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Note: This page contains sample records for the topic "melting includes graphite" 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.


1

A first order two-dimensional melting transition : methane adsorbed on (0001) graphite (*)  

E-Print Network [OSTI]

L-543 A first order two-dimensional melting transition : methane adsorbed on (0001) graphite (*) A. Abstract. 2014 The variation of long range order of a registered solid submonolayer of methane adsorbed for various solid mono- layers adsorbed on graphite indicates that solid- fluid phase transitions are more

Paris-Sud XI, Université de

2

Development of a plasma coating system for induction melting zirconium in a graphite crucible  

SciTech Connect (OSTI)

A plasma coating system has been developed for induction melting zirconium at 1900 C using a graphite crucible. This laminated coating system consists of plasma spraying the following materials onto the graphite: (1) molybdenum or tungsten, (2) a 50% blend by weight of the metal powder and calcia-stabilized zirconium oxide, and (3) calcia-stabilized zirconia followed by painting a final coating of nonstabilized zirconia on top of the plasma-sprayed coating system. Zirconium was melted in argon using both laminating systems without any degradation of the graphite crucible and with only a minimal amount of carbon absorption. This novel approach that is being proposed as an alternative method of melting zirconium alloys offers substantial cost savings over the standard practice of electric arc melting using a consumable electrode.

Bird, E.L.; Holcombe, C.E. Jr.

1993-05-26T23:59:59.000Z

3

Structural graphitic carbon foams  

SciTech Connect (OSTI)

Graphitic carbon foams are a unique material form with very high structural and thermal properties at a light weight. A process has been developed to produce microcellular, open-celled graphitic foams. The process includes heating a mesophase pitch preform above the pitch melting temperature in a pressurized reactor. At the appropriate time, the pressure is released, the gas nucleates bubbles, and these bubbles grow forming the pitch into the foam structure. The resultant foamed pitch is then stabilized in an oxygen environment. At this point a rigid structure exists with some mechanical integrity. The foam is then carbonized to 800 C followed by a graphitization to 2700 C. The shear action from the growing bubbles aligns the graphitic planes along the foam struts to provide the ideal structure for good mechanical properties. Some of these properties have been characterized for some of the foam materials. It is known that variations of the blowing temperature, blowing pressure and saturation time result in foams of variously sized with mostly open pores; however, the mechanism of bubble nucleation is not known. Therefore foams were blown with various gases to begin to determine the nucleation method. These gases are comprised of a variety of molecular weights as well as a range of various solubility levels. By examining the resultant structures of the foam, differences were noted to develop an explanation of the foaming mechanism.

Kearns, K.M.; Anderson, H.J. [Air Force Lab., Wright-Patterson AFB, OH (United States). Materials and Mfg. Directorate

1998-12-31T23:59:59.000Z

4

Chapter 20: Graphite  

SciTech Connect (OSTI)

Graphite is truly a unique material. Its structure, from the nano- to the millimeter scale give it remarkable properties that lead to numerous and diverse applications. Graphite bond anisotropy, with strong in-plane covalent bonds and weak van der Waals type bonding between the planes, gives graphite its unique combination of properties. Easy shear of the crystal, facilitated by weak interplaner bonds allows graphite to be used as a dry lubricant, and is responsible for the substances name! The word graphite is derived from the Greek to write because of graphites ability to mark writing surfaces. Moreover, synthetic graphite contains within its structure, porosity spanning many orders of magnitude in size. The thermal closure of these pores profoundly affects the properties for example, graphite strength increases with temperature to temperatures in excess of 2200 C. Consequently, graphite is utilized in many high temperature applications. The basic physical properties of graphite are reviewed here. Graphite applications include metallurgical; (aluminum and steel production), single crystal silicon production, and metal casting; electrical (motor brushes and commutators); mechanical (seals, bearings and bushings); and nuclear applications, (see Chapter 91, Nuclear Graphite). Here we discuss the structure, manufacture, properties, and applications of Graphite.

Burchell, Timothy D [ORNL

2012-01-01T23:59:59.000Z

5

Preparation and thermal properties of expanded graphite/paraffin/organic montmorillonite composite phase change material  

Science Journals Connector (OSTI)

Expanded graphite (EG)/paraffin/organic montmorillonite (OMMT) composite phase change material (PCM) was prepared by using melt...

Hongtao Kao; Min Li; Xuewen Lv; Jinmiao Tan

2012-01-01T23:59:59.000Z

6

Graphite-based photovoltaic cells  

DOE Patents [OSTI]

The present invention uses lithographically patterned graphite stacks as the basic building elements of an efficient and economical photovoltaic cell. The basic design of the graphite-based photovoltaic cells includes a plurality of spatially separated graphite stacks, each comprising a plurality of vertically stacked, semiconducting graphene sheets (carbon nanoribbons) bridging electrically conductive contacts.

Lagally, Max (Madison, WI); Liu, Feng (Salt Lake City, UT)

2010-12-28T23:59:59.000Z

7

Coated graphite articles useful in metallurgical processes and method for making same  

DOE Patents [OSTI]

Graphite articles including crucibles and molds used in metallurgical processes involving the melting and the handling of molten metals and alloys that are reactive with carbon when in a molten state and at process temperatures up to about 2000.degree. C. are provided with a multiple-layer coating for inhibiting carbon diffusion from the graphite into the molten metal or alloys. The coating is provided by a first coating increment of a carbide-forming metal on selected surfaces of the graphite, a second coating increment of a carbide forming metal and a refractory metal oxide, and a third coating increment of a refractory metal oxide. The second coating increment provides thermal shock absorbing characteristics to prevent delamination of the coating during temperature cycling. A wash coat of unstabilized zirconia or titanium nitride can be applied onto the third coating increment to facilitate release of melts from the coating.

Holcombe, Cressie E. (Knoxville, TN); Bird, Eugene L. (Knoxville, TN)

1995-01-01T23:59:59.000Z

8

Do Ag{sub n} (up to n = 8) clusters retain their identity on graphite? Insights from first-principles calculations including dispersion interactions  

SciTech Connect (OSTI)

Adsorption of pre-formed Ag{sub n} clusters for n = 1 ? 8 on a graphite substrate is studied within the density functional theory employing the vdW-DF2 functional to treat dispersion interactions. Top sites above surface layer carbon atoms turn out to be most favorable for a Ag adatom, in agreement with experimental observations. The same feature is observed for clusters of almost all sizes which have the lowest energies when the Ag atoms are positioned over top sites. Most gas phase isomers retain their structures over the substrate, though a couple of them undergo significant distortions. Energetics of the adsorption can be understood in terms of a competition between energy cost of disturbing Ag–Ag bonds in the cluster and energy gain from Ag–C interactions at the surface. Ag{sub 3} turns out to be an exceptional candidate in this regard that undergoes significant structural distortion and has only two of the Ag atoms close to surface C atoms in its lowest energy structure.

Singh, Akansha; Sen, Prasenjit, E-mail: prasen@hri.res.in [Harish-Chandra Research Institute, Chhatnag Road, Jhunsi, Allahabad 211019 (India)] [Harish-Chandra Research Institute, Chhatnag Road, Jhunsi, Allahabad 211019 (India); Majumder, Chiranjib [Chemistry Division, Bhabha Atomic Research Center, Trombay, Mumbai 400085 (India)] [Chemistry Division, Bhabha Atomic Research Center, Trombay, Mumbai 400085 (India)

2014-04-28T23:59:59.000Z

9

Graphitized needle cokes and natural graphites for lithium intercalation  

SciTech Connect (OSTI)

This paper examined effects of heat treatment and milling (before or after heat treatment) on the (electrochemical) intercalating ability of needle petroleum coke; natural graphite particles are included for comparison. 1 tab, 4 figs, 7 refs.

Tran, T.D.; Spellman, L.M.; Pekala, R.W. [Lawrence Livermore National Lab., CA (United States); Goldberger, W.M. [Superior Graphite Co., Chicago, IL (United States); Kinoshita, K. [Lawrence Berkeley National Lab., CA (United States)

1996-05-10T23:59:59.000Z

10

Melt containment member  

DOE Patents [OSTI]

A tubular melt containment member for transient containment of molten metals and alloys, especially reactive metals and alloys, includes a melt-contacting layer or region that comprises an oxygen-deficient rare earth oxide material that is less reactive as compared to the counterpart stoichiometric rare earth oxide. The oxygen-deficient (sub-stoichiometric) rare earth oxide can comprise oxygen-deficient yttria represented by Y.sub.2O.sub.3-x wherein x is from 0.01 to 0.1. Use of the oxygen-deficient rare earth oxide as the melt-contacting layer or region material reduces reaction with the melt for a given melt temperature and melt contact time.

Rieken, Joel R.; Heidloff, Andrew J.

2014-09-09T23:59:59.000Z

11

Melting of iron-aluminide alloys  

SciTech Connect (OSTI)

The melting of Fe{sub 3}Al-based alloys at the Oak Ridge National Laboratory (ORNL) and commercial vendors is described. The melting processes evaluated includes are melting, air-induction melting (AIM), vacuum-induction melting (VIM), and electroslag remelting (ESR). The quality of the ingots studied are base on internal soundness and the surface finish obtained. The ingots were analyzed for recovery of various elements during melting. The impurity levels observed in the alloys by various melting processes were compared. Recommendations are made for viable processes for commercial melting of these alloys. 1 ref., 5 figs., 3 tabs.

Sikka, V.K.

1990-01-01T23:59:59.000Z

12

Modeling Fission Product Sorption in Graphite Structures  

SciTech Connect (OSTI)

The goal of this project is to determine changes in adsorption and desorption of fission products to/from nuclear-grade graphite in response to a changing chemical environment. First, the project team will employ principle calculations and thermodynamic analysis to predict stability of fission products on graphite in the presence of structural defects commonly observed in very high- temperature reactor (VHTR) graphites. Desorption rates will be determined as a function of partial pressure of oxygen and iodine, relative humidity, and temperature. They will then carry out experimental characterization to determine the statistical distribution of structural features. This structural information will yield distributions of binding sites to be used as an input for a sorption model. Sorption isotherms calculated under this project will contribute to understanding of the physical bases of the source terms that are used in higher-level codes that model fission product transport and retention in graphite. The project will include the following tasks: Perform structural characterization of the VHTR graphite to determine crystallographic phases, defect structures and their distribution, volume fraction of coke, and amount of sp2 versus sp3 bonding. This information will be used as guidance for ab initio modeling and as input for sorptivity models; Perform ab initio calculations of binding energies to determine stability of fission products on the different sorption sites present in nuclear graphite microstructures. The project will use density functional theory (DFT) methods to calculate binding energies in vacuum and in oxidizing environments. The team will also calculate stability of iodine complexes with fission products on graphite sorption sites; Model graphite sorption isotherms to quantify concentration of fission products in graphite. The binding energies will be combined with a Langmuir isotherm statistical model to predict the sorbed concentration of fission products on each type of graphite site. The model will include multiple simultaneous adsorbing species, which will allow for competitive adsorption effects between different fission product species and O and OH (for modeling accident conditions).

Szlufarska, Izabela [University of Wisconsin, Madison, WI (United States); Morgan, Dane [University of Wisconsin, Madison, WI (United States); Allen, Todd [University of Wisconsin, Madison, WI (United States)

2013-04-08T23:59:59.000Z

13

Oxidation Resistant Graphite Studies  

SciTech Connect (OSTI)

The Very High Temperature Reactor (VHTR) Graphite Research and Development Program is investigating doped nuclear graphite grades exhibiting oxidation resistance. During a oxygen ingress accident the oxidation rates of the high temperature graphite core region would be extremely high resulting in significant structural damage to the core. Reducing the oxidation rate of the graphite core material would reduce the structural effects and keep the core integrity intact during any air-ingress accident. Oxidation testing of graphite doped with oxidation resistant material is being conducted to determine the extent of oxidation rate reduction. Nuclear grade graphite doped with varying levels of Boron-Carbide (B4C) was oxidized in air at nominal 740°C at 10/90% (air/He) and 100% air. The oxidation rates of the boronated and unboronated graphite grade were compared. With increasing boron-carbide content (up to 6 vol%) the oxidation rate was observed to have a 20 fold reduction from unboronated graphite. Visual inspection and uniformity of oxidation across the surface of the specimens were conducted. Future work to determine the remaining mechanical strength as well as graphite grades with SiC doped material are discussed.

W. Windes; R. Smith

2014-07-01T23:59:59.000Z

14

JAPAN: Investment in Graphite  

Science Journals Connector (OSTI)

JAPAN: Investment in Graphite ... Union Carbide, attempting entry into Japan's graphite electrode industry, has just had one obstacle removed from its path by the Fair Trade Commission in Tokyo. ... In deciding that the company's proposed joint venture with Nippon Carbon Co. conforms with provision's of Japan's antimonopoly law, FTC has improved the prospects for a new tactic in the often difficult process of foreign direct investment in Japanese production firms. ...

1969-08-25T23:59:59.000Z

15

Forming gas treatment of lithium ion battery anode graphite powders  

DOE Patents [OSTI]

The invention provides a method of making a battery anode in which a quantity of graphite powder is provided. The temperature of the graphite powder is raised from a starting temperature to a first temperature between 1000 and 2000.degree. C. during a first heating period. The graphite powder is then cooled to a final temperature during a cool down period. The graphite powder is contacted with a forming gas during at least one of the first heating period and the cool down period. The forming gas includes H.sub.2 and an inert gas.

Contescu, Cristian Ion; Gallego, Nidia C; Howe, Jane Y; Meyer, III, Harry M; Payzant, Edward Andrew; Wood, III, David L; Yoon, Sang Young

2014-09-16T23:59:59.000Z

16

Graphite Gamma Scan Results  

SciTech Connect (OSTI)

This report documents the measurement and data analysis of the radio isotopic content for a series of graphite specimens irradiated in the first Advanced Graphite Creep (AGC) experiment, AGC-1. This is the first of a series of six capsules planned as part of the AGC experiment to fully characterize the neutron irradiation effects and radiation creep behavior of current nuclear graphites. The AGC-1 capsule was irradiated in the Advanced Test Reactor (ATR) at INL at approximately 700 degrees C and to a peak dose of 7 dpa (displacements per atom). Details of the irradiation conditions and other characterization measurements performed on specimens in the AGC-1 capsule can be found in “AGC-1 Specimen Post Irradiation Data Report” ORNL/TM 2013/242. Two specimens from six different graphite types are analyzed here. Each specimen is 12.7 mm in diameter by 25.4 mm long. The isotope with the highest activity was 60Co. Graphite type NBG-18 had the highest content of 60Co with an activity of 142.89 µCi at a measurement distance of 47 cm.

Mark W. Drigert

2014-04-01T23:59:59.000Z

17

Phase diagram and phase transitions of monolayer and bilayer CF4 on graphite  

Science Journals Connector (OSTI)

The phase diagram of CF4 adsorbed on graphite in the monolayer and bilayer region is mapped out in an ac heat-capacity study. In the monolayer region, the resultant phase diagram shows the existence of five different solid phases. The melting transition can proceed from the (2×2) commensurate, I(S) (an incommensurate phase), and the hexagonal incommensurate (HI) phases. Strongly-first-order melting is found from the (2×2) and the I(S) phases. In contrast, a sharp and small heat-capacity peak followed by a broad anomaly, similar to the melting of Ar on graphite in the submonolayer region, is observed at the melting of the HI phase. In the bilayer region, four different regions of coexisting solid phases are found. The melting of the bilayer solid occurs at a triple point at 89.05 K. Our data also suggest a bilayer critical point at 93 K.

Q. M. Zhang; H. K. Kim; M. H. W. Chan

1986-12-01T23:59:59.000Z

18

Irradiation Creep in Graphite  

SciTech Connect (OSTI)

An understanding of the underlying mechanisms of irradiation creep in graphite material is required to correctly interpret experimental data, explain micromechanical modeling results, and predict whole-core behavior. This project will focus on experimental microscopic data to demonstrate the mechanism of irradiation creep. High-resolution transmission electron microscopy should be able to image both the dislocations in graphite and the irradiation-induced interstitial clusters that pin those dislocations. The team will first prepare and characterize nanoscale samples of virgin nuclear graphite in a transmission electron microscope. Additional samples will be irradiated to varying degrees at the Advanced Test Reactor (ATR) facility and similarly characterized. Researchers will record microstructures and crystal defects and suggest a mechanism for irradiation creep based on the results. In addition, the purchase of a tensile holder for a transmission electron microscope will allow, for the first time, in situ observation of creep behavior on the microstructure and crystallographic defects.

Ubic, Rick; Butt, Darryl; Windes, William

2014-03-13T23:59:59.000Z

19

Improved graphite furnace atomizer  

DOE Patents [OSTI]

A graphite furnace atomizer for use in graphite furnace atomic absorption spectroscopy is described wherein the heating elements are affixed near the optical path and away from the point of sample deposition, so that when the sample is volatilized the spectroscopic temperature at the optical path is at least that of the volatilization temperature, whereby analyteconcomitant complex formation is advantageously reduced. The atomizer may be elongated along its axis to increase the distance between the optical path and the sample deposition point. Also, the atomizer may be elongated along the axis of the optical path, whereby its analytical sensitivity is greatly increased.

Siemer, D.D.

1983-05-18T23:59:59.000Z

20

Diamond-graphite field emitters  

DOE Patents [OSTI]

A field emission electron emitter comprising an electrode of diamond and a conductive carbon, e.g., graphite, is provided.

Valone, Steven M. (Santa Fe, NM)

1997-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "melting includes graphite" 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

Raman spectroscopy of graphite  

Science Journals Connector (OSTI)

...G for graphite. The other modes are either observed only on defective samples or are very weak in intensity like the G peak that was...al. 2001); a similar behaviour is also observed in other car- bon materials (Ferrari & Robertson 2001; Maultzsch et al...

2004-01-01T23:59:59.000Z

22

Polymer-Graphite Nanocomposites: Effective Dispersion and Major Property Enhancement via  

E-Print Network [OSTI]

/kinetic limitations associated with con- ventional processes. With SSSP, a modified twin-screw extruder applies shear-44 provide details on the SSSP process and equipment; parameters (screw design, barrel size, feed rate, etc with similar filler content was fabricated via single-screw melt extrusion (Randcastle RCP-0625). Graphite

23

Using Graphite to view network data  

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

Graphite Graphite to Visualize Network Data Jon Dugan Summer ESCC 2010, Columbus, OH Lawrence Berkeley National Laboratory U.S. Department of Energy | Office of Science ESnet Statistics Overview ESxSNMP (Data Collection) ESxSNMP (Data Collection) Graphite (Visualization) Graphite (Visualization) Analytics (Custom Reports) Analytics (Custom Reports) Net Almanac (Metadata) Net Almanac (Metadata) Lawrence Berkeley National Laboratory U.S. Department of Energy | Office of Science What is Graphite? "Enterprise scalable realtime graphing" * Developed by Orbitz for visualizing internal performance data * Open source: https://launchpad.net/graphite * Has own RRD like database called Carbon * RRD Compatible ESxSNMP Integration * via REST interface * Easy integration, Graphite is well written

24

From ‘Green’ Aerogels to Porous Graphite by Emulsion Gelation of Acrylonitrile  

Science Journals Connector (OSTI)

From ‘Green’ Aerogels to Porous Graphite by Emulsion Gelation of Acrylonitrile ... Ambient pressure drying of wet-gels from copolymeri-zation of acrylonitrile and bifunctional cross-linkers either in toluene or in H2O-based emulsions yields structurally similar PAN aerogels, which are converted to monolithic porous carbons and graphite. ... Porous carbons, including carbon (C-) aerogels, are technologically important materials, while polyacrylonitrile (PAN) is the main industrial source of graphite fiber. ...

Anand G. Sadekar; Shruti S. Mahadik; Abhishek N. Bang; Zachary J. Larimore; Clarissa A. Wisner; Massimo F. Bertino; A. Kaan Kalkan; Joseph T. Mang; Chariklia Sotiriou-Leventis; Nicholas Leventis

2011-12-14T23:59:59.000Z

25

Hydrogen Storage in Graphite Nanofibers  

Science Journals Connector (OSTI)

Hydrogen Storage in Graphite Nanofibers ... Subsequent lowering of the pressure to nearly atmospheric conditions results in the release of a major fraction of the stored hydrogen at room temperature. ...

Alan Chambers; Colin Park; R. Terry K. Baker; Nelly M. Rodriguez

1998-05-12T23:59:59.000Z

26

Graphite electrode DC arc furnace. Innovative technology summary report  

SciTech Connect (OSTI)

The Graphite Electrode DC Arc Furnace (DC Arc) is a high-temperature thermal process, which has been adapted from a commercial technology, for the treatment of mixed waste. A DC Arc Furnace heats waste to a temperature such that the waste is converted into a molten form that cools into a stable glassy and/or crystalline waste form. Hazardous organics are destroyed through combustion or pyrolysis during the process and the majority of the hazardous metals and radioactive components are incorporated in the molten phase. The DC Arc Furnace chamber temperature is approximately 593--704 C and melt temperatures are as high as 1,500 C. The DC Arc system has an air pollution control system (APCS) to remove particulate and volatiles from the offgas. The advantage of the DC Arc is that it is a single, high-temperature thermal process that minimizes the need for multiple treatment systems and for extensive sorting/segregating of large volumes of waste. The DC Arc has the potential to treat a wide range of wastes, minimize the need for sorting, reduce the final waste volumes, produce a leach resistant waste form, and destroy organic contaminants. Although the DC arc plasma furnace exhibits great promise for treating the types of mixed waste that are commonly present at many DOE sites, several data and technology deficiencies were identified by the Mixed Waste Focus Area (MWFA) regarding this thermal waste processing technique. The technology deficiencies that have been addressed by the current studies include: establishing the partitioning behavior of radionuclides, surrogates, and hazardous metals among the product streams (metal, slag, and offgas) as a function of operating parameters, including melt temperature, plenum atmosphere, organic loading, chloride concentration, and particle size; demonstrating the efficacy of waste product removal systems for slag and metal phases; determining component durability through test runs of extended duration, evaluating the effect of feed composition variations on process operating conditions and slag product performance; and collecting mass balance and operating data to support equipment and instrument design.

NONE

1999-05-01T23:59:59.000Z

27

Melting of hard cubes  

Science Journals Connector (OSTI)

The melting transition of a system of hard cubes is studied numerically both in the case of freely rotating cubes and when there is a fixed orientation of the particles: parallel cubes. It is shown that freely rotating cubes melt through a first-order transition, whereas parallel cubes have a continuous transition in which positional order is lost but bond-orientational order remains finite. This is interpreted in terms of a defect-mediated theory of melting.

E. A. Jagla

1998-10-01T23:59:59.000Z

28

Viscosity of Silicate Melts.  

E-Print Network [OSTI]

??Viscosity of silicate melts is of fundamental importance in understanding volcanic and magmatic processes in Earth. In this dissertation, experiments were conducted to obtain high-pressure… (more)

Hui, Hejiu

2008-01-01T23:59:59.000Z

29

Sandia National Laboratories: Molten Salt Test Loop Melted Salt  

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

melter, and completed the melting in less than 4 days. The outstanding effort included CSP group engineers and technologists, safety, industrial health, and ergonomics experts,...

30

AGC-2 Graphite Preirradiation Data Package  

SciTech Connect (OSTI)

The NGNP Graphite R&D program is currently establishing the safe operating envelope of graphite core components for a Very High Temperature Reactor (VHTR) design. The program is generating quantitative data necessary for predicting the behavior and operating performance of the new nuclear graphite grades. To determine the in-service behavior of the graphite for pebble bed and prismatic designs, the Advanced Graphite Creep (AGC) experiment is underway. This experiment is examining the properties and behavior of nuclear grade graphite over a large spectrum of temperatures, neutron fluences and compressive loads. Each experiment consists of over 400 graphite specimens that are characterized prior to irradiation and following irradiation. Six experiments are planned with the first, AGC-1, currently being irradiated in the Advanced Test Reactor (ATR) and pre-irradiation characterization of the second, AGC-2, completed. This data package establishes the readiness of 512 specimens for assembly into the AGC-2 capsule.

David Swank; Joseph Lord; David Rohrbaugh; William Windes

2012-10-01T23:59:59.000Z

31

Chemical kinetics parameters of nuclear graphite gasification  

Science Journals Connector (OSTI)

This paper provides chemical kinetics parameters for the gasification of nuclear graphite grades of IG-110, IG-430, NBG-18 and NBG-25 and presents empirical correlations for their surface areas of free active sites as a function of mass. The kinetics parameters for the four elementary chemical reactions of gasification of these grades of nuclear graphite include the values and Gaussian distributions of the specific activation energies and the values of the pre-exponential rate coefficients for the adsorption of oxygen and desorption of CO and CO2 gases. The values of these parameters and the surface area of free active sites for IG-110 and NB-25, with fine and medium petroleum coke filler particles, are nearly the same, but slightly different from those of NBG-18 and IG-430, with medium and fine coal tar pitch coke filler particles. Recommended parameters are applicable to future safety analysis of high and very high temperature gas cooled reactors in the unlikely event of a massive air ingress accident.

Mohamed S. El-Genk; Jean-Michel P. Tournier

2013-01-01T23:59:59.000Z

32

Graphite Reactor | ornl.gov  

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

Graphite Reactor Graphite Reactor 'In the early, desperate days of World War II, the United States launched the top-secret, top-priority Manhattan Project...' In the early, desperate days of U.S. involvement in World War II, American scientists began to fear that the German discovery of uranium fission in 1939 might enable the Nazis to develop a super bomb. Afraid of losing this crucial race, the United States launched the top-secret, top-priority Manhattan Project. The plan was to create two atomic weapons-one fueled by plutonium, the other by enriched uranium. Hanford, Washington, was selected as the site for plutonium production, but before large reactors could be built there, a pilot plant was necessary to prove the feasibility of scaling up from laboratory experiments. A secluded, rural area near Clinton, Tennessee, was

33

Environmentally benign graphite intercalation compound composition for exfoliated graphite, flexible graphite, and nano-scaled graphene platelets  

SciTech Connect (OSTI)

A carboxylic-intercalated graphite compound composition for the production of exfoliated graphite, flexible graphite, or nano-scaled graphene platelets. The composition comprises a layered graphite with interlayer spaces or interstices and a carboxylic acid residing in at least one of the interstices, wherein the composition is prepared by a chemical oxidation reaction which uses a combination of a carboxylic acid and hydrogen peroxide as an intercalate source. Alternatively, the composition may be prepared by an electrochemical reaction, which uses a carboxylic acid as both an electrolyte and an intercalate source. Exfoliation of the invented composition does not release undesirable chemical contaminants into air or drainage.

Zhamu, Aruna; Jang, Bor Z.

2014-06-17T23:59:59.000Z

34

Study of ice and snow melting process on conductive asphalt solar collector  

Science Journals Connector (OSTI)

This paper investigates the snow melting process on asphalt pavements as solar collector by experiments and numerical simulation. A numerical simulation method was used to predict the general design requirements for snow melting system of asphalt pavements, and a type of experimental asphalt snow melting system has been built using the design parameters obtained from the preceding simulation. Graphite powders were used to improve the thermal conductivity of asphalt concrete and thus resulting in an improved efficiency of asphalt collector. A laboratory snow melting test was performed after real snowstorm events. The effects of thermal conductive asphalt concrete (CAC) on snow melting performance and asphalt pavement temperature distribution were evaluated. The heat transfer in the asphalt slabs and the heat requirement for the snow melting were analyzed. The results that are obtained show that asphalt solar collector (ASC) provides us a better alternative method for snow melting. The higher fluid temperature is a positive way to improve the performance of snow melting system. However, it is unnecessary to keep a too high fluid temperature so as to reduce the waste of energy. The non-uniform temperatures in the asphalt slabs are noticeable. Furthermore, the heat-transmission and the snow melting performance can be enhanced using CAC.

Mingyu Chen; Shaopeng Wu; Hong Wang; Jizhe Zhang

2011-01-01T23:59:59.000Z

35

X-10 Graphite Reactor | Department of Energy  

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

X-10 Graphite Reactor X-10 Graphite Reactor X-10 Graphite Reactor X-10 Graphite Reactor When President Roosevelt in December 1942 authorized the Manhattan Project, the Oak Ridge site in eastern Tennessee had already been obtained and plans laid for an air-cooled experimental pile, a pilot chemical separation plant, and support facilities. The X-10 Graphite Reactor, designed and built in ten months, went into operation on November 4, 1943. The X-10 used neutrons emitted in the fission of uranium-235 to convert uranium-238 into a new element, plutonium-239. The reactor consists of a huge block of graphite, measuring 24 feet on each side, surrounded by several feet of high-density concrete as a radiation shield. The block is pierced by 1,248 horizontal diamond-shaped channels in

36

Uranium Oxide Aerosol Transport in Porous Graphite  

SciTech Connect (OSTI)

The objective of this paper is to investigate the transport of uranium oxide particles that may be present in carbon dioxide (CO2) gas coolant, into the graphite blocks of gas-cooled, graphite moderated reactors. The transport of uranium oxide in the coolant system, and subsequent deposition of this material in the graphite, of such reactors is of interest because it has the potential to influence the application of the Graphite Isotope Ratio Method (GIRM). The GIRM is a technology that has been developed to validate the declared operation of graphite moderated reactors. GIRM exploits isotopic ratio changes that occur in the impurity elements present in the graphite to infer cumulative exposure and hence the reactor’s lifetime cumulative plutonium production. Reference Gesh, et. al., for a more complete discussion on the GIRM technology.

Blanchard, Jeremy; Gerlach, David C.; Scheele, Randall D.; Stewart, Mark L.; Reid, Bruce D.; Gauglitz, Phillip A.; Bagaasen, Larry M.; Brown, Charles C.; Iovin, Cristian; Delegard, Calvin H.; Zelenyuk, Alla; Buck, Edgar C.; Riley, Brian J.; Burns, Carolyn A.

2012-01-23T23:59:59.000Z

37

Graphitized-carbon fiber/carbon char fuel  

DOE Patents [OSTI]

A method for recovery of intact graphitic fibers from fiber/polymer composites is described. The method comprises first pyrolyzing the graphite fiber/polymer composite mixture and then separating the graphite fibers by molten salt electrochemical oxidation.

Cooper, John F. (Oakland, CA)

2007-08-28T23:59:59.000Z

38

Polyelectrolyte-Induced Reduction of Exfoliated Graphite Oxide...  

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

Reduction of Exfoliated Graphite Oxide: A Facile Route to Synthesis of Soluble Graphene Nanosheets. Polyelectrolyte-Induced Reduction of Exfoliated Graphite Oxide: A Facile...

39

PIA - 10th International Nuclear Graphite Specialists Meeting...  

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

PIA - 10th International Nuclear Graphite Specialists Meeting registration web site PIA - 10th International Nuclear Graphite Specialists Meeting registration web site PIA - 10th...

40

Inhibition of Oxidation in Nuclear Graphite  

SciTech Connect (OSTI)

Graphite is a fundamental material of high temperature gas cooled nuclear reactors, providing both structure and neutron moderation. Its high thermal conductivity, chemical inertness, thermal heat capacity, and high thermal structural stability under normal and off normal conditions contribute to the inherent safety of these reactor designs. One of the primary safety issues for a high temperature graphite reactor core is the possibility of rapid oxidation of the carbon structure during an off normal design basis event where an oxidizing atmosphere (air ingress) can be introduced to the hot core. Although the current Generation IV high temperature reactor designs attempt to mitigate any damage caused by a postualed air ingress event, the use of graphite components that inhibit oxidation is a logical step to increase the safety of these reactors. Recent experimental studies of graphite containing between 5.5 and 7 wt% boron carbide (B4C) indicate that oxidation is dramatically reduced even at prolonged exposures at temperatures up to 900°C. The proposed addition of B4C to graphite components in the nuclear core would necessarily be enriched in B-11 isotope in order to minimize B-10 neutron absorption and graphite swelling. The enriched boron can be added to the graphite during billet fabrication. Experimental oxidation rate results and potential applications for borated graphite in nuclear reactor components will be discussed.

Phil Winston; James W. Sterbentz; William E. Windes

2013-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "melting includes graphite" 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

Microstructural Characterization of Next Generation Nuclear Graphites  

SciTech Connect (OSTI)

This article reports the microstructural characteristics of various petroleum and pitch based nuclear graphites (IG-110, NBG-18, and PCEA) that are of interest to the next generation nuclear plant program. Bright-field transmission electron microscopy imaging was used to identify and understand the different features constituting the microstructure of nuclear graphite such as the filler particles, microcracks, binder phase, rosette-shaped quinoline insoluble (QI) particles, chaotic structures, and turbostratic graphite phase. The dimensions of microcracks were found to vary from a few nanometers to tens of microns. Furthermore, the microcracks were found to be filled with amorphous carbon of unknown origin. The pitch coke based graphite (NBG-18) was found to contain higher concentration of binder phase constituting QI particles as well as chaotic structures. The turbostratic graphite, present in all of the grades, was identified through their elliptical diffraction patterns. The difference in the microstructure has been analyzed in view of their processing conditions.

Karthik Chinnathambi; Joshua Kane; Darryl P. Butt; William E. Windes; Rick Ubic

2012-04-01T23:59:59.000Z

42

Enhancing thermal conductivity of fluids with graphite nanoparticles and carbon nanotube  

DOE Patents [OSTI]

A fluid media such as oil or water, and a selected effective amount of carbon nanomaterials necessary to enhance the thermal conductivity of the fluid. One of the preferred carbon nanomaterials is a high thermal conductivity graphite, exceeding that of the neat fluid to be dispersed therein in thermal conductivity, and ground, milled, or naturally prepared with mean particle size less than 500 nm, and preferably less than 200 nm, and most preferably less than 100 nm. The graphite is dispersed in the fluid by one or more of various methods, including ultrasonication, milling, and chemical dispersion. Carbon nanotubes with graphitic structure is another preferred source of carbon nanomaterial, although other carbon nanomaterials are acceptable. To confer long term stability, the use of one or more chemical dispersants is preferred. The thermal conductivity enhancement, compared to the fluid without carbon nanomaterial, is proportional to the amount of carbon nanomaterials (carbon nanotubes and/or graphite) added.

Zhang, Zhiqiang (Lexington, KY); Lockwood, Frances E. (Georgetown, KY)

2008-03-25T23:59:59.000Z

43

Graphite Oxidation Thermodynamics/Reactions  

SciTech Connect (OSTI)

The vulnerability of graphite-matrix spent nuclear fuel to oxidation by the ambient atmosphere if the fuel canister is breached was evaluated. Thermochemical and kinetic data over the anticipated range of storage temperatures (200 to 400 C) were used to calculate the times required for a total carbon mass loss of 1 mgcm-2 from a fuel specimen. At 200 C, the time required to produce even this small loss is large, 900,000 yr. However, at 400 C the time required is only 1.9 yr. The rate of oxidation at 200 C is negligible, and the rate even at 400 C is so small as to be of no practical consequence. Therefore, oxidation of the spent nuclear fuel upon a loss of canister integrity is not anticipated to be a concern based upon the results of this study.

Propp, W.A.

1998-09-01T23:59:59.000Z

44

Ethylene on graphite: A low-energy electron-diffraction study  

Science Journals Connector (OSTI)

Several phases of monolayer ethylene on single-crystal graphite have been studied using low-energy electron diffraction. We have determined the unit cell and orientation with respect to the graphite substrate of the orientationally ordered and disordered low-density phases (OLD and DLD), in which molecules are believed to lie with the C?C bond parallel to the surface. Based on published neutron-scattering results, we propose a basis for the OLD phase. The low-coverage DLD phase, believed to undergo a continuous melting transition at 70 K, appears to be a higher-order commensurate structure at this transition. We also report observations of ordered and disordered high-density phases in which molecules stand on end, in both commensurate and incommensurate epitaxies.

V. L. Eden and S. C. Fain; Jr.

1991-05-01T23:59:59.000Z

45

Melt Rate Improvement for DWPF MB3: Foaming Theory and Mitigation Techniques  

SciTech Connect (OSTI)

The objective of this research is to enhance the basic understanding of the role of glass chemistry, including the chemical kinetics of pre-melting, solid state reactions, batch melting, and the reaction pathways in glass and/or acid addition strategy changes on the overall melting process for the Defense Waste Processing Facility (DWPF) Macrobatch 3 (MB3).

Peeler, D.K.

2001-07-24T23:59:59.000Z

46

Strength scaling of brittle graphitic foam  

Science Journals Connector (OSTI)

...many different type of open- and closed-cell solids such as aerogels (Pekala et al. 1991), graphitic foams (Brezny & Green...mechanical properties and scaling law relationships for silica aerogels and their organic counterparts. Mater. Res. Soc. Symp...

2002-01-01T23:59:59.000Z

47

Immobilization of Rocky Flats Graphite Fines Residue  

SciTech Connect (OSTI)

The development of the immobilization process for graphite fines has proceeded through a series of experimental programs. The experimental procedures and results from each series of experiments are discussed in this report.

Rudisill, T.S.

1999-04-06T23:59:59.000Z

48

Pyrolytic graphite production : automation of material placement  

E-Print Network [OSTI]

This research examines the process and challenges associated with the addition of an autonomous transfer robot to a manufacturing line for AvCarb Material Solutions for use in production of pyrolytic graphite. Development ...

Olle, Chase R

2014-01-01T23:59:59.000Z

49

Electric Resistivity of Interstitial Compounds of Graphite  

Science Journals Connector (OSTI)

Assuming that the formation of interstitial compounds is accompanied by creation of excess holes in the otherwise full band of graphite it is shown that a linear energy?momentum relation at the Brillouin zone corners is incapable of explaining the decrease of the electric resistance with oxidation. It appears that for a more general model the decrease in relative resistance should be independent of temperature for large oxidations if suitable corrections for the initial conditions are made. Data for polycrystallinegraphite corrected for the existence of an energy gap and of excess holes in the untreated material give curves which converge for higher oxidation with the curve for natural graphite. Discussion of the low temperature properties of graphite leads to the conclusion that large graphite crystals possess slightly overlapping zones.

S. Mrozowski

1953-01-01T23:59:59.000Z

50

Statistical Comparison of the Baseline Mechanical Properties of NBG-18 and PCEA Graphite  

SciTech Connect (OSTI)

High-purity graphite is the core structural material of choice in the Very High Temperature Reactor (VHTR), a graphite-moderated, helium-cooled design that is capable of producing process heat for power generation and for industrial process that require temperatures higher than the outlet temperatures of present nuclear reactors. The Baseline Graphite Characterization Program is endeavoring to minimize the conservative estimates of as-manufactured mechanical and physical properties by providing comprehensive data that captures the level of variation in measured values. In addition to providing a comprehensive comparison between these values in different nuclear grades, the program is also carefully tracking individual specimen source, position, and orientation information in order to provide comparisons and variations between different lots, different billets, and different positions from within a single billet. This report is a preliminary comparison between the two grades of graphite that were initially favored in the two main VHTR designs. NBG-18, a medium-grain pitch coke graphite from SGL formed via vibration molding, was the favored structural material in the pebble-bed configuration, while PCEA, a smaller grain, petroleum coke, extruded graphite from GrafTech was favored for the prismatic configuration. An analysis of the comparison between these two grades will include not only the differences in fundamental and statistically-significant individual strength levels, but also the differences in variability in properties within each of the grades that will ultimately provide the basis for the prediction of in-service performance. The comparative performance of the different types of nuclear grade graphites will continue to evolve as thousands more specimens are fully characterized from the numerous grades of graphite being evaluated.

Mark C. Carroll; David T. Rohrbaugh

2013-08-01T23:59:59.000Z

51

Method of producing exfoliated graphite, flexible graphite, and nano-scaled graphene platelets  

DOE Patents [OSTI]

The present invention provides a method of exfoliating a layered material (e.g., graphite and graphite oxide) to produce nano-scaled platelets having a thickness smaller than 100 nm, typically smaller than 10 nm. The method comprises (a) dispersing particles of graphite, graphite oxide, or a non-graphite laminar compound in a liquid medium containing therein a surfactant or dispersing agent to obtain a stable suspension or slurry; and (b) exposing the suspension or slurry to ultrasonic waves at an energy level for a sufficient length of time to produce separated nano-scaled platelets. The nano-scaled platelets are candidate reinforcement fillers for polymer nanocomposites. Nano-scaled graphene platelets are much lower-cost alternatives to carbon nano-tubes or carbon nano-fibers.

Zhamu, Aruna (Centerville, OH); Shi, Jinjun (Columbus, OH); Guo, Jiusheng (Centerville, OH); Jang, Bor Z. (Centerville, OH)

2010-11-02T23:59:59.000Z

52

Removal of {sup 14}C from Irradiated Graphite for Graphite Recycle and Waste Volume Reduction  

SciTech Connect (OSTI)

The aim of the research presented here was to identify the checmical from of {sup 14}C inirradiated graphite. A greater understanding of the chemical form of this longest-lived isotope in irradiated graphite will inform not only management of legacy waste, but also development of next generation gas-cooled reactors. Approimately 250,000 metric tons of irradiated graphite waste exists worldwide, with the largest single quantity originating in the Magnox and AGR reactors of UK. The waste quantity is expected to increase with decommissioning of Generation II reactors and deployment of Generation I gas-cooled, graphite moderated reactors. Of greatest concern for long-term disposal of irradiated graphite is carbon-14 ({sup 14}C), with a half-life of 5730 years.

Dunzik-Gougar, Mary Lou; Windes, Will; Marsden, Barry

2014-06-10T23:59:59.000Z

53

Reduced Energy Consumption for Melting in Foundries  

E-Print Network [OSTI]

Reduced Energy Consumption for Melting in Foundries Ph.D. Thesis by Søren Skov-Hansen Supervisor-melted, and hence reduce the energy consumption for melting in foundries. Traditional gating systems are known

54

Brookhaven Graphite Research Reactor | Environmental Restoration Projects |  

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

Brookhaven Graphite Research Reactor Documents Brookhaven Graphite Research Reactor Documents Feasibility Study (PDF) Proposed Remedial Action Plan (PDF) Record of Decision (PDF) RD/RA Work Plan for the BGRR Pile (PDF) RD/RA Work Plan for the Bioshield (PDF) RD/RA Work Plan for the BGRR Cap (PDF) Brookhaven Graphite Research Reactor Explanation of Significant Differences (PDF) (4/12) NYSDEC Approval Letter for BGRR ESD (PDF) (5/12) USEPA Approval Letter for BGRR ESD (PDF) (6/12) DOE BGRR ESD Transmittal Letter (PDF) (7/12) Remedial Design Implementation Report (PDF) (12/11) Completion Reports Removal of the Above-Ground Ducts and Preparation of the Instrument House (708) for Removal (PDF) - April 2002 Below-Ground Duct Outlet Air Coolers, Filters and Primary Liner Removal (PDF) - April 2005 Canal and Deep Soil Pockets Excavation and Removal (PDF) - August

55

Aerosol and graphitic carbon content of snow  

SciTech Connect (OSTI)

Snow samples from southern New Mexico, west Texas, Antarctica, and Greenland were analyzed for aerosol and graphitic carbon. Graphitic carbon contents were found to be between 2.2 and 25 ..mu..g L/sup -1/ of snow meltwater; water-insoluble aerosol content varied between 0.62 and 8.5 mg L/sup -1/. For comparison, two samples of Camp Century, Greenland, ice core, having approximate ages of 4,000 and 6,000 years, were also analyzed. Ice core graphitic carbon contents were found to be 2.5 and 1.1 ..mu..g L/sup -1/. copyrightAmerican Geophysical Union 1987

Chy-acute-accentlek, P.; Srivastava, V.; Cahenzli, L.; Pinnick, R.G.; Dod, R.L.; Novakov, T.; Cook, T.L.; Hinds, B.D.

1987-08-20T23:59:59.000Z

56

Engineered Graphite Oxide Materials for Application in Water Purification  

Science Journals Connector (OSTI)

Engineered Graphite Oxide Materials for Application in Water Purification ... The research results could open avenues for developing low-cost water purification materials for the developing economies. ... water purification; graphite oxide; mercury removal; diazonium chemistry; Rhodamine B; sand coating ...

Wei Gao; Mainak Majumder; Lawrence B. Alemany; Tharangattu N. Narayanan; Miguel A. Ibarra; Bhabendra K. Pradhan; Pulickel M. Ajayan

2011-05-13T23:59:59.000Z

57

Characterization of exfoliated graphite for heavy oil sorption  

Science Journals Connector (OSTI)

In this paper are reported some experimental data related to the influence of preparation regimes and characteristics of exfoliated graphite based sorbents produced by thermal expansion of H2SO4-graphite intercal...

Gabriela Hristea; P. Budrugeac

2008-03-01T23:59:59.000Z

58

Some optical properties of graphite from IR to millimetric wavelengths  

Science Journals Connector (OSTI)

......powder obtained by striking an electric arc from graphitic electrodes in an...the material from the exciting electric field and more energy is scattered...graphitic material from electrical discharges in various gases, TH, BE, XY......

Robert J. Papoular; Renaud Papoular

2014-10-01T23:59:59.000Z

59

GlassMelt&Sealing  

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

Glass Melting and Sealing Glass Melting and Sealing Manufacturing Technologies The Manufacturing Science & Technology Center performs process development of glass and glass-ceramic-to-metal seals. Small batches of specialty glass can be melted from reagent grade oxide powders. Glass and glass-ceramic-to-metal seals are made in microprocessor controlled inert atmospheres and are checked for her- meticity after sealing. Sandia's extensive properties database of low melting solder glasses is used to aid in material and processing decisions when making glass-to-glass, ceramic-to-ceramic, and glass-to-ceramic seals. These seals are typically done in air at much lower tem- peratures than glass and glass-to-ceramic seals. Capabilities * Interface with designers and vendors to assure that the most appropriate materi-

60

Viscosity of Ring Polymer Melts  

Science Journals Connector (OSTI)

Viscosity of Ring Polymer Melts ... The ratio of the zero-shear viscosities of linear polymer melts ?0,linear to their ring counterparts ?0,ring at isofrictional conditions is discussed as a function of the number of entanglements Z. ... For this reason we have determined the viscosities by fitting the complex viscosity curves with different methods to obtain reliable estimates and error bars (see Supporting Information). ...

Rossana Pasquino; Thodoris C. Vasilakopoulos; Youn Cheol Jeong; Hyojoon Lee; Simon Rogers; George Sakellariou; Jürgen Allgaier; Atsushi Takano; Ana R. Brás; Taihyun Chang; Sebastian Gooßen; Wim Pyckhout-Hintzen; Andreas Wischnewski; Nikos Hadjichristidis; Dieter Richter; Michael Rubinstein; Dimitris Vlassopoulos

2013-09-17T23:59:59.000Z

Note: This page contains sample records for the topic "melting includes graphite" 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.


61

Scaleable Clean Aluminum Melting Systems  

SciTech Connect (OSTI)

The project entitled 'Scaleable Clean Aluminum Melting Systems' was a Cooperative Research and Development Agreements (CRADAs) between Oak Ridge National Laboratory (ORNL) and Secat Inc. The three-year project was initially funded for the first year and was then canceled due to funding cuts at the DOE headquarters. The limited funds allowed the research team to visit industrial sites and investigate the status of using immersion heaters for aluminum melting applications. Primary concepts were proposed on the design of furnaces using immersion heaters for melting. The proposed project can continue if the funding agency resumes the funds to this research. The objective of this project was to develop and demonstrate integrated, retrofitable technologies for clean melting systems for aluminum in both the Metal Casting and integrated aluminum processing industries. The scope focused on immersion heating coupled with metal circulation systems that provide significant opportunity for energy savings as well as reduction of melt loss in the form of dross. The project aimed at the development and integration of technologies that would enable significant reduction in the energy consumption and environmental impacts of melting aluminum through substitution of immersion heating for the conventional radiant burner methods used in reverberatory furnaces. Specifically, the program would couple heater improvements with furnace modeling that would enable cost-effective retrofits to a range of existing furnace sizes, reducing the economic barrier to application.

Han, Q.; Das, S.K. (Secat, Inc.)

2008-02-15T23:59:59.000Z

62

Method of making segmented pyrolytic graphite sputtering targets  

DOE Patents [OSTI]

Anisotropic pyrolytic graphite wafers are oriented and bonded together such that the graphite's high thermal conductivity planes are maximized along the back surface of the segmented pyrolytic graphite target to allow for optimum heat conduction away from the sputter target's sputtering surface and to allow for maximum energy transmission from the target's sputtering surface. 2 figures.

McKernan, M.A.; Alford, C.S.; Makowiecki, D.M.; Chen, C.W.

1994-02-08T23:59:59.000Z

63

Carbon nanomaterial produced by microwave exfoliation of graphite oxide: new insights.  

SciTech Connect (OSTI)

We present detailed characterization of graphene-like material obtained through microwave stimulated exfoliation of graphite oxide (GO). Properties of this material were studied by multiple techniques including, among others, X-ray photoelectron spectroscopy, mass-spectroscopy, infrared and Raman spectroscopy, scanning electron microscopy and broadband dielectric spectroscopy. Specific surface area and volume of microwave exfoliated graphite oxide reached 600 m2 g1 and 6 cm3 g1, respectively. It is shown that during such an explosive reduction process the sample emits CO2, CO and H2O and, in some cases, SO2 gases. The resulting reduced material exhibits IR spectra similar to that of graphite and a dc-conductivity of 0.12 S cm1.

Shulga, Y.M. [Institute of Problems of Chemical Physics, Russian Ac. Sci, Chernogolovka, Russia] [Institute of Problems of Chemical Physics, Russian Ac. Sci, Chernogolovka, Russia; Baskakov, S.A. [Institute of Problems of Chemical Physics, Russian Ac. Sci, Chernogolovka, Russia] [Institute of Problems of Chemical Physics, Russian Ac. Sci, Chernogolovka, Russia; Knerelman, E.I. [Institute of Problems of Chemical Physics, Russian Ac. Sci, Chernogolovka, Russia] [Institute of Problems of Chemical Physics, Russian Ac. Sci, Chernogolovka, Russia; Davidova, G.I. [Institute of Problems of Chemical Physics, Russian Ac. Sci, Chernogolovka, Russia] [Institute of Problems of Chemical Physics, Russian Ac. Sci, Chernogolovka, Russia; Badamshina, E.R. [Institute of Problems of Chemical Physics, Russian Ac. Sci, Chernogolovka, Russia] [Institute of Problems of Chemical Physics, Russian Ac. Sci, Chernogolovka, Russia; Shulga, N. Yu. [National University of Science and Technology MISiS, Moscow, Russia] [National University of Science and Technology MISiS, Moscow, Russia; Skryleva, E.A. [National University of Science and Technology MISiS, Moscow, Russia] [National University of Science and Technology MISiS, Moscow, Russia; Agapov, Alexander L [ORNL] [ORNL; Voylov, Dmitry N [ORNL] [ORNL; Sokolov, Alexei P [ORNL] [ORNL; Martynenko, V.M. [Institute of Problems of Chemical Physics, Russian Ac. Sci, Chernogolovka, Russia] [Institute of Problems of Chemical Physics, Russian Ac. Sci, Chernogolovka, Russia

2014-01-01T23:59:59.000Z

64

Environmental Management Brookhaven Graphite Research Reactor  

E-Print Network [OSTI]

-out report · Transition to long-term surveillance and maintenance · Office of Environmental ManagementEnvironmental Management Brookhaven Graphite Research Reactor (BGRR) Project Completion John Sattler Federal Project Director Office of Environmental Management U.S. Department of Energy BNL

Homes, Christopher C.

65

NOVEL GRAPHITE SALTS OF HIGH OXIDIZING POTENTIAL  

E-Print Network [OSTI]

hr volatiles none AsFS AsFS > CF4 AsFS AsFS AsFS C13.l AsF 6C16.l AsF 6 C24.3AsF6·l/2 F2 > CF4> CF4 > CF4 Table VI-7. Graphite hexafluoroarsenate salts +

McCarron III, Eugene Michael

2010-01-01T23:59:59.000Z

66

Phonon dispersion of graphite J. Maultzsch  

E-Print Network [OSTI]

the acoustic branches below 400 cm-1 were measured by inelastic neutron scattering [1]. The optical phonons. The phonon dispersion of graphite was determined by inelastic X-ray scattering along the -K, K-M, and -K. This coupling dominates the scattering mechanism in both electronic transport and Raman scattering. Many

Nabben, Reinhard

67

Excimer laser reduction and patterning of graphite oxide Denis A. Sokolov a  

E-Print Network [OSTI]

of Chemistry and Biochemistry, 901 Atlantic Drive NW, Atlanta, GA 30332-0400, USA b Georgia Institute graphene include exfoliation of graphite [1], epitaxial growth on silicon carbide via silicon sublimation author: Fax: +1 404 3856057. E-mail address: Thomas.Orlando@chemistry.gatech.edu (T.M. Orlando). C A R B

Geohegan, David B.

68

Development of a graphite probe calorimeter for absolute clinical dosimetry  

SciTech Connect (OSTI)

The aim of this work is to present the numerical design optimization, construction, and experimental proof of concept of a graphite probe calorimeter (GPC) conceived for dose measurement in the clinical environment (U.S. provisional patent 61/652,540). A finite element method (FEM) based numerical heat transfer study was conducted using a commercial software package to explore the feasibility of the GPC and to optimize the shape, dimensions, and materials used in its design. A functioning prototype was constructed inhouse and used to perform dose to water measurements under a 6 MV photon beam at 400 and 1000 MU/min, in a thermally insulated water phantom. Heat loss correction factors were determined using FEM analysis while the radiation field perturbation and the graphite to water absorbed dose conversion factors were calculated using Monte Carlo simulations. The difference in the average measured dose to water for the 400 and 1000 MU/min runs using the TG-51 protocol and the GPC was 0.2% and 1.2%, respectively. Heat loss correction factors ranged from 1.001 to 1.002, while the product of the perturbation and dose conversion factors was calculated to be 1.130. The combined relative uncertainty was estimated to be 1.4%, with the largest contributors being the specific heat capacity of the graphite (type B, 0.8%) and the reproducibility, defined as the standard deviation of the mean measured dose (type A, 0.6%). By establishing the feasibility of using the GPC as a practical clinical absolute photon dosimeter, this work lays the foundation for further device enhancements, including the development of an isothermal mode of operation and an overall miniaturization, making it potentially suitable for use in small and composite radiation fields. It is anticipated that, through the incorporation of isothermal stabilization provided by temperature controllers, a subpercent overall uncertainty will be achieved.

Renaud, James; Seuntjens, Jan; Sarfehnia, Arman [Medical Physics Unit, McGill University, Montreal, Quebec H3G 1A4 (Canada); Marchington, David [Ionizing Radiation Standards, National Research Council of Canada, Ottawa, Ontario K1A 0R6 (Canada)

2013-02-15T23:59:59.000Z

69

Graphite Oxidation Simulation in HTR Accident Conditions  

SciTech Connect (OSTI)

Massive air and water ingress, following a pipe break or leak in steam-generator tubes, is a design-basis accident for high-temperature reactors (HTRs). Analysis of these accidents in both prismatic and pebble bed HTRs requires state-of-the-art capability for predictions of: 1) oxidation kinetics, 2) air ?helium gas mixture stratification and diffusion into the core following the depressurization, 3) transport of multi-species gas mixture, and 4) graphite corrosion. This project will develop a multi-dimensional, comprehensive oxidation kinetics model of graphite in HTRs, with diverse capabilities for handling different flow regimes. The chemical kinetics/multi-species transport model for graphite burning and oxidation will account for temperature-related changes in the properties of graphite, oxidants (O2, H2O, CO), reaction products (CO, CO2, H2, CH4) and other gases in the mixture (He and N2). The model will treat the oxidation and corrosion of graphite in geometries representative of HTR core component at temperatures of 900°C or higher. The developed chemical reaction kinetics model will be user-friendly for coupling to full core analysis codes such as MELCOR and RELAP, as well as computational fluid dynamics (CFD) codes such as CD-adapco. The research team will solve governing equations for the multi-dimensional flow and the chemical reactions and kinetics using Simulink, an extension of the MATLAB solver, and will validate and benchmark the model's predictions using reported experimental data. Researchers will develop an interface to couple the validated model to a commercially available CFD fluid flow and thermal-hydraulic model of the reactor , and will perform a simulation of a pipe break in a prismatic core HTR, with the potential for future application to a pebble-bed type HTR.

Mohamed El-Genk

2012-10-19T23:59:59.000Z

70

Conversion of lignin precursors to carbon fibers with nanoscale graphitic domains  

SciTech Connect (OSTI)

Lignin is one of the most abundant and inexpensive natural biopolymers. It can be efficiently converted to low cost carbon fiber, monolithic structures or powders that could be used directly in the production of anodes for lithium-ion batteries. In this work, we report processing parameters relevant for the conversion of lignin precursors into electrochemically active carbon fibers, the impact of lignin precursor modification on melt processing and the microstructure of the final carbon material. The conversion process encompasses melt spinning of the lignin precursor, oxidative stabilization and a low temperature carbonization step in a nitrogen/hydrogen atmosphere. To assess electrochemical performance, we determined resistivities of individual carbon fiber samples and characterized the microstructure by scanning electron microscopy and neutron diffraction. The chemical modification and subsequent thermomechanical processing methods reported here are effective for conversion into carbon fibers while preserving the macromolecular backbone structure of lignin. Modification of softwood lignin produced functionalities and rheological properties that more closely resemble hardwood lignin thereby enabling the melt processing of softwood lignin in oxidative atmospheres (air). Structural characterization of the carbonized fibers reveals nanoscale graphitic domains that are linked to enhanced electrochemical performance.

Chatterjee, Sabornie [ORNL; Jones, Eric B [ORNL; Clingenpeel, Amy [National High Magnetic Field Laboratory (Magnet Lab), Florida; McKenna, Amy [National High Magnetic Field Laboratory (Magnet Lab), Florida; Rios, Orlando [ORNL; McNutt, Nicholas W [ORNL; Keffer, David J. [University of Tennessee, Knoxville (UTK); Johs, Alexander [ORNL

2014-01-01T23:59:59.000Z

71

Raman spectroscopic studies of chemical speciation in calcium chloride melts  

SciTech Connect (OSTI)

Raman spectroscopy was applied to CaCl2 melts at 900 degrees C under both non-electrolyzed and electrolyzed conditions. The later used titania cathodes supplied by TIMET, Inc. and graphite anodes. Use of pulse-gating to collect the Raman spectra successfully eliminated any interference from black-body radiation and other stray light. The spectrum of molten CaCl2 exhibited no distinct, resolvable bands that could be correlated with a calcium chloride complex similar to MgCl42- in MgCl2 melts. Rather, the low frequency region of the spectrum was dominated by a broad “tail” arising from collective oscillations of both charge and mass in the molten salt “network.” Additions of both CaO and Ca at concentrations of a percent or two resulted in no new features in the spectra. Addition of CO2, both chemically and via electrolysis at concentrations dictated by stability and solubility at 900 degrees C and 1 bar pressure, also produced no new bands that could be correlated with either dissolved CO2 or the carbonate ion. These results indicated that Raman spectroscopy, at least under the conditions evaluated in the research, was not well suited for following the reactions and coordination chemistry of calcium ions, nor species such as dissolved metallic Ca and CO2 that are suspected to impact current efficiency in titanium electrolysis cells using molten CaCl2. Raman spectra of TIMET titania electrodes were successfully obtained as a function of temperature up to 900 degrees C, both in air and in-situ in CaCl2 melts. However, spectra of these electrodes could only be obtained when the material was in the unreduced state. When reduced, either with hydrogen or within an electrolysis cell, the resulting electrodes exhibited no measurable Raman bands under the conditions used in this work.

Windisch, Charles F.; Lavender, Curt A.

2005-02-01T23:59:59.000Z

72

Brookhaven Graphite Research Reactor | Environmental Restoration Projects |  

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

Why Was the BGRR Decommissioned? Why Was the BGRR Decommissioned? BGRR The Brookhaven Graphite Research Reactor (BGRR) at Brookhaven National Laboratory (BNL) was decommissioned to ensure the complex is in a safe and stable condition and to reduce sources of groundwater contamination. The BGRR contained over 8,000 Curies of radioactive contaminants from past operations consisting of primarily nuclear activation products such as hydrogen-3 (tritium) and carbon-14 and fission products cesium-137 and strontium-90. The nature and extent of contamination varied by location depending on historic uses of the systems and components and releases, however, the majority of the contamination (over 99 percent) was bound within the graphite pile and biological shield. Radioactive contamination was identified in the fuel handling system deep

73

Facile Sonochemical Synthesis of Graphite Intercalation Compounds  

Science Journals Connector (OSTI)

Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, and Sandia National Laboratories, Albuquerque, New Mexico 87185 ... Similar intercalation of layered inorganic solids has been previously observed using high-intensity ultrasound as the energy source. ... Sonication for a longer period of time produces a blue-black material, which may either be due to partial deintercalation or to the destruction of the intercalated material to reform graphite and potassium. ...

Jess E. Jones; Michael C. Cheshire; Dominick J. Casadonte, Jr.; Carol C. Phifer

2004-05-08T23:59:59.000Z

74

Atomic resolution images of graphite in air  

SciTech Connect (OSTI)

One sample used for proof of operation for atomic resolution in STM is highly oriented pyrolytic graphite (HOPG). This sample has been imaged with many different STM`s obtaining similar results. Atomic resolution images of HOPG have now been obtained using an STM designed and built at the Precision Engineering Center. This paper discusses the theoretical predictions and experimental results obtained in imaging of HOPG.

Grigg, D.A.; Shedd, G.M.; Griffis, D.; Russell, P.E.

1988-12-01T23:59:59.000Z

75

Conference on Foundry Steel Melting  

Science Journals Connector (OSTI)

... British Iron and Steel Research Association held, at Ashorne Hill, near Leamington Spa, a conference devoted to a consideration of recent scientific developments in melting steel in a manner and ... that of supplying bulk steel for ingot manufacture, and it was the object of this conference to discuss these differences with the view of guiding steel founders in the choice of ...

1949-10-22T23:59:59.000Z

76

Nondestructive Evaluation of Nuclear-Grade Graphite  

SciTech Connect (OSTI)

Nondestructive Evaluation of Nuclear Grade Graphite Dennis C. Kunerth and Timothy R. McJunkin Idaho National Laboratory Idaho Falls, ID, 83415 This paper discusses the nondestructive evaluation of nuclear grade graphite performed at the Idaho National Laboratory. Graphite is a composite material highly dependent on the base material and manufacturing methods. As a result, material variations are expected within individual billets as well billet to billet and lot to lot. Several methods of evaluating the material have been explored. Particular technologies each provide a subset of information about the material. This paper focuses on techniques that are applicable to in-service inspection of nuclear energy plant components. Eddy current examination of the available surfaces provides information on potential near surface structural defects and although limited, ultrasonics can be utilized in conventional volumetric inspection. Material condition (e.g. micro-cracking and porosity induced by radiation and stress) can be derived from backscatter or acousto-ultrasound (AU) methods. Novel approaches utilizing phased array ultrasonics have been attempted to expand the abilities of AU techniques. By combining variable placement of apertures, angle and depth of focus, the techniques provide the potential to obtain parameters at various depths in the material. Initial results of the study and possible procedures for application of the techniques are discussed.

Dennis C. Kunerth; Timothy R. McJunkin

2011-07-01T23:59:59.000Z

77

New ideas for the melting pot  

Science Journals Connector (OSTI)

... degrees of the melting point. Pontikis and Sindzingre8 reviewed the tenuous evidence linking this surface roughening of crystals to surface melting and concluded that the two phenomena are probably entirely distinct ...

Robert W. Cahn

1989-12-07T23:59:59.000Z

78

ARM - Lesson Plans: When Land Ice Melts  

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

ice melts? Do you think melting glaciers and other land-based ice masses will make sea level rise? Will it submerge the continents on which the ice used to be? Most of the...

79

Brookhaven Lab Completes Decommissioning of Graphite Research Reactor:  

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

Brookhaven Lab Completes Decommissioning of Graphite Research Brookhaven Lab Completes Decommissioning of Graphite Research Reactor: Reactor core and associated structures successfully removed; waste shipped offsite for disposal Brookhaven Lab Completes Decommissioning of Graphite Research Reactor: Reactor core and associated structures successfully removed; waste shipped offsite for disposal September 1, 2012 - 12:00pm Addthis The Brookhaven Graphite Research Reactor’s bioshield, which contains the 700-ton reactor core, is shown prior to decommissioning. The Brookhaven Graphite Research Reactor's bioshield, which contains the 700-ton reactor core, is shown prior to decommissioning. Pictured here is the Brookhaven Graphite Research Reactor, where major decommissioning milestones were recently reached after the remaining radioactive materials from the facility’s bioshield were shipped to a licensed offsite disposal facility.

80

Immobilization of Rocky Flats Graphite Fines Residues  

SciTech Connect (OSTI)

The Savannah River Technology Center (SRTC) is developing an immobilization process for graphite fines residues generated during nuclear materials production activities at the Rocky Flats Environmental Technology Site (Rocky Flats). The continued storage of this material has been identified as an item of concern. The residue was generated during the cleaning of graphite casting molds and potentially contains reactive plutonium metal. The average residue composition is 73 wt percent graphite, 15 wt percent calcium fluoride (CaF2), and 12 wt percent plutonium oxide (PuO2). Approximately 950 kilograms of this material are currently stored at Rocky Flats. The strategy of the immobilization process is to microencapsulate the residue by mixing with a sodium borosilicate (NBS) glass frit and heating at nominally 700 degrees C. The resulting waste form would be sent to the Waste Isolation Pilot Plant (WIPP) for disposal. Since the PuO2 concentration in the residue averages 12 wt percent, the immobilization process was required to meet the intent of safeguards termination criteria by limiting plutonium recoverability based on a test developed by Rocky Flats. The test required a plutonium recovery of less than 4 g/kg of waste form when a sample was leached using a nitric acid/CaF2 dissolution flowsheet. Immobilization experiments were performed using simulated graphite fines with cerium oxide (CeO2) as a surrogate for PuO2 and with actual graphite fines residues. Small-scale surrogate experiments demonstrated that a 4:1 frit to residue ratio was adequate to prevent recovery of greater than 4 g/kg of cerium from simulated waste forms. Additional experiments investigated the impact of varying concentrations of CaF2 and the temperature/heating time cycle on the cerium recovery. Optimal processing conditions developed during these experiments were subsequently demonstrated at full-scale with surrogate materials and on a smaller scale using actual graphite fines.In general, the recovery of cerium from the full-scale waste forms was higher than for smaller scale experiments. The presence of CaF2 also caused a dramatic increase in cerium recovery not seen in the small-scale experiments. However, the results from experiments with actual graphite fines were encouraging. A 4:1 frit to residue ratio, a temperature of 700 degrees C, and a 2 hr heating time produced waste forms with plutonium recoveries of 4 plus/minus 1 g/kg. With an increase in the frit to residue ratio, waste forms fabricated at this scale should meet the Rocky Flats product specification. The scale-up of the waste form fabrication process to nominally 3 kg is expected to require a 5:1 to 6:1 frit to residue ratio and maintaining the waste form centerline temperature at 700 degrees C for 2 hr.

Rudisill, T. S.

1998-11-06T23:59:59.000Z

Note: This page contains sample records for the topic "melting includes graphite" 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

Splashing and boiling mechanisms of melt layer losses of PFCs during plasma instabilities  

E-Print Network [OSTI]

and computational modeling to predict the effects of viscosity, heat conduction, and phase change on the stability TEXTOR experi- ments have shown constantly present fine melt spray and macro- scopic losses of melt]. In this work, the inviscid stability theory [7­9] is further devel- oped to include the effects of viscosity

Harilal, S. S.

82

Low Cost SiOx-Graphite and Olivine Materials  

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

Sotowa (Showa-Denko) Objective Synthesize and evaluate doped manganese phosphate as low cost cathode material Replace graphite anode with an alternative material that meets the...

83

Low Cost SiOx-Graphite and Olivine Materials  

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

Replace graphite anode with an alternative material that meets the requirement for low cost and high energy. Continue development of binders for the cathode and alternative anode...

84

Binding and Diffusion of Lithium in Graphite: Quantum Monte Carlo...  

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

Binding and Diffusion of Lithium in Graphite: Quantum Monte Carlo Benchmarks and Validation of van der Waals Density Functional Methods P. Ganesh,* , Jeongnim Kim, Changwon...

85

Role of Nuclear Grade Graphite in Oxidation in Modular HTGRs  

SciTech Connect (OSTI)

The passively safe High Temperature Gas-cooled Reactor (HTGR) design is one of the primary concepts considered for Generation IV and Small Modular Reactor (SMR) programs. The helium cooled, nuclear grade graphite moderated core achieves extremely high operating temperatures allowing either industrial process heat or electricity generation at high efficiencies. In addition to their neutron moderating properties, nuclear grade graphite core components provide excellent high temperature stability, thermal conductivity, and chemical compatibility with the high temperature nuclear fuel form. Graphite has been continuously used in nuclear reactors since the 1940’s and has performed remarkably well over a wide range of core environments and operating conditions. Graphite moderated, gas-cooled reactor designs have been safely used for research and power production purposes in multiple countries since the inception of nuclear energy development. However, graphite is a carbonaceous material, and this has generated a persistent concern that the graphite components could actually burn during either normal or accident conditions [ , ]. The common assumption is that graphite, since it is ostensibly similar to charcoal and coal, will burn in a similar manner. While charcoal and coal may have the appearance of graphite, the internal microstructure and impurities within these carbonaceous materials are very different. Volatile species and trapped moisture provide a source of oxygen within coal and charcoal allowing them to burn. The fabrication process used to produce nuclear grade graphite eliminates these oxidation enhancing impurities, creating a dense, highly ordered form of carbon possessing high thermal diffusivity and strongly (covalently) bonded atoms.

Willaim Windes; G. Strydom; J. Kane; R. Smith

2014-11-01T23:59:59.000Z

86

Comparison of gasification kinetics parameters of different types of nuclear graphite  

SciTech Connect (OSTI)

A chemical-reaction kinetics model of nuclear graphite gasification has recently been developed and successfully validated with gasification rate measurements for nuclear graphite grades of IG-110, IG-430, NBG-18 and NBG-25. The model employs 4 elementary chemical reactions with applicable parameters, including the values and Gaussian-like distributions of the specific activation energies, the pre-exponential coefficients for adsorption of oxygen and desorption of CO and CO{sub 2} gases, and the surface area of free active sites. These parameters are determined from the reported measurements of the total gasification and transient weight loss using a multi-parameter optimization algorithm. The determined chemical kinetics parameters for IG-100 and NB-25 are nearly the same, but slightly different from those for NBG-18 and IG-430. The initial specific area of free active sites is inversely proportional to the square root of the mass or volume of the graphite specimens used in experiments. The recommended chemical kinetics parameters in this paper for these grades of nuclear graphite should be applicable to future safety analysis of high-temperature gas cooled reactors in the unlikely event of a massive air ingress accident. (authors)

El-Genk, M. S. [Inst. for Space and Nuclear Power Studies, Univ. of New Mexico, Albuquerque, NM (United States); Chemical and Nuclear Engineering Dept., Univ. of New Mexico, Albuquerque, NM (United States); Mechanical Engineering Dept., Univ. of New Mexico, Albuquerque, NM (United States); Tournier, J. M. P. [Inst. for Space and Nuclear Power Studies, Univ. of New Mexico, Albuquerque, NM (United States); Chemical and Nuclear Engineering Dept., Univ. of New Mexico, Albuquerque, NM (United States)

2012-07-01T23:59:59.000Z

87

Advanced Surface and Microstructural Characterization of Natural Graphite Anodes for Lithium Ion Batteries  

SciTech Connect (OSTI)

Natural graphite powders were subjected to a series of thermal treatments in order to improve the anode irreversible capacity loss (ICL) and capacity retention during long-term cycling of lithium ion batteries. A baseline thermal treatment in inert Ar or N2 atmosphere was compared to cases with a proprietary additive to the furnace gas environment. This additive substantially altered the surface chemistry of the natural graphite powders and resulted in significantly improved long-term cycling performance of the lithium ion batteries over the commercial natural graphite baseline. Different heat-treatment temperatures were investigated ranging from 950-2900 C with the intent of achieving the desired long-term cycling performance with as low of a maximum temperature and thermal budget as possible. A detailed summary of the characterization data is also presented, which includes X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and temperature-programed desorption mass spectroscopy (TPD-MS). This characterization data was correlated to the observed capacity fade improvements over the course of long-term cycling at high charge-discharge rates in full lithium-ion coin cells. It is believed that the long-term performance improvements are a result of forming a more stable solid electrolyte interface (SEI) layer on the anode graphite surfaces, which is directly related to the surface chemistry modifications imparted by the proprietary gas environment during thermal treatment.

Gallego, Nidia C [ORNL] [ORNL; Contescu, Cristian I [ORNL] [ORNL; Meyer III, Harry M [ORNL] [ORNL; Howe, Jane Y [ORNL] [ORNL; Meisner, Roberta Ann [ORNL] [ORNL; Payzant, E Andrew [ORNL] [ORNL; Lance, Michael J [ORNL] [ORNL; Yoon, Steve [A123 Systems, Inc.] [A123 Systems, Inc.; Denlinger, Matthew [A123 Systems, Inc.] [A123 Systems, Inc.; Wood III, David L [ORNL] [ORNL

2014-01-01T23:59:59.000Z

88

Nucleation and growth in electrodeposition of thin copper films on pyrolytic graphite  

SciTech Connect (OSTI)

Electrodeposition of Cu on graphite electrodes was studied, with emphasis on nucleation. Various ex-situ and in-situ methods were investigated for determining the number density of nuclei. Two direct methods were studied (scanning electron microscopy and scanning tunneling microscopy); indirect determinations included Raman spectroscopy and analysis of potentiostatic current transients. Though some of the techniques correctly predicted the nucleation densities under special conditions, SEM was the most reliable tool. The large scatter in the data necessitated steps to minimize this effect. To electrodeposit Cu on graphite, a nucleation overpotential of 250 mV was measured with cyclic voltammetry; such a large overpotential does not occur on a Pt or on a Cu-covered graphite electrode. The deposition potential is the dominant parameter governing nucleation density. There is a sharp increase in the nucleation density with applied potential. Cu can be deposited on highly oriented pyrolytic graphite only between the nucleation overpotential and the hydrogen evolution potential. To increase the Cu nucleation density, while avoiding excessive H evolution, a double pulse potential technique was used; nucleation densities on the order of 10{sup 10} nuclei/cm{sup 2} were achieved. The use of inhibitors (PVA, benzotriazole) was also investigated. Deposition on conducting polymer electrodes was also studied; initial results with polyaniline show promise. 57 figs, 6 tabs, refs. (DLC)

Kinaci, F.S.; Muller, R.H.

1992-05-01T23:59:59.000Z

89

Diffusion Of Hydrophobin Proteins In Solution And Interactions With A Graphite Surface  

SciTech Connect (OSTI)

Background Hydrophobins are small proteins produced by filamentous fungi that have a variety of biological functions including coating of spores and surface adhesion. To accomplish these functions, they rely on unique interface-binding properties. Using atomic-detail implicit solvent rigid-body Brownian dynamics simulations, we studied the diffusion of HFBI, a class II hydrophobin from Trichoderma reesei, in aqueous solution in the presence and absence of a graphite surface. Results In the simulations, HFBI exists in solution as a mixture of monomers in equilibrium with different types of oligomers. The oligomerization state depends on the conformation of HFBI. When a Highly Ordered Pyrolytic Graphite (HOPG) layer is present in the simulated system, HFBI tends to interact with the HOPG layer through a hydrophobic patch on the protein. Conclusions From the simulations of HFBI solutions, we identify a tetrameric encounter complex stabilized by non-polar interactions between the aliphatic residues in the hydrophobic patch on HFBI. After the formation of the encounter complex, a local structural rearrangement at the protein interfaces is required to obtain the tetrameric arrangement seen in HFBI crystals. Simulations performed with the graphite surface show that, due to a combination of a geometric hindrance and the interaction of the aliphatic sidechains with the graphite layer, HFBI proteins tend to accumulate close to the hydrophobic surface.

Mereghetti, Paolo; Wade, Rebecca C.

2011-04-21T23:59:59.000Z

90

Thermodynamics of random copolymer melts  

Science Journals Connector (OSTI)

We report on a mean-field thermodynamic analysis of AB random copolymer melts with (backbone) composition correlations that reflect realistic polymerization conditions. Depending on the strength and sign of these correlations, multiple homogeneous phases, periodic mesophases, or disordered mesophases are possible. We identify an isotropic Lifshitz point and the critical lines that emerge from it. Our results should facilitate the design of new copolymeric materials.

Glenn H. Fredrickson and Scott T. Milner

1991-08-12T23:59:59.000Z

91

Phonon dispersion of graphite by inelastic x-ray scattering * J. Maultzsch,1, E. Dobardzi,2 S. Reich,3 I. Milosevi,2 M. Damnjanovi,2 A. Bosak,4 M. Krisch,4 and  

E-Print Network [OSTI]

quality. It has been partly measured by inelastic neutron scattering INS , electron- energy lossPhonon dispersion of graphite by inelastic x-ray scattering M. Mohr,1, * J. Maultzsch,1, E-plane phonon dispersion of graphite obtained from inelastic x-ray scattering, including the optical

Nabben, Reinhard

92

Low-cost and durable catalyst support for fuel cells: graphite...  

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

cost and durable catalyst support for fuel cells: graphite submicronparticles. Low-cost and durable catalyst support for fuel cells: graphite submicronparticles. Abstract: Low-cost...

93

Evaluation of the Transient Thermal Performance of a Graphite Foam/Phase Change Material Composite.  

E-Print Network [OSTI]

?? The thermal transient response of graphite foam infiltrated with paraffin wax as a thermal protection composite was investigated. Graphite foam is a rigid open-celled… (more)

Trammell, Michael Paul

2013-01-01T23:59:59.000Z

94

Brookhaven Graphite Research Reactor Workshop | Department of Energy  

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

Services » Site & Facility Restoration » Deactivation & Services » Site & Facility Restoration » Deactivation & Decommissioning (D&D) » D&D Workshops » Brookhaven Graphite Research Reactor Workshop Brookhaven Graphite Research Reactor Workshop The Brookhaven Graphite Research Reactor (BGRR) was the first reactor built in the U.S. for peacetime atomic research following World War II. Construction began in 1947 and the reactor started operating in August 1950. In the next 18 years, an estimated 25,000 scientific experiments were carried out at the BGRR using neutrons produced in the facility's 700-ton graphite core, made up of more than 60,000 individual graphite blocks. The BGRR was placed on standby in 1968 and then permanently shut down as the next-generation reactor, the High Flux Beam Reactor (HFBR), was

95

Oxidation of graphite surface: the role of water  

E-Print Network [OSTI]

Based on density functional calculations, we demonstrate a significant difference in oxidation patterns between graphene and graphite and the formation of defects after oxidation. Step-by-step modeling demonstrates that oxidation of 80% of the graphite surface is favorable. Oxidation above half of the graphite surface significantly decreases the energy costs of vacancy formation with CO2 production. The presence of water is crucial in the transformation of epoxy groups to hydroxyl, the intercalation with further bundle and exfoliation. In water-rich conditions, water intercalates graphite at the initial stages of oxidation and oxidation, which is similar to the oxidation process of free-standing graphene; in contrast, in water-free conditions, large molecules intercalate graphite only after oxidation occurs on more than half of the surface.

Boukhvalov, D W

2014-01-01T23:59:59.000Z

96

Graphite and its Hidden Superconductivity | Stanford Synchrotron Radiation  

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

Graphite and its Hidden Superconductivity Graphite and its Hidden Superconductivity Wednesday, November 20, 2013 - 2:00pm SLAC, Conference Room 137-322 Pablo Esquinazi, University of Leipzig We review different experimental results that indicate the existence of granular superconductivity at high temperatures at graphite interfaces. In particular we will discuss the following experimental results: The temperature and magnetic field dependence of the electrical resistance of bulk and thin graphite samples and its relation with the existence of two-dimensional (2D) interfaces. The anomalous hysteresis in the magnetoresistance observed in graphite thin samples as well as its enhancement restricting the current path within the sample. The Josephson behavior of the current-voltage characteristics with

97

Treatment of Irradiated Graphite to meet Acceptance Criteria for Waste Disposal: A New IAEA Collaborative Research Program - 12443  

SciTech Connect (OSTI)

World-wide, more than 250,000 tonnes of irradiated graphite have arisen through commercial nuclear-power operations and from military production reactors. Whilst most nations responsible for the generation of this material have in mind repository disposal alongside other radwaste, the lack of progress in this regard has led in some cases to difficulties where, for example, the site of an existing graphite-moderated reactor is required for re-utilisation. In any case, graphite as a radwaste stream has unique chemical and physical properties which may lend itself to more radical and innovative treatment and disposal options, including the recovery of useful isotopes and also recycling within the nuclear industry. Such aspects are important in making the case for future graphite-moderated reactor options (for example, High-Temperature Reactors planned for simultaneous power production and high-grade heat sources for such applications as hydrogen production for road fuel). A number of initiatives have taken place since the mid 1990s aimed at exploring such alternative strategies and, more recently, improving technology offers new options at all stages of the dismantling and disposal process. A new IAEA Collaborative Research Program aims to build upon the work already done and the knowledge achieved, in order to identify the risks and uncertainties associated with alternative options for graphite disposal, along with cost comparisons, thus enabling individual Member States to have the best-available information at their disposal to configure their own programs. (authors)

Wickham, A.J. [Nuclear Technology Consultancy, PO Box 50, Builth Wells, Powys LD2 3XA (United Kingdom); Drace, Z. [Waste Technology Section, Division of Nuclear Fuel Cycle and Waste Technology, International Atomic Energy Agency, Wagramerstrasse 5, PO Box 100, A-1400, Vienna (Austria)

2012-07-01T23:59:59.000Z

98

Pump apparatus including deconsolidator  

DOE Patents [OSTI]

A pump apparatus includes a particulate pump that defines a passage that extends from an inlet to an outlet. A duct is in flow communication with the outlet. The duct includes a deconsolidator configured to fragment particle agglomerates received from the passage.

Sonwane, Chandrashekhar; Saunders, Timothy; Fitzsimmons, Mark Andrew

2014-10-07T23:59:59.000Z

99

MEASUREMENT OF THE SHOCK-HEATED MELT CURVE OF LEAD USING PYROMETRY AND REFLECTOMETRY  

SciTech Connect (OSTI)

Data on the high-pressure melting temperatures of metals is of great interest in several fields of physics including geophysics. Measuring melt curves is difficult but can be performed in static experiments (with laser-heated diamond-anvil cells for instance) or dynamically (i.e., using shock experiments). However, at the present time, both experimental and theoretical results for the melt curve of lead are at too much variance to be considered definitive. As a result, we decided to perform a series of shock experiments designed to provide a measurement of the melt curve of lead up to about 50 GPa in pressure. At the same time, we developed and fielded a new reflectivity diagnostic, using it to make measurements on tin. The results show that the melt curve of lead is somewhat higher than the one previously obtained with static compression and heating techniques.

D. Partouche-Sebban and J. L. Pelissier, Commissariat a` l'Energie Atomique,; F. G. Abeyta, Los Alamos National Laboratory; W. W. Anderson, Los Alamos National Laboratory; M. E. Byers, Los Alamos National Laboratory; D. Dennis-Koller, Los Alamos National Laboratory; J. S. Esparza, Los Alamos National Laboratory; S. D. Borror, Bechtel Nevada; C. A. Kruschwitz, Bechtel Nevada

2004-01-01T23:59:59.000Z

100

(Fuel, fission product, and graphite technology)  

SciTech Connect (OSTI)

Travel to the Forschungszentrum (KFA) -- Juelich described in this report was for the purpose of participating in the annual meeting of subprogram managers for the US/DOE Umbrella Agreement for Fuel, Fission Product, and Graphite Technology. At this meeting the highlights of the cooperative exchange were reviewed for the time period June 1989 through June 1990. The program continues to contribute technology in an effective way for both countries. Revision 15 of the Subprogram Plan will be issued as a result of the meeting. There was interest expressed by KFA management in the level of support received from the NPR program and in potential participation in the COMEDIE loop experiment being conducted at the CEA.

Stansfield, O.M.

1990-07-25T23:59:59.000Z

Note: This page contains sample records for the topic "melting includes graphite" 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

Brookhaven Graphite Research Reactor | Environmental Restoration Projects |  

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

- Cleanup Actions - Cleanup Actions Since the Brookhaven Graphite Research Reactor (BGRR) was shut down in 1968, many actions have been taken as part of the complex decommissioning. The actions undertaken throughout the BGRR complex ensure that the structures that remain are in a safe and stable condition and prepared it for long-term surveillance and maintenance. Regulatory Requirements The decommissioning of the BGRR was conducted under the federal Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). In 1992, an Interagency Agreement (PDF) among the DOE, the U.S. Environmental Protection Agency (EPA) and the New York State Department of Environmental Conservation (NYSDEC) became effective. The IAG provided the overall framework for conducting environmental restoration activities at

102

Plasma Sprayed Pour Tubes and Other Melt Handling Components for Use in Gas Atomization  

SciTech Connect (OSTI)

Ames Laboratory has successfully used plasma sprayed ceramic components made from yttria stabilized zirconia as melt pouring tubes for gas atomization for many years. These tubes have proven to be strong, thermal shock resistant and versatile. Various configurations are possible both internally and externally. Accurate dimensions are achieved internally with a machined fugitive graphite mandrel and externally by diamond grinding. The previous study of the effect of spray parameters on density was extended to determine the effect of the resulting density on the thermal shock characteristics on down-quenching and up-quenching. Encouraging results also prompted investigation of the use of plasma spraying as a method to construct a melt pour exit stopper that is mechanically robust, thermal shock resistant, and not susceptible to attack by reactive melt additions. The Ames Laboratory operates two close-coupled high pressure gas atomizers. These two atomizers are designed to produce fine and coarse spherical metal powders (5{mu} to 500{mu} diameter) of many different metals and alloys. The systems vary in size, but generally the smaller atomizer can produce up to 5 kg of powder whereas the larger can produce up to 25 kg depending on the charge form and density. In order to make powders of such varying compositions, it is necessary to have melt systems capable of heating and containing the liquid charge to the desired superheat temperature prior to pouring through the atomization nozzle. For some metals and alloys this is not a problem; however for some more reactive and/or high melting materials this can pose unique challenges. Figure 1 is a schematic that illustrates the atomization system and its components.

Byrd, David; Rieken, Joel; Heidloff, Andy; Besser, Matthew; Anderson, Iver

2011-04-01T23:59:59.000Z

103

Comparison of Cycling Performance of Lithium Ion Cell Anode Graphites  

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

Comparison of Cycling Performance of Lithium Ion Cell Anode Graphites Comparison of Cycling Performance of Lithium Ion Cell Anode Graphites Title Comparison of Cycling Performance of Lithium Ion Cell Anode Graphites Publication Type Journal Article Year of Publication 2012 Authors Ridgway, Paul L., Honghe Zheng, A. F. Bello, Xiangyun Song, Shidi Xun, Jin Chong, and Vincent S. Battaglia Journal Journal of The Electrochemical Society Volume 159 Issue 5 Pagination A520 Date Published 2012 ISSN 00134651 Abstract Battery grade graphite products from major suppliers to the battery industry were evaluated in 2325 coin cells with lithium counter electrodes. First and ongoing cycle efficiency, total and reversible capacity, cycle life and discharge rate performance were measured to compare these anode materials. We then ranked the graphites using a formula which incorporates these performance measures to estimate the cost of the overall system, relative to the cost of a system using MCMB. This analysis indicates that replacing MCMB with CCP-G8 (Conoco Phillips) would add little to no cost, whereas each of the other graphites would lead to a more costly system. Therefore we chose CCP-G8 as the new baseline graphite for the BATT program.

104

Safety evaluation for packaging (onsite) plutonium recycle test reactor graphite cask  

SciTech Connect (OSTI)

This safety evaluation for packaging (SEP) provides the evaluation necessary to demonstrate that the Plutonium Recycle Test Reactor (PRTR) Graphite Cask meets the requirements of WHC-CM-2-14, Hazardous Material Packaging and Shipping, for transfer of Type B, fissile, non-highway route controlled quantities of radioactive material within the 300 Area of the Hanford Site. The scope of this SEP includes risk, shieldling, criticality, and.tiedown analyses to demonstrate that onsite transportation safety requirements are satisfied. This SEP also establishes operational and maintenance guidelines to ensure that transport of the PRTR Graphite Cask is performed safely in accordance with WHC-CM-2-14. This SEP is valid until October 1, 1999. After this date, an update or upgrade to this document is required.

Romano, T.

1997-09-29T23:59:59.000Z

105

Importance of the ‘shape' of the melting regime during partial melting of the mantle  

Science Journals Connector (OSTI)

... been modelled using the familiar relationship2 for the composition of a perfect fractional partial melt (PFPM).

M. J. O'Hara

1985-03-07T23:59:59.000Z

106

The viscosity of polymer melts  

Science Journals Connector (OSTI)

A simple theoretical argument is presented that gives the scaling behavior of the relaxation time in a polymer melt as a function of molecular weight M. The framework for this theory is based on the reptation model of de Gennes but also incorporates the effects of excluded volume. It is argued that the effects of excluded volume change the relaxation time from M 3 to M 3 exp(const×M 2/3). This argument agrees qualitatively with a direct simulation of the reptation model that incorporates many?chain excluded volume interactions. This simulation fits experimental data quite well giving an effective power law relationship between viscosity ? and molecular weight namely ??M 3.4±.1.

J. M. Deutsch

1986-01-01T23:59:59.000Z

107

Status of the NGNP Graphite Creep Experiments AGC-1 and AGC-2 Irradiated in the Advanced Test Reactor  

SciTech Connect (OSTI)

The United States Department of Energy’s Next Generation Nuclear Plant (NGNP) Program will be irradiating six nuclear graphite creep experiments in the Advanced Test Reactor (ATR) located at the Idaho National Laboratory (INL). The graphite experiments will be irradiated over the next six to eight years to support development of a graphite irradiation performance data base on the new nuclear grade graphites now available for use in high temperature gas reactors. The goals of the irradiation experiments are to obtain irradiation performance data, including irradiation creep, at different temperatures and loading conditions to support design of the Next Generation Nuclear Plant (NGNP) Very High Temperature Gas Reactor, as well as other future gas reactors. The experiments will each consist of a single capsule that will contain six peripheral stacks of graphite specimens, with half of the graphite specimens in each stack under a compressive load, while the other half of the specimens will not be subjected to a compressive load during irradiation. The six peripheral stacks will have different compressive loads applied to the top half of each pair of specimen stacks, while a seventh stack will not have a compressive load. The specimens will be irradiated in an inert sweep gas atmosphere with on-line temperature and compressive load monitoring and control. There will also be sampling the sweep gas effluent to determine if any oxidation or off-gassing of the specimens occurs during irradiation of the experiment. The first experiment, AGC-1, started its irradiation in September 2009, and the irradiation was completed in January 2011. The second experiment, AGC-2, started its irradiation in April 2011 and completed its irradiation in May 2012. This paper will briefly discuss the design of the experiment and control systems, and then present the irradiation results for each experiment to date.

Blaine Grover

2012-10-01T23:59:59.000Z

108

Non-graphite crucible for high temperature applications  

DOE Patents [OSTI]

A multi-piece crucible for high temperature applications comprises a tubular side wall member having a lip on the inside surface and a bottom member or members forming a container for containing a melt of a material during a high temperature melt-casting operations. The multi-piece design prevents cracking of the crucible or leakage of the melt from the crucible during the melt-casting operation. The lip of the tubular member supports the bottom member. The contacting surfaces where the lip of the tubular side wall member contacts the bottom member of the multi-piece crucible contains a ceramic sealing material. The ceramic sealing material forms a seal sufficient to prevent the melt of the material from leaking out of the multi-piece crucible during the melt-casting process. The multi-piece crucible is made of a material which is chemically inert to the melt and has structural integrity at the melting point temperature of the melt, or of a material coated with such a material. The multi-piece crucible is contained in a thermal can assembly of a high temperature induction furnace during a high temperature melt-casting operation. One embodiment of the multi-piece crucible comprises a tubular member having a vertical slot filled with a ceramic sealing material to provide expansion of the tubular member without cracking during the high temperature melt-casting operation. 9 figs.

Holcombe, C.E.; Pfeiler, W.A.

1996-01-09T23:59:59.000Z

109

Molecular dynamics of LiF melting  

Science Journals Connector (OSTI)

We performed molecular-dynamics simulations of the melting and/or freezing of LiF. The simulations were done using the Tosi-Fumi model and our own model of interatomic interactions. The latter was verified by ab initio calculations of the equation of state for LiF. We show that the recent molecular-dynamics calculations by Boehler and co-workers are not adequate and their model for the interactions is not capable of providing melting temperatures in agreement with experiment. Our calculated pressure dependence of the melting temperatures gives valuable information. We found that the B1-B2 transition in LiF at around 1 Mbar removes the discrepancy between the diamond-anvil cell and shockwave melting temperatures. An explanation of the controversy between “low” and “high” melting temperatures obtained from diamond-anvil cell experiments is suggested.

A. B. Belonoshko; R. Ahuja; B. Johansson

2000-05-01T23:59:59.000Z

110

Experimental thermal conductivity and contact conductance of graphite composites  

E-Print Network [OSTI]

Graphite fiber organic matrix composites were reviewed ics. for potential heat sink applications in the electronics packaging determined the effective transverse and longitudinal thermal industry. This experimental investigation conductivity...

Jackson, Marian Christine

2012-06-07T23:59:59.000Z

111

An Investigation of the effect of graphite degradation on irreversible  

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

An Investigation of the effect of graphite degradation on irreversible An Investigation of the effect of graphite degradation on irreversible capacity in lithium-ion cells. Title An Investigation of the effect of graphite degradation on irreversible capacity in lithium-ion cells. Publication Type Journal Article Year of Publication 2008 Authors Hardwick, Laurence J., Marek Marcinek, Leanne Beer, John B. Kerr, and Robert Kostecki Journal Electrochemical Society Volume 155 Start Page A442 Issue 6 Pagination A442-A447 Keywords chromatography, electrochemical electrodes, electrochemical impedance spectroscopy, Fourier transform spectra, graphite, infrared spectra, lithium, mass spectra, Raman spectra, scanning electron microscopy, secondary cells, sputtering, surface structure Abstract The effect of surface structural damage on graphitic anodes, commonly observed in tested Li-ion cells, was investigated. Similar surface structural disorder was artificially induced in Mag-10 synthetic graphite anodes using argon-ion sputtering. Raman microscopy, scanning electron microscopy, and Brunauer-Emmett-Teller measurements confirmed that Ar-ion sputtered Mag-10 electrodes display a similar degree of surface degradation as the anodes from tested Li-ion cells. Artificially modified Mag-10 anodes showed double the irreversible charge capacity during the first formation cycle compared to fresh unaltered anodes. Impedance spectroscopy and Fourier transform infrared spectroscopy on surface-modified graphite anodes indicated the formation of a thicker and slightly more resistive solid electrolyte interphase (SEI) layer. Gas chromatography/mass spectroscopy analysis of solvent extracts from the electrodes detected the presence of new compounds with Mw on the order of 1600gmol-1 for the surface-modified electrode with no evidence of elevated Mw species for the unmodified electrode. The structural disorder induced in the graphite during long-term cycling may be responsible for the slow and continuous SEI layer reformation, and consequently, the loss of reversible capacity due to the shift of lithium inventory in cycled Li-ion cells.

112

GUM Analysis for TIMS and SIMS Isotopic Ratios in Graphite  

SciTech Connect (OSTI)

This report describes GUM calculations for TIMS and SIMS isotopic ratio measurements of reactor graphite samples. These isotopic ratios are used to estimate reactor burn-up, and currently consist of various ratios of U, Pu, and Boron impurities in the graphite samples. The GUM calculation is a propagation of error methodology that assigns uncertainties (in the form of standard error and confidence bound) to the final estimates.

Heasler, Patrick G.; Gerlach, David C.; Cliff, John B.; Petersen, Steven L.

2007-04-01T23:59:59.000Z

113

Compression induced delamination in a unidirectional graphite/epoxy composite  

E-Print Network [OSTI]

December 1981 Major Subject: Civil Engineering COMPRESSION INDUCED DELAMINATION IN A UNIDIRECTIONAL GRAPHITE/EPOXY COMPOSITE A Thesis by JOHN W. EARLEY Approved as to style and content by: (K. L. Jerina, Chairman) (R, A. Schape y', MemP ) W. L.... Bradley, Me er Il. 8 0 1d, O. pa t~tH d December 1981 ABSTRACT Compression Induced Delamination in a Unidirectional Graphite/Epoxy Composite (December 1981) John William Earley, B. S. Aeronautical Engineering California Polytechnic State University...

Earley, John W.

2012-06-07T23:59:59.000Z

114

An investigation of damage accumulation in graphite/epoxy laminates  

E-Print Network [OSTI]

AN INVESTIGATION OF DAMAGE ACCUMULATION IN GRAPHITE/EPOXY LAMINATES A Thesis by ROBERT GERALD NORVELL Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE... August 1985 Major Subject: Aerospace Engineering AN INVESTIGATION OF DAMAGE ACCUMULATION IN GRAPHITE/EPOXY LAMINATES A Thesis by ROBERT GERALD NORVELL Approved as to style and content by: David H. Allen (Co-Chair of C mmitt. ) Richard A. Schap...

Norvell, Robert Gerald

2012-06-07T23:59:59.000Z

115

Slow, stable delamination in graphite/epoxy composites  

E-Print Network [OSTI]

SLOB, STABLE DELAFIINATION IN GRAPHITE/EPOXY COMPOSITES A Thesis by HAMID RA2I Submitted to the Graduate College of Texas ASM University in partial fulfillment of the reouirement for the degree of MASTER OF SCIENCE December 1982 Major... Subject: Mechanical Engineering SLOW, STABLE DELAMINATION IN GRAPHITE/EPOXY COMPOSITES A Thesis by HAMID RAZI Approved as to style and content by: (R. A. Schapery, hair (J. R. Wa ton, Member) (W. L. Bradley, Membe . R. Hopkins, ead of Department...

Razi, Hamid

2012-06-07T23:59:59.000Z

116

Optimized Operating Range for Large-Format LiFePO4/Graphite Batteries  

SciTech Connect (OSTI)

e investigated the long-term cycling performance of large format 20Ah LiFePO4/graphite batteries when they are cycled in various state-of-charge (SOC) ranges. It is found that batteries cycled in the medium SOC range (ca. 20~80% SOC) exhibit superior cycling stability than batteries cycled at both ends (0-20% or 80-100%) of the SOC even though the capcity utilized in the medium SOC range is three times as large as those cycled at both ends of the SOC. Several non-destructive techniques, including a voltage interruption approach, model-based parameter identification, electrode impedance spectra analysis, ?Q/?V analysis, and entropy change test, were used to investigate the performance of LiFePO4/graphite batteries within different SOC ranges. The results reveal that batteries at the ends of SOC exhibit much higher polarization impedance than those at the medium SOC range. These results can be attributed to the significant structural change of cathode and anode materials as revealed by the large entropy change within these ranges. The direct correlation between the polarization impedance and the cycle life of the batteries provides an effective methodology for battery management systems to control and prolong the cycle life of LiFePO4/graphite and other batteries.

Jiang, Jiuchun; Shi, Wei; Zheng, Jianming; Zuo, Pengjian; Xiao, Jie; Chen, Xilin; Xu, Wu; Zhang, Jiguang

2014-06-01T23:59:59.000Z

117

Coal precursors for production of carbon and graphite products. Final report  

SciTech Connect (OSTI)

The main goal of this program was to demonstrate the utility of coal extracts from the West Virginia University (WVU) extraction process as suitable base raw materials for the carbon products encompassed by the Carbon Products Consortium (CPC) team. These include binder and impregnation pitches, Coke for graphite electrodes, Cokes for anodes and specialty graphite, matrices for C/C composites and raw material for mesophase pitch fibers. Previous work in this program has shown that the WVU coal extraction process coupled with hydrotreatment, does have the potential for achieving this objective. The current effort involved screening and evaluation of extracts produced by the WVU Group and recommending appropriate materials for scaleup for subsequent evaluation by Consortium Team members. The program involved an initial characterization of small-scale extracts using standard analytical methods and mesophase formation studies. This was followed by feedback to the WVU Group and to the CPC partners with recommendation of material for scaleup. Similar analytical and mesophase studies on some of the scaled-up extracts was performed. The activation of the coal extraction residues for the purpose of producing a useful active carbon was investigated. A further task was to fabricate a small graphite artifact using Coke derived from coal extract as the filler and the coal extract itself as a binder. The results of the studies are summarized in this report.

Lewis, I.C.; Lewis, R.T.; Mayer, H.K. [Ucar Carbon Co., Inc., Parma, OH (United States)

1996-04-08T23:59:59.000Z

118

Effect of Vinylene Carbonate on Graphite Anode Cycling Efficiency  

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

Effect of Vinylene Carbonate on Graphite Anode Cycling Efficiency Effect of Vinylene Carbonate on Graphite Anode Cycling Efficiency Title Effect of Vinylene Carbonate on Graphite Anode Cycling Efficiency Publication Type Journal Article Year of Publication 2009 Authors Ridgway, Paul L., Honghe Zheng, Xiangyun Song, Gao Liu, Philip N. Ross, and Vincent S. Battaglia Journal Electrochemical Society Volume 19 Start Page 51 Issue 25 Pagination 51-57 Abstract Vinylene Carbonate (VC) was added to the electrolyte in graphite-lithium half-cells. We report its effect on the coulombic efficiency (as capacity shift) of graphite electrodes under various formation cycling conditions. Cyclic voltammetry on glassy carbon showed that VC passivates the electrode against electrolyte reduction. The dQ/dV plots of the first lithiation of the graphite suggest that VC alters the SEI layer, and that by varying the cell formation rate, the initial ratio of ethylene carbonate to VC in the SEI layer can be controlled. VC was found to decrease first cycle efficiency and reversible capacity (in ongoing cycling) when used to excess. However, experiments with VC additive used with various formation rates did not show any decrease in capacity shift.

119

Energy-Efficient Melting and Direct Delivery of High Quality...  

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

Energy-Efficient Melting and Direct Delivery of High Quality Molten Aluminum Energy-Efficient Melting and Direct Delivery of High Quality Molten Aluminum itmdelivery.pdf More...

120

ITP Metal Casting: Advanced Melting Technologies: Energy Saving...  

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

Advanced Melting Technologies: Energy Saving Concepts and Opportunities for the Metal Casting Industry ITP Metal Casting: Advanced Melting Technologies: Energy Saving Concepts and...

Note: This page contains sample records for the topic "melting includes graphite" 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.


121

Melting of superheated crystals initiates on vacancies  

E-Print Network [OSTI]

In a large variety of ideal crystals we found that when rapidly migrating atoms squash or annihilate a neighbouring vacancy and produce a disordered cluster, the heat of migration stored in the system exceeds the enthalpy increase required for the coordinating atoms of the vacancy to form a liquid phase, i.e. the liquid phase nucleates from vacancies. Furthermore volumetric analysis supports this well. This vacancy-decomposition model provides quantitative information on the melting point, the latent heat and the volume change upon melting and hence clarifies the mechanism of melting.

L. W. Wang; Q. Wang; K. Q. Lu

2010-07-24T23:59:59.000Z

122

Numerical and experimental investigation of melting with internal heat generation within cylindrical enclosures  

SciTech Connect (OSTI)

There have been significant efforts by the heat transfer community to investigate the melting phenomenon of materials. These efforts have included the analytical development of equations to represent melting, numerical development of computer codes to assist in modeling the phenomena, and collection of experimental data. The understanding of the melting phenomenon has application in several areas of interest, for example, the melting of a Phase Change Material (PCM) used as a thermal storage medium as well as the melting of the fuel bundle in a nuclear power plant during an accident scenario. The objective of this research is two-fold. First a numerical investigation, using computational fluid dynamics (CFD), of melting with internal heat generation for a vertical cylindrical geometry is presented. Second, to the best of authors knowledge, there are very limited number of engineering experimental results available for the case of melting with Internal Heat Generation (IHG). An experiment was performed to produce such data using resistive, or Joule, heating as the IHG mechanism. The numerical results are compared against the experimental results and showed favorable correlation. Uncertainties in the numerical and experimental analysis are discussed. Based on the numerical and experimental analysis, recommendations are made for future work.

Amber Shrivastava; Brian Williams; Ali S. Siahpush; Bruce Savage; John Crepeau

2014-06-01T23:59:59.000Z

123

Draft report on melt point as a function of composition for urania-based systems  

SciTech Connect (OSTI)

This report documents the testing of a urania (UO{sub 2.00}) sample as a baseline and the attempt to determine the melt point associated with 4 compositions of urania-ceria and urania-neodymia pseudo binaries provided by ORNL, with compositions of 95/5, and 80/20 and of (U/Ce)O{sub 2.00} and (U/Nd)O{sub 2.00} in the newly developed ceramic melt point determination system. A redesign of the system using parts fabricated from tungsten was undertaken in order to help prevent contamination and tungsten carbide formation in the crucibles. The previously developed system employed mostly graphite parts that were shown to react with the sample containment black-body crucible leading to unstable temperature readings and crucible failure, thus the redesign. Measured melt point values of UO{sub 2.00} and U{sub 0.95}Ce{sub 0.05}O{sub 2.00}, U{sub 0.80}Ce{sub 0.20}O{sub 2.00}, U{sub 0.95}Nd{sub 0.05}O{sub 2.00} and U{sub 0.80}Nd{sub 0.20}O{sub 2.00} were measured using a 2-color pyrometer. The value measured for UO{sub 2.00} was consistent with the published accepted value 2845 C {+-} 25 C, although a wide range of values has been published by researchers and will be discussed later in the text. For comparison, values obtained from a published binary phase diagram of UO{sub 2}-Nd{sub 2}O{sub 3} were used for comparison with our measure values. No literature melt point values for comparison with the measurements performed in this study were found for (U/Ce)O{sub 2.00} in our stoichiometry range.

Valdez, James A [Los Alamos National Laboratory; Byler, Darrin D [Los Alamos National Laboratory

2012-06-08T23:59:59.000Z

124

Energy Saving Melting and Revert Reduction Technology (E-SMARRT): Melting Efficiency Improvement  

SciTech Connect (OSTI)

Steel foundries melt recycled scrap in electric furnaces and typically consume 35-100% excess energy from the theoretical energy requirement required to pour metal castings. This excess melting energy is multiplied by yield losses during casting and finishing operations resulting in the embodied energy in a cast product typically being three to six times the theoretical energy requirement. The purpose of this research project was to study steel foundry melting operations to understand energy use and requirements for casting operations, define variations in energy consumption, determine technologies and practices that are successful in reducing melting energy and develop new melting techniques and tools to improve the energy efficiency of melting in steel foundry operations.

Principal Investigator Kent Peaslee; Co-PIĂƒ ƒ Ă‚ Â˘Ăƒ ‚ Ă‚ € Ăƒ ‚ Ă‚ ™ s: Von Richards, Jeffrey Smith

2012-07-31T23:59:59.000Z

125

Lamellar Crystallization and Melting of Polyoxymethylene  

Science Journals Connector (OSTI)

Polyoxymethylene has been crystallized isothermally from the melt and from solution and has been analyzed for the lamellar fold period as related to the melting behavior. The melt?crystallized samples gave intense low?angle x?ray and DTA peaks and in addition produced weak x?ray reflections and shoulders on the DTA melting peaks. The strong peaks yielded Tm 0(s)=210±10°C and two independent methods of calculating ? e (s) place its value at 150 erg/cm2 with a maximum variation of ±40 erg/cm2. A method of plotting the data is proposed which allows a determination of ? from the experimental data of about 14 erg/cm2. The weak peaks although not as accurate as the strong ones yielded Tm 0(w)=182°±2°C and ? e (w)=37±10 erg/cm2.

D. R. Carter; Eric Baer

1966-01-01T23:59:59.000Z

126

Metal melting for volume reduction and recycle  

SciTech Connect (OSTI)

This paper summarizes the experiences with melting contaminated steel materials for volume reduction and melting uranium-contaminated copper and aluminum for possible recycle. In the past there has not been an economic incentive to reduce the volume of low-level beta-gamma contaminated metallic scrap materials in the United States. With the rising cost of transportation and burial facility fees new interest in volume reduction is being generated. This new interest has been primarily focused at the Idaho National Engineering Laboratory (INEL) where the Waste Experimental Reduction Facility (WERF) was established to demonstrate both metal melting and incineration of combustible material for volume reduction. Other demonstration programs involving melting for volume reduction and recycle of aluminum and copper, as well as ferrous scrap, were related to the Cascade Improvement and Cascade Upgrade Programs (CIP/CUP) at the Paducah, Kentucky facility. While the melting demonstrations for the CIP/CUP material were not primarily based on economic incentives, several observations recorded during the programs are of interest with regard to melting of copper and aluminum. (4 refs., 8 tabs.)

Miller, R.L.

1987-03-27T23:59:59.000Z

127

Treatment of Irradiated Graphite from French Bugey Reactor - 13424  

SciTech Connect (OSTI)

Beginning in 2009, in order to determine an alternative to direct disposal for decommissioned irradiated graphite from EDF's Bugey NPP, Studsvik and EDF began a test program to determine if graphite decontamination and destruction were practicable using Studsvik's thermal organic reduction (THOR) technology. The testing program focused primarily on the release of C-14, H-3, and Cl-36 and also monitored graphite mass loss. For said testing, a bench-scale steam reformer (BSSR) was constructed with the capability of flowing various compositions of gases at temperatures up to 1300 deg. C over uniformly sized particles of graphite for fixed amounts of time. The BSSR was followed by a condenser, thermal oxidizer, and NaOH bubbler system designed to capture H-3 and C-14. Also, in a separate series of testing, high concentration acid and peroxide solutions were used to soak the graphite and leach out and measure Cl-36. A series of gasification tests were performed to scope gas compositions and temperatures for graphite gasification using steam and oxygen. Results suggested higher temperature steam (1100 deg. C vs. 900 deg. C) yielded a practicable gasification rate but that lower temperature (900 deg. C) gasification was also a practicable treatment alternative if oxygen is fed into the process. A series of decontamination tests were performed to determine the release behavior of and extent to which C-14 and H-3 were released from graphite in a high temperature (900-1300 deg. C), low flow roasting gas environment. In general, testing determined that higher temperatures and longer roasting times were efficacious for releasing H-3 completely and the majority (80%) of C-14. Manipulating oxidizing and reducing gas environments was also found to limit graphite mass loss. A series of soaking tests was performed to measure the amount of Cl-36 in the samples of graphite before and after roasting in the BSSR. Similar to C-14 release, these soaking tests revealed that 70-80% Cl-36 is released during roasting tests. (authors)

Brown, Thomas [Studsvik, Inc., 5605 Glenridge Drive NE, Suite 705, Atlanta, GA (United States)] [Studsvik, Inc., 5605 Glenridge Drive NE, Suite 705, Atlanta, GA (United States); Poncet, Bernard [electricite de France, 154 Avenue Thiers, CS 60018, 69458 Lyon Cedex 06 (France)] [electricite de France, 154 Avenue Thiers, CS 60018, 69458 Lyon Cedex 06 (France)

2013-07-01T23:59:59.000Z

128

First Direct Evidence of Dirac Fermions in Graphite  

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

Direct Evidence of Dirac Fermions in Graphite Print Direct Evidence of Dirac Fermions in Graphite Print The recent surge of interest in the electronic properties of graphene-that is, isolated layers of graphite just one atomic layer thick-has largely been driven by the discovery that electron mobility in graphene is ten times higher than in commercial-grade silicon, raising the possibility of high-efficiency, low-power, carbon-based electronics. Scientists attribute graphene's surprising current capacity (as well as a number of even stranger phenomena) to the presence of charge carriers that behave as if they are massless, "relativistic" quasiparticles called Dirac fermions. Harnessing these quasiparticles in real-world carbon-based devices, however, requires a deeper knowledge of their behavior under less-than-ideal circumstances, such as around defects, at edges, or in three dimensions-in other words, in graphite. At the ALS, a team of researchers using angle-resolved photoemission spectroscopy (ARPES) have now produced the first direct evidence of massless Dirac fermions in graphite coexisting with quasiparticles of finite effective mass and defect-induced localized states.

129

First Direct Evidence of Dirac Fermions in Graphite  

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

Direct Evidence of Dirac Fermions in Graphite Print Direct Evidence of Dirac Fermions in Graphite Print The recent surge of interest in the electronic properties of graphene-that is, isolated layers of graphite just one atomic layer thick-has largely been driven by the discovery that electron mobility in graphene is ten times higher than in commercial-grade silicon, raising the possibility of high-efficiency, low-power, carbon-based electronics. Scientists attribute graphene's surprising current capacity (as well as a number of even stranger phenomena) to the presence of charge carriers that behave as if they are massless, "relativistic" quasiparticles called Dirac fermions. Harnessing these quasiparticles in real-world carbon-based devices, however, requires a deeper knowledge of their behavior under less-than-ideal circumstances, such as around defects, at edges, or in three dimensions-in other words, in graphite. At the ALS, a team of researchers using angle-resolved photoemission spectroscopy (ARPES) have now produced the first direct evidence of massless Dirac fermions in graphite coexisting with quasiparticles of finite effective mass and defect-induced localized states.

130

First Direct Evidence of Dirac Fermions in Graphite  

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

Direct Evidence of Dirac Direct Evidence of Dirac Fermions in Graphite First Direct Evidence of Dirac Fermions in Graphite Print Wednesday, 27 June 2007 00:00 The recent surge of interest in the electronic properties of graphene-that is, isolated layers of graphite just one atomic layer thick-has largely been driven by the discovery that electron mobility in graphene is ten times higher than in commercial-grade silicon, raising the possibility of high-efficiency, low-power, carbon-based electronics. Scientists attribute graphene's surprising current capacity (as well as a number of even stranger phenomena) to the presence of charge carriers that behave as if they are massless, "relativistic" quasiparticles called Dirac fermions. Harnessing these quasiparticles in real-world carbon-based devices, however, requires a deeper knowledge of their behavior under less-than-ideal circumstances, such as around defects, at edges, or in three dimensions-in other words, in graphite. At the ALS, a team of researchers using angle-resolved photoemission spectroscopy (ARPES) have now produced the first direct evidence of massless Dirac fermions in graphite coexisting with quasiparticles of finite effective mass and defect-induced localized states.

131

Effect of microstructure on air oxidation resistance of nuclear graphite  

SciTech Connect (OSTI)

Oxidation resistance in air of three grades of nuclear graphite with different structures was compared using a standard thermogravimetric method. Differences in the oxidation behavior have been identified with respect to both (i) the rate of oxidation in identical conditions and the derived apparent activation energy and pre-exponential factor and (ii) the penetration depth of the oxidant and the development of the oxidized layer. These differences were ascribed to structural differences between the three graphite grades, in particular the grain size and shape of the graphite filler, and the associated textural properties, such as total BET surface area and porosity distribution in the un-oxidized material. It was also found that the amount of strongly bonded surface oxygen complexes measured by thermodesorption significantly exceeds the amount afforded by the low BET surface area, and therefore low temperature oxygen chemisorption is not a reliable method for determining the amount of surface sites (re)active during air oxidation. The relationship between nuclear graphite microstructure and its oxidation resistance demonstrated in this work underlines the importance of performing comprehensive oxidation characterization studies of the new grades of nuclear graphite considered as candidates for very high temperature gas-cooled reactors.

Contescu, Cristian I [ORNL; Guldan, Tyler R [ORNL; Wang, Peng [ORNL; Burchell, Timothy D [ORNL

2012-01-01T23:59:59.000Z

132

Efficient Production of 5-Hydroxymethylfurfural (HMF) from d-Fructose and Inulin with Graphite Derivatives as the Catalysts  

Science Journals Connector (OSTI)

The selective conversion of d-fructose and inulin to produce 5-hydroxymethyl furfural (HMF) is achieved in the presence of a catalytic amount of graphite derivatives such as graphite oxide (GO), reduced graphite ...

Guangxia Nie; Xinli Tong; Yangyang Zhang; Song Xue

2014-10-01T23:59:59.000Z

133

Retrieval of Melt Pond Coverage from MODIS using Optimal Estimation   

E-Print Network [OSTI]

results showed an error in melt pond coverage estimation of 1.1%. The technique was then applied to Svalbard sea ice over the 2003 melt season to produce an estimate of melt pond coverage evolution. This melt pond evolution showed a similar general trend...

Dodd, Emma

2011-11-24T23:59:59.000Z

134

Electroanalytical applications of screen-printable surfactant-induced sol-gel graphite composites  

DOE Patents [OSTI]

A process for preparing sol-gel graphite composite electrodes is presented. This process preferably uses the surfactant bis(2-ethylhexyl) sulfosuccinate (AOT) and eliminates the need for a cosolvent, an acidic catalyst, a cellulose binder and a thermal curing step from prior art processes. Fabrication of screen-printed electrodes by this process provides a simple approach for electroanalytical applications in aqueous and nonaqueous solvents. Examples of applications for such composite electrodes produced from this process include biochemical sensors such as disposable, single-use glucose sensors and ligand modified composite sensors for metal ion sensitive sensors.

Guadalupe, Ana R. (San Juan, PR); Guo, Yizhu (San Juan, PR)

2001-05-15T23:59:59.000Z

135

Is Graphite a Diamonds Best Friend? New Information on Material  

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

November 18th, 2003 November 18th, 2003 Is Graphite a Diamond's Best Friend? New Information on Material Transformation Science has yet to achieve the alchemist's dream of turning lead into gold. But a group of re-searchers using the GeoSoilEn-viroCARS (GSECARS) and High-Pressure Collaborative Access Team (HP-CAT) facilities at the Department of Energy's Advanced Photon Source (APS) at Argonne National Laboratory, may have found a way to turn ordinary soft graphite (source of the "lead" found in pencils) into a new, super-hard material that "looks" just like diamond. Using the high-brilliance x-ray beams from the APS, the group discovered that, under extreme pressure, graphite (among the softest of materials and the source of the lead found in pencils) becomes as hard as diamond, the

136

Effect of Graphitic Content on Carbon Supported Catalyst Performance  

SciTech Connect (OSTI)

The effect of graphitic content on carbon supported platinum catalysts was investigated in order to investigate its influence on catalyst performance. Four catalysts of varying surface areas and graphitic content were analyzed using XPS, HREELS, and tested using RDE experiments. The catalysts were also heat treated at 150oC and 100%RH as means to uniformly age them. The heat treated samples were analyzed using the same methods to determine what changes had occurred due to this aging process. When compared to the BOL catalysts, heat treated catalysts displayed increased graphitic carbon and platinum metalic content, however they also showed depressed catalytic activity. The primary cause is still under investigation, though it is believed to be related to loss of amorphous carbon content.

Patel, Anant; Artyushkova, Kateryna; Atanassov, Plamen; Harvey, David; Dutta, Monica; Colbow, Vesna

2011-07-01T23:59:59.000Z

137

Effect of Graphitic Content on Carbon Supported Catalyst Performance  

SciTech Connect (OSTI)

The effect of graphitic content on carbon supported platinum catalysts was investigated in order to investigate its influence on catalyst performance. Four catalysts of varying surface areas and graphitic content were analyzed using XPS, HREELS, and tested using RDE experiments. The catalysts were also heat treated at 150 C and 100%RH as means to uniformly age them. The heat treated samples were analyzed using the same methods to determine what changes had occurred due to this aging process. When compared to the BOL catalysts, heat treated catalysts displayed increased graphitic carbon and platinum metallic content, however they also showed depressed catalytic activity. The primary cause is still under investigation, though it is believed to be related to loss of amorphous carbon content.

A. Patel; K. Artyushkova; P. Atanassov; David Harvey; M. Dutta; V. Colbow; S. Wessel

2011-07-01T23:59:59.000Z

138

Low Cost SiOx-Graphite and Olivine Materials | Department of...  

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

Cost SiOx-Graphite and Olivine Materials Low Cost SiOx-Graphite and Olivine Materials 2010 DOE Vehicle Technologies and Hydrogen Programs Annual Merit Review and Peer Evaluation...

139

Low-Cost Graphite and Olivine-Based Materials for Li-Ion Batteries...  

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

Low-Cost Graphite and Olivine-Based Materials for Li-Ion Batteries Low-Cost Graphite and Olivine-Based Materials for Li-Ion Batteries Presentation from the U.S. DOE Office of...

140

Enhanced performance of graphite anode materials by AlF3 coating...  

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

performance of graphite anode materials by AlF3 coating for lithium-ion batteries. Enhanced performance of graphite anode materials by AlF3 coating for lithium-ion batteries....

Note: This page contains sample records for the topic "melting includes graphite" 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

Delamination fracture toughness of a unidirectional graphite/epoxy composite  

E-Print Network [OSTI]

DELAMINATION FRACTURE TOUGHNESS OF A UNIDIRECTIONAL GRAPHITE/EPOXY COMPOS ITE A Thesis by ROY CHARLES HULSEY Submitted to the Graduate College of Texas A8M University in partial fulfillment of the requirement for the degree of MASTER... OF SCIENCE December 1980 Major Subject: Mechanical Engineering DELAMINA. ION FRACTURE TOUGHNESS OF A UNIDIRECTIONAL GRAPHITE/EPOXY COMPOSITE A Thesis by ROY CHARLES HULSEY Approved as to sty1e and content by: +alter L. Brad1ey, C airman TR. A. S p...

Hulsey, Roy Charles

2012-06-07T23:59:59.000Z

142

Electronic properties of graphite in tilted magnetic fields  

SciTech Connect (OSTI)

The minimal nearest-neighbor tight-binding model with the Peierls substitution is employed to describe the electronic structure of Bernal-stacked graphite subject to tilted magnetic fields. We show that while the presence of the in-plane component of the magnetic field has a negligible effect on the Landau level structure at the K point of the graphite Brillouin zone, at the H point it leads to the experimentally observable splitting of Landau levels which grows approximately linearly with the in-plane field intensity.

Goncharuk, Nataliya A.; Smr?ka, Ludvík [Institute of Physics, Academy of Science of the Czech Republic, v. v. i., Cukrovarnická 10, 162 53 Praha 6 (Czech Republic)

2014-05-15T23:59:59.000Z

143

The dependence on excitation energy of the D-mode in graphite and carbon nanotubes  

E-Print Network [OSTI]

The dependence on excitation energy of the D-mode in graphite and carbon nanotubes C. Thomsen, S of carbon nanotubes as well. The corresponding calculated D-mode shift is shown explicitely in the nanotube is seven times narrower than in graphite as agrees with experiment. Graphite was first

Nabben, Reinhard

144

Corrosion quantification test for flanges with graphite-based gaskets  

SciTech Connect (OSTI)

The substitution of asbestos with nonasbestos fiber-reinforced materials in some industrial plants has caused corrosion problems in flanges and valves. A novel corrosion apparatus, the Corrosion Qualification Test, quantified corrosion and gives preliminary results of tests on flexible graphite-based gasket products.

Mameri, N.; Piron, D.L.; Bouzid, A.; Derenne, M.; Marchand, L.; Birembaut, Y.

2000-04-01T23:59:59.000Z

145

Tuning electrical properties of graphite oxide by plasma  

Science Journals Connector (OSTI)

...Tuning electrical properties of graphite oxide by plasma Hongfei Zhu Deyang Ji Lang Jiang Huanli Dong Wenping...consecutively by treating samples with ammonia and hydrogen plasma. When altering ammonia plasma time from 10 to 4.5min, large area (greater...

2013-01-01T23:59:59.000Z

146

Lithium intercalated graphite : experimental Compton profile for stage one  

E-Print Network [OSTI]

L-301 Lithium intercalated graphite : experimental Compton profile for stage one G. Loupias, J différence des profils Compton est compatible avec un transfert total de l'électron de conduction du lithium électronique due à l'insertion. Abstract. 2014 Electron momentum distribution of the first stage lithium

Paris-Sud XI, Université de

147

Low melting high lithia glass compositions and methods  

DOE Patents [OSTI]

The invention relates to methods of vitrifying waste and for lowering the melting point of glass forming systems by including lithia formers in the glass forming composition in significant amounts, typically from about 0.16 wt % to about 11 wt %, based on the total glass forming oxides. The lithia is typically included as a replacement for alkali oxide glass formers that would normally be present in a particular glass forming system. Replacement can occur on a mole percent or weight percent basis, and typically results in a composition wherein lithia forms about 10 wt % to about 100 wt % of the alkali oxide glass formers present in the composition. The present invention also relates to the high lithia glass compositions formed by these methods. The invention is useful for stabilization of numerous types of waste materials, including aqueous waste streams, sludge solids, mixtures of aqueous supernate and sludge solids, combinations of spent filter aids from waste water treatment and waste sludges, supernate alone, incinerator ash, incinerator offgas blowdown, or combinations thereof, geological mine tailings and sludges, asbestos, inorganic filter media, cement waste forms in need of remediation, spent or partially spent ion exchange resins or zeolites, contaminated soils, lead paint, etc. The decrease in melting point achieved by the present invention desirably prevents volatilization of hazardous or radioactive species during vitrification.

Jantzen, Carol M. (Aiken, SC); Pickett, John B. (Aiken, SC); Cicero-Herman, Connie A. (Aiken, SC); Marra, James C. (Aiken, SC)

2000-01-01T23:59:59.000Z

148

Standard Test Methods for Properties of Continuous Filament Carbon and Graphite Fiber Tows  

E-Print Network [OSTI]

1.1 These test methods cover the preparation and tensile testing of resin-impregnated and consolidated test specimens made from continuous filament carbon and graphite yarns, rovings, and tows to determine their tensile properties. 1.2 These test methods also cover the determination of the density and mass per unit length of the yarn, roving, or tow to provide supplementary data for tensile property calculation. 1.3 These test methods include a procedure for sizing removal to provide the preferred desized fiber samples for density measurement. This procedure may also be used to determine the weight percent sizing. 1.4 These test methods include a procedure for determining the weight percent moisture adsorption of carbon or graphite fiber. 1.5 The values stated in SI units are to be regarded as the standard. The values in parentheses are for information only. 1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of t...

American Society for Testing and Materials. Philadelphia

1999-01-01T23:59:59.000Z

149

Oxygen reduction on a graphite paste and a catalyst loaded graphite paste electrode  

SciTech Connect (OSTI)

Oxygen reduction was studied in basic solution at a graphite paste electrode (GPE). The GPE was used as the disk of a rotating ring disk electrode (RRDE) and experiments were done using the voltage scan technique. The enhancements afforded by catalysts applied to the GPE were also studied. Oxygen reduction on a GPE was shown to be a two-electron process resulting in the formation of peroxide. The Tafel slope (plotted as potential versus log(i/sub l/ x i/(i/sub l/ - i))) was 180 mV. The presence of gold, silver, or platinum on the GPE shifted the oxygen reduction wave approximately 800 mV in the anodic direction. Comparison of the data on a metal catalyzed GPE to the solid metal electrode showed that the former electrode produced a greater fraction of peroxide as product than did the latter. Silver and gold catalyzed GPEs gave Tagel slopes of about 120 mV. The intermediate catalysis of iron and cobalt porphyrin was also examined. While the cobalt porphyrin catalyzed oxygen reduction at a more anodic potential than the iron porphyrin, the latter appeared more active in reacting the peroxide formed as the product of the disk reaction.

DiMarco, D.M.

1980-03-01T23:59:59.000Z

150

Method for melting glass by measurement of non-bridging oxygen  

DOE Patents [OSTI]

A method for making better quality molten glass in a glass melter, the glass having the desired viscosity and, preferably, also the desired resistivity so that the glass melt can be established effectively and the product of the glass melter will have the desired level of quality. The method includes the adjustment of the composition of the glass constituents that are fed into the melter in accordance with certain correlations that reliably predict the viscosity and resistivity from the melter temperature and the melt composition, then heating the ingredients to the melter's operating temperature until they melt and homogenize. The equations include the calculation of a "non-bridging oxygen" term from the numbers of moles of the various ingredients, and then the determination of the viscosity and resistivity from the operating temperature of the melter and the non-bridging oxygen term.

Jantzen, Carol M. (3922 Wood Valley Dr., Aiken, SC 29801)

1992-01-01T23:59:59.000Z

151

Electron Coherence in a Melting Lead Monolayer  

Science Journals Connector (OSTI)

...the Pb(1,0) spots in the LEED patterns of Fig. 1, B to D...azimuthal modulation of the LEED intensities above Tm is likely not a manifestation...associated with the particular LEED spot, and {xi} is the temperature-dependent...British Columbia V6T1Z4, Canada. Electron coherence in a melting...

F. Baumberger; W. Auwärter; T. Greber; J. Osterwalder

2004-12-24T23:59:59.000Z

152

Electron Coherence in a Melting Lead Monolayer  

Science Journals Connector (OSTI)

...azimuthal modulation of the LEED intensities above Tm is likely...sixfold symmetric elementary building blocks of the 2D liquid. The slight anisotropy...associated with the particular LEED spot, and {xi} is the temperature-dependent...British Columbia V6T1Z4, Canada. Electron coherence in a melting...

F. Baumberger; W. Auwärter; T. Greber; J. Osterwalder

2004-12-24T23:59:59.000Z

153

Purification and Processing of Graphitic Carbons  

E-Print Network [OSTI]

N-Dimethylformamide EA Electric Arc-Discharge HC Hydrocarbonmethods include electric arc-discharge (EA), 18, 19 laserSWNTs prepared by electric arc-discharge were obtained from

Worsley, Kimberly Anne

2010-01-01T23:59:59.000Z

154

The Melting Layer: A Laboratory Investigation of Ice Particle Melt and Evaporation near 0°C  

Science Journals Connector (OSTI)

Melting, freezing, and evaporation of individual and aggregates of snow crystals are simulated in the laboratory under controlled temperature, relative humidity, and air velocity. Crystals of selected habit are grown on a vertical filament and ...

R. G. Oraltay; J. Hallett

2005-02-01T23:59:59.000Z

155

ARM - Lesson Plans: When Floating Ice Melts in the Sea  

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

Questions Does the water overflow when ice melts? Do you think that melting icebergs will make the sea level rise? Do you have any reason to support your answer in question (2)...

156

Graphite dust resuspension in an HTR-10 steam generator  

Science Journals Connector (OSTI)

Abstract Graphite dust has an important effect on the safety of high-temperature gas-cooled reactors (HTR). The flow field in the steam generator was studied by the computational fluid dynamics (CFD) method, with the results indicating that the friction velocity in the windward and the leeward of the heat transfer tubes is relatively low and is higher at the sides. Further analysis of the resuspension of graphite dust indicates that the resuspension fraction reaches nearly zero for particles with a diameter less than 1 ?m, whereas it will increases as the helium velocity in the steam generator increases for particle size larger than 1 ?m. Moreover, the resuspension fraction increases as the particle size increases. The results also indicate that resuspension of the particles with sizes larger than 1 ?m exhibited obvious differences in different parts of the steam generator.

Wei Peng; Tianqi Zhang; Yanan Zhen; Suyuan Yu

2014-01-01T23:59:59.000Z

157

Atomic Heat of Graphite between 1 and 20°K  

Science Journals Connector (OSTI)

The atomic heat of pure artificial polycrystalline graphite has been measured between 1 and 4°K and 10 and 20°K. Precautions were taken to ensure that no error was introduced by gas adsorbed on the graphite. Below 2°K the atomic heat can be represented as the sum of a term proportional to T3 arising from lowfrequency lattice waves and a term proportional to T due to electrons: C=0.0325T3+0.031T millijoules/mole degree. Between 2.25°K and 4.5°K, C=0.115T2+0.031T-0.237 millijoules/mole degree; between 10 20°K, C=0.208T2-6.8 millijoules/mole degree.

P. H. Keesom and N. Pearlman

1955-08-15T23:59:59.000Z

158

OBSERVATION AND MODELING OF A BURIED MELT-FREEZE CRUST Michael Smith1  

E-Print Network [OSTI]

form throughout the winter in Western Canada as the result of rain, wet snow or solar insola- tion December melt-freeze crust that was present throughout much of Western Canada. The data gathered included. Dept. of Civil Engineer- ing, University of Calgary, Calgary, AB, Canada; Tel 1+403-200-2904; email

Jamieson, Bruce

159

Rotational Transition of Incommensurate Kr Monolayers on Graphite  

Science Journals Connector (OSTI)

Synchrotron x-ray diffraction studies of the orientational epitaxy of krypton on single-crystal graphite are reported. The system displays a continuous transition from an aligned to a rotated orientation with increasing mean misfit in a manner predicted by a hexagonal-domain-wall model of the weakly incommensurate phase. A hysteresis at the critical misfit is observed. The results are discussed in light of current views of the structure of the incommensurate phase.

K. L. D'Amico; D. E. Moncton; E. D. Specht; R. J. Birgeneau; S. E. Nagler; P. M. Horn

1984-12-03T23:59:59.000Z

160

X-ray diffraction data for graphite to 20 GPa  

Science Journals Connector (OSTI)

X-ray diffraction data have been obtained on polycrystalline graphite at pressures up to 20 GPa. A phase transition is observed at ?11 GPa, as evidenced by softening in the interlayer spacing and the observation of new diffraction lines. Below this pressure the variation of the lattice parameters a and c are compared with elastic stiffnesses obtained from ultrasonic measurements. A new value for C13 is proposed. The variation c(P) is compared to the recently proposed universal isotherm equation.

You Xiang Zhao and Ian L. Spain

1989-07-15T23:59:59.000Z

Note: This page contains sample records for the topic "melting includes graphite" 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

Ethylene on graphite: Heats of adsorption and phase diagram  

Science Journals Connector (OSTI)

Isosteric heats of adsorption (qst) of ethylene on Grafoil MAT have been measured calorimetrically in the region 98ethylene-graphite interaction potential, a value is obtained for the heat of adsorption at zero coverage, qst(0)=20.4±0.2 kJ?l-1, at T=120 K. At this temperature, the effects of surface heterogeneity and of clustering of the adsorbed molecules are clearly delineated and thus permit an extrapolation to be made with reasonable certainty.

A. Inaba and J. A. Morrison

1986-09-01T23:59:59.000Z

162

Structure of the solid D2 bilayer on graphite  

Science Journals Connector (OSTI)

Low-energy electron-diffraction (LEED) measurements for a solid D2 bilayer physisorbed on graphite are used to investigate the bilayer structure and its azimuthal orientation relative to the substrate. The LEED spot positions are consistent with the mutually commensurate oblique unit cell inferred from neutron-diffraction measurement. Given the azimuthal orientation of the bilayer LEED spots, the possibility of a bilayer composed of two incommensurate layers with mutually modulated triangular lattices is ruled out.

Wei Liu and S. C. Fain; Jr.

1993-06-15T23:59:59.000Z

163

MICROMECHANICS IN CONTINOUS GRAPHITE FIBER/EPOXY COMPOSITES DURING CREEP  

SciTech Connect (OSTI)

Micro Raman spectroscopy and classic composite shear-lag models were used to analyze the evolution with time of fiber and matrix strain/stress around fiber breaks in planar model graphite fiber-epoxy matrix composites. Impressive agreements were found between the model predictions and the experimental results. The local matrix creep leads to an increase in the load transfer length around the break under a constant load. This increases the chance of fiber breakage in the neighboring intact fibers.

C. ZHOU; ET AL

2001-02-01T23:59:59.000Z

164

Catalytic Graphitization of Carbon Aerogels by Transition Metals  

Science Journals Connector (OSTI)

Catalytic Graphitization of Carbon Aerogels by Transition Metals ... Carbon aerogels and Cr-, Fe-, Co-, and Ni-containing carbon aerogels were obtained by pyrolysis, at temperatures between 500 and 1800 °C, of the corresponding aerogels prepared by the sol?gel method from polymerization of resorcinol with formaldehyde. ... Results obtained show that carbon aerogels are, essentially, macroporous materials that maintain large pore volumes even after pyrolysis at 1800 °C. ...

F. J. Maldonado-Hódar; C. Moreno-Castilla; J. Rivera-Utrilla; Y. Hanzawa; Y. Yamada

2000-03-24T23:59:59.000Z

165

Graphite having improved thermal stress resistance and method of preparation  

DOE Patents [OSTI]

An improved method for fabricating a graphite article comprises the steps of impregnating a coke article by first heating the coke article in contact with a thermoplastic pitch at a temperature within the range of 250.degree.-300.degree. C. at a pressure within the range of 200-2000 psig for at least 4-10 hours and then heating said article at a temperature within the range of 450.degree.-485.degree. C. at a pressure of 200-2000 psig for about 16-24 hours to provide an impregnated article; heating the impregnated article for sufficient time to carbonize the impregnant to provide a second coke article, and graphitizing the second coke article. A graphite having improved thermal stress resistance results when the coke to be impregnated contains 1-3 wt.% sulfur and no added puffing inhibitors. An additional improvement in thermal stress resistance is achieved when the second coke article is heated above about 1400.degree. C. at a rate of at least 10.degree. C./minute to a temperature above the puffing temperature.

Kennedy, Charles R. (Oak Ridge, TN)

1980-01-01T23:59:59.000Z

166

Regelation: why does ice melt under pressure?  

E-Print Network [OSTI]

Unlike other unusual materials whose bonds contract under compression, the O:H nonbond undergoes contraction and the H-O bond elongation towards O:H and H-O length symmetry in water and ice. The energy drop of the H-O bond dictates the melting point Tm depression of ice. Once the pressure is relieved, the O:H-O bond fully recovers its initial state, resulting in Regelation.

Sun, Chang Q

2015-01-01T23:59:59.000Z

167

On the preparation of TiAl alloy by direct reduction of the oxide mixtures in calcium chloride melt  

SciTech Connect (OSTI)

In recent years, TiAl-based intermetallic alloys are being increasingly considered for application in areas such as (i) automobile/transport sector (passenger cars, trucks and ships) (ii) aerospace industry (jet engines and High Speed Civil Transport propulsion system) and (iii) industrial gas turbines. These materials offer excellent (i) high temperature properties (at higher than 6000C) (ii) mechanical strength and (iii) resistance to corrosion and as a result have raised renewed interest. The combination of these properties make them possible replacement materials for traditional nickel-based super-alloys, which are nearly as twice as dense (than TiAl based alloys). Since the microstructures of these intermetallic alloys affect, to a significant extent, their ultimate performance, further improvements (by way of alteration/modification of these microstructures), have been the subject matter of intense research investigations. It has now been established that the presence of alloy additives, such as niobium, tantalum, manganese, boron, chromium, silicon, nickel and yttrium etc, in specific quantities, impart marked improvement to the properties, viz. fatigue strength, fracture toughness, oxidation resistance and room temperature ductility, of these alloys. From a number of possible alloy compositions, {gamma}-TiAl and Ti-Al-Nb-Cr have, of late, emerged as two promising engineering alloys/materials. . The conventional fabrication process of these alloys include steps such as melting, forging and heat treatment/annealing of the alloy compositions. However, an electrochemical process offers an attractive proposition to prepare these alloys, directly from the mixture of the respective oxides, in just one step. The experimental approach, in this new process, was, therefore, to try to electrochemically reduce the (mixed) oxide pellet to an alloy phase. The removal of oxygen, from the (mixed) oxide pellet, was effected by polarizing the oxide pellet against a graphite electrode in a pool of molten calcium chloride at a temperature of 9000C. The dominant mechanism of the oxygen removal was the ionization of oxygen followed by its subsequent discharge, as CO2/CO, at the anode surface. The removal of oxygen from the oxide mixture helped form the alloy in situ. The presentation shall cover the detailed experimental results pertaining to the preparation, evaluation and characterization of Ti-47Al-2Nb-2Cr (atom%) alloy.

Prabhat K. Tripathy; Derek J. Fray

2011-11-01T23:59:59.000Z

168

Evaluation of feeds for melt and dilute process using an analytical hierarchy process  

SciTech Connect (OSTI)

Westinghouse Savannah River Company was requested to evaluate whether nuclear materials other than aluminum-clad spent nuclear fuel should be considered for treatment to prepare them for disposal in the melt and dilute facility as part of the Treatment and Storage Facility currently projected for construction in the L-Reactor process area. The decision analysis process used to develop this analysis considered many variables and uncertainties, including repository requirements that are not yet finalized. The Analytical Hierarchy Process using a ratings methodology was used to rank potential feed candidates for disposition through the Melt and Dilute facility proposed for disposition of Savannah River Site aluminum-clad spent nuclear fuel. Because of the scoping nature of this analysis, the expert team convened for this purpose concentrated on technical feasibility and potential cost impacts associated with using melt and dilute versus the current disposition option. This report documents results of the decision analysis.

Krupa, J.F.

2000-03-22T23:59:59.000Z

169

A parametric model for analysis of melt progression in U-A1 assemblies  

SciTech Connect (OSTI)

A computational model has been developed that calculates the thermal degradation of the reactor core of the production reactors at the Savannah River Site (SRS) under postulated severe accident conditions. This model addresses heatup and degradation of the U-Al fuel and Li-Al or U-metal target assemblies and neighboring structures. Models included are those for assembly heatup due to decay heat generation, material melting and relocation, volume expansion of fuel due to foaming and melt/debris accumulation in assembly bottom end-fittings. Sample results are presented that illustrate the effect of alternative assumptions regarding the temperature at which U-Al alloy melts and relocates and the extent to which fuel foaming thermally couples adjacent fuel and target tubes. 5 refs., 6 figs., 1 tab.

Paik, I.K. (Westinghouse Savannah River Co., Aiken, SC (USA)); Kim, S.H.; Leonard, M.T.; Amos, C.N. (Science Applications International Corp., Albuquerque, NM (USA))

1990-06-15T23:59:59.000Z

170

Characterization of Nanoparticle/Polymer Melt Composites  

Science Journals Connector (OSTI)

Two types of nanoparticles are studied: carbon nanofibers and nanoclays. These nanoparticles are incorporated into a polystyrene matrix using different techniques. For the carbon nanofiber/PS composite solvent casting assisted with sonication and melt compounding methods are used. For nanoclay/PS system exfoliated and intercalated composites are prepared using in?situ polymerization and melt compounding methods respectively. Dispersion of these nanoparticles in the PS matrix is studied using TEM SEM and XRD. Rheological characterization of these composites is studied using the Rheometrics Mechanical Spectrometer (RMS800) for shear rheology and Rheometrics Melt Extensiometer (RME) for extensional rheology. Effects of the nanoparticle concentration and dispersion methods on the rheology are studied. The morphology of the composites is studied after the samples have been deformed in the rheometers at certain stage. The orientation of the nanoparticles is quantified based on TEM micrographs. Models are developed to relate the rheology the rheology of nanoparticle/polymer composites to particle concentration orientation and length; these model predictions are compared with our experimentak measurements.

Kurt Koelling; Stephen Bechtel; Jianhua Xu; Yingru Wang

2004-01-01T23:59:59.000Z

171

Electron spin resonance study of proton-irradiation-induced defects in graphite  

SciTech Connect (OSTI)

Electron spin resonance measurements of proton-irradiated graphite have revealed detailed nature of proton-irradiation-induced defects. Our results indicate that proton-irradiation creates confined defect regions of a metallic island surrounded by an insulating magnetic region which ''isolates'' the metallic island inside from the metallic graphite background outside. We have thus come up with a picture of phase separation in proton-irradiated graphite comprising three regions of distinct electrical and magnetic properties.

Won Lee, Kyu; Kweon, H.; Kweon, J. J.; Lee, Cheol Eui [Department of Physics and Institute for Nano Science, Korea University, Seoul 136-713 (Korea, Republic of)

2010-02-15T23:59:59.000Z

172

Laser-induced dehydration of graphite oxide coatings on polymer substrates  

SciTech Connect (OSTI)

Nanosized graphite has been oxidized by the Hummers method to give high quality graphite oxide. This reaction is characterized by a very fast kinetic behavior and a high yield. The produced graphite oxide has been conveniently used to pattern graphene by using a standard photolithographic method, and the resulting systems have been characterized by optical microscopy (OM), scanning electron microscopy (SEM) and by Fourier transform infrared spectroscopy (FT-IR) and Visible-Near Infrared spectroscopy (Vis-NIR)

Longo, Angela, E-mail: angela.longo@cnr.it; Palomba, Mariano; Carotenuto, Gianfranco; Nicolais, Luigi [Institute for Composite and Biomedical Materials, National Research Council, Viale Kennedy, 54, Mostra d'Oltremare Padiglione 20, 80125 Napoli (Italy); Orabona, Emanuele; Maddalena, Pasqualino [Department of Physics, University of Naples, Federico II, via cintia, 80126, Naples, Italy and SPIN Institute, National Research Council, UOS Naples, via cintia, 80126, Naples (Italy); Ambrosio, Antonio [SPIN Institute, National Research Council, UOS Naples, via cintia, 80126, Naples (Italy)

2014-05-15T23:59:59.000Z

173

Understanding Creep Mechanisms in Graphite with Experiments, Multiscale Simulations, and Modeling  

SciTech Connect (OSTI)

Disordering mechanisms in graphite have a long history with conflicting viewpoints. Using Raman and x-ray photon spectroscoy, electron microscopy, x-ray diffraction experiments and atomistic modeling and simulations, the current project has developed a fundamental understanding of early-to-late state radiation damage mechanisms in nuclear reactor grade graphite (NBG-18 and PCEA). We show that the topological defects in graphite play an important role under neutron and ion irradiation.

Eapen, Jacob; Murty, Korukonda; Burchell, Timothy

2014-06-02T23:59:59.000Z

174

Dynamics of the egress of gas microbubbles from a melt under laser irradiation of a metal surface  

SciTech Connect (OSTI)

The results of a theoretical investigation of the efficiency of degassing of the near-surface region of a material exposed to laser radiation are presented. The case of a low volume concentration of the monodispersed gas phase representing microbubbles of size no greater than 10 {mu}m is considered. The principal parameters are revealed which determine the regimes of the egress of gas bubbles from a laser-produced melt, and analytical formulas are obtained for estimating the process rate. The analytical results are compared with the results of two-dimensional numerical simulations which include the laser heating of a solid sample, its melting, the development of thermocapillary melt convection, and the escape of gas bubbles from the melt. The analytical and numerical results are found to be in good agreement. (laser applications and other topics in quantum electronics)

Likhanskii, V V; Loboiko, A I [State Research Center of Russian Federation 'Troitsk Institute for Innovation and Fusion Research', Troitsk, Moscow Region (Russian Federation)

2000-09-30T23:59:59.000Z

175

Low-Cost Graphite and Olivine-Based Materials for Li-Ion Batteries  

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

WORK Identify suitable graphite materials for anodes that meet the requirement for low cost and long cycle life. Fabricate half cells (Ligraphite) and Li-ion (graphiteolivine)...

176

Properties of copper/graphite/carbon nanotubes composite reinforced by carbon nanotubes  

Science Journals Connector (OSTI)

Electroless Cu plating was used for flake G powder and CNTs, Cu–G–CNTs (copper/graphite/carbon nanotubes) composites were manufactured by means of powder...

Xin-Ying Liu; Xiong-Zhi Xiang; Fei Niu; Xiao-Jun Bai

2013-06-01T23:59:59.000Z

177

Thermal Characterization of Graphitic Carbon Foams for Use in Thermal Storage Applications.  

E-Print Network [OSTI]

?? Highly conductive graphitic foams are currently being studied for use as thermal conductivity enhancers (TCEs) in thermal energy storage (TES) systems. TES systems store… (more)

Drummond, Kevin P.

2012-01-01T23:59:59.000Z

178

Inelastic Thermal Neutron Scattering Cross Sections for Reactor-grade Graphite  

Science Journals Connector (OSTI)

Abstract Current calculations of the inelastic thermal neutron scattering cross sections of graphite are based on representing the material using ideal single crystal models. However, the density of reactor-grade graphite is usually in the range of 1.5 g/cm3 to approximately 1.8 g/cm3, while ideal graphite is characterized by a density of nearly 2.25 g/cm3. This difference in density is manifested as a significant fraction of porosity in the structure of reactor-grade graphite. To account for the porosity effect on the cross sections, classical molecular dynamics (MD) techniques were employed to simulate graphite structures with porosity concentrations of 10% and 30%, which are taken to be representative of reactor-grade graphite. The phonon density of states for the porous systems were generated as the power spectrum of the MD velocity autocorrelation functions. The analysis revealed that for porous graphite the phonon density of states exhibit a rise in the lower frequency region that is relevant to neutron thermalization. Using the generated phonon density of states, the inelastic thermal neutron scattering cross sections were calculated using the NJOY code system. While marked discrepancies exist between measurements and calculations based on ideal graphite models, favorable agreement is found between the calculations based on the porous graphite models and measured data.

A.I. Hawari; V.H. Gillete

2014-01-01T23:59:59.000Z

179

E-Print Network 3.0 - ams graphite target Sample Search Results  

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

F. J Appl Phys Lett 1976;29:118-20. Improving colloidal graphite for electromagnetic interference... January 2003; received in revised form 30 January 2003; accepted 30...

180

Microsoft Word - 911136_0 SSC-4b Reactor Graphite Test Plan_rel...  

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

Services for the Next Generation Nuclear Plant (NGNP) with Hydrogen Production Test Plan for Reactor Graphite Elements Prepared by General Atomics for the Battelle Energy...

Note: This page contains sample records for the topic "melting includes graphite" 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

Graphitic Electrical Contacts to Metallic Single Walled Carbon Nanotubes Using Pt Electrodes  

E-Print Network [OSTI]

NANO LETTERS Graphitic Electrical Contacts to Metallicof the interfacial electrical resistance between nano- tubesprovide excellent electrical contacts to many types of

Collins, Philip G

2009-01-01T23:59:59.000Z

182

Meals included in Conference Registrations  

E-Print Network [OSTI]

Meals included in Conference Registrations Meals included as part of the cost of a conference the most reasonable rates are obtained. Deluxe hotels and motels should be avoided. GSA rates have been for Georgia high cost areas. 75% of these amounts would be $21 for non- high cost areas and $27 for high cost

Arnold, Jonathan

183

Melting Instantons, Domain Walls, and Large N  

E-Print Network [OSTI]

Monte Carlo studies of $CP^{N-1}$ sigma models have shown that the structure of topological charge in these models undergoes a sharp transition at $N=N_c\\approx 4$. For $NN_c$ it is dominated by extended, thin, 1-dimensionally coherent membranes of topological charge, which can be interpreted as domain walls between discrete quasi-stable vacua. These vacua differ by a unit of background electric flux. The transition can be identified as the delocalization of topological charge, or "instanton melting," a phenomenon first suggested by Witten to resolve the conflict between instantons and large $N$ behavior. Implications for $QCD$ are discussed.

H. B. Thacker

2008-10-22T23:59:59.000Z

184

Structural study of monolayer cobalt phthalocyanine adsorbed on graphite  

E-Print Network [OSTI]

We present microscopic investigations on the two-dimensional arrangement of cobalt phthalocyanine molecules on a graphite (HOPG) substrate in the low coverage regime. The initial growth and ordering of molecular layers is revealed in high resolution scanning tunneling microscopy (STM). On low coverages single molecules orient mostly along one of the substrate lattice directions, while they form chains at slightly higher coverage. Structures with two different unit cells can be found from the first monolayer on. A theoretical model based on potential energy calculations is presented, which relates the two phases to the driving ordering forces.

Scheffler, M; Baumann, D; Schlegel, R; Hänke, T; Toader, M; Büchner, B; Hietschold, M; Hess, C

2014-01-01T23:59:59.000Z

185

Interaction of graphite with a hot, dense deuterium plasma  

SciTech Connect (OSTI)

The erosion of ATJ-S graphite caused by a hot, dense deuterium plasma has been investigated experimentally. The plasma was produced in an electromagnetic shock tube. Plasma characteristics were typically: ion temperature approx. = 800 eV (approx. 1 x 10/sup 7/ /sup 0/K), number density approx. = 10/sup 16//cm/sup 3/, and transverse magnetic field approx. = 1 tesla. The energetic ion flux, phi, to the sample surfaces was approx. 10/sup 23/ ions/cm/sup 2/-sec for a single pulse duration of approx. 0.1 usec. Sample surfaces were metallographically prepared and examined with a scanning electron microscope before and after exposure.

Desko, J.C. Jr.

1980-01-01T23:59:59.000Z

186

Method of fabricating silicon carbide coatings on graphite surfaces  

DOE Patents [OSTI]

The vacuum plasma spray process produces well-bonded, dense, stress-free coatings for a variety of materials on a wide range of substrates. The process is used in many industries to provide for the excellent wear, corrosion resistance, and high temperature behavior of the fabricated coatings. In this application, silicon metal is deposited on graphite. This invention discloses the optimum processing parameters for as-sprayed coating qualities. The method also discloses the effect of thermal cycling on silicon samples in an inert helium atmosphere at about 1,600 C which transforms the coating to silicon carbide. 3 figs.

Varacalle, D.J. Jr.; Herman, H.; Burchell, T.D.

1994-07-26T23:59:59.000Z

187

Method of fabricating silicon carbide coatings on graphite surfaces  

DOE Patents [OSTI]

The vacuum plasma spray process produces well-bonded, dense, stress-free coatings for a variety of materials on a wide range of substrates. The process is used in many industries to provide for the excellent wear, corrosion resistance, and high temperature behavior of the fabricated coatings. In this application, silicon metal is deposited on graphite. This invention discloses the optimum processing parameters for as-sprayed coating qualities. The method also discloses the effect of thermal cycling on silicon samples in an inert helium atmosphere at about 1600.degree.C. which transforms the coating to silicon carbide.

Varacalle, Jr., Dominic J. (Idaho Falls, ID); Herman, Herbert (Port Jefferson, NY); Burchell, Timothy D. (Oak Ridge, TN)

1994-01-01T23:59:59.000Z

188

SUMMARY OF 2010 DOE EM INTERNATIONAL PROGRAM STUDIES OF WASTE GLASS MELT RATE ENHANCEMENT  

SciTech Connect (OSTI)

A collaborative study has been established under the U.S. Department of Energy (DOE) Office of Environmental Management International Program between the Savannah River National Laboratory (SRNL) and the V. G. Khlopin Radium Institute (KRI) in St. Petersburg, Russia, to investigate potential improvements in melt rate via chemical additions to the glass frit. Researchers at KRI suggested a methodology for selecting frit additives based on empirical coefficients for optimization of glass melting available in the Russian literature. Using these coefficients, KRI identified B{sub 2}O{sub 3}, CuO, and MnO as frit additives that were likely to improve melt rate without having adverse effects on crystallization of the glass or its chemical durability. The results of the melt rate testing in the SMK melter showed that the slurry feed rate (used as a gauge of melt rate) could be significantly increased when MnO or CuO were added to Frit 550 with the SMR-2 sludge. The feed rates increased by about 27% when MnO was added to the frit and by about 26% when CuO was added to the frit, as compared to earlier results for Frit 550 alone. The impact of adding additional B{sub 2}O{sub 3} to the frit was minor when added with CuO. The additional B{sub 2}O{sub 3} showed a more significant, 39% improvement in melt rate when added with MnO. The additional B{sub 2}O{sub 3} also reduced the viscosity of the glasses during pouring. Samples of the glasses from the melt rate testing characterized at SRNL showed that there were no significant impacts on crystallization of the glasses. All of the glasses had very good chemical durability. Chemical composition measurements showed that the frit additives were present in concentrations below the targeted values in some of the glasses. Therefore, it is possible that higher concentrations of these additives may further improve melt rate, although the impacts of higher concentrations of these components on crystallization and durability would need to be determined. Overall, the results show an excellent potential for these additives to significantly improve waste throughput for DOE vitrification facilities. A complete report from KRI is included as an appendix to this document.

Fox, K.; Marra, J.

2011-01-19T23:59:59.000Z

189

Arctic melt ponds and bifurcations in the climate system  

E-Print Network [OSTI]

Understanding how sea ice melts is critical to climate projections. In the Arctic, melt ponds that develop on the surface of sea ice floes during the late spring and summer largely determine their albedo $-$ a key parameter in climate modeling. Here we explore the possibility of a simple sea ice climate model passing through a bifurcation point $-$ an irreversible critical threshold as the system warms, by incorporating geometric information about melt pond evolution. This study is based on a nonlinear phase transition model for melt ponds, and bifurcation analysis of a simple climate model with ice - albedo feedback as the key mechanism driving the system to a potential bifurcation point.

Sudakov, Ivan; Golden, Kenneth M

2014-01-01T23:59:59.000Z

190

Photoinduced Effects in UV Laser Melting of Si in UHV  

Science Journals Connector (OSTI)

The dynamics of laser heating and melting of Si in UHV is investigated by transient reflectivity with single pulse sensitivity. It is found that the heating and melting dynamics cannot be accounted for by a model of heat flow using the thermal and optical properties of Si. Experiment and theory can be reconciled assuming significantly smaller thermal conductivity and heat capacity at all temperatures from ambient to melting. The melting temperature is also smaller. It is suggested that these specific parameters are related to the photoinduced plasma.

Bogdan Dragnea and Bernard Bourguignon

1999-04-12T23:59:59.000Z

191

Energy-Efficient Melting and Direct Delivery of High Quality...  

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

preparing and melting the metal off-site using efficient electric Direct Immersion (DI) heat- ers, then transporting the molten metal in Transportable Electric Ladle (TEL) trucks...

192

Evaluation of co-cokes from bituminous coal with vacuum resid or decant oil, and evaluation of anthracites, as precursors to graphite.  

E-Print Network [OSTI]

??Graphite is utilized as a neutron moderator and structural component in some nuclear reactor designs. During the reactor operaction the structure of graphite is damaged… (more)

Nyathi, Mhlwazi

2011-01-01T23:59:59.000Z

193

Theoretical Description of the STM Images of Alkanes and Substituted Alkanes Adsorbed on Graphite  

E-Print Network [OSTI]

Theoretical Description of the STM Images of Alkanes and Substituted Alkanes Adsorbed on Graphite the scanning tunneling microscopy (STM) images of molecules adsorbed on graphite. The model is applicable diffuse virtual orbitals of the adsorbed molecules, despite being much farther in energy from the Fermi

Goddard III, William A.

194

Emission characteristics and dynamics of C2 from laser produced graphite plasma  

E-Print Network [OSTI]

Emission characteristics and dynamics of C2 from laser produced graphite plasma S. S. Harilal, Riju 1996; accepted for publication 20 December 1996 The emission features of laser ablated graphite plume diagnostic technique. Time resolved optical emission spectroscopy is employed to reveal the velocity

Harilal, S. S.

195

Adsorption of the first layer of argon on graphite (*) Laboratoire des Composs non St0153chiomtriques,  

E-Print Network [OSTI]

]. The cooling bath is solid nitrogen obtained by pumping. The adsorption cell, enclosed in an aluminium blockL-9 Adsorption of the first layer of argon on graphite (*) F. Millot Laboratoire des Composés non déterminé des isothermes d'adsorption d'argon sur le graphite entre 55 et 62 K. Nous proposons une

Boyer, Edmond

196

Hydrogen storage material and process using graphite additive with metal-doped complex hydrides  

DOE Patents [OSTI]

A hydrogen storage material having improved hydrogen absorbtion and desorption kinetics is provided by adding graphite to a complex hydride such as a metal-doped alanate, i.e., NaAlH.sub.4. The incorporation of graphite into the complex hydride significantly enhances the rate of hydrogen absorbtion and desorption and lowers the desorption temperature needed to release stored hydrogen.

Zidan, Ragaiy (Aiken, SC); Ritter, James A. (Lexington, SC); Ebner, Armin D. (Lexington, SC); Wang, Jun (Columbia, SC); Holland, Charles E. (Cayce, SC)

2008-06-10T23:59:59.000Z

197

Late-time particle emission from laser-produced graphite plasma S. S. Harilal,a)  

E-Print Network [OSTI]

-produced carbon plasma. Furthermore, in the design of Tokamaks for nuclear fusion, graphite has been proposedLate-time particle emission from laser-produced graphite plasma S. S. Harilal,a) A. Hassanein online 6 September 2011) We report a late-time "fireworks-like" particle emission from laser

Harilal, S. S.

198

Generation of graphitic soot by an urban fire storm  

SciTech Connect (OSTI)

The authors have obtained samples of aerosols deposited during the Hiroshima fire storm that was initiated by the atomic bomb detonated on August 6, 1945. These particles, which we extracted from streaks of black rain found on a plaster wall, are being studied. Initial studies show that the artifact appears to contain aerosol particles that may be representative of the aerosols that may lead to a nuclear winter. Aerosol generation in urban fire storms have been considered by studying these particles. The presence of graphite as a component of these particles is suggested by electron photomicrographs and has been confirmed using Raman spectroscopy, surface ionization mass spectroscopy, and electron scattering for chemical analysis. Several hypotheses are being considered to explain the presence of this form of carbon. Among these are generation in sooty clouds, in raindrops, in the interior of the first storm, and on the wall surface itself. The distribution of particle sizes suggests that the residence time of particles in the atmosphere would be long if they were not removed by rainout. An experimental and theoretical examination of the conditions necessary to produce graphitic soot is in progress.

Fields, D.E.; Cole, L.L.

1987-01-01T23:59:59.000Z

199

Benchmarking of Graphite Reflected Critical Assemblies of UO2  

SciTech Connect (OSTI)

A series of experiments were carried out in 1963 at the Oak Ridge National Laboratory Critical Experiments Facility (ORCEF) for use in space reactor research programs. A core containing 93.2% enriched UO2 fuel rods was used in these experiments. The first part of the experimental series consisted of 253 tightly-packed fuel rods (1.27 cm triangular pitch) with graphite reflectors [1], the second part used 253 graphite-reflected fuel rods organized in a 1.506 cm triangular pitch [2], and the final part of the experimental series consisted of 253 beryllium-reflected fuel rods with a 1.506 cm triangular pitch. [3] Fission rate distribution and cadmium ratio measurements were taken for all three parts of the experimental series. Reactivity coefficient measurements were taken for various materials placed in the beryllium reflected core. The first part of this experimental series has been evaluated for inclusion in the International Reactor Physics Experiment Evaluation Project (IRPhEP) [4] and the International Criticality Safety Benchmark Evaluation Project (ICSBEP) Handbooks, [5] and is discussed below. These experiments are of interest as benchmarks because they support the validation of compact reactor designs with similar characteristics to the design parameters for a space nuclear fission surface power systems. [6

Margaret A. Marshall; John D. Bess

2011-11-01T23:59:59.000Z

200

Project of Rotating Carbon High-Power Neutron Target. Research of Graphite Properties for Production of High Intensity Neutron Source  

E-Print Network [OSTI]

Project of Rotating Carbon High-Power Neutron Target. Research of Graphite Properties for Production of High Intensity Neutron Source

Gubin, K V; Bak, P A; Kot, N K; Logatchev, P V

2001-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "melting includes graphite" 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

Effects of Stone-Wales and vacancy defects in atomic-scale friction on defective graphite  

SciTech Connect (OSTI)

Graphite is an excellent solid lubricant for surface coating, but its performance is significantly weakened by the vacancy or Stone-Wales (SW) defect. This study uses molecular dynamics simulations to explore the frictional behavior of a diamond tip sliding over a graphite which contains a single defect or stacked defects. Our results suggest that the friction on defective graphite shows a strong dependence on defect location and type. The 5-7-7-5 structure of SW defect results in an effectively negative slope of friction. For defective graphite containing a defect in the surface, adding a single vacancy in the interior layer will decrease the friction coefficients, while setting a SW defect in the interior layer may increase the friction coefficients. Our obtained results may provide useful information for understanding the atomic-scale friction properties of defective graphite.

Sun, Xiao-Yu [Department of Engineering Mechanics, School of Civil Engineering, Wuhan University, Wuhan 430072 (China); Key Laboratory of Hubei Province for Water Jet Theory and New Technology, Wuhan University, Wuhan 430072 (China); Wu, RunNi; Xia, Re [Key Laboratory of Hubei Province for Water Jet Theory and New Technology, Wuhan University, Wuhan 430072 (China); Chu, Xi-Hua; Xu, Yuan-Jie, E-mail: yj-xu@whu.edu.cn [Department of Engineering Mechanics, School of Civil Engineering, Wuhan University, Wuhan 430072 (China)

2014-05-05T23:59:59.000Z

202

Preliminary analysis of graphite dust releasing behavior in accident for HTR  

SciTech Connect (OSTI)

The behavior of the graphite dust is important to the safety of High Temperature Gas-cooled Reactors. This study investigated the flow of graphite dust in helium mainstream. The analysis of the stresses acting on the graphite dust indicated that gas drag played the absolute leading role. Based on the understanding of the importance of gas drag, an experimental system is set up for the research of dust releasing behavior in accident. Air driven by centrifugal fan is used as the working fluid instead of helium because helium is expensive, easy to leak which make it difficult to seal. The graphite particles, with the size distribution same as in HTR, are added to the experiment loop. The graphite dust releasing behavior at the loss-of-coolant accident will be investigated by a sonic nozzle. (authors)

Peng, W.; Yang, X. Y.; Yu, S. Y.; Wang, J. [Inst. of Nuclear and New Energy Technology, Tsinghua Univ., Beijing100084 (China)

2012-07-01T23:59:59.000Z

203

Sponsorship includes: Agriculture in the  

E-Print Network [OSTI]

Sponsorship includes: · Agriculture in the Classroom · Douglas County Farm Bureau · Gifford Farm · University of Nebraska Agricultural Research and Development Center · University of Nebraska- Lincoln Awareness Coalition is to help youth, primarily from urban communities, become aware of agriculture

Nebraska-Lincoln, University of

204

Impact of high energy ball milling on the nanostructure of magnetite–graphite and magnetite–graphite–molybdenum disulphide blends  

SciTech Connect (OSTI)

Different, partly complementary and partly redundant characterization methods were applied to study the transition of magnetite, graphite and MoS{sub 2} powders to mechanically alloyed nanostructures. The applied methods were: Transmission electron microscopy (TEM), Mössbauer spectroscopy (MS), Raman spectroscopy (RS), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The main objective was to prepare a model material providing the essential features of a typical tribofilm forming during automotive braking, and to assess the impact of different constituents on sliding behaviour and friction level. Irrespective of the initial grain size, the raw materials were transferred to a nanocrystalline structure and mixed on a nanoscopic scale during high energy ball milling. Whereas magnetite remained almost unchanged, graphite and molybdenum disulphide were transformed to a nanocrystalline and highly disordered structure. The observed increase of the coefficient of friction was attributed to a loss of lubricity of the latter ingredient due to this transformation and subsequent oxidation. - Highlights: • Characterization of microstructural changes induced by high energy ball milling • Assessment of the potential of different characterization methods • Impact of mechanical alloying on tribological performance revealed by tests • Preparation of an artificial third body resembling the one formed during braking.

Österle, W., E-mail: Werner.oesterle@bam.de [BAM Federal Institute for Materials Research and Testing, 12200 Berlin (Germany); Orts-Gil, G.; Gross, T.; Deutsch, C. [BAM Federal Institute for Materials Research and Testing, 12200 Berlin (Germany); Hinrichs, R. [Instituto de Geocięncias, UFRGS, P.O. Box 15001, 91501-970 Porto Alegre (Brazil); Vasconcellos, M.A.Z. [Instituto de Física, UFRGS, P.O. Box 15051, 91501-970 Porto Alegre (Brazil); Zoz, H.; Yigit, D.; Sun, X. [Zoz Group, 57482 Wenden (Germany)

2013-12-15T23:59:59.000Z

205

Homogeneous bubble nucleation in rhyolitic melt: Experiments and nonclassical theory  

E-Print Network [OSTI]

Homogeneous bubble nucleation in rhyolitic melt: Experiments and nonclassical theory H. M eruptions. The first and most critical step in degassing is the nucleation of gas bubbles, which requires inferred from bubble nucleation experiments in silicate melts are, however, lower than direct macroscopic

Gonnermann, Helge

206

Bubble growth in rhyolitic melt Yang Liu, Youxue Zhang *  

E-Print Network [OSTI]

Bubble growth in rhyolitic melt Yang Liu, Youxue Zhang * The Department of Geological Sciences June 2000; accepted 8 June 2000 Abstract We report experimental data of bubble growth in natural rhyolitic melt with 1.4^2.0 wt% initial total H2O at 0.1 MPa and 500^600ÂłC. Growth of many bubbles

Zhang, Youxue

207

Chemical Characterization and Removal of Carbon-14 from Irradiated Graphite II - 13023  

SciTech Connect (OSTI)

Approximately 250,000 tonnes of irradiated graphite waste exists worldwide and that quantity is expected to increase with decommissioning of Generation II reactors and deployment of Generation IV gas-cooled, graphite moderated reactors. This situation indicates the need for a graphite waste management strategy. Of greatest concern for long-term disposal of irradiated graphite is carbon-14 (C-14), with a half-life of 5730 years. Study of irradiated graphite from some nuclear reactors indicates C-14 is concentrated on the outer 5 mm of the graphite structure. The aim of the research presented last year and updated here is to identify the chemical form of C-14 in irradiated graphite and develop a practical method by which C-14 can be removed. A nuclear-grade graphite, NBG-18, and a high-surface-area graphite foam, POCOFoam{sup R}, were exposed to liquid nitrogen (to increase the quantity of C-14 precursor) and neutron-irradiated (10{sup 13} neutrons/cm{sup 2}/s). Finer grained NBG-25 was not exposed to liquid nitrogen prior to irradiation at a neutron flux on the order of 10{sup 14} /cm{sup 2}/s. Characterization of pre- and post-irradiation graphite was conducted to determine the chemical environment and quantity of C-14 and its precursors via the use of surface sensitive characterization techniques. Scanning Electron Microscopy (SEM) was used to evaluate the morphological features of graphite samples. The concentration, chemical composition, and bonding characteristics of C-14 and its precursors were determined through X-ray Photoelectron Spectroscopy (XPS), Time-of-Flight Secondary Ion Mass Spectrometry (SIMS), and Energy Dispersive X-ray Analysis Spectroscopy (EDX). Results of post-irradiation characterization of these materials indicate a variety of surface functional groups containing carbon, oxygen, nitrogen and hydrogen. During thermal treatment, irradiated graphite samples are heated in the presence of an inert carrier gas (with or without oxidant gas), which carries off gaseous products released during treatment. Graphite gasification occurs via interaction with adsorbed oxygen complexes. Experiments in argon were performed at 900 deg. C and 1400 deg. C to evaluate the selective removal of C-14. Thermal treatment also was performed with the addition of 3 and 5 volume % oxygen at temperatures 700 deg. C and 1400 deg. C. Thermal treatment experiments were evaluated for the effective selective removal of C-14. Lower temperatures and oxygen levels correlated to more efficient C-14 removal. (authors)

Dunzik-Gougar, Mary Lou; Cleaver, James; LaBrier, Daniel; McCrory, Shilo; Smith, Tara E. [Idaho State University: 1776 Science Center Dr., Idaho Falls, ID, 83401 (United States)] [Idaho State University: 1776 Science Center Dr., Idaho Falls, ID, 83401 (United States)

2013-07-01T23:59:59.000Z

208

Method of producing exfoliated graphite composite compositions for fuel cell flow field plates  

DOE Patents [OSTI]

A method of producing an electrically conductive composite composition, which is particularly useful for fuel cell bipolar plate applications. The method comprises: (a) providing a supply of expandable graphite powder; (b) providing a supply of a non-expandable powder component comprising a binder or matrix material; (c) blending the expandable graphite with the non-expandable powder component to form a powder mixture wherein the non-expandable powder component is in the amount of between 3% and 60% by weight based on the total weight of the powder mixture; (d) exposing the powder mixture to a temperature sufficient for exfoliating the expandable graphite to obtain a compressible mixture comprising expanded graphite worms and the non-expandable component; (e) compressing the compressible mixture at a pressure within the range of from about 5 psi to about 50,000 psi in predetermined directions into predetermined forms of cohered graphite composite compact; and (f) treating the so-formed cohered graphite composite to activate the binder or matrix material thereby promoting adhesion within the compact to produce the desired composite composition. Preferably, the non-expandable powder component further comprises an isotropy-promoting agent such as non-expandable graphite particles. Further preferably, step (e) comprises compressing the mixture in at least two directions. The method leads to composite plates with exceptionally high thickness-direction electrical conductivity.

Zhamu, Aruna; Shi, Jinjun; Guo, Jiusheng; Jang, Bor Z

2014-04-08T23:59:59.000Z

209

Appendix F Cultural Resources, Including  

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

Appendix F Appendix F Cultural Resources, Including Section 106 Consultation STATE OF CALIFORNIA - THE RESOURCES AGENCY EDMUND G. BROWN, JR., Governor OFFICE OF HISTORIC PRESERVATION DEPARTMENT OF PARKS AND RECREATION 1725 23 rd Street, Suite 100 SACRAMENTO, CA 95816-7100 (916) 445-7000 Fax: (916) 445-7053 calshpo@parks.ca.gov www.ohp.parks.ca.gov June 14, 2011 Reply in Reference To: DOE110407A Angela Colamaria Loan Programs Office Environmental Compliance Division Department of Energy 1000 Independence Ave SW, LP-10 Washington, DC 20585 Re: Topaz Solar Farm, San Luis Obispo County, California Dear Ms. Colamaria: Thank you for seeking my consultation regarding the above noted undertaking. Pursuant to 36 CFR Part 800 (as amended 8-05-04) regulations implementing Section

210

Estimation of graphite density and mechanical strength variation of VHTR during air-ingress accident  

SciTech Connect (OSTI)

An air-ingress accident in a Very High Temperature Gas-Cooled Reactor (VHTR) is anticipated to cause severe changes to graphite density and mechanical strength by an oxidation process that has many side effects. However, quantitative estimations have not yet been performed. This study focuses on predicting the changes in graphite density and mechanical strength via thermal hydraulic system analysis code. In order to analyze the change in graphite density, a simple graphite burn-off model was developed. The model is based on the similarities between a parallel electrical circuit and graphite oxidation. It was used to determine overall changes in the graphite’s geometry and density. The model was validated by comparing its results to experimental data that was obtained for several temperatures. In the experiment, cylindrically shaped graphite specimens were oxidized in an electrical furnace and the variations of its mass were measured against time. The experiment’s range covered temperatures between 6000C and 9000 C. Experimental data validated the model’s accuracy. Finally, the developed model along with other comprehensive graphite oxidation models was integrated into the VHTR system analysis code, GAMMA. GT-MHR 600 MWt reactor was selected as a reference reactor. Based on the calculation, the main oxidation process was observed 5.5 days after the accident when followed by natural convection. The core maximum temperature reached 16000 C, but never exceeded the maximum temperature criteria, 18000 C. However, the oxidation process did significantly decrease the density of bottom reflector, making it vulnerable to mechanical stress. The stress on the bottom reflector is greatly increased because it sustains the reactor core. The calculation proceeded until 11 days after the accident, resulting in an observed 4.5% decrease in density and a 25% reduction of mechanical strength.

Eung Soo Kim

2008-04-01T23:59:59.000Z

211

Intrinsic Route to Melt Fracture in Polymer Extrusion: AWeakly Nonlinear Subcritical Instability of Viscoelastic Poiseuille Flow  

E-Print Network [OSTI]

Intrinsic Route to Melt Fracture in Polymer Extrusion: AWeakly Nonlinear Subcritical Instability generic route to melt fracture via a weakly nonlinear subcritical instability of viscoelastic Poiseuille ``subcritical'') instability due to normal stress effects; this instability appears to make melt fracture

van Saarloos, Wim

212

Countries Gasoline Prices Including Taxes  

Gasoline and Diesel Fuel Update (EIA)

Countries (U.S. dollars per gallon, including taxes) Countries (U.S. dollars per gallon, including taxes) Date Belgium France Germany Italy Netherlands UK US 01/13/14 7.83 7.76 7.90 8.91 8.76 8.11 3.68 01/06/14 8.00 7.78 7.94 8.92 8.74 8.09 3.69 12/30/13 NA NA NA NA NA NA 3.68 12/23/13 NA NA NA NA NA NA 3.63 12/16/13 7.86 7.79 8.05 9.00 8.78 8.08 3.61 12/9/13 7.95 7.81 8.14 8.99 8.80 8.12 3.63 12/2/13 7.91 7.68 8.07 8.85 8.68 8.08 3.64 11/25/13 7.69 7.61 8.07 8.77 8.63 7.97 3.65 11/18/13 7.99 7.54 8.00 8.70 8.57 7.92 3.57 11/11/13 7.63 7.44 7.79 8.63 8.46 7.85 3.55 11/4/13 7.70 7.51 7.98 8.70 8.59 7.86 3.61 10/28/13 8.02 7.74 8.08 8.96 8.79 8.04 3.64 10/21/13 7.91 7.71 8.11 8.94 8.80 8.05 3.70 10/14/13 7.88 7.62 8.05 8.87 8.74 7.97 3.69

213

Graphite-ceramic rf Faraday-thermal shield and plasma limiter  

DOE Patents [OSTI]

The present invention is directed to a brazing procedure for joining a ceramic or glass material (e.g., Al/sub 2/O/sub 3/ or Macor) to graphite. In particular, the present invention is directed to a novel brazing procedure for the production of a brazed ceramic graphite product useful as a Faraday shield. The brazed ceramic graphite Faraday shield of the present invention may be used in Magnetic Fusion Devices (e.g., Princeton Large Torus Tokamak) or other high temperature resistant apparatus.

Hwang, D.L.Q.; Hosea, J.C.

1983-05-05T23:59:59.000Z

214

The role of hydrogen in room-temperature ferromagnetism at graphite surfaces  

SciTech Connect (OSTI)

We present a x-ray dichroism study of graphite surfaces that addresses the origin and magnitude of ferromagnetism in metal-free carbon. We find that, in addition to carbon {pi} states, also hydrogen-mediated electronic states exhibit a net spin polarization with significant magnetic remanence at room temperature. The observed magnetism is restricted to the top {approx}10 nm of the irradiated sample where the actual magnetization reaches {approx_equal} 15 emu/g at room temperature. We prove that the ferromagnetism found in metal-free untreated graphite is intrinsic and has a similar origin as the one found in proton bombarded graphite.

Ohldag, Hendrik

2011-08-12T23:59:59.000Z

215

Effect of oxidizing environment on the strength and oxidation kinetics of HTGR graphites. Part I. Reactivity and strength loss of H451, PGX and IG-11 graphites  

SciTech Connect (OSTI)

The effects of oxidizing atmosphere and temperature on the reactivities and strengths of PGX, H451, and IG-11 were examined. Preliminary measurements of the oxidation kinetics of these graphites in H/sub 2/O-, CO/sub 2/- and O/sub 2/-containing atmospheres indicated that the reactivities of H451 graphite toward O/sub 2/ and H/sub 2/O are quite similar to those of IG-11 graphite. The apparent activation energy for oxidation of these in O/sub 2/ were estimated to be approx. 175 kJ/mol while that in H/sub 2/O is probably approx. 200 kJ/mol. The apparent activation energy of IG-11 graphite oxidized in CO/sub 2/ is 255 +- 18 kJ/mol. PGX graphite was found to be quite variable in its reactivity toward H/sub 2/O. A linear dependence with (Fe) was determined, but other intrinsic properties were found to affect its absolute reactivity by as much as a factor of X50.

Eto, M.; Growcock, F.B.

1981-09-01T23:59:59.000Z

216

Assessment of ceramic coatings for metal fuel melting crucible  

SciTech Connect (OSTI)

The objective of this study is to develop a coating method and material for crucibles to prevent material interactions with the U-Zr/U-TRU-Zr fuels during the manufacturing of SFR fuels. Refractory coatings were applied to niobium substrates by vacuum plasma-spray coating method. Melt dipping tests conducted were the coated rods lowered into the fuel melt at 1600 C. degrees, and withdrawn and cooled outside the crucible in the inert atmosphere of the induction furnace. Melt dipping tests of the coated Nb rods indicated that plasma-sprayed Y{sub 2}O{sub 3} coating doesn't form significant reaction layer between fuel melt and coating layer. Melt dipping tests of the coated Nb rods showed that TiC, TaC, and Y{sub 2}O{sub 3} coatings exhibited the promising performance among other ceramic coatings. These materials could be promising candidate materials for the reusable melt crucible of metal fuel for SFR. In addition, in order to develop the vacuum plasma-spray coating method for re-usable crucible of metal fuel slugs to be overcome the issue of thermal expansion mismatch between coating material and crucible, various combinations of coating conditions were investigated to find the bonding effect on the substrate in pursuit of more effective ways to withstand the thermal stresses. It is observed that most coating methods maintained sound coating state in U-Zr melt. (authors)

Kim, Ki-Hwan; Song, Hoon; Kim, Jong-Hwan; Oh, Seok-Jin; Kim, Hyung-Tae; Lee, Chan-Bock [Korea Atomic Energy Research Institute, Yuseong, Daejeon 305-600 (Korea, Republic of)

2013-07-01T23:59:59.000Z

217

Vitrification of surrogate mixed wastes in a graphite electrode arc melter  

SciTech Connect (OSTI)

Demonstration tests for vitrifying mixed wastes and contaminated soils have been conducted using a small (800 kVA), industrial-scale, three-phase AC, graphite electrode furnace located at the Albany Research Center of the United States Bureau of Mines (USBM). The feed mixtures were non-radioactive surrogates of various types of mixed (radioactive and hazardous), transuranic-contaminated wastes stored and buried at the Idaho National Engineering Laboratory (INEL). The feed mixtures were processed with added soil from the INEL. Objectives being evaluated include (1) equipment capability to achieve desired process conditions and vitrification products for different feed compositions, (2) slag and metals tapping capability, (3) partitioning of transuranic elements and toxic metals among the furnace products, (4) slag, fume, and metal products characteristics, and (5) performance of the feed, furnace and air pollution control systems. The tests were successfully completed in mid-April 1995. A very comprehensive process monitoring, sampling and analysis program was included in the test program. Sample analysis, data reduction, and results evaluation are currently underway. Initial results indicate that the furnace readily processed around 20,000 lb of widely ranging feed mixtures at feedrates of up to 1,100 lb/hr. Continuous feeding and slag tapping was achieved. Molten metal was also tapped twice during the test program. Offgas emissions were efficiently controlled as expected by a modified air pollution control system.

Soelberg, N.R.; Chambers, A.G.; Ball, L. [and others

1995-11-01T23:59:59.000Z

218

Small Glass-Melting Furnaces for Clear, Tinted, and Specialized Glass  

Science Journals Connector (OSTI)

Data on the design and application areas of small-sized glass-melting furnaces for melting various-purpose glasses are supplied.

A. A. Dymov; V. A. Fedorova

2000-07-01T23:59:59.000Z

219

String melting in a photon bath  

SciTech Connect (OSTI)

We compute the decay rate of a metastable cosmic string in contact with a thermal bath by finding the instanton solution. The new feature is that this decay rate is found in the context of non thermal scalar fields in contact with a thermal bath of photons. In general, to make topologically unstable strings stable, one can couple them to such a bath. The resulting plasma effect creates metastable configurations which can decay from the false vacuum to the true vacuum. In our specific set-up, the instanton computation is realized for the case of two out-of-equilibrium complex scalar fields: one is charged and coupled to the photon field, and the other is neutral. New effects coming from the thermal bath of photons make the radius of the nucleated bubble and most of the relevant physical quantities temperature-dependent. However, the temperature appears in a different way than in the purely thermal case, where all scalar fields are in thermal equilibrium. As a result of the tunneling, the core of the initial string melts while bubbles of true vacuum expand at the speed of light.

Karouby, Johanna, E-mail: karoubyj@mit.edu [Center for Theoretical Physics and Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachussetts 02139 (United States)

2013-10-01T23:59:59.000Z

220

Atomistic modeling of femtosecond laser-induced melting and atomic mixing in Au film Cu substrate system  

E-Print Network [OSTI]

, including laser surface alloying, cladding, annealing, and hardening, e.g. [1­6]. The improvement of surfaceAtomistic modeling of femtosecond laser-induced melting and atomic mixing in Au film ­ Cu substrate modification by laser irradiation is in the core of many modern processing and fabrication techniques

Zhigilei, Leonid V.

Note: This page contains sample records for the topic "melting includes graphite" 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

Energy Efficient Glass Melting - The Next Generation Melter  

SciTech Connect (OSTI)

The objective of this project is to demonstrate a high intensity glass melter, based on the submerged combustion melting technology. This melter will serve as the melting and homogenization section of a segmented, lower-capital cost, energy-efficient Next Generation Glass Melting System (NGMS). After this project, the melter will be ready to move toward commercial trials for some glasses needing little refining (fiberglass, etc.). For other glasses, a second project Phase or glass industry research is anticipated to develop the fining stage of the NGMS process.

David Rue

2008-03-01T23:59:59.000Z

222

Method for Synthesizing Extremeley High Temperature Melting Materials  

DOE Patents [OSTI]

The invention relates to a method of synthesizing high-temperature melting materials. More specifically the invention relates to a containerless method of synthesizing very high temperature melting materials such as borides, carbides and transition-metal, lanthanide and actinide oxides, using an Aerodynamic Levitator and a laser. The object of the invention is to provide a method for synthesizing extremely high-temperature melting materials that are otherwise difficult to produce, without the use of containers, allowing the manipulation of the phase (amorphous/crystalline/metastable) and permitting changes of the environment such as different gaseous compositions.

Saboungi, Marie-Louise and Glorieux, Benoit

2005-11-22T23:59:59.000Z

223

Method For Synthesizing Extremely High-Temperature Melting Materials  

DOE Patents [OSTI]

The invention relates to a method of synthesizing high-temperature melting materials. More specifically the invention relates to a containerless method of synthesizing very high temperature melting materials such as borides, carbides and transition-metal, lanthanide and actinide oxides, using an Aerodynamic Levitator and a laser. The object of the invention is to provide a method for synthesizing extremely high-temperature melting materials that are otherwise difficult to produce, without the use of containers, allowing the manipulation of the phase (amorphous/crystalline/metastable) and permitting changes of the environment such as different gaseous compositions.

Saboungi, Marie-Louise (Chicago, IL); Glorieux, Benoit (Perpignan, FR)

2005-11-22T23:59:59.000Z

224

Method for synthesizing extremely high-temperature melting materials  

SciTech Connect (OSTI)

The invention relates to a method of synthesizing high-temperature melting materials. More specifically the invention relates to a containerless method of synthesizing very high temperature melting materials such as carbides and transition-metal, lanthanide and actinide oxides, using an aerodynamic levitator and a laser. The object of the invention is to provide a method for synthesizing extremely high-temperature melting materials that are otherwise difficult to produce, without the use of containers, allowing the manipulation of the phase (amorphous/crystalline/metastable) and permitting changes of the environment such as different gaseous compositions.

Saboungi, Marie-Louise (Chicago, IL); Glorieux, Benoit (Perpignan, FR)

2007-11-06T23:59:59.000Z

225

Phenomenological model for a novel melt-freeze phase of sliding bilayers  

E-Print Network [OSTI]

Simulations show that sliding bilayers of colloidal particles can exhibit a new phase, the ``melt-freeze'' phase, where the layers stochastically alternate between solidlike and liquidlike states. We introduce a mean field phenomenological model with two order parameters to understand the interplay of two adjacent layers while the system is in this remarkable phase. Predictions from our numerical simulations of a system in the melt-freeze phase include the tendency of two adjacent layers to be in opposite states (solid and liquid) and the difference between the fluctuation of the order parameter in one layer while the other layer is in the same phase compared to the fluctuation while the other layer is in the opposite phase. We expect this behavior to be seen in future simulations and experiments.

Trieu Mai

2006-01-31T23:59:59.000Z

226

Low-cost and durable catalyst support for fuel cells: graphite submicronparticles  

SciTech Connect (OSTI)

Low-cost graphite submicronparticles (GSP) are employed as a possible catalyst support for polymer electrolyte membrane (PEM) fuel cells. Platinum nanoparticles are deposited on Vulcan XC-72 carbon black (XC-72), carbon nanotubes (CNT), and GSP via ethylene glycol (EG) reduction method. The morphologies and the crystallinity of Pt/XC-72, Pt/CNT, and Pt/GSP are characterized with X-ray diffraction and transmission electron microscope, which shows that Pt nanoparticles (~ 3.5 nm) are uniformly dispersed on GSP support. Pt/GSP exhibits the highest activity towards oxygen reduction reactions. The durability study indicates that Pt/GSP is 2 ~ 3 times durable than Pt/CNT and Pt/XC-72. The enhanced durability of Pt/GSP catalyst is attributed to the higher corrosion resistance of graphite submicronparticles, which results from higher graphitization degree of GSP support. Considering its low production cost, graphite submicronparticles are promising electrocatalyst support for fuel cells.

Zhang, Sheng; Shao, Yuyan; Li, Xiaohong; Nie, Zimin; Wang, Yong; Liu, Jun; Yin, Geping; Lin, Yuehe

2010-01-01T23:59:59.000Z

227

The addition of a calender machine to a pyrolytic graphite sheet production plant  

E-Print Network [OSTI]

This thesis documents the process and challenges of adding a new calender machine to AvCarb Material Solutions' pyrolytic graphite production plant. Before the machine could be used for mass production, several experiments ...

Svenson, Ernest Knute

2014-01-01T23:59:59.000Z

228

Induced crystallization of single-chain polyethylene on a graphite surface: Molecular dynamics simulation  

Science Journals Connector (OSTI)

Molecular dynamics (MD) simulations have been carried out on the crystallization of single-chain polyethylene (PE) which was adsorbed on a graphite (001) surface on one side and exposed to vacuum on the other at different temperatures. The MD simulation data have been analyzed to provide information about the crystallization process of polymer adsorbed on the solid substrate. The isothermal crystallization of PE proceeds in two steps: (1) adsorption and (2) orientation. The results detail the radial density distribution function, ordered parameters, local bond-orientational order parameters, and the local properties displayed in layers of the polymer parallel to the graphite and vacuum interfaces. It was also shown that the film thickness affected the critical crystallization temperature of the adsorbed polymer on the substrate surface. Furthermore, the influence of the graphite surface area on the crystallization of PE is discussed by comparing the crystallinity evolution of PE on graphite with different coverage.

Hua Yang (??); Xiao Jun Zhao (???); Miao Sun (??)

2011-07-14T23:59:59.000Z

229

Loop formation in graphitic nanoribbon edges using furnace heating or Joule heating  

E-Print Network [OSTI]

Here the authors report the use of either furnace heating or Joule heating to pacify the exposed graphene edges by loop formation in a novel graphitic nanoribbonmaterial, grown by chemical vapor deposition. The edge energy ...

Jia, Xiaoting

230

The effects of marine microorganisms on the mechanical properties of graphite/epoxy composites  

E-Print Network [OSTI]

with two different lay-ups were conditioned in natural seawater and then tensile tested while simultaneously monitored for acoustic emission activity. Graphite/epoxy composite specimens were fabricated from prepreg tape and then conditioned for 4 and I I...

Puh, John Shui-Ming

2012-06-07T23:59:59.000Z

231

Identification of structural defects in graphitic materials by gas-phase anisotropic etching  

E-Print Network [OSTI]

Identification of structural defects in graphitic materials by gas-phase anisotropic etching Shuang interest but also industrial importance, as the existence of surface and bulk defects inevitably influences

Zhang, Guangyu

232

Electrochromic polyaniline/graphite oxide nanocomposites with endured electrochemical energy storage  

E-Print Network [OSTI]

Electrochromic polyaniline/graphite oxide nanocomposites with endured electrochemical energy February 2013 Keywords: Polyaniline nanocomposite film Electropolymerization Electrochromism a b s t r a c films for electrochromic displays and electrochemical energy storage devices applications were

Guo, John Zhanhu

233

Partially graphitic, high-surface-area mesoporous carbons from polyacrylonitrile templated by ordered and disordered  

E-Print Network [OSTI]

, and manufacturing of electrochemical dou- ble-layer capacitors and Li-ion batteries. Graphitic carbons exhibit structures with an appreciable degree of ordering of graphene sheets typi- cally form as a result of a heat

234

THE USE OF THE ELECTRICAL CONDUCTIVITY OF GRAPHITE AS A RADIATION...  

Office of Scientific and Technical Information (OSTI)

THE USE OF THE ELECTRICAL CONDUCTIVITY OF GRAPHITE AS A RADIATION DAMAGE AND FLUX MONITOR. IMPLICATIONS OF THE RESULTS TO THE GENERAL THEORY OF RADIATION DAMAGE Re-direct...

235

Low Cost SiOx-Graphite and High Voltage Spinel Cathode | Department...  

Office of Environmental Management (EM)

Cathode Low Cost SiOx-Graphite and High Voltage Spinel Cathode 2011 DOE Hydrogen and Fuel Cells Program, and Vehicle Technologies Program Annual Merit Review and Peer Evaluation...

236

Low Cost SiOx-Graphite and Olivine Materials | Department of...  

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

May 18-22, 2009 -- Washington D.C. es19zaghib.pdf More Documents & Publications Low Cost SiOx-Graphite and Olivine Materials Phase Behavior and Solid State Chemistry in Olivines...

237

Oxidation of hydrocarbons over ordered arrays of heteropolyacids and polyoxoanions on graphite  

DOE Patents [OSTI]

Alkanes are catalytically oxidized using heteropolyacids (HPAs) or polyoxoanions (POAs) deposited on a graphite surface. The HPAs and POAs are framework-substituted with a different metal in place of a metal-oxygen unit.

Shaikh, Shahid N. (Media, PA); Ellis, Jr., Paul E. (Downingtown, PA); Lyons, James E. (Wallingford, PA)

1994-01-01T23:59:59.000Z

238

Next Generation Nuclear Plant Phenomena Identification and Ranking Tables (PIRTs) Volume 5: Graphite PIRTs  

SciTech Connect (OSTI)

Here we report the outcome of the application of the Nuclear Regulatory Commission (NRC) Phenomena Identification and Ranking Table (PIRT) process to the issue of nuclear-grade graphite for the moderator and structural components of a next generation nuclear plant (NGNP), considering both routine (normal operation) and postulated accident conditions for the NGNP. The NGNP is assumed to be a modular high-temperature gas-cooled reactor (HTGR), either a gas-turbine modular helium reactor (GTMHR) version [a prismatic-core modular reactor (PMR)] or a pebble-bed modular reactor (PBMR) version [a pebble bed reactor (PBR)] design, with either a direct- or indirect-cycle gas turbine (Brayton cycle) system for electric power production, and an indirect-cycle component for hydrogen production. NGNP design options with a high-pressure steam generator (Rankine cycle) in the primary loop are not considered in this PIRT. This graphite PIRT was conducted in parallel with four other NRC PIRT activities, taking advantage of the relationships and overlaps in subject matter. The graphite PIRT panel identified numerous phenomena, five of which were ranked high importance-low knowledge. A further nine were ranked with high importance and medium knowledge rank. Two phenomena were ranked with medium importance and low knowledge, and a further 14 were ranked medium importance and medium knowledge rank. The last 12 phenomena were ranked with low importance and high knowledge rank (or similar combinations suggesting they have low priority). The ranking/scoring rationale for the reported graphite phenomena is discussed. Much has been learned about the behavior of graphite in reactor environments in the 60-plus years since the first graphite rectors went into service. The extensive list of references in the Bibliography is plainly testament to this fact. Our current knowledge base is well developed. Although data are lacking for the specific grades being considered for Generation IV (Gen IV) concepts, such as the NGNP, it is fully expected that the behavior of these graphites will conform to the recognized trends for near isotropic nuclear graphite. Thus, much of the data needed is confirmatory in nature. Theories that can explain graphite behavior have been postulated and, in many cases, shown to represent experimental data well. However, these theories need to be tested against data for the new graphites and extended to higher neutron doses and temperatures pertinent to the new Gen IV reactor concepts. It is anticipated that current and planned future graphite irradiation experiments will provide the data needed to validate many of the currently accepted models, as well as providing the needed data for design confirmation.

Burchell, Timothy D [ORNL; Bratton, Rob [Idaho National Laboratory (INL); Marsden, Barry [University of Manchester, UK; Srinivasan, Makuteswara [U.S. Nuclear Regulatory Commission; Penfield, Scott [Technology Insights; Mitchell, Mark [PBMR (Pty) Ltd.; Windes, Will [Idaho National Laboratory (INL)

2008-03-01T23:59:59.000Z

239

Residual thermal stresses in an unsymmetrical cross-ply graphite/epoxy laminate  

E-Print Network [OSTI]

RESIDUAL THERMAL STRESSES IN AN UNSYMMETRICAL CROSS-PLY GRAPHITE/EPOXY LAMINATE A Thesis by BRIAN DOUGLAS HARPER Submitted to the Graduate College of Texas A&M University in parrial fulfillment of the requirement for the degree of MASTER... OF SCIENCE August 1980 Major Subject: Mechanical Engineering RESIDUAL THERMAL STRESSES IN AN UNSYMMETRICAL CROSS-PLY GRAPHITE/EPOXY LAMINATE A Thesis by BRIAN DOUGLAS HARPER Approved as to style and content by: r. Y. N itsman (Chair of Committee) Dr...

Harper, Brian Douglas

2012-06-07T23:59:59.000Z

240

First-order wetting transition in CF4 solid films adsorbed on the (0001) graphite surface  

E-Print Network [OSTI]

1497 First-order wetting transition in CF4 solid films adsorbed on the (0001) graphite surface J. M films de CF4 condens�s sur la face de clivage d'un monocristal de graphite a �t� observ�e par transition de mouillage du premier ordre � 37 K, une temp�rature bien en dessous du point triple de CF4

Paris-Sud XI, Université de

Note: This page contains sample records for the topic "melting includes graphite" 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

Effect of resin toughness on fracture behavior of graphite/epoxy composites  

E-Print Network [OSTI]

EFFECT OF RESIN TOUGHNESS ON FRACTURE BEHAVIOR OF GRAPHITE/EPOXY COMPOSITES A Thesis Dy RONALD NELSON COHEN Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirement for the degree of MASTER... OF SCIENCE December 1982 Mlajor Subject: Interdisciplinary Enqi neeri ng EFFECT OF RESIN TOUGHNESS ON FRACTURE BEHAVIOR OF GRAPHITE/EPOXY COMPOSITES A Thesis by RONALD NELSON COHEN Approved as to style and content by: (N. L. Bradley, Cha man) (R. A...

Cohen, Ronald Nelson

2012-06-07T23:59:59.000Z

242

Nonlinear viscoelastic characterization of AS-3502 graphite/epoxy composite material  

E-Print Network [OSTI]

NONLINEAR VISCOELASTIC CHARACTERIZATION OF AS-3502 GRAPHITE/EPOXY COMPOSITE MATERIAL A Thesis MICHAEL SCOTT KERSTETTER Submitted to the Graduate College of Texas A8M University in partial fulfillment of the requirement for the degree... of MASTER OF SCIENCE December 1980 Major Subject: Aerospace Engineering NONLINEAR VISCOELASTIC CHARACTERIZATION OF AS-3502 GRAPHITE/EPOXY COMPOSITE MATERIAL A Thesis by MICHAEL SCOTT KERSTETTER Approved as to style and content by: Dr. Kenneth L...

Kerstetter, Michael Scott

2012-06-07T23:59:59.000Z

243

Nondestructive evaluation of distributed damage in graphite/epoxy beams using modal parameters  

E-Print Network [OSTI]

NONDESTRUCTIVE EVALUATIOV OF DISTRIBUTED DAMAGE IN GRAPHITE/EPOXY BEAMS USING MODAL PARAMETERS A Thesis YOUNG IK KIM Submitted to the Office of Graduate Studies of Texas AkM University in partial fulfillment of the requirement for the degree... of ItIASTER OF SCIEVCE August 1989 Major Subject: Aerospace Engineering NONDESTRI. 'CTIVE EVALUATION OF DISTRIBUTED DAMAGE IN GRAPHITE/EPOXY BEAMS USING MODAL PARAMETERS A Thesis by YOUNG IK KIM Approved as to style and content by: Duane R...

Kim, Young Ik

2012-06-07T23:59:59.000Z

244

Measurements of the diffusion coefficient of silver 110-m in a nuclear grade graphite  

E-Print Network [OSTI]

MEASUREMENTS OF TEE DIFFUSION COEFFICIENT OF SILVER 110-m IN A NUCLEAR GRADE. GRAPHITE A Thesis by THAD CALHOUN MCMILLAN, Jr. Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree... of MASTER OF SCIENCE August 1980 Major Subject: Nuclear Engineering MEASUREMENTS OF THE DIFFUSION COEFFICIENT OF SILVER 110-m IN A NUCLEAR GRADE GRAPHITE A Thesis by THAD CALHOUN MCMILLAN, Jr. Approved as to style and content by: (Chairman...

McMillan, Thad Calhoun

2012-06-07T23:59:59.000Z

245

The effect of graphite nodules on fracture behavior of ductile iron  

E-Print Network [OSTI]

THE EFFECT OF GRAPHITE NODULES ON FRACTURE BEHAVIOR OF DUCTILE IRON A Thesis By GLENN NARK TANNER Suhmitted to the Graduate College of Texas A&K University in partial fulfillment of the requirements for the degree of RASTER OF SCIENCE Nay... 1986 Kajor Subject: Nechanical Engineering THE EFFECT OF GRAPHITE NODULES ON FRACTURE BEHAVIOR OF DUCTILE IRON A Thesis by GLENN MARK TANNER Approved as to style and content by: Halter L. Bradley (Chairman of Committee) pl...

Tanner, Glenn Mark

2012-06-07T23:59:59.000Z

246

Mode II delamination fracture toughness of unidirectional graphite/epoxy composites  

E-Print Network [OSTI]

MODE II DELAMINATION FRACTURE TOUGHNESS OF UNIDIRECTIONAL GRAPHITE/EPOXY COMPOSITES A Thesis by CARLOS ROBERTO CORLETO MENA Submitted to the Graduate College of TEXAS ASM UNIVERSITY in partial fulfillment of the requirement for the degree... of MASTER OF SCIENCE August 1986 Major Subject: Mechanical Engineering MODE II DELAMINATION FRACTURE TOUGHNESS OF UNIDIRECTIONAL GRAPHITE/EPOXY COMPOSITES A Thesis by CARLOS ROBERTO CORLETO MENA Approved as to style and content by: Walter L. Bra...

Corleto Mena, Carlos Roberto

2012-06-07T23:59:59.000Z

247

Mode I - mode II delamination fractrue toughness of a unidirectional graphite/epoxy composite  

E-Print Network [OSTI]

MODE I - MODE II DELAMINATION FRACTURE TOUGHNESS OF A UNIDIRECTIONAL GRAPHITE/EPOXY COMPOSITE A Thesis by PETER STEPHEN VANDERKLEY Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirement... for the degree of MASTER OF SCIENCE Demember 1981 Najor Subject: Mechanical Engineering MODE I - MODE II DELAMINATION FRACTURE TOUGHNESS OF A UNIDIRECTIONAL GRAPHITE/EPOXY COMPOSITE A Thesis by PETER STEPHEN VANDERKLEY Approved as to style and content by...

Vanderkley, Peter Stephen

2012-06-07T23:59:59.000Z

248

Graphite Furnance Atomic Absorption as a detector for High Performance Liquid Chromatography  

E-Print Network [OSTI]

GRAPHITE FURNACE ATOMIC ABSORPTION AS A DETECTOR FOR HIGH PERFORMANCE LIQUID CHROMATOGRAPHy A Thesis by HUSTON EDWARD HOWELL, JR. Submitted to the Graduate College oi' Texas A&M University in partial fulfillment of the requirement... for the degree of MASTER OF SCIENCE August 1980 Major Subject: Chemistry GRAPHITE FURNACE ATOMIC ABSORPTION AS A DETECTOR FOR HIGH PERFORMANCE LIQUID CHROMATOGRAPHY A Thesis by HUSTON EDWARD HOWELL, JR. Approved as to style and content by: (Chairman...

Howell, Huston Edward

1980-01-01T23:59:59.000Z

249

Melt generation in the Earth's mantle at Convergent Plate Margins  

E-Print Network [OSTI]

The five geologic studies presented in this thesis document how the recycling of tectonic plates at subduction zones has a profound effect on the melting behavior of the Earth's mantle. Two experimental studies (Chapters ...

Till, Christy B

2011-01-01T23:59:59.000Z

250

Plasma of Electric Arc Discharge between Melted Electrodes  

Science Journals Connector (OSTI)

Plasma of electric arc discharge between melted electrodes was experimentally investigated. Diagnostics of electric arc plasma was carried out. Optical emission and ... in plasma tends to be located at the arc ax...

A.N. Veklich; I.L. Babich

2001-01-01T23:59:59.000Z

251

Graphite Materials Testing in the ATR for Lifetime Management of Magnox Reactors  

SciTech Connect (OSTI)

A major feature of the Magnox gas cooled reactor design is the graphite core, which acts as the moderator but also provides the physical structure for fuel, control rods, instrumentation and coolant gas channels. The lifetime of a graphite core is dependent upon two principal aging processes: irradiation damage and radiolytic oxidation. Irradiation damage from fast neutrons creates lattice defects leading to changes in physical and mechanical properties and the accumulation of stresses. Radiolytic oxidation is caused by the reaction of oxidizing species from the carbon dioxide coolant gas with the graphite, these species being produced by gamma radiation. Radiolytic oxidation reduces the density and hence the moderating capability of the graphite, but also reduces strength affecting the integrity of core components. In order to manage continued operation over the planned lifetimes of their power stations, BNFL needed to extend their database of the effects of these two phenomena on the ir graphite cores through an irradiation experiment. This paper will discuss the background, purpose, and the processes taken and planned (i.e. post irradiation examination) to ensure meaningful data on the graphite core material is obtained from the irradiation experiment.

Grover, S.B. (INEEL); Metcalfe, M.P. (BNFL, United Kingdom)

2002-03-14T23:59:59.000Z

252

Graphite Materials Testing in the ATR for Lifetime Management of Magnox Reactors  

SciTech Connect (OSTI)

A major feature of the Magnox gas cooled reactor design is the graphite core, which acts as the moderator but also provides the physical structure for fuel, control rods, instrumentation and coolant gas channels. The lifetime of a graphite core is dependent upon two principal aging processes: irradiation damage and radiolytic oxidation. Irradiation damage from fast neutrons creates lattice defects leading to changes in physical and mechanical properties and the accumulation of stresses. Radiolytic oxidation is caused by the reaction of oxidizing species from the carbon dioxide coolant gas with the graphite, these species being produced by gamma radiation. Radiolytic oxidation reduces the density and hence the moderating capability of the graphite, but also reduces strength affecting the integrity of core components. In order to manage continued operation over the planned lifetimes of their power stations, BNFL needed to extend their database of the effects of these two phenomena on their graphite cores through an irradiation experiment. This paper will discuss the background, purpose, and the processes taken and planned (i.e. post irradiation examination) to ensure meaningful data on the graphite core material is obtained from the irradiation experiment.

Grover, Stanley Blaine; Metcalfe, M. P.

2002-04-01T23:59:59.000Z

253

Velocity of sound in solid methane near melting temperatures  

E-Print Network [OSTI]

VELOCITY OF SOUND IN SOLID METHANE NEAR MELTING TEMPERATURES A Thesis By JOHN MARTIN WHITEHEAD Submitted to the Graduate College of the Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE May... 1968 Ma)or Sub)ect: Physics VELOCITY OF SOVND IN SOLID METHANE NEAR MELTING TEMPERATURES A Thesis By JOHN MARTIN WHITEHEAD Approved as to style and content by& (Chairman of Committee) (Head of Departsmnt) (Mem er (Member) May 1968...

Whitehead, John Martin

2012-06-07T23:59:59.000Z

254

Method and apparatus for melt growth of crystalline semiconductor sheets  

DOE Patents [OSTI]

An economical method is presented for forming thin sheets of crystalline silicon suitable for use in a photovoltaic conversion cell by solidification from the liquid phase. Two spatially separated, generally coplanar filaments wettable by liquid silicon and joined together at the end by a bridge member are immersed in a silicon melt and then slowly withdrawn from the melt so that a silicon crystal is grown between the edge of the bridge and the filaments.

Ciszek, T.F.; Hurd, J.L.

1981-02-25T23:59:59.000Z

255

Apparatus for melt growth of crystalline semiconductor sheets  

DOE Patents [OSTI]

An economical method is presented for forming thin sheets of crystalline silicon suitable for use in a photovoltaic conversion cell by solidification from the liquid phase. Two spatially separated, generally coplanar filaments wettable by liquid silicon and joined together at the end by a bridge member are immersed in a silicon melt and then slowly withdrawn from the melt so that a silicon crystal is grown between the edge of the bridge and the filaments.

Ciszek, Theodore F. (Evergreen, CO); Hurd, Jeffery L. (Golden, CO)

1986-01-01T23:59:59.000Z

256

Creep measuring device for low melting point metals  

E-Print Network [OSTI]

CREEP MEASURING DEVICE FOR LOW MELTING POINT METALS A Thesis MARC-EMMANUEL GILBERT PORTAL Submitted to the Graduate College of Texas AA;M University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE May 1987... Major Subject: Nuclear Engineering CREEP MEASURING DEVICE FOR LOW MELTING POINT METALS A Thesis MARC-EMMANUEL GILBERT PORTAL Approved as to style and content by: K. L. Peddicord (Chairman of Committee) C. A. Erdman (Member) F. R. Best (Member...

Portal, Marc-Emmanuel Gilbert

1987-01-01T23:59:59.000Z

257

Characterization of electron beam melted uranium - 6% niobium ingots  

SciTech Connect (OSTI)

A study was undertaken at Lawrence Livermore National Laboratory to characterize uranium, 6{percent} niobium ingots produced via electron beam melting,hearth refining and continuous casting and to compare this material with conventional VIM/skull melt /VAR material. Samples of both the ingot and feed material were analyzed for niobium, trace metallic elements, carbon, oxygen and nitrogen. Ingot samples were also inspected metallographically and via microprobe analysis.

McKoon, R.H.

1997-10-31T23:59:59.000Z

258

EFFECTS OF GRAPHITE SURFACE ROUGHNESS ON BYPASS FLOW COMPUTATIONS FOR AN HTGR  

SciTech Connect (OSTI)

Bypass flow in a prismatic high temperature gas reactor (HTGR) occurs between graphite blocks as they sit side by side in the core. Bypass flow is not intentionally designed to occur in the reactor, but is present because of tolerances in manufacture, imperfect installation and expansion and shrinkage of the blocks from heating and irradiation. It is desired to increase the knowledge of the effects of such flow, which has been estimated to be as much as 20% of the total helium coolant flow. Computational fluid dynamic (CFD) simulations can provide estimates of the scale and impacts of bypass flow. Previous CFD calculations have examined the effects of bypass gap width, level and distribution of heat generation and effects of shrinkage. The present contribution examines the effects of graphite surface roughness on the bypass flow for different relative roughness factors on three gap widths. Such calculations should be validated using specific bypass flow measurements. While such experiments are currently underway for the specific reference prismatic HTGR design for the next generation nuclear plant (NGNP) program of the U. S. Dept. of Energy, the data are not yet available. To enhance confidence in the present calculations, wall shear stress and heat transfer results for several turbulence models and their associated wall treatments are first compared for flow in a single tube that is representative of a coolant channel in the prismatic HTGR core. The results are compared to published correlations for wall shear stress and Nusselt number in turbulent pipe flow. Turbulence models that perform well are then used to make bypass flow calculations in a symmetric onetwelfth sector of a prismatic block that includes bypass flow. The comparison of shear stress and Nusselt number results with published correlations constitutes a partial validation of the CFD model. Calculations are also compared to ones made previously using a different CFD code. Results indicate that increasing surface roughness increases the maximum fuel and helium temperatures as do increases in gap width. However, maximum coolant temperature variation due to increased gap width is not changed by surface roughness.

Rich Johnson; Yu-Hsin Tung; Hiroyuki Sato

2011-07-01T23:59:59.000Z

259

Photonically excited electron emission from modified graphitic nanopetal arrays  

SciTech Connect (OSTI)

Efficient electron emission for energy conversion requires a low work function and a stable emitter material. The work function of graphene-based carbon materials can decrease significantly by intercalation with alkali metals, thus increasing their emission current. In this work, electron emission from potassium-intercalated carbon nanosheet extensions grown on electrode graphite is investigated. These petal-like structures, composed of 5-25 layers of graphene, are synthesized using microwave plasma chemical vapor deposition. Samples are intercalated with potassium, and a hemispherical energy analyzer is used to measure the emission intensity caused by both thermal and photonic excitation. The emission from the potassium-intercalated structures is found to consistently decrease the work function by 2.4 to 2.8 eV relative to non-intercalated samples. High emission intensity induced by photonic excitation from a solar simulator, with a narrow electron energy distribution relative to established theory, suggests that electron scattering decreases emitted electron energy as compared to surface photoemission. A modified photoemission theory is applied to account for electron scattering, and the sample work function and mean number of scattering events are used as parameters to fit theory to experimental data. The thermal stability of the intercalated nanopetals is investigated, and after an initial heating and cooling cycle, the samples are stable at low temperatures.

McCarthy, Patrick T.; Fisher, Timothy S. [Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States) [Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States); School of Mechanical Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); Vander Laan, Scott J.; Janes, David B. [Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States) [Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States); School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907 (United States)

2013-05-21T23:59:59.000Z

260

Evidence of Graphitic AB Stacking Order of Graphite Oxides Hae-Kyung Jeong,*, Yun Pyo Lee, Rob J. W. E. Lahaye, Min-Ho Park,  

E-Print Network [OSTI]

Machinery Research Center, Jeonju 561-844, Battery Research Group, Korea Electrotechnology Research this simplified Brodie method is further discussed. I. Introduction Graphene sheets have extraordinary electronic of polymer-coated graphene-based sheets have been prepared via exfoliation of graphite oxide (GO) in water

Note: This page contains sample records for the topic "melting includes graphite" 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

Dynamics of crystallization from segregated block copolymer melts  

SciTech Connect (OSTI)

Microphase separation in semicrystalline block copolymers can be driven by two forces: thermodynamic incompatibility between blocks or crystallization of one or more blocks. Prior work has demonstrated that when the block incompatibility is small, crystallization occurs from a single-phase melt and alternating lamellar microdomains result regardless of the copolymer composition. Several experimental studies have examined the time-resolved process of crystallization from single-phase melts. An added complexity in the case of semicrystalline block copolymers which have large block incompatibilities is the possible formation of an ordered melt mesophase; the presence of these microdomains may affect the crystallization process and the resultant morphology. A number of studies have investigated time-resolved crystallization from weakly segregated diblock copolymer melts, concluding that crystallization destroys any pre-existing melt microstructure resulting in a lamellar morphology. We recently reported the statically determined crystallization results for a series of ethylene-block-(3-methyl-1-butene) polymers, which will be referred to as E/MB`s. The composition of each of the polymers in the series was held constant at {approx}26 wt. % E (f{sub E}) block to produce hexagonally packed cylindrical melts, while the molecular weights were altered to obtain varying degrees of incompatibility. Through static scattering measurements, we have clearly shown that a strongly segregated cylindrical melt can confine crystallization to the pre-established microdomains under ordinary processing conditions. In this work, combined synchrotron-based SAXS and WAXS are employed to dynamically follow the microphase separation and crystallization in these materials at both the unit cell and microdomain scales.

Quiram, D.J.; Register, R.A. [Princeton Univ., NJ (United States); Marchand, G.R. [Dow Chemical Co., Plaquemine, LA (United States); Ryan, A.J. [Univ. of Manchester Institute of Science and Technology, MI (United States)

1996-12-31T23:59:59.000Z

262

Laminated exfoliated graphite composite-metal compositions for fuel cell flow field plate or bipolar plate applications  

DOE Patents [OSTI]

An electrically conductive laminate composition for fuel cell flow field plate or bipolar plate applications. The laminate composition comprises at least a thin metal sheet having two opposed exterior surfaces and a first exfoliated graphite composite sheet bonded to the first of the two exterior surfaces of the metal sheet wherein the exfoliated graphite composite sheet comprises: (a) expanded or exfoliated graphite and (b) a binder or matrix material to bond the expanded graphite for forming a cohered sheet, wherein the binder or matrix material is between 3% and 60% by weight based on the total weight of the first exfoliated graphite composite sheet. Preferably, the first exfoliated graphite composite sheet further comprises particles of non-expandable graphite or carbon in the amount of between 3% and 60% by weight based on the total weight of the non-expandable particles and the expanded graphite. Further preferably, the laminate comprises a second exfoliated graphite composite sheet bonded to the second surface of the metal sheet to form a three-layer laminate. Surface flow channels and other desired geometric features can be built onto the exterior surfaces of the laminate to form a flow field plate or bipolar plate. The resulting laminate has an exceptionally high thickness-direction conductivity and excellent resistance to gas permeation.

Zhamu, Aruna; Shi, Jinjun; Guo, Jiusheng; Jang, Bor Z

2014-05-20T23:59:59.000Z

263

Application of a SeaWinds/QuikSCAT sea ice melt algorithm for assessing melt dynamics in the Canadian Arctic Archipelago  

E-Print Network [OSTI]

Application of a SeaWinds/QuikSCAT sea ice melt algorithm for assessing melt dynamics] A remotely sensed sea ice melt algorithm utilizing SeaWinds/QuikSCAT (QuikSCAT) data is developed and applied resolution radiometer Polar Pathfinder (APP-x) data set is used to identify spatially coupled relationships

264

Ising model for melt ponds on Arctic sea ice  

E-Print Network [OSTI]

The albedo of melting Arctic sea ice, a key parameter in climate modeling, is determined by pools of water on the ice surface. Recent observations show an onset of pond complexity at a critical area of about 100 square meters, attended by a transition in pond fractal dimension. To explain this behavior and provide a statistical physics approach to sea ice modeling, we introduce a two dimensional Ising model for pond evolution which incorporates ice-albedo feedback and the underlying thermodynamics. The binary magnetic spin variables in the Ising model correspond to the presence of melt water or ice on the sea ice surface. The model exhibits a second-order phase transition from isolated to clustered melt ponds, with the evolution of pond complexity in the clustered phase consistent with the observations.

Ma, Y -P; Golden, K M

2014-01-01T23:59:59.000Z

265

Transient rheology of a polyethylene melt under shear  

SciTech Connect (OSTI)

Using nonequilibrium molecular dynamics simulation, we have studied the response of a C{sub 100} model polymer melt to a step change from equilibrium to a constant, high shear rate flow. The transient shear stress of the model polymer melt exhibits pronounced overshoot at the strain value predicted by the reptation model, in striking similarity to melts of longer, entangled polymer governed by reptation motion. At the maximum of shear stress overshoot, the molecular orientational order and the alignment angle are found to be midway between those characteristic of Newtonian flow and full alignment with the flow. The Doi-Edwards theory is found to be applicable but only by taking into account the shear-rate-dependence of the terminal relaxation time. We further analyze the molecular origins of such behavior in short polymer chains by decomposing the total stress into the contributions from various molecular interactions. (c) 1999 The American Physical Society.

Moore, J. D. [Department of Chemical Engineering, University of Tennesee, Knoxville, Tennessee 37996-2200 (United States) [Department of Chemical Engineering, University of Tennesee, Knoxville, Tennessee 37996-2200 (United States); Chemical Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6268 (United States); Cui, S. T. [Department of Chemical Engineering, University of Tennesee, Knoxville, Tennessee 37996-2200 (United States) [Department of Chemical Engineering, University of Tennesee, Knoxville, Tennessee 37996-2200 (United States); Cochran, H. D. [Department of Chemical Engineering, University of Tennesee, Knoxville, Tennessee 37996-2200 (United States) [Department of Chemical Engineering, University of Tennesee, Knoxville, Tennessee 37996-2200 (United States); Cummings, P. T. [Department of Chemical Engineering, University of Tennesee, Knoxville, Tennessee 37996-2200 (United States) [Department of Chemical Engineering, University of Tennesee, Knoxville, Tennessee 37996-2200 (United States); Chemical Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6268 (United States); Department of Chemistry and Department of Computer Science, University of Tennessee, Knoxville, Tennessee 37996-2200 (United States)

1999-12-01T23:59:59.000Z

266

Inverse melting in a system with positive heats of formation  

SciTech Connect (OSTI)

Supersaturated body-centered-cubic Fe-W solid solutions with positive heats of formation were prepared by cosputtering and mechanical alloying over a wide concentration range. Upon annealing, these solid solutions were observed to undergo amorphization in the range of 20{endash}37 at.{percent} W. For Fe{sub 70}W{sub 30} and Fe{sub 67}W{sub 33} the transformation was polymorphous, indicating an inverse melting behavior. A thermodynamic analysis of the Fe-W system, which was carried out using the calculation-of-phase-diagrams method, supported that inverse melting is energetically possible in the Fe-W system. The results demonstrate that inverse melting can also occur in systems with positive heats of amorphous phase formation. {copyright} {ital 1997} {ital The American Physical Society}

Bai, H.Y.; Michaelsen, C.; Bormann, R. [Institute for Materials Research, GKSS-Research Center, Max-Planck-Strasse, D-21502 Geesthacht (Germany)] [Institute for Materials Research, GKSS-Research Center, Max-Planck-Strasse, D-21502 Geesthacht (Germany)

1997-11-01T23:59:59.000Z

267

The effect of pressure upon the melting transition of polyethylene  

E-Print Network [OSTI]

THE EFFECT OF PRESSURE UPON THE MELTING TRANSITION OF POLYETHYLENE o m vS n Z 8 i c6 C 0 A Thesis By George Joseph Nros Approved as to style and content by: C a rman o Comm ttee (Head of Department) August 1961 ACKNOWLEDGEMENT... of the melting transition temperature of polyethylene was found to be linear for samples which have been annealed. This dependence was found to conform to the Clausius-Clapeyron equation and this equation was used to obtain values for the change in specific...

Mroz, George Joseph

1961-01-01T23:59:59.000Z

268

Decontamination and decarburization of stainless and carbon steel by melt refining  

SciTech Connect (OSTI)

With many nuclear reactors and facilities being decommissioned in the next ten to twenty years the concern for handling and storing Radioactive Scrap Metal (RSM) is growing. Upon direction of the DOE Office of Environmental Restoration and Waste Management, Lockheed Idaho Technology Company (LITCO) is developing technologies for the conditioning of spent fuels and high-level wastes for interim storage and repository acceptance, including the recycling of Radioactive Scrap Metals (RSM) for beneficial reuse with the DOE complex. In February 1993, Montana Tech of the University of Montana was contracted to develop and demonstrate technologies for the decontamination of stainless steel RSM. The general objectives of the Montana Tech research program included conducting a literature survey, performing laboratory scale melt refining experiments to optimize decontaminating slag compositions, performing an analysis of preferred melting techniques, coordinating pilot scale and commercial scale demonstrations, and producing sufficient quantities of surrogate-containing material for all of the laboratory, pilot and commercial scale test programs. Later on, the program was expanded to include decontamination of carbon steel RSM. Each research program has been completed, and results are presented in this report.

Mizia, R.E.; Worcester, S.A.; Twidwell, L.G.; Webber, D.; Paolini, D.J.; Weldon, T.A.

1996-09-05T23:59:59.000Z

269

Methods of vitrifying waste with low melting high lithia glass compositions  

DOE Patents [OSTI]

The invention relates to methods of vitrifying waste and for lowering the melting point of glass forming systems by including lithia formers in the glass forming composition in significant amounts, typically from about 0.16 wt % to about 11 wt %, based on the total glass forming oxides. The lithia is typically included as a replacement for alkali oxide glass formers that would normally be present in a particular glass forming system. Replacement can occur on a mole percent or weight percent basis, and typically results in a composition wherein lithia forms about 10 wt % to about 100 wt % of the alkali oxide glass formers present in the composition. The present invention also relates to the high lithia glass compositions formed by these methods. The invention is useful for stabilization of numerous types of waste materials, including aqueous waste streams, sludge solids, mixtures of aqueous supernate and sludge solids, combinations of spent filter aids from waste water treatment and waste sludges, supernate alone, incinerator ash, incinerator offgas blowdown, or combinations thereof, geological mine tailings and sludges, asbestos, inorganic filter media, cement waste forms in need of remediation, spent or partially spent ion exchange resins or zeolites, contaminated soils, lead paint, etc. The decrease in melting point achieved by the present invention desirably prevents volatilization of hazardous or radioactive species during vitrification.

Jantzen, Carol M. (Aiken, SC); Pickett, John B. (Aiken, SC); Cicero-Herman, Connie A. (Aiken, SC); Marra, James C. (Aiken, SC)

2001-01-01T23:59:59.000Z

270

Phase transformations of nano-sized cubic boron nitride to white graphene and white graphite  

SciTech Connect (OSTI)

We report quantum-mechanical investigations that predict the formation of white graphene and nano-sized white graphite from the first-order phase transformations of nano-sized boron nitride thin-films. The phase transformations from the nano-sized diamond-like structure, when the thickness d?>?1.4?nm, to the energetically more stable nano-sized white graphite involve low activation energies of less than 1.0?eV. On the other hand, the diamond-like structure transforms spontaneously to white graphite when d???1.4?nm. In particular, the two-dimensional structure with single-layer boron nitride, the so-called white graphene, could be formed as a result of such transformation.

Dang, Hongli; Liu, Yingdi; Xue, Wenhua; Anderson, Ryan S.; Sewell, Cody R. [Department of Physics and Engineering Physics, The University of Tulsa, Tulsa, Oklahoma 74104 (United States); Xue, Sha; Crunkleton, Daniel W. [Department of Chemical Engineering, The University of Tulsa, Tulsa, Oklahoma 74104 (United States); Institute of Alternate Energy, The University of Tulsa, Tulsa, Oklahoma 74104 (United States); Shen, Yaogen [Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Kowloon (Hong Kong); Wang, Sanwu, E-mail: sanwu-wang@utulsa.edu [Department of Physics and Engineering Physics, The University of Tulsa, Tulsa, Oklahoma 74104 (United States); Institute of Alternate Energy, The University of Tulsa, Tulsa, Oklahoma 74104 (United States)

2014-03-03T23:59:59.000Z

271

Modeling of interface cracking in copper–graphite composites by MD and CFE method  

Science Journals Connector (OSTI)

Abstract Molecular dynamics (MD) method was used to study mechanical properties of copper–graphite composite interface. Mode I fracture of the interface of copper–graphite composite was modeled by considering fixed and free boundary conditions, which means slipping constraint conditions for atomic layers in the composite. The stress near crack tip and the energy changes of the system are obtained. Then a cohesive traction–separation law of copper–graphite interface can also be obtained by using the MD simulation. For the purpose of comparisons, a modeling of interfacial fracture of the composite by using a zero-thickness cohesive finite element (CFE) was carried out. It is found that there is a stress concentration but no singularity for the normal stress at the crack tip in interface obtained by using the present MD simulation and CFE method. While in the interface away from the crack tip, the obtained stress is consistent with the solution of classical interfacial fracture mechanics.

Shi-Jun Guo; Qing-Sheng Yang; X.Q. He; K.M. Liew

2014-01-01T23:59:59.000Z

272

USA/FRG umbrella agreement for cooperation in GCR [Gas Cooled Reactor] development: Fuel, fission products and graphite subprogram. Part 1, Management meeting report: Part 2, Revised subprogram plan, Revision 10  

SciTech Connect (OSTI)

This Subprogram Plan describes cooperative work in the areas of HTR fuel and graphite development and fission product studies that is being carried out under US/FRG/Swiss Implementing Agreement for cooperation in Gas Cooled Reactor development. Only bilateral US/FRG cooperation is included, since it is the only active work in this subprogram area at this time. The cooperation has been in progress since February 1977. A number of Project Work Statements have been developed in each of the major areas of the subprogram, and work on many of them is in progress. The following specific areas are included in the scope of this plan: fuel development; graphite development; fission product release; and fission product behavior outside the fuel elements.

NONE

1986-05-01T23:59:59.000Z

273

A one-group parametric sensitivity analysis for the graphite isotope ratio method and other related techniques using ORIGEN 2.2  

E-Print Network [OSTI]

Several methods have been developed previously for estimating cumulative energy production and plutonium production from graphite-moderated reactors. The Graphite Isotope Ratio Method (GIRM) is one well-known technique. This method is based...

Chesson, Kristin Elaine

2009-06-02T23:59:59.000Z

274

Diffusive motions in 2D phases of ethane adsorbed on graphite J. P. Coulomb and M. Bienfait  

E-Print Network [OSTI]

89 Diffusive motions in 2D phases of ethane adsorbed on graphite J. P. Coulomb and M. Bienfait and translational mobility of a simple rod-like molecule, i.e. ethane (C2H6) adsorbed on graphite (0001), has been is made of molecules standing up on the adsorbing surface. With increasing temperature, a rotational

Paris-Sud XI, Université de

275

Improved Lithium Ion Behavior Properties of TiO2@Graphitic-like Carbon Core@Shell Nanostructure  

E-Print Network [OSTI]

Improved Lithium Ion Behavior Properties of TiO2@Graphitic-like Carbon Core@Shell Nanostructure Min Intercalation Electrochemistry Capacitance Lithium Ion batteries A B S T R A C T We demonstrate TiO2@graphitic on the electrode surface and enhanced lithium ion intercalation, leading to lower charge transfer resistance

Cao, Guozhong

276

A New Method for Quantitative Marking of Deposited Lithium via Chemical Treatment on Graphite Anodes in Lithium-Ion Cells  

E-Print Network [OSTI]

A New Method for Quantitative Marking of Deposited Lithium via Chemical Treatment on Graphite Anodes in Lithium-Ion Cells Yvonne Krämer*[a] , Claudia Birkenmaier[b] , Julian Feinauer[a,c] , Andreas*[e] and Thomas Schleid[f] Abstract: A novel approach for the marking of deposited lithium on graphite anodes from

Schmidt, Volker

277

Bismuth Nanoparticle Decorating Graphite Felt as a High-Performance Electrode for an All-Vanadium Redox Flow Battery  

Science Journals Connector (OSTI)

Bismuth Nanoparticle Decorating Graphite Felt as a High-Performance Electrode for an All-Vanadium Redox Flow Battery ... Employing electrolytes containing Bi3+, bismuth nanoparticles are synchronously electrodeposited onto the surface of a graphite felt electrode during operation of an all-vanadium redox flow battery (VRFB). ... Energy storage; redox flow battery; electrode; catalyst; vanadium ...

Bin Li; Meng Gu; Zimin Nie; Yuyan Shao; Qingtao Luo; Xiaoliang Wei; Xiaolin Li; Jie Xiao; Chongmin Wang; Vincent Sprenkle; Wei Wang

2013-02-11T23:59:59.000Z

278

Simplified Electrochemical and Thermal Model of LiFePO4-Graphite Li-Ion Batteries for Fast Charge Applications  

E-Print Network [OSTI]

Simplified Electrochemical and Thermal Model of LiFePO4- Graphite Li-Ion Batteries for Fast Charge, a simplified electrochemical and thermal model of LiFePO4-graphite based Li-ion batteries is developed for battery management system (BMS) applications and comprehensive aging investigations. Based on a modified

Paris-Sud XI, Université de

279

Elasticity of single-crystalline graphite: Inelastic x-ray scattering study Alexey Bosak and Michael Krisch  

E-Print Network [OSTI]

. IXS overcomes the intrinsic difficulties of inelastic neutron scattering INS -- namely, sample sizeElasticity of single-crystalline graphite: Inelastic x-ray scattering study Alexey Bosak of the five independent elastic moduli of single-crystalline graphite, using inelastic x-ray scattering IXS

Nabben, Reinhard

280

Molecular models for the intercalation of hydrogen molecules into modified graphites  

SciTech Connect (OSTI)

Carbonized aerogels have been proposed as a medium for the storage of H{sub 2} gas. Quantum chemical calculations were performed on a series of substituted polyaromatic ring compounds. Parallel ``sandwiches`` of these compounds were used as a model of graphite. Hydrogen was introduced between the compounds as a model of H{sub 2} intercalated into graphite. It was found that it required work to insert the H{sub 2} into most of the compounds, except when the presence of the hydrogen allowed the compound to find a new configuration with a lower energy.

Calef, D.F. [Lawrence Livermore National Lab., CA (United States). Chemistry and Materials Science Directorate

1995-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "melting includes graphite" 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

Analysis of the effect of matrix degradation on fatigue behavior of a graphite/epoxy laminate  

E-Print Network [OSTI]

ANALYSIS OF THE EFFECT OF MATRIX DEGRADATION ON FATIGUE BEHAVIOR OF A GRAPHITE/EPOXY LAMINATE A Thesis by ROBERT THOMAS ARENBURG Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement... for the degree of MASTER OF SCIENCE May 1982 Major Subject: Civil Engineering ANALYSiS OF THE EFFECT OF MATRIX DEGRAOATION ON FATIGUE BEHAVIOR OF A GRAPHITE/EPOXY LAMINATE A Thesis by ROBERT THOMAS ARENBURG Approved as to style and content by: (Chairman...

Arenburg, Robert Thomas

2012-06-07T23:59:59.000Z

282

Hygrothermal effects in an anti-symmetric cross-ply graphite/epoxy material  

E-Print Network [OSTI]

HYGROTHERMAL EFFECTS IN AN ANTI-SYMMETRIC CROSS-PLY GRAPHITE/EPOXY MATERIAL A Thesis STEVEN PAUL JACKSON Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirement for the degree of MASTER OF SC...'IENCE May 1984 Major Subject: Aerospace Engineering HYGROTHERMAL ~S IN AN ANTI-SYMMETRIC CROSS-PLY GRAPHITE/EPOXY LAMINATE A Thesis STEVE? PAUL JACKSON Approved as to style and content by: (Y. eitsman, Charrman) (W. L. Bradley, M (W. E. Haisler...

Jackson, Steven Paul

2012-06-07T23:59:59.000Z

283

Near-field thermal radiation between hyperbolic metamaterials: Graphite and carbon nanotubes  

SciTech Connect (OSTI)

The near-field radiative heat transfer for two hyperbolic metamaterials, namely, graphite and vertically aligned carbon nanotubes (CNTs), is investigated. Graphite is a naturally existing uniaxial medium, while CNT arrays can be modeled as an effective anisotropic medium. Different hyperbolic modes can be separately supported by these materials in certain infrared regions, resulting in a strong enhancement in near-field heat transfer. It is predicted that the heat flux between two CNT arrays can exceed that between SiC plates at any vacuum gap distance and is about 10 times higher with a 10?nm gap.

Liu, X. L.; Zhang, R. Z.; Zhang, Z. M., E-mail: zhuomin.zhang@me.gatech.edu [G. W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States)

2013-11-18T23:59:59.000Z

284

Laser-processed three dimensional graphitic electrodes for diamond radiation detectors  

SciTech Connect (OSTI)

We have used an original approach for diamond detectors where three dimensional buried graphitic electrodes are processed in the bulk of a diamond substrate via laser-induced graphitization. Prototype made of polycrystalline chemical vapor deposition diamond was fabricated using a nanosecond UV laser. Its charge collection efficiency was evaluated using ?-particles emitted by a 241-Americium source. An improved charge collection efficiency was measured proving that laser micro-machining of diamond is a valid option for the future fabrication of three dimensional diamond detectors.

Caylar, Beno?-carett; Pomorski, Michal; Bergonzo, Philippe [CEA-LIST, Diamond Sensors Laboratory, Gif-sur-Yvette F-91191 (France)] [CEA-LIST, Diamond Sensors Laboratory, Gif-sur-Yvette F-91191 (France)

2013-07-22T23:59:59.000Z

285

The impact of hot-melt adhesives on the paper recycling process  

SciTech Connect (OSTI)

Hot melts and other adhesives can cause contamination problems in recycling paper and paper board. Some types of hot melts cause more problems than others in fouling mill equipment and affecting paper quality. Adhesive manufacturers are evaluating two categories of repulpable hot melts--dispersible or soluble hot melts and recoverable hot melts. This paper examines the paper recycling process to understand how hot melts cause problems. A simplified depiction of a paper recycling operation is shown. The steps in the process are described.

Hayes, P.J. (Nacan Products Ltd., Bampton, Ontario (Canada). Adhesive Division); Kauffman, T.F. (National Starch and Chemical Co., Bridgewater, NJ (United States))

1993-11-01T23:59:59.000Z

286

Potential for tunneling based on rock and soil melting. Abstracts  

SciTech Connect (OSTI)

The rock-melting drill was invented at Los Alamos Scientific Laboratory in 1960. Electrically heated, laboratory-scale drills were subsequently shown to penetrate igneous rocks at usefully high rates, with moderate power consumptions. The development of compact nuclear reactors and of heat pipes now makes possible the extension of this technology to much larger melting penetrators, potentially capable of producing holes up to several meters in diameter and several tens of kilometers long or deep. Development of a rapid, versatile, economical method of boring large, long shafts and tunnels offers solutions to many of man's most urgent ecological, scientific, raw-materials, and energy-supply problems. A melting method appears to be the most promising and flexible means of producing such holes. It is relatively insensitive to the composition, hardness, structure, and temperature of the rock, and offers the possibilities of producing self-supporting, glass-lined holes in almost any formation and (using a technique called lithofracturing) of eliminating the debris-removal problem by forcing molten rock into cracks created in the bore wall. Large rock-melting penetrators, called Electric Subterrenes or Nuclear Subterrenes according to the energy source used, are discussed in this report, together with problems anticipated in their development. It is concluded that this development is within the grasp of present technology.

Rowley, J.C.

1985-01-01T23:59:59.000Z

287

Empirical Relationships for Estimating Liquid Water Fraction of Melting Snowflakes  

Science Journals Connector (OSTI)

The liquid water fraction of individual snowflakes f is an important parameter when calculating the radar reflectivity of a melting layer. A ground-based observation of f at Nagaoka, Japan, was conducted by using dye-treated filter papers that ...

Ryohei Misumi; Hiroki Motoyoshi; Satoru Yamaguchi; Sento Nakai; Masaaki Ishizaka; Yasushi Fujiyoshi

2014-10-01T23:59:59.000Z

288

Seasonal glacier melt contribution to streamflow Neil Schaner  

E-Print Network [OSTI]

extent and water storage globally have lead to concerns about the implications for water supplies to seasonal streamflow by computing the energy balance of glaciers globally. Melt water quantities%) of streamflow, mostly in the High Asia region. One sixth of the world's population, and one quarter of its gross

Washington at Seattle, University of

289

Solubility of water in lime-alumina-silica melts  

Science Journals Connector (OSTI)

The water solubility in fused silicates of the CaO-SiO2 and CaO-SiO2-Al2O3...systems has been measured using a vacuum fusion technique. The melts were equilibrated with nitrogen as “carrier gas” containing an acc...

P. L. Sachdev; A. Majdi?; H. Schenck

1972-06-01T23:59:59.000Z

290

THERMODYNAMIC AND TRANSPORT PROPERTIES OF SILICATE MELTS AND MAGMA  

E-Print Network [OSTI]

PROPERTIES5 Density and Equation of State6 Enthalpy, Entropy and Heat Capacity7 VI. MAGMA TRANSPORT-1- THERMODYNAMIC AND TRANSPORT PROPERTIES OF SILICATE MELTS AND MAGMA Charles E. Lesher PROPERTIES8 Magma Rheology9 Thermal Conductivity: Radiative and Phonon10 Diffusion: Self, Tracer and Chemical

Spera, Frank J.

291

An analysis of variations in isentropic melt productivity  

Science Journals Connector (OSTI)

...Solid solutions at atmospheric pressure in the system CaO MgOSiO2 with special reference to the instabilities of diopside, akermanite, and monticellite. Prog. Exp. Pet. pp. 8996. London: NERC. Cawthorn, R. G. 1975 Degrees of melting in mantle diapirs...

1997-01-01T23:59:59.000Z

292

Decontamination of metals by melt refining/slagging. An annotated bibliography: Update on stainless steel and steel  

SciTech Connect (OSTI)

The following presentation is an update to a previous annotation, i.e., WINCO-1138. The literature search and annotated review covers all metals used in the nuclear industries but the emphasis of this update is directed toward work performed on mild steels. As the number of nuclear installations undergoing decontamination and decommissioning (D&D) increases, current radioactive waste storage space is consumed and establishment of new waste storage areas becomes increasingly difficult, the problem of handling and storing radioactive scrap metal (RSM) gains increasing importance in the DOE Environmental Restoration and Waste Management Program. To alleviate present and future waste problems, Lockheed Idaho Technologies Co (LITCO) is managing a program for the recycling of RSM for beneficial use within the DOE complex. As part of that effort, Montana Tech has been awarded a contract to help optimize melting and refining technology for the recycling of stainless steel RSM. The scope of the Montana Tech program includes a literature survey, a decontaminating slag design study, small wide melting studies to determine optimum slag compositions for removal of radioactive contaminant surrogates, analysis of preferred melting techniques, and coordination of large scale melting demonstrations (100--2,000 lbs) to be conducted at selected facilities. The program will support recycling and decontaminating stainless steel RSM for use in waste canisters for Idaho Waste Immobilization Facility densified high level waste and Pit 9/RWMC boxes. This report is the result of the literature search conducted to establish a basis for experimental melt/slag program development. The program plan will be jointly developed by Montana Tech and LITCO.

Worchester, S.A.; Twidwell, L.G.; Paolini, D.J.; Weldon, T.A. [Montana Tech of the Univ., of Montana (United States); Mizia, R.E. [Lockheed Idaho Technologies Co., Idaho Falls, ID (United States)

1995-01-01T23:59:59.000Z

293

Atomic-Level Study of Melting Behavior of GaN Nanotubes. | EMSL  

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

Melting Behavior of GaN Nanotubes. Atomic-Level Study of Melting Behavior of GaN Nanotubes. Abstract: Molecular dynamics simulations with a Stillinger-Weber potential have been...

294

Investigation into the Morphology and Mechanical Properties of Melt-Drawn Filaments from  

E-Print Network [OSTI]

-density polyethylene (HDPE) were melt-processed in a single-screw extruder fitted with a fine screen mesh and capillary in extruder output rate in this region, an indicator of the melt interaction of the two phases as co

295

A melting model for variably depleted and enriched lherzolite in the plagioclase and spinel stability fields  

E-Print Network [OSTI]

Here we develop a lherzolite melting model and explore the effects of variations in mantle composition, pressure, temperature, and H[subscript 2]O content on melt composition. New experiments and a compilation of experimental ...

Till, Christy B.

296

Controls on spatial and temporal variability in Northern Hemisphere terrestrial snow melt timing, 1979-2012  

Science Journals Connector (OSTI)

Spring snow melt onset has occurred earlier across much of Northern Hemisphere lands in the last four decades. Understanding the mechanisms driving spring melt has remained a challenge, particularly in its spatial and temporal variability. Here, ...

J. R. Mioduszewski; A. K. Rennermalm; D. A. Robinson; L. Wang

297

What Controls the Melting Properties of DNA-Linked Gold Nanoparticle Assemblies?  

E-Print Network [OSTI]

What Controls the Melting Properties of DNA-Linked Gold Nanoparticle Assemblies? Rongchao Jin the relative importance of nanoparticle, oligonucleotide, and environmental variables that contribute to the observed sharp melting transitions associated with DNA-linked nanoparticle structures. These variables

298

A Comparison of Melt Processes to Prepare YBaCuO with High J c  

Science Journals Connector (OSTI)

There are several melt processes which promise high J c ...in bulk YBaCuO. A comparison of various melt processes such as MTG and MPMG was performed in this stud...

M. Murakami; A. Kondoh; H. Fujimoto; K. Takamuku…

1992-01-01T23:59:59.000Z

299

ITP Metal Casting: Advanced Melting Technologies: Energy Saving Concepts and Opportunities for the Metal Casting Industry  

Broader source: Energy.gov [DOE]

The study examines current and emerging melting technologies and discusses their technical barriers to scale-up issues and research needed to advance these technologies, improving melting efficiency, lowering metal transfer heat loss, and reducing scrap.

300

Laser-excited atomic fluorescence spectrometry in a graphite furnace with an  

E-Print Network [OSTI]

Laser-excited atomic fluorescence spectrometry in a graphite furnace with an optical parametric oscillator laser for sequential multi-element determination of cadmium, cobalt, lead, manganese and thallium, for the ® rst time, that solid-state lasers required for analysis (ml or mg) and the technique has direct based

Michel, Robert G.

Note: This page contains sample records for the topic "melting includes graphite" 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.


301

Commensurate-incommensurate transition of Kr-Xe mixtures on graphite  

Science Journals Connector (OSTI)

We report high-resolution x-ray scattering measurements of the commensurate-incommensurate transition of Kr on graphite which has been preplated with 0.1 monolayer of Xe. The Xe raises transition pressure, and produces a 31% range of pressures over which composite lineshapes are observed. These results are discussed in terms of a solubility gap between commensurate and incommensurate phases.

Peter W. Stephens; Alan I. Goldman; Paul A. Heiney; Peter A. Bancel

1986-01-01T23:59:59.000Z

302

Electrode material comprising graphene-composite materials in a graphite network  

DOE Patents [OSTI]

A durable electrode material suitable for use in Li ion batteries is provided. The material is comprised of a continuous network of graphite regions integrated with, and in good electrical contact with a composite comprising graphene sheets and an electrically active material, such as silicon, wherein the electrically active material is dispersed between, and supported by, the graphene sheets.

Kung, Harold H.; Lee, Jung K.

2014-07-15T23:59:59.000Z

303

Graphite and Hexagonal Boron-Nitride have the Same Interlayer Distance. Why?  

E-Print Network [OSTI]

serves as a building block for few-layered graphene and graphite as well as for single- and multi prominent members of the family of layered materials possessing a hexagonal lattice structure. While-8 In recent years, the most prominent member of the family of layered materials has been graphene,9-12 which

Hod, Oded

304

Tetrafluoromethane monolayer physisorbed on graphite : its orientational walls and its complex phase diagram  

E-Print Network [OSTI]

par diffraction de neutrons de la structure de la monocouche de CF4 physisorbée sur diffé- rents ce système complexe. Abstract. 2014 Neutron diffraction results for a monolayer of CF4 physisorbed studies of a physi- sorbed monolayer on graphite. It was thought that CF4, a very nearly spherical

Paris-Sud XI, Université de

305

Adsorption and catalyzed reactions of CO and CO/sub 2/ on graphite surfaces  

SciTech Connect (OSTI)

This work is a study of catalytic reactions of graphite with CO and CO/sub 2/. The experimental probes that are brought to bear on this problem are Auger electron spectroscopy (AES) for elemental analysis of the surface, temperature programmed desorption (TPD) to examine thermal decomposition of adsorbate species and, finally, x-ray photoelectron specroscopy (XPS) in order to identify surface entities.

Tysoe, W.T.; Carrazza, J.; Somorjai, G.A.

1984-01-01T23:59:59.000Z

306

Relative and kinetic properties of carbon monoxide and carbon dioxide on a graphite surface  

SciTech Connect (OSTI)

Temperature-programmed desorption (TPD) results after chemisorption of carbon monoxide (CO) and carbon dioxide (CO/sub 2/) on polycrystalline graphite are presented. CO adsorbs onto graphite with a very low sticking coefficient. After CO chemisorption CO (mass 28 amu) desorbs in two temperature regions, between 400 and 700 K and between 1000 and 1300 K, and CO/sub 2/ (mass 44 amu) desorbs below 950 K. The intensity of the CO/sub 2/ signal is less than 1 order of magnitude lower than the CO intensity. After CO/sub 2/ adsorption the major desorption product is CO at high temperatures (1000 < T (K) < 1300), whereas a small amount of CO/sub 2/ desorbs around 450 K. The adsorption of C/sup 16/O/sub 2/ and C/sup 18/O/sub 2/ mixture leads to a nearly total oxygen scrambling of the CO/sub 2/ desorbed. A mechanism for CO and CO/sub 2/ interconversion on the graphite surface is presented in terms of surface oxide species, mainly lactones and semiquinones, and their relative stability. Assignments of the TPD features are proposed accordingly. Reaction studies on the CO/sub 2/ gasification of clean graphite and the CO disproportionation (Boudouard reaction) have been performed. A good agreement is found between the activation energies obtained and the desorption energies calculated from the analysis of the TPD results.

Marchon, B.; Tysoe, W.T.; Carrazza, J.; Heinemann, H.; Somorjai, G.A.

1988-10-06T23:59:59.000Z

307

Single Sheet Functionalized Graphene by Oxidation and Thermal Expansion of Graphite  

E-Print Network [OSTI]

,X,O Margarita Herrera-Alonso, David L. Milius, Roberto Car,,§ Robert K. Prud'homme, and Ilhan A. Aksay, the functionalized and defective graphene sheets do not collapse back to graphite oxide but are highly agglomerated and Roberto Car (Princeton University) showed that the stress-strain behaviors of graphene sheets and SWCNTs

Aksay, Ilhan A.

308

Stable aqueous suspension and self-assembly of graphite nanoplatelets coated with various polyelectrolytes  

Science Journals Connector (OSTI)

Exfoliated graphite nanoplatelets (xGnPs) with an average thickness of 1-10 nm present an inexpensive alternative to carbon nanotubes in many applications. In this paper, stable aqueous suspension of xGnP was achieved by noncovalent functionalization ...

Jue Lu; Inhwan Do; Hiroyuki Fukushima; Ilsoon Lee; Lawrence T. Drzal

2010-01-01T23:59:59.000Z

309

Dynamic Monte-Carlo modeling of hydrogen isotope reactivediffusive transport in porous graphite  

E-Print Network [OSTI]

by voids which are typically a fraction of a microm- eter. The granules consist of graphitic micro-crystal- lites of size 10­100 nm separated by micro-voids which are typically 1 nm (Fig. 1) [1­4]. These sub chemical reactions to form hydrocarbons or recombine to form hydro- gen molecules which can then diffuse

Nordlund, Kai

310

An electrochemically reduced graphite-cobalt compound : synthesis and magnetic study  

E-Print Network [OSTI]

direct intercalation of transition metals into graphite. One of the reasons could be the very high to metal- carbides formation than G.I.C.'s. Only indirect pre- paration methods have been described by many authors mostly consisting on a chemical [2-7] or electrochemical [8-10] reduction of the transition metal

Paris-Sud XI, Université de

311

On the Effect of Porous Layers on Melting Heat Transfer in an Enclosure  

E-Print Network [OSTI]

On the Effect of Porous Layers on Melting Heat Transfer in an Enclosure E. A. Ellinger* and C. To enhance heat transfer, the porous layers are located in regions where the melting rates for a pure the porous layer and the pure fluid layer cause strong variations in heat transfer, melt convection

Beckermann, Christoph

312

GEOCHEMISTRY AND 40 AR GEOCHRONOLOGY OF IMPACT-MELT CLASTS IN LUNAR  

E-Print Network [OSTI]

-melt clasts in lunar meteorites [1, 2]. The dissimilarity of DaG262 and Calcalong Creek impact-melt clasts clasts, melt veins and metal grains. Calcalong Creek [4] is a polymict breccia containing sub-mm clasts of both highlands and mare affinity welded by a glassy, vesicular matrix. It is unusual among lunar

Cohen, Barbara Anne

313

Examining the mechanics of granulation with a hot melt binder in a twin-screw extruder  

E-Print Network [OSTI]

Examining the mechanics of granulation with a hot melt binder in a twin-screw extruder B. Mu, M processing Melt agglomeration Twin screw extruder a b s t r a c t Hot melt granulation involves particle-rotating intermeshing twin screw extruder for operating temperatures between 80 1C and 120 1C. Three different screw

Thompson, Michael

314

A model of the threedimensional evolution of Arctic melt ponds on firstyear and multiyear sea ice  

E-Print Network [OSTI]

ice. In the summer the upper layers of sea ice and snow melts producing meltwater that accumulatesA model of the threedimensional evolution of Arctic melt ponds on firstyear and multiyear sea ice F in Arctic melt ponds on the surface of sea ice. An accurate estimate of the fraction of the sea ice surface

Feltham, Daniel

315

Molecular dynamics simulations of the melting curve of NiAl alloy under pressure  

SciTech Connect (OSTI)

The melting curve of B2-NiAl alloy under pressure has been investigated using molecular dynamics technique and the embedded atom method (EAM) potential. The melting temperatures were determined with two approaches, the one-phase and the two-phase methods. The first one simulates a homogeneous melting, while the second one involves a heterogeneous melting of materials. Both approaches reduce the superheating effectively and their results are close to each other at the applied pressures. By fitting the well-known Simon equation to our melting data, we yielded the melting curves for NiAl: 1783(1 + P/9.801){sup 0.298} (one-phase approach), 1850(1 + P/12.806){sup 0.357} (two-phase approach). The good agreement of the resulting equation of states and the zero-pressure melting point (calc., 1850 ± 25 K, exp., 1911 K) with experiment proved the correctness of these results. These melting data complemented the absence of experimental high-pressure melting of NiAl. To check the transferability of this EAM potential, we have also predicted the melting curves of pure nickel and pure aluminum. Results show the calculated melting point of Nickel agrees well with experiment at zero pressure, while the melting point of aluminum is slightly higher than experiment.

Zhang, Wenjin; Peng, Yufeng [College of Physics and electronic Engineering, Henan Normal University, Xinxiang, 453007 (China)] [College of Physics and electronic Engineering, Henan Normal University, Xinxiang, 453007 (China); Liu, Zhongli, E-mail: zhongliliu@yeah.net [College of Physics and Electric Information, Luoyang Normal University, Luoyang, 471002 (China)] [College of Physics and Electric Information, Luoyang Normal University, Luoyang, 471002 (China)

2014-05-15T23:59:59.000Z

316

Complex Isothermal Crystallization and Melting Behavior of Nylon 6 Nanoclay Hybrids  

Science Journals Connector (OSTI)

Complex Isothermal Crystallization and Melting Behavior of Nylon 6 Nanoclay Hybrids ... The complex crystallization and melting behavior of neat Nylon-6 and two Nylon-6-nanoclay hybrids with different montmorillonite concentration was studied using several experimental techniques. ... The results, depending on the crystallization temperature, indicated two sequences of melting for neat Nylon-6 and four for the nanoclay hybrids. ...

A. Zapata-Espinosa; F. J. Medellín-Rodríguez; N. Stribeck; A. Almendarez-Camarillo; S. Vega-Díaz; B. S. Hsiao; B. Chu

2005-04-16T23:59:59.000Z

317

Accepted for Publication in J. Rheology (May/June 2005 Issue) March 1, 2005 Measuring the Transient Extensional Rheology of Polyethylene Melts  

E-Print Network [OSTI]

Extensional Rheology of Polyethylene Melts Using the SER Universal Testing Platform Martin Sentmanat Senkhar stress growth in a number of different molten polyethylene samples including a linear low density polyethylene (Dow Affinity PL 1880), a low density polyethylene (Lupolen 1840H) and an ultrahigh molecular

318

The probability of Mark-I containment failure by melt-attack of the liner  

SciTech Connect (OSTI)

This report is a followup to the work presented in NUREG/CR-5423 addressing early failure of a BWR Mark I containment by melt attack of the liner, and it constitutes a part of the implementation of the Risk-Oriented Accident Analysis Methodology (ROAAM) employed therein. In particular, it expands the quantification to include four independent evaluations carried out at Rensselaer Polytechnic Institute, Argonne National Laboratories, Sandia National Laboratories and ANATECH, Inc. on the various portions of the phenomenology involved. These independent evaluations are included here as Parts II through V. The results, and their integration in Part I, demonstrate the substantial synergism and convergence necessary to recognize that the issue has been resolved.

Theofanous, T.G.; Yan, H. [California Univ., Santa Barbara, CA (United States). Dept. of Chemical and Nuclear Engineering; Podowski, M.Z. [Rensselaer Polytechnic Inst., Troy, NY (United States). Dept. of Nuclear Engineering and Engineering Physics] [and others

1993-11-01T23:59:59.000Z

319

Laser induced melting and crystallization of boron doped amorphous silicon  

SciTech Connect (OSTI)

Transient reflectivity experiments have been performed to measure the dynamics of laser-induced melting of amorphous silicon (a-Si) and the crystallization to {micro}c-Si of films with different thicknesses on Corning 7059 glass. The laser-induced melting takes place with a velocity of 13 to 24 m/s, while the solidification is about a factor 10 slower. The crystallization starts at the Si/glass interface and at the surface. In the center of the films Si remains liquid for an extended period of time. The crystallization dynamics point towards an heterogeneous morphology of laser-crystallized Si, where the surface and the interface layers are composed of small grains and the bulk of larger grains.

Nebel, C.E.; Schoeniger, S.; Dahlheimer, B.; Stutzmann, M.

1997-07-01T23:59:59.000Z

320

Polymer crystal-melt interfaces and nucleation in polyethylene  

E-Print Network [OSTI]

Kinetic barriers cause polymers to crystallize incompletely, into nanoscale lamellae interleaved with amorphous regions. As a result, crystalline polymers are full of crystal-melt interfaces, which dominate their physical properties. The longstanding theoretical challenge to understand these interfaces has new relevance, because of accumulating evidence that polymer crystals often nucleate via a metastable, partially ordered "rotator" phase. To test this idea requires a theory of the bulk and interfacial free energies of the critical nucleus. We present a new approach to the crystal-melt interface, which represents the amorphous region as a grafted brush of loops in a self-consistent pressure field. We combine this theory with estimates of bulk free energy differences, to calculate nucleation barriers and rates via rotator versus crystal nuclei for polyethylene. We find rotator-phase nucleation is indeed favored throughout the temperature range where nucleation is observed. Our methods can be extended to other polymers.

Scott T. Milner

2010-09-22T23:59:59.000Z

Note: This page contains sample records for the topic "melting includes graphite" 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

Experimental investigation of the melting transition of the plasma crystal  

Science Journals Connector (OSTI)

Measurements of the melting transition of a Coulomb crystal consisting of dust particles immersed in an rf parallel plate discharge in helium were performed. The dust crystal is shown to be solid at higher gas pressure (120 Pa) and low discharge power (10–20 W). Reducing the gas pressure or increasing the discharge power leads to fluid states of the dust ensemble. Even gaslike states are observed at low pressures of about 40 Pa. The transition is attributed to an increasing effective particle temperature. The phase transition is compared with one-component-plasma and Yukawa models, and with basic predictions of theories for two-dimensional melting. © 1996 The American Physical Society.

A. Melzer; A. Homann; A. Piel

1996-03-01T23:59:59.000Z

322

Technical Evaluation Summary of the In Situ Vitrification Melt Expulsion at the Oak Ridge National Laboratory on April 21, 1996, Oak Ridge, Tennessee  

SciTech Connect (OSTI)

This Technical Evaluation Summary of the In Situ Vitrification Melt Expulsion at the Oak Ridge National Laboratory on April 21, 1996, was prepared at the request of the Department of Energy as a supporting reference document for the Final Unusual Occurrence Report to fully explore the probable causes that lead to the subject incident. This document provides the Environmental Restoration Program with the technical information on the performance of the in situ vitrification treatability study operations at ORNL pit 1 up to and including the time of the melt expulsion incident. This document also attempts to diagnose the causes of the melt expulsion event the consequent damages to equipment the radiological impacts of the event, and the equipment design modifications and procedural changes necessary for future safe ISV operations.

NONE

1996-11-01T23:59:59.000Z

323

Removing a sheet from the surface of a melt using gas jets  

DOE Patents [OSTI]

In one embodiment, a sheet production apparatus comprises a vessel configured to hold a melt of a material. A cooling plate is disposed proximate the melt and is configured to form a sheet of the material on the melt. A first gas jet is configured to direct a gas toward an edge of the vessel. A sheet of a material is translated horizontally on a surface of the melt and the sheet is removed from the melt. The first gas jet may be directed at the meniscus and may stabilize this meniscus or increase local pressure within the meniscus.

Kellerman, Peter L; Thronson, Gregory D; Sun, Dawei

2014-04-01T23:59:59.000Z

324

Dislocation-mediated melting of one-dimensional Rydberg crystals  

SciTech Connect (OSTI)

We consider cold Rydberg atoms in a one-dimensional optical lattice in the Mott regime with a single atom per site at zero temperature. An external laser drive with Rabi frequency {Omega} and laser detuning {Delta} creates Rydberg excitations whose dynamics is governed by an effective spin-chain model with (quasi) long-range interactions. This system possesses intrinsically a large degree of frustration resulting in a ground-state phase diagram in the ({Delta},{Omega}) plane with a rich topology. As a function of {Delta}, the Rydberg blockade effect gives rise to a series of crystalline phases commensurate with the optical lattice that form a so-called devil's staircase. The Rabi frequency {Omega}, on the other hand, creates quantum fluctuations that eventually lead to a quantum melting of the crystalline states. Upon increasing {Omega}, we find that generically a commensurate-incommensurate transition to a floating Rydberg crystal that supports gapless phonon excitations occurs first. For even larger {Omega}, dislocations within the floating Rydberg crystal start to proliferate and a second, Kosterlitz-Thouless-Nelson-Halperin-Young dislocation-mediated melting transition finally destroys the crystalline arrangement of Rydberg excitations. This latter melting transition is generic for one-dimensional Rydberg crystals and persists even in the absence of an optical lattice. The floating phase and the concomitant transitions can, in principle, be detected by Bragg scattering of light.

Sela, Eran; Garst, Markus [Institut fuer Theoretische Physik, Universitaet zu Koeln, Zuelpicher Str. 77, DE-50937 Koeln (Germany); Punk, Matthias [Physik Department, Technische Universitaet Muenchen, James-Franck-Strasse, DE-85748 Garching (Germany); Department of Physics, Harvard University, Cambridge, Massachusetts 02138 (United States)

2011-08-15T23:59:59.000Z

325

Crystallization and melting of a system of charges in a liquid helium cluster  

SciTech Connect (OSTI)

A system of like (positive or negative) charges forming 'snowballs' or 'bubbles' in a three-dimensional liquid helium cluster is investigated. The charges are confined inside the cluster by an 'image potential' produced by the polarization of liquid helium. The stability of a multiply charged helium cluster is considered. Computer simulations are used to investigate the crystallization and melting of the system of charges depending on the dimensionless parameter T* = k{sub B}T{epsilon}R/e{sup 2}, where k{sub B} is the Boltzmann constant, T is the temperature, {epsilon} is the dielectric constant of liquid helium, R is the cluster radius, and e is a unit charge. Various characteristics, including symmetry groups and moments, have been found for equilibrium configurations of charges in a cluster with N = 1-100 charges. At small N {approx} 10, Thomson's model of successive filling of 'belts' of charges can be used to describe the structure of equilibrium configurations of charges. At large N, the description of the structure formed by charges using the idea of a quasi-two-dimensional 'closed triangular lattice' with topological defects is more adequate. Formally, this description is valid starting from N = 4. The melting of a 'lattice' of charges is described. A number of our conclusions can be generalized to clusters of other noble gases.

Livshits, A. M., E-mail: livshits@isan.troitsk.ru; Lozovik, Yu. E. [Russian Academy of Sciences, Institute of Spectroscopy (Russian Federation)

2007-10-15T23:59:59.000Z

326

MELT WIRE SENSORS AVAILABLE TO DETERMINE PEAK TEMPERATURES IN ATR IRRADIATION TESTING  

SciTech Connect (OSTI)

In April 2007, the Department of Energy (DOE) designated the Advanced Test Reactor (ATR) a National Scientific User Facility (NSUF) to advance US leadership in nuclear science and technology. By attracting new users from universities, laboratories, and industry, the ATR will support basic and applied nuclear research and development and help address the nation's energy security needs. In support of this new program, the Idaho National Laboratory (INL) has developed in-house capabilities to fabricate, test, and qualify new and enhanced temperature sensors for irradiation testing. Although most efforts emphasize sensors capable of providing real-time data, selected tasks have been completed to enhance sensors provided in irradiation locations where instrumentation leads cannot be included, such as drop-in capsule and Hydraulic Shuttle Irradiation System (HSIS) or 'rabbit' locations. To meet the need for these locations, the INL has developed melt wire temperature sensors for use in ATR irradiation testing. Differential scanning calorimetry and environmental testing of prototypical sensors was used to develop a library of 28 melt wire materials, capable of detecting peak irradiation temperatures ranging from 85 to 1500°C. This paper will discuss the development work and present test results.

K. L. Davis; D. Knudson; J. Daw; J. Palmer; J. L. Rempe

2012-07-01T23:59:59.000Z

327

The Treatment of Mixed Waste with GeoMelt In-Container Vitrification  

SciTech Connect (OSTI)

AMEC's GeoMelt{sup R} In-Container Vitrification (ICV){sup TM} has been used to treat diverse types of mixed low-level radioactive waste. ICV is effective in the treatment of mixed wastes containing polychlorinated biphenyls (PCBs) and other semi-volatile organic compounds, volatile organic compounds (VOCs) and heavy metals. The GeoMelt vitrification process destroys organic compounds and immobilizes metals and radionuclides in an extremely durable glass waste form. The process is flexible allowing for treatment of aqueous, oily, and solid mixed waste, including contaminated soil. In 2004, ICV was used to treat mixed radioactive waste sludge containing PCBs generated from a commercial cleanup project regulated by the Toxic Substances Control Act (TSCA), and to treat contaminated soil from Rocky Flats Environmental Technology Site. The Rocky Flats soil contained cadmium, PCBs, and depleted uranium. In 2005, AMEC completed a treatability demonstration of the ICV technology on Mock High Explosive from Sandia National Laboratories. This paper summarizes results from these mixed waste treatment projects. (authors)

Finucane, K.G.; Campbell, B.E. [AMEC Earth and Environmental, Inc., 1135 Jadwin Avenue, Richland, Washington 99352 (United States)

2006-07-01T23:59:59.000Z

328

Synthesis of Graphene Layers from Metal-Carbon Melts: Nucleation and Growth Kinetics  

E-Print Network [OSTI]

both stable graphite and metal stable carbide formation. ForCarbide Eutectic in Nickel-Carbon Alloys The Physics of Metals andcarbide transition As it was explained in section 1.2 in some of metal-

Amini, Shaahin

2012-01-01T23:59:59.000Z

329

Net Taxable Gasoline Gallons (Including Aviation Gasoline)  

E-Print Network [OSTI]

Net Taxable Gasoline Gallons (Including Aviation Gasoline) Period 2000 2001 (2) 2002 2003 2004 "gross" to "net" , was deemed impractical. (5) This report replaces the Gross Taxable Gasoline Gallons (Including Aviation Gasoline) report which will not be produced after December 2002. (6) The November 2007

330

A mixed-solvent strategy for facile and green preparation of graphene by liquid-phase exfoliation of graphite  

Science Journals Connector (OSTI)

A versatile and scalable mixed-solvent strategy, by which two mediocre solvents could be combined into good solvents for exfoliating graphite, is demonstrated for facile and green preparation of graphene by liqui...

Min Yi; Zhigang Shen; Shulin Ma; Xiaojing Zhang

2012-07-01T23:59:59.000Z

331

Nitrogen-Doped Carbon Nanotube/Graphite Felts as Advanced Electrode Materials for Vanadium Redox Flow Batteries  

Science Journals Connector (OSTI)

vanadium redox flow battery; nitrogen doping; carbon nanotubes; graphite felt ... Nanorod Niobium Oxide as Powerful Catalysts for an All Vanadium Redox Flow Battery ... Nanorod Niobium Oxide as Powerful Catalysts for an All Vanadium Redox Flow Battery ...

Shuangyin Wang; Xinsheng Zhao; Thomas Cochell; Arumugam Manthiram

2012-07-27T23:59:59.000Z

332

Improved thermal stability of graphite electrodes in lithium-ion batteries using 4-isopropyl phenyl diphenyl phosphate as an additive  

Science Journals Connector (OSTI)

To enhance the thermal stability of graphite electrodes for lithium-ion batteries, 4-isopropyl phenyl diphenyl phosphate (IPPP)...6...in ethylene carbonate and diethyl carbonate (1:1 in weight). The electrochemic...

Qingsong Wang; Jinhua Sun; Chunhua Chen

2009-07-01T23:59:59.000Z

333

Moisture and temperature effects on curvature of anti-symmetric cross-ply graphite/epoxy laminates  

E-Print Network [OSTI]

MOISTURE AND TEMPERATURE EFFECTS ON CURVATURE OF ANTI-SYMMETRIC CROSS-PLY GRAPHITE/EPOXY LAMINATES A Thesis by RANDALL STEPHEN LOTT Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement... for the degree of MASTER OF SCIENCE December 1980 Major Subject: Mechanical Engineering MOISTURE AND TEMPERATURE EFFECTS ON CURVATURE OF ANTI-SYMMETRIC CROSS-PLY GRAPHITE/EPOXY LAMINATES A Thesis by RANDALL STEPHEN LOTT Approved as to style and content...

Lott, Randall Stephen

2012-06-07T23:59:59.000Z

334

Experimental investigation of moisture and temperature conditioning of C600/5208 graphite/epoxy composite material  

E-Print Network [OSTI]

I XPERIMENTAI INVESTIGATION OF MOI TURE AND TE11PERATURF CONDITIONING OF CGOO/5208 GRAPHITE/EPOXY COMPOSITE MATL'RIAL KENNETH AILEN GRIFGFR Su5&ritted to the Graduate College of Texa. s AQh University in partial fulfillment of the requirement... for the degree of MASTER OF SCIFNCE December 1979 Majo, Subject: Ae&ospace Engineering EXPERINENTAL INVESTIGATION OF MOISTURE AND TENPERATURE CONDITIONING OF C600/5208 GRAPHITE/EPOXY COMPOSITE HATERIAL A Thesis by -KENNETH ALLEN GRIEGER Approved...

Grieger, Kenneth Allen

2012-06-07T23:59:59.000Z

335

The determination of some anions using ion chromatography and ion chromatography-graphite furnace atomic absorption spectrometry  

E-Print Network [OSTI]

THE DETERMINATION OF SOME ANIONS USING ION CHROMATOGRAPHY AND ION CHROMATOGRAPHY-GRAPHITE FURNACE ATOMIC ABSORPTION SPECTROMETRY A Thesis by DANIEL C. J. HILLMAN Submitted to the Graduate College of Texas A&M University in partial fulfillment... of the requirement for the degree of MASTER OF SCIENCE August 1981 Major Subject: Chemistry THE DETERMINATION OF SOME ANIONS USING ION CHROMATOGRAPHY AND ION CHROMATOGRAPHY-GRAPHITE FURNACE ATOMIC ABSORPTION SPECTROMETRY A Thesis by DANIEL C. J. HILLMAN...

Hillman, Daniel C

1981-01-01T23:59:59.000Z

336

Continious production of exfoliated graphite composite compositions and flow field plates  

DOE Patents [OSTI]

A process of continuously producing a more isotropic, electrically conductive composite composition is provided. The process comprises: (a) continuously supplying a compressible mixture comprising exfoliated graphite worms and a binder or matrix material, wherein the binder or matrix material is in an amount of between 3% and 60% by weight based on the total weight of the mixture; (b) continuously compressing the compressible mixture at a pressure within the range of from about 5 psi or 0.035 MPa to about 50,000 psi or 350 MPa in at least a first direction into a cohered graphite composite compact; and (c) continuously compressing the composite compact in a second direction, different from the first direction, to form the composite composition in a sheet or plate form. The process leads to composite plates with exceptionally high thickness-direction electrical conductivity.

Shi, Jinjun (Columbus, OH); Zhamu, Aruna (Centerville, OH); Jang, Bor Z. (Centerville, OH)

2010-07-20T23:59:59.000Z

337

Hierarchical mesoporous/microporous carbon with graphitized frameworks for high-performance lithium-ion batteries  

SciTech Connect (OSTI)

A hierarchical meso-/micro-porous graphitized carbon with uniform mesopores and ordered micropores, graphitized frameworks, and extra-high surface area of ?2200 m{sup 2}/g, was successfully synthesized through a simple one-step chemical vapor deposition process. The commercial mesoporous zeolite Y was utilized as a meso-/ micro-porous template, and the small-molecule methane was employed as a carbon precursor. The as-prepared hierarchical meso-/micro-porous carbons have homogeneously distributed mesopores as a host for electrolyte, which facilitate Li{sup +} ions transport to the large-area micropores, resulting a high reversible lithium ion storage of 1000 mA h/g and a high columbic efficiency of 65% at the first cycle.

Lv, Yingying; Fang, Yin; Qian, Xufang; Tu, Bo [Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Laboratory of Advanced Materials, Fudan University, Shanghai 200433 (China); Wu, Zhangxiong [Department of Chemical Engineering, Monash University, Clayton, VIC 3800 (Australia); Asiri, Abdullah M. [Chemistry Department and The Center of Excellence for Advanced Materials Research, King Abdulaziz University, P.O. Box 80203, Jeddah 21589 (Saudi Arabia); Zhao, Dongyuan, E-mail: dyzhao@fudan.edu.cn [Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Laboratory of Advanced Materials, Fudan University, Shanghai 200433 (China); Department of Chemical Engineering, Monash University, Clayton, VIC 3800 (Australia)

2014-11-01T23:59:59.000Z

338

Preparation and evaluation of coal extracts as precursors for carbon and graphite products  

SciTech Connect (OSTI)

A coal extraction process coupled with coal hydrotreatment has been shown capable of producing suitable precursors for a variety of commercially important carbon and graphite products. The N-methylpyrolidone (NMP) extracts of hydrotreated coals have been analytically and chemically characterized and shown to have properties acceptable for use as binder and impregnation pitch. Mesophase formation studies have demonstrated their capability for producing both needle and anode grade coke as well as precursors for mesophase pitch fibers. A graphite artifact has been produced using a coal extract as a binder and coke derived from the extract as a filler. Further evaluation of the extract materials is being carried out by industrial members of the Carbon Products Consortium.

Zondlo, J.W.; Stiller, A.W.; Stansberry, P.G. [West Virginia Univ., Morgantown, WV (United States)] [and others

1996-08-01T23:59:59.000Z

339

Frictional melt pulses during a V1.1 Ma earthquake along the Alpine Fault, New Zealand  

E-Print Network [OSTI]

at which future catastrophic earth- quakes may originate. Our current understanding of frictional melting

340

Method to Assess the Radionuclide Inventory of Irradiated Graphite from Gas-Cooled Reactors - 13072  

SciTech Connect (OSTI)

About 17,000 t of irradiated graphite waste will be produced from the decommissioning of the six French gas-cooled nuclear reactors. Determining the radionuclide (RN) content of this waste is of relevant importance for safety reasons and in order to determine the best way to manage them. For many reasons the impurity content that gave rise to the RNs in irradiated graphite by neutron activation during operation is not always well known and sometimes actually unknown. So, assessing the RN content by the use of traditional calculation activation, starting from assumed impurity content, leads to a false assessment. Moreover, radiochemical measurements exhibit very wide discrepancies especially on RN corresponding to precursor at the trace level such as natural chlorine corresponding to chlorine 36. This wide discrepancy is unavoidable and is due to very simple reasons. The level of impurity is very low because the uranium fuel used at that very moment was not enriched, so it was a necessity to have very pure nuclear grade graphite and the very low size of radiochemical sample is a simple technical constraint because device size used to get mineralization product for measurement purpose is limited. The assessment of a radionuclide inventory only based on few number of radiochemical measurements lead in most cases, to a gross over or under-estimation that is detrimental for graphite waste management. A method using an identification calculation-measurement process is proposed in order to assess a radiological inventory for disposal sizing purpose as precise as possible while guaranteeing its upper character. This method present a closer approach to the reality of the main phenomenon at the origin of RNs in a reactor, while also incorporating the secondary effects that can alter this result such as RN (or its precursor) release during reactor operation. (authors)

Poncet, Bernard [EDF-CIDEN, 154 Avenue Thiers, CS 60018, F-69458 LYON cedex 06 (France)] [EDF-CIDEN, 154 Avenue Thiers, CS 60018, F-69458 LYON cedex 06 (France)

2013-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "melting includes graphite" 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

Oscillatory Hall Effect, Magnetoresistance, and Magnetic Susceptibility of a Graphite Single Crystal  

Science Journals Connector (OSTI)

The Hall coefficient, magnetoresistance, and magnetic susceptibility of a graphite single crystal have been measured at liquid helium temperatures and in magnetic fields up to 25 kilogauss. All three phenomena are periodic functions of reciprocal field and exhibit the same period for like orientations of the crystal axes with respect to the magnetic field. The phases however are different. Where possible, experiment and theory have been compared.

Ted G. Berlincourt and M. C. Steele

1955-05-15T23:59:59.000Z

342

Water-cooled pyrolytic graphite targets at LAMPF: design and operation  

SciTech Connect (OSTI)

Design considerations and actual operating experience are reported for water-cooled pyrolytic graphite targets at the Clinton P. Anderson Meson Physics Facility (LAMPF). Emphasis is placed on the use of finite element computer calculations to determine target temperatures and stresses, which can then be evaluated to judge the usefulness of a particular design. Consideration is also given to the swelling of the target following irradiation, and to the measures taken to prolong target lifetime.

Brown, R.D.; Grisham, D.L.

1981-01-01T23:59:59.000Z

343

Gas storage materials, including hydrogen storage materials  

DOE Patents [OSTI]

A material for the storage and release of gases comprises a plurality of hollow elements, each hollow element comprising a porous wall enclosing an interior cavity, the interior cavity including structures of a solid-state storage material. In particular examples, the storage material is a hydrogen storage material, such as a solid state hydride. An improved method for forming such materials includes the solution diffusion of a storage material solution through a porous wall of a hollow element into an interior cavity.

Mohtadi, Rana F; Wicks, George G; Heung, Leung K; Nakamura, Kenji

2014-11-25T23:59:59.000Z

344

Diffusion velocity correlation for nuclear graphite gasification at high temperature and low Reynolds numbers  

SciTech Connect (OSTI)

The safety analysis of High-Temperature and Very High Temperature gas-cooled Reactors requires reliable estimates of nuclear graphite gasification as a function of temperature, among other parameters, in the unlikely event of an air ingress accident. Although the rates of the prevailing chemical reactions increase exponentially with temperature, graphite gasification at high temperatures is limited by the oxygen diffusion through the boundary layer. The effective diffusion velocity depends on the total flow rate and pressure of the bulk air-gas mixture. This paper develops a semi-empirical Sherwood number correlation for calculating the oxygen diffusion velocity. The correlation is based on a compiled database of the results of convective heat transfer experiments with wires and cylinders of different diameters in air, water and paraffin oil at 0.006 {<=} Re {<=} 1,604 and 0.068 {<=} Sc {<=} 35.2, and of mass transfer experiments at 4.8 {<=} Re {<=} 77 and 1,300 {<=} Sc {<=} 2,000. The developed correlation is within {+-} 8% of the compiled database of 567 data points and consistent with reported gasification rate measurements at higher temperatures in experiments using different size specimens of nuclear graphite grades of NBG-18 and NB-25, IG-11, IG-110 and IG-430 in atmospheric air at 0.08 {<=} Re {<=} 30. Unlike the Graetz solution that gives a constant Sh of 3.66 at Re {<=} 1.0, the present correlation shows Sh decreases monotonically to much lower values with decreasing Re. (authors)

El-Genk, M. S. [Inst. for Space and Nuclear Power Studies, Univ. of New Mexico, Albuquerque, NM (United States); Chemical and Nuclear Engineering Dept., Univ. of New Mexico, Albuquerque, NM (United States); Mechanical Engineering Dept., Univ. of New Mexico, Albuquerque, NM (United States); Tournier, J. M. P. [Inst. for Space and Nuclear Power Studies, Univ. of New Mexico, Albuquerque, NM (United States); Chemical and Nuclear Engineering Dept., Univ. of New Mexico, Albuquerque, NM (United States)

2012-07-01T23:59:59.000Z

345

Modeling Stress Strain Relationships and Predicting Failure Probabilities For Graphite Core Components  

SciTech Connect (OSTI)

This project will implement inelastic constitutive models that will yield the requisite stress-strain information necessary for graphite component design. Accurate knowledge of stress states (both elastic and inelastic) is required to assess how close a nuclear core component is to failure. Strain states are needed to assess deformations in order to ascertain serviceability issues relating to failure, e.g., whether too much shrinkage has taken place for the core to function properly. Failure probabilities, as opposed to safety factors, are required in order to capture the bariability in failure strength in tensile regimes. The current stress state is used to predict the probability of failure. Stochastic failure models will be developed that can accommodate possible material anisotropy. This work will also model material damage (i.e., degradation of mechanical properties) due to radiation exposure. The team will design tools for components fabricated from nuclear graphite. These tools must readily interact with finite element software--in particular, COMSOL, the software algorithm currently being utilized by the Idaho National Laboratory. For the eleastic response of graphite, the team will adopt anisotropic stress-strain relationships available in COMSO. Data from the literature will be utilized to characterize the appropriate elastic material constants.

Duffy, Stephen

2013-09-09T23:59:59.000Z

346

Production yields of noble-gas isotopes from ISOLDE UC$_{x}$/graphite targets  

E-Print Network [OSTI]

Yields of He, Ne, Ar, Kr and Xe isotopic chains were measured from UC$_{x}$/graphite and ThC$_{x}$/graphite targets at the PSB-ISOLDE facility at CERN using isobaric selectivity achieved by the combination of a plasma-discharge ion source with a water-cooled transfer line. %The measured half-lives allowed %to calculate the decay losses of neutron-rich isotopes in the %target and ion-source system, and thus to obtain information on the in-target %productions from the measured yields. The delay times measured for a UC$_x$/graphite target allow for an extrapolation to the expected yields of very neutron-rich noble gas isotopes, in particular for the ``NuPECC reference elements'' Ar and Kr, at the next-generation radioactive ion-beam facility EURISOL. \\end{abstract} \\begin{keyword} % keywords here, in the form: keyword \\sep keyword radioactive ion beams \\sep release \\sep ion yields \\sep ISOL (Isotope Separation On-Line) \\sep uranium and thorium carbide targets. % PACS codes here, in the form: \\PACS code \\sep code...

Bergmann, U C; Catherall, R; Cederkäll, J; Diget, C A; Fraile-Prieto, L M; Franchoo, S; Fynbo, H O U; Gausemel, H; Georg, U; Giles, T; Hagebř, E; Jeppesen, H B; Jonsson, O C; Köster, U; Lettry, Jacques; Nilsson, T; Peräjärvi, K; Ravn, H L; Riisager, K; Weissman, L; Äystö, J

2003-01-01T23:59:59.000Z

347

Effect of glass composition on activation energy of viscosity in glass-melting-temperature range  

SciTech Connect (OSTI)

In the high-temperature range, where the viscosity (Eta) of molten glass is <10{sup 3} Pa s, the activation energy (B) is virtually ln(Eta) = A + B/T, is nearly independent of melt composition. Hence, the viscosity-composition relationship for Eta < 10{sup 3} Pa s is defined by B as a function of composition. Using a database encompassing over 1300 compositions of high-level waste glasses with nearly 7000 viscosity data, we developed mathematical models for B(x), where x is the composition vector in terms of mass fractions of components. In this paper, we present 13 versions of B(x) as first- and second-order polynomials with coefficients for 15 to 39 components, including Others, a component that sums constituents having little effect on viscosity.

Hrma, Pavel R.; Han, Sang Soo

2012-08-01T23:59:59.000Z

348

Method to decrease loss of aluminum and magnesium melts  

DOE Patents [OSTI]

A method to minimize oxidation of metal during melting processes is provided, the method comprising placing solid phase metal into a furnace environ-ment, transforming the solid-phase metal into molten metal phase having a molten metal surface, and creating a barrier between the surface and the environment. Also provided is a method for isolating the surface of molten metal from its environment, the method comprising confining the molten metal to a controlled atmos-phere, and imposing a floating substrate between the surface and the atmosphere.

Hryn, John N. (Naperville, IL); Pellin, Michael J. (Naperville, IL); Calaway, Jr., Wallis F. (Woodridge, IL); Moore, Jerry F. (Naperville, IL); Krumdick, Gregory K. (Crete, IL)

2002-01-01T23:59:59.000Z

349

Hydrostatic extrusion of Cu-Ag melt spun ribbon  

DOE Patents [OSTI]

The present invention provides a method of producing high-strength and high-conductance copper and silver materials comprising the steps of combining a predetermined ratio of the copper with the silver to produce a composite material, and melt spinning the composite material to produce a ribbon of copper and silver. The ribbon of copper and silver is heated in a hydrogen atmosphere, and thereafter die pressed into a slug. The slug then is placed into a high-purity copper vessel and the vessel is sealed with an electron beam. The vessel and slug then are extruded into wire form using a cold hydrostatic extrusion process.

Hill, Mary Ann (Los Alamos, NM); Bingert, John F. (Jemez Springs, NM); Bingert, Sherri A. (Jemez Springs, NM); Thoma, Dan J. (Los Alamos, NM)

1998-01-01T23:59:59.000Z

350

Hydrostatic extrusion of Cu-Ag melt spun ribbon  

DOE Patents [OSTI]

The present invention provides a method of producing high-strength and high-conductance copper and silver materials comprising the steps of combining a predetermined ratio of the copper with the silver to produce a composite material, and melt spinning the composite material to produce a ribbon of copper and silver. The ribbon of copper and silver is heated in a hydrogen atmosphere, and thereafter die pressed into a slug. The slug then is placed into a high-purity copper vessel and the vessel is sealed with an electron beam. The vessel and slug then are extruded into wire form using a cold hydrostatic extrusion process. 5 figs.

Hill, M.A.; Bingert, J.F.; Bingert, S.A.; Thoma, D.J.

1998-09-08T23:59:59.000Z

351

Effect of Size Polydispersity on Melting of Charged Colloidal Systems  

E-Print Network [OSTI]

We introduce simple prescriptions of the Yukawa potential to describe the effect of size polydispersity and macroion shielding effect in charged colloidal systems. The solid-liquid phase boundaries were presented with the Lindemann criterion based on molecular dynamics simulations. Compared with the Robbins-Kremer-Grest simulation results, a deviation of melting line is observed at small $\\lambda$, which means large macroion screening length. This deviation of phase boundary is qualitatively consistent with the simulation result of the nonlinear Poisson-Boltzmann equation with full many-body interactions. It is found that this deviation of the solid-liquid phase behaviour is sensitive to the screening parameter.

Yong Chen

2006-03-10T23:59:59.000Z

352

Intentionally Including - Engaging Minorities in Physics Careers |  

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

Intentionally Including - Engaging Minorities in Physics Careers Intentionally Including - Engaging Minorities in Physics Careers Intentionally Including - Engaging Minorities in Physics Careers April 24, 2013 - 4:37pm Addthis Joining Director Dot Harris (second from left) were Marlene Kaplan, the Deputy Director of Education and director of EPP, National Oceanic and Atmospheric Administration, Claudia Rankins, a Program Officer with the National Science Foundation and Jim Stith, the past Vice-President of the American Institute of Physics Resources. Joining Director Dot Harris (second from left) were Marlene Kaplan, the Deputy Director of Education and director of EPP, National Oceanic and Atmospheric Administration, Claudia Rankins, a Program Officer with the National Science Foundation and Jim Stith, the past Vice-President of the

353

Scramjet including integrated inlet and combustor  

SciTech Connect (OSTI)

This patent describes a scramjet engine. It comprises: a first surface including an aft facing step; a cowl including: a leading edge and a trailing edge; an upper surface and a lower surface extending between the leading edge and the trailing edge; the cowl upper surface being spaced from and generally parallel to the first surface to define an integrated inlet-combustor therebetween having an inlet for receiving and channeling into the inlet-combustor supersonic inlet airflow; means for injecting fuel into the inlet-combustor at the step for mixing with the supersonic inlet airflow for generating supersonic combustion gases; and further including a spaced pari of sidewalls extending between the first surface to the cowl upper surface and wherein the integrated inlet-combustor is generally rectangular and defined by the sidewall pair, the first surface and the cowl upper surface.

Kutschenreuter, P.H. Jr.; Blanton, J.C.

1992-02-04T23:59:59.000Z

354

Transmission line including support means with barriers  

DOE Patents [OSTI]

A gas insulated transmission line includes an elongated outer sheath, a plurality of inner conductors disposed within and extending along the outer sheath, and an insulating gas which electrically insulates the inner conductors from the outer sheath. A support insulator insulatably supports the inner conductors within the outer sheath, with the support insulator comprising a main body portion including a plurality of legs extending to the outer sheath, and barrier portions which extend between the legs. The barrier portions have openings therein adjacent the main body portion through which the inner conductors extend.

Cookson, Alan H. (Pittsburgh, PA)

1982-01-01T23:59:59.000Z

355

Numerical study of convection heat transfer during the melting of ice in a porous layer  

SciTech Connect (OSTI)

A numerical study is made of the melting of ice in a rectangular porous cavity heated from above. The Landau transformation is used to immobilize the ice-water interface, and the Darcy-Boussinesq equations are solved by a finite-difference technique. Results are analyzed in terms of the heating temperature and the aspect ratio of the cavity. A comparison is made with the case of melting from below. It was found that melting from above is more effective than melting from below when the heating temperature is between 0 and 8 C: convection arises earlier, the melting process is faster, and the total melt at steady state is thicker. The critical time for onset of convection is minimum when the upper boundary is heated at 6 C. At this heating temperature, one also obtains a maximum heat transfer rate (Nusselt number).

Zhang, X.; Nguyen, T.H. (Ecole Polytechnique de Montreal, Quebec (Canada). Dept. of Mechanical Engineering)

1994-05-01T23:59:59.000Z

356

Energy Consumption of Personal Computing Including Portable  

E-Print Network [OSTI]

Energy Consumption of Personal Computing Including Portable Communication Devices Pavel Somavat1 consumption, questions are being asked about the energy contribution of computing equipment. Al- though studies have documented the share of energy consumption by this type of equipment over the years, research

Namboodiri, Vinod

357

EE Regional Technology Roadmap Includes comparison  

E-Print Network [OSTI]

EE Regional Technology Roadmap Includes comparison against 6th Power Plan (Update cyclically Roadmap with a strong linkage to utility programs Scan for Technologies 1. How does it address the NW Data Clearinghouse BPA/RTF NEEA/Regional Programs Group Update Regional EE Technology Roadmap Lighting

358

Video Topics Include Freshman Inquiry Course  

E-Print Network [OSTI]

Video Topics Include Freshman Inquiry Course Open Advisement/ Group Advisement Dinning Campus: End of Spring 2012, Commencement May 18: Grades available on MAX after 4:30pm AdvisementYouTubeVideoSeries I N S I D E T H I S I S S U E : YouTube Video Series 1 Mark Your Calendar 1 Exploring Major Tips 2

Hardy, Christopher R.

359

Including Ocean Model Uncertainties in Climate Predictions  

E-Print Network [OSTI]

Including Ocean Model Uncertainties in Climate Predictions Chris Brierley, Alan Thorpe, Mat Collins's to perform the integrations Currently uses a `slab' ocean #12;An Ocean Model Required to accurately model transient behaviour Will have its own uncertainties Requires even more computing power Create new models

Jones, Peter JS

360

Electrical charging during the sharkskin instability of a metallocene melt  

E-Print Network [OSTI]

Flow instabilities are widely studied because of their economical and theoretical interest, however few results have been published about the polymer electrification during the extrusion. Nevertheless the generation of the electrical charges is characteristic of the interaction between the polymer melt and the die walls. In our study, the capillary extrusion of a metallocene polyethylene (mPE) through a tungsten carbide die is characterized through accurate electrical measurements thanks a Faraday pail. No significant charges are observed since the extrudate surface remains smooth. However, as soon as the sharkskin distortion appears, measurable charges are collected (around 5 10-8 C/m2). Higher level of charges are measured during the spurt or the gross-melt fracture (g.m.f) defects. This work is focused on the electrical charging during the sharkskin instability. The variation of the electrical charges versus the apparent wall shear stress is investigated for different die geometries. This curve exhibits a linear increase, followed by a sudden growth just before the onset of the spurt instability. This abrupt charging corresponds also to the end of the sharkskin instability. It is also well-known that wall slip appears just at the same time, with smaller velocity values than during spurt flow. Our results indicate that electrification could be a signature of the wall slip. We show also that the electrification curves can be shifted according to the time-temperature superposition principle, leading to the conclusion that molecular features of the polymer are also involved in this process.

S. Tonon; A. Lavernhe-Gerbier; F. Flores; A. Allal; C. Guerret-Piécourt

2007-07-18T23:59:59.000Z

Note: This page contains sample records for the topic "melting includes graphite" 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

Microwires fabricated by glass-coated melt spinning  

SciTech Connect (OSTI)

The glass-coated melt spinning method offers a route for the manufacture of metal filaments with a few micrometers in diameter in a single operation directly from the melt. Cobalt-based amorphous wires, Cu-15.0 atomic percent (at. %) Sn shape-memory wires, and Ni{sub 2}MnGa (atomic percent) ferromagnetic wires were successfully produced by this method. The cobalt-based amorphous wire is flexible, and Cu-15.0 at. % Sn shape-memory wires have the tensile elongation of 14%. However, because of chemical reaction with glass and oxidation, it is hard to make Cu–Al–Ni shape-memory wires and Ni–Nb–Sn amorphous wires. Conditions for preparing these materials were summarized, and the differences of the solidification processes among glass-coated amorphous cobalt-based wires, Cu-15.0 at. % Sn shape-memory wires, and Ni{sub 2}MnGa wires were analyzed and discussed.

Zhao, Y. Y.; Li, H.; Hao, H. Y.; Li, M.; Zhang, Y. [State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, No. 30, Xueyuan Road, Beijing 100083 (China)] [State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, No. 30, Xueyuan Road, Beijing 100083 (China); Liaw, P. K. [Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996-2200 (United States)] [Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996-2200 (United States)

2013-07-15T23:59:59.000Z

362

Gamma titanium aluminide production using the Induction Skull Melting (ISM) process  

SciTech Connect (OSTI)

Since 1985, more than 2,000 titanium aluminide heats have been produced using the Induction Skull Melting (ISM) process. The history of ISM/Gamma production will be discussed in this paper. Gamma titanium aluminide processing with Induction Skull Melting offers many advantages over other types of reactive alloy melting methods. These advantages will be discussed as well as drawbacks. Also, potential markets and applications for ISM/Gamma will be presented.

Reed, S. [Duriron Co., Inc., Dayton, OH (United States)

1995-12-31T23:59:59.000Z

363

A model for the latent heat of melting in free standing metal nanoparticles  

SciTech Connect (OSTI)

Nanoparticles of many metals are known to exhibit scale dependent latent heats of melting. Analytical models for this phenomenon have so far failed to completely capture the observed phenomena. Here we present a thermodynamic analysis for the melting of metal nanoparticles in terms of their internal energy and a scale dependent surface tension proposed by Tolman. The resulting model predicts the scale dependence of the latent heat of melting and is confirmed using published data for tin and aluminum.

Shin, Jeong-Heon; Deinert, Mark R., E-mail: mdeinert@mail.utexas.edu [Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78715 (United States)

2014-04-28T23:59:59.000Z

364

Removing a sheet from the surface of a melt using elasticity and buoyancy  

DOE Patents [OSTI]

Embodiments related to sheet production are disclosed. A melt of a material is cooled to form a sheet of the material on the melt. The sheet is formed in a first region at a first sheet height. The sheet is translated to a second region such that it has a second sheet height higher than the first sheet height. The sheet is then separated from the melt. A seed wafer may be used to form the sheet.

Kellerman, Peter L.; Sun, Dawei; Helenbrook, Brian; Harvey, David S.

2014-07-01T23:59:59.000Z

365

Procedure for determining the rate of penetration of melts into materials of capillary porosity  

Science Journals Connector (OSTI)

A procedure is proposed for determining the rate of infiltration of melts into porous materials from the change in the electrical resistance of the latter.

M. A. Sherstobitov; S. I. Popel'…

1965-08-01T23:59:59.000Z

366

E-Print Network 3.0 - aphanitic melt rocks Sample Search Results  

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

emplacement; (2) we... KIMBERLITE MELT CHEMISTRY Table 1: Jericho ... Source: Russell, Kelly - Department of Earth and Ocean Sciences, University of British Columbia Collection:...

367

Microsoft PowerPoint - ESGCold Cap Melting (2) [Read-Only  

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

Pre-Treatment Facility HLW Vitrification Facility LAW Vitrification Facility Outline * Glass-melting furnace (melter) and cold cap (batch blanket) * Melter feed conversion to...

368

E-Print Network 3.0 - activity glass melts Sample Search Results  

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

Volume 85, pages 397406, 2000 0003-004X00030439705.00 397 Summary: : PHENOMENOLOGY OF OXIDATION IN FE-BEARING ALUMINOSILICATE MELTS AND GLASSES Chemical diffusion in...

369

Buildings Included on EMS Reports"  

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

Office of Legacy Management Office of Legacy Management Buildings Included on EMS Reports" "Site","Property Name","Property ID","GSF","Incl. in Water Baseline (CY2007)","Water Baseline (sq. ft.)","Water CY2008 (sq. ft.)","Water CY2009 (sq. ft.)","Water Notes","Incl. in Energy Baseline (CY2003)","Energy Baseline (sq. ft.)","CY2008 Energy (sq. ft.)","CY2009 Energy (sq. ft.)","Energy Notes","Included as Existing Building","CY2008 Existing Building (sq. ft.)","Reason for Building Exclusion" "Column Totals",,"Totals",115139,,10579,10579,22512,,,3183365,26374,115374,,,99476 "Durango, CO, Disposal/Processing Site","STORAGE SHED","DUD-BLDG-STORSHED",100,"no",,,,,"no",,,,"OSF","no",,"Less than 5,000 GSF"

370

Energy-Saving Melting and Revert Reduction Technology (E-SMARRT): Final Summary Report  

SciTech Connect (OSTI)

Energy-Saving Melting and Revert Reduction Technology (E-SMARRT) is a balanced portfolio of R&D tasks that address energy-saving opportunities in the metalcasting industry. E-SMARRT was created to: • Improve important capabilities of castings • Reduce carbon footprint of the foundry industry • Develop new job opportunities in manufacturing • Significantly reduce metalcasting process energy consumption and includes R&D in the areas of: • Improvements in Melting Efficiency • Innovative Casting Processes for Yield Improvement/Revert Reduction • Instrumentation and Control Improvement • Material properties for Casting or Tooling Design Improvement The energy savings and process improvements developed under E-SMARRT have been made possible through the unique collaborative structure of the E-SMARRT partnership. The E-SMARRT team consisted of DOE’s Office of Industrial Technology, the three leading metalcasting technical associations in the U.S: the American Foundry Society; the North American Die Casting Association; and the Steel Founders’ Society of America; and SCRA Applied R&D, doing business as the Advanced Technology Institute (ATI), a recognized leader in distributed technology management. This team provided collaborative leadership to a complex industry composed of approximately 2,000 companies, 80% of which employ less than 100 people, and only 4% of which employ more than 250 people. Without collaboration, these new processes and technologies that enable energy efficiencies and environment-friendly improvements would have been slow to develop and had trouble obtaining a broad application. The E-SMARRT R&D tasks featured low-threshold energy efficiency improvements that are attractive to the domestic industry because they do not require major capital investment. The results of this portfolio of projects are significantly reducing metalcasting process energy consumption while improving the important capabilities of metalcastings. Through June 2014, the E-SMARRT program predicts an average annual estimated savings of 59 Trillion BTUs per year over a 10 year period through Advanced Melting Efficiencies and Innovative Casting Processes. Along with these energy savings, an estimated average annual estimate of CO2 reduction per year over a ten year period is 3.56 Million Metric Tons of Carbon Equivalent (MM TCE).

White, Thornton C [SCRA Appiled R& D

2014-03-31T23:59:59.000Z

371

Power generation method including membrane separation  

DOE Patents [OSTI]

A method for generating electric power, such as at, or close to, natural gas fields. The method includes conditioning natural gas containing C.sub.3+ hydrocarbons and/or acid gas by means of a membrane separation step. This step creates a leaner, sweeter, drier gas, which is then used as combustion fuel to run a turbine, which is in turn used for power generation.

Lokhandwala, Kaaeid A. (Union City, CA)

2000-01-01T23:59:59.000Z

372

Completion strategy includes clay and precipitate control  

SciTech Connect (OSTI)

This article describes the conditions which are necessary for a successful oil well completion in the Mississippi and Cherokee zones of South Central Kansas. Topics considered include paraffin precipitation, clay swelling and migration, and iron precipitation. Clays in these zones are sensitive to water-base treating fluids and tend to swell and migrate to the well bore, thereby causing permeability damage. The presence of iron in the Mississippi and Cherokee formations has been indicated by cuttings, core samples, and connate water samples.

Sandy, T.; Gardner, G.R.

1985-05-06T23:59:59.000Z

373

Jet-calculus approach including coherence effects  

Science Journals Connector (OSTI)

We show how integrodifferential equations typical of jet calculus can be combined with an averaging procedure to obtain jet-calculus-based results including the Mueller interference graphs. Results in longitudinal-momentum fraction x for physical quantities are higher at intermediate x and lower at large x than with the conventional ‘‘incoherent’’ jet calculus. These results resemble those of Marchesini and Webber, who used a Monte Carlo approach based on the same dynamics.

L. M. Jones; R. Migneron; K. S. S. Narayanan

1987-01-01T23:59:59.000Z

374

Call for PhD Studentship Proposals for September 2013 start Title of Project: Impact melting and vaporization of planets including the proto-Earth  

E-Print Network [OSTI]

. Kathleen Davis 2005 100% Geoscientist, Shell Explor. & Prod. Sun Ni 2008 100% HSBC, Operations Analysis

Stixrude, Lars

375

Questions and Answers - What's the melting point of steel?  

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

If you jumped into a pool of liquid oxygen,would your body instantly crystallize? If you jumped into a pool of liquid oxygen,<br>would your body instantly crystallize? Previous Question (If you jumped into a pool of liquid oxygen, would your body instantly crystallize?) Questions and Answers Main Index Next Question (What is a material with a freezing point above 0 degrees Celsius?) What is a material with a freezingpoint above 0 degrees Celsius? What's the melting point of steel? That depends on the alloy of steel you are talking about. The term alloy is almost always used incorrectly these days, especially amongst bicyclists. They use the term to mean aluminum. What the term alloy really means is a mixture of metals, any kind of metals. Almost all metal used today is a mixture and therefore an alloy. Most steel has other metals added to tune its properties, like strength,

376

Grain misorientation in thixo-billets prepared by melt stirring  

SciTech Connect (OSTI)

For semi solid metal (SSM) slurries, in addition to the morphology, size, distribution and percentage of the solid phase particles, the microstructure of individual solid particles is another important parameter to be considered. This is particularly an issue when SSM billets are prepared by continuous stirring of the melt to temperatures below liquidus, as in the case of electromagnetic stirring of Al-Si alloys. Microstructural evolution of the electromagnetically stirred Al-Si alloy is investigated by means of optical and electron microscopy. Electron backscatter diffraction (EBSD) analysis of the stirred and unstirred cast billets has shown stirring to generate local misorientation within individual solid particles. This is an indication of growing dendrites undergoing plastic deformation during the course of SSM slurry preparation. The formation of dislocations and their subsequent rearrangement into subgrain boundaries has been shown by EBSD analysis and TEM studies of thin foil specimens respectively.

Nafisi, S., E-mail: Shahrooz.Nafisi@evrazincna.com [Facility for Electron Microscopy Research, McGill University, Montreal, Quebec, H3A 2B2 (Canada); Department of Metals and Materials Engineering, McGill University, Montreal, Quebec, H3A 2B2 (Canada); Szpunar, J. [Department of Metals and Materials Engineering, McGill University, Montreal, Quebec, H3A 2B2 (Canada); Vali, H. [Facility for Electron Microscopy Research, McGill University, Montreal, Quebec, H3A 2B2 (Canada); Ghomashchi, R. [Sunday Solar Technologies, 62 Jack Williams Drive Penrith, NSW 2750 (Australia)

2009-09-15T23:59:59.000Z

377

Determining whether metals nucleate homogeneously on graphite: A case study with copper  

SciTech Connect (OSTI)

We observe that Cu clusters grow on surface terraces of graphite as a result of physical vapor deposition in ultrahigh vacuum. We show that the observation is incompatible with a variety of models incorporating homogeneous nucleation and calculations of atomic-scale energetics. An alternative explanation, ion-mediated heterogeneous nucleation, is proposed and validated, both with theory and experiment. This serves as a case study in identifying when and whether the simple, common observation of metal clusters on carbon-rich surfaces can be interpreted in terms of homogeneous nucleation. We describe a general approach for making system-specific and laboratory-specific predictions.

Appy, David [Ames Laboratory; Lei, Huaping [Ames Laboratory; Han, Yong [Ames Laboratory; Wang, Cai-Zhuang [Ames Laboratory; Tringides, Michael C [Ames Laboratory; Shao, Dahai [Ames Laboratory; Kwolek, Emma J [Iowa State University; Evans, J W [Ames Laboratory; Thiel, P A [Ames Laboratory

2014-11-01T23:59:59.000Z

378

Synthesis of graphene nanoribbons from amyloid templates by gallium vapor-assisted solid-phase graphitization  

SciTech Connect (OSTI)

Single- and double-layer graphene nanoribbons (GNRs) with widths of around 10?nm were synthesized directly onto an insulating substrate by solid-phase graphitization using a gallium vapor catalyst and carbon templates made of amyloid fibrils. Subsequent investigation revealed that the crystallinity, conductivity, and carrier mobility were all improved by increasing the temperature of synthesis. The carrier mobility of the GNR synthesized at 1050?°C was 0.83 cm{sup 2}/V?s, which is lower than that of mechanically exfoliated graphene. This is considered to be most likely due to electron scattering by the defects and edges of the GNRs.

Murakami, Katsuhisa, E-mail: k.murakami@bk.tsukuba.ac.jp; Dong, Tianchen; Kajiwara, Yuya; Takahashi, Teppei; Fujita, Jun-ichi [Institute of Applied Physics, Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573 (Japan); Tsukuba Research Center for Interdisciplinary Materials Science, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573 (Japan); Hiyama, Takaki; Takai, Eisuke; Ohashi, Gai; Shiraki, Kentaro [Institute of Applied Physics, Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573 (Japan)

2014-06-16T23:59:59.000Z

379

Comparison of the electrochemical properties of several commercial graphites with a templated disordered carbon  

SciTech Connect (OSTI)

A templated carbon was prepared by the pyrolysis of pyrene impregnated into pillared clay (PILC). The electrochemical performance of this was evaluated with the goal of using this material as an anode in Li-ion cells. The reversible capacity was measured as a function of C rate and the cycling characteristics were determined for various intercalation protocols. The performance of this material was compared to that of several commercial graphites tested under the same conditions. The PILC carbon shows great promise as a Li-ion anode if the fade and first-cycle losses can be controlled.

GUIDOTTI,RONALD A.; REINHARDT,FREDERICK W.; SANDI,GISELLE

2000-03-22T23:59:59.000Z

380

Comparison of the electrochemical properties of several commercial graphites with a templated disordered carbon  

SciTech Connect (OSTI)

A templated carbon was prepared by the pyrolysis of pyrene impregnated into pillared clay (PILC). The electrochemical performance of this was evaluated with the goal of using this material as an anode in Li-ion cells. The reversible capacity was measured as a function of C rate and the cycling characteristics were determined for various intercalation protocols. The performance of this material was compared to that of several commercial graphites tested under the same conditions. The PILC carbon shows great promise as a Li-ion anode if the fade and first-cycle losses can be controlled.

Guidotti, R. A.; Reinhardt, F. W.; Sandi, G.

2000-04-11T23:59:59.000Z

Note: This page contains sample records for the topic "melting includes graphite" 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

Optical panel system including stackable waveguides  

DOE Patents [OSTI]

An optical panel system including stackable waveguides is provided. The optical panel system displays a projected light image and comprises a plurality of planar optical waveguides in a stacked state. The optical panel system further comprises a support system that aligns and supports the waveguides in the stacked state. In one embodiment, the support system comprises at least one rod, wherein each waveguide contains at least one hole, and wherein each rod is positioned through a corresponding hole in each waveguide. In another embodiment, the support system comprises at least two opposing edge structures having the waveguides positioned therebetween, wherein each opposing edge structure contains a mating surface, wherein opposite edges of each waveguide contain mating surfaces which are complementary to the mating surfaces of the opposing edge structures, and wherein each mating surface of the opposing edge structures engages a corresponding complementary mating surface of the opposite edges of each waveguide.

DeSanto, Leonard (Dunkirk, MD); Veligdan, James T. (Manorville, NY)

2007-11-20T23:59:59.000Z

382

Thermovoltaic semiconductor device including a plasma filter  

DOE Patents [OSTI]

A thermovoltaic energy conversion device and related method for converting thermal energy into an electrical potential. An interference filter is provided on a semiconductor thermovoltaic cell to pre-filter black body radiation. The semiconductor thermovoltaic cell includes a P/N junction supported on a substrate which converts incident thermal energy below the semiconductor junction band gap into electrical potential. The semiconductor substrate is doped to provide a plasma filter which reflects back energy having a wavelength which is above the band gap and which is ineffectively filtered by the interference filter, through the P/N junction to the source of radiation thereby avoiding parasitic absorption of the unusable portion of the thermal radiation energy.

Baldasaro, Paul F. (Clifton Park, NY)

1999-01-01T23:59:59.000Z

383

Critical point anomalies include expansion shock waves  

SciTech Connect (OSTI)

From first-principle fluid dynamics, complemented by a rigorous state equation accounting for critical anomalies, we discovered that expansion shock waves may occur in the vicinity of the liquid-vapor critical point in the two-phase region. Due to universality of near-critical thermodynamics, the result is valid for any common pure fluid in which molecular interactions are only short-range, namely, for so-called 3-dimensional Ising-like systems, and under the assumption of thermodynamic equilibrium. In addition to rarefaction shock waves, diverse non-classical effects are admissible, including composite compressive shock-fan-shock waves, due to the change of sign of the fundamental derivative of gasdynamics.

Nannan, N. R., E-mail: ryan.nannan@uvs.edu [Mechanical Engineering Discipline, Anton de Kom University of Suriname, Leysweg 86, PO Box 9212, Paramaribo, Suriname and Process and Energy Department, Delft University of Technology, Leeghwaterstraat 44, 2628 CA Delft (Netherlands); Guardone, A., E-mail: alberto.guardone@polimi.it [Department of Aerospace Science and Technology, Politecnico di Milano, Via La Masa 34, 20156 Milano (Italy); Colonna, P., E-mail: p.colonna@tudelft.nl [Propulsion and Power, Delft University of Technology, Kluyverweg 1, 2629 HS Delft (Netherlands)

2014-02-15T23:59:59.000Z

384

Complex shell model representation including antibound states  

Science Journals Connector (OSTI)

A generalization of the complex shell model formalism is presented that includes antibound states in the basis. These states, together with bound states, Gamow states, and the continuum background, represented by properly chosen scattering waves, form a representation in which all states are treated on the same footing. Two-particle states are evaluated within this formalism, and observable two-particle resonances are defined. The formalism is illustrated in the well-known case of Li11 in its bound ground state and in Ca70(g.s.), which is also bound. Both cases are found to have a halo structure. These halo structures are described within the generalized complex shell model. We investigated the formation of two-particle resonances in these nuclei, but no evidence of such resonances was found.

R. Id Betan; R. J. Liotta; N. Sandulescu; T. Vertse; R. Wyss

2005-11-30T23:59:59.000Z

385

Comparison of different melting temperature calculation methods for short DNA sequences  

Science Journals Connector (OSTI)

......analysis of optical melting curves for a variety of short synthetic DNA duplexes and are the most commonly used by the scientific...of optical melting curves for a vari-ety of short synthetic DNA duplexes and are the most commonly used by the scientific......

Alejandro Panjkovich; Francisco Melo

2005-03-01T23:59:59.000Z

386

The Purification of Water by Zone Melting: A Phase Diagram Interpretation  

Science Journals Connector (OSTI)

The Purification of Water by Zone Melting: A Phase Diagram Interpretation ... The author comments on the application of zone melting to the purification of water from aqueous NaCl solutions by giving an interpretation of some results taking into account the binary phase diagram. ... Water / Water Chemistry ...

Mohamed Jemal

2004-07-01T23:59:59.000Z

387

NUMERICAL FORECAST OF THE MELTING AND THERMAL HISTORIES OF PARTICLES INJECTED IN A PLASMA JET  

E-Print Network [OSTI]

NUMERICAL FORECAST OF THE MELTING AND THERMAL HISTORIES OF PARTICLES INJECTED IN A PLASMA JET Jorge of the melting process of a particle injected in a plasma jet. The plasma process is nowadays applied to produce devices. Among the different coating systems, the thermal barrier coatings (TBCs) are commonly used

Paris-Sud XI, Université de

388

Thermomechanical response of a semicrystalline polymer in the vicinity of the melting by using microcantilever technology  

SciTech Connect (OSTI)

The melting transition of a model semicrystalline polymer has been detected by the microcantilever deflection as a function of temperature. Deflection measurements were done on arrays of 8-cantilevers spin coated with the semicrystalline polymer: poly (propylene azelate). The melting of the polymer has been corroborated by grazing incidence wide angle x-ray scattering experiments performed with synchrotron radiation over a single cantilever.

Soccio, M.; Rueda, D. R.; García-Gutiérrez, M. C.; Ezquerra, T. A., E-mail: t.ezquerra@csic.es [Instituto de Estructura de la Materia, IEM-CSIC, Serrano 121, Madrid (Spain); Luongo, G. [Department of Materials, Imperial College London, London SW7 2AZ (United Kingdom); Esteves, C.; Salvador-Matar, A.; Ahumada, O. [MECWINS, Calle de Santiago Grisolía, No. 2, 28760 Tres Cantos, Madrid (Spain); Lotti, N.; Munari, A. [Dipartimento di Ingegneria Civile, Chimica, Ambientale e dei Materiali, Universitá di Bologna, Via Terracini 28, Bologna 40131 (Italy)

2014-06-23T23:59:59.000Z

389

Lattice Boltzmann model for melting with natural convection Christian Huber a,*, Andrea Parmigiani b  

E-Print Network [OSTI]

Lattice Boltzmann model for melting with natural convection Christian Huber a,*, Andrea Parmigiani Boltzmann Heat transfer Melting Convection a b s t r a c t We develop a lattice Boltzmann method to couple and Stefan numbers) over which the correlations have been tested remains limited. The lattice Boltzmann

Manga, Michael

390

DSC Evidence for Microstructure and Phase Transitions in Polyethylene Melts at High Temperatures  

E-Print Network [OSTI]

DSC Evidence for Microstructure and Phase Transitions in Polyethylene Melts at High Temperatures polyethylenes of types HDPE, LDPE, and LLDPE. DSC data were obtained for a range of heating and cooling rates previous rheology findings of order and high-temperature transitions in polyethylene melts. Introduction

Hussein, Ibnelwaleed A.

391

Melting processes of oligomeric ? and ? isotactic polypropylene crystals at ultrafast heating rates  

SciTech Connect (OSTI)

The melting behaviors of ? (stable) and ? (metastable) isotactic polypropylene (iPP) crystals at ultrafast heating rates are simulated with atomistic molecular dynamics method. Quantitative information about the melting processes of ?- and ?-iPP crystals at atomistic level is achieved. The result shows that the melting process starts from the interfaces of lamellar crystal through random dislocation of iPP chains along the perpendicular direction of lamellar crystal structure. In the melting process, the lamellar crystal gradually expands but the corresponding thickness decreases. The analysis shows that the system expansion lags behind the crystallinity decreasing and the lagging extents for ?- and ?-iPP are significantly different. The apparent melting points of ?- and ?-iPP crystals rise with the increase of the heating rate and lamellar crystal thickness. The apparent melting point of ?-iPP crystal is always higher than that of ?-iPP at differently heating rates. Applying the Gibbs-Thomson rule and the scaling property of the melting kinetics, the equilibrium melting points of perfect ?- and ?-iPP crystals are finally predicted and it shows a good agreement with experimental result.

Ji, Xiaojing [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China)] [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); He, Xuehao, E-mail: xhhe@tju.edu.cn, E-mail: scjiang@tju.edu.cn [Department of Chemistry, School of Science, Tianjin University, and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072 (China)] [Department of Chemistry, School of Science, Tianjin University, and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072 (China); Jiang, Shichun, E-mail: xhhe@tju.edu.cn, E-mail: scjiang@tju.edu.cn [School of Material, Tianjin University, Tianjin 300072 (China)] [School of Material, Tianjin University, Tianjin 300072 (China)

2014-02-07T23:59:59.000Z

392

Investigation of residual stresses induced during the selective laser melting process  

E-Print Network [OSTI]

jean-claude.boyer@insa-lyon.fr Keywords: Selective laser melting, layer additional method, Residual stresses. Abstract. The selective laser melting process (SLM), belonging to the family of additive manufacturing processes, can create complex geometry parts from a CAD file. Previously, only prototypes were

Paris-Sud XI, Université de

393

Floating hot-melt extruded tablets for gastroretentive controlled drug release system  

E-Print Network [OSTI]

a gastric floating dosage form using the puff ability at the die of a twin-screw extruder. Wei et al. [21Floating hot-melt extruded tablets for gastroretentive controlled drug release system Mamoru Fukuda bicarbonate on the physicochemical properties of controlled release hot- melt extruded (HME) tablets

Peppas, Nicholas A.

394

A continuum model of melt pond evolution on Arctic sea ice Daniela Flocco1  

E-Print Network [OSTI]

the atmosphere and ocean. In particular, sea ice affects the polar climate by insulating the ocean fromA continuum model of melt pond evolution on Arctic sea ice Daniela Flocco1 and Daniel L. Feltham1 the Northern Hemisphere summer, absorbed solar radiation melts snow and the upper surface of Arctic sea ice

Feltham, Daniel

395

Calculations of crystal-melt interfacial free energies by nonequilibrium work measurements  

E-Print Network [OSTI]

Calculations of crystal-melt interfacial free energies by nonequilibrium work measurements Yan Mu perturbation method to compute the interfacial free energies by nonequilibrium work measurements with cleaving, it is difficult to measure the crystal-melt interfacial free energy accurately and efficiently.1,2 Experimentally

Song, Xueyu

396

Trace element partitioning between baddeleyite and carbonatite melt at high pressures and high temperatures  

E-Print Network [OSTI]

as the heavy rare earth elements (HREE) prefer to enter baddeleyite rather than carbonate melts (D>1), whereas the light rare earth elements (LREE) and other trace elements behave incompatibly (D in carbonatite melts. Baddeleyite is known to accumulate the high field strength elements (HFSE) and some rare

397

Trace element partitioning between apatite and silicate melts Stefan Prowatke a,1  

E-Print Network [OSTI]

). The experiments were conducted at pressures of 1.0 GPa and temperatures of 1250 °C. The rare earth elements (La polymerisation of the melt, apatite/melt partition coefficients for the rare earth elements increase for about occurring apatites contain large amounts of the rare earth elements and Sr, it has been well known

398

Sediment Melt-Migration Dynamics in Perennial Antarctic Lake Ice Steven M. Jepsen*  

E-Print Network [OSTI]

melting through laboratory ice at 22 uC in simulated summer conditions, with warmer ice producing faster boundaries was pronounced in laboratory ice warmer than 21 uC. This mechanism produced a flux of 0.1 g m22 hrSediment Melt-Migration Dynamics in Perennial Antarctic Lake Ice Steven M. Jepsen* Edward E. Adams

Priscu, John C.

399

Thirty-year history of glacier melting in the Nepal Himalayas Koji Fujita,1  

E-Print Network [OSTI]

Thirty-year history of glacier melting in the Nepal Himalayas Koji Fujita,1 Lonnie G. Thompson,2 of glacier melting in the Nepal Himalayas, J. Geophys. Res., 111, D03109, doi:10.1029/2005JD005894. 1. Introduction [2] Rapid shrinkage of glaciers in the Nepal Himalayas has been observed during recent decades [e

Howat, Ian M.

400

Rare earth element partitioning between titanite and silicate melts: Henry's law revisited  

E-Print Network [OSTI]

Rare earth element partitioning between titanite and silicate melts: Henry's law revisited Stefan earth elements (REE) between titanite and a range of different silicate melts. Our results show. For geochemical modelling of magmatic processes involving titanite, and indeed other accessory phases

Note: This page contains sample records for the topic "melting includes graphite" 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

Exploration of coal-based pitch precursors for ultra-high thermal conductivity graphite fibers. Final report  

SciTech Connect (OSTI)

Goal was to explore the utility of coal-based pitch precursors for use in ultra high thermal conductivity carbon (graphite) fibers. From graphite electrode experience, it was established that coal-based pitches tend to form more highly crystalline graphite at lower temperatures. Since the funding was limited to year 1 effort of the 3 year program, the goal was only partially achieved. The coal-base pitches can form large domain mesophase in spite of high N and O contents. The mesophase reactivity test performed on one of the variants of coal-based pitch (DO84) showed that it was not a good candidate for carbon fiber processing. Optimization of WVU`s isotropic pitch process is required to tailor the pitch for carbon fiber processing. The hetero atoms in the coal pitch need to be reduced to improve mesophase formation.

Deshpande, G.V. [Amoco Performance Products, Inc., Alpharetta, GA (United States)

1996-12-27T23:59:59.000Z

402

Dacite Melt at the Puna Geothermal Venture Wellfield, Big Island of Hawaii  

Open Energy Info (EERE)

Dacite Melt at the Puna Geothermal Venture Wellfield, Big Island of Hawaii Dacite Melt at the Puna Geothermal Venture Wellfield, Big Island of Hawaii Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Dacite Melt at the Puna Geothermal Venture Wellfield, Big Island of Hawaii Abstract During the drilling of injection well KS-13 in 2005 at the Puna Geothermal Venture (PGV) well field, on the island of Hawaii, a 75-meter interval of diorite containing brown glass inclusions was penetrated at a depth of 2415 m. At a depth of 2488 m a melt of dacitic composition was encountered. The melt flowed up the well bore and was repeatedly re-drilled over a depth interval of 8 m, producing several kilograms of clear, colorless vitric cuttings at the surface. The dacitic glass cuttings have a perlitic texture, a silica content of 67 wgt.%, are enriched in alkalis and nearly

403

Process efficiency in polymer extrusion: Correlation between the energy demand and melt thermal stability  

Science Journals Connector (OSTI)

Abstract Thermal stability is of major importance in polymer extrusion, where product quality is dependent upon the level of melt homogeneity achieved by the extruder screw. Extrusion is an energy intensive process and optimisation of process energy usage while maintaining melt stability is necessary in order to produce good quality product at low unit cost. Optimisation of process energy usage is timely as world energy prices have increased rapidly over the last few years. In the first part of this study, a general discussion was made on the efficiency of an extruder. Then, an attempt was made to explore correlations between melt thermal stability and energy demand in polymer extrusion under different process settings and screw geometries. A commodity grade of polystyrene was extruded using a highly instrumented single screw extruder, equipped with energy consumption and melt temperature field measurement. Moreover, the melt viscosity of the experimental material was observed by using an off-line rheometer. Results showed that specific energy demand of the extruder (i.e. energy for processing of unit mass of polymer) decreased with increasing throughput whilst fluctuation in energy demand also reduced. However, the relationship between melt temperature and extruder throughput was found to be complex, with temperature varying with radial position across the melt flow. Moreover, the melt thermal stability deteriorated as throughput was increased, meaning that a greater efficiency was achieved at the detriment of melt consistency. Extruder screw design also had a significant effect on the relationship between energy consumption and melt consistency. Overall, the relationship between the process energy demand and thermal stability seemed to be negatively correlated and also it was shown to be highly complex in nature. Moreover, the level of process understanding achieved here can help to inform selection of equipment and setting of operating conditions to optimise both energy and thermal efficiencies in parallel.

Chamil Abeykoon; Adrian L. Kelly; Javier Vera-Sorroche; Elaine C. Brown; Phil D. Coates; Jing Deng; Kang Li; Eileen Harkin-Jones; Mark Price

2014-01-01T23:59:59.000Z

404

JOURNAL DE PHYSIQUE Colloque C6, supplment au n 12, Tome 37, dcembre 1976, page C6-53 MOSSBAUER STUDIES OF MOLECULES ADSORBED ON GRAPHITE (*)  

E-Print Network [OSTI]

STUDIES OF MOLECULES ADSORBED ON GRAPHITE (*) S. BUKSHPAN and T. SONNINO Soreq Nuclear Research Center obtained on Nuclear Gamma Resonance studies of molecules adsorbed on the basal plane of graphite. In all [1]. The obtained results supply information on the dynamical properties of the adsorbed molecules

Paris-Sud XI, Université de

405

Non Destructive Thermal Analysis and In Situ Investigation of Creep Mechanism of Graphite and Ceramic Composites using Phase-sensitive THz Imaging & Nonlinear Resonant Ultrasonic Spectroscopy  

SciTech Connect (OSTI)

In this project, we conducted a comprehensive study on nuclear graphite properties with terahertz (THz) imaging. Graphite samples from Idaho National Laboratory were carefully imaged by continuous wave (CW) THz. The CW THz imaging of graphite shows that the samples from different billet with different fabricating conditions have different pore size and structure. Based on this result, we then used a phase sensitive THz system to study the graphite properties. In this exploration, various graphite were studied. By imaging nuclear graphite samples in reflection mode at nine different incident polarization angles using THz timedomain- spectroscopy, we find that different domain distributions and levels of porosity will introduce polarization dependence in THz reflectivity. Sample with higher density is less porous and has a smaller average domain distribution. As a consequence, it is less polarization-dependent and the polarizationdependent frequency is higher. The results also show that samples oxidized at higher temperatures tend to be more polarization dependent. The graphite from the external billet is more polarization dependent compared to that from the center billet. In addition, we performed laser-based ultrasonic measurements on these graphite samples. The denser, unoxidized samples allow surface acoustic waves to propagate more rapidly than in the samples that had already undergone oxidation. Therefore, for the oxidized samples, the denser samples show less polarization-dependence, higher polarization-dependent frequency, and allow the surface acoustic waves propagate faster.

XI-Cheng Zhang; David Hurley; Albert Redo-sanchez

2012-11-26T23:59:59.000Z

406

SEEPAGE MODEL FOR PA INCLUDING DRIFT COLLAPSE  

SciTech Connect (OSTI)

The purpose of this report is to document the predictions and analyses performed using the seepage model for performance assessment (SMPA) for both the Topopah Spring middle nonlithophysal (Tptpmn) and lower lithophysal (Tptpll) lithostratigraphic units at Yucca Mountain, Nevada. Look-up tables of seepage flow rates into a drift (and their uncertainty) are generated by performing numerical simulations with the seepage model for many combinations of the three most important seepage-relevant parameters: the fracture permeability, the capillary-strength parameter 1/a, and the percolation flux. The percolation flux values chosen take into account flow focusing effects, which are evaluated based on a flow-focusing model. Moreover, multiple realizations of the underlying stochastic permeability field are conducted. Selected sensitivity studies are performed, including the effects of an alternative drift geometry representing a partially collapsed drift from an independent drift-degradation analysis (BSC 2004 [DIRS 166107]). The intended purpose of the seepage model is to provide results of drift-scale seepage rates under a series of parameters and scenarios in support of the Total System Performance Assessment for License Application (TSPA-LA). The SMPA is intended for the evaluation of drift-scale seepage rates under the full range of parameter values for three parameters found to be key (fracture permeability, the van Genuchten 1/a parameter, and percolation flux) and drift degradation shape scenarios in support of the TSPA-LA during the period of compliance for postclosure performance [Technical Work Plan for: Performance Assessment Unsaturated Zone (BSC 2002 [DIRS 160819], Section I-4-2-1)]. The flow-focusing model in the Topopah Spring welded (TSw) unit is intended to provide an estimate of flow focusing factors (FFFs) that (1) bridge the gap between the mountain-scale and drift-scale models, and (2) account for variability in local percolation flux due to stochastic hydrologic properties and flow processes.

C. Tsang

2004-09-22T23:59:59.000Z

407

Preparations and characterizations of novel graphite-like materials and some high oxidation state fluorine chemistry  

SciTech Connect (OSTI)

Novel graphite-like materials, BC{sub x} (6>x{ge}3), have been prepared using BCl{sub 3} and C{sub 6}H{sub 6} at 800--1000C, and C{sub x}N (14>x{ge}5) have been synthesized using C{sub 5}H{sub 5}N and Cl{sub 2} at 680C--986C. Bulk and thin film characterization were used to study the structure and bonding in these solids. C{sub 8}K(NH{sub 3}){sub 1.1} was prepared by reacting C{sub 8}K with gaseous NH{sub 3}. The carbon sub-lattice is hexagonal: a = 2.47 {Angstrom}, c = 6.47 {Angstrom}. The smaller a parameter and lower conductivity are attributed to smaller electron transfer from K to the conduction band solvation of K by NH{sub 3}. A simplified liquid phase method for synthesizing Li-graphite intercalation compounds has been developed; synthesis of a lamellar mixed conductor, C{sub x}{sup +}Li{sub 2}N{sup {minus}}, has been attempted. Stability and conductivity of (BN){sub 3}SO{sub 3}F have been studied; it was shown to be metallic with a specific conductivity of 1.5 S{center_dot}cm{sup {minus}1}. Its low conductivity is attributed to the low mobility of holes in BN sheets.

Shen, Ciping

1992-11-01T23:59:59.000Z

408

Calculated criticality for sup 235 U/graphite systems using the VIM Monte Carlo code  

SciTech Connect (OSTI)

Calculations for highly enriched uranium and graphite systems gained renewed interest recently for the new production modular high-temperature gas-cooled reactor (MHTGR). Experiments to validate the physics calculations for these systems are being prepared for the Transient Reactor Test Facility (TREAT) reactor at Argonne National Laboratory (ANL-West) and in the Compact Nuclear Power Source facility at Los Alamos National Laboratory. The continuous-energy Monte Carlo code VIM, or equivalently the MCNP code, can utilize fully detailed models of the MHTGR and serve as benchmarks for the approximate multigroup methods necessary in full reactor calculations. Validation of these codes and their associated nuclear data did not exist for highly enriched {sup 235}U/graphite systems. Experimental data, used in development of more approximate methods, dates back to the 1960s. The authors have selected two independent sets of experiments for calculation with the VIM code. The carbon-to-uranium (C/U) ratios encompass the range of 2,000, representative of the new production MHTGR, to the ratio of 10,000 in the fuel of TREAT. Calculations used the ENDF/B-V data.

Collins, P.J.; Grasseschi, G.L.; Olsen, D.N. (Argonne National Lab.-West, Idaho Falls (United States)); Finck, P.J. (Argonne National Lab., IL (United States))

1992-01-01T23:59:59.000Z

409

Melt Strength Behaviour of Polyethylenes and Polyethylene Blends and its Relation to Bubble Stability in Film Blowing  

Science Journals Connector (OSTI)

Melt strength data are presented on the three major classes of commercial polyethylenes (LDPE, LLDPE and HDPE) and some of their binary blend systems. Melt strength was assessed from uniaxial tensile experiments ...

A. Ghijsels; J. J. S. M. Ente; J. Raadsen

1988-01-01T23:59:59.000Z

410

Relationship between the residual electric resistance of solid solutions and the rate of their melting in contact with metals  

Science Journals Connector (OSTI)

The rates of melting of tin-, lead-, and indium-based binary solid solutions in contact with low-melting metals (Bi, Sn, In, Pb) have been measured. A linear relationship is established between the rate of con...

A. A. Akhkubekov; N. V. Dalakova; O. L. Enaldieva…

2006-04-01T23:59:59.000Z

411

An experimental and numerical study of surface tension-driven melt flow R.A. Parsons a,, F. Nimmo a  

E-Print Network [OSTI]

An experimental and numerical study of surface tension-driven melt flow R.A. Parsons a,, F. Nimmo 2007 Abstract To determine the role of surface tension-driven melt migration in planetary bodies, we, surface tension causes the melt to relax back to a homogeneous distribution. Samples composed of 76 vol

Nimmo, Francis

412

Observation of keyhole-mode laser melting in laser powder-bed fusion additive manufacturing  

Science Journals Connector (OSTI)

Abstract Laser powder-bed fusion additive manufacturing of metals employs high-power focused laser beams. Typically, the depth of the molten pool is controlled by conduction of heat in the underlying solid material. But, under certain conditions, the mechanism of melting can change from conduction to so-called “keyhole-mode” laser melting. In this mode, the depth of the molten pool is controlled by evaporation of the metal. Keyhole-mode laser melting results in melt pool depths that can be much deeper than observed in conduction mode. In addition, the collapse of the vapor cavity that is formed by the evaporation of the metal can result in a trail of voids in the wake of the laser beam. In this paper, the experimental observation of keyhole-mode laser melting in a laser powder-bed fusion additive manufacturing setting for 316L stainless steel is presented. The conditions required to transition from conduction controlled melting to keyhole-mode melting are identified.

Wayne E. King; Holly D. Barth; Victor M. Castillo; Gilbert F. Gallegos; John W. Gibbs; Douglas E. Hahn; Chandrika Kamath; Alexander M. Rubenchik

2014-01-01T23:59:59.000Z

413

Melt Infiltrated Ceramic Composites (Hipercomp) for Gas Turbine Engine Applications  

SciTech Connect (OSTI)

This report covers work performed under the Continuous Fiber Ceramic Composites (CFCC) program by GE Global Research and its partners from 1994 through 2005. The processing of prepreg-derived, melt infiltrated (MI) composite systems based on monofilament and multifilament tow SiC fibers is described. Extensive mechanical and environmental exposure characterizations were performed on these systems, as well as on competing Ceramic Matrix Composite (CMC) systems. Although current monofilament SiC fibers have inherent oxidative stability limitations due to their carbon surface coatings, the MI CMC system based on multifilament tow (Hi-Nicalon ) proved to have excellent mechanical, thermal and time-dependent properties. The materials database generated from the material testing was used to design turbine hot gas path components, namely the shroud and combustor liner, utilizing the CMC materials. The feasibility of using such MI CMC materials in gas turbine engines was demonstrated via combustion rig testing of turbine shrouds and combustor liners, and through field engine tests of shrouds in a 2MW engine for >1000 hours. A unique combustion test facility was also developed that allowed coupons of the CMC materials to be exposed to high-pressure, high-velocity combustion gas environments for times up to {approx}4000 hours.

Gregory Corman; Krishan Luthra

2005-09-30T23:59:59.000Z

414

Hybrid Dynamic Density Functional Theory for Polymer Melts and Blends  

E-Print Network [OSTI]

We propose a high-speed and accurate hybrid dynamic density functional theory for the computer simulations of the phase separation processes of polymer melts and blends. The proposed theory is a combination of the dynamic self-consistent field (SCF) theory and a time-dependent Ginzburg-Landau type theory with the random phase approximation (GRPA). The SCF theory is known to be accurate in evaluating the free energy of the polymer systems in both weak and strong segregation regions although it has a disadvantage of the requirement of a considerable amount of computational cost. On the other hand, the GRPA theory has an advantage of much smaller amount of required computational cost than the SCF theory while its applicability is limited to the weak segregation region. To make the accuracy of the SCF theory and the high-performance of the GRPA theory compatible, we adjust the chemical potential of the GRPA theory by using the SCF theory every constant time steps in the dynamic simulations. The performance of the GRPA and the hybrid theories is tested by using several systems composed of an A/B homopolymer, an AB diblock copolymer, or an ABC triblock copolymer. Using the hybrid theory, we succeeded in reproducing the metastable complex phase-separated domain structures of an ABC triblock copolymer observed by experiments.

Takashi Honda; Toshihiro Kawakatsu

2006-09-05T23:59:59.000Z

415

Conformational properties of blends of cyclic and linear polymer melts  

Science Journals Connector (OSTI)

An adapted version of the annealing algorithm to identify primitive paths of a melt of ring polymers is presented. This algorithm ensures that the primitive path length becomes zero for nonconcatenated rings, and that no entanglements are observed. The bond-fluctuation model was used to simulate ring-linear blends with N=150 and 300 monomers. The primitive path length and the average number of entanglements of the linear component were found to be independent of the blend composition. In contrast, the primitive path length and the average number of entanglements on a ring molecule increased approximately linearly with the fraction of linear chains, and for large N, they approached values comparable with linear chains. Threading of ring molecules by linear chains, and ring-ring interactions were observed only in the presence of linear chains. It is conjectured that for large N, these latter interactions facilitate the formation of a percolating entangled network, thereby resulting in a disproportionate retardation of the dynamical processes.

Gopinath Subramanian and Sachin Shanbhag

2008-01-14T23:59:59.000Z

416

Twofold reentrant melting in a double-Gaussian fluid  

E-Print Network [OSTI]

Isotropic pair potentials that are bounded at the origin have been proposed from time to time as models of the effective interaction between macromolecules of interest in the chemical physics of soft matter. We present a thorough study of the phase behavior of point particles interacting through a potential which combines a bounded short-range repulsion with a much weaker attraction at moderate distances, both of Gaussian shape. Notwithstanding the fact that the attraction acts as a small perturbation of the Gaussian-core model potential, the phase diagram of the double-Gaussian model (DGM) is far richer, showing two fluid phases and four distinct solid phases in the case that we have studied. Using free-energy calculations, the various regions of confluence of three distinct phases in the DGM system have all been characterized in detail. Moreover, two distinct lines of reentrant melting are found, and for each of them a rationale is provided in terms of the elastic properties of the solid phases.

S. Prestipino; C. Speranza; G. Malescio; P. V. Giaquinta

2014-03-04T23:59:59.000Z

417

Biodiesel Produced by Ethanolysis: Melting Profile, Densities, and Viscosities  

Science Journals Connector (OSTI)

Although biorenewable and sustainable ethanol is appealing and the fatty acid profiles of crambe, fodder radish, coconut, and macauba oils are proper for biodiesel production, there is little data regarding the physical properties of biodiesels produced by ethanolysis from these promising raw materials. ... Therefore, the objectives of the present work were to present the experimental densities and viscosities for biodiesels produced by ethanolysis from crambe oil (BPECr), fodder radish oil (BPEFR), coconut oil (BPEC), and macauba pulp oil (BPEMP) at temperatures up to 363.2 K, to compare the experimental data with calculated viscosities from the models proposed by Ceriani et al.(13) and Basso et al.(11) as well as with the densities calculated using the GCVOL model(14) and a systematized predictive methodology(11) based on the method proposed by Halvorsen et al.,(15) to determine, using differential scanning calorimetry, the melting profile of these four promising biofuels, and to correlate the three studied physical properties to the ethyl ester composition of each biodiesel. ... All biodiesels have low contents of polyunsaturated ethyl esters, a favorable characteristic for biodiesel because the oxidative stability decreases with increase of the unsaturation level. ...

Rodrigo C. Basso; Antônio J. A. Meirelles; Eduardo A. C. Batista

2013-09-03T23:59:59.000Z

418

Energy Saving Melting and Revert Reduction Technology: Improved Die Casting Process to Preserve the Life of the Inserts  

SciTech Connect (OSTI)

The goal of this project was to study the combined effects of die design, proper internal cooling and efficient die lubricants on die life. The project targeted improvements in die casting insert life by: Optomized Die Design for Reduced Surface Temperature: The life of die casting dies is significantly shorter when the die is exposed to elevated temperature for significant periods of time. Any die operated under conditions leading to surface temperature in excess of 1050oF undergoes structural changes that reduce its strength. Optimized die design can improve die life significantly. This improvement can be accomplished by means of cooling lines, baffles and bubblers in the die. A key objective of the project was to establish criteria for the minimal distance of the cooling lines from the surface. This effort was supported with alloys and machining by BohlerUddeholm, Dunn Steel, HH Stark and Rex Buckeye. In plant testing and evaluation was conducted as in-kind cost share at St. Clair Die Casting. The Uddeholm Dievar steel evaluated in this program showed superior resistance to thermal fatigue resistance. Based on the experimental evidence, cooling lines could be placed as close as 0.5"Âť from the surface. Die Life Extension by Optimized Die Lubrication: The life of die casting dies is affected by additions made to its surface with the proper lubricants. These lubricants will protect the surface from the considerable temperature peaks that occur when the molten melt enters the die. Dies will reach a significantly higher temperature without this lubricant being applied. The amount and type of the lubricant are critical variables in the die casting process. However, these lubricants must not corrode the die surface. This effort was supported with alloys and machining by BohlerUddeholm, Dunn Steel, HH Stark and Rex Buckeye. In plant testing and evaluation was conducted as in-kind cost share at St. Clair Die Casting. Chem- Trend participated in the program with die lubricants and technical support. Experiments conducted with these lubricants demonstrated good protection of the substrate steel. Graphite and boron nitride used as benchmarks are capable of completely eliminating soldering and washout. However, because of cost and environmental considerations these materials are not widely used in industry. The best water-based die lubricants evaluated in this program were capable of providing similar protection from soldering and washout. In addition to improved part quality and higher production rates, improving die casting processes to preserve the life of the inserts will result in energy savings and a reduction in environmental wastes. Improving die life by means of optimized cooling line placement, baffles and bubblers in the die will allow for reduced die temperatures during processing, saving energy associated with production. The utilization of optimized die lubricants will also reduce heat requirements in addition to reducing waste associated with soldering and washout. This new technology was predicted to result in an average energy savings of 1.1 trillion BTU's/year over a 10 year period. Current (2012) annual energy saving estimates, based on commercial introduction in 2010, a market penetration of 70% by 2020 is 1.26 trillion BTU's/year. Along with these energy savings, reduction of scrap and improvement in casting yield will result in a reduction of the environmental emissions associated with the melting and pouring of the metal which will be saved as a result of this technology. The average annual estimate of CO2 reduction per year through 2020 is 0.025 Million Metric Tons of Carbon Equivalent (MM TCE).

David Schwam, PI; Xuejun Zhu, Sr. Research Associate

2012-09-30T23:59:59.000Z

419

Experimental study of radium partitioning between anorthite and melt at 1 atm  

SciTech Connect (OSTI)

We present the first experimental radium mineral/melt partitioning data, specifically between anorthite and a CMAS melt at atmospheric pressure. Ion microprobe measurement of coexisting anorthite and glass phases produces a molar D{sub Ra} = 0.040 {+-} 0.006 and D{sub Ra}/D{sub Ba} = 0.23 {+-} 0.05 at 1400 C. Our results indicate that lattice strain partitioning models fit the divalent (Ca, Sr, Ba, Ra) partition coefficient data of this study well, supporting previous work on crustal melting and magma chamber dynamics that has relied on such models to approximate radium partitioning behavior in the absence of experimentally determined values.

Miller, S; Burnett, D; Asimow, P; Phinney, D; Hutcheon, I

2007-03-08T23:59:59.000Z

420

A TEM study of inverse melting in Nb{sub 45}Cr{sub 55}  

SciTech Connect (OSTI)

Inverse melting of bcc Nb{sub 45}Cr{sub 55} is investigated using transmission electron microscopy, high-resolution TEM and electron diffraction. It is shown that the transformation to the amorphous phase initiates at the bcc grain boundaries. The transformation results in an increase in incoherence, evidenced by a loss of bend contours. Some anisotropy is found in the amorphous phase produced by inverse melting, which is associated in HRTEM with preferentially oriented but discontinuous and distorted fringes. The results are consistent with the production of an amorphous phase by inverse melting.

Sinkler, W.; Michaelsen, C.; Bormann, R. [GKSS Forschungszentrum, Geesthacht (Germany). Inst. for Materials Research

1996-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "melting includes graphite" 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

Growth of SiC thin films on graphite for oxidation-protective coating J.-H. Boo,a)  

E-Print Network [OSTI]

, it is necessary to improve its resistance to oxidation. SiC is used as a semiconductor material for high of the SiC layers compared to those grown by thermal MOCVD. The mechanical and oxidation-resistant-2101 00 18204-1 I. INTRODUCTION Graphite, with its advantages of high thermal conductiv- ity, low-thermal

Boo, Jin-Hyo

422

Monash researchers led by Dr. Dan Li have developed a novel method for converting natural graphite into highly porous  

E-Print Network [OSTI]

Gel-Form Graphene Monash researchers led by Dr. Dan Li have developed a novel method for converting natural graphite into highly porous graphene film for advanced applications. Figure 1: illustrates (eg capacitors, batteries and fuel cells) n LCD displays and photovoltaic devices n Composites

Albrecht, David

423

Surface Self-Diffusion and Mean Displacement of Hydrogen on Graphite and a PEM Fuel Cell Catalyst Support  

E-Print Network [OSTI]

Surface Self-Diffusion and Mean Displacement of Hydrogen on Graphite and a PEM Fuel Cell Catalyst molecules and a carbon material commonly used in polymer electrolyte membrane fuel cells (PEMFC), called XC coefficient at each temperature. At 350 K, a typical fuel cell temperature, the temperature function

Kjelstrup, Signe

424

Determination of boron isotope ratios by Zeeman effect background correction-graphite furnace atomic absorption spectrometry  

Science Journals Connector (OSTI)

A new method for the determination of isotopic ratio of boron using Zeeman effect background correction-graphite furnace atomic absorption spectrometry with conventional atomizer and natural-boron hollow cathode source is described. The isotope-shift Zeeman effect at 208.9 nm is utilized for isotopic ratio determination. At a given concentration of total boron, the net absorbance decreases linearly with increasing 10B/11B ratio. The absorbances are recorded at the field strength of 1.0 T. The isotope ratios measured by the proposed method were in good agreement with the results obtained by inductively coupled plasma-quadruple mass spectrometry or thermal ionization mass spectrometry. The present method is fairly fast and less expensive compared to the above techniques and is quite suitable for plant environments.

S. Thangavel; S.V. Rao; K. Dash; J. Arunachalam

2006-01-01T23:59:59.000Z

425

Predicting the Voltage Dependence of Interfacial Electrochemical Processes at Lithium-Intercalated Graphite Edge Planes  

E-Print Network [OSTI]

The applied potential governs lithium-intercalation and electrode passivation reactions in lithium ion batteries, but are challenging to calibrate in condensed phase DFT calculations. In this work, the "anode potential" of charge-neutral lithium-intercalated graphite (LiC(6)) with oxidized edge planes is computed as a function of Li-content n(Li)) at edge planes, using ab initio molecular dynamics (AIMD), a previously introduced Li+ transfer free energy method, and the experimental Li+/Li(s) value as reference. The voltage assignments are corroborated using explicit electron transfer from fluoroethylene carbonate radical anion markers. PF6- is shown to decompose electrochemically (i.e., not just thermally) at low potentials imposed by our voltage calibration technique. We demonstrate that excess electrons reside in localized states-in-the-gap in the organic carbonate liquid region, which is not semiconductor-like (band-state-like) as widely assumed in the literature.

Leung, Kevin

2015-01-01T23:59:59.000Z

426

Proceedings of the conference on electrochemistry of carbon allotropes: Graphite, fullerenes and diamond  

SciTech Connect (OSTI)

This conference provided an opportunity for electrochemists, physicists, materials scientists and engineers to meet and exchange information on different carbon allotropes. The presentations and discussion among the participants provided a forum to develop recommendations on research and development which are relevant to the electrochemistry of carbon allotropes. The following topics which are relevant to the electrochemistry of carbon allotropes were addressed: Graphitized and disordered carbons, as Li-ion intercalation anodes for high-energy-density, high-power-density Li-based secondary batteries; Carbons as substrate materials for catalysis and electrocatalysis; Boron-doped diamond film electrodes; and Electrochemical characterization and electrosynthesis of fullerenes and fullerene-type materials. Abstracts of the presentations are presented.

Kinoshita, K. [ed.] [Lawrence Berkeley National Lab., CA (United States); Scherson, D. [ed.] [Case Western Reserve Univ., Cleveland, OH (United States)

1998-02-01T23:59:59.000Z

427

Coating formulation and method for refinishing the surface of surface-damaged graphite articles  

DOE Patents [OSTI]

The described development is directed to a coating formulation for filling surface irregularities in graphite articles such as molds, crucibles, and matched die sets used in high-temperature metallurgical operations. The coating formulation of the present invention is formed of carbon black flour, thermosetting resin and a solvent for the resin. In affixing the coating to the article, the solvent is evaporated, the resin cured to bond the coating to the surface of the article and then pyrolyzed to convert the resin to carbon. Upon completion of the pyrolysis step, the coating is shaped and polished to provide the article with a surface restoration that is essentially similar to the original or desired surface finish without the irregularity.

Ardary, Z.L.; Benton, S.T.

1987-07-08T23:59:59.000Z

428

Hydrogen-induced magnetization and tunable hydrogen storage in graphitic structures  

Science Journals Connector (OSTI)

Hydrogen interactions with undefective and defective graphitic structures were investigated by first-principles simulations. Structural vacancies were identified to promote the dissociation of molecular hydrogen with a reduced activation barrier of 0.63eV, compared to 2.38eV for a perfect graphene. However, the vacancies bind the hydrogen too strongly for spill-over mechanisms to be effective. An isolated vacancy in a graphene can bind four hydrogen atoms, but a metastable and magnetic structure binds six hydrogen atoms at the vacancy site at room temperature. The thermodynamics, magnetic properties, and hydrogen binding energies vary with graphene layer spacing. A metastable structure becomes energetically favorable for a layer spacing of 3.19Ĺ, while the binding of hydrogen becomes exothermic at a layer spacing of 2.72Ĺ. This phenomenon suggests the possibility of using hydrogen-rich carbon structures for reversible magnetic and hydrogen storage applications.

Yang Lei; Stephen A. Shevlin; Wenguang Zhu; Zheng Xiao Guo

2008-04-24T23:59:59.000Z

429

Synthesis of few layer graphene by direct exfoliation of graphite and a Raman spectroscopic study  

SciTech Connect (OSTI)

The exfoliation of graphene from pristine graphite in a liquid phase was achieved successfully via sonication followed by centrifugation method. Ultraviolet–visible (UV–vis) spectra of the obtained graphene dispersions at different exfoliation time indicated that the concentration of graphene dispersion increased markedly with increasing exfoliation time. The sheet-like morphology of the exfoliated graphene was revealed by Scanning Electron Microscopy (SEM) image. Further, the morphological change in different exfoliation time was investigated by Atomic Force Microscopy (AFM). A complete structural and defect characterization was probed using micro-Raman spectroscopic technique. The shape and position of the 2D band of Raman spectra revealed the formation of bilayer to few layer graphene. Also, Raman mapping confirmed the presence of uniformly distributed bilayer graphene sheets on the substrate.

Gayathri, S.; Jayabal, P.; Ramakrishnan, V., E-mail: vr.optics1@gmail.com [Department of Laser Studies, School of Physics, Madurai Kamaraj University, Madurai-625021, India. (India); Kottaisamy, M. [Department of Chemistry, Thiagarajar College of Engineering, Madurai-625015, India. (India)] [Department of Chemistry, Thiagarajar College of Engineering, Madurai-625015, India. (India)

2014-02-15T23:59:59.000Z

430

Origin of melt-texture crystal growth process in a simple tube furnace  

SciTech Connect (OSTI)

The melt-texture growth (MTG) method has been shown to be effective in fabricating high-T[sub c] superconducting bulk samples with highly oriented layers of single crystals. The critical current density J[sub c] of the typical samples are enhanced significantly. Furthermore, making use of the nonzero spatial temperature gradient at certain locations of a common tube furance, we fabricated Y-123 bulk samples with various dopants allowing J[sub c] up to [approx equal] 3.0 [times] 10[sup 4] A cm[sup [minus]2] in our recent investigations. We followed up our project by analyzing the relations among the crucial parameters involved in the modified version of the MTG process. These parameters include the temperature gradient, the time rate of change of temperature, the [open quotes]growth front[close quotes] of the crystal, etc. Our study indicates that some of the empty space regions that appear between layers are only shallow [open quotes]gap lines[close quotes]. True layers of single crystals do exist, and we present an explanation for the growth of crystal layers along special directions as observed. 26 refs., 6 figs.

Fung, P.C.W.; Chow, J.C.L.; Yu, T.F. (Univ. of Hong Kong (Hong Kong)); Du, Z.L. (Zhongshan Univ. (China))

1993-08-01T23:59:59.000Z

431

Charge Melting & Polaron Collapse in LA1.2SR1.8MN207  

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

Charge Melting & Polaron Collapse in LA1.2SR1.8MN207 Charge Melting & Polaron Collapse in LA1.2SR1.8MN207 Recent studies carried out on the Synchrotron Radiation Instrumentation Collaborative Access Team's beamline I-ID-C at the Advanced Photon Source provide new insights into charge melting and polaron collapse. X-ray and neutron scattering measurements directly demonstrate the existence of polarons in the paramagnetic phase of optimally doped colossal magnetoresistive oxides. The polarons exhibit short-range correlations that grow with decreasing temperature, but disappear abruptly at the ferromagnetic transition because of the sudden charge delocalization. The "melting" of the charge ordering as we cool through TC occurs with the collapse of the quasistatic polaron scattering, and provides important new

432

Geek-Up: K East Reactor Demolition, Retrograde Melting and Cloud Pattern  

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

Up: K East Reactor Demolition, Retrograde Melting and Cloud Up: K East Reactor Demolition, Retrograde Melting and Cloud Pattern Tracking Geek-Up: K East Reactor Demolition, Retrograde Melting and Cloud Pattern Tracking August 13, 2010 - 6:32pm Addthis Elizabeth Meckes Elizabeth Meckes Director of User Experience & Digital Technologies, Office of Public Affairs The Energy Department's Hanford Site in Washington used Recovery Act funds to safely take down the K East Reactor's 175-foot-high exhaust stack near the Columbia River. The demolition was a crucial step toward dismantling the external footprint of the reactor and clears the way for additional work to clean up the area. Watch footage of the blast above or find more information at http://www.hanford.gov Normally, we think of things melting (or changing from a solid to a liquid)

433

Melt zones beneath five volcanic complexes in California: an assessment of  

Open Energy Info (EERE)

Melt zones beneath five volcanic complexes in California: an assessment of Melt zones beneath five volcanic complexes in California: an assessment of shallow magma occurrences Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Report: Melt zones beneath five volcanic complexes in California: an assessment of shallow magma occurrences Details Activities (5) Areas (5) Regions (0) Abstract: Recent geological and geophysical data for five magma-hydrothermal systems were studied for the purpose of developing estimates for the depth, volume and location of magma beneath each area. The areas studied were: (1) Salton Trough, (2) The Geysers-Clear Lake, (3) Long Valley caldera, (4) Coso volcanic field, and (5) Medicine Lake volcano, all located in California and all selected on the basis of recent volcanic activity and published indications of crustal melt zones. 23 figs.

434

Access to glacial and subglacial environments in the Solar System by melting probe technology  

Science Journals Connector (OSTI)

The use of power intensive devices such as ice-melting probes in the outer Solar System strongly points to radioactive units for ... traditional space application RHU (Radioactive Heater Unit) technology is based...

Stephan Ulamec; Jens Biele; Oliver Funke…

2007-08-01T23:59:59.000Z

435

Biological and Chemical Scrubbings of Vented gas from hot-melting operation of recycled nylon plastics.  

E-Print Network [OSTI]

??This study aimed to develop a biotrickling-biofilter process and a two-stage chemical scrubbing process to absorb and oxidize VOCs in vented gas from hot-melt granulation… (more)

Chen, Kuan-po

2014-01-01T23:59:59.000Z

436

An Experimental Study of Melting of Binary Mixtures with Double-Diffusive Convection in  

E-Print Network [OSTI]

of a vertical ice surface into a salinity gradient inside an enclosure. Because of its lower salinity, the melt of ice in saline water [8-11]. Depending on the temperature and salinity of the ambient water, a number

Beckermann, Christoph

437

Melt Rheology and Thermal Stability of Nanoclay Filled Poly(3hydroxybutyrate-co-4hydroxybutyrate) Biocomposites  

Science Journals Connector (OSTI)

Melt apparent shear viscosity for poly(3hydroxybutyrate-co-4hydroxybutyrate) composites filled with nanoclay was measured by means of a capillary...?1..., and thermal stability was conducted on a thermogravimetri...

Jia Yang; Lina Hang; Yahui Dai

2014-09-01T23:59:59.000Z

438

Melt blend studies of nanoclay-filled polypropylene (PP)–high-density polyethylene (HDPE) composites  

Science Journals Connector (OSTI)

The objective of this work is to study how the rheological factors of unfilled and nanoclay-filled HDPE–PP blend series influence the ... 100 wt % HDPE), with and without nanoclay, was prepared by using melt-mixi...

T. P. Mohan; K. Kanny

2013-12-01T23:59:59.000Z

439

High Strain-Rate Response of High Purity Aluminum at Temperatures Approaching Melt  

SciTech Connect (OSTI)

High-temperature, pressure-shear plate impact experiments were conducted to investigate the rate-controlling mechanisms of the plastic response of high-purity aluminum at high strain rates (10{sup 6} s{sup -1}) and at temperatures approaching melt. Since the melting temperature of aluminum is pressure dependent, and a typical pressure-shear plate impact experiment subjects the sample to large pressures (2 GPa-7 GPa), a pressure-release type experiment was used to reduce the pressure in order to measure the shearing resistance at temperatures up to 95% of the current melting temperature. The measured shearing resistance was remarkably large (50 MPa at a shear strain of 2.5) for temperatures this near melt. Numerical simulations conducted using a version of the Nemat-Nasser/Isaacs constitutive equation, modified to model the mechanism of geometric softening, appear to capture adequately the hardening/softening behavior observed experimentally.

Grunschel, S E; Clifton, R J; Jiao, T

2010-01-28T23:59:59.000Z

440

Kinetic coefficient for hard-sphere crystal growth from the melt  

E-Print Network [OSTI]

Using molecular-dynamics simulation, we determine the magnitude and anisotropy of the kinetic coefficient (mu) for the crystal growth from the melt for the hard-sphere system through an analysis of equilibrium capillary ...

Laird, Brian Bostian; Amini, M.

2006-11-24T23:59:59.000Z

Note: This page contains sample records for the topic "melting includes graphite" 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

Boron isotopic variations in hydrous rhyolitic melts: a case study from Long Valley, California  

Science Journals Connector (OSTI)

In this paper, we present boron isotope analyses of variably degassed rhyolitic glasses from Long Valley, California. The following results indicate that...2O-rich (~3 wt%) melt inclusions from late erupted Bisho...

A. K. Schmitt; J. I. Simon

2004-01-01T23:59:59.000Z

442

Optimization method for obtaining nearest-neighbour DNA entropies and enthalpies directly from melting temperatures  

Science Journals Connector (OSTI)

......require the knowledge of total sequence entropies and enthalpies which are not always available. Results: Here we implement and test a new melting temperature optimization method (MTO) where we obtain the NN parameters directly from the temperatures. In this......

Gerald Weber

2014-11-01T23:59:59.000Z

443

Examination of offsite radiological emergency protective measures for nuclear reactor accidents involving core melt  

E-Print Network [OSTI]

Evacuation, sheltering followed by population relocation, and iodine prophylaxis are evaluated as offsite public protective measures in response to nuclear reactor accidents involving core-melt. Evaluations were conducted ...

Aldrich, David C.

1979-01-01T23:59:59.000Z

444

Theoretical description of laser melt pool dynamics, Task order number B239634, Quarter 3 report  

SciTech Connect (OSTI)

Melting of solid matter under laser radiation is realized in almost every process of laser technology. The present paper addresses melted material flows in cases when melt zones are shallow, i.e., the zone width is appreciably greater than or of the same order as its depth. Such conditions are usually realized when hardening, doping or perforating thin plates or when using none-deep penetration. Melted material flowing under conditions of deep penetration, drilling of deep openings and cutting depends on a number of additional factors (as compared to the shallow-pool case), namely, formation of a vapor and gas cavern in the sample and propagation of the laser beam through the cavern. These extra circumstances complicate hydrodynamic consideration of the liquid bath and will be addressed is the paper to follow.

Dykhne, A.

1995-05-10T23:59:59.000Z

445

The origin of melt-texture crystal growth process in a simple tube furnace  

Science Journals Connector (OSTI)

The melt-texture growth (MTG) method has been shown to be effective...T csuperconducting bulk samples with highly oriented layers of single crystals. The critical current densityJ

P. C. W. Fung; J. C. L. Chow; T. F. Yu; Z. L. Du

1993-08-01T23:59:59.000Z

446

Seismic and gravitational studies of melting in the mantle's thermal boundary layers  

E-Print Network [OSTI]

This thesis presents three studies which apply geophysical tools to the task of better understanding mantle melting phenomena at the upper and lower boundaries of the mantle. The first study uses seafloor bathymetry and ...

Van Ark, Emily M

2007-01-01T23:59:59.000Z

447

Controlling electrode gap during vacuum arc remelting at low melting current  

DOE Patents [OSTI]

An apparatus and method are disclosed for controlling electrode gap in a vacuum arc remelting furnace, particularly at low melting currents. Spectrographic analysis is performed of the metal vapor plasma, from which estimates of electrode gap are derived. 5 figs.

Williamson, R.L.; Zanner, F.J.; Grose, S.M.

1997-04-15T23:59:59.000Z

448

CATALYTIC LIQUEFACTION BY ZINC CHLORIDE MELTS AT PRE-PYROLYSIS TEMPERATURE  

E-Print Network [OSTI]

3% Zn and 14% CH oH (50 g coal 9 300 g melt) Atomic TempVermeulen, "High-Yield Coal Conversion in a Zinc Chloride/H. Shinn, and T. Vermeulen, "Coal Lic;uefaction Catalysis by

Vermeulen, T.

2012-01-01T23:59:59.000Z

449

E-Print Network 3.0 - alkaline melts beneath Sample Search Results  

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

et al. 2001), mac alkaline magmas... , it is not coincident that the mac rock at Bingham Canyon is alkaline (Waite et al. 1997) and the basaltic mac melt... specia- tion...

450

Crystal structure and interaction dependence of the crystal-melt interfacial free energy  

E-Print Network [OSTI]

We examine via molecular simulation the dependence of the crystal-melt interfacial free energy gamma on molecular interaction and crystal structure (fcc vs bcc) for systems interacting with inverse-power repulsive potentials, ...

Davidchack, R. L.; Laird, Brian Bostian

2005-03-01T23:59:59.000Z

451

Vacuum-induction melting, refining, and casting of uranium and its alloys  

SciTech Connect (OSTI)

The vacuum-induction melting (VIM), refining, and casting of uranium and its alloys are discussed. Emphasis is placed on historical development, VIM equipment, crucible and mold design, furnace atmospheres, melting parameters, impurity pickup, ingot quality, and economics. The VIM procedures used to produce high-purity, high-quality sound ingots at the US Department of Energy Rocky Flats Plant are discussed in detail.

Jackson, R.J.

1989-10-11T23:59:59.000Z

452

NREL Scientists Reveal Origin of Diverse Melting Behaviors of Aluminum Nanoclusters (Fact Sheet)  

SciTech Connect (OSTI)

Research reveals active role of cluster symmetries on the size-sensitive, diverse melting behaviors of metallic nanoclusters, providing insight to understanding phase changes of nanoparticles for thermal energy storage. Unlike macroscopic bulk materials, intermediate-sized nanoclusters with around 55 atoms inherently exhibit size-sensitive melting changes: adding just a single atom to a nanocluster can cause a dramatic change in melting behavior. Microscopic understanding of thermal behaviors of metal nanoclusters is important for nanoscale catalysis and thermal energy storage applications. However, it is a challenge to obtain a structural interpretation at the atomic level from measured thermodynamic quantities such as heat capacity. Using ab initio molecular dynamics simulations, scientists at the National Renewable Energy Laboratory (NREL) revealed a clear correlation between the diverse melting behaviors of aluminum nanoclusters and cluster core symmetries. These simulations reproduced, for the first time, the size-sensitive heat capacities of aluminum nanoclusters, which exhibit several distinctive shapes associated with the diverse melting behaviors of the clusters. The size-dependent, diverse melting behaviors of the aluminum clusters are attributed to the reduced symmetry (from Td {yields} D2d {yields} Cs) with increasing the cluster sizes and can be used to help design thermal storage materials.

Not Available

2011-10-01T23:59:59.000Z

453

Theory of melt fracture instabilities in the capillary flow of polymer melts Joel D. Shore,1,* David Ronis,1,2  

E-Print Network [OSTI]

occur when a poly- mer melt is extruded through a capillary or ``die'' is a longstanding problem pressure, respectively. The inset in Fig. 1 is a cartoon of a typical experimental setup: a piston or screw regimes 2,3,6 : At the lowest flow rates, the extrudate is smooth and regular. Next, one encounters a re

Grant, Martin

454

Graphene-based electrochemical sensor for detection of 2,4,6-trinitrotoluene (TNT) in seawater: the comparison of single-, few-, and multilayer graphene nanoribbons and graphite microparticles  

Science Journals Connector (OSTI)

The detection of explosives in seawater is of great interest. We compared response single-, few-, and multilayer graphene nanoribbons and graphite microparticle-based electrodes toward ... and pH. We found that f...

Madeline Shuhua Goh; Martin Pumera

2011-01-01T23:59:59.000Z

455

Graphite-moderated, gas-cooled, and water-moderated, water-cooled reactors as power units in nuclearelectric power stations  

Science Journals Connector (OSTI)

The present article reviews a number of papers submitted at the Second International Conference on the Peaceful Uses of Atomic Energy bearing on water-cooled, water-moderated, graphite-moderated, and gas-coole...

Yu. I. Koryakin

1960-11-01T23:59:59.000Z

456

Restoration of the graphite memory of a reactor in the third power-generating unit of the Leningrad nuclear power plant  

Science Journals Connector (OSTI)

The restoration of the graphite masonry of cell 52-16 in the reactor in the third power-generating unit of the Leningrad nuclear power plant is described. The process reduces to moving...

V. I. Lebedev; Yu. V. Garusov; M. A. Pavlov; A. N. Peunov; E. P. Kozlov

1999-11-01T23:59:59.000Z

457

Electrochemical cell studies on fluorinated natural graphite in propylene carbonate electrolyte with difluoromethyl acetate (MFA) additive for low temperature lithium battery application  

Science Journals Connector (OSTI)

Electrochemical cell performances of fluorinated natural graphite (abbreviated as FNG) electrode material was studied by using 1M of LiClO4? EC: DEC: PC (1: 1: 1 v%) electrolyte solution with and without 0·15% v/...

R. Chandrasekaran; M. Koh; Y. Ozhawa; H. Aoyoma…

2009-05-01T23:59:59.000Z

458

Measurement of the Young's modulus and internal friction of single crystal and polycrystalline copper, and copper-graphite composites as a function of temperature and orientation  

E-Print Network [OSTI]

MEASUREMENT OF THE YOUNG'S MODULUS AND INTERNAL FRICTION OF SINGLE CRYSTAL AND POLYCRYSTALLINE COPPER, AND COPPER- GRAPHITE COMPOSITES AS A FUNCTION OF TEMPERATURE AND ORIENTATION A Thesis by S teven Norman Wicks trom Submitted... AND POLYCRYSTALLINE COPPER, AND COPPER- GRAPHITE COMPOSITES AS A FUNCTION OF TEMPERATURE AND ORIENTATION A Thesis by Steven Norman Wickstrom Approved as to style and content by: A(J ~a Alan Wolfenden (Chairman of Committee) Don E. Bray (Member) Donald G...

Wickstrom, Steven Norman

2012-06-07T23:59:59.000Z

459

Differentiating the role of lithium and oxygen in retaining deuterium on lithiated graphite plasma-facing components  

SciTech Connect (OSTI)

Laboratory experiments have been used to investigate the fundamental interactions responsible for deuterium retention in lithiated graphite. Oxygen was found to be present and play a key role in experiments that simulated NSTX lithium conditioning, where the atomic surface concentration can increase to >40% when deuterium retention chemistry is observed. Quantum-classical molecular dynamic simulations elucidated this oxygen-deuterium effect and showed that oxygen retains significantly more deuterium than lithium in a simulated matrix with 20% lithium, 20% oxygen, and 60% carbon. Simulations further show that deuterium retention is even higher when lithium is removed from the matrix. Experiments artificially increased the oxygen content in graphite to ?16% and then bombarded with deuterium. X-ray photoelectron spectroscopy showed depletion of the oxygen and no enhanced deuterium retention, thus demonstrating that lithium is essential in retaining the oxygen that thereby retains deuterium.

Taylor, C. N. [Fusion Safety Program, Idaho National Laboratory, P.O. Box 1625-7113, Idaho Falls, Idaho 83415 (United States) [Fusion Safety Program, Idaho National Laboratory, P.O. Box 1625-7113, Idaho Falls, Idaho 83415 (United States); School of Nuclear Engineering, Purdue University, 400 Central Drive, West Lafayette, Indiana 47907 (United States); Allain, J. P. [School of Nuclear Engineering, Purdue University, 400 Central Drive, West Lafayette, Indiana 47907 (United States) [School of Nuclear Engineering, Purdue University, 400 Central Drive, West Lafayette, Indiana 47907 (United States); Department of Nuclear, Plasma and Radiological Engineering, University of Illinois at Urbana-Champaign, Illinois 61801 (United States); Luitjohan, K. E. [School of Nuclear Engineering, Purdue University, 400 Central Drive, West Lafayette, Indiana 47907 (United States)] [School of Nuclear Engineering, Purdue University, 400 Central Drive, West Lafayette, Indiana 47907 (United States); Krstic, P. S. [Institute for Advanced Computational Science, Stony Brook University, New York 11794 (United States) [Institute for Advanced Computational Science, Stony Brook University, New York 11794 (United States); Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996 (United States); TheoretiK, Knoxville, Tennessee 379XX (United States); Dadras, J. [Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996 (United States) [Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996 (United States); Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California 90095 (United States); Skinner, C. H. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)] [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

2014-05-15T23:59:59.000Z

460

Functionalization/passivation of porous graphitic carbon with di-tert-amylperoxide  

SciTech Connect (OSTI)

Porous graphitic carbon (PGC) particles were functionalized/passivated in situ in packed beds at elevated temperature with neat di-tert-amylperoxide (DTAP) in a column oven. The performance of these particles for high performance liquid chromatography (HPLC) was assayed before and after this chemistry with the following analytes: benzene, toluene, ethyl benzene, n-propyl benzene, n-butyl benzene, p-xylene, phenol, 4-methylphenol, phenetole, 3,5-xylenol, and anisole. After the first functionalization/passivation, the retention factors, k, of these compounds decreased by about 5% and the number of theoretical plates (N) increased by ca. 15%. These values of k then remained roughly constant after a second functionalization/ passivation but a further increase in N was noticed. In addition, after each of the reactions, the peak asymmetries decreased by ca. 15%, for a total of ca. 30%. The columns were then subjected twice to methanol at 100 C for 5 h at 1 mL/min. After these stability tests, the values of k remained roughly constant, the number of plates increased, which is favorable, and the asymmetries rose and then declined, where they remained below the initial values for the unfunctionalized columns. Functionalized and unfunctionalized particles were characterized by scanning electron microscopy and BET measurements, which showed no difference between the functionalized and unfunctionalized materials, and X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry (ToF-SIMS), where ToF-SIMS suggested some chemical differences between the functionalized and unfunctionalized materials. In particular ToF-SIMS suggested that the expected five-carbon fragments from DTAP exist at higher concentrations on DTAP-functionalized PGC. First principle calculations on model graphitic surfaces suggest that the first addition of a DTAP radical to the surface proceeds in an approximately isothermal or slightly favorable fashion, but that subsequent DTAP additions are then increasingly thermodynamically favorable. Thus, this analysis suggests that the direct functionalization/passivation of PGC with DTAP is plausible. Chemometric analyses of the chromatographic and ToF-SIMS data are also presented.

Jensen, David S.; Gupta, Vipul; Olsen, Rebecca E.; Miller, Alex T.; Davis, Robert C.; Ess, Daniel; Zhu, Zihua; Vail, Michael A.; Dadson, Andrew; Linford, Matthew R.

2011-11-18T23:59:59.000Z

Note: This page contains sample records for the topic "melting includes graphite" 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

Final Report: Use of Graphite Foam as a Thermal Performance Enhancement of Heavy Hybrid Propulsion Systems  

SciTech Connect (OSTI)

Oak Ridge National Laboratory's graphite foam has the potential to be used as a heat exchanger for the Army's Future Combat System Manned Ground Vehicle and thus has the potential to improve its thermal performance. The computational fluid dynamics (CFD) program FLOW3D was used to develop a new CFD model for the graphite foam to be used in the development of a proper heat exchanger. The program was calibrated by first measuring the properties of the solid foams and determining the parameters to be used in the CFD model. Then the model was used to predict within 5% error the performance of finned foam heat sinks. In addition, the f factors and j factors commonly used to predict pressure drop and heat transfer were calculated for both the solid and finned structures. There was some evidence that corrugating the foams would yield higher j/f ratios than state of the art heat exchangers, confirming previously measured data. Because the results show that the CFD model was validated, it is recommended that the funding for Phases 2 through 5 be approved for the design of both the finned heat exchanger using tubes and round fin structures and the solid foam design using corrugated foams. It was found that the new CFD model using FLOW3D can predict both solid foam heat transfer and finned foam heat transfer with the validated model parameters. In addition, it was found that the finned foam structures exhibited j/f ratios that indicate that significant heat transfer is occurring within the fin structures due to aerodynamically induced flow, which is not present in solid aluminum fin structures. It is possible that the foam surfaces can act as turbulators that increase heat transfer without affecting pressure drop, like the vortex generators seen in state of the art heat exchangers. These numbers indicate that the foam can be engineered into an excellent heat exchanger. It was also found that corrugating the solid foams would increase the j/f ratio dramatically, allowing the solid foams to compete directly with standard heat exchangers. Although corrugated L1 foam samples have not been produced (attempts are under way), it is possible that their j/f ratio can be even higher than those of the finned structures.

Klett, James William [ORNL; Conklin, Jim [ORNL

2011-06-01T23:59:59.000Z

462

Comparative NEXAFS Study on Soot Obtained from an Ethylene/Air Flame, a Diesel Engine, and Graphite  

Science Journals Connector (OSTI)

Comparative NEXAFS Study on Soot Obtained from an Ethylene/Air Flame, a Diesel Engine, and Graphite ... Aerosol and Nanostructures Laboratory, Istituto Motori, CNR, Napoli, Italy, and Department of Chemical and Materials Engineering and Consortium for Fossil Fuel Science, University of Kentucky, Lexington, Kentucky 40515 ... Microstructure and molecular structure properties of different carbonaceous byproducts from combustion are fundamental to evaluate the radiative properties of such materials when combustion aerosols interact with solar radiation in atmosphere. ...

Stefano di Stasio; Artur Braun

2005-11-15T23:59:59.000Z

463

Organic free radicals and micropores in solid graphitic carbonaceous matter at the Oklo natural fission reactors, Gabon  

SciTech Connect (OSTI)

The presence, concentration, and distribution of organic free radicals as well as their association with specific surface areas and microporosities help characterize the evolution and behavior of the Oklo carbonaceous matter. Such information is necessary in order to evaluate uranium mineralization, liquid bitumen solidification, and radio nuclide containment at Oklo. In the Oklo ore deposits and natural fission reactors carbonaceous matter is often referred to as solid graphitic bitumen. The carbonaceous parts of the natural reactors may contain as much as 65.9% organic C by weight in heterogeneous distribution within the clay-rich matrix. The solid carbonaceous matter immobilized small uraninite crystals and some fission products enclosed in this uraninite and thereby facilitated radio nuclide containment in the reactors. Hence, the Oklo natural fission reactors are currently the subjects of detailed studies because they may be useful analogues to support performance assessment of radio nuclide containment at anthropogenic radioactive waste repository sites. Seven carbonaceous matter rich samples from the 1968 {+-} 50 Ma old natural fission reactors and the associated Oklo uranium ore deposit were studied by electron spin resonance (ESR) spectroscopy and by measurements of specific surface areas (BET method). Humic acid, fulvic acid, and fully crystalline graphite standards were also examined by ESR spectroscopy for comparison with the Oklo solid graphitic bitumens. With one exception, the ancient Oklo bitumens have higher organic free radical concentrations than the modem humic and fulvic acid samples. The presence of carbon free radicals in the graphite standard could not be determined due to the conductivity of this material. 72 refs., 7 figs., 1 tab.

Rigali, M.J.; Nagy, B. [Univ. of Arizona, Tucson, AZ (United States)] [Univ. of Arizona, Tucson, AZ (United States)

1997-01-01T23:59:59.000Z

464

Microsoft PowerPoint - srnl_24x36vert Nov2010 EM tech exchange melt rate model choi.ppt  

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

Enhancement of DWPF Melt Rate Model (WP 4.2.3) Enhancement of DWPF Melt Rate Model (WP 4.2.3) A.S. Choi, D. H. Miller, Engineering Process Development D. M. Immel, Imaging and Radiation Systems Free energy output is re-arranged into various functional groups based on literature data on aluminoborosilicate glass structural units Methodology: Objective: Develop a predictive tool for the impact of feed chemistry on relative melt rate of HLW glasses. Input Semi-empirical 4-Stage DWPF Cold Cap Model Output Phase Equilibria & Speciation of Melt, Intermediate Condensed Phases, Calcine Gases and Their Free Energies Feed Chemistry NIST Free Energy Database for Complex Liquids Melt Rate Furnace (MRF) Experiments Derive an empirical correlation of relative melt rates using free energy functional groups. X-Ray Imaging &

465

Experimental Study of the Effect of Graphite Dispersion on the Heat Transfer Phenomena in a Reactor Cavity Cooling System  

SciTech Connect (OSTI)

An experimental activity was performed to observe and study the effects of graphite dispersion and deposition on thermal-hydraulic phenomena in a reactor cavity cooling system (RCCS). The small-scale RCCS experimental facility (16.5 x 16.5 x 30.4 cm) used for this activity represents half of the reactor cavity with an electrically heated vessel. Water flowing through five vertical pipes removes the heat produced in the vessel and releases it into the environment by mixing with cold water in a large tank. The particle image velocimetry technique was used to study the velocity field of the air inside the cavity. A set of 52 thermocouples was installed in the facility to monitor the temperature profiles of the vessel, pipe walls, and air. Ten grams of a fine graphite powder (average particle size 2 m) was injected into the cavity through a spraying nozzle placed at the bottom of the vessel. The temperatures and air velocity field were recorded and compared with the measurements obtained before the graphite dispersion, showing a decrease of the temperature surfaces that was related to an increase in their emissivity. The results contribute to the understanding of RCCS capability in an accident scenario.

Rodolfo Vaghetto; Luigi Capone; Yassin A. Hassan

2011-05-31T23:59:59.000Z

466

Melting temperatures of the ZrO{sub 2}-MOX system  

SciTech Connect (OSTI)

Severe accidents occurred at the Fukushima Daiichi Nuclear Power Plant Units 1-3 on March 11, 2011. MOX fuels were loaded in the Unit 3. For the thermal analysis of the severe accident, melting temperature and phase state of MOX corium were investigated. The simulated coriums were prepared from 4%Pu-containing MOX, 8%Pu-containing MOX and ZrO{sub 2}. Then X-ray diffraction, density and melting temperature measurements were carried out as a function of zirconium and plutonium contents. The cubic phase was observed in the 25%Zr-containing corium and the tetragonal phase was observed in the 50% and 75%Zr-containing coria. The lattice parameter and density monotonically changed with Pu content. Melting temperature increased with increasing Pu content; melting temperature were estimated to be 2932 K for 4%Pu MOX corium and 3012 K for 8%Pu MOX corium in the 25%ZrO{sub 2}-MOX system. The lowest melting temperature was observed for 50%Zr-containing corium. (authors)

Uchida, T.; Hirooka, S.; Kato, M.; Morimoto, K. [Japan Atomic Energy Agency, 4-33, Muramatsu, Tokai-mura, Naka-gun, Ibaraki 319-1194 (Japan); Sugata, H.; Shibata, K.; Sato, D. [Inspection Development Company, 4-33, Muramatsu, Tokai-mura, Naka-gun, Ibaraki 319-1194 (Japan)

2013-07-01T23:59:59.000Z

467

Fundamentals of Melt-Water Interfacial Transport Phenomena: Improved Understanding for Innovative Safety Technologies in ALWRs  

SciTech Connect (OSTI)

The interaction and mixing of high-temperature melt and water is the important technical issue in the safety assessment of water-cooled reactors to achieve ultimate core coolability. For specific advanced light water reactor (ALWR) designs, deliberate mixing of the core-melt and water is being considered as a mitigative measure, to assure ex-vessel core coolability. The goal of this work is to provide the fundamental understanding needed for melt-water interfacial transport phenomena, thus enabling the development of innovative safety technologies for advanced LWRs that will assure ex-vessel core coolability. The work considers the ex-vessel coolability phenomena in two stages. The first stage is the melt quenching process and is being addressed by Argonne National Lab and University of Wisconsin in modified test facilities. Given a quenched melt in the form of solidified debris, the second stage is to characterize the long-term debris cooling process and is being addressed by Korean Maritime University in via test and analyses. We then address the appropriate scaling and design methodologies for reactor applications.

M. Anderson; M. Corradini; K.Y. Bank; R. Bonazza; D. Cho

2005-04-26T23:59:59.000Z

468

Models for mean bonding length, melting point and lattice thermal expansion of nanoparticle materials  

SciTech Connect (OSTI)

Graphical abstract: Three models are derived to explain the nanoparticles size dependence of mean bonding length, melting temperature and lattice thermal expansion applied on Sn, Si and Au. The following figures are shown as an example for Sn nanoparticles indicates hilly applicable models for nanoparticles radius larger than 3 nm. Highlights: ? A model for a size dependent mean bonding length is derived. ? The size dependent melting point of nanoparticles is modified. ? The bulk model for lattice thermal expansion is successfully used on nanoparticles. -- Abstract: A model, based on the ratio number of surface atoms to that of its internal, is derived to calculate the size dependence of lattice volume of nanoscaled materials. The model is applied to Si, Sn and Au nanoparticles. For Si, that the lattice volume is increases from 20 ?{sup 3} for bulk to 57 ?{sup 3} for a 2 nm size nanocrystals. A model, for calculating melting point of nanoscaled materials, is modified by considering the effect of lattice volume. A good approach of calculating size-dependent melting point begins from the bulk state down to about 2 nm diameter nanoparticle. Both values of lattice volume and melting point obtained for nanosized materials are used to calculate lattice thermal expansion by using a formula applicable for tetrahedral semiconductors. Results for Si, change from 3.7 × 10{sup ?6} K{sup ?1} for a bulk crystal down to a minimum value of 0.1 × 10{sup ?6} K{sup ?1} for a 6 nm diameter nanoparticle.

Omar, M.S., E-mail: dr_m_s_omar@yahoo.com [Department of Physics, College of Science, University of Salahaddin-Erbil, Arbil, Kurdistan (Iraq)

2012-11-15T23:59:59.000Z

469

Rheological Signatures of Gelation and Effect of Shear Melting on Aging Colloidal Suspension  

E-Print Network [OSTI]

Colloidal suspensions that are out of thermodynamic equilibrium undergo physical aging wherein their structure evolves to lower the free energy. In aqueous suspension of Laponite, physical aging accompanies increases of elastic and viscous moduli as a function of time. In this work we study temporal evolution of elastic and viscous moduli at different frequencies and observe that freshly prepared aqueous suspension of Laponite demonstrates identical rheological behavior reported for the crosslinking polymeric materials undergoing chemical gelation. Consequently at a certain time tan{\\delta} is observed to be independent of frequency. However, for samples preserved under rest condition for longer duration before applying the shear melting, the liquid to solid transition subsequent to shear melting shows greater deviation from classical gelation. We also obtain continuous relaxation time spectra from the frequency dependence of viscous modulus. We observe that, with increase in the rest time, continuous relaxation time spectrum shows gradual variation from negative slope, describing dominance of fast relaxation modes to positive slope representing dominance of slow relaxation modes. We propose that the deviation from gelation behavior for the shear melted suspensions originates from inability of shear melting to completely break the percolated structure thereby creating unbroken aggregates. The volume fraction of such unbroken aggregates increases with the rest time. For small rest times presence of fewer number of unbroken aggregates cause deviation from the classical gelation. On the other hand, at high rest times presence of greater fraction of unbroken aggregates subsequent to shear melting demonstrate dynamic arrest leading to inversion of relaxation time spectra.

Shweta Jatav; Yogesh M Joshi

2014-03-05T23:59:59.000Z

470

Measurements of Aerosol Charge and Size Distribution for Graphite, Gold, Palladium, and Silver Nanoparticles  

SciTech Connect (OSTI)

The role of charge on aerosol evolution and hence the nuclear source term has been an issue of interest, and there is a need for both experimental techniques and modeling for quantifying this role. Our focus here is on further exploration of a tandem differential mobility analyzer (TDMA) technique to simultaneously measure both the size and charge (positive, negative and neutral) dependent aerosol distributions. We have generated graphite, gold, silver, and palladium nanoparticles (aerosol) using a spark generator. We measure the electrical mobility-size distributions for these aerosols using a TDMA, and from these data we deduce the full charge-size distributions. We observe asymmetry in the particle size distributions for negative and positive charges. This asymmetry could have a bearing on the dynamics of charged aerosols, indicating that the assumption of symmetry for size distributions of negatively and positively charged particles in source term simulations may not be always appropriate. Also, the experimental technique should find applications in measurements of aerosol rate processes that are affected by both particle charge and size (e.g. coagulation, deposition, resuspension), and hence in modeling and simulation of the nuclear source term.

Simones, Matthew P.; Gutti, Veera R.; Meyer, Ryan M.; Loyalka, Sudarshan K.

2011-11-01T23:59:59.000Z

471

Adsorption of 4He on graphitized carbon in the submonolayer region between 2 and 15°K  

Science Journals Connector (OSTI)

The adsorption of 4He on graphitized carbon (Spheron 6) was studied at submonolayer coverages between 2 and 15°K. Heat capacities heats of adsorption(measured calorimetrically) and equilibrium pressures are reported. The data indicate that adsorbed helium remains localized up to at least 15°K. A phase transition is observed at temperatures above 9°K for the 22.26 cm3 STP/g adsorbent coverage. Frequencies of three?dimensional asymmetric localized harmonic oscillators which can reproduce the experimental results are given. Excited levels are heavily populated at the temperatures of measurement. The zero point energy of adsorbed helium is approximately 200 J/mole. Another change in the state of adsorbed helium takes place below 7°K to the lowest temperature attained 2°K. The rate of this change in the state of adsorbed helium follows first order kinetics. It is suggested that this process involves the ’’falling’’ of the adatoms from higher to lower levels as the temperature is lowered. The residual entropies are calculated for two coverages. The residual entropy is attributed to the distribution of helium atoms over the localized surface sites.

A. A. Antoniou

1975-01-01T23:59:59.000Z

472

Effect of graphite oxide solution concentration on the properties of multilayer graphene  

SciTech Connect (OSTI)

This paper reports the influence of graphite oxide (GO) solution concentration on the optical and electrical properties of multilayer graphene (MLG) films. Graphene oxide (GrO) films were deposited on the glass substrates by spin coating aqueous solutions of GO with different concentrations (7, 8, 9, 10 and 11 mg/ml). The GrO films were then thermally reduced at temperature of 500°C in argon flow for half an hour to form MLG films. Both the transmittance and sheet resistance decreased with the GO concentration from 8 mg/ml to 9 mg/ml, possibly due to thicker and uniform coverage of MLG over the substrate. However, the transmittance and sheet resistance increased rapidly as the GO concentration reached 11 mg/ml, which can be attributed to poor film quality. The MLG film obtained at concentration of 10 mg/ml showed the highest transmittance/sheet resistance ratio with 69 % transmittance and sheet resistance of 292 ± 63 k?/sq. The optimum MLG film was utilized as counter electrode in dye sensitized solar cells based on ZnO nanorods.

Umar, Marjoni Imamora Ali [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia and Department of Physics Education, Faculty of Tarbiyah, Sekolah Tinggi Agama Islam Negeri (STAIN) Batusangkar, 27213, West (Indonesia); Yap, Chi Chin; Awang, Rozidawati; Yahaya, Muhammad [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Salleh, Muhamad Mat [Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

2013-11-27T23:59:59.000Z

473

Phase diagram of the CF{sub 4} monolayer and bilayer on graphite  

SciTech Connect (OSTI)

We report an experimental study of physisorbed monolayers and bilayers of CF{sub 4} on graphite using infrared reflection absorption spectroscopy supplemented by ellipsometry. The symmetric C–F stretch mode ?{sub 3} near 1283 cm{sup ?1} in the gas is strongly blue shifted in the film by dynamic dipole coupling. This blue shift provides a very sensitive measure of the inter-molecular spacing in the monolayer and, less directly, in the bilayer. We find that important corrections are necessary to the volumetric coverage scales used in previous heat capacity and x-ray diffraction studies of this system. This requires quantitative and some qualitative changes to the previously proposed phase diagram. We find evidence for a new phase transition in the middle of the hexagonal incommensurate region and construct new phase diagrams in both the variables coverage-temperature and chemical potential-temperature. We determine the compressibility and thermal expansion in the low-pressure hexagonal incommensurate phase and values for the entropy change in several phase transitions. Below about 55 K there is evidence of solution of up to 7% of an impurity, most likely CO, in our monolayer but not the bilayer film.

Thomas, Petros; Hess, George B., E-mail: gbh@virginia.edu [Physics Department, University of Virginia, Charlottesville, Virginia 22904 (United States)

2014-05-21T23:59:59.000Z

474

Certain rules of formation of the block in melting brucite in an OKB-955N smelting furnace  

Science Journals Connector (OSTI)

Certain rules of columnar crystallization of periclase and of formation of the block in melting of brucite in an OKB-955N smelting furnace are...

K. V. Simonov

475

Cold Crucible Induction Melting Technology for Vitrification of High Level Waste: Development and Status in India  

SciTech Connect (OSTI)

Cold crucible induction melting is globally emerging as an alternative technology for the vitrification of high level radioactive waste. The new technology offers several advantages such as high temperature availability with long melter life, high waste loading, high specific capacity etc. Based on the laboratory and bench scale studies, an engineering scale cold crucible induction melter was locally developed in India. The melter was operated continuously to assess its performance. The electrical and thermal efficiencies were found to be in the range of 70-80 % and 10-20 % respectively. Glass melting capacities up to 200 kg m{sup -2} hr{sup -1} were accomplished using the ESCCIM. Industrially adaptable melter operating procedures for start-up, melting and pouring operations were established (author)

Sugilal, G.; Sengar, P.B.S. [Nuclear Recycle Group, Bhabha Atomic Research Centre, Trombay, Mumbai (India)

2008-07-01T23:59:59.000Z

476

Ceramic plasma-sprayed coating of melting crucibles for casting metal fuel slugs  

SciTech Connect (OSTI)

Thermal cycling and melt reaction studies of ceramic coatings plasma-sprayed on Nb substrates were carried out to evaluate the performance of barrier coatings for metallic fuel casting applications. Thermal cycling tests of the ceramic plasma-sprayed coatings to 1450 degrees C showed that HfN, TiC, ZrC, and Y2O3 coating had good cycling characteristics with few interconnected cracks even after 20 cycles. Interaction studies by 1550 degrees C melt dipping tests of the plasma-sprayed coatings also indicated that HfN and Y2O3 do not form significant reaction layer between U–20 wt.% Zr melt and the coating layer. Plasma-sprayed Y2O3 coating exhibited the most promising characteristics among HfN, TiC, ZrC, and Y2O3 coating.

K.H. Kim; C.T. Lee; C.B. Lee; R.S. Fielding; J.R. Kennedy

2013-10-01T23:59:59.000Z

477

Study on LiCl waste salt treatment process by layer melt crystallization  

SciTech Connect (OSTI)

Layer melt crystallization operated in a static mode has been applied to separate Group I and II chlorides from surrogate LiCl waste salt. The effects of operating conditions such as crystal growing rate(or flux) and initial impurity concentration on separation (or concentration) of cesium, strontium and barium involved in a LiCl melts were analyzed. In a layer crystallization process, separation was impaired by occlusion of impurities and by residual melt adhering to LiCl crystal after at the end of the process. The crystal growth rate strongly affects the crystal structure, therefore the separation efficiency, while the effect of the initial Cs and Sr concentration in LiCl molten salt was nearly negligible. (authors)

Cho, Yung-Zun; Lee, Tae-Kyo; Choi, Jung-Hoon; Eun, Hee-Chul; Park, Hwan-Seo; Kim, In-Tae; Park, Geun-Il [Korea Atomic Energy Research Institute, 1045 Daedeok-daero, Yuseong-gu, Daejeon, 305-353 (Korea, Republic of)

2013-07-01T23:59:59.000Z

478

Incorporation and distribution of rhenium in a borosilicate glass melt heat treated in a sealed ampoule  

SciTech Connect (OSTI)

We investigated a mass balance of rhenium (used as a surrogate for technetium-99) in a borosilicate glass that was mixed with excess Re source (KReO4) beyond its solubility and heat treated in a vacuum-sealed fused silica ampoule. Distribution of Re in the bulk of the glass, in a salt phase formed on the melt surface, and in condensate material deposited on the ampoule wall was evaluated to understand the Re migration into different phases during the reaction between the molten glass and KReO4. The information gained from this study will contribute to an effort to understand the mechanism of technetium retention in or escape from glass melt during early stages of glass batch melting, which is a goal of the present series of studies.

Kim, Dong-Sang; Schweiger, Michael J.

2013-07-25T23:59:59.000Z

479

Nuclear Arms Control R&D Consortium includes Los Alamos  

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

Nuclear Arms Control R&D Consortium includes Los Alamos Nuclear Arms Control R&D Consortium includes Los Alamos A consortium led by the University of Michigan that includes LANL as...

480

Sorption of the monoterpenes ?-pinene and limonene to carbonaceous geosorbents including biochar  

Science Journals Connector (OSTI)

Abstract The sorption of two monoterpenes, ? pinene and limonene to the carbonaceous geosorbents graphite, bituminous coal, lignite coke, biochar and Pahokee peat was quantified. Polyethylene (PE) passive samplers were calibrated for the first time for these compounds by determining the PE-water partitioning coefficients and used as a tool to determine sorption to the carbonaceous geosorbents. Log KPE-water values were 3.49 ± 0.58 for ? pinene and 4.08 ± 0.27 for limonene. The sorption of limonene to all materials was stronger than that for ? pinene (differences of 0.2–1.3 log units between distribution coefficients for the monoterpenes). Placing Kd values in increasing order for ? pinene gave biochar ? Pahokee peat ? bituminous coal ? lignite coke < graphite. For limonene the order was: Pahokee peat ? biochar ? bituminous coal < graphite ? lignite coke. Micropore (defined as pores <1.5 nm) and nanopore surface area (defined as pores 1.5 nm to 50 nm) normalised carbonaceous geosorbent-water distribution coefficients were also calculated. There was no clear correlation of these distribution coefficients with SA. Elemental composition was used to assess the degree of condensation (or alteration) of the carbonaceous geosorbents. The degree of carbonisation increased in the order; Pahokee peat < lignite coke < bituminous coal < biochar < graphite, however this was not correlated with an increase in the experimental distribution coefficients.

Sarah E. Hale; Satoshi Endo; Hans Peter H. Arp; Andrew R. Zimmerman; Gerard Cornelissen

2015-01-01T23:59:59.000Z

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481

Poly(propylene)/Graphene Nanoplatelet Nanocomposites: Melt Rheological Behavior  

E-Print Network [OSTI]

* Introduction Modification of polymers by adding nanofillers as a second range of thermo- plastics, including poly(propylene) (PP),[15­19] polyethyl- ene,[20­22] poly, Z. Guo Integrated Composites Laboratory (ICL), Dan F. Smith Department of Chemical Engineering

Guo, John Zhanhu

482

Evaluation of Melt-Grown, ZnO Single Crystals for Use as Alpha-Particle Detectors  

SciTech Connect (OSTI)

As part of an ongoing investigation of the scintillation properties of zinc-oxide-based scintillators, several melt-grown, ZnO single crystals have been characterized using -particle excitation, infrared reflectance, and room temperature photoluminescence. The crystals, grown by Cermet, Inc. using a pressurized melt growth process, were doped with Group 1 elements (Li), Group 2 elements (Mg), Group 3 elements (Ga, In) and Lanthanides (Gd, Er, Tm). The goals of these studies are to better understand the scintillation mechanisms associated with various members of the ZnO scintillator family and to then use this knowledge to improve the radiation detection capabilities of ZnO-based scintillators. One application for which ZnO is particularly well suited as a scintillator is as the associated particle detector in a deuterium-tritium (D-T) neutron generator. Application requirements include the exclusion of organic materials, outstanding timing resolution, and high radiation resistance. ZnO(Ga) and ZnO(In) have demonstrated fast (sub-nanosecond) decay times with relatively low light yields, and ZnO(Ga) has been used in a powder form as the associated particle detector for a D-T neutron generator. Four promising candidate materials, ZnO, ZnO:Ga, ZnO:In,Li, and ZnO:Er,Li, were identified in this study. These four samples demonstrated sub-nanosecond decay times and alpha particle excited luminescence comparable to BC-400 fast plastic scintillator. The ZnO:Mg,Ga, ZnO:Gd, and ZnO:Li samples demonstrated appreciable slow (microsecond) decay components that would be incompatible with high-counting-rate applications.

Neal, John S [ORNL; Giles, N. C. [West Virginia University; Yang, Xiaocheng [West Virginia University; Wall, R. Andrew [Wake Forest University, Winston-Salem, NC; Ucer, Burak [Wake Forest University, Winston-Salem, NC; Williams, Richard T. [Wake Forest University, Winston-Salem, NC; Wisniewski, Dariusz J [ORNL; Boatner, Lynn A [ORNL; Rengarajan, Varatharajan [ORNL; Nause, Jeff E [ORNL; Nemeth, Bell [Cermet, Inc., Atlanta

2008-01-01T23:59:59.000Z

483

PRELIMINARY FRIT DEVELOPMENT AND MELT RATE TESTING FOR SLUDGE BATCH 6 (SB6)  

SciTech Connect (OSTI)

The Liquid Waste Organization (LWO) provided the Savannah River National Laboratory (SRNL) with a Sludge Batch 6 (SB6) composition projection in March 2009. Based on this projection, frit development efforts were undertaken to gain insight into compositional effects on the predicted and measured properties of the glass waste form and to gain insight into frit components that may lead to improved melt rate for SB6-like compositions. A series of Sludge Batch 6 (SB6) based glasses was selected, fabricated and characterized in this study to better understand the ability of frit compositions to accommodate uncertainty in the projected SB6 composition. Acceptable glasses (compositions where the Product Composition Control System (PCCS) Measurement Acceptability Region (MAR) predicted acceptable properties, good chemical durability was measured, and no detrimental nepheline crystallization was observed) can be made using Frit 418 with SB6 over a range of Na{sub 2}O and Al{sub 2}O{sub 3} concentrations. However, the ability to accommodate variation in the sludge composition limits the ability to utilize alternative frits for potential improvements in melt rate. Frit 535, which may offer improvements in melt rate due to its increased B2O3 concentration, produced acceptable glasses with the baseline SB6 composition at waste loadings of 34 and 42%. However, the PCCS MAR results showed that it is not as robust as Frit 418 in accommodating variation in the sludge composition. Preliminary melt rate testing was completed in the Melt Rate Furnace (MRF) with four candidate frits for SB6. These four frits were selected to evaluate the impacts of B{sub 2}O{sub 3} and Na{sub 2}O concentrations in the frit relative to those of Frit 418, although they are not necessarily candidates for SB6 vitrification. Higher concentrations of B{sub 2}O{sub 3} in the frit relative to that of Frit 418 appeared to improve melt rate. However, when a higher concentration of B{sub 2}O{sub 3} was coupled with a lower concentration of Na{sub 2}O relative to Frit 418, melt rate did not appear to improve. It is expected that a SB6 composition projection with less uncertainty will be received during analysis of the Tank 51 E-1 sample, which will be pulled after the completion of aluminum dissolution in August 2009. At that time, additional frit development work will be performed to seek improved melt rates while maintaining viable projected operating windows. This later work will ultimately lead to a frit recommendation for SB6.

Fox, K.; Miller, D.; Edwards, T.

2009-07-21T23:59:59.000Z

484

Melting of albite and dehydration of brucite in H2O–NaCl fluids to 9 kbars and 700–900°C: implications for partial melting and water activities during high pressure metamorphism  

Science Journals Connector (OSTI)

?The melting reaction: albite(solid)+ H2O(fluid) =albite-H2O(melt) has been determined in the presence of H2O–NaCl fluids at 5 and 9.2?kbar, and results compared with those obtained in presence of H2O–CO2 fluids....

Kirill I. Shmulovich; C. M. Graham

1996-08-01T23:59:59.000Z

485

Exergy-based analysis and efficiency evaluation for an aluminum melting furnace in a die-casting plant  

Science Journals Connector (OSTI)

The efficiency of a natural gas-fired aluminum melting furnace in a die-casting plant is examined using energy and exergy methods, to improve understanding of the burner system in the furnace and so that potential improvements can be identified. Such ... Keywords: aluminum, die-casting, efficiency, energy, exergy, melting furnace

Marc A. Rosen; Dennis L. Lee

2009-02-01T23:59:59.000Z

486

Very high-temperature impact melt products as evidence for cosmic airbursts and impacts 12,900 years ago  

Science Journals Connector (OSTI)

...Desert Glass Field, Egypt; and the Australasian...electron microscopy with energy dispersive spectroscopy (SEM-EDS...airburst with equivalent energy in terms of TNT, a cosmic...has greater melting efficiency. However, it does not...form when very high-energy lightning melts...

Ted E. Bunch; Robert E. Hermes; Andrew M.T. Moore; Douglas J. Kennett; James C. Weaver; James H. Wittke; Paul S. DeCarli; James L. Bischoff; Gordon C. Hillman; George A. Howard; David R. Kimbel; Gunther Kletetschka; Carl P. Lipo; Sachiko Sakai; Zsolt Revay; Allen West; Richard B. Firestone; James P. Kennett

2012-01-01T23:59:59.000Z

487

Controls on Eurasian coastal sea ice formation, melt onset and decay from ERS scatterometry: regional contrasts and effects of river  

E-Print Network [OSTI]

first-year sea ice (FYI) are observed in the Eurasian Arctic using the C-band (5.3 GHz) European RemoteControls on Eurasian coastal sea ice formation, melt onset and decay from ERS scatterometry and Kolyma rivers. Melt onset of the sea ice surface is associated with abrupt changes in s0 40, with values

Smith, Laurence C.

488

Melt and collapse of buried water ice: An alternative hypothesis for the formation of chaotic terrains on Mars  

E-Print Network [OSTI]

Melt and collapse of buried water ice: An alternative hypothesis for the formation of chaotic: T. Spohn Keywords: Mars chaotic terrain heat flux outflow channel Chaotic terrains if these features can form by melting and collapse of buried water ice in a confined basin. 2D thermal modelling

Utrecht, Universiteit

489

COARSENING AND SELF-ORGANIZATION IN DILUTE DIBLOCK COPOLYMER MELTS AND MIXTURES  

E-Print Network [OSTI]

COARSENING AND SELF-ORGANIZATION IN DILUTE DIBLOCK COPOLYMER MELTS AND MIXTURES KARL GLASNER RUSTUM, on the other hand, is responsible for producing self-organized patterns. We construct approximations based upon incompatible [9]. Block copoly-