Proceedings of the High Energy Density Matter (HEDM) Conference Held in New Orleans, Louisiana on 12-15 March 1989

DTIC Science & Technology

1989-07-01

distance in a planar arrangement of ArH3 , with the argon directly above the apical hydrogen. Matcha and 3, Milleur’ confined their calculations for...Phys. .11, 27 (1976). 7. W. J. Stevens, H-. Basch, and M. Krauss, J. Chem. Phys. il 6026 (1984). 8. R. L. Matcha , and Mac B. Milleur, J. Chem. Phys. f2

Propulsion Systems

DTIC Science & Technology

2011-03-31

Manual 91 - 710 Vol. 2 ( AFSPCMAN 91 - 710 V2). 8. Astrium EADS. 2010. cs.astrium.eads.net. April. 9. Astrium EADS. 2010. : http...of the High Energy Density Matter (HEDM) Conference. Albuquerque, NM, February 24-27, (Phillips Lab PL-CP- 91 -3003, p. 3 ). 104. Sullivan, D. J...Chapter 3 . DATES COVERED (From - To) 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Chapter 18 - Propulsion Systems 5b. GRANT NUMBER 5c. PROGRAM ELEMENT

Correlation between Temperature-dependent Fatigue Resistance and Differential Scanning Calorimetry Analysis for 2 Contemporary Rotary Instruments.

PubMed

Arias, Ana; Macorra, José C; Govindjee, Sanjay; Peters, Ove A

2018-04-01

The aim of this study was to assess differences in cyclic fatigue (CF) life of contemporary heat-treated nickel-titanium rotary instruments at room and body temperatures and to document corresponding phase transformations. Forty Hyflex EDM (H-EDM) files (Coltene, Cuyahoga Falls, OH [#25/.08, manufactured by electrical discharge machining]) and 40 TRUShape (TS) files (Dentsply Tulsa Dental Specialties, Tulsa, OK [#25/.06v, manufactured by grinding and shape setting]) were divided into 2 groups (n = 20) for CF resistance tests in a water bath either at room (22°C ± 0.5°C) or body temperature (37°C ± 0.5°C). Instruments were rotated in a simulated canal (angle = 60°, radius = 3 mm, and center of the curvature 5 mm from the tip) until fracture occurred. The motor was controlled by an electric circuit that was interrupted after instrument fracture. The mean half-life and beta and eta Weibull parameters were determined and compared. Two instruments of each brand were subjected to differential scanning calorimetry (DSC). While TS instruments lasted significantly longer at room temperature (mean life = 234.7 seconds; 95% confidence interval [CI], 209-263.6) than at body temperature (mean life = 83.2 seconds; 95% CI, 76-91.1), temperature did not affect H-EDM behavior (room temperature mean life = 725.4 seconds; 95% CI, 658.8-798.8 and body temperature mean life = 717.9 seconds; 95% CI, 636.8-809.3). H-EDM instruments significantly outlasted TS instruments at both temperatures. At body temperature, TS was predominantly austenitic, whereas H-EDM was martensitic or in R-phase. TS was in a mixed austenitic/martensitic phase at 22°C, whereas H-EDM was in the same state as at 37°C. H-EDM had a longer fatigue life than TS, which showed a marked decrease in fatigue life at body temperature; neither the life span nor the state of the microstructure in the DSC differed for H-EDM between room or body temperature. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Carbon-oxygen clusters as hypothetical high energy-density materials

NASA Astrophysics Data System (ADS)

Evangelisti, Stefano

1997-05-01

An an initio investigation on the hypothetical systems C nO n ( n = 2, 3, 4) is presented. Calculations have been performed at SCF and MP2 level, using a [3s2p1 d] basis set on each atom. At this level of approximation, two metastable structures have been found. They are C 2O 2 with C 2v symmetry (an irregular tetrahedron) and C 4O 4 with T d symmetry (two regular tetrahedra copenetrating each other). On the other hand, the search of local minima with C nv structures has failed for n = 3, 4. For the two metastable structures also larger basis sets have been used, up to [4s3p2d1f] (in the case of C 4O 4, at SCF level only). The computed energy release of the dissociation reaction (C nO n → n CO) of the two metastable structures is very high (about 100 kcal per mole of CO produced). It is of the same magnitude of the energy computed for the corresponding isoelectronic structures N 4 and N 8. If these or similar CO-clusters could be synthesized, these systems are candidates to be high energy-density materials (HEDM).

Mesoscale Science with High Energy X-ray Diffraction Microscopy at the Advanced Photon Source

NASA Astrophysics Data System (ADS)

Suter, Robert

2014-03-01

Spatially resolved diffraction of monochromatic high energy (> 50 keV) x-rays is used to map microstructural quantities inside of bulk polycrystalline materials. The non-destructive nature of High Energy Diffraction Microscopy (HEDM) measurements allows tracking of responses as samples undergo thermo-mechanical or other treatments. Volumes of the order of a cubic millimeter are probed with micron scale spatial resolution. Data sets allow direct comparisons to computational models of responses that frequently involve long-ranged, multi-grain interactions; such direct comparisons have only become possible with the development of HEDM and other high energy x-ray methods. Near-field measurements map the crystallographic orientation field within and between grains using a computational reconstruction method that simulates the experimental geometry and matches orientations in micron sized volume elements to experimental data containing projected grain images in large numbers of Bragg peaks. Far-field measurements yield elastic strain tensors through indexing schemes that sort observed diffraction peaks into sets associated with individual crystals and detect small radial motions in large numbers of such peaks. Combined measurements, facilitated by a new end station hutch at Advanced Photon Source beamline 1-ID, are mutually beneficial and result in accelerated data reduction. Further, absorption tomography yields density contrast that locates secondary phases, void clusters, and cracks, and tracks sample shape during deformation. A collaboration led by the Air Force Research Laboratory and including the Advanced Photon Source, Lawrence Livermore National Laboratory, Carnegie Mellon University, Petra-III, and Cornell University and CHESS is developing software and hardware for combined measurements. Examples of these capabilities include tracking of grain boundary migrations during thermal annealing, tensile deformation of zirconium, and combined measurements of nickel superalloys and a titanium alloy under tensile forces. Work supported by NSF grant DMR-1105173

Proceedings of the High Energy Density Matter (HEDM) Contractor’s Conference Held in Woods Hole, Massachusetts on 6-8 June 1993

DTIC Science & Technology

1993-11-01

SRI International 75 "The Dodecahedral N20 Molecule: Some Theoretical Predictions" Henry F. Schaefer II1, University of Georgia 94 "Theoretical...and P20 Molecules: Some Theoretical Predictions," Henry Schaefer, University of Georgia 2 -2:30 c Investigations of the Structure and Dynamics of...Department of Chemistry APD Cryogenics, Inc. University of California, Berkeley 1833 Vultee Street Berkeley, CA 94708 Allentown, PA 18103 8 Henry F

Development of Predictive Models of Advanced Propulsion Concepts for Low Cost Space Transportation

NASA Technical Reports Server (NTRS)

Morrell, Michael Randy

2002-01-01

This final report presents the Graduate Student Research Program (GSRP) work Mr. Morrell was able to complete as a summer intern at NASA MSFS during the summer of 2001, and represents work completed from inception through project termination. The topics include: 1) NASA TD40 Organization; 2) Combustion Physics Lab; 3) Advanced Hydrocarbon Fuels; 4) GSRP Summer Tasks; 5) High Pressure Facility Installation; 6) High Pressure Combustion Issues; 7) High Energy Density Matter (HEDM) Hydrocarbons; and 8) GSRP Summer Intern Summary.

Proceedings of the High Energy Density Matter (HEDM) Contractors’ Conference Held 1-3 June 1997 in Chantilly, VA.

DTIC Science & Technology

1998-03-01

David R. Yarkony, Johns Hopkins University 3:00 - 3:30 Break 3:30 - 4:00 Calorimetric Measurements of O Atom Recombination Dr. Peter Taborek and...University Stillwater, OK 74078 405-744-5174 405-744-6007 dlt@osuunx.ucc.okstate.edu Dr. David R. Yarkony Dept. of Chemistry Johns Hopkins...Chemistry Johns Hopkins University 3400 N. Charles St., Remsen Baltimore, MD 21218 410-516-4669 410-516-8420 yangxin@jhunix.hcf.jhu.edu Prof. David

Combined Near and Far Field High Energy Diffraction Microscopy Dataset for Ti-7Al Tensile Specimen Elastically Loaded In Situ

DOE Data Explorer

Turner, Todd J.; Shade, Paul A; Bernier, Joel V.; Li, Shiu Fai; Schuren, Jay C.; Lind, Jonathan F.; Lienert, Ulrich; Kenesei, Peter; Suter, Robert; Blank, Basil; Almer, Jonathan

2016-01-01

We present both near-field HEDM data that maps out the grain morphology and intragranular crystallographic orientations and far-field HEDM data that provides the grain centroid, grain average crystallographic orientation, and grain average elastic strain tensor for each grain. Finally, we provide a finite element mesh that can be utilized to simulate deformation in the volume of this Ti-7Al specimen.

Investigation of fatigue crack initiation from a non-metallic inclusion via high energy x-ray diffraction microscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Naragani, Diwakar; Sangid, Michael D.; Shade, Paul A.

Crack initiation at inclusions is a dominant, unavoidable and life-limiting failure mechanism of important structural materials. Fatigue progresses in a complex manner to find the ‘weakest link’ in the microstructure, leading to crack nucleation. In this study, fully 3-D characterization methods using high-energy synchrotron x-rays are combined with in-situ mechanical testing to study the crack initiation mechanism in a Ni-based superalloy specimen. The specimen was produced via powder metallurgy and seeded with a non-metallic inclusion. Two x-ray techniques were employed: absorption contrast computed micro-tomography (μ-CT) to determine the morphology of the inclusion and its location in the gauge section ofmore » the specimen; and far-field high-energy diffraction microscopy (FF-HEDM) to resolve the centroids, average orientations, and lattice strains of the individual grains comprising the microstructure surrounding the inclusion. Sequential μ-CT and FF-HEDM scans were carried out at both peak and zero applied stress following schedules of cyclic deformation. The µ-CT data showed the onset and location of crack initiation, and the FF-HEDM data provided temporal and spatial evolution of the intergranular strains. Strain partitioning and the associated stress heterogeneities that develop are shown to stabilize within a few loading cycles. Elasto-viscoplastic fast Fourier transform simulations were utilized to supplement interpretation of the experimental stress distributions and compared with the experimental stress distributions. In conclusion, appropriate conditions for crack nucleation in the form of stress gradients were demonstrated and created by virtue of the inclusion, specifically the residual stress state and local bonding state at the inclusion-matrix interface.« less

Investigation of fatigue crack initiation from a non-metallic inclusion via high energy x-ray diffraction microscopy

DOE PAGES

Naragani, Diwakar; Sangid, Michael D.; Shade, Paul A.; ...

2017-07-14

Crack initiation at inclusions is a dominant, unavoidable and life-limiting failure mechanism of important structural materials. Fatigue progresses in a complex manner to find the ‘weakest link’ in the microstructure, leading to crack nucleation. In this study, fully 3-D characterization methods using high-energy synchrotron x-rays are combined with in-situ mechanical testing to study the crack initiation mechanism in a Ni-based superalloy specimen. The specimen was produced via powder metallurgy and seeded with a non-metallic inclusion. Two x-ray techniques were employed: absorption contrast computed micro-tomography (μ-CT) to determine the morphology of the inclusion and its location in the gauge section ofmore » the specimen; and far-field high-energy diffraction microscopy (FF-HEDM) to resolve the centroids, average orientations, and lattice strains of the individual grains comprising the microstructure surrounding the inclusion. Sequential μ-CT and FF-HEDM scans were carried out at both peak and zero applied stress following schedules of cyclic deformation. The µ-CT data showed the onset and location of crack initiation, and the FF-HEDM data provided temporal and spatial evolution of the intergranular strains. Strain partitioning and the associated stress heterogeneities that develop are shown to stabilize within a few loading cycles. Elasto-viscoplastic fast Fourier transform simulations were utilized to supplement interpretation of the experimental stress distributions and compared with the experimental stress distributions. In conclusion, appropriate conditions for crack nucleation in the form of stress gradients were demonstrated and created by virtue of the inclusion, specifically the residual stress state and local bonding state at the inclusion-matrix interface.« less

Comparison between diffraction contrast tomography and high-energy diffraction microscopy on a slightly deformed aluminium alloy.

PubMed

Renversade, Loïc; Quey, Romain; Ludwig, Wolfgang; Menasche, David; Maddali, Siddharth; Suter, Robert M; Borbély, András

2016-01-01

The grain structure of an Al-0.3 wt%Mn alloy deformed to 1% strain was reconstructed using diffraction contrast tomography (DCT) and high-energy diffraction microscopy (HEDM). 14 equally spaced HEDM layers were acquired and their exact location within the DCT volume was determined using a generic algorithm minimizing a function of the local disorientations between the two data sets. The microstructures were then compared in terms of the mean crystal orientations and shapes of the grains. The comparison shows that DCT can detect subgrain boundaries with disorientations as low as 1° and that HEDM and DCT grain boundaries are on average 4 µm apart from each other. The results are important for studies targeting the determination of grain volume. For the case of a polycrystal with an average grain size of about 100 µm, a relative deviation of about ≤10% was found between the two techniques.

Proceedings of the High Energy Density Matter (HEDM) Conference Held in Rosslyn, Virginia on 12-13 May 1987,

DTIC Science & Technology

1987-09-01

Laboratory), Maj Larry Davis (AF Office of Scientific Research) 1730 Social hour May 13, 1987 0800 "Measurement of Charge Transfer Between D3+ and SiH 4 A...species such as 02 (alAg), NF 132 (a A) and Mg*( P), with long radiative lifetimes, may also be useful as temporary energy storage media . 4) Strained...full potential energy search on the limiting 12 el. C2Li2 and 10 el. B2B -2 species we focus on the prevalence of the highly energetic rhombic

Advanced Hydrocarbon Fuel Development

NASA Technical Reports Server (NTRS)

Bai, S. Don; Rodgers, Stephen L. (Technical Monitor)

2000-01-01

As a part of a high energy density materials (HEDM) development, the hot fire tests for Quadricyclane, 1,7 Octadiyne, AFRL-1, Biclopropylidene, and CINCH (Dimethyl amino ethyl azide) have been conducted at NASA/MSFC. The first 4 materials for this task are provided from Air Force Research Laboratory at Edward Air Force Base and US Army provided CINCH. The performance of these fuels is compared with RP-1. The preliminary results of these tests are presented. The preliminary results of Quadricyclane tests indicate that the specific impulse and c-star efficiency for quadricyclane at the mixture ratio 1.94 are approximately 5 sec and 105 ft/sec better than the RP-1 at mixture ratio 1.9. The 1,7 Octadiyne test indicate that the specific impulse and c-star efficiency at the mixture ratio 2.1 are approximately -1 sec and 89 ft/sec differ than the RP-1 at mixture ratio 2.04. The Quadricyclane soot buildup at the combustor is a little more than RP-1, but detail study of soot formation is not considered at this time. There was no visual soot buildup for the 1,7 Octadiyne and AFRL-1.

Connecting heterogeneous single slip to diffraction peak evolution in high-energy monochromatic X-ray experiments

PubMed Central

Pagan, Darren C.; Miller, Matthew P.

2014-01-01

A forward modeling diffraction framework is introduced and employed to identify slip system activity in high-energy diffraction microscopy (HEDM) experiments. In the framework, diffraction simulations are conducted on virtual mosaic crystals with orientation gradients consistent with Nye’s model of heterogeneous single slip. Simulated diffraction peaks are then compared against experimental measurements to identify slip system activity. Simulation results compared against diffraction data measured in situ from a silicon single-crystal specimen plastically deformed under single-slip conditions indicate that slip system activity can be identified during HEDM experiments. PMID:24904242

High-energy synchrotron x-ray techniques for studying irradiated materials

DOE PAGES

Park, Jun-Sang; Zhang, Xuan; Sharma, Hemant; ...

2015-03-20

High performance materials that can withstand radiation, heat, multiaxial stresses, and corrosive environment are necessary for the deployment of advanced nuclear energy systems. Nondestructive in situ experimental techniques utilizing high energy x-rays from synchrotron sources can be an attractive set of tools for engineers and scientists to investigate the structure–processing–property relationship systematically at smaller length scales and help build better material models. In this paper, two unique and interconnected experimental techniques, namely, simultaneous small-angle/wide-angle x-ray scattering (SAXS/WAXS) and far-field high-energy diffraction microscopy (FF-HEDM) are presented. Finally, the changes in material state as Fe-based alloys are heated to high temperatures ormore » subject to irradiation are examined using these techniques.« less

Direct measurement of critical resolved shear stress of prismatic and basal slip in polycrystalline Ti using high energy X-ray diffraction microscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, L.; Zheng, Z.; Phukan, H.

Knowledge of the critical resolved shear stress (CRSS) values of different slip modes is important for accurately modeling plastic deformation of hexagonal materials. Here, we demonstrate that CRSS can be directly measured with an in-situ high energy X-ray diffraction microscopy (HEDM) experiment. A commercially pure Ti tensile specimen was deformed up to 2.6% strain. In-situ far-field HEDM experiments were carried out to track the evolution of crystallographic orientations, centers of masses, and stress states of 1153 grains in a material volume of 1.1mm×1mm×1mm. Predominant prismatic slip was identified in 18 grains, where the orientation change occurred primarily by rotation aroundmore » the c-axis during specimen deformation. By analyzing the resolved shear stress on individual slip systems, the estimated CRSS for prismatic slip is 96±18 MPa. Predominant basal slip was identified in 22 other grains, where the 2 orientation change occurred primarily by tilting the c-axis about an axis in the basal plane. The estimated CRSS for basal slip is 127±33 MPa. The ratio of CRSS basal/CRSS prismatic is in the range of 1.7-2.1. From indirect assessment, the CRSS for pyramidal < c+a > slip is likely greater than 240MPa. Lastly, grain size and free surface effects on the CRSS value in different grains are also examined.« less

Direct measurement of critical resolved shear stress of prismatic and basal slip in polycrystalline Ti using high energy X-ray diffraction microscopy

DOE PAGES

Wang, L.; Zheng, Z.; Phukan, H.; ...

2017-05-07

Knowledge of the critical resolved shear stress (CRSS) values of different slip modes is important for accurately modeling plastic deformation of hexagonal materials. Here, we demonstrate that CRSS can be directly measured with an in-situ high energy X-ray diffraction microscopy (HEDM) experiment. A commercially pure Ti tensile specimen was deformed up to 2.6% strain. In-situ far-field HEDM experiments were carried out to track the evolution of crystallographic orientations, centers of masses, and stress states of 1153 grains in a material volume of 1.1mm×1mm×1mm. Predominant prismatic slip was identified in 18 grains, where the orientation change occurred primarily by rotation aroundmore » the c-axis during specimen deformation. By analyzing the resolved shear stress on individual slip systems, the estimated CRSS for prismatic slip is 96±18 MPa. Predominant basal slip was identified in 22 other grains, where the 2 orientation change occurred primarily by tilting the c-axis about an axis in the basal plane. The estimated CRSS for basal slip is 127±33 MPa. The ratio of CRSS basal/CRSS prismatic is in the range of 1.7-2.1. From indirect assessment, the CRSS for pyramidal < c+a > slip is likely greater than 240MPa. Lastly, grain size and free surface effects on the CRSS value in different grains are also examined.« less

Theoretical Studies of Possible Synthetic Routes for the High Energy Density Material Td N4: Excited Electronic States

NASA Technical Reports Server (NTRS)

Lee, Timothy J.; Dateo, Christopher E.

2001-01-01

Vertical electronic excitation energies for single states have been computed for the high energy density material (HEDM) Td N4 in order to assess possible synthetic routes that originate from excited electronic states of N2 molecules. Several ab initio theoretical approaches have been used, including complete active space self-consistent field (CASSCF), state averaged CASSCF (SA-CASSCF), singles configuration interaction (CIS), CIS with second-order and third-order correlation corrections [CIS(D)) and CIS(3)], and linear response singles and doubles coupled-cluster (LRCCSD), which is the highest level of theory employed. Standard double zeta polarized (DZP) and triple zeta double polarized (TZ2P) one-particle basis sets were used. The CASSCF calculations are found to overestimate the excitation energies, while the SA-CASSCF approach rectifies this error to some extent, but not completely. The accuracy of the CIS calculations varied depending on the particular state, while the CIS(D), CIS(3), and LRCCSD results are in generally good agreement. Based on the LRCCSD calculations, the lowest six excited singlet states are 9.35(l(sup)T1), 10.01(l(sup)T2), 10.04(1(sup)A2), 10.07(1(sup)E), 10.12(2(sup)T1), and 10.42(2(sup)T2) eV above the ground state, respectively. Comparison of these excited state energies with the energies of possible excited states of N2+N2 fragments, leads us to propose that the most likely synthetic route for Td N4 involving this mechanism arises from combination of two bound quintet states of N2.

Non-Destructive Characterization of UO2+x Nuclear Fuels

DOE PAGES

Pokharel, Reeju; Brown, Donald W.; Clausen, Bjørn; ...

2017-10-27

This article describes the effect of fabrication conditions on as-sintered microstructures of various stoichiometric ratios of uranium dioxide, UO 2+x, with the aim of enhancing the understanding of fabrication process and developing and validating a predictive microstructurebased model for fuel performance. We demonstrate the ability of novel, non-destructive methods such as near-field high-energy X-ray diffraction microscopy (nf-HEDM) and micro-computed tomography (μ-CT) to probe bulk samples of high-Z materials by non-destructively characterizing three samples: UO 2.00, UO 2.11, and UO 2.16, which were sintered at 1450°C for 4 hours. The measured 3D microstructures revealed that grain size and porosity were influencedmore » by deviation from stoichiometry.« less

XCALIBUR: a Vertical Takeoff TSTO RLV Concept with a HEDM Upperstage and a Scram-Rocket Booster

NASA Astrophysics Data System (ADS)

Bradford, J.

2002-01-01

A new 3rd generation, two-stage-to-orbit (TSTO) reusable launch vehicle (RLV) has been designed. The Xcalibur concept represents a novel approach due to its integration method for the upperstage element of the system. The vertical-takeoff booster, which is powered by rocket-based combined-cycle (RBCC) engines, carries the upperstage internally in the aft section of the airframe to a Mach 15 staging condition. The upperstage is released from the booster and carries the 6,820 kg of payload to low earth orbit (LEO) using its high energy density matter (HEDM) propulsion system. The booster element is capable of returning to the original launch site in a ramjet-cruise propulsion mode. Both the booster and the upperstage utilize advanced technologies including: graphite-epoxy tanks, metal-matrix composites, UHTC TPS materials, electro- mechanical actuators (EMAs), and lightweight subsystems (avionics, power distribution, etc.). The booster system is enabled main propulsion system which utilizes four RBCC engines. These engines operate in four distinct modes: air- augmented rocket (AAR), ramjet, scram-rocket, and all-rocket. The booster operates in AAR mode from takeoff to Mach 3, with ramjet mode operation from Mach 3 to Mach 6. The rocket re-ignition for scram-rocket mode occurs at Mach 6, with all-rocket mode from Mach 14 to the staging condition. The extended utilization of the scram-rocket mode greatly improves vehicle performance by providing superior vehicle acceleration when compared to the scramjet mode performance over the same flight region. Results indicate that the specific impulse penalty due to the scram-rocket mode operation is outweighed by the reduced flight time, smaller vehicle size due to increased mixture ratio, and lower allowable maximum dynamic pressure. A complete vehicle system life-cycle analysis was performed in an automated, multi-disciplinary design environment. Automated disciplinary performance analysis tools include: trajectory (POST), propulsion (SCCREAM), aeroheating (TCAT II), and an Excel spreadsheet for component weight estimation. These tools were automated using `file wrappers' in Phoenix Integration's ModelCenter collaborative design environment. Performance tools utilized for the analysis, but not requiring automation included IDEAS for solid modeling and APAS for the aerodynamic analysis. The paper describes the vehicle concept and operation, discussing the types of technologies used and the nominal flight scenario. A brief discussion explaining the decision-making process for the vehicle configuration is included. For cost predictions, NAFCOM-derived cost estimating relationships were used. Economic predictions were developed using a number of codes, including CABAM (financials), AATe (operations), and GTSafetyII (safety and reliability).

Theoretical Studies of Some HEDM Species: Cyclic O4, Cyclic O3 and Cubane

NASA Technical Reports Server (NTRS)

Walch, Stephen P.; Langhoff, Steve R. (Technical Monitor)

1996-01-01

Calculations have been carried out for the HEDM species (cyclic O4, cyclic O3, and cubane) using CASSCF/derivative and CASSCF/ICCI methods. Cyclic O4 is of interest both as a potential HEDM species and because of its possible role in the ozone deficit problem in atmospheric chemistry. We have studied the pathway for decomposition from the D(2d) minimum and also have found the approximate location of the singlet triplet crossing. The barrier to decomposition is found to be about 9 kcal/mol and is not limited by the singlet triplet crossing. For cyclic O3 we have focused on the crossings between the lowest five surfaces (X(1)A(1), s(1)A(1), (1)A(2), (1)B(1), and (1)B(2)) to provide some insight into ways to form cyclic O3 photochemically. The crossing region between the X(1)A(1) and 2(1)A(1) surfaces is in agreement with the work of Xantheas et al. The calculations show that vertical excitation from the ground state to the (1)A(2) state leads to a crossing with the (1)A(1) manifold near the crossing region of the X(1)A(1) and 2(1)A(1) surfaces. We have studied the decomposition pathways for cubane to benzene plus acetylene and to cyclooctatetraene. We have also studied the ground and excited states for the photochemical ring closure step. The state which closes to cubane can be described as a double triplet pi to pi* excitation with respect to the ground state. Thus, this state has only a small oscillator strength with respect to the ground state. However, there is a singlet pi to pi* state at nearly the same energy and excitation to this state followed by intersystem crossing could lead to the triplet pi to pi* state.

Three new energetic complexes with N,N-bis(1H-tetrazole-5-yl)-amine as high energy density materials: syntheses, structures, characterization and effects on the thermal decomposition of RDX.

PubMed

Yang, Qi; Song, Xiaxia; Zhang, Wendou; Hou, Lei; Gong, Qibing; Xie, Gang; Wei, Qing; Chen, Sanping; Gao, Shengli

2017-02-21

Three new energetic complexes, [Pb(bta)(H 2 O)] n (1), [PbCu(bta) 2 (H 2 O) 5 ]·2H 2 O (2) and PbCu(bta) 2 (3) (H 2 bta = N,N-bis(1H-tetrazole-5-yl)-amine), have been synthesized and characterised. In particular, 3 was readily synthesized by dehydration of 2 at 190 °C. Single crystal X-ray diffraction revealed that 1 has a 3D framework structure and 2 presents a 3D supermolecular architecture. Thermoanalyses demonstrated that the main frames of 1 and 2 have good thermostabilities up to 314 °C for 1 and 231 °C for 2. Non-isothermal kinetic and thermodynamic parameters of exothermic decomposition processes of 1 and 2 were obtained by Kissinger's and Ozawa's methods. Based on the constant-volume combustion energies measured by a precise rotating-bomb calorimeter, the standard molar enthalpies of formation of 1 and 2 were determined. The calculation of the detonation properties of 1 and 2 and the impact sensitivity tests of 1, 2 and 3 were carried out. In addition, 1, 2 and 3 were explored as combustion promoters to accelerate the thermal decompositions of RDX (1,3,5-trinitro-1,3,5-triazine) by differential scanning calorimetry. Experimental results showed that 1, 2 and 3 can be used as HEDMs in the field of combustion promoters and insensitive 2 can be regarded as a safer form for mass storage and transportation than sensitive 3.

Analyzing shear band formation with high resolution X-ray diffraction

DOE PAGES

Pagan, Darren C.; Obstalecki, Mark; Park, Jun-Sang; ...

2018-01-10

Localization of crystallographic slip into shear bands during uniaxial compression of a copper single crystal is studied using very far-field high-energy diffraction microscopy (vff-HEDM). Diffracted intensity was collected in-situ as the crystal deformed using a unique mobile detector stage that provided access to multiple diffraction peaks with high-angular resolution. From the diffraction data, single crystal orientation pole figures (SCPFs) were generated and are used to track the evolution of the distribution of lattice orientation that develops as slip localizes. To aid the identification of ‘signatures’ of shear band formation and analyze the SCPF data, a model of slip-driven lattice reorientationmore » within shear bands is introduced. Confidence is built in conclusions drawn from the SCPF data about the character of internal slip localization through comparisons with strain fields on the sample surface measured simultaneously using digital image correlation. From the diffraction data, we find that the active slip direction and slip plane are not directly aligned with the orientation of the shear bands that formed. In fact, by extracting the underlying slip system activity from the SCPF data, we show that intersecting shear bands measured on the surface of the sample arise from slip primarily on the same underlying single slip system. These new vff-HEDM results raise significant questions on the use of surface measurements for slip system activity estimation.« less

Analyzing shear band formation with high resolution X-ray diffraction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pagan, Darren C.; Obstalecki, Mark; Park, Jun-Sang

Localization of crystallographic slip into shear bands during uniaxial compression of a copper single crystal is studied using very far-field high-energy diffraction microscopy (vff-HEDM). Diffracted intensity was collected in-situ as the crystal deformed using a unique mobile detector stage that provided access to multiple diffraction peaks with high-angular resolution. From the diffraction data, single crystal orientation pole figures (SCPFs) were generated and are used to track the evolution of the distribution of lattice orientation that develops as slip localizes. To aid the identification of 'signatures' of shear band formation and analyze the SCPF data, a model of slip-driven lattice reorientationmore » within shear bands is introduced. Confidence is built in conclusions drawn from the SCPF data about the character of internal slip localization through comparisons with strain fields on the sample surface measured simultaneously using digital image correlation. From the diffraction data, we find that the active slip direction and slip plane are not directly aligned with the orientation of the shear bands that formed. In fact, by extracting the underlying slip system activity from the SCPF data, we show that intersecting shear bands measured on the surface of the sample arise from slip primarily on the same underlying single slip system. These new vff-HEDM results raise significant questions on the use of surface measurements for slip system activity estimation. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.« less

In situ, 3D characterization of the deformation mechanics of a superelastic NiTi shape memory alloy single crystal under multiscale constraint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paranjape, Harshad M.; Paul, Partha P.; Amin-Ahmadi, Behnam

Microstructural elements in NiTi shape memory alloys (SMAs) – precipitates, phase boundaries, inclusions, grain boundaries – can be viewed as sources of multiscale constraint that influence their deformation response. In this paper, we characterized in situ, and in 3D, the deformation and the evolution of microstructure during a tension test in a superelastic NiTi specimen containing some of these sources of constraint. The method used was far-field high-energy X-ray diffraction microscopy (ff-HEDM), complemented by electron microscopy. We simulated the local stress state in the specimen using a microstructural model informed by the experimental data. Using these combined microstructure, deformation, andmore » stress data, we report three phenomena, and relate them to specific sources of constraint. During initial elastic loading, axial lattice strain in austenite increased monotonically. On partial stress-induced phase transformation to martensite, the stress redistributed to both phases leading to a stress relaxation in austenite. The specimen contained a dense distribution of inclusions, which led to the activation of martensite habit plane variants that produce less than theoretical maximum transformation strain. Large Ni 4Ti 3 precipitates potentially contributed to the poor transformation response. Under load, proportional gradients in local rotation and elastic stretch developed in the martensite phase, because of the constraint at phase interfaces. Finally, this combined ff-HEDM, electron microscopy, microstructural simulation toolbox provides a versatile method to understand the effect of constraint on inelastic deformation in other alloys with hierarchical microstructure.« less

In situ, 3D characterization of the deformation mechanics of a superelastic NiTi shape memory alloy single crystal under multiscale constraint

DOE PAGES

Paranjape, Harshad M.; Paul, Partha P.; Amin-Ahmadi, Behnam; ...

2017-11-20

Microstructural elements in NiTi shape memory alloys (SMAs) – precipitates, phase boundaries, inclusions, grain boundaries – can be viewed as sources of multiscale constraint that influence their deformation response. In this paper, we characterized in situ, and in 3D, the deformation and the evolution of microstructure during a tension test in a superelastic NiTi specimen containing some of these sources of constraint. The method used was far-field high-energy X-ray diffraction microscopy (ff-HEDM), complemented by electron microscopy. We simulated the local stress state in the specimen using a microstructural model informed by the experimental data. Using these combined microstructure, deformation, andmore » stress data, we report three phenomena, and relate them to specific sources of constraint. During initial elastic loading, axial lattice strain in austenite increased monotonically. On partial stress-induced phase transformation to martensite, the stress redistributed to both phases leading to a stress relaxation in austenite. The specimen contained a dense distribution of inclusions, which led to the activation of martensite habit plane variants that produce less than theoretical maximum transformation strain. Large Ni 4Ti 3 precipitates potentially contributed to the poor transformation response. Under load, proportional gradients in local rotation and elastic stretch developed in the martensite phase, because of the constraint at phase interfaces. Finally, this combined ff-HEDM, electron microscopy, microstructural simulation toolbox provides a versatile method to understand the effect of constraint on inelastic deformation in other alloys with hierarchical microstructure.« less

Validation of micro-mechanical FFT-based simulations using High Energy Diffraction Microscopy on Ti-7Al

DOE PAGES

Tari, Vahid; Lebensohn, Ricardo A.; Pokharel, Reeju; ...

2018-08-01

Here, a validation is reported for micromechanical simulation using a reimplementation of an elasto-viscoplastic FFT-based (EVPFFT) formulation, i.e., the Micromechanical Analysis of Stress-strain Inhomogeneities with fast Fourier transform (MASSIF) code, against experimental data obtained from synchrotron x-ray diffraction. The experimental data was collected during in-situ deformation of a titanium alloy specimen by High Energy Diffraction Microscopy (HEDM), which provided the average elastic strain tensor and orientation of each grain in a polycrystalline sample. MASSIF was used to calculate the local micromechanical fields in a Ti-7Al polycrystalline sample at different load levels. The initially attempted simulation showed that, although the effectivemore » response was calibrated to reproduce the experiment, MASSIF was not able to reproduce the micromechanical fields at the scale of individual grains. The differences between calculated and measured averages at the grain scale were related to initial residual strains resulting from the prior processing of the material, which had not been incorporated in the original calculation. Accordingly, a new simulation was instantiated using information on the measured residual strains to define a set of eigenstrains, calculated via an Eshelby approximation. This initialization significantly improved the correlation between calculated and simulated fields for all strain and stress components, for measurements performed within the elastic regime. For the measurements at the highest load, which was past plastic yield, the correlations deteriorated because of plastic deformation at the grain level and the lack of an accurate enough constitutive description in this deformation regime.« less

Validation of micro-mechanical FFT-based simulations using High Energy Diffraction Microscopy on Ti-7Al

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tari, Vahid; Lebensohn, Ricardo A.; Pokharel, Reeju

Here, a validation is reported for micromechanical simulation using a reimplementation of an elasto-viscoplastic FFT-based (EVPFFT) formulation, i.e., the Micromechanical Analysis of Stress-strain Inhomogeneities with fast Fourier transform (MASSIF) code, against experimental data obtained from synchrotron x-ray diffraction. The experimental data was collected during in-situ deformation of a titanium alloy specimen by High Energy Diffraction Microscopy (HEDM), which provided the average elastic strain tensor and orientation of each grain in a polycrystalline sample. MASSIF was used to calculate the local micromechanical fields in a Ti-7Al polycrystalline sample at different load levels. The initially attempted simulation showed that, although the effectivemore » response was calibrated to reproduce the experiment, MASSIF was not able to reproduce the micromechanical fields at the scale of individual grains. The differences between calculated and measured averages at the grain scale were related to initial residual strains resulting from the prior processing of the material, which had not been incorporated in the original calculation. Accordingly, a new simulation was instantiated using information on the measured residual strains to define a set of eigenstrains, calculated via an Eshelby approximation. This initialization significantly improved the correlation between calculated and simulated fields for all strain and stress components, for measurements performed within the elastic regime. For the measurements at the highest load, which was past plastic yield, the correlations deteriorated because of plastic deformation at the grain level and the lack of an accurate enough constitutive description in this deformation regime.« less

Minimizing Experimental Setup Time and Effort at APS beamline 1-ID through Instrumentation Design

DOE Office of Scientific and Technical Information (OSTI.GOV)

Benda, Erika; Almer, Jonathan; Kenesei, Peter

2016-01-01

Sector 1-ID at the APS accommodates a number of dif-ferent experimental techniques in the same spatial enve-lope of the E-hutch end station. These include high-energy small and wide angle X-ray scattering (SAXS and WAXS), high-energy diffraction microscopy (HEDM, both near and far field modes) and high-energy X-ray tomography. These techniques are frequently combined to allow the users to obtain multimodal data, often attaining 1 μm spatial resolution and <0.05º angular resolution. Furthermore, these techniques are utilized while the sam-ple is thermo-mechanically loaded to mimic real operat-ing conditions. The instrumentation required for each of these techniques and environments has been designedmore » and configured in a modular way with a focus on stability and repeatability between changeovers. This approach allows the end station to be more versatile, capable of collecting multi-modal data in-situ while reducing time and effort typically required for set up and alignment, resulting in more efficient beam time use. Key instrumentation de-sign features and layout of the end station are presented.« less

Permeability analysis of Asbuton material used as core layers of water resistance in the body of dam

NASA Astrophysics Data System (ADS)

Rahim, H.; Tjaronge, M. W.; Thaha, A.; Djamaluddin, R.

2017-11-01

In order to increase consumption of the local materials and national products, large reserves of Asbuton material about 662.960 million tons in the Buton Islands became an alternative as a waterproof core layer in the body of dam. The Asbuton material was used in this research is Lawele Granular Asphalt (LGA). This study was an experimental study conducted in the laboratory by conducting density testing (content weight) and permeability on Asbuton material. Testing of the Asbuton material used Falling Head method to find out the permeability value of Asbuton material. The data of test result to be analyzed are the relation between compaction energy and density value also relation between density value and permeability value of Asbuton material. The result shows that increases the number of blow apply to the Asbuton material at each layer will increase the density of the Asbuton material. The density value of Asbuton material that satisfies the requirements for use as an impermeable core layer in the dam body is 1.53 grams/cm3. The increase the density value (the weight of the contents) of the Asbuton material will reduce its permeability value of the Asbuton material.

A review of low density porous materials used in laser plasma experiments

NASA Astrophysics Data System (ADS)

Nagai, Keiji; Musgrave, Christopher S. A.; Nazarov, Wigen

2018-03-01

This review describes and categorizes the synthesis and properties of low density porous materials, which are commonly referred to as foams and are utilized for laser plasma experiments. By focusing a high-power laser on a small target composed of these materials, high energy and density states can be produced. In the past decade or so, various new target fabrication techniques have been developed by many laboratories that use high energy lasers and consequently, many publications and reviews followed these developments. However, the emphasis so far has been on targets that did not utilize low density porous materials. This review therefore, attempts to redress this balance and endeavors to review low density materials used in laser plasma experiments in recent years. The emphasis of this review will be on aspects of low density materials that are of relevance to high energy laser plasma experiments. Aspects of low density materials such as densities, elemental compositions, macroscopic structures, nanostructures, and characterization of these materials will be covered. Also, there will be a brief mention of how these aspects affect the results in laser plasma experiments and the constrictions that these requirements put on the fabrication of low density materials relevant to this field. This review is written from the chemists' point of view to aid physicists and the new comers to this field.

46 CFR 164.009-7 - Contents of application.

Code of Federal Regulations, 2010 CFR

2010-10-01

... trade name of the material. (b) The thickness or density, or both, of the material, or the range of thicknesses or densities, or both, of the material as manufactured. (c) The composition of the material. (d) The density and percentage of moisture and volatile matter of each component of the material. (e) The...

46 CFR 164.009-7 - Contents of application.

Code of Federal Regulations, 2011 CFR

2011-10-01

... trade name of the material. (b) The thickness or density, or both, of the material, or the range of thicknesses or densities, or both, of the material as manufactured. (c) The composition of the material. (d) The density and percentage of moisture and volatile matter of each component of the material. (e) The...

46 CFR 164.009-7 - Contents of application.

Code of Federal Regulations, 2014 CFR

2014-10-01

... trade name of the material. (b) The thickness or density, or both, of the material, or the range of thicknesses or densities, or both, of the material as manufactured. (c) The composition of the material. (d) The density and percentage of moisture and volatile matter of each component of the material. (e) The...

46 CFR 164.009-7 - Contents of application.

Code of Federal Regulations, 2013 CFR

2013-10-01

... trade name of the material. (b) The thickness or density, or both, of the material, or the range of thicknesses or densities, or both, of the material as manufactured. (c) The composition of the material. (d) The density and percentage of moisture and volatile matter of each component of the material. (e) The...

Mass of materials: the impact of designers on construction ergonomics.

PubMed

Smallwood, John

2012-01-01

Many construction injuries are musculoskeletal related in the form of sprains and strains arising from the handling of materials, which are specified by designers. The paper presents the results of a study conducted among delegates attending two 'designing for H&S' (DfH&S) seminars using a questionnaire. The salient findings include: the level of knowledge relative to the mass and density of materials is limited; designers generally do not consider the mass and density of materials when designing structures and elements and specifying materials; to a degree designers appreciate that the mass and density of materials impact on construction ergonomics; designers rate their knowledge of the mass and density of materials as limited, and designers appreciate the potential of the consideration of the mass and density of materials to contribute to an improvement in construction ergonomics. Conclusions include: designers lack the requisite knowledge relative to the mass and density of materials; designers are thus precluded from conducting optimum design hazard identification and risk assessments, and tertiary built environment designer education does not enlighten designers relative to construction ergonomics. Recommendations include: tertiary built environment designer education should construction ergonomics; professional associations should raise the level of awareness relative to construction ergonomics, and design practices should include a category 'mass and density of materials' in their practice libraries.

Density of Spray-Formed Materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kevin M. McHugh; Volker Uhlenwinkel; Nils Ellendr

2008-06-01

Spray Forming is an advanced materials processing technology that transforms molten metal into a near-net-shape solid by depositing atomized droplets onto a substrate. Depending on the application, the spray-formed material may be used in the as-deposited condition or it may undergo post-deposition processing. Regardless, the density of the as-deposited material is an important issue. Porosity is detrimental because it can significantly reduce strength, toughness, hardness and other properties. While it is not feasible to achieve fully-dense material in the as-deposited state, density greater than 99% of theoretical density is possible if the atomization and impact conditions are optimized. Thermal conditionsmore » at the deposit surface and droplet impact angle are key processing parameters that influence the density of the material. This paper examines the factors that contribute to porosity formation during spray forming and illustrates that very high as-deposited density is achieved by optimizing processing parameters.« less

Embankment Criteria and Performance Report: Adobe Dam Gila River Basin, New River and Phoenix City Streams, Arizona.

DTIC Science & Technology

1983-06-01

Field Control Results 18 - Record Test Results 18 GRAVEL DRAIN MATERIAL, 19 FILTER MATERIAL, 20 ABUTMET INFILL MATERIAL- 20 X. EMBANKMENT ANALYSIS 21 XI...Thirty-three in-situ density tests were conducted in the near surface embankment foundation materials by the sand displacement method . An additional...seven densities were obtained from undisturbed samples by the bulk density method . The results of density tests in the foundation are shown on plate

Density measurements as a condition monitoring approach for following the aging of nuclear power plant cable materials

NASA Astrophysics Data System (ADS)

Gillen, K. T.; Celina, M.; Clough, R. L.

1999-10-01

Monitoring changes in material density has been suggested as a potentially useful condition monitoring (CM) method for following the aging of cable jacket and insulation materials in nuclear power plants. In this study, we compare density measurements and ultimate tensile elongation results versus aging time for most of the important generic types of commercial nuclear power plant cable materials. Aging conditions, which include thermal-only, as well as combined radiation plus thermal, were chosen such that potentially anomalous effects caused by diffusion-limited oxidation (DLO) are unimportant. The results show that easily measurable density increases occur in most important cable materials. For some materials and environments, the density change occurs at a fairly constant rate throughout the mechanical property lifetime. For cases involving so-called induction-time behavior, density increases are slow to moderate until after the induction time, at which point they begin to increase dramatically. In other instances, density increases rapidly at first, then slows down. The results offer strong evidence that density measurements, which reflect property changes under both radiation and thermal conditions, could represent a very useful CM approach.

Minnealloy: a new magnetic material with high saturation flux density and low magnetic anisotropy

NASA Astrophysics Data System (ADS)

Mehedi, Md; Jiang, Yanfeng; Suri, Pranav Kumar; Flannigan, David J.; Wang, Jian-Ping

2017-09-01

We are reporting a new soft magnetic material with high saturation magnetic flux density, and low magnetic anisotropy. The new material is a compound of iron, nitrogen and carbon, α‧-Fe8(NC), which has saturation flux density of 2.8  ±  0.15 T and magnetic anisotropy of 46 kJ m-3. The saturation flux density is 27% higher than pure iron, a widely used soft magnetic material. Soft magnetic materials are very important building blocks of motors, generators, inductors, transformers, sensors and write heads of hard disk. The new material will help in the miniaturization and efficiency increment of the next generation of electronic devices.

Low-dislocation-density epitatial layers grown by defect filtering by self-assembled layers of spheres

DOEpatents

Wang, George T.; Li, Qiming

2013-04-23

A method for growing low-dislocation-density material atop a layer of the material with an initially higher dislocation density using a monolayer of spheroidal particles to bend and redirect or directly block vertically propagating threading dislocations, thereby enabling growth and coalescence to form a very-low-dislocation-density surface of the material, and the structures made by this method.

Density controlled carbon nanotube array electrodes

DOEpatents

Ren, Zhifeng F [Newton, MA; Tu, Yi [Belmont, MA

2008-12-16

CNT materials comprising aligned carbon nanotubes (CNTs) with pre-determined site densities, catalyst substrate materials for obtaining them and methods for forming aligned CNTs with controllable densities on such catalyst substrate materials are described. The fabrication of films comprising site-density controlled vertically aligned CNT arrays of the invention with variable field emission characteristics, whereby the field emission properties of the films are controlled by independently varying the length of CNTs in the aligned array within the film or by independently varying inter-tubule spacing of the CNTs within the array (site density) are disclosed. The fabrication of microelectrode arrays (MEAs) formed utilizing the carbon nanotube material of the invention is also described.

A promising high-energy-density material.

PubMed

Zhang, Wenquan; Zhang, Jiaheng; Deng, Mucong; Qi, Xiujuan; Nie, Fude; Zhang, Qinghua

2017-08-03

High-energy density materials represent a significant class of advanced materials and have been the focus of energetic materials community. The main challenge in this field is to design and synthesize energetic compounds with a highest possible density and a maximum possible chemical stability. Here we show an energetic compound, [2,2'-bi(1,3,4-oxadiazole)]-5,5'-dinitramide, is synthesized through a two-step reaction from commercially available reagents. It exhibits a surprisingly high density (1.99 g cm -3 at 298 K), poor solubility in water and most organic solvents, decent thermal stability, a positive heat of formation and excellent detonation properties. The solid-state structural features of the synthesized compound are also investigated via X-ray diffraction and several theoretical techniques. The energetic and sensitivity properties of the explosive compound are similar to those of 2, 4, 6, 8, 10, 12-(hexanitrohexaaza)cyclododecane (CL-20), and the developed compound shows a great promise for potential applications as a high-energy density material.High energy density materials are of interest, but density is the limiting factor for many organic compounds. Here the authors show the formation of a high density energetic compound from a two-step reaction between commercially available compounds that exhibit good heat thermal stability and detonation properties.

Structural materials and components

NASA Technical Reports Server (NTRS)

Gagliani, John (Inventor); Lee, Raymond (Inventor)

1982-01-01

High density structural (blocking) materials composed of a polyimide filled with glass microballoons and methods for making such materials. Structural components such as panels which have integral edgings and/or other parts made of the high density materials.

Adaptive noise correction of dual-energy computed tomography images.

PubMed

Maia, Rafael Simon; Jacob, Christian; Hara, Amy K; Silva, Alvin C; Pavlicek, William; Mitchell, J Ross

2016-04-01

Noise reduction in material density images is a necessary preprocessing step for the correct interpretation of dual-energy computed tomography (DECT) images. In this paper we describe a new method based on a local adaptive processing to reduce noise in DECT images An adaptive neighborhood Wiener (ANW) filter was implemented and customized to use local characteristics of material density images. The ANW filter employs a three-level wavelet approach, combined with the application of an anisotropic diffusion filter. Material density images and virtual monochromatic images are noise corrected with two resulting noise maps. The algorithm was applied and quantitatively evaluated in a set of 36 images. From that set of images, three are shown here, and nine more are shown in the online supplementary material. Processed images had higher signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) than the raw material density images. The average improvements in SNR and CNR for the material density images were 56.5 and 54.75%, respectively. We developed a new DECT noise reduction algorithm. We demonstrate throughout a series of quantitative analyses that the algorithm improves the quality of material density images and virtual monochromatic images.

Method of synthesizing a low density material

DOEpatents

Lorensen, L.E.; Monaco, S.B.

1987-02-27

A novel method of synthesizing a polymeric material of low density of the order of 50mg/cc or less. Such a low density material has applications in many areas including laser target fabrication. The method comprises preparing a polymer blend of two incompatible polymers as a major and a minor phase by mixing them and extruding the mixture, and then selectively extracting the major component, to yield a fine, low density structure.

Bulk densities of materials from selected pine-site hardwoods

Treesearch

Clyde Vidrine; George E. Woodson

1982-01-01

Bulk densities of hardwood materials from low and high density species were determined for green and air-dry conditions. Materials consisted of whole-tree chips, bark-free chips, bark as collected from three types of debarkers (ring, rosser head, and drum debarkers) sawdust, planer shavings, flakes, logging residues, baled branchwood, steel-strapped firewood, and...

46 CFR 164.007-9 - Procedure for approval.

Code of Federal Regulations, 2010 CFR

2010-10-01

... each component. (4) A sample of the material at least 1 foot square in the thickness and density proposed by the manufacturer to be tested. When more than one thickness of a material of the same density... and densities in which it is proposed to manufacture or use the material together with any information...

An Electrochemical Capacitor with Applicable Energy Density of 7.4 Wh/kg at Average Power Density of 3000 W/kg.

PubMed

Zhai, Teng; Lu, Xihong; Wang, Hanyu; Wang, Gongming; Mathis, Tyler; Liu, Tianyu; Li, Cheng; Tong, Yexiang; Li, Yat

2015-05-13

Electrochemical capacitors represent a new class of charge storage devices that can simultaneously achieve high energy density and high power density. Previous reports have been primarily focused on the development of high performance capacitor electrodes. Although these electrodes have achieved excellent specific capacitance based on per unit mass of active materials, the gravimetric energy densities calculated based on the weight of entire capacitor device were fairly small. This is mainly due to the large mass ratio between current collector and active material. We aimed to address this issue by a 2-fold approach of minimizing the mass of current collector and increasing the electrode performance. Here we report an electrochemical capacitor using 3D graphene hollow structure as current collector, vanadium sulfide and manganese oxide as anode and cathode materials, respectively. 3D graphene hollow structure provides a lightweight and highly conductive scaffold for deposition of pseudocapacitive materials. The device achieves an excellent active material ratio of 24%. Significantly, it delivers a remarkable energy density of 7.4 Wh/kg (based on the weight of entire device) at the average power density of 3000 W/kg. This is the highest gravimetric energy density reported for asymmetric electrochemical capacitors at such a high power density.

Breast density evaluation using spectral mammography, radiologist reader assessment and segmentation techniques: a retrospective study based on left and right breast comparison

PubMed Central

Molloi, Sabee; Ding, Huanjun; Feig, Stephen

2015-01-01

Purpose The purpose of this study was to compare the precision of mammographic breast density measurement using radiologist reader assessment, histogram threshold segmentation, fuzzy C-mean segmentation and spectral material decomposition. Materials and Methods Spectral mammography images from a total of 92 consecutive asymptomatic women (50–69 years old) who presented for annual screening mammography were retrospectively analyzed for this study. Breast density was estimated using 10 radiologist reader assessment, standard histogram thresholding, fuzzy C-mean algorithm and spectral material decomposition. The breast density correlation between left and right breasts was used to assess the precision of these techniques to measure breast composition relative to dual-energy material decomposition. Results In comparison to the other techniques, the results of breast density measurements using dual-energy material decomposition showed the highest correlation. The relative standard error of estimate for breast density measurements from left and right breasts using radiologist reader assessment, standard histogram thresholding, fuzzy C-mean algorithm and dual-energy material decomposition was calculated to be 1.95, 2.87, 2.07 and 1.00, respectively. Conclusion The results indicate that the precision of dual-energy material decomposition was approximately factor of two higher than the other techniques with regard to better correlation of breast density measurements from right and left breasts. PMID:26031229

46 CFR 164.009-17 - Density measurement.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 6 2010-10-01 2010-10-01 false Density measurement. 164.009-17 Section 164.009-17...: SPECIFICATIONS AND APPROVAL MATERIALS Noncombustible Materials for Merchant Vessels § 164.009-17 Density measurement. (a) The measurements described in this section are made to determine the density of a sample. (b...

Correction of localized shape errors on optical surfaces by altering the localized density of surface or near-surface layers

DOEpatents

Taylor, John S.; Folta, James A.; Montcalm, Claude

2005-01-18

Figure errors are corrected on optical or other precision surfaces by changing the local density of material in a zone at or near the surface. Optical surface height is correlated with the localized density of the material within the same region. A change in the height of the optical surface can then be caused by a change in the localized density of the material at or near the surface.

Method of altering the effective bulk density of solid material and the resulting product

DOEpatents

Kool, Lawrence B.; Nolen, Robert L.; Solomon, David E.

1983-01-01

A method of adjustably tailoring the effective bulk density of a solid material in which a mixture comprising the solid material, a film-forming polymer and a volatile solvent are sprayed into a drying chamber such that the solvent evaporates and the polymer dries into hollow shells having the solid material captured within the shell walls. Shell density may be varied as a function of solid/polymer concentration, droplet size and drying temperature.

Quantitative electron density characterization of soft tissue substitute plastic materials using grating-based x-ray phase-contrast imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sarapata, A.; Chabior, M.; Zanette, I.

2014-10-15

Many scientific research areas rely on accurate electron density characterization of various materials. For instance in X-ray optics and radiation therapy, there is a need for a fast and reliable technique to quantitatively characterize samples for electron density. We present how a precise measurement of electron density can be performed using an X-ray phase-contrast grating interferometer in a radiographic mode of a homogenous sample in a controlled geometry. A batch of various plastic materials was characterized quantitatively and compared with calculated results. We found that the measured electron densities closely match theoretical values. The technique yields comparable results between amore » monochromatic and a polychromatic X-ray source. Measured electron densities can be further used to design dedicated X-ray phase contrast phantoms and the additional information on small angle scattering should be taken into account in order to exclude unsuitable materials.« less

Purification of metal-organic framework materials

DOEpatents

Farha, Omar K.; Hupp, Joseph T.

2012-12-04

A method of purification of a solid mixture of a metal-organic framework (MOF) material and an unwanted second material by disposing the solid mixture in a liquid separation medium having a density that lies between those of the wanted MOF material and the unwanted material, whereby the solid mixture separates by density differences into a fraction of wanted MOF material and another fraction of unwanted material.

Purification of metal-organic framework materials

DOEpatents

Farha, Omar K.; Hupp, Joseph T.

2015-06-30

A method of purification of a solid mixture of a metal-organic framework (MOF) material and an unwanted second material by disposing the solid mixture in a liquid separation medium having a density that lies between those of the wanted MOF material and the unwanted material, whereby the solid mixture separates by density differences into a fraction of wanted MOF material and another fraction of unwanted material.

Influences of granular constraints and surface effects on the heterogeneity of elastic, superelastic, and plastic responses of polycrystalline shape memory alloys

DOE PAGES

Paranjape, Harshad M.; Paul, Partha P.; Sharma, Hemant; ...

2017-02-16

Deformation heterogeneities at the microstructural length-scale developed in polycrystalline shape memory alloys (SMAs) during superelastic loading are studied using both experiments and simulations. In situ X-ray diffraction, specifically the far-field high energy diffraction microscopy (ff-HEDM) technique, was used to non-destructively measure the grain-averaged statistics of position, crystal orientation, elastic strain tensor, and volume for hundreds of austenite grains in a superelastically loaded nickel-titanium (NiTi) SMA. These experimental data were also used to create a synthetic microstructure within a finite element model. The development of intragranular stresses were then simulated during tensile loading of the model using anisotropic elasticity. Driving forcesmore » for phase transformation and slip were calculated from these stresses. The grain-average responses of individual austenite crystals examined before and after multiple stress-induced transformation events showed that grains in the specimen interior carry more axial stress than the surface grains as the superelastic response "shakes down". Examination of the heterogeneity within individual grains showed that regions near grain boundaries exhibit larger stress variation compared to the grain interiors. As a result, this intragranular heterogeneity is more strongly driven by the constraints of neighboring grains than the initial stress state and orientation of the individual grains.« less

Influences of granular constraints and surface effects on the heterogeneity of elastic, superelastic, and plastic responses of polycrystalline shape memory alloys

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paranjape, Harshad M.; Paul, Partha P.; Sharma, Hemant

Deformation heterogeneities at the microstructural length-scale developed in polycrystalline shape memory alloys (SMAs) during superelastic loading are studied using both experiments and simulations. In situ X-ray diffraction, specifically the far-field high energy diffraction microscopy (ff-HEDM) technique, was used to non-destructively measure the grain-averaged statistics of position, crystal orientation, elastic strain tensor, and volume for hundreds of austenite grains in a superelastically loaded nickel-titanium (NiTi) SMA. These experimental data were also used to create a synthetic microstructure within a finite element model. The development of intragranular stresses were then simulated during tensile loading of the model using anisotropic elasticity. Driving forcesmore » for phase transformation and slip were calculated from these stresses. The grain-average responses of individual austenite crystals examined before and after multiple stress-induced transformation events showed that grains in the specimen interior carry more axial stress than the surface grains as the superelastic response "shakes down". Examination of the heterogeneity within individual grains showed that regions near grain boundaries exhibit larger stress variation compared to the grain interiors. As a result, this intragranular heterogeneity is more strongly driven by the constraints of neighboring grains than the initial stress state and orientation of the individual grains.« less

The role of adequate reference materials in density measurements in hemodialysis

NASA Astrophysics Data System (ADS)

Furtado, A.; Moutinho, J.; Moura, S.; Oliveira, F.; Filipe, E.

2015-02-01

In hemodialysis, oscillation-type density meters are used to measure the density of the acid component of the dialysate solutions used in the treatment of kidney patients. An incorrect density determination of this solution used in hemodialysis treatments can cause several and adverse events to patients. Therefore, despite the Fresenius Medical Care (FME) tight control of the density meters calibration results, this study shows the benefits of mimic the matrix usually measured to produce suitable reference materials for the density meter calibrations.

High-Capacity Cathode Material with High Voltage for Li-Ion Batteries

DOE PAGES

Shi, Ji -Lei; Xiao, Dong -Dong; Ge, Mingyuan; ...

2018-01-15

Electrochemical energy storage devices with a high energy density are an important technology in modern society, especially for electric vehicles. The most effective approach to improve the energy density of batteries is to search for high-capacity electrode materials. According to the concept of energy quality, a high-voltage battery delivers a highly useful energy, thus providing a new insight to improve energy density. Based on this concept, a novel and successful strategy to increase the energy density and energy quality by increasing the discharge voltage of cathode materials and preserving high capacity is proposed. The proposal is realized in high-capacity Li-richmore » cathode materials. The average discharge voltage is increased from 3.5 to 3.8 V by increasing the nickel content and applying a simple after-treatment, and the specific energy is improved from 912 to 1033 Wh kg-1. The current work provides an insightful universal principle for developing, designing, and screening electrode materials for high energy density and energy quality.« less

Measuring the Density of Different Materials by Using the Fast Neutron Beam and Associated Alpha Particle Technique

NASA Astrophysics Data System (ADS)

Sudac, D.; Nad, K.; Orlic, Z.; Obhodas, J.; Valkovic, V.

2016-06-01

It was demonstrated in the previous work that various threat materials could be detected inside the sea going cargo container by measuring the three variables, carbon and oxygen concentration and density of investigated material. Density was determined by measuring transmitted neutrons, which is not always practical in terms of setting up the instrument geometry. In order to enable more geometry flexibility, we have investigated the possibility of using the scattered neutrons in cargo material identification. For that purpose, the densities of different materials were measured depending on the position of neutron detectors and neutron generator with respect to the target position. One neutron detector was put above the target, one behind and one in front of the target, above the neutron generator. It was shown that all three positions of neutron detectors can be successfully used to measure the target density, but only if the detected neutrons are successfully discriminated from the gamma rays.

High-Capacity Cathode Material with High Voltage for Li-Ion Batteries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shi, Ji -Lei; Xiao, Dong -Dong; Ge, Mingyuan

Electrochemical energy storage devices with a high energy density are an important technology in modern society, especially for electric vehicles. The most effective approach to improve the energy density of batteries is to search for high-capacity electrode materials. According to the concept of energy quality, a high-voltage battery delivers a highly useful energy, thus providing a new insight to improve energy density. Based on this concept, a novel and successful strategy to increase the energy density and energy quality by increasing the discharge voltage of cathode materials and preserving high capacity is proposed. The proposal is realized in high-capacity Li-richmore » cathode materials. The average discharge voltage is increased from 3.5 to 3.8 V by increasing the nickel content and applying a simple after-treatment, and the specific energy is improved from 912 to 1033 Wh kg-1. The current work provides an insightful universal principle for developing, designing, and screening electrode materials for high energy density and energy quality.« less

Evaluation of Minimum Asphalt Concrete Thickness Criteria

DTIC Science & Technology

2008-10-01

9 Figure 6. Dry density versus moisture content for CH material... density measurements. ............................ 24 Figure 18. EPC installation in a crushed gravel base course layer...Construction Materials Materials Characterization Laboratory Testing Field Testing Test Section Construction Hydrometer, Modified Proctor , Specific

Pack Density Limitations of Hybrid Parachutes

NASA Technical Reports Server (NTRS)

Zwicker, Matthew L.; Sinclair, Robert J.

2013-01-01

The development and testing of the Orion crew capsule parachute system has provided a unique opportunity to study dense parachute packing techniques and limits, in order to establish a new baseline for future programs. The density of parachute packs has a significant influence on vibration loads, retention system stresses, and parachute mortar performance. Material compositions and pack densities of existing designs for space capsule recovery were compared, using the pack density of the Apollo main parachutes as the current baseline. The composition of parachutes has changed since Apollo, incorporating new materials such as Kevlar , Vectran , Teflon and Spectra . These materials have different specific densities than Nylon, so the densities of hybrid parachute packs cannot be directly compared to Nylon parachutes for determination of feasibility or volume allocation. Six parachute packs were evaluated in terms of weighted average solid density in order to achieve a non-dimensional comparison of packing density. Means of mitigating damage due to packing pressure and mortar firing were examined in light of the Capsule Parachute Assembly System (CPAS) and Apollo experience. Parachute design improvements including incorporation of modern materials and manufacturing processes serves to make CPAS the new knowledge base on which future spacecraft parachute systems will be built.

MO-FG-204-06: A New Algorithm for Gold Nano-Particle Concentration Identification in Dual Energy CT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, L; Shen, C; Ng, M

Purpose: Gold nano-particle (GNP) has recently attracted a lot of attentions due to its potential as an imaging contrast agent and radiotherapy sensitiser. Imaging the GNP at its low contraction is a challenging problem. We propose a new algorithm to improve the identification of GNP based on dual energy CT (DECT). Methods: We consider three base materials: water, bone, and gold. Determining three density images from two images in DECT is an under-determined problem. We propose to solve this problem by exploring image domain sparsity via an optimization approach. The objective function contains four terms. A data-fidelity term ensures themore » fidelity between the identified material densities and the DECT images, while the other three terms enforces the sparsity in the gradient domain of the three images corresponding to the density of the base materials by using total variation (TV) regularization. A primal-dual algorithm is applied to solve the proposed optimization problem. We have performed simulation studies to test this model. Results: Our digital phantom in the tests contains water, bone regions and gold inserts of different sizes and densities. The gold inserts contain mixed material consisting of water with 1g/cm3 and gold at a certain density. At a low gold density of 0.0008 g/cm3, the insert is hardly visible in DECT images, especially for those with small sizes. Our algorithm is able to decompose the DECT into three density images. Those gold inserts at a low density can be clearly visualized in the density image. Conclusion: We have developed a new algorithm to decompose DECT images into three different material density images, in particular, to retrieve density of gold. Numerical studies showed promising results.« less

Design and material selection for inverter transformer cores

NASA Technical Reports Server (NTRS)

Mclyman, W. T.

1973-01-01

Report is announced which studied magnetic properties of candidate materials for use in spacecraft transformers, static inverters, converters, and transformer-rectifier power supplies. Included are material characteristics for available alloy compositions in tabular form, including: trade names, saturated flux density, dc coercive force, loop squareness, material density, and watts per pound at 3 KHz.

A density distribution algorithm for bone incorporating local orthotropy, modal analysis and theories of cellular solids.

PubMed

Impelluso, Thomas J

2003-06-01

An algorithm for bone remodeling is presented which allows for both a redistribution of density and a continuous change of principal material directions for the orthotropic material properties of bone. It employs a modal analysis to add density for growth and a local effective strain based analysis to redistribute density. General re-distribution functions are presented. The model utilizes theories of cellular solids to relate density and strength. The code predicts the same general density distributions and local orthotropy as observed in reality.

Ultra-Low Density Organic-Inorganic Composite Materials Possessing Thermally Insulating and Acoustic Damping Properties

DTIC Science & Technology

1992-05-07

Officer. Dr. Kenneth Wynne d. Brief Description of Project- We are investigating the design and synthesis of strong, ultra-low density xerogel and aerogel ...materials of this type would have applications in a broad range of areas including lightweight engine components, high temperature coatings, aircraft wings...we plan to investigate the formation of ultra-low density composites using supercritical universal drying (SCUD) techniques. SiO2 aerogel materials

Potential techniques for non-destructive evaluation of cable materials

NASA Astrophysics Data System (ADS)

Gillen, Kenneth T.; Clough, Roger L.; Mattson, Bengt; Stenberg, Bengt; Oestman, Erik

This paper describes the connection between mechanical degradation of common cable materials, in radiation and elevated temperature environments, and density increases caused by the oxidation which leads to this degradation. Two techniques based on density changes are suggested as potential non-destructive evaluation (NDE) procedures which may be applicable to monitoring the mechanical condition of cable materials in power plant environments. The first technique is direct measurement of density changes, via a density gradient column, using small shavings removed from the surface of cable jackets at selected locations. The second technique is computed X-ray tomography, utilizing a portable scanning device.

Multiple density layered insulator

DOEpatents

Alger, Terry W.

1994-01-01

A multiple density layered insulator for use with a laser is disclosed wh provides at least two different insulation materials for a laser discharge tube, where the two insulation materials have different thermoconductivities. The multiple layer insulation materials provide for improved thermoconductivity capability for improved laser operation.

Quantum coherent switch utilizing commensurate nanoelectrode and charge density periodicities

DOEpatents

Harrison,; Neil, Singleton [Santa Fe, NM; John, Migliori [Los Alamos, NM; Albert, [Santa Fe, NM

2008-08-05

A quantum coherent switch having a substrate formed from a density wave (DW) material capable of having a periodic electron density modulation or spin density modulation, a dielectric layer formed onto a surface of the substrate that is orthogonal to an intrinsic wave vector of the DW material; and structure for applying an external spatially periodic electrostatic potential over the dielectric layer.

Magnetic and Electrical Characteristics of Cobalt-Based Amorphous Materials and Comparison to a Permalloy Type Polycrystalline Material

NASA Technical Reports Server (NTRS)

Wieserman, William R.; Schwarze, Gene E.; Niedra, Janis M.

2005-01-01

Magnetic component designers are always looking for improved soft magnetic core materials to increase the efficiency, temperature rating and power density of transformers, motors, generators and alternators, and energy density of inductors. In this paper, we report on the experimental investigation of commercially available cobalt-based amorphous alloys which, in their processing, were subjected to two different types of magnetic field anneals: A longitudinal magnetic field anneal or a transverse magnetic field anneal. The longitudinal field annealed material investigated was Metglas 2714A. The electrical and magnetic characteristics of this material were investigated over the frequency range of 1 to 200 kHz and temperature range of 23 to 150 C for both sine and square wave voltage excitation. The specific core loss was lower for the square than the sine wave voltage excitation for the same maximum flux density, frequency and temperature. The transverse magnetic field annealed core materials include Metglas 2714AF and Vacuumschmelze 6025F. These two materials were experimentally characterized over the frequency range of 10 to 200 kHz for sine wave voltage excitation and 23 C only. A comparison of the 2174A to 2714AF found that 2714AF always had lower specific core loss than 2714A for any given magnetic flux density and frequency and the ratio of specific core loss of 2714A to 2714AF was dependent on both magnetic flux density and frequency. A comparison was also made of the 2714A, 2714AF, and 6025F materials to two different tape thicknesses of the polycrystalline Supermalloy material and the results show that 2714AF and 6025F have the lowest specific core loss at 100 kHz over the magnetic flux density range of 0.1 to 0.4 Tesla.

A new accurate and flexible index to assess the contribution of building materials to indoor gamma exposure.

PubMed

Nuccetelli, Cristina; Leonardi, Federica; Trevisi, Rosabianca

2015-05-01

The role of building materials as a source of gamma radiation has been recognized in the new EU Basic Safety Standards Directive which introduces an index I to screen building materials of radiological concern. This index was developed to account for average concrete values of thickness and density, the main structural characteristics of building materials that have an effect on gamma irradiation. Consequently, this screening procedure could be unfit in case of significantly different density and/or thickness of the building materials under examination. The paper proposes a more accurate and flexible activity concentration index, accounting for the actual density and thickness of building materials. Copyright © 2015 Elsevier Ltd. All rights reserved.

Impact of the material composition on proton range variation - A Monte Carlo study

NASA Astrophysics Data System (ADS)

Wu, S. W.; Tung, C. J.; Lee, C. C.; Fan, K. H.; Huang, H. C.; Chao, T. C.

2015-11-01

In this study, we used the Geant4 toolkit to demonstrate the impacts of the material composition of tissues on proton range variation. Bragg curves of different materials subjected to a 250 MeV mono-energy proton beam were simulated and compared. These simulated materials included adipose, heart, brain, cartilage, cortical bone and water. The results showed that there was significant proton range deviation between Bragg curves, especially for cortical bone. The R50 values for a 250 MeV proton beam were approximately 39.55 cm, 35.52 cm, 37.00 cm, 36.51 cm, 36.72 cm, 22.53 cm, and 38.52 cm in the phantoms that were composed completely of adipose, cartilage, tissue, heart, brain, cortical bone, and water, respectively. Mass density and electron density were used to scale the proton range for each material; electron density provided better range scaling. In addition, a similar comparison was performed by artificially setting all material density to 1.0 g/cm3 to evaluate the range deviation due to chemical components alone. Tissue heterogeneity effects due to density variation were more significant, and less significant for chemical composition variation unless the Z/A was very different.

Multiple density layered insulator

DOEpatents

Alger, T.W.

1994-09-06

A multiple density layered insulator for use with a laser is disclosed which provides at least two different insulation materials for a laser discharge tube, where the two insulation materials have different thermoconductivities. The multiple layer insulation materials provide for improved thermoconductivity capability for improved laser operation. 4 figs.

Development of inert density mock materials for HMX

DOE PAGES

Yeager, John D.; Higginbotham Duque, Amanda L.; Shorty, Marvin; ...

2017-09-22

Inert surrogates or mocks for high explosives are commonly used in place of the real material for complex experiments or in situations where safety is a concern. We tested several materials as potential mocks for HMX in terms of density, thermal stability, and processability. Selection criteria were developed and a literature search was conducted primarily using the Cambridge Structural Database. Moreover, out of over 200 potentially acceptable materials, six were chosen for crystallization experiments and a suite of analytical characterization. Of these six, 5-iodo-2'-deoxyuridine, N,N'-bis(2,3,4,5,6-pentafluorophenyl)oxamide, and 2,3,4,5,6-pentafluorobenzamide all were found to be thermally stable at 150°C, matched HMX density asmore » a pressed pellet, and could be crystallized to appropriate particle sizes. These three materials are considered suitable inert density mocks for HMX and will be the subject of future testing.« less

First-Principles Prediction of Densities of Amorphous Materials: The Case of Amorphous Silicon

NASA Astrophysics Data System (ADS)

Furukawa, Yoritaka; Matsushita, Yu-ichiro

2018-02-01

A novel approach to predict the atomic densities of amorphous materials is explored on the basis of Car-Parrinello molecular dynamics (CPMD) in density functional theory. Despite the determination of the atomic density of matter being crucial in understanding its physical properties, no first-principles method has ever been proposed for amorphous materials until now. We have extended the conventional method for crystalline materials in a natural manner and pointed out the importance of the canonical ensemble of the total energy in the determination of the atomic densities of amorphous materials. To take into account the canonical distribution of the total energy, we generate multiple amorphous structures with several different volumes by CPMD simulations and average the total energies at each volume. The density is then determined as the one that minimizes the averaged total energy. In this study, this approach is implemented for amorphous silicon (a-Si) to demonstrate its validity, and we have determined the density of a-Si to be 4.1% lower and its bulk modulus to be 28 GPa smaller than those of the crystal, which are in good agreement with experiments. We have also confirmed that generating samples through classical molecular dynamics simulations produces a comparable result. The findings suggest that the presented method is applicable to other amorphous systems, including those for which experimental knowledge is lacking.

Photovoltaic and thermophotovoltaic devices with quantum barriers

DOEpatents

Wernsman, Bernard R [Jefferson Hills, PA

2007-04-10

A photovoltaic or thermophotovoltaic device includes a diode formed by p-type material and n-type material joined at a p-n junction and including a depletion region adjacent to said p-n junction, and a quantum barrier disposed near or in the depletion region of the p-n junction so as to decrease device reverse saturation current density while maintaining device short circuit current density. In one embodiment, the quantum barrier is disposed on the n-type material side of the p-n junction and decreases the reverse saturation current density due to electrons while in another, the barrier is disposed on the p-type material side of the p-n junction and decreases the reverse saturation current density due to holes. In another embodiment, both types of quantum barriers are used.

Method to reduce dislocation density in silicon using stress

DOEpatents

Buonassisi, Anthony; Bertoni, Mariana; Argon, Ali; Castellanos, Sergio; Fecych, Alexandria; Powell, Douglas; Vogl, Michelle

2013-03-05

A crystalline material structure with reduced dislocation density and method of producing same is provided. The crystalline material structure is annealed at temperatures above the brittle-to-ductile transition temperature of the crystalline material structure. One or more stress elements are formed on the crystalline material structure so as to annihilate dislocations or to move them into less harmful locations.

Acquisition of an Advanced Thermal Analysis andImaging System for Integration with Interdisciplinary Researchand Education in Low Density Organic Inorganic Materials

DTIC Science & Technology

2017-12-02

Report: Acquisition of an Advanced Thermal Analysis and Imaging System for Integration with Interdisciplinary Research and Education in Low Density...for Integration with Interdisciplinary Research and Education in Low Density Organic-Inorganic Materials Report Term: 0-Other Email: dmisra2

Mechanical properties in crumple-formed paper derived materials subjected to compression.

PubMed

Hanaor, D A H; Flores Johnson, E A; Wang, S; Quach, S; Dela-Torre, K N; Gan, Y; Shen, L

2017-06-01

The crumpling of precursor materials to form dense three dimensional geometries offers an attractive route towards the utilisation of minor-value waste materials. Crumple-forming results in a mesostructured system in which mechanical properties of the material are governed by complex cross-scale deformation mechanisms. Here we investigate the physical and mechanical properties of dense compacted structures fabricated by the confined uniaxial compression of a cellulose tissue to yield crumpled mesostructuring. A total of 25 specimens of various densities were tested under compression. Crumple formed specimens exhibited densities in the range 0.8-1.3 g cm -3 , and showed high strength to weight characteristics, achieving ultimate compressive strength values of up to 200 MPa under both quasi-static and high strain rate loading conditions and deformation energy that compares well to engineering materials of similar density. The materials fabricated in this work and their mechanical attributes demonstrate the potential of crumple-forming approaches in the fabrication of novel energy-absorbing materials from low-cost precursors such as recycled paper. Stiffness and toughness of the materials exhibit density dependence suggesting this forming technique further allows controllable impact energy dissipation rates in dynamic applications.

Preliminary research on dual-energy X-ray phase-contrast imaging

NASA Astrophysics Data System (ADS)

Han, Hua-Jie; Wang, Sheng-Hao; Gao, Kun; Wang, Zhi-Li; Zhang, Can; Yang, Meng; Zhang, Kai; Zhu, Pei-Ping

2016-04-01

Dual-energy X-ray absorptiometry (DEXA) has been widely applied to measure the bone mineral density (BMD) and soft-tissue composition of the human body. However, the use of DEXA is greatly limited for low-Z materials such as soft tissues due to their weak absorption, while X-ray phase-contrast imaging (XPCI) shows significantly improved contrast in comparison with the conventional standard absorption-based X-ray imaging for soft tissues. In this paper, we propose a novel X-ray phase-contrast method to measure the area density of low-Z materials, including a single-energy method and a dual-energy method. The single-energy method is for the area density calculation of one low-Z material, while the dual-energy method aims to calculate the area densities of two low-Z materials simultaneously. Comparing the experimental and simulation results with the theoretical ones, the new method proves to have the potential to replace DEXA in area density measurement. The new method sets the prerequisites for a future precise and low-dose area density calculation method for low-Z materials. Supported by Major State Basic Research Development Program (2012CB825800), Science Fund for Creative Research Groups (11321503) and National Natural Science Foundation of China (11179004, 10979055, 11205189, 11205157)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Michael, Stephan; Chow, Weng; Schneider, Hans

In the framework of a microscopic model for intersubband gain from electrically pumped quantum-dot structures we investigate electrically pumped quantum-dots as active material for a mid-infrared quantum cascade laser. Our previous calculations have indicated that these structures could operate with reduced threshold current densities while also achieving a modal gain comparable to that of quantum well active materials. We study the influence of two important quantum-dot material parameters, here, namely inhomogeneous broadening and quantum-dot sheet density, on the performance of a proposed quantum cascade laser design. In terms of achieving a positive modal net gain, a high quantum-dot density canmore » compensate for moderately high inhomogeneous broadening, but at a cost of increased threshold current density. By minimizing quantum-dot density with presently achievable inhomogeneous broadening and total losses, significantly lower threshold densities than those reported in quantum-well quantum-cascade lasers are predicted by our theory.« less

Material Density Distribution of Small Debris in Earth Orbit

NASA Technical Reports Server (NTRS)

Krisko, P. H.; Xu, Y.-l.; Opiela, J. N.; Hill, N. M.; Matney, M. J.

2008-01-01

Over 200 spacecraft and rocket body breakups in Earth orbit have populated that regime with debris fragments in the sub-micron through meter size range. Though the largest debris fragments can cause significant collisional damage to active (operational) spacecraft, these are few and trackable by radar. Fragments on the order of a millimeter to a centimeter in size are as yet untrackable. But this smaller debris can result in damage to critical spacecraft systems and, under the worst conditions, fragmenting collision events. Ongoing research at the NASA Orbital Debris Program Office on the sources of these small fragments has focused on the material components of spacecraft and rocket bodies and on breakup event morphology. This has led to fragment material density estimates, and also the beginnings of shape categorizations. To date the NASA Standard Breakup Model has not considered specific material density distinctions of small debris. The basis of small debris in that model is the fourth hypervelocity impact event of the Satellite Orbital Debris Characterization Impact Test (SOCIT) series. This test targeted a flight-ready, U.S. Transit navigation satellite with a solid aluminum sphere impactor. Results in this event yield characteristic length (size) and area-to-mass distributions of fragments smaller than 10 cm in the NASA model. Recent re-analysis of the SOCIT4 small fragment dataset highlighted the material-specific characteristics of metals and non-metals. Concurrent analysis of Space Shuttle in-situ impact data showed a high percentage of aluminum debris in shuttle orbit regions. Both analyses led to the definition of three main on-orbit debris material density categories -low density (< 2 g/cc), medium density (2 to 6 g/cc), and high density (> 6 g/cc). This report considers the above studies in an explicit extension of the NASA Standard Breakup Model where separate material densities for debris are generated and these debris fragments are propagated in Earth orbit. The near Earth environment is thus parameterized by debris density percentages within subsections of that environment. This model version is used in the upgraded NASA Orbital Debris Engineering Model (ORDEM).

Using Muons to Image the Subsurface.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bonal, Nedra; Cashion, Avery Ted; Cieslewski, Grzegorz

Muons are subatomic particles that can penetrate the earth 's crust several kilometers and may be useful for subsurface characterization . The absorption rate of muons depends on the density of the materials through which they pass. Muons are more sensitive to density variation than other phenomena, including gravity, making them beneficial for subsurface investigation . Measurements of muon flux rate at differing directions provide density variations of the materials between the muon source (cosmic rays and neutrino interactions) and the detector, much like a CAT scan. Currently, muon tomography can resolve features to the sub-meter scale. This work consistsmore » of three parts to address the use of muons for subsurface characterization : 1) assess the use of muon scattering for estimating density differences of common rock types, 2 ) using muon flux to detect a void in rock, 3) measure muon direction by designing a new detector. Results from this project lay the groundwork for future directions in this field. Low-density objects can be detected by muons even when enclosed in high-density material like lead, and even small changes in density (e.g. changes due to fracturing of material) can be detected. Rock density has a linear relationship with muon scattering density per rock volume when this ratio is greater than 0.10 . Limitations on using muon scattering to assess density changes among common rock types have been identified. However, other analysis methods may show improved results for these relatively low density materials. Simulations show that muons can be used to image void space (e.g. tunnels) within rock but experimental results have been ambiguous. Improvements are suggested to improve imaging voids such as tunnels through rocks. Finally, a muon detector has been designed and tested to measure muon direction, which will improve signal-to-noise ratio and help address fundamental questions about the source of upgoing muons .« less

Sol-gel Technology and Advanced Electrochemical Energy Storage Materials

NASA Technical Reports Server (NTRS)

Chu, Chung-tse; Zheng, Haixing

1996-01-01

Advanced materials play an important role in the development of electrochemical energy devices such as batteries, fuel cells, and electrochemical capacitors. The sol-gel process is a versatile solution for use in the fabrication of ceramic materials with tailored stoichiometry, microstructure, and properties. This processing technique is particularly useful in producing porous materials with high surface area and low density, two of the most desirable characteristics for electrode materials. In addition,the porous surface of gels can be modified chemically to create tailored surface properties, and inorganic/organic micro-composites can be prepared for improved material performance device fabrication. Applications of several sol-gel derived electrode materials in different energy storage devices are illustrated in this paper. V2O5 gels are shown to be a promising cathode material for solid state lithium batteries. Carbon aerogels, amorphous RuO2 gels and sol-gel derived hafnium compounds have been studied as electrode materials for high energy density and high power density electrochemical capacitors.

Scattered image artifacts from cone beam computed tomography and its clinical potential in bone mineral density estimation.

PubMed

Ko, Hoon; Jeong, Kwanmoon; Lee, Chang-Hoon; Jun, Hong Young; Jeong, Changwon; Lee, Myeung Su; Nam, Yunyoung; Yoon, Kwon-Ha; Lee, Jinseok

2016-01-01

Image artifacts affect the quality of medical images and may obscure anatomic structure and pathology. Numerous methods for suppression and correction of scattered image artifacts have been suggested in the past three decades. In this paper, we assessed the feasibility of use of information on scattered artifacts for estimation of bone mineral density (BMD) without dual-energy X-ray absorptiometry (DXA) or quantitative computed tomographic imaging (QCT). To investigate the relationship between scattered image artifacts and BMD, we first used a forearm phantom and cone-beam computed tomography. In the phantom, we considered two regions of interest-bone-equivalent solid material containing 50 mg HA per cm(-3) and water-to represent low- and high-density trabecular bone, respectively. We compared the scattered image artifacts in the high-density material with those in the low-density material. The technique was then applied to osteoporosis patients and healthy subjects to assess its feasibility for BMD estimation. The high-density material produced a greater number of scattered image artifacts than the low-density material. Moreover, the radius and ulna of healthy subjects produced a greater number of scattered image artifacts than those from osteoporosis patients. Although other parameters, such as bone thickness and X-ray incidence, should be considered, our technique facilitated BMD estimation directly without DXA or QCT. We believe that BMD estimation based on assessment of scattered image artifacts may benefit the prevention, early treatment and management of osteoporosis.

High performance all-solid-state symmetric supercapacitor based on porous carbon made from a metal-organic framework compound

NASA Astrophysics Data System (ADS)

Yu, Feng; Wang, Teng; Wen, Zubiao; Wang, Hongxia

2017-10-01

In this work, we demonstrate the synthesis of porous carbon material with high specific surface area by using metal-organic framework (MOF) as precursor. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) have confirmed that the material was amorphous and consisted of nanoparticles (5-6 nm) and hierarchical distribution of pores. The characterization of the material by N2 adsorption/desorption isotherm measurement have shown that the material had a high specific surface area reaching to 2618.7 m2 g-1 and abundant porosity with pore size less than 10 nm. The investigation of the electrochemical properties of the material has shown the porous carbon electrode possessed excellent rate performance with high specific capacitances of 150.8 F g-1 at a current density of 5 A g-1, and 133.6 F g-1 at a current density of 50 A g-1, respectively. An all-solid-state symmetric supercapacitor assembled using the as-prepared porous carbon as electrodes and Na2SO4/PVA gel as an electrolyte delivered a high power density of 13 516.4 W kg-1 with an energy density of 8.26 Wh kg-1. A high energy density of 17.37 Wh kg-1 was obtained at discharge current density of 1 A g-1. In addition, the device exhibited superior cycling performance with 94.8% retention rate after 10 000 cycles at a current density of 10 A g-1.

Flexible Ablators

NASA Technical Reports Server (NTRS)

Stackpoole, Margaret M. (Inventor); Ghandehari, Ehson M. (Inventor); Thornton, Jeremy J. (Inventor); Covington, Melmoth Alan (Inventor)

2017-01-01

A low-density article comprising a flexible substrate and a pyrolizable material impregnated therein, methods of preparing, and devices using the article are disclosed. The pyrolizable material pyrolizes above 350 C and does not flow at temperatures below the pyrolysis temperature. The low-density article remains flexible after impregnation and continues to remain flexible when the pyrolizable material is fully pyrolized.

Enhanced energy harvesting in commercial ferroelectric materials

NASA Astrophysics Data System (ADS)

Patel, Satyanarayan; Chauhan, Aditya; Vaish, Rahul

2014-04-01

Ferroelectric materials are used in a number of applications ranging from simple sensors and actuators to ferroelectric random access memories (FRAMs), transducers, health monitoring system and microelectronics. The multiphysical coupling ability possessed by these materials has been established to be useful for energy harvesting applications. However, conventional energy harvesting techniques employing ferroelectric materials possess low energy density. This has prevented the successful commercialization of ferroelectric based energy harvesting systems. In this context, the present study aims at proposing a novel approach for enhanced energy harvesting using commercially available ferroelectric materials. This technique was simulated to be used for two commercially available piezoelectric materials namely PKI-552 and APCI-840, soft and hard lead-zirconate-titanate (PZT) pervoskite ceramics, respectively. It was observed that a maximum energy density of 348 kJm-3cycle-1 can be obtained for cycle parameters of (0-1 ton compressive stress and 1-25 kV.cm-1 electric field) using APCI-840. The reported energy density is several hundred times larger than the maximum energy density reported in the literature for vibration harvesting systems.

Stochastic transport models for mixing in variable-density turbulence

NASA Astrophysics Data System (ADS)

Bakosi, J.; Ristorcelli, J. R.

2011-11-01

In variable-density (VD) turbulent mixing, where very-different- density materials coexist, the density fluctuations can be an order of magnitude larger than their mean. Density fluctuations are non-negligible in the inertia terms of the Navier-Stokes equation which has both quadratic and cubic nonlinearities. Very different mixing rates of different materials give rise to large differential accelerations and some fundamentally new physics that is not seen in constant-density turbulence. In VD flows material mixing is active in a sense far stronger than that applied in the Boussinesq approximation of buoyantly-driven flows: the mass fraction fluctuations are coupled to each other and to the fluid momentum. Statistical modeling of VD mixing requires accounting for basic constraints that are not important in the small-density-fluctuation passive-scalar-mixing approximation: the unit-sum of mass fractions, bounded sample space, and the highly skewed nature of the probability densities become essential. We derive a transport equation for the joint probability of mass fractions, equivalent to a system of stochastic differential equations, that is consistent with VD mixing in multi-component turbulence and consistently reduces to passive scalar mixing in constant-density flows.

Effects of true density, compacted mass, compression speed, and punch deformation on the mean yield pressure.

PubMed

Gabaude, C M; Guillot, M; Gautier, J C; Saudemon, P; Chulia, D

1999-07-01

Compressibility properties of pharmaceutical materials are widely characterized by measuring the volume reduction of a powder column under pressure. Experimental data are commonly analyzed using the Heckel model from which powder deformation mechanisms are determined using mean yield pressure (Py). Several studies from the literature have shown the effects of operating conditions on the determination of Py and have pointed out the limitations of this model. The Heckel model requires true density and compacted mass values to determine Py from force-displacement data. It is likely that experimental errors will be introduced when measuring the true density and compacted mass. This study investigates the effects of true density and compacted mass on Py. Materials having different particle deformation mechanisms are studied. Punch displacement and applied pressure are measured for each material at two compression speeds. For each material, three different true density and compacted mass values are utilized to evaluate their effect on Py. The calculated variation of Py reaches 20%. This study demonstrates that the errors in measuring true density and compacted mass have a greater effect on Py than the errors incurred from not correcting the displacement measurements due to punch elasticity.

Use of silicon carbide sludge to form porous alkali-activated materials for insulating application

NASA Astrophysics Data System (ADS)

Prud'homme, E.; Joussein, E.; Rossignol, S.

2015-07-01

One of the objectives in the field of alkali-activated materials is the development of materials having greater thermal performances than conventional construction materials such as aerated concrete. The aim of this paper is to present the possibility to obtain controlled porosity and controlled thermal properties with geopolymer materials including a waste like silicon carbide sludge. The porosity is created by the reaction of free silicon contains in silicon carbide sludge leading to the formation of hydrogen. Two possible ways are investigated to control the porosity: modification of mixture formulation and additives introduction. The first way is the most promising and allowed the formation of materials presenting the same density but various porosities, which shows that the material is adaptable to the application. The insulation properties are logically linked to the porosity and density of materials. A lower value of thermal conductivity of 0.075 W.m-1.K-1 can be reached for a material with a low density of 0.27 g.cm-3. These characteristics are really good for a mineral-based material which always displays non-negligible resistance to manipulation.

Unreacted Hugoniots for porous and liquid explosives

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gustavsen, R.L.; Sheffield, S.A.

1993-08-01

Numerous authors have measured the Hugoniots of a variety of granular explosives pressed to different densities. Each explosive at each density was typically then treated as a unique material having its own Hugoniot. By combining methods used by Hayes, Sheffield and Mitchell (for describing the Hugoniot of HNS at various densities) with Hermann`s P-{alpha} model, it is only necessary to know some thermodynamic constants or the Hugoniot of the initially solid material and the porous material sound speed to obtain accurate unreacted Hugoniots for the porous explosive. We discuss application of this method to several materials including HMX, PETN, TNT,more » and Tetryl, as well as HNS. We also show that the ``Universal Liquid Hugoniot`` can be used to calculate the unreacted Hugoniot for liquid explosives. With this method only the ambient pressure sound speed and density are needed to predict the Hugoniot. Applications presented include nitromethane and liquid TNT.« less

Magnetic properties measurement of soft magnetic composite material (SOMALOY 700) by using 3-D tester

NASA Astrophysics Data System (ADS)

Asari, Ashraf; Guo, Youguang; Zhu, Jianguo

2017-08-01

Core losses of rotating electrical machine can be predicted by identifying the magnetic properties of the magnetic material. The magnetic properties should be properly measured since there are some variations of vector flux density in the rotating machine. In this paper, the SOMALOY 700 material has been measured under x, y and z- axes flux density penetration by using the 3-D tester. The calibrated sensing coils are used in detecting the flux densities which have been generated by the Labview software. The measured sensing voltages are used in obtaining the magnetic properties of the sample such as magnetic flux density B, magnetic field strength H, hysteresis loop which can be used to calculate the total core loss of the sample. The results of the measurement are analyzed by using the Mathcad software before being compared to another material.

Evaluation of the effect of custom burr holes on a surgeon's sense of screw fixation in revision porous metal cups.

PubMed

Nyland, Mark A; Lanting, Brent A; Nikolov, Hristo N; Somerville, Lyndsay E; Teeter, Matthew G; Howard, James L

2016-12-01

It is common practice to burr custom holes in revision porous metal cups for screw insertion. The objective of this study was to determine how different hole types affect a surgeon's sense of screw fixation. Porous revision cups were prepared with pre-drilled and custom burred holes. Cups were held in place adjacent to synthetic bone material of varying density. Surgeons inserted screws through the different holes and materials. Surgeon subjective rating, compression, and torque was recorded. The torque achieved was greater ( p  = 0.002) for screws through custom holes than pre-fabricated holes in low and medium density material, with no difference for high density. Peak compression was greater ( p  = 0.026) through the pre-fabricated holes only in high density material. Use of burred holes affects the torque generated, and may decrease the amount of cup-acetabulum compression achieved.

Precision measurements of linear scattering density using muon tomography

NASA Astrophysics Data System (ADS)

Åström, E.; Bonomi, G.; Calliari, I.; Calvini, P.; Checchia, P.; Donzella, A.; Faraci, E.; Forsberg, F.; Gonella, F.; Hu, X.; Klinger, J.; Sundqvist Ökvist, L.; Pagano, D.; Rigoni, A.; Ramous, E.; Urbani, M.; Vanini, S.; Zenoni, A.; Zumerle, G.

2016-07-01

We demonstrate that muon tomography can be used to precisely measure the properties of various materials. The materials which have been considered have been extracted from an experimental blast furnace, including carbon (coke) and iron oxides, for which measurements of the linear scattering density relative to the mass density have been performed with an absolute precision of 10%. We report the procedures that are used in order to obtain such precision, and a discussion is presented to address the expected performance of the technique when applied to heavier materials. The results we obtain do not depend on the specific type of material considered and therefore they can be extended to any application.

Nanostructured mesoporous materials for lithium-ion battery applications

NASA Astrophysics Data System (ADS)

Balaya, P.; Saravanan, K.; Hariharan, S.; Ramar, V.; Lee, H. S.; Kuezma, M.; Devaraj, S.; Nagaraju, D. H.; Ananthanarayanan, K.; Mason, C. W.

2011-06-01

The Energy crisis happens to be one of the greatest challenges we are facing today. In this view, much effort has been made in developing new, cost effective, environmentally friendly energy conversion and storage devices. The performance of such devices is fundamentally related to material properties. Hence, innovative materials engineering is important in solving the energy crisis problem. One such innovation in materials engineering is porous materials for energy storage. Porous electrode materials for lithium-ion batteries (LIBs) offer a high degree of electrolyte-electrode wettability, thus enhancing the electrochemical activity within the material. Among the porous materials, mesoporous materials draw special attention, owing to shorter diffusion lengths for Li+ and electronic movement. Nanostructured mesoporous materials also offer better packing density compared to their nanostructured counterparts such as nanopowders, nanowires, nanotubes etc., thus opening a window for developing electrode materials with high volumetric energy densities. This would directly translate into a scenario of building batteries which are much lighter than today's commercial LIBs. In this article, the authors present a simple, soft template approach for preparing both cathode and anode materials with high packing density for LIBs. The impact of porosity on the electrochemical storage performance is highlighted.

Evaluation of potential site for mineral processing plant

NASA Astrophysics Data System (ADS)

Izwan Ishak, Muhamad Noor; Sipaun, Susan Maria; Mustapha, Ismail; Fahmi Engku Chik, Engku Mohd; Abdullah, Nurliyana; Affandi Mahmood, Airwan

2018-01-01

Nuclear moisture-density gauge is a type of instrument for measuring density and moisture of the material in a relatively thin zone beneath a surface of the material by using low activity of neutron and gamma radiation source. Density and moisture content data of the compacted layers are needed to determine the degree of compaction of soils, aggregate, concrete, asphalt or other materials used in civil engineering works. A gamma radiation source is mounted inside gauge housing with the source rod vertically extended to various depth positions. Direct transmission gamma radiation technique is used to obtain the count reading for the number of photons emitted before it is converted into density reading by microprocessor. This paper presents the inspection technique and results for the measurement of soil moisture and density carried out at potential site for mineral processing plant, Malaysian Nuclear Agency. Primarily, the experiment was conducted to ensure the compaction of ground is suitable for the plant construction. From the calculation, the percentages of soil wet density compaction (%WD Compact) are within acceptable limits with respect to the standard compacted wet soil density measured in the laboratory.

Mid-Infrared Quantum-Dot Quantum Cascade Laser: A Theoretical Feasibility Study

DOE PAGES

Michael, Stephan; Chow, Weng; Schneider, Hans

2016-05-01

In the framework of a microscopic model for intersubband gain from electrically pumped quantum-dot structures we investigate electrically pumped quantum-dots as active material for a mid-infrared quantum cascade laser. Our previous calculations have indicated that these structures could operate with reduced threshold current densities while also achieving a modal gain comparable to that of quantum well active materials. We study the influence of two important quantum-dot material parameters, here, namely inhomogeneous broadening and quantum-dot sheet density, on the performance of a proposed quantum cascade laser design. In terms of achieving a positive modal net gain, a high quantum-dot density canmore » compensate for moderately high inhomogeneous broadening, but at a cost of increased threshold current density. By minimizing quantum-dot density with presently achievable inhomogeneous broadening and total losses, significantly lower threshold densities than those reported in quantum-well quantum-cascade lasers are predicted by our theory.« less

A novel algorithm using an orthotropic material model for topology optimization

NASA Astrophysics Data System (ADS)

Tong, Liyong; Luo, Quantian

2017-09-01

This article presents a novel algorithm for topology optimization using an orthotropic material model. Based on the virtual work principle, mathematical formulations for effective orthotropic material properties of an element containing two materials are derived. An algorithm is developed for structural topology optimization using four orthotropic material properties, instead of one density or area ratio, in each element as design variables. As an illustrative example, minimum compliance problems for linear and nonlinear structures are solved using the present algorithm in conjunction with the moving iso-surface threshold method. The present numerical results reveal that: (1) chequerboards and single-node connections are not present even without filtering; (2) final topologies do not contain large grey areas even using a unity penalty factor; and (3) the well-known numerical issues caused by low-density material when considering geometric nonlinearity are resolved by eliminating low-density elements in finite element analyses.

Structure and characteristics of functional powder composite materials obtained by spark plasma sintering

NASA Astrophysics Data System (ADS)

Oglezneva, S. A.; Kachenyuk, M. N.; Kulmeteva, V. B.; Ogleznev, N. B.

2017-07-01

The article describes the results of spark plasma sintering of ceramic materials based on titanium carbide, titanium carbosilicide, ceramic composite materials based on zirconium oxide, strengthened by carbon nanostructures and composite materials of electrotechnical purpose based on copper with addition of carbon structures and titanium carbosilicide. The research shows that the spark plasma sintering can achieve relative density of the material up to 98%. The effect of sintering temperature on the phase composition, density and porosity of the final product has been studied. It was found that with addition of carbon nanostructures the relative density and hardness decrease, but the fracture strength of ZrO2 increases up to times 2. The relative erosion resistance of the electrodes made of composite copper-based powder materials, obtained by spark plasma sintering during electroerosion treatment of tool steel exceeds that parameter of pure copper up to times 15.

Method for determining transport critical current densities and flux penetration depth in bulk superconductors

NASA Technical Reports Server (NTRS)

Israelsson, Ulf E. (Inventor); Strayer, Donald M. (Inventor)

1992-01-01

A contact-less method for determining transport critical current density and flux penetration depth in bulk superconductor material. A compressor having a hollow interior and a plunger for selectively reducing the free space area for distribution of the magnetic flux therein are formed of superconductor material. Analytical relationships, based upon the critical state model, Maxwell's equations and geometrical relationships define transport critical current density and flux penetration depth in terms of the initial trapped magnetic flux density and the ratio between initial and final magnetic flux densities whereby data may be reliably determined by means of the simple test apparatus for evaluating the current density and flux penetration depth.

Advanced rechargeable sodium batteries with novel cathodes

NASA Technical Reports Server (NTRS)

Distefano, S.; Ratnakumar, B. V.; Bankston, C. P.

1989-01-01

Various high energy density rechargeable batteries are being considered for future space applications. Of these, the sodium sulfur battery is one of the leading candidates. The primary advantage is the high energy density (760 Wh/kg theoretical). Energy densities in excess of 180 Wh/kg have been realized in practical batteries. More recently, cathodes other than sulfur are being evaluated. Researchers at JPL are evaluating various new cathode materials for use in high energy density sodium batteries for advanced space applications. The approach is to carry out basic electrochemical studies of these materials in a sodium cell configuration in order to understand their fundamental behaviors. Thus far studies have focused on alternate metal chlorides such as CuCl2 and organic cathode materials such as tetracyanoethylene (TCNE).

Advanced rechargeable sodium batteries with novel cathodes

NASA Technical Reports Server (NTRS)

Di Stefano, S.; Ratnakumar, B. V.; Bankston, C. P.

1990-01-01

Various high energy density rechargeable batteries are being considered for future space applications. Of these, the sodium-sulfur battery is one of the leading candidates. The primary advantage is the high energy density (760 W h/kg theoretical). Energy densities in excess of 180 W h/kg have been realized in practical batteries. More recently, cathodes other than sulfur are being evaluated. Various new cathode materials are presently being evaluated for use in high energy density sodium batteries for advanced space applications. The approach is to carry out basic electrochemical studies of these materials in a sodium cell configuration in order to understand their fundamental behaviors. Thus far, the studies have focussed on alternative metal chlorides such as CuCl2 and organic cathode materials such as TCNE.

Desorption and Bioavailability of PAHs in Contaminated Soil Subjected to Long-Term In Situ Biostimulation

PubMed Central

Richardson, Stephen D.; Aitken, Michael D.

2011-01-01

The distribution and potential bioavailability of polycyclic aromatic hydrocarbons (PAHs) in soil from a former manufactured-gas plant (MGP) site were examined before and after long-term biostimulation under simulated in situ conditions. Treated soil was collected from the oxygenated zones of two continuous-flow columns, one subjected to biostimulation and the other serving as a control, and separated into low- and high-density fractions. In the original soil, over 50% of the total PAH mass was associated with lower-density particles, which comprised < 2% of the total soil mass. However, desorbable fractions of PAHs were much lower in the low-density material than in the high-density material. After over 500 d of biostimulation, significant removal of total PAHs occurred in both the high- and low-density materials (77% and 53%, respectively), with three- and four-ring PAHs accounting for the majority of the observed mass loss. Total PAHs that desorbed over a 28-d period were substantially lower in treated soil from the biostimulated column than in the original soil for both the high-density material (23 versus 63%) and low-density material (5 versus 20%). The fast-desorbing fractions quantified by a two-site desorption model ranged from 0.1 to 0.5 for most PAHs in the original soil but were essentially zero in the biostimulated soil. The fast-desorbing fractions in the original soil underestimated the extent of PAH biodegradation observed in the biostimulated column, and thus was not a good predictor of PAH bioavailability after long-term, simulated in situ biostimulation. PMID:21932296

Nonlinear dielectric thin films for high-power electric storage with energy density comparable with electrochemical supercapacitors.

PubMed

Yao, Kui; Chen, Shuting; Rahimabady, Mojtaba; Mirshekarloo, Meysam Sharifzadeh; Yu, Shuhui; Tay, Francis Eng Hock; Sritharan, Thirumany; Lu, Li

2011-09-01

Although batteries possess high energy storage density, their output power is limited by the slow movement of charge carriers, and thus capacitors are often required to deliver high power output. Dielectric capacitors have high power density with fast discharge rate, but their energy density is typically much lower than electrochemical supercapacitors. Increasing the energy density of dielectric materials is highly desired to extend their applications in many emerging power system applications. In this paper, we review the mechanisms and major characteristics of electric energy storage with electrochemical supercapacitors and dielectric capacitors. Three types of in-house-produced ferroic nonlinear dielectric thin film materials with high energy density are described, including (Pb(0.97)La(0.02))(Zr(0.90)Sn(0.05)Ti(0.05))O(3) (PLZST) antiferroelectric ceramic thin films, Pb(Zn(1/3)Nb(2/3))O(3-)Pb(Mg(1/3)Nb(2/3))O(3-)PbTiO(3) (PZN-PMN-PT) relaxor ferroelectric ceramic thin films, and poly(vinylidene fluoride) (PVDF)-based polymer blend thin films. The results showed that these thin film materials are promising for electric storage with outstandingly high power density and fairly high energy density, comparable with electrochemical supercapacitors.

Numerical Study on Density Gradient Carbon-Carbon Composite for Vertical Launching System

NASA Astrophysics Data System (ADS)

Yoon, Jin-Young; Kim, Chun-Gon; Lim, Juhwan

2018-04-01

This study presents new carbon-carbon (C/C) composite that has a density gradient within single material, and estimates its heat conduction performance by a numerical method. To address the high heat conduction of a high-density C/C, which can cause adhesion separation in the steel structures of vertical launching systems, density gradient carbon-carbon (DGCC) composite is proposed due to its exhibiting low thermal conductivity as well as excellent ablative resistance. DGCC is manufactured by hybridizing two different carbonization processes into a single carbon preform. One part exhibits a low density using phenolic resin carbonization to reduce heat conduction, and the other exhibits a high density using thermal gradient-chemical vapor infiltration for excellent ablative resistance. Numerical analysis for DGCC is performed with a heat conduction problem, and internal temperature distributions are estimated by the forward finite difference method. Material properties of the transition density layer, which is inevitably formed during DGCC manufacturing, are assumed to a combination of two density layers for numerical analysis. By comparing numerical results with experimental data, we validate that DGCC exhibits a low thermal conductivity, and it can serve as highly effective ablative material for vertical launching systems.

Influence of the first wall material on the particle fuelling in ASDEX Upgrade

NASA Astrophysics Data System (ADS)

Lunt, T.; Reimold, F.; Wolfrum, E.; Carralero, D.; Feng, Y.; Schmid, K.; the ASDEX Upgrade Team

2017-05-01

In the period from 2002 to 2007 the material of the plasma facing components (PFCs) of ASDEX Upgrade (AUG) was changed from carbon (C) to tungsten (W). Comparing the measured density profiles of low-density L-mode discharges with little or no gas puff before and after this modification, a significantly higher pedestal-top density was found for W PFCs together with a steeper gradient and a lower pedestal temperature. This change can be explained by larger particle- and energy reflection coefficients for D on W compared to D on C, as shown by EMC3-EIRENE simulations of AUG discharges in similar conditions on a computational grid extending to the main chamber first wall. In the simulations, a change of the wall material at fixed separatrix density indeed shows that for W PFCs more neutrals cross the separatrix, resulting in a steeper density gradient. Analysis of the source resolved and poloidally resolved neutral flux densities across the separatrix show a dominant contribution of the divertor targets to the fuelling profile in the simulation of the low density case. Increasing the density decreases the electron temperature at the target and therefore the potential drop in the electrostatic sheath as well as the energy of the ions impinging on the surface. Neutrals with ∼eV energies, able to reach the separatrix, are then only produced via molecular dissociation processes in the plasma volume independently of the PFC material. Also the contribution of the main chamber PFCs to the fuelling is observed to increase at higher densities.

Contribution to the beam plasma material interactions during material processing with TEA CO2 laser radiation

NASA Astrophysics Data System (ADS)

Jaschek, Rainer; Konrad, Peter E.; Mayerhofer, Roland; Bergmann, Hans W.; Bickel, Peter G.; Kowalewicz, Roland; Kuttenberger, Alfred; Christiansen, Jens

1995-03-01

The TEA-CO2-laser (transversely excited atmospheric pressure) is a tool for the pulsed processing of materials with peak power densities up to 1010 W/cm2 and a FWHM of 70 ns. The interaction between the laser beam, the surface of the work piece and the surrounding atmosphere as well as gas pressure and the formation of an induced plasma influences the response of the target. It was found that depending on the power density and the atmosphere the response can take two forms. (1) No target modification due to optical break through of the atmosphere and therefore shielding of the target (air pressure above 10 mbar, depending on the material). (2) Processing of materials (air pressure below 10 mbar, depending on the material) with melting of metallic surfaces (power density above 0.5 109 W/cm2), hole formation (power density of 5 109 W/cm2) and shock hardening (power density of 3.5 1010 W/cm2). All those phenomena are usually linked with the occurrence of laser supported combustion waves and laser supported detonation waves, respectively for which the mechanism is still not completely understood. The present paper shows how short time photography and spatial and temporal resolved spectroscopy can be used to better understand the various processes that occur during laser beam interaction. The spectra of titanium and aluminum are observed and correlated with the modification of the target. If the power density is high enough and the gas pressure above a material and gas composition specific threshold, the plasma radiation shows only spectral lines of the background atmosphere. If the gas pressure is below this threshold, a modification of the target surface (melting, evaporation and solid state transformation) with TEA-CO2- laser pulses is possible and the material specific spectra is observed. In some cases spatial and temporal resolved spectroscopy of a plasma allows the calculation of electron temperatures by comparison of two spectral lines.

Advanced Power Electronics Components

NASA Technical Reports Server (NTRS)

Schwarze, Gene E.

2004-01-01

This paper will give a description and status of the Advanced Power Electronics Materials and Components Technology program being conducted by the NASA Glenn Research Center for future aerospace power applications. The focus of this research program is on the following: 1) New and/or significantly improved dielectric materials for the development of power capacitors with increased volumetric efficiency, energy density, and operating temperature. Materials being investigated include nanocrystalline and composite ceramic dielectrics and diamond-like carbon films; 2) New and/or significantly improved high frequency, high temperature, low loss soft magnetic materials for the development of transformers/inductors with increased power/energy density, electrical efficiency, and operating temperature. Materials being investigated include nanocrystalline and nanocomposite soft magnetic materials; 3) Packaged high temperature, high power density, high voltage, and low loss SiC diodes and switches. Development of high quality 4H- and 6H- SiC atomically smooth substrates to significantly improve device performance is a major emphasis of the SiC materials program; 4) Demonstration of high temperature (> 200 C) circuits using the components developed above.

Acoustic Performance of Resilient Materials Using Acrylic Polymer Emulsion Resin.

PubMed

Kim, Haseog; Park, Sangki; Lee, Seahyun

2016-07-19

There have been frequent cases of civil complaints and disputes in relation to floor impact noises over the years. To solve these issues, a substantial amount of sound resilient material is installed between the concrete slab and the foamed concrete during construction. A new place-type resilient material is made from cement, silica powder, sodium sulfate, expanded-polystyrene, anhydrite, fly ash, and acrylic polymer emulsion resin. Its physical characteristics such as density, compressive strength, dynamic stiffness, and remanent strain are analyzed to assess the acoustic performance of the material. The experimental results showed the density and the dynamic stiffness of the proposed resilient material is increased with proportional to the use of cement and silica powder due to the high contents of the raw materials. The remanent strain, related to the serviceability of a structure, is found to be inversely proportional to the density and strength. The amount of reduction in the heavyweight impact noise is significant in a material with high density, high strength, and low remanent strain. Finally, specimen no. R4, having the reduction level of 3 dB for impact ball and 1 dB for bang machine in the single number quantity level, respectively, is the best product to obtain overall acoustic performance.

Acoustic Performance of Resilient Materials Using Acrylic Polymer Emulsion Resin

PubMed Central

Kim, Haseog; Park, Sangki; Lee, Seahyun

2016-01-01

There have been frequent cases of civil complaints and disputes in relation to floor impact noises over the years. To solve these issues, a substantial amount of sound resilient material is installed between the concrete slab and the foamed concrete during construction. A new place-type resilient material is made from cement, silica powder, sodium sulfate, expanded-polystyrene, anhydrite, fly ash, and acrylic polymer emulsion resin. Its physical characteristics such as density, compressive strength, dynamic stiffness, and remanent strain are analyzed to assess the acoustic performance of the material. The experimental results showed the density and the dynamic stiffness of the proposed resilient material is increased with proportional to the use of cement and silica powder due to the high contents of the raw materials. The remanent strain, related to the serviceability of a structure, is found to be inversely proportional to the density and strength. The amount of reduction in the heavyweight impact noise is significant in a material with high density, high strength, and low remanent strain. Finally, specimen no. R4, having the reduction level of 3 dB for impact ball and 1 dB for bang machine in the single number quantity level, respectively, is the best product to obtain overall acoustic performance. PMID:28773711

SU-E-T-470: Importance of HU-Mass Density Calibration Technique in Proton Pencil Beam Dose Calculation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Penfold, S; Miller, A

2015-06-15

Purpose: Stoichiometric calibration of Hounsfield Units (HUs) for conversion to proton relative stopping powers (RStPs) is vital for accurate dose calculation in proton therapy. However proton dose distributions are not only dependent on RStP, but also on relative scattering power (RScP) of patient tissues. RScP is approximated from material density but a stoichiometric calibration of HU-density tables is commonly neglected. The purpose of this work was to quantify the difference in calculated dose of a commercial TPS when using HU-density tables based on tissue substitute materials and stoichiometric calibrated ICRU tissues. Methods: Two HU-density calibration tables were generated based onmore » scans of the CIRS electron density phantom. The first table was based directly on measured HU and manufacturer quoted density of tissue substitute materials. The second was based on the same CT scan of the CIRS phantom followed by a stoichiometric calibration of ICRU44 tissue materials. The research version of Pinnacle{sup 3} proton therapy was used to compute dose in a patient CT data set utilizing both HU-density tables. Results: The two HU-density tables showed significant differences for bone tissues; the difference increasing with increasing HU. Differences in density calibration table translated to a difference in calculated RScP of −2.5% for ICRU skeletal muscle and 9.2% for ICRU femur. Dose-volume histogram analysis of a parallel opposed proton therapy prostate plan showed that the difference in calculated dose was negligible when using the two different HU-density calibration tables. Conclusion: The impact of HU-density calibration technique on proton therapy dose calculation was assessed. While differences were found in the calculated RScP of bony tissues, the difference in dose distribution for realistic treatment scenarios was found to be insignificant.« less

Sandia National Laboratories: Research: Research Foundations

Science.gov Websites

Materials Science Nanodevices & Microsystems Radiation Effects & High Energy Density Science Science Geoscience Materials Science Nanodevices and Microsystems Radiation Effects and High Energy Nanodevices and Microsystems Radiation Effects and High Energy Density Science Exceptional service in the

Magnetocaloric Materials and the Optimization of Cooling Power Density

NASA Technical Reports Server (NTRS)

Wikus, Patrick; Canavan, Edgar; Heine, Sarah Trowbridge; Matsumoto, Koichi; Numazawa, Takenori

2014-01-01

The magnetocaloric effect is the thermal response of a material to an external magnetic field. This manuscript focuses on the physics and the properties of materials which are commonly used for magnetic refrigeration at cryogenic temperatures. After a brief overview of the magnetocaloric effect and associated thermodynamics, typical requirements on refrigerants are discussed from a standpoint of cooling power density optimization. Finally, a compilation of the most important properties of several common magnetocaloric materials is presented.

Thermal inertia and radar reflectivity of the Martian north polar ERG: Low-density aggregates

NASA Technical Reports Server (NTRS)

Herkenhoff, K. E.

1993-01-01

The north polar layered deposits on Mars appear to be the source of the dark material that comprises the north polar erg. The physical properties and chemical composition of the erg material therefore have important implications for the origin and evolution of the Martian layered deposits. Viking bistatic radar and infrared thermal mapping (IRTM) data indicate that the bulk density of the erg material is lower than that of the average Martian surface. These data are consistent with hypotheses involving formation of filamentary sublimation residue (FSR) particles from erosion of the layered deposits. The color and albedo of the erg and of the layered deposits, and the presence of magnetic material on Mars, suggest that the dark material is composed of low-density aggregates of magnetic dust grains, perhaps similar to FSR particles created in laboratory experiments.

Negative-pressure polymorphs made by heterostructural alloying.

PubMed

Siol, Sebastian; Holder, Aaron; Steffes, James; Schelhas, Laura T; Stone, Kevin H; Garten, Lauren; Perkins, John D; Parilla, Philip A; Toney, Michael F; Huey, Bryan D; Tumas, William; Lany, Stephan; Zakutayev, Andriy

2018-04-01

The ability of a material to adopt multiple structures, known as polymorphism, is a fascinating natural phenomenon. Various polymorphs with unusual properties are routinely synthesized by compression under positive pressure. However, changing a material's structure by applying tension under negative pressure is much more difficult. We show how negative-pressure polymorphs can be synthesized by mixing materials with different crystal structures-a general approach that should be applicable to many materials. Theoretical calculations suggest that it costs less energy to mix low-density structures than high-density structures, due to less competition for space between the atoms. Proof-of-concept experiments confirm that mixing two different high-density forms of MnSe and MnTe stabilizes a Mn(Se,Te) alloy with a low-density wurtzite structure. This Mn(Se,Te) negative-pressure polymorph has 2× to 4× lower electron effective mass compared to MnSe and MnTe parent compounds and has a piezoelectric response that none of the parent compounds have. This example shows how heterostructural alloying can lead to negative-pressure polymorphs with useful properties-materials that are otherwise nearly impossible to make.

Concrete density estimation by rebound hammer method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ismail, Mohamad Pauzi bin, E-mail: pauzi@nm.gov.my; Masenwat, Noor Azreen bin; Sani, Suhairy bin

Concrete is the most common and cheap material for radiation shielding. Compressive strength is the main parameter checked for determining concrete quality. However, for shielding purposes density is the parameter that needs to be considered. X- and -gamma radiations are effectively absorbed by a material with high atomic number and high density such as concrete. The high strength normally implies to higher density in concrete but this is not always true. This paper explains and discusses the correlation between rebound hammer testing and density for concrete containing hematite aggregates. A comparison is also made with normal concrete i.e. concrete containingmore » crushed granite.« less

Emergence of charge density waves and a pseudogap in single-layer TiTe2.

PubMed

Chen, P; Pai, Woei Wu; Chan, Y-H; Takayama, A; Xu, C-Z; Karn, A; Hasegawa, S; Chou, M Y; Mo, S-K; Fedorov, A-V; Chiang, T-C

2017-09-11

Two-dimensional materials constitute a promising platform for developing nanoscale devices and systems. Their physical properties can be very different from those of the corresponding three-dimensional materials because of extreme quantum confinement and dimensional reduction. Here we report a study of TiTe 2 from the single-layer to the bulk limit. Using angle-resolved photoemission spectroscopy and scanning tunneling microscopy and spectroscopy, we observed the emergence of a (2 × 2) charge density wave order in single-layer TiTe 2 with a transition temperature of 92 ± 3 K. Also observed was a pseudogap of about 28 meV at the Fermi level at 4.2 K. Surprisingly, no charge density wave transitions were observed in two-layer and multi-layer TiTe 2 , despite the quasi-two-dimensional nature of the material in the bulk. The unique charge density wave phenomenon in the single layer raises intriguing questions that challenge the prevailing thinking about the mechanisms of charge density wave formation.Due to reduced dimensionality, the properties of 2D materials are often different from their 3D counterparts. Here, the authors identify the emergence of a unique charge density wave (CDW) order in monolayer TiTe 2 that challenges the current understanding of CDW formation.

Towards novel organic high-Tc superconductors: Data mining using density of states similarity search

NASA Astrophysics Data System (ADS)

Geilhufe, R. Matthias; Borysov, Stanislav S.; Kalpakchi, Dmytro; Balatsky, Alexander V.

2018-02-01

Identifying novel functional materials with desired key properties is an important part of bridging the gap between fundamental research and technological advancement. In this context, high-throughput calculations combined with data-mining techniques highly accelerated this process in different areas of research during the past years. The strength of a data-driven approach for materials prediction lies in narrowing down the search space of thousands of materials to a subset of prospective candidates. Recently, the open-access organic materials database OMDB was released providing electronic structure data for thousands of previously synthesized three-dimensional organic crystals. Based on the OMDB, we report about the implementation of a novel density of states similarity search tool which is capable of retrieving materials with similar density of states to a reference material. The tool is based on the approximate nearest neighbor algorithm as implemented in the ANNOY library and can be applied via the OMDB web interface. The approach presented here is wide ranging and can be applied to various problems where the density of states is responsible for certain key properties of a material. As the first application, we report about materials exhibiting electronic structure similarities to the aromatic hydrocarbon p-terphenyl which was recently discussed as a potential organic high-temperature superconductor exhibiting a transition temperature in the order of 120 K under strong potassium doping. Although the mechanism driving the remarkable transition temperature remains under debate, we argue that the density of states, reflecting the electronic structure of a material, might serve as a crucial ingredient for the observed high Tc. To provide candidates which might exhibit comparable properties, we present 15 purely organic materials with similar features to p-terphenyl within the electronic structure, which also tend to have structural similarities with p-terphenyl such as space group symmetries, chemical composition, and molecular structure. The experimental verification of these candidates might lead to a better understanding of the underlying mechanism in case similar superconducting properties are revealed.

Interdimensional effects in systems with quasirelativistic fermions

NASA Astrophysics Data System (ADS)

Zulkoskey, A. C.; Dick, R.; Tanaka, K.

2017-07-01

We examine the Green function and the density of states for fermions moving in three-dimensional Dirac materials with interfaces which affect the propagation properties of particles. Motivation for our research comes from interest in materials that exhibit quasirelativistic dispersion relations. By modifying Dirac-type contributions to the Hamiltonian in an interface we are able to calculate the Green function and the density of states. The density of states inside the interface exhibits interpolating behavior between two and three dimensions, with two-dimensional behavior at high energies and three-dimensional behavior at low energies, provided that the shift in the mass parameter in the interface is small. We also discuss the impact of the interpolating density of states on optical absorption in Dirac materials with a two-dimensional substructure.

Chirality and orbital order in charge density waves

NASA Astrophysics Data System (ADS)

van Wezel, Jasper

2011-12-01

Helical arrangements of spins are common among magnetic materials. The first material to harbor a corkscrew pattern of charge density, on the other hand, was discovered only very recently. The nature of the order parameter is of key relevance, since rotating a magnetic vector around any propagation vector trivially yields a helical pattern. In contrast, the purely scalar charge density cannot straightforwardly support a chiral state. Here we use a Landau order parameter analysis to resolve this paradox, and show that the chiral charge order may be understood as a form of orbital ordering. We discuss the microscopic mechanism driving the transition and show it to be of a general form, thus allowing for a broad class of materials to display this novel type of orbital-ordered chiral charge density wave.

Detecting strain in birefringent materials using spectral polarimetry

NASA Technical Reports Server (NTRS)

Garner, Harold R. (Inventor); Ragucci, Anthony J. (Inventor); Cisar, Alan J. (Inventor); Huebschman, Michael L. (Inventor)

2010-01-01

A method, computer program product and system for analyzing multispectral images from a plurality of regions of birefringent material, such as a polymer film, using polarized light and a corresponding polar analyzer to identify differential strain in the birefringent material. For example, the birefringement material may be low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene, polyethylene terephthalate (PET), polyvinyl chloride (PVC), polyvinylidene chloride, polyester, nylon, or cellophane film. Optionally, the method includes generating a real-time quantitative strain map.

Antibacterial Drug Releasing Materials by Post-Polymerization Surface Modification

NASA Astrophysics Data System (ADS)

Chng, Shuyun; Moloney, Mark G.; Wu, Linda Y. L.

Functional materials are available by the post-polymerization surface modification of diverse polymers in a three-step process mediated, firstly, by carbene insertion chemistry, secondly, by diazonium coupling, and thirdly by modification with a remotely tethered spiropyran unit, and these materials may be used for the reversible binding and release of Penicillin V. Surface loading densities of up to 0.19mmol/g polymer are achievable, leading to materials with higher loading densities and release behavior relative to unmodified controls, and observable antibacterial biocidal activity.

Dual energy approach for cone beam artifacts correction

NASA Astrophysics Data System (ADS)

Han, Chulhee; Choi, Shinkook; Lee, Changwoo; Baek, Jongduk

2017-03-01

Cone beam computed tomography systems generate 3D volumetric images, which provide further morphological information compared to radiography and tomosynthesis systems. However, reconstructed images by FDK algorithm contain cone beam artifacts when a cone angle is large. To reduce the cone beam artifacts, two-pass algorithm has been proposed. The two-pass algorithm considers the cone beam artifacts are mainly caused by high density materials, and proposes an effective method to estimate error images (i.e., cone beam artifacts images) by the high density materials. While this approach is simple and effective with a small cone angle (i.e., 5 - 7 degree), the correction performance is degraded as the cone angle increases. In this work, we propose a new method to reduce the cone beam artifacts using a dual energy technique. The basic idea of the proposed method is to estimate the error images generated by the high density materials more reliably. To do this, projection data of the high density materials are extracted from dual energy CT projection data using a material decomposition technique, and then reconstructed by iterative reconstruction using total-variation regularization. The reconstructed high density materials are used to estimate the error images from the original FDK images. The performance of the proposed method is compared with the two-pass algorithm using root mean square errors. The results show that the proposed method reduces the cone beam artifacts more effectively, especially with a large cone angle.

A Class of Organopolysulfides As Liquid Cathode Materials for High-Energy-Density Lithium Batteries.

PubMed

Bhargav, Amruth; Bell, Michaela Elaine; Karty, Jonathan; Cui, Yi; Fu, Yongzhu

2018-06-27

Sulfur-based cathodes are promising to enable high-energy-density lithium-sulfur batteries; however, elemental sulfur as active material faces several challenges, including undesirable volume change (∼80%) when completely reduced and high dependence on liquid electrolyte wherein an electrolyte/sulfur ratio >10 μL mg -1 is required for high material utilization. These limit the attainable energy densities of these batteries. Herein, we introduce a new class of phenyl polysulfides C 6 H 5 S x C 6 H 5 (4 ≤ x ≤ 6) as liquid cathode materials synthesized in a facile and scalable route to mitigate these setbacks. These polysulfides possess sufficiently high theoretical specific capacities, specific energies, and energy densities. Spectroscopic techniques verify their chemical composition and computation shows that the volume change when reduced is about 37%. Lithium half-cell testing shows that phenyl hexasulfide (C 6 H 5 S 6 C 6 H 5 ) can provide a specific capacity of 650 mAh g -1 and capacity retention of 80% through 500 cycles at 1 C rate along with superlative performance up to 10 C. Furthermore, 1302 Wh kg -1 and 1720 Wh L -1 are achievable at a low electrolyte/active material ratio, i.e., 3 μL mg -1 . This work adds new members to the cathode family for Li-S batteries, reduces the gap between the theoretical and practical energy densities of batteries, and provides a new direction for the development of alternative high-capacity cathode materials.

Advanced Electrical Materials and Components Being Developed

NASA Technical Reports Server (NTRS)

Schwarze, Gene E.

2004-01-01

All aerospace systems require power management and distribution (PMAD) between the energy and power source and the loads. The PMAD subsystem can be broadly described as the conditioning and control of unregulated power from the energy source and its transmission to a power bus for distribution to the intended loads. All power and control circuits for PMAD require electrical components for switching, energy storage, voltage-to-current transformation, filtering, regulation, protection, and isolation. Advanced electrical materials and component development technology is a key technology to increasing the power density, efficiency, reliability, and operating temperature of the PMAD. The primary means to develop advanced electrical components is to develop new and/or significantly improved electronic materials for capacitors, magnetic components, and semiconductor switches and diodes. The next important step is to develop the processing techniques to fabricate electrical and electronic components that exceed the specifications of presently available state-of-the-art components. The NASA Glenn Research Center's advanced electrical materials and component development technology task is focused on the following three areas: 1) New and/or improved dielectric materials for the development of power capacitors with increased capacitance volumetric efficiency, energy density, and operating temperature; 2) New and/or improved high-frequency, high-temperature soft magnetic materials for the development of transformers and inductors with increased power density, energy density, electrical efficiency, and operating temperature; 3) Packaged high-temperature, high-power density, high-voltage, and low-loss SiC diodes and switches.

Microwave moisture sensing through use of a piecewise density-independent function

USDA-ARS?s Scientific Manuscript database

Microwave moisture sensing provides a means to determine nondestructively the amount of water in materials. This is accomplished through the correlation of dielectric properties with moisture in the material. In this study, linear relationships between a density-independent function of the dielectri...

Stiff, light, strong and ductile: nano-structured High Modulus Steel.

PubMed

Springer, H; Baron, C; Szczepaniak, A; Uhlenwinkel, V; Raabe, D

2017-06-05

Structural material development for lightweight applications aims at improving the key parameters strength, stiffness and ductility at low density, but these properties are typically mutually exclusive. Here we present how we overcome this trade-off with a new class of nano-structured steel - TiB 2 composites synthesised in-situ via bulk metallurgical spray-forming. Owing to the nano-sized dispersion of the TiB 2 particles of extreme stiffness and low density - obtained by the in-situ formation with rapid solidification kinetics - the new material has the mechanical performance of advanced high strength steels, and a 25% higher stiffness/density ratio than any of the currently used high strength steels, aluminium, magnesium and titanium alloys. This renders this High Modulus Steel the first density-reduced, high stiffness, high strength and yet ductile material which can be produced on an industrial scale. Also ideally suited for 3D printing technology, this material addresses all key requirements for high performance and cost effective lightweight design.

On the electron density localization in elemental cubic ceramic and FCC transition metals by means of a localized electrons detector.

PubMed

Aray, Yosslen; Paredes, Ricardo; Álvarez, Luis Javier; Martiz, Alejandro

2017-06-14

The electron density localization in insulator and semiconductor elemental cubic materials with diamond structure, carbon, silicon, germanium, and tin, and good metallic conductors with face centered cubic structure such as α-Co, Ni, Cu, Rh, Pd, Ag, Ir, Pt, and Au, was studied using a localized electrons detector defined in the local moment representation. Our results clearly show an opposite pattern of the electron density localization for the cubic ceramic and transition metal materials. It was found that, for the elemental ceramic materials, the zone of low electron localization is very small and is mainly localized on the atomic basin edges. On the contrary, for the transition metals, there are low-valued localized electrons detector isocontours defining a zone of highly delocalized electrons that extends throughout the material. We have found that the best conductors are those in which the electron density at this low-value zone is the lowest.

Decoupling the Effects of Mass Density and Hydrogen-, Oxygen-, and Aluminum-Based Defects on Optoelectronic Properties of Realistic Amorphous Alumina.

PubMed

Riffet, Vanessa; Vidal, Julien

2017-06-01

The search for functional materials is currently hindered by the difficulty to find significant correlation between constitutive properties of a material and its functional properties. In the case of amorphous materials, the diversity of local structures, chemical composition, impurities and mass densities makes such a connection difficult to be addressed. In this Letter, the relation between refractive index and composition has been investigated for amorphous AlO x materials, including nonstoichiometric AlO x , emphasizing the role of structural defects and the absence of effect of the band gap variation. It is found that the Newton-Drude (ND) relation predicts the refractive index from mass density with a rather high level of precision apart from some structures displaying structural defects. Our results show especially that O- and Al-based defects act as additive local disturbance in the vicinity of band gap, allowing us to decouple the mass density effects from defect effects (n = n[ND] + Δn defect ).

The density matrix method in photonic bandgap and antiferromagnetic materials

NASA Astrophysics Data System (ADS)

Barrie, Scott B.

In this thesis, a theory for dispersive polaritonic bandgap (DPBG) and photonic bandgap (PBG) materials is developed. An ensemble of multi-level nanoparticles, such as non-interacting two-, three- and four-level atoms doped in DPBG and PBG materials is considered. The optical properties of these materials such as spontaneous emission, line broadening, fluorescence and narrowing of the natural linewidth have been studied using the density matrix method. Numerical simulations for these properties have been performed for the DPBG materials SiC and InAs, and for a PBG material with a 20 percent gap-to-midgap ratio. When a three-level nanoparticle is doped into a DPBG material, it is predicted that one or two bound states exist when one or both resonance energies, respectively, lie in the bandgap. It is shown when a resonance energy lies below the bandgap, its spectral density peak weakens and broadens as the resonance energy increases to the lower band edge. For the first time it is predicted that when a nanoparticle's resonance energy lies above the bandgap, its spectral density peak weakens and broadens as the resonance energy increases. A relation is also found between spectral structure and gap-to-midgap ratios. The dressed states of a two-level atom doped into a DPBG material under the influence of an intense monochromatic laser field are examined. The splitting of the dressed state energies is calculated, and it is predicted that the splitting depends on the polariton density of states and the Rabi frequency of laser field. The fluoresence is also examined, and for the first time two distinct control processes are found for the transition from one peak to three peaks. It was previously known that the Rabi frequency controlled the Stark effect, but this thesis predicts that the local of the peak with respect to the optical bandgap can cause a transition from one to three peaks even with a weak Rabi frequency. The transient linewidth narrowing of PBG crystal emission peaks doped with four-level atoms is studied. It is found that linewidth narrowing is only dependent upon time delay when the resonance energy is not near a band edge. This is a new discovery. The density matrix method is employed to find the critical magnetic field at which spin flopping occurs in antiferromagnetic high temperature superconductors. It is found that this magnetic field depends upon the temperature, the anisotropy parameter and the doping concentration. Results are calculated for 1-2-3 HTSCs. Keywords. Quantum Optics, Density Matrix, Photonic Bandgap Materials, Dispersive Polaritonic Bandgap Materials, Antiferromagnets.

Effect of the target power density on high-power impulse magnetron sputtering of copper

NASA Astrophysics Data System (ADS)

Kozák, Tomáš

2012-04-01

We present a model analysis of high-power impulse magnetron sputtering of copper. We use a non-stationary global model based on the particle and energy conservation equations in two zones (the high density plasma ring above the target racetrack and the bulk plasma region), which makes it possible to calculate time evolutions of the averaged process gas and target material neutral and ion densities, as well as the fluxes of these particles to the target and substrate during a pulse period. We study the effect of the increasing target power density under conditions corresponding to a real experimental system. The calculated target current waveforms show a long steady state and are in good agreement with the experimental results. For an increasing target power density, an analysis of the particle densities shows a gradual transition to a metal dominated discharge plasma with an increasing degree of ionization of the depositing flux. The average fraction of target material ions in the total ion flux onto the substrate is more than 90% for average target power densities higher than 500 W cm-2 in a pulse. The average ionized fraction of target material atoms in the flux onto the substrate reaches 80% for a maximum average target power density of 3 kW cm-2 in a pulse.

Calcium intercalation into layered fluorinated sodium iron phosphate

DOE PAGES

Lipson, Albert L.; Kim, Soojeong; Pan, Baofei; ...

2017-10-09

Here, the energy density and cost of battery systems could be improved by moving to alternative battery chemistries such as Ca-ion. However, in order to switch chemistries many problems need to be solved including the identification of cathode materials with high energy density, and electrolytes that can plate and strip calcium metal. Herein, the feasibility and cycling performance of Ca 2+ intercalation into a desodiated layered Na 2FePO 4F host is described. This is the first demonstration of Ca 2+ intercalation into a polyanionic framework, which implies that other polyanionic framework materials may be active for Ca 2+ intercalation. Althoughmore » substantial effort is still needed to identify a high energy density cathode material, this study and others demonstrate the feasibility of Ca 2+ intercalation into multiple materials making it more probable that such a cathode material can be found.« less

Calcium intercalation into layered fluorinated sodium iron phosphate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lipson, Albert L.; Kim, Soojeong; Pan, Baofei

Here, the energy density and cost of battery systems could be improved by moving to alternative battery chemistries such as Ca-ion. However, in order to switch chemistries many problems need to be solved including the identification of cathode materials with high energy density, and electrolytes that can plate and strip calcium metal. Herein, the feasibility and cycling performance of Ca 2+ intercalation into a desodiated layered Na 2FePO 4F host is described. This is the first demonstration of Ca 2+ intercalation into a polyanionic framework, which implies that other polyanionic framework materials may be active for Ca 2+ intercalation. Althoughmore » substantial effort is still needed to identify a high energy density cathode material, this study and others demonstrate the feasibility of Ca 2+ intercalation into multiple materials making it more probable that such a cathode material can be found.« less

Understanding limiting factors in thick electrode performance as applied to high energy density Li-ion batteries

DOE PAGES

Du, Zhijia; Wood, David L.; Daniel, Claus; ...

2017-02-09

We present that increasing electrode thickness, thus increasing the volume ratio of active materials, is one effective method to enable the development of high energy density Li-ion batteries. In this study, an energy density versus power density optimization of LiNi 0.8Co 0.15Al 0.05O 2 (NCA)/graphite cell stack was conducted via mathematical modeling. The energy density was found to have a maximum point versus electrode thickness (critical thickness) at given discharging C rates. The physics-based factors that limit the energy/power density of thick electrodes were found to be increased cell polarization and underutilization of active materials. The latter is affected bymore » Li-ion diffusion in active materials and Li-ion depletion in the electrolyte phase. Based on those findings, possible approaches were derived to surmount the limiting factors. Finally, the improvement of the energy–power relationship in an 18,650 cell was used to demonstrate how to optimize the thick electrode parameters in cell engineering.« less

Density conversion factor determined using a cone-beam computed tomography unit NewTom QR-DVT 9000.

PubMed

Lagravère, M O; Fang, Y; Carey, J; Toogood, R W; Packota, G V; Major, P W

2006-11-01

The purpose of this study was to determine a conversion coefficient for Hounsfield Units (HU) to material density (g cm(-3)) obtained from cone-beam computed tomography (CBCT-NewTom QR-DVT 9000) data. Six cylindrical models of materials with different densities were made and scanned using the NewTom QR-DVT 9000 Volume Scanner. The raw data were converted into DICOM format and analysed using Merge eFilm and AMIRA to determine the HU of different areas of the models. There was no significant difference (P = 0.846) between the HU given by each piece of software. A linear regression was performed using the density, rho (g cm(-3)), as the dependent variable in terms of the HU (H). The regression equation obtained was rho = 0.002H-0.381 with an R2 value of 0.986. The standard error of the estimation is 27.104 HU in the case of the Hounsfield Units and 0.064 g cm(-3) in the case of density. CBCT provides an effective option for determination of material density expressed as Hounsfield Units.

Microwave sintering of nanophase ceramics without concomitant grain growth

DOEpatents

Eastman, Jeffrey A.; Sickafus, Kurt E.; Katz, Joel D.

1993-01-01

A method of sintering nanocrystalline material is disclosed wherein the nanocrystalline material is microwaved to heat the material to a temperature less than about 70% of the melting point of the nanocrystalline material expressed in degrees K. This method produces sintered nanocrystalline material having a density greater than about 95% of theoretical and an average grain size not more than about 3 times the average grain size of the nanocrystalline material before sintering. Rutile TiO.sub.2 as well as various other ceramics have been prepared. Grain growth of as little as 1.67 times has resulted with densities of about 90% of theoretical.

Development of a poly(dimethylacrylamide) based matrix material for solid phase high density peptide array synthesis employing a laser based material transfer

NASA Astrophysics Data System (ADS)

Ridder, Barbara; Foertsch, Tobias C.; Welle, Alexander; Mattes, Daniela S.; von Bojnicic-Kninski, Clemens M.; Loeffler, Felix F.; Nesterov-Mueller, Alexander; Meier, Michael A. R.; Breitling, Frank

2016-12-01

Poly(dimethylacrylamide) (PDMA) based matrix materials were developed for laser-based in situ solid phase peptide synthesis to produce high density arrays. In this specific array synthesis approach, amino acid derivatives are embedded into a matrix material, serving as a ;solid; solvent material at room temperature. Then, a laser pulse transfers this mixture to the target position on a synthesis slide, where the peptide array is synthesized. Upon heating above the glass transition temperature of the matrix material, it softens, allowing diffusion of the amino acid derivatives to the synthesis surface and serving as a solvent for peptide bond formation. Here, we synthesized PDMA six-arm star polymers, offering the desired matrix material properties, using atom transfer radical polymerization. With the synthesized polymers as matrix material, we structured and synthesized arrays with combinatorial laser transfer. With densities of up to 20,000 peptide spots per cm2, the resolution could be increased compared to the commercially available standard matrix material. Time-of-Flight Secondary Ion Mass Spectrometry experiments revealed the penetration behavior of an amino acid derivative into the prepared acceptor synthesis surface and the effectiveness of the washing protocols.

In Situ Neutron Diffraction Study of the Influence of Microstructure on the Mechanical Response of Additively Manufactured 304L Stainless Steel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, D. W.; Adams, D. P.; Balogh, L.

In situ neutron diffraction measurements were completed for this study during tensile and compressive deformation of stainless steel 304L additively manufactured (AM) using a high power directed energy deposition process. Traditionally produced wrought 304L material was also studied for comparison. The AM material exhibited roughly 200 MPa higher flow stress relative to the wrought material. Crystallite size, crystallographic texture, dislocation density, and lattice strains were all characterized to understand the differences in the macroscopic mechanical behavior. The AM material’s initial dislocation density was about 10 times that of the wrought material, and the flow strength of both materials obeyed themore » Taylor equation, indicating that the AM material’s increased yield strength was primarily due to greater dislocation density. Finally, a ~50 MPa flow strength tension/compression asymmetry was observed in the AM material, and several potential causes were examined.« less

Ab initio Computations of the Electronic, Mechanical, and Thermal Properties of Ultra High Temperature Ceramics (UHTC) ZrB2 and HfB2

NASA Technical Reports Server (NTRS)

Lawson, John W.; Bauschlicher, Charles W.; Daw, Murray

2011-01-01

Refractory materials such as metallic borides, often considered as ultra high temperature ceramics (UHTC), are characterized by high melting point, high hardness, and good chemical inertness. These materials have many applications which require high temperature materials that can operate with no or limited oxidation. Ab initio, first principles methods are the most accurate modeling approaches available and represent a parameter free description of the material based on the quantum mechanical equations. Using these methods, many of the intrinsic properties of these material can be obtained. We performed ab initio calculations based on density functional theory for the UHTC materials ZrB2 and HfB2. Computational results are presented for structural information (lattice constants, bond lengths, etc), electronic structure (bonding motifs, densities of states, band structure, etc), thermal quantities (phonon spectra, phonon densities of states, specific heat), as well as information about point defects such as vacancy and antisite formation energies.

In Situ Neutron Diffraction Study of the Influence of Microstructure on the Mechanical Response of Additively Manufactured 304L Stainless Steel

DOE PAGES

Brown, D. W.; Adams, D. P.; Balogh, L.; ...

2017-10-10

In situ neutron diffraction measurements were completed for this study during tensile and compressive deformation of stainless steel 304L additively manufactured (AM) using a high power directed energy deposition process. Traditionally produced wrought 304L material was also studied for comparison. The AM material exhibited roughly 200 MPa higher flow stress relative to the wrought material. Crystallite size, crystallographic texture, dislocation density, and lattice strains were all characterized to understand the differences in the macroscopic mechanical behavior. The AM material’s initial dislocation density was about 10 times that of the wrought material, and the flow strength of both materials obeyed themore » Taylor equation, indicating that the AM material’s increased yield strength was primarily due to greater dislocation density. Finally, a ~50 MPa flow strength tension/compression asymmetry was observed in the AM material, and several potential causes were examined.« less

Development of a 3D muon disappearance algorithm for muon scattering tomography

NASA Astrophysics Data System (ADS)

Blackwell, T. B.; Kudryavtsev, V. A.

2015-05-01

Upon passing through a material, muons lose energy, scatter off nuclei and atomic electrons, and can stop in the material. Muons will more readily lose energy in higher density materials. Therefore multiple muon disappearances within a localized volume may signal the presence of high-density materials. We have developed a new technique that improves the sensitivity of standard muon scattering tomography. This technique exploits these muon disappearances to perform non-destructive assay of an inspected volume. Muons that disappear have their track evaluated using a 3D line extrapolation algorithm, which is in turn used to construct a 3D tomographic image of the inspected volume. Results of Monte Carlo simulations that measure muon disappearance in different types of target materials are presented. The ability to differentiate between different density materials using the 3D line extrapolation algorithm is established. Finally the capability of this new muon disappearance technique to enhance muon scattering tomography techniques in detecting shielded HEU in cargo containers has been demonstrated.

Fullerene-based low-density superhard materials with tunable bandgaps

NASA Astrophysics Data System (ADS)

Cao, Ai-Hua; Zhao, Wen-Juan; Gan, Li-Hua

2018-06-01

Four carbon allotropes built from tetrahedral symmetrical fullerenes C28 and C40 are predicted to be superhard materials with mass density around that of water, and all of them are porous semiconductors. Both the bandgaps and hardness decrease with increasing ratio of sp2 hybridized carbon atoms. The mechanical and thermodynamic stabilities of C28- and C40-based allotropes at zero pressure are confirmed by a variety of state-of-the-art theoretical calculations. The evolution trend of bandgap found here suggests that one can obtain low-density hard materials with tunable bandgaps by substituting the carbon atom in diamond with different Td-symmetrical non-IPR fullerene Cn.

Robust determination of mass attenuation coefficients of materials with unknown thickness and density

NASA Astrophysics Data System (ADS)

Kurudirek, M.; Medhat, M. E.

2014-07-01

An alternative approach is used to measure normalized mass attenuation coefficients (μ/ρ) of materials with unknown thickness and density. The adopted procedure is based on the use of simultaneous emission of Kα and Kβ X-ray lines as well as gamma peaks from radioactive sources in transmission geometry. 109Cd and 60Co radioactive sources were used for the purpose of the investigation. It has been observed that using the simultaneous X- and/or gamma rays of different energy allows accurate determination of relative mass attenuation coefficients by eliminating the dependence of μ/ρ on thickness and density of the material.

Orbiter thermal pressure drop characteristics for shuttle orbiter thermal protection system components: High density tile, low density tile, densified low density tile, and strain isolation pad

NASA Technical Reports Server (NTRS)

Lawing, P. L.; Nystrom, D. M.

1980-01-01

Pressure drop tests were conducted on available samples of low and high density tile, densified low density tile, and strain isolation pads. The results are presented in terms of pressure drop, material thickness and volume flow rate. Although the test apparatus was only capable of a small part of the range of conditions to be encountered in a Shuttle Orbiter flight, the data serve to determine the type of flow characteristics to be expected for each material type tested; the measured quantities also should serve as input for initial venting and flow through analysis.

Thermoelectric power as a probe of density of states in correlated actinide materials: The case of PuCoGa 5 superconductor

DOE PAGES

Gofryk, K.; Griveau, J. -C.; Riseborough, P. S.; ...

2016-11-09

We present measurements of the thermoelectric power of the plutonium-based unconventional superconductor PuCoGa 5. The data is interpreted within a phenomenological model for the quasiparticle density of states of intermediate valence systems and the results are compared with results obtained from photoemission spectroscopy. The results are consistent with intermediate valence nature of 5f-electrons, furthermore, we propose that measurements of the Seebeck coefficient can be used as a probe of density of states in this material, thereby providing a link between transport measurements and photoemission in strongly correlated materials. Here, we discuss these results and their implications for the electronic structuremore » determination of other strongly correlated systems, especially nuclear materials.« less

Nonaqueous lithium-ion capacitors with high energy densities using trigol-reduced graphene oxide nanosheets as cathode-active material.

PubMed

Aravindan, Vanchiappan; Mhamane, Dattakumar; Ling, Wong Chui; Ogale, Satishchandra; Madhavi, Srinivasan

2013-12-01

One HEC of a material: The use of trigol-reduced graphene oxide nanosheets as cathode material in hybrid lithium-ion electrochemical capacitors (Li-HECs) results in an energy density of 45 Wh kg(-1) ; much enhanced when compared to similar devices. The mass loading of the active materials is optimized, and the devices show good cycling performance. Li-HECs employing these materials outperform other supercapacitors, making them attractive for use in power sources. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The effect of adsorbed liquid and material density on saltation threshold: Insight from laboratory and wind tunnel experiments

NASA Astrophysics Data System (ADS)

Yu, Xinting; Hörst, Sarah M.; He, Chao; Bridges, Nathan T.; Burr, Devon M.; Sebree, Joshua A.; Smith, James K.

2017-11-01

Saltation threshold, the minimum wind speed for sediment transport, is a fundamental parameter in aeolian processes. Measuring this threshold using boundary layer wind tunnels, in which particles are mobilized by flowing air, for a subset of different planetary conditions can inform our understanding of physical processes of sediment transport. The presence of liquid, such as water on Earth or methane on Titan, may affect the threshold values to a great extent. Sediment density is also crucial for determining threshold values. Here we provide quantitative data on density and water content of common wind tunnel materials (including chromite, basalt, quartz sand, beach sand, glass beads, gas chromatograph packing materials, walnut shells, iced tea powder, activated charcoal, instant coffee, and glass bubbles) that have been used to study conditions on Earth, Titan, Mars, and Venus. The measured density values for low density materials are higher compared to literature values (e.g., ∼30% for walnut shells), whereas for the high density materials, there is no such discrepancy. We also find that low density materials have much higher water content and longer atmospheric equilibration timescales compared to high density sediments. We used thermogravimetric analysis (TGA) to quantify surface and internal water and found that over 80% of the total water content is surface water for low density materials. In the Titan Wind Tunnel (TWT), where Reynolds number conditions similar to those on Titan can be achieved, we performed threshold experiments with the standard walnut shells (125-150 μm, 7.2% water by mass) and dried walnut shells, in which the water content was reduced to 1.7%. The threshold results for the two scenarios are almost the same, which indicates that humidity had a negligible effect on threshold for walnut shells in this experimental regime. When the water content is lower than 11.0%, the interparticle forces are dominated by adsorption forces, whereas at higher values the interparticle forces are dominated by much larger capillary forces. For materials with low equilibrium water content, like quartz sand, capillary forces dominate. When the interparticle forces are dominated by adsorption forces, the threshold does not increase with increasing relative humidity (RH) or water content. Only when the interparticle forces are dominated by capillary forces does the threshold start to increase with increasing RH/water content. Since tholins have a low methane content (0.3% at saturation, [Curtis, D. B., Hatch, C. D., Hasenkopf, C. A., et al., 2008. Laboratory studies of methane and ethane adsorption and nucleation onto organic particles: Application to Titan's clouds. Icarus, 195, 792. http://dx.doi.org/10.1016/j.icarus.2008.02.003]), we believe tholins would behave similarly to quartz sand when subjected to methane moisture.

Measuring the Density of Different Materials by Using the Collimated Fast Neutron Beam

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sudac, D.; Nad, K.; Orlic, Z.

It was demonstrated in the previous work that various threat materials could be detected inside the sea going cargo container by measuring the three variables, carbon and oxygen concentration and density of investigated material. Density was determined by measuring transmitted neutrons, which is not always practical in terms of setting up the instrument geometry. In order to enable more geometry flexibility, we have investigated the possibility of using the scattered neutrons in cargo material identification. For that purpose, the densities of different materials were measured depending on the position of neutron detectors and neutron generator with respect to the targetmore » position. One neutron detector was put above the target, one behind and one in front of the target, above the neutron generator. It was shown that all three positions of neutron detectors can be successfully used to measure the target density, but only if the detected neutrons are successfully discriminated from the gamma rays. Although the associated alpha particle technique/associate particle imaging (API) was used to discriminate the neutrons from the gamma rays, it is believed that the same results would be obtained by using the pulse shape discrimination method. In that way API technique can be avoided and the neutron generator which produces much higher beam intensity than 10{sup 8} n/s can be used. (authors)« less

Edge Stabilized Ribbon (ESR); Stress, Dislocation Density and Electronic Performance

NASA Technical Reports Server (NTRS)

Sachs, E. M.

1984-01-01

The edge stabilized ribbon (ESR) silicon ribbon was grown in widths of 1, 2.2 and 4.0 inches at speeds ranging from .6 to 7 in/min, which result in ribbon thicknesses of 5 to 400 microns. One of the primary problems remaining in ESR growth is that of thermally induced mechanical stresses. This problem is manifested as ribbon with a high degree of residual stress or as ribbon with buckled ribbon. Thermal stresses result in a high dislocation density in the grown material, resulting in compromised electronic performance. Improvements in ribbon flatness were accomplished by modification of the ribbon cooling profile. Ribbon flatness and other experimental observations of ESR ribbon are discussed. Laser scanner measurements show a good correlation between diffusion length and dislocation density which indicates that the high dislocation densities are the primary cause of the poor current performance of ESR materials. Dislocation densities were reduced and improved electronic performance resulted. Laser scanner data on new and old material are presented.

Nanostructured Electrode Materials Derived from Metal-Organic Framework Xerogels for High-Energy-Density Asymmetric Supercapacitor.

PubMed

Mahmood, Asif; Zou, Ruqiang; Wang, Qingfei; Xia, Wei; Tabassum, Hassina; Qiu, Bin; Zhao, Ruo

2016-01-27

This work successfully demonstrates metal-organic framework (MOF) derived strategy to prepare nanoporous carbon (NPC) with or without Fe3O4/Fe nanoparticles by the optimization of calcination temperature as highly active electrode materials for asymmetric supercapacitors (ASC). The nanostructured Fe3O4/Fe/C hybrid shows high specific capacitance of 600 F/g at a current density of 1 A/g and excellent capacitance retention up to 500 F/g at 8 A/g. Furthermore, hierarchically NPC with high surface area also obtained from MOF gels displays excellent electrochemical performance of 272 F/g at 2 mV/s. Considering practical applications, aqueous ASC (aASC) was also assembled, which shows high energy density of 17.496 Wh/kg at the power density of 388.8 W/kg. The high energy density and excellent capacity retention of the developed materials show great promise for the practical utilization of these energy storage devices.

Ultra low density biodegradable shape memory polymer foams with tunable physical properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singhal, Pooja; Wilson, Thomas S.; Cosgriff-Hernandez, Elizabeth

Compositions and/or structures of degradable shape memory polymers (SMPs) ranging in form from neat/unfoamed to ultra low density materials of down to 0.005 g/cc density. These materials show controllable degradation rate, actuation temperature and breadth of transitions along with high modulus and excellent shape memory behavior. A method of m ly low density foams (up to 0.005 g/cc) via use of combined chemical and physical aking extreme blowing agents, where the physical blowing agents may be a single compound or mixtures of two or more compounds, and other related methods, including of using multiple co-blowing agents of successively higher boilingmore » points in order to achieve a large range of densities for a fixed net chemical composition. Methods of optimization of the physical properties of the foams such as porosity, cell size and distribution, cell openness etc. of these materials, to further expand their uses and improve their performance.« less

Assessing Density Functionals Using Many Body Theory for Hybrid Perovskites

NASA Astrophysics Data System (ADS)

Bokdam, Menno; Lahnsteiner, Jonathan; Ramberger, Benjamin; Schäfer, Tobias; Kresse, Georg

2017-10-01

Which density functional is the "best" for structure simulations of a particular material? A concise, first principles, approach to answer this question is presented. The random phase approximation (RPA)—an accurate many body theory—is used to evaluate various density functionals. To demonstrate and verify the method, we apply it to the hybrid perovskite MAPbI3 , a promising new solar cell material. The evaluation is done by first creating finite temperature ensembles for small supercells using RPA molecular dynamics, and then evaluating the variance between the RPA and various approximate density functionals for these ensembles. We find that, contrary to recent suggestions, van der Waals functionals do not improve the description of the material, whereas hybrid functionals and the strongly constrained appropriately normed (SCAN) density functional yield very good agreement with the RPA. Finally, our study shows that in the room temperature tetragonal phase of MAPbI3 , the molecules are preferentially parallel to the shorter lattice vectors but reorientation on ps time scales is still possible.

Supercapacitors based on 3D network of activated carbon nanowhiskers wrapped-on graphitized electrospun nanofibers

NASA Astrophysics Data System (ADS)

He, Shuijian; Chen, Linlin; Xie, Chencheng; Hu, Huan; Chen, Shuiliang; Hanif, Muddasir; Hou, Haoqing

2013-12-01

Due to their cycling stability and high power density, the supercapacitors bridge the power/energy gap between traditional dielectric capacitors and batteries/fuel cells. Electrode materials are key components for making high performance supercapacitors. An activated carbon nanowhiskers (ACNWs) wrapped-on graphitized electrospun nanofiber (GENF) network (ACNWs/GENFN) with 3D porous structure is prepared as a new type of binder-free electrode material for supercapacitors. The supercapacitor based on the ACNWs/GENFN composite material displays an excellent performance with a specific capacitance of 176.5 F g-1 at current density of 0.5 A g-1, an ultrahigh power density of 252.8 kW kg-1 at current density of 800 A g-1 and an outstanding cycling stability of no capacitance loss after 10,000 charge/discharge cycles.

Anti-Ferroelectric Ceramics for High Energy Density Capacitors.

PubMed

Chauhan, Aditya; Patel, Satyanarayan; Vaish, Rahul; Bowen, Chris R

2015-11-25

With an ever increasing dependence on electrical energy for powering modern equipment and electronics, research is focused on the development of efficient methods for the generation, storage and distribution of electrical power. In this regard, the development of suitable dielectric based solid-state capacitors will play a key role in revolutionizing modern day electronic and electrical devices. Among the popular dielectric materials, anti-ferroelectrics (AFE) display evidence of being a strong contender for future ceramic capacitors. AFE materials possess low dielectric loss, low coercive field, low remnant polarization, high energy density, high material efficiency, and fast discharge rates; all of these characteristics makes AFE materials a lucrative research direction. However, despite the evident advantages, there have only been limited attempts to develop this area. This article attempts to provide a focus to this area by presenting a timely review on the topic, on the relevant scientific advancements that have been made with respect to utilization and development of anti-ferroelectric materials for electric energy storage applications. The article begins with a general introduction discussing the need for high energy density capacitors, the present solutions being used to address this problem, and a brief discussion of various advantages of anti-ferroelectric materials for high energy storage applications. This is followed by a general description of anti-ferroelectricity and important anti-ferroelectric materials. The remainder of the paper is divided into two subsections, the first of which presents various physical routes for enhancing the energy storage density while the latter section describes chemical routes for enhanced storage density. This is followed by conclusions and future prospects and challenges which need to be addressed in this particular field.

Anti-Ferroelectric Ceramics for High Energy Density Capacitors

PubMed Central

Chauhan, Aditya; Patel, Satyanarayan; Vaish, Rahul; Bowen, Chris R.

2015-01-01

With an ever increasing dependence on electrical energy for powering modern equipment and electronics, research is focused on the development of efficient methods for the generation, storage and distribution of electrical power. In this regard, the development of suitable dielectric based solid-state capacitors will play a key role in revolutionizing modern day electronic and electrical devices. Among the popular dielectric materials, anti-ferroelectrics (AFE) display evidence of being a strong contender for future ceramic capacitors. AFE materials possess low dielectric loss, low coercive field, low remnant polarization, high energy density, high material efficiency, and fast discharge rates; all of these characteristics makes AFE materials a lucrative research direction. However, despite the evident advantages, there have only been limited attempts to develop this area. This article attempts to provide a focus to this area by presenting a timely review on the topic, on the relevant scientific advancements that have been made with respect to utilization and development of anti-ferroelectric materials for electric energy storage applications. The article begins with a general introduction discussing the need for high energy density capacitors, the present solutions being used to address this problem, and a brief discussion of various advantages of anti-ferroelectric materials for high energy storage applications. This is followed by a general description of anti-ferroelectricity and important anti-ferroelectric materials. The remainder of the paper is divided into two subsections, the first of which presents various physical routes for enhancing the energy storage density while the latter section describes chemical routes for enhanced storage density. This is followed by conclusions and future prospects and challenges which need to be addressed in this particular field. PMID:28793694

Measurement of the Electron Density and the Attachment Rate Coefficient in Silane/Helium Discharges.

DTIC Science & Technology

1986-09-01

materials -- in this case hydrogenated amorphous silicon . One of the biggest problems in such a task is the fact that the discharge creates complex radicals...electron density is enhanced -- even on a time-averaged basis, and the silicon deposition rate is also increased. The physical process for the density...etching and deposition of semiconductor materials. Plasma etching (also known as dry etching) Of silicon using flourine bearing gases has made it possible

Experimental study of the maximum resolution and packing density achievable in sintered and non-sintered binder-jet 3D printed steel microchannels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elliott, Amy M; Mehdizadeh Momen, Ayyoub; Benedict, Michael

2015-01-01

Developing high resolution 3D printed metallic microchannels is a challenge especially when there is an essential need for high packing density of the primary material. While high packing density could be achieved by heating the structure to the sintering temperature, some heat sensitive applications require other strategies to improve the packing density of primary materials. In this study the goal is to develop high green or pack densities microchannels on the scale of 2-300 microns which have a robust mechanical structure. Binder-jet 3D printing is an additive manufacturing process in which droplets of binder are deposited via inkjet into amore » bed of powder. By repeatedly spreading thin layers of powder and depositing binder into the appropriate 2D profiles, complex 3D objects can be created one layer at time. Microchannels with features on the order of 500 microns were fabricated via binder jetting of steel powder and then sintered and/or infiltrated with a secondary material. The average particle size of the steel powder was varied along with the droplet volume of the inkjet-deposited binder. The resolution of the process, packing density of the primary material, the subsequent features sizes of the microchannels, and the overall microchannel quality were characterized as a function of particle size distribution, droplet sizes and heat treatment temperatures.« less

Application of High-Density Electropulsing to Improve the Performance of Metallic Materials: Mechanisms, Microstructure and Properties

PubMed Central

Sheng, Yinying; Hua, Youlu; Zhao, Xueyang; Chen, Lianxi; Zhou, Hanyu; Wang, James; Berndt, Christopher C.; Li, Wei

2018-01-01

The technology of high-density electropulsing has been applied to increase the performance of metallic materials since the 1990s and has shown significant advantages over traditional heat treatment in many aspects. However, the microstructure changes in electropulsing treatment (EPT) metals and alloys have not been fully explored, and the effects vary significantly on different material. When high-density electrical pulses are applied to metals and alloys, the input of electric energy and thermal energy generally leads to structural rearrangements, such as dynamic recrystallization, dislocation movements and grain refinement. The enhanced mechanical properties of the metals and alloys after high-density electropulsing treatment are reflected by the significant improvement of elongation. As a result, this technology holds great promise in improving the deformation limit and repairing cracks and defects in the plastic processing of metals. This review summarizes the effect of high-density electropulsing treatment on microstructural properties and, thus, the enhancement in mechanical strength, hardness and corrosion performance of metallic materials. It is noteworthy that the change of some properties can be related to the structure state before EPT (quenched, annealed, deformed or others). The mechanisms for the microstructural evolution, grain refinement and formation of oriented microstructures of different metals and alloys are presented. Future research trends of high-density electrical pulse technology for specific metals and alloys are highlighted. PMID:29364844

Nanoscale measurement of Nernst effect in two-dimensional charge density wave material 1T-TaS 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Stephen M.; Luican-Mayer, Adina; Bhattacharya, Anand

Advances in nanoscale material characterization on two-dimensional van der Waals layered materials primarily involve their optical and electronic properties. The thermal properties of these materials are harder to access due to the difficulty of thermal measurements at the nanoscale. In this work, we create a nanoscale magnetothermal device platform to access the basic out-of-plane magnetothermal transport properties of ultrathin van der Waals materials. Specifically, the Nernst effect in the charge density wave transition metal dichalcogenide 1T-TaS 2 is examined on nano-thin flakes in a patterned device structure. It is revealed that near the commensurate charge density wave (CCDW) to nearlymore » commensurate charge density wave (NCCDW) phase transition, the polarity of the Nernst effect changes. Since the Nernst effect is especially sensitive to changes in the Fermi surface, this suggests that large changes are occurring in the out-of-plane electronic structure of 1T-TaS 2, which are otherwise unresolved in just in-plane electronic transport measurements. This may signal a coherent evolution of out-of-plane stacking in the CCDW! NCCDW transition.« less

Negative-pressure polymorphs made by heterostructural alloying

DOE Office of Scientific and Technical Information (OSTI.GOV)

Siol, Sebastian; Holder, Aaron; Steffes, James

The ability of a material to adopt multiple structures, known as polymorphism, is a fascinating natural phenomenon. Various polymorphs with unusual properties are routinely synthesized by compression under positive pressure. However, changing a material's structure by applying tension under negative pressure is much more difficult. We show how negative-pressure polymorphs can be synthesized by mixing materials with different crystal structures - a general approach that should be applicable to many materials. Theoretical calculations suggest that it costs less energy to mix low-density structures than high-density structures, due to less competition for space between the atoms. Proof-of-concept experiments confirm that mixingmore » two different high-density forms of MnSe and MnTe stabilizes a Mn(Se,Te) alloy with a low-density wurtzite structure. This Mn(Se,Te) negative-pressure polymorph has 2x to 4x lower electron effective mass compared to MnSe and MnTe parent compounds and has a piezoelectric response that none of the parent compounds have. Lastly, this example shows how heterostructural alloying can lead to negative-pressure polymorphs with useful properties - materials that are otherwise nearly impossible to make.« less

Pulse Power Capability Of High Energy Density Capacitors Based on a New Dielectric Material

NASA Technical Reports Server (NTRS)

Winsor, Paul; Scholz, Tim; Hudis, Martin; Slenes, Kirk M.

1999-01-01

A new dielectric composite consisting of a polymer coated onto a high-density metallized Kraft has been developed for application in high energy density pulse power capacitors. The polymer coating is custom formulated for high dielectric constant and strength with minimum dielectric losses. The composite can be wound and processed using conventional wound film capacitor manufacturing equipment. This new system has the potential to achieve 2 to 3 J/cu cm whole capacitor energy density at voltage levels above 3.0 kV, and can maintain its mechanical properties to temperatures above 150 C. The technical and manufacturing development of the composite material and fabrication into capacitors are summarized in this paper. Energy discharge testing, including capacitance and charge-discharge efficiency at normal and elevated temperatures, as well as DC life testing were performed on capacitors manufactured using this material. TPL (Albuquerque, NM) has developed the material and Aerovox (New Bedford, MA) has used the material to build and test actual capacitors. The results of the testing will focus on pulse power applications specifically those found in electro-magnetic armor and guns, high power microwave sources and defibrillators.

Negative-pressure polymorphs made by heterostructural alloying

DOE PAGES

Siol, Sebastian; Holder, Aaron; Steffes, James; ...

2018-04-20

The ability of a material to adopt multiple structures, known as polymorphism, is a fascinating natural phenomenon. Various polymorphs with unusual properties are routinely synthesized by compression under positive pressure. However, changing a material's structure by applying tension under negative pressure is much more difficult. We show how negative-pressure polymorphs can be synthesized by mixing materials with different crystal structures - a general approach that should be applicable to many materials. Theoretical calculations suggest that it costs less energy to mix low-density structures than high-density structures, due to less competition for space between the atoms. Proof-of-concept experiments confirm that mixingmore » two different high-density forms of MnSe and MnTe stabilizes a Mn(Se,Te) alloy with a low-density wurtzite structure. This Mn(Se,Te) negative-pressure polymorph has 2x to 4x lower electron effective mass compared to MnSe and MnTe parent compounds and has a piezoelectric response that none of the parent compounds have. Lastly, this example shows how heterostructural alloying can lead to negative-pressure polymorphs with useful properties - materials that are otherwise nearly impossible to make.« less

The mechanics and design of a lightweight three-dimensional graphene assembly

PubMed Central

Qin, Zhao; Jung, Gang Seob; Kang, Min Jeong; Buehler, Markus J.

2017-01-01

Recent advances in three-dimensional (3D) graphene assembly have shown how we can make solid porous materials that are lighter than air. It is plausible that these solid materials can be mechanically strong enough for applications under extreme conditions, such as being a substitute for helium in filling up an unpowered flight balloon. However, knowledge of the elastic modulus and strength of the porous graphene assembly as functions of its structure has not been available, preventing evaluation of its feasibility. We combine bottom-up computational modeling with experiments based on 3D-printed models to investigate the mechanics of porous 3D graphene materials, resulting in new designs of carbon materials. Our study reveals that although the 3D graphene assembly has an exceptionally high strength at relatively high density (given the fact that it has a density of 4.6% that of mild steel and is 10 times as strong as mild steel), its mechanical properties decrease with density much faster than those of polymer foams. Our results provide critical densities below which the 3D graphene assembly starts to lose its mechanical advantage over most polymeric cellular materials. PMID:28070559

The effect of activation agent on surface morphology, density and porosity of palm shell and coconut shell activated carbon

NASA Astrophysics Data System (ADS)

Leman, A. M.; Zakaria, S.; Salleh, M. N. M.; Sunar, N. M.; Feriyanto, D.; Nazri, A. A.

2017-09-01

Activated carbon (AC) has one of the promising alternative technology for filtration and adsorption process. It inexpensive material because the sources is abundant especially in Malaysia. Main purpose of this project is to develop AC by chemical activation process to improve adsorption capacity by improving porosity of AC. AC developed via carbonization using designed burner at temperature of 650°C to 850 °C and activated by Potassium Hydroxide (KOH) in 12 hour and then dried at temperature of 300°C. Characterization and analysis is conducted by Scanning Electron Microscopy (SEM) for surface morphology analysis, Energy Dispersive Spectroscopy (EDS) for composition analysis, density and porosity analysis. Results shows that uneven surface has been observed both of AC and non-AC and also AC shows higher porosity as compared to non-AC materials. Density value of raw material has lower than AC up to 11.67% and 47.54% and porosity of raw material has higher than AC up to 31.45% and 45.69% for palm shell and coconut shell AC. It can be concluded that lower density represent higher porosity of material and higher porosity indicated higher adsorption capacity as well.

Quantification of micro stickies

Treesearch

Mahendra Doshi; Jeffrey Dyer; Salman Aziz; Kristine Jackson; Said M. Abubakr

1997-01-01

The objective of this project was to compare the different methods for the quantification of micro stickies. The hydrophobic materials investigated in this project for the collection of micro stickies were Microfoam* (polypropylene packing material), low density polyethylene film (LDPE), high density polyethylene (HDPE; a flat piece from a square plastic bottle), paper...

High Density Polymer-Based Integrated Electgrode Array

DOEpatents

Maghribi, Mariam N.; Krulevitch, Peter A.; Davidson, James Courtney; Hamilton, Julie K.

2006-04-25

A high density polymer-based integrated electrode apparatus that comprises a central electrode body and a multiplicity of arms extending from the electrode body. The central electrode body and the multiplicity of arms are comprised of a silicone material with metal features in said silicone material that comprise electronic circuits.

Density scaling of phantom materials for a 3D dose verification system.

PubMed

Tani, Kensuke; Fujita, Yukio; Wakita, Akihisa; Miyasaka, Ryohei; Uehara, Ryuzo; Kodama, Takumi; Suzuki, Yuya; Aikawa, Ako; Mizuno, Norifumi; Kawamori, Jiro; Saitoh, Hidetoshi

2018-05-21

In this study, the optimum density scaling factors of phantom materials for a commercially available three-dimensional (3D) dose verification system (Delta4) were investigated in order to improve the accuracy of the calculated dose distributions in the phantom materials. At field sizes of 10 × 10 and 5 × 5 cm 2 with the same geometry, tissue-phantom ratios (TPRs) in water, polymethyl methacrylate (PMMA), and Plastic Water Diagnostic Therapy (PWDT) were measured, and TPRs in various density scaling factors of water were calculated by Monte Carlo simulation, Adaptive Convolve (AdC, Pinnacle 3 ), Collapsed Cone Convolution (CCC, RayStation), and AcurosXB (AXB, Eclipse). Effective linear attenuation coefficients (μ eff ) were obtained from the TPRs. The ratios of μ eff in phantom and water ((μ eff ) pl,water ) were compared between the measurements and calculations. For each phantom material, the density scaling factor proposed in this study (DSF) was set to be the value providing a match between the calculated and measured (μ eff ) pl,water . The optimum density scaling factor was verified through the comparison of the dose distributions measured by Delta4 and calculated with three different density scaling factors: the nominal physical density (PD), nominal relative electron density (ED), and DSF. Three plans were used for the verifications: a static field of 10 × 10 cm 2 and two intensity modulated radiation therapy (IMRT) treatment plans. DSF were determined to be 1.13 for PMMA and 0.98 for PWDT. DSF for PMMA showed good agreement for AdC and CCC with 6 MV x ray, and AdC for 10 MV x ray. DSF for PWDT showed good agreement regardless of the dose calculation algorithms and x-ray energy. DSF can be considered one of the references for the density scaling factor of Delta4 phantom materials and may help improve the accuracy of the IMRT dose verification using Delta4. © 2018 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

High Energy Density Li-ion Cells for EV’s Based on Novel, High Voltage Cathode Material Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kepler, Keith D.; Slater, Michael

This Li-ion cell technology development project had three objectives: to develop advanced electrode materials and cell components to enable stable high-voltage operation; to design and demonstrate a Li-ion cell using these materials that meets the PHEV40 performance targets; and to design and demonstrate a Li-ion cell using these materials that meets the EV performance targets. The major challenge to creating stable high energy cells with long cycle life is system integration. Although materials that can give high energy cells are known, stabilizing them towards long-term cycling in the presence of other novel cell components is a major challenge. The majormore » technical barriers addressed by this work include low cathode specific energy, poor electrolyte stability during high voltage operation, and insufficient capacity retention during deep discharge for Si-containing anodes. Through the course of this project, Farasis was able to improve capacity retention of NCM materials for 4.4+ V operation, through both surface treatment and bulk-doping approaches. Other material advances include increased rate capability and of HE-NCM materials through novel synthesis approach, doubling the relative capacity at 1C over materials synthesized using standard methods. Silicon active materials proved challenging throughout the project and ultimately were the limiting factor in the energy density vs. cycle life trade off. By avoiding silicon anodes for the lower energy PHEV design, we manufactured cells with intermediate energy density and long cycle life under high voltage operation for PHEV applications. Cells with high energy density for EV applications were manufactured targeting a 300 Wh/kg design and were able to achieve > 200 cycles.« less

Reformulated space-charge-limited current model and its application to disordered organic systems

NASA Astrophysics Data System (ADS)

Woellner, Cristiano F.; Freire, José A.

2011-02-01

We have reformulated a traditional model used to describe the current-voltage dependence of low mobility materials sandwiched between planar electrodes by using the quasi-electrochemical potential as the fundamental variable instead of the local electric field or the local charge carrier density. This allows the material density-of-states to enter explicitly in the equations and dispenses with the need to assume a particular type of contact. The diffusion current is included and as a consequence the current-voltage dependence obtained covers, with increasing bias, the diffusion limited current, the space-charge limited current, and the injection limited current regimes. The generalized Einstein relation and the field and density dependent mobility are naturally incorporated into the formalism; these two points being of particular relevance for disordered organic semiconductors. The reformulated model can be applied to any material where the carrier density and the mobility may be written as a function of the quasi-electrochemical potential. We applied it to the textbook example of a nondegenerate, constant mobility material and showed how a single dimensionless parameter determines the form of the I(V) curve. We obtained integral expressions for the carrier density and for the mobility as a function of the quasi-electrochemical potential for a Gaussianly disordered organic material and found the general form of the I(V) curve for such materials over the full range of bias, showing how the energetic disorder alone can give rise, in the space-charge limited current regime, to an I∝Vn dependence with an exponent n larger than 2.

A density functional theory study on the thermodynamic and dynamic properties of anthraquinone analogue cathode materials for rechargeable lithium ion batteries.

PubMed

Yang, Shu-Jing; Qin, Xiao-Ya; He, Rongxing; Shen, Wei; Li, Ming; Zhao, Liu-Bin

2017-05-21

Organic redox compounds have become the emerging electrode materials for rechargeable lithium ion batteries. The high electrochemical performance provides organic electrode materials with great opportunities to be applied in electric energy storage devices. Among the different types of organic materials, conjugated carbonyl compounds are the most promising type at present, because only they can simultaneously achieve, high energy density, high cycling stability, and high power density. In this research, a series of heteroatom substituted anthraquinone (AQ) derivatives were designed theoretically so that the high theoretical capacity of AQ remained. The discharge and charge mechanism as well as the thermodynamic and dynamic properties of AQ and its derivatives were investigated using first-principles density functional theory. Using heteroatom substitution, both the thermodynamic and dynamic properties of AQ as cathode materials could be largely improved. Among these conjugated carboxyl compounds, BDOZD and BDIOZD with a simultaneously high theoretical capacity and high working potential exhibit the largest energy density of about 780 W h kg -1 , which is 41% larger than that of AQ. The PQD with the smallest value of λ gives the largest charge transfer rate constant, which is about four times as large as the prototype molecule, AQ. The most interesting finding is that the lithium ion transfer plays a very important role in influencing both the discharge potential and electrochemical charge transfer rate. The present study illustrates that theoretical calculations provide a highly effective way to discover potential materials for use with rechargeable lithium ion batteries.

Constraining Bulk Densities of Near-Earth Asteroid Surfaces from Radar Observations Using Laboratory Measurements of Permittivity

NASA Astrophysics Data System (ADS)

Hickson, D. C.; Boivin, A.; Daly, M. G.; Ghent, R. R.; Nolan, M. C.; Tait, K.; Cunje, A.; Tsai, C. A.

2017-12-01

Planetary radar is widely used to survey the Near-Earth Asteroid (NEA) population and can provide insight into target shapes, sizes, and spin states. The dual-polarization reflectivity is sensitive to surface roughness as well as material properties, specifically the real part of the complex permittivity, or dielectric constant. Knowledge of the behavior of the dielectric constant of asteroid regolith analogue material with environmental parameters can be used to inversely solve for such parameters, such as bulk density, from radar observations. In this study laboratory measurements of the complex permittivity of powdered aluminum oxide and dunite samples are performed in a low-pressure environment chamber using a coaxial transmission line from roughly 1 GHz to 8.5 GHz. The bulk densities of the samples are varied across the measurements by incrementally adding silica aerogel, a low-density material with a very low dielectric constant. This allows the alteration of the proportions of void space to solid particle grains to achieve microgravity-relevant porosities without significantly altering the dielectric properties of the powder sample. The data are then modeled using various electromagnetic mixing equations to characterize the change in dielectric constant with increasing volume fractions of void space (decreasing bulk density). Using spectral analogues as constraints on the composition of NEAs allows us to calculate the range in bulk densities in the near surface of NEAs that have been observed by planetary radar. Utilizing existing radar data from Arecibo Observatory we calculate the bulk density in the near-surface on (101955) Bennu, the target of NASA's OSIRIS-Rex mission, to be ρ = 1.27 ± 0.33 g cm-3 based on an average of the likely range in particle density and dielectric constant of the regolith material.

Aqueous supercapacitors of high energy density based on MoO3 nanoplates as anode material.

PubMed

Tang, Wei; Liu, Lili; Tian, Shu; Li, Lei; Yue, Yunbo; Wu, Yuping; Zhu, Kai

2011-09-28

MoO(3) nanoplates were prepared as anode material for aqueous supercapacitors. They can deliver a high energy density of 45 W h kg(-1) at 450 W kg(-1) and even maintain 29 W h kg(-1) at 2 kW kg(-1) in 0.5 M Li(2)SO(4) aqueous electrolyte. These results present a new direction to explore non-carbon anode materials.

Nanoporous-carbon as a potential host material for reversible Mg ion intercalation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Siegal, Michael P.; Yelton, W. Graham; Perdue, Brian R.

Here, we study nanoporous-carbon (NPC) grown via pulsed laser deposition (PLD) as an electrically conductive anode host material for Mg 2+ intercalation. NPC has high surface area, and an open, accessible pore structure tunable via mass density that can improve diffusion. We fabricate 2032 coin cells using NPC coated stainless-steel disk anodes, metallic Mg cathodes, and a Grignard-based electrolyte. NPC mass density is controlled during growth, ranging from 0.06–1.3 g/cm 3. The specific surface area of NPC increases linearly from 1,000 to 1,700 m 2/g as mass density decreases from 1.3 to 0.26 g/cm 3, however, the surface area fallsmore » off dramatically at lower mass densities, implying a lack of mechanical integrity in such nanostructures. These structural characterizations correlate directly with coin cell electrochemical measurements. In particular, cyclic voltammetry (CV) scans for NPC with density ~0.5 g/cm 3 and BET surface area ~1500 m 2/g infer the possibility of reversible Mg-ion intercalation. Higher density NPC yields capacitive behavior, most likely resulting from the smaller interplanar spacings between graphene sheet fragments and tighter domain boundaries; lower density NPC results in asymmetrical CV scans, consistent with the likely structural degradation resulting from mass transport through soft, low-density carbon materials.« less

Nanoporous-carbon as a potential host material for reversible Mg ion intercalation

DOE PAGES

Siegal, Michael P.; Yelton, W. Graham; Perdue, Brian R.; ...

2016-03-25

Here, we study nanoporous-carbon (NPC) grown via pulsed laser deposition (PLD) as an electrically conductive anode host material for Mg 2+ intercalation. NPC has high surface area, and an open, accessible pore structure tunable via mass density that can improve diffusion. We fabricate 2032 coin cells using NPC coated stainless-steel disk anodes, metallic Mg cathodes, and a Grignard-based electrolyte. NPC mass density is controlled during growth, ranging from 0.06–1.3 g/cm 3. The specific surface area of NPC increases linearly from 1,000 to 1,700 m 2/g as mass density decreases from 1.3 to 0.26 g/cm 3, however, the surface area fallsmore » off dramatically at lower mass densities, implying a lack of mechanical integrity in such nanostructures. These structural characterizations correlate directly with coin cell electrochemical measurements. In particular, cyclic voltammetry (CV) scans for NPC with density ~0.5 g/cm 3 and BET surface area ~1500 m 2/g infer the possibility of reversible Mg-ion intercalation. Higher density NPC yields capacitive behavior, most likely resulting from the smaller interplanar spacings between graphene sheet fragments and tighter domain boundaries; lower density NPC results in asymmetrical CV scans, consistent with the likely structural degradation resulting from mass transport through soft, low-density carbon materials.« less

Application of a high-energy-density permanent magnet material in underwater systems

NASA Astrophysics Data System (ADS)

Cho, C. P.; Egan, C.; Krol, W. P.

1996-06-01

This paper addresses the application of high-energy-density permanent magnet (PM) technology to (1) the brushless, axial-field PM motor and (2) the integrated electric motor/pump system for under-water applications. Finite-element analysis and lumped parameter magnetic circuit analysis were used to calculate motor parameters and performance characteristics and to conduct tradeoff studies. Compact, efficient, reliable, and quiet underwater systems are attainable with the development of high-energy-density PM material, power electronic devices, and power integrated-circuit technology.

Unusual chemical compositions of noctilucent-cloud particle nuclei

NASA Technical Reports Server (NTRS)

Hemenway, C. L.

1973-01-01

Two sounding rocket payloads were launched from the ESRO range in Sweden during a noctilucent cloud display. Large numbers of submicron particles were collected, most of which appear to be made up of a high density material coated with a low density material. Typical electron micrographs are shown. Particle chemical compositions have been measured by use of dispersive X-ray analysis equipment attached to an electron microscope and have revealed that most of the high density particle nuclei have atomic weights greater than iron.

Measurements of LGS, LGN, and LGT thermal coefficients of expansion and density.

PubMed

Malocha, Donald C; François-Saint-Cyr, Hugues; Richardson, Kathleen; Helmbold, Robert

2002-03-01

This paper will report on the measurements of the thermal coefficients of expansion and density of langasite (LGS), langanite (LGN), and langatate (LGT). The data were obtained by fabricating cubes with X, Y, and Z faces with nominal dimensions of 1 cm on a side for each material under test. The techniques used for measurement of density and thermal coefficients of expansion (TCE) of the materials are discussed. The data sets obtained and the extracted coefficients are presented.

Non-lead, environmentally safe projectiles and method of making same

DOEpatents

Lowden, Richard A.; McCoig, Thomas M.; Dooley, Joseph B.

1998-01-01

A projectile, such as a bullet, is made by combining two different metals in proportions calculated to achieve a desired density, without using lead. A base constituent, made of a material having density greater than lead, is combined with a binder constituent having less density. The binder constituent is malleable and ductile metallic phase material that forms projectile shapes when subjected to a consolidation force, such as compression. The metal constituents can be selected, rationed, and consolidated to achieve desired frangibility characteristics.

Non-lead, environmentally safe projectiles and method of making same

DOEpatents

Lowden, Richard A.; McCoig, Thomas M.; Dooley, Joseph B.

2000-01-01

A projectile, such as a bullet, is made by combining two different metals in proportions calculated to achieve a desired density, without using lead. A base constituent, made of a material having density greater than lead, is combined with a binder constituent having less density. The binder constituent is malleable and ductile metallic phase material that forms projectile shapes when subjected to a consolidation force, such as compression. The metal constituents can be selected, rationed, and consolidated to achieve desired frangibility characteristics.

Non-lead environmentally safe projectiles and method of making same

DOEpatents

Lowden, Richard A.; McCoig, Thomas M.; Dooley, Joseph B.

1999-01-01

A projectile, such as a bullet, is made by combining two different metals in proportions calculated to achieve a desired density, without using lead. A base constituent, made of a material having density greater than lead, is combined with a binder constituent having less density. The binder constituent is malleable and ductile metallic base material that forms projectile shapes when subjected to a consolidation force, such as compression. The metal constituents can be selected, rationed, and consolidated to achieve desired frangibility characteristics.

Non-lead, environmentally safe projectiles and method of making same

DOEpatents

Lowden, R.A.; McCoig, T.M.; Dooley, J.B.

1998-06-02

A projectile, such as a bullet, is made by combining two different metals in proportions calculated to achieve a desired density, without using lead. A base constituent, made of a material having density greater than lead, is combined with a binder constituent having less density. The binder constituent is malleable and ductile metallic phase material that forms projectile shapes when subjected to a consolidation force, such as compression. The metal constituents can be selected, rationed, and consolidated to achieve desired frangibility characteristics. 7 figs.

The Quantitative Significance of Nondestructive Evaluation of Graphite and Ceramic Materials.

DTIC Science & Technology

NONDESTRUCTIVE TESTING), (* GRAPHITE , (*BORIDES, NONDESTRUCTIVE TESTING), (*REFRACTORY MATERIALS, NONDESTRUCTIVE TESTING), DEFECTS(MATERIALS), TENSILE PROPERTIES, RADIOGRAPHY, ULTRASONIC PROPERTIES, DENSITY.

High–energy density nonaqueous all redox flow lithium battery enabled with a polymeric membrane

PubMed Central

Jia, Chuankun; Pan, Feng; Zhu, Yun Guang; Huang, Qizhao; Lu, Li; Wang, Qing

2015-01-01

Redox flow batteries (RFBs) are considered one of the most promising large-scale energy storage technologies. However, conventional RFBs suffer from low energy density due to the low solubility of the active materials in electrolyte. On the basis of the redox targeting reactions of battery materials, the redox flow lithium battery (RFLB) demonstrated in this report presents a disruptive approach to drastically enhancing the energy density of flow batteries. With LiFePO4 and TiO2 as the cathodic and anodic Li storage materials, respectively, the tank energy density of RFLB could reach ~500 watt-hours per liter (50% porosity), which is 10 times higher than that of a vanadium redox flow battery. The cell exhibits good electrochemical performance under a prolonged cycling test. Our prototype RFLB full cell paves the way toward the development of a new generation of flow batteries for large-scale energy storage. PMID:26702440

Repetition rates in heavy ion beam driven fusion reactors

NASA Astrophysics Data System (ADS)

Peterson, Robert R.

1986-01-01

The limits on the cavity gas density required for beam propagation and condensation times for material vaporized by target explosions can determine the maximum repetition rate of Heavy Ion Beam (HIB) driven fusion reactors. If the ions are ballistically focused onto the target, the cavity gas must have a density below roughly 10-4 torr (3×1012 cm-3) at the time of propagation; other propagation schemes may allow densities as high as 1 torr or more. In some reactor designs, several kilograms of material may be vaporized off of the target chamber walls by the target generated x-rays, raising the average density in the cavity to 100 tor or more. A one-dimensional combined radiation hydrodynamics and vaporization and condensation computer code has been used to simulate the behavior of the vaporized material in the target chambers of HIB fusion reactors.

Nitrogen-doped carbon spheres: A new high-energy-density and long-life pseudo-capacitive electrode material for electrochemical flow capacitor.

PubMed

Hou, Shujin; Wang, Miao; Xu, Xingtao; Li, Yandong; Li, Yanjiang; Lu, Ting; Pan, Likun

2017-04-01

One of the most challenging issues in developing electrochemical flow capacitor (EFC) technology is the design and synthesis of active electrode materials with high energy density and long cycle life. However, in practical cases, the energy density and cycle ability obtained currently cannot meet the practical need. In this work, we propose a new active material, nitrogen-doped carbon spheres (NCSs), as flowable electrodes for EFC application. The NCSs were prepared via one-pot hydrothermal synthesis in the presence of resorcinol/formaldehyde as carbon precursors and melamine as nitrogen precursor, followed by carbonization in nitrogen flow at various temperatures. The results of EFC experiments demonstrate that NCSs obtained at 800°C exhibit a high energy density of 13.5Whkg -1 and an excellent cycle ability, indicating the superiority of NCSs for EFC application. Copyright © 2016 Elsevier Inc. All rights reserved.

High-energy density nonaqueous all redox flow lithium battery enabled with a polymeric membrane.

PubMed

Jia, Chuankun; Pan, Feng; Zhu, Yun Guang; Huang, Qizhao; Lu, Li; Wang, Qing

2015-11-01

Redox flow batteries (RFBs) are considered one of the most promising large-scale energy storage technologies. However, conventional RFBs suffer from low energy density due to the low solubility of the active materials in electrolyte. On the basis of the redox targeting reactions of battery materials, the redox flow lithium battery (RFLB) demonstrated in this report presents a disruptive approach to drastically enhancing the energy density of flow batteries. With LiFePO4 and TiO2 as the cathodic and anodic Li storage materials, respectively, the tank energy density of RFLB could reach ~500 watt-hours per liter (50% porosity), which is 10 times higher than that of a vanadium redox flow battery. The cell exhibits good electrochemical performance under a prolonged cycling test. Our prototype RFLB full cell paves the way toward the development of a new generation of flow batteries for large-scale energy storage.

Polymer Composite and Nanocomposite Dielectric Materials for Pulse Power Energy Storage †

PubMed Central

Barber, Peter; Balasubramanian, Shiva; Anguchamy, Yogesh; Gong, Shushan; Wibowo, Arief; Gao, Hongsheng; Ploehn, Harry J.; zur Loye, Hans-Conrad

2009-01-01

This review summarizes the current state of polymer composites used as dielectric materials for energy storage. The particular focus is on materials: polymers serving as the matrix, inorganic fillers used to increase the effective dielectric constant, and various recent investigations of functionalization of metal oxide fillers to improve compatibility with polymers. We review the recent literature focused on the dielectric characterization of composites, specifically the measurement of dielectric permittivity and breakdown field strength. Special attention is given to the analysis of the energy density of polymer composite materials and how the functionalization of the inorganic filler affects the energy density of polymer composite dielectric materials.

An Integrated, Layered-Spinel Composite Cathode for Energy Storage Applications

NASA Technical Reports Server (NTRS)

Hagh, Nader; Skandan, Ganesh

2012-01-01

At low operating temperatures, commercially available electrode materials for lithium-ion batteries do not fully meet the energy and power requirements for NASA fs exploration activities. The composite cathode under development is projected to provide the required energy and power densities at low temperatures and its usage will considerably reduce the overall volume and weight of the battery pack. The newly developed composite electrode material can provide superior electrochemical performance relative to a commercially available lithium cobalt system. One advantage of using a composite cathode is its higher energy density, which can lead to smaller and lighter battery packs. In the current program, different series of layered-spinel composite materials with at least two different systems in an integrated structure were synthesized, and the volumetric and gravimetric energy densities were evaluated. In an integrated network of a composite electrode, the effect of the combined structures is to enhance the capacity and power capabilities of the material to levels greater than what is possible in current state-of-the-art cathode systems. The main objective of the current program is to implement a novel cathode material that meets NASA fs low temperature energy density requirements. An important feature of the composite cathode is that it has at least two components (e.g., layered and spinel) that are structurally integrated. The layered material by itself is electrochemically inactive; however, upon structural integration with a spinel material, the layered material can be electrochemically activated, thereby delivering a large amount of energy with stable cycling. A key aspect of the innovation has been the development of a scalable process to produce submicronand micron-scale particles of these composite materials. An additional advantage of using such a composite electrode material is its low irreversible loss (.5%), which is primarily due to the unique activation of the composite. High columbic efficiency (greater than 99%) upon cycling may indicate the formation of a stable SEI (solid-electrolyte interface) layer, which can contribute to long cycle life. The innovation in the current program, when further developed, will enable the system to maintain high energy and power densities at low temperatures, improve efficiency, and further stabilize and enhance the safety of the cell.

Use of alternative carrier materials in AOAC Official Method 2008.05, efficacy of liquid sporicides against spores of Bacillus subtilis on a hard, nonporous surface, quantitative three-step method.

PubMed

Tomasino, Stephen F; Rastogi, Vipin K; Wallace, Lalena; Smith, Lisa S; Hamilton, Martin A; Pines, Rebecca M

2010-01-01

The quantitative Three-Step Method (TSM) for testing the efficacy of liquid sporicides against spores of Bacillus subtilis on a hard, nonporous surface (glass) was adopted as AOAC Official Method 2008.05 in May 2008. The TSM uses 5 x 5 x 1 mm coupons (carriers) upon which spores have been inoculated and which are introduced into liquid sporicidal agent contained in a microcentrifuge tube. Following exposure of inoculated carriers and neutralization, spores are removed from carriers in three fractions (gentle washing, fraction A; sonication, fraction B; and gentle agitation, fraction C). Liquid from each fraction is serially diluted and plated on a recovery medium for spore enumeration. The counts are summed over the three fractions to provide the density (viable spores per carrier), which is log10-transformed to arrive at the log density. The log reduction is calculated by subtracting the mean log density for treated carriers from the mean log density for control carriers. This paper presents a single-laboratory investigation conducted to evaluate the applicability of using two porous carrier materials (ceramic tile and untreated pine wood) and one alternative nonporous material (stainless steel). Glass carriers were included in the study as the reference material. Inoculated carriers were evaluated against three commercially available liquid sporicides (sodium hypochlorite, a combination of peracetic acid and hydrogen peroxide, and glutaraldehyde), each at two levels of presumed efficacy (medium and high) to provide data for assessing the responsiveness of the TSM. Three coupons of each material were evaluated across three replications at each level; three replications of a control were required. Even though all carriers were inoculated with approximately the same number of spores, the observed counts of recovered spores were consistently higher for the nonporous carriers. For control carriers, the mean log densities for the four materials ranged from 6.63 for wood to 7.14 for steel. The pairwise differences between mean log densities, except for glass minus steel, were statistically significant (P < 0.001). The repeatability standard deviations (Sr) for the mean control log density per test were similar for the four materials, ranging from 0.08 for wood to 0.13 for tile. Spore recovery from the carrier materials ranged from approximately 20 to 70%: 20% (pine wood), 40% (ceramic tile), 55% (glass), and 70% (steel). Although the percent spore recovery from pine wood was significantly lower than that from other materials, the performance data indicate that the TSM provides a repeatable and responsive test for determining the efficacy of liquid sporicides on both porous and nonporous materials.

Standing Waves in a Nonuniform Medium

ERIC Educational Resources Information Center

Gluck, Paul

2011-01-01

A recent note in this journal presented a demonstration of standing waves along a cord consisting of two parts having different material densities, showing different sized wavelengths in each part. A generalization of that experiment to a continuously varying linear mass density is to vibrate a strip of material with gradually varying width (mass…

How to Tell What's Underground.

ERIC Educational Resources Information Center

Bartholomew, Rolland B.

Presented is a suggested instructional lesson based on important clues that lead to a better understanding of the kinds of materials that lie under and within the earth's crust. Comparing density of earth rocks to density of the whole earth, and accounting for the discrepancy, leads to awareness of the difference of materials of the earth's…

Novel LLM series high density energy materials: Synthesis, characterization, and thermal stability

NASA Astrophysics Data System (ADS)

Pagoria, Philip; Zhang, Maoxi; Tsyshevskiy, Roman; Kuklja, Maija

Novel high density energy materials must satisfy specific requirements, such as an increased performance, reliably high stability to external stimuli, cost-efficiency and ease of synthesis, be environmentally benign, and be safe for handling and transportation. During the last decade, the attention of researchers has drifted from widely used nitroester-, nitramine-, and nitroaromatic-based explosives to nitrogen-rich heterocyclic compounds. Good thermal stability, the low melting point, high density, and moderate sensitivity make heterocycle materials attractive candidates for use as oxidizers in rocket propellants and fuels, secondary explosives, and possibly as melt-castable ingredients of high explosive formulations. In this report, the synthesis, characterization, and results of quantum-chemical DFT study of thermal stability of LLM-191, LLM-192 and LLM-200 high density energy materials are presented. Work performed under the auspices of the DOE by the LLNL (Contract DE-AC52-07NA27344). This research is supported in part by ONR (Grant N00014-12-1-0529) and NSF. We used NSF XSEDE (Grant DMR-130077) and DOE NERSC (Contract DE-AC02-05CH11231) resources.

Negative-pressure polymorphs made by heterostructural alloying

PubMed Central

Perkins, John D.

2018-01-01

The ability of a material to adopt multiple structures, known as polymorphism, is a fascinating natural phenomenon. Various polymorphs with unusual properties are routinely synthesized by compression under positive pressure. However, changing a material’s structure by applying tension under negative pressure is much more difficult. We show how negative-pressure polymorphs can be synthesized by mixing materials with different crystal structures—a general approach that should be applicable to many materials. Theoretical calculations suggest that it costs less energy to mix low-density structures than high-density structures, due to less competition for space between the atoms. Proof-of-concept experiments confirm that mixing two different high-density forms of MnSe and MnTe stabilizes a Mn(Se,Te) alloy with a low-density wurtzite structure. This Mn(Se,Te) negative-pressure polymorph has 2× to 4× lower electron effective mass compared to MnSe and MnTe parent compounds and has a piezoelectric response that none of the parent compounds have. This example shows how heterostructural alloying can lead to negative-pressure polymorphs with useful properties—materials that are otherwise nearly impossible to make. PMID:29725620

Tube-Super Dielectric Materials: Electrostatic Capacitors with Energy Density Greater than 200 J·cm−3

PubMed Central

Cortes, Francisco Javier Quintero; Phillips, Jonathan

2015-01-01

The construction and performance of a second generation of super dielectric material based electrostatic capacitors (EC), with energy density greater than 200 J·cm−3, which rival the best reported energy density of electric double layer capacitors (EDLC), also known as supercapacitors, are reported. The first generation super dielectric materials (SDM) are multi-material mixtures with dielectric constants greater than 1.0 × 105, composed of a porous, electrically insulating powder filled with a polarizable, ion-containing liquid. Second-generation SDMs (TSDM), introduced here, are anodic titania nanotube arrays filled with concentrated aqueous salt solutions. Capacitors using TiO2 based TSDM were found to have dielectric constants at ~0 Hz greater than 107 in all cases, a maximum operating voltage of greater than 2 volts and remarkable energy density that surpasses the highest previously reported for EC capacitors by approximately one order of magnitude. A simple model based on the classic ponderable media model was shown to be largely consistent with data from nine EC type capacitors employing TSDM. PMID:28793561

Tube-Super Dielectric Materials: Electrostatic Capacitors with Energy Density Greater than 200 J·cm-3.

PubMed

Cortes, Francisco Javier Quintero; Phillips, Jonathan

2015-09-17

The construction and performance of a second generation of super dielectric material based electrostatic capacitors (EC), with energy density greater than 200 J·cm - ³, which rival the best reported energy density of electric double layer capacitors (EDLC), also known as supercapacitors, are reported. The first generation super dielectric materials (SDM) are multi-material mixtures with dielectric constants greater than 1.0 × 10⁵, composed of a porous, electrically insulating powder filled with a polarizable, ion-containing liquid. Second-generation SDMs (TSDM), introduced here, are anodic titania nanotube arrays filled with concentrated aqueous salt solutions. Capacitors using TiO₂ based TSDM were found to have dielectric constants at ~0 Hz greater than 10⁷ in all cases, a maximum operating voltage of greater than 2 volts and remarkable energy density that surpasses the highest previously reported for EC capacitors by approximately one order of magnitude. A simple model based on the classic ponderable media model was shown to be largely consistent with data from nine EC type capacitors employing TSDM.

A Method to Improve Electron Density Measurement of Cone-Beam CT Using Dual Energy Technique

PubMed Central

Men, Kuo; Dai, Jian-Rong; Li, Ming-Hui; Chen, Xin-Yuan; Zhang, Ke; Tian, Yuan; Huang, Peng; Xu, Ying-Jie

2015-01-01

Purpose. To develop a dual energy imaging method to improve the accuracy of electron density measurement with a cone-beam CT (CBCT) device. Materials and Methods. The imaging system is the XVI CBCT system on Elekta Synergy linac. Projection data were acquired with the high and low energy X-ray, respectively, to set up a basis material decomposition model. Virtual phantom simulation and phantoms experiments were carried out for quantitative evaluation of the method. Phantoms were also scanned twice with the high and low energy X-ray, respectively. The data were decomposed into projections of the two basis material coefficients according to the model set up earlier. The two sets of decomposed projections were used to reconstruct CBCT images of the basis material coefficients. Then, the images of electron densities were calculated with these CBCT images. Results. The difference between the calculated and theoretical values was within 2% and the correlation coefficient of them was about 1.0. The dual energy imaging method obtained more accurate electron density values and reduced the beam hardening artifacts obviously. Conclusion. A novel dual energy CBCT imaging method to calculate the electron densities was developed. It can acquire more accurate values and provide a platform potentially for dose calculation. PMID:26346510

Ultrasonic fluid densitometer for process control

DOEpatents

Greenwood, Margaret S.

2000-01-01

The present invention is an ultrasonic fluid densitometer that uses at least one pair of transducers for transmitting and receiving ultrasonic signals internally reflected within a material wedge. A temperature sensor is provided to monitor the temperature of the wedge material. Density of a fluid is determined by immersing the wedge into the fluid and measuring reflection of ultrasound at the wedge-fluid interface and comparing a transducer voltage and wedge material temperature to a tabulation as a function of density.

Structural design of graphene for use in electrochemical energy storage devices.

PubMed

Chen, Kunfeng; Song, Shuyan; Liu, Fei; Xue, Dongfeng

2015-10-07

There are many practical challenges in the use of graphene materials as active components in electrochemical energy storage devices. Graphene has a much lower capacitance than the theoretical capacitance of 550 F g(-1) for supercapacitors and 744 mA h g(-1) for lithium ion batteries. The macroporous nature of graphene limits its volumetric energy density and the low packing density of graphene-based electrodes prevents its use in commercial applications. Increases in the capacity, energy density and power density of electroactive graphene materials are strongly dependent on their microstructural properties, such as the number of defects, stacking, the use of composite materials, conductivity, the specific surface area and the packing density. The structural design of graphene electrode materials is achieved via six main strategies: the design of non-stacking and three-dimensional graphene; the synthesis of highly packed graphene; the production of graphene with a high specific surface area and high conductivity; the control of defects; functionalization with O, N, B or P heteroatoms; and the formation of graphene composites. These methodologies of structural design are needed for fast electrical charge storage/transfer and the transport of electrolyte ions (Li(+), H(+), K(+), Na(+)) in graphene electrodes. We critically review state-of-the-art progress in the optimization of the electrochemical performance of graphene-based electrode materials. The structure of graphene needs to be designed to develop novel electrochemical energy storage devices that approach the theoretical charge limit of graphene and to deliver electrical energy rapidly and efficiently.

Dynamic behaviour of interphases and its implication on high-energy-density cathode materials in lithium-ion batteries

PubMed Central

Li, Wangda; Dolocan, Andrei; Oh, Pilgun; Celio, Hugo; Park, Suhyeon; Cho, Jaephil; Manthiram, Arumugam

2017-01-01

Undesired electrode–electrolyte interactions prevent the use of many high-energy-density cathode materials in practical lithium-ion batteries. Efforts to address their limited service life have predominantly focused on the active electrode materials and electrolytes. Here an advanced three-dimensional chemical and imaging analysis on a model material, the nickel-rich layered lithium transition-metal oxide, reveals the dynamic behaviour of cathode interphases driven by conductive carbon additives (carbon black) in a common nonaqueous electrolyte. Region-of-interest sensitive secondary-ion mass spectrometry shows that a cathode-electrolyte interphase, initially formed on carbon black with no electrochemical bias applied, readily passivates the cathode particles through mutual exchange of surface species. By tuning the interphase thickness, we demonstrate its robustness in suppressing the deterioration of the electrode/electrolyte interface during high-voltage cell operation. Our results provide insights on the formation and evolution of cathode interphases, facilitating development of in situ surface protection on high-energy-density cathode materials in lithium-based batteries. PMID:28443608

Process for preparing energetic materials

DOEpatents

Simpson, Randall L [Livermore, CA; Lee, Ronald S [Livermore, CA; Tillotson, Thomas M [Tracy, CA; Hrubesh, Lawrence W [Pleasanton, CA; Swansiger, Rosalind W [Livermore, CA; Fox, Glenn A [Livermore, CA

2011-12-13

Sol-gel chemistry is used for the preparation of energetic materials (explosives, propellants and pyrotechnics) with improved homogeneity, and/or which can be cast to near-net shape, and/or made into precision molding powders. The sol-gel method is a synthetic chemical process where reactive monomers are mixed into a solution, polymerization occurs leading to a highly cross-linked three dimensional solid network resulting in a gel. The energetic materials can be incorporated during the formation of the solution or during the gel stage of the process. The composition, pore, and primary particle sizes, gel time, surface areas, and density may be tailored and controlled by the solution chemistry. The gel is then dried using supercritical extraction to produce a highly porous low density aerogel or by controlled slow evaporation to produce a xerogel. Applying stress during the extraction phase can result in high density materials. Thus, the sol-gel method can be used for precision detonator explosive manufacturing as well as producing precision explosives, propellants, and pyrotechnics, along with high power composite energetic materials.

Sol-Gel Manufactured Energetic Materials

DOEpatents

Simpson, Randall L.; Lee, Ronald S.; Tillotson, Thomas M.; Hrubesh, Lawrence W.; Swansiger, Rosalind W.; Fox, Glenn A.

2005-05-17

Sol-gel chemistry is used for the preparation of energetic materials (explosives, propellants and pyrotechnics) with improved homogeneity, and/or which can be cast to near-net shape, and/or made into precision molding powders. The sol-gel method is a synthetic chemical process where reactive monomers are mixed into a solution, polymerization occurs leading to a highly cross-linked three dimensional solid network resulting in a gel. The energetic materials can be incorporated during the formation of the solution or during the gel stage of the process. The composition, pore, and primary particle sizes, gel time, surface areas, and density may be tailored and controlled by the solution chemistry. The gel is then dried using supercritical extraction to produce a highly porous low density aerogel or by controlled slow evaporation to produce a xerogel. Applying stress during the extraction phase can result in high density materials. Thus, the sol-gel method can be used for precision detonator explosive manufacturing as well as producing precision explosives, propellants, and pyrotechnics, along with high power composite energetic materials.

Sol-gel manufactured energetic materials

DOEpatents

Simpson, Randall L.; Lee, Ronald S.; Tillotson, Thomas M.; Hrubesh, Lawrence W.; Swansiger, Rosalind W.; Fox, Glenn A.

2003-12-23

Sol-gel chemistry is used for the preparation of energetic materials (explosives, propellants and pyrotechnics) with improved homogeneity, and/or which can be cast to near-net shape, and/or made into precision molding powders. The sol-gel method is a synthetic chemical process where reactive monomers are mixed into a solution, polymerization occurs leading to a highly cross-linked three dimensional solid network resulting in a gel. The energetic materials can be incorporated during the formation of the solution or during the gel stage of the process. The composition, pore, and primary particle sizes, gel time, surface areas, and density may be tailored and controlled by the solution chemistry. The gel is then dried using supercritical extraction to produce a highly porous low density aerogel or by controlled slow evaporation to produce a xerogel. Applying stress during the extraction phase can result in high density materials. Thus, the sol-gel method can be used for precision detonator explosive manufacturing as well as producing precision explosives, propellants, and pyrotechnics, along with high power composite energetic materials.

Synthesis of carbon core–shell pore structures and their performance as supercapacitors

DOE PAGES

Ariyanto, Teguh; Dyatkin, Boris; Zhang, Gui-Rong; ...

2015-07-15

High-power supercapacitors require excellent electrolyte mobility within the pore network and high electrical conductivity for maximum capacitance and efficiency. Achieving high power typically requires sacrificing energy densities, as the latter demands a high specific surface area and narrow porosity that impedes ion transport. Here, we present a novel solution for this optimization problem: a nanostructured core–shell carbonaceous material that exhibits a microporous carbon core surrounded by a mesoporous, graphitic shell. The tunable synthesis parameters yielded a structure that features either a sharp or a gradual transition between the core and shell sections. Electrochemical supercapacitor testing using organic electrolyte revealed thatmore » these novel core–shell materials outperform carbons with homogeneous pore structures. The hybrid core–shell materials showed a combination of good capacitance retention, typical for the carbon present in the shell and high specific capacitance, typical for the core material. These materials achieved power densities in excess of 40 kW kg -1 at energy densities reaching 27 Wh kg -1.« less

Dynamic behaviour of interphases and its implication on high-energy-density cathode materials in lithium-ion batteries

NASA Astrophysics Data System (ADS)

Li, Wangda; Dolocan, Andrei; Oh, Pilgun; Celio, Hugo; Park, Suhyeon; Cho, Jaephil; Manthiram, Arumugam

2017-04-01

Undesired electrode-electrolyte interactions prevent the use of many high-energy-density cathode materials in practical lithium-ion batteries. Efforts to address their limited service life have predominantly focused on the active electrode materials and electrolytes. Here an advanced three-dimensional chemical and imaging analysis on a model material, the nickel-rich layered lithium transition-metal oxide, reveals the dynamic behaviour of cathode interphases driven by conductive carbon additives (carbon black) in a common nonaqueous electrolyte. Region-of-interest sensitive secondary-ion mass spectrometry shows that a cathode-electrolyte interphase, initially formed on carbon black with no electrochemical bias applied, readily passivates the cathode particles through mutual exchange of surface species. By tuning the interphase thickness, we demonstrate its robustness in suppressing the deterioration of the electrode/electrolyte interface during high-voltage cell operation. Our results provide insights on the formation and evolution of cathode interphases, facilitating development of in situ surface protection on high-energy-density cathode materials in lithium-based batteries.

Metal hydride-based thermal energy storage systems

DOEpatents

Vajo, John J.; Fang, Zhigang

2017-10-03

The invention provides a thermal energy storage system comprising a metal-containing first material with a thermal energy storage density of about 1300 kJ/kg to about 2200 kJ/kg based on hydrogenation; a metal-containing second material with a thermal energy storage density of about 200 kJ/kg to about 1000 kJ/kg based on hydrogenation; and a hydrogen conduit for reversibly transporting hydrogen between the first material and the second material. At a temperature of 20.degree. C. and in 1 hour, at least 90% of the metal is converted to the hydride. At a temperature of 0.degree. C. and in 1 hour, at least 90% of the metal hydride is converted to the metal and hydrogen. The disclosed metal hydride materials have a combination of thermodynamic energy storage densities and kinetic power capabilities that previously have not been demonstrated. This performance enables practical use of thermal energy storage systems for electric vehicle heating and cooling.

Improvement of mechanical strength of sintered Mo alloyed steel by optimization of sintering and cold-forging processes with densification

NASA Astrophysics Data System (ADS)

Kamakoshi, Y.; Shohji, I.; Inoue, Y.; Fukuda, S.

2017-10-01

Powder metallurgy (P/M) materials have been expected to be spread in automotive industry. Generally, since sintered materials using P/M ones contain many pores and voids, mechanical properties of them are inferior to those of conventional wrought materials. To improve mechanical properties of the sintered materials, densification is effective. The aim of this study is to improve mechanical strength of sintered Mo-alloyed steel by optimizing conditions in sintering and cold-forging processes. Mo-alloyed steel powder was compacted. Then, pre-sintering (PS) using a vacuum sintering furnace was conducted. Subsequently, coldforging (CF) by a backward extrusion method was conducted to the pre-sintered specimen. Moreover, the cold-forged specimen was heat treated by carburizing, tempering and quenching (CQT). Afterwards, mechanical properties were investigated. As a result, it was found that the density of the PS specimen is required to be more than 7.4 Mg/m3 to strengthen the specimen by heat treatment after CF. Furthermore, density and the microstructure of the PS specimen are most important factors to make the high density and strength material by CF. At the CF load of 1200 kN, the maximum density ratio reached approximately 99% by the use of the PS specimen with proper density and microstructure. At the CF load of 900 kN, although density ratio was high like more than 97.8%, transverse rupture strength decreased sharply. Since densification caused high shear stress and stress concentration in the surface layer, microcracks occurred by the damages of inter-particle sintered connection of the surface layer. On the contrary, in case of the CF load of 1200 kN, ultra-densification of the surface layer occurred by a sufficient plastic flow. Such sufficient compressed specimens regenerated the sintered connections by high temperature heat treatment and thus the high strength densified material was obtained. These processes can be applicable to near net shape manufacturing without surface machining.

Effect of object location on the density measurement and Hounsfield conversion in a NewTom 3G cone beam computed tomography unit.

PubMed

Lagravère, M O; Carey, J; Ben-Zvi, M; Packota, G V; Major, P W

2008-09-01

The purpose of this study was to determine the effect of an object's location in a cone beam CT imaging chamber (CBCT-NewTom 3G) on its apparent density and to develop a linear conversion coefficient for Hounsfield units (HU) to material density (g cm(-3)) for the NewTom 3G Scanner. Three cylindrical models of materials with different densities were constructed and scanned at five different locations in a NewTom 3G Volume Scanner. The average HU value for each model at each location was obtained using two different types of software. Next, five cylinders of different known densities were scanned at the exact centre of a NewTom 3G Scanner. The collected data were analysed using the same two types of software to determine a standard linear relationship between density and HU for each type of software. There is no statistical significance of location of an object within the CBCT scanner on determination of its density. A linear relationship between the density of an object and the HU of a scan was rho = 0.001(HU)+1.19 with an R2 value of 0.893 (where density, rho, is measured in g cm(-3)). This equation is to be used on a range between 1.42 g cm(-3) and 0.4456 g cm(-3). A linear relationship can be used to determine the density of materials (in the density range of bone) from the HU values of a CBCT scan. This relationship is not affected by the object's location within the scanner itself.

Behavior of Bubble Interfaces Stabilized by Particles of Different Densities.

PubMed

Bournival, Ghislain; Ata, Seher; Wanless, Erica J

2016-06-28

Stability of bubbles laden with particles of different densities was investigated. Capillary-held bubbles were produced and coated with particles across the density range of 1.2-3.6 g·cm(-3). The materials used were poly(methyl methacrylate) (PMMA), glass, and anatase. The interaction of the bubbles, once brought into contact, was monitored using high-speed video recording. Visual inspection indicated that denser particles were more easily displaced during the contact of the bubbles and therefore the PMMA particles provided a particle barrier more resistant to coalescence. The coalescence events yielded information on the surface properties of the bubble and the detachment of particles. The attached particles commonly dampen the oscillation of the coalesced bubbles through viscous drag and change in the surface properties (e.g., area-exclusion principle). The dampening of the oscillation generally leads to a reduced mass of particles detaching from the bubble surface. It was found that the different materials investigated did not offer clear evidence of the effect of particle detachment on the bubble surface properties in the present systems. On the other hand, the detachment of different particle materials seemed to be consistent with one another when comparing the attachment and detachment forces exerted on the particles based on their density, size, and hydrophobicity. It was concluded that particles of lower density are more effective in stabilizing interfaces, and thus particle density is an important parameter in the selection of materials for the handling of dispersions.

How do roll compaction/dry granulation affect the tableting behaviour of inorganic materials? Comparison of four magnesium carbonates.

PubMed

Freitag, Franziska; Kleinebudde, Peter

2003-07-01

The effect of roll compaction/dry granulation on the particle and bulk material characteristics of different magnesium carbonates was evaluated. The flowability of all materials could be improved, even by the application of low specific compaction forces. The tablet properties made of powder and dry granulated magnesium carbonate were compared. Roll compaction/dry granulation resulted in a modified compactibility of the material and, consequently, tablets with reduced tensile strength. The higher relative tap density of the compacted material does not allow a densification to the same extent as the uncompacted powder. The degree of densification during tableting can be expressed as the ratio of the relative tablet density to the relative tap density of the feed material. Increasing the specific compaction forces resulted in higher apparent mean yield pressure, gained from Heckel plots, of all materials analysed. The partial loss of compactibility leads to the demand of low loads during roll compaction. Comparing the tablet properties of different magnesium carbonates reveals an obvious capping disposition. However, it depends on the type of magnesium carbonate, the specific compaction force and also on the tableting force applied.

Method of varying a physical property of a material through its depth

DOEpatents

Daniel, Claus

2015-04-21

A method is disclosed for varying a mechanical property of a material at two depths. The method involves the application of at least two laser pulses of different durations. The method involves a determination of the density of the material from the surface to each depth, a determination of the heat capacity of the material from the surface to each depth, and a determination of the thermal conductivity of the material from the surface to each depth. Each laser pulse may affect the density, heat capacity, and thermal conductivity of the material, so it may be necessary to re-evaluate those parameters after each laser pulse and prior to the next pulse. The method may be applied to implantation materials to improve osteoblast and osteoclast activity.

Computer Tomograph (CT) imaging of mandibular anatomical substrate in animal model restored with nanostructured hydroxyapatite compounds

PubMed Central

Ciuluvică, R; Grădinaru, S; Popescu, M; Piticescu, RM; Cergan, R

2015-01-01

Introduction: This study was meant to test a new type of bone graft on an animal model. This material was a nanostructured hydroxyapatite. Materials and Methods: the study was conducted according to Ethic Committee Regulation on animal model (Oryctolagus cuniculus – rabbit) between August and November 2014, at “Carol Davila” University of Medicine and Pharmacy, Bucharest. The animals were tested by using a CT at the level of the mandible before and after using the nanostructured hydroxyapatite. Results: The animals were CT scanned at 1, 2 and respectively 3 months, noticing a growth of the mandibular bone density. After 3 months, a bone density equal with the density of the healthy bone was noticed. Conclusions: The use of the bone graft could be a viable alternative to available materials. The advantage was that bone recovery had a density similar to the density of the healthy bone and the cost of production was low because it was made out of Calcium azotate and monobasic ammonium phosphate. PMID:25914749

Emergence of charge density waves and a pseudogap in single-layer TiTe 2

DOE PAGES

Chen, P.; Pai, Woei Wu; Chan, Y. -H.; ...

2017-09-11

Two-dimensional materials constitute a promising platform for developing nanoscale devices and systems. Their physical properties can be very different from those of the corresponding three-dimensional materials because of extreme quantum confinement and dimensional reduction. Here in this paper we report a study of TiTe 2 from the single-layer to the bulk limit. Using angle-resolved photoemission spectroscopy and scanning tunneling microscopy and spectroscopy, we observed the emergence of a (2 × 2) charge density wave order in single-layer TiTe 2 with a transition temperature of 92 ± 3 K. Also observed was a pseudogap of about 28 meV at the Fermimore » level at 4.2 K. Surprisingly, no charge density wave transitions were observed in two-layer and multi-layer TiTe 2 , despite the quasi-two-dimensional nature of the material in the bulk. The unique charge density wave phenomenon in the single layer raises intriguing questions that challenge the prevailing thinking about the mechanisms of charge density wave formation.« less

Analysis of defect structure in silicon. Effect of grain boundary density on carrier mobility in UCP material

NASA Technical Reports Server (NTRS)

Dunn, J.; Stringfellow, G. B.; Natesh, R.

1982-01-01

The relationships between hole mobility and grain boundary density were studied. Mobility was measured using the van der Pauw technique, and grain boundary density was measured using a quantitative microscopy technique. Mobility was found to decrease with increasing grain boundary density.

Molecular engineering of polymer actuators for biomedical and industrial use

NASA Astrophysics Data System (ADS)

Banister, Mark; Eichorst, Rebecca; Gurr, Amy; Schweitzer, Georgette; Geronov, Yordan; Rao, Pavalli; McGrath, Dominic

2012-04-01

Five key materials engineering components and how each component impacted the working performance of a polymer actuator material are investigated. In our research we investigated the change of actuation performance that occurred with each change we made to the material. We investigated polymer crosslink density, polymer chain length, polymer gelation, type and density of reactive units, as well as the addition of binders to the polymer matrix. All five play a significant role and need to be addressed at the molecular level to optimize a polymer gel for use as a practical actuator material for biomedical and industrial use.

Fabrication of aerogel capsule, bromine-doped capsule, and modified gold cone in modified target for the Fast Ignition Realization Experiment (FIREX) Project

NASA Astrophysics Data System (ADS)

Nagai, Keiji; Yang, H.; Norimatsu, T.; Azechi, H.; Belkada, F.; Fujimoto, Y.; Fujimura, T.; Fujioka, K.; Fujioka, S.; Homma, H.; Ito, F.; Iwamoto, A.; Jitsuno, T.; Kaneyasu, Y.; Nakai, M.; Nemoto, N.; Saika, H.; Shimoyama, T.; Suzuki, Y.; Yamanaka, K.; Mima, K.

2009-09-01

The development of target fabrication for the Fast Ignition Realization EXperiment (FIREX) Project is described in this paper. For the first stage of the FIREX Project (FIREX-I), the previously designed target has been modified by using a bromine-doped ablator and coating the inner gold cone with a low-density material. A high-quality bromine-doped capsule without vacuoles was fabricated from bromine-doped deuterated polystyrene. The gold surface was coated with a low-density material by electrochemical plating. For the cryogenic fuel target, a brand new type of aerogel material, phloroglucinol/formaldehyde (PF), was investigated and encapsulated to meet the specifications of 500 µm diameter and 20 µm thickness, with 30 nm nanopores. Polystyrene-based low-density materials were investigated and the relationship between the crosslinker content and the nanopore structure was observed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yeager, John D.; Higginbotham Duque, Amanda L.; Shorty, Marvin

Inert surrogates or mocks for high explosives are commonly used in place of the real material for complex experiments or in situations where safety is a concern. We tested several materials as potential mocks for HMX in terms of density, thermal stability, and processability. Selection criteria were developed and a literature search was conducted primarily using the Cambridge Structural Database. Moreover, out of over 200 potentially acceptable materials, six were chosen for crystallization experiments and a suite of analytical characterization. Of these six, 5-iodo-2'-deoxyuridine, N,N'-bis(2,3,4,5,6-pentafluorophenyl)oxamide, and 2,3,4,5,6-pentafluorobenzamide all were found to be thermally stable at 150°C, matched HMX density asmore » a pressed pellet, and could be crystallized to appropriate particle sizes. These three materials are considered suitable inert density mocks for HMX and will be the subject of future testing.« less

High density laser-driven target

DOEpatents

Lindl, John D.

1981-01-01

A high density target for implosion by laser energy composed of a central quantity of fuel surrounded by a high-Z pusher shell with a low-Z ablator-pusher shell spaced therefrom forming a region filled with low-density material.

INVESTIGATION OF INORGANIC PHOTOTROPIC MATERIALS AS A BI-OPTIC ELEMENT APPLICABLE IN HIGH DENSITY STORAGE COMPUTER MEMORIES

DTIC Science & Technology

A general valuation of the various types of phototropic (i.e., reversible, light induced, color producing) phenomenon is given regarding the...application of phototropic material to bioptic high density storage media for compu er memories. The inorganic ’’F’’ center type phototropic systems were

Impact fracture toughness evaluation for high-density polyethylene materials

NASA Astrophysics Data System (ADS)

Cherief, M. N. D.; Elmeguenni, M.; Benguediab, M.

2017-03-01

The impact fracture behavior of a high-density polyethylene (HDPE) material is investigated experimentally and theoretically. Single-edge notched bending (SENB) specimens are tested in experiments with three-point bending and in the Charpy impact tests. An energy model is proposed for evaluating the HDPE impact toughness, which provides a description of both brittle and ductile fracture.

Effective thermal conductivity determination for low-density insulating materials

NASA Technical Reports Server (NTRS)

Williams, S. D.; Curry, D. M.

1978-01-01

That nonlinear least squares can be used to determine effective thermal conductivity was demonstrated, and a method for assessing the relative error associated with these predicted values was provided. The differences between dynamic and static determination of effective thermal conductivity of low-density materials that transfer heat by a combination of conduction, convection, and radiation were discussed.

A Simple Method for Determination of the Density of Granular Materials

ERIC Educational Resources Information Center

Tsutsumanova, G. G.; Kirilov, K. M.; Russev, S. C.

2012-01-01

A simple experiment using low cost equipment for the determination of the density of granular materials, without immersing them in a liquid, is presented. It is based only on the ideal gas state equation, so it is a good experimental task for undergraduate and high school students. (Contains 2 tables and 5 figures.)

Dry chips versus green chips as furnish for medium-density fiberboard

Treesearch

Paul H. Short; George E. Woodson; Duane E. Lyon

1978-01-01

The fiber characteristics and the physical and mechanical properties of medium-density fiberboard (MDF), manufactured with pressure-refined fiber from green and partially dried raw material, were analyzed to determine if dry wood chips made a better furnish than green wood chips. Pressure-refining dry material produced coarser fiber than those obtained from green...

Dry chips versus green chips as furnish for medium-density fiberboard

Treesearch

P.H. Short; G.E. Woodson; D.E. Lyon

1978-01-01

The fiber characteristics and the physical and mechanical properties of medium-density fiberboard (MDF), manufactured with pressure-refined fiber from green and partially dried raw material, were analyzed to determine if dry wood chips made a better furnish than green wood chips. Pressure-refined dry material produced coarser fiber than those obtained from green...

Computational predictions of energy materials using density functional theory

NASA Astrophysics Data System (ADS)

Jain, Anubhav; Shin, Yongwoo; Persson, Kristin A.

2016-01-01

In the search for new functional materials, quantum mechanics is an exciting starting point. The fundamental laws that govern the behaviour of electrons have the possibility, at the other end of the scale, to predict the performance of a material for a targeted application. In some cases, this is achievable using density functional theory (DFT). In this Review, we highlight DFT studies predicting energy-related materials that were subsequently confirmed experimentally. The attributes and limitations of DFT for the computational design of materials for lithium-ion batteries, hydrogen production and storage materials, superconductors, photovoltaics and thermoelectric materials are discussed. In the future, we expect that the accuracy of DFT-based methods will continue to improve and that growth in computing power will enable millions of materials to be virtually screened for specific applications. Thus, these examples represent a first glimpse of what may become a routine and integral step in materials discovery.

High efficiency and non-Richardson thermionics in three dimensional Dirac materials

NASA Astrophysics Data System (ADS)

Huang, Sunchao; Sanderson, Matthew; Zhang, Yan; Zhang, Chao

2017-10-01

Three dimensional (3D) topological materials have a linear energy dispersion and exhibit many electronic properties superior to conventional materials such as fast response times, high mobility, and chiral transport. In this work, we demonstrate that 3D Dirac materials also have advantages over conventional semiconductors and graphene in thermionic applications. The low emission current suffered in graphene due to the vanishing density of states is enhanced by an increased group velocity in 3D Dirac materials. Furthermore, the thermal energy carried by electrons in 3D Dirac materials is twice of that in conventional materials with a parabolic electron energy dispersion. As a result, 3D Dirac materials have the best thermal efficiency or coefficient of performance when compared to conventional semiconductors and graphene. The generalized Richardson-Dushman law in 3D Dirac materials is derived. The law exhibits the interplay of the reduced density of states and enhanced emission velocity.

Study on HDPE Mixed with Sand as Backfilled Material on Retaining Structure

NASA Astrophysics Data System (ADS)

Talib, Z. A.

2018-04-01

The failure of the retaining wall is closely related to backfill material. Granular soils such as sand and gravel are most suitable backfill material because of its drainage properties. However two basic materials are quite heavy and contribute high amount of lateral loads. This study was to determine the effectiveness High Density Polyethylene (HDPE) as a backfill material. HDPE has a lighter weight compare to the sand. It makes HDPE has potential to be used as backfill material. The objective of this study is to identify the most effective percentage of HDPE to replace sand as a backfill material. The percentage of HDPE used in this study was 20%, 30%, 50%, 75% and also 100%. Testing involved in this study were sieve analysis test, constant head permeability test, direct shear test and relative density test. The result shows that the HDPE can be used as backfilled material and save the cost of backfill material

High-throughput density-functional perturbation theory phonons for inorganic materials

NASA Astrophysics Data System (ADS)

Petretto, Guido; Dwaraknath, Shyam; P. C. Miranda, Henrique; Winston, Donald; Giantomassi, Matteo; van Setten, Michiel J.; Gonze, Xavier; Persson, Kristin A.; Hautier, Geoffroy; Rignanese, Gian-Marco

2018-05-01

The knowledge of the vibrational properties of a material is of key importance to understand physical phenomena such as thermal conductivity, superconductivity, and ferroelectricity among others. However, detailed experimental phonon spectra are available only for a limited number of materials, which hinders the large-scale analysis of vibrational properties and their derived quantities. In this work, we perform ab initio calculations of the full phonon dispersion and vibrational density of states for 1521 semiconductor compounds in the harmonic approximation based on density functional perturbation theory. The data is collected along with derived dielectric and thermodynamic properties. We present the procedure used to obtain the results, the details of the provided database and a validation based on the comparison with experimental data.

Predicting materials for sustainable energy sources: The key role of density functional theory

NASA Astrophysics Data System (ADS)

Galli, Giulia

Climate change and the related need for sustainable energy sources replacing fossil fuels are pressing societal problems. The development of advanced materials is widely recognized as one of the key elements for new technologies that are required to achieve a sustainable environment and provide clean and adequate energy for our planet. We discuss the key role played by Density Functional Theory, and its implementations in high performance computer codes, in understanding, predicting and designing materials for energy applications.

Experimental Investigation of Stiffness Characteristics and Damping Properties of a Metallic Rubber Material

NASA Astrophysics Data System (ADS)

Lu, Ch. Zh.; Li, Jingyuan; Zhou, Bangyang; Li, Shuang

2017-09-01

The static stiffness and dynamic damping properties of a metallic rubber material (MR) were investigated, which exhibited a nonlinear deformation behavior. Its static stiffness is analyzed and discussed. The effects of structural parameters of MR and experimental conditions on its shock absorption capacity were examined by dynamic tests. Results revealed excellent elastic and damping properties of the material. Its stiffness increased with density, but decreased with thickness. The damping property of MR varied with its density, thickness, loading frequency, and amplitude.

Bacterial-cellulose-derived carbon nanofiber@MnO₂ and nitrogen-doped carbon nanofiber electrode materials: an asymmetric supercapacitor with high energy and power density.

PubMed

Chen, Li-Feng; Huang, Zhi-Hong; Liang, Hai-Wei; Guan, Qing-Fang; Yu, Shu-Hong

2013-09-14

A new kind of high-performance asymmetric supercapacitor is designed with pyrolyzed bacterial cellulose (p-BC)-coated MnO₂ as a positive electrode material and nitrogen-doped p-BC as a negative electrode material via an easy, efficient, large-scale, and green fabrication approach. The optimal asymmetric device possesses an excellent supercapacitive behavior with quite high energy and power density. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Computational Modeling of Causal Mechanisms of Blast Wave Induced Traumatic Brain Injury - A Potential Tool for Injury Prevention

DTIC Science & Technology

2009-10-01

detonation and expansion of the TNT explosive materials was described using the JWL (Jones-Wilkins-Lee) equation of state (EOS) along with a high...explosive material definition (Dobratz 1981). The JWL equation is described as: Where V= ρ0 (initial density of an explosive)/ρ (density of detonation...gas). E is specific internal energy. A, B, R1, R2, ω are JWL fitting parameters (Table 2). ρ0 Detonation velocity CJ pressure Material

Porous materials produced from incineration ash using thermal plasma technology.

PubMed

Yang, Sheng-Fu; Chiu, Wen-Tung; Wang, To-Mai; Chen, Ching-Ting; Tzeng, Chin-Ching

2014-06-01

This study presents a novel thermal plasma melting technique for neutralizing and recycling municipal solid waste incinerator (MSWI) ash residues. MSWI ash residues were converted into water-quenched vitrified slag using plasma vitrification, which is environmentally benign. Slag is adopted as a raw material in producing porous materials for architectural and decorative applications, eliminating the problem of its disposal. Porous materials are produced using water-quenched vitrified slag with Portland cement and foaming agent. The true density, bulk density, porosity and water absorption ratio of the foamed specimens are studied here by varying the size of the slag particles, the water-to-solid ratio, and the ratio of the weights of the core materials, including the water-quenched vitrified slag and cement. The thermal conductivity and flexural strength of porous panels are also determined. The experimental results show the bulk density and the porosity of the porous materials are 0.9-1.2 g cm(-3) and 50-60%, respectively, and the pore structure has a closed form. The thermal conductivity of the porous material is 0.1946 W m(-1) K(-1). Therefore, the slag composite materials are lightweight and thermal insulators having considerable potential for building applications. Copyright © 2013 Elsevier Ltd. All rights reserved.

Super Dielectric Material Based Capacitors: Punched Membrane/Gel

NASA Astrophysics Data System (ADS)

Petty, C. W.; Phillips, J.

2018-05-01

Extensive testing showed, as predicted, that punched membranes, filled with a gel containing aqueous salt solutions, behave as superdielectric materials (SDM). Punched membrane superdielectrics employed herein consisted of a commercial cellulose based membrane material, Celgard 16 μ thick, a material frequently used as a separator material in supercapacitors, into which macroscopic holes (ca. 2.5 mm) were punched with a laser cutter, and the holes subsequently filled with a gel-like material composed of fumed silica, NaCl and water. The gross dielectric constants measured, generally > 105, and the energy densities, > 40 J/cm3 during slow discharge, were in the range expected for superdielectric materials. The measured capacitance and energy density tracked the number of holes punched/area filled with the dielectric gel. Also, the observed power law decrease in all parameters including energy, power and capacitance, followed the same trends observed in other classes of SDM. Control studies included testing dielectrics composed of Celgard into which no holes were punched, but the SDM gel spread, also produced values consistent with the SDM model: no measurable capacitance using the standard protocol. Finally, the values measured suggest these materials rival the energy density of some common battery types at low discharge rates, and surpass the best commercial supercapacitors at low discharge rates.

Computational Study of Uniaxial Deformations in Silica Aerogel Using a Coarse-Grained Model.

PubMed

Ferreiro-Rangel, Carlos A; Gelb, Lev D

2015-07-09

Simulations of a flexible coarse-grained model are used to study silica aerogels. This model, introduced in a previous study (J. Phys. Chem. C 2007, 111, 15792), consists of spherical particles which interact through weak nonbonded forces and strong interparticle bonds that may form and break during the simulations. Small-deformation simulations are used to determine the elastic moduli of a wide range of material models, and large-deformation simulations are used to probe structural evolution and plastic deformation. Uniaxial deformation at constant transverse pressure is simulated using two methods: a hybrid Monte Carlo approach combining molecular dynamics for the motion of individual particles and stochastic moves for transverse stress equilibration, and isothermal molecular dynamics simulations at fixed Poisson ratio. Reasonable agreement on elastic moduli is obtained except at very low densities. The model aerogels exhibit Poisson ratios between 0.17 and 0.24, with higher-density gels clustered around 0.20, and Young's moduli that vary with aerogel density according to a power-law dependence with an exponent near 3.0. These results are in agreement with reported experimental values. The models are shown to satisfy the expected homogeneous isotropic linear-elastic relationship between bulk and Young's moduli at higher densities, but there are systematic deviations at the lowest densities. Simulations of large compressive and tensile strains indicate that these materials display a ductile-to-brittle transition as the density is increased, and that the tensile strength varies with density according to a power law, with an exponent in reasonable agreement with experiment. Auxetic behavior is observed at large tensile strains in some models. Finally, at maximum tensile stress very few broken bonds are found in the materials, in accord with the theory that only a small fraction of the material structure is actually load-bearing.

Thermo-mechanical characterization of silicone foams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rangaswamy, Partha; Smith, Nickolaus A.; Cady, Carl M.

Cellular solids such as elastomeric foams are used in many structural applications to absorb and dissipate energy, due to their light weight (low density) and high energy absorption capability. In this paper we will discuss foams derived from S5370, a silicone foam formulation developed by Dow Corning. In the application presented, the foam is consolidated into a cushion component of constant thickness but variable density. A mechanical material model developed by Lewis (2013), predicts material response, in part, as a function of relative density. To determine the required parameters for this model we have obtained the mechanical response in compressionmore » for ambient, cold and hot temperatures. The variable density cushion provided samples sufficient samples so that the effect of sample initial density on the mechanical response could be studied. The mechanical response data showed extreme sensitivity to relative density. We also observed at strains corresponding to 1 MPa a linear relationship between strain and initial density for all temperatures. Samples taken from parts with a history of thermal cycling demonstrated a stiffening response that was a function of temperature, with the trend of more stiffness as temperature increased above ambient. This observation is in agreement with the entropic effects on the thermo-mechanical behavior of silicone polymers. In this study, we present the experimental methods necessary for the development of a material model, the testing protocol, analysis of test data, and a discussion of load (stress) and gap (strain) as a function of sample initial densities and temperatures« less

Kapton charging characteristics: Effects of material thickness and electron-energy distribution

NASA Technical Reports Server (NTRS)

Williamson, W. S.; Dulgeroff, C. R.; Hymann, J.; Viswanathan, R.

1985-01-01

Charging characteristics of polyimide (Kapton) of varying thicknesses under irradiation by a very-low-curent-density electron beam, with the back surface of the sample grounded are reported. These charging characteristics are in good agreement with a simple analytical model which predicts that in thin samples at low current density, sample surface potential is limited by conduction leakage through the bulk material. The charging of Kapton in a low-current-density electron beam in which the beam energy was modulated to simulate Maxwellian and biMaxwellian distribution functions is measured.

Method for making a low density polyethylene waste form for safe disposal of low level radioactive material

DOEpatents

Colombo, P.; Kalb, P.D.

1984-06-05

In the method of the invention low density polyethylene pellets are mixed in a predetermined ratio with radioactive particulate material, then the mixture is fed through a screw-type extruder that melts the low density polyethylene under a predetermined pressure and temperature to form a homogeneous matrix that is extruded and separated into solid monolithic waste forms. The solid waste forms are adapted to be safely handled, stored for a short time, and safely disposed of in approved depositories.

Lunar Surface Material - Spacecraft Measurements of Density and Strength

NASA Technical Reports Server (NTRS)

Jaffe, L. D.

1969-01-01

The relation of the density of the lunar surface layer to depth is probably best determined from spacecraft measurements of the bearing capacity as a function of depth. A comparison of these values with laboratory measurements of the bearing capacity of low-cohesion particulate materials as a function of the percentage of solid indicates that the bulk density at the lunar surface is about 1.1 grams per cubic centimeter and that it increases nearly linearly to about 1.6 grams per cubic centimeter at a depth of 5 centimeters.

Materials Data on TiNi (SG:157) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-02-05

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

Materials Data on CdAu (SG:157) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-03-27

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

Materials Data on KP (SG:19) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

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

Materials Data on PdC (SG:216) by Materials Project

DOE Data Explorer

Kristin Persson

2016-09-21

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

Materials Data on PdC (SG:225) by Materials Project

DOE Data Explorer

Kristin Persson

2016-09-21

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

Materials Data on PuSe (SG:225) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-02-10

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

Materials Data on TiRe (SG:221) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-04-23

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

Materials Data on Ca (SG:139) by Materials Project

DOE Data Explorer

Kristin Persson

2015-01-27

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

Materials Data on Ca (SG:229) by Materials Project

DOE Data Explorer

Kristin Persson

2016-04-22

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

Materials Data on Ca (SG:221) by Materials Project

DOE Data Explorer

Kristin Persson

2015-02-09

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

Materials Data on Ca (SG:194) by Materials Project

DOE Data Explorer

Kristin Persson

2015-02-09

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

Materials Data on TiC (SG:225) by Materials Project

DOE Data Explorer

Kristin Persson

2016-02-05

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

Materials Data on PuB (SG:225) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2014-11-02

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

Materials Data on HoP (SG:225) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-02-05

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

Materials Data on HoP (SG:221) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-07-26

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

Materials Data on YSb2 (SG:21) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2017-04-07

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

Materials Data on TaN (SG:216) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-09-24

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

Materials Data on TaN (SG:221) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-09-25

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

Materials Data on KWO3 (SG:221) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2017-07-17

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

Materials Data on CaAs (SG:189) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-02-10

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

Materials Data on InN (SG:186) by Materials Project

DOE Data Explorer

Kristin Persson

2014-11-02

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

Materials Data on SnPd (SG:62) by Materials Project

DOE Data Explorer

Kristin Persson

2015-01-27

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

Materials Data on SrO (SG:225) by Materials Project

DOE Data Explorer

Kristin Persson

2014-11-02

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

Materials Data on DyTh (SG:221) by Materials Project

DOE Data Explorer

Kristin Persson

2014-11-02

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

Materials Data on In (SG:194) by Materials Project

DOE Data Explorer

Kristin Persson

2016-02-11

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

Materials Data on GdGe (SG:63) by Materials Project

DOE Data Explorer

Kristin Persson

2014-11-02

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

Materials Data on CrO (SG:225) by Materials Project

DOE Data Explorer

Kristin Persson

2014-11-02

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

Materials Data on MgPt (SG:198) by Materials Project

DOE Data Explorer

Kristin Persson

2015-01-27

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

Materials Data on USnPt (SG:216) by Materials Project

DOE Data Explorer

Kristin Persson

2015-03-19

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

Materials Data on Be (SG:136) by Materials Project

DOE Data Explorer

Kristin Persson

2016-09-17

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

Materials Data on Nd (SG:229) by Materials Project

DOE Data Explorer

Kristin Persson

2014-11-02

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

Materials Data on DyNi (SG:62) by Materials Project

DOE Data Explorer

Kristin Persson

2015-01-27

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

Materials Data on SbIr (SG:194) by Materials Project

DOE Data Explorer

Kristin Persson

2015-02-09

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

Materials Data on BaSe (SG:225) by Materials Project

DOE Data Explorer

Kristin Persson

2014-11-02

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

Materials Data on BaSe (SG:221) by Materials Project

DOE Data Explorer

Kristin Persson

2014-11-02

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

Materials Data on BPS4 (SG:23) by Materials Project

DOE Data Explorer

Kristin Persson

2014-11-02

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

Materials Data on GaN (SG:216) by Materials Project

DOE Data Explorer

Kristin Persson

2014-07-09

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

Materials Data on GaN (SG:225) by Materials Project

DOE Data Explorer

Kristin Persson

2014-11-02

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

Materials Data on GaN (SG:194) by Materials Project

DOE Data Explorer

Kristin Persson

2016-09-15

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

Materials Data on GaN (SG:186) by Materials Project

DOE Data Explorer

Kristin Persson

2014-07-09

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

Materials Data on TlBr (SG:225) by Materials Project

DOE Data Explorer

Kristin Persson

2014-07-09

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

Materials Data on TlBr (SG:221) by Materials Project

DOE Data Explorer

Kristin Persson

2014-11-02

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

Materials Data on TlBr (SG:63) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2014-07-09

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

Materials Data on P (SG:12) by Materials Project

DOE Data Explorer

Kristin Persson

2014-11-02

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

Materials Data on LuP (SG:225) by Materials Project

DOE Data Explorer

Kristin Persson

2014-11-02

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

Materials Data on P (SG:64) by Materials Project

DOE Data Explorer

Kristin Persson

2014-11-02

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

Materials Data on CoPSe (SG:61) by Materials Project

DOE Data Explorer

Kristin Persson

2014-11-02

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

Materials Data on P (SG:225) by Materials Project

DOE Data Explorer

Kristin Persson

2014-07-09

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

Materials Data on P (SG:0) by Materials Project

DOE Data Explorer

Kristin Persson

2016-02-11

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

Materials Data on P (SG:13) by Materials Project

DOE Data Explorer

Kristin Persson

2014-07-09

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

Materials Data on LuPPt (SG:187) by Materials Project

DOE Data Explorer

Kristin Persson

2014-11-02

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

Materials Data on NpP (SG:225) by Materials Project

DOE Data Explorer

Kristin Persson

2015-02-09

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

Materials Data on P (SG:74) by Materials Project

DOE Data Explorer

Kristin Persson

2016-02-10

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

Materials Data on P (SG:2) by Materials Project

DOE Data Explorer

Kristin Persson

2014-11-02

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

Materials Data on P (SG:221) by Materials Project

DOE Data Explorer

Kristin Persson

2014-07-09

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

Materials Data on FeP (SG:62) by Materials Project

DOE Data Explorer

Kristin Persson

2015-02-09

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

Materials Data on P (SG:166) by Materials Project

DOE Data Explorer

Kristin Persson

2015-02-09

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

Materials Data on CaPAu (SG:194) by Materials Project

DOE Data Explorer

Kristin Persson

2015-02-09

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

Materials Data on VO2 (SG:59) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2014-09-30

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

Materials Data on VO2 (SG:166) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2014-09-30

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

Materials Data on VO2 (SG:1) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2014-09-30

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

Materials Data on VO2 (SG:15) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2014-09-30

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

Materials Data on VO2 (SG:227) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2014-11-02

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

Materials Data on VO2 (SG:63) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2014-09-30

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

Materials Data on VO2 (SG:139) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-04-22

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

Materials Data on VO2 (SG:10) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-04-22

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

Materials Data on VO2 (SG:166) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-04-23

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

Materials Data on VO2 (SG:12) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-04-22

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

Materials Data on VO2 (SG:74) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2014-09-30

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

Materials Data on VO2 (SG:10) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-02-04

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

Materials Data on VO2 (SG:2) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-04-22

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

Materials Data on VO2 (SG:194) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2014-09-30

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

Materials Data on VO2 (SG:62) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2014-11-02

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

Materials Data on VO2 (SG:136) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2014-11-02

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

Materials Data on VO2 (SG:11) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2014-09-30

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

Materials Data on VO2 (SG:160) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2014-09-30

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

Materials Data on VO2 (SG:87) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2014-09-30

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

Materials Data on VO2 (SG:1) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-04-22

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

Materials Data on U (SG:136) by Materials Project

DOE Data Explorer

Kristin Persson

2016-02-05

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

Materials Data on U (SG:63) by Materials Project

DOE Data Explorer

Kristin Persson

2016-02-10

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

Materials Data on U (SG:229) by Materials Project

DOE Data Explorer

Kristin Persson

2015-02-09

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

Materials Data on U (SG:102) by Materials Project

DOE Data Explorer

Kristin Persson

2016-02-10

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

Materials Data on U (SG:225) by Materials Project

DOE Data Explorer

Kristin Persson

2016-09-18

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

Materials Data on CuS (SG:63) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-04-22

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

Materials Data on CuS (SG:194) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-04-22

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

Materials Data on CuS (SG:225) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2017-04-25

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

Materials Data on BiO (SG:160) by Materials Project

DOE Data Explorer

Kristin Persson

2014-11-02

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

Materials Data on VO2 (SG:14) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2017-04-14

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

Materials Data on NaSi (SG:15) by Materials Project

DOE Data Explorer

Kristin Persson

2014-11-02

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

Materials Data on VS2 (SG:2) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-02-04

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

Materials Data on CoMo (SG:221) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

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

Materials Data on SiS (SG:53) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

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

Materials Data on P (SG:53) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

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

Materials Data on B (SG:1) by Materials Project

DOE Data Explorer

Kristin Persson

2016-02-11

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

Materials Data on B (SG:134) by Materials Project

DOE Data Explorer

Kristin Persson

2014-07-09

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

Materials Data on B (SG:166) by Materials Project

DOE Data Explorer

Kristin Persson

2014-11-02

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

Materials Data on BNCl2 (SG:146) by Materials Project

DOE Data Explorer

Kristin Persson

2014-11-02

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

Materials Data on B (SG:134) by Materials Project

DOE Data Explorer

Kristin Persson

2016-02-10

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

Materials Data on BAs (SG:216) by Materials Project

DOE Data Explorer

Kristin Persson

2014-11-02

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

Materials Data on TiB (SG:216) by Materials Project

DOE Data Explorer

Kristin Persson

2014-11-02

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

Materials Data on B (SG:166) by Materials Project

DOE Data Explorer

Kristin Persson

2016-02-10

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

Materials Data on CoW (SG:221) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-09-15

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

Materials Data on Mg (SG:229) by Materials Project

DOE Data Explorer

Kristin Persson

2015-02-09

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

Materials Data on Mg (SG:194) by Materials Project

DOE Data Explorer

Kristin Persson

2016-02-11

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

Materials Data on RbS (SG:71) by Materials Project

DOE Data Explorer

Kristin Persson

2014-07-09

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

Materials Data on RbS (SG:189) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2014-07-09

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

Materials Data on CCl4 (SG:15) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-08-23

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

Materials Data on PH3 (SG:1) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2014-07-09

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

Materials Data on USb (SG:221) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2014-11-02

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

Materials Data on USb (SG:225) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-07-14

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

Materials Data on UN (SG:225) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-04-23

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

Materials Data on KSb2 (SG:12) by Materials Project

DOE Data Explorer

Kristin Persson

2014-11-02

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

Materials Data on KTlO (SG:12) by Materials Project

DOE Data Explorer

Kristin Persson

2014-11-02

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

Materials Data on ThC (SG:221) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

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

Materials Data on ThC (SG:225) by Materials Project

DOE Data Explorer

Kristin Persson

2015-02-09

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

Materials Data on IrN (SG:131) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-09-15

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

Materials Data on TiH (SG:131) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-02-11

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

Materials Data on PtO (SG:131) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-02-10

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

Materials Data on PdN (SG:131) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-05-24

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

Materials Data on OsN (SG:131) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-05-24

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

Materials Data on CuO (SG:131) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-04-22

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

Materials Data on PbO (SG:131) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-02-10

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

Materials Data on CrO (SG:131) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-04-22

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

Materials Data on ReN (SG:131) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-09-03

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

Materials Data on YCoC (SG:131) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-02-10

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

Materials Data on TcN (SG:131) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-05-23

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

Materials Data on ZrH (SG:131) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-02-10

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

Materials Data on USO (SG:129) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-04-22

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

Materials Data on AlSb (SG:63) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2017-04-28

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

Materials Data on LaSn (SG:63) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2017-04-07

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

Materials Data on CeRh (SG:63) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2017-04-07

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

Materials Data on AsS (SG:14) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-02-04

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

Materials Data on AsS (SG:1) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2014-07-09

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

Materials Data on AsS (SG:15) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2014-07-09

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

Materials Data on AsS (SG:14) by Materials Project

DOE Data Explorer

Kristin Persson

2014-07-09

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

Materials Data on K (SG:63) by Materials Project

DOE Data Explorer

Kristin Persson

2016-02-11

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

Materials Data on K (SG:221) by Materials Project

DOE Data Explorer

Kristin Persson

2016-05-19

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

Materials Data on K (SG:64) by Materials Project

DOE Data Explorer

Kristin Persson

2016-02-05

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

Materials Data on K (SG:229) by Materials Project

DOE Data Explorer

Kristin Persson

2016-02-10

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

Materials Data on K (SG:225) by Materials Project

DOE Data Explorer

Kristin Persson

2014-11-02

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

Materials Data on K (SG:194) by Materials Project

DOE Data Explorer

Kristin Persson

2016-02-05

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

Materials Data on K (SG:15) by Materials Project

DOE Data Explorer

Kristin Persson

2016-02-05

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

Materials Data on ScC (SG:216) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-09-23

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

Materials Data on ScGe (SG:216) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-09-23

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

Materials Data on ScSi (SG:216) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-09-23

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

Materials Data on ScSn (SG:216) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-09-23

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

Materials Data on Sb (SG:221) by Materials Project

DOE Data Explorer

Kristin Persson

2015-02-09

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

Materials Data on S (SG:14) by Materials Project

DOE Data Explorer

Kristin Persson

2014-07-09

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

Materials Data on S (SG:70) by Materials Project

DOE Data Explorer

Kristin Persson

2014-07-09

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

Materials Data on S (SG:58) by Materials Project

DOE Data Explorer

Kristin Persson

2014-07-09

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

Materials Data on S (SG:221) by Materials Project

DOE Data Explorer

Kristin Persson

2014-11-02

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

Materials Data on S (SG:19) by Materials Project

DOE Data Explorer

Kristin Persson

2014-07-09

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

Materials Data on S (SG:13) by Materials Project

DOE Data Explorer

Kristin Persson

2014-07-09

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

Materials Data on S (SG:148) by Materials Project

DOE Data Explorer

Kristin Persson

2014-07-09

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

Materials Data on S (SG:2) by Materials Project

DOE Data Explorer

Kristin Persson

2014-07-09

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

Materials Data on S (SG:15) by Materials Project

DOE Data Explorer

Kristin Persson

2014-07-09

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

Materials Data on S (SG:29) by Materials Project

DOE Data Explorer

Kristin Persson

2014-07-09

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

Materials Data on S (SG:15) by Materials Project

DOE Data Explorer

Kristin Persson

2016-02-04

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

Materials Data on S (SG:4) by Materials Project

DOE Data Explorer

Kristin Persson

2016-02-04

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

Materials Data on S (SG:99) by Materials Project

DOE Data Explorer

Kristin Persson

2016-04-23

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

Materials Data on S (SG:225) by Materials Project

DOE Data Explorer

Kristin Persson

2016-02-10

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

Materials Data on S (SG:154) by Materials Project

DOE Data Explorer

Kristin Persson

2014-07-09

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

Materials Data on S (SG:14) by Materials Project

DOE Data Explorer

Kristin Persson

2016-07-14

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

Materials Data on S (SG:143) by Materials Project

DOE Data Explorer

Kristin Persson

2016-02-11

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

Materials Data on S (SG:143) by Materials Project

DOE Data Explorer

Kristin Persson

2014-07-09

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

Materials Data on S (SG:60) by Materials Project

DOE Data Explorer

Kristin Persson

2014-07-09

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

Low Density Materials

DTIC Science & Technology

2012-03-09

materials structures across scales for design of engineered systems ODISSEI: Origami Design for Integration of Self-assembling Systems for...AGENCIES Origami Engineering US-India Tunable Materials Forum US-AFRICA Initiative Reliance 21 Board Materials and Processing COI 29 DISTRIBUTION A

Materials Data on HoSe (SG:225) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

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

Materials Data on O2 (SG:69) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2014-07-09

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

Materials Data on O2 (SG:166) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2014-07-09

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

Materials Data on As (SG:166) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2015-01-27

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

Materials Data on N2 (SG:194) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2014-11-02

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

Materials Data on CdC (SG:216) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-09-11

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

Materials Data on CdC (SG:225) by Materials Project

DOE Data Explorer

Kristin Persson

2016-09-11

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

Materials Data on CdIBr (SG:160) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2017-05-05

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

Materials Data on CSNOF5 (SG:2) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-03-28

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

Materials Data on CSNF5 (SG:62) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-03-28

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

Materials Data on YP (SG:225) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

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

Materials Data on LaAs (SG:225) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

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

Materials Data on YP (SG:221) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

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

Materials Data on LaP (SG:225) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

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

Materials Data on YAs (SG:221) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

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

Materials Data on YAs (SG:225) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

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

Materials Data on ZrRh (SG:51) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

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

Materials Data on HfIr (SG:51) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

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

Materials Data on VPt (SG:51) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

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

Materials Data on TiMo (SG:74) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-09-03

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

Materials Data on ZrC (SG:216) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-09-25

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

Materials Data on ZrC (SG:225) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2015-01-27

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

Materials Data on ZrC (SG:194) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-12-23

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

Materials Data on ZrC (SG:221) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-09-25

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

Materials Data on V (SG:225) by Materials Project

DOE Data Explorer

Kristin Persson

2016-04-23

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

Materials Data on V (SG:229) by Materials Project

DOE Data Explorer

Kristin Persson

2014-11-02

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

Materials Data on ErSF (SG:129) by Materials Project

DOE Data Explorer

Kristin Persson

2014-11-02

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

Materials Data on F (SG:64) by Materials Project

DOE Data Explorer

Kristin Persson

2014-07-09

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

Materials Data on CuF (SG:216) by Materials Project

DOE Data Explorer

Kristin Persson

2014-11-02

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

Materials Data on LiF (SG:225) by Materials Project

DOE Data Explorer

Kristin Persson

2014-11-02

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

Materials Data on TbSF (SG:129) by Materials Project

DOE Data Explorer

Kristin Persson

2014-11-02

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

Materials Data on YSF (SG:129) by Materials Project

DOE Data Explorer

Kristin Persson

2014-11-02

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

Materials Data on CF4 (SG:15) by Materials Project

DOE Data Explorer

Kristin Persson

2014-11-02

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

Materials Data on YOF (SG:129) by Materials Project

DOE Data Explorer

Kristin Persson

2014-11-02

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

Materials Data on HoSF (SG:129) by Materials Project

DOE Data Explorer

Kristin Persson

2014-11-02

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

Materials Data on RbF (SG:225) by Materials Project

DOE Data Explorer

Kristin Persson

2014-11-02

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

Materials Data on Y (SG:225) by Materials Project

DOE Data Explorer

Kristin Persson

2016-04-23

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

Materials Data on Y (SG:194) by Materials Project

DOE Data Explorer

Kristin Persson

2015-02-09

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

Materials Data on SO2 (SG:41) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-02-04

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

Materials Data on NaNO (SG:14) by Materials Project

DOE Data Explorer

Kristin Persson

2014-07-09

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

Materials Data on LaS (SG:221) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2016-09-19

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

Materials Data on VB2 (SG:191) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2014-11-02

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

Materials Data on UTe3 (SG:63) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

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

Materials Data on Rb (SG:70) by Materials Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristin Persson

2017-04-07

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

Materials Data on C (SG:166) by Materials Project

DOE Data Explorer

Kristin Persson

2014-11-02

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

Materials Data on C (SG:12) by Materials Project

DOE Data Explorer

Kristin Persson

2016-04-23

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

Materials Data on C (SG:58) by Materials Project

DOE Data Explorer

Kristin Persson

2014-07-09

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

Materials Data on C (SG:63) by Materials Project

DOE Data Explorer

Kristin Persson

2016-02-04

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

Materials Data on C (SG:227) by Materials Project

DOE Data Explorer

Kristin Persson

2014-07-09

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

Materials Data on C (SG:166) by Materials Project

DOE Data Explorer

Kristin Persson

2014-07-09

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

Materials Data on C (SG:65) by Materials Project

DOE Data Explorer

Kristin Persson

2016-02-05

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

Materials Data on C (SG:221) by Materials Project

DOE Data Explorer

Kristin Persson

2016-05-19

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

Materials Data on C (SG:194) by Materials Project

DOE Data Explorer

Kristin Persson

2014-07-09

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

Materials Data on C (SG:214) by Materials Project

DOE Data Explorer

Kristin Persson

2017-04-07

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

Materials Data on C (SG:65) by Materials Project

DOE Data Explorer

Kristin Persson

2014-07-09

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

Materials Data on C (SG:166) by Materials Project

DOE Data Explorer

Kristin Persson

2016-02-05

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

Materials Data on C (SG:67) by Materials Project

DOE Data Explorer

Kristin Persson

2014-07-09

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

Materials Data on C (SG:194) by Materials Project

DOE Data Explorer

Kristin Persson

2016-04-20

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

Materials Data on C (SG:0) by Materials Project

DOE Data Explorer

Kristin Persson

2014-07-09

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

Materials Data on C (SG:71) by Materials Project

DOE Data Explorer

Kristin Persson

2016-02-05

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

Materials Data on C (SG:65) by Materials Project

DOE Data Explorer

Kristin Persson

2016-09-16

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

Materials Data on C (SG:191) by Materials Project

DOE Data Explorer

Kristin Persson

2016-02-11

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

Materials Data on C (SG:166) by Materials Project

DOE Data Explorer

Kristin Persson

2016-05-16

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

Materials Data on C (SG:164) by Materials Project

DOE Data Explorer

Kristin Persson

2016-09-03

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

Materials Data on C (SG:202) by Materials Project

DOE Data Explorer

Kristin Persson

2014-07-09

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

Materials Data on C (SG:69) by Materials Project

DOE Data Explorer

Kristin Persson

2016-07-22

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

Materials Data on C (SG:229) by Materials Project

DOE Data Explorer

Kristin Persson

2014-07-09

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

Materials Data on C (SG:191) by Materials Project

DOE Data Explorer

Kristin Persson

2017-07-14

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

Materials Data on C (SG:67) by Materials Project

DOE Data Explorer

Kristin Persson

2016-02-11

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

Materials Data on C (SG:139) by Materials Project

DOE Data Explorer

Kristin Persson

2016-09-17

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

Materials Data on C (SG:206) by Materials Project

DOE Data Explorer

Kristin Persson

2014-11-02

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