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All sourcesNASA NTRSDOE OSTI
DOE OSTI2011

Quantitative proteomics analysis of adsorbed plasma proteins classifies nanoparticles with different surface properties and size

In biofluids (e.g., blood plasma) nanoparticles are readily embedded in layers of proteins that can affect their biological activity and biocompatibility. Herein, we report a study on the interactions between human plasma proteins and nanoparticles with a controlled systematic variation of properties using stable isotope labeling and liquid chromatography-mass spectrometry (LC-MS) based quantitative proteomics. Novel protocol has been developed to simplify the isolation of nanoparticle bound proteins and improve the reproducibility. Plasma proteins associated with polystyrene nanoparticles with three different surface chemistries and two sizes as well as for four different exposure times (for a total of 24 different samples) were identified and quantified by LC-MS analysis. Quantitative comparison of relative protein abundances were achieved by spiking an 18 O-labeled 'universal reference' into each individually processed unlabeled sample as an internal standard, enabling simultaneous application of both label-free and isotopic labeling quantitation across the sample set. Clustering analysis of the quantitative proteomics data resulted in distinctive pattern that classifies the nanoparticles based on their surface properties and size. In addition, data on the temporal study indicated that the stable protein 'corona' that was isolated for the quantitative analysis appeared to be formed in less than 5 minutes. The comprehensive results obtained herein using quantitative proteomics have potential implications towards predicting nanoparticle biocompatibility.

18 O labeling↗
DOE OSTI2016

SU-F-J-18: Feasibility of Open Mask Immobilization with Optical Imaging Guidance (OIG) for H&N Radiotherapy

Purpose: Full face and neck thermoplastic masks provide standard-of-care immobilization for patients receiving H&N IMRT. However, these masks are uncomfortable and increase skin dose. The purpose of this pilot study was to investigate the feasibility and setup accuracy of open face and neck mask immobilization with OIG. Methods: Ten patients were consented and enrolled to this IRB-approved protocol. Patients were immobilized with open masks securing only forehead and chin. Standard IMRT to 60–70 Gy in 30 fractions were delivered in all cases. Patient simulation information, including isocenter location and CT skin contours, were imported to a commercial OIG system. On the first day of treatment, patients were initially set up to surface markings and then OIG referenced to face and neck skin regions of interest (ROI) localized on simulation CT images, followed by in-room CBCT. CBCTs were acquired at least weekly while planar OBI was acquired on the days without CBCT. Following 6D robotic couch correction with kV imaging, a new optical real-time surface image was acquired to track intrafraction motion and to serve as a reference surface for setup at the next treatment fraction. Therapists manually recorded total treatment time as well as couch shifts based on kV imaging. Intrafractional ROI motion tracking was automatically recorded. Results: Setup accuracy of OIG was compared with CBCT results. The setup error based on OIG was represented as a 6D shift (vertical/longitudinal/lateral/rotation/pitch/roll). Mean error values were −0.70±3.04mm, −0.69±2.77mm, 0.33±2.67 mm, −0.14±0.94 o, −0.15±1.10o and 0.12±0.82o, respectively for the cohort. Average treatment time was 24.1±9.2 minutes, comparable to standard immobilization. The amplitude of intrafractional ROI motion was 0.69±0.36 mm, driven primarily by respiratory neck motion. Conclusion: OGI can potentially provide accurate setup and treatment tracking for open face and neck immobilization. Study accrual and patient/provider satisfaction survey collection remain ongoing. This study is supported by VisionRT, Ltd.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2012

Consolidative Involved-Node Proton Therapy for Stage IA-IIIB Mediastinal Hodgkin Lymphoma: Preliminary Dosimetric Outcomes From a Phase II Study

Purpose: To compare the dose reduction to organs at risk (OARs) with proton therapy (PT) versus three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT) in patients with mediastinal Hodgkin lymphoma (HL) enrolled on a Phase II study of involved-node radiotherapy (INRT). Methods and Materials: Between June 2009 and October 2010, 10 patients were enrolled on a University of Florida institutional review board-approved protocol for de novo 'classical' Stage IA-IIIB HL with mediastinal (bulky or nonbulky) involvement after chemotherapy. INRT was planned per European Organization for Research and Treatment of Cancer guidelines. Three separate optimized plans were developed for each patient: 3D-CRT, IMRT, and PT. The primary end point was a 50% reduction in the body V4 with PT compared with 3D-CRT or IMRT. Results: The median relative reduction with PT in the primary end point, body V4, was 51% compared with 3D-CRT (p = 0.0098) and 59% compared with IMRT (p = 0.0020), thus all patients were offered treatment with PT. PT provided the lowest mean dose to the heart, lungs, and breasts for all 10 patients compared with either 3D-CRT or IMRT. The median difference in the OAR mean dose reduction with PT compared with 3D-CRT were 10.4 Gy/CGE for heart; 5.5 Gy/CGE for lung; 0.9 Gy/CGE for breast; 8.3 Gy/CGE for esophagus; and 4.1 Gy/CGE for thyroid. The median differences for mean OAR dose reduction for PT compared with IMRT were 4.3 Gy/CGE for heart, 3.1 Gy/CGE for lung, 1.4 Gy/CGE for breast, 2.8 Gy/CGE for esophagus, and 2.7 Gy/CGE for thyroid. Conclusions: All 10 patients benefitted from dose reductions to OARs with PT compared with either 3D-CRT or IMRT. It is anticipated that these reductions in dose to OAR will translate into lower rates of late complications, but long-term follow-up on this Phase II INRT study is needed.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2026

Experimental protocol for phase 1 of the APARC QUOCA (QUasibiennial oscillation and Ozone Chemistry interactions in the Atmosphere) working group

The quasi-biennial oscillation (QBO) is the main mode of variability in the tropical stratosphere, influencing the predictability of other regions in the atmosphere through its teleconnections to the stratospheric polar vortices and coupling to surface tropical and extratropical variability. However, climate and forecasting models consistently underestimate QBO amplitudes in the lower stratosphere, likely contributing to their failure to simulate these teleconnections. One underexplored contributor to model biases is missing representation of ozone-radiative feedbacks, which enhance temperature variability in the lower stratosphere, particularly at periods at and greater than the QBO (>28 months). While previous studies suggest that ozone-radiative feedbacks can impact QBO periods, amplitudes and the associated secondary circulation in the lower stratosphere, the reported impacts differ widely among models and are hard to interpret due to differences in methodology. To this end, here we propose a coordinated experimental protocol – held joint between the Atmospheric Processes and their Role in Climate (APARC) Quasi-Biennial Oscillation Initiative (QBOi) and Chemistry Climate Modeling Initiative (CCMI) activities – which is aimed at assessing the coupling between stratospheric ozone, temperature and the circulation. We use the proposed experiments to define the ozone feedback on the QBO in both present-day and idealized (abrupt quadrupling of carbon dioxide) climates. While primary focus is on the QBO, the proposed protocol also enables analysis of other aspects of ozone-radiative-dynamical coupling in the atmosphere, including impacts on the Brewer-Dobson Circulation and tropospheric eddy-driven jet responses to future climate change. Here we document the scientific rationale and design of the QUOCA Phase 1 experiments, summarize the data request, and give a brief overview of participating models. Preliminary results using the NASA Goddard Institute for Space Studies E2-2 climate model are used to illustrate sensitivities to certain methodological choices.

Environmental sciences↗
DOE OSTI2015

High-resolution elemental mapping of human placental chorionic villi using synchrotron X-ray fluorescence spectroscopy

The placenta is the organ that mediates transport of nutrients and waste materials between mother and fetus. Synchrotron X-ray fluorescence (SXRF) microanalysis is a tool for imaging the distribution and quantity of elements in biological tissue, which can be used to study metal transport across biological membranes. Our aims were to pilot placental biopsy specimen preparation techniques that could be integrated into an ongoing epidemiology birth cohort study without harming rates of sample acquisition. We studied the effects of fixative (formalin or glutaraldehyde) and storage duration (30 days or immediate processing) on metal distribution and abundance and investigated a thaw-fixation protocol for archived specimens stored at -80° C. We measured fixative elemental composition with and without a placental biopsy via inductively coupled plasma mass spectrometry (ICP-MS) to quantify fixative-induced elemental changes. Formalin-fixed specimens showed hemolysis of erythrocytes. The glutaraldehyde-paraformaldehyde solution in HEPES buffer (GTA-HEPES) had superior anatomical preservation, avoided hemolysis, and minimized elemental loss, although some cross-linking of exogenous Zn was evident. Elemental loss from tissue stored in fixative for 1 month showed variable losses (≈ 40 % with GTA-HEPES), suggesting storage duration be controlled for. Lastly, thawing of tissue held at -80 °C in a GTA-HEPES solution provided high-quality visual images and elemental images

60 APPLIED LIFE SCIENCES↗
DOE OSTI2023

Novel method for accurately estimating membrane transport properties and mass transfer coefficients in reverse osmosis

Here, we present a simple and robust method to simultaneously characterize the water and salt permeability (A, B) of reverse osmosis (RO) membranes and mass transfer coefficient (k) in membrane modules. The proposed methodology comprises a set of RO experiments performed at different operating pressures or stages. The measured water and salt fluxes in each stage are simultaneously fitted to the RO transport equations by performing a non-linear regression, using A, B, and k as regression parameters. We first perform a systematic accuracy analysis of the proposed method across the full operational range of RO. The assessment shows that the method accuracy is substantially higher than current methods and increases with number of experimental stages and driving forces. This assessment is used to inform the design of an experimental protocol that minimizes errors in estimated A, B, and k. We then evaluate two commercial RO membranes following the new protocol. For both membranes, A and B parameters decrease by 17% and 15% from the dilute solution to seawater concentrations, whereas the k parameter remains constant. Our study demonstrates that the proposed method, informed by data-driven experimental designs, provides a new approach for accurately characterizing transport phenomenon in membrane processes with feeds of less than 100 g/L total dissolved solids.

36 MATERIALS SCIENCE↗
DOE OSTI2018

Assessment of the hepatocytic differentiation ability of human skin-derived ABCB5+ stem cells

Highlights: • Stem cell-derived hepatocytes may be used for cell therapy of liver diseases. • ABCB5-positive stem cell feature characteristics of mesenchymal stromal cells. • Hepatocytic differentiation of ABCB5{sup +} stem cells is incomplete. • However, they secrete hepatotropic factors that may support liver regeneration. • Hepatic delivery of the cells does not cause obvious adverse effects in the mouse. The continuously decreasing willingness for liver donation aggravates treatment of end-stage liver diseases requiring organ transplantation as the only curative strategy. Cell therapy approaches using human hepatocytes or stem cell-derived hepatocyte-like cells may be a therapeutic option out of this dilemma. ABCB5-positive mesenchymal stromal cells from human skin featured promising potential to treat immune-mediated diseases. Since most of chronic liver diseases involve exaggerating immune mechanisms, it was the aim to demonstrate in this study, whether ABCB5{sup +} stem cells may serve as a resource to generate hepatocytic cells for application in liver cell transplantation. Using an established single-step protocol, which had been successfully applied to differentiate mesenchymal stromal cells into the hepatocytic lineage, ABCB5{sup +} skin-derived stem cells did not gain significant characteristics of hepatocytes. Yet, upon culture in hepatocytic differentiation medium, ABCB5{sup +} stem cells secreted immunomodulatory and anti-fibrotic factors as well as proteins, which may prompt hepatic morphogenesis besides others. Hepatic transplantation of ABCB5{sup +} stem cells, which had been prior cultured in hepatocytic differentiation medium, did not cause any obvious deterioration of liver architecture suggesting their safe application. Thus, human ABCB5{sup +} skin-derived stem cells secreted putative hepatotropic factors after culture in hepatocytic differentiation medium.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

Formation and surface melting of nanoparticle superlattices in a solution

The wisdom in the saying of “There are no two snowflakes alike” lies in the importance of history or kinetic pathways in the phase transitions of solids. Likewise, “artificial solids,” namely superlattices consisting of functional nanoparticles, have lattice size, surface morphology, crystallinity, symmetry, and structural reconfiguration (for example, transition into a disordered state) highly dependent on the kinetic pathways as the nanoparticles interact with each other in solution [1]. Great progresses have been made in understanding the formation pathways of superlattices using liquid-phase transmission electron microscopy (TEM) [2-4]. For example, by tracking single nanoparticle’s trajectories, especially aided by U-net neural network-based machine learning, previous studies mapped the fundamental nanoparticle interactions at nanometer resolution [5]. Nonclassical, two-step nucleation pathway has also been elucidated in the system of nanoprisms, by optimizing protocols such as loading nanoparticle suspensions over the supersaturation threshold and minimizing particle‒substrate interaction [2]. Surface morphologies or exposed facets of superlattices have been shown to follow the principles of Wulff construction rule, where the facet-dependent surface energy can be measured based on the capillary wave theory [4]. However, the reverse process of crystallization of superlattices, the conversion from crystalline to disordered state, has been much less explored. On one hand, the melting of nanoparticle superlattices can provide a preferred pathway to induce structural reorganization or shuffling of building blocks for them to transform into different types of crystal structures. On the other hand, understanding nanoscale superlattice melting and comparing such behaviors with the prevailing surface melting theories developed for atomic/molecular solids can provide a potent way to engineer phase transitions of supra- and hierarchical structures constructed from nanoscale entities (e.g., DNA-coated nanoparticles, proteins), for their applications in reprogrammable and switchable materials with multifunctional properties [6, 7]. The experimental challenges to observe melting of superlattices are twofold. Practically it is difficult to load the initial superlattice form, in an intact manner, into the highly confined liquid-phase TEM chamber for in-situ observation. Here, the triggering of melting also needs meticulous manipulation of nanoparticle concentration, interparticle interaction, and solution environment.

Kim, Ahyoung↗
DOE OSTI2010

Deactivation Mechanisms of Ni-Based Tar Reforming Catalysts As Monitored by X-ray Absorption Spectroscopy

Deactivation mechanisms of alumina-supported, Ni-based catalysts for tar reforming in biomass-derived syngas were evaluated using extended X-ray absorption fine structure (EXAFS) spectroscopy. Catalysts were characterized before and after catalytic reaction cycles and regeneration procedures, which included oxidation by a mixture of steam and air, and reduction in hydrogen. Qualitative analysis of the EXAFS spectra revealed that oxidation of a portion of the Ni in the catalysts to form an oxide phase and/or a sulfide phase were likely scenarios that led to catalyst deactivation with time-on-stream and with increased reaction cycles. Deactivation through carbon deposition, phosphorus poisoning, or changes in particle size were deemed as unlikely causes. Quantitative analysis of the EXAFS spectra indicated sulfur poisoning occurred with time-on-stream, and the contaminating species could not be completely removed during the regeneration protocols. The results also verified that Ni-containing oxide phases (most likely a spinel also containing Mg and Al) formed and contributed to the deactivation. This study validates the need for developing catalyst systems that will protect Ni from sulfur poisoning and oxide formation at elevated reaction and regeneration temperatures.

08 HYDROGEN↗
DOE OSTI2023

Large-scale analysis of structural brain asymmetries in schizophrenia via the ENIGMA consortium

Left–right asymmetry is an important organizing feature of the healthy brain that may be altered in schizophrenia, but most studies have used relatively small samples and heterogeneous approaches, resulting in equivocal findings. We carried out the largest case–control study of structural brain asymmetries in schizophrenia, with MRI data from 5,080 affected individuals and 6,015 controls across 46 datasets, using a single image analysis protocol. Asymmetry indexes were calculated for global and regional cortical thickness, surface area, and subcortical volume measures. Differences of asymmetry were calculated between affected individuals and controls per dataset, and effect sizes were meta-analyzed across datasets. Small average case–control differences were observed for thickness asymmetries of the rostral anterior cingulate and the middle temporal gyrus, both driven by thinner left-hemispheric cortices in schizophrenia. Analyses of these asymmetries with respect to the use of antipsychotic medication and other clinical variables did not show any significant associations. Assessment of age- and sex-specific effects revealed a stronger average leftward asymmetry of pallidum volume between older cases and controls. Case–control differences in a multivariate context were assessed in a subset of the data (N = 2,029), which revealed that 7% of the variance across all structural asymmetries was explained by case–control status. Subtle case–control differences of brain macrostructural asymmetry may reflect differences at the molecular, cytoarchitectonic, or circuit levels that have functional relevance for the disorder. Reduced left middle temporal cortical thickness is consistent with altered left-hemisphere language network organization in schizophrenia.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2023

Continuous variable port-based teleportation

Abstract Port-based teleportation (PBT) is a generalisation of the standard teleportation protocol which does not require unitary operations by the receiver. This comes at the price of requiring N > 1 entangled pairs, while N = 1 for the standard teleportation protocol. The lack of correction unitaries allows PBT to be used as a fundamental theoretical tool to simulate arbitrary channels with a general resource, with applications to study fundamental limits of quantum communication, cryptography and sensing, and to define general programmable quantum computers. Here we introduce a general formulation of port-based teleportation in continuous variable systems and study in detail the N = 2 case. In particular, we interpret the resulting channel as an energy truncation and analyse the kinds of channels that can be naturally simulated after this restriction.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2025

Viral‐mediated delivery of morphogenic regulators enables leaf transformation in Sorghum bicolor (L.)

Recent advancements in monocot transformation, using leaf tissue as explant material, have expanded the number of grass species capable of transgenesis. However, the complexity of vectors and reliance on inducible excision of essential morphogenic regulators have so far limited widespread application. Plant RNA viruses, such as Foxtail Mosaic Virus (FoMV), present a unique opportunity to express morphogenic regulator genes, such as Babyboom (Bbm), Wuschel2 (Wus2), Wuschel-like homeobox protein 2a (Wox2a) and the GROWTH-REGULATING FACTOR 4 (GRF4) GRF-INTERACTING FACTOR 1 (GIF1) fusion protein transiently in leaf explant tissues. Furthermore, altruistic delivery of conventional and viral vectors could provide opportunities to simplify vectors used for leaf transformation—facilitating vector optimization and reducing reliance on morphogenic regulator gene integration. In this study, both viral and conventional T-DNA vectors were tested for their ability to promote the formation of embryonic calli, a critical step in leaf transformation protocols, using Sorghum bicolor leaf explants. Although conventional leaf transformation vectors yielded viable embryonic calli (43.2 ± 2.9%: GRF4-GIF1, 50.2 ± 3%: Bbm/Wus2), altruistic conventional vectors employing the GRF4-GIF1 morphogenic regulator resulted in improved efficiencies (61.3 ± 4.7%). Altruistic delivery was further enhanced with the use of viral vectors employing both GRF4-GIF1 and Bbm/Wus2 regulators, resulting in 75.1 ± 2.3% and 79.2 ± 2.5% embryonic calli formation, respectively. Embryonic calli generated from both conventional and viral vectors produced shoots expressing fluorescent reporters, which were confirmed using molecular analysis. This work provides an important proof-of-concept for the use of both altruistic vectors and viral-expressed morphogenic regulators for improving plant transformation.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2016

SU-F-T-601: Equivalence of CyberKnife and TrueBeam STx for Spine Irradiation

Purpose: To evaluate the equivalence of spine SBRT treatment plans created in Eclipse for the TrueBeam STx (Varian Medical System, Palo Alto, CA) compared to plans using CyberKnife and MultiPlan (Accuray, Sunnyvale, CA). Methods: CT data and contours for 23 spine SBRT patients previously treated using CyberKnife (CK) were exported from MultiPlan treatment planning system into Eclipse where they were planned using static IMRT 6MV coplanar beams. Plans were created according to the original prescription dose and fractionation schedule while limiting spinal dose according to the RTOG 0631 protocol and maintaining target coverage comparable to the original CK plans. Plans were evaluated using new conformity index (nCI), homogeneity index (HI), dose-volume histogram data, number of MU, and estimated treatment time. To ensure all Eclipse plans were deliverable, standard clinical IMRT QA was performed. The plan results were matched with their complimentary CK plans for paired statistical analysis. Results: Plans generated in Eclipse demonstrated statistically significant (p<0.01) improvements compared to complimentary CK plans in median values of maximum spinal cord dose (17.39 vs. 18.12 Gy), RTOG spinal cord constraint dose (14.50 vs. 16.93 Gy), nCI (1.28 vs. 1.54), HI (1.13 vs. 1.27), MU (3918 vs. 36416), and estimated treatment time (8 vs. 48 min). All Eclipse generated plans passed our clinically used protocols for IMRT QA. Conclusion: CK spine SBRT replanned utilizing Eclipse for LINAC delivery demonstrated dosimetric advantages. We propose improvements in plan quality metrics reviewed in this study may be attributed to dynamic MLCs that facilitate treatment of complicated geometries as well as posterior beams ideal for centrally located and/or posterior targets afforded by gantry-based RT delivery.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2023

Elsa: enhanced latent spaces for improved collider simulations

Abstract Simulations play a key role for inference in collider physics. We explore various approaches for enhancing the precision of simulations using machine learning, including interventions at the end of the simulation chain (reweighting), at the beginning of the simulation chain (pre-processing), and connections between the end and beginning (latent space refinement). To clearly illustrate our approaches, we use W + jets matrix element surrogate simulations based on normalizing flows as a prototypical example. First, weights in the data space are derived using machine learning classifiers. Then, we pull back the data-space weights to the latent space to produce unweighted examples and employ the Latent Space Refinement ( Laser ) protocol using Hamiltonian Monte Carlo. An alternative approach is an augmented normalizing flow, which allows for different dimensions in the latent and target spaces. These methods are studied for various pre-processing strategies, including a new and general method for massive particles at hadron colliders that is a tweak on the widely-used RamboOnDiet mapping. We find that modified simulations can achieve sub-percent precision across a wide range of phase space.

Nachman, Benjamin (ORCID:0000000310240932)↗
DOE OSTI2025

Data for "Viral-mediated Delivery of Morphogenic Regulators Enables Leaf Transformation in Sorghum bicolor (L.)"

Recent advancements in monocot transformation, using leaf tissue as explant material, have expanded the number of grass species capable of transgenesis. However, the complexity of vectors and reliance on inducible excision of essential morphogenic regulators have so far limited widespread application. Plant RNA viruses, such as Foxtail Mosaic Virus (FoMV), present a unique opportunity to express morphogenic regulator genes, such as Babyboom ( Bbm ), Wuschel2 ( Wus2 ), Wuschel-like homeobox protein 2a ( Wox2a ) and the GROWTH-REGULATING FACTOR 4 (GRF4) GRF-INTERACTING FACTOR 1 (GIF1) fusion protein transiently in leaf explant tissues. Furthermore, altruistic delivery of conventional and viral vectors could provide opportunities to simplify vectors used for leaf transformation—facilitating vector optimization and reducing reliance on morphogenic regulator gene integration. In this study, both viral and conventional T-DNA vectors were tested for their ability to promote the formation of embryonic calli, a critical step in leaf transformation protocols, using Sorghum bicolor leaf explants. Although conventional leaf transformation vectors yielded viable embryonic calli (43.2 ± 2.9%: GRF4-GIF1, 50.2 ± 3%: Bbm/Wus2), altruistic conventional vectors employing the GRF4-GIF1 morphogenic regulator resulted in improved efficiencies (61.3 ± 4.7%). Altruistic delivery was further enhanced with the use of viral vectors employing both GRF4-GIF1 and Bbm/Wus2 regulators, resulting in 75.1 ± 2.3% and 79.2 ± 2.5% embryonic calli formation, respectively. Embryonic calli generated from both conventional and viral vectors produced shoots expressing fluorescent reporters, which were confirmed using molecular analysis. This work provides an important proof-of-concept for the use of both altruistic vectors and viral-expressed morphogenic regulators for improving plant transformation.

gene editing↗
DOE OSTI2022

AmeriFlux US-Cst Crossett Experimental Forest

This is the AmeriFlux version of the carbon flux data for the site US-Cst Crossett Experimental Forest. Site Description - The study takes place in the Crossett Experimental Forest (CEF, 32°2′ N, 91°57′ W), which was established in 1934 with the objective of developing effective management protocols for loblolly and shortleaf pine forests in the Gulf Coastal Plain. Mean annual temperature and precipitation are 17.6 °C and 1,410 mm, respectively. Most of the soils on and near the CEF are silt loams (primarily Glossaquic Fragiudalfs). The tower is situated in the the old-growth pine management sector of the CEF, which emphasizes management for old-growth-like conditions, with the goal of emulating the structural and compositional attributes of historic forests from this region using a combination of timber harvesting, prescribed fire, and other tools. This includes periodic commercial logging of intermediate-sized loblolly pines to support further restoration treatments, such as prescribed fire, hardwood and exotic species competition control, and the increase of plant species more compatible with fire (e.g., shortleaf pine and understory grasses)

Novick, Kim↗
DOE OSTI2024

AmeriFlux FLUXNET-1F US-Cst Crossett Experimental Forest

This is the AmeriFlux Management Project (AMP) created FLUXNET-1F version of the carbon flux data for the site US-Cst Crossett Experimental Forest. This is the FLUXNET version of the carbon flux data for the site US-Cst Crossett Experimental Forest produced by applying the standard ONEFlux (1F) software. Site Description - The study takes place in the Crossett Experimental Forest (CEF, 32°2′ N, 91°57′ W), which was established in 1934 with the objective of developing effective management protocols for loblolly and shortleaf pine forests in the Gulf Coastal Plain. Mean annual temperature and precipitation are 17.6 °C and 1,410 mm, respectively. Most of the soils on and near the CEF are silt loams (primarily Glossaquic Fragiudalfs). The tower is situated in the the old-growth pine management sector of the CEF, which emphasizes management for old-growth-like conditions, with the goal of emulating the structural and compositional attributes of historic forests from this region using a combination of timber harvesting, prescribed fire, and other tools. This includes periodic commercial logging of intermediate-sized loblolly pines to support further restoration treatments, such as prescribed fire, hardwood and exotic species competition control, and the increase of plant species more compatible with fire (e.g., shortleaf pine and understory grasses)

Novick, Kim↗
DOE OSTI2013

Amorphous Alloy Membranes for High Temperature Hydrogen Separation

At the beginning of this project, thin film amorphous alloy membranes were considered a nascent but promising new technology for industrial-scale hydrogen gas separations from coal- derived syngas. This project used a combination of theoretical modeling, advanced physical vapor deposition fabricating, and laboratory and gasifier testing to develop amorphous alloy membranes that had the potential to meet Department of Energy (DOE) targets in the testing strategies outlined in the NETL Membrane Test Protocol. The project is complete with Southwest Research Institute® (SwRI®), Georgia Institute of Technology (GT), and Western Research Institute (WRI) having all operated independently and concurrently. GT studied the hydrogen transport properties of several amorphous alloys and found that ZrCu and ZrCuTi were the most promising candidates. GT also evaluated the hydrogen transport properties of V, Nb and Ta membranes coated with different transition-metal carbides (TMCs) (TM = Ti, Hf, Zr) catalytic layers by employing first-principles calculations together with statistical mechanics methods and determined that TiC was the most promising material to provide catalytic hydrogen dissociation. SwRI developed magnetron coating techniques to deposit a range of amorphous alloys onto both porous discs and tubular substrates. Unfortunately none of the amorphous alloys could be deposited without pinhole defects that undermined the selectivity of the membranes. WRI tested the thermal properties of the ZrCu and ZrNi alloys and found that under reducing environments the upper temperature limit of operation without recrystallization is ~250 °C. There were four publications generated from this project with two additional manuscripts in progress and six presentations were made at national and international technical conferences. The combination of the pinhole defects and the lack of high temperature stability make the theoretically identified most promising candidate amorphous alloys unsuitable for application as hydrogen separation membranes in coal fire systems.

08 HYDROGEN↗