured to contain engineered or naturally occurring echogenic features. In pulse-echo mode, these features produce a train of echoes in response to an external pulse of ultrasonic excitation created and acquired by a transducer located outside the extreme environment. The delays between the echoes encode the information on the temperature distribution in the corresponding segments of the ultrasonic propagation path, which we use to reconstruct an unknown temperature profile. This note describes the preliminary results and initial experience in applying the developed MSTD ultrasonic thermometry system to the measurements of temperatures in a utility-scale 500MW coal-fired boiler.

John, Mason↗

DOE OSTI2021

Evaluation of Centralized Model Based FLISR in a Lab Setup

Utilities are installing advanced distribution management systems (ADMS) around the globe to improve the sensing and control of distribution systems. ADMS is becoming a critical component to improve the resiliency and reliability of distribution systems. These management systems host a multitude of applications that can be used to sense, control, and operate distribution systems. Fault location, isolation, and service restoration (FLISR) is one of the ADMS applications that is critical to improving resilience during fault conditions. FLISR applications use smart, controllable devices that are installed in the distribution system for FLISR operation. These controllable devices include distributed energy resources (DER) and reclosers. Evaluating such ADMS applications before installation in the field can help de-risk the field implementation and avoid costly failures in the field. This paper presents a background on experimental setup that are typically used to evaluate ADMS applications. This is followed by briefly presenting the setup used to evaluate the FLISR application in an off-the-shelf ADMS tool. Finally, results from the evaluation experiments are presented.

94 GMLC - Grid Modernization Laboratory Consortium↗

NASA NTRS2001

Spatial Distribution of Cyanobacteria in Modern Stromatolites

Living stromatolites consist of complex microbial communities with distinct distribution patterns for different microbial groups. The cyanobacterial populations of Highborne Cay Bahamas exemplify this phenomenon. Field observations reveal distinct distribution patterns for several of these cyanobacterial species. To date 10 different cyanobacterial cultures, including both filamentous and endolithic species, have been isolated from these stromatolites. We will present data on the growth and motility characteristics as well as on the nutritional requirements of these isolates. These data will then be correlated with the field observed distributions for these species. Lastly laboratory simulations of stromatolites grown under various conditions of irradiance, flow and cyanobacterial community composition will be presented. These experiments allow us to evaluate our predictions regarding controls on cyanobacterial distribution.

Prufert-Bebout, Lee↗

DOE OSTI2021

Evaluation of Centralized Model-Based FLISR in a Lab Setup: Preprint

94 GMLC - Grid Modernization Laboratory Consortium↗

DOE OSTI2020

Cesium Removal and Hydraulic Performance Comparisons of CST Ion Exchange Media Batches in Support of the Tank Closure Cesium Removal Project - 20522

Three batches of Crystalline Silicotitanate (CST) ion exchange media have been evaluated for cesium removal efficiency from a Savannah River Site (SRS) High Level Waste (HLW) supernate simulant in support of the Tank Closure Cesium Removal (TCCR) Project, which involves at-tank column waste treatment. Results will be utilized to select the CST media batch to be added to the next TCCR unit columns. Two of the CST media samples were recent production batches and the third was an archived batch studied extensively at SRS nearly two decades ago. The archived CST batch had a significantly smaller average particle diameter than more recent batches. Small-scale (∼23 mL), side-by-side column tests were conducted at 35 deg. C with each of the CST batches using the same simulant at flow rates near 1.2 mL/min (3.0-3.4 CST bed volumes/hr). The cesium ion exchange column performance results were lower than expected for all three CST batches, but the data indicated that 30% more simulant volume and 40% more equivalent CST bed volumes of solution can be processed with the older CST batch prior to reaching the 50% cesium breakthrough point than can be processed with the newer CST batches. Hydraulic evaluations of the CST columns were also conducted in simulant at 24 deg. C to determine the impact of the different particle size distributions and associated bed porosities on frictional pressure drop under dynamic flow conditions. Higher differential pressure drops were observed with the archived CST batch relative to recent production batches, due to the smaller particle size distribution and the packing characteristics of the archived batch. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

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