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1

The ITER tritium systems  

Microsoft Academic Search

ITER is the first fusion machine fully designed for operation with equimolar deuterium–tritium mixtures. The tokamak vessel will be fuelled through gas puffing and pellet injection, and the Neutral Beam heating system will introduce deuterium into the machine. Employing deuterium and tritium as fusion fuel will cause alpha heating of the plasma and will eventually provide energy. Due to the

M. Glugla; A. Antipenkov; S. Beloglazov; C. Caldwell-Nichols; I. R. Cristescu; C. Day; L. Doerr; J.-P. Girard; E. Tada

2007-01-01

2

MELCOR 1.8.2 Analyses in Support of ITER’s RPrS  

SciTech Connect

The International Thermonuclear Experimental Reactor (ITER) Program is performing accident analyses for ITER’s “Rapport Préliminaire de Sûreté” (Report Preliminary on Safety - RPrS) with a modified version of the MELCOR 1.8.2 code. The RPrS is an ITER safety document required in the ITER licensing process to obtain a “Décret Autorisation de Construction” (a Decree Authorizing Construction - DAC) for the ITER device. This report documents the accident analyses performed by the US with the MELCOR 1.8.2 code in support of the ITER RPrS effort. This work was funded through an ITER Task Agreement for MELCOR Quality Assurance and Safety Analyses. Under this agreement, the US was tasked with performing analyses for three accident scenarios in the ITER facility. Contained within the text of this report are discussions that identify the cause of these accidents, descriptions of how these accidents are likely to proceed, the method used to analyze the consequences of these accidents, and discussions of the transient thermal hydraulic and radiological release results for these accidents.

Brad J Merrill

2008-01-01

3

ITER system study---Safety aspects  

Microsoft Academic Search

One of the tasks of the ITER Systems Analysis Group has been safety and environmental analyses. The safety analyses show that radiological doses from operational effluents and accidents are consistent with anticipated regulatory dose limits. To improve safety further and to meet the ambitious goal of passive safety,'' further efforts to reduce inventories of tritium and activation products are proposed.

S. J. Piet; H. Iida; Y. Seki; J. Raeder; L. N. Topilski

1990-01-01

4

ECRH System For ITER  

NASA Astrophysics Data System (ADS)

A 26 MW Electron Cyclotron Heating and Current Drive (EC H&CD) system is to be installed for ITER. The main objectives are to provide, start-up assist, central H&CD and control of MHD activity. These are achieved by a combination of two types of launchers, one located in an equatorial port and the second type in four upper ports. The physics applications are partitioned between the two launchers, based on the deposition location and driven current profiles. The equatorial launcher (EL) will access from the plasma axis to mid radius with a relatively broad profile useful for central heating and current drive applications, while the upper launchers (ULs) will access roughly the outer half of the plasma radius with a very narrow peaked profile for the control of the Neoclassical Tearing Modes (NTM) and sawtooth oscillations. The EC power can be switched between launchers on a time scale as needed by the immediate physics requirements. A revision of all injection angles of all launchers is under consideration for increased EC physics capabilities while relaxing the engineering constraints of both the EL and ULs. A series of design reviews are being planned with the five parties (EU, IN, JA, RF, US) procuring the EC system, the EC community and ITER Organization (IO). The review meetings qualify the design and provide an environment for enhancing performances while reducing costs, simplifying interfaces, predicting technology upgrades and commercial availability. In parallel, the test programs for critical components are being supported by IO and performed by the Domestic Agencies (DAs) for minimizing risks. The wide participation of the DAs provides a broad representation from the EC community, with the aim of collecting all expertise in guiding the EC system optimization. Still a strong relationship between IO and the DA is essential for optimizing the design of the EC system and for the installation and commissioning of all ex-vessel components when several teams from several DAs will be involved together in the tests on the ITER site.

Darbos, C.; Henderson, M.; Albajar, F.; Bigelow, T.; Bomcelli, T.; Chavan, R.; Denisov, G.; Farina, D.; Gandini, F.; Heidinger, R.; Goodman, T.; Hogge, J. P.; Kajiwara, K.; Kasugai, A.; Kern, S.; Kobayashi, N.; Oda, Y.; Ramponi, G.; Rao, S. L.; Rasmussen, D.; Rzesnicki, T.; Saibene, G.; Sakamoto, K.; Sauter, O.; Scherer, T.; Strauss, D.; Takahashi, K.; Zohm, H.

2009-11-01

5

Radiation shielding analyses for the ECRH launcher in the ITER upper port  

Microsoft Academic Search

Radiation shielding analyses have been performed for the ECRH system in the ITER upper port to complete the neutron streaming analysis performed previously. The analyses aimed at assessing and optimising the performance of the radiation shield to prove that the shielding requirements can be met by the proposed design variants. The radiation transport calculations have been performed by means of

A. Serikov; U. Fischer; R. Heidinger; K. Lang; Y. Luo; H. Tsige-Tamirat

2005-01-01

6

Electromagnetic Analyses of ITER Lower ELM Right Bottom Corner  

NASA Astrophysics Data System (ADS)

ELM (edge localized mode) coils are key components of ITER that suppress the edge localized mode phenomenon. A giant electromagnetic force is generated during normal operations by the current flowing in the ELM coils interacting with the external background field. The Lorentz force will induce Tresca stress in the ELM coils. If the load goes beyond the allowable threshold, the coils can hardly satisfy the safety requirements. The right-hand bottom corner was chosen to perform our electromagnetic analyses. Based on the Maxwell equation, the detailed magnetic field and Lorentz force were calculated. By use of the finite element software ANSYS, the Tresca stress was extracted and evaluated based on our analytical design. The present analysis aims to verify the feasibility of the current design. It can also serve as guidance for fabrication and structural optimization.

Wang, Xianwei; Xie, Fei; Jin, Huan

2014-08-01

7

ANALYSES AND PRELIMINARY RESULTS OF AN UPDATED ITER RADIOACTIVE WASTE ASSESSMENT  

E-print Network

ANALYSES AND PRELIMINARY RESULTS OF AN UPDATED ITER RADIOACTIVE WASTE ASSESSMENT S. ZHENG,a * R aimed at updating the ITER radioactive inventory assessment and assisting the waste manage- ment operations, and waste management processes and services. KEYWORDS: ITER, radioactive waste management

8

ITER HEAT REMOVAL SYSTEM SYSTEM & PROCESS CONTROL DESIGN  

E-print Network

ITER HEAT REMOVAL SYSTEM SYSTEM & PROCESS CONTROL DESIGN Y. Hoshi 1 , Y. Kataoka 2 , V. Tanchuk 1, Germany; 4 EU Home Team, Garching, Germany; 5 JA Home Team, Naka, Japan The paper reports ITER heat normal pulse operation. 1. INTRODUCTION ITER heat removal systems are mainly composed of vacuum vessel

Raffray, A. René

9

Verification of MELCOR Input Decks Used in ITER RPrS Analyses  

SciTech Connect

This report as part of an ITER Task Agreement, documents the verification of the MELCOR Input Computer Decks used in performing the required safety analyses to be presented in the Preliminary Safety Report (Rapport Préliminaire de Séreté, RPrS).

Richard L. Moore

2008-01-01

10

Assessment of CONTAIN and MELCOR for performing LOCA and LOVA analyses in ITER  

SciTech Connect

This report describes the results of an assessment of the CONTAIN and MELCOR computer codes for ITER LOCA and LOVA applications. As part of the assessment, the results of running a test problem that describes an ITER LOCA are presented. It is concluded that the MELCOR code should be the preferred code for ITER severe accident thermal hydraulic analyses. This code will require the least modification to be appropriate for calculating thermal hydraulic behavior in ITER relevant conditions that include vacuum, cryogenics, ITER temperatures, and the presence of a liquid metal test module. The assessment of the aerosol transport models in these codes concludes that several modifications would have to be made to CONTAIN and/or MELCOR to make them applicable to the aerosol transport part of severe accident analysis in ITER.

Merrill, B.J.; Hagrman, D.L.; Gaeta, M.J.; Petti, D.A.

1994-09-01

11

Analyses of loss of vacuum accident (LOVA) in ITER  

Microsoft Academic Search

A loss of vacuum accident (LOVA) is a unique event in fusion reactors. A reference event for ITER was postulated which was a failure of a penetration line (0.02 m2 cross-section) into a room with stack ventilation. Behavior of ingress air and environmental release of the inventory were calculated by an accident analysis code (MELCOR). No in-vessel component cooling was

T. Honda; H.-W. Bartels; B. Merrill; T. Inabe; D. Petti; R. Moore; T. Okazaki

2000-01-01

12

The ITER Power And Particle Control System  

Microsoft Academic Search

The ITER power and particle control system is designed to exhaust the 300 to 400 MW of alpha and auxiliary heating power and the He ash created by the fusion reactions, to control the density, and to fuel the plasma. The power and particle control system consists of a single null poloidal divertor, a set of active pumps with a

D. Post; T. Ando; A. Antipenkov; S. Chiocchio; J. Dietz; G. Federici; M. Gouge; Y. Igitkhanov; G. Janeschitz; C. Karney; A. Kukushkin; P. Ladd; J. Mandrekas; E. Martin; D. Mitin; H. Nakamura; H. Pacher; R. Parker; W. Stacey; M. Sugihara; R. Tivey

1996-01-01

13

Nuclear modules of ITER tokamak systems code  

SciTech Connect

Nuclear modules were developed to model various reactor components in the ITER systems code. Several design options and cost algorithms are included for each component. The first wall, blanket and shield modules calculate the beryllium zone thickness, the disruptions results, the nuclear responses in different components including the toroidal field coils. Tungsten shield/water coolant/steel structure and steel shield/water coolant are the shield options for the inboard and outboard sections of the reactor. Lithium nitrate dissolved in the water coolant with a variable beryllium zone thickness in the outboard section of the reactor provides the tritium breeding capability. The reactor vault module defines the thickness of the reactor wall and the roof based on the dose equivalent during operation including skyshine contribution. The impurity control module provides the design parameters for the divertor including plate design, heat load, erosion rate, tritium permeation through the plate material to the coolant, plasma contamination by sputtered impurities, and plate lifetime. Several materials: Be, C, V, Mo, and W can be used for the divertor plate to cover a range of plasma edge temperatures. The tritium module calculates tritium and deuterium flow rates for the reactor plant. The tritium inventory in the fuelers, neutral beams, vacuum pumps, impurity control, first wall, and blanket is calculated. Tritium requirements are provided for different operating conditions. The nuclear models are summarized in this paper including the different design options and key analyses of each module. 39 refs., 3 tabs.

Gohar, Y.; Baker, C.; Brooks, J.; Finn, P.; Hassanein, A.; Willms, S.; Barr, W.; Bushigin, A.; Kalyanam, K.M.; Haines, J.

1987-10-01

14

ITER prototype fast plant system controller  

Microsoft Academic Search

ITER CODAC Design identified the need for slow and fast control plant systems, based respectively on industrial automation technology with maximum sampling rates below 100Hz, and on embedded technology with higher sampling rates and more stringent real-time requirements. The fast system is applicable to diagnostics and plant systems in closed-control loops whose cycle times are below 1ms. Fast controllers will

B. Gonçalves; J. Sousa; B. B. Carvalho; A. P. Rodrigues; M. Correia; A. Batista; J. Vega; M. Ruiz; J. M. López; R. Castro; A. Wallander; N. Utzel; P. Makijarvi; S. Simrock; A. Neto; D. Alves; D. F. Valcárcel; P. Lousã; F. Piedade; L. Fernandes

2011-01-01

15

Self-Stabilization in Iteration Systems Howard E. Motteler  

E-print Network

Self-Stabilization in Iteration Systems Howard E. Motteler Research Assocociate Professor Maryland. Such a system is self stabilizing if it is guaranteed to converge to a desirable state or set of states in a #12 of the iteration system model are related. Keywords: iteration system, convergence, self-stabilization 1 #12; 1

Motteler, Howard E.

16

System structure rendering iterative learning convergent  

Microsoft Academic Search

This paper attempts to give a mathematical and physical interpretation of practice-based learning (so-called “iterative learning control”) from the viewpoint of input-output “passivity” of system dynamics. It is shown from an axiomatic argument that the passivity and dissipativity of a pair of input and output for a class of linear dynamical systems with positive real or strictly positive real transfer

Suguru Arimoto; S. Kawamura; Hyun-Yong Han

1998-01-01

17

Neutronics and thermal design analyses of US solid breeder blanket for ITER  

SciTech Connect

The US Solid Breeder Blanket is designed to produce the necessary tritium required for the ITER operation and to operate at power reactor conditions as much as possible. Safety, low tritium inventory, reliability, flexibility cost, and minimum R D requirements are the other design criteria. To satisfy these criteria, the produced tritium is recovered continuously during operation and the blanket coolant operates at low pressure. Beryllium multiplier material is used to control the solid-breeder temperature. Neutronics and thermal design analyses were performed in an integrated manner to define the blanket configuration. The reference parameters of ITER including the operating scenarios, the neutron wall loading distribution and the copper stabilizer are included in the design analyses. Several analyses were performed to study the impact of the reactor parameters, blanket dimensions, material characteristics, and heat transfer coefficient at the material interfaces on the blanket performance. The design analyses and the results from the different studies are summarized. 6 refs., 3 figs., 3 tabs.

Gohar, Y.; Billone, M.; Attaya, H. (Argonne National Lab., IL (USA)); Sawan, M. (Wisconsin Univ., Madison, WI (USA))

1990-09-01

18

Radiation shield analyses in support of the FS design for the ITER ECRH launcher  

Microsoft Academic Search

This paper is devoted to the radiation shield analyses for the front steering (FS) design of the electron cyclotron resonance heating (ECRH) launcher installed in the ITER upper port. The neutron fluxes, nuclear heat density, helium production, and neutron displacements rate have been calculated by Monte Carlo N-Particle (MCNP) transport code. Three-dimensional MCNP models of the FS ECRH launcher have

A. Serikov; U. Fischer; R. Heidinger; M. A. Henderson; P. Spaeh; H. Tsige-Tamirat

2007-01-01

19

Nuclear modules of ITER tokamak systems code  

Microsoft Academic Search

Nuclear modules were developed to model various reactor components in the ITER systems code. Several design options and cost algorithms are included for each component. The first wall, blanket and shield modules calculate the beryllium zone thickness, the disruptions results, the nuclear responses in different components including the toroidal field coils. Tungsten shield\\/water coolant\\/steel structure and steel shield\\/water coolant are

Y. Gohar; C. Baker; J. Brooks; P. Finn; A. Hassanein; S. Willms; W. Barr; A. Bushigin; K. M. Kalyanam; J. Haines

1987-01-01

20

Power Domains and Iterated Function Systems  

Microsoft Academic Search

We introduce the notion of weakly hyperbolic iterated function system(IFS) on a compact metric space, which generalises that of hyperbolicIFS. Based on a domain-theoretic model, which uses the Plotkin powerdomain and the probabilistic power domain respectively, we prove theexistence and uniqueness of the attractor of a weakly hyperbolic IFSand the invariant measure of a weakly hyperbolic IFS with probabilities,extending the

Abbas Edalat

1996-01-01

21

Analysing Java System Properties Implementation  

E-print Network

Analysing Java System Properties Implementation Supplementary documentation to the Bachelor. It introduces the Java Platform Debugger Architecture (JPDA), looks at the Java Debug Interface (JDI;Analysing Java System Properties Contents David Wettstein, 8. Dezember 2013 3 Contents 1 Standard System

Nierstrasz, Oscar

22

Modified blanket cooling manifold system for ITER  

Microsoft Academic Search

The modular ITER shielding blanket is the innermost part of the reactor directly exposed to the plasma. Its high thermal and nuclear loaded blanket modules (BMs) are water-cooled components. The cooling water is supplied to the BMs by a set of stiff inlet and outlet manifolds mechanically attached to the inner wall of vacuum vessel (VV). The ITER reference design

A. Furmanek; P. Lorenzetto; C. Damiani

2009-01-01

23

Convergence Results on Iteration Algorithms to Linear Systems  

PubMed Central

In order to solve the large scale linear systems, backward and Jacobi iteration algorithms are employed. The convergence is the most important issue. In this paper, a unified backward iterative matrix is proposed. It shows that some well-known iterative algorithms can be deduced with it. The most important result is that the convergence results have been proved. Firstly, the spectral radius of the Jacobi iterative matrix is positive and the one of backward iterative matrix is strongly positive (lager than a positive constant). Secondly, the mentioned two iterations have the same convergence results (convergence or divergence simultaneously). Finally, some numerical experiments show that the proposed algorithms are correct and have the merit of backward methods. PMID:24991640

Wang, Zhuande; Yang, Chuansheng; Yuan, Yubo

2014-01-01

24

ITER  

SciTech Connect

This year six international partners have signed up to construct the first burning plasma experiment -- ITER -- in the South of France.It is over 50 years since the beginning of national programs to produce controlled fusion energy. The challenge of fusion energy has proven harder than was first anticipated. In this Colloquium Steve Cowley from UCLA will explain the scientific issues and how the difficulties have been overcome.

Cowley, Steve

2005-10-10

25

Annual Report of the EURATOM/CCFE Fusion Programme 2009/10 8 ITER Systems  

E-print Network

Annual Report of the EURATOM/CCFE Fusion Programme 2009/10 8.1 8 ITER Systems 8 ITER Systems 8 contributions `in kind' to ITER. As reported in previous Annual Reports, CCFE has been pursuing work on ITER;Annual Report of the EURATOM/CCFE Fusion Programme 2009/10 8.2 8 ITER Systems lose their energy

26

Thermo-mechanical analyses of ITER in-vessel magnetic sensor assembly  

NASA Astrophysics Data System (ADS)

This paper summarizes the work concerning design studies of the ITER in-vessel discrete magnetic sensor assemblies, with particular emphasis on the thermal behaviour of the Low Temperature Co-fired Ceramic (LTCC) magnetic sensor and on the thermo-mechanical aspects of the interface with the Vacuum Vessel (VV). The paper summarises the results of FEM thermal analyses performed on the LTCC sensor head and on the sensor assembly to assess the temperature distribution during operating conditions, which could affect the sensor signal due to Temperature-Induced Electromotive Force effect. The paper then concentrates on mechanical analysis of the Base-Plate to assess that the stress and deformation due to the welding to the VV are acceptable to guarantee a sound installation and a suitable thermal contact of the sensor assembly to the VV.

Gonzalez, W.; Arshad, S.; Peruzzo, S.; Portales, M.; Rizzolo, A.; Vayakis, G.

2014-08-01

27

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.

1988-12-01

28

Performance and capacity analysis of Poisson photon-counting based Iter-PIC OCDMA systems.  

PubMed

In this paper, an iterative parallel interference cancellation (Iter-PIC) technique is developed for optical code-division multiple-access (OCDMA) systems relying on shot-noise limited Poisson photon-counting reception. The novel semi-analytical tool of extrinsic information transfer (EXIT) charts is used for analysing both the bit error rate (BER) performance as well as the channel capacity of these systems and the results are verified by Monte Carlo simulations. The proposed Iter-PIC OCDMA system is capable of achieving two orders of magnitude BER improvements and a 0.1 nats of capacity improvement over the conventional chip-level OCDMA systems at a coding rate of 1/10. PMID:24216821

Li, Lingbin; Zhou, Xiaolin; Zhang, Rong; Zhang, Dingchen; Hanzo, Lajos

2013-11-01

29

Engineering design of ITER prototype Fast Plant System Controller  

Microsoft Academic Search

ITER CODAC Design identified the need for two types of Plant System. Slow control plant system, based on industrial automation technology with maximum sampling rates below 100 Hz, and fast control plant system based on embedded technology with higher sampling rates and more stringent realtime requirements. The latter is applicable to diagnostics and Plant Systems in closed-control loops whose cycle

B. Gonçalves; J. Sousa; B. Carvalho; A. P. Rodrigues; M. Correia; A. Batista; J. Vega; M. Ruiz; J. M. Lo?pez; R. C. Rojo; A. Wallander; N. Utzel; A. Neto; D. Alves; D. Valca?rcel

2010-01-01

30

Annual Report of the EURATOM/CCFE Fusion Programme 2013 8 ITER SYSTEMS  

E-print Network

Annual Report of the EURATOM/CCFE Fusion Programme 2013 8.1 8 ITER SYSTEMS 8 ITER SYSTEMS 8.1 OVERVIEW As reported in previous Annual Reports, CCFE has continued to pursue work on ITER in a number completed. 8ITERSYSTEMS #12;Annual Report of the EURATOM/CCFE Fusion Programme 2013 8.2 8 ITER SYSTEMS

31

Engineering Design of ITER Prototype Fast Plant System Controller  

Microsoft Academic Search

The ITER control, data access and communication (CODAC) design team identified the need for two types of plant systems. A slow control plant system is based on industrial au- tomation technology with maximum sampling rates below 100 Hz, and a fast control plant system is based on embedded technology with higher sampling rates and more stringent real-time require- ments than

B. Goncalves; J. Sousa; B. Carvalho; A. P. Rodrigues; M. Correia; A. Batista; J. Vega; M. Ruiz; J. M. Lopez; R. Castro Rojo; A. Wallander; N. Utzel; A. Neto; D. Alves; D. Valcarcel

2011-01-01

32

Status of research toward the ITER disruption mitigation system  

NASA Astrophysics Data System (ADS)

An overview of the present status of research toward the final design of the ITER disruption mitigation system (DMS) is given. The ITER DMS is based on massive injection of impurities, in order to radiate the plasma stored energy and mitigate the potentially damaging effects of disruptions. The design of this system will be extremely challenging due to many physics and engineering constraints such as limitations on port access and the amount and species of injected impurities. Additionally, many physics questions relevant to the design of the ITER disruption mitigation system remain unsolved such as the mechanisms for mixing and assimilation of injected impurities during the rapid shutdown and the mechanisms for the subsequent formation and dissipation of runaway electron current.

Hollmann, E. M.; Aleynikov, P. B.; Fülöp, T.; Humphreys, D. A.; Izzo, V. A.; Lehnen, M.; Lukash, V. E.; Papp, G.; Pautasso, G.; Saint-Laurent, F.; Snipes, J. A.

2015-02-01

33

Design of fast tuning elements for the ITER ICH system  

SciTech Connect

The coupling between the ion cyclotron (IC) antenna and the ITER plasma (as expressed by the load resistance the antenna sees) will experience relatively fast variations due to plasma edge profile modifications. If uncompensated, these will cause an increase in the amount of power reflected back to the transmitter and ultimately a decrease in the amount of radio frequency (rf) power to the plasma caused by protective suppression of the amount of rf power generated by the transmitter. The goals of this task were to study several alternate designs for a tuning and matching (T&M) system and to recommend some research and development (R&D) tasks that could be carried out to test some of the most promising concepts. Analyses of five different T&M configurations are presented in this report. They each have different advantages and disadvantages, and the choice among them must be made depending on the requirements for the IC system. Several general conclusions emerge from our study: The use of a hybrid splitter as a passive reflected-power dump [``edge localized mode (ELM)-dump``] appears very promising; this configuration will protect the rf power sources from reflected power during changes in plasma loading due to plasma motion or profile changes (e.g., ELM- induced changes in the plasma scrape-off region) and requires no active control of the rf system. Trade-offs between simplicity of design and capability of the system must be made. Simple system designs with few components near the antenna either have high voltages over considerable distances of transmission lines, or they are not easily tuned to operate at different frequencies. Designs using frequency shifts and/or fast tuning elements can provide fast matching over a wide range of plasma loading; however, the designs studied here require components near the antenna, complicating assembly and maintenance. Capacitor-tuned resonant systems may offer a good compromise.

Swain, D.W.; Goulding, R.H.

1996-05-01

34

Multilevel iteration for mixed finite element systems with penalty  

Microsoft Academic Search

In this paper, the authors consider the solution of the discrete systems that arises when a mixed finite element approach is used to approximate the solution of second-order elliptic boundary value problems. By the introduction of a penalty parameter, these equations can be approximated by the solution of a symmetric and positive definite penalty system on the velocity subspace. Iterative

Zhiqiang Cai; Charles I. Goldstein; Joseph E. Pasciak

1993-01-01

35

Tritium module for ITER\\/TIBER system code  

Microsoft Academic Search

A tritium module was developed for the ITER\\/TIBER system code to provide information on capital costs, tritium inventory, power requirements, and building volumes for these systems. In the tritium module, the main tritium subsystems - plasma processing, atmospheric cleanup, water cleanup, blanket processing - are each represented.

P. A. Finn; A. Busigin; K. M. Kalyanam

1988-01-01

36

Tritium module for ITER/Tiber system code  

SciTech Connect

A tritium module was developed for the ITER/Tiber system code to provide information on capital costs, tritium inventory, power requirements and building volumes for these systems. In the tritium module, the main tritium subsystems/emdash/plasma processing, atmospheric cleanup, water cleanup, blanket processing/emdash/are each represented by simple scaleable algorithms. 6 refs., 2 tabs.

Finn, P.A.; Willms, S.; Busigin, A.; Kalyanam, K.M.

1988-01-01

37

Tritium module for ITER\\/Tiber system code  

Microsoft Academic Search

A tritium module was developed for the ITER\\/Tiber system code to provide information on capital costs, tritium inventory, power requirements and building volumes for these systems. In the tritium module, the main tritium subsystems\\/emdash\\/plasma processing, atmospheric cleanup, water cleanup, blanket processing\\/emdash\\/are each represented by simple scaleable algorithms. 6 refs., 2 tabs.

P. A. Finn; S. Willms; A. Busigin; K. M. Kalyanam

1988-01-01

38

Contrast enhancement of images using Partitioned Iterated Function Systems  

Microsoft Academic Search

A new algorithm for the contrast enhancement of images, based on the theory of Partitioned Iterated Function System (PIFS), is presented. A PIFS consists of contractive transformations, such that the original image is the fixed point of the union of these transformations. Each transformation involves the contractive affine spatial transform of a square block, as well as the linear transform

Theodore Economopoulos; Pantelis A. Asvestas; George K. Matsopoulos

2010-01-01

39

Initial results of systems analysis ETR\\/ITER design space  

Microsoft Academic Search

Preliminary versions of the Engineering Test REactor (ETR) systems code TETRA (Tokamak Engineering Test Reactor Analysis), which determines design solutions by the method of constrained optimization, are used to characterize the International Thermonuclear Experimental Reactor (ITER) and its design parameter space. They find that the physics objectives of high ignition margin and high plasma current lead to minimum size at

Yueng Kay Martin Peng; John D Galambos; R. L. Reid; Dennis J Strickler

1987-01-01

40

Iterative algorithms for large sparse linear systems on parallel computers  

NASA Technical Reports Server (NTRS)

Algorithms for assembling in parallel the sparse system of linear equations that result from finite difference or finite element discretizations of elliptic partial differential equations, such as those that arise in structural engineering are developed. Parallel linear stationary iterative algorithms and parallel preconditioned conjugate gradient algorithms are developed for solving these systems. In addition, a model for comparing parallel algorithms on array architectures is developed and results of this model for the algorithms are given.

Adams, L. M.

1982-01-01

41

Linear prediction image coding using iterated function systems  

Microsoft Academic Search

This paper presents a hybrid system to speed up image fractal encoding. The coding scheme, LP-IFS, consists of linear prediction (LP) and Iterated Functions Systems (IFS) applied in cascade on the image. The LP process employs a 2D auto-regressive model to estimate parameters for each block in the image partition; IFS are then used instead of adaptive quantizers to encode

Michele Nappi; Domenico Vitulano

1999-01-01

42

Current drive and heating systems for an ITER HARD option  

SciTech Connect

A conceptual design has been developed for a reference current drive and heating system for a HARD (High Aspect Ratio Design) option for ITER. Twelve neutral beam modules, each rated at 1.3MeV and 9.2MW, perform plasma heating and current drive. An electron cyclotron system is used for initiating the plasma and for disruption control. An alternate system has been defined which is comprised of a lower hybrid and ion cyclotron system for heating and current drive, augmented by the same electron cyclotron system proposed for the reference system. 7 refs., 8 figs., 1 tab.

Lindquist, W.; Bulmer, R.; Fenstermacher, M.; Nevins, W.; Parker, J.; Smith, G.; Wendland, C.; Williamson, V. (Lawrence Livermore National Lab., CA (United States)); Copper, W.; Wells, R. (Lawrence Berkeley Lab., CA (United States))

1991-09-25

43

Aviation System Analysis Capability Executive Assistant Analyses  

NASA Technical Reports Server (NTRS)

This document describes the analyses that may be incorporated into the Aviation System Analysis Capability Executive Assistant. The document will be used as a discussion tool to enable NASA and other integrated aviation system entities to evaluate, discuss, and prioritize analyses.

Roberts, Eileen; Kostiuk, Peter

1999-01-01

44

Contrast Enhancement of Images Using Partitioned Iterated Function Systems  

Microsoft Academic Search

A new algorithm for the contrast enhancement of images, based on the theory of Partitioned Iterated Function System (PIFS),\\u000a is presented. A PIFS consists of contractive transformations, such that the original image is the fixed point of the union\\u000a of these transformations. Each transformation involves the contractive affine spatial transform of a square block, as well\\u000a as the linear transform

Theodore Economopoulos; Pantelis Asvestas; George K. Matsopoulos

2007-01-01

45

ITER prototype fast plant system controller based on ATCA platform  

Microsoft Academic Search

The ITER Fast Plant System Controllers (FPSC) are based on embedded technologies and will be devoted to both data acquisition tasks (sampling rates >1 kSPS) and control purposes in closed-control loops whose cycle times are below 1 ms. Fast Controllers will be dedicated industrial controllers with the ability to: i) supervise other fast and\\/or slow controllers; ii) interface to actuators

B. Goncalves; J. Sousa; B. B. Carvalho; A. Batista; A. Neto; B. Santos; A. Duarte; D. Valcarcel; D. Alves; M. Correia; A. P. Rodrigues; P. F. Carvalho; J. Fortunato; P. J. Carvalho; M. Ruiz; J. Vega; R. Castro; J. M. Lopez; N. Utzel; P. Makijarvi; C. Leong; V. Bexiga; I. C. Teixeira; J. P. Teixeira; A. Barbalace; P. Lousa; J. Godinho; P. Mota

2011-01-01

46

Annual Report of the EURATOM/UKAEA Fusion Programme 2007/08 8 ITER Systems  

E-print Network

Annual Report of the EURATOM/UKAEA Fusion Programme 2007/08 8.1 8 ITER Systems 8 ITER Systems 8 (overall COntrol Data Access and Communication). 8ITERSystems #12;Annual Report of the EURATOM/UKAEA Fusion in some of the EFDA- led R&D for IFMIF, and this is also reported in this chapter. 8.2 ITER DIAGNOSTICS

47

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

E-print Network

Annual Report of the EURATOM/CCFE Fusion Programme 2010/11 8 ITER Systems 8.1 OVERVIEW As reported in previous Annual Reports, CCFE has been pursuing work on ITER in a number of areas of significance associations, 8.1 8 ITER Systems #12;Annual Report of the EURATOM/CCFE Fusion Programme 2010/11 CYCLE, has been

48

Aviation forecasting and systems analyses  

SciTech Connect

The 9 papers in this report deal with the following areas: method of allocating airport runway slots; method for forecasting general aviation activity; air traffic control network-planning model based on second-order Markov chains; analyzing ticket-choice decisions of air travelers; assessing the safety and risk of air traffic control systems: risk estimation from rare events; forecasts of aviation fuel consumption in Virginia; estimating the market share of international air carriers; forecasts of passenger and air-cargo activity at Logan International Airport; and forecasting method for general aviation aircraft and their activity.

Geisinger, K.E.; Brander, J.R.G.; Wilson, F.R.; Kohn, H.M.; Polhemus, N.W.

1980-01-01

49

Neutron flux monitoring system for ITER-FEAT (abstract)  

NASA Astrophysics Data System (ADS)

The concept of the neutron flux measurements for International Thermonuclear Experimental Reactor ITER-FEAT is discussed. In spite of the fact that ITER-FEAT has reduced fusion power with respect to ITER-FDR, the requirements for neutron flux monitors are similar—wide dynamic range (seven orders), good temporal resolution (1 ms), and high accuracy (10%). It is clear that fission chambers are the most suitable detectors for this application. However high neutron intensity of the fusion plasma and hard requirements lead to a more sophisticated detection system than the ordinary fission chamber. Another problem is an absolute calibration of the detectors. We propose a neutron flux monitoring system, which consist of microfission chambers placed inside the ITER vacuum chamber, three wide range fission chambers placed outside the vacuum chamber, natural diamond detector based compact neutron monitors placed inside the channels of the neutron cameras, and a compact neutron generator for calibration. Microfission chambers could be installed in the standard plugs with other detectors (vacuum x-ray diode, magnetic probe). 235U could be used as well as threshold fission materials (238U, 237Np, 232Th). In the last case the fission chamber will be covered by a boron shield to reduce the changes in the sensitivity. Wide range fission chambers will operate in both pulse count mode and Campbell mode. High linearity is provided by count mode. Temporal resolution of 1 ms is provided by the count mode at low neutron flux and by the Campbell mode at high flux. The nonlinearity of the fission chamber during the switch from count mode to Campbell mode will be corrected by another fission chamber with low sensitivity operating in count mode. Compact neutron flux monitors placed inside neutron cameras will consist of up to ten natural diamond neutron counters with sensitivity to DT neutrons doubled by properly installed poliethilen radiators. Such monitors provide DT neutron flux profile measurements with dynamic range (three orders), temporal resolution (1 ms), and accuracy (10%). The full system could be calibrated by compact moveable neutron generator with neutron yield 1011 neutron/s, which operate in continuous mode. All elements of the system are commercially available, except for the neutron generator and diamond detector based monitors. The neutron generator and multidiamond detector based DT neutron monitors are now under development. An existing prototype of the neutron generator operates with a yield of one order less. Performance and major characteristics of the proposed systems of neutron flux monitoring will be discussed from the point of view of their application for neutron flux measurements and control of deuterium and deuterium-tritium phases of the ITER-FEAT operation.

Kaschuck, Yu.; Krasilnikov, A.; Alekseyev, A.; Amosov, V.; Frunze, V.

2001-01-01

50

ITER cryogenic system validation tests at helios test facility  

NASA Astrophysics Data System (ADS)

The ITER cryogenic system will have to cope with substantial dynamic heat loads due to the magnetic field variation and the production of neutrons generated by the fusion reactions. This will induce large pressure variations in the primary cooling loop of the superconducting coils, which results in the large power variation to the helium refrigerator. The HELIOS test facility, developed at CEA-Grenoble, and initially designed to study the pulse mitigation of the JT-60SA central solenoid cooling circuit (in order to smooth the pulsed load and test components), was adapted to the ITER cooling loop requirements. This paper presents the experimental results concerning the specific ITER analysis. We reproduce experimentally the pressure variation of the Central Solenoid (CS) loop predicted by a numerical model, and observe the behaviour of the circulating pump in these conditions. The investigations of the heat load smoothing methods, using the circuit of Toroidal Field Structures, such as the pulse mitigation by temporary by-pass of the flow of the Structure cooling loop, and variation of the speed of the cold circulating pump, are also presented.

Vallcorba-Carbonell, Roser; Rousset, Bernard; Poncet, Jean-Marc; Chang, Hyun-Sik; Forgeas, Adrien; Maekawa, Ryugi; Serio, Luigi; Bonnay, Patrick; Bon-Mardion, Michel; Girard, Alain; Hoa, Christine; Lagier, Benjamin; Michel, Frederic; Roussel, Pascal

2012-06-01

51

Nested Iteration and First-Order System Least Squares for Incompressible, Resistive Magnetohydrodynamics  

Microsoft Academic Search

This paper develops a nested iteration algorithm to solve time-dependent nonlinear systems of partial differential equations. For each time step, Newton's method is used to form approximate solutions from a sequence of nested spaces, where the resolution of the approximations increases as the algorithm progresses. Nested iteration results in most of the iterations being performed on coarser grids, where minimal

J. H. Adler; Thomas A. Manteuffel; Stephen F. McCormick; John Ruge; G. D. Sanders

2010-01-01

52

ITER ICH Transmission Line and Matching System Prototype Development  

NASA Astrophysics Data System (ADS)

Design and testing of prototype components for the ITER Ion Cyclotron Heating (ICH) transmission line and matching system is underway. Each ICH transmission line is designed to handle up to 6 MW/line in the 40-55 MHz frequency range. A total of 8 lines split to 16 antenna inputs on two ICH antennas. The ICH system is made up of 14 types of unique coaxial transmission line and matching components. The matching system is designed to provide passive ELM tolerance through the use of hybrid couplers and loads, which can absorb the transient reflected power. In addition the system is designed to compensate for coupling between antenna inputs caused by the mutual inductances of the current straps. It is further designed to balance as much as reasonable, the power requirements from the sources and the peak voltages on the antenna array elements.

Rasmussen, D. A.; Swain, D. W.; Goulding, R. H.; Pesavento, P. V.; Peters, B.; Fredd, E. H.; Hosea, J.; Greenough, N.

2011-12-01

53

Status of the ITER heating neutral beam system  

NASA Astrophysics Data System (ADS)

The ITER neutral beam (NB) injectors are the first injectors that will have to operate under conditions and constraints similar to those that will be encountered in a fusion reactor. These injectors will have to operate in a hostile radiation environment and they will become highly radioactive due to the neutron flux from ITER. The injectors will use a single large ion source and accelerator that will produce 40 A 1 MeV D- beams for pulse lengths of up to 3600 s. Significant design changes have been made to the ITER heating NB (HNB) injector over the past 4 years. The main changes are: Modifications to allow installation and maintenance of the beamline components with an overhead crane. The beam source vessel shape has been changed and the beam source moved to allow more space for the connections between the 1 MV bushing and the beam source. The RF driven negative ion source has replaced the filamented ion source as the reference design. The ion source and extractor power supplies will be located in an air insulated high voltage (-1 MV) deck located outside the tokamak building instead of inside an SF6 insulated HV deck located above the injector. Introduction of an all metal absolute valve to prevent any tritium in the machine to escape into the NB cell during maintenance. This paper describes the status of the design as of December 2008 including the above mentioned changes. The very important power supply system of the neutral beam injectors is not described in any detail as that merits a paper beyond the competence of the present authors. The R&D required to realize the injectors described in this paper must be carried out on a dedicated neutral beam test facility, which is not described here.

Hemsworth, R.; Decamps, H.; Graceffa, J.; Schunke, B.; Tanaka, M.; Dremel, M.; Tanga, A.; DeEsch, H. P. L.; Geli, F.; Milnes, J.; Inoue, T.; Marcuzzi, D.; Sonato, P.; Zaccaria, P.

2009-04-01

54

Parallel, iterative solution of sparse linear systems: Models and architectures  

NASA Technical Reports Server (NTRS)

A model of a general class of asynchronous, iterative solution methods for linear systems is developed. In the model, the system is solved by creating several cooperating tasks that each compute a portion of the solution vector. A data transfer model predicting both the probability that data must be transferred between two tasks and the amount of data to be transferred is presented. This model is used to derive an execution time model for predicting parallel execution time and an optimal number of tasks given the dimension and sparsity of the coefficient matrix and the costs of computation, synchronization, and communication. The suitability of different parallel architectures for solving randomly sparse linear systems is discussed. Based on the complexity of task scheduling, one parallel architecture, based on a broadcast bus, is presented and analyzed.

Reed, D. A.; Patrick, M. L.

1984-01-01

55

THERMAL DESIGN OF THE ITER VACUUM VESSEL COOLING SYSTEM  

SciTech Connect

RELAP5-3D models of the ITER Vacuum Vessel (VV) Primary Heat Transfer System (PHTS) have been developed. The design of the cooling system is described in detail, and RELAP5 results are presented. Two parallel pump/heat exchanger trains comprise the design one train is for full-power operation and the other is for emergency operation or operation at decay heat levels. All the components are located inside the Tokamak building (a significant change from the original configurations). The results presented include operation at full power, decay heat operation, and baking operation. The RELAP5-3D results confirm that the design can operate satisfactorily during both normal pulsed power operation and decay heat operation. All the temperatures in the coolant and in the different system components are maintained within acceptable operating limits.

Carbajo, Juan J [ORNL] [ORNL; Yoder Jr, Graydon L [ORNL] [ORNL; Kim, Seokho H [ORNL] [ORNL

2010-01-01

56

Iterative development of visual control systems in a research vivarium.  

PubMed

The goal of this study was to test the hypothesis that reintroduction of Continuous Performance Improvement (CPI) methodology, a lean approach to management at Seattle Children's (Hospital, Research Institute, Foundation), would facilitate engagement of vivarium employees in the development and sustainment of a daily management system and a work-in-process board. Such engagement was implemented through reintroduction of aspects of the Toyota Production System. Iterations of a Work-In-Process Board were generated using Shewhart's Plan-Do-Check-Act process improvement cycle. Specific attention was given to the importance of detecting and preventing errors through assessment of the following 5 levels of quality: Level 1, customer inspects; Level 2, company inspects; Level 3, work unit inspects; Level 4, self-inspection; Level 5, mistake proofing. A functioning iteration of a Mouse Cage Work-In-Process Board was eventually established using electronic data entry, an improvement that increased the quality level from 1 to 3 while reducing wasteful steps, handoffs and queues. A visual workplace was realized via a daily management system that included a Work-In-Process Board, a problem solving board and two Heijunka boards. One Heijunka board tracked cage changing as a function of a biological kanban, which was validated via ammonia levels. A 17% reduction in cage changing frequency provided vivarium staff with additional time to support Institute researchers in their mutual goal of advancing cures for pediatric diseases. Cage washing metrics demonstrated an improvement in the flow continuum in which a traditional batch and queue push system was replaced with a supermarket-type pull system. Staff engagement during the improvement process was challenging and is discussed. The collective data indicate that the hypothesis was found to be true. The reintroduction of CPI into daily work in the vivarium is consistent with the 4P Model of the Toyota Way and selected Principles that guide implementation of the Toyota Production System. PMID:24736460

Bassuk, James A; Washington, Ida M

2014-01-01

57

Iterative Development of Visual Control Systems in a Research Vivarium  

PubMed Central

The goal of this study was to test the hypothesis that reintroduction of Continuous Performance Improvement (CPI) methodology, a lean approach to management at Seattle Children’s (Hospital, Research Institute, Foundation), would facilitate engagement of vivarium employees in the development and sustainment of a daily management system and a work-in-process board. Such engagement was implemented through reintroduction of aspects of the Toyota Production System. Iterations of a Work-In-Process Board were generated using Shewhart’s Plan-Do-Check-Act process improvement cycle. Specific attention was given to the importance of detecting and preventing errors through assessment of the following 5 levels of quality: Level 1, customer inspects; Level 2, company inspects; Level 3, work unit inspects; Level 4, self-inspection; Level 5, mistake proofing. A functioning iteration of a Mouse Cage Work-In-Process Board was eventually established using electronic data entry, an improvement that increased the quality level from 1 to 3 while reducing wasteful steps, handoffs and queues. A visual workplace was realized via a daily management system that included a Work-In-Process Board, a problem solving board and two Heijunka boards. One Heijunka board tracked cage changing as a function of a biological kanban, which was validated via ammonia levels. A 17% reduction in cage changing frequency provided vivarium staff with additional time to support Institute researchers in their mutual goal of advancing cures for pediatric diseases. Cage washing metrics demonstrated an improvement in the flow continuum in which a traditional batch and queue push system was replaced with a supermarket-type pull system. Staff engagement during the improvement process was challenging and is discussed. The collective data indicate that the hypothesis was found to be true. The reintroduction of CPI into daily work in the vivarium is consistent with the 4P Model of the Toyota Way and selected Principles that guide implementation of the Toyota Production System. PMID:24736460

Bassuk, James A.; Washington, Ida M.

2014-01-01

58

Numerical Analyses of Electromagnetic Forces on the ITER Blanket Module Shield Block During Major Disruptions  

NASA Astrophysics Data System (ADS)

Electromagnetic (EM) load is one of the key design drivers for the blanket shield block (SB) and other in-vessel components. In this article, an EM analysis method was developed to address the EM force on the SB. The plasma currents, which vary spatially and temporally, are loaded as a filament at each time point. The standard blanket module No.04 (BM04) under major disruption (MD) is selected to perform the analyses. The analyses results are validated by comparing currents on the passive structure. To better understand the effects of cooling channels and slits on the EM force, the case of SB without cooling channel and the case without slits are calculated to make comparisons. The results show that the slits play an important role in controlling the EM load on SB.

Kang, Weishan; Yuan, Tao; Sun, Qian; Wu, Jihong; Chen, Jiming

2014-07-01

59

information and computation 124, 182 197 (1996) Power Domains and Iterated Function Systems  

E-print Network

information and computation 124, 182 197 (1996) Power Domains and Iterated Function Systems Abbas Edalat Department of Computing, Imperial College of Science, Technology and Medicine, 180 Queen's Gate

Edalat, Abbas

60

The cryogenic system for ITER CC superconducting conductor test facility  

NASA Astrophysics Data System (ADS)

This paper describes the cryogenic system of the International Thermonuclear Experimental Reactor (ITER) Correction Coils (CC) test facility, which consists of a 500 W/4.5 K helium refrigerator, a 50 kA superconducting transformer cryostat (STC) and a background field magnet cryostat (BFMC). The 500 W/4.5 K helium refrigerator synchronously produces both the liquid helium (LHe) and supercritical helium (SHe). The background field magnet and the primary coil of the superconducting transformer (PCST) are cooled down by immersing into 4.2 K LHe. The secondary Cable-In-Conduit Conductor (CICC) coil of the superconducting transformer (SCST), superconducting joints and the testing sample of ITER CC are cooled down by forced-flow supercritical helium. During the commissioning experiment, all the superconducting coils were successfully translated into superconducting state. The background field magnet was fully cooled by immersing it into 4.2 K LHe and generated a maximal background magnetic field of 6.96 T; the temperature of transformer coils and current leads was reduced to 4.3 K; the inlet temperature of SHe loop was 5.6 K, which can meet the cooling requirements of CIC-Conductor and joint boxes. It is noted that a novel heat cut-off device for High Temperature Superconducting (HTS) binary current leads was introduced to reduce the heat losses of transformer cryostat.

Peng, Jinqing; Wu, Yu; Liu, Huajun; Shi, Yi; Chen, Jinglin; Ren, Zhibin

2011-01-01

61

Iterative Repair Planning for Spacecraft Operations Using the Aspen System  

NASA Technical Reports Server (NTRS)

This paper describes the Automated Scheduling and Planning Environment (ASPEN). ASPEN encodes complex spacecraft knowledge of operability constraints, flight rules, spacecraft hardware, science experiments and operations procedures to allow for automated generation of low level spacecraft sequences. Using a technique called iterative repair, ASPEN classifies constraint violations (i.e., conflicts) and attempts to repair each by performing a planning or scheduling operation. It must reason about which conflict to resolve first and what repair method to try for the given conflict. ASPEN is currently being utilized in the development of automated planner/scheduler systems for several spacecraft, including the UFO-1 naval communications satellite and the Citizen Explorer (CX1) satellite, as well as for planetary rover operations and antenna ground systems automation. This paper focuses on the algorithm and search strategies employed by ASPEN to resolve spacecraft operations constraints, as well as the data structures for representing these constraints.

Rabideau, G.; Knight, R.; Chien, S.; Fukunaga, A.; Govindjee, A.

2000-01-01

62

Harmonic analysis of iterated function systems with overlap  

NASA Astrophysics Data System (ADS)

An iterated function system (IFS) is a system of contractive mappings ?i:Y?Y, i =1,…,N (finite), where Y is a complete metric space. Every such IFS has a unique (up to scale) equilibrium measure (also called the Hutchinson measure ?), and we study the Hilbert space L2(? ). In this paper we extend previous work on IFSs without overlap. Our method involves systems of operators generalizing the more familiar Cuntz relations from operator algebra theory and from subband filter operators in signal processing. These Cuntz-like operator systems were used in recent papers on wavelet analysis by Baggett, Jorgensen, Merrill, and Packer [Contemp. Math. 345, 11-25 (2004)], where they serve as a first step to generating wavelet bases of Parseval type (alias normalized tight frames), i.e., wavelet bases with redundancy. Similarly, it was shown in work by Dutkay and Jorgensen [Rev. Mat. Iberoam. 22, 131-180 (2006)] that the iterative operator approach works well for generating wavelets on fractals from IFSs without overlap. But so far the more general and more difficult case of essential overlap has resisted previous attempts at a harmonic analysis and explicit basis constructions, in particular. The operators generating the appropriate Cuntz relations are composition operators, e.g., Fi:f?f??i, where (?i) is the given IFS. If the particular IFS is essentially nonoverlapping, it is relatively easy to compute the adjoint operators Si=Fi*, and the Si operators will be isometries in L2(?) with orthogonal ranges. For the case of essential overlap, we can use the extra terms entering in the computation of the operators Fi* as a "measure" of the essential overlap for the particular IFS we study. Here the adjoint operators Fi* refer to the Hilbert space L2(?), where ? is the equilibrium measure ? for the given IFS (?i).

Jorgensen, Palle E. T.; Kornelson, Keri; Shuman, Karen

2007-08-01

63

Dynamic Performance of the ITER Reactive Power Compensation System  

NASA Astrophysics Data System (ADS)

Dynamic performance of a reactive power compensation (RPC) system for the international thermonuclear experimental reactor (ITER) power supply is presented. Static var compensators (SVCs) are adopted to mitigate voltage fluctuation and reduce the reactive power down to a level acceptable for the French/European 400 kV grid. A voltage feedback and load power feedforward controller for SVC is proposed, with the feedforward loop intended to guarantee short response time and the feedback loop ensuring good dynamics and steady characteristics of SVC. A mean filter was chosen to measure the control signals to improve the dynamic response. The dynamic performance of the SVC is verified by simulations using PSCAD/EMTDC codes.

Sheng, Zhicai; Fu, Peng; Xu, Liuwei

2011-10-01

64

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

E-print Network

Annual Report of the EURATOM/CCFE Fusion Programme 2011/12 8 ITER Systems 8.1 OVERVIEW As reported in previous Annual Reports, CCFE has been pursuing work on ITER in a number of areas. The over Systems #12;Annual Report of the EURATOM/CCFE Fusion Programme 2011/12 Figure 8.2: Isometric contours

65

Annual Report of the EURATOM/UKAEA Fusion Programme 2008/09 8 ITER Systems  

E-print Network

Annual Report of the EURATOM/UKAEA Fusion Programme 2008/09 8.1 8 ITER Systems 8 ITER Systems 8, following on from the work for EFDA described in the 2007/08 Annual Report. This work was presented.1 in the Materials chapter of this report. 8ITERSystems #12;Annual Report of the EURATOM/UKAEA Fusion Programme 2008

66

Used Fuel Management System Interface Analyses - 13578  

SciTech Connect

Preliminary system-level analyses of the interfaces between at-reactor used fuel management, consolidated storage facilities, and disposal facilities, along with the development of supporting logistics simulation tools, have been initiated to provide the U.S. Department of Energy (DOE) and other stakeholders with information regarding the various alternatives for managing used nuclear fuel (UNF) generated by the current fleet of light water reactors operating in the United States. An important UNF management system interface consideration is the need for ultimate disposal of UNF assemblies contained in waste packages that are sized to be compatible with different geologic media. Thermal analyses indicate that waste package sizes for the geologic media under consideration by the Used Fuel Disposition Campaign may be significantly smaller than the canisters being used for on-site dry storage by the nuclear utilities. Therefore, at some point along the UNF disposition pathway, there could be a need to repackage fuel assemblies already loaded and being loaded into the dry storage canisters currently in use. The implications of where and when the packaging or repackaging of commercial UNF will occur are key questions being addressed in this evaluation. The analysis demonstrated that thermal considerations will have a major impact on the operation of the system and that acceptance priority, rates, and facility start dates have significant system implications. (authors)

Howard, Robert; Busch, Ingrid [Oak Ridge National Laboratory, P.O. Box 2008, Bldg. 5700, MS-6170, Oak Ridge, TN 37831 (United States)] [Oak Ridge National Laboratory, P.O. Box 2008, Bldg. 5700, MS-6170, Oak Ridge, TN 37831 (United States); Nutt, Mark; Morris, Edgar; Puig, Francesc [Argonne National Laboratory (United States)] [Argonne National Laboratory (United States); Carter, Joe; Delley, Alexcia; Rodwell, Phillip [Savannah River National Laboratory (United States)] [Savannah River National Laboratory (United States); Hardin, Ernest; Kalinina, Elena [Sandia National Laboratories (United States)] [Sandia National Laboratories (United States); Clark, Robert [U.S. Department of Energy (United States)] [U.S. Department of Energy (United States); Cotton, Thomas [Complex Systems Group (United States)] [Complex Systems Group (United States)

2013-07-01

67

NUCLEAR MODULES OF ITER TOKAMAK SYSTEMS CODE* ain CONF-871007--68  

E-print Network

NUCLEAR MODULES OF ITER TOKAMAK SYSTEMS CODE* ain CONF-871007--68 DE88 002884 Y. Gohar, C. Baker, J, or assumes any legal liability or responsi- bility for the accuracy, completeness, or usefulness of any Energy under Contract W-31-109 Eng-38. * · * * · · OF Tli!S CGCL'wEliT ISUNUCLEAR MODULES OF ITER

Harilal, S. S.

68

Tritium safety in the design of the ITER tritium processing systems  

Microsoft Academic Search

The design of the ITER tritium systems must ensure that the public is protected from operational and accidental tritium release and that worker exposures are minimized. The ITER public exposure limits are consistent with international recommendations and the As Low As Reasonably Achievable (ALARA) concept is being implemented. We describe design approaches that will allow us to achieve these objectives.

D. F. Holland; J. E. Koonce; O. K. Kveton; M. Enoeda

1995-01-01

69

On the Number of Rational Iterated Pre-images of the Origin Under Quadratic Dynamical Systems  

Microsoft Academic Search

For a quadratic endomorphism of the affine line defined over the rationals, we consider the problem of bounding the number of rational points that eventually land at the origin after iteration. In the article ``Uniform Bounds on Pre-Images Under Quadratic Dynamical Systems,'' by two of the present authors and five others, it was shown that the number of rational iterated

Xander Faber; Benjamin Hutz; Michael Stoll

2008-01-01

70

Annual Report of the EURATOM/CCFE Fusion Programme 2012/13 8 ITER SYSTEMS  

E-print Network

Annual Report of the EURATOM/CCFE Fusion Programme 2012/13 8 ITER SYSTEMS 8.1 OVERVIEW As reported in previous Annual Reports, CCFE has continued to pursue work on ITER in a number of areas. The over #12;Annual Report of the EURATOM/CCFE Fusion Programme 2012/13 CCFE has continued its substantial role

71

ITPACK 2C: A FORTRAN Package for Solving Large Sparse Linear Systems by Adaptive Accelerated Iterative Methods  

Microsoft Academic Search

ITPACK 2C is a collection of seven FORTRAN subroutines for solving large sparse linear systems by adaptive accelerated iterative algorithms. Basic iterative procedures, such as the Jacobi method, the Successive Overrelaxation method, the Symmetric Suc- cessive Overrelaxation method, and the RS method for the reduced system are com- bined, where possible, with acceleration procedures such as Chebyshev (Semi-Iteration) and Conjugate

David R. Kincaid; John R. Respess; David M. Young; Roger G. Grimes

1996-01-01

72

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)

2012-10-15

73

Iterative Methods for Systems' Solving - a C# approach  

E-print Network

This work wishes to support various mathematical issues concerning the iterative methods with the help of new programming languages. We consider a way to show how problems in math have an answer by using different academic resources and different thoughts. Here we treat methods like Gauss-Seidel's, Cramer's and Gauss-Jordan's.

Chirilov, Claudiu

2009-01-01

74

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

PubMed

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. PMID:23127013

Joanny, M; Salasca, S; Dapena, M; Cantone, B; Travère, J M; Thellier, C; Fermé, J J; Marot, L; Buravand, O; Perrollaz, G; Zeile, C

2012-10-01

75

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

NASA Astrophysics Data System (ADS)

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.; Travère, J. M.; Thellier, C.; Fermé, J. J.; Marot, L.; Buravand, O.; Perrollaz, G.; Zeile, C.

2012-10-01

76

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)

2012-10-15

77

Mechanical behavior of the ITER TF model coil ground insulation system after reactor irradiation  

Microsoft Academic Search

The mechanical properties of glass fiber reinforced plastics (GFRPs) suggested for the turn and ground insulation of the ITER toroidal field (TF) coils are subject to extensive investigations with respect to their design requirements at present. The insulation system used for the ITER TF model coil, manufactured by European industry, consists of a boron-free R-glass fiber reinforced tape, vacuum-pressure impregnated

K. Bittner-Rohrhofer; K. Humer; H. Fillunger; R. K. Maix; H. W. Weber

2002-01-01

78

Influence of reactor irradiation on the mechanical behavior of ITER TF coil candidate insulation systems  

Microsoft Academic Search

Extensive material tests have to be performed in order to obtain information on the radiation induced change in the mechanical behavior of insulating materials for the ITER Toroidal Field (TF) coil. The investigated insulation systems are R-glass fiber reinforced tapes, vacuum impregnated with a DGEBA epoxy resin and interleafed with Kapton H-foils. According to the actual operating conditions of ITER–FEAT,

K. Bittner-Rohrhofer; K. Humer; H. Fillunger; R. K. Maix; Z. D. Wang; H. W. Weber

2003-01-01

79

2-D Reflectometer Modeling for Optimizing the ITER Low-field Side Reflectometer System  

SciTech Connect

The response of a low-field side reflectometer system for ITER is simulated with a 2?D reflectometer code using a realistic plasma equilibrium. It is found that the reflected beam will often miss its launch point by as much as 40 cm and that a vertical array of receiving antennas is essential in order to observe a reflection on the low-field side of ITER.

Kramer, G.J.; Nazikian, R.; Valeo, E.J.; Budny, R.V.; Kessel, C.; Johnson, D.

2005-09-02

80

Development of the prototype pneumatic transfer system for ITER neutron activation system.  

PubMed

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. PMID:23126830

Cheon, M S; Seon, C R; Pak, S; Lee, H G; Bertalot, L

2012-10-01

81

Global ICRF system designs for ITER and TPX  

NASA Astrophysics Data System (ADS)

The design of feed networks for ICRF antenna arrays on ITER and TPX are discussed. Features which are present in one or both of the designs include distribution of power to several straps from a single generator, the capability to vary phases of the currents on antenna elements rapidly without the need to rematch, and passive elements which present a nearly constant load to the generators during ELM induced loading transients of a factor of 10 or more. The FDAC (Feedline/Decoupler/Antenna Calculator) network modeling code is described, which allows convenient modeling of the electrical performance of nearly arbitrary ICRF feed networks.

Goulding, R. H.; Hoffman, D. J.; Ryan, P. M.; Durodié, F.

1996-02-01

82

Precision coordination and motion control of multiple systems via iterative learning control  

Microsoft Academic Search

In this paper, we focus on improving the trajectory tracking and formation coordination performance of multiple systems through the use of iterative learning control. A Norm Optimal framework is used to design optimal learning filters based on varying design objectives. The general norm optimal framework is reformatted to enable separate weighting on individual system trajectory tracking, coupled system trajectory tracking,

Kira Barton; Andrew Alleyne

2010-01-01

83

USING ITERATIVE DESIGN AND DEVELOPMENT FOR MOBILE LEARNING SYSTEMS IN SCHOOL PROJECTS  

Microsoft Academic Search

Different approaches have been proposed on the use of digital and interactive technology in mobile learning contexts. In line with recent findings in the literature, we suggest that mobile learning systems benefit from an iterative design and development process within a holistic, socio-technical system view. This system view makes allowance for the complex dynamics between teachers, students, researchers, the multiplicity

André Melzer; Lia Hadley; Marie Glasemann; Simon Werner; Thomas Winkler; Michael Herczeg

84

Iterative Integer Programming Formuation for Robust Resource Allocation in Dynamic Real-Time Systems  

Microsoft Academic Search

Summary form only given. Dynamic real-time systems often operate in a continuously changing environment, causing workload of the system to fluctuate. An initial resource allocation for these systems should be robust with respect to the variation in workload. Using the amount of additional workload that an allocation can accommodate as a measure of robustness, we develop an iterative integer programming

Sethavidh Gertphol; Viktor K. Prasanna

2004-01-01

85

Optimal codesign of nonlinear control systems based on a modified policy iteration method.  

PubMed

This brief studies the optimal codesign of nonlinear control systems: simultaneous design of physical plants and related optimal control policies. Nonlinearity of the optimal codesign problem could come from either a nonquadratic cost function or the plant. After formulating the optimal codesign into a nonconvex optimization problem, an iterative scheme is proposed in this brief by adding an additional step of system-equivalence-based policy improvement to the conventional policy iteration. We have proved rigorously that the closed-loop system performance can be improved after each step of the proposed policy iteration scheme, and the convergence to a suboptimal solution is guaranteed. It is also shown that under certain conditions, this additional policy improvement step can be conducted by solving a quadratic programming problem. The linear version of the proposed methodology is addressed in the context of linear quadratic regulator. Finally, the effectiveness of the proposed methodology is illustrated through the optimal codesign of a load-positioning system. PMID:25576583

Jiang, Yu; Wang, Yebin; Bortoff, Scott A; Jiang, Zhong-Ping

2015-02-01

86

Status of the ITER neutral beam injection system.  

PubMed

The ITER neutral beam injectors are the first injectors to be designed to operate under conditions and constraints similar to those that will be encountered with a fusion reactor. The injectors will use a single large ion source and accelerator that will produce 40 A D(-) 1 MeV beams for pulse lengths of up to 3600 s. The accelerated ion beams will be neutralized in a gas (D(2)) neutralizer which is subdivided into four vertical channels to reduce the gas flow into the injectors that is needed to produce optimum target for neutralization. These injectors will have to operate in a hostile radiation environment and they will become highly radioactive due to the neutron flux from ITER. The design has been modified recently to have a rectangular vacuum vessel with a removable lid that allows vertical access to, and maintenance of, the beamline components, the incorporation of an absolute all metal valve at the exit of the injector, the choice of a rf driven ion source as the reference design of ion source, and to have a high voltage deck incorporating the various auxiliary power supplies in air rather that under high pressure SF(6). A major development is that it has been agreed that a Neutral Beam Test Facility (NBTF) will be set up at Padua, Italy. The NBTF will consist of two test beds: one of which will be capable of operating a complete injector at full performance. The second will be an ion source test bed, which will be used for the development and testing, to full performance, of the large negative ion source. PMID:18315235

Hemsworth, R S; Tanga, A; Antoni, V

2008-02-01

87

Design and overview of fabrication tests for the 1 MV bushing for ITER NB system  

Microsoft Academic Search

The ITER NB System consists of two injectors each delivering 16.7 MW to the plasma in the form of neutral deuterium atoms accelerated at 1 MeV. Each injector has a single negative ion source connected to a 1 MV electrostatic accelerator. The accelerated negative ions pass through a neutraliser, then an electrostatic deflection system, where residual ions, exiting after neutralisation,

E. Di Pietro; T. Amemiya; M. Hanada; T. Iga; T. Inoue; Y. Okumura; K. Watanabe

2003-01-01

88

Steady state and dynamic simulation of the ITER hydrogen isotope separation system  

SciTech Connect

Steady state and dynamic simulation studies of the ITER Hydrogen Isotope Separation System (ISS) are presented. Ontario Hydro`s FLOSHFET code is used as the reference code for design studies of the ISS. Dynamic simulation are also carried out using Ontario Hydro`s DYNSIM code. The ITER ISS dynamic simulation is important because it allows study of product quality control schemes and control system design. It also allows accurate assessment of tritium inventory variation in different operating modes. The cryogenic distillation model in the new DYNSIM code is described including the underlying theory and numerical simulation approach. 9 refs., 3 figs.

Busigin, A. [NITEK Corp., London (Canada); Sood, S.K. [Ontario Hydro, Toronto (Canada)

1995-10-01

89

ASTP communications systems analyses and performance predictions  

NASA Technical Reports Server (NTRS)

A research program was conducted to provide ASTP mission communication coverage and performance analyses and to analyze anomalies and special compatibility problems as they arise. The end product of the contract was spacecraft-to-ground communications performance predictions for the ASTP mission, both for direct communication links to ground and for those links via the ATS-6 relay satellite to ground. Solutions are given for the special mission anomalies and compatibility problems encountered. A brief summary describing the work activities expended is given.

1975-01-01

90

Matt Jewell ITER Organization  

E-print Network

system is made up of - 18 Toroidal Field (TF) Coils, - a 6-module Central Solenoid (CS), - 6 Poloidal System CS Coil #12;3/19 ITER Magnet System (2/2) · TF Coils are used for charged particles' confinement) nuclear heating Background slides courtesy A. Devred #12;2/19 ITER Magnet System (1/2) · The ITER magnet

McDonald, Kirk

91

US ITER Moving Forward  

ScienceCinema

US ITER Project Manager Ned Sauthoff, joined by Wayne Reiersen, Team Leader Magnet Systems, and Jan Berry, Team Leader Tokamak Cooling System, discuss the U.S.'s role in the ITER international collaboration.

US ITER / ORNL

2012-03-16

92

Analysing System\\/User Cooperation in KADS  

Microsoft Academic Search

With the introduction of active, knowledge based systems (KBS), the need for truely coop- erative systems grows. In this article we present a framework is presented for the analysis and specification of the way the user and a KBS should cooperate. This framework for user\\/system cooperation (KADS-FUSC) is part of the KADS methodology. KADS-FUSC is an extension of (Moran, 1981)'s

Joost Breuker; Paul de Greef

1992-01-01

93

Analysing Java System Properties Bachelor's thesis  

E-print Network

), Institute of Computer Science and Applied Mathematics, University of Bern, Switzerland By David Wettstein Java System Properties 1 Introduction David Wettstein, 8. December 2013 4 Contents 1 Introduction

Nierstrasz, Oscar

94

Lather (Interior Systems Mechanic). Occupational Analyses Series.  

ERIC Educational Resources Information Center

This analysis covers tasks performed by a lather, an occupational title some provinces and territories of Canada have also identified as drywall and acoustical mechanic; interior systems installer; and interior systems mechanic. A guide to analysis discusses development, structure, and validation method; scope of the occupation; trends; and…

Chapman, Mike; Chapman, Carol; MacLean, Margaret

95

Sprinkler System Installer. Occupational Analyses Series.  

ERIC Educational Resources Information Center

This analysis covers tasks performed by a sprinkler system installer, an occupational title some provinces and territories of Canada have also identified as pipefitter--fire protection mechanic specialty; sprinkler and fire protection installer; sprinkler and fire protection systems installer; and sprinkler fitter. A guide to analysis discusses…

Chinien, Chris; Boutin, France

96

Initial results of systems analysis of the ITER design space  

SciTech Connect

This series of vugraphs presents preliminary analyses of various design points for the next generation thermonuclear test reactor. The authors state that constrained optimization of a figure-of-merit leads to acceptable design points. Design points discussed include: device radius, aspect ratio, magnetic field strength, magnet current, plasma current, and ignition margin. (JDH)

Peng, Y.K.M.; Galambos, J.D.; Reid, R.L.; Strickler, D.J.; Kalsi, S.S.; Deleanu, L.

1987-01-01

97

An iterative inter-track interference mitigation method for two-dimensional magnetic recording systems  

NASA Astrophysics Data System (ADS)

At high recording density, the readback signal of two-dimensional magnetic recording is inevitably corrupted by the two-dimensional (2D) interference consisting of inter-symbol interference and inter-track interference (ITI), which can significantly degrade the overall system performance. This paper proposes an iterative ITI mitigation method using three modified 2D soft-output Viterbi algorithm (2D-SOVA) detectors in conjunction with an iterative processing technique to combat the 2D interference. The codeword of the outer code is divided and then written on three separate tracks. For every iteration, all 2D-SOVA detectors exchange the soft information to improve the reliability of the a priori information and use it in the branch metric calculation, before feeding the refined soft information to the outer decoder. Simulation results show that the proposed method outperforms the conventional receiver and the existing partial ITI mitigation method.

Warisarn, C.; Losuwan, T.; Supnithi, P.; Kovintavewat, P.

2014-05-01

98

Variable sampling frequency in iterative learning current Control for Shunt Active Filter in aircraft power systems  

Microsoft Academic Search

This paper investigates the feasibility of an Iterative Leaning current Control (ILC) with variable sampling frequency to realize a 3-phase Shunt Active Filter (SAF) used for harmonic compensation in new generation aircrafts, where a Variable Speed Variable-Frequency (VSVF) power system, typically between 360 and 900Hz, is nowadays used. Due to the high supply frequency, such applications are particularly demanding for

Pericle Zanchetta; Marco Degano; Junyi Liu; Paolo Mattavelli

2011-01-01

99

Tritium environmental source terms for the effluents of ITER water systems  

Microsoft Academic Search

An analysis of the heat transport and water detritiation systems of ITER has been performed in order to determine major pathways for tritium loss and estimate releases during normal operation (operational tritium release). Heavy water escape and tritium release estimates compiled on the basis of operating experiences of typical CANDU PWR and the Darlington Tritium Removal Facility (DTRF) have been

K. M. Kalyanam; C. Fong; M. Moledina; A. Natalizio

1995-01-01

100

The European test blanket module systems: Design and integration in ITER  

Microsoft Academic Search

The European Union proposes two different concepts of helium-cooled blanket for testing in ITER, one with ceramic breeder and beryllium, the second with lithium lead as breeder and multiplier. Test blanket modules (TBM) for both blanket concepts and their auxiliary systems have being designed in the last 2 years; this paper presents the status of this work as reached in

L. V. Boccaccini; J.-F. Salavy; R. Lässer; A. Li Puma; R. Meyder; H. Neuberger; Y. Poitevin; G. Rampal

2006-01-01

101

Mechanical strength of an ITER coil insulation system under static and dynamic load after reactor irradiation  

Microsoft Academic Search

The insulation system proposed by the Japanese Home Team for the ITER Toroidal Field coil (TF coil) is a T-glass–fiber\\/Kapton reinforced epoxy prepreg system. In order to assess the material performance under the actual operating conditions of the coils, the insulation system was irradiated in the TRIGA reactor (Vienna) to a fast neutron fluence of 2×1022 m?2 (E>0.1 MeV). After

K. Bittnerrohrhofer; K. Humer; H. W. Weber; K. Hamada; M. Sugimoto; K. Okuno

2002-01-01

102

Systems Analyses of Advanced Brayton Cycles  

SciTech Connect

The main objective is to identify and assess advanced improvements to the Brayton Cycle (such as but not limited to firing temperature, pressure ratio, combustion techniques, intercooling, fuel or combustion air augmentation, enhanced blade cooling schemes) that will lead to significant performance improvements in coal based power systems. This assessment is conducted in the context of conceptual design studies (systems studies) that advance state-of-art Brayton cycles and result in coal based efficiencies equivalent to 65% + on natural gas basis (LHV), or approximately an 8% reduction in heat rate of an IGCC plant utilizing the H class steam cooled gas turbine. H class gas turbines are commercially offered by General Electric and Mitsubishi for natural gas based combined cycle applications with 60% efficiency (LHV) and it is expected that such machine will be offered for syngas applications within the next 10 years. The studies are being sufficiently detailed so that third parties will be able to validate portions or all of the studies. The designs and system studies are based on plants for near zero emissions (including CO{sub 2}). Also included in this program is the performance evaluation of other advanced technologies such as advanced compression concepts and the fuel cell based combined cycle. The objective of the fuel cell based combined cycle task is to identify the desired performance characteristics and design basis for a gas turbine that will be integrated with an SOFC in Integrated Gasification Fuel Cell (IGFC) applications. The goal is the conceptualization of near zero emission (including CO{sub 2} capture) integrated gasification power plants producing electricity as the principle product. The capability of such plants to coproduce H{sub 2} is qualitatively addressed. Since a total systems solution is critical to establishing a plant configuration worthy of a comprehensive market interest, a baseline IGCC plant scheme is developed and used to study how alternative process schemes and power cycles might be used and integrated to achieve higher systems efficiency. To achieve these design results, the total systems approach is taken requiring creative integration of the various process units within the plant. Advanced gas turbine based cycles for Integrated gasification Combined cycle (IGCC) applications are identified by a screening analysis and the more promising cycles recommended for detailed systems analysis. In the case of the IGFC task, the main objective is met by developing a steady-state simulation of the entire plant and then using dynamic simulations of the hybrid Solid Oxide Fuel Cell (SOFC)/Gas Turbine sub-system to investigate the turbo-machinery performance. From these investigations the desired performance characteristics and a basis for design of turbo-machinery for use in a fuel cell gas turbine power block is developed.

A.D. Rao; D.J. Francuz; J.D. Maclay; J. Brouwer; A. Verma; M. Li; G.S. Samuelsen

2008-09-30

103

iterative solution of augmented systems arising in interior methods  

E-print Network

solution of a symmetric indefinite linear system of equations known as the KKT system. .... to solve KKT systems are (i) termination control, (ii) inertia control, and (iii) inherent ill-conditioning. ...... problems will be the subject of a follow-up paper.

2005-09-04

104

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

2009-01-01

105

Modelling Adaptive Dynamical Systems to Analyse Eating Regulation Disorders  

E-print Network

Modelling Adaptive Dynamical Systems to Analyse Eating Regulation Disorders Tibor Bosse1 , Martine, an executable model has been developed of the dynamics of eating regulation disorders. Based on this model, The Netherlands Abstract. To analyse the disorders of their patients, psychotherapists often have to get insight

Treur, Jan

106

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

E-print Network

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

2005-03-02

107

Total-system performance assessment for Yucca Mountain - SNL second iteration (TSPA-1993); Volume 1  

SciTech Connect

Sandia National Laboratories has completed the second iteration of the periodic total-system performance assessments (TSPA-93) for the Yucca Mountain Site Characterization Project (YMP). These analyses estimate the future behavior of a potential repository for high-level nuclear waste at the Yucca Mountain, Nevada, site under consideration by the Department of Energy. TSPA-93 builds upon previous efforts by emphasizing YMP concerns relating to site characterization, design, and regulatory compliance. Scenarios describing expected conditions (aqueous and gaseous transport of contaminants) and low-probability events (human-intrusion drilling and volcanic intrusion) are modeled. The hydrologic processes modeled include estimates of the perturbations to ambient conditions caused by heating of the repository resulting from radioactive decay of the waste. Hydrologic parameters and parameter probability distributions have been derived from available site data. Possible future climate changes are modeled by considering two separate groundwater infiltration conditions: {open_quotes}wet{close_quotes} with a mean flux of 10 mm/yr, and {open_quotes}dry{close_quotes} with a mean flux of 0.5 mm/yr. Two alternative waste-package designs and two alternative repository areal thermal power densities are investigated. One waste package is a thin-wall container emplaced in a vertical borehole, and the second is a container designed with corrosion-resistant and corrosion-allowance walls emplaced horizontally in the drift. Thermal power loadings of 57 kW/acre (the loading specified in the original repository conceptual design) and 114 kW/acre (a loading chosen to investigate effects of a {open_quotes}hot repository{close_quotes}) are considered. TSPA-93 incorporates significant new detailed process modeling, including two- and three-dimensional modeling of thermal effects, groundwater flow in the saturated-zone aquifers, and gas flow in the unsaturated zone.

Wilson, M.L.; Gauthier, J.H.; Barnard, R.W.; Barr, G.E.; Dockery, H.A.; Dunn, E.; Eaton, R.R.; Guerin, D.C.; Lu, N.; Martinez, M.J. [and others] [and others

1994-04-01

108

ANAEROBIC COMPOST CONSTRUCTED WETLANDS SYSTEM TECHNOLOGY - SITE ITER  

EPA Science Inventory

In Fall 1994, anaerobic compost wetlands in both upflow and downflow configurations were constructed adjacent to and received drainage from the Burleigh Tunnel, which forms part of the Clear Creek/Central City Superfund site. The systems were operated over a 3 year period. The e...

109

Materials issues in diagnostic systems for BPX and ITER  

SciTech Connect

Diagnostic systems in advanced D-T-burning fusion devices will be subjected to intense fluxes and fluences of high-energy neutrons and gamma rays. Materials used in these systems may suffer significant degradation of structural, optical, and electrical properties, either promptly upon irradiation or after accumulation of structural damage. Of particular concern are windows, optical fibers, reflectors, and insulators. Many materials currently specified for these components are known to degrade under anticipated operating conditions. However, careful materials selection and modification based on an appropriate irradiation testing program, when combined with optimization of design-sensitive factors such as location, shielding, and ease of replacement, should help to alleviate these materials problems. 30 refs., 2 figs., 1 tab.

Clinard, F.W. Jr.; Farnum, E.H. (Los Alamos National Lab., NM (United States)); Griscom, D.L. (Naval Research Lab., Washington, DC (United States)); Mattas, R.F. (Argonne National Lab., IL (United States)); Medley, S.S.; Young, K. M. (Princeton Univ., NJ (United States). Plasma Physics Lab.); Wiffen, F.W. (USDOE, Washington, DC (United States)); Wojtowicz, S.S. (General Atomics, San Diego, CA (Unit

1991-01-01

110

Modeling heterogeneous and fractured reservoirs with inverse methods based on iterated function systems  

SciTech Connect

Fractured and heterogeneous reservoirs are complex and difficult to characterize. In many cases, the modeling approaches used for making predictions of behavior in such reservoirs have been unsatisfactory. In this paper we describe a new modeling approach which results in a model that has fractal-like qualities. This is an inverse approach which uses observations of reservoir behavior to create a model that can reproduce observed behavior. The model is described by an iterated function system (IFS) that creates a fractal-like object that can be mapped into a conductivity distribution. It may be possible to identify subclasses of Iterated Function Systems which describe geological facies. By limiting the behavior-based search for an IFS to the geologic subclasses, we can condition the reservoir model on geologic information. This technique is under development, but several examples provide encouragement for eventual application to reservoir prediction.

Long, J.C.S.; Doughty, C.; Hestir, K.; Martel, S.

1992-05-01

111

Adaptive iterated function systems filter for images highly corrupted with fixed - Value impulse noise  

NASA Astrophysics Data System (ADS)

The Adaptive Iterated Functions Systems (AIFS) Filter presented in this paper has an outstanding potential to attenuate the fixed-value impulse noise in images. This filter has two distinct phases namely noise detection and noise correction which uses Measure of Statistics and Iterated Function Systems (IFS) respectively. The performance of AIFS filter is assessed by three metrics namely, Peak Signal-to-Noise Ratio (PSNR), Mean Structural Similarity Index Matrix (MSSIM) and Human Visual Perception (HVP). The quantitative measures PSNR and MSSIM endorse the merit of this filter in terms of degree of noise suppression and details/edge preservation respectively, in comparison with the high performing filters reported in the recent literature. The qualitative measure HVP confirms the noise suppression ability of the devised filter. This computationally simple noise filter broadly finds application wherein the images are highly degraded by fixed-value impulse noise.

Shanmugavadivu, P.; Eliahim Jeevaraj, P. S.

2014-06-01

112

A model of asynchronous iterative algorithms for solving large, sparse, linear systems  

NASA Technical Reports Server (NTRS)

Solving large, sparse, linear systems of equations is one of the fundamental problems in large scale scientific and engineering computation. A model of a general class of asynchronous, iterative solution methods for linear systems is developed. In the model, the system is solved by creating several cooperating tasks that each compute a portion of the solution vector. This model is then analyzed to determine the expected intertask data transfer and task computational complexity as functions of the number of tasks. Based on the analysis, recommendations for task partitioning are made. These recommendations are a function of the sparseness of the linear system, its structure (i.e., randomly sparse or banded), and dimension.

Reed, D. A.; Patrick, M. L.

1984-01-01

113

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

SciTech Connect

During inductive plasma operation of ITER, fusion power will reach 500 MW with an energy multiplication factor of 10. The heat will be transferred by the Tokamak Cooling Water System (TCWS) to the environment using the secondary cooling system. Plasma operations are inherently safe even under the most severe postulated accident condition a large, in-vessel break that results in a loss-of-coolant accident. A functioning cooling water system is not required to ensure safe shutdown. Even though ITER is inherently safe, TCWS equipment (e.g., heat exchangers, piping, pressurizers) are classified as safety important components. This is because the water is predicted to contain low-levels of radionuclides (e.g., activated corrosion products, tritium) with activity levels high enough to require the design of components to be in accordance with French regulations for nuclear pressure equipment, i.e., the French Order dated 12 December 2005 (ESPN). ESPN has extended the practical application of the methodology established by the Pressure Equipment Directive (97/23/EC) to nuclear pressure equipment, under French Decree 99-1046 dated 13 December 1999, and Order dated 21 December 1999 (ESP). ASME codes and supplementary analyses (e.g., Failure Modes and Effects Analysis) will be used to demonstrate that the TCWS equipment meets these essential safety requirements. TCWS is being designed to provide not only cooling, with a capacity of approximately 1 GW energy removal, but also elevated temperature baking of first-wall/blanket, vacuum vessel, and divertor. Additional TCWS functions include chemical control of water, draining and drying for maintenance, and facilitation of leak detection/localization. The TCWS interfaces with the majority of ITER systems, including the secondary cooling system. U.S. ITER is responsible for design, engineering, and procurement of the TCWS with industry support from an Engineering Services Organization (ESO) (AREVA Federal Services, with support from Northrop Grumman, and OneCIS). ITER International Organization (ITER-IO) is responsible for design oversight and equipment installation in Cadarache, France. TCWS equipment will be fabricated using ASME design codes with quality assurance and oversight by an Agreed Notified Body (approved by the French regulator) that will ensure regulatory compliance. This paper describes the TCWS design and how U.S. ITER and fabricators will use ASME codes to comply with EU Directives and French Orders and Decrees.

Berry, Jan [ORNL] [ORNL; Ferrada, Juan J [ORNL] [ORNL; Curd, Warren [ITER Organization, Saint Paul Lez Durance, France] [ITER Organization, Saint Paul Lez Durance, France; Dell Orco, Dr. Giovanni [ITER Organization, Saint Paul Lez Durance, France] [ITER Organization, Saint Paul Lez Durance, France; Barabash, Vladimir [ITER Organization, Saint Paul Lez Durance, France] [ITER Organization, Saint Paul Lez Durance, France; Kim, Seokho H [ORNL] [ORNL

2011-01-01

114

BNL Pulsed Magnet Magnet System Cooldown and Structural Analyses  

E-print Network

for two cooling modes Helium-Liquid Hydrogen Heat Exchange System #12;Coil Stress Analysis The threeBNL Pulsed Magnet Magnet System Cooldown and Structural Analyses 2002 The Collaboration is Useful 74K 3 15T Helium Gas 78K 22K 30K Proposed Operational Scenarios The coil and cryostat are designed

McDonald, Kirk

115

Characterisation of the Sub-Harmonic Arc Detection System on JET ITER-Like Antenna  

SciTech Connect

A Sub-Harmonic Arc Detection (SHAD) system has been installed on the transmission lines feeding the JET ICRF ITER-like-Antenna (ILA). Along with the commissioning of SHAD, extensive measurements of the RF field in the transmission lines were carried-out using fast sampling (125 Mb/s) oscilloscopes. The system is described, and the SHAD ability to detect arcs during ILA operation (in particular on ELMy H modes) is discussed. Overall, SHAD proved to be efficient, and in some conditions it can offer extra protection in complement to other arc detection systems.

Jacquet, P.; Blackman, T.; Mayoral, M.-L.; Nightingale, M. [EURATOM/UKAEA Fusion Association, Culham Science Center, Abingdon, OX14 3DB (United Kingdom); Berger-By, G. [Association EURATOM/CEA, IRFM, F-13108 Saint-Paul-lez Durances (France); Bobkov, V. [Max Planck IPP/EURATOM Assoziation, D-85748 Garching (Germany); Durodie, F. [Association EURATOM/Belgium State, LPP-ERM/KMS, B-1000 Brussels (Belgium)

2009-11-26

116

Operational Experience with the Scattering Matrix Arc Detection System on the JET ITER-Like Antenna  

SciTech Connect

The Scattering Matrix Arc Detection System (SMAD) has been fully deployed on all 4 sets of Resonant Double Loop (RDL), Vacuum Transmission Line (VTL) and Antenna Pressurised Transmission Lines (APTL) of the JET ICRF ITER-Like Antenna (ILA) and this has been indispensable for operating at low (real) T-point impedance values to investigate ELM tolerance. This paper describes the necessity of the SMAD vs VSWR (Voltage Standing Wave Ratio) protection system, SMAD commissioning, problems and a number of typical events detected by the SMAD system during operation on plasma.

Vrancken, M.; Lerche, E.; Dumortier, P.; Durodie, F.; Evrard, M.; Huygen, S.; Ongena, J.; Van Eester, D.; Van Schoor, M.; Vervier, M.; Weynants, R. [LPP/ERM-KMS, Association EURATOM-Belgian State, Brussels (Belgium); Blackman, T.; Graham, M.; Jacquet, P.; Kaye, A.; Mayoral, M.-L.; Nightingale, M. P. S. [EURATOM/UKAEA Fusion Association, Culham Science Center (United Kingdom); Goulding, R. H. [Oak Ridge National Laboratory, Oak Ridge (United States)

2009-11-26

117

Implementation of iterative methods for large sparse nonsymmetric linear systems on a parallel vector machine  

SciTech Connect

This paper reports on the restructure of three outstanding iterative methods for large space nonsymmetric linear systems. These methods are CGS (conjugate gradient squared), CRS (conjugate residual squared), and Orthomin(k). The restructured methods are more suitable for vector and parallel processing. The authors implemented these methods on a parallel vector system. The linear systems for the numerical tests are obtained from discretizing four two- dimensional elliptic partial differential equations by finite difference and finite element methods. A vectorizable and parallelizable version of incomplete LU preconditioning is used. The authors restructured the subroutines to enhance the data locality in vector machines with storage hierarchy. Speedup was measured for multitasking by four processors.

Ma, S.; Chronopoulos, A.T. (Dept. of Computer Science, Univ. of Minnesota, Minneapolis, MN (US))

1990-01-01

118

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

SciTech Connect

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)

2011-06-15

119

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

PubMed

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°-40° 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. PMID:21721690

Takahashi, K; Kajiwara, K; Oda, Y; Kasugai, A; Kobayashi, N; Sakamoto, K; Doane, J; Olstad, R; Henderson, M

2011-06-01

120

Interruptible iterators  

Microsoft Academic Search

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 iter- ation abstraction well from the standpoint of client code, they are awkward to implement

Jed Liu; Aaron Kimball; Andrew C. Myers

2006-01-01

121

Interruptible iterators  

Microsoft Academic Search

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

Jed Liu; Aaron Kimball; Andrew C. Myers

2006-01-01

122

Mechanical property tests on structural materials for ITER magnet system at low temperatures in China  

NASA Astrophysics Data System (ADS)

High field superconducting magnets need strong non-superconducting components for structural reinforcement. For instance, the ITER magnet system (MS) consists of cable-in-conduit conductor, coil case, magnet support, and insulating materials. Investigation of mechanical properties at magnet operation temperature with specimens machined at the final manufacturing stages of the conductor jacket materials, magnet support material, and insulating materials, even the component of the full-size conductor jacket is necessary to establish sound databases for the products. In China, almost all mechanical property tests of structural materials for the ITER MS, including conductor jacket materials of TF coils, PF coils, CCs, case material of CCs, conductor jacket materials of Main Busbars (MB) and Corrector Busbars (CB), material of magnet supports, and insulating materials of CCs have been carried out at the Technical Institute of Physics and Chemistry (TIPC), Chinese Academy of Sciences (CAS). In this paper, the mechanical property test facilities are briefly demonstrated and the mechanical tests on the structural materials for the ITER MS, highlighting test rigs as well as test methods, are presented.

Huang, Chuanjun; Huang, Rongjin; Li, Laifeng

2014-01-01

123

RF Matching Feedback Control Systems on the JET ITER-Like Antenna  

SciTech Connect

Ion Cyclotron Resonance Frequency (ICRF) antennas achieve maximum power transfer from RF generator to plasma load by establishing an impedance match. The JET ITER-Like Antenna (ILA) consists of 4 mutually coupled resonators that need to be matched simultaneously and whose resonant states need to be accurately controlled by several available actuators to couple maximum power and to achieve optimal ELM resilience. The operation of the matching system is described. Experimental operation revealed some phenomena and sensitivities that did not surface from simulation alone and that should be taken into account for the design of future ICRF antennae systems.

Vrancken, M.; Dumortier, P.; Durodie, F.; Huygen, S.; Lerche, E.; Messiaen, A. M.; Ongena, J.; Van Eester, D.; Van Schoor, M.; Vervier, M.; Weynants, R. [LPP/ERM-KMS, Association EURATOM-Belgian State, Brussels (Belgium); Argouarch, A. [Association EURATOM/CEA, CEA Cadarache (France); Blackman, T.; Graham, M.; Jacquet, P.; Mayoral, M.-L.; Nightingale, M. P. S.; Whitehurst, A. [EURATOM/UKAEA Fusion Association, Culham Science Center (United Kingdom); Goulding, R. H. [Oak Ridge National Laboratory, Oak Ridge (United States)

2009-11-26

124

Design and Analysis of the Main AC/DC Converter System for ITER  

NASA Astrophysics Data System (ADS)

A design of the main AC/DC converter system for ITER is described and the configuration of the main AC/DC converters is presented. To reduce the reactive power absorbed from the converter units, the main AC/DC converters are designed to be series-connected and work in a sequential mode. The structure of the regulator of the converter system is described. A simulation model was built up for the PSCAD/EMTDC code, and the design was validated accordingly. Harmonic analysis and reactive power calculation of the converters units are presented. The results reveal the advantage of sequential control in reducing reactive power and harmonics.

Sheng, Zhicai; Xu, Liuwei; Fu, Peng

2012-04-01

125

X-34 Main Propulsion System-Selected Subsystem Analyses  

NASA Technical Reports Server (NTRS)

The X-34 hypersonic flight vehicle is currently under development by Orbital Sciences Corporation (Orbital). The Main Propulsion System (MPS) has been designed around the liquid propellant Fastrac rocket engine currently under development at NASA Marshall Space Flight Center. This paper presents selected analyses of MPS subsystems and components. Topics include the integration of component and system level modeling of the LOX dump subsystem and a simple terminal bubble velocity analysis conducted to guide propellant feed line design.

Brown, T. M.; McDonald, J. P.; Knight, K. C.; Champion, R. H., Jr.

1998-01-01

126

A new fractal-interpolation algorithm for seismic data based on iterated function systems  

NASA Astrophysics Data System (ADS)

A new fractal-interpolation method called PPA (Pointed Point Algorithm) based on the Iterated Function System (IFS) is proposed to interpolate the signals with the expected interpolation error, solving the problem that the ordinary fractal interpolation cannot get the value of any arbitrary point directly, which has not been found in the existing literature. Experiments on the theoretical data and real field seismic data show that the proposed PPA method can not only get the expected point's value, but also get a great accuracy in the reconstruction of the seismic profile, leading to a significant improvement over other trace interpolation methods.

Zhai, Ming-Yue; Kuzma, Heidi; Rector, James W.

2010-11-01

127

A protection system for the JET ITER-like wall based on imaging diagnosticsa)  

NASA Astrophysics Data System (ADS)

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.; Devaux, S.; Alves, D.; Balboa, I.; Balorin, C.; Balshaw, N.; Beldishevski, M.; Carvalho, P.; Clever, M.; Cramp, S.; de Pablos, J.-L.; de la Cal, E.; Falie, D.; Garcia-Sanchez, P.; Felton, R.; Gervaise, V.; Goodyear, A.; Horton, A.; Jachmich, S.; Huber, A.; Jouve, M.; Kinna, D.; Kruezi, U.; Manzanares, A.; Martin, V.; McCullen, P.; Moncada, V.; Obrejan, K.; Patel, K.; Lomas, P. J.; Neto, A.; Rimini, F.; Ruset, C.; Schweer, B.; Sergienko, G.; Sieglin, B.; Soleto, A.; Stamp, M.; Stephen, A.; Thomas, P. D.; Valcárcel, D. F.; Williams, J.; Wilson, J.; Zastrow, K.-D.; JET-EFDA Contributors

2012-10-01

128

Evolution of the Design of Cold Mass Support for the ITER Magnet Feeder System  

NASA Astrophysics Data System (ADS)

This paper presents the evolution of the design of cold mass support for the ITER magnet feeder system. The glass fibers in the cylinder and the flanges of the normal G10 support are discontinuous in the preliminary design. The heat load of this support from the analysis is only 4.86 W. However, the mechanical test of the prototype showed that it can only endure 9 kN lateral force, which is significantly less than the required 20 kN. So, the configuration of the glass fibers in the cylinders and flanges of this G10 support are modified by changing it to a continuous and knitted type to reinforce the support, and then a new improved prototype is manufactured and tested. It could endure 15 kN lateral forces this time, but still not meet the required 20 kN. Finally, the SS316LN material is chosen for the cold mass supports. The analysis results show that it is safe under 20 kN lateral forces with the heat load increased to 14.8 W. Considering the practical application, the requirements of strength is of primary importance. So, this SS316LN cold mass support is acceptable for the ITER magnet feeder system. On the other hand, the design idea of using continuous and knitted glass fibers to reinforce the strength of a G10 support is a good reference for the case with a lower heat load and not too high Lorentz force.

Lu, Kun; Song, Yuntao; Niu, Erwu; Zhou, Tinzhi; Wang, Zhongwei; Chen, Yonghua; Zhu, Yinfeng

2013-02-01

129

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] [University of California, Los Angeles; Popov, Emilian L [ORNL] [ORNL

2011-01-01

130

Low-Bit Rate Feedback Strategies for Iterative IA-Precoded MIMO-OFDM-Based Systems  

PubMed Central

Interference alignment (IA) is a promising technique that allows high-capacity gains in interference channels, but which requires the knowledge of the channel state information (CSI) for all the system links. We design low-complexity and low-bit rate feedback strategies where a quantized version of some CSI parameters is fed back from the user terminal (UT) to the base station (BS), which shares it with the other BSs through a limited-capacity backhaul network. This information is then used by BSs to perform the overall IA design. With the proposed strategies, we only need to send part of the CSI information, and this can even be sent only once for a set of data blocks transmitted over time-varying channels. These strategies are applied to iterative MMSE-based IA techniques for the downlink of broadband wireless OFDM systems with limited feedback. A new robust iterative IA technique, where channel quantization errors are taken into account in IA design, is also proposed and evaluated. With our proposed strategies, we need a small number of quantization bits to transmit and share the CSI, when comparing with the techniques used in previous works, while allowing performance close to the one obtained with perfect channel knowledge. PMID:24678274

Teodoro, Sara; Silva, Adão; Dinis, Rui; Gameiro, Atílio

2014-01-01

131

Low-bit rate feedback strategies for iterative IA-precoded MIMO-OFDM-based systems.  

PubMed

Interference alignment (IA) is a promising technique that allows high-capacity gains in interference channels, but which requires the knowledge of the channel state information (CSI) for all the system links. We design low-complexity and low-bit rate feedback strategies where a quantized version of some CSI parameters is fed back from the user terminal (UT) to the base station (BS), which shares it with the other BSs through a limited-capacity backhaul network. This information is then used by BSs to perform the overall IA design. With the proposed strategies, we only need to send part of the CSI information, and this can even be sent only once for a set of data blocks transmitted over time-varying channels. These strategies are applied to iterative MMSE-based IA techniques for the downlink of broadband wireless OFDM systems with limited feedback. A new robust iterative IA technique, where channel quantization errors are taken into account in IA design, is also proposed and evaluated. With our proposed strategies, we need a small number of quantization bits to transmit and share the CSI, when comparing with the techniques used in previous works, while allowing performance close to the one obtained with perfect channel knowledge. PMID:24678274

Teodoro, Sara; Silva, Adão; Dinis, Rui; Gameiro, Atílio

2014-01-01

132

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] [ORNL; Reiersen, Wayne T [ORNL] [ORNL

2011-01-01

133

LSRN: A PARALLEL ITERATIVE SOLVER FOR STRONGLY OVER- OR UNDERDETERMINED SYSTEMS*  

PubMed Central

We describe a parallel iterative least squares solver named LSRN that is based on random normal projection. LSRN computes the min-length solution to minx??n ?Ax ? b?2, where A ? ?m × n with m ? n or m ? n, and where A may be rank-deficient. Tikhonov regularization may also be included. Since A is involved only in matrix-matrix and matrix-vector multiplications, it can be a dense or sparse matrix or a linear operator, and LSRN automatically speeds up when A is sparse or a fast linear operator. The preconditioning phase consists of a random normal projection, which is embarrassingly parallel, and a singular value decomposition of size ?? min(m, n)? × min(m, n), where ? is moderately larger than 1, e.g., ? = 2. We prove that the preconditioned system is well-conditioned, with a strong concentration result on the extreme singular values, and hence that the number of iterations is fully predictable when we apply LSQR or the Chebyshev semi-iterative method. As we demonstrate, the Chebyshev method is particularly efficient for solving large problems on clusters with high communication cost. Numerical results show that on a shared-memory machine, LSRN is very competitive with LAPACK’s DGELSD and a fast randomized least squares solver called Blendenpik on large dense problems, and it outperforms the least squares solver from SuiteSparseQR on sparse problems without sparsity patterns that can be exploited to reduce fill-in. Further experiments show that LSRN scales well on an Amazon Elastic Compute Cloud cluster. PMID:25419094

Meng, Xiangrui; Saunders, Michael A.; Mahoney, Michael W.

2014-01-01

134

Compartment Venting Analyses of Ares I First Stage Systems Tunnel  

NASA Technical Reports Server (NTRS)

Compartment venting analyses have been performed for the Ares I first stage systems tunnel using both the lumped parameter method and the three-dimensional (31)) transient computational fluid dynamics (CFD) approach. The main objective of venting analyses is to predict the magnitudes of differential pressures across the skin so the integrity of solid walls can be evaluated and properly designed. The lumped parameter method assumes the gas pressure and temperature inside the systems tunnel are spatially uniform, which is questionable since the tunnel is about 1,700 in. long and 4 in. wide. Therefore, 31) transient CFD simulations using the commercial CFD code FLUENT are performed in order to examine the gas pressure and temperature variations inside the tunnel. It was found that the uniform pressure and temperature assumptions inside the systems tunnel are valid during ascent. During reentry, the uniform pressure assumption is also reasonable but the uniform temperature assumption is not valid. Predicted pressure and temperature inside the systems tunnel using CFD are also compared with those from the lumped parameter method using the NASA code CHCHVENT. In general, the average pressure and temperature inside the systems tunnel from CFD are between the burst and crush results from CHCHVENT during both ascent and reentry. The skin differential pressure and pressure inside the systems tunnel relative to freestream pressure from CHCHVENT as well as velocity vectors and streamlines are also discussed in detail.

Wang, Qunzhen; Arner, Stephen

2009-01-01

135

An iterative method for coil sensitivity estimation in multi-coil MRI systems.  

PubMed

This paper presents an iterative coil sensitivity estimation method for multi-coil MRI systems. The proposed method works with coil images in the magnitude image domain. It determines a region of support (RoS), a region being composed of the same type of tissues, by a region growing algorithm, which makes use of both intensities and intensity gradients of pixels. By repeating this procedure, it can determine multiple regions of support, which together cover most of the concerned image area. The union of these regions of support provides a rough estimate of the sensitivity of each coil through dividing the intensities of pixels by the average intensity inside every region of support. The obtained rough coil sensitivity estimate is further approached with the product of multiple low-order polynomials, rather than a single one. The product of these polynomials provides a smooth estimate of the sensitivity of each coil. With the obtained sensitivities of coils, it can produce a better reconstructed image, which determines more correct regions of support and yields preciser estimates of the sensitivities of coils. In other words, the method can be iteratively implemented to improve the estimation performance. The proposed method was verified through both simulated data and clinical data from different body parts. The experimental results confirm the superiority of our method to some conventional methods. PMID:25169583

Ling, Qiang; Li, Zhaohui; Song, Kaikai; Li, Feng

2014-12-01

136

Information security system by iterative multiple-phase retrieval and pixel random permutation  

NASA Astrophysics Data System (ADS)

A novel information security system based on multiple-phase retrieval by an iterative Fresnel-transform algorithm and pixel random permutation (PRP) technique is proposed. In this method a series of phase masks cascaded in free space are employed and the phase distributions of all the masks are adjusted simultaneously in each iteration. It can achieve faster convergence and better quality of the recovered image compared with double-phase encoding and a similar approach in the spatial-frequency domain with the same number of phase masks and can provide a higher degree of freedom in key space with more geometric parameters as supplementary keys. Furthermore, the security level of this method is greatly improved by the introduction of the PRP technique. The feasibility of this method and its robustness against occlusion and additional noise attacks are verified by computer simulations. The performance of this technique for different numbers of phase masks and quantized phase levels is investigated systematically with the correlation coefficient and mean square error as convergence criterions.

Meng, Xiang-Feng; Cai, Lu-Zhong; Yang, Xiu-Lun; Shen, Xiao-Xia; Dong, Guo-Yan

2006-05-01

137

Iterative Solution Of Dense Linear Systems Arising From Boundary Element Formulations Of The Biomagnetic Inverse Problem  

E-print Network

. Magnetoencephalography (MEG) is a noninvasive technique for studying neuronal activity in the living human brain. Weak magnetic fields caused by the activity are measured from outside the head. Based on these measurements the source of the activity is located with the help of a mathematical model. A part of the localization is the repeated computation of the electric potential on the surface of the brain caused by a known electric source. In this paper we study the iterative solution of dense linear systems that arise from a boundary element discretization of the potential integral equation. We show that preconditioned iterative methods, such as BI-CGSTAB with the ILU(0) preconditioner, can easily outperform direct solvers for the problem. We also compute analytically the eigenvalues of the integral operator for a spherical model and show how these are approximated by the eigenvalues of the coefficient matrix. AMS subject classification: 45B05, 65F10, 65F15, 65R20, 78A70. Key word...

Jussi Rahola; Satu Tissari

1998-01-01

138

Enhancing the Reflexivity of System Innovation Projects with System Analyses  

ERIC Educational Resources Information Center

Networks aiming for fundamental changes bring together a variety of actors who are part and parcel of a problematic context. These system innovation projects need to be accompanied by a monitoring and evaluation approach that supports and maintains reflexivity to be able to deal with uncertainties and conflicts while challenging current practices…

van Mierlo, Barbara; Arkesteijn, Marlen; Leeuwis, Cees

2010-01-01

139

Multi-Element Unstructured Analyses of Complex Valve Systems  

NASA Technical Reports Server (NTRS)

The safe and reliable operation of high pressure test stands for rocket engine and component testing places an increased emphasis on the performance of control valves and flow metering devices. In this paper, we will present a series of high fidelity computational analyses of systems ranging from cryogenic control valves and pressure regulator systems to cavitating venturis that are used to support rocket engine and component testing at NASA Stennis Space Center. A generalized multi-element framework with sub-models for grid adaption, grid movement and multi-phase flow dynamics has been used to carry out the simulations. Such a framework provides the flexibility of resolving the structural and functional complexities that are typically associated with valve-based high pressure feed systems and have been difficult to deal with traditional CFD methods. Our simulations revealed a rich variety of flow phenomena such as secondary flow patterns, hydrodynamic instabilities, fluctuating vapor pockets etc. In the paper, we will discuss performance losses related to cryogenic control valves, and provide insight into the physics of the dominant multi-phase fluid transport phenomena that are responsible for the choking like behavior in cryogenic control elements. Additionally, we will provide detailed analyses of the modal instability that is observed in the operation of the dome pressure regulator valve. Such instabilities are usually not localized and manifest themselves as a system wide phenomena leading to an undesirable chatter at high flow conditions.

Sulyma, Peter (Technical Monitor); Ahuja, Vineet; Hosangadi, Ashvin; Shipman, Jeremy

2004-01-01

140

YALINA analytical benchmark analyses using the deterministic ERANOS code system.  

SciTech Connect

The growing stockpile of nuclear waste constitutes a severe challenge for the mankind for more than hundred thousand years. To reduce the radiotoxicity of the nuclear waste, the Accelerator Driven System (ADS) has been proposed. One of the most important issues of ADSs technology is the choice of the appropriate neutron spectrum for the transmutation of Minor Actinides (MA) and Long Lived Fission Products (LLFP). This report presents the analytical analyses obtained with the deterministic ERANOS code system for the YALINA facility within: (a) the collaboration between Argonne National Laboratory (ANL) of USA and the Joint Institute for Power and Nuclear Research (JIPNR) Sosny of Belarus; and (b) the IAEA coordinated research projects for accelerator driven systems (ADS). This activity is conducted as a part of the Russian Research Reactor Fuel Return (RRRFR) Program and the Global Threat Reduction Initiative (GTRI) of DOE/NNSA.

Gohar, Y.; Aliberti, G.; Nuclear Engineering Division

2009-08-31

141

Advanced vehicle systems assessment. Volume 4: Supporting analyses  

NASA Technical Reports Server (NTRS)

Volume 4 (Supporting Analyses) is part of a five-volume report, Advanced Vehicle Systems Assessment. Thirty-nine individuals, knowledgeable in advanced technology, were interviewed to obtain their preferences. Rankings were calculated for the eight groups they represented, using multiplicative and additive utility models. The four topics for consideration were: (1) preferred range for various battery technologies; (2) preferred battery technology for each of a variety of travel ranges; (3) most promising battery technology, vehicle range combination; and (4) comparison of the most preferred electric vehicle with the methanol-fuled, spark-ignition engine vehicle and with the most preferred of the hybrid vehicles.

Hardy, K.

1985-01-01

142

A graphical representation of protein based on a novel iterated function system  

NASA Astrophysics Data System (ADS)

In this article, a novel family of iterated function system (IFS) was introduced to outline a 2D graphical representation of protein sequences, which incorporates with various physicochemical properties of amino acids. Then a mathematical description was suggested to quantificationally compare the similarities and dissimilarities of protein sequences from their 2D curves. Based on this method, similarities/dissimilarities were compared among sequences of the ND5 proteins of nine different species, as well as sequences of eight ND6 proteins. The phylogenetic tree of the nine ND5 proteins was constructed according to Fuzzy cluster analysis. By correlation analysis, the ClustalW results were compared with our similarity/dissimilarity results and other graphical representation results to demonstrate the effectiveness of our approach.

Ma, Tingting; Liu, Yuxin; Dai, Qi; Yao, Yuhua; He, Ping-an

2014-06-01

143

Tetration: an iterative approach  

E-print Network

A matrix approach to continuous iteration is proposed for general formal series. It leads, in particular, to an order{to{order iteration of the exponential function, and consequently to an algorithmic approach to tetration. Lower{order approximations suggest that tetration may come to be of great interest for the description of involved dynamical systems.

R. Aldrovandi

2014-10-14

144

INVESTIGATION OF A TEST LOOP FOR THE COOLING SYSTEM OF THE ITER TF COIL UNDER PULSED HEAT LOAD  

SciTech Connect

CEA is involved in the design of the cooling scheme of the future ITER tokamak. Pulsed operation of ITER will result in heat load variations (which refrigerators have difficulties to cope with). A load smoothing device has been proposed by the ITER team which needs to be validated. To do this, a scaled-down experiment (hereafter also called model) has been proposed and studied in the framework of an EFDA sub-task. This paper presents the test loop dimensioning and the preliminary design for constructing the model. The choice of the relevant design criteria had to be defined so as to obtain in fine a geometric ratio between the ITER system and the model. It is shown that this ratio is then applicable for the mass flow rates as well as the different volumes (heat exchanger, pipes,...) existing on ITER and on the proposed experimental model. Details of the scaling, model design and 3D views corresponding to this preliminary study are presented in this paper.

Rousset, B.; Girard, A.; Maze, S.; Poncet, J. M.; Roussel, P. [DRFMC/SBT/Commissariat a l'Energie Atomique (CEA), Grenoble, 38054 (France); Kalinin, V. [ITER, Cadarache (France); Murdoch, D.; Sanmarti, M. [European Fusion Development Agreement (EFDA), Garching, Germany/Barcelona (Spain)

2008-03-16

145

Unsteady Analyses of Valve Systems in Rocket Engine Testing Environments  

NASA Technical Reports Server (NTRS)

This paper discusses simulation technology used to support the testing of rocket propulsion systems by performing high fidelity analyses of feed system components. A generalized multi-element framework has been used to perform simulations of control valve systems. This framework provides the flexibility to resolve the structural and functional complexities typically associated with valve-based high pressure feed systems that are difficult to deal with using traditional Computational Fluid Dynamics (CFD) methods. In order to validate this framework for control valve systems, results are presented for simulations of a cryogenic control valve at various plug settings and compared to both experimental data and simulation results obtained at NASA Stennis Space Center. A detailed unsteady analysis has also been performed for a pressure regulator type control valve used to support rocket engine and component testing at Stennis Space Center. The transient simulation captures the onset of a modal instability that has been observed in the operation of the valve. A discussion of the flow physics responsible for the instability and a prediction of the dominant modes associated with the fluctuations is presented.

Shipman, Jeremy; Hosangadi, Ashvin; Ahuja, Vineet

2004-01-01

146

Adapting iterative algorithms for solving large sparse linear systems for efficient use on the CDC CYBER 205  

NASA Technical Reports Server (NTRS)

Adapting and designing mathematical software to achieve optimum performance on the CYBER 205 is discussed. Comments and observations are made in light of recent work done on modifying the ITPACK software package and on writing new software for vector supercomputers. The goal was to develop very efficient vector algorithms and software for solving large sparse linear systems using iterative methods.

Kincaid, D. R.; Young, D. M.

1984-01-01

147

Convergence Analysis and Numerical Study of a Fixed-Point Iterative Method for Solving Systems of Nonlinear Equations  

PubMed Central

We present a fixed-point iterative method for solving systems of nonlinear equations. The convergence theorem of the proposed method is proved under suitable conditions. In addition, some numerical results are also reported in the paper, which confirm the good theoretical properties of our approach. PMID:24795537

Huang, Na

2014-01-01

148

Development of high temperature superconductor current leads for 70 kA [ITER-FEAT coil system  

Microsoft Academic Search

The Forschungszentrum Karlsruhe (FZK) and the Centre de Recherches en Physique des Plasmas (CRPP) are working on a joint development program to construct and test a 70 kA current lead using High Temperature Superconductors (HTS) for the Toroidal Field (TF) coil system of the International Thermonuclear Experimental Reactor, ITER-FEAT. This program follows the development program of an HTS current lead

R. Heller; G. Friesinger; A. M. Fuchs; R. Wesche

2002-01-01

149

Fusion Engineering and Design 3940 (1998) 859864 Tritium processing system for the ITER Li/V Blanket  

E-print Network

Fusion Engineering and Design 39­40 (1998) 859­864 Tritium processing system for the ITER Li-sufficiency, the tritium breeding, recovery and processing have to be demonstrated. The tritium produced in the blanket has to be processed to a purity which can be used for refuelling. All these functions need to be accomplished so

Abdou, Mohamed

150

High voltage tests of the ITER toroidal field model coil insulation system  

Microsoft Academic Search

A superconducting Toroidal Field Model Coil (TFMC) was developed by the European Home Team within the framework of the R&D program of the International Thermonuclear Experimental Reactor (ITER) and is presently tested in the TOSKA facility of the Forschungszentrum Karlsruhe. To withstand the Lorentz forces the 98 turns of the ITER TFMC are divided into 10 pancakes, embedded in five

Stefan Fink; Albert Ulbricht; Harald Fillunger; Alex Bourquard; Michel Prevot

2002-01-01

151

Evaluation of static mixer flow enhancements for cryogenic viscous compressor prototype for ITER vacuum system  

SciTech Connect

As part of the U.S. ITER contribution to the vacuum systems for the ITER fusion project, a cryogenic viscous compressor (CVC) is being designed and fabricated to cryopump hydrogenic gases in the torus and neutral beam exhaust streams and to regenerate the collected gases to controlled pressures such that they can be mechanically pumped with controlled flows to the tritium reprocessing facility. One critical element of the CVC design that required additional investigation was the determination of flow rates of the low pressure (up to 1000 Pa) exhaust stream that would allow for complete pumping of hydrogenic gases while permitting trace levels of helium to pass through the CVC to be pumped by conventional vacuum pumps. A sub-scale prototype test facility was utilized to determine the effectiveness of a static mixer pump tube concept, which consisted of a series of rotated twisted elements brazed into a 2-mm thick, 5-cm diameter stainless steel tube. Cold helium gas flow provided by a dewar and helium transfer line was used to cool the exterior of the static mixer pump tube. Deuterium gas was mixed with helium gas through flow controllers at different concentrations while the composition of the exhaust gas was monitored with a Penning gauge and optical spectrometer to determine the effectiveness of the static mixer. It was found that with tube wall temperatures between 6 K and 9 K, the deuterium gas was completely cryopumped and only helium passed through the tube. These results have been used to design the cooling geometry and the static mixer pump tubes in the full-scale CVC prototype.

Duckworth, Robert C.; Baylor, Larry R.; Meitner, Steven J.; Combs, Stephen K.; Ha, Tam; Morrow, Michael; Biewer, T. [Fusion and Materials for Nuclear System Division, Oak Ridge National Laboratory, Oak Ridge (United States); Rasmussen, David A.; Hechler, Michael P. [U.S. ITER Project Office, Oak Ridge National Laboratory, Oak Ridge (United States); Pearce, Robert J. H.; Dremel, Mattias [ITER Organization, 13115 St. Paul-lez-Durance (France); Boissin, J.-C. [Consultant, Grenoble (France)

2014-01-29

152

Nuclear systems and testing programs for ITER. Progress report for FY 1998  

SciTech Connect

The effort during this performance period focused on a number of TBWG activities (including test module design and analysis) that were identified and agreed upon (in the presence of the ITER Director and Deputy Director) at TBWG-4. These include: (a) DEMO test module design and performance analysis under pulsed operation; (b) Test program operation plan; (c) Test port design and analysis; (d) Decay heat calculations and safety analysis; (e) Further discussion among the parties to define collaboratory on R and D for the test program as well as possible collaboration on the construction and operation of test articles; (f) Remote handling and ancillary equipment; (g) Criteria for qualifying a blanket module or submodule for actual insertion and testing in ITER; (h) Definition of test module instrumentation and verification of capability to perform in the ITER fusion environment (magnetic field, radiation, heating, etc.); and (i) Analysis to show that the results to be obtained from the test modules as designed can be extrapolated to DEMO and reactor conditions (e.g., higher wall loads and the need to demonstrate tritium self-sufficiency). The main achievements during this performance period include: (1) updating and finalizing the US DDDs for the ITER Blanket Program to form part of the ITER Final Design Report (FDR). Specific revisions were in response to the minimal lithium volume test blanket design requirements and safety impact and (2) evaluating the feasibility of the US test program, including instrumentation and the benefits of the ITER test program. Details of this assessment, including solid breeder and liquid breeder blanket test plans, are documented in UCLA-IFNT-13 (attached). In addition, dose mapping calculations were performed for the ITER Building, including equipment and layout of coolant pipes/heat exchangers. A report on ITER Building dose calculations was sent to UD ITER management and to the Garching Task Coordinator in April, 1998. The report entitled Three-Dimensional Calculations of ITER Building Dose Rate Profiles and Assessment of Accessibility Inside the Building During Operation and After Shutdown of ITER can be located through ITER Reference Number of ITER Task S 62 TD 12, ID No: D325 ITER/US/98/S62TD12-D325 UCLA-FNT-100 UCLA-ENG-98-190.

NONE

1998-12-31

153

Integrated safety analysis code system (ISAS) application for accident sequence analyses  

Microsoft Academic Search

In the frame of the ITER Task ‘Reference Accident Sequences’, two accident sequences have been assessed to demonstrate the effectiveness of the use of integrated safety analysis code system (ISAS). The first one is a loss of coolant event in the divertor primary heat transfer system (DV PHTS) towards the vacuum vessel containment during normal plasma burn; the second one

M. T Porfiri; G Cambi

2000-01-01

154

Design of Electron Cyclotron Heating and Current Drive System of ITER  

SciTech Connect

Since the end of EDA, the design of the Electron Cyclotron Heating and Current Drive (ECH and CD) system has been modified to respond to progress in physics understanding and change of interface conditions. Nominal RF power of 20 MW is shared by four upper launchers or one equatorial launcher RF beams are steered by front steering mirrors providing wide sweeping angle for the RF beam. DC high voltage power supply may be composed of IGBT pulse step modulators because of high frequency modulation and design flexibility to three different types of 170 GHz gyrotrons provided by three parties. The RF power from the 170 GHz gyrotron is transmitted to the launcher by 63.5 mm{phi} corrugated waveguide line and remotely switched by a waveguide switch between the upper launcher and the equatorial launcher. The ECH and CD system has also a start-up sub-system for assist of initial discharge composed of three 127.5 GHz gyrotrons and a dedicated DC high voltage power supply. Three of transmission lines are shared between 170 GHz gyrotron and 127.5 GHz gyrotron so as to inject RF beam for the start-up through the equatorial launcher. R and Ds of components for high power long pulse and mirror steering mechanism have been on-going in the parties to establish a reliable ITER ECH and CD system.

Kobayashi, N. [ITER, Cadarache (France); Bigelow, T.; Rasmussen, D. [ORNL, Oak Ridge (United States); Bonicelli, T.; Ramponi, G.; Saibene, G. [EFDA, Garching (Germany); Cirant, S. [ENEA-CNR, Milan (Italy); Denisov, G. [IAP, Nizhny Novgorod (Russian Federation); Heidinger, R.; Piosczyk, B. [FZK, Karlsruhe (Germany); Henderson, M.; Hogge, J.-P.; Thumm, M.; Tran, M. Q. [CRPP, Lausanne (Switzerland); Rao, S. L. [IPR, Bhat (India); Sakamoto, K.; Takahashi, K. [JAEA, Naka (Japan); Temkin, R. J. [MIT PSFC, Cambridge (United States); Verhoeven, A. G. A. [FOM IPP, Rijnhuizen (Netherlands); Zohm, H. [MPI IPP, Garching (Germany)

2007-09-28

155

GoldenBraid: An Iterative Cloning System for Standardized Assembly of Reusable Genetic Modules  

PubMed Central

Synthetic Biology requires efficient and versatile DNA assembly systems to facilitate the building of new genetic modules/pathways from basic DNA parts in a standardized way. Here we present GoldenBraid (GB), a standardized assembly system based on type IIS restriction enzymes that allows the indefinite growth of reusable gene modules made of standardized DNA pieces. The GB system consists of a set of four destination plasmids (pDGBs) designed to incorporate multipartite assemblies made of standard DNA parts and to combine them binarily to build increasingly complex multigene constructs. The relative position of type IIS restriction sites inside pDGB vectors introduces a double loop (“braid”) topology in the cloning strategy that allows the indefinite growth of composite parts through the succession of iterative assembling steps, while the overall simplicity of the system is maintained. We propose the use of GoldenBraid as an assembly standard for Plant Synthetic Biology. For this purpose we have GB-adapted a set of binary plasmids for A. tumefaciens-mediated plant transformation. Fast GB-engineering of several multigene T-DNAs, including two alternative modules made of five reusable devices each, and comprising a total of 19 basic parts are also described. PMID:21750718

Sarrion-Perdigones, Alejandro; Falconi, Erica Elvira; Zandalinas, Sara I.; Juárez, Paloma; Fernández-del-Carmen, Asun; Granell, Antonio; Orzaez, Diego

2011-01-01

156

Data-driven control for relative degree systems via iterative learning.  

PubMed

Iterative learning control (ILC) is a kind of effective data-driven method that is developed based on online and/or offline input/output data. The main purpose of this paper is to supply a unified 2-D analysis approach for both continuous-time and discrete-time ILC systems with relative degree. It is shown that the 2-D Roesser system framework can be established for general ILC systems regardless of relative degree, under which convergence conditions can be provided to guarantee both asymptotic stability and monotonic convergence of the ILC processes. In particular, conditions for the monotonic convergence of ILC can be given in terms of linear matrix inequalities, and formulas for the updating law can be derived simultaneously. Simulation results are presented to illustrate the effectiveness of ILC determined through the 2-D design approach in dealing with the higher order relative degree problem of ILC systems, as well as the robustness of such ILC against uncertainties. PMID:22113776

Meng, Deyuan; Jia, Yingmin; Du, Junping; Yu, Fashan

2011-12-01

157

2D Iterative Image Reconstruction in Dual Head Micro PET with Lookup System Matrix  

NASA Astrophysics Data System (ADS)

The quality of the reconstructed images in small animal studies through micro PET depends largely on the complexity of the model to determine the system matrix. Each system matrix element corresponds to the probability of the detection of an annihilation event inside the field of view (FOV). Monte Carlo methods allow us to simulate physical process not included in the analytical model, such as non collinearity of gamma rays, positron range effect, interaction of incident gamma rays with the scintillator crystal (including attenuation and Compton scattering effect), etc. We have evaluated the elements of one of the quadrants of the transaxial central plane. The reflection and rotation symmetries have been use to reduce the system matrix calculation time. We use the 2D-Maximum Likelihood Expectation Maximization (MLEM) iterative method with Single Slice Rebinning (SSRB) technique to reconstruct a point source and Derenzo-like phantom images. To evaluate the performance of the Micro PET system, the merit curves and the MOBY mouse phantom reconstruction were obtained.

Ramos, J. M.; Moreno, E. B.; Salazar, H. I.; Martínez, O. B.

2010-12-01

158

Synthesis of Trigeneration Systems: Sensitivity Analyses and Resilience  

PubMed Central

This paper presents sensitivity and resilience analyses for a trigeneration system designed for a hospital. The following information is utilized to formulate an integer linear programming model: (1) energy service demands of the hospital, (2) technical and economical characteristics of the potential technologies for installation, (3) prices of the available utilities interchanged, and (4) financial parameters of the project. The solution of the model, minimizing the annual total cost, provides the optimal configuration of the system (technologies installed and number of pieces of equipment) and the optimal operation mode (operational load of equipment, interchange of utilities with the environment, convenience of wasting cogenerated heat, etc.) at each temporal interval defining the demand. The broad range of technical, economic, and institutional uncertainties throughout the life cycle of energy supply systems for buildings makes it necessary to delve more deeply into the fundamental properties of resilient systems: feasibility, flexibility and robustness. The resilience of the obtained solution is tested by varying, within reasonable limits, selected parameters: energy demand, amortization and maintenance factor, natural gas price, self-consumption of electricity, and time-of-delivery feed-in tariffs. PMID:24453881

Carvalho, Monica; Lozano, Miguel A.; Ramos, José; Serra, Luis M.

2013-01-01

159

Reproducible analyses of microbial food for advanced life support systems  

NASA Technical Reports Server (NTRS)

The use of yeasts in controlled ecological life support systems (CELSS) for microbial food regeneration in space required the accurate and reproducible analysis of intracellular carbohydrate and protein levels. The reproducible analysis of glycogen was a key element in estimating overall content of edibles in candidate yeast strains. Typical analytical methods for estimating glycogen in Saccharomyces were not found to be entirely aplicable to other candidate strains. Rigorous cell lysis coupled with acid/base fractionation followed by specific enzymatic glycogen analyses were required to obtain accurate results in two strains of Candida. A profile of edible fractions of these strains was then determined. The suitability of yeasts as food sources in CELSS food production processes is discussed.

Petersen, Gene R.

1988-01-01

160

GPU computing with Kaczmarz’s and other iterative algorithms for linear systems  

PubMed Central

The graphics processing unit (GPU) is used to solve large linear systems derived from partial differential equations. The differential equations studied are strongly convection-dominated, of various sizes, and common to many fields, including computational fluid dynamics, heat transfer, and structural mechanics. The paper presents comparisons between GPU and CPU implementations of several well-known iterative methods, including Kaczmarz’s, Cimmino’s, component averaging, conjugate gradient normal residual (CGNR), symmetric successive overrelaxation-preconditioned conjugate gradient, and conjugate-gradient-accelerated component-averaged row projections (CARP-CG). Computations are preformed with dense as well as general banded systems. The results demonstrate that our GPU implementation outperforms CPU implementations of these algorithms, as well as previously studied parallel implementations on Linux clusters and shared memory systems. While the CGNR method had begun to fall out of favor for solving such problems, for the problems studied in this paper, the CGNR method implemented on the GPU performed better than the other methods, including a cluster implementation of the CARP-CG method. PMID:20526446

Elble, Joseph M.; Sahinidis, Nikolaos V.; Vouzis, Panagiotis

2009-01-01

161

Modeling and Analysis of Alternative Concept of ITER Vacuum Vessel Primary Heat Transfer System  

SciTech Connect

A RELAP5-3D model of the ITER (Latin for the way ) vacuum vessel (VV) primary heat transfer system has been developed to evaluate a proposed design change that relocates the heat exchangers (HXs) from the exterior of the tokamak building to the interior. This alternative design protects the HXs from external hazards such as wind, tornado, and aircraft crash. The proposed design integrates the VV HXs into a VV pressure suppression system (VVPSS) tank that contains water to condense vapour in case of a leak into the plasma chamber. The proposal is to also use this water as the ultimate sink when removing decay heat from the VV system. The RELAP5-3D model has been run under normal operating and abnormal (decay heat) conditions. Results indicate that this alternative design is feasible, with no effects on the VVPSS tank under normal operation and with tank temperature and pressure increasing under decay heat conditions resulting in a requirement to remove steam generated if the VVPSS tank low pressure must be maintained.

Carbajo, Juan J [ORNL; Yoder Jr, Graydon L [ORNL; Dell'Orco, Giovanni [ITER Organization, Saint Paul Lez Durance, France; Curd, Warren [ITER Organization, Saint Paul Lez Durance, France; Kim, Seokho H [ORNL

2010-01-01

162

Adaptive switching detection algorithm for iterative-MIMO systems to enable power savings  

NASA Astrophysics Data System (ADS)

This paper attempts to tackle one of the challenges faced in soft input soft output Multiple Input Multiple Output (MIMO) detection systems, which is to achieve optimal error rate performance with minimal power consumption. This is realized by proposing a new algorithm design that comprises multiple thresholds within the detector that, in real time, specify the receiver behavior according to the current channel in both slow and fast fading conditions, giving it adaptivity. This adaptivity enables energy savings within the system since the receiver chooses whether to accept or to reject the transmission, according to the success rate of detecting thresholds. The thresholds are calculated using the mutual information of the instantaneous channel conditions between the transmitting and receiving antennas of iterative-MIMO systems. In addition, the power saving technique, Dynamic Voltage and Frequency Scaling, helps to reduce the circuit power demands of the adaptive algorithm. This adaptivity has the potential to save up to 30% of the total energy when it is implemented on Xilinx®Virtex-5 simulation hardware. Results indicate the benefits of having this "intelligence" in the adaptive algorithm due to the promising performance-complexity tradeoff parameters in both software and hardware codesign simulation.

Tadza, N.; Laurenson, D.; Thompson, J. S.

2014-11-01

163

Wide-angle ITER-prototype tangential infrared and visible viewing system for DIII-Da)  

NASA Astrophysics Data System (ADS)

An imaging system with a wide-angle tangential view of the full poloidal cross-section of the tokamak in simultaneous infrared and visible light has been installed on DIII-D. The optical train includes three polished stainless steel mirrors in vacuum, which view the tokamak through an aperture in the first mirror, similar to the design concept proposed for ITER. A dichroic beam splitter outside the vacuum separates visible and infrared (IR) light. Spatial calibration is accomplished by warping a CAD-rendered image to align with landmarks in a data image. The IR camera provides scrape-off layer heat flux profile deposition features in diverted and inner-wall-limited plasmas, such as heat flux reduction in pumped radiative divertor shots. Demonstration of the system to date includes observation of fast-ion losses to the outer wall during neutral beam injection, and shows reduced peak wall heat loading with disruption mitigation by injection of a massive gas puff.

Lasnier, C. J.; Allen, S. L.; Ellis, R. E.; Fenstermacher, M. E.; McLean, A. G.; Meyer, W. H.; Morris, K.; Seppala, L. G.; Crabtree, K.; Van Zeeland, M. A.

2014-11-01

164

Wide-angle ITER-prototype tangential infrared and visible viewing system for DIII-D  

SciTech Connect

An imaging system with a wide-angle tangential view of the full poloidal cross-section of the tokamak in simultaneous infrared and visible light has been installed on DIII-D. The optical train includes three polished stainless steel mirrors in vacuum, which view the tokamak through an aperture in the first mirror, similar to the design concept proposed for ITER. A dichroic beam splitter outside the vacuum separates visible and infrared (IR) light. Spatial calibration is accomplished by warping a CAD-rendered image to align with landmarks in a data image. The IR camera provides scrape-off layer heat flux profile deposition features in diverted and inner-wall-limited plasmas, such as heat flux reduction in pumped radiative divertor shots. Demonstration of the system to date includes observation of fast-ion losses to the outer wall during neutral beam injection, and shows reduced peak wall heat loading with disruption mitigation by injection of a massive gas puff.

Lasnier, C. J., E-mail: lasnier@LLNL.gov; Allen, S. L.; Ellis, R. E.; Fenstermacher, M. E.; McLean, A. G.; Meyer, W. H.; Morris, K.; Seppala, L. G. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808 (United States); Crabtree, K. [College of Optics, University of Arizona, Tucson, Arizona 85721 (United States); Van Zeeland, M. A. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States)

2014-11-15

165

System matrix analysis for sparse-view iterative image reconstruction in X-ray CT.  

PubMed

Iterative image reconstruction (IIR) with sparsity-exploiting methods, such as total variation (TV) minimization, used for investigations in compressive sensing (CS) claim potentially large reductions in sampling requirements. Quantifying this claim for computed tomography (CT) is non-trivial, as both the singularity of undersampled reconstruction and the sufficient view number for sparse-view reconstruction are ill-defined. In this paper, the singular value decomposition method is used to study the condition number and singularity of the system matrix and the regularized matrix. An estimation method of the empirical lower bound is proposed, which is helpful for estimating the number of projection views required for exact reconstruction. Simulation studies show that the singularity of the system matrices for different projection views is effectively reduced by regularization. Computing the condition number of a regularized matrix is necessary to provide a reference for evaluating the singularity and recovery potential of reconstruction algorithms using regularization. The empirical lower bound is helpful for estimating the projections view number with a sparse reconstruction algorithm. PMID:25567402

Wang, Linyuan; Zhang, Hanming; Cai, Ailong; Li, Yongl; Yan, Bin; Li, Lei; Hu, Guoen

2015-01-01

166

Wall conditioning on ITER  

NASA Astrophysics Data System (ADS)

Like all tokamaks, ITER will require wall conditioning systems and strategies for successful operation from the point of view of plasma-facing surface preparation. Unlike today's devices however, ITER will have to manage large quantities of tritium fuel, imposing on wall conditioning a major responsibility for tritium inventory control. It will also feature the largest plasma-facing beryllium surface ever used in a tokamak and its high duty cycle and long pulse are expected to lead to the rapid formation of deposited layers in which tritium can accumulate. This paper summarises the currently planned ITER wall conditioning systems and describes the strategy for their use throughout exploitation of the device.

Shimada, Michiya; Pitts, Richard A.

2011-08-01

167

Bounds on the map threshold of iterative decoding systems with erasure noise  

E-print Network

-accumulate (IRA) and accumulaterepeataccumulate (ARA) code ensembles are analyzed on the binary erasure channel (BEC). Next, the joint iterative decoding of LDPC codes is studied on the dicode erasure channel (DEC). The DEC is a two-state intersymbol...

Wang, Chia-Wen

2008-10-10

168

Qualification of the US made conductors for ITER TF magnet system  

SciTech Connect

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, N; Hatfield, D; Miller, J; Bruzzone, P; Stepanov, B; Seber, B

2009-10-08

169

Qualification of the US Made Conductors for ITER TF Magnet System  

SciTech Connect

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

2010-01-01

170

Modifying the Medical Research Council grading system through Rasch analyses  

PubMed Central

The Medical Research Council grading system has served through decades for the evaluation of muscle strength and has been recognized as a cardinal feature of daily neurological, rehabilitation and general medicine examination of patients, despite being respectfully criticized due to the unequal width of its response options. No study has systematically examined, through modern psychometric approach, whether physicians are able to properly use the Medical Research Council grades. The objectives of this study were: (i) to investigate physicians’ ability to discriminate among the Medical Research Council categories in patients with different neuromuscular disorders and with various degrees of weakness through thresholds examination using Rasch analysis as a modern psychometric method; (ii) to examine possible factors influencing physicians’ ability to apply the Medical Research Council categories through differential item function analyses; and (iii) to examine whether the widely used Medical Research Council 12 muscles sum score in patients with Guillain–Barré syndrome and chronic inflammatory demyelinating polyradiculoneuropathy would meet Rasch model's expectations. A total of 1065 patients were included from nine cohorts with the following diseases: Guillain–Barré syndrome (n?=?480); myotonic dystrophy type-1 (n?=?169); chronic inflammatory demyelinating polyradiculoneuropathy (n?=?139); limb-girdle muscular dystrophy (n?=?105); multifocal motor neuropathy (n?=?102); Pompe's disease (n?=?62) and monoclonal gammopathy of undetermined related polyneuropathy (n?=?8). Medical Research Council data of 72 muscles were collected. Rasch analyses were performed on Medical Research Council data for each cohort separately and after pooling data at the muscle level to increase category frequencies, and on the Medical Research Council sum score in patients with Guillain–Barré syndrome and chronic inflammatory demyelinating polyradiculoneuropathy. Disordered thresholds were demonstrated in 74–79% of the muscles examined, indicating physicians’ inability to discriminate between most Medical Research Council categories. Factors such as physicians’ experience or illness type did not influence these findings. Thresholds were restored after rescoring the Medical Research Council grades from six to four options (0, paralysis; 1, severe weakness; 2, slight weakness; 3, normal strength). The Medical Research Council sum score acceptably fulfilled Rasch model expectations after rescoring the response options and creating subsets to resolve local dependency and item bias on diagnosis. In conclusion, a modified, Rasch-built four response category Medical Research Council grading system is proposed, resolving clinicians’ inability to differentiate among its original response categories and improving clinical applicability. A modified Medical Research Council sum score at the interval level is presented and is recommended for future studies in Guillain–Barré syndrome and chronic inflammatory demyelinating polyradiculoneuropathy. PMID:22189568

Vanhoutte, Els Karla; Faber, Catharina Gerritdina; van Nes, Sonja Ingrid; Jacobs, Bart Casper; van Doorn, Pieter Antoon; van Koningsveld, Rinske; Cornblath, David Reid; van der Kooi, Anneke Jelly; Cats, Elisabeth Aviva; van den Berg, Leonard Hendrik; Notermans, Nicolette Claudia; van der Pol, Willem Lodewijk; Hermans, Mieke Catharina Elisabeth; van der Beek, Nadine Anna Maria Elisabeth; Gorson, Kenneth Craig; Eurelings, Marijke; Engelsman, Jeroen; Boot, Hendrik; Meijer, Ronaldus Jacobus; Lauria, Giuseppe; Tennant, Alan

2012-01-01

171

Nested iteration and first-order systems least squares for incompressible resistive magnetohydrodynamics  

NASA Astrophysics Data System (ADS)

Magnetohydrodynamics (MHD) is a fluid theory that describes Plasma Physics by treating the plasma as a fluid of charged particles. Hence, the equations that describe the plasma form a nonlinear system that couples Navier-Stokes with Maxwell's equations. This thesis develops a nested-iteration-Newton-FOSLS-AMG approach to solve this type of system. For full efficiency, most of the work is done on coarse grids, including most of the linearizations. We show that at most one Newton step and a few V-cycles are all that is needed on the finest grid. Here, we describe how the FOSLS method can be applied to incompressible resistive MHD and how it can be used to solve these MHD problems efficiently in a full multigrid approach. An algorithm is developed that uses the a posteriori error estimates of the FOSLS formulation to determine how well the system is being solved and what needs to be done to get the most accuracy per computational cost. In addition, various aspects of the algorithm are analyzed, including a timestepping analysis to confirm stability of the numerical scheme as well as the benefits of an efficiency based adaptive mesh refinement method. A 3D steady state and a reduced 2D time-dependent test problem are studied. The latter equations can simulate a "large aspect-ratio" tokamak. The goal is to resolve as much physics from the test problems with the least amount of computational work. This thesis shows that this is achieved in a few dozen work units (a work unit is the cost of one fine grid residual evaluation).

Adler, James Haley

172

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

SciTech Connect

U.S. ITER is responsible for the design, engineering, and procurement of the Tokamak Cooling Water System (TCWS). The TCWS transfers heat generated in the Tokamak to cooling water during nominal pulsed operation 850 MW at up to 150 C and 4.2 MPa water pressure. This water contains radionuclides because impurities (e.g., tritium) diffuse from in-vessel components and the vacuum vessel by water baking at 200 240 C at up to 4.4MPa, and corrosion products become activated by neutron bombardment. The system is designated as safety important class (SIC) and will be fabricated to comply with the French Order concerning nuclear pressure equipment (December 2005) and the EU Pressure Equipment Directive using ASME Section VIII, Div 2 design codes. The complexity of the TCWS design and fabrication presents unique challenges. Conceptual design of this one-of-a-kind cooling system has been completed with several issues that need to be resolved to move to next stage of the design. Those issues include flow balancing between over hundreds of branch pipelines in parallel to supply cooling water to blankets, determination of optimum flow velocity while minimizing the potential for cavitation damage, design for freezing protection for cooling water flowing through cryostat (freezing) environment, requirements for high-energy piping design, and electromagnetic impact to piping and components. Although the TCWS consists of standard commercial components such as piping with valves and fittings, heat exchangers, and pumps, complex requirements present interesting design challenges. This paper presents a brief description of TCWS conceptual design and critical design issues that need to be resolved.

Kim, Seokho H [ORNL] [ORNL; Berry, Jan [ORNL] [ORNL

2011-01-01

173

Comparative Genomic Analyses of the Bacterial Phosphotransferase System  

PubMed Central

We report analyses of 202 fully sequenced genomes for homologues of known protein constituents of the bacterial phosphoenolpyruvate-dependent phosphotransferase system (PTS). These included 174 bacterial, 19 archaeal, and 9 eukaryotic genomes. Homologues of PTS proteins were not identified in archaea or eukaryotes, showing that the horizontal transfer of genes encoding PTS proteins has not occurred between the three domains of life. Of the 174 bacterial genomes (136 bacterial species) analyzed, 30 diverse species have no PTS homologues, and 29 species have cytoplasmic PTS phosphoryl transfer protein homologues but lack recognizable PTS permeases. These soluble homologues presumably function in regulation. The remaining 77 species possess all PTS proteins required for the transport and phosphorylation of at least one sugar via the PTS. Up to 3.2% of the genes in a bacterium encode PTS proteins. These homologues were analyzed for family association, range of protein types, domain organization, and organismal distribution. Different strains of a single bacterial species often possess strikingly different complements of PTS proteins. Types of PTS protein domain fusions were analyzed, showing that certain types of domain fusions are common, while others are rare or prohibited. Select PTS proteins were analyzed from different phylogenetic standpoints, showing that PTS protein phylogeny often differs from organismal phylogeny. The results document the frequent gain and loss of PTS protein-encoding genes and suggest that the lateral transfer of these genes within the bacterial domain has played an important role in bacterial evolution. Our studies provide insight into the development of complex multicomponent enzyme systems and lead to predictions regarding the types of protein-protein interactions that promote efficient PTS-mediated phosphoryl transfer. PMID:16339738

Barabote, Ravi D.; Saier, Milton H.

2005-01-01

174

Space-domain non-iterative approach for SPECT\\/CT systems considering attenuation and space-variant detector response  

Microsoft Academic Search

A quantitative analysis of emission planar image reconstruction from projections by an object dependent, exact, direct approach in the space-domain considering both object attenuation and space-variant impulse response of SPECT\\/CT systems is proposed. That approach is compared with iterative methods and non-object-dependent exact methods in both the space domain and the frequency one. Since the mean-projection precorrection method is the

Cosimo Imperiale; Alessio Imperiale

2007-01-01

175

Low-temperature tensile strength of the ITER-TF model coil insulation system after reactor irradiation  

Microsoft Academic Search

The windings of the superconducting magnet coils for the ITER-FEAT fusion device are affected by high mechanical stresses at cryogenic temperatures and by a radiation environment, which impose certain constraints especially on the insulating materials. A glass fiber reinforced plastic (GFRP) laminate, which consists of Kapton\\/R-glass-fiber reinforcement tapes, vacuum-impregnated in a DGEBA epoxy system, was used for the European toroidal

K Bittner-Rohrhofer; K Humer; H. W Weber

2002-01-01

176

Description of Transmutation Library for Fuel Cycle System Analyses  

SciTech Connect

This report documents the Transmutation Library that is used in Fuel Cycle System Analyses. This version replaces the 2008 version.[Piet2008] The Transmutation Library has the following objectives: • Assemble past and future transmutation cases for system analyses. • For each case, assemble descriptive information such as where the case was documented, the purpose of the calculation, the codes used, source of feed material, transmutation parameters, and the name of files that contain raw or source data. • Group chemical elements so that masses in separation and waste processes as calculated in dynamic simulations or spreadsheets reflect current thinking of those processes. For example, the CsSr waste form option actually includes all Group 1A and 2A elements. • Provide mass fractions at input (charge) and output (discharge) for each case. • Eliminate the need for either “fission product other” or “actinide other” while conserving mass. Assessments of waste and separation cannot use “fission product other” or “actinide other” as their chemical behavior is undefined. • Catalog other isotope-specific information in one place, e.g., heat and dose conversion factors for individual isotopes. • Describe the correlations for how input and output compositions change as a function of UOX burnup (for LWR UOX fuel) or fast reactor (FR) transuranic (TRU) conversion ratio (CR) for either FR-metal or FR-oxide. This document therefore includes the following sections: • Explanation of the data set information, i.e., the data that describes each case. In no case are all of the data presented in the Library included in previous documents. In assembling the Library, we return to raw data files to extract the case and isotopic data, into the specified format. • Explanation of which isotopes and elements are tracked. For example, the transition metals are tracked via the following: two Zr isotopes, Zr-other, Tc99, Tc-other, two Mo-Ru-Rh-Pd isotopes, Mo-Ru-Rh-Pd-other, four other specific TM isotopes, and TM-other. Mo-Ru-Rh-Pd are separated because their content constrains the loading of waste in glass, so we have to know the mass of those elements independent of others. • Rules for collapsing long lists of isotopes (~1000) to the 81 items in the library. For each tracked isotope, we define which short-lived isotopes’ mass (at t=0) is included with the mass of the tracked isotope at t=0, which short-lived radioactive progeny must be accounted for when the tracked isotope decays, and to which of the other 80 items the mass of the tracked isotope goes when it decays. • Explanation of where raw data files can be found on the fuel cycle data portal. • Explanation of generic cross section sets • Explanation of isotope-specific parameters such as heat and dose conversion factors • Explanation of the LWR UOX burnup and FR TRU CR correlations.

Steven J. Piet; Samuel E. Bays; Edward A. Hoffman

2010-08-01

177

Leveraging Anderson Acceleration for improved convergence of iterative solutions to transport systems  

NASA Astrophysics Data System (ADS)

In this note we demonstrate that using Anderson Acceleration (AA) in place of a standard Picard iteration can not only increase the convergence rate but also make the iteration more robust for two transport applications. We also compare the convergence acceleration provided by AA to that provided by moment-based acceleration methods. Additionally, we demonstrate that those two acceleration methods can be used together in a nested fashion. We begin by describing the AA algorithm. At this point, we will describe two application problems, one from neutronics and one from plasma physics, on which we will apply AA. We provide computational results which highlight the benefits of using AA, namely that we can compute solutions using fewer function evaluations, larger time-steps, and achieve a more robust iteration.

Willert, Jeffrey; Taitano, William T.; Knoll, Dana

2014-09-01

178

Information theoretic discrepancy based iterative reconstruction (IDIR) algorithm for dual energy x-ray systems  

NASA Astrophysics Data System (ADS)

In dual energy computed tomography (DECT), two sets of projection data are acquired using a couple of independent X-ray spectra. Since the attenuation characteristic of a material without a K-edge in a typical medical X-ray spectrum range is accurately described by the linear combination of two phenomena, which are the photoelectric attenuation and the Compton scatter, the DECT is theoretically capable of separating one material from another. However, the material decomposition (MD) is still a challenging problem in DECT, since two sets of sinograms from distinct X-ray spectra are not spatially aligned in practices. To avoid this problem, the MD is often achieved by a weighted summation of two reconstructed volumes that correspond to a couple of sets of projection data, which the monochromatic approximation is generally used in the reconstruction procedure. The accuracy of the MD, therefore, can be limited due to the erroneous ignorance of the energy dependency of the acquisition model. In this paper, we propose a novel algorithm, named information theoretic discrepancy based iterative reconstruction (IDIR) algorithm, for an accurate MD in dual energy X-ray systems. The generalized information theoretic discrepancy (GID) measure is newly employed as the objective value. Using particular features of the GID, a tractable objective function for the material-selective reconstruction is derived, which accounts the exact polychromatic model of transmission tomography. Since the spectral model of measured data is explicitly considered, the accurate MD is possible even for misaligned projections. In numerical experiments, the proposed method showed superior reconstruction performance over the conventional approach.

Jang, Kwang Eun; Lee, Jongha; Lee, Kangui; Sung, Younghun; Lee, SeungDeok

2012-03-01

179

All-electron KKR Calculations for Metallic Systems with Thousands of Atoms Per Cell via Sparse Matrix Iterative Solvers  

NASA Astrophysics Data System (ADS)

To perform electronic-structure calculations for inherently large systems, such as a quantum dots or interfaces like domain walls, we must perform the calculations over very large unit cells (10^4 to 10^8 atoms). For the inverse Green's function G-1, KKR methods typically solve for G by direct inversion. Using a screened, k-space hybrid KKR, we solve Dyson's equation for the Green's function using a reference state via G = Gref [ I - (t - tref) Gref]-1, scattering matrices t and tref are known and the non-Hermitian tensor Gref is chosen for convenience and sparsity [1]. The approach is O(N) for bandgap materials, whereas it is O(N^2) for metals but with a potentially large prefactor. Based upon Sparse Approximate Inverse (or SPAI) technique [2], we generalize the algorithm for complex, non-Hermitian matrices, then use the method as a preconditioner for the inversion to reduce the iteration counts (hence, reduce the prefactor) of the iterative Krylov-space inverses, such as TFQMR, to address large-scale metallic systems. Parallel iterative and energy contour solves are made also. We explore the numerical efficiency and scaling versus atoms per unit cells. [1] Smirnov and Johnson, Comp. Phys. Comm. 148, 74-80 (2002). [2] Grote and Huckle, SIAM J. Sci. Comput. 18, 8

Khan, Suffian; Alam, Aftab; Johnson, Duane

2009-03-01

180

Iterative Spatial Sequence Estimator for Multi-Group Space Time Trellis Coded Systems  

E-print Network

-Ghadhban, Maruf Mohammad, and B. Woerner Mobile and Portable Radio Research Group Virginia Tech E-Mail: {maruf with soft-input soft- output (SISO) maximum a posteriori (MAP) algorithm as the detection stage in the multi-group receiver. It will iterate and share soft information with the soft decoding stage. The remainder

Al-Ghadhban, Samir

181

Progress on the ITER H&CD EC Upper Launcher Steering-Mirror Control System  

Microsoft Academic Search

The ITER Heating and Current Drive Upper Launcher (H & CD EC UL) uses a pneumomechanical steering-mirror assembly (SMA) to steer the RF beams for their deposition in the appropriate location in the plasma to control magnetohydrodynamic activity (neoclassical tearing modes (NTMs) and sawtooth oscillations). For NTM stabilization, the mirror rotation needs to be controlled to an accuracy that is

Andrés Collazos; Robert Bertizzolo; Réné Chavan; Frédéric Dolizy; Federico Felici; Timothy P. Goodman; Mark A. Henderson; Jean-Daniel Landis; Francisco Sanchez

2010-01-01

182

Air pollution control system research: An iterative approach to developing affordable systems  

NASA Technical Reports Server (NTRS)

This paper describes a Strategic Environmental Research and Development Program (SERDP) funded project led jointly by the Marine Corps Multi-Commodity Maintenance Centers, and the Air and Energy Engineering Research Laboratory (AEERL) of the USEPA. The research focuses on paint booth exhaust minimization using recirculation, and on volatile organic compound (VOC) oxidation by the modules of a hybrid air pollution control system. The research team is applying bench, pilot and full scale systems to accomplish the goals of reduced cost and improved effectiveness of air treatment systems for paint booth exhaust.

Watt, Lewis C.; Cannon, Fred S.; Heinsohn, Robert J.; Spaeder, Timothy A.

1995-01-01

183

Microwave power transmission system studies. Volume 2: Introduction, organization, environmental and spaceborne systems analyses  

NASA Technical Reports Server (NTRS)

Introduction, organization, analyses, conclusions, and recommendations for each of the spaceborne subsystems are presented. Environmental effects - propagation analyses are presented with appendices covering radio wave diffraction by random ionospheric irregularities, self-focusing plasma instabilities and ohmic heating of the D-region. Analyses of dc to rf conversion subsystems and system considerations for both the amplitron and the klystron are included with appendices for the klystron covering cavity circuit calculations, output power of the solenoid-focused klystron, thermal control system, and confined flow focusing of a relativistic beam. The photovoltaic power source characteristics are discussed as they apply to interfacing with the power distribution flow paths, magnetic field interaction, dc to rf converter protection, power distribution including estimates for the power budget, weights, and costs. Analyses for the transmitting antenna consider the aperture illumination and size, with associated efficiencies and ground power distributions. Analyses of subarray types and dimensions, attitude error, flatness, phase error, subarray layout, frequency tolerance, attenuation, waveguide dimensional tolerances, mechanical including thermal considerations are included. Implications associated with transportation, assembly and packaging, attitude control and alignment are discussed. The phase front control subsystem, including both ground based pilot signal driven adaptive and ground command approaches with their associated phase errors, are analyzed.

Maynard, O. E.; Brown, W. C.; Edwards, A.; Haley, J. T.; Meltz, G.; Howell, J. M.; Nathan, A.

1975-01-01

184

Gamma ray spectrometer for ITER  

NASA Astrophysics Data System (ADS)

Gamma diagnostics is considered to be primary for the confined ?-particles and runaway electrons measurements on ITER. The gamma spectrometer will be embedded into a neutron dump of the ITER Neutral Particle Analyzer diagnostic complex. It will supplement NPA measurements on the fuel isotope ratio and confined alphas/fast ions. In this paper an update on ITER gamma spectrometer developments is given. A new geometry of the system is described and detailed analysis of expected signals for the spectrometer is presented.

Gin, D.; Chugunov, I.; Shevelev, A.; Khilkevitch, E.; Doinikov, D.; Naidenov, V.; Pasternak, A.; Polunovsky, I.; Kiptily, V.

2014-08-01

185

Statistical model based iterative reconstruction (MBIR) in clinical CT systems: Experimental assessment of noise performance  

SciTech Connect

Purpose: To reduce radiation dose in CT imaging, the statistical model based iterative reconstruction (MBIR) method has been introduced for clinical use. Based on the principle of MBIR and its nonlinear nature, the noise performance of MBIR is expected to be different from that of the well-understood filtered backprojection (FBP) reconstruction method. The purpose of this work is to experimentally assess the unique noise characteristics of MBIR using a state-of-the-art clinical CT system. Methods: Three physical phantoms, including a water cylinder and two pediatric head phantoms, were scanned in axial scanning mode using a 64-slice CT scanner (Discovery CT750 HD, GE Healthcare, Waukesha, WI) at seven different mAs levels (5, 12.5, 25, 50, 100, 200, 300). At each mAs level, each phantom was repeatedly scanned 50 times to generate an image ensemble for noise analysis. Both the FBP method with a standard kernel and the MBIR method (Veo{sup ®}, GE Healthcare, Waukesha, WI) were used for CT image reconstruction. Three-dimensional (3D) noise power spectrum (NPS), two-dimensional (2D) NPS, and zero-dimensional NPS (noise variance) were assessed both globally and locally. Noise magnitude, noise spatial correlation, noise spatial uniformity and their dose dependence were examined for the two reconstruction methods. Results: (1) At each dose level and at each frequency, the magnitude of the NPS of MBIR was smaller than that of FBP. (2) While the shape of the NPS of FBP was dose-independent, the shape of the NPS of MBIR was strongly dose-dependent; lower dose lead to a “redder” NPS with a lower mean frequency value. (3) The noise standard deviation (?) of MBIR and dose were found to be related through a power law of ????(dose){sup ??} with the component ? ? 0.25, which violated the classical ????(dose){sup ?0.5} power law in FBP. (4) With MBIR, noise reduction was most prominent for thin image slices. (5) MBIR lead to better noise spatial uniformity when compared with FBP. (6) A composite image generated from two MBIR images acquired at two different dose levels (D1 and D2) demonstrated lower noise than that of an image acquired at a dose level of D1+D2. Conclusions: The noise characteristics of the MBIR method are significantly different from those of the FBP method. The well known tradeoff relationship between CT image noise and radiation dose has been modified by MBIR to establish a more gradual dependence of noise on dose. Additionally, some other CT noise properties that had been well understood based on the linear system theory have also been altered by MBIR. Clinical CT scan protocols that had been optimized based on the classical CT noise properties need to be carefully re-evaluated for systems equipped with MBIR in order to maximize the method's potential clinical benefits in dose reduction and/or in CT image quality improvement.

Li, Ke; Tang, Jie [Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, Wisconsin 53705 (United States)] [Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, Wisconsin 53705 (United States); Chen, Guang-Hong, E-mail: gchen7@wisc.edu [Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, Wisconsin 53705 and Department of Radiology, University of Wisconsin-Madison, 600 Highland Avenue, Madison, Wisconsin 53792 (United States)] [Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, Wisconsin 53705 and Department of Radiology, University of Wisconsin-Madison, 600 Highland Avenue, Madison, Wisconsin 53792 (United States)

2014-04-15

186

Performance Analysis of Fixed-Margin Iterative Water-Filling for ADSL2+ and VDSL Mixed System  

NASA Astrophysics Data System (ADS)

Crosstalk is a major issue in modern ADSL and VDSL systems. Static spectrum management (SSM), the traditional way to guarantee spectrum compatibility, employs spectral masks which can be overly restrictive and result in poor performance. In this paper, fixed margin iterative water-filling algorithm is investigated in downstream VDSL and ADSL2+ scenario when they are in the same binder. The algorithm can minimize the transmission power and at the same time the overall high-quality service is guaranteed for all the users of the same binder. Simulation results show that ADSL2+ can realize performance gains of up to 80% compared with SSM techniques or ADSL.

Xu, Jian; Song, Sang Seob; Seo, Jongsoo

187

A Calculus for Modelling, Simulating and Analysing Compartmentalized Biological Systems  

NASA Astrophysics Data System (ADS)

This paper introduces Process Calculus, a special modeling language designed for encoding and calculating the behaviors of compartmentalized biological systems. The formalism combines, in a unified framework, two successful computational paradigms—process algebras and membrane systems. The goal of Protein Calculus is to provide a formal tool for transforming collected information from in vivo experiments into coded definition of the different types of proteins, complexes of proteins, and membrane-organized systems of such entities. Using this encoded information as input, our calculus computes, in silico, the possible behaviors of a living system.

Mardare, Radu; Ihekwaba, Adaoha

2007-12-01

188

Analyses of power system vulnerability and total transfer capability  

E-print Network

the integrated reliability performance with consideration of protection system failures. According to these indices, we can locate the weakest point or link in a power system. The whole analysis procedure is based on a non-sequential Monte Carlo simulation method...

Yu, Xingbin

2006-04-12

189

Proposal of actively heated, long stem based Cs delivery system for diagnostic neutral beam source in ITER  

NASA Astrophysics Data System (ADS)

Positioning of Cesium (Cs) oven modules in the complex interface dominated space envelope of a negative ion source such as Diagnostic Neutral Beam (DNB) source for ITER is a challenge not only for the designer of the ion source, but also that of remote handling. A more user friendly design of the Cs delivery could emerge from the consideration of a possibility of injecting the Cs from an oven located outside the vacuum envelope of the ion source, thereby ensuring an ease of Cs refilling and oven maintenance. The design of such a delivery system involves long transmission path of lengths ˜4 m, from ambient to vacuum. System design involves incorporation of a low loss transmission tube enveloped by highly reflective inner surface pipe to reduce the heat losses and therefore heating of the nearby systems. A combination of all metallic valves operated at high temperatures has been incorporated in such a way that the Cs refilling or oven maintenance can be done without breaking the ion source vacuum. Removable joints in the oven heating elements are provided at specific locations to remove the Cs oven for ion source maintenance. Experimental data on Cs transmission over such a long length, required for an effective design of a co-axial transmission, is not presently available. However, an experiment has been carried out in ITER-India making measurements of Cs distribution in coaxial transmission of a length of more than 5 m. These experiments incorporate an additional feature of multiple nozzle distributor based Cs delivery into the ion source which might help in reducing the need of multiple Cs ovens in large ion sources like ITER. The Cs flux from the oven is measured by surface ionization detector (SID). The angular distribution of the Cs flux is measured by a movable SID in linear direction and has been found in good agreement with the calculations. The Cs inventory in the oven reservoir was measured by electrical resistivity measurements methods. The paper proposes to present the measurement results and also proposes a possible configuration of the Cs oven for ITER DNB ion source.

Bansal, G.; Mishra, S.; Pandya, K.; Bandyopadhyay, M.; Soni, J.; Gahlaut, A.; Parmar, K. G.; Shah, S.; Phukan, A.; Roopesh, G.; Ahmed, I.; Chakraborty, A. K.; Singh, M. J.; Schunke, B.; Hemsworth, R.; Svensson, L.; Chareyre, J.; Graceffa, J.

2013-02-01

190

Analyses Of Transient Events In Complex Valve and Feed Systems  

NASA Technical Reports Server (NTRS)

Valve systems in rocket propulsion systems and testing facilities are constantly subject to dynamic events resulting from the timing of valve motion leading to unsteady fluctuations in pressure and mass flow. Such events can also be accompanied by cavitation, resonance, system vibration leading to catastrophic failure. High-fidelity dynamic computational simulations of valve operation can yield important information of valve response to varying flow conditions. Prediction of transient behavior related to valve motion can serve as guidelines for valve scheduling, which is of crucial importance in engine operation and testing. In this paper, we present simulations of the diverse unsteady phenomena related to valve and feed systems that include valve stall, valve timing studies as well as cavitation instabilities in components utilized in the test loop.

Ahuja, Vineet; Hosangadi, Ashvin; Cavallo, Peter; Daines, Russell

2005-01-01

191

Comparison of Mode Analyses at Different Resolutions Applied to Nucleic Acid Systems  

Microsoft Academic Search

More than two decades of different types of mode analyses has shown that these techniques can be useful in describing large-scale motions in protein systems. A number of mode analyses are available and include quasiharmonics, classical normal mode, block normal mode, and the elastic network model. Each of these methods has been validated for protein systems and this variety allows

Adam W. Van Wynsberghe; Qiang Cui

2005-01-01

192

Analysing Finnish Steering System from the Perspective of Social Space: The Case of the "Campus University"  

ERIC Educational Resources Information Center

The present study analyses Finnish higher education steering system, management by results, from the perspective of higher education institutions. We ask what happens inside a higher education institution, called here the "Campus University", during the actual negotiations related to the national steering system. We analyse not only the management…

Treuthardt, Leena; Valimaa, Jussi

2008-01-01

193

Analysing Student Programs in the PHP Intelligent Tutoring System  

ERIC Educational Resources Information Center

Programming is a subject that many beginning students find difficult. The PHP Intelligent Tutoring System (PHP ITS) has been designed with the aim of making it easier for novices to learn the PHP language in order to develop dynamic web pages. Programming requires practice. This makes it necessary to include practical exercises in any ITS that…

Weragama, Dinesha; Reye, Jim

2014-01-01

194

Deviational analyses for validating regulations on real systems  

E-print Network

of dependability assurance is safety; national and interna- tional procedures require operators of aircraft is a traditional way of exploring the safety of systems. The results of deviational analysis contribute to tradi- tional safety cases and safety arguments. We extend deviational analysis to other aspects

Kelly, Tim

195

Mechanical Analyses for coupled Vegetation-Flow System  

NASA Astrophysics Data System (ADS)

Vegetation in riparian areas plays important roles in hydrology, geomorphology and ecology in local environment. Mechanical response of the aquatic vegetation to hydraulic forces and its impact on flow hydraulics have received considerable attention due to implications for flood control, habitat restoration, and water resources management. This study aims to advance understanding of the mechanical properties of in-stream vegetation including drag force, moment and stress. Dynamic changes of these properties under various flow conditions largely determine vegetation affected flow field and dynamic resistance with progressive bending, and hydraulic conditions for vegetation failure (rupture or wash-out) thus are critical for understanding the coupled vegetation-flow system. A new approach combining fluid and material mechanics is developed in this study to examine the behavior of both rigid and flexible vegetation. The major advantage of this approach is its capability to treat large deflection (bending) of plants and associated changes of mechanical properties in both vegetation and flow. Starting from simple emergent vegetation, both static and dynamic formulations of the problem are presented and the solutions are compared. Results show the dynamic behavior of a simplified system mimicking complex and real systems, implying the approach is able to disclose the physical essence of the coupled system. The approach is extended to complex vegetation under both submerged and emergent conditions using more realistic representation of biomechanical properties for vegetation.

Chen, L.; Acharya, K.; Stone, M.

2010-12-01

196

A System for Integrated Reliability and Safety Analyses  

NASA Technical Reports Server (NTRS)

We present an integrated reliability and aviation safety analysis tool. The reliability models for selected infrastructure components of the air traffic control system are described. The results of this model are used to evaluate the likelihood of seeing outcomes predicted by simulations with failures injected. We discuss the design of the simulation model, and the user interface to the integrated toolset.

Kostiuk, Peter; Shapiro, Gerald; Hanson, Dave; Kolitz, Stephan; Leong, Frank; Rosch, Gene; Coumeri, Marc; Scheidler, Peter, Jr.; Bonesteel, Charles

1999-01-01

197

Conceptual design analyses for Hanford Site deployable remote spectroscopy systems  

SciTech Connect

This document identifies potential remote, NIR spectroscopic waste surface moisture monitoring system design alternatives to be operated inside one of the Hanford Site, high level, nuclear waste storage tanks. Potential tank waste moisture data impacts from the remote NIR signal transfer through high humidity vapor space is evaluated.

Philipp, B.L.; Reich, F.R.

1994-09-01

198

District Heating Systems Performance Analyses. Heat Energy Tariff  

NASA Astrophysics Data System (ADS)

The paper addresses an important element of the European energy sector: the evaluation of district heating (DH) system operations from the standpoint of increasing energy efficiency and increasing the use of renewable energy resources. This has been done by developing a new methodology for the evaluation of the heat tariff. The paper presents an algorithm of this methodology, which includes not only a data base and calculation equation systems, but also an integrated multi-criteria analysis module using MADM/MCDM (Multi-Attribute Decision Making / Multi-Criteria Decision Making) based on TOPSIS (Technique for Order Performance by Similarity to Ideal Solution). The results of the multi-criteria analysis are used to set the tariff benchmarks. The evaluation methodology has been tested for Latvian heat tariffs, and the obtained results show that only half of heating companies reach a benchmark value equal to 0.5 for the efficiency closeness to the ideal solution indicator. This means that the proposed evaluation methodology would not only allow companies to determine how they perform with regard to the proposed benchmark, but also to identify their need to restructure so that they may reach the level of a low-carbon business.

Ziemele, Jelena; Vigants, Girts; Vitolins, Valdis; Blumberga, Dagnija; Veidenbergs, Ivars

2014-12-01

199

Solar Power System Analyses for Electric Propulsion Missions  

NASA Technical Reports Server (NTRS)

Solar electric propulsion (SEP) mission architectures are applicable to a wide range of NASA missions including human Mars exploration and robotic exploration of the outer planets. In this paper, we discuss the conceptual design and detailed performance analysis of an SEP stage electric power system (EPS). EPS performance, mass and area predictions are compared for several PV array technologies. Based on these studies, an EPS design for a 1-MW class, Human Mars Mission SEP stage was developed with a reasonable mass, 9.4 metric tons, and feasible deployed array area, 5800 sq m. An EPS was also designed for the Europa Mapper spacecraft and had a mass of 151 kg and a deployed array area of 106 sq m.

Kerslake, Thomas W.; Gefert, Leon P.

1999-01-01

200

An iterative model-based cogging compensator for the Green Bank Telescope servo system  

NASA Astrophysics Data System (ADS)

This paper outlines an anti-cogging methodology and summarizes the current state of motor cogging cancellation on the Green Bank Telescope (GBT). An iterative, model-based algorithm is developed for finding the anticogging signal which yields rapid convergence. This method fills a gap in present methodologies in that it can serve as a drop-in cogging solution which operates in the presence of unknown structural dynamics as well as with an existing feedback controller. The algorithm is described and demonstrated on a 40 HP DC brushed motor test bed and also on the GBT's elevation axis motors. Results and implementation experience from deploying the algorithm on a motor test bed and on the GBT are discussed.

Franke, Timothy; Weadon, Timothy; Ford, John; Garcia-Sanz, Mario

2014-07-01

201

A non-linear iterative method for multi-layer DOT sub-surface imaging system.  

PubMed

Diffuse Optical Tomography (DOT) has become an emerging non-invasive technology, and has been widely used in clinical diagnosis. Functional near-infrared (FNIR) is one of the important applications of DOT. However, FNIR is used to reconstruct two-dimensional (2D) images for the sake of good spatial and temporal resolution. In this paper we propose a multiple-input and multiple-output (MIMO) based data extraction algorithm method in order to increase the spatial and temporal resolution. The non-linear iterative method is used to reconstruct better resolution images layer by layer. In terms of theory, the simulation results and original images are nearly identical. The proposed reconstruction method performs good spatial resolution, and has a depth resolutions capacity of three layers. PMID:25569931

Hsiang-Wen Hou; Shih-Yang Wu; Hao-Jan Sun; Wai-Chi Fang

2014-08-01

202

System analyses on advanced nuclear fuel cycle and waste management  

NASA Astrophysics Data System (ADS)

To evaluate the impacts of accelerator-driven transmutation of waste (ATW) fuel cycle on a geological repository, two mathematical models are developed: a reactor system analysis model and a high-level waste (HLW) conditioning model. With the former, fission products and residual trans-uranium (TRU) contained in HLW generated from a reference ATW plant operations are quantified and the reduction of TRU inventory included in commercial spent-nuclear fuel (CSNF) is evaluated. With the latter, an optimized waste loading and composition in solidification of HLW are determined and the volume reduction of waste packages associated with CSNF is evaluated. WACOM, a reactor system analysis code developed in this study for burnup calculation, is validated by ORIGEN2.1 and MCNP. WACOM is used to perform multicycle analysis for the reference lead-bismuth eutectic (LBE) cooled transmuter. By applying the results of this analysis to the reference ATW deployment scenario considered in the ATW roadmap, the HLW generated from the ATW fuel cycle is quantified and the reduction of TRU inventory contained in CSNF is evaluated. A linear programming (LP) model has been developed for determination of an optimized waste loading and composition in solidification of HLW. The model has been applied to a US-defense HLW. The optimum waste loading evaluated by the LP model was compared with that estimated by the Defense Waste Processing Facility (DWPF) in the US and a good agreement was observed. The LP model was then applied to the volume reduction of waste packages associated with CSNF. Based on the obtained reduction factors, the expansion of Yucca Mountain Repository (YMR) capacity is evaluated. It is found that with the reference ATW system, the TRU contained in CSNF could be reduced by a factor of ˜170 in terms of inventory and by a factor of ˜40 in terms of toxicity under the assumed scenario. The number of waste packages related to CSNF could be reduced by a factor of ˜8 in terms of volume and by factor of ˜10 on the basis of electricity generation when a sufficient cooling time for discharged spent fuel and zero process chemicals in HLW are assumed. The expansion factor of Yucca Mountain Repository capacity is estimated to be a factor of 2.4, much smaller than the reduction factor of CSNF waste packages, due to the existence of DOE-owned spent fuel and HLW. The YMR, however, could support 10 times greater electricity generation as long as the statutory capacity of DOE-owned SNF and HLW remains unchanged. This study also showed that the reduction of the number of waste packages could strongly be subject to the heat generation rate of HLW and the amount of process chemicals contained in HLW. For a greater reduction of the number of waste packages, a sufficient cooling time for discharged fuel and efforts to minimize the amount of process chemicals contained in HLW are crucial.

Cheon, Myeongguk

203

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

Microsoft Academic Search

During inductive plasma operation of ITER, fusion power will reach 500 MW with an energy multiplication factor of 10. The heat will be transferred by the Tokamak Cooling Water System (TCWS) to the environment using the secondary cooling system. Plasma operations are inherently safe even under the most severe postulated accident condition a large, in-vessel break that results in a

Jan Berry; Juan J Ferrada; Warren Curd; Giovanni Dell Orco; Vladimir Barabash; Seokho H Kim

2011-01-01

204

Sensitive Optical and Microfluidic Systems for Cellular Analyses  

NASA Astrophysics Data System (ADS)

Investigating rare cells and heterogeneous subpopulations is challenging for a myriad reasons. This dissertation describes novel techniques to analyze single molecules, synaptic vesicles, and rare circulating tumor cells. The eDAR platform for isolating rare cells in fluids provides a new method to monitor breast cancer status in patients as well as to guide research for personalized treatment and efficacy. In a side-by-side comparison with CellSearch, eDAR detected CTCs in all 20 Stage IV metastatic breast cancer patients while the CellSearch system found CTCs in just 8 patients. The single-molecule capillary electrophoresis technology is a method to characterize an entire sample one molecule at a time, providing detailed information about the absolute number and nature of molecules present in a sample. The nFASS platform has the potential to apply the advantages that currently exist in flow cytometry to the study of items on a much smaller scale such as subcellular organelles and nanometer-sized objects. For example, the isolation of subpopulations of synaptic vesicles will allow for detailed protein quantification and identification in the study of neurological diseases. These tools facilitate fundamental investigation of objects ranging from single molecules to single cells.

Schiro, Perry G.

205

Web-Based Assessment and Test Analyses (WATA) System: Development and Evaluation  

ERIC Educational Resources Information Center

This study introduces the development of a Web-based assessment system, the Web-based Assessment and Test Analyses (WATA) system, and examines its impacts on teacher education. The WATA system is a follow-on system, which applies the Triple-A Model (assembling, administering, and appraising). Its functions include (1) an engine for teachers to…

Wang, T. H.; Wang, K. H.; Wang, W. L.; Huang, S. C.; Chen, S. Y.

2004-01-01

206

An iterative Riemann solver for systems of hyperbolic conservation law s, with application to hyperelastic solid mechanics  

SciTech Connect

In this paper we present a general iterative method for the solution of the Riemann problem for hyperbolic systems of PDEs. The method is based on the multiple shooting method for free boundary value problems. We demonstrate the method by solving one-dimensional Riemann problems for hyperelastic solid mechanics. Even for conditions representative of routine laboratory conditions and military ballistics, dramatic differences are seen between the exact and approximate Riemann solution. The greatest discrepancy arises from misallocation of energy between compressional and thermal modes by the approximate solver, resulting in nonphysical entropy and temperature estimates. Several pathological conditions arise in common practice, and modifications to the method to handle these are discussed. These include points where genuine nonlinearity is lost, degeneracies, and eigenvector deficiencies that occur upon melting.

Miller, Gregory H.

2003-08-06

207

Intelligent Control of a Sensor-Actuator System via Kernelized Least-Squares Policy Iteration  

PubMed Central

In this paper a new framework, called Compressive Kernelized Reinforcement Learning (CKRL), for computing near-optimal policies in sequential decision making with uncertainty is proposed via incorporating the non-adaptive data-independent Random Projections and nonparametric Kernelized Least-squares Policy Iteration (KLSPI). Random Projections are a fast, non-adaptive dimensionality reduction framework in which high-dimensionality data is projected onto a random lower-dimension subspace via spherically random rotation and coordination sampling. KLSPI introduce kernel trick into the LSPI framework for Reinforcement Learning, often achieving faster convergence and providing automatic feature selection via various kernel sparsification approaches. In this approach, policies are computed in a low-dimensional subspace generated by projecting the high-dimensional features onto a set of random basis. We first show how Random Projections constitute an efficient sparsification technique and how our method often converges faster than regular LSPI, while at lower computational costs. Theoretical foundation underlying this approach is a fast approximation of Singular Value Decomposition (SVD). Finally, simulation results are exhibited on benchmark MDP domains, which confirm gains both in computation time and in performance in large feature spaces. PMID:22736969

Liu, Bo; Chen, Sanfeng; Li, Shuai; Liang, Yongsheng

2012-01-01

208

Analysing Engineering Tasks Using a Hybrid Machine Vision and Knowledge Based System Application  

E-print Network

tasks, which is learned by our system from input sequences annotated by profes- sional civil engineersAnalysing Engineering Tasks Using a Hybrid Machine Vision and Knowledge Based System Application Ioannis Kaloskampis 1,2 , Yulia A. Hicks 1 , and David Marshall2 1 School of Engineering, Cardiff

Martin, Ralph R.

209

Development of Localized Plasma Etching System for Failure Analyses in Semiconductor Devices  

Microsoft Academic Search

We have successufully developed a localized plasma etching system for failure analyses in semiconductor devices. The plasma was excited by a capacitively coupled plasma technique using a quartz capillary tube and the system can be operated by both methods of drawing etching gases into the glass tube (inward plasma method) and blowing etching gases out of the tube (outward plasma

Shun'ichiro Shimbori; Yuya Shirayama; Tatsuo Kawakami; Shuntaro Yokosuka; Kenta Kashimura; Tohru Wataya; Tetsuo Shimizu; Yasuhisa Naitoh; Hiroshi Tokumoto

2010-01-01

210

Development of active control systems on ASDEX upgrade in view of ITER discharge scenarios  

Microsoft Academic Search

ASDEX Upgrade has a large variety of technical systems, heating and fuelling as well as digital control systems needed for control and optimisation of high performance plasmas. The neutral beam injection (NBI), electron cyclotron RF (ECRF) and ion cyclotron resonance frequency (ICRF) heating systems are able to operate in heating as well as in current drive (CD) mode. One of

V. Mertens; J. Hobirk; A. Kallenbach; P. Lang; A. Mück; G. Pautasso; G. Raupp; A. Sips; J. Stober; H. Zohm

2003-01-01

211

Thermal-Hydraulic System Study of the Helium Cooled Pebble Bed (HCPB) Test Blanket Module (TBM) for ITER Using System Code RELAP5  

NASA Astrophysics Data System (ADS)

The HCPB concept has been a European DEMO reference concept for nearly one decade. Detailed thermal-hydraulic study on the control behavior of the whole system is one of the important parts of this development. The thermal-hydraulic effect of the TBM-combined cooling circuit during a cyclic operation in ITER has been studied using the system code RELAP5. The RELAP5 is based on an one-dimensional, transient two-fluid model for the flow of a two-phase steam-water mixture that can contain noncondensable components like Helium. The RELAP5-models are modified to take the cyclic operation of the circulator, heat exchanger, bypass, valves etc in to account. A sequence of operational phases is investigated, starting from the cold state through the heating phase that brings the system to a stand-by condition, followed by typical power cycles applied in ITER. The results show that the implemented control mechanisms keep the inlet temperature to the TBM and the total mass flow rate at the required values through all phases.

Jin, Xuezhou; R, Meyder

2005-04-01

212

Rocket engine system reliability analyses using probabilistic and fuzzy logic techniques  

NASA Technical Reports Server (NTRS)

The reliability of rocket engine systems was analyzed by using probabilistic and fuzzy logic techniques. Fault trees were developed for integrated modular engine (IME) and discrete engine systems, and then were used with the two techniques to quantify reliability. The IRRAS (Integrated Reliability and Risk Analysis System) computer code, developed for the U.S. Nuclear Regulatory Commission, was used for the probabilistic analyses, and FUZZYFTA (Fuzzy Fault Tree Analysis), a code developed at NASA Lewis Research Center, was used for the fuzzy logic analyses. Although both techniques provided estimates of the reliability of the IME and discrete systems, probabilistic techniques emphasized uncertainty resulting from randomness in the system whereas fuzzy logic techniques emphasized uncertainty resulting from vagueness in the system. Because uncertainty can have both random and vague components, both techniques were found to be useful tools in the analysis of rocket engine system reliability.

Hardy, Terry L.; Rapp, Douglas C.

1994-01-01

213

Identification of multivariable nonlinear systems in the presence of colored noises using iterative hierarchical least squares algorithm.  

PubMed

This paper presents an efficient method for identification of nonlinear Multi-Input Multi-Output (MIMO) systems in the presence of colored noises. The method studies the multivariable nonlinear Hammerstein and Wiener models, in which, the nonlinear memory-less block is approximated based on arbitrary vector-based basis functions. The linear time-invariant (LTI) block is modeled by an autoregressive moving average with exogenous (ARMAX) model which can effectively describe the moving average noises as well as the autoregressive and the exogenous dynamics. According to the multivariable nature of the system, a pseudo-linear-in-the-parameter model is obtained which includes two different kinds of unknown parameters, a vector and a matrix. Therefore, the standard least squares algorithm cannot be applied directly. To overcome this problem, a Hierarchical Least Squares Iterative (HLSI) algorithm is used to simultaneously estimate the vector and the matrix of unknown parameters as well as the noises. The efficiency of the proposed identification approaches are investigated through three nonlinear MIMO case studies. PMID:24709386

Jafari, Masoumeh; Salimifard, Maryam; Dehghani, Maryam

2014-07-01

214

On the analyses of mixture vapor pressure data: the hydrogen peroxide/water system and its excess thermodynamic functions.  

PubMed

Reported here are some aspects of the analysis of mixture vapor pressure data using the model-free Redlich-Kister approach that have heretofore not been recognized. These are that the pure vapor pressure of one or more components and the average temperature of the complex apparatuses used in such studies can be obtained from the mixture vapor pressures. The findings reported here raise questions regarding current and past approaches for analyses of mixture vapor pressure data. As a test case for this analysis approach the H2O2-H2O mixture vapor pressure measurements reported by Scatchard, Kavanagh, and Tickner (G. Scatchard, G. M. Kavanagh, L. B. Ticknor, J. Am. Chem. Soc. 1952, 74, 3715-3720; G. M. Kavanagh, PhD. Thesis, Massachusetts Institute of Technology (USA), 1949) have been used; there is significant recent interest in this system. It was found that the original data is fit far better with a four-parameter Redlich-Kister excess energy expansion with inclusion of the pure hydrogen peroxide vapor pressure and the temperature as parameters. Comparisons of the present results with the previous analyses of this suite of data exhibit significant deviations. A precedent for consideration of iteration of temperature exists from the little-known work of Uchida, Ogawa, and Yamaguchi (S. Uchida, S. Ogawa, M. Yamaguchi, Japan Sci. Eng. Sci. 1950, 1, 41-49) who observed significant variations of temperature from place to place within a carefully insulated apparatus of the type traditionally used in mixture vapor pressure measurements. For hydrogen peroxide, new critical constants and vapor pressure-temperature equations needed in the analysis approach described above have been derived. Also temperature functions for the four Redlich-Kister parameters were derived, that allowed calculations of the excess Gibbs energy, excess entropy, and excess enthalpy whose values at various temperatures indicate the complexity of H2O2-H2O mixtures not evident in the original analyses of this suite of experimental results. PMID:15551324

Manatt, Stanley L; Manatt, Margaret R R

2004-12-01

215

Statistical analyses to support forensic interpretation for a new ten-locus STR profiling system.  

PubMed

A new ten-locus STR (short tandem repeat) profiling system was recently introduced into casework by the Forensic Science Service (FSS) and statistical analyses are described here based on data collected using this new system for the three major racial groups of the UK: Caucasian. Afro-Caribbean and Asian (of Indo-Pakistani descent). Allele distributions are compared and the FSS position with regard to routine significance testing of DNA frequency databases is discussed. An investigation of match probability calculations is carried out and the consequent analyses are shown to provide support for proposed changes in how the FSS reports DNA results when very small match probabilities are involved. PMID:11296886

Foreman, L A; Evett, I W

2001-01-01

216

Disturbance rejection performance analyses of closed loop control systems by reference to disturbance ratio.  

PubMed

This study investigates disturbance rejection capacity of closed loop control systems by means of reference to disturbance ratio (RDR). The RDR analysis calculates the ratio of reference signal energy to disturbance signal energy at the system output and provides a quantitative evaluation of disturbance rejection performance of control systems on the bases of communication channel limitations. Essentially, RDR provides a straightforward analytical method for the comparison and improvement of implicit disturbance rejection capacity of closed loop control systems. Theoretical analyses demonstrate us that RDR of the negative feedback closed loop control systems are determined by energy spectral density of controller transfer function. In this manner, authors derived design criteria for specifications of disturbance rejection performances of PID and fractional order PID (FOPID) controller structures. RDR spectra are calculated for investigation of frequency dependence of disturbance rejection capacity and spectral RDR analyses are carried out for PID and FOPID controllers. For the validation of theoretical results, simulation examples are presented. PMID:25311160

Alagoz, Baris Baykant; Deniz, Furkan Nur; Keles, Cemal; Tan, Nusret

2014-10-10

217

DEVELOPMENT AND DEMONSTRATION OF A SUPERCRITICAL HELIUM-COOLED CRYOGENIC VISCOUS COMPRESSOR PROTOTYPE FOR THE ITER VACUUM SYSTEM  

SciTech Connect

As part of the vacuum system for the ITER fusion project, a cryogenic viscouscompressor (CVC) is being developed to collect hydrogenic exhaust gases from the toruscryopumps and compress them to a high enough pressure by regeneration for pumping tothe tritium reprocessing facility. Helium impurities that are a byproduct of the fusionreactions pass through the CVC and are pumped by conventional vacuum pumps andexhausted to the atmosphere. Before the development of a full-scale CVC, a representative,small-scale test prototype was designed, fabricated, and tested. With cooling provided bycold helium gas, hydrogen gas was introduced into the central column of the test prototypepump at flow rates between 0.001 g/s and 0.008 g/s. Based on the temperatures and flowrates of the cold helium gas, different percentages of hydrogen gas were frozen to the column surface wall as the hydrogen gas flow rate increased. Results from the measured temperatures and pressures will form a benchmark that will be used to judge future heattransfer enhancements to the prototype CVC and to develop a computational fluid dynamicmodel that will help develop design parameters for the full-scale CVC.

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

2012-01-01

218

The Impact of British Airways Wind Observations on the Goddard Earth Observing System Analyses and Forecasts  

NASA Technical Reports Server (NTRS)

British Airways flight data recorders can provide valuable meteorological information, but they are not available in real-time on the Global Telecommunication System. Information from the flight recorders was used in the Global Aircraft Data Set (GADS) experiment as independent observations to estimate errors in wind analyses produced by major operational centers. The GADS impact on the Goddard Earth Observing System Data Assimilation System (GEOS DAS) analyses was investigated using GEOS-1 DAS version. Recently, a new Data Assimilation System (fvDAS) has been developed at the Data Assimilation Office, NASA Goddard. Using fvDAS , the, GADS impact on analyses and forecasts was investigated. It was shown the GADS data intensify wind speed analyses of jet streams for some cases. Five-day forecast anomaly correlations and root mean squares were calculated for 300, 500 hPa and SLP for six different areas: Northern and Southern Hemispheres, North America, Europe, Asia, USA These scores were obtained as averages over 21 forecasts from January 1998. Comparisons with scores for control experiments without GADS showed a positive impact of the GADS data on forecasts beyond 2-3 days for all levels at the most areas.

Rukhovets, Leonid; Sienkiewicz, M.; Tenenbaum, J.; Kondratyeva, Y.; Owens, T.; Oztunali, M.; Atlas, Robert (Technical Monitor)

2001-01-01

219

The Validity of Individual Rorschach Variables: Systematic Reviews and Meta-Analyses of the Comprehensive System  

ERIC Educational Resources Information Center

We systematically evaluated the peer-reviewed Rorschach validity literature for the 65 main variables in the popular Comprehensive System (CS). Across 53 meta-analyses examining variables against externally assessed criteria (e.g., observer ratings, psychiatric diagnosis), the mean validity was r = 0.27 (k = 770) as compared to r = 0.08 (k = 386)…

Mihura, Joni L.; Meyer, Gregory J.; Dumitrascu, Nicolae; Bombel, George

2013-01-01

220

Iterative receivers for OFDM systems with dispersive fading and frequency offset  

E-print Network

Serial to (S/P) j,nx yj,n j,nx yj,n Channel H k Receiver Transmitter AWGN noise X Y e e j,k j,k pi fc t x y t t j (2pi( fc -f epsilon ) t+ theta) ? ? Fig. 1. Block diagram of OFDM system. 4 In an OFDM system, the available bandwidth is partitioned into N... where m Ts. The model in (3.1) can be simpli ed 9 to gr(t) = gs(t) X k kej k + N(t) , hgs(t) + N(t) (3.2) Where h , x + jy , aej , Pk kej k is a zero-mean, complex Gaussian random variable with fx;y(x;y) = 12 2 exp x 2 + y2 2 2 ; fa(a) = a 2...

Liu, Hui

2004-09-30

221

Performance Assessment Modeling and Sensitivity Analyses of Generic Disposal System Concepts.  

SciTech Connect

directly, rather than through simplified abstractions. It also a llows for complex representations of the source term, e.g., the explicit representation of many individual waste packages (i.e., meter - scale detail of an entire waste emplacement drift). This report fulfills the Generic Disposal System Analysis Work Packa ge Level 3 Milestone - Performance Assessment Modeling and Sensitivity Analyses of Generic Disposal System Concepts (M 3 FT - 1 4 SN08080 3 2 ).

Sevougian, S. David; Freeze, Geoffrey A. [Sandia National Laboratories, Albuquerque, NM; Gardner, William Payton [Sandia National Laboratories, Albuquerque, NM; Hammond, Glenn Edward [Sandia National Laboratories, Albuquerque, NM; Mariner, Paul [Sandia National Laboratories, Albuquerque, NM

2014-09-01

222

DICE, an efficient system for iterative genomic editing in human pluripotent stem cells.  

PubMed

To reveal the full potential of human pluripotent stem cells, new methods for rapid, site-specific genomic engineering are needed. Here, we describe a system for precise genetic modification of human embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs). We identified a novel human locus, H11, located in a safe, intergenic, transcriptionally active region of chromosome 22, as the recipient site, to provide robust, ubiquitous expression of inserted genes. Recipient cell lines were established by site-specific placement of a 'landing pad' cassette carrying attP sites for phiC31 and Bxb1 integrases at the H11 locus by spontaneous or TALEN-assisted homologous recombination. Dual integrase cassette exchange (DICE) mediated by phiC31 and Bxb1 integrases was used to insert genes of interest flanked by phiC31 and Bxb1 attB sites at the H11 locus, replacing the landing pad. This system provided complete control over content, direction and copy number of inserted genes, with a specificity of 100%. A series of genes, including mCherry and various combinations of the neural transcription factors LMX1a, FOXA2 and OTX2, were inserted in recipient cell lines derived from H9 ESC, as well as iPSC lines derived from a Parkinson's disease patient and a normal sibling control. The DICE system offers rapid, efficient and precise gene insertion in ESC and iPSC and is particularly well suited for repeated modifications of the same locus. PMID:24304893

Zhu, Fangfang; Gamboa, Matthew; Farruggio, Alfonso P; Hippenmeyer, Simon; Tasic, Bosiljka; Schüle, Birgitt; Chen-Tsai, Yanru; Calos, Michele P

2014-03-01

223

A rad-hard, steady state, digital imaging bolometer system for ITER  

SciTech Connect

The concept and design of a new type of bolometer system which can function with excellent spatial resolution and good time resolution in the next generation of long-pulse (or steady-state), harsh-neutron environment fusion plasmas, is outlined. It uses a cooled pinhole camera design, employing a robust, passive, segmented radiation absorber, cooled from the back-side. Infrared emission from the absorber`s front surface is relayed by metal mirror optics to a shielded, high-resolution IR video camera with {+-} 0.01 C temperature resolution. It can make thousands of simultaneous ``pixel`` measurements at up to 50--60 Hz, without any signal wires through the vacuum interface.

Wurden, G.A.

1995-09-01

224

An Iterative Model for Micro-Electro-Mechanical-Systems (MEMS) Deformable Mirrors  

NASA Astrophysics Data System (ADS)

We present a high accuracy Micro-Electro-Mechanical-System (MEMS) deformable mirror (DM) control algorithm which was implemented in the real-time control interface of the Subaru Coronagraphic Extreme Adaptive Optics project (SCExAO) for the on-sky engineering run of July 2011. MEMS DMs are an attractive DM technology for ExAO because they offer unprecedented actuator density and actuator counts. The small size and low cost per actuator also make them attractive for Multi-Object AO (MOAO), where one DM is needed per science field. These applications both require a DM model capable of reproducing a phase map with a precision of few nm rms. The high accuracy DM control algorithm presented below is suitable for open-loop AO systems where DM calibration is essential. For SCExAO, the high accuracy wavefront sensing uses DM modulations to coherently mix light with slow/static speckles and precisely measure their complex amplitude. Therefore, wavefront sensing and correction both depend on precise DM control. The model (described in Blain et al., 2011) which relies (i) on a physical model of the actuators and the membrane and (ii) on the optimization of 8 coefficients, could be adopted as an open-loop control solution for future MOAO or ExAO ELTs instruments. During the initial test phase at the UVic AO Lab, the performance of the model reached an open-loop error equal to 7.3% of the rms of the desired phase (1.6% of the peak-to-valley(PV) of the desired phase) with Kolmogorov type wavefront (test performed over 10 phase screens with a mean PV of 1448.3 nm and a mean rms of 489.5 nm).

Blain, Célia; Guyon, Olivier; Bradley, Colin; Martinache, Frantz; Clergeon, Christophe

2011-09-01

225

Fully automated, four-column capillary LC-MS system for maximizing throughput in proteomic analyses  

PubMed Central

We describe a 4-column, high-pressure capillary liquid chromatography (LC) system for robust, high-throughput LC-MS(/MS) analyses. This system performs multiple LC separations in parallel, but staggers each of them such that the data-rich region of each separation is sampled sequentially. By allowing nearly continuous data acquisition, this design maximizes the use of the mass spectrometer. Each analytical column is connected to a corresponding ESI emitter in order to avoid the use of post-column switching and associated dead volume issues. Encoding translation stages are employed to sequentially position the emitters at the MS inlet. The high reproducibility of this system is demonstrated using consecutive analyses of global tryptic digest of the microbe Shewanella oneidensis. PMID:18044960

Livesay, Eric A.; Tang, Keqi; Taylor, Beverley K.; Buschbach, Michael A.; Hopkins, Derek F.; LaMarche, Brian L.; Zhao, Rui; Shen, Yufeng; Orton, Daniel J.; Moore, Ronald J.; Kelly, Ryan T.; Udseth, Harold R.; Smith, Richard D.

2008-01-01

226

Development and irradiation test of lost alpha detection system for ITER.  

PubMed

We developed a lost alpha detection system to use in burning plasma experiments. The scintillators of Ag:ZnS and polycrystalline Ce:YAG were designed for a high-temperature environment, and the optical transmission line was designed to transmit from the scintillator to the port plug. The required optical components of lenses and mirrors were irradiated using the fission reactor with the initial result that there was no clear change after the irradiation with a neutron flux of 9.6×10(17)?nm(-2)? s(-1) for 48 h. We propose a diagnostic of alpha particle loss, so-called alpha particle induced gamma ray spectroscopy. The initial laboratory test has been carried out by the use of the Ce doped Lu(2)SiO(5) scintillator detector and an Am-Be source to detect the 4.44 MeV high energy gamma ray due to the (9)Be(?,n?)(12)C reaction. PMID:21033839

Nishiura, M; Nagasaka, T; Fujioka, K; Fujimoto, Y; Tanaka, T; Ido, T; Yamamoto, S; Kashiwa, S; Sasao, M

2010-10-01

227

Space transfer concepts and analyses for exploration missions. Technical directive 12: Beamed power systems study  

NASA Technical Reports Server (NTRS)

Parametric models were constructed for Earth-based laser powered electric orbit transfer from low Earth orbit to geosynchronous orbit. These models were used to carry out performance, cost/benefit, and sensitivity analyses of laser-powered transfer systems including end-to-end life cycle cost analyses for complete systems. Comparisons with conventional orbit transfer systems were made indicating large potential cost savings for laser-powered transfer. Approximate optimization was done to determine best parameter values for the systems. Orbit transfer flights simulations were conducted to explore effects of parameters not practical to model with a spreadsheet. The simulations considered view factors that determine when power can be transferred from ground stations to an orbit transfer vehicle and conducted sensitivity analyses for numbers of ground stations, Isp including dual-Isp transfers, and plane change profiles. Optimal steering laws were used for simultaneous altitude and plane change. Viewing geometry and low-thrust orbit raising were simultaneously simulated. A very preliminary investigation of relay mirrors was made.

Eder, D.

1992-01-01

228

Portable, fully autonomous, ion chromatography system for on-site analyses.  

PubMed

The basic operating principles of a portable, fully autonomous, ion chromatography system are described. The system affords the user the ability to collect and analyze samples continuously for 27 days, or about 1930 injections before needing any user intervention. Within the 13 kg system, is a fully computer controlled autosampling, chromatography and data acquisition system. An eluent reflux device (ERD), which integrates eluent suppression and generation in a single multi-chambered device, is used to minimize eluent consumption. During operation, about 1 ?L of water per minute is lost to waste while operating standard-bore chromatography at 0.5 mL min(-1) due to eluent refluxing. Over the course of 27 days, about 100mL of rinse water is consumed, effectively eliminating waste production. Data showing the reproducibility (below 1% relative standard deviation over 14 days) of the device is also presented. Chromatographic analyses of common anions (Cl(-), NO3(-), SO4(2-), PO4(3-)), is accomplished in under 15 min using a low backpressure guard column with ? 25 mM KOH isocratic elution. For detection, a small capacitively-coupled contactless conductivity detector (C4D) is employed, able to report analytes in the sub to low micromolar range. Preconcentration of the injected samples gives a 50-fold decrease in detection limits, primarily utilized for in-situ detection of phosphate (LOQ 10 ?g L(-1)). Field analyses are shown for multiple on-site analyses of stream water indifferent weather conditions. PMID:24913366

Elkin, Kyle R

2014-07-25

229

Iterative Magnetometer Calibration  

NASA Technical Reports Server (NTRS)

This paper presents an iterative method for three-axis magnetometer (TAM) calibration that makes use of three existing utilities recently incorporated into the attitude ground support system used at NASA's Goddard Space Flight Center. The method combines attitude-independent and attitude-dependent calibration algorithms with a new spinning spacecraft Kalman filter to solve for biases, scale factors, nonorthogonal corrections to the alignment, and the orthogonal sensor alignment. The method is particularly well-suited to spin-stabilized spacecraft, but may also be useful for three-axis stabilized missions given sufficient data to provide observability.

Sedlak, Joseph

2006-01-01

230

Analyses of Markov decision process structure regarding the possible strategic use of interacting memory systems.  

PubMed

Behavioral tasks are often used to study the different memory systems present in humans and animals. Such tasks are usually designed to isolate and measure some aspect of a single memory system. However, it is not necessarily clear that any given task actually does isolate a system or that the strategy used by a subject in the experiment is the one desired by the experimenter. We have previously shown that when tasks are written mathematically as a form of partially observable Markov decision processes, the structure of the tasks provide information regarding the possible utility of certain memory systems. These previous analyses dealt with the disambiguation problem: given a specific ambiguous observation of the environment, is there information provided by a given memory strategy that can disambiguate that observation to allow a correct decision? Here we extend this approach to cases where multiple memory systems can be strategically combined in different ways. Specifically, we analyze the disambiguation arising from three ways by which episodic-like memory retrieval might be cued (by another episodic-like memory, by a semantic association, or by working memory for some earlier observation). We also consider the disambiguation arising from holding earlier working memories, episodic-like memories or semantic associations in working memory. From these analyses we can begin to develop a quantitative hierarchy among memory systems in which stimulus-response memories and semantic associations provide no disambiguation while the episodic memory system provides the most flexible disambiguation, with working memory at an intermediate level. PMID:19129935

Zilli, Eric A; Hasselmo, Michael E

2008-01-01

231

Design of transducer structure parameters and materials characteristics analyses for electrical capacitance tomography system  

NASA Astrophysics Data System (ADS)

The object of this paper majors in the research of 8-electrode oil-water two-phase flow electrical capacitance tomography system. The distribution models of transducer's field are established by the finite element method for the influence of the parameters of transducer's structure on the performance of transducer. The analyses of simulation and experiment and the transducer's design optimized are done, and the measure function of transducer's design optimized is proposed based on transducer parameters. The system of 8-electrode oil-water two-phase flow electrical capacitance tomography is designed based on the results of theory and simulation analyses. The sensitivity and uniformity of sensitive field is improved and the design of the measurement circuit is easier but the data precision of sensitive field is enough for image reconstruction.

Qin, Mei

2010-01-01

232

The conceptual design of an electron cyclotron emission imaging system for studying ITER-like high temperature plasmas  

NASA Astrophysics Data System (ADS)

The design of an electron cyclotron emission imaging (ECEI) system for two-dimensional (2D) observation of the magnetohydrodynamical modes in high temperature ITER (from ‘International Thermonuclear Experimental Reactor’) H-mode-like plasmas (5.3 T and 25 keV) based on fundamental ordinary mode (O1-mode) and second-harmonic extraordinary mode (X2-mode) measurements is explored conceptually. For studying the spatial resolution in high temperature plasmas, the relativistic broadening and inward shift of the emission layer in the mid-plane are calculated. The radial spatial resolution is significantly degraded in the range R < 5.1 m for the O1-mode and in the range R < 6.9 m for the X2-mode. The region with R < 6.5 m is inaccessible for X2-mode study. The emission layer width is enlarged in a narrow region of the pedestal due to the magnetic field being modified by the large pressure gradient. The broadening and shift in the poloidal plane are also calculated, to investigate their effects on 2D measurements. The frequency range of electron cyclotron emission measurements is selected to protect the system from stray radiations of the 170 GHz electron cyclotron resonance heating source and to avoid harmonic overlap. The frequency ranges of 115–160 GHz for the O1-mode and 230–320 GHz for the X2-mode provide radial coverage of 5.9 < R < 8.2 m or ?0.15 < r/a < 1.The ECEI system utilizes a dual-array detection technique which provides a simultaneous measurement at two radial positions, and each array has 8 by 16 (radial by vertical) channels. The radial image size with 8 channels is ?41–76 cm for the O1-mode and ?19–36 cm for the X2-mode, with sufficient resolution. The front-end optics, which focuses the electron cyclotron emission to the low loss corrugated transmission waveguides, is designed with two flat mirrors and two focusing mini-lens arrays. The vertical image size with 16 channels is ?150 cm and the spot size of each channel is 8–15 cm in the plasma region, taking into account the sensitivity pattern of the waveguide. The refraction effect due to inhomogeneous plasma enlarges the vertical image size up to 20% and 5% for the O1-mode and X2-mode cases, respectively. The horizontal distortion due to the relativistic inwards shift is reduced by the increased toroidal field in the core region.

Lee, W.; Yun, G. S.; Park, H. K.; Nam, Y. B.; Seon, C. R.

2014-09-01

233

Iteration with Spreadsheets.  

ERIC Educational Resources Information Center

Presents several examples of the iteration method using computer spreadsheets. Examples included are simple iterative sequences and the solution of equations using the Newton-Raphson formula, linear interpolation, and interval bisection. (YP)

Smith, Michael

1990-01-01

234

Analyses and tests of the B-1 aircraft structural mode control system  

NASA Technical Reports Server (NTRS)

Analyses and flight tests of the B-1 structural mode control system (SMCS) are presented. Improvements in the total dynamic response of a flexible aircraft and the benefits to ride qualities, handling qualities, crew efficiency, and reduced dynamic loads on the primary structures, were investigated. The effectiveness and the performance of the SMCS, which uses small aerodynamic surfaces at the vehicle nose to provide damping to the structural modes, were evaluated.

Wykes, J. H.; Byar, T. R.; Macmiller, C. J.; Greek, D. C.

1980-01-01

235

The Characteristic Analyses of Images from the UAV Remote Sensing System  

Microsoft Academic Search

Comparing with the satellite and the common aerial vehicle, the UAVRSS (unmanned aerial vehicle remote sensing system) is a new type of aviation remote sensing for earth observation. It can work in an ultrahigh (10~30km) or ultra-low space (150~400m) for its long time, instantaneous transmission, low-cost, loading ability, etc. In this paper, through the characteristic analyses of the UAVRSS and

Zhao Hongying; Yan Lei; Gou Zhiyang; Zhang Lifu

2006-01-01

236

Preparee au Laboratoire d'Analyse et d'Architecture des Syst`emes du CNRS  

E-print Network

de Lorraine et Alain Th´eron, Professeur agr´eg´e au Lyc´ee Pierre de Fermat `a Toulouse. Je lesTH`ESE Pr´epar´ee au Laboratoire d'Analyse et d'Architecture des Syst`emes du CNRS En vue de l'obtention du Doctorat de l'Universit´e Paul Sabatier de Toulouse Sp´ecialit´e Automatique Par Christophe FARGES

Paris-Sud XI, Université de

237

Diagnostic Challenges and Opportunities on ITER David Johnson  

E-print Network

challenges ­ diagnostics currently being designed into ITER ports ­ `uncredited' systems · US role in ITER' - supporting structures and shielding 1. 2 upper ports preliminary 2. 2 equatorial ports preliminary 3. 1

238

Extraterrestrial Materials: The Role of Synchrotron Radiation Analyses in the Study of our Solar System  

SciTech Connect

Sample-return missions and natural collection processes have provided us with a surprisingly extensive collection of matter from Solar System bodies other than the Earth. These collections include samples from the Moon, Mars, asteroids, interplanetary dust, and, recently, from the Sun (solar wind) and a comet. This presentation will describe some of these materials, how they were collected, and what we have learned from them. Synchrotron radiation analyses of these materials are playing an increasingly valuable role in unraveling the histories and properities of the parent Solar System bodies.

Sutton, Stephen R. [University of Chicago

2006-04-05

239

System design analyses of a rotating advanced-technology space station for the year 2025  

NASA Technical Reports Server (NTRS)

Studies of an advanced technology space station configured to implement subsystem technologies projected for availability in the time period 2000 to 2025 is documented. These studies have examined the practical synergies in operational performance available through subsystem technology selection and identified the needs for technology development. Further analyses are performed on power system alternates, momentum management and stabilization, electrothermal propulsion, composite materials and structures, launch vehicle alternates, and lunar and planetary missions. Concluding remarks are made regarding the advanced technology space station concept, its intersubsystem synergies, and its system operational subsystem advanced technology development needs.

Queijo, M. J.; Butterfield, A. J.; Cuddihy, W. F.; Stone, R. W.; Wrobel, J. R.; Garn, P. A.; King, C. B.

1988-01-01

240

Solar power satellite system definition study. Volume 2, phase 1: Systems analyses tradeoffs.  

NASA Technical Reports Server (NTRS)

A systems definition study of the solar power satellite system is presented. The satellite solar energy conversion and microwave power transmission systems are discussed. Space construction and support systems are examined including a series construction and equipment characteristics analysis. Space transportation for the satellite and the ground receiving station are assessed.

1979-01-01

241

An evaluation system for electronic retrospective analyses in radiation oncology: implemented exemplarily for pancreatic cancer  

NASA Astrophysics Data System (ADS)

To date, conducting retrospective clinical analyses is rather difficult and time consuming. Especially in radiation oncology, handling voluminous datasets from various information systems and different documentation styles efficiently is crucial for patient care and research. With the example of patients with pancreatic cancer treated with radio-chemotherapy, we performed a therapy evaluation by using analysis tools connected with a documentation system. A total number of 783 patients have been documented into a professional, web-based documentation system. Information about radiation therapy, diagnostic images and dose distributions have been imported. For patients with disease progression after neoadjuvant chemoradiation, we designed and established an analysis workflow. After automatic registration of the radiation plans with the follow-up images, the recurrence volumes are segmented manually. Based on these volumes the DVH (dose-volume histogram) statistic is calculated, followed by the determination of the dose applied to the region of recurrence. All results are stored in the database and included in statistical calculations. The main goal of using an automatic evaluation system is to reduce time and effort conducting clinical analyses, especially with large patient groups. We showed a first approach and use of some existing tools, however manual interaction is still necessary. Further steps need to be taken to enhance automation. Already, it has become apparent that the benefits of digital data management and analysis lie in the central storage of data and reusability of the results. Therefore, we intend to adapt the evaluation system to other types of tumors in radiation oncology.

Kessel, Kerstin A.; Jäger, Andreas; Bohn, Christian; Habermehl, Daniel; Zhang, Lanlan; Engelmann, Uwe; Bougatf, Nina; Bendl, Rolf; Debus, Jürgen; Combs, Stephanie E.

2013-03-01

242

RBMK coupled neutronics/thermal-hydraulics analyses by two independent code systems  

SciTech Connect

This paper presents the coupled neutronics/thermal-hydraulics activities carried out in the framework of the part B of the TACIS project R2.03/97, 'Software development for accident analysis of RBMK reactors in Russia'. Two independent code systems were assembled, one from the Russian side and the other from the Western side, for studying RBMK core transients. The Russian code system relies on the use of code UNK for neutron data libraries generation and the three-dimensional neutron kinetics thermal-hydraulics coupled codes BARS-KORSAR for plant transient analyses. The Western code system is instead based on the lattice physics code HELIOS and on the RELAP5-3D C code. Several activities were performed for testing code system's capabilities: the neutron data libraries were calculated and verified by precise Monte Carlo calculations, the coupled codes' steady state results were compared with plant detectors' data, and calculations of several transients were compared. Finally, both code systems proved to have all the capabilities for addressing reliable safety analyses of RBMK reactors. (authors)

Parisi, C.; D'Auria, F. [Univ. of Pisa, Dept. of Mechanical, Nuclear and Production Engineering, via Diotisalvi, 2, 56100 Pisa (Italy); Malofeev, V. [Kurchatov Inst., Kurchatov Square 1, Moscow 123182 (Russian Federation); Ivanov, B.; Ivanov, K. [Pennsylvania State Univ., RDFMG, 230 Reber Building, Univ. Park, PA 16802 (United States)

2006-07-01

243

Performance Analyses of ECCS and Containment Systems for the 4500 MW ESBWR  

SciTech Connect

GE latest evolution of the Boiling Water Reactor, the ESBWR, is an advanced, 4500 MWth nuclear power plant design, submitted to the NRC for design certification in 2005. This paper presents the key results of performance analyses of ESBWR ECCS and containment systems. The ESBWR is designed to take full advantage of passive features to improve the plant performance and economics. The key features are the use of natural circulation during normal operation and passive safety systems for decay heat removal and inventory control. The use of natural circulation results in relatively taller reactor vessel and more in-vessel coolant inventory. Consequently, the water level always covers the core following an accident, assuring no fuel heatup. The use of passive systems results in simpler safety systems. The peak containment pressure and margin to the design value basically depend on the containment volumes and the water inventories. Additionally, these passive systems impose no significant challenge to the operator. Performance analyses for the 4500 MWth ESBWR were made for a spectrum of LOCA events. These calculations accounted for uncertainties and biases in the computer models and used conservative initial conditions and plant parameters. Results of these performance analyses show that: (1) core remains covered with large margin and there is no core heatup in the ESBWR for any break size, (2) the long-term containment pressure increases gradually with time, in the order of hours, and the peak pressure is below the design value with large margin, and (3) the margins depend on the containment volumes and water inventories. (authors)

Cheung, Y.K.; Shiralkar, B.S.; Marquino, W. [GE Energy, 1989 Little Orchard St., San Jose, CA 95125 (United States)

2006-07-01

244

Real-Time Soils Characterization and Analyses Systems Used at Ohio Closure Sites  

SciTech Connect

The Idaho National Engineering and Environmental Laboratory (INEEL) and the Fernald Environmental Management Project (FEMP) have jointly developed a field-deployed analytical system to rapidly scan, characterize, and analyze surface soil contamination. The basic system consists of a sodium iodide (NaI) spectrometer and global positioning system (GPS) hardware. This hardware can be deployed from any of four different platforms depending on the scope of the survey at hand. These platforms range from a large tractor-based unit (the RTRAK) used to survey large, relatively flat areas to a hand-pushed unit where maneuverability is important, to an excavator mounted system used to scan pits and trenches. The mobile sodium iodide concept was initially developed by the FEMP to provide pre-screening analyses for soils contaminated with uranium, thorium, and radium. The initial study is documented in the RTRAK Applicability Study and provides analyses supporting the field usage of the concept. The RTRAK system produced data that required several days of post-processing and analyses to generate an estimation of field coverage and activity levels. The INEEL has provided integrated engineering, computer hardware and software support to greatly streamline the data acquisition and analysis process to the point where real-time activity and coverage maps are available to the field technicians. On-line analyses have been added to automatically convert GPS data to Ohio State-Plane coordinates, examine and correct collected spectra for energy calibration drifts common to NaI spectrometers, and strip spectra in regions of interest to provide moisture corrected activity levels for total uranium, thorium-232, and radium-226. Additionally, the software provides a number of checks and alarms to alert operators that a hand-examination of spectral data in a particular area may be required. The FEMP has estimated that this technology has produced projected site savings in excess of $34M through FY 2006. Additionally, the INEEL has applied this real-time concept to develop an in-situ platform to detect plutonium-238 in contaminated soils to the 50 pCi/g level. The heart of this system is a large-area proportional counter that collects spectra in the x-ray region. A prototype system was demonstrated at the Mound Environmental Management Project (MEMP) in October of 2002.

Roybal, Lyle Gene; Carpenter, Michael Vance; Giles, John Robert; Hartwell, John Kelvin; Danahy, R.

2003-02-01

245

Manned systems utilization analysis (study 2.1). Volume 3: LOVES computer simulations, results, and analyses  

NASA Technical Reports Server (NTRS)

The LOVES computer program was employed to analyze the geosynchronous portion of the NASA's 1973 automated satellite mission model from 1980 to 1990. The objectives of the analyses were: (1) to demonstrate the capability of the LOVES code to provide the depth and accuracy of data required to support the analyses; and (2) to tradeoff the concept of space servicing automated satellites composed of replaceable modules against the concept of replacing expendable satellites upon failure. The computer code proved to be an invaluable tool in analyzing the logistic requirements of the various test cases required in the tradeoff. It is indicated that the concept of space servicing offers the potential for substantial savings in the cost of operating automated satellite systems.

Stricker, L. T.

1975-01-01

246

The second iteration of the Systems Prioritization Method: A systems prioritization and decision-aiding tool for the Waste Isolation Pilot Plant: Volume 2, Summary of technical input and model implementation  

SciTech Connect

The Systems Prioritization Method (SPM) is a decision-aiding tool developed by Sandia National Laboratories (SNL). SPM provides an analytical basis for supporting programmatic decisions for the Waste Isolation Pilot Plant (WIPP) to meet selected portions of the applicable US EPA long-term performance regulations. The first iteration of SPM (SPM-1), the prototype for SPM< was completed in 1994. It served as a benchmark and a test bed for developing the tools needed for the second iteration of SPM (SPM-2). SPM-2, completed in 1995, is intended for programmatic decision making. This is Volume II of the three-volume final report of the second iteration of the SPM. It describes the technical input and model implementation for SPM-2, and presents the SPM-2 technical baseline and the activities, activity outcomes, outcome probabilities, and the input parameters for SPM-2 analysis.

Prindle, N.H.; Mendenhall, F.T.; Trauth, K.; Boak, D.M. [Sandia National Labs., Albuquerque, NM (United States); Beyeler, W. [Science Applications International Corp., Albuquerque, NM (United States); Hora, S. [Hawaii Univ., Hilo, HI (United States); Rudeen, D. [New Mexico Engineering Research Inst., Albuquerque, NM (United States)

1996-05-01

247

Flight test and analyses of the B-1 structural mode control system at supersonic flight conditions  

NASA Technical Reports Server (NTRS)

A practical structural mode control system (SMCS) that could be turned on at takeoff and be left on for the entire flight was demonstrated. The SMCS appears to be more effective in damping the key fuselage bending modes at supersonic speeds than at the design point of Mach 0.85 (for fixed gains). The SMCS has an adverse effect on high frequency symmetric modes; however, this adverse effect did not make the system unstable and does not appear to affect ride quality performance. The vertical ride quality analyses indicate that the basic configuration without active systems is satisfactory for long term exposure. If clear air turbulence were to be encountered, indications are that the SMCS would be very effective in reducing the adverse accelerations. On the other hand, lateral ride quality analyses indicate that the aircraft with the SMCS on does not quite meet the long term exposure criteria, but would be satisfactory for shot term exposure at altitude. Again, the lateral SMCS was shown to be very effective in reducing peak lateral accelerations.

Wykes, J. H.; Kelpl, M. J.; Brosnan, M. J.

1983-01-01

248

Assessment of Tools and Data for System-Level Dynamic Analyses  

SciTech Connect

The only fuel cycle for which dynamic analyses and assessments are not needed is the null fuel cycle - no nuclear power. For every other concept, dynamic analyses are needed and can influence relative desirability of options. Dynamic analyses show how a fuel cycle might work during transitions from today's partial fuel cycle to something more complete, impact of technology deployments, location of choke points, the key time lags, when benefits can manifest, and how well parts of fuel cycles work together. This report summarizes the readiness of existing Fuel Cycle Technology (FCT) tools and data for conducting dynamic analyses on the range of options. VISION is the primary dynamic analysis tool. Not only does it model mass flows, as do other dynamic system analysis models, but it allows users to explore various potential constraints. The only fuel cycle for which constraints are not important are those in concept advocates PowerPoint presentations; in contrast, comparative analyses of fuel cycles must address what constraints exist and how they could impact performance. The most immediate tool need is extending VISION to the thorium/U233 fuel cycle. Depending on further clarification of waste management strategies in general and for specific fuel cycle candidates, waste management sub-models in VISION may need enhancement, e.g., more on 'co-flows' of non-fuel materials, constraints in waste streams, or automatic classification of waste streams on the basis of user-specified rules. VISION originally had an economic sub-model. The economic calculations were deemed unnecessary in later versions so it was retired. Eventually, the program will need to restore and improve the economics sub-model of VISION to at least the cash flow stage and possibly to incorporating cost constraints and feedbacks. There are multiple sources of data that dynamic analyses can draw on. In this report, 'data' means experimental data, data from more detailed theoretical or empirical calculations on technology performance, and assumptions such as the earliest date a technology can be deployed. The only fuel cycles for which we currently have adequate data are those we are sure we will never build, e.g., a PUREX plant in the U.S. For actual candidates, even for once through LWRs, there remain missing data such as how the fuel cycle would be completed with a geologic repository. The most immediate data needs are probably basic reactor physics data for new concepts and data associated with waste management for anything other than current technology. The readiness of tools and data is fluid and depends on what purposes are envisioned to drive upcoming analyses and further definition of the waste-related characteristics of fuel cycle candidates. Tools and data sets evolve as needs evolve. Thus, much of the document explains that if the FCT program wants a certain type of analysis, then the tools and data needs are as indicated. For example, functions can be treated as either commodities or facilities. Reactors, separation, fuel fabrication, repository are treated as facility types. Other functions such as uranium mining, conversion, enrichment, and waste packaging and non-repository disposal are treated as commodities and therefore not modeled as extensively. In summary, the tools are functional and can answer many fuel cycle questions but some analyses will require that the tools be modified to support those analyses.

Steven J. Piet; Nick R. Soelberg

2011-06-01

249

On the safety of ITER accelerators  

PubMed Central

Three 1?MV/40A accelerators in heating neutral beams (HNB) are on track to be implemented in the International Thermonuclear Experimental Reactor (ITER). ITER may produce 500?MWt of power by 2026 and may serve as a green energy roadmap for the world. They will generate ?1?MV 1?h long-pulse ion beams to be neutralised for plasma heating. Due to frequently occurring vacuum sparking in the accelerators, the snubbers are used to limit the fault arc current to improve ITER safety. However, recent analyses of its reference design have raised concerns. General nonlinear transformer theory is developed for the snubber to unify the former snubbers' different design models with a clear mechanism. Satisfactory agreement between theory and tests indicates that scaling up to a 1?MV voltage may be possible. These results confirm the nonlinear process behind transformer theory and map out a reliable snubber design for a safer ITER. PMID:24008267

Li, Ge

2013-01-01

250

On the safety of ITER accelerators.  

PubMed

Three 1 MV/40A accelerators in heating neutral beams (HNB) are on track to be implemented in the International Thermonuclear Experimental Reactor (ITER). ITER may produce 500 MWt of power by 2026 and may serve as a green energy roadmap for the world. They will generate -1 MV 1 h long-pulse ion beams to be neutralised for plasma heating. Due to frequently occurring vacuum sparking in the accelerators, the snubbers are used to limit the fault arc current to improve ITER safety. However, recent analyses of its reference design have raised concerns. General nonlinear transformer theory is developed for the snubber to unify the former snubbers' different design models with a clear mechanism. Satisfactory agreement between theory and tests indicates that scaling up to a 1 MV voltage may be possible. These results confirm the nonlinear process behind transformer theory and map out a reliable snubber design for a safer ITER. PMID:24008267

Li, Ge

2013-01-01

251

ITER Dynamic Tritium Inventory Modeling Code  

Microsoft Academic Search

A tool for tritium inventory evaluation within each sub-system of the Fuel Cycle of ITER is vital, with respect to both the process of licensing ITER and also for operation. It is very likely that measurements of total tritium inventories may not be possible for all sub-systems, however tritium accounting may be achieved by modeling its hold-up within each sub-system

Ioana-R. Cristescu; L. Doerr; A. Busigin; D Murdoch

2005-01-01

252

Battery-powered portable instrument system for single-cell trapping, impedance measurements, and modeling analyses.  

PubMed

A battery-powered portable instrument system for the single-HeLa-cell trapping and analyses is developed. A method of alternating current electrothermal (ACET) and DEP are employed for the cell trapping and the method of impedance spectroscopy is employed for cell characterizations. The proposed instrument (160 mm × 170 mm × 110 mm, 1269 g) equips with a highly efficient energy-saving design that promises approximately 120 h of use. It includes an impedance analyzer performing an excitation voltage of 0.2-2 Vpp and a frequency sweep of 11-101 kHz, function generator with the sine wave output at an operating voltage of 1-50 Vpp with a frequency of 4-12 MHz, cell-trapping biochip, microscope, and input/output interface. The biochip for the single cell trapping is designed and simulated based on a combination of ACET and DEP forces. In order to improve measurement accuracy, the curve fitting method is adopted to calibrate the proposed impedance spectroscopy. Measurement results from the proposed system are compared with results from a precision impedance analyzer. The trapped cell can be modeled for numerical analyses. Many advantages are offered in the proposed instrument such as the small volume, real-time monitoring, rapid analysis, low cost, low-power consumption, and portable application. PMID:24610717

Tsai, Sung-Lin; Chiang, Yang; Wang, Min-Haw; Chen, Ming-Kun; Jang, Ling-Sheng

2014-08-01

253

Biosphere Modeling and Analyses in Support of Total System Performance Assessment  

SciTech Connect

The Nuclear Waste Policy Act of 1982 established the obligations of and the relationship between the U.S. Environmental Protection Agency (EPA), the U.S. Nuclear Regulatory Commission (NRC), and the U.S. Department of Energy (DOE) for the management and disposal of high-level radioactive wastes. In 1985, the EPA promulgated regulations that included a definition of performance assessment that did not consider potential dose to a member of the general public. This definition would influence the scope of activities conducted by DOE in support of the total system performance assessment program until 1995. The release of a National Academy of Sciences (NAS) report on the technical basis for a Yucca Mountain-specific standard provided the impetus for the DOE to initiate activities that would consider the attributes of the biosphere, i.e. that portion of the earth where living things, including man, exist and interact with the environment around them. The evolution of NRC and EPA Yucca Mountain-specific regulations, originally proposed in 1999, was critical to the development and integration of biosphere modeling and analyses into the total system performance assessment program. These proposed regulations initially differed in the conceptual representation of the receptor of interest to be considered in assessing performance. The publication in 2001 of final regulations in which the NRC adopted standard will permit the continued improvement and refinement of biosphere modeling and analyses activities in support of assessment activities.

Jeff Tappen; M.A. Wasiolek; D.W. Wu; J.F. Schmitt

2001-12-06

254

Biosphere Modeling and Analyses in Support of Total System Performance Assessment  

SciTech Connect

The Nuclear Waste Policy Act of 1982 established the obligations of and the relationship between the U.S. Environmental Protection Agency (EPA), the U.S. Nuclear Regulatory Commission (NRC), and the U.S. Department of Energy (DOE) for the management and disposal of high-level radioactive wastes. In 1985, the EPA promulgated regulations that included a definition of performance assessment that did not consider potential dose to a member of the general public. This definition would influence the scope of activities conducted by DOE in support of the total system performance assessment program until 1995. The release of a National Academy of Sciences (NAS) report on the technical basis for a Yucca Mountain-specific standard provided the impetus for the DOE to initiate activities that would consider the attributes of the biosphere, i.e. that portion of the earth where living things, including man, exist and interact with the environment around them. The evolution of NRC and EPA Yucca Mountain-specific regulations, originally proposed in 1999, was critical to the development and integration of biosphere modeling and analyses into the total system performance assessment program. These proposed regulations initially differed in the conceptual representation of the receptor of interest to be considered in assessing performance. The publication in 2001 of final regulations in which the NRC adopted standard will permit the continued improvement and refinement of biosphere modeling and analyses activities in support of assessment activities.

Tappen, J. J.; Wasiolek, M. A.; Wu, D. W.; Schmitt, J. F.; Smith, A. J.

2002-02-26

255

Advances in Omics and Bioinformatics Tools for Systems Analyses of Plant Functions  

PubMed Central

Omics and bioinformatics are essential to understanding the molecular systems that underlie various plant functions. Recent game-changing sequencing technologies have revitalized sequencing approaches in genomics and have produced opportunities for various emerging analytical applications. Driven by technological advances, several new omics layers such as the interactome, epigenome and hormonome have emerged. Furthermore, in several plant species, the development of omics resources has progressed to address particular biological properties of individual species. Integration of knowledge from omics-based research is an emerging issue as researchers seek to identify significance, gain biological insights and promote translational research. From these perspectives, we provide this review of the emerging aspects of plant systems research based on omics and bioinformatics analyses together with their associated resources and technological advances. PMID:22156726

Mochida, Keiichi; Shinozaki, Kazuo

2011-01-01

256

Satellite Power System (SPS) concept definition study (Exhibit D). Volume 2: Systems/subsystems analyses  

NASA Technical Reports Server (NTRS)

Modifications to the reference concept were studied and the best approaches defined. The impact of the high efficiency multibandgap solar array on the reference concept design is considered. System trade studies for several solid state concepts, including the sandwich concept and a separate antenna/solar concept, are described. Two solid state concepts were selected and a design definition is presented for each. Magnetrons as an alternative to the reference klystrons for dc/RF conversion are evaluated. System definitions are presented for the preferred klystron and solid state concepts. Supporting systems are analyzed, with major analysis in the microwave, structures, and power distribution areas. Results of studies for thermal control, attitude control, stationkeeping, and details of a multibandgap solar cell study are included. Advanced laser concepts and the meteorological effects of a laser beam power transmission concept are considered.

Hanley, G. M.

1981-01-01

257

Bioinformatic analyses of the bacterial L-ascorbate phosphotransferase system permease family.  

PubMed

The tripartite L-ascorbate permease of Escherichia coli is the first functionally characterized member of a large family of enzyme II complexes (SgaTBA, encoding enzymes IIC, IIB and IIA) of the bacterial phosphotransferase system (PTS). We here report bioinformatic analyses of these proteins. Forty-five homologous systems from a wide variety of bacteria were identified, but no homologues were found in archaea or eukaryotes. These systems fell into five structural types: (1) IIC, IIB and IIA are encoded by distinct genes; (2) IIC and IIB are encoded by distinct genes, but the IIA-encoding gene is absent; (3) IIC and IIB are encoded by a fused gene, but IIA is a distinct gene product; (4) IIA and IIB are fused, but IIC is encoded by a distinct gene, and (5) IIC and IIB are encoded by distinct genes, but IIA is fused to a transcriptional regulator. Phylogenetic analyses revealed that gene fusion/splicing events have occurred repeatedly during the evolutionary divergence of family members, although no evidence for shuffling of constituents between systems was obtained. The SgaTBA family proved to be distantly related to the GatCBA family of PTS permeases, and this family was also analyzed. In contrast to the SgaTBA family, no gene splicing/fusion has occurred during the evolutionary divergence of GatCBA family members as each domain is always encoded by a distinct gene. However, GatC homologues were identified in organisms that lack other PTS proteins, suggesting a transport mechanism not coupled to substrate phosphorylation. Topological analyses suggest that in contrast to all other PTS permeases, IIC proteins of the Sga and Gat families exhibit 12 transmembrane alpha-helical segments and are distantly related to secondary carriers. Like many secondary carriers, GatC (IIC) homologues could be shown to have arisen by an ancient intragenic duplication event. These results suggest that the Sga and Gat families of PTS permeases comprise a small superfamily in which the transmembrane IIC domains evolved independently of all other known PTS permeases. PMID:15153772

Hvorup, Rikki; Chang, Abraham B; Saier, Milton H

2003-01-01

258

Safety and Environmental Activities for ITER  

NASA Astrophysics Data System (ADS)

This paper will summarize highlights of the safety approach and discuss the ITER EDA safety activities. The ITER safety approach is driven by three major objectives: (1) Enhancement or improvement of fusion's intrinsic safety characteristics to the maximum extent feasible, which includes a minimization of the dependence on dedicated “safety systems”; (2) Selection of conservative design parameters and development of a robust design to accommodate uncertainties in plasma physics as well as the lack of operational experience and data; and (3) Integration of engineered mitigation systems to enhance the safety assurance against potentially hazardous inventories in the device by deploying well-established “nuclear safety” approaches and methodologies tailored as appropriate for ITER.

Saji, G.; Aymar, R.; Bartels, H.-W.; Gordon, C. W.; Gulden, W.; Holl, D. H.; Iida, H.; Inabe, T.; Iseli, M.; Kashirski, A. V.; Kolbasov, B. N.; Krivosheev, M.; McCarthy, K. A.; Marbach, G.; Morozov, S. I.; Natalizio, A.; Petti, D. A.; Piet, S. J.; Poucet, A. E.; Raeder, J.; Seki, Y.; Topilski, L. N.

1997-09-01

259

Iterable AGM Functions Carlos Areces  

E-print Network

Iterable AGM Functions Carlos Areces e-mail: carlos@wins.uva.nl Results in: \\Iterable AGM Functions. We show in this way that the AGM formalism is indeed compatible with iteration. c Carlos Eduardo is to Come. c Carlos Eduardo Areces. ILLC. University of Amsterdam #12;2. Iteration. A Discussion Iterated

Figueira, Santiago

260

Progress of IRSN R&D on ITER Safety Assessment  

NASA Astrophysics Data System (ADS)

The French "Institut de Radioprotection et de Sûreté Nucléaire" (IRSN), in support to the French "Autorité de Sûreté Nucléaire", is analysing the safety of ITER fusion installation on the basis of the ITER operator's safety file. IRSN set up a multi-year R&D program in 2007 to support this safety assessment process. Priority has been given to four technical issues and the main outcomes of the work done in 2010 and 2011 are summarized in this paper: for simulation of accident scenarios in the vacuum vessel, adaptation of the ASTEC system code; for risk of explosion of gas-dust mixtures in the vacuum vessel, adaptation of the TONUS-CFD code for gas distribution, development of DUST code for dust transport, and preparation of IRSN experiments on gas inerting, dust mobilization, and hydrogen-dust mixtures explosion; for evaluation of the efficiency of the detritiation systems, thermo-chemical calculations of tritium speciation during transport in the gas phase and preparation of future experiments to evaluate the most influent factors on detritiation; for material neutron activation, adaptation of the VESTA Monte Carlo depletion code. The first results of these tasks have been used in 2011 for the analysis of the ITER safety file. In the near future, this R&D global programme may be reoriented to account for the feedback of the latter analysis or for new knowledge.

Van Dorsselaere, J. P.; Perrault, D.; Barrachin, M.; Bentaib, A.; Gensdarmes, F.; Haeck, W.; Pouvreau, S.; Salat, E.; Seropian, C.; Vendel, J.

2012-08-01

261

Stream restoration in dynamic fluvial systems: Scientific approaches, analyses, and tools  

NASA Astrophysics Data System (ADS)

In the United States the average annual investment in river restoration programs is approximately $1 billion. Despite this burgeoning industry, the National Water Quality Inventory, which tracks the health of the nation's rivers, has shown no serious improvement in cumulative river health since the early 1990s. In the AGU monograph Stream Restoration in Dynamic Fluvial Systems: Scientific Approaches, Analyses, and Tools, editors Andrew Simon, Sean J. Bennett, and Janine M. Castro pull together the latest evidence-based understanding of stream restoration practices, with an aim of guiding the further development of the field and helping to right its apparently unsuccessful course. In this interview, Eos talks to Sean J. Bennett, University of Buffalo, about the culture, practice, and promise of restoring rivers.

Schultz, Colin

2012-04-01

262

Error analyses and calibration methods with accelerometers for optical angle encoders in rotational inertial navigation systems.  

PubMed

By rotating a strapdown inertial navigation system (INS) over one or more axes, a number of error sources originating from the employed sensors cancel out during the integration process. Rotary angle accuracy has an effect on the performance of rotational INS (RINS). The application of existing calibration methods based on gyroscope measurements is restricted by the structure of the inertial measurement unit (IMU) and scale factor stability of the gyroscope. The multireadhead method has problems in miniaturization and cost. Hence, optical angle encoder calibration methods using accelerometers are proposed, on the basis of navigation error and accuracy requirement analyses for a single-axis RINS. The test results show that the accuracy of calibration methods proposed is higher than 4 arcsec (1?). PMID:24216731

Liu, Fang; Wang, Wei; Wang, Lei; Feng, Peide

2013-11-10

263

Iteration, Not Induction  

ERIC Educational Resources Information Center

The main purpose of this note is to present and justify proof via iteration as an intuitive, creative and empowering method that is often available and preferable as an alternative to proofs via either mathematical induction or the well-ordering principle. The method of iteration depends only on the fact that any strictly decreasing sequence of…

Dobbs, David E.

2009-01-01

264

Iterative image restoration algorithms  

Microsoft Academic Search

This tutorial paper discusses the use of successive-approximation- based iterative restoration algorithms for the removal of linear blurs and noise from images. Iterative algorithms are particularly attractive for this application because they allow for the incorporation of prior knowledge about the class of feasible solutions, because they can be used to remove nonstationary blurs, and because they are fairly robust

Aggelos K. Katsaggelos

265

Performance Analyses of 38 kWe Turbo-Machine Unit for Space Reactor Power Systems  

SciTech Connect

This paper developed a design and investigated the performance of 38 kWe turbo-machine unit for space nuclear reactor power systems with Closed Brayton Cycle (CBC) energy conversion. The compressor and turbine of this unit are scaled versions of the NASA's BRU developed in the sixties and seventies. The performance results of turbo-machine unit are calculated for rotational speed up to 45 krpm, variable reactor thermal power and system pressure, and fixed turbine and compressor inlet temperatures of 1144 K and 400 K. The analyses used a detailed turbo-machine model developed at University of New Mexico that accounts for the various energy losses in the compressor and turbine and the effect of compressibility of the He-Xe (40 mole/g) working fluid with increased flow rate. The model also accounts for the changes in the physical and transport properties of the working fluid with temperature and pressure. Results show that a unit efficiency of 24.5% is achievable at rotation speed of 45 krpm and system pressure of 0.75 MPa, assuming shaft and electrical generator efficiencies of 86.7% and 90%. The corresponding net electric power output of the unit is 38.5 kWe, the flow rate of the working fluid is 1.667 kg/s, the pressure ratio and polytropic efficiency for the compressor are 1.60 and 83.1%, and 1.51 and 88.3% for the turbine.

Gallo, Bruno M.; El-Genk, Mohamed S. [Institute for Space and Nuclear Power Studies and Chemical and Nuclear Engineering Department, University of New Mexico, Albuquerque, NM, 87131 (United States)

2008-01-21

266

Single-particle and many-body analyses of a quasiperiodic integrable system after a quench  

NASA Astrophysics Data System (ADS)

In general, isolated integrable quantum systems have been found to relax to an apparent equilibrium state in which the expectation values of few-body observables are described by the generalized Gibbs ensemble. However, recent work has shown that relaxation to such a generalized statistical ensemble can be precluded by localization in a quasiperiodic lattice system. Here we undertake complementary single-particle and many-body analyses of noninteracting spinless fermions and hard-core bosons within the Aubry-André model to gain insight into this phenomenon. Our investigations span both the localized and delocalized regimes of the quasiperiodic system, as well as the critical point separating the two. Considering first the case of spinless fermions, we study the dynamics of the momentum distribution function and characterize the effects of real-space and momentum-space localization on the relevant single-particle wave functions and correlation functions. We show that although some observables do not relax in the delocalized and localized regimes, the observables that do relax in these regimes do so in a manner consistent with a recently proposed Gaussian equilibration scenario, whereas relaxation at the critical point has a more exotic character. We also construct various statistical ensembles from the many-body eigenstates of the fermionic and bosonic Hamiltonians and study the effect of localization on their properties.

He, Kai; Santos, Lea F.; Wright, Tod M.; Rigol, Marcos

2013-06-01

267

Results of the implementation on a mock-up of the full 3dB hybrid matching option of the ITER ICRH system  

SciTech Connect

Each of the two ICRH antennas for ITER must couple 20MW to the plasma in the 40-55MHz band via an array of 24 radiating shorted straps fed by four generators. The matching system must provide automatic matching control on the mean load provided by the plasma and be resilient (parallel {Gamma}{sub G} parallel <0.2) to a wide range of fast antenna load excursions occurring in ELMy plasmas. Furthermore, good control of the current distribution in the strap array must be possible for the various heating and current drive scenarios. Two load resilient matching options have been considered for ITER: the 4 'Conjugate-T'(CT) and the 4 hybrids ones, the first being presently considered as a back-up option. Automatic control of these 2 options has been developed, and tested for optimization on a low-powered scaled mock-up. Successful implementation of the simultaneous feedback control of 11 actuators for the matching of the 4 CT and for the control of the toroidal phasing has already been achieved. The matching and the array current control of the 3dB hybrid option are provided by simultaneous feedback control of the decouplers and double stub tuners (in total 23 actuators) and this has also been successfully achieved for the full array. The paper discusses the circuit implementation and presents the obtained results.

Grine, D.; Vervier, M.; Messiaen, A.; Dumortier, P. [LPP-ERM/KMS, EURATOM-Belgian State Association, TEC, Brussels (Belgium)

2011-12-23

268

System Evaluations and Life-Cycle Cost Analyses for High-Temperature Electrolysis Hydrogen Production Facilities  

SciTech Connect

This report presents results of system evaluations and lifecycle cost analyses performed for several different commercial-scale high-temperature electrolysis (HTE) hydrogen production concepts. The concepts presented in this report rely on grid electricity and non-nuclear high-temperature process heat sources for the required energy inputs. The HYSYS process analysis software was used to evaluate both central plant designs for large-scale hydrogen production (50,000 kg/day or larger) and forecourt plant designs for distributed production and delivery at about 1,500 kg/day. The HYSYS software inherently ensures mass and energy balances across all components and it includes thermodynamic data for all chemical species. The optimized designs described in this report are based on analyses of process flow diagrams that included realistic representations of fluid conditions and component efficiencies and operating parameters for each of the HTE hydrogen production configurations analyzed. As with previous HTE system analyses performed at the INL, a custom electrolyzer model was incorporated into the overall process flow sheet. This electrolyzer model allows for the determination of the average Nernst potential, cell operating voltage, gas outlet temperatures, and electrolyzer efficiency for any specified inlet steam, hydrogen, and sweep-gas flow rates, current density, cell active area, and external heat loss or gain. The lifecycle cost analyses were performed using the H2A analysis methodology developed by the Department of Energy (DOE) Hydrogen Program. This methodology utilizes spreadsheet analysis tools that require detailed plant performance information (obtained from HYSYS), along with financial and cost information to calculate lifecycle costs. There are standard default sets of assumptions that the methodology uses to ensure consistency when comparing the cost of different production or plant design options. However, these assumptions may also be varied within the spreadsheets when better information is available or to allow the performance of sensitivity studies. The selected reference plant design for this study was a 1500 kg/day forecourt hydrogen production plant operating in the thermal-neutral mode. The plant utilized industrial natural gas-fired heaters to provide process heat, and grid electricity to supply power to the electrolyzer modules and system components. Modifications to the reference design included replacing the gas-fired heaters with electric resistance heaters, changing the operating mode of the electrolyzer (to operate below the thermal-neutral voltage), and considering a larger 50,000 kg/day central hydrogen production plant design. Total H2A-calculated hydrogen production costs for the reference 1,500 kg/day forecourt hydrogen production plant were $3.42/kg. The all-electric plant design using electric resistance heaters for process heat, and the reference design operating below the thermal-neutral voltage had calculated lifecycle hydrogen productions costs of $3.55/kg and $5.29/kg, respectively. Because of its larger size and associated economies of scale, the 50,000 kg/day central hydrogen production plant was able to produce hydrogen at a cost of only $2.89/kg.

Edwin A. Harvego; James E. O'Brien; Michael G. McKellar

2012-05-01

269

Additional Development and Systems Analyses of Pneumatic Technology for High Speed Civil Transport Aircraft  

NASA Technical Reports Server (NTRS)

In the Task I portion of this NASA research grant, configuration development and experimental investigations have been conducted on a series of pneumatic high-lift and control surface devices applied to a generic High Speed Civil Transport (HSCT) model configuration to determine their potential for improved aerodynamic performance, plus stability and control of higher performance aircraft. These investigations were intended to optimize pneumatic lift and drag performance; provide adequate control and longitudinal stability; reduce separation flowfields at high angle of attack; increase takeoff/climbout lift-to-drag ratios; and reduce system complexity and weight. Experimental aerodynamic evaluations were performed on a semi-span HSCT generic model with improved fuselage fineness ratio and with interchangeable plain flaps, blown flaps, pneumatic Circulation Control Wing (CCW) high-lift configurations, plain and blown canards, a novel Circulation Control (CC) cylinder blown canard, and a clean cruise wing for reference. Conventional tail power was also investigated for longitudinal trim capability. Also evaluated was unsteady pulsed blowing of the wing high-lift system to determine if reduced pulsed mass flow rates and blowing requirements could be made to yield the same lift as that resulting from steady-state blowing. Depending on the pulsing frequency applied, reduced mass flow rates were indeed found able to provide lift augmentation at lesser blowing values than for the steady conditions. Significant improvements in the aerodynamic characteristics leading to improved performance and stability/control were identified, and the various components were compared to evaluate the pneumatic potential of each. Aerodynamic results were provided to the Georgia Tech Aerospace System Design Lab. to conduct the companion system analyses and feasibility study (Task 2) of theses concepts applied to an operational advanced HSCT aircraft. Results and conclusions from these experimental evaluations are presented herein, as are recommendations for further development and follow-on investigations. Also provided as an Appendix for reference are the basic results from the previous pneumatic HSCT investigations.

Englar, Robert J.; Willie, F. Scott; Lee, Warren J.

1999-01-01

270

Genomic and Systems Biology Analyses of Social Behavior or Evolutionary Genomic Analyses of Insect Society: Eat, Drink, and Be Scary (2011 JGI User Meeting)  

SciTech Connect

The U.S. Department of Energy Joint Genome Institute (JGI) invited scientists interested in the application of genomics to bioenergy and environmental issues, as well as all current and prospective users and collaborators, to attend the annual DOE JGI Genomics of Energy & Environment Meeting held March 22-24, 2011 in Walnut Creek, Calif. The emphasis of this meeting was on the genomics of renewable energy strategies, carbon cycling, environmental gene discovery, and engineering of fuel-producing organisms. The meeting features presentations by leading scientists advancing these topics. Gene Robinson of the University of Illinois on "Genomic and Systems Biology Analyses of Social Behavior" at the 6th Annual Genomics of Energy & Environment Meeting on March 23, 2011

Robinson, Gene

2011-03-23

271

Genomic and Systems Biology Analyses of Social Behavior or Evolutionary Genomic Analyses of Insect Society: Eat, Drink, and Be Scary (2011 JGI User Meeting)  

ScienceCinema

The U.S. Department of Energy Joint Genome Institute (JGI) invited scientists interested in the application of genomics to bioenergy and environmental issues, as well as all current and prospective users and collaborators, to attend the annual DOE JGI Genomics of Energy & Environment Meeting held March 22-24, 2011 in Walnut Creek, Calif. The emphasis of this meeting was on the genomics of renewable energy strategies, carbon cycling, environmental gene discovery, and engineering of fuel-producing organisms. The meeting features presentations by leading scientists advancing these topics. Gene Robinson of the University of Illinois on "Genomic and Systems Biology Analyses of Social Behavior" at the 6th Annual Genomics of Energy & Environment Meeting on March 23, 2011

Robinson, Gene

2011-06-03

272

Tritium inventory assessment for ITER using TRIMO  

Microsoft Academic Search

Currently, the strategy for determination of ITER in-vessel tritium inventory envisages that at predetermined intervals, tritiated gases in all systems of fuel cycle will be transferred to the storage and delivery system (SDS) and tritium quantities measured by in-bed calorimetry. The isotope separation system (ISS) is the system used to separate hydrogen isotopes at the quality required to be stored

Ioana-R. Cristescu; I. Cristescu; D. Murdoch; L. Dörr; M. Glugla

2006-01-01

273

DQS advisor: a visual interface and knowledge-based system to balance dose, quality, and reconstruction speed in iterative CT reconstruction with application to NLM-regularization.  

PubMed

Motivated by growing concerns with regards to the x-ray dose delivered to the patient, low-dose computed tomography (CT) has gained substantial interest in recent years. However, achieving high-quality CT reconstructions from the limited projection data collected at reduced x-ray radiation is challenging, and iterative algorithms have been shown to perform much better than conventional analytical schemes in these cases. A problem with iterative methods in general is that they require users to set many parameters, and if set incorrectly high reconstruction time and/or low image quality are likely consequences. Since the interactions among parameters can be complex and thus effective settings can be difficult to identify for a given scanning scenario, these choices are often left to a highly-experienced human expert. To help alleviate this problem, we devise a computer-based assistant for this purpose, called dose, quality and speed (DQS)-advisor. It allows users to balance the three most important CT metrics--DQS--by ways of an intuitive visual interface. Using a known gold-standard, the system uses the ant-colony optimization algorithm to generate the most effective parameter settings for a comprehensive set of DQS configurations. A visual interface then presents the numerical outcome of this optimization, while a matrix display allows users to compare the corresponding images. The interface allows users to intuitively trade-off GPU-enabled reconstruction speed with quality and dose, while the system picks the associated parameter settings automatically. Further, once the knowledge has been generated, it can be used to correctly set the parameters for any new CT scan taken at similar scenarios. PMID:24145253

Zheng, Z; Papenhausen, E; Mueller, K

2013-11-01

274

DQS advisor: a visual interface and knowledge-based system to balance dose, quality, and reconstruction speed in iterative CT reconstruction with application to NLM-regularization  

NASA Astrophysics Data System (ADS)

Motivated by growing concerns with regards to the x-ray dose delivered to the patient, low-dose computed tomography (CT) has gained substantial interest in recent years. However, achieving high-quality CT reconstructions from the limited projection data collected at reduced x-ray radiation is challenging, and iterative algorithms have been shown to perform much better than conventional analytical schemes in these cases. A problem with iterative methods in general is that they require users to set many parameters, and if set incorrectly high reconstruction time and/or low image quality are likely consequences. Since the interactions among parameters can be complex and thus effective settings can be difficult to identify for a given scanning scenario, these choices are often left to a highly-experienced human expert. To help alleviate this problem, we devise a computer-based assistant for this purpose, called dose, quality and speed (DQS)-advisor. It allows users to balance the three most important CT metrics--DQS--by ways of an intuitive visual interface. Using a known gold-standard, the system uses the ant-colony optimization algorithm to generate the most effective parameter settings for a comprehensive set of DQS configurations. A visual interface then presents the numerical outcome of this optimization, while a matrix display allows users to compare the corresponding images. The interface allows users to intuitively trade-off GPU-enabled reconstruction speed with quality and dose, while the system picks the associated parameter settings automatically. Further, once the knowledge has been generated, it can be used to correctly set the parameters for any new CT scan taken at similar scenarios.

Zheng, Z.; Papenhausen, E.; Mueller, K.

2013-11-01

275

Wind Power Forecasting Error Frequency Analyses for Operational Power System Studies: Preprint  

SciTech Connect

The examination of wind power forecasting errors is crucial for optimal unit commitment and economic dispatch of power systems with significant wind power penetrations. This scheduling process includes both renewable and nonrenewable generators, and the incorporation of wind power forecasts will become increasingly important as wind fleets constitute a larger portion of generation portfolios. This research considers the Western Wind and Solar Integration Study database of wind power forecasts and numerical actualizations. This database comprises more than 30,000 locations spread over the western United States, with a total wind power capacity of 960 GW. Error analyses for individual sites and for specific balancing areas are performed using the database, quantifying the fit to theoretical distributions through goodness-of-fit metrics. Insights into wind-power forecasting error distributions are established for various levels of temporal and spatial resolution, contrasts made among the frequency distribution alternatives, and recommendations put forth for harnessing the results. Empirical data are used to produce more realistic site-level forecasts than previously employed, such that higher resolution operational studies are possible. This research feeds into a larger work of renewable integration through the links wind power forecasting has with various operational issues, such as stochastic unit commitment and flexible reserve level determination.

Florita, A.; Hodge, B. M.; Milligan, M.

2012-08-01

276

Preliminary analyses of WL experiment No. 701, space environment effects on operating fiber optic systems  

NASA Technical Reports Server (NTRS)

A brief overview of the analyses performed to date on WL Experiment-701 is presented. Four active digital fiber optic links were directly exposed to the space environment for a period of 2114 days. The links were situated aboard the Long Duration Exposure Facility (LDEF) with the cabled, single fiber windings atop an experimental tray containing instrumentation for exercising the experiment in orbit. Despite the unplanned and prolonged exposure to trapped and galactic radiation, wide temperature extremes, atomic oxygen interactions, and micro-meteorite and debris impacts, in most instances the optical data links performed well within the experimental limits. Analysis of the recorded orbital data clearly indicates that fiber optic applications in space will meet with success. Ongoing tests and analysis of the experiment at the Phillips Laboratory's Optoelectronics Laboratory will expand this premise, and establish the first known and extensive database of active fiber optic link performance during prolonged space exposure. WL Exp-701 was designed as a feasibility demonstration for fiber optic technology in space applications, and to study the performance of operating fiber systems exposed to space environmental factors such as galactic radiation, and wide temperature cycling. WL Exp-701 is widely acknowledged as a benchmark accomplishment that clearly demonstrates, for the first time, that fiber optic technology can be successfully used in a variety of space applications.

Taylor, E. W.; Berry, J. N.; Sanchez, A. D.; Padden, R. J.; Chapman, S. P.

1992-01-01

277

Synchrotron X-ray Analyses Demonstrate Phosphate-Bound Gadolinium in Skin in Nephrogenic Systemic Fibrosis  

PubMed Central

Background Nephrogenic systemic fibrosis (NSF) is an incurable, debilitating disease found exclusively in patients with decreased kidney function and comprises a fibrosing disorder of the skin and systemic tissues. The disease is associated with exposure to Gadolinium based contrast agents (GBCA) used in magnetic resonance imaging (MRI). Tissue samples from many NSF patients contain micron-sized insoluble Gd-containing deposits. However, the precise composition and chemical nature of these particles is unclear. Objectives To clarify the precise chemical structure of the Gd-containing deposits in NSF tissues. Methods Autopsy skin tissues from a NSF patient are examined in situ using synchrotron x-ray fluorescence (SXRF) microscopy and extended absorption fine structure (EXAFS) spectroscopy and in correlation with light microscopy and the results of SEM/EDS analyses. Results The insoluble Gd deposits are shown to contain Gd no longer coordinated by GBCA chelator molecules but rather in a sodium calcium phosphate material. SXRF microscopy shows a clear correlation between Gd, Ca and P. EXAFS spectroscopy shows a very different spectrum from the GBCAs, with Gd-P distances at 3.11 Å and 3.72 Å as well as Gd-Gd distances at an average of 4.05 Å, consistent with a GdPO4 structure. Conclusions This is the first direct evidence for the chemical release of Gd from GBCA in human tissue. This supports the physical-chemical, clinical, and epidemiological data indicating a link between stability and dose of GBCA to the development of NSF. PMID:20560953

George, Simon J.; Webb, Samuel M.; Abraham, Jerrold L.; Cramer, Stephen P.

2010-01-01

278

US solid breeder blanket design for ITER  

SciTech Connect

The US blanket design activity has focused on the developments and the analyses of a solid breeder blanket concept for ITER. The main function of this blanket is to produce the necessary tritium required for the ITER operation and the test program. Safety, power reactor relevance, low tritium inventory, and design flexibility are the main reasons for the blanket selection. The blanket is designed to operate satisfactorily in the physics and the technology phases of ITER without the need for hardware changes. Mechanical simplicity, predictability, performance, minimum cost, and minimum R D requirements are the other criteria used to guide the design process. The design aspects of the blanket are summarized in this paper. 2 refs., 7 figs., 3 tabs.

Gohar, Y.; Attaya, H.; Billone, M.; Lin, C.; Johnson, C.; Majumdar, S.; Smith, D. (Argonne National Lab., IL (USA)); Goranson, P.; Nelson, B.; Williamson, D.; Baker, C. (Oak Ridge National Lab., TN (USA)); Raffray, A.; Badawi, A.; Gorbis, Z.; Ying, A.; Abdou, M. (California Univ., Los Angeles, CA (USA)); Sviatoslavsky, I.; Blanchard, J.; Mogahed, E.; Sawan, M.; Kulcinski, G. (Wisconsin Univ., Madison, WI (USA))

1990-09-01

279

ITER LIDAR performance analysis  

SciTech Connect

The core LIDAR Thomson scattering for ITER is specified for core profile measurements with a spatial resolution of 7 cm (a/30) for the range of 500 eV3x10{sup 19} m{sup -3} at an accuracy of <10% for T{sub e}. These specifications are verified using a full profile Monte Carlo simulation code. In the simulations it is assumed that the input transmission is 50% and the collection transmission is 10% for {lambda}=300-1200 nm and F/=6-17. A crucial design decision lies on the choice of laser and detector combination. It is evaluated that the system can meet its spatial and accuracy specifications for higher temperatures of T{sub e}>5 keV with a combination of a neodymium-doped yttrium aluminum garnet (Nd:YAG) laser ({lambda}{sub 0}=1064 nm, {delta}{lambda}<1 nm, 5 J, and {delta}t{sub FWHM}=250 ps, 5-10 Hz) and S20, GaAs, and GaAsP microchannel plate photomultipliers ({delta}t{sub FWHM}<300 ps, effective quantum efficiency, EQE=3%-4%, and D=18 mm). In order to reach the required T{sub e} of 500 eV with Nd:YAG first harmonic, this choice requires a development of fast near infrared detectors.

Beurskens, M. N. A.; Kempenaars, M.; Scannell, R.; Walsh, M. J. [EURATOM/UKAEA Fusion Association, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Giudicotti, L. [Consorzio RFX--Associazione Euratom-Enea, Padova 35127 (Italy)

2008-10-15

280

IEEE TRANSACTIONS ON COMPUTER-AIDED DESIGN OF INTEGRATED CIRCUITS AND SYSTEMS, VOL. 25, NO. 6, JUNE 2006 1087 SILCA: SPICE-Accurate Iterative Linear-Centric  

E-print Network

2006 1087 SILCA: SPICE-Accurate Iterative Linear-Centric Analysis for Efficient Time-Domain Simulation--A new circuit analysis method, named SPICE- accurate iterative linear-centric analysis (SILCA an order of magnitude speedup over SPICE3 in terms of both the cost of LU factorization and the overall CPU

Shi, C.-J. Richard

281

Scheduling and rescheduling with iterative repair  

NASA Technical Reports Server (NTRS)

This paper describes the GERRY scheduling and rescheduling system being applied to coordinate Space Shuttle Ground Processing. The system uses constraint-based iterative repair, a technique that starts with a complete but possibly flawed schedule and iteratively improves it by using constraint knowledge within repair heuristics. In this paper we explore the tradeoff between the informedness and the computational cost of several repair heuristics. We show empirically that some knowledge can greatly improve the convergence speed of a repair-based system, but that too much knowledge, such as the knowledge embodied within the MIN-CONFLICTS lookahead heuristic, can overwhelm a system and result in degraded performance.

Zweben, Monte; Davis, Eugene; Daun, Brian; Deale, Michael

1992-01-01

282

Systems biological analyses reveal the HCV-specific regulation of hematopoietic development.  

PubMed

Chronic liver disease is characterized by the liver enrichment of myeloid DCs. To assess the role of disease on myelopoiesis, we utilized a systems biology approach to study development in liver-resident cells expressing stem cell marker CD34. In patients with end-stage liver disease, liver CD34+ cells were comprised by two subsets, designated CD34+CD146+ and CD34+CD146-, and hematopoietic function was restricted to CD34+CD146- cells. Liver CD34 frequencies were reduced during nonalcoholic steatohepatitis (NASH) and chronic hepatitis C virus (HCV) compared to alcohol liver disease (ALD), and this reduction correlated with viral load in the HCV cohort. To better understand the relationship between liver CD34+CD146+ and CD34+CD146- subsets and any effects of disease on CD34 development, we used gene expression profiling and computational modeling to compare each subset during ALD and HCV. For CD34+CD146+ cells, increased expression of endothelial cell genes including von Willebrand factor, VE-cadherin and eNOS were observed when compared to CD34+CD146- cells, and minimal effects of ALD and HCV diseases on gene expression were observed. Importantly for CD34+CD146- cells, chronic HCV was associated with a distinct 'imprint' of programs related to cell cycle, DNA repair, chemotaxis, development, and activation, with an emphasis on myeloid and B lymphocyte lineages. This HCV signature was further translated in side-by-side analyses, where HCV CD34+CD146- cells demonstrated superior hematopoietic growth, colony formation, and diversification compared to ALD and NASH when cultured identically. Disease-associated effects on hematopoiesis were also evident by phenotypic alterations in the expression of CD14, HLA-DR and CD16 by myeloid progeny cells. Conclusion: Etiology drives progenitor fate within diseased tissues. The liver may be a useful source of hematopoietic cells for therapy, or as therapeutic targets. (Hepatology 2014;). PMID:25331524

Velazquez, Victoria M; Uebelhoer, Luke S; Thapa, Manoj; Ibegbu, Chris; Courtney, Cynthia; Bosinger, Steven E; Magliocca, Joseph F; Adams, Andrew B; Kirk, Allan D; Knechtle, Stuart J; Kalman, Daniel; Suthar, Mehul; Grakoui, Arash

2014-10-21

283

System and Cost Analyses of Broad-Band Fiber Loop Architectures  

Microsoft Academic Search

Analyses of four broadband fiber-optic subscriber loop architectures, including active (high-speed time division multiplexing (TDM)-based) and passive (dense wavelength division multiplexing (WDM)-based, WDM-based with an analog subcarrier-multiplexing overlay, and splitter-based) double-star topologies, are presented. The analyses focus on specific demonstrated architectures and use component cost projections based on learning curves to estimate future network costs on a per-subscriber basis. Also

Kevin W. Lu; Martin I. Eiger; Howard L. Lemberg

1990-01-01

284

Solid breeder blanket option for the ITER conceptual design  

SciTech Connect

A solid-breeder water-cooled blanket option was developed for ITER based on a multilayer configuration. The blanket uses beryllium for neutron multiplication and lithium oxide for tritium breeding. The material forms are sintered products for both material with 0.8 density factor. The lithium-6 enrichment is 90%. This blanket has the capability to accommodate a factor of two change in the neutron wall loading without violating the different design guidelines. The design philosophy adopted for the blanket is to produce the necessary tritium required for the ITER operation and to operate at power reactor conditions as much as possible. At the same time, the reliability and the safety aspects of the blanket are enhanced by the use of a low-pressure coolant and the separation of the tritium purge lines from the coolant system. The blanket modules are made by hot vacuum forming and diffusion bonding a double wall structure with integral cooling channels. The different aspects of the blanket design including tritium breeding, nuclear heat deposition, activation analyses, thermal-hydraulics, tritium inventory, structural analyses, and water coolant conditions are summarized in this paper. 12 refs., 2 figs., 1 tab.

Gohar, Y.; Attaya, H.; Billone, M.C.; Finn, P.; Majumdar, S.; Turner, L.R.; Baker, C.C.; Nelson, B.E.; Raffray, R. (Argonne National Lab., IL (USA); Oak Ridge National Lab., TN (USA); California Univ., Los Angeles, CA (USA))

1989-10-01

285

Assessment of stakeholder perceptions in water infrastructure projects using system-of-systems and binary probit analyses: a case study.  

PubMed

Globally, water management is evolving toward integrating participatory processes for decision-making to increase the sustainability of the decision outcome. Information about the perceptions and concerns of stakeholders needs to be readily available to those involved in the decision-making process early in the planning stage to assist in developing viable alternatives that may be implementable with limited public opposition and engender general consensus among stakeholders. The current literature does not identify an appropriate means to incorporate stakeholder views early in the preliminary planning stages without requiring relatively large time commitments or the physical presence of the key stakeholders for meetings and discussions. This study develops and demonstrates a decision-support framework that incorporates the system-of-systems school of thought with binary probit analysis to aid in efficient participatory processes by providing insight regarding the stakeholders' demographics and select behavioral characteristics in a decision-making process. The methodology first frames the water system as a system-of-systems, an approach that inherently pinpoints the necessity for diverse stakeholder involvement and maps the stakeholders in the system's hierarchy. Then, binary probit analyses are used to quantify the effect of stakeholder characteristics on the likelihood that (1) they perceive or do not perceive a need for new capital-intensive water infrastructure, and (2) they support or oppose new capital-intensive water infrastructure. A water system decision in the Sacramento-San Joaquin Delta serves as a case study to demonstrate the methodology. Data regarding stakeholder beliefs and perceptions were collected via a web-based survey deployed throughout Southern and Central California The study results indicate that individuals between 18 and 25 years, persons living solely with their spouse, persons associated with environmental stakeholder groups, and individuals who follow the news on local water issues have an increased likelihood of public opposition to new water infrastructure in the Sacramento-San Joaquin Delta. These groups would be those targeted to mitigate public opposition by measures such as attempting to promote further discussion, educational outreach, and incorporating incentives such as increasing jobs or incorporating ecosystem rehabilitation efforts around the area impacted by the project. PMID:23872216

Faust, Kasey; Abraham, Dulcy M; DeLaurentis, Dan

2013-10-15

286

Characterization of the Saframycin A Gene Cluster from Streptomyces lavendulae NRRL 11002 Revealing a Nonribosomal Peptide Synthetase System for Assembling the Unusual Tetrapeptidyl Skeleton in an Iterative Manner?†  

PubMed Central

Saframycin A (SFM-A), produced by Streptomyces lavendulae NRRL 11002, belongs to the tetrahydroisoquinoline family of antibiotics, and its core is structurally similar to the core of ecteinascidin 743, which is a highly potent antitumor drug isolated from a marine tunicate. In this study, the biosynthetic gene cluster for SFM-A was cloned and localized to a 62-kb contiguous DNA region. Sequence analysis revealed 30 genes that constitute the SFM-A gene cluster, encoding an unusual nonribosomal peptide synthetase (NRPS) system and tailoring enzymes and regulatory and resistance proteins. The results of substrate prediction and in vitro characterization of the adenylation specificities of this NRPS system support the hypothesis that the last module acts in an iterative manner to form a tetrapeptidyl intermediate and that the colinearity rule does not apply. Although this mechanism is different from those proposed for the SFM-A analogs SFM-Mx1 and safracin B (SAC-B), based on the high similarity of these systems, it is likely they share a common mechanism of biosynthesis as we describe here. Construction of the biosynthetic pathway of SFM-Y3, an aminated SFM-A, was achieved in the SAC-B producer (Pseudomonas fluorescens). These findings not only shed new insight on tetrahydroisoquinoline biosynthesis but also demonstrate the feasibility of engineering microorganisms to generate structurally more complex and biologically more active analogs by combinatorial biosynthesis. PMID:17981978

Li, Lei; Deng, Wei; Song, Jie; Ding, Wei; Zhao, Qun-Fei; Peng, Chao; Song, Wei-Wen; Tang, Gong-Li; Liu, Wen

2008-01-01

287

ITER instrumentation and control—Status and plans  

Microsoft Academic Search

The ITER instrumentation and control (I&C) system is the term encompassing all hardware and software required to operate ITER. It has two levels of hierarchy: the central I&C systems and the plant systems I&C. The central I&C systems comprise CODAC (Control, Data Access and Communication), the central interlock system (CIS) and the central safety systems (CSS). The central I&C systems

Anders Wallander; Lana Abadie; Haresh Dave; Franck Di Maio; Hitesh Kumar Gulati; Chandresh Hansalia; Didier Joonekindt; Jean-Yves Journeaux; Wolf-Dieter Klotz; Kirti Mahajan; Petri Makijarvi; Luigi Scibile; Denis Stepanov; Nadine Utzel; Izuru Yonekawa

2010-01-01

288

Magnet design technical report---ITER definition phase  

SciTech Connect

This report contains papers on the following topics: conceptual design; radiation damage of ITER magnet systems; insulation system of the magnets; critical current density and strain sensitivity; toroidal field coil structural analysis; stress analysis for the ITER central solenoid; and volt-second capabilities and PF magnet configurations.

Henning, C. (ed.)

1989-04-28

289

Analyses of the Effects of Global Change on Human Health and Welfare and Human Systems (SAP 4.6)  

EPA Science Inventory

EPA has announced the final report entitled, Synthesis and Assessment Product 4.6: Analyses of the Effects of Global Change on Human Health and Welfare and Human Systems . This Synthesis and Assessment Product 4.6 (SAP 4.6) focuses on impacts of global climate change, es...

290

Analyses of the Effects of Global Change on Human Health and Welfare and Human Systems (Sap 4.6)  

EPA Science Inventory

EPA has released the draft document, Analyses of the Effects of Global Change on Human Health and Welfare and Human Systems for public review and comment. The notice has been posted by NOAA/ Department of Commerce on behalf of the U.S. Climate Change Science Program (CCS...

291

Simulation and Analysis of the Hybrid Operating Mode in ITER  

SciTech Connect

The hybrid operating mode in ITER is examined with 0D systems analysis, 1.5D discharge scenario simulations using TSC and TRANSP, and the ideal MHD stability is discussed. The hybrid mode has the potential to provide very long pulses and significant neutron fluence if the physics regime can be produced in ITER. This paper reports progress in establishing the physics basis and engineering limitation for the hybrid mode in ITER.

Kessel, C.E.; Budny, R.V.; Indireshkumar, K.

2005-09-22

292

Videourodynamic and sphincter motor unit potential analyses in Parkinson's disease and multiple system atrophy  

PubMed Central

OBJECTIVES—Urinary dysfunction is a prominent autonomic feature in Parkinson's disease (PD) and multiple system atrophy (MSA), which is not only troublesome but also a cause of morbidity in these disorders. Recent advances in investigative uroneurology offer a better insight into the underlying pathophysiology and appropriate management for urinary dysfunction.?METHODS—twenty one patients with PD (15 men, six women, mean age 64 (49-76), mean disease duration 4 years (1-8 years), median Hoehn and Yahr grade 3 (1-4), all taking 300 mg/day of levodopa (100-500 mg)) and 15 with MSA (eight men, seven women, mean age 59 (48-72), mean disease duration 3 years (0.5-6 years)) were recruited. Videourodynamic and sphincter motor unit potential analyses in the patients with PD and MSA were carried out, looking for distinguishing hallmarks that might be useful in the differential diagnosis of these two diseases.?RESULTS—Urinary symptoms were found in 72% of patients with PD and in 100% with MSA. Filling phase abnormalities in the videourodynamic study included detrusor hyperreflexia in 81% of patients with PD and 56% with MSA, and uninhibited external sphincter relaxation in 33% of patients with PD and 33% of those with MSA. However, open bladder neck at the start of filling was not seen in patients with PD but was present in 53% of those with MSA, suggestive of internal sphincter denervation. Sphincter motor unit potential analysis showed neurogenic motor unit potentials in 5% of patients with PD and in 93% of those with MSA, suggestive of external sphincter denervation. On voiding, detrusor-external sphincter dyssynergia was not seen in patients with PD but was present in 47% of those with MSA. Pressure-flow analysis showed that the Abrams-Griffiths number, a grading of urethral obstruction (outflow obstruction >40), in PD (40 in women and 43 in men) was larger than that in MSA (12 in women and 28 in men). Weak detrusor in PD (66% of women and 40% of men) was less common than that in MSA (71% of women and 63% of men). Postmicturition residuals >100 ml were absent in patients with PD but were present in 47% of patients with MSA.?CONCLUSION—Patients with PD had less severe urinary dysfunction with little evidence of internal or external sphincter denervation, by contrast with the common findings in MSA. The findings of postmicturition residuals >100 ml, detrusor-external sphincter dyssynergia, open bladder neck at the start of bladder filling, and neurogenic sphincter motor unit potentials are highly suggestive of MSA.?? PMID:11606669

Sakakibara, R; Hattori, T; Uchiyama, T; Yamanishi, T

2001-01-01

293

Theoretical and Experimental Analyses of Photovoltaic Systems with Voltage and Current-Based Maximum Power Point Tracking  

Microsoft Academic Search

Detailed theoretical and experimental analyses are presented for the comparison of two simple fast and reliable maximum power point tracking (MPPT) techniques for photovoltaic systems (PV): the voltage-based (VMPPT) and the current-based (CMPPT) approaches. A microprocessor-controlled tracker capable of online voltage and current measurements and programmed with both VMPPT and CMPPT algorithms is constructed. The load of the solar system

M. A. Masoum; H. Dehbonei; E. F. Fuchs

2002-01-01

294

Performance and radiological analyses of a space reactor power system deployed into a 1000–3000 km earth orbit  

Microsoft Academic Search

This paper presents the results of performance and radiological analyses of a space reactor power system to support space-based, radar satellites in a 1000–3000km orbit for global civilian air and ocean traffic control. The power system with six primary and secondary loops to avoid single point failures in reactor cooling and energy conversion employs a sectored, liquid NaK-78 cooled fission

Mohamed S. El-Genk; Timothy M. Schriener

2010-01-01

295

The Dynamics of Some Iterative Implicit Schemes  

NASA Technical Reports Server (NTRS)

The global asymptotic nonlinear behavior of some standard iterative procedures in solving nonlinear systems of algebraic equations arising from four implicit linear multistep methods (LMMs) in discretizing 2 x 2 systems of first-order autonomous nonlinear ordinary differential equations is analyzed using the theory of dynamical systems. With the aid of parallel Connection Machines (CM-2 and CM-5), the associated bifurcation diagrams as a function of the time step, and the complex behavior of the associated 'numerical basins of attraction' of these iterative implicit schemes are revealed and compared. Studies showed that all of the four implicit LMMs exhibit a drastic distortion and segmentation but less shrinkage of the basin of attraction of the true solution than standard explicit methods. The numerical basins of attraction of a noniterative implicit procedure mimic more closely the basins of attraction of the differential equations than the iterative implicit procedures for the four implicit LMMs.

Yee, H. C.; Sweby, P. K.

1994-01-01

296

Overview on Experiments On ITER-like Antenna On JET And ICRF Antenna Design For ITER  

SciTech Connect

Following an overview of the ITER Ion Cyclotron Resonance Frequency (ICRF) system, the JET ITER-like antenna (ILA) will be described. The ILA was designed to test the following ITER issues: (a) reliable operation at power densities of order 8 MW/m{sup 2} at voltages up to 45 kV using a close-packed array of straps; (b) powering through ELMs using an internal (in-vacuum) conjugate-T junction; (c) protection from arcing in a conjugate-T configuration, using both existing and novel systems; and (d) resilience to disruption forces. ITER-relevant results have been achieved: operation at high coupled power density; control of the antenna matching elements in the presence of high inter-strap coupling, use of four conjugate-T systems (as would be used in ITER, should a conjugate-T approach be used); operation with RF voltages on the antenna structures up to 42 kV; achievement of ELM tolerance with a conjugate-T configuration by operating at 3{omega} real impedance at the conjugate-T point; and validation of arc detection systems on conjugate-T configurations in ELMy H-mode plasmas. The impact of these results on the predicted performance and design of the ITER antenna will be reviewed. In particular, the implications of the RF coupling measured on JET will be discussed.

Nightingale, M. P. S.; Blackman, T.; Edwards, D.; Fanthome, J.; Graham, M.; Hamlyn-Harris, C.; Hancock, D.; Jacquet, P.; Mayoral, M.-L.; Monakhov, I.; Nicholls, K.; Stork, D.; Whitehurst, A.; Wilson, D.; Wooldridge, E. [EURATOM/UKAEA Fusion Association, Culham Science Centre, Abingdon, Oxon, OX14 3DB (United Kingdom); Durodie, F.; Dumortier, P.; Huygen, S.; Koch, R.; Lerche, E. [Laboratory for Plasma Physics, Ecole Royale Militaire/Koninklijke Militaire School, Association Euratom-Belgian State, Avenue de la Renaissance 30, B-1000 Brussels (Belgium)] (and others)

2009-11-26

297

Design/cost tradeoff studies. Appendix A. Supporting analyses and tradeoffs, book 2. Earth Observatory Satellite system definition study (EOS)  

NASA Technical Reports Server (NTRS)

Attitude reference systems for use with the Earth Observatory Satellite (EOS) are described. The systems considered are fixed and gimbaled star trackers, star mappers, and digital sun sensors. Covariance analyses were performed to determine performance for the most promising candidate in low altitude and synchronous orbits. The performance of attitude estimators that employ gyroscopes which are periodically updated by a star sensor is established by a single axis covariance analysis. The other systems considered are: (1) the propulsion system design, (2) electric power and electrical integration, (3) thermal control, (4) ground data processing, and (5) the test plan and cost reduction aspects of observatory integration and test.

1974-01-01

298

Strategic Petroleum Reserve (SPR) long-term monitoring system pressure data analyses  

Microsoft Academic Search

This report describes analyses of high-resolution pressure data collected on Caverns 2 and 110 at the Bryan Mound, Texas, Strategic Petroleum Reserve (SPR) site. A model of cavern pressurization is developed and applied to the two caverns. Use of the model to detect cavern pressure anomalies is demonstrated. Recommendatons are provided for improvements in pressure monitoring and cavern operation to

Biringer

1987-01-01

299

Final Report on ITER Task Agreement 81-18  

SciTech Connect

During 2007, the US International Thermonuclear Experimental Reactor (ITER) Project Office (USIPO) entered into a Task Agreement (TA) with the ITER International Organization (IO) to conduct Research and Development activity and/or Design activity in the area of Safety Analyses. There were four tasks within this TA, which were to provide the ITER IO with: 1) Quality Assurance (QA) documentation for the MELCOR 1.8.2 Fusion code, 2) a pedigreed version of MELCOR 1.8.2, 3) assistance in MELCOR input deck development and accident analyses, and 4) support and assistance in the operation of the MELCOR 1.8.2. This report, which is the final report for this agreement, documents the completion of the work scope under this ITER TA, designated as TA 81-18.

Brad J. Merrill

2008-02-01

300

Program Manager ITER CS Module Fabrication  

E-print Network

in Advanced Technology Systems For Defense and Energy Plastic Biodiesel Radar Systems and Imaging Hybrid Electric Drives Railgun Energy Storage Surveillance and Reconnaissance Power Conversion High Powered Lasers ­ Operating scenarios ­ minimum S/C coil requirements ­ Specific ITER requests ­ e.g., fusion performance

301

ITER plant layout and site services  

Microsoft Academic Search

The ITER site has not yet been determined. Nevertheless, to develop a construction plan and a cost estimate, it is necessary to have a detailed layout of the buildings, structures and outdoor equipment integrated with the balance of plant service systems prototypical of large fusion power plants. These services include electrical power for magnet feeds and plasma heating systems, cryogenic

V. A. Chuyanov

2000-01-01

302

Iterates of maps with symmetry  

NASA Technical Reports Server (NTRS)

Fixed-point bifurcation, period doubling, and Hopf bifurcation (HB) for iterates of equivariant mappings are investigated analytically, with a focus on HB in the presence of symmetry. An algebraic formulation for the hypotheses of the theorem of Ruelle (1973) is derived, and the case of standing waves in a system of ordinary differential equations with O(2) symmetry is considered in detail. In this case, it is shown that HB can lead directly to motion on an invariant 3-torus, with an unexpected third frequency due to drift of standing waves along the torus.

Chossat, Pascal; Golubitsky, Martin

1988-01-01

303

Power system Automatic Voltage Regulator design based on Static Output Feedback PID using iterative linear matrix inequality  

Microsoft Academic Search

This paper describes the design and simulation of a static output feedback (SOF) PID automatic voltage regulator (AVR) for a synchronous-machine infinite-bus power system. The design of the regulator guarantees the stability of the closed loop system and ensures the output voltage is maintained within an acceptable threshold. In addition, it damps out local-mode oscillations of the synchronous generator to

A. M. Abdel Ghany

2008-01-01

304

Lithium test module on ITER/TIBER  

SciTech Connect

ITER/TIBER (ITER) is the U.S. version of the design for the International Thermonuclear Experimental Reactor. The role of ITER is to test nuclear components for fusion power reactors. A major nuclear component to be tested is the breeder blanket and its associated tritium recovery system. To assist in the design of ITER, the engineering design of different blanket systems was done. This report summarizes a design of the tritium recovery system for a liquid lithium blanket, a prime candidate for a fusion power reactor. Objectives of this design were to ensure that a reliable, integrated performance of the tritium recovery system could be demonstrated and that the tritium could be measured. The latter objective permits one to validate the performance of the blanket module. For the tritium recovery system, the contractors and the electrolysis units were sized and costed. The magnetic force on the contactor was assessed. The tritium inventory for the system and the blanket module was calculated. Tritium recovery systems for larger blanket units could be designed using the information developed in this report.

Finn, P.A.

1988-09-01

305

ITER Fusion Energy  

SciTech Connect

ITER (in Latin “the way”) is designed to demonstrate the scientific and technological feasibility of fusion energy. Fusion is the process by which two light atomic nuclei combine to form a heavier over one and thus release energy. In the fusion process two isotopes of hydrogen – deuterium and tritium – fuse together to form a helium atom and a neutron. Thus fusion could provide large scale energy production without greenhouse effects; essentially limitless fuel would be available all over the world. The principal goals of ITER are to generate 500 megawatts of fusion power for periods of 300 to 500 seconds with a fusion power multiplication factor, Q, of at least 10. Q ? 10 (input power 50 MW / output power 500 MW). The ITER Organization was officially established in Cadarache, France, on 24 October 2007. The seven members engaged in the project – China, the European Union, India, Japan, Korea, Russia and the United States – represent more than half the world’s population. The costs for ITER are shared by the seven members. The cost for the construction will be approximately 5.5 billion Euros, a similar amount is foreseen for the twenty-year phase of operation and the subsequent decommissioning.

Dr. Norbert Holtkamp

2009-12-01

306

ITER Fusion Energy  

ScienceCinema

ITER (in Latin ?the way?) is designed to demonstrate the scientific and technological feasibility of fusion energy. Fusion is the process by which two light atomic nuclei combine to form a heavier over one and thus release energy. In the fusion process two isotopes of hydrogen ? deuterium and tritium ? fuse together to form a helium atom and a neutron. Thus fusion could provide large scale energy production without greenhouse effects; essentially limitless fuel would be available all over the world. The principal goals of ITER are to generate 500 megawatts of fusion power for periods of 300 to 500 seconds with a fusion power multiplication factor, Q, of at least 10. Q ? 10 (input power 50 MW / output power 500 MW). The ITER Organization was officially established in Cadarache, France, on 24 October 2007. The seven members engaged in the project ? China, the European Union, India, Japan, Korea, Russia and the United States ? represent more than half the world?s population. The costs for ITER are shared by the seven members. The cost for the construction will be approximately 5.5 billion Euros, a similar amount is foreseen for the twenty-year phase of operation and the subsequent decommissioning.

Dr. Norbert Holtkamp

2010-01-08

307

Analyses of static energy conversion systems for small nuclear power plants  

Microsoft Academic Search

Small, Gas Cooled Reactor (GCR) nuclear power plants with static energy conversion could meet the energy mix in underdeveloped countries, including electricity, residential and industrial space heating, seawater desalination, and\\/or high temperature process heat or steam for industrial uses. Analyses are performed of one high-temperature GCR and three intermediate-temperature GCR power plants with co-generation options to calculate and compare the

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

2003-01-01

308

Experimental demonstration of non-iterative interpolation-based partial ICI compensation in100G RGI-DP-CO-OFDM transport systems.  

PubMed

We experimentally investigate the performance of a low-complexity non-iterative phase noise induced inter-carrier interference (ICI) compensation algorithm in reduced-guard-interval dual-polarization coherent-optical orthogonal-frequency-division-multiplexing (RGI-DP-CO-OFDM) transport systems. This interpolation-based ICI compensator estimates the time-domain phase noise samples by a linear interpolation between the CPE estimates of the consecutive OFDM symbols. We experimentally study the performance of this scheme for a 28 Gbaud QPSK RGI-DP-CO-OFDM employing a low cost distributed feedback (DFB) laser. Experimental results using a DFB laser with the linewidth of 2.6 MHz demonstrate 24% and 13% improvement in transmission reach with respect to the conventional equalizer (CE) in presence of weak and strong dispersion-enhanced-phase-noise (DEPN), respectively. A brief analysis of the computational complexity of this scheme in terms of the number of required complex multiplications is provided. This practical approach does not suffer from error propagation while enjoying low computational complexity. PMID:22772177

Mousa-Pasandi, Mohammad E; Zhuge, Qunbi; Xu, Xian; Osman, Mohamed M; El-Sahn, Ziad A; Chagnon, Mathieu; Plant, David V

2012-07-01

309

How a submarine returns to periscope depth: analysing complex socio-technical systems using Cognitive Work Analysis.  

PubMed

This paper presents the application of Cognitive Work Analysis to the description of the functions, situations, activities, decisions, strategies, and competencies of a Trafalgar class submarine when performing the function of returning to periscope depth. All five phases of Cognitive Work Analysis are presented, namely: Work Domain Analysis, Control Task Analysis, Strategies Analysis, Social Organisation and Cooperation Analysis, and Worker Competencies Analysis. Complex socio-technical systems are difficult to analyse but Cognitive Work Analysis offers an integrated way of analysing complex systems with the core of functional means-ends analysis underlying all of the other representations. The joined-up analysis offers a coherent framework for understanding how socio-technical systems work. Data were collected through observation and interviews at different sites across the UK. The resultant representations present a statement of how the work domain and current activities are configured in this complex socio-technical system. This is intended to provide a baseline, from which all future conceptions of the domain may be compared. The strength of the analysis is in the multiple representations from which the constraints acting on the work may be analysed. Future research needs to challenge the assumptions behind these constraints in order to develop new ways of working. PMID:23702259

Stanton, Neville A; Bessell, Kevin

2014-01-01

310

Department of Energy ITER Project  

E-print Network

Department of Energy Assessment of the ITER Project Cost Estimate November 2002 #12;ii #12;i EXECUTIVE SUMMARY The Department of Energy (DOE) Assessment of the ITER Project Cost Estimate was conducted by the ITER Team, emphasizing reasonableness of project cost and schedule assumptions and, to the extent

311

White Paper for Developing Electromagnetic Particle Injector system for ITER on NSTX-U University of Washington (19 July 2012)  

E-print Network

to a conventional gas gun, but no technical flaws were identified. It was also suggested on demand - Conventional gas guns will inject gas before capsule and trigger pre. The proposed system, shown in Figures 1 and 2, is now under design. It has several

312

Fast Ion Collective Thomson Scattering Diagnostic for ITER  

E-print Network

Fast Ion Collective Thomson Scattering Diagnostic for ITER P.K. Michelsen, H. Bindslev, S. Korsholm of fast ions in ITER has been performed. The system is based on two high power probe beams the fast ion distribution from 100 keV to 3.5 MeV with a time resolution of 100 ms and a spatial resolution

313

POROSITY IN CONFORMAL INFINITE ITERATED FUNCTION MARIUSZ URBA '  

E-print Network

POROSITY IN CONFORMAL INFINITE ITERATED FUNCTION SYSTEMS MARIUSZ URBA ' NSKI Abstract. In this paper we deal with the problem of porosity of limit sets of conformal (infinite) iterated function, requirement also defines porosity. There exist positive constant c; Ÿ ? 0 such that each open ball B centered

Urbanski, Mariusz

314

Safety Analysis of ITER EDA Design by GEMSAFE  

Microsoft Academic Search

General Methodology of Safety Analysis and Evaluation for Fusion Systems (GEMSAFE) was applied to the International Thermonuclear Experimental Reactor (ITER) design in the stage of Engineering Design Activities (EDA) to identify Design Basis Events (DBEs) and the related safety features, which were compared with those of the ITER design in the stage of Conceptual Design Activities (CDA). As a result,

Mitsuhiro Arika; Masaki Saito; Tetsuo Sawada; Yoichi Fujii-e

1997-01-01

315

Sensitivity and uncertainty analyses applied to one-dimensional radionuclide transport in a layered fractured rock: MULTFRAC --Analytic solutions and local sensitivities; Phase 2, Iterative performance assessment: Volume 1  

SciTech Connect

Exact analytical solutions based on the Laplace transforms are derived for describing the one-dimensional space-time-dependent, advective transport of a decaying species in a layered, saturated rock system intersected by a planar fracture of varying aperture. These solutions, which account for advection in fracture, molecular diffusion into the rock matrix, adsorption in both fracture and matrix, and radioactive decay, predict the concentrations in both fracture and rock matrix and the cumulative mass in the fracture. The solute migration domain in both fracture and rock is assumed to be semi-infinite with non-zero initial conditions. The concentration of each nuclide at the source is allowed to decay either continuously or according to some periodical fluctuations where both are subjected to either a step or band release mode. Two numerical examples related to the transport of Np-237 and Cm-245 in a five-layered system of fractured rock were used to verify these solutions with several well established evaluation methods of Laplace inversion integrals in the real and complex domain. In addition, with respect to the model parameters, a comparison of the analytically derived local sensitivities for the concentration and cumulative mass of Np-237 in the fracture with the ones obtained through a finite-difference method of approximation is also reported.

Gureghian, A.B.; Wu, Y.T.; Sagar, B. [Southwest Research Inst., San Antonio, TX (United States). Center for Nuclear Waste Regulatory Analyses; Codell, R.A. [Nuclear Regulatory Commission, Washington, DC (United States)

1992-12-01

316

Analysing the capabilities and limitations of tracer tests in stream-aquifer systems  

USGS Publications Warehouse

The goal of this study was to identify the limitations that apply when we couple conservative-tracer injection with reactive solute sampling to identify the transport and reaction processes active in a stream. Our methodology applies Monte Carlo uncertainty analysis to assess the ability of the tracer approach to identify the governing transport and reaction processes for a wide range of stream-solute transport and reaction scenarios likely to be encountered in high-gradient streams. Our analyses identified dimensionless factors that define the capabilities and limitations of the tracer approach. These factors provide a framework for comparing and contrasting alternative tracer test designs.

Wagner, B.J.; Harvey, J.W.

2001-01-01

317

Challenges for Cryogenics at Iter  

NASA Astrophysics Data System (ADS)

Nuclear fusion of light nuclei is a promising option to provide clean, safe and cost competitive energy in the future. The ITER experimental reactor being designed by seven partners representing more than half of the world population will be assembled at Cadarache, South of France in the next decade. It is a thermonuclear fusion Tokamak that requires high magnetic fields to confine and stabilize the plasma. Cryogenic technology is extensively employed to achieve low-temperature conditions for the magnet and vacuum pumping systems. Efficient and reliable continuous operation shall be achieved despite unprecedented dynamic heat loads due to magnetic field variations and neutron production from the fusion reaction. Constraints and requirements of the largest superconducting Tokamak machine have been analyzed. Safety and technical risks have been initially assessed and proposals to mitigate the consequences analyzed. Industrial standards and components are being investigated to anticipate the requirements of reliable and efficient large scale energy production. After describing the basic features of ITER and its cryogenic system, we shall present the key design requirements, improvements, optimizations and challenges.

Serio, L.

2010-04-01

318

Global Asymptotic Behavior of Iterative Implicit Schemes  

NASA Technical Reports Server (NTRS)

The global asymptotic nonlinear behavior of some standard iterative procedures in solving nonlinear systems of algebraic equations arising from four implicit linear multistep methods (LMMs) in discretizing three models of 2 x 2 systems of first-order autonomous nonlinear ordinary differential equations (ODEs) is analyzed using the theory of dynamical systems. The iterative procedures include simple iteration and full and modified Newton iterations. The results are compared with standard Runge-Kutta explicit methods, a noniterative implicit procedure, and the Newton method of solving the steady part of the ODEs. Studies showed that aside from exhibiting spurious asymptotes, all of the four implicit LMMs can change the type and stability of the steady states of the differential equations (DEs). They also exhibit a drastic distortion but less shrinkage of the basin of attraction of the true solution than standard nonLMM explicit methods. The simple iteration procedure exhibits behavior which is similar to standard nonLMM explicit methods except that spurious steady-state numerical solutions cannot occur. The numerical basins of attraction of the noniterative implicit procedure mimic more closely the basins of attraction of the DEs and are more efficient than the three iterative implicit procedures for the four implicit LMMs. Contrary to popular belief, the initial data using the Newton method of solving the steady part of the DEs may not have to be close to the exact steady state for convergence. These results can be used as an explanation for possible causes and cures of slow convergence and nonconvergence of steady-state numerical solutions when using an implicit LMM time-dependent approach in computational fluid dynamics.

Yee, H. C.; Sweby, P. K.

1994-01-01

319

Insights into Hypoxic Systemic Responses Based on Analyses of Transcriptional Regulation in Arabidopsis  

PubMed Central

We have adopted a hypoxic treatment system in which only roots were under hypoxic conditions. Through analyzing global transcriptional changes in both shoots and roots, we found that systemic signals may be transduced from roots to trigger responses in tissues not directly subjected to hypoxia. The molecular mechanisms of such systemic responses under flooding are currently largely unknown. Using ontological categorization for regulated genes, a systemic managing program of carbohydrate metabolism was observed, providing an example of how systemic responses might facilitate the survival of plants under flooding. Moreover, a proportion of gene expressions that regulated in shoots by flooding was affected in an ethylene signaling mutation, ein2-5. Many systemic-responsive genes involved in the systemic carbohydrate managing program, hormone responses and metabolism, ubiquitin-dependent protein degradation were also affected in ein2-5. These results suggested an important role of ethylene in mediation of hypoxic systemic responses. Genes associated with abscisic acid (ABA) biosynthesis are upregulated in shoots and down regulated in roots. An ABA signaling mutation, abi4-1, affects expression of several systemic responsive genes. These results suggested that regulation of ABA biosynthesis could be required for systemic responses. The implications of these results for the systemic responses of root-flooded Arabidopsis are discussed. PMID:22194941

Hsu, Fu-Chiun; Chou, Mei-Yi; Peng, Hsiao-Ping; Chou, Shu-Jen; Shih, Ming-Che

2011-01-01

320

Development of the ITER baseline inductive scenario  

NASA Astrophysics Data System (ADS)

Sustainment of Q ˜ 10 operation with a fusion power of ˜500 MW for several hundred seconds is a key mission goal of the ITER Project. Past calculations and simulations predict that these conditions can be produced in high-confinement mode operation (H-mode) at 15 MA relying on only inductive current drive. Earlier development of 15 MA baseline inductive plasma scenarios provided a focal point for the ITER Design Review conducted in 2007-2008. In the intervening period, detailed predictive simulations, supported by experimental demonstrations in existing tokamaks, allow us to assemble an end-to-end specification of this scenario consistent with the final design of the ITER device. Simulations have encompassed plasma initiation, current ramp-up, plasma burn and current ramp-down, and have included density profiles and thermal transport models producing temperature profiles consistent with edge pedestal conditions present in current fusion experiments. These quasi-stationary conditions are maintained due to the presence of edge-localized modes that limit the edge pressure. High temperatures and densities in the pedestal region produce significant edge bootstrap current that must be considered in modelling of feedback control of shape and vertical stability. In this paper we present new results of transport simulations fully consistent with the final ITER design that remain within allowed limits for the coil system and power supplies. These self-consistent simulations increase our confidence in meeting the challenges of the ITER program.

Casper, T.; Gribov, Y.; Kavin, A.; Lukash, V.; Khayrutdinov, R.; Fujieda, H.; Kessel, C.; pre="for the"> ITER Organization,

2014-01-01

321

A dual-source low-energy mass-analysed ion beam system for semiconductor epitaxy and novel materials growth  

NASA Astrophysics Data System (ADS)

A dual-source mass-analysed low-energy ion beam system, intended for investigations into novel materials deposition and epitaxial layer growth, is described. The investigations require that uniform ion beams of useful flux and area, with an energy range reaching below damage thresholds, can be delivered into an ultrahigh vacuum target environment. The system described has been designed to provide 100 ?A cm -2 beams of a wide range of species, fast switching between different species, and energies down to 10 eV and below.

Gordon, J. S.; Armour, D. G.; Donnelly, S. E.; van den Berg, J. A.; Marton, D.; Rabalais, J. W.

1991-07-01

322

Optimization-Based Constrained Iterative Learning Control  

Microsoft Academic Search

We consider the problem of synthesis of iterative learning control (ILC) schemes for constrained linear systems executing a repetitive task. The ILC problem with affine constraints and quadratic objective functions is formulated as a convex quadratic program, for which there exist computationally efficient solvers. The key difference between standard convex optimization and the corresponding constrained ILC problem is that each

Sandipan Mishra; Ufuk Topcu; Masayoshi Tomizuka

2011-01-01

323

Symmetric iterative interpolation processes  

Microsoft Academic Search

Using a baseb and an even number of knots, we define a symmetric iterative interpolation process. The main properties of this process come from an associated functionF. The basic functional equation forF is thatF(t\\/b)=snF(n\\/b)F(t-n). We prove thatF is a continuous positive definite function. We find almost precisely in which Lipschitz classes derivatives ofF belong. If a functiony is defined only

Gilles Deslauriers; Serge Dubuc

1989-01-01

324

SCALE: A modular code system for performing standardized computer analyses for licensing evaluation: Functional modules, F9-F11  

SciTech Connect

This Manual represents Revision 5 of the user documentation for the modular code system referred to as SCALE. The history of the SCALE code system dates back to 1969 when the current Computational Physics and Engineering Division at Oak Ridge National Laboratory (ORNL) began providing the transportation package certification staff at the U.S. Atomic Energy Commission with computational support in the use of the new KENO code for performing criticality safety assessments with the statistical Monte Carlo method. From 1969 to 1976 the certification staff relied on the ORNL staff to assist them in the correct use of codes and data for criticality, shielding, and heat transfer analyses of transportation packages. However, the certification staff learned that, with only occasional use of the codes, it was difficult to become proficient in performing the calculations often needed for an independent safety review. Thus, shortly after the move of the certification staff to the U.S. Nuclear Regulatory Commission (NRC), the NRC staff proposed the development of an easy-to-use analysis system that provided the technical capabilities of the individual modules with which they were familiar. With this proposal, the concept of the Standardized Computer Analyses for Licensing Evaluation (SCALE) code system was born. This volume consists of the section of the manual dealing with three of the functional modules in the code. Those are the Morse-SGC for the SCALE system, Heating 7.2, and KENO V.a. The manual describes the latest released versions of the codes.

NONE

1997-03-01

325

System assessment study of the ESA Darwin Mission: concepts trade-off and first iteration design on novel Emma arrangement  

NASA Astrophysics Data System (ADS)

ESA's Darwin mission is devoted to direct detection and spectroscopic characterisation of Earth-like planets in the thermal infrared domain by nulling interferometry in space. This technique requires deep and stable starlight rejection to an efficiency around 106 over the whole spectral band. Darwin is a major target for Thales Alenia Space, and is considered as a strategic part of its programme roadmap. In this paper we present the main outcomes of the Darwin mission study conducted by Thales Alenia Space from Oct. 2005 to Jul. 2007. Studying this mission in depth, our proposed most promising configuration features spacecraft in non planar arrangement (called Emma). It offers the best science return in terms of number of stars detected and sky accessibility while staying compliant with mass and volume constraints of a single Ariane 5 launch. Our solution dramatically alleviates engineering constraints thanks to a fully non deployable concept. As compared to the more conventional planar arrangement (called Charles), Emma suppresses Single Point Failures and spurious flexible modes, thus maximising both the system reliability and the stability of the dynamical environment. Emma is fully compatible with either 3 or 4 collectors.

Ruilier, C.; Krawczyk, R.; Sghedoni, M.; Chanal, O.; Degrelle, C.; Pirson, L.; Simane, O.; Thomas, E.

2007-09-01

326

Three-dimensional imaging system for analyses of dynamic droplet impaction and deposition formation on leaves  

Technology Transfer Automated Retrieval System (TEKTRAN)

A system was developed to assess the dynamic processes of droplet impact, rebound and retention on leaf surfaces with three-dimensional (3-D) images. The system components consisted of a uniform-size droplet generator, two high speed digital video cameras, a constant speed track, a leaf holder, and ...

327

Systems Performance Analyses of Alaska Wind-Diesel Projects; St. Paul, Alaska (Fact Sheet)  

SciTech Connect

This fact sheet summarizes a systems performance analysis of the wind-diesel project in St. Paul, Alaska. Data provided for this project include load data, average wind turbine output, average diesel plant output, dump (controlling) load, average net capacity factor, average net wind penetration, estimated fuel savings, and wind system availability.

Baring-Gould, I.

2009-04-01

328

Set Theory Applied to Uniquely Define the Inputs to Territorial Systems in Emergy Analyses  

EPA Science Inventory

The language of set theory can be utilized to represent the emergy involved in all processes. In this paper we use set theory in an emergy evaluation to ensure an accurate representation of the inputs to territorial systems. We consider a generic territorial system and we describ...

329

Energy efficiency analyses of active flow aftertreatment systems for lean burn internal combustion engines  

Microsoft Academic Search

The use of three way catalytic converters in stoichiometric burn reciprocating internal combustion engine systems has proved to be an effective and efficient method for reducing the level of criteria pollutants. However, such passive systems have not been as successful in emission amelioration when combined with lean burn engines. This is because of the thermochemical nature of the exhaust gases

Ming Zheng; Graham T. Reader

2004-01-01

330

Analysis of loss-of-coolant and loss-of-flow accidents in the first wall cooling system of NET/ITER  

NASA Astrophysics Data System (ADS)

This paper presents the thermal-hydraulic analysis of potential accidents in the first wall cooling system of the Next European Torus or the International Thermonuclear Experimental Reactor. Three ex-vessel loss-of-coolant accidents, two in-vessel loss-of-coolant accidents, and three loss-of-flow accidents have been analyzed using the thermal-hydraulic system analysis code RELAP5/MOD3. The analyses deal with the transient thermal-hydraulic behavior inside the cooling systems and the temperature development inside the nuclear components during these accidents. The analysis of the different accident scenarios has been performed without operation of emergency cooling systems. The results of the analyses indicate that a loss of forced coolant flow through the first wall rapidly causes dryout in the first wall cooling pipes. Following dryout, melting in the first wall starts within about 130 s in case of ongoing plasma burning. In case of large break LOCAs and ongoing plasma burning, melting in the first wall starts about 90 s after accident initiation.

Komen, E. M. J.; Koning, H.

1994-03-01

331

Challenges and status of ITER conductor production  

NASA Astrophysics Data System (ADS)

Taking the relay of the large Hadron collider (LHC) at CERN, ITER has become the largest project in applied superconductivity. In addition to its technical complexity, ITER is also a management challenge as it relies on an unprecedented collaboration of seven partners, representing more than half of the world population, who provide 90% of the components as in-kind contributions. The ITER magnet system is one of the most sophisticated superconducting magnet systems ever designed, with an enormous stored energy of 51 GJ. It involves six of the ITER partners. The coils are wound from cable-in-conduit conductors (CICCs) made up of superconducting and copper strands assembled into a multistage cable, inserted into a conduit of butt-welded austenitic steel tubes. The conductors for the toroidal field (TF) and central solenoid (CS) coils require about 600 t of Nb3Sn strands while the poloidal field (PF) and correction coil (CC) and busbar conductors need around 275 t of Nb-Ti strands. The required amount of Nb3Sn strands far exceeds pre-existing industrial capacity and has called for a significant worldwide production scale up. The TF conductors are the first ITER components to be mass produced and are more than 50% complete. During its life time, the CS coil will have to sustain several tens of thousands of electromagnetic (EM) cycles to high current and field conditions, way beyond anything a large Nb3Sn coil has ever experienced. Following a comprehensive R&D program, a technical solution has been found for the CS conductor, which ensures stable performance versus EM and thermal cycling. Productions of PF, CC and busbar conductors are also underway. After an introduction to the ITER project and magnet system, we describe the ITER conductor procurements and the quality assurance/quality control programs that have been implemented to ensure production uniformity across numerous suppliers. Then, we provide examples of technical challenges that have been encountered and we present the status of ITER conductor production worldwide.

Devred, A.; Backbier, I.; Bessette, D.; Bevillard, G.; Gardner, M.; Jong, C.; Lillaz, F.; Mitchell, N.; Romano, G.; Vostner, A.

2014-04-01

332

Analyses of geometrically nonlinear structures using a Langrangian strain representation and a convected coordinate system  

E-print Network

the updated coordinate system x-y' is the reference system, all the c and q terms drop out. Therefore, Eq. 32 is reduced to 66c = ? )??4? (66q , 66q ) L?1' -y/L $2, $'3 $5 4Q (66 2, 66q3, 66q5, 66q6 + ( &??&?(6q ?dq?( ~??&?(6&q ?66q? 1 L ?2' 3' 5'4Q 2... cF (n+II tb lead stop FIG. 1 ? Coercgctcds Systems in Canwalwl Coetdinctte Fscmttltstlon for the (n + 1)th load step; the quotation marks are quite significant since the "undeformed" coordinates, b , may be considerably different from...

Cheung, Shing Tak

1974-01-01

333

Results of thin-route satellite communication system analyses including estimated service costs  

NASA Technical Reports Server (NTRS)

Ways for determining optimum satellite and terrestrial system architectures and parameters for providing the most economical telephone service to remote areas of the U.S. are explored. Several configurations for an isolated rural telephone system, covering all the states plus Alaska, employing satellites is considered. Both direct-to-the-user and community-type of systems are evaluated using UHF and Ku-band RF equipment for the rural/satellite links. The effect of multiple spot beams, outage, signal quality, modulation method, satellite accessing, forward error correction, and the number of users are also evaluated. The total cost for a 5-minute call from an isolated rural user to a TELCO user was shown to be as low as $1.30 for a system with 1.8 X 10 to the sixth rural users.

Wright, D. L.

1979-01-01

334

Comparative analyses of amplicon migration behavior in differing denaturing gradient gel electrophoresis (DGGE) systems  

Microsoft Academic Search

Denaturing gradient gel electrophoresis (DGGE) is commonly utilized to identify and quantify microbial diversity, but the\\u000a conditions required for different electrophoretic systems to yield equivalent results and optimal resolution have not been\\u000a assessed. Herein, the influence of different DGGE system configuration parameters on microbial diversity estimates was tested\\u000a using Symbiodinium, a group of marine eukaryotic microbes that are important constituents

D. J. Thornhill; D. W. Kemp; E. M. Sampayo; G. W. Schmidt

2010-01-01

335

Applying I-FGM to image retrieval and an I-FGM system performance analyses  

NASA Astrophysics Data System (ADS)

Intelligent Foraging, Gathering and Matching (I-FGM) combines a unique multi-agent architecture with a novel partial processing paradigm to provide a solution for real-time information retrieval in large and dynamic databases. I-FGM provides a unified framework for combining the results from various heterogeneous databases and seeks to provide easily verifiable performance guarantees. In our previous work, I-FGM had been implemented and validated with experiments on dynamic text data. However, the heterogeneity of search spaces requires our system having the ability to effectively handle various types of data. Besides texts, images are the most significant and fundamental data for information retrieval. In this paper, we extend the I-FGM system to incorporate images in its search spaces using a region-based Wavelet Image Retrieval algorithm called WALRUS. Similar to what we did for text retrieval, we modified the WALRUS algorithm to partially and incrementally extract the regions from an image and measure the similarity value of this image. Based on the obtained partial results, we refine our computational resources by updating the priority values of image documents. Experiments have been conducted on I-FGM system with image retrieval. The results show that I-FGM outperforms its control systems. Also, in this paper we present theoretical analysis of the systems with a focus on performance. Based on probability theory, we provide models and predictions of the average performance of the I-FGM system and its two control systems, as well as the systems without partial processing.

Santos, Eugene, Jr.; Santos, Eunice E.; Nguyen, Hien; Pan, Long; Korah, John; Zhao, Qunhua; Xia, Huadong

2007-04-01

336

SCALE: A modular code system for performing standardized computer analyses for licensing evaluation: Control modules C4, C6  

SciTech Connect

This Manual represents Revision 5 of the user documentation for the modular code system referred to as SCALE. The history of the SCALE code system dates back to 1969 when the current Computational Physics and Engineering Division at Oak Ridge National Laboratory (ORNL) began providing the transportation package certification staff at the U. S. Atomic Energy Commission with computational support in the use of the new KENO code for performing criticality safety assessments with the statistical Monte Carlo method. From 1969 to 1976 the certification staff relied on the ORNL staff to assist them in the correct use of codes and data for criticality, shielding, and heat transfer analyses of transportation packages. However, the certification staff learned that, with only occasional use of the codes, it was difficult to become proficient in performing the calculations often needed for an independent safety review. Thus, shortly after the move of the certification staff to the U.S. Nuclear Regulatory Commission (NRC), the NRC staff proposed the development of an easy-to-use analysis system that provided the technical capabilities of the individual modules with which they were familiar. With this proposal, the concept of the Standardized Computer Analyses for Licensing Evaluation (SCALE) code system was born. This volume is part of the manual related to the control modules for the newest updated version of this computational package.

NONE

1997-03-01

337

Novel Hybrid Monte Carlo/Deterministic Technique for Shutdown Dose Rate Analyses of Fusion Energy Systems  

SciTech Connect

The rigorous 2-step (R2S) method uses three-dimensional Monte Carlo transport simulations to calculate the shutdown dose rate (SDDR) in fusion reactors. Accurate full-scale R2S calculations are impractical in fusion reactors because they require calculating space- and energy-dependent neutron fluxes everywhere inside the reactor. The use of global Monte Carlo variance reduction techniques was suggested for accelerating the neutron transport calculation of the R2S method. The prohibitive computational costs of these approaches, which increase with the problem size and amount of shielding materials, inhibit their use in the accurate full-scale neutronics analyses of fusion reactors. This paper describes a novel hybrid Monte Carlo/deterministic technique that uses the Consistent Adjoint Driven Importance Sampling (CADIS) methodology but focuses on multi-step shielding calculations. The Multi-Step CADIS (MS-CADIS) method speeds up the Monte Carlo neutron calculation of the R2S method using an importance function that represents the importance of the neutrons to the final SDDR. Using a simplified example, preliminarily results showed that the use of MS-CADIS enhanced the efficiency of the neutron Monte Carlo simulation of an SDDR calculation by a factor of 550 compared to standard global variance reduction techniques, and that the increase over analog Monte Carlo is higher than 10,000.

Ibrahim, Ahmad M [ORNL] [ORNL; Peplow, Douglas E. [ORNL] [ORNL; Peterson, Joshua L [ORNL] [ORNL; Grove, Robert E [ORNL] [ORNL

2013-01-01

338

Systems-Based Analyses of Brain Regions Functionally Impacted in Parkinson's Disease Reveals Underlying Causal Mechanisms  

PubMed Central

Detailed analysis of disease-affected tissue provides insight into molecular mechanisms contributing to pathogenesis. Substantia nigra, striatum, and cortex are functionally connected with increasing degrees of alpha-synuclein pathology in Parkinson's disease. We undertook functional and causal pathway analysis of gene expression and proteomic alterations in these three regions, and the data revealed pathways that correlated with disease progression. In addition, microarray and RNAseq experiments revealed previously unidentified causal changes related to oligodendrocyte function and synaptic vesicle release, and these and other changes were reflected across all brain regions. Importantly, subsets of these changes were replicated in Parkinson's disease blood; suggesting peripheral tissue may provide important avenues for understanding and measuring disease status and progression. Proteomic assessment revealed alterations in mitochondria and vesicular transport proteins that preceded gene expression changes indicating defects in translation and/or protein turnover. Our combined approach of proteomics, RNAseq and microarray analyses provides a comprehensive view of the molecular changes that accompany functional loss and alpha-synuclein pathology in Parkinson's disease, and may be instrumental to understand, diagnose and follow Parkinson's disease progression. PMID:25170892

Emig-Agius, Dorothea; Bessarabova, Marina; Ivliev, Alexander E.; Schüle, Birgit; Alexander, Jeff; Wallace, William; Halliday, Glenda M.; Langston, J. William; Braxton, Scott; Yednock, Ted; Shaler, Thomas; Johnston, Jennifer A.

2014-01-01

339

Ultra-Structure database design methodology for managing systems biology data and analyses  

PubMed Central

Background Modern, high-throughput biological experiments generate copious, heterogeneous, interconnected data sets. Research is dynamic, with frequently changing protocols, techniques, instruments, and file formats. Because of these factors, systems designed to manage and integrate modern biological data sets often end up as large, unwieldy databases that become difficult to maintain or evolve. The novel rule-based approach of the Ultra-Structure design methodology presents a potential solution to this problem. By representing both data and processes as formal rules within a database, an Ultra-Structure system constitutes a flexible framework that enables users to explicitly store domain knowledge in both a machine- and human-readable form. End users themselves can change the system's capabilities without programmer intervention, simply by altering database contents; no computer code or schemas need be modified. This provides flexibility in adapting to change, and allows integration of disparate, heterogenous data sets within a small core set of database tables, facilitating joint analysis and visualization without becoming unwieldy. Here, we examine the application of Ultra-Structure to our ongoing research program for the integration of large proteomic and genomic data sets (proteogenomic mapping). Results We transitioned our proteogenomic mapping information system from a traditional entity-relationship design to one based on Ultra-Structure. Our system integrates tandem mass spectrum data, genomic annotation sets, and spectrum/peptide mappings, all within a small, general framework implemented within a standard relational database system. General software procedures driven by user-modifiable rules can perform tasks such as logical deduction and location-based computations. The system is not tied specifically to proteogenomic research, but is rather designed to accommodate virtually any kind of biological research. Conclusion We find Ultra-Structure offers substantial benefits for biological information systems, the largest being the integration of diverse information sources into a common framework. This facilitates systems biology research by integrating data from disparate high-throughput techniques. It also enables us to readily incorporate new data types, sources, and domain knowledge with no change to the database structure or associated computer code. Ultra-Structure may be a significant step towards solving the hard problem of data management and integration in the systems biology era. PMID:19691849

Maier, Christopher W; Long, Jeffrey G; Hemminger, Bradley M; Giddings, Morgan C

2009-01-01

340

Numerical and experimental analyses of the radiant heat flux produced by quartz heating systems  

NASA Technical Reports Server (NTRS)

A method is developed for predicting the radiant heat flux distribution produced by tungsten filament, tubular fused-quartz envelope heating systems with reflectors. The method is an application of Monte Carlo simulation, which takes the form of a random walk or ray tracing scheme. The method is applied to four systems of increasing complexity, including a single lamp without a reflector, a single lamp with a Hat reflector, a single lamp with a parabolic reflector, and up to six lamps in a six-lamp contoured-reflector heating unit. The application of the Monte Carlo method to the simulation of the thermal radiation generated by these systems is discussed. The procedures for numerical implementation are also presented. Experiments were conducted to study these quartz heating systems and to acquire measurements of the corresponding empirical heat flux distributions for correlation with analysis. The experiments were conducted such that several complicating factors could be isolated and studied sequentially. Comparisons of the experimental results with analysis are presented and discussed. Good agreement between the experimental and simulated results was obtained in all cases. This study shows that this method can be used to analyze very complicated quartz heating systems and can account for factors such as spectral properties, specular reflection from curved surfaces, source enhancement due to reflectors and/or adjacent sources, and interaction with a participating medium in a straightforward manner.

Turner, Travis L.; Ash, Robert L.

1994-01-01

341

Non-target screening analyses of organic contaminants in river systems as a base for monitoring measures  

NASA Astrophysics Data System (ADS)

Organic contaminants discharged to the aquatic environment exhibit a high diversity with respect to their molecular structures and the resulting physico-chemical properties. The chemical analysis of anthropogenic contamination in river systems is still an important feature, especially with respect to (i) the identification and structure elucidation of novel contaminants, (ii) to the characterisation of their environmental behaviour and (iii) to their risk for natural systems. A huge proportion of riverine contamination is caused by low-molecular weight organic compounds, like pesticides plasticizers, pharmaceuticals, personal care products, technical additives etc. Some of them, like PCB or PAH have already been investigated thoroughly and, consequently, their behaviour in aqueous systems is very well described. Although analyses on organic substances in river water traditionally focused on selected pollutants, in particular on common priority pollutants which are monitored routinely, the occurrence of further contaminants, e.g. pharmaceuticals, personal care products or chelating agents has received increasing attention within the last decade. Accompanied, screening analyses revealing an enormous diversity of low-molecular weight organic contaminants in waste water effluents and river water become more and more noticed. Since many of these substances have been rarely noticed so far, it will be an important task for the future to study their occurrence and fate in natural environments. Further on, it should be a main issue of environmental studies to provide a comprehensive view on the state of pollution of river water, in particular with respect to lipophilic low molecular weight organic contaminants. However, such non-target-screening analyses has been performed only rarely in the past. Hence, we applied extended non-target screening analyses on longitudinal sections of the rivers Rhine, Rur and Lippe (Germany) on the base of GC/MS analyses. The investigations revealed complex pattern of anthropogenic contaminants comprising a lot of still unnoticed pollutants (e.g. specific sulfones, trifluoromethyl substituted substances, nitrogen heterocycles etc.) or still unidentified compounds (such as selected brominated aromatics) of obviously high environmental relevance. In this presentation, a selection of several different contaminants will be discussed in detail comprising their emission sources, their emission behaviour, their fate within the river water bodies and in particular their structural properties. Generally. this investigation demonstrated the need to expand our analytical focus on a broader spectrum of organic contaminants, in particular to build up an adapted base for advanced monitoring studies.

Schwarzbauer, J.

2009-04-01

342

Development of Algorithms and Error Analyses for the Short Baseline Lightning Detection and Ranging System  

NASA Technical Reports Server (NTRS)

NASA, at the John F. Kennedy Space Center (KSC), developed and operates a unique high-precision lightning location system to provide lightning-related weather warnings. These warnings are used to stop lightning- sensitive operations such as space vehicle launches and ground operations where equipment and personnel are at risk. The data is provided to the Range Weather Operations (45th Weather Squadron, U.S. Air Force) where it is used with other meteorological data to issue weather advisories and warnings for Cape Canaveral Air Station and KSC operations. This system, called Lightning Detection and Ranging (LDAR), provides users with a graphical display in three dimensions of 66 megahertz radio frequency events generated by lightning processes. The locations of these events provide a sound basis for the prediction of lightning hazards. This document provides the basis for the design approach and data analysis for a system of radio frequency receivers to provide azimuth and elevation data for lightning pulses detected simultaneously by the LDAR system. The intent is for this direction-finding system to correct and augment the data provided by LDAR and, thereby, increase the rate of valid data and to correct or discard any invalid data. This document develops the necessary equations and algorithms, identifies sources of systematic errors and means to correct them, and analyzes the algorithms for random error. This data analysis approach is not found in the existing literature and was developed to facilitate the operation of this Short Baseline LDAR (SBLDAR). These algorithms may also be useful for other direction-finding systems using radio pulses or ultrasonic pulse data.

Starr, Stanley O.

1998-01-01

343

Dielectrophoresis-Raman spectroscopy system for analysing suspended WO3 nanoparticles  

NASA Astrophysics Data System (ADS)

Dielectrophoresis (DEP) utilizing a curved microelectrode pattern was developed and integrated with a Raman spectroscopy system. The electrodes were patterned on a Raman transparent quartz substrate, and integrated with a microfluidic channel in poly-dimethylsiloxane (PDMS). This integrated system can be efficiently used for the determination of suspended particles type and the direct mapping of their spatial concentrations. It will be demonstrated that the integration of Raman mapping with dielectrophoretically controlled WO3 particles can be used for studying suspended particles in situ.

Chrimes, Adam F.; Kayani, Aminuddin; Khoshmanesh, Khashayar; Kalantar-zadeh, Kourosh

2011-06-01

344

Parent Stars of Extrasolar Planets VI: Abundance Analyses of 20 New Systems  

E-print Network

The results of new spectroscopic analyses of 20 recently reported extrasolar planet parent stars are presented. The companion of one of these stars, HD 10697, has recently been shown to have a mass in the brown dwarf regime; we find [Fe/H] $= +0.16$ for it. For the remaining sample, we derive [Fe/H] estimates ranging from -0.41 to $+0.37$, with an average value of $+0.18 \\pm 0.19$. If we add the 13 stars included in the previous papers of this series and 6 other stars with companions below the 11 M$_{\\rm Jup}$ limit from the recent studies of Santos et al., we derive $ = +0.17 \\pm 0.20$. Among the youngest stars with planets with F or G0 spectral types, [Fe/H] is systematically larger than young field stars of the same Galactocentric distance by 0.15 to 0.20 dex. This confirms the recent finding of Laughlin that the most massive stars with planets are systematically more metal rich than field stars of the same mass. We interpret these trends as supporting a scenario in which these stars accreted high-Z material after their convective envelopes shrunk to near their present masses. Correcting these young star metallicities by 0.15 dex still does not fully account for the difference in mean metallicity between the field stars and the full parent stars sample. The stars with planets appear to have smaller [Na/Fe], [Mg/Fe], and [Al/Fe] values than field dwarfs of the same [Fe/H]. They do not appear to have significantly different values of [O/Fe], [Si/Fe], [Ca/Fe], or [Ti/Fe], though.

G. Gonzalez; C. Laws; S. Tyagi; B. E. Reddy

2000-10-10

345

Assessment of plasma parameters for the low activation phase of ITER operation  

NASA Astrophysics Data System (ADS)

An assessment of ITER plasma parameters is carried out for the low activation phase that is required for commissioning the basic ITER systems including plasma control, heating and current drive. Such an operation is analysed for hydrogen, helium and deuterium plasmas for full field and current, as well as with magnetic field and plasma current reduced to half of their design values, B0 = 2.65 T, Ip = 7.5 MA. Both hydrogen and deuterium neutral beam injection (NBI) are considered. We assess the possible domain for safe operation, and the possible target plasmas for commissioning the NBI, electron cyclotron heating (ECH) and ion cyclotron heating (ICH) systems, taking into account the constraints imposed by NB shine-through loss, Greenwald limit and access to H-mode operation. Simulations with the Automated System for Transport Analysis (ASTRA) show that for 33 MW of NBI with 20 MW of ECH, H-mode access is marginal for hydrogen plasmas. Good H-mode confinement, expected at PNB + PEC + PIC > 1.5 PL-H, is more likely for the helium and deuterium cases. It is found that plasma parameters, such as normalized beta, plasma density and current flat-top duration, for full power/half field/half current operation can be similar to those required for the DT long pulse operation. Preliminary assessment is also made of the maximum of tritium and neutron yield achievable in a single shot at the deuterium phase of ITER operation.

Polevoi, A. R.; Campbell, D. J.; Chuyanov, V. A.; Houlberg, W.; Ivanov, A. A.; Kukushkin, A. S.; Lamalle, P.; Loarte, A.; Mukhovatov, V. S.; Oikawa, T.

2013-12-01

346

Parent Ratings of Children's Social Skills: Longitudinal Psychometric Analyses of the Social Skills Rating System  

ERIC Educational Resources Information Center

The assessment of children's social skills is an important task for school psychologists in both applied and research settings. The present study examines the psychometric properties of parent ratings of the Social Skills Rating System (SSRS), in kindergarten through third grades, testing for measurement differences between boys and girls, between…

Van Horn, M. Lee; Atkins-Burnett, Sally; Karlin, Emilie; Ramey, Sharon Landesman; Snyder, Scott

2007-01-01

347

An Earthquake Prediction System Using The Time Series Analyses of Earthquake Property And Crust Motion  

NASA Astrophysics Data System (ADS)

We have developed a short-term deterministic earthquake (EQ) forecasting system similar to those used for Typhoons and Hurricanes, which has been under a test operation at website http://www.tec21.jp/ since June of 2003. We use the focus and crust displacement data recently opened to the public by Japanese seismograph and global positioning system (GPS) networks, respectively. Our system divides the forecasting area into the five regional areas of Japan, each of which is about 5° by 5°. We have found that it can forecast the focus, date of occurrence and magnitude (M) of an impending EQ (whose M is larger than about 6), all within narrow limits. We have two examples to describe the system. One is the 2003/09/26 EQ of M 8 in the Hokkaido area, which is of hindsight. Another is a successful rollout of the most recent forecast on the 2004/05/30 EQ of M 6.7 off coast of the southern Kanto (Tokyo) area.

Takeda, Fumihide; Takeo, Makoto

2004-12-01

348

Epithelial monolayer culture system for real?time single?cell analyses  

PubMed Central

Abstract Many epithelial cells form polarized monolayers under in vivo and in vitro conditions. Typically, epithelial cells are cultured for differentiation on insert systems where cells are plated on a porous filter membrane. Although the cultured monolayers have been a standard system to study epithelial physiology, there are some limits: The epithelial cells growing inside the commercial inserts are not optimal to visualize directly through lenses on inverted microscopes. The cell images are optically distorted and background fluorescence is bright due to the filter membrane positioned between the cells and the lens. In addition, the cells are not easily accessible by electrodes due to the presence of tall side walls. Here, we present the design, fabrication, and practical applications of an improved system for analysis of polarized epithelial monolayers. This new system allows (1) direct imaging of cells without an interfering filter membrane, (2) electrophysiological measurements, and (3) detection of apical secretion with minimal dilution. Therefore, our culture method is optimized to study differentiated epithelial cells at the single?cell and subcellular levels, and can be extended to other cell types with minor modifications. PMID:24771696

Seo, Jong Bae; Moody, Mark; Koh, Duk?Su

2014-01-01

349

Using ITU-R 370 Method to Analyse Spread (Propagation) Conditions in Land Mobile Systems  

Microsoft Academic Search

Summary form only given. The main property characterizing of all telecommunications systems is its utilization for electromagnetic space. This space is defined as component of the following elements: electromagnetic spectrum, physical space and time. In deed each microwave instrument presents a point in electromagnetic space, while it's taken in consideration operating frequency, its coordinates and operating time. Interference of two

A. A. Rasim; W. A. Al Moktar

2006-01-01

350

An Earthquake Prediction System Using The Time Series Analyses of Earthquake Property And Crust Motion  

SciTech Connect

We have developed a short-term deterministic earthquake (EQ) forecasting system similar to those used for Typhoons and Hurricanes, which has been under a test operation at website http://www.tec21.jp/ since June of 2003. We use the focus and crust displacement data recently opened to the public by Japanese seismograph and global positioning system (GPS) networks, respectively. Our system divides the forecasting area into the five regional areas of Japan, each of which is about 5 deg. by 5 deg. We have found that it can forecast the focus, date of occurrence and magnitude (M) of an impending EQ (whose M is larger than about 6), all within narrow limits. We have two examples to describe the system. One is the 2003/09/26 EQ of M 8 in the Hokkaido area, which is of hindsight. Another is a successful rollout of the most recent forecast on the 2004/05/30 EQ of M 6.7 off coast of the southern Kanto (Tokyo) area.

Takeda, Fumihide [Takeda Engineering Consultant Inc., 2-14-23 Ujina Miyuki, Hiroshima, 734-0015 (Japan); Takeo, Makoto [Department of Physics, Portland State University, P.O. Box 751, Portland, OR, 97207-0751 (United States)

2004-12-09

351

Solar power satellite. System definition study. Part 1, volume 3: Construction, transportation and cost analyses  

NASA Technical Reports Server (NTRS)

Concepts developed for both LEO and GEO construction of photovoltaic and thermal engine satellites are analyzed. Topics discussed include: satellite construction; crew scheduling; crew jobs and organizations; operator productivity rating; constructability rating; transportation systems for cargo launch, refueling operations, personnel transport, and orbit transfer; collision analysis, cost analysis, and radiation evironment and effects.

1977-01-01

352

Factoring the Personal Profile System for Construct Validity: Three Analyses under Different Standardization Assumptions.  

ERIC Educational Resources Information Center

Three types of data were factor analyzed using principal components extractions with orthogonal and oblique rotations to test publisher claims for construct validity of the Personal Profile System (PPS). Behavioral descriptor data from 1,045 senior non-commissioned Air Force officers were factored as raw data, mean corrected data, and standardized…

Henkel, Thomas George; Wilmoth, James Noel

353

Reviewing optimisation criteria for energy systems analyses of renewable energy integration  

Microsoft Academic Search

The utilisation of fluctuating renewable energy sources is increasing world-wide; however, so is the concern about how to integrate these resources into the energy systems. The design of optimal energy resource mixes in climate change mitigation actions is a challenge faced in many places. This optimisation may be implemented according to economic objectives or with a focus on techno-operational aims

Poul Alberg Østergaard

2009-01-01

354

A New Student Performance Analysing System Using Knowledge Discovery in Higher Educational Databases  

ERIC Educational Resources Information Center

Knowledge discovery is a wide ranged process including data mining, which is used to find out meaningful and useful patterns in large amounts of data. In order to explore the factors having impact on the success of university students, knowledge discovery software, called MUSKUP, has been developed and tested on student data. In this system a…

Guruler, Huseyin; Istanbullu, Ayhan; Karahasan, Mehmet

2010-01-01

355

CFD Analyses of a Notebook Computer Thermal Management System and a Proposed Passive Cooling Alternative  

Microsoft Academic Search

A notebook computer thermal management system is analyzed using a commercial computational fluid dynamics software package (ANSYS Fluent). The active and passive paths that are used for heat dissipation are examined for different steady state operating conditions. For each case, average and hot-spot temperatures of the components are compared with the maximum allowable operating temperatures. It is observed that when

Ilker Tari; Fidan Seza Yalcin

2010-01-01

356

Material and design considerations for the carbon armored ITER divertor  

NASA Astrophysics Data System (ADS)

The properties of materials for the carbon armored ITER divertor were evaluated from literature and manufacturers' documentation. Most of these data, however, have been not known or not published yet. We have evaluated an optimum data set of the candidate materials of the ITER divertor, which were needed for finite element analyses (FEM). The materials evaluated are as follows; MFC-1, CX2002U, SEP-N112, P-130, IG-430U for the carbon based materials, and Oxygen Free Copper (OFCu), Dispersion Strengthened Copper (DSCu), TZM, W5Re and W-Cu as a heat sink material. It should be noted that W-Cu is first proposed for a heat sink application of the ITER divertor plate. The finite element analyses were performed for the residual stress induced by brazing, thermal response and thermal stresses under a uniform heat flux of 15 MW/sq m to the plasma facing surface. The stress free temperature of 750 C is assumed for the residual stress by brazing. Ten different geometries of the divertor were considered in the analyses including possible material combinations. The FEM results show that the material combinations of MFC-1 and W-30Cu or DSUc in the flat-plate geometry satisfy the presently accepted ITER requirements. The combinations of CX2002U and TZM or W5Re is considered a good choice in terms of residual and thermal stresses, whereas the surface temperature exceeds the ITER requirements.

Smid, I.; Akiba, Masato; Araki, Masanori; Suzuki, Satoshi; Satoh, Kazuyoshi

1993-07-01

357

Analysing the relationship between rainfalls and landslides to define a mosaic of triggering thresholds for regional-scale warning systems  

NASA Astrophysics Data System (ADS)

We propose an original approach to develop rainfall thresholds to be used in civil protection warning systems for the occurrence of landslides at regional scale (i.e. tens of thousands of kilometres), and we apply it to Tuscany, Italy (23 000 km2). Purpose-developed software is used to define statistical intensity-duration rainfall thresholds by means of an automated and standardized analysis of rainfall data. The automation and standardization of the analysis brings several advantages that in turn have a positive impact on the applicability of the thresholds to operational warning systems. Moreover, the possibility of defining a threshold in very short times compared to traditional analyses allowed us to subdivide the study area into several alert zones to be analysed independently, with the aim of setting up a specific threshold for each of them. As a consequence, a mosaic of several local rainfall thresholds is set up in place of a single regional threshold. Even if pertaining to the same region, the local thresholds vary substantially and can have very different equations. We subsequently analysed how the physical features of the test area influence the parameters and the equations of the local thresholds, and found that some threshold parameters can be put in relation with the prevailing lithology. In addition, we investigated the possible relations between effectiveness of the threshold and number of landslides used for the calibration. A validation procedure and a quantitative comparison with some literature thresholds showed that the performance of a threshold can be increased if the areal extent of its test area is reduced, as long as a statistically significant landslide sample is present. In particular, we demonstrated that the effectiveness of a warning system can be significantly enhanced if a mosaic of site-specific thresholds is used instead of a single regional threshold.

Segoni, S.; Rosi, A.; Rossi, G.; Catani, F.; Casagli, N.

2014-09-01

358

SCALE: A modular code system for performing standardized computer analyses for licensing evaluation: Functional modules F1-F8  

SciTech Connect

This Manual represents Revision 5 of the user documentation for the modular code system referred to as SCALE. The history of the SCALE code system dates back to 1969 when the current Computational Physics and Engineering Division at Oak Ridge National Laboratory (ORNL) began providing the transportation package certification staff at the U.S. Atomic Energy Commission with computational support in the use of the new KENO code for performing criticality safety assessments with the statistical Monte Carlo method. From 1969 to 1976 the certification staff relied on the ORNL staff to assist them in the correct use of codes and data for criticality, shielding, and heat transfer analyses of transportation packages. However, the certification staff learned that, with only occasional use of the codes, it was difficult to become proficient in performing the calculations often needed for an independent safety review. Thus, shortly after the move of the certification staff to the U.S. Nuclear Regulatory Commission (NRC), the NRC staff proposed the development of an easy-to-use analysis system that provided the technical capabilities of the individual modules with which they were familiar. With this proposal, the concept of the Standardized Computer Analyses for Licensing Evaluation (SCALE) code system was born. This volume consists of the section of the manual dealing with eight of the functional modules in the code. Those are: BONAMI - resonance self-shielding by the Bondarenko method; NITAWL-II - SCALE system module for performing resonance shielding and working library production; XSDRNPM - a one-dimensional discrete-ordinates code for transport analysis; XSDOSE - a module for calculating fluxes and dose rates at points outside a shield; KENO IV/S - an improved monte carlo criticality program; COUPLE; ORIGEN-S - SCALE system module to calculate fuel depletion, actinide transmutation, fission product buildup and decay, and associated radiation source terms; ICE.

NONE

1997-03-01

359

NUMERICAL ANALYSES FOR TREATING DIFFUSION IN SINGLE-, TWO-, AND THREE-PHASE BINARY ALLOY SYSTEMS  

NASA Technical Reports Server (NTRS)

This package consists of a series of three computer programs for treating one-dimensional transient diffusion problems in single and multiple phase binary alloy systems. An accurate understanding of the diffusion process is important in the development and production of binary alloys. Previous solutions of the diffusion equations were highly restricted in their scope and application. The finite-difference solutions developed for this package are applicable for planar, cylindrical, and spherical geometries with any diffusion-zone size and any continuous variation of the diffusion coefficient with concentration. Special techniques were included to account for differences in modal volumes, initiation and growth of an intermediate phase, disappearance of a phase, and the presence of an initial composition profile in the specimen. In each analysis, an effort was made to achieve good accuracy while minimizing computation time. The solutions to the diffusion equations for single-, two-, and threephase binary alloy systems are numerically calculated by the three programs NAD1, NAD2, and NAD3. NAD1 treats the diffusion between pure metals which belong to a single-phase system. Diffusion in this system is described by a one-dimensional Fick's second law and will result in a continuous composition variation. For computational purposes, Fick's second law is expressed as an explicit second-order finite difference equation. Finite difference calculations are made by choosing the grid spacing small enough to give convergent solutions of acceptable accuracy. NAD2 treats diffusion between pure metals which form a two-phase system. Diffusion in the twophase system is described by two partial differential equations (a Fick's second law for each phase) and an interface-flux-balance equation which describes the location of the interface. Actual interface motion is obtained by a mass conservation procedure. To account for changes in the thicknesses of the two phases as diffusion progresses, a variable grid technique developed by Murray and Landis is employed. These equations are expressed in finite difference form and solved numerically. Program NAD3 treats diffusion between pure metals which form a two-phase system with an intermediate third phase. Diffusion in the three-phase system is described by three partial differential expressions of Fick's second law and two interface-flux-balance equations. As with the two-phase case, a variable grid finite difference is used to numerically solve the diffusion equations. Computation time is minimized without sacrificing solution accuracy by treating the three-phase problem as a two-phase problem when the thickness of the intermediate phase is less than a preset value. Comparisons between these programs and other solutions have shown excellent agreement. The programs are written in FORTRAN IV for batch execution on the CDC 6600 with a central memory requirement of approximately 51K (octal) 60 bit words.

Tenney, D. R.

1994-01-01

360

Isometric section of the Co-Bi-Te system at 670/sup 0/Kstructural-analyses,  

SciTech Connect

It is established that three solid solutions, based on CoTe/sub 2/ with bismuth contents up to approx. 25 at. %, are formed at a constant Co concentration, equal to 33.3 at. %. These three solid solutions are found to be in equilibrium with cobalt and all binary compounds of the Co-Bi-Te system. It is demonstrated that the Co-Bi/sub 2/Te/sub 3/ section is not quasibinary. Cobalt and binary compounds of the Co-Te and Bi-Te systems are found to be in equilibrium with the delta-solid solution. The difference between the alloys are related to changes in the unit-cell parameters of the solid solution with the alloy composition.

Abrikosov, N.Kh.; Petrova, L.I.; Dudkin, L.D.; Sokolova, V.M.

1987-10-01

361

Fully automated multifunctional ultrahigh pressure liquid chromatography system for advanced proteome analyses  

SciTech Connect

A multi-functional liquid chromatography system that performs 1-dimensional, 2-dimensional (strong cation exchange/reverse phase liquid chromatography, or SCX/RPLC) separations, and online phosphopeptides enrichment using a single binary nano-flow pump has been developed. With a simple operation of a function selection valve, which is equipped with a SCX column and a TiO2 (titanium dioxide) column, a fully automated selection of three different experiment modes was achieved. Because the current system uses essentially the same solvent flow paths, the same trap column, and the same separation column for reverse-phase separation of 1D, 2D, and online phosphopeptides enrichment experiments, the elution time information obtained from these experiments is in excellent agreement, which facilitates correlating peptide information from different experiments.

Lee, Jung Hwa; Hyung, Seok-Won; Mun, Dong-Gi; Jung, Hee-Jung; Kim, Hokeun; Lee, Hangyeore; Kim, Su-Jin; Park, Kyong Soo; Moore, Ronald J.; Smith, Richard D.; Lee, Sang-Won

2012-08-03

362

Calculations & Analyses to Support K West Basin Canister Cleaning System Project A-2A  

SciTech Connect

Approximately 2,300 metric tons of Spent Nuclear Fuel (SNF) are currently stored within two water filled pools, the 105 K East (KE) fuel storage basin and the 105 K West (KW) fuel storage basin at the US. Department of Energy, Richland Operations Office. The SNF Project is responsible for operation of the K Basins and for the materials within them. A subproject to the SNF Project is the Debris Removal Subproject, which is responsible for removal of empty canisters and lids form the basins. This revised document reviews calculations, originally prepared by COGEMA Engineering, for changes due to relocation of the Canister Cleaning System (CCS) from the Dummy Elevator Pit to the Tech View Pit Area and the elimination of the High Pressure Cleaning System.

SMITH, S.O.

2001-09-17

363

Development and Evaluation of a Formal-Analytical Usability Analysing Tool for Medical Devices and Systems  

Microsoft Academic Search

\\u000a Technological progress in the field of Computer-Assisted Surgery (CAS) not only leads to an enhancement in efficiency and\\u000a effectiveness concerning therapeutic results but also to a change of the Human-Computer-Interaction characteristics in the\\u000a operating room (OR). Deficiencies in the use process of CAS systems bring along high potential for hazardous human-induced\\u000a failures implicating higher risks for patients and physicians during

A. Janß; W. Lauer; K. Radermacher

364

Deterministic and stochastic analyses of fracture processes in a brittle microstructure system  

Microsoft Academic Search

Variations in constituent properties, phase morphology, and phase distribution cause deformation and failure at the microstructural level to be inherently stochastic. This paper focuses on the stochasticity of fracture processes that arises as a result of measurement uncertainties in the properties of the constituents in the heterogeneous microstructures of an Al2O3\\/TiB2 ceramic composite system. Basic postulate here is that for

Vikas Tomar; Min Zhou

2005-01-01

365

DART: a software to analyse root system architecture and development from captured images  

Microsoft Academic Search

Image analysis is used in numerous studies of root system architecture (RSA). To date, fully automatic procedures have not\\u000a been good enough to completely replace alternative manual methods. DART (Data Analysis of Root Tracings) is freeware based\\u000a on human vision to identify roots, particularly across time-series. Each root is described by a series of ordered links encapsulating\\u000a specific information and

Jacques Le Bot; Valérie Serra; José Fabre; Xavier Draye; Stéphane Adamowicz; Loïc Pagès

2010-01-01

366

Envelope and order domain analyses of a nonlinear torsional system decelerating under multiple order frictional torque  

NASA Astrophysics Data System (ADS)

The broader goal of this article is to re-examine the classical machinery shut down vibration problem in the context of a two degree of freedom nonlinear torsional system that essentially describes a braking system example. In particular, resonant amplifications during deceleration, as excited by a multi-order rotor surface distortion and pad friction regime, are investigated using a nonlinear model, and the order domain predictions are successfully compared with an experiment. Then a quasi-linear model at higher speeds is proposed and analytically solved to obtain closed form expressions for speed-dependent torque as well as its envelope curve. The Hilbert transform is also utilized to successfully calculate the envelope curves of both quasi-linear and nonlinear systems. Finally, the multi-term harmonic balance method is applied to construct semi-analytical solutions of the nonlinear torsional model, and the order domain results are successfully compared with measurements. New analytical solutions provide more insight to the speed-dependent characteristics given instantaneous frequency excitation.

Sen, Osman Taha; Dreyer, Jason T.; Singh, Rajendra

2013-02-01

367

Analysing stratified medicine business models and value systems: innovation-regulation interactions.  

PubMed

Stratified medicine offers both opportunities and challenges to the conventional business models that drive pharmaceutical R&D. Given the increasingly unsustainable blockbuster model of drug development, due in part to maturing product pipelines, alongside increasing demands from regulators, healthcare providers and patients for higher standards of safety, efficacy and cost-effectiveness of new therapies, stratified medicine promises a range of benefits to pharmaceutical and diagnostic firms as well as healthcare providers and patients. However, the transition from 'blockbusters' to what might now be termed 'niche-busters' will require the adoption of new, innovative business models, the identification of different and perhaps novel types of value along the R&D pathway, and a smarter approach to regulation to facilitate innovation in this area. In this paper we apply the Innogen Centre's interdisciplinary ALSIS methodology, which we have developed for the analysis of life science innovation systems in contexts where the value creation process is lengthy, expensive and highly uncertain, to this emerging field of stratified medicine. In doing so, we consider the complex collaboration, timing, coordination and regulatory interactions that shape business models, value chains and value systems relevant to stratified medicine. More specifically, we explore in some depth two convergence models for co-development of a therapy and diagnostic before market authorisation, highlighting the regulatory requirements and policy initiatives within the broader value system environment that have a key role in determining the probable success and sustainability of these models. PMID:22440585

Mittra, James; Tait, Joyce

2012-09-15

368

Radiological and toxicological analyses of tank 241-AY-102 and tank 241-C-106 ventilation systems  

SciTech Connect

The high heat content solids contained in Tank 241-C-106 are to be removed and transferred to Tank 241-AY-102 by sluicing operations, to be authorized under project W320. While sluicing operations are underway, the state of these tanks will be transformed from unagitated to agitated. This means that the partition fraction which describes the aerosol content of the head space will increase from IE-10 to IE-8 (see WHC-SD-WM-CN062, Rev. 2 for discussion of partition fractions). The head spare will become much more loaded with suspended material. Furthermore, the nature of this suspended material can change significantly: sluicing could bring up radioactive solids which normally would lay under many meters of liquid supernate. It is assumed that the headspace and filter aerosols in Tank 241-AY-102 are a 90/10 liquid/solid split. It is further assumed that the sluicing line, the headspace in Tank 241-C-106, and the filters on Tank 241-C-106 contain aerosols which are a 67/33 liquid/solid split. The bases of these assumptions are discussed in Section 3.0. These waste compositions (referred to as mitigated compositions) were used in Attachments 1 through 4 to calculate survey meter exposure rates per liter of inventory in the various system components. Three accident scenarios are evaluated: a high temperature event which melts or burns the HEPA filters and causes releases from other system components; an overpressure event which crushes and blows out the HEPA filters and causes releases from other system components; and an unfiltered release of tank headspace air. The initiating event for the high temperature release is a fire caused by a heater malfunction inside the exhaust dust or a fire outside the duct. The initiating event for the overpressure event could be a steam bump which over pressurizes the tank and leads to a blowout of the HEPA filters in the ventilation system. The catastrophic destruction of the HEPA filters would release a fraction of the accumulated filter loadings and would lead to an unfiltered pathway from the radioactively contaminated and toxic aerosols in the head space (vapor space) of the tank into the outside environment. The initiator for the unfiltered (continuous) release scenario is wetting of the HEPA filters with an accompanying filter breach or failure of the seals surrounding the filter in the enclosure. No releases from the filters themselves are assumed in this scenario. In the absence of controls, the exhaust system would continue to expel the contaminated head space air into the outside environment in all three of these scenarios.

Himes, D.A.

1998-08-11

369

A high-resolution photon-counting breast CT system with tensor-framelet based iterative image reconstruction for radiation dose reduction.  

PubMed

Both computer simulations and experimental phantom studies were carried out to investigate the radiation dose reduction with tensor framelet based iterative image reconstruction (TFIR) for a dedicated high-resolution spectral breast computed tomography (CT) based on a silicon strip photon-counting detector. The simulation was performed with a 10?cm-diameter water phantom including three contrast materials (polyethylene, 8?mg?ml(-1) iodine and B-100 bone-equivalent plastic). In the experimental study, the data were acquired with a 1.3?cm-diameter polymethylmethacrylate (PMMA) phantom containing iodine in three concentrations (8, 16 and 32?mg?ml(-1)) at various radiation doses (1.2, 2.4 and 3.6?mGy) and then CT images were reconstructed using the filtered-back-projection (FBP) technique and the TFIR technique, respectively. The image quality between these two techniques was evaluated by the quantitative analysis on contrast-to-noise ratio (CNR) and spatial resolution that was evaluated using the task-based modulation transfer function (MTF). Both the simulation and experimental results indicated that the task-based MTF obtained from TFIR reconstruction with one-third of the radiation dose was comparable to that from the FBP reconstruction for low contrast target. For high contrast target, the TFIR was substantially superior to the FBP reconstruction in terms of spatial resolution. In addition, TFIR was able to achieve a factor of 1.6-1.8 increase in CNR, depending on the target contrast level. This study demonstrates that the TFIR can reduce the required radiation dose by a factor of two-thirds for a CT image reconstruction compared to the FBP technique. It achieves much better CNR and spatial resolution for high contrast target in addition to retaining similar spatial resolution for low contrast target. This TFIR technique has been implemented with a graphic processing unit system and it takes approximately 10?s to reconstruct a single-slice CT image, which can potentially be used in a future multi-slit multi-slice spiral CT system. PMID:25230204

Ding, Huanjun; Gao, Hao; Zhao, Bo; Cho, Hyo-Min; Molloi, Sabee

2014-10-21

370

A high-resolution photon-counting breast CT system with tensor-framelet based iterative image reconstruction for radiation dose reduction  

NASA Astrophysics Data System (ADS)

Both computer simulations and experimental phantom studies were carried out to investigate the radiation dose reduction with tensor framelet based iterative image reconstruction (TFIR) for a dedicated high-resolution spectral breast computed tomography (CT) based on a silicon strip photon-counting detector. The simulation was performed with a 10?cm-diameter water phantom including three contrast materials (polyethylene, 8?mg?ml?1 iodine and B-100 bone-equivalent plastic). In the experimental study, the data were acquired with a 1.3?cm-diameter polymethylmethacrylate (PMMA) phantom containing iodine in three concentrations (8, 16 and 32?mg?ml?1) at various radiation doses (1.2, 2.4 and 3.6?mGy) and then CT images were reconstructed using the filtered-back-projection (FBP) technique and the TFIR technique, respectively. The image quality between these two techniques was evaluated by the quantitative analysis on contrast-to-noise ratio (CNR) and spatial resolution that was evaluated using the task-based modulation transfer function (MTF). Both the simulation and experimental results indicated that the task-based MTF obtained from TFIR reconstruction with one-third of the radiation dose was comparable to that from the FBP reconstruction for low contrast target. For high contrast target, the TFIR was substantially superior to the FBP reconstruction in terms of spatial resolution. In addition, TFIR was able to achieve a factor of 1.6–1.8 increase in CNR, depending on the target contrast level. This study demonstrates that the TFIR can reduce the required radiation dose by a factor of two-thirds for a CT image reconstruction compared to the FBP technique. It achieves much better CNR and spatial resolution for high contrast target in addition to retaining similar spatial resolution for low contrast target. This TFIR technique has been implemented with a graphic processing unit system and it takes approximately 10?s to reconstruct a single-slice CT image, which can potentially be used in a future multi-slit multi-slice spiral CT system.

Ding, Huanjun; Gao, Hao; Zhao, Bo; Cho, Hyo-Min; Molloi, Sabee

2014-10-01

371

Cycle O (CY 1991) NLS trade studies and analyses, book 2. Part 1: Avionics and systems  

NASA Technical Reports Server (NTRS)

An assessment was conducted to determine the maximum LH2 tank stretch capability based on the constraints of the manufacturing, tooling and facilities at the Michoud Assembly Facility in New Orleans, Louisiana. The maximum tank stretch was determined to be 5 ft. with minor or no modifications, a stretch of 11 ft. with some possible facility modifications and beyond 11 ft. significant new facilities are required. A cost analysis was performed to evaluate the impacts for various stretch lengths. Tasks that were defined to perform trades and studies regarding the best approach to meet requirements for the National Launch System Avionics are also discussed.

Harris, Richard; Kirkland, Zach

1992-01-01

372

Analyses and simulation of sensor structure parameters for electrical capacitance tomography system  

NASA Astrophysics Data System (ADS)

This paper describes a tomographic method is based on 8-electrode capacitance sensor. It discusses the application of finite element method in electrical capacitance tomography, and a finite element model of 8-electrode capacitance sensor is established. Capacitance sensitivity distributions can be analyzed with this method and optimal sensor design can also be done with it. A novel image reconstruction algorithm based on genetic algorithm is presented to improve quality of image reconstruction and calculating accuracy of concentration, satisfactory images can be reconstructed by using the capacitance sensitivity distributions of optimally designed system as a priori information. It provides powerful support for further application research.

Chen, Deyun; Wang, Lili; Chen, Yu

2008-02-01

373

SPARSE APPROXIMATION VIA ITERATIVE THRESHOLDING Kyle K. Herrity, Anna C. Gilbert, and Joel A. Tropp  

E-print Network

SPARSE APPROXIMATION VIA ITERATIVE THRESHOLDING Kyle K. Herrity, Anna C. Gilbert, and Joel A. Tropp present theoretical and empirical analyses for two iterative algorithms for sparse approximation that use for which General IT exactly re- covers a sparse signal is presented, in which the cumulative coherence

Tropp, Joel

374

Scoping Analyses on Tritium Permeation to VHTR Integarted Industrial Application Systems  

SciTech Connect

Tritium permeation is a very important current issue in the very high temperature reactor (VHTR) because tritium is easily permeated through high temperature metallic surfaces. Tritium permeations in the VHTR-integrated systems were investigated in this study using the tritium permeation analysis code (TPAC) that was developed by Idaho National Laboratory (INL). The INL TPAC is a numerical tool that is based on the mass balance equations of tritium containing species and hydrogen (i.e. HT, H2, HTO, HTSO4, TI) coupled with a variety of tritium sources, sink, and permeation models. In the TPAC, ternary fission and thermal neutron caption reactions with 6Li, 7Li 10B, 3He were taken into considerations as tritium sources. Purification and leakage models were implemented as main tritium sinks. Permeation of tritium and H2 through pipes, vessels, and heat exchangers were considered as main tritium transport paths. In addition, electroyzer and isotope exchange models were developed for analyzing hydrogen production systems including high temperature electrolysis (HTSE) and sulfur-iodine processes.

Chang H. Oh; Eung S. Kim

2011-03-01

375

Analyses and tests for design of an electro-impulse de-icing system  

NASA Technical Reports Server (NTRS)

De-icing of aircraft by using the electro-magnetic impulse phenomenon was proposed and demonstrated in several European countries. However, it is not available as a developed system due to lack of research on the basic physical mechanisms and necessary design parameters. The de-icing is accomplished by rapidly discharging high voltage capacitors into a wire coil rigidly supported just inside the aircraft skin. Induced eddy currents in the skin create a repulsive force resulting in a hammer-like force which cracks, de-bonds, and expels ice on the skin surface. The promised advantages are very low energy, high reliability of de-icing, and low maintenance. Three years of Electo-Impulse De-icing (EIDI) research is summarized and the analytical studies and results of testing done in the laboratory, in the NASA Icing Research Tunnel, and in flight are presented. If properly designed, EIDI was demonstrated to be an effective and practical ice protection system for small aircraft, turbojet engine inlets, elements of transport aircraft, and shows promise for use on helicopter rotor blades. Included are practical techniques of fabrication of impulse coils and their mountings. The use of EIDI with nonmetallic surface materials is also described.

Zumwalt, G. W.; Schrag, R. L.; Bernhart, W. D.; Friedberg, R. A.

1985-01-01

376

System Analyses of Pneumatic Technology for High Speed Civil Transport Aircraft  

NASA Technical Reports Server (NTRS)

The primary aspiration of this study was to objectively assess the feasibility of the application of a low speed pneumatic technology, in particular Circulation Control (CC) to an HSCT concept. Circulation Control has been chosen as an enabling technology to be applied on a generic High Speed Civil Transport (HSCT). This technology has been proven for various subsonic vehicles including flight tests on a Navy A-6 and computational application on a Boeing 737. Yet, CC has not been widely accepted for general commercial fixed-wing use but its potential has been extensively investigated for decades in wind tunnels across the globe for application to rotorcraft. More recently, an experimental investigation was performed at Georgia Tech Research Institute (GTRI) with application to an HSCT-type configuration. The data from those experiments was to be applied to a full-scale vehicle to assess the impact from a system level point of view. Hence, this study attempted to quantitatively assess the impact of this technology to an HSCT. The study objective was achieved in three primary steps: 1) Defining the need for CC technology; 2) Wind tunnel data reduction; 3) Detailed takeoff/landing performance assessment. Defining the need for the CC technology application to an HSCT encompassed a preliminary system level analysis. This was accomplished through the utilization of recent developments in modern aircraft design theory at Aerospace Systems Design Laboratory (ASDL). These developments include the creation of techniques and methods needed for the identification of technical feasibility show stoppers. These techniques and methods allow the designer to rapidly assess a design space and disciplinary metric enhancements to enlarge or improve the design space. The takeoff and landing field lengths were identified as the concept "show-stoppers". Once the need for CC was established, the actual application of data and trends was assessed. This assessment entailed a reduction of the wind tunnel data from the experiments performed by Mr. Bob Englar at the GTRI. Relevant data was identified and manipulated based on the required format of the analysis tools utilized. Propulsive, aerodynamic, duct sizing, and vehicle sizing investigations were performed and information supplied to a detailed takeoff and landing tool, From the assessments, CC was shown to improve the low speed performance metrics, which were previously not satisfied. An HSCT with CC augmentation does show potential for full-scale application. Yet, an economic assessment of an HSCT with and without CC showed that a moderate penalty was incurred from the increased RDT&E costs associated with developing the CC technology and slight increases in empty weight.

Mavris, Dimitri N.; Tai, Jimmy C.; Kirby, Michelle M.; Roth, Bryce A.

1999-01-01

377

Kinetic Analyses of Data from a Human Serum Albumin Assay Using the liSPR System.  

PubMed

We used the interaction between human serum albumin (HSA) and a high-affinity antibody to evaluate binding affinity measurements by the bench-top liSPR system (capitalis technology GmbH). HSA was immobilized directly onto a carboxylated sensor layer, and the mechanism of interaction between the antibody and HSA was investigated. The bivalence and heterogeneity of the antibody caused a complex binding mechanism. Three different interaction models (1:1 binding, heterogeneous analyte, bivalent analyte) were compared, and the bivalent analyte model best fit the curves obtained from the assay. This model describes the interaction of a bivalent analyte with one or two ligands (A + L ? LA + L ? LLA). The apparent binding affinity for this model measured 37 pM for the first reaction step, and 20 pM for the second step. PMID:25607476

Henseleit, Anja; Pohl, Carolin; Kaltenbach, Hans-Michael; Hettwer, Karina; Simon, Kirsten; Uhlig, Steffen; Haustein, Natalie; Bley, Thomas; Boschke, Elke

2015-01-01

378

LOCA analyses for nuclear steam supply systems with upper head injection. [PWR  

SciTech Connect

The term Upper Head Injection describes a relatively new addition to a nuclear reactor's emergency cooling system. With this feature, water is delivered directly to the top of the reactor vessel during a loss-of-coolant accident, in addition to the later injection of coolant into the primary operating loops. Established computer programs, with various modifications to models for heat transfer and two-phase flow, were used to analyze a transient following a large break in one of the main coolant loops of a reactor equipped with upper head injection. The flow and heat transfer modifications combined to yield fuel cladding temperatures during blowdown which were as much as 440K (800/sup 0/F) lower than were obtained with standard versions of the codes (for best estimate calculations). The calculations also showed the need for more uniformity of applications of heat transfer models in the computer programs employed.

Byers, R.K.; Bartel, T.J.

1980-01-01

379

Melatonin, the circadian multioscillator system and health: the need for detailed analyses of peripheral melatonin signaling.  

PubMed

Evidence is accumulating regarding the importance of circadian core oscillators, several associated factors, and melatonin signaling in the maintenance of health. Dysfunction of endogenous clocks, melatonin receptor polymorphisms, age- and disease-associated declines of melatonin likely contribute to numerous diseases including cancer, metabolic syndrome, diabetes type 2, hypertension, and several mood and cognitive disorders. Consequences of gene silencing, overexpression, gene polymorphisms, and deviant expression levels in diseases are summarized. The circadian system is a complex network of central and peripheral oscillators, some of them being relatively independent of the pacemaker, the suprachiasmatic nucleus. Actions of melatonin on peripheral oscillators are poorly understood. Various lines of evidence indicate that these clocks are also influenced or phase-reset by melatonin. This includes phase differences of core oscillator gene expression under impaired melatonin signaling, effects of melatonin and melatonin receptor knockouts on oscillator mRNAs or proteins. Cross-connections between melatonin signaling pathways and oscillator proteins, including associated factors, are discussed in this review. The high complexity of the multioscillator system comprises alternate or parallel oscillators based on orthologs and paralogs of the core components and a high number of associated factors with varying tissue-specific importance, which offers numerous possibilities for interactions with melatonin. It is an aim of this review to stimulate research on melatonin signaling in peripheral tissues. This should not be restricted to primary signal molecules but rather include various secondarily connected pathways and discriminate between direct effects of the pineal indoleamine at the target organ and others mediated by modulation of oscillators. PMID:22034907

Hardeland, Rüdiger; Madrid, Juan Antonio; Tan, Dun-Xian; Reiter, Russel J

2012-03-01

380

Metagenome analyses of corroded concrete wastewater pipe biofilms reveal a complex microbial system  

PubMed Central

Background Concrete corrosion of wastewater collection systems is a significant cause of deterioration and premature collapse. Failure to adequately address the deteriorating infrastructure networks threatens our environment, public health, and safety. Analysis of whole-metagenome pyrosequencing data and 16S rRNA gene clone libraries was used to determine microbial composition and functional genes associated with biomass harvested from crown (top) and invert (bottom) sections of a corroded wastewater pipe. Results Taxonomic and functional analysis demonstrated that approximately 90% of the total diversity was associated with the phyla Actinobacteria, Bacteroidetes, Firmicutes and Proteobacteria. The top (TP) and bottom pipe (BP) communities were different in composition, with some of the differences attributed to the abundance of sulfide-oxidizing and sulfate-reducing bacteria. Additionally, human fecal bacteria were more abundant in the BP communities. Among the functional categories, proteins involved in sulfur and nitrogen metabolism showed the most significant differences between biofilms. There was also an enrichment of genes associated with heavy metal resistance, virulence (protein secretion systems) and stress response in the TP biofilm, while a higher number of genes related to motility and chemotaxis were identified in the BP biofilm. Both biofilms contain a high number of genes associated with resistance to antibiotics and toxic compounds subsystems. Conclusions The function potential of wastewater biofilms was highly diverse with level of COG diversity similar to that described for soil. On the basis of the metagenomic data, some factors that may contribute to niche differentiation were pH, aerobic conditions and availability of substrate, such as nitrogen and sulfur. The results from this study will help us better understand the genetic network and functional capability of microbial members of wastewater concrete biofilms. PMID:22727216

2012-01-01

381

Association Study between Lead and Zinc Accumulation at Different Physiological Systems of Cattle by Canonical Correlation and Canonical Correspondence Analyses  

SciTech Connect

Pb pollution from automobile exhausts around highways is a persistent problem in India. Pb intoxication in mammalian body is a complex phenomenon which is influence by agonistic and antagonistic interactions of several other heavy metals and micronutrients. An attempt has been made to study the association between Pb and Zn accumulation in different physiological systems of cattles (n = 200) by application of both canonical correlation and canonical correspondence analyses. Pb was estimated from plasma, liver, bone, muscle, kidney, blood and milk where as Zn was measured from all these systems except bone, blood and milk. Both statistical techniques demonstrated that there was a strong association among blood-Pb, liver-Zn, kidney-Zn and muscle-Zn. From observations, it can be assumed that Zn accumulation in cattles' muscle, liver and kidney directs Pb mobilization from those organs which in turn increases Pb pool in blood. It indicates antagonistic activity of Zn to the accumulation of Pb. Although there were some contradictions between the observations obtained from the two different statistical methods, the overall pattern of Pb accumulation in various organs as influenced by Zn were same. It is mainly due to the fact that canonical correlation is actually a special type of canonical correspondence analyses where linear relationship is followed between two groups of variables instead of Gaussian relationship.

Karmakar, Partha [Dept. of Mathematics, Jalpaiguri Govt. Engineering College, Jalpaiguri-735102, West Bengal (India); Das, Pradip Kumar [Dept. of Veterinary Physiology, West Bengal University of Animal and Fishery Sciences, Kolkata-700037, West Bengal (India); Mondal, Seema Sarkar [Dept. of Mathematics, National Institute of Technology, Durgapur- 713209, West Bengal (India); Karmakar, Sougata [Dept. of Design, IIT Guwahati, Guwahati-781039, Assam (India); Mazumdar, Debasis [Dept. of Agricultural Statistics, Bidhan Chandra Krishi Viswavidyalaya, Mahanpur, Nadia- 741252, West Bengal (India)

2010-10-26

382

Risk analyses for a water-supply system; Occoquan Reservoir, Fairfax and Prince William Counties, Virginia  

USGS Publications Warehouse

Two techniques for evaluation risks in the operation of a water-supply system are demonstrated. Both rely on reconstructed historical streamflow data to develop estimates of the probabilities of certain specific events occurring in the future. These techniques are applied to the Occoquan Reservoir in Fairfax and Prince William Counties, Va., which was experiencing an unprecedented low level of storage in the autumn of 1977. In the first technique, the general risk analysis model (GRAM), simulations of the reservoir 's contents are carried out under a set of assumptions about withdrawal rates and emergency procedures. The results of the GRAM simulation for the Occoquan Reservoir are in the form of estimates of the probabilities that in any year certain emergency procedures will have to be invoked. These estimates are given for a range of rates of withdrawals and for four different stages of emergency actions. The second technique is position analysis. In this procedure probability distributions of future storages are estimated under existing storage conditions and an assumed rate of withdrawal from the reservoir. The position analysis which was initialized at the October 1, 1977, conditions indicates that the probability of entering a Stage III emergency (the prohibition of all uses of water nonessential to life, health, and safety) in the autumn of 1977 or winter of 1978 was 10 percent at that time. (Woodard-USGS)

Hirsch, Robert M.

1978-01-01

383

Advanced computational analyses for design and control of pumped liquid loop systems  

NASA Astrophysics Data System (ADS)

Computational procedures are clearly shown in the tables in such a staged way that one may easily produce design calculations of cold plates, space radiators, and single-phase fluid loop systems. All the procedures are incorporated into a design code which can deal with two types of cold plates, five types of space radiators, and five configurations of a fluid loop mechanically driven by either rotodynamic or volumetric displacement. Equivalent hydraulic diameters, heat transfer area densities, dry weights, and pressure losses are calculated over a wide range of parameters to give demonstrative examples of design practices. For cold plate design optimization, the weight and the pressure loss are displayed in the figures as functions of baseplate area, width to length ratio, or diameter to diamter/height ratio. Several figures are then placed to understand the off-design heat absorption/rejection capability of a cold plate/flat radiator and to show the weight penalty of a curved radiator. An algorithm for flow modulation of a single loop and that of coupled two loops are constructed according to nine ways of cold plate temperature regulations. The algorithms are summarized in the tables on which another code is formulated. The required flow modulation rate versus the thermal load is shown in the figures as illustrative examples of loop control.

Furukawa, Masao

384

Osiris: accessible and reproducible phylogenetic and phylogenomic analyses within the Galaxy workflow management system  

PubMed Central

Background Phylogenetic tools and ‘tree-thinking’ approaches increasingly permeate all biological research. At the same time, phylogenetic data sets are expanding at breakneck pace, facilitated by increasingly economical sequencing technologies. Therefore, there is an urgent need for accessible, modular, and sharable tools for phylogenetic analysis. Results We developed a suite of wrappers for new and existing phylogenetics tools for the Galaxy workflow management system that we call Osiris. Osiris and Galaxy provide a sharable, standardized, modular user interface, and the ability to easily create complex workflows using a graphical interface. Osiris enables all aspects of phylogenetic analysis within Galaxy, including de novo assembly of high throughput sequencing reads, ortholog identification, multiple sequence alignment, concatenation, phylogenetic tree estimation, and post-tree comparative analysis. The open source files are available on in the Bitbucket public repository and many of the tools are demonstrated on a public web server (http://galaxy-dev.cnsi.ucsb.edu/osiris/). Conclusions Osiris can serve as a foundation for other phylogenomic and phylogenetic tool development within the Galaxy platform. PMID:24990571

2014-01-01

385

3D niche microarrays for systems-level analyses of cell fate  

PubMed Central

The behaviour of mammalian cells in a tissue is governed by the three-dimensional (3D) microenvironment and involves a dynamic interplay between biochemical and mechanical signals provided by the extracellular matrix (ECM), cell–cell interactions and soluble factors. The complexity of the microenvironment and the context-dependent cell responses that arise from these interactions have posed a major challenge to understanding the underlying regulatory mechanisms. Here we develop an experimental paradigm to dissect the role of various interacting factors by simultaneously synthesizing more than 1,000 unique microenvironments with robotic nanolitre liquid-dispensing technology and by probing their effects on cell fate. Using this novel 3D microarray platform, we assess the combined effects of matrix elasticity, proteolytic degradability and three distinct classes of signalling proteins on mouse embryonic stem cells, unveiling a comprehensive map of interactions involved in regulating self-renewal. This approach is broadly applicable to gain a systems-level understanding of multifactorial 3D cell–matrix interactions. PMID:25027775

Ranga, A.; Gobaa, S.; Okawa, Y.; Mosiewicz, K.; Negro, A.; Lutolf, M. P.

2014-01-01

386

System Analyses Driving Improved Aerothermodynamic Lay-Out of the SpaceLiner Configuration  

NASA Astrophysics Data System (ADS)

The revolutionary ultrafast passenger transport SpaceLiner is under investigation at DLR since 2005. The two-stage, fully reusable vehicle is powered by rocket engines. The maximum achieved velocity, depending on the configuration or mission type, is beyond 6.5 km/s putting some challenging aerothermal requirements on the vehicle. At the lower end of the speed-range, the SpaceLiner should have the smallest possible flight velocity for landing with an acceptable angle of attack. The focus of the paper is on all system aspects including the SpaceLiner's flight performance which have an impact on the aerodynamic configuration. A preliminary sizing of both stages's passive TPS is done. At the vehicle's leading edges heat fluxes and hence equilibrium temperatures temporarily reach excessive valuesrequiring advanced active transpiration cooling. An experimental campaign is run at the DLR arc- heated facility to increase the TRL of this promising cooling technology. An aerodynamic shape optimization taking into account trim drag aspects and latest status of the vehicle design and flight profile is described.

Sippel, M.; van Foreest, A.; Dietlein, I.; Schwanekamp, T.; Kopp, A.

2011-08-01

387

An Ice Core Melter System for Continuous Major and Trace Chemical Analyses of a New Mt. Logan Summit Ice Core  

NASA Astrophysics Data System (ADS)

The ice core melter system at the University of Maine Climate Change Institute has been recently modified and updated to allow high-resolution (<1-2 cm ice/sample), continuous and coregistered sampling of ice cores, most notably the 2001 Mt. Logan summit ice core (187 m to bedrock), for analyses of 34 trace elements (Sr, Cd, Sb, Cs, Ba, Pb, Bi, U, As, Al, S, Ca, Ti, V, Cr, Mn, Fe, Co, Cu, Zn, REE suite) by inductively coupled plasma mass spectrometry (ICP-MS), 8 major ions (Na+, Ca2+, Mg2+, K+, Cl-, SO42-, NO3-, MSA) by ion chromatography (IC), stable water isotopes (? 18O, ? D, d) and volcanic tephra. The UMaine continuous melter (UMCoM) system is housed in a dedicated clean room with HEPA filtered air. Standard clean room procedures are employed during melting. A Wagenbach-style continuous melter system has been modified to include a pure Nickel melthead that can be easily dismantled for thorough cleaning. The system allows melting of both ice and firn without wicking of the meltwater into unmelted core. Contrary to ice core melter systems in which the meltwater is directly channeled to online instruments for continuous flow analyses, the UMCoM system collects discrete samples for each chemical analysis under ultraclean conditions. Meltwater from the pristine innermost section of the ice core is split between one fraction collector that accumulates ICP-MS samples in acid pre-cleaned polypropylene vials under a class-100 HEPA clean bench, and a second fraction collector that accumulates IC samples. A third fraction collector accumulates isotope and tephra samples from the potentially contaminated outer portion of the core. This method is advantageous because an archive of each sample remains for subsequent analyses (including trace element isotope ratios), and ICP-MS analytes are scanned for longer intervals and in replicate. Method detection limits, calculated from de-ionized water blanks passed through the entire UMCoM system, are below 10% of average Mt. Logan values. A strong correlation (R2>0.9) between Ca and S concentrations measured on different fractions of the same sample by IC and ICP-MS validates sample coregistration. Preliminary analyses of data from the 2001 Mt. Logan summit ice core confirm subannual resolution sampling and annual scale variability of major and trace elements. Accumulation rate models and isotope data suggest that annual resolution will be possible to 1000-2000 y.b.p., with multi-annual to centennial resolution for the remainder of the Holocene and possibly including the last deglaciation. Dust proxy elements, including REEs, strongly co-vary in time-series and reveal concentration ratio fluctuations interpreted as source region changes. Volcanic eruptions are characterized by elevated concentrations of S, SO42-, Cu, Sb, Zn and other trace elements. Concentrations of potential anthropogenic contaminants are also discussed.

Osterberg, E. C.; Handley, M. J.; Sneed, S. D.; Mayewski, P. A.; Kreutz, K. J.; Fisher, D. A.

2004-12-01

388

SCALE: A modular code system for performing standardized computer analyses for licensing evaluation. Control modules -- Volume 1, Revision 4  

SciTech Connect

SCALE--a modular code system for Standardized Computer Analyses Licensing Evaluation--has been developed by Oak Ridge National Laboratory at the request of the US Nuclear Regulatory Commission. The SCALE system utilizes well-established computer codes and methods within standard analysis sequences that (1) allow an input format designed for the occasional user and/or novice, (2) automate the data processing and coupling between modules, and (3) provide accurate and reliable results. System development has been directed at problem-dependent cross-section processing and analysis of criticality safety, shielding, heat transfer, and depletion/decay problems. Since the initial release of SCALE in 1980, the code system has been heavily used for evaluation of nuclear fuel facility and package designs. This revision documents Version 4.2 of the system. This manual is divided into three volumes: Volume 1--for the control module documentation, Volume 2--for the functional module documentation, and Volume 3 for the documentation of the data libraries and subroutine libraries.

Landers, N.F.; Petrie, L.M.; Knight, J.R. [Oak Ridge National Lab., TN (United States)] [and others

1995-04-01

389

Cascaded-systems analyses of photon-counting x-ray detectors  

NASA Astrophysics Data System (ADS)

Single-photon counting (SPC) x-ray imaging has the potential to improve image quality and enable new advanced energy-dependent methods. Recently, cascaded systems analysis (CSA) has been extended to the description of the detective quantum efficiency (DQE) of SPC detectors. In this article we apply the new CSA approach to the description of the DQE of hypothetical direct-conversion selenium (Sc) and cadmium zinc telluride (CdZnTc) detectors including the effects of poly-energetic x-ray spectra, stochastic conversion of x-ray energy to electron­ hole (c-h) pairs, depth-dependent collection of e-h pairs using the Hecht relation, additive electronic noise, and thresholding. Comparisons arc made to an energy-integrating model. For this simple model, with the exception of thick (1- 10 mm) Sc-bascd convertors, we found that the SPC DQE was 5-20 %greater than that of the energy­ integrating model. This trend was tnw even when additive noise was included in the SPC model and excluded from the energy-integrating model. However, the DQE of SPC detectors with poor collection efficiency (such as thick (<1 mm) Sc detectors) and high levels of additive noise can be degraded by 40-90 % for all energies and x-ray spectra considered. vVhile photon-counting approaches arc not yet ready for routine diagnostic imaging, the available DQE is equal to or higher than that of conventional energy-integrating detectors under a wide range of x-ray energies and convertor thickness. However, like energy-integrating detectors, the DQE of SPC detectors will be degraded by the combination of poor collection efficiency and high levels of additive noise.

Tanguay, Jesse; Yun, Seungman; Kim, Ho Kyung; Cunningham, Ian A.

2013-03-01

390

Systems Analyses of Advanced Brayton Cycles For High Efficiency Zero Emission Plants  

SciTech Connect

Table 1 shows that the systems efficiency, coal (HHV) to power, is 35%. Table 2 summarizes the auxiliary power consumption within the plant. Thermoflex was used to simulate the power block and Aspen Plus the balance of plant. The overall block flow diagram is presented in Figure A1.3-1 and the key unit process flow diagrams are shown in subsequent figures. Stream data are given in Table A1.3-1. Equipment function specifications are provided in Tables A1.3-2 through 17. The overall plant scheme consists of a cryogenic air separation unit supplying 95% purity O{sub 2} to GE type high pressure (HP) total quench gasifiers. The raw gas after scrubbing is treated in a sour shift unit to react the CO with H{sub 2}O to form H{sub 2} and CO{sub 2}. The gas is further treated to remove Hg in a sulfided activated carbon bed. The syngas is desulfurized and decarbonized in a Selexol acid gas removal unit and the decarbonized syngas after humidification and preheat is fired in GE 7H type steam cooled gas turbines. Intermediate pressure (IP) N{sub 2} from the ASU is also supplied to the combustors of the gas turbines as additional diluent for NOx control. A portion of the air required by the ASU is extracted from the gas turbines. The plant consists of the following major process units: (1) Air Separation Unit (ASU); (2) Gasification Unit; (3) CO Shift/Low Temperature Gas Cooling (LTGC) Unit; (4) Acid Gas Removal Unit (AGR) Unit; (5) Fuel Gas Humidification Unit; (6) Carbon Dioxide Compression/Dehydration Unit; (7) Claus Sulfur Recovery/Tail Gas Treating Unit (SRU/TGTU); and (8) Power Block.

A. D. Rao; J. Francuz; H. Liao; A. Verma; G. S. Samuelsen

2006-11-01

391

Analysing connectivity through landslide-channel geomorphic coupling in a large drainage system of Southern Romania  

NASA Astrophysics Data System (ADS)

Unlike creep, splash erosion and linear erosion which sometimes are called "continuous" slope processes, since they are perceived as causing relatively continuous erosion on slopes and a rather rapid transport towards river channels, mass movement processes, excepting flows, have a discontinuous behavior, manifesting stochastically on time intervals ranging from one year to tens of years, while the displaced material can remain suspended in different parts of the slope forming sediment stores. It is obviously why estimating the sediment delivered to the river network by landslides becomes a difficult task. Landslide control on channel dynamics is just one of the several forms of hillslope-channel coupling. Landslide-channel connectivity is relevant for understanding the way landslides are contributing to the sediment flux within catchments and how their study should be integrated in the estimation of sediment budgets. This paper explores the geomorphic coupling of landslides with river channels based on an extensive landslide inventory. The study area is a large drainage basin (> 2400 km2) in southern Romania encompassing four different geomorphic units (mountains, hills, piedmont and plain). The region is highly affected by a wide range of geomorphic processes which contribute to supplying sediments to the drainage network. The presence of a reservoir at the river outlet emphasizes the importance of estimating sediment budgets, the first stage of which consists in studying sediment sources. High sediment transport is associated to flash floods, a fraction of which is due to the slope failures occurring in response to the undercutting of river channels. Nominal classification systems as well as quantitative measures available in the connectivity literature are adopted here to describe the landslides-channels contact zones. Characteristics of the geomorphic coupling interfaces are further linked to the resulting geomorphic effects of landslides on the drainage. Observations made are useful in understanding the differences in landslide-channel connectivity characterizing the various geomorphic landscapes present in the study area.

Jurchescu, Marta

2014-05-01

392

New tools for the tracing of ancient starbursts: Analysing globular cluster systems using Lick indices  

NASA Astrophysics Data System (ADS)

We present mathematically advanced tools for the determination of age, metallicity, and mass of old Globular Clusters (CGs) using both broad-band colors and spectral indices, and we present their application to the Globular Cluster Systems (GCSs) of elliptical galaxies. Since one of the most intriguing questions of today's astronomy aims at the evolutionary connection between (young) violently interacting galaxies at high-redshift and the (old) elliptical galaxies we observe nearby, it is necessary to reveal the possibly violent star-formation history of these old galaxies. By means of evolutionary synthesis models, we can show that, using the integrated light of a galaxy's (composite) stellar content alone, it is impossible to date (and, actually, to identify) even very strong starbursts if these events took place more than two or three Gyr ago. However, since large and violent starbursts are associated with the formation of GCs, GCSs are very good tracers of the most violent starburst events in the history of their host galaxies. Using our well-established Göttingen SED (Spectral Energy Distribution) analysis tool, we can reveal the age, metallicity, mass (and possibly extinction) of GCs by comparing the observations with an extensive grid of SSP model colors. This is done in a statistically advanced and reasonable way, including their 1 ? uncertainties. However, since for all colors the evolution slows down considerably at ages older than about 8 Gyr, even with several passbands and a long wavelength base line, the results are severely uncertain for old clusters. Therefore, we incorporated empirical calibrations for Lick indices in our models and developed a Lick indices analysis tool that works in the same way as the SED analysis tool described above. We compare the theoretical possibilities and limitations of both methods as well as their results for the example of the cD galaxy NGC 1399, for which both multi-color observations and, for a subsample of clusters, spectral indices are available, and address implications for the nature and origin of the observed bimodal color distribution.

Lilly, T.; Fritze-v. Alvensleben, U.; de Grijs, R.

2005-05-01

393

Tritium Inventory in Iter First Wall and Tritium Permeation Through it Under Tokamak Operation with Disruptions  

Microsoft Academic Search

Effect of plasma disruptions on tritium inventory in the first wall of the International Thermonuclear Experimental Reactor (ITER) and tritium permeation through it is analysed. The tritium accumulation and permeation were calculated using TMAP-4 code.

Y. U. V. MARTYNENKO; P. G. Moskovkin; B. N. Kolbasov

2002-01-01

394

Large Deployable Reflector (LDR) system concept and technology definition study. Volume 1: Executive summary, analyses and trades, and system concepts  

NASA Technical Reports Server (NTRS)

A study was conducted to define reasonable and representative large deployable reflector (LDR) system concepts for the purpose of defining a technology development program aimed at providing the requisite technological capability necessary to start LDR development by the end of 1991. This volume includes the executive summary for the total study, a report of thirteen system analysis and trades tasks (optical configuration, aperture size, reflector material, segmented mirror, optical subsystem, thermal, pointing and control, transportation to orbit, structures, contamination control, orbital parameters, orbital environment, and spacecraft functions), and descriptions of three selected LDR system concepts. Supporting information is contained in appendices.

Agnew, Donald L.; Jones, Peter A.

1989-01-01

395

Iterated crowdsourcing dilemma game  

PubMed Central

The Internet has enabled the emergence of collective problem solving, also known as crowdsourcing, as a viable option for solving complex tasks. However, the openness of crowdsourcing presents a challenge because solutions obtained by it can be sabotaged, stolen, and manipulated at a low cost for the attacker. We extend a previously proposed crowdsourcing dilemma game to an iterated game to address this question. We enumerate pure evolutionarily stable strategies within the class of so-called reactive strategies, i.e., those depending on the last action of the opponent. Among the 4096 possible reactive strategies, we find 16 strategies each of which is stable in some parameter regions. Repeated encounters of the players can improve social welfare when the damage inflicted by an attack and the cost of attack are both small. Under the current framework, repeated interactions do not really ameliorate the crowdsourcing dilemma in a majority of the parameter space. PMID:24526244

Oishi, Koji; Cebrian, Manuel; Abeliuk, Andres; Masuda, Naoki

2014-01-01

396

Equivalent series system to model a multiple friction pendulum system with numerous sliding interfaces for seismic analyses  

NASA Astrophysics Data System (ADS)

Current structural analysis software programs offer few if any applicable device-specific hysteresis rules or nonlinear elements to simulate the precise mechanical behavior of a multiple friction pendulum system (MFPS) with numerous sliding interfaces. Based on the concept of subsystems, an equivalent series system that adopts existing nonlinear elements with parameters systematically calculated and mathematically proven through rigorous derivations is proposed. The aim is to simulate the characteristics of sliding motions for an MFPS isolation system with numerous concave sliding interfaces without prior knowledge of detailed information on the mobilized forces at various sliding stages. An MFPS with numerous concave sliding interfaces and one articulated or rigid slider located between these interfaces is divided into two subsystems: the first represents the concave sliding interfaces above the slider, and the second represents those below the slider. The equivalent series system for the entire system is then obtained by connecting those for each subsystem in series. The equivalent series system is validated by comparing numerical results for an MFPS with four sliding interfaces obtained from the proposed method with those from a previous study by Fenz and Constantinou. Furthermore, these numerical results demonstrate that an MFPS isolator with numerous concave sliding interfaces, which may have any number of sliding interfaces, is a good isolation device to protect structures from earthquake damage through appropriate designs with controllable mechanisms.

Tsai, C. S.; Su, H. C.; Chiang, T. C.

2014-03-01

397

SUMMARY REPORT-FY2006 ITER WORK ACCOMPLISHED  

SciTech Connect

Six parties (EU, Japan, Russia, US, Korea, China) will build ITER. The US proposed to deliver at least 4 out of 7 modules of the Central Solenoid. Phillip Michael (MIT) and I were tasked by DoE to assist ITER in development of the ITER CS and other magnet systems. We work to help Magnets and Structure division headed by Neil Mitchell. During this visit I worked on the selected items of the CS design and carried out other small tasks, like PF temperature margin assessment.

Martovetsky, N N

2006-04-11

398

PTRANSP Tests Of TGLF And Predictions For ITER  

SciTech Connect

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

2012-02-28

399

OLIVERO: the project analysing the future of olive production systems on sloping land in the Mediterranean basin.  

PubMed

From 2003 to 2006, a consortium of six European partners analysed the future of olive production systems on sloping land in the Mediterranean basin. Olive production on such land dates back to pre-Roman times, but the production systems (known by the acronym SMOPS, for "Sloping and Mountainous Olive Production Systems"), are under threat. Many are unsustainable environmentally (erosion hazard), socially (exodus of young people) or economically (high labour costs). The OLIVERO research project was possible thanks to a grant of euro1.5 million from the European Union, which gives out euro2.5 billion in subsidies annually for olive production. An extended survey conducted by the project in five sites in Portugal, Spain, Italy and Greece revealed the diversity and multifunctionality of SMOPS. Four main systems were identified as important for the future: traditional, organic, semi-intensive and intensive. The conceptual framework of OLIVERO involved six phases, ranging from the initial survey up to policy recommendations. In all phases there was intensive contact with stakeholders and institutions. End-users were identified at three levels: local, intermediate and regional, and national/international. This paper presents the highlights of the physical analysis of land and water resources, crop and land management, and economics and policies. Scenario studies gave insight into the possible future: some SMOPS will be gradually abandoned or transformed into nature conservation areas, others will exploit drip irrigation and follow the intensification patterns of agriculture in the valleys, and a third group will continue to be managed more extensively, perhaps augmenting their income with other activities (possibly off-farm) or turning to organic production systems. At the five international OLIVERO meetings held from 2003 to 2006, knowledge, experience and ideas on the future of olive production systems were intensively exchanged. A network was established for ongoing and future cooperation. Two end-user seminars were held in Matera (Italy) and Lisbon. Over 70 scientific papers have been published. PMID:17935859

Stroosnijder, Leo; Mansinho, Maria Inês; Palese, Assunta Maria

2008-11-01

400

ICRF Review: From ERASMUS To ITER  

SciTech Connect

This is a personal account of how I saw ICRF evolve since 1974, with a presentation that is ordered according to the topics: heating, antenna coupling, impurity generation/mitigation and system technology. The nature of the main issues is each time reviewed, recent findings are incorporated, and it is shown how the ICRF community has been able to react to sometimes rapidly changing demands and is indeed resolutely preparing ITER.

Weynants, R. R. [Laboratory for Plasma Physics, Association EURATOM-Belgian State, Royal Military Academy, 1000 Brussels, Belgium. Member of the Trilateral Euregio Cluster (Belgium)

2009-11-26

401

Fourier analysis of the SOR iteration  

NASA Technical Reports Server (NTRS)

The SOR iteration for solving linear systems of equations depends upon an overrelaxation factor omega. It is shown that for the standard model problem of Poisson's equation on a rectangle, the optimal omega and corresponding convergence rate can be rigorously obtained by Fourier analysis. The trick is to tilt the space-time grid so that the SOR stencil becomes symmetrical. The tilted grid also gives insight into the relation between convergence rates of several variants.

Leveque, R. J.; Trefethen, L. N.

1986-01-01

402

The detective quantum efficiency of photon-counting x-ray detectors using cascaded-systems analyses  

SciTech Connect

Purpose: Single-photon counting (SPC) x-ray imaging has the potential to improve image quality and enable new advanced energy-dependent methods. The purpose of this study is to extend cascaded-systems analyses (CSA) to the description of image quality and the detective quantum efficiency (DQE) of SPC systems. Methods: Point-process theory is used to develop a method of propagating the mean signal and Wiener noise-power spectrum through a thresholding stage (required to identify x-ray interaction events). The new transfer relationships are used to describe the zero-frequency DQE of a hypothetical SPC detector including the effects of stochastic conversion of incident photons to secondary quanta, secondary quantum sinks, additive noise, and threshold level. Theoretical results are compared with Monte Carlo calculations assuming the same detector model. Results: Under certain conditions, the CSA approach can be applied to SPC systems with the additional requirement of propagating the probability density function describing the total number of image-forming quanta through each stage of a cascaded model. Theoretical results including DQE show excellent agreement with Monte Carlo calculations under all conditions considered. Conclusions: Application of the CSA method shows that false counts due to additive electronic noise results in both a nonlinear image signal and increased image noise. There is a window of allowable threshold values to achieve a high DQE that depends on conversion gain, secondary quantum sinks, and additive noise.

Tanguay, Jesse [Robarts Research Institute and Department of Medical Biophysics, Western University, London, Ontario N6A 5C1 (Canada); Yun, Seungman [Biomedical Engineering Program, Western University, London, Ontario N6A 5C1 (Canada); School of Mechanical Engineering, Pusan National University, Jangjeon-dong, Geumjeong-gu, Busan 609-735 (Korea, Republic of); Kim, Ho Kyung [School of Mechanical Engineering, Pusan National University, Jangjeon-dong, Geumjeong-gu, Busan 609-735 (Korea, Republic of); Cunningham, Ian A. [Robarts Research Institute, Department of Medical Biophysics, and Biomedical Engineering Program, Western University, London, Ontario N6A 5C1 (Canada)

2013-04-15

403

Alternate senses of displacement along the Tsushima fault system during the Neogene based on fracture analyses near the western margin of the Japan Sea  

Microsoft Academic Search

The western margin of the Japan Sea is characterized by the existence of a N20°E-trending transcurrent fault system in the Korea strait between Korea and Kyushu. This fault system, called here the Tsushima fault system, played a major role during the opening of the Japan Sea during the Tertiary. In order to understand its displacement history, we analysed the deformation

Olivier Fabbri; Jacques Charvet; Marc Fournier

1996-01-01

404

Precursor systems analyses of automated highway systems. Activity area K AHS roadway operational analysis. Final report, September 1993-November 1994  

SciTech Connect

This study considers the roadway operational requirements of an automated highway system (AHS) in light of corresponding operational requirements for existing conventional highways with traffic operations centers (TOCs). Contrasts and similarities between TOC and AHS operations are identified. Maintenance operations and activities are the focus of the study. Similarities and contrasts between AHS and conventional highways are considered, analyzed, and discussed to raise issues risks. Urban/rural, passenger/heavy vehicle, and representative system configuration differences are covered insofar as there are significant differences among these categories of possible AHS operations. Maintenance needs and incident response requirements as they would impact as AHS operating agency are qualitatively analyzed. Two possible staged deployment scenarios for AHS are presented. The fault tolerance of the AHS is assessed. Results of interviews with personnel in charge of several existing TOCs have been summarized. The role of the driver in an AHS is discussed.

Schulze, R.; Roper, D.; Tsao, J.; Michael, B.

1995-05-01

405

Short initial length quench on CICC of ITER TF coils  

SciTech Connect

Previous quench studies performed for the International Thermonuclear Experimental Reactor (ITER) Toroidal Field (TF) Coils have led to identify two extreme families of quench: first 'severe' quenches over long initial lengths in high magnetic field, and second smooth quenches over short initial lengths in low field region. Detailed analyses and results on smooth quench propagation and detectability on one TF Cable In Conduit Conductor (CICC) with a lower propagation velocity are presented here. The influence of the initial quench energy is shown and results of computations with either a Fast Discharge (FD) of the magnet or without (failure of the voltage quench detection system) are reported. The influence of the central spiral of the conductor on the propagation velocity is also detailed. In the cases of a regularly triggered FD, the hot spot temperature criterion of 150 K (with helium and jacket) is fulfilled for an initial quench length of 1 m, whereas this criterion is exceed (Tmax ? 200 K) for an extremely short length of 5 cm. These analyses were carried out using both the Supermagnet(trade mark, serif) and Venecia codes and the comparisons of the results are also discussed.

Nicollet, S.; Ciazynski, D.; Duchateau, J.-L.; Lacroix, B. [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); Bessette, D.; Rodriguez-Mateos, F. [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance (France); Coatanea-Gouachet, M. [ELC Engineering, 350 chemin du Verladet, F-13290 Les Milles (France); Gauthier, F. [Soditech Ingenierie, 4 bis allée des Gabians, ZI La Frayère, 06150 Cannes (France)

2014-01-29

406

Short initial length quench on CICC of ITER TF coils  

NASA Astrophysics Data System (ADS)

Previous quench studies performed for the International Thermonuclear Experimental Reactor (ITER) Toroidal Field (TF) Coils have led to identify two extreme families of quench: first "severe" quenches over long initial lengths in high magnetic field, and second smooth quenches over short initial lengths in low field region. Detailed analyses and results on smooth quench propagation and detectability on one TF Cable In Conduit Conductor (CICC) with a lower propagation velocity are presented here. The influence of the initial quench energy is shown and results of computations with either a Fast Discharge (FD) of the magnet or without (failure of the voltage quench detection system) are reported. The influence of the central spiral of the conductor on the propagation velocity is also detailed. In the cases of a regularly triggered FD, the hot spot temperature criterion of 150 K (with helium and jacket) is fulfilled for an initial quench length of 1 m, whereas this criterion is exceed (Tmax ? 200 K) for an extremely short length of 5 cm. These analyses were carried out using both the Supermagnet{trade mark, serif} and Venecia codes and the comparisons of the results are also discussed.

Nicollet, S.; Bessette, D.; Ciazynski, D.; Coatanea-Gouachet, M.; Duchateau, J.-L.; Gauthier, F.; Lacroix, B.; Rodriguez-Mateos, F.

2014-01-01

407

Sensitivity of Middle Atmospheric Analyses to the Representation of Gravity-Wave Drag in the DAO's Data Assimilation System  

NASA Technical Reports Server (NTRS)

The damping of mesoscale gravity waves has important effects on the global circulation, structure, and composition of the atmosphere. A number of assimilation and forecast experiments have been conducted to examine the sensitivity of meteorological analyses and forecasts to the representation of gravity wave impacts in a data assimilation system (DAS). The experiments were conducted with the Finite-Volume (FV) DAS developed at NASA's Data Assimilation Office (DAO), The main purpose of this research is to determine the optimal combination of wave number, phase speed, wavelength, etc. for representing gravity-wave drag (GWD) in FVDAS. The GWD included in FVDAS includes a spectrum of waves, as would be forced by topography and transient motions (e.g., convection) in the troposphere. The sensitivity experiments are performed by modifying several parameters, such as the number of waves allowed, their wavelength, the background stress amplitude, etc. The results show that the assimilated fields are very sensitive to the number of gravity waves represented in the system, especially at high latitudes of the middle and upper stratosphere and mesosphere in winter. The analyzed stratopause temperature varies by up to 10K when the GWD scheme is modified from a multiple-wave scheme (using a stationary wave and waves with phase speeds of 10, 20, 30 and 40 m/s in each direction) to a single, stationary wave. Insight into the reality of the various versions of the GWD can be obtained by examining the "Observation minus Forecast" residuals from the FVDAS.

Li, Shuhua; Chern, Jiundar; Joiner, Joanna; Lin, Shian-Jiann; Pawson, Steven; daSilva, Arlindo; Atlas, Robert (Technical Monitor)

2002-01-01

408

Application of time-series analyses to the hydrological functioning of an Alpine karstic system: the case of Bange-L'Eau-Morte  

NASA Astrophysics Data System (ADS)

This paper analyses the hydrological functioning of the Bange-L’Eau-Morte karstic system using classical and original techniques, recession curves, correlation and spectral analyses, noise analysis and wavelet analyses. The main characteristics that can be deduced are the recession coefficients, the dynamic volume of storage, the response time of the system, the quickflow and baseflow components and the snowmelt characteristics. The non-stationary and timescale-dependent behaviour of the system is studied and particular features of the runoff are shown. The step-by-step use of these different techniques provides a general methodology applicable to different karstic systems to provide quantifiable and objective criteria for differentiation and comparison of karstic systems.

Mathevet, T.; Lepiller, M. L.; Mangin, A.

409

ITER Diagnostic First Wal  

SciTech Connect

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.

2012-09-21

410

Cyclic Game Dynamics Driven by Iterated Reasoning  

PubMed Central

Recent theories from complexity science argue that complex dynamics are ubiquitous in social and economic systems. These claims emerge from the analysis of individually simple agents whose collective behavior is surprisingly complicated. However, economists have argued that iterated reasoning–what you think I think you think–will suppress complex dynamics by stabilizing or accelerating convergence to Nash equilibrium. We report stable and efficient periodic behavior in human groups playing the Mod Game, a multi-player game similar to Rock-Paper-Scissors. The game rewards subjects for thinking exactly one step ahead of others in their group. Groups that play this game exhibit cycles that are inconsistent with any fixed-point solution concept. These cycles are driven by a “hopping” behavior that is consistent with other accounts of iterated reasoning: agents are constrained to about two steps of iterated reasoning and learn an additional one-half step with each session. If higher-order reasoning can be complicit in complex emergent dynamics, then cyclic and chaotic patterns may be endogenous features of real-world social and economic systems. PMID:23441191

Frey, Seth; Goldstone, Robert L.

2013-01-01

411

Performance assessment of the ITER ICRF antenna  

NASA Astrophysics Data System (ADS)

ITER's Ion Cyclotron Range of Frequencies (ICRF) system [1] comprises two antenna launchers designed by CYCLE (a consortium of European associations listed in the author affiliations above) on behalf F4E for the ITER Organisation (IO), each inserted as a Port Plug (PP) into one of ITER's Vacuum Vessel (VV) ports. Each launcher is an array of 4 toroidal by 6 poloidal RF current straps specified to couple up to 20 MW in total to the plasma in the frequency range of 40 to 55 MHz but limited to a maximum system voltage of 45 kV and limits on RF electric fields depending on their location and direction with respect to respectively the torus vacuum and the toroidal magnetic field. A crucial aspect of coupling ICRF power to plasmas is the knowledge of the plasma density profiles in the Scrape-Off Layer (SOL) and the location of the RF current straps with respect to the SOL. The launcher layout and details were optimized and its performance estimated for a worst case SOL provided by the IO. The paper summarizes the estimated performance obtained within the operational parameter space specified by IO. Aspects of the RF grounding of the whole antenna PP to the VV port and the effect of the voids between the PP and the Blanket Shielding Modules (BSM) surrounding the antenna front are discussed.

Durodié, F.; Vrancken, M.; Bamber, R.; Colas, L.; Dumortier, P.; Hancock, D.; Huygen, S.; Lockley, D.; Louche, F.; Maggiora, R.; Milanesio, D.; Messiaen, A.; Nightingale, M. P. S.; Shannon, M.; Tigwell, P.; van Schoor, M.; Wilson, D.; Winkler, K.; Cycle Team

2014-02-01

412

Finite-approximation-error-based discrete-time iterative adaptive dynamic programming.  

PubMed

In this paper, a new iterative adaptive dynamic programming (ADP) algorithm is developed to solve optimal control problems for infinite horizon discrete-time nonlinear systems with finite approximation errors. First, a new generalized value iteration algorithm of ADP is developed to make the iterative performance index function converge to the solution of the Hamilton-Jacobi-Bellman equation. The generalized value iteration algorithm permits an arbitrary positive semi-definite function to initialize it, which overcomes the disadvantage of traditional value iteration algorithms. When the iterative control law and iterative performance index function in each iteration cannot accurately be obtained, for the first time a new "design method of the convergence criteria" for the finite-approximation-error-based generalized value iteration algorithm is established. A suitable approximation error can be designed adaptively to make the iterative performance index function converge to a finite neighborhood of the optimal performance index function. Neural networks are used to implement the iterative ADP algorithm. Finally, two simulation examples are given to illustrate the performance of the developed method. PMID:25265640

Wei, Qinglai; Wang, Fei-Yue; Liu, Derong; Yang, Xiong

2014-12-01

413

Computational Challenges of Fusion Neutronics for ITER Ports  

NASA Astrophysics Data System (ADS)

This paper elaborates computational challenges tackled for providing neutronics service supplied for developing the design of the Diagnostics Equatorial and Upper Port Plugs (EPP and UPP). The aim was to guide and assist the EPP and UPP design developers with optimal shielding solutions which are characterised of maintain the diagnostics purposes of the systems together with adequate radiation shielding performance. The target parameter for the shielding optimization was the minimum of Shut-Down Dose Rate (SDDR) inside the interspace between the port back-side and ITER bioshield. This aim was reached by parametric neutronic analyses of the shielding geometry and material composition, mitigating direct streaming of neutrons from the plasma by arranging the labyrinths and horizontal rails. Variation of many geometrical parameters of the labyrinths was possible only by applying the high performance parallel computations with MCNP5 using pure MPI and hybrid OpenMP/MPI parallelization techniques on several available supercomputers. MCNP5 parallel performance assessments were carried out to find an efficient way to run the code in a parallel regime. It was found a strong scaling (up to 4096 cores) performance of the MCNP5 jobs running with analogue Monte Carlo sampling and weak scaling for the tasks with biased sampling as a variance reduction technique, such as the MCNP5 intrinsic weight window generator. Deep penetrating radiation in the complex ITER tokamak geometry combined blocks of strong attenuation of the radiation together with the void gaps along which the particles are streamed freely contributes to computation challenges of radiation transport.

Serikov, A.; Fischer, U.; Pitcher, C. S.; Suarez, A.; Weinhorst, B.

2014-06-01

414

Simulating nitrogen budgets in complex farming systems using INCA:calibration and scenario analyses for the Kervidy catchment Hydrology and Earth System Sciences, 8(4), 793802 (2004) EGU  

E-print Network

Simulating nitrogen budgets in complex farming systems using INCA:calibration and scenario analyses budgets in complex farming systems using INCA: calibration and scenario analyses for the Kervidy catchment of nitrogen (i.e. more animal N produced by the intensive farming than the N requirements of the crops

Boyer, Edmond

415

Assessment of erosion and tritium codeposition in ITER-FEAT  

NASA Astrophysics Data System (ADS)

Erosion of the first-wall and divertor, and distribution of eroded material in combination with tritium codeposition (primarily with eroded carbon) over many pulses, remain critical issues for the design, operation, and safety of a long-pulse next-step fusion device, such as ITER. These issues are currently being investigated by experiments in tokamaks and in laboratories, as well as by modelling. In this study, we analyse erosion (e.g., by sputtering, ELMs, and off-normal transients) and codeposition effects in the reduced-size ITER device, called `ITER-FEAT', with a strike-point carbon divertor target and metallic walls, for a `semi-detached' edge plasma regime using two-dimensional profiles of plasma edge parameters, modelled by the code B2-EIRENE. This paper accompanies the overview paper given by G. Janeschitz et al. [Plasma wall interactions in ITER-FEAT, these Proceedings]. Tritium codeposition with chemically eroded carbon still presents removal/control challenges, albeit to a somewhat lesser extent than in the 1998 ITER design, and demands efficient tritium inventory removal/control techniques. Due to numerous model uncertainties, not the least of which are the plasma solutions themselves, our intent is to provide a scoping analysis, defining trends and suggesting further research needs.

Federici, G.; Brooks, J. N.; Coster, D. P.; Janeschitz, G.; Kukuskhin, A.; Loarte, A.; Pacher, H. D.; Stober, J.; Wu, C. H.

2001-03-01

416

Meat Production in a Feedlot System of Zebu—Holstein Steers and Heifers with Dairy Genetics: Productive and Biological Analyses  

PubMed Central

The aim of this study was to evaluate the productive and biological efficiency of steers and heifers from dairy genetics in a feedlot system in terms of meat production. Twenty-four steers and 24 heifers at 10 monthes of age, (3/4) Zebu × (1/4) Holstein were utilized. They were distributed over four feedlot times, 30, 60, 90, and 120 days with four replications for each sex, and were slaughtered at the end of each period. The productive and biological analyses were performed through comparative slaughter to determine the body composition. Heifers presented with greater intakes (P < 0.05) of dry matter in grams per kg of body weight. Steers presented with a greater (P < 0.05) final empty body weight, carcass gain, cold carcass weight, and meat proportion in the carcass; however, heifers presented with a greater subcutaneous fat thickness (P < 0.05) and, consequently, a greater (P < 0.05) fat proportion in the carcass. We conclude that steers are more efficient in their productive performance than heifers in a feedlot. For the finishing carcass fat cover, heifers need 90 days in the feedlot. The net energy requirements for maintenance are 67?kcal/EBW0.75/d, and the net requirements of energy (NEg) and protein (NPg) for gain can be estimated by the following equations: NEg(Mcal/d) = 0.067 × EBW0.75 × EBG1.095 and NPg = 162 × EBG ? 5.62 × RE for the two sexes. PMID:25574483

Menezes, Gustavo Chamon de Castro; Valadares Filho, Sebastião de Campos; Ruas, José Reinaldo Mendes; Detmann, Edenio; Menezes, Arismar de Castro; Zanett, Diego; Mariz, Lays Débora Silva; Rennó, Luciana Navajas; da Silva Junior, Jarbas Miguel

2014-01-01

417

Outcome of Central Nervous System Relapses In Childhood Acute Lymphoblastic Leukaemia – Prospective Open Cohort Analyses of the ALLR3 Trial  

PubMed Central

The outcomes of Central Nervous System (CNS) relapses in children with acute lymphoblastic leukaemia (ALL) treated in the ALL R3 trial, between January 2003 and March 2011 were analysed. Patients were risk stratified, to receive a matched donor allogeneic transplant or fractionated cranial irradiation with continued treatment for two years. A randomisation of Idarubicin with Mitoxantrone closed in December 2007 in favour of Mitoxantrone. The estimated 3-year progression free survival for combined and isolated CNS disease were 40.6% (25·1, 55·6) and 38.0% (26.2, 49.7) respectively. Univariate analysis showed a significantly better survival for age <10 years, progenitor-B cell disease, good-risk cytogenetics and those receiving Mitoxantrone. Adjusting for these variables (age, time to relapse, cytogenetics, treatment drug and gender) a multivariate analysis, showed a poorer outcome for those with combined CNS relapse (HR 2·64, 95% CI 1·32, 5·31, p?=?0·006 for OS). ALL R3 showed an improvement in outcome for CNS relapses treated with Mitoxantrone compared to Idarubicin; a potential benefit for matched donor transplant for those with very early and early isolated-CNS relapses. Trial Registration Controlled-Trials.com ISRCTN45724312 PMID:25279465

Shanyinde, Milensu; Moorman, Anthony V.; Hancock, Jeremy P.; Sutton, Rosemary; Ancliff, Philip J.; Morgan, Mary; Goulden, Nicholas J.; Fraser, Chris; Hoogerbrugge, Peter M.; Revesz, Tamas; Darbyshire, Philip J.; Krishnan, Shekhar; Love, Sharon B.; Saha, Vaskar

2014-01-01

418

The Major Stratospheric Sudden Warming of January 2013: Analyses and Forecasts in the GEOS-5 Data Assimilation System  

NASA Astrophysics Data System (ADS)

We present diagnostics of the January 2013 major stratospheric sudden warming (SSW) event based on real-time analyses and 5-day forecasts produced by the high-resolution (0.25 degree) GEOS-5 data assimilation system (DAS) with an emphasis on coupling between the troposphere, stratosphere, and lower mesosphere. This SSW event began with a strong wavenumber 1 pattern (late Dec 2012) followed by a splitting of the vortex into a wavenumber 2 pattern (6 Jan 2013). After the SSW the polar middle stratosphere circulation remained weak, with several significant intrusions of low EPV air, until it reformed in late February. We examine the middle stratosphere evolution before, during, and after the SSW event using several metrics, including EPV maps and 3D wave activity flux vectors. The 3D wave activity fluxes highlight the importance of specific tropospheric ridge patterns to the forcing of the SSW. The high horizontal resolution of GEOS-5 enables the detailed examination of resolved gravity wave breaking in the middle stratosphere during and after the SSW associated with tropospheric topography, and reveals the advection of narrow, low EPV, filaments into the polar region. Our results highlight the usefulness of high horizontal resolution data assimilation in understanding the complex tropospheric forcing and subsequent evolution of SSW events.

Coy, L.; Wargan, K.; Manney, G. L.; Pawson, S.

2013-12-01

419

ITER safety challenges and opportunities  

SciTech Connect

Results of the Conceptual Design Activity (CDA) for the International Thermonuclear Experimental Reactor (ITER) suggest challenges and opportunities. ITER is capable of meeting anticipated regulatory dose limits,'' but proof is difficult because of large radioactive inventories needing stringent radioactivity confinement. We need much research and development (R D) and design analysis to establish that ITER meets regulatory requirements. We have a further opportunity to do more to prove more of fusion's potential safety and environmental advantages and maximize the amount of ITER technology on the path toward fusion power plants. To fulfill these tasks, we need to overcome three programmatic challenges and three technical challenges. The first programmatic challenge is to fund a comprehensive safety and environmental ITER R D plan. Second is to strengthen safety and environment work and personnel in the international team. Third is to establish an external consultant group to advise the ITER Joint Team on designing ITER to meet safety requirements for siting by any of the Parties. The first of the three key technical challenges is plasma engineering -- burn control, plasma shutdown, disruptions, tritium burn fraction, and steady state operation. The second is the divertor, including tritium inventory, activation hazards, chemical reactions, and coolant disturbances. The third technical challenge is optimization of design requirements considering safety risk, technical risk, and cost. Some design requirements are now too strict; some are too lax. Fuel cycle design requirements are presently too strict, mandating inappropriate T separation from H and D. Heat sink requirements are presently too lax; they should be strengthened to ensure that maximum loss of coolant accident temperatures drop.

Piet, S.J.

1991-01-01

420

Rayleigh Quotient Iteration in 3D, Deterministic Neutron Transport  

SciTech Connect

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

2012-01-01

421

Development and ITER relevant application of a user friendly interface (TEM) for use with the TMAP4 code  

Microsoft Academic Search

The Tritium Enclosure Model (TEM) has been developed as a user friendly interface to facilitate the application of the previously validated, verified and ITER approved TMAP4 Code. TEM (and TMAP4) dynamically analyzes the movement of tritium through structures, between structures and adjoining enclosures. Credible ITER relevant accident scenarios were developed and analyzed. The analyses considered the scenario with the cleanup

M. R. Tanaka; C. Fong; K. M. Kalyanam; S. K. Sood; M. Delisle; A. Natalizio

1995-01-01

422

Finite element response sensitivity, probabilistic response and reliability analyses of structural systems with applications to earthquake engineering  

E-print Network

and reliability analysis provides an ideal researchMy research on sensitivity and reliability analyses hasReliability and Sensitivity Meth- ods for Performance-Based Engineering” Report PEER 2003/14, Pacific Earth- quake Engineering Research

Barbato, Michele

2007-01-01

423

Activation analysis for ITER design options  

SciTech Connect

This paper presents a summary of the activation analyses that have been performed for the shielding blanket (SS/water) and for the breeding blanket (Li/V) of ITER design options. The activation code RACC-P, which has been modified for pulsed operation, has been used in these calculations. The spatial distributions of the radioactive inventory, decay heat, biological hazard potential, and the contact dose were calculated for the two designs for different operation modes and targeted fluences. A one-dimensional toroidal cylindrical geometrical model has been utilized to determine the neutron fluxes in the two designs. The results are normalized for an inboard and outboard neutron wall loadings of 0.91 and 1.2 MW/m{sup 2} respectively.

Attaya, H.

1995-09-01

424

US--ITER activation analysis  

SciTech Connect

Activation analysis has been made for the US ITER design. The radioactivity and the decay heat have been calculated, during operation and after shutdown for the two ITER phases, the Physics Phase and the Technology Phase. The Physics Phase operates about 24 full power days (FPDs) at fusion power level of 1100 MW and the Technology Phase has 860 MW fusion power and operates for about 1360 FPDs. The point-wise gamma sources have been calculated everywhere in the reactor at several times after shutdown of the two phases and are then used to calculate the biological dose everywhere in the reactor. Activation calculations have been made also for ITER divertor. The results are presented for different continuous operation times and for only one pulse. The effect of the pulsed operation on the radioactivity is analyzed. 6 refs., 12 figs., 1 tab.

Attaya, H.; Gohar, Y.; Smith, D.

1990-09-01

425

Error Field Correction in ITER  

SciTech Connect

A new method for correcting magnetic field errors in the ITER tokamak is developed using the Ideal Perturbed Equilibrium Code (IPEC). The dominant external magnetic field for driving islands is shown to be localized to the outboard midplane for three ITER equilibria that represent the projected range of operational scenarios. The coupling matrices between the poloidal harmonics of the external magnetic perturbations and the resonant fields on the rational surfaces that drive islands are combined for different equilibria and used to determine an ordered list of the dominant errors in the external magnetic field. It is found that efficient and robust error field correction is possible with a fixed setting of the correction currents relative to the currents in the main coils across the range of ITER operating scenarios that was considered.

Jong-kyu Park, Allen H. Boozer, Jonathan E. Menard, and Michael J. Schaffer

2008-05-22

426

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

2006-11-01

427

An advanced LIF-PLV system for analysing the hydrodynamics in a laboratory bubble column at higher void fractions  

NASA Astrophysics Data System (ADS)

Bubble columns are widely used in the chemical industry and biotechnology. Flow and turbulence in such an apparatus are induced by the bubble rise, and the bubble behaviour is strongly affected by swarm effects (i.e. the interaction between bubbles). For analysing the bubble swarm behaviour and simultaneously evaluating the flow structure and bubble-induced turbulence, a bubble column of 140 mm diameter and a height of 650 mm or 1,400 mm (initial water level) were considered. The bubble column was aerated with relatively fine bubbles having a mean size between about 0.5 and 4.0 mm. The gas hold-up was varied in the range between 0.5 and 19%. A two-phase pulsed-light velocimetry (PLV) system was developed to evaluate instantaneous flow fields of both rising bubbles and the continuous phase. The measurement of the liquid velocities in the bubble swarm was achieved by adding fluorescing seed particles. Images of bubbles and fluorescing tracer particles were acquired by two CCD cameras. Hence, the images from tracers and bubbles were easily separated by optical interference filters with a bandwidth corresponding to the emitting wavelength of the fluorescing tracer particles and the wavelength of the applied Nd-YAG pulsed laser, respectively. To improve the phase separation of the system, the CCD cameras were additionally placed in a non-perpendicular arrangement with respect to the light sheet. The acquired images were evaluated with the minimum-quadratic-difference algorithm. The potential of this technique for the analysis of bubbly flows with higher void fraction was explored. In order to obtain averaged velocity maps of bubble and fluid within the entire column, about 1,000 image pairs were recorded and evaluated for each phase. In addition, turbulence intensities of the fluid were deduced from the measurements. The turbulence properties were used to characterise bubble-induced turbulence for various bubble mean diameters and gas hold-ups. Moreover, the determination of the average bubble slip velocity within the bubble swarm was possible.

Bröder, D.; Sommerfeld, M.

2002-08-01

428

Potential of the ITER electron cyclotron equatorial launcher for heating and current drive at nominal and reduced fields  

NASA Astrophysics Data System (ADS)

Electron cyclotron (EC) heating and current drive (HCD), at 170?GHz, 20?MW, is one of the heating systems foreseen to assist and sustain the development of various ITER scenarios since the early phase of ITER. It is usually assumed that EC is efficient only at magnetic fields operating around full field (5.3?T) and half field (2.65?T), and most of the analyses presented so far have focused on the ECRH&CD performances at flat-top. Here, the EC capabilities are investigated for different plasma parameters corresponding to different phases of the ITER plasma discharge, from current ramp-up up to burn, and for a wide range of magnetic fields, focusing in particular on the EC potential for heating and for L- to H-mode assist. It is found that the EC system can contribute to a wide range of heating scenarios during the ramp-up of the magnetic field, significantly increasing the applicable range as a function of magnetic field as compared with traditional views.

Farina, D.; Henderson, M.; Figini, L.; Ramponi, G.; Saibene, G.

2012-03-01

429

Iterated binomial sums and their associated iterated integrals  

NASA Astrophysics Data System (ADS)

We consider finite iterated generalized harmonic sums weighted by the binomial binom{2k}{k} in numerators and denominators. A large class of these functions emerges in the calculation of massive Feynman diagrams with local operator insertions starting at 3-loop order in the coupling constant and extends the classes of the nested harmonic, generalized harmonic, and cyclotomic sums. The binomially weighted sums are associated by the Mellin transform to iterated integrals over square-root valued alphabets. The values of the sums for N ? ? and the iterated integrals at x = 1 lead to new constants, extending the set of special numbers given by the multiple zeta values, the cyclotomic zeta values and special constants which emerge in the limit N ? ? of generalized harmonic sums. We develop algorithms to obtain the Mellin representations of these sums in a systematic way. They are of importance for the derivation of the asymptotic expansion of these sums and their analytic continuation to N in {C}. The associated convolution relations are derived for real parameters and can therefore be used in a wider context, as, e.g., for multi-scale processes. We also derive algorithms to transform iterated integrals over root-valued alphabets into binomial sums. Using generating functions we study a few aspects of infinite (inverse) binomial sums.

Ablinger, J.; Blümlein, J.; Raab, C. G.; Schneider, C.

2014-11-01

430

Exact iterative reconstruction for the interior problem  

PubMed Central

There is a trend in single photon emission computed tomography (SPECT) that small and dedicated imaging systems are becoming popular. For example, many companies are developing small dedicated cardiac SPECT systems with different designs. These dedicated systems have a smaller field of view (FOV) than a full-size clinical system. Thus data truncation has become the norm rather than the exception in these systems. Therefore, it is important to develop region of interest (ROI) reconstruction algorithms using truncated data. This paper is a stepping stone toward this direction. This paper shows that the common generic iterative image reconstruction algorithms are able to exactly reconstruct the ROI under the conditions that the convex ROI is fully sampled and the image value in a sub-region within the ROI is known. If the ROI includes a sub-region that is outside the patient body, then the conditions can be easily satisfied. PMID:19741279

Zeng, Gengsheng L; Gullberg, Grant T

2010-01-01

431

Exact iterative reconstruction for the interior problem  

NASA Astrophysics Data System (ADS)

There is a trend in single photon emission computed tomography (SPECT) that small and dedicated imaging systems are becoming popular. For example, many companies are developing small dedicated cardiac SPECT systems with different designs. These dedicated systems have a smaller field of view (FOV) than a full-size clinical system. Thus data truncation has become the norm rather than the exception in these systems. Therefore, it is important to develop region of interest (ROI) reconstruction algorithms using truncated data. This paper is a stepping stone toward this direction. This paper shows that the common generic iterative image reconstruction algorithms are able to exactly reconstruct the ROI under the conditions that the convex ROI is fully sampled and the image value in a sub-region within the ROI is known. If the ROI includes a sub-region that is outside the patient body, then the conditions can be easily satisfied.

Zeng, Gengsheng L.; Gullberg, Grant T.

2009-10-01

432

Basic Process Algebra with Iteration: Completeness of its Equational Axioms  

E-print Network

Basic Process Algebra with Iteration: Completeness of its Equational Axioms Wan Fokkink CWI rewriting system, based on the axioms, and prove that this term rewrit- ing system is terminating axiomatization which incorporates one conditional axiom, namely (in our notation) x = y · x + z implies x = yz

Fokkink, Wan

433

1. Botterweg, P., et al., The EUROSEM-GRIDSEM modeling system for erosion analyses under different natural and economic conditions. Ecological  

E-print Network

1. Botterweg, P., et al., The EUROSEM-GRIDSEM modeling system for erosion analyses under different natural and economic conditions. Ecological Modelling, 1998. 108(1-3): p. 115-129. 2. Cai, Q.G., et al, China. Catena, 2005. 59(1): p. 19-33. 3. Folly, A., J.N. Quinton, and R.E. Smith, Evaluation

Quinton, John

434

ISIS++Reference Guide (Iterative Scalable Implicit Solver in C++) Version 1.1  

SciTech Connect

ISIS++ (Iterative Scalable Implicit Solver in C++) Version 1.1 is a portable, object-oriented framework for solving sparse linear systems of equations. It includes a collection of Krylov solution methods and preconditioners, as well as both uni-processor (serial) and multi-processor (scalable) matrix and vector classes. Though it was developed to solve systems of equations originating from large-scale, 3-D, finite element analyses, it has application in many other fields. This document supersedes the ISIS++ V1.0 Reference Guide, defines the V1. 1 interface specification, and includes the necessary instructions for building and running ISIS++ v 1.1 on Unix platforms. The interface is presented in annotated header format, along with background on design and implementation considerations. A finite difference modeling example problem is included to demonstrate the overall setup and use.

Alan B. Williams; Benjamin A. Allan; Kyran D. Mish; Robert L. Clay

1999-04-01

435

Biological and Molecular Analyses of the Acibenzolar-S-Methyl-Induced Systemic Acquired Resistance in Flue-Cured Tobacco Against Tomato spotted wilt virus  

Microsoft Academic Search

Mandal, B., Mandal, S., Csinos, A. S., Martinez, N., Culbreath, A. K., and Pappu, H. R. 2008. Biological and molecular analyses of the acibenzolar- S-methyl-induced systemic acquired resistance in flue-cured tobacco against Tomato spotted wilt virus. Phytopathology 98:196-204. Tomato spotted wilt virus (TSWV) is an economically important virus of flue-cured tobacco. Activation of systemic acquired resistance (SAR) by acibenzolar-S-methyl (ASM)

B. Mandal; S. Mandal; A. S. Csinos; N. Martinez; A. K. Culbreath; H. R. Pappu

2008-01-01

436

ITER plant layout and site services  

NASA Astrophysics Data System (ADS)

The ITER site has not yet been determined. Nevertheless, to develop a construction plan and a cost estimate, it is necessary to have a detailed layout of the buildings, structures and outdoor equipment integrated with the balance of plant service systems prototypical of large fusion power plants. These services include electrical power for magnet feeds and plasma heating systems, cryogenic and conventional cooling systems, compressed air, gas supplie