Thermal stability and structural studies on the mixtures of Mg(BH 4 ) 2 and glymes
Understanding speciation, stability, and degradation of Mg(BH 4 ) 2 ·glymes by powder XRD, DSC–TGA & TDS-MS.
08 HYDROGEN↗
SEARCH · Engineering Papers
Results for “BH”
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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Labilized ligands under ultra-confinement: a solid-state 2 H NMR investigation of Ln(BH 4 ) 2 (THF) 2 /HY 30
Variable-temperature 2 H NMR reveals that the THF ligands are highly labile in Ln(BH 4 ) 2 (THF) 2 /HY 30 , undergoing exchange between Ln sites under confinement via low-coordinate intermediates. Potency in catalytic C–H borylation likely emerges from access to highly electrophilic, electronically unsaturated species.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Interpolation data transfer between the models before and after a partial drawdown leach in BH
It has been recognized that as cavern operations become more frequent due to oil sales, field conditions may arise which require a faster turnaround time of analysis to address potential cavern impacts. This letter describes attempts to implement a strategy of transferring an intermediate solution of a Big Hill (BH) geomechanical model from a previous finite element mesh with a specified cavern geometry, to a new mesh with a new cavern geometry created by leaching from an oil sale operation.
02 PETROLEUM↗
Sampling and Analysis Plan for Partial Closure of Solid Waste Management Unit #16; Addendum Part I for Delineating BH-056
On July 11, 2022, Sandia National Laboratories in California (SNL/CA) submitted a Response to Regional Water Quality Control Board Comments on Soil Sampling Results for Closure of a Portion of SWMU #16 in response to the February 16,2022 San Francisco Bay Regional Water Quality Control Board’s (SFRWQCB) letter requesting supporting information for the recommended closure of 7,700 linear feet of abandoned sewer lines. On August 18, 2022, SFRWQCB further requested a Sampling and Analysis Plan (SAP) for additional “step-out” sampling to delineate the potential presence of benzidine near borehole BH-056, which is located near the former sewer line. SNL/CA is in the process of contracting Weiss Associates (Weiss) to perform and oversee the boring, sampling, analysis, and report development to determine the potential presence and extent of benzidine. This document outlines the work that is anticipated, including the development of the SAP, to complete the investigation and submit a final report to the SFRWQCB. The work proposed by Weiss provides an estimated schedule for completing the investigation and developing the addendum Part II SAP for the project. In addition, Weiss provided a preliminary estimate of the sample locations (see Attachment A) which serve as addendum Part I of the SAP requested by the SFRWQCB. The contractor will submit the addendum Part II SAP, to satisfy the SFRWQCB requirement, before proceeding with any work.
54 ENVIRONMENTAL SCIENCES↗
Soil Sampling Results for Delineating BH-056 for Partial Closure of Solid Waste Management Unit #16
The U.S. Department of Energy/National Nuclear Security Administration (DOE/NNSA) and National Technology & Engineering Solutions of Sandia, LLC (NTESS), the management and operating contractor for Sandia National Laboratories/California (SNL/CA), has prepared this addendum to Soil Sampling Results for Closure of a Portion of Solid Waste Management Unit #16 to report the results of additional soil sampling relating to the closure of a portion of Solid Waste Management Unit (SWMU) #16. This additional sampling was in response to a request by the San Francisco Bay Regional Water Quality Control Board (SFRWQCB) in their letters dated February 16 and August 18, 2022 relating to the detection of the benzidine above the defined project action level in a soil sample collected adjacent to the sanitary sewer line in borehole BH-056 (SFRWQCB, 2022A; 2022b).
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
Materials Data on Ca(BH)2 by Materials Project
CaB2H2 crystallizes in the orthorhombic Pnma space group. The structure is two-dimensional and consists of two CaB2H2 sheets oriented in the (0, 0, 1) direction. Ca2+ is bonded in a distorted single-bond geometry to five H1- atoms. There are a spread of Ca–H bond distances ranging from 2.23–2.72 Å. There are two inequivalent B sites. In the first B site, B is bonded in a distorted single-bond geometry to three H1- atoms. There is one shorter (1.40 Å) and two longer (1.79 Å) B–H bond length. In the second B site, B is bonded in a distorted single-bond geometry to one H1- atom. The B–H bond length is 1.25 Å. There are two inequivalent H1- sites. In the first H1- site, H1- is bonded in a 3-coordinate geometry to one Ca2+ and two B atoms. In the second H1- site, H1- is bonded to four equivalent Ca2+ and two equivalent B atoms to form a mixture of distorted edge, corner, and face-sharing HCa4B2 octahedra. The corner-sharing octahedral tilt angles are 77°.
36 MATERIALS SCIENCE↗
Materials Data on Ca(BH)2 by Materials Project
CaB2H2 crystallizes in the trigonal P-3m1 space group. The structure is two-dimensional and consists of one CaB2H2 sheet oriented in the (0, 0, 1) direction. Ca2+ is bonded in a distorted hexagonal planar geometry to six equivalent H1- atoms. All Ca–H bond lengths are 2.10 Å. B is bonded in a single-bond geometry to one H1- atom. The B–H bond length is 1.24 Å. H1- is bonded to three equivalent Ca2+ and one B atom to form a mixture of edge and corner-sharing HCa3B tetrahedra.
36 MATERIALS SCIENCE↗
Materials Data on Ca(BH)2 by Materials Project
CaB2H2 crystallizes in the orthorhombic Cmc2_1 space group. The structure is one-dimensional and consists of four CaB2H2 ribbons oriented in the (1, 0, 0) direction. Ca2+ is bonded in a 4-coordinate geometry to four H1- atoms. There are two shorter (2.21 Å) and two longer (2.24 Å) Ca–H bond lengths. There are two inequivalent B sites. In the first B site, B is bonded in a distorted single-bond geometry to one H1- atom. The B–H bond length is 1.25 Å. In the second B site, B is bonded in a distorted single-bond geometry to one H1- atom. The B–H bond length is 1.26 Å. There are two inequivalent H1- sites. In the first H1- site, H1- is bonded in a distorted trigonal non-coplanar geometry to two equivalent Ca2+ and one B atom. In the second H1- site, H1- is bonded in a 3-coordinate geometry to two equivalent Ca2+ and one B atom.
36 MATERIALS SCIENCE↗
Materials Data on BH by Materials Project
Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations
36 MATERIALS SCIENCE↗
Using ISS Telescopes for Electromagnetic Follow-up of Gravitational Wave Detections of NS-NS and NS-BH Mergers
The International Space Station offers a unique platform for rapid and inexpensive deployment of space telescopes. A scientific opportunity of great potential later this decade is the use of telescopes for the electromagnetic follow-up of ground-based gravitational wave detections of neutron star and black hole mergers. We describe this possibility for OpTIIX, an ISS technology demonstration of a 1.5 m diffraction limited optical telescope assembled in space, and ISS-Lobster, a wide-field imaging X-ray telescope now under study as a potential NASA mission. Both telescopes will be mounted on pointing platforms, allowing rapid positioning to the source of a gravitational wave event. Electromagnetic follow-up rates of several per year appear likely, offering a wealth of complementary science on the mergers of black holes and neutron stars.
NS-NS and NS-BH mergers↗
Search for single vector-like $B$ quark production and decay via $B$ → $bH$($b\overline{b}$) in $pp$ collisions at $\sqrt{s}$ = 13 TeV with the ATLAS detector
A search is presented for single production of a vector-like B quark decaying into a Standard Model b-quark and a Standard Model Higgs boson, which decays into a $b\overline{b}$ pair. The search is carried out in 139 fb -1 of $\sqrt{s}$ = 13 TeV proton-proton collision data collected by the ATLAS detector at the LHC between 2015 and 2018. No significant deviation from the Standard Model background prediction is observed, and mass-dependent exclusion limits at the 95% confidence level are set on the resonance production cross-section in several theoretical scenarios determined by the couplings c W , c Z and c H between the B quark and the Standard Model W, Z and Higgs bosons, respectively. For a vector-like B occurring as an isospin singlet, the search excludes values of c W greater than 0.45 for a B resonance mass (m B ) between 1.0 and 1.2 TeV. For 1.2 TeV < m B < 2.0 TeV, c W values larger than 0.50–0.65 are excluded. If the B occurs as part of a (B, Y) doublet, the smallest excluded c Z coupling values range between 0.3 and 0.5 across the investigated resonance mass range 1.0 TeV < m B < 2.0 TeV.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Superconductivity in CH 4 and BH – 4 containing compounds derived from the high-pressure superhydrides
Inspired by the synthesis of the high-pressure Fm3m LaH 10 superconducting superhydride, systematic density functional theory (DFT) calculations are performed to study ternaries that could be derived from it by replacing two of the hydrogen atoms with boron or carbon and varying the identity of the electropositive element. Though many of the resulting alkali-metal and alkaline-earth MC 2 H 8 phases are predicted to be dynamically stable at mild pressures, their superconducting critical temperatures (T c s) are low because their metallicity results from the filling of an electride-like band. Substitution with a trivalent element leads to phases with substantial metal d- character at the Fermi level whose T c s are typically above 40 K. Here, among the MB 2 H 8 phases examined, KB 2 H 8 , RbB 2 H 8 and CsB 2 H 8 are predicted to be dynamically stable at very mild pressures, and their stability is rationalized by a DFT-Chemical Pressure analysis that elucidates the role of the M atom size. Quantum anharmonic effects strongly affect the properties of KB 2 H 8 , the highest predicted T c compound, near 10 GPa, but molecular dynamics simulations reveal it would decompose below its T c at this pressure. Nonetheless, at ca. 50 GPa KB 2 H 8 is predicted to be thermally stable with a superconducting figure of merit surpassing that of the recently synthesized LaBeH 8 .
36 MATERIALS SCIENCE↗
From Carbene-Dithiolene Zwitterion Mediated B–H Bond Activation to BH 3 ·SMe 2 -Assisted Boron–Boron Bond Formation
Not Available
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Thermal conversion of unsolvated Mg(B3H8)2 to BH4- in the presence of MgH2
In the search for energy storage materials, metal octahydrotriborates, M(B3H8)n, n=1,2, are promising candidates but their synthesis suffers from residual solvents which tend to interact and greatly alter their decomposition mechanism. Therefore, we studied the thermal conversion of unsolvated Mg(B3H8)2 to BH4 -: as synthesized, and in the presence of MgH2. The conversion of our unsolvated Mg(B3H8)2 starts at ~100°C and yields ~22 wt% of BH4 - along with the formation of (closo-hydro)borates and volatile boranes. This loss of boron (B) is a sign of poor cyclability of the system. However, the addition of MgH2 to unsolvated Mg(B3H8)2 drastically increases the thermal conversion to 85-88wt% of BH4 - while simultaneously decreasing the amounts of B-losses. Our results strongly indicate that the presence of activated MgH2 substantially decreases the formation of (closohydro) borates and provides the necessary H2 for the B3H8-to-BH4 conversion. This is the first report of a metal octahydrotriborate system to selectively convert to BH4 - under moderate conditions of temperature (200°C) in less than 1h, making the MgB3H8-MgH2 system very promising for energy storage applications.
Gigante, Angelina↗
Reactive Vapor-Phase Additives toward Destabilizing γ-Mg(BH 4 ) 2 for Improved Hydrogen Release
Not Available
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗