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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

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

SciTech Connect (OSTI)

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

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

1993-05-26T23:59:59.000Z

2

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

SciTech Connect (OSTI)

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

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

4

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

5

Systems and methods for forming defects on graphitic materials and curing radiation-damaged graphitic materials  

DOE Patents [OSTI]

Systems and methods are disclosed herein for forming defects on graphitic materials. The methods for forming defects include applying a radiation reactive material on a graphitic material, irradiating the applied radiation reactive material to produce a reactive species, and permitting the reactive species to react with the graphitic material to form defects. Additionally, disclosed are methods for removing defects on graphitic materials.

Ryu, Sunmin; Brus, Louis E.; Steigerwald, Michael L.; Liu, Haitao

2012-09-25T23:59:59.000Z

6

#include #include  

E-Print Network [OSTI]

process #12;#include #include pid_t pid = fork(); if (pid () failed */ } else if (pid == 0) { /* parent process */ } else { /* child process */ } #12;thread #12

Campbell, Andrew T.

7

#include #include  

E-Print Network [OSTI]

#include #include //Rappels : "getpid()" permet d'obtenir son propre pid // "getppid()" renvoie le pid du père d'un processus int main (void) { pid_t pid_fils; pid_fils = fork(); if(pid_fils==-1) { printf("Erreur de création du processus fils\

Poinsot, Laurent

8

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

SciTech Connect (OSTI)

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

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

2014-04-28T23:59:59.000Z

9

NGNP Graphite Selection and Acquisition Strategy  

SciTech Connect (OSTI)

The nuclear graphite (H-451) previously used in the United States for High-Temperature Reactors (HTRs) is no longer available. New graphites have been developed and are considered suitable candidates for the Next-Generation Nuclear Plant (NGNP). A complete properties database for these new, available, candidate grades of graphite must be developed to support the design and licensing of NGNP core components. Data are required for the physical, mechanical (including radiation-induced creep), and oxidation properties of graphites. Moreover, the data must be statistically sound and take account of in-billet, between billets, and lot-to-lot variations of properties. These data are needed to support the ongoing development1 of the risk-derived American Society of Mechanical Engineers (ASME) graphite design code (a consensus code being prepared under the jurisdiction of the ASME by gas-cooled reactor and NGNP stakeholders including the vendors). The earlier Fort St. Vrain design of High-Temperature Reactor (HTRs) used deterministic performance models for H-451, while the NGNP will use new graphite grades and risk-derived (probabilistic) performance models and design codes, such as that being developed by the ASME. A radiation effects database must be developed for the currently available graphite materials, and this requires a substantial graphite irradiation program. The graphite Technology Development Plan (TDP)2 describes the data needed and the experiments planned to acquire these data in a timely fashion to support NGNP design, construction, and licensing. The strategy for the selection of appropriate grades of graphite for the NGNP is discussed here. The final selection of graphite grades depends upon the chosen reactor type and vendor because the reactor type (pebble bed or prismatic block) has a major influence on the graphite chosen by the designer. However, the time required to obtain the needed irradiation data for the selected NGNP graphite is sufficiently long that a preliminary selection was necessary in 2005. A further downselect was made in 2006, reducing the number of candidate graphites to two, with two reserve grades. Since then additional information has been obtained from potential NGNP vendors and graphite manufacturers. Therefore, the NGNP graphite selection strategy has been reassessed. New recommendations, and the rationale for these recommendations, are reported and discussed here.

Burchell, T.; Bratton, R.; Windes, W.

2007-09-30T23:59:59.000Z

10

Melt containment member  

DOE Patents [OSTI]

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

Rieken, Joel R.; Heidloff, Andrew J.

2014-09-09T23:59:59.000Z

11

Modeling Fission Product Sorption in Graphite Structures  

SciTech Connect (OSTI)

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

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

2013-04-08T23:59:59.000Z

12

Oxidation Resistant Graphite Studies  

SciTech Connect (OSTI)

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

W. Windes; R. Smith

2014-07-01T23:59:59.000Z

13

Melting of iron-aluminide alloys  

SciTech Connect (OSTI)

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

Sikka, V.K.

1990-01-01T23:59:59.000Z

14

Graphite Technology Development Plan  

SciTech Connect (OSTI)

This technology development plan is designed to provide a clear understanding of the research and development direction necessary for the qualification of nuclear grade graphite for use within the Next Generation Nuclear Plant (NGNP) reactor. The NGNP will be a helium gas cooled Very High Temperature Reactor (VHTR) with a large graphite core. Graphite physically contains the fuel and comprises the majority of the core volume. Considerable effort will be required to ensure that the graphite performance is not compromised during operation. Based upon the perceived requirements the major data needs are outlined and justified from the perspective of reactor design, reatcor performance, or the reactor safety case. The path forward for technology development can then be easily determined for each data need. How the data will be obtained and the inter-relationships between the experimental and modeling activities will define the technology development for graphite R&D. Finally, the variables affecting this R&D program are discussed from a general perspective. Factors that can significantly affect the R&D program such as funding, schedules, available resources, multiple reactor designs, and graphite acquisition are analyzed.

W. Windes; T. Burchell; R. Bratton

2007-09-01T23:59:59.000Z

15

Forming gas treatment of lithium ion battery anode graphite powders  

DOE Patents [OSTI]

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

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

2014-09-16T23:59:59.000Z

16

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

17

Graphite Gamma Scan Results  

SciTech Connect (OSTI)

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

Mark W. Drigert

2014-04-01T23:59:59.000Z

18

Irradiation Creep in Graphite  

SciTech Connect (OSTI)

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

Ubic, Rick; Butt, Darryl; Windes, William

2014-03-13T23:59:59.000Z

19

Improved graphite furnace atomizer  

DOE Patents [OSTI]

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

Siemer, D.D.

1983-05-18T23:59:59.000Z

20

Diamond-graphite field emitters  

DOE Patents [OSTI]

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

Valone, Steven M. (Santa Fe, NM)

1997-01-01T23:59:59.000Z

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


21

Electroless plating of graphite with copper and nickel  

SciTech Connect (OSTI)

Decommissioning in the European Union of gas-cooled nuclear reactors using graphite as the moderator will generate a large amount of irradiated graphite as waste. Graphite is a radioactive waste of relatively low activity and consequently the options considered for the management of the waste may include: (i) incineration, (ii) ocean bed disposal, (iii) deep geological disposal, and (iv) shallow land burial. In case the last is the selected mode, an appropriate conditioning procedure is necessary before final disposal, by covering the graphite with a material avoiding or reducing the emission of radionuclides to its surrounding. This work analyses the possibility of conditioning graphite pieces (with a large proportion of pores of different sizes up to 100 {micro}m) with a metal coating of copper or nickel produced by electroless plating, with the aim of completely isolating the graphite from its surrounding. Electroless plating with copper results in a very large proportion of pores filled or covered, but a fraction of the pores remain in the graphite, which decreases with increasing thickness of metal deposit. Furthermore, the copper plating is permeable to liquids and consequently the graphite does not become completely isolated from the surrounding. The percentage of porosity filled or covered by nickel deposits is similar to copper, but they are not permeable to liquids, at least when the thickness is relatively high, and consequently the access of the liquids to the graphite is rather limited. However, when electroless plating with copper is followed by nickel deposition the graphite becomes isolated from the exterior.

Caturla, F.; Molina, F.; Molina-Sabio, M.; Rodriguez-Reinoso, F. [Univ. de Alicante (Spain). Dept. de Quimica Inorganica; Esteban, A. [CIEMAT, Madrid (Spain)

1995-12-01T23:59:59.000Z

22

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

23

Noncovalently functionalized graphitic mesoporous carbon as a...  

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

functionalized graphitic mesoporous carbon as a stable support of Pt nanoparticles for oxygen reduction. Noncovalently functionalized graphitic mesoporous carbon as a stable...

24

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

E-Print Network [OSTI]

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

25

Vacuum Induction Melting Unit Induction heating is a process wherein induced eddy currents heat conductive materials. This heating  

E-Print Network [OSTI]

graphite) crucible inside the coil. The coil serves as the transformer primary and the part to be heated Principle: An outline of the induction melting system is presented here. A solid state RF power supply sends can be melted at a time. There are three main parts to the system: chiller, power unit and vacuum unit

Subramaniam, Anandh

26

Brookhaven Graphite Research Reactor Workshop  

Broader source: Energy.gov [DOE]

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...

27

Macroscopic Properties of Restacked, Redox-Liquid Exfoliated Graphite and Graphite Mimics Produced in Bulk Quantities  

SciTech Connect (OSTI)

The excellent properties exhibited by monolayer graphene have spurred the development of exfoliation techniques using bulk graphite to produce large quantities of pristine monolayer sheets. Development of simple chemistry to exfoliate and intercalate graphite and graphite mimics in large quantities is required for numerous applications. To determine the macroscopic behavior of restacked, exfoliated bulk materials, a systematic approach is presented using a simple, redox-liquid sonication process along to obtain large quantities of 2D and 3D hexagonally layered graphite, molybdenum disulfi de, and boron nitride, which are subsequently characterized to observe chemical and structural changes. For MoS 2 sonicated with the antioxidant sodium bisulfi te, results from Raman spectroscopy, X-ray diffraction, and electron microscopy indicate the presence of distorted phases from different polymorphs, and apparent nanotube structures in the bulk, restacked powder. Furthermore, using thermograviemtric analysis, the antioxidant enhances the resistance to oxidative degradation of MoS 2 , upon thermal treatment up to 900 C. The addition of the ionic antioxidant decreased dispersion stability in non-polar solvent, suggesting decreased compatibility with non-polar systems. Using simple chemical methods, the ability to generate tailored multidimensional layered materials with unique macroscopic properties is critical for numerous applications, including electrical devices, reinforced polymer composites, lithium ion capacitors, and chemical sensing.

Srivastava, Vikram K [ORNL; Quinlan, Ronald [ORNL; Agapov, Alexander L [ORNL; Dunlap, John R [ORNL; Nelson, Kimberly M [ORNL; Duranty, Edward R [ORNL; Sokolov, Alexei P [ORNL; Bhat, Gajanan [ORNL; Mays, Jimmy [ORNL

2014-01-01T23:59:59.000Z

28

Graphite electrode DC arc furnace. Innovative technology summary report  

SciTech Connect (OSTI)

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

NONE

1999-05-01T23:59:59.000Z

29

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

SciTech Connect (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

30

NGNP Graphite Testing and Qualification Specimen Selection Strategy  

SciTech Connect (OSTI)

The available grades of graphite for the NGNP are reviewed. A selection matrix is presented outlining the available grades for the NGNP graphite irradiation program based upon input from potential NGNP vendors, graphite manufactures, and graphite experts.

Robert Bratton

2005-05-01T23:59:59.000Z

31

Micro Joining of Aluminum Graphite Composites  

E-Print Network [OSTI]

Advanced aluminum graphite composites have unique thermal properties due to opposing coefficients of thermal expansion of aluminum and graphite. The thermal and mechanical properties of such composites are anisotropic due to directional properties...

Velamati, Manasa

2012-07-16T23:59:59.000Z

32

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

33

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

34

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

35

AGC-3 Graphite Preirradiation Data Analysis Report  

SciTech Connect (OSTI)

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

36

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

SciTech Connect (OSTI)

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

Zhamu, Aruna; Jang, Bor Z.

2014-06-17T23:59:59.000Z

37

Uranium Oxide Aerosol Transport in Porous Graphite  

SciTech Connect (OSTI)

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

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

2012-01-23T23:59:59.000Z

38

Stable aqueous dispersions of graphitic nanoplatelets via the reduction of exfoliated graphite oxide in the presence of poly(sodium  

E-Print Network [OSTI]

Stable aqueous dispersions of graphitic nanoplatelets via the reduction of exfoliated graphite be prepared via an exfoliation/in-situ reduction of graphite oxide in the presence of poly(sodium 4 prepare graphite nanoplatelets via the chemical reduction of exfoliated graphite oxide nanoplatelets

39

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

40

Graphite Reactor | ornl.gov  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-SeriesFlickr Flickr Editor'sshortGeothermalGo BackGrantsGraphics ServicesGraphite

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

Establish and Expand Commercial Production of Graphite Anode...  

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

and Expand Commercial Production of Graphite Anode Materials for High Performance Lithium-ion Batteries Establish and Expand Commercial Production of Graphite Anode Materials...

42

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

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

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

43

Polyelectrolyte-Induced Reduction of Exfoliated Graphite Oxide...  

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

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

44

Microsoft Word - tev-235 Technical Evaluation of Graphite Acquisition...  

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

graphite manufacturing companies have an approved NQA-1-based quality assurance (QA) program. Two graphite vendors supplying three of the major grades being tested in the...

45

Inhibition of Oxidation in Nuclear Graphite  

SciTech Connect (OSTI)

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

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

2013-10-01T23:59:59.000Z

46

Quantum modelling of hydrogen chemisorption on graphene and graphite  

SciTech Connect (OSTI)

The chemisorption of hydrogen on graphene or graphite is studied within a quantum formalism involving a subsystem coupled to a phonon bath. The subsystem includes the hydrogen atom approaching the surface perpendicularly right on top of a carbon atom which puckers out of the surface. The bath includes the acoustic and optical phonon modes vibrating perpendicularly to the surface. Couplings between subsystem and bath are obtained with a periodic density functional theory calculation. Trapping probabilities are obtained as a function of the hydrogen atom kinetic energy. These results are discussed in the light of the experimental hydrogenation studies performed on graphite by Zecho et al. [J. Chem. Phys. 117, 8486 (2002)] and on graphene by Haberer et al. [Adv. Mater. 23, 4497 (2011)].

Karlický, František, E-mail: frantisek.karlicky@upol.cz [Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University, T?. 17. listopadu 12, 771 46 Olomouc (Czech Republic)] [Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University, T?. 17. listopadu 12, 771 46 Olomouc (Czech Republic); Lepetit, Bruno, E-mail: bruno.lepetit@irsamc.ups-tlse.fr; Lemoine, Didier, E-mail: didier.lemoine@irsamc.ups-tlse.fr [Laboratoire Collisions Agrégats Réactivité, IRSAMC and UMR5589 du CNRS, Université de Toulouse, UPS, 118 route de Narbonne, 31062 Toulouse cedex (France)] [Laboratoire Collisions Agrégats Réactivité, IRSAMC and UMR5589 du CNRS, Université de Toulouse, UPS, 118 route de Narbonne, 31062 Toulouse cedex (France)

2014-03-28T23:59:59.000Z

47

Thermal and electrical conduction in the compaction direction of exfoliated graphite  

E-Print Network [OSTI]

Thermal and electrical conduction in the compaction direction of exfoliated graphite in the compaction direction of graphite-flake-based exfoliated graphite have been decoupled. The compact Exfoliated graphite is elongated graphite particles obtained by the exfoliation (typically involving rapid

Chung, Deborah D.L.

48

AGC-2 Graphite Preirradiation Data Analysis Report  

SciTech Connect (OSTI)

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

49

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

50

Glacier melt contribution to streamflow1 Neil Schaner1  

E-Print Network [OSTI]

, firn, or ice. We50 include all ice caps (ice sheets covering less than 50,000 km2 ) and other permanent1 Glacier melt contribution to streamflow1 Neil Schaner1 , Nathalie Voisin2 , Bart Nijssen1 gross domestic product,28 resides in areas that rely on snow or glacier melt for a majority of its water

Washington at Seattle, University of

51

Seasonal glacier melt contribution to streamflow Neil Schaner  

E-Print Network [OSTI]

source is perennial snow, firn, or ice. We include all ice caps (ice sheets covering less than 50,000 km21 Seasonal glacier melt contribution to streamflow Neil Schaner Department of Civil is the population at risk to future glacier changes. We estimate an upper bound on glacier melt contribution

Washington at Seattle, University of

52

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

53

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

54

Superhydrophilic graphite surfaces and water-dispersible graphite colloids by electrochemical exfoliation  

SciTech Connect (OSTI)

Superhydrophilic graphite surfaces and water-dispersible graphite colloids are obtained by electrochemical exfoliation with hydrophobic graphite electrodes. Such counterintuitive characteristics are caused by partial oxidation and investigated by examining both graphite electrodes and exfoliated particles after electrolysis. The extent of surface oxidation can be explored through contact angle measurement, scanning electron microscope, electrical sheet resistance, x-ray photoelectron spectroscopy, zeta-potential analyzer, thermogravimetric analysis, UV-visible, and Raman spectroscopy. The degree of wettability of the graphite anode can be altered by the electrolytic current and time. The water contact angle declines generally with increasing the electrolytic current or time. After a sufficient time, the graphite anode becomes superhydrophilic and its hydrophobicity can be recovered by peeling with adhesive tape. This consequence reveals that the anodic graphite is oxidized by oxygen bubbles but the oxidation just occurs at the outer layers of the graphite sheet. Moreover, the characteristics of oxidation revealed by UV peak shift, peak ratio between D and G bands, and negative zeta-potential indicate the presence of graphite oxide on the outer shell of the exfoliated colloids. However, thermogravimetric analysis for the extent of decomposition of oxygen functional groups verifies that the amount of oxygen groups is significantly less than that of graphite oxide prepared via Hummer method. The structure of this partially oxidized graphite may consist of a graphite core covered with an oxidized shell. The properties of the exfoliated colloids are also influenced by pH of the electrolytic solution. As pH is increased, the extent of oxidation descends and the thickness of oxidized shell decreases. Those results reveal that the degree of oxidation of exfoliated nanoparticles can be manipulated simply by controlling pH.

Li, Yueh-Feng [Department of Chemical and Materials Engineering, National Central University, Jhongli, 320 Taiwan (China)] [Department of Chemical and Materials Engineering, National Central University, Jhongli, 320 Taiwan (China); Chen, Shih-Ming; Lai, Wei-Hao [Materials and Chemical Research Laboratories, Industrial Technology Research Institute, Chutung, Hsinchu, 31040 Taiwan (China)] [Materials and Chemical Research Laboratories, Industrial Technology Research Institute, Chutung, Hsinchu, 31040 Taiwan (China); Sheng, Yu-Jane [Department of Chemical Engineering, National Taiwan University, Taipei, 106 Taiwan (China)] [Department of Chemical Engineering, National Taiwan University, Taipei, 106 Taiwan (China); Tsao, Heng-Kwong [Department of Chemical and Materials Engineering, Department of Physics, National Central University, Jhongli, 320 Taiwan (China)] [Department of Chemical and Materials Engineering, Department of Physics, National Central University, Jhongli, 320 Taiwan (China)

2013-08-14T23:59:59.000Z

55

Laboratory for Characterization of Irradiated Graphite  

SciTech Connect (OSTI)

The newly completed Idaho National Laboratory (INL) Carbon Characterization Laboratory (CCL) is located in Labs C19 and C20 of the Idaho National Laboratory Research Center (IRC). The CCL was established under the Next Generation Nuclear Plant (NGNP) Project to support graphite and ceramic composite research and development activities. The research is in support of the Advanced Graphite Creep (AGC) experiment — a major material irradiation experiment within the NGNP Graphite program. The CCL is designed to characterize and test low activated irradiated materials such as high purity graphite, carbon-carbon composites, and silicon-carbide composite materials. The laboratory is fully capable of characterizing material properties for both irradiated and nonirradiated materials.

Karen A. Moore

2010-03-01T23:59:59.000Z

56

Pyrolytic graphite production : automation of material placement  

E-Print Network [OSTI]

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

Olle, Chase R

2014-01-01T23:59:59.000Z

57

Immobilization of Rocky Flats Graphite Fines Residue  

SciTech Connect (OSTI)

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

Rudisill, T.S.

1999-04-06T23:59:59.000Z

58

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

SciTech Connect (OSTI)

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

Mark C. Carroll; David T. Rohrbaugh

2013-08-01T23:59:59.000Z

59

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

60

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

SciTech Connect (OSTI)

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

Peeler, D.K.

2001-07-24T23:59:59.000Z

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

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

SciTech Connect (OSTI)

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

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

2014-06-10T23:59:59.000Z

62

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

63

Electron beam melting of charge based on titanium sponge  

SciTech Connect (OSTI)

An experience of 0.8 MW consumable box melting furnace operation and theoretical simulation have led to the further development of the FIKO plant under construction on the base of melting of two consumable box-like bullets which move opposite each other and form narrow heated space between melted butt ends. It allows to reduce vaporization, spatter and radiation losses by several times and to reach two times increase in melting rate and 99%(97%) yield for c.p. titanium (alloys) without furnace power add. Future furnace design will provide the optimum protection of vacuum pumps against chlorides, the safety when melting titanium sponge and will permit hot ingots to move to the special furnace for EB surface conditioning. The maximum productivity is to be 18,000 t/year. The furnace can be used for the manufacture of aluminum-, copper-, iron-, nickel-, tungsten-based alloys and others of any charge including salvage.

Tikhonovsky, A.L.; Tikhonovsky, K.A. [JS Co FIKO, Kiev (Ukraine)

1995-12-31T23:59:59.000Z

64

Method for producing thin graphite flakes with large aspect ratios  

DOE Patents [OSTI]

A method for making graphite flakes of high aspect ratio by the steps of providing a strong concentrated acid and heating the graphite in the presence of the acid for a time and at a temperature effective to intercalate the acid in the graphite; heating the intercalated graphite at a rate and to a temperature effective to exfoliate the graphite in discrete layers; subjecting the graphite layers to ultrasonic energy, mechanical shear forces, or freezing in an amount effective to separate the layes into discrete flakes.

Bunnell, L. Roy (Kennewick, WA)

1993-01-01T23:59:59.000Z

65

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

66

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

67

Behavior of melts during softening and melting down of iron ore sinter under load  

SciTech Connect (OSTI)

In order to achieve effective operation in the blast furnace, the distribution control and quality improvement of burden materials are very important. In spite of the difficulties in obtaining suitable samples and making direct observation, significant progress including the placement of probes into the stack, tuyere drilling and laboratory simulation studies has been made. Investigation of the behavior of melts during softening and melting down was carried out in the temperature range of 800 C to 1,515 C. In this report, emphasis is given to investigating the mineral formation and properties of melts during softening and melting down of the iron ore sinter. Sized coke layers were placed above and below the sample to maintain uniform upward flow of gas and insure a smooth downward flow of melts. When the temperature of the sample reached the set point during the test the power was shut off and the sample was cooled in the furnace air. The weight, the height, porosity and contraction of each sample were measured. Chemical composition, observation of microstructures, SEM analysis and X-ray diffraction analysis were conducted. Results are presented.

Cho, Y.H. [Research Inst. of Industrial Science and Technology, Pohang (Korea, Republic of)

1995-12-01T23:59:59.000Z

68

Ferritic steel melt and FLiBe/steel experiment : melting ferritic steel.  

SciTech Connect (OSTI)

In preparation for developing a Z-pinch IFE power plant, the interaction of ferritic steel with the coolant, FLiBe, must be explored. Sandia National Laboratories Fusion Technology Department was asked to drop molten ferritic steel and FLiBe in a vacuum system and determine the gas byproducts and ability to recycle the steel. We tried various methods of resistive heating of ferritic steel using available power supplies and easily obtained heaters. Although we could melt the steel, we could not cause a drop to fall. This report describes the various experiments that were performed and includes some suggestions and materials needed to be successful. Although the steel was easily melted, it was not possible to drip the molten steel into a FLiBe pool Levitation melting of the drop is likely to be more successful.

Troncosa, Kenneth P.; Smith, Brandon M.; Tanaka, Tina Joan

2004-11-01T23:59:59.000Z

69

Low-melting point heat transfer fluid  

DOE Patents [OSTI]

A low-melting point, heat transfer fluid made of a mixture of five inorganic salts including about 29.1-33.5 mol % LiNO.sub.3, 0-3.9 mol % NaNO.sub.3, 2.4-8.2 mol % KNO.sub.3, 18.6-19.9 mol % NaNO.sub.2, and 40-45.6 mol % KNO.sub.2. These compositions can have liquidus temperatures below 80.degree. C. for some compositions.

Cordaro, Joseph Gabriel (Oakland, CA); Bradshaw, Robert W. (Livermore, CA)

2010-11-09T23:59:59.000Z

70

Nuclear Graphite -Fission Reactor Brief Outline of Experience and  

E-Print Network [OSTI]

-cooled ­ Chicago Pile, GLEEP, BEPO, Windscale Piles, G1-France · Light Water-cooled Graphite Moderated ­ Hanford

McDonald, Kirk

71

COMBUSTIBILITY OF HIGH-PURITY, NUCLEAR-GRADE GRAPHITE  

E-Print Network [OSTI]

graphite-moderated nuclear reactors, primarily bex~use of the accidents at Windscale in 1957 [1] and

M. B. Richards

72

Characteristics of Graphitic Films for Carbon Based Magnetism and Electronics  

E-Print Network [OSTI]

the nineteenth century to exfoliate graphene, is now used tolayers of graphite to exfoliate the graphene sheets. This

Hong, Jeongmin

2009-01-01T23:59:59.000Z

73

Engineering of Ferrite-Graphite Composite Media for Microwave Shields  

E-Print Network [OSTI]

Engineering of Ferrite-Graphite Composite Media for Microwave Shields Marina Koledintseva, PoornaAA@mpei.ru Abstract-- An electromagnetic shielding of objects using ferrite-graphite composites is considered- shielding; dielectric base material; ferrite- graphite composite, Maxwell Garnett formulation I

Koledintseva, Marina Y.

74

CHARACTERIZATION, TREATMENT AND CONDITIONING OF RADIOACTIVE GRAPHITE FROM  

E-Print Network [OSTI]

Graphite has been used as a moderator and reflector of neutrons in more than 100 nuclear power plants and in many research and plutonium-production reactors. It is used primarily as a neutron reflector or neutron moderator, although graphite is also used for other features of reactor cores, such as fuel sleeves. Many of the graphite-moderated reactors are now quite old, with some already shutdown. Therefore radioactive graphite dismantling and the management of radioactive graphite waste are becoming an increasingly important issue for a number of IAEA Member States. Worldwide, there are more than 230 000 tonnes of radioactive graphite which will eventually need to be managed as radioactive waste. Proper management of radioactive graphite waste requires complex planning and the implementation of several interrelated operations. There are two basic options for graphite waste management: (1) packaging of non-conditioned graphite waste with subsequent direct disposal of the waste packages, and (2) conditioning of graphite waste (principally either by incineration or calcination) with separate disposal of any waste products produced, such as incinerator ash. In both cases, the specific properties of graphite — such as Wigner energy, graphite dust explosibility, and

Graphite From Decommissioning; Graphite From Decommissioning

75

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

76

Nanometal-Decorated Exfoliated Graphite Nanoplatelet Based Glucose  

E-Print Network [OSTI]

Nanometal-Decorated Exfoliated Graphite Nanoplatelet Based Glucose Biosensors with High Sensitivity demonstrated for the first time that exfoli- ated graphite nanoplatelets (xGnPs), which are 1 10 nm, and affordable amperometric glucose biosensor using exfoliated graphite nanoplatelets (xGnPs) decorated with Pt

Lee, Ilsoon

77

US graphite reactor D&D experience  

SciTech Connect (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

78

Environmental Management Brookhaven Graphite Research Reactor  

E-Print Network [OSTI]

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

Homes, Christopher C.

79

Plasma arc melting of zirconium  

SciTech Connect (OSTI)

Zirconium, like some other refractory metals, has an undesirable sensitivity to interstitials such as oxygen. Traditionally, zirconium is processed by electron beam melting to maintain minimum interstitial contamination. Electron beam melted zirconium, however, does not respond positively to mechanical processing due to its large grain size. The authors undertook a study to determine if plasma arc melting (PAM) technology could be utilized to maintain low interstitial concentrations and improve the response of zirconium to subsequent mechanical processing. The PAM process enabled them to control and maintain low interstitial levels of oxygen and carbon, produce a more favorable grain structure, and with supplementary off-gassing, improve the response to mechanical forming.

Tubesing, P.K.; Korzekwa, D.R.; Dunn, P.S.

1997-12-31T23:59:59.000Z

80

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

SciTech Connect (OSTI)

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

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

2014-01-01T23:59:59.000Z

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

Development of a graphite probe calorimeter for absolute clinical dosimetry  

SciTech Connect (OSTI)

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

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

2013-02-15T23:59:59.000Z

82

Thermally efficient melting for glass making  

DOE Patents [OSTI]

The present invention is an integrated process for the production of glass utilizing combustion heat to melt glassmaking materials in a glassmaking furnace. The fuel combusted to produce heat sufficient to melt the glassmaking materials is combusted with oxygen-enriched oxidant to reduce heat losses from the offgas of the glassmaking furnace. The process further reduces heat losses by quenching hot offgas from the glassmaking furnace with a process stream to retain the heat recovered from quench in the glassmaking process with subsequent additional heat recovery by heat exchange of the fuel to the glassmaking furnace, as well as the glassmaking materials, such as batch and cullet. The process includes recovery of a commercially pure carbon dioxide product by separatory means from the cooled, residual offgas from the glassmaking furnace.

Chen, Michael S. K. (Zionsville, PA); Painter, Corning F. (Allentown, PA); Pastore, Steven P. (Allentown, PA); Roth, Gary (Trexlertown, PA); Winchester, David C. (Allentown, PA)

1991-01-01T23:59:59.000Z

83

Graphite Oxidation Simulation in HTR Accident Conditions  

SciTech Connect (OSTI)

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

Mohamed El-Genk

2012-10-19T23:59:59.000Z

84

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

E-Print Network [OSTI]

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

Geohegan, David B.

85

Scaleable Clean Aluminum Melting Systems  

SciTech Connect (OSTI)

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

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

2008-02-15T23:59:59.000Z

86

Conversion of lignin precursors to carbon fibers with nanoscale graphitic domains  

SciTech Connect (OSTI)

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

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

2014-01-01T23:59:59.000Z

87

Status of the NGNP graphite creep experiments AGC-1 and AGC-2 irradiated in the advanced test reactor  

SciTech Connect (OSTI)

The United States Department of Energy's Next Generation Nuclear Plant (NGNP) Program will be irradiating six nuclear graphite creep experiments in the Advanced Test Reactor (ATR) located at the Idaho National Laboratory (INL). The graphite experiments will be irradiated over the next six to eight years to support development of a graphite irradiation performance data base on the new nuclear grade graphites now available for use in high temperature gas reactors. The goals of the irradiation experiments are to obtain irradiation performance data, including irradiation creep, at different temperatures and loading conditions to support design of the next generation nuclear plant (NGNP) very high temperature gas reactor, as well as other future gas reactors. The experiments will each consist of a single capsule that will contain six peripheral stacks of graphite specimens, with half of the graphite specimens in each stack under a compressive load, while the other half of the specimens will not be subjected to a compressive load during irradiation. The six peripheral stacks will have three different compressive loads applied to the top half of three diametrically opposite pairs 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.

S. Blaine Grover

2014-05-01T23:59:59.000Z

88

Atomic resolution images of graphite in air  

SciTech Connect (OSTI)

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

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

1988-12-01T23:59:59.000Z

89

Nondestructive Evaluation of Nuclear-Grade Graphite  

SciTech Connect (OSTI)

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

Dennis C. Kunerth; Timothy R. McJunkin

2011-07-01T23:59:59.000Z

90

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

SciTech Connect (OSTI)

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

91

Flexible graphite modified by carbon black paste for use as a thermal interface material  

E-Print Network [OSTI]

graphite is a material that is made by the com- pression of exfoliated graphite, which is in turn made by the exfoliation of intercalated graphite flake [3]. Due to the accordion-like microstructure of exfoliated graphite, mechan- ical interlocking between pieces of exfoliated graphite (each piece obtained from a flake

Chung, Deborah D.L.

92

Raman spectroscopic studies of chemical speciation in calcium chloride melts  

SciTech Connect (OSTI)

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

Windisch, Charles F.; Lavender, Curt A.

2005-02-01T23:59:59.000Z

93

Putting the Spin on Graphite: Observing the Spins of Impurity...  

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

the Spins of Impurity Atoms Align Friday, February 28, 2014 The existence of magnetism in graphite is a very intriguing subject. The possibility to exploit the magnetic...

94

Role of Nuclear Grade Graphite in Oxidation in Modular HTGRs  

SciTech Connect (OSTI)

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

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

2014-11-01T23:59:59.000Z

95

Direct printing and reduction of graphite oxide for flexible supercapacitors  

SciTech Connect (OSTI)

We report direct printing and photo-thermal reduction of graphite oxide (GO) to obtain a highly porous pattern of interdigitated electrodes, leading to a supercapacitor on a flexible substrate. Key parameters optimized include the amount of GO delivered, the suitable photo-thermal energy level for effective flash reduction, and the substrate properties for appropriate adhesion after reduction. Tests with supercapacitors based on the printed-reduced GO showed performance comparable with commercial supercapacitors: the energy densities were 1.06 and 0.87 mWh/cm{sup 3} in ionic and organic electrolytes, respectively. The versatility in the architecture and choice of substrate makes this material promising for smart power applications.

Jung, Hanyung [Department of Nano Science and Technology, Graduate School of Convergence Science and Technology, Seoul National University, Seoul (Korea, Republic of); Ve Cheah, Chang [Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul (Korea, Republic of); Jeong, Namjo [Energy Materials and Convergence Research Department, Korea Institute of Energy Research, Daejeon (Korea, Republic of); Lee, Junghoon, E-mail: jleenano@snu.ac.kr [Department of Nano Science and Technology, Graduate School of Convergence Science and Technology, Seoul National University, Seoul (Korea, Republic of); Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul (Korea, Republic of); Division of WCU Multiscale Mechanical Design, School of Mechanical and Aerospace Engineering, Seoul National University, Seoul (Korea, Republic of)

2014-08-04T23:59:59.000Z

96

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

SciTech Connect (OSTI)

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

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

2014-01-01T23:59:59.000Z

97

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

SciTech Connect (OSTI)

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

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

1992-05-01T23:59:59.000Z

98

Vapor deposition of water on graphitic surfaces: Formation of amorphous ice, bilayer ice, ice I, and liquid water  

SciTech Connect (OSTI)

Carbonaceous surfaces are a major source of atmospheric particles and could play an important role in the formation of ice. Here we investigate through molecular simulations the stability, metastability, and molecular pathways of deposition of amorphous ice, bilayer ice, and ice I from water vapor on graphitic and atomless Lennard-Jones surfaces as a function of temperature. We find that bilayer ice is the most stable ice polymorph for small cluster sizes, nevertheless it can grow metastable well above its region of thermodynamic stability. In agreement with experiments, the simulations predict that on increasing temperature the outcome of water deposition is amorphous ice, bilayer ice, ice I, and liquid water. The deposition nucleation of bilayer ice and ice I is preceded by the formation of small liquid clusters, which have two wetting states: bilayer pancake-like (wetting) at small cluster size and droplet-like (non-wetting) at larger cluster size. The wetting state of liquid clusters determines which ice polymorph is nucleated: bilayer ice nucleates from wetting bilayer liquid clusters and ice I from non-wetting liquid clusters. The maximum temperature for nucleation of bilayer ice on flat surfaces, T{sub B}{sup max} is given by the maximum temperature for which liquid water clusters reach the equilibrium melting line of bilayer ice as wetting bilayer clusters. Increasing water-surface attraction stabilizes the pancake-like wetting state of liquid clusters leading to larger T{sub B}{sup max} for the flat non-hydrogen bonding surfaces of this study. The findings of this study should be of relevance for the understanding of ice formation by deposition mode on carbonaceous atmospheric particles, including soot.

Lupi, Laura; Kastelowitz, Noah; Molinero, Valeria, E-mail: Valeria.Molinero@utah.edu [Department of Chemistry, The University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112-0850 (United States)

2014-11-14T23:59:59.000Z

99

Dry melting of high albite  

SciTech Connect (OSTI)

The properties of albitic melts are central to thermodynamic models for synthetic and natural granitic liquids. The authors have analyzed published phase-equilibrium and thermodynamic data for the dry fusion of high albite to develop a more accurate equation for the Biggs free energy of this reaction to 30 kbar and 1,400 C. Strict criteria for reaction reversal were sued to evaluate the phase-equilibrium data, and the thermodynamic properties of solid and liquid albite were evaluated using the published uncertainties in the original measurements. Results suggest that neither available phase-equilibrium experiments nor thermodynamic data tightly constrain the location of the reaction. Experimental solidus temperatures at 1 atm range from 1,100 to 1,120 C. High-pressure experiments were not reversed completely and may have been affected by several sources of error, but the apparent inconsistencies among the results of the various experimentalists are eliminated when only half-reversal data are considered. Uncertainties in thermodynamic data yield large variations in permissible reaction slopes. Disparities between experimental and calculated melting curves are, therefore, largely attributable to these difficulties, and there is no fundamental disagreement between the available phase-equilibrium and thermodynamic data for the dry melting of albite. Consequently, complex speciation models for albitic melts, based on the assumption that these discrepancies represent a real characteristic of the system, are unjustified at this time.

Anovitz, L.M.: Blencoe, J.G.

1999-12-01T23:59:59.000Z

100

Stability and breakdown of Ca{sup 13}CO{sub 3} melt associated with formation of {sup 13}C-diamond in static high pressure experiments up to 43 GPa and 3900 K  

SciTech Connect (OSTI)

Melting of calcium carbonate Ca{sup 13}CO{sub 3}, stability of the melt and its decomposition were studied in static high pressure experiments at pressures of 11-43 GPa and temperatures of 1600-3900 K using diamond anvil cell technique with laser heating. We observed formation of {sup 13}C-graphite (below 16 GPa) and {sup 13}C-diamond (between 16 and 43 GPa) on decomposition of the Ca{sup 13}CO{sub 3} melt at temperatures above 3400 K. At temperatures below 3400 K congruent melting of calcium carbonate was confirmed. The experimental results were applied to construction of the phase diagram of CaCO{sub 3} up to 43 GPa and 3900 K focusing at the melting curve of calcium carbonate and the decomposition phase boundary of CaCO{sub 3} melt. - Graphical abstract: Highlights: Black-Right-Pointing-Pointer Phase states of CaCO{sub 3} were studied at P=11-43 GPa and T=1600-3900 K. Black-Right-Pointing-Pointer {sup 13}C-diamond easily crystallizes in carbonate-carbon (Ca{sup 13}CO{sub 3-}{sup 13}C-graphite) melt-solutions. Black-Right-Pointing-Pointer Ca-carbonate melts congruently that was observed in experiments in DAC with laser heating. Black-Right-Pointing-Pointer Decomposition of CaCO{sub 3} melt, indicated by formation of graphite and/or diamond. Black-Right-Pointing-Pointer Decomposition of CaCO{sub 3} was observed at temperatures above 3400 K in the pressure interval studied.

Spivak, A.V., E-mail: spivak@iem.ac.ru [Institute of Experimental Mineralogy of the Russian Academy of Sciences, Chernogolovka, Moscow Region (Russian Federation); Litvin, Yu.A. [Institute of Experimental Mineralogy of the Russian Academy of Sciences, Chernogolovka, Moscow Region (Russian Federation); Ovsyannikov, S.V. [Bayerishes Geoinstitut, University of Bayreuth, Bayreuth (Germany); Dubrovinskaia, N.A. [Material Physics and Technology at Extreme Conditions, Laboratory of Crystallography, University of Bayreuth, Bayreuth (Germany); Dubrovinsky, L.S. [Bayerishes Geoinstitut, University of Bayreuth, Bayreuth (Germany)

2012-07-15T23:59:59.000Z

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


101

Letter to the Editor Microwave assisted exfoliation and reduction of graphite  

E-Print Network [OSTI]

Letter to the Editor Microwave assisted exfoliation and reduction of graphite oxide yet versatile method to simultaneously achieve the exfoliation and reduction of graphite oxide of crumpled, few-layer thick and electronically conductive graphitic sheets. Using the microwave exfoliated

102

Using Graphite to view network data  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLasDelivered energy consumption by sectorlongUpdates byUser Guide PrintUsers'DominionGraphite to

103

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

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

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

104

Exfoliation of Graphite Oxide in Propylene Carbonate and Thermal  

E-Print Network [OSTI]

Exfoliation of Graphite Oxide in Propylene Carbonate and Thermal Reduction of the Resulting,2 The exfoliation of graphite oxide (GO) followed by reduction has provided an affordable route to the large scale (by the exfoliation of GO) has been demon- strated by the fabrication of paperlike films,3 transparent

105

Multiscale modeling of polyisoprene on graphite  

SciTech Connect (OSTI)

The local dynamics and the conformational properties of polyisoprene next to a smooth graphite surface constructed by graphene layers are studied by a multiscale methodology. First, fully atomistic molecular dynamics simulations of oligomers next to the surface are performed. Subsequently, Monte Carlo simulations of a systematically derived coarse-grained model generate numerous uncorrelated structures for polymer systems. A new reverse backmapping strategy is presented that reintroduces atomistic detail. Finally, multiple extensive fully atomistic simulations with large systems of long macromolecules are employed to examine local dynamics in proximity to graphite. Polyisoprene repeat units arrange close to a parallel configuration with chains exhibiting a distribution of contact lengths. Efficient Monte Carlo algorithms with the coarse-grain model are capable of sampling these distributions for any molecular weight in quantitative agreement with predictions from atomistic models. Furthermore, molecular dynamics simulations with well-equilibrated systems at all length-scales support an increased dynamic heterogeneity that is emerging from both intermolecular interactions with the flat surface and intramolecular cooperativity. This study provides a detailed comprehensive picture of polyisoprene on a flat surface and consists of an effort to characterize such systems in atomistic detail.

Pandey, Yogendra Narayan; Brayton, Alexander; Doxastakis, Manolis, E-mail: edoxastakis@uh.edu [Department of Chemical and Biomolecular Engineering, University of Houston, Houston, Texas 77204 (United States)] [Department of Chemical and Biomolecular Engineering, University of Houston, Houston, Texas 77204 (United States); Burkhart, Craig; Papakonstantopoulos, George J. [Global Materials Science Division, The Goodyear Tire and Rubber Company, Akron, Ohio 44305 (United States)] [Global Materials Science Division, The Goodyear Tire and Rubber Company, Akron, Ohio 44305 (United States)

2014-02-07T23:59:59.000Z

106

EPAC02_graphite.doc STUDY OF GRAPHITE TARGETS INTERACTING WITH THE 24 GeV PROTON  

E-Print Network [OSTI]

materials selected for the experiment are ATJ graphite and the anisotropic carbon-carbon composite. Each, in the first phase of the E951 experiment, graphite and carbon-carbon composite targets were exposed to the AGS to evaluate candidate target materials for the future muon collider/neutrino factory carbon-based solid

McDonald, Kirk

107

Technical and economical considerations of new DRI melting process  

SciTech Connect (OSTI)

The new DRI melting process can effectively and economically produce high quality molten iron. This process utilizes hot charging of DRI directly from a reduction furnace into a dedicated new melting furnace. The molten iron from this DRI premelter can be charged into a steelmaking furnace, such as an electric arc furnace (EAF), where the molten iron, together with other iron sources, can be processed to produce steel. Alternatively the molten iron can be pigged or granulated for off-site merchant sales. Comprehensive research and development of the new process has been conducted including operational process simulation, melting tests using FASTMET DRI, slag technology development, and refractory corrosion testing. This paper describes the process concept, its operational characteristics and further applications of the process.

Ito, Shuzo; Tokuda, Koji; Sammt, F.; Gray, R.

1997-12-31T23:59:59.000Z

108

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

SciTech Connect (OSTI)

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

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

2012-07-01T23:59:59.000Z

109

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

SciTech Connect (OSTI)

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

Romano, T.

1997-09-29T23:59:59.000Z

110

DOI: 10.1002/adma.200702672 Intact Pattern Transfer of Conductive Exfoliated Graphite  

E-Print Network [OSTI]

DOI: 10.1002/adma.200702672 Intact Pattern Transfer of Conductive Exfoliated Graphite Nanoplatelet as biosensors[8,9] or in drug deliv- ery.[10,11] Exfoliated graphite has been incorporated into PEM and other incorporated into PEM.[15­18] Oxidized graphite is created by the acid treatment of graphite, which exfoliates

Lee, Ilsoon

111

Elastomeric behavior of exfoliated graphite, as shown by instrumented indentation testing  

E-Print Network [OSTI]

Elastomeric behavior of exfoliated graphite, as shown by instrumented indentation testing Po for the first time the elastomeric behavior of a non-polymeric material, as observed in exfoliated graphite sliding of the graphite layers within the cell wall of exfoliated graphite. The reversibility is probably

Chung, Deborah D.L.

112

Safety aspects of EB melting  

SciTech Connect (OSTI)

Electron Beam melting technology, along with other vacuum metallurgical technologies, requires special attention to safety involving operation and maintenance of the EB furnace and systems. Although the EB industry has been relatively accident free, the importance of safety awareness and compliance becomes increasingly important. It is very important to provide a safe work environment for employees and economically important to protect the equipment from damage and potential downtime. Safety and accident prevention directly affects overhead costs by keeping accident insurance rates at a minimum. Routine safety requirements will be reviewed and safety aspects requiring extra attention will be addressed. Safety improvements and experiences of furnace users will be shared as examples.

Hainz, L.C. [Hainz Engineering Services, Inc., Albany, OR (United States)

1994-12-31T23:59:59.000Z

113

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

SciTech Connect (OSTI)

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

Blaine Grover

2012-10-01T23:59:59.000Z

114

Low melting high lithia glass compositions and methods  

DOE Patents [OSTI]

The invention relates to methods of vitrifying waste and for lowering the melting point of glass forming systems by including lithia formers in the glass forming composition in significant amounts, typically from about 0.16 wt % to about 11 wt %, based on the total glass forming oxides. The lithia is typically included as a replacement for alkali oxide glass formers that would normally be present in a particular glass forming system. Replacement can occur on a mole percent or weight percent basis, and typically results in a composition wherein lithia forms about 10 wt % to about 100 wt % of the alkali oxide glass formers present in the composition. The present invention also relates to the high lithia glass compositions formed by these methods. The invention is useful for stabilization of numerous types of waste materials, including aqueous waste uranium oxides The decrease in melting point achieved by the present invention desirably prevents volatilization of hazardous or radioactive species during vitrification.

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

2003-09-23T23:59:59.000Z

115

ams graphite target: Topics by E-print Network  

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

OF THE BNL, in the first phase of the E951 experiment, graphite and carbon-carbon composite targets were exposed to the AGS materials selected for the experiment are ATJ...

116

arak iran graphite: Topics by E-print Network  

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

OF THE BNL, in the first phase of the E951 experiment, graphite and carbon-carbon composite targets were exposed to the AGS materials selected for the experiment are ATJ...

117

astm graphite oxidation: Topics by E-print Network  

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

OF THE BNL, in the first phase of the E951 experiment, graphite and carbon-carbon composite targets were exposed to the AGS materials selected for the experiment are ATJ...

118

BGRR-039, Rev. 0 Brookhaven Graphite Research Reactor  

E-Print Network [OSTI]

........................................................................................................ 17 4.0 Waste Management 17 5.0 Lessons Learned 18 6.0 REFERENCES 19 Appendix A Action MemorandumBGRR-039, Rev. 0 Brookhaven Graphite Research Reactor Decommissioning Project FINAL COMPLETION

119

Direct exfoliation of natural graphite into micrometer size few...  

Office of Scientific and Technical Information (OSTI)

Direct exfoliation of natural graphite into micrometer size few layers graphene sheets using ionic liquids Re-direct Destination: Stable high-concentration suspensions (up to 0.95...

120

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

SciTech Connect (OSTI)

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

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

2011-04-01T23:59:59.000Z

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

Experimental thermal conductivity and contact conductance of graphite composites  

E-Print Network [OSTI]

Figure 2. 1 One-Dimensional Heat Transfer by Conduction Across a Plane Wall Figure 2. 2 Fundamental Element for Electrically Based Thermal Model. . . 14 Figure 2. 3 Rectangular Unit Cell Orientation . 14 Figure 2. 4 Model of Parabolic Distribution... a low transverse thermal conductivity, they show better thermal performance than MMC's for some weight-critical applications (Ibrahim, 1992). Graphite/organic compound composites also will be reviewed. Using a high conductivity graphite fiber...

Jackson, Marian Christine

1998-01-01T23:59:59.000Z

122

Non-graphite crucible for high temperature applications  

DOE Patents [OSTI]

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

Holcombe, Cressie E. (Knoxville, TN); Pfeiler, William A. (Norris, TN)

1996-01-01T23:59:59.000Z

123

Non-graphite crucible for high temperature applications  

DOE Patents [OSTI]

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

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

1996-01-09T23:59:59.000Z

124

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

SciTech Connect (OSTI)

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

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

2004-01-01T23:59:59.000Z

125

Electrical and thermal properties of graphite/polyaniline composites  

SciTech Connect (OSTI)

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

126

Optimized Operating Range for Large-Format LiFePO4/Graphite Batteries  

SciTech Connect (OSTI)

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

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

2014-06-01T23:59:59.000Z

127

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

SciTech Connect (OSTI)

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

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

1996-04-08T23:59:59.000Z

128

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

SciTech Connect (OSTI)

The United States Department of Energy’s Next Generation Nuclear Plant (NGNP) Program will be irradiating six 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

129

Internship Contract (Includes Practicum)  

E-Print Network [OSTI]

Internship Contract (Includes Practicum) Student's name-mail: _________________________________________ Internship Agency Contact Agency Name: ____________________________________ Address-mail: __________________________________________ Location of Internship, if different from Agency: ________________________________________________ Copies

Thaxton, Christopher S.

130

Volatilization of Fission Products from Metallic Melts in the Melt-Dilute Treatment Technology Development for Al-Based DOE Spent Nuclear Fuels  

SciTech Connect (OSTI)

The melt-dilute treatment technology is being developed to facilitate the ultimate disposition of highly enriched Al-Base DOE spent nuclear fuels in a geologic repository such as that proposed for Yucca Mountain. Currently, approximately 28 MTHM is expected to be returned to the Savannah River Site from domestic and foreign research reactors. The melt-dilute treatment technology will melt the fuel assemblies to reduce their volume and alloys them with depleted uranium to isotopically dilute the 235U concentration. The resulting alloy is cast into a form for long term geologic repository storage. Benefits accrued from the melt-dilute process include the potential for significant volume reduction; reduced criticality potential, and proliferation concerns. A critical technology element in the development of the melt-dilute process is the development of offgas system requirements. The volatilization of radioactive species during the melting stage of the process primarily constitutes the offgas in this process. Several of the species present following irradiation of a fuel assembly have been shown to be volatile or semi-volatile under reactor core melt-down conditions. Some of the key species that have previously been studied are krypton, iodine, and cesium. All of these species have been shown to volatilize during melting experiments however, the degree to which they are released is highly dependent upon atmosphere, fuel burnup, temperature, and fuel composition. With this in mind an analytical and experimental program has been undertaken to assess the volatility and capture of species under the melt-dilute operating conditions.

Adams, T.

1999-11-18T23:59:59.000Z

131

The Melting of Greenland William H. Lipscomb  

E-Print Network [OSTI]

). AnAn ice capice cap is a mass of glacier ice smaller than 50,000 kmis a mass of glacier ice smaller is negligibleSurface melting is negligible Antarctic ice thicknessAntarctic ice thickness (British Antarctic of the Greenland iceMuch of the Greenland ice sheet may have meltedsheet may have melted Greenland minimum extent

Born, Andreas

132

Purification of tantalum by plasma arc melting  

DOE Patents [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

133

Pump apparatus including deconsolidator  

DOE Patents [OSTI]

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

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

2014-10-07T23:59:59.000Z

134

The contribution of glacier melt to streamflow  

SciTech Connect (OSTI)

Ongoing and projected future changes in glacier extent and water storage globally have lead to concerns about the implications for water supplies. However, the current magnitude of glacier contributions to river runoff is not well known, nor is the population at risk to future glacier changes. We estimate an upper bound on glacier melt contribution to seasonal streamflow by computing the energy balance of glaciers globally. Melt water quantities are computed as a fraction of total streamflow simulated using a hydrology model and the melt fraction is tracked down the stream network. In general, our estimates of the glacier melt contribution to streamflow are lower than previously published values. Nonetheless, we find that globally an estimated 225 (36) million people live in river basins where maximum seasonal glacier melt contributes at least 10% (25%) of streamflow, mostly in the High Asia region.

Schaner, Neil; Voisin, Nathalie; Nijssen, Bart; Lettenmaier, D. P.

2012-09-13T23:59:59.000Z

135

Treatment of Irradiated Graphite from French Bugey Reactor - 13424  

SciTech Connect (OSTI)

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

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

2013-07-01T23:59:59.000Z

136

alkali carbonate melts: Topics by E-print Network  

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

8 Glass Transition and Melting Behavior of Carbon Fiber Reinforced Thermoplastic Composite, Studied by Materials Science Websites Summary: Glass Transition and Melting...

137

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

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

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

138

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

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

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

139

Complex systems influence melting of Greenland ice sheet  

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

Complex systems influence melting of Greenland ice sheet Complex systems influence melting of Greenland ice sheet International research team's field work shows that, well, things...

140

Melting of superheated crystals initiates on vacancies  

E-Print Network [OSTI]

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

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

2010-07-24T23:59:59.000Z

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

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

SciTech Connect (OSTI)

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

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

2012-06-08T23:59:59.000Z

142

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

143

Graphite Foams for Lithium-Ion Battery Current Collectors  

SciTech Connect (OSTI)

Graphite open-cell foams, with their very high electronic and thermal conductivities, may serve as high surface area and corrosion resistant current collectors for lithium-ion batteries. As a proof of principle, cathodes were prepared by sintering carbon-coated LiFePO4 particles into the porous graphite foams. Cycling these cathodes in a liquid electrolyte cell showed promising performance even for materials and coatings that have not been optimized. The specific capacity is not limited by the foam structure, but by the cycling performance of the coated LiFePO4 particles. Upon extended cycling for more than 100 deep cycles, no loss of capacity is observed for rates of C/2 or less. The uncoated graphite foams will slowly intercalate lithium reversibly at potentials less than 0.2 volts versus lithium.

Dudney, Nancy J [ORNL; Tiegs, Terry N [ORNL; Kiggans, Jim [ORNL; Jang, Young-Il [ORNL; Klett, James William [ORNL

2007-01-01T23:59:59.000Z

144

Melt and vapor characteristics in an electron beam evaporator  

SciTech Connect (OSTI)

We compare the free surface temperatures T{sub s}, calculated by two methods, in cerium or copper evaporation experiments. The first method considers properties of the melt: by an empirical law we take into account turbulent thermal convection, instabilities and craterization of the free surface. The second method considers the vapor flow expansion and connects T{sub s} to the measured terminal parallel temperature and the terminal mean parallel velocity of the vapor jet, by Direct Simulation Monte Carlo calculations including an atom-atom inelastic collision algorithm. The agreement between the two approaches is better for cerium than for copper in the high craterization case. The analysis, from the point of view of the properties of the melt, of the terminal parameters of the vapor jet for the high beam powers shows that T{sub s} and the Knudsen number at the vapor source reach a threshold when the beam power increases.

Blumenfeld, L.; Fleche, J.L.; Gonella, C. [DCC/DPE/SPEA Centre d`Etudes de Saclay, Gif-sur-Yvette (France)

1994-12-31T23:59:59.000Z

145

On modifying properties of polymeric melts by nanoscopic particles  

E-Print Network [OSTI]

We study geometric and energetic factors that partake in modifying properties of polymeric melts via inserting well-dispersed nanoscopic particles (NP). Model systems are polybutadiene melts including 10-150 atom atomic clusters (0.1-1.5% v/v). We tune interactions between chains and particle by van der Waals terms. Using molecular dynamics we study equilibrium fluctuations and dynamical properties at the interface. Effect of bead size and interaction strength both on volume and volumetric fluctuations is manifested in mechanical properties, quantified here by bulk modulus, K. Tuning NP size and non-bonded interactions results in ~15% enhancement in K by addition of a maximum of 1.5% v/v NP.

Canan Atilgan; Ibrahim Inanc; Ali Rana Atilgan

2012-07-09T23:59:59.000Z

146

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

SciTech Connect (OSTI)

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

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

2014-06-01T23:59:59.000Z

147

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

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

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

148

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

E-Print Network [OSTI]

of mesoporosity. The high-temperature treatment led to a marked enhancement of graphitic ordering, which, and manufacturing of electrochemical dou- ble-layer capacitors and Li-ion batteries. Graphitic carbons exhibit

149

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

150

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

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

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

151

Gelcasting polymeric precursors for producing net-shaped graphites  

DOE Patents [OSTI]

The present invention discloses a method for molding complex and intricately shaped high density monolithic carbon, carbon-carbon, graphite, and thermoplastic composites using gelcasting technology. The method comprising a polymeric carbon precursor, a solvent, a dispersant, an anti-foaming agent, a monomer system, and an initiator system. The components are combined to form a suspension which is poured into a mold and heat-treated to form a thermoplastic part. The thermoplastic part can then be further densified and heat-treated to produce a high density carbon or graphite composite. The present invention also discloses the products derived from this method.

Klett, James W. (Knoxville, TN); Janney, Mark A. (Knoxville, TN)

2002-01-01T23:59:59.000Z

152

Equation of State of Graphite-like BC,  

SciTech Connect (OSTI)

The compressibility of turbostratic boron-substituted graphite (t-BC) was measured up to 12 GPa at room temperature using energy-dispersive X-ray powder diffraction with synchrotron radiation. A fit to the experimental p-V data using Birch-Murnaghan equation of state gives values of the t-BC bulk modulus 23(2) GPa and its pressure derivative 8.0(6). These values point to a higher compressibility of t-BC as compared to turbostratic graphite.

Solozhenko,V.; Kurakevych, O.; Solozhenko, E.; Chen, J.; Parise, J.

2006-01-01T23:59:59.000Z

153

Electronic properties of graphite in tilted magnetic fields  

SciTech Connect (OSTI)

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

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

2014-05-15T23:59:59.000Z

154

Microfabrication of freestanding metal structures released from graphite substrates.  

SciTech Connect (OSTI)

A sacrificial layer is usually used to release electroformed microstructures. Because of the chemistry applied to the sacrificial layer, only a limited number of metals can be used for electroforming. A novel method to fabricate freestanding electroformed copper structures is presented. A graphite substrate allows the release of the metal part, by abrasive removal of the graphite after electroforming. Results on fabrication of high-aspect-ratio freestanding copper grids are presented; these can be used as x-ray collimator in medical imaging to reduce scattered radiation. This process has potential application to the fabrication of injection molds and microparts on pick-and-place carriers for microelectromechanical systems (MEMS).

Makarova, O. V.; Tang, C.-M.; Mancini, D. C.; Moldovan, N.; Divan, R.; Ryding, D. G.; Lee, R. H.

2002-02-22T23:59:59.000Z

155

Revisiting the domain model for lithium intercalated graphite  

SciTech Connect (OSTI)

In this Letter, we study the stability of the domain model for lithium intercalated graphite in stages III and II by means of Density Functional Theory and Kinetic Lattice Monte Carlo simulations. We find that the domain model is either thermodynamically or kinetically stable when compared to the standard model in stages III and II. The existence of domains in the intercalation sequence is well supported by recent high resolution transmission electron microscope observations in lithiated graphite. Moreover, we predict that such domain staging sequences leads to a wide range of diffusivity as reported in experiments.

Krishnan, Sridevi; Brenet, Gilles; Caliste, Damien; Genovese, Luigi; Deutsch, Thierry; Pochet, Pascal, E-mail: pascal.pochet@cea.fr [Laboratoire de Simulation Atomistique (L-Sim), SP2M, UMR-E CEA/UJF-Grenoble 1, INAC, Grenoble F-38054 (France)] [Laboratoire de Simulation Atomistique (L-Sim), SP2M, UMR-E CEA/UJF-Grenoble 1, INAC, Grenoble F-38054 (France); Machado-Charry, Eduardo [Laboratoire de Simulation Atomistique (L-Sim), SP2M, UMR-E CEA/UJF-Grenoble 1, INAC, Grenoble F-38054 (France) [Laboratoire de Simulation Atomistique (L-Sim), SP2M, UMR-E CEA/UJF-Grenoble 1, INAC, Grenoble F-38054 (France); Nanosciences Fondation, 23 rue des martyrs, 38000 Grenoble (France)

2013-12-16T23:59:59.000Z

156

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

SciTech Connect (OSTI)

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

Principal Investigator Kent Peaslee; Co-PIà ƒ  ¢Ã ‚  € à ‚  ™ s: Von Richards, Jeffrey Smith

2012-07-31T23:59:59.000Z

157

PURIFICATION OF IRIDIUM BY ELECTRON BEAM MELTING  

SciTech Connect (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

158

Josephson vortex lattice melting in Bi-2212  

SciTech Connect (OSTI)

The B-T diagram of Josephson vortex lattice melting in Bi-2212 is analyzed (B is magnetic induction parallel to the layers, T is temperature). It is shown that the Josephson vortex lattice melting at B > B* = 0.6-0.7 T is associated with Berezinsky-Kosterlitz-Thouless transition in individual Bi-2212 superconducting layers and is a second-order phase transition.

Latyshev, Yu. I.; Pavlenko, V. N., E-mail: vit@cplire.ru; Orlov, A. P. [Russian Academy of Sciences, Institute of Radio Engineering and Electronics (Russian Federation)

2007-07-15T23:59:59.000Z

159

Metal melting for volume reduction and recycle  

SciTech Connect (OSTI)

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

Miller, R.L.

1987-03-27T23:59:59.000Z

160

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

E-Print Network [OSTI]

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

Nabben, Reinhard

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

Non-oxidative intercalation and exfoliation of graphite by Brnsted acids  

E-Print Network [OSTI]

Non-oxidative intercalation and exfoliation of graphite by Brønsted acids Nina I. Kovtyukhova1 and the polarizable graphene sheets. The intercalated graphites readily exfoliate in dimethylformamide to give, with loss of conductivity9,10. These highly oxidized graphite compounds can be exfoliated to form

162

SILICATE MELT PROPERTIES AND VOLCANIC Youxue Zhang,1,2  

E-Print Network [OSTI]

SILICATE MELT PROPERTIES AND VOLCANIC ERUPTIONS Youxue Zhang,1,2 Zhengjiu Xu,2 Mengfan Zhu,1 2007. [1] Knowledge about the properties of silicate melts is needed by volcanologists and petrologists and diffusivity of volatile components in silicate melts, silicate melt viscosity, and the fragmentation condition

Zhang, Youxue

163

Retrieval of Melt Pond Coverage from MODIS using Optimal Estimation   

E-Print Network [OSTI]

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

Dodd, Emma

2011-11-24T23:59:59.000Z

164

Corrosion quantification test for flanges with graphite-based gaskets  

SciTech Connect (OSTI)

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

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

2000-04-01T23:59:59.000Z

165

Author's personal copy Reactivity of lithium exposed graphite surface  

E-Print Network [OSTI]

on the surface [18]. Hence the effect of lithium on plasma­wall interactions is expected to dependAuthor's personal copy Reactivity of lithium exposed graphite surface S.S. Harilal a, *, J in fusion devices [1­5]. For example, wall conditioning with thin lithium layers gives rise to low hydrogen

Harilal, S. S.

166

THORIUM FUEL CYCLES: A GRAPHITE-MODERATED MOLTEN SALT REACTOR  

E-Print Network [OSTI]

THORIUM FUEL CYCLES: A GRAPHITE-MODERATED MOLTEN SALT REACTOR VERSUS A FAST SPECTRUM SOLID FUEL is to compare two main options dedicated to long-term energy production with Thorium: solid fuel with fast its be- haviour until it reaches the 232Th/233U equilibrium from two di erent starting fuels: 232Th

Paris-Sud XI, Université de

167

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

168

Ultra slow EB melting to reduce reactor cladding  

SciTech Connect (OSTI)

A process is described for making an electron beam melted fuel element liner material from sponge zirconium, the process comprising: electron beam melting sponge zirconium at a melting rate of less than 1 inch per hour to form an electron beam melted zirconium material containing less than 300 ppm iron, less than 400 ppm oxygen, and less than 5 ppm aluminum; and alloying the electron beam melted zirconium in a vacuum arc furnace with 0.1-2.0 weight percent of tin.

Worcester, S.A.; Woods, C.R.; Galer, G.S.; Propst, R.L.

1989-03-28T23:59:59.000Z

169

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

170

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

SciTech Connect (OSTI)

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

171

Scrap uranium recycling via electron beam melting  

SciTech Connect (OSTI)

A program is underway at the Lawrence Livermore National Laboratory (LLNL) to recycle scrap uranium metal. Currently, much of the material from forging and machining processes is considered radioactive waste and is disposed of by oxidation and encapsulation at significant cost. In the recycling process, uranium and uranium alloys in various forms will be processed by electron beam melting and continuously cast into ingots meeting applicable specifications for virgin material. Existing vacuum processing facilities at LLNL are in compliance with all current federal and state environmental, safety and health regulations for the electron beam melting and vaporization of uranium metal. One of these facilities has been retrofitted with an auxiliary electron beam gun system, water-cooled hearth, crucible and ingot puller to create an electron beam melt furnace. In this furnace, basic process R&D on uranium recycling will be performed with the goal of eventual transfer of this technology to a production facility.

McKoon, R.

1993-11-01T23:59:59.000Z

172

Investigation of MSWI fly ash melting characteristic by DSC-DTA  

SciTech Connect (OSTI)

The melting process of MSWI (Municipal Solid Waste Incineration) fly ash has been studied by high-temperature DSC-DTA experiments. The experiments were performed at a temperature range of 20-1450 deg. C, and the considerable variables included atmosphere (O{sub 2} and N{sub 2}), heating rates (5 deg. C/min, 10 deg. C/min, 20 deg. C/min) and CaO addition. Three main transitions were observed during the melting process of fly ash: dehydration, polymorphic transition and fusion, occurring in the temperature range of 100-200 deg. C, 480-670 deg. C and 1101-1244 deg. C, respectively. The apparent heat capacity and heat requirement for melting of MSWI fly ash were obtained by DSC (Differential Scanning Calorimeter). A thermodynamic modeling to predict the heat requirements for melting process has been presented, and it agrees well with the experimental data. Finally, a zero-order kinetic model of fly ash melting transition was established. The apparent activation energy of MSWI fly ash melting transition was obtained.

Li, Rundong [Institute of Clean Energy and Environmental Engineering, Liaoning Key Laboratory of Clean Energy, Shenyang Institute of Aeronautical Engineering, Shenyang 110136 (China)], E-mail: leerd@mail.tsinghua.edu.cn; Wang, Lei; Yang, Tianhua; Raninger, Bernhard [Institute of Clean Energy and Environmental Engineering, Liaoning Key Laboratory of Clean Energy, Shenyang Institute of Aeronautical Engineering, Shenyang 110136 (China)

2007-07-01T23:59:59.000Z

173

The evaluation of cleanness by electron beam button melting and other methods - a review  

SciTech Connect (OSTI)

The accurate determination of both the number and size distribution of inclusions in superclean materials is difficult. Some of the methods used for nickel-base alloys and steels are briefly reviewed; all the methods have problems associated with them. Electron Beam Button Melting (EBBM) and the new technique of Cold Crucible Melting (CCM) as methods of concentrating the inclusions offer the advantage of sampling large volumes of material quickly. The number, size and composition of the entrapped particles can be determined using Scanning Electron Microscopy, (SEM). Both techniques may be used for semi-quantitative assessment such as ranking different heats of materials but care is required with quantitative evaluation. The mechanisms controlling inclusion collection efficiency for EBBM are reviewed including investigations with samples doped with particles of known size and number and assessing recovery rates on button rafts. In EBBM low power melting and solidification programmes are recommended to minimise the melting or sintering of the inclusions and melt compositions, particularly sulphur, have a major effect on the efficiency of inclusion collection. Under favourable conditions collection efficiencies of 90-95% can be achieved. As a result of these types of studies a draft code of practice for the evaluation of alloy cleanness by EBBM has been prepared. Cold crucible melting is an attractive alternative to EBBM for cleanness evaluation. Trials have established that collection efficiencies of 80-85% can be achieved with this method but SEM examination of the buttons is more time consuming compared with EBBM.

Quested, P.N.; Hayes, D.M. [National Physical Lab., Middlesex (United Kingdom)

1994-12-31T23:59:59.000Z

174

Method and apparatus for melting metals  

DOE Patents [OSTI]

A method and apparatus for melting metals uses microwave energy as the primary source of heat. The metal or mixture of metals are placed in a ceramic crucible which couples, at least partially, with the microwaves to be used. The crucible is encased in a ceramic casket for insulation and placed within a microwave chamber. The chamber may be evacuated and refilled to exclude oxygen. After melting, the crucible may be removed for pouring or poured within the chamber by dripping or running into a heated mold within the chamber. Apparent coupling of the microwaves with softened or molten metal produces high temperatures with great energy savings.

Moore, Alan F.; Schechter, Donald E.; Morrow, Marvin Stanley

2006-03-14T23:59:59.000Z

175

Low melting high lithia glass compositions and methods  

DOE Patents [OSTI]

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

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

2000-01-01T23:59:59.000Z

176

Low melting high lithia glass compositions and methods  

DOE Patents [OSTI]

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

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

2004-11-02T23:59:59.000Z

177

Low melting high lithia glass compositions and methods  

DOE Patents [OSTI]

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

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

2003-10-07T23:59:59.000Z

178

Evaluation of replacement thread lubricants for red lead and graphite in mineral oil  

SciTech Connect (OSTI)

Eight commercially available thread lubricants were evaluated to determine the best replacement for Red Lead and Graphite in Mineral Oil (RLGMO). The evaluation included coefficient of friction testing, high temperature anti-seizing testing, room temperature anti-galling testing, chemical analysis for detrimental impurities, corrosion testing, off-gas testing, and a review of health and environmental factors. The coefficient of friction testing covered a wide variety of factors including stud, nut, and washer materials, sizes, manufacturing methods, surface coatings, surface finishes, applied loads, run-in cycles, and relubrication. Only one lubricant, Dow Corning Molykote P37, met all the criteria established for a replacement lubricant. It has a coefficient of friction range similar to RLGMO. Therefore, it can be substituted directly for RLGMO without changing the currently specified fastener torque values for the sizes, materials and conditions evaluated. Other lubricants did not perform as well as Molykote P37 in one or more test or evaluation categories.

Jungling, T.L.; Rauth, D.R.; Goldberg, D.

1998-04-30T23:59:59.000Z

179

Local diamagnetic susceptibility of quasi-two-dimensional graphite  

SciTech Connect (OSTI)

A sample of quasi-two-dimensional graphite (QTDG) whose magnetic properties are described within the Dirac fermion model is investigated by the nuclear magnetic resonance (NMR) and scanning tunneling microscopy (STM) techniques. The broad spectrum of the sample points to a large dispersion of crystallite sizes in this system, which is also confirmed by STM data. It is established that the local diamagnetic susceptibility may substantially exceed the average value over the sample and reaches an abnormally high value of -1.3 Multiplication-Sign 10{sup -4} emu/g at T = 4.2 K, which is greater than the corresponding value of highly oriented graphite by a factor of four.

Nikolaev, E. G., E-mail: nikolaev@kapitza.ras.ru [Russian Academy of Sciences, Kapitsa Institute for Physical Problems (Russian Federation); Kotosonov, A. S. [OAO NIIgrafit (Russian Federation)] [OAO NIIgrafit (Russian Federation); Shalashugina, E. A.; Troyanovskii, A. M. [Russian Academy of Sciences, Kapitsa Institute for Physical Problems (Russian Federation)] [Russian Academy of Sciences, Kapitsa Institute for Physical Problems (Russian Federation); Tsebro, V. I. [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation)] [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation)

2013-08-15T23:59:59.000Z

180

Catalytic graphitization of carbon aerogels by transition metals  

SciTech Connect (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

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

Cryogenic Thermal Expansion of Y-12 Graphite Fuel Elements  

SciTech Connect (OSTI)

Thermal expansion measurements betwccn 20°K and 300°K were made on segments of three uranium-loaded Y-12 uncoated graphite fuel elements. The thermal expansion of these fuel elements over this temperature range is represented by the equation: {Delta}L/L = -39.42 x 10{sup -5} + 1.10 x 10{sup -7} T + 6.47 x 10{sup -9} T{sup 2} - 8.30 x 10{sup -12} T{sup 3}.

Eash, D. T.

2013-07-08T23:59:59.000Z

182

Pulsed-electron-beam melting of Fe  

SciTech Connect (OSTI)

Pulsed (50 nsec) electron beams with deposited energies of 1.1 to 2.3 J/cm/sup 2/ have been used to rapidly melt a surface layer of Fe. Calculations show that this range of energies produces melt depths from 0.4 to 1.2 ..mu..m and melt times of 100 to 500 nsec. Optical microscopy and SEM of pulse treated polycrystalline foils show slip traces, as well as a general smoothing of surface features which shows that melting has occurred. TEM shows that the resolidified material is bcc, and that the material within a grain is epitaxial with the substrate. TEM also shows slip traces along (110) planes, as well as a high density of dislocations, both extended and loop. At the highest energy, subgrain boundaries are observed. Some samples were implanted with 1 x 10/sup 16/ Sn/cm/sup 2/ at 150 keV. After pulse treatment, the Sn depth profile was observed to have broadened, consistent with liquid phase diffusion. The Sn had the unexpected effect of suppressing slip at the sample surface.

Knapp, J.A.; Follstaedt, D.M.

1981-01-01T23:59:59.000Z

183

Analysis of an EBeam melting process  

SciTech Connect (OSTI)

Electron-Beam (EBeam) melting furnaces are routinely used to minimize the occurrence of second-phase particles in the processing of segregation-sensitive alloys. As one part of the process, a circulating electron beam impinges the surface of a crucible melt pool to help control the shape of the solidification front below. By modeling melt pool hydrodynamics, heat transfer, and the shape of solidification boundaries, we plan to optimize the dwell pattern of the beam so that the material solidifies with a composition as spatially homogeneous as possible. Both two-and three-dimensional models are being pursued with FIDAP 5.02, the former serving as a test bed for various degrees of model sophistication. A heat flux distribution is specified on the top of the domain to simulate the EBeam dwell pattern. In two dimensions it is found that an inertially-driven recirculation in the melt pool interacts with a counter-rotating buoyancy-driven recirculation, and that both recirculation influence heavily the shape of the solidification front. In three dimensions the inertial cell decays quickly with distance from the position of the inlet stream. Because the Rayleigh number can exceed 10{sup 7} for materials and operating conditions of interest, stability and the possibility of spontaneous transients are explored. 1 refs., 3 figs.

Schunk, P.R.

1991-01-01T23:59:59.000Z

184

Energy Savings in Electric Arc Furnace Melting  

E-Print Network [OSTI]

Arc furnace melting which at one time was almost exclusively used to produce alloy steel and steel castings is now widely accepted in the industry as an efficient process to produce all types of steel and iron. Presently, about 28% of steel...

Lubbeck, W.

1982-01-01T23:59:59.000Z

185

B{sub 4}C-SiC reaction-sintered coatings on graphite plasma facing components  

SciTech Connect (OSTI)

Boron carbide plus silicon carbide (B{sub 4}C-SiC) reaction-sintered coatings for use on graphite plasma-facing components were developed. Such coatings are of interest in TEXTOR tokamak limiter-plasma interactions as a means of reducing carbon erosion, of providing a preferred release of boron for oxygen gettering, and of investigating silicon`s effect on radiative edge phenomena. Specimens evaluated had (a) either Ringsdorfwerke EK 98 graphite or Le Carbon Lorraine felt-type AEROLOR A05 CFC substrates; (b) multiphase coatings, comprised of B{sub 4}C, Sic, and graphite; (c) nominal coating compositions of 69 wt.-% B{sub 4}C + 31 wt.-% SiC; and (d) nominal coating thicknesses between 250 and 775 {mu}m. Coated coupons were evaluated by high heat flux experiments in the JUDITH (electron beam) test facility at KFA. Simulated disruptions, with energy densities up to 10 MJm{sup {minus}2}, and normal operation simulations, with power densities up to 12 MWm{sup {minus}2}, were conducted. The coatings remained adherent; at the highest levels tested, minor changes occurred, including localized remelting, modification of the crystallographic phases, occasional microcracking, and erosion.

Valentine, P.G.; Trester, P.W. [General Atomics, San Diego, CA (United States); Winter, J. [Kernforschungsanlage Juelich GmbH (Germany)] [and others

1994-05-01T23:59:59.000Z

186

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

187

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

188

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

189

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

190

Melt spreading code assessment, modifications, and application to the EPR core catcher design.  

SciTech Connect (OSTI)

The Evolutionary Power Reactor (EPR) is under consideration by various utilities in the United States to provide base load electrical production, and as a result the design is undergoing a certification review by the U.S. Nuclear Regulatory Commission (NRC). The severe accident design philosophy for this reactor is based upon the fact that the projected power rating results in a narrow margin for in-vessel melt retention by external cooling of the reactor vessel. As a result, the design addresses ex-vessel core melt stabilization using a mitigation strategy that includes: (1) an external core melt retention system to temporarily hold core melt released from the vessel; (2) a layer of 'sacrificial' material that is admixed with the melt while in the core melt retention system; (3) a melt plug in the lower part of the retention system that, when failed, provides a pathway for the mixture to spread to a large core spreading chamber; and finally, (4) cooling and stabilization of the spread melt by controlled top and bottom flooding. The overall concept is illustrated in Figure 1.1. The melt spreading process relies heavily on inertial flow of a low-viscosity admixed melt to a segmented spreading chamber, and assumes that the melt mass will be distributed to a uniform height in the chamber. The spreading phenomenon thus needs to be modeled properly in order to adequately assess the EPR design. The MELTSPREAD code, developed at Argonne National Laboratory, can model segmented, and both uniform and nonuniform spreading. The NRC is thus utilizing MELTSPREAD to evaluate melt spreading in the EPR design. MELTSPREAD was originally developed to support resolution of the Mark I containment shell vulnerability issue. Following closure of this issue, development of MELTSPREAD ceased in the early 1990's, at which time the melt spreading database upon which the code had been validated was rather limited. In particular, the database that was utilized for initial validation consisted of: (1) comparison to an analytical solution for the dam break problem, (2) water spreading tests in a 1/10 linear scale model of the Mark I containment by Theofanous et al., and (3) steel spreading tests by Suzuki et al. that were also conducted in a geometry similar to the Mark I. The objective of this work was to utilize the MELTSPREAD code to check the assumption of uniform melt spreading in the EPR core catcher design. As a starting point for the project, the code was validated against the worldwide melt spreading database that emerged after the code was originally written in the very early 1990's. As part of this exercise, the code was extensively modified and upgraded to incorporate findings from these various analytical and experiment programs. In terms of expanding the ability of the code to analyze various melt simulant experiments, the options to input user-specified melt and/or substrate material properties was added. The ability to perform invisicid and/or adiabatic spreading analysis was also added so that comparisons with analytical solutions and isothermal spreading tests could be carried out. In terms of refining the capability to carry out reactor material melt spreading analyses, the code was upgraded with a new melt viscosity model; the capability was added to treat situations in which solid fraction buildup between the liquidus-solidus is non-linear; and finally, the ability to treat an interfacial heat transfer resistance between the melt and substrate was incorporated. This last set of changes substantially improved the predictive capability of the code in terms of addressing reactor material melt spreading tests. Aside from improvements and upgrades, a method was developed to fit the model to the various melt spreading tests in a manner that allowed uncertainties in the model predictions to be statistically characterized. With these results, a sensitivity study was performed to investigate the assumption of uniform spreading in the EPR core catcher that addressed parametric variations in: (1) melt pour mass, (2) melt composition, (3) me

Farmer, M. T .; Nuclear Engineering Division

2009-03-30T23:59:59.000Z

191

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

192

Laser-induced dehydration of graphite oxide coatings on polymer substrates  

SciTech Connect (OSTI)

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

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

2014-05-15T23:59:59.000Z

193

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

SciTech Connect (OSTI)

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

Eapen, Jacob; Murty, Korukonda; Burchell, Timothy

2014-06-02T23:59:59.000Z

194

Hydrous silicate melt at high pressure Mainak Mookherjee1  

E-Print Network [OSTI]

LETTERS Hydrous silicate melt at high pressure Mainak Mookherjee1 , Lars Stixrude2 & Bijaya Karki3 The structure and physical properties of hydrous silicate melts and the solubility of water in melts over most in structure to our finding that the water­silicate system becomes increasingly ideal at high pressure: we find

Stixrude, Lars

195

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

SciTech Connect (OSTI)

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

196

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

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

6 Revision 0 Engineering Services for the Next Generation Nuclear Plant (NGNP) with Hydrogen Production Test Plan for Reactor Graphite Elements Prepared by General Atomics for the...

197

E-Print Network 3.0 - air-cooled graphite reactors Sample Search...  

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

kernesikkerhedsforskning Norrnar kjarnryggisrannsknir Summary: the Nordic region. Windscale2 Two air-cooled graphite moderated metal U reactors operated at Windscale from......

198

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

E-Print Network [OSTI]

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

Drummond, Kevin P.

2012-01-01T23:59:59.000Z

199

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

E-Print Network [OSTI]

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

Collins, Philip G

2009-01-01T23:59:59.000Z

200

E-Print Network 3.0 - advanced gas cooled graphite moderated...  

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

at Chicago's Stagg Field and the X-IO graphite reactor at Oak Ridge). The Los Alamos Water Boiler... for neutron multiplication experiments at moderate power. They also...

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


201

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

SciTech Connect (OSTI)

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

Prabhat K. Tripathy; Derek J. Fray

2011-11-01T23:59:59.000Z

202

Specific heat in two-dimensional melting  

E-Print Network [OSTI]

We report the specific heat $c_N$ around the melting transition(s) of micrometer-sized superparamagnetic particles confined in two dimensions, calculated from fluctuations of positions and internal energy, and corresponding Monte Carlo simulations. Since colloidal systems provide single particle resolution, they offer the unique possibility to compare the experimental temperatures of peak position of $c_N(T)$ and symmetry breaking, respectively. While order parameter correlation functions confirm the Kosterlitz-Thouless-Halperin-Nelson-Young melting scenario where translational and orientational order symmetries are broken at different temperatures with an intermediate so called hexatic phase, we observe a single peak of the specific heat within the hexatic phase, with excellent agreement between experiment and simulation. Thus, the peak is not associated with broken symmetries but can be explained with the total defect density, which correlates with the maximum increase of isolated dislocations. The absence of a latent heat strongly supports the continuous character of both transitions.

Sven Deutschländer; Antonio M. Puertas; Georg Maret; Peter Keim

2014-05-14T23:59:59.000Z

203

Regelation: why does ice melt under pressure?  

E-Print Network [OSTI]

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

Chang Q Sun

2015-01-28T23:59:59.000Z

204

Regelation: why does ice melt under pressure?  

E-Print Network [OSTI]

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

Sun, Chang Q

2015-01-01T23:59:59.000Z

205

Low cation coordination in oxide melts  

SciTech Connect (OSTI)

The complete set of Faber-Ziman partial pair distribution functions for a rare earth oxide liquid were measured for the first time by combining aerodynamic levitation, neutron diffraction, high energy x-ray diffraction and isomorphic substitution using Y2 O3 and Ho2 O3 melts. The average Y- O coordination is measured to be 5.5(2), which is significantly less than the octahedral coordination of crystalline Y2 O3 (or Ho2 O3 ). Investigation of high temperature La2 O3 , ZrO2 , SiO2 , and Al2 O3 melts by x-ray diffraction and molecular dynamics simulations also show lower-than-crystal cation- oxygen coordination. These measurements suggest a general trend towards lower M-O coordination compared to their crystalline counterparts. It is found that this coordination number drop is larger for lower field strength, larger radius cations and is negligible for high field strength (network forming) cations. These findings have broad implications for predicting the local structure and related physical properties of metal-oxide melts and oxide glasses.

Skinner, Lawrie [State University of New York, Stony Brook] [State University of New York, Stony Brook; Benmore, Chris J [Argonne National Laboratory (ANL)] [Argonne National Laboratory (ANL); Du, Jincheng [University of North Texas] [University of North Texas; Weber, Richard [Argonne National Laboratory (ANL)] [Argonne National Laboratory (ANL); Neuefeind, Joerg C [ORNL] [ORNL; Tumber, Sonia [Materials Development, Inc., Evanston, IL] [Materials Development, Inc., Evanston, IL; Parise, John B [Stony Brook University (SUNY)] [Stony Brook University (SUNY)

2014-01-01T23:59:59.000Z

206

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

SciTech Connect (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

207

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

SciTech Connect (OSTI)

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

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

1990-06-15T23:59:59.000Z

208

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

209

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

210

Method of fabricating silicon carbide coatings on graphite surfaces  

DOE Patents [OSTI]

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

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

1994-07-26T23:59:59.000Z

211

Compression induced delamination in a unidirectional graphite/epoxy composite  

E-Print Network [OSTI]

110 Vl Table LIST OF TABLES Page 1 Compression Delamination Test Results P = 19. 79 N (4, 45 lb) E* = 136. 55 GPa (19. 8E6 Psi) s 2 Compression Delamination Test Results P = 24. OZ N (5. 4 lb) E = 136. 55 GPa (19. 8E6 Psi) s 3 Compression... Involving Different Crack Surface Displacements 3 fl . P /P 4 f2 vs. Pa/Pc 5 f3 vs. Pa/Pc 6 f4 vs. Pa/Pc 7 Test Specimen 8 Specimen Geometry 9 Cure Cycle for ASl/3502 Graphite/Epoxy Panels 10 Split Laminate in the Form of a Double-Cantilever Beam...

Earley, John W.

1981-01-01T23:59:59.000Z

212

Molecular Dynamics Simulation of Collisions between Hydrogen and Graphite  

E-Print Network [OSTI]

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.

A. Ito; H. Nakamura

2006-04-26T23:59:59.000Z

213

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

214

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

SciTech Connect (OSTI)

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

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

2000-09-30T23:59:59.000Z

215

Emission characteristics and dynamics of C2 from laser produced graphite plasma  

E-Print Network [OSTI]

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

Harilal, S. S.

216

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

E-Print Network [OSTI]

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

Boyer, Edmond

217

Study of polypyrrole graphite composite as anode material for secondary lithium-ion batteries  

E-Print Network [OSTI]

Study of polypyrrole graphite composite as anode material for secondary lithium-ion batteries of the composite. The composite material has been studied for specific discharge capacity, coulombic efficiency for the Li-ion battery. Of various carbon materials that have been tried, graphite is favored because it (i

Popov, Branko N.

218

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

SciTech Connect (OSTI)

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

219

Synthesis of graphene-based nanosheets via chemical reduction of exfoliated graphite oxide  

E-Print Network [OSTI]

Synthesis of graphene-based nanosheets via chemical reduction of exfoliated graphite oxide Sasha of a colloidal suspension of exfoliated graphene oxide sheets in water with hydrazine hydrate results at the nanoscale if graphite can be exfoliated into thin nanoplatelets, and even down to the single graphene sheet

220

Direct Physical Exfoliation of Few-Layer Graphene from Graphite Grown on a Nickel Foil Using  

E-Print Network [OSTI]

Direct Physical Exfoliation of Few-Layer Graphene from Graphite Grown on a Nickel Foil Using Physical graphene exfoliation from graphite using optimized PDMS PACS codes: 68.65.Pq, 81.05.ue, 81.05.uf for the site-specific direct physical exfoliation of few-layer graphene sheets from cheap and easily

Maruyama, Shigeo

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

Simple Fabrication of a Highly Sensitive Glucose Biosensor Using Enzymes Immobilized in Exfoliated Graphite Nanoplatelets Nafion  

E-Print Network [OSTI]

Simple Fabrication of a Highly Sensitive Glucose Biosensor Using Enzymes Immobilized in Exfoliated for the development of a glucose biosensor. Exfoliated graphite nanoplatelets (xGnP) were tested to enhance to 100s of dollars per gram) often makes them cost-prohibitive for some applications. Exfoliated graphite

Lee, Ilsoon

222

Adsorption of supramolecular building blocks on graphite: A force field and density functional theory study  

E-Print Network [OSTI]

that both adsorption energies as well as adsorption geometries of or- ganic molecules on graphite determined studies in which the adsorption energies of supramolecular building blocks are measured.12 This hampersAdsorption of supramolecular building blocks on graphite: A force field and density functional

Pfeifer, Holger

223

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

224

Graphite-to-diamond transformation induced by ultrasound cavitation A.Kh. Khachatryan a,c  

E-Print Network [OSTI]

Graphite-to-diamond transformation induced by ultrasound cavitation A.Kh. Khachatryan a,c , S microcrystals have been synthesized using ultrasonic cavitation of a suspension of hexagonal graphite in various. © 2008 Elsevier B.V. All rights reserved. Keywords: Ultrasound cavitation; Microcrystalline diamond 1

Bristol, University of

225

Generation of graphitic soot by an urban fire storm  

SciTech Connect (OSTI)

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

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

1987-01-01T23:59:59.000Z

226

Benchmarking of Graphite Reflected Critical Assemblies of UO2  

SciTech Connect (OSTI)

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

Margaret A. Marshall; John D. Bess

2011-11-01T23:59:59.000Z

227

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

SciTech Connect (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

228

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

SciTech Connect (OSTI)

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

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

2014-05-05T23:59:59.000Z

229

The role of oxygen in the uptake of deuterium in lithiated graphite  

SciTech Connect (OSTI)

We investigate the mechanism of deuterium retention by lithiated graphite and its relationship to the oxygen concentration through surface sensitive experiments and atomistic simulations. Deposition of lithium on graphite yielded 5%–8% oxygen surface concentration and when subsequently irradiated with D ions at energies between 500 and 1000?eV/amu and fluences over 1016?cm-2 the oxygen concentration rose to between 25% and 40%. These enhanced oxygen levels were reached in a few seconds compared to about 300?h when the lithiated graphite was allowed to adsorb oxygen from the ambient environment under equilibrium conditions. Irradiating graphite without lithium deposition, however, resulted in complete removal of oxygen to levels below the detection limit of XPS (e.g., <1%). These findings confirm the predictions of atomistic simulations, which had concluded that oxygen was the primary component for the enhanced hydrogen retention chemistry on the lithiated graphite surface.

C.N. Taylor; J. Dadras; K.E. Luitjohan; J.P. Allain; P.S. Krstic; C.H. Skinner

2013-12-01T23:59:59.000Z

230

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

E-Print Network [OSTI]

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

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

2001-01-01T23:59:59.000Z

231

Reuse of steel and aluminium without melting  

E-Print Network [OSTI]

-of-life metal components that could be reused for each product, the catalogue formed the basis of a set of semi-structured interviews with industrial experts. The results suggest that approximately 30% of steel and aluminium used in current products could... Allwood J.M., Cullen J.M., Cooper D.R., Milford R.L., Patel A.C.H., Carruth M.A., McBrien M., 2010. Conserving our metal energy: avoiding melting steel and aluminium scrap to save energy and carbon. University of Cambridge, ISBN 978-0-903428-30-9 Allwood...

Cooper, Daniel

2014-01-07T23:59:59.000Z

232

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

SciTech Connect (OSTI)

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

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

2013-12-15T23:59:59.000Z

233

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

234

Electron beam skull melting and refining of secondary copper  

SciTech Connect (OSTI)

Electron Beam Melting is the most efficient technology for metals and alloys refining. For secondary metals processing the Electron Beam Skull Melting (EBSM) with the electromagnetic stirring (EMS) of melt in the crucible was shown to be the most appropriate. The copper produced by EBSM with EMS possesses higher density and electric conductivity in comparison with other refining methods. The details for high power electrical machines were cast of the copper waste refined by EBSM technology.

Bychkov, Y.; Ladokhin, S. [Donetskvtortsvetmet, Donetsk (Ukraine)

1995-12-31T23:59:59.000Z

235

Electron beam melting state-of-the-art 1984  

SciTech Connect (OSTI)

In 1984 electron beam melting and refining appear poised for an important new growth phase. The driving force for this phase is improved production economics made possible by technological advances. There is also a new and exciting growth application for electron beam melting: its use for surface properties beneficiation. This article is based in part on the content of the Conference on Electron Beam Melting and Refining, The State-of-the-Art 1983, held in November 1983 in Reno, Nevada.

Bakish, R.

1984-06-01T23:59:59.000Z

236

Retrograde Melting and Internal Liquid Gettering in Silicon  

SciTech Connect (OSTI)

Retrograde melting (melting upon cooling) is observed in silicon doped with 3d transition metals, via synchrotron-based temperature-dependent X-ray microprobe measurements. Liquid metal-silicon droplets formed via retrograde melting act as efficient sinks for metal impurities dissolved within the silicon matrix. Cooling results in decomposition of the homogeneous liquid phase into solid multiple-metal alloy precipitates. These phenomena represent a novel pathway for engineering impurities in semiconductor-based systems.

Hudelson, Steve; Newman, Bonna K.; Bernardis, Sarah; Fenning, David P.; Bertoni, Mariana I.; Marcus, Matthew A.; Fakra, Sirine C.; Lai, Barry; Buonassisi, Tonio

2011-07-01T23:59:59.000Z

237

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

238

Plasma arc melting of titanium-tantalum alloys  

SciTech Connect (OSTI)

Los Alamos has several applications for high temperature, oxidation and liquid-metal corrosion resistant materials. Further, materials property constraints are dictated by a requirement to maintain low density; e.g., less than the density of stainless steel. Liquid metal compatibility and density requirements have driven the research toward the Ti-Ta system with an upper bound of 60 wt% Ta-40 wt% Ti. Initial melting of these materials was performed in a small button arc melter with several hundred grams of material; however, ingot quantities were soon needed. But, refractory metal alloys whose constituents possess very dissimilar densities, melting temperatures and vapor pressures pose significant difficulty and require specialized melting practices. The Ti-Ta alloys fall into this category with the density of tantalum 16.5 g/cc and that of titanium 4.5 g/cc. Melting is further complicated by the high melting point of Ta(3020 C) and the relatively low boiling point of Ti(3287 C). Previous electron beam melting experience with these materials resulted, in extensive vaporization of the titanium and poor chemical homogeneity. Vacuum arc remelting(VAR) was considered as a melting candidate and discarded due to density and vapor pressure issues associated with electron beam. Plasma arc melting offered the ability to supply a cover gas to deal with vapor pressure issues as well as solidification control to help with macrosegregation in the melt and has successfully produced high quality ingots of the Ti-Ta alloys.

Dunn, P.; Patterson, R.A. [Los Alamos National Lab., NM (United States); Haun, R. [Retech, Inc., Ukiah, CA (United States)

1994-08-01T23:59:59.000Z

239

Atomistic Study of the Melting Behavior of Single Crystalline...  

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

and 110-oriented lateral facets, respectively. Citation: Wang Z, X Zu, F Gao, and WJ Weber.2007."Atomistic Study of the Melting Behavior of Single Crystalline Wurtzite Gallium...

240

Melt zones beneath five volcanic complexes in California: an...  

Open Energy Info (EERE)

melt zones. 23 figs. Authors Goldstein, N. E.; Flexser and S. Published DOE Information Bridge, 1211984 DOI Not Provided Check for DOI availability: http:crossref.org...

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

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

SciTech Connect (OSTI)

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

Fox, K.; Marra, J.

2011-01-19T23:59:59.000Z

242

Capacitance of edge plane of pyrolytic graphite in acetonitrile solutions  

SciTech Connect (OSTI)

The capacitance of the edge plane of pyrolytic graphite electrodes, in acetonitrile solutions, is measured by recording the current response to an applied triangular voltage sweep; TVS, and then fitting the current response with an appropriate function, (via a set of adjustable parameters). The pretreatment of the electrodes, the supporting electrolyte concentration used, and the frequency of the input TVS, were all found to affect the measured capacitance. In these experiments, a background current was also seen and the shape of the current output for the TVS; the charging/discharging curve, is shown to correlate with the magnitude of this background current. In addition, the size of the background current was found to have some dependence on the type of electrode pretreatment procedure used. 60 refs., 49 figs., 3 tabs.

Minick, S.K.; Ishida, Takanobu

1991-05-01T23:59:59.000Z

243

Meals included in Conference Registrations  

E-Print Network [OSTI]

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

Arnold, Jonathan

244

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

DOE Patents [OSTI]

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

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

2014-04-08T23:59:59.000Z

245

Oxidation of PCEA nuclear graphite by low water concentrations in helium  

SciTech Connect (OSTI)

Accelerated oxidation tests were performed to determine kinetic parameters of the chronic oxidation reaction of PCEA graphite in contact with helium coolant containing low moisture concentrations in high temperature gas-cooled reactors. To the authors best knowledge such a study has not been done since the detailed analysis of reaction of H-451 graphite with steam [Velasquez, Hightower, Burnette, 1978]. Since that H-451 graphite is now unavailable, it is urgently needed to characterize chronic oxidation behavior of new graphite grades under qualification for gas-cooled reactors. The Langmuir-Hinshelwood mechanism of carbon oxidation by water results in a non-linear reaction rate expression, with at least six different parameters. They were determined in accelerated oxidation experiments that covered a large range of temperatures (800 to 1100 oC), and partial pressures of water (15 to 850 Pa) and hydrogen (30 to 150 Pa) and used graphite specimens thin enough (4 mm) in order to avoid diffusion effects. Data analysis employed a statistical method based on multiple likelihood estimation of parameters and simultaneous fitting of non-linear equations. The results show significant material-specific differences between graphite grades PCEA and H-451 which were attributed to microstructural dissimilarity of the two materials. It is concluded that kinetic data cannot be transferred from one graphite grade to another.

Contescu, Cristian I [ORNL; Mee, Robert [University of Tennessee (UT); Wang, Peng [ORNL; Romanova, Anna V [University of Tennessee, Knoxville (UTK); Burchell, Timothy D [ORNL

2014-01-01T23:59:59.000Z

246

Redox reaction and foaming in nuclear waste glass melting  

SciTech Connect (OSTI)

This document was prepared by Pacific Northwest Laboratory (PNL) and is an attempt to analyze and estimate the effects of feed composition variables and reducing agent variables on the expected chemistry of reactions occurring in the cold cap and in the glass melt in the nuclear waste glass Slurry-fed, joule-heated melters as they might affect foaming during the glass-making process. Numerous redox reactions of waste glass components and potential feed additives, and the effects of other feed variables on these reactions are reviewed with regard to their potential effect on glass foaming. A major emphasis of this report is to examine the potential positive or negative aspects of adjusting feed with formic acid as opposed to other feed modification techniques including but not limited to use of other reducing agents. Feed modification techniques other than the use of reductants that should influence foaming behavior include control of glass melter feed pH through use of nitric acid. They also include partial replacement of sodium salts by lithium salts. This latter action (b) apparently lowers glass viscosity and raises surface tension. This replacement should decrease foaming by decreasing foam stability.

Ryan, J.L.

1995-08-01T23:59:59.000Z

247

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

248

Low-melting point heat transfer fluid  

DOE Patents [OSTI]

A low-melting point, heat transfer fluid comprising a mixture of LiNO.sub.3, NaNO.sub.3, KNO.sub.3, NaNO.sub.2 and KNO.sub.2 salts where the Li, Na and K cations are present in amounts of about 20-33.5 mol % Li, about 18.6-40 mol % Na, and about 40-50.3 mol % K and where the nitrate and nitrite anions are present in amounts of about 36-50 mol % NO.sub.3, and about 50-62.5 mol % NO.sub.2. These compositions can have liquidus temperatures between 70.degree. C. and 80.degree. C. for some compositions.

Cordaro, Joseph G. (Oakland, CA); Bradshaw, Robert W. (Livermore, CA)

2011-04-12T23:59:59.000Z

249

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

SciTech Connect (OSTI)

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

Eto, M.; Growcock, F.B.

1981-09-01T23:59:59.000Z

250

Electron-beam scull melting with electromagnetic stirring of melt in crucible  

SciTech Connect (OSTI)

The technologies and equipment have been developed for electron-beam scull melting with electromagnetic stirring of melt for some Ni-based superalloys as well as for multi-component Ti-, Zr-, Nb-, and Mo-based alloys. Two types of scull crucible sets with electromagnetic stirring systems have been constructed, with the metal pouring by the crucible tilting or through the hole in the crucible bottom. In the second case slag does not fall into a mold, and the electron beam may be used for metal heating in the costing head, thus improving the quality of castings. The technologies developed allow to utilize scrap, cost part reverts, chips etc. thus saving virgin alloys. The electromagnetic stirring application permits to product multi-component alloys, to increase the mass of the metal poured, and to reduce the specific energy expenditure and metal loss through evaporation.

Ladokhin, S.V. [Institute for Casting Problems, Kiev (Ukraine)

1994-12-31T23:59:59.000Z

251

Vitrification of waste with conitnuous filling and sequential melting  

DOE Patents [OSTI]

A method of filling a canister with vitrified waste starting with a waste, such as high-level radioactive waste, that is cooler than its melting point. Waste is added incrementally to a canister forming a column of waste capable of being separated into an upper zone and a lower zone. The minimum height of the column is defined such that the waste in the lower zone can be dried and melted while maintaining the waste in the upper zone below its melting point. The maximum height of the column is such that the upper zone remains porous enough to permit evolved gases from the lower zone to flow through the upper zone and out of the canister. Heat is applied to the waste in the lower zone to first dry then to raise and maintain its temperature to a target temperature above the melting point of the waste. Then the heat is applied to a new lower zone above the melted waste and the process of adding, drying and melting the waste continues upward in the canister until the entire canister is filled and the entire contents are melted and maintained at the target temperature for the desired period. Cooling of the melted waste takes place incrementally from the bottom of the canister to the top, or across the entire canister surface area, forming a vitrified product.

Powell, James R. (Shoreham, NY); Reich, Morris (Kew Gardens Hills, NY)

2001-09-04T23:59:59.000Z

252

Standard Reference Material 1751: Gallium Melting-Point Standard  

E-Print Network [OSTI]

Standard Reference Material 1751: Gallium Melting-Point Standard Gregory F. Strouse NIST Special Publication 260-157 #12;#12;NIST Special Publication 260-157 XXXX Standard Reference Material 1751: Gallium Melting-Point Standard Gregory F. Strouse Chemical Science and Technology Laboratory Process Measurements

253

Electron beam melting and casting of zirconium and titanium alloys  

SciTech Connect (OSTI)

The results of electron beam melting (EBM) and casting Zirconium and Titanium alloys are discussed. The data on different schedules used for EBM of this metals as well as equipment for crucible melting and special equipment for casting are described. The results of production of Zirconium and Titanium alloy mold castings for various purposes are presented.

Arzhakova, V.M.; Popov, E.I. [A.A. Bochvar All Union Scientific and Research Institute of Inorganic Materials, Moscow (Russian Federation); Dubrovski, V.A.; Frolov, V.I. [PO ChMZ, Glazov (Russian Federation); Ladohin, S.V.; Levitsky, N.I.; Chernyavsky, V.B. [Scientific and Research Institute of Casting, Kiev (Ukraine)

1994-12-31T23:59:59.000Z

254

Electron beam melting and refining state of the art 1995  

SciTech Connect (OSTI)

This is the proceedings of the Electron Beam Melting and Refining - State of the Art 1995 Conference. It contains 23 of the 30 scheduled papers. Papers cover an array of electron beam melting applications, from industrial plating of metal strip, through government work on manufacturing and processing fissile alloys. Separate abstracts have been prepared for articles from this proceedings.

Bakish, R. [ed.

1995-12-31T23:59:59.000Z

255

ARTICLE IN PRESS Kinetics of convective crystal dissolution and melting,  

E-Print Network [OSTI]

Department of Geological Sciences, The University of Michigan, Ann Arbor, MI 48109-1063, USA5 Received 25 instability (similar to melting of ice) with or 14 without water (although presence of warm water may increase the dissociation rate). Dissociation of methane hydrate 15 into gas and water is similar to ice melting

Zhang, Youxue

256

An analysis of variations in isentropic melt productivity  

E-Print Network [OSTI]

An analysis of variations in isentropic melt productivity B y P. D. Asimow1 , M. M. Hirschmann1 productivity, cannot be determined directly from experiments and is commonly assumed to be constant on a ther- modynamic model of peridotite partial melting, we show that productivity for re- versible

Asimow, Paul D.

257

Detection of Nonthermal Melting by Ultrafast X-ray  

E-Print Network [OSTI]

of super- heating of the interface but limited by the speed of sound. Typically, a layer a few tens, if a solid is heated to or above the melting temperature, nucleation of the liquid phase occurs around), which exceeds the melting temperature within several picoseconds. After nucleation of the liquid phase

Geddes, Cameron Guy Robinson

258

Vitrification of surrogate mixed wastes in a graphite electrode arc melter  

SciTech Connect (OSTI)

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

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

1995-11-01T23:59:59.000Z

259

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

E-Print Network [OSTI]

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

Zhang, Guangyu

260

Electrochromic polyaniline/graphite oxide nanocomposites with endured electrochemical energy storage  

E-Print Network [OSTI]

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

Guo, John Zhanhu

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

E-Print Network [OSTI]

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

Svenson, Ernest Knute

2014-01-01T23:59:59.000Z

262

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.

263

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

SciTech Connect (OSTI)

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

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

2010-01-01T23:59:59.000Z

264

Wetting transition behavior of Xe on Cs and Cs/graphite Stefano Curtarolo,1,  

E-Print Network [OSTI]

Wetting transition behavior of Xe on Cs and Cs/graphite Stefano Curtarolo,1, * Milton W. Cole,2 surface, covered by a monolayer of Cs. With data obtained from grand canonical Monte Carlo simulations

Curtarolo, Stefano

265

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

Office of Scientific and Technical Information (OSTI)

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

266

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

267

Sponsorship includes: Agriculture in the  

E-Print Network [OSTI]

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

Nebraska-Lincoln, University of

268

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

SciTech Connect (OSTI)

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

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

2008-03-01T23:59:59.000Z

269

Effect of graphite properties in thermal analysis of CHTR: A parametric study  

SciTech Connect (OSTI)

Compact High Temperature Reactor (CHTR) is a {sup 233}U-Thorium fuelled, lead-bismuth cooled reactor. The CHTR core mainly consists of graphite and beryllium oxide (BeO). The CHTR core consists of nineteen prismatic beryllium oxide (BeO) moderator blocks. These 19 blocks contain centrally located graphite fuel tubes. The BeO moderator blocks are surrounded by reflector blocks (partially graphite and partially BeO). The nuclear heat from the core is removed passively by natural circulation of the coolant between top and bottom plenums, upward through the fuel tubes and returning through the downcomer tubes at the periphery. The temperature gradient in fuel tubes, downcomer tubes and BeO is very high and therefore, to take care of the differential thermal expansion, gaps are provided in the core between the tubes and other core components. These gaps affect the heat transfer through the core in radial direction. In addition, there is a large variation in thermal properties of graphite which in turn affects the thermal behaviour of the core in various operating conditions. The fuel of CHTR is TRISO coated particle fuel. These particles are packed in with graphite powder as matrix and made into cylindrical compacts these compacts are packed in the bores of fuel tube. In this study, the effect of the thermal conductivity variation of the graphite on the temperature distribution of the core and density variation of the matrix graphite material in fuel compact on the maximum fuel kernel temperature is studied along with the overall role of graphite properties variation in heat transfer.

Kaushik, Ankur; Basak, Abhishek; Dulera, I. V.; Vijayan, P. K. [Reactor Engineering Division, Bhabha Atomic Research Centre, Mumbai-400 085 (India)

2013-06-12T23:59:59.000Z

270

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

E-Print Network [OSTI]

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

Howell, Huston Edward

1980-01-01T23:59:59.000Z

271

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

E-Print Network [OSTI]

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

Cohen, Ronald Nelson

1982-01-01T23:59:59.000Z

272

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

E-Print Network [OSTI]

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

Harper, Brian Douglas

2012-06-07T23:59:59.000Z

273

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

E-Print Network [OSTI]

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

van Saarloos, Wim

274

Assessment of ceramic coatings for metal fuel melting crucible  

SciTech Connect (OSTI)

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

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

2013-07-01T23:59:59.000Z

275

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

SciTech Connect (OSTI)

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

Rich Johnson; Yu-Hsin Tung; Hiroyuki Sato

2011-07-01T23:59:59.000Z

276

Graphite electrode arc melter demonstration Phase 2 test results  

SciTech Connect (OSTI)

Several U.S. Department of Energy organizations and the U.S. Bureau of Mines have been collaboratively conducting mixed waste treatment process demonstration testing on the near full-scale graphite electrode submerged arc melter system at the Bureau`s Albany (Oregon) Research Center. An initial test series successfully demonstrated arc melter capability for treating surrogate incinerator ash of buried mixed wastes with soil. The conceptual treatment process for that test series assumed that buried waste would be retrieved and incinerated, and that the incinerator ash would be vitrified in an arc melter. This report presents results from a recently completed second series of tests, undertaken to determine the ability of the arc melter system to stably process a wide range of {open_quotes}as-received{close_quotes} heterogeneous solid mixed wastes containing high levels of organics, representative of the wastes buried and stored at the Idaho National Engineering Laboratory (INEL). The Phase 2 demonstration test results indicate that an arc melter system is capable of directly processing these wastes and could enable elimination of an up-front incineration step in the conceptual treatment process.

Soelberg, N.R.; Chambers, A.G.; Anderson, G.L.; O`Connor, W.K.; Oden, L.L.; Turner, P.C.

1996-06-01T23:59:59.000Z

277

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

Broader source: Energy.gov [DOE]

Recovery Act funds help clean up the Hanford site, retrograde melting (melting as something cools) and how open-cell clouds could help predict climate change.

278

Energy Efficient Glass Melting - The Next Generation Melter  

SciTech Connect (OSTI)

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

David Rue

2008-03-01T23:59:59.000Z

279

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

280

Method For Synthesizing Extremely High-Temperature Melting Materials  

DOE Patents [OSTI]

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

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

2005-11-22T23:59:59.000Z

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

Method for synthesizing extremely high-temperature melting materials  

SciTech Connect (OSTI)

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

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

2007-11-06T23:59:59.000Z

282

Evolution of Shear-Induced Melting in a Dusty Plasma Yan Feng,* J. Goree, and Bin Liu  

E-Print Network [OSTI]

is reached. Melting spreads with a front that propagates at the transverse sound speed. Unexpectedly essentially on a 2D plane include a Wigner lattice of electrons on a liquid-He surface [8], ions confined to a crystalline solid or a liquid [17]. Coulomb repulsion is shielded with a screening length D [27]. Dusty

Goree, John

283

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

284

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 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

285

Proceedings of the conference on electron beam melting and refining - state of the art 1994  

SciTech Connect (OSTI)

The volume: Proceedings of the Conference on Electron Beam Melting and Refining-State of the Art 1994 covers many aspects of electron beam production, process control, components, and applications. Included were several papers from the defunct Soviet Bloc nations concerning the specifications and uses for their electron beam furnaces. Main topics of the conference were: Electron Beam (EB) Equipment; Safety and Analytical Aspects related to EB Melting; Material Processing with EB; Other Applications for EB; and A Look at EB in the East. EB has many uses, several papers mentioned the recycling of uranium scrap, the casting of heat resistant or corrosion resistant alloys, or the improved microstructure of alloys with the technique.

Bakish, R. [ed.

1994-12-31T23:59:59.000Z

286

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

E-Print Network [OSTI]

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

Trieu Mai

2006-01-31T23:59:59.000Z

287

Melt-castable energetic compounds comprising oxadiazoles and methods of production thereof  

DOE Patents [OSTI]

In one embodiment, a melt-castable energetic material comprises at least one of: 3,5-bis(4-nitro-1,2,5-oxadiazol-3-yl)-1,2,4-oxadiazole (DNFO), and 3-(4-amino-1,2,5-oxadiazol-3-yl)-5-(4-nitro-1,2,5-oxadiazol-3-yl)-1,2- ,4-oxadiazole (ANFO). In another embodiment, a method for forming a melt-castable energetic material includes reacting 3,5-bis(4-amino-1,2,5-oxadiazol-3-yl)-1,2,4-oxadiazole (DAFO) with oxygen or an oxygen-containing compound to form a mixture of at least: DNFO, and ANFO.

Pagoria, Philip F; Zhang, Mao X

2013-11-12T23:59:59.000Z

288

Characterization of Porosity Development in Oxidized Graphite using Automated Image Analysis Techniques  

SciTech Connect (OSTI)

This document reports on initial activities at ORNL aimed at quantitative characterization of porosity development in oxidized graphite specimens using automated image analysis (AIA) techniques. A series of cylindrical shape specimens were machined from nuclear-grade graphite (type PCEA, from GrafTech International). The specimens were oxidized in air to various levels of weight loss (between 5 and 20 %) and at three oxidation temperatures (between 600 and 750 oC). The procedure used for specimen preparation and oxidation was based on ASTM D-7542-09. Oxidized specimens were sectioned, resin-mounted and polished for optical microscopy examination. Mosaic pictures of rectangular stripes (25 mm x 0.4 mm) along a diameter of sectioned specimens were recorded. A commercial software (ImagePro) was evaluated for automated analysis of images. Because oxidized zones in graphite are less reflective in visible light than the pristine, unoxidized material, the microstructural changes induced by oxidation can easily be identified and analyzed. Oxidation at low temperatures contributes to development of numerous fine pores (< 100 m2) distributed more or less uniformly over a certain depth (5-6 mm) from the surface of graphite specimens, while causing no apparent external damage to the specimens. In contrast, oxidation at high temperatures causes dimensional changes and substantial surface damage within a narrow band (< 1 mm) near the exposed graphite surface, but leaves the interior of specimens with little or no changes in the pore structure. Based on these results it appears that weakening and degradation of mechanical properties of graphite materials produced by uniform oxidation at low temperatures is related to the massive development of fine pores in the oxidized zone. It was demonstrated that optical microscopy enhanced by AIA techniques allows accurate determination of oxidant penetration depth and of distribution of porosity in oxidized graphite materials.

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

2009-09-01T23:59:59.000Z

289

Variational bounds for the shear viscosity of gelling melts  

E-Print Network [OSTI]

We study shear stress relaxation for a gelling melt of randomly crosslinked, interacting monomers. We derive a lower bound for the static shear viscosity $\\eta$, which implies that it diverges algebraically with a critical exponent $k\\ge 2\

Claas H. Köhler; Henning Löwe; Peter Müller; Annette Zippelius

2007-05-03T23:59:59.000Z

290

Melt extrusion and continuous manufacturing of pharmaceutical materials  

E-Print Network [OSTI]

Melt extrusion is an alternative processing technique that operates continuously, reduces the total number of unit operations, allows for incorporation of difficult-to-process drug substances, and has the potential to ...

Bell, Erin R

2011-01-01T23:59:59.000Z

291

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

292

Precambrian coal or anthraxolite: A source for graphite in high-grade schists and gneisses-a reply  

SciTech Connect (OSTI)

Argues that without considering data for igneous carbon (carbonatites) or for ultrahigh metamorphic calcareous gneisses such as are found in the Grenville province of North America, the conclusion that the source of carbon for vein graphite is magmatic or carbonate carbon is not justified. Points out that marbles and calc-silicate gneisses occur with the graphite-bearing granulite facies rocks in Sri Lanka. Calcite may also be seen in the veins with the graphite. Concludes that whether the graphite in epigenetic veins in high grade schists and gneisses has variable carbon isotope ratios depends on whether it was derived from organic material in carbonate or noncarbonate metasediments.

Mancuso, J.J.; Seavoy, R.E.

1982-08-01T23:59:59.000Z

293

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

DOE Patents [OSTI]

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

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

2014-05-20T23:59:59.000Z

294

Low-temperature, site selective graphitization of SiC via ion implantation and pulsed laser annealing  

SciTech Connect (OSTI)

A technique is presented to selectively graphitize regions of SiC by ion implantation and pulsed laser annealing (PLA). Nanoscale features are patterned over large areas by multi-ion beam lithography and subsequently converted to few-layer graphene via PLA in air. Graphitization occurs only where ions have been implanted and without elevating the temperature of the surrounding substrate. Samples were characterized using Raman spectroscopy, ion scattering/channeling, SEM, and AFM, from which the degree of graphitization was determined to vary with implantation species, damage and dose, laser fluence, and pulsing. Contrasting growth regimes and graphitization mechanisms during PLA are discussed.

Lemaitre, Maxime G. [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32601 (United States); Tongay, Sefaattin [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32601 (United States); Department of Physics, University of Florida, Gainesville, Florida 32601 (United States); Department of Materials Science and Engineering, University of California, Berkeley, California 94720 (United States); Nanoscience Institute for Medical and Engineering Technology, University of Florida, Gainesville, Florida 32601 (United States); Wang, Xiaotie [Department of Chemical Engineering, University of Florida, Gainesville, Florida 32601 (United States); Venkatachalam, Dinesh K.; Elliman, Robert G. [Department of Electronic Materials Engineering, Australian National University, Canberra, ACT 0200 (Australia); Fridmann, Joel [Nanoscience Institute for Medical and Engineering Technology, University of Florida, Gainesville, Florida 32601 (United States); Raith USA, Incorporated, Ronkonkoma, New York 11779 (United States); Gila, Brent P.; Appleton, Bill R. [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32601 (United States); Nanoscience Institute for Medical and Engineering Technology, University of Florida, Gainesville, Florida 32601 (United States); Hebard, Arthur F. [Department of Physics, University of Florida, Gainesville, Florida 32601 (United States); Ren, Fan [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32601 (United States); Department of Chemical Engineering, University of Florida, Gainesville, Florida 32601 (United States)

2012-05-07T23:59:59.000Z

295

Characterization of electron beam melted uranium - 6% niobium ingots  

SciTech Connect (OSTI)

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

McKoon, R.H.

1997-10-31T23:59:59.000Z

296

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

297

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

298

Velocity of sound in solid methane near melting temperatures  

E-Print Network [OSTI]

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

Whitehead, John Martin

1968-01-01T23:59:59.000Z

299

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

SciTech Connect (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

300

Improving interface through surface modification by plasma polymerization, in carbon/graphite fiber reinforced polymeric composites  

SciTech Connect (OSTI)

Carbon/graphite fiber surfaces were modified by plasma polymerization. An inductively coupled electrodeless glow-discharge system was utilized to treat the surfaces with acrylonitrile or styrene at the established operating conditions. Critical surface erosion for wetting measured by the sessile drop method, of plasma treated pyrolytic graphite blocks, used as a model surface for carbon/graphite fibers, were lower than of untreated block. Contact angles on plasma polymers deposited on different substrates had similar values. Contact angle, measured by Wilhelmy balance method of water, on untreated Fortafil 3 carbon/graphite fiber was 55.1/sup 0/, whereas the commercially treated one was 43.7/sup 0/. Plasma treatments reduced the contact angle to 44.3/sup 0/ in An and 47.3/sup 0/ in styrene monomer cases. Thicknesses of plasma polymers deposited under the established optimum conditions, measured by ellipsometer, were 840 A for PPAN and 2192 A for PPST after one hour treatment. In conclusion, plasma treatments of carbon/graphite fibers are an effective alternative to existing methods for improving interfacial shear strengths and maintaining or improving the tensile strengths of the fibers.

Dagli, N.G.

1986-01-01T23:59:59.000Z

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.


301

Melt segregation under compaction and shear channelling: Application to granitic magma segregation in a continental crust  

E-Print Network [OSTI]

1 Melt segregation under compaction and shear channelling: Application to granitic magma segregation in a mush submitted to both compaction and shear. It applies to a granitic melt imbedded within of melt to about 20 % in total to be extracted from the matrix. Abridged title Granitic melt segregation

Paris-Sud XI, Université de

302

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

E-Print Network [OSTI]

Spatial and Temporal Transferability of a Distributed Energy-Balance Glacier Melt Model ANDREW H model transferability, a distributed energy-balance melt model (DEBM) is applied to two small glaciers- face energy balance, and empirically based melt models, which correlate melt with temperature

Flowers, Gwenn

303

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

SciTech Connect (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

304

Dynamics of crystallization from segregated block copolymer melts  

SciTech Connect (OSTI)

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

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

1996-12-31T23:59:59.000Z

305

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

SciTech Connect (OSTI)

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

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

2014-03-03T23:59:59.000Z

306

Electrochemical and structural characterization of ordered graphite electrodes  

SciTech Connect (OSTI)

Highly oriented pyrolytic graphite (HOPG) was utilized to examine the structure/reactivity relationships for carbon electrodes in a well-defined matter. The basal plane of HOPG is ideal for this type of study due to its well-ordered surface structure. The electrochemical reactivity of basal plane HOPG was determined in terms of adsorption of anthraquinone 2,6-desulfonate ([Gamma][sub 2,6-AQDS]), the heterogeneous electron transfer rate constant of the ferro/ferricyanide redox couple (k[degrees] for Fe(CN)[sup [minus]3/[minus]4][sub 6]) and electrode capacitance (C[degrees]). [Gamma][sub 2,6-AQDS] tracks defects at basal plane HOPG electrodes indicating that the adsorption of 2,6-AQDS is a good marker for defects on the surface of basal plane HOPG. When measured on the same basal plane surface, k[degrees] for Fe(CN)[sup [minus]3/[minus]4][sub 6] and C[degrees] correlate with [Gamma][sub 2,6-AQDS] indicating that all three electrochemical observables are controlled by the same surface variables. This illustrates the importance of surface defects on electrochemical activity at basal plane HOPG electrodes. The correlation between k[degrees] for Fe(CN)[sup [minus]3/[minus]4][sub 6], C[degrees] and [Gamma][sub 2,6-AQDS] enabled the evaluation of these parameters at near-perfect basal plane. The data indicate that basal plane HOPG exhibits anomalously low electrochemical reactivity. An investigation of basal plane HOPG electrodes with scanning tunneling microscopy (STM) revealed that defects, in the form of cleavage steps, cover 1% of the surface for the HOPG sample studied. Atomic scale STM images of step edges revealed that structural defects induce an electronic perturbation of the surface which occupies a significant area near the defect. [Gamma][sub 2,6-AQDS], k[degrees] for Fe(CN)[sup [minus]3/[minus]4][sub 6] and C[degrees] are influenced not only by the structural defect but also by the defect induced electronic perturbation.

McDermott, M.T.

1993-01-01T23:59:59.000Z

307

Energy Saving Melting and Revert Reduction Technology (Energy-SMARRT): Clean Steel Casting Production  

SciTech Connect (OSTI)

Inclusions in steel castings can cause rework, scrap, poor machining, and reduced casting performance, which can obviously result in excess energy consumption. Significant progress in understanding inclusion source, formation and control has been made. Inclusions can be defined as non-metallic materials such as refractory, sand, slag, or coatings, embedded in a metallic matrix. This research project has focused on the mold filling aspects to examine the effects of pouring methods and gating designs on the steel casting cleanliness through water modeling, computer modeling, and melting/casting experiments. Early in the research project, comprehensive studies of bottom-pouring water modeling and low-alloy steel casting experiments were completed. The extent of air entrainment in bottom-poured large castings was demonstrated by water modeling. Current gating systems are designed to prevent air aspiration. However, air entrainment is equally harmful and no prevention measures are in current practice. In this study, new basin designs included a basin dam, submerged nozzle, and nozzle extension. The entrained air and inclusions from the gating system were significantly reduced using the new basin method. Near the end of the project, there has been close collaboration with Wescast Industries Inc., a company manufacturing automotive exhaust components. Both computer modeling using Magma software and melting/casting experiments on thin wall turbo-housing stainless steel castings were completed in this short period of time. Six gating designs were created, including the current gating on the pattern, non-pressurized, partially pressurized, naturally pressurized, naturally pressurized without filter, and radial choke gating without filter, for Magma modeling. The melt filling velocity and temperature were determined from the modeling. Based on the simulation results, three gating designs were chosen for further melting and casting experiments on the same casting pattern using the lip pouring method. It was observed again that gating designs greatly influenced the melt filling velocity and the number of inclusion defects. The radial choked gating showed improvements in casting cleanliness and yield over the other gatings, even though no mold filters were used in the gating system.

Kuyucak, Selcuk [CanmetMATERIALS; Li, Delin [CanmetMATERIALS

2013-12-31T23:59:59.000Z

308

Scattering of 64 eV to 3 keV Neutrons from Polyethylene and Graphite and the Coherence Length Problem  

E-Print Network [OSTI]

Scattering of 64 eV to 3 keV Neutrons from Polyethylene and Graphite and the Coherence Length intensity ratios from polyethylene (CH2) relative to graphite (C) at several discrete final energies

Danon, Yaron

309

STUDY OF GRAPHITE TARGETS INTERACTING WITH THE 24 GeV PROTON BEAM OF THE BNL MUON TARGET EXPERIMENT*  

E-Print Network [OSTI]

experiment, graphite and carbon-carbon composite targets were exposed to the AGS beam and their response materials for the future muon collider/neutrino factory carbon-based solid targets have been considered for the experiment are ATJ graphite and the anisotropic carbon-carbon composite. Each target consists of a pair of 16

McDonald, Kirk

310

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

E-Print Network [OSTI]

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

Cao, Guozhong

311

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

E-Print Network [OSTI]

A New Method for Quantitative Marking of Deposited Lithium via Chemical Treatment on Graphite*[e] and Thomas Schleid[f] Abstract: A novel approach for the marking of deposited lithium on graphite anodes from of the electrochemical stability window of the electrolyte components.[3] Therefore, changes on the electrode

Schmidt, Volker

312

Latex and two-roll mill processing of thermally-exfoliated graphite oxide/natural rubber nanocomposites  

E-Print Network [OSTI]

Latex and two-roll mill processing of thermally-exfoliated graphite oxide/natural rubber t Thermally-exfoliated graphite oxide (TEGO) is a graphene-based material that has been previously shown to graphene-based materials [4]. GO can be exfoliated in water into single-layer graphene oxide platelets

313

A Simplified Electrochemical and Thermal Aging Model of LiFePO4-Graphite Li-ion Batteries  

E-Print Network [OSTI]

1 A Simplified Electrochemical and Thermal Aging Model of LiFePO4-Graphite Li-ion Batteries: Power of a commercial LiFePO4-graphite Li-ion battery. Compared to the isothermal reference, the mechanism of porosity;2 Due to their high power and energy densities, Li-ion technologies are the leading battery systems

314

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

E-Print Network [OSTI]

Simplified Electrochemical and Thermal Model of LiFePO4- Graphite Li-Ion Batteries for Fast Charge, a simplified electrochemical and thermal model of LiFePO4-graphite based Li-ion batteries is developed : 10.1149/2.064209jes #12;Over the past 15 years, Li-ion batteries have received much attention

Paris-Sud XI, Université de

315

Molecular models for the intercalation of hydrogen molecules into modified graphites  

SciTech Connect (OSTI)

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

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

1995-12-01T23:59:59.000Z

316

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

E-Print Network [OSTI]

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

Arenburg, Robert Thomas

1982-01-01T23:59:59.000Z

317

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

SciTech Connect (OSTI)

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

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

2013-11-18T23:59:59.000Z

318

Laser-processed three dimensional graphitic electrodes for diamond radiation detectors  

SciTech Connect (OSTI)

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

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

2013-07-22T23:59:59.000Z

319

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

E-Print Network [OSTI]

of graphite was found to obey classical Fickian diffusion for short diffusion times. The citations on the following pages follow the style of the Journal Nuclear Technolo I. B The Heed for this Research I. B. l Fission Product Control An important aspect... 1. At temperatures above 800 C, Ag rapidly diffuses in, around, and out the sample. In gas form it moves to the cool ends of the quartz tube and plates out. 110 m 2. It is difficult to diffuse Ag into a graphite sample, particularly if it has...

McMillan, Thad Calhoun

2012-06-07T23:59:59.000Z

320

Validation of the THIRMAL-1 melt-water interaction code  

SciTech Connect (OSTI)

The THIRMAL-1 computer code has been used to calculate nonexplosive LWR melt-water interactions both in-vessel and ex-vessel. To support the application of the code and enhance its acceptability, THIRMAL-1 has been compared with available data from two of the ongoing FARO experiments at Ispra and two of the Corium Coolant Mixing (CCM) experiments performed at Argonne. THIRMAL-1 calculations for the FARO Scoping Test and Quenching Test 2 as well as the CCM-5 and -6 experiments were found to be in excellent agreement with the experiment results. This lends confidence to the modeling that has been incorporated in the code describing melt stream breakup due to the growth of both Kelvin-Helmholtz and large wave instabilities, the sizes of droplets formed, multiphase flow and heat transfer in the mixing zone surrounding and below the melt stream, as well as hydrogen generation due to oxidation of the melt metallic phase. As part of the analysis of the FARO tests, a mechanistic model was developed to calculate the prefragmentation as it may have occurred when melt relocated from the release vessel to the water surface and the model was compared with the relevant data from FARO.

Chu, C.C.; Sienicki, J.J.; Spencer, B.W.

1995-05-01T23:59:59.000Z

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.


321

Device and method for skull-melting depth measurement  

DOE Patents [OSTI]

A method of skull-melting comprises the steps of: a. providing a vessel adapted for a skull-melting process, the vessel having an interior, an underside, and an orifice in connecting the interior and the underside; b. disposing a waveguide in the orifice so that the waveguide protrudes sufficiently into the interior to interact with the skull-melting process; c. providing a signal energy transducer in signal communication with the waveguide; d. introducing into the vessel a molten working material; e. carrying out the skull-melting process so that a solidified skull of the working material is formed, the skull and the vessel having an interface therebetween, the skull becoming fused to the waveguide so the signal energy can be transmitted through the waveguide and the skull without interference from the interface; f. activating the signal energy transducer so that a signal is propagated through the waveguide; and, g. controlling at least one variable of the skull-melting process utilizing feedback information derived from the propagated signal energy.

Lauf, Robert J. (Oak Ridge, TN); Heestand, Richard L. (Oak Ridge, TN)

1993-01-01T23:59:59.000Z

322

Device and method for skull-melting depth measurement  

DOE Patents [OSTI]

A method of skull-melting comprises the steps of: (a) providing a vessel adapted for a skull-melting process, the vessel having an interior, an underside, and an orifice connecting the interior and the underside; (b) disposing a waveguide in the orifice so that the waveguide protrudes sufficiently into the interior to interact with the skull-melting process; (c) providing a signal energy transducer in signal communication with the waveguide; (d) introducing into the vessel a molten working material; (e) carrying out the skull-melting process so that a solidified skull of the working material is formed, the skull and the vessel having an interface therebetween, the skull becoming fused to the waveguide so the signal energy can be transmitted through the waveguide and the skull without interference from the interface; (f) activating the signal energy transducer so that a signal is propagated through the waveguide; and, (g) controlling at least one variable of the skull-melting process utilizing feedback information derived from the propagated signal energy.

Lauf, R.J.; Heestand, R.L.

1993-02-09T23:59:59.000Z

323

07/06/2009 Melting Ice Could Lead to Massive Waves of Climate Refugees Treehugger 06/30/2009 MELTING GREENLAND ICE SHEETS MAY THREATEN  

E-Print Network [OSTI]

/30/2009 MELTING GREENLAND ICE SHEETS MAY THREATEN NORTHEAST U.S., CANADA Federal News Service 06/30/2009 Sea raises spectre of displaced humanity peopleandplanet.net 06/16/2009 Melting Greenland Ice Sheets May Report - Online 06/02/2009 Melting Greenland Ice Sheets May Threaten Northeast, Canada usagnet 06

Hu, Aixue

324

Application of a Barrier Filter at a High Purity Synthetic Graphite Plant, CRADA 99-F035, Final Report  

SciTech Connect (OSTI)

Superior Graphite Company and the US Department of Energy have entered into a Cooperative Research and Development Agreement (CRADA) to study the application of ceramic barrier filters at its Hopkinsville, Kentucky graphite plant. Superior Graphite Company is a worldwide leader in the application of advanced thermal processing technology to produce high purity graphite and carbons. The objective of the CRADA is to determine the technical and economic feasibility of incorporating the use of high-temperature filters to improve the performance of the offgas treatment system. A conceptual design was developed incorporating the ceramic filters into the offgas treatment system to be used for the development of a capital cost estimate and economic feasibility assessment of this technology for improving particulate removal. This CRADA is a joint effort of Superior Graphite Company, Parsons Infrastructure and Technology Group, and the National Energy Technology Laboratory (NETL) of the US Department of Energy (DOE).

National Energy Technology Laboratory

2000-08-31T23:59:59.000Z

325

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

326

Lattice cluster theory for polymer melts with specific interactions  

E-Print Network [OSTI]

Despite the long-recognized fact that chemical structure and specific interactions greatly influence the thermodynamic properties of polymer systems, a predictive molecular theory that enables systematically addressing the role of chemical structure and specific interactions has been slow to develop even for polymer melts. While the lattice cluster theory (LCT) provides a powerful vehicle for understanding the influence of various molecular factors, such as monomer structure, on the thermodynamic properties of polymer melts and blends, the application of the LCT has heretofore been limited to the use of the simplest polymer model in which all united atom groups within the monomers of a species interact with a common monomer averaged van der Waals energy. Thus, the description of a compressible polymer melt involves a single van der Waals energy. As a first step towards developing more realistic descriptions to aid in the analysis of experimental data and the design of new materials, the LCT is extended here to treat models of polymer melts in which the backbone and side groups have different interaction strengths, so three energy parameters are present, namely, backbone-backbone, side group-side group, and backbone-side group interaction energies. Because of the great algebraic complexity of this extension, we retain maximal simplicity within this class of models by further specializing this initial study to models of polymer melts comprising chains with poly($n$-$\\alpha$-olefin) structures where only the end segments on the side chains may have different, specific van der Waals interaction energies with the other united atom groups. An analytical expression for the LCT Helmholtz free energy is derived for the new model. Illustrative calculations are presented to demonstrate the degree to which the thermodynamic properties of polymer melts can be controlled by specific interactions.

Wen-Sheng Xu; Karl F. Freed

2014-07-12T23:59:59.000Z

327

EFFECT OF GLASS-BATCH MAKEUP ON THE MELTING PROCESS  

SciTech Connect (OSTI)

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

328

The effect of pressure upon the melting transition of polyethylene  

E-Print Network [OSTI]

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

Mroz, George Joseph

1961-01-01T23:59:59.000Z

329

Hybrid redox polyether melts based on polyether-tailed counterions  

SciTech Connect (OSTI)

Interesting ionic materials can be transformed into room temperature molten salts by combining them with polyether-tailed counterions such as polyether-tailed 2-sulfobenzoate (MePEG-BzSO{sub 3}{sup {minus}}) and polyethertailed triethylammonium (MePEG-Et{sub 3}N{sup +}). Melts containing ruthenium hexamine, metal trisbipyridines, metal trisphenanthrolines, and ionic forms of aluminum quinolate, anthraquinone, phthalocyanine, and porphyrins are described. These melts exhibit ionic conductivities in the 7 x 10{sup {minus}5} to 7 x 10{sup {minus}10} {Omega}{sup {minus}1} cm{sup {minus}1} range, which permit microelectrode voltammetry in the undiluted materials, examples of which are presented.

Dickinson, E. V; Williams, M.E.; Hendrickson, S.M.; Masui, Hitoshi; Murray, R.W.

1999-02-03T23:59:59.000Z

330

Methods of vitrifying waste with low melting high lithia glass compositions  

DOE Patents [OSTI]

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

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

2001-01-01T23:59:59.000Z

331

Decontamination and decarburization of stainless and carbon steel by melt refining  

SciTech Connect (OSTI)

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

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

1996-09-05T23:59:59.000Z

332

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

SciTech Connect (OSTI)

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

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

1984-01-01T23:59:59.000Z

333

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

SciTech Connect (OSTI)

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

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

1988-10-06T23:59:59.000Z

334

Electropolymerization kinetics of pyrrole in aqueous solution on graphite felt electrodes  

E-Print Network [OSTI]

Electropolymerization kinetics of pyrrole in aqueous solution on graphite felt electrodes I. depends on the synthesis conditions, such as the nature of the solvent, the electro- synthesis method®c properties, the synthesis conditions play a vital role in the performance of the material. In this work, we

Otero, Toribio Fernández

335

Graphite Waste Tank Cleanup and Decontamination under the Marcoule UP1 D and D Program - 13166  

SciTech Connect (OSTI)

The UP1 plant in Marcoule reprocessed nearly 20,000 tons of used natural uranium gas cooled reactor fuel coming from the first generation of civil nuclear reactors in France. During more than 40 years, the decladding operations produced thousands of tons of processed waste, mainly magnesium and graphite fragments. In the absence of a French repository for the graphite waste, the graphite sludge content of the storage pits had to be retrieved and transferred into a newer and safer pit. After an extensive R and D program, the equipment and process necessary for retrieval operations were designed, built and tested. The innovative process is mainly based on the use of two pumps (one to capture and the other one to transfer the sludge) working one after the other and a robotic arm mounted on a telescopic mast. A dedicated process was also set up for the removal of the biggest fragments. The retrieval of the most irradiating fragments was a challenge. Today, the first pit is totally empty and its stainless steel walls have been decontaminated using gels. In the second pit, the sludge retrieval and transfer operations have been almost completed. Most of the non-pumpable graphite fragments has been removed and transferred to a new storage pit. After more than 6 years of operations in sludge retrieval, a lot of experience was acquired from which important 'lessons learned' could be shared. (authors)

Thomasset, Philippe [AREVA D and D BU, Marcoule (France)] [AREVA D and D BU, Marcoule (France); Chabeuf, Jean-Michel [AREVA D and D BU, La Hague (France)] [AREVA D and D BU, La Hague (France); Thiebaut, Valerie [CEA/DEN/DAPD/CPUP, Marcoule (France)] [CEA/DEN/DAPD/CPUP, Marcoule (France); Chambon, Frederic [AREVA FEDERAL SERVICES, Columbia, MD (United States)] [AREVA FEDERAL SERVICES, Columbia, MD (United States)

2013-07-01T23:59:59.000Z

336

THE SYNTHESIS AND CHARACTERIZATION OF GRAPHITE-METAL FLUORIDE INTERCALATION COMPOUNDS  

E-Print Network [OSTI]

inside graphite, except for UF6 which has ~s.1 A. The -6H 0that the lattice energy U(NO+UF6(c)) =- 152 kcal mole- 1 • Asince PtF6 is smaller than UF6, the electron affinity of PtF

McQuillan, Barry William

2014-01-01T23:59:59.000Z

337

Photoexfoliation of Graphene from Graphite: An Ab Initio Study Yoshiyuki Miyamoto,1  

E-Print Network [OSTI]

exfoliation process follows exposure to femtosecond laser pulses with a wavelength of 800 nm and the full and intensity speed up the exfoliation and cause transient contraction in subsurface layers. Photoexfoliation] or chemical [3­7] exfoliation of graphite, or may form by annealing SiC single crystals [8], or by chemical

338

Edge-Enriched Graphitic Anodes by KOH Activation for Higher Rate Capability Lithium Ion Batteries  

E-Print Network [OSTI]

Lithium Ion Batteries D. Zakhidov,1,2 R. Sugamata,3 T. Yasue,3 T. Hayashi,3 Y. A. Kim,3 and M. Endo4 1 successful anode for lithium ion batteries due to its low cost, safety, and ease of fabrication, but higher are expected to surpass conventional graphite anodes due to larger number of edges for lithium ion

339

Development of a Safeguards Approach for a Small Graphite Moderated Reactor and Associated Fuel Cycle Facilities  

E-Print Network [OSTI]

Small graphite-moderated and gas-cooled reactors have been around since the beginning of the atomic age. Though their existence in the past has been associated with nuclear weapons programs, they are capable of being used in civilian power programs...

Rauch, Eric B.

2010-07-14T23:59:59.000Z

340

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

E-Print Network [OSTI]

of micro- and nano-scale RGS. The largest of the RGS are hollow scrolls, with the c-axis predominantly at the micro- and nano-scales. The nano-scale cones tend not to be hollow and may have a cone-helix structureJaszczak et al. 1 MICRO- AND NANO-SCALE GRAPHITE CONES AND TUBES FROM HACKMAN VALLEY, KOLA

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

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

E-Print Network [OSTI]

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

Paris-Sud XI, Université de

342

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

E-Print Network [OSTI]

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

Michel, Robert G.

343

Self-assembly of long chain alkanes and their derivatives on graphite Teng Yang,1  

E-Print Network [OSTI]

, University of New Hampshire, Durham, New Hampshire 03824, USA Received 5 November 2007; accepted 16 January the energetic origin of the domain formation observed in the STM images. Our results for the hierarchy­8 Although many patterns have been reported even for alkane films on graphite, the energetic grounds

344

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

E-Print Network [OSTI]

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

Nordlund, Kai

345

Layering and orientational ordering of propane on graphite: An experimental and simulation study  

E-Print Network [OSTI]

Layering and orientational ordering of propane on graphite: An experimental and simulation study 2002; accepted 30 July 2002 We report the results of an experimental and theoretical study of propane and experiments show that propane adsorbs in a layer-by-layer fashion and exhibits continuous growth beyond

Borguet, Eric

346

Impact of graphite gasket/duplex stainless steel couples on crevice chemistry and likelihood of crevice attack in seawater  

SciTech Connect (OSTI)

Electrochemical polarization measurements have been made on a graphite laminate gasket and a super-duplex stainless steel (DSS) in deaerated IM NaCl solution over a range of pH. The open circuit potential of the graphite is significantly more noble than that of the duplex stainless steel and the kinetics of the hydrogen ion reduction are greater at potentials more positive than about 0.0 V SCE. The data were used as input to a model of crevice chemistry and predictions made for potentials up to +0.4 V SCE. For crevices of parallel plates of DSS-DSS and DSS-Plastic, the usual acidic conditions were predicted but for a DSS-Graphite combination the pH was predicted to be alkaline. The latter is a consequence of the enhanced kinetics for cathodic reduction of hydrogen ions and water on the graphite which, when contained within the crevice, act to elevate the pH. The predictions suggest that coupling to graphite, contained within the crevice, may act to prevent crevice corrosion initiation in contrast to the usual perception of behavior when coupling to more noble materials. In practice, there have been significant crevice corrosion failures of a super-duplex stainless steel associated with graphite gaskets. However, in all cases, the failures were in chlorinated systems for which the corrosion potentials are particularly high and beyond the range for which a benefit from graphite could be anticipated.

Turnbull, A. [National Physical Lab., Teddington (United Kingdom). Centre for Materials Measurement and Technology

1998-12-31T23:59:59.000Z

347

Feasibility of re-melting NORM-contaminated scrap metal  

SciTech Connect (OSTI)

Naturally occurring radioactive materials (NORM) sometimes accumulate inside pieces of equipment associated with oil and gas production and processing activities. Typically, the NORM accumulates when radium that is present in solution in produced water precipitates out in scale and sludge deposits. Scrap equipment containing residual quantities of these NORM-bearing scales and sludges can present a waste management problem if the radium concentrations exceed regulatory limits or activate the alarms on radiation screening devices installed at most scrap metal recycling facilities. Although NORM-contaminated scrap metal currently is not disposed of by re-melting, this form of recycling could present a viable disposition option for this waste stream. Studies indicate that re-melting NORM-contaminated scrap metal is a viable recycling option from a risk-based perspective. However, a myriad of economic, regulatory, and policy issues have caused the recyclers to turn away virtually all radioactive scrap metal. Until these issues can be resolved, re-melting of the petroleum industry's NORM-impacted scrap metal is unlikely to be a widespread practice. This paper summarizes the issues associated with re-melting radioactive scrap so that the petroleum industry and its regulators will understand the obstacles. This paper was prepared as part of a report being prepared by the Interstate Oil and Gas Compact Commission's NORM Subcommittee.

Winters, S. J.; Smith, K. P.

1999-10-26T23:59:59.000Z

348

THE CONTRIBUTION OF GREENLAND ICE SHEET MELTING TO  

E-Print Network [OSTI]

THE CONTRIBUTION OF GREENLAND ICE SHEET MELTING TO GLOBAL SEA-LEVEL CHANGE Conor Mc three major sources, the Greenland ice sheet, Antarctica, and other eustatic components. Each has its own predictable spatial signal, and particular attention was paid to the Greenland ice sheet, given

349

THERMODYNAMIC AND TRANSPORT PROPERTIES OF SILICATE MELTS AND MAGMA  

E-Print Network [OSTI]

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

Spera, Frank J.

350

Laser thermoelastic generation in metals above the melt threshold  

SciTech Connect (OSTI)

An approach is presented for calculating thermoelastic generation of ultrasound in a metal plate exposed to nanosecond pulsed laser heating, sufficient to cause melting but not ablation. Detailed consideration is given to the spatial and temporal profiles of the laser pulse, penetration of the laser beam into the sample, the appearance and subsequent growth and then contraction of the melt pool, and the time dependent thermal conduction in the melt and surrounding solid throughout. The excitation of the ultrasound takes place during and shortly after the laser pulse and occurs predominantly within the thermal diffusion length of a micron or so beneath the surface. It is shown how, because of this, the output of the thermal simulations can be expressed as axially symmetric transient radial and normal surface force distributions. The epicentral displacement response to these force distributions is obtained by two methods, the one based on the elastodynamic Green's functions for plate geometry determined by the Cagniard generalized ray method and the other using a finite element numerical method. The two approaches are in very close agreement. Numerical simulations are reported on the epicentral displacement response of a 3.12 mm thick tungsten plate irradiated with a 4 ns pulsed laser beam with Gaussian spatial profile, at intensities below and above the melt threshold.

Every, A. G. [School of Physics, University of the Witwatersrand, PO Wits 2050 (South Africa)] [School of Physics, University of the Witwatersrand, PO Wits 2050 (South Africa); Utegulov, Z. N. [Department of Physics, School of Science and Technology, Nazarbayev University, Astana 010000 (Kazakhstan)] [Department of Physics, School of Science and Technology, Nazarbayev University, Astana 010000 (Kazakhstan); Veres, I. A. [RECENDT Research Center for Non-Destructive Testing GmbH, A-4040 Linz (Austria)] [RECENDT Research Center for Non-Destructive Testing GmbH, A-4040 Linz (Austria)

2013-11-28T23:59:59.000Z

351

Potential for tunneling based on rock and soil melting. Abstracts  

SciTech Connect (OSTI)

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

Rowley, J.C.

1985-01-01T23:59:59.000Z

352

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

SciTech Connect (OSTI)

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

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

1995-01-01T23:59:59.000Z

353

USING THE UTAH ENERGY BALANCE SNOW MELT MODEL TO QUANTIFY SNOW AND GLACIER MELT IN THE HIMALAYAN REGION  

E-Print Network [OSTI]

-Himalayan (HKH) region are highly disaster prone and have wide variety of water resources problems. Bangladesh, and for water resources management and flood protection. Access to and monitoring of the glaciers and their melt information to improve water resources decision making and management. In this paper we report

Tarboton, David

354

PHYSICAL REVIEW B 84, 092102 (2011) Melting temperature of tungsten from two ab initio approaches  

E-Print Network [OSTI]

PHYSICAL REVIEW B 84, 092102 (2011) Melting temperature of tungsten from two ab initio approaches L the melting temperature of tungsten by two ab initio approaches. The first approach can be divided into two

Alfè, Dario

2011-01-01T23:59:59.000Z

355

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

E-Print Network [OSTI]

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

356

Effect of grain size on the melting point of confined thin aluminum films  

SciTech Connect (OSTI)

The melting of aluminum thin film was studied by a molecular dynamics (MD) simulation technique. The effect of the grain size and type of confinement was investigated for aluminum film with a constant thickness of 4?nm. The results show that coherent intercrystalline interface suppress the transition of solid aluminum into liquid, while free-surface gives melting point depression. The mechanism of melting of polycrystalline aluminum thin film was investigated. It was found that melting starts at grain boundaries and propagates to grain interiors. The melting point was calculated from the Lindemann index criterion, taking into account only atoms near to grain boundaries. This made it possible to extend melting point calculations to bigger grains, which require a long time (in the MD scale) to be fully molten. The results show that 4?nm thick film of aluminum melts at a temperature lower than the melting point of bulk aluminum (933?K) only when the grain size is reduced to 6?nm.

Wejrzanowski, Tomasz; Lewandowska, Malgorzata; Sikorski, Krzysztof; Kurzydlowski, Krzysztof J. [Materials Design Division, Faculty of Materials Science and Engineering, Warsaw University of Technology, Woloska 141, 02-507 Warsaw (Poland)

2014-10-28T23:59:59.000Z

357

Prices include compostable serviceware and linen tablecloths  

E-Print Network [OSTI]

APPETIZERS Prices include compostable serviceware and linen tablecloths for the food tables.ucdavis.edu. BUTTERNUT SQUASH & BLACK BEAN ENCHILADAS #12;BUFFETS Prices include compostable serviceware and linen

California at Davis, University of

358

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

E-Print Network [OSTI]

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

Cohen, Barbara Anne

359

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

E-Print Network [OSTI]

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

Thompson, Michael

360

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

E-Print Network [OSTI]

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

Beckermann, Christoph

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

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

E-Print Network [OSTI]

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

Feltham, Daniel

362

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

SciTech Connect (OSTI)

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

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

2014-05-15T23:59:59.000Z

363

Ion fractionation and percolation in ice cores with seasonal melting John C. Moore*, Aslak Grinsted **  

E-Print Network [OSTI]

and with the type of data that was expected to come from ice caps with seasonal melt. The objective of this paperIon fractionation and percolation in ice cores with seasonal melting John C. Moore*, Aslak Grinsted that suffer limited seasonal melting. We show that the impact in the case of at least one Svalbard ice core

Moore, John

364

Basal melting of snow on early Mars: A possible origin of some valley Michael H. Carr  

E-Print Network [OSTI]

that valley networks could have formed as a result of basal melting of thick snow and ice deposits. Depending in part by basal melting of the south polar cap [Clifford, 1987], this cannot be the only mechanismBasal melting of snow on early Mars: A possible origin of some valley networks Michael H. Carr U. S

Head III, James William

365

Melting of small Arctic ice caps observed from ERS scatterometer time series  

E-Print Network [OSTI]

Melting of small Arctic ice caps observed from ERS scatterometer time series Laurence C. Smith,1 of melt onset can be observed over small ice caps, as well as the major ice sheets and multi-year sea ice for 14 small Arctic ice caps from 1992­2000. Interannual and regional variability in the timing of melt

Smith, Laurence C.

366

METHODOLOGICAL RE-EVALUATION OF THE ELECTRICAL CONDUCTIVITY OF SILICATE MELTS  

E-Print Network [OSTI]

1 Revised ms METHODOLOGICAL RE-EVALUATION OF THE ELECTRICAL CONDUCTIVITY OF SILICATE MELTS A in laboratory on silicate melts are used to interpret magnetotelluric anomalies. On the basis of two- and four to small chemical and physical changes, it represents a subtle probe for studying silicate melts properties

Boyer, Edmond

367

Use of coal tar pitch and petroleum bitumen in the production of thermally expanded graphite (Short Communication)  

SciTech Connect (OSTI)

The applicability of coal tar pitch and petroleum bitumen to the production of thermally expanded graphite was studied. The dependence of the coefficient of thermal expansion and the specific surface area on the amount of added substances was examined.

T.P. Miloshenko; O.Yu. Fetisova; M.L. Shchipko; B.N. Kuznetsov [Russian Academy of Sciences, Krasnoyarsk (Russia). Institute of Chemistry and Chemical Technology

2008-06-15T23:59:59.000Z

368

Abundances of presolar graphite and SiC from supernovae and AGB stars in the Murchison meteorite  

SciTech Connect (OSTI)

Pesolar graphite grains exhibit a range of densities (1.65 – 2.20 g/cm{sup 3}). We investigated abundances of presolar graphite grains formed in supernovae and in asymptotic giant branch (AGB) stars in the four density fractions KE3, KFA1, KFB1 and KFC1 extracted from the Murchison meteorite to probe dust productions in these stellar sources. Seventy-six and 50% of the grains in the low-density fractions KE3 and KFA1, respectively, are supernova grains, while only 7.2% and 0.9% of the grains in the high-density fractions KFB1 and KFC1 have a supernova origin. Grains of AGB star origin are concentrated in the high-density fractions KFB1 and KFC1. From the C isotopic distributions of these fractions and the presence of s-process Kr with {sup 86}Kr/{sup 82}Kr?=?4.43±0.46 in KFC1, we estimate that 76% and 80% of the grains in KFB1 and KFC1, respectively, formed in AGB stars. From the abundance of graphite grains in the Murchison meteorite, 0.88 ppm, the abundances of graphite from supernovae and AGB stars are 0.24 ppm and 0.44 ppm, respectively: the abundances of graphite in supernovae and AGB stars are comparable. In contrast, it has been known that 1% of SiC grains formed in supernovae and 95% formed in AGB stars in meteorites. Since the abundance of SiC grains is 5.85 ppm in the Murchison meteorite, the abundances of SiC from supernovae and AGB stars are 0.063 ppm and 5.6 ppm, respectively: the dominant source of SiC grains is AGB stars. Since SiC grains are harder and likely to survive better in space than graphite grains, the abundance of supernova graphite grains, which is higher than that of supernova SiC grains, indicates that supernovae proficiently produce graphite grains. Graphite grains from AGB stars are, in contrast, less abundant that SiC grains from AGB stars (0.44 ppm vs. 5.6 ppm). It is difficult to derive firm conclusions for graphite and SiC formation in AGB stars due to the difference in susceptibility to grain destruction. Metallicity of the parent AGB stars of graphite grains is much lower than that of SiC grains and the difference in metallicity might also have affected to the difference in the abundances in the Murchison meteorite.

Amari, Sachiko; Zinner, Ernst [McDonnell Center for the Space Sciences and the Physics Department, Washington University, One Brookings Dr., St. Louis, MO 63130 (United States); Gallino, Roberto [Dipartimento di Fisica, Università di Torino, Via P. Giuria 1, I-10125 Torino (Italy)

2014-05-02T23:59:59.000Z

369

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

SciTech Connect (OSTI)

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

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

1993-11-01T23:59:59.000Z

370

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

E-Print Network [OSTI]

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

Hillman, Daniel C

1981-01-01T23:59:59.000Z

371

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

SciTech Connect (OSTI)

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

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

2014-11-01T23:59:59.000Z

372

Electrochemical and Solid-State Lithiation of Graphitic C3N4  

SciTech Connect (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

373

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

SciTech Connect (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

374

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

SciTech Connect (OSTI)

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

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

1996-08-01T23:59:59.000Z

375

Continious production of exfoliated graphite composite compositions and flow field plates  

DOE Patents [OSTI]

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

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

2010-07-20T23:59:59.000Z

376

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

E-Print Network [OSTI]

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

377

CO2 isotopes as tracers of firn air diffusion and age in an Arctic ice cap with summer melting, Devon Island, Canada  

E-Print Network [OSTI]

and the effects of summer melting. The 14 CO2 profile from the permeable firn includes the 1963 thermonuclear peak, and accumulation rates were calibrated with the depth of the 1963 thermonuclear 3 H peak. The average ages for CO2 and the ice matrix. Calibrated with the 1963 peak for thermonuclear 14 CO2, a 21.2-year reaction halftime

Chappellaz, Jérôme

378

Polymer crystal-melt interfaces and nucleation in polyethylene  

E-Print Network [OSTI]

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

Scott T. Milner

2010-09-22T23:59:59.000Z

379

Vacancies in Al after pulsed electron beam melting  

SciTech Connect (OSTI)

We have used transmission electron microscopy (TEM) to study the retention of vacancies in Al after rapid melting and resolidification of a thin (approx. 3 ..mu..m) surface layer using a pulsed (approx.50 ns) electron beam. After pulsing and aging at room temperature, TEM examination showed dislocation loops, which are interpreted to be due to the coalescence of the quenched-in vacancies on )111) planes as is the case for the loops observed in earlier furnace quenching studies. Our results indicate that the rapid melting and resolidification leaves a high vacancy concentration (approx.100 ppm) in the resolidified Al. Heat transport calculations show that cooling rates for the pulse heated samples (approx.10/sup 8/ K/s) are much higher than those achieved by conventional quenching techniques (approx. 10/sup 4/ K/s).

Follstaedt, D.M.; Wampler, W.R.

1981-02-01T23:59:59.000Z

380

Simulation of multicomponent evaporation in electron beam melting and refining  

SciTech Connect (OSTI)

Experimental results and a mathematical model are presented to describe differential evaporation rates in electron beam melting of titanium alloys containing aluminum and vanadium. Experiments characterized the evaporation rate of commercially pure titanium, and vapor composition over titanium with up to 6% Al and 4.5% V content as a function of beam power, scan frequency and background pressure. The model is made up of a steady-state heat and mass transport model of a melting hearth and a model of transient thermal and flow behavior near the surface. Activity coefficients for aluminum and vanadium in titanium are roughly estimated by fitting model parameters to experimental results. Based on the ability to vary evaporation rate by 10-15% using scan frequency alone, we discuss the possibility of on-line composition control by means of intelligent manipulation of the electron beam.

Powell, A.; Szekely, J. [Massachusetts Inst. of Tech., Cambridge, MA (United States); Van Den Avyle, J.; Damkroger, B. [Sandia National Labs., Albuquerque, NM (United States)

1996-06-01T23:59:59.000Z

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.


381

Hydrodynamic coarsening in phase-separated silicate melts  

E-Print Network [OSTI]

Using in-situ synchrotron tomography, we investigate the coarsening dynamics of barium borosilicate melts during phase separation. The 3-D geometry of the two interconnected phases is determined thanks to image processing. We observe a linear growth of the size of domains with time, at odds with the sublinear diffusive growth usually observed in phase-separating glasses or alloys. Such linear coarsening is attributed to viscous flow inside the bicontinuous phases, and quantitative measurements show that the growth rate is well explained by the ratio of surface tension over viscosity. The geometry of the domains is shown to be statistically similar at different times, provided that the microstructure is rescaled by the average domain size. Complementary experiments on melts with a droplet morphology demonstrate that viscous flow prevails over diffusion in the large range of domain sizes measured in our experiments (1 - 80 microns).

David Bouttes; Océane Lambert; Corinne Claireaux; William Woelffel; Davy Dalmas; Emmanuelle Gouillart; Pierre Lhuissier; Luc Salvo; Elodie Boller; Damien Vandembroucq

2015-02-12T23:59:59.000Z

382

Mode II delamination fracture toughness of unidirectional graphite/epoxy composites  

E-Print Network [OSTI]

(August 1986) Carlos Roberto Corleto Nena, B. S. , Nechanical Engineering Texas AaN University Chairmam of Advisory Committee: Dr. Walter L. Bradley The mode II delamination fracture toughness of a ductile and a brittle unidirectional graphite... applications is their inherently poor damage tolerance for delamination. The resistance of composites to delamination can be well characterized by the delamination fracture toughness, measured as energy dissipated per unit area of crack growth. Where...

Corleto Mena, Carlos Roberto

1986-01-01T23:59:59.000Z

383

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

SciTech Connect (OSTI)

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

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

1981-01-01T23:59:59.000Z

384

A solution to level 3 dismantling of gas-cooled reactors: Graphite incineration  

SciTech Connect (OSTI)

This paper presents an approach developed to solve the specific decommissioning problems of the G2 and G3 gas cooled reactors at Marcoule and the strategy applied with emphasis in incinerating the graphite core components, using a fluidized-bed incinerator developed jointly between the CEA and FRAMATOME. The incineration option was selected over subsurface storage for technical and economic reasons. Studies have shown that gaseous incineration releases are environmentally acceptable.

Dubourg, M. [FRAMATOME, Paris-La Defense (France)

1993-12-31T23:59:59.000Z

385

Mode I transverse cracking in an epoxy and a graphite fiber reinforced epoxy  

E-Print Network [OSTI]

tension specimens tested under intermittent fixed grip conditions. The graphite/epoxy composite manifests a significant increase in fracture toughness with crack length as the crack length to specimen width ratio I'a/w) exceeds 0. 5. This increase... in toughness is correlated with an increase in fiber break- age and pullout and permanent matrix deformation. Results obtained in this study are compared with results from studies of delamination fracture toughness of the same composite material to show...

Williams, David Robert

1981-01-01T23:59:59.000Z

386

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

SciTech Connect (OSTI)

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

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

2013-07-01T23:59:59.000Z

387

Advanced coal-fired glass melting development program  

SciTech Connect (OSTI)

The objective of Phase 1 of the current contract was to verify the technical feasibility and economic benefits of Vortec's advanced combustion/melting technology using coal as the fuel of choice. The objective of the Phase 2 effort was to improve the performance of the primary components and demonstrate the effective operation of a subscale process heater system integrated with a glass separator/reservoir. (VC)

Not Available

1991-05-01T23:59:59.000Z

388

Proceedings of ALGORITMY 2005 BOUNDARY CONTROL OF SEMICONDUCTOR MELTS  

E-Print Network [OSTI]

-type functionals of the form J(u, c) = 1 2 T 0 |u - u|2 ddt + 2 T 0 c (2 c + 2 ct ) ddt,(1) whereas goal (ii) may be related to minimal values of vorticity-type functionals of the form J(u, c) = 1 2 T 0 |curlu|2 ddt + 2 T 0 c (2 c + 2 ct ) ddt .(2) Above, u denotes the flow velocity vector field in the melt, and u

Hinze, Michael

389

Dislocation-mediated melting of one-dimensional Rydberg crystals  

SciTech Connect (OSTI)

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

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

2011-08-15T23:59:59.000Z

390

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

SciTech Connect (OSTI)

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

Duffy, Stephen

2013-09-09T23:59:59.000Z

391

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

E-Print Network [OSTI]

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

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

2003-01-01T23:59:59.000Z

392

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

DOE Patents [OSTI]

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

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

2014-04-01T23:59:59.000Z

393

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

E-Print Network [OSTI]

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

Amini, Shaahin

2012-01-01T23:59:59.000Z

394

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

SciTech Connect (OSTI)

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

NONE

1996-11-01T23:59:59.000Z

395

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

SciTech Connect (OSTI)

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

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

2012-07-01T23:59:59.000Z

396

A computational model for viscous fluid flow, heat transfer, and melting in in situ vitrification melt pools  

SciTech Connect (OSTI)

MAGMA is a FORTRAN computer code designed to viscous flow in in situ vitrification melt pools. It models three-dimensional, incompressible, viscous flow and heat transfer. The momentum equation is coupled to the temperature field through the buoyancy force terms arising from the Boussinesq approximation. All fluid properties, except density, are assumed variable. Density is assumed constant except in the buoyancy force terms in the momentum equation. A simple melting model based on the enthalpy method allows the study of the melt front progression and latent heat effects. An indirect addressing scheme used in the numerical solution of the momentum equation voids unnecessary calculations in cells devoid of liquid. Two-dimensional calculations can be performed using either rectangular or cylindrical coordinates, while three-dimensional calculations use rectangular coordinates. All derivatives are approximated by finite differences. The incompressible Navier-Stokes equations are solved using a new fully implicit iterative technique, while the energy equation is differenced explicitly in time. Spatial derivatives are written in conservative form using a uniform, rectangular, staggered mesh based on the marker and cell placement of variables. Convective terms are differenced using a weighted average of centered and donor cell differencing to ensure numerical stability. Complete descriptions of MAGMA governing equations, numerics, code structure, and code verification are provided. 14 refs.

McHugh, P.R.; Ramshaw, J.D.

1991-11-01T23:59:59.000Z

397

Impact of graphite gasket/duplex stainless steel couples on crevice chemistry and the likelihood of crevice attack in seawater  

SciTech Connect (OSTI)

Crevice corrosion in seawater usually is assumed to be induced by attainment of a critical solution chemistry. Electrochemical polarization measurements were made on a graphite laminate gasket and a super-duplex stainless steel (DSS) in deaerated 1M sodium chloride (NaCl) solution over a range of pH. The open-circuit potential of the graphite was significantly more noble than that of the DSS, and the kinetics of the hydrogen ion reduction were greater at potentials more positive than {approximately} 0.0 V{sub SCE}. Data were used as input to a model of crevice chemistry, and predictions were made for potentials up to 0.4 V{sub SCE}. For crevices of parallel plates of DSS-DSS and DSS-plastic, the usual acidic conditions were predicted. However, for a DSS-graphite combination, there was no significant decrease in pH. The latter was a consequence of the enhanced kinetics for cathodic reduction of hydrogen ions and water on the graphite which, when confined within the crevice, opposed the fall in pH associated with the metal-ion hydrolysis process. The predictions suggested that coupling to graphite, contained within the crevice, may act to prevent crevice corrosion initiation in contrast to the usual perception of behavior when coupling to more noble materials. In practice, there have been significant crevice corrosion failures of DSS associated with graphite gaskets. However, in all cases, the failures were in chlorinated systems for which corrosion potentials are particularly high and beyond the range for which a benefit from graphite could be anticipated.

Turnbull, A. [National Physical Lab., Middlesex (United Kingdom). Centre for Materials Measurement and Technology

1999-02-01T23:59:59.000Z

398

Author's personal copy Coexisting silicate melt inclusions and H2O-bearing, CO2-rich fluid inclusions in mantle  

E-Print Network [OSTI]

Author's personal copy Coexisting silicate melt inclusions and H2O-bearing, CO2-rich fluid­Pannonian region Hungary C­O­H­S fluid inclusions Peridotite xenoliths Silicate melt inclusions Volatile (fluid)­silicate melt immiscibility Coexisting fluid inclusions and silicate melt inclusions, trapped as primary

Bodnar, Robert J.

399

Synthesis of SiO{sub 2}/?-SiC/graphite hybrid composite by low temperature hot filament chemical vapor deposition  

SciTech Connect (OSTI)

?-SiC thin films were synthesized directly on graphite by hot filament chemical vapor deposition at low temperature. SiH{sub 4} diluted in hydrogen was employed as the silicon source, while graphite was functioned as both substrate and carbon source for the as-grown ?-SiC films. X-ray diffraction and Fourier transform infrared analysis indicate that SiO{sub 2}/?-SiC/graphite hybrid composite was formed after post annealing treatment, and its crystalline quality can be remarkably improved under optimized annealing conditions. The possible growth mechanism was proposed based on in situ etching of graphite by reactive hydrogen radicals at the atomic level.

Zhang, Zhikun; Bi, Kaifeng; Liu, Yanhong; Qin, Fuwen; Liu, Hongzhu [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)] [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Bian, Jiming, E-mail: jmbian@dlut.edu.cn [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China) [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Key Laboratory of Inorganic Coating Materials, Chinese Academy of Sciences, Shanghai 200050 (China); Zhang, Dong [New Energy Source Research Center of Shenyang Institute of Engineering, Shengyang 110136 (China)] [New Energy Source Research Center of Shenyang Institute of Engineering, Shengyang 110136 (China); Miao, Lihua [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China) [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Department of Computer and Mathematical Basic Teaching, Shenyang Medical College, Shenyan 110034 (China)

2013-11-18T23:59:59.000Z

400

Melt coolability modeling and comparison to MACE test results  

SciTech Connect (OSTI)

An important question in the assessment of severe accidents in light water nuclear reactors is the ability of water to quench a molten corium-concrete interaction and thereby terminate the accident progression. As part of the Melt Attack and Coolability Experiment (MACE) Program, phenomenological models of the corium quenching process are under development. The modeling approach considers both bulk cooldown and crust-limited heat transfer regimes, as well as criteria for the pool thermal hydraulic conditions which separate the two regimes. The model is then compared with results of the MACE experiments.

Farmer, M.T.; Sienicki, J.J.; Spencer, B.W.

1992-04-01T23:59:59.000Z

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

Melt coolability modeling and comparison to MACE test results  

SciTech Connect (OSTI)

An important question in the assessment of severe accidents in light water nuclear reactors is the ability of water to quench a molten corium-concrete interaction and thereby terminate the accident progression. As part of the Melt Attack and Coolability Experiment (MACE) Program, phenomenological models of the corium quenching process are under development. The modeling approach considers both bulk cooldown and crust-limited heat transfer regimes, as well as criteria for the pool thermal hydraulic conditions which separate the two regimes. The model is then compared with results of the MACE experiments.

Farmer, M.T.; Sienicki, J.J.; Spencer, B.W.

1992-01-01T23:59:59.000Z

402

Creep measuring device for low melting point metals  

E-Print Network [OSTI]

that there is little concern about the mechanical interaction of the coolant in the solid state and the walls. Because of its suitable thermophysicsl properties, lithium has been selected for the coolant in the SP-100 space reactor design. During launch, the lithium... properties of lithium. An experiment was conducted on lead at 90% of melting temperature (541 K). The results of this experiment agreed well with theoretical predictions of the Harper-Dorn creep model. The three predicted stages of creep were observed...

Portal, Marc-Emmanuel Gilbert

1987-01-01T23:59:59.000Z

403

Composition monitoring of electron beam melting processes using diode lasers  

SciTech Connect (OSTI)

Electron beam melting processes are used to produce high purity alloys for a wide range of applications. Real time monitoring of the alloy constituents, however, has historically been difficult. Absorption spectroscopy using diode lasers provides a means for measuring constituent densities, and hence alloy composition, in real time. Diode lasers are suggested because they are inexpensive and require little maintenance. There is increasing interest in the composition and quality control of titanium alloys used in aircraft parts. For this reason we describe a proposed system for composition monitoring of titanium alloys. Performance and cost of the proposed system is addressed. We discuss the applicability of this approach to other alloys.

Berzins, L.V.

1991-11-20T23:59:59.000Z

404

Method for harvesting single crystals from a peritectic melt  

DOE Patents [OSTI]

A method of preparing single crystals is disclosed. The method of preparation involves preparing precursor materials of a particular composition, heating the precursor material to achieve a peritectic mixture of peritectic liquid and crystals, cooling the peritectic mixture to quench directly the mixture on a porous, wettable inert substrate to wick off the peritectic liquid, leaving single crystals on the porous substrate. Alternatively, the peritectic mixture can be cooled to a solid mass and reheated on a porous, inert substrate to melt the matrix of peritectic fluid while leaving the crystals unmelted, allowing the wicking away of the peritectic liquid. 2 figs.

Todt, V.R.; Sengupta, S.; Shi, D.

1996-08-27T23:59:59.000Z

405

Method for harvesting single crystals from a peritectic melt  

DOE Patents [OSTI]

A method of preparing single crystals. The method of preparation involves preparing precursor materials of a particular composition, heating the precursor material to achieve a peritectic mixture of peritectic liquid and crystals, cooling the peritectic mixture to quench directly the mixture on a porous, wettable inert substrate to wick off the peritectic liquid, leaving single crystals on the porous substrate. Alternatively, the peritectic mixture can be cooled to a solid mass and reheated on a porous, inert substrate to melt the matrix of peritectic fluid while leaving the crystals unmelted, allowing the wicking away of the peritectic liquid.

Todt, Volker R. (Lemont, IL); Sengupta, Suvankar (Columbus, OH); Shi, Donglu (Cincinnati, OH)

1996-01-01T23:59:59.000Z

406

Method to decrease loss of aluminum and magnesium melts  

DOE Patents [OSTI]

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

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

2002-01-01T23:59:59.000Z

407

An Extendible Reconfigurable Robot Based on Hot Melt Adhesives  

E-Print Network [OSTI]

(25mm× 30mm) that is heated and cooled to form or break bonds with the HMA in contact with the connection surface. A Peltier element (Cente- nary Materials, TEC1-01703, 15mm× 15mm, 3.9W) is used for thermo-electric cooling and two resistors (Vishay, PR... bounds of self-reconfiguration with our robotic (a) melting cavity HMA stick nozzle servo motor (b) connection surface peltier element power resisitor (c) Fig. 3 The robot base is extended with a structure from wood blocks combined with an HMA tool (a...

Brodbeck, Luzius; Iida, Fumiya

2015-01-01T23:59:59.000Z

408

Hydrostatic extrusion of Cu-Ag melt spun ribbon  

DOE Patents [OSTI]

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

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

1998-01-01T23:59:59.000Z

409

Hydrostatic extrusion of Cu-Ag melt spun ribbon  

DOE Patents [OSTI]

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

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

1998-09-08T23:59:59.000Z

410

Sandia National Laboratories: Molten Salt Test Loop Melted Salt  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 -theErik Spoerke SSLS ExhibitIowaLosSandiaManagementMolecularFacilityMoltenMelted

411

Net Taxable Gasoline Gallons (Including Aviation Gasoline)  

E-Print Network [OSTI]

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

412

Implications of Graphite Radiation Damage on the Neutronic, Operational, and Safety Aspects of Very High Temperature Reactors  

SciTech Connect (OSTI)

In both the prismatic and pebble bed designs of Very High Temperature Reactors (VHTR), the graphite moderator is expected to reach exposure levels of 1021 to 1022 n/cm2 over the lifetime of the reactor. This exposure results in damage to the graphite structure. In this work, molecular dynamic and ab initio molecular static calculations will be used to: 1) simulate radiation damage in graphite under various irradiation and temperature conditions, 2) generate the thermal neutron scattering cross sections for damaged graphite, and 3) examine the resulting microstructure to identify damage formations that may produce the high-temperature Wigner effect. The impact of damage on the neutronic, operational and safety behavior of the reactor will be assessed using reactor physics calculations. In addition, tests will be performed on irradiated graphite samples to search for the high-temperature Wigner effect, and phonon density of states measurements will be conducted to quantify the effect on thermal neutron scattering cross sections using these samples.

Hawari, Ayman I

2011-08-30T23:59:59.000Z

413

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

SciTech Connect (OSTI)

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

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

2000-04-11T23:59:59.000Z

414

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

SciTech Connect (OSTI)

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

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

2000-03-22T23:59:59.000Z

415

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

SciTech Connect (OSTI)

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

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

2014-06-16T23:59:59.000Z

416

Spatio-temporal mapping of ablated species in ultrafast laser-produced graphite plasmas  

SciTech Connect (OSTI)

We studied the spatial and temporal distributions of ionic, neutral, and molecular species generated by femtosecond laser produced plasma under varying ambient nitrogen gas pressures. Plasmas were generated by irradiating planar graphite targets using 40 fs pulses of 800 nm radiation from a Ti:Sapphire laser. The results show that in the presence of an ambient gas, the molecular species spatial extension and lifetime are directly correlated to the evolution of excited ions. The present studies also provide valuable insights into the evolution history of various species and their excitation during ultrafast laser ablation.

Al-Shboul, K. F.; Harilal, S. S.; Hassanein, A. [Center for Materials Under Extreme Environment, School of Nuclear Engineering, Purdue University, West Lafayette, Indiana 47907 (United States)

2012-05-28T23:59:59.000Z

417

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

SciTech Connect (OSTI)

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

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

2014-11-01T23:59:59.000Z

418

Interfacial tension between aluminum and chloride-fluoride melts  

SciTech Connect (OSTI)

Scrap and recycled aluminum have to be remelted and refined before being made into useful new products. This often involves melting the aluminum under a molten salt cover in order to prevent oxidation and to enhance the coalescence and recovery of the molten metal. A technique was developed for the measurement of the interfacial tension between liquid metals and molten salts at elevated temperatures. The technique is based on the measurement of the capillary depression occurring when a capillary, which is moved vertically down through the molten salt layer, passes through the salt/metal interface. The depression is measured by simultaneous video recording of the immersion height of the alumina capillary and the position of a liquid meniscus in a horizontal tube connected to the alumina capillary. The interfacial tension was measured for (a) aluminum and an equimolar melt of NaCl + KCl with several salt additions at 1,000 K, (b) aluminum and NaCl + NaF at 1,123 K, and (c) aluminum and NaCl + KF at 1,123 K. It was found that the interfacial tension decreases with increasing amount of NaF, increases with the increasing amount of MgCl{sub 2} additions, remains unchanged with AlF{sub 3} additions, and slightly decreases with the addition of MgF{sub 2} and Na{sub 3}AlF{sub 6}.

Silny, A. [Slovak Academy of Sciences, Bratislava (Slovakia). Inst. of Inorganic Chemistry] [Slovak Academy of Sciences, Bratislava (Slovakia). Inst. of Inorganic Chemistry; Utigard, T.A. [Univ. of Toronto, Ontario (Canada). Dept. of Metallurgy and Materials Science] [Univ. of Toronto, Ontario (Canada). Dept. of Metallurgy and Materials Science

1996-11-01T23:59:59.000Z

419

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

420

Theoretical investigation of finite size effects at DNA melting  

E-Print Network [OSTI]

We investigated how the finiteness of the length of the sequence affects the phase transition that takes place at DNA melting temperature. For this purpose, we modified the Transfer Integral method to adapt it to the calculation of both extensive (partition function, entropy, specific heat, etc) and non-extensive (order parameter and correlation length) thermodynamic quantities of finite sequences with open boundary conditions, and applied the modified procedure to two different dynamical models. We showed that rounding of the transition clearly takes place when the length of the sequence is decreased. We also performed a finite-size scaling analysis of the two models and showed that the singular part of the free energy can indeed be expressed in terms of an homogeneous function. However, both the correlation length and the average separation between paired bases diverge at the melting transition, so that it is no longer clear to which of these two quantities the length of the system should be compared. Moreo...

Buyukdagli, S; Buyukdagli, Sahin; Joyeux, Marc

2007-01-01T23:59:59.000Z

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.


421

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

SciTech Connect (OSTI)

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

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

2014-04-28T23:59:59.000Z

422

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

DOE Patents [OSTI]

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

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

2014-07-01T23:59:59.000Z

423

EE Regional Technology Roadmap Includes comparison  

E-Print Network [OSTI]

EE Regional Technology Roadmap Includes comparison against 6th Power Plan (Update cyclically Data Clearinghouse BPA/RTF NEEA/Regional Programs Group Update Regional EE Technology Roadmap Lighting

424

DIDACTICAL HOLOGRAPHIC EXHIBIT INCLUDING (HOLOGRAPHIC TELEVISION)  

E-Print Network [OSTI]

DIDACTICAL HOLOGRAPHIC EXHIBIT INCLUDING HoloTV (HOLOGRAPHIC TELEVISION) José J. Lunazzi , DanielCampinasSPBrasil Abstract: Our Institute of Physics exposes since 1980 didactical exhibitions of holography in Brazil where

de Aguiar, Marcus A. M.

425

Gas storage materials, including hydrogen storage materials  

DOE Patents [OSTI]

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

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

2014-11-25T23:59:59.000Z

426

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

427

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

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

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

428

Mobile Melt-Dilute Technology Development Project FY 2005 Test Report  

SciTech Connect (OSTI)

The adaptation of Melt-Dilute technology to a mobile and deployable platform progressed with the installation of the prototype air-cooled induction furnace and power generator in an ISO cargo container. Process equipment tests were conducted in FY’05 on two fronts: the melt container and its associated hardware and the mobile furnace and generator. Container design was validated through tests at elevated temperature and pressure, under vacuum, and subjected to impact. The Mobile Melt-Dilute (MMD) furnace and power source tests were completed per the plan. The tests provided information necessary to successfully melt and dilute HEU research reactor fuel assemblies.

David A. Sell; Donald Fisher

2006-01-01T23:59:59.000Z

429

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

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

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

430

Exploration of coal-based pitch precursors for ultra-high thermal conductivity graphite fibers. Final report  

SciTech Connect (OSTI)

Goal was to explore the utility of coal-based pitch precursors for use in ultra high thermal conductivity carbon (graphite) fibers. From graphite electrode experience, it was established that coal-based pitches tend to form more highly crystalline graphite at lower temperatures. Since the funding was limited to year 1 effort of the 3 year program, the goal was only partially achieved. The coal-base pitches can form large domain mesophase in spite of high N and O contents. The mesophase reactivity test performed on one of the variants of coal-based pitch (DO84) showed that it was not a good candidate for carbon fiber processing. Optimization of WVU`s isotropic pitch process is required to tailor the pitch for carbon fiber processing. The hetero atoms in the coal pitch need to be reduced to improve mesophase formation.

Deshpande, G.V. [Amoco Performance Products, Inc., Alpharetta, GA (United States)

1996-12-27T23:59:59.000Z

431

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

SciTech Connect (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

432

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

SciTech Connect (OSTI)

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

White, Thornton C [SCRA Appiled R& D

2014-03-31T23:59:59.000Z

433

Melt mixing causes negative correlation of trace element enrichment and CO2 content prior to an Icelandic eruption  

E-Print Network [OSTI]

for datasets that include and exclude highly enriched inclusions. Elements anal- ysed with low precision (e.g. F and Sm), or that are strongly af- fected by PEC or diffusive alteration (e.g. MgO, FeO and H2O), are excluded to prevent the identification... the best enriched and depleted end-member compositions (Ce and Cd): C = [ XeCe + (1? Xe)Cd ] (1? F )D?1 (1) where C is the concentration of an element in a melt inclusion and D is the bulk partition coefficient of the assemblage removed dur- ing...

Neave, David A.; Maclennan, John; Edmonds, Marie; Thordarson, Thorvaldur

2014-06-13T23:59:59.000Z

434

Scramjet including integrated inlet and combustor  

SciTech Connect (OSTI)

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

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

1992-02-04T23:59:59.000Z

435

Graphene oxide sheets, the chemical exfoliation product of graphite powders and precursor for the bulk production of graphene based materials, are found to be  

E-Print Network [OSTI]

#12;Graphene oxide sheets, the chemical exfoliation product of graphite powders and precursor), is the product of chemical oxidation and exfoliation of graphite powders that was first synthesized over a cen atomic layer of sp2-hybridized carbon atoms (Fig. 1a). In 2004, it was isolated by mechanical exfoliation

Huang, Jiaxing

436

Coordinated TEM and NanoSIMS of Presolar Graphites T.K. Croat, F.J. Stadermann, and T.J. Bernatowicz*  

E-Print Network [OSTI]

, MO 63130 Presolar graphites are especially interesting in that they encapsulate many internal grains kamacite grains which was then encapsulated within a graphite with the isotopic signatures of a supernova, this condensation sequence implies an iron abundance that is considerably above the solar ratios in the gas from

437

Porous electrodes and prototypes of secondary cells based on a novel electrochemical system graphite-HBF{sub 4}-anthraquinone  

SciTech Connect (OSTI)

Porous electrodes and experimental prototypes of rechargeable batteries based on a novel electrochemical system graphite-HBF{sub 4} + tetrafluoroborate additives-anthraquinone are developed. Intercalation of anions in the graphite electrode is studied in detail and the intercalation potential is determined (E{sub i} {approximately} 1.55 V vs. Ag-AgCl). Side reactions proceeding concurrently with primary current-generating processes at the electrodes are described. Feasibility of hermetically sealing a battery based on the new system due to anthrahydroquinone`s ability to reduce oxygen that evolves during charging is demonstrated.

Barsukov, V.Z. [Institute of General and Inorganic Chemistry, Kiev (Ukraine); Barsukov, I.V.; Motronyuk, T.I. [Kiev Polytechnical Institute (Ukraine); Beck, F. [Univ. of Duisburg (Germany)

1995-04-01T23:59:59.000Z

438

Calculated criticality for sup 235 U/graphite systems using the VIM Monte Carlo code  

SciTech Connect (OSTI)

Calculations for highly enriched uranium and graphite systems gained renewed interest recently for the new production modular high-temperature gas-cooled reactor (MHTGR). Experiments to validate the physics calculations for these systems are being prepared for the Transient Reactor Test Facility (TREAT) reactor at Argonne National Laboratory (ANL-West) and in the Compact Nuclear Power Source facility at Los Alamos National Laboratory. The continuous-energy Monte Carlo code VIM, or equivalently the MCNP code, can utilize fully detailed models of the MHTGR and serve as benchmarks for the approximate multigroup methods necessary in full reactor calculations. Validation of these codes and their associated nuclear data did not exist for highly enriched {sup 235}U/graphite systems. Experimental data, used in development of more approximate methods, dates back to the 1960s. The authors have selected two independent sets of experiments for calculation with the VIM code. The carbon-to-uranium (C/U) ratios encompass the range of 2,000, representative of the new production MHTGR, to the ratio of 10,000 in the fuel of TREAT. Calculations used the ENDF/B-V data.

Collins, P.J.; Grasseschi, G.L.; Olsen, D.N. (Argonne National Lab.-West, Idaho Falls (United States)); Finck, P.J. (Argonne National Lab., IL (United States))

1992-01-01T23:59:59.000Z

439

Preparations and characterizations of novel graphite-like materials and some high oxidation state fluorine chemistry  

SciTech Connect (OSTI)

Novel graphite-like materials, BC{sub x} (6>x{ge}3), have been prepared using BCl{sub 3} and C{sub 6}H{sub 6} at 800--1000C, and C{sub x}N (14>x{ge}5) have been synthesized using C{sub 5}H{sub 5}N and Cl{sub 2} at 680C--986C. Bulk and thin film characterization were used to study the structure and bonding in these solids. C{sub 8}K(NH{sub 3}){sub 1.1} was prepared by reacting C{sub 8}K with gaseous NH{sub 3}. The carbon sub-lattice is hexagonal: a = 2.47 {Angstrom}, c = 6.47 {Angstrom}. The smaller a parameter and lower conductivity are attributed to smaller electron transfer from K to the conduction band solvation of K by NH{sub 3}. A simplified liquid phase method for synthesizing Li-graphite intercalation compounds has been developed; synthesis of a lamellar mixed conductor, C{sub x}{sup +}Li{sub 2}N{sup {minus}}, has been attempted. Stability and conductivity of (BN){sub 3}SO{sub 3}F have been studied; it was shown to be metallic with a specific conductivity of 1.5 S{center_dot}cm{sup {minus}1}. Its low conductivity is attributed to the low mobility of holes in BN sheets.

Shen, Ciping

1992-11-01T23:59:59.000Z

440

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

SciTech Connect (OSTI)

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

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

Electric Power Monthly, August 1990. [Glossary included  

SciTech Connect (OSTI)

The Electric Power Monthly (EPM) presents monthly summaries of electric utility statistics at the national, Census division, and State level. The purpose of this publication is to provide energy decisionmakers with accurate and timely information that may be used in forming various perspectives on electric issues that lie ahead. Data includes generation by energy source (coal, oil, gas, hydroelectric, and nuclear); generation by region; consumption of fossil fuels for power generation; sales of electric power, cost data; and unusual occurrences. A glossary is included.

Not Available

1990-11-29T23:59:59.000Z

442

Energy Consumption of Personal Computing Including Portable  

E-Print Network [OSTI]

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

Namboodiri, Vinod

443

Communication in automation, including networking and wireless  

E-Print Network [OSTI]

Communication in automation, including networking and wireless Nicholas Kottenstette and Panos J and networking in automation is given. Digital communication fundamentals are reviewed and networked control are presented. 1 Introduction 1.1 Why communication is necessary in automated systems Automated systems use

Antsaklis, Panos

444

Subterranean barriers including at least one weld  

DOE Patents [OSTI]

A subterranean barrier and method for forming same are disclosed, the barrier including a plurality of casing strings wherein at least one casing string of the plurality of casing strings may be affixed to at least another adjacent casing string of the plurality of casing strings through at least one weld, at least one adhesive joint, or both. A method and system for nondestructively inspecting a subterranean barrier is disclosed. For instance, a radiographic signal may be emitted from within a casing string toward an adjacent casing string and the radiographic signal may be detected from within the adjacent casing string. A method of repairing a barrier including removing at least a portion of a casing string and welding a repair element within the casing string is disclosed. A method of selectively heating at least one casing string forming at least a portion of a subterranean barrier is disclosed.

Nickelson, Reva A.; Sloan, Paul A.; Richardson, John G.; Walsh, Stephanie; Kostelnik, Kevin M.

2007-01-09T23:59:59.000Z

445

Completion strategy includes clay and precipitate control  

SciTech Connect (OSTI)

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

Sandy, T.; Gardner, G.R.

1985-05-06T23:59:59.000Z

446

Power generation method including membrane separation  

DOE Patents [OSTI]

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

Lokhandwala, Kaaeid A. (Union City, CA)

2000-01-01T23:59:59.000Z

447

Rotor assembly including superconducting magnetic coil  

DOE Patents [OSTI]

Superconducting coils and methods of manufacture include a superconductor tape wound concentrically about and disposed along an axis of the coil to define an opening having a dimension which gradually decreases, in the direction along the axis, from a first end to a second end of the coil. Each turn of the superconductor tape has a broad surface maintained substantially parallel to the axis of the coil.

Snitchler, Gregory L. (Shrewsbury, MA); Gamble, Bruce B. (Wellesley, MA); Voccio, John P. (Somerville, MA)

2003-01-01T23:59:59.000Z

448

Electric power monthly, September 1990. [Glossary included  

SciTech Connect (OSTI)

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)

Not Available

1990-12-17T23:59:59.000Z

449

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

E-Print Network [OSTI]

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

Peppas, Nicholas A.

450

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

451

IDENTIFICATION NUMBER: 4ME20 Abstract--Artificial welding of melt-textured YBCO blocks  

E-Print Network [OSTI]

1 IDENTIFICATION NUMBER: 4ME20 Abstract--Artificial welding of melt-textured YBCO blocks opens the superconducting quality of the welds, we have developed a Hall probe mapping system, able to record the local to characterize welded samples prepared with a new Ag induced surface melting joining technique. The magnetization

Politècnica de Catalunya, Universitat

452

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

SciTech Connect (OSTI)

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

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

2014-06-23T23:59:59.000Z

453

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

E-Print Network [OSTI]

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

Hussein, Ibnelwaleed A.

454

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

SciTech Connect (OSTI)

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

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

2014-02-07T23:59:59.000Z

455

Proceedings of the conference on electron beam melting and refining - state of the art 1996  

SciTech Connect (OSTI)

This conference proceedings summarizes state-of-the-art work in the field of electron-beam melting and refining, as presented at the 1996 conference. Papers are grouped as follows: invited papers; tutorial papers; electron beam melting related fundamentals; electron beam evaporation papers; and miscellaneous papers. Separate abstracts have been submitted to the energy database for some contributions to this proceedings.

Bakish, R. [ed.

1996-12-31T23:59:59.000Z

456

HOW IS THE GRANITE MELT FLOW NETWORK RECORDED IN MIGMATITES AND BY ASSOCIATED GRANITE PLUTONS?  

E-Print Network [OSTI]

1 HOW IS THE GRANITE MELT FLOW NETWORK RECORDED IN MIGMATITES AND BY ASSOCIATED GRANITE PLUTONS of granite magma during orogeny has important implications because melt transfer affects the thermal; Milord et al., 2001; Barraud et al., 2001a, 2001b). We also understand well how granite magma is emplaced

Solar, Gary S.

457

Measurement of the Melting Point Temperature of Several Lithium-Sodium-Beryllium Fluoride Salt (Flinabe) Mixtures  

SciTech Connect (OSTI)

The molten salt Flibe, a combination of lithium and beryllium fluorides studied for molten salt fission reactors, has been proposed as a breeder and coolant for fusion applications. The melting points of 2LiF-BeF{sub 2} and LiF-BeF{sub 2} are 460 deg. C and 363 deg. C, but LiF-BeF{sub 2} is rather viscous and has less lithium for breeding. In the Advanced Power Extraction (APEX) Program, concepts with a free flowing liquid for the first wall and blanket were investigated. Flinabe (a mixture of LiF, BeF{sub 2} and NaF) was selected for a molten salt design because a melting temperature below 350 deg. C appeared possible and this provided an attractive operating temperature window for a reactor. To confirm that a ternary salt with a low melting temperature existed, several combinations of the fluoride salts, LiF, NaF and BeF{sub 2}, were melted in a stainless steel crucible under vacuum. One had an apparent melting temperature of 305 deg. C. The test system, preparation of the mixtures, melting procedures and temperature curves for the melting and cooling are presented along with the apparent melting points. Thermal modeling of the salt pool and crucible is reported in an accompanying paper.

McDonald, J.M; Nygren, R.E.; Lutz, T.J.; Tanaka, T.J; Ulrickson, M.A.; Boyle, T.J.; Troncosa, K.P. [Sandia National Laboratories (United States)

2005-04-15T23:59:59.000Z

458

Generation of CO2-rich melts during basalt magma ascent and degassing  

E-Print Network [OSTI]

Generation of CO2-rich melts during basalt magma ascent and degassing Michel Pichavant . Ida Di magma degassing, continuous decompressions of volatile-bearing (2.7-3.8 wt% H2O, 600-1300 ppm CO2 to solubilities. In contrast, the rate of vesiculation controls the final melt CO2 concentration. High

Boyer, Edmond

459

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

E-Print Network [OSTI]

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

460

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

E-Print Network [OSTI]

). The experiments were conducted at pressures of 1.0 GPa and temperatures of 1250 °C. The rare earth elements (La polymerisation of the melt, apatite/melt partition coefficients for the rare earth elements increase for about occurring apatites contain large amounts of the rare earth elements and Sr, it has been well known

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


461

High field strength element/rare earth element fractionation during partial melting in the presence  

E-Print Network [OSTI]

High field strength element/rare earth element fractionation during partial melting in the presence the amount of fractionation between the two decreases. In contrast, the heavy rare earth element partition field strength element/rare earth element fractionation during partial melting in the presence of garnet

van Westrenen, Wim

462

Comparisons of numerical modelling of the Selective Laser Melting Laurent VAN BELLE1, 2, a  

E-Print Network [OSTI]

and arc additive layer manufacturing (WAALM), laser metal deposition (LMD), selective laser melting (SLM laser melting (SLM) first developed for rapid prototyping (RP) is now used for rapid manufacturing is based upon a double meshing with a multi step birth and death technique of manufactured part

Paris-Sud XI, Université de

463

Investigation of residual stresses induced during the selective laser melting process  

E-Print Network [OSTI]

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

Paris-Sud XI, Université de

464

Sediment Melt-Migration Dynamics in Perennial Antarctic Lake Ice Steven M. Jepsen*  

E-Print Network [OSTI]

melting through laboratory ice at 22 uC in simulated summer conditions, with warmer ice producing faster boundaries was pronounced in laboratory ice warmer than 21 uC. This mechanism produced a flux of 0.1 g m22 hrSediment Melt-Migration Dynamics in Perennial Antarctic Lake Ice Steven M. Jepsen* Edward E. Adams

Priscu, John C.

465

Thirty-year history of glacier melting in the Nepal Himalayas Koji Fujita,1  

E-Print Network [OSTI]

Thirty-year history of glacier melting in the Nepal Himalayas Koji Fujita,1 Lonnie G. Thompson,2 of glacier melting in the Nepal Himalayas, J. Geophys. Res., 111, D03109, doi:10.1029/2005JD005894. 1. Introduction [2] Rapid shrinkage of glaciers in the Nepal Himalayas has been observed during recent decades [e

Howat, Ian M.

466

NOTES AND CORRESPONDENCE Surface Melting over Ice Shelves and Ice Sheets as Assessed from Modeled  

E-Print Network [OSTI]

NOTES AND CORRESPONDENCE Surface Melting over Ice Shelves and Ice Sheets as Assessed from Modeled of ice shelves and their progenitor ice sheets. To explore the magnitude of surface melt occurring over) and most of the Greenland Ice Sheet (GIS) by the year 2500. Capping CO2 concentrations at present

Meissner, Katrin Juliane

467

Molecular H2O as carrier for oxygen diffusion in hydrous silicate melts  

E-Print Network [OSTI]

Molecular H2O as carrier for oxygen diffusion in hydrous silicate melts H. Behrens a,, Y. Zhang b water is known to dramatically enhance oxygen diffusion in silicate melts, glasses and minerals in the diffusion of water and oxygen in silicates, Earth Planet. Sci. Lett., 103 (1991) 228­240.]. Here we report

Zhang, Youxue

468

Electrical structure beneath the northern MELT line on the East Pacific Rise at 15450  

E-Print Network [OSTI]

Electrical structure beneath the northern MELT line on the East Pacific Rise at 15°450 S Kiyoshi] The electrical structure of the upper mantle beneath the East Pacific Rise (EPR) at 15°450 S is imaged structure beneath the northern MELT line on the East Pacific Rise at 15°450 S, Geophys. Res. Lett., 33, L

Brest, Université de

469

Rare earth element partitioning between titanite and silicate melts: Henry's law revisited  

E-Print Network [OSTI]

Rare earth element partitioning between titanite and silicate melts: Henry's law revisited Stefan earth elements (REE) between titanite and a range of different silicate melts. Our results show. For geochemical modelling of magmatic processes involving titanite, and indeed other accessory phases

470

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

E-Print Network [OSTI]

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

Stixrude, Lars

471

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

SciTech Connect (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

472

Viscoelastic behavior of the cell wall of exfoliated graphite Po-Hsiu Chen, D.D.L. Chung *  

E-Print Network [OSTI]

the civil infrastructure, railroad, aircraft, satellites, automobiles, wind turbines, skis, washing machines * Composite Materials Research Laboratory, University at Buffalo, State University of New York, Buffalo, NY;graphite [12,13] and of continuous carbon fiber epoxy-matrix composites contain

Chung, Deborah D.L.

473

Chemical composition of the graphitic black carbon fraction in riverine and marine sediments at sub-micron scales  

E-Print Network [OSTI]

a closed loop in the carbon cycle Chemical composition of the graphitic black carbon fraction in riverine and marine sediments at sub-micron scales using carbon X-ray spectromicroscopy Paul R. Haberstroh a,*, Jay A. Brandes b , Yves Ge´linas c

Long, Bernard

474

doi:10.1016/S0016-7037(03)00463-0 Structural, chemical, and isotopic microanalytical investigations of graphite from  

E-Print Network [OSTI]

km/s (i.e., a few percent of the SN mass outflow speed). Energy dispersive X-ray spectrometry (EDXS electron microscopy (TEM) of ultramicrotome slices of these SN graphites revealed a high abundance (25 spectrometry (NanoSIMS) confirmed their presolar origin. In addition to TiCs, composite TiC/Fe grains (Ti

475

An Investigation of the Effect of Graphite Degradation on the Irreversible Capacity in Lithium-ion Cells  

SciTech Connect (OSTI)

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 (SEM) and Brunauer Emmett Teller (BET) measurements confirmed that Ar-ion sputtered Mag-10 electrodes display 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 un-altered anodes. Impedance spectroscopy and Fourier transform infrared (FTIR) spectroscopy on surface modified graphite anodes indicated the formation of a thicker and slightly more resistive SEI layer. Gas chromatography/mass spectroscopy (GC/MS) analysis of solvent extracts from the electrodes detected the presence of new compounds with M{sub w} on the order of 1600 g mol{sup -1} for the surface modified electrode with no evidence of elevated M{sub w} species for the unmodified electrode. The structural disorder induced in the graphite during long-term cycling maybe 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.

Stevenson, Cynthia; Hardwick, Laurence J.; Marcinek, Marek; Beer, Leanne; Kerr, John B.; Kostecki, Robert

2008-