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Note: This page contains sample records for the topic "involves iterative cycling" from the National Library of EnergyBeta (NLEBeta).
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1

Low cycle thermal fatigue testing of beryllium grades for ITER plasma facing components  

Science Conference Proceedings (OSTI)

A novel technique has been used to test the relative low cycle thermal fatigue resistance of different grades of US and Russian beryllium, which is proposed as plasma facing armor for fusion reactor first wall, limiter, and divertor components. The 30 kW electron beam test system at Sandia National Laboratories was used to sweep the beam spot along one direction at 1 Hz. This produces a localized temperature ``spike`` of 750{degree}C for each pass of the beam. Large thermal stresses in excess of the yield strength are generated due to very high spot heat flux, 250 MW/m{sup 2}. Cyclic plastic strains on the order of 0.6% produced visible cracking on the heated surface in less than 3000 cycles. An in-vacuo fiber optic borescope was used to visually inspect the beryllium surfaces for crack initiation. Grades of US beryllium tested included: S-65C, S- 65H, S-200F, S-200F-H, SR-200, I-400, extruded high purity, HIP`d spherical powder, porous beryllium (94% and 98% dense), Be/30% BeO, Be/60% BeO, and TiBe{sub 12}. Russian grades included: TGP-56, TShGT, DShG-200, and TShG-56. Both the number of cycles to crack initiation, and the depth of crack propagation, were measured. The most fatigue resistant grades were S-65C, DShG-200, TShGT, and TShG-56. Rolled sheet Be (SR-200) showed excellent crack propagation resistance in the plane of rolling, despite early formation of delamination cracks. Only one sample showed no evidence of surface melting, Extruded (T). Metallographic and chemical analyses are provided. Good agreement was found between the measured depth of cracks and a 2-D elastic-plastic finite element stress analysis.

Watson, R.D.; Youchison, D.L. [Sandia National Labs., Livermore, CA (United States); Dombrowski, D.E. [Brush Wellman, Inc., Cleveland, OH (United States); Guiniatouline, R.N. [Efremov Institute, (Russia); Kupriynov, I.B. [Russian Institute of Inorganic Materials (Russia)

1996-02-01T23:59:59.000Z

2

ElementNodeIterator  

Science Conference Proceedings (OSTI)

... iter=element->node_iterator(); !iter.end(); ++iter) { Node *node = iter.node(); // do something ... node returns a pointer to the iterator's current Node . ...

2013-08-23T23:59:59.000Z

3

Interruptible iterators  

E-Print Network (OSTI)

This paper introduces interruptible iterators, a language feature that makes expressive iteration abstractions much easier to implement. Iteration abstractions are valuable for software design, as shown by their frequent use in well-designed data structure libraries such as the Java Collections Framework. While Java iterators support iteration abstraction well from the standpoint of client code, they are awkward to implement correctly and efficiently, especially if the iterator needs to support imperative update of the underlying collection, such as removing the current element. Some languages, such as CLU and C # 2.0, support iteration through a limited coroutine mechanism, but these mechanisms do not support imperative updates. Interruptible iterators are more powerful coroutines in which the loop body is able to interrupt the iterator with requests to perform updates. Interrupts are similar to exceptions, but propagate differently and have resumption semantics. Interruptible iterators have been implemented as part of the JMatch programming language, an extended version of Java. A JMatch reimplementation of the Java Collections Framework shows that implementations can be made substantially shorter and simpler; performance results show that this language mechanism can also be implemented efficiently.

Jed Liu; Aaron Kimball; Andrew C. Myers

2006-01-01T23:59:59.000Z

4

The Iterate Manual  

E-Print Network (OSTI)

This is the manual for version 1.1 of Iterate, a powerful iteration macro for Common Lisp. Iterate is similar to Loop but provides numerous additional features, is well integrated with Lisp, and is extensible.

Amsterdam, Jonathan

1990-10-01T23:59:59.000Z

5

US ITER | ornl.gov  

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

US ITER Working with US ITER An unprecedented collaboration The international ITER fusion facility is now under construction in Cadarache, France Home | Science & Discovery | US...

6

On the progressive iteration approximation property and alternative iterations  

Science Conference Proceedings (OSTI)

This note revisits the progressive iteration approximation property and some recent modifications from the point of view of iterative methods for solving linear systems. In particular we show the connection with the classical Richardson iteration and ... Keywords: GMRES, Interpolation, Iterative methods, Progressive iteration approximation

J. M. Carnicer; J. Delgado; J. M. Peńa

2011-12-01T23:59:59.000Z

7

Iterative phase estimation  

E-Print Network (OSTI)

We give an iterative algorithm for phase estimation of a parameter theta, which is within a logarithmic factor of the Heisenberg limit. Unlike other methods, we do not need any entanglement or an extra rotation gate which can perform arbitrary rotations with almost perfect accuracy: only a single copy of the unitary channel and basic measurements are needed. Simulations show that the algorithm is successful. We also look at iterative phase estimation when depolarizing noise is present. It is seen that the algorithm is still successful provided the number of iterative stages is below a certain threshold.

Caleb J O'Loan

2009-04-22T23:59:59.000Z

8

What is ITER  

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

* Assumes 40% efficiency in the conversion of heat to electricity. Modern electric power plant*. 500 Million Watts 2,500 Million Watts 1975 1980 1995 ITER Demo PROGRESS IN...

9

Mechanisms Involved in the Amplification of the 11-yr Solar Cycle Signal in the Tropical Pacific Ocean  

Science Conference Proceedings (OSTI)

It is debated whether the response of the tropical Pacific Ocean to the 11-yr solar cycle forcing resembles a La Nińa– or El Nińo–like signal. To address this issue, ensemble simulations employing an atmospheric general circulation model with and ...

Stergios Misios; Hauke Schmidt

2012-07-01T23:59:59.000Z

10

Iterated multidimensional wave conversion  

Science Conference Proceedings (OSTI)

Mode conversion can occur repeatedly in a two-dimensional cavity (e.g., the poloidal cross section of an axisymmetric tokamak). We report on two novel concepts that allow for a complete and global visualization of the ray evolution under iterated conversions. First, iterated conversion is discussed in terms of ray-induced maps from the two-dimensional conversion surface to itself (which can be visualized in terms of three-dimensional rooms). Second, the two-dimensional conversion surface is shown to possess a symplectic structure derived from Dirac constraints associated with the two dispersion surfaces of the interacting waves.

Brizard, A. J. [Dept. Physics, Saint Michael's College, Colchester, VT 05439 (United States); Tracy, E. R.; Johnston, D. [Dept. Physics, College of William and Mary, Williamsburg, VA 23187-8795 (United States); Kaufman, A. N. [LBNL and Physics Dept., UC Berkeley, Berkeley, CA 94720 (United States); Richardson, A. S. [T-5, LANL, Los Alamos, NM 87545 (United States); Zobin, N. [Dept. Mathematics, College of William and Mary, Williamsburg, VA 23187-8795 (United States)

2011-12-23T23:59:59.000Z

11

The ITER Project: International Collaboration to Demonstrate...  

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

ITER Project: International Collaboration to Demonstrate Nuclear Fusion American Fusion News Category: U.S. ITER Link: The ITER Project: International Collaboration to Demonstrate...

12

Work stealing and persistence-based load balancers for iterative overdecomposed applications  

Science Conference Proceedings (OSTI)

Applications often involve iterative execution of identical or slowly evolving calculations. Such applications require incremental rebalancing to improve load balance across iterations. In this paper, we consider the design and evaluation of two distinct ... Keywords: dynamic load balancing, hierarchical load balancer, iterative applications, persistence, task scheduling, work stealing

Jonathan Lifflander; Sriram Krishnamoorthy; Laxmikant V. Kale

2012-06-01T23:59:59.000Z

13

Iterations of nonlinear entanglement witnesses  

E-Print Network (OSTI)

We describe a generic way to improve a given linear entanglement witness by a quadratic, nonlinear term. This method can be iterated, leading to a whole sequence of nonlinear witnesses, which become stronger in each step of the iteration. We show how to optimize this iteration with respect to a given state, and prove that in the limit of the iteration the nonlinear witness detects all states that can be detected by the positive map corresponding to the original linear witness.

Tobias Moroder; Otfried Gühne; Norbert Lütkenhaus

2008-06-04T23:59:59.000Z

14

Don't Loop, Iterate  

E-Print Network (OSTI)

I describe an iteration macro for Common Lisp that is clear, efficient, extensible, and in excellent taste.

Amsterdam, Jonathan

15

The physics role of ITER  

SciTech Connect

Experimental research on the International Thermonuclear Experimental Reactor (ITER) will go far beyond what is possible on present-day tokamaks to address new and challenging issues in the physics of reactor-like plasmas. First and foremost, experiments in ITER will explore the physics issues of burning plasmas--plasmas that are dominantly self-heated by alpha-particles created by the fusion reactions themselves. Such issues will include (i) new plasma-physical effects introduced by the presence within the plasma of an intense population of energetic alpha particles; (ii) the physics of magnetic confinement for a burning plasma, which will involve a complex interplay of transport, stability and an internal self-generated heat source; and (iii) the physics of very-long-pulse/steady-state burning plasmas, in which much of the plasma current is also self-generated and which will require effective control of plasma purity and plasma-wall interactions. Achieving and sustaining burning plasma regimes in a tokamak necessarily requires plasmas that are larger than those in present experiments and have higher energy content and power flow, as well as much longer pulse length. Accordingly, the experimental program on ITER will embrace the study of issues of plasma physics and plasma-materials interactions that are specific to a reactor-scale fusion experiment. Such issues will include (i) confinement physics for a tokamak in which, for the first time, the core-plasma and the edge-plasma are simultaneously in a reactor-like regime; (ii) phenomena arising during plasma transients, including so-called disruptions, in regimes of high plasma current and thermal energy; and (iii) physics of a radiative divertor designed for handling high power flow for long pulses, including novel plasma and atomic-physics effects as well as materials science of surfaces subject to intense plasma interaction. Experiments on ITER will be conducted by researchers in control rooms situated at major fusion laboratories around the world, linked by high-speed computer networks--thus extending further what is already a much-acclaimed paradigm for international collaboration in science.

Rutherford, P.H.

1997-04-01T23:59:59.000Z

16

8.2. Indices and Iterators  

Science Conference Proceedings (OSTI)

... handled identically. Every Field , Flux , and Equation class has a function iterator() which returns an IteratorP object. The ...

2013-08-23T23:59:59.000Z

17

Iterational retiming: Maximize iteration-level parallelism for nested loops  

E-Print Network (OSTI)

Nested loops are the most critical sections in many scientific and Digital Signal Processing (DSP) applications. It is important to study effective and efficient transformation techniques to increase parallelism for nested loops. In this paper, we propose a novel technique, iterational retiming, that can satisfy any given timing constraint by achieving full parallelism for iterations in a partition. Theorems and efficient algorithms are proposed for iterational retiming. The experimental results show that iterational retiming is a promising technique for parallel embedded systems. It can achieve 87% improvement over software pipelining and 88 % improvement over loop unfolding on average.

Chun Xue; Zili Shao; Meilin Liu; Edwin H. -m. Sha

2005-01-01T23:59:59.000Z

18

Iterative solution of differential equations  

E-Print Network (OSTI)

We discuss alternative iteration methods for differential equations. We provide a convergence proof for exactly solvable examples and show more convenient formulas for nontrivial problems.

Paolo Amore; Hakan Ciftci; Francisco M. Fernandez

2006-09-29T23:59:59.000Z

19

EU signs ITER deal Negotiations on the ITER international nuclear  

E-Print Network (OSTI)

Korea and the US, the agreement aims to develop a project that will test the feasibility of nuclearEU signs ITER deal Negotiations on the ITER international nuclear fusion project have been parties will contribute up to ten per cent. European Greens, fiercely opposed to nuclear energy, have

20

Princeton Plasma Physics Lab - ITER  

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

iter ITER is a large international iter ITER is a large international fusion experiment aimed at demonstrating the scientific and technological feasibility of fusion energy.ITER (Latin for "the way") will play a critical role advancing the worldwide availability of energy from fusion - the power source of the sun and the stars.To produce practical amounts of fusion power on earth, heavy forms of hydrogen are joined together at high temperature with an accompanying production of heat energy. The fuel must be held at a temperature of over 100 million degrees Celsius. At these high temperatures, the electrons are detached from the nuclei of the atoms, in a state of matter called plasma. en New imaging technique provides improved insight into controlling the plasma in fusion experiments

Note: This page contains sample records for the topic "involves iterative cycling" 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

US ITER Project Providing a Facility for  

E-Print Network (OSTI)

US ITER Project Providing a Facility for Burning Plasma Research Ned Sauthoff Project Manager, US to position the US for Burning Plasma Research #12;U.S. ITER / Sauthoff Slide 2 Structure of the Talk... ITER

22

ITER Central Solenoid Coil Insulation Qualification  

Science Conference Proceedings (OSTI)

An insulation system for ITER Central Solenoid must have sufficiently high electrical and structural strength. Design efforts to bring stresses in the turn and layer insulation within allowables failed. It turned out to be impossible to eliminate high local tensile stresses in the winding pack. When high local stresses can not be designed out, the qualification procedure requires verification of the acceptable structural and electrical strength by testing. We built two 4x4 arrays of the conductor jacket with two options of the CS insulation and subjected the arrays to 1.2 million compressive cycles at 60 MPa and at 76 K. Such conditions simulated stresses in the CS insulation. We performed voltage withstand tests and after end of cycling we measured the breakdown voltages between in the arrays. After that we dissectioned the arrays and studied micro cracks in the insulation. We report details of the specimens preparation, test procedures and test results.

Martovetsky, Nicolai N [ORNL; Mann Jr, Thomas Latta [ORNL; Miller, John L [ORNL; Freudenberg, Kevin D [ORNL; Reed, Richard P [Cryogenic Materials, Inc.; Walsh, Robert P [Florida State University; McColskey, J D [National Institute of Standards and Technology (NIST), Boulder; Evans, D [Advanced Cryogenic Materials

2010-01-01T23:59:59.000Z

23

ITER CENTRAL SOLENOID COIL INSULATION QUALIFICATION  

Science Conference Proceedings (OSTI)

An insulation system for ITER Central Solenoid must have sufficiently high electrical and structural strength. Design efforts to bring stresses in the turn and layer insulation within allowables failed. It turned out to be impossible to eliminate high local tensile stresses in the winding pack. When high local stresses can not be designed out, the qualification procedure requires verification of the acceptable structural and electrical strength by testing. We built two 4 x 4 arrays of the conductor jacket with two options of the CS insulation and subjected the arrays to 1.2 million compressive cycles at 60 MPa and at 76 K. Such conditions simulated stresses in the CS insulation. We performed voltage withstand tests and after end of cycling we measured the breakdown voltages between in the arrays. After that we dissectioned the arrays and studied micro cracks in the insulation. We report details of the specimens preparation, test procedures and test results.

Martovetsky, N N; Mann, T L; Miller, J R; Freudenberg, K D; Reed, R P; Walsh, R P; McColskey, J D; Evans, D

2009-06-11T23:59:59.000Z

24

Rotating Plasma Finding is Key for ITER  

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

Plasma Finding is Key for ITER Rotating Plasma Finding is Key for ITER PlasmaTurbulenceCSChang.png Tokamak turbulence showing inward-propagating streamers from normalized...

25

ITER CS Intermodule Support Structure  

Science Conference Proceedings (OSTI)

With five independently driven, bi-polarity power supplies, the modules of the ITER central solenoid (CS) can be energized in aligned or opposing field directions. This sets up the possibility for repelling modules, which indeed occurs, particularly between CS2L and CS3L around the End of Burn (EOB) time point. Light interface compression between these two modules at EOB and wide variations in these coil currents throughout the pulse produce a tendency for relative motion or slip. Ideally, the slip is purely radial as the modules breathe without any accumulative translational motion. In reality, however, asymmetries such as nonuniformity in intermodule friction, lateral loads from a plasma Vertical Disruption Event (VDE), magnetic forces from manufacturing and assembly tolerances, and earthquakes can all contribute to a combination of radial and lateral module motion. This paper presents 2D and 3D, nonlinear, ANSYS models which simulate these various asymmetries and determine the lateral forces which must be carried by the intermodule structure. Summing all of these asymmetric force contributions leads to a design-basis lateral load which is used in the design of various support concepts: the CS-CDR centering rings and a variation, the 2001 FDR baseline radial keys, and interlocking castles structures. Radial key-type intermodule structure interface slip and stresses are tracked through multiple 15 MA scenario current pulses to demonstrate stable motion following the first few cycles. Detractions and benefits of each candidate intermodule structure are discussed, leading to the simplest and most robust configuration which meets the design requirements: match-drilled radial holes and pin-shaped keys.

Myatt, R. [Myatt Consulting, Norfolk, MA; Freudenberg, Kevin D [ORNL

2011-01-01T23:59:59.000Z

26

ITER: Image Collections from the International Thermonuclear Experimental Reactor (ITER)  

DOE Data Explorer (OSTI)

ITER is a large-scale scientific experiment that aims to demonstrate that it is possible to produce commercial energy from fusion. The Q in the formula symbolizes the ratio of fusion power to input power. Q = 10 represents the scientific goal of the ITER project: to deliver ten times the power it consumes. From 50 MW of input power, the ITER machine is designed to produce 500 MW of fusion power - the first of all fusion experiments to produce net energy. During its operational lifetime, ITER will test key technologies necessary for the next step: the demonstration fusion power plant that will prove that it is possible to capture fusion energy for commercial use. The science going on at ITER - and all around the world in support of ITER - will benefit all of mankind. "We firmly believe that to harness fusion energy is the only way to reconcile huge conflicting demands which will confront humanity sooner or later. The issue at stake is how to reconcile the imperative, constantly growing demand of the majority of the world's population to raise their standard of living with the enormous environmental hazards resulting from the present energy supply. In our opinion, the use of fusion energy is a "must" if we want to be serious about embarking on sustainable development for future generations." Director-General Osamu Motojima, Opening address, Monaco International ITER Fusion Energy Days (MIIFED), 23 November 2010 [copied from http://www.iter.org/proj/itermission]. More than 900 images, organized into categories, are available as of 2013.

27

ITER Diagnostic First Wal  

Science Conference Proceedings (OSTI)

The ITER Diagnostic Division is responsible for designing and procuring the First Wall Blankets that are mounted on the vacuum vessel port plugs at both the upper and equatorial levels This paper will discuss the effects of the diagnostic aperture shape and configuration on the coolant circuit design. The DFW design is driven in large part by the need to conform the coolant arrangement to a wide variety of diagnostic apertures combined with the more severe heating conditions at the surface facing the plasma, the first wall. At the first wall, a radiant heat flux of 35W/cm2 combines with approximate peak volumetric heating rates of 8W/cm3 (equatorial ports) and 5W/cm3 (upper ports). Here at the FW, a fast thermal response is desirable and leads to a thin element between the heat flux and coolant. This requirement is opposed by the wish for a thicker FW element to accommodate surface erosion and other off-normal plasma events.

G. Douglas Loesser, et. al.

2012-09-21T23:59:59.000Z

28

A Reliable Technology to Manufacture the ITER Inner Vertical Target  

Science Conference Proceedings (OSTI)

Technical Paper / First Joint ITER-IAEA Technical Meeting on Analysis of ITER Materials and Technologies

Eliseo Visca; A. Pizzuto; B. Riccardi; S. Roccella; G. P. Sanguinetti

29

ITER Construction--Plant System Integration  

SciTech Connect

This brief paper introduces how the ITER will be built in the international collaboration. The ITER Organization plays a central role in constructing ITER and leading it into operation. Since most of the ITER components are to be provided in-kind from the member countries, integral project management should be scoped in advance of real work. Those include design, procurement, system assembly, testing, licensing and commissioning of ITER.

Tada, E. [ITER Organization Cadarache Center, 13108 St Paul lez Durance (France); Matsuda, S. [Japan Atomic Energy Research Agency, 100-0011, Chiyoda-ku, Tokyo (Japan)

2009-02-19T23:59:59.000Z

30

Chaotic iterations and topological chaos  

E-Print Network (OSTI)

Chaotic iterations have been introduced on the one hand by Chazan, Miranker [5] and Miellou [9] in a numerical analysis context, and on the other hand by Robert [11] and Pellegrin [10] in the discrete dynamical systems framework. In both cases, the objective was to derive conditions of convergence of such iterations to a fixed state. In this paper, a new point of view is presented, the goal here is to derive conditions under which chaotic iterations admit a chaotic behaviour in a rigorous mathematical sense. Contrary to what has been studied in the literature, convergence is not desired. More precisely, we establish in this paper a link between the concept of chaotic iterations on a finite set and the notion of topological chaos [8], [6], [7]. We are motivated by concrete applications of our approach, such as the use of chaotic boolean iterations in the computer security field. Indeed, the concept of chaos is used in many areas of data security without real rigorous theoretical foundations, and without using the fundamental properties that allow chaos. The wish of this paper is to bring a bit more mathematical rigour in this field.

Jacques M. Bahi; Christophe Guyeux

2008-10-17T23:59:59.000Z

31

Construction Safety Forecast for ITER  

SciTech Connect

The International Thermonuclear Experimental Reactor (ITER) project is poised to begin its construction activity. This paper gives an estimate of construction safety as if the experiment was being built in the United States. This estimate of construction injuries and potential fatalities serves as a useful forecast of what can be expected for construction of such a major facility in any country. These data should be considered by the ITER International Team as it plans for safety during the construction phase. Based on average U.S. construction rates, ITER may expect a lost workday case rate of < 4.0 and a fatality count of 0.5 to 0.9 persons per year.

cadwallader, lee charles

2006-11-01T23:59:59.000Z

32

The real mission of ITER  

DOE Green Energy (OSTI)

For future machines, the plasma stored energy is going up by factors of 20-40x, and plasma currents by 2-3x, while the surface to volume ratio is at the same time decreasing. Therefore the disruption forces, even for constant B, (which scale like IxB), and associated possible localized heating on machine components, are more severe. Notably, Tore Supra has demonstrated removal of more than 1 GJ of input energy, over nearly a 400 second period. However, the instantaneous stored energy in the Tore Supra system (which is most directly related to the potential for disruption damage) is quite small compared to other large tokamaks. The goal of ITER is routinely described as studying DT burning plasmas with a Q {approx} 10. In reality, ITER has a much more important first order mission. In fact, if it fails at this mission, the consequences are that ITER will never get to the eventual stated purpose of studying a burning plasma. The real mission of ITER is to study (and demonstrate successfully) plasma control with {approx}10-17 MA toroidal currents and {approx}100-400 MJ plasma stored energy levels in long-pulse scenarios. Before DT operation is ever given a go-ahead in ITER, the reality is that ITER must demonstrate routine and reliable control of high energy hydrogen (and deuterium) plasmas. The difficulty is that ITER must simultaneously deal with several technical problems: (1) heat removal at the plasma/wall interface, (2) protection of the wall components from off-normal events, and (3) generation of dust/redeposition of first wall materials. All previous tokamaks have encountered hundred's of major disruptions in the course of their operation. The consequences of a few MA of runaway electrons (at 20-50 MeV) being generated in ITER, and then being lost to the walls are simply catastrophic. They will not be deposited globally, but will drift out (up, down, whatever, depending on control system), and impact internal structures, unless 'ameliorated'. Basically, this represents an extraordinarily robust e-beam welding machine, capable of deep penetration into any armor tiles, to the cooling channels which are embedded less than 1 cm below the tile surface. When energy is deposited in a fraction of a second on (or in) a tile, the presence of underlying water cooling does no good for the purposes of heat removal.

Wurden, G A [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

33

An Iterative Rejection Sampling Method.  

E-Print Network (OSTI)

ar X iv :0 80 7. 28 23 v1 [ he p- ph ] 17 Ju l 2 00 8 Preprint typeset in JHEP style - HYPER VERSION Cavendish-HEP-08/10 An Iterative Rejection Sampling Method A. Sherstnev Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue... , Cambridge, CB3 0HE, UK and Scobeltsyn Institute of Nuclear Physics of Lomonosov Moscow State University, Moscow, Russia, 119992 (on leave) Abstract: In the note we consider an iterative generalisation of the rejection sampling method. In high energy physics...

Sherstnev, A

34

Neutronics at Wisconsin, ORNL advances ITER shielding and internationa...  

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

Neutronics at Wisconsin, ORNL advances ITER shielding and international collaboration American Fusion News Category: U.S. ITER Link: Neutronics at Wisconsin, ORNL advances ITER...

35

ITER movie created by Oak Ridge National Laboratory, National...  

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

ITER movie created by Oak Ridge National Laboratory, National Center for Computational Sciences American Fusion News Category: U.S. ITER Link: ITER movie created by Oak Ridge...

36

BBC Video Looks at ITER | Princeton Plasma Physics Lab  

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

Events Research Education Organization Contact Us BBC Video Looks at ITER American Fusion News Category: U.S. ITER Link: BBC Video Looks at ITER...

37

Iterative Time Reversal with Tunable Convergence  

E-Print Network (OSTI)

We propose and test an iterative technique for improving the temporal focusing of a time reversal mirror. A single amplification parameter is introduced to tune the convergence of the iteration. The tunable iterative technique is validated by tests on an experimental electromagnetic time reversal mirror, as well as on a novel numerical model.

Biniyam Tesfaye Taddese; Thomas M. Antonsen; Edward Ott; Steven M. Anlage

2011-07-07T23:59:59.000Z

38

Evaluating iterative optimization across 1000 datasets  

Science Conference Proceedings (OSTI)

While iterative optimization has become a popular compiler optimization approach, it is based on a premise which has never been truly evaluated: that it is possible to learn the best compiler optimizations across data sets. Up to now, most iterative ... Keywords: benchmarking, compiler optimization, iterative optimization

Yang Chen; Yuanjie Huang; Lieven Eeckhout; Grigori Fursin; Liang Peng; Olivier Temam; Chengyong Wu

2010-06-01T23:59:59.000Z

39

An Iterative Scheme for Valid Polynomial Inequality Generation in ...  

E-Print Network (OSTI)

Computational results for quadratic knapsack instances. Values in bold are optimal. Lasserre. DIGS n Optimal r obj. t(sec) Iter. 0 Iter. 1 Iter. 5 Iter. 10 t(sec). 5 370.

40

An Iterative Rejection Sampling Method  

E-Print Network (OSTI)

In the note we consider an iterative generalisation of the rejection sampling method. In high energy physics, this sampling is frequently used for event generation, i.e. preparation of phase space points distributed according to a matrix element squared $|M|^2$ for a scattering process. In many realistic cases $|M|^2$ is a complicated multi-dimensional function, so, the standard von Neumann procedure has quite low efficiency, even if an error reducing technique, like VEGAS, is applied. As a result of that, many of the $|M|^2$ calculations go to ``waste''. The considered iterative modification of the procedure can extract more ``unweighted'' events, i.e. distributed according to $|M|^2$. In several simple examples we show practical benefits of the technique and obtain more events than the standard von Neumann method, without any extra calculations of $|M|^2$.

A. Sherstnev

2008-07-17T23:59:59.000Z

Note: This page contains sample records for the topic "involves iterative cycling" 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

usion Technology for ITER, the ITER Project. Further Development Towards a DEMO Fusion Power Plant (4/4)  

E-Print Network (OSTI)

usion Technology for ITER, the ITER Project. Further Development Towards a DEMO Fusion Power Plant (4/4)

CERN. Geneva

2011-01-01T23:59:59.000Z

42

ITER Test Program: Key Technical Aspects  

Science Conference Proceedings (OSTI)

ITER / Proceedings of the Ninth Topical Meeting on the Technology of Fusion Energy (Oak Brook, Illinois, October 7-11, 1990)

Mohamed A. Abdou

43

Availability Requirement for ITER Plasma Parameter Measurements  

Science Conference Proceedings (OSTI)

ITER / Proceedings of the Twentieth Topical Meeting on the Technology of Fusion Energy (TOFE-2012) (Part 1), Nashville, Tennessee, August 27-31, 2012

K. Okayama; D. van Houtte; F. Sagot; M. Walsh

44

Improving robustness of ITER maintenance schedules.  

E-Print Network (OSTI)

?? In the experimental ITER fusion reactor, currently under construction in Cadarache, France, components close to the plasma will get activated and contaminated over time.… (more)

Schoen, Pepijn

2013-01-01T23:59:59.000Z

45

An overview of ITER diagnostics (invited)  

Science Conference Proceedings (OSTI)

The requirements for plasma measurements for operating and controlling the ITER device have now been determined. Initial criteria for the measurement quality have been set

Kenneth M. Young; A. E. Costley; Members of the ITER-JCT, ITER Home Teams and the ITER Diagnostics Expert Group

1997-01-01T23:59:59.000Z

46

Overview of ITER ProjectOverview of ITER Project --organizational structure,organizational structure,  

E-Print Network (OSTI)

/Research Plans 3. Basic Research in support of ITER · Experimental and Theoretical Plasma Research · R

47

Qualification of the Joints for the ITER Central Solenoid  

SciTech Connect

The ITER Central Solenoid has 36 interpancake joints, 12 bus joints, and 12 feeder joints in the magnet. The joints are required to have resistance below 4 nOhm at 45 kA at 4.5 K. The US ITER Project Office developed two different types of interpancake joints with some variations in details in order to find a better design, qualify the joints, and establish a fabrication process. We built and tested four samples of the sintered joints and two samples with butt-bonded joints (a total of eight joints). Both designs met the specifications. Results of the joint development, test results, and selection of the baseline design are presented and discussed in the paper. The ITER Central Solenoid (CS) consists of six modules. Each module is composed of six wound hexapancakes and one quadrapancake. The multipancakes are connected electrically and hydraulically by in-line interpancake joints. The joints are located at the outside diameter (OD) of the module. Cable in conduit conductor (CICC) high-current joints are critical elements in the CICC magnets. In addition to low resistivity, the CS joints must fit a space envelope equivalent to the regular conductor cross section and must have low hydraulic impedance and enough structural strength to withstand the hoop and compressive forces during operation, including cycling. This paper is the continuation of the work reported on the intermodule joints.

Martovetsky, N; Berryhill, A; Kenney, S

2011-09-01T23:59:59.000Z

48

Iterative Methods for Neutron Transport Eigenvalue Problems  

Science Conference Proceedings (OSTI)

We discuss iterative methods for computing criticality in nuclear reactors. In general this requires the solution of a generalized eigenvalue problem for an unsymmetric integro-differential operator in six independent variables, modeling transport, scattering, ... Keywords: criticality, generalized eigenvalue problem, inexact inverse iteration, neutron transport, symmetry

Fynn Scheben; Ivan G. Graham

2011-09-01T23:59:59.000Z

49

Nonlinear forecasting and iterated function systems  

Science Conference Proceedings (OSTI)

The theory of dynamical forecasting can be extended to iterated function systems. An unordered set of iterates may be sufficient to construct a simulation of the unknown dynamics. The underlying dynamical system may be nondeterministic: A random element may be allowed in the dynamics

Giorgio Mantica; B. G. Giraud

1992-01-01T23:59:59.000Z

50

Benchmarking ICRF simulations for ITER  

DOE Green Energy (OSTI)

Abstract Benchmarking of full-wave solvers for ICRF simulations is performed using plasma profiles and equilibria obtained from integrated self-consistent modeling predictions of four ITER plasmas. One is for a high performance baseline (5.3 T, 15 MA) DT H-mode plasma. The others are for half-field, half-current plasmas of interest for the pre-activation phase with bulk plasma ion species being either hydrogen or He4. The predicted profiles are used by seven groups to predict the ICRF electromagnetic fields and heating profiles. Approximate agreement is achieved for the predicted heating power partitions for the DT and He4 cases. Profiles of the heating powers and electromagnetic fields are compared.

R. V. Budny, L. Berry, R. Bilato, P. Bonoli, M. Brambilla, R.J. Dumont, A. Fukuyama, R. Harvey, E.F. Jaeger, E. Lerche, C.K. Phillips, V. Vdovin, J. Wright, and members of the ITPA-IOS

2010-09-28T23:59:59.000Z

51

Iterative equalization and decoding applied to underwater acoustic communication  

E-Print Network (OSTI)

absolute phase error versus iter- ation. (d) Number of bitCMP estimation are done iter- atively, in conjunction withAPP estimates ? (i) . If i = N iter , then the sym- bol APP

Sifferlen, James F.

2008-01-01T23:59:59.000Z

52

Testability of AND-EXOR Based Iterative Logic Arrays  

E-Print Network (OSTI)

Iterative Logic Arrays (ILAs) are ideal as VLSI sub-systems because of their regular structure and its close resemblance with FPGAs (Field Programmable Gate Arrays). AND-EXOR based circuits are of interest in the design of very low power circuits where energy loss implied by high frequency switching is of much consideration. This paper examines the testability of AND-EXOR based Iterative Logic Arrays (ILAs). For certain ILAs it is possible to find a test set whose size remains constant irrespective of the size of the ILA, while for others it varies with array size. Former type of ILAs is known as Constant-Testable (C-Testable). It has been shown that AND-EXOR based Logic Arrays are C-Testable and size of test set is equal to number of entries in cell truth table. The test generation problem has been shown to be related to certain properties of cycles in a set of graphs derived from cell truth table. By careful analysis of these cycles an efficient test generation technique that can be easily converted to an A...

Chakraborty, Avik

2008-01-01T23:59:59.000Z

53

iterative regularization in intensity-modulated radiation therapy ...  

E-Print Network (OSTI)

For iter* to be a meaningful parameter, the optimization solver should initially proceed ... When the optimization problem is ill-conditioned, iter* will be very small ...

54

International Workshop: MFE Roadmapping in the ITER Era | Princeton...  

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

International Workshop: MFE Roadmapping in the ITER Era International Workshop: MFE Roadmapping in the ITER Era Contact Information Website: International Workshop: MFE Roadmapping...

55

Iterators can be independent “from” their collections  

E-Print Network (OSTI)

External iterators pose problems for alias control mechanisms: they have access to collection interals and yet are not accessible from the collection; they may be used in contexts that are unaware of the collection. And yet iterators can benefit from alias control because iterators may fail “unexpectedly ” when their collections are modified. We explain a novel aliasing annotation “from ” that indicates when a collection intends to delegate its access to internals to a new object and how it can be given semantics using a fractional permission system. We sketch how a static analysis using permissions can statically detect possible concurrent modification exceptions. 1.

John Boyland

2007-01-01T23:59:59.000Z

56

Fabrication Preparation of ITER Vacuum Vessel - Material Considerations, Regulatory Requirements, and Fabrication Plans  

Science Conference Proceedings (OSTI)

Technical Paper / First Joint ITER-IAEA Technical Meeting on Analysis of ITER Materials and Technologies

K. Ioki; C. H. Choi; E. Daly; S. Dani; J. Davis; B. Giraud; C. Hamlyn-Harris; G. Johnson; L. Jones; C. Jun; B. C. Kim; E. Kuzmin; R. Le Barbier; J-M. Martinez; H. Pathak; J. Preble; J. Reich; J. W. Sa; A. Terasawa; Yu. Utin; X. Wang; S. Wu

57

The Development of Material and Fabrication Technologies for ITER Magnet Supports  

Science Conference Proceedings (OSTI)

Technical Paper / First Joint ITER-IAEA Technical Meeting on Analysis of ITER Materials and Technologies

P. Y. Li; C. J. Pan; B. L. Hou; S. L. Han; Z. C. Sun; F. Savary; Y. K. Fu; R. Gallix; N. Mitchell

58

Investigations of Radiation Damage Effects on ITER Structural and Plasma-Facing Materials  

Science Conference Proceedings (OSTI)

Technical Paper / First Joint ITER-IAEA Technical Meeting on Analysis of ITER Materials and Technologies

A. I. Ryazanov; V. S. Koidan; B. I. Khripunov; S. T. Latushkin; V. B. Petrov; L. S. Danelyan; E. V. Semenov; V. N. Unezhev

59

Analyses and Preliminary Results of an Updated ITER Radioactive Waste Assessment  

Science Conference Proceedings (OSTI)

Technical Paper / First Joint ITER-IAEA Technical Meeting on Analysis of ITER Materials and Technologies

S. Zheng; R. Pampin; S. Lilley; B. C. Na; M. J. Loughlin; N. P. Taylor; V. Barabash

60

Iterated Differential Forms II: Riemannian Geometry Revisited  

E-Print Network (OSTI)

A natural extension of Riemannian geometry to a much wider context is presented on the basis of the iterated differential form formalism developed in math.DG/0605113 and an application to general relativity is given.

A. M. Vinogradov; L. Vitagliano

2006-09-11T23:59:59.000Z

Note: This page contains sample records for the topic "involves iterative cycling" 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

Iterated maps for clarinet-like systems  

E-Print Network (OSTI)

The dynamical equations of clarinet-like systems are known to be reducible to a non-linear iterated map within reasonable approximations. This leads to time oscillations that are represented by square signals, analogous to the Raman regime for string instruments. In this article, we study in more detail the properties of the corresponding non-linear iterations, with emphasis on the geometrical constructions that can be used to classify the various solutions (for instance with or without reed beating) as well as on the periodicity windows that occur within the chaotic region. In particular, we find a regime where period tripling occurs and examine the conditions for intermittency. We also show that, while the direct observation of the iteration function does not reveal much on the oscillation regime of the instrument, the graph of the high order iterates directly gives visible information on the oscillation regime (characterization of the number of period doubligs, chaotic behaviour, etc.).

Pierre-André Taillard; Jean Kergomard; Franck Laloë

2009-12-12T23:59:59.000Z

62

Iterative and Incremental Development: A Brief History  

Science Conference Proceedings (OSTI)

Although many view iterative and incremental development as a modern practice, its application dates as far back as the mid-1950s. Prominent software-engineering thought leaders from each succeeding decade supported IID practices, and many large projects ...

Craig Larman; Victor R. Basili

2003-06-01T23:59:59.000Z

63

Michel Claessens michel.claessens@iter.org  

E-Print Network (OSTI)

on the manufacturing of critical components, were among the important issues discussed at the eighth meeting. Photos of the Council Meeting can be found at: http://www.iter.org/gallery/pr_2011_06_ic8 Additional

64

French landmark decree authorizes ITER construction | Princeton...  

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

ITER construction By John Greenwald November 20, 2012 Tweet Widget Facebook Like Google Plus One The French government has capped more than two years of review by issuing a...

65

Iterative entanglement distillation for finite resources  

E-Print Network (OSTI)

We discuss a specific entanglement distillation scheme under the constraint of finite samples of entangled qubit pairs. It is shown that an iterative process can be explicitly formulated. The average fidelity of this process can be enhanced by introducing conditional storing of entangled qubit pairs in each step of the iteration. We investigate the corresponding limitations on the size and the initial fidelity of the sample.

Stefan Probst-Schendzielorz; Thorsten Bschorr; Matthias Freyberger

2005-06-20T23:59:59.000Z

66

Adaptive iterative multiscale finite volume method  

Science Conference Proceedings (OSTI)

The multiscale finite volume (MSFV) method is a computationally efficient numerical method for the solution of elliptic and parabolic problems with heterogeneous coefficients. It has been shown for a wide range of test cases that the MSFV results are ... Keywords: Adaptive multiscale method, Elliptic problem, Infrequently localization improvement, Iterative multiscale finite-volume method, Iterative multiscale method, Multiphase flow, Multiscale finite-volume method, Multiscale method, Porous media

Hadi Hajibeygi; Patrick Jenny

2011-02-01T23:59:59.000Z

67

Characterization of Plasma Sprayed Beryllium ITER First Wall Mockups  

Science Conference Proceedings (OSTI)

ITER first wall beryllium mockups, which were fabricated by vacuum plasma spraying the beryllium armor, have survived 3000 thermal fatigue cycles at 1 MW/sq m without damage during high heat flux testing at the Plasma Materials Test Facility at Sandia National Laboratory in New Mexico. The thermal and mechanical properties of the plasma sprayed beryllium armor have been characterized. Results are reported on the chemical composition of the beryllium armor in the as-deposited condition, the through thickness and normal to the through thickness thermal conductivity and thermal expansion, the four-point bend flexure strength and edge-notch fracture toughness of the beryllium armor, the bond strength between the beryllium armor and the underlying heat sink material, and ultrasonic C-scans of the Be/heat sink interface.

Castro, Richard G.; Vaidya, Rajendra U.; Hollis, Kendall J.

1997-12-31T23:59:59.000Z

68

PPPL--2702 Power Radiated from ITER  

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

702 702 " Power Radiated from ITER and CIT by Impurities D E ~ O 014715 J. Cummings, S. A. Cohen, R Hulse, D. E. Post, M. H. Redi and J. Perkinst Princeton Plasma Physics Laboratory Princeton University, Rinceton, NJ 08543 Abstract The MIST code has been used to model impurity radiation from the edge and core plasmas in ITER and CIT. A broad range of parameters have been varied, including Zeff, impurity species, impurity transport coefficients, and plasma temperature and density profiles, especially at the edge. For a set of these parameters representative of the baseline ITER ignition scenario, it is seen that impurity radiation, which is produced in roughly equal amounts by the edge and core regions, can make a major improvement in divertor operation without compromising core

69

Non-iterative and exact method for constraining particles in a linear geometry  

E-Print Network (OSTI)

We present a practical numerical method for evaluating the Lagrange multipliers necessary for maintaining a constrained linear geometry of particles in dynamical simulations. The method involves no iterations, and is limited in accuracy only by the numerical methods for solving small systems of linear equations. As a result of the non-iterative and exact (within numerical accuracy) nature of the procedure there is no drift in the constrained geometry, and the method is therefore readily applied to molecular dynamics simulations of, e.g., rigid linear molecules or materials of non-spherical grains. We illustrate the approach through implementation in the commonly used second-order velocity explicit Verlet method.

Horacio Tapia-McClung; Niels Grřnbech-Jensen

2004-12-21T23:59:59.000Z

70

Feasibility Study of Lost-Alpha-Particle Measurements by Probe Technique in ITER  

Science Conference Proceedings (OSTI)

Technical Paper by Monaco ITER Postdoctoral Fellows / First Joint ITER-IAEA Technical Meeting on Analysis of ITER Materials and Technologies

E. A. Veshchev; L. Bertalot; S. Putvinski; M. Garcia-Munoz; S. W. Lisgo; C. S. Pitcher; R. A. Pitts; V. S. Udintsev; M. Walsh

71

Plasma-Wall-Interaction Diagnostics in ITER: Dust, Erosion, and Tritium Retention  

Science Conference Proceedings (OSTI)

Technical Paper by Monaco ITER Postdoctoral Fellows / First Joint ITER-IAEA Technical Meeting on Analysis of ITER Materials and Technologies

Junghee Kim; P. Andrew; R. Reichle

72

US ITER is a strong contributor in plan to enhance international...  

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

American Fusion News Category: U.S. ITER Link: US ITER is a strong contributor in plan to enhance international sharing of prime ITER real estate...

73

Joint News Release ELEVENTH ITER NEGOTIATIONS MEETING  

E-Print Network (OSTI)

Joint News Release ELEVENTH ITER NEGOTIATIONS MEETING CHENGDU , CHINA, 24OCTOBER 2005 Delegations of America met in CHENGDU on 24October 2005 to continue their work to reach agreement on the joint the project and its procurements, and the continuing joint drafting of the agreement on establishing

74

The ITER budget is projected to be  

E-Print Network (OSTI)

, including 4.7 billion euros to build the reactor. BACK FRANCE AND JAPAN FAIL TO RESOLVE ROW ON NUCLEAR to resolve their differences on where to build a revolutionary nuclear fusion project, with Foreign Minister Experimental Reactor (ITER) in France without Japan if an agreement with Tokyo is not reached "as soon

75

ITERATIVE METHODS FOR NEUTRON TRANSPORT EIGENVALUE PROBLEMS  

E-Print Network (OSTI)

Abstract. We discuss iterative methods for computing criticality in nuclear reactors. In general the safety and optimal performance of existing nuclear reactors is an important task of great environmental significance. When operating a nuclear reactor, the engineer seeks to achieve a sustainable chain reaction

Graham, Ivan

76

Iterated local search in nurse rostering problem  

Science Conference Proceedings (OSTI)

This paper presents how to solve a nurse rostering problem over the real datasets of Centre hospitalier régional de Trois-Rivičres hospital in Canada. Due to the complexity of this problem with plenty of hard constraints, we propose an ... Keywords: greedy, iterated local search, nurse rostering, tabu search

Sen Ngoc Vu, Minh H. Nhat Nguyen, Le Minh Duc, Chantal Baril, Viviane Gascon, Tien Ba Dinh

2013-12-01T23:59:59.000Z

77

Optimizing ITER Power Supplies Operation Through RAMI and Standardization  

Science Conference Proceedings (OSTI)

ITER Systems / Proceedings of the Nineteenth Topical Meeting on the Technology of Fusion Energy (TOFE) (Part 1)

François Sagot; Didier van Houtte; Katsumi Okayama; Joel Hourtoule; Inho Song

78

Budget Planning Meeting FY 2007 Status of ITER Negotiations  

E-Print Network (OSTI)

March 22-24 · CDs-2-4 are more dependent upon the reviews by the ITER Organization (to be formed-level discussion on ITER held in DOE HQ, Washington, DC · Requested a comprehensive briefing on ITER #12;FY2006 Agreement per H.R. 610 Form ITER Organization Begin funding for personnel FY2006 Pres Request of $49.5M

79

Optimization Online - "Block-Iterative and String-Averaging ...  

E-Print Network (OSTI)

Jul 19, 2009 ... Optimization Online. "Block-Iterative and String-Averaging Projection Algorithms in Proton Computed Tomography Image Reconstruction".

80

Specifying java iterators with JML and Esc/Java2  

Science Conference Proceedings (OSTI)

The 2006 SAVCBS Workshop has posed a Challenge Problem on the topic of specifying iterators. This note provides a specification in the Java Modeling Language (JML) [1, 2] for the Java interfaces Iterator and Iterable that captures the interactions ... Keywords: ESC/Java2, JML, specification, static analysis, verification

David R. Cok

2006-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "involves iterative cycling" 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

Princeton Plasma Physics Lab - U.S. ITER  

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

iter U.S. ITER en BBC iter U.S. ITER en BBC Video Looks at ITER http://www.pppl.gov/node/1536

American Fusion News Category: 
iter">U.S. ITER
82

Technological Institute of Renewable Energy ITER | Open Energy Information  

Open Energy Info (EERE)

Renewable Energy ITER Renewable Energy ITER Jump to: navigation, search Name Technological Institute of Renewable Energy (ITER) Place Santa Cruz de Tenerife, Spain Zip 38611 Sector Solar, Wind energy Product Spain-based, technological research and development institute focused on the solar and wind sectors. References Technological Institute of Renewable Energy (ITER)[1] LinkedIn Connections CrunchBase Profile No CrunchBase profile. Create one now! This article is a stub. You can help OpenEI by expanding it. Technological Institute of Renewable Energy (ITER) is a company located in Santa Cruz de Tenerife, Spain . References ↑ "Technological Institute of Renewable Energy (ITER)" Retrieved from "http://en.openei.org/w/index.php?title=Technological_Institute_of_Renewable_Energy_ITER&oldid=352069

83

Iterated dynamical maps in an ion trap  

E-Print Network (OSTI)

Iterated dynamical maps offer an ideal setting to investigate quantum dynamical bifurcations and are well adapted to few-qubit quantum computer realisations. We show that a single trapped ion, subject to periodic impulsive forces, exhibits a rich structure of dynamical bifurcations derived from the Jahn-Teller Hamiltonian flow model. We show that the entanglement between the oscillator and electronic degrees of freedom reflects the underlying dynamical bifurcation in a Floquet eigenstate.

M. Duncan; J. Links; G. J. Milburn

2007-11-16T23:59:59.000Z

84

Shortcuts to adiabaticity by superadiabatic iterations  

E-Print Network (OSTI)

Different techniques to speed up quantum adiabatic processes are currently being explored for applications in atomic, molecular and optical physics, such as transport, cooling and expansions, wavepacket splitting, or internal state control. Here we examine the capabilities of superadiabatic iterations to produce a sequence of shortcuts to adiabaticity. The general formalism is worked out as well as examples for population inversion in a two-level system.

S. Ibáńez; Xi Chen; J. G. Muga

2012-12-27T23:59:59.000Z

85

Iterative solutions to the Dirac equation  

E-Print Network (OSTI)

We consider a single particle which is bound by a central potential and obeys the Dirac equation in d dimensions. We first apply the asymptotic iteration method to recover the known exact solutions for the pure Coulomb case. For a screened-Coulomb potential and for a Coulomb plus linear potential with linear scalar confinement, the method is used to obtain accurate approximate solutions for both eigenvalues and wave functions.

Hakan Ciftci; Richard L. Hall; Nasser Saad

2005-05-26T23:59:59.000Z

86

Cryogenic Viscous Compressor Development and Modeling for the ITER Vacuum System  

SciTech Connect

The ITER vacuum system requires a roughing pump system that can pump the exhaust gas from the torus cryopumps to the tritium exhaust processing plant. The gas will have a high tritium content and therefore conventional vacuum pumps are not suitable. A pump called a cryogenic viscous compressor (CVC) is being designed for the roughing system to pump from ~500 Pa to 10 Pa at flow rates of 200 Pa-m3/ s. A unique feature of this pump is that is allows any helium in the gas to flow through the pump where it is sent to the detritiation system before exhausting to atmosphere. A small scale prototype of the CVC is being tested for heat transfer characteristics and compared to modeling results to ensure reliable operation of the full scale CVC. Keywords- ITER; vacuum; fuel cycle

Baylor, Larry R [ORNL; Meitner, Steven J [ORNL; Barbier, Charlotte N [ORNL; Combs, Stephen Kirk [ORNL; Duckworth, Robert C [ORNL; Edgemon, Timothy D [ORNL; Rasmussen, David A [ORNL; Hechler, Michael P [ORNL; Kersevan, R. [ITER Organization, Cadarache, France; Dremel, M. [General Atomics, San Diego; Pearce, R.J.H. [General Atomics, San Diego; Boissin, Jean Claude [Consultant

2011-01-01T23:59:59.000Z

87

Testing and modeling of diffusion bonded prototype optical windows under ITER conditions  

SciTech Connect

Glass-metal joints are a part of ITER optical diagnostics windows. These joints must be leak tight for the safety (presence of tritium in ITER) and to preserve the vacuum. They must also withstand the ITER environment: temperatures up to 220 deg.C and fast neutron fluxes of {approx}3.10{sup 9} n/cm{sup 2}.s. At the moment, little information is available about glass-metal joints suitable for ITER. Therefore, we performed mechanical and thermal tests on some prototypes of an aluminium diffusion bonded optical window. Finite element modeling with Abaqus code was used to understand the experimental results. The prototypes were helium leaking probably due to very tiny cracks in the interaction layer between the steel and the aluminium. However, they were all able to withstand a thermal cycling test up to 200 deg. C; no damage could be seen after the tests by visual inspection. The prototypes successfully passed push-out test with a 500 N load. During the destructive push-out tests the prototypes broke at a 6-12 kN load between the aluminium layer and the steel or the glass, depending on the surface quality of the glass. The microanalysis of the joints has also been performed. The finite element modeling of the push-out tests is in a reasonable agreement with the experiments. According to the model, the highest thermal stress is created in the aluminium layer. Thus, the aluminium joint seems to be the weakest part of the prototypes. If this layer is improved, it will probably make the prototype helium leak tight and as such, a good ITER window candidate. (authors)

Jacobs, M. [Flemish Inst. for Technological Research, Mol (Belgium); Van Oost, G. [Dept. of Applied Physics, Ghent Univ., Ghent (Belgium); Degrieck, J.; De Baere, I. [Dept. of Materials Science and Engineering, Ghent Univ., Ghent (Belgium); Gusarov, A. [Belgian Nuclear Research Center, Mol (Belgium); Gubbels, F. [TNO, Eindhoven (Netherlands); Massaut, V. [Belgian Nuclear Research Center, Mol (Belgium)

2011-07-01T23:59:59.000Z

88

The Energy Strategy Cycle  

E-Print Network (OSTI)

Effective long-range energy planning begins with a reflective analysis that encompasses the complexity of today's energy reality and sets a course for activity to achieve long-range continuing advancement. This strategy approach involves an interrelated 'cycle' that once started and controlled in the proper direction is almost self-building in improvement. Energy conservation is the driving force to create additive progress involving system flexibility, process integration, and less energy dependence.

Korich, R. D.

1983-01-01T23:59:59.000Z

89

Evaluation of ITER MSE Viewing Optics  

Science Conference Proceedings (OSTI)

The Motional Stark Effect (MSE) diagnostic on ITER determines the local plasma current density by measuring the polarization angle of light resulting from the interaction of a high energy neutral heating beam and the tokamak plasma. This light signal has to be transmitted from the edge and core of the plasma to a polarization analyzer located in the port plug. The optical system should either preserve the polarization information, or it should be possible to reliably calibrate any changes induced by the optics. This LLNL Work for Others project for the US ITER Project Office (USIPO) is focused on the design of the viewing optics for both the edge and core MSE systems. Several design constraints were considered, including: image quality, lack of polarization aberrations, ease of construction and cost of mirrors, neutron shielding, and geometric layout in the equatorial port plugs. The edge MSE optics are located in ITER equatorial port 3 and view Heating Beam 5, and the core system is located in equatorial port 1 viewing heating beam 4. The current work is an extension of previous preliminary design work completed by the ITER central team (ITER resources were not available to complete a detailed optimization of this system, and then the MSE was assigned to the US). The optimization of the optical systems at this level was done with the ZEMAX optical ray tracing code. The final LLNL designs decreased the ''blur'' in the optical system by nearly an order of magnitude, and the polarization blur was reduced by a factor of 3. The mirror sizes were reduced with an estimated cost savings of a factor of 3. The throughput of the system was greater than or equal to the previous ITER design. It was found that optical ray tracing was necessary to accurately measure the throughput. Metal mirrors, while they can introduce polarization aberrations, were used close to the plasma because of the anticipated high heat, particle, and neutron loads. These mirrors formed an intermediate image that then was relayed out of the port plug with more ideal (dielectric) mirrors. Engineering models of the optics, port plug, and neutral beam geometry were also created, using the CATIA ITER models. Two video conference calls with the USIPO provided valuable design guidelines, such as the minimum distance of the first optic from the plasma. A second focus of the project was the calibration of the system. Several different techniques are proposed, both before and during plasma operation. Fixed and rotatable polarizers would be used to characterize the system in the no-plasma case. Obtaining the full modulation spectrum from the polarization analyzer allows measurement of polarization effects and also MHD plasma phenomena. Light from neutral beam interaction with deuterium gas (no plasma) has been found useful to determine the wavelength of each spatial channel. The status of the optical design for the edge (upper) and core (lower) systems is included in the following figure. Several issues should be addressed by a follow-on study, including whether the optical labyrinth has sufficient neutron shielding and a detailed polarization characterization of actual mirrors.

Allen, S; Lerner, S; Morris, K; Jayakumar, J; Holcomb, C; Makowski, M; Latkowski, J; Chipman, R

2007-03-26T23:59:59.000Z

90

Final Report on ITER Task Agreement 81-08  

Science Conference Proceedings (OSTI)

As part of an ITER Implementing Task Agreement (ITA) between the ITER US Participant Team (PT) and the ITER International Team (IT), the INL Fusion Safety Program was tasked to provide the ITER IT with upgrades to the fusion version of the MELCOR 1.8.5 code including a beryllium dust oxidation model. The purpose of this model is to allow the ITER IT to investigate hydrogen production from beryllium dust layers on hot surfaces inside the ITER vacuum vessel (VV) during in-vessel loss-of-cooling accidents (LOCAs). Also included in the ITER ITA was a task to construct a RELAP5/ATHENA model of the ITER divertor cooling loop to model the draining of the loop during a large ex-vessel pipe break followed by an in-vessel divertor break and compare the results to a simular MELCOR model developed by the ITER IT. This report, which is the final report for this agreement, documents the completion of the work scope under this ITER TA, designated as TA 81-08.

Richard L. Moore

2008-03-01T23:59:59.000Z

91

The Carbon Cycle  

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

The Carbon Cycle The Carbon Cycle The global carbon cycle involves the carbon in and exchanging between the earth's atmosphere, fossil fuels, the oceans, and the vegetation and soils of the earth's terrestrial ecosystems. image Each year, the world's terrestrial ecosystems withdraw carbon from the atmosphere through photosynthesis and add it again through respiration and decay. A more detailed look at the global carbon cycle for the 1990s is shown below. The main annual fluxes in GtC yr-1 are: pre-industrial "natural" fluxes in black and "anthropogenic" fluxes in red (modified from Sarmiento and Gruber, 2006, with changes in pool sizes from Sabine et al., 2004a). The net terrestrial loss of -39 GtC is inferred from cumulative fossil fuel emissions minus atmospheric increase minus ocean storage. The loss of

92

Iterative Collision Resolution in Wireless Networks  

E-Print Network (OSTI)

With the growing popularity of smart phones and tablets, development of multimedia applications is on the rise. Speedy transmission of this massive amount information is already pushing the limits of the capacity of wireless networks, and in upcoming years wireless data traffic is projected to continue increasing dramatically. Advances in wireless network throughput are necessary to keep up with society’s data demands. In an uncoordinated wireless communications system, transmissions collide and interfere as multiple users transmit data to a central receiver. Slotted-ALOHA, the conventional method that schedules user transmissions, has only 37% throughput efficiency. However, theoretical results in recent studies suggest that scheduling transmissions over a number of random, fixed timeslots and employing iterative collision resolution techniques achieves optimal throughput efficiency of approximately 100%. This research considers how real-world conditions affect these theoretical results. A MATLAB model was developed create random graphs, representing users transmitting packets over such timeslots, and the packets were resolved by this method. This model was simulated extensively, representing networks of up to 10,000 users over 10,000 to 15,000 timeslots, and the number of packets resolved in each iteration was measured. These simulations have generated empirical data that backs up the theoretical claim. The distribution of the number of packets resolved also led to modifications of the current model to increase the percentage of packets resolved in each iteration. Furthermore, by investigating low density parity check coding techniques, other modifications to the current model can optimize the throughput over several consecutive transmissions where unresolved packets are resent with higher probability of recovery. These results demonstrate the potential of this method in handling uncoordinated transmissions in communications systems, even in the presence of finite conditions. This suggests that this method could eventually be employed in actual wireless systems.

Stuckman, Katherine Christine

2013-05-01T23:59:59.000Z

93

The role of heating and current drive in ITER  

SciTech Connect

This report discusses and summarize the role of heating and non-inductive current drive in ITER as: (1) ITER must have heating power sufficient for ignition. (2) The heating system must be capable of current drive. (3) Steady-state operation is an ``ultimate goal.`` It is recognized that additional heating and current drive power (beyond what is initially installed on ITER) may be required. (4) The ``Ultimate goal of steady-state operation`` means steady-state with Q{sub CD} {ge} 5. Unlike the ``Terms of Reference`` for the ITER CDA, the ``ITER Technical Objectives and Approaches`` for the EDA sets no goal for the neutron wall load during steady-state operation. (5) In addition to bulk current drive, the ITER heating and current drive system should be used for current profile control and for burn control.

Nevins, W.M.; Haney, S.

1993-10-18T23:59:59.000Z

94

International Workshop: MFE Roadmapping in the ITER Era | Princeton...  

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

Princeton University Princeton, NJ International Workshop: MFE Roadmapping in the ITER Era Princeton University Princeton, NJ Host: G.H. Neilson Coordinator: Pamela Hampton...

95

Progress in the Safety and Licensing of ITER  

Science Conference Proceedings (OSTI)

ITER / Proceedings of the Twentieth Topical Meeting on the Technology of Fusion Energy (TOFE-2012) (Part 1), Nashville, Tennessee, August 27-31, 2012

Neill Taylor; Carlos Alejaldre; Pierre Cortes

96

Extrapolation and Local Acceleration of an Iterative Process for ...  

E-Print Network (OSTI)

Apr 19, 2012 ... Abstract: We consider sequential iterative processes for the common fixed point problem of families of cutter operators on a Hilbert space.

97

Port-Based Plasma Diagnostic Infrastructure on ITER  

Science Conference Proceedings (OSTI)

ITER / Proceedings of the Twentieth Topical Meeting on the Technology of Fusion Energy (TOFE-2012) (Part 1), Nashville, Tennessee, August 27-31, 2012

C. S. Pitcher et al.

98

Optimization Online - On the use of iterative methods in cubic ...  

E-Print Network (OSTI)

Sep 11, 2013 ... On the use of iterative methods in cubic regularization for unconstrained optimization. Tommaso Bianconcini (tommaso.bianconcini ***at*** ...

99

ITER CS Conductor Helium Inlet Design Optimization and Evaluation  

Science Conference Proceedings (OSTI)

ITER / Proceedings of the Twentieth Topical Meeting on the Technology of Fusion Energy (TOFE-2012) (Part 1), Nashville, Tennessee, August 27-31, 2012

R. Leonard Myatt; Nicolai N. Martovetsky; Charlotte Barbier; Kevin D. Freudenberg

100

A synopsis of collective alpha effects and implications for ITER  

SciTech Connect

This paper discusses the following: Alpha Interaction with Toroidal Alfven Eigenmodes; Alpha Interaction with Ballooning Modes; Alpha Interaction with Fishbone Oscillations; and Implications for ITER.

Sigmar, D.J.

1990-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "involves iterative cycling" 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

President Bush Issues Executive Order Designating ITER International...  

Office of Science (SC) Website

to join counterparts from China, the European Union, India, Japan, the Republic of Korea and the Russian Federation at the organization's first meeting of the ITER Council in...

102

ITER Central Solenoid support structure analysis  

Science Conference Proceedings (OSTI)

The ITER Central Solenoid (CS) is comprised of six independent coils held together by a pre-compression support structure. This structure must provide enough preload to maintain sufficient coil-to-coil contact and interface load throughout the current pulse. End of burn (EOB) represents one of the most extreme time-points doing the reference scenario when the currents in the CS3 coils oppose those of CS1 & CS2. The CS structure is performance limited by the room temperature static yield requirements needed to support the roughly 180 MN preload to resist coil separation during operation. This preload is applied by inner and external tie plates along the length of the coil stack by mechanical fastening methods utilizing Superbolt technology. The preloading structure satisfies the magnet structural design criteria of ITER and will be verified during mockup studies. The solenoid is supported from the bottom of the toroidal field (TF) coil casing in both the vertical radial directions. The upper support of the CS coil structure maintains radial registration with the TF coil in the event of vertical disruptions (VDE) loads and earthquakes. All of these structure systems are analyzed via a global finite element analysis (FEA). The model includes a complete sector of the TF coil and the CS coil/structure in one self-consistent analysis. The corresponding results and design descriptions are described in this report.

Freudenberg, Kevin D [ORNL; Myatt, R. [Myatt Consulting, Norfolk, MA

2011-01-01T23:59:59.000Z

103

A new iterative approach to solving the transport equation  

E-Print Network (OSTI)

We present a new iterative approach to solving neutral-particle transport problems. The scheme divides the transport solution into its particular and homogeneous or “source-free” components. The particular problem is solved directly, while the homogeneous problem is found iteratively. To organize the iterative inversion of the homogeneous components, we exploit the structures of the so called Case-modes that compose it. The asymptotic Case-modes, those that vary slowly in space and angle, are assigned to a diffusion solver. The remaining transient Case-modes, those with large spatial gradients, are assigned to a transport solver. The scheme iterates on the contribution from each solver until the particular plus homogeneous solution converges. The iterative method is implemented successfully in slab geometry with isotropic scattering and one energy group. The convergence rate of the method is only weakly dependent on the scattering ratio of the problem. Instead, the rate of convergence depends strongly on the material thickness of the slab, with thick slabs converging in few iterations. The transient solution is obtained by applying a One Cell Inversion scheme instead of a Source Iteration based scheme. Thus, the transient unknowns are calculated with little coordination between them. This independence among unknowns makes our scheme ideally suited for transport calculations on parallel architectures. The slab geometry iterative scheme is adapted to XY geometry. Unfortunately, this attempt to extend the slab geometry iterative scheme to multiple dimensions has not been successful. The exact filtering scheme needed to discriminate asymptotic and transient modes has not been obtained and attempts to approximate this filtering process resulted in a divergent iterative scheme. However, the development of this iterative scheme yield valuable analysis tools to understand the Case-mode structure of any spatial discretization under arbitrary material properties.

Maslowski Olivares, Alexander Enrique

2008-12-01T23:59:59.000Z

104

ITER, fusion and the power reactor Leonid E. Zakharov,  

E-Print Network (OSTI)

came from outside of the FES "street light spot" when propulsion of lithium was invented as potentially the fusion research in the World. It also should affect the US approach to the reactor. 1 ITER and the basic reactor, it is necessary to realize that the ITER project, although vital for keeping fusion research

Zakharov, Leonid E.

105

Iterated local search for biclustering of microarray data  

Science Conference Proceedings (OSTI)

In the context of microarray data analysis, biclustering aims to identify simultaneously a group of genes that are highly correlated across a group of experimental conditions. This paper presents a Biclustering Iterative Local Search (BILS) algorithm ... Keywords: analysis of DNA microarray data, biclustering, evaluation function, iterative local search

Wassim Ayadi; Mourad Elloumi; Jin-Kao Hao

2010-09-01T23:59:59.000Z

106

Multi-sensor calibration through iterative registration and fusion  

Science Conference Proceedings (OSTI)

In this paper, a new multi-sensor calibration approach, called iterative registration and fusion (IRF), is presented. The key idea of this approach is to use surfaces reconstructed from multiple point clouds to enhance the registration accuracy and robustness. ... Keywords: B-spline surface reconstruction, Iterative closest point (ICP), Kalman filter, Registration, Sensor calibration

Yunbao Huang; Xiaoping Qian; Shiliang Chen

2009-04-01T23:59:59.000Z

107

Key issues in ITER diagnostics: Problems and solutions (invited)  

Science Conference Proceedings (OSTI)

The key problems associated with designing diagnostic systems for the International Thermonuclear Experimental Reactor (ITER) are identified and representative solutions are described. The plans for dealing with some outstanding issues are briefly presented. The detailed work is specific to the ITER

A. E. Costley; Members of the ITER Joint Central Team and Home Teams

1999-01-01T23:59:59.000Z

108

CMVRTC: Medium Truck Duty Cycle  

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

medium truck duty cycle (MTdc) project medium truck duty cycle (MTdc) project OVERVIEW The Medium Truck Duty Cycle (MTDC) project involves efforts to collect, analyze and archive data related to medium-truck operations in real-world driving environments. Such data and information will be useful to support technology evaluation efforts and to provide a means of accounting for real-world driving performance within medium-class truck analyses. The project involves private industry partners from various truck vocations. The MTDC project is unique in that there currently does not exist a national database of characteristic duty cycles for medium trucks. This project involves the collection of data from multiple vocations (four vocations) and multiple vehicles within these vocations (three vehicles per

109

Microsoft Word - Second_ ITER Council Press Release.doc  

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

Neil Calder Neil Calder Tel: 00 33 (0)6 14 16 41 75 ITER GAINS MOMENTUM Aomori, Japan 18 June 2008 On 17-18 June 2008, the ITER Council, the Governing Body of the new international Organization, convened for its second meeting. The two day meeting in Aomori, Japan, brought together senior representatives from the seven ITER Members: China, the European Union, India, Japan, Korea, Russia and the United States. Mr. Shingo Mimura, Governor of the Aomori Prefecture, welcomed delegates with a reminder of the global significance of the ITER project. "At a time when stable energy supplies and the promotion of strategies to tackle climate change are topics of global concern, the world is watching the ITER project. Implemented by seven parties that together make up half

110

Iterative Decoding and Turbo Equalization: The Z-Crease Phenomenon  

E-Print Network (OSTI)

Iterative probabilistic inference, popularly dubbed the soft-iterative paradigm, has found great use in a wide range of communication applications, including turbo decoding and turbo equalization. The classic approach of analyzing the iterative approach inevitably use the statistical and information-theoretical tools that bear ensemble-average flavors. This paper consider the per-block error rate performance, and analyzes it using nonlinear dynamical theory. By modeling the iterative processor as a nonlinear dynamical system, we report a universal "Z-crease phenomenon:" the zig-zag or up-and-down fluctuation -- rather than the monotonic decrease -- of the per-block errors, as the number of iteration increases. Using the turbo decoder as an example, we also report several interesting motion phenomenons which were not previously reported, and which appear to correspond well with the notion of "pseudo codewords" and "stopping/trapping sets." We further propose a heuristic stopping criterion to control Z-crease and identify the best iteration. Our stopping criterion is most useful for controlling the worst-case per-block errors, and helps to significantly reduce the average-iteration numbers.

Jing Li; Kai Xie

2013-06-03T23:59:59.000Z

111

The Carbon Cycle  

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

Carbon Cycle Print E-mail U.S. Carbon Cycle Science Program U.S. Carbon Cycle Science Program The U.S. Carbon Cycle Science Program, in consultation with the Carbon Cycle...

112

Mission of ITER and Challenges for the Young  

Science Conference Proceedings (OSTI)

It is recognized that the ongoing effort to provide sufficient energy for the wellbeing of the globe's population and to power the world economy is of the greatest importance. ITER is a joint international research and development project that aims to demonstrate the scientific and technical feasibility of fusion power. It represents the responsible actions of governments whose countries comprise over half the world's population, to create fusion power as a source of clean, economic, carbon dioxide-free energy. This is the most important science initiative of our time.The partners in the Project--the ITER Parties--are the European Union, Japan, the People's Republic of China, India, the Republic of Korea, the Russian Federation and the USA. ITER will be constructed in Europe, at Cadarache in the South of France. The talk will illustrate the genesis of the ITER Organization, the ongoing work at the Cadarache site and the planned schedule for construction. There will also be an explanation of the unique aspects of international collaboration that have been developed for ITER.Although the present focus of the project is construction activities, ITER is also a major scientific and technological research program, for which the best of the world's intellectual resources is needed. Challenges for the young, imperative for fulfillment of the objective of ITER will be identified. It is important that young students and researchers worldwide recognize the rapid development of the project, and the fundamental issues that must be overcome in ITER.The talk will also cover the exciting career and fellowship opportunities for young people at the ITER Organization.

Ikeda, Kaname [Director General, ITER Organization Cadarache Centre, 13108 St Paul lez Durance (France)

2009-02-19T23:59:59.000Z

113

PTRANSP Tests Of TGLF And Predictions For ITER  

Science Conference Proceedings (OSTI)

One of the physics goals for ITER is to achieve high fusion power PDT at a high gain QDT. This goal is important for studying the physics of reactor-relevant burning plasmas. Simulations of plasma performance in ITER can help achieve this goal by aiding in the design of systems such as diagnostics and in planning ITER plasma regimes. Simulations can indicate areas where further research in theory and experiments is needed. To have credible simulations integrated modeling is necessary since plasma profiles and applied heating, torque, and current drive are strongly coupled.

Robert V. Budny, Xingqiu Yuan, S. Jardin, G. Hammett, G. Staebler, members of the ITPA Transport and Confinement Topical Group, and JET EFDA Contributions

2012-02-28T23:59:59.000Z

114

Conference on iterative methods for large linear systems  

SciTech Connect

This conference is dedicated to providing an overview of the state of the art in the use of iterative methods for solving sparse linear systems with an eye to contributions of the past, present and future. The emphasis is on identifying current and future research directions in the mainstream of modern scientific computing. Recently, the use of iterative methods for solving linear systems has experienced a resurgence of activity as scientists attach extremely complicated three-dimensional problems using vector and parallel supercomputers. Many research advances in the development of iterative methods for high-speed computers over the past forty years are reviewed, as well as focusing on current research.

Kincaid, D.R. [comp.

1988-12-01T23:59:59.000Z

115

Carbon Cycle  

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

Carbon Cycle Carbon Cycle Latest Global Carbon Budget Estimates Including CDIAC Estimates Terrestrial Carbon Management Data Sets and Analyses Carbon Dioxide Emissions from Fossil-Fuel Consumption and Cement Manufacture, (2011) Annual Fossil-Fuel CO2 Emissions: Mass of Emissions Gridded by One Degree Latitude by One Degree Longitude (2012) Monthly Fossil-Fuel CO2 Emissions: Mass of Emissions Gridded by One Degree Latitude by One Degree Longitude (2012) Annual Fossil-Fuel CO2 Emissions: Global Stable Carbon Isotopic Signature (2012) Monthly Fossil-Fuel CO2 Emissions: Isomass (δ 13C) of Emissions Gridded by One Degree Latitude by One Degree Longitude (2012) AmeriFlux - Terrestrial Carbon Dioxide, Water Vapor, and Energy Balance Measurements Estimates of Monthly CO2 Emissions and Associated 13C/12C Values

116

Successful Experimental Verification of the Tokamak Exhaust Processing Concept of ITER with the CAPER Facility  

SciTech Connect

One of the design targets for the Tokamak Exhaust Processing (TEP) system of ITER is not to lose more than 10{sup -5}gh{sup -1} into the Normal Vent Detritiation system of the Tritium Plant. The plasma exhaust gas therefore needs to be processed in a way that a tritium removal efficiency of about 10{sup 8} with respect to the flow rate is achieved. Expressed in terms of tritium concentrations this corresponds to a decontamination from about 130 gm{sup -3} down to about 10{sup -4} gm{sup -3} (about 1 Cim{sup -3} = 3.7*10{sup 10} Bqm{sup -3}). The three step reference process for the TEP system of ITER is called CAPER and has been developed and realized at the Tritium Laboratory Karlsruhe (TLK). After the successful commissioning of the PERMCAT reactor as the key component of the third step detailed parametric tritium testing of the 3 steps involving the processing of more than 300 g tritium has been carried out and decontamination factors beyond the design requirements have been demonstrated for each process step and for the process as a whole. Not only the decontamination factor of 10{sup 8} as required by ITER, but also the operational mode of TEP as a waste dump for gases from diverse sources has been experimentally validated with the CAPER facility.

Bornschein, B.; Glugla, M.; Guenther, K.; Le, T.L.; Simon, K.H.; Welte, S. [Forschungszentrum Karlsruhe (Germany)

2005-07-15T23:59:59.000Z

117

Resent Status of ITER Equatorial Launcher Development  

SciTech Connect

The ITER equatorial launcher is divided into a front shield and a port plug. The front shield is composed of fourteen blanket shield modules so as to form three openings for the injection of mm-wave beams into plasma. Twenty-four waveguide transmission lines, internal shields, cooling pipes and so on are installed in the port plug. The transmission lines consist of the corrugated waveguides, miter bends and the free space propagation region utilizing two mirrors in front of the waveguide outlet. The analysis of mm-wave beam propagation in the region shows that the transmission efficiency more than 99.5% is attained. The high power experiments of the launcher mock-up have been carried out and the measured field patterns at each mirror and the outlet of the launcher are agreed with the calculations. It is concluded that the transmission line components in the launcher mock-up are fabricated as designed and the present mm-wave design in the launcher is feasible.

Takahashi, K.; Kajiwara, K.; Kasugai, A.; Oda, Y.; Kobayashi, N.; Sakamoto, K. [Japan Atomic Energy Agency, 801-1, Naka Ibaraki, 311-0193 (Japan)

2009-11-26T23:59:59.000Z

118

A Neutronics Shielding Mock-Up Experiment for Reduction of Uncertainty on the Prediction of the ITER-TFC Nuclear Heating  

Science Conference Proceedings (OSTI)

Technical Paper / First Joint ITER-IAEA Technical Meeting on Analysis of ITER Materials and Technologies

M. Angelone; P. Batistoni; F. Moro; M. Pillon; R. Villari; M. Loughlin

119

Experimental vertical stability studies for ITER performance and design  

E-Print Network (OSTI)

Operating experimental devices have provided key inputs to the design process for ITER axisymmetric control. In particular, experiments have quantified controllability and robustness requirements in the presence of realistic ...

Hutchinson, Ian H.

120

An Iterative EnKF for Strongly Nonlinear Systems  

Science Conference Proceedings (OSTI)

The study considers an iterative formulation of the ensemble Kalman filter (EnKF) for strongly nonlinear systems in the perfect-model framework. In the first part, a scheme is introduced that is similar to the ensemble randomized maximal ...

Pavel Sakov; Dean S. Oliver; Laurent Bertino

2012-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "involves iterative cycling" 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

United States and International Partners Initial ITER Agreement |  

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

International Partners Initial ITER Agreement International Partners Initial ITER Agreement United States and International Partners Initial ITER Agreement May 24, 2006 - 10:48am Addthis Paves the Way for Large-Scale, Clean Fusion Energy Project BRUSSELS, BELGIUM - Representing the United States, Dr. Raymond L. Orbach, Director of the U.S. Department of Energy's (DOE) Office of Science, joined counterparts from China, the European Union, India, Japan, the Republic of Korea, and the Russian Federation today to initial an agreement to construct ITER, an international fusion energy project. Fusion energy is an important component of President Bush's Advanced Energy Initiative (AEI), given fusion's potential to become an attractive long-range option for the U.S. clean energy portfolio. In FY 2006, DOE allocated $25

122

Monitoring a multi-agent system evolution through iterative development  

Science Conference Proceedings (OSTI)

Iterative development is a well know project management technique which has notably been popularized in object-oriented development through the use of the Rational Unified Process. Such an approach is nevertheless always driven by milestones rules on ...

Yves Wautelet; Manuel Kolp

2010-09-01T23:59:59.000Z

123

Accelerating Data Transfers In Iterative MapReduce Bingjing Zhang  

E-Print Network (OSTI)

Words-Iterative MapReduce; Data-intensive applications; Data transfer; Broadcasting; Shuffling; Fat-Tree topology I solvers and basic matrix primitives as the common computing kernels for computer vision, rendering

124

Policy iteration based on a learned transition model  

Science Conference Proceedings (OSTI)

This paper investigates a reinforcement learning method that combines learning a model of the environment with least-squares policy iteration (LSPI). The LSPI algorithm learns a linear approximation of the optimal state-action value function; the idea ...

Vivek Ramavajjala; Charles Elkan

2012-09-01T23:59:59.000Z

125

On-the-fly progress detection in iterative stream queries  

Science Conference Proceedings (OSTI)

Multiple researchers have proposed cyclic query plans for evaluating iterative queries over streams or rapidly changing input. The Declarative Networking community uses cyclic plans to evaluate Datalog programs that track reachability and other graph ...

Badrish Chandramouli; Jonathan Goldstein; David Maier

2009-08-01T23:59:59.000Z

126

International Thermonuclear Experimental Reactor (ITER) neutral beam design  

SciTech Connect

This report discusses the following topics on ITER neutral beam design: ion dump; neutralizer and module gas flow analysis; vacuum system; cryogenic system; maintainability; power distribution; and system cost.

Myers, T.J.; Brook, J.W.; Spampinato, P.T.; Mueller, J.P.; Luzzi, T.E.; Sedgley, D.W. (Grumman Corp., Bethpage, NY (USA). Space Systems Div.)

1990-10-01T23:59:59.000Z

127

An Iterative Radiative Transfer Code For Ocean-Atmosphere Systems  

Science Conference Proceedings (OSTI)

We describe the details of an iterative radiative transfer code for computing the intensity and degree of polarization of diffuse radiation in models of the ocean-atmosphere system. The present code neglects the upwelling radiation from below the ...

Ziauddin Ahmad; Robert S. Fraser

1982-03-01T23:59:59.000Z

128

JET physics in support of ITER: Results and future work  

Science Conference Proceedings (OSTI)

The JET Programme to 1999 concentrates on issues that must be solved before a decision to construct ITER can be taken. The paper discusses three areas representative of the physics support provided: confinement studies

M. Keilhacker; and the JET Team

1995-01-01T23:59:59.000Z

129

Development of the ITER magnetic diagnostic set and specification  

SciTech Connect

ITER magnetic diagnostics are now in their detailed design and R and D phase. They have passed their conceptual design reviews and a working diagnostic specification has been prepared aimed at the ITER project requirements. This paper highlights specific design progress, in particular, for the in-vessel coils, steady state sensors, saddle loops and divertor sensors. Key changes in the measurement specifications, and a working concept of software and electronics are also outlined.

Vayakis, G.; Delhom, D.; Encheva, A.; Giacomin, T.; Jones, L.; Patel, K. M.; Portales, M.; Prieto, D.; Simrock, S.; Snipes, J. A.; Udintsev, V. S.; Watts, C.; Winter, A.; Zabeo, L. [ITER Organization, Route de Vinon, F-13115 St Paul lez Durance (France); Arshad, S.; Perez-Lasala, M.; Sartori, F. [Fusion for Energy, Barcelona (Spain)

2012-10-15T23:59:59.000Z

130

An iterative semi-implicit scheme with robust damping  

Science Conference Proceedings (OSTI)

An efficient, iterative semi-implicit (SI) numerical method for the time integration of stiff wave systems is presented. Physics-based assumptions are used to derive a convergent iterative formulation of the SI scheme which enables the monitoring and ... Keywords: 52.30Ex, 52.35Hr, 52.35Py, 52.35Vd, 52.65Tt, Dispersive plasma waves, Gyrofluid, Magnetic reconnection, Robust damping, Semi-implicit methods, Symplectic methods

N. F. Loureiro; G. W. Hammett

2008-04-01T23:59:59.000Z

131

Rayleigh Quotient Iteration in 3D, Deterministic Neutron Transport  

Science Conference Proceedings (OSTI)

Today's "grand challenge" neutron transport problems require 3-D meshes with billions of cells, hundreds of energy groups, and accurate quadratures and scattering expansions. Leadership-class computers provide platforms on which high-fidelity fluxes can be calculated. However, appropriate methods are needed that can use these machines effectively. Such methods must be able to use hundreds of thousands of cores and have good convergence properties. Rayleigh quotient iteration (RQI) is an eigenvalue solver that has been added to the Sn code Denovo to address convergence. Rayleigh quotient iteration is an optimal shifted inverse iteration method that should converge in fewer iterations than the more common power method and other shifted inverse iteration methods for many problems of interest. Denovo's RQI uses a new multigroup Krylov solver for the fixed source solutions inside every iteration that allows parallelization in energy in addition to space and angle. This Krylov solver has been shown to scale successfully to 200,000 cores: for example one test problem scaled from 69,120 cores to 190,080 cores with 98% efficiency. This paper shows that RQI works for some small problems. However, the Krylov method upon which it relies does not always converge because RQI creates ill-conditioned systems. This result leads to the conclusion that preconditioning is needed to allow this method to be applicable to a wider variety of problems.

Slaybaugh, R [University of Wisconsin; Evans, Thomas M [ORNL; Davidson, Gregory G [ORNL; Wilson, P. [University of Wisconsin

2012-01-01T23:59:59.000Z

132

Visible and Infrared Optical Design for the ITER Upper Ports  

SciTech Connect

This document contains the results of an optical design scoping study of visible-light and infrared optics for the ITER upper ports, performed by LLNL under contract for the US ITER Project Office. ITER is an international collaboration to build a large fusion energy tokamak with a goal of demonstrating net fusion power for pulses much longer than the energy confinement time. At the time of this report, six of the ITER upper ports are planned to each to contain a camera system for recording visible and infrared light, as well as other diagnostics. the performance specifications for the temporal and spatial resolution of this system are shown in the Section II, Functional Specifications. They acknowledge a debt to Y. Corre and co-authors of the CEA Cadarache report ''ITER wide-angle viewing and thermographic and visible system''. Several of the concepts used in this design are derived from that CEA report. The infrared spatial resolution for optics of this design is diffraction-limited by the size of the entrance aperture, at lower resolution than listed in the ITER diagnostic specifications. The size of the entrance aperture is a trade-off between spatial resolution, optics size in the port, and the location of relay optics. The signal-to-noise ratio allows operation at the specified time resolutions.

Lasnier, C; Seppala, L; Morris, K; Groth, M; Fenstermacher, M; Allen, S; Synakowski, E; Ortiz, J

2007-03-01T23:59:59.000Z

133

Test blanket modules in ITER: An overview on proposed designs and required DEMO-relevant materials  

E-Print Network (OSTI)

Test blanket modules in ITER: An overview on proposed designs and required DEMO-relevant materials, Russian Federation Abstract Within the framework of the ITER Test Blanket Working Group, the ITER Parties have made several proposals for test blanket modules to be tested in ITER from the first day of H

Abdou, Mohamed

134

Understanding the petrochemical cycle: Part 1  

Science Conference Proceedings (OSTI)

Fitness in the hydrocarbon processing industry (HPI) arena involves understanding and coping with business cycles: supply and demand. This becomes increasingly more important as the industry globalizes and matures. Competitive-edge thinking needs to look hard at the forces that influence business cycles. Recognition of potential pitfalls is very important when considering: future capacity expansion, mergers and acquisitions, market departure, plant closure, potential product substitution, etc. Understanding pricing mechanisms and the workings of hockey-stick profitability profiles help HPI operators endure cycle downturns and prepare plants to maximize profits for the next upswing. The paper discusses characteristic trends, cycles in the hydrocarbon processing industry, current conditions, and mitigating cycle effects.

Sedriks, W. (SRI International, Menlo Park, CA (United States))

1994-03-01T23:59:59.000Z

135

Design and Analysis of the ITER Vertical Stability Coils  

SciTech Connect

The ITER vertical stability (VS) coils have been developed through the preliminary design phase by Princeton Plasma Physics Laboratory (PPPL). Final design, prototyping and construction will be carried out by the Chinese Participant Team contributing lab, Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP). The VS coils are a part of the in-vessel coil systems which include edge localized mode (ELM) coils as well as the VS coils. An overview of the ELM coils is provided in another paper at this conference. 15 The VS design employs four turns of stainless steel jacketed mineral insulated copper (SSMIC) conductors The mineral insulation is Magnesium Oxide (MgO). Joule and nuclear heat is removed by water flowing at 3 m/s through the hollow copper conductor. A key element in the design is that slightly elevated temperatures in the conductor and its support spine during operation impose compressive stresses that mitigate fatigue damage. Away from joints, and break-outs, conductor thermal stresses are low because of the axisymmetry of the winding (there are no corner bends as in the ELM coils).The 120 degree segment joint, and break-out or terminal regions are designed with similar but imperfect constraint compared with the ring coil portion of the VS. The support for the break-out region is made from a high strength copper alloy, CuCrZr. This is needed to conduct nuclear heat to the actively cooled conductor and to the vessel wall. The support "spine" for the ring coil portion of the VS is 316 stainless steel, held to the vessel with preloaded 718 bolts. Lorentz loads resulting from normal operating loads, disruption loads and loads from disruption currents in the support spine shared with vessel, are applied to the VS coil. The transmission of the Lorentz and thermal expansion loads from the "spine" to the vessel rails is via friction augmented with a restraining "lip" to ensure the coil frictional slip is minimal and acceptable. Stresses in the coil, joints, and break-outs are presented. These are compared with static and fatigue allowables. Design for fatigue is much less demanding than for the ELM coils. A total of 30,000 cycles is required for VS design. Loads on the vessel due to the thermal expansion of the coil and spine are significant. Efforts to reduce these by reducing the cross section of the spine have been made but the vessel still must support loads resulting from restraint of thermal expansion.

Peter H. Titus, et. al.

2012-09-06T23:59:59.000Z

136

Overview of ITER Fuel Cycle R&D and Design Activities by the European Home Team  

Science Conference Proceedings (OSTI)

Purification and Chemical Process / Proceedings of the Sixth International Conference on Tritium Science and Technology Tsukuba, Japan November 12-16, 2001

David Murdoch; Ch. Day; M. Glugla; R.oLaesser; A.Mack; R.-D. Penzhorn; A.Busigin; K.oMaynard; O. Kveton

137

Analysis of supercritical CO{sub 2} cycle control strategies and dynamic response for Generation IV Reactors.  

Science Conference Proceedings (OSTI)

The analysis of specific control strategies and dynamic behavior of the supercritical carbon dioxide (S-CO{sub 2}) Brayton cycle has been extended to the two reactor types selected for continued development under the Generation IV Nuclear Energy Systems Initiative; namely, the Very High Temperature Reactor (VHTR) and the Sodium-Cooled Fast Reactor (SFR). Direct application of the standard S-CO{sub 2} recompression cycle to the VHTR was found to be challenging because of the mismatch in the temperature drop of the He gaseous reactor coolant through the He-to-CO{sub 2} reactor heat exchanger (RHX) versus the temperature rise of the CO{sub 2} through the RHX. The reference VHTR features a large temperature drop of 450 C between the assumed core outlet and inlet temperatures of 850 and 400 C, respectively. This large temperature difference is an essential feature of the VHTR enabling a lower He flow rate reducing the required core velocities and pressure drop. In contrast, the standard recompression S-CO{sub 2} cycle wants to operate with a temperature rise through the RHX of about 150 C reflecting the temperature drop as the CO{sub 2} expands from 20 MPa to 7.4 MPa in the turbine and the fact that the cycle is highly recuperated such that the CO{sub 2} entering the RHX is effectively preheated. Because of this mismatch, direct application of the standard recompression cycle results in a relatively poor cycle efficiency of 44.9%. However, two approaches have been identified by which the S-CO{sub 2} cycle can be successfully adapted to the VHTR and the benefits of the S-CO{sub 2} cycle, especially a significant gain in cycle efficiency, can be realized. The first approach involves the use of three separate cascaded S-CO{sub 2} cycles. Each S-CO{sub 2} cycle is coupled to the VHTR through its own He-to-CO{sub 2} RHX in which the He temperature is reduced by 150 C. The three respective cycles have efficiencies of 54, 50, and 44%, respectively, resulting in a net cycle efficiency of 49.3 %. The other approach involves reducing the minimum cycle pressure significantly below the critical pressure such that the temperature drop in the turbine is increased while the minimum cycle temperature is maintained above the critical temperature to prevent the formation of a liquid phase. The latter approach also involves the addition of a precooler and a third compressor before the main compressor to retain the benefits of compression near the critical point with the main compressor. For a minimum cycle pressure of 1 MPa, a cycle efficiency of 49.5% is achieved. Either approach opens up the door to applying the SCO{sub 2} cycle to the VHTR. In contrast, the SFR system typically has a core outlet-inlet temperature difference of about 150 C such that the standard recompression cycle is ideally suited for direct application to the SFR. The ANL Plant Dynamics Code has been modified for application to the VHTR and SFR when the reactor side dynamic behavior is calculated with another system level computer code such as SAS4A/SYSSYS-1 in the SFR case. The key modification involves modeling heat exchange in the RHX, accepting time dependent tabular input from the reactor code, and generating time dependent tabular input to the reactor code such that both the reactor and S-CO{sub 2} cycle sides can be calculated in a convergent iterative scheme. This approach retains the modeling benefits provided by the detailed reactor system level code and can be applied to any reactor system type incorporating a S-CO{sub 2} cycle. This approach was applied to the particular calculation of a scram scenario for a SFR in which the main and intermediate sodium pumps are not tripped and the generator is not disconnected from the electrical grid in order to enhance heat removal from the reactor system thereby enhancing the cooldown rate of the Na-to-CO{sub 2} RHX. The reactor side is calculated with SAS4A/SASSYS-1 while the S-CO{sub 2} cycle is calculated with the Plant Dynamics Code with a number of iterations over a timescale of 500 seconds. It is found that the RHX u

Moisseytsev, A.; Sienicki, J. J. (Nuclear Engineering Division)

2011-04-12T23:59:59.000Z

138

THERMODYNAMIC ANALYSIS OF AMMONIA-WATER-CARBON DIOXIDE MIXTURES FOR DESIGNING NEW POWER GENERATION CYCLES  

SciTech Connect

This project was undertaken with the goal of developing a computational package for the thermodynamic properties of ammonia-water-carbon dioxide mixtures at elevated temperature and pressure conditions. This objective was accomplished by modifying an existing set of empirical equations of state for ammonia-water mixtures. This involved using the Wagner equation of state for the gas phase properties of carbon dioxide. In the liquid phase, Pitzer's ionic model was used. The implementation of this approach in the form of a computation package that can be used for the optimization of power cycles required additional code development. In particular, this thermodynamic model consisted of a large set of non-linear equations. Consequently, in the interest of computational speed and robustness that is required when applied to optimization problems, analytic gradients were incorporated in the Newton solver routines. The equations were then implemented using a stream property predictor to make initial guesses of the composition, temperature, pressure, enthalpy, entropy, etc. near a known state. The predictor's validity is then tested upon the convergence of an iteration. It proved difficult to obtain experimental data from the literature that could be used to test the accuracy of the new thermodynamic property package, and this remains a critical need for future efforts in the area. It was possible, however, to assess the feasibility of using this complicated property prediction package for power cycle design and optimization. Such feasibility was first demonstrated by modification of our Kalina cycle optimization code to use the package with either a deterministic optimizer, MINOS, or a stochastic optimizer using differential evolution, a genetic-algorithm-based technique. Beyond this feasibility demonstration, a new approach to the design and optimization of power cycles was developed using a graph theoretic approach.

Ashish Gupta

2003-01-15T23:59:59.000Z

139

President Bush Issues Executive Order Designating ITER International Fusion  

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

President President Bush Issues Executive Order Designating ITER International Fusion Energy Organization A Public Interest Organization News Featured Articles Science Headlines 2014 2013 2012 2011 2010 2009 2008 2007 2006 2005 Presentations & Testimony News Archives Contact Information Office of Science U.S. Department of Energy 1000 Independence Ave., SW Washington, DC 20585 P: (202) 586-5430 11.19.07 President Bush Issues Executive Order Designating ITER International Fusion Energy Organization A Public Interest Organization Print Text Size: A A A Subscribe FeedbackShare Page November 19, 2007 The White House today announced that President Bush has issued an Executive Order designating the ITER International Fusion Energy Organization as a public international organization. For the purposes of the International

140

Twice-iterated boson-exchange scattering amplitudes  

E-Print Network (OSTI)

We calculate at two-loop order the complex-valued scattering amplitude related to the twice-iterated scalar-isovector boson-exchange between nucleons. In comparison to the once-iterated boson-exchange amplitude it shows less dependence on the scattering angle. We calculate also the iteration of the (static) irreducible one-loop potential with the one-boson exchange and find similar features. Together with the irreducible three-boson exchange potentials and the two-boson exchange potentials with vertex corrections, which are also evaluated analytically, our results comprise all nonrelativistic contributions from scalar-isovector boson-exchange at one- and two-loop order. The applied methods can be straightforwardly adopted to the pseudoscalar pion with its spin- and momentum-dependent couplings to the nucleon.

N. Kaiser

2006-06-12T23:59:59.000Z

Note: This page contains sample records for the topic "involves iterative cycling" 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.
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141

Diagnostics of the ITER neutral beam test facility  

SciTech Connect

The ITER heating neutral beam (HNB) injector, based on negative ions accelerated at 1 MV, will be tested and optimized in the SPIDER source and MITICA full injector prototypes, using a set of diagnostics not available on the ITER HNB. The RF source, where the H{sup -}/D{sup -} production is enhanced by cesium evaporation, will be monitored with thermocouples, electrostatic probes, optical emission spectroscopy, cavity ring down, and laser absorption spectroscopy. The beam is analyzed by cooling water calorimetry, a short pulse instrumented calorimeter, beam emission spectroscopy, visible tomography, and neutron imaging. Design of the diagnostic systems is presented.

Pasqualotto, R.; Serianni, G.; Agostini, M.; Brombin, M.; Dalla Palma, M.; Gazza, E.; Pomaro, N.; Rizzolo, A.; Spolaore, M.; Zaniol, B. [Consorzio RFX, Associazione EURATOM-ENEA sulla Fusione, Corso Stati Uniti 4, I-35127 Padova (Italy); Sonato, P.; De Muri, M. [Consorzio RFX, Associazione EURATOM-ENEA sulla Fusione, Corso Stati Uniti 4, I-35127 Padova (Italy); Dipartimento di Ingegneria Elettrica, Padova University (Italy); Croci, G. [Istituto di Fisica del Plasma, Associazione EURATOM-ENEA-CNR, Milano (Italy); Gorini, G. [Istituto di Fisica del Plasma, Associazione EURATOM-ENEA-CNR, Milano (Italy); CNISM, Dipartimento di Fisica, Universita degli Studi di Milano-Bicocca, Milano (Italy)

2012-02-15T23:59:59.000Z

142

Iterated Differential Forms IV: C-Spectral Sequence  

E-Print Network (OSTI)

For the multiple differential algebra of iterated differential forms (see math.DG/0605113 and math.DG/0609287) on a diffiety (O,C) an analogue of C-spectral sequence is constructed. The first term of it is naturally interpreted as the algebra of secondary iterated differential forms on (O,C). This allows to develop secondary tensor analysis on generic diffieties, some simplest elements of which are sketched here. The presented here general theory will be specified to infinite jet spaces and infinitely prolonged PDEs in subsequent notes.

A. M. Vinogradov; L. Vitagliano

2006-10-30T23:59:59.000Z

143

Bragg x-ray survey spectrometer for ITER  

Science Conference Proceedings (OSTI)

Several potential impurity ions in the ITER plasmas will lead to loss of confined energy through line and continuum emission. For real time monitoring of impurities, a seven channel Bragg x-ray spectrometer (XRCS survey) is considered. This paper presents design and analysis of the spectrometer, including x-ray tracing by the Shadow-XOP code, sensitivity calculations for reference H-mode plasma and neutronics assessment. The XRCS survey performance analysis shows that the ITER measurement requirements of impurity monitoring in 10 ms integration time at the minimum levels for low-Z to high-Z impurity ions can largely be met.

Varshney, S. K.; Jakhar, S. [ITER-India, Institute for Plasma Research, Bhat, Gandhinagar, Gujarat 382428 (India); Barnsley, R. [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance (France); O'Mullane, M. G. [Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom)

2012-10-15T23:59:59.000Z

144

STELLOPT Modeling of the 3D Diagnostic Response in ITER  

SciTech Connect

The ITER three dimensional diagnostic response to an n=3 resonant magnetic perturbation is modeled using the STELLOPT code. The in-vessel coils apply a resonant magnetic perturbation (RMP) fi eld which generates a 4 cm edge displacement from axisymmetry as modeled by the VMEC 3D equilibrium code. Forward modeling of flux loop and magnetic probe response with the DIAGNO code indicates up to 20 % changes in measured plasma signals. Simulated LIDAR measurements of electron temperature indicate 2 cm shifts on the low field side of the plasma. This suggests that the ITER diagnostic will be able to diagnose the 3D structure of the equilibria.

Lazerson, Samuel A

2013-05-07T23:59:59.000Z

145

Power radiated from ITER and CIT by impurities  

Science Conference Proceedings (OSTI)

The MIST code has been used to model impurity radiation from the edge and core plasmas in ITER and CIT. A broad range of parameters have been varied, including Z{sub eff}, impurity species, impurity transport coefficients, and plasma temperature and density profiles, especially at the edge. For a set of these parameters representative of the baseline ITER ignition scenario, it is seen that impurity radiation, which is produced in roughly equal amounts by the edge and core regions, can make a major improvement in divertor operation without compromising core energy confinement. Scalings of impurity radiation with atomic number and machine size are also discussed. 22 refs., 16 figs.

Cummings, J.; Cohen, S.A.; Hulse, R.; Post, D.E.; Redi, M.H.; Perkins, J.

1990-07-01T23:59:59.000Z

146

Definition: Brayton cycle | Open Energy Information  

Open Energy Info (EERE)

form form View source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Definition Edit with form History Facebook icon Twitter icon » Definition: Brayton cycle Jump to: navigation, search Dictionary.png Brayton cycle A thermodynamic cycle using constant pressure, heat addition and rejection. Fuel and a compressor are used to heat and increase the pressure of a gas; the gas expands and spins the blades of a turbine, which, when connected to a generator, generates electricity.[1][2] View on Wikipedia Wikipedia Definition The Brayton cycle is a thermodynamic cycle that describes the workings of a constant pressure heat engine. Gas turbine engines and airbreathing jet engines use the Brayton Cycle. Although the Brayton cycle

147

Overview of Recent Developments in Pellet Injection for ITER  

Science Conference Proceedings (OSTI)

Pellet injection is the primary fueling technique planned for core fueling of ITER burning plasmas. Also, the injection of relatively small pellets to purposely trigger rapid small edge localized modes (ELMs) has been proposed as a possible solution to the heat flux damage from larger natural ELMs likely to be an issue on the ITER divertor surfaces. The ITER pellet injection system is designed to inject pellets into the plasma through both inner and outer wall guide tubes. The inner wall guide tubes will provide high throughput pellet fueling while the outerwall guide tubes will be used primarily to trigger ELMs at a high frequency (>15 Hz). The pellet fueling rate ofeach injector is to be up to 120 Pa-m3/s, which will require the formation of solid D-T at a volumetric rate of ~1500 mm3/s. Two injectors are to be provided for ITER at the startup with a provision for up to six injectorsduring the D-T phase. The required throughput of each injector is greater than that of any injector built to date, and a novel twin-screw continuous extrusion system is being developed to meet the challenging design parameters. Status of the development activities will be presented, highlighting recent progress.

Combs, Stephen Kirk [ORNL; Baylor, Larry R [ORNL; Meitner, Steven J [ORNL; Caughman, John B [ORNL; Rasmussen, David A [ORNL; Maruyama, So [ITER Organization, Cadarache, France

2012-01-01T23:59:59.000Z

148

PTRANSP Tests of TGLF and Predictions for ITER  

SciTech Connect

A new numerical solver for stiff transport predictions has been developed and implemented in the PTRANSP predictive transport code. The TGLF and GLF23 predictive codes have been incorporated in the solver, verified by comparisons with predictions from the XPTOR code, and validated by comparing predicted and measured profiles. Predictions for ITER baseline plasmas are presented.

Robert V. Budny, Xingqiu Yuan, S. Jardin, G. Hammett, G. Staebler, J. Kinsey, members of the ITPA Transport and Confinement Topical Group, and JET EFDA Contributors

2012-09-23T23:59:59.000Z

149

Active spectroscopic measurements using the ITER diagnostic system  

SciTech Connect

Active (beam-based) spectroscopic measurements are intended to provide a number of crucial parameters for the ITER device being built in Cadarache, France. These measurements include the determination of impurity ion temperatures, absolute densities, and velocity profiles, as well as the determination of the plasma current density profile. Because ITER will be the first experiment to study long timescale ({approx}1 h) fusion burn plasmas, of particular interest is the ability to study the profile of the thermalized helium ash resulting from the slowing down and confinement of the fusion alphas. These measurements will utilize both the 1 MeV heating neutral beams and a dedicated 100 keV hydrogen diagnostic neutral beam. A number of separate instruments are being designed and built by several of the ITER partners to meet the different spectroscopic measurement needs and to provide the maximum physics information. In this paper, we describe the planned measurements, the intended diagnostic ensemble, and we will discuss specific physics and engineering challenges for these measurements in ITER.

Thomas, D. M. [ITER Organization, 13067 St. Paul-lez-Durance Cedex (France); Counsell, G. [Fusion for Energy, 08019 Barcelona (Spain); Johnson, D. [US ITER Project Office, Oak Ridge, Tennessee 37830 (United States); Vasu, P. [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India); Zvonkov, A. [Russian Research Center ''Kurchatov Institute'', Moscow 123182 (Russian Federation)

2010-10-15T23:59:59.000Z

150

Iterative maximum-likelihood reconstruction in quantum homodyne tomography  

E-Print Network (OSTI)

I propose an iterative expectation maximization algorithm for reconstructing a quantum optical ensemble from a set of balanced homodyne measurements performed on an optical state. The algorithm applies directly to the acquired data, bypassing the intermediate step of calculating marginal distributions. The advantages of the new method are made manifest by comparing it with the traditional inverse Radon transformation technique.

A. I. Lvovsky

2003-11-14T23:59:59.000Z

151

Image segmentation by iterated region merging with localized graph cuts  

Science Conference Proceedings (OSTI)

This paper presents an iterated region merging-based graph cuts algorithm which is a novel extension of the standard graph cuts algorithm. Graph cuts addresses segmentation in an optimization framework and finds a globally optimal solution to a wide ... Keywords: Graph cuts, Image segmentation, Region merging

Bo Peng; Lei Zhang; David Zhang; Jian Yang

2011-10-01T23:59:59.000Z

152

Object oriented parallelisation of graph algorithms using parallel iterator  

Science Conference Proceedings (OSTI)

Multi-core machines are becoming widely used which, as a consequence, forces parallel computing to move from research labs to being adopted everywhere. Due to the fact that developing parallel code is a significantly complex process, the main focus of ... Keywords: graph algorithms, object oriented parallelisation, parallel computing, parallel iterator

Lama Akeila; Oliver Sinnen; Wafaa Humadi

2010-01-01T23:59:59.000Z

153

Robust measurement of ocular torsion using iterative Lucas-Kanade  

Science Conference Proceedings (OSTI)

We present a new method to measure ocular torsion using Lucas-Kanade method. After pixels of iris annulus around a pupil have been converted into Cartesian coordinates, 30 features on the iris was selected then the features were tracked using the iterative ... Keywords: Eye tracking, Lucas-Kanade, Ocular torsion

InBum Lee; ByungHun Choi; Kwang Suk Park

2007-03-01T23:59:59.000Z

154

ITER:The Future International Burning Plasma Experiment Present Status  

E-Print Network (OSTI)

at the time of procurement. #12;ITER27/4/01 Design - In-vessel Remote Handling (1) Systems near the plasma will become radioactive and will require remote maintenance, with special remote handling equipment. In27/4/01 Design - In-vessel Remote Handling (2) Comprehensive R&D has successfully demonstrated

155

SULTAN measurement and qualification: ITER-US-LLNL-NMARTOVETSKY- 092008  

SciTech Connect

Measuring the characteristics of full scale ITER CICC at SULTAN is the critical qualification test. If volt-ampere characteristic (VAC) or volt-temperature characteristic (VTC) are distorted, the criterion of 10 uV/m may not be a valid criterion to judge the conductor performance. Only measurements with a clear absence or low signals from the current distribution should be considered as quantitatively representative, although in some obvious circumstances one can judge if a conductor will meet or fail ITER requirements. SULTAN full scale ITER CICC testing should be done with all measures taken to ensure uniform current redistribution. A full removal of Cr plating in the joint area and complete solder filling of the joints (with provision of the central channel for helium flow) should be mandatory for DC qualification samples for ITER. Also, T and I should be increased slowly that an equilibrium could be established for accurate measurement of Tcs, Ic and N. It is also desirable to go up in down in current and/or temperature (within stable range) to make sure that the equilibrium is reached.

Martovetsky, N N

2006-09-21T23:59:59.000Z

156

Iterative improvement to solve the parcel hub scheduling problem  

Science Conference Proceedings (OSTI)

This paper presents iterative improvement algorithms to solve the parcel hub scheduling problem (PHSP). The PHSP is combinatorial optimization problem that consists of scheduling a set of inbound trailers to a small number of unload docks. At the unload ... Keywords: Cross docks, Genetic algorithms, Local search, Parcel delivery industry, Simulated annealing

Douglas L. McWilliams

2010-08-01T23:59:59.000Z

157

US Plans and Strategy for ITER Blanket Testing  

E-Print Network (OSTI)

per 1000MW fusion power per year Production & Cost · CANDU Reactors: 27 kg from over 40 years, $30MOntario(OPG)TritiumInventory(kg) CANDU Supply w/o Fusion ITER-FEAT (2004 start) 1000 MW Fusion, 10% Avail, TBR 0.0 #12;

California at Los Angeles, University of

158

Optimization-based iterative learning for precise quadrocopter trajectory tracking  

Science Conference Proceedings (OSTI)

Current control systems regulate the behavior of dynamic systems by reacting to noise and unexpected disturbances as they occur. To improve the performance of such control systems, experience from iterative executions can be used to anticipate recurring ... Keywords: Aerial robotics, Convex optimization, Input and state constraints, Kalman filtering, Learning, Motion planning and control, Quadrocopter control, Trajectory tracking

Angela P. Schoellig; Fabian L. Mueller; Raffaello D'Andrea

2012-08-01T23:59:59.000Z

159

Advanced tokamak operating modes in TPX and ITER  

SciTech Connect

A program is described to develop the advanced tokamak physics required for an economic steady-state fusion reactor on existing (short-pulse) tokamak experiments; to extend these operating modes to long-pulse on TPX; and finally to demonstrate them in a long-pulse D-T plasma on ITER.

Nevins, W.M.

1994-12-31T23:59:59.000Z

160

Iterative methods for visualization of implicit surfaces on GPU  

Science Conference Proceedings (OSTI)

The ray-casting of implicit surfaces on GPU has been explored in the last few years. However, until recently, they were restricted to second degree (quadrics). We present an iterative solution to ray cast cubics and quartics on GPU. Our solution targets ...

Rodrigo de Toledo; Bruno Levy; Jean-Claude Paul

2007-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "involves iterative cycling" 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

Production and Handling Slide 5: The Uranium Fuel Cycle  

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

Refer to caption below for image description The third step in the uranium fuel cycle involves the conversion of "yellowcake" to uranium hexafluoride (UF6), the chemical form...

162

Iterative aperture mask design in phase space using a rank constraint  

E-Print Network (OSTI)

We present an iterative camera aperture design procedure, which determines an optimal mask pattern based on a sparse set of desired intensity distributions at different focal depths. This iterative method uses the ambiguity ...

Horstmeyer, Roarke William

163

Reachability analysis of nonlinear analog circuits through iterative reachable set reduction  

Science Conference Proceedings (OSTI)

We propose a methodology for reachability analysis of nonlinear analog circuits to verify safety properties. Our iterative reachable set reduction algorithm initially considers the entire state space as reachable. Our algorithm iteratively determines ...

Seyed Nematollah Ahmadyan, Shobha Vasudevan

2013-03-01T23:59:59.000Z

164

Combining GA and iterative MVDR for DOA estimation in space-time CDMA systems  

Science Conference Proceedings (OSTI)

This paper deals with direction-of-arrival (DOA) estimation of minimum variance distortionless response (MVDR) approach based on iterative searching technique for space-time code-division multiple access (CDMA) systems. It has been shown that the iterative ...

Jhih-Chung Chang

2012-11-01T23:59:59.000Z

165

Energy and particle confinement in ITER (International Thermonuclear Experimental Reactor)  

SciTech Connect

ITER will require a level of energy ({tau}{sub E}) and particle ({tau}{sub p}) confinement sufficient for reaching ignition and extended burn of DT plasmas, with steady-state, high-Q (Q = P{sub fusion}/P{sub aux} = 5P{sub {alpha}}/P{sub aux}) operation as an ultimate goal. This translates into a required confinement capability of T{sub i}(0)n{sub DT}(0){tau}{sub E} {approximately}4--8 {times} 10{sup 21} keV{center dot}s/m{sup 3} for Q {approximately}5--{infinity} (where T{sub i}(0) is the central ion temperature, n{sub DT}(0) is the central DT fuel ion density, {tau}{sub E} is the global energy confinement time). In addition, {tau}{sub p} {sup He}/{tau}{sub E} < 10 is required to ensure that the thermal {alpha}-particle (He) accumulation (n{sub He}/n{sub e}) is less than 10% (where {tau}{sub p}{sup He} is the global thermal alpha particle containment time). Furthermore, the tritium fuel burnup fraction under nominal burn conditions must be greater than 1.5%. While the ITER Tn{tau}{sub E} requirement is about ten times the highest value achieved in JET (3), the extrapolation in plasma physics parameters is less. If {beta} (ratio of plasma kinetic pressure to magnetic pressure), {nu}* (collisionality), and {rho}/a (ratio of the ion gyroradius to the plasma minor radius) are taken as the relevant dimensionless parameters to characterize the plasma, the extrapolation from present JET performance to ITER is a factor {le}2. The ITER concept is based on the expectation that H-mode confinement can be achieved for long pulse. This paper covers the energy and particle confinement issues for ITER. 15 refs.

Uckan, N.A. (Oak Ridge National Lab., TN (USA)); Yushmanov, P.N.; Mukhovatov, V.S.; Parail, V.V.; Putvinskii, S. (Gosudarstvennyj Komitet po Ispol'zovaniyu Atomnoj Ehnergii SSSR, Moscow (USSR). Inst. Atomnoj Ehnergii); Takizuka, T.; Tsunematsu, T.; Yoshino, R. (Japan Atomic Energy Research Inst., Tokyo (Japan)); Borrass, K.; Engelmann, F.; Kardaun, O.; Lackner, K. (Max-Planck-Institut fuer Plasmaphysik,

1990-01-01T23:59:59.000Z

166

Thermomechanical Performance of the EU TBMs Under a Typical ITER Transient  

Science Conference Proceedings (OSTI)

ITER Systems / Proceedings of the Nineteenth Topical Meeting on the Technology of Fusion Energy (TOFE) (Part 1)

F. Cismondi; G. Aiello; S. Kecskes; G. Rampal

167

Thermomechanical Analysis of the Revised U.S. ITER DCLL Test Blanket Module  

Science Conference Proceedings (OSTI)

ITER Systems / Proceedings of the Nineteenth Topical Meeting on the Technology of Fusion Energy (TOFE) (Part 1)

Aaron T. Aoyama; Shahram Sharafat; Nasr Ghoniem; Mohamad Dagher; Clement Wong

168

RAMI Analysis for Designing and Optimizing ITER Tokamak Cooling Water System  

Science Conference Proceedings (OSTI)

ITER Systems / Proceedings of the Nineteenth Topical Meeting on the Technology of Fusion Energy (TOFE) (Part 1)

J. J. Ferrada; W. T. Reiersen

169

Critical Design Issues of the Tokamak Cooling Water System of ITER's Fusion Reactor  

Science Conference Proceedings (OSTI)

ITER Systems / Proceedings of the Nineteenth Topical Meeting on the Technology of Fusion Energy (TOFE) (Part 1)

Seokho H. Kim; Jeanette B. Berry

170

High Heat Flux Test of the KO Standard Mockups for ITER First Wall Semi-Prototype  

Science Conference Proceedings (OSTI)

ITER Systems / Proceedings of the Nineteenth Topical Meeting on the Technology of Fusion Energy (TOFE) (Part 1)

Suk-Kwon Kim et al.

171

Modeling and Simulation of the ITER First Wall/Blanket Primary Heat Transfer System  

Science Conference Proceedings (OSTI)

ITER Systems / Proceedings of the Nineteenth Topical Meeting on the Technology of Fusion Energy (TOFE) (Part 1)

Emilian Popov; Alice Ying

172

An Iterative Method for the Construction of Equilibrium N-Body Models for Stellar Disks  

E-Print Network (OSTI)

One widely used technique for the construction of equilibrium models of stellar disks is based on the Jeans equations and the moments of velocity distribution functions derived using these equations. Stellar disks constructed using this technique are shown to be "not entirely" in equilibrium. Our attempt to abandon the epicyclic approximation and the approximation of infinite isothermal layers, which are commonly adopted in this technique, failed to improve the situation substantially. We conclude that the main drawback of techniques based on the Jeans equations is that the system of equations employed is not closed, and therefore requires adopting an essentially ad hoc additional closure condition. A new iterative approach to constructing equilibrium N-body models with a given density distribution is proposed. The main idea behind this approach is that a model is first constructed using some approximation method, and is then allowed to adjust to an equilibrium state with the specified density and the required parameters of the velocity distribution remaining fixed in the process. This iterative approach was used to construct isotropic, spherically symmetric models and models of stellar disks embedded in an external potential. The numerical models constructed prove to be close to equilibrium. It is shown that the commonly adopted assumption that the profile of the radial velocity dispersion is exponential may be wrong. The technique proposed can be applied to a wide range of problems involving the construction of models of stellar systems with various geometries.

S. A. Rodionov; N. Ya. Sotnikova

2006-11-06T23:59:59.000Z

173

U.S ITER : electromagnetic analysis of transient forces due to disrupted plasma currents on the ITER shield modules.  

SciTech Connect

This paper describes the electromagnetic analysis that has been completed using the OPERA-3d product to characterize the forces on the ITER shield modules as part of the conceptual design. These forces exist due to the interaction of the eddy currents induced in the shield modules and the large magnetic fields present in the tokamak.

Kotulski, Joseph Daniel; Coats, Rebecca Sue; Pasik, Michael Francis

2007-06-01T23:59:59.000Z

174

Home National Sports Business World Features Columns Editorial Japan has key role in ITER project  

E-Print Network (OSTI)

the Congress concerning the United States' share of the costs of the ITER project. The United States quit project The Yomiuri Shimbun The dispute over which nation should host the world's first nuclear fusion, using the ITER project as a basis for achieving the goal. The ITER would be a gigantic facility

175

On HSS and AHSS iteration methods for nonsymmetric positive definite Toeplitz systems  

Science Conference Proceedings (OSTI)

Two iteration methods are proposed to solve real nonsymmetric positive definite Toeplitz systems of linear equations. These methods are based on Hermitian and skew-Hermitian splitting (HSS) and accelerated Hermitian and skew-Hermitian splitting (AHSS). ... Keywords: 65F10, 65F50, AHSS iteration method, Centrosymmetric matrix, HSS iteration method, Skew-centrosymmetric matrix, Toeplitz matrix

Fang Chen; Yao-Lin Jiang

2010-08-01T23:59:59.000Z

176

A Combined Adaptive Law for Fuzzy Iterative Learning Control of Nonlinear Systems With Varying Control Tasks  

Science Conference Proceedings (OSTI)

To deal with the iterative control of uncertain nonlinear systems with varying control tasks, nonzero initial resetting state errors, and nonrepeatable mismatched input disturbance, a new adaptive fuzzy iterative learning controller is proposed in this ... Keywords: Adaptive control, fuzzy system, iterative learning control (ILC), nonlinear systems

Chiang-Ju Chien

2008-02-01T23:59:59.000Z

177

Bi-parameter incremental unknowns ADI iterative methods for elliptic problems  

Science Conference Proceedings (OSTI)

Bi-parameter incremental unknowns (IU) alternating directional implicit (ADI) iterative methods are proposed for solving elliptic problems. Condition numbers of the coefficient matrices for these iterative schemes are carefully estimated. Theoretical ... Keywords: Bi-parameter ADI iterative method, Condition number, Convergence analysis, Incremental unknowns

Aili Yang; Yujiang Wu; Yongqing Wu; Dawei Ren

2012-07-01T23:59:59.000Z

178

Basis functions and parameter optimisation in high-order iterative learning control  

Science Conference Proceedings (OSTI)

In this paper a new parameter-optimal high-order Iterative Learning Control (ILC) algorithms is proposed to extend the work of Owens and Feng [Parameter optimisation in iterative learning control. International Journal of Control 14(11), 1059-1069]. ... Keywords: Basis functions, Iterative learning control, Parameter optimisation

J. HäTöNen; D. H. Owens; K. Feng

2006-02-01T23:59:59.000Z

179

Two-step modulus-based matrix splitting iteration method for linear complementarity problems  

Science Conference Proceedings (OSTI)

Bai has recently presented a modulus-based matrix splitting iteration method, which is a powerful alternative for solving the large sparse linear complementarity problems. In this paper, we further present a two-step modulus-based matrix splitting iteration ... Keywords: Convergence, Iteration method, Linear complementarity problem, Matrix splitting

Li-Li Zhang

2011-05-01T23:59:59.000Z

180

Modulus-based synchronous two-stage multisplitting iteration methods for linear complementarity problems  

Science Conference Proceedings (OSTI)

In order to solve large sparse linear complementarity problems on parallel multiprocessor systems, we construct modulus-based synchronous two-stage multisplitting iteration methods based on two-stage multisplittings of the system matrices. These iteration ... Keywords: Convergence, Linear complementarity problem, Matrix multisplitting, Modulus method, Successive relaxation, Two-stage iteration

Zhong-Zhi Bai; Li-Li Zhang

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "involves iterative cycling" 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

A hierarchical fracture model for the iterative multiscale finite volume method  

Science Conference Proceedings (OSTI)

An iterative multiscale finite volume (i-MSFV) method is devised for the simulation of multiphase flow in fractured porous media in the context of a hierarchical fracture modeling framework. Motivated by the small pressure change inside highly conductive ... Keywords: Fractured porous media, Hierarchical fractured modeling, Iterative multiscale finite volume, Iterative multiscale methods, Multiscale finite volume, Multiscale fracture modeling, Multiscale methods

Hadi Hajibeygi; Dimitris Karvounis; Patrick Jenny

2011-10-01T23:59:59.000Z

182

Life Cycle Engineering Group  

Science Conference Proceedings (OSTI)

... for green manufacturing and construction applications; conduct life cycle engineering assessments for energy efficiency and environmental ...

2012-08-23T23:59:59.000Z

183

Cell cycle nucleic acids, polypeptides and uses thereof  

DOE Patents (OSTI)

The invention provides isolated nucleic acids and their encoded proteins that are involved in cell cycle regulation. The invention further provides recombinant expression cassettes, host cells, transgenic plants, and antibody compositions. The present invention provides methods and compositions relating to altering cell cycle protein content, cell cycle progression, cell number and/or composition of plants.

Gordon-Kamm, William J. (Urbandale, IA); Lowe, Keith S. (Johnston, IA); Larkins, Brian A. (Tucson, AZ); Dilkes, Brian R. (Tucson, AZ); Sun, Yuejin (Westfield, IN)

2007-08-14T23:59:59.000Z

184

An alpha particle measurement system using an energetic neutral helium beam in ITER (invited)  

Science Conference Proceedings (OSTI)

An energetic helium neutral beam is involved in the beam neutralization measurement system of alpha particles confined in a DT fusion plasma. A full size strong-focusing He{sup +} ion source (2 A, the beam radius of 11.3 mm, the beam energy less than 20 keV). Present strong-focusing He{sup +} ion source shows an emittance diagram separated for each beamlet of multiple apertures without phase space mixing, despite the space charge of a beamlet is asymmetric and the beam flow is non-laminar. The emittance of beamlets in the peripheral region was larger than that of center. The heat load to the plasma electrode was studied to estimate the duty factor for the ITER application.

Sasao, M.; Tanaka, N.; Terai, K.; Kaneko, O. [Graduate school of Engineering, Tohoku University, Sendai 980-8579 (Japan); Kisaki, M.; Kobuchi, T.; Tsumori, K.; Okamoto, A.; Kitajima, S. [National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan); Shinto, K. [IFMIF R and D Center, Japan Atomic Energy Agency, Rokkasho, Aomori 039-3212 (Japan); Wada, M. [Graduate School of Engineering, Doshisha University, Kyotanabe, Kyoto 610-0321 (Japan)

2012-02-15T23:59:59.000Z

185

An iterative method to compute the overlap Dirac operator at nonzero chemical potential  

E-Print Network (OSTI)

The overlap Dirac operator at nonzero quark chemical potential involves the computation of the sign function of a non-Hermitian matrix. In this talk we present an iterative method, first proposed by us in Ref. [1], which allows for an efficient computation of the operator, even on large lattices. The starting point is a Krylov subspace approximation, based on the Arnoldi algorithm, for the evaluation of a generic matrix function. The efficiency of this method is spoiled when the matrix has eigenvalues close to a function discontinuity. To cure this, a small number of critical eigenvectors are added to the Krylov subspace, and two different deflation schemes are proposed in this augmented subspace. The ensuing method is then applied to the sign function of the overlap Dirac operator, for two different lattice sizes. The sign function has a discontinuity along the imaginary axis, and the numerical results show how deflation dramatically improves the efficiency of the method.

Jacques Bloch; Andreas Frommer; Bruno Lang; Tilo Wettig

2007-10-01T23:59:59.000Z

186

Qualification of the Joints for ITER Central Solenoid  

SciTech Connect

The ITER Central Solenoid has 36 interpancake joints, 12 bus joints, and 12 feeder joints in the magnet. The joints are required to have resistance below 4 nOhm at 45 kA at 4.5 K. The US ITER Project Office developed two different types of interpancake joints with some variations in details in order to find a better design, qualify the joints, and establish a fabrication process. We built and tested four samples of the sintered joints and two samples with butt-bonded joints (a total of eight joints). Both designs met the specifications. Results of the joint development, test results, and selection of the baseline design are presented and discussed in the paper.

Martovetsky, Nicolai N [ORNL; Berryhill, Adam B [Cryomagnetics, Inc.; Kenney, Steven J [ORNL

2012-01-01T23:59:59.000Z

187

Engineering and manufacturing of ITER first mirror mock-ups  

SciTech Connect

Most of the ITER optical diagnostics aiming at viewing and monitoring plasma facing components will use in-vessel metallic mirrors. These mirrors will be exposed to a severe plasma environment and lead to an important tradeoff on their design and manufacturing. As a consequence, investigations are carried out on diagnostic mirrors toward the development of optimal and reliable solutions. The goals are to assess the manufacturing feasibility of the mirror coatings, evaluate the manufacturing capability and associated performances for the mirrors cooling and polishing, and finally determine the costs and delivery time of the first prototypes with a diameter of 200 and 500 mm. Three kinds of ITER candidate mock-ups are being designed and manufactured: rhodium films on stainless steel substrate, molybdenum on TZM substrate, and silver films on stainless steel substrate. The status of the project is presented in this paper.

Joanny, M.; Travere, J. M.; Salasca, S.; Corre, Y. [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); Marot, L. [Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland); Thellier, C.; Gallay, G.; Cammarata, C.; Passier, B.; Ferme, J. J. [SESO, 305 Rue Louis Armand CS 30504, 13593 Aix-en-Provence Cedex 3 (France)

2010-10-15T23:59:59.000Z

188

Iterative Entanglement Distillation: Approaching full Elimination of Decoherence  

E-Print Network (OSTI)

The distribution and processing of quantum entanglement form the basis of quantum communication and quantum computing. The realization of the two is difficult because quantum information inherently has a high susceptibility to decoherence, i.e. to uncontrollable information loss to the environment. For entanglement distribution, a proposed solution to this problem is capable of fully eliminating decoherence; namely iterative entanglement distillation. This approach builds on a large number of distillation steps each of which extracts a number of weakly decohered entangled states from a larger number of strongly decohered states. Here, for the first time, we experimentally demonstrate iterative distillation of entanglement. Already distilled entangled states were further improved in a second distillation step and also made available for subsequent steps.Our experiment displays the realization of the building blocks required for an entanglement distillation scheme that can fully eliminate decoherence.

Boris Hage; Aiko Samblowski; James DiGuglielmo; Jaromír Fiurášek; Roman Schnabel

2010-07-09T23:59:59.000Z

189

US ITER is a strong contributor in plan to enhance international sharing of  

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

US ITER is a strong contributor in plan to enhance international sharing of US ITER is a strong contributor in plan to enhance international sharing of prime ITER real estate By Lynne Degitz, US ITER March 28, 2013 Tweet Widget Facebook Like Google Plus One PPPL's Russell Feder, left, and David Johnson developed key features for a modular approach to housing the extensive diagnostic systems that will be installed on the ITER tokamak. (Photo by Elle Starkman/PPPL Office of Communications) PPPL's Russell Feder, left, and David Johnson developed key features for a modular approach to housing the extensive diagnostic systems that will be installed on the ITER tokamak. Gallery: Diagram of an equatorial port plug shows the three vertical diagnostic shield modules with detachable first wall blocks. The modular approach has many advantages including efficient design collaboration, easier maintenance and the possibility for future upgrades to the ITER diagnostic systems.

190

An Iterative, Dynamically Stabilized(IDS) Method of Data Unfolding  

E-Print Network (OSTI)

We describe an iterative unfolding method for experimental data, making use of a regularization function. The use of this function allows one to build an improved normalization procedure for Monte Carlo spectra, unbiased by the presence of possible new structures in data. We unfold, in a dynamically stable way, data spectra which can be strongly affected by fluctuations in the background subtraction and simultaneously reconstruct structures which were not initially simulated.

Bogdan Malaescu

2011-06-15T23:59:59.000Z

191

Iterative procedure for computing accessible information in quantum communication  

E-Print Network (OSTI)

We present an iterative algorithm that finds the optimal measurement for extracting the accessible information in any quantum communication scenario. The maximization is achieved by a steepest-ascent approach toward the extremal point, following the gradient uphill in sufficiently small steps. We apply it to a simple ad-hoc example, as well as to a problem with a bearing on the security of a tomographic protocol for quantum key distribution.

Jaroslav ?ehá?ek; Berthold-Georg Englert; Dagomir Kaszlikowski

2004-08-20T23:59:59.000Z

192

Progress on the heating and current drive systems for ITER  

SciTech Connect

The electron cyclotron (EC), ion cyclotron (IC), heating-neutral beam (H-NB) and, although not in the day 1 baseline, lower hybrid (LH) systems intended for ITER have been reviewed in 2007/2008 in light of progress of physics and technology in the field. Although the overall specifications are unchanged, notable changes have been approved. Firstly, it has been emphasized that the H&CD systems are vital for the ITER programme. Consequently, the full 73 MW should be commissioned and available on a routine basis before the D/T phase. Secondly, significant changes have been approved at system level, most notably: the possibility to operate the heating beams at full power during the hydrogen phase requiring new shine through protection; the possibility to operate IC with 2 antennas with increased robustness (no moving parts); the possible increase to 2 MW of key components of the EC transmission systems in order to provide an easier upgrading of the EC power as may be required by the project; the addition of a building dedicated to the RF power sources and to a testing facility for acceptance of diagnostics and heating port plugs. Thirdly, the need of a plan for developing, in time for the active phase, a CD system such as LH suitable for very long pulse operation of ITER was recognised. The review describes these changes and their rationale.

Jacquinot, J. [CEA, Cadarache, France; Beaumont, Bertrand [ITER Joint Work Site, Cadarache; Bora, D. [ITER Joint Work Site, Cadarache; Campbell, D. [ITER Joint Work Site, Cadarache; Darbos, Caroline [ITER Joint Work Site, Cadarache; Decamps, H. [ITER Organization, Saint Paul Lez Durance, France; Graceffa, J. [ITER Joint Work Site, Cadarache; Gassmann, T. [ITER Joint Work Site, Cadarache; Hemsworth, R. [ITER Joint Work Site, Cadarache; Henderson, Mark [ITER Joint Work Site, Cadarache; Kobayashi, N. [ITER Joint Work Site, Cadarache; Lamalle, Philippe [ITER Joint Work Site, Cadarache; Schunke, B. [ITER Joint Work Site, Cadarache; Tanaka, M. [ITER Joint Work Site, Cadarache; Tanga, A. [ITER Joint Work Site, Cadarache; Albajar, F. [Fusion for Energy (F4E), Barcelona, Spain; Bonicelli, T. [Fusion for Energy (F4E), Barcelona, Spain; Saibene, G. [Fusion for Energy (F4E), Barcelona, Spain; Sartori, R. [Fusion for Energy (F4E), Barcelona, Spain; Becoulet, A. [CEA, Cadarache, France; Hoang, G. T. [CEA, Cadarache, France; Inoue, T. [Japan Atomic Energy Agency (JAEA), Naka; Sakamoto, K. [Japan Atomic Energy Agency (JAEA), Naka; Takahashi, K. [Japan Atomic Energy Agency (JAEA), Naka; Watanabe, K. [Japan Atomic Energy Agency (JAEA), Naka; Goulding, Richard Howell [ORNL; Rasmussen, David A [ORNL; Swain, David W [ORNL; Chakraborty, A. [ITER India - Bhat, Gandhinagar, Gujarat; Mukherjee, A. [ITER India - Bhat, Gandhinagar, Gujarat; Rao, S. L. [ITER India - Bhat, Gandhinagar, Gujarat; Denisov, G. [Russian Academy of Science, Novgorod, Russia; Nightingale, M. [EURATOM / UKAEA, Abingdon, UK; Sonato, P. [EURATOM / ENEA, Italy

2009-06-01T23:59:59.000Z

193

Simulations of plasma behavior during pellet injection in ITER  

SciTech Connect

Plasma behavior during pellet injection in ITER is investigated using a 1.5D BALDUR integrated predictive modeling code. In these simulations, the pellet ablation is described using the neutral gas shielding (NGS) model developed by Parks and Turnbull [Phys. Fluids 21, 1735 (1978)]. The NGS pellet ablation model that includes the {nabla}B drift effect is coupled with a plasma core transport model, which is a combination of an MMM95 anomalous transport model and an NCLASS neoclassical transport model. The combination of core transport models, together with pellet model, is used to simulate the time evolution of plasma current, ion and electron temperatures, and density profiles for ITER standard type-I ELMy H-mode discharges during the pellet injection. It is found that the injection of pellet can result in either enhancement or degradation of plasma performance. The {nabla}B drift effect on the pellet deposition is very strong in ITER. The plasma density with high field side pellets, which favorable with the {nabla}B drift effect, is much higher and pellet can penetrate much deeper than that with low field side pellets.

Klaywittaphat, P., E-mail: thawatchai@siit.tu.ac.th; Onjun, T. [Thammasat University, School of Manufacturing Systems and Mechanical Engineering, Sirindhorn International Institute of Technology (Thailand)

2012-06-15T23:59:59.000Z

194

Iterated amplitudes in the high-energy limit  

E-Print Network (OSTI)

We consider the high-energy limits of the colour ordered four-, five- and six-gluon MHV amplitudes of the maximally supersymmetric QCD in the multi-Regge kinematics where all the gluons are strongly ordered in rapidity. We show that various building blocks occurring in the Regge factorisation (the Regge trajectory, the coefficient functions and the Lipatov vertex) satisfy an iterative structure very similar to the Bern-Dixon-Smirnov (BDS) ansatz. This iterative structure, combined with the universality of the building blocks, enables us to show that in the Euclidean region any two- and three-loop amplitude in multi-Regge kinematics is guaranteed to satisfy the BDS ansatz. We also consider slightly more general kinematics where the strong rapidity ordering applies to all the gluons except the two with either the largest or smallest rapidities, and we derive the iterative formula for the associated coefficient function. We show that in this kinematic limit the BDS ansatz is also satisfied. Finally, we argue that only for more general kinematics - e.g. with three gluons having similar rapidities, or where the two central gluons have similar rapidities - can a disagreement with the BDS ansatz arise.

V. Del Duca; C. Duhr; E. W. N. Glover

2008-09-10T23:59:59.000Z

195

Soft Error Vulnerability of Iterative Linear Algebra Methods  

Science Conference Proceedings (OSTI)

Devices become increasingly vulnerable to soft errors as their feature sizes shrink. Previously, soft errors primarily caused problems for space and high-atmospheric computing applications. Modern architectures now use features so small at sufficiently low voltages that soft errors are becoming significant even at terrestrial altitudes. The soft error vulnerability of iterative linear algebra methods, which many scientific applications use, is a critical aspect of the overall application vulnerability. These methods are often considered invulnerable to many soft errors because they converge from an imprecise solution to a precise one. However, we show that iterative methods can be vulnerable to soft errors, with a high rate of silent data corruptions. We quantify this vulnerability, with algorithms generating up to 8.5% erroneous results when subjected to a single bit-flip. Further, we show that detecting soft errors in an iterative method depends on its detailed convergence properties and requires more complex mechanisms than simply checking the residual. Finally, we explore inexpensive techniques to tolerate soft errors in these methods.

Bronevetsky, G; de Supinski, B

2007-12-15T23:59:59.000Z

196

Reformulation of nonlinear integral magnetostatic equations for rapid iterative convergence  

SciTech Connect

The integral equations of magnetostatics, conventionally given in terms of the field variables M and H, are reformulated with M and B. Stability criteria and convergence rates of the eigenvectors of the linear iteration matrices are evaluated. The relaxation factor ..beta.. in the MH approach varies inversely with permeability ..mu.., and nonlinear problems with high permeability converge slowly. In contrast, MB iteration is stable for ..beta.. < 2, and nonlinear problems converge rapidly, at a rate essentially independent of ..mu... For a permeability of 10/sup 3/, the number of iterations is reduced by two orders of magnitude over the conventional method, and at higher permeabilities the reduction is proportionally greater. The dependence of MB convergence rate on ..beta.., degree of saturation, element aspect ratio, and problem size is found numerically. An analytical result for the MB convergence rate for small nonlinear problems is found to be accurate for ..beta..less than or equal to1.2. The results are generally valid for two- and three-dimensional integral methods and are independent of the particular discretization procedures used to compute the field matrix.

Bloomberg, D.S.; Castelli, V.

1985-03-01T23:59:59.000Z

197

Geothermal heat cycle research: Supercritical cycle with horizontal counterflow condenser  

DOE Green Energy (OSTI)

The Heat Cycle Research Program, which is being conducted for the Department of Energy, has as its objective the development of the technology for effecting the improved utilization of moderate temperature geothermal resources. To meet this objective, the program has as one of its goals to improve the performance of geothermal binary cycles to levels approaching the practicable thermodynamic maximum. In pursuit of this goal, tests are being conducted at the Heat Cycle Research Facility located at the DOE Geothermal Test Facility, East Mesa, California. The current testing involves the investigation of binary power cycle performance utilizing mixtures of non-adjacent hydrocarbons as the working fluids, with supercritical vaporization and in-tube condensation of the working fluid. In addition to the present test program, preparations are being made to investigate the binary cycle performance improvements which can be achieved by allowing supersaturated vapor expansions in the turbine. These efforts are anticipated to verify that through the utilization of these advanced power cycle concepts and allowing the supersaturated turbine expansions, improvements of up to 28% in the net geofluid effectiveness (net watt hours plant output per pound of geofluid) over conventional binary power plants can be achieved. Results are presented for the recent testing including those tests examining the performance of the countercurrent condenser at different tube inclinations. Performance of the heaters and the condenser in a vertical orientation can be predicted well with existing methods and data. The condenser in its near horizontal orientation performs slightly worse than in its vertical orientation. Some problems have been encountered in predicting the performance in the horizontal orientation. There is no evidence of departure from integral condensation in either orientation.

Mines, G.L.; Swank, W.D.; Bliem, C.J.

1987-01-01T23:59:59.000Z

198

Quantifying Carbon Cycle Feedbacks  

Science Conference Proceedings (OSTI)

Perturbations to the carbon cycle could constitute large feedbacks on future changes in atmospheric CO2 concentration and climate. This paper demonstrates how carbon cycle feedback can be expressed in formally similar ways to climate feedback, ...

J. M. Gregory; C. D. Jones; P. Cadule; P. Friedlingstein

2009-10-01T23:59:59.000Z

199

Edgeworth cycles revisited  

E-Print Network (OSTI)

Some gasoline markets exhibit remarkable price cycles, where price spikes are followed by a series of small price declines: a pattern consistent with a model of Edgeworth cycles described by Maskin and Tirole. We extend ...

Doyle, Joseph J.

200

International Nuclear Fuel Cycle Fact Book  

Science Conference Proceedings (OSTI)

As the US Department of Energy (DOE) and DOE contractors have become increasingly involved with other nations in nuclear fuel cycle and waste management cooperative activities, a need has developed for a ready source of information concerning foreign fuel cycle programs, facilities, and personnel. This Fact Book was compiled to meet that need. The information contained in the International Nuclear Fuel Cycle Fact Book has been obtained from many unclassified sources: nuclear trade journals and newsletters; reports of foreign visits and visitors; CEC, IAEA, and OECN/NEA activities reports; not reflect any one single source but frequently represent a consolidation/combination of information.

Leigh, I.W.; Patridge, M.D.

1991-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "involves iterative cycling" 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

Open-cycle absorption cooling using packed-bed absorbent reconcentration  

DOE Green Energy (OSTI)

The technical feasibility of a lithium chloride open-cycle absorption air conditioner using solar-heated air for reconcentration of the absorbent solution is examined. In contrast to a successfully operating Soviet design (in which absorbent reconcentration is accomplished by trickling the solution across a sloping black roof exposed to the sun), this study involves a packed-bed concentrator. Solar-heated air reconcentrates the solution by vaporizing water (the refrigerant) from the solution in the packed bed, enabling the system to be incorporated into a conventional solar air heating system and avoiding numerous problems associated with the roof concentrator. A thermodynamic analysis provides the criteria for the design of the packed bed. Heat and mass transfer processes occurring simultaneously in the bed are modeled using an iterative technique with the aid of a digital computer. The size of the packed-bed required to reconcentrate the absorbent solution at a rate corresponding to 10,550 W of cooling is determined, using flow rates, temperatures, and humidities typical of residential solar air-heating systems. Based on these results, the system air conditioning capability with solar energy input is predicted over the course of a clear summer day for Fort Collins, Colorado, and St. Louis, Missouri. Sufficient cooling capacity to meet a 10,550 W peak load using a 70 m/sup 2/ flatplate collector array is predicted by the model for both locations.

Leboeuf, C. M.; Loef, G. O.G.

1980-05-01T23:59:59.000Z

202

The Manuel Lujan Jr. Neutron Scattering Center (LANSCE) experiment reports 1993 run cycle. Progress report  

Science Conference Proceedings (OSTI)

This year the Manuel Lujan Jr. Neutron Scattering Center (LANSCE) ran an informal user program because the US Department of Energy planned to close LANSCE in FY1994. As a result, an advisory committee recommended that LANSCE scientists and their collaborators complete work in progress. At LANSCE, neutrons are produced by spallation when a pulsed, 800-MeV proton beam impinges on a tungsten target. The proton pulses are provided by the Clinton P. Anderson Meson Physics Facility (LAMPF) accelerator and a associated Proton Storage Ring (PSR), which can Iter the intensity, time structure, and repetition rate of the pulses. The LAMPF protons of Line D are shared between the LANSCE target and the Weapons Neutron Research (WNR) facility, which results in LANSCE spectrometers being available to external users for unclassified research about 80% of each annual LAMPF run cycle. Measurements of interest to the Los Alamos National Laboratory (LANL) may also be performed and may occupy up to an additional 20% of the available beam time. These experiments are reviewed by an internal program advisory committee. This year, a total of 127 proposals were submitted. The proposed experiments involved 229 scientists, 57 of whom visited LANSCE to participate in measurements. In addition, 3 (nuclear physics) participating research teams, comprising 44 scientists, carried out experiments at LANSCE. Instrument beam time was again oversubscribed, with 552 total days requested an 473 available for allocation.

Farrer, R.; Longshore, A. [comps.

1995-06-01T23:59:59.000Z

203

Cycle to Cycle Manufacturing Process Control  

E-Print Network (OSTI)

Most manufacturing processes produce parts that can only be correctly measured after the process cycle has been completed. Even if in-process measurement and control is possible, it is often too expensive or complex to ...

Hardt, David E.

204

U.S.Statements on International Fusion Reactor (ITER) Siting Decision |  

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

U.S.Statements on International Fusion Reactor (ITER) Siting U.S.Statements on International Fusion Reactor (ITER) Siting Decision U.S.Statements on International Fusion Reactor (ITER) Siting Decision June 28, 2005 - 1:45pm Addthis WASHINGTON, DC - Today in Moscow, Russia, the ministers representing the six ITER parties, including Dr. Raymond L. Orbach, Director of the U.S. Department of Energy's Office of Science, announced the ITER international fusion reactor will be located at the EU site in Cadarache, France. Below are statements by U.S. government officials following the signing of the agreement at the Ministerial Meeting. The text of the announcement by the six parties is available at www.iter.org/index_newsroom.htm. Statement by U.S. Secretary of Energy Samuel W. Bodman: "Plentiful, reliable energy is critical to continued worldwide economic

205

Time parallelization of advanced operation scenario simulations of ITER plasma  

Science Conference Proceedings (OSTI)

This work demonstrates that simulations of advanced burning plasma operation scenarios can be successfully parallelized in time using the parareal algorithm. CORSICA - an advanced operation scenario code for tokamak plasmas is used as a test case. This is a unique application since the parareal algorithm has so far been applied to relatively much simpler systems except for the case of turbulence. In the present application, a computational gain of an order of magnitude has been achieved which is extremely promising. A successful implementation of the Parareal algorithm to codes like CORSICA ushers in the possibility of time efficient simulations of ITER plasmas.

Samaddar, D. [ITER Organization, Saint Paul Lez Durance, France; Casper, T. A. [Lawrence Livermore National Laboratory (LLNL); Kim, S. H. [ITER Organization, Saint Paul Lez Durance, France; Berry, Lee A [ORNL; Elwasif, Wael R [ORNL; Batchelor, Donald B [ORNL; Houlberg, Wayne A [ORNL

2013-01-01T23:59:59.000Z

206

An iterative, dynamically stabilized method of data unfolding  

E-Print Network (OSTI)

We propose a new iterative unfolding method for experimental data, making use of a regularization function. The use of this function allows one to build an improved normalization procedure for Monte Carlo spectra, unbiased by the presence of possible new structures in data. We are able to unfold, in a dynamically stable way, data spectra which can be strongly affected by fluctuations in the background subtraction and simultaneously reconstruct structures which were not initially simulated. This method also allows one to control the amount of correlations introduced between the bins of the unfolded spectrum, when the transfers of events correcting the systematic detector effects are performed.

Bogdan Malaescu

2009-07-22T23:59:59.000Z

207

Volkov solution for two laser beams and ITER  

E-Print Network (OSTI)

We find the solution of the Dirac equation for two plane waves (laser beams) and we determine the modified Compton formula for the scattering of two photons on an alectron. The practical meaning of the two laser beams is, that two laser beams impinging on a targed which is constituted from material in the form of a foam, can replace 100-200 laser beams impinging on a normal targed. It means that the nuclear fusion with two laser beams is realistic in combination with the nuclear reactor such as ITER.

Miroslav Pardy

2005-07-12T23:59:59.000Z

208

Analysis of the ITER LFS Reflectometer Transmission Line System  

Science Conference Proceedings (OSTI)

A critical issue in the design of the ITER Low Field Side (LFS) reflectometer is the transmission line (TL) system. A TL connects each launcher to a diagnostic instrument. Each TL will typically consist of ~42 m of corrugated waveguide and up to 10 miter bends. Important issues for the performance of the TL system are mode conversion and reflections. Minimizing mode conversion and reflections in the waveguide are critical to minimizing standing waves and phase errors in the reflectometer-measured phase. The performance of the corrugated waveguide and miter bends is analyzed and recommendations given.

Hanson, Gregory R [ORNL; Wilgen, John B [ORNL; Bigelow, Tim S [ORNL; Diem, Stephanie J [ORNL; Biewer, Theodore M [ORNL

2010-01-01T23:59:59.000Z

209

Volkov solution for two laser beams and ITER  

E-Print Network (OSTI)

We find the solution of the Dirac equation for two plane waves (laser beams) and we determine the modified Compton formula for the scattering of two photons on an alectron. The practical meaning of the two laser beams is, that two laser beams impinging on a targed which is constituted from material in the form of a foam, can replace 100-200 laser beams impinging on a normal targed. It means that the nuclear fusion with two laser beams is realistic in combination with the nuclear reactor such as ITER.

Pardy, M

2006-01-01T23:59:59.000Z

210

Implementing the Gaia Astrometric Global Iterative Solution (AGIS) in Java  

E-Print Network (OSTI)

This paper provides a description of the Java software framework which has been constructed to run the Astrometric Global Iterative Solution for the Gaia mission. This is the mathematical framework to provide the rigid reference frame for Gaia observations from the Gaia data itself. This process makes Gaia a self calibrated, and input catalogue independent, mission. The framework is highly distributed typically running on a cluster of machines with a database back end. All code is written in the Java language. We describe the overall architecture and some of the details of the implementation.

O'Mullane, William; Lindegren, Lennart; Hernandez, Jose; Hobbs, David

2011-01-01T23:59:59.000Z

211

PROPERTY CHANGES OF CYANATE ESTER/EPOXY INSULATION SYSTEMS CAUSED BY AN ITER-LIKE DOUBLE IMPREGNATION AND BY REACTOR IRRADIATION  

Science Conference Proceedings (OSTI)

Because of the double pancake design of the ITER TF coils the insulation will be applied in several steps. As a consequence, the conductor insulation as well as the pancake insulation will undergo multiple heat cycles in addition to the initial curing cycle. In particular the properties of the organic resin may be influenced, since its heat resistance is limited. Two identical types of sample consisting of wrapped R-glass/Kapton layers and vacuum impregnated with a cyanate ester/epoxy blend were prepared. The build-up of the reinforcement was identical for both insulation systems; however, one system was fabricated in two steps. In the first step only one half of the reinforcing layers was impregnated and cured. Afterwards the remaining layers were wrapped onto the already cured system, before the resulting system was impregnated and cured again. The mechanical properties were characterized prior to and after irradiation to fast neutron fluences of 1 and 2x10{sup 22} m{sup -2}(E>0.1 MeV) in tension and interlaminar shear at 77 K. In order to simulate the pulsed operation of ITER, tension-tension fatigue measurements were performed in the load controlled mode. The results do not show any evidence for reduced mechanical strength caused by the additional heat cycle.

Prokopec, R.; Humer, K.; Fillunger, H.; Maix, R. K.; Weber, H. W. [Atominstitut, Vienna University of Technology, 1020 Wien (Austria)

2010-04-08T23:59:59.000Z

212

Object Delineation in Noisy Images by a Modified Policy-Iteration Method  

Science Conference Proceedings (OSTI)

The contours of isolated objects in noisy images may be detected with a minimal cost contour detection algorithm. An algorithm that is based on the policy-iteration method for locating the closed minimal cost path is introduced. Computational results ... Keywords: closed minimal cost path, cost coefficient matrix, iterative methods, noisy images, object delineation, optimisation, pattern recognition, picture processing, policy-iteration method, scintigraphic images

Adrie C. M. Dumay; Mariëlle N. A. J. Claessens; Cees Roos; Jan J. Gerbrands; Johan H. C. Reiber

1992-09-01T23:59:59.000Z

213

An iterative method for extreme optics of two-level systems  

E-Print Network (OSTI)

We formulate the problem of a two-level system in a linearly polarized laser field in terms of a nonlinear Riccati-type differential equation and solve the equation analytically in time intervals much shorter than half the optical period. The analytical solutions for subsequent intervals are then stuck together in an iterative procedure to cover the scale time of the laser pulse. This approach is applicable to pulses of arbitrary (nonrelativistic) strengths, shapes and durations, thus covering the whole region of light-matter couplings from weak through moderate to strong ones. The method allows quick insight into different problems from the field of light--matter interaction. Very good quality of the method is shown by recovering with it a number of subtle effects met in earlier numerically calculated photon-emission spectra from model molecular ions, double quantum wells, atoms and semiconductors. The method presented is an efficient mathematical tool to describe novel effects in the region of, e.g., extreme nonlinear optics, i.e., when two--level systems are exposed to pulses of only a few cycles in duration and strength ensuring the Rabi frequency to approach and even exceed the laser light frequence.

R. Parzynski; M. Sobczak; A. Plucinska

2004-07-18T23:59:59.000Z

214

Cryogenic Conduction Cooling Test of Removable Panel Mock-Up for ITER Cryostat Thermal Shield  

Science Conference Proceedings (OSTI)

ITER / Proceedings of the Twentieth Topical Meeting on the Technology of Fusion Energy (TOFE-2012) (Part 1), Nashville, Tennessee, August 27-31, 2012

K. Nam et al.

215

FILM COOLING CALCULATIONS WITH AN ITERATIVE CONJUGATE HEAT TRANSFER APPROACH USING EMPIRICAL HEAT TRANSFER COEFFICIENT CORRECTIONS.  

E-Print Network (OSTI)

??An iterative conjugate heat transfer technique was developed and automated to predict the temperatures on film cooled surfaces such as flat plates and turbine blades.… (more)

Dhiman, Sushant

2010-01-01T23:59:59.000Z

216

Status of Design and R&D for ITER Blanket in Korea  

Science Conference Proceedings (OSTI)

ITER / Proceedings of the Twentieth Topical Meeting on the Technology of Fusion Energy (TOFE-2012) (Part 1), Nashville, Tennessee, August 27-31, 2012

Duck-Hoi Kim et al.

217

Iterated and irreducible pion-photon exchange in nuclei  

E-Print Network (OSTI)

We calculate the contribution to the nuclear energy density functional which arises from iterated pion-photon exchange between nucleons. In heavy nuclei, this novel charge symmetry breaking interaction leads to an additional binding of each proton by about 0.2 MeV. Compared to that the analogous effect from irreducible pion-photon exchange is negligibly small. As a possible mechanism to resolve the Nolen-Schiffer anomaly we propose the iteration of one-photon exchange with an attractive short-range NN-interaction. The corresponding energy per proton reads: $\\bar E[\\rho_p]=(2\\alpha/15\\pi^2)(\\pi^2 -3+6 \\ln2) {\\cal A}_{pp} k_p^2$ with $\\rho_p =k_p^3/ 3\\pi^2$ the proton density and ${\\cal A}_{pp}\\approx 2 $fm an effective (in-medium) scattering length. Hints for such a value of ${\\cal A}_{pp}$ come from phenomenological Skyrme forces and from the neutron matter equation of state.

N. Kaiser

2003-12-16T23:59:59.000Z

218

Axisymmetric Simulations of the ITER Vertical Stability Coil  

SciTech Connect

The ITER in-vessel coil system includes Vertical Stability (VS) coils and Edge Localized Mode (ELM) coils. There are two large VS ring coils, one upper and one lower. Each has four turns which are independently connected. The VS coils are needed for successful operation of ITER for most all of its operating modes. The VS coils must be highly reliable and fault tolerant. The operating environment includes normal and disruption Lorentz forces. To parametrically address all these design conditions in a tractable analysis requires a simplified model. The VS coils are predominately axisymmetric, and this suggests that an axisymmetric model can be meaningfully used to address the variations in mechanical design, loading, material properties, and time dependency. The axisymmetric finite element analysis described in this paper includes simulations of the bolted frictional connections used for the mounting details. Radiation and elastic-plastic response are modeled particularly for the extreme faulted conditions. Thermal connectivity is varied to study the effects of partial thermal connection of the actively cooled conductor to the remaining structure.

Titus, Peter H.

2013-07-09T23:59:59.000Z

219

Thermo-mechanical analysis of ITER first mirrors and its use for the ITER equatorial visible/infrared wide angle viewing system optical design  

SciTech Connect

ITER first mirrors (FMs), as the first components of most ITER optical diagnostics, will be exposed to high plasma radiation flux and neutron load. To reduce the FMs heating and optical surface deformation induced during ITER operation, the use of relevant materials and cooling system are foreseen. The calculations led on different materials and FMs designs and geometries (100 mm and 200 mm) show that the use of CuCrZr and TZM, and a complex integrated cooling system can limit efficiently the FMs heating and reduce their optical surface deformation under plasma radiation flux and neutron load. These investigations were used to evaluate, for the ITER equatorial port visible/infrared wide angle viewing system, the impact of the FMs properties change during operation on the instrument main optical performances. The results obtained are presented and discussed.

Joanny, M.; Salasca, S.; Dapena, M.; Cantone, B.; Travere, J. M. [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); Thellier, C.; Ferme, J. J. [THALES SESO, 13593 Aix-en-Provence Cedex 3 (France); Marot, L. [Department of Physics, University of Basel, 4056 Basel (Switzerland); Buravand, O. [Institut d'Optique Graduate School, 91127 Palaiseau (France); Perrollaz, G. [AMETRA, 13770 Venelles (France); Zeile, C. [INR, KIT, D-76344 Eggenstein-Leopoldshafen (Germany)

2012-10-15T23:59:59.000Z

220

Duty Cycle Software  

Duty cycles capture the influence of one variable in relations to the whole system. This allows for analysis in determining the impact of new ...

Note: This page contains sample records for the topic "involves iterative cycling" 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

Nuclear fuel cycle costs  

Science Conference Proceedings (OSTI)

The costs for the back-end of the nuclear fuel cycle, which were developed as part of the Nonproliferation Alternative Systems Assessment Program (NASAP), are presented. Total fuel cycle costs are given for the pressurized water reactor once-through and fuel recycle systems, and for the liquid-metal fast breeder reactor system. These calculations show that fuel cycle costs are a small part of the total power costs. For breeder reactors, fuel cycle costs are about half that of the present once-through system. The total power cost of the breeder reactor system is greater than that of light-water reactor at today's prices for uranium and enrichment.

Burch, W.D.; Haire, M.J.; Rainey, R.H.

1982-02-01T23:59:59.000Z

222

Cycles in fossil diversity  

E-Print Network (OSTI)

Transitions in Global Marine Diversity, Science 281, 1157-know if this cycle is a variation in true diversity or onlyin observed diversity, but either case requires explanation

Rohde, Robert A.; Muller, Richard A.

2004-01-01T23:59:59.000Z

223

Proposal of an Arc Detection Technique Based on RF Measurements for the ITER ICRF Antenna  

SciTech Connect

RF arc detection is a key operational and safety issue for the ICRF system on ITER. Indeed the high voltages inside the antenna put it at risk of arcing, which could cause substantial damage. This paper describes the various possibilities explored by circuit simulation and the strategy now considered to protect the ITER ICRF antenna from RF arcs.

Huygen, S.; Dumortier, P.; Durodie, F.; Messiaen, A.; Vervier, M.; Vrancken, M. [LPP/ERM-KMS, Association EURATOM-Belgian State, Brussels (Belgium); Wooldridge, E. [EURATOM/CCFE Fusion Association, Culham Science Centre (United Kingdom)

2011-12-23T23:59:59.000Z

224

Iterative Solutions for Low Lying Excited States of a Class of Schroedinger Equation  

E-Print Network (OSTI)

The convergent iterative procedure for solving the groundstate Schroedinger equation is extended to derive the excitation energy and the wave function of the low-lying excited states. The method is applied to the one-dimensional quartic potential problem. The results show that the iterative solution converges rapidly when the coupling $g$ is not too small.

R. Friedberg; T. D. Lee; W. Q. Zhao

2006-07-12T23:59:59.000Z

225

Iterative Solution for Generalized Sombrero-shaped Potential in $N$-dimensional Space  

E-Print Network (OSTI)

An explicit convergent iterative solution for the lowest energy state of the Schroedinger equation with generalized $N$-dimensional Sombrero-shaped potential is presented. The condition for the convergence of the iteration procedure and the dependence of the shape of the groundstate wave function on the parameters are discussed.

W. Q. Zhao

2007-12-25T23:59:59.000Z

226

FPA 30 year Anniversary Meeting, Washington, 2 December 2009 Slide 1 Status of ITER  

E-Print Network (OSTI)

Principal Deputy Director General of the ITER Organization #12;FPA 30 year Anniversary Meeting, Washington Operation Present HQ Building To Aix #12;FPA 30 year Anniversary Meeting, Washington, 2 December 2009 Slide Organization ~440 people by end 2009 · Another 450-500 people in the DAs working on ITER · IO and DA's started

227

Attachment to Joint Declaration of the Ministerial Meeting for ITER Moscow, 28th  

E-Print Network (OSTI)

Attachment to Joint Declaration of the Ministerial Meeting for ITER Moscow, 28th June 2005 Joint will be decided jointly, based upon the wishes of the non-Host as long as this serves the goal of promoting 5 May 2005 #12;Attachment to Joint Declaration of the Ministerial Meeting for ITER Moscow, 28th June

228

A three-dimensional adaptive method based on the iterative grid redistribution  

E-Print Network (OSTI)

such as fluid dynamics, combustion and heat transfer and others, the required density of grid pointsA three-dimensional adaptive method based on the iterative grid redistribution Desheng Wang on iterative grid redistribution technique introduced in [J. Comput. Phys. 159 (2000) 246]. The key step

Wang, Xiao-Ping

229

Performance Parameters and Development Status of ECH Transmission Line Components Suitable for ITER (A24394)  

E-Print Network (OSTI)

IAEA Technical Committee Meeting On Electron Cyclotron Resonance Heating Physics And Technology For ITER, Kloster Seeon, Germany, 2003, To Be Published In The ProceedingsIAEA Technical Committee Meeting on Electron Cyclotron Resonance Heating Physics and Technology for ITER Kloster Seeon, DE, 2003999610360

Olstad, R.A.

2003-07-14T23:59:59.000Z

230

Considerations of Selection of ECH System Transmission Line Waveguide Diameter for ITER (A25121)  

E-Print Network (OSTI)

Proc. 3rd Tech. Mtg On Electron Cyclotron Resonanxe Heating Physics And Technology For ITER, Como, Italy, 2005; General Atomics Report GA-A25121 (2005)3rd Technical Meeting on Electron Cyclotron Resonance Heating Physics and Technology for ITER Como, IT, 2005999610860

Olstad, R.A.

2005-07-07T23:59:59.000Z

231

Increasing the Locality of Iterative Methods and Its Application to the Simulation of Semiconductor Devices  

Science Conference Proceedings (OSTI)

Irregular codes are present in many scientific applications, such as finite element simulations. In these simulations the solution of large sparse linear equation systems is required, which are often solved using iterative methods. The main kernel of ... Keywords: data locality, irregular codes, iterative methods, reordering techniques, semiconductor devices simulation

J.C. Pichel; D.B. Heras; J.C. Cabaleiro; A.J. García-Loureiro; F.F. Rivera

2010-05-01T23:59:59.000Z

232

An iterative stochastic ensemble method for parameter estimation of subsurface flow models  

Science Conference Proceedings (OSTI)

Parameter estimation for subsurface flow models is an essential step for maximizing the value of numerical simulations for future prediction and the development of effective control strategies. We propose the iterative stochastic ensemble method (ISEM) ... Keywords: Iterative stochastic ensemble method, Parameter estimation, Regularization, Subsurface flow models

Ahmed H. Elsheikh, Mary F. Wheeler, Ibrahim Hoteit

2013-06-01T23:59:59.000Z

233

A fast iterative solver for the variable coefficient diffusion equation on a disk  

Science Conference Proceedings (OSTI)

We present an efficient iterative method for solving the variable coefficient diffusion equation on a unit disk. The equation is written in polar coordinates and is discretized by the standard centered difference approximation under the grid arrangement ... Keywords: Ginzburg-Landau vortices, iterative method, polar coordinates, variable diffusion equation

Ming-Chih Lai; Yu-Hou Tseng

2005-09-01T23:59:59.000Z

234

Conceptual study on Flexible Guidance and Docking system for ITER Remote Handling  

E-Print Network (OSTI)

1 Conceptual study on Flexible Guidance and Docking system for ITER Remote Handling Transport Cask divertors and blanket modules from the Tokamak Building to the Hot Cell Building o Addressed topics for ITER Remote Handling Transport Cask o Publications from IST team: · Isabel Ribeiro, Pedro Lima, Pedro

Ribeiro,Isabel

235

Obligations Notification Cycle and New Obligations Presentation  

National Nuclear Security Administration (NNSA)

Obligations Notification Cycle and Obligations Notification Cycle and Obligations Notification Cycle and Obligations Notification Cycle and New Obligations New Obligations Bill Benton, DOE/SO-62 Pat Tana, NRC/NSIR Michelle Romano, NAC/NMMSS Obligations Accounting Implementation Workshop Obligations Accounting Implementation Workshop January 13, 2004 January 13, 2004 Crowne Crowne Plaza Plaza Ravinia Ravinia Atlanta, Georgia Atlanta, Georgia Notifications Notifications * There are issues! - Timeliness - Information (or lack thereof) - Other? * DOE Facilities - Bill Benton, 301-903-1150, Bill.Benton@hq.doe.gov * NRC Facilities - Pat Tana, 301-415-8105, pmt@nrc.gov * DOE/SO-62, NRC to request meeting of Government representatives involved. * DOE/SO-62, NRC to solicit concrete case studies to

236

Nuclear Fuel Cycle | Department of Energy  

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

Fuel Cycle Fuel Cycle Nuclear Fuel Cycle GC-52 provides legal advice to DOE regarding research and development of nuclear fuel and waste management technologies that meet the nation's energy supply, environmental, and energy security needs. GC-52 also advises DOE on issues involving support for international fuel cycle initiatives aimed at advancing a common vision of the necessity of the expansion of nuclear energy for peaceful purposes worldwide in a safe and secure manner. In addition, GC-52 provides legal advice to DOE regarding the management and disposition of excess uranium in DOE's uranium stockpile. GC-52 attorneys participate in meetings of DOE's Uranium Inventory Management Coordinating Committee and provide advice on compliance with statutory requirements for the sale or transfer of uranium.

237

Separations Needs for the Alternate Chemical Cycles  

DOE Green Energy (OSTI)

The bulk of the efforts for the development of a hydrogen production plant supported by the Nuclear Hydrogen Initiative (NHI) have been directed towards the sulfur-iodine (S-I) thermochemical cycle. However, it was judged prudent to re-investigate alternate chemical cycles in light of new developments and technical accomplishments derived from the current S-I work. This work analyzes the available data for the promising alternate chemical cycles to provide an understanding of their inherent chemical separations needs. None of the cycles analyzed have separations that are potential “show stoppers”; although some of the indicated separations will be challenging to perform. The majority of the separations involve processes that are either more achievable or more developed

Frederick F. Stewart

2007-05-01T23:59:59.000Z

238

On the Driving Mechanism of the Annual Cycle of the Florida Current Transport  

Science Conference Proceedings (OSTI)

The mechanisms involved in setting the annual cycle of the Florida Current transport are revisited using an adjoint model approach. Adjoint sensitivities of the Florida Current transport to wind stress reproduce a realistic seasonal cycle with an ...

Lars Czeschel; Carsten Eden; Richard J. Greatbatch

2012-05-01T23:59:59.000Z

239

Visions for Data Management and Remote Collaboration on ITER  

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

Transport And Density Peaking At Low Transport And Density Peaking At Low Collisionality On Alcator C-Mod 49 th Annual Meeting of APS - DPP Orlando, 11/14/2007 M. Greenwald, J.W. Hughes, D. Mikkelsen, J. Terry, Alcator Group C. Angioni, H. Weisen M. Greenwald, et al., APS-DPP November 2007 Particle Transport and Density Profiles ● We want to be able to predict density profile - Better fusion performance with moderate density peaking - Effects on stability, divertor operation etc. ● Results from ASDEX (Angioni et al., PRL 2003), JET (H. Weisen, et al., NF 2005) show increase in density peaking at low ν* for H-mode plasmas. - Central fueling (NBI) can play an important role as well. ● Scales to ITER (with weak fueling): n e (0)/ ~ 1.4-1.5 ● In this talk, we'll also look at an additional effect: the role of safety factor

240

Iterated Function System Models in Data Analysis: Detection and Separation  

E-Print Network (OSTI)

We investigate the use of iterated function system (IFS) models for data analysis. An IFS is a discrete dynamical system in which each time step corresponds to the application of one of a finite collection of maps. The maps, which represent distinct dynamical regimes, may act in some pre-determined sequence or may be applied in random order. An algorithm is developed to detect the sequence of regime switches under the assumption of continuity. This method is tested on a simple IFS and applied to an experimental computer performance data set. This methodology has a wide range of potential uses: from change-point detection in time-series data to the field of digital communications.

Zachary Alexander; Elizabeth Bradley; Joshua Garland; James D. Meiss

2011-08-15T23:59:59.000Z

Note: This page contains sample records for the topic "involves iterative cycling" 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

Iterative Structure of the N=4 SYM Spin Chain  

E-Print Network (OSTI)

We develop algebraic methods for finding loop corrections to the N=4 SYM dilatation generator, within the noncompact psu(1,1|2) sector. This sector gives a 't Hooft coupling lambda-dependent representation of psu(1,1|2) times psu(1|1)^2. At first working independently of the representation, we present an all-order algebraic ansatz for the lambda-dependence of this Lie algebra's generators. The ansatz solves the symmetry constraints if an auxiliary generator, h, satisfies certain simple commutation relations with the Lie algebra generators. Applying this to the psu(1,1|2) sector leads to an iterative solution for the planar three-loop dilatation generator in terms of leading order symmetry generators and h, which passes a thorough set of spectral tests. We argue also that this algebraic ansatz may be applicable to the nonplanar theory as well.

Benjamin I. Zwiebel

2008-06-11T23:59:59.000Z

242

Kinetic damping of resistive wall modes in ITER  

SciTech Connect

Full drift kinetic modelling including finite orbit width effects has been used to assess the passive stabilisation of the resistive wall mode (RWM) that can be expected in the ITER advanced scenario. At realistic plasma rotation frequency, the thermal ions have a stabilising effect on the RWM, but the stability limit remains below the target plasma pressure to achieve Q = 5. However, the inclusion of damping arising from the fusion-born alpha particles, the NBI ions, and ICRH fast ions extends the RWM stability limit above the target {beta} for the advanced scenario. The fast ion damping arises primarily from finite orbit width effects and is not due to resonance between the particle frequencies and the instability.

Chapman, I. T.; Liu, Y. Q. [EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon, Oxfordshire OX14 3DB (United Kingdom); Asunta, O. [Department of Applied Physics, Association EURATOM-Tekes, Aalto University, P.O. Box 14100 FI-00076 AALTO (Finland); Graves, J. P. [CRPP, Association EURATOM/Confederation Suisse, EPFL, 1015 Lausanne (Switzerland); Johnson, T. [EURATOM-VR Association, EES, KTH, Stockholm (Sweden); Jucker, M. [GFDL/Princeton University, AOS Program, Princeton, New Jersey 08544 (United States)

2012-05-15T23:59:59.000Z

243

Iterative methods for overlap and twisted mass fermions  

E-Print Network (OSTI)

We present a comparison of a number of iterative solvers of linear systems of equations for obtaining the fermion propagator in lattice QCD. In particular, we consider chirally invariant overlap and chirally improved Wilson (maximally) twisted mass fermions. The comparison of both formulations of lattice QCD is performed at four fixed values of the pion mass between 230MeV and 720MeV. For overlap fermions we address adaptive precision and low mode preconditioning while for twisted mass fermions we discuss even/odd preconditioning. Taking the best available algorithms in each case we find that calculations with the overlap operator are by a factor of 30-120 more expensive than with the twisted mass operator.

T. Chiarappa; K. Jansen; K. -I. Nagai; M. Papinutto; L. Scorzato; A. Shindler; C. Urbach; U. Wenger; I. Wetzorke

2006-09-13T23:59:59.000Z

244

Iterative methods for solving the pressure problem at multiphase filtration  

E-Print Network (OSTI)

Applied problems of oil and gas recovery are studied numerically using the mathematical models of multiphase fluid flows in porous media. The basic model includes the continuity equations and the Darcy laws for each phase, as well as the algebraic expression for the sum of saturations. Primary computational algorithms are implemented for such problems using the pressure equation. In this paper, we highlight the basic properties of the pressure problem and discuss the necessity of their fulfillment at the discrete level. The resulting elliptic problem for the pressure equation is characterized by a non-selfadjoint operator. Possibilities of approximate solving the elliptic problem are considered using the iterative methods. Special attention is given to the numerical algorithms for calculating the pressure on parallel computers.

Vabishchevich, P

2011-01-01T23:59:59.000Z

245

Power Balance in the ITER Plasma and Divertor  

E-Print Network (OSTI)

It is planned to use atomic processes to spread out most of the heating power over the first wall and side walls to reduce the heat loads on the plasma facing components in ITER to ~ 50 MW. Calculations indicate that there will be 100 MW in bremstrahlung radiation from the plasma center, 50 MW of radiation from the plasma edge inside the separatrix and 100 MW of radiation from the scrape-off layer and divertor plasma, leaving 50 MW of power to be deposited on the divertor plates. The radiation losses are enhanced by the injection of impurities such as Neon or Argon at acceptably low levels (~0.1 % Argon, etc.) 1.

unknown authors

1995-01-01T23:59:59.000Z

246

Benchmarking ICRF Full-wave Solvers for ITER  

DOE Green Energy (OSTI)

Abstract Benchmarking of full-wave solvers for ICRF simulations is performed using plasma profiles and equilibria obtained from integrated self-consistent modeling predictions of four ITER plasmas. One is for a high performance baseline (5.3 T, 15 MA) DT H-mode. The others are for half-field, half-current plasmas of interest for the pre-activation phase with bulk plasma ion species being either hydrogen or He4. The predicted profiles are used by six full-wave solver groups to simulate the ICRF electromagnetic fields and heating, and by three of these groups to simulate the current-drive. Approximate agreement is achieved for the predicted heating power for the DT and He4 cases. Factor of two disagreements are found for the cases with second harmonic He3 heating in bulk H cases. Approximate agreement is achieved simulating the ICRF current drive.

R. V. Budny, L. Berry, R. Bilato, P. Bonoli, M. Brambilla, R. J. Dumont, A. Fukuyama, R. Harvey, E. F. Jaeger, K. Indireshkumar, E. Lerche, D. McCune, C. K. Phillips, V. Vdovin, J. Wright, and members of the ITPA-IOS

2011-01-06T23:59:59.000Z

247

Status of ITER neutral beam cell remote handling system  

E-Print Network (OSTI)

The ITER neutral beam cell will contain up to three heating neutral beams and one diagnostic neutral beam, and four upper ports. Though manual maintenance work is envisaged within the cell, when containment is breached, or the radiological protection is removed the maintenance must be conducted remotely. This maintenance constitutes the removal and replacement of line replaceable units, and their transport to and from a cask docked to the cell. A design of the remote handling system has been prepared to concept level which this paper describes including the development of a beam line transporter, beam source remote handling equipment, upper port remote handling equipment and equipment for the maintenance of the neutral shield. This equipment has been developed complete the planned maintenance tasks for the components of the neutral beam cell and to have inherent flexibility to enable as yet unforeseen tasks and recovery operations to be performed.

Sykes, N; Choi, C-H; Crofts, O; Crowe, R; Damiani, C; Delavalle, S; Meredith, L; Mindham, T; Raimbach, J; Tesini, A; Van Uffelen, M

2013-01-01T23:59:59.000Z

248

Occupational Radiation Exposure Analysis of US ITER DCLL TBM  

Science Conference Proceedings (OSTI)

This report documents an Occupational Radiation Exposure (ORE) analysis that was performed for the US International Thermonuclear Experimental Reactor (ITER) Dual Coolant Lead Lithium (DCLL) Test Blanket Module (TBM). This analysis was performed with the QADMOD dose code for anticipated maintenance activities for this TBM concept and its ancillary systems. The QADMOD code was used to model the PbLi cooling loop of this TBM concept by specifying gamma ray source terms that simulated radioactive material within the piping, valves, heat exchanger, permeator, pump, drain tank, and cold trap of this cooling system. Estimates of the maintenance tasks that will have to be performed and the time required to perform these tasks where developed based on either expert opinion or on industrial maintenance experience for similar technologies. This report details the modeling activity and the calculated doses for the maintenance activities envisioned for the US DCLL TBM.

Merrill, Brad J; Cadwallader, Lee C; Dagher, Mohamad

2007-08-01T23:59:59.000Z

249

Safety Analysis of the US Dual Coolant Liquid Lead-Lithium ITER Test Blanket Module  

DOE Green Energy (OSTI)

The US is proposing a prototype of a dual coolant liquid lead-lithium (DCLL) DEMO blanket concept for testing in the International Thermonuclear Experimental Reactor (ITER) as an ITER Test Blanket Module (TBM). Because safety considerations are an integral part of the design process to ensure that this TBM does not adversely impact the safety of ITER, a safety assessment has been conducted for this TBM and its ancillary systems as requested by the ITER project. Four events were selected by the ITER International Team (IT) to address specific reactor safety concerns, such as VV pressurization, confinement building pressure build-up, TBM decay heat removal capability, tritium and activation products release from the TBM system, and hydrogen and heat production from chemical reactions. This paper summarizes the results of this safety assessment conducted with the MELCOR computer code.

Merrill, Brad; Reyes, Susana; Sawan, Mohamed; Wong, Clement

2006-07-01T23:59:59.000Z

250

Development of the bus joint for the ITER Central Solenoid  

SciTech Connect

The terminations of the Central Solenoid (CS) modules are connected to the bus extensions by joints located outside the CS in the gap between the CS and Torodial Field (TF) assemblies. These joints have very strict space limitations. Low resistance is a common requirement for all ITER joints. In addition, the CS bus joints will experience and must be designed to withstand significant variation in the magnetic field of several tenths of a Tesla per second during initiation of plasma. The joint resistance is specified to be less than 4 nOhm. The joints also have to be soldered in the field and designed with the possibility to be installed and dismantled in order to allow cold testing in the cold test facility. We have developed coaxial joints that meet these requirements and have demonstrated the feasibility to fabricate and assemble them in the vertical configuration. We introduced a coupling cylinder with superconducting strands soldered to the surface of the cable that can be installed in the ITER assembly hall and at the Cold Test Facility. This cylinder serves as a transition area between the CS module and the bus extension. We made two racetrack samples and tested four bus joints in our Joint Test Apparatus. Resistance of the bus joints was measured by a decay method and by a microvoltmeter; the value of the current was measured by the Hall probes. This measurement method was verified in the previous tests. The resistance of the joints varied insignificantly from 1.5 to 2 nOhm. One of the challenges associated with a soldered joint is the inability to use corrosive chemicals that are difficult to clean. This paper describes our development work on cable preparation, chrome removal, compaction, soldering, and final assembly and presents the test results.

Martovetsky, Nicolai N [ORNL] [ORNL; Irick, David Kim [ORNL] [ORNL; Kenney, Steven J [ORNL] [ORNL

2013-01-01T23:59:59.000Z

251

Power Plant Cycling Costs  

Science Conference Proceedings (OSTI)

This report provides a detailed review of the most up to date data available on power plant cycling costs. The primary objective of this report is to increase awareness of power plant cycling cost, the use of these costs in renewable integration studies and to stimulate debate between policymakers, system dispatchers, plant personnel and power utilities.

Kumar, N.; Besuner, P.; Lefton, S.; Agan, D.; Hilleman, D.

2012-07-01T23:59:59.000Z

252

Using dual decomposition for solving problems involving data uncertainty |  

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

dual decomposition for solving problems involving data uncertainty dual decomposition for solving problems involving data uncertainty August 14, 2013 Tweet EmailPrint Many applications mdash; energy, routing, scheduling, and production planning, for example mdash; involve problems in which some or all of the data may not be known when decisions under uncertainty must be made. In such cases, approximations with stochastic mixed-integer programming models are often used. Two approaches have been suggested to address such problems: dual decomposition (DD) and branch-and-price (BP). Both approaches divide the problem into two or more subproblems, together with linear constraints that enforce agreement between solutions to the different problems through a series of iterations. Unfortunately, both approaches also suffer from lack

253

ITER's Tokamak Cooling Water System and the Use of ASME Codes to Comply with French Regulations for Nuclear Pressure Equipment  

Science Conference Proceedings (OSTI)

ITER Systems / Proceedings of the Nineteenth Topical Meeting on the Technology of Fusion Energy (TOFE) (Part 1)

Jeanette Berry; Juan Ferrada; Seokho Kim; Warren Curd; Giovanni Dell'Orco; Vladimir Barabash

254

Monotone Domain Decomposition Iterative Method and its Convergence for a Nonlinear Integro-Differential Equation of Volterra Type  

E-Print Network (OSTI)

We apply the monotone domain decomposition iterative method to a nonlinear integro-differential equation of Volterra type and prove its convergence. To do this, by adding a term in both sides of the original equation we make a linear equation to get a monotone domain decomposition iterative scheme and prove the existence, uniqueness and convergence of iterative solutions.

Myong-Gil Rim; Dong-Hyok Kim

2013-04-02T23:59:59.000Z

255

Chinese Statement on Joint Declaration in ITER MM -2 in Moscow XU Guanhua, Minister of Science and Technology  

E-Print Network (OSTI)

Chinese Statement on Joint Declaration in ITER MM - 2 in Moscow XU Guanhua, Minister of Science step towards the Joint Implementation of ITER, after several long-term and tough bilateral discussions Negotiation with other parties so as to prepare for an efficient start of joint implementation of ITER after

256

The Anderson Quin Cycle  

SciTech Connect

The objective of this study was to make a more refined evaluation of the Anderson Quin Cycle based on most recent information on the performance of various elements that will be used in the Anderson Quin Cycle. My original estimate of the work plan for evaluating and optimizing the Anderson Quin Cycle called for 7000 man hours of work. Since this grant was limited to 2150 man hours, we could not expect to achieve all the objectives within the allotted period of work. However, the most relevant program objectives have been completed as reported here. The analysis generally confirms the results originally estimated in my paper on the subject. (Ref. 2) Further optimizations should show even higher efficiencies. The Anderson Quin Cycle (US Patent applied for) basically consists of 5 elements in the power cycle: A refrigeration system to cool and clean the inlet air before it enters the compressor that supplies air for the gas turbine; a gas turbine consisting of a compressor, combustor, and turbine; a steam boiler and steam turbine system using the heat from the exhaust gas out of the gas turbine; a vapor turbine cycle, which utilizes the condensed heat from the exhaust of the steam turbine and the exhaust gas heat leaving the steam boiler to operate a vapor turbine cycle which utilizes another fluid than water, in this case isobutane; and the fifth element consists of a gas cooler and heat pump system, which removes the heat from the exhaust gas to lower its temperature essentially to atmospheric temperature, and at the same time permits treatment of the exhaust gas to remove acid components such as sulfur dioxide and nitrogen oxides. Current industry accepted component characteristics were incorporated in the performance analysis of the overall cycle, ensuring accurate and meaningful operating predictions. The characteristics and performance of each of the elements are described. The thermal efficiency of the optimized calculated Anderson Quin Cycle is 62 percent.

Anderson, J.H.; Bilbow, W.M.

1993-03-18T23:59:59.000Z

257

Cycle isolation monitoring  

SciTech Connect

There are many factors to monitor in power plants, but one that is frequently overlooked is cycle isolation. Often this is an area where plant personnel can find 'low hanging fruit' with great return on investment, especially high energy valve leakage. This type of leakage leads to increased heat rate, potential valve damage and lost generation. The fundamental question to ask is 'What is 100 Btu/kW-hr of heat rate worth to your plant? On a 600 MW coal-fired power plant, a 1% leakage can lead to an 81 Btu/kW-hr impact on the main steam cycle and a 64 Btu/kW-hr impact on the hot reheat cycle. The article gives advice on methods to assist in detecting leaking valves and to monitor cycle isolation. A software product, TP. Plus-CIM was designed to estimate flow rates of potentially leaking valves.

Svensen, L.M. III; Zeigler, J.R.; Todd, F.D.; Alder, G.C. [Santee Copper, Moncks Corner, SC (United States)

2009-07-15T23:59:59.000Z

258

Cycle Chemistry Improvement Program  

Science Conference Proceedings (OSTI)

The purity of water and steam is central to ensuring fossil plant component availability and reliability. This report, which describes formal cycle chemistry improvement programs at nine utilities, will assist utilities in achieving significant operation and maintenance cost reductions.

1997-04-21T23:59:59.000Z

259

Crude Oil Price Cycles  

Gasoline and Diesel Fuel Update (EIA)

The heating oil and diesel fuel price runups in late January were made even more problematic by coming on top of the high side of the latest crude market cycle. Over the past 10...

260

Crude Oil Price Cycles  

U.S. Energy Information Administration (EIA)

The heating oil and diesel price runups in late January were made even more problematic by coming on top of the high side of the latest crude market cycle.

Note: This page contains sample records for the topic "involves iterative cycling" 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 Annual Agricultural Cycle  

E-Print Network (OSTI)

. Sman shad agriculture 1.WAV Length of track 00:44:03 Related tracks (include description/relationship if appropriate) Title of track The Annual Agricultural Cycle Translation of title Description (to be used in archive entry...

Zla ba sgrol ma

2009-11-16T23:59:59.000Z

262

Iterative solutions to large sparse finite element equations  

E-Print Network (OSTI)

Iterative methods are widely used to solve sparse linear systems due to the improvements which can be achieved in reducing the solution time and increasing the size of the problem which can be solved on a given computer compared to traditional direct solvers. The theory behind the convergence rate relationship and storage requirements for the preconditioned conjugate gradient methods using the diagonal scaling, incomplete Cholesky decomposition and SSOR preconditioners is explained in detail in this study. Sparse matrix storage techniques, such as profile, element-by-element, and compact row storage, are described along with the redefined matrix operations for each storage technique which must be used to eliminate the operations on zero elements. A procedure to directly assemble the global stiffness in compact row storage format from element stiffness matrices is introduced. Numerical studies have been performed to compare the storage requirements, the convergence rate, and the solution time for the direct and PCG methods using various storage formats. Effects of different material properties and external loading on the convergence rate and solution time are also analyzed. The test problems for this study are based on the three-dimensional linear elasticity finite element equations. The physical memory of 64 MB of RAM of the IBM RISC/6000 Model 355 workstation was the limiting factor for the size of the sparse linear system that could be solved in this study. The diagonal preconditioned conjugate gradient method with the compact row storage has solved a three-dimensional finite element problem up to a maximum of 50,000 equations on an IBM RISC/6000 Model 355 workstation with 64 MB of RAM. To apply adaptive mesh refinement on certain regions of a coarse mesh, the modeling error over a coarse mesh must be estimated. This thesis will show that the modeling error from an intermediate unconverged coarse mesh solution will closely match the modeling error from the converged solution. This result may lead to quicker solution times for a highly accurate mesh based on adaptive mesh refinement iterative methods.

Wang, Hongbing

1995-01-01T23:59:59.000Z

263

Secular Cycles and Millennial Trends  

E-Print Network (OSTI)

both secular cycles and millennial up- ward trend dynamics.Cycles and Millennial Trends by Andrey Korotayev, ArtemySecular Cycles and Millennial Trends 1 Initially, we want to

Korotayev, Andrey V; Malkov, Artemy S; Khaltourina, Daria A

2006-01-01T23:59:59.000Z

264

Microsoft PowerPoint - Nuclear Fuel Cycle_rev3 (1).pptx [Read...  

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

nuclear fuel cycle options are possible * Argonne is involved in research and technology development related to understanding the science and technology of current and potential...

265

Formation and Sustainment of ITPs in ITER with the Baseline Heating Mix  

SciTech Connect

Plasmas with internal transport barriers (ITBs) are a potential and attractive route to steady-state operation in ITER. These plasmas exhibit radially localized regions of improved con nement with steep pressure gradients in the plasma core, which drive large bootstrap current and generate hollow current pro les and negative shear. This work examines the formation and sustainment of ITBs in ITER with electron cyclotron heating and current drive. It is shown that, with a trade-o of the power delivered to the equatorial and to the upper launcher, the sustainment of steady-state ITBs can be demonstrated in ITER with the baseline heating con guration.

Francesca M. Poli and Charles Kessel

2012-12-03T23:59:59.000Z

266

Sixth-order and Seventh-order Iterative Methods for Solving Nonlinear Equations  

E-Print Network (OSTI)

In this article, we discuss sixth-order and seventh-order iterative methods for nonlinear equations. Derivative-based and derivative-free, both categories are presented for said iterative methods. Especially sixth-order derivative-based and derivative-free iterative families are constructed in such a way that they circumstance a wide class of sixth-order methods which are developed in last many years. Weight functions are introduced to enhance the efficiency and parametric combination gives weight-age flexibility in between weight functions.

Fayyaz Ahmad; Domingo García-Senz

2013-02-13T23:59:59.000Z

267

A comparative study of iterative solutions to linear systems arising in quantum mechanics  

Science Conference Proceedings (OSTI)

This study is mainly focused on iterative solutions with simple diagonal preconditioning to two complex-valued nonsymmetric systems of linear equations arising from a computational chemistry model problem proposed by Sherry Li of NERSC. Numerical experiments show the feasibility of iterative methods to some extent when applied to the problems and reveal the competitiveness of our recently proposed Lanczos biconjugate A-orthonormalization methods to other classic and popular iterative methods. By the way, experiment results also indicate that application specific preconditioners may be mandatory and required for accelerating convergence.

Jing Yanfei, E-mail: yanfeijing@uestc.edu.c [School of Mathematical Sciences/Institute of Computational Science, University of Electronic Science and Technology of China, Chengdu, Sichuan 611731 (China); Huang Tingzhu, E-mail: tzhuang@uestc.edu.c [School of Mathematical Sciences/Institute of Computational Science, University of Electronic Science and Technology of China, Chengdu, Sichuan 611731 (China); Duan Yong, E-mail: duanyong@yahoo.c [School of Mathematical Sciences/Institute of Computational Science, University of Electronic Science and Technology of China, Chengdu, Sichuan 611731 (China); Carpentieri, Bruno, E-mail: b.carpentieri@rug.n [Institute of Mathematics and Computing Science, University of Groningen, Nijenborgh 9, P.O. Box 407, 9700 AK Groningen (Netherlands)

2010-11-01T23:59:59.000Z

268

Fuel Cycle and Isotopes Division  

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

Divisions Fuel Cycle and Isotopes Division Jeffrey Binder, Division Director Jeffrey Binder, Division Director The Fuel Cycle and Isotopes Division (FCID) of the Nuclear Science...

269

DESIGN, ANALYSIS AND TEST CONCEPT FOR PROTOTYPE CRYOLINE OF ITER  

Science Conference Proceedings (OSTI)

The ITER cryo-distribution and cryoline is a part of the in-kind supply for India. The design of the systems is in progress. The topology of torus and neutral beam cryoline is defined as six process pipes along with thermal shield at 80 K and outer vacuum jacket. In order to develop confidence in the concept and to establish the high level of engineering and manufacturing technology, a prototype testing has been proposed. The prototype test will be carried out on 1:1 model in terms of dimension. However, the mass flow rate of the supercritical helium at 4.5 K and gaseous helium at 80 K will be on a 1:10 scale. The prototype cryoline has been designed and analyzed for thermal, structural and hydraulic parameters. The objective of this prototype test is to verify mechanical behavior due to thermal stress and pressure force, thermal and hydraulic performances. The concept of test facility has been realized along with the Piping and Instrumentation (P and I) diagram, instrumentation, controls, data acquisition, 80 K helium generation system along with supply and return valve boxes and interfacing hardware. The design concept, methodology for analysis and results, as well as the test facility have been discussed.

Sarkar, B.; Badgujar, S.; Vaghela, H.; Shah, N.; Bhattacharya, R.; Chakrapani, Ch. [Institute for Plasma Research Bhat, Gandhinagar, Gujarat, 382428 (India)

2008-03-16T23:59:59.000Z

270

Commissioning of the ITER-like ICRF antenna for JET  

Science Conference Proceedings (OSTI)

The new JET ion cyclotron resonance frequency (ICRF) ITER-like antenna (ILA), which was assembled during 2006, was commissioned on the JET RF testbed prior to installation on the JET torus. The 4 resonant double loops (RDL) of the ILA were tested at high power at 42 MHz up to 42 kV for 5 s in 10 min intervals. Low power matching studies using a saltwater load placed in front of the ILA have allowed testing and optimizing proposed matching algorithms on single RDLs, paired RDLs and finally on the full array. The upper limit of the frequency range of the ILA appears to be limited to 47 49 MHz due to the effect on the electrical lengths of the connection between the capacitors and the conjugate T point. Capacitor position scans have allowed obtaining the necessary data to confirm the RF model of the RDL which is necessary for the scattering matrix arc detection. The latter is deemed necessary in order to detect arcs at the low impedance conjugate T of the circuit. The antenna was installed onto JET during August 2007 and commissioning on plasma started May 2008. At present the commissioning of the ILA on JET is ongoing in a series of dedicated experimental campaigns.

Durodie, F. [ERM-KMS, Association EURATOM-Belgian State, Brussels, Belgium; Dumortier, P. [ERM-KMS, Association EURATOM-Belgian State, Brussels, Belgium; Huygen, S. [ERM-KMS, Association EURATOM-Belgian State, Brussels, Belgium; Jachmich, S. [ERM-KMS, Association EURATOM-Belgian State, Brussels, Belgium; Lerche, E. [ERM-KMS, Association EURATOM-Belgian State, Brussels, Belgium; Messiaen, A. [ERM-KMS, Association EURATOM-Belgian State, Brussels, Belgium; Ongena, J. [ERM-KMS, Association EURATOM-Belgian State, Brussels, Belgium; Van Eester, D. [Laboratory for Plasma Physics-ERM/KMS (LPP-ERM/KMS), Brussels, Belgium; Vervier, M. [ERM-KMS, Association EURATOM-Belgian State, Brussels, Belgium; Vrancken, M. [ERM-KMS, Association EURATOM-Belgian State, Brussels, Belgium; Nightingale, M. [EURATOM / UKAEA, Abingdon, UK; Blackman, T. [EURATOM / UKAEA, Abingdon, UK; Edwards, P. [EURATOM / UKAEA, Abingdon, UK; Fanthome, J. [EURATOM / UKAEA, Abingdon, UK; Graham, M. [EURATOM / UKAEA, Abingdon, UK; Jacquet, P. [EURATOM / UKAEA, Abingdon, UK; Kaye, A. [EURATOM / UKAEA, Abingdon, UK; Mayoral, M. -L. [EURATOM / UKAEA, Abingdon, UK; Monakhov, I. [EURATOM / UKAEA, Abingdon, UK; Nicholls, K. [EURATOM / UKAEA, Abingdon, UK; Stork, D. [EURATOM / UKAEA, Abingdon, UK; Walden, A. [EURATOM / UKAEA, Abingdon, UK; Whitehurst, A. [EURATOM / UKAEA, Abingdon, UK; Zastrow, K. -D. [EURATOM / UKAEA, Abingdon, UK; Argouarch, A. [CEA-Cadarache, St. Paul lex Durance, France; Berger-By, G. [CEA-Cadarache, St. Paul lex Durance, France; Loarer, T. [CEA-Cadarache, St. Paul lex Durance, France; Rimini, F. [CEA-Cadarache, St. Paul lex Durance, France; Castano-Giraldo, C. [University of Illinois, Urbana-Champaign; Caughman, John B [ORNL; Goulding, Richard Howell [ORNL; Cocilovo, V. [Association Euratom-ENEA sulla Fusione, Italy; Frigione, D. [Association Euratom-ENEA sulla Fusione, Italy; Sozzi, C. [Association Euratom-ENEA sulla Fusione, Italy; Hobrik, J. [Max-Planck-Institut fu?r Plasmaphysik, EURATOM Association, Garching, Germany; Lamalle, Philippe [ITER Joint Work Site, Cadarache; Nave, M. F. F. [Association EURATOM/IST, Lisbon, Portugal; Tsalas, M. [Association EURATOM-Hellas, Attica, Greece

2009-06-01T23:59:59.000Z

271

The evaporative gas turbine (EGT) cycle  

SciTech Connect

Humidification of the flow through a gas turbine has been proposed in a variety of forms. The STIG plant involves the generation of steam by the gas turbine exhaust in a heat recovery steam generator (HRSG), and its injection into or downstream of the combustion chamber. This increases the mass flow through the turbine and the power output from the plant, with a small increase in efficiency. In the evaporative gas turbine (or EGT) cycle, water is injected in the compressor discharge in a regenerative gas turbine cycle (a so-called CBTX plant--compressor [C], burner [B], turbine [T], heat exchanger [X]); the air is evaporatively cooled before it enters the heat exchanger. While the addition of water increases the turbine mass flow and power output, there is also apparent benefit in reducing the temperature drop in the exhaust stack. In one variation of the basic EGT cycle, water is also added downstream of the evaporative aftercooler, even continuously in the heat exchanger. There are several other variations on the basic cycle (e.g., the cascaded humidified advanced turbine [CHAT]). The present paper analyzes the performance of the EGT cycle. The basic thermodynamics are first discussed, and related to the cycle analysis of a dry regenerative gas turbine plant. Subsequently some detailed calculations of EGT cycles are presented. The main purpose of the work is to seek the optimum pressure ratio in the EGT cycle for given constraints (e.g., fixed maximum to minimum temperature). It is argued that this optimum has a relatively low value.

Horlock, J.H. [Whittle Lab., Cambridge (United Kingdom)

1998-04-01T23:59:59.000Z

272

Power allocation for irregularly modulated MIMO signaling with iterative frequency domain detector  

Science Conference Proceedings (OSTI)

A new power allocation method for irregularly modulated signaling in single carrier point-to-point multiple input multiple output (MIMO) systems with an iterative frequencydomain (FD) soft cancellation (SC) minimum mean squared error (MMSE) equalization ...

Juha Karjalainen; Antti Tölli; Marian Codreanu; Markku Juntti; Tad Matsumoto

2009-11-01T23:59:59.000Z

273

US ITER is a strong contributor in plan to enhance international...  

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

By Lynne Degitz, US ITER March 28, 2013 Tweet Widget Facebook Like Google Plus One PPPL's Russell Feder, left, and David Johnson developed key features for a modular approach to...

274

Gas species, their evolution and segregation through the ITER vacuum systems  

SciTech Connect

This paper takes the ITER fueling requirements and current knowledge of gas balance and exhaust from operating tokamaks to predict all likely gas inputs into the ITER Vacuum systems. Areas where gas dynamics modeling is relevant to the ITER design are highlighted. The design and operation of the ITER vacuum system gives an element of segregation of different gas flows and species. This paper analyses the time dependent gas segregation in the vacuum system resulting from different temperature dependences of cryogenic sorption and condensation processes of different gas species. As a specific example, the optimal transfer of Ar-41 through the vacuum system is studied with respect to its decay and the resulting effects on the design of system components.

Pearce, R.J.H. [ITER Organization, Cadarache, France; Antipenkov, Alexander [ITER Joint Work Site, Cadarache; Bersier, Jean-Louis [ITER Joint Work Site, Cadarache; Boussier, Bastien [ITER Joint Work Site, Cadarache; Baylor, Larry R [ORNL; Gardner, Walter L [ORNL; Meitner, Steven J [ORNL

2012-01-01T23:59:59.000Z

275

PPPL and ITER: Lab teams support the world's largest fusion experiment...  

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

ITER: Lab teams support the world's largest fusion experiment with leading-edge ideas and design By John Greenwald May 7, 2013 Tweet Widget Facebook Like Google Plus One PPPL...

276

An Iterative Regression Model for Estimating Soybean Yields from Environmental Data  

Science Conference Proceedings (OSTI)

A model was developed for using weather data, to estimate the yields of soybeans for varieties adapted to the central United States. The model utilized an iterative regression analysis for relating soybean yields to environmental variables. This ...

Andres C. Ravelo; Wayne L. Decker

1981-11-01T23:59:59.000Z

277

ITER & Fusion Research Reference: MEMO/10/165 Date: 05/05/2010  

E-Print Network (OSTI)

230 million. Already in April 2010 a very important contract, the Architect Engineering contract for ITER buildings was signed between F4E and the ENGAGE consortium of European industries. The Architect

278

June 28, 2005 U.S.Statements on International Fusion Reactor (ITER)  

E-Print Network (OSTI)

to produce clean, safe, renewable, and commercially-available fusion energy by the middle of this century to the ITER talks. China, the European Union, Japan, the Russian Federation, and South Korea also

279

On the Green's function and iterative solutions of Loop Quantum Cosmology  

E-Print Network (OSTI)

Here we shall find the green's function of the difference equation of loop quantum cosmology. To illustrate how to use it, we shall obtain an iterative solution for closed model and evaluate its corresponding Bohmian trajectory.

Fatimah Shojai; Ali Shojai

2006-07-09T23:59:59.000Z

280

Quantum Fisher Information: Variational principle and simple iterative algorithm for its efficient computation  

E-Print Network (OSTI)

We derive a new variational principle for the quantum Fisher information leading to a simple iterative alternating algorithm, the convergence of which is proved. The case of a fixed measurement, i.e. the classical Fisher information, is also discussed.

Katarzyna Macieszczak

2013-12-04T23:59:59.000Z

Note: This page contains sample records for the topic "involves iterative cycling" 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

U.S. PARTICIPATION IN THE ITER TEST BLANKET MODULE (TBM) PROGRAM  

E-Print Network (OSTI)

for fusion accumulated over 40 years of CANDU reactors operation will peak at 27 kg in the year 2027 and of about $200 million dollars per kg. The CANDU tritium supply will be available for use in ITER in its

Abdou, Mohamed

282

Accelerated Iterative Method for Solving Steady Problems of Linearized Atmospheric Models  

Science Conference Proceedings (OSTI)

A new approach, referred to as the accelerated iterative method (AIM), is developed for obtaining steady atmospheric responses with a zonally varying basic state. The linear dynamical operator is divided into two parts, one associated with the ...

Masahiro Watanabe; Fei-fei Jin; Lin Pan

2006-12-01T23:59:59.000Z

283

Electromagnetic analysis of forces and torques on the ITER shield modules due to plasma disruption.  

SciTech Connect

An electromagnetic analysis is performed on the ITER shield modules under different plasma disruption scenarios using the OPERA-3d software. The modeling procedure is explained, electromagnetic torques are presented, and results of the modeling are discussed.

Kotulski, Joseph Daniel; Coats, Rebecca Sue; Pasik, Michael Francis; Ulrickson, Michael Andrew

2009-06-01T23:59:59.000Z

284

International nuclear fuel cycle fact book  

Science Conference Proceedings (OSTI)

As the US Department of Energy (DOE) and DOE contractors have become increasingly involved with other nations in nuclear fuel cycle and waste management cooperative activities, a need has developed for a ready source or information concerning foreign fuel cycle programs, facilities, and personnel. This Fact Book was compiled to meet that need. The information contained has been obtained from nuclear trade journals and newsletters; reports of foreign visits and visitors; CEC, IAEA, and OECD/NEA activities reports; proceedings of conferences and workshops; and so forth. Sources do not agree completely with each other, and the data listed herein does not reflect any one single source but frequently is consolidation/combination of information. Lack of space as well as the intent and purpose of the Fact Book limit the given information to that pertaining to the Nuclear Fuel Cycle and to data considered of primary interest or most helpful to the majority of users.

Leigh, I.W.

1988-01-01T23:59:59.000Z

285

Helium process cycle  

DOE Patents (OSTI)

A unique process cycle and apparatus design separates the consumer (cryogenic) load return flow from most of the recycle return flow of a refrigerator and/or liquefier process cycle. The refrigerator and/or liquefier process recycle return flow is recompressed by a multi-stage compressor set and the consumer load return flow is recompressed by an independent consumer load compressor set that maintains a desirable constant suction pressure using a consumer load bypass control valve and the consumer load return pressure control valve that controls the consumer load compressor's suction pressure. The discharge pressure of this consumer load compressor is thereby allowed to float at the intermediate pressure in between the first and second stage recycle compressor sets. Utilizing the unique gas management valve regulation, the unique process cycle and apparatus design in which the consumer load return flow is separate from the recycle return flow, the pressure ratios of each recycle compressor stage and all main pressures associated with the recycle return flow are allowed to vary naturally, thus providing a naturally regulated and balanced floating pressure process cycle that maintains optimal efficiency at design and off-design process cycle capacity and conditions automatically.

Ganni, Venkatarao (Yorktown, VA)

2007-10-09T23:59:59.000Z

286

Helium process cycle  

SciTech Connect

A unique process cycle and apparatus design separates the consumer (cryogenic) load return flow from most of the recycle return flow of a refrigerator and/or liquefier process cycle. The refrigerator and/or liquefier process recycle return flow is recompressed by a multi-stage compressor set and the consumer load return flow is recompressed by an independent consumer load compressor set that maintains a desirable constant suction pressure using a consumer load bypass control valve and the consumer load return pressure control valve that controls the consumer load compressor's suction pressure. The discharge pressure of this consumer load compressor is thereby allowed to float at the intermediate pressure in between the first and second stage recycle compressor sets. Utilizing the unique gas management valve regulation, the unique process cycle and apparatus design in which the consumer load return flow is separate from the recycle return flow, the pressure ratios of each recycle compressor stage and all main pressures associated with the recycle return flow are allowed to vary naturally, thus providing a naturally regulated and balanced floating pressure process cycle that maintains optimal efficiency at design and off-design process cycle capacity and conditions automatically.

Ganni, Venkatarao (Yorktown, VA)

2007-10-09T23:59:59.000Z

287

Helium process cycle  

DOE Patents (OSTI)

A unique process cycle and apparatus design separates the consumer (cryogenic) load return flow from most of the recycle return flow of a refrigerator and/or liquefier process cycle. The refrigerator and/or liquefier process recycle return flow is recompressed by a multi-stage compressor set and the consumer load return flow is recompressed by an independent consumer load compressor set that maintains a desirable constant suction pressure using a consumer load bypass control valve and the consumer load return pressure control valve that controls the consumer load compressor's suction pressure. The discharge pressure of this consumer load compressor is thereby allowed to float at the intermediate pressure in between the first and second stage recycle compressor sets. Utilizing the unique gas management valve regulation, the unique process cycle and apparatus design in which the consumer load return flow is separate from the recycle return flow, the pressure ratios of each recycle compressor stage and all main pressures associated with the recycle return flow are allowed to vary naturally, thus providing a naturally regulated and balanced floating pressure process cycle that maintains optimal efficiency at design and off-design process cycle capacity and conditions automatically.

Ganni, Venkatarao (Yorktown, VA)

2008-08-12T23:59:59.000Z

288

Qualification of the US Made Conductors for ITER TF Magnet System  

Science Conference Proceedings (OSTI)

The US Domestic Agency (USDA) is one of the six suppliers of the TF conductor for ITER. In order to qualify conductors according to ITER requirements we prepared several lengths of the CICC and short samples for testing in the SULTAN facility in CRPP, Switzerland. We also fully characterized the strands that were used in these SULTAN samples. Fabrication experience and test results are presented and discussed.

Martovetsky, Nicolai N [ORNL; Hatfield, Daniel R [ORNL; Miller, John R [ORNL; Bruzzone, P. [CRPP, Switzerland; Stepanov, B. [CRPP, Switzerland; Seber, B. [University of Geneva

2010-01-01T23:59:59.000Z

289

On Iterative Solution for Linear Complementarity Problem with an $H_{+}$-Matrix  

Science Conference Proceedings (OSTI)

The numerous applications of the linear complementarity problem (LCP) in, e.g., the solution of linear and convex quadratic programming, free boundary value problems of fluid mechanics, and moving boundary value problems of economics make ... Keywords: $H_+$-matrices, $M$-matrices, $P$-matrices, (block) modulus algorithm, LCP, iterative schemes, modified AOR method, modulus-based matrix splitting iteration methods, real positive definite matrices, scaled extrapolation, strictly diagonally dominant matrices

A. Hadjidimos; M. Lapidakis; M. Tzoumas

2012-01-01T23:59:59.000Z

290

Power Plant Cycling Costs  

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

Power Plant Cycling Costs Power Plant Cycling Costs April 2012 N. Kumar, P. Besuner, S. Lefton, D. Agan, and D. Hilleman Intertek APTECH Sunnyvale, California NREL Technical Monitor: Debra Lew Subcontract Report NREL/SR-5500-55433 July 2012 NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency & Renewable Energy, operated by the Alliance for Sustainable Energy, LLC. National Renewable Energy Laboratory 15013 Denver West Parkway Golden, Colorado 80401 303-275-3000 * www.nrel.gov Contract No. DE-AC36-08GO28308 Power Plant Cycling Costs April 2012 N. Kumar, P. Besuner, S. Lefton, D. Agan, and D. Hilleman Intertek APTECH Sunnyvale, California NREL Technical Monitor: Debra Lew Prepared under Subcontract No. NFT-1-11325-01

291

Superfluid thermodynamic cycle refrigerator  

DOE Patents (OSTI)

This invention is comprised of a cryogenic refrigerator which cools a heat source by cyclically concentrating and diluting the amount of [sup 3]He in a single phase [sup 3]He/[sup 4]He solution. The [sup 3]He in superfluid [sup 4]He acts in a manner of an ideal gas in a vacuum. Thus, refrigeration is obtained using any conventional thermal cycle, but preferably a Stirling or Carnot cycle. A single phase solution of liquid [sup 3]He at an initial concentration in superfluid [sup 4]He is contained in a first variable volume connected to a second variable volume through a superleak device that enables free passage of [sup 4]He while restricting passage of [sup 3]He. The [sup 3]He is compressed (concentrated) and expanded (diluted) in a phased manner to carry out the selected thermal cycle to remove heat from the heat load for cooling below 1 K.

Swift, G.W.; Kotsubo, V.Y.

1991-04-02T23:59:59.000Z

292

Superfluid thermodynamic cycle refrigerator  

DOE Patents (OSTI)

A cryogenic refrigerator cools a heat source by cyclically concentrating and diluting the amount of [sup 3]He in a single phase [sup 3]He-[sup 4]He solution. The [sup 3]He in superfluid [sup 4]He acts in a manner of an ideal gas in a vacuum. Thus, refrigeration is obtained using any conventional thermal cycle, but preferably a Stirling or Carnot cycle. A single phase solution of liquid [sup 3]He at an initial concentration in superfluid [sup 4]He is contained in a first variable volume connected to a second variable volume through a superleak device that enables free passage of [sup 4]He while restricting passage of [sup 3]He. The [sup 3]He is compressed (concentrated) and expanded (diluted) in a phased manner to carry out the selected thermal cycle to remove heat from the heat load for cooling below 1 K. 12 figs.

Swift, G.W.; Kotsubo, V.Y.

1992-12-22T23:59:59.000Z

293

Superfluid thermodynamic cycle refrigerator  

DOE Patents (OSTI)

This invention is comprised of a cryogenic refrigerator which cools a heat source by cyclically concentrating and diluting the amount of {sup 3}He in a single phase {sup 3}He/{sup 4}He solution. The {sup 3}He in superfluid {sup 4}He acts in a manner of an ideal gas in a vacuum. Thus, refrigeration is obtained using any conventional thermal cycle, but preferably a Stirling or Carnot cycle. A single phase solution of liquid {sup 3}He at an initial concentration in superfluid {sup 4}He is contained in a first variable volume connected to a second variable volume through a superleak device that enables free passage of {sup 4}He while restricting passage of {sup 3}He. The {sup 3}He is compressed (concentrated) and expanded (diluted) in a phased manner to carry out the selected thermal cycle to remove heat from the heat load for cooling below 1 K.

Swift, G.W.; Kotsubo, V.Y.

1991-04-02T23:59:59.000Z

294

Superfluid thermodynamic cycle refrigerator  

DOE Patents (OSTI)

A cryogenic refrigerator cools a heat source by cyclically concentrating and diluting the amount of .sup.3 He in a single phase .sup.3 He-.sup.4 He solution. The .sup.3 He in superfluid .sup.4 He acts in a manner of an ideal gas in a vacuum. Thus, refrigeration is obtained using any conventional thermal cycle, but preferably a Stirling or Carnot cycle. A single phase solution of liquid .sup.3 He at an initial concentration in superfluid .sup.4 He is contained in a first variable volume connected to a second variable volume through a superleak device that enables free passage of .sup.4 He while restricting passage of .sup.3 He. The .sup.3 He is compressed (concentrated) and expanded (diluted) in a phased manner to carry out the selected thermal cycle to remove heat from the heat load for cooling below 1 K.

Swift, Gregory W. (Santa Fe, NM); Kotsubo, Vincent Y. (La Canada, CA)

1992-01-01T23:59:59.000Z

295

Regional business cycles in Italy  

Science Conference Proceedings (OSTI)

There is clear evidence for differences in the structure of the Italian regional business cycle in the period 1951-2004: the relationship with the national business cycle is closer in the North than in the South. The interaction between regional cycles ... Keywords: Regional business cycles, Spectral analysis, Stylized facts

Camilla Mastromarco; Ulrich Woitek

2007-10-01T23:59:59.000Z

296

Combined Cycle Cogeneration at NALCO Chemical  

E-Print Network (OSTI)

The Nalco Chemical Company, while expanding their corporate headquarters, elected to investigate the potential for cogeneration. The headquarters complex has a central physical plant for heating and chilling. The authors describe the analysis approach for determining the most economical system design. Generation capacity ranging from 2.7 MW up to 7.0 MW in both simple cycle cogeneration and combined cycle cogeneration was analyzed. Both single pressure and dual pressure waste heat boilers were included in the evaluation. In addition, absorption chilling and electrical centrifugal chilling capacity expansion were integrated into the model. The gas turbine selection procedure is outlined. Bid evaluation procedure involved a life cycle cost comparison wherein the bid specification responses for each model turbine were incorporated into the life cycle facility program. The recommendation for the facility is a 4.0MW combined cycle cogeneration system. This system is scheduled for startup in October of 1985. Most major equipment has been purchased and the building to house the system is nearing completion. A discussion of the purchase and scheduling integration will be included.

Thunem, C. B.; Jacobs, K. W.; Hanzel, W.

1985-05-01T23:59:59.000Z

297

Experiment and Modeling of ITER Demonstration Discharges in the DIII-D Tokamak  

Science Conference Proceedings (OSTI)

DIII-D is providing experimental evaluation of 4 leading ITER operational scenarios: the baseline scenario in ELMing H-mode, the advanced inductive scenario, the hybrid scenario, and the steady state scenario. The anticipated ITER shape, aspect ratio and value of I/{alpha}B were reproduced, with the size reduced by a factor of 3.7, while matching key performance targets for {beta}{sub N} and H{sub 98}. Since 2008, substantial experimental progress was made to improve the match to other expected ITER parameters for the baseline scenario. A lower density baseline discharge was developed with improved stationarity and density control to match the expected ITER edge pedestal collisionality ({nu}*{sub e} {approx} 0.1). Target values for {beta}{sub N} and H{sub 98} were maintained at lower collisionality (lower density) operation without loss in fusion performance but with significant change in ELM characteristics. The effects of lower plasma rotation were investigated by adding counter-neutral beam power, resulting in only a modest reduction in confinement. Robust preemptive stabilization of 2/1 NTMs was demonstrated for the first time using ECCD under ITER-like conditions. Data from these experiments were used extensively to test and develop theory and modeling for realistic ITER projection and for further development of its optimum scenarios in DIII-D. Theory-based modeling of core transport (TGLF) with an edge pedestal boundary condition provided by the EPED1 model reproduces T{sub e} and T{sub i} profiles reasonably well for the 4 ITER scenarios developed in DIII-D. Modeling of the baseline scenario for low and high rotation discharges indicates that a modest performance increase of {approx} 15% is needed to compensate for the expected lower rotation of ITER. Modeling of the steady-state scenario reproduces a strong dependence of confinement, stability, and noninductive fraction (f{sub NI}) on q{sub 95}, as found in the experimental I{sub p} scan, indicating that optimization of the q profile is critical to simultaneously achieving the f{sub NI} = 1 and Q = 5 goals. Extended integrated modeling is being developed to improve capability for ITER projection by including the experimental observations of density peaking, ELM characteristics, NTM suppression and coupled core-edge-SOL transport.

Park, Jin Myung [ORNL; Doyle, E. J. [University of California, Los Angeles; Ferron, J.R. [General Atomics, San Diego; Holcomb, C T [Lawrence Livermore National Laboratory (LLNL); Jackson, G. L. [General Atomics; Lao, L. L. [General Atomics; Luce, T.C. [General Atomics, San Diego; Owen, Larry W [ORNL; Murakami, Masanori [ORNL; Osborne, T. H. [General Atomics; Politzer, P. A. [General Atomics, San Diego; Prater, R. [General Atomics; Snyder, P. B. [General Atomics

2011-01-01T23:59:59.000Z

298

BNL | Carbon Cycle Science  

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

The Carbon Cycle Science & Technology Group aims to increase understanding The Carbon Cycle Science & Technology Group aims to increase understanding of the impacts of global change on managed and unmanaged ecosystems and improve knowledge of possible global change mitigation approaches. The group has three main focus areas. FACE Climate Change Experimental Facility Design and Management The CCS&T group is an internationally recognized leader in the development of Free Air CO2 Enrichment (FACE) research facilities. We are interested in the design and management of manipulative experiments that examine the effects of carbon dioxide, ozone, other atmospheric pollutants, temperature and precipitation on natural and managed ecosystems. FACE Plant Physiology and High Throughput Biochemical Phenotyping At FACE facilities we have studied the mechanisms that underlie the

299

Fuel Cycle Subcommittee  

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

Report to NEAC Report to NEAC Fuel Cycle Subcommittee Meeting of April 23, 2013 Washington D.C. June 13, 2013 Burton Richter (Chair), Margaret Chu, Darleane Hoffman, Raymond Juzaitis, Sekazi K Mtingwa, Ronald P Omberg, Joy L Rempe, Dominique Warin 2 I Introduction and Summary The Fuel Cycle Subcommittee of NEAC met in Washington on April 23, 2013. The meeting focused on issues relating to the NE advanced reactor program (sections II, III, and IV), and on storage and transportation issues (section V) related to a possible interim storage program that is the first step in moving toward a new permanent repository as recommended by the Blue Ribbon Commission (BRC) and discussed in the recent response by DOE to Congress on the BRC report 1 . The agenda is given in

300

THE CRYOPLANT FOR THE ITER NEUTRAL BEAM TEST FACILITY TO BE BUILT AT RFX IN PADOVA, ITALY  

Science Conference Proceedings (OSTI)

The Neutral Beam Test Facility (NBTF), planned to be constructed in Padua (Italy), will constitute the prototype of the two Neutral Beam Injectors (NBI), which will be installed in the ITER plant (Cadarache-France). The NBTF is composed of a 1 MV accelerator that can produce a 40 A deuteron pulsed neutral beam particles. The necessary vacuum needed in the accelerator is achieved by two large cryopumps, designed by FZK-Karlsruhe, with radiation shields cooled between 65 K and 90 K and with cryopanels cooled by 4 bar supercritical helium (ScHe) between 4.5 K and 6.5 K. A new cryoplant facility will be installed with two large helium refrigerators: a Shield Refrigerator (SR), whose cooling capacity is up to 30 kW between 65 K and 90 K, and a helium Main Refrigerator (MR), whose equivalent cooling capacity is up to 800 W at 4.5 K. The cooling of the cryopanels is obtained with two (ScHe) 30 g/s pumps (one redundant), working in a closed cycle around 4 bar producing a pressure head of 100 mbar. Two heat exchangers are immersed in a buffer dewar connected to the MR. The MR and SR different operation modes are described in the paper, as well as the new cryoplant installation.

Pengo, R. [INFN-LNL, Viale dell'Universita 2, I-35020 Legnaro, Padova (Italy); Fellin, F. [Consorzio RFX, 35127 Camin, Padova (Italy); Sonato, P. [Consorzio RFX, 35127 Camin, Padova (Italy); Dipartimento d'Ingegneria Elettrica dell'Universita' di Padova, 35100 Padova (Italy)

2010-04-09T23:59:59.000Z

Note: This page contains sample records for the topic "involves iterative cycling" from the National Library of EnergyBeta (NLEBeta).
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301

Stirling cycle engine  

DOE Patents (OSTI)

In a Stirling cycle engine having a plurality of working gas charges separated by pistons reciprocating in cylinders, the total gas content is minimized and the mean pressure equalization among the serial cylinders is improved by using two piston rings axially spaced at least as much as the piston stroke and by providing a duct in the cylinder wall opening in the space between the two piston rings and leading to a source of minimum or maximum working gas pressure.

Lundholm, Gunnar (Lund, SE)

1983-01-01T23:59:59.000Z

302

USCEA fuel cycle '93  

SciTech Connect

The US Council for Energy Awareness sponsored the Fuel Cycle '93 conference in Dallas, Texas, on March 21-24, 1993. Over 250 participants attended, numerous papers were presented, and several panel discussions were held. The focus of most industry participants remains the formation of USEC and the pending US-Russian HEU agreement. Following are brief summaries of two key papers and the Fuel Market Issues panel discussion.

Not Available

1993-04-01T23:59:59.000Z

303

Status of the 1 MeV Accelerator Design for ITER NBI  

SciTech Connect

The beam source of neutral beam heating/current drive system for ITER is needed to accelerate the negative ion beam of 40A with D{sup -} at 1 MeV for 3600 sec. In order to realize the beam source, design and R and D works are being developed in many institutions under the coordination of ITER organization. The development of the key issues of the ion source including source plasma uniformity, suppression of co-extracted electron in D beam operation and also after the long beam duration time of over a few 100 sec, is progressed mainly in IPP with the facilities of BATMAN, MANITU and RADI. In the near future, ELISE, that will be tested the half size of the ITER ion source, will start the operation in 2011, and then SPIDER, which demonstrates negative ion production and extraction with the same size and same structure as the ITER ion source, will start the operation in 2014 as part of the NBTF. The development of the accelerator is progressed mainly in JAEA with the MeV test facility, and also the computer simulation of beam optics also developed in JAEA, CEA and RFX. The full ITER heating and current drive beam performance will be demonstrated in MITICA, which will start operation in 2016 as part of the NBTF.

Kuriyama, M.; Boilson, D.; Hemsworth, R.; Svensson, L.; Graceffa, J.; Schunke, B.; Decamps, H.; Tanaka, M. [ITER Organization, 13067 Saint-Paul-lez-Durance Cede (France); Bonicelli, T.; Masiello, A. [Fusion for Energy, C/Josep Pla 2, 08019 Barcelona (Spain); Bigi, M.; Chitarin, G.; Luchetta, A.; Marcuzzi, D.; Pasqualotto, R.; Pomaro, N.; Serianni, G.; Sonato, P.; Toigo, V.; Zaccaria, P. [Consorzio RFX. Corso Stati Uniti 4 35127 Padova (Italy)

2011-09-26T23:59:59.000Z

304

Tobacco Industry Involvement in Colorado  

E-Print Network (OSTI)

Accessed May 25, 2004) Industry Summary. 1992 (est. ).11 May 2004) Tobacco Industry Involvement in Colorado Pageor (800) LUNG-USA. Tobacco Industry Involvement in Colorado

Landman, BA, Anne; Bialick, Peter

2004-01-01T23:59:59.000Z

305

Dynamic Mercury Cycling Model Upgrade  

Science Conference Proceedings (OSTI)

This technical update describes the status of activities to upgrade the Dynamic Mercury Cycling Model (D-MCM), an EPRI simulation model that predicts mercury cycling and bioaccumulation in lakes.

2008-12-17T23:59:59.000Z

306

Gas Turbine Technology, Part A: Overview, Cycles, and Thermodynamic Performance  

E-Print Network (OSTI)

The growth of cogeneration technology has accelerated in recent years, and it is estimated that fifty percent of the cogeneration market will involve gas turbines. To several energy engineers, gas turbine engines present a new and somewhat perplexing prime mover. This paper (Parts A & B) intends to treat the area of gas turbine technology to provide a broad overview and understanding of this subject. This paper (Part A) covers the basics of gas turbine cycles, thermodynamics and performance considerations that are important in cogeneration. Simple, regenerative and combined cycles will be discussed, along with important performance losses (inlet and exit losses and part load operation). Waste heat recovery, as it relates to gas turbine performance, will also be discussed. This paper will provide the basic equations enabling quick computations to be made. Topics such as typical efficiencies, evaporative cooling costs, emissions, etc. will be discussed. A brief discussion of advanced cycles such as the dual fluid cycle and close cycles is also made.

Meher-Homji, C. B.; Focke, A. B.

1985-05-01T23:59:59.000Z

307

"Progress in U.S. ITER Magnet Systems", Wayne Reiersen, Princeton  

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

November 28, 2012, 4:15pm November 28, 2012, 4:15pm MBG Auditorium "Progress in U.S. ITER Magnet Systems", Wayne Reiersen, Princeton University Mr. Wayne Reiersen Princeton University U.S. ITER is responsible for providing the ITER Central Solenoid (CS), nine lengths of Toroidal Field (TF) Coil conductor, and Insert Coils for assessing CS and TF conductor performance. The status of the ongoing design and fabrication efforts will be reviewed. The interesting hurdles that had to be negotiated, the lingering problems, and the lessons learned will be discussed. (At the presenter's request, no video or presentation materials are available for this lecture.) Contact Information Coordinator(s): Carol Ann Austin caustin@pppl.gov Host(s): Phil Heitzenroeder pheitzen@pppl.gov PPPL Entrance Procedures

308

RAMI Analyses of Heating Neutral Beam and Diagnostic Neutral Beam Systems for ITER  

SciTech Connect

A RAMI (Reliability, Availability, Maintainability, Inspectability) analysis has been performed for the heating (and current drive) neutral beam (HNB) and diagnostic neutral beam (DNB) systems of the ITER device. The objective of these analyses is to implement RAMI engineering requirements for design and testing to prepare a reliability-centred plan for commissioning, operation, and maintenance of the system in the framework of technical risk control to support the overall ITER Project. These RAMI requirements will correspond to the RAMI targets for the ITER project and the compensating provisions to reach them as deduced from the necessary actions to decrease the risk level of the function failure modes. The RAMI analyses results have to match with the procurement plan of the systems.

Chang, D. H. [Korea Atomic Energy Research Institute(KAERI), Daejeon 305-353 (Korea, Republic of); Lee, S. [ITER-Korea Domestic Agency, National Fusion Research Institute(NFRI), Daejeon 305-333 (Korea, Republic of); Hemsworth, R.; Houtte, D. van; Okayama, K.; Sagot, F.; Schunke, B.; Svensson, L. [ITER Organization, 13067 St. Paul-lez-Durance Cedex (France)

2011-09-26T23:59:59.000Z

309

Iterative receivers for OFDM systems with dispersive fading and frequency offset  

E-Print Network (OSTI)

The presence of dispersive fading and inter-carrier interference (ICI) constitute the major impediment to reliable communications in orthogonal frequency-division multiplexing (OFDM) systems. Recently iterative (``Turbo'') processing techniques, which have been successfully applied to many detection/decoding problems, have received considerable attention. In this thesis, we first aim on the design of iterative receiver for single antenna OFDM system with frequency offset and dispersive fading. Further work is then extended to space-time block coded (STBC) OFDM system. At last, the technique is applied to STBC-OFDM system through a newly built channel model, which is based on a physical description of the propagation environment. The performance of such systems are verified by computer simulations. The simulation results show that the iterative techniques work well in OFDM systems.

Liu, Hui

2005-05-01T23:59:59.000Z

310

Tungsten spectroscopy relevant to the diagnostics development of ITER divertor plasmas  

DOE Green Energy (OSTI)

The ITER tokamak will have tungsten divertor tiles and, consequently, the divertor plasmas are expected to contain tungsten ions. The spectral emission from these ions can serve to diagnose the divertor for plasma parameters such as tungsten concentrations, densities, ion and electron temperatures, and flow velocities. The ITER divertor plasmas will likely have densities around 10{sup 14-15} cm{sup -3} and temperatures below 150 eV. These conditions are similar to the plasmas at the Sustained Spheromak Physics Experiment (SSPX) in Livermore. To simulate ITER divertor plasmas, a tungsten impurity was introduced into the SSPX spheromak by prefilling it with tungsten hexacarbonyl prior to the usual hydrogen gas injection and initiation of the plasma discharge. The possibility of using the emission from low charge state tungsten ions to diagnose tokamak divertor plasmas has been investigated using a high-resolution extreme ultraviolet spectrometer.

Clementson, J; Beiersdorfer, P; Magee, E W; McLean, H S; Wood, R D

2009-12-01T23:59:59.000Z

311

Implementation of the Iterative Proportion Fitting Algorithm for Geostatistical Facies Modeling  

SciTech Connect

In geostatistics, most stochastic algorithm for simulation of categorical variables such as facies or rock types require a conditional probability distribution. The multivariate probability distribution of all the grouped locations including the unsampled location permits calculation of the conditional probability directly based on its definition. In this article, the iterative proportion fitting (IPF) algorithm is implemented to infer this multivariate probability. Using the IPF algorithm, the multivariate probability is obtained by iterative modification to an initial estimated multivariate probability using lower order bivariate probabilities as constraints. The imposed bivariate marginal probabilities are inferred from profiles along drill holes or wells. In the IPF process, a sparse matrix is used to calculate the marginal probabilities from the multivariate probability, which makes the iterative fitting more tractable and practical. This algorithm can be extended to higher order marginal probability constraints as used in multiple point statistics. The theoretical framework is developed and illustrated with estimation and simulation example.

Li Yupeng, E-mail: yupeng@ualberta.ca; Deutsch, Clayton V. [University of Alberta (Canada)

2012-06-15T23:59:59.000Z

312

Overview of recent supercritical binary geothermal cycle experiments from the Heat Cycle Research Program  

DOE Green Energy (OSTI)

The Heat Cycle Research Program, which is being conducted for the Department of Energy, has as its objective the development of the technology for effecting improved utilization of moderate temperature geothermal resources. Testing at the Heat Cycle Research Facility located at the DOE Geothermal Test Facility East Mesa, California involves supercritical vaporization and counterflow in-tube condensing in an organic Rankine cycle. Results of the experiments are given for both pure and mixed-hydrocarbon working fluids. The heater and condenser behavior predicted by the Heat Transfer Research, Inc. computer codes used for correlation of the data was in excellent agreement with experimental results. A special series of tests, conducted with propane and up to approximately 40% isopentane concentration, indicated that a close approach to ''integral'' condensation was occurring in the vertically-oriented condenser. Preliminary results of tests in which the turbine expansion ''passed through the two-phase region'' did not indicate efficiency degradation assignable to these metastable expansion processes.

Demuth, O.J.; Bliem, C.J.; Mines, G.L.; Swank, W.D.

1986-01-01T23:59:59.000Z

313

Query estimation and order-optimized iteration in very large federations  

SciTech Connect

Objectivity federated databases may contain many terabytes of data and span thousands of files. In such an environment, it is often easy for a user to pose a query that may return an iterator over millions of objects, requiring opening thousands of databases. This presentation describes several technologies developed for such settings: (1) a query estimator, which tells the user how many objects satisfy the query, and how many databases will be touched, prior to opening all of those files; (2) an order-optimized iterator, which behaves like an ordinary iterator except that elements are returned in an order optimized for efficient access, presorted by the database (and container) in which they reside; (3) a parallel implementation of the order-optimized iterator, allowing any number of processes in a parallel or distributed system to iterate over disjoint subcollections of terms satisfying the query, partitioned by the database or container in which the items reside. These technologies have been developed for scientific experiments that will require handling thousands of terabytes of data annually, but they are intended to be applicable in other massive data settings as well. In such environments, significant amounts of data will reside on tertiary storage, accessible via Objectivity`s recently-announced HPSS (High Performance Storage System) interface. When deployed in large-scale physics settings later in 1998, the query estimator will further inform the user of the number of tape mounts required to satisfy the query, and provide rough time estimates for data delivery. The order-optimized iterator will be connected to a cache manager that will prefetch from tape to disk the files needed by the query (known from the query estimation step), and will decide which items to deliver to the user next according to the order in which data become available in the disk cache.

Malon, D.M.; HENP Grand Challenge Collaboration

1998-05-04T23:59:59.000Z

314

Electromagnetic Analysis of ITER Diagnostic Equatorial Port Plugs During Plasma Disruptions  

Science Conference Proceedings (OSTI)

ITER diagnostic port plugs perform many functionsincluding structural support of diagnostic systems under high electromagnetic loads while allowing for diagnostic access to the plasma. The design of diagnostic equatorial port plugs (EPP) are largely driven by electromagnetic loads and associate responses of EPP structure during plasma disruptions and VDEs. This paper summarizes results of transient electromagnetic analysis using Opera 3d in support of the design activities for ITER diagnostic EPP. A complete distribution of disruption loads on the Diagnostic First Walls (DFWs), Diagnostic Shield Modules (DSMs) and the EPP structure, as well as impact on the system design integration due to electrical contact among various EPP structural components are discussed.

Y. Zhai, R. Feder, A. Brooks, M. Ulrickson, C.S. Pitcher and G.D. Loesser

2012-08-27T23:59:59.000Z

315

Progress in design and integration of the ITER Electron Cyclotron H&CD system  

Science Conference Proceedings (OSTI)

The Electron Cyclotron system for ITER is an in-kind procurement shared between five parties and the total installed power will be 24 MW, corresponding to a nominal injected power of 20 MW to the plasma, with a possible upgrade up to 48 MW (corresponding to 40 MW injected). Some critical issues have been raised and changes are proposed to simplify these procurements and to facilitate the integration into ITER. The progress in the design and the integration of the EC system into the whole project is presented in this paper, as well as some issues still under studies and some recommendations made by external expert committees.

Darbos, Caroline [ITER Joint Work Site, Cadarache; Henderson, Mark [ITER Joint Work Site, Cadarache; Kobayashi, N. [ITER Joint Work Site, Cadarache; Albajar, F. [Fusion for Energy (F4E), Barcelona, Spain; Bonicelli, T. [Fusion for Energy (F4E), Barcelona, Spain; Saibene, G. [Fusion for Energy (F4E), Barcelona, Spain; Bigelow, Timothy S [ORNL; Rasmussen, David A [ORNL; Chavan, R. [EPFL, Lausanne, Switzerland; Fasel, D. [EPFL, Lausanne, Switzerland; Hogge, J. P. [EPFL, Lausanne, Switzerland; Denisov, G. G. [Russian Academy of Science, Novgorod, Russia; Heidinger, R. [Institut fur Materialforschung II, Karlsruhe, Germany; Piosczyk, B. [Institut fur Materialforschung II, Karlsruhe, Germany; Thumm, M. [Institut fur Materialforschung II, Karlsruhe, Germany; Rao, S. L. [Institute for Plasma Research, Gandhinagar, India; Sakamoto, K. [Japan Atomic Energy Agency (JAEA), Naka; Takahaski, K. [Japan Atomic Energy Agency (JAEA), Naka; Thumm, M. [Universituet Karlsruhe, Germany

2009-06-01T23:59:59.000Z

316

An iterated search for influence from the future on the Large Hadron Collider  

E-Print Network (OSTI)

We analyse an iterated version of Nielsen and Ninomiya (N&N)'s proposed card game experiment to search for a specific type of backward causation on the running of the Large Hadron Collider (LHC) at CERN. We distinguish "endogenous" and "exogenous" potential causes of failure of LHC and we discover a curious "cross-talk" between their respective probabilities and occurrence timescales when N&N-style backward causation is in effect. Finally, we note a kind of "statistical cosmic censorship" preventing the influence from the future from showing up in a statistical analysis of the iterated runs.

Iain Stewart

2007-12-05T23:59:59.000Z

317

Optimum cycle parameters of coal fired closed cycle gas turbine in regenerative and combined cycle configurations  

Science Conference Proceedings (OSTI)

This paper presents the methodology developed for the estimation of thermodynamic performance and reports the optimum cycle parameters of coal fired CCGT in regenerative and combined cycle configurations using air, helium and carbon dioxide as working gases. A rigorous approach has been followed for the determination of the cycle efficiency by assuming the specific heat of working gases as a continuous function of temperature for accurate estimation of cycle parameters. 14 refs.

Rao, J.S.

1982-01-01T23:59:59.000Z

318

Heavy Truck Duty Cycle (HTDC) Project OVERVIEW The Heavy Truck Duty Cycle (HTDC)  

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

(HTDC) Project (HTDC) Project OVERVIEW The Heavy Truck Duty Cycle (HTDC) Project is sponsored by the US Department of Energy's (DOE's) Office of FreedomCar and Vehicle Technologies. The project involves efforts to collect, analyze and archive data and information related to class -8 truck operation in real-world environments. Such data and information will be useful for supporting: energy efficiency technology evaluation efforts, the

319

An approach to iterative learning control for spatio-temporal dynamics using nD discrete linear systems models  

Science Conference Proceedings (OSTI)

Iterative Learning Control (ILC) is now well established in terms of both the underlying theory and experimental application. This approach is specifically targeted at cases where the same operation is repeated over a finite duration with resetting between ... Keywords: Explicit discretization, Iterative learning control, PDEs, nD linear systems

B?a?ej Cichy; Krzysztof Ga?kowski; Eric Rogers; Anton Kummert

2011-03-01T23:59:59.000Z

320

The Use of DIII-D as a Testbed for ITER ECH Transmission Line Comonents (A25064)  

E-Print Network (OSTI)

Proc. Of 3rd Tech. Mtg On Electron Cyclotron Resonance Heating Physics And Technology For ITER, Como, Italy, 2005, To Be Published In Proceedings3rd Technical Meeting on Electron Cyclotron Resonance Heating Physics and Technology for ITER Como, IT, 2005999610680

Callis, R.W.

2005-06-10T23:59:59.000Z

Note: This page contains sample records for the topic "involves iterative cycling" 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

The Effect of Process Topology and Load Balancing on Parallel Programming Models for SMP Clusters and Iterative Algorithms  

Science Conference Proceedings (OSTI)

This article focuses on the effect of both process topology and load balancing on various programming models for SMP clusters and iterative algorithms. More specifically, we consider nested loop algorithms with constant flow dependencies, that can be ... Keywords: MPI, OpenMP, SMP clusters, high performance computing, hybrid programming, iterative algorithms, parallel programming, tiling

Nikolaos Drosinos; Nectarios Koziris

2006-01-01T23:59:59.000Z

322

Physics and engineering results obtained with the ion cyclotron range of frequencies ITER-like antenna on JET  

SciTech Connect

This paper summarizes the operational experience of the ion cyclotron resonant frequency (ICRF) ITER-like antenna on JET aiming at substantially increasing the power density in the range of the requirements for ITER combined with load resiliency. An in-depth description of its commissioning, operational aspects and achieved performances is presented.

Durodie, F. [ERM-KMS, Association EURATOM-Belgian State, Brussels, Belgium; Nightingale, M. [EURATOM / UKAEA, Abingdon, UK; Mayoral, M. -L. [EURATOM / UKAEA, Abingdon, UK; Ongena, J. [ERM-KMS, Association EURATOM-Belgian State, Brussels, Belgium; Argouarch, A. [CEA Cadarache, St. Paul lex Durance, France; Berger-By, G. [CEA Cadarache, St. Paul lex Durance, France; Goulding, Richard Howell [ORNL

2012-01-01T23:59:59.000Z

323

Strategy for the practical utilization of thorium fuel cycles  

SciTech Connect

There has been increasing interest in the utilization of thorium fuel cycles in nuclear power reactors for the past few years. This is due to a number of factors, the chief being the recent emphasis given to increasing the proliferation resistance of reactor fuel cycles and the thorium cycle characteristic that bred /sup 233/U can be denatured with /sup 238/U (further, a high radioactivity is associated with recycle /sup 233/U, which increases fuel diversion resistance). Another important factor influencing interest in thorium fuel cycles is the increasing cost of U/sub 3/O/sub 8/ ores leading to more emphasis being placed on obtaining higher fuel conversion ratios in thermal reactor systems, and the fact that thorium fuel cycles have higher fuel conversion ratios in thermal reactors than do uranium fuel cycles. Finally, there is increasing information which indicates that fast breeder reactors have significantly higher capital costs than do thermal reactors, such that there is an economic advantage in the long term to have combinations of fast breeder reactors and high-conversion thermal reactors operating together. Overall, it appears that the practical, early utilization of thorium fuel cycles in power reactors requires commercialization of HTGRs operating first on stowaway fuel cycles, followed by thorium fuel recycle. In the longer term, thorium utilization involves use of thorium blankets in fast breeder reactors, in combination with recycling the bred /sup 233/U to HTGRs (preferably), or to other thermal reactors.

Kasten, P.R.

1978-01-01T23:59:59.000Z

324

The Kalina cycle and similar cycles for geothermal power production  

SciTech Connect

This report contains a brief discussion of the mechanics of the Kalina cycle and ideas to extend the concept to other somewhat different cycles. A modified cycle which has a potential heat rejection advantage but little or no performance improvement is discussed. Then, the results of the application of the Kalina cycle and the modified cycle to a geothermal application (360/degree/F resource) are discussed. The results are compared with published results for the Kalina cycle with high temperature sources and estimates about performance at the geothermal temperatures. Finally, the conclusions of this scoping work are given along with recommendations of the direction of future work in this area. 11 refs., 4 figs., 1 tab.

Bliem, C.J.

1988-09-01T23:59:59.000Z

325

A New Absorption Cycle: The Single-Effect Regenerative Absoprtion Refrigeration Cycle  

E-Print Network (OSTI)

REGENERATIVE ABSORPTION REFRIGERATION CYCLE ABSTRACT A new absorption cycle , using heat as the energy

Dao, K.

2011-01-01T23:59:59.000Z

326

Short Survey: Intelligent switching expert system for delayed coking unit based on iterative learning strategy  

Science Conference Proceedings (OSTI)

Delayed coking is the most effective process to decarbonize and demetallize heavy petroleum residues. However, it relies much on the field engineers' experiences and expertise in practice for operating the controllers effectively and compatibly in delayed ... Keywords: Delayed coking, Expert system, Intelligent control, Iterative learning

Xiaodong Yu; Yujie Wei; Dexian Huang; Yongheng Jiang; Bo Liu; Yihui Jin

2011-07-01T23:59:59.000Z

327

Double iterative optimisation for metabolic network-based drug target identification  

Science Conference Proceedings (OSTI)

The goal of drug discovery is to find molecules that manipulate enzymes in order to increase or decrease the production of desired compounds while incurring minimum side-effects. An important part of this problem is the identification of the target ... Keywords: E coli, bioinformatics, data mining, drug discovery, drug target identification, iterative optimisation, metabolic networks, target enzymes

Bin Song; Padmavati Sridhar; Tamer Kahveci; Sanjay Ranka

2009-05-01T23:59:59.000Z

328

Thirty states sign ITER nuclear fusion plant deal 1 hour, 28 minutes ago  

E-Print Network (OSTI)

than 30 countries signed a deal on Tuesday to build the world's most advanced nuclear fusion reactor nuclear reactors, but critics argue it could be at least 50 years before a commercially viable reactorThirty states sign ITER nuclear fusion plant deal 1 hour, 28 minutes ago Representatives of more

329

Exploiting phase inter-dependencies for faster iterative compiler optimization phase order searches  

Science Conference Proceedings (OSTI)

The problem of finding the most effective set and ordering of optimization phases to generate the best quality code is a fundamental issue in compiler optimization research. Unfortunately, the exorbitantly large phase order search spaces in current compilers ... Keywords: iterative compilation, optimization ordering, search space pruning

Michael R. Jantz; Prasad A. Kulkarni

2013-09-01T23:59:59.000Z

330

Iterative approach to the characteristic time for chemical reactions of type A + B ! C + D  

E-Print Network (OSTI)

The analytic solution for the kinetic description of binary reactions can be seen as the continuum version of a basic discrete iterate mapping. This fact allows a clear definition of the reaction characteristic time which takes the backward effect into account.

R. Aldrovandi

2013-10-13T23:59:59.000Z

331

Requirements for US regulatory approval of the International Thermonuclear Experimental Reactor (ITER)  

SciTech Connect

The International Thermonuclear Experimental Reactor (ITER) is the first fusion machine that will have sufficient decay heat and activation product inventory to pose potential nuclear safety concerns. As a result, nuclear safety and environmental issues will be much more important in the approval process for the design, siting, construction, and operation of ITER in the United States than previous fusion devices, such as the Tokamak Fusion Test Reactor. The purpose of this report is (a) to provide an overview of the regulatory approval process for a Department of Energy (DOE) nuclear facility; (b) to present the dose limits used by DOE to protect workers, the public, and the environment from the risks of exposure to radiation and hazardous materials; (c) to discuss some key nuclear safety-related issues that must be addressed early in the Engineering Design Activities (EDA) to obtain regulatory approval; and (d) to provide general guidelines to the ITER Joint Central Team (JCT) concerning the development of a regulatory framework for the ITER project.

Petti, D.A.; Haire, J.C.

1993-12-01T23:59:59.000Z

332

An iterative solution to the four-peg Tower of Hanoi problem  

Science Conference Proceedings (OSTI)

One of the variations of the Towers of Hanoi puzzle allows for p pegs, and for four pegs the solution to this variation is shown to have a simple structure which can be used to derive an iterative solution to the problem.

Appie van de Liefvoort

1990-01-01T23:59:59.000Z

333

Design, manufacture and initial operation of the beryllium components of the JET ITER-like wall  

E-Print Network (OSTI)

The aim of the JET ITER-like Wall Project was to provide JET with the plasma facing material combination now selected for the DT phase of ITER (bulk beryllium main chamber limiters and a full tungsten divertor) and, in conjunction with the upgraded neutral beam heating system, to achieve ITER relevant conditions. The design of the bulk Be plasma facing components had to be compatible with increased heating power and pulse length, as well as to reuse the existing tile supports originally designed to cope with disruption loads from carbon based tiles and be installed by remote handling. Risk reduction measures (prototypes, jigs, etc) were implemented to maximize efficiency during the shutdown. However, a large number of clashes with existing components not fully captured by the configuration model occurred. Restarting the plasma on the ITER-like Wall proved much easier than for the carbon wall and no deconditioning by disruptions was observed. Disruptions have been more threatening than expected due to the redu...

Riccardo, V; Matthews, G F; Nunes, I; Thompson, V; Villedieu, E; Contributors, JET EFDA

2013-01-01T23:59:59.000Z

334

Annual Report of the EURATOM/CCFE Fusion Programme 2010/11 8 ITER Systems  

E-Print Network (OSTI)

to the ITER heating, diagnostic and remote handling systems in particular. Fusion for Energy (F4E) content, the ion temperature and flow; · Remote handling system, in particular the design for the Neutral Remote Handling requirements; · Full manufacturing / assembly assessments. Figure 8.5: Development

335

Annual Report of the EURATOM/CCFE Fusion Programme 2011/12 8 ITER Systems  

E-Print Network (OSTI)

and Remote Handling etc.) in Europe; 8ITERSystems · Seek to play other design roles in R&D of ITER specialist the helium (ash) content, the ion temperature and flow; · Remote handling system, in particular the design Dump and Calorimeter designs. 8.2.3 REMOTE HANDLING CCFE was awarded a grant to complete the conceptual

336

ITER Engineering Design Activities -R & DITER-In-Vessel Remote Handling  

E-Print Network (OSTI)

ITER Engineering Design Activities - R & DITER- In-Vessel Remote Handling Blanket Module Remote Handling Project (L-6) Divertor Remote Handling Project (L-7) Objective To develop and demonstrate handling equipment, port handling equipment, auxiliary remote handling tools and a blanket mockup structure

337

Weight optimisation for iterative distributed model predictive control applied to power networks  

Science Conference Proceedings (OSTI)

This paper presents a weight tuning technique for iterative distributed Model Predictive Control (MPC). Particle Swarm Optimisation (PSO) is used to optimise both the weights associated with disturbance rejection and those associated with achieving consensus ... Keywords: Distributed model predictive control, Multi-agent, Particle swarm optimisation, Power networks, Smart grids, Weight tuning

Paul Mc Namara; Rudy R. Negenborn; Bart De Schutter; Gordon Lightbody

2013-01-01T23:59:59.000Z

338

TF Ripple Loss of Alpha Particles from the ITER Interim Design: Simulation and Theory  

E-Print Network (OSTI)

and potentially severe localized wall damage in fusion reactors. In this paper we show guiding center code (GC, substantial ad hoc normalization factors were required. This is understandable, since the loss criterion used 12, 1995, ITER JCT, San Diego, CA (private com- munication, S. Putvinski). 2: R. B. White, et al

339

THE STRUCTURE OF TWO-PARABOLIC SPACE: PARABOLIC DUST AND ITERATION.  

E-Print Network (OSTI)

THE STRUCTURE OF TWO-PARABOLIC SPACE: PARABOLIC DUST AND ITERATION. JANE GILMAN Abstract. A non-elementary M¨obius group generated by two- parabolics is determined up to conjugation by one complex para] to obtain an additional struc- ture for the parameter space, which we term the two-parabolic space

Gilman, Jane

340

Iterative methods for neutron transport eigenvalue Fynn Scheben and Ivan G. Graham  

E-Print Network (OSTI)

. Numer. Anal., 26 (1989), pp. 66­87. [3] G. I. Bell and S. Glasstone, Nuclear Reactor Theory, Reinhold iterative methods for computing criticality in nuclear reactors. In general this requires the solution and optimal performance of existing nuclear reactors is an important task of great environmental significance

Graham, Ivan

Note: This page contains sample records for the topic "involves iterative cycling" 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

Bandwidth Allocation for Iterative Data-Dependent E-science Applications  

Science Conference Proceedings (OSTI)

We develop a novel framework for supporting e-Science applications that require streaming of information between sites. Using a Synchronous Dataflow (SDF) model, our framework incorporates the communication times inherent in large scale distributed applications, ... Keywords: Bandwidth allocation, Throughput, Iterative datadependent, E-Science

Eun-Sung Jung; Sanjay Ranka; Sartaj Sahni

2010-05-01T23:59:59.000Z

342

Principal component analysis of binary data by iterated singular value decomposition  

Science Conference Proceedings (OSTI)

The maximum-likelihood estimates of a principal component analysis on the logit or probit scale are computed using majorization algorithms that iterate a sequence of weighted or unweighted singular value decompositions. The relation with similar methods ... Keywords: Applications to social sciences, Binary data, Factor analysis, Item response models, Multivariate analysis

Jan de Leeuw

2006-01-01T23:59:59.000Z

343

Is the Standard Monte Carlo Power Iteration Approach the Wrong Approach? Part 2  

Science Conference Proceedings (OSTI)

The recent work 'Is the Standard Monte Carlo Power Iteration Approach the Wrong Approach?' speculated that the second eigenfunction could be built using essentially the same 'building brick' approach that obtained the first eigenfunction in LA-UR-12-21928. This note shows that the speculation was at least partially correct, but not complete.

Booth, Thomas E. [Los Alamos National Laboratory

2012-07-11T23:59:59.000Z

344

The Iterative Unitary Matrix Multiply Method and Its Application to Quantum Kicked Rotator  

E-Print Network (OSTI)

We use the iterative unitary matrix multiply method to calculate the long time behavior of the resonant quantum kicked rotator with a large denominator. The delocalization time is exponentially large. The quantum wave delocalizes through degenerate states. At last we construct a nonresonant quantum kicked rotator with delocalization.

Tao Ma

2007-09-14T23:59:59.000Z

345

ccsd-00002019,version1-18Oct2004 Stabilization of Burn Conditions in an ITER FEAT  

E-Print Network (OSTI)

,i 92.8 MW ; (6) these limits contain the required values for steady state operation for the range reactions together with an external RF electron and ion heating, with a small contribution of joule heating will constitute the operating point for the ITER-FEAT like tokamak reactor used in this work.[5,6] Here, we

Paris-Sud XI, Université de

346

The Linear Stability Properties of Medium- to High- n TAEs in ITER  

SciTech Connect

This document provides a detailed report on the successful completion of the DOE OFES Theory Milestone for FY2007: Improve the simulation resolution of linear stability properties of Toroidal Alfvén Eigenmodes (TAE) driven by energetic particles and neutral beams in ITER by increasing the numbers of toroidal modes used to 15.

Gorelenkov, N N; Budny, R V; Kessel, C E; Kramer, G J; McCune, D; Manickam, J; Nazikian, R

2008-02-14T23:59:59.000Z

347

An efficient preconditioned iterative solution of fully-coupled elastohydrodynamic lubrication problems  

Science Conference Proceedings (OSTI)

This paper presents the fast preconditioned iterative solution to large sparse linear systems arising from the application of Newton and quasi-Newton methods to fully coupled elastohydrodynamic lubrication line and point contact problems. The new blockwise ... Keywords: Elastohydrodynamic lubrication, Finite element method, Fully coupled approach, Linear elasticity, Multigrid, Preconditioned GMRES

Sarfraz Ahmed; Christopher E. Goodyer; Peter K. Jimack

2012-05-01T23:59:59.000Z

348

HEART SEGMENTATION WITH AN ITERATIVE CHAN-VESE OLIVIER ROUSSEAU, YVES BOURGAULT  

E-Print Network (OSTI)

HEART SEGMENTATION WITH AN ITERATIVE CHAN-VESE ALGORITHM OLIVIER ROUSSEAU, YVES BOURGAULT Abstract. This paper presents 2D and 3D applications of the Chan-Vese model to heart and trachea segmentation. We is to segment the heart muscle from high resolution CT scans of the thorax and to produce meshes

Paris-Sud XI, Université de

349

Fusion Engineering and Design 81 (2006) 393405 Breeding Blanket Modules testing in ITER  

E-Print Network (OSTI)

to be assessed. TBM replacement occurs in the ITER hot cell, where the whole TBMs/shield plug system is remotely HCCB TBM). 6. Remote handling, maintenance, and safety considerations The general assumed rule. A view of a possible port cell volume occupation is shown in Fig. 14. Either the addition of a hot cell

Abdou, Mohamed

350

Fusion Engineering and Design 46 (1999) 207220 ITER divertor, design issues and research and development  

E-Print Network (OSTI)

of the PFCs is performed ex-vessel in a hot cell, where it is anticipated the refurbishment of 60 cassettes, November 1997. [19] E. Martin, et al., Design of the ITER Divertor Remote Handling System; 19th SOFT, tritium inventory, impurity control, armour lifetime, electromagnetic loads, diagnostics, and remote

Raffray, A. René

351

Life Cycle Analysis: Power Studies Compilation Report  

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

Hour LC Life Cycle LCA Life Cycle Analysis LCC Life Cycle Costing LCI Life Cycle Inventory LCOE Levelized Cost of Delivered Electricity LNB Low NO x Burner LNG Liquefied...

352

Nutrient Cycling Study  

DOE Green Energy (OSTI)

The particular goal of this study is to develop measurement techniques for understanding how consortia of organisms from geothermal facilities utilize sulfur and iron for metabolic activity; and in turn, what role that activity plays in initiating or promoting the development of a biofilm on plant substrates. Sulfur cycling is of interest because sulfur is produced in the resource. Iron is found in some of the steel formulations used in plant components and is also added as chemical treatment for reducing sulfide emissions from the plants. This report describes the set-up and operation of a bioreactor for evaluating the response of colonies of geothermal organisms to changes in nutrient and environmental conditions. Data from initial experiments are presented and plans for future testing is discussed.

Peter A. Pryfogle

2005-09-01T23:59:59.000Z

353

Direct fired power cycle  

SciTech Connect

A method for implementing a thermodynamic cycle is described comprising the steps of: expanding a gaseous working stream to transform its energy into usable form; removing from the expanded gaseous working stream a withdrawal stream; combining the withdrawal stream with a lean stream, having a higher content of a higher-boiling component than is contained in the withdrawal stream, to form a composite stream; condensing the composite stream to provide heat; separating the composite stream to form a liquid stream; forming an oncoming liquid working stream that evaporates at a temperature lower than the temperature at which the composite stream condenses; and evaporating the oncoming liquid working stream, using the heat produced by condensing the composite stream, to form the gaseous working stream.

Kalina, A.I.

1988-03-22T23:59:59.000Z

354

Twin-Screw Extruder Development for the ITER Pellet Injection System  

SciTech Connect

The ITER pellet injection system is comprised of devices to form and accelerate pellets, and will be connected to inner wall guide tubes for fueling, and outer wall guide tubes for ELM pacing. An extruder will provide a stream of solid hydrogen isotopes to a secondary section, where pellets are cut and accelerated with a gas gun into the plasma. The ITER pellet injection system is required to provide a plasma fueling rate of 120 Pa-m3/s (900 mbar-L/s) and durations of up to 3000 s. The fueling pellets will be injected at a rate up to 10 Hz and pellets used to trigger ELMs will be injected at higher rates up to 20 Hz. A twin-screw extruder for the ITER pellet injection system is under development at the Oak Ridge National Laboratory. A one-fifth ITER scale prototype has been built and has demonstrated the production of a continuous solid deuterium extrusion. The 27 mm diameter, intermeshed, counter-rotating extruder screws are rotated at a rate up to ?5 rpm. Deuterium gas is pre-cooled and liquefied and solidified in separate extruder barrels. The precooler consists of a deuterium gas filled copper coil suspended in a separate stainless steel vessel containing liquid nitrogen. The liquefier is comprised of a copper barrel connected to a Cryomech AL330 cryocooler, which has a machined helical groove surrounded by a copper jacket, through which the pre-cooled deuterium condenses. The lower extruder barrel is connected to a Cryomech GB-37 cryocooler to solidify the deuterium (at ?15 K) before it is forced through the extruder die. The die forms the extrusion to a 3 mm x 4 mm rectangular cross section. Design improvements have been made to improve the pre-cooler and liquefier heat exchangers, to limit the loss of extrusion through gaps in the screws. This paper will describe the design improvements for the next iteration of the extruder prototype.

Meitner, Steven J [ORNL; Baylor, Larry R [ORNL; Combs, Stephen Kirk [ORNL; Fehling, Dan T [ORNL; McGill, James M [ORNL; Rasmussen, David A [ORNL; Leachman, J. W. [University of Wisconsin, Madison

2009-01-01T23:59:59.000Z

355

Non-iterative joint decoding and signal processing: universal coding approach for channels with memory  

E-Print Network (OSTI)

A non-iterative receiver is proposed to achieve near capacity performance on intersymbol interference (ISI) channels. There are two main ingredients in the proposed design. i) The use of a novel BCJR-DFE equalizer which produces optimal soft estimates of the inputs to the ISI channel given all the observations from the channel and L past symbols exactly, where L is the memory of the ISI channel. ii) The use of an encoder structure that ensures that L past symbols can be used in the DFE in an error free manner through the use of a capacity achieving code for a memoryless channel. Computational complexity of the proposed receiver structure is less than that of one iteration of the turbo receiver. We also provide the proof showing that the proposed receiver achieves the i.i.d. capacity of any constrained input ISI channel. This DFE-based receiver has several advantages over an iterative (turbo) receiver, such as low complexity, the fact that codes that are optimized for memoryless channels can be used with channels with memory, and finally that the channel does not need to be known at the transmitter. The proposed coding scheme is universal in the sense that a single code of rate r; optimized for a memoryless channel, provides small error probability uniformly across all AWGN-ISI channels of i.i.d. capacity less than r: This general principle of a proposed non-iterative receiver also applies to other signal processing functions, such as timing recovery, pattern-dependent noise whiten ing, joint demodulation and decoding etc. This makes the proposed encoder and receiver structure a viable alternative to iterative signal processing. The results show significant complexity reduction and performance gain for the case of timing recovery and patter-dependent noise whitening for magnetic recording channels.

Nangare, Nitin Ashok

2003-05-01T23:59:59.000Z

356

A sequential partly iterative approach for multicomponent reactive transport with CORE2D  

SciTech Connect

CORE{sup 2D} V4 is a finite element code for modeling partly or fully saturated water flow, heat transport and multicomponent reactive solute transport under both local chemical equilibrium and kinetic conditions. It can handle coupled microbial processes and geochemical reactions such as acid-base, aqueous complexation, redox, mineral dissolution/precipitation, gas dissolution/exsolution, ion exchange, sorption via linear and nonlinear isotherms, sorption via surface complexation. Hydraulic parameters may change due to mineral precipitation/dissolution reactions. Coupled transport and chemical equations are solved by using sequential iterative approaches. A sequential partly-iterative approach (SPIA) is presented which improves the accuracy of the traditional sequential noniterative approach (SNIA) and is more efficient than the general sequential iterative approach (SIA). While SNIA leads to a substantial saving of computing time, it introduces numerical errors which are especially large for cation exchange reactions. SPIA improves the efficiency of SIA because the iteration between transport and chemical equations is only performed in nodes with a large mass transfer between solid and liquid phases. The efficiency and accuracy of SPIA are compared to those of SIA and SNIA using synthetic examples and a case study of reactive transport through the Llobregat Delta aquitard in Spain. SPIA is found to be as accurate as SIA while requiring significantly less CPU time. In addition, SPIA is much more accurate than SNIA with only a minor increase in computing time. A further enhancement of the efficiency of SPIA is achieved by improving the efficiency of the Newton-Raphson method used for solving chemical equations. Such an improvement is obtained by working with increments of log-concentrations and ignoring the terms of the Jacobian matrix containing derivatives of activity coefficients. A proof is given for the symmetry and non-singularity of the Jacobian matrix. Numerical analyses performed with synthetic examples confirm that these modifications improve the efficiency and convergence of the iterative algorithm.

Samper, J.; Xu, T.; Yang, C.

2008-11-01T23:59:59.000Z

357

Small Mock-Up Fabrication and High Heat Flux Test for Preparing the 2nd Qualification of the ITER Blanket First Wall  

Science Conference Proceedings (OSTI)

ITER Systems / Proceedings of the Nineteenth Topical Meeting on the Technology of Fusion Energy (TOFE) (Part 1)

Dong Won Lee; Suk Kwon Kim; Young-Dug Bae; Yang Il Jung; Jeong Yong Park; Yong Hwan Jeong; Byung Yoon Kim

358

Advanced regenerative absorption refrigeration cycles  

DOE Patents (OSTI)

Multi-effect regenerative absorption cycles which provide a high coefficient of performance (COP) at relatively high input temperatures. An absorber-coupled double-effect regenerative cycle (ADR cycle) (10) is provided having a single-effect absorption cycle (SEA cycle) (11) as a topping subcycle and a single-effect regenerative absorption cycle (1R cycle) (12) as a bottoming subcycle. The SEA cycle (11) includes a boiler (13), a condenser (21), an expansion device (28), an evaporator (31), and an absorber (40), all operatively connected together. The 1R cycle (12) includes a multistage boiler (48), a multi-stage resorber (51), a multisection regenerator (49) and also uses the condenser (21), expansion device (28) and evaporator (31) of the SEA topping subcycle (11), all operatively connected together. External heat is applied to the SEA boiler (13) for operation up to about 500 degrees F., with most of the high pressure vapor going to the condenser (21) and evaporator (31) being generated by the regenerator (49). The substantially adiabatic and isothermal functioning of the SER subcycle (12) provides a high COP. For higher input temperatures of up to 700 degrees F., another SEA cycle (111) is used as a topping subcycle, with the absorber (140) of the topping subcycle being heat coupled to the boiler (13) of an ADR cycle (10). The 1R cycle (12) itself is an improvement in that all resorber stages (50b-f) have a portion of their output pumped to boiling conduits (71a-f) through the regenerator (49), which conduits are connected to and at the same pressure as the highest pressure stage (48a) of the 1R multistage boiler (48).

Dao, Kim (14 Nace Ave., Piedmont, CA 94611)

1990-01-01T23:59:59.000Z

359

Closed-cycle Retrofit Study  

Science Conference Proceedings (OSTI)

EPRI is investigating implications of a potential U.S. Environmental Protection Agency (EPA) Clean Water Act 316(b) rulemaking that would establish "Best Technology Available" (BTA) based on closed-cycle cooling retrofits for facilities with once-through cooling. This report focuses on estimated costs associated with closed-cycle cooling system retrofits that include: 1) capital costs, 2) energy required to operate the closed-cycle system, 3) heat rate penalty, and 4) extended downtime required to retrof...

2011-01-31T23:59:59.000Z

360

International Nuclear Fuel Cycle Fact Book. Revision 5  

SciTech Connect

This Fact Book has been compiled in an effort to provide: (1) an overview of worldwide nuclear power and fuel cycle programs; and (2) current data concerning fuel cycle and waste management facilities, R and D programs, and key personnel in countries other than the United States. Additional information on each country's program is available in the International Source Book: Nuclear Fuel Cycle Research and Development, PNL-2478, Rev. 2. The Fact Book is organized as follows: (1) Overview section - summary tables which indicate national involvement in nuclear reactor, fuel cycle, and waste management development activities; (2) national summaries - a section for each country which summarizes nuclear policy, describes organizational relationships and provides addresses, names of key personnel, and facilities information; (3) international agencies - a section for each of the international agencies which has significant fuel cycle involvement; (4) energy supply and demand - summary tables, including nuclear power projections; (5) fuel cycle - summary tables; and (6) travel aids international dialing instructions, international standard time chart, passport and visa requirements, and currency exchange rate.

Harmon, K.M.; Lakey, L.T.; Leigh, I.W.; Jeffs, A.G.

1985-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "involves iterative cycling" 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

International nuclear fuel cycle fact book. Revision 4  

SciTech Connect

This Fact Book has been compiled in an effort to provide (1) an overview of worldwide nuclear power and fuel cycle programs and (2) current data concerning fuel cycle and waste management facilities, R and D programs, and key personnel in countries other than the United States. Additional information on each country's program is available in the International Source Book: Nuclear Fuel Cycle Research and Development, PNL-2478, Rev. 2. The Fact Book is organized as follows: (1) Overview section - summary tables which indicate national involvement in nuclear reactor, fuel cycle, and waste management development activities; (2) national summaries - a section for each country which summarizes nuclear policy, describes organizational relationships and provides addresses, names of key personnel, and facilities information; (3) international agencies - a section for each of the international agencies which has significant fuel cycle involvement; (4) energy supply and demand - summary tables, including nuclear power projections; (5) fuel cycle - summary tables; and (6) travel aids - international dialing instructions, international standard time chart, passport and visa requirements, and currency exchange rate.

Harmon, K.M.; Lakey, L.T.; Leigh, I.W.

1984-03-01T23:59:59.000Z

362

Carbon Cycle 2.0  

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

Carbon Cycle 2.0 Carbon Cycle 2.0 Pioneering science for sustainable energy solutions Artificial Photosynthesis Energy Storage Combustion Carbon Capture & Storage Developing World Efficiency Photovoltaics Biofuels Energy Analysis Climate Modeling Carbon Cycle 2.0 is... 1. A vision for * a global energy system integrated with the Earth's natural carbon cycles * an interactive Berkeley Lab environment with a shared sense of purpose 2. A program development plan that will allow us to deepen our capabilities and provide more opportunities to have impact 3. An attempt to integrate our basic research with applications using models of technology deployment constraints 4. Set of internal activities aimed at priming the effort

363

Optimization of Air Conditioning Cycling.  

E-Print Network (OSTI)

??Systems based on the vapor compression cycle are the most widely used in a variety of air conditioning applications. Despite the vast growth of modern… (more)

Seshadri, Swarooph

2012-01-01T23:59:59.000Z

364

Award Cycle at a Glance  

Science Conference Proceedings (OSTI)

Award Cycle at a Glance. 2013. Eligibility Certification February 19 (with a nomination to the Board of Examiners). April 2 (without a nomination). ...

2013-07-22T23:59:59.000Z

365

Green Building- Efficient Life Cycle  

E-Print Network (OSTI)

Energy saving does not just apply to traffic, production or agriculture. Buildings are also contributing to the climate change. The focus here is on the energy they use and on their CO2 emissions. Each year, Siemens invests more than two billion euros in the appropriate research and development. For customers, this means that Siemens is already providing them with energy efficient solutions that save resources and reduce emissions. Siemens Real Estate (SRE) has taken on the task of ensuring that Siemens AG will become 20 percent more energy efficient by 2011, and it has turned an efficiency program for existing real estate, which has been in existence since 2005, into an integrated green building initiative. This initiative comprises the components “Sustainable Building Design”, “Life Cycle Cost Analysis”, “Green Building Certification” and “Natural Resources Management”. These components are deliberately arranged around the life cycle of the real estate concerned. This allows a different emphasis to be placed on the different questions in each project phase and each phase of a building’s life and for them to be answered in a targeted manner. “Sustainable Building Design” comes into effect during the tasking and preliminary planning phase of a building project; and, by providing a specially developed sustainability manual, it helps with the definition of target values and the drawing up of efficiency strategies for the planning of the building. The manual epitomizes, and sets out clearly, the attitude of SRE to all building-specific sustainability matters. In addition, it is used in the offering of rewards for project competitions. As a result, through a selection of different energy-efficiency measures that have been roughly conceived beforehand, the primary energy consumption can already be restricted in the project definition phase. “Life Cycle Cost Analysis” comes into effect when the blueprint for buildings is being drawn up. Up to now, when components and systems were being chosen, the main focus was usually on the investment costs involved. By using a cost tool developed specifically to meet the needs of the company, SRE will in future be able to estimate the component-specific utilization costs – such as cleaning, maintenance, and the use of energy – at an early planning stage. “Green Building Certification” is used in building projects during the planning and implementation phase, and it thus ensures the quality of the new real estate over the long term. Siemens is implementing the Green Building Program of the European Commission in new building projects and renovation work in EU countries. In all other countries that are not taking part in the EU Green Building Program, SRE uses certification in accordance with LEED (Leadership in Energy and Environmental Design). In the LEED certification, a transparent and easy-to-use catalog of criteria is employed to make an assessment of the use of energy and other aspects of sustainability, such as the selection of the plot of land, the efficient use of water, the quality of air within buildings, and the selection of materials. This ensures that a neutral and independent assessment is made of all new building and large-scale renovation projects. The action program “Natural Resources Management” rounds off the range of measures in the area of existing real estate. The aim of the program is to identify and highlight all latent efficiency potential in existing buildings. This includes, for instance, modernizing the control equipment used for the heating and ventilation systems. This entails replacing electrical power units with more efficient models, and retrofitting fans and pumps with frequency converters. Sixty buildings have now been inspected, and savings of almost eight million Euros have been achieved. The average payback period is less than two years. One example of this is an old Siemens building from the 1970s at the Munich-Perlach site. Through energy optimization, it has been possible to cu

Kohns, R.

2008-10-01T23:59:59.000Z

366

Multivariable cycle-to-cycle of an injection molding process  

E-Print Network (OSTI)

Cycle-to-Cycle (CtC) feedback control has been studied extensively with increasing demands on the precision and quality of manufactured parts. Single input-Single output has been studied as the basis of CtC feedback control. ...

Vanderpuije, Curtis N

2005-01-01T23:59:59.000Z

367

Advanced Nuclear Fuel Cycles -- Main Challenges and Strategic Choices  

Science Conference Proceedings (OSTI)

This report presents the results of a critical review of the technological challenges to the growth of nuclear energy, emerging advanced technologies that would have to be deployed, and fuel cycle strategies that could conceivably involve interim storage, plutonium recycling in thermal and fast reactors, reprocessed uranium recycling, and transmutation of minor actinide elements and fission products before eventual disposal of residual wastes.

2010-09-02T23:59:59.000Z

368

Integrated gasification combined cycle - a view to the future  

SciTech Connect

DOE is involved in research, development, and demonstration of Integrated Gasification Combined Cycle because of a strong belief that it will result in widespread commercialization that will be of great benefit to this nation. METC`s long-range vision comprises (1) product goals that require improvements to known technical advantages, and (2) market goals that are based on expectations of market pull.

Schmidt, D.K.

1994-10-01T23:59:59.000Z

369

Detection of the Climate Response to the Solar Cycle  

Science Conference Proceedings (OSTI)

Optimal space–time signal processing is used to infer the amplitude of the large-scale, near-surface temperature response to the, “11 year” solar cycle. The estimation procedure involves the following stops. 1) By correlating 14 years of monthly ...

Mark J. Stevens; Gerald R. North

1996-09-01T23:59:59.000Z

370

Biomass Gasification Combined Cycle  

DOE Green Energy (OSTI)

Gasification combined cycle continues to represent an important defining technology area for the forest products industry. The ''Forest Products Gasification Initiative'', organized under the Industry's Agenda 2020 technology vision and supported by the DOE ''Industries of the Future'' program, is well positioned to guide these technologies to commercial success within a five-to ten-year timeframe given supportive federal budgets and public policy. Commercial success will result in significant environmental and renewable energy goals that are shared by the Industry and the Nation. The Battelle/FERCO LIVG technology, which is the technology of choice for the application reported here, remains of high interest due to characteristics that make it well suited for integration with the infrastructure of a pulp production facility. The capital cost, operating economics and long-term demonstration of this technology area key input to future economically sustainable projects and must be verified by the 200 BDT/day demonstration facility currently operating in Burlington, Vermont. The New Bern application that was the initial objective of this project is not currently economically viable and will not be implemented at this time due to several changes at and around the mill which have occurred since the inception of the project in 1995. The analysis shows that for this technology, and likely other gasification technologies as well, the first few installations will require unique circumstances, or supportive public policies, or both to attract host sites and investors.

Judith A. Kieffer

2000-07-01T23:59:59.000Z

371

The closed fuel cycle  

Science Conference Proceedings (OSTI)

Available in abstract form only. Full text of publication follows: The fast growth of the world's economy coupled with the need for optimizing use of natural resources, for energy security and for climate change mitigation make energy supply one of the 21. century most daring challenges. The high reliability and efficiency of nuclear energy, its competitiveness in an energy market undergoing a new oil shock are as many factors in favor of the 'renaissance' of this greenhouse gas free energy. Over 160,000 tHM of LWR1 and AGR2 Used Nuclear Fuel (UNF) have already been unloaded from the reactor cores corresponding to 7,000 tons discharged per year worldwide. By 2030, this amount could exceed 400,000 tHM and annual unloading 14,000 tHM/year. AREVA believes that closing the nuclear fuel cycle through the treatment and recycling of Used Nuclear Fuel sustains the worldwide nuclear power expansion. It is an economically sound and environmentally responsible choice, based on the preservation of natural resources through the recycling of used fuel. It furthermore provides a safe and secure management of wastes while significantly minimizing the burden left to future generations. (authors)

Froment, Antoine; Gillet, Philippe [AREVA NC (France)

2007-07-01T23:59:59.000Z

372

Nuclear fuel cycle information workshop  

SciTech Connect

This overview of the nuclear fuel cycle is divided into three parts. First, is a brief discussion of the basic principles of how nuclear reactors work; second, is a look at the major types of nuclear reactors being used and world-wide nuclear capacity; and third, is an overview of the nuclear fuel cycle and the present industrial capability in the US.

1983-01-01T23:59:59.000Z

373

Reading Comprehension - The Water Cycle  

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

The Water Cycle The Water Cycle Evaporation, Condensation and Precipitation The _________ moon sun water clouds evaporates _________ fish oceans rain water from lakes and oceans. As the air rises, it cools. The water vapor condenses into tiny droplets of _________ evaporation clouds water sunshine . The droplets crowd together and form a _________ cloud lake storm precipitation . Wind blows the _________ rain sun droplet cloud towards the land. The tiny droplets join together and fall as precipitation to the _________ river lake ground cloud . The water soaks into the ground and collects in _________ rivers and lakes oceans and clouds jars and cups plants and animals . The _________ storm cycle river house that never ends has started again! A water cycle diagram. Use the diagram to identify the different parts of the water cycle:

374

CMVRTC: Heavy Truck Duty Cycle  

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

heavy truck duty cycle (HTDC) project heavy truck duty cycle (HTDC) project OVERVIEW The Heavy Truck Duty Cycle (HTDC) Project was initiated in 2004 and is sponsored by the US Department of Energy's (DOE's) Office of FreedomCar and Vehicle Technologies Program. ORNL designed the research program to generate real-world-based duty cycle data from trucks operating in long-haul operations and was designed to be conducted in three phases: identification of parameters to be collected, instrumentation and pilot testing, identification of a real-world fleet, design of the data collection suite and fleet instrumentation, and data collection, analysis, and development of a duty cycle generation tool (DCGT). ANL logo dana logo michelin logo Schrader logo This type of data will be useful for supporting energy efficiency

375

An iterative procedure to obtain inverse response functions for thick-target correction of measured charged-particle spectra  

E-Print Network (OSTI)

A new method for correcting charged-particle spectra for thick target effects is described. Starting with a trial function, inverse response functions are found by an iterative procedure. The variances corresponding to the measured spectrum are treated similiarly and in parallel. Oscillations of the solution are avoided by rebinning the data to finer bins during a correction iteration and back to the original or wider binning after each iteration. This thick-target correction method has been used for data obtained with the MEDLEY facility at the The Svedberg Laboratory, Uppsala, Sweden, and is here presented in detail and demonstrated for two test cases.

S. Pomp; U. Tippawan

2006-08-25T23:59:59.000Z

376

Coupling characteristics of the ITER relevant lower hybrid antenna in Tore Supra: experiments and modelling  

Science Conference Proceedings (OSTI)

A new concept of lower hybrid antenna for current drive has been proposed for ITER [Bibet et al, Nuclear Fusion 1995]: the Passive Active Multijunction (PAM) antenna that relies on a periodic combination of active and passive waveguides. An actively cooled PAM antenna at 3.7 GHz has been recently installed on the tokamak Tore Supra. The paper summarizes the comprehensive experimental characterization of the linear coupling properties of the PAM antenna to the Tore Supra plasmas. These experimental results are systematically compared with the linear wave coupling theory via the linear ALOHA code. Good agreement between experimental results and ALOHA have been obtained. The detailed validation of the coupling modelling is an important step toward the validation of the PAM concept in view of further optimizing the electromagnetic properties of the future ITER antenna.

Preynas, M.; Ekedahl, A.; Fedorczak, N.; Goniche, M.; Guilhem, D.; Gunn, J. P.; Hillairet, J.; Litaudon, X. [CEA, IRFM, 13108 Saint Paul lez Durance (France); Associacao Euratom-IST, Centro de Fusao Nuclear 1049-001 Lisboa (Portugal)

2011-12-23T23:59:59.000Z

377

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

DOE Green Energy (OSTI)

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

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

1990-09-01T23:59:59.000Z

378

Hybrid preconditioning for iterative diagonalization of ill-conditioned generalized eigenvalue problems in electronic structure calculations  

E-Print Network (OSTI)

The iterative diagonalization of a sequence of large ill-conditioned generalized eigenvalue problems is a computational bottleneck in quantum mechanical methods employing a nonorthogonal basis for {\\em ab initio} electronic structure calculations. We propose a hybrid preconditioning scheme to effectively combine global and locally accelerated preconditioners for rapid iterative diagonalization of such eigenvalue problems. In partition-of-unity finite-element (PUFE) pseudopotential density-functional calculations, employing a nonorthogonal basis, we show that the hybrid preconditioned block steepest descent method is a cost-effective eigensolver, outperforming current state-of-the-art global preconditioning schemes, and comparably efficient for the ill-conditioned generalized eigenvalue problems produced by PUFE as the locally optimal block preconditioned conjugate-gradient method for the well-conditioned standard eigenvalue problems produced by planewave methods.

Cai, Yunfeng; Pask, John E; Sukumar, N

2013-01-01T23:59:59.000Z

379

Assessment of database for interaction of tritium with ITER plasma facing materials  

SciTech Connect

The present work surveys recent literature on hydrogen isotope interactions with Be, SS and Inconels, Cu, C, and V, and alloys of Cu and V. The goals are (1) to provide input to the International Thermonuclear Experimental Reactor (ITER) team to help with tritium source term estimates for the Early Safety and Environmental Characterization Study and (2) to provide guidance for planning additional research that will be needed to fill gaps in the present materials database. Properties of diffusivity, solubility, permeability, chemical reactions, Soret effect, recombination coefficient, surface effects, trapping, porosity, layered structures, interfaces, and oxides are considered. Various materials data are tabulated, and a matrix display shows an assessment of the quality of the data available for each main property of each material. Recommendations are made for interim values of diffusivity and solubility to be used, pending further discussion by the ITER community.

Dolan, T.J.; Anderl, R.A.

1994-09-01T23:59:59.000Z

380

Toward a design for the ITER plasma shape and stability control system  

SciTech Connect

A design strategy for an integrated shaping and stability control algorithm for ITER is described. This strategy exploits the natural multivariable nature of the system so that all poloidal field coils are used to simultaneously control all regulated plasma shape and position parameters. A nonrigid, flux-conserving linearized plasma response model is derived using a variational procedure analogous to the ideal MHD Extended Energy Principle. Initial results are presented for the non-rigid plasma response model approach applied to an example DIII-D equilibrium. For this example, the nonrigid model is found to yield a higher passive growth rate than a rigid current-conserving plasma response model. Multivariable robust controller design methods are discussed and shown to be appropriate for the ITER shape control problem.

Humphreys, D.A.; Leuer, J.A.; Kellman, A.G. [General Atomics, San Diego, CA (United States); Haney, S.W.; Bulmer, R.H.; Pearlstein, L.D. [Lawrence Livermore National Lab., CA (United States); Portone, A. [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). ITER Joint Central Team

1994-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "involves iterative cycling" 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

Design and Overview of 100 kV Bushing for the DNB Injector of ITER  

Science Conference Proceedings (OSTI)

The 100 kV bushing is one of the most important and technologically challenging Safety Important Class (SIC) components of the Diagnostic Neutral Beam (DNB) injector of ITER. It forms interface between gas insulated electrical transmission line and torus primary vacuum and acts as a vacuum feedthrough of ITER. Design optimization has been carried out to meet the electric and structural requirements based on its classification. Unlike HNB bushing, single stage bushing is designed to provide 100 kV isolation. Finite Element Analysis (FEA) based optimization has been carried out for electrostatic and structural analysis. Manufacturing assembly sequence is studied and presented in this paper. However validation of the same is foreseen from manufacturer.

Shah, Sejal; Bandyopadhyay, M.; Rotti, C.; Singh, M. J.; Roopesh, G.; Chakraborty, A. K. [ITER-India, Institute for Plasma Research, Gandhinagar-382025, Gujarat (India); Rajesh, S. [ITER-India, Institute for Plasma Research, Gandhinagar-382025, Gujarat (India); Microelectronics and Materials Physics Labs, P.O.Box 4500, FIN-90014 University of Oulu (Finland); Nishad, S.; Srusti, B. [DesignTech Systems Ltd, Banjara Hills, Hyderabad, Andhra Pradesh-500034 (India); Schunke, B.; Hemsworth, R.; Chareyre, J.; Svensson, L. [ITER Organisation, Route de Vinon, CS 90 046, 13067 St. Paul lez Durance Cedex (France)

2011-09-26T23:59:59.000Z

382

Review of the International Thermonuclear Experimental Reactor (ITER) detailed design report  

SciTech Connect

Dr. Martha Krebs, Director, Office of Energy Research at the US Department of Energy (DOE), wrote to the Fusion Energy Sciences Advisory Committee (FESAC), in letters dated September 23 and November 6, 1996, requesting that FESAC review the International Thermonuclear Experimental Reactor (ITER) Detailed Design Report (DDR) and provide its view of the adequacy of the DDR as part of the basis for the United States decision to enter negotiations with the other interested Parties regarding the terms and conditions for an agreement for the construction, operations, exploitation and decommissioning of ITER. The letter from Dr. Krebs, referred to as the Charge Letter, provided context for the review and a set of questions of specific interest.

1997-04-18T23:59:59.000Z

383

BAKTRAK: Backtracking drifting objects using an iterative algorithm with a forward trajectory model  

E-Print Network (OSTI)

The task of determining the origin of a drifting object after it has been located is highly complex due to the uncertainties in drift properties and environmental forcing (wind, waves and surface currents). Usually the origin is inferred by running a trajectory model (stochastic or deterministic) in reverse. However, this approach has some severe drawbacks, most notably the fact that many drifting objects go through nonlinear state changes underway (e.g., evaporating oil or a capsizing lifeboat). This makes it difficult to naively construct a reverse-time trajectory model which realistically predicts the earliest possible time the object may have started drifting. We propose instead a different approach where the original (forward) trajectory model is kept unaltered while an iterative seeding and selection process allows us to retain only those particles that end up within a certain time-space radius of the observation. An iterative refinement process named BAKTRAK is employed where those trajectories that do...

Breivik, Řyvind; Ommundsen, Atle; Wettre, Cecilie

2011-01-01T23:59:59.000Z

384

In-Vessel Coil Material Failure Rate Estimates for ITER Design Use  

SciTech Connect

The ITER international project design teams are working to produce an engineering design for construction of this large tokamak fusion experiment. One of the design issues is ensuring proper control of the fusion plasma. In-vessel magnet coils may be needed for plasma control, especially the control of edge localized modes (ELMs) and plasma vertical stabilization (VS). These coils will be lifetime components that reside inside the ITER vacuum vessel behind the blanket modules. As such, their reliability is an important design issue since access will be time consuming if any type of repair were necessary. The following chapters give the research results and estimates of failure rates for the coil conductor and jacket materials to be used for the in-vessel coils. Copper and CuCrZr conductors, and stainless steel and Inconel jackets are examined.

L. C. Cadwallader

2013-01-01T23:59:59.000Z

385

Generation Maintenance Application Center: Combustion Turbine Combined-Cycle Heat Recovery Steam Generator Maintenance Guide  

Science Conference Proceedings (OSTI)

This guide provides information to assist personnel involved with the maintenance of the heat recovery steam generator at a combustion gas turbine combined cycle facility, including good maintenance practices, preventive maintenance techniques and troubleshooting guidance. BackgroundCombustion turbine combined cycle (CTCC) facilities utilize various components that can be unique to this particular type of power plant. As such, owners and ...

2013-05-15T23:59:59.000Z

386

Geothermal heat cycle research supercritical cycle with counterflow condenser in different orientations  

DOE Green Energy (OSTI)

The Heat Cycle Research Program, which is conducted for the Department of Energy, has as its objective the development of the technology for effecting the improved utilization of moderate temperature geothermal resources. The current testing involves the investigation of binary power cycle performance utilizing mixtures of non-adjacent hydrocarbons as the working fluids, with supercritical vaporization and in-tube condensation of the working fluid. The utilization of these concepts verified here will improve the net geofluid effectiveness (net watt hours plant output per pound of geofluid) about 20% over that of a conventional binary power plant. The major effect in this improvement is the ability to achieve integral, countercurrent condensation. Results are presented for the recent testing including those tests examining the performance of the countercurrent condenser at different tube inclinations and comparison with new design-base computer programs. 9 refs., 9 figs.

Bliem, C.J.; Mines, G.L.

1988-01-01T23:59:59.000Z

387

Arbitrary accuracy iterative phase estimation algorithm as a two qubit benchmark  

E-Print Network (OSTI)

We discuss the implementation of an iterative quantum phase estimation algorithm, with a single ancillary qubit. We suggest using this algorithm as a benchmark for multi-qubit implementations. Furthermore we describe in detail the smallest possible realization, using only two qubits, and exemplify with a superconducting circuit. We discuss the robustness of the algorithm in the presence of gate errors, and show that 7 bits of precision is obtainable, even with very limited gate accuracies.

M. Dobsicek; G. Johansson; V. S. Shumeiko; G. Wendin

2006-10-25T23:59:59.000Z

388

Atomic data for the ITER Core Imaging X-ray Spectrometer  

SciTech Connect

The parameters of the ITER core plasmas will be measured using the Core Imaging X-ray Spectrometer (CIXS), a high-resolution crystal spectrometer focusing on the L-shell spectra of highly ionized tungsten atoms. In order to correctly infer the plasma properties accurate atomic data are required. Here, some aspects of the underlying physics are discussed using experimental data and theoretical predictions from modeling.

Clementson, J; Beiersdorfer, P; Biedermann, C; Bitter, M; Delgado-Aparicio, L F; Graf, A; Gu, M F; Hill, K W; Barnsley, R

2012-06-15T23:59:59.000Z

389

Global convergence of diluted iterations in maximum-likelihood quantum tomography  

E-Print Network (OSTI)

In this paper we present an inexact stepsize selection for the Diluted R\\rho R algorithm, used to obtain the maximum likelihood estimate to the density matrix in quantum state tomography. We give a new interpretation for the diluted R\\rho R iterations that allows us to prove the global convergence under weaker assumptions. Thus, we propose a new algorithm which is globally convergent and suitable for practical implementation.

D. S. Gonçalves; M. A. Gomes-Ruggiero; C. Lavor

2013-06-13T23:59:59.000Z

390

Development of a YAG laser system for the edge Thomson scattering system in ITER  

SciTech Connect

A prototype YAG laser system for the edge Thomson scattering system in ITER has been newly developed. Performance of the laser amplifier was improved by using flow tubes made of samarium-doped glass; the small signal gain reached 20 at its maximum. As a result, an output energy of 7.66 J at 100 Hz was successfully achieved, and the performance exceeded the target performance (5 J, 100 Hz).

Hatae, T.; Yatsuka, E.; Hayashi, T.; Ono, T.; Kusama, Y. [Fusion Research and Development Directorate, Japan Atomic Energy Agency, Ibaraki 311-0193 (Japan); Yoshida, H. [Institute of Laser Engineering, Osaka University, Osaka 565-0871 (Japan)

2012-10-15T23:59:59.000Z

391

Iterative conformal mapping approach to diffusion-limited aggregation with surface tension effect  

E-Print Network (OSTI)

We present a simple method for incorporating the surface tension effect into an iterative conformal mapping model of two-dimensional diffusion-limited aggregation. A curvature-dependent growth probability is introduced and the curvature is given by utilizing the branch points of a conformal map. The resulting cluster exhibits a crossover from compact to fractal growth. In the fractal growth regime, it is confirmed, by the conformal map technique, that the fractal dimension of its area and perimeter length coincide.

Hiroshi Miki; Haruo Honjo

2013-03-04T23:59:59.000Z

392

An iterative method for single and vertically stacked semiconductor quantum dots simulation  

Science Conference Proceedings (OSTI)

We present in this paper a computational effective nonlinear iterative method for calculating the electron energy spectra in single and vertically stacked InAs/GaAs semiconductor quantum dots. The physical model problem is formulated with the effective ... Keywords: Coupling effect, Electronic structure, Energy spectra, Modelling and simulation, Multishift QR method, Nonlinear eigenvalue problem, Semiconductor nanostructure, Single quantum dot, Vertically stacked quantum dot, Wave function

Yiming Li

2005-10-01T23:59:59.000Z

393

A spatial multigrid iterative method for two-dimensional discrete-ordinates transport problems  

E-Print Network (OSTI)

Iterative solutions of the Boltzmann transport equation are computationally intensive. Spatial multigrid methods have led to efficient iterative algorithms for solving a variety of partial differential equations; thus, it is natural to explore their application to transport equations. Manteuffel et al. conducted such an exploration in one spatial dimension, using two-cell inversions as the relaxation or smoothing operation, and reported excellent results. In this dissertation we extensively test Manteuffel??s one-dimensional method and our modified versions thereof. We demonstrate that the performance of such spatial multigrid methods can degrade significantly given strong heterogeneities. We also extend Manteuffel??s basic approach to two-dimensional problems, employing four-cell inversions for the relaxation operation. We find that for uniform homogeneous problems the two-dimensional multigrid method is not as rapidly convergent as the one-dimensional method. For strongly heterogeneous problems the performance of the two-dimensional method is much like that of the one-dimensional method, which means it can be slow to converge. We conclude that this approach to spatial multigrid produces a method that converges rapidly for many problems but not for others. That is, this spatial multigrid method is not unconditionally rapidly convergent. However, our analysis of the distribution of eigenvalues of the iteration operators indicates that this spatial multigrid method may work very well as a preconditioner within a Krylov iteration algorithm, because its eigenvalues tend to be relatively well clustered. Further exploration of this promising result appears to be a fruitful area of further research.

Lansrud, Brian David

2005-05-01T23:59:59.000Z

394

Control of non-controllable quantum systems: A quantum control algorithm based on Grover iteration  

E-Print Network (OSTI)

A new notion of controllability, eigenstate controllability, is defined for finite-dimensional bilinear quantum mechanical systems which are neither strongly completely controllably nor completely controllable. And a quantum control algorithm based on Grover iteration is designed to perform a quantum control task of steering a system, which is eigenstate controllable but may not be (strongly) completely controllable, from an arbitrary state to a target state.

Chen-Bin Zhang; Dao-Yi Dong; Zong-Hai Chen

2005-03-02T23:59:59.000Z

395

Absolutely and uniformly convergent iterative approach to inverse scattering with an infinite radius of convergence  

DOE Patents (OSTI)

A method and system for solving the inverse acoustic scattering problem using an iterative approach with consideration of half-off-shell transition matrix elements (near-field) information, where the Volterra inverse series correctly predicts the first two moments of the interaction, while the Fredholm inverse series is correct only for the first moment and that the Volterra approach provides a method for exactly obtaining interactions which can be written as a sum of delta functions.

Kouri, Donald J. (Houston, TX); Vijay, Amrendra (Houston, TX); Zhang, Haiyan (Houston, TX); Zhang, Jingfeng (Houston, TX); Hoffman, David K. (Ames, IA)

2007-05-01T23:59:59.000Z

396

Limit Cycle and Conserved Dynamics  

E-Print Network (OSTI)

We demonstrate that a potential coexists with limit cycle. Here the potential determines the final distribution of population. Our demonstration consists of three steps: We first show the existence of limit from a typical physical sciences setting: the potential is a type of Mexican hat type, with the strength of a magnetic field scale with the strength the potential gradient near the limit cycle, and the friction goes to zero faster than the potential near the limit cycle. Hence the dynamics at the limit cycle is conserved. The diffusion matrix is nevertheless finite at the limit cycle. Secondly, we construct the potential in the dynamics with limit cycle in a typical dynamical systems setting. Thirdly, we argue that such a construction can be carried out in a more general situation based on a method discovered by one of us. This method of dealing with stochastic differential equation is in general different from both Ito and Stratonovich calculus. Our result may be useful in many related applications, such as in the discussion of metastability of limit cycle and in the construction of Hopfield potential in the neural network computation.

X. -M. Zhu; L. Yin; P. Ao

2004-12-21T23:59:59.000Z

397

Photonic circuits for iterative decoding of a class of low-density parity-check codes  

E-Print Network (OSTI)

Photonic circuits in which stateful components are coupled via guided electromagnetic fields are natural candidates for native implementation of iterative stochastic algorithms based on propagation of information around a graph. Conversely, such message passing algorithms suggest novel circuit architectures for signal processing and computation that are well matched to nanophotonic device physics. Here we construct and analyze a quantum optical model of a photonic circuit for iterative decoding of a class of low-density parity-check (LDPC) codes called expander codes. Our circuit can be understood as an open quantum system whose autonomous dynamics map straightforwardly onto the subroutines of an LDPC decoding scheme, with several attractive features: it can operate in the ultra-low power regime of photonics in which quantum fluctuations become significant, is robust to noise and component imperfections, achieves comparable performance to known iterative algorithms for this class of codes, and provides an instructive example of how nanophotonic cavity quantum electrodynamic components can enable useful new information technology even if the solid-state qubits on which they are based are heavily dephased and cannot support large-scale entanglement.

Dmitri S. Pavlichin; Hideo Mabuchi

2013-06-03T23:59:59.000Z

398

Lessons learnt from ITER safety & licensing for DEMO and future nuclear fusion facilities  

E-Print Network (OSTI)

One of the strong motivations for pursuing the development of fusion energy is its potentially low environmental impact and very good safety performance. But this safety and environmental potential can only be fully realized by careful design choices. For DEMO and other fusion facilities that will require nuclear licensing, S&E objectives and criteria should be set at an early stage and taken into account when choosing basic design options and throughout the design process. Studies in recent decades of the safety of fusion power plant concepts give a useful basis on which to build the S&E approach and to assess the impact of design choices. The experience of licensing ITER is of particular value, even though there are some important differences between ITER and DEMO. The ITER project has developed a safety case, produced a preliminary safety report and had it examined by the French nuclear safety authorities, leading to the licence to construct the facility. The key technical issues that arose during ...

Taylor, Neill

2013-01-01T23:59:59.000Z

399

High power millimeter wave experiment of ITER relevant electron cyclotron heating and current drive system  

Science Conference Proceedings (OSTI)

High power, long pulse millimeter (mm) wave experiments of the RF test stand (RFTS) of Japan Atomic Energy Agency (JAEA) were performed. The system consists of a 1 MW/170 GHz gyrotron, a long and short distance transmission line (TL), and an equatorial launcher (EL) mock-up. The RFTS has an ITER-relevant configuration, i.e., consisted by a 1 MW-170 GHz gyrotron, a mm wave TL, and an EL mock-up. The TL is composed of a matching optics unit, evacuated circular corrugated waveguides, 6-miter bends, an in-line waveguide switch, and an isolation valve. The EL-mock-up is fabricated according to the current design of the ITER launcher. The Gaussian-like beam radiation with the steering capability of 20 deg. - 40 deg. from the EL mock-up was also successfully proved. The high power, long pulse power transmission test was conducted with the metallic load replaced by the EL mock-up, and the transmission of 1 MW/800 s and 0.5 MW/1000 s was successfully demonstrated with no arcing and no damages. The transmission efficiency of the TL was 96%. The results prove the feasibility of the ITER electron cyclotron heating and current drive system.

Takahashi, K.; Kajiwara, K.; Oda, Y.; Kasugai, A.; Kobayashi, N.; Sakamoto, K. [Japan Atomic Energy Agency, 801-1 Mukoyama, Naka, Ibaraki 311-0193 (Japan); Doane, J.; Olstad, R. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); Henderson, M. [ITER Organization, CS90 046, 13067 St. Paul lez Durance Cedex (France)

2011-06-15T23:59:59.000Z

400

Uncertainty assessment and analysis of ITER in-VV tritium inventory determination  

Science Conference Proceedings (OSTI)

Tracking of tritium inventories on ITER will be essential to ensure that the safety limits established for the mobilizable tritium inventory in the vacuum vessel are not violated. Tritium will be delivered to the ITER site from outside suppliers. Staring with the tritium imports the value of tritium inventory at ITER site will be known with a certain error that will propagate in time. During plasma operation, shot by shot measurements of the tritium delivered to the Torus and recovered will allow the amount of tritium trapped in the Torus to be computed at the end of the day. A case study for different measuring techniques and several measuring points for the tritium recovered from Torus have been done. An alternative method is to measure overnight the variation in the inventory of the storage and delivery system and the associated error when this method will be employed are presented. In order to reduce the errors on the tritium trapped in-vessel, at certain time intervals a method of global tritium inventory will be performed. The method envisages the transfer of all the mobilizable tritium from the plant and measurement of this inventory in the self-assay beds from the storage and delivery system. Evaluation of the most important sources of error for the tritium trapped in-vessel and means of minimization are eventually presented. (authors)

Cristescu, I. R.; Cristescu, I.; Glugla, M. [FzK, Tritium Laboratory, POBox 3640, 76021 Karlsruhe (Germany); Murdoch, D. [EFDA CSU, MPI fuer Plasmaphysik, Garching (Germany); Ciattaglia, S. [ITER IT, CEA Cadarache, 13108 St. Paul-lez-Durance (France)

2008-07-15T23:59:59.000Z

Note: This page contains sample records for the topic "involves iterative cycling" 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

RMP ELM Suppression in DIII-D Plasmas with ITER Similar Shapes and Collisionalities  

SciTech Connect

Large Type-I edge localized modes (ELMs) are completely eliminated with small n = 3 resonant magnetic perturbations (RMP) in low average triangularity, = 0.26, plasmas and in ITER similar shaped (ISS) plasmas, = 0.53, with ITER relevant collisionalities ve 0.2. Significant differences in the RMP requirements and in the properties of the ELM suppressed plasmas are found when comparing the two triangularities. In ISS plasmas, the current required to suppress ELMs is approximately 25% higher than in low average triangularity plasmas. It is also found that the width of the resonant q95 window required for ELM suppression is smaller in ISS plasmas than in low average triangularity plasmas. An analysis of the positions and widths of resonant magnetic islands across the pedestal region, in the absence of resonant field screening or a self-consistent plasma response, indicates that differences in the shape of the q profile may explain the need for higher RMP coil currents during ELM suppression in ISS plasmas. Changes in the pedestal profiles are compared for each plasma shape as well as with changes in the injected neutral beam power and the RMP amplitude. Implications of these results are discussed in terms of requirements for optimal ELM control coil designs and for establishing the physics basis needed in order to scale this approach to future burning plasma devices such as ITER.

Evans, T.E. [General Atomics, San Diego; Fenstermacher, M. E. [Lawrence Livermore National Laboratory (LLNL); Moyer, R.A. [University of California, San Diego; Osborne, T. H. [General Atomics; Watkins, J. G. [Sandia National Laboratories (SNL); Gohil, P. [General Atomics; Joseph, I. [University of California, San Diego; Schaffer, M. J. [General Atomics, San Diego; Baylor, Larry R [ORNL; Becoulet, M. [CEA Cadarache, St. Paul lex Durance, France; Boedo, J.A. [University of California, San Diego; Burrell, K. H. [General Atomics; DeGrassie, J. S. [General Atomics, San Diego; Finken, K. H. [Max-Planck-Institute for Plasmaphysik, EURATOM-Association, Greifswald, Germany; Jernigan, Thomas C [ORNL; Jakubowski, M. W. [Max-Planck-Institute for Plasmaphysik, EURATOM-Association, Greifswald, Germany; Lasnier, C. J. [Lawrence Livermore National Laboratory (LLNL); Lehnen, M. [Forschungszentrum Julich, Julich, Germany; Leonard, A. W. [General Atomics; Lonnroth, J. [Association Euratom-Tekes, Finland; Nardon, E. [CEA Cadarache, St. Paul lex Durance, France; Parail, V. [EURATOM / UKAEA, UK; Schmitz, O. [Forschungszentrum Julich, Julich, Germany; Unterberg, B. [Max-Planck-Institute for Plasmaphysik, EURATOM-Association, Greifswald, Germany; West, W.P. [General Atomics, San Diego

2008-01-01T23:59:59.000Z

402

Identifying 802.11 traffic from passive measurements using iterative Bayesian inference  

E-Print Network (OSTI)

Abstract—In this paper, we propose a classification scheme that differentiates Ethernet and WLAN TCP flows based on measurements collected passively at the edge of a network. This scheme computes two quantities, the fraction of wireless TCP flows and the degree of belief that a TCP flow traverses a WLAN inside the network, using an iterative Bayesian inference algorithm that we developed. We prove that this iterative Bayesian inference algorithm converges to the unique maximum likelihood estimate (MLE) of these two quantities. Furthermore, it has the advantage that it can handle any general-classification problem given the marginal distributions of these classes. Numerical and experimental evaluations demonstrate that our classification scheme obtains accurate results. We apply this scheme to two sets of traces collected from two campus networks: one set collected from UMass in mid 2005 and the other collected from UConn in late 2010. Our technique infers that 4%–7 % and 52%–55 % of incoming TCP flows traverse an IEEE 802.11 wireless link in these two networks, respectively. Index Terms—IEEE 802.11 wireless LAN, iterative Bayesian inference, TCP ACK-pairs, wireless traffic detection.

Wei Wei; Sharad Jaiswal; Jim Kurose; Don Towsley; Kyoungwon Suh; Bing Wang

2006-01-01T23:59:59.000Z

403

Neutron spectroscopy as a fuel ion ratio diagnostic: Lessons from JET and prospects for ITER  

SciTech Connect

The determination of the fuel ion ratio n{sub t}/n{sub d} in ITER is required at a precision of 20%, time resolution of 100 ms, spatial resolution of a/10, and over a range of 0.01ITER to assess the possibility to use neutron emission spectroscopy (NES) for such measurements. We show that NES meets the requirements for ion temperatures T{sub i}>6 keV and for n{sub T}/n{sub D}<0.6. A crucial issue is the signal-to-background situation in the measurement of the weak 2.5 MeV emission from DD reactions in the presence of a background of scattered 14 MeV DT neutrons. Important experimental input and corroboration for this assessment are presented from the time-of-flight neutron spectrometer at JET where the presence of a strong component of backscattered neutrons is observed. Neutron emission components on ITER due to beam-thermal and tritium-tritium reactions can further enhance the prospects for NES.

Ericsson, G.; Conroy, S.; Gatu Johnson, M.; Andersson Sunden, E.; Cecconello, M.; Eriksson, J.; Hellesen, C.; Sangaroon, S.; Weiszflog, M. [Department of Physics and Astronomy, Uppsala University (EURATOM-VR Association), SE-75120 Uppsala (Sweden); Collaboration: JET EFDA Contributors

2010-10-15T23:59:59.000Z

404

A fast iterative model for discrete velocity calculations on triangular grids  

SciTech Connect

A fast synthetic type iterative model is proposed to speed up the slow convergence of discrete velocity algorithms for solving linear kinetic equations on triangular lattices. The efficiency of the scheme is verified both theoretically by a discrete Fourier stability analysis and computationally by solving a rarefied gas flow problem. The stability analysis of the discrete kinetic equations yields the spectral radius of the typical and the proposed iterative algorithms and reveal the drastically improved performance of the latter one for any grid resolution. This is the first time that stability analysis of the full discrete kinetic equations related to rarefied gas theory is formulated, providing the detailed dependency of the iteration scheme on the discretization parameters in the phase space. The corresponding characteristics of the model deduced by solving numerically the rarefied gas flow through a duct with triangular cross section are in complete agreement with the theoretical findings. The proposed approach may open a way for fast computation of rarefied gas flows on complex geometries in the whole range of gas rarefaction including the hydrodynamic regime.

Szalmas, Lajos [Department of Mechanical Engineering, University of Thessaly, Pedion Areos, Volos 38334 (Greece); Valougeorgis, Dimitris [Department of Mechanical Engineering, University of Thessaly, Pedion Areos, Volos 38334 (Greece)], E-mail: diva@mie.uth.gr

2010-06-01T23:59:59.000Z

405

Hydrogen lines in the infrared region and spectral background for the thomson scattering diagnostics of the iter divertor plasma  

Science Conference Proceedings (OSTI)

Calculations are made of the plasma spectral background, which is important for the Thomson scattering diagnostics in the ITER divertor. Theoretical grounds have been elaborated for computing the hydrogen spectral line shapes in the infrared spectral region for a divertor plasma in ITER. The shape of the P-7 Paschen line (transition n = 7 {yields} n = 3) located near the laser scattering signal has been calculated for various lines of sight in the ITER divertor. Contributions from different mechanisms of broadening the P-7 line have been examined. The spectral intensities of bremsstrahlung and photorecombination continuum have been calculated. All calculations use data on the spatial distribution of temperatures and densities of all species of plasma particles computed with the SOLPS4.3 code for basic operation regimes of the ITER divertor.

Lisitsa, V. S. [National Research Center Kurchatov Institute, Tokamak Physics Institute (Russian Federation); Mukhin, E. E. [Russian Academy of Sciences, Ioffe Physical Technical Institute (Russian Federation); Kadomtsev, M. B.; Kukushkin, A. B. [National Research Center Kurchatov Institute, Tokamak Physics Institute (Russian Federation); Kukushkin, A. S. [ITER Organization, Cadarache (France); Kurskiev, G. S. [Russian Academy of Sciences, Ioffe Physical Technical Institute (Russian Federation); Levashova, M. G. [National Research Center Kurchatov Institute, Tokamak Physics Institute (Russian Federation); Tolstyakov, S. Yu. [Russian Academy of Sciences, Ioffe Physical Technical Institute (Russian Federation)

2012-02-15T23:59:59.000Z

406

Report of a technical evaluation panel on the use of beryllium for ITER plasma facing material and blanket breeder material  

SciTech Connect

Beryllium because of its low atomic number and high thermal conductivity, is a candidate for both ITER first wall and divertor surfaces. This study addresses the following: why beryllium; design requirements for the ITER divertor; beryllium supply and unirradiated physical/mechanical property database; effects of irradiation on beryllium properties; tritium issues; beryllium health and safety; beryllium-coolant interactions and safety; thermal and mechanical tests; plasma erosion of beryllium; recommended beryllium grades for ITER plasma facing components; proposed manufacturing methods to produce beryllium parts for ITER; emerging beryllium materials; proposed inspection and maintenance techniques for beryllium components and coatings; time table and costs; and the importance of integrating materials and manufacturing personnel with designers.

Ulrickson, M.A. [ed.] [Sandia National Labs., Albuquerque, NM (United States); Manly, W.D. [Oak Ridge National Lab., TN (United States); Dombrowski, D.E. [Brush Wellman, Inc., Cleveland, OH (United States)] [and others

1995-08-01T23:59:59.000Z

407

On Forward-in-Time Differencing for Fluids: Stopping Criteria for Iterative Solutions of Anelastic Pressure Equations  

Science Conference Proceedings (OSTI)

In this note, the authors address the practical issue of selecting appropriate stopping criteria for iterative solutions to the elliptic pressure equation arising in nonoscillatory, forward-in-time Eulerian and semi-Lagrangian anelastic fluid ...

Piotr K. Smolarkiewicz; Vanda Grubis?i?; Len G. Margolin

1997-04-01T23:59:59.000Z

408

The impact of parallel programming models on the performance of iterative linear solvers for finite element applications  

Science Conference Proceedings (OSTI)

Parallel iterative linear solvers for unstructured grids in FEM applications, originally developed for the Earth Simulator (ES), are ported to various types of parallel computer. The performance of flat MPI and hybrid parallel programming models is compared ...

Kengo Nakajima

2006-06-01T23:59:59.000Z

409

An $O(\\sqrt{n}\\log \\frac{(x^0)^Ts^0}{\\epsilon})$ iteration primal-dual ...  

E-Print Network (OSTI)

An $O(\\sqrt{n}\\log \\frac{(x^0)^Ts^0}{\\epsilon})$ iteration primal-dual path- following method, based on wide neighborhoods and large updates, for monotone ...

410

Analysis of Spontaneous Mass Generation by Iterative Method in the Nambu-Jona-Lasinio Model and Gauge Theories  

E-Print Network (OSTI)

We propose a new iterative method to directly calculate the spontaneous mass generation due to the dynamical chiral symmetry breaking. We can conclude the physical mass definitely without recourse to any other consideration like the free energy comparison.

Ken-Ichi Aoki; Shinnosuke Onai; Daisuke Sato

2013-04-10T23:59:59.000Z

411

An Iterative Solver with a Convergence-Acceleration Technique for Pressure Field in an Uneven-Spacing Grid System  

Science Conference Proceedings (OSTI)

A straightforward iterative method is developed for solving the pressure field in three-dimensional, anelastic, nonhydrostatic, mesoscale models with uneven-spacing grid systems for which direct FFT (fan Fourier transform) schemes cannot be ...

Chih-Yue Jim Kao; Lawrence H. Auer

1990-07-01T23:59:59.000Z

412

Supercritical carbon dioxide cycle control analysis.  

SciTech Connect

This report documents work carried out during FY 2008 on further investigation of control strategies for supercritical carbon dioxide (S-CO{sub 2}) Brayton cycle energy converters. The main focus of the present work has been on investigation of the S-CO{sub 2} cycle control and behavior under conditions not covered by previous work. An important scenario which has not been previously calculated involves cycle operation for a Sodium-Cooled Fast Reactor (SFR) following a reactor scram event and the transition to the primary coolant natural circulation and decay heat removal. The Argonne National Laboratory (ANL) Plant Dynamics Code has been applied to investigate the dynamic behavior of the 96 MWe (250 MWt) Advanced Burner Test Reactor (ABTR) S-CO{sub 2} Brayton cycle following scram. The timescale for the primary sodium flowrate to coast down and the transition to natural circulation to occur was calculated with the SAS4A/SASSYS-1 computer code and found to be about 400 seconds. It is assumed that after this time, decay heat is removed by the normal ABTR shutdown heat removal system incorporating a dedicated shutdown heat removal S-CO{sub 2} pump and cooler. The ANL Plant Dynamics Code configured for the Small Secure Transportable Autonomous Reactor (SSTAR) Lead-Cooled Fast Reactor (LFR) was utilized to model the S-CO{sub 2} Brayton cycle with a decaying liquid metal coolant flow to the Pb-to-CO{sub 2} heat exchangers and temperatures reflecting the decaying core power and heat removal by the cycle. The results obtained in this manner are approximate but indicative of the cycle transient performance. The ANL Plant Dynamics Code calculations show that the S-CO{sub 2} cycle can operate for about 400 seconds following the reactor scram driven by the thermal energy stored in the reactor structures and coolant such that heat removal from the reactor exceeds the decay heat generation. Based on the results, requirements for the shutdown heat removal system may be defined. In particular, the peak heat removal capacity of the shutdown heat removal loop may be specified to be 1.1 % of the nominal reactor power. An investigation of the oscillating cycle behavior calculated by the ANL Plant Dynamics Code under specific conditions has been carried out. It has been found that the calculation of unstable operation of the cycle during power reduction to 0 % may be attributed to the modeling of main compressor operation. The most probable reason for such instabilities is the limit of applicability of the currently used one-dimensional compressor performance subroutines which are based on empirical loss coefficients. A development of more detailed compressor design and performance models is required and is recommended for future work in order to better investigate and possibly eliminate the calculated instabilities. Also, as part of such model development, more reliable surge criteria should be developed for compressor operation close to the critical point. It is expected that more detailed compressor models will be developed as a part of validation of the Plant Dynamics Code through model comparison with the experiment data generated in the small S-CO{sub 2} loops being constructed at Barber-Nichols Inc. and Sandia National Laboratories (SNL). Although such a comparison activity had been planned to be initiated in FY 2008, data from the SNL compression loop currently in operation at Barber Nichols Inc. has not yet become available by the due date of this report. To enable the transient S-CO{sub 2} cycle investigations to be carried out, the ANL Plant Dynamics Code for the S-CO{sub 2} Brayton cycle was further developed and improved. The improvements include further optimization and tuning of the control mechanisms as well as an adaptation of the code for reactor systems other than the Lead-Cooled Fast Reactor (LFR). Since the focus of the ANL work on S-CO{sub 2} cycle development for the majority of the current year has been on the applicability of the cycle to SFRs, work has started on modification of the ANL Plant Dynamics Code to allow

Moisseytsev, A.; Sienicki, J. J. (Nuclear Engineering Division)

2011-04-11T23:59:59.000Z

413

Minimize Boiler Short Cycling Losses  

SciTech Connect

This revised ITP tip sheet on minimizing boiler short cycling losses provides how-to advice for improving industrial steam systems using low-cost, proven practices and technologies.

2006-01-01T23:59:59.000Z

414

Alternative Cycles for Power Converters  

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

expansion in the high pressure turbine by passing it through an additional lead-to-steam heat exchanger (HX). This can be a complication relative to the superheated steam cycle....

415

Deoxygenation in Cycling Fossil Plants  

Science Conference Proceedings (OSTI)

Minimizing shutdown oxygen levels at a cycling fossil plant can reduce corrosion product transport to the boilers. In this study two forms of activated carbon were used to catalyze the oxygen/hydrazine reaction and minimize oxygen levels.

1992-05-01T23:59:59.000Z

416

Ammonium generation during SRAT cycle  

DOE Green Energy (OSTI)

During the IDMS noble-metal demonstration runs ammonium nitrate deposition was found in the vessel vent system of the feed preparation area. In the bench-scale experiments of studying the hydrogen generation during the sludge treatment cycle, ammonium ion production was also monitored. It was found that: During a simulation of the DWPF Cold Chemical Runs SRAT cycle no detectable amount of ammonium ions was generated when treating a non-noble-metal containing sludge simulant according to the nitric acid flowsheet. Ammonium ions were generated during the SRAT-SME cycle when treating the noble-metal containing sludge with either formic acid or nitric acid/late-washing PHA. This is due to the reaction between formic acid and nitrate catalyzed by the noble metals in the sludge simulant. Ammonium ion production closely followed the hydrogen evolution from the catalytic decomposition of formic acid. This report summarizes the results of the production of ammonia during the SRAT cycle.

Hsu, C.W.

1992-10-13T23:59:59.000Z

417

American business cycles and innovation  

E-Print Network (OSTI)

Economists have long studied innovation and its effects on business cycles. Economist Joseph Alois Schumpeter (1883-1950) was the first economist to thoroughly discuss these ideas in his Theorie der wirtschaftlichen Entwicklung, published in 1911 (English translation: The Theory of Economic Development, 1934). This paper focuses on three issues: defining innovation, defining and identifying business cycles, and determining which innovations caused which business cycles. The first section introduces the concepts of innovation and invention. The second section discusses the business cycles and highlights general causes of business cycles. The final section details the history of the iron, steel, aluminum, and pharmaceutical industries and incorporates the available business and economic data (output, productivity, inventories, and capital investment) required to answer the central question: which innovations caused which business cycles? The iron industry, examined over the sixteenth and seventeenth centuries, reveals that its relationship to the business cycle is likely significant but was difficult to quantify because of limited data. An examination of the steel industry from the post-Civil War period to the early twentieth century follows. The steel industry had a significant effect on the business cycle and seemed to direct the business cycle during the growth in railroad mileage. Steel was a huge and indispensable industry for most of the 20[th] century so it makes a very important case to study. The aluminum industry is relevant to examine because the process for making aluminum has remained the same since the American inventor, Charles Hall, patented his method in 1889. The contribution of aluminum was significant because of the introduction of the large-scale electrical generators needed to produce aluminum. Finally, the paper focuses on the contribution of the pharmaceutical industry to the business cycle. The pharmaceutical industry is important to this study because it has already proved to be a major source of innovation and is an industry that will continue to play a significant role in the American economy. The findings reveal the contribution from this industry was most significant in the post-World War II era of research and development. The paper concludes with suggestions for improving and expanding this innovation and business cycle study.

Hood, Michael

2004-01-01T23:59:59.000Z

418

Life Cycle Inventory of a CMOS Chip  

E-Print Network (OSTI)

Reichl, H. “Life cycle inventory analysis and identificationAllen, D.T. ; “Life cycle inventory development for waferLife Cycle Inventory of a CMOS Chip Sarah Boyd and David

Boyd, Sarah; Dornfeld, David; Krishnan, Nikhil

2006-01-01T23:59:59.000Z

419

The DOE Water Cycle Pilot Study  

E-Print Network (OSTI)

The DOE Water Cycle Pilot Study N.L. Miller 1 *, A.W. KingCycle Research Strategy, DOE SC-0043, Office of BiologicalLBNL Report LBNL-53826. The DOE Water Cycle Pilot Study is

2003-01-01T23:59:59.000Z

420

Application of chemical kinetics to mercury cycling in the aquatic environment: Photoreduction of mercury(II) and binding of mercury(II) and methylmercury(+) to natural ligands .  

E-Print Network (OSTI)

??The thesis comprises four main chapters on chemical reactions and kinetics of some of the processes involved in the global mercury cycle. In the first… (more)

Ababneh, Fuad A

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "involves iterative cycling" 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

Photovoltaics: Life-cycle Analyses  

DOE Green Energy (OSTI)

Life-cycle analysis is an invaluable tool for investigating the environmental profile of a product or technology from cradle to grave. Such life-cycle analyses of energy technologies are essential, especially as material and energy flows are often interwoven, and divergent emissions into the environment may occur at different life-cycle-stages. This approach is well exemplified by our description of material and energy flows in four commercial PV technologies, i.e., mono-crystalline silicon, multi-crystalline silicon, ribbon-silicon, and cadmium telluride. The same life-cycle approach is applied to the balance of system that supports flat, fixed PV modules during operation. We also discuss the life-cycle environmental metrics for a concentration PV system with a tracker and lenses to capture more sunlight per cell area than the flat, fixed system but requires large auxiliary components. Select life-cycle risk indicators for PV, i.e., fatalities, injures, and maximum consequences are evaluated in a comparative context with other electricity-generation pathways.

Fthenakis V. M.; Kim, H.C.

2009-10-02T23:59:59.000Z

422

Appendix V Public Involvement Plan  

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

V V Public Involvement Plan Revision No.: 6 February 2008 Federal Facility Agreement and Consent Order (FFACO) FFACO, Appendix V February 2008 i FFACO Public Involvement Plan U.S. Department of Energy National Nuclear Security Administration Nevada Site Office Las Vegas, Nevada U.S. Department of Defense Defense Threat Reduction Agency Detachment 1, Nevada Operations Mercury, Nevada U.S. Department of Energy Office of Legacy Management Grand Junction, Colorado FFACO, Appendix V February 2008 ii Preface The Public Involvement Plan serves two purposes: it provides a broad public involvement strategy, and fulfills requirements contained in the Federal Facility Agreement and Consent Order (FFACO) relating to public awareness and participation. Under the FFACO, agreed to by

423

Public Involvment Plan - Rifle, Colorado  

Office of Legacy Management (LM)

4-TAR 4-TAR MAC-GWRIF 7.1 UMTRA Ground Water Project Public Involvement Plan for the Environmental Assessment of Ground Water Compliance at the New and Old Rifle, Colorado, Uranium Mill Tailings Sites May 1999 Prepared by U.S. Department of Energy Grand Junction Office Grand Junction, Colorado Work performed under DOE Contract No. DE-AC13-96GJ87335 Public Involvement Plan for the Rifle UMTRA Sites Page 2 Introduction This Public Involvement Plan is tiered to the Uranium Mill Tailings Remedial Action (UMTRA) Ground Water Project Public Participation Plan dated October 1997. This Public Involvement Plan applies to both the Old and New Rifle, Colorado, UMTRA Project sites and details the activities that have been or will be carried out to meet the public participation requirements of the

424

NETL Life Cycle Analysis Fact Sheets  

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

Life Cycle Analysis Fact Sheets Life Cycle Analysis Role of Alternative Energy Sources - Wind Technology Assessment PDF-372KB (Sept 2012) Role of Alternative Energy Sources -...

425

Building Technologies Office: Life Cycle Inventory Database  

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

Life Cycle Inventory Database to someone by E-mail Share Building Technologies Office: Life Cycle Inventory Database on Facebook Tweet about Building Technologies Office: Life...

426

Equilibrium cycle pin by pin transport depletion calculations with DeCART  

SciTech Connect

As the Advanced Fuel Cycle Initiative (AFCI) program has matured it has become more important to utilize more advanced simulation methods. The work reported here was performed as part of the AFCI fellowship program to develop and demonstrate the capability of performing high fidelity equilibrium cycle calculations. As part of the work here, a new multi-cycle analysis capability was implemented in the DeCART code which included modifying the depletion modules to perform nuclide decay calculations, implementing an assembly shuffling pattern description, and modifying iteration schemes. During the work, stability issues were uncovered with respect to converging simultaneously the neutron flux, isotopics, and fluid density and temperature distributions in 3-D. Relaxation factors were implemented which considerably improved the stability of the convergence. To demonstrate the capability two core designs were utilized, a reference UOX core and a CORAIL core. Full core equilibrium cycle calculations were performed on both cores and the discharge isotopics were compared. From this comparison it was noted that the improved modeling capability was not drastically different in its prediction of the discharge isotopics when compared to 2-D single assembly or 2-D core models. For fissile isotopes such as U-235, Pu-239, and Pu-241 the relative differences were 1.91%, 1.88%, and 0.59%), respectively. While this difference may not seem large it translates to mass differences on the order of tens of grams per assembly, which may be significant for the purposes of accounting of special nuclear material. (authors)

Kochunas, B.; Downar, T. [Dept. of Nuclear Engineering and Radiological Sciences, Univ. of Michigan, 2200 Bonisteel Blvd, Ann Arbor, MI 48109 (United States); Taiwo, T. [Argonne National Laboratory, 9700 S. Cass Ave, Argonne, IL 60439 (United States)

2012-07-01T23:59:59.000Z

427

Evaluation and Optimization of a Supercritical Carbon Dioxide Power Conversion Cycle for Nuclear Applications  

Science Conference Proceedings (OSTI)

There have been a number of studies involving the use of gases operating in the supercritical mode for power production and process heat applications. Supercritical carbon dioxide (CO2) is particularly attractive because it is capable of achieving relatively high power conversion cycle efficiencies in the temperature range between 550°C and 750°C. Therefore, it has the potential for use with any type of high-temperature nuclear reactor concept, assuming reactor core outlet temperatures of at least 550°C. The particular power cycle investigated in this paper is a supercritical CO2 Recompression Brayton Cycle. The CO2 Recompression Brayton Cycle can be used as either a direct or indirect power conversion cycle, depending on the reactor type and reactor outlet temperature. The advantage of this cycle when compared to the helium Brayton Cycle is the lower required operating temperature; 550°C versus 850°C. However, the supercritical CO2 Recompression Brayton Cycle requires an operating pressure in the range of 20 MPa, which is considerably higher than the required helium Brayton cycle operating pressure of 8 MPa. This paper presents results of analyses performed using the UniSim process analyses software to evaluate the performance of the supercritical CO2 Brayton Recompression Cycle for different reactor outlet temperatures. The UniSim model assumed a 600 MWt reactor power source, which provides heat to the power cycle at a maximum temperature of between 550°C and 750°C. The UniSim model used realistic component parameters and operating conditions to model the complete power conversion system. CO2 properties were evaluated, and the operating range for the cycle was adjusted to take advantage of the rapidly changing conditions near the critical point. The UniSim model was then optimized to maximize the power cycle thermal efficiency at the different maximum power cycle operating temperatures. The results of the analyses showed that power cycle thermal efficiencies in the range of 40 to 50% can be achieved.

Edwin A. Harvego; Michael G. McKellar

2011-05-01T23:59:59.000Z

428

Life Cycle Analysis: Integrated Gasification Combined Cycle (IGCC) Power Plant  

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

Life Cycle Analysis: Integrated Life Cycle Analysis: Integrated Gasification Combined Cycle (IGCC) Power Plant Revision 2, March 2012 DOE/NETL-2012/1551 Disclaimer This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or

429

Development of the Hybrid Sulfur Thermochemical Cycle  

DOE Green Energy (OSTI)

The production of hydrogen via the thermochemical splitting of water is being considered as a primary means for utilizing the heat from advanced nuclear reactors to provide fuel for a hydrogen economy. The Hybrid Sulfur (HyS) Process is one of the baseline candidates identified by the U.S. Department of Energy [1] for this purpose. The HyS Process is a two-step hybrid thermochemical cycle that only involves sulfur, oxygen and hydrogen compounds. Recent work has resulted in an improved process design with a calculated overall thermal efficiency (nuclear heat to hydrogen, higher heating value basis) approaching 50%. Economic analyses indicate that a nuclear hydrogen plant employing the HyS Process in conjunction with an advanced gas-cooled nuclear reactor system can produce hydrogen at competitive prices. Experimental work has begun on the sulfur dioxide depolarized electrolyzer, the major developmental component in the cycle. Proof-of-concept tests have established proton-exchange-membrane cells (a state-of-the-art technology) as a viable approach for conducting this reaction. This is expected to lead to more efficient and economical cell designs than were previously available. Considerable development and scale-up issues remain to be resolved, but the development of a viable commercial-scale HyS Process should be feasible in time to meet the commercialization schedule for Generation IV gas-cooled nuclear reactors.

Summers, William A.; Steimke, John L

2005-09-23T23:59:59.000Z

430

Uncertainty quantification of limit-cycle oscillations  

SciTech Connect

Different computational methodologies have been developed to quantify the uncertain response of a relatively simple aeroelastic system in limit-cycle oscillation, subject to parametric variability. The aeroelastic system is that of a rigid airfoil, supported by pitch and plunge structural coupling, with nonlinearities in the component in pitch. The nonlinearities are adjusted to permit the formation of a either a subcritical or supercritical branch of limit-cycle oscillations. Uncertainties are specified in the cubic coefficient of the torsional spring and in the initial pitch angle of the airfoil. Stochastic projections of the time-domain and cyclic equations governing system response are carried out, leading to both intrusive and non-intrusive computational formulations. Non-intrusive formulations are examined using stochastic projections derived from Wiener expansions involving Haar wavelet and B-spline bases, while Wiener-Hermite expansions of the cyclic equations are employed intrusively and non-intrusively. Application of the B-spline stochastic projection is extended to the treatment of aerodynamic nonlinearities, as modeled through the discrete Euler equations. The methodologies are compared in terms of computational cost, convergence properties, ease of implementation, and potential for application to complex aeroelastic systems.

Beran, Philip S. [Multidisciplinary Technologies Center, Air Vehicles Directorate, AFRL/VASD, Building 146, 2210 Eighth Street, WPAFB, OH 45433 (United States)]. E-mail: philip.beran@wpafb.af.mil; Pettit, Chris L. [United States Naval Academy, 590 Holloway Rd., MS 11-B, Annapolis, MD 21402 (United States)]. E-mail: pettitcl@usna.edu; Millman, Daniel R. [USAF TPS/EDT, 220 South Wolfe Ave, Bldg. 1220, Rm. 131, Edwards AFB, CA 93524-6485 (United States)]. E-mail: daniel.millman@edwards.af.mil

2006-09-01T23:59:59.000Z

431

Heat Cycle Research Experimental Program, FY-1985  

DOE Green Energy (OSTI)

The Heat Cycle Research Program, which is being conducted for the Department of Energy, has as its objective the development of the technology for effecting improved utilization of moderate temperature geothermal resources. Testing at the Heat cycle Research Facility located at the DOE Geothermal Test Facility, East Mesa, California is presently being conducted to meet this objective. Current testing involves a supercritical vaporization and counterflow in-tube condensing system. The paper presents a brief description of the test facility and a discussion of the test program. Results of the experiments for the supercritical heaters and the countercurrent, vertical, in-tube condenser are given for both pure and mixed-hydrocarbon working fluids. The heater and condenser behavior predicted by the Heat Transfer Research Institute computer codes used for correlation of the data was in excellent agreement with experimental results. Preliminary results of tests in which the turbine expansion ''passed through the two-phase region'' did not indicate efficiency degradation assignable to these metastable expansion processes. 6 refs., 9 figs.

Bliem, C.J.; Demuth, O.J.; Mines, G.L.; Whitbeck, J.F.

1985-01-01T23:59:59.000Z

432

ITER Progress  

E-Print Network (OSTI)

With nearly 700 FED members and a strong financial balance sheet, I am pleased to report that the state of our Fusion Energy Division is strong. I would like to take this opportunity to thank our previous Chair, Professor Jake Blanchard (University of Wisconsin-Madison) for his tireless efforts on behalf of FED. This letter summarizes some of the ongoing activities at ANS, plans for the 17 th ANS Topical Meeting on the Technology of Fusion Energy (TOFE), and activities related to the Fusion Energy Science Advisory Committee (FESAC). FESAC As Chair of the ANS Fusion Energy Division, I am honored to serve as an Ex-Officio member of FESAC. During my tenure on the Committee, FESAC has so far met only once (July 19, 2005). Among the presentations given at that meeting was a report by the Facilities Panel chaired by Dr. Jill Dahlberg of NRL. The Panel was appointed following a request from Dr. Orbach in April of 2005 and charged with identifying the “unique and complimentary characteristics of each of the three major US toroidal fusion facilities ” (C-MOD, DIII-D, and NSTX), how the three facilities contribute to fusion science and the

Miley Hora; Strait Taylor

2005-01-01T23:59:59.000Z

433

Economic Analyiss of "Symbiotic" Light Water Reactor/Fast Burner Reactor Fuel Cycles Proposed as Part of the U.S. Advanced Fuel Cycle Initiative (AFCI)  

Science Conference Proceedings (OSTI)

A spreadsheet-based 'static equilibrium' economic analysis was performed for three nuclear fuel cycle scenarios, each designed for 100 GWe-years of electrical generation annually: (1) a 'once-through' fuel cycle based on 100% LWRs fueled by standard UO2 fuel assemblies with all used fuel destined for geologic repository emplacement, (2) a 'single-tier recycle' scenario involving multiple fast burner reactors (37% of generation) accepting actinides (Pu,Np,Am,Cm) from the reprocessing of used fuel from the uranium-fueled LWR fleet (63% of generation), and (3) a 'two-tier' 'thermal+fast' recycle scenario where co-extracted U,Pu from the reprocessing of used fuel from the uranium-fueled part of the LWR fleet (66% of generation) is recycled once as full-core LWR MOX fuel (8% of generation), with the LWR MOX used fuel being reprocessed and all actinide products from both UO2 and MOX used fuel reprocessing being introduced into the closed fast burner reactor (26% of generation) fuel cycle. The latter two 'closed' fuel cycles, which involve symbiotic use of both thermal and fast reactors, have the advantages of lower natural uranium requirements per kilowatt-hour generated and less geologic repository space per kilowatt-hour as compared to the 'once-through' cycle. The overall fuel cycle cost in terms of $ per megawatt-hr of generation, however, for the closed cycles is 15% (single tier) to 29% (two-tier) higher than for the once-through cycle, based on 'expected values' from an uncertainty analysis using triangular distributions for the unit costs for each required step of the fuel cycle. (The fuel cycle cost does not include the levelized reactor life cycle costs.) Since fuel cycle costs are a relatively small percentage (10 to 20%) of the overall busbar cost (LUEC or 'levelized unit electricity cost') of nuclear power generation, this fuel cycle cost increase should not have a highly deleterious effect on the competitiveness of nuclear power. If the reactor life cycle costs are included in the analysis, with the fast reactors having a higher $/kw(e) capital cost than the LWRs, the overall busbar generation cost ($/MWh) for the closed cycles is approximately 12% higher than for the all-LWR once-through fuel cycle case, again based on the expected values from an uncertainty analysis. It should be noted that such a percentage increase in the cost of nuclear power is much smaller than that expected for fossil fuel electricity generation if CO2 is costed via a carbon tax, cap and trade regimes, or carbon capture and sequestration (CCS).

Williams, Kent Alan [ORNL; Shropshire, David E. [Idaho National Laboratory (INL)

2009-01-01T23:59:59.000Z

434

International nuclear fuel cycle fact book. [Contains glossary  

SciTech Connect

As the US Department of Energy (DOE) and DOE contractors have become increasingly involved with other nations in nuclear fuel cycle and waste management cooperative activities, a need has developed for a ready source of information concerning foreign fuel cycle programs, facilities, and personnel. This Fact Book was compiled to meet that need. The information contained has been obtained from nuclear trade journals and newsletters; reports of foreign visits and visitors; CEC, IAEA, and OECD/NEA activities reports; proceedings of conferences and workshops; and so forth. Sources do not agree completely with each other, and the data listed herein does not reflect any one single source but frequently is a consolidation/combination of information. Lack of space as well as the intent and purpose of the Fact Book limit the given information to that pertaining to the Nuclear Fuel Cycle and to data considered of primary interest or most helpful to the majority of users.

Leigh, I.W.; Lakey, L.T.; Schneider, K.J.; Silviera, D.J.

1987-01-01T23:59:59.000Z

435

International nuclear fuel cycle fact book: Revision 9  

Science Conference Proceedings (OSTI)

The International Nuclear Fuel Cycle Fact Book has been compiled in an effort to provide current data concerning fuel cycle and waste management facilities, R and D programs and key personnel. The Fact Book contains: national summaries in which a section for each country which summarizes nuclear policy, describes organizational relationships and provides addresses, names of key personnel, and facilities information; and international agencies in which a section for each of the international agencies which has significant fuel cycle involvement, and a listing of nuclear societies. The national summaries, in addition to the data described above, feature a small map for each country as well as some general information. The latter is presented from the perspective of the Fact Book user in the United States.

Leigh, I.W.

1989-01-01T23:59:59.000Z

436

Answering Key Fuel Cycle Questions  

Science Conference Proceedings (OSTI)

Given the range of fuel cycle goals and criteria, and the wide range of fuel cycle options, how can the set of options eventually be narrowed in a transparent and justifiable fashion? It is impractical to develop all options. We suggest an approach that starts by considering a range of goals for the Advanced Fuel Cycle Initiative (AFCI) and then posits seven questions, such as whether Cs and Sr isotopes should be separated from spent fuel and, if so, what should be done with them. For each question, we consider which of the goals may be relevant to eventually providing answers. The AFCI program has both ''outcome'' and ''process'' goals because it must address both waste already accumulating as well as completing the fuel cycle in connection with advanced nuclear power plant concepts. The outcome objectives are waste geologic repository capacity and cost, energy security and sustainability, proliferation resistance, fuel cycle economics, and safety. The process objectives are rea diness to proceed and adaptability and robustness in the face of uncertainties.

Piet, S.J.; Dixon, B.W.; Bennett, R.G.; Smith, J.D.; Hill, R.N.

2004-10-03T23:59:59.000Z

437

June 2011, Report of the Fuel Cycle Subcommittee of NEAC | Department of  

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

June 2011, Report of the Fuel Cycle Subcommittee of NEAC June 2011, Report of the Fuel Cycle Subcommittee of NEAC June 2011, Report of the Fuel Cycle Subcommittee of NEAC The Fuel Cycle subcommittee of NEAC met April 25-26 in Albuquerque, New Mexico. The main topics of discussion were the Used Nuclear Fuel (UNF) disposal program, the System Study Program's methodology that is to be used to set priorities for R&D on advanced fuel cycles, and the University Programs. In addition to these, we were briefed on the budget, but have no comments other than a hope for a good outcome and restrict ourselves to general advice until more is known. A current complication in the design of the Fuel Cycle R&D FCRD program is the Blue Ribbon Commission (BRC) which has been created to address the issues involved in long term disposal of used nuclear fuel (UNF) and any of

438

June 2011, Report of the Fuel Cycle Subcommittee of NEAC | Department of  

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

June 2011, Report of the Fuel Cycle Subcommittee of NEAC June 2011, Report of the Fuel Cycle Subcommittee of NEAC June 2011, Report of the Fuel Cycle Subcommittee of NEAC The Fuel Cycle subcommittee of NEAC met April 25-26 in Albuquerque, New Mexico. The main topics of discussion were the Used Nuclear Fuel (UNF) disposal program, the System Study Program's methodology that is to be used to set priorities for R&D on advanced fuel cycles, and the University Programs. In addition to these, we were briefed on the budget, but have no comments other than a hope for a good outcome and restrict ourselves to general advice until more is known. A current complication in the design of the Fuel Cycle R&D FCRD program is the Blue Ribbon Commission (BRC) which has been created to address the issues involved in long term disposal of used nuclear fuel (UNF) and any of

439

Development of the prototype pneumatic transfer system for ITER neutron activation system  

SciTech Connect

The neutron activation system (NAS) measures neutron fluence at the first wall and the total neutron flux from the ITER plasma, providing evaluation of the fusion power for all operational phases. The pneumatic transfer system (PTS) is one of the key components of the NAS for the proper operation of the system, playing a role of transferring encapsulated samples between the capsule loading machine, irradiation stations, counting stations, and disposal bin. For the validation and the optimization of the design, a prototype of the PTS was developed and capsule transfer tests were performed with the developed system.

Cheon, M. S.; Seon, C. R.; Pak, S.; Lee, H. G. [ITER Korea, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of); Bertalot, L. [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance (France)

2012-10-15T23:59:59.000Z

440

Concept development for the ITER equatorial port visible/infrared wide angle viewing system  

Science Conference Proceedings (OSTI)

The ITER equatorial port visible/infrared wide angle viewing system concept is developed from the measurement requirements. The proposed solution situates 4 viewing systems in the equatorial ports 3, 9, 12, and 17 with 4 views each (looking at the upper target, the inner divertor, and tangentially left and right). This gives sufficient coverage. The spatial resolution of the divertor system is 2 times higher than the other views. For compensation of vacuum-vessel movements, an optical hinge concept is proposed. Compactness and low neutron streaming is achieved by orienting port plug doglegs horizontally. Calibration methods, risks, and R and D topics are outlined.

Reichle, R.; Beaumont, B.; Boilson, D.; Bouhamou, R.; Direz, M.-F.; Encheva, A.; Henderson, M.; Kazarian, F.; Lamalle, Ph.; Lisgo, S.; Mitteau, R.; Patel, K. M.; Pitcher, C. S.; Pitts, R. A.; Prakash, A.; Raffray, R.; Schunke, B.; Snipes, J.; Diaz, A. Suarez; Udintsev, V. S. [ITER Organization, Route de Vinon-sur-Verdon, 13115 St Paul-lez-Durance (France); and others

2012-10-15T23:59:59.000Z

Note: This page contains sample records for the topic "involves iterative cycling" 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

Alpha Heating in ITER L-mode and H-mode Plasma  

Science Conference Proceedings (OSTI)

There are many uses of predictions of ITER plasma performance. One is assessing requirements of different plasma regimes. For instance, what current drive and control are needed for steady state. The heating, current drive, and torque systems planned for initial DT operation are negative ion neutral beam injection (NB), ion cyclotron resonance (IC), and electron cyclotron resonance (EC). Which combinations of heating are optimal. What are benefits of the torques, current drive, and fueling using NB. What are the shine-through power and optimum voltage for the NB? What are optimal locations and aiming of the EC launchers? Another application is nuclear licensing (e.g. System integrity, how many neutrons).

R.V. Budny

2011-07-18T23:59:59.000Z

442

Applying Remote Handling Attributes to the ITER Neutral Beam Cell Monorail Crane  

E-Print Network (OSTI)

The maintenance requirements for the equipment in the ITER Neutral Beam Cell requires components to be lifted and transported within the cell by remote means. To meet this requirement, the provision of an overhead crane with remote handling capabilities has been initiated. The layout of the cell has driven the design to consist of a monorail crane that travels on a branched monorail track attached to the cell ceiling. This paper describes the principle design constraints and how the remote handling attributes were applied to the concept design of the monorail crane, concentrating on areas where novel design solutions have been required and on the remote recovery requirements and solutions.

Crofts, O; Raimbach, J; Tesini, A; Choi, C-H; Damiani, C; Van Uffelen, M

2013-01-01T23:59:59.000Z

443

Integrated modelling of steady-state scenarios and heating and current drive mixes for ITER  

Science Conference Proceedings (OSTI)

Recent progress on ITER steady-state (SS) scenario modelling by the ITPA-IOS group is reviewed. Code-to-code benchmarks as the IOS group's common activities for the two SS scenarios (weak shear scenario and internal transport barrier scenario) are discussed in terms of transport, kinetic profiles, and heating and current drive (CD) sources using various transport codes. Weak magnetic shear scenarios integrate the plasma core and edge by combining a theory-based transport model (GLF23) with scaled experimental boundary profiles. The edge profiles (at normalized radius rho = 0.8-1.0) are adopted from an edge-localized mode-averaged analysis of a DIII-D ITER demonstration discharge. A fully noninductive SS scenario is achieved with fusion gain Q = 4.3, noninductive fraction f(NI) = 100%, bootstrap current fraction f(BS) = 63% and normalized beta beta(N) = 2.7 at plasma current I(p) = 8MA and toroidal field B(T) = 5.3 T using ITER day-1 heating and CD capability. Substantial uncertainties come from outside the radius of setting the boundary conditions (rho = 0.8). The present simulation assumed that beta(N)(rho) at the top of the pedestal (rho = 0.91) is about 25% above the peeling-ballooning threshold. ITER will have a challenge to achieve the boundary, considering different operating conditions (T(e)/T(i) approximate to 1 and density peaking). Overall, the experimentally scaled edge is an optimistic side of the prediction. A number of SS scenarios with different heating and CD mixes in a wide range of conditions were explored by exploiting the weak-shear steady-state solution procedure with the GLF23 transport model and the scaled experimental edge. The results are also presented in the operation space for DT neutron power versus stationary burn pulse duration with assumed poloidal flux availability at the beginning of stationary burn, indicating that the long pulse operation goal (3000s) at I(p) = 9 MA is possible. Source calculations in these simulations have been revised for electron cyclotron current drive including parallel momentum conservation effects and for neutral beam current drive with finite orbit and magnetic pitch effects.

Murakami, Masanori [ORNL; Park, Jin Myung [ORNL

2011-01-01T23:59:59.000Z

444

ITER Model Coil Tests Overview: Nb3Sn Strand Properties in Cable-in-Conduit-Conductors  

SciTech Connect

During the ITER Model Coil Program two large coils and three Insert coils were built and tested. The test campaigns provided very valuable data on the Conductor in Conduit Cable (CICC) properties. The tests showed that the Nb3Sn strands in CICC behave differently than so-called witness strands, which underwent the same heat treatment. The paper describes Volt-temperature characteristics (VTC) and Volt-Ampere characteristics (VAC) measured in the tests, presents comparisons with the witness strands, and interprets the test results.

Martovetsky, N N

2003-04-14T23:59:59.000Z

445

On the iterated Crank-Nicolson for hyperbolic and parabolic equations in numerical relativity  

E-Print Network (OSTI)

The iterated Crank-Nicolson is a predictor-corrector algorithm commonly used in numerical relativity for the solution of both hyperbolic and parabolic partial differential equations. We here extend the recent work on the stability of this scheme for hyperbolic equations by investigating the properties when the average between the predicted and corrected values is made with unequal weights and when the scheme is applied to a parabolic equation. We also propose a variant of the scheme in which the coefficients in the averages are swapped between two corrections leading to systematically larger amplification factors and to a smaller numerical dispersion.

Gregor Leiler; Luciano Rezzolla

2006-01-31T23:59:59.000Z

446

An Iterative Method for Constructing Equilibrium Phase Models of Stellar Systems  

E-Print Network (OSTI)

We present a new method for constructing equilibrium phase models for stellar systems, which we call the iterative method. It relies on constrained, or guided evolution, so that the equilibrium solution has a number of desired parameters and/or constraints. This method is very powerful, to a large extent due to its simplicity. It can be used for mass distributions with an arbitrary geometry and a large variety of kinematical constraints. We present several examples illustrating it. Applications of this method include the creation of initial conditions for N-body simulations and the modelling of galaxies from their photometric and kinematic observations.

S. A. Rodionov; E. Athanassoula; N. Ya Sotnikova

2008-08-14T23:59:59.000Z

447

Ultrafast thermal cycling of solar panels  

SciTech Connect

Two new cyclers that utilize a novel hybrid approach to perform fast thermal cycling of solar panels have been built and are now operational in the Mechanics and Materials Technology Center at The Aerospace Corporation. These cyclers are part of a continuing effort to minimize solar cell life test durations by accelerating the cycling rates. These fully automated cyclers, which provide continuous unmanned cycling in a gaseous nitrogen atmosphere, can execute 5 min cycles, thus yielding in excess of 100,000 cycles per year. They also have a unique capability of verifying solar panel functionality without interruption of cycling, so that cycling doesn`t continue on nonfunctioning panels.

Wall, T.S.; Valenzuela, P.R.; Sue, C.

1998-08-15T23:59:59.000Z

448

Community Involvement Fund | Department of Energy  

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

Community Involvement Community Involvement Fund Community Involvement Fund Community Involvement Fund Community Involvement Fund Community Involvement Fund Community Involvement Fund Community Involvement Fund Community Involvement Fund Community Involvement Fund Community Involvement Fund Overview The success of EM's legacy waste cleanup mission depends largely on the support of informed and engaged stakeholders. Cleanup activities have the potential to affect the health of the public, the environment, and the future of the communities that either host or are located near EM sites. Therefore, it is critical that EM receive public input from local citizens and community organizations prior to making cleanup decisions. In December 2010, EM partnered with the New Mexico Community Foundation

449

Stability and bifurcations of heteroclinic cycles of type Z  

E-Print Network (OSTI)

Dynamical systems that are invariant under the action of a non-trivial symmetry group can possess structurally stable heteroclinic cycles. In this paper we study stability properties of a class of structurally stable heteroclinic cycles in R^n which we call heteroclinic cycles of type Z. It is well-known that a heteroclinic cycle that is not asymptotically stable can attract nevertheless a positive measure set from its neighbourhood. We say that an invariant set X is fragmentarily asymptotically stable, if for any delta>0 the measure of its local basin of attraction B_delta(X) is positive. A local basin of attraction B_delta(X) is the set of such points that trajectories starting there remain in the delta-neighbourhood of X for all t>0, and are attracted by X as t\\to\\infty. Necessary and sufficient conditions for fragmentary asymptotic stability are expressed in terms of eigenvalues and eigenvectors of transition matrices. If all transverse eigenvalues of linearisations near steady states involved in the cycle are negative, then fragmentary asymptotic stability implies asymptotic stability. In the latter case the condition for asymptotic stability is that the transition matrices have an eigenvalue larger than one in absolute value. Finally, we discuss bifurcations occurring when the conditions for asymptotic stability or for fragmentary asymptotic stability are broken.

Olga Podvigina

2011-08-21T23:59:59.000Z

450

H gas turbine combined cycle  

SciTech Connect

A major step has been taken in the development of the Next Power Generation System--``H`` Technology Combined Cycle. This new gas turbine combined-cycle system increases thermal performance to the 60% level by increasing gas turbine operating temperature to 1,430 C (2,600 F) at a pressure ratio of 23 to 1. Although this represents a significant increase in operating temperature for the gas turbine, the potential for single digit NOx levels (based upon 15% O{sub 2}, in the exhaust) has been retained. The combined effect of performance increase and environmental control is achieved by an innovative closed loop steam cooling system which tightly integrates the gas turbine and steam turbine cycles. The ``H`` Gas Turbine Combined Cycle System meets the goals and objectives of the DOE Advanced Turbine System Program. The development and demonstration of this new system is being carried out as part of the Industrial/Government cooperative agreement under the ATS Program. This program will achieve first commercial operation of this new system before the end of the century.

Corman, J.

1995-12-31T23:59:59.000Z

451

LDPC codes from Singer cycles  

Science Conference Proceedings (OSTI)

The main goal of coding theory is to devise efficient systems to exploit the full capacity of a communication channel, thus achieving an arbitrarily small error probability. Low Density Parity Check (LDPC) codes are a family of block codes-characterised ... Keywords: LDPC Codes, Projective spaces, Singer cycles

Luca Giuzzi; Angelo Sonnino

2009-04-01T23:59:59.000Z

452

Development of a Twin-Screw D-2 Extruder for the ITER Pellet Injection System  

SciTech Connect

A twin-screw extruder for the ITER pellet injection system is under development at the Oak Ridge National Laboratory. The extruder will provide a stream of solid hydrogen isotopes to a secondary section, where pellets are cut and accelerated with single-stage gas gun into the plasma. A one-fifth ITER scale prototype extruder has been built to produce a continuous solid deuterium extrusion. Deuterium gas is precooled and liquefied before being introduced into the extruder. The precooler consists of a copper vessel containing liquid nitrogen surrounded by a deuterium gas filled copper coil. The liquefier is comprised of a copper cylinder connected to a Cryomech AL330 cryocooler, which is surrounded by a copper coil that the precooled deuterium flows through. The lower extruder barrel is connected to a Cryomech GB-37 cryocooler to solidify the deuterium (at approximate to 15 K) before it is forced through the extruder nozzle. A viewport located below the extruder nozzle provides a direct view of the extrusion. A camera is used to document the extrusion quality and duration. A data acquisition system records the extruder temperatures, torque, and speed, upstream, and downstream pressures. This paper will describe the prototype twin-screw extruder and initial extrusion results.

Meitner, Steven J [ORNL; Baylor, Larry R [ORNL; Carbajo, Juan J [ORNL; Combs, Stephen Kirk [ORNL; Fehling, Dan T [ORNL; Foust, Charles R [ORNL; McFee, Marshall T [ORNL; McGill, James M [ORNL; Rasmussen, David A [ORNL; Sitterson, R G [ORNL; Sparks, Dennis O [ORNL; Qualls, A L [ORNL

2009-07-01T23:59:59.000Z

453

A protection system for the JET ITER-like wall based on imaging diagnostics  

SciTech Connect

The new JET ITER-like wall (made of beryllium and tungsten) is more fragile than the former carbon fiber composite wall and requires active protection to prevent excessive heat loads on the plasma facing components (PFC). Analog CCD cameras operating in the near infrared wavelength are used to measure surface temperature of the PFCs. Region of interest (ROI) analysis is performed in real time and the maximum temperature measured in each ROI is sent to the vessel thermal map. The protection of the ITER-like wall system started in October 2011 and has already successfully led to a safe landing of the plasma when hot spots were observed on the Be main chamber PFCs. Divertor protection is more of a challenge due to dust deposits that often generate false hot spots. In this contribution we describe the camera, data capture and real time processing systems. We discuss the calibration strategy for the temperature measurements with cross validation with thermal IR cameras and bi-color pyrometers. Most importantly, we demonstrate that a protection system based on CCD cameras can work and show examples of hot spot detections that stop the plasma pulse. The limits of such a design and the associated constraints on the operations are also presented.

Arnoux, G.; Balboa, I.; Balshaw, N.; Beldishevski, M.; Cramp, S.; Felton, R.; Goodyear, A.; Horton, A.; Kinna, D.; McCullen, P.; Obrejan, K.; Patel, K.; Lomas, P. J.; Rimini, F.; Stamp, M.; Stephen, A.; Thomas, P. D.; Williams, J.; Wilson, J.; Zastrow, K.-D. [Euratom/CCFE Fusion Association, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); and others

2012-10-15T23:59:59.000Z

454

Stray RF Power Estimates From EC Exploitation During ITER Plasma Operations  

SciTech Connect

The EC H and CD system of ITER tokamak is an essential tool for all the phases of ITER operation. Different levels of EC power are required through all the plasma discharge: up to 6.7 MW for assisting the breakdown and burn through, up to 20 MW for current drive and saw-teeth control from the equatorial launcher and up to 20 MW for NTM stabilization from the upper launchers. The assistance to breakdown and burn through is characterized by a very low (if not negligible) RF power absorption by the plasma. A significant level of stray radiation may also arise from partial absorption due to non-optimal plasma parameters and/or wrong injected polarization. The stray power radiated in the vacuum chamber is estimated as a first step toward mitigating potential harmful consequence to in-vessel structures and diagnostics. Power loading of the chamber walls (peek power and average power density for straight beam propagation in the empty chamber) and diffuse stray radiation effects are simulated to infer suitable strategies to avoid damage to first wall and to microwave sensitive components.

Gandini, F.; Henderson, M.; Darbos, C.; Gassmann, T.; Purohit, D.; Omori, T. [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance (France); Nazare, C. [Assystem Facilities, 78067 Saint Quentin en Yvelines Cedex (France)

2011-12-23T23:59:59.000Z

455

ITER Core Imaging X-Ray Spectrometer Conceptual Design and Performance Assessment - Phase 2  

SciTech Connect

During Phase 2 of our study of the CIXS conceptual design we have tackled additional important issues that are unique to the ITER environment. These include the thermal control of the crystal and detector enclosures located in an environment with a 100-250 C ambient temperature, tritium containment, and the range of crystal and detector movement based on the need for spectral adjustments and the desire to make measurements of colder plasmas. In addressing these issues we have selected a ''Dewar''-type enclosure for the crystals and detectors. Applying realistic view factors for radiant heat and making allowance for conduction we have made engineering studies of this enclosure and showed that the cooling requirements can be solved and the temperature can be kept sufficiently constant without compromising the specification parameters of the CIXS. We have chosen a minimum 3 mm combined thickness of the six beryllium windows needed in a Dewar-type enclosure and showed that a single window of 0.5 mm thickness satisfies tritium containment requirements. For measuring the temperature in cooler ITER plasmas, we have chosen to use the K-shell lines of Fe24+. Iron is the preferred choice because its radiation can be analyzed with the identical CIXS settings used for analyzing the tungsten radiation, i.e., essentially no adjustments besides a simple crystal rotation need to be made. We have, however, included an xy{theta}-drive motor arrangement in our design for fine adjustments and full rotation of the crystal mounts.

Beiersdorfer, P; Wen, J; Dunn, J; Morris, K

2011-01-02T23:59:59.000Z

456

Modeling and Simulation of the ITER First Wall/Blanket Primary Heat Transfer System  

SciTech Connect

ITER inductive power operation is modeled and simulated using a thermal-hydraulics system code (RELAP5) integrated with a 3-D CFD (SC-Tetra) code. The Primary Heat Transfer System (PHTS) functions are predicted together with the main parameters operational ranges. The control algorithm strategy and derivation are summarized as well. The First Wall and Blanket modules are the primary components of PHTS, used to remove the major part of the thermal heat from the plasma. The modules represent a set of flow channels in solid metal structure that serve to absorb the radiation heat and nuclear heating from the fusion reactions and to provide shield for the vacuum vessel. The blanket modules are water cooled. The cooling is forced convective with constant blanket inlet temperature and mass flow rate. Three independent water loops supply coolant to the three blanket sectors. The main equipment of each loop consists of a pump, a steam pressurizer and a heat exchanger. A major feature of ITER is the pulsed operation. The plasma does not burn continuously, but on intervals with large periods of no power between them. This specific feature causes design challenges to accommodate the thermal expansion of the coolant during the pulse period and requires active temperature control to maintain a constant blanket inlet temperature.

Ying, Alice [University of California, Los Angeles; Popov, Emilian L [ORNL

2011-01-01T23:59:59.000Z

457

A new visible spectroscopy diagnostic for the JET ITER-like wall main chamber  

Science Conference Proceedings (OSTI)

In preparation for ITER, JET has been upgraded with a new ITER-like wall (ILW), whereby the main plasma facing components, previously of carbon, have been replaced by mainly Be in the main chamber and W in the divertor. As part of the many diagnostic enhancements, a new, survey, visible spectroscopy diagnostic has been installed for the characterization of the ILW. An array of eight lines-of-sight (LOS) view radially one of the two JET neutral beam shine through areas (W coated carbon fibre composite tiles) at the inner wall. In addition, one vertical LOS views the solid W tile at the outer divertor. The light emitted from the plasma is coupled to a series of compact overview spectrometers, with overall wavelength range of 380-960 nm and to one high resolution Echelle overview spectrometer covering the wavelength range 365-720 nm. The new survey diagnostic has been absolutely calibrated in situ by means of a radiometric light source placed inside the JET vessel in front of the whole optical path and operated by remote handling. The diagnostic is operated in every JET discharge, routinely monitoring photon fluxes from intrinsic and extrinsic impurities (e.g., Be, C, W, N, and Ne), molecules (e.g., BeD, D{sub 2}, ND) and main chamber and divertor recycling (typically D{alpha}, D{beta}, and D{gamma}). The paper presents a technical description of the diagnostic and first measurements during JET discharges.

Maggi, C. F. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, D-85748 Garching (Germany); Brezinsek, S. [Forschungszentrum Juelich GmbH, EURATOM Association, D-52425 Juelich (Germany); Stamp, M. F.; Griph, S.; Heesterman, P.; Hogben, C.; Horton, A.; Meigs, A.; Studholme, W.; Zastrow, K.-D. [EURATOM/CCFE, Fusion Association, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Morlock, C. [EFDA-CSU Garching, Boltzmannstrasse 2, 85748 Garching (Germany); Collaboration: JET-EFDA Contributors

2012-10-15T23:59:59.000Z

458

Recent Advances on Hydrogenic Retention in ITER's Plasma-Facing Materials: BE, C, W.  

SciTech Connect

Management of tritium inventory remains one of the grand challenges in the development of fusion energy and the choice of plasma-facing materials is a key factor for in-vessel tritium retention. The Atomic and Molecular Data Unit of the International Atomic Energy Agency organized a Coordinated Research Project (CRP) on the overall topic of tritium inventory in fusion reactors during the period 2001-2006. This dealt with hydrogenic retention in ITER's plasma-facing materials, Be, C, W, and in compounds (mixed materials) of these elements as well as tritium removal techniques. The results of the CRP are summarized in this article together with recommendations for ITER. Basic parameters of diffusivity, solubility and trapping in Be, C and W are reviewed. For Be, the development of open porosity can account for transient hydrogenic pumping but long term retention will be dominated by codeposition. Codeposition is also the dominant retention mechanism for carbon and remains a serious concern for both Be and C containing layers. Hydrogenic trapping in unirradiated tungsten is low but will increase with ion and neutron damage. Mixed materials will be formed in a tokamak and these can also retain significant amounts of hydrogen isotopes. Oxidative and photon-based techniques for detritiation of plasma-facing components are described.

Skinner, C H; Alimov, Kh; Bekris, N; Causey, R A; Clark, R.E.H.; Coad, J P; Davis, J W; Doerner, R P; Mayer, M; Pisarev, A; Roth, J

2008-03-29T23:59:59.000Z

459

ITER Progress Highlights of the 8 th IAEA Technical Meeting on Fusion Power Plant Safety  

E-Print Network (OSTI)

First, I would like to personally thank Dr. Said Abdel-Khalik, the outgoing chair of the Fusion Energy Division (FED), for his service during his term. Said now serves not only as the past chair, but he has assumed the role of FED’s liaison to the ANS Public Policy Committee. I am pleased to report that the state of our division is quite strong. Division membership has exceeded 750 for three years in a row, and the student membership has grown to more than 200. These numbers reflect the strength and growth in the fusion community. ITER has ramped up dramatically in recent months with many team members moving from Naka and Garching to the Joint Work site in Cadarache, France. Current plans call for delivery of a new baseline design in the late spring of next year. In the U.S., NIF has demonstrated its full system performance on a single beam basis and is expected to have 25 % of the beams operational by January 2007. Truly, it is a very exciting time in the fusion community! Recently, Dr. Susana Reyes left the United States for a new position with the ITER safety team. In order to give her utmost attention to this exciting opportunity, Susana elected to

Plan U. S; Participation Iter

2006-01-01T23:59:59.000Z

460

Alcator C-Mod Experiments in Support of the ITER Baseline 15 MA Scenario  

SciTech Connect

Experiments on Alcator C-Mod have addressed several issues for the ITER 15 MA baseline scenario from 2009-2012. Rampup studies show ICRF can save significant V-s, and that an H-mode in the ramp can be utilized to save 50% more. ICRF modifications to li(1) are minimal, although the Te profile is peaked relative to ohmic in the plasma center, and alter sawtooth onset times. Rampdown studies show H-modes can be routinely sustained, avoiding an OH coil over-current associated with the H-L transition, that fast rampdowns are preferred, the density drops with Ip, and that the H-L transition occurs at Ploss/Pthr,LH ~ 1.0-1.3 at n/nGr ~ 0.85. Flattop plasmas targeting ITER baseline parameters have been sustained for 20 ?E or 8-13 ?CR, but only reach H98 ~ 0.6 at n/nGr = 0.85, rising to 0.9 at n/nGr = 0.65.

C Kessel, et al

2013-05-07T23:59:59.000Z

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461

Comparison and Analysis of Twist Pitch Length Test Methods for ITER Nb3Sn and NbTi Strands  

E-Print Network (OSTI)

A twisted multifilamentary structure is needed for Nb3Sn and NbTi strands to be used in the International Thermonuclear Experimental Reactor (ITER) magnets. As important parameters for the superconducting strands design and production, the twist pitch length and direction of strands must meet the requirements according to ITER Procurement Arrangement (PA) and this must be verified. The technical requirements are 15mm+/-2mm for twist pitch length and right hand twist for direction. The strand twist pitch and the twist direction can be measured on straight sections of strand, which is recognized by the repetition of filament bundles or by the angle of the filaments. Several test methods and results are described and compared in this paper. The accuracy, uncertainty and feasibility of different methods are analyzed and recommended measurement methods are proposed for ITER strands verification.

Fang Liu; Feng Long; Chao Chen; Bo Liu; Yu Wu; Huajun Liu

2013-05-08T23:59:59.000Z

462

CFD MODELING OF ITER CABLE-IN-CONDUIT SUPERCONDUCTORS. PART V: COMBINED MOMENTUM AND HEAT TRANSFER IN RIB ROUGHENED PIPES  

Science Conference Proceedings (OSTI)

Computational Fluid Dynamics (CFD) techniques have been proposed and applied in a series of papers to analyze cable-in-conduit conductors (CICC) for the International Thermonuclear Experimental Reactor (ITER). Previous work on the pressure drop in the central channel of ITER CICC is extended here to the problem of combined heat and momentum transfer. The CFD model, solved by the FLUENT commercial code, is first validated against 2D and 3D data from compact heat exchangers, showing good agreement. The Colburn analogy between the friction factor f and the Nusselt number Nu is not verified in the considered 2D geometries, as shown by both experiment and simulation. The validated CFD model is finally applied to the 3D analysis of central channel-like geometries relevant for ITER CICC. It is shown that the heat transfer coefficient on the central channel side stays relatively close to the smooth-pipe (Dittus-Boelter) value.

Zanino, R.; Giors, S. [Dipartimento di Energetica, Politecnico Torino, I-10129 (Italy)

2008-03-16T23:59:59.000Z

463

Rate Adjustments and Public Involvement  

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

Rate Adjustments and Public Involvement Documents Rate Adjustments and Public Involvement Documents CRSP Transmission 9/16/2013 WAPA-161 FRN, CRSP transmission and ancillary services rates extension Letter announcing two-year extension to CRSP transmission and ancillary services rates Letter announcing revised CRSP transmission rates for FY 2014 Accompanying calculation table for FY 2014 CRSP transmission rate letter Letter announcing revised CRSP transmission rates for FY 2013 Letter announcing revised CRSP transmission rates for FY 2012 Letter announcing revised CRSP transmission rates for FY 2011 Letter announcing revised CRSP transmission rates for FY 2010 SLCA/IP 9/16/2013 WAPA-161 FRN, SLCA/IP firm power rate extension Letter announcing two-year extension to SLCA/IP firm power rate SLCA/IP Tentative Rate Adjustment Schedule

464

Control system options and strategies for supercritical CO2 cycles.  

SciTech Connect

The Supercritical Carbon Dioxide (S-CO{sub 2}) Brayton Cycle is a promising alternative to Rankine steam cycle and recuperated gas Brayton cycle energy converters for use with Sodium-Cooled Fast Reactors (SFRs), Lead-Cooled Fast Reactors (LFRs), as well as other advanced reactor concepts. The S-CO{sub 2} Brayton Cycle offers higher plant efficiencies than Rankine or recuperated gas Brayton cycles operating at the same liquid metal reactor core outlet temperatures as well as reduced costs or size of key components especially the turbomachinery. A new Plant Dynamics Computer Code has been developed at Argonne National Laboratory for simulation of a S-CO{sub 2} Brayton Cycle energy converter coupled to an autonomous load following liquid metal-cooled fast reactor. The Plant Dynamics code has been applied to investigate the effectiveness of a control strategy for the S-CO{sub 2} Brayton Cycle for the STAR-LM 181 MWe (400 MWt) Lead-Cooled Fast Reactor. The strategy, which involves a combination of control mechanisms, is found to be effective for controlling the S-CO{sub 2} Brayton Cycle over the complete operating range from 0 to 100 % load for a representative set of transient load changes. While the system dynamic analysis of control strategy performance for STARLM is carried out for a S-CO{sub 2} Brayton Cycle energy converter incorporating an axial flow turbine and compressors, investigations of the S-CO{sub 2} Brayton Cycle have identified benefits from the use of centrifugal compressors which offer a wider operating range, greater stability near the critical point, and potentially further cost reductions due to fewer stages than axial flow compressors. Models have been developed at Argonne for the conceptual design and performance analysis of centrifugal compressors for use in the SCO{sub 2} Brayton Cycle. Steady state calculations demonstrate the wider operating range of centrifugal compressors versus axial compressors installed in a S-CO{sub 2} Brayton Cycle as well as the benefits in expanding the range over which individual control mechanisms are effective for cycle control. However, a combination of mechanisms is still required for control of the S-CO{sub 2} Brayton Cycle between 0 and 100 % load. An effort is underway to partially validate the Argonne models and codes by means of comparison with data from tests carried out using the small-scale Sandia Brayton Loop (SBL) recuperated gas closed Brayton cycle facility. The centrifugal compressor model has been compared with data from the SBL operating with nitrogen gas and good agreement is obtained between calculations and the measured data for the compressor outlet pressure versus flow rate, although it is necessary to assume values for certain model parameters which require information about the configuration or dimensions of the compressor components that is unavailable. Unfortunately, the compressor efficiency cannot be compared with experiment data due to the lack of outlet temperature data. A radial inflow turbine model has been developed to enable further comparison of calculations with data from the SBL which incorporates both a radial inflow turbine as well as a radial compressor. Preliminary calculations of pressure ratio and efficiency versus flow rate have been carried out using the radial inflow turbine model.

Moisseytsev, A.; Kulesza, K. P.; Sienicki, J. J.; Nuclear Engineering Division; Oregon State Univ.

2009-06-18T23:59:59.000Z

465

Definition: Rankine cycle | Open Energy Information  

Open Energy Info (EERE)

Rankine cycle Rankine cycle Jump to: navigation, search Dictionary.png Rankine cycle Sometimes referred to as the steam cycle. Fuel is used to heat a liquid to produce a high pressure gas that expands and produces work, such as turning a turbine; when the turbine is connected to a generator, it produces electricity. Usually water is the liquid used in the Rankine cycle (to produce steam), but other liquids can also be used. The exhaust vapor expelled from the turbine condenses and the liquid is pumped back to the boiler to repeat the cycle.[1][2] View on Wikipedia Wikipedia Definition The Rankine cycle is a mathematical model that is used to predict the performance of steam engines. The Rankine cycle is an idealised thermodynamic cycle of a heat engine that converts heat into mechanical

466

Medium Truck Duty Cycle (MTDC)  

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

Routes Data Acquisition System Setup Routes Data Acquisition System Setup Medium Truck Duty Cycle (MTDC) Objective This Department of Energy project focuses on the collection and analysis medium truck (Class-6 and -7) duty cycle data from real-world operations. Analysis of this data will provide information pertaining to the fuel efficiencies and performance of medium trucks in several vocations. Outcomes Rich source of data and information that can contribute to the development of new tools Sound basis upon which DOE can make technology investment decisions A national archive of real-world-based medium-truck operational data that will support medium-duty vehicle energy efficiency research Collected Data Speed & Acceleration Fuel Consumption GPS Location Road Grade

467

RAMI Analysis for Designing and Optimizing Tokamak Cooling Water System (TCWS) for the ITER's Fusion Reactor  

SciTech Connect

U.S.-ITER is responsible for the design, engineering, and procurement of the Tokamak Cooling Water System (TCWS). TCWS is designed to provide cooling and baking for client systems that include the first wall/blanket, vacuum vessel, divertor, and neutral beam injector. Additional operations that support these primary functions include chemical control of water provided to client systems, draining and drying for maintenance, and leak detection/localization. TCWS interfaces with 27 systems including the secondary cooling system, which rejects this heat to the environment. TCWS transfers heat generated in the Tokamak during nominal pulsed operation - 850 MW at up to 150 C and 4.2 MPa water pressure. Impurities are diffused from in-vessel components and the vacuum vessel by water baking at 200-240 C at up to 4.4 MPa. TCWS is complex because it serves vital functions for four primary clients whose performance is critical to ITER's success and interfaces with more than 20 additional ITER systems. Conceptual design of this one-of-a-kind cooling system has been completed; however, several issues remain that must be resolved before moving to the next stage of the design process. The 2004 baseline design indicated cooling loops that have no fault tolerance for component failures. During plasma operation, each cooling loop relies on a single pump, a single pressurizer, and one heat exchanger. Consequently, failure of any of these would render TCWS inoperable, resulting in plasma shutdown. The application of reliability, availability, maintainability, and inspectability (RAMI) tools during the different stages of TCWS design is crucial for optimization purposes and for maintaining compliance with project requirements. RAMI analysis will indicate appropriate equipment redundancy that provides graceful degradation in the event of an equipment failure. This analysis helps demonstrate that using proven, commercially available equipment is better than using custom-designed equipment with no field experience and lowers specific costs while providing higher reliability. This paper presents a brief description of the TCWS conceptual design and the application of RAMI tools to optimize the design at different stages during the project.

Ferrada, Juan J [ORNL; Reiersen, Wayne T [ORNL

2011-01-01T23:59:59.000Z

468

Integrated safeguards testing laboratories in support of the advanced fuel cycle initiative  

SciTech Connect

A key enabler for advanced fuel cycle safeguards research and technology development for programs such as the Advanced Fuel Cycle Initiative (AFCI) is access to facilities and nuclear materials. This access is necessary in many cases in order to ensure that advanced safeguards techniques and technologies meet the measurement needs for which they were designed. One such crucial facility is a hot cell based laboratory which would allow developers from universities, national laboratories, and commercial companies to perform iterative research and development of advanced safeguards instrumentation under realistic operating conditions but not be subject to production schedule limitations. The need for such a facility arises from the requirement to accurately measure minor actinide and/or fission product bearing nuclear materials that cannot be adequately shielded in glove boxes. With the contraction of the DOE nuclear complex following the end of the cold war, many suitable facilities at DOE sites are increasingly costly to operate and are being evaluated for closure. A hot cell based laboratory that allowed developers to install and remove instrumentation from the hot cell would allow for both risk mitigation and performance optimization of the instrumentation prior to fielding equipment in facilities where maintenance and repair of the instrumentation is difficult or impossible. These benefits are accomplished by providing developers the opportunity to iterate between testing the performance of the instrumentation by measuring realistic types and amounts of nuclear material, and adjusting and refining the instrumentation based on the results of these measurements. In this paper, we review the requirements for such a facility using the Wing 9 hot cells in the Los Alamos National Laboratory's Chemistry and Metallurgy Research facility as a model for such a facility and describe recent use of these hot cells in support of AFCI.

Santi, Peter A [Los Alamos National Laboratory; Demuth, Scott F [Los Alamos National Laboratory; Klasky, Kristen L [Los Alamos National Laboratory; Lee, Haeok [Los Alamos National Laboratory; Miller, Michael C [Los Alamos National Laboratory; Sprinkle, James K [Los Alamos National Laboratory; Tobin, Stephen J [Los Alamos National Laboratory; Williams, Bradley [DOE, NE

2009-01-01T23:59:59.000Z

469

Optimization and Comparison of Direct and Indirect Supercritical Carbon Dioxide Power Plant Cycles for Nuclear Applications  

Science Conference Proceedings (OSTI)

There have been a number of studies involving the use of gases operating in the supercritical mode for power production and process heat applications. Supercritical carbon dioxide (CO2) is particularly attractive because it is capable of achieving relatively high power conversion cycle efficiencies in the temperature range between 550 C and 750 C. Therefore, it has the potential for use with any type of high-temperature nuclear reactor concept, assuming reactor core outlet temperatures of at least 550 C. The particular power cycle investigated in this paper is a supercritical CO2 Recompression Brayton Cycle. The CO2 Recompression Brayton Cycle can be used as either a direct or indirect power conversion cycle, depending on the reactor type and reactor outlet temperature. The advantage of this cycle when compared to the helium Brayton cycle is the lower required operating temperature; 550 C versus 850 C. However, the supercritical CO2 Recompression Brayton Cycle requires an operating pressure in the range of 20 MPa, which is considerably higher than the required helium Brayton cycle operating pressure of 8 MPa. This paper presents results of analyses performed using the UniSim process analyses software to evaluate the performance of both a direct and indirect supercritical CO2 Brayton Recompression cycle for different reactor outlet temperatures. The direct supercritical CO2 cycle transferred heat directly from a 600 MWt reactor to the supercritical CO2 working fluid supplied to the turbine generator at approximately 20 MPa. The indirect supercritical CO2 cycle assumed a helium-cooled Very High Temperature Reactor (VHTR), operating at a primary system pressure of approximately 7.0 MPa, delivered heat through an intermediate heat exchanger to the secondary indirect supercritical CO2 Brayton Recompression cycle, again operating at a pressure of about 20 MPa. For both the direct and indirect cycles, sensitivity calculations were performed for reactor outlet temperature between 550 C and 850 C. The UniSim models used realistic component parameters and operating conditions to model the complete reactor and power conversion systems. CO2 properties were evaluated, and the operating ranges of the cycles were adjusted to take advantage of the rapidly changing properties of CO2 near the critical point. The results of the analyses showed that, for the direct supercritical CO2 power cycle, thermal efficiencies in the range of 40 to 50% can be achieved. For the indirect supercritical CO2 power cycle, thermal efficiencies were approximately 10% lower than those obtained for the direct cycle over the same reactor outlet temperature range.

Edwin A. Harvego; Michael G. McKellar

2011-11-01T23:59:59.000Z

470

Advanced Fuel Cycle Cost Basis  

SciTech Connect

This report, commissioned by the U.S. Department of Energy (DOE), provides a comprehensive set of cost data supporting a cost analysis for the relative economic comparison of options for use in the Advanced Fuel Cycle Initiative (AFCI) Program. The report describes the AFCI cost basis development process, reference information on AFCI cost modules, a procedure for estimating fuel cycle costs, economic evaluation guidelines, and a discussion on the integration of cost data into economic computer models. This report contains reference cost data for 25 cost modules—23 fuel cycle cost modules and 2 reactor modules. The cost modules were developed in the areas of natural uranium mining and milling, conversion, enrichment, depleted uranium disposition, fuel fabrication, interim spent fuel storage, reprocessing, waste conditioning, spent nuclear fuel (SNF) packaging, long-term monitored retrievable storage, near surface disposal of low-level waste (LLW), geologic repository and other disposal concepts, and transportation processes for nuclear fuel, LLW, SNF, transuranic, and high-level waste.

D. E. Shropshire; K. A. Williams; W. B. Boore; J. D. Smith; B. W. Dixon; M. Dunzik-Gougar; R. D. Adams; D. Gombert; E. Schneider

2008-03-01T23:59:59.000Z

471

Advanced Fuel Cycle Cost Basis  

SciTech Connect

This report, commissioned by the U.S. Department of Energy (DOE), provides a comprehensive set of cost data supporting a cost analysis for the relative economic comparison of options for use in the Advanced Fuel Cycle Initiative (AFCI) Program. The report describes the AFCI cost basis development process, reference information on AFCI cost modules, a procedure for estimating fuel cycle costs, economic evaluation guidelines, and a discussion on the integration of cost data into economic computer models. This report contains reference cost data for 26 cost modules—24 fuel cycle cost modules and 2 reactor modules. The cost modules were developed in the areas of natural uranium mining and milling, conversion, enrichment, depleted uranium disposition, fuel fabrication, interim spent fuel storage, reprocessing, waste conditioning, spent nuclear fuel (SNF) packaging, long-term monitored retrievable storage, near surface disposal of low-level waste (LLW), geologic repository and other disposal concepts, and transportation processes for nuclear fuel, LLW, SNF, and high-level waste.

D. E. Shropshire; K. A. Williams; W. B. Boore; J. D. Smith; B. W. Dixon; M. Dunzik-Gougar; R. D. Adams; D. Gombert

2007-04-01T23:59:59.000Z

472

Advanced Fuel Cycle Cost Basis  

SciTech Connect

This report, commissioned by the U.S. Department of Energy (DOE), provides a comprehensive set of cost data supporting a cost analysis for the relative economic comparison of options for use in the Advanced Fuel Cycle Initiative (AFCI) Program. The report describes the AFCI cost basis development process, reference information on AFCI cost modules, a procedure for estimating fuel cycle costs, economic evaluation guidelines, and a discussion on the integration of cost data into economic computer models. This report contains reference cost data for 25 cost modules—23 fuel cycle cost modules and 2 reactor modules. The cost modules were developed in the areas of natural uranium mining and milling, conversion, enrichment, depleted uranium disposition, fuel fabrication, interim spent fuel storage, reprocessing, waste conditioning, spent nuclear fuel (SNF) packaging, long-term monitored retrievable storage, near surface disposal of low-level waste (LLW), geologic repository and other disposal concepts, and transportation processes for nuclear fuel, LLW, SNF, transuranic, and high-level waste.

D. E. Shropshire; K. A. Williams; W. B. Boore; J. D. Smith; B. W. Dixon; M. Dunzik-Gougar; R. D. Adams; D. Gombert; E. Schneider

2009-12-01T23:59:59.000Z

473

Combined-cycle power tower  

DOE Green Energy (OSTI)

This paper evaluates a new power tower concept that offers significant benefits for commercialization of power tower technology. The concept uses a molten nitrate salt centralreceiver plant to supply heat, in the form of combustion air preheat, to a conventional combined-cycle power plant. The evaluation focused on first commercial plants, examined three plant capacities (31, 100, and 300 MWe), and compared these plants with a solar-only 100-MWe plant and with gas-only combined-cycle plants in the same three capacities. Results of the analysis point to several benefits relative to the solar-only plant including low energy cost for first plants, low capital cost for first plants, reduced risk with respect to business uncertainties, and the potential for new markets. In addition, the concept appears to have minimal technology development requirements. Significantly, the results show that it is possible to build a first plant with this concept that can compete with existing gas-only combined-cycle plants.

Bohn, M.S.; Williams, T.A.; Price, H.W.

1994-10-01T23:59:59.000Z

474

Initial acquisition performance of the multiple receive antenna assisted DS-UWB downlink using search space reduction and iterative code phase estimation  

Science Conference Proceedings (OSTI)

In this paper we propose and investigate an iterative code acquisition scheme assisted by both Search Space Reduction (SSR) and iterative Message Passing (MP), which was designed for the multiple receive antenna assisted Direct Sequence-Ultra WideBand ... Keywords: direct sequence-ultra wideBand (DS-UWB), initial acquisition, mean acquisition time (MAT), message passing (MP), search space reduction (SSR)

SeungHwan Won; Lajos Hanzo

2009-01-01T23:59:59.000Z

475

Experimental implementation of active force control and iterative learning technique to a two-link arm driven by penumatic artificial muscles  

Science Conference Proceedings (OSTI)

This paper highlights the practical viability and feasibility of an active force control (AFC) technique incorporating an iterative learning (IL) algorithm known as AFCAIL applied to a two-link planar arm actuated by a pair of pneumatic artificial muscles ... Keywords: active force control, hardware-in-the-loop simulation, iterative learning, pneumatic artificial muscle

M. Mailah; H. H. Mun; S. Kazi; H. Jahanabadi

2011-12-01T23:59:59.000Z

476

Toward single-cycle optical pulses  

E-Print Network (OSTI)

Single-cycle optical pulses, the never-before-achieved regime, have a great potential for attos