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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

Brazing graphite to graphite  

DOE Patents (OSTI)

Graphite is joined to graphite by employing both fine molybdenum powder as the brazing material and an annealing step that together produce a virtually metal-free joint exhibiting properties similar to those found in the parent graphite. Molybdenum powder is placed between the faying surfaces of two graphite parts and melted to form molybdenum carbide. The joint area is thereafter subjected to an annealing operation which diffuses the carbide away from the joint and into the graphite parts. Graphite dissolved by the dispersed molybdenum carbide precipitates into the joint area, replacing the molybdenum carbide to provide a joint of virtually graphite.

Peterson, George R. (Andersonville, TN)

1976-01-01T23:59:59.000Z

2

Energy Saving Melting and Revert Reduction Technology: Aging of Graphitic Cast Irons and Machinability  

SciTech Connect

The objective of this task was to determine whether ductile iron and compacted graphite iron exhibit age strengthening to a statistically significant extent. Further, this effort identified the mechanism by which gray iron age strengthens and the mechanism by which age-strengthening improves the machinability of gray cast iron. These results were then used to determine whether age strengthening improves the machinability of ductile iron and compacted graphite iron alloys in order to develop a predictive model of alloy factor effects on age strengthening. The results of this work will lead to reduced section sizes, and corresponding weight and energy savings. Improved machinability will reduce scrap and enhance casting marketability. Technical Conclusions: ���¢�������¢ Age strengthening was demonstrated to occur in gray iron ductile iron and compacted graphite iron. ���¢�������¢ Machinability was demonstrated to be improved by age strengthening when free ferrite was present in the microstructure, but not in a fully pearlitic microstructure. ���¢�������¢ Age strengthening only occurs when there is residual nitrogen in solid solution in the Ferrite, whether the ferrite is free ferrite or the ferrite lamellae within pearlite. ���¢�������¢ Age strengthening can be accelerated by Mn at about 0.5% in excess of the Mn/S balance Estimated energy savings over ten years is 13.05 trillion BTU, based primarily on yield improvement and size reduction of castings for equivalent service. Also it is estimated that the heavy truck end use of lighter castings for equivalent service requirement will result in a diesel fuel energy savings of 131 trillion BTU over ten years.

Von L. Richards

2012-09-19T23:59:59.000Z

3

Coating method for graphite  

DOE Patents (OSTI)

A method of limiting carbon contamination from graphite ware used in induction melting of uranium alloys is provided. The graphite surface is coated with a suspension of Y/sub 2/O/sub 3/ particles in water containing about 1.5 to 4 percent by weight sodium carboxymethylcellulose.

Banker, J.G.; Holcombe, C.E. Jr.

1975-11-06T23:59:59.000Z

4

Graphite Leaching  

Science Conference Proceedings (OSTI)

The graphite moderators of retired gas-cooled nuclear reactors present a difficult challenge during demolition activities. As part of the EPRI graphite initiative on the technical issues involved in the management and disposal of irradiated nuclear graphite, this report examines the international data on leaching of radioactive isotopes from graphite, relevant to the decommissioning of graphite-moderated reactors.

2008-05-21T23:59:59.000Z

5

Innovative Graphite Removal Technology for Graphite Moderated Reactor Decommissioning  

Science Conference Proceedings (OSTI)

This report defines a trial program to support the development of a new concept for the removal of reactor graphite by remote in-situ size reduction and vacuum transfer, known as nibble-and-vacuum. This new approach to graphite retrieval has significant potential for simplifying the decommissioning process of graphite moderated reactors. It produces graphite gravel, which has potential as feedstock for processes such as gasification/steam reforming. This report includes definition of the trial program, t...

2010-09-28T23:59:59.000Z

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

Graphite Decommissioning  

Science Conference Proceedings (OSTI)

Many of the international participants in the EPRI Decommissioning Technology Program use graphite as a moderator material in their gas cooled reactors. This report reviews the current options for the management and disposal of irradiated nuclear graphite following the decommissioning of these nuclear installations. It also discusses specific issues associated with the disposal of graphite, and outlines innovative options for recycling or reusing products formed from the irradiated material.

2006-03-03T23:59:59.000Z

8

GRAPHITE EXTRUSIONS  

DOE Patents (OSTI)

A new lubricant for graphite extrusion is described. In the past, graphite extrusion mixtures have bcen composed of coke or carbon black, together with a carbonaceous binder such as coal tar pitch, and a lubricant such as petrolatum or a colloidal suspension of graphite in glycerin or oil. Sinee sueh a lubricant is not soluble in, or compatible with the biiider liquid, such mixtures were difficult to extrude, and thc formed pieees lacked strength. This patent teaches tbe use of fatty acids as graphite extrusion lubricants and definite improvemcnts are realized thereby since the fatty acids are soluble in the binder liquid.

Benziger, T.M.

1959-01-20T23:59:59.000Z

9

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

10

Electrical Resistance of Graphitic and Graphitized Cathode ...  

Science Conference Proceedings (OSTI)

The electrical resistance of graphitic and graphitized cathode materials before and after electrolysis was also measured at temperatures from 30°C to 965°C. An  ...

11

Graphite technology development plan  

Science Conference Proceedings (OSTI)

This document presents the plan for the graphite technology development required to support the design of the 350 MW(t) Modular HTGR within the US National Gas-Cooled Reactor Program. Besides descriptions of the required technology development, cost estimates, and schedules, the plan also includes the associated design functions and design requirements.

NONE

1986-07-01T23:59:59.000Z

12

HAPO GRAPHITE IRRADIATION CAPSULES  

SciTech Connect

A summary is presented of the broad field of graphite irradiation capsules. The various capsule designs are considered; they include temperature- controlled and temperature-monitored capsules. The components and materials of the capsules are described. Finally, methods are given for carrying out heat trandsfer calculations in capsule design and neutron spectra calculations for correlation of radiation data from different reactors. (D.L.C.)

Helm, J.W.

1963-09-18T23:59:59.000Z

13

Graphite Dust Deflagration  

Science Conference Proceedings (OSTI)

The graphite moderators of retired gas-cooled nuclear reactors present a difficult challenge during demolition activities. As part of the EPRI graphite initiative on the technical issues involved in the management and disposal of irradiated nuclear graphite, this report examines the international data on dust deflagration relevant to the decommissioning of graphite-moderated reactors. The report concludes that the risk of an explosion involving graphite dust during decommissioning is extremely low, and s...

2007-03-27T23:59:59.000Z

14

Graphite Dust Deflagration  

Science Conference Proceedings (OSTI)

The graphite moderators of retired gas-cooled nuclear reactors present a difficult challenge during demolition activities. As part of the EPRI graphite initiative on the technical issues involved in the management and disposal of irradiated nuclear graphite, EPRI Report 1014797 Graphite Dust Deflagration: A Review of International Data with Particular Reference to the Decommissioning of Graphite Moderated Reactors (March 2007) examined the international data on dust deflagration relevant to the decommiss...

2007-10-03T23:59:59.000Z

15

Melting Snowflakes  

Science Conference Proceedings (OSTI)

Many snowflakes in various melting stages were directly sampled at the, ground in almost the same way as described by Knight. From these observations the degrees of melting of snowflakes are classified into five stages. Breakup behavior of ...

Yasushi Fujiyoshi

1986-02-01T23:59:59.000Z

16

Evaluation of the graphite electrode arc melter for processing heterogeneous waste  

SciTech Connect

The U.S. Bureau of Mines (USBM) conducted a series of 4 demonstration melting tests in a 3-phase AC graphite electrode arc furnace at its Albany Research Center (ALRC) thermal treatment facility in Albany, Oregon (now part of the U.S. Department of Energy, DOE). The scope of these tests provides a unique opportunity to evaluate a single melting technology regarding its applicability to the treatment of several different heterogeneous mixed wastes. The current system can continuously process combustible-bearing wastes at feedrates to 682 kg/h (1,500 lb/h), continuously tap slag or glass, and intermittently tap metal products, and includes a close-coupled thermal oxidizer and air pollution control system (APCS). The 4 demonstration melting tests were conducted in cooperation with the American Society of Mechanical Engineers (ASME), the Idaho National Engineering Laboratory (INEL), and the Westinghouse Hanford Company (WHC).

O' Connor, William K.; Turner, Paul C.; Soelberg, N.R. (Idaho National Engineering Laboratory); Anderson, G.L. (Idaho National Engineering Laboratory)

1996-01-01T23:59:59.000Z

17

Modeling Fission Product Sorption in Graphite Structures  

SciTech Connect

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

18

Thermally Conductive Graphite Foam  

oriented graphite planes, similar to high performance carbon fibers, which have been estimated to exhibit a thermal conductivity greater than 1700 ...

19

Baseline Graphite Initial Mechanical Test Report  

SciTech Connect

The Next Generation Nuclear Plant (NGNP) Project is tasked with selecting a high temperature gas reactor technology that will be capable of generating electricity and supplying large amounts of process heat. The NGNP is presently being designed as a helium-cooled high temperature gas reactor (HTGR) with a large graphite core. The graphite baseline characterization project is conducting the research and development (R&D) activities deemed necessary to fully qualify nuclear-grade graphite for use in the NGNP reactor. One of the major fundamental objectives of the project is establishing nonirradiated thermomechanical and thermophysical properties by characterizing lot-to-lot and billet-to-billet variations (for probabilistic baseline data needs) through extensive data collection and statistical analysis. The reactor core will be made up of stacks of graphite moderator blocks. In order to gain a more comprehensive understanding of the varying characteristics in a wide range of suitable graphites, any of which can be classified as “nuclear grade,” an experimental program has been initiated to develop an extensive database of the baseline characteristics of numerous candidate graphites. Various factors known to affect the properties of graphite will be investigated, including specimen size, spatial location within a graphite billet, specimen orientation within a billet (either parallel to [P] or transverse to [T] the long axis of the as-produced billet), and billet-to-billet variations within a lot or across different production lots. Because each data point is based on a certain position within a given billet of graphite, particular attention must be paid to the traceability of each specimen and its spatial location and orientation within each billet. The evaluation of these properties is discussed in the Graphite Technology Development Plan (Windes et. al 2007). One of the key components in the evaluation of these graphite types will be mechanical testing of specimens drawn from carefully controlled sections of each billet. This report is confirmation that the test procedures are in place and approved, and that mechanical testing of graphite under the Baseline Graphite Characterization program has commenced.

Mark Carroll; Randy Lloyd

2009-09-01T23:59:59.000Z

20

NEW METHOD OF GRAPHITE PREPARATION  

DOE Patents (OSTI)

BS>A method is described for producing graphite objects comprising mixing coal tar pitch, carbon black, and a material selected from the class comprising raw coke, calcined coke, and graphite flour. The mixture is placed in a graphite mold, pressurized to at least 1200 psi, and baked and graphitized by heating to about 2500 deg C while maintaining such pressure. (AEC)

Stoddard, S.D.; Harper, W.T.

1961-08-29T23:59:59.000Z

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

Surface treated natural graphite as anode material for high-power Li-ion battery applications.  

Science Conference Proceedings (OSTI)

High power application of Li-ion battery in hybrid electrical vehicles requires low cost and safe cell materials. Among the various carbon anode materials used in lithium ion batteries, natural graphite shows the most promise with advantages in performance and cost. However, natural graphite is not compatible with propylene carbonate (PC)-based electrolytes, which have a lower melting point and improved safety characteristics. The problem with it is that the molecules of propylene carbonate intercalate with Li+ into graphite, and that frequently leads to the exfoliation of the graphite matrix.

Liu, J.; Vissers, D. R.; Amine, K.; Barsukov, I. V.; Henry, F.; Doniger, J.; Chemical Engineering; Superior Graphite Co.

2006-01-01T23:59:59.000Z

22

Melting Process  

Science Conference Proceedings (OSTI)

...iron. In recent years, great improvements in energy efficiency have been realized by constructing these pots from ceramic material and using either gas or electric immersion heaters to supply heat to the bath. If a central melting facility is used, liquid casting alloy is delivered either by ladle or by using...

23

Graphite design handbook  

Science Conference Proceedings (OSTI)

The objectives of the Graphite Design Handbook (GDH) are to provide and maintain a single source of graphite properties and phenomenological model of mechanical behavior to be used for design of MHTGR graphite components of the Reactor System, namely, core support, permanent side reflector, hexagonal reflector elements, and prismatic fuel elements; to provide a single source of data and material models for use in MHTGR graphite component design, performance, and safety analyses; to present properties and equations representing material models in a form which can be directly used by the designer or analyst without the need for interpretation and is compatible with analytical methods and structural criteria used in the MHTGR project, and to control the properties and material models used in the MHTGR design and analysis to proper Quality Assurance standards and project requirements. The reference graphite in the reactor internal components is the nuclear grade 2020. There are two subgrades of interest, the cylinder nuclear grade and the large rectangular nuclear grade. The large rectangular nuclear grade is molded in large rectangular blocks. It is the reference material for the permanent side reflector and the central column support structure. The cylindrical nuclear grade is isostatically pressed and is intended for use as the core support component. This report gives the design properties for both H-451 and 2020 graphite as they apply to their respective criteria. The properties are presented in a form for design, performance, and safety calculations that define or validate the component design. 103 refs., 20 figs., 19 tabs.

Ho, F.H.

1988-09-01T23:59:59.000Z

24

Final report on graphite irradiation test OG-2  

SciTech Connect

Results are presented of dimensional, thermal expansivity, thermal conductivity, Young's modulus, and tensile strength measurements on specimens of nuclear graphites irradiated in capsule OG-2. About half the irradiation space was allocated to H-451 near-isotropic petroleum-coke-based graphite or its subsized prototype grade H-429. Most of these specimens had been previously irradiated. Virgin specimens of another near-isotropic graphite, grade TS-1240, were irradiated. Some previously irradiated specimens of needle-coke-based H-327 graphite and pitch-coke-based P$sub 3$JHAN were also included.

Price, R.J.; Beavan, L.A.

1975-12-15T23:59:59.000Z

25

Recompressed exfoliated graphite articles  

DOE Patents (OSTI)

This invention provides an electrically conductive, less anisotropic, recompressed exfoliated graphite article comprising a mixture of (a) expanded or exfoliated graphite flakes; and (b) particles of non-expandable graphite or carbon, wherein the non-expandable graphite or carbon particles are in the amount of between about 3% and about 70% by weight based on the total weight of the particles and the expanded graphite flakes combined; wherein the mixture is compressed to form the article having an apparent bulk density of from about 0.1 g/cm.sup.3 to about 2.0 g/cm.sup.3. The article exhibits a thickness-direction conductivity typically greater than 50 S/cm, more typically greater than 100 S/cm, and most typically greater than 200 S/cm. The article, when used in a thin foil or sheet form, can be a useful component in a sheet molding compound plate used as a fuel cell separator or flow field plate. The article may also be used as a current collector for a battery, supercapacitor, or any other electrochemical cell.

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

2013-08-06T23:59:59.000Z

26

Graphite matrix materials for nuclear waste isolation  

SciTech Connect

At low temperatures, graphites are chemically inert to all but the strongest oxidizing agents. The raw materials from which artificial graphites are produced are plentiful and inexpensive. Morover, the physical properties of artificial graphites can be varied over a very wide range by the choice of raw materials and manufacturing processes. Manufacturing processes are reviewed herein, with primary emphasis on those processes which might be used to produce a graphite matrix for the waste forms. The approach, recommended herein, involves the low-temperature compaction of a finely ground powder produced from graphitized petroleum coke. The resultant compacts should have fairly good strength, low permeability to both liquids and gases, and anisotropic physical properties. In particular, the anisotropy of the thermal expansion coefficients and the thermal conductivity should be advantageous for this application. With two possible exceptions, the graphite matrix appears to be superior to the metal alloy matrices which have been recommended in prior studies. The two possible exceptions are the requirements on strength and permeability; both requirements will be strongly influenced by the containment design, including the choice of materials and the waste form, of the multibarrier package. Various methods for increasing the strength, and for decreasing the permeability of the matrix, are reviewed and discussed in the sections in Incorporation of Other Materials and Elimination of Porosity. However, it would be premature to recommend a particular process until the overall multi-barrier design is better defined. It is recommended that increased emphasis be placed on further development of the low-temperature compacted graphite matrix concept.

Morgan, W.C.

1981-06-01T23:59:59.000Z

27

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

28

Heat exchanger using graphite foam  

DOE Patents (OSTI)

A heat exchanger is disclosed. The heat exchanger may have an inlet configured to receive a first fluid and an outlet configured to discharge the first fluid. The heat exchanger may further have at least one passageway configured to conduct the first fluid from the inlet to the outlet. The at least one passageway may be composed of a graphite foam and a layer of graphite material on the exterior of the graphite foam. The layer of graphite material may form at least a partial barrier between the first fluid and a second fluid external to the at least one passageway.

Campagna, Michael Joseph; Callas, James John

2012-09-25T23:59:59.000Z

29

Lithium Diffusion in Graphitic Carbon  

NLE Websites -- All DOE Office Websites (Extended Search)

Volume 1 Start Page 1176 Issue 8 Pagination 1176-1180 Keywords anode, diffusion, graphene, lithium ion battery, transport Abstract Graphitic carbon is currently considered the...

30

Graphitic packing removal tool  

DOE Patents (OSTI)

Graphitic packing removal tools are described for removal of the seal rings in one piece from valves and pumps. The packing removal tool has a cylindrical base ring the same size as the packing ring with a surface finish, perforations, knurling or threads for adhesion to the seal ring. Elongated leg shanks are mounted axially along the circumferential center. A slit or slits permit insertion around shafts. A removal tool follower stabilizes the upper portion of the legs to allow a spanner wrench to be used for insertion and removal.

Meyers, K.E.; Kolsun, G.J.

1996-12-31T23:59:59.000Z

31

Baseline Graphite Characterization: First Billet  

SciTech Connect

The Next Generation Nuclear Plant Project Graphite Research and Development program is currently establishing the safe operating envelope of graphite core components for a very high temperature reactor design. To meet this goal, the program is generating the extensive amount of quantitative data necessary for predicting the behavior and operating performance of the available nuclear graphite grades. In order determine the in-service behavior of the graphite for the latest proposed designs, two main programs are underway. The first, the Advanced Graphite Creep (AGC) program, is a set of experiments that are designed to evaluate the irradiated properties and behavior of nuclear grade graphite over a large spectrum of temperatures, neutron fluences, and compressive loads. Despite the aggressive experimental matrix that comprises the set of AGC test runs, a limited amount of data can be generated based upon the availability of space within the Advanced Test Reactor and the geometric constraints placed on the AGC specimens that will be inserted. In order to supplement the AGC data set, the Baseline Graphite Characterization program will endeavor to provide supplemental data that will characterize the inherent property variability in nuclear-grade graphite without the testing constraints of the AGC program. This variability in properties is a natural artifact of graphite due to the geologic raw materials that are utilized in its production. This variability will be quantified not only within a single billet of as-produced graphite, but also from billets within a single lot, billets from different lots of the same grade, and across different billets of the numerous grades of nuclear graphite that are presently available. The thorough understanding of this variability will provide added detail to the irradiated property data, and provide a more thorough understanding of the behavior of graphite that will be used in reactor design and licensing. This report covers the development of the Baseline Graphite Characterization program from a testing and data collection standpoint through the completion of characterization on the first billet of nuclear-grade graphite. This data set is the starting point for all future evaluations and comparisons of material properties.

Mark C. Carroll; Joe Lords; David Rohrbaugh

2010-09-01T23:59:59.000Z

32

Spent graphite fuel element processing  

SciTech Connect

The Department of Energy currently sponsors two programs to demonstrate the processing of spent graphite fuel elements. General Atomic in San Diego operates a cold pilot plant to demonstrate the processing of both US and German high-temperature reactor fuel. Exxon Nuclear Idaho Company is demonstrating the processing of spent graphite fuel elements from Rover reactors operated for the Nuclear Rocket Propulsion Program. This work is done at Idaho National Engineering Laboratory, where a hot facility is being constructed to complete processing of the Rover fuel. This paper focuses on the graphite combustion process common to both programs.

Holder, N.D.; Olsen, C.W.

1981-07-01T23:59:59.000Z

33

Using Graphite to view network data  

NLE Websites -- All DOE Office Websites (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

34

Program on Technology Innovation: Graphite Waste Separation  

Science Conference Proceedings (OSTI)

The graphite moderators of retired gas-cooled nuclear reactors present a difficult challenge during demolition activities. There is a widespread view that disposal would be greatly facilitated if carbon-14 could be removed from the graphite blocks. As part of the EPRI graphite initiative on the technical issues involved in the management and disposal of irradiated nuclear graphite, this report describes an engineering feasibility study of graphite radioisotope separation technology. The report evaluates ...

2008-03-10T23:59:59.000Z

35

Melt dumping in string stabilized ribbon growth  

DOE Patents (OSTI)

A method and apparatus for stabilizing the edge positions of a ribbon drawn from a melt includes the use of wettable strings drawn in parallel up through the melt surface, the ribbon being grown between the strings. A furnace and various features of the crucible used therein permit continuous automatic growth of flat ribbons without close temperature control or the need for visual inspection.

Sachs, Emanuel M. (42 Old Middlesex Rd., Belmont, MA 02178)

1986-12-09T23:59:59.000Z

36

Status of Initial Assessment of Physical and Mechanical Properties of Graphite Grades for NGNP Appkications  

Science Conference Proceedings (OSTI)

Current candidate graphite grades for the core structures of NGNP include grades NBG-17, NBG-18, PCEA and IG-430. Both NBG-17 and NBG-18 are manufactured using pitch coke, and are vibrationally molded. These medium grain products are produced by SGL Carbon SAS (France). Tayo Tanso (Japan) produces IG-430 which is a petroleum coke, isostatically molded, nuclear grade graphite. And PCEA is a medium grain, extruded graphite produced by UCAR Carbon Co. (USA) from petroleum coke. An experimental program has been initiated to develop physical and mechanical properties data for these current candidate graphites. The results will be judged against the requirements for nuclear grade graphites set forth in ASTM standard D 7219-05 "Standard Specification for Isotropic and Near-isotropic Nuclear Graphites". Physical properties data including thermal conductivity and coefficient of thermal expansion, and mechanical properties data including tensile, compressive and flexural strengths will be obtained using the established test methods covered in D-7219 and ASTM C 781-02 "Standard Practice for Testing Graphite and Boronated Graphite Components for High-Temperature Gas-Cooled Nuclear Reactors". Various factors known to effect the properties of graphites will be investigated. These include specimen size, spatial location within a graphite billet, specimen orientation (ag and wg) within a billet, and billet-to-billet variations. The current status of the materials characterization program is reported herein. To date billets of the four graphite grades have been procured, and detailed cut up plans for obtaining the various specimens have been prepared. Particular attention has been given to the traceability of each specimen to its spatial location and orientation within a billet.

Strizak, Joe P [ORNL; Burchell, Timothy D [ORNL; Windes, Will [Idaho National Laboratory (INL)

2011-12-01T23:59:59.000Z

37

Electron Beam Melting (EBM)  

Science Conference Proceedings (OSTI)

Oct 18, 2011 ... Additive Manufacturing of Metals: Electron Beam Melting (EBM) I Sponsored by: MS&T Organization Program Organizers: Ian D. Harris, EWI; ...

38

Electron Beam Melting  

Science Conference Proceedings (OSTI)

Oct 9, 2012 ... Additive Manufacturing of Metals: Electron Beam Melting Program Organizers: Ian Harris, EWI; Ola Harrysson, North Carolina State University; ...

39

Method and apparatus for drawing monocrystalline ribbon from a melt  

DOE Patents (OSTI)

A method and apparatus for drawing a monocrystalline ribbon or web from a melt comprising utilizing a shaping die including at least two elements spaced one from the other each having a portion thereof located below the level of the melt and another portion located above the level of the melt a distance sufficient to form a raised meniscus of melt about the corresponding element.

Ciszek, Theodore F. (Evergreen, CO); Schwuttke, Guenter H. (Poughkeepsie, NY)

1981-11-10T23:59:59.000Z

40

Composition and method for brazing graphite to graphite  

DOE Patents (OSTI)

The present invention is directed to a brazing material for joining graphite structures that can be used at temperatures up to about 2800.degree. C. The brazing material formed of a paste-like composition of hafnium carbide and uranium oxide with a thermosetting resin. The uranium oxide is converted to uranium dicarbide during the brazing operation and then the hafnium carbide and uranium dicarbide form a liquid phase at a temperature about 2600.degree. C. with the uranium diffusing and vaporizing from the joint area as the temperature is increased to about 2800.degree. C. so as to provide a brazed joint consisting essentially of hafnium carbide. This brazing temperature for hafnium carbide is considerably less than the eutectic temperature of hafnium carbide of about 3150.degree. C. The brazing composition also incorporates the thermosetting resin so that during the brazing operation the graphite structures may be temporarily bonded together by thermosetting the resin so that machining of the structures to final dimensions may be completed prior to the completion of the brazing operation. The resulting brazed joint is chemically and thermally compatible with the graphite structures joined thereby and also provides a joint of sufficient integrity so as to at least correspond with the strength and other properties of the graphite.

Taylor, Albert J. (Ten Mile, TN); Dykes, Norman L. (Oak Ridge, TN)

1984-01-01T23:59:59.000Z

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.


41

Disposal options for burner ash from spent graphite fuel. Final study report November 1993  

Science Conference Proceedings (OSTI)

Three major disposal alternatives are being considered for Fort St. Vrain Reactor (FSVR) and Peach Bottom Reactor (PBR) spent fuels: direct disposal of packaged, intact spent fuel elements; (2) removal of compacts to separate fuel into high-level waste (HLW) and low-level waste (LLW); and (3) physical/chemical processing to reduce waste volumes and produce stable waste forms. For the third alternative, combustion of fuel matrix graphite and fuel particle carbon coatings is a preferred technique for head-end processing as well as for volume reduction and chemical pretreatment prior to final fixation, packaging, and disposal of radioactive residuals (fissile and fertile materials together with fission and activation products) in a final repository. This report presents the results of a scoping study of alternate means for processing and/or disposal of fissile-bearing particles and ash remaining after combustion of FSVR and PBR spent graphite fuels. Candidate spent fuel ash (SFA) waste forms in decreasing order of estimated technical feasibility include glass-ceramics (GCs), polycrystalline ceramic assemblages (PCAs), and homogeneous amorphous glass. Candidate SFA waste form production processes in increasing order of estimated effort and cost for implementation are: low-density GCs via fuel grinding and simultaneous combustion and waste form production in a slagging cyclone combustor (SCC); glass or low-density GCs via fluidized bed SFA production followed by conventional melting of SFA and frit; PCAs via fluidized bed SFA production followed by hot isostatic pressing (HIPing) of SFA/frit mixtures; and high-density GCs via fluidized bed SFA production followed by HIPing of Calcine/Frit/SFA mixtures.

Pinto, A.P.

1994-08-01T23:59:59.000Z

42

Melting and casting of FeAl-based cast alloy  

SciTech Connect

The FeAl-based intermetallic alloys are of great interest because of their low density, low raw material cost, and excellent resistance to high-temperature oxidation, sulfidation, carburization, and molten salts. The applications based on these unique properties of FeAl require methods to melt and cast these alloys into complex-shaped castings and centrifugal cast tubes. This paper addresses the melting-related issues and the effect of chemistry on the microstructure and hardness of castings. It is concluded that the use of the Exo-Melt{trademark} process for melting and the proper selection of the aluminum melt stock can result in porosity-free castings. The FeAl alloys can be melted and cast from the virgin and revert stock. A large variation in carbon content of the alloys is possible before the precipitation of graphite flakes occurs. Titanium is a very potent addition to refine the grain size of castings. A range of complex sand castings and two different sizes of centrifugal cast tubes of the alloy have already been cast.

Sikka, V.K. [Oak Ridge National Lab., TN (United States); Wilkening, D. [Columbia Falls Aluminum Co., Columbia Falls, MT (United States); Liebetrau, J.; Mackey, B. [AFFCO, L.L.C., Anaconda, MT (United States)

1998-11-01T23:59:59.000Z

43

Improved MK42 Melting Model  

Science Conference Proceedings (OSTI)

An improved Mark 42 melting model has been defined for establishing confinement protection limits (CPLs). This report describes the new melting model and its application in computing CPLs.

Tudor, A.A.

2001-09-19T23:59:59.000Z

44

AGC-2 Graphite Preirradiation Data Package  

SciTech Connect

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

45

Graphite in Science and Nuclear Technique  

E-Print Network (OSTI)

The monograph is devoted to the application of graphite and graphite composites in science and technology. The structure and electrical properties, the technological aspects of production of high-strength synthetic graphites, the dynamics of the graphite destruction, traditionally used in the nuclear industry are discussed. It is focuses on the characteristics of graphitization and properties of graphite composites based on carbon isotope 13C. The book is based, generally, on the original results, and concentrated on the actual problems of application and testing of graphite materials in modern nuclear physics, in scientific and technical applications. For scientists and engineers specializing in nuclear physics and engineering, physics of nuclear reactors, condensed matter, for undergraduate, graduate and post-graduate students of universities physical specialties.

Zhmurikov, E I; Pokrovsky, A S; Harkov, D V; Dremov, V V; Samarin, S I

2013-01-01T23:59:59.000Z

46

Graphite in Science and Nuclear Technique  

E-Print Network (OSTI)

The monograph is devoted to the application of graphite and graphite composites in science and technology. The structure and electrical properties, the technological aspects of production of high-strength synthetic graphites, the dynamics of the graphite destruction, traditionally used in the nuclear industry are discussed. It is focuses on the characteristics of graphitization and properties of graphite composites based on carbon isotope 13C. The book is based, generally, on the original results, and concentrated on the actual problems of application and testing of graphite materials in modern nuclear physics, in scientific and technical applications. For scientists and engineers specializing in nuclear physics and engineering, physics of nuclear reactors, condensed matter, for undergraduate, graduate and post-graduate students of universities physical specialties.

E. I. Zhmurikov; I. A. Bubnenkov; A. S. Pokrovsky; D. V. Harkov; V. V. Dremov; S. I. Samarin

2013-07-07T23:59:59.000Z

47

Composition and method for brazing graphite to graphite  

DOE Patents (OSTI)

A brazing material is described for joining graphite structures that can be used up to 2800/sup 0/C. The brazing material is formed of a paste-like composition of hafnium carbide and uranium oxide with a thermosetting resin. The uranium oxide is converted to uranium dicarbide during the brazing operation and then the hafnium carbide and uranium dicarbide form a liquid phase at a temperature about 2600/sup 0/C with the uranium diffusing and vaporizing from the joint area as the temperature is increased to about 2800/sup 0/C so as to provide a brazed joint consisting essentially of hafnium carbide. The resulting brazed joint is chemically and thermally compatible with the graphite structures.

Taylor, A.J.; Dykes, N.L.

1982-08-10T23:59:59.000Z

48

The Effect of Neutron Irradiation on the Fracture Toughness of Graphite  

SciTech Connect

As part of our irradiated graphite recycle program a small quantity of PCEA grade graphite was irradiated in the High Flux Isotope Reactor (HFIR) at ORNL. The graphite will provide the raw material for future recycle experiments. The geometry of the irradiated graphite allowed us to study the effects of neutron irradiation on the Critical Stress Intensity Factor, KIc, of graphite. The specimens where irradiated in two groups of 6 at an irradiation temperature of 900 C in rabbit capsules to doses of 6.6 and 10.2 DPA, respectively. Following a full suite of pre-and post-irradiation examination, which included dimensions, mass, electrical resistivity, elastic constants, and thermal expansion (to 800 C) the samples were notched and tested to determine their KIc using the newly approved ATSM test method for SENB fracture toughness of graphite. Here we report the irradiation induced changes in the dimensions, elastic constants, resistivity, and coefficient of thermal expansion of PCEA graphite. Moreover, irradiation induced changes in the Critical Stress Intensity Factor, KIc, or fracture toughness, are reported and discussed. Very little work on the effect of neutron irradiation on the fracture toughness of graphite has previously be performed or reported.

Burchell, Timothy D [ORNL; Strizak, Joe P [ORNL

2012-01-01T23:59:59.000Z

49

Graphite Reactor | ornl.gov  

NLE Websites -- All DOE Office Websites (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

50

AGC-3 Graphite Preirradiation Data Analysis Report  

SciTech Connect

This report describes the specimen loading order and documents all pre-irradiation examination material property measurement data for the graphite specimens contained within the third Advanced Graphite Capsule (AGC-3) irradiation capsule. The AGC-3 capsule is third in six planned irradiation capsules comprising the Advanced Graphite Creep (AGC) test series. The AGC test series is used to irradiate graphite specimens allowing quantitative data necessary for predicting the irradiation behavior and operating performance of new nuclear graphite grades to be generated which will ascertain the in-service behavior of the graphite for pebble bed and prismatic Very High Temperature Reactor (VHTR) designs. The general design of AGC-3 test capsule is similar to the AGC-2 test capsule, material property tests were conducted on graphite specimens prior to loading into the AGC-3 irradiation assembly. However the 6 major nuclear graphite grades in AGC-2 were modified; two previous graphite grades (IG-430 and H-451) were eliminated and one was added (Mersen’s 2114 was added). Specimen testing from three graphite grades (PCEA, 2114, and NBG-17) was conducted at Idaho National Laboratory (INL) and specimen testing for two grades (IG-110 and NBG-18) were conducted at Oak Ridge National Laboratory (ORNL) from May 2011 to July 2013. This report also details the specimen loading methodology for the graphite specimens inside the AGC-3 irradiation capsule. The AGC-3 capsule design requires "matched pair" creep specimens that have similar dose levels above and below the neutron flux profile mid-plane to provide similar specimens with and without an applied load. This document utilized the neutron flux profile calculated for the AGC-3 capsule design, the capsule dimensions, and the size (length) of the selected graphite and silicon carbide samples to create a stacking order that can produce "matched pairs" of graphite samples above and below the AGC-3 capsule elevation mid-point to provide specimens with similar neutron dose levels.

William Windes; David Swank; David Rohrbaugh; Joseph Lord

2013-09-01T23:59:59.000Z

51

Nuclear reactor shield including magnesium oxide  

DOE Patents (OSTI)

An improvement in nuclear reactor shielding of a type used in reactor applications involving significant amounts of fast neutron flux, the reactor shielding including means providing structural support, neutron moderator material, neutron absorber material and other components as described below, wherein at least a portion of the neutron moderator material is magnesium in the form of magnesium oxide either alone or in combination with other moderator materials such as graphite and iron.

Rouse, Carl A. (Del Mar, CA); Simnad, Massoud T. (La Jolla, CA)

1981-01-01T23:59:59.000Z

52

X-10 Graphite Reactor | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

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

53

Uranium Oxide Aerosol Transport in Porous Graphite  

Science Conference Proceedings (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

54

Brookhaven Graphite Research Reactor | Environmental Restoration...  

NLE Websites -- All DOE Office Websites (Extended Search)

Brookhaven Graphite Research Reactor(BGRR) BGRR Overview BGRR Complex Description Decommissioning Decision BGRR Complex Cleanup Actions BGRR Documents BGRR Science &...

55

Toughened Graphite Electrodes for Electric Arc Furnaces  

Benefits of Fiber Toughened Electrode Summary: Technology Description A method to more uniformly distribute graphite/carbon fibers into the electrode matrix by ...

56

SLAC National Accelerator Laboratory - LCLS Graphite Experiment...  

NLE Websites -- All DOE Office Websites (Extended Search)

LCLS Graphite Experiment Poses New Questions for Researchers By Glenn Roberts Jr. May 21, 2012 In experiments at SLAC National Accelerator Laboratory, a powerful X-ray laser...

57

THE NEXT GENERATION NUCLEAR PLANT GRAPHITE PROGRAM  

Science Conference Proceedings (OSTI)

Developing new nuclear grades of graphite used in the core of a High Temperature Gas-cooled Reactor (HTGR) is one of the critical development activities being pursued within the Next Generation Nuclear Plant (NGNP) program. Graphite’s thermal stability (in an inert gas environment), high compressive strength, fabricability, and cost effective price make it an ideal core structural material for the HTGR reactor design. While the general characteristics necessary for producing nuclear grade graphite are understood, historical “nuclear” grades no longer exist. New grades must be fabricated, characterized, and irradiated to demonstrate that current grades of graphite exhibit acceptable non-irradiated and irradiated properties upon which the thermo-mechanical design of the structural graphite in NGNP is based. The NGNP graphite R&D program has selected a handful of commercially available types for research and development activities necessary to qualify this nuclear grade graphite for use within the NGNP reactor. These activities fall within five primary areas; 1) material property characterization, 2) irradiated material property characterization, 3) modeling, and 4) ASTM test development, and 5) ASME code development efforts. Individual research and development activities within each area are being pursued with the ultimate goal of obtaining a commercial operating license for the nuclear graphite from the US NRC.

William E. Windes; Timothy D. Burchell; Robert L. Bratton

2008-09-01T23:59:59.000Z

58

Cleanup at the Brookhaven Graphite Research Reactor  

NLE Websites -- All DOE Office Websites (Extended Search)

Graphite Research Reactor placeholder Remotely operated robot known as a BROKK manipulator In April 2005, the Department of Energy (DOE), the Lab, and the regulatory agencies...

59

FUEL PROGRAMMING FOR SODIUM GRAPHITE REACTORS  

SciTech Connect

The effect of fuel programming, i.e., the scheme used for changing fuel in a core, on the reactivity and specific power of a sodium graphite reactor is discussed Fuel programs considered Include replacing fuel a core-load at a time or a radial zone at a time, replacing fuel to manutain the same average exposure of fuel elements throughout the core, and replacing and transferring fuel elements to maintain more highly exposed fuel in the center or at the periphery of the core. Flux and criticality calculations show the degree of power flattening and the concurrent decrease in effective multiplication which results from maintaining more exposed fuel toward the core center. Corverse effects are shown for the case of maintaining more exposed fuel near the core periphery. The excess reactivity which must be controlled in the various programs is considered. Illustrative schedules for implementing each of these programs in an SGR are presented. (auth)

Connolly, T.J.

1959-10-15T23:59:59.000Z

60

DWPF Macrobatch 2 Melt Rate Tests  

SciTech Connect

The Defense Waste Processing Facility (DWPF) canister production rate must be increased to meet canister production goals. Although a number of factors exist that could potentially increase melt rate, this study focused on two: (1) changes in frit composition and (2) changes to the feed preparation process to alter the redox of the melter feed. These two factors were investigated for Macrobatch 2 (sludge batch 1B) utilizing crucible studies and a specially designed ''melt rate'' furnace. Other potential factors that could increase melt rate include: mechanical mixing via stirring or the use of bubblers, changing the power skewing to redistribute the power input to the melter, and elimination of heat loss (e.g. air in leakage). The melt rate testing in FY00 demonstrated that melt rate can be improved by adding a different frit or producing a much more reducing glass by the addition of sugar as a reductant. The frit that melted the fastest in the melt rate testing was Frit 165. A paper stud y was performed using the Product Composition Control System (PCCS) to determine the impact on predicted glass viscosity, liquidus, durability, and operating window if the frit was changed from Frit 200 to Frit 165. PCCS indicated that the window was very similar for both frits. In addition, the predicted viscosity of the frit 165 glass was 46 poise versus 84 poise for the Frit 200 glass. As a result, a change from Frit 200 to Frit 165 is expected to increase the melt rate in DWPF without decreasing waste loading.

Stone, M.E.

2001-01-03T23:59:59.000Z

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

Effect of Vinylene Carbonate on Graphite Anode Cycling Efficiency  

E-Print Network (OSTI)

shift" (8). HydroQuebec's SNG-12 anode graphite was chosenElectrode laminates with SNG-12 graphite as the activePrevious experiments with SNG-12 graphite in coin cells with

Ridgway, Paul

2010-01-01T23:59:59.000Z

62

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

63

PYROMETALLURGY AND MELTING PRACTICE  

Science Conference Proceedings (OSTI)

An experimental technique has been devised for studying the reaction kinetics of the ... The system investigated was similar to the lead blast furnace slag which is ... Characterization of the recovered metal demonstrates that the performance of ... problems associated with oxygen combustion in aluminum melting furnaces.

64

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

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

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

65

Graphite/Copper Composites from Natural Wood Precursors  

Science Conference Proceedings (OSTI)

Graphite derived from natural wood precursors provides a uniquely anisotropic porous scaffold for the fabrication of graphite/copper composites. The wettability ...

66

Microstructural Characterization of Next Generation Nuclear Graphites  

Science Conference Proceedings (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

67

AGC-2 Graphite Preirradiation Data Analysis Report  

SciTech Connect

This report described the specimen loading order and documents all pre-irradiation examination material property measurement data for the graphite specimens contained within the second Advanced Graphite Capsule (AGC-2) irradiation capsule. The AGC-2 capsule is the second in six planned irradiation capsules comprising the Advanced Graphite Creep (AGC) test series. The AGC test series is used to irradiate graphite specimens allowing quantitative data necessary for predicting the irradiation behavior and operating performance of new nuclear graphite grades to be generated which will ascertain the in-service behavior of the graphite for pebble bed and prismatic Very High Temperature Reactor (VHTR) designs. Similar to the AGC-1 specimen pre-irradiation examination report, material property tests were conducted on specimens from 18 nuclear graphite types but on an increased number of specimens (512) prior to loading into the AGC-2 irradiation assembly. All AGC-2 specimen testing was conducted at Idaho National Laboratory (INL) from October 2009 to August 2010. This report also details the specimen loading methodology for the graphite specimens inside the AGC-2 irradiation capsule. The AGC-2 capsule design requires “matched pair” creep specimens that have similar dose levels above and below the neutron flux profile mid-plane to provide similar specimens with and without an applied load. This document utilized the neutron flux profile calculated for the AGC-2 capsule design, the capsule dimensions, and the size (length) of the selected graphite and silicon carbide samples to create a stacking order that can produce “matched pairs” of graphite samples above and below the AGC-2 capsule elevation mid-point to provide specimens with similar neutron dose levels.

William Windes; W. David Swank; David Rohrbaugh; Joseph Lord

2013-08-01T23:59:59.000Z

68

Retention of hydrogen in graphite  

DOE Green Energy (OSTI)

The retention of hydrogen in POCO AXF-5Q graphite has been measured at room temperature as a function of fluence and flux for H/sub 2//sup +/ ions at energies from 250 to 500 eV provided by a glow discharge. More than 2 x 10/sup 18/ H/cm/sup 2/ has been retained, and no indication of saturation has been observed to a fluence of 5 x 10/sup 19/ H/cm/sup 2/. In this experiment, retention was found to increase linearly with fluence for constant flux. A flux dependence was observed; that is, the retention rate was observed to decrease monotonically as the flux increased. A change-over experiment, deuterium to hydrogen, was conducted; the results show that significant change-over occurs (i.e., about 30% change-over for a fluence of 5 x 10/sup 17/ D/cm/sup 2/).

Langley, R.A.

1986-10-01T23:59:59.000Z

69

Graphite Oxidation Thermodynamics/Reactions  

Science Conference Proceedings (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

70

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

71

Method for molding threads in graphite panels  

DOE Patents (OSTI)

A graphite panel (10) with a hole (11) having a damaged thread (12) is repaired by drilling the hole (11) to remove all of the thread and make a new hole (13) of larger diameter. A bolt (14) with a lubricated thread (17) is placed in the new hole (13) and the hole (13) is packed with graphite cement (16) to fill the hole and the thread on the bolt. The graphite cement (16) is cured, and the bolt is unscrewed therefrom to leave a thread (20) in the cement (16) which is at least as strong as that of the original thread (12).

Short, William W. (Livermore, CA); Spencer, Cecil (Silverton, OR)

1994-01-01T23:59:59.000Z

72

Method for molding threads in graphite panels  

DOE Patents (OSTI)

A graphite panel with a hole having a damaged thread is repaired by drilling the hole to remove all of the thread and making a new hole of larger diameter. A bolt with a lubricated thread is placed in the new hole and the hole is packed with graphite cement to fill the hole and the thread on the bolt. The graphite cement is cured, and the bolt is unscrewed therefrom to leave a thread in the cement which is at least as strong as that of the original thread. 8 figures.

Short, W.W.; Spencer, C.

1994-11-29T23:59:59.000Z

73

Helium-ion-induced release of hydrogen from graphite  

DOE Green Energy (OSTI)

The ion-induced release of hydrogen from AXF-5Q graphite was studied for 350-eV helium ions. The hydrogen was implanted into the graphite with a low energy (approx.200 eV) and to a high fluence. This achieved a thin (approx.10-nm), saturated near-surface region. The release of hydrogen was measured as a function of helium fluence. A model that includes ion-induced detrapping, retrapping, and surface recombination was used to analyze the experimental data. A value of (1.65 +- 0.2) x 10/sup -16/ cm/sup 2/ was obtained from the detrapping cross section, and a value of (0.5 to 4) x 10/sup -14/ cm/sup 4//atoms was obtained for the recombination coefficient. 11 refs., 4 figs.

Langley, R.A.

1987-01-01T23:59:59.000Z

74

Electrolytic Infiltration into Laser Sintered Porous Graphite  

Science Conference Proceedings (OSTI)

Symposium, Green Technologies for Materials Manufacturing and Processing V. Presentation Title, Electrolytic Infiltration into Laser Sintered Porous Graphite ... Tensile and Fatigue Testing of 304 Stainless Steel after Gaseous Hydrogen ...

75

Immobilization of Rocky Flats Graphite Fines Residue  

Science Conference Proceedings (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

76

GRAPHITE PRODUCTION UTILIZING URANYL NITRATE HEXAHYDRATE CATALYST  

DOE Patents (OSTI)

ABS>The graphitizing of a mixture composed of furfuryl alcohol binder and uranyl nitrate hexahydrate hardener and the subsequent curing, baking, and graphitizing with pressure being initially applied prior to curing are described. The pressure step may be carried out by extrusion, methyl cellulose being added to the mixture before the completion of extrusion. Uranium oxide may be added to the graphitizable mixture prior to the heating and pressure steps. The graphitizable mixture may consist of discrete layers of different compositions. (AEC)

Sheinberg, H.; Armstrong, J.R.; Schell, D.H.

1964-03-10T23:59:59.000Z

77

Carbon-14 in Irradiated Graphite Waste  

Science Conference Proceedings (OSTI)

This report examines the international data on the formation and distribution of 14C in graphite moderators in the context of the treatment and/or disposal of the material upon reactor decommissioning. International organizations from the United States, France, Germany, Italy, Lithuania, and the United Kingdom collaborated in this program. This report provides an informed and improved understanding of the formation and behavior of 14C in irradiated graphite to determine where agreement or residual differ...

2010-12-20T23:59:59.000Z

78

Adsorption potential of alkanes on graphite  

SciTech Connect

In the framework of the extended Hueckel theory, the short-range repulsive interaction of alkanes with graphite is determined with band structure calculations from the difference between the total energy of the system (adsorbate + graphite) and the energy of the separated species. This theoretical approach enables one to determine the coefficients of the repulsive exponential term in the atom-atom potential simplified expression. The adsorption potential of alkanes on graphite is obtained when the dispersion atom-atom potential, which takes into account the high anisotropic polarizability of graphite, is added to the repulsive term. The equilibrium distance of methane on graphite and its vibrational frequency perpendicular to the surface are in good agreement with the experimental ones measured at low temperatures by neutron scattering techniques. The van der Waals radii of carbon and hydrogen atoms are obtained from the equilibrium distance of the atom-atom potential simplified expression. They are compared with those used in the literature to establish the semiempirical potential expressions. The molecular statistical theory of adsorption based on the atom-atom potential function enables one to predict the second adsorbate/surface virial coefficient and the thermodynamic characteristics of adsorption, measured for methane, ethane, and propane on graphitized carbon black at zero surface coverage by static and gas chromatographic methods.

Vidal-Madjar, C.; Minot, C.

1987-07-16T23:59:59.000Z

79

Melting of Ice under Pressure  

SciTech Connect

The melting of ice under pressure is investigated with a series of first principles molecular dynamics simulations. In particular, a two-phase approach is used to determine the melting temperature of the ice-VII phase in the range of 10 to 50 GPa. Our computed melting temperatures are consistent with existing diamond anvil cell experiments. We find that for pressures between 10 to 40 GPa, ice melts as a molecular solid. For pressures above {approx}45 GPa there is a sharp increase in the slope of the melting curve due to the presence of molecular dissociation and proton diffusion in the solid, prior to melting. The onset of significant proton diffusion in ice-VII as a function of increasing temperature is found to be gradual and bears many similarities to that of a type-II superionic solid.

Schwegler, E; Sharma, M; Gygi, F; Galli, G

2008-07-31T23:59:59.000Z

80

Nonferrous Metal Melting -- Marketing Kit  

Science Conference Proceedings (OSTI)

The industrial sector increasingly relies on electric furnaces for nonferrous metal melting due to declining electricity cost, greater use of recycled secondary nonferrous materials, and tightened environmental regulations. This Nonferrous Metal Melting -- Marketing Kit is designed to help utility sales and marketing personnel perform a progressive analysis of electrotechnology applications in nonferrous metal melting systems. The kit is designed for utility personnel who have limited knowledge of the no...

2000-07-27T23:59:59.000Z

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

Electron Beam Melting (EBM) II  

Science Conference Proceedings (OSTI)

Oct 19, 2011 ... Additive Manufacturing of Metals: Electron Beam Melting (EBM) II Sponsored by: MS&T Organization Program Organizers: Ian D. Harris, EWI; ...

82

Superalloy Melting and Cleanliness Evaluation  

Science Conference Proceedings (OSTI)

are achievable. The VAR solidification rate can be controlled by the melt rate with the large heat sink of the water cooled copper crucible producing a relatively.

83

Radar Observations and Simulation of the Melting Layer of Precipitation  

Science Conference Proceedings (OSTI)

The melting layer in precipitation is physically modeled and compared with high resolution Doppler radar data. The model includes a new formulation of the dielectric properties and can handle all ice particles with densities ranging from pure ...

Wim Klaassen

1988-12-01T23:59:59.000Z

84

Report on Thermal Neutron Diffusion Length Measurement in Reactor Grade Graphite Using MCNP and COMSOL Multiphysics  

E-Print Network (OSTI)

Neutron diffusion length in reactor grade graphite is measured both experimentally and theoretically. The experimental work includes Monte Carlo (MC) coding using 'MCNP' and Finite Element Analysis (FEA) coding suing 'COMSOL Multiphysics' and Matlab. The MCNP code is adopted to simulate the thermal neutron diffusion length in a reactor moderator of 2m x 2m with slightly enriched uranium ($^{235}U$), accompanied with a model designed for thermal hydraulic analysis using point kinetic equations, based on partial and ordinary differential equation. The theoretical work includes numerical approximation methods including transcendental technique to illustrate the iteration process with the FEA method. Finally collision density of thermal neutron in graphite is measured, also specific heat relation dependability of collision density is also calculated theoretically, the thermal neutron diffusion length in graphite is evaluated at $50.85 \\pm 0.3cm$ using COMSOL Multiphysics and $50.95 \\pm 0.5cm$ using MCNP. Finally ...

Mirfayzi, S R

2013-01-01T23:59:59.000Z

85

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

86

Core-melt source reduction system  

DOE Patents (OSTI)

A core-melt source reduction system for ending the progression of a molten core during a core-melt accident and resulting in a stable solid cool matrix. The system includes alternating layers of a core debris absorbing material and a barrier material. The core debris absorbing material serves to react with and absorb the molten core such that containment overpressurization and/or failure does not occur. The barrier material slows the progression of the molten core debris through the system such that the molten core has sufficient time to react with the core absorbing material. The system includes a provision for cooling the glass/molten core mass after the reaction such that a stable solid cool matrix results.

Forsberg, Charles W. (Oak Ridge, TN); Beahm, Edward C. (Oak Ridge, TN); Parker, George W. (Concord, TN)

1995-01-01T23:59:59.000Z

87

Core-melt source reduction system  

DOE Patents (OSTI)

A core-melt source reduction system for ending the progression of a molten core during a core-melt accident and resulting in a stable solid cool matrix. The system includes alternating layers of a core debris absorbing material and a barrier material. The core debris absorbing material serves to react with and absorb the molten core such that containment overpressurization and/or failure does not occur. The barrier material slows the progression of the molten core debris through the system such that the molten core has sufficient time to react with the core absorbing material. The system includes a provision for cooling the glass/molten core mass after the reaction such that a stable solid cool matrix results. 4 figs.

Forsberg, C.W.; Beahm, E.C.; Parker, G.W.

1995-04-25T23:59:59.000Z

88

EVALUATION OF CALANDRIA, THIMBLE, AND CANNED-MODERATOR CONCEPTS FOR SODIUM GRAPHITE REACTORS  

SciTech Connect

In efforts to improve the neutron economy and lower the capital costs of sodium graphite reactors, several methods of separating the sodium and graphite were investigated including the calandria, the thimble, and the canned moderator reactors. An analysis including nuclear, heat transfer, and economic comparisons was made of these SGR concepts. Based upon neutron economy and feasibility of core fabrication, the calandria concept appears to offer the greatest potential for improvement in 8GR design. The thimble concept provides some improvement in neutron economy but introduced numerous problems requiring developmental work. (auth)

Reed, G.L.

1960-06-10T23:59:59.000Z

89

Graphite oxidation modeling for application in MELCOR.  

SciTech Connect

The Arrhenius parameters for graphite oxidation in air are reviewed and compared. One-dimensional models of graphite oxidation coupled with mass transfer of oxidant are presented in dimensionless form for rectangular and spherical geometries. A single dimensionless group is shown to encapsulate the coupled phenomena, and is used to determine the effective reaction rate when mass transfer can impede the oxidation process. For integer reaction order kinetics, analytical expressions are presented for the effective reaction rate. For noninteger reaction orders, a numerical solution is developed and compared to data for oxidation of a graphite sphere in air. Very good agreement is obtained with the data without any adjustable parameters. An analytical model for surface burn-off is also presented, and results from the model are within an order of magnitude of the measurements of burn-off in air and in steam.

Gelbard, Fred

2009-01-01T23:59:59.000Z

90

Brookhaven Graphite Research Reactor | Environmental Restoration Projects |  

NLE Websites -- All DOE Office Websites (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

91

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.

McKernan, Mark A. (Livermore, CA); Alford, Craig S. (Tracy, CA); Makowiecki, Daniel M. (Livermore, CA); Chen, Chih-Wen (Livermore, CA)

1994-01-01T23:59:59.000Z

92

Abrupt grain boundary melting in ice  

E-Print Network (OSTI)

The effect of impurities on the grain boundary melting of ice is investigated through an extension of Derjaguin-Landau-Verwey-Overbeek theory, in which we include retarded potential effects in a calculation of the full frequency dependent van der Waals and Coulombic interactions within a grain boundary. At high dopant concentrations the classical solutal effect dominates the melting behavior. However, depending on the amount of impurity and the surface charge density, as temperature decreases, the attractive tail of the dispersion force interaction begins to compete effectively with the repulsive screened Coulomb interaction. This leads to a film-thickness/temperature curve that changes depending on the relative strengths of these interactions and exhibits a decrease in the film thickness with increasing impurity level. More striking is the fact that at very large film thicknesses, the repulsive Coulomb interaction can be effectively screened leading to an abrupt reduction to zero film thickness.

L. Benatov; J. S. Wettlaufer

2004-12-30T23:59:59.000Z

93

GlassMelt&Sealing  

NLE Websites -- All DOE Office Websites (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-

94

US graphite reactor D&D experience  

Science Conference Proceedings (OSTI)

This report describes the results of the U.S. Graphite Reactor Experience Task for the Decommissioning Strategy Plan for the Leningrad Nuclear Power Plant (NPP) Unit 1 Study. The work described in this report was performed by the Pacific Northwest National Laboratory (PNNL) for the Department of Energy (DOE).

Garrett, S.M.K.; Williams, N.C.

1997-02-01T23:59:59.000Z

95

Scaleable Clean Aluminum Melting Systems  

Science Conference Proceedings (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

96

Analysis of Natural Graphite, Synthetic Graphite, and Thermosetting Resin Candidates for Use in Fuel Compact Matrix  

Science Conference Proceedings (OSTI)

The AGR-1 and AGR-2 compacting process involved overcoating TRISO particles and compacting them in a steel die. The overcoating step is the process of applying matrix to the OPyC layer of TRISO particles in a rotating drum in order to build up an overcoat layer of desired thickness. The matrix used in overcoating is a mixture of natural graphite, synthetic graphite, and thermosetting resin in the ratio, by weight, of 64:16:20. A wet mixing process was used for AGR-1 and AGR-2, in that the graphites and resin were mixed in the presence of ethyl alcohol. The goal of the wet mixing process was to 'resinate' the graphite particles, or coat each individual graphite particle with a thin layer of resin. This matrix production process was similar to the German, Chinese, Japanese, and South African methods, which also use various amount of solvent during mixing. See Appendix 1 for information on these countries matrix production techniques. The resin used for AGR-1 and AGR-2 was provided by Hexion, specifically Hexion grade Durite SC1008. Durite SC1008 is a solvated (liquid) resole phenolic resin. A resole resin does not typically have a hardening agent added. The major constituent of SC1008 is phenol, with minor amounts of formaldehyde. Durite SC1008 is high viscosity, so additional ethyl alcohol was added during matrix production in order to reduce its viscosity and enhance graphite particle resination. The current compacting scale up plan departs from a wet mixing process. The matrix production method specified in the scale up plan is a co-grinding jet mill process where powdered phenolic resin and graphite are all fed into a jet mill at the same time. Because of the change in matrix production style, SC1008 cannot be used in the jet milling process because it is a liquid. The jet milling/mixing process requires that a suite of solid or powdered resins be investigated. The synthetic graphite used in AGR-1 and AGR-2 was provided by SGL Carbon, grade KRB2000. KRB2000 is a graphitized petroleum coke. The availability of KRB2000 is perhaps in question, so a replacement synthetic graphite may need to be identified. This report presents data on potential replacements for KRB2000.

Trammell, Michael P [ORNL; Pappano, Peter J [ORNL

2011-09-01T23:59:59.000Z

97

The electrical conductivity of sodium polysulfide melts  

DOE Green Energy (OSTI)

The sodium polysulfide melt has been described by a macroscopic model. This model considers the melt to be composed of sodium cations, monosulfide anions, and neutral sulfur solvent. The transport equations of concentrated-solution theory are used to derived the governing equations for this binaryelectrolyte melt model. These equations relate measurable transport properties to fundamental transport parameters. The focus of this research is to measure the electrical conductivity of sodium polysulfide melts and calculate one of fundamental transport parameters from the experimental data. The conductance cells used in the conductivity measurements are axisymmetric cylindrical cells with a microelectrode. The electrode effects, including double-layer capacity, charge transfer resistance, and concentration overpotential, were minimized by the use of the alternating current at an adequately high frequency. The high cell constants of the conductance cells not only enhanced the experimental accuracy but also made the electrode effects negligible. The electrical conductivities of sodium polysulfide Na{sub 2}S{sub 4} and Na{sub 2}S{sub 5} were measured as a function of temperature (range: 300 to 360{degree}C). Variations between experiments were only up to 2%. The values of the Arrhenius activation energy derived from the experimental data are about 33 kJ/mol. The fundamental transport parameter which quantifies the interaction within sodium cations and monosulfide anions are of interest and expected to be positive. Values of it were calculated from the experimental conductivity data and most of them are positive. Some negative values were obtained probably due to the experimental errors of transference number, diffusion coefficient, density or conductivity data.

Meihui Wang

1992-06-01T23:59:59.000Z

98

Nitrogen-Doped Graphitic Nanoribbons: Synthesis, Characterization and Transport  

SciTech Connect

Nitrogen-doped graphitic nanoribbons (Nx-GNRs), synthesized by chemical vapor deposition (CVD) using pyrazine as a nitrogen precursor, are reported for the first time. Scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) reveal that the synthesized materials are formed by multi-layered corrugated graphitic nanoribbons (GNRs) which in most cases exhibit the formation of curved graphene edges (loops). This suggests that during growth, nitrogen atoms promote loop formation; undoped GNRs do not form loops at their edges. Transport measurements on individual pure carbon GNRs exhibit a linear I-V (current-voltage) behavior, whereas Nx-GNRs show reduced current responses following a semiconducting-like behavior, which becomes more prominent for high nitrogen concentrations. To better understand the experimental findings, electron density of states (DOS), quantum conductance for nitrogen doped zigzag and armchair single-layer GNRs are calculated for different N doping concentrations using Density Functional Theory (DFT) and non-equilibrium Green functions. These calculations confirm the crucial role of nitrogen atoms in the transport properties, confirming that the nonlinear I-V curves are due to the presence of nitrogen atoms within the Nx-GNRs lattice that act as scattering sites. These characteristic Nx-GNRs transport could be advantageous in the fabrication of electronic devices including sensors in which metal-like undoped GNRs are unsuitable.

Jia, Xiaoting [Massachusetts Institute of Technology (MIT); Dresselhaus, M [Massachusetts Institute of Technology (MIT); Cruz Silva, Eduardo [ORNL; Munoz-Sandoval, E [Instituto de Microelectronica de Madrid (CNM, CSIC); Sumpter, Bobby G [ORNL; Terrones Maldonado, Humberto [ORNL; Terrones Maldonado, Humberto [ORNL; Lopez, Florentino [IPICyT

2013-01-01T23:59:59.000Z

99

Brookhaven Graphite Research Reactor | Environmental Restoration Projects |  

NLE Websites -- All DOE Office Websites (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

100

Removal of iron from impure graphites  

DOE Green Energy (OSTI)

Iron-impregnated and ash-rich graphites have been purified by leaching with gaseous I/sub 2/ at 900/sup 0/C. With addition of H/sub 2/, the rate of removal of impurity iron can be markedly increased and becomes comparable to that obtained with Cl/sub 2/. I/sub 2/ has an advantage in that it can also volatilize Ca and perhaps Ba and Sr.

Growcock, F.B.; Heiser, J.

1979-01-01T23:59:59.000Z

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.


101

Nondestructive Evaluation of Nuclear-Grade Graphite  

Science Conference Proceedings (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

102

Glass science tutorial: Lecture No. 4, commercial glass melting and associated air emission issues  

SciTech Connect

This document serves as a manual for a workshop on commercial glass melting and associated air emission issues. Areas covered include: An overview of the glass industry; Furnace design and construction practices; Melting furnace operation; Energy input methods and controls; Air legislation and regulations; Soda lime emission mechanisms; and, Post furnace emission controls. Supporting papers are also included.

Kruger, A.A.

1995-01-01T23:59:59.000Z

103

Raman spectroscopic studies of chemical speciation in calcium chloride melts  

DOE Green Energy (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

104

Immobilization of Rocky Flats Graphite Fines Residues  

SciTech Connect

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

105

Brookhaven Lab Completes Decommissioning of Graphite Research Reactor:  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

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.

106

Irradiation Induced Dimensional Changes in Bulk Graphite; The theory  

E-Print Network (OSTI)

Basing on experimental data on irradiation-induced deformation of graphite we introduced a concept of diffuse domain structure developed in reactor graphite produced by extrusion. Such domains are considered as random continuous deviations of local graphite texture from the global one. We elucidate the origin of domain structure and estimate the size and the degree of orientational ordering of its domains. Using this concept we explain the well known radiation-induced size effect observed in reactor graphite. We also propose a method for converting the experimental data on shape-change of finite-size samples to bulk graphite. This method gives a more accurate evaluation of corresponding data used in estimations of reactor graphite components lifetime under irradiation.

Panyukov, S V; Arjakov, M V

2012-01-01T23:59:59.000Z

107

Irradiation Induced Dimensional Changes in Bulk Graphite; The theory  

E-Print Network (OSTI)

Basing on experimental data on irradiation-induced deformation of graphite we introduced a concept of diffuse domain structure developed in reactor graphite produced by extrusion. Such domains are considered as random continuous deviations of local graphite texture from the global one. We elucidate the origin of domain structure and estimate the size and the degree of orientational ordering of its domains. Using this concept we explain the well known radiation-induced size effect observed in reactor graphite. We also propose a method for converting the experimental data on shape-change of finite-size samples to bulk graphite. This method gives a more accurate evaluation of corresponding data used in estimations of reactor graphite components lifetime under irradiation.

S. V. Panyukov; A. V. Subbotin; M. V. Arjakov

2012-10-14T23:59:59.000Z

108

Thermal Conductivity of Wood-Derived Graphite and Copper-Graphite  

SciTech Connect

The thermal conductivity of wood-derived graphite and graphite/copper composites was studied both experimentally and using finite element analysis. The unique, naturally-derived, anisotropic porosity inherent to wood-derived carbon makes standard porosity-based approximations for thermal conductivity poor estimators. For this reason, a finite element technique which uses sample microstructure as model input was utilized to determine the conductivity of the carbon phase independent of porosity. Similar modeling techniques were also applied to carbon/copper composite microstructures and predicted conductivities were compared to those determined via experiment.

Johnson, M. T. [Northwestern University, Evanston; Childers, Amanda [Northwestern University, Evanston; Ramírez-Rico, J. [Universidad de Sevilla-CSIC, Spain; Wang, Hsin [ORNL; Faber, K. T. [Northwestern University, Evanston

2013-01-01T23:59:59.000Z

109

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

110

Lithium Diffusion in Graphitic Carbon and Implications for the...  

NLE Websites -- All DOE Office Websites (Extended Search)

Carbon and Implications for the Rate Capability of Anodes Title Lithium Diffusion in Graphitic Carbon and Implications for the Rate Capability of Anodes Publication Type Journal...

111

Carbon or Graphite Foam Heating Element for Regulating Engine ...  

ORNL 2010-G00640/es UT-B ID 200000861 Carbon or Graphite Foam Heating Element for Regulating Engine Fluids Technology Summary Automotive engines need ...

112

Interaction of sodium vapor and graphite studied by ...  

Science Conference Proceedings (OSTI)

The kinetics of the reaction between graphite and sodium vapor is analyzed with support ... High temperature compression test to determine the anode paste ...

113

The Effect of Graphitization Heat Treatment Temperature on Thermal ...  

Science Conference Proceedings (OSTI)

Presentation Title, The Effect of Graphitization Heat Treatment Temperature on Thermal Properties of PAN-Based Carbon Fiber Carbon-Carbon Composites in ...

114

PROCESS OF PREPARING URANIUM-IMPREGNATED GRAPHITE BODY  

DOE Patents (OSTI)

A method for the fabrication of graphite bodies containing uniformly distributed uranium is described. It consists of impregnating a body of graphite having uniform porosity and low density with an aqueous solution of uranyl nitrate hexahydrate preferably by a vacuum technique, thereafter removing excess aqueous solution from the surface of the graphite, then removing the solvent water from the body under substantially normal atmospheric conditions of temperature and pressure in the presence of a stream of dry inert gas, and finally heating the dry impregnated graphite body in the presence of inert gas at a temperature between 800 and 1400 d C to convert the uranyl nitrate hexahydrate to an oxide of uranium.

Kanter, M.A.

1958-05-20T23:59:59.000Z

115

Characterization of Graphite from PAN Aerogels - Programmaster.org  

Science Conference Proceedings (OSTI)

PAN aerogels were aromatized oxidatively at 240°C and further treated pyrolytically to graphite under helium atmosphere at 2300°C for 24 hours. Properties of ...

116

Silicon/Graphite –Tin Nano-structured Composites Synthesized by ...  

Science Conference Proceedings (OSTI)

Presentation Title, Silicon/Graphite –Tin Nano-structured Composites Synthesized by High Energy Mechanical Milling for Lithium-ion Rechargeable Batteries ...

117

THE SODIUM GRAPHITE REACTOR: TOMMORROW'S POWER PLANT  

SciTech Connect

A description is given of the Advanced Sodium Graphite Reactor Power Plant, including the reactor, heat transfer systems, generatirg plant, control systems, and the economics of producing 256 Mw(e). The safety of this design is due to its unusually low operating pressure, absence of chemically incompatible materials in the core, and excellent stability under atatic and dynamic conditions. The reactor is being constructed at Hallam, Nebraska, at a probable cost of 0 to 0/kw, exclusive of the first core costs. The 151 fuel elements of uranium carbide are enriched to 2.75 at.% U/sup 235/ and clad in stainless steel. The average thermal neutron flux in the fuel is 8 x 10/sup 13/ n/cm/sup 2/sec. (B.O.G.)

Beeley, R.J.; Lowell, E.G.; Polak, H.; Renard, J.

1960-04-25T23:59:59.000Z

118

Note on Graphite Oxidation by Oxygen and Moisture  

DOE Green Energy (OSTI)

Simplified equations of graphite oxidation are reviewed for semi-infinite slab, finite slab, and cylinder geometries, using the principal assumptions of linearized oxidation kinetics and quasi-steady state oxidation profile. All equations are coupled to a general surface mass transfer boundary condition. The equations include those for oxidant concentration distribution, surface oxidation rate, burnoff profile, and oxidation efficiency. This review also covers some areas that may not be well recognized. The key role of the effective diffusivity is highlighted, with a brief review of measured values. The temperature-dependence of the surface oxidation rate is shown to be more complex than usually shown for the diffusion-affected zone. Assumption of linear kinetics permits ready estimation of equilibration time for development of the quasi-steady burnoff profile. In addition, approximations for the time-steady hydrogen concentration profiles are developed for the case of oxidation by H2O. All cited methods can be readily evaluated by spreadsheet calculation.

Wichner, Robert [ORNL; Burchell, Timothy D [ORNL; Contescu, Cristian I [ORNL

2009-02-01T23:59:59.000Z

119

Electron Beam Melting: The New Directional Solidification  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, Materials Science & Technology 2011. Symposium, Additive Manufacturing of Metals. Presentation Title, Electron Beam Melting: ...

120

MEASUREMENT OF MELT STRUCTURE  

DOE Green Energy (OSTI)

This Phase II research project was focused on constructing and testing a facility for the measurement of the structure of hot solid and liquid materials under extreme conditions using neutron diffraction. The work resulted in measurements at temperatures of 3300 K, the highest ever performed in a neutron beam. Work was performed jointly by Containerless Research, Inc. and Argonne National Laboratory with significant interactions with engineers and scientists at the under construction-SNS facility in Oak Ridge, TN. The work comprised four main activities: Design and construct an advanced instrument for structural studies of liquids and hot solids using neutron scattering. Develop and test a software package for instrument control, data acquisition and analysis. Test and demonstrate the instrument in experiments at the GLAD beamline at IPNS. Evaluate requirements for performing experiments at the SNS. Develop interest from the potential user base and identify potential support for Phase III. The objectives of the research were met. A second-generation instrument was developed and constructed. The instrument design drew on the results of a formal design review which was held at Argonne National Laboratory during the Phase I research [1]. The review included discussion with potential instrument users, SNS scientists and engineers and various scientists involved with materials, glass, ceramics, and geological sciences. The instrument combines aerodynamic levitation with pulsed neutron diffraction in a controlled atmosphere. An important innovation was the use of pure vanadium levitation nozzles that effectively eliminated contributions from the sample environment to the measured data. The instrument employed a 250 Watt CO2 laser that was configured for Class I laser operation. The use of Class I laser configuration meant that operators could work with the equipment with minimal restrictions and so concentrate on the research activities. Instrument control and data acquisition software was developed and implemented. As part of a larger initiative at IPNS, PC-based programs are being developed for acquisition and processing of neutron data. The PC-based beamline data handling system will enable compatibility with the levitator software. The instrument was bench tested at CRI and operated in three campaigns at the GLAD beamline at IPNS. Samples approximately 3.5 mm in diameter were levitated for periods up to 6 hours and at temperatures up to 3300 K. Structure factors were obtained for liquid oxide materials and hot solids. Details are given in this report and in published or submitted papers. During the course of the Phase I and Phase II projects, technical presentations were made at the Materials Research Society meeting in Boston, November, 2001, the American Conference on Neutron Scattering in Knoxville, TN, June, 2002, the Gordon Research Conference on High Temperature Chemistry (poster) in Waterville, ME, August 2002, the ACNS meeting in Baltimore, MD, June, 2004 and the Non-crystalline Materials-9 meeting in Corning NY, July, 2004. Two manuscripts were prepared, one is published, one is in review. The presentations have resulted in contact with the user community and we have received several requests to use the instrument. As a result, we are seeking support for collaborative research and plan to offer beamline instruments for commercial sale.

Richard Weber, Christopher Benmore

2004-10-21T23:59:59.000Z

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.


121

Thermal sprayed composite melt containment tubular component and method of making same  

DOE Patents (OSTI)

A tubular thermal sprayed melt containment component for transient containment of molten metal or alloy wherein the tubular member includes a thermal sprayed inner melt-contacting layer for contacting molten metal or alloy to be processed, a thermal sprayed heat-generating layer deposited on the inner layer, and an optional thermal sprayed outer thermal insulating layer. The thermal sprayed heat-generating layer is inductively heated as a susceptor of an induction field or electrical resistively heated by passing electrical current therethrough. The tubular thermal sprayed melt containment component can comprise an elongated melt pour tube of a gas atomization apparatus where the melt pour tube supplies molten material from a crucible to an underlying melt atomization nozzle.

Besser, Matthew F. (Urbandale, IA); Terpstra, Robert L. (Ames, IA); Sordelet, Daniel J. (Ames, IA); Anderson, Iver E. (Ames, IA)

2002-03-19T23:59:59.000Z

122

Method of preparing a negative electrode including lithium alloy for use within a secondary electrochemical cell  

DOE Patents (OSTI)

A negative electrode that includes a lithium alloy as active material is prepared by briefly submerging a porous, electrically conductive substrate within a melt of the alloy. Prior to solidification, excess melt can be removed by vibrating or otherwise manipulating the filled substrate to expose interstitial surfaces. Electrodes of such as solid lithium-aluminum filled within a substrate of metal foam are provided.

Tomczuk, Zygmunt (Palos Hills, IL); Olszanski, Theodore W. (Roselle, IL); Battles, James E. (Oak Forest, IL)

1977-03-08T23:59:59.000Z

123

Melting of foaming batches: Nuclear waste glass  

Science Conference Proceedings (OSTI)

A simple model is presented for the rate of melting of a batch blanket in an electric glassmelting furnace. The melting process is assumed to be jointly controlled by the heat transfer from the pool of molten glass and the batch-to-glass conversion kinetics. Factors affecting the melting rate in the conversion-controlled regime are discussed. Attention is paid to gas evolution from redox reactions in waste glass batches and component accumulation within the blanket. It is suggested that the high rate of the blanket-free melting in a mechanically agitated furnace is made possible by increasing the rate of melt surface renewal. 27 refs.

Hrma, P.

1990-10-01T23:59:59.000Z

124

Brookhaven Graphite Research Reactor Workshop | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

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

125

Carbon Characterization Laboratory Readiness to Receive Irradiated Graphite Samples  

SciTech Connect

The Carbon Characterization Laboratory (CCL) is located in Labs C19 and C20 of the Idaho National Laboratory Research Center. The CCL was established under the Next Generation Nuclear Plant Project to support graphite and ceramic composite research and development activities. The research conducted in this laboratory will support the Advanced Graphite Creep experiments—a major series of material irradiation experiments within the Next Generation Nuclear Plant Graphite program. The CCL is designed to characterize and test low activated irradiated materials such as high purity graphite, carbon-carbon composites, silicon-carbide composite, and ceramic materials. The laboratory is fully capable of characterizing material properties for both irradiated and nonirradiated materials. Major infrastructural modifications were undertaken to support this new radiological facility at Idaho National Laboratory. Facility modifications are complete, equipment has been installed, radiological controls and operating procedures have been established and work management documents have been created to place the CCL in readiness to receive irradiated graphite samples.

Karen A. Moore

2011-05-01T23:59:59.000Z

126

Graphite and its Hidden Superconductivity | Stanford Synchrotron Radiation  

NLE Websites -- All DOE Office Websites (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

127

MACHINING TECHNIQUES AND PROCEDURES FOR URANIUM, GRAPHITE, TITANIUM, ZIRCONIUM, THORIUM, TANTALUM, BERYLLIUM, BISMUTH, LITHIUM, AND STELLITE  

SciTech Connect

Techniqnes are presented which are applicable in machining materinls such as U, graphite, Ti, Zr, Th, Ta, Be, Bi, Li, and stellite. Included in the general considerations are factors related to machinability of the materials, operating condition of the machines, and the condition of the cutting tools. In addition, industrial hygtene and safety aspects are examined. The techniques for each material are discussed in detail, the greatest attention being focused on uranium. (J.R.D.)

Davis, C.

1952-11-01T23:59:59.000Z

128

PRELIMINARY DESIGN STUDY FOR A SODIUM-GRAPHITE-REACTOR IRRADIATION FACILITY  

SciTech Connect

The results of an investigation to integrate a Na/sup 24/ irradiation processing facility with an operating sodium graphite reactor are presented. An irradiation facility incorporated into a reference SGR (Hallam Nuclear Power Facility, Hallam, Nebraska) is described. Development of the facility application, preliminary design criteria and capital and operating costs are discussed. Recommendations for further development of the technology and economics of this type of irradiation facility are included. (auth)

Thompson, D.S.; Benaroya, V.

1959-01-31T23:59:59.000Z

129

MACHINING TECHNIQUES AND PROCEDURES FOR URANIUM, GRAPHITE, TITANIUM, ZIRCONIUM, THORIUM, TANTALUM, BERYLLIUM, BISMUTH, LITHIUM, AND STELLITE  

SciTech Connect

Techniqnes are presented which are applicable in machining materinls such as U, graphite, Ti, Zr, Th, Ta, Be, Bi, Li, and stellite. Included in the general considerations are factors related to machinability of the materials, operating condition of the machines, and the condition of the cutting tools. In addition, industrial hygtene and safety aspects are examined. The techniques for each material are discussed in detail, the greatest attention being focused on uranium.

Davis, C.

1952-11-04T23:59:59.000Z

130

Report on Thermal Neutron Diffusion Length Measurement in Reactor Grade Graphite Using MCNP and COMSOL Multiphysics  

E-Print Network (OSTI)

Neutron diffusion length in reactor grade graphite is measured both experimentally and theoretically. The experimental work includes Monte Carlo (MC) coding using 'MCNP' and Finite Element Analysis (FEA) coding suing 'COMSOL Multiphysics' and Matlab. The MCNP code is adopted to simulate the thermal neutron diffusion length in a reactor moderator of 2m x 2m with slightly enriched uranium ($^{235}U$), accompanied with a model designed for thermal hydraulic analysis using point kinetic equations, based on partial and ordinary differential equation. The theoretical work includes numerical approximation methods including transcendental technique to illustrate the iteration process with the FEA method. Finally collision density of thermal neutron in graphite is measured, also specific heat relation dependability of collision density is also calculated theoretically, the thermal neutron diffusion length in graphite is evaluated at $50.85 \\pm 0.3cm$ using COMSOL Multiphysics and $50.95 \\pm 0.5cm$ using MCNP. Finally the total neutron cross-section is derived using FEA in an inverse iteration form.

S. R. Mirfayzi

2013-01-08T23:59:59.000Z

131

Graphite Foam Heat Exchangers for Thermal Management  

Science Conference Proceedings (OSTI)

Improved thermal management is needed to increase the power density of electronic and more effectively cool electronic enclosures that are envisioned in future aircraft, spacecraft and surface ships. Typically, heat exchanger cores must increase in size to more effectively dissipate increased heat loads, this would be impossible in many cases, thus improved heat exchanger cores will be required. In this Phase I investigation, MRi aimed to demonstrate improved thermal management using graphite foam (Gr-foam) core heat exchangers. The proposed design was to combine Gr-foams from POCO with MRi's innovative low temperature, active metal joining process (S-Bond{trademark}) to bond Gr-foam to aluminum, copper and aluminum/SiC composite faceplates. The results were very favorable, so a Phase II SBIR with the MDA was initiated. This had primarily 5 tasks: (1) bonding, (2) thermal modeling, (3) cooling chip scale packages, (4) evaporative cooling techniques and (5) IGBT cold plate development. The bonding tests showed that the ''reflow'' technique with S-Bond{reg_sign}-220 resulted in the best and most consistent bond. Then, thermal modeling was used to design different chip scale packages and IGBT cold plates. These designs were used to fabricate many finned graphite foam heat sinks specifically for two standard type IC packages, the 423 and 478 pin chips. These results demonstrated several advantages with the foam. First, the heat sinks with the foam were lighter than the copper/aluminum sinks used as standards. The sinks for the 423 design made from foam were not as good as the standard sinks. However, the sinks made from foam for the 478 pin chips were better than the standard heat sinks used today. However, this improvement was marginal (in the 10-20% better regime). However, another important note was that the epoxy bonding technique resulted in heat sinks with similar results as that with the S-bond{reg_sign}, slightly worse than the S-bond{reg_sign}, but still better than the standard heat sinks. Next, work with evaporative cooling techniques, such as heat pipes, demonstrated some unique behavior with the foam that is not seen with standard wick materials. This was that as the thickness of the foam increased, the performance got better, where with standard wick materials, as the thickness increases, the performance decreases. This is yet to be completely explained. Last, the designs from the thermal model were used to fabricate a series of cold plates with the graphite foam and compare them to similar designs using high performance folded fin aluminum sinks (considered standard in the industry). It was shown that by corrugating the foam parallel to fluid flow, the pressure drop can be reduced significantly while maintaining the same heat transfer as that in the folded fin heat sink. In fact, the results show that the graphite foam heat sink can utilized 5% the pumping power as that required with the folded fin aluminum heat sink, yet remove the same amount of heat.

Klett, J.W.

2004-06-07T23:59:59.000Z

132

Brookhaven Graphite Research Reactor | Environmental Restoration Projects |  

NLE Websites -- All DOE Office Websites (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

133

Comparison of Cycling Performance of Lithium Ion Cell Anode Graphites  

NLE Websites -- All DOE Office Websites (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.

134

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 on the measurement of trace isotopes in the reactor’s graphite matrix to determine the change in their isotopic ratios due to burnup. These measurements are then coupled with reactor calculations to determine the total plutonium and energy production of the reactor. To facilitate sensitivity analysis of these methods, a one-group cross section and fission product yield library for the fuel and graphite activation products has been developed for MAGNOX-style reactors. This library is intended for use in the ORIGEN computer code, which calculates the buildup, decay, and processing of radioactive materials. The library was developed using a fuel cell model in Monteburns. This model consisted of a single fuel rod including natural uranium metal fuel, magnesium cladding, carbon dioxide coolant, and Grade A United Kingdom (UK) graphite. Using this library a complete sensitivity analysis can be performed for GIRM and other techniques. The sensitivity analysis conducted in this study assessed various input parameters including 235U and 238U cross section values, aluminum alloy concentration in the fuel, and initial concentrations of trace elements in the graphite moderator. The results of the analysis yield insight into the GIRM method and the isotopic ratios the method uses as well as the level of uncertainty that may be found in the system results.

Chesson, Kristin Elaine

2007-08-01T23:59:59.000Z

135

Pressure dependence of the c-axis resistivity of graphite  

Science Conference Proceedings (OSTI)

The c-axis resistivity of highly oriented pyrolytic graphite has been measured from 2 to 300 K under hydrostatic pressures of up to 40 kbar. A resistivity peak near 40 K, typical for this type of graphite at ambient pressure, rapidly diminishes with increasing pressure but does not shift its position with respect to temperature. This observation suggests that the origin of the resistivity peak is not in a strong electron-phonon interaction but is associated with a particular structural matrix of these artificially produced graphites. A model is proposed, based on tunneling between microcrystallites, which accounts for the peculiar temperature and pressure dependence of the resistivity.

Uher, C.; Hockey, R.L.; Ben-Jacob, E.

1987-03-15T23:59:59.000Z

136

STRESS ANALYSIS OF SPECIMENS FOR IN-PILE CREEP TESTS OF PARABOLIC GRAPHITE BEAMS  

SciTech Connect

The irradiation-induced creep of graphite is being investigated in experiments that consist of loading parabolically shaped cantilever beams at the free end and measuring the resulting deflections with time. A series of stress analyses was made to verify the applicability of the elementary strength-of- materials approach for obtaining relations between stress and creep strain from the load-deflection data. The results of the analyses, which included a theory- of-elasticity solution, an evaluation of the effect of shear, and a bending analysis using an actual stress-strain diagram for graphite, show that an elementary strength-of-materials approach is adequate to predict the initial or elastic stresses. Preliminary results from the in-pile experiments indicate that the creep strains are linear with stress; thus the initially linear bending stress distribution given by the elementary theory remains unchanged during creep. (auth)

Corum, J.M.

1964-02-01T23:59:59.000Z

137

Mechanical Behavior of Melt Mixing Polypropylene Organoclay ...  

Science Conference Proceedings (OSTI)

To study the effect of the nanocomposite dispersion and morphology, another nanocomposite was prepared by melt mixing of polypropylene and a modified ...

138

Produced by Selective Electron Beam Melting  

Science Conference Proceedings (OSTI)

The development of processing TiAl by additive manufacturing by using the selective electron beam melting (SEBM) provides a new approach to reach near

139

Flux Lattice in Superconductors and Melting  

Science Conference Proceedings (OSTI)

... Our early data suggested that there was a melting transition to a "vortex liquid" in high temperature superconductors, but it's possible relation to the ...

140

Modeling the Electrical Conductivity in Glass Melts  

Science Conference Proceedings (OSTI)

Abstract Scope, The electrical resistivity of oxide melts is important for the design and operation of electric furnaces. The electrical properties of glass and slag ...

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

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

SciTech Connect

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

142

The dependence of natural graphite anode performance on electrode density  

DOE Green Energy (OSTI)

The effect of electrode density for lithium intercalation and irreversible capacity loss on the natural graphite anode in lithium ion batteries was studied by electrochemical methods. Both the first-cycle reversible and irreversible capacities of the natural graphite anode decreased with an increase in the anode density though compression. The reduction in reversible capacity was attributed to a reduction in the chemical diffusion coefficient for lithium though partially agglomerated particles with a larger stress. For the natural graphite in this study the potentials for Li (de)insertion shifted between the first and second formation cycles and the extent of this shift was dependent on electrode density. The relation between this peak shift and the irreversible capacity loss are probably both due to the decrease in graphite surface area with compression.

Shim, Joongpyo; Striebel, Kathryn A.

2003-11-01T23:59:59.000Z

143

First Direct Evidence of Dirac Fermions in Graphite  

NLE Websites -- All DOE Office Websites (Extended Search)

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...

144

Heat conduction in graphite-nanoplatelet-reinforced polymer nanocomposites  

E-Print Network (OSTI)

89, 023117 ?2006? Heat conduction in graphite-nanoplatelet-The resistance to heat conduction across interfaces between?DOI: 10.1063/1.2221874? Heat conduction across surfaces of

Hung, M T; Choi, O; Ju, Y. Sungtaek; Hahn, H T

2006-01-01T23:59:59.000Z

145

Mechanics of fatigue damage in titanium-graphite hybrid laminates  

E-Print Network (OSTI)

Titanium-graphite hybrid laminates are being developed for high-temperature aerospace applications. Experimental observations have indicated that cracks in the titanium facesheets initiate at free edges as well as in areas ...

Burianek, Dennis Arthur

2001-01-01T23:59:59.000Z

146

First Direct Evidence of Dirac Fermions in Graphite  

NLE Websites -- All DOE Office Websites (Extended Search)

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,...

147

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

Science Conference Proceedings (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

148

An Investigation of the effect of graphite degradation on irreversible  

NLE Websites -- All DOE Office Websites (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.

149

Graphitization in C and C-Mo Steels  

Science Conference Proceedings (OSTI)

Following the recent carbon (C) and carbon-molybdenum (C-Mo) steel graphitization experience reported by several Electric Power Research Institute (EPRI) members, it became apparent that the industry could benefit from better predictive guidance to prioritize component inspections and examinations for graphitization. This research effort collected and analyzed the additional experience gained since the last EPRI project on the subject and focused on developing suitably conservative time-temperature predi...

2010-12-23T23:59:59.000Z

150

Effect of Vinylene Carbonate on Graphite Anode Cycling Efficiency  

NLE Websites -- All DOE Office Websites (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.

151

Electrical and thermal properties of graphite/polyaniline composites  

SciTech Connect

A composite of a carbon allotrope (graphite) and an inherently conducting polymer, polyaniline (PANI), has been prepared that exhibits an electrical conductivity greater than either of the two components. An almost 2-fold increase in the bulk conductivity occurs when only a small mass fraction of polyaniline exists in the composite (91% graphite/ 9% polyaniline, by mass). This increase in dc electrical conductivity is curious since in most cases a composite material will exhibit a conductivity somewhere between the two individual components, unless a modification to the electronic nature of the material occurs. In order to elucidate the fundamental electrical properties of the composite we have performed variable temperature conductivity measurements to better understand the nature of conduction in these materials. The results from these studies suggest a change in the mechanism of conduction as the amount of polyaniline is increased in the composite. Along with superior electrical properties, the composites exhibit an increase in thermal stability as compared to the graphite. - Graphical abstract: (Left) Room temperature electrical conductivity of G-PANI composites at different mass ratios. (Right) Electrical conductivity of G-PANI composites at temperatures from 5 K to 300 K. Highlights: Black-Right-Pointing-Pointer Composites of graphite and polyaniline have been synthesized with unique electrical and thermal properties. Black-Right-Pointing-Pointer Certain G-PANI composites are more conductive and more thermally stable than graphite alone. Black-Right-Pointing-Pointer G-PANI composites exhibit a larger conductivity ratio with respect to temperature than graphite alone.

Bourdo, Shawn E., E-mail: sxbourdo@ualr.edu [Center for Integrative Nanotechnology Sciences, University of Arkansas at Little Rock, 2801 South University Avenue, Little Rock, AR 72204 (United States); Warford, Brock A.; Viswanathan, Tito [Department of Chemistry, University of Arkansas at Little Rock, 2801 South University Avenue, Little Rock, AR 72204 (United States)] [Department of Chemistry, University of Arkansas at Little Rock, 2801 South University Avenue, Little Rock, AR 72204 (United States)

2012-12-15T23:59:59.000Z

152

Purification of tantalum by plasma arc melting  

DOE Green Energy (OSTI)

Purification of tantalum by plasma arc melting. The level of oxygen and carbon impurities in tantalum was reduced by plasma arc melting the tantalum using a flowing plasma gas generated from a gas mixture of helium and hydrogen. The flowing plasma gases of the present invention were found to be superior to other known flowing plasma gases used for this purpose.

Dunn, Paul S. (Santa Fe, NM); Korzekwa, Deniece R. (Los Alamos, NM)

1999-01-01T23:59:59.000Z

153

Nanotexturing of surfaces to reduce melting point.  

DOE Green Energy (OSTI)

This investigation examined the use of nano-patterned structures on Silicon-on-Insulator (SOI) material to reduce the bulk material melting point (1414 C). It has been found that sharp-tipped and other similar structures have a propensity to move to the lower energy states of spherical structures and as a result exhibit lower melting points than the bulk material. Such a reduction of the melting point would offer a number of interesting opportunities for bonding in microsystems packaging applications. Nano patterning process capabilities were developed to create the required structures for the investigation. One of the technical challenges of the project was understanding and creating the specialized conditions required to observe the melting and reshaping phenomena. Through systematic experimentation and review of the literature these conditions were determined and used to conduct phase change experiments. Melting temperatures as low as 1030 C were observed.

Garcia, Ernest J.; Zubia, David (University of Texas at El Paso El Paso, TX); Mireles, Jose (Universidad Aut%C3%94onoma de Ciudad Ju%C3%94arez Ciudad Ju%C3%94arez, Mexico); Marquez, Noel (University of Texas at El Paso El Paso, TX); Quinones, Stella (University of Texas at El Paso El Paso, TX)

2011-11-01T23:59:59.000Z

154

Design of the Next Generation Nuclear Plant Graphite Creep Experiments for Irradiation in the Advanced Test Reactor  

SciTech Connect

The United States Department of Energy’s Next Generation Nuclear Plant (NGNP) Program will be irradiating six gas reactor graphite creep experiments in the Advanced Test Reactor (ATR) located at the Idaho National Laboratory (INL). The ATR has a long history of irradiation testing in support of reactor development and the INL has been designated as the new United States Department of Energy’s lead laboratory for nuclear energy development. The ATR is one of the world’s premiere test reactors for performing long term, high flux, and/or large volume irradiation test programs. These graphite irradiations are being accomplished to support development of the next generation reactors in the United States. 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 at different temperatures and loading conditions to support design of the Next Generation Nuclear Plant Very High Temperature Gas Reactor, as well as other future gas reactors. The experiments will each consist of a single capsule that will contain seven separate stacks of graphite specimens. Six of the specimen stacks will have half of their graphite specimens under a compressive load, while the other half of the specimens will not be subjected to a compressive load during irradiation. The six stacks will be organized into pairs with a different compressive load being applied to the top half of each pair of specimen stacks. The seventh stack will not have a compressive load on the graphite specimens during irradiation. 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 the capability of sampling the sweep gas effluent to determine if any oxidation or off-gassing of the specimens occurs during initial start-up of the experiment. The final design phase for the first experiment was completed in September 2008, and the fabrication and assembly of the experiment test train as well as installation and testing of the control and support systems that will monitor and control the experiment during irradiation are being completed in early calendar 2009. The first experiment is scheduled to be ready for insertion in the ATR by April 30, 2009. This paper will discuss the design of the experiment including the test train and the temperature and compressive load monitoring, control, and data collection systems.

S. Blaine Grover

2009-05-01T23:59:59.000Z

155

Structure and Phase Transitions of Monolayers of Intermediate-length n-alkanes on Graphite Studied by Neutron Diffraction and Molecular Dynamics Simulation  

Science Conference Proceedings (OSTI)

We present evidence from neutron diffraction measurements and molecular dynamics (MD) simulations of three different monolayer phases of the intermediate-length alkanes tetracosane (n-C(24)H(50) denoted as C24) and dotriacontane (n-C(32)H(66) denoted as C32) adsorbed on a graphite basal-plane surface. Our measurements indicate that the two monolayer films differ principally in the transition temperatures between phases. At the lowest temperatures, both C24 and C32 form a crystalline monolayer phase with a rectangular-centered (RC) structure. The two sublattices of the RC structure each consists of parallel rows of molecules in their all-trans conformation aligned with their long axis parallel to the surface and forming so-called lamellas of width approximately equal to the all-trans length of the molecule. The RC structure is uniaxially commensurate with the graphite surface in its [110] direction such that the distance between molecular rows in a lamella is 4.26 A=sqrt[3a(g)], where a(g)=2.46 A is the lattice constant of the graphite basal plane. Molecules in adjacent rows of a lamella alternate in orientation between the carbon skeletal plane being parallel and perpendicular to the graphite surface. Upon heating, the crystalline monolayers transform to a 'smectic' phase in which the inter-row spacing within a lamella expands by approximately 10% and the molecules are predominantly oriented with the carbon skeletal plane parallel to the graphite surface. In the smectic phase, the MD simulations show evidence of broadening of the lamella boundaries as a result of molecules diffusing parallel to their long axis. At still higher temperatures, they indicate that the introduction of gauche defects into the alkane chains drives a melting transition to a monolayer fluid phase as reported previously.

Taub, H. [University of Missouri, Columbia; Hansen, F.Y. [Technical University of Denmark; Diama, Amand [National University of the Ivory Coast; Matthies, Blake [Goodyear Tire and Rubber Company, The; Criswell, Leah [University of Missouri, Columbia; Mo, Haiding [Advanced Optowave Corporation; Bai, M [University of Missouri, Columbia; Herwig, Kenneth W [ORNL

2009-01-01T23:59:59.000Z

156

Experiments on interactions between zirconium-containing melt and water (ZREX): Hydrogen generation and chemical augmentation of energetics  

DOE Green Energy (OSTI)

The results of the first data series of experiments on interactions between zirconium-containing melt and water are described. These experiments involved dropping 1-kg batches of pure zirconium or zirconium-zirconium dioxide mixture melt into a column of water. A total of nine tests were conducted, including four with pure zirconium melt and five with Zr-ZrO{sub 2} mixture melt. Explosions took place only in those tests which were externally triggered. While the extent of zirconium oxidation in the triggered experiments was quite extensive, the estimated explosion energetics were found to be very small compared to the combined thermal and chemical energy available.

Cho, D.H.; Armstrong, D.R.; Gunther, W.H. [Argonne National Lab., IL (United States); Basu, S. [Nuclear Regulatory Commission, Washington, DC (United States)

1997-08-01T23:59:59.000Z

157

Front Tracking Model of Simultaneous Melting and Solidification ...  

Science Conference Proceedings (OSTI)

This results in dynamic melting and solidification throughout the weld pool, which can be modelled using the authors' Front Tracking algorithm. Melting is ...

158

Non-Ferrous Melting Practice, 1946 - Title Page  

Science Conference Proceedings (OSTI)

Measurement and Control of Temperatures in Smelting, Refining and. Melting Nonferrous Metals. By P. H. DIKE and M. J. BRADLEY .... I. Melting of Brass and ...

159

Non-Ferrous Melting Practice, 1946 (Electronic Format)  

Science Conference Proceedings (OSTI)

Non-Ferrous Melting Practice examines the melting of brass, bronze, copper alloys, nickel, magnesium, aluminum, lead, and tin. This title also has information

160

Molecular stretching in polymer melts undergoing steady elongational flow.  

E-Print Network (OSTI)

Molecular stretching in polymer melts undergoing steady elongational flow. Kell Mortensen Centre DTU, Lyngby, Denmark The molecular stretching of a polymer melt undergoing steady elongational

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

Heat transfer in excimer laser melting of thin polysilicon layers  

NLE Websites -- All DOE Office Websites (Extended Search)

Heat transfer in excimer laser melting of thin polysilicon layers Title Heat transfer in excimer laser melting of thin polysilicon layers Publication Type Journal Article Year of...

162

First Direct Evidence of Dirac Fermions in Graphite  

NLE Websites -- All DOE Office Websites (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.

163

First Direct Evidence of Dirac Fermions in Graphite  

NLE Websites -- All DOE Office Websites (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.

164

First Direct Evidence of Dirac Fermions in Graphite  

NLE Websites -- All DOE Office Websites (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.

165

Method for wetting a boron alloy to graphite  

DOE Patents (OSTI)

A method is provided for wetting a graphite substrate and spreading a a boron alloy over the substrate. The wetted substrate may be in the form of a needle for an effective ion emission source. The method may also be used to wet a graphite substrate for subsequent joining with another graphite substrate or other metal, or to form a protective coating over a graphite substrate. A noneutectic alloy of boron is formed with a metal selected from the group consisting of nickel (Ni), palladium (Pd), and platinum (Pt) with excess boron, i.e., and atomic percentage of boron effective to precipitate boron at a wetting temperature of less than the liquid-phase boundary temperature of the alloy. The alloy is applied to the substrate and the graphite substrate is then heated to the wetting temperature and maintained at the wetting temperature for a time effective for the alloy to wet and spread over the substrate. The excess boron is evenly dispersed in the alloy and is readily available to promote the wetting and spreading action of the alloy. 1 fig.

Storms, E.K.

1987-08-21T23:59:59.000Z

166

Method of preparing a negative electrode including lithium alloy for use within a secondary electrochemical cell  

DOE Patents (OSTI)

A negative electrode that includes a lithium alloy as active material is prepared by briefly submerging a porous, electrically conductive substrate within a melt of the alloy. Prior to solidification, excess melt can be removed by vibrating or otherwise manipulating the filled substrate to expose interstitial surfaces. Electrodes of such a solid lithium--aluminum filled within a substrate of metal foam are provided. 1 figure, 1 table.

Tomczuk, Z.; Olszanski, W.; Battles, J.E.

1975-12-09T23:59:59.000Z

167

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

SciTech Connect

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

168

Modeling Pulsed Laser Melting of Embedded Nanoparticles  

E-Print Network (OSTI)

2 Model of Pulsed Laser Melting 2.1 Experimental Systemto be Modeled 2.2 Laser Absorption . . . . . . . . . . .a prototypical 0.3 J/cm 2 laser ?uence PLM at 0.5 J/m 2 Ge-

Sawyer, Carolyn Anne

2013-01-01T23:59:59.000Z

169

Oxygen – Permeable Solid/Melt Composite Membranes  

Science Conference Proceedings (OSTI)

Cathodic Behavior of Silicon (?) in BaF2-CaF2 –SiO2 Melts ... Electrochemical Impedance Spectroscopy of Uranium Chloride in Molten LiCl-KCl Eutectic.

170

Modeling Pulsed Laser Melting of Embedded Nanoparticles  

E-Print Network (OSTI)

equal interface energies with the matrix. The two shadedat 0.5 J/m 2 Ge-matrix interface energy. The melting plateauare the interface energies between the matrix and the liquid

Sawyer, Carolyn Anne

2013-01-01T23:59:59.000Z

171

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

SciTech Connect

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

172

PURIFICATION OF IRIDIUM BY ELECTRON BEAM MELTING  

Science Conference Proceedings (OSTI)

The purification of iridium metal by electron beam melting has been characterized for 48 impurity elements. Chemical analysis was performed by glow discharge mass spectrographic (GDMS) analysis for all elements except carbon, which was analyzed by combustion. The average levels of individual elemental impurities in the starting powder varied from 37 g/g to 0.02 g/g. The impurity elements Li, Na, Mg, P, S, Cl, K, Ca, Mn, Co, Ni, Cu, Zn, As, Pd, Ag, Cd, Sn, Sb, Te, Ba, Ce, Tl, Pb, and Bi were not detectable following the purification. No significant change in concentration of the elements Ti, V, Zr, Nb, Mo, and Re was found. The elements B, C, Al, Si, Cr, Fe, Ru, Rh, and Pt were partially removed by vaporization during electron beam melting. Langmuir's equation for ideal vaporization into a vacuum was used to calculate for each impurity element the expected ratio of impurity content after melting to that before melting. Equilibrium vapor pressures were calculated using Henry's law, with activity coefficients obtained from published data for the elements Fe, Ti, and Pt. Activity coefficients were estimated from enthalpy data for Al, Si, V, Cr, Mn, Co, Ni, Zr, Nb, Mo, and Hf and an ideal solution model was used for the remaining elements. The melt temperature was determined from measured iridium weight loss. Excellent agreement was found between measured and calculated impurity ratios for all impurity elements. The results are consistent with some localized heating of the melt pool due to rastering of the electron beam, with an average vaporization temperature of 3100 K as compared to a temperature of 2965 K calculated for uniform heating of the melt pool. The results are also consistent with ideal mixing in the melt pool.

Ohriner, Evan Keith [ORNL

2008-01-01T23:59:59.000Z

173

RADIATION HAZARDS ENCOUNTERED IN ARC MELTING THORIUM  

SciTech Connect

A project to provide information on the hazards associated wlth arc melting of Th is described. A general airsampling analysis was made to determine the separation, concentration, and distribution of Th daughter (decay) products throughout arc melting, machining, and forging processes found in a handling facility. The value of well coordinated health physics program is stressed in connection with potential health hazards and personnel protection. Building, equipment, and exhaust ventilation requirements for such a facility are discussed, along wlth special handling methods. (auth)

Lowery, R.R.

1960-11-01T23:59:59.000Z

174

Is Graphite a Diamonds Best Friend? New Information on Material  

NLE Websites -- All DOE Office Websites (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

175

Effect of Graphitic Content on Carbon Supported Catalyst Performance  

DOE Green Energy (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

176

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

177

100-MW NUCLEAR POWER PLANT UTILIZING A SODIUM COOLED, GRAPHITE MODERATED REACTOR  

SciTech Connect

The conceptual design of a 100 Mw(e) nuclear power plant is described. The plant utilized a sodium-cooled graphite-moderated reactor with stainless- steel clad. slightiy enriched UO/sub 2/ fuel. The reactor is provided with three main coolant circuits, and the steam cycle has three stages of regenerative heating. The plant control system allows automatic operation over the range of 20 to 100% load, or manual operation at all loads. The site, reactor, sodium systems, reactor auxiliaries, fuel handling, instrumentation, turbine-generator, buildings. and safety measures are described. Engineering drawings are included. (W.D.M.)

1958-02-28T23:59:59.000Z

178

Atomic hydrogen adsorption on lithium-doped graphite surfaces  

SciTech Connect

The effects of lithium doping of pristine and defective graphite surfaces on hydrogen adsorption are studied by the first-principles Plane-Wave Density Functional Theory. The surface defects are simulated by a single atomic vacancy. The DFT calculation is corrected for long-range effects through semi-empirical London terms for each constituent of the system. The lithium doping of the graphite surfaces notably reinforces hydrogen atom binding. Qualitative comparison with experimental results is given using the lithium 1s energy level shifts induced by the atomic vacancy and/or hydrogen trapping.

Allouche, Alain [CNRS/Univ. de Provence (France); Krstic, Predrag S [ORNL

2012-01-01T23:59:59.000Z

179

High strength graphite and method for preparing same  

DOE Patents (OSTI)

High strength graphite is manufactured from a mixture of a particulate filler prepared by treating a particulate carbon precursor at a temperature in the range of about 400.degree. to 1000.degree. C., an organic carbonizable binder, and green carbonizable fibers in a concentration of not more than 2 weight per cent of the filler. The use of the relatively small quantity of green fibers provides a substantial increase in the flexural strength of the graphite with only a relatively negligible increase in the modulus of elasticity.

Overholser, Lyle G. (Oak Ridge, TN); Masters, David R. (Knoxville, TN); Napier, John M. (Oak Ridge, TN)

1976-01-01T23:59:59.000Z

180

Graphit-ceramic RF Faraday-thermal shield and plasma limiter  

DOE Patents (OSTI)

The present invention is directed to a process of brazing a ceramic mater to graphite. In particular, the brazing procedure is directed to the production of a novel brazed ceramic graphite product useful as a Faraday shield.

Hwang, David L. (Princeton Junction, NJ); Hosea, Joel C. (Princeton, NJ)

1989-01-01T23:59:59.000Z

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.


181

Boron carbide-based coatings on graphite for plasma facing components  

SciTech Connect

In the effort to evaluate boron-rich coatings as plasma facing surfaces in fusion devices, a new process for applying boron carbide (B{sub 4}C) coatings to graphite was developed. The process entails eutectic melting of the carbon (C) substrate surface with a precursor layer of B{sub 4}C particles. Adherent coatings were achieved which consisted of two layers: a surface layer and a graded penetration zone in the outer portion of the substrate. The surface-layer microstructure was multiphase and ranged from reaction-sintered structures of sintered B{sub 4}C particles in an eutectic-formed matrix to that of hypereutectic carbon particles in a B{sub 4}C-C eutectic matrix. Because of high surface energy, the coating generally developed a nonuniform thickness. Quantitative evaluations of the coating were performed with limiters in the TEXTOR fusion device and with coupons in electron beam tests. Test results revealed the following: good adherence of the coating even after remelting; and, during remelting, diagnostics detected a corresponding interaction of boron with the plasma.

Valentine, P.G.; Trester, P.W. [General Atomics, San Diego, CA (United States); Winter, J.; Linke, J.; Duwe, R.; Wallura, E.; Philipps, V. [Kernforschungsanlage Juelich GmbH (Germany)

1994-01-01T23:59:59.000Z

182

Graphite curtain vacuum outgassing and heat transfer. Quarterly progress report No. 2, 1 April 1976--30 June 1976  

DOE Green Energy (OSTI)

A sodium filled heat pipe was tested in a magnetic field of up to 1 Tesla. An analysis of the heat pipe operation is given. The MHD pressure drop is calculated as a function of the Hartmann number, which includes effects of the magnetic field strength and a characteristic flow area dimension parallel to the lines of magnetic flux. Some vacuum outgassing and atomic hydrogen and helium sticking probability measurements are given for graphite fibers. (MOW)

Fivel, H.J.; Lang, G.P.

1976-01-01T23:59:59.000Z

183

Melt processing of radioactive waste: A technical overview  

Science Conference Proceedings (OSTI)

Nuclear operations have resulted in the accumulation of large quantities of contaminated metallic waste which are stored at various DOE, DOD, and commercial sites under the control of DOE and the Nuclear Regulatory Commission (NRC). This waste will accumulate at an increasing rate as commercial nuclear reactors built in the 1950s reach the end of their projected lives, as existing nuclear powered ships become obsolete or unneeded, and as various weapons plants and fuel processing facilities, such as the gaseous diffusion plants, are dismantled, repaired, or modernized. For example, recent estimates of available Radioactive Scrap Metal (RSM) in the DOE Nuclear Weapons Complex have suggested that as much as 700,000 tons of contaminated 304L stainless steel exist in the gaseous diffusion plants alone. Other high-value metals available in the DOE complex include copper, nickel, and zirconium. Melt processing for the decontamination of radioactive scrap metal has been the subject of much research. A major driving force for this research has been the possibility of reapplication of RSM, which is often very high-grade material containing large quantities of strategic elements. To date, several different single and multi-step melting processes have been proposed and evaluated for use as decontamination or recycling strategies. Each process offers a unique combination of strengths and weaknesses, and ultimately, no single melt processing scheme is optimum for all applications since processes must be evaluated based on the characteristics of the input feed stream and the desired output. This paper describes various melt decontamination processes and briefly reviews their application in developmental studies, full scale technical demonstrations, and industrial operations.

Schlienger, M.E.; Buckentin, J.M.; Damkroger, B.K.

1997-04-01T23:59:59.000Z

184

Energy Saving Melting and Revert Reduction Technology: Melting Efficiency in Die Casting Operations  

SciTech Connect

This project addressed multiple aspects of the aluminum melting and handling in die casting operations, with the objective of increasing the energy efficiency while improving the quality of the molten metal. The efficiency of melting has always played an important role in the profitability of aluminum die casting operations. Consequently, die casters need to make careful choices in selecting and operating melting equipment and procedures. The capital cost of new melting equipment with higher efficiency can sometimes be recovered relatively fast when it replaces old melting equipment with lower efficiency. Upgrades designed to improve energy efficiency of existing equipment may be well justified. Energy efficiency is however not the only factor in optimizing melting operations. Melt losses and metal quality are also very important. Selection of melting equipment has to take into consideration the specific conditions at the die casting shop such as availability of floor space, average quantity of metal used as well as the ability to supply more metal during peaks in demand. In all these cases, it is essential to make informed decisions based on the best available data.

David Schwam

2012-12-15T23:59:59.000Z

185

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

186

Superconductivity at 35 K in Graphite-Sulfur Composites  

E-Print Network (OSTI)

We report magnetization measurements performed on graphite–sulfur composites which demonstrate a clear superconducting behavior below the critical temperature Tc0 = 35 K. The Meissner-Ochsenfeld effect, screening supercurrents, and magnetization hysteresis loops characteristic of type-II superconductors were measured. The results indicate that the superconductivity occurs in a small sample fraction, possibly related to the sample surface.

R. Ricardo Da Silva; J. H. S. Torres; Y. Kopelevich

2001-01-01T23:59:59.000Z

187

Electrochemical measurements on lightweight composite nickel-graphite battery electrodes  

SciTech Connect

Graphite mat fibers and nickel metal composite electrodes are superior to sintered carbonyl-nickel powder electrodes in nickel-cadmium cells. The composite electrode functions as a thin electrode and can be utilized in nickel-cadmium, nickel-iron, nickel-zinc, and nickel-hydrogen electrochemical systems. 4 refs.

Sutula, R.A.; Crowe, C.R.

1980-12-01T23:59:59.000Z

188

Molecular dynamics simulations of ordered alkane chains physisorbed on graphite  

E-Print Network (OSTI)

Molecular dynamics simulations of ordered alkane chains physisorbed on graphite Reinhard Hentschke molecular axes oriented parallel to the substrate. Here we employ molecular dynamics (MD) simulations to obtain more details on the molecular order and dynamics within the alkane lamellae as a function

Peters, Achim

189

In accounts of seminal neutron research at ORNL's Graphite Reactor,  

E-Print Network (OSTI)

requested permission to set up an X-ray diffractometer he had brought from the University of Chicago for his of the Graphite Reactor. "I was a student at the University of Chicago in 1942 when Enrico Fermi was doing his. 25 Scrooge (OR Playhouse) Nov. 27 Football: UT vs. Kentucky Dec. 4 Fiddler on the Roof Dec. 11 Best

190

Brookhaven Graphite Research Reactor | Environmental Restoration...  

NLE Websites -- All DOE Office Websites (Extended Search)

of multiple structures and systems that were necessary to operate and maintain the reactor. The most recognizable features of the complex include the Building 701 officeshigh...

191

Reduction of Oxidative Melt Loss of Aluminum and Its Alloys  

Science Conference Proceedings (OSTI)

This project led to an improved understanding of the mechanisms of dross formation. The microstructural evolution in industrial dross samples was determined. Results suggested that dross that forms in layers with structure and composition determined by the local magnesium concentration alone. This finding is supported by fundamental studies of molten metal surfaces. X-ray photoelectron spectroscopy data revealed that only magnesium segregates to the molten aluminum alloy surface and reacts to form a growing oxide layer. X-ray diffraction techniques that were using to investigate an oxidizing molten aluminum alloy surface confirmed for the first time that magnesium oxide is the initial crystalline phase that forms during metal oxidation. The analytical techniques developed in this project are now available to investigate other molten metal surfaces. Based on the improved understanding of dross initiation, formation and growth, technology was developed to minimize melt loss. The concept is based on covering the molten metal surface with a reusable physical barrier. Tests in a laboratory-scale reverberatory furnace confirmed the results of bench-scale tests. The main highlights of the work done include: A clear understanding of the kinetics of dross formation and the effect of different alloying elements on dross formation was obtained. It was determined that the dross evolves in similar ways regardless of the aluminum alloy being melted and the results showed that amorphous aluminum nitride forms first, followed by amorphous magnesium oxide and crystalline magnesium oxide in all alloys that contain magnesium. Evaluation of the molten aluminum alloy surface during melting and holding indicated that magnesium oxide is the first crystalline phase to form during oxidation of a clean aluminum alloy surface. Based on dross evaluation and melt tests it became clear that the major contributing factor to aluminum alloy dross was in the alloys with Mg content. Mg was identified as the primary factor that accelerates dross formation specifically in the transition from two phases to three phase growth. Limiting magnesium oxidation on the surface of molten aluminum therefore becomes the key to minimizing melt loss, and technology was developed to prevent magnesium oxidation on the aluminum surface. This resulted in a lot of the work being focused on the control of Mg oxidation. Two potential molten metal covering agents that could inhibit dross formation during melting and holding consisting of boric acid and boron nitride were identified. The latter was discounted by industry as it resulted in Boron pick up by the melt beyond that allowed by specifications during plant trials. The understanding of the kinetics of dross formation by the industry partners helped them understand how temperature, alloy chemistry and furnace atmosphere (burner controls--e.g. excess air) effected dross formation. This enables them to introduce in their plant process changes that reduced unnecessary holding at high temperatures, control burner configurations, reduce door openings to avoid ingress of air and optimize charge mixes to ensure rapid melting and avoid excess oxidation.

Dr. Subodh K. Das; Shridas Ningileri

2006-03-17T23:59:59.000Z

192

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

193

Process for the fabrication of aluminum metallized pyrolytic graphite sputtering targets  

DOE Patents (OSTI)

An improved method for fabricating pyrolytic graphite sputtering targets with superior heat transfer ability, longer life, and maximum energy transmission. Anisotropic pyrolytic graphite is contoured and/or segmented to match the erosion profile of the sputter target and then oriented such that the graphite's high thermal conductivity planes are in maximum contact with a thermally conductive metal backing. The graphite contact surface is metallized, using high rate physical vapor deposition (HRPVD), with an aluminum coating and the thermally conductive metal backing is joined to the metallized graphite target by one of four low-temperature bonding methods; liquid-metal casting, powder metallurgy compaction, eutectic brazing, and laser welding.

Makowiecki, Daniel M. (Livermore, CA); Ramsey, Philip B. (Livermore, CA); Juntz, Robert S. (Hayward, CA)

1995-01-01T23:59:59.000Z

194

Rock melting tool with annealer section  

DOE Patents (OSTI)

A rock melting penetrator is provided with an afterbody that rapidly cools a molten geological structure formed around the melting tip of the penetrator to the glass transition temperature for the surrounding molten glass-like material. An annealing afterbody then cools the glass slowly from the glass transition temperature through the annealing temperature range to form a solid self-supporting glass casing. This allows thermally induced strains to relax by viscous deformations as the molten glass cools and prevents fracturing of the resulting glass liner. The quality of the glass lining is improved, along with its ability to provide a rigid impermeable casing in unstable rock formations.

Bussod, Gilles Y. (Santa Fe, NM); Dick, Aaron J. (Oakland, CA); Cort, George E. (Montrose, CO)

1998-01-01T23:59:59.000Z

195

Surface Melt Area and Water Balance Modeling on the Greenland Ice Sheet 1995–2005  

Science Conference Proceedings (OSTI)

SnowModel, a physically based snow-evolution modeling system that includes four submodels—MicroMet, EnBal, SnowPack, and SnowTran-3D—was used to simulate variations in Greenland [including the Greenland Ice Sheet (GrIS)] surface snow and ice melt,...

Sebastian H. Mernild; Glen E. Liston; Christopher A. Hiemstra; Konrad Steffen

2008-12-01T23:59:59.000Z

196

Appendix F Cultural Resources, Including  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

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

197

A New Look at the Melting Layer  

Science Conference Proceedings (OSTI)

The authors derive a relationship between the vertical Doppler spectrum of the rain just below the radar bright band and that of the snow just above. It neglects vertical air motions and assumes that each snowflake simply melts to form a raindrop ...

Fiona J. Drummond; R. R. Rogers; S. A. Cohn; W. L. Ecklund; D. A. Carter; J. S. Wilson

1996-03-01T23:59:59.000Z

198

GOES Observation of a Rapidly Melting Snowband  

Science Conference Proceedings (OSTI)

GOES observation of rapid dissipation of a 5–10 cm (2–4 inches) depth snowband over the central and upper Mississippi River valley on 15 April 1980 is presented. Differences in the local weather between the stations with and without melting snow ...

Carlyle H. Wash; Delain A. Edman; John Zapotocny

1981-06-01T23:59:59.000Z

199

Silicon purification melting for photovoltaic applications  

DOE Green Energy (OSTI)

The availability of polysilicon feedstock has become a major issue for the photovoltaic (PV) industry in recent years. Most of the current polysilicon feedstock is derived from rejected material from the semiconductor industry. However, the reject material can become scarce and more expensive during periods of expansion in the integrated-circuit industry. Continued rapid expansion of the PV crystalline-silicon industry will eventually require a dedicated supply of polysilicon feedstock to produce solar cells at lower costs. The photovoltaic industry can accept a lower purity polysilicon feedstock (solar-grade) compared to the semiconductor industry. The purity requirements and potential production techniques for solar-grade polysilicon have been reviewed. One interesting process from previous research involves reactive gas blowing of the molten silicon charge. As an example, Dosaj et all reported a reduction of metal and boron impurities from silicon melts using reactive gas blowing with 0{sub 2} and Cl{sub 2}. The same authors later reassessed their data and the literature, and concluded that Cl{sub 2}and 0{sub 2}/Cl{sub 2} gas blowing are only effective for removing Al, Ca, and Mg from the silicon melt. Researchers from Kawasaki Steel Corp. reported removal of B and C from silicon melts using reactive gas blowing with an 0{sub 2}/Ar plasma torch. Processes that purify the silicon melt are believed to be potentially much lower cost compared to present production methods that purify gas species.

VAN DEN AVYLE,JAMES A.; HO,PAULINE; GEE,JAMES M.

2000-04-01T23:59:59.000Z

200

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

Note: This page contains sample records for the topic "melting includes graphite" from the National Library of EnergyBeta (NLEBeta).
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201

A PROPOSAL FOR THE CONTROLLED RELEASE OF STORED ENERGY IN THE MTR REFLECTOR GRAPHITE  

SciTech Connect

A study of the stored energy buildup in the MTR reflector graphite and a program of controlled energy release is presented. Calculations, based on measurements of samples from the pebble zone show that an inadvertent spontaneous stored energy release would cause a temperature rise of 90 deg F in the pebble zone. The maximum transient structure temperatures resulting from a worst credible accidental release of energy would be less than allowable at present (except for possible damage to neutron detector chambers) but could exceed this value in five years. It is proposed that the stored energy be released by thermal annealing. The reflector graphite is heated by reducing the air flow and operating the reactor at low power until a temperature of 500 deg F is reached, at which point the reactor is scrammed. Normal cooling is provlded after 15 minutes at peak anneal temperature or if the temperature rises to 600 deg F. Health physics monitoring includes continuous measurement of particulate and of Ci/sup 4/ activity. Sustained oxidatlon, if it occurs, wlll be detected with a C0/sub 2/ monitor and controlled by smothering. An estimated 2 or 3 days of MTR operating time will be needed of which the anneal itself wlll require about one day. (auth)

Fast, E.; Smith, E.O.; Ford, J.D.

1959-12-09T23:59:59.000Z

202

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

Science Conference Proceedings (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

203

Catalytic graphitization of carbon aerogels by transition metals  

Science Conference Proceedings (OSTI)

Carbon aerogels and Cr-, Fe-, Co-, and Ni-containing carbon aerogels were obtained by pyrolysis, at temperatures between 500 and 1,800 C, of the corresponding aerogels prepared by the sol-gel method from polymerization of resorcinol with formaldehyde. All samples were characterized by mercury porosimetry, nitrogen adsorption, X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), and Raman spectroscopy. Results obtained show that carbon aerogels are, essentially, macroporous materials that maintain large pore volumes even after pyrolysis at 1,800 C. For pyrolysis at temperatures higher than 1,000 C, the presence of the transition metals produced graphitized areas with three-dimensional stacking order, as shown by HRTEM, XRD, and Raman spectroscopy. HRTEM also showed that the metal-carbon containing aerogels were formed by polyhedral structures. Cr and Fe seem to be the best catalysts for graphitization of carbon aerogels.

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

2000-05-02T23:59:59.000Z

204

Destruction of nuclear graphite using closed chamber incineration  

Science Conference Proceedings (OSTI)

Closed chamber incineration (CCI) is a novel technique by which irradiated nuclear graphite may be destroyed without the risk of radioactive cation release into the environment. The process utilizes an enclosed combustion chamber coupled with molten carbonate fuel cells (MCFCs). The transport of cations is intrinsically suppressed by the MCFCs, such that only the combustion gases are conducted through for release to the environment. An example CCI design was developed which had as its goal the destruction of graphite fuel elements from the Fort St. Vrain reactor (FSVR). By employing CCI, the volume of high level waste from the FSVR will be reduced by approximately 87 percent. Additionally, the incineration process will convert the SiC coating on the FSVR fuel particles to SiO{sub 2}, thus creating a form potentially suitable for direct incorporation in a vitrification process stream. The design is compact, efficient, and makes use of currently available technology.

Senor, D.J.; Hollenberg, G.W.; Morgan, W.C. [Pacific Northwest Lab., Richland, WA (United States); Marianowski, L.G. [Institute of Gas Technology, Chicago, IL (United States)

1994-03-01T23:59:59.000Z

205

Testing of Small Graphite Samples for Nuclear Qualification  

Science Conference Proceedings (OSTI)

Accurately determining the mechanical properties of small irradiated samples is crucial to predicting the behavior of the overal irradiated graphite components within a Very High Temperature Reactor. The sample size allowed in a material test reactor, however, is limited, and this poses some difficulties with respect to mechanical testing. In the case of graphite with a larger grain size, a small sample may exhibit characteristics not representative of the bulk material, leading to inaccuracies in the data. A study to determine a potential size effect on the tensile strength was pursued under the Next Generation Nuclear Plant program. It focuses first on optimizing the tensile testing procedure identified in the American Society for Testing and Materials (ASTM) Standard C 781-08. Once the testing procedure was verified, a size effect was assessed by gradually reducing the diameter of the specimens. By monitoring the material response, a size effect was successfully identified.

Julie Chapman

2010-11-01T23:59:59.000Z

206

Method for melting glass by measurement of non-bridging oxygen  

DOE Patents (OSTI)

A method is described 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. 4 figs.

Jantzen, C.M.

1992-04-07T23:59:59.000Z

207

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

208

Behavior of Chlorine-36 and Tritium in Irradiated Graphite Wastes  

Science Conference Proceedings (OSTI)

This report examines the international data on the formation and distribution of 36Cl and 3H in graphite moderators in the context of the treatment and/or disposal of the material upon reactor decommissioning. Organizations in France have made major contributions to work in the field of 36Cl, and the review also considers work from the UK, USA and Ukraine.BackgroundThe Electric Power Research Institute (EPRI) has conducted a ...

2012-11-30T23:59:59.000Z

209

VINYL COATING OF GRAPHITE PLATES FOR ULTRASONIC INSPECTION  

SciTech Connect

A process has been developed for application of a thin, adherent vinyi plastic coating to graphite plates to prevent absorption of coupling fluids'' used in ultrasonic inspection. The plates are preheated and dipped mechanically in a fluid plastisol, and the resulting coating is fused in an infra-red heater. No significant attenuation of ultrasonic impulse results from presence of the coating. After inspection, the vinyl sheath may be easily stripped from the plate. (auth)

Church, J.S.; Bell, J.H. Jr.; Donahoe, J.K.; Faussone, R.A.; Rogers, G.B.; Rowen, J.T.

1958-03-25T23:59:59.000Z

210

First-principles study of Se-intercalated graphite  

DOE Green Energy (OSTI)

Se-intercalated graphite compounds (Se-GICs) are considered as promising candidates for room-temperature thermoelectric cooling devices. Here the authors analyze the crystallographic structure and electronic properties of these materials within the framework of density-functional theory. First, the Adaptive-Coordinate Real-space Electronic Structure (ACRES) code is used to determine the stable structure of a representative stage-2 Se-GIC by relaxing atomic positions. The stable configuration is found to be a pendant-type structure, in which each selenium is bonded covalently to two atoms within the same carbon layer, causing a local distortion of the in-plane conjugation of the graphite. Then, they use the full potential linearized augmented plane wave (FP-LAPW) method to calculate the electronic band structure of the material and discuss its properties. Near the Fermi energy E{sub F}, there are wide bands originating from the host graphitic electronic structure and a few very narrow bands mainly of Se 4p character. The latter bands contribute to high peaks in the density of states close to E{sub F}. They show that this feature, although typical of many good thermoelectrics, does not necessarily imply high thermopower in the case of Se-GICs.

BARTKOWIAK,M.; MODINE,NORMAND A.; SOFO,J.O.; MAHAN,G.D.

2000-05-11T23:59:59.000Z

211

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

212

Experimental studies of melting and crystallization processes in planetary interiors  

E-Print Network (OSTI)

Melting and crystallization processes on the Earth and Moon are explored in this thesis, and the topics of melt generation, transport, and crystallization are discussed in three distinct geologic environments: the Moon's ...

Krawczynski, Michael James

2011-01-01T23:59:59.000Z

213

Nuclear reactor melt-retention structure to mitigate direct containment heating  

DOE Patents (OSTI)

A light water nuclear reactor melt-retention structure to mitigate the extent of direct containment heating of the reactor containment building. The structure includes a retention chamber for retaining molten core material away from the upper regions of the reactor containment building when a severe accident causes the bottom of the pressure vessel of the reactor to fail and discharge such molten material under high pressure through the reactor cavity into the retention chamber. In combination with the melt-retention chamber there is provided a passageway that includes molten core droplet deflector vanes and has gas vent means in its upper surface, which means are operable to deflect molten core droplets into the retention chamber while allowing high pressure steam and gases to be vented into the upper regions of the containment building. A plurality of platforms are mounted within the passageway and the melt-retention structure to direct the flow of molten core material and help retain it within the melt-retention chamber. In addition, ribs are mounted at spaced positions on the floor of the melt-retention chamber, and grid means are positioned at the entrance side of the retention chamber. The grid means develop gas back pressure that helps separate the molten core droplets from discharged high pressure steam and gases, thereby forcing the steam and gases to vent into the upper regions of the reactor containment building.

Tutu, Narinder K. (Manorville, NY); Ginsberg, Theodore (East Setauket, NY); Klages, John R. (Mattituck, NY)

1991-01-01T23:59:59.000Z

214

Process Mapping of Melt Pool Dimension Control in Electron Beam ...  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, Materials Science & Technology 2011. Symposium, Additive Manufacturing of Metals. Presentation Title, Process Mapping of Melt ...

215

Microstructure of Titanium Alloy Prepared by Selective Laser Melting ...  

Science Conference Proceedings (OSTI)

Symposium, Solidification in Additive Manufacturing. Presentation Title, Microstructure of Titanium Alloy Prepared by Selective Laser Melting in Vacuum.

216

Microwave Absorption Measurements of Melting Spherical and Nonspherical Hydrometeors  

Science Conference Proceedings (OSTI)

Measurements were made of the absorption behavior of melting and freezing hydrometeors using resonant cavity perturbation techniques at a wavelength of 2.82 cm. Melting ice spheres with equivalent melted diameters between 1.15 and 2.00 mm exhibit ...

Robert John Hansman Jr.

1986-08-01T23:59:59.000Z

217

Process for the fabrication of aluminum metallized pyrolytic graphite sputtering targets  

DOE Patents (OSTI)

An improved method is disclosed for fabricating pyrolytic graphite sputtering targets with superior heat transfer ability, longer life, and maximum energy transmission. Anisotropic pyrolytic graphite is contoured and/or segmented to match the erosion profile of the sputter target and then oriented such that the graphite`s high thermal conductivity planes are in maximum contact with a thermally conductive metal backing. The graphite contact surface is metallized, using high rate physical vapor deposition (HRPVD), with an aluminum coating and the thermally conductive metal backing is joined to the metallized graphite target by one of four low-temperature bonding methods; liquid-metal casting, powder metallurgy compaction, eutectic brazing, and laser welding. 11 figs.

Makowiecki, D.M.; Ramsey, P.B.; Juntz, R.S.

1995-07-04T23:59:59.000Z

218

OECD MCCI project Melt Eruption Test (MET) design report, Rev. 2. April 15, 2003.  

SciTech Connect

The Melt Attack and Coolability Experiments (MACE) program at Argonne National Laboratory addressed the issue of the ability of water to cool and thermally stabilize a molten core-concrete interaction when the reactants are flooded from above. These tests provided data regarding the nature of corium interactions with concrete, the heat transfer rates from the melt to the overlying water pool, and the role of noncondensable gases in the mixing processes that contribute to melt quenching. The Melt Coolability and Concrete Interaction (MCCI) program is pursuing separate effect tests to examine the viability of the melt coolability mechanisms identified as part of the MACE program. These mechanisms include bulk cooling, water ingression, volcanic eruptions, and crust breach. At the second PRG meeting held at ANL on 22-23 October 2002, a preliminary design1 for a separate effects test to investigate the melt eruption cooling mechanism was presented for PRG review. At this meeting, NUPEC made several recommendations on the experiment approach aimed at optimizing the chances of achieving a floating crust boundary condition in this test. The principal recommendation was to incorporate a mortar sidewall liner into the test design, since data from the COTELS experiment program indicates that corium does not form a strong mechanical bond with this material. Other recommendations included: (i) reduction of the electrode elevation to well below the melt upper surface elevation (since the crust may bond to these solid surfaces), and (ii) favorably taper the mortar liner to facilitate crust detachment and relocation during the experiment. Finally, as a precursor to implementing these modifications, the PRG recommended the development of a design for a small-scale scoping test intended to verify the ability of the mortar liner to preclude formation of an anchored bridge crust under core-concrete interaction conditions. This revised Melt Eruption Test (MET) plan is intended to satisfy these PRG recommendations. Specifically, the revised plan focuses on providing data on the extent of crust growth and melt eruptions as a function of gas sparging rate under well-controlled experiment conditions, including a floating crust boundary condition. The overall objective of MET is to determine to what extent core debris is rendered coolable by eruptive-type processes that breach the crust that rests upon the melt. The specific objectives of this test are as follows: (1) Evaluate the augmentation in surface heat flux during periods of melt eruption; (2) Evaluate the melt entrainment coefficient from the heat flux and gas flow rate data for input into models that calculate ex-vessel debris coolability; (3) Characterize the morphology and coolability of debris resulting from eruptive processes that transport melt into overlying water; and (4) Discriminate between periods when eruptions take the form of particle ejections into overlying water, leading to a porous particle bed, and single-phase extrusions, which lead to volcano-type structures.

Farmer, M. T.; Lomperski, S.; Kilsdonk, D. J.; Aeschlimann, R. W.; Basu, S. (Nuclear Engineering Division); (NRC)

2011-05-23T23:59:59.000Z

219

Observations of Nuclear Explosive Melt Glass Textures and Surface Areas  

Science Conference Proceedings (OSTI)

This memo report summarizes our current knowledge of the appearance of melt glass formed and subsequently deposited in the subsurface after an underground nuclear test. We have collected archived pictures and melt glass samples from a variety of underground nuclear tests that were conducted at the Nevada Test Site (NTS) during the U.S. nuclear testing program. The purpose of our work is to better determine the actual variation in texture and surface area of the melt glass material. This study is motivated by our need to better determine the rate at which the radionuclides incorporated in the melt glass are released into the subsurface under saturated and partially saturated conditions. The rate at which radionuclides are released from the glass is controlled by the dissolution rate of the glass. Glass dissolution, in turn, is a strong function of surface area, glass composition, water temperature and water chemistry (Bourcier, 1994). This work feeds into an ongoing experimental effort to measure the change in surface area of analog glasses as a function of dissolution rate. The conclusions drawn from this study help bound the variation in the textures of analog glass samples needed for the experimental studies. The experimental work is a collaboration between Desert Research Institute (DRI) and Earth and Environmental Sciences-Lawrence Livermore National Laboratory (EES-LLNL). On March 4, 1999 we hosted a meeting at LLNL to present and discuss our findings. The names of the attendees appear at the end of this memo. This memo report further serves to outline and summarize the conclusions drawn from our meeting. The United States detonated over 800 underground nuclear tests at the NTS between 1951 and 1992. In an effort to evaluate the performance of the nuclear tests, drill-back operations were carried out to retrieve samples of rock in the vicinity of the nuclear test. Drill-back samples were sent to Los Alamos National Laboratory (LANL) and Lawrence Livermore National Laboratory (LLNL) and analyzed for diagnostic purposes. As a result of these activities, a body of knowledge consisting of personal accounts, photos, reports and archived solid samples was gained regarding the physical nature of the melt glass that formed during an underground nuclear test. In this memo report, we summarize previously published reports, compile archived photos, document and describe melt glass samples and summarized discussions from former field engineers and radiochemists who had direct knowledge of drill-back samples. All the information presented in the report was gathered from unclassified sources. We have included as wide a variation of samples as we could document. Unfortunately, as part of the drill-back and diagnostic efforts, it was not common practice to photograph or physically describe the material returned to the surface.

Kersting, A B; Smith, D K

2006-01-17T23:59:59.000Z

220

A NONLINEAR TWO-PHASE STEFAN PROBLEM WITH MELTING POINT GRADIENT  

E-Print Network (OSTI)

A NONLINEAR TWO-PHASE STEFAN PROBLEM WITH MELTING POINT GRADIENT: A CONSTRUCTIVE APPROACH D. D. Ang-dimensional two-phase Stefan problem, modeling a layer of solid material floating on liquid. The model includes of a cake of ice floating in water after the surface of the ice has received a fresh snowfall

Keinert, Fritz

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

Wettability of Liquid Aluminum on Carbon/Graphite/TiB2 Composite ...  

Science Conference Proceedings (OSTI)

Presentation Title, Wettability of Liquid Aluminum on Carbon/Graphite/TiB2 ... The Applicability of Carbon Capture and Sequestration in Primary Aluminium ...

222

Method of fabricating graphite for use as a skeletal prosthesis and product thereof  

DOE Patents (OSTI)

A method for producing porous graphite for use as bone replacement with a structure for osteon penetration. Graphite is produced with ordered circular pores of 100 to 1000 microns in diameter covering at least 25% of the exposed surfaces. A cylindrical fiber is coated with a carbon flour-pitch mix and is then wound on a bobbin in a predetermined manner. The product of winding is dried, pressed, carbonized, and then graphitized. The fibers are removed either chemically or by volatilization during carbonization or graphitization.

Eatherly, Walter P. (Oak Ridge, TN); Robbins, J. M. (Oak Ridge, TN); Rosson, Sr., David E. (Oak Ridge, TN)

1978-01-01T23:59:59.000Z

223

Decontamination of metals by melt refinings/slagging: An annotated bibliography  

Science Conference Proceedings (OSTI)

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 storage problems, Westinghouse Idaho Nuclear Company (WINCO) 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 scale 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--500 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. This report is the result of the literature search conducted to establish a basis for experimental melt/slag program development.

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

1993-07-01T23:59:59.000Z

224

Decontamination of metals by melt refining/slagging: First year progress report  

SciTech Connect

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 storage problems, Westinghouse Idaho Nuclear Company (WINCO) 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 technologies for the recycling of stainless steel RSM. The scope of the Montana Tech program includes a literature survey, a decontaminating slag design study, small scale melting studies to determine optimum slag compositions for removal of radioactive contaminant surrogates, analysis of preferred melting techniques, and coordination of pilot scale melting demonstrations (100-500 lbs) to be conducted at selected commercial facilities. This program will identify methods that can be used to recycle stainless steel RSM which will be used to fabricate high and low level waste canisters for the Idaho Waste Immobilization Facility. This report summarizes the results of an extensive literature review and the first year`s progress on slag design, small-scale melt refining of surrogate-containing stainless steel (presently only a three month effort), and pilot-scale preparation of surrogate master ingots.

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

1994-03-01T23:59:59.000Z

225

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

Science Conference Proceedings (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

226

Swirling Melting Characteristics of Fly Ashes from Co-Firing of MSWI in China  

Science Conference Proceedings (OSTI)

Melting treatment is an efficient for heavy metal stabilization in MSW fly ash. The fly ashes from co-firing of municipal solid waste and coal incinerator were melted in the swirling melting furnace system under various temperatures. The melting characteristics ... Keywords: fly ash, co-firing, melting, melting temperature, heavy metals, fixation rate

Wang Xue-tao; Jiao You-zhou; Xu Bin; Jin Bao-sheng

2009-10-01T23:59:59.000Z

227

Electronic structure of graphite/6H-SiC interfaces  

E-Print Network (OSTI)

Abstract. We have studied the electronic structure of the interface between 6H-SiC{0001} and graphite. On n-type and p-type 6H-SiC(0001) we observe Schottky barriers of ?Si b,n = 0.3±0.1 eV and ?Si b,p = 2.7±0.1 eV, respectively. The observed barrier is face specific: on n-type 6H-SiC(0001) we find ?C b,n = 1.3±0.1 eV. The impact of these barriers on the electrical properties of metal/SiC contacts is discussed.

Th. Seyller; K. V. Emtsev; F. Speck; K. -y. Gao; L. Ley

2006-01-01T23:59:59.000Z

228

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

229

Molecular Dynamics Simulation of Collisions between Hydrogen and Graphite  

E-Print Network (OSTI)

Abstract. Hydrogen adsorption by graphite is examined by classical molecular dynamics simulation using a modified Brenner REBO potential. Such interactions are typical in chemical sputtering experiments, and knowledge of the fundamental behavior of hydrogen and graphene in collisional conditions is essential for modeling the sputtering mechanism. The hydrogen adsorption rate is found to be dependent on the incident hydrogen energy and not on graphene temperature. Rather than destroying the graphene, hydrogen incidence at energies of less than 100 eV can be classified into three regimes of adsorption, reflection and penetration through one or more graphene layers. Incidence at the lowest energies is shown to distort the graphene structure. 1.

unknown authors

2005-01-01T23:59:59.000Z

230

Optical and electronic properties of two dimensional graphitic silicon carbide  

E-Print Network (OSTI)

Optical and electronic properties of two dimensional few layers graphitic silicon carbide (GSiC), in particular monolayer and bilayer, are investigated by density functional theory and found different from that of graphene and silicene. Monolayer GSiC has direct bandgap while few layers exhibit indirect bandgap. The bandgap of monolayer GSiC can be tuned by an in-plane strain. Properties of bilayer GSiC are extremely sensitive to the interlayer distance. These predictions promise that monolayer GSiC could be a remarkable candidate for novel type of light-emitting diodes utilizing its unique optical properties distinct from graphene, silicene and few layers GSiC.

Lin, Xiao; Lin, Shisheng; Hakro, Ayaz Ali; Cao, Te; Chen, Hongsheng; Zhang, Baile

2012-01-01T23:59:59.000Z

231

Prerequisite requirements for higher graphite temperature limits and/or nitrogen atmosphere at all reactors  

SciTech Connect

The graphite temperature limits specified in the process standards-are being closely approached or have limited power levels at B, D, DR, and reactors. An increase of approximately 50--100 C in graphite temperature limits at these reactors would permit year-around operation on bulk outlet temperature limits. There has been considerable recent interest in extending to all reactors the use of nitrogen as a reactor gas constituent. With present graphite temperature limits, significant benefit from nitrogen usage will not be obtained during the winter months at reactors which are graphite temperature limited with approximately 100 per cent helium. However, during the summer months when bulk outlet temperature limitations result in graphite temperatures considerably below the maximum permissible graphite temperatures, the substitution of nitrogen for carbon dioxide could be of value. Under these circumstances, both a reduction in helium usage and a reduction in enrichment costs could result. With an increase in permissible graphite temperature limits, year-around benefit from reduced helium usage and reduced enrichment costs would be possible. To meet the Pu-240 specification with higher graphite temperatures however, would require a reduction in current goal discharge exposures with resulting increased fuel and burnout costs. Additionally, the incentives for higher graphite temperatures are very sensitive to both the mode of operation and to the assumed product worth. An economic study by the Process Analysis Unit discussing in detail the factors influencing the incentive for higher graphite temperature will be published in the near future. At a meeting among the staff several weeks ago, the prerequisite requirements for permitting higher graphite temperatures and/or nitrogen usage at all reactors were discussed. It is the purpose of this letter to briefly outline the prerequisite steps considered necessary to achieve these goals.

Graves, S.M.

1962-02-26T23:59:59.000Z

232

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

Science Conference Proceedings (OSTI)

In order to form the stable surface film and to further enhance the long-term cycling stability of the graphite anodes of lithium-ion batteries, the surface of graphite powders has been modified by AlF3 coating through chemical precipitation method. The AlF3-coated graphite shows no evident changes in the bulk structure and a thin AlF3-coating layer of about 2 nm thick is found to uniformly cover the graphite particles with 2 wt% AlF3 content. However, it delivers a higher initial discharge capacity and largely improved rate performances compared to the pristine graphite. Remarkably, AlF3 coated graphite demonstrated a much better cycle life. After 300 cycles, AlF3 coated graphite and uncoated graphite show capacity retention of 92% and 81%, respectively. XPS measurement shows that a more conductive solid electrode interface (SEI) layer was formed on AlF3 coated graphite as compared to uncoated graphite. SEM monograph also reveals that the AlF3-coated graphite particles have a much more stable surface morphology after long-term cycling. Therefore, the improved electrochemical performance of AlF3 coated graphite can be attributed to a more stable and conductive SEI formed on coated graphite anode during cycling process.

Ding, Fei; Xu, Wu; Choi, Daiwon; Wang, Wei; Li, Xiaolin; Engelhard, Mark H.; Chen, Xilin; Yang, Zhenguo; Zhang, Jiguang

2012-04-27T23:59:59.000Z

233

Estimation procedures and error analysis for inferring the total plutonium (Pu) produced by a graphite-moderated reactor  

Science Conference Proceedings (OSTI)

Graphite isotope ratio method (GIRM) is a technique that uses measurements and computer models to estimate total plutonium (Pu) production in a graphite-moderated reactor. First, isotopic ratios of trace elements in extracted graphite samples from the target reactor are measured. Then, computer models of the reactor relate those ratios to Pu production. Because Pu is controlled under nonproliferation agreements, an estimate of total Pu production is often required, and a declaration of total Pu might need to be verified through GIRM. In some cases, reactor information (such as core dimensions, coolant details, and operating history) are so well documented that computer models can predict total Pu production without the need for measurements. However, in most cases, reactor information is imperfectly known, so a measurement and model-based method such as GIRM is essential. Here, we focus on GIRM’s estimation procedure and its associated uncertainty. We illustrate a simulation strategy for a specific reactor that estimates GIRM’s uncertainty and determines which inputs contribute most to GIRM’s uncertainty, including inputs to the computer models. These models include a ‘‘local’’ code that relates isotopic ratios to the local Pu production, and a ‘‘global’’ code that predicts the Pu production shape over the entire reactor. This predicted shape is included with other 3D basis functions to provide a ‘‘hybrid basis set’’ that is used to fit the local Pu production estimates. The fitted shape can then be integrated over the entire reactor to estimate total Pu production. This GIRM evaluation provides a good example of several techniques of uncertainty analysis and introduces new reasons to fit a function using basis functions in the evaluation of the impact of uncertainty in the true 3D shape.

Heasler, Patrick G.; Burr, Tom; Reid, Bruce D.; Gesh, Christopher J.; Bayne, Charles K.

2006-10-01T23:59:59.000Z

234

MELTING AND FORMING OF SER FUEL RODS  

SciTech Connect

Sixty-one metal alloy reds were fabricated for the SNAP Experimental Reactor (SER), a compact nuclear power source. These rads were 1 in. in diameter by 10 in. long and consisted of an alloy containing 7 wt.% highly enriched uranium and 93 wt.% zinconium. Melting of the alloy was done by generally accepted consumable-arc meltiag techniques. Extrusion of alloy slugs into rods was carried out, unclad, at 850 deg F. Suitable controls were developed to insure uniformity of products and reproducibility of batches. The procedures developed for this application are considered adequate for future requirements. (auth)

Drennan, P.S.

1960-10-01T23:59:59.000Z

235

TENSILE PROPERTIES OF PYROLYTIC GRAPHITE TO 5000 F  

SciTech Connect

Tensile properties of pyrolytic graphite were measured parallel to the basal planes from room temperature to 5000 deg F. The gage section of the test specimen was 0.06 by 0.10 in. in cross section and3/4-in. long. The specimens were heated in a helium atmosphere by an external graphite heater and were tested at a strain rate of approx 2 x 10/sup -//sup 4/ in./in./sec. Tensile strengths at room temperatare varied from 6,000 to 19,000 psi with elongations of less thsn 1%. At 3000 deg F the strength and elongation were approximately the same as at room temperature. At 4000 deg F there was a very slight increase in the strength and elongation. At 4500 deg F tensile strengths to 35,000 psi and elongations up to 3%, and at 5000"F tensile strengths of 64,000 psi and elongations greater than 70% were measured. At 4500 deg F and above load-deformation curves were recorded. Microstructure and x-ray diffraction patterns showed that marked structural changes accompsny deformation at 5000 deg F. Large changes in room-temperature dimensions, parallel and perpendicular to the basal planes, were measured after heating, with no load, to temperatures in this same range. (auth)

Kotlensky, W.V.; Martens, H.E.

1961-03-10T23:59:59.000Z

236

Benchmarking of Graphite Reflected Critical Assemblies of UO2  

Science Conference Proceedings (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

237

Characteristics of graphene FET directly transformed from a resist pattern through interfacial graphitization of liquid gallium  

Science Conference Proceedings (OSTI)

We found that an extremely thin resist pattern on silicon dioxide can be directly transformed into a graphene field effect transistor (FET) channel via interfacial graphitization of liquid gallium. These patterned graphene FETs have p-type characteristics ... Keywords: Conductance, FET, Gallium, Graphene, Graphitization, Resist, Solid phase reaction

Jun-ichi Fujita; Ryuichi Ueki; Takuya Nishijima; Yosuke Miyazawa

2011-08-01T23:59:59.000Z

238

Chemical sputtering of ATJ graphite induced by low-energy D  

E-Print Network (OSTI)

Chemical sputtering of ATJ graphite induced by low-energy DĂľ 2 bombardment L.I. Vergara *, F Received 15 June 2005; accepted 4 August 2005 Abstract Results of chemical sputtering of ATJ graphite thermonuclear fusion reactor devices. Chemical and physical sputtering processes, which occur when thermal

239

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

240

Effect of the graphite electrode material on the characteristics of molten salt electrolytically produced carbon nanomaterials  

SciTech Connect

The electrochemical erosion of a graphite cathode during the electrolysis of molten lithium chloride salt may be used for the preparation of nano-structured carbon materials. It has been found that the structures and morphologies of these carbon nanomaterials are dependent on those of the graphite cathodes employed. A combination of tubular and spherical carbon nanostructures has been produced from a graphite with a microstructure of predominantly planar micro-sized grains and a minor fraction of more irregular nano-sized grains, whilst only spherical carbon nanostructures have been produced from a graphite with a microstructure of primarily nano-sized grains. Based on the experimental results, a best-fit regression equation is proposed that relates the crystalline domain size of the graphite reactants and the carbon products. The carbon nanomaterials prepared possess a fairly uniform mesoporosity with a sharp peak in pore size distribution at around 4 nm. The results are of crucial importance to the production of carbon nanomaterials by way of the molten salt electrolytic method. - Highlights: {yields} Carbon nanomaterials are synthesised by LiCl electrolysis with graphite electrodes. {yields} The degree of crystallinity of graphite reactant and carbon product are related. {yields} A graphite reactant is identified that enables the preparation of carbon nanotubes. {yields} The carbon products possess uniform mesoporosity with narrow pore size distribution.

Kamali, Ali Reza, E-mail: ark42@cam.ac.uk; Schwandt, Carsten; Fray, Derek J.

2011-10-15T23:59:59.000Z

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.


241

Pore-width-dependent preferential interaction of sp2carbon atoms in cyclohexene with graphitic slit pores by GCMC simulation  

Science Conference Proceedings (OSTI)

The adsorption of cyclohexene with two sp2 and four sp3 carbon atoms in graphitic slit pores was studied by performing grand canonical Monte Carlo simulation. The molecular arrangement of the cyclohexene on the graphitic carbon ...

Natsuko Kojima; Tomonori Ohba; Yasuhiko Urabe; Hirofumi Kanoh; Katsumi Kaneko

2011-01-01T23:59:59.000Z

242

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

243

Experimental Validation of Stratified Flow Phenomena, Graphite Oxidation, and Mitigation Strategies of Air Ingress Accidents  

Science Conference Proceedings (OSTI)

The US Department of Energy is performing research and development (R&D) that focuses on key phenomena that are important during challenging scenarios that may occur in the Next Generation Nuclear Plant (NGNP) Program / GEN-IV Very High Temperature Reactor (VHTR). Phenomena identification and ranking studies (PIRT) to date have identified the air ingress event, following on the heels of a VHTR depressurization, as very important (Schultz et al., 2006). Consequently, the development of advanced air ingress-related models and verification and validation (V&V) are very high priority for the NGNP program. Following a loss of coolant and system depressurization, air will enter the core through the break. Air ingress leads to oxidation of the in-core graphite structure and fuel. The oxidation will accelerate heat-up of the bottom reflector and the reactor core and will cause the release of fission products eventually. The potential collapse of the bottom reflector because of burn-off and the release of CO lead to serious safety problems. For estimation of the proper safety margin we need experimental data and tools, including accurate multi-dimensional thermal-hydraulic and reactor physics models, a burn-off model, and a fracture model. We also need to develop effective strategies to mitigate the effects of oxidation. The results from this research will provide crucial inputs to the INL NGNP/VHTR Methods R&D project. This project is focused on (a) analytical and experimental study of air ingress caused by density-driven, stratified, countercurrent flow, (b) advanced graphite oxidation experiments, (c) experimental study of burn-off in the bottom reflector, (d) structural tests of the burnt-off bottom reflector, (e) implementation of advanced models developed during the previous tasks into the GAMMA code, (f) full air ingress and oxidation mitigation analyses, (g) development of core neutronic models, (h) coupling of the core neutronic and thermal hydraulic models, and (i) verification and validation of the coupled models.

Chang Ho Oh; Eung Soo Kim; Hee Cheon No; Nam Zin Cho

2008-12-01T23:59:59.000Z

244

Rapid excavation by rock melting (LASL Subterrene Program). Status report, September 1973--June 1976  

DOE Green Energy (OSTI)

Research was directed at establishing the technical and economic feasibility of excavation systems based upon the rock-melting (Subterrene) concept. A series of electrically powered, small-diameter prototype melting penetrators was developed and tested. Research activities include optimizing penetrator configurations, designing high-performance heater systems, and improving refractory metals technology. The properties of the glass linings that are automatically formed on the melted holes have been investigated for a variety of rocks and soils. Thermal and fluid-mechanics analyses of the melt flows were conducted with the objective of optimizing penetrator designs. Field tests and demonstrations of the prototype devices continue to be performed in a wide range of rock and soil types. Primary emphasis was placed on the development of a penetrator designed for more economical extraction of geothermal energy and of small-diameter penetrators which can be utilized in support of geothermal energy exploration programs. Optimization of well design, the trade-off of advance rate with operating life, the advantages of using the melt-glass hole casing for well-bore seal-off, rig automation, and the benefits which result from the insensitivity of rock melting to formation temperatures and geologic variations were also studied. Subsystem hardware development was directed toward resolution of critical technical questions related to penetrators for dense rock, debris handling, electrical heater configuration, and establishing penetrator life. Laboratory experiments and field tests provide data for final system design optimizations and indicate proof of applicability of the concept to a geothermal well hole-forming system. A field test unit to form relatively shallow vertical holes for heat flow surveys in support of geothermal exploration studies has been designed, fabricated, and field tested.

Hanold, R.J. (comp.)

1977-02-01T23:59:59.000Z

245

STORED ENERGY: GROWTH AND ANNEALING STATUS OF GRAPHITE MODERATOR IN THE BNL RESEARCH REACTOR. Final Report  

SciTech Connect

The present sthtus, past annealing procedures and experiences, future annealing procedures, annealing sehedule, revised annealing procedure (1958), procedure for combating a graphite fire in fuel channel, high-temperature stored energy, and graphite burning experiments are reportcd for the BNL Research Reactor. The following subjccts are discussed in the appendixes: control of radiation damage in a graphitc reactor; annealing of graphite moderator structure in the BNL; annealing operation in BNL graphite reactor; effect of pile radiation on mechanical and other properties of graphite; neutron sensing instrumentation; instrumentation for sensing fuel failures; thermocouple pattern for enriched fuel loading; environmental hazard from a molten fuel element; retention of volatile flssion products on filters; retention of volatile fission products on water tube coolers; retention of volatile fission products in molten fuel plates; and release of the lowtemperature stored energy in the BEPO Pile. (W.L.H.)

1959-10-31T23:59:59.000Z

246

Relation between measurable and principal characteristics of radiation-induced shape-change of graphite  

E-Print Network (OSTI)

On the basis of studies of radiation-induced shape-change of reactor graphite GR-280, through the series of measurements of samples with different orientation of cutting with respect to the direction of extrusion, a conclusion is made about the existence of polycrystal substructural elements - domains. Domains, like graphite as a whole, possess the property of transverse isotropy, but have different amplitudes of shape-change and random orientations of the axes of axial symmetry. The model of graphite, constructed on the basis of the concept of domains allowed to explain from a unified point of view most of existing experimental data. It is shown that the presence of the disoriented domain structure leads to the development of radiation-induced stresses and to the dependence of the shape-change on the size of graphite samples. We derive the relation between the shape-change of finite size samples and the actual shape-change of macro-graphite.

M. V. Arjakov; A. V. Subbotin; S. V. Panyukov; O. V. Ivanov; A. S. Pokrovskii; D. V. Kharkov

2011-04-12T23:59:59.000Z

247

Shallow Melt Apparatus for Semicontinuous Czochralski Crystal Growth  

DOE Patents (OSTI)

In a single crystal pulling apparatus for providing a Czochralski crystal growth process, the improvement of a shallow melt crucible (20) to eliminate the necessity supplying a large quantity of feed stock materials that had to be preloaded in a deep crucible to grow a large ingot, comprising a gas tight container a crucible with a deepened periphery (25) to prevent snapping of a shallow melt and reduce turbulent melt convection; source supply means for adding source material to the semiconductor melt; a double barrier (23) to minimize heat transfer between the deepened periphery (25) and the shallow melt in the growth compartment; offset holes (24) in the double barrier (23) to increase melt travel length between the deepened periphery (25) and the shallow growth compartment; and the interface heater/heat sink (22) to control the interface shape and crystal growth rate.

Wang, T.; Ciszek, T. F.

2006-01-10T23:59:59.000Z

248

Evolution of shear-induced melting in dusty plasma  

E-Print Network (OSTI)

The spatiotemporal development of melting is studied experimentally in a 2D dusty plasma suspension. Starting with an ordered lattice, and then suddenly applying localized shear, a pair of counter-propagating flow regions develop. A transition between two melting stages is observed before a steady state is reached. Melting spreads with a front that propagates at the transverse sound speed. Unexpectedly, coherent longitudinal waves are excited in the flow region.

Yan Feng; J. Goree; Bin Liu

2010-04-05T23:59:59.000Z

249

Molecular Dynamics Simulation on the Surface Melting and ...  

Science Conference Proceedings (OSTI)

Abstract Scope, Thermal and non-thermal ultra-fast laser induced surface melting and nanojoining of Ag nanoparticles and nanowires were investigated ...

250

Melting and Refining Technology of High-Temperature Steels and ...  

Science Conference Proceedings (OSTI)

n outlook into the future position of the various melting and .... Inert Gas carburization. Continuous Casting. In Reactor Vessel: - Inert Gas a Arc Remelting (PAR).

251

Energy Efficient Operation of Secondary Aluminum Melting Furnaces  

Science Conference Proceedings (OSTI)

Jun 1, 2007 ... Energy Efficient Operation of Secondary Aluminum Melting Furnaces by P.E. King, J.J. Hatem, and B.M. Golchert ...

252

Production and Handling Slide 21: Melting Points of Uranium and...  

NLE Websites -- All DOE Office Websites (Extended Search)

Points of Uranium and Uranium Compounds Skip Presentation Navigation First Slide Previous Slide Next Slide Last Presentation Table of Contents Melting Points of Uranium and Uranium...

253

The Present Status of Melting Technology for Alloy 718  

Science Conference Proceedings (OSTI)

the section. The availability of such larger pieceweights in Alloy. 718 could quite. CONCLUSION. Over the long development of melting techniques for Alloy 718,.

254

Transient Melt Pool Response in Wire Feed Electron Beam Direct ...  

Science Conference Proceedings (OSTI)

Presentation Title, Transient Melt Pool Response in Wire Feed Electron Beam Direct ... Abstract Scope, Wire feed electron beam direct digital manufacturing ...

255

Melt Processed Crystalline Ceramic Wasteforms for an Advanced ...  

Science Conference Proceedings (OSTI)

Presentation Title, Melt Processed Crystalline Ceramic Wasteforms for an Advanced Nuclear Fuel Cycle. Author(s), Kyle S Brinkman, Jake Amoroso, Kevin Fox, ...

256

PDF PRIMER: Secondary Melting Processes for Superalloys - TMS  

Science Conference Proceedings (OSTI)

Feb 9, 2007 ... Secondary melting of superalloy stock is required to improve chemical homogeneity and reduce levels of inclusions. This primer describes the ...

257

Crystal-melt interfacial Properties of HCP Metals by Molecular ...  

Science Conference Proceedings (OSTI)

Abstract Scope, Crystal-melt interfacial properties were studied by molecular dynamics simulations using different MEAM and EAM interatomic potentials for Mg, ...

258

The Effects of Withdrawal and Melt Overheating Histories on the ...  

Science Conference Proceedings (OSTI)

Roger C. Reed, Kenneth A. Green, Pierre Caron, Timothy P. Gabb, Michael G. Fahrmann, Eric ..... of physical or chemical properties of the melt, such as diffusive.

259

A15: Relation between Melting and Hydrogen Desorption ...  

Science Conference Proceedings (OSTI)

Abstract Scope, In this study, we investigated the melting temperatures and hydrogen desorption properties of LiBH4-NaBH4 mixtures with various compositions, ...

260

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

SciTech Connect

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

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

THE SODIUM GRAPHITE REACTOR POWER PLANT FOR CPPD  

SciTech Connect

The plant arrangement, component design, and the functions of various systems are described and illustrated. Relative estimated costs of the systems and major components are indicated. The reactor core is designed around requiremouts for 254 thermal megawatts, 950 deg F maximum sodium temperature, stainless steel clad graphite moderator blocks, and low enrichment (0.015 to 0.04 U/sup 235/) uranium fuel elements. The fuel cycle is described for the possible fuel elements. The fuel cost factors are discussed. Burn-up limitations encountered for metallic fuel in the SGR temperature range indicate UO/sub 2/ the more desirable choice. The estimated cost of electrical energy associated with the UO/sub 2/ fuel is given. (auth)

Olson, R.L.; Gerber, R.C.; Gordon, R.B.; Ross-Clunis, H.A.; Stolz, J.F.

1958-10-31T23:59:59.000Z

262

CORE PARAMETER STUDY FOR A 300-MW SODIUM GRAPHITE REACTOR  

SciTech Connect

A core parameter study of the operating costs was performed for a 300- Mwe sodium graphite reactor, a scale-up of the Hallam Power Reactor. The results of the study indicate that the core design is nsar optimum and that core modifications would reduce the power costs by less than 5%. The lattice spacing, fuel rod diameter, and sodium flow can be varied within a rather broad range without significant changes in power generation costs. The effect of the fuel cladning thickness is more significant; fuel cycle costs can be reduced if stainless steel canning is replaced with zirconium canning. Use of UC in place of uraniummolybdenum fuel would also permit cost reductions. (D.L.C.)

Corcoran, W.P.

1959-10-22T23:59:59.000Z

263

Rapid excavation by rock melting. LASL subterrene program, December 31, 1972--September 1, 1973  

SciTech Connect

Research is continuing on establishing the technical and economic feasibility of excavation systems based upon the rockmelting (Subterrene) concept. A series of electrically powered, small-diameter prototype melting penetrators have been developed and tested. Research activities include optimizing penetrator configurations, designing high-performance heater systems, and improving refractory-metals technology. The properties of the glass linings that are automatically formed on the melted holes are being investigated for a wide variety of rocks and soils. Thermal and fluid-mechanics analyses of the melt flows are being conducted with the objective of optimizing penetraton designs. Initial economic models of the rock-melting concept extended to large tunnelers are being developed. Field tests and demonstrations of the prototype devices continue to be performed in a wide range of rock and soil types. The conceptual design of the electrically powered, self-propelled, remotely guided, horizontal tunnel-alignment prospecting system (Geoprospector) has been initiated. Such a device will also find applications in energy transmission, i.e., utility and pipeline installations. The long-term goal of the research is to develop the technology and prototype hardware that will ultimately lead to large tunneling devices, with improved advance rates and reduced tunnel project costs. The rockmelting concept includes elements that will result in innovative solutions to the three major functional areas of tunneling: rock disintegration, materials handling, and hole-support linings. The proposed excavation method, which is relatively insensitive to variations in rock formation, produces a liquid melt that can be chilled to a glass and formed into a dense, strong, firmly attached hole lining. Unique applications to large automated tunneling systems, ultradeep coring for geoscience research, and hot-rock penetration for geothermal energy development are being investigated, (auth)

Hanold, R.J.

1973-11-01T23:59:59.000Z

264

Fragmentation and quench behavior of corium melt streams in water  

DOE Green Energy (OSTI)

The interaction of molten core materials with water has been investigated for the pour stream mixing mode. This interaction plays a crucial role during the later stages of in-vessel core melt progression inside a light water reactor such as during the TMI-2 accident. The key issues which arise during the molten core relocation include: (i) the thermal attack and possible damage to the RPV lower head from the impinging molten fuel stream and/or the debris bed, (ii) the molten fuel relocation pathways including the effects of redistribution due to core support structure and the reactor lower internals, (iii) the quench rate of the molten fuel through the water in the lower plenum, (iv) the steam generation and hydrogen generation during the interaction, (v) the transient pressurization of the primary system, and (vi) the possibility of a steam explosion. In order to understand these issues, a series of six experiments (designated CCM-1 through {minus}6) was performed in which molten corium passed through a deep pool of water in a long, slender pour stream mode. Results discussed include the transient temperatures and pressures, the rate and magnitude of steam/hydrogen generation, and the posttest debris characteristics.

Spencer, B.W.; Wang, K.; Blomquist, C.A.; McUmber, L.M. [Argonne National Lab., IL (United States); Schneider, J.P. [Illinois Univ., Urbana, IL (United States). Dept. of Nuclear Engineering

1994-02-01T23:59:59.000Z

265

Gaps at the periphery of N Reactor graphite stack: A photographic survey  

Science Conference Proceedings (OSTI)

Miniature camera techniques were used to examine regions at the perimeter of the N Reactor graphite stack. Extensive coverage in previously unexplored regions was obtained. Gaps at the top of the unit show no visible evidence of graphite growth related distortion or displacement. Debris apparently associated with leaks in the subcritical monitors is observed but there are no indications that the material adversely affects the functions of safety, cooling, or monitoring systems. Gaps inside the right primary shield reveal graphite cooling tubes and other components in undisturbed condition. The only changes since construction are a thin layer of graphite dust from earlier rod channel renovation and oxide films on steel components. In the steam vent between moderator and reflector graphite, displaced and broken graphite blocks are observed. Again, no functional impairment of rod channels or other systems is observed. There is no evidence of distortion or deterioration of the graphite cooling tubes. The surveillance summarized here explores many previously hidden recesses. Some findings were unpredicted but none have given cause to change the safety status of the ball channel or control rod systems or to initiate any new safety enhancement measures. This report establishes a baseline for visual surveillance in perimeter regions of the N Reactor stack if operations resume. 10 refs., 22 figs., 1 tab.

Woodruff, E.M.; Weber, J.R.; Sinclair, R.B.

1988-09-01T23:59:59.000Z

266

The Core Melt Stabilization Concept of the EPR and its Experimental Validation  

Science Conference Proceedings (OSTI)

The strategy of the European Pressurized Water Reactor (EPR) to avoid severe accident conditions is based on the improved defense-in-depth approaches of the French 'N4' and the German 'Konvoi' plants. In addition, the EPR takes measures, at the design stage, to drastically limit the consequences of a postulated core-melt accident. The latter requires a strengthening of the confinement function and a significant reduction of the risk of short- and long-term containment failure. Scenarios with potentially high mechanical loads and large early releases like: high-pressure RPV failure, global hydrogen detonation, and energetic steam explosion must be prevented. The remaining low-pressure sequences are mitigated by dedicated measures that include hydrogen recombination, sustained heat removal out of the containment, and the stabilization of the molten core in an ex-vessel core catcher located in a compartment lateral to the pit. The spatial separation protects the core catcher from loads during RPV failure and, vice versa, eliminates concerns related with its unintended flooding during power operation. To make the relocation of the melt into the core catcher scenario-independent and robust against the uncertainties associated with in-vessel molten pool formation and RPV failure, the corium is temporarily retained, accumulated and conditioned in the pit during interaction with a sacrificial concrete layer. Spreading of the accumulated molten pool is initiated by penetrating a concrete plug in the bottom. The increase in surface-to-volume ratio achieved by the spreading process strongly enhances quenching and cool-down of the melt after flooding. The required water is passively drained from the IRWST. After availability of the containment heat removal system the steam from the boiling pool is re-condensed by sprays. The CHRS can also optionally cool the core catcher directly, which, in consequence, establishes a sub-cooled pool near-atmospheric pressure levels in the containment. The described concept rests on a large experimental knowledge base which covers all main phenomena involved, including melt interaction with structural material, melt spreading, melt and quenching, as well as the efficacy of the core catcher cooling. Besides giving an overview of the EPR core melt mitigation concept, the paper summarizes its R and D bases and describes which conclusions have been drawn from the various experimental projects and how these conclusions are used in the validation of the EPR concept. (author)

Fischer, Manfred [AREVA ANP GmbH (Germany)

2006-07-01T23:59:59.000Z

267

A safety assessment of the use of graphite in nuclear reactors licensed by the US NRC  

DOE Green Energy (OSTI)

This report reviews existing literature and knowledge on graphite burning and on stored energy accumulation and releases in order to assess what role, if any, a stored energy release can have in initiating or contributing to hypothetical graphite burning scenarios in research reactors. It also addresses the question of graphite ignition and self-sustained combustion in the event of a loss-of-coolant accident (LOCA). The conditions necessary to initiate and maintain graphite burning are summarized and discussed. From analyses of existing information it is concluded that only stored energy accumulations and releases below the burning temperature (650/sup 0/C) are pertinent. After reviewing the existing knowledge on stored energy it is possible to show that stored energy releases do not occur spontaneously, and that the maximum stored energy that can be released from any reactor containing graphite is a very small fraction of the energy produced during the first few minutes of a burning incident. The conclusions from these analyses are that the potential to initiate or maintain a graphite burning incident is essentially independent of the stored energy in the graphite, and depends on other factors that are unique for these reactors, research reactors, and for Fort St. Vrain. In order to have self-sustained rapid graphite oxidation in any of these reactors, certain necessary conditions of geometry, temperature, oxygen supply, reaction product removal, and a favorable heat balance must be maintained. There is no new evidence associated with either the Windscale Accident or the Chernobyl Accident that indicates a credible potential for a graphite burning accident in any of the reactors considered in this review.

Schweitzer, D.G.; Gurinsky, D.H.; Kaplan, E.; Sastre, C.

1987-09-01T23:59:59.000Z

268

Study on the Gasification and Melting Characteristics of Electronic Waste  

Science Conference Proceedings (OSTI)

The disposal of WEEE (waste electrical and electronic equipment) or “electronic waste” is an important issue in the whole world. Its gasification and melting characteristics were studied here. The experiments proved that over 50% of WEEE ... Keywords: WEEE, electronic waste, gasification, pyrolysis, melting

Wenlong Wang; Jing Sun; Chunyuan Ma; Yong Dong; Zhiqiang Wang; Xiren Xu; Zhanlong Song

2009-10-01T23:59:59.000Z

269

The Melting of Ice in Cold Stratified Water  

Science Conference Proceedings (OSTI)

We consider the melting of ice in cold water vertically stratified with salt. The study extends previous investigations of ice melting in cold water at uniform salinity and in warm water with a salinity gradient. We find, in agreement with the ...

Herbert E. Huppert; Edward G. Josberger

1980-06-01T23:59:59.000Z

270

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

DOE Green Energy (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

271

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

272

Science Accelerator content now includes multimedia  

Office of Scientific and Technical Information (OSTI)

Science Accelerator content now includes multimedia Science Accelerator has expanded its suite of collections to include ScienceCinema, which contains videos produced by the U.S....

273

Surface hardening of titanium alloys with melting depth controlled by heat sink  

DOE Patents (OSTI)

A process for forming a hard surface coating on titanium alloys includes providing a piece of material containing titanium having at least a portion of one surface to be hardened. The piece having a portion of a surface to be hardened is contacted on the backside by a suitable heat sink such that the melting depth of said surface to be hardened may be controlled. A hardening material is then deposited as a slurry. Alternate methods of deposition include flame, arc, or plasma spraying, electrodeposition, vapor deposition, or any other deposition method known by those skilled in the art. The surface to be hardened is then selectively melted to the desired depth, dependent on the desired coating thickness, such that a molten pool is formed of the piece surface and the deposited hardening material. Upon cooling a hardened surface is formed.

Oden, Laurance L. (Albany, OR); Turner, Paul C. (Albany, OR)

1995-01-01T23:59:59.000Z

274

Petroleum Gasoline & Distillate Needs Including the Energy ...  

U.S. Energy Information Administration (EIA)

Home > Petroleum > Analysis > Petroleum Gasoline & Distillate Needs Including the Energy Independence and Security Act (EISA) ...

275

Petroleum Gasoline & Distillate Needs Including the Energy ...  

U.S. Energy Information Administration (EIA)

Petroleum Gasoline & Distillate Needs Including the Energy Independence and Security Act (EISA) Impacts

276

Large-Scale Oceanographic Constraints on the Distribution of Melting and Freezing under Ice Shelves  

Science Conference Proceedings (OSTI)

Previous studies suggest that ice shelves experience asymmetric melting and freezing. Topography may constrain oceanic circulation (and thus basal melt–freeze patterns) through its influence on the potential vorticity (PV) field. However, melting ...

Christopher M. Little; Anand Gnanadesikan; Robert Hallberg

2008-10-01T23:59:59.000Z

277

Claisen Rearrangement of Graphite Oxide: A Route to Covalently Functionalized Graphenes  

E-Print Network (OSTI)

On the GO: The basal plane allylic alcohol functionality of graphite oxide (GO) can be converted into N,N-dimethylamide groups through an Eschenmoser–Claisen sigmatropic rearrangement by using N,N-dimethylacetamide dimethyl ...

Collins, William R.

278

F5: Characteristic of Al/Graphite Metal Matrix Composites via Friction ...  

Science Conference Proceedings (OSTI)

Thus, there are some tries to make advanced high-strength materials and the ... and line scanning were conducted to analyze the distribution of the graphite. ... Voltage Controlled Creep of a Nanoporous Gold/Electrolyte Hybrid Material ...

279

F-3: Hydrogen Storage Properties of Graphite-modified Mg–Ni–Ce ...  

Science Conference Proceedings (OSTI)

Abstract Scope, The Mg17Ni1.5Ce0.5 hydrogen storage composites with different contents of graphite were prepared by a new method of mechanical milling ...

280

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

DOE Green Energy (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 average 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. Also, our findings show that the magnetic properties of graphite surfaces, thin films or two dimensional graphene samples can be reliably studied using soft x-ray dichroism. Fundamental new insight into the magnetic properties of carbon based systems can thus be obtained.

Ohldag, H.; Esquinazi, P.; Arenholz, E.; Spemann, D.; Rothermel, M.; Setzer, A.; Butz, T.

2010-05-01T23:59:59.000Z

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

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

DOE Patents (OSTI)

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

Shaikh, S.N.; Ellis, P.E. Jr.; Lyons, J.E.

1994-08-02T23:59:59.000Z

282

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

283

SODIUM GRAPHITE REACTOR QUARTERLY PROGRESS REPORT FOR OCTOBER-DECEMBER 1955. SECTION A. SECTION B  

DOE Green Energy (OSTI)

An analysis was made of the nuclear parameters for sodium graphite reactor lattices. These parameters include thermal utilization, macroscopic cross sections, thermal diffusion length, and neutron absorption. Results of all calculations are given in graphical form. Test fuel slugs for the SRE were cycled up to 500 times between 100 and 500 deg C at the rate of 2 cycles/hr. Results are tabulated. The centrifugal casting of U alloy fuel slugs is briefly evaluated. Results of the microscopic examination of the extruded ThU breeder fuels are shown. The percent elongation of graphite due to the presence of Na is shown for various temperatures. Results of wear tests on graphite are also tabulated. The behavior of Zr in liquid Na was studied, and weight gains in Zr are summarized. Analog computer studies were continued, and data are included on the temperature effects of the response time of coolant channel Na outlet temperature thermocouples, the effects of continuous rod motion and pump speed changes on the outlet Na temperature and power, and the outlet temperature as a function of scram time. The critical evaluation of B--Ni rods is tabulated. The fuel rod assembly apparatus is described. Fuel rod development is discussed. Cyclograph traces of rods bonded with various Na--K alloys were recorded for rods at room temperature and heated to 450 and 600 deg F. The traces are indicative of uniform bonding. The moderator can fabrication and testing is also discussed. Tests were completed on Freeze Seal No. 2 for the 6-in. oval port Wedgeplug test valve at 450, 850, and 1250 deg F. The temperature gradients from the hot flange face to the end of the seal mechanism for various valve temperature conditions are shown. Sodium leak rates through the valve are tabulated. Progress in the development of a liquid Na level gage is briefly reported. The tubular heater experiment was completed, and the times to raise pipe temperatures from ambient to 350 deg F are tabulated. Designs for a 6-in. Na pump loop are described briefly. A one to 3.5 scale model of a SRE fuel element was constructed to study the effect of side drag on the element during insertion operations at those fuel channels located near the outlet of the upper plenum chamber. The calibration of the SRE fuel element orifices was studied. Control rod lead screw development is discussed. Development of the safety rod system is described. Core tank galling tests are summarized. Experiments to determine the effects of radiation on MoS/ sub 2/ are described. Dose buildup factors for the concretes to be used in the reactor top shield are tabulated. Constants for the quadratic representation of the dose buildup factor and the capture gamma rays from heavy concrete are also tabulated. The sodium pumps and service system are described. The rated cooling capacity of the SRE tetralin evaporative cooler was checked. Results of a study on the effects of NaK temperature on the H content of He are tabulated. (D.E.B.)

Martin, A.B.; Cochran, J.C. ed.

1956-04-15T23:59:59.000Z

284

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

DOE Green Energy (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

285

Hydrogen pumping and release by graphite under high flux plasma bombardment  

DOE Green Energy (OSTI)

Inert gas (helium or argon) plasma bombardment has been found to increase the surface gas adsorptivity of isotropic graphite (POCO-graphite), which can then getter residual gases in a high vacuum system. The inert gas plasma bombardment was carried out at a flux approx. = 1 x 10/sup 18/ ions s/sup -1/ cm/sup -2/ to a fluence of the order of 10/sup 21/ ions/cm/sup 2/ and at temperatures around 800/sup 0/C. The gettering capability of graphite can be easily recovered by repeating inert gas plasma bombardment. The activated graphite surface exhibits a smooth, sponge-like morphology with significantly increased pore openings, which correlates with the observed increase in the surface gas adsorptivity. The activated graphite surface has been observed to pump hydrogen plasma particles as well. From calibrated H-alpha measurements, the dynamic hydrogen retention capacity is evaluated to be as large as 2 x 10/sup 18/ H/cm/sup 2/ at temperatures below 100/sup 0/C and at a plasma bombarding energy of 300 eV. The graphite temperature was varied between 15 and 480/sup 0/C. Due to the plasma particle pumping capability, hydrogen recycling from the activated graphite surface is significantly reduced, relative to that from a pre-saturated surface. A pre-saturated surface was also observed to reproducibly pump a hydrogen plasma to a concentration of 9.5 x 10/sup 17/ H/cm/sup 2/. The hydrogen retention capacity of graphite is found to decrease with increasing temperature. A transient pumping mechanism associated with the sponge-like surface morphology is conjectured to explain the large hydrogen retention capacity. Hydrogen release behavior under helium and argon plasma bombardment was also investigated, and the result indicated the possibility of some in-pore retrapping effect. 43 refs., 11 figs.

Hirooka, Y.; Leung, W.K.; Conn, R.W.; Goebel, D.M.; LaBombard, B.; Nygren, R.; Wilson, K.L.

1988-01-01T23:59:59.000Z

286

Electrical resistivity studies on graphite at high pressure and low temperature  

Science Conference Proceedings (OSTI)

High pressure is shown to give a valuable insight into the intrinsic c-axis resistivity of Highly Oriented Pyrolitic Graphite (HOPG). For the purpose of improving the understanding of the fundamental behavior of this technologically important material, additional forms of graphitic material such as Grafoil, Single Crystal Graphite (SCG) and polycrystalline natural graphite were explored for a comparative analysis. A novel technique utilizing a gasketed diamond-anvil cell is described that permits four probe resistivity measurements at pressures of up to 40 kbar and temperatures extending down to 2 K while maintaining the integrity of samples as fragile as graphite. The four-lead arrangement is designed to avoid contact and lead-wire resistances which might otherwise obscure the comparatively small resistance changes of interest typical of highly conductive materials. The data on HOPG can be fitted well to a model describing conduction along the c-axis as composed of two components acting in parallel: an ordinary metallic one and a tunnelling conduction between crystallites. The total conductivity was found to be a superposition of both conductivities, and their respective weights depend on the quality of the graphite material.

Hockey, R.L.

1985-01-01T23:59:59.000Z

287

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

288

Energy Efficient Glass Melting - The Next Generation Melter  

Science Conference Proceedings (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

289

AN ADVANCED SODIUM-GRAPHITE REACTOR NUCLEAR POWER PLANT  

SciTech Connect

An advanced sodium-cooled, graphite-moderated nuclear power plant is described which utilizes high-pressure, high-temperature steam to generate electricity at a high thermal efficiency. Steam is generated at 2400 psig, superheated to 1050 deg F and, after partial expansion in the turbine, reheated to 1000 deg F. Net thermal efficiency of the plant is 42.3%. In a plant sized to produce a net electrical output of 256 Mw, the estimated cost is 8232/kw. Estimated cost of power generation is 6.7 mills/kwh. In a similar plant with a net electrical output of 530 Mw, the estimated power generating cost is 5.4 mills/ kwh. Most of the components of the plant are within the capability of current technology. The major exception is the fuel material, uranium carbide. Preliminary results of the development work now in progress indicate that uranium carbide would be an excellent fuel for high-temperature reactors, but temperature and burnup limitation have yet to be firmly established. Additional development work is also required on the steam generators. These are the single-barrier type similar to those which will be used in the Enrico Fernri Fast Breeder Reactor plant but produce steam at higher pressure and temperature. Questions also remain regarding the use of nitrogen as a cover gas over sodium at 1200 deg F and compatibility of the materials used in the primary neutron shield. All of these questions are currently under investigation. (auth)

Churchill, J.R.; Renard, J.

1960-03-15T23:59:59.000Z

290

The C1s core line in irradiated graphite  

Science Conference Proceedings (OSTI)

Recently, plasma deposited amorphous carbon films have been the subject of extensive experimental and theoretical investigations aimed at correlating their electronic, structural, and mechanical properties to growth parameters. To investigate these properties, different spectral parameters reflecting the electronic structure of carbon-based materials are proposed in literature. The effects of various electronic configurations on the carbon photoelectron spectra are analyzed here with particular attention to C1s core line with the aim to better interpret its structure. The latter is commonly fitted under the assumption that it can be described by using just two spectral components related to sp{sup 2} and sp{sup 3} hybrids. Their relative intensities are then used to estimate the sp{sup 2} and sp{sup 3} phases. We show that, in the presence of an amorphous network, the C1s line shape is the result of a more complex mixture of electronic states. Ar{sup +} irradiated graphite and successive oxidation was used to identify spectral features to better describe the C1s line shape.

Speranza, Giorgio; Minati, Luca; Anderle, Mariano [ITC-IRST, I-38050 Povo (Trento) (Italy)

2007-08-15T23:59:59.000Z

291

Magnetic properties of graphite irradiated with MeV ions  

SciTech Connect

We have studied the change in the magnetic properties produced on highly oriented pyrolytic graphite samples by irradiation of H, C, and N ions in the mega-electron-volt energy range. The use of specially made sample holders for the magnetic measurements provided high reproducibility allowing us to obtain directly the irradiation effects without any corrections or subtractions. Our results show that three magnetic phenomena are triggered by the defects produced by the irradiation, namely, Curie-type paramagnetism, ferromagnetism and an anomalous paramagnetic state that appears as precursor of the magnetic ordered state. Using SRIM simulations to estimate the amount of vacancies produced by the irradiation, the Curie-type paramagnetic response indicates an effective Bohr magneton number per nominally produced vacancy p=0.27+-0.02mu{sub B}. Direct measurements of the surface sample temperature during irradiation and the decrease in the (as-received) paramagnetic as well as ferromagnetic contributions after irradiation indicate that self-heating is one of the causes for small yield of ferromagnetism. Taking into account the hydrogen distribution in the virgin samples, the obtained results indicate that the induced ferromagnetism appears when the average vacancy distance is {approx}2 nm in the near surface region.

Ramos, M. A.; Munoz-Martin, A.; Climent-Font, A. [CMAM and Instituto de Ciencia de Materiales 'Nicolas Cabrera', Universidad Autonoma de Madrid, Cantoblanco, E-28049 Madrid (Spain); Barzola-Quiquia, J.; Esquinazi, P. [Division of Superconductivity and Magnetism, Institut fuer Experimentelle Physik II, Universitaet Leipzig, Linnestrasse 5, D-04103 Leipzig (Germany); Garcia-Hernandez, M. [Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, E-28049 Madrid (Spain)

2010-06-01T23:59:59.000Z

292

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

SciTech Connect

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

293

Melting of Aluminum by Electricity: A Review of Operating Practice and Discussion of Cost Factors for Melting Aluminum  

Science Conference Proceedings (OSTI)

In 1998, about 10 million tons of aluminum ingot and various forms of scrap were melted to produce a variety of products. The majority of the aluminum was melted in oil or natural gas-fired furnaces. However, as old gas-fired furnaces are being replaced or capacity is being increased, consideration is being given to electric-fired furnaces to obtain more energy efficient melting and increased yield of product. The purpose of this report is to acquaint the reader with the various types of commercial elect...

1992-03-31T23:59:59.000Z

294

Microstructural Properties of Gamma Titanium Aluminide Manufactured by Electron Beam Melting  

SciTech Connect

In recent years, Electron Beam Melting (EBM) has matured as a technology for additive manufacturing of dense metal parts. The parts are built by additive consolidation of thin layers of metal powder using an electron beam. With EBM, it is possible to create parts with geometries too complex to be fabricated by other methods, e.g. fine network structures and internal cavities. The process is run in vacuum, which makes it well suited for materials with a high affinity to oxygen, i.e. . titanium compounds. We present material data from a recently conducted study of how melt strategy affects EBM process for gamma titanium aluminide, Ti-48Al-2Cr-2Nb.The investigation includes microstructural characterization, grain size measurement and tensile testing.

Franzen, Sanna Fager [ARCAM AB; Karlsson, Joakim [ARCAM AB; Dehoff, Ryan R [ORNL; Ackelid, Ulf [ARCAM AB; Rios, Orlando [ORNL; Peter, William H [ORNL

2011-01-01T23:59:59.000Z

295

Stripe melting and quantum criticality in correlated metals  

E-Print Network (OSTI)

We study theoretically quantum melting transitions of stripe order in a metallic environment, and the associated reconstruction of the electronic Fermi surface. We show that such quantum phase transitions can be continuous ...

Mross, David Fabian

296

Rhyolite magma degassing: an experimental study of melt vesiculation  

Science Conference Proceedings (OSTI)

quires studying the separation of gas from melt in high- ly viscous liquids ..... been measured as a function of temperature on a natural rhyolite sample ( cylindrical ..... In general, bubble loss at constant foam volume has two sources: ( a) coal-.

297

On the Estimation of Antarctic Iceberg Melt Rate  

Science Conference Proceedings (OSTI)

Estimates of Antarctic iceberg melt rates made from field observations, iceberg distribution statistics, laboratory experiments and theoretical studies give a wide range of values. Evaluation of the errors associated with each method allows for ...

Steve Neshyba; Edward G. Josberger

1980-10-01T23:59:59.000Z

298

Modeling Forest Cover Influences on Snow Accumulation, Sublimation, and Melt  

Science Conference Proceedings (OSTI)

A comprehensive, physically based model of snow accumulation, redistribution, sublimation, and melt for open and forested catchments was assembled, based on algorithms derived from hydrological process research in Russia and Canada. The model was ...

A. N. Gelfan; J. W. Pomeroy; L. S. Kuchment

2004-10-01T23:59:59.000Z

299

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

300

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

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

Structure of Glass-Forming Melts - Lanthanide in Borosilicates  

Science Conference Proceedings (OSTI)

Over the past few years, we studied several complex Na2O-Al2O3-B2O3-SiO2 glass systems to answer key questions: effects of melt chemistry on solubility of lanthanide oxides; lanthanide solution behavior, and intermediate-range ordering in the melts. This paper summarizes our currently understanding on rare earth elements in borosilicate glasses, covering solution behavior, solubility limits, crystalization and phase separation.

Li, Hong; Li, Liyu; Qian, Morris; Strachan, Denis M.; Wang, Zheming

2004-05-17T23:59:59.000Z

302

SCALE ANALYSIS OF CONVECTIVE MELTING WITH INTERNAL HEAT GENERATION  

SciTech Connect

Using a scale analysis approach, we model phase change (melting) for pure materials which generate internal heat for small Stefan numbers (approximately one). The analysis considers conduction in the solid phase and natural convection, driven by internal heat generation, in the liquid regime. The model is applied for a constant surface temperature boundary condition where the melting temperature is greater than the surface temperature in a cylindrical geometry. We show the time scales in which conduction and convection heat transfer dominate.

John Crepeau

2011-03-01T23:59:59.000Z

303

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

304

FISSION PRODUCT TRAPS FOR USE IN HIGH-TEMPERATURE GAS-COOLED GRAPHITE REACTORS  

SciTech Connect

A proposal is given of an approach to a fission-product trapping system which appears feasible on the basis of thermodynamic and other data available. Reactor and trapping conditions are outlined. The half-lives, fission yields, and volatility of the fission products of interest are described. To provide the most effective retention at elevated temperatures, two types of reagents are required: a highly electropositive metal that will not melt or appreciably vaporize and which will form stable non-volatile compounds with non-metallic or near non-metallic fission products; and a reagent to provide a highly electronegative element to form stable, non-volatile compounds with metallic fission products. Thermodynamic properties are included for compounds formed by reactions between the fission products and the trapping reagents. (B.O.G.)

Zumwalt, L.R.

1958-03-13T23:59:59.000Z

305

Method for processing aluminum spent potliner in a graphite electrode arc furnace  

DOE Patents (OSTI)

A method of processing spent aluminum pot liner containing carbon, cyanide compositions, fluorides and inorganic oxides. The spend aluminum pot liner is crushed, iron oxide is added to form an agglomerated material. The agglomerated material is melted in an electric arc furnace having the electrodes submerged in the molten material to provide a reducing environment during the furnace operation. In the reducing environment, pot liner is oxidized while the iron oxides are reduced to produce iron and a slag substantially free of cyanide compositions and fluorides. An off-gas including carbon oxides and fluorine is treated in an air pollution control system with an afterburner and a scrubber to produce NaF, water and a gas vented to the atmosphere free of cyanide compositions, fluorine, and CO.

O' Connor, William K.; Turner, Paul C.; Addison, G.W. (AJT Enterprises, Inc.)

2002-12-24T23:59:59.000Z

306

Method for processing aluminum spent potliner in a graphite electrode ARC furnace  

SciTech Connect

A method of processing spent aluminum pot liner containing carbon, cyanide compositions, fluorides and inorganic oxides. The spent aluminum pot liner is crushed iron oxide is added to form an agglomerated material. The agglomerated material is melted in an electric arc furnace having the electrodes submerged in the molten material to provide a reducing environment during the furnace operation. In the reducing environment, pot liner is oxidized while the iron oxides are reduced to produce iron and a slag substantially free of cyanide compositions and fluorides. An off-gas including carbon oxides and fluorine is treated in an air pollution control system with an afterburner and a scrubber to produce NaF, water and a gas vented to the atmosphere free of cyanide compositions, fluorine and CO.

O' Connor, William K. (Lebanon, OR); Turner, Paul C. (Independence, OR); Addison, Gerald W. (St. Stephen, SC)

2002-12-24T23:59:59.000Z

307

Surface impurity removal from DIII-D graphite tiles by boron carbide grit blasting  

SciTech Connect

During the latter half of 1992, the DIII-D tokamak at General Atomics (GA) underwent several modifications of its interior. One of the major tasks involved the removal of accumulated metallic impurities from the surface of the graphite tiles used to line the plasma facing surfaces inside of the tokamak. Approximately 1500 graphite tiles and 100 boron nitride tiles from the tokamak were cleaned to remove the metallic impurities. The cleaning process consisted of several steps: the removed graphite tiles were permanently marked, surface blasted using boron carbide (B{sub 4}C) grit media (approximately 37 {mu}m. diam.), ultrasonically cleaned in ethanol to remove loose dust, and outgassed at 1000{degrees}C. Tests were done using, graphite samples and different grit blaster settings to determine the optimum propellant and abrasive media pressures to remove a graphite layer approximately 40-50 {mu}m deep and yet produce a reasonably smooth finish. EDX measurements revealed that the blasting technique reduced the surface Ni, Cr, and Fe impurity levels to those of virgin graphite. In addition to the surface impurity removal, tritium monitoring was performed throughout the cleaning process. A bubbler system was set up to monitor the tritium level in the exhaust gas from the grit blaster unit. Surface wipes were also performed on over 10% of the tiles. Typical surface tritium concentrations of the tiles were reduced from about 500 dpm/100 cm{sup 2} to less than 80 dpm/100 cm{sup 2} following the cleaning. This tile conditioning, and the installation of additional graphite tiles to cover a high fraction of the metallic plasma facing surfaces, has substantially reduced metallic impurities in the plasma discharges which has allowed rapid recovery from a seven-month machine opening and regimes of enhanced plasma energy confinement to be more readily obtained. Safety issues concerning blaster operator exposure to carcinogenic metals and radioactive tritium will also be addressed.

Lee, R.L.; Hollerbach, M.A.; Holtrop, K.L.; Kellman, A.G.; Taylor, P.L.; West, W.P.

1993-11-01T23:59:59.000Z

308

Effect of electrode density on cycle performance and irreversible capacity loss for natural graphite anode in lithium ion batteries  

DOE Green Energy (OSTI)

The effect of electrode thickness and density for unpressed and pressed natural graphite electrodes were studied using electrochemical characterization. Pressing the graphite electrode decreases the reversible capacity and the irreversible capacity loss during formation. As electrode density increased, the capacity retention at high rate increased until 0.9g/cm{sup 3}, and then decreased. The cycle performances of the pressed graphite electrodes were more stable than the unpressed one. Pressing graphite electrode affected on its electrochemical characterization such as irreversible capacity loss, high rate cycling and cycle performance.

Shim, Joongpyo; Striebel, Kathryn A.

2002-12-02T23:59:59.000Z

309

Blind Benchmark Calculations for Melt Spreading in the ECOSTAR Project  

SciTech Connect

The Project ECOSTAR (5. EC Framework Programme) on Ex-Vessel Core Melt Stabilisation Research is oriented towards the analysis and mitigation of severe accident sequences that could occur in the ex-vessel phase of a postulated core melt accident. Spreading of the corium melt on the available basement surface is an important process, which defines the initial conditions for concrete attack and for the efficiency of cooling in case of water contact, respectively. The transfer and spreading of the melt on the basement is one of the major issues in ECOSTAR. This is addressed here by a spreading code benchmark involving a large-scale spreading experiment that is used for the validation of the existing spreading codes. The corium melt is simulated by a mixture of Al{sub 2}O{sub 3}, SiO{sub 2}, CaO and FeO with a sufficiently wide freezing interval. In the 3-dim benchmark test ECOKATS-1 170 litres of oxide melt are poured onto a 3 m by 4 m concrete surface with a low flow rate of about 2 l/s. From the results of an additional 2-dim channel experiment some basic rheological data (e.g. initial viscosity) are obtained in order to minimise the uncertainty in material properties of the melt. The participating spreading codes CORFLOW (Framatome ANP/FZK), LAVA (GRS), and THEMA (CEA) differ from each other by their focus of modelling and the assumptions made to simplify the relevant transport equations. In a first step both experiments (3-dim/2-dim) are calculated blindly by the participating codes. This serves for an overall assessment of the codes capabilities to predict the spreading of a melt with rather unknown material properties. In a second step the 3-dim experiment ECOKATS-1 is recalculated by the codes with the more precise knowledge of the rheological behaviour of the oxide melt in the 2-dim experiment. This, in addition, serves for the validation of the codes' capabilities to predict the spreading of a melt with well-known material properties. Based on the benchmark results and taking the specific validation process for each of the three codes applied into account, it is recommended that the spreading issue for reactor safety research be considered closed. (authors)

Spengler, C.; Allelein, H.J. [Gesellschaft fuer Anlagen- und Reaktorsicherheit, Schwertnergasse 1, 50667 Cologne (Germany); Foit, J.J.; Alsmeyer, H. [Forschungszentrum Karlsruhe, P.O. Box 36 40, 76021 Karlsruhe (Germany); Spindler, B.; Veteau, J.M. [CEA, 17, rue des Martyrs, 38054 Grenoble (France); Artnik, J.; Fischer, M. [Framatome ANP, P.O. Box 32 20, 91050 Erlangen (Germany)

2004-07-01T23:59:59.000Z

310

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

2013-02-19T23:59:59.000Z

311

The effect of compression on natural graphite anode performance and matrix conductivity  

DOE Green Energy (OSTI)

Anodes for lithium-ion cells were constructed from three types of natural graphite, two coated spherical and one flaky. Anode samples were compressed from 0 to 300 kg/cm2 and studied in half-cells to study the relations between anode density, SEI formation and anode cyclability. The C/25 formation of the SEI layer was found to depend on the nature of the graphite and the anode density. Compression of the uncoated graphite lead to an increased conductivity, but only slight improvements in the efficiency of the formation process. Compression of the anodes made from the amorphous-carbon-coated graphites greatly improved both the reversible capacity and first-cycle efficiency. In addition, the fraction of the irreversible charge associated with the surface of the graphite increased with compression, from both an increase in the electrolyte contact as well as compression of the amorphous layer. The cyclability of all of the anodes tended to improve with compression. This suggests that it is the improvement in the conductivity of the anode plays more of a role in the improvement in the cyclability than the formation process.

Striebel, K.A.; Sierra, A.; Shim, J.; Wang, C.-W.; Sastry, A.M.

2004-03-11T23:59:59.000Z

312

Mixed Waste Treatment Cost Analysis for a Range of GeoMelt Vitrification Process Configurations  

Science Conference Proceedings (OSTI)

GeoMelt is a batch vitrification process used for contaminated site remediation and waste treatment. GeoMelt can be applied in several different configurations ranging from deep subsurface in situ treatment to aboveground batch plants. The process has been successfully used to treat a wide range of contaminated wastes and debris including: mixed low-level radioactive wastes; mixed transuranic wastes; polychlorinated biphenyls; pesticides; dioxins; and a range of heavy metals. Hypothetical cost estimates for the treatment of mixed low-level radioactive waste were prepared for the GeoMelt subsurface planar and in-container vitrification methods. The subsurface planar method involves in situ treatment and the in-container vitrification method involves treatment in an aboveground batch plant. The projected costs for the subsurface planar method range from $355-$461 per ton. These costs equate to 18-20 cents per pound. The projected cost for the in-container method is $1585 per ton. This cost equates to 80 cents per pound. These treatment costs are ten or more times lower than the treatment costs for alternative mixed waste treatment technologies according to a 1996 study by the US Department of Energy.

Thompson, L. E.

2002-02-27T23:59:59.000Z

313

FINAL REPORT on Experimental Validation of Stratified Flow Phenomena, Graphite Oxidation, and Mitigation Strategies of Air Ingress Accidents  

Science Conference Proceedings (OSTI)

The U.S. Department of Energy is performing research and development that focuses on key phenomena that are important during challenging scenarios that may occur in the Next Generation Nuclear Plant (NGNP)/Generation IV very high temperature reactor (VHTR). Phenomena Identification and Ranking studies to date have identified the air ingress event, following on the heels of a VHTR depressurization, as very important. Consequently, the development of advanced air ingress-related models and verification & validation are of very high priority for the NGNP Project. Following a loss of coolant and system depressurization incident, air ingress will occur through the break, leading to oxidation of the in-core graphite structure and fuel. This study indicates that depending on the location and the size of the pipe break, the air ingress phenomena are different. In an effort to estimate the proper safety margin, experimental data and tools, including accurate multidimensional thermal-hydraulic and reactor physics models, a burn-off model, and a fracture model are required. It will also require effective strategies to mitigate the effects of oxidation, eventually. This 3-year project (FY 2008–FY 2010) is focused on various issues related to the VHTR air-ingress accident, including (a) analytical and experimental study of air ingress caused by density-driven, stratified, countercurrent flow, (b) advanced graphite oxidation experiments, (c) experimental study of burn-off in the core bottom structures, (d) structural tests of the oxidized core bottom structures, (e) implementation of advanced models developed during the previous tasks into the GAMMA code, (f) full air ingress and oxidation mitigation analyses, (g) development of core neutronic models, (h) coupling of the core neutronic and thermal hydraulic models, and (i) verification and validation of the coupled models.

Chang H. Oh; Eung S. Kim; Hee C. NO; Nam Z. Cho

2011-01-01T23:59:59.000Z

314

Intentionally Including - Engaging Minorities in Physics Careers |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

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

315

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

316

Molecular dynamics simulation of UO2 nanocrystals melting  

E-Print Network (OSTI)

In this article we study melting of uranium dioxide (UO2) nanocrystals (NC) isolated in vacuum (i.e. non-periodic boundary conditions) using molecular dynamics (MD) in the approximation of pair potentials and rigid ions. We calculate the size dependence of the temperature and heat of melting, the density jump for crystals of cubic shape and volumes up to 1000 nm^3 (50000 particles). Linear and parabolic extrapolations of these dependences to macroscopic (infinite) size are considered, the parabolic is found to be better suited for the analysis of data on the temperature and the heat of melting. The closest to the modern experimental data estimates of the melting temperature of macrocrystals are obtained using the interaction potentials Goel-08 (2969K), Yakub-09 (3105K) and MOX-07 (3291K). The density jump at melting is well reproduced by Yakub-09 (8.66%) and MOX-07 (7.97%). The heat of fusion for all sets of the potentials considered is found to be underestimated by 50-75%, possibly because of the excluded he...

Boyarchenkov, A S; Nekrasov, K A; Kupryazhkin, A Ya

2011-01-01T23:59:59.000Z

317

FY-09 Report: Experimental Validation of Stratified Flow Phenomena, Graphite Oxidation, and Mitigation Strategies of Air Ingress Accidents  

Science Conference Proceedings (OSTI)

The Idaho National Laboratory (INL), under the auspices of the U.S. Department of Energy, is performing research and development that focuses on key phenomena important during potential scenarios that may occur in the Next Generation Nuclear Plant (NGNP)/Gen-IV very high temperature reactor (VHTR). Phenomena Identification and Ranking Studies to date have identified that an air ingress event following on the heels of a VHTR depressurization is a very important incident. Consequently, the development of advanced air ingress-related models and verification and validation data are a very high priority for the NGNP Project. Following a loss of coolant and system depressurization incident, air will enter the core through the break, leading to oxidation of the in-core graphite structure and fuel. If this accident occurs, the oxidation will accelerate heat-up of the bottom reflector and the reactor core and will eventually cause the release of fission products. The potential collapse of the core bottom structures causing the release of CO and fission products is one of the concerns. Therefore, experimental validation with the analytical model and computational fluid dynamic (CFD) model developed in this study is very important. Estimating the proper safety margin will require experimental data and tools, including accurate multidimensional thermal-hydraulic and reactor physics models, a burn-off model, and a fracture model. It will also require effective strategies to mitigate the effects of oxidation. The results from this research will provide crucial inputs to the INL NGNP/VHTR Methods Research and Development project. The second year of this three-year project (FY-08 to FY-10) was focused on (a) the analytical, CFD, and experimental study of air ingress caused by density-driven, stratified, countercurrent flow; (b) advanced graphite oxidation experiments and modeling; (c) experimental study of burn-off in the core bottom structures, (d) implementation of advanced graphite oxidation models into the GAMMA code, and (f) air ingress and oxidation mitigation analyses of the whole air-ingress scenario.

Chang H. Oh; Eung S. Kim

2009-12-01T23:59:59.000Z

318

DISASTER POLICY Including Extreme Emergent Situations (EES)  

E-Print Network (OSTI)

on the ACGME website with information relating to the ACGME response to the disaster. 3. The University-specific Program Requirements. Defined Responsibilities Following the Declaration of a Disaster or Extreme EmergentPage 123 DISASTER POLICY Including Extreme Emergent Situations (EES) The University of Connecticut

Oliver, Douglas L.

319

Evaluation of graphite/steam interactions for ITER (International Thermonuclear Experimental Reactor)  

DOE Green Energy (OSTI)

In this report we present the results of an experimental/analytical study designed to determine the quantity of hydrogen generated during a coolant inleakage accident in ITER. This hydrogen could represent a potential explosive hazard, provided the proper conditions exist, causing machine damage and release of radioactive material. We have measured graphite/steam reaction rates for several graphites and carbon-based composites at temperatures between 1000 C and 1700 C. The effects of steam flow rate, and partial pressure were also examined. The measured reaction rates correlated well with two Arrhenius type relationships. We have used the relationships for GraphNOL N3M in a thermal model to determine that for ITER the quantity of hydrogen produced would range between 5 and 35 kg, depending upon how the graphite tiles are attached to the first wall. While 5 kg is not a significant concern, 35 kg presents an explosive hazard. 20 refs., 14 figs., 1 tab.

Smolik, G.R.; Merrill, B.J.; Piet, S.J.; Holland, D.F.

1990-09-01T23:59:59.000Z

320

Woven graphite fiber structures for use in ultra-light weigth heat exchangers  

Science Conference Proceedings (OSTI)

As part of U.S. Department of Energy efforts to find novel approaches for thermal management and heat recovery, work was undertaken at Oak Ridge National Laboratory (ORNL) to investigate the use of graphite-based materials for heat exchanger and thermal management devices. From this effort, lightweight, robust woven graphite-fiber structures were developed which provide high conductivity paths along the direction of the graphite fibers. These structures were produced and characterized for air permeability/pressure drop and thermal (heat transfer) performance. Results have been shown to be favorable for using such structures in ultra-light weight heat exchanger applications such as vehicle radiators or other areas where light weight, compact, conformable heat transfer devices are needed.

Hemrick, James Gordon [ORNL; Lara-Curzio, Edgar [ORNL; Loveland, Erick R [ORNL; Sharp, Keith W [ORNL; Schartow, Robert [3TEX Incorporated

2011-01-01T23:59:59.000Z

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.


321

Melt processing of Bi--2212 superconductors using alumina  

DOE Patents (OSTI)

Superconducting articles and a method of forming them, where the superconducting phase of an article is Bi.sub.2 Sr.sub.2 CaCu.sub.2 O.sub.y (Bi-2212). Alumina is combined with Bi-2212 powder or Bi-2212 precursor powder and, in order to form an intimate mixture, the mixture is melted and rapidly cooled to form a glassy solid. The glassy solid is comminuted and the resulting powder is combined with a carrier. An alternative to melting is to form the mixture of nanophase alumina and material having a particle size of less than about 10 microns. The powder, with the carrier, is melt processed to form a superconducting article.

Holesinger, Terry G. (Los Alamos, NM)

1999-01-01T23:59:59.000Z

322

Buildings Included on EMS Reports"  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

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"

323

Status Update for the Evaluation of Electromagnetic Nondestructive Evaluation System for Detecting and Quantifying Graphitization in High-Energy Piping  

Science Conference Proceedings (OSTI)

The project team performed several studies to evaluate the balanced field electromagnetic technique (BFET) for detection, and possibly classification, of graphitization in carbon-molybdenum tubing and piping. Samples of boiler tubes and high-energy pipes suspected to contain graphitization were procured from five power plants in the United ...

2013-10-25T23:59:59.000Z

324

Power generation method including membrane separation  

SciTech Connect

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

325

Electric power monthly, September 1990. [Glossary included  

SciTech Connect

The purpose of this report is to provide energy decision makers with accurate and timely information that may be used in forming various perspectives on electric issues. The power plants considered include coal, petroleum, natural gas, hydroelectric, and nuclear power plants. Data are presented for power generation, fuel consumption, fuel receipts and cost, sales of electricity, and unusual occurrences at power plants. Data are compared at the national, Census division, and state levels. 4 figs., 52 tabs. (CK)

1990-12-17T23:59:59.000Z

326

EFFECT OF GLASS-BATCH MAKEUP ON THE MELTING PROCESS  

SciTech Connect

The response of a glass batch to heating is determined by the batch makeup and in turn determines the rate of melting. Batches formulated for a high-alumina nuclear waste to be vitrified in an all-electric melter were heated at a constant temperature-increase rate to determine changes in melting behavior in response to the selection of batch chemicals and silica grain-size as well as the addition of heat-generating reactants. The type of batch materials and the size of silica grains determine how much, if any, primary foam occurs during melting. Small quartz grains, 5 {micro}m in size, caused extensive foaming because their major portion dissolved at temperatures <800 C, contributing to the formation of viscous glass forming melt that trapped evolving batch gases. Primary foam did not occur in batches with larger quartz grains, {+-}75 {micro}m in size, because their major portion dissolved at temperatures >800 C when batch gases no longer evolved. The exothermal reaction of nitrates with sucrose was ignited at a temperature as low as 160 C and caused a temporary jump in temperature of several hundred degrees. Secondary foam, the source of which is oxygen from redox reactions, occurred in all batches of a limited composition variation involving five oxides, B{sub 2}O{sub 3}, CaO, Li{sub 2}O, MgO, and Na{sub 2}O. The foam volume at the maximum volume-increase rate was a weak function of temperature and melt basicity. Neither the batch makeup nor the change in glass composition had a significant impact on the dissolution of silica grains. The impacts of primary foam generation on glass homogeneity and the rate of melting in large-scale continuous furnaces have yet to be established via mathematical modeling and melter experiments.

KRUGER AA; HRMA P

2010-12-07T23:59:59.000Z

327

Cathodic processes at electrodes in potassium fluoride-hydrofluoric acid (1/2) and potassium hydroxide-water (1/2) melts and the effect of adsorbed catalyst poisons.  

E-Print Network (OSTI)

??The industrial production of F2 is through the electrolysis process from HF melt. The reaction of HF??? F2+H2 includes the anodic production of F2 and… (more)

Gao, Lijun.

1994-01-01T23:59:59.000Z

328

Decontamination and decarburization of stainless and carbon steel by melt refining  

Science Conference Proceedings (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

329

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

330

The Melt-Dilute Treatment of Al-Base Highly Enriched DOE Spent Nuclear Fuels: Principles and Practices  

SciTech Connect

The melt-dilute treatment technology program is focused on the development and implementation of a treatment technology for diluting highly enriched (>20 percent 235U) aluminum spent nuclear fuel to low enriched levels (<20 percent 235U) and qualifying the LEU Al-SNF form for geologic repository storage. In order to reduce the enrichment of these assemblies prior to ultimate geologic repository disposal, the melt-dilute technology proposes to melt these SNF assemblies and then dilute with additions of depleted uranium. The benefits accrued from this treatment process include the potential for significant volume reduction, reduced criticality potential, and the potential for enhanced SNF form characteristics. The emphasis within the development program to date has been on determining the process metallurgy and off-gas system design for the treatment of all types of Al SNF (UAlx, Al-U3O8, and Al-U3Si2). In determining the process metallurgy a wide range of alloys, representative of those expected in the Al-SNF form, have been fabricated and their product characteristics, namely microstructure, homogeneity, phase composition, and "ternary" constituent effects have been analyzed. As a result of the presence of species within the melt which will possess significant vapor pressures in the desired operating temperature range an off-gas system is necessary. Of the volitile species the one of greatest concern is 137Cs.

Adams, T.M.

1998-11-25T23:59:59.000Z

331

Melting Processes and Solidification in Alloys 718-625  

Science Conference Proceedings (OSTI)

much heat loss during teeming.4-6 .... dendritic network which is characteristic of this alloy, interdendritic flow of highly- segregated liquid can ..... F.J. Zanner et al., “Observation of Melt rate as a Function of Arc Power,” Met Trans. 15B, 1984) ...

332

Phase-field simulations of partial melts in geological materials  

Science Conference Proceedings (OSTI)

A diffuse interface description based on a multi-phase-field model for geological grain microstructures is introduced, especially useful in the treatment of partially molten structures. Each grain as well as different phases are represented by individual ... Keywords: Grain growth, Microstructure, Numerical modelling, Partial melt, Phase-field model

Frank Wendler; Jens K. Becker; Britta Nestler; Paul D. Bons; Nicolas P. Walte

2009-09-01T23:59:59.000Z

333

The Impact of Melting Ice on Ocean Waters  

Science Conference Proceedings (OSTI)

Ice melts when it is in contact with ocean waters that have temperatures above the in situ freezing point. The product is a mixture of meltwater and seawater having properties intermediate between those of the two components. Density is one of ...

Adrian Jenkins

1999-09-01T23:59:59.000Z

334

Decontamination of steel by melt refining: A literature review  

SciTech Connect

It has been reported that a large amount of metal waste is produced annually by nuclear fuel processing and nuclear power plants. These metal wastes are contaminated with radioactive elements, such as uranium and plutonium. Current Department of Energy guidelines require retrievable storage of all metallic wastes containing transuranic elements above a certain level. Because of high cost, it is important to develop an effective decontamination and volume reduction method for low level contaminated metals. It has been shown by some investigators that a melt refining technique can be used for the processing of the contaminated metal wastes. In this process, contaminated metal is melted wit a suitable flux. The radioactive elements are oxidized and transferred to a slag phase. In order to develop a commercial process it is important to have information on the thermodynamics and kinetics of the removal. Therefore, a literature search was carried out to evaluate the available information on the decontamination uranium and transuranic-contaminated plain steel, copper and stainless steel by melt a refining technique. Emphasis was given to the thermodynamics and kinetics of the removal. Data published in the literature indicate that it is possible to reduce the concentration of radioactive elements to a very low level by the melt refining method. 20 refs.

Ozturk, B.; Fruehan, R.J. [Carnegie-Mellon Univ., Pittsburgh, PA (United States)

1994-12-31T23:59:59.000Z

335

Extensional and Flexural Waves in a Thin-Walled Graphite/Epoxy Tube  

Science Conference Proceedings (OSTI)

Simulated acoustic emission signals were induced in a thin-walled graphite/epoxy tube by means of lead breaks (Hsu-Neilsen source). The tube is of similar material and layup to be used by NASA in fabricating the struts of Space Station Freedom. The resulting ...

Prosser William H.; Gorman Michael R.; Dorighi John

1992-01-01T23:59:59.000Z

336

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

Science Conference Proceedings (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

337

2012 CHEMISTRY & PHYSICS OF GRAPHITIC CARBON MATERIALS GORDON RESEARCH CONFERENCE, JUNE 17-22, 2012  

Science Conference Proceedings (OSTI)

This conference will highlight the urgency for research on graphitic carbon materials and gather scientists in physics, chemistry, and engineering to tackle the challenges in this field. The conference will focus on scalable synthesis, characterization, novel physical and electronic properties, structure-properties relationship studies, and new applications of the carbon materials. Contributors

Fertig, Herbert

2012-06-22T23:59:59.000Z

338

Direct laser writing of micro-supercapacitors on hydrated graphite oxide films  

E-Print Network (OSTI)

Direct laser writing of micro-supercapacitors on hydrated graphite oxide films Wei Gao1 , Neelam, Bingqing Wei3 and Pulickel M. Ajayan1,2 * Microscale supercapacitors provide an important complement characteristics similar to that observed for Nafion membranes10,11. The result- ing micro-supercapacitor devices

Ajayan, Pulickel M.

339

Field Tests of a New Type of Graphite-Fiber Electrode for Measuring Motionally Induced Voltages  

Science Conference Proceedings (OSTI)

On the basis of a field experiment in a tidal channel, comparisons have been undertaken between a new type of graphite-fiber electrode and conventional Ag/AgCl sensors for measurements of motionally induced voltages. The fiber electrode works ...

Lennart Crona; Tim Fristedt; Peter Lundberg; Peter Sigray

2001-01-01T23:59:59.000Z

340

Jaszczak et al. 1 MICRO-AND NANO-SCALE GRAPHITE CONES AND TUBES FROM HACKMAN  

E-Print Network (OSTI)

@mtu.edu Present address: The Procter and Gamble Company, Corporate Analytical, 11810 E. Miami River Rd., Mailbox are composed of tabular graphite crystals greatly elongated in the direction of the fiber axis, electron microscopy, crystal growth, crystal morphology, Raman spectroscopy, stable carbon isotopes

Jaszczak, John A.

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

E21: Cast Iron Casing Cracking Due to Chunky Graphite Formation  

Science Conference Proceedings (OSTI)

Abstract Scope, In the recent years quality inspection of large turbomachinery casings made of ductile cast ... of chunky graphite formation, methods detection and acceptance criteria. ... A2: Fabrication of Bio-Structures Via Microbubbling ..... Cyclic Sintered Nd-Fe-B Magnets by Transmission Electron Microscopy Analysis.

342

Models of Procyon A including seismic constraints  

E-Print Network (OSTI)

Detailed models of Procyon A based on new asteroseismic measurements by Eggenberger et al (2004) have been computed using the Geneva evolution code including shellular rotation and atomic diffusion. By combining all non-asteroseismic observables now available for Procyon A with these seismological data, we find that the observed mean large spacing of 55.5 +- 0.5 uHz favours a mass of 1.497 M_sol for Procyon A. We also determine the following global parameters of Procyon A: an age of t=1.72 +- 0.30 Gyr, an initial helium mass fraction Y_i=0.290 +- 0.010, a nearly solar initial metallicity (Z/X)_i=0.0234 +- 0.0015 and a mixing-length parameter alpha=1.75 +- 0.40. Moreover, we show that the effects of rotation on the inner structure of the star may be revealed by asteroseismic observations if frequencies can be determined with a high precision. Existing seismological data of Procyon A are unfortunately not accurate enough to really test these differences in the input physics of our models.

P. Eggenberger; F. Carrier; F. Bouchy

2005-01-14T23:59:59.000Z

343

Analysis of capsule HFR-B1 graphite-corrosion data  

SciTech Connect

The recently completed irradiation of capsule HFR-B1 in the high-flux reactor at the Pitten Establishment in The Netherlands provided some excellent data for fission-product release. The data were obtained under irradiation and temperature conditions close to those expected during normal operation of the Modular High-Temperature Gas-cooled Reactor (MHTGR). Some of the tests at Petten were designed to measure release of fission gases during hydrolysis of failed fuel. Hydrolysis was initiated by injecting known amounts of water vapor into the capsule sweep gas. The measured concentrations of CO and CO{sub 2} in the capsule sweep gas indicated that a non-negligible amount of graphite corrosion was also occurring during the hydrolysis tests. Hence, these measurements provide some unique data for in-pile corrosion of grade H-4541 graphite by steam. In the present report, an analysis of graphite corrosion during the Petten hydrolysis tests is described. The calculations were performed using the REACT program, which is based on an improved corrosion model. The REACT program was developed as part of a research program at the University of California, San Diego, and is in operational status in the General Atomics (GA) Production Code Library. Predictions obtained with REACT show excellent agreement with the Petten graphite-corrosion data. This good agreement indicates that the currently used correlation for the steam-graphite reaction rate, which was obtained from out-of-pile measurements, may also be used to predict in-pile corrosion with good accuracy. 8 refs., 19 figs., 2 tabs.

Richards, M.B.; Gillespie, A.G.

1991-01-01T23:59:59.000Z

344

The Effect of Bubbles Released from a Melting Ice Wall on the Melt-Driven Convection in Salt Water  

Science Conference Proceedings (OSTI)

The buoyancy created by the release of air bubbles from melting glacial ice walls results from both the upward drag of the bubbles and the density defect caused by the steady-state distribution of bubbles in the water. Calculations using typical ...

Edward G. Josberger

1980-03-01T23:59:59.000Z

345

Surface Melting over Ice Shelves and Ice Sheets as Assessed from Modeled Surface Air Temperatures  

Science Conference Proceedings (OSTI)

Summer surface melting plays an important role in the evolution of ice shelves and their progenitor ice sheets. To explore the magnitude of surface melt occurring over modern ice shelves and ice sheets in a climate scenario forced by ...

Jeremy G. Fyke; Lionel Carter; Andrew Mackintosh; Andrew J. Weaver; Katrin J. Meissner

2010-04-01T23:59:59.000Z

346

Spatial and Temporal Transferability of a Distributed Energy-Balance Glacier Melt Model  

Science Conference Proceedings (OSTI)

Modeling melt from glaciers is crucial to assessing regional hydrology and eustatic sea level rise. The transferability of such models in space and time has been widely assumed but rarely tested. To investigate melt model transferability, a ...

Andrew H. MacDougall; Gwenn E. Flowers

2011-03-01T23:59:59.000Z

347

The Melting Effect as a Factor in Precipitation-Type Forecasting  

Science Conference Proceedings (OSTI)

The process of atmospheric cooling due to melting precipitation is examined to evaluate its contribution to determining precipitation type. The “melting effect” is typically of second-order importance compared to other processes that influence ...

John S. Kain; Stephen M. Goss; Michael E. Baldwin

2000-12-01T23:59:59.000Z

348

A Model of Intense Downdrafts Driven by the Melting and Evaporation of Precipitation  

Science Conference Proceedings (OSTI)

A ono-dimensioral time-dependent model of a downdraft driven by the melting and evaporation of precipitation and precipitation loading is formulated. Equations for particle melting, particle evaporation, particle concentration, precipitation ...

R. C. Srivastava

1987-07-01T23:59:59.000Z

349

The Effect of Melting Processes on the Development of a Tropical and a Midlatitude Squall Line  

Science Conference Proceedings (OSTI)

Several sensitivity tests are performed to assess the effect of melting processes on the development of a midlatitude continental squall line and a tropical oceanic squall line. It is found that melting processes play an important role in the ...

W-K. Tao; J. R. Scala; B. Ferrier; J. Simpson

1995-06-01T23:59:59.000Z

350

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

Science Conference Proceedings (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

351

Thermodynamic properties of adsorbed mixtures of benzene and cyclohexane on graphitized carbon and activated charcoal at 30/degree/c  

SciTech Connect

Experimental data at 30/degree/C are reported for the adsorption of mixtures of benzene and cyclohexane on two types of carbon surface: graphitized carbon and activated charcoal. The properties of the adsorbed solution approach those of bulk liquid at vapor saturation for graphitized carbon, but not for activated charcoal. The mixtures adsorbed on graphitized carbon are nonideal, and the deviations from ideality increase with surface coverage. For activated charcoal, the adsorbed mixtures are nearly ideal at all coverages. Mixture behavior for both adsorbents can be predicted without using experimental data for the adsorbed mixtures. 11 refs.

Myers, A.L.; Minka, C.; Ou, D.Y.

1982-01-01T23:59:59.000Z

352

CATALYTIC LIQUEFACTION BY ZINC CHLORIDE MELTS AT PRE-PYROLYSIS TEMPERATURE  

E-Print Network (OSTI)

blending and reaction conditions would be less than 10 centipoises, the effective viscosity of the melt/coal

Vermeulen, T.

2012-01-01T23:59:59.000Z

353

Physical Basis for the Temperature-Based Melt-Index Method  

Science Conference Proceedings (OSTI)

The close relationship between air temperature measured at standard screen level and the rate of melt on snow and ice has been widely used to estimate the rate of melt. The parameterization of the melt rate using air temperature usually takes a ...

Atsumu Ohmura

2001-04-01T23:59:59.000Z

354

An Integrated Method for Accurate Determination of Melting in High-Pressure Laser Heating Experiments  

SciTech Connect

We present an integrated approach for melting determination by monitoring several criteria simultaneously. In particular we combine x-ray diffraction observations with the detection of discontinuities in the optical properties by spectroradiometric measurements. This approach significantly increases the confidence of melt identification, especially with low-Z samples. We demonstrate the method with observations of melt in oxygen at 47 and 55 gigapascals.

Benedetti, L R; Antonangeli, D; Farber, D L; Mezouar, M

2007-11-19T23:59:59.000Z

355

MAAP5 BWR Core Melt Progression Model Enhancement Description  

Science Conference Proceedings (OSTI)

This report describes proposed enhancements to the Modular Accident Analysis Program (MAAP) core melt progression model for BWRs. MAAP is an EPRI-owned and -licensed computer program that simulates the operation of light water and heavy water moderated nuclear power plants for both current and advanced light water reactor (ALWR) designs. The Fukushima accident—the first full-scale accident for a BWR design—poses challenges to the current core model that must be addressed.The ...

2013-02-25T23:59:59.000Z

356

Testing and performance evaluation of T1000G/RS-14 graphite/polycyanate composite materials  

Science Conference Proceedings (OSTI)

The performance of a graphite fiber/polycyanate matrix composite material system, T1000G/RS-14, was evaluated by performing an extensive mechanical property test program. The test program included both static strength and long-term tests for creep, fatigue, and stress rupture. The system was evaluated at both ambient temperature and elevated temperatures. The specimens were machined from composite cylinders that had a unidirectional layup with all the fibers oriented in the hoop direction. The cylinders were fabricated using the wet-filament winding process. In general, the T1000G/RS-14 system demonstrated adequate static strengths for possible aerospace structural applications. The results from the static tests indicated that very high composite hoop tensile strengths can be achieved with this system at both ambient and elevated temperatures as high as 350{degree}F. However, in the long-term testing for compressive creep and tension-tension fatigue the results indicated a lower elevated temperature was required to minimize the risk of using this material system. Additional testing and analysis activities led to the selection of 275{degree}F as the desired temperature for future performance evaluation. Subsequent testing efforts for determining the resin and composite transverse compressive creep responses at 275{degrees}F indicated that excessive creep strain rates may still be a weakness of this system. In the long-term tests, sufficient data was generated from impregnated strand and composite ring stress-life testing, and composite ring tension-tension fatigue to determine failure probabilities for a given set of design requirements. The statistical analyses of the test data, in terms of determining failure probability curves, will be reported on in a separate report. However, it is expected that this material system will have a very low failure probability for stress rupture based on the collected stress-life data. Material responses that will require further investigation and/or possible performance improvements are fiber- direction tension-tension fatigue, and both resin and transverse composite compressive creep. Improvements in the creep performance or dimensional stability of this material system may ultimately depend on the test and/or process environment.

Starbuck, J.M.

1997-01-01T23:59:59.000Z

357

Electrochemical and Solid-State Lithiation of Graphitic C3N4  

Science Conference Proceedings (OSTI)

: Lithiated graphitic carbon n.itride {C3N4 ) was fabricated by electrochemical and solid-state reactions. The addition of Li to C3N4 results in a reaction between the Li and the graphite-like C3N species in C3N4. This irreversible reaction leads to the formation of Li-CH=NR and Li-N=CR2 species, which are detrimental to anode properties. Suitable nitrogen-doped carbon structures for anode applications are predicted to need high concentrations of pyridinic C-N-C terminal bonds and low concentrations of w quaternary C3N species to boost electronic conductivity and reversibly cycle Li ions. 3.5r-- - - -------, Li 25 + 1 5 0.5 KEYWORDS: mrbo11 uilride, lit!Jiatiou, auode, battery Copaoty tmAIVol

Veith, Gabriel M [ORNL; Baggetto, Loic [ORNL; Adamczyk, Leslie A [ORNL; Guo, Bingkun [ORNL; Brown, Suree [ORNL; Sun, Xiao-Guang [ORNL; Albert, Austin A [ORNL; Humble, James R [University of Tennessee, Knoxville (UTK); Barnes, Craig E. [University of Tennessee, Knoxville (UTK); Bojdys, Michael J [University of Liverpool; Dai, Sheng [ORNL; Dudney, Nancy J [ORNL

2013-01-01T23:59:59.000Z

358

Examination of the solidification macrostructure of spheroidal and flake graphite cast irons using DAAS and ESBD  

Science Conference Proceedings (OSTI)

This investigation focuses on the study of the solidification macrostructure of sand cast flake and spheroidal graphite cast irons. The macrostructure is revealed by using a special technique developed earlier by the authors, called Direct Austempering After Solidification. The observations make use of conventional metallography and Electron Back Scattering Diffraction. The latter technique allows a more detailed observation of the morphology of the austenite grains and the microstructure of the matrix. The results of Electron Back Scattering Diffraction validate the observations made using the macrographic technique. It is verified that the solidification of both flake and spheroidal graphite cast irons is dominated by the growth of large austenite dendrites that form a grain pattern similar to that usually found in most metallic alloys.

Rivera, G. [Metallurgy Division INTEMA, National University of Mar del Plata, CONICET, J. B. Justo 4302 (B7608FDQ) Mar del Plata (Argentina); Calvillo, P.R. [Department of Metallurgy and Materials Science, Ghent University (Belgium); Boeri, R. [Metallurgy Division INTEMA, National University of Mar del Plata, CONICET, J. B. Justo 4302 (B7608FDQ) Mar del Plata (Argentina)], E-mail: boeri@fi.mdp.edu.ar; Houbaert, Y. [Department of Metallurgy and Materials Science, Ghent University (Belgium); Sikora, J. [Metallurgy Division INTEMA, National University of Mar del Plata, CONICET, J. B. Justo 4302 (B7608FDQ) Mar del Plata (Argentina)], E-mail: jsikora@fi.mdp.edu.ar

2008-09-15T23:59:59.000Z

359

Electric conductivity and aggregation of anthracite and graphite particles in concretes  

Science Conference Proceedings (OSTI)

A statistical model of the electric conductivity of a heterogeneous system based on coal and a binding agent is presented. In this system, a conductive phase appears because of particle aggregation. The model was tested in the systems of anthracite and graphite in cement stone. The consistency between the experimental and calculated electric conductivities with a correlation coefficient higher than 0.9 was found on a linear interpolation of model parameters. It was found that the presence of a surfactant (cetylpyridinium chloride) and a high-molecular-weight compound (polyvinyl acetate) changed the number of particles in anthracite and graphite aggregates to affect the specific conductivity of the heterogeneous system. 9 refs., 5 figs., 1 tab.

E.A. Fanina; A.N. Lopanov [Belgorod State Technological University, Belgorod (Russian Federation)

2009-02-15T23:59:59.000Z

360

Data Relating to Hanford Mined Graphite (2273-D) Samples Annealed at NAA  

SciTech Connect

On 2/8/1950, there was mined from process tube 2273 in D pile at Hanford a quantity of graphite power, which was expected to show the most extensive radiation damage of any graphite available at that time. A series of samples of this powder were annealed in 100 degrees increments from 100 degrees to 2000 degrees C at this labaoratory. There were returned to Hanford and shipped by them to the National Bureau of Standards for total stored energy measurements. The present memorandum is comprised of a description of the annealing procedure used here, curves giving the detailed annealing history of each sample, and various curves derived from data obtained from these samples at Hanford and at the National Bureau of Standards.

Smith, C.A.; Carter, R.L.

1951-03-15T23:59:59.000Z

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.


361

STABILITY OF METALLIC Si-, Fe-RICH ALLOYS, SiC AND GRAPHITE IN MIXED SUPERNOVA EJECTA.  

E-Print Network (OSTI)

STABILITY OF METALLIC Si-, Fe-RICH ALLOYS, SiC AND GRAPHITE IN MIXED SUPERNOVA EJECTA. L. Grossman1 the Murchison chondrite contain inclusions of TiC and Si-rich metal alloys but, in most cases, no SiC [1], while of TiC, SiC and a Si-rich metal alloy at a higher temperature than graphite when the expanding gas has

Grossman, Lawrence

362

Experimental Determination of the Effect of Reactor Radiation on the Thermal Conductivity of Uranium-Impregnated Graphite  

SciTech Connect

Experiments are described in which the change in thermal conductivity of U-impregnated graphite under neutron irradiation was measured. Thermal resistivities relative to the thermal resistivity of undamaged impregnated graphite are reorted as functions of exposure. From applications of the expermental results to the North American Aviation low-power research reactor the peak tem. of the core is determined for a given reactor power and time of operation.

Hetrick, D.L.; McCarty, W.K.; Steele, G.N.; Brown, M.S.; Clark, E.V.; Holmes, F.R.; Howard, D.F.; McElroy, W.N.; Shields, B.L.

1953-01-06T23:59:59.000Z

363

The Treatment of Mixed Waste with GeoMelt In-Container Vitrification  

SciTech Connect

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

364

Release of Residues from Melting NORM-Contaminated Steel Scrap - A German Approach  

Science Conference Proceedings (OSTI)

As many raw materials like crude oil, natural gas, mineral sands, phosphor ores and others are contaminated by radionuclides from the Uranium and/or Thorium decay chain (NORM), also plants for processing these materials became contaminated during operation. When plants are shut down, large quantities of pipes, valves, pumps and other components have to be scrapped. As scrap yards and steel mills are equipped by large detector systems to avoid an input of radioactivity into the steel cycle, decontamination is required before recycling. Siempelkamp is operating a melting plant for processing NORM and/or chemically/ toxically contaminated steel scrap. Beside the decontaminated steel as output, residues like slag and filter dust have to be managed within the range of licensed values. Based on the European Safety Standard the European member states have to implement radiation exposure from work activities with NORM in their Radiation Protection Ordinances (RPO). The German government revised the RPO in July 2001. Part 3 describes exposure limits for workers and for the public. Exposures from residues management have to meet 1 mSv/year. Brenk Systemplanung has performed calculations for assessing the radiation exposure from residues of the Siempelkamp melting plant. These calculations have been based on the input of metal from different origins and include all relevant exposure pathways in a number of scenarios. The calculations have been based on the dose criterion of 1 mSv/y as required by the German RPO. The methods and results will be presented.

Quade, U.; Thierfeldt, S.; Wvrlen, S.

2003-02-24T23:59:59.000Z

365

Technical and cost analysis of rock-melting systems for producing geothermal wells. [GEOWELL  

DOE Green Energy (OSTI)

The drilling of wells makes up a large fraction of the costs of geothermal energy-extraction plants, and billions of dollars for wells will be needed before geothermal energy is nationally significant. Technical and economic systems studies are summarized regarding the application of the Subterrene concept, i.e., excavating and penetrating rocks or soils by melting, to the production of deep wells such as may be used for dry hot rock or geopressurized geothermal energy-extraction systems. Technically, it was found that Subterrene features are compatible with those of current rotary drilling practices. In fact, some special features could lead to improved well production techniques. These include the buildup of a glass lining along the borehole wall which provides structural resistance to collapse; close control of hole geometry; the existence of a barrier between the drilling fluids and the formations being penetrated; nonrotation; potentially better bit life; and faster rates of penetration in deep, hard rock. A typical optimum-cost well would be rotary-drilled in the upper regions and then rock-melted to total depth. Indicated cost savings are significant: a 30 percent or 3.9 million dollar (1975 $) reduction from rotary-drilled well costs are estimated for a 10-km depth well with a bottom hole temperature of 673 K. Even for relatively cool normal geothermal gradient conditions, the savings for the 1..pi..-km well are estimated as 23 percent of 2.1 million dollars.

Altseimer, J.H.

1976-11-01T23:59:59.000Z

366

Random Isotropic Structures and Possible Glass Transitions in Diblock Copolymer Melts  

E-Print Network (OSTI)

We study the microstructural glass transitions in diblock-copolymer melts using a thermodynamic replica approach. Our approach performs an expansion in terms of the natural smallness parameter -- the inverse of the scaled degree of polymerization, which allows us to systematically study the approach to mean-field behavior as the degree of polymerization increases. We find that in the limit of infinite long polymer chains, both the onset of glassiness and the vitrification transition (Kauzmann temperature) collapse to the mean-field spinodal, suggesting that the spinodal can be regarded as the mean-field signature for glass transitions in this class of systems. We also study the order-disorder transitions (ODT) within the same theoretical framework; in particular, we include the leading-order fluctuation corrections due to the cubic interaction in the coarse-grained Hamiltonian, which has been ignored in previous works on the ODT in block copolymers. We find that the cubic term stabilizes both the ordered (body-centered-cubic) phase and the glassy state relative to the disordered phase. While in melts of symmetric copolymers the glass transition always occurs after the order-disorder transition (below the ODT temperature), for asymmetric copolymers, it is possible that the glass transition precedes the ordering transition.

C. -Z. Zhang; Z. -G. Wang

2005-03-22T23:59:59.000Z

367

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

SciTech Connect

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

368

Diffusion of uranium in H-451 graphite at 900 to 1400/sup 0/C  

SciTech Connect

In this study, the diffusion of uranium (as a stand-in for plutonium) was investigated under conditions approximating those of the primary coolant loop in a High Temperature Gas-Cooled Reactor (HTGR). Profiles were obtained for uranium penetration in H-451 graphite (from the Great Lakes Carbon Company) at temperatures ranging from 900 to 1400/sup 0/C. Diffusion coefficients are established for UO/sub 2/ and UC/sub 2/.

Tallent, O.K.; Wichner, R.P.; Towns, R.L.

1983-03-01T23:59:59.000Z

369

Variation of the magnetic susceptibility of artificial graphite with exposure in the materials testing reactor  

SciTech Connect

The magnetic susceptibility of artificial graphite was determined as a function of exposure in the MTR. Specimens were studied with exposures ranging from 0.07 to 82 {times} 10{sup18} nvt. Fluxes were determined by means of x-ray measurements and resistivity measurements. The dependence of the magnetic susceptibility on exposure in the MTR and also in a Hanford reactor are graphed, and an equivalence factor is calculated.

McCelland, J.D.

1955-02-23T23:59:59.000Z

370

Design guide for category VI reactors: air-cooled graphite reactors  

SciTech Connect

The purpose of this Design Guide is to provide additional guidance to aid the DOE facility contractor in meeting the requirement that the siting, design, construction, modification, operation, maintenance, and decommissioning of DOE-owned air-cooled graphite reactors be in accordance with generally uniform standards, guides, and codes which are comparable to those applied to similar reactors licensed by the Nuclear Regulatory Commission (NRC).

Brynda, W.J.; Karol, R.; Powell, R.W.

1979-02-01T23:59:59.000Z

371

Recapturing Graphite-Based Fuel Element Technology for Nuclear Thermal Propulsion  

SciTech Connect

ORNL is currently recapturing graphite based fuel forms for Nuclear Thermal Propulsion (NTP). This effort involves research and development on materials selection, extrusion, and coating processes to produce fuel elements representative of historical ROVER and NERVA fuel. Initially, lab scale specimens were fabricated using surrogate oxides to develop processing parameters that could be applied to full length NTP fuel elements. Progress toward understanding the effect of these processing parameters on surrogate fuel microstructure is presented.

Trammell, Michael P [ORNL; Jolly, Brian C [ORNL; Miller, James Henry [ORNL; Qualls, A L [ORNL; Harrison, Thomas J [ORNL

2013-01-01T23:59:59.000Z

372

Water is used for many purposes, includ-ing growing crops, producing copper,  

E-Print Network (OSTI)

WATER USES Water is used for many purposes, includ- ing growing crops, producing copper, generating electricity, watering lawns, keeping clean, drinking and recreation. Bal- ancing the water budget comes down of the water budget. Reducing demand involves re- ducing how much water each person uses, lim- iting the number

373

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

SciTech Connect

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

374

CRITICAL EXPERIMENTS ON SLIGHTLY ENRICHED URANIUM METAL FUEL ELEMENTS IN GRAPHITE LATTICES  

SciTech Connect

A series of clean critical experiments was performed in the SGR critical facility utilizing 2 wt% enriched, uranium metal, hollow cylinder, fuel elements in AGOT graphite moderator. Six lattice spacings were used, varying from 6.93 to 16.0 in. on a triangular pitch. Critical loadings and fuel element worths were determined and compared to the results of 4-group diffusion theory. Calculations utilized TEMPEST, S/sub 4/, FORM, and AIM-5 programs on the IBM 7090. The calculated K/sub eff/ compared well with experiments over the full range of moderator-to-fuel volume ratios when using a 2200 m/sec graphite absorption cross section of 4.07 mb. The sensitivity of the calculation to variations in the graphite absorption cross section was examined and the experimental error due to inventory uncertainties was assessed. The differential worths of both the central and peripheral fuel elements were obtained and agreed in general with AIM- 5 calculations. The thermal flux traverse of a unit cell was shown to agree best with a Wilkins' spectrum option of TEMPEST. Details of both the experimental and theoretical methods are given. (auth) The work functions of cesiated and cesium- hydridecoated surfaces are studied. A thermionlc cell for performance analyses is described. Design characteristics of water-cooled and liquid-metal-cooled nuclearthermionic generators for naval power applications are compared. (T.F.H.)

Campbell, R.W.; Doyas, R.J.; Field, H.C.; Guderjahn, C.A.; Guenther, R.L.; Hausknecht, D.E.; Mayer, M.S.; Morewitz, H.A.

1963-06-30T23:59:59.000Z

375

Advanced High-Temperature Reactor for Production of Electricity and Hydrogen: Molten-Salt-Coolant, Graphite-Coated-Particle-Fuel  

DOE Green Energy (OSTI)

The objective of the Advanced High-Temperature Reactor (AHTR) is to provide the very high temperatures necessary to enable low-cost (1) efficient thermochemical production of hydrogen and (2) efficient production of electricity. The proposed AHTR uses coated-particle graphite fuel similar to the fuel used in modular high-temperature gas-cooled reactors (MHTGRs), such as the General Atomics gas turbine-modular helium reactor (GT-MHR). However, unlike the MHTGRs, the AHTR uses a molten salt coolant with a pool configuration, similar to that of the PRISM liquid metal reactor. A multi-reheat helium Brayton (gas-turbine) cycle, with efficiencies >50%, is used to produce electricity. This approach (1) minimizes requirements for new technology development and (2) results in an advanced reactor concept that operates at essentially ambient pressures and at very high temperatures. The low-pressure molten-salt coolant, with its high heat capacity and natural circulation heat transfer capability, creates the potential for (1) exceptionally robust safety (including passive decay-heat removal) and (2) allows scaling to large reactor sizes [{approx}1000 Mw(e)] with passive safety systems to provide the potential for improved economics.

Forsberg, C.W.

2002-02-21T23:59:59.000Z

376

Low-melting point inorganic nitrate salt heat transfer fluid  

DOE Patents (OSTI)

A low-melting point, heat transfer fluid made of a mixture of four inorganic nitrate salts: 9-18 wt % NaNO.sub.3, 40-52 wt % KNO.sub.3, 13-21 wt % LiNO.sub.3, and 20-27 wt % Ca(NO.sub.3).sub.2. These compositions can have liquidus temperatures less than 100 C; thermal stability limits greater than 500 C; and viscosity in the range of 5-6 cP at 300 C; and 2-3 cP at 400 C.

Bradshaw, Robert W. (Livermore, CA); Brosseau, Douglas A. (Albuquerque, NM)

2009-09-15T23:59:59.000Z

377

Method to decrease loss of aluminum and magnesium melts  

SciTech Connect

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

378

CX-005040: Categorical Exclusion Determination  

Energy.gov (U.S. Department of Energy (DOE))

Induction Furnace Melting (Includes Graphite and Mold Prep)CX(s) Applied: B3.6Date: 01/19/2011Location(s): Albany, OregonOffice(s): Fossil Energy, National Energy Technology Laboratory

379

Micropatterning of a Bipolar Plate Using Direct Laser Melting Process  

Science Conference Proceedings (OSTI)

Direct laser melting (DLM) technology has been used to fabricate the micro-pattern of the bipolar plate in a direct methanol fuel cell (DMFC). A suitable approach to enhance the performance of the bipolar plate has been performed to optimize the DLM process. To fabricate the micro pattern, a DLM process with 316L stainless steel powder has been used. For the melted height of 1 mm, the DLM process conditions were optimized such as; laser power of 200 W, scan rate of 36.62 mm/s and the 8-layer structures. To characterize the effect of material type, the bipolar plates of various types were analyzed. In case of the 316L stainless steel DLM patterning, a current density of 297 mA/cm{sup 2} was achieved but the case of the 316L stainless steel plate, 248 mA/cm{sup 2} current density that is lower than that of other materials was achieved. The overall cell performance of 316L stainless steel DLM patterning bipolar plate was better than that of the 316L stainless steel plate. This has significant advantages for the micropatterning using DLM process. The use of 316L stainless steel powder material as micro pattern material will reduce the machining cost as well as volume of the fuel cell stack.

Jang, Jeong-hwan; Joo, Byeong-don; Mun, Sung-min; Moona, Young-hoon [School of Mechanical Engineering/ Engineering Research Center for Net Shape and Die Manufacturing, Pusan National University, Jangjeon-dong, Geumjeong-gu, Busan 609-735 (Korea, Republic of)

2010-06-15T23:59:59.000Z

380

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.


381

Remote Handling Devices for Disposition of Enriched Uranium Reactor Fuel Using Melt-Dilute Process  

SciTech Connect

Remote handling equipment is required to achieve the processing of highly radioactive, post reactor, fuel for the melt-dilute process, which will convert high enrichment uranium fuel elements into lower enrichment forms for subsequent disposal. The melt-dilute process combines highly radioactive enriched uranium fuel elements with deleted uranium and aluminum for inductive melting and inductive stirring steps that produce a stable aluminum/uranium ingot of low enrichment.

Heckendorn, F.M.

2001-01-03T23:59:59.000Z

382

Three-dimensional evaluation of the compression and recovery behavior in a flexible graphite sheet by synchrotron radiation microtomography  

SciTech Connect

The compression and unloading behavior of flexible graphite sheets was investigated using synchrotron radiation microtomography with 1 {mu}m voxel size. The recovery ratio of the flexible graphite sheet was measured accurately by in-situ observation. The three-dimensional strain distribution in the interior of the specimen was obtained using the microstructural tracking method. The inner strain distribution with micrometer scale indicated inhomogeneous deformation. The microstructural tracking analysis revealed that deformation units exist in the flexible graphite sheet. The units seem to deform, affecting the neighboring units with each other. The units had a similar size and shape with compacted exfoliated graphite worms that constitute the flexible graphite sheet. Microscopic deformations during compression and unloading are surely affected by the microstructure of the sheet. Highlights: Black-Right-Pointing-Pointer The compression and recovery behavior was investigated using microtomography. Black-Right-Pointing-Pointer The tracking analysis revealed that deformation units exist in the specimen. Black-Right-Pointing-Pointer Each unit deforms in relation to the neighboring unit.

Kobayashi, M., E-mail: m-kobayashi@me.tut.ac.jp [Department of Mechanical Engineering, Toyohashi University of Technology, Toyohashi, AICHI 441-8580 (Japan); Toda, H. [Department of Mechanical Engineering, Toyohashi University of Technology, Toyohashi, AICHI 441-8580 (Japan); Takeuchi, A.; Uesugi, K.; Suzuki, Y. [Japan Synchrotron Radiation Research Institute, Sayo-gun, HYOGO 679-5198 (Japan)

2012-07-15T23:59:59.000Z

383

Office of Legacy Management Buildings Included on EMS Reports...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Office of Legacy Management Buildings Included on EMS Reports Office of Legacy Management Buildings Included on EMS Reports Office of Legacy Management Buildings Included on EMS...

384

Skin Effect of Hf-Rich Melts and Some Aspects in its Usage for Hf ...  

Science Conference Proceedings (OSTI)

USAGE FOR Hf-CONTAINING. CAST NICKEL- ... of advanced gas turbines. ... were polished by metallo- graphy and then melted by tungsten inert gas(TIG).

385

063 Synthesis and Characterization of New Lead-Free Low Melt ...  

Science Conference Proceedings (OSTI)

063 Synthesis and Characterization of New Lead-Free Low Melt Sealing Glasses ... Powders by Using a Solution Combustion Synthesis in an Air Atmosphere.

386

A Study of the Effect of Electro-Slag Re-Melting Parameters on the ...  

Science Conference Proceedings (OSTI)

melting (VAR). The structural soundness of this intermediate ESR ingot directly affects its resistance against cracking due to thermal stress in the course of VAR ...

387

Coupled Macro-Micro Modeling of the Secondary Melting of Turbine ...  

Science Conference Proceedings (OSTI)

beam heating (EBBM), energy losses by radiation and conduction and latent ... correspondingly smaller on the smaller scales of pilot VAR and. EBBM melts.

388

Investigation of residual stresses in the laser melting of metal powders in additive layer manufacturing.  

E-Print Network (OSTI)

??Laser Melting (LM) is an Additive Layer Manufacturing (ALM) process used to produce three-dimensional parts from metal powders by fusing the material in a layerby-… (more)

Roberts, Ibiye Aseibichin

2012-01-01T23:59:59.000Z

389

Melting Ice and Tangled Nets: Litigation and Conservation Policy in the US, Australia, and Canada  

E-Print Network (OSTI)

Melting Ice and Tangled Nets: Litigation and Conservationare heavily dependent on sea ice for their survival, both asvulnerable to the receding sea ice boundaries predicted to

Shaffer, Robert

2012-01-01T23:59:59.000Z

390

Multiphysics CFD Modeling of a Free Falling Jet during Melt-Blowing ...  

Science Conference Proceedings (OSTI)

Presentation Title, Multiphysics CFD Modeling of a Free Falling Jet during Melt- Blowing Slag Fiberization ... A Micro-Macro Model of a PEM Fuel Cell System.

391

FUEL CYCLE COSTS IN A GRAPHITE MODERATED SLIGHTLY ENRICHED FUSED SALT REACTOR  

SciTech Connect

A fuel cycle economic study has been made for a 315Mwe graphite- moderated slightly enriched fused-salt reactor. Fuel cycle costs of less than 1.5 mills may be possible for such reactors operating on a ten-year cycle even when the fuel is discarded at the end of the cycle. Recovery of the uranium and plutonium at the end of the cycle reduces the fuel cycle costs to approximates 1 mill/kwh. Changes in the waste storage cost, reprocessing cost or salt inventory have a relatively minor effect on fuel cycle costs. (auth)

Guthrie, C.E.

1959-01-01T23:59:59.000Z

392

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

SciTech Connect

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

393

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

SciTech Connect

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

394

Performance of Lithium Ion Cell Anode Graphites Under Various Cycling Conditions  

Science Conference Proceedings (OSTI)

Graphites MCMB-2810 and OMAC-15 (made by Osaka Gas Inc.), and SNG12 (Hydro Quebec, Inc.) were evaluated (in coin cells with lithium counter electrodes) as anode materials for lithium-ion cells intended for use in hybrid electric vehicles. Though the reversible capacity obtained for SNG was slightly higher than that of OMAC or MCMB, its 1st cycle efficiency was lower. Voltage vs capacity plots of cycling data show that the discharge and charge limits shift to higher capacity values due to continuation of anode side reactions. Varying the cycle charge and discharge limits was found to have no significant effect on fractional capacity shift per cycle.

Ridgway, Paul; Zheng, Honghe; Liu, Gao; Song, Xiangun; Guerfi, Abdelbast; Charest, Patrick; Zaghib, Karim; Battaglia, Vincent

2009-06-15T23:59:59.000Z

395

Possible Diamond-Like Nanoscale Structures Induced by Slow Highly-Charged Ions on Graphite (HOPG)  

Science Conference Proceedings (OSTI)

The interaction between slow highly-charged ions (SHCI) of different charge states from an electron-beam ion trap and highly oriented pyrolytic graphite (HOPG) surfaces is studied in terms of modification of electronic states at single-ion impact nanosizeareas. Results are presented from AFM/STM analysis of the induced-surface topological features combined with Raman spectroscopy. I-V characteristics for a number of different impact regions were measured with STM and the results argue for possible formation of diamond-like nanoscale structures at the impact sites.

Sideras-Haddad, E.; Schenkel, T.; Shrivastava, S.; Makgato, T.; Batra, A.; Weis, C. D.; Persaud, A.; Erasmus, R.; Mwakikunga, B.

2009-01-06T23:59:59.000Z

396

Energy Saving Melting and Revert Reduction Technology: Innovative Semi-Solid Metal (SSM) Processing  

Science Conference Proceedings (OSTI)

Semi-solid metal (SSM) processing has emerged as an attractive method for near-net-shape manufacturing due to the distinct advantages it holds over conventional near-net-shape forming technologies. These advantages include lower cycle time, increased die life, reduced porosity, reduced solidification shrinkage, improved mechanical properties, etc. SSM processing techniques can not only produce the complex dimensional details (e.g. thin-walled sections) associated with conventional high-pressure die castings, but also can produce high integrity castings currently attainable only with squeeze and low-pressure permanent mold casting processes. There are two primary semi-solid processing routes, (a) thixocasting and (b) rheocasting. In the thixocasting route, one starts from a non-dendritic solid precursor material that is specially prepared by a primary aluminum manufacturer, using continuous casting methods. Upon reheating this material into the mushy (a.k.a. "two-phase") zone, a thixotropic slurry is formed, which becomes the feed for the casting operation. In the rheocasting route (a.k.a. "slurry-on-demand" or "SoD"), one starts from the liquid state, and the thixotropic slurry is formed directly from the melt via careful thermal management of the system; the slurry is subsequently fed into the die cavity. Of these two routes, rheocasting is favored in that there is no premium added to the billet cost, and the scrap recycling issues are alleviated. The CRP (Trade Marked) is a process where the molten metal flows through a reactor prior to casting. The role of the reactor is to ensure that copious nucleation takes place and that the nuclei are well distributed throughout the system prior to entering the casting cavity. The CRP (Trade Marked) has been successfully applied in hyper-eutectic Al-Si alloys (i.e., 390 alloy) where two liquids of equal or different compositions and temperatures are mixed in the reactor and creating a SSM slurry. The process has been mostly used for hypo-eutectic Al-Si alloys (i.e., 356, 357, etc.) where a single melt passes through the reactor. In addition, the CRP (Trade Marked) was designed to be flexible for thixocasting or rheocasting applications as well as batch or continuous casting. Variable heat extraction rates can be obtained by controlling either the superheat of the melt, the temperature of the channel system, or the temperature of the reactor. This program had four main objectives all of which were focused on a mechanistic understanding of the process in order to be able to scale it up, to develop it into a robust process,and for SSM processing to be commercially used.

Diran Apelian

2012-08-15T23:59:59.000Z

397

Ordered water structure at hydrophobic graphite interfaces observed by 4D, ultrafast  

E-Print Network (OSTI)

ice-substrate structure and dynamics nonequilibrium phase transition Water at interfaces femtosecond pulse, the interfacial ice assembly goes through nonequilibrium phase transformation point'' in the diffraction profiles. The ice ``melting'' time is 10 ps and the new phase grows in 20 ps

La Rosa, Andres H.

398

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

Science Conference Proceedings (OSTI)

Here we report that poly(diallyldimethylammonium chloride) (PDDA) acts as both a reducing agent and a stabilizer to prepare soluble graphene nanosheets from graphite oxide. The results of transmission electron microscopy, X-ray diffraction, X-ray photoeletron spectroscopy, atomic force microscopy, and fourier transform infrared indicated that graphite oxide was successfully reduced to graphene nanosheets which exhibited single-layer structure and high dispersion in various solvents. The reaction mechanism for PDDA-induced reduction of exfoliated graphite oxide was proposed. Furthermore, PDDA facilitated the in-situ growth of highly-dispersed Pt nanoparticles on the surface of graphene nanosheets to form Pt/graphene nanocomposites, which exhibited excellent catalytic activity towards formic acid oxidation. This work presents a facile and environmentally friendly approach to the synthesis of graphene nanosheets, opens up new possibility for preparing graphene and graphene-based nanomaterials for large-scale applications.

Zhang, Sheng; Shao, Yuyan; Liao, Honggang; Engelhard, Mark H.; Yin, Geping; Lin, Yuehe

2011-03-22T23:59:59.000Z

399

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

NLE Websites -- All DOE Office Websites (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,

400

Experimental study of the fragmentation and quench behavior of corium melts in water  

DOE Green Energy (OSTI)

The interaction of molten core materials with water has been investigated for the pour stream mixing mode. This interaction plays a crucial role during the later stages of in-vessel core melt progression inside a light water reactor such as during the TMI-2 accident. The key issues which arise during the molten core relocation include: (1) the thermal attack and possible damage to the RPV lower head from the impinging molten fuel stream and/or the debris bed, (2) the molten fuel relocation pathways including the effects of redistribution due to core support structure and the reactor lower internals, (3) the quench rate of the molten fuel through the water in the lower plasma, (4) the steam generation and hydrogen generation during the interaction, (5) the transient pressurization of the primary system, and (6) the possibility of a steam explosion. In order to understand these issues, a series of six experiments (designated CCM-1 through -6) was performed in which molten corium passed through a deep pool of water in a long, slender pour stream mode. Results discussed include the transient temperatures and pressures, the rate and magnitude of steam/hydrogen generation, and the posttest debris characteristics. 9 refs., 29 figs.

Wang, S.K.; Blomquist, C.A.; Spencer, B.W.; McUmber, L.M.; Schneider, J.P. (Argonne National Lab., IL (USA); Illinois Univ., Urbana, IL (USA). Dept. of Nuclear Engineering)

1989-01-01T23:59:59.000Z

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.


401

A SODIUM-GRAPHITE REACTOR STEAM-ELECTRIC STATION FOR 75 MEGAWATTS NET GENERATION  

SciTech Connect

The major design features, nuclear characteristics and performance data for a nuclear fueled central station power plant of 75,000 kw net capacity are presented. The heat source is a Na cooled graphite moderated reactor. The design of the reactor takes full advantage of the experience gained to date on the Sodium Reactor Experiment (SRE); the plant described here is a straightforward extension of the smaller experimental SRE, which is now under construction. The fuel elements are made up of rod clusters and the moderator is in the form of Zr canned graphite elements. The performance of the reactor has been based on conservative temperatures and coolant flow velocities which result in a plant with "built-in reserve." Thus, as experience is gained and anticipated improvements in reactor fuel elements and construction materials are proven, the performance of the plant can be increased accordingly. Two reactor designs are described, one for operation with slightly enriched U fuel elements and the other for operation with Th--U fuel elements. The associated heat exchangers, pumps, steam, and electrical generating equipment are identical for either reactor design. An analysis of turbine cycles describes the particular cycle chosen for initial operation and discusses a method by which modern central station performance can be initially obtained. The design and performance data which are required to enable reliable estimates of the plant construction and operating costs to be made are established. (auth)

Weisner, E.F.; Sybert, W.M.

1955-03-22T23:59:59.000Z

402

Graphite and Beryllium Reflector Critical Assemblies of UO2 (Benchmark Experiments 2 and 3)  

SciTech Connect

INTRODUCTION A series of experiments was carried out in 1962-65 at the Oak Ridge National Laboratory Critical Experiments Facility (ORCEF) for use in space reactor research programs. A core containing 93.2 wt% enriched UO2 fuel rods was used in these experiments. The first part of the experimental series consisted of 252 tightly-packed fuel rods (1.27-cm triangular pitch) with graphite reflectors [1], the second part used 252 graphite-reflected fuel rods organized in a 1.506-cm triangular-pitch array [2], and the final part of the experimental series consisted of 253 beryllium-reflected fuel rods in a 1.506-cm-triangular-pitch configuration and in a 7-tube-cluster configuration [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. All three experiments in the series have 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]. The evaluation of the first experiment in the series was discussed at the 2011 ANS Winter meeting [6]. The evaluations of the second and third experiments are 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 [7].

Margaret A. Marshall; John D. Bess

2012-11-01T23:59:59.000Z

403

Feasibility of monitoring the strength of HTGR core support graphite: Part III  

Science Conference Proceedings (OSTI)

Methods are being developed to monitor, in-situ, the strength changes of graphite core-support components in a High-Temperature Gas-Cooled Reactor (HTGR). The results reported herein pertain to the development of techniques for monitoring the core-support blocks; the PGX graphite used in these studies is the grade used for the core-support blocks of the Fort St. Vrain HTGR, and is coarser-grained than the grades used in our previous investigations. The through-transmission ultrasonic velocity technique, developed for monitoring strength of the core-support posts, is not suitable for use on the core-support blocks. Eddy-current and ultrasonic backscattering techniques have been shown to be capable of measuring the density-depth profile in oxidized PGX and, combined with a correlation of strength versus density, could yield an estimate of the strength-depth profile of in-service HTGR core support blocks. Correlations of strength versus density and other properties, and progress on the development of the eddy-current and ultrasonic backscattering techniques are reported.

Morgan, W.C.; Davis, T.J.; Thomas, M.T.

1983-02-01T23:59:59.000Z

404

Dynamic melt rate control on a Laboratory scale VAR furnace without load cell feedback  

SciTech Connect

Based on a linearized version of an accurate, low order, dynamic melt rate model, a feedback melt rate controller was designed and tested on a small VAR furnace at Los Alamos National Laboratory. Model based control was necessary because the furnace is not equipped with a working load cell transducer. The model was incorporated into a process filter that produces estimates of electrode thermal boundary layer, electrode gap, electrode position and electrode mass. Estimated values for the thermal boundary layer and electrode gap were used for feedback. The input commands were melting current and electrode drive speed. A test melt was performed wherein a 0.127 m diameter 304SS electrode was melted into 0.165 m diameter ingot at a nominal melt rate of 27 g/s. Toward the end of the test, a melt rate step up to 32 g/s was commanded. The controller initiated a nonlinear current ramp to produce the commanded step. Electrode position data were analyzed and the results used to determine that the actual melt rate profile followed the commanded profile relatively well.

Beaman, Joseph J.; Melgaard, d; Shelmidine, G. J. (Gregory J.); Tubesing, P. K. (Philip K.); Aikin, R. M. (Robert M.); Williamson, R. L. (Rodney L.)

2001-01-01T23:59:59.000Z

405

The anisotropic free energy of the Lennard-Jones crystal-melt interface James R. Morris  

E-Print Network (OSTI)

The anisotropic free energy of the Lennard-Jones crystal-melt interface James R. Morris Metal; accepted 22 May 2003 We have calculated the free energy of the crystal-melt interface for the Lennard are in good agreement with previous calculations of the free energies, based upon simulations used

Song, Xueyu

406

Application of Dual-Polarization Radar Melting-Layer Detection Algorithm  

Science Conference Proceedings (OSTI)

A polarimetric melting-layer detection algorithm developed for an S-band radar has been modified for use by the King City C-band radar in southern Ontario, Canada. The technique ingests radar scan volume data to determine the melting-layer top ...

S. Boodoo; D. Hudak; N. Donaldson; M. Leduc

2010-08-01T23:59:59.000Z

407

Heat Transfer Analysis of Asphalt Concrete Pavement Based on Snow Melting  

Science Conference Proceedings (OSTI)

On the basis of Wuhan district weather conditions of January 5, 2010, heat transfer mechanism of Beijing-Zhuhai Expressway Hubei section of asphalt concrete pavement based on snow melting is analyzed and the model of heat transmission is established. ... Keywords: asphalt concrete pavement, ground-source heat, pump, deicing and snow melting, heat flux

Yan-ping Tu; Jie Li; Chang-sheng Guan

2010-06-01T23:59:59.000Z

408

A Simplified Ice–Ocean Coupled Model for the Antarctic Ice Melt Season  

Science Conference Proceedings (OSTI)

In the Antarctic Ocean, sea ice melts mostly by warming of the ocean mixed layer through heat input (mainly solar radiation) in open water areas. A simplified ice–upper ocean coupled model is proposed in which sea ice melts only by the ocean heat ...

Kay I. Ohshima; Sohey Nihashi

2005-02-01T23:59:59.000Z

409

Numerical simulation of melting in two-dimensional cavity using adaptive grid  

Science Conference Proceedings (OSTI)

This paper presents a numerical simulation of melting of chemically pure material in two-dimensional square cavity. A single-domain model is used which does not require interface tracking and allows the use of a fixed grid in order to solve governing ... Keywords: adaptive moving grid, grid generation, melting

Jure Mencinger

2004-07-01T23:59:59.000Z

410

Melting curve and Hugoniot of molybdenum up to 400 GPa by ab initio simulations  

E-Print Network (OSTI)

with the high pressure melting curve from static compression experiments. Our calculated P(V ) and T(P) Hugoniot on new ab initio calculations of Tm(P) for Mo, and on the P(V ) and T(P) relations on the Hugoniot. We it to calculate melting curves. In such calculations, no empirical model is used to describe the interactions

Alfè, Dario

411

Gallium arsenide thin films on tungsten/graphite substrates. Phase II. Quarterly project report No. 2, December 1, 1977-February 28, 1978  

DOE Green Energy (OSTI)

The objectives of this contract are to investigate thin films of gallium arsenide on tungsten/graphite substrates and to prepare solar cells with an AM1 efficiency of 6% or higher by August 1978. Efforts during this quarter have been directed to: (1) the deposition and characterization of gallium arsenide films on tungsten/graphite substrates by the arsenic and arsine processes, (2) the construction and operation of an apparatus for the deposition of titanium dioxide films, and (3) the fabrication and evaluation of MOS solar cells on tungsten/graphite substrates. Gallium arsenide films have been deposited on tungsten/graphite substrates by the reaction of gallium, hydrogen chloride, and arsenic in a hydrogen flow. The structural and electrical properties of these films are very similar to those obtained by the arsine process. The initial stage of the deposition of gallium arsenide films on tungsten/graphite substrates has been investigated by the scanning electron microscopy.

Chu, S.S.

1978-03-01T23:59:59.000Z

412

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

413

Percentage of Total Natural Gas Residential Deliveries included...  

Gasoline and Diesel Fuel Update (EIA)

City Gate Price Residential Price Percentage of Total Residential Deliveries included in Prices Commercial Price Percentage of Total Commercial Deliveries included in Prices...

414

Property:Number of Plants included in Capacity Estimate | Open...  

Open Energy Info (EERE)

of Plants included in Capacity Estimate Jump to: navigation, search Property Name Number of Plants included in Capacity Estimate Property Type Number Retrieved from "http:...

415

Natural Gas Deliveries to Commercial Consumers (Including Vehicle ...  

U.S. Energy Information Administration (EIA)

Natural Gas Deliveries to Commercial Consumers (Including Vehicle Fuel through 1996) in Wisconsin (Million Cubic Feet)

416

The IMPROVE-1 Storm of 1–2 February 2001. Part IV: Precipitation Enhancement across the Melting Layer  

Science Conference Proceedings (OSTI)

Previous model simulations indicate that in stratiform precipitation, the precipitation rate can increase by 7% in the melting layer through direct condensation onto melting snow and the resultant cooled rain. In the present study, a model ...

Christopher P. Woods; John D. Locatelli; Mark T. Stoelinga

2008-03-01T23:59:59.000Z

417

Round-Robin Study of Methods for Trace Metal Analysis: Graphite Furnace Atomic Absorption Spectroscop-Cadmium, Arsenic and Chromium  

Science Conference Proceedings (OSTI)

Eighteen utility laboratories evaluated graphite furnace atomic absorption spectroscopy (GFAAS) methods for measuring cadmium, arsenic and chromium in a variety of utility aqueous streams. This EPRI Tailored Collaboration Project, part of the ongoing Analytical Methods Qualification (AMQ) program, will help utilities define reasonable pollutant discharge limits and effluent monitoring requirements.

1997-12-05T23:59:59.000Z

418

Modeling lithium diffusion in nickel composite graphite Venkat R. Subramanian, Ping Yu, Branko N. Popov, Ralph E. White*  

E-Print Network (OSTI)

Modeling lithium diffusion in nickel composite graphite Venkat R. Subramanian, Ping Yu, Branko N. Exchange current and diffusion coef®cient for the lithium-diffusion are predicted. # 2001 Elsevier Science computers, and camcorders. The distinguished feature of lithium-ion batteries is the use of intercalation

Popov, Branko N.

419

Carbyne contamination in carbon-coated TEM microgrids made from vacuum-resistive heating deposition from a graphite rod  

Science Conference Proceedings (OSTI)

Carbyne contamination was found to exist on the as-prepared carbon-coated transmission electron microscope (TEM) microgrids made by the method of vacuum-resistive heating deposition from a graphite rod. It is a source to bring mistaken and confusing information to the samples being studied by TEM.

Li Hanying; Sun Jingzhi; Wang Youwen; Chen Hongzheng; Cao Jian; Wang Mang

2004-03-15T23:59:59.000Z

420

Carbothermal reduction growth of ZnO nanostructures on sapphire-comparisons between graphite and activated charcoal powders  

Science Conference Proceedings (OSTI)

Zinc oxide (ZnO) nanostructures were grown by the vapour phase transport (VPT) method on a-plane sapphire substrates via carbothermal reduction of ZnO powders with various carbon powders. Specifically, graphite powder and activated charcoal powder (of ... Keywords: Growth, Nanostructures, ZnO

M. Biswas; E. McGlynn; M. O. Henry

2009-02-01T23:59:59.000Z

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.


421

Temperature programed desorption of C{sub 2}H{sub 4} from pure and graphite-covered Pt(111)  

Science Conference Proceedings (OSTI)

Ethylene adsorption on Pt(111) at 95 K was studied by temperature programed desorption (TPD), low energy electron diffraction (LEED), and x-ray photoelectron spectroscopy. Ethylene desorbs reversibly at 112 K and irreversibly at 255 and 280 K. It is generally accepted that annealing of ethylene adsorbed on Pt(111) to 300 K results in a dehydrogenation to ethylidyne through an ethylidene intermediate. This was observed by a hydrogen desorption peak at 300 K. Also, hydrogenation of the adsorbed ethylene was observed by a small ethane desorption peak at 300 K. Upon heating to 700 K, the ethylidyne species will further dehydrogenate to carbidic carbon species with hydrogen desorption peaks at 460 and 640 K. If the carbidic species is heated to higher temperatures (up to 1000 K), it will further dehydrogenate and form graphitic islands which will accumulate by Ostwald ripening in larger islands at the step edges of the surface. After annealing the sample to 1000 K, a statistically distributed 8x8 superstructure of these graphite islands is achieved, as interpreted from A pattern in the LEED data. The TPD results indicate that ethylene adsorption on Pt(111) results in the formation of graphitic islands upon heating to 1000 K, contrary to previous conjectures of formation of a full graphite monolayer.

Vermang, B.; Juel, M.; Raaen, S. [Physics Department, Norwegian University of Science and Technology (NTNU), N-7491 Trondheim (Norway)

2007-11-15T23:59:59.000Z

422

An analytical and numerical model to determine stresses in a Rock Melt Drill produced glass liner for potential use on Mars  

E-Print Network (OSTI)

A numerical and analytical model was constructed to determine the resultant stress state imposed on a Rock Melt Drill produced liner. The purpose of this study was to determine if the liner produced would possess the strength required to prevent a failure in the borehole wall. Derivation of energy, mass and momentum conservation equations was performed to aid in the identification of applicable loads acting on the melted material that will form the liner. A finite difference model was coded to produce a temperature profile in the liner thickness. An analytical stress model, using the results of the derived equations and the numerical thermal model, was constructed to determine the magnitude of the stresses the liner is subjected to after operation of the Rock Melt Drill. By using values from the Rock Melt Drill design and formation material properties taken from the literature, from experiment and through calculations, a baseline resultant stress was able to be determined for the liner. Utilizing the thermal and stress model, a parametric analysis of the stresses and temperature profile was conducted over a range of Rock Melt Drill operational parameters and formation material property parameters. This parametric analysis was conducted to determine trends between the above parameters and the resultant temperature and stress profiles. It was determined that the liner would have enough strength to prevent failure by collapse up to the required depths of 5 km, under ideal conditions. Additional loads applied to the liner in the form of an increase pressure gradient or formation fluid load may be enough to cause collapse of the liner. Also, the resultant tensile stress in the liner at shallow depths is great enough to cause crack propagation near the surface. It is a conclusion of this study that the Rock Melt Drill may be a potentially viable drilling system for use on Mars, in terms of preventing borehole collapse. Further study is necessary to determine the state of the liner in more realistic conditions, such as including pressurized fluids in the models, and additional work is needed to optimize the Rock Melt Drill system.

McConnell, Joshua B

2000-01-01T23:59:59.000Z

423

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

424

Melt Infiltrated Ceramic Composites (Hipercomp) for Gas Turbine Engine Applications  

DOE Green Energy (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

425

Preferential orientation of Te precipitates in melt-grown CZT  

Science Conference Proceedings (OSTI)

Cadmium zinc telluride (Cd1-xZnxTe or CZT) has proved to be a useful material for semiconductor gamma-ray spectrometers and other electro-optic devices. It is often grown Te-rich to optimize its electrical characteristics, but this off-stoichiometric growth leads to the formation of semimetallic Te precipitates in the semiconducting host crystal. These precipitates can impair device performance and their formation needs to be inhibited, if possible, during growth. Characterization of melt-grown CZT has shown that Te precipitates are often faceted. In this study, characterization of several particles of different shapes revealed that most of the Te precipitates were preferentially oriented with the {101}CZT||{-12-10}Te . A secondary orientation relationship was also observed as {11-1}CZT||{01-11}Te for one of the {111}CZT family of planes. One of the particles exhibited {110}CZT||{01-10}Te and {001}CZT||{0001}Te . Precipitates were often found on {111}CZT twin boundaries and, in these cases, it was possible to assign specific orientations with respect to the twin plane. The expected orientation of the {0001}-plane of Te aligned with the {111}-plane of CZT was not observed even though a good lattice match is predicted in ab initio models. Observations of strained and polycrystalline Te precipitates are also discussed with relevance to the ab initio model and to impacts on electronic properties.

Henager, Charles H.; Edwards, Danny J.; Schemer-Kohrn, Alan L.; Bliss, Mary; Jaffe, John E.

2009-05-18T23:59:59.000Z

426

Graphite Modular Reactor with Cooled Metal Core Outlet End Support Plate  

SciTech Connect

The modular designs appear attractive in that the reactor core lateral support is provided by the modules themselves rather than externally as with a bundled core. Types B and C provide a means of reducing the inter-element and intermodular leakage flow. This tends to enhance the reliability of the reactor core by decreasing the probability of a progressive overall failure of the core initiated by a mid-core rupture of one of the fuel elements. The graphite inner reflector and lateral support mechnism are eliminated in this design. The assembly of the modular core design is probably simplified by the smaller number of modular elements to be handled and by the elimination of the lateral support mechanism. The modular core has several potential problem areas which will be examined by further analysis and testing.

Jackson, L.

1963-08-01T23:59:59.000Z

427

A new diamond biosensor with integrated graphitic microchannels for detecting quantal exocytic events from chromaffin cells  

E-Print Network (OSTI)

The quantal release of catecholamines from neuroendocrine cells is a key mechanism which has been investigated with a broad range of materials and devices, among which carbon-based materials such as carbon fibers, diamond-like carbon, carbon nanotubes and nanocrystalline diamond. In the present work we demonstrate that a MeV-ion-microbeam lithographic technique can be successfully employed for the fabrication of an all-carbon miniaturized cellular bio-sensor based on graphitic micro-channels embedded in a single-crystal diamond matrix. The device was functionally characterized for the in vitro recording of quantal exocytic events from single chromaffin cells, with high sensitivity and signal-to-noise ratio, opening promising perspectives for the realization of monolithic all-carbon cellular biosensors.

Picollo, Federico; Vittone, Ettore; Pasquarelli, Alberto; Carbone, Emilio; Olivero, Paolo; Carabelli, Valentina

2013-01-01T23:59:59.000Z

428

Crystal structure of graphite under room-temperature compression and decompression  

Science Conference Proceedings (OSTI)

Recently, sophisticated theoretical computational studies have proposed several new crystal structures of carbon (e.g., bct-C{sub 4}, H-, M-, R-, S-, W-, and Z-carbon). However, until now, there lacked experimental evidence to verify the predicted high-pressure structures for cold-compressed elemental carbon at least up to 50 GPa. Here we present direct experimental evidence that this enigmatic high-pressure structure is currently only consistent with M-carbon, one of the proposed carbon structures. Furthermore, we show that this phase transition is extremely sluggish, which led to the observed broad x-ray diffraction peaks in previous studies and hindered the proper identification of the post-graphite phase in cold-compressed carbon.

Wang, Yuejian; Panzik, Joseph E.; Kiefer, Boris; Lee, Kanani K.M. (Yale); (New Mexico State)

2012-10-23T23:59:59.000Z

429

A SODIUM COOLED, GRAPHITE MODERATED, LOW ENRICHMENT URANIUM REACTOR FOR THE PRODUCTION OF USEFUL POWER  

SciTech Connect

A design study is presented for a sodium cooled, graphite moderated power reactor utilizing low enrichment uranium fuel. The design is characterized by dependence on existing technology and the use of standard, or nearly standard, components. The reactor has a nominal rating of 167 thermal megawatts, and a plant comprising three such reactors for a total output of 500 thermal megawatts is described. Sodium in a secondary, non-radioactive, circulation system carries the heat to a steam generator at 910 deg F and is returned at 420 deg F. Steam conditions at the turbine throttle are 600 psig and 825 deg F. Cost of the complete reactor power plant, consisting of the three reactors and one 150- megawatt turbogenerator, is estimated to be approximately ,165,000. (auth)

Weisner, E.F. ed.

1954-09-15T23:59:59.000Z

430

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, Zane L. (Lenoir City, TN); Benton, Samuel T. (Knoxville, TN)

1988-01-01T23:59:59.000Z

431

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

432

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.

1988-11-22T23:59:59.000Z

433

LiFePO{sub 4}/gel/natural graphite cells for the BATT program  

DOE Green Energy (OSTI)

LiFePO{sub 4}/gel/natural graphite (NG) cells have been prepared and cycled under a fixed protocol for cycle and calendar life determination. Cell compression of 10 psi was found to represent an optimal balance between cell impedance and the first cycle losses on the individual electrodes with the gel electrolyte. Cells with a Li anode showed capacities of 160 and 78 mAh/g-LiFePO{sub 4} for C/25 and 2C discharge rates, respectively. Rapid capacity and power fade were observed in the LiFePO{sub 4}/gel/NG cells during cycling and calendar life studies. Diagnostic evaluations point to the consumption of cycleable Li though a side reaction as the reason for performance fade with minimal degradation of the individual electrodes.

Striebel, K.; Guerfi, A.; Shim, J.; Armand, M.; Gauthier, M.; Zaghib, K.

2002-10-29T23:59:59.000Z

434

Melting of low-level radioactive non-ferrous metal for release  

SciTech Connect

Siempelkamp Nukleartechnik GmbH has gained lots of experience from melting ferrous metals for recycling in the nuclear cycle as well as for release to general reuse. Due to the fact that the world market prices for non-ferrous metals like copper, aluminium or lead raised up in the past and will remain on a high level, recycling of low-level contaminated or activated metallic residues from nuclear decommissioning becomes more important. Based on the established technology for melting of ferrous metals in a medium frequency induction furnace, different melt treatment procedures for each kind of non-ferrous metals were developed and successfully commercially converted. Beside different procedures also different melting techniques such as crucibles, gas burners, ladles etc. are used. Approximately 340 Mg of aluminium, a large part of it with a uranium contamination, have been molten successfully and have met the release criteria of the German Radiation Protection Ordinance. The experience in copper and brass melting is based on a total mass of 200 Mg. Lead melting in a special ladle by using a gas heater results in a total of 420 Mg which could be released. The main goal of melting of non-ferrous metals is release for industrial reuse after treatment. Especially for lead, a cooperation with a German lead manufacturer also for recycling of non releasable lead is being planned. (authors)

Quade, Ulrich; Kluth, Thomas; Kreh, Rainer [Siempelkamp Nukleartechnik GmbH (Germany)

2007-07-01T23:59:59.000Z

435

Cladding hull decontamination and densification process. Part 2. Densification by inductoslag melting  

Science Conference Proceedings (OSTI)

The Inductoslag melting process was developed to densify Zircaloy-4 cladding hulls. It is a cold crucible process that uses induction heating, a segmented water-cooled copper crucible, and a calcium fluoride flux. Metal and flux are fed into the furnace through the crucible, located at the top of the furnace, and the finished ingot is withdrawn from the bottom of the furnace. Melting rates of 40 to 50 kg/h are achieved, using 100 to 110 kW at an average energy use of 2.5 kWh/kg. The quality of ingots produced from factory supplied cladding tubing is sufficient to satisfy nuclear grade standards. An ingot of Zircaloy-4, made from melted cladding tubing that had been autoclaved to near reactor exposure and then descaled by the hydrogen fluoride decontamination process prior to Inductoslag melting, did not meet nuclear grade standards because the hydrogen, nitrogen, and hardness levels were too high. Melting development work is described that could possibly be used to test the capability of the Inductoslag process to satisfactorily melt a variety and mix of materials from LWR reprocessing, decontamination, and storage options. Results of experiments are also presented that could be used to improve remote operation of the melting process.

Nelson, R.G.; Montgomery, D.R.

1980-04-01T23:59:59.000Z

436

The melting layer: The radar bright band is dark for lidar  

E-Print Network (OSTI)

Measurements of the melting layer were made with radar and lidar, during light rain. At the height at which a weather radar sees a bright band, the backscatter from the lidar has a minimum. Sometimes this minimum is more than 20 dB deep relative to the rain underneath. In this paper the measurements will be analysed in detail. Five mechanisms that can contribute to this effect are discussed: 1. Refractive index change during melting; 2. Aggregation and breakup; 3. Structural collapse of the melting snowflake; 4. Enhanced vertical backscatter of water droplets; 5. The orientation and shape of the melting crystals. Keywords: radar, cloud radar, lidar, melting layer, orientation of crystals. 1. Introduction In the Netherlands stratiform rain is mainly produced by the melting of ice particles into rain droplets. Normally this happens in a well-defined layer, just below the zero degree level. This melting layer is characterised by high radar reflections, the so-called bright band. This b...

V. K. C. Venema; H. W. J. Russchenberg; A van Lammeren; A. Apituley; L.P. Ligthart; Royal Netherl; S Meteorological Organisation

1998-01-01T23:59:59.000Z

437

Anisotropic Interfacial Free Energies of the Hard-Sphere Crystal-Melt Interfaces Yan Mu, Andrew Houk, and Xueyu Song*  

E-Print Network (OSTI)

Anisotropic Interfacial Free Energies of the Hard-Sphere Crystal-Melt Interfaces Yan Mu, Andrew-melt interfacial free energy calculations using capillary wave approach. Using this method, we have calculated the free energies of the fcc crystal-melt interfaces for the hard-sphere system as a function of crystal

Song, Xueyu

438

SAFEGUARD REPORT ON THE PROPOSED METHOD OF ANNEALING GRAPHITE IN THE X-10 REACTOR  

SciTech Connect

gone approximately 16 years of almost continuous irradiation. Throughout this time stored energy has accumulated at a slow rate to the present maximum value of about 35 cal/gm releasable to 250 deg C. A small portion of the moderator (approximately 4%) contains stored energy which under adiabatic conditions may be released spontaneously (at approximately 165 deg C) to produce a maximum temperature of 270 deg C. Careful analysis has shown that the presert condition is not hazardous; however, it appears wise at this time to initiate some corrective action (thermal annealing) to prevent the continued buildup of stored energy to a dangerously high value. Several methode of obtaining effective annealing in the OGR were investigated. The proposed method was selected upon the basis of convenience, over-all safety, effectiveness, and cost. The proposed method involves the alteration of the present coolant flow system to permit reversal of air flow through the fuel channels. This will result in a reversed temperature distribution wherein the maximum graphite temperature will occur in the normally cold, maximum-stored-energy region of the moderator, Such an arrangement permits an annealing operation to be performed under conditions very similar to those of the normal safe operation. The proposed procedure re quires a slow heatup of the moderator under full reversed, air-flow conditions. This can be accomplished by slowly raising the reactor nuclear power level until the desired graphite temperature is attained. During the initial stages of the operation the stored energy will be reduced to a sufficiently low value that spontaneous energy release is no longer possible. This can be accomplished at temperatures (less than 140 deg C) well below the minimum (165 deg C) required for spontaneous energy release. Subsequent higher temperature may then be employed to further reduce the stored energy. Recurrence of stored energy which may be released spontaneously can be prevented by periodic annealing at rather infrequent intervals. (auth)

Stanford, L.E.; Wittels, M.C.; Ramsey, M.E.; Cagle, C.D.

1960-05-18T23:59:59.000Z

439

Energy Saving Melting and Revert Reduction Technology: Improved Die Casting Process to Preserve the Life of the Inserts  

Science Conference Proceedings (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

440

Energetics of a Symmetric Circulation Including Momentum Constraints  

Science Conference Proceedings (OSTI)

A theory of available potential energy (APE) for symmetric circulations, which includes momentum constraints, is presented. The theory is a generalization of the classical theory of APE, which includes only thermal constraints on the circulation. ...

Sorin Codoban; Theodore G. Shepherd

2003-08-01T23:59:59.000Z

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.


441

Guam Refinery Thermal Cracking/Other (including Gas Oil ...  

U.S. Energy Information Administration (EIA)

Guam Refinery Thermal Cracking/Other (including Gas Oil) Downstream Charge Capacity as of January 1 (Barrels per Stream Day)

442

Scheduling optimization of a real flexible job shop including side ...  

E-Print Network (OSTI)

Aug 19, 2013 ... including side constraints regarding preventive maintenance, fixture availabil- ...... Engineering and Engineering Management, pp. 787–791.

443

Study of cesium volatility from sodium carbonate based melts  

SciTech Connect

Purpose of this study was to obtain thermodynamic data on cesium volatility from sodium carbonate-based molten salts for application to the Rockwell-ETEC molten salt oxidation process. At 1073 to 1373 K, volatility tests were conducted on a horizontal and a vertical transpiration apparatus using a carrier gas composed of CO{sub 2}(g) and H{sub 2}O(g) which was passed over or bubbled through a sodium carbonate bath containing cesium carbonate and various additives. The major vapor species was identified to be CsOH(g) except when greater than 3% chloride is present in the melt, then the major vapor species is CsCl(g). The decrease in volatility of cesium as a function of cesium concentration in Cs{sub 2}CO{sub 3{minus}}Na{sub 2}CO{sub 3} mixtures follows Raoult`s law very closely. Thus, this system exhibits close to ideal solution behavior. Addition of 22.5 wt % sodium sulfate decreases the cesium volatility by just under a factor of 2, and the addition of 10.0 wt % sodium chloride increases the cesium volatility about an order of magnitude. The addition of 2.0 wt % ash, molecular sieve, or silica show little or no effect. However, the data indicate that higher concentrations of ash will decrease the cesium volatility. For the addition of 22.5 wt % sodium sulfate the activity coefficient, {gamma}(Cs{sub 2}CO{sub 3}){sup {1/2}}, is calculated to be 0.720 {plus_minus} 0.068, and for the addition of 10.0 wt % sodium chloride, the activity coefficient, {gamma}(CsCl), is calculated to be 8.118 {plus_minus} 2.317. Assuming that Henry`s law applies, these activity coefficients are used to extrapolate the effect on cesium retention in the molten salt oxidizer of sulfate and chloride at lower cesium concentrations.

Ebbinghaus, B.B.; Krikorian, O.H.; Adamson, M.G.; Fleming, D.L.

1993-12-01T23:59:59.000Z

444

Generalized Interpolation Material Point Approach to High Melting Explosive with Cavities Under Shock  

E-Print Network (OSTI)

Criterion for contacting is critically important for the Generalized Interpolation Material Point(GIMP) method. We present an improved criterion by adding a switching function. With the method dynamical response of high melting explosive(HMX) with cavities under shock is investigated. The physical model used in the present work is an elastic-to-plastic and thermal-dynamical model with Mie-Gr\\"uneissen equation of state. We mainly concern the influence of various parameters, including the impacting velocity $v$, cavity size $R$, etc, to the dynamical and thermodynamical behaviors of the material. For the colliding of two bodies with a cavity in each, a secondary impacting is observed. Correspondingly, the separation distance $D$ of the two bodies has a maximum value $D_{\\max}$ in between the initial and second impacts. When the initial impacting velocity $v$ is not large enough, the cavity collapses in a nearly symmetric fashion, the maximum separation distance $D_{\\max}$ increases with $v$. When the initial shock wave is strong enough to collapse the cavity asymmetrically along the shock direction, the variation of $D_{\\max}$ with $v$ does not show monotonic behavior. Our numerical results show clear indication that the existence of cavities in explosive helps the creation of ``hot spots''.

X. F. Pan; Aiguo Xu; Guangcai Zhang; Jianshi Zhu

2007-10-11T23:59:59.000Z

445

Geek-Up: K East Reactor Demolition, Retrograde Melting and Cloud Pattern  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

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)

446

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.

447

Charge Melting & Polaron Collapse in LA1.2SR1.8MN207  

NLE Websites -- All DOE Office Websites (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

448

A Meteorological Experiment in the Melting Zone of the Greenland Ice Sheet  

Science Conference Proceedings (OSTI)

Preliminary results are described from a glaciometeorological experiment carried out in the margin (melting zone) of the Greenland ice sheet in the summers of 1990 and 1991. This work was initiated within the framework of a Dutch research program ...

J. Oerlemans; H. F. Vugts

1993-03-01T23:59:59.000Z

449

Radar Reflectivity-Ice Water Content Relationships for Use above the Melting Level in Hurricanes  

Science Conference Proceedings (OSTI)

Regression equations linking radar reflectivity (Ze) and ice water content (IWC) were calculated from airborne radar and particle image data that were collected above the melting level in two hurricanes. The Ze ? IWC equation from the stratiform ...

Robert A. Black

1990-09-01T23:59:59.000Z

450

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

451

Analysis of Z–R Relations Based on LDR Signatures within the Melting Layer  

Science Conference Proceedings (OSTI)

The inclusion of polarimetric measurements for the quantitative precipitation estimation (QPE) by weather radars as well as space- and airborne radars is considered most promising now-a-days. Because the melting layer region is usually marked by ...

Stefan Kowalewski; Gerhard Peters

2010-09-01T23:59:59.000Z

452

Identification of the Melting Layer through Dual-Polarization Radar Measurements at Vertical Incidence  

Science Conference Proceedings (OSTI)

Features of the melting layer of precipitation such as height and thickness are important in many meteorological applications. Doppler radar observations with a vertically pointing antenna have often been used in order to derive these features ...

Luca Baldini; Eugenio Gorgucci

2006-06-01T23:59:59.000Z

453

Local Advection of Momentum, Heat, and Moisture during the Melt of Patchy Snow Covers  

Science Conference Proceedings (OSTI)

A numerical atmospheric boundary layer model, based on higher-order turbulence closure assumptions, is developed and used to simulate the local advection of momentum, heat, and moisture during the melt of patchy snow covers over a 10-km ...

Glen E. Liston

1995-07-01T23:59:59.000Z

454

Model Representation of Freezing and Melting Precipitation: Implications for Winter Weather Forecasting  

Science Conference Proceedings (OSTI)

During episodes of sustained moderate or heavy precipitation in conjunction with near-freezing temperatures and weak horizontal temperature advection, the latent heat released (absorbed) by the freezing (melting) of falling precipitation may ...

Gary M. Lackmann; Kermit Keeter; Laurence G. Lee; Michael B. Ek

2002-10-01T23:59:59.000Z

455

Size and shape dependence on melting temperature of gallium nitride nanoparticles  

Science Conference Proceedings (OSTI)

The study of variation of the size and shape effect on the melting property of gallium nitride nanoparticles with their spherical and cylindrical geometrical feature is theoretically explored. A numerical thermodynamical model has been devoted for the ...

Paneerselvam Antoniammal; Dakshanamoorthy Arivuoli

2012-01-01T23:59:59.000Z

456

A Mathematical Model of the Ocean Boundary Layer under Drifting Melting ice  

Science Conference Proceedings (OSTI)

A mathematical model of the ocean boundary layer under drifting melting ice is formulated, verified, and applied. The model is based on the conservation equations for heat, salt, and momentum and uses turbulence models to achieve closure. Novel ...

U. Svensson; A. Omstedt

1990-02-01T23:59:59.000Z

457

Melting of Snow Cover in a Tropical Mountain Environment in Bolivia: Processes and Modeling  

Science Conference Proceedings (OSTI)

To determine the physical processes involved in the melting and disappearance of transient snow cover in nonglacierized tropical areas, the CROCUS snow model, interactions between Soil–Biosphere–Atmosphere (ISBA) land surface model, and coupled ...

Yves Lejeune; Ludovic Bouilloud; Pierre Etchevers; Patrick Wagnon; Pierre Chevallier; Jean-Emmanuel Sicart; Eric Martin; Florence Habets

2007-08-01T23:59:59.000Z

458

Increased Runoff from Melt from the Greenland Ice Sheet: A Response to Global Warming  

Science Conference Proceedings (OSTI)

The authors attribute significantly increased Greenland summer warmth and Greenland Ice Sheet melt and runoff since 1990 to global warming. Southern Greenland coastal and Northern Hemisphere summer temperatures were uncorrelated between the 1960s ...

Edward Hanna; Philippe Huybrechts; Konrad Steffen; John Cappelen; Russell Huff; Christopher Shuman; Tristram Irvine-Fynn; Stephen Wise; Michael Griffiths

2008-01-01T23:59:59.000Z

459

A preliminary study of the controls on melting during in situ vitrification. Environmental Restoration Program  

Science Conference Proceedings (OSTI)

In situ vitrification (ISV), developed by Pacific Northwest Laboratory and patented for the US Department of Energy, is one method used to stabilize contaminated soils in place. ISV involves inserting four electrodes in a square array into contaminated soil and applying an electrical potential to the electrodes. The soil is heated to above its melting point, and the molten zone expands with time to encompass the contaminated zone. After cooling, the resulting solid material is usually a mixture of glass and crystalline material that has a significantly higher resistance to leaching than did the original soils. Nonvolatile elements (most radionuclides and metals) are dissolved into the melt or encapsulated in glass if their solubility in the melt is low. Organic compounds tends to be pyrolyzed, with the decomposition products diffusing to the surface and combusting on exiting the molten zone. A hood is placed over the vitrification zone to collect off-gas particulates and volatiles into a processing trailer that scrubs contaminants from the off-gas. The current study identified key parameters and processes in the ISV melt cycle and developed an improved understanding of ISV. Analytical approximations for several properties of molten soil were determined from available data. Using a simplified geometrical approximation for melt geometry, an analytical approximation for the rate of melting (depth) vs time was derived that is consistent with data from field experiments. At small times, the depth of melting increases linearly with time. After approximately 10 h in large-scale tests, however, the depth increases as the square root of time. Existing data is also consistent with a relationship that shows the volumetric growth rate of the melt to be directly proportional to time. These conclusions suggest that heat transfer processes controlling the ISV process may be at the transition between weak convection and conduction.

Solomon, A.D.; Nyquist, J.E.; Alexiades, V.; Jacobs, G.K.; Lenhart, S.M.

1991-12-01T23:59:59.000Z

460

A preliminary study of the controls on melting during in situ vitrification  

SciTech Connect

In situ vitrification (ISV), developed by Pacific Northwest Laboratory and patented for the US Department of Energy, is one method used to stabilize contaminated soils in place. ISV involves inserting four electrodes in a square array into contaminated soil and applying an electrical potential to the electrodes. The soil is heated to above its melting point, and the molten zone expands with time to encompass the contaminated zone. After cooling, the resulting solid material is usually a mixture of glass and crystalline material that has a significantly higher resistance to leaching than did the original soils. Nonvolatile elements