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At least 397 records · Page 22

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DOE OSTI2020

Materials Data on Re(Se2Cl3)2 by Materials Project

Re(Se2Cl3)2 crystallizes in the orthorhombic Pccn space group. The structure is three-dimensional. Re6+ is bonded in an octahedral geometry to six Cl1- atoms. There are a spread of Re–Cl bond distances ranging from 2.34–2.38 Å. There are two inequivalent Se sites. In the first Se site, Se is bonded in a distorted rectangular see-saw-like geometry to two equivalent Se and two Cl1- atoms. There are one shorter (2.34 Å) and one longer (2.36 Å) Se–Se bond lengths. There are one shorter (3.05 Å) and one longer (3.10 Å) Se–Cl bond lengths. In the second Se site, Se is bonded in a 7-coordinate geometry to two equivalent Se and five Cl1- atoms. There are a spread of Se–Cl bond distances ranging from 3.24–3.64 Å. There are three inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a distorted single-bond geometry to one Re6+ and two Se atoms. In the second Cl1- site, Cl1- is bonded in a distorted single-bond geometry to one Re6+ and two Se atoms. In the third Cl1- site, Cl1- is bonded in a single-bond geometry to one Re6+ and three equivalent Se atoms.

36 MATERIALS SCIENCE↗

DOE OSTI2019

Materials Data on Re(H3C)6 by Materials Project

Re(CH3)6 crystallizes in the monoclinic Cc space group. The structure is zero-dimensional and consists of four rhenium, hexamethyl- molecules. Re6+ is bonded in a distorted pentagonal pyramidal geometry to six C4- atoms. There are a spread of Re–C bond distances ranging from 2.13–2.15 Å. There are six inequivalent C4- sites. In the first C4- site, C4- is bonded in a distorted trigonal non-coplanar geometry to one Re6+ and three H1+ atoms. All C–H bond lengths are 1.10 Å. In the second C4- site, C4- is bonded in a distorted trigonal non-coplanar geometry to one Re6+ and three H1+ atoms. All C–H bond lengths are 1.10 Å. In the third C4- site, C4- is bonded in a distorted trigonal non-coplanar geometry to one Re6+ and three H1+ atoms. All C–H bond lengths are 1.10 Å. In the fourth C4- site, C4- is bonded in a distorted trigonal non-coplanar geometry to one Re6+ and three H1+ atoms. All C–H bond lengths are 1.10 Å. In the fifth C4- site, C4- is bonded in a distorted trigonal non-coplanar geometry to one Re6+ and three H1+ atoms. All C–H bond lengths are 1.10 Å. In the sixth C4- site, C4- is bonded in a distorted trigonal non-coplanar geometry to one Re6+ and three H1+ atoms. There is two shorter (1.10 Å) and one longer (1.11 Å) C–H bond length. There are eighteen inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one C4- atom. In the second H1+ site, H1+ is bonded in a single-bond geometry to one C4- atom. In the third H1+ site, H1+ is bonded in a single-bond geometry to one C4- atom. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one C4- atom. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one C4- atom. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one C4- atom. In the seventh H1+ site, H1+ is bonded in a single-bond geometry to one C4- atom. In the eighth H1+ site, H1+ is bonded in a single-bond geometry to one C4- atom. In the ninth H1+ site, H1+ is bonded in a single-bond geometry to one C4- atom. In the tenth H1+ site, H1+ is bonded in a single-bond geometry to one C4- atom. In the eleventh H1+ site, H1+ is bonded in a single-bond geometry to one C4- atom. In the twelfth H1+ site, H1+ is bonded in a single-bond geometry to one C4- atom. In the thirteenth H1+ site, H1+ is bonded in a single-bond geometry to one C4- atom. In the fourteenth H1+ site, H1+ is bonded in a single-bond geometry to one C4- atom. In the fifteenth H1+ site, H1+ is bonded in a single-bond geometry to one C4- atom. In the sixteenth H1+ site, H1+ is bonded in a single-bond geometry to one C4- atom. In the seventeenth H1+ site, H1+ is bonded in a single-bond geometry to one C4- atom. In the eighteenth H1+ site, H1+ is bonded in a single-bond geometry to one C4- atom.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on Re(RhO3)2 by Materials Project

Re(RhO3)2 is Hydrophilite-derived structured and crystallizes in the tetragonal P4_2/mnm space group. The structure is three-dimensional. Re6+ is bonded to six O2- atoms to form ReO6 octahedra that share corners with eight equivalent RhO6 octahedra and edges with two equivalent RhO6 octahedra. The corner-sharing octahedra tilt angles range from 48–50°. There is four shorter (1.94 Å) and two longer (1.95 Å) Re–O bond length. Rh3+ is bonded to six O2- atoms to form RhO6 octahedra that share corners with four equivalent ReO6 octahedra, corners with four equivalent RhO6 octahedra, an edgeedge with one ReO6 octahedra, and an edgeedge with one RhO6 octahedra. The corner-sharing octahedra tilt angles range from 48–55°. There are a spread of Rh–O bond distances ranging from 2.02–2.05 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to one Re6+ and two equivalent Rh3+ atoms. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to one Re6+ and two equivalent Rh3+ atoms.

36 MATERIALS SCIENCE↗

DOE OSTI2023

Multi-regime mixing modeling for local extinction and re-ignition in turbulent non-premixed flame by using LES/FDF method

Local extinction and re-ignition occur in turbulent non-premixed combustion when the Damköhler number is not large enough and the combustion is not fully mixing controlled. The occurrence of local extinction introduces locally extinguished flame holes followed by a premixed flame propagation toward the hole center to potentially reignite the flame. The co-existence of the non-premixed and premixed combustion regimes complicates the modeling since traditional combustion models are mostly for a single regime. In this work, we examine the effect of multi-regime mixing modeling in the transported filtered density function (FDF) method on the predictions of local extinction and reignition. Predictions of local extinction and reignition remain a challenge for the FDF method despite the progress made in the past. To account for the multi-regime combustion, two different mixing timescale models for non-premixed and premixed combustion are combined. A flame index based on the gradients of fuel and oxidizer is used to define a weighting factor to blend the two mixing timescale models. A turbulent jet non-premixed flame with substantial local extinction, the Sydney piloted jet flame L, is adopted as a test case to examine the performance of the multi-regime model in large-eddy simulation/FDF modeling. It is found that the traditional non-premixed mixing timescale model when combined with the modified Curl mixing leads to global extinction for the Sydney flame L without the presence of the premixed combustion regime. After accounting for the multi-regime combustion with proper detection of the different combustion regimes, the predictions for the flame statistics and the amount of local extinction are significantly improved. Furthermore, it suggests the need of including multi-regime combustion for the predictions of local extinction and re-ignition in turbulent non-premixed combustion configurations.

42 ENGINEERING↗

DOE OSTI2016

Observation of a re-entrant phase transition in the molecular complex tris(μ 2 -3,5-diisopropyl-1,2,4-triazolato-κ 2 N 1 : N 2 )trigold(I) under high pressure

We report a molecular crystal that exhibits four successive phase transitions under hydrostatic pressure, driven by aurophilic interactions, with the ground-state structure re-emerging at high pressure. The effect of pressure on two polytypes of tris(μ 2 -3,5-diisopropyl-1,2,4-triazolato-κ 2 N 1 : N 2 )trigold(I) (denoted Form-I and Form-II) has been analysed using luminescence spectroscopy, single-crystal X-ray diffraction and first-principles computation. A unique phase behaviour was observed in Form-I, with a complex sequence of phase transitions between 1 and 3.5 GPa. The ambient C 2/c mother cell transforms to a P 2 1 /n phase above 1 GPa, followed by a P 2 1 /a phase above 2 GPa and a large-volume C 2/c supercell at 2.70 GPa, with the previously observed P 2 1 /n phase then reappearing at higher pressure. The observation of crystallographically identical low- and high-pressure P 2 1 /n phases makes this a rare example of a re-entrant phase transformation. The phase behaviour has been characterized using detailed crystallographic theory and modelling, and rationalized in terms of molecular structural distortions. The dramatic changes in conformation are correlated with shifts of the luminescence maxima, from a band maximum at 14040 cm –1 at 2.40 GPa, decreasing steeply to 13550 cm –1 at 3 GPa. A similar study of Form-II displays more conventional crystallographic behaviour, indicating that the complex behaviour observed in Form-I is likely to be a direct consequence of the differences in crystal packing between the two polytypes.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2021

Challenges in Firmware Re-Hosting, Emulation, and Analysis

System emulation and firmware re-hosting have become popular techniques to answer various security and performance related questions, such as determining whether a firmware contain security vulnerabilities or meet timing requirements when run on a specific hardware platform. While this motivation for emulation and binary analysis has previously been explored and reported, starting to either work or research in the field is difficult. To this end, we provide a comprehensive guide for the practitioner or system emulation researcher. Here, we layout common challenges faced during firmware re-hosting, explaining successive steps and surveying common tools used to overcome these challenges. We provide classification techniques on five different axes, including emulator methods, system type, fidelity, emulator purpose, and control. These classifications and comparison criteria enable the practitioner to determine the appropriate tool for emulation. We use our classifications to categorize popular works in the field and present 28 common challenges faced when creating, emulating, and analyzing a system from obtaining firmwares to post emulation analysis.

97 MATHEMATICS AND COMPUTING↗

DOE OSTI2019

An Industrial Membrane System Suitable for Distributed Used Oil Re-refining

Under this SBIR project, Media and Process Technology Inc (MPT) has achieved ~60% cost reduction and system foot print of its ceramic membrane product, which leads to successful commercialization of its industrial ceramic membrane process to large scale applications. Ceramic membrane is known for its rugged materials and performance reliability; however, it has been limited in niche applications due to its cost and footprint. The low-cost ceramic membrane thus developed under this project has been field tested successfully in our semi-works production facility for used oil re-refining. Our membrane subsystem of our re-refining production capacity was tripled through the installation of this low-cost high packing density of ceramic membranes. In addition, we have successfully field tested/demonstrated with a pilot unit in two large scale applications for refinery FCC slurry upgrading and decoker/amine scrubber wastewater treatment. Commercialization of these two applications in oil refineries are currently actively pursued by our commercialization partner. With regard to the membrane product sales, we have produced >500 m 2 ceramic membranes for two full-scale installations for industrial oil/water separations in 2017, which is equivalent to ~50% of the annual US ceramic membrane market size. We will continue to push our low-cost high packing density ceramic membrane developed from this project for large scale applications, which are not currently occupied by existing ceramic membranes.

02 PETROLEUM↗

DOE OSTI2022

Study of Electrorefiner Sediment Re-Chlorination Options

A study was performed to investigate re-chlorination options for electrorefiner sediment, fulfilling a DOE Level 4 milestone within the Material Recovery and Waste Form Development campaign. The study stems from the recent identification of sediment that had accumulated in a kg-scale uranium electrorefiner at Idaho National Laboratory’s Hot Fuel Examination Facility. The study involved surveying, evaluating, and recommending options for re-chlorinating, or otherwise recovering, actinides from the sediment. Several options were investigated, including chemical and electrochemical techniques on the sediment within the electrorefiner (in situ approaches) or after its removal from the electrorefiner (ex situ approaches). A baseline approach was identified, involving electrolytic reduction of the removed sediment and subsequent electrorefining. Some options were dismissed for various deficiencies, while other options were recommended for further investigation.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

NASA NTRS2012

Re-Engineering the Mission Operations System (MOS) for the Prime and Extended Mission

One of the most challenging tasks in a space science mission is designing the Mission Operations System (MOS). Whereas the focus of the project is getting the spacecraft built and tested for launch, the mission operations engineers must build a system to carry out the science objectives. The completed MOS design is then formally assessed in the many reviews. Once a mission has completed the reviews, the Mission Operation System (MOS) design has been validated to the Functional Requirements and is ready for operations. The design was built based on heritage processes, new technology, and lessons learned from past experience. Furthermore, our operational concepts must be properly mapped to the mission design and science objectives. However, during the course of implementing the science objective in the operations phase after launch, the MOS experiences an evolutional change to adapt for actual performance characteristics. This drives the re-engineering of the MOS, because the MOS includes the flight and ground segments. Using the Spitzer mission as an example we demonstrate how the MOS design evolved for both the prime and extended mission to enhance the overall efficiency for science return. In our re-engineering process, we ensured that no requirements were violated or mission objectives compromised. In most cases, optimized performance across the MOS, including gains in science return as well as savings in the budget profile was achieved. Finally, we suggest a need to better categorize the Operations Phase (Phase E) in the NASA Life-Cycle Phases of Formulation and Implementation

Extended Mission↗

NASA NTRSDate not supplied

Development of a Low-Cost, Highly Flexible Re-Entry Platform

With a growing interest in atmospheric entry, descent, and landing research as well as the necessity to empirically test increasingly complicated entry systems, a growing need for a quick and cost-effective method of experimentation is needed. The Hypersonic Configurable Unit Ballistic Experiment is a test and evaluation platform allowing for in-situ research and rapid testing of novel technologies in a re-entry environment. HyCUBE takes the form of a small satellite-sized re-entry vehicle and, with the additional space on board the vehicle, can act as a platform for testing novel guidance and control methodologies.

Aero-Thermodynamics↗

DOE OSTI2016

RE Data Explorer: Supporting Renewable Energy Zones to Enable Low Emission Development

This fact sheet overviews the benefits of using the RE Data Explorer tool to analyze and develop renewable energy zones. Renewable energy zones are developed through a transmission planning and approval process customized for renewable energy. RE Data Explorer analysis can feed into broader stakeholder discussions and allow stakeholders to easily visualize potential zones. Stakeholders can access pertinent data to inform transmission planning and enable investment.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2014

Optimization of an individual re-identification modeling process using biometric features

We present results from the optimization of a re-identification process using two sets of biometric data obtained from the Civilian American and European Surface Anthropometry Resource Project (CAESAR) database. The datasets contain real measurements of features for 2378 individuals in a standing (43 features) and seated (16 features) position. A genetic algorithm (GA) was used to search a large combinatorial space where different features are available between the probe (seated) and gallery (standing) datasets. Results show that optimized model predictions obtained using less than half of the 43 gallery features and data from roughly 16% of the individuals available produce better re-identification rates than two other approaches that use all the information available.

CAESAR↗

DOE OSTI2017

Optimization of Poly(DL-Lactic Acid) Degradation and Evaluation of Biological Re-polymerization

Poly(DL-lactic acid) or PLA is a biodegradable polymer. It has received much attention since it plays an important role in resolving the global warming problem. The protease produced by Actinomadura keratinilytica strain T16-1 was previously reported as having PLA depolymerase potential and being applicable to PLA biodegradation, which was used in this work. Therefore, this research demonstrates the important basic knowledge on the biological degradation process by the crude PLA-degrading enzyme from strain T16-1. Its re-polymerization was evaluated. The optimization of PLA degradation by statistical methods based on central composite design was determined. Approximately 6700 mg/l PLA powder was degraded by the crude enzyme under optimized conditions: an initial enzyme activity of 200 U/ml, incubated at 60 °C for 24 h released 6843 mg/l lactic acid with 82% conversion, which was similar to the commercial enzyme proteinase K (81%). The degradable products were re-polymerized repeatedly by using commercial lipase as a catalyst under a nitrogen atmosphere for 6 h. A PLA oligomer was achieved with a molecular weight of 378 Da (n = 5). This is the first report to demonstrate the high efficiency of the enzyme to degrade 100% of PLA powder and to show the biological recycling process of PLA, which is promising for the treatment and utilization of biodegradable plastic wastes in the future.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2018

Effect of Rare Earth Ionic Radii on Structural, Electric, Magnetic and Thermoelectric Properties of REMnO{sub 3} (RE = Dy, Gd, Eu and Sm) Manganites

In this communication, we present a systematic investigation on structural, electric, magnetic and thermoelectric power properties of REMnO{sub 3} (RE = Dy, Gd, Eu and Sm) manganites which were prepared using solid-state reaction route. The samples exhibit orthorhombic crystal structure with Pbnm space group. Rietveld analysis of x-ray diffraction (XRD) data shows that the unit cell volume increases with increase in ionic radii of the rare earth ion, r{sub RE}. The particle size was calculated from the scanning electron microscope (SEM) images. The estimated particle size is observed to decrease with increasing ionic radii of the rare earth ions. All samples exhibit insulating behaviour and display immeasurably high resistivity at low temperatures. Magnetization studies indicate that the samples display a transition in the low temperature region. Magnetization data also reveals that antiferromagnetic behaviour is observed for all samples. Thermoelectric power results show that large thermoelectric power is seen for these manganites. Thermoelectric power of high-temperature region was successfully analysed using small polaron hopping (SPH) model.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

DOE OSTI2019

One-step synthesis of tetrahedral rhenium chalcocyanide cluster complexes [{Re_4(µ_3-Q)_4}(CN){sub 12}]{sup 4−} (Q = S, Se, Te) using ReI{sub 3}

A new method is proposed for the one-step synthesis of tetrahedral rhenium chalcocyanide cluster complexes [{Re_4(µ_3-Q)_4}(CN){sub 12}]{sup 4−} (Q = S, Se, Te) using rhenium(III) iodide as the starting compound. A cluster complex of the composition K4[{Re_4S_4}(CN){sub 12}]•H{sub 2}O was synthesized for the first time and characterized by X-ray diffraction.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2014

Dimer monomer transition and dimer re-formation play important role for ATM cellular function during DNA repair

Highlights: • ATM phosphorylates the opposite strand of the dimer in response to DNA damage. • The PETPVFRLT box of ATM plays a key role in its dimer dissociation in DNA repair. • The dephosphorylation of ATM is critical for dimer re-formation after DNA repair. - Abstract: The ATM protein kinase, is a serine/threonine protein kinase that is recruited and activated by DNA double-strand breaks, mediates responses to ionizing radiation in mammalian cells. Here we show that ATM is held inactive in unirradiated cells as a dimer and phosphorylates the opposite strand of the dimer in response to DNA damage. Cellular irradiation induces rapid intermolecular autophosphorylation of serine 1981 that causes dimer dissociation and initiates cellular ATM kinase activity. ATM cannot phosphorylate the substrates when it could not undergo dimer monomer transition. After DNA repair, the active monomer will undergo dephosphorylation to form dimer again and dephosphorylation is critical for dimer re-formation. Our work reveals novel function of ATM dimer monomer transition and explains why ATM dimer monomer transition plays such important role for ATM cellular activity during DNA repair.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2016

Re-entrant relaxor ferroelectricity of methylammonium lead iodide

In this paper, we have performed a piezoresponse force microscopy (PFM) study on methylammonium lead iodide (MAPbI 3 ) thin films in normal (non-resonance, non-band-excitation) contact mode. In contrast to the ferroelectric Pb 0.76 Ca 0.24 TiO 3 (PCT) control sample, a typical ferroelectric response was not observed. However, a nonlinear electric field dependence of the local PFM amplitude was found in MAPbI 3 , similar to PCT. An analysis combining results on structure, dielectric dispersion, and weak ferroelectricity demonstrates that MAPbI 3 is actually a re-entrant relaxor ferroelectric which, upon cooling, enters into a relaxor phase below its ferroelectric phase transition at ~327 K, due to the balance between the long range ferroelectric order and structural methylammonium group orientational disorder. The ferroelectricity at room temperature is compromised due to the re-entrant relaxor behavior, causing the poor polarization retention or weak ferroelectricity. Finally, our findings essentially conciliate the conflicting experimental results on MAPbI 3 's ferroelectricity and are beneficial both for basic understanding as well as for device applications.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

DOE OSTI2019

Re-splitting δ f method for electro-magnetic gyrokinetic particle-in-cell (PIC) simulation of tokamak plasmas

A new method based on a re-splitting δ f technique is proposed to mitigate the cancellation problem in electro-magnetic gyrokinetic PIC simulation. This new scheme, together with the pull-back mitigation (PBM) scheme (Mishchenko et al., 2014), have recently been implemented in the GEM code (Chen et al., 2003). These two algorithms are systematically compared with the original GEM algorithm for the simulation of the ion temperature gradient (ITG) mode, the kinetic ballooning mode (KBM), the toroidal Alfvén eigenmode (TAE) and the energetic particle mode (EPM). The three algorithms agree well for all of these modes. Moreover, both the re-splitting method and PBM can mitigate the cancellation problem and improve the computational efficiency.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗