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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 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

SBML Level 3: an extensible format for the exchange and reuse of biological models

Systems biology has experienced dramatic growth in the number, size, and complexity of computational models. To reproduce simulation results and reuse models, researchers must exchange unambiguous model descriptions. We review the latest edition of the Systems Biology Markup Language (SBML), a format designed for this purpose. A community of modelers and software authors developed SBML Level 3 over the past decade. Its modular form consists of a core suited to representing reaction-based models and packages that extend the core with features suited to other model types including constraint-based models, reaction-diffusion models, logical network models, and rule-based models. The format leverages two decades of SBML and a rich software ecosystem that transformed how systems biologists build and interact with models. More recently, the rise of multiscale models of whole cells and organs, and new data sources such as single-cell measurements and live imaging, has precipitated new ways of integrating data with models. We provide our perspectives on the challenges presented by these developments and how SBML Level 3 provides the foundation needed to support this evolution.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2022

Editorial: Artificial Intelligence and Machine Learning Applications in Plant Genomics and Genetics

In plants, as in other species, genotypic variation in combination with environmental variation leads to differences in the biochemical makeup of cells, measurable as molecular phenotypes. These in turn influence physiological and developmental traits such as organ formation and plant growth, and eventually traits relevant in agriculture, such as yield and stress tolerance. Thus, relating genotypes to phenotypes yields fundamental insights into the regulation of important processes in plant development and physiology, but also provides the ability to predict yield and quality traits in specific environments, which is essential in basic plant science and molecular breeding of resilient plants in changing environments.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2022

Solute- and solvent-based electromotive force cells for activity measurements of electroactive species in molten salts

A novel combination of solute- and solvent-based electrodes was used to determine the activities of NdCl 3 and GdCl 3 in molten LiCI-KCI eutectic using electromotive force measurements across a broad concentration range of dissolved electroactive species. First, an electrochemical cell using solute-based electrodes was used to define the relative activity of each species as a function of concentration and the concentration region in which Henry's law was applicable. Next, the electromotive force between a solute-based electrode with a known NdCl 3 or GdCl 3 concentration and a solvent-based electrode with a known electromotive force was measured. The solvent-based electrode potential was converted to the Lithium Eutectic Electrode (LEE) potential, which allowed the activity of dissolved NdCl 3 and GdCl 3 to be calculated at the concentrations measured using the solute-based electrodes. The described two-cell method uses electromotive force measurements to accurately determine the activity of electroactive species over a wide concentration range and provides a simple approach to closing the knowledge gap of thermochemical properties of molten salts.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

Quantitative phase measurements of human cell nuclei using X-ray ptychography

The human cell nucleus serves as an important organelle holding the genetic blueprint for life. In this work, X-ray ptychography was applied to assess the masses of human cell nuclei using its unique phase shift information. Measurements were carried out at the I13-1 beamline at the Diamond Light Source that has extremely large transverse coherence properties. Furthermore, the ptychographic diffractive imaging approach allowed imaging of large structures that gave quantitative measurements of the phase shift in 2D projections. In this paper a modified ptychography algorithm that improves the quality of the reconstruction for weak scattering samples is presented. The application of this approach to calculate the mass of several human nuclei is also demonstrated.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2023

A New Simultaneous Membrane Thickness and Catalyst Loading Measurement for Fuel Cell Proton-Exchange Assemblies by $\mathrm{IR}$ Transmission

Here, we present a study of mid-infrared (mid-IR) transmission through typical proton-exchange fuel cell and water electrolyzer catalyst-coated membrane materials, and the determination of membrane layer thickness, and catalyst layer loading, from the power of the transmitted beam. Measured membrane thicknesses lay in the range of 25-125 um, and catalyst areal loadings range from 0.05 to 0.35 mg/cm 2 . We show that the transmission spectrum correlated to membrane thickness and catalyst loading values separately, and also used a mathematical model to calculate both quantities simultaneously, from a single measurement of transmission. Measurements were carried out using a Fourier-transform infrared (FTIR) spectrometer, in specular transmission mode, in the wavelength range of 3-13 um (3333-770 cm -1 ). We discuss the potential application of this method to the development of roll-to-roll manufacturing full-area-scanning quality inspection of catalyst-coated membrane (CCM) materials.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2022

Reference Cell Performance and Modeling on a One-Axis Tracking Surface: Preprint

Performance of five silicon-based reference cells is examined on a single-axis tracking surface. The reference cells' output are modeled using one-minute sampled spectral irradiance and reference cell temperature measurements. The model also incorporates spectral responsivity data for the reference cell. The transmission of light through the glazing multiplies the sum over all appropriate wavelengths of temperature adjusted reference cell responsivity times the measured spectral irradiance. Modeled reference cell output is compared with measured reference cell output under clear sky and totally cloudy sky conditions. For each reference cell the ratio of modeled to measured output varies by less than 2% over the year.

modeling↗
DOE OSTI2020

Theory and Practice in Measuring In-Vitro Extensibility of Growing Plant Cell Walls

This chapter summarizes four extensometer techniques for measuring cell wall extensibility in vitro and discusses how the results of these methods relate to the concept and ideal measurement of cell wall extensibility in the context of plant cell growth. These in-vitro techniques are particularly useful for studies of the molecular basis of cell wall extension. Measurements of breaking strength, elastic compliance and plastic compliance may be informative about changes in cell wall structure, whereas measurements of wall stress relaxation and creep are sensitive to both changes in wall structure and wall-loosening processes, such as those mediated by expansins and some lytic enzymes. As a result, a combination of methods is needed to obtain a broader view of cell wall behavior and properties connected with the concept of cell wall extensibility.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Operando carbon corrosion measurements in fuel cells using boron-doped carbon supports

Carbonaceous materials are the most common catalyst supports in proton exchange membrane fuel cell (PEMFCs), yet their corrosion is one of the limiting factors in achieving high durability. Herein, we doped carbon supports with boron (B) to increase the corrosion-resistance of the support. Two types of B-doped carbons were synthesized and studied as platinum support materials. Further, they varied in their morphologies, surface areas, and the types of boron species. The durability of Pt/B-doped carbon catalysts was investigated using the US-DOE catalysts’ supports accelerated stress test (AST) and a mass-spectrometer connected to the fuel cell effluent stream to quantify the mass of corroded carbon support in operando. The addition of boron to the carbon increased the stability of Pt catalysts in long-term usage of PEMFC. After 4000 AST cycles, more than 50% of initial current density was preserved for the boron-containing systems, while less than 30% of it remained with Vulcan carbon (Pt/V). Also, the Pt/B-doped carbon samples demonstrated better electrochemical active surface area (ECSA) stability when compared to Pt/V. Carbon loss measurements showed that B-doped carbons have higher resistance to electrochemical corrosion than unmodified carbon. Specifically, the substitutional boron-doped carbon demonstrated an extremely high stability and low corrosion rate.

25 ENERGY STORAGE↗
DOE OSTI2020

Surface Photovoltage Measurement of Perovskite Solar Cells to Screen Carrier Selective Contacts

SPV measurement through the Kelvin probe method is described. Silicon heterojunction structures show the maximum SPV of 700 V. Measurement on perovskite structures, and the results suggest adding BCP with C60 enhances the selectivity of C60 electron contact. Furthermore, PTAA and PTAA/PFN have similar selectivity but NiO x is poorly selective. SPV is an easy way to provide a relative comparison between various cell structures and contact layers to determine the relative extractable Voc and properties of the contact layer (selectivity, passivation) limiting the efficiency.

Kavadiya, Shalinee↗
DOE OSTI2024

CSD 2078665: Experimental Crystal Structure Determination

An entry from the Inorganic Crystal Structure Database, the world’s repository for inorganic crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the joint CCDC and FIZ Karlsruhe Access Structures service and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Cell Parameters↗
DOE OSTI2024

CSD 2312746: Experimental Crystal Structure Determination

An entry from the Inorganic Crystal Structure Database, the world’s repository for inorganic crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the joint CCDC and FIZ Karlsruhe Access Structures service and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Cell Parameters↗
DOE OSTI2025

CCDC 2352354: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Cell Parameters↗
DOE OSTI2025

CCDC 2352355: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Cell Parameters↗