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DOE OSTI2020

Materials Data on Tl2Mo2P2O11 by Materials Project

Mo2Tl2P2O11 crystallizes in the monoclinic P2_1 space group. The structure is three-dimensional. there are four inequivalent Mo5+ sites. In the first Mo5+ site, Mo5+ is bonded to six O2- atoms to form distorted MoO6 octahedra that share a cornercorner with one MoO6 octahedra, corners with four PO4 tetrahedra, and an edgeedge with one TlO8 hexagonal bipyramid. The corner-sharing octahedral tilt angles are 35°. There are a spread of Mo–O bond distances ranging from 1.74–2.23 Å. In the second Mo5+ site, Mo5+ is bonded to six O2- atoms to form distorted MoO6 octahedra that share a cornercorner with one MoO6 octahedra, corners with four PO4 tetrahedra, and an edgeedge with one TlO8 hexagonal bipyramid. The corner-sharing octahedral tilt angles are 35°. There are a spread of Mo–O bond distances ranging from 1.74–2.24 Å. In the third Mo5+ site, Mo5+ is bonded to six O2- atoms to form MoO6 octahedra that share a cornercorner with one TlO8 hexagonal bipyramid, a cornercorner with one MoO6 octahedra, corners with four PO4 tetrahedra, and an edgeedge with one TlO8 hexagonal bipyramid. The corner-sharing octahedral tilt angles are 35°. There are a spread of Mo–O bond distances ranging from 1.75–2.16 Å. In the fourth Mo5+ site, Mo5+ is bonded to six O2- atoms to form MoO6 octahedra that share a cornercorner with one TlO8 hexagonal bipyramid, a cornercorner with one MoO6 octahedra, corners with four PO4 tetrahedra, and an edgeedge with one TlO8 hexagonal bipyramid. The corner-sharing octahedral tilt angles are 35°. There are a spread of Mo–O bond distances ranging from 1.75–2.17 Å. There are four inequivalent Tl1+ sites. In the first Tl1+ site, Tl1+ is bonded to eight O2- atoms to form distorted TlO8 hexagonal bipyramids that share corners with two MoO6 octahedra, corners with two PO4 tetrahedra, and edges with four MoO6 octahedra. The corner-sharing octahedral tilt angles are 64°. There are a spread of Tl–O bond distances ranging from 2.79–2.99 Å. In the second Tl1+ site, Tl1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Tl–O bond distances ranging from 2.87–3.40 Å. In the third Tl1+ site, Tl1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Tl–O bond distances ranging from 2.84–3.40 Å. In the fourth Tl1+ site, Tl1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Tl–O bond distances ranging from 2.95–3.23 Å. There are four inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four MoO6 octahedra. The corner-sharing octahedra tilt angles range from 42–47°. There is two shorter (1.55 Å) and two longer (1.57 Å) P–O bond length. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four MoO6 octahedra. The corner-sharing octahedra tilt angles range from 42–48°. There is three shorter (1.55 Å) and one longer (1.58 Å) P–O bond length. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one TlO8 hexagonal bipyramid and corners with four MoO6 octahedra. The corner-sharing octahedra tilt angles range from 50–51°. There is one shorter (1.55 Å) and three longer (1.56 Å) P–O bond length. In the fourth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one TlO8 hexagonal bipyramid and corners with four MoO6 octahedra. The corner-sharing octahedra tilt angles range from 49–51°. There is one shorter (1.55 Å) and three longer (1.56 Å) P–O bond length. There are twenty-two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Mo5+, one Tl1+, and one P5+ atom. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Mo5+, one Tl1+, and one P5+ atom. In the third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Mo5+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to one Mo5+, one Tl1+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to one Mo5+, one Tl1+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to one Mo5+, one Tl1+, and one P5+ atom. In the seventh O2- site, O2- is bonded in a distorted single-bond geometry to one Mo5+ and three Tl1+ atoms. In the eighth O2- site, O2- is bonded in a single-bond geometry to one Mo5+ and three Tl1+ atoms. In the ninth O2- site, O2- is bonded in a 1-coordinate geometry to one Mo5+, one Tl1+, and one P5+ atom. In the tenth O2- site, O2- is bonded in a 1-coordinate geometry to one Mo5+, one Tl1+, and one P5+ atom. In the eleventh O2- site, O2- is bonded in a 1-coordinate geometry to one Mo5+, two Tl1+, and one P5+ atom. In the twelfth O2- site, O2- is bonded in a 1-coordinate geometry to one Mo5+, two Tl1+, and one P5+ atom. In the thirteenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two Mo5+ and one Tl1+ atom. In the fourteenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two Mo5+ and one Tl1+ atom. In the fifteenth O2- site, O2- is bonded in a 1-coordinate geometry to one Mo5+, two Tl1+, and one P5+ atom. In the sixteenth O2- site, O2- is bonded in a 1-coordinate geometry to one Mo5+, two Tl1+, and one P5+ atom. In the seventeenth O2- site, O2- is bonded in a 1-coordinate geometry to one Mo5+, one Tl1+, and one P5+ atom. In the eighteenth O2- site, O2- is bonded in a 1-coordinate geometry to one Mo5+, one Tl1+, and one P5+ atom. In the nineteenth O2- site, O2- is bonded in a single-bond geometry to one Mo5+ and two Tl1+ atoms. In the twentieth O2- site, O2- is bonded in a single-bond geometry to one Mo5+ and two Tl1+ atoms. In the twenty-first O2- site, O2- is bonded in a 1-coordinate geometry to one Mo5+, two Tl1+, and one P5+ atom. In the twenty-second O2- site, O2- is bonded in a 1-coordinate geometry to one Mo5+, two Tl1+, and one P5+ atom.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on Tl2CrO4 by Materials Project

Tl2CrO4 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent Cr6+ sites. In the first Cr6+ site, Cr6+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of Cr–O bond distances ranging from 1.66–1.68 Å. In the second Cr6+ site, Cr6+ is bonded in a tetrahedral geometry to four O2- atoms. There is one shorter (1.66 Å) and three longer (1.68 Å) Cr–O bond length. There are four inequivalent Tl1+ sites. In the first Tl1+ site, Tl1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Tl–O bond distances ranging from 2.88–3.52 Å. In the second Tl1+ site, Tl1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Tl–O bond distances ranging from 2.77–3.23 Å. In the third Tl1+ site, Tl1+ is bonded in a 1-coordinate geometry to nine O2- atoms. There are a spread of Tl–O bond distances ranging from 2.68–3.34 Å. In the fourth Tl1+ site, Tl1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Tl–O bond distances ranging from 2.75–3.39 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to one Cr6+ and four Tl1+ atoms. In the second O2- site, O2- is bonded in a single-bond geometry to one Cr6+ and five Tl1+ atoms. In the third O2- site, O2- is bonded in a distorted single-bond geometry to one Cr6+ and four Tl1+ atoms. In the fourth O2- site, O2- is bonded in a single-bond geometry to one Cr6+ and five Tl1+ atoms. In the fifth O2- site, O2- is bonded in a distorted single-bond geometry to one Cr6+ and four Tl1+ atoms. In the sixth O2- site, O2- is bonded in a distorted single-bond geometry to one Cr6+ and four Tl1+ atoms.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on PrTl(SO5)2 by Materials Project

PrTl(SO5)2 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Pr is bonded in a 7-coordinate geometry to eight O atoms. There are a spread of Pr–O bond distances ranging from 2.39–2.99 Å. Tl is bonded in a distorted bent 120 degrees geometry to two O atoms. There are one shorter (2.69 Å) and one longer (2.70 Å) Tl–O bond lengths. There are two inequivalent S sites. In the first S site, S is bonded in a tetrahedral geometry to four O atoms. There are a spread of S–O bond distances ranging from 1.48–1.50 Å. In the second S site, S is bonded in a tetrahedral geometry to four O atoms. There are a spread of S–O bond distances ranging from 1.45–1.52 Å. There are ten inequivalent O sites. In the first O site, O is bonded in a distorted single-bond geometry to one Pr, one Tl, and one S atom. In the second O site, O is bonded in a single-bond geometry to one S atom. In the third O site, O is bonded in a water-like geometry to one Pr and one S atom. In the fourth O site, O is bonded in a linear geometry to one Pr and one S atom. In the fifth O site, O is bonded in a distorted single-bond geometry to one Pr and one S atom. In the sixth O site, O is bonded in a distorted single-bond geometry to one Pr and one O atom. The O–O bond length is 1.24 Å. In the seventh O site, O is bonded in a bent 150 degrees geometry to one Pr and one S atom. In the eighth O site, O is bonded in a distorted single-bond geometry to one O atom. In the ninth O site, O is bonded in a bent 150 degrees geometry to one Pr and one S atom. In the tenth O site, O is bonded in a distorted single-bond geometry to one Pr, one Tl, and one S atom.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on TlBiSe2 by Materials Project

TlBiSe2 is Caswellsilverite-like structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. there are four inequivalent Tl1+ sites. In the first Tl1+ site, Tl1+ is bonded to six Se2- atoms to form distorted TlSe6 octahedra that share a cornercorner with one BiSe6 octahedra, corners with five TlSe6 octahedra, edges with four equivalent BiSe6 octahedra, and edges with eight TlSe6 octahedra. The corner-sharing octahedra tilt angles range from 0–16°. There are a spread of Tl–Se bond distances ranging from 2.87–3.48 Å. In the second Tl1+ site, Tl1+ is bonded to six Se2- atoms to form TlSe6 octahedra that share a cornercorner with one BiSe6 octahedra, corners with five TlSe6 octahedra, and edges with twelve TlSe6 octahedra. The corner-sharing octahedra tilt angles range from 0–5°. There are a spread of Tl–Se bond distances ranging from 2.91–3.44 Å. In the third Tl1+ site, Tl1+ is bonded to six Se2- atoms to form a mixture of corner and edge-sharing TlSe6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. There are a spread of Tl–Se bond distances ranging from 3.07–3.11 Å. In the fourth Tl1+ site, Tl1+ is bonded to six Se2- atoms to form a mixture of corner and edge-sharing TlSe6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (3.09 Å) and two longer (3.14 Å) Tl–Se bond lengths. There are five inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded to six Se2- atoms to form distorted BiSe6 octahedra that share a cornercorner with one TlSe6 octahedra, corners with five BiSe6 octahedra, edges with four equivalent TlSe6 octahedra, and edges with eight BiSe6 octahedra. The corner-sharing octahedra tilt angles range from 0–16°. There are a spread of Bi–Se bond distances ranging from 2.62–3.48 Å. In the second Bi3+ site, Bi3+ is bonded to six Se2- atoms to form BiSe6 octahedra that share a cornercorner with one TlSe6 octahedra, corners with five BiSe6 octahedra, and edges with twelve BiSe6 octahedra. The corner-sharing octahedra tilt angles range from 0–8°. There are a spread of Bi–Se bond distances ranging from 2.84–3.20 Å. In the third Bi3+ site, Bi3+ is bonded to six Se2- atoms to form a mixture of corner and edge-sharing BiSe6 octahedra. The corner-sharing octahedra tilt angles range from 0–4°. There are a spread of Bi–Se bond distances ranging from 2.89–3.13 Å. In the fourth Bi3+ site, Bi3+ is bonded to six Se2- atoms to form a mixture of corner and edge-sharing BiSe6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (3.02 Å) and four longer (3.09 Å) Bi–Se bond lengths. In the fifth Bi3+ site, Bi3+ is bonded to six Se2- atoms to form a mixture of corner and edge-sharing BiSe6 octahedra. The corner-sharing octahedra tilt angles range from 0–4°. There are a spread of Bi–Se bond distances ranging from 2.89–3.13 Å. There are eight inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to six Bi3+ atoms to form SeBi6 octahedra that share corners with six SeBi6 octahedra and edges with twelve SeTlBi5 octahedra. The corner-sharing octahedra tilt angles range from 0–8°. In the second Se2- site, Se2- is bonded to six Bi3+ atoms to form SeBi6 octahedra that share corners with six SeTlBi5 octahedra and edges with twelve SeBi6 octahedra. The corner-sharing octahedra tilt angles range from 0–4°. In the third Se2- site, Se2- is bonded to six Bi3+ atoms to form a mixture of corner and edge-sharing SeBi6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the fourth Se2- site, Se2- is bonded to one Tl1+ and five Bi3+ atoms to form a mixture of corner and edge-sharing SeTlBi5 octahedra. The corner-sharing octahedra tilt angles range from 0–16°. In the fifth Se2- site, Se2- is bonded to five Tl1+ and one Bi3+ atom to form distorted SeTl5Bi octahedra that share corners with six SeTl5Bi octahedra and edges with twelve SeTlBi5 octahedra. The corner-sharing octahedra tilt angles range from 0–16°. In the sixth Se2- site, Se2- is bonded to six Tl1+ atoms to form SeTl6 octahedra that share corners with six SeTlBi5 octahedra and edges with twelve SeTl5Bi octahedra. The corner-sharing octahedra tilt angles range from 0–5°. In the seventh Se2- site, Se2- is bonded to six Tl1+ atoms to form SeTl6 octahedra that share corners with six SeTl5Bi octahedra and edges with twelve SeTl6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. In the eighth Se2- site, Se2- is bonded to six Tl1+ atoms to form a mixture of corner and edge-sharing SeTl6 octahedra. The corner-sharing octahedral tilt angles are 0°.

36 MATERIALS SCIENCE↗

DOE OSTI2021

Ultralow Thermal Conductivity, Multiband Electronic Structure and High Thermoelectric Figure of Merit in TlCuSe

The entanglement of lattice thermal conductivity, electrical conductivity, and Seebeck coefficient complicates the process of optimizing thermoelectric performance in most thermoelectric materials. Semiconductors with ultralow lattice thermal conductivities and high power factors at the same time are scarce but fundamentally interesting and practically important for energy conversion. In this work, an intrinsic p-type semiconductor TlCuSe that has an intrinsically ultralow thermal conductivity (0.25 W m -1 K -1 ), a high power factor (11.6 μ W cm -1 K -2 ), and a high figure of merit, ZT (1.9) at 643 K is described. The weak chemical bonds, originating from the filled antibonding orbitals p-d* within the edge-sharing CuSe 4 tetrahedra and long Tl-Se bonds in the PbClF-type structure, in conjunction with the large atomic mass of Tl lead to an ultralow sound velocity. Strong anharmonicity, coming from Tl + lone-pair electrons, boosts phonon-phonon scattering rates and further suppresses lattice thermal conductivity. The multiband character of the valence band structure contributing to power factor enhancement benefits from the lone-pair electrons of Tl + as well, which modify the orbital character of the valence bands, and pushes the valence band maximum off the Gamma-point, increasing the band degeneracy. The results provide new insight on the rational design of thermoelectric materials.

36 MATERIALS SCIENCE↗

DOE OSTI2023

Advanced Thermoluminescence Spectroscopy as a Research Tool for Semiconductor and Photonic Materials: A Review and Perspective

Thermoluminescence (TL) or thermally stimulated luminescence (TSL) spectroscopy is based on liberating charge carriers from traps in the bandgap by providing enough thermal energy to overcome the potential barrier of the traps. It provides a powerful tool to measure the positions of the localized states/traps in the bandgap. Despite that, its applications in semiconductors are very limited. Herein, the basics of TL spectroscopy and the recent advances in the technique with focus on cryogenic thermally stimulated photoemission spectroscopy (C‐TSPS) which extends TL measurements to cryogenic regime and allows the detection of very low concentrations of shallow and deep localized states is discussed. One goal herein is to introduce the reader to the use of TL and C‐TSPS in the characterization of semiconductors, explaining how it can be applied and demonstrating its advantages as a powerful tool for measuring shallow donor/acceptor ionization energies in semiconductors and as a method for characterizing compensating defects. The article also discusses interesting potential applications of C‐TSPS in new research areas such as corrosion and formation of oxide layers on metal surfaces.

36 MATERIALS SCIENCE↗

DOE OSTI2023

Building thermal dynamics modeling with deep transfer learning using a large residential smart thermostat dataset

Understanding thermal dynamics and obtaining the computational model of residential buildings enable its scaled application in energy retrofits, control optimization and decarbonization. In this paper, we present a deep learning approach to model building thermal dynamics with smart thermostat data collected from residential buildings, with the goal to investigate model generalizability. In the first stage, we developed and compared different Deep Learning architectures including Convolutional Neural Networks (CNN), Long Short-Term Memory (LSTM) models and CNN-LSTM to predict indoor air temperature in a multi-step time horizon. In the second stage, we implemented a Transfer Learning (TL) process, which aims to improve the prediction performance on a new set of buildings (targets), exploiting the knowledge of related or similar buildings (sources). Different TL strategies and source model identification methods were investigated. The study showed that the CNN-LSTM performed the best among the architectures compared, with an average Mean Absolute Error (MAE) of 0.26 °C for one-hour-ahead (twelve 5-min future steps) predictions. Furthermore, the results showed that freezing the LSTM layer and fine-tuning the other layers of the CNN-LSTM achieved the best performance among four TL strategies, which further improved the performance with respect to a machine learning approach by 10%, and proving the effectiveness and generalizability of the proposed approach. A comparison of three different source model identification methods showed that randomly selecting source models constrained by similar building characteristics can provide good TL performance while retaining simplicity comparing with other quantitative source identification methods.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

DOE OSTI2020

Radiation hardness characterization of LKH-5 scintillating glass

Radiation hardness is an important property to examine in scintillators to help determine their expected lifetime in application cases where significant radiation dose is expected. Industrial imaging systems using 9 MV linear accelerators for x-ray radiography are one such application where significant radiation doses are expected to the scintillators used. Cadmium tungstate scintillators (CWO) and Thallium doped Cesium Iodide scintillators (CsI(Tl)) are used in some high energy cargo x-ray radiography systems. However, CWO has a high manufacturing cost for adequately uniform crystals and CsI(Tl) does not have sufficient radiation hardness. LKH-5 glass is being investigated as a potential low cost replacement for CWO and CsI(Tl). In this experiment 36 samples of a terbium doped silicate glass called LKH-5 were irradiated at doses up to 5 MRad using a 9 MV linear accelerator, and the change in their transmission properties was observed. Additionally, the glass was discovered to be a radiation hard glass due to the relatively small change in the transmission of the glass: less than 3% per cm at its emission peak of 550 nm and 5 MRad. This is similar to CWO which has a reported reduction in transmitted light of 2% per cm at 5 MRad and the emission peak of 475 nm and better than CsI(Tl) which is reported to have a reduction in transmitted light of 5% per cm at the emission peak of 550 nm and 4.2 MRad dose. Furthermore, an annealing procedure is described that returned the transmission of the glass to pre-irradiation values.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

DOE OSTI2026

Transfer Learning Meets Embedded Correlated Wavefunction Theory for Chemically Accurate Molecular Simulations: Application to Calcium Carbonate Ion Pairing

Achieving chemical accuracy for molecular simulations remains a central challenge in computational chemistry. Here, we present an embedded correlated wavefunction transfer learning (ECW-TL) framework for accurately simulating molecular dynamics in the condensed phase. ECW-TL incorporates high-level electron exchange and correlation effects in ECW theory while preserving the training and computational efficiency of machine-learned interatomic potentials. We demonstrate the framework on Ca 2+ –CO 3 2– ion pairing in aqueous solution, a key process underlying CO 2 mineralization in seawater. As proof of principle, we first show that fine-tuning a DFT-revPBE-D3(BJ) baseline model with embedded-DFT-SCAN data reproduces the DFT-SCAN free-energy surface within 1 kcal/mol across all solvation states. Extending the framework to embedded MP2 and localized natural-orbital CCSD(T) further refines the free-energy profile, revealing the crucial role of exact electron exchange and correlation in determining ion-pair stability and structure. The computed ion-pair association free energy is in quantitative agreement with experimental measurements, further validating the accuracy of the ECW-TL framework. ECW-TL thus provides a general, data-efficient route for transferring CW accuracy to efficient simulations of complex aqueous and interfacial chemical processes.

cluster chemistry↗

DOE OSTI2022

Understanding the Re-entrant Phase Transition in a Non-magnetic Scheelite

We report the stereochemical activity of lone pair electrons plays a central role in determining the structural and electronic properties of both chemically simple materials such as H 2 O, as well as more complex condensed phases such as photocatalysts or thermoelectrics. TlReO 4 is a rare example of a non-magnetic material exhibiting a re-entrant phase transition and emphanitic behavior in the long-range structure. Here, we describe the role of the Tl + 6s 2 lone pair electrons in these unusual phase transitions and illustrate its tunability by chemical doping, which has broad implications for functional materials containing lone pair bearing cations. First-principles density functional calculations clearly show the contribution of the Tl + 6s 2 in the valence band region. Local structure analysis, via neutron total scattering, revealed that changes in the long-range structure of TlReO 4 occur due to changes in the correlation length of the Tl + lone pairs. This has a significant effect on the anion interactions, with long-range ordered lone pairs creating a more densely packed structure. This resulted in a trade-off between anionic repulsions and lone pair correlations that lead to symmetry lowering upon heating in the long-range structure, whereby lattice expansion was necessary for the Tl + lone pairs to become highly correlated. Similarly, introducing lattice expansion through chemical pressure allowed long-range lone pair correlations to occur over a wider temperature range, demonstrating a method for tuning the energy landscape of lone pair containing functional materials.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2025

Taylor limit studies for local helicity injection plasma startup

Solenoid-free tokamak startup techniques can simplify the design and reduce the cost of tokamak-based fusion energy systems. The newly commissioned Pegasus-III spherical tokamak provides a dedicated platform for developing a scalable solenoid-free startup approach. Local helicity injection (LHI) is one promising technique being developed on Pegasus-III, which uses compact edge current sources to drive open field line current I inj that is redistributed via helicity-conserving instabilities to initiate tokamak plasmas. These instabilities relax the system toward a minimum energy state described by Taylor relaxation theory. This relaxation process imposes a global current limit for LHI plasmas, referred to as the Taylor limit I TL ⁠, which can dictate the plasma current I p evolution. Experiments on Pegasus and Pegasus-III show that increasing this limit leads to more effective utilization of the available helicity input and higher I p plasmas. Initial Pegasus-III experiments have verified the expected I TL $\varpropto$ ( I inj B T ) 1/2 scaling holds for B T and I inj up to 0.3 T on axis and 12 kA ⁠, respectively. Additionally, data from different injector arrays show that the width of the injector aperture directly alters I TL and can be leveraged for future injector design optimization. Throughout these scaling studies, discharges were overdriven at I p = I TL by providing excess helicity input. Intermittent bursts of n = 1 magnetic activity consistent with large-scale reconnection events occurred more often as the system was increasingly overdriven leading to a flattening of the λ = μ 0 J ∥ / |B| profile, where J ∥ is the parallel current density.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

DOE OSTI2021

Structural Analysis of the US ITER ECH Transmission Line System

The electron cyclotron heating (ECH) and current drive system is one of the main plasma heating systems for ITER. It uses high-power microwave beams with the power deposition location steerable across the plasma cross section. Microwave power is conveyed via transmission lines (TLs) that run from the gyrotrons in the radio frequency building through the assembly hall and tokamak building to the ECH launchers within the tokamak vacuum vessel. The ECH system includes a vast array of interconnected TL waveguides, in-line components, and support structures.Finite element (FE) modeling provides an essential means of simulating the system, applying loads and determining deflections, rotations, forces, moments, and stresses in order to evaluate various structural and microwave transmission performance metrics. A representative FE model of the overall ECH TL system is developed in ANSYS®. This top-level model defines the centerline of the waveguide system. Waveguide segments are represented by line elements (beams and pipes) with equivalent section properties, and support structures are represented by boundary conditions. A systematic approach is used to model each ECH component with lumped masses and structurally equivalent stiffness matrices or ANSYS superelements.The top-level TL FE model is used to evaluate the various loads (thermal, vacuum, seismic, etc.) and operating scenarios. The top-level model directly calculates stresses in the straight aluminum waveguide segments. The model provides the forces and moments acting on the in-line components for detailed submodel assessments. Displacement results from the top-level analysis feed into a separate microwave performance model to help determine operational efficiency. All TL performance and thermal-structural requirements are met, as specified by the applicable codes and standards, and successfully documented in numerous technical reports and demonstrated at the final design review.

Shanmugasundaram, Aravind↗

DOE OSTI2023

Factors associated with treatment limitations in two Swedish intensive care units: Prevalence and patient involvement

Abstract The aim was to study the prevalence, documentation, and patient involvement in treatment limitations (TLs) in two Swedish intensive care units (ICUs). All patients admitted to the ICUs of two Swedish regional hospitals in 2019 were screened for inclusion. Exclusion criteria included postanesthesia care <24 h. Patients were identified using the Swedish Intensive Care Registry (SIR) and data were extracted from SIR and hospital charts. Uni‐ and multivariable logistic analysis was performed to investigate associations with the presence of TLs. A total of 3090 patients were admitted to the two ICUs in 2019. After exclusion, 1019 patients were included in the study. 45.5% were women and the mean age was 62.9 years. 26.5% of the patients had one or several TLs. Age (OR 1.04 per one year increase 95% confidence interval (CI) 1.02–1.05), SAPS3‐score (OR 1.08 per one unit increase 95% CI 1.06–1.09) and ICU length of stay (OR 1.11 per one day increase 95% CI 1.05–1.17) were independently associated with an increased likelihood of receiving a TL. 17% of the patients were involved in the decision‐making process and in >30% of cases neither the patient nor next‐of‐kin were informed. Women were to a larger extent involved in the decision process than men (24.5 vs. 12.5% p < .05). When the intensivist documented why a TL was established, patient autonomy was four times more commonly stated as the motivation for the TL among women compared to men (15.5% vs. 3.8% p < .05). TLs were common in two Swedish ICUs but a substantial number of patients and next‐of‐kin were not involved in the decision‐making process or informed of the decision. Women were more often than men engaged in the decision to establish a TL.

Jönsson, Nino↗

DOE OSTI2024

Rev1 overexpression accelerates N -methyl- N -nitrosourea (MNU)-induced thymic lymphoma by increasing mutagenesis

Rev1 has two important functions in the translesion synthesis pathway, including dCMP transferase activity, and acts as a scaffolding protein for other polymerases involved in translesion synthesis. However, the role of Rev1 in mutagenesis and tumorigenesis in vivo remains unclear. We previously generated Rev1-overexpressing (Rev1-Tg) mice and reported that they exhibited a significantly increased incidence of intestinal adenoma and thymic lymphoma (TL) after N-methyl-N-nitrosourea (MNU) treatment. In this study, we investigated mutagenesis of MNU-induced TL tumorigenesis in wild-type (WT) and Rev1-Tg mice using diverse approaches, including whole-exome sequencing (WES). In Rev1-Tg TLs, the mutation frequency was higher than that in WT TL in most cases. However, no difference in the number of nonsynonymous mutations in the Catalogue of Somatic Mutations in Cancer (COSMIC) genes was observed, and mutations involved in Notch1 and MAPK signaling were similarly detected in both TLs. Mutational signature analysis of WT and Rev1-Tg TLs revealed cosine similarity with COSMIC mutational SBS5 (aging-related) and SBS11 (alkylation-related). Interestingly, the total number of mutations, but not the genotypes of WT and Rev1-Tg, was positively correlated with the relative contribution of SBS5 in individual TLs, suggesting that genetic instability could be accelerated in Rev1-Tg TLs. Finally, we demonstrated that preleukemic cells could be detected earlier in Rev1-Tg mice than in WT mice, following MNU treatment. In conclusion, Rev1 overexpression accelerates mutagenesis and increases the incidence of MNU-induced TL by shortening the latency period, which may be associated with more frequent DNA damage-induced genetic instability.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2021

A Swollenin From Talaromyces leycettanus JCM12802 Enhances Cellulase Hydrolysis Toward Various Substrates

Swollenins exist within some fungal species and are candidate accessory proteins for the biodegradation of cellulosic substrates. Here, we describe the identification of a swollenin gene, Tlswo , in Talaromyces leycettanus JCM12802. Tlswo was successfully expressed in both Trichoderma reesei and Pichia pastoris . Assay results indicate that Tl SWO is capable of releasing reducing sugars from lichenan, barley β-glucan, carboxymethyl cellulose sodium (CMC-Na) and laminarin. The specific activity of Tl SWO toward lichenan, barley β-glucan, carboxymethyl cellulose sodium (CMC-Na) and laminarin is 9.0 ± 0.100, 8.9 ± 0.100, 2.3 ± 0.002 and 0.79 ± 0.002 U/mg, respectively. Additionally, Tl SWO had disruptive activity on Avicel and a synergistic effect with cellobiohydrolases, increasing the activity on pretreated corn stover by up to 72.2%. The functional diversity of Tl SWO broadens its applicability in experimental settings, and indicating that it may be a promising candidate for future industrial applications.

59 BASIC BIOLOGICAL SCIENCES↗

DOE OSTI2025

Data Quality Monitoring for the Hadron Calorimeters Using Transfer Learning for Anomaly Detection

The proliferation of sensors brings an immense volume of spatio-temporal (ST) data in many domains, including monitoring, diagnostics, and prognostics applications. Data curation is a time-consuming process for a large volume of data, making it challenging and expensive to deploy data analytics platforms in new environments. Transfer learning (TL) mechanisms promise to mitigate data sparsity and model complexity by utilizing pre-trained models for a new task. Despite the triumph of TL in fields like computer vision and natural language processing, efforts on complex ST models for anomaly detection (AD) applications are limited. In this study, we present the potential of TL within the context of high-dimensional ST AD with a hybrid autoencoder architecture, incorporating convolutional, graph, and recurrent neural networks. Motivated by the need for improved model accuracy and robustness, particularly in scenarios with limited training data on systems with thousands of sensors, this research investigates the transferability of models trained on different sections of the Hadron Calorimeter of the Compact Muon Solenoid experiment at CERN. The key contributions of the study include exploring TL’s potential and limitations within the context of encoder and decoder networks, revealing insights into model initialization and training configurations that enhance performance while substantially reducing trainable parameters and mitigating data contamination effects.

47 OTHER INSTRUMENTATION↗

NASA NTRS1979

On the kinetics of volatile loss from chondrites

Data by Lipschutz and coworkers (1975, 1976, 1977) on thermal release of Tl, Bi, and In from primitive chondrites are reexamined to obtain information on the nature and activation energy (E) of release processes: desorption, volume diffusion, and decomposition of the host phase. For the Allende C3 chondrite, the main release for Bi and Tl between 400 and 700 C is shown to be apparently due to desorption of a surface layer, coupled with grain boundary diffusion as the slow step. Further, the main release of In above 600 C and the small tails of Bi and Tl between 700 and 1000 C are observed to represent probably volume diffusion. Results for Abee and other primitive meteorites were found to be essentially similar, except for a very abrupt 500 C release of Tl from Krymka (81%) and Bi from Tieschitz (70%). It is suggested that this release may represent decomposition of a thermolabile phase in a late condensate, such as organic matter or phyllosilicates.

Alaerts, L.↗

NASA NTRS1983

The thermoluminescence carrier in the Dhajala chondrite

It is pointed out that the type 3 (unequilibrated) ordinary chondrites provide a major source of information on the early solar system. However, the interpretation of the data is difficult because all but a few display signs of metamorphic alteration. The present investigation is concerned with the thermoluminescence (TL) sensitivity measurements on 58 chondrules separated from the Dhajala meteorites. The data were discussed briefly by Sparks and Sears (1982). In the current investigation particular attention is given to the constraints placed by these data on the mechanism by which metamorphism is related to TL sensitivity. Dhajala-normalized TL sensitivity of the separated chondrules is plotted against chondrule mass, and a histogram of the CaO contents of 15 chondrules is presented. Histograms showing the TL sensitivity of chondrules separated from the Dhajala meteorite are also provided.

Sparks, M. H.↗