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1

Development of High Energy Density Lithium-Sulfur Cells  

Broader source: Energy.gov [DOE]

2013 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting

2

Fundamental Studies of Lithium-Sulfur Cell Chemistry  

Broader source: Energy.gov (indexed) [DOE]

Studies of Lithium-Sulfur Cell Chemistry PI: Nitash Balsara LBNL June 17, 2014 Project ID ESS224 This presentation does not contain any proprietary, confidential, or otherwise...

3

Vehicle Technologies Office Merit Review 2014: Development of High Energy Density Lithium-Sulfur Cells  

Broader source: Energy.gov [DOE]

Presentation given by The Pennsylvania State University at 2014 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about development...

4

A Mathematical Model for a LithiumSulfur Cell Karthikeyan Kumaresan,a,  

E-Print Network [OSTI]

S8 l is reduced to S2- in steps. For example, S8 l is reduced to S8 2- , then to S6 2- , S4 2- , S2,4 Figure 1 presents a typical experimental discharge profile at a C/50 rate C = 2.5 Ah . The lithium/sulfur Development The schematic of the lithium/sulfur cell modeled in this work is shown in Fig. 2. The cell is made

5

Additives and Cathode Materials for High-Energy Lithium Sulfur...  

Broader source: Energy.gov (indexed) [DOE]

Additives and Cathode Materials for High-Energy Lithium Sulfur Batteries Additives and Cathode Materials for High-Energy Lithium Sulfur Batteries 2013 DOE Hydrogen and Fuel Cells...

6

Development of High Energy Density Lithium-Sulfur Cells  

Broader source: Energy.gov (indexed) [DOE]

for increased sulfur loading Cathode Anode Investigatingoptimizing Li and Si composite anodes Exploring polymer electrolytes Electrolyte Determining new...

7

Development of High Energy Density Lithium-Sulfur Cells  

Broader source: Energy.gov (indexed) [DOE]

* Cycle and calendar life * Abuse tolerance 44% completed Partners * EC Power * Johnson Controls * Argonne National Lab Budget * FY 2012: 2,166,675 *DOE share:1,524,373...

8

Vehicle Technologies Office Merit Review 2014: Fundamental Studies of Lithium-Sulfur Cell Chemistry  

Broader source: Energy.gov [DOE]

Presentation given by Lawrence Berkley National Laboratory at 2014 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about...

9

Manipulating the Surface Reactions in Lithium Sulfur Batteries...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Manipulating the Surface Reactions in Lithium Sulfur Batteries Using Hybrid Anode Structures. Manipulating the Surface Reactions in Lithium Sulfur Batteries Using Hybrid Anode...

10

Development of High Energy Density Lithium-Sulfur Cells | Department of  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-UpHeat Pump Models |Conduct, Parent Companya newHomogeneous ChargeMaterialsEnergy

11

Manipulating the Surface Reactions in Lithium Sulfur Batteries Using Hybrid Anode Structures  

SciTech Connect (OSTI)

Lithium-sulfur (Li-S) batteries have recently attracted extensive attention due to the high theoretical energy density and potential low cost. Even so, significant challenges prevent widespread adoption, including continuous dissolution and consumption of active sulfur during cycling. Here we present a fundamentally new design using electrically connected graphite and lithium metal as a hybrid anode to control undesirable surface reactions on the anode. The lithiated graphite placed in front of the lithium metal functions as an artificial self-regulated solid electrolyte interface (SEI) layer to actively control the electrochemical reaction while minimizing the deleterious side reactions on the surface and bulk lithium metal. Continuous corrosion and contamination of lithium anode by dissolved polysulfides is largely mitigated. Excellent electrochemical performance has been observed. Li-S cell incorporating the hybrid design retain a capacity of more than 800 mAh g-1 for 400 cycles, corresponding to only 11% fade and a Coulombic efficiency above 99%. This simple hybrid concept may also provide new lessons for protecting metal anodes in other energy storage devices.

Huang, Cheng; Xiao, Jie; Shao, Yuyan; Zheng, Jianming; Bennett, Wendy D.; Lu, Dongping; Saraf, Laxmikant V.; Engelhard, Mark H.; Ji, Liwen; Zhang, Jiguang; Li, Xiaolin; Graff, Gordon L.; Liu, Jun

2014-01-09T23:59:59.000Z

12

Amphiphilic Surface Modification of Hollow Carbon Nanofibers for Improved Cycle Life of Lithium Sulfur Batteries  

E-Print Network [OSTI]

lithium sulfur batteries, due to their high specific energy and relatively low cost. Despite recent progress in addressing the various problems of sulfur cathodes, lithium sulfur batteries still exhibit at C/2. KEYWORDS: Lithium sulfur batteries; energy storage; surface modification Increasing the energy

Cui, Yi

13

Controlled Nucleation and Growth Process of Li2S2/Li2S in Lithium-Sulfur Batteries  

SciTech Connect (OSTI)

Lithium-sulfur battery is a promising next-generation energy storage system because of its potentially three to five times higher energy density than that of traditional lithium ion batteries. However, the dissolution and precipitation of soluble polysulfides during cycling initiate a series of key-chain reactions that significantly shorten battery life. Herein, we demonstrate that through a simple but effective strategy, significantly improved cycling performance is achieved for high sulfur loading electrodes through controlling the nucleation and precipitation of polysulfieds on the electrode surface. More than 400 or 760 stable cycling are successfully displayed in the cells with locked discharge capacity of 625 mAh g-1 or 500 mAh g-1, respectively. The nucleation and growth process of dissolved polysulfides has been electrochemically altered to confine the thickness of discharge products passivated on the cathode surface, increasing the utilization rate of sulfur while avoiding severe morphology changes on the electrode. More importantly, the exposure of new lithium metal surface to the S-containing electrolyte is also greatly reduced through this strategy, largely minimizing the anode corrosion caused by polysulfides. This work interlocks the electrode morphologies and its evolution with electrochemical interference to modulate cell performances by using Li-S system as a platform, providing different but critical directions for this community.

Zheng, Jianming; Gu, Meng; Wang, Chong M.; Zuo, Pengjian; Koech, Phillip K.; Zhang, Jiguang; Liu, Jun; Xiao, Jie

2013-09-20T23:59:59.000Z

14

In Operando X-ray Diffraction and Transmission X-ray Microscopy of Lithium Sulfur Batteries  

E-Print Network [OSTI]

In Operando X-ray Diffraction and Transmission X-ray Microscopy of Lithium Sulfur Batteries Johanna Information ABSTRACT: Rechargeable lithium-sulfur (Li-S) batteries hold great potential for high of these batteries for commercial use. The two primary obstacles are the solubility of long chain lithium

Cui, Yi

15

Nanotechnology Alert. Nanofountain for Treatment of Cancer; Nanocomposites To Improve Computers' Life Span; Lithium Sulfur Batteries Using Nanocarbon  

E-Print Network [OSTI]

' Life Span; Lithium Sulfur Batteries Using Nanocarbon Electrodes This issue profiles a nanofountain, and lithium sulfur batteries that use nanocarbon electrodes. Deliverable Type: Technical Insights Date OF CANCER 3. NANOCOMPOSITES TO IMPROVE COMPUTERS LIFE SPAN 4. LITHIUM SULFUR BATTERIES USING NANOCARBON

Espinosa, Horacio D.

16

A Lithium Superionic Sulfide Cathode for Lithium-Sulfur Batteries  

SciTech Connect (OSTI)

This work presents a facile synthesis approach for core-shell structured Li2S nanoparticles, which have Li2S as the core and Li3PS4 as the shell. This material functions as lithium superionic sulfide (LSS) cathode for long-lasting, energy-efficient lithium-sulfur (Li-S) batteries. The LSS has an ionic conductivity of 10-7 S cm-1 at 25 oC, which is 6 orders of magnitude higher than that of bulk Li2S (~10-13 S cm-1). The high lithium-ion conductivity of LSS imparts an excellent cycling performance to all-solid Li-S batteries, which also promises safe cycling of high-energy batteries with metallic lithium anodes.

Lin, Zhan [ORNL] [ORNL; Liu, Zengcai [ORNL] [ORNL; Dudney, Nancy J [ORNL] [ORNL; Liang, Chengdu [ORNL] [ORNL

2013-01-01T23:59:59.000Z

17

Formation of Large Polysulfide Complexes during the Lithium-Sulfur Battery Discharge  

SciTech Connect (OSTI)

Sulfur cathodes have much larger capacities than transition-metal-oxide cathodes used in commercial lithium-ion batteries but suffer from unsatisfactory capacity retention and long-term cyclability. Capacity degradation originates from soluble lithium polysulfides gradually diffusing into the electrolyte. Understanding of the formation and dynamics of soluble polysulfides during the discharging process at the atomic level remains elusive, which limits further development of lithium-sulfur (Li-S) batteries. Here we report first-principles molecular dynamics simulations and density functional calculations, through which the discharging products of Li-S batteries are studied. We find that, in addition to simple Li2Sn (1 n 8) clusters generated from single cyclooctasulfur (S8) rings, large Li-S clusters form by collectively coupling several different rings to minimize the total energy. At high lithium concentration, a Li-S network forms at the sulfur surfaces. The results can explain the formation of the soluble Li-S complex, such as Li2S8, Li2S6, and Li2S4, and the insoluble Li2S2 and Li2S structures. In addition, we show that the presence of oxygen impurities in graphene, particularly oxygen atoms bonded to vacancies and edges, may stabilize the lithium polysulfides that may otherwise diffuse into the electrolyte.

Wang, Bin [Vanderbilt University, Nashville; Alhassan, Saeed M. [The Petroleum Institute; Pantelides, Sokrates T [ORNL

2014-01-01T23:59:59.000Z

18

Development of bulk-type all-solid-state lithium-sulfur battery using LiBH{sub 4} electrolyte  

SciTech Connect (OSTI)

Stable battery operation of a bulk-type all-solid-state lithium-sulfur battery was demonstrated by using a LiBH{sub 4} electrolyte. The electrochemical activity of insulating elemental sulfur as the positive electrode was enhanced by the mutual dispersion of elemental sulfur and carbon in the composite powders. Subsequently, a tight interface between the sulfur-carbon composite and the LiBH{sub 4} powders was manifested only by cold-pressing owing to the highly deformable nature of the LiBH{sub 4} electrolyte. The high reducing ability of LiBH{sub 4} allows using the use of a Li negative electrode that enhances the energy density. The results demonstrate the interface modification of insulating sulfur and the architecture of an all-solid-state Li-S battery configuration with high energy density.

Unemoto, Atsushi, E-mail: unemoto@imr.tohoku.ac.jp; Ikeshoji, Tamio [WPI-Advanced Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Yasaku, Syun; Matsuo, Motoaki [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Nogami, Genki; Tazawa, Masaru; Taniguchi, Mitsugu [Mitsubishi Gas Chemicals Co., Ltd., 182 Tayuhama Shinwari, Kita-ku, Niigata 950-3112 (Japan); Orimo, Shin-ichi [WPI-Advanced Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan)

2014-08-25T23:59:59.000Z

19

Vehicle Technologies Office Merit Review 2014: Development of...  

Broader source: Energy.gov (indexed) [DOE]

of High Energy Density Lithium-Sulfur Cells Vehicle Technologies Office Merit Review 2014: Development of High Energy Density Lithium-Sulfur Cells Presentation given by...

20

Graphene-sulfur nanocomposites for rechargeable lithium-sulfur battery electrodes  

SciTech Connect (OSTI)

Rechargeable lithium-sulfur batteries having a cathode that includes a graphene-sulfur nanocomposite can exhibit improved characteristics. The graphene-sulfur nanocomposite can be characterized by graphene sheets with particles of sulfur adsorbed to the graphene sheets. The sulfur particles have an average diameter less than 50 nm..

Liu, Jun; Lemmon, John P; Yang, Zhenguo; Cao, Yuiliang; Li, Xiaolin

2014-06-17T23:59:59.000Z

Note: This page contains sample records for the topic "density lithium-sulfur cells" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Additives and Cathode Materials for High-Energy Lithium Sulfur...  

Broader source: Energy.gov (indexed) [DOE]

of long cycle-life in half cells and expand the synthesis of sulfurcarbon composite materials of various sulfur loadings 2. Compare the performance for different...

22

Lithium Polysulfidophosphates: A Family of Lithium-Conducting Sulfur-Rich Compounds for Lithium-Sulfur Batteries  

SciTech Connect (OSTI)

Given the great potential for improving the energy density of state-of-the-art lithium-ion batteries by a factor of 5, a breakthrough in lithium-sulfur (Li-S) batteries will have a dramatic impact in a broad scope of energy related fields. Conventional Li-S batteries that use liquid electrolytes are intrinsically short-lived with low energy efficiency. The challenges stem from the poor electronic and ionic conductivities of elemental sulfur and its discharge products. We report herein lithium polysulfidophosphates (LPSP), a family of sulfur-rich compounds, as the enabler of long-lasting and energy-efficient Li-S batteries. LPSP have ionic conductivities of 3.0 10-5 S cm-1 at 25 oC, which is 8 orders of magnitude higher than that of Li2S (~10-13 S cm-1). The high Li-ion conductivity of LPSP is the salient characteristic of these compounds that impart the excellent cycling performance to Li-S batteries. In addition, the batteries are configured in an all-solid state that promises the safe cycling of high-energy batteries with metallic lithium anodes.

Lin, Zhan [ORNL] [ORNL; Liu, Zengcai [ORNL] [ORNL; Fu, Wujun [ORNL] [ORNL; Dudney, Nancy J [ORNL] [ORNL; Liang, Chengdu [ORNL] [ORNL

2013-01-01T23:59:59.000Z

23

How to Obtain Reproducible Results for Lithium Sulfur Batteries  

SciTech Connect (OSTI)

The basic requirements for getting reliable Li-S battery data have been discussed in this work. Unlike Li-ion batteries, electrolyte-rich environment significantly affects the cycling stability of Li-S batteries prepared and tested under the same conditions. The reason has been assigned to the different concentrations of polysulfide-containing electrolytes in the cells, which have profound influences on both sulfur cathode and lithium anode. At optimized S/E ratio of 50 g L-1, a good balance among electrolyte viscosity, wetting ability, diffusion rate dissolved polysulfide and nucleation/growth of short-chain Li2S/Li2S2 has been built along with largely reduced contamination on the lithium anode side. Accordingly, good cyclability, high reversible capacity and Coulombic efficiency are achieved in Li-S cell with controlled S/E ratio without any additive. Other factors such as sulfur content in the composite and sulfur loading on the electrode also need careful concern in Li-S system in order to generate reproducible results and gauge the various methods used to improve Li-S battery technology.

Zheng, Jianming; Lu, Dongping; Gu, Meng; Wang, Chong M.; Zhang, Jiguang; Liu, Jun; Xiao, Jie

2013-01-01T23:59:59.000Z

24

Lithium / Sulfur Cells with Long Cycle Life and High Specific Energy -  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: VegetationEquipment Surfaces and Interfaces Sample6, 2011Liisa O'NeillFuels MarketLisa L.LifeEnergy

25

Sulfur-Graphene Oxide Nanocomposite Cathodes for Lithium/Sulfur Cells -  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security AdministrationcontrollerNanocrystalline Gallium Oxide

26

Strong Sulfur Binding with Conducting Magneli-Phase TinO2n-1 Nanomaterials for Improving Lithium-Sulfur Batteries  

E-Print Network [OSTI]

will go through a series of soluble intermediate higher-order polysulfides (Li2S8, Li2S6, and Li2S4 of Li2S2, Li2S, and sulfur.6-8 In order to solve these challenges, there have been recent developmentsStrong Sulfur Binding with Conducting Magneli-Phase TinO2n-1 Nanomaterials for Improving Lithium-Sulfur

Cui, Yi

27

Additives and Cathode Materials for High-Energy Lithium Sulfur Batteries  

Broader source: Energy.gov [DOE]

2013 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting

28

Lithium-sulfur batteries based on nitrogen-doped carbon and ionic liquid electrolyte  

SciTech Connect (OSTI)

Nitrogen-doped mesoporous carbon (NC) and sulfur were used to prepare an NC/S composite cathode, which was evaluated in an ionic liquid electrolyte of 0.5 M lithium bis(trifluoromethane sulfonyl)imide (LiTFSI) in methylpropylpyrrolidinium bis(trifluoromethane sulfonyl)imide (MPPY.TFSI) by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and cycle testing. To facilitate the comparison, a C/S composite based on activated carbon (AC) without nitrogen doping was also fabricated under the same conditions as those for the NC/S composite. Compared with the AC/S composite, the NC/S composite showed enhanced activity toward sulfur reduction, as evidenced by the early onset sulfur reduction potential, higher redox current density in the CV test, and faster charge transfer kinetics as indicated by EIS measurement. At room temperature under a current density of 84 mA g-1 (C/20), the battery based on the NC/S composite exhibited higher discharge potential and an initial capacity of 1420 mAh g-1 whereas that based on the AC/S composite showed lower discharge potential and an initial capacity of 1120 mAh g-1. Both batteries showed similar capacity fading with cycling due to the intrinsic polysulfide solubility and the polysulfide shuttle mechanism; the capacity fading can be improved by further modification of the cathode.

Sun, Xiao-Guang [ORNL; Wang, Xiqing [ORNL; Mayes, Richard T [ORNL; Dai, Sheng [ORNL

2012-01-01T23:59:59.000Z

29

Ionic Liquid-Enhanced Solid State Electrolyte Interface (SEI) for Lithium Sulfur Batteries  

SciTech Connect (OSTI)

Li-S battery is a complicated system with many challenges existing before its final market penetration. While most of the reported work for Li-S batteries is focused on the cathode design, we demonstrate in this work that the anode consumption accelerated by corrosive polysulfide solution also critically determines the Li-S cell performance. To validate this hypothesis, ionic liquid (IL) N-methyl-N-butylpyrrolidinium bis(trifluoromethylsulfonyl)imide (Py14TFSI) has been employed to modify the properties of SEI layer formed on Li metal surface in Li-S batteries. It is found that the IL-enhanced passivation film on the lithium anode surface exhibits much different morphology and chemical compositions, effectively protecting lithium metal from continuous attack by soluble polysulfides. Therefore, both cell impedance and the irreversible consumption of polysulfides on lithium metal are reduced. As a result, the Coulombic efficiency and the cycling stability of Li-S batteries have been greatly improved. After 120 cycles, Li-S battery cycled in the electrolyte containing IL demonstrates a high capacity retention of 94.3% at 0.1 C rate. These results unveil another important failure mechanism for Li-S batteries and shin the light on the new approaches to improve Li-S battery performances.

Zheng, Jianming; Gu, Meng; Chen, Honghao; Meduri, Praveen; Engelhard, Mark H.; Zhang, Jiguang; Liu, Jun; Xiao, Jie

2013-05-16T23:59:59.000Z

30

High power density solid oxide fuel cells  

DOE Patents [OSTI]

A method for producing ultra-high power density solid oxide fuel cells (SOFCs). The method involves the formation of a multilayer structure cells wherein a buffer layer of doped-ceria is deposited intermediate a zirconia electrolyte and a cobalt iron based electrode using a colloidal spray deposition (CSD) technique. For example, a cobalt iron based cathode composed of (La,Sr)(Co,Fe)O (LSCF) may be deposited on a zirconia electrolyte via a buffer layer of doped-ceria deposited by the CSD technique. The thus formed SOFC have a power density of 1400 mW/cm.sup.2 at 600.degree. C. and 900 mW/cm.sup.2 at 700.degree. C. which constitutes a 2-3 times increased in power density over conventionally produced SOFCs.

Pham, Ai Quoc; Glass, Robert S.

2004-10-12T23:59:59.000Z

31

Quantitative Chromatographic Determination of Dissolved Elemental Sulfur in the Non-aqueous Electrolyte for Lithium-Sulfur Batteries  

DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

A fast and reliable analytical method is reported for the quantitative determination of dissolved elemental sulfur in non-aqueous electrolytes for Li-S batteries. By using high performance liquid chromatography with a UV detector, the solubility of S in 12 different pure solvents and in 22 different electrolytes was determined. It was found that the solubility of elemental sulfur is dependent on the Lewis basicity, the polarity of solvents and the salt concentration in the electrolytes. In addition, the S content in the electrolyte recovered from a discharged Li-S battery was successfully determined by the proposed HPLC/UV method. Thus, the feasibility of the method to the online analysis for a Li-S battery is demonstrated. Interestingly, the S was found super-saturated in the electrolyte recovered from a discharged Li-S cell.

Zheng, Dong [Univ. of Massachusetts, Boston, MA (United States). Dept. of Chemistry; Yang, Xiao-Qing [Brookhaven National Laboratory (BNL), Upton, NY (United States). Chemistry Dept.; Zhang, Xuran [Wuhan Univ. of Technology, Hubei (China); Dept. of Chemistry; Li, Chao [Univ. of Massachusetts, Boston, MA (United States). Dept. of Chemistry; McKinnon, Meaghan E. [Univ. of Massachusetts, Boston, MA (United States). Dept. of Chemistry; Sadok, Rachel G. [Univ. of Massachusetts, Boston, MA (United States). Dept. of Chemistry; Qu, Deyu [Wuhan Univ. of Technology, Hubei (China); Dept. of Chemistry; Yu, Xiqian [Brookhaven National Laboratory (BNL), Upton, NY (United States). Chemistry Dept.; Lee, Hung-Sui [Brookhaven National Laboratory (BNL), Upton, NY (United States). Chemistry Dept.; Qu, Deyang [Univ. of Massachusetts, Boston, MA (United States). Dept. of Chemistry

2014-11-01T23:59:59.000Z

32

Vehicle Technologies Office Merit Review 2014: Fundamental Studies...  

Broader source: Energy.gov (indexed) [DOE]

Fundamental Studies of Lithium-Sulfur Cell Chemistry Vehicle Technologies Office Merit Review 2014: Fundamental Studies of Lithium-Sulfur Cell Chemistry Presentation given by...

33

Effect of electrode configuration and electronic conductivity on current density distribution measurements in PEM fuel cells  

E-Print Network [OSTI]

EFFECT OF ELECTRODE CONFIGURATION AND ELECTRONIC CONDUCTIVITY ON CURRENT DENSITY DISTRIBUTION MEASUREMENTS IN PEM FUEL CELLS by Dilip Natarajan and Trung Van Nguyen* Department of Chemical and Petroleum Engineering University of Kansas... words: PEM fuel cells, conventional gas distributor, current density distribution, segmented electrode, mathematical modeling * Author to whom correspondence should be addressed ABSTRACT Current density and potential distribution measurements...

Natarajan, Dilip; Nguyen, Trung Van

2004-09-03T23:59:59.000Z

34

High Energy Density Li-ion Cells for EVs Based on Novel, High...  

Broader source: Energy.gov (indexed) [DOE]

Storage Systems Vehicle Technologies Annual Merit Review 6182014 1 High Energy Density Li-ion Cells for EV's Based on Novel, High Voltage Cathode Material Systems Keith D. Kepler...

35

PARTICLE-IN-CELL SIMULATIONS OF LOWER-DENSITY CM-SCALE CAPILLARY CHANNELS  

E-Print Network [OSTI]

PARTICLE-IN-CELL SIMULATIONS OF LOWER-DENSITY CM-SCALE CAPILLARY CHANNELS£ P. MessmerÝ , D and the wavelength. In order to sustain the interaction between these strong wakefields and the accel- erating

Geddes, Cameron Guy Robinson

36

High power density fuel cell comprising an array of microchannels  

DOE Patents [OSTI]

A phosphoric acid fuel cell according to one embodiment includes an array of microchannels defined by a porous electrolyte support structure extending between bottom and upper support layers, the microchannels including fuel and oxidant microchannels; fuel electrodes formed along some of the microchannels; and air electrodes formed along other of the microchannels. A method of making a phosphoric acid fuel cell according to one embodiment includes etching an array of microchannels in a substrate, thereby forming walls between the microchannels; processing the walls to make the walls porous, thereby forming a porous electrolyte support structure; forming anode electrodes along some of the walls; forming cathode electrodes along other of the walls; and filling the porous electrolyte support structure with a phosphoric acid electrolyte. Additional embodiments are also disclosed.

Sopchak, David A; Morse, Jeffrey D; Upadhye, Ravindra S; Kotovsky, Jack; Graff, Robert T

2014-05-06T23:59:59.000Z

37

Imprinted large-scale high density polymer nanopillars for organic solar cells  

E-Print Network [OSTI]

Imprinted large-scale high density polymer nanopillars for organic solar cells Mukti Aryal used to make bulk heterojunction solar cells by depositing PCBM on top of the pillars. Imprinting provides a way to precisely control the interdigitized heterojunction morphology, leading to improved solar

Gao, Jinming

38

Method of Fabrication of High Power Density Solid Oxide Fuel Cells  

DOE Patents [OSTI]

A method for producing ultra-high power density solid oxide fuel cells (SOFCs). The method involves the formation of a multilayer structure cells wherein a buffer layer of doped-ceria is deposited intermediate a zirconia electrolyte and a cobalt iron based electrode using a colloidal spray deposition (CSD) technique. For example, a cobalt iron based cathode composed of (La,Sr)(Co,Fe)O(LSCF) may be deposited on a zirconia electrolyte via a buffer layer of doped-ceria deposited by the CSD technique. The thus formed SOFC have a power density of 1400 mW/cm.sup.2 at 600.degree. C. and 900 mW/cm.sup.2 at 700.degree. C. which constitutes a 2-3 times increased in power density over conventionally produced SOFCs.

Pham, Ai Quoc (San Jose, CA); Glass, Robert S. (Livermore, CA)

2008-09-09T23:59:59.000Z

39

A thermally self-sustained micro solid-oxide fuel-cell stack with high power density  

E-Print Network [OSTI]

A thermally self-sustained micro solid-oxide fuel-cell stack with high power density Zongping Shao1 for portable power generation1,2 . Accordingly, polymer-electrolyte direct- methanol fuel cells design challenges and cannot operate with hydrocarbon fuels of higher energy density. Solid-oxide fuel

Haile, Sossina M.

40

Quantification of nanoscale density fluctuations using electron microscopy: Light-localization properties of biological cells  

SciTech Connect (OSTI)

We report a study of the nanoscale mass-density fluctuations of heterogeneous optical dielectric media, including nanomaterials and biological cells, by quantifying their nanoscale light-localization properties. Transmission electron microscope images of the media are used to construct corresponding effective disordered optical lattices. Light-localization properties are studied by the statistical analysis of the inverse participation ratio (IPR) of the localized eigenfunctions of these optical lattices at the nanoscale. We validated IPR analysis using nanomaterials as models of disordered systems fabricated from dielectric nanoparticles. As an example, we then applied such analysis to distinguish between cells with different degrees of aggressive malignancy.

Pradhan, Prabhakar; Damania, Dhwanil; Turzhitsky, Vladimir; Subramanian, Hariharan; Backman, Vadim [Department of Biomedical Engineering, Northwestern University, Evanston, Illinois 60208 (United States); Joshi, Hrushikesh M.; Dravid, Vinayak P. [Department of Material Science and Engineering, Northwestern University, Evanston, Illinois 60208 (United States); Roy, Hemant K. [Department of Internal Medicine, NorthShore University HealthSystem, Evanston, Illinois 60201 (United States); Taflove, Allen [Department of Electrical Engineering and Computer Science, Northwestern University, Evanston, Illinois 60208 (United States)

2010-12-13T23:59:59.000Z

Note: This page contains sample records for the topic "density lithium-sulfur cells" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Optimization of mesoporous carbon structures for lithium-sulfur battery  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - September 2006 The 2002Optics Group (X-ray Science Division) The

42

Lithium/Sulfur Batteries Based on Doped Mesoporous Carbon - Energy  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: VegetationEquipment Surfaces and Interfaces Sample6, 2011LiisaInnovation Portal Solar Photovoltaic

43

Manipulating the Surface Reactions in Lithium Sulfur Batteries Using Hybrid  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: VegetationEquipment Surfaces and InterfacesAdministration -LowellforRatesManhattan ProjectAnode

44

LOW-TEMPERATURE, ANODE-SUPPORTED HIGH POWER DENSITY SOLID OXIDE FUEL CELLS WITH NANOSTRUCTURED ELECTRODES  

SciTech Connect (OSTI)

A simple, approximate analysis of the effect of differing cathode and anode areas on the measurement of cell performance on anode-supported solid oxide fuel cells, wherein the cathode area is smaller than the anode area, is presented. It is shown that the effect of cathode area on cathode polarization, on electrolyte contribution, and on anode resistance, as normalized on the basis of the cathode area, is negligible. There is a small but measurable effect on anode polarization, which results from concentration polarization. Effectively, it is the result of a greater amount of fuel transported to the anode/electrolyte interface in cases wherein the anode area is larger than the cathode area. Experiments were performed on cells made with differing cathode areas and geometries. Cathodic and anodic overpotentials measured using reference electrodes, and the measured ohmic area specific resistances by current interruption, were in good agreement with expectations based on the analysis presented. At 800 C, the maximum power density measured with a cathode area of {approx}1.1 cm{sup 2} was {approx}1.65 W/cm{sup 2} compared to {approx}1.45 W/cm{sup 2} for cathode area of {approx}2 cm{sup 2}, for anode thickness of {approx}1.3 mm, with hydrogen as the fuel and air as the oxidant. At 750 C, the measured maximum power densities were {approx}1.3 W/cm{sup 2} for the cell with cathode area {approx}1.1 cm{sup 2}, and {approx}1.25 W/cm{sup 2} for the cell with cathode area {approx}2 cm{sup 2}.

Anil V. Virkar

2001-06-21T23:59:59.000Z

45

Durability of Low Platinum Fuel Cells Operating at High Power Density  

SciTech Connect (OSTI)

Understanding and improving the durability of cost-competitive fuel cell stacks is imperative to successful deployment of the technology. Stacks will need to operate well beyond today’s state-of-the-art rated power density with very low platinum loading in order to achieve the cost targets set forth by DOE ($15/kW) and ultimately be competitive with incumbent technologies. An accelerated cost-reduction path presented by Nuvera focused on substantially increasing power density to address non-PGM material costs as well as platinum. The study developed a practical understanding of the degradation mechanisms impacting durability of fuel cells with low platinum loading (?0.2mg/cm2) operating at high power density (?1.0W/cm2) and worked out approaches for improving the durability of low-loaded, high-power stack designs. Of specific interest is the impact of combining low platinum loading with high power density operation, as this offers the best chance of achieving long-term cost targets. A design-of-experiments approach was utilized to reveal and quantify the sensitivity of durability-critical material properties to high current density at two levels of platinum loading (the more conventional 0.45 mgPt.cm–1 and the much lower 0.2 mgPt.cm–2) across several cell architectures. We studied the relevance of selected component accelerated stress tests (AST) to fuel cell operation in power producing mode. New stress tests (NST) were designed to investigate the sensitivity to the addition of electrical current on the ASTs, along with combined humidity and load cycles and, eventually, relate to the combined city/highway drive cycle. Changes in the cathode electrochemical surface area (ECSA) and average oxygen partial pressure on the catalyst layer with aging under AST and NST protocols were compared based on the number of completed cycles. Studies showed elevated sensitivity of Pt growth to the potential limits and the initial particle size distribution. The ECSA loss was correlated with the upper potential limit in the cycle tests, although the performance degradation was found to be a strong function of initial Pt loading. A large fraction of the voltage degradation was found due to increased mass transfer overpotentials, especially in the lower Pt loading cells. Increased mass transfer overpotentials were responsible for a large fraction of the voltage degradation at high current densities. Analysis of the impedance and polarization data indicated O2 diffusion in the aged electrode ionomer to be the main source of the increased mass transfer overpotentials. Results from the experimental parametric studies were used to inform and calibrate newly developed durability model, simulating lifetime performance of the fuel cell under variety of load-cycle protocols, electrode loadings and throughout wide range of operating conditions, including elevated-to-3.0A/cm2 current densities. Complete durability model included several sub-models: platinum dissolution-and-growth as well as reaction-diffusion model of cathode electrode, applied sequentially to study the lifetime predictions of ECSA and polarization performance in the ASTs and NSTs. These models establish relations between changes in overpotentials, ECSA and oxygen mass transport in fuel cell cathodes. The model was calibrated using single cells with land-channel and open flowfield architectures. The model was validated against Nuvera Orion® (open flowfield) short stack data in the load cycle durability tests. The reaction-diffusion model was used to correlate the effective mass transfer coefficients for O2 diffusion in cathode ionomer and separately in gas pores with the operating conditions (pressure, temperature, gas velocity in flow field and current density), Pt loading, and ageing related growth in Pt particles and thinning of the electrode. Achievements of both modeling and experimental objectives were demonstrated in a full format, subscale stacks operating in a simulated but fully realistic ambient environment, using system-compatible operating protocols.

Polevaya, Olga [Nuvera Fuel Cells Inc.] [Nuvera Fuel Cells Inc.; Blanchet, Scott [Nuvera Fuel Cells Inc.] [Nuvera Fuel Cells Inc.; Ahluwalia, Rajesh [Argonne National Lab] [Argonne National Lab; Borup, Rod [Los-Alamos National Lab] [Los-Alamos National Lab; Mukundan, Rangachary [Los-Alamos National Lab] [Los-Alamos National Lab

2014-03-19T23:59:59.000Z

46

Composite Cathode for High-Power Density Solid Oxide Fuel Cells  

SciTech Connect (OSTI)

Reduction of solid oxide fuel cell (SOFC) operating temperature will play a key role in reducing the stack cost by allowing the use of low-cost metallic interconnects and new approaches to sealing, while making applications such as transportation more feasible. Reported results for anode-supported SOFCs show that cathode polarization resistance is the primary barrier to achieving high power densities at operating temperatures of 700 C and lower. This project aims to identify and develop composite cathodes that could reduce SOFC operating temperatures below 700 C. This effort focuses on study and use of (La,Sr)(Co,Fe)O{sub 3} (LSCF) based composite cathodes, which have arguably the best potential to substantially improve on the currently-used, (La,Sr)MnO{sub 3}-Yttria-stabilized Zirconia. During this Phase I, it was successfully demonstrated that high performances can be achieved with LSCF/Gadolinium-Doped Ceria composite cathodes on Ni-based anode supported cells operating at 700 C or lower. We studied electrochemical reactions at LSCF/Yttria-stabilized Zirconia (YSZ) interfaces, and observed chemical reactions between LSCF and YSZ. By using ceria electrolytes or YSZ electrolytes with ceria diffusion barrier layers, the chemical reactions between LSCF and electrolytes were prevented under cathode firing conditions necessary for the optimal adhesion of the cathodes. The protection provided by ceria layer is expected to be adequate for stable long-term cathode performances, but more testing is needed to verify this. Using ceria-based barrier layers, high performance Ni-YSZ anode supported cells have been demonstrated with maximum power densities of 0.8W/cm2 at 700 C and 1.6W/cm{sup 2} at 800 C. Ni-SDC anode supported cells with SDC electrolytes yielded >1W/cm{sup 2} at 600 C. We speculate that the power output of Ni-YSZ anode supported cell at 700 C and lower, was limited by the quality of the Ceria and Ceria YSZ interface. Improvements in the low-temperature performances are expected based on further development of barrier layer fabrication processes and optimization of cathode microstructure.

Ilwon Kim; Scott Barnett; Yi Jiang; Manoj Pillai; Nikkia McDonald; Dan Gostovic; Zhongryang Zhan; Jiang Liu

2004-01-31T23:59:59.000Z

47

Spatially resolved determination of the short-circuit current density of silicon solar cells via lock-in thermography  

SciTech Connect (OSTI)

We present a spatially resolved method to determine the short-circuit current density of crystalline silicon solar cells by means of lock-in thermography. The method utilizes the property of crystalline silicon solar cells that the short-circuit current does not differ significantly from the illuminated current under moderate reverse bias. Since lock-in thermography images locally dissipated power density, this information is exploited to extract values of spatially resolved current density under short-circuit conditions. In order to obtain an accurate result, one or two illuminated lock-in thermography images and one dark lock-in thermography image need to be recorded. The method can be simplified in a way that only one image is required to generate a meaningful short-circuit current density map. The proposed method is theoretically motivated, and experimentally validated for monochromatic illumination in comparison to the reference method of light-beam induced current.

Fertig, Fabian, E-mail: fabian.fertig@ise.fraunhofer.de; Greulich, Johannes; Rein, Stefan [Fraunhofer Institute for Solar Energy Systems ISE, Heidenhofstr. 2, D-79110 Freiburg (Germany)

2014-05-19T23:59:59.000Z

48

LOW-TEMPERATURE, ANODE-SUPPORTED HIGH POWER DENSITY SOLID OXIDE FUEL CELLS WITH NANOSTRUCTURED ELECTRODES  

SciTech Connect (OSTI)

Anode-supported cells comprising Ni + yttria-stabilized zirconia (YSZ) anode, thin ({approx}10 {micro}m) YSZ electrolyte, and composite cathodes containing a mixture of La{sub 0.8}Sr{sub 0.2}MnO{sub (3-{delta})} (LSM) and La{sub 0.9}Sr{sub 0.1}Ga{sub 0.8}Mg{sub 0.2}O{sub (3-{lambda})} (LSGM) were fabricated. The relative proportions of LSGM and LSM were varied between 30 wt.% LSGM + 70 wt.% LSM and 70 wt.% LSGM + 30 wt.% LSM, while the firing temperature was varied between 1000 and 1200 C. The cathode interlayer composition had a profound effect on cathode performance at 800 C with overpotentials ranging between 60 and 425 mV at 1.0 A/cm{sup 2} and exhibiting a minimum for 50 wt.% LSGM + 50 wt.% LSM. The cathodic overpotential decreased with increasing firing temperature of the composite interlayer in the range 1000 {le} T {le} 1150 C, and then increased dramatically for the interlayer fired at 1200 C. The cell with the optimized cathode interlayer of 50 wt.% LSM + 50 wt.% LSGM fired at 1150 C exhibited an area specific cell resistance of 0.18 {Omega}cm{sup 2} and a maximum power density of 1.4 W/cm{sup 2} at 800 C. Chemical analysis revealed that LSGM reacts with YSZ above 1000 C to form the pyrochlore phase, La{sub 2}Zr{sub 2}O{sub 7}. The formation of the pyrochlore phase at the interface between the LSGM/LSM composite cathode and the YSZ electrolyte limits the firing time and temperature of the cathode interlayer.

Anil V. Virkar

2002-03-26T23:59:59.000Z

49

Coumarin Dyes for Dye-Sensitized Solar Cells - A Long-Range-Corrected Density Functional Study  

E-Print Network [OSTI]

The excited-state properties in a series of coumarin solar cell dyes are investigated with a long-range-corrected (LC) functional which asymptotically incorporates Hartree-Fock exchange. Using time-dependent density functional theory (TDDFT), we calculate excitation energies, oscillator strengths, and excited-state dipole moments in each of the dyes as a function of the range-separation paramenter, mu. To investigate the acceptable range of mu and assess the quality of the LC-TDDFT formalism, an extensive comparison is made between LC-BLYP excitation energies and approximate coupled cluster singles and doubles (CC2) calculations. When using a properly-optimized value of mu, we find that the LC technique provides a consistent picture of charge-transfer excitations as a function of molecular size. In contrast, we find that the widely-used B3LYP hybrid functional severely overestimates excited-state dipole moments and underestimates vertical excitations energies, especially for larger dye molecules. The results ...

Wong, Bryan M; 10.1063/1.3025924

2010-01-01T23:59:59.000Z

50

PORTSMOUTH ON-SITE DISPOSAL CELL HIGH DENSITY POLYETHYLENE GEOMEMBRANE LONGEVITY  

SciTech Connect (OSTI)

It is anticipated that high density polyethylene (HDPE) geomembranes will be utilized within the liner and closure cap of the proposed On-Site Disposal Cell (OSDC) at the Portsmouth Gaseous Diffusion Plant. The likely longevity (i.e. service life) of HDPE geomembranes in OSDC service is evaluated within the following sections of this report: (1) Section 2.0 provides an overview of HDPE geomembranes, (2) Section 3.0 outlines potential HDPE geomembranes degradation mechanisms, (3) Section 4.0 evaluates the applicability of HDPE geomembrane degradation mechanisms to the Portsmouth OSDC, (4) Section 5.0 provides a discussion of the current state of knowledge relative to the longevity (service life) of HDPE geomembranes, including the relation of this knowledge to the Portsmouth OSDC, and (5) Section 6.0 provides summary and conclusions relative to the anticipated service life of HDPE geomembranes in OSDC service. Based upon this evaluation it is anticipated that the service life of HDPE geomembranes in OSDC service would be significantly greater than the 200 year service life assumed for the OSDC closure cap and liner HDPE geomembranes. That is, a 200 year OSDC HDPE geomembrane service life is considered a conservative assumption.

Phifer, M.

2012-01-31T23:59:59.000Z

51

Variation of carrier concentration and interface trap density in 8MeV electron irradiated c-Si solar cells  

SciTech Connect (OSTI)

The capacitance and conductance measurements were carried out for c-Si solar cells, irradiated with 8 MeV electrons with doses ranging from 5kGy – 100kGy in order to investigate the anomalous degradation of the cells in the radiation harsh environments. Capacitance – Voltage measurements indicate that there is a slight reduction in the carrier concentration upon electron irradiation due to the creation of radiation induced defects. The conductance measurement results reveal that the interface state densities and the trap time constant increases with electron dose due to displacement damages in c-Si solar cells.

Bhat, Sathyanarayana, E-mail: asharao76@gmail.com; Rao, Asha, E-mail: asharao76@gmail.com [Department of Physics, Mangalore Institute of Technology and Engineering, Moodabidri, Mangalore-574225 (India); Krishnan, Sheeja [Department of Physics, Sri Devi Institute of Technology, Kenjar, Mangalore-574142 (India); Sanjeev, Ganesh [Microtron Centre, Department of Physics, Mangalore University, Mangalagangothri-574199 (India); Suresh, E. P. [Solar Panel Division, ISRO Satellite Centre, Bangalore-560017 (India)

2014-04-24T23:59:59.000Z

52

Development of Large Format Lithium Ion Cells with Higher Energy Density  

Broader source: Energy.gov [DOE]

2013 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting

53

Lateral Current Density Variation in PEM Fuel Cells with Interdigitated Flow Fields.  

E-Print Network [OSTI]

??Proton exchange membrane (PEM) fuel cell is regarded as one of the most promising power systems for the future vehicles. When supplied with air and… (more)

Luo, Song

2014-01-01T23:59:59.000Z

54

Optimization of efficiency and energy density of passive micro fuel cells and galvanic hydrogen generators  

E-Print Network [OSTI]

A PEM micro fuel cell system is described which is based on self-breathing PEM micro fuel cells in the power range between 1 mW and 1W. Hydrogen is supplied with on-demand hydrogen production with help of a galvanic cell, that produces hydrogen when Zn reacts with water. The system can be used as a battery replacement for low power applications and has the potential to improve the run time of autonomous systems. The efficiency has been investigated as function of fuel cell construction and tested for several load profiles.

Hahn, Robert; Krumbholz, Steffen; Reichl, Herbert

2008-01-01T23:59:59.000Z

55

Forming high efficiency silicon solar cells using density-graded anti-reflection surfaces  

DOE Patents [OSTI]

A method (50) is provided for processing a graded-density AR silicon surface (14) to provide effective surface passivation. The method (50) includes positioning a substrate or wafer (12) with a silicon surface (14) in a reaction or processing chamber (42). The silicon surface (14) has been processed (52) to be an AR surface with a density gradient or region of black silicon. The method (50) continues with heating (54) the chamber (42) to a high temperature for both doping and surface passivation. The method (50) includes forming (58), with a dopant-containing precursor in contact with the silicon surface (14) of the substrate (12), an emitter junction (16) proximate to the silicon surface (14) by doping the substrate (12). The method (50) further includes, while the chamber is maintained at the high or raised temperature, forming (62) a passivation layer (19) on the graded-density silicon anti-reflection surface (14).

Yuan, Hao-Chih; Branz, Howard M.; Page, Matthew R.

2014-09-09T23:59:59.000Z

56

PdnCO (n ) 1,2): Accurate Ab Initio Bond Energies, Geometries, and Dipole Moments and the Applicability of Density Functional Theory for Fuel Cell Modeling  

E-Print Network [OSTI]

and the Applicability of Density Functional Theory for Fuel Cell Modeling Nathan E. Schultz, Benjamin F. Gherman Form: August 18, 2006 Electrode poisoning by CO is a major concern in fuel cells. As interest. Introduction Several of the most successful fuel cell applications use a Pt anode as a catalyst

Gherman, Benjamin F.

57

Solution Ionic Strength Engineering As a Generic Strategy to Coat Graphene Oxide (GO) on Various Functional Particles and Its  

E-Print Network [OSTI]

, such as lithium-ion battery electrode materials,2-4 corrosion inhib- itor,5,6 photocatalysts,7 solar cells,8 Functional Particles and Its Application in High-Performance Lithium-Sulfur (Li-S) Batteries Jiepeng Rong as an example for lithium-sulfur (Li-S) battery application with superior performance. Particles of different

Zhou, Chongwu

58

The joint statistics of mildly non-linear cosmological densities and slopes in count-in-cells  

E-Print Network [OSTI]

In the context of count-in-cells statistics, the joint probability distribution of the density in two concentric spherical shells is predicted from first first principle for sigmas of the order of one. The agreement with simulation is found to be excellent. This statistics allows us to deduce the conditional one dimensional probability distribution function of the slope within under dense (resp. overdense) regions, or of the density for positive or negative slopes. The former conditional distribution is likely to be more robust in constraining the cosmological parameters as the underlying dynamics is less evolved in such regions. A fiducial dark energy experiment is implemented on such counts derived from Lambda-CDM simulations.

Bernardeau, Francis; Pichon, Christophe

2015-01-01T23:59:59.000Z

59

Enhancement of short-circuit current density in polymer bulk heterojunction solar cells comprising plasmonic silver nanowires  

SciTech Connect (OSTI)

We demonstrate that the influence of plasmonic effects based on silver nanowires (Ag NWs) on the characteristics of polymer solar cells (PSCs). The solution-processed Ag NWs are situated at the interface of anode buffer layer and active layer, which could enhance the performance especially the photocurrent of PSCs by scattering, localized surface plasmon resonance, and surface plasmon polaritons. Plasmonic effects are confirmed by the enhancement of extinction spectra, external quantum efficiency, and steady state photoluminescence. Consequently, the short-circuit current density (J{sub sc}) and power conversion efficiency enhance about 24% and 18%, respectively, under AM1.5 illumination when Ag NWs plasmonic nanostructure incorporated into PSCs.

Yang, Yuzhao; Lin, Xiaofeng; Ou, Jiemei; Chen, Xudong, E-mail: cescxd@mail.sysu.edu.cn, E-mail: stszx@mail.sysu.edu.cn, E-mail: chenyj69@mail.sysu.edu.cn [Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education of China, Sun Yat-sen University, Guangzhou 510275 (China); Qing, Jian; Zhong, Zhenfeng; Zhou, Xiang, E-mail: cescxd@mail.sysu.edu.cn, E-mail: stszx@mail.sysu.edu.cn, E-mail: chenyj69@mail.sysu.edu.cn; Chen, Yujie, E-mail: cescxd@mail.sysu.edu.cn, E-mail: stszx@mail.sysu.edu.cn, E-mail: chenyj69@mail.sysu.edu.cn [State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Hu, Chenglong [Key Laboratory of Optoelectronic Chemical Materials and Devices of Ministry of Education, Jianghan University, Wuhan 430056 (China)

2014-03-24T23:59:59.000Z

60

Vehicle Technologies Office Merit Review 2014: High Energy Density Li-ion Cells for EV’s Based on Novel, High Voltage Cathode Material Systems  

Broader source: Energy.gov [DOE]

Presentation given by Farasis Energy, Inc. at 2014 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about high energy density Li...

Note: This page contains sample records for the topic "density lithium-sulfur cells" from the National Library of EnergyBeta (NLEBeta).
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61

Charge density dependent nongeminate recombination in organic bulk heterojunction solar cells  

E-Print Network [OSTI]

Apparent recombination orders exceeding the value of two expected for bimolecular recombination have been reported for organic solar cells in various publications. Two prominent explanations are bimolecular losses with a carrier concentration dependent prefactor due to a trapping limited mobility, and protection of trapped charge carriers from recombination by a donor--acceptor phase separation until reemission from these deep states. In order to clarify which mechanism is dominant we performed temperature and illumination dependent charge extraction measurements under open circuit as well as short circuit conditions at poly(3-hexylthiophene-2,5-diyl):[6,6]-phenyl-C$_{61}$butyric acid methyl ester (P3HT:PC$_{61}$BM) and PTB7:PC$_{71}$BM (Poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl

D. Rauh; C. Deibel; V. Dyakonov

2012-03-27T23:59:59.000Z

62

Identification of Catalysts and Materials for a High-Energy Density Biochemical Fuel Cell: Cooperative Research and Development Final Report, CRADA Number CRD-09-345  

SciTech Connect (OSTI)

The proposed research attempted to identify novel biochemical catalysts, catalyst support materials, high-efficiency electron transfer agents between catalyst active sites and electrodes, and solid-phase electrolytes in order to maximize the current density of biochemical fuel cells that utilize various alcohols as substrates.

Ghirardi, M.; Svedruzic, D.

2013-07-01T23:59:59.000Z

63

CX-003069: Categorical Exclusion Determination  

Broader source: Energy.gov [DOE]

Scion Power - Development of High Energy Lithium Sulfur Cells for Electric VehiclesCX(s) Applied: B3.6Date: 06/02/2010Location(s): WashingtonOffice(s): Advanced Research Projects Agency - Energy

64

Molecular Structures of Polymer/Sulfur Composites for Lithium-Sulfur Batteries with Long Cycle Life  

SciTech Connect (OSTI)

Vulcanizedpolyaniline/sulfur (SPANI/S) nanostructures were investigated for Li-S battery applications, but the detailed molecular structures of such composites have not been fully illustrated. In this paper, we synthesize SPANI/S composites with different S content in a nanorod configuration. FTIR, Raman, XPS, XRD, SEM and elemental analysis methods are used to characterize the molecular structure of the materials. We provide clear evidence that a portion of S was grafted on PANI during heating and connected the PANI chains with disulfide bonds to form a crosslinked network and the rest of S was encapsulated within it.. Polysulfides and elementary sulfur nanoparticles are physically trapped inside the polymer network and are not chemically bound to the polymer. The performance of the composites is further improved by reducing the particle size. Even after 500 cycles a capacity retention rate of 68.8% is observed in the SPANI/S composite with 55% S content.

Xiao, Lifen; Cao, Yuliang; Xiao, Jie; Schwenzer, Birgit; Engelhard, Mark H.; Saraf, Laxmikant V.; Nie, Zimin; Exarhos, Gregory J.; Liu, Jun

2013-04-26T23:59:59.000Z

65

Sulfur@Carbon Cathodes for Lithium Sulfur Batteries > Research Highlights >  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation Desert Southwest RegionatSearchScheduled System Burst Buffer Archive HomeStump|CenterResearch

66

Molecular Structures of Polymer/Sulfur Composites for Lithium-Sulfur  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: VegetationEquipment SurfacesResource ProgramModification and ApplicationMolecular Structure

67

Carbon/Sulfur Nanocomposites and Additives for High-Energy Lithium Sulfur  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-Up fromDepartmentTie Ltd:June 20154:04-21-2014 (866) 448 -Illinois Basin |Batteries |

68

Carbon/Sulfur Nanocomposites and Additives for High-Energy Lithium Sulfur  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-Up fromDepartmentTie Ltd:June 20154:04-21-2014 (866) 448 -Illinois Basin |Batteries

69

Vehicle Technologies Office Merit Review 2014: Development of Large Format Lithium Ion Cells with Higher Energy Density  

Broader source: Energy.gov [DOE]

Presentation given by XALT Energy LLC at 2014 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about development of large format...

70

Gas-to-liquids synthetic fuels for use in fuel cells : reformability, energy density, and infrastructure compatibility.  

SciTech Connect (OSTI)

The fuel cell has many potential applications, from power sources for electric hybrid vehicles to small power plants for commercial buildings. The choice of fuel will be critical to the pace of its commercialization. This paper reviews the various liquid fuels being considered as an alternative to direct hydrogen gas for the fuel cell application, presents calculations of the hydrogen and carbon dioxide yields from autothermal reforming of candidate liquid fuels, and reports the product gas composition measured from the autothermal reforming of a synthetic fuel in a micro-reactor. The hydrogen yield for a synthetic paraffin fuel produced by a cobalt-based Fischer-Tropsch process was found to be similar to that of retail gasoline. The advantages of the synthetic fuel are that it contains no contaminants that would poison the fuel cell catalyst, is relatively benign to the environment, and could be transported in the existing fuel distribution system.

Ahmed, S.; Kopasz, J. P.; Russell, B. J.; Tomlinson, H. L.

1999-09-08T23:59:59.000Z

71

Novel and Optimized Materials Phases for High Energy Density...  

Broader source: Energy.gov (indexed) [DOE]

Novel and Optimized Materials Phases for High Energy Density Batteries Novel and Optimized Materials Phases for High Energy Density Batteries 2013 DOE Hydrogen and Fuel Cells...

72

Controlled Nucleation and Growth Process of Li2S2/Li2S in Lithium-Sulfur  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed New SubstationCleanCommunity2Workshops01 SF-30

73

Design of Safer High-Energy Density Materials for Lithium-Ion...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

of Safer High-Energy Density Materials for Lithium-Ion Cells Design of Safer High-Energy Density Materials for Lithium-Ion Cells 2012 DOE Hydrogen and Fuel Cells Program and...

74

Development of Large Format Lithium Ion Cells with Higher Energy...  

Broader source: Energy.gov (indexed) [DOE]

Large Format Lithium Ion Cells with Higher Energy Density Development of Large Format Lithium Ion Cells with Higher Energy Density 2013 DOE Hydrogen and Fuel Cells Program and...

75

Low density microcellular foams  

DOE Patents [OSTI]

Disclosed is a process of producing microcellular from which comprises the steps of: (a) selecting a multifunctional epoxy oligomer resin; (b) mixing said epoxy resin with a non-reactive diluent to form a resin-diluent mixture; (c) forming a diluent containing cross-linked epoxy gel from said resin-diluent mixture; (d) replacing said diluent with a solvent therefore; (e) replacing said solvent with liquid carbon dioxide; and (f) vaporizing off said liquid carbon dioxide under supercritical conditions, whereby a foam having a density in the range of 35-150 mg/cc and cell diameters less than about 1 .mu.m is produced. Also disclosed are the foams produced by the process.

LeMay, James D. (Castro Valley, CA)

1992-01-01T23:59:59.000Z

76

Low density microcellular foams  

DOE Patents [OSTI]

Disclosed is a process of producing microcellular foam which comprises the steps of: (a) selecting a multifunctional epoxy oligomer resin; (b) mixing said epoxy resin with a non-reactive diluent to form a resin-diluent mixture; (c) forming a diluent containing cross-linked epoxy gel from said resin-diluent mixture; (d) replacing said diluent with a solvent therefore; (e) replacing said solvent with liquid carbon dioxide; and (f) vaporizing off said liquid carbon dioxide under supercritical conditions, whereby a foam having a density in the range of 35-150 mg/cc and cell diameters less than about 1 [mu]m is produced. Also disclosed are the foams produced by the process. 8 figures.

LeMay, J.D.

1991-11-19T23:59:59.000Z

77

Low density microcellular foams  

DOE Patents [OSTI]

Disclosed is a process of producing microcellular foam which comprises the steps of: (a) selecting a multifunctional epoxy oligomer resin; (b) mixing said epoxy resin with a non-reactive diluent to form a resin-diluent mixture; (c) forming a diluent containing cross-linked epoxy gel from said resin-diluent mixture; (d) replacing said diluent with a solvent therefore; (e) replacing said solvent with liquid carbon dioxide; and (f) vaporizing off said liquid carbon dioxide under supercritical conditions, whereby a foam having a density in the range of 35-150 mg/cc and cell diameters less than about 1 .mu.m is produced. Also disclosed are the foams produced by the process.

LeMay, James D. (Castro Valley, CA)

1991-01-01T23:59:59.000Z

78

Low density, resorcinol-formaldehyde aerogels  

DOE Patents [OSTI]

The polycondensation of resorcinol with formaldehyde under alkaline conditions results in the formation of surface functionalized polymer ''clusters''. The covalent crosslinking of these ''clusters'' produces gels which when processed under supercritical conditions, produce low density, organic aerogels (density less than or equal to100 mg/cc; cell size less than or equal to0.1 microns). The aerogels are transparent,dark red in color and consist of interconnected colloidal-like particles with diameters of about 100 A/degree/. These aerogels may be further carbonized to form low density carbon foams with cell size of about 0.1 micron. 1 fig., 1 tab.

Pekala, R.W.

1988-05-26T23:59:59.000Z

79

Low density, resorcinol-formaldehyde aerogels  

DOE Patents [OSTI]

The polycondensation of resorcinol with formaldehyde under alkaline conditions results in the formation of surface functionalized polymer "Clusters". The covalent crosslinking of these "clusters" produces gels which when processed under supercritical conditions, produce low density, organic aerogels (density.ltoreq.100 mg/cc; cell size .ltoreq.0.1 microns). The aerogels are transparent, dark red in color and consist of interconnected colloidal-like particles with diameters of about 100.circle.. These aerogels may be further carbonized to form low density carbon foams with cell size of about 0.1 micron.

Pekala, Richard W. (Pleasant Hill, CA)

1991-01-01T23:59:59.000Z

80

Low density, resorcinol-formaldehyde aerogels  

SciTech Connect (OSTI)

The polycondensation of resorcinol with formaldehyde under alkaline conditions results in the formation of surface functionalized polymer "clusters". The covalent crosslinking of these "clusters" produces gels which when processed under supercritical conditions, produce low density, organic aerogels (density .ltoreq.100 mg/cc; cell size .ltoreq.0.1 microns). The aerogels are transparent, dark red in color and consist of interconnected colloidal-like particles with diameters of about 100 .ANG.. These aerogels may be further carbonized to form low density carbon foams with cell size of about 0.1 micron.

Pekala, Richard W. (Pleasant Hill, CA)

1989-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "density lithium-sulfur cells" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Low density, resorcinol-formaldehyde aerogels  

DOE Patents [OSTI]

The polycondensation of resorcinol with formaldehyde under alkaline conditions results in the formation of surface functionalized polymer clusters. The covalent crosslinking of these clusters produces gels which when processed under supercritical conditions, produce low density, organic aerogels (density [<=]100 mg/cc; cell size [<=]0.1 microns). The aerogels are transparent, dark red in color and consist of interconnected colloidal-like particles with diameters of about 100 [angstrom]. These aerogels may be further carbonized to form low density carbon foams with cell size of about 0.1 micron.

Pekala, R.W.

1989-10-10T23:59:59.000Z

82

Mapping the energy and diffusion landscapes of membrane proteins at the cell surface using high-density single-molecule imaging and Bayesian inference: application to the multi-scale dynamics of glycine receptors in the neuronal membrane  

E-Print Network [OSTI]

Protein mobility is conventionally analyzed in terms of an effective diffusion. Yet, this description often fails to properly distinguish and evaluate the physical parameters (such as the membrane friction) and the biochemical interactions governing the motion. Here, we present a method combining high-density single-molecule imaging and statistical inference to separately map the diffusion and energy landscapes of membrane proteins across the cell surface at ~100 nm resolution (with acquisition of a few minutes). When applying these analytical tools to glycine neurotransmitter receptors (GlyRs) at inhibitory synapses, we find that gephyrin scaffolds act as shallow energy traps (~3 kBT) for GlyRs, with a depth modulated by the biochemical properties of the receptor-gephyrin interaction loop. In turn, the inferred maps can be used to simulate the dynamics of proteins in the membrane, from the level of individual receptors to that of the population, and thereby, to model the stochastic fluctuations of physiologi...

Masson, Jean-Baptiste; Salvatico, Charlotte; Renner, Marianne; Specht, Christian G; Triller, Antoine; Dahan, Maxime

2015-01-01T23:59:59.000Z

83

Pair densities in density functional theory  

E-Print Network [OSTI]

The exact interaction energy of a many-electron system is determined by the electron pair density, which is not well-approximated in standard Kohn-Sham density functional models. Here we study the (complicated but well-defined) exact universal map from density to pair density. We show that many common functionals, including the most basic version of the LDA (Dirac exchange with no correlation contribution), arise from particular approximations of this map. We develop an algorithm to compute the map numerically, and apply it to one-parameter families {a*rho(a*x)} of one-dimensional homogeneous and inhomogeneous single-particle densities. We observe that the pair density develops remarkable multiscale patterns which strongly depend on both the particle number and the "width" 1/a of the single-particle density. The simulation results are confirmed by rigorous asymptotic results in the limiting regimes a>>1 and a<<1. For one-dimensional homogeneous systems, we show that the whole spectrum of patterns is rep...

Chen, Huajie

2015-01-01T23:59:59.000Z

84

Vehicle Technologies Office Merit Review 2014: High Energy Density...  

Broader source: Energy.gov (indexed) [DOE]

Vehicle Technologies Office Merit Review 2014: High Energy Density Li-ion Cells for EV's Based on Novel, High Voltage Cathode Material Systems Vehicle Technologies Office Merit...

85

Equation for liquid density  

SciTech Connect (OSTI)

Saturated liquid densities for organic chemicals are given as functions of temperature using a modified Rackett equation.

Yaws, C.L.; Yang, H.C.; Hopper, J.R.; Cawley, W.A. (Lamar Univ., Beaumont, TX (US))

1991-01-01T23:59:59.000Z

86

Carbon/Sulfur Nanocomposites and Additives for High-Energy Lithium...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Documents & Publications CarbonSulfur Nanocomposites and Additives for High-Energy Lithium Sulfur Batteries Additives and Cathode Materials for High-Energy Lithium Sulfur...

87

Ionic Liquid-Enhanced Solid State Electrolyte Interface (SEI...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Liquid-Enhanced Solid State Electrolyte Interface (SEI) for Lithium Sulfur Batteries. Ionic Liquid-Enhanced Solid State Electrolyte Interface (SEI) for Lithium Sulfur Batteries....

88

Optimization of mesoporous carbon structures for lithium&ndash...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

mesoporous carbon structures for lithium–sulfur battery applications. Optimization of mesoporous carbon structures for lithium–sulfur battery applications. Abstract:...

89

The reversal of the laser-beam-induced-current contrast with varying illumination density in a Cu{sub 2}ZnSnSe{sub 4} thin-film solar cell  

SciTech Connect (OSTI)

We apply an array of correlated spatially-resolved techniques, including ?-Raman/photoluminescence/reflectance/laser-beam-induced-current in conjunction with scanning electron microscopy and atomic force microscopy, to study the impact of the microscopic-scale thickness inhomogeneity of CdS layer in a Cu{sub 2}ZnSnSe{sub 4} thin-film solar cell. Thicker CdS regions are found to cause more light reflecting loss thus yield lower external quantum efficiencies and energy conversion efficiencies than the general area. However, these regions show much less efficiency degradation at high illumination intensity, leading to an inversion of laser-beam-induced-current contrast in the area mapping. While improving the CdS layer uniformity can boost the device performance, the finding further points out the possibility of operating thin-film photovoltaic devices based on the similar materials (such as CuInGaSe{sub 2}, CdTe, Cu{sub 2}ZnSn(S,Se){sub 4}) under a substantially higher illumination density for concentrated photovoltaic and photo-detection.

Chen, Qiong; Zhang, Yong, E-mail: yong.zhang@uncc.edu [Department of Electrical and Computer Engineering, and Energy Production and Infrastructure Center (EPIC), The University of North Carolina at Charlotte, Charlotte, North Carolina 28223 (United States)] [Department of Electrical and Computer Engineering, and Energy Production and Infrastructure Center (EPIC), The University of North Carolina at Charlotte, Charlotte, North Carolina 28223 (United States)

2013-12-09T23:59:59.000Z

90

Density-dependent covariant energy density functionals  

SciTech Connect (OSTI)

Relativistic nuclear energy density functionals are applied to the description of a variety of nuclear structure phenomena at and away fromstability line. Isoscalar monopole, isovector dipole and isoscalar quadrupole giant resonances are calculated using fully self-consistent relativistic quasiparticle randomphase approximation, based on the relativistic Hartree-Bogoliubovmodel. The impact of pairing correlations on the fission barriers in heavy and superheavy nuclei is examined. The role of pion in constructing desnity functionals is also investigated.

Lalazissis, G. A. [Physics Department, Aristotle University of Thessaloniki, GR-54124 (Greece)

2012-10-20T23:59:59.000Z

91

Density Matrix Topological Insulators  

E-Print Network [OSTI]

Thermal noise can destroy topological insulators (TI). However we demonstrate how TIs can be made stable in dissipative systems. To that aim, we introduce the notion of band Liouvillian as the dissipative counterpart of band Hamiltonian, and show a method to evaluate the topological order of its steady state. This is based on a generalization of the Chern number valid for general mixed states (referred to as density matrix Chern value), which witnesses topological order in a system coupled to external noise. Additionally, we study its relation with the electrical conductivity at finite temperature, which is not a topological property. Nonetheless, the density matrix Chern value represents the part of the conductivity which is topological due to the presence of quantum mixed edge states at finite temperature. To make our formalism concrete, we apply these concepts to the two-dimensional Haldane model in the presence of thermal dissipation, but our results hold for arbitrary dimensions and density matrices.

A. Rivas; O. Viyuela; M. A. Martin-Delgado

2013-10-31T23:59:59.000Z

92

Density Functional Theory for Superconductors  

E-Print Network [OSTI]

Density Functional Theory for Superconductors LATHIOTAKIS, A. MARQUES, 1,2,3 LU DERS, L. FAST, 2004 words: theory superconductors; density functional theory; critical temperature; exchange matter physics theoretical chemistry is density functional theory (DFT). foundations were established mid

Gross, E.K.U.

93

Micro Fuel Cells Direct Methanol Fuel Cells  

E-Print Network [OSTI]

energy density of 1.5 Wh/cc; 1.5Wh/g = X5; x10 energy density of Li ion battery * Direct & complete Content (Wh) Volume(cm^3) Li-Ion Battery DMFC #12;Micro Fuel Cells TM State of MTI Micro Fuel Cells Energy Content (Wh) Volume(cm^3) Li-Ion Battery DMFC #12;Direct Methanol Fuel Cell Technology

94

Multiple density layered insulator  

DOE Patents [OSTI]

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.

Alger, T.W.

1994-09-06T23:59:59.000Z

95

Multiple density layered insulator  

DOE Patents [OSTI]

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.

Alger, Terry W. (Tracy, CA)

1994-01-01T23:59:59.000Z

96

Energy in density gradient  

E-Print Network [OSTI]

Inhomogeneous plasmas and fluids contain energy stored in inhomogeneity and they naturally tend to relax into lower energy states by developing instabilities or by diffusion. But the actual amount of energy in such inhomogeneities has remained unknown. In the present work the amount of energy stored in a density gradient is calculated for several specific density profiles in a cylindric configuration. This is of practical importance for drift wave instability in various plasmas, and in particular in its application in models dealing with the heating of solar corona because the instability is accompanied with stochastic heating, so the energy contained in inhomogeneity is effectively transformed into heat. It is shown that even for a rather moderate increase of the density at the axis in magnetic structures in the corona by a factor 1.5 or 3, the amount of excess energy per unit volume stored in such a density gradient becomes several orders of magnitude greater than the amount of total energy losses per unit ...

Vranjes, J

2015-01-01T23:59:59.000Z

97

Low density, microcellular foams, preparation, and articles  

DOE Patents [OSTI]

A microcellular low-density foam of poly(4-methyl-1-pentene) particularly useful for forming targets for inertial confinement fusion has been developed. Articles made from the foam have been machined to tolerances of 0.0001 inch, although the densities of the fragile foam are low (about 10 to about 100 mg/cc) and the cell sizes are small (about 10 to about 30 ..mu..m). Methods for forming the foam and articles are given. The yield strength of the foam of the invention is higher than was obtained in other structures of this same material.

Young, A.T.

1982-03-03T23:59:59.000Z

98

Gedanken densities and exact constraints in density functional theory  

SciTech Connect (OSTI)

Approximations to the exact density functional for the exchange-correlation energy of a many-electron ground state can be constructed by satisfying constraints that are universal, i.e., valid for all electron densities. Gedanken densities are designed for the purpose of this construction, but need not be realistic. The uniform electron gas is an old gedanken density. Here, we propose a spherical two-electron gedanken density in which the dimensionless density gradient can be an arbitrary positive constant wherever the density is non-zero. The Lieb-Oxford lower bound on the exchange energy can be satisfied within a generalized gradient approximation (GGA) by bounding its enhancement factor or simplest GGA exchange-energy density. This enhancement-factor bound is well known to be sufficient, but our gedanken density shows that it is also necessary. The conventional exact exchange-energy density satisfies no such local bound, but energy densities are not unique, and the simplest GGA exchange-energy density is not an approximation to it. We further derive a strongly and optimally tightened bound on the exchange enhancement factor of a two-electron density, which is satisfied by the local density approximation but is violated by all published GGA's or meta-GGA’s. Finally, some consequences of the non-uniform density-scaling behavior for the asymptotics of the exchange enhancement factor of a GGA or meta-GGA are given.

Perdew, John P. [Department of Physics, Temple University, Philadelphia, Pennsylvania 19122 (United States) [Department of Physics, Temple University, Philadelphia, Pennsylvania 19122 (United States); Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122 (United States); Ruzsinszky, Adrienn; Sun, Jianwei [Department of Physics, Temple University, Philadelphia, Pennsylvania 19122 (United States)] [Department of Physics, Temple University, Philadelphia, Pennsylvania 19122 (United States); Burke, Kieron [Department of Chemistry and Department of Physics, University of California, Irvine, California 92697 (United States)] [Department of Chemistry and Department of Physics, University of California, Irvine, California 92697 (United States)

2014-05-14T23:59:59.000Z

99

High Energy Density Capacitors  

SciTech Connect (OSTI)

BEEST Project: Recapping is developing a capacitor that could rival the energy storage potential and price of today’s best EV batteries. When power is needed, the capacitor rapidly releases its stored energy, similar to lightning being discharged from a cloud. Capacitors are an ideal substitute for batteries if their energy storage capacity can be improved. Recapping is addressing storage capacity by experimenting with the material that separates the positive and negative electrodes of its capacitors. These separators could significantly improve the energy density of electrochemical devices.

None

2010-07-01T23:59:59.000Z

100

Gluon density in nuclei  

SciTech Connect (OSTI)

In this talk we present our detailed study (theory and numbers) on the shadowing corrections to the gluon structure functions for nuclei. Starting from rather controversial information on the nucleon structure function which is originated by the recent HERA data, we develop the Glauber approach for the gluon density in a nucleus based on Mueller formula and estimate the value of the shadowing corrections in this case. Then we calculate the first corrections to the Glauber approach and show that these corrections are big. Based on this practical observation we suggest the new evolution equation which takes into account the shadowing corrections and solve it. We hope to convince you that the new evolution equation gives a good theoretical tool to treat the shadowing corrections for the gluons density in a nucleus and, therefore, it is able to provide the theoretically reliable initial conditions for the time evolution of the nucleus-nucleus cascade. The initial conditions should be fixed both theoretically and phenomenologically before to attack such complicated problems as the mixture of hard and soft processes in nucleus-nucleus interactions at high energy or the theoretically reliable approach to hadron or/and parton cascades for high energy nucleus-nucleus interaction. 35 refs., 24 figs., 1 tab.

Ayala, A.L. [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Inst. de Fisica][Pelotas Univ., RS (Brazil). Inst. de Fisica e Matematica; Ducati, M.B.G. [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Inst. de Fisica; Levin, E.M. [Fermi National Accelerator Lab., Batavia, IL (United States)][Nuclear Physics Inst., St. Petersburg (Russian Federation)

1996-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "density lithium-sulfur cells" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Density constrained TDHF  

E-Print Network [OSTI]

In this manuscript we provide an outline of the numerical methods used in implementing the density constrained time-dependent Hartree-Fock (DC-TDHF) method and provide a few examples of its application to nuclear fusion. In this approach, dynamic microscopic calculations are carried out on a three-dimensional lattice and there are no adjustable parameters, the only input is the Skyrme effective NN interaction. After a review of the DC-TDHF theory and the numerical methods, we present results for heavy-ion potentials $V(R)$, coordinate-dependent mass parameters $M(R)$, and precompound excitation energies $E^{*}(R)$ for a variety of heavy-ion reactions. Using fusion barrier penetrabilities, we calculate total fusion cross sections $\\sigma(E_\\mathrm{c.m.})$ for reactions between both stable and neutron-rich nuclei. We also determine capture cross sections for hot fusion reactions leading to the formation of superheavy elements.

Oberacker, V E

2015-01-01T23:59:59.000Z

102

Nuclear Energy Density Optimization  

E-Print Network [OSTI]

We carry out state-of-the-art optimization of a nuclear energy density of Skyrme type in the framework of the Hartree-Fock-Bogoliubov (HFB) theory. The particle-hole and particle-particle channels are optimized simultaneously, and the experimental data set includes both spherical and deformed nuclei. The new model-based, derivative-free optimization algorithm used in this work has been found to be significantly better than standard optimization methods in terms of reliability, speed, accuracy, and precision. The resulting parameter set UNEDFpre results in good agreement with experimental masses, radii, and deformations and seems to be free of finite-size instabilities. An estimate of the reliability of the obtained parameterization is given, based on standard statistical methods. We discuss new physics insights offered by the advanced covariance analysis.

M. Kortelainen; T. Lesinski; J. Moré; W. Nazarewicz; J. Sarich; N. Schunck; M. V. Stoitsov; S. Wild

2010-05-27T23:59:59.000Z

103

Density Functional Theory for Superconductors  

E-Print Network [OSTI]

Density Functional Theory for Superconductors N. N. LATHIOTAKIS,1,2 M. A. L. MARQUES,1,2,3 M. LU; density functional theory; critical temperature; exchange and correlation; phonon and theoretical chemistry is density functional theory (DFT). Its foundations were established in the mid-1960s

Gross, E.K.U.

104

Development of Large Format Lithium Ion Cells with Higher Energy...  

Broader source: Energy.gov (indexed) [DOE]

Overall Project Goal: To research, develop and demonstrate large format lithium ion cells with energy density > 500 WhL Barriers addressed: - Low energy density - Cost -...

105

Genetic variation of packing density within a selected population of Loblolly Pine (Pinus taeda L.  

E-Print Network [OSTI]

. Specific gravity of cell wall material Factors affecting the specific gravity of cell wall material Importance of the specific gravity of cell wall material Recent investigations concerning packing density 12 Chapter IV. Experimental des ign 13... Discussion of materials 13 Sample size 14 Chapter V. Method used for determining packing density in small wood samples 15 Definition and calculation 15 Measurement of specific gravity Measurement of cell wall material 15 17 Summary of overall...

Boyd, Lamar

1967-01-01T23:59:59.000Z

106

Canonical density matrix perturbation theory  

E-Print Network [OSTI]

Density matrix perturbation theory [Niklasson and Challacombe, Phys. Rev. Lett. 92, 193001 (2004)] is generalized to canonical (NVT) free energy ensembles in tight-binding, Hartree-Fock or Kohn-Sham density functional theory. The canonical density matrix perturbation theory can be used to calculate temperature dependent response properties from the coupled perturbed self-consistent field equations as in density functional perturbation theory. The method is well suited to take advantage of sparse matrix algebra to achieve linear scaling complexity in the computational cost as a function of system size for sufficiently large non-metallic materials and metals at high temperatures.

Niklasson, Anders M N; Rubensson, Emanuel H; Rudberg, Elias

2015-01-01T23:59:59.000Z

107

Generation of Gaussian Density Fields  

E-Print Network [OSTI]

This document describes analytical and numerical techniques for the generation of Gaussian density fields, which represent cosmological density perturbations. The mathematical techniques involved in the generation of density harmonics in k-space, the filtering of the density fields, and the normalization of the power spectrum to the measured temperature fluctuations of the Cosmic Microwave Background, are presented in details. These techniques are well-known amongst experts, but the current literature lacks a formal description. I hope that this technical report will prove useful to new researchers moving into this field, sparing them the task of reinventing the wheel.

Hugo Martel

2005-07-15T23:59:59.000Z

108

Density Functional Theory (DFT) Simulated Annealing (SA)  

E-Print Network [OSTI]

. . . . . . . . 9 2009 #12;! " # $ % & - " # $ %' ! " # # $ % & # ( # " ) Density Functional Theory) % Lattice-Boltzmann (LBM) #12;! " # $ % & - " # $ %' ! " # # $ % & # ( # " ) Density Functional Theory (DFT;! " # $ % & - " # $ %' ! " # # $ % & # ( # " ) Density Functional Theory (DFT) Simulated Annealing (SA) Monte Carlo &$ ' ' (GCMC

109

Development of Large Format Lithium Ion Cells with Higher Energy...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Large Format Lithium Ion Cells with Higher Energy Density Exceeding 500WhL Development of Large Format Lithium Ion Cells with Higher Energy Density Exceeding 500WhL 2012 DOE...

110

Detecting Density Variations and Nanovoids  

SciTech Connect (OSTI)

A combination of simulated and experimental data has been used to investigate the size range of nanovoids that can be detected in atom probe tomography data. Simulated atom probe tomography data have revealed that nanovoids as small as 1 nm in diameter can be detected in atom probe tomography data with the use of iso-density surfaces. Iso-density surfaces may be used to quantify the size, morphology and number density of nanovoids and other variations in density in atom probe tomography data. Experimental data from an aluminum-yttrium-iron metallic glass ribbon have revealed the effectiveness of this approach. Combining iso-density surfaces with atom maps also permits the segregation of solute to the nanovoids to be investigated. Field ion microscopy and thin section atom maps have also been used to detect pores and larger voids.

Miller, Michael K [ORNL; Longstreth-Spoor, L. [Washington University, St. Louis; Kelton, K. F. [Washington University, St. Louis

2011-01-01T23:59:59.000Z

111

Innovative Cell Materials and Designs for 300 Mile Range EVs  

Broader source: Energy.gov (indexed) [DOE]

Multiple On track Test Cell Multiple On track Delivered year 2013 high energy density cells on 11014 On track Systems Integration Design 93112 On track Test Reports...

112

Innovative Cell Materials and Designs for 300 Mile Range EVs  

Broader source: Energy.gov (indexed) [DOE]

and characterization Multiple On track Test Cell Multiple On track Delivered 18 cells with high energy density on Nov. 30 th , 2012 On track Systems Integration Design 9...

113

Characterization of Neuropeptide Y Expressing Cells in the Mouse Retina  

E-Print Network [OSTI]

present in two layers, the inner nuclear layer (INL) and the ganglion cell layer (GCL). The cells in both layers were densely distributed, with those in the INL having a mean density of 1452 65 cells/mm2 , and those in the GCL having a mean density of 644 41 cells/mm2 . The cells in the INL extended

Nirenberg, Sheila

114

Density and pair-density scaling for deriving the Euler equation in density-functional and pair-density-functional theory  

SciTech Connect (OSTI)

A link between density and pair density functional theories is presented. Density and pair density scaling are used to derive the Euler equation in both theories. Density scaling provides a constructive way of obtaining approximations for the Pauli potential. The Pauli potential (energy) of the density functional theory is expressed as the difference of the scaled and original exchange-correlation potentials (energies).

Nagy, A. [Department of Theoretical Physics, University of Debrecen, H-4010 Debrecen (Hungary)

2011-09-15T23:59:59.000Z

115

Phenomenological Relativistic Energy Density Functionals  

SciTech Connect (OSTI)

The framework of relativistic nuclear energy density functionals is applied to the description of a variety of nuclear structure phenomena, not only in spherical and deformed nuclei along the valley of beta-stability, but also in exotic systems with extreme isospin values and close to the particle drip-lines. Dynamical aspects of exotic nuclear structure is explored using the fully consistent quasiparticle random-phase approximation based on the relativistic Hartree-Bogoliubov model. Recent applications of energy density functionals with explicit density dependence of the meson-nucleon couplings are presented.

Lalazissis, G. A.; Kartzikos, S. [Physics Department, Aristotle University of Thessaloniki (Greece); Niksic, T.; Paar, N.; Vretenar, D. [Physics Department, University of Zagreb (Croatia); Ring, P. [Physics Department, TU Muenchen, Garching (Germany)

2009-08-26T23:59:59.000Z

116

A High Density Polarized Hydrogen Gas Target for Storage Rings  

E-Print Network [OSTI]

A High Density Polarized Hydrogen Gas Target for Storage Rings K. Zapfe \\Lambday , B. Braun z , H of gaseous polarized hydrogen was formed by injecting polarized H atoms (produced by Stern­Gerlach spin separation) into a storage cell consisting of a cylindrical tube open at both ends. The target was placed

117

Direct hydrocarbon fuel cells  

DOE Patents [OSTI]

The direct electrochemical oxidation of hydrocarbons in solid oxide fuel cells, to generate greater power densities at lower temperatures without carbon deposition. The performance obtained is comparable to that of fuel cells used for hydrogen, and is achieved by using novel anode composites at low operating temperatures. Such solid oxide fuel cells, regardless of fuel source or operation, can be configured advantageously using the structural geometries of this invention.

Barnett, Scott A.; Lai, Tammy; Liu, Jiang

2010-05-04T23:59:59.000Z

118

Intercrystalline density on nanocrystalline nickel  

SciTech Connect (OSTI)

Most methods currently available for the synthesis of nanostructured materials result in considerable residual porosity. Studies concerned with the novel structures and properties of these materials are thus compromised by the intrinsically high levels of porosity. As recently shown by Kristic et al., porosity can have a significant effect on fundamental materials properties such as Young`s modulus. One of the most promising techniques for the production of fully dense nanocrystalline materials is electrodeposition. In the present work, the residual porosity and density of nanostructured nickel produced by the electrodeposition method is assessed and discussed in light of the intrinsic intercrystalline density of nickel.

Haasz, T.R.; Aust, K.T. [Univ. of Toronto, Ontario (Canada). Dept. of Metallurgy and Materials Science] [Univ. of Toronto, Ontario (Canada). Dept. of Metallurgy and Materials Science; Palumbo, G. [Ontario Hydro Research Div., Toronto, Ontario (Canada)] [Ontario Hydro Research Div., Toronto, Ontario (Canada); El-Sherik, A.M.; Erb, U. [Queen`s Univ., Kingston, Ontario (Canada). Dept. of Materials and Metallurgical Engineering] [Queen`s Univ., Kingston, Ontario (Canada). Dept. of Materials and Metallurgical Engineering

1995-02-01T23:59:59.000Z

119

Intracellular Water Exchange for Measuring the Dry Mass, Water Mass and Changes in Chemical Composition of Living Cells  

E-Print Network [OSTI]

We present a method for direct non-optical quantification of dry mass, dry density and water mass of single living cells in suspension. Dry mass and dry density are obtained simultaneously by measuring a cell’s buoyant ...

Cermak, Nathan

120

Time Dependent Density Functional Theory An introduction  

E-Print Network [OSTI]

Time Dependent Density Functional Theory An introduction Francesco Sottile LSI, Ecole Polytechnique (ETSF) Time Dependent Density Functional Theory Palaiseau, 7 February 2012 1 / 32 #12;Outline 1 Frontiers 4 Perspectives and Resources Francesco Sottile (ETSF) Time Dependent Density Functional Theory

Botti, Silvana

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While these samples are representative of the content of NLEBeta,
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We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Time Dependent Density Functional Theory An Introduction  

E-Print Network [OSTI]

Time Dependent Density Functional Theory An Introduction Francesco Sottile Laboratoire des Solides) Belfast, 29 Jun 2007 Time Dependent Density Functional Theory Francesco Sottile #12;Intro Formalism Dependent Density Functional Theory Francesco Sottile #12;Intro Formalism Results Resources Outline 1

Botti, Silvana

122

Statistical density modification using local pattern matching  

DOE Patents [OSTI]

A computer implemented method modifies an experimental electron density map. A set of selected known experimental and model electron density maps is provided and standard templates of electron density are created from the selected experimental and model electron density maps by clustering and averaging values of electron density in a spherical region about each point in a grid that defines each selected known experimental and model electron density maps. Histograms are also created from the selected experimental and model electron density maps that relate the value of electron density at the center of each of the spherical regions to a correlation coefficient of a density surrounding each corresponding grid point in each one of the standard templates. The standard templates and the histograms are applied to grid points on the experimental electron density map to form new estimates of electron density at each grid point in the experimental electron density map.

Terwilliger, Thomas C.

2007-01-23T23:59:59.000Z

123

Molecular Structures of Polymer/Sulfur Composites for Lithium...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Structures of PolymerSulfur Composites for Lithium-Sulfur Batteries with Long Cycle Life. Molecular Structures of PolymerSulfur Composites for Lithium-Sulfur Batteries with Long...

124

Controlled Nucleation and Growth Process of Li2S2/Li2S in Lithium...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

and Growth Process of Li2S2Li2S in Lithium-Sulfur Batteries. Abstract: Lithium-sulfur battery is a promising next-generation energy storage system because of its potentially...

125

Open problems in nuclear density functional theory  

E-Print Network [OSTI]

This note describes five subjects of some interest for the density functional theory in nuclear physics. These are, respectively, i) the need for concave functionals, ii) the nature of the Kohn-Sham potential for the radial density theory, iii) a proper implementation of a density functional for an "intrinsic" rotational density, iv) the possible existence of a potential driving the square root of the density, and v) the existence of many models where a density functional can be explicitly constructed.

B. G. Giraud

2009-11-30T23:59:59.000Z

126

Transformations for densities Linear transformations  

E-Print Network [OSTI]

' & $ % Lecture 28 Transformations for densities Linear transformations 1-1 differentiable functions General transformations Expectation of a function 1 #12;' & $ % Transformations for discrete transformation of a U[0, 1] · Take X U[0, 1], so that fX(x) = 1 0 0 and set Y

Adler, Robert J.

127

The effects of chemical pressurization on screen electrode fuel cells  

E-Print Network [OSTI]

A large amount of fuel cell research focuses on porous gas diffusion (PGD) fuel cells which currently produce the best power density. However, this sect of fuel cell technology has many obstacles to overcome before becoming ...

Ahmed, Ali, S.B. Massachusetts Institute of Technology

2007-01-01T23:59:59.000Z

128

Nuclear Density Functional Theory and the Equation of State  

E-Print Network [OSTI]

A nuclear density functional can be used to find the binding energy and shell structure of nuclei and the energy gap in superconducting nuclear matter. In this paper, we study the possible application of a nuclear density functional theory to nuclear astrophysics. From energy density functional theory, we can deduce the interaction between nucleons to find a rough estimate of the charge radius of the specific nuclei. Compared to the Finite-Range Thomas Fermi model, we include three-body forces, which might be important at densities several times that of nuclear matter density. We also add the momentum dependent interaction to take into account the effective mass of the nucleons. We study matter in the neutron star crust using the Wigner-Seitz cell method. By constructing the mass-radius relation of neutron stars and investigating lepton-rich nuclear matter in proto-neutron stars, we find that the density functional can be used to construct an equation of state of hot dense matter.

Yeunhwan Lim

2011-04-06T23:59:59.000Z

129

Detailed Studies of a HighDensity Polarized Hydrogen Gas Target for Storage Rings  

E-Print Network [OSTI]

Detailed Studies of a High­Density Polarized Hydrogen Gas Target for Storage Rings Kirsten Zapfe 1 (1996) 293 Abstract A high­density target of polarized atomic hydrogen gas for applications in storage rings was produced by injecting atoms from an atomic beam source into a T­shaped storage cell

130

High energy density micro plasma bunch from multiple laser interaction with thin target  

SciTech Connect (OSTI)

Three-dimensional particle-in-cell simulation is used to investigate radiation-pressure driven acceleration and compression of small solid-density plasma by intense laser pulses. It is found that multiple impacts by presently available short-pulse lasers on a small hemispheric shell target can create a long-living tiny quasineutral monoenergetic plasma bunch of very high energy density.

Xu, Han [National Laboratory for Parallel and Distributed Processing, College of Computer Science, National University of Defense Technology, Changsha 410073 (China); Shanghai Institute of Optics and Fine Mechanics, Shanghai 201800 (China); Yu, Wei; Luan, S. X.; Xu, Z. Z. [Shanghai Institute of Optics and Fine Mechanics, Shanghai 201800 (China); Yu, M. Y., E-mail: myyu@zju.edu.cn [Physics Department, Institute for Fusion Theory and Simulation, Zhejiang University, Hangzhou 310027 (China); Institute for Theoretical Physics I, Ruhr University, Bochum D-44780 (Germany); Cai, H. B.; Zhou, C. T. [Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China); Yang, X. H.; Yin, Y.; Zhuo, H. B. [College of Science, National University of Defense Technology, Changsha (China); Wang, J. W. [Shanghai Institute of Optics and Fine Mechanics, Shanghai 201800 (China); Institute of Laser Engineering, Osaka University, Osaka 565-0871 (Japan); Murakami, M. [Institute of Laser Engineering, Osaka University, Osaka 565-0871 (Japan)

2014-01-13T23:59:59.000Z

131

Jacek Dobaczewski Density functional theory and energy  

E-Print Network [OSTI]

Jacek Dobaczewski Density functional theory and energy density functionals in nuclear physics Jacek Functional #12;Jacek Dobaczewski Mean-Field Theory Density Functional Theory · mean-field one? Density Functional Theory: A variational method that uses observables as variational parameters. #12;Jacek

Dobaczewski, Jacek

132

Density Functional Theory (DFT) Rob Parrish  

E-Print Network [OSTI]

Density Functional Theory (DFT) Rob Parrish robparrish@gmail.com 1 #12;Agenda · The mechanism Easy to do this Why? Because of Hermitian Operators: Kinetic Energy Density: #12;Density Functional The density completely defines the observable state of the system: The way in which it does so (the functional

Sherrill, David

133

A current density distribution tool  

E-Print Network [OSTI]

. I. INTRODUCTION Current density distribution is an important consideration for those involved in electrochemical systems and electroplating in particular. In the printed wiring board (PWB) business, great emphasis is placed on the study of current... exist. Numerical techniques on the other hand, are usually easy to implement and are easily applicable to microcomputers. Their disadvantage as with any approximation technique is that the exactness of the results with This document follows the style...

Jagush, Frederic A.

1989-01-01T23:59:59.000Z

134

Cell Analysis ? High-Energy Density Cathodes and Anodes  

Broader source: Energy.gov (indexed) [DOE]

does not contain any proprietary, confidential, or otherwise restricted information LBNL Project ID: ES053 OVERVIEW Timeline * PI Joined BATT 2001 * Cathodes Task Started 2001...

135

Stable laser–plasma accelerators at low densities  

SciTech Connect (OSTI)

We report stable laser wakefield acceleration using 17–50 TW laser pulses interacting with 4?mm-long helium gas jet. The initial laser spot size was relatively large (28??m) and the plasma densities were 0.48–2.0?×?10{sup 19?}cm{sup ?3}. High-quality 100–MeV electron beams were generated at the plasma density of 7.5?×?10{sup 18?}cm{sup ?3}, at which the beam parameters (pointing angle, energy spectrum, charge, and divergence angle) were measured and stabilized. At higher densities, filamentation instability of the laser-plasma interaction was observed and it has led to multiple wakefield accelerated electron beams. The experimental results are supported by 2D particle-in-cell simulations. The achievement presented here is an important step toward the use of laser-driven accelerators in real applications.

Li, Song; Hafz, Nasr A. M., E-mail: nasr@sjtu.edu.cn; Mirzaie, Mohammad; Ge, Xulei; Sokollik, Thomas; Chen, Min; Sheng, Zhengming; Zhang, Jie, E-mail: jzhang1@sjtu.edu.cn [Key Laboratory for Laser Plasmas (Ministry of Education) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China)

2014-07-28T23:59:59.000Z

136

Probability distribution of the vacuum energy density  

SciTech Connect (OSTI)

As the vacuum state of a quantum field is not an eigenstate of the Hamiltonian density, the vacuum energy density can be represented as a random variable. We present an analytical calculation of the probability distribution of the vacuum energy density for real and complex massless scalar fields in Minkowski space. The obtained probability distributions are broad and the vacuum expectation value of the Hamiltonian density is not fully representative of the vacuum energy density.

Duplancic, Goran; Stefancic, Hrvoje [Theoretical Physics Division, Rudjer Boskovic Institute, P.O. Box 180, HR-10002 Zagreb (Croatia); Glavan, Drazen [Department of Physics, Faculty of Science, University of Zagreb, P.O. Box 331, HR-10002 Zagreb (Croatia)

2010-12-15T23:59:59.000Z

137

Proposed method for high-speed plasma density measurement in proton-driven plasma wakefield acceleration  

SciTech Connect (OSTI)

Recently a proton-bunch-driven plasma wakefield acceleration experiment using the CERN-SPS beam was proposed. Different types of plasma cells are under study, especially laser ionization, plasma discharge, and helicon sources. One of the key parameters is the spatial uniformity of the plasma density profile along the cell that has to be within < 1% of the nominal density (6 Multiplication-Sign 10{sup 14} cm{sup -3}). Here a setup based on a photomixing concept is proposed to measure the plasma cut-off frequency and determine the plasma density.

Tarkeshian, R.; Reimann, O.; Muggli, P. [Max-Planck-Institut fuer Physik, 80805 Munich (Germany)

2012-12-21T23:59:59.000Z

138

E-Print Network 3.0 - a549 cells exposed Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

at Berkeley Collection: Biology and Medicine 47 Hydralazine Rescues PC12 Cells From Acrolein-Mediated Death Summary: JP. 1997. Relationships between cell density, glutathione and...

139

Density functional theory of electrowetting  

E-Print Network [OSTI]

The phenomenon of electrowetting, i.e., the dependence of the macroscopic contact angle of a fluid on the electrostatic potential of the substrate, is analyzed in terms of the density functional theory of wetting. It is shown that electrowetting is not an electrocapillarity effect, i.e., it cannot be consistently understood in terms of the variation of the substrate-fluid interfacial tension with the electrostatic substrate potential, but it is related to the depth of the effective interface potential. The key feature, which has been overlooked so far and which occurs naturally in the density functional approach is the structural change of a fluid if it is brought into contact with another fluid. These structural changes occur in the present context as the formation of finite films of one fluid phase in between the substrate and the bulk of the other fluid phase. The non-vanishing Donnan potentials (Galvani potential differences) across such film-bulk fluid interfaces, which generically occur due to an unequal partitioning of ions as a result of differences of solubility contrasts, lead to correction terms in the electrowetting equation, which become relevant for sufficiently small substrate potentials. Whereas the present density functional approach confirms the commonly used electrocapillarity-based electrowetting equation as a good approximation for the cases of metallic electrodes or electrodes coated with a hydrophobic dielectric in contact with an electrolyte solution and an ion-free oil, a significantly reduced tendency for electrowetting is predicted for electrodes coated with a dielectric which is hydrophilic or which is in contact with two immiscible electrolyte solutions.

Markus Bier; Ingrid Ibagon

2014-02-10T23:59:59.000Z

140

Affine maps of density matrices  

E-Print Network [OSTI]

For quantum systems described by finite matrices, linear and affine maps of matrices are shown to provide equivalent descriptions of evolution of density matrices for a subsystem caused by unitary Hamiltonian evolution in a larger system; an affine map can be replaced by a linear map, and a linear map can be replaced by an affine map. There may be significant advantage in using an affine map. The linear map is generally not completely positive, but the linear part of an equivalent affine map can be chosen to be completely positive and related in the simplest possible way to the unitary Hamiltonian evolution in the larger system.

Thomas F. Jordan

2004-11-21T23:59:59.000Z

Note: This page contains sample records for the topic "density lithium-sulfur cells" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Combining Density Functional Theory and Density Matrix Functional Theory Daniel R. Rohr1  

E-Print Network [OSTI]

Combining Density Functional Theory and Density Matrix Functional Theory Daniel R. Rohr1 , Julien and CNRS, 4 place Jussieu, 75252 Paris, France We combine density-functional theory with density cleavage is an ubiquitous process for chemistry. Density-matrix functional theory (DMFT) (see, e.g., Refs

Paris-Sud XI, Université de

142

High density behaviour of nuclear symmetry energy  

E-Print Network [OSTI]

Role of the isospin asymmetry in nuclei and neutron stars, with an emphasis on the density dependence of the nuclear symmetry energy, is discussed. The symmetry energy is obtained using the isoscalar as well as isovector components of the density dependent M3Y effective interaction. The constants of density dependence of the effective interaction are obtained by reproducing the saturation energy per nucleon and the saturation density of spin and isospin symmetric cold infinite nuclear matter. Implications for the density dependence of the symmetry energy in case of a neutron star are discussed, and also possible constraints on the density dependence obtained from finite nuclei are compared.

D. N. Basu; Tapan Mukhopadhyay

2006-12-27T23:59:59.000Z

143

Risk Bounds for Mixture Density Estimation  

E-Print Network [OSTI]

In this paper we focus on the problem of estimating a bounded density using a finite combination of densities from a given class. We consider the Maximum Likelihood Procedure (MLE) and the greedy procedure described by ...

Rakhlin, Alexander

2004-01-27T23:59:59.000Z

144

apud cells: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

on hydrogen rich mixtures best Hydrogen rich leads to highest power density in fuel cell Cost of SOFC is high, lower cost SOFC system is potentially highest power density...

145

abaxial cell developmentwoa: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

on hydrogen rich mixtures best Hydrogen rich leads to highest power density in fuel cell Cost of SOFC is high, lower cost SOFC system is potentially highest power density...

146

adenoma cell systems: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

on hydrogen rich mixtures best Hydrogen rich leads to highest power density in fuel cell Cost of SOFC is high, lower cost SOFC system is potentially highest power density...

147

Quantum critical benchmark for density functional theory  

E-Print Network [OSTI]

Two electrons at the threshold of ionization represent a severe test case for electronic structure theory. A pseudospectral method yields a very accurate density of the two-electron ion with nuclear charge close to the critical value. Highly accurate energy components and potentials of Kohn-Sham density functional theory are given, as well as a useful parametrization of the critical density. The challenges for density functional approximations and the strength of correlation are also discussed.

Paul E. Grabowski; Kieron Burke

2014-08-09T23:59:59.000Z

148

Laboratory testing of high energy density capacitors for electric vehicles  

SciTech Connect (OSTI)

Laboratory tests of advanced, high energy density capacitors in the Battery Test Laboratory of the Idaho National Engineering Laboratory have been performed to investigate their suitability for load-leveling the battery in an electric vehicle. Two types of devices were tested -- 3 V, 70 Farad, spiral wound, carbon-based, single cell devices and 20 V, 3. 5 Farad, mixed-oxide, multi-cell bipolar devices. The energy density of the devices, based on energy stored during charge to the rated voltage, was found to be 1--2 Wh/kg, which agreed well with that claimed by the manufacturers. Constant power discharge tests were performed at power densities up to 1500 W/kg. Discharges at higher power densities could have been performed had equipment been available to maintain constant power during discharges of less than one second. It was found that the capacitance of the devices were rate dependent with the rate dependency of the carbon-based devices being higher than that of the mixed-oxide devices. The resistance of both types of devices were relatively low being 20--30 milliohms. Testing done in the study showed that the advanced high energy density capacitors can be charged and discharged over cycles (PSFUDS) which approximate the duty cycle that would be encountered if the devices are used to load-level the battery in an electric vehicle. Thermal tests of the advanced capacitors in an insulated environment using the PSFUDS cycle showed the devices do not overheat with their temperatures increasing only 4--5{degrees}C for tests that lasted 5--7 hours. 7 refs., 33 figs., 11 tabs.

Burke, A.F.

1991-10-01T23:59:59.000Z

149

Oxides having high energy densities  

DOE Patents [OSTI]

Certain disclosed embodiments generally relate to oxide materials having relatively high energy and/or power densities. Various aspects of the embodiments are directed to oxide materials having a structure B.sub.i(M.sub.jY.sub.k)O.sub.2, for example, a structure Li.sub.j(Ni.sub.jY.sub.k)O.sub.2 such as Li(Ni.sub.0.5Mn.sub.0.5)O.sub.2. In this structure, Y represents one or more atoms, each independently selected from the group consisting of alkaline earth metals, transition metals, Group 14 elements, Group 15, or Group 16 elements. In some embodiments, such an oxide material may have an O3 crystal structure, and/or a layered structure such that the oxide comprises a plurality of first, repeating atomic planes comprising Li, and a plurality of second, repeating atomic planes comprising Ni and/or Y.

Ceder, Gerbrand; Kang, Kisuk

2013-09-10T23:59:59.000Z

150

The Critical Density and the Effective Excitation Density of Commonly Observed Molecular Dense Gas Tracers  

E-Print Network [OSTI]

The optically thin critical densities and the effective excitation densities to produce a 1 K km/s (or 0.818 Jy km/s $(\\frac{\

Shirley, Yancy L

2015-01-01T23:59:59.000Z

151

Density Functional Theory Models for Radiation Damage  

E-Print Network [OSTI]

Density Functional Theory Models for Radiation Damage S.L. Dudarev EURATOM/CCFE Fusion Association, DFT Abstract Density functional theory models developed over the past decade provide unique phenomena. Density functional theory models have effectively created a new paradigm for the scientific

152

Time Dependent Density Functional Theory An introduction  

E-Print Network [OSTI]

Time Dependent Density Functional Theory An introduction Francesco Sottile LSI, Ecole Polytechnique) Time Dependent Density Functional Theory Palaiseau, 26 May 2014 1 / 62 #12;Outline 1 Introduction: why and Resources Francesco Sottile (ETSF) Time Dependent Density Functional Theory Palaiseau, 26 May 2014 2 / 62

Botti, Silvana

153

DENSITY FUNCTIONAL THEORY OF FIELD THEORETICAL SYSTEMS  

E-Print Network [OSTI]

DENSITY FUNCTIONAL THEORY OF FIELD THEORETICAL SYSTEMS E. Engel Inst. fur Theor. Physik background of relativistic density functional theory is emphasized and its consequences for relativistic Kohn-Sham equations are shown. The local density approximation for the exchange energy functional is reviewed

Engel, Eberhard

154

Density functional theory George F. Bertsch  

E-Print Network [OSTI]

Density functional theory George F. Bertsch #3; Institute for Nuclear Theory and Department of Physics University of Tsukuba Tsukuba 305-8577 Japan Abstract Density functional theory is a remarkably Time-dependent density functional theory: the equations 34 A Optical properties

Bertsch George F.

155

DENSITY FUNCTIONAL THEORY, THE MODERN TREATMENT OF  

E-Print Network [OSTI]

DENSITY FUNCTIONAL THEORY, THE MODERN TREATMENT OF ELECTRON CORRELATIONS E.K.U. Gross and Stefan The basic idea of density functional theory is to describe a many-electron system exclusively and completely-consistent scheme, known as the Kohn-Sham scheme [2], is the heart of modern density functional theory

Gross, E.K.U.

156

Aerodynamic Focusing Of High-Density Aerosols  

SciTech Connect (OSTI)

High-density micron-sized particle aerosols might form the basis for a number of applications in which a material target with a particular shape might be quickly ionized to form a cylindrical or sheet shaped plasma. A simple experimental device was built in order to study the properties of high-density aerosol focusing for 1#22; m silica spheres. Preliminary results recover previous findings on aerodynamic focusing at low densities. At higher densities, it is demonstrated that the focusing properties change in a way which is consistent with a density dependent Stokes number.

Ruiz, D. E.; Fisch, Nathaniel

2014-02-24T23:59:59.000Z

157

KH Computational Physics-2009 Density Functional Theory (DFT) Density Functional Theory  

E-Print Network [OSTI]

KH Computational Physics- 2009 Density Functional Theory (DFT) Density Functional Theory of interacting particles. Kristjan Haule, 2009 ­2­ #12;KH Computational Physics- 2009 Density Functional Theory functional of n. Kristjan Haule, 2009 ­3­ #12;KH Computational Physics- 2009 Density Functional Theory (DFT

Haule, Kristjan

158

Density-functional theory of nonuniform classical liquids: An extended modified weighted-density approximation  

E-Print Network [OSTI]

Density-functional theory of nonuniform classical liquids: An extended modified weighted-density the approximationstreat long-rangeand short-rangepotentials. I. INTRODUCTION The density-functional theory of nonuniform of density- functional theory to the problem of freezing of classical liquids,4 and in particular

Likos, Christos N.

159

Population Density Population density (persons per square kilometer) layers, for 1990  

E-Print Network [OSTI]

Population Density Africa Population density (persons per square kilometer) layers, for 1990 the 12 population density classes. Source information: http://sedac.ciesin.columbia.edu/gpw/. ´ Robinson://sedac.ciesin.columbia.edu/place/ Publish Date: 03/13/07 0 1,000 km Population Density 2000 0 Persons \\ Sq.Km 0-2 Persons \\ Sq.Km 2

Columbia University

160

Dot Density Maps Dot density maps, or dot maps, portray the geographic distribution of discrete phenomena  

E-Print Network [OSTI]

Dot Density Maps Dot density maps, or dot maps, portray the geographic distribution of discrete for representing geographic patterns. Dot density maps are particularly useful for understanding global distribution of the mapped phenomenon and comparing relative densities of different regions on the map. Dot

Klippel, Alexander

Note: This page contains sample records for the topic "density lithium-sulfur cells" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Ultra-low density microcellular polymer foam and method  

DOE Patents [OSTI]

An ultra-low density, microcellular open-celled polymer foam and a method for making such foam are disclosed. A polymer is dissolved in a heated solution consisting essentially of at least one solvent for the dissolution of the polymer in the heated solution and the phase inversion of the dissolved polymer to a liquid gel upon sufficient cooling of the heated solution. The heated solution is contained in a containment means provided with a nucleating promoting means having a relatively rough surface formed of fixed nucleating sites. The heated solution is cooled for a period of time sufficient to form a liquid gel of the polymer by phase inversion. From the gel, a porous foam having a density of less than about 12.0 mg/cm{sup 3} and open porosity provided by well interconnected strut morphology is formed.

Simandl, R.F.; Brown, J.D.

1996-03-19T23:59:59.000Z

162

Self-humidified proton exchange membrane fuel cells: Operation of larger cells and fuel cell stacks  

SciTech Connect (OSTI)

The PEM fuel cell is promising as the power source for use in mobile and stationary applications primarily because of its high power density, all solid components, and simplicity of operation. For wide acceptability of this power source, its cost has to be competitive with the presently available energy sources. The fuel cell requires continuous humidification during operation as a power source. The humidification unit however, increases fuel cell volume, weight, and therefore decreases its overall power density. Great advantages in terms of further fuel cell simplification can be achieved if the humidification process can be eliminated or minimized. In addition, cost reductions are associated with the case of manufacturing and operation. At BCS Technology we have developed a technology of self-humidified operation of PEM fuel cells based on the mass balance of the reactants and products and the ability of membrane electrode assembly (MEA) to retain water necessary for humidification under the cell operating conditions. The reactants enter the fuel cell chambers without carrying any form of water, whether in liquid or vapor form. Basic principles of self-humidified operation of fuel cells as practiced by BCS Technology, Inc. have been presented previously in literature. Here, we report the operation of larger self-humidified single cells and fuel cell stacks. Fuel cells of areas Up to 100 cm{sup 2} have been operated. We also show the self-humidified operation of fuel cell stacks of 50 and 100 cm{sup 2} electrode areas.

Dhar, H.P.; Lee, J.H.; Lewinski, K.A. [BCS Technology, Inc., Bryan, TX (United States)

1996-12-31T23:59:59.000Z

163

Quartz resonator fluid density and viscosity monitor  

DOE Patents [OSTI]

A pair of thickness-shear mode resonators, one smooth and one with a textured surface, allows fluid density and viscosity to be independently resolved. A textured surface, either randomly rough or regularly patterned, leads to trapping of liquid at the device surface. The synchronous motion of this trapped liquid with the oscillating device surface allows the device to weigh the liquid; this leads to an additional response that depends on liquid density. This additional response enables a pair of devices, one smooth and one textured, to independently resolve liquid density and viscosity; the difference in responses determines the density while the smooth device determines the density-viscosity product, and thus, the pair determines both density and viscosity.

Martin, Stephen J. (Albuquerque, NM); Wiczer, James J. (Albuquerque, NM); Cernosek, Richard W. (Albuquerque, NM); Frye, Gregory C. (Cedar Crest, NM); Gebert, Charles T. (Albuquerque, NM); Casaus, Leonard (Bernalillo, NM); Mitchell, Mary A. (Tijeras, NM)

1998-01-01T23:59:59.000Z

164

Considering Air Density in Wind Power Production  

E-Print Network [OSTI]

In the wind power production calculations the air density is usually considered as constant in time. Using the CIPM-2007 equation for the density of moist air as a function of air temperature, air pressure and relative humidity, we show that it is worth taking the variation of the air density into account, because higher accuracy can be obtained in the calculation of the power production for little effort.

Farkas, Zénó

2011-01-01T23:59:59.000Z

165

Considering Air Density in Wind Power Production  

E-Print Network [OSTI]

In the wind power production calculations the air density is usually considered as constant in time. Using the CIPM-2007 equation for the density of moist air as a function of air temperature, air pressure and relative humidity, we show that it is worth taking the variation of the air density into account, because higher accuracy can be obtained in the calculation of the power production for little effort.

Zénó Farkas

2011-03-11T23:59:59.000Z

166

Method of synthesizing a low density material  

DOE Patents [OSTI]

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.

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

1987-02-27T23:59:59.000Z

167

Betatron radiation from density tailored plasmas  

E-Print Network [OSTI]

Betatron radiation from density tailored plasmas K. Tathe resulting betatron radiation spectrum can therefore bepro?le, the betatron radiation emitted by theses electrons

Ta Phuoc, Kim

2010-01-01T23:59:59.000Z

168

Some challenges for Nuclear Density Functional Theory  

E-Print Network [OSTI]

We discuss some of the challenges that the DFT community faces in its quest for the truly universal energy density functional applicable over the entire nuclear chart.

T. Duguet; K. Bennaceur; T. Lesinski; J. Meyer

2006-06-20T23:59:59.000Z

169

3-D capacitance density imaging system  

DOE Patents [OSTI]

A three-dimensional capacitance density imaging of a gasified bed or the like in a containment vessel is achieved using a plurality of electrodes provided circumferentially about the bed in levels and along the bed in channels. The electrodes are individually and selectively excited electrically at each level to produce a plurality of current flux field patterns generated in the bed at each level. The current flux field patterns are suitably sensed and a density pattern of the bed at each level determined. By combining the determined density patterns at each level, a three-dimensional density image of the bed is achieved. 7 figs.

Fasching, G.E.

1988-03-18T23:59:59.000Z

170

Method for providing a low density high strength polyurethane foam  

DOE Patents [OSTI]

Disclosed is a method for making a polyurethane closed-cell foam material exhibiting a bulk density below 4 lbs/ft.sup.3 and high strength. The present embodiment uses the reaction product of a modified MDI and a sucrose/glycerine based polyether polyol resin wherein a small measured quantity of the polyol resin is "pre-reacted" with a larger quantity of the isocyanate in a defined ratio such that when the necessary remaining quantity of the polyol resin is added to the "pre-reacted" resin together with a tertiary amine catalyst and water as a blowing agent, the polymerization proceeds slowly enough to provide a stable foam body.

Whinnery, Jr., Leroy L.; Goods, Steven H.; Skala, Dawn M.; Henderson, Craig C.; Keifer, Patrick N.

2013-06-18T23:59:59.000Z

171

Mixing device for materials with large density differences  

DOE Patents [OSTI]

An auger-tube pump mixing device is disclosed for mixing materials with large density differences while maintaining low stirring RPM and low power consumption. The mixing device minimizes the formation of vortexes and minimizes the incorporation of small bubbles in the liquid during mixing. By avoiding the creation of a vortex the device provides efficient stirring of full containers without spillage over the edge. Also, the device solves the problem of effective mixing in vessels where the liquid height is large compared to the diameter. Because of the gentle stirring or mixing by the device, it has application for biomedical uses where cell damage is to be avoided. 2 figs.

Gregg, D.W.

1994-08-16T23:59:59.000Z

172

Mixing device for materials with large density differences  

DOE Patents [OSTI]

An auger-tube pump mixing device for mixing materials with large density differences while maintaining low stirring RPM and low power consumption. The mixing device minimizes the formation of vortexes and minimizes the incorporation of small bubbles in the liquid during mixing. By avoiding the creation of a vortex the device provides efficient stirring of full containers without spillage over the edge. Also, the device solves the problem of effective mixing in vessels where the liquid height is large compared to the diameter. Because of the gentle stirring or mixing by the device, it has application for biomedical uses where cell damage is to be avoided.

Gregg, David W. (Moraga, CA)

1994-01-01T23:59:59.000Z

173

Development of Large Format Lithium Ion Cells with Higher Energy...  

Broader source: Energy.gov (indexed) [DOE]

Hydrogen and Fuel Cells Program Review ES-127 Development of Large Format Lithium Ion Cells with Higher Energy Density Erin O'Driscoll (PI) Han Wu (Presenter) Dow Kokam May 13,...

174

aerial density profiles: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

present an analytic approach to predict gas density and temperature profiles in dark matter haloes. We assume that the gas density profile traces the dark matter density profile...

175

Compatibility and toxicity of polymer-coated magnetic nanoparticles on mammalian cell systems  

E-Print Network [OSTI]

(cont.) produced normal growth curves in the presence of particles. However, the particles do still exhibit some toxicity towards the cells, as the maximum cell density of cells cultured with particles does not reach that ...

Kral, Kelly M., 1979-

2005-01-01T23:59:59.000Z

176

High density laser-driven target  

DOE Patents [OSTI]

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.

Lindl, John D. (San Ramon, CA)

1981-01-01T23:59:59.000Z

177

Density Estimation Trees in High Energy Physics  

E-Print Network [OSTI]

Density Estimation Trees can play an important role in exploratory data analysis for multidimensional, multi-modal data models of large samples. I briefly discuss the algorithm, a self-optimization technique based on kernel density estimation, and some applications in High Energy Physics.

Anderlini, Lucio

2015-01-01T23:59:59.000Z

178

Density of Spray-Formed Materials  

SciTech Connect (OSTI)

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 conditions 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.

Kevin M. McHugh; Volker Uhlenwinkel; Nils Ellendr

2008-06-01T23:59:59.000Z

179

Density functional theory for carbon dioxide crystal  

SciTech Connect (OSTI)

We present a density functional approach to describe the solid?liquid phase transition, interfacial and crystal structure, and properties of polyatomic CO{sub 2}. Unlike previous phase field crystal model or density functional theory, which are derived from the second order direct correlation function, the present density functional approach is based on the fundamental measure theory for hard-sphere repulsion in solid. More importantly, the contributions of enthalpic interactions due to the dispersive attractions and of entropic interactions arising from the molecular architecture are integrated in the density functional model. Using the theoretical model, the predicted liquid and solid densities of CO{sub 2} at equilibrium triple point are in good agreement with the experimental values. Based on the structure of crystal-liquid interfaces in different planes, the corresponding interfacial tensions are predicted. Their respective accuracies need to be tested.

Chang, Yiwen; Mi, Jianguo, E-mail: mijg@mail.buct.edu.cn; Zhong, Chongli [State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (China)

2014-05-28T23:59:59.000Z

180

Neutral depletion and the helicon density limit  

SciTech Connect (OSTI)

It is straightforward to create fully ionized plasmas with modest rf power in a helicon. It is difficult, however, to create plasmas with density >10{sup 20} m{sup ?3}, because neutral depletion leads to a lack of fuel. In order to address this density limit, we present fast (1 MHz), time-resolved measurements of the neutral density at and downstream from the rf antenna in krypton helicon plasmas. At the start of the discharge, the neutral density underneath the antenna is reduced to 1% of its initial value in 15 ?s. The ionization rate inferred from these data implies that the electron temperature near the antenna is much higher than the electron temperature measured downstream. Neutral density measurements made downstream from the antenna show much slower depletion, requiring 14 ms to decrease by a factor of 1/e. Furthermore, the downstream depletion appears to be due to neutral pumping rather than ionization.

Magee, R. M.; Galante, M. E.; Carr, J. Jr.; Lusk, G.; McCarren, D. W.; Scime, E. E. [West Virginia University, Morgantown, West Virginia 26506 (United States)] [West Virginia University, Morgantown, West Virginia 26506 (United States)

2013-12-15T23:59:59.000Z

Note: This page contains sample records for the topic "density lithium-sulfur cells" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

How to Calculate Molecular Column Density  

E-Print Network [OSTI]

The calculation of the molecular column density from molecular spectral (rotational or ro-vibrational) transition measurements is one of the most basic quantities derived from molecular spectroscopy. Starting from first principles where we describe the basic physics behind the radiative and collisional excitation of molecules and the radiative transfer of their emission, we derive a general expression for the molecular column density. As the calculation of the molecular column density involves a knowledge of the molecular energy level degeneracies, rotational partition functions, dipole moment matrix elements, and line strengths, we include generalized derivations of these molecule-specific quantities. Given that approximations to the column density equation are often useful, we explore the optically thin, optically thick, and low-frequency limits to our derived general molecular column density relation. We also evaluate the limitations of the common assumption that the molecular excitation temperature is con...

Mangum, Jeffrey G

2015-01-01T23:59:59.000Z

182

Ions in solution: Density corrected density functional theory (DC-DFT)  

SciTech Connect (OSTI)

Standard density functional approximations often give questionable results for odd-electron radical complexes, with the error typically attributed to self-interaction. In density corrected density functional theory (DC-DFT), certain classes of density functional theory calculations are significantly improved by using densities more accurate than the self-consistent densities. We discuss how to identify such cases, and how DC-DFT applies more generally. To illustrate, we calculate potential energy surfaces of HO·Cl{sup ?} and HO·H{sub 2}O complexes using various common approximate functionals, with and without this density correction. Commonly used approximations yield wrongly shaped surfaces and/or incorrect minima when calculated self consistently, while yielding almost identical shapes and minima when density corrected. This improvement is retained even in the presence of implicit solvent.

Kim, Min-Cheol; Sim, Eunji, E-mail: esim@yonsei.ac.kr [Department of Chemistry and Institute of Nano-Bio Molecular Assemblies, Yonsei University, 50 Yonsei-ro Seodaemun-gu, Seoul 120-749 (Korea, Republic of)] [Department of Chemistry and Institute of Nano-Bio Molecular Assemblies, Yonsei University, 50 Yonsei-ro Seodaemun-gu, Seoul 120-749 (Korea, Republic of); Burke, Kieron [Department of Chemistry, University of California, Irvine, California 92697 (United States)] [Department of Chemistry, University of California, Irvine, California 92697 (United States)

2014-05-14T23:59:59.000Z

183

Wood density measurement protocol J Chave Page 1 Measuring wood density for tropical forest trees  

E-Print Network [OSTI]

Wood density measurement protocol ­ J Chave Page 1 Measuring wood density for tropical forest trees Diversité Biologique Université Paul Sabatier 31000 Toulouse, France 1. Introduction Wood is a biological, that transport the sap along the stem and they are filled by water. The density of tree wood is an interesting

Chave, Jérôme

184

Testing the kinetic energy functional: Kinetic energy density as a density functional  

E-Print Network [OSTI]

is to the exchange-correlation energy as a functional of the density. A large part of the total energy, the kinetic contexts. For finite systems these forms integrate to the same global ki- netic energy, but they differTesting the kinetic energy functional: Kinetic energy density as a density functional Eunji Sim

Burke, Kieron

185

Durability of Solid Oxide Electrolysis Cells for Hydrogen Production  

E-Print Network [OSTI]

that have been optimized for fuel cell operation but applied for HTES. The SOCs are produced on a pre Jensen, Sune Dalgaard Ebbesen, Mogens Mogensen Fuel Cells and Solid State Chemistry Department Risoe: Kinetics of a Risoe SOC working as an electrolyser cell (negative current densities i) and as a fuel cell

186

CHALLENGES IN DEVELOPMENT AND OPERATION OF MEMS MICROBIAL FUEL CELLS  

E-Print Network [OSTI]

CHALLENGES IN DEVELOPMENT AND OPERATION OF MEMS MICROBIAL FUEL CELLS A. Fraiwan1 , S. Sundermier1 Microbial Fuel Cells, Micro-sized, Power Density, Limiting Factors INTRODUCTION Microbial fuel cells (MFCs fuel cells (MFCs) have been a major focus for renewable energy production. With the successful

Steckl, Andrew J.

187

Periodic subsystem density-functional theory  

SciTech Connect (OSTI)

By partitioning the electron density into subsystem contributions, the Frozen Density Embedding (FDE) formulation of subsystem Density Functional Theory (DFT) has recently emerged as a powerful tool for reducing the computational scaling of Kohn–Sham DFT. To date, however, FDE has been employed to molecular systems only. Periodic systems, such as metals, semiconductors, and other crystalline solids have been outside the applicability of FDE, mostly because of the lack of a periodic FDE implementation. To fill this gap, in this work we aim at extending FDE to treat subsystems of molecular and periodic character. This goal is achieved by a dual approach. On one side, the development of a theoretical framework for periodic subsystem DFT. On the other, the realization of the method into a parallel computer code. We find that periodic FDE is capable of reproducing total electron densities and (to a lesser extent) also interaction energies of molecular systems weakly interacting with metallic surfaces. In the pilot calculations considered, we find that FDE fails in those cases where there is appreciable density overlap between the subsystems. Conversely, we find FDE to be in semiquantitative agreement with Kohn–Sham DFT when the inter-subsystem density overlap is low. We also conclude that to make FDE a suitable method for describing molecular adsorption at surfaces, kinetic energy density functionals that go beyond the GGA level must be employed.

Genova, Alessandro; Pavanello, Michele, E-mail: m.pavanello@rutgers.edu [Department of Chemistry, Rutgers University, Newark, New Jersey 07102 (United States); Ceresoli, Davide [Department of Chemistry, Rutgers University, Newark, New Jersey 07102 (United States); CNR-ISTM, Institute of Molecular Sciences and Technologies, Milano (Italy)

2014-11-07T23:59:59.000Z

188

Density Prediction of Uranium-6 Niobium Ingots  

SciTech Connect (OSTI)

The densities of uranium-6 niobium (U-Nb) alloys have been compiled from a variety of literature sources such as Y-12 and Rocky Flats datasheets. We also took advantage of the 42 well-pedigreed, homogeneous baseline U-Nb alloys produced under the Enhanced Surveillance Program for density measurements. Even though U-Nb alloys undergo two-phase transitions as the Nb content varies from 0 wt. % to 8 wt %, the theoretical and measured densities vary linearly with Nb content. Therefore, the effect of Nb content on the density was modeled with a linear regression. From this linear regression, a homogeneous ingot of U-6 wt.% Nb would have a density of 17.382 {+-} 0.040 g/cc (95% CI). However, ingots produced at Y-12 are not homogeneous with respect to the Nb content. Therefore, using the 95% confidence intervals, the density of a Y-12 produced ingot would vary from 17.310 {+-} 0.043 g/cc at the center to 17.432 {+-} 0.039 g/cc at the edge. Ingots with larger Nb inhomogeneities will also have larger variances in the density.

D.F.Teter; P.K. Tubesing; D.J.Thoma; E.J.Peterson

2003-04-15T23:59:59.000Z

189

The temperature dependence of equilibrium plasma density  

E-Print Network [OSTI]

Temperature dependence of an electron-nuclear plasma equilibrium density is considered basing on known approaches, which are given in (1)(2). It is shown that at a very high temperature, which is characteristic for a star interior, the equilibrium plasma density is almost constant and equals approximately to $10^{25}$ particles per $cm^3$. At a relatively low temperature, which is characteristic for star surface, the equilibrium plasma density is in several orders lower and depends on temperature as $T^{3/2}$.

B. V. Vasiliev

2002-03-17T23:59:59.000Z

190

Instabilities in the Nuclear Energy Density Functional  

E-Print Network [OSTI]

In the field of Energy Density Functionals (EDF) used in nuclear structure and dynamics, one of the unsolved issues is the stability of the functional. Numerical issues aside, some EDFs are unstable with respect to particular perturbations of the nuclear ground-state density. The aim of this contribution is to raise questions about the origin and nature of these instabilities, the techniques used to diagnose and prevent them, and the domain of density functions in which one should expect a nuclear EDF to be stable.

M. Kortelainen; T. Lesinski

2010-02-05T23:59:59.000Z

191

Corrugated Membrane Fuel Cell Structures  

SciTech Connect (OSTI)

One of the most challenging aspects of traditional PEM fuel cell stacks is the difficulty achieving the platinum catalyst utilization target of 0.2 gPt/kWe set forth by the DOE. Good catalyst utilization can be achieved with state-of-the-art catalyst coated membranes (CCM) when low catalyst loadings (<0.3 mg/cm2) are used at a low current. However, when low platinum loadings are used, the peak power density is lower than conventional loadings, requiring a larger total active area and a larger bipolar plate. This results in a lower overall stack power density not meeting the DOE target. By corrugating the fuel cell membrane electrode structure, Ion Power?s goal is to realize both the Pt utilization targets as well as the power density targets of the DOE. This will be achieved by demonstrating a fuel cell single cell (50 cm2) with a twofold increase in the membrane active area over the geometric area of the cell by corrugating the MEA structure. The corrugating structure must be able to demonstrate the target properties of < 10 mOhm-cm2 electrical resistance at > 20 psi compressive strength over the active area, in combination with offering at least 80% of power density that can be achieved by using the same MEA in a flat plate structure. Corrugated membrane fuel cell structures also have the potential to meet DOE power density targets by essentially packaging more membrane area into the same fuel cell volume as compared to conventional stack constructions.

Grot, Stephen [President, Ion Power Inc.] President, Ion Power Inc.

2013-09-30T23:59:59.000Z

192

Shock compression of low-density foams  

SciTech Connect (OSTI)

Shock compression of very low density micro-cellular materials allows entirely new regimes of hot fluid states to be investigated experimentally. Using a two-stage light-gas gun to generate strong shocks, temperatures of several eV are readily achieved at densities of roughly 0.5--1 g/cm{sup 3} in large, uniform volumes. The conditions in these hot, expanded fluids are readily found using the Hugoniot jump conditions. We will briefly describe the basic methodology for sample preparation and experimental measurement of shock velocities. We present data for several materials over a range of initial densities. This paper will explore the applications of these methods for investigations of equations of state and phase diagrams, spectroscopy, and plasma physics. Finally, we discus the need for future work on these and related low-density materials.

Holmes, N.C.

1993-07-01T23:59:59.000Z

193

Breast Density and Cancer | GE Global Research  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Breast Cancer Awareness Series: Understanding Breast Density Click to email this to a friend (Opens in new window) Share on Facebook (Opens in new window) Click to share (Opens in...

194

Magnetic fields and density functional theory  

SciTech Connect (OSTI)

A major focus of this dissertation is the development of functionals for the magnetic susceptibility and the chemical shielding within the context of magnetic field density functional theory (BDFT). These functionals depend on the electron density in the absence of the field, which is unlike any other treatment of these responses. There have been several advances made within this theory. The first of which is the development of local density functionals for chemical shieldings and magnetic susceptibilities. There are the first such functionals ever proposed. These parameters have been studied by constructing functionals for the current density and then using the Biot-Savart equations to obtain the responses. In order to examine the advantages and disadvantages of the local functionals, they were tested numerically on some small molecules.

Salsbury Jr., Freddie

1999-02-01T23:59:59.000Z

195

Separation of carbon nanotubes in density gradients  

DOE Patents [OSTI]

The separation of single-walled carbon nanotubes (SWNTs), by chirality and/or diameter, using centrifugation of compositions of SWNTs in and surface active components in density gradient media.

Hersam, Mark C. (Evanston, IL); Stupp, Samuel I. (Chicago, IL); Arnold, Michael S. (Northbrook, IL)

2012-02-07T23:59:59.000Z

196

Density controlled carbon nanotube array electrodes  

DOE Patents [OSTI]

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.

Ren, Zhifeng F. (Newton, MA); Tu, Yi (Belmont, MA)

2008-12-16T23:59:59.000Z

197

Separation of carbon nanotubes in density gradients  

DOE Patents [OSTI]

The separation of single-walled carbon nanotubes (SWNTs), by chirality and/or diameter, using centrifugation of compositions of SWNTs in and surface active components in density gradient media.

Hersam, Mark C. (Evanston, IL); Stupp, Samuel I. (Chicago, IL); Arnold, Michael S. (Northbrook, IL)

2010-02-16T23:59:59.000Z

198

Inverse diffusion from knowledge of power densities  

E-Print Network [OSTI]

This paper concerns the reconstruction of a diffusion coefficient in an elliptic equation from knowledge of several power densities. The power density is the product of the diffusion coefficient with the square of the modulus of the gradient of the elliptic solution. The derivation of such internal functionals comes from perturbing the medium of interest by acoustic (plane) waves, which results in small changes in the diffusion coefficient. After appropriate asymptotic expansions and (Fourier) transformation, this allow us to construct the power density of the equation point-wise inside the domain. Such a setting finds applications in ultrasound modulated electrical impedance tomography and ultrasound modulated optical tomography. We show that the diffusion coefficient can be uniquely and stably reconstructed from knowledge of a sufficient large number of power densities. Explicit expressions for the reconstruction of the diffusion coefficient are also provided. Such results hold for a large class of boundary...

Bal, Guillaume; Monard, Francois; Triki, Faouzi

2011-01-01T23:59:59.000Z

199

High density effective theory on the lattice  

E-Print Network [OSTI]

Long-range interactions in finite density QCD necessitate a non-perturbative approach in order to reliably map out the key features and spectrum of the QCD phase diagram. However, the complex nature of the fermion determinant in this sector prohibits the use of established Monte Carlo techniques that utilize importance sampling. Whilst significant progress has been made in the low density, high temperature region, this remains a considerable challenge at mid to high density. At large chemical potential, QCD can be approximated using high density effective theory which is free from the sign problem at leading order. We investigate the implementation of this theory on the lattice in conjunction with existing re-weighting techniques.

A. Dougall

2007-10-08T23:59:59.000Z

200

QCD Level Density from Maximum Entropy Method  

E-Print Network [OSTI]

We propose a method to calculate the QCD level density directly from the thermodynamic quantities obtained by lattice QCD simulations with the use of the maximum entropy method (MEM). Understanding QCD thermodynamics from QCD spectral properties has its own importance. Also it has a close connection to phenomenological analyses of the lattice data as well as experimental data on the basis of hadronic resonances. Our feasibility study shows that the MEM can provide a useful tool to study QCD level density.

Shinji Ejiri; Tetsuo Hatsuda

2005-09-24T23:59:59.000Z

Note: This page contains sample records for the topic "density lithium-sulfur cells" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Comment on chiral symmetry restoration at finite density in large-$N_c$ QCD  

E-Print Network [OSTI]

In the article "On chiral symmetry restoration at finite density in large-$N_c$ QCD" by Adhikari, Cohen, Ayyagari and Strother [Phys. Rev. C 83, 065201 (2011)] the description of dense nuclear matter by means of Skyrmions in hyperspherical unit cells is severely criticized. We point out that this criticism is based on invalid assumptions and therefore unwarranted.

Hilmar Forkel

2014-09-06T23:59:59.000Z

202

High energy density, thin-lm, rechargeable lithium batteries for marine eld operations  

E-Print Network [OSTI]

High energy density, thin-®lm, rechargeable lithium batteries for marine ®eld operations Biying February 2001 Abstract All solid state, thin-®lm batteries with the cell con®guration of VOx, no binder) cathode consisted of a dense ®lm of vanadium oxide (200 nm thick), deposited on aluminum foil

Sadoway, Donald Robert

203

Extending the Lifetime of Fuel Cell Based Hybrid Systems* Jianli Zhuo1, Chaitali Chakrabartil, Naehyuck Chang2, Sarma Vrudhula3  

E-Print Network [OSTI]

34.1 Extending the Lifetime of Fuel Cell Based Hybrid Systems* Jianli Zhuo1, Chaitali Chakrabartil@asu.edu ABSTRACT for portable applications. Fuel cells have very high energy densities Fuel cells are clean power densities and lifetimes compared to batteries. However, fuel cells

Kambhampati, Subbarao

204

Nuclear energy density optimization: Shell structure  

E-Print Network [OSTI]

Nuclear density functional theory is the only microscopical theory that can be applied throughout the entire nuclear landscape. Its key ingredient is the energy density functional. In this work, we propose a new parameterization UNEDF2 of the Skyrme energy density functional. The functional optimization is carried out using the POUNDerS optimization algorithm within the framework of the Skyrme Hartree-Fock-Bogoliubov theory. Compared to the previous parameterization UNEDF1, restrictions on the tensor term of the energy density have been lifted, yielding a very general form of the energy density functional up to second order in derivatives of the one-body density matrix. In order to impose constraints on all the parameters of the functional, selected data on single-particle splittings in spherical doubly-magic nuclei have been included into the experimental dataset. The agreement with both bulk and spectroscopic nuclear properties achieved by the resulting UNEDF2 parameterization is comparable with UNEDF1. While there is a small improvement on single-particle spectra and binding energies of closed shell nuclei, the reproduction of fission barriers and fission isomer excitation energies has degraded. As compared to previous UNEDF parameterizations, the parameter confidence interval for UNEDF2 is narrower. In particular, our results overlap well with those obtained in previous systematic studies of the spin-orbit and tensor terms. UNEDF2 can be viewed as an all-around Skyrme EDF that performs reasonably well for both global nuclear properties and shell structure. However, after adding new data aiming to better constrain the nuclear functional, its quality has improved only marginally. These results suggest that the standard Skyrme energy density has reached its limits and significant changes to the form of the functional are needed.

M. Kortelainen; J. McDonnell; W. Nazarewicz; E. Olsen; P. -G. Reinhard; J. Sarich; N. Schunck; S. M. Wild; D. Davesne; J. Erler; A. Pastore

2014-04-28T23:59:59.000Z

205

A Bayesian Probability Calculus for Density Matrices  

E-Print Network [OSTI]

One of the main concepts in quantum physics is a density matrix, which is a symmetric positive definite matrix of trace one. Finite probability distributions are a special case where the density matrix is restricted to be diagonal. Density matrices are mixtures of dyads, where a dyad has the form uu' for any any unit column vector u. These unit vectors are the elementary events of the generalized probability space. Perhaps the simplest case to see that something unusual is going on is the case of uniform density matrix, i.e. 1/n times identity. This matrix assigns probability 1/n to every unit vector, but of course there are infinitely many of them. The new normalization rule thus says that sum of probabilities over any orthonormal basis of directions is one. We develop a probability calculus based on these more general distributions that includes definitions of joints, conditionals and formulas that relate these, i.e. analogs of the theorem of total probability, various Bayes rules for the calculation of posterior density matrices, etc. The resulting calculus parallels the familiar 'classical' probability calculus and always retains the latter as a special case when all matrices are diagonal. Whereas the classical Bayesian methods maintain uncertainty about which model is 'best', the generalization maintains uncertainty about which unit direction has the largest variance. Surprisingly the bounds also generalize: as in the classical setting we bound the negative log likelihood of the data by the negative log likelihood of the MAP estimator.

Manfred K. Warmuth; Dima Kuzmin

2014-08-09T23:59:59.000Z

206

Orbital-optimized density cumulant functional theory  

SciTech Connect (OSTI)

In density cumulant functional theory (DCFT) the electronic energy is evaluated from the one-particle density matrix and two-particle density cumulant, circumventing the computation of the wavefunction. To achieve this, the one-particle density matrix is decomposed exactly into the mean-field (idempotent) and correlation components. While the latter can be entirely derived from the density cumulant, the former must be obtained by choosing a specific set of orbitals. In the original DCFT formulation [W. Kutzelnigg, J. Chem. Phys. 125, 171101 (2006)] the orbitals were determined by diagonalizing the effective Fock operator, which introduces partial orbital relaxation. Here we present a new orbital-optimized formulation of DCFT where the energy is variationally minimized with respect to orbital rotations. This introduces important energy contributions and significantly improves the description of the dynamic correlation. In addition, it greatly simplifies the computation of analytic gradients, for which expressions are also presented. We offer a perturbative analysis of the new orbital stationarity conditions and benchmark their performance for a variety of chemical systems.

Sokolov, Alexander Yu., E-mail: asokolov@uga.edu; Schaefer, Henry F. [Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602 (United States)] [Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602 (United States)

2013-11-28T23:59:59.000Z

207

Tracing spiral density waves in M81  

E-Print Network [OSTI]

We use SPITZER IRAC 3.6 and 4.5micron near infrared data from the Spitzer Infrared Nearby Galaxies Survey (SINGS), optical B, V and I and 2MASS Ks band data to produce mass surface density maps of M81. The IRAC 3.6 and 4.5micron data, whilst dominated by emission from old stellar populations, is corrected for small-scale contamination by young stars and PAH emission. The I band data are used to produce a mass surface density map by a B-V colour-correction, following the method of Bell and de Jong. We fit a bulge and exponential disc to each mass map, and subtract these components to reveal the non-axisymmetric mass surface density. From the residual mass maps we are able to extract the amplitude and phase of the density wave, using azimuthal profiles. The response of the gas is observed via dust emission in the 8micron IRAC band, allowing a comparison between the phase of the stellar density wave and gas shock. The relationship between this angular offset and radius suggests that the spiral structure is reasonably long lived and allows the position of corotation to be determined.

S. Kendall; R. C. Kennicutt; C. Clarke; M. D. Thornley

2008-04-15T23:59:59.000Z

208

ORBITAL-FREE KINETIC-ENERGY DENSITY FUNCTIONAL THEORY  

E-Print Network [OSTI]

Chapter 5 ORBITAL-FREE KINETIC-ENERGY DENSITY FUNCTIONAL THEORY Yan Alexander Wang and Emily A Theory (DFT), there was the Thomas-Fermi (TF) model, which uses the electron density ¢¡ r£ (a function-dependent DFT Density-Functional Theory DI density-independent DM1 first-order reduced density matrix EDF energy

Wang, Yan Alexander

209

OXIDATION OF DRY HYDROCARBONS AT HIGH-POWER DENSITY ANODES  

SciTech Connect (OSTI)

This work builds upon discoveries by the University of Pennsylvania and others pertaining to the oxidation of dry hydrocarbon fuels in high temperature solid oxide fuel cells. The work reported here was restricted primarily to dry methane and confirms that YSZ-based cells, having ceria in the anode as a catalyst and copper in the anode as a current collector, can operate on dry methane for extended periods. Thirty-three lab-scale cells of various designs were fabricated and operated under a variety of conditions. The longest-lived cell gave stable performance on dry methane at 800 C for over 305 hours. Only slight carbon deposition was noted at the completion of the test. A corresponding nickel/YSZ-based anode would have lasted for less than an hour under these test conditions (which included open circuit potential measurements) before carbon fouling essentially destroyed the cell. The best performing cell achieved 112 mW/cm{sub 2} on dry methane at 800 C. Several problems were encountered with carbon fouling and declining open circuit voltages in many of the test cells after switching from operation on hydrogen to dry methane. Although not rigorously confirmed by experimentation, the results suggested that air infiltration through less than perfect perimeter seals or pinholes in the electrolytes, or both gave rise to conditions that caused the carbon fouling and OCV decline. Small amounts of air reacting with methane in a partial oxidation reaction could produce carbon monoxide that, in turn, would deposit the carbon. If this mechanism is confirmed, it implies that near perfect hardware is required for extended operation. Some evidence was also found for the formation of electrical shorts, probably from carbon deposits bridging the electrolyte. Work with odorized methane and with methane containing 100-ppm hydrogen sulfide confirmed that copper is stable at 800 C in dry hydrocarbon fuels in the presence of sulfur. In a number of cases, but not exclusively, the performance life on dry methane with sulfur compounds was much longer than with dry methane alone. The effect of sulfur compounds in these cases appeared to correlate with inhibition of carbon deposition. Mixed results were obtained for the effect of the sulfur compounds on power density. Progress also was made in understanding the mechanisms involved in direct utilization of dry natural gas. Evidence was developed for three possible mechanisms for dry methane utilization in addition to the usually cited mechanism--direct oxidation of methane by oxygen anions. Further work is required at a fundamental level before the knowledge gained here can be translated into higher levels of performance.

K.Krist; O. Spaldon-Stewart; R. Remick

2004-03-01T23:59:59.000Z

210

Fuel Cell Systems Air Management  

E-Print Network [OSTI]

Targets Compressor/Expander for Transportation Fuel Cell System 400--$Cost 10-1510-155Turndown Ratio 15 compressor/expander units for direct hydrogen systems. · Need exists for compressor/ expander motor unit hydrogen 500020001000HoursDurability 45125325$/kWCost 325250140W/LPower density Operating on Tier 2

211

Statistical approach to nuclear level density  

SciTech Connect (OSTI)

We discuss the level density in a finite many-body system with strong interaction between the constituents. Our primary object of applications is the atomic nucleus but the same techniques can be applied to other mesoscopic systems. We calculate and compare nuclear level densities for given quantum numbers obtained by different methods, such as nuclear shell model (the most successful microscopic approach), our main instrument - moments method (statistical approach), and Fermi-gas model; the calculation with the moments method can use any shell-model Hamiltonian excluding the spurious states of the center-of-mass motion. Our goal is to investigate statistical properties of nuclear level density, define its phenomenological parameters, and offer an affordable and reliable way of calculation.

Sen'kov, R. A.; Horoi, M. [Department of Physics, Central Michigan University, Mount Pleasant, MI 48859 (United States); Zelevinsky, V. G. [Department of Physics and Astronomy and National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824-1321 (United States)

2014-10-15T23:59:59.000Z

212

Neutron Matter from Low to High Density  

E-Print Network [OSTI]

Neutron matter is an intriguing nuclear system with multiple connections to other areas of physics. Considerable progress has been made over the last two decades in exploring the properties of pure neutron fluids. Here we begin by reviewing work done to explore the behavior of very low density neutron matter, which forms a strongly paired superfluid and is thus similar to cold Fermi atoms, though at energy scales differing by many orders of magnitude. We then increase the density, discussing work that ties the study of neutron matter with the determination of the properties of neutron-rich nuclei and neutron-star crusts. After this, we review the impact neutron matter at even higher densities has on the mass-radius relation of neutron stars, thereby making contact with astrophysical observations.

Gandolfi, Stefano; Carlson, J

2015-01-01T23:59:59.000Z

213

Fabrication of low density ceramic material  

DOE Patents [OSTI]

A precursor mixture and a method of making a low-density ceramic structural material are disclosed. The precursor mixture includes hollow microballoons, typically made of glass, together with a cementing agent capable of being cured by microwave irradiation. A preferred cementing agent is liquid hydrated potassium silicate, which is mixed with the glass microballoons to form a slurry. Upon irradiation the potassium silicate is dehydrated to form a solid porous matrix in which the microballoons are evenly distributed. Ground glass or other filling agents may be included in the slurry to enhance the properties of the final product. Low-density structural ceramics having densities on the order of 0.1 to 0.3 are obtained.

Meek, T.T.; Blake, R.D.; Sheinberg, H.

1985-01-01T23:59:59.000Z

214

Density matrix of black hole radiation  

E-Print Network [OSTI]

Hawking's model of black hole evaporation is not unitary and leads to a mixed density matrix for the emitted radiation, while the Page model describes a unitary evaporation process in which the density matrix evolves from an almost thermal state to a pure state. We compare a recently proposed model of semiclassical black hole evaporation to the two established models. In particular, we study the density matrix of the outgoing radiation and determine how the magnitude of the off-diagonal corrections differs for the three frameworks. For Hawking's model, we find power-law corrections to the two-point functions that induce exponentially suppressed corrections to the off-diagonal elements of the full density matrix. This verifies that the Hawking result is correct to all orders in perturbation theory and also allows one to express the full density matrix in terms of the single-particle density matrix. We then consider the semiclassical theory for which the corrections, being non-perturbative from an effective field-theory perspective, are much less suppressed and grow monotonically in time. In this case, the R\\'enyi entropy for the outgoing radiation is shown to grow linearly at early times; but this growth slows down and the entropy eventually starts to decrease at the Page time. In addition to comparing models, we emphasize the distinction between the state of the radiation emitted from a black hole, which is highly quantum, and that of the radiation emitted from a typical classical black body at the same temperature.

Lasma Alberte; Ram Brustein; Andrei Khmelnitsky; A. J. M. Medved

2015-02-09T23:59:59.000Z

215

Configuration Interactions Constrained by Energy Density Functionals  

E-Print Network [OSTI]

A new method for constructing a Hamiltonian for configuration interaction calculations with constraints to energies of spherical configurations obtained with energy-density-functional (EDF) methods is presented. This results in a unified model that reproduced the EDF binding-energy in the limit of single-Slater determinants, but can also be used for obtaining energy spectra and correlation energies with renormalized nucleon-nucleon interactions. The three-body and/or density-dependent terms that are necessary for good nuclear saturation properties are contained in the EDF. Applications to binding energies and spectra of nuclei in the region above 208Pb are given.

B. Alex Brown; Angelo Signoracci; Morten Hjorth-Jensen

2010-09-24T23:59:59.000Z

216

Josephson oscillations of charge density waves  

SciTech Connect (OSTI)

The formation of charge density waves in solids was originally proposed as a possible mechanism for superconductivity by Froehlich. Although the experimentally discovered materials with charge density waves (CDW)s are found to have finite resistivity as a result of impurity pinning, they nevertheless reveal many interesting features including motion which is analogous to a resistively shunted Josephson junction of superconductors. The noise spectrum of CDW systems is reviewed with particular emphasis on interactions with normal as well as magnetic impurities. Future prospects for observing an amplitude variation of the noise signals induced by a magnetic field are proposed.

Ruvalds, J.; Tua, P.F.

1985-01-01T23:59:59.000Z

217

Error Analysis in Nuclear Density Functional Theory  

E-Print Network [OSTI]

Nuclear density functional theory (DFT) is the only microscopic, global approach to the structure of atomic nuclei. It is used in numerous applications, from determining the limits of stability to gaining a deep understanding of the formation of elements in the universe or the mechanisms that power stars and reactors. The predictive power of the theory depends on the amount of physics embedded in the energy density functional as well as on efficient ways to determine a small number of free parameters and solve the DFT equations. In this article, we discuss the various sources of uncertainties and errors encountered in DFT and possible methods to quantify these uncertainties in a rigorous manner.

Nicolas Schunck; Jordan D. McDonnell; Jason Sarich; Stefan M. Wild; Dave Higdon

2014-07-11T23:59:59.000Z

218

Time Dependent Density Functional Theory Application to Extended Systems  

E-Print Network [OSTI]

Time Dependent Density Functional Theory Application to Extended Systems Francesco Sottile Facility (ETSF) Donostia, 25 July 2007 Time Dependent Density Functional Theory Francesco Sottile #12 Density Functional Theory Francesco Sottile #12;Linear Periodic systems ALDA The Quest for the Holy

Botti, Silvana

219

Mechanical constraints enhance electrical energy densities of soft dielectrics  

E-Print Network [OSTI]

Mechanical constraints enhance electrical energy densities of soft dielectrics Lin Zhang, Qiming, the dielectric will breakdown electrically. The breakdown limits the electrical energy density of the dielectric electric fields and thus increase their electrical energy densities. The mechanical constraints suppress

Ferrari, Silvia

220

neutron density. The neutron density (nn) of the source was modeled by solving the simul-  

E-Print Network [OSTI]

neutron density. The neutron density (nn) of the source was modeled by solving the simul- taneousT is the thermal neutron velocity, l is the decay constant, Ns is the s-process abun- dance, bsÃ? is the maxwellian-averaged neutron capture cross-section, and t0 is the average neutron exposure (21). The branching decay of 186Re

West, Stuart

Note: This page contains sample records for the topic "density lithium-sulfur cells" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

On the Determination of the Mean Cosmic Matter Density and the Amplitude of Density Fluctuations  

E-Print Network [OSTI]

The cosmological implications from a new estimate of the local X-ray galaxy cluster abundance are summarized. The results are then compared to independent observations. It is suggested that `low' values for the mean cosmic matter density and the amplitude of mass density fluctuations currently do not appear unreasonable observationally.

Thomas H. Reiprich

2002-07-02T23:59:59.000Z

222

In situ PEM fuel cell water measurements  

SciTech Connect (OSTI)

Efficient PEM fuel cell performance requires effective water management. The materials used, their durability, and the operating conditions under which fuel cells run, make efficient water management within a practical fuel cell system a primary challenge in developing commercially viable systems. We present experimental measurements of water content within operating fuel cells. in response to operational conditions, including transients and freezing conditions. To help understand the effect of components and operations, we examine water transport in operating fuel cells, measure the fuel cell water in situ and model the water transport within the fuel cell. High Frequency Resistance (HFR), AC Impedance and Neutron imaging (using NIST's facilities) were used to measure water content in operating fuel cells with various conditions, including current density, relative humidity, inlet flows, flow orientation and variable GDL properties. Ice formation in freezing cells was also monitored both during operation and shut-down conditions.

Borup, Rodney L [Los Alamos National Laboratory; Mukundan, Rangachary [Los Alamos National Laboratory; Davey, John R [Los Alamos National Laboratory; Spendalow, Jacob S [Los Alamos National Laboratory

2008-01-01T23:59:59.000Z

223

Ballard fuel cell development for the new energy environment  

SciTech Connect (OSTI)

Ballard Power Systems is the world leader in the development of Proton Exchange Membrane (PEM) fuel cells. PEM fuel cells use a solid polymer membrane as the electrolyte. These fuel cells are compact and produce powerful electric current relative to their size. PEM fuel cells can deliver higher power density than other types of fuel cells, resulting in reduced cost, weight and volume, and improved performance. The PEM fuel cell is the only fuel cell considered practical for both transportation and stationary applications. Ballard fuel cells are the heart of BGS`s products. The proprietary zero-emission engine converts natural gas, methanol or hydrogen fuel into electricity without combustion.

Dunnison, D.; Smith, D. [Ballard Power Systems, Inc., Burnaby, British Columbia (Canada); Torpey, J. [GPU International, Parsippany, NJ (United States)

1997-09-01T23:59:59.000Z

224

Theoretical Electron Density Distributions for Fe- and Cu-Sulfide...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Electron Density Distributions for Fe- and Cu-Sulfide Earth Materials: A Connection between Bond Length, Bond Theoretical Electron Density Distributions for Fe- and Cu-Sulfide...

225

High power density supercapacitors using locally aligned carbon nanotube electrodes  

E-Print Network [OSTI]

High power density supercapacitors using locally alignedof high power density supercapacitors and other similarcells [6], and for supercapacitors [7–18]. As unique energy

Du, C S; Yeh, J; Pan, Ning

2005-01-01T23:59:59.000Z

226

TEMPO-based Catholyte for High Energy Density Nonaqueous Redox...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

TEMPO-based Catholyte for High Energy Density Nonaqueous Redox Flow Batteries. TEMPO-based Catholyte for High Energy Density Nonaqueous Redox Flow Batteries. Abstract: We will...

227

High Energy Density Laboratory Plasmas Program | National Nuclear...  

National Nuclear Security Administration (NNSA)

Photo Gallery Jobs Apply for Our Jobs Our Jobs Working at NNSA Blog Home High Energy Density Laboratory Plasmas Program High Energy Density Laboratory Plasmas Program...

228

Estimating density of Florida Key deer  

E-Print Network [OSTI]

for this species since 1968; however, a need to evaluate the precision of existing and alternative survey methods (i.e., road counts, mark-recapture, infrared-triggered cameras [ITC]) was desired by USFWS. I evaluated density estimates from unbaited ITCs and road...

Roberts, Clay Walton

2006-08-16T23:59:59.000Z

229

RICE UNIVERSITY Screened Coulomb Hybrid Density Functionals  

E-Print Network [OSTI]

in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy Approved, Thesis Committee-Scuseria-Ernzerhof (HSE) screened Coulomb hybrid density functional is designed to produce exchange energies comparable to traditional hybrids while only using the short range, screened HF exchange. #12;The accuracy of the HSE

Scuseria, Gustavo E.

230

THE QCD PHASE DIAGRAM AT FINITE DENSITY.  

SciTech Connect (OSTI)

We study the density of states method to explore the phase diagram of the chiral transition on the temperature and quark chemical potential plane. Four quark flavours are used in the analysis. Though the method is quite expensive small lattices show an indication for a triple-point connecting three different phases on the phase diagram.

SCHMIDT, C.; FODOR, Z.; KATZ, S.

2005-07-25T23:59:59.000Z

231

Density Functional Theory Approach to Nuclear Fission  

E-Print Network [OSTI]

The Skyrme nuclear energy density functional theory (DFT) is used to model neutron-induced fission in actinides. This paper focuses on the numerical implementation of the theory. In particular, it reports recent advances in DFT code development on leadership class computers, and presents a detailed analysis of the numerical accuracy of DFT solvers for near-scission calculations.

N. Schunck

2013-01-20T23:59:59.000Z

232

Modern applications of covariant density functional theory  

E-Print Network [OSTI]

Modern applications of Covariant Density Functional Theory (CDFT) are discussed. First we show a systematic investigation of fission barriers in actinide nuclei within constraint relativistic mean field theory allowing for triaxial deformations. In the second part we discuss a microscopic theory of quantum phase transitions (QPT) based on the relativistic generator coordinate method.

P. Ring; H. Abusara; A. V. Afanasjev; G. A. Lalazissis; T. Niksic; D. Vretenar

2011-09-19T23:59:59.000Z

233

Density Perturbations for Running Cosmological Constant  

E-Print Network [OSTI]

The dynamics of density and metric perturbations is investigated for the previously developed model where the decay of the vacuum energy into matter (or vice versa) is due to the renormalization group (RG) running of the cosmological constant (CC) term. The evolution of the CC depends on the single parameter \

Julio C. Fabris; Ilya L. Shapiro; Joan Sola

2007-01-26T23:59:59.000Z

234

Drawing Electron Density Maps Tutorial : J. Reibenspies  

E-Print Network [OSTI]

file Choose the difference map #12;Step 2 · If necessary generate full molecule in XSEED or XP shift key to pan) #12;Step 4 · All ball and stick plot to spice it up ZOOMED #12;Step 5 · Save screen the electron density in the macocyclic void in order to understand the disorder #12;Step one · In the INS

Meagher, Mary

235

Density waves in the Calogero model - revisited  

SciTech Connect (OSTI)

The Calogero model bears, in the continuum limit, collective excitations in the form of density waves and solitary modulations of the density of particles. This sector of the spectrum of the model was investigated, mostly within the framework of collective-field theory, by several authors, over the past 15 years or so. In this work we shall concentrate on periodic solutions of the collective BPS-equation (also known as 'finite amplitude density waves'), as well as on periodic solutions of the full static variational equations which vanish periodically (also known as 'large amplitude density waves'). While these solutions are not new, we feel that our analysis and presentation add to the existing literature, as we explain in the text. In addition, we show that these solutions also occur in a certain two-family generalization of the Calogero model, at special points in parameter space. A compendium of useful identities associated with Hilbert transforms, including our own proofs of these identities, appears in Appendix A. In Appendix B we also elucidate in the present paper some fine points having to do with manipulating Hilbert-transforms, which appear ubiquitously in the collective field formalism. Finally, in order to make this paper self-contained, we briefly summarize in Appendix C basic facts about the collective field formulation of the Calogero model.

Bardek, V. [Rudjer Boskovic Institute, Bijenicka c.54, HR-10002 Zagreb (Croatia)], E-mail: bardek@irb.hr; Feinberg, J. [Department of Physics, University of Haifa at Oranim, Tivon 36006 (Israel); Department of Physics, Technion-Israel Inst. of Technology, Haifa 32000 (Israel); KITP, University of California, Santa Barbara, CA 93106-4030 (United States)], E-mail: joshua@physics.technion.ac.il; Meljanac, S. [Rudjer Boskovic Institute, Bijenicka c.54, HR-10002 Zagreb (Croatia)], E-mail: meljanac@irb.hr

2010-03-15T23:59:59.000Z

236

Photovoltaic retinal prosthesis with high pixel density  

E-Print Network [OSTI]

Photovoltaic retinal prosthesis with high pixel density Keith Mathieson1,4 , James Loudin1 to stimulating electrodes via intraocular cables. We present a photovoltaic subretinal prosthesis, in which pixel, demonstrating the possibility of a fully integrated photovoltaic retinal prosthesis with high

Palanker, Daniel

237

Master's Thesis Density Functional Theory for  

E-Print Network [OSTI]

of the information found during my work. v #12;vi #12;Contents Abstract #12;Abstract This thesis presents a number of results for basic quantum mechanical models intended to be used in the development of density functional theory for systems with edges. Following previous work

Armiento, Rickard

238

Methods to enhance blanket power density  

SciTech Connect (OSTI)

The overall objective of this task is to investigate the extent to which the power density in the FED/INTOR breeder blanket test modules can be enhanced by artificial means. Assuming a viable approach can be developed, it will allow advanced reactor blanket modules to be tested on FED/INTOR under representative conditions.

Hsu, P.Y.; Miller, L.G.; Bohn, T.S.; Deis, G.A.; Longhurst, G.R.; Masson, L.S.; Wessol, D.E.; Abdou, M.A.

1982-06-01T23:59:59.000Z

239

Energy enhancement of proton acceleration in combinational radiation pressure and bubble by optimizing plasma density  

SciTech Connect (OSTI)

The combinational laser radiation pressure and plasma bubble fields to accelerate protons are researched through theoretical analysis and numerical simulations. The dephasing length of the accelerated protons bunch in the front of the bubble and the density gradient effect of background plasma on the accelerating phase are analyzed in detail theoretically. The radiation damping effect on the accelerated protons energy is also considered. And it is demonstrated by two-dimensional particle-in-cell simulations that the protons bunch energy can be increased by using the background plasma with negative density gradient. However, radiation damping makes the maximal energy of the accelerated protons a little reduction.

Bake, Muhammad Ali; Xie Baisong [Key Laboratory of Beam Technology and Materials Modification of the Ministry of Education, Beijing Normal University, Beijing 100875 (China); College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Shan Zhang [Department of Mathematics and Physics, Shijiazhuang Tiedao University, Shijiazhuang 050043 (China); Hong Xueren [College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070 (China); Wang Hongyu [Department of Physics, Anshan Normal University, Anshan 114005 (China); Shanghai Bright-Tech Information Technology Co. Ltd, Shanghai 200136 (China)

2012-08-15T23:59:59.000Z

240

Development of alkaline fuel cells.  

SciTech Connect (OSTI)

This project focuses on the development and demonstration of anion exchange membrane (AEM) fuel cells for portable power applications. Novel polymeric anion exchange membranes and ionomers with high chemical stabilities were prepared characterized by researchers at Sandia National Laboratories. Durable, non-precious metal catalysts were prepared by Dr. Plamen Atanassov's research group at the University of New Mexico by utilizing an aerosol-based process to prepare templated nano-structures. Dr. Andy Herring's group at the Colorado School of Mines combined all of these materials to fabricate and test membrane electrode assemblies for single cell testing in a methanol-fueled alkaline system. The highest power density achieved in this study was 54 mW/cm2 which was 90% of the project target and the highest reported power density for a direct methanol alkaline fuel cell.

Hibbs, Michael R.; Jenkins, Janelle E.; Alam, Todd Michael; Janarthanan, Rajeswari [Colorado School of Mines, Golden, CO; Horan, James L. [Colorado School of Mines, Golden, CO; Caire, Benjamin R. [Colorado School of Mines, Golden, CO; Ziegler, Zachary C. [Colorado School of Mines, Golden, CO; Herring, Andrew M. [Colorado School of Mines, Golden, CO; Yang, Yuan [Colorado School of Mines, Golden, CO; Zuo, Xiaobing [Argonne National Laboratory, Argonne, IL; Robson, Michael H. [University of New Mexico, Albuquerque, NM; Artyushkova, Kateryna [University of New Mexico, Albuquerque, NM; Patterson, Wendy [University of New Mexico, Albuquerque, NM; Atanassov, Plamen Borissov [University of New Mexico, Albuquerque, NM

2013-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "density lithium-sulfur cells" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

?Linear Gas Jet with Tailored Density Profile"  

SciTech Connect (OSTI)

Supersonic, highly collimated gas jets and gas-filled capillary discharge waveguides are two primary targets of choice for Laser Plasma Accelerators (LPA) . Present gas jets have lengths of only 2-4 mm at densities of 1-4E19 cm-3, sufficient for self trapping and electron acceleration to energies up to ~150 MeV. Capillary structures 3 cm long have been used to accelerate beams up to 1 GeV. Capillary discharges used in LPAs serve to guide the pump laser and optimize the energy gain. A wall-stabilized capillary discharge provides a transverse profile across the channel that helps guide the laser and combat diffraction. Gas injection via a fast nozzle at one end provides some longitudinal density control, to improve the coupling. Gas jets with uniform or controlled density profiles may be used to control electron bunch injection and are being integrated into capillary experiments to add tuning of density. The gas jet for electron injection has not yet been optimized. Our Ph-I results have provided the LPA community with an alternative path to realizing a 2-3GeV electron bunch using just a gas jet. For example, our slit/blade combination gives a 15-20mm long acceleration path with tunable density profile, serving as an alternative to a 20-mm long capillary discharge with gas injection at one end. In Ph-II, we will extend these results to longer nozzles, to see whether we can synthesize 30 or 40-mm long plasma channels for LPAs.

KRISHNAN, Mahadevan

2012-12-10T23:59:59.000Z

242

Optimizing membrane electrode assembly of direct methanol fuel cells for portable power.  

E-Print Network [OSTI]

??Direct methanol fuel cells (DMFCs) for portable power applications require high power density, high-energy conversion efficiency and compactness. These requirements translate to fundamental properties of… (more)

Liu, Fuqiang

2006-01-01T23:59:59.000Z

243

The problem of the universal density functional and the density matrix functional theory  

SciTech Connect (OSTI)

The analysis in this paper shows that the Hohenberg-Kohn theorem is the constellation of two statements: (i) the mathematically rigorous Hohenberg-Kohn lemma, which demonstrates that the same ground-state density cannot correspond to two different potentials of an external field, and (ii) the hypothesis of the existence of the universal density functional. Based on the obtained explicit expression for the nonrel-ativistic particle energy in a local external field, we prove that the energy of the system of more than two non-interacting electrons cannot be a functional of the inhomogeneous density. This result is generalized to the system of interacting electrons. It means that the Hohenberg-Kohn lemma cannot provide justification of the universal density functional for fermions. At the same time, statements of the density functional theory remain valid when considering any number of noninteracting ground-state bosons due to the Bose condensation effect. In the framework of the density matrix functional theory, the hypothesis of the existence of the universal density matrix functional corresponds to the cases of noninteracting particles and to interaction in the Hartree-Fock approximation.

Bobrov, V. B., E-mail: vic5907@mail.ru; Trigger, S. A., E-mail: satron@mail.ru [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

2013-04-15T23:59:59.000Z

244

Direct Methanol Fuel Cell Experimental and Model Validation Study  

E-Print Network [OSTI]

Direct Methanol Fuel Cell Experimental and Model Validation Study M. Mench, J. Scott, S. Thynell boundary Fuel cell performance Current density distribution measurements Conclusions #12;3 Method, flow rate, species inlet and fuel cell temperature, and humidity. Transparent polycarbonate windows

Wang, Chao-Yang

245

Alcohol Fuel Cells at Optimal Temperatures Tetsuya Uda,a  

E-Print Network [OSTI]

Alcohol Fuel Cells at Optimal Temperatures Tetsuya Uda,a Dane A. Boysen,b Calum R. I. Chisholm of operation, 250°C, is matched both to the optimal value for fuel cell power output and for reforming. Peak, California 91125, USA High-power-density alcohol fuel cells can relieve many of the daunting challenges

246

Electrode for a lithium cell  

DOE Patents [OSTI]

This invention relates to a positive electrode for an electrochemical cell or battery, and to an electrochemical cell or battery; the invention relates more specifically to a positive electrode for a non-aqueous lithium cell or battery when the electrode is used therein. The positive electrode includes a composite metal oxide containing AgV.sub.3O.sub.8 as one component and one or more other components consisting of LiV.sub.3O.sub.8, Ag.sub.2V.sub.4O.sub.11, MnO.sub.2, CF.sub.x, AgF or Ag.sub.2O to increase the energy density of the cell, optionally in the presence of silver powder and/or silver foil to assist in current collection at the electrode and to improve the power capability of the cell or battery.

Thackeray, Michael M. (Naperville, IL); Vaughey, John T. (Elmhurst, IL); Dees, Dennis W. (Downers Grove, IL)

2008-10-14T23:59:59.000Z

247

Method to improve reliability of a fuel cell system using low performance cell detection at low power operation  

DOE Patents [OSTI]

A system and method for detecting a low performing cell in a fuel cell stack using measured cell voltages. The method includes determining that the fuel cell stack is running, the stack coolant temperature is above a certain temperature and the stack current density is within a relatively low power range. The method further includes calculating the average cell voltage, and determining whether the difference between the average cell voltage and the minimum cell voltage is greater than a predetermined threshold. If the difference between the average cell voltage and the minimum cell voltage is greater than the predetermined threshold and the minimum cell voltage is less than another predetermined threshold, then the method increments a low performing cell timer. A ratio of the low performing cell timer and a system run timer is calculated to identify a low performing cell.

Choi, Tayoung; Ganapathy, Sriram; Jung, Jaehak; Savage, David R.; Lakshmanan, Balasubramanian; Vecasey, Pamela M.

2013-04-16T23:59:59.000Z

248

Oblique interactions of dust density waves  

SciTech Connect (OSTI)

Self-excited dust density waves (DDWs) are studied in a striped electrode device. In addition to the usual perpendicularly (with respect to the electrode) propagating DDWs, which have been frequently observed in dusty plasma experiments on the ground, a low-frequency oblique mode is also observed. This low-frequency oblique DDW has a frequency much lower than the dust plasma frequency and its spontaneous excitation is observed even with a very low dust density. It is found that the low-frequency oblique mode can exist either separately or together with the usual perpendicular mode. In the latter case, a new mode arises as a result of the interactions between the perpendicular and the oblique modes. The experiments show that these three modes satisfy the wave coupling conditions in both the frequencies and the wave-vectors.

Wang, Zhelchui [Los Alamos National Laboratory; Li, Yang - Fang [MAX-PLANCK INSTITUTE; Hou, Lujing [MAX-PLANCK INSTITUTE; Jiang, Ke [MAX-PLANCK INSTITUTE; Wu, De - Jin [CHINA; Thomas, Hubertus M [MAX-PLANCK INSTITUTE; Morfill, Gregor E [MAX-PLANCK INSTITUTE

2010-01-01T23:59:59.000Z

249

Global coherence of dust density waves  

SciTech Connect (OSTI)

The coherence of self-excited three-dimensional dust density waves has been experimentally investigated by comparing global and local wave properties. For that purpose, three-dimensional dust clouds have been confined in a radio frequency plasma with thermophoretic levitation. Global wave properties have been measured from the line-of-sight integrated dust density obtained from homogenous light extinction measurements. Local wave properties have been obtained from thin, two-dimensional illuminated laser slices of the cloud. By correlating the simultaneous global and local wave properties, the spatial coherence of the waves has been determined. We find that linear waves with small amplitudes tend to be fragmented, featuring an incoherent wave field. Strongly non-linear waves with large amplitudes, however, feature a strong spatial coherence throughout the dust cloud, indicating a high level of synchronization.

Killer, Carsten; Melzer, André [Institut für Physik, Ernst-Moritz-Arndt-Universität Greifswald, 17489 Greifswald (Germany)

2014-06-15T23:59:59.000Z

250

Development of Silica Aerogel with Any Density  

E-Print Network [OSTI]

Abstract–New production methods of silica aerogel with high and low refractive indices have been developed. A very slow shrinkage of alcogel at room temperature has made possible producing aerogel with high refractive indices of up to 1.265 without cracks. Even higher refractive indices than 1.08, the transmission length of the aerogel obtained from this technique has been measured to be about 10 to 20 mm at 400 nm wave length. A mold made of alcogel which endures shrinkage in the supercritical drying process has provided aerogel with the extremely low density of 0.009g/cm 3, which corresponds to the refractive index of 1.002. We have succeeded producing aerogel with a wide range of densities. I.

M. Tabata; I. Adachi; T. Fukushima; H. Kawai; H. Kishimoto; A. Kuratani; H. Nakayama; S. Nishida; T. Noguchi; K. Okudaira; Y. Tajima; H. Yano; H. Yokogawa; H. Yoshida

251

DENSITY FUNCTIONAL THEORY OF NORMAL AND SUPERCONDUCTING ELECTRON LIQUIDS: EXPLICIT  

E-Print Network [OSTI]

DENSITY FUNCTIONAL THEORY OF NORMAL AND SUPERCONDUCTING ELECTRON LIQUIDS: EXPLICIT FUNCTIONALS VIAÃ?th University Nathan, Queensland 4111, Australia Abstract The basic idea of density functional theory is to map potential which is a functional of the density. The central task of density functional theory is to #12;nd

Gross, E.K.U.

252

Energy-momentum Density of Gravitational Waves  

E-Print Network [OSTI]

In this paper, we elaborate the problem of energy-momentum in general relativity by energy-momentum prescriptions theory. Our aim is to calculate energy and momentum densities for the general form of gravitational waves. In this connection, we have extended the previous works by using the prescriptions of Bergmann and Tolman. It is shown that they are finite and reasonable. In addition, using Tolman prescription, exactly, leads to same results that have been obtained by Einstein and Papapetrou prescriptions.

Amir M. Abbassi; Saeed Mirshekari

2014-11-29T23:59:59.000Z

253

Mapping densities in a noisy state space  

E-Print Network [OSTI]

Weak noise smooths out fractals in a chaotic state space and introduces a maximum attainable resolution to its structure. The balance of noise and deterministic stretching/contraction in each neighborhood introduces local invariants of the dynamics that can be used to partition the state space. We study the local discrete-time evolution of a density in a two-dimensional hyperbolic state space, and use the asymptotic eigenfunctions for the noisy dynamics to formulate a new state space partition algorithm.

Domenico Lippolis

2013-03-05T23:59:59.000Z

254

High Energy Density Utracapacitors: Low-Cost, High Energy and Power Density, Nanotube-Enhanced Ultracapacitors  

SciTech Connect (OSTI)

Broad Funding Opportunity Announcement Project: FastCAP is improving the performance of an ultracapacitor—a battery-like electronic device that can complement, and possibly even replace, an HEV or EV battery pack. Ultracapacitors have many advantages over conventional batteries, including long lifespans (over 1 million cycles, as compared to 10,000 for conventional batteries) and better durability. Ultracapacitors also charge more quickly than conventional batteries, and they release energy more quickly. However, ultracapacitors have fallen short of batteries in one key metric: energy density—high energy density means more energy storage. FastCAP is redesigning the ultracapacitor’s internal structure to increase its energy density. Ultracapacitors traditionally use electrodes made of irregularly shaped, porous carbon. FastCAP’s ultracapacitors are made of tiny, aligned carbon nanotubes. The nanotubes provide a regular path for ions moving in and out of the ultracapacitor’s electrode, increasing the overall efficiency and energy density of the device.

None

2010-04-01T23:59:59.000Z

255

Effect of tab design on large-format Li-ion cell performance , Gang Luo b  

E-Print Network [OSTI]

to much lower energy density than their coin cell benchmarks. In this work, a 3D computational methodology the cell is operated at high power, which is ubiqui- tous in hybrid and pure electric vehicle (HEV

256

E-Print Network 3.0 - atmospheric pressure cell Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Fuel Cell Air Supply System1 Sylvain Gelfi2 , Anna G... of the fuel cell system. High stack power density is the main selling point of high-pressure sys- tems... RPM) and very...

257

LowerLower--Cost Fuel CellsCost Fuel Cells Allen J. Bard, Arumugam Manthiram,Allen J. Bard, Arumugam Manthiram,  

E-Print Network [OSTI]

density 4 Hydrogen polymer electrolyteHydrogen polymer electrolyte membrane fuel cell (PEMFC)membrane fuel1 LowerLower--Cost Fuel CellsCost Fuel Cells Allen J. Bard, Arumugam Manthiram,Allen J. BardMaterials Science and Engineering Program 2 CONVENTIONAL POWER PLANT DIRECT FUEL CELL POWER PLANT Heat

Lightsey, Glenn

258

Progress in fuel cells for transportation applications  

SciTech Connect (OSTI)

The current and projected states of development of fuel cells are described in terms of availability, performance, and cost. The applicability of various fuel cell types to the transportation application is discussed, and projections of power densities, weights, and volumes of fuel cell systems are made into the early 1990s. Research currently being done to advance fuel cells for vehicular application is described. A summary of near-term design parameters for a fuel cell transit line is given, including bus performance requirements, fuel cell power plant configuration, and battery peaking requirements. The objective of this paper is to determine a fuel cell technology suitable for near-term use as a vehicular power plant. The emphasis of the study is on indirect methanol fuel cell systems.

Murray, H.S.

1986-01-01T23:59:59.000Z

259

Liquids that form due to dynamics of the molecules that depend on the local density  

E-Print Network [OSTI]

RNA molecules in living cells form what look like liquid droplets formed by liquid/liquid phase separation. But unlike the molecules in conventional phase separating mixtures, RNA molecules are transported by molecular motors that consume energy and so are out of equilibrium. Motivated by this we consider what sort of simple rules for the dynamics of model mRNA molecules lead to liquid/liquid phase separation. We find that dynamics that slow as the local density of molecules increases, drive the formation of liquids. We also look at the analogous separation of the two blocks of a block copolymer, in which the monomers of one block have dynamics that depend on the local density of monomers of that block. We find that this block condenses and separates from the monomers of the other block. This is a simple model of the out-of-equilibrium domain formation found in the chromatin in the nucleus of cells.

Richard P. Sear

2015-03-26T23:59:59.000Z

260

Lewis Acid-Base Interactions between Polysulfides and Metal Organic...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Lewis Acid-Base Interactions between Polysulfides and Metal Organic Framework in Lithium Sulfur Batteries. Lewis Acid-Base Interactions between Polysulfides and Metal Organic...

Note: This page contains sample records for the topic "density lithium-sulfur cells" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Carbon/Sulfur Nanocomposites and Additives for High-Energy Lithium...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

More Documents & Publications Additives and Cathode Materials for High-Energy Lithium Sulfur Batteries CarbonSulfur Nanocomposites and Additives for High-Energy Lithium...

262

Manufacturing of Protected Lithium Electrodes for Advanced Lithium...  

Broader source: Energy.gov (indexed) [DOE]

Lithium Electrodes for Advanced Lithium-Air, Lithium-Water, and Lithium-Sulfur Batteries, April 2013 Manufacturing of Protected Lithium Electrodes for Advanced Lithium-Air,...

263

Fabrication of thin-wall hollow nickel spheres and low density syntactic foams  

SciTech Connect (OSTI)

A process has been developed to fabricate thin-wall hollow spheres from conventional oxide powders at room temperature. The polymer- bonded powder shells are fired in air to sinter the walls, leaving the shells either impervious or porous. Alternatively, the oxide shells can be preferentially reduced to produce thin-wall hollow metal spheres which can be bonded together to produce an ultra light weight closed-cell foam. Processing and properties of this class of low density structures will be discussed.

Clancy, R.B.; Sanders, T.H. Jr.; Cochran, J.K.

1991-12-31T23:59:59.000Z

264

Experimental and numerical investigations of electron density in low-pressure dual-frequency capacitively coupled oxygen discharges  

SciTech Connect (OSTI)

The electron density is measured in low-pressure dual-frequency (2/60 MHz) capacitively coupled oxygen discharges by utilizing a floating hairpin probe. The dependence of electron density at the discharge center on the high frequency (HF) power, low frequency (LF) power, and gas pressure are investigated in detail. A (1D) particle-in-cell/Monte Carlo method is developed to calculate the time-averaged electron density at the discharge center and the simulation results are compared with the experimental ones, and general agreements are achieved. With increasing HF power, the electron density linearly increases. The electron density exhibits different changes with the LF power at different HF powers. At low HF powers (e.g., 30 W in our experiment), the electron density increases with increasing LF power while the electron density decreases with increasing LF power at relatively high HF powers (e.g., 120 W in our experiment). With increasing gas pressure the electron density first increases rapidly to reach a maximum value and then decreases slowly due to the combined effect of the production process by the ionization and the loss processes including the surface and volume losses.

Liu, Jia; Wen, De-Qi; Liu, Yong-Xin; Gao, Fei; Lu, Wen-Qi; Wang, You-Nian [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)] [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)

2013-11-15T23:59:59.000Z

265

Method of high-density foil fabrication  

DOE Patents [OSTI]

A method for preparing flat foils having a high density includes the steps of mixing a powdered material with a binder to form a green sheet. The green sheet is exposed to a high intensity radiative source adapted to emit radiation of wavelengths corresponding to an absorption spectrum of the powdered material. The surface of the green sheet is heated while a lower sub-surface temperature is maintained. An apparatus for preparing a foil from a green sheet using a radiation source is also disclosed.

Blue, Craig A.; Sikka, Vinod K.; Ohriner, Evan K.

2003-12-16T23:59:59.000Z

266

Nuclear Energy Density Optimization: UNEDF2  

E-Print Network [OSTI]

The parameters of the UNEDF2 nuclear energy density functional (EDF) model were obtained in an optimization to experimental data consisting of nuclear binding energies, proton radii, odd-even mass staggering data, fission-isomer excitation energies, and single particle energies. In addition to parameter optimization, sensitivity analysis was done to obtain parameter uncertainties and correlations. The resulting UNEDF2 is an all-around EDF. However, the sensitivity analysis also demonstrated that the limits of current Skyrme-like EDFs have been reached and that novel approaches are called for.

M. Kortelainen; J. McDonnell; W. Nazarewicz; E. Olsen; P. -G. Reinhard; J. Sarich; N. Schunck; S. M. Wild; D. Davesne; J. Erler; A. Pastore

2014-10-30T23:59:59.000Z

267

Low density inorganic foams fabricated using microwaves  

SciTech Connect (OSTI)

The objective of our work was to determine if high temperature foams could be made using microwave heating; and if so, to investigate some of their properties. Several foams were made and their compressive strengths, tensile strengths and densities were determined. Foams were made of glass, metal-glass, glass-fiber, metal-glass-fiber, and fly ash. The microwave source used was a Litton model 1521 microwave oven which operated at 2.45 GHz and had an output of 700 watts.

Meek, T.T.; Blake, R.D.; Gregory, T.G.

1985-01-01T23:59:59.000Z

268

Symmetry energy in nuclear density functional theory  

E-Print Network [OSTI]

The nuclear symmetry energy represents a response to the neutron-proton asymmetry. In this survey we discuss various aspects of symmetry energy in the framework of nuclear density functional theory, considering both non-relativistic and relativistic self-consistent mean-field realizations side-by-side. Key observables pertaining to bulk nucleonic matter and finite nuclei are reviewed. Constraints on the symmetry energy and correlations between observables and symmetry-energy parameters, using statistical covariance analysis, are investigated. Perspectives for future work are outlined in the context of ongoing experimental efforts.

W. Nazarewicz; P. -G. Reinhard; W. Satula; D. Vretenar

2013-07-22T23:59:59.000Z

269

ARM - Lesson Plans: Air Density and Temperature  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc Documentation RUC : XDCResearch Related InformationAcid Rain Outreach Home Room NewsDensity and

270

OPTIMAL DESIGN OF HYBRID FUEL CELL VEHICLES  

E-Print Network [OSTI]

Fuel cells are being considered increasingly as a viable alternative energy source for automobiles because of their clean and efficient power generation. Numerous technological concepts have been developed and compared in terms of safety, robust operation, fuel economy, and vehicle performance. However, several issues still exist and must be addressed to improve the viability of this emerging technology. Despite the relatively large number of models and prototypes, a model-based vehicle design capability with sufficient fidelity and efficiency is not yet available in the literature. In this article we present an analysis and design optimization model for fuel cell vehicles that can be applied to both hybrid and non-hybrid vehicles by integrating a fuel cell vehicle simulator with a physics-based fuel cell model. The integration is achieved via quasi-steady fuel cell performance maps, and provides the ability to modify the characteristics of fuel cell systems with sufficient accuracy (less than 5 % error) and efficiency (98 % computational time reduction on average). Thus, a vehicle can be optimized subject to constraints that include various performance metrics and design specifications so that the overall efficiency of the hybrid fuel cell vehicle can be improved by 14 % without violating any constraints. The obtained optimal fuel cell system is also compared to other, not vehicle-related, fuel cell systems optimized for maximum power density or maximum efficiency. A tradeoff between power density and efficiency can be observed depending on the size of compressors. Typically, a larger compressor results in higher fuel cell power density at the cost of fuel cell efficiency because it operates in a wider current region. When optimizing the fuel cell

Jeongwoo Han; Michael Kokkolaras; Panos Papalambros

271

The density of states approach for the simulation of finite density quantum field theories  

E-Print Network [OSTI]

Finite density quantum field theories have evaded first principle Monte-Carlo simulations due to the notorious sign-problem. The partition function of such theories appears as the Fourier transform of the generalised density-of-states, which is the probability distribution of the imaginary part of the action. With the advent of Wang-Landau type simulation techniques and recent advances, the density-of-states can be calculated over many hundreds of orders of magnitude. Current research addresses the question whether the achieved precision is high enough to reliably extract the finite density partition function, which is exponentially suppressed with the volume. In my talk, I review the state-of-play for the high precision calculations of the density-of-states as well as the recent progress for obtaining reliable results from highly oscillating integrals. I will review recent progress for the $Z_3$ quantum field theory for which results can be obtained from the simulation of the dual theory, which appears to free of a sign problem.

K. Langfeld; B. Lucini; A. Rago; R. Pellegrini; L. Bongiovanni

2015-03-02T23:59:59.000Z

272

2006 Alkaline Membrane Fuel Cell Workshop Final Report  

Broader source: Energy.gov (indexed) [DOE]

single cell with a current density on the order of 150 mAcm2 is desired, appropriate heat removal designs need to be explored, as well as the use of efficient pumps and blowers....

273

Lithium Source For High Performance Li-ion Cells  

Broader source: Energy.gov (indexed) [DOE]

New cathode and anode electrodes are required to improve the energy density of Li-ion cells for transportation technologies. The cost of Li-ion systems for transportation...

274

Covariant density functional theory for antimagnetic rotation  

E-Print Network [OSTI]

Following the previous letter on the first microscopic description of the antimagnetic rotation (AMR) in 105Cd, a systematic investigation and detailed analysis for the AMR band in the frame-work of tilted axis cranking (TAC) model based on covariant density functional theory are carried out. After performing the microscopic and self-consistentTAC calculations with an given density functional, the configuration for the observed AMR band in 105Cd is obtained from the single-particle Routhians. With the configuration thus obtained, the tilt angle for a given rotational frequency is determined self-consistently by minimizing the total Routhian with respect to the tilt angle. In such a way, the energy spectrum, total angular momenta, kinetic and dynamic moments of inertia, and the B(E2) values for the AMR band in 105Cd are calculated. Good agreement with the data is found. By investigating microscopically the contributions from neutrons and protons to the total angular momentum, the "two-shears-like" mechanism in the AMR band is clearly illus-trated. Finally, the currents leading to time-odd mean fields in the Dirac equation are presented and discussed in detail. It is found that they are essentially determined by the valence particles and/or holes. Their spatial distribution and size depend onthe specific single-particle orbitals and the rotational frequency.

P. W. Zhao; J. Peng; H. Z. Liang; P. Ring; J. Meng

2012-05-04T23:59:59.000Z

275

Longitudinal density monitor for the LHC  

DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

The longitudinal density monitor (LDM) is primarily intended for the measurement of the particle population in nominally empty rf buckets. These so-called satellite or ghost bunches can cause problems for machine protection as well as influencing the luminosity calibration of the LHC. The high dynamic range of the system allows measurement of ghost bunches with as little as 0.01% of the main bunch population at the same time as characterization of the main bunches. The LDM is a single-photon counting system using visible synchrotron light. The photon detector is a silicon avalanche photodiode operated in Geiger mode, which allows the longitudinal distribution of the LHC beams to be measured with a resolution of 90 ps. Results from the LDM are presented, including a proposed method for constructing a 3-dimensional beam density map by scanning the LDM sensor in the transverse plane. In addition, we present a scheme to improve the sensitivity of the system by using an optical switching technique.

Jeff, A.; Andersen, M.; Boccardi, A.; Bozyigit, S.; Bravin, E.; Lefevre, T.; Rabiller, A.; Roncarolo, F.; Welsch, C. P.; Fisher, A. S.

2012-03-01T23:59:59.000Z

276

Solar Cell Light Trapping beyond the Ray Optic Limit Dennis M. Callahan,* Jeremy N. Munday,  

E-Print Network [OSTI]

Solar Cell Light Trapping beyond the Ray Optic Limit Dennis M. Callahan,* Jeremy N. Munday: Photovoltaic cell, solar cell, local density of optical states (LDOS), light trapping, plasmonic, nanophotonic light trapping, as the solar cell absorber layer thickness is reduced, absorption is also reduced

Atwater, Harry

277

A Quantum Hydrodynamic Model for a Photovoltaic Cell  

SciTech Connect (OSTI)

We present a theoretical model for the behaviour of the propagation of electrons in a photovoltaic cell with some Bohm quantum potential corrections. The system describes the dynamic of the electron density and the current density functions. Also, a numerical solution for the 1-dimensional case based on the backward finite differences method is given.

Zaharie, Ioan [Politehnica University of Timisoara, Dept. of Physics, V. Parvan 2, 300223 Timisoara (Romania); Negrea, Romeo; Hedrea, Ciprian [Politehnica University of Timisoara, Dept. of Mathematics, Victoriei 2, 300006 Timisoara (Romania)

2009-05-22T23:59:59.000Z

278

Performance Optimization of Battery-Super Capacitor Hybrid System Electrochemical capacitors (ultracapacitors) offer high power density when compared to battery  

E-Print Network [OSTI]

Performance Optimization of Battery-Super Capacitor Hybrid System Electrochemical capacitors of super capacitors with batteries and fuel cells under specific loads. Despite the fact that Lithium density compared to conventional capacitors. In the late nineties they have gained considerable attention

Popov, Branko N.

279

High density Ru nanocrystal deposition for nonvolatile memory applications  

E-Print Network [OSTI]

High density Ru nanocrystal deposition for nonvolatile memory applications Damon B. Farmer School density optimizes the charge storing capability of the floating layer, while a high degree of size

280

Wood-Fiber/High-Density-Polyethylene Composites: Compounding Process  

E-Print Network [OSTI]

Wood-Fiber/High-Density-Polyethylene Composites: Compounding Process J. Z. Lu,1 Q. Wu,1 I. I parameters for the wood-fiber/high-density-polyethylene blends at 60 rpm were a temperature of 180°C

Note: This page contains sample records for the topic "density lithium-sulfur cells" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Experimental bond critical point and local energy density properties...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Mn-O, Fe-O and Co-O bonded interactions for Abstract: Bond critical point, bcp, and local energy density properties for the electron density, ED, distributions, calculated with...

282

Innovative fuel designs for high power density pressurized water reactor  

E-Print Network [OSTI]

One of the ways to lower the cost of nuclear energy is to increase the power density of the reactor core. Features of fuel design that enhance the potential for high power density are derived based on characteristics of ...

Feng, Dandong, Ph. D. Massachusetts Institute of Technology

2006-01-01T23:59:59.000Z

283

Design of annular fuel for high power density BWRs  

E-Print Network [OSTI]

Enabling high power density in the core of Boiling Water Reactors (BWRs) is economically profitable for existing or new reactors. In this work, we examine the potential for increasing the power density in BWR plants by ...

Morra, Paolo

2005-01-01T23:59:59.000Z

284

Constrained Density-Functional Theory--Configuration Interaction  

E-Print Network [OSTI]

In this thesis, I implemented a method for performing electronic structure calculations, "Constrained Density Functional Theory-- Configuration Interaction" (CDFT-CI), which builds upon the computational strengths of Density ...

Kaduk, Benjamin James

2012-01-01T23:59:59.000Z

285

Insights Gained from Testing Alternate Cell Designs  

SciTech Connect (OSTI)

The Idaho National Laboratory (INL) has been researching the application of solid-oxide electrolysis cell for large-scale hydrogen production from steam over a temperature range of 800 to 900ºC. The INL has been testing various solid oxide cell designs to characterize their electrolytic performance operating in the electrolysis mode for hydrogen production. Some results presented in this report were obtained from cells, initially developed by the Forschungszentrum Jülich and now manufactured by the French ceramics firm St. Gobain. These cells have an active area of 16 cm2 per cell. They were initially developed as fuel cells, but are being tested as electrolytic cells in the INL test stands. The electrolysis cells are electrode-supported, with ~10 µm thick yttria-stabilized zirconia (YSZ) electrolytes, ~1400 µm thick nickel-YSZ steam-hydrogen electrodes, and manganite (LSM) air-oxygen electrodes. The experiments were performed over a range of steam inlet mole fractions (0.1 to 0.6), gas flow rates, and current densities (0 to 0.6 A/cm2). Steam consumption rates associated with electrolysis were measured directly using inlet and outlet dewpoint instrumentation. On a molar basis, the steam consumption rate is equal to the hydrogen production rate. Cell performance was evaluated by performing DC potential sweeps at 800, 850, and 900°C. The voltage-current characteristics are presented, along with values of area-specific resistance as a function of current density. Long-term cell performance is also assessed to evaluate cell degradation. Details of the custom single-cell test apparatus developed for these experiments are also presented. NASA, in conjunction with the University of Toledo, has developed another fuel cell concept with the goals of reduced weight and high power density. The NASA cell is structurally symmetrical, with both electrodes supporting the thin electrolyte and containing micro-channels for gas diffusion. This configuration is called a bi-electrode supported cell or BSC. The electrodes are made by freeze-casting, a modified tape casting technique which creates the many micro-channels in the YSZ electrode green tape. This report presents results of the INL’s testing of this new solid oxide cell design as an electrolyzer. Gas composition, operating voltage, and other parameters were varied during testing. Results to date show the NASA cell to be a promising design for both high power-to-weight fuel cell and electrolyzer applications.

J. E. O'Brien; C. M. Stoots; J. S. Herring; G. K. Housley; M. S. Sohal; D. G. Milobar; Thomas Cable

2009-09-01T23:59:59.000Z

286

High energy density redox flow device  

DOE Patents [OSTI]

Redox flow devices are described in which at least one of the positive electrode or negative electrode-active materials is a semi-solid or is a condensed ion-storing electroactive material, and in which at least one of the electrode-active materials is transported to and from an assembly at which the electrochemical reaction occurs, producing electrical energy. The electronic conductivity of the semi-solid is increased by the addition of conductive particles to suspensions and/or via the surface modification of the solid in semi-solids (e.g., by coating the solid with a more electron conductive coating material to increase the power of the device). High energy density and high power redox flow devices are disclosed. The redox flow devices described herein can also include one or more inventive design features. In addition, inventive chemistries for use in redox flow devices are also described.

Chiang, Yet-Ming; Carter, W. Craig; Ho, Bryan Y; Duduta, Mihai; Limthongkul, Pimpa

2014-05-13T23:59:59.000Z

287

Ternary liquid mixture viscosities and densities  

SciTech Connect (OSTI)

Liquid mixture viscosities and densities have been measured at 298.15 K and ambient pressure for 20 ternary systems. Twelve ternary compositions, encompassing the entire composition range, have been chosen for each system in an effort to test a newly proposed predictive equation based on local compositions. Viscosities calculated by using the local composition model agreed with the experimental data within an average absolute deviation of 6.4%. No adjustable parameters were used and only binary interactions in the form of NRTL constants were input. The results of these studies indicate that the local composition model predictions are generally as good for multicomponent systems as they are for the corresponding binaries. 24 references, 3 tables.

Wei, I.C.; Rowley, R.L.

1984-01-01T23:59:59.000Z

288

Energy density fluctuations in early universe  

SciTech Connect (OSTI)

The primordial nucleosinthesys of the element can be influenced by the transitions of phase that take place after the Big Bang, such as the QCD transition. In order to study the effect of this phase transition, in this work we compute the time evolution of thermodynamical quantities of the early universe, focusing on temperature and energy density fluctuations, by solving the relevant equations of motion using as input the lattice QCD equation of state to describe the strongly interacting matter in the early universe plasma. We also study the effect of a primordial strong magnetic field by means of a phenomenological equation of state. Our results show that small inhomogeneities of strongly interacting matter in the early Universe are moderately damped during the crossover.

Guardo, G. L.; Ruggieri, M. [Department of Physics and Astronomy, University of Catania, Catania (Italy); Greco, V. [Department of Physics and Astronomy, University of Catania, Catania, Italy and INFN - Laboratori Nazionali del Sud, Catania (Italy)

2014-05-09T23:59:59.000Z

289

Competition between superconductivity and spin density wave  

E-Print Network [OSTI]

The Hubbard model has been investigated widely by many authors, while this work may be new in two aspects. One, we focus on the possible effects of the positions of the gaps associated with the pairing and the spin density wave. Two, we suggest that the models with different parameters are appropriate for different materials (or a material in different doped regions). This will lead to some new insights into the high temperature superconductors. It is shown that the SDW can appear at some temperature region when the on-site Coulomb interaction is larger, while the SC requires a decreased U at a lower temperature. This can qualitatively explain the relationship between superconducting and pseudogap states of Cu-based superconductors in underdoped and optimally doped regions. The superinsulator is also discussed.

Tian De Cao

2012-08-25T23:59:59.000Z

290

LATTICE QCD AT FINITE TEMPERATURE AND DENSITY.  

SciTech Connect (OSTI)

With the operation of the RHIC heavy ion program, the theoretical understanding of QCD at finite temperature and density has become increasingly important. Though QCD at finite temperature has been extensively studied using lattice Monte-Carlo simulations over the past twenty years, most physical questions relevant for RHIC (and future) heavy ion experiments remain open. In lattice QCD at finite temperature and density there have been at least two major advances in recent years. First, for the first time calculations of real time quantities, like meson spectral functions have become available. Second, the lattice study of the QCD phase diagram and equation of state have been extended to finite baryon density by several groups. Both issues were extensively discussed in the course of the workshop. A real highlight was the study of the QCD phase diagram in (T, {mu})-plane by Z. Fodor and S. Katz and the determination of the critical end-point for the physical value of the pion mass. This was the first time such lattice calculations at, the physical pion mass have been performed. Results by Z Fodor and S. Katz were obtained using a multi-parameter re-weighting method. Other determinations of the critical end point were also presented, in particular using a Taylor expansion around {mu} = 0 (Bielefeld group, Ejiri et al.) and using analytic continuation from imaginary chemical potential (Ph. de Forcrand and O. Philipsen). The result based on Taylor expansion agrees within errors with the new prediction of Z. Fodor and S. Katz, while methods based on analytic continuation still predict a higher value for the critical baryon density. Most of the thermodynamics studies in full QCD (including those presented at this workshop) have been performed using quite coarse lattices, a = 0.2-0.3 fm. Therefore one may worry about cutoff effects in different thermodynamic quantities, like the transition temperature T{sub tr}. At the workshop U. Heller presented a study of the transition temperature for three different lattice spacings and performed a continuum extrapolation of T{sub tr} for the first time. Lattice calculations of the meson spectral functions were presented by M. Asakawa, S. Datta, E. Laermann and H. Matsufuru. These show that charmonia ground states ({eta}{sub c} and J/{psi}) continue to exist in the plasma at least up to a temperature of 1.7 T{sub tr}. At what temperature charmonia states cease to exist is not yet clear. Calculations presented by M. Asakawa show dissolution of the J/{psi} at T = 1.7 T{sub tr}, while the analysis presented H. Matsufuru provided evidence that ground state charmonia still exist at this temperature. S. Datta argued that the ground state charmonia is likely to dissolve only for temperatures T > 2.25 T{sub tr}, while the P-states are dissociated at, 1.1 T{sub tr}. It is also very interesting that, even in the case of light quarks, meson spectral functions show a resonance-like structure in the plasma phase (talk by E. Laermann). Finally attempts to calculate transport properties in the Quark Gluon Plasma were presented by S. Gupta. The workshop devoted special attention to the finite temperature modification of inter-quark forces and color screening, another area where considerable progress has been made in recent years (talks by 0. Kaczmarek, K. Petrov, O. Philipsen and F. Zantow). Many other new theoretical developments which cannot be discussed here were also presented on the workshop. Altogether the workshop was a great success, for which we thank all the participants.

BLUM,T.; CREUTZ,M.; PETRECZKY,P.

2004-02-24T23:59:59.000Z

291

Superfluid Local Density Approximation: A Density Functional Theory Approach to the Nuclear Pairing Problem  

E-Print Network [OSTI]

I describe the foundation of a Density Functional Theory approach to include pairing correlations, which was applied to a variety of systems ranging from dilute fermions, to neutron stars and finite nuclei. Ground state properties as well as properties of excited states and time-dependent phenomena can be achieved in this manner within a formalism based on microscopic input.

Aurel Bulgac

2012-04-10T23:59:59.000Z

292

Modeling of the anode side of a direct methanol fuel cell with analytical solutions  

E-Print Network [OSTI]

In this work, analytical solutions were derived (for any methanol oxidation reaction order) for the profiles of methanol concentration and proton current density by assuming diffusion mass transport mechanism, Tafel kinetics, and fast proton transport in the anodic catalyst layer of a direct methanol fuel cell. An expression for the Thiele modulus that allows to express the anodic overpotential as a function of the cell current, and kinetic and mass transfer parameters was obtained. For high cell current densities, it was found that the Thiele modulus ($\\phi^2$) varies quadratically with cell current density; yielding a simple correlation between anodic overpotential and cell current density. Analytical solutions were derived for the profiles of both local methanol concentration in the catalyst layer and local anodic current density in the catalyst layer. Under the assumptions of the model presented here, in general, the local methanol concentration in the catalyst layer cannot be expressed as an explicit fun...

Mosquera, Martín A

2010-01-01T23:59:59.000Z

293

Quantum coherent switch utilizing commensurate nanoelectrode and charge density periodicities  

DOE Patents [OSTI]

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.

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

2008-08-05T23:59:59.000Z

294

ORIGINAL PAPER BambooFiber Filled High Density Polyethylene Composites  

E-Print Network [OSTI]

ORIGINAL PAPER Bamboo­Fiber Filled High Density Polyethylene Composites: Effect of Coupling Springer Science+Business Media, LLC 2008 Abstract High density polyethylene (HDPE)/bamboo composites in the future study. Keywords Bamboo Á High density polyethylene Á Coupling treatment Á Nanoclay Introduction

295

HIGHLIGHT OF THE MONTH Orbital Functionals in Density Functional Theory  

E-Print Network [OSTI]

HIGHLIGHT OF THE MONTH Orbital Functionals in Density Functional Theory: The Optimized E#11;ectiveurzburg, Am Hubland, D-97074 Wurzburg, Germany The success of density functional theory hinges the development of modern density functional theory. In present-day language, the exact OEP should be called

Gross, E.K.U.

296

Electronic excitations in complex systems: beyond density functional theory  

E-Print Network [OSTI]

Electronic excitations in complex systems: beyond density functional theory for real materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3 Time-dependent density functional theory 19 3.1 The Runge-Gross theorem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 4 Model kernels from many-body perturbation theory 29 4.1 Time-dependent density functional theory

Botti, Silvana

297

A Guided Tour of TimeDependent Density Functional Theory  

E-Print Network [OSTI]

A Guided Tour of Time­Dependent Density Functional Theory Kieron Burke 1 and E.K.U. Gross 2 1 outlook. 1 Introduction and User's Guide Density functional theory is the study of the one in density functional theory, driven largely by its applications in quantum chemistry[3]. This is due

Gross, E.K.U.

298

EFFECTIVE MAXWELL EQUATIONS FROM TIME-DEPENDENT DENSITY FUNCTIONAL THEORY  

E-Print Network [OSTI]

EFFECTIVE MAXWELL EQUATIONS FROM TIME-DEPENDENT DENSITY FUNCTIONAL THEORY WEINAN E, JIANFENG LU and magnetic fields are derived starting from time-dependent density functional theory. Effective permittivity with the density functional theory [2­4] instead of the many-body Schr¨odinger or Dirac equations. This is because

Bigelow, Stephen

299

Density Functional Theory applied to the solid state...  

E-Print Network [OSTI]

Density Functional Theory applied to the solid state... An introduction to VASP Jeremie Zaffran 2nd Marom (PhD) #12;Contents I- DFT and its functionals A. On the density functional theory... B #12;I- DFT and its functionals #12;I-DFT and its functionals A- On the density functional theory Why

Adler, Joan

300

Benchmark density functional theory calculations for nanoscale conductance  

E-Print Network [OSTI]

Benchmark density functional theory calculations for nanoscale conductance M. Strange,a I. S. The transmission functions are calculated using two different density functional theory methods, namely state density functional theory DFT . The resulting NEGF- DFT formalism provides a numerically efficient

Thygesen, Kristian

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We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

1 Density Functional Theory for Emergents Robert O. Jones  

E-Print Network [OSTI]

1 Density Functional Theory for Emergents Robert O. Jones Peter-Gr¨unberg-Institut PGI-1 and German the widespread use of density functional (DF) theory in materials science and chemistry and the physical insight as basic variable 3 3 An "approximate practical method" 5 4 Density functional formalism 7 4.1 Single

302

THE MANY-ELECTRON ENERGY IN DENSITY FUNCTIONAL THEORY  

E-Print Network [OSTI]

THE MANY-ELECTRON ENERGY IN DENSITY FUNCTIONAL THEORY From Exchange-Correlation Functional Design to the configuration of its electrons. Computer programs based on density functional theory (DFT) can calculate applicable within the field of computational density functional theory. Sammanfattning Att förutsäga

Armiento, Rickard

303

Time Dependent Density Functional Theory Applications, limitations and ... new frontiers  

E-Print Network [OSTI]

Time Dependent Density Functional Theory Applications, limitations and ... new frontiers Francesco Spectroscopy Facility (ETSF) Vienna, 19 January 2007 1/55 Time Dependent Density Functional Theory Francesco Sottile #12;Time-Dependent Density Functional Theory Applications and results: The ETSF Outline 1 Time

Botti, Silvana

304

RELATIVISTIC DENSITY FUNCTIONAL THEORY: FOUNDATIONS AND BASIC FORMALISM  

E-Print Network [OSTI]

1 Chapter 10 RELATIVISTIC DENSITY FUNCTIONAL THEORY: FOUNDATIONS AND BASIC FORMALISM E. Engela a An overview of relativistic density functional theory (RDFT) is presented with special emphasis on its field-Cluster schemes in recent years density functional theory (DFT) still represents the method of choice

Engel, Eberhard

305

Inverse diffusion from knowledge of power densities Guillaume Bal  

E-Print Network [OSTI]

asymptotic expansions and (Fourier) transformation, this allow us to construct the power density) provides access to the power density H(x) = (x)|u|2 (x) for all x inside the domain of interestInverse diffusion from knowledge of power densities Guillaume Bal , Eric Bonnetier , Fran

Bal, Guillaume

306

Density of the Values Set of the Tau Function  

E-Print Network [OSTI]

It is shown that the density of the values set {Tau(n): n > x/log x. The currently known density is #{Tau(n) : n > x^(1/2+o(1)), and the expected density is #{Tau(n) : n 2, which arises as a singular case of this analysis, is discussed within.

N. A. Carella

2014-04-10T23:59:59.000Z

307

E-Print Network 3.0 - atomic oxygen densities Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

densities Search Powered by Explorit Topic List Advanced Search Sample search results for: atomic oxygen densities...

308

E-Print Network 3.0 - atomic oxygen density Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

density Search Powered by Explorit Topic List Advanced Search Sample search results for: atomic oxygen density...

309

Gluon condensation and deconfinement critical density in nuclear matter  

E-Print Network [OSTI]

An upper limit to the critical density for the transition to the deconfined phase, at zero temperature, has been evaluated by analyzing the behavior of the gluon condensate in nuclear matter. Due to the non linear baryon density effects, the upper limit to the critical density, \\rho_c turns out about nine times the saturation density, rho_0 for the value of the gluon condensate in vacuum =0.012 GeV^4. For neutron matter \\rho_c \\simeq 8.5 \\rho_0. The dependence of the critical density on the value of the gluon condensate in vacuum is studied.

M. Baldo; P. Castorina; D. Zappala'

2004-10-07T23:59:59.000Z

310

Fuel cell tubes and method of making same  

DOE Patents [OSTI]

A method of manufacturing porous ceramic tubes for fuel cells with improved properties and higher manufacturing yield is disclosed. The method involves extruding a closed end fuel cell tube, such as an air electrode of a solid oxide fuel cell, in which the closed end also functions as the sintering support. The resultant fuel cell tube has a superior porosity distribution which allows improved diffusion of oxygen at the closed end of the tube during operation of the fuel cell. Because this region has the highest current density, performance enhancement and improved reliability of the fuel cell tube result. Furthermore, the higher manufacturing yield associated with the present method decreases the overall fuel cell cost. A method of manufacturing porous ceramic tubes for fuel cells with improved properties and higher manufacturing yield is disclosed. The method involves extruding a closed end fuel cell tube, such as an air electrode of a solid oxide fuel cell, in which the closed end also functions as the sintering support. The resultant fuel cell tube has a superior porosity distribution which allows improved diffusion of oxygen at the closed end of the tube during operation of the fuel cell. Because this region has the highest current density, performance enhancement and improved reliability of the fuel cell tube result. Furthermore, the higher manufacturing yield associated with the present method decreases the overall fuel cell cost.

Borglum, Brian P. (Edgewood, PA)

1999-11-30T23:59:59.000Z

311

Coarse-grained spin density-functional theory: infinite-volume limit via the hyperfinite  

E-Print Network [OSTI]

Coarse-grained spin density functional theory (SDFT) is a version of SDFT which works with number/spin densities specified to a limited resolution --- averages over cells of a regular spatial partition --- and external potentials constant on the cells. This coarse-grained setting facilitates a rigorous investigation of the mathematical foundations which goes well beyond what is currently possible in the conventional formualation. Problems of existence, uniqueness and regularity of representing potentials in the coarse-grained SDFT setting are here studied using techniques of (Robinsonian) nonstandard analysis. Every density which is nowhere spin-saturated is V-representable, and the set of representing potentials is the functional derivative, in an appropriate generalized sense, of the Lieb interal energy functional. Quasi-continuity and closure properties of the set-valued representing potentials map are also established. The extent of possible non-uniqueness is similar to that found in non-rigorous studies of the conventional theory, namely non-uniqueness can occur for states of collinear magnetization which are eigenstates of $S_z$.

Paul E. Lammert

2015-02-09T23:59:59.000Z

312

Building a Universal Nuclear Energy Density Functional  

SciTech Connect (OSTI)

During the period of Dec. 1 2006 – Jun. 30, 2012, the UNEDF collaboration carried out a comprehensive study of all nuclei, based on the most accurate knowledge of the strong nuclear interaction, the most reliable theoretical approaches, the most advanced algorithms, and extensive computational resources, with a view towards scaling to the petaflop platforms and beyond. The long-term vision initiated with UNEDF is to arrive at a comprehensive, quantitative, and unified description of nuclei and their reactions, grounded in the fundamental interactions between the constituent nucleons. We seek to replace current phenomenological models of nuclear structure and reactions with a well-founded microscopic theory that delivers maximum predictive power with well-quantified uncertainties. Specifically, the mission of this project has been three-fold: ? First, to find an optimal energy density functional (EDF) using all our knowledge of the nucleonic Hamiltonian and basic nuclear properties; ? Second, to apply the EDF theory and its extensions to validate the functional using all the available relevant nuclear structure and reaction data; ? Third, to apply the validated theory to properties of interest that cannot be measured, in particular the properties needed for reaction theory.

Carlson, Joe A. [Michigan State University; Furnstahl, Dick; Horoi, Mihai; Lust, Rusty; Nazaewicc, Witek; Ng, Esmond; Thompson, Ian; Vary, James

2012-12-30T23:59:59.000Z

313

Balanced homodyne detectors and Casimir energy densities  

E-Print Network [OSTI]

We recall and generalize the analysis of the output of the so-called balanced homodyne detectors. The most important feature of these detectors is their ability to quantify the vacuum fluctuations of the electric field, that is expectation values of products of (quantum-) electric-field operators. More precisely, the output of BHDs provides information on the one- and two-point functions of arbitrary states of quantum fields. We generalize the analysis of the response of BHDs to the case of quantum fields under influence of static external conditions such as cavities or polarizable media. By recalling the expressions for two-point functions of quantum fields in Casimir geometries we show, that a rich, position- and frequency-dependent pattern of BHD responses is predicted for ground states. This points to a potentially new characterization of quantum fields in Casimir setups which would not only complement the current global methods (Casimir forces), but also improve understanding of sub-vacuum energy densities present in some regions in these geometries.

P. Marecki

2008-03-22T23:59:59.000Z

314

Operator pencils on the algebra of densities  

E-Print Network [OSTI]

In this paper we continue to study equivariant pencil liftings and differential operators on the algebra of densities. We emphasize the role that the geometry of the extended manifold plays. Firstly we consider basic examples. We give a projective line of diff($M$)-equivariant pencil liftings for first order operators, and the canonical second order self-adjoint lifting. Secondly we study pencil liftings equivariant with respect to volume preserving transformations. This helps to understand the role of self-adjointness for the canonical pencils. Then we introduce the Duval-Lecomte-Ovsienko (DLO)-pencil lifting which is derived from the full symbol calculus of projective quantisation. We use the DLO-pencil lifting to describe all regular proj-equivariant pencil liftings. In particular the comparison of these pencils with the canonical pencil for second order operators leads to objects related to the Schwarzian. Within this paper the question of whether the pencil lifting factors through a full symbol map naturally arises.

A. Biggs; H. M. Khudaverdian

2014-10-15T23:59:59.000Z

315

Probing the density dependence of symmetry energy at subsaturation density with HICs  

E-Print Network [OSTI]

The reaction mechanism of the central collisions and peripheral collisions for $^{112,124}Sn+^{112,124}Sn$ at $E/A=50MeV$ is investigated within the framework of the Improved Quantum Molecular Dynamics model. The results show that multifragmentation process is an important mechanism at this energy region, and the influence of the cluster emission on the double n/p ratios and the isospin transport ratio are important. Furthermore, three observables, double n/p ratios, isospin diffusion and the rapidity distribution of the ratio $R_{7}$ for $^{112,124}Sn+^{112,124}Sn$ at E/A=50MeV are analyzed with the Improved Quantum Molecular Dynamics model. The results show that these three observables are sensitive to the density dependence of the symmetry energy. By comparing the calculation results to the data, the consistent constraint on the density dependence of the symmetry energy from these three observables is obtained.

Zhang, Yingxun; Li, Zhuxia; Danielewicz, P; Lynch, W G; Lu, Xiaohua

2009-01-01T23:59:59.000Z

316

Probing the density dependence of symmetry energy at subsaturation density with HICs  

E-Print Network [OSTI]

The reaction mechanism of the central collisions and peripheral collisions for $^{112,124}Sn+^{112,124}Sn$ at $E/A=50MeV$ is investigated within the framework of the Improved Quantum Molecular Dynamics model. The results show that multifragmentation process is an important mechanism at this energy region, and the influence of the cluster emission on the double n/p ratios and the isospin transport ratio are important. Furthermore, three observables, double n/p ratios, isospin diffusion and the rapidity distribution of the ratio $R_{7}$ for $^{112,124}Sn+^{112,124}Sn$ at E/A=50MeV are analyzed with the Improved Quantum Molecular Dynamics model. The results show that these three observables are sensitive to the density dependence of the symmetry energy. By comparing the calculation results to the data, the consistent constraint on the density dependence of the symmetry energy from these three observables is obtained.

Yingxun Zhang; M. B. Tsang; Zhuxia Li; P. Danielewicz; W. G. Lynch; Xiaohua Lu

2009-11-09T23:59:59.000Z

317

Structure formation: a spherical model for the evolution of the density distribution  

E-Print Network [OSTI]

Within the framework of hierarchical clustering we show that a simple Press-Schechter-like approximation, based on spherical dynamics, provides a good estimate of the evolution of the density field in the quasi-linear regime up to $\\Sigma \\sim 1$. Moreover, it allows one to recover the exact series of the cumulants of the probability distribution of the density contrast in the limit $\\Sigma \\to 0$ which sheds some light on the rigorous result and on ``filtering''. We also obtain similar results for the divergence of the velocity field. Next, we extend this prescription to the highly non-linear regime, using a stable-clustering approximation. Then we recover a specific scaling of the counts-in-cells which is indeed seen in numerical simulations, over a well-defined range. To this order we also introduce an explicit treatment of the behaviour of underdensities, which takes care of the normalization and is linked to the low-density bubbles and the walls one can see in numerical simulations. We compare this to a 1-dimensional adhesion model, and we present the consequences of our prescription for the power-law tail and the cutoff of the density distribution.

P. Valageas

1998-07-02T23:59:59.000Z

318

Miscibility, solubility, viscosity, and density measurements for R-236fa with potential lubricants. Final report  

SciTech Connect (OSTI)

The report gives results of miscibility, solubility, viscosity, and density measurements for refrigerant R-236fa and two potential lubricants. (The data are needed to determine the suitability of refrigerant/lubricant combinations for use in refrigeration systems.) The tested oils were pentaerythritol ester mixed-acid (ISO68), hereafter SW-68 manufactured by Castrol, and polyol ester mixed-acid (ISO46), hereafter Arctic-46 manufactured by Mobil. Miscibility was measured in a series of miniature test cells submerged in a constant temperature bath, precisely controlled over a temperature range of -50 to 90 C. Solubility, viscosity, and density data were also obtained for R-236fa mixed with the two oils for a refrigerant concentration of 0 to 40 wt % refrigerant over a temperature range of 30 to 100 C. This research shows that: (1) solubility, viscosity, and density are functions of temperature and concentration, (2) solubility increases with increasing temperature and refrigerant concentration (i.e., mass fraction of refrigerant). (3) viscosity decreases with increasing temperature and refrigerant concentration, and (4) density decreases with increasing temperature but increases with increasing refrigerant concentration. R-114 and naphthenic mineral oil were also tested.

Kang, H.M.; Pate, M.B.

1999-02-01T23:59:59.000Z

319

Current density partitioning in time-dependent current density functional theory  

SciTech Connect (OSTI)

We adapt time-dependent current density functional theory to allow for a fragment-based solution of the many-electron problem of molecules in the presence of time-dependent electric and magnetic fields. Regarding a molecule as a set of non-interacting subsystems that individually evolve under the influence of an auxiliary external electromagnetic vector-scalar potential pair, the partition 4-potential, we show that there are one-to-one mappings between this auxiliary potential, a sharply-defined set of fragment current densities, and the total current density of the system. The partition electromagnetic (EM) 4-potential is expressed in terms of the real EM 4-potential of the system and a gluing EM 4-potential that accounts for exchange-correlation effects and mutual interaction forces between fragments that are required to yield the correct electron dynamics. We prove the zero-force theorem for the fragmented system, establish a variational formulation in terms of action functionals, and provide a simple illustration for a charged particle in a ring.

Mosquera, Martín A. [Department of Chemistry, Purdue University, West Lafayette, Indiana 47907 (United States)] [Department of Chemistry, Purdue University, West Lafayette, Indiana 47907 (United States); Wasserman, Adam, E-mail: awasser@purdue.edu [Department of Chemistry, Purdue University, West Lafayette, Indiana 47907 (United States) [Department of Chemistry, Purdue University, West Lafayette, Indiana 47907 (United States); Department of Physics, Purdue University, West Lafayette, Indiana 47907 (United States)

2014-05-14T23:59:59.000Z

320

On direct and indirect methanol fuel cells for transportation applications  

SciTech Connect (OSTI)

Power densities in electrolyte Direct Methanol Fuel Cells have been achieved which are only three times lower than those achieved with similar reformate/air fuel cells. Remaining issues are: improved anode catalyst activity, demonstrated long-term stable performance, and high fuel efficiencies.

Ren, Xiaoming; Wilson, M.S.; Gottesfeld, S.

1995-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "density lithium-sulfur cells" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Fuel Cell Power Systems Analysis Patrick DavisPatrick Davis  

E-Print Network [OSTI]

Power Systems · Balance-of-plant (compressors, humidifiers, heat exchangers, sensors, controls) · Cost hydrogen 500020001000HoursDurability 45125325$/kWCost 325250140W/LPower density Operating on Tier 2 · Fuel Cell Vehicle Systems Analysis · Cost Analyses of Fuel Cell Stacks/ Systems · DFMA Cost Estimates

322

High energy density redox flow device  

DOE Patents [OSTI]

Redox flow devices are described including a positive electrode current collector, a negative electrode current collector, and an ion-permeable membrane separating said positive and negative current collectors, positioned and arranged to define a positive electroactive zone and a negative electroactive zone; wherein at least one of said positive and negative electroactive zone comprises a flowable semi-solid composition comprising ion storage compound particles capable of taking up or releasing said ions during operation of the cell, and wherein the ion storage compound particles have a polydisperse size distribution in which the finest particles present in at least 5 vol % of the total volume, is at least a factor of 5 smaller than the largest particles present in at least 5 vol % of the total volume.

Chiang, Yet-Ming; Carter, William Craig; Duduta, Mihai; Limthongkul, Pimpa

2014-05-13T23:59:59.000Z

323

Time-dependent density functional theory for ion diffusion in...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

The cell width, L, is defined by the distance accessible to the ion centers. (B) An equivalent circuit model for the electrochemical cell. system considered above, the EC...

324

Bonding Low-density Nanoporous Metal Foams Using Sputtered Solder  

SciTech Connect (OSTI)

A method has been developed for bonding low-density nanoporous metal foam components to a substrate using solder that is sputtered onto the surfaces. Metal foams have unusual properties that make them excellent choices for many applications, and as technologies for processing these materials are evolving, their use in industry is increasing dramatically. Metal foams are lightweight and have advantageous dynamic properties, which make them excellent choices for many structural applications. They also provide good acoustic damping, low thermal conductivity, and excellent energy absorption characteristics. Therefore, these materials are commonly used in the automotive, aerospace, construction, and biomedical industries. The synthesis of nanoporous metal foams with a cell size of less then 1 {micro}m is an emerging technology that is expected to lead to widespread application of metal foams in microdevices, such as sensors and actuators. One of the challenges to manufacturing components from metal foams is that they can be difficult to attach to other structures without degrading their properties. For example, traditional liquid adhesives cannot be used because they are absorbed into foams. The problem of bonding or joining can be particularly difficult for small-scale devices made from nanoporous foam, due to the requirement for a thin bond layer. The current study addresses this problem and develops a method of soldering a nanoporous metal foam to a substrate with a bond thickness of less than 2 {micro}m. There are many applications that require micro-scale metal foams precisely bonded to substrates. This study was motivated by a physics experiment that used a laser to drive a shock wave through an aluminum foil and into a copper foam, in order to determine the speed of the shock in the copper foam. To avoid disturbing the shock, the interface between the copper foam and the aluminum substrate had to be as thin as possible. There are many other applications that could benefit from the bonding technology developed in this study, such as small-scale lightweight structural members, high-strength thermal insulating layers for electronics, and micro-scale mechanical dampers, to name but a few. Each of these applications requires one or more small metal foam components precisely bonded to a substrate. Several methods for bonding metal foam components have been developed by previous researchers. Macroscopic metal foam parts have been successfully bonded by laser welding to create T-sections and butt joints. Ultrasonic welding has been used to join aluminum sheet metal to aluminum foam for structural applications. These methods work well for bonding large foam components, but reducing these methods to a smaller length scale would be challenging. One method that has shown great potential for bonding layers of metal foams to substrates is a brazing process that uses a sputter-deposited interface material. Shirzadi et al.[9] have demonstrated bonds between stainless steel foam and a stainless steel substrate using a layer of copper-titanium filler metal that is sputtered onto the interface surfaces. The foam pieces that they bonded were approximately 10 mm in diameter and 10 mm thick with a cell size of approximately 200 {micro}m. After depositing the filler material, pressing the materials together, and heating them with an induction heater, bonds were achieved without causing significant damage to the foam. The current study also uses a sputter-deposited interface material to bond foam to a substrate. However, in contrast to previous work, the current study examines bonding microscale pieces of fragile nanoporous metal foam. In this study, a method is developed to bond a thin sheet of fragile, low-density nanoporous copper foam to an aluminum foil substrate of thickness 40 {micro}m. By sputter depositing an indium-silver alloy onto the foam and the substrate, a solder joint with a thickness of less than 2 {micro}m was achieved.

Bono, M; Cervantes, O; Akaba, C; Hamza, A; Foreman, R; Teslich, N

2007-08-21T23:59:59.000Z

325

Textured-surface quartz resonator fluid density and viscosity monitor  

DOE Patents [OSTI]

A pair of thickness-shear mode resonators, one smooth and one with a textured surface, allows fluid density and viscosity to be independently resolved. A textured surface, either randomly rough or regularly patterned, leads to trapping of liquid at the device surface. The synchronous motion of this trapped liquid with the oscillating device surface allows the device to weigh the liquid; this leads to an additional response that depends on liquid density. This additional response enables a pair of devices, one smooth and one textured, to independently resolve liquid density and viscosity; the difference in responses determines the density while the smooth device determines the density-viscosity product, and thus, the pair determines both density and viscosity.

Martin, Stephen J. (Albuquerque, NM); Wiczer, James J. (Albuquerque, NM); Cernosek, Richard W. (Albuquerque, NM); Frye, Gregory C. (Cedar Crest, NM); Gebert, Charles T. (Albuquerque, NM); Casaus, Leonard (Bernalillo, NM); Mitchell, Mary A. (Tijeras, NM)

1998-08-25T23:59:59.000Z

326

Probabilistic Analysis of a Monod-type equation by use of a single chamber Microbial Fuel Cell  

E-Print Network [OSTI]

Probabilistic Analysis of a Monod-type equation by use of a single chamber Microbial Fuel Cell Eric for our society. Microbial fuel cells (MFCs) represent a new form of renewable energy by converting of a single chamber Microbial Fuel Cell affect the power density produced in the Microbial Fuel Cell

327

Method for measuring the density of lightweight materials  

DOE Patents [OSTI]

This invention relates to a nondestructive method for measuring the density of articles composed of elements having a low atomic number such as plastic and carbon composites. The measurement is accomplished by striking the article with a collimated beam of X radiation, simultaneously monitoring the radiation scattered and the radiation transmitted by the article, then relating the ratio of the radiation scattered to the radiation transmitted with the density of the article. The above method is insensitive to all variables except density.

Snow, Samuel G. (Oak Ridge, TN); Giacomelli, Edward J. (Knoxville, TN)

1980-01-01T23:59:59.000Z

328

Crystallization of polyethylene by modified weighted density approximation(MWDA)  

E-Print Network [OSTI]

In this article, we use the modified weighted density approximation to study the crystallization of polyethylene. We also use a direct correlation function of polyethylene based on RISM theory. The free energy of a polyethylene is calculated using density functional theory. The crystallization and solid and liquid density are calculated and finally compared with the prism simulation and experimental results. That shown the result obtained by MWDA is in better agreement, compared with the experimental result than the prism.

Razeghizadeh, Alireza; Lavafpour, Farhad

2015-01-01T23:59:59.000Z

329

Crystallization of polyethylene by modified weighted density approximation(MWDA)  

E-Print Network [OSTI]

In this article, we use the modified weighted density approximation to study the crystallization of polyethylene. We also use a direct correlation function of polyethylene based on RISM theory. The free energy of a polyethylene is calculated using density functional theory. The crystallization and solid and liquid density are calculated and finally compared with the prism simulation and experimental results. That shown the result obtained by MWDA is in better agreement, compared with the experimental result than the prism.

Alireza Razeghizadeh; Vahdat Rafee; Farhad Lavafpour

2015-02-07T23:59:59.000Z

330

Particle-Number Projection and the Density Functional Theory  

E-Print Network [OSTI]

In the framework of the Density Functional Theory for superconductors, we study the restoration of the particle number symmetry by means of the projection technique. Conceptual problems are outlined and numerical difficulties are discussed. Both are related to the fact that neither the many-body Hamiltonian nor the wave function of the system appear explicitly in the Density Functional Theory. Similar obstacles are encountered in self-consistent theories utilizing density-dependent effective interactions.

J. Dobaczewski; M. V. Stoitsov; W. Nazarewicz; P. -G. Reinhard

2007-08-03T23:59:59.000Z

331

Unambiguous exchange-correlation energy density Kieron Burke,a)  

E-Print Network [OSTI]

density approximation LDA , the conventional form is eXC unif (r) , the exchange-correlation energy the following definition of an energy density: eXC wave fn. r d3 r P r,r r r 2 r r 1 2 2 r,r s r,r r r , 2 whereUnambiguous exchange-correlation energy density Kieron Burke,a) Federico G. Cruz, and Kin-Chung Lam

Burke, Kieron

332

Nuclear symmetry energy at subnormal densities from measured nuclear masses  

E-Print Network [OSTI]

The symmetry energy coefficients for nuclei with mass number A=20~250 are extracted from more than 2000 measured nuclear masses. With the semi-empirical connection between the symmetry energy coefficients of finite nuclei and the nuclear symmetry energy at reference densities, we investigate the density dependence of symmetry energy of nuclear matter at subnormal densities. The obtained results are compared with those extracted from other methods.

Min Liu; Ning Wang; Zhuxia Li; Fengshou Zhang

2010-11-17T23:59:59.000Z

333

Electrochemical cell  

DOE Patents [OSTI]

An electrochemical cell is described having a bimodal positive electrode, a negative electrode of an alkali metal, and a compatible electrolyte including an alkali metal salt molten at the cell operating temperature. The positive electrode has an electrochemically active layer of at least one transition metal chloride at least partially present as a charging product, and additives of bromide and/or iodide and sulfur in the positive electrode or the electrolyte. Electrode volumetric capacity is in excess of 400 Ah/cm[sup 3]; the cell can be 90% recharged in three hours and can operate at temperatures below 160 C. There is also disclosed a method of reducing the operating temperature and improving the overall volumetric capacity of an electrochemical cell and for producing a positive electrode having a BET area greater than 6[times]10[sup 4] cm[sup 2]/g of Ni. 8 figures.

Redey, L.I.; Vissers, D.R.; Prakash, J.

1994-02-01T23:59:59.000Z

334

Zengcai Liu Postdoctoral Research Associate  

E-Print Network [OSTI]

for Lithium-Ion and Lithium Sulfur Batteries," ECS 220th Meeting, Boston, MA, Oct. 9-14, 2011. "Corrosion and electrolytes for lithium ion and lithium sulfur batteries; (2) the modification of polymer electrolyte) corrosion mechanism and protection strategies for various materials and devices. Professional Experience

Pennycook, Steve

335

SciTech Connect: Chiral dynamics and peripheral transverse densities  

Office of Scientific and Technical Information (OSTI)

in terms of frame-independent charge and magnetization densities in transverse space. This formulation allows one to identify the chiral components of nucleon structure as...

336

ATMOSPHERIC DENSITY ESTIMATION USING SATELLITE PRECISION ORBIT EPHEMERIDES  

E-Print Network [OSTI]

..................................................................................... 92 4.5.2 Density and Ballistic Coefficient Correlated Half-life Variation. ............................. 92 5 SUMMARY, CONCLUSIONS AND FUTURE WORK .............................. 93 5.1 Summary...

Arudra, Anoop Kumar

2011-04-22T23:59:59.000Z

337

Density Functional Theory Study of Oxygen Reduction Activity...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Study of Oxygen Reduction Activity on Ultrathin Platinum Nanotubes. Density Functional Theory Study of Oxygen Reduction Activity on Ultrathin Platinum Nanotubes. Abstract: The...

338

Engineering Density of States of Earth Abundant Semiconductors...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

of States of Earth Abundant Semiconductors for Enhanced Thermoelectric Power Factor Engineering Density of States of Earth Abundant Semiconductors for Enhanced Thermoelectric...

339

Relationship of Quantum Entanglement to Density Functional Theory  

E-Print Network [OSTI]

The maximum von Neumann entropy principle subject to given constraints of mean values of some physical observables determines the density matrix. Similarly the stationary action principle in the case of time-dependent (dissipative) situations under similar constraints yields the density matrix. The free energy and measures of entanglement are expressed in terms of such a density matrix and thus define respective functionals of the mean values. In the light of several model calculations, it is found that the density matrix contains information about both quantum entanglement and phase transitions even though there may not be any direct relationship implied by one on the other.

A. K. Rajagopal; R. W. Rendell

2005-12-13T23:59:59.000Z

340

Time-dependent density-functional theory for open systems  

E-Print Network [OSTI]

By introducing the self-energy density functionals for the dissipative interactions between the reduced system and its environment, we develop a time-dependent density-functional theory formalism based on an equation of motion for the Kohn-Sham reduced single-electron density matrix of the reduced system. Two approximate schemes are proposed for the self-energy density functionals, the complete second order approximation and the wide-band limit approximation. A numerical method based on the wide-band limit approximation is subsequently developed and implemented to simulate the steady and transient current through various realistic molecular devices. Simulation results are presented and discussed.

Xiao Zheng; Fan Wang; Chi Yung Yam; Yan Mo; GuanHua Chen

2007-02-27T23:59:59.000Z

Note: This page contains sample records for the topic "density lithium-sulfur cells" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

A New Computational Approach to Density Estimation with ...  

E-Print Network [OSTI]

which would be reasonably imposed on the density function. AIC (Akaike ..... The book [7] is a recent textbook in which theory, algorithms and applications are. 6 ...

2003-12-19T23:59:59.000Z

342

TEMPORAL VARIATIONS OF FRACTURE DIRECTIONS AND FRACTURE DENSITIES...  

Open Energy Info (EERE)

TEMPORAL VARIATIONS OF FRACTURE DIRECTIONS AND FRACTURE DENSITIES IN THE COSO GEOTHERMAL FIELD FROM ANALYSES OF SHEAR-WAVE SPLITTING Jump to: navigation, search OpenEI Reference...

343

A Comprehensive Study Of Fracture Patterns And Densities In The...  

Open Energy Info (EERE)

Study Of Fracture Patterns And Densities In The Geysers Geothermal Reservoir Using Microearthquake Shear-Wave Splitting Tomography Jump to: navigation, search OpenEI Reference...

344

Developing a Lower Cost and Higher Energy Density Alternative...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

for Advanced Batteries ADVANCED MANUFACTURING OFFICE Developing a Lower Cost and Higher Energy Density Alternative to Lithium-Ion Batteries Introduction As the world moves toward...

345

Constraints on the density dependence of the symmetry energy  

E-Print Network [OSTI]

Collisions involving 112Sn and 124Sn nuclei have been simulated with the improved Quantum Molecular Dynamics transport model. The results of the calculations reproduce isospin diffusion data from two different observables and the ratios of neutron and proton spectra. By comparing these data to calculations performed over a range of symmetry energies at saturation density and different representations of the density dependence of the symmetry energy, constraints on the density dependence of the symmetry energy at sub-normal density are obtained. Results from present work are compared to constraints put forward in other recent analysis.

M. B. Tsang; Yingxun Zhang; P. Danielewicz; M. Famiano; Zhuxia Li; W. G. Lynch; A. W. Steiner

2008-11-19T23:59:59.000Z

346

Constraints on the Density Dependence of the Symmetry Energy  

SciTech Connect (OSTI)

Collisions involving {sup 112}Sn and {sup 124}Sn nuclei have been simulated with the improved quantum molecular dynamics transport model. The results of the calculations reproduce isospin diffusion data from two different observables and the ratios of neutron and proton spectra. By comparing these data to calculations performed over a range of symmetry energies at saturation density and different representations of the density dependence of the symmetry energy, constraints on the density dependence of the symmetry energy at subnormal density are obtained. The results from the present work are compared to constraints put forward in other recent analyses.

Tsang, M. B.; Danielewicz, P.; Lynch, W. G.; Steiner, A. W. [Joint Institute of Nuclear Astrophysics and National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 (United States); Physics and Astronomy Department, Michigan State University, East Lansing, Michigan 48824 (United States); Zhang Yingxun [Joint Institute of Nuclear Astrophysics and National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 (United States); China Institute of Atomic Energy, P.O. Box 275 (18), Beijing 102413 (China); Famiano, M. [Physics Department, Western Michigan University, Kalamazoo, Michigan 49008 (United States); Li, Zhuxia [China Institute of Atomic Energy, P.O. Box 275 (18), Beijing 102413 (China)

2009-03-27T23:59:59.000Z

347

Constraints on the density dependence of the symmetry energy  

E-Print Network [OSTI]

Collisions involving 112Sn and 124Sn nuclei have been simulated with the improved Quantum Molecular Dynamics transport model. The results of the calculations reproduce isospin diffusion data from two different observables and the ratios of neutron and proton spectra. By comparing these data to calculations performed over a range of symmetry energies at saturation density and different representations of the density dependence of the symmetry energy, constraints on the density dependence of the symmetry energy at sub-normal density are obtained. Results from present work are compared to constraints put forward in other recent analysis.

Tsang, M B; Danielewicz, P; Famiano, M; Li, Zhuxia; Lynch, W G; Steiner, A W

2008-01-01T23:59:59.000Z

348

Density Functional Study of the Structure, Stability and Oxygen...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Study of the Structure, Stability and Oxygen Reduction Activity of Ultrathin Platinum Nanowires. Density Functional Study of the Structure, Stability and Oxygen Reduction Activity...

349

Innovative High Energy Density Capacitor Design Offers Potential...  

Broader source: Energy.gov (indexed) [DOE]

like TroyCap's High Density Energy Nanolaminate Capacitor (HEDCAP) that may offer new clean energy applications to meet the nation's strategic energy goals and secure...

350

COLD BUBBLE FORMATION DURING TOKAMAK DENSITY LIMIT DISRUPTIONS  

E-Print Network [OSTI]

COLD BUBBLE FORMATION DURING TOKAMAK DENSITY LIMIT DISRUPTIONS J. HOWARD, M. PERSSON* Plasma Research Laboratory, Research School of Physical Sciences, Australian National University, Canberra

Howard, John

351

Generation of high-energy-density ion bunches by ultraintense laser-cone-target interaction  

SciTech Connect (OSTI)

A scheme in which carbon ion bunches are accelerated to a high energy and density by a laser pulse (?10{sup 21}?W/cm{sup 2}) irradiating cone targets is proposed and investigated using particle-in-cell simulations. The laser pulse is focused by the cone and drives forward an ultrathin foil located at the cone's tip. In the course of the work, best results were obtained employing target configurations combining a low-Z cone with a multispecies foil transversely shaped to match the laser intensity profile.

Yang, X. H.; Zhuo, H. B., E-mail: hongbin.zhuo@gmail.com; Ma, Y. Y.; Zou, D. B.; Yu, T. P.; Ge, Z. Y.; Yin, Y.; Shao, F. Q. [College of Science, National University of Defense Technology, Changsha 410073 (China); Yu, W. [Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); Xu, H., E-mail: xuhanemail@gmail.com [State Key Laboratory of High Performance Computing, National University of Defense Technology, Changsha 410073 (China); Borghesi, M., E-mail: m.borghesi@qub.ac.uk [School of Mathematics and Physics, Queen's University of Belfast, Belfast BT7 1NN (United Kingdom); Institute of Physics of the ASCR, ELI-Beamlines Project, Na Slovance 2, 18221 Prague (Czech Republic)

2014-06-15T23:59:59.000Z

352

Differential white cell count by centrifugal microfluidics.  

SciTech Connect (OSTI)

We present a method for counting white blood cells that is uniquely compatible with centrifugation based microfluidics. Blood is deposited on top of one or more layers of density media within a microfluidic disk. Spinning the disk causes the cell populations within whole blood to settle through the media, reaching an equilibrium based on the density of each cell type. Separation and fluorescence measurement of cell types stained with a DNA dye is demonstrated using this technique. The integrated signal from bands of fluorescent microspheres is shown to be proportional to their initial concentration in suspension. Among the current generation of medical diagnostics are devices based on the principle of centrifuging a CD sized disk functionalized with microfluidics. These portable 'lab on a disk' devices are capable of conducting multiple assays directly from a blood sample, embodied by platforms developed by Gyros, Samsung, and Abaxis. [1,2] However, no centrifugal platform to date includes a differential white blood cell count, which is an important metric complimentary to diagnostic assays. Measuring the differential white blood cell count (the relative fraction of granulocytes, lymphocytes, and monocytes) is a standard medical diagnostic technique useful for identifying sepsis, leukemia, AIDS, radiation exposure, and a host of other conditions that affect the immune system. Several methods exist for measuring the relative white blood cell count including flow cytometry, electrical impedance, and visual identification from a stained drop of blood under a microscope. However, none of these methods is easily incorporated into a centrifugal microfluidic diagnostic platform.

Sommer, Gregory Jon; Tentori, Augusto M.; Schaff, Ulrich Y.

2010-07-01T23:59:59.000Z

353

Surface properties of liquid mercury: a comparison of density-dependent and density-independent force fields  

E-Print Network [OSTI]

The surface properties of liquid mercury (Hg) at a temperature of 293 K are investigated by classical Molecular Dynamics simulation using density-independent (DI) and density-dependent (DD) force fields. The latter force fields were introduced to improve the description of surface properties. Both force fields yield lower values of the surface tension in comparison to experimental data. Moreover, the density-dependent force field results in an anomalous thermodynamic behavior. These findings are rationalized by liquid-state theory. An optimized, density-independent force field is proposed that yields a higher surface tension and, at the same time, provides an accurate description of the liquid-vapor coexistence.

A. Iakovlev; D. Bedrov; M. Müller

2014-12-08T23:59:59.000Z

354

Power-law tails in probability density functions of molecular cloud column density  

E-Print Network [OSTI]

Power-law tails are often seen in probability density functions (PDFs) of molecular cloud column densities, and have been attributed to the effect of gravity. We show that extinction PDFs of a sample of five molecular clouds obtained at a few tenths of a parsec resolution, probing extinctions up to A$_{{\\mathrm{V}}}$ $\\sim$ 10 magnitudes, are very well described by lognormal functions provided that the field selection is tightly constrained to the cold, molecular zone and that noise and foreground contamination are appropriately accounted for. In general, field selections that incorporate warm, diffuse material in addition to the cold, molecular material will display apparent core+tail PDFs. The apparent tail, however, is best understood as the high extinction part of a lognormal PDF arising from the cold, molecular part of the cloud. We also describe the effects of noise and foreground/background contamination on the PDF structure, and show that these can, if not appropriately accounted for, induce spurious ...

Brunt, Chris

2015-01-01T23:59:59.000Z

355

High Power Impulse Magnetron Sputtering deposition of Pt inside fuel cell electrodes  

E-Print Network [OSTI]

1 High Power Impulse Magnetron Sputtering deposition of Pt inside fuel cell electrodes S Cuynet1 as a cathode of a proton exchange membrane fuel cell. An increase of 80 % at 0.65 V of the PEMFC power density) 272001" #12;2 Proton exchange membrane fuel cells (PEMFC) have the potential to provide

Paris-Sud XI, Université de

356

Simulation of the Buxton-Clarke Model for Organic Photovoltaic Cells  

E-Print Network [OSTI]

Simulation of the Buxton-Clarke Model for Organic Photovoltaic Cells J.W. Jerome Department 02912 USA Abstract--Modeling of organic photovoltaic (OPV) cells can be achieved by adaptation of drift-V curves and carrier current densities. I. INTRODUCTION Organic solar cells are the topic of extensive

Jerome, Joseph W.

357

Ultrasonic backscatter coefficient quantitative estimates from Chinese hamster ovary cell pellet biophantoms  

E-Print Network [OSTI]

Ultrasonic backscatter coefficient quantitative estimates from Chinese hamster ovary cell pellet August 2010; accepted 6 August 2010 A cell pellet biophantom technique is introduced, and applied verification purposes. BSC estimates from CHO cell pellet biophantoms of known number density were performed

Illinois at Urbana-Champaign, University of

358

Author's personal copy Performance of an alkaline-acid direct ethanol fuel cell  

E-Print Network [OSTI]

Author's personal copy Performance of an alkaline-acid direct ethanol fuel cell L. An, T.S. Zhao ethanol fuel cell Alkaline-acid Species concentrations Membrane thickness Power density a b s t r a c t This paper reports on the performance of an alkaline-acid direct ethanol fuel cell (AA-DEFC) that is composed

Zhao, Tianshou

359

Characterization of Limiting Factors in Laminar Flow-Based Membraneless Microfuel Cells  

E-Print Network [OSTI]

are underway to develop and optimize microscale fuel cells as high-energy-density power source alternatives, where fuel and oxidant are oxidized and re- duced, respectively, is essential for fuel cell optimization reports the analysis of a microflu- idic fuel cell based on laminar flow using an external reference

Kenis, Paul J. A.

360

Growth of Pt nanoparticle for proton-exchange-membrane fuel cells by  

E-Print Network [OSTI]

at anode side of a polymer electrolyte membrane (PEM) fuel cell. With a Pt loading of 25 g-Pt/cm2 , current, PEM fuel cell, Mass specific power density, Electrochemical active surface area, Oxygen reduction PEMFC Growth of Pt nanoparticle for proton-exchange-membrane fuel cells

Note: This page contains sample records for the topic "density lithium-sulfur cells" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Stresa, Italy, 26-28 April 2006 RECENT DEVELOPMENTS IN MEMS-BASED MICRO FUEL CELLS  

E-Print Network [OSTI]

cell achieved a maximum power density of 58 mW cm-2 at room temperature with hydrogen as fuel. 1Stresa, Italy, 26-28 April 2006 RECENT DEVELOPMENTS IN MEMS-BASED MICRO FUEL CELLS Tristan Pichonat ABSTRACT Micro fuel cells (µ-FC) represent promising power sources for portable applications. Today, one

Boyer, Edmond

362

Compacted carbon for electrochemical cells  

DOE Patents [OSTI]

This invention provides compacted carbon that is useful in the electrode of an alkali metal/carbon electrochemical cell of improved capacity selected from the group consisting of: (a) coke having the following properties: (1) an x-ray density of at least 2.00 grams per cubic centimeters, (2) a closed porosity of no greater than 5%, and (3) an open porosity of no greater than 47%; and (b) graphite having the following properties: (1) an x-ray density of at least 2.20 grams per cubic centimeters, (2) a closed porosity of no greater than 5%, and (3) an open porosity of no greater than 25%. This invention also relates to an electrode for an alkali metal/carbon electrochemical cell comprising compacted carbon as described above and a binder. This invention further provides an alkali metal/carbon electrochemical cell comprising: (a) an electrode as described above, (b) a non-aqueous electrolytic solution comprising an organic aprotic solvent and an electrolytically conductive salt and an alkali metal, and (c) a counter electrode. 10 figs.

Greinke, R.A.; Lewis, I.C.

1997-10-14T23:59:59.000Z

363

Note: A real-time beam current density meter  

SciTech Connect (OSTI)

We have developed a real-time beam current density meter for charged particle beams. It measures the mean current density by collimating a uniform and large diameter primary beam. The suppression of the secondary electrons and the deflection of the beam were simulated, and it was tested with a 105 keV Ar{sup 7+} ion beam.

Liu Junliang; Yu Deyang; Ruan Fangfang; Xue Yingli; Wang Wei [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)

2013-03-15T23:59:59.000Z

364

THERMAL CONDUCTIVITY OF HEMP CONCRETES: VARIATION WITH FORMULATION, DENSITY AND  

E-Print Network [OSTI]

envelope and on the performance of systems. This behaviour is related to hygric and thermal propertiesTHERMAL CONDUCTIVITY OF HEMP CONCRETES: VARIATION WITH FORMULATION, DENSITY AND WATER CONTENT of formulation, density and water content on the thermal conductivity of hemp concretes. The investigations

365

The MSW effect in a fluctuating matter density  

E-Print Network [OSTI]

We consider the effect on matter-enhanced neutrino flavor transformation of a randomly fluctuating, delta-correlated matter density. The fluctuations will produce a distribution of neutrino survival probabilities. We find the mean and variance of the distribution for the case of solar neutrinos, and discuss the possibility of placing a limit on solar density fluctuations using neutrino data.

A. B. Balantekin; J. M. Fetter; F. N. Loreti

1996-04-11T23:59:59.000Z

366

THE STAR FORMATION LAW AT LOW SURFACE DENSITY  

SciTech Connect (OSTI)

We investigate the nature of the star formation law at low gas surface densities using a sample of 19 low surface brightness (LSB) galaxies with existing H I maps in the literature, UV imaging from the Galaxy Evolution Explorer satellite, and optical images from the Sloan Digital Sky Survey. All of the LSB galaxies have (NUV - r) colors similar to those for higher surface brightness star-forming galaxies of similar luminosity indicating that their average star formation histories are not very different. Based upon four LSB galaxies with both UV and far-infrared (FIR) data, we find FIR/UV ratios significantly less than 1, implying low amounts of internal UV extinction in LSB galaxies. We use the UV images and H I maps to measure the star formation rate (SFR) and hydrogen gas surface density within the same region for all the galaxies. The LSB galaxy star formation rate surface densities lie below the extrapolation of the power law fit to the SFR surface density as a function of the total gas density for higher surface brightness galaxies. Although there is more scatter, the LSB galaxies also lie below a second version of the star formation law in which the SFR surface density is correlated with the gas density divided by the orbital time in the disk. The downturn seen in both star formation laws is consistent with theoretical models that predict lower star formation efficiencies in LSB galaxies due to the declining molecular fraction with decreasing density.

Wyder, Ted K.; Martin, D. Christopher; Barlow, Tom A.; Foster, Karl; Friedman, Peter G.; Morrissey, Patrick; Neill, James D. [California Institute of Technology, MC 278-17, 1200 E. California Blvd., Pasadena, CA 91125 (United States); Neff, Susan G. [Laboratory for Astronomy and Solar Physics, NASA Goddard Space Flight Center, Greenbelt, MD, 20771 (United States); Schiminovich, David [Department of Astronomy, Columbia University, New York, NY 10027 (United States); Seibert, Mark; Madore, Barry F. [Observatories of the Carnegie Institution of Washington, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Bianchi, Luciana [Center for Astrophysical Sciences, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218 (United States); Donas, Jose; Milliard, Bruno [Laboratoire d'Astrophysique de Marseille, BP 8, Traverse du Siphon, 13376 Marseille Cedex 12 (France); Heckman, Timothy M.; Szalay, Alex S. [Department of Physics and Astronomy, Johns Hopkins University, Homewood Campus, Baltimore, MD 21218 (United States); Lee, Young-Wook; Yi, Sukyoung K. [Center for Space Astrophysics, Yonsei University, Seoul 120-749 (Korea, Republic of); Rich, R. Michael [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States)

2009-05-10T23:59:59.000Z

367

High density Integrated Optoelectronic Circuits for High Speed Photonic Microsystems  

E-Print Network [OSTI]

High density Integrated Optoelectronic Circuits for High Speed Photonic Microsystems K. Minoglou.minoglou@imel.demorkitos.gr Abstract. The study of high density integrated optoelectronic circuits involves the development of hybrid integration technologies and the generation of models for the optoelectronic devices. To meet these goals

Kouroupetroglou, Georgios

368

Relativistic plasma nanophotonics for ultrahigh energy density physics  

E-Print Network [OSTI]

Relativistic plasma nanophotonics for ultrahigh energy density physics Michael A. Purvis1 volumetrically heat dense matter into a new ultrahot plasma regime. Electron densities nearly 100 times greater) and gigabar press- ures only exceeded in the central hot spot of highly compressed thermonuclear fusion

Rocca, Jorge J.

369

SUPPRESSION OF DIELECTRONIC RECOMBINATION DUE TO FINITE DENSITY EFFECTS  

SciTech Connect (OSTI)

We have developed a general model for determining density-dependent effective dielectronic recombination (DR) rate coefficients in order to explore finite-density effects on the ionization balance of plasmas. Our model consists of multiplying by a suppression factor those highly-accurate total zero-density DR rate coefficients which have been produced from state-of-the-art theoretical calculations and which have been benchmarked by experiment. The suppression factor is based upon earlier detailed collision-radiative calculations which were made for a wide range of ions at various densities and temperatures, but used a simplified treatment of DR. A general suppression formula is then developed as a function of isoelectronic sequence, charge, density, and temperature. These density-dependent effective DR rate coefficients are then used in the plasma simulation code Cloudy to compute ionization balance curves for both collisionally ionized and photoionized plasmas at very low (n{sub e} = 1 cm{sup -3}) and finite (n{sub e} = 10{sup 10} cm{sup -3}) densities. We find that the denser case is significantly more ionized due to suppression of DR, warranting further studies of density effects on DR by detailed collisional-radiative calculations which utilize state-of-the-art partial DR rate coefficients. This is expected to impact the predictions of the ionization balance in denser cosmic gases such as those found in nova and supernova shells, accretion disks, and the broad emission line regions in active galactic nuclei.

Nikolic, D.; Gorczyca, T. W.; Korista, K. T. [Western Michigan University, Kalamazoo, MI (United States); Ferland, G. J. [University of Kentucky, Lexington, KY (United States); Badnell, N. R. [University of Strathclyde, Glasgow (United Kingdom)

2013-05-01T23:59:59.000Z

370

Irradiation effects in high-density polyethylene Jussi Polvia  

E-Print Network [OSTI]

Irradiation effects in high-density polyethylene Jussi Polvia , Kai Nordlunda a simulations, we have studied the irradiation effects in high density polyethylene. We determined the threshold energy for creating defects in the polyethylene lattice as a function of the incident angle. We found

Nordlund, Kai

371

Complex structure of electron and density functional theory  

E-Print Network [OSTI]

Effective model for electron as two particle system is considered. The first particle in the system is chargeless mass of electron. The second one is massless charge of electron. Based on this model it is shown that density of energy for the particle is proportional to the probability density and the following formula stands $\\rho_E(x)=mc^2\\rho(x)$.

K. Koshelev

2013-01-08T23:59:59.000Z

372

Density functional theory for self-bound systems  

E-Print Network [OSTI]

The density functional theory is extended to account for self-bound systems. To this end the Hohenberg-Kohn theorem is formulated for the intrinsic density and a Kohn-Sham like procedure for an $N$--body system is derived using the adiabatic approximation to account for the center of mass motion.

Nir Barnea

2007-11-06T23:59:59.000Z

373

Connections on statistical manifolds of density operators by geometry of  

E-Print Network [OSTI]

of statistical manifolds, that is of manifolds whose points can be identified with density functions with respect to a certain measure µ. The classical references for the theory can be found in the books [1, 2, 4Connections on statistical manifolds of density operators by geometry of noncommutative Lp -spaces

Isola, Tommaso

374

Envelope of Fracture Density Dragana Todorovic-Marinic*  

E-Print Network [OSTI]

Envelope of Fracture Density Dragana Todorovic-Marinic* Veritas DGC Ltd., Calgary, Alberta, Canada that interpretation of fractures can be improved by using the envelope of the fracture density. It has been shown that open, fluid (or gas) filled fractures can be identified through the use of the AVAZ method (Gray et. al

Santos, Juan

375

Statistical inference for density dependent Markovian forestry models  

E-Print Network [OSTI]

Statistical inference for density dependent Markovian forestry models Abstract A stochastic forestry model with a density-dependence structure is studied. The population evolves in discrete roughly speaking, becomes large. From the perspective of the analysis of forestry data and predict

Paris-Sud XI, Université de

376

MARKOV CHAIN APPROXIMATIONS FOR TRANSITION DENSITIES OF LEVY PROCESSES  

E-Print Network [OSTI]

MARKOV CHAIN APPROXIMATIONS FOR TRANSITION DENSITIES OF L´EVY PROCESSES ALEKSANDAR MIJATOVI for the existence of transition densities of X, we establish sharp convergence rates of the normalised probability class with applications in diverse areas such as mathematical finance, risk management, insurance

377

Locating a Recycling Center: The General Density Case Jannett Highfill  

E-Print Network [OSTI]

Locating a Recycling Center: The General Density Case Jannett Highfill Department of Economics) 677-3374. #12;2 Locating a Recycling Center: The General Density Case Abstract: The present paper considers a municipality that has a landfill (fixed in location) and plans to optimally locate a "recycling

Mou, Libin

378

CONCRETE OPTIMISATION WITH REGARD TO PACKING DENSITY AND RHEOLOGY  

E-Print Network [OSTI]

/organizers): .............. Keywords: packing density, rheology, grading curve, optimisation, self-compacting concrete, roller-compactedCONCRETE OPTIMISATION WITH REGARD TO PACKING DENSITY AND RHEOLOGY François de Larrard LCPC Centre concrete. Author contacts Authors E-Mail Fax Postal address LCPC Centre de Nantes François de Larrard

Paris-Sud XI, Université de

379

Density-Enthalpy Phase Diagram 0D Boiler Simulation  

E-Print Network [OSTI]

Diagram 0D Boiler Simulation Finite Element Method Further Research Mass and Heat balances V d dt = i - eDensity-Enthalpy Phase Diagram 0D Boiler Simulation Finite Element Method Further Research Finite Transitions #12;Density-Enthalpy Phase Diagram 0D Boiler Simulation Finite Element Method Further Research

Vuik, Kees

380

Systems, methods and computer-readable media for modeling cell performance fade of rechargeable electrochemical devices  

DOE Patents [OSTI]

A system includes an electrochemical cell, monitoring hardware, and a computing system. The monitoring hardware periodically samples performance characteristics of the electrochemical cell. The computing system determines cell information from the performance characteristics of the electrochemical cell. The computing system also develops a mechanistic level model of the electrochemical cell to determine performance fade characteristics of the electrochemical cell and analyzing the mechanistic level model to estimate performance fade characteristics over aging of a similar electrochemical cell. The mechanistic level model uses first constant-current pulses applied to the electrochemical cell at a first aging period and at three or more current values bracketing a first exchange current density. The mechanistic level model also is based on second constant-current pulses applied to the electrochemical cell at a second aging period and at three or more current values bracketing the second exchange current density.

Gering, Kevin L

2013-08-27T23:59:59.000Z

Note: This page contains sample records for the topic "density lithium-sulfur cells" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Symmetry Energy as a Function of Density and Mass  

E-Print Network [OSTI]

Energy in nuclear matter is, in practice, completely characterized at different densities and asymmetries, when the density dependencies of symmetry energy and of energy of symmetric matter are specified. The density dependence of the symmetry energy at subnormal densities produces mass dependence of nuclear symmetry coefficient and, thus, can be constrained by that latter dependence. We deduce values of the mass dependent symmetry coefficients, by using excitation energies to isobaric analog states. The coefficient systematic, for intermediate and high masses, is well described in terms of the symmetry coefficient values of a_a^V=(31.5-33.5) MeV for the volume coefficient and a_a^S=(9-12) MeV for the surface coefficient. These two further correspond to the parameter values describing density dependence of symmetry energy, of L~95 MeV and K_{sym}~25 MeV.

Pawel Danielewicz; Jenny Lee

2007-08-21T23:59:59.000Z

382

Symmetry Energy as a Function of Density and Mass  

SciTech Connect (OSTI)

Energy in nuclear matter is, in practice, completely characterized at different densities and asymmetries, when the density dependencies of symmetry energy and of energy of symmetric matter are specified. The density dependence of the symmetry energy at subnormal densities produces mass dependence of nuclear symmetry coefficient and, thus, can be constrained by that latter dependence. We deduce values of the mass dependent symmetry coefficients, by using excitation energies to isobaric analog states. The coefficient systematic, for intermediate and high masses, is well described in terms of the symmetry coefficient values of a{sub a}{sup V} = (31.5-33.5) MeV for the volume coefficient and a{sub a}{sup S} = (9-12) MeV for the surface coefficient. These two further correspond to the parameter values describing density dependence of symmetry energy, of L{approx}95 MeV and K{sub sym}{approx}25 MeV.

Danielewicz, Pawel; Lee, Jenny [National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824 (United States)

2007-10-26T23:59:59.000Z

383

Symmetry Energy as a Function of Density and Mass  

E-Print Network [OSTI]

Energy in nuclear matter is, in practice, completely characterized at different densities and asymmetries, when the density dependencies of symmetry energy and of energy of symmetric matter are specified. The density dependence of the symmetry energy at subnormal densities produces mass dependence of nuclear symmetry coefficient and, thus, can be constrained by that latter dependence. We deduce values of the mass dependent symmetry coefficients, by using excitation energies to isobaric analog states. The coefficient systematic, for intermediate and high masses, is well described in terms of the symmetry coefficient values of a_a^V=(31.5-33.5) MeV for the volume coefficient and a_a^S=(9-12) MeV for the surface coefficient. These two further correspond to the parameter values describing density dependence of symmetry energy, of L~95 MeV and K_{sym}~25 MeV.

Danielewicz, Pawel

2007-01-01T23:59:59.000Z

384

TESTING AND PERFORMANCE ANALYSIS OF NASA 5 CM BY 5 CM BI-SUPPORTED SOLID OXIDE ELECTROLYSIS CELLS OPERATED IN BOTH FUEL CELL AND STEAM ELECTROLYSIS MODES  

SciTech Connect (OSTI)

A series of 5 cm by 5 cm bi-supported Solid Oxide Electrolysis Cells (SOEC) were produced by NASA for the Idaho National Laboratory (INL) and tested under the INL High Temperature Steam Electrolysis program. The results from the experimental demonstration of cell operation for both hydrogen production and operation as fuel cells is presented. An overview of the cell technology, test apparatus and performance analysis is also provided. The INL High Temperature Steam Electrolysis laboratory has developed significant test infrastructure in support of single cell and stack performance analyses. An overview of the single cell test apparatus is presented. The test data presented in this paper is representative of a first batch of NASA's prototypic 5 cm by 5 cm SOEC single cells. Clearly a significant relationship between the operational current density and cell degradation rate is evident. While the performance of these cells was lower than anticipated, in-house testing at NASA Glenn has yielded significantly higher performance and lower degradation rates with subsequent production batches of cells. Current post-test microstructure analyses of the cells tested at INL will be published in a future paper. Modification to cell compositions and cell reduction techniques will be altered in the next series of cells to be delivered to INL with the aim to decrease the cell degradation rate while allowing for higher operational current densities to be sustained. Results from the testing of new batches of single cells will be presented in a future paper.

R. C. O'Brien; J. E. O'Brien; C. M. Stoots; X. Zhang; S. C. Farmer; T. L. Cable; J. A. Setlock

2011-11-01T23:59:59.000Z

385

Electrochemical cell  

DOE Patents [OSTI]

An electrochemical cell is described having an alkali metal negative electrode such as sodium and a positive electrode including Ni or transition metals, separated by a [beta] alumina electrolyte and NaAlCl[sub 4] or other compatible material. Various concentrations of a bromine, iodine and/or sulfur containing additive and pore formers are disclosed, which enhance cell capacity and power. The pore formers may be the ammonium salts of carbonic acid or a weak organic acid or oxamide or methylcellulose. 6 figs.

Redey, L.I.; Vissers, D.R.; Prakash, J.

1994-08-23T23:59:59.000Z

386

Electrochemical cell  

DOE Patents [OSTI]

An improved secondary electrochemical cell is disclosed having a negative electrode of lithium aluminum, a positive electrode of iron sulfide, a molten electrolyte of lithium chloride and potassium chloride, and the combination that the fully charged theoretical capacity of the negative electrode is in the range of 0.5-1.0 that of the positive electrode. The cell thus is negative electrode limiting during discharge cycling. Preferably, the negative electrode contains therein, in the approximate range of 1-10 volume % of the electrode, an additive from the materials of graphitized carbon, aluminum-iron alloy, and/or magnesium oxide.

Kaun, Thomas D. (New Lenox, IL)

1984-01-01T23:59:59.000Z

387

Effect of scale up, stacking, self humidification and use of lightweight components on the performance of a proton exchange membrane fuel cell  

E-Print Network [OSTI]

The effects of various design and operating variables on the performances of a PEM fuel cell were investigated. Performance was evaluated in terms of the polarization curves (cell potential versus current density plots). The specific effects...

Tran, Doanh Thuc

2012-06-07T23:59:59.000Z

388

Running heading: Bulk density of a clayey subsoil Increase in the bulk density of a Grey Clay subsoil by  

E-Print Network [OSTI]

1 Running heading: Bulk density of a clayey subsoil Increase in the bulk density of a Grey Clay of the prisms were coated by material similar in composition to the topsoil and separated from as the profile dries over summer leading to widening of cracks between prismatic peds, (2) infilling of cracks

Boyer, Edmond

389

A High Power-Density Mediator-Free Microfluidic Biophotovoltaic Device for Cyanobacterial Cells  

E-Print Network [OSTI]

¨ller, L. Rajah, J. N. Skepper, M. Vendrus- colo, and T. P. J. Knowles, Appl Phys Lett 102, 184102 (2013). 39T. Yagishita, S. Sawayama, K.-I. Tsukahara, and T. Ogi, Bio- electrochem Bioenerg 43, 177 (1997). 40M. Torimura, A. Miki, A. Wadano, K. Kano, and T...

Bombelli, Paolo; Mueller, Thomas; Herling, Therese W.; Howe, Christopher J.; Knowles, Tuomas P. J.

2014-09-16T23:59:59.000Z

390

Quantification of Nanoscale Density Fluctuations in Biological Cells/Tissues: Inverse Participation Ratio (IPR) Analysis of  

E-Print Network [OSTI]

Ratio (IPR) Analysis of Transmission Electron Microscopy Images and Implications for Early-Stage Cancer analysis of the inverse participation ratio (IPR) of the eigenfunctions of these optical lattices at the nanoscales. First, the IPR analysis is validated in experiments with models of disordered systems fabricated

Pradhan, Prabhakar

391

ACTIVE CATHODES FOR SUPER-HIGH POWER DENSITY SOLID OXIDE FUEL CELLS THROUGH SPACE CHARGE EFFECTS  

SciTech Connect (OSTI)

This report summarizes the work done during the sixth quarter of the project. Effort was directed in three areas: (1) Further development of the model on the role of connectivity on ionic conductivity of porous bodies, including the role of grain boundaries and space charge region. (2) Calculation of the effect of space charge and morphology of porous bodies on the effective charge transfer resistance of porous composite cathodes. (3) The investigation of the three electrode system for the measurement of cathodic polarization using amperometric sensors.

Anil V. Virkar

2004-05-17T23:59:59.000Z

392

Cell Analysis … High-Energy Density Cathodes and Anodes | Department of  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-Up fromDepartmentTieCelebrate Earth Day with Secretary ChuEnergy Analysis …

393

Development of Large Format Lithium Ion Cells with Higher Energy Density  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-UpHeat Pump Models |Conduct, Parent CompanyaUSAMP AMD 602 - High-VolumeDepartment

394

Durability of Low Pt Fuel Cells Operating at High Power Density |  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-UpHeat Pump Models |Conduct, Parent(CRADA andDriving Innovation atDumping09

395

Design of Safer High-Energy Density Materials for Lithium-Ion Cells |  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-UpHeat Pump Models |Conduct, Parent Company Agrees toDepartment ofof3, 2015Department of

396

MEMS Fuel Cells--Low Temp--High Power Density - Energy Innovation Portal  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: VegetationEquipment Surfaces and InterfacesAdministration -Lowell L. Wood,3,March 26,

397

Density functional theory and evolution algorithm calculations of elastic properties of AlON  

SciTech Connect (OSTI)

Different models for aluminum oxynitride (AlON) were calculated using density functional theory and optimized using an evolutionary algorithm. Evolutionary algorithm and density functional theory (DFT) calculations starting from several models of AlON with different Al or O vacancy locations and different positions for the N atoms relative to the vacancy were carried out. The results show that the constant anion model [McCauley et al., J. Eur. Ceram. Soc. 29(2), 223 (2009)] with a random distribution of N atoms not adjacent to the Al vacancy has the lowest energy configuration. The lowest energy structure is in a reasonable agreement with experimental X-ray diffraction spectra. The optimized structure of a 55 atom unit cell was used to construct 220 and 440 atom models for simulation cells using DFT with a Gaussian basis set. Cubic elastic constant predictions were found to approach the experimentally determined AlON single crystal elastic constants as the model size increased from 55 to 440 atoms. The pressure dependence of the elastic constants found from simulated stress-strain relations were in overall agreement with experimental measurements of polycrystalline and single crystal AlON. Calculated IR intensity and Raman spectra are compared with available experimental data.

Batyrev, I. G.; Taylor, D. E.; Gazonas, G. A.; McCauley, J. W. [U.S. Army Research Laboratory, Aberdeen Proving Ground, Maryland 21005 (United States)

2014-01-14T23:59:59.000Z

398

Photovoltaic cell  

DOE Patents [OSTI]

In a photovoltaic cell structure containing a visibly transparent, electrically conductive first layer of metal oxide, and a light-absorbing semiconductive photovoltaic second layer, the improvement comprising a thin layer of transition metal nitride, carbide or boride interposed between said first and second layers.

Gordon, Roy G. (Cambridge, MA); Kurtz, Sarah (Somerville, MA)

1984-11-27T23:59:59.000Z

399

Propulsion alternatives for an undersea autonomous vehicle. Master's thesis  

SciTech Connect (OSTI)

A study was conducted to determine suitable energy systems for small undersea autonomous vehicles. The two main goals of this study were: (1) to evaluate energy systems able to provide 16 kW-hr for a vehicle of specified dimensions, and; (2) to evaluate energy systems that may be used in the future for longer-duration, higher-speed missions. It was concluded that silver-zinc secondary batteries are satisfactory for the low-energy requirement. There is some uncertainty about the most-suitable energy source for the higher-energy mission. There are no fully developed systems completely safe, reliable, and readily available for use. Lithium thionyl chloride batteries, and lithium sulfur hexafluoride thermal power plants are the main contenders and have comparable energy densities. There are concerns, however, about the safety and availability of each of these systems.

Braun, J.L.

1987-06-01T23:59:59.000Z

400

Constraining the nuclear symmetry-energy at super-density  

E-Print Network [OSTI]

The nuclear symmetry-energy has broad implications in both nuclear physics and astrophysics. Due to hard work of many people, the nuclear symmetry-energy around saturation density has been roughly constrained. However, the nuclear symmetry-energy at super-density is still in chaos. By considering both the effects of the nucleon-nucleon short-rang correlations and the isospin-dependent in-medium inelastic baryon-baryon scattering cross sections in the transport model, two unrelated experimental measurements are simultaneously analyzed. A soft symmetry-energy at super-density is first consistently obtained by the double comparison of the symmetry-energy sensitive observables.

Yong, Gao-Chan

2015-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "density lithium-sulfur cells" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Nuclear Energy Density Functionals Constrained by Low-Energy QCD  

E-Print Network [OSTI]

A microscopic framework of nuclear energy density functionals is reviewed, which establishes a direct relation between low-energy QCD and nuclear structure, synthesizing effective field theory methods and principles of density functional theory. Guided by two closely related features of QCD in the low-energy limit: a) in-medium changes of vacuum condensates, and b) spontaneous breaking of chiral symmetry; a relativistic energy density functional is developed and applied in studies of ground-state properties of spherical and deformed nuclei.

Dario Vretenar

2008-02-06T23:59:59.000Z

402

Symmetry energy at subnuclear densities deduced from nuclear masses  

E-Print Network [OSTI]

We examine how nuclear masses are related to the density dependence of the symmetry energy. Using a macroscopic nuclear model we calculate nuclear masses in a way dependent on the equation of state of asymmetric nuclear matter. We find by comparison with empirical two-proton separation energies that a smaller symmetry energy at subnuclear densities, corresponding to a larger density symmetry coefficient L, is favored. This tendency, which is clearly seen for nuclei that are neutron-rich, nondeformed, and light, can be understood from the property of the surface symmetry energy in a compressible liquid-drop picture.

Kazuhiro Oyamatsu; Kei Iida

2010-04-19T23:59:59.000Z

403

The value of density measurements in stellar coronae  

E-Print Network [OSTI]

The grating instruments on board Chandra and XMM-Newton now allow measurements of electron densities. These rely on the ratios of fluxes in emission lines, where one line depends on both collisional and radiative decay rates. The electron density is required to constrain the physical extent of the emitting region, and large samples of measurements are of interest in the context of trends in coronal activity. Here we discuss the important He {\\sc i}-like ions and the differences in densities that result when different current data bases are used.

Jan-Uwe Ness; Carole Jordan

2005-04-06T23:59:59.000Z

404

Energy Density Inhomogeneities with Polynomial $f(R)$ Cosmology  

E-Print Network [OSTI]

In this paper, we study the effects of polynomial $f(R)$ model on the stability of homogeneous energy density in self-gravitating spherical stellar object. For this purpose, we construct couple of evolution equations which relate the Weyl tensor with matter parameters. We explore different factors responsible for density inhomogeneities with non-dissipative dust, isotropic as well as anisotropic fluids and dissipative dust cloud. We find that shear, pressure, dissipative parameters and $f(R)$ terms affect the existence of inhomogeneous energy density.

Sharif, M

2015-01-01T23:59:59.000Z

405

Unbiased estimators of wildlife population densities using aural information  

E-Print Network [OSTI]

. Using L' = 1. 99, and p = 1/3, from (30) an estimate of the density is n 108. 85 f A ] 99(3)(4QQQ)(] /3) . 0136 dove pairs/acre s = 1. 36 dove pairs/100 acres. 25 This is the same estimate we obtained using DI. The reason for this is explained...(7. 50) 1. 12 ? (2 422) (3) (40) (1(3) (0. 96, l. 28) 3. 4 Suggestions for Improvements At present, the call-count technique for estimating the density of mourning doves seems satisfactory for establishing a relative density index, but to get a good...

Durland, Eric Newton

1969-01-01T23:59:59.000Z

406

Novel and Optimized Materials Phases for High Energy Density Batteries  

Broader source: Energy.gov [DOE]

2013 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting

407

Nanocrystal Solar Cells  

E-Print Network [OSTI]

research on organic photovoltaic cells since small molecule10 years prior (4). Photovoltaic cells with an active layerof the associated photovoltaic cells. 2.4 Charge transport

Gur, Ilan

2006-01-01T23:59:59.000Z

408

Nanocrystal Solar Cells  

E-Print Network [OSTI]

Nov, 2005). Chapter 4 Hybrid solar cells with 3-dimensionalinorganic nanocrystal solar cells 5.1 Introduction In recentoperation of organic based solar cells and distinguish them

Gur, Ilan

2006-01-01T23:59:59.000Z

409

Hydrogen Fuel Cell Vehicles  

E-Print Network [OSTI]

Research Institute 1990 Fuel Cell Status," Proceedings ofMiller, "Introduction: Fuel-Cell-Powered Vehicle DevelopmentPrograms," presented at Fuel Cells for Transportation,

Delucchi, Mark

1992-01-01T23:59:59.000Z

410

Diagnostic Studies on Lithium Battery Cells and Cell Components...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Studies on Lithium Battery Cells and Cell Components Diagnostic Studies on Lithium Battery Cells and Cell Components 2012 DOE Hydrogen and Fuel Cells Program and Vehicle...

411

Fuel Cell Technologies Overview: 2011 Fuel Cell Seminar | Department...  

Broader source: Energy.gov (indexed) [DOE]

Fuel Cell Technologies Overview: 2011 Fuel Cell Seminar Fuel Cell Technologies Overview: 2011 Fuel Cell Seminar Presentation by Sunita Satyapal at the Fuel Cell Seminar on November...

412

Stationary Fuel Cells: Overview of Hydrogen and Fuel Cell Activities...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Stationary Fuel Cells: Overview of Hydrogen and Fuel Cell Activities Stationary Fuel Cells: Overview of Hydrogen and Fuel Cell Activities Presentation covers stationary fuel cells...

413

Uncertainty analysis of densities and isotopics: Handling correlations  

SciTech Connect (OSTI)

This paper discusses two cases of correlated parameters in uncertainty analyses: (1) the case of measured mass, density, and volume or spatial dimension correlations; and (2) the case of measured material isotopics, where increasing one atom fraction must cause the others to decrease. In the first case, an equation is derived that has a term due to uncertain density, a term due to uncertain dimensions, and a term due to the correlation between density and dimensions. In a numerical test problem, this equation gives the same result as the standard equation that treats mass and dimensions independently. In the case of isotopics, an equation is derived relating the uncertainty due to uncertain isotopic fractions to the sensitivities to isotopic densities, which are easier to calculate. The equation is verified in a test problem. (authors)

Favorite, J. A.; Armstrong, J. C. [X-Computational Physics Division, Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States); Burr, T. [Computer, Computational, and Statistical Sciences Division, Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States)

2013-07-01T23:59:59.000Z

414

Real time density functional simulations of quantum scale conductance  

E-Print Network [OSTI]

We study electronic conductance through single molecules by subjecting a molecular junction to a time dependent potential and propagating the electronic state in real time using time-dependent density functional theory ...

Evans, Jeremy Scott

2009-01-01T23:59:59.000Z

415

Density of states and order parameter in dirty anisotropic superconductors  

E-Print Network [OSTI]

We analyze in detail how the scattering by nonmagnetic impurities affects the shape and amplitude of the order parameter (OF) and the density of states in anisotropic superconductors in the framework of BCS theory. Special attention is paid...

Pokrovsky, SV; Pokrovsky, Valery L.

1996-01-01T23:59:59.000Z

416

Direct experimental determination of spectral densities of molecular complexes  

SciTech Connect (OSTI)

Determining the spectral density of a molecular system immersed in a proteomic scaffold and in contact to a solvent is a fundamental challenge in the coarse-grained description of, e.g., electron and energy transfer dynamics. Once the spectral density is characterized, all the time scales are captured and no artificial separation between fast and slow processes need to be invoked. Based on the fluorescence Stokes shift function, we utilize a simple and robust strategy to extract the spectral density of a number of molecular complexes from available experimental data. Specifically, we show that experimental data for dye molecules in several solvents, amino acid proteins in water, and some photochemical systems (e.g., rhodopsin and green fluorescence proteins), are well described by a three-parameter family of sub-Ohmic spectral densities that are characterized by a fast initial Gaussian-like decay followed by a slow algebraic-like decay rate at long times.

Pachón, Leonardo A. [Grupo de Física Atómica y Molecular, Instituto de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín (Colombia); Chemical Physics Theory Group, Department of Chemistry and Center for Quantum Information and Quantum Control, University of Toronto, Toronto, Ontario M5S 3H6 (Canada); Brumer, Paul [Chemical Physics Theory Group, Department of Chemistry and Center for Quantum Information and Quantum Control, University of Toronto, Toronto, Ontario M5S 3H6 (Canada)

2014-11-07T23:59:59.000Z

417

An evolutionary fuel assembly design for high power density BWRs  

E-Print Network [OSTI]

An evolutionary BWR fuel assembly design was studied as a means to increase the power density of current and future BWR cores. The new assembly concept is based on replacing four traditional assemblies and large water gap ...

Karahan, Aydin

2007-01-01T23:59:59.000Z

418

atheroprotective high-density lipoprotein: Topics by E-print...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

the mean-field energy functional. By studying the latter we derive global properties of high-density ground state configurations in bounded domains and in infinite space. Our main...

419

Why are Fluid Densities So Low in Carbon Nanotubes?  

E-Print Network [OSTI]

The equilibrium density of fluids under nanoconfinement can differ substantially from their bulk density. Using a mean-field approach to describe the energetic landscape near the carbon nanotube (CNT) wall, we obtain analytical results describing the lengthscales associated with the layering observed at the fluid-CNT interface. When combined with molecular simulation results for the fluid density in the layered region, this approach allows us to derive a closed-form prediction for the overall equilibrium fluid density as a function of the CNT radius that is in excellent agreement with molecular dynamics simulations. We also show how aspects of this theory can be extended to describe water confined within CNTs and find good agreement with results from the literature.

Gerald J. Wang; Nicolas G. Hadjiconstantinou

2014-09-27T23:59:59.000Z

420

Effect of Lithium PFC Coatings on NSTX Density Control  

SciTech Connect (OSTI)

Lithium coatings on the graphite plasma facing components (PFCs) in NSTX are being investigated as a tool for density profile control and reducing the recycling of hydrogen isotopes. Repeated lithium pellet injection into Center Stack Limited and Lower Single Null Ohmic Helium Discharges were used to coat graphite surfaces that had been pre-conditioned with Ohmic Helium Discharges of the same shape to reduce their contribution to hydrogen isotope recycling. The following deuterium NBI reference discharges exhibited a reduction in density by a factor of about 3 for limited and 2 for diverted plasmas respectively, and peaked density profiles. Recently, a lithium evaporator has been used to apply thin coatings on conditioned and unconditioned PFCs. Effects on the plasma density and the impurities were obtained by pre-conditioning the PFCs with ohmic helium discharges, and performing the first deuterium NBI discharge as soon as possible after applying the lithium coating.

Kugel, H W; Bell, M G; Bush, C; Gates, D; Gray, T; Kaita, R; Leblanc, B; Maingi, R; Majeski, R; Mansfield, D; Mueller, D; Raman, R; Roquemore, A L; Sabbagh, S; Skinner, C H; Soukhanovskii, V; Stevenson, T; Zakharov, L

2006-08-21T23:59:59.000Z

Note: This page contains sample records for the topic "density lithium-sulfur cells" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Urban characteristics attributable to density-driven tie formation  

E-Print Network [OSTI]

Motivated by empirical evidence on the interplay between geography, population density and societal interaction, we propose a generative process for the evolution of social structure in cities. Our analytical and simulation ...

Pan, Wei

422

Optimal-transport formulation of electronic density-functional theory  

E-Print Network [OSTI]

The most challenging scenario for Kohn-Sham density functional theory, that is when the electrons move relatively slowly trying to avoid each other as much as possible because of their repulsion (strong-interaction limit), is reformulated here as an optimal transport (or mass transportation theory) problem, a well established field of mathematics and economics. In practice, we show that solving the problem of finding the minimum possible internal repulsion energy for $N$ electrons in a given density $\\rho(\\rv)$ is equivalent to find the optimal way of transporting $N-1$ times the density $\\rho$ into itself, with cost function given by the Coulomb repulsion. We use this link to put the strong-interaction limit of density functional theory on firm grounds and to discuss the potential practical aspects of this reformulation.

Giuseppe Buttazzo; Luigi De Pascale; Paola Gori-Giorgi

2012-05-21T23:59:59.000Z

423

The design of high power density annular fuel for LWRs  

E-Print Network [OSTI]

Fuel performance models have been developed to assess the performance of internally and externally cooled LWR annular fuel. Such fuel may be operated at 30-50% higher core power density than the current operating LWRs, and ...

Yuan, Yi, 1975-

2004-01-01T23:59:59.000Z

424

Computing the Density of States of Boolean Formulas  

E-Print Network [OSTI]

Computing the Density of States of Boolean Formulas Stefano Ermon, Carla P. Gomes, and Bart Selman of configurations that violate exactly E clauses, for all values of E. We propose a novel Markov Chain Monte Carlo

Keinan, Alon

425

Does Cosmological Vacuum Energy Density have an Electric Reason ?  

E-Print Network [OSTI]

Rather uncomplicated calculations by hand display a surprising connection between the energy density of the vacuum and the diameter and age of the universe. Among other things, the result explains the observation of the accelerated expansion of the universe.

Claus W. Turtur

2004-03-11T23:59:59.000Z

426

Low density lipoprotein fraction assay for cardiac disease risk  

DOE Patents [OSTI]

A variable rate density gradient electrophoric gel is described which separates LDL subfractions with the precision of ultracentrifugation techniques. Also, an innovative bottom inlet mixing chamber particularly useful for producing these gels is described. 8 figs.

Krauss, R.M.; Blanche, P.J.; Orr, J.

1999-07-20T23:59:59.000Z

427

Direct Experimental Determination of Spectral Densities of Molecular Complexes  

E-Print Network [OSTI]

Determining the spectral density of a molecular system immersed in a proteomic scaffold and in contact to a solvent is a fundamental challenge in the coarse-grained description of, e.g., electron and energy transfer dynamics. Once the spectral density is characterized, all the time scales are captured and no artificial separation between fast and slow processes need be invoked. Based on the fluorescence Stokes shift function, we utilize a simple and robust strategy to extract the spectral density of a number of molecular complexes from available experimental data. Specifically, we show that experimental data for dye molecules in several solvents, amino acid proteins in water, and some photochemical systems (e.g., rhodopsin and green fluorescence proteins), are well described by a three-parameter family of sub-Ohmic spectral densities that are characterized by a fast initial Gaussian-like decay followed by a slow algebraic-like decay rate at long times.

Leonardo A. Pachon; Paul Brumer

2014-10-15T23:59:59.000Z

428

Measurements of neutral helium density in helicon plasmas  

SciTech Connect (OSTI)

Laser-induced-fluorescence (LIF) is used to measure the density of helium atoms in a helicon plasma source. For a pump wavelength of 587.725 nm (vacuum) and laser injection along the magnetic field, the LIF signal exhibits a signal decrease at the Doppler shifted central wavelength. The drop in signal results from the finite optical depth of the plasma and the magnitude of the decrease is proportional to the density of excited state neutral atoms. Using Langmuir probe measurements of plasma density and electron temperature and a collisional-radiative model, the absolute ground state neutral density is calculated from the optical depth measurements. Optimal plasma performance, i.e., the largest neutral depletion on the axis of the system, is observed for antenna frequencies of 13.0 and 13.5 MHz and magnetic field strengths of 550-600 G.

Houshmandyar, Saeid; Sears, Stephanie H.; Thakur, Saikat Chakraborty; Carr, Jerry Jr.; Galante, Matthew E.; Scime, Earl E. [Department of Physics, West Virginia University, Morgantown, West Virginia 26506-6315 (United States)

2010-10-15T23:59:59.000Z

429

A density functional study of actinyl containing complexes.  

E-Print Network [OSTI]

??Density functional (DFT) methods are first used to study 22 of the most stable solution-phase UN4O12 isomers containing uranyl nitrate, UO2(NO3)2. Based on relative free… (more)

Berard, Joel J.

2008-01-01T23:59:59.000Z

430

Deriving Atmospheric Density Estimates Using Satellite Precision Orbit Ephemerides  

E-Print Network [OSTI]

Model regardless of solar and geomagnetic activity levels. The POE density estimates were obtained with the desired accuracy for a ±10% variation in the ballistic coefficient used to initialize the process. Fit span length showed little influence...

Hiatt, Andrew Timothy

2009-01-01T23:59:59.000Z

431

Estimating Geometric Dislocation Densities in Polycrystalline Materialsfrom Orientation Imaging Microscopy  

SciTech Connect (OSTI)

Herein we consider polycrystalline materials which can be taken as statistically homogeneous and whose grains can be adequately modeled as rigid-plastic. Our objective is to obtain, from orientation imaging microscopy (OIM), estimates of geometrically necessary dislocation (GND) densities.

Man, Chi-Sing [University of Kentucky; Gao, Xiang [University of Kentucky; Godefroy, Scott [University of Kentucky; Kenik, Edward A [ORNL

2010-01-01T23:59:59.000Z

432

Diffusion driven object propulsion in density stratified fluids  

E-Print Network [OSTI]

An experimental study was conducted in order to verify the appropriateness of a two dimensional model of the flow creating diffusion driven object propulsion in density stratified fluids. Initial flow field experiments ...

Lenahan, Conor (Conor P.)

2009-01-01T23:59:59.000Z

433

A novel density of state method for complex action systems  

E-Print Network [OSTI]

Recently, a new and efficient algorithm (the LLR method) has been proposed for computing densities of states in statistical systems and gauge theories. In this talk, we explore whether this novel density of states method can be applied to numerical computations of observables in systems for which the action is complex. To this purpose, we introduce a generalised density of states, in terms of which integrals of oscillating observables can be determined semi-analytically, and we define a strategy to compute it with the LLR method. As a case study, we apply these ideas to the Z(3) spin model at finite density, finding a remarkable agreement of our results for the phase twist with those obtained with the worm algorithm for all explored chemical potentials, including values for which there are cancellations over sixteen orders of magnitude. These findings open new perspectives for dealing with the sign problem on physically more relevant systems.

Biagio Lucini; Kurt Langfeld

2014-11-01T23:59:59.000Z

434

Paper area density measurement from forward transmitted scattered light  

DOE Patents [OSTI]

A method whereby the average paper fiber area density (weight per unit area) can be directly calculated from the intensity of transmitted, scattered light at two different wavelengths, one being a non-absorpted wavelength. Also, the method makes it possible to derive the water percentage per fiber area density from a two-wavelength measurement. In the optical measuring technique optical transmitted intensity, for example, at 2.1 microns cellulose absorption line is measured and compared with another scattered, optical transmitted intensity reference in the nearby spectrum region, such as 1.68 microns, where there is no absorption. From the ratio of these two intensities, one can calculate the scattering absorption coefficient at 2.1 microns. This absorption coefficient at this wavelength is, then, experimentally correlated to the paper fiber area density. The water percentage per fiber area density can be derived from this two-wavelength measurement approach.

Koo, Jackson C. (San Ramon, CA)

2001-01-01T23:59:59.000Z

435

Low density lipoprotein fraction assay for cardiac disease risk  

DOE Patents [OSTI]

A variable rate density gradient electrophoric gel is described which separate LDL subfractions with the precision of ultracentrifugation techniques. Also, an innovative bottom inlet mixing chamber particularly useful for producing these gels is described.

Krauss, Ronald M. (Berkeley, CA); Blanche, Patricia J. (Berkeley, CA); Orr, Joseph (San Pablo, CA)

1999-01-01T23:59:59.000Z

436

From massive gravity to dark matter density II  

E-Print Network [OSTI]

As previously observed the massless limit of massive gravity leads to a modification of general relativity. Here we study spherically symmetric solutions of the modified field equations which contain normal matter together with a dark energy density. If the dark density profile is assumed to be known, the whole problem is reduced to a linear first order differential equation which can be solved by quadratures.

G. Scharf

2009-02-18T23:59:59.000Z

437

Density dependence of symmetry free energy of hot nuclei  

E-Print Network [OSTI]

The density and excitation energy dependence of symmetry energy and symmetry free energy for finite nuclei are calculated microscopically in a microcanonical framework taking into account thermal and expansion effects. A finite-range momentum and density dependent two-body effective interaction is employed for this purpose. The role of mass, isospin and equation of state (EoS) on these quantities is also investigated; our calculated results are in consonance with the available experimental data.

S. K. Samaddar; J. N. De; X. Vinas; M. Centelles

2008-09-04T23:59:59.000Z

438

Further Developments in Orbit Ephemeris Derived Neutral Density  

E-Print Network [OSTI]

/04/2002. ................................... 91 Figure 4.4 – Atmospheric Density Comparison for CHAMP on 04/17/2002. ................................... 92 Figure 4.5 – Atmospheric Density Comparison for GRACE on 08/04/2006. .................................... 93 Figure 4.6 – Atmospheric... sigma values. .... 88 Table 4.2 – Average CC values for CHAMP binned by solar activity level. ..................................... 96 Table 4.3 – Average RMS values (10-12 kg/m3) for CHAMP binned by solar activity level.............. 96 Table 4...

Locke, Travis Cole

2012-12-31T23:59:59.000Z

439

The benchmark of gutzwiller density functional theory in hydrogen systems  

SciTech Connect (OSTI)

We propose an approximate form of the exchange-correlation energy functional for the Gutzwiller density functional theory. It satisfies certain physical constraints in both weak and strong electron correlation limits. We benchmark the Gutzwiller density functional approximation in the hydrogen systems, where the static correlation error is shown to be negligible. The good transferability is demonstrated by applications to the hydrogen molecule and some crystal structures.

Yao, Y.; Wang, Cai-Zhuang; Ho, Kai-Ming

2012-02-23T23:59:59.000Z

440

Preface: Special Topic on Advances in Density Functional Theory  

SciTech Connect (OSTI)

This Special Topic Issue on the Advances in Density Functional Theory, published as a celebration of the fifty years of density functional theory, contains a retrospective article, a perspective article, and a collection of original research articles that showcase recent theoretical advances in the field. It provides a timely discussion reflecting a cross section of our understanding, and the theoretical and computational developments, which have significant implications in broad areas of sciences and engineering.

Yang, Weitao [Department of Chemistry and Department of Physics, Duke University, Durham, North Carolina 27708 (United States)] [Department of Chemistry and Department of Physics, Duke University, Durham, North Carolina 27708 (United States)

2014-05-14T23:59:59.000Z

Note: This page contains sample records for the topic "density lithium-sulfur cells" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Density Functional Theory with Dissipation: Transport through Single Molecules  

SciTech Connect (OSTI)

A huge amount of fundamental research was performed on this grant. Most of it focussed on fundamental issues of electronic structure calculations of transport through single molecules, using density functional theory. Achievements were: (1) First density functional theory with dissipation; (2) Pseudopotential plane wave calculations with master equation; (3) Weak bias limit; (4) Long-chain conductance; and (5) Self-interaction effects in tunneling.

Kieron Burke

2012-04-30T23:59:59.000Z

442

Dynamical density functional theory for colloidal particles with arbitrary shape  

E-Print Network [OSTI]

Starting from the many-particle Smoluchowski equation, we derive dynamical density functional theory for Brownian particles with an arbitrary shape. Both passive and active (self-propelled) particles are considered. The resulting theory constitutes a microscopic framework to explore the collective dynamical behavior of biaxial particles in nonequilibrium. For spherical and uniaxial particles, earlier derived dynamical density functional theories are recovered as special cases. Our study is motivated by recent experimental progress in preparing colloidal particles with many different biaxial shapes.

Raphael Wittkowski; Hartmut Löwen

2011-06-12T23:59:59.000Z

443

Molecular Binding Energies from Partition Density Functional Theory  

SciTech Connect (OSTI)

Approximate molecular calculations via standard Kohn-Sham density functional theory are exactly reproduced by performing self-consistent calculations on isolated fragments via partition density functional theory [P. Elliott, K. Burke, M. H. Cohen, and A. Wasserman, Phys. Rev. A 82, 024501 (2010)]. We illustrate this with the binding curves of small diatomic molecules. We find that partition energies are in all cases qualitatively similar and numerically close to actual binding energies. We discuss qualitative features of the associated partition potentials.

Nafziger, J.; Wu, Q.; Wasserman, A.

2011-12-21T23:59:59.000Z

444

Taming Density Functional Theory by Coarse-Graining  

E-Print Network [OSTI]

The standard (``fine-grained'') interpretation of quantum density functional theory, in which densities are specified with infinitely-fine spatial resolution, is mathematically unruly. Here, a coarse-grained version of DFT, featuring limited spatial resolution, and its relation to the fine-grained theory in the $L^1\\cap L^3$ formulation of Lieb, is studied, with the object of showing it to be not only mathematically well-behaved, but consonant with the spirit of DFT, practically (computationally) adequate and sufficiently close to the standard interpretation as to accurately reflect its non-pathological properties. The coarse-grained interpretation is shown to be a good model of formal DFT in the sense that: all densities are (ensemble)-V-representable; the intrinsic energy functional $F$ is a continuous function of the density and the representing external potential is the (directional) functional derivative of the intrinsic energy. Also, the representing potential $v[\\rho]$ is quasi-continuous, in that $v[\\rho]\\rho$ is continuous as a function of $\\rho$. The limit of coarse-graining scale going to zero is studied to see if convergence to the non-pathological aspects of the fine-grained theory is adequate to justify regarding coarse-graining as a good approximation. Suitable limiting behaviors or intrinsic energy, densities and representing potentials are found. Intrinsic energy converges monotonically, coarse-grained densities converge uniformly strongly to their low-intrinsic-energy fine-grainings, and $L^{3/2}+L^\\infty$ representability of a density is equivalent to the existence of a convergent sequence of coarse-grained potential/ground-state density pairs.

Paul E. Lammert

2010-08-10T23:59:59.000Z

445

Non-invasive fluid density and viscosity measurement  

DOE Patents [OSTI]

The noninvasively measurement of the density and viscosity of static or flowing fluids in a section of pipe such that the pipe performs as the sensing apparatus, is described. Measurement of a suitable structural vibration resonance frequency of the pipe and the width of this resonance permits the density and viscosity to be determined, respectively. The viscosity may also be measured by monitoring the decay in time of a vibration resonance in the pipe.

Sinha, Dipen N. (Los Alamos, NM)

2012-05-01T23:59:59.000Z

446

Density Evolution in the New Modified Chaplygin Gas Model  

E-Print Network [OSTI]

In this paper, we have considered new modified Chaplygin gas (NMCG) model which interpolates between radiation at early stage and $\\Lambda$CDM at late stage. This model is regarded as a unification of dark energy and dark matter (with general form of matter). We have derived the density parameters from the equation of motion for the interaction between dark energy and dark matter. Also we have studied the evolution of the various components of density parameters.

Surajit Chattopadhyay; Ujjal Debnath

2008-05-01T23:59:59.000Z

447

The Performance of Density Functionals for Sulfate-Water Clusters  

SciTech Connect (OSTI)

The performance of 24 density functionals, Hartree-Fock, and MP2 is assessed with respect to the energetics of 49 sulfate-water clusters with between three and six water molecules. Included among the density functionals are GGA, meta-GGA, hybrid GGA, hybrid meta-GGA, and double hybrid density functionals, as well as the LDA. Three types of dispersion corrections (VV10, XDM, and -D) are tested in conjunction with these functionals. The functionals are compared using the relative and binding energies of the sulfatewater clusters as the main criteria. It is discovered that a majority of current density functionals are unable to simultaneously capture the physics necessary to describe both the relative and binding energies of the anionic solvation clusters. The only density functionals that perform acceptably with respect to both measures are XYG3 and XYGJOS, primarily due to their balanced treatment of exchange and correlation. On the other hand, density functionals with exact exchange that lack nonlocal correlation tend to perform well only for the relative energies. However, there is evidence that hybrid density functionals that provide a more comprehensive treatment of local correlation through their dependence on the kinetic energy density and their ability to treat the inhomogeneities in the present system can partially resolve this issue. While dispersion correction functionals cannot replace the accuracy provided by MP2 correlation, it is shown that the proper combination of a hybrid GGA functional with a dispersion correction functional can lead to drastic improvements in the binding energies of the parent functional, while preserving its performance with respect to the relative energies.

Mardirossian, Narbe; Lambrecht, Daniel S.; McCaslin, Laura; Xantheas, Sotiris S.; Head-Gordon, Martin P.

2013-03-12T23:59:59.000Z

448

High energy-density water: density functional theory calculations of structure and electrical conductivity.  

SciTech Connect (OSTI)

Knowledge of the properties of water is essential for correctly describing the physics of shock waves in water as well as the behavior of giant planets. By using finite temperature density functional theory (DFT), we have investigated the structure and electronic conductivity of water across three phase transitions (molecular liquid/ ionic liquid/super-ionic/electronic liquid). There is a rapid transition to ionic conduction at 2000 K and 2 g/cm{sup 3} while electronic conduction dominates at temperatures above 6000 K. We predict that the fluid bordering the super-ionic phase is conducting above 4000 K and 100 GPa. Earlier work instead has the super-ionic phase bordering an insulating fluid, with a transition to metallic fluid not until 7000 K and 250 GPa. The tools and expertise developed during the project can be applied to other molecular systems, for example, methane, ammonia, and CH foam. We are now well positioned to treat also complex molecular systems in the HEDP regime of phase-space.

Desjarlais, Michael Paul; Mattsson, Thomas Kjell Rene

2006-03-01T23:59:59.000Z

449

Observation of low magnetic field density peaks in helicon plasma  

SciTech Connect (OSTI)

Single density peak has been commonly observed in low magnetic field (<100 G) helicon discharges. In this paper, we report the observations of multiple density peaks in low magnetic field (<100 G) helicon discharges produced in the linear helicon plasma device [Barada et al., Rev. Sci. Instrum. 83, 063501 (2012)]. Experiments are carried out using argon gas with m = +1 right helical antenna operating at 13.56 MHz by varying the magnetic field from 0 G to 100 G. The plasma density varies with varying the magnetic field at constant input power and gas pressure and reaches to its peak value at a magnetic field value of {approx}25 G. Another peak of smaller magnitude in density has been observed near 50 G. Measurement of amplitude and phase of the axial component of the wave using magnetic probes for two magnetic field values corresponding to the observed density peaks indicated the existence of radial modes. Measured parallel wave number together with the estimated perpendicular wave number suggests oblique mode propagation of helicon waves along the resonance cone boundary for these magnetic field values. Further, the observations of larger floating potential fluctuations measured with Langmuir probes at those magnetic field values indicate that near resonance cone boundary; these electrostatic fluctuations take energy from helicon wave and dump power to the plasma causing density peaks.

Barada, Kshitish K.; Chattopadhyay, P. K.; Ghosh, J.; Kumar, Sunil; Saxena, Y. C. [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)

2013-04-15T23:59:59.000Z

450

Testing gravity with halo density profiles observed through gravitational lensing  

SciTech Connect (OSTI)

We present a new test of the modified gravity endowed with the Vainshtein mechanism with the density profile of a galaxy cluster halo observed through gravitational lensing. A scalar degree of freedom in the galileon modified gravity is screened by the Vainshtein mechanism to recover Newtonian gravity in high-density regions, however it might not be completely hidden on the outer side of a cluster of galaxies. Then the modified gravity might yield an observational signature in a surface mass density of a cluster of galaxies measured through gravitational lensing, since the scalar field could contribute to the lensing potential. We investigate how the transition in the Vainshtein mechanism affects the surface mass density observed through gravitational lensing, assuming that the density profile of a cluster of galaxies follows the original Navarro-Frenk-White (NFW) profile, the generalized NFW profile and the Einasto profile. We compare the theoretical predictions with observational results of the surface mass density reported recently by other researchers. We obtain constraints on the amplitude and the typical scale of the transition in the Vainshtein mechanism in a subclass of the generalized galileon model.

Narikawa, Tatsuya; Yamamoto, Kazuhiro, E-mail: narikawa@theo.phys.sci.hiroshima-u.ac.jp, E-mail: kazuhiro@hiroshima-u.ac.jp [Department of Physical Science, Hiroshima University, Higashi-Hiroshima 739-8526 (Japan)

2012-05-01T23:59:59.000Z

451

Small-Scale Low Cost Solid Oxide Fuel Cell Power Systems  

SciTech Connect (OSTI)

Progress in tasks seeking greater cell power density and lower cost through new cell designs, new cell materials and lower operating temperature is summarized. The design of the program required Proof-of-Concept unit of residential capacity scale is reviewed along with a summary of results from its successful test. Attachment 1 summarizes the status of cell development. Attachment 2 summarizes the status of generator design, and Attachment 3 of BOP design.

S. D. Vora

2008-02-01T23:59:59.000Z

452

Solid oxide MEMS-based fuel cells  

DOE Patents [OSTI]

A micro-electro-mechanical systems (MEMS) based thin-film fuel cells for electrical power applications. The MEMS-based fuel cell may be of a solid oxide type (SOFC), a solid polymer type (SPFC), or a proton exchange membrane type (PEMFC), and each fuel cell basically consists of an anode and a cathode separated by an electrolyte layer. The electrolyte layer can consist of either a solid oxide or solid polymer material, or proton exchange membrane electrolyte materials may be used. Additionally catalyst layers can also separate the electrodes (cathode and anode) from the electrolyte. Gas manifolds are utilized to transport the fuel and oxidant to each cell and provide a path for exhaust gases. The electrical current generated from each cell is drawn away with an interconnect and support structure integrated with the gas manifold. The fuel cells utilize integrated resistive heaters for efficient heating of the materials. By combining MEMS technology with thin-film deposition technology, thin-film fuel cells having microflow channels and full-integrated circuitry can be produced that will lower the operating temperature an will yield an order of magnitude greater power density than the currently known fuel cells.

Jankowksi, Alan F.; Morse, Jeffrey D.

2007-03-13T23:59:59.000Z

453

Solid polymer MEMS-based fuel cells  

DOE Patents [OSTI]

A micro-electro-mechanical systems (MEMS) based thin-film fuel cells for electrical power applications. The MEMS-based fuel cell may be of a solid oxide type (SOFC), a solid polymer type (SPFC), or a proton exchange membrane type (PEMFC), and each fuel cell basically consists of an anode and a cathode separated by an electrolyte layer. The electrolyte layer can consist of either a solid oxide or solid polymer material, or proton exchange membrane electrolyte materials may be used. Additionally catalyst layers can also separate the electrodes (cathode and anode) from the electrolyte. Gas manifolds are utilized to transport the fuel and oxidant to each cell and provide a path for exhaust gases. The electrical current generated from each cell is drawn away with an interconnect and support structure integrated with the gas manifold. The fuel cells utilize integrated resistive heaters for efficient heating of the materials. By combining MEMS technology with thin-film deposition technology, thin-film fuel cells having microflow channels and full-integrated circuitry can be produced that will lower the operating temperature an will yield an order of magnitude greater power density than the currently known fuel cells.

Jankowski, Alan F. (Livermore, CA); Morse, Jeffrey D. (Pleasant Hill, CA)

2008-04-22T23:59:59.000Z

454

Durability Evaluation of Reversible Solid Oxide Cells  

SciTech Connect (OSTI)

An experimental investigation on the performance and durability of single solid oxide cells (SOCs) is under way at the Idaho National Laboratory. Reversible operation of SOCs includes electricity generation in the fuel cell mode and hydrogen generation in the electrolysis mode. Degradation is a more significant issue when operating SOCs in the electrolysis mode. In order to understand and mitigate the degradation issues in high temperature electrolysis, single SOCs with different configurations from several manufacturers have been evaluated for initial performance and long-term durability. A new test apparatus for single cell and small stack tests has been developed for this purpose. Cells were obtained from four industrial partners. Cells from Ceramatec Inc. and Materials and Systems Research Inc. (MSRI) showed improved durability in electrolysis mode compared to previous stack tests. Cells from Saint Gobain Advanced Materials Inc. (St. Gobain) and SOFCPower Inc. demonstrated stable performance in the fuel cell mode, but rapid degradation in the electrolysis mode, especially at high current density. Electrolyte-electrode delamination was found to have a significant impact on degradation in some cases. Enhanced bonding between electrolyte and electrode and modification of the electrode microstructure helped to mitigate degradation. Polarization scans and AC impedance measurements were performed during the tests to characterize cell performance and degradation.

Xiaoyu Zhang; James E. O'Brien; Robert C. O'Brien; Gregory K. Housley

2013-11-01T23:59:59.000Z

455

Direct Measurements of Pore Fluid Density by Vibrating Tube Densimetry  

SciTech Connect (OSTI)

The densities of pore-confined fluids were measured for the first time by means of a vibrating tube method. Isotherms of total adsorption capacity were measured directly making the method complementary to the conventional gravimetric or volumetric/piezometric adsorption techniques, which yield the excess adsorption (the Gibbsian surface excess). A custom-made high-pressure, high-temperature vibrating tube densimeter (VTD) was used to measure the densities of subcritical and supercritical propane (between 35 C and 97 C) and supercritical carbon dioxide (between 32 C and 50 C) saturating hydrophobic silica aerogel (0.2 g/cm3, 90% porosity) synthesized inside Hastelloy U-tubes. Additionally, excess adsorption isotherms for supercritical CO2 and the same porous solid were measured gravimetrically using a precise magnetically-coupled microbalance. Pore fluid densities and total adsorption isotherms increased monotonically with increasing density of the bulk fluid, in contrast to excess adsorption isotherms, which reached a maximum at a subcritical density of the bulk fluid, and then decreased towards zero or negative values at supercritical densities. Compression of the confined fluid significantly beyond the density of the bulk liquid at the same temperature was observed at subcritical temperatures. The features of the isotherms of confined fluid density are interpreted to elucidate the observed behavior of excess adsorption. The maxima of excess adsorption were found to occur below the critical density of the bulk fluid at the conditions corresponding to the beginning of the plateau of total adsorption, marking the end of the transition of pore fluid to a denser, liquid-like pore phase. The results for propane and carbon dioxide showed similarity in the sense of the principle of corresponding states. No measurable effect of pore confinement on the liquid-vapor critical point was found. Quantitative agreement was obtained between excess adsorption isotherms determined from VTD total adsorption results and those measured gravimetrically at the same temperature, confirming the validity of the vibrating tube measurements. Vibrating tube densimetry was demonstrated as a novel experimental approach capable of providing the average density of pore-confined fluids.

Gruszkiewicz, Miroslaw {Mirek} S [ORNL; Rother, Gernot [ORNL; Wesolowski, David J [ORNL; Cole, David R [ORNL; Wallacher, Dirk [Helmholtz-Zentrum Berlin

2012-01-01T23:59:59.000Z

456

Continuous-feed electrochemical cell with nonpacking particulate electrode  

DOE Patents [OSTI]

An electrochemical cell providing full consumption of electrochemically active particles in a nonpacking, electrolyte-permeable bed has a tapered cell cavity bounded by two nonparallel surfaces separated by a distance that promotes bridging of particles across the cavity. The gap/particle size ratio is maintained as the particles are consumed, decrease in size, and travel from the point of entry to the narrower end of the cell. A cell of this configuration supports a bed of low packing density maintained in a dynamic steady state by alternate formation and collapse of particle bridges across the gap and associated voids over the entire active area of the cell. The cell design can be applied to refuelable zinc/air cells and zinc/ferrocyanide storage batteries. 6 figs.

Cooper, J.F.

1995-07-18T23:59:59.000Z

457

Exploring the Potential for High-Quality Epitaxial CdTe Solar Cells , Ana Kanevce2  

E-Print Network [OSTI]

Exploring the Potential for High-Quality Epitaxial CdTe Solar Cells Tao Song1 , Ana Kanevce2 National Renewable Energy Laboratory, Golden, CO, 80401, USA Abstract -- Traditional polycrystalline CdTeV and ~ 20%. Epitaxial CdTe with high-quality, low defect-density, and high carrier density, could yield

Sites, James R.

458

Condensation of FtsZ filaments can drive bacterial cell division  

E-Print Network [OSTI]

Condensation of FtsZ filaments can drive bacterial cell division Ganhui Lana , Brian R. Danielsb-ring undergoes a condensation transition from a low- density state to a high-density state and generates the condensation transition, but does not directly generate forces. In vivo fluorescence measurements show that Fts

Sun, Sean

459

Electrochemistry Cell Model  

Broader source: Energy.gov (indexed) [DOE]

or exceeds all performance goals - Interpreting complex cell electrochemical phenomena - Identification of cell degradation mechanisms Partners (Collaborators) Daniel Abraham,...

460

Telecommunications International Cell Phone  

E-Print Network [OSTI]

Telecommunications International Cell Phone 1. Fax completed form to 979.847.1111. 2. If you do will be charged. Date Cell Phone Needed Cell Phone Pick-Up Date Cell Phone User Travel Destination(s) United States Number Destination Country Number Cell Phone Type Digital Satellite Cell Phone Return Date Notes

Note: This page contains sample records for the topic "density lithium-sulfur cells" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Generalized time-dependent density-functional-theory response functions for spontaneous density fluctuations and nonlinear response: Resolving the causality paradox in real time  

E-Print Network [OSTI]

Generalized time-dependent density-functional-theory response functions for spontaneous density shifted the focus of elec- tronic structure theory from the many-body wave function to the charge density response and spontaneous fluctuations of many-electron systems. The pth-order density response functions

Mukamel, Shaul

462

1 | Fuel Cell Technologies Program Source: US DOE 3/19/2013 eere.energy.gov Overview of Hydrogen &  

E-Print Network [OSTI]

and Workshops · Analysis Update · Recent HTAC Input & Future Needs Agenda #12;3 | Fuel Cell Technologies Program density and reduce fuel cell system cost by >45% since 2007. "Whiskerettes" of Pt grow off sides/07 ­ Carbon-Neutral Energy Research of Kyushu University · MotorWeek: PBS to air a fuel cell vehicle episode

463

The Star Formation Rate-Density Relationship at Redshift Three  

E-Print Network [OSTI]

We study the star formation rate (SFR) as a function of environment for UV selected Lyman break galaxies (LBGs) at redshift three. From deep UBVI KPNO 4-m/MOSAIC images, covering a total of 0.90 deg^2, we select 334 LBGs in slices 100 Mpc (co-moving) deep spanning the redshift range 2.9projected density to the 5th nearest neighbor. These mock catalogs have a redshift depth of 100 Mpc, similar to our slice width. The large area of the MOSAIC images, 40x40 Mpc (co-moving) per field, allows us to measure the SFR from the dust-corrected UV continuum as a function of $\\Sigma_5$. In contrast to low-redshift galaxies, we find that the SFR (or UV luminosity) of LBGs at z=3 shows no detectable dependence on environment over 2 orders of magnitude in density. To test the significance of our result, we use Monte Carlo simulations (from the mock catalogs) and the same projected density estimators we applied to our data. We find that we can reject the steep z=0 SFR-density at the 5-$\\sigma$ level. We conclude that the SFR-density at z=3 must be at least 3.6 times flatter than it is locally, i.e. the SFR of LBGs is significantly less dependent on environment than the SFR of local star-forming galaxies. We find that the rest-frame UV colors are also independent of environment.

Nicolas Bouche; James D. Lowenthal

2005-03-04T23:59:59.000Z

464

USING CUMULATIVE NUMBER DENSITIES TO COMPARE GALAXIES ACROSS COSMIC TIME  

SciTech Connect (OSTI)

Comparing galaxies across redshifts at fixed cumulative number density is a popular way to estimate the evolution of specific galaxy populations. This method ignores scatter in mass accretion histories and galaxy-galaxy mergers, which can lead to errors when comparing galaxies over large redshift ranges (?z > 1). We use abundance matching in the ?CDM paradigm to estimate the median change in cumulative number density with redshift and provide a simple fit (+0.16 dex per unit ?z) for progenitors of z = 0 galaxies. We find that galaxy descendants do not evolve in the same way as galaxy progenitors, largely due to scatter in mass accretion histories. We also provide estimates for the 1? range of cumulative number densities corresponding to galaxy progenitors and descendants. Finally, we discuss some limits on cumulative number density comparisons, which arise due to difficulties measuring physical quantities (e.g., stellar mass) consistently across redshifts. A public tool to calculate cumulative number density evolution for galaxies, as well as approximate halo masses, is available online.

Behroozi, Peter S.; Wechsler, Risa H. [Kavli Institute for Particle Astrophysics and Cosmology, SLAC National Accelerator Laboratory, Stanford, CA 94305 (United States)] [Kavli Institute for Particle Astrophysics and Cosmology, SLAC National Accelerator Laboratory, Stanford, CA 94305 (United States); Marchesini, Danilo [Department of Physics and Astronomy, Tufts University, Medford, MA 02155 (United States)] [Department of Physics and Astronomy, Tufts University, Medford, MA 02155 (United States); Muzzin, Adam [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden (Netherlands)] [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden (Netherlands); Papovich, Casey [Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States)] [Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States); Stefanon, Mauro [Physics and Astronomy Department, University of Missouri, Columbia, MO 65211 (United States)] [Physics and Astronomy Department, University of Missouri, Columbia, MO 65211 (United States)

2013-11-01T23:59:59.000Z

465

Dynamics of localized particles from density functional theory  

E-Print Network [OSTI]

A fundamental assumption of the dynamical density functional theory (DDFT) of colloidal systems is that a grand-canonical free energy functional may be employed to generate the thermodynamic driving forces. Using one-dimensional hard-rods as a model system we analyze the validity of this key assumption and show that unphysical self-interactions of the tagged particle density fields, arising from coupling to a particle reservoir, are responsible for the excessively fast relaxation predicted by the theory. Moreover, our findings suggest that even employing a canonical functional would not lead to an improvement for many-particle systems, if only the total density is considered. We present several possible schemes to suppress these effects by incorporating tagged densities. When applied to confined systems we demonstrate, using a simple example, that DDFT neccessarily leads to delocalized tagged particle density distributions, which do not respect the fundamental geometrical contraints apparent in Brownian dynamics simulation data. The implication of these results for possible applications of DDFT to treat the glass transition are discussed.

Johannes Reinhardt; Joseph Michael Brader

2011-11-23T23:59:59.000Z

466

Relativistic Nuclear Energy Density Functionals: adjusting parameters to binding energies  

E-Print Network [OSTI]

We study a particular class of relativistic nuclear energy density functionals in which only nucleon degrees of freedom are explicitly used in the construction of effective interaction terms. Short-distance (high-momentum) correlations, as well as intermediate and long-range dynamics, are encoded in the medium (nucleon density) dependence of the strength functionals of an effective interaction Lagrangian. Guided by the density dependence of microscopic nucleon self-energies in nuclear matter, a phenomenological ansatz for the density-dependent coupling functionals is accurately determined in self-consistent mean-field calculations of binding energies of a large set of axially deformed nuclei. The relationship between the nuclear matter volume, surface and symmetry energies, and the corresponding predictions for nuclear masses is analyzed in detail. The resulting best-fit parametrization of the nuclear energy density functional is further tested in calculations of properties of spherical and deformed medium-heavy and heavy nuclei, including binding energies, charge radii, deformation parameters, neutron skin thickness, and excitation energies of giant multipole resonances.

T. Niksic; D. Vretenar; P. Ring

2008-09-08T23:59:59.000Z

467

Pion transverse charge density and the edge of hadrons  

SciTech Connect (OSTI)

We use the world data on the pion form factor for space-like kinematics and a technique used to extract the proton transverse densities, to extract the transverse pion charge density and its uncertainty due to experimental uncertainties and incomplete knowledge of the pion form factor at large values of Q2. The pion charge density at small values of b<0.1 fm is dominated by this incompleteness error while the range between 0.1-0.3 fm is relatively well constrained. A comparison of pion and proton charge densities shows that the pion is denser than the proton for values of b<0.2 fm. The pion and proton distributions seem to be the same for values of b=0.2-0.6 fm. Future data from Jlab 12 GeV and the EIC will increase the dynamic extent of the data to higher values of Q2 and thus reduce the uncertainties in the extracted pion charge density.

Carmignotto, Marco [Catholic University of America; Horn, Tanja [Catholic University of America; Miller, Gerald A. [University of Washington

2014-08-01T23:59:59.000Z

468

Cosmic density and velocity fields in Lagrangian perturbation theory  

E-Print Network [OSTI]

A first- and second-order relation between cosmic density and peculiar-velocity fields is presented. The calculation is purely Lagrangian and it is derived using the second-order solutions of the Lagrange-Newton system obtained by Buchert & Ehlers. The procedure is applied to two particular solutions given generic initial conditions. In this approach, the continuity equation yields a relation between the over-density and peculiar-velocity fields that automatically satisfies Euler's equation because the orbits are derived from the Lagrange-Newton system. This scheme generalizes some results obtained by Nusser et al. (1991) in the context of the Zel'dovich approximation. As opposed to several other reconstruction schemes, in this approach it is not necessary to truncate the expansion of the Jacobian given by the continuity equation in order to calculate a first- or second-order expression for the density field. In these previous schemes, the density contrast given by (a) the continuity equation and (b) Euler's equation are mutually incompatible. This inconsistency arises as a consequence of an improper handling of Lagrangian and Eulerian coordinates in the analysis. Here, we take into account the fact that an exact calculation of the density is feasible in the Lagrangian picture and therefore an accurate and consistent description is obtained.

Mikel Susperregi; Thomas Buchert

1997-08-04T23:59:59.000Z

469

Gas Density and the Volume Schmidt Law for Spiral Galaxies  

E-Print Network [OSTI]

The thickness of the equilibrium isothermal gaseous layers and their volume densities \\rho_{gas}(R) in the disc midplane are calculated for 7 spiral galaxies (including our Galaxy) in the frame of self-consistent axisymmetric model. Local velocity dispersions of stellar discs were assumed to be close to marginal values necessary for the discs to be in a stable equilibrium state. Under this condition the stellar discs of at least 5 of 7 galaxies reveal a flaring. Their volume densities decrease with R faster than \\rho_{gas}, and, as a result, the gas dominates by the density at the disc periphery. Comparison of the azimuthally averaged star formation rate SFR with the gas density shows that there is no universal Schmidt law SFR \\rho_{gas}^n, common to all galaxies. Nevertheless, SFR in different galaxies reveals better correlation with the volume gas density than with the column one. Parameter n in the Schmidt law SFR \\rho_{gas}^n, formally calculated by the least square method, lies within 0.8-2.4 range and it's mean value is close to 1.5. Values of n calculated for molecular gas only are characterized by large dispersion, but their mean value is close to 1. Hence the smaller \\rho_{gas} the less is a fraction of gas actively taking part in the process of star formation.

O. V. Abramova; A. V. Zasov

2007-10-01T23:59:59.000Z

470

Phase-space explorations in time-dependent density functional theory A.K. Rajam a  

E-Print Network [OSTI]

Phase-space explorations in time-dependent density functional theory A.K. Rajam a , Paul Hessler b online xxxx Keywords: Time-dependent density functional theory Phase-space Momentum-distributions Density to phase-space densities, discuss some formal aspects of such a ``phase-space density functional theory

471

Design criteria for Si point-contact concentrator solar cells  

SciTech Connect (OSTI)

Design criteria for concentrator solar cells are presented for the highly three-dimensional case of backside point-contact solar cells. A recent new experimental result, a 28-percent efficient cell (25/sup 0/C, 15-Wcm/sup 2/ incident power) is used as a case study of the dependences of the recombination components and the carrier density gradients on the geometrical design parameters. The optimum geometry is found to depend upon the intended design power density as well as the attainable physical parameters allowed by the fabrication techniques utilized. Modeling projections indicate that an ultimate efficiency of 30.6 percent (36 Wcm/sup 2/, 300 K) is achievable using the diffused emitters presently employed on these cells. Incorporation of results from the study pf polycrystalline emitters could improve these efficiencies toward 31.7 percent.

Sinton, R.A.; Swanson, R.M.

1987-10-01T23:59:59.000Z

472

Out-of-equilibrium liquids that form due to dynamics of the molecules that depend on the local density  

E-Print Network [OSTI]

RNA molecules in living cells form what look like liquid droplets formed by liquid/liquid phase separation. But unlike the molecules in conventional phase separating mixtures, RNA molecules are transported by molecular motors that consume energy and so are out of equilibrium. Motivated by this we study models with out-of-equilibrium dynamics that depend on the local density. Our simulations suggest that density-dependent dynamics in which the motion of a molecule slows down in the presence of nearby molecules, tend to cause condensation into an out-of-equilibrium liquid state. This out-of-equilibrium state behaves like a liquid in the sense that it coexists with a much more dilute phase, droplets coalesce, and the state has a well-defined surface tension --- which we calculate. Liquid/liquid separation appears to be a very general phenomenon that occurs in and out of equilibrium. We also look at the analogous separation of the two blocks of a block copolymer, in which the monomers of one block have dynamics that depend on the local density of monomers of that block. We find that this block condenses and separates from the monomers of the other block. This is a simple model of the out-of-equilibrium domain formation found in the chromatin in the nucleus of cells.

Richard P. Sear

2015-03-24T23:59:59.000Z

473

Local thermodynamic equilibrium in rapidly heated high energy density plasmas  

SciTech Connect (OSTI)

Emission spectra and the dynamics of high energy density plasmas created by optical and Free Electron Lasers (FELs) depend on the populations of atomic levels. Calculations of plasma emission and ionization may be simplified by assuming Local Thermodynamic Equilibrium (LTE), where populations are given by the Saha-Boltzmann equation. LTE can be achieved at high densities when collisional processes are much more significant than radiative processes, but may not be valid if plasma conditions change rapidly. A collisional-radiative model has been used to calculate the times taken by carbon and iron plasmas to reach LTE at varying densities and heating rates. The effect of different energy deposition methods, as well as Ionization Potential Depression are explored. This work shows regimes in rapidly changing plasmas, such as those created by optical lasers and FELs, where the use of LTE is justified, because timescales for plasma changes are significantly longer than the times needed to achieve an LTE ionization balance.

Aslanyan, V.; Tallents, G. J. [York Plasma Institute, Department of Physics, University of York, Heslington, York YO10 5DD (United Kingdom)

2014-06-15T23:59:59.000Z

474

Cosmic Web Reconstruction through Density Ridges: Method and Algorithm  

E-Print Network [OSTI]

The detection and characterization of filamentary structures in the cosmic web allows cosmologists to constrain parameters that dictates the evolution of the Universe. While many filament estimators have been proposed, they generally lack estimates of uncertainty, reducing their inferential power. In this paper, we demonstrate how one may apply the Subspace Constrained Mean Shift (SCMS) algorithm (Ozertem and Erdogmus (2011); Genovese et al. (2012)) to uncover filamentary structure in galaxy data. The SCMS algorithm is a gradient ascent method that models filaments as density ridges, one-dimensional smooth curves that trace high-density regions within the point cloud. We also demonstrate how augmenting the SCMS algorithm with bootstrap-based methods of uncertainty estimation allows one to place uncertainty bands around putative filaments. We apply the SCMS method to datasets sampled from the P3M N-body simulation, with galaxy number densities consistent with SDSS and WFIRST-AFTA and to LOWZ and CMASS data fro...

Chen, Yen-Chi; Freeman, Peter E; Genovese, Christopher R; Wasserman, Larry

2015-01-01T23:59:59.000Z

475

Addressing spectroscopic quality of covariant density functional theory  

E-Print Network [OSTI]

The spectroscopic quality of covariant density functional theory has been accessed by analyzing the accuracy and theoretical uncertainties in the description of spectroscopic observables. Such analysis is first presented for the energies of the single-particle states in spherical and deformed nuclei. It is also shown that the inclusion of particle-vibration coupling improves the description of the energies of predominantly single-particle states in medium and heavy-mass spherical nuclei. However, the remaining differences between theory and experiment clearly indicate missing physics and missing terms in covariant energy density functionals. The uncertainties in the predictions of the position of two-neutron drip line sensitively depend on the uncertainties in the prediction of the energies of the single-particle states. On the other hand, many spectroscopic observables in well deformed nuclei at ground state and finite spin only weakly depend on the choice of covariant energy density functional.

A. V. Afanasjev

2014-09-17T23:59:59.000Z

476

Time-dependent current density functional theory on a lattice  

E-Print Network [OSTI]

A rigorous formulation of time-dependent current density functional theory (TDCDFT) on a lattice is presented. The density-to-potential mapping and the ${\\cal V}$-representability problems are reduced to a solution of a certain nonlinear lattice Schr\\"odinger equation, to which the standard existence and uniqueness results for nonliner differential equations are applicable. For two versions of the lattice TDCDFT we prove that any continuous in time current density is locally ${\\cal V}$-representable (both interacting and noninteracting), provided in the initial state the local kinetic energy is nonzero everywhere. In most cases of physical interest the ${\\cal V}$-representability should also hold globally in time. These results put the application of TDCDFT to any lattice model on a firm ground, and open a way for studying exact properties of exchange correlation potentials.

I. V. Tokatly

2010-11-11T23:59:59.000Z

477

Density waves in the shearing sheet III. Disc heating  

E-Print Network [OSTI]

The problem of dynamical heating of galactic discs by spiral density waves is discussed using the shearing sheet model. The secular evolution of the disc is described quantitatively by a diffusion equation for the distribution function of stars in the space spanned by integrals of motion of the stars, in particular the radial action integral and an integral related to the angular momentum. Specifically, disc heating by a succession of transient, `swing amplified' density waves is studied. It is shown that such density waves lead predominantly to diffusion of stars in radial action space. The stochastical changes of angular momenta of the stars and the corresponding stochastic changes of the guiding centre radii of the stellar orbits induced by this process are much smaller.

B. Fuchs

2001-04-25T23:59:59.000Z

478

Relativistic density functional theory for finite nuclei and neutron stars  

E-Print Network [OSTI]

The main goal of the present contribution is a pedagogical introduction to the fascinating world of neutron stars by relying on relativistic density functional theory. Density functional theory provides a powerful--and perhaps unique--framework for the calculation of both the properties of finite nuclei and neutron stars. Given the enormous densities that may be reached in the core of neutron stars, it is essential that such theoretical framework incorporates from the outset the basic principles of Lorentz covariance and special relativity. After a brief historical perspective, we present the necessary details required to compute the equation of state of dense, neutron-rich matter. As the equation of state is all that is needed to compute the structure of neutron stars, we discuss how nuclear physics--particularly certain kind of laboratory experiments--can provide significant constrains on the behavior of neutron-rich matter.

Piekarewicz, J

2015-01-01T23:59:59.000Z

479

Ducted kinetic Alfven waves in plasma with steep density gradients  

SciTech Connect (OSTI)

Given their high plasma density (n {approx} 10{sup 13} cm{sup -3}), it is theoretically possible to excite Alfven waves in a conventional, moderate length (L {approx} 2 m) helicon plasma source. However, helicon plasmas are decidedly inhomogeneous, having a steep radial density gradient, and typically have a significant background neutral pressure. The inhomogeneity introduces regions of kinetic and inertial Alfven wave propagation. Ion-neutral and electron-neutral collisions alter the Alfven wave dispersion characteristics. Here, we present the measurements of propagating kinetic Alfven waves in helium helicon plasma. The measured wave dispersion is well fit with a kinetic model that includes the effects of ion-neutral damping and that assumes the high density plasma core defines the radial extent of the wave propagation region. The measured wave amplitude versus plasma radius is consistent with the pile up of wave magnetic energy at the boundary between the kinetic and inertial regime regions.

Houshmandyar, Saeid [Solar Observatory Department, Prairie View A and M University, Prairie View, Texas 77446 (United States); Department of Physics, West Virginia University, Morgantown, West Virginia 26506-6315 (United States); Scime, Earl E. [Department of Physics, West Virginia University, Morgantown, West Virginia 26506-6315 (United States)

2011-11-15T23:59:59.000Z

480

Transverse charge and magnetization densities in the nucleon's chiral periphery  

SciTech Connect (OSTI)

In the light-front description of nucleon structure the electromagnetic form factors are expressed in terms of frame-independent transverse densities of charge and magnetization. Recent work has studied the transverse densities at peripheral distances b = O(M{pi}{sup -1}), where they are governed by universal chiral dynamics and can be computed in a model-independent manner. Of particular interest is the comparison of the peripheral charge and magnetization densities. We summarize (a) their interpretation as spin-independent and -dependent current matrix elements; (b) the leading-order chiral effective field theory results; (c) their mechanical interpretation in the light-front formulation; (d) the large-N_c limit of QCD and the role of {Delta} intermediate states; (e) the connection with generalized parton distributions and peripheral high-energy scattering processes.

Granados, Carlos G. [JLAB Newport News, VA (United States); Weiss, Christian [JLAB Newport News, VA (United States)

2014-01-01T23:59:59.000Z

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481

Exploration of Plasma Jets Approach to High Energy Density Physics  

SciTech Connect (OSTI)

High-energy-density laboratory plasma (HEDLP) physics is an emerging, important area of research in plasma physics, nuclear physics, astrophysics, and particle acceleration. While the HEDLP regime occurs at extreme conditions which are often found naturally in space but not on the earth, it may be accessible by colliding high intensity plasmas such as high-energy-density plasma jets, plasmoids or compact toroids from plasma guns. The physics of plasma jets is investigated in the context of high energy density laboratory plasma research. This report summarizes results of theoretical and computational investigation of a plasma jet undergoing adiabatic compression and adiabatic expansion. A root-mean-squared (rms) envelope theory of plasma jets is developed. Comparison between theory and experiment is made. Good agreement between theory and experiment is found.

Chen, Chiping [Massachusetts Institute of Technology

2013-08-26T23:59:59.000Z

482

Ultra-low density InAs quantum dots  

SciTech Connect (OSTI)

We show that InAs quantum dots (QDs) can be grown by molecular beam epitaxy (MBE) with an ultralow density of sin 10{sup 7} cm{sup -2} without any preliminary or post-growth surface treatment. The strain-induced QD formation proceeds via the standard Stranski-Krastanow mechanism, where the InAs coverage is decreased to 1.3-1.5 monolayers (MLs). By using off-cut GaAs (100) substrates, we facilitate the island nucleation in this subcritical coverage range without any growth interruption. The QD density dependences on the InAs coverage are studied by photoluminescence, atomic force microscopy, transmission electron microscopy, and are well reproduced by the universal double exponential shapes. This method enables the fabrication of InAs QDs with controllable density in the range 10{sup 7}-10{sup 8} cm{sup -2}, exhibiting bright photoluminescence.

Dubrovskii, V. G., E-mail: dubrovskii@mail.ioffe.ru; Cirlin, G. E. [St. Petersburg Academic University Russian Academy of Sciences (Russian Federation)] [St. Petersburg Academic University Russian Academy of Sciences (Russian Federation); Brunkov, P. A. [Ioffe Physical Technical Institute Russian Academy of Sciences (Russian Federation)] [Ioffe Physical Technical Institute Russian Academy of Sciences (Russian Federation); Perimetti, U.; Akopyan, N. [Delft University of Technology, Quantum Transport, Kavli Institute of Nanoscience (Netherlands)] [Delft University of Technology, Quantum Transport, Kavli Institute of Nanoscience (Netherlands)

2013-10-15T23:59:59.000Z

483

Linear response of homogeneous nuclear matter with energy density functionals  

E-Print Network [OSTI]

Response functions of infinite nuclear matter with arbitrary isospin asymmetry are studied in the framework of the random phase approximation. The residual interaction is derived from a general nuclear Skyrme energy density functional. Besides the usual central, spin-orbit and tensor terms it could also include other components as new density-dependent terms or three-body terms. Algebraic expressions for the response functions are obtained from the Bethe-Salpeter equation for the particle-hole propagator. Applications to symmetric nuclear matter, pure neutron matter and asymmetric nuclear matter are presented and discussed. Spin-isospin strength functions are analyzed for varying conditions of density, momentum transfer, isospin asymmetry, and temperature for some representative Skyrme functionals. Particular attention is paid to the discussion of instabilities, either real or unphysical, which could manifest in finite nuclei.

A. Pastore; D. Davesne; J. Navarro

2014-12-07T23:59:59.000Z

484

PEM fuel cells for transportation and stationary power generation applications  

SciTech Connect (OSTI)

We describe recent activities at LANL devoted to polymer electrolyte fuel cells in the contexts of stationary power generation and transportation applications. A low cost/high performance hydrogen or reformate/air stack technology is being developed based on ultralow Pt loadings and on non-machined, inexpensive elements for flow-fields and bipolar plates. On board methanol reforming is compared to the option of direct methanol fuel cells because of recent significant power density increases demonstrated in the latter.

Cleghorn, S.J.; Ren, X.; Springer, T.E.; Wilson, M.S.; Zawodzinski, C.; Zawodzinski, T.A. Jr.; Gottesfeld, S.

1996-05-01T23:59:59.000Z

485

Energy density functional for nuclei and neutron stars  

E-Print Network [OSTI]

We aim to develop a nuclear energy density functional that can be simultaneously applied to finite nuclei and neutron stars. We use the self-consistent nuclear density functional theory (DFT) with Skyrme energy density functionals and covariance analysis to assess correlations between observables for finite nuclei and neutron stars. In a first step two energy functionals -- a high density energy functional giving reasonable neutron properties, and a low density functional fitted to nuclear properties -- are matched. In a second step, we optimize a new functional using exactly the same protocol as in earlier studies pertaining to nuclei but now including neutron star data. This allows direct comparisons of performance of the new functional relative to the standard one. The new functional TOV-min yields results for nuclear bulk properties (energy, r.m.s. radius, diffraction radius, surface thickness) that are of the same quality as those obtained with the established Skyrme functionals, including SV-min. When comparing SV-min and TOV-min, isoscalar nuclear matter indicators vary slightly while isovector properties are changed considerably. We discuss neutron skins, dipole polarizability, separation energies of the heaviest elements, and proton and neutron drip lines. We confirm a correlation between the neutron skin of $^{208}$Pb and the neutron star radius. We demonstrate that standard energy density functionals optimized to nuclear data do not carry information on the expected maximum neutron star mass, and that predictions can only be made within an extremely broad uncertainty band. For atomic nuclei, the new functional TOV-min performs at least as well as the standard nuclear functionals, but it also reproduces expected neutron star data within assumed error bands.

J. Erler; C. J. Horowitz; W. Nazarewicz; M. Rafalski; P. -G. Reinhard

2012-11-27T23:59:59.000Z

486

High-density turbidity currents: Are they sandy debris flows?  

SciTech Connect (OSTI)

Conventionally, turbidity currents are considered as fluidal flows in which sediment is supported by fluid turbulence, whereas debris flows are plastic flows in which sediment is supported by matrix strength, dispersive pressure, and buoyant lift. The concept of high-density turbidity current refers to high-concentration, commonly non-turbulent, flows of fluids in which sediment is supported mainly by matrix strength, dispersive pressure, and buoyant lift. The conventional wisdom that traction carpets with entrained turbulent clouds on top represent high-density turbidity currents is a misnomer because traction carpets are neither fluidal nor turbulent. Debris flows may also have entrained turbulent clouds on top. The traction carpet/debris flow and the overriding turbulent clouds are two separate entities in terms of flow rheology and sediment-support mechanism. In experimental and theoretical studies, which has linked massive sands and floating clasts to high-density turbidity currents, the term high-density turbidity current has actually been used for laminar flows. In alleviating this conceptual problem, sandy debris flow is suggested as a substitute for high-density turbidity current. Sandy debris flows represent a continuous spectrum of processes between cohesive and cohesionless debris flows. Commonly they are rheologically plastic. They may occur with or without entrained turbulent clouds on top. Their sediment-support mechanisms include matrix strength, dispersive pressure, and buoyant lift. They are characterized by laminar flow conditions, a moderate to high grain concentration, and a low to moderate mud content. Although flows evolve and transform during the course of transport in density-stratified flows, the preserved features in a deposit are useful to decipher only the final stages of deposition. At present, there are no established criteria to decipher transport mechanism from the depositional record.

Shanmugam, G. [Mobil Exploration and Producing Technical Center, Dallas, TX (United States)

1996-01-01T23:59:59.000Z

487

Energy Density Functional for Nuclei and Neutron Stars  

SciTech Connect (OSTI)

Background: Recent observational data on neutron star masses and radii provide stringent constraints on the equation of state of neutron rich matter [ Annu. Rev. Nucl. Part. Sci. 62 485 (2012)]. Purpose: We aim to develop a nuclear energy density functional that can be simultaneously applied to finite nuclei and neutron stars. Methods: We use the self-consistent nuclear density functional theory (DFT) with Skyrme energy density functionals and covariance analysis to assess correlations between observables for finite nuclei and neutron stars. In a first step two energy functionals a high density energy functional giving reasonable neutron properties, and a low density functional fitted to nuclear properties are matched. In a second step, we optimize a new functional using exactly the same protocol as in earlier studies pertaining to nuclei but now including neutron star data. This allows direct comparisons of performance of the new functional relative to the standard one. Results: The new functional TOV-min yields results for nuclear bulk properties (energy, rms radius, diffraction radius, and surface thickness) that are of the same quality as those obtained with the established Skyrme functionals, including SV-min. When comparing SV-min and TOV-min, isoscalar nuclear matter indicators vary slightly while isovector properties are changed considerably. We discuss neutron skins, dipole polarizability, separation energies of the heaviest elements, and proton and neutron drip lines. We confirm a correlation between the neutron skin of 208Pb and the neutron star radius. Conclusions: We demonstrate that standard energy density functionals optimized to nuclear data do not carry information on the expected maximum neutron star mass, and that predictions can only be made within an extremely broad uncertainty band. For atomic nuclei, the new functional TOV-min performs at least as well as the standard nuclear functionals, but it also reproduces expected neutron star data within assumed error bands. This functional is expected to yield more reliable predictions in the region of very neutron rich heavy nuclei.

Erler, J. [UTK/ORNL/German Cancer Research Center-Heidelberg; Horowitz, C. J. [UTK/ORNL/Indiana University; Nazarewicz, Witold [UTK/ORNL/University of Warsaw; Rafalski, M. [UTK/ORNL; Reinhard, P.-G. [Universitat Erlangen, Germany

2013-01-01T23:59:59.000Z

488

The volume densities of GMCs in M81  

E-Print Network [OSTI]

HI features near young star clusters in M81 are identified as the photodissociated surfaces of Giant Molecular Clouds (GMCs) from which the young stars have recently formed. The HI column densities of these features show a weak trend, from undetectable values inside R = 3.7 kpc and increasing rapidly to values around 3 x 10^21 cm^-2 near R ~ 7.5 kpc. This trend is similar to that of the radially-averaged HI distribution in this galaxy, and implies a constant area covering factor of ~ 0.21 for GMCs throughout M81. The incident UV fluxes G0 of our sample of candidate PDRs decrease radially. A simple equilibrium model of the photodissociation-reformation process connects the observed values of the incident UV flux, the HI column density, and the relative dust content, permitting an independent estimate to be made of the total gas density in the GMC. Within the GMC this gas will be predominantly molecular hydrogen. Volume densities of 1 < n < 200 cm^-3 are derived, with a geometric mean of 17 cm^-3. These values are similar to the densities of GMCs in the Galaxy, but somewhat lower than those found earlier for M101 with similar methods. Low values of molecular density in the GMCs of M81 will result in low levels of collisional excitation of the CO(1-0) transition, and are consistent with the very low surface brightness of CO(1-0) emission observed in the disk of M81.

Jonathan S. Heiner; Ronald J. Allen; Bjorn H. C. Emonts; Pieter C. van der Kruit

2007-10-05T23:59:59.000Z

489

Radiating Gravitational Collapse with an Initial Inhomogeneous Energy Density Distribution  

E-Print Network [OSTI]

A new model is proposed to a collapsing star consisting of an initial inhomogeneous energy density and anisotropic pressure fluid with shear, radial heat flow and outgoing radiation. In previous papers one of us has always assumed an initial star with homogeneous energy density. The aim of this work is to generalize the previous models by introducing an initial inhomogeneous energy density and compare it to the initial homogeneous energy density collapse model. We will show the differences between these models in the evolution of all physical quantities that characterizes the gravitational collapse. The behavior of the energy density, pressure, mass, luminosity and the effective adiabatic index is analyzed. The pressure of the star, at the beginning of the collapse, is isotropic but due to the presence of the shear the pressure becomes more and more anisotropic. The black hole is never formed because the apparent horizon formation condition is never satisfied, in contrast of the previous model where a black hole is formed. An observer at infinity sees a radial point source radiating exponentially until reaches the time of maximum luminosity and suddenly the star turns off. In contrast of the former model where the luminosity also increases exponentially, reaching a maximum and after it decreases until the formation of the black hole. The effective adiabatic index is always positive without any discontinuity in contrast of the former model where there is a discontinuity around the time of maximum luminosity. The collapse is about three thousand times slower than in the case where the energy density is initially homogeneous.

G. Pinheiro; R. Chan

2014-06-01T23:59:59.000Z

490

Semi-exact concentric atomic density fitting: Reduced cost and increased accuracy compared to standard density fitting  

SciTech Connect (OSTI)

A local density fitting scheme is considered in which atomic orbital (AO) products are approximated using only auxiliary AOs located on one of the nuclei in that product. The possibility of variational collapse to an unphysical “attractive electron” state that can affect such density fitting [P. Merlot, T. Kjærgaard, T. Helgaker, R. Lindh, F. Aquilante, S. Reine, and T. B. Pedersen, J. Comput. Chem. 34, 1486 (2013)] is alleviated by including atom-wise semidiagonal integrals exactly. Our approach leads to a significant decrease in the computational cost of density fitting for Hartree–Fock theory while still producing results with errors 2–5 times smaller than standard, nonlocal density fitting. Our method allows for large Hartree–Fock and density functional theory computations with exact exchange to be carried out efficiently on large molecules, which we demonstrate by benchmarking our method on 200 of the most widely used prescription drug molecules. Our new fitting scheme leads to smooth and artifact-free potential energy surfaces and the possibility of relatively simple analytic gradients.

Hollman, David S. [Center for Computational Quantum Chemistry, University of Georgia, 1004 Cedar St., Athens, Georgia 30602 (United States) [Center for Computational Quantum Chemistry, University of Georgia, 1004 Cedar St., Athens, Georgia 30602 (United States); Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061 (United States); Schaefer, Henry F. [Center for Computational Quantum Chemistry, University of Georgia, 1004 Cedar St., Athens, Georgia 30602 (United States)] [Center for Computational Quantum Chemistry, University of Georgia, 1004 Cedar St., Athens, Georgia 30602 (United States); Valeev, Edward F. [Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061 (United States)] [Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061 (United States)

2014-02-14T23:59:59.000Z

491

Optical Emission Spectroscopic Techniques for Low Electron Density Diagnostics  

SciTech Connect (OSTI)

This paper comprises an analysis of optical emission spectroscopy (OES) techniques and results of their application for diagnostics of middle and low electron densities in low temperature plasmas. The following OES diagnostic techniques based on: 1) line merging along spectral line series, 2) use of line shapes and Stark halfwidths of hydrogen Balmer lines, 3) line shape of helium lines with forbidden components and 4) use of molecular nitrogen bandhead intensities are studied, discussed, tested and applied and in some cases ugraded for electron density measurements. The overall comparative analysis is performed also.

Ivkovic, M. [Institute of Physics, 11081 Belgrade, P.O.Box 68 (Serbia and Montenegro)

2006-12-01T23:59:59.000Z

492

High density electronic circuit and process for making  

DOE Patents [OSTI]

High density circuits with posts that protrude beyond one surface of a substrate to provide easy mounting of devices such as integrated circuits. The posts also provide stress relief to accommodate differential thermal expansion. The process allows high interconnect density with fewer alignment restrictions and less wasted circuit area than previous processes. The resulting substrates can be test platforms for die testing and for multi-chip module substrate testing. The test platform can contain active components and emulate realistic operational conditions, replacing shorts/opens net testing.

Morgan, William P. (Albuquerque, NM)

1999-01-01T23:59:59.000Z

493

High density electronic circuit and process for making  

DOE Patents [OSTI]

High density circuits with posts that protrude beyond one surface of a substrate to provide easy mounting of devices such as integrated circuits are disclosed. The posts also provide stress relief to accommodate differential thermal expansion. The process allows high interconnect density with fewer alignment restrictions and less wasted circuit area than previous processes. The resulting substrates can be test platforms for die testing and for multi-chip module substrate testing. The test platform can contain active components and emulate realistic operational conditions, replacing shorts/opens net testing. 8 figs.

Morgan, W.P.

1999-06-29T23:59:59.000Z

494

Density functional theory and optimal transportation with Coulomb cost  

E-Print Network [OSTI]

We present here novel insight into exchange-correlation functionals in density functional theory, based on the viewpoint of optimal transport. We show that in the case of two electrons and in the semiclassical limit, the exact exchange-correlation functional reduces to a very interesting functional of novel form, which depends on an optimal transport map $T$ associated with a given density $\\rho$. Since the above limit is strongly correlated, the limit functional yields insight into electron correlations. We prove the existence and uniqueness of such an optimal map for any number of electrons and each $\\rho$, and determine the map explicitly in the case when $\\rho$ is radially symmetric.

Codina Cotar; Gero Friesecke; Claudia Klüppelberg

2011-04-04T23:59:59.000Z

495

Statistical hadronization model description for rapidity densities at RHIC  

E-Print Network [OSTI]

The rapidity densities in Au-Au collisions at center-of-mass energies 200 and 130 A GeV measured at Relativistic Heavy-Ion Collider by STAR and PHENIX collaborations are analyzed within the statistical hadronization model at chemical freeze-out. We find that the model can describe the experimental rapidity densities well. The corresponding chemical freeze-out parameters are determined and they are seen to be in agreement with what we expect from our previous analyzes at lower beam energies at AGS and SPS.

Jaakko Manninen

2007-03-14T23:59:59.000Z

496

A Model for the Density Distribution of Virialized CDM Halos  

E-Print Network [OSTI]

An analytic collapse model for the formation and density distribution of virialized cold dark matter halos is proposed. Hierarchical structure formation is taken into account explicitly. Monte Carlo methods are used to generate samples of mass histories of virialized halos. The mean density distribution found from the collapse model is in good agreement with numerical results in the mass range from $10^{11}M_\\odot$ to $10^{15}M_\\odot$ and in the radial range form $0.05 r_{200}$ to $r_{200}$.

A. Kull

1999-02-20T23:59:59.000Z

497

Secondary dust density waves excited by nonlinear dust acoustic waves  

SciTech Connect (OSTI)

Secondary dust density waves were observed in conjunction with high amplitude (n{sub d}/n{sub d0}>2) dust acoustic waves (DAW) that were spontaneously excited in a dc glow discharge dusty plasma in the moderately coupled, {Gamma}{approx}1, state. The high amplitude dust acoustic waves produced large dust particle oscillations, displacements, and trapping. Secondary dust density waves were excited in the wave troughs of the high amplitude DAWs. The waveforms, amplitudes, wavelengths, and wave speeds of the primary DAWs and the secondary waves were measured. A dust-dust streaming instability is discussed as a possible mechanism for the production of the secondary waves.

Heinrich, J. R.; Kim, S.-H.; Meyer, J. K.; Merlino, R. L. [Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242 (United States); Rosenberg, M. [Department of Electrical and Computer Engineering, University of California, San Diego, California 92093 (United States)

2012-08-15T23:59:59.000Z

498

Temperature and density extrapolations in canonical ensemble Monte Carlo simulations  

E-Print Network [OSTI]

We show how to use the multiple histogram method to combine canonical ensemble Monte Carlo simulations made at different temperatures and densities. The method can be applied to study systems of particles with arbitrary interaction potential and to compute the thermodynamic properties over a range of temperatures and densities. The calculation of the Helmholtz free energy relative to some thermodynamic reference state enables us to study phase coexistence properties. We test the method on the Lennard-Jones fluids for which many results are available.

A. L. Ferreira; M. A. Barroso

1999-06-14T23:59:59.000Z

499

Metal-insulator Transition by Holographic Charge Density Waves  

E-Print Network [OSTI]

We construct a gravity dual for charge density waves (CDW) in which the translational symmetry along one spatial direction is spontaneously broken. Our linear perturbation calculation on the gravity side produces the frequency dependence of the optical conductivity, which exhibits the two familiar features of charge density waves, namely the pinned collective mode and gapped single-particle excitation. These two features indicate that our gravity dual also provides a new mechanism to implement the metal to insulator phase transition by CDW, which is further supported by the fact that d.c. conductivity decreases with the decreased temperature below the critical temperature.

Yi Ling; Chao Niu; Jianpin Wu; Zhuoyu Xian; Hongbao Zhang

2014-08-06T23:59:59.000Z

500

Photoelectrochemical cell  

DOE Patents [OSTI]

A photoelectrochemical cell comprising a sealed container having a light-transmitting window for admitting light into the container across a light-admitting plane, an electrolyte in the container, a photoelectrode in the container having a light-absorbing surface arranged to receive light from the window and in contact with the electrolyte, the surface having a plurality of spaced portions oblique to the plane, each portion having dimensions at least an order of magnitude larger than the maximum wavelength of incident sunlight, the total surface area of the surface being larger than the area of the plane bounded by the container, and a counter electrode in the container in contact with the electrolyte.

Rauh, R. David (Newton, MA); Boudreau, Robert A. (Norton, MA)

1983-06-14T23:59:59.000Z