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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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DOE OSTI2024

Light-induced H 2 generation in a photosystem I-O 2 -tolerant [FeFe] hydrogenase nanoconstruct

The fusion of hydrogenases and photosynthetic reaction centers (RCs) has proven to be a promising strategy for the production of sustainable biofuels. Type I (iron-sulfur-containing) RCs, acting as photosensitizers, are capable of promoting electrons to a redox state that can be exploited by hydrogenases for the reduction of protons to dihydrogen (H 2 ). While both [FeFe] and [NiFe] hydrogenases have been used successfully, they tend to be limited due to either O 2 sensitivity, binding specificity, or H 2 production rates. In this study, we fuse a peripheral (stromal) subunit of Photosystem I (PS I), PsaE, to an O 2 -tolerant [FeFe] hydrogenase from Clostridium beijerinckii using a flexible [GGS] 4 linker group (CbHydA1-PsaE). We demonstrate that the CbHydA1 chimera can be synthetically activated in vitro to show bidirectional activity and that it can be quantitatively bound to a PS I variant lacking the PsaE subunit. When illuminated in an anaerobic environment, the nanoconstruct generates H 2 at a rate of 84.9 ± 3.1 µmol H 2 mg chl –1 h –1 . Further, when prepared and illuminated in the presence of O 2 , the nanoconstruct retains the ability to generate H 2 , though at a diminished rate of 2.2 ± 0.5 µmol H 2 mg chl –1 h –1 . This demonstrates not only that PsaE is a promising scaffold for PS I-based nanoconstructs, but the use of an O 2 -tolerant [FeFe] hydrogenase opens the possibility for an in vivo H 2 generating system that can function in the presence of O 2 .

Hydrogenase↗
DOE OSTI2024

Measuring Economy-Wide Circularity of the United States: An Input-Output Model in Mass Units

The ideal of creating closed material cycles by transforming the way we make, use and repurpose goods has become known as the circular economy. Besides its visionary appeal, material efficiency strategies central to circular economy can allow us to meet decarbonization goals that are otherwise out of reach. Production of basic materials such as cement, iron and steel and petrochemicals is one of the largest drivers of greenhouse gas emissions. Measuring circularity, and understanding its relationship with other sustainability metrics, however, is still difficult due to lack of data in mass units covering the entire economic system. Input-output (I-O) tables were originally created as a means of tracking the monetary flows that represent exchanges of goods and services within an economy, but have found additional uses in life cycle assessment and material flow accounts. In the traditional approach of environmentally extended I-O tables, emissions and energy data augment monetary flows. This approach can lead to price effects that distort physical quantities. Also, circular economy strategies and their goals relate to mass, not monetary flows. Therefore, it is best to simulate them using physical quantities. With these issues in mind, we have developed I-O tables in mass units to measure the flow of goods in the U.S. economy. This allows us to better measure how circular the economy really is, and how policy changes to affect this circularity may also affect decarbonization goals. Improving knowledge of these linkages could allow manufacturers to make changes in their production to achieve their sustainability and decarbonization targets. Our tool also provides a standard approach and public repository for data in physical units, making such data more available, useful, and meaningful. Following an established set of material flow metrics used by the European Union, we have used our tool to calculate material footprints over time differentiated by oil and gas versus other extractive industries. This approach also shows the relative trade balances of the U.S. in materials. We have developed a case study for the iron and steel sector, showing how different decarbonization scenarios affect not only economy-wide greenhouse gas emissions, but also total material use.

circular economy↗
DOE OSTI2022

Updated Economic Model for Estimation of GDP Losses in the MACCS Offsite Consequence Analysis Code RDEIM Model Report for MACCS v4.2

This report updates the Regional Disruption Economic Impact Model (RDEIM) GDP-based model described in Bixler et al. (2020) used in the MACCS accident consequence analysis code. MACCS is the U.S. Nuclear Regulatory Commission (NRC) used to perform probabilistic health and economic consequence assessments for atmospheric releases of radionuclides. It is also used by international organizations, both reactor owners and regulators. It is intended and most commonly used for hypothetical accidents that could potentially occur in the future rather than to evaluate past accidents or to provide emergency response during an ongoing accident. It is designed to support probabilistic risk and consequence analyses and is used by the NRC, U.S. nuclear licensees, the Department of Energy, and international vendors, licensees, and regulators. The update of the RDEIM model in version 4.2 expresses the national recovery calculation explicitly, rather than implicitly as in the previous version. The calculation of the total national GDP losses remains unchanged. However, anticipated gains from recovery are now allocated across all the GDP loss types – direct, indirect, and induced – whereas in version 4.1, all recovery gains were accounted for in the indirect loss type. To achieve this, we’ve introduced new methodology to streamline and simplify the calculation of all types of losses and recovery. In addition, RDEIM includes other kinds of losses, including tangible wealth. This includes loss of tangible assets (e.g., depreciation) and accident expenditures (e.g., decontamination). This document describes the updated RDEIM economic model and provides examples of loss and recovery calculation, results analysis, and presentation. Changes to the tangible cost calculation and accident expenditures are described in section 2.2. The updates to the RDEIM input-output (I-O) model are not expected to affect the final benchmark results Bixler et al. (2020), as the RDEIM calculation for the total national GDP losses remains unchanged. The reader is referred to the MACCS revision history for other cost modelling changes since version 4.0 that may affect the benchmark. RDEIM has its roots in a code developed by Sandia National Laboratories for the Department of Homeland Security to estimate short-term losses from natural and manmade accidents, called the Regional Economic Accounting analysis tool (REAcct). This model was adapted and modified for MACCS. It is based on I-O theory, which is widely used in economic modeling. It accounts for direct losses to a disrupted region affected by an accident, indirect losses to the national economy due to disruption of the supply chain, and induced losses from reduced spending by displaced workers. RDEIM differs from REAcct in in its treatment and estimation of indirect loss multipliers, elimination of double-counting associated with inter-industry trade in the affected area, and that it is intended to be used for extended periods that can occur from a major nuclear reactor accident, such as the one that occurred at the Fukushima Daiichi site in Japan. Most input-output models do not account for economic adaptation and recovery, and in this regard RDEIM differs from its parent, REAcct, because it allows for a user-definable national recovery period. Implementation of a recovery period was one of several recommendations made by an independent peer review panel to ensure that RDEIM is state-of-practice. For this and several other reasons, RDEIM differs from REAcct.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2020

Materials Data on IO2 by Materials Project

O2I crystallizes in the monoclinic P2_1/c space group. The structure is two-dimensional and consists of one O2I sheet oriented in the (1, 0, 0) direction. there are four inequivalent O sites. In the first O site, O is bonded in a distorted single-bond geometry to three I atoms. There are a spread of O–I bond distances ranging from 1.85–2.74 Å. In the second O site, O is bonded in a distorted bent 150 degrees geometry to two equivalent I atoms. There are one shorter (1.81 Å) and one longer (2.58 Å) O–I bond lengths. In the third O site, O is bonded in a bent 120 degrees geometry to two I atoms. There are one shorter (1.94 Å) and one longer (2.13 Å) O–I bond lengths. In the fourth O site, O is bonded in a bent 120 degrees geometry to two I atoms. There are one shorter (1.94 Å) and one longer (2.17 Å) O–I bond lengths. There are two inequivalent I sites. In the first I site, I is bonded in a 2-coordinate geometry to four O atoms. In the second I site, I is bonded to five O atoms to form distorted corner-sharing IO5 square pyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on I2O5 by Materials Project

I2O5 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to two I5+ atoms. There is one shorter (1.95 Å) and one longer (2.00 Å) O–I bond length. In the second O2- site, O2- is bonded in a single-bond geometry to one I5+ atom. The O–I bond length is 1.79 Å. In the third O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent I5+ atoms. There are one shorter (1.84 Å) and one longer (2.43 Å) O–I bond lengths. In the fourth O2- site, O2- is bonded in a distorted single-bond geometry to two I5+ atoms. There are one shorter (1.80 Å) and one longer (2.56 Å) O–I bond lengths. In the fifth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent I5+ atoms. There are one shorter (1.87 Å) and one longer (2.27 Å) O–I bond lengths. There are two inequivalent I5+ sites. In the first I5+ site, I5+ is bonded to five O2- atoms to form distorted corner-sharing IO5 square pyramids. In the second I5+ site, I5+ is bonded in a 5-coordinate geometry to four O2- atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on IO3 by Materials Project

IO3 crystallizes in the triclinic P-1 space group. The structure is two-dimensional and consists of one IO3 sheet oriented in the (1, 0, 0) direction. there are six inequivalent O sites. In the first O site, O is bonded in a water-like geometry to two equivalent I atoms. Both O–I bond lengths are 1.99 Å. In the second O site, O is bonded in a bent 120 degrees geometry to two I atoms. There is one shorter (1.96 Å) and one longer (2.01 Å) O–I bond length. In the third O site, O is bonded in a single-bond geometry to one I atom. The O–I bond length is 1.76 Å. In the fourth O site, O is bonded in a bent 120 degrees geometry to two I atoms. There are one shorter (1.98 Å) and one longer (2.02 Å) O–I bond lengths. In the fifth O site, O is bonded in a distorted bent 120 degrees geometry to two I atoms. There are one shorter (1.84 Å) and one longer (2.35 Å) O–I bond lengths. In the sixth O site, O is bonded in a distorted bent 120 degrees geometry to two I atoms. There are one shorter (1.84 Å) and one longer (2.30 Å) O–I bond lengths. There are two inequivalent I sites. In the first I site, I is bonded to six O atoms to form IO6 octahedra that share corners with four equivalent IO5 square pyramids and an edgeedge with one IO6 octahedra. In the second I site, I is bonded to five O atoms to form distorted corner-sharing IO5 square pyramids. The corner-sharing octahedra tilt angles range from 51–52°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on IO3 by Materials Project

IO3 crystallizes in the orthorhombic P2_12_12_1 space group. The structure is three-dimensional. there are three inequivalent O sites. In the first O site, O is bonded in a 2-coordinate geometry to two equivalent I atoms. There are one shorter (1.85 Å) and one longer (2.40 Å) O–I bond lengths. In the second O site, O is bonded in a distorted bent 150 degrees geometry to two equivalent I atoms. There are one shorter (1.87 Å) and one longer (2.20 Å) O–I bond lengths. In the third O site, O is bonded in a distorted bent 120 degrees geometry to two equivalent I atoms. There are one shorter (1.89 Å) and one longer (2.20 Å) O–I bond lengths. I is bonded to six O atoms to form distorted corner-sharing IO6 octahedra. The corner-sharing octahedra tilt angles range from 45–47°.

36 MATERIALS SCIENCE↗