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


1

Decentralized method for complex task allocation in massive MAS  

Science Conference Proceedings (OSTI)

Task allocation is still a fundamental problem in Multi?Agents System (MAS). It allows the formation a coalition of agents to cooperate together in order to carry out a complex task. Generally

Zaki Brahmi; M. M. Gammoudi; Research Unit (URPAH)

2008-01-01T23:59:59.000Z

2

Resolution and Polarization Distribution in Cryogenic DNP/MAS Experiments  

E-Print Network (OSTI)

This contribution addresses four potential misconceptions associated with high-resolution dynamic nuclear polarization/magic angle spinning (DNP/MAS) experiments. First, spectral resolution is not generally compromised at ...

Barnes, Alexander

3

A Logical Framework for Modelling eMAS  

Science Conference Proceedings (OSTI)

We investigate how to explicitly represent organizational structures in epistemic multi-agent systems (eMAS). We introduce a logical framework F suitable for representing organizational structures for epistemic agents, and provide its declarative ...

Pierangelo Dell'Acqua; Luís Moniz Pereira

2003-01-01T23:59:59.000Z

4

Protein MAS NMR methodology and structural analysis of protein assemblies  

E-Print Network (OSTI)

Methodological developments and applications of solid-state magic-angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy, with particular emphasis on the analysis of protein structure, are described in this thesis. ...

Bayro, Marvin J

2010-01-01T23:59:59.000Z

5

MAS 305 Algebraic Structures II Notes 11 Autumn 2006  

E-Print Network (OSTI)

MAS 305 Algebraic Structures II Notes 11 Autumn 2006 Ring homomorphisms Definition Let R and S be rings, and let :R S be a function. Then is a ring homomorphism if (r1 +r2) = r1+r2 and (r1r2) = (r1)(r2) for all r1, r2 in R. A ring homomorphism which is a bijection is called an isomorphism

Bailey, R. A.

6

MAS NMR Study of the Metastable Solid Solution Found in the LiFePO4...  

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

MAS NMR Study of the Metastable Solid Solution Found in the LiFePO4FePO4 Sustem Title MAS NMR Study of the Metastable Solid Solution Found in the LiFePO4FePO4 Sustem Publication...

7

FTIR and 27 Al MAS NMR analysis of the effect of framework Al-and Si-defects  

E-Print Network (OSTI)

FTIR and 27 Al MAS NMR analysis of the effect of framework Al- and Si-defects in micro- and micro 2011 Keywords: Micro-mesoporous H-ZSM-5 zeolite Framework defects FTIR 27 Al MAS NMR Methanol, and their activity was investigated in transformation of methanol to low olefins, aromatics and paraffins. 27 Al MAS

Sklenak, Stepan

8

On-line Fault Diagnosis Model of the Hydropower Units Based on MAS  

Science Conference Proceedings (OSTI)

The paper introduced a novel on-line fault diagnosis system model of the hydropower units based on multi-agent system. In allusion to the classical MAS-based fault diagnosis model, it proposes a new function of information interactive between the mission-controlled ...

Liao Jiaping; Fu Bo; Chen Yu

2009-07-01T23:59:59.000Z

9

Mas Hori & Associates, California Sea Grant Extension Program -University of California and California Fisheries and Seafood Institute  

E-Print Network (OSTI)

Mas Hori & Associates, California Sea Grant Extension Program - University of California and California Fisheries and Seafood Institute Present Seafood HACCP Changes in the Revised FDA Hazards Guide

Hammock, Bruce D.

10

Research on a novel method diagnosis and maintenance for key produce plant based on MAS and NN  

Science Conference Proceedings (OSTI)

As the development of the electrical power market, the maintenance automation has become an intrinsic need to increase the overall economic efficiency of hydropower plants. A Multi-Agent System (MAS) based model for the predictive maintenance system ...

Weijin Jiang; Xiaohong Lin

2006-10-01T23:59:59.000Z

11

MAS 10.3 Seasonal Preparation 3/21/95 | Department of Energy  

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

3 Seasonal Preparation 3/21/95 3 Seasonal Preparation 3/21/95 MAS 10.3 Seasonal Preparation 3/21/95 The objective of this surveillance is to verify that the contractor is implementing appropriate measures to protect equipment and systems from damage due to the effects of cold weather. The Facility Representative evaluates systems necessary for the protection of the public and workers to determine if they have been adequately prepared for cold weather. The Facility Representative also examines other preparations for cold weather to ensure that materials are properly stored, permanent and auxiliary heating systems are functional, and other appropriate preparations have been completed. During the surveillance, the Facility Representative ensures that applicable DOE requirements have been implemented.

12

LyMAS: Predicting Large-Scale Lyman-alpha Forest Statistics from the Dark Matter Density Field  

E-Print Network (OSTI)

[abridged] We describe LyMAS (Ly-alpha Mass Association Scheme), a method of predicting clustering statistics in the Ly-alpha forest on large scales from moderate resolution simulations of the dark matter distribution, with calibration from high-resolution hydrodynamic simulations of smaller volumes. We use the "Horizon MareNostrum" simulation, a 50 Mpc/h comoving volume evolved with the adaptive mesh hydrodynamic code RAMSES, to compute the conditional probability distribution P(F_s|delta_s) of the transmitted flux F_s, smoothed (1-dimensionally) over the spectral resolution scale, on the dark matter density contrast delta_s, smoothed (3-dimensionally) over a similar scale. In this study we adopt the spectral resolution of the SDSS-III BOSS at z=2.5, and we find optimal results for a dark matter smoothing length sigma=0.3 Mpc/h (comoving). In extended form, LyMAS exactly reproduces both the 1-dimensional power spectrum and 1-point flux distribution of the hydro simulation spectra. Applied to the MareNostrum ...

Peirani, Sébastien; Colombi, Stéphane; Blaizot, Jérémy; Dubois, Yohan; Pichon, Christophe

2013-01-01T23:59:59.000Z

13

A RECOLLIMATION SHOCK 80 mas FROM THE CORE IN THE JET OF THE RADIO GALAXY 3C 120: OBSERVATIONAL EVIDENCE AND MODELING  

Science Conference Proceedings (OSTI)

We present Very Long Baseline Array observations of the radio galaxy 3C 120 at 5, 8, 12, and 15 GHz designed to study a peculiar stationary jet feature (hereafter C80) located {approx}80 mas from the core, which was previously shown to display a brightness temperature {approx}600 times larger than expected at such distances. The high sensitivity of the images-obtained between 2009 December and 2010 June-has revealed that C80 corresponds to the eastern flux density peak of an arc of emission (hereafter A80), downstream of which extends a large ({approx}20 mas in size) bubble-like structure that resembles an inverted bow shock. The linearly polarized emission closely follows that of the total intensity in A80, with the electric vector position angle distributed nearly perpendicular to the arc-shaped structure. Despite the stationary nature of C80/A80, superluminal components with speeds up to 3 {+-} 1 c have been detected downstream from its position, resembling the behavior observed in the HST-1 emission complex in M87. The total and polarized emission of the C80/A80 structure, its lack of motion, and brightness temperature excess are best reproduced by a model based on synchrotron emission from a conical shock with cone opening angle {eta} = 10 Degree-Sign , jet viewing angle {theta} = 16 Degree-Sign , a completely tangled upstream magnetic field, and upstream Lorentz factor {gamma}{sub u} = 8.4. The good agreement between our observations and numerical modeling leads us to conclude that the peculiar feature associated with C80/A80 corresponds to a conical recollimation shock in the jet of 3C 120 located at a de-projected distance of {approx}190 pc downstream from the nucleus.

Agudo, Ivan; Gomez, Jose L.; Casadio, Carolina; Roca-Sogorb, Mar [Instituto de Astrofisica de Andalucia, CSIC, Apartado 3004, 18080 Granada (Spain); Cawthorne, Timothy V., E-mail: jlgomez@iaa.es [School of Computing, Engineering and Physical Science, University of Central Lancashire, Preston PR1 2HE (United Kingdom)

2012-06-20T23:59:59.000Z

14

MAS275 Probability Modelling 2 Renewal Theory  

E-Print Network (OSTI)

, we assume that the light bulb in a room is inspected at regular intervals, and if the bulb is found to have failed it is replaced with a new one; the replacement of the light bulb here is a renewal. It is reasonable to model the lengths of time between renewals (e.g. the life- lengths of light bulbs) as random

Jordan, Jonathan

15

MAS.961 Designing Sociable Media, Spring 2001  

E-Print Network (OSTI)

This course is about social life in the on-line world. Its focus is on how the design of the interface influences people's interactions with each other and shapes the cultural mores and structures they develop. We will ...

Donath, Judith S.

16

MAS coordination and control based on stigmergy  

Science Conference Proceedings (OSTI)

This paper discusses a multi-agent coordination and control system. The system implements the PROSA architecture [12] and uses a specialized approach to stigmergy. This approach is discussed in relation to more commonplace designs based, for instance, ... Keywords: Multi-agent systems, PROSA architecture, Stigmergy

Paul Valckenaers; Hadeli; Bart Saint Germain; Paul Verstraete; Hendrik Van Brussel

2007-09-01T23:59:59.000Z

17

Surveillance Guide - MAS 10.3 Seasonal Preparation  

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

SEASONAL PREPARATION SEASONAL PREPARATION 1.0 Objective The objective of this surveillance is to verify that the contractor is implementing appropriate measures to protect equipment and systems from damage due to the effects of cold weather. The Facility Representative evaluates systems necessary for the protection of the public and workers to determine if they have been adequately prepared for cold weather. The Facility Representative also examines other preparations for cold weather to ensure that materials are properly stored, permanent and auxiliary heating systems are functional, and other appropriate preparations have been completed. During the surveillance, the Facility Representative ensures that applicable DOE requirements have been implemented.

18

MAS 305 Algebraic Structures II Notes 12 Autumn 2006  

E-Print Network (OSTI)

, b, c are elements of an integral domain R and ab = ac then either a = 0R or b = c. Proof ab = ac a(b - c) = 0R a = 0R or b - c = 0R because R has no zero- divisors. Definition Let a and b be elements of an integral domain R. Then a is an associate of b if there is a unit u in R with au = b. Lemma In an integral

Bailey, R. A.

19

MAS standard spectrum format v1.0  

Science Conference Proceedings (OSTI)

... One or more per file. Max = 64 Characters. #DATE = The calendar day-month-year in which the spectra. was recorded, in the form: DD-MMM- ...

20

Kukur?z? siloso mas?s panaudojimas bioduj? gamyboje.  

E-Print Network (OSTI)

??The work is directed for one of alternative energy resources – renewable sources of energy. The main task is to examine potential produce biogas out… (more)

Ambrazas,; Egidijus

2005-01-01T23:59:59.000Z

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


21

MAS 1: Multiscale Sensing and Actuation Architecture and Performance  

E-Print Network (OSTI)

Etc. Static Network Sampling (SNS) requires an impracticallyNetwork Sampling Sampling (SNS) (MSS) Raster Scan Sampling (

Diane Budzik; Amarjeet Singh; Per Henrik Borgstrom; Michael Stealey; Maxim Batalin; William Kaiser

2006-01-01T23:59:59.000Z

22

Surveillance Guide - MAS 10.2 Control of Measuring and Test Equipment  

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

CONTROL OF MEASURING AND TEST EQUIPMENT CONTROL OF MEASURING AND TEST EQUIPMENT 1.0 Objective The objective of this surveillance is to verify that the contractor maintains adequate control of tools, gauges, instruments, devices or systems used to inspect, test, calibrate, measure or troubleshoot safety related alarms, sensors, and detectors. Surveillance activities provide a basis for evaluating the effectiveness of the contractor's program as well as compliance with DOE requirements. 2.0 References 2.1 DOE 4330.4B, Maintenance Management Program 2.2 DOE 5700.6C, Quality Assurance 3.0 Requirements Implemented This surveillance is conducted to implement requirements MA-0003 and MA-0004 from the RL S/RID. These requirements are drawn from DOE 4330.4B.

23

Microsoft Word - 1817 Report incl GC&OMB Comments 8 20 07mas2.doc  

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

POTENTIAL BENEFITS OF DISTRIBUTED POTENTIAL BENEFITS OF DISTRIBUTED GENERATION AND RATE-RELATED ISSUES THAT MAY IMPEDE ITS EXPANSION A STUDY PURSUANT TO SECTION 1817 OF THE ENERGY POLICY ACT OF 2005 June 2007 U.S. Department of Energy EPAct 2005 SEC. 1817. STUDY OF DISTRIBUTED GENERATION. (a) Study- (1) IN GENERAL- (A) POTENTIAL BENEFITS- The Secretary, in consultation with the Federal Energy Regulatory Commission, shall conduct a study of the potential benefits of cogeneration and small power production. (B) RECIPIENTS- The benefits described in subparagraph (A) include benefits that are received directly or indirectly by-- (i) an electricity distribution or transmission service provider; (ii) other customers served by an electricity distribution or transmission service provider; and

24

Looking for an Exit: Variations on M&As and IPOs  

•sequestration •potable water •pollution control •remediation. ... • Leader of the firm's clean technology and strategic carbon counseling practice.

25

MAS 10.2 Control of Measuring and Test Equipment, 3/9/95  

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

The objective of this surveillance is to verify that the contractor maintains adequate control of tools, gauges, instruments, devices or systems used to inspect, test, calibrate, measure or...

26

MAS340 1 Turn Over SCHOOL OF MATHEMATICS AND STATISTICS Spring Semester 2010-2011  

E-Print Network (OSTI)

numerical solution of the heat equation 2 2 2 x u c t u . (3 marks) (v) If we are given that, in the heat showing the values of u at the grid points for 0t , and hence calculate the values of u at the grid points x u when 2 3 x , yxxu 2 when 0y or 1. Taking 2 1 kh , draw a suitable grid for a numerical analysis

Oakley, Jeremy

27

A Research on Strategies for Construction of MAS-Based Urban ITIS  

Science Conference Proceedings (OSTI)

In urban areas around the world, the number of trips made by vehicles has significantly increased in recent decades and resulted in frequent traffic congestions. ITIS offer optimal travel routes to road users with regard to the actual traffic state in ... Keywords: Multi-agent, ITIS, AHP, Urban traffic

Chaihou Zhao; Weiming Liu; Bei Wang

2009-12-01T23:59:59.000Z

28

Multiagent systems and information retrieval our experience with X.MAS  

Science Conference Proceedings (OSTI)

Autonomous agents and multiagent systems have been successfully applied to a number of problems and have been largely used in different application fields. In particular, in this paper we are interested in information retrieval. In fact, in this field ... Keywords: Applications, Information retrieval, Multiagent systems

Andrea Addis; Giuliano Armano; Eloisa Vargiu

2012-02-01T23:59:59.000Z

29

MAS.714J / STS.445J Technologies for Creative Learning, Fall 2004  

E-Print Network (OSTI)

This course explores how new technologies can help people learn new things in new ways. It analyzes principles and strategies underlying the design of innovative educational technologies and creative learning environments, ...

Resnick, Mitchel

30

Surveillance Guide - MAS 10.1 Implementation of the Integrated Safety Management System Process in Maintenance Activities  

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

Implementation of the Integrated Safety Management System (ISMS) Process in Implementation of the Integrated Safety Management System (ISMS) Process in Maintenance Activities 1.0 Objective The objective of this surveillance is to evaluate the effectiveness of the contractor's ISMS process with regard to maintenance activities. Surveillance activities encompass work planning and control, equipment status control, performance of maintenance, return to service, and closeout documentation. 2.0 References 2.1 DOE 4330.4B Maintenance Management Program 2.2 DOE 5480.19 Conduct of Operations for DOE Facilities 2.3 48 CFR 970.5204-2 Implementation of Environment, Safety, and Health into Work Planning and Execution 2.4 10 CFR 830.120 Quality Assurance 3.0 Requirements Implemented This surveillance is conducted to implement requirements of the

31

Capitulo 9 La de los Bernoulli de Basilea es, quizas, la familia mas famosa de las Matematicas.  

E-Print Network (OSTI)

: los ´atomos de carbono tienen valencia 4, mientras que los de hidr´ogeno, valencia 1. Se trata de un

Quirós, Fernando

32

MAS 10.1 Implementation of the Integrated Safety Management System (ISMS) Process in Maintenance Activities, 2/14/2000  

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

The objective of this surveillance is to evaluate the effectiveness of the contractor's ISMS process with regard to maintenance activities.  Surveillance activities encompass work planning and...

33

I: Low Frequency NMR and NQR Using a dc SQUID. II: Variable-temperature 13C CP/MAS of Organometallics  

E-Print Network (OSTI)

the ARIES also provides 22 TTL lines on the spectrometerand the 22 J additional TTL lines in the spectrometerthe SIO module and 22 TTL lines on the spectrometer module.

Ziegeweid, M.A.

2010-01-01T23:59:59.000Z

34

I: Low Frequency NMR and NQR Using a dc SQUID. II: Variable-temperature 13C CP/MAS of Organometallics  

E-Print Network (OSTI)

89, Hoatson, G. L. ; VoId, R. L. In NMR Basic Principles andTransient Techniques in NMR ofSolids: An Introduction toFreude, D. ; Haase, 1. In NMR Basic Principles and Progress

Ziegeweid, M.A.

2010-01-01T23:59:59.000Z

35

High-resolution MAS NMR analysis of PI3-SH3 amyloid fibrils: Backbone conformation and implications for protofilament assembly and structure  

E-Print Network (OSTI)

The SH3 domain of the PI3 kinase (PI3-SH3 or PI3K-SH3) readily aggregates into fibrils in vitro and has served as an important model system in the investigation of the molecular properties and mechanism of formation of ...

Bayro, Marvin J.

36

Flash2007-33RevenueTierDiscounts.rtf  

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

REVENUE TIER DISCOUNT REVENUE TIER DISCOUNT S* Service Category Baseline $0-$9M Tier 1 $10-34M Tier 2 $ 35-74M Tier 3 $75-149M Tier 4 $150-199M Tier 5 $200M+ Express Next Day First AM MAS MAS MAS MAS MAS MAS Express Next Day Mid-Morning MAS 21.9% 24.0% 26.9% 29.2% 30.2% Express Next Day Afternoon MAS 21.9% 24.0% 26.9% 29.2% 30.2% Express Second Day MAS 21.9% 24.0% 26.9% 29.2% 30.2% Express Third Day MAS 21.9% 24.0% 26.9% 29.2% 30.2% Intl Priority - Puerto Rico MAS MAS MAS MAS MAS MAS Intl Economy - Puerto Rico MAS MAS MAS MAS MAS MAS Same Day Service MAS MAS MAS MAS MAS MAS Standard Ground** MAS 1.7% 4.8% 13.2% 15.2% 17.3% Ground $4,000 - $40,000** Not Offered 4.8% 11.1% 15.2% 17.3% 27.9% Ground $40,000+" Not Offered 39.2% 39.2% 39.2% 39.2% 39.2% *Discounts shown EXCLUDE the waiver of fuel surcharges and are thus understated

37

Design, analysis, and testing of a precision guidance, navigation, and control system for a dual-spinning Cubesat  

E-Print Network (OSTI)

The Microsized Microwave Atmospheric Satellite (MicroMAS) combines two traditional control approaches: a dual spinner and a three-axis gyrostat. Unlike typical dual spinners, the purpose of MicroMAS 's 2U bus and spinner ...

Wise, Evan Dale

2013-01-01T23:59:59.000Z

38

UNIVERSITE JOSEPH FOURIER Ecole Doctorale : Electronique, Electrotechnique, Automatique et Traitement du Signal  

E-Print Network (OSTI)

MAS Multi-Agent System MCC Microgrid Central Controller MMN Modélisation Multi-Niveaux MPPT Maximum

Paris-Sud XI, Université de

39

Exhibition Hall Floor Plan  

Science Conference Proceedings (OSTI)

Jan 13, 2005 ... Industry. 645. FEI. Cytec. Industries. ENERGOPROM. MAS Inc. Parker ... STAS. Thermal. Ceramics. Thermcon. Ovens. Thorpe. Technologies.

40

A BRIEF OVERVIEW OF AURIGNACIAN CULTURES IN THE CONTEXT OF THE INDUSTRIES OF THE TRANSITION FROM THE MIDDLE TO THE UPPER PALEOLITHIC  

E-Print Network (OSTI)

. Garet; 20. Cazaubon (Drouilhet); 21. Gargas; 22. Les Abeilles; 23. Aurignac; 24. Tarté; 25. Mas d

Paris-Sud XI, Université de

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


41

A survey of security in multi-agent systems  

Science Conference Proceedings (OSTI)

Multi-agent systems (MAS) are a relatively new software paradigm that is being widely accepted in several application domains to address large and complex tasks. However, with the use of MAS in open, distributed and heterogeneous applications, the security ... Keywords: Agents, Multi-agent systems, Multi-agents, Security, Security in MAS

Rodolfo Carneiro Cavalcante; Ig Ibert Bittencourt; Alan Pedro da Silva; Marlos Silva; Evandro Costa; Robério Santos

2012-04-01T23:59:59.000Z

42

Special Report to Congress  

E-Print Network (OSTI)

in mineralized mounds at the seabed of Guay- mas Basin. Nature 295: 198­202. Slobodkin, A.I., Zavarzina, D

43

A Tractable Approach to Understanding the Results from Large-Scale 3D Transient  

E-Print Network (OSTI)

) problems or NASA's HPCC (High Performance Computing & Communication) grand challenges, can easily. Introduction Large-scale simulations of physical phenomena on high performance computing systems (often on mas

Peraire, Jaime

44

Blanchard Cr JohnsonGulch  

E-Print Network (OSTI)

Kintla Cr Lo gging Cr Anaconda Cr B owmanCr Kintla Cr Ca mas Cr Ana conda Cr SFkShortyCrShorty Cr Mc

45

Edward L. Lubbers4 , Peng W. Chee4  

E-Print Network (OSTI)

) Department of Field Crops, Vegetables and Genetics, Faculty of Agricultural, Food and Environmental Quality - MAS - abiotic stress - water-use efficiency - stable carbon isotope ratio/discrimination #12;

Chee, Peng W.

46

T-695: Avaya Aura Application Server Buffer Overflow in 'cstore...  

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

to 1.0.2 (MCP11.0.0.02011-01-07-1526 with MAS QFE patch: QFE-platform-6.0.244-0001.zip), or upgrade to MAS 2.0 with Patch Bundle 10 or later. Avaya strongly recommends that...

47

SOLID STATE NMR STUDY SUPPORTING THE LITHIUM VACANCY DEFECT MODEL IN CONGRUENT LITHIUM  

E-Print Network (OSTI)

@ Pergamon SOLID STATE NMR STUDY SUPPORTING THE LITHIUM VACANCY DEFECT MODEL IN CONGRUENT LITHIUM Nouember 1993; accepted I March 1994) Abstract-e3Nb and 7Li wideline- as well as MAS-NMR measurements were could be reduced to 0.6kHz by using MAS-NMR with a rotational lrequency of 4000Hz, thsre was no second 7

Bluemel, Janet

48

Multi-agent Infrastructure, Agent Discovery, Middle Agents for Web Services and Interoperation  

Science Conference Proceedings (OSTI)

This chapter has two parts. In Part I, we present an overview of issues in modeling Multi Agent Systems (MAS), discuss what features and components are required for a MAS infrastructure, and present a model of a generic infrastructure. In addition, we ...

Katia P. Sycara

2001-07-01T23:59:59.000Z

49

SAFARI 2000 MODIS Airborne Simulator Data  

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

Airborne Simulator Data Airborne Simulator Data The ORNL DAAC announces the release of a new SAFARI 2000 data set. The data set "SAFARI 2000 MODIS Airborne Simulator Data, Southern Africa, Dry Season 2000" contains MODIS Airborne Simulator (MAS) multispectral data collected during the SAFARI 2000 project. Twenty flights with the MAS instrument were undertaken over Southern Africa by the NASA ER-2 aircraft during August and September 2000. The MAS spectrometer collects 50 multispectral bands at 16-bit resolution with a ground resolution of 50 meters from 20,000 meters altitude and a cross track scan width of 85.92 degrees. This data set is organized by flight, and each flight consists of several straight-line segments called tracks. There is a MAS multispectral data file for each track. The data are available in Hierarchical Data Format

50

Fachbereich Physik an der TU Kaiserslautern | Hochschulranking auf ZEIT ONLINE http://ranking.zeit.de/che2012/de/fachbereich/400161?ab=3[30.04.2012 15:20:12  

E-Print Network (OSTI)

Physik (B), Physik (B.Ed.), Physik (M), Physik (M.Ed.) Chemie an der TU Kaiserslautern: Fachbereich Chemie Chemie (B), Chemie (B, LA), Chemie (M), Chemie (M, LA Gym), Chemie (Mas, LA Real plus) Mathematik

Pinnau, René

51

Development and validation of compressible mixture viscous fluid algorithm applied to predict the evolution of inertial fusion energy chamber gas and the impact of gas on direct-drive target survival  

E-Print Network (OSTI)

Symp. on Rarefied Gas Dyn. [51] R. Martin and F. Najmabadi.Direct Simulation”, R. Martin and F. Najmabadi, To AppearFluid Dynamics”, R. Martin, University of California Mas-

Martin, Robert Scott

2011-01-01T23:59:59.000Z

52

Figure 1 - TMS  

Science Conference Proceedings (OSTI)

The inset shows a detail of the major ampullate gland silk (MAS) fibers. The double fiber structure is known as a bave, and each individual monofilament is a brin ...

53

Lipid Dynamics and Protein–Lipid Interactions in 2D Crystals Formed with the ?-Barrel Integral Membrane Protein VDAC1  

E-Print Network (OSTI)

We employ a combination of [superscript 13]C/[superscript 15]N magic angle spinning (MAS) NMR and [superscript 2]H NMR to study the structural and functional consequences of different membrane environments on VDAC1 and, ...

Ong, Ta-Chung

54

Marilyn L. Dillon  

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

As Director of the Office of Resource Management and Planning, Ms. Dillon is responsible for managing the day-to-day operations of the Office of Management’s (MA’s) human resources,...

55

Ytinerario de la expedición de Juan de Oñate a Nuevo México 1597-1599  

E-Print Network (OSTI)

se descubrio nueue leguas haçia oriente la salina de granoa poblaçones por la parte del oriente hasta oy veynte detres leguas y mas hacia el oriente y mana de ojos de agua

Craddock, Jerry R.; De Marco, Barbara

2013-01-01T23:59:59.000Z

56

Cryogenic sample exchange NMR probe for magic angle spinning dynamic nuclear polarization  

E-Print Network (OSTI)

We describe a cryogenic sample exchange system that dramatically improves the efficiency of magic angle spinning (MAS) dynamic nuclear polarization (DNP) experiments by reducing the time required to change samples and by ...

Barnes, Alexander B.

57

María Inés Catalán: Catalán Family Farm  

E-Print Network (OSTI)

My son, you have to put compost on it, and dig more, and mixtheir bucket full of compost. We have furrows and furrowshijo tienes que ponerle compost, escarbar mas, revolver bien

Reti, Irene H.

2010-01-01T23:59:59.000Z

58

Muslim women in colonial North India circa 1920-1947 : politics, law and community identity  

E-Print Network (OSTI)

Studies, Cambridge EPW: Economic and Political Weekly ILR: Indian Law Reports ISR: Indian Social Reformer JUH: Jamiat-al-Ulama-i-Hind LAD: Legislative Assembly Debates (National Assembly) LWA: Lucknow Women's Association MAS: Modern Asian Studies...

Deutsch, Karin Anne

1998-10-27T23:59:59.000Z

59

Marilyn Dillon  

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

As Director of the Office of Resource Management and Planning, Ms. Dillon is responsible for managing the day-to-day operations of the Office of Management’s (MA’s) human resources,...

60

Electronic structure analyses and activation studies of a dinitrogen-derived terminal nitride of molybdenum  

E-Print Network (OSTI)

Chapter 1: Complexes obtained by electrophilic attack on a dinitrogen-derived terminal molybdenum nitride: Electronic structure analysis by solid state CP/MAS ¹?N NMR in combination ... Chapter 2. Carbene chemistry in the ...

Sceats, Emma Louise, 1978-

2004-01-01T23:59:59.000Z

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


61

Systems theory: melding the AI and simulation perspectives  

Science Conference Proceedings (OSTI)

The discipline of modelling and simulation (MaS) preceded artificial intelligence (AI) chronologically. Moreover, the workers in one area are typically unfamiliar with, and sometimes unsympathetic to, those in the other. One reason for this is that in ...

Norman Foo; Pavlos Peppas

2004-10-01T23:59:59.000Z

62

Applications of DNP and solid-state NMR for protein structure determination  

E-Print Network (OSTI)

Magic Angle Spinning (MAS) solid state nuclear magnetic resonance (SSNMR) is a developing method for determining the structures and studying the dynamics and functions of biological molecules. This method is particularly ...

Mayrhofer, Rebecca Maria

2010-01-01T23:59:59.000Z

63

Model-Free Volatility Prediction  

E-Print Network (OSTI)

How misleading can sample ACF’s of stable MA’s be? (Very! ).Series : YenDret Series : YenDret^2 Series : Wt9 ACFACF ACF Lag Lag Lag Figure 8: (Yen/Dollar example) (a)

Politis, Dimitris N.

2003-01-01T23:59:59.000Z

64

On Solving a Hard Quadratic 3-Dimensional Assignment Problem  

E-Print Network (OSTI)

School of Mathematical and Statistical Sciences, Arizona State University, Tempe , USA. E-mail: ...... Handbook of Constraint Programming, pp. 329–376. ... Rehn, T.: Fundamental permutation group algorithms for symmetry computation. Mas-.

65

table of contents  

Science Conference Proceedings (OSTI)

Thermochemical Modeling of Smelting Operations [pp. 309-321] A.L. Davies, J.F. Castle, P.J. Gabb, M.A.S. Siraa, J.A. Gisby and A.J. Weddick. Software for the ...

66

1H NMR Relaxation in Urea  

E-Print Network (OSTI)

Acetamide Studied by Deuterium NMR. J. Phys. Chem. 97 (1993)Duer. Solid state 13 C CP MAS NMR study of molecular motionsPulse and Fourier Transform NMR. Introduction to Theory and

Taylor, Robert E; Bacher, Alfred D; Dybowski, C.

2007-01-01T23:59:59.000Z

67

Structure and Dynamics of Cholesterol-Containing Polyunsaturated Lipid Membranes Studied by Neutron Diffraction and NMR  

E-Print Network (OSTI)

by Neutron Diffraction and NMR Mihaela Mihailescu • Olivierwas carried out by neutron diffraction, 2 H-NMR and 13C-MAS NMR. Scattering length distribution func- tions of

Mihailescu, Mihaela; Soubias, Olivier; Worcester, David; White, Stephen H.; Gawrisch, Klaus

2011-01-01T23:59:59.000Z

68

Fuzzy coalition formation among rational cooperative agents  

Science Conference Proceedings (OSTI)

Formation of coalitions in multi-agent systems (MAS) enables the development of efficient organizations. In the article, a model of fuzzy cooperative game with coalitions is described. It extends the model of the fuzzy coalition game with associated ...

Leonid B. Sheremetov; José C. Romero Cortés

2003-06-01T23:59:59.000Z

69

BWR Assembly Optimization for Minor Actinide Recycling  

Science Conference Proceedings (OSTI)

The Primary objective of the proposed project is to apply and extend the latest advancements in LWR fuel management optimization to the design of advanced boiling water reactor (BWR) fuel assemblies specifically for the recycling of minor actinides (MAs).

G. Ivan Maldonado; John M. Christenson; J.P. Renier; T.F. Marcille; J. Casal

2010-03-22T23:59:59.000Z

70

O-MaSE: a customisable approach to designing and building complex, adaptive multi-agent systems  

Science Conference Proceedings (OSTI)

The complexity and scope of software systems continues to grow. One approach to dealing with this growing complexity is the use of intelligent, multi-agent systems. However, due in part to its relative infancy when compared to other software paradigms, ... Keywords: adaptive MAS, agent-based systems, agent-oriented methodology, agents, complex MAS, integrated development environments, method engineering, multi-agent systems, software analysis, software design

Scott A. DeLoach; Juan Carlos Garcia-Ojeda

2010-11-01T23:59:59.000Z

71

High-pressure Magic Angle Spinning Nuclear Magnetic Resonance  

Science Conference Proceedings (OSTI)

A high-pressure magic angle spinning (MAS) NMR capability, consisting of a reusable high-pressure MAS rotor, a high-pressure loading/reaction chamber for in situ sealing and re-opening of the high-pressure MAS rotor, and a MAS probe with a localized RF coil for background signal suppression, is reported. The unusual technical challenges associated with development of a reusable high-pressure MAS rotor are addressed in part by modifying standard ceramics for the rotor sleeve to include micro-groves at the internal surface at both ends of the cylinder. In this way, not only is the advantage of ceramic cylinders for withstanding very high-pressure utilized, but also plastic bushings can be glued tightly in place so that other plastic sealing mechanisms/components and O-rings can be mounted to create the desired high-pressure seal. Using this strategy, sealed internal pressures exceeding 150 bars have been achieved and sustained under ambient external pressure with minimal penetration loss of pressure for 72 hours. As an application example, in situ 13C MAS NMR studies of mineral carbonation reaction intermediates and final products of forsterite (Mg2SiO4) reacted with supercritical CO2 and H2O at 150 bar and 50?C are reported, with relevance to geological sequestration of carbon dioxide.

Hoyt, David W.; Turcu, Romulus VF; Sears, Jesse A.; Rosso, Kevin M.; Burton, Sarah D.; Felmy, Andrew R.; Hu, Jian Z.

2011-10-01T23:59:59.000Z

72

Cepheid distances from infrared long-baseline interferometry - I. VINCI/VLTI observations of seven Galactic Cepheids  

E-Print Network (OSTI)

We report the angular diameter measurements of seven classical Cepheids (X Sgr, eta Aql, W Sgr, zeta Gem, beta Dor, Y Oph and L Car) that we have obtained with the VINCI instrument, installed at ESO's VLT Interferometer (VLTI). We also present reprocessed archive data obtained with the FLUOR/IOTA instrument on zeta Gem, in order to improve the phase coverage of our observations. We obtain average limb darkened angular diameter values of LD(X Sgr) = 1.471 +/- 0.033 mas, LD(eta Aql) = 1.839 +/- 0.028 mas, LD(W Sgr) = 1.312 +/- 0.029 mas, LD(beta Dor) = 1.891 +/- 0.024 mas, LD(zeta Gem) =1.747 +/- 0.061 mas, LD(Y Oph) = 1.437 +/- 0.040 mas and LD(L Car) = 2.988 +/- 0.012 mas. For four of these stars (eta Aql, W Sgr, beta Dor, and L Car) we detect the pulsational variation of their angular diameter. This enables us to compute directly their distances, using a modified version of the Baade-Wesselink method: d(eta Aql) = 276 [+55 -38] pc, d(W Sgr) = 379 [+216 -130] pc, d(beta Dor) = 345 [+175 -80] pc, d(L Car) = 603 [+24 -19] pc. The stated error bars are statistical in nature. Applying a hybrid method, that makes use of the Gieren et al. (1998) Period-Radius relation to estimate the linear diameters, we obtain the following distances (statistical and systematic error bars are mentioned): d(X Sgr) = 324 +/- 7 +/- 17 pc, d(eta Aql) = 264 +/- 4 +/- 14 pc, d(W Sgr) = 386 +/- 9 +/- 21 pc, d(beta Dor) = 326 +/- 4 +/- 19 pc, d(zeta Gem) = 360 +/- 13 +/- 22 pc, d(Y Oph) = 648 +/- 17 +/- 47 pc and d(L Car) = 542 +/- 2 +/- 49 pc.

P. Kervella; N. Nardetto; D. Bersier; D. Mourard; V. Coude du Foresto

2003-11-23T23:59:59.000Z

73

INTEGRATED CONTROL OF NEXT GENERATION POWER SYSTEM  

Science Conference Proceedings (OSTI)

Control methodologies provide the necessary data acquisition, analysis and corrective actions needed to maintain the state of an electric power system within acceptable operating limits. These methods are primarily software-based algorithms that are nonfunctional unless properly integrated with system data and the appropriate control devices. Components of the control of power systems today include protective relays, supervisory control and data acquisition (SCADA), distribution automation (DA), feeder automation, software agents, sensors, control devices and communications. Necessary corrective actions are still accomplished using large electromechanical devices such as vacuum, oil and gas-insulated breakers, capacitor banks, regulators, transformer tap changers, reclosers, generators, and more recently FACTS (flexible AC transmission system) devices. The recent evolution of multi-agent system (MAS) technologies has been reviewed and effort made to integrate MAS into next generation power systems. A MAS can be defined as ��a loosely-coupled network of problem solvers that work together to solve problems that are beyond their individual capabilities��. These problem solvers, often called agents, are autonomous and may be heterogeneous in nature. This project has shown that a MAS has significant advantages over a single, monolithic, centralized problem solver for next generation power systems. Various communication media are being used in the electric power system today, including copper, optical fiber and power line carrier (PLC) as well as wireless technologies. These technologies have enabled the deployment of substation automation (SA) at many facilities. Recently, carrier and wireless technologies have been developed and demonstrated on a pilot basis. Hence, efforts have been made by this project to penetrate these communication technologies as an infrastructure for next generation power systems. This project has thus pursued efforts to use specific MAS methods as well as pertinent communications protocols to imbed and assess such technologies in a real electric power distribution system, specifically the Circuit of the Future (CoF) developed by Southern California Edison (SCE). By modeling the behavior and communication for the components of a MAS, the operation and control of the power distribution circuit have been enhanced. The use of MAS to model and integrate a power distribution circuit offers a significantly different approach to the design of next generation power systems. For example, ways to control a power distribution circuit that includes a micro-grid while considering the impacts of thermal constraints, and integrating voltage control and renewable energy sources on the main power system have been pursued. Both computer simulations and laboratory testbeds have been used to demonstrate such technologies in electric power distribution systems. An economic assessment of MAS in electric power systems was also performed during this project. A report on the economic feasibility of MAS for electric power systems was prepared, and particularly discusses the feasibility of incorporating MAS in transmission and distribution (T&D) systems. Also, the commercial viability of deploying MAS in T&D systems has been assessed by developing an initial case study using utility input to estimate the benefits of deploying MAS. In summary, the MAS approach, which had previously been investigated with good success by APERC for naval shipboard applications, has now been applied with promising results for enhancing an electric power distribution circuit, such as the Circuit of the Future developed by Southern California Edison. The results for next generation power systems include better ability to reconfigure circuits, improve protection and enhance reliability.

None

2010-02-28T23:59:59.000Z

74

Facility Representative Program: Surveillance Guides  

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

Assessment Tools Assessment Tools CRADs Manager's Guide for Safety and Health Walkthroughs Surveillance Guides CMS 3.1 Configuration Management Implementation CMS 3.2 Change Control CMS 3.3 Verification of System Configuration and Operations CMS 3.4 Temporary Changes CPS 8.1 Hoisting and Rigging CPS 8.2 Trenching and Excavation EMS 21.1 Emergency Preparedness ENS 7.1 Definition of Design Requirements ERS 14.1 Satellite Accumulation Ares (RCRA Compliance) ERS 14.2 Emmissions Monitoring ERS 14.3 Underground and Above Ground Diesel Fuel Storage Tanks FPS 12.1 Life Safety FPS 12.2 Fire Protection and Prevention MAS 10.1 Maintenance Activities MAS 10.2 Control of Measuring and Test Equipment MAS 10.3 Seasonal Preparation MSS 1.1 Corrective Action/Issue Management NSS 18.1 Criticality Safety

75

Investigation of Mechanical Activation on Li-N-H Systems Using 6Li Magic Angle Spinning Nuclear Magnetic Resonance at Ultra-High Field  

SciTech Connect

Abstract The significantly enhanced spectral resolution in the 6Li MAS NMR spectra of Li-N-H systems at ultra-high field of 21.1 tesla is exploited, for the first time, to study the detailed electronic and chemical environmental changes associated with mechanical activation of Li-N-H system using high energy balling milling. Complementary to ultra-high field studies, the hydrogen discharge dynamics are investigated using variable temperature in situ 1H MAS NMR at 7.05 tesla field. The significantly enhanced spectral resolution using ultra-high filed of 21.1 tesla was demonstrated along with several major findings related to mechanical activation, including the upfield shift of the resonances in 6Li MAS spectra induced by ball milling, more efficient mechanical activation with ball milling at liquid nitrogen temperature than with ball milling at room temperature, and greatly enhanced hydrogen discharge exhibited by the liquid nitrogen ball milled samples.

Hu, Jian Zhi; Kwak, Ja Hun; Yang, Zhenguo; Osborn, William; Markmaitree, Tippawan; Shaw, Leonard D.

2008-07-15T23:59:59.000Z

76

A Large Sample Volume Magic Angle Spinning Nuclear Magnetic Resonance Probe for In-Situ Investigations with Constant Flow of Reactants  

SciTech Connect

A large-sample-volume constant-flow magic angle sample spinning (CF-MAS) NMR probe is reported for in-situ studies of the reaction dynamics, stable intermediates/transition states, and mechanisms of catalytic reactions. In our approach, the reactants are introduced into the catalyst bed using a fixed tube at one end of the MAS rotor while a second fixed tube, linked to a vacuum pump, is attached at the other end of the rotor. The pressure difference between both ends of the catalyst bed inside the sample cell space forces the reactants flowing through the catalyst bed, which improves the diffusion of the reactants and products. This design allows the use of a large sample volume for enhanced sensitivity and thus permitting in-situ 13C CF-MAS studies at natural abundance. As an example of application, we show that reactants, products and reaction transition states associated with the 2-butanol dehydration reaction over a mesoporous silicalite supported heteropoly acid catalyst (HPA/meso-silicalite-1) can all be detected in a single 13C CF-MAS NMR spectrum at natural abundance. Coke products can also be detected at natural 13C abundance and under the stopped flow condition. Furthermore, 1H CF-MAS NMR is used to identify the surface functional groups of HPA/meso-silicalite-1 under the condition of in-situ drying . We also show that the reaction dynamics of 2-butanol dehydration using HPA/meso-silicalite-1 as a catalyst can be explored using 1H CF-MAS NMR.

Hu, Jian Z.; Sears, Jesse A.; Mehta, Hardeep S.; Ford, Joseph J.; Kwak, Ja Hun; Zhu, Kake; Wang, Yong; Liu, Jun; Hoyt, David W.; Peden, Charles HF

2012-02-21T23:59:59.000Z

77

Honeywell Modular Automation System Computer Software Documentation  

SciTech Connect

The purpose of this Computer Software Document (CSWD) is to provide configuration control of the Honeywell Modular Automation System (MAS) in use at the Plutonium Finishing Plant (PFP). This CSWD describes hardware and PFP developed software for control of stabilization furnaces. The Honeywell software can generate configuration reports for the developed control software. These reports are described in the following section and are attached as addendum's. This plan applies to PFP Engineering Manager, Thermal Stabilization Cognizant Engineers, and the Shift Technical Advisors responsible for the Honeywell MAS software/hardware and administration of the Honeywell System.

STUBBS, A.M.

2000-12-04T23:59:59.000Z

78

Agent-based intelligent system development for decision support in chemical process industry  

Science Conference Proceedings (OSTI)

This paper presents an agent-based intelligent system to support coordinate manufacturing execution and decision-making in chemical process industry. A multi-agent system (MAS) framework is developed to provide a flexible infrastructure for the integration ... Keywords: Artificial intelligence, Coordinate manufacturing, Decision support, Information integration, Multi-agent system

Ying Gao; Zhigang Shang; Antonis Kokossis

2009-10-01T23:59:59.000Z

79

Feedback mechanisms between water availability and water use in a semi-arid river basin: A spatially explicit multi-agent simulation approach  

Science Conference Proceedings (OSTI)

Understanding the processes responsible for the distribution of water availability over space and time is of great importance to spatial planning in a semi-arid river basin. In this study the usefulness of a multi-agent simulation (MAS) approach for ... Keywords: Brazil, Irrigation, Multi-agent simulation, River basin, Semi-arid, Water availability

Pieter R. van Oel; Maarten S. Krol; Arjen Y. Hoekstra; Renzo R. Taddei

2010-04-01T23:59:59.000Z

80

Direct patterning of surface quantum wells with an atomic force J. Cortes Rosa, M. Wendel, H. Lorenz,a)  

E-Print Network (OSTI)

Direct patterning of surface quantum wells with an atomic force microscope J. Cortes Rosa, MAs­AlSb surface quantum wells. Sharp and sturdy electron beam deposited tips are developed to withstand the comparatively high N forces in the direct patterning process. By direct patterning the InAs surface quantum well

Ludwig-Maximilians-Universität, München

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


81

Genet. Sel. Evol. 37 (Suppl. 1) (2005) S109S123 S109 c INRA, EDP Sciences, 2004  

E-Print Network (OSTI)

of the local breeds for milk yield and composition within their specific area and production system [2 and natural mating plays an important role in reproduction; and (ii) the individual recording of any trait- assisted selection (MAS) or gene-assisted selection (GAS), either to speed up selection of routinely

Recanati, Catherine

82

Self-organization in multi-agent systems  

Science Conference Proceedings (OSTI)

This paper is the synthesis of joint work realised in a technical forum group within the AgentLink III NoE framework, which elaborated on issues concerning self-organization and emergence in multi-agent systems (MAS). The work concluded on a common definition ...

Giovanna Di Marzo Serugendo; Marie-Pierre Gleizes; Anthony Karageorgos

2005-06-01T23:59:59.000Z

83

IN SITU MAGIC ANGLE SPINNING NMR FOR STUDYING GEOLOGICAL CO(2) SEQUESTRATION  

Science Conference Proceedings (OSTI)

Geological carbon sequestration (GCS) is one of the most promising ways of mitigating atmospheric greenhouse gases (1-3). Mineral carbonation reactions are potentially important to the long-term sealing effectiveness of caprock but remain poorly predictable, particularly in low-water supercritical CO2 (scCO2)-dominated environments where the chemistry has not been adequately explored. In situ probes that provide molecular-level information is desirable for investigating mechanisms and rates of GCS mineral carbonation reactions. MAS-NMR is a powerful tool for obtaining detailed molecular structure and dynamics information of a system regardless whether the system is in a solid, a liquid, a gaseous, or a supercritical state, or a mixture thereof (4,5). However, MAS NMR under scCO2 conditions has never been realized due to the tremendous technical difficulties of achieving and maintaining high pressure within a fast spinning MAS rotor (6,7), where non-metal materials must be used. In this work, we report development of a unique high pressure MAS NMR capability, and its application to mineral carbonation chemistry in scCO2 under geologically relevant temperatures and pressures.

Hoyt, David W.; Turcu, Romulus VF; Sears, Jesse A.; Rosso, Kevin M.; Burton, Sarah D.; Kwak, Ja Hun; Felmy, Andrew R.; Hu, Jian Z.

2011-03-27T23:59:59.000Z

84

mxxx005-mxxx055-2013-07-09.dvi  

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

REFID20126 LANG 79 PR D19 956 C.B. Lang, A. Mas-Parareda (GRAZ) REFID21661 MARTIN 78C ANP 114 1 A.D. Martin, M.R. Pennington (CERN) REFID21465 COSTA... 77B PL 71B 345 B. Costa...

85

m065.dvi  

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

(MPIM, CERN, ZEEM, CRAC) LANG 79 PR D19 956 C.B. Lang, A. Mas-Parareda (GRAZ) MARTIN 78C ANP 114 1 A.D. Martin, M.R. Pennington (CERN) COSTA... 77B PL 71B 345 B. Costa de...

86

Un nouveau TCL pour les oprateurs de covariance dans le modle ARH(1).  

E-Print Network (OSTI)

Un nouveau TCL pour les opérateurs de covariance dans le modèle ARH(1). André MAS Université, nous donnons des conditions su¢ santes pour l'obtention du TCL pour la suite des opérateurs de

Mas, André

87

ccsd00001714, Nonlinear dynamics of electromagnetic pulses in cold relativistic plasmas  

E-Print Network (OSTI)

ccsd­00001714, version 2 ­ 19 Oct 2004 Nonlinear dynamics of electromagnetic pulses in cold particle and photon accel- eration, nonlinear optics, laser fusion, and others [1{6]. Intense of coupled electromagnetic and electrostatic modes in cold relativistic electron-ion plas- mas to conclude

88

Intelligent agents for QoS management  

Science Conference Proceedings (OSTI)

This paper addresses the structural and behavioral characteristics of multi-agent system (MAS) for Quality of Service (QoS) management using MESSAGE (Methodology for Engineering Systems of Software Agents) modeling language that extends UML (Unified ... Keywords: MESSAGE/UML, QoS management, intelligent agents

Krunoslav Trzec; Darko Huljenic

2002-07-01T23:59:59.000Z

89

Negative ion density fronts* Igor Kaganovich,a)  

E-Print Network (OSTI)

group of the pe- riodic table. Historically, processes in electronegative EN plasmas have attracted considerable attention in connection with problems of atmospheric electricity. Interest in EN plas- mas has and deposition rate can be maintained despite the lower av- erage power.7 Recently, it has been recognized

Kaganovich, Igor

90

Systematic verification of multi-agent systems based on rigorous executable specifications  

Science Conference Proceedings (OSTI)

The multi-agent paradigm provides abstractions that facilitate the design of complex systems consisting of heterogeneous, autonomous components. Most methodologies focus on the specification of complex agent interactions using the social system metaphor, ... Keywords: MAS, agent-based systems, agent-oriented software engineering, agents, executable specifications, formal verification, model checking, multi-agent systems, simulation

Holger Giese; Florian Klein

2007-04-01T23:59:59.000Z

91

Office of Radiation & Indoor Air EPA 402-R-05-009 Radiation Protection Division (6608J) August 2006  

E-Print Network (OSTI)

of wastes from abandoned uranium mines in the western United States. Between the 1940s and 1990s, thousands.......................................21 Figure 3. Density of Western Uranium Mines Using the MAS/MILS Database Portion of the Uranium of uranium mines operated in the United States, mostly in the western continental U.S., leaving a legacy

92

RAPPORT ANNUEL RAPPORT ANNUEL  

E-Print Network (OSTI)

point de logiciels et de schémas de calcul pour le Advanced Candu Reactor (ACR), un réacteur nucléaire réacteurs CANDU actuels. La présence simultané d'eau légère et d'eau lourde crée des effects de spectres (en

93

L'Institut de Gnie Nuclaire de l'cole Polytechnique a obtenue une importante subvention de recherche, en partenariat avec l'Atomic Energy of Canada Limited  

E-Print Network (OSTI)

point de logiciels et de schémas de calcul pour le Advanced Candu Reactor (ACR), un réacteur nucléaire réacteurs CANDU actuels. La présence simultané d'eau légère et d'eau lourde crée des effects de spectres (en

Meunier, Michel

94

Local agent-based self-stabilisation in global resource utilisation  

Science Conference Proceedings (OSTI)

Distributed management of complex large-scale infrastructures, such as power distribution systems, is challenging. Sustainability of these systems can be achieved by enabling stabilisation in global resource utilisation. This paper proposes the Energy ... Keywords: MAS, adaptation, agent-based systems, distributed management, energy management, large-scale infrastructures, multi-agent systems, power distribution, resource utilisation, software agents, stabilisation, thermostatic devices, tree overlay

Evangelos Pournaras; Martijn Warnier; Frances M. T. Brazier

2010-12-01T23:59:59.000Z

95

Emissions of Criteria Pollutants, Toxic Air Pollutants, and Greenhouse Gases, From the Use of Alternative Transportation Modes and Fuels  

E-Print Network (OSTI)

for Vehicles Running of E85,” Addendum: Tenth internationalPM tire-weard N2O exhausta CH4 exhausta LPG CNG E85 M85LPG CNG E85 M85 LPG input mass inpu mas Notes: see next

Delucchi, Mark

1996-01-01T23:59:59.000Z

96

Practical and theoretical innovations in multi-agent systems research  

Science Conference Proceedings (OSTI)

1 IntroductionUKMAS has now been running for six years, in 1996 and 1997 under the heading of FoMAS (Foundations of Multi-Agent Systems) both organised by Michael Luck at Warwick University and then subsequently in its current incarnation, UKMAS, ...

Mark D'inverno; Michael Luck; Ukmas Ukmas

2002-09-01T23:59:59.000Z

97

A review of the applications of agent technology in traffic and transportation systems  

Science Conference Proceedings (OSTI)

The agent computing paradigm is rapidly emerging as one of the powerful technologies for the development of largescale distributed systems to deal with the uncertainty in a dynamic environment. The domain of traffic and transportation systems is well ... Keywords: agents, intelligent transportation systems (ITS), mobile agent systems, multiagent systems (MAS)

Bo Chen; Harry H. Cheng

2010-06-01T23:59:59.000Z

98

Roberts Environmental CenterClaremont McKenna College J. Emil Morhardt  

E-Print Network (OSTI)

para la zona marítima de explotación petrolera de PEMEX Modelos Climáticos: Dr. Julián Adem, M. en C Asistencia de mas de 30 académicos, estudiantes y funcionarios, personal de IMTA, CFE, PEMEX, SMN, CONAGUA

Morhardt, Emil

99

Academic Program Review Self-Study Report  

E-Print Network (OSTI)

para la zona marítima de explotación petrolera de PEMEX Modelos Climáticos: Dr. Julián Adem, M. en C Asistencia de mas de 30 académicos, estudiantes y funcionarios, personal de IMTA, CFE, PEMEX, SMN, CONAGUA

100

Reflecting on ontologies: towards ontology-based agent-oriented software engineering  

Science Conference Proceedings (OSTI)

"Ontology" in association with "software engineering" is becoming commonplace. This paper argues for the need to place ontologies at the centre of the software development lifecycle for multi agent systems to enhance reuse of software workproducts as ... Keywords: agents, multi agent systems (MAS), ontologies, services, software development lifecycle (SDLC)

Ghassan Beydoun; Brian Henderson-Sellers; Jun Shen; Graham Low

2009-12-01T23:59:59.000Z

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


101

Agent-based evolutionary optimisation of trading strategies  

Science Conference Proceedings (OSTI)

The backtesting and optimisation of trading strategies has emerged as an interesting research and experimental problem in both finance and Information Technology (IT) fields. However, it is a non-trivial task to effectively and efficiently ... Keywords: GAs, MAS, agent-based systems, agents, data mining, genetic algorithms, multi-agent systems, optimisation, stock data, trading strategies

Jiarui Ni; Dan Luo; Yuming Ou; Chao Luo

2008-02-01T23:59:59.000Z

102

Controlling teams of uninhabited air vehicles  

Science Conference Proceedings (OSTI)

We describe a Multi-Agent System (MAS) for controlling teams of uninhabited air vehicles (UAVs) in the context of a larger system that has been used to evaluate potential concepts of use and technologies. The approach is one of a decision-making partnership ... Keywords: human-machine partnership, multi-agent system, uninhabited air vehicles, variable autonomy

Jeremy W. Baxter; Graham S. Horn

2005-07-01T23:59:59.000Z

103

MALEF: Framework for distributed machine learning and data mining  

Science Conference Proceedings (OSTI)

Growing importance of distributed data mining techniques has recently attracted attention of researchers in multiagent domain. In this paper we present a novel framework MultiAgent Learning Framework (MALEF) designed for both the agent-based ... Keywords: MAS, agent-based systems, architectures, data mining, distributed machine learning, market-based approaches, multi-agent systems, multiagent learning frameworks, unsupervised clustering

Jan Tozicka; Michael Rovatsos; Michal Pechoucek; Stepan Urban

2008-02-01T23:59:59.000Z

104

In Situ NMR Analysis of Fluids Contained in Sedimentary Rock Thomas M. de Swiet,* Marco Tomaselli,* Martin D. Hurlimann, and Alexander Pines*  

E-Print Network (OSTI)

In Situ NMR Analysis of Fluids Contained in Sedimentary Rock Thomas M. de Swiet,* Marco Tomaselli of pore fluids may be obtained in situ by magic angle spinning (MAS) nuclear magnetic resonance (NMR), which is normally used for solid samples. 1 H MAS­NMR spectra of water and crude oil in Berea sandstone

Pines, Alexander

105

Mobility of organic pollutants in soil components. What role can magic angle spinning NMR play?  

E-Print Network (OSTI)

Mobility of organic pollutants in soil components. What role can magic angle spinning NMR play? C resonance (NMR) spectroscopy on dry samples. We recently demonstrated the potential of the 1 H high resolution magic angle spinning (MAS) NMR technique to study such mechanisms in situ on highly hydrated

Paris-Sud XI, Université de

106

Honeywell Modular Automation System Computer Software Documentation  

Science Conference Proceedings (OSTI)

This document provides a Computer Software Documentation for a new Honeywell Modular Automation System (MAS) being installed in the Plutonium Finishing Plant (PFP). This system will be used to control new thermal stabilization furnaces in HA-211 and vertical denitration calciner in HC-230C-2.

CUNNINGHAM, L.T.

1999-09-27T23:59:59.000Z

107

Multi Agent System based fault location and isolation in a smart microgrid system  

Science Conference Proceedings (OSTI)

In this paper, a Multi Agent System (MAS) based on sequence current magnitudes and current direction is proposed for fault location and isolation in a smart microgrid system. Each of the fault types has a different impact on the sequence current components, ...

Seetaram Alwala; Ali Feliachi; M. A. Choudhry

2012-01-01T23:59:59.000Z

108

Fire performance of single leaf masonry walls  

Science Conference Proceedings (OSTI)

A finite element model called MasSET has been developed which is capable of predicting the structural behaviour of single leaf masonry walls subject to elevated temperatures. The analysis models a slice through the wall as a column strip in plane stress, ... Keywords: boundary conditions, eccentricity, finite element model, masonry in fire, slenderness ratio

A. Nadjai; M. O'Gara; F. Ali

2001-09-01T23:59:59.000Z

109

Agent-based social networking for mobile user  

Science Conference Proceedings (OSTI)

Nowadays, social network services play an important role in users' everyday lives. This is especially emphasised in lives of users that belong to Generation Y. Young people often communicate and share various personal information with their family, ... Keywords: MAS, agent-based systems, agents, m-users, mobile networks, mobile users, multi-agent systems, social networking, social networks, software agents

Rebeka Belavic; Marko Basuga; Vedran Podobnik; Ana Petric; Ignac Lovrek

2010-11-01T23:59:59.000Z

110

Public Transport Dispatch and Decision Support System Based on Multi-Agent  

Science Conference Proceedings (OSTI)

In order to raise the level of automatization and intelligentization of urban public transport management, regarding the research and current status on application of urban public transport dispatch system as well as the weakness of it, from decision ... Keywords: Decision Support System (DSS), Multi-Agent System(MAS), Urban Public Transport Dispatch System

Zengzhen He; Qisen Zhang

2009-10-01T23:59:59.000Z

111

U.S. Department of Energy Categorical Exclusion ...  

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

Steam Line Segment Savannah River Site AikenAikenSouth Carolina Dismantle and removal (D&R) of out-of-service steam lines from K-Area to L-Area and C-Area to the X-mas tree on...

112

27Al and 1H Solid State NMR Studies Show Evidence of TiAl3 and TiH2 in Ti-doped NaAlH4  

DOE Green Energy (OSTI)

Previous X-ray Diffraction (XRD) and Nuclear Magnetic Resonance (NMR) studies on Ti-doped NaAlH{sub 4} revealed the reaction products of two heavily doped (33.3 at.%) samples that were solvent-mixed and mechanically-milled. This investigation revealed that nano-crystalline or amorphous Al{sub 2}O{sub 3} forms from the possible coordination of aluminum with oxygen atom of the furan ring system from added tetrahydrofuran (THF) in the solvent-mixed sample, and that TiAl{sub 3} forms in mechanically-milled samples. The present paper provides a more sophisticated NMR investigation of the these materials. On heavily doped (33.3 at.%) solvent-mixed samples, {sup 27}Al Magic Angle Spinning (MAS) NMR {sup 27}Al multiple quantum MAS (MQMAS) indicates the presence of an oxide layer of Al{sub 2}O{sub 3} on the surfaces of potentially bulk nanocrystalline Ti, nanocrystalline TiAl{sub 3}, and/or metallic aluminum. The {sup 1}H MAS NMR data also indicate the possible coordination of aluminum with the oxygen atom in the THF. On heavily doped samples that were mechanically milled, {sup 27}Al MAS NMR and static NMR confirms the presence of TiAl{sub 3}. In addition, the {sup 1}H MAS NMR and {sup 1}H spin-lattice relaxation (T{sub 1}) measurements are consistent with the presence of TiH{sub 2}. These results are in agreement with recent XAFS measurements indicating both Al and H within the first few coordination shells of Ti in the doped alanate.

Herberg, J; Maxwell, R; Majzoub, E

2005-05-26T23:59:59.000Z

113

Putting Science to Work BUILDING NANOTECHNOLOGY DEVELOPMENT  

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

BUILDING BUILDING NANOTECHNOLOGY DEVELOPMENT THOM MAsON NAMED ORNL DiRECTOR Accompanying Congressman Wamp (at lectern) during the grant announcement are, from left, Oak Ridge City Councilwoman Lou Dunlap; Tom Ballard, ORNL director of Economic Development and Partnerships; and Gerald Boyd, manager, DOE Oak Ridge Office. THOM MAsON NAMED ORNL DiRECTOR T hom Mason has been named ORNL's new direc- tor, effective July 1. The choice was announced in late May by UT-Battelle Board of Governors Chair Carl Kohrt and Vice Chair John Petersen. Mason's most recent role has been associate labora- tory director for Neutron Sciences. As head of the Spallation Neutron Source project, he led a consortium of six DOE labs in the design and construction of the $1.4 billion neutron accelerator. Completed on time,

114

Page not found | Department of Energy  

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

41 - 12850 of 28,905 results. 41 - 12850 of 28,905 results. Download Small Modular Reactors and U.S. Clean Energy Sources for Electricity For the clean energy goal to be met, then, the non-carbon emitting sources must provide some 2900 TWhr. Hydropower is generally assumed to have reached a maximum of 250 TWhr, so if we assume... http://energy.gov/ne/downloads/small-modular-reactors-and-us-clean-energy-sources-electricity Download MAS 10.1 Implementation of the Integrated Safety Management System (ISMS) Process in Maintenance Activities, 2/14/2000 The objective of this surveillance is to evaluate the effectiveness of the contractor's ISMS process with regard to maintenance activities. Surveillance activities encompass work planning and... http://energy.gov/hss/downloads/mas-101-implementation-integrated-safety-management-system-isms

115

Page not found | Department of Energy  

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

Error message Error message The page you requested does not exist. For your convenience, a search was performed using the query Flash2009 19. You are here Home » Page not found Page not found Oops! The page you are looking for doesn't seem to be available. Did you find a broken link? Tell us and we'll fix it. Or maybe you meant to go somewhere else? Use the search box or links below to help guide you. Enter terms Flash2009 19 Search Showing 2661 - 2670 of 9,640 results. Download MAS 10.2 Control of Measuring and Test Equipment, 3/9/95 The objective of this surveillance is to verify that the contractor maintains adequate control of tools, gauges, instruments, devices or systems used to inspect, test, calibrate, measure or... http://energy.gov/hss/downloads/mas-102-control-measuring-and-test-equipment-3995

116

A Sentinel Approach to Fault Handling in Multi-Agent Systems  

E-Print Network (OSTI)

Fault handling in Multi-Agent Systems (MAS) is not much addressed in current research. Normally, it is considered difficult to address in detail and often well covered by traditional methods, relying on the underlying communication and operating system. In this paper it is shown that this is not necessarily true, at least not with the assumptions on applications we have made. These assumptions are a massive distribution of computing components, a heterogeneous underlying infrastructure (in terms of hardware, software and communication methods), an emerging configuration, possibly different parties in control of sub-systems, and real-time demands in parts of the system. The key problem is that while a MAS is modular and therefore should be a good platform for building fault tolerant systems, it is also non-deterministic, making it difficult to guarantee a specific behaviour, especially in fault situations. Our proposal is to introduce sentinels to guard certain functionality and to pro...

Staffan Hgg Department; Staffan Hägg

1996-01-01T23:59:59.000Z

117

Solid-State NMR Studies of Fossil Fuels using One- and Two-Dimensional Methods at High Magnetic Field  

Science Conference Proceedings (OSTI)

We examine the opportunities offered by advancements in solid-state NMR (SSNMR) methods, which increasingly rely on the use of high magnetic fields and fast magic angle spinning (MAS), in the studies of coals and other carbonaceous materials. The sensitivity of one- and two-dimensional experiments tested on several Argonne Premium coal samples is only slightly lower than that of traditional experiments performed at low magnetic fields in large MAS rotors, since higher receptivity per spin and the use of 1H detection of low-gamma nuclei can make up for most of the signal loss due to the small rotor size. The advantages of modern SSNMR methodology in these studies include improved resolution, simplicity of pulse sequences, and the possibility of using J-coupling during mixing.

Althaus, Stacey M.; Mao, Kanmi; Kennedy, Gordon J.; Pruski, Marek

2012-06-24T23:59:59.000Z

118

The Marketing Style of Advisory Services for Corn and Soybeans  

E-Print Network (OSTI)

The advisory service marketing recommendations used in this research represent the best efforts of the AgMAS Project staff to accurately and fairly interpret the information made available by each advisory program. In cases where a recommendation is vague or unclear, some judgment is exercised as to whether or not to include that particular recommendation or how to implement the recommendation. Given that some recommendations are subject to interpretation, the possibility is acknowledged that the AgMAS track record of recommendations for a given program may differ from that stated by the advisory service, or from that recorded by another subscriber. In addition, the net advisory prices presented in this report may differ substantially from those

Roberto Bertoli; Carl R. Zuluaf; Scott H. Irwin; Thomas E. Jackson; Darrel L. Good; The Marketing; Style Advisory; Services Corn; Soybeans In; Roberto Bertoli; Carl R. Zuluaf; Scott H. Irwin; Thomas E. Jackson; Darrel L. Good

1999-01-01T23:59:59.000Z

119

Honeywell modular automation system computer software documentation  

SciTech Connect

The purpose of this Computer Software Document (CSWD) is to provide configuration control of the Honeywell Modular Automation System (MAS) in use at the Plutonium Finishing Plant (PFP). The Honeywell MAS is used to control the thermal stabilization furnaces in glovebox HA-211. The PFP developed software is being updated to reflect the Polycube Processing and Unwashed Salt Thermal Stabilization program addition. The polycube processing program was installed per HNF-FMP-02-11162-R2. The functional test of the program was performed in JCS work package 22-02-1031, The unwashed salt item program was installed per HNF-FMP-03-16577-RO. The functional test of the program completed in JCS work package 22-03-00654.

STUBBS, A.M.

2003-07-02T23:59:59.000Z

120

VLBI AND ARCHIVAL VLA AND WSRT OBSERVATIONS OF THE GRB 030329 RADIO AFTERGLOW  

SciTech Connect

We present VLBI and archival Karl G. Jansky Very Large Array (VLA) and Westerbork Synthesis Radio Telescope (WSRT) observations of the radio afterglow from the gamma-ray burst (GRB) of 2003 March 29 (GRB 030329) taken between 672 and 2032 days after the burst. The VLA and WSRT data suggest a simple power-law decay in the flux at 5 GHz, with no clear signature of any rebrightening from the counterjet. We report an unresolved source at day 2032 of size 1.18 {+-} 0.13 mas, which we use in conjunction with the expansion rate of the burst to argue for the presence of a uniform, interstellar-medium-like circumburst medium. A limit of <0.067 mas yr{sup -1} is placed on the proper motion, supporting the standard afterglow model for gamma-ray bursts.

Mesler, Robert A.; Pihlstroem, Ylva M.; Taylor, Greg B. [Department of Physics and Astronomy, University of New Mexico, MSC07 4220, Albuquerque, NM 87131 (United States); Granot, Johnathan, E-mail: meslerra@unm.edu [Centre for Astrophysics Research, Science and Technology Research Institute, University of Hertfordshire, College Lane, Hatfield AL10 9AB (United Kingdom)

2012-11-01T23:59:59.000Z

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121

Page not found | Department of Energy  

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

81 - 29390 of 31,917 results. 81 - 29390 of 31,917 results. Article Summary of Decisions- June 10, 2013- June 14, 2013 Decisions were issued on: - Freedom of Information Act Appeal - Personnel Security (10 CFR Part 710) http://energy.gov/oha/articles/summary-decisions-june-10-2013-june-14-2013 Download MAS 10.1 Implementation of the Integrated Safety Management System (ISMS) Process in Maintenance Activities, 2/14/2000 The objective of this surveillance is to evaluate the effectiveness of the contractor's ISMS process with regard to maintenance activities. Surveillance activities encompass work planning and... http://energy.gov/hss/downloads/mas-101-implementation-integrated-safety-management-system-isms Download OPS 9.5 Control of On-Shift Training 3/14/01 The objective of this surveillance is to verify that on-shift training is

122

Integrating the Havana agent platform into the existing web infrastructure  

Science Conference Proceedings (OSTI)

Mobile software agents represent an ideal mechanism for dealing with information overload and disconnected computing. Currently, however, they are not integrated into the existing web infrastructure and therefore no websites are agent-enabled. Two ... Keywords: MAS, agent gateway, agent integration, agent-based systems, business incentives, disconnected computing, information overload, internet, mobile agents, multi-agent systems, security, software agents, web agents, web infrastructure

Qusay H. Mahmoud; Leslie Yu

2010-10-01T23:59:59.000Z

123

N: 2009 ENAM XXXX Arts et Mtiers ParisTech -Centre de Paris  

E-Print Network (OSTI)

puissance cinétique (kW) en entrée d'une turbine en fonction de son diamètre (m) et pour différentes / DCNS................................. 25 Figure 1.1.1.S : Schémas de principe d'un propulseur POD)......................................................................... 45 Figure 1.2.1.C : Turbine permettant de capter l'énergie cinétique des courants (Source Verdant

Paris-Sud XI, Université de

124

Formulating mixed models for experiments, including longitudinal experiments  

E-Print Network (OSTI)

americano D.K. Ludwig, que tinha como objetivo a produção de celulose em larga escala, dando início, assim, permitiram à empresa não somente conquistar um lugar estável no mercado internacional de celulose, mas também Para, Agènce d'Elevage de l'Etat du Pará AMCEL, Amapá Celulose Ltda. (entreprise de production de

Brien, Chris

125

Analytical inference model for prediction and customization of inter-agent dependency requirements  

Science Conference Proceedings (OSTI)

Inter-agent communication is one of the main concerns of Agent Oriented Requirements Engineering (AORE). The concern is delineated as managing inter-dependencies and interaction among various agents performing collaborative activities. To carry out cooperative ... Keywords: adaptive neuro fuzzy inference system (ANFIS), analytical inference model (AIM), degree of dependency (DoD), mamdani fuzzy inference system (MFIS), multi-agent system (MAS), sugeno fuzzy inference system (SFIS)

Vibha Gaur; Anuja Soni

2012-04-01T23:59:59.000Z

126

Modelling and simulation of social systems with INGENIAS  

Science Conference Proceedings (OSTI)

Most agent-based simulation toolkits are based on the Java programming language. This makes their use difficult for social scientists, who are usually not skilled in computer programming. However, agent modelling concepts are not unlike those which ... Keywords: ABM, IDK, INGENIAS development kit, MAS, agent development tools, agent-based modelling, agent-based simulation, agent-based systems, model transformation, model-driven development, multi-agent systems, social models, social science, social simulation, social systems

Juan Pavon; Candelaria Sansores; Jorge J. Gomez-Sanz

2008-02-01T23:59:59.000Z

127

Minor Actinides Loading Optimization for Proliferation Resistant Fuel Design - BWR  

Science Conference Proceedings (OSTI)

One approach to address the United States Nuclear Power (NP) 2010 program for the advanced light water reactor (LWR) (Gen-III+) intermediate-term spent fuel disposal need is to reduce spent fuel storage volume while enhancing proliferation resistance. One proposed solution includes increasing burnup of the discharged spent fuel and mixing minor actinide (MA) transuranic nuclides (237Np and 241Am) in the high burnup fuel. Thus, we can reduce the spent fuel volume while increasing the proliferation resistance by increasing the isotopic ratio of 238Pu/Pu. For future advanced nuclear systems, MAs are viewed more as a resource to be recycled, and transmuted to less hazardous and possibly more useful forms, rather than simply disposed of as a waste stream in an expensive repository facility. MAs play a much larger part in the design of advanced systems and fuel cycles, not only as additional sources of useful energy, but also as direct contributors to the reactivity control of the systems into which they are incorporated. A typical boiling water reactor (BWR) fuel unit lattice cell model with UO2 fuel pins will be used to investigate the effectiveness of adding MAs (237Np and/or 241Am) to enhance proliferation resistance and improve fuel cycle performance for the intermediate-term goal of future nuclear energy systems. However, adding MAs will increase plutonium production in the discharged spent fuel. In this work, the Monte-Carlo coupling with ORIGEN-2.2 (MCWO) method was used to optimize the MA loading in the UO2 fuel such that the discharged spent fuel demonstrates enhanced proliferation resistance, while minimizing plutonium production. The axial averaged MA transmutation characteristics at different burnup were compared and their impact on neutronics criticality and the ratio of 238Pu/Pu discussed.

G. S. Chang; Hongbin Zhang

2009-09-01T23:59:59.000Z

128

Nature of X-shaped sources  

E-Print Network (OSTI)

The nature of X-shaped sources is a matter of considerable debate: it has even been proposed that they provide evidence for black hole mergers$ / $spin reorientation, and therefore constrain the rate of strong gravitational wave events (Merritt & Ekers 2002). Based on morphological and spectral characteristics of these sources, currently a strong contender to explain the nature of these sources is the `alternative' model of Lal & Rao (2007), in which these sources consist of two pairs of jets, which are associated with two unresolved AGNs. Detailed morphological and spectral results on milliarcsecond-scales (mas) provide a crucial test of this model, and hence these sources are excellent candidates to study on mas; {\\it i.e.}, to detect he presence/absence of double nuclei/AGNs, signs of helical/disrupted jets, thereby, to investigate spatially resolved/unresolved binary AGN systems and providing clues to understanding the physics of merging of AGNs on mas. We conducted a systematic study of a large s...

Lal, D V; Kraft, R P; Cheung, C C; Lobanov, A P; Zensus, J A; Bhatnagar, S; Rao, A P

2009-01-01T23:59:59.000Z

129

The Formaldehyde Masers in NGC 7538 and G29.96-0.02: VLBA, MERLIN, and VLA Observations  

E-Print Network (OSTI)

The 6 cm formaldehyde (H2CO) maser sources in the compact HII regions NGC 7538-IRS1 and G29.96-0.02 have been imaged at high resolution (beams < 50 mas). Using the VLBA and MERLIN, we find the angular sizes of the NGC 7538 masers to be ~10 mas (30 AU) corresponding to brightness temperatures ~10^8 K. The angular sizes of the G29.96-0.02 masers are ~20 mas (130 AU) corresponding to brightness temperatures ~10^7 K. Using the VLA, we detect 2 cm formaldehyde absorption from the maser regions. We detect no emission in the 2 cm line, indicating the lack of a 2 cm maser and placing limits on the 6 cm excitation process. We find that both NGC 7538 maser components show an increase in intensity on 5-10 year timescales while the G29.96-0.02 masers show no variability over 2 years. A search for polarization provides 3-sigma upper limits of 1% circularly polarized and 10% linearly polarized emission in NGC 7538 and of 15% circularly polarized emission in G29.96-0.02. A pronounced velocity gradient of 28 km/s/arcsecon...

Hoffman, I M; Palmer, P; Richards, A M S; Hoffman, Ian M.; Palmer, Patrick

2003-01-01T23:59:59.000Z

130

Design of a telescope-occulter system for THEIA  

E-Print Network (OSTI)

The Telescope for Habitable Exoplanets and Interstellar/Intergalactic Astronomy (THEIA) is a mission concept study for a flagship-class telescope-occulter system to search for terrestrial planets and perform general astrophysics with a space-based 4m telescope. A number of design options were considered for the occulter and telescope optical systems; in this paper we discuss the design of occulters and coronagraphs for THEIA and examine their merits. We present two optimized occulters: a 25.6m-radius occulter with 19m petals that achieves 10^-12 suppression from 250-1000nm with a 75mas inner working angle, and a 20.0m-radius occulter with 10m petals that achieves 10^-12 suppression from 250-700nm with a 75mas inner working angle. For more widely separated planets (IWA > 108mas), this second occulter is designed to operate at a second closer distance where it provides 10^-12 suppression from 700-1000nm. We have also explored occulter/coronagraph hybrid systems, and found that an AIC coronagraph that exploits t...

Cady, Eric; Dumont, Philip; Egerman, Robert; Kasdin, N Jeremy; Linfield, Roger; Lisman, Doug; Savransky, Dmitry; Seager, Sara; Shaklan, Stuart; Spergel, David; Tenerelli, Domenick; Vanderbei, Robert

2009-01-01T23:59:59.000Z

131

A catalog of bright calibrator stars for 200-meter baseline near-infrared stellar interferometry  

E-Print Network (OSTI)

We present in this paper a catalog of reference stars suitable for calibrating infrared interferometric observations. In the K band, visibilities can be calibrated with a precision of 1% on baselines up to 200 meters for the whole sky, and up to 300 meters for some part of the sky. This work, extending to longer baselines a previous catalog compiled by Borde et al. (2002), is particularly well adapted to hectometric-class interferometers such as the Very Large Telescope Interferometer (VLTI, Glindemann et al. 2003) or the CHARA array (ten Brummelaar et al. 2003) when observing well resolved, high surface brightness objects (K<8). We use the absolute spectro-photometric calibration method introduced by Cohen et al. (1999) to derive the angular diameters of our new set of 948 G8--M0 calibrator stars extracted from IRAS, 2MASS and MSX catalogs. Angular stellar diameters range from 0.6 mas to 1.8 mas (median is 1.1 mas) with a median precision of 1.35%. For both the northern and southern hemispheres, the closest calibrator star is always less than 10 degree away.

A. Merand; P. Borde; V. Coude du Foresto

2004-12-10T23:59:59.000Z

132

EVOLUTION OF THE WATER MASER EXPANDING SHELL IN W75N VLA 2  

Science Conference Proceedings (OSTI)

We present Very Long Baseline Interferometry (VLBI) observations of 22 GHz H{sub 2}O masers in the high-mass star-forming region of W75N, carried out with VLBI Exploration of Radio Astrometry (VERA) for three epochs in 2007 with an angular resolution of {approx}1 mas. We detected H{sub 2}O maser emission toward the radio jet in VLA 1 and the expanding shell-like structure in VLA 2. The spatial distribution of the H{sub 2}O masers detected with VERA and measured proper motions around VLA 1 and VLA 2 are similar to those found with previous VLBI observations in epochs 1999 and 2005, with the masers in VLA 1 mainly distributed along a linear structure parallel to the radio jet and, on the other hand, forming a shell-like structure around VLA 2. We have made elliptical fits to the VLA 2 H{sub 2}O maser shell-like structure observed in the different epochs (1999, 2005, and 2007), and found that the shell is still expanding eight years after its discovery. From the difference in the size of the semi-major axes of the fitted ellipses in epochs 1999 ({approx_equal}71 {+-} 1 mas), 2005 ({approx_equal}97 {+-} 3 mas), and 2007 ({approx_equal}111 {+-} 1 mas), we estimate an average expanding velocity of {approx}5 mas yr{sup -1}, similar to the proper motions measured in the individual H{sub 2}O maser features. A kinematic age of {approx}20 yr is derived for this structure. In addition, our VERA observations indicate an increase in the ellipticity of the expanding shell around VLA 2 from epochs 1999 to 2007. In fact, the elliptical fit of the VERA data shows a ratio of the minor and major axes of {approx}0.6, in contrast with an almost circular shape for the shell detected in 1999 and 2005 (b/a {approx} 0.9). This suggests that we are probably observing the formation of a jet-driven H{sub 2}O maser structure in VLA2, evolving from a non-collimated pulsed-outflow event during the first stages of evolution of a massive young stellar object (YSO). This may support predictions made earlier by other authors on this issue, consistent with recent magnetohydrodynamical simulations. We discuss possible implications of our results in the study of the first stages of evolution of massive YSOs.

Kim, Jeong-Sook; Kim, Sang Joon [School of Space Science, Kyunghee University, Seocheon-dong, Giheung-si, Gyeonggi-do, 446-701 (Korea, Republic of)] [School of Space Science, Kyunghee University, Seocheon-dong, Giheung-si, Gyeonggi-do, 446-701 (Korea, Republic of); Kim, Soon-Wook [Korea Astronomy and Space Science Institute, 776 Daedeokdaero, Yuseong, Daejeon 305-348 (Korea, Republic of)] [Korea Astronomy and Space Science Institute, 776 Daedeokdaero, Yuseong, Daejeon 305-348 (Korea, Republic of); Kurayama, Tomoharu [Graduate School of Science and Engineering, Kagoshima University, 1-21-35 Korimoto, Kagoshima, Kagoshima 890-0065 (Japan)] [Graduate School of Science and Engineering, Kagoshima University, 1-21-35 Korimoto, Kagoshima, Kagoshima 890-0065 (Japan); Honma, Mareki [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)] [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Sasao, Tesuo [Yaeyama Star Club, Ookawa, Ishigaki, Okinawa 904-0022 (Japan)] [Yaeyama Star Club, Ookawa, Ishigaki, Okinawa 904-0022 (Japan); Surcis, Gabriele [Joint Institute for VLBI in Europe, Postbus 2, 7990 AA Dwingeloo (Netherlands)] [Joint Institute for VLBI in Europe, Postbus 2, 7990 AA Dwingeloo (Netherlands); Canto, Jorge [Instituto de Astronomia (UNAM), Apartado 70-264, 04510 Mexico D. F. (Mexico)] [Instituto de Astronomia (UNAM), Apartado 70-264, 04510 Mexico D. F. (Mexico); Torrelles, Jose M., E-mail: evony@kasi.re.kr, E-mail: skim@kasi.re.kr [Instituto de Ciencias del Espacio (CSIC)-UB/IEEC, Universitat de Barcelona, Marti i Franques 1, E-08028 Barcelona (Spain)

2013-04-10T23:59:59.000Z

133

Feasibility of an image planning system for kilovoltage image-guided radiation therapy  

SciTech Connect

Purpose: Image guidance has become a standard of care for many treatment scenarios in radiation therapy. This is most typically accomplished by use of kV x-ray devices mounted onto the linear accelerator (Linac) gantry that yield planar, fluoroscopic, and cone-beam computed tomography (CBCT) images. Image acquisition parameters are chosen via preset techniques that rely on broad categorizations in patient anatomy and imaging goal. However, the optimal imaging technique results in detectability of the features of interest while exposing the patient to minimum dose. Herein, the authors present an investigation into the feasibility of developing an image planning system (IPS) for radiotherapy.Methods: In this first phase, the authors focused on developing an algorithm to predict tissue contrast produced by a common radiotherapy planar imaging chain. Input parameters include a CT dataset and simulated planar imaging technique settings that include kV and mAs. Energy-specific attenuation through each voxel of the CT dataset was calculated in the algorithm to derive a net transmitted intensity. The response of the flat panel detector was integrated into the image simulation algorithm. Verification was conducted by comparing simulated and measured images using four phantoms. Comparisons were made in both high and low contrast settings, as well as changes in the geometric appearance due to image saturation. Results: The authors studied a lung nodule test object to assess the planning system's ability to predict object contrast and detectability. Verification demonstrated that the slope of the pixel intensities is similar, the presence of the nodule is evident, and image saturation at high mAs values is evident in both images. The appearance of the lung nodule is a function of the image detector saturation. The authors assessed the dimensions of the lung nodule in measured and simulated images. Good quantitative agreement affirmed the algorithm's predictive capabilities. The invariance of contrast with kVp and mAs prior to saturation was predicted, as well as the gradual loss of object detectability as saturation was approached. Small changes in soft tissue density were studied using a mammography step wedge phantom. Data were acquired at beam qualities of 80 and 120 kVp and over exposure values ranging from 0.04 to 500 mAs. The data showed good agreement in terms of the absolute value of pixel intensities predicted, as well as small variations across the step wedge pattern. The saturation pixel intensity was consistent between the two beam qualities studied. Boney tissue contrast was assessed using two abdominal phantoms. Measured and calculated values agree in terms of predicting the mAs value at which detector saturation, and subsequent loss of contrast occurs. The lack of variation in contrast over mAs values lower than 10 suggests that there is wide latitude for minimizing patient dose. Conclusions: The authors developed and tested an algorithm that can be used to assist in kV imaging technique selection during localization for radiotherapy. Phantom testing demonstrated the algorithm's predictive accuracy for both low and high contrast imaging scenarios. Detector saturation with subsequent loss of imaging detail, both in terms of object size and contrast were accurately predicted by the algorithm.

Thapa, Bishnu B.; Molloy, Janelle A. [Department of Radiation Medicine, University of Kentucky, Lexington, Kentucky 40536-0293 (United States)

2013-06-15T23:59:59.000Z

134

Received; accepted To be published in The Astrophysical Journal – 2 –  

E-Print Network (OSTI)

We have used the NRAO Very Long Baseline Array (VLBA) to image OH(1720 MHz) masers in the supernova remnants W28 and W44 at a resolution of 40 mas. We also used MERLIN to observe the same OH(1720 MHz) masers in W44 at a resolution of 290 × 165 mas. All the masers are resolved by these VLBA and MERLIN observations. The measured sizes range from 50 to 180 mas and yield brightness temperature estimates from 0.3-20×108 K. We investigate whether these measured angular sizes are intrinsic and hence originate as a result of the physical conditions in the supernova remnant shock, or whether they are scatter broadened sizes produced by the turbulent ionized gas along the line of sight. While the current data on the temporal and angular broadening of pulsars, masers and extragalactic sources toward W44 and W28 can be understood in terms of scattering, we cannot rule out that these large sizes are intrinsic. Recent theoretical modeling by Lockett et al. suggests that the physical parameters in the shocked region are indicative of densities and OH abundances which lead to estimates of sizes as large as what we measure. If the sizes and structure are intrinsic, then the OH(1720 MHz) masers may be more like the OH(1612 MHz) masers in circumstellar shells than OH masers associated with H II regions. At two locations in W28 we observe the classical S-shapes in the Stokes V profiles caused by Zeeman splitting and use it to infer magnetic fields of order 2 milliGauss. Subject headings: masers — ISM: supernova remnants — scattering – 3 – 1.

M. J Claussen; W. M. Goss; D. A. Frail; K. Desai

1999-01-01T23:59:59.000Z

135

Rotor Design for High Pressure Magic Angle Spinning Nuclear Magnetic Resonance  

Science Conference Proceedings (OSTI)

High pressure magic angle spinning (MAS) nuclear magnetic resonance (NMR) with a sample spinning rate exceeding 2.1 kHz and pressure greater than 165 bar has never been realized. In this work, a new sample cell design is reported, suitable for constructing cells of different sizes. Using a 7.5 mm high pressure MAS rotor as an example, internal pressure as high as 200 bar at a sample spinning rate of 6 kHz is achieved. The new high pressure MAS rotor is re-usable and compatible with most commercial NMR set-ups, exhibiting low 1H and 13C NMR background and offering maximal NMR sensitivity. As an example of its many possible applications, this new capability is applied to determine reaction products associated with the carbonation reaction of a natural mineral, antigorite ((Mg,Fe2+)3Si2O5(OH)4), in contact with liquid water in water-saturated supercritical CO2 (scCO2) at 150 bar and 50 ?C. This mineral is relevant to the deep geologic disposal of CO2, but its iron content results in too many sample spinning sidebands at low spinning rate. Hence, this chemical system is a good case study to demonstrate the utility of the higher sample spinning rates that can be achieved by our new rotor design. We expect this new capability will be useful for exploring solid-state, including interfacial, chemistry at new levels of high-pressure in a wide variety of fields.

Turcu, Romulus VF; Hoyt, David W.; Rosso, Kevin M.; Sears, Jesse A.; Loring, John S.; Felmy, Andrew R.; Hu, Jian Z.

2013-01-01T23:59:59.000Z

136

Participatory Simulation for Collective Management of Protected Areas for Biodiversity Conservation and Social Inclusion  

E-Print Network (OSTI)

Abstract — In this paper, we introduce a research project aimed at methodological and computer-based support for participatory management of protected areas, in order to promote biodiversity conservation and social inclusion. Our starting point is the “companion modelling ” approach, as defined by the ComMod group, a movement of researchers created in 2003. Their method, called MAS/RPG, consists in iterations coupling role-playing games (RPG) and agent-based simulations (MAS), in order to model collective management and support negotiation between stakeholders. It has been applied to the collective management of natural renewable resources. The agent-based simulations are used to foresee, display and discuss the impact of individual actions on the environment. For obvious reasons, companion modelling does not provide stakeholders with a pre-defined solution to their conflicts. More recently, an evolution of the MAS/RPG approach named “agent-based participatory simulations ” proved able to prompt participants to create innovative distributed solutions to complex problems. These simulations rely more heavily on computer support (distribution, logs, assistant agents) and integrate the agent-based simulation with the role-playing game, thus reducing the need for iterations. Our objective is to propose and evaluate the use of this methodology and the associated software tools on different national parks for conservation of natural resources in Brazil. Our first case study is the Tijuca National Park, in Rio de Janeiro. It is inserted in the urban net of a great metropolis (Rio de Janeiro) and suffers from different kinds of human pressure and their impacts, e.g., illegal occupation, water contamination and social tension. This case study addresses the question of conflict resolution, one of the key questions for the participatory management of protected areas.

Jean-pierre Briot

2007-01-01T23:59:59.000Z

137

Revue d’Etudes Tibétaines  

E-Print Network (OSTI)

- yang gtan la mi pheb pas / ‘jal byed mtha’ drug tshul bzhi’i sgo nas rtogs par bya ste / : “ Ainsi, les tantra non communs [qui doivent être l’]objet d’une compréhension exacte (gzhal bya), les ågama, les préceptes et les tantra secrets [dont l... : “objet épistémologique” (tshad mas rtogs par bya ba) (v. Krang dbyi sun, et alii (1985) : Bod rgya tshig mdzod chen mo , Mi rigs dpe skrun khang, DZA-AH, p. 2416) ; on pourrait com- prendre aussi, ”objet d’une réalisation véritable”. 17 V. supra, n. 16...

Achard, Jean-Luc

2002-01-01T23:59:59.000Z

138

Institutions and Cross-border Mergers and Acquisitions (M&A) Value Creation  

E-Print Network (OSTI)

Cross-border Merger and Acquisitions (M&As) are an increasingly important strategy adopted by firms in order to create value in fiercely competitive global markets. Cross-border M&A value creation, that is, wealth creation for shareholders from cross-border M&As, is therefore of considerable theoretical and practical importance. However, our understanding of the sources of cross-border M&A value creation remains limited. Researchers have found that the most commonly researched variables have little effect on cross-border M&A value creation. We therefore still do not understand the processes behind cross-border M&As. In this is dissertation I examine the main effects of host country regulatory, economic and physical infrastructure institutions on cross-border M&A value creation. I further examine the moderating effects of host country political institutions on the relationship between host country regulatory institutions and cross-border M&A value creation. Moreover, I investigate the effects of institutional distance between host and home country on cross-border M&A value creation. I argue that the effects of institutional distance (regulatory and economic distance) on cross-border M&A value creation are not symmetric, but rather the effects are contingent upon the direction of the distance. My hypotheses are tested on a sample of 6141 cross-border M&As between 1995 and 2003. Results of this analysis show that acquirers are more likely to create value by acquiring targets in countries with less advanced regulatory institutions. Further, my results indicate that host country political institutions positively moderate the relationship between host country regulatory institutions and cross-border M&A value creation. Host country economic institutions have an inverted U-shaped relationship with cross-border M&A value creation, and host country physical infrastructure institutions have a positive relationship with cross-border M&A value creation. Additionally, results show that there is an inverted U-shaped relationship between institutional distance and cross-border M&A value creation. The findings suggest that the effects of regulatory and economic institutional distance on cross-border M&A value creation are not symmetric. The effects are contingent upon the direction of the distance. That is whether the level of host country institutions is higher or lower than that of home country institutions. Implications for management and public policy are discussed.

Zhu, Hong

2008-12-01T23:59:59.000Z

139

URAT: astrometric requirements and design history  

E-Print Network (OSTI)

The U.S. Naval Observatory Robotic Astrometric Telescope (URAT) project aims at a highly accurate (5 mas), ground-based, all-sky survey. Requirements are presented for the optics and telescope for this 0.85 m aperture, 4.5 degree diameter field-of-view, specialized instrument, which are close to the capability of the industry. The history of the design process is presented as well as astrometric performance evaluations of the toleranced, optical design, with expected wavefront errors included.

N. Zacharias; U. Laux; A. Rakich; H. Epps

2006-06-08T23:59:59.000Z

140

Modlisation du comportement des neutrons dans un racteur avanc canadien ACR en utilisant les logiciels dvelopps  

E-Print Network (OSTI)

Limited (AECL), portant sur la mise au point de logiciels et de schémas de calcul pour le Advanced Candu des ACR est différente de celle des réacteurs CANDU actuels. La présence simultanée d'eau légère et d des réacteurs CANDU actuels devra être modifiée et améliorée avant de s'adapter au ACR. Nous devrons

Meunier, Michel

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141

2 Large-Scale Data Sets  

E-Print Network (OSTI)

help in preparing this material. Computational Science ? Use of computer simulation as a tool for greater understanding of the real world – Complements experimentation and theory ? Problems are increasingly computationally challenging – Large parallel machines needed to perform calculations – Critical to leverage parallelism in all phases ? Data access is a huge challenge – Using parallelism to obtain performance – Finding usable, efficient, portable interfaces – Understanding and tuning I/O IBM BG/L system. Visualization of entropy in Terascale Supernova Initiative application. Image from Kwan-Liu Ma’s visualization team at UC Davis. Argonne National

Rob Ross; Thanks To Rob Latham; Rajeev Thakur; Marc Unangst; Brent Welch For Their

2009-01-01T23:59:59.000Z

142

PROCESSING METHOD EFFECT ON SUN DIAMETER MEASUREMENT WITH CCD SOLAR ASTROLABE  

Science Conference Proceedings (OSTI)

Photometric Sun diameter measurement is based on the calculation of the inflection point of the solar limb. In ground measurement, this point is located at a position on the solar limb where the signal-to-noise ratio is very high, which necessitates the appropriate filtering techniques to eliminate the noise while preserving its position. In this paper, we compare the filtering method currently in use to process the CCD solar astrolabe data, the FFTD method widely used, with a different method that we propose. Using the acquired data from the CCD astrolabe at Calern, France during 1997, we can obtain a mean difference of 130 mas in the measured radii.

Djafer, Djelloul [Unite de Recherche Appliquee en Energies Renouvelables, BP 88, Ghardaiea (Algeria); Irbah, Abdenour, E-mail: djdjafer@gmail.com, E-mail: abdenour.irbah@latmos.ipsl.fr [Laboratoire Atmospheres, Milieux, Observations Spatiales (LATMOS), CNRS UMR8190, Universite Paris VI, Pierre et Marie Curie, Universite de Versailles Saint-Quentin-en-Yvelines INSU, 78280 Guyancourt (France)

2012-05-01T23:59:59.000Z

143

Wanzek Construction | Open Energy Information  

Open Energy Info (EERE)

Wanzek Construction Wanzek Construction Jump to: navigation, search Logo: Wanzek Construction Name Wanzek Construction Address 2028 2nd Avenue NW Place West Fargo, ND Zip 58078 Country United States Sector Geothermal energy, Renewable Energy, Solar, Wind energy Product Turnkey Construction Services Stock Symbol MTZ Year founded 1971 Number of employees 1100 Company Type For Profit Company Ownership Public Small Business No Minority Business Yes Affiliated Companies MasTec N.A; MasTec Renewables; Phone number 2816064172 Website http://www.wanzek.com Coordinates 29.78577°, -95.66735° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":29.78577,"lon":-95.66735,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

144

M.A. Silva Dias,  

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

1 a 260. 1 a 260. 1 Modelando o Impacto Climático Regional e Remoto do Desmatamento M.A. Silva Dias, 1 R. Avissar, 2 e P. Silva Dias 1,3 As observações e os modelos concordam que os níveis atuais e os padrões de desmatamento da Amazônia de fato intensificam as transferências de massa e energia entre a terra e a atmosfera por meio da criação de circulações impulsionadas termicamente com efeitos significativos sobre a precipitação, mas que variam sazonal e regionalmente. Isso também indicou a necessidade de identificar o limiar onde o aumento do desmatamento realmente implica a diminuição de pluviosidade, conforme apontado pela maioria dos modelos de circulação geral de baixa resolução. Grande parte dos estudos sobre o impacto remoto ainda é exploratória, mas indicam que

145

Regeneração de Floresta Secundária Eric A. Davidson Woods Hole Research Center, Falmouth, Massachusetts, USA  

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

299 a 309. 299 a 309. 1 Limitações de Nutrientes para a Regeneração de Floresta Secundária Eric A. Davidson Woods Hole Research Center, Falmouth, Massachusetts, USA Luiz A. Martinelli CENA, Universidade de São Paulo, Piracicaba, Brasil Os solos antigos, altamente intemperizados, de florestas de planície na Bacia Amazônica em geral mostram ciclos conservativos de P e ciclos "frouxos" de N. Essa generalização se aplica às florestas maduras, mas a aceleração da mudança no uso da terra está alterando as paisagens da Amazônia. Aproximadamente 16% da área original de floresta foram desmatados e cerca de 160.000 km 2 são cobertos por vegetação secundária. As florestas secundárias são comuns nas regiões agrícolas, mas poucas permanecem por muito mais de

146

The mid-infrared diameter of W Hydrae  

E-Print Network (OSTI)

Mid-infrared (8-13 microns) interferometric data of W Hya were obtained with MIDI/VLTI between April 2007 and September 2009, covering nearly three pulsation cycles. The spectrally dispersed visibility data of all 75 observations were analyzed by fitting a circular fully limb-darkened disk (FDD) model to all data and individual pulsation phases. Asymmetries were studied with an elliptical FDD. Modeling results in an apparent angular FDD diameter of W Hya of about (80 +/- 1.2) mas (7.8 AU) between 8 and 10 microns, which corresponds to an about 1.9 times larger diameter than the photospheric one. The diameter gradually increases up to (105 +/- 1.2) mas (10.3 AU) at 12 microns. In contrast, the FDD relative flux fraction decreases from (0.85 +/- 0.02) to (0.77 +/- 0.02), reflecting the increased flux contribution from a fully resolved surrounding silicate dust shell. The asymmetric character of the extended structure could be confirmed. An elliptical FDD yields a position angle of (11 +/- 20) deg and an axis ra...

Zhao-Geisler, R; Koehler, R; Lopez, B; Leinert, C

2011-01-01T23:59:59.000Z

147

Candidate stellar occultations by large trans-neptunian objects up to 2015  

E-Print Network (OSTI)

We study large trans-neptunian objects (TNOs) using stellar occultations. We derive precise astrometric predictions for stellar occultations by Eris, Haumea, Ixion, Makemake, Orcus, Quaoar, Sedna, Varuna, 2002 TX300, and 2003 AZ84 for 2011-2015. We construct local astrometric catalogs of stars in the UCAC2 (Second US Naval Observatory CCD Astrograph Catalog) frame covering the sky path of these objects. For that purpose, during 2007-2009, we carried out an observational program at the ESO2p2/WFI (2.2 m Max-Planck ESO telescope with the Wide Field Imager) instrument. Astrometric catalogs with proper motions were produced for each TNO, containing more than 5.35 million stars covering the sky paths with 30' width in declination. The magnitude completeness is about R = 19 with a limit of about R = 21. We predicted 2717 stellar occultation candidates for all targets. Ephemeris offsets with about from 50 mas to 100 mas precision were applied to each TNO orbit to improve the predictions. They were obtained during 20...

Assafin, M; Martins, R Vieira; Braga-Ribas, F; Sicardy, B; Andrei, A H; Neto, D N da Silva

2012-01-01T23:59:59.000Z

148

OH 12.8-0.9: A New Water-Fountain Source  

E-Print Network (OSTI)

We present observational evidence that the OH/IR star OH 12.8-0.9 is the fourth in a class of objects previously dubbed "water-fountain" sources. Using the Very Long Baseline Array, we produced the first images of the water maser emission associated with OH 12.8-0.9. We find that the masers are located in two compact regions with an angular separation of ~109 mas on the sky. The axis of separation between the two maser regions is at a position angle of 1.5 deg. East of North with the blue-shifted (-80.5 to -85.5 km/s) masers located to the North and the red-shifted (-32.0 to -35.5 km/s) masers to the South. In addition, we find that the blue- and red-shifted masers are distributed along arc-like structures ~10-12 mas across oriented roughly perpendicular to the separation axis. The morphology exhibited by the water masers is suggestive of an axisymmetric wind with the masers tracing bow shocks formed as the wind impacts the ambient medium. This bipolar jet-like structure is typical of the three other confirmed water-fountain sources. When combined with the previously observed spectral characteristics of OH 12.8-0.9, the observed spatio-kinematic structure of the water masers provides strong evidence that OH 12.8-0.9 is indeed a member of the water-fountain class.

D. A. Boboltz; K. B. Marvel

2005-05-31T23:59:59.000Z

149

THE SOLAR NEIGHBORHOOD. XXVI. AP Col: THE CLOSEST (8.4 pc) PRE-MAIN-SEQUENCE STAR  

Science Conference Proceedings (OSTI)

We present the results of a multi-technique investigation of the M4.5Ve flare star AP Col, which we discover to be the nearest pre-main-sequence star. These include astrometric data from the CTIO 0.9 m, from which we derive a proper motion of 342.0 {+-} 0.5 mas yr{sup -1}, a trigonometric parallax of 119.21 {+-} 0.98 mas (8.39 {+-} 0.07 pc), and photometry and photometric variability at optical wavelengths. We also provide spectroscopic data, including radial velocity (22.4 {+-} 0.3 km s{sup -1}), lithium equivalent width (EW) (0.28 {+-} 0.02 A), H{alpha} EW (-6.0 to -35 A), vsin i (11 {+-} 1 km s{sup -1}), and gravity indicators from the Siding Spring 2.3 m WiFeS, Lick 3 m Hamilton echelle, and Keck-I HIRES echelle spectrographs. The combined observations demonstrate that AP Col is the closer of only two known systems within 10 pc of the Sun younger than 100 Myr. Given its space motion and apparent age of 12-50 Myr, AP Col is likely a member of the recently proposed {approx}40 Myr old Argus/IC 2391 Association.

Riedel, Adric R.; Henry, Todd J.; Jao, Wei-Chun [Department of Physics and Astronomy, Georgia State University, Atlanta, GA 30302-4106 (United States); Murphy, Simon J. [Research School of Astronomy and Astrophysics, The Australian National University, Cotter Road, Weston Creek, ACT 2611 (Australia); Melis, Carl [Center for Astrophysics and Space Sciences, University of California, San Diego, CA 92093-0424 (United States); Subasavage, John P., E-mail: riedel@chara.gsu.edu, E-mail: thenry@chara.gsu.edu, E-mail: jao@chara.gsu.edu, E-mail: murphysj@mso.anu.edu.au, E-mail: cmelis@ucsd.edu, E-mail: jsubasavage@ctio.noao.edu [Cerro Tololo Inter-American Observatory, La Serena (Chile)

2011-10-15T23:59:59.000Z

150

VERY LONG BASELINE ARRAY ASTROMETRIC OBSERVATIONS OF THE CASSINI SPACECRAFT AT SATURN  

Science Conference Proceedings (OSTI)

The planetary ephemeris is an essential tool for interplanetary spacecraft navigation, studies of solar system dynamics (including, for example, barycenter corrections for pulsar timing ephemerides), the prediction of occultations, and tests of general relativity. We are carrying out a series of astrometric very long baseline interferometry observations of the Cassini spacecraft currently in orbit around Saturn, using the Very Long Baseline Array (VLBA). These observations provide positions for the center of mass of Saturn in the International Celestial Reference Frame (ICRF) with accuracies {approx}0.3 mas (1.5 nrad) or about 2 km at the average distance of Saturn. This paper reports results from eight observing epochs between 2006 October and 2009 April. These data are combined with two VLBA observations by other investigators in 2004 and a Cassini-based gravitational deflection measurement by Fomalont et al. in 2009 to constrain a new ephemeris (DE 422). The DE 422 post-fit residuals for Saturn with respect to the VLBA data are generally 0.2 mas, but additional observations are needed to improve the positions of all of our phase reference sources to this level. Over time we expect to be able to improve the accuracy of all three coordinates in the Saturn ephemeris (latitude, longitude, and range) by a factor of at least three. This will represent a significant improvement not just in the Saturn ephemeris but also in the link between the inner and outer solar system ephemerides and in the link to the inertial ICRF.

Jones, Dayton L.; Folkner, William M.; Lanyi, Gabor; Border, James; Jacobson, Robert A. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Fomalont, Ed [National Radio Astronomy Observatory, Charlottesville, VA 22903 (United States); Dhawan, Vivek; Romney, Jon, E-mail: dayton.jones@jpl.nasa.gov [National Radio Astronomy Observatory, Socorro, NM 87801 (United States)

2011-02-15T23:59:59.000Z

151

ON THE DETECTABILITY OF A PREDICTED MESOLENSING EVENT ASSOCIATED WITH THE HIGH PROPER MOTION STAR VB 10  

Science Conference Proceedings (OSTI)

Extrapolation of the astrometric motion of the nearby low-mass star VB 10 indicates that sometime in late 2011 December or during the first 2-3 months of 2012, the star will make a close approach to a background point source. Based on astrometric uncertainties, we estimate a 1 in 2 chance that the distance of closest approach {rho}{sub min} will be less than 100 mas, a 1 in 5 chance that {rho}{sub min} light from the background source and an astrometric shift of 3.3 mas. The lensing signal will however be significantly diluted by the light from VB 10, which is 1.5 mag brighter than the background source in B band, 5 mag brighter in I band, and 10 mag brighter in K band, making the event undetectable in all but the bluer optical bands. However, we show that if VB 10 happens to harbor a {approx}1 M{sub J} planet on a moderately wide ( Almost-Equal-To 0.18 AU-0.84 AU) orbit, there is a chance (1% to more than 10%, depending on the distance of closest approach and orbital period and inclination) that a passage of the planet closer to the background source will result in a secondary event of higher magnification. The detection of secondary events could be made possible with a several-times-per-night multi-site monitoring campaign.

Lepine, Sebastien [Department of Astrophysics, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024 (United States); DiStefano, Rosanne, E-mail: lepine@amnh.org, E-mail: rd@cfa.harvard.edu [Harvard Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

2012-04-10T23:59:59.000Z

152

Image Quality and Radiation Dose Assessment of a Digital Mammography System  

Science Conference Proceedings (OSTI)

Image quality and radiation dose of a direct amorphous selenium digital mammography system were considered in terms of contrast to noise ratio (CNR) and average glandular dose (AGD). They were measured for various qualities and breast phantom thicknesses with different types of breast tissue composition to determine optimal radiation quality and dose. Three sets of breast tissue equivalent slabs (30%:70%, 50%:50% and 70%:30% glandular-adipose) with thickness of 2 cm to 7 cm and 0.2 mm aluminum foil were used to provide certain CNR. Two different combinations of anode/ilter material and a wide range of tube voltages were employed for each phantom thickness. Phantom images with grid were acquired using automatic exposure control (AEC) mode for each thickness. Phantom images without grid were also obtained in manual exposure mode by selecting the same anode/filter combination and kVp as the image obtained with grid at the same thickness, but varying mAs of 10 to 200 mAs. Optimization indicated that relatively high energy beam qualities should be used with a greater dose to compensate for lower energy x-rays. The results also indicate that current AEC setting for a fixed detector is not optimal.

Isa, N. M.; Hassan, W. M. S. W. [Department of Physics, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Abdullah, W. A. K. W. [Department of Radiology, Hospital USM, 16150 Kubang Kerian, Kelantan (Malaysia); Othman, F. [Department of Diagnostic Imaging, Hospital Putrajaya, Pres, 62250 Putrajaya, Walayah Persekutuan (Malaysia); Ramli, A. A. M. [Malaysian Nuclear Agency, 43000 Kajang, Selangor (Malaysia)

2010-07-07T23:59:59.000Z

153

ON THE CONSTANCY OF THE SOLAR RADIUS. III  

Science Conference Proceedings (OSTI)

The Michelson Doppler Imager on board the Solar and Heliospheric Observatory satellite has operated for over a sunspot cycle. This instrument is now relatively well understood and provides a nearly continuous record of the solar radius in combination with previously developed algorithms. Because these data are obtained from above Earth's atmosphere, they are uniquely sensitive to possible long-term changes of the Sun's size. We report here on the first homogeneous, highly precise, and complete solar-cycle measurement of the Sun's radius variability. Our results show that any intrinsic changes in the solar radius that are synchronous with the sunspot cycle must be smaller than 23 mas peak to peak. In addition, we find that the average solar radius must not be changing (on average) by more than 1.2 mas yr{sup -1}. If ground- and space-based measurements are both correct, the pervasive difference between the constancy of the solar radius seen from space and the apparent ground-based solar astrometric variability can only be accounted for by long-term changes in the terrestrial atmosphere.

Bush, R. I. [Stanford University, Stanford, CA 94305 (United States); Emilio, M. [Observatorio Astronomico-Departamento de Geociencias Universidade Estadual de Ponta Grossa, Parana (Brazil); Kuhn, J. R., E-mail: rock@sun.stanford.ed, E-mail: memilio@uepg.b, E-mail: kuhn@ifa.hawaii.ed [Institute for Astronomy, University of Hawaii, Woodlawn Dr., HI 96822 (United States)

2010-06-20T23:59:59.000Z

154

Kinematic Control of the Inertiality of the System of Tycho-2 and UCAC2 Stellar Proper Motions  

E-Print Network (OSTI)

Based on the Ogorodnikov-Milne model, we analyze the proper motions of Tycho-2 and UCAC2 stars. We have established that the model component that describes the rotation of all stars under consideration around the Galactic y axis differs significantly from zero at various magnitudes. We interpret this rotation found using the most distant stars as a residual rotation of the ICRS/Tycho-2 system relative to the inertial reference frame. For the most distant ($d\\approx900$ pc) Tycho-2 and UCAC2 stars, the mean rotation around the Galactic y axis has been found to be $M_{13}=-0.37\\pm0.04$ mas yr$^{-1}$. The proper motions of UCAC2 stars with magnitudes in the range $12-15^m$ are shown to be distorted appreciably by the magnitude equation in $\\mu_\\alpha\\cos\\delta$, which has the strongest effect for northern-sky stars with a coefficient of $-0.60\\pm0.05$ mas yr$^{-1}$ mag$^{-1}$. We have detected no significant effect of the magnitude equation in the proper motions of UCAC2 stars brighter than $\\approx11^m$.

Vadim V. Bobylev; Maxim Yu. Khovritchev

2006-08-26T23:59:59.000Z

155

THE CATALOG OF POSITIONS OF OPTICALLY BRIGHT EXTRAGALACTIC RADIO SOURCES OBRS-1  

SciTech Connect

It is expected that the European Space Agency mission Gaia will make it possible to determine coordinates in the optical domain of more than 500,000 quasars. In 2006, a radio astrometry project was launched with the overall goal of making comparisons between coordinate systems derived from future space-born astrometry instruments and the coordinate system constructed from analysis of global very long baseline interferometry (VLBI) more robust. Investigation of the rotation, zonal errors, and non-alignment of the radio and optical positions caused by both radio and optical structures is needed to validate both techniques. In order to support these studies, the densification of the list of compact extragalactic objects that are bright in both radio and optical ranges is desirable. A set of 105 objects from the list of 398 compact extragalactic radio sources with decl. >-10{sup 0} was observed with the Very Long Baseline Array and European VLBI Network (EVN) with the primary goal of producing images with milliarcsecond resolution. These sources are brighter than 18 mag in the V band, and they were previously detected by the EVN. In this paper, coordinates of observed sources have been derived with milliarcsecond accuracies from analysis of these VLBI observations using an absolute astrometry method. The catalog of positions for 105 target sources is presented. The accuracies of source coordinates are in the range of 0.3-7 mas, with a median of 1.1 mas.

Petrov, L., E-mail: Leonid.Petrov@lpetrov.net [ADNET Systems Inc./NASA GSFC, Greenbelt, MD 20771 (United States)

2011-10-15T23:59:59.000Z

156

A Methodology to Evaluate Agent Oriented Software Engineering Techniques  

SciTech Connect

Systems using software agents (or multi-agent systems, MAS) are becoming more popular within the development mainstream because, as the name suggests, an agent aims to handle tasks autonomously with intelligence. To benefit from autonomous control and reduced running costs, system functions are performed automatically. Agent-oriented considerations are being steadily accepted into the various software design paradigms. Agents may work alone, but most commonly, they cooperate toward achieving some application goal(s). MAS's are components in systems that are viewed as many individuals living in a society working together. From a SE perspective, solving a problem should encompass problem realization, requirements analysis, architecture design and implementation. These steps should be implemented within a life-cycle process including testing, verification, and reengineering to proving the built system is sound. In this paper, we explore the various applications of agent-based systems categorized into different application domains. A baseline is developed herein to help us focus on the core of agent concepts throughout the comparative study and to investigate both the object-oriented and agent-oriented techniques that are available for constructing agent-based systems. In each respect, we address the conceptual background associated with these methodologies and how available tools can be applied within specific domains.

Lin, Chia-En [University of North Texas; Kavi, Krishna M. [University of North Texas; Sheldon, Frederick T [ORNL; Daley, Kristopher M [ORNL; Abercrombie, Robert K [ORNL

2007-01-01T23:59:59.000Z

157

Observations of the pulsation of the Cepheid l Car with the Sydney University Stellar Interferometer  

E-Print Network (OSTI)

Observations of the southern Cepheid l Car to yield the mean angular diameter and angular pulsation amplitude have been made with the Sydney University Stellar Interferometer (SUSI) at a wavelength of 696 nm. The resulting mean limb-darkened angular diameter is 2.990+-0.017 mas (i.e. +-0.6 per cent) with a maximum-to-minimum amplitude of 0.560+-0.018 mas corresponding to 18.7+-0.6 per cent in the mean stellar diameter. Careful attention has been paid to uncertainties, including those in measurements, in the adopted calibrator angular diameters, in the projected values of visibility squared at zero baseline, and to systematic effects. No evidence was found for a circumstellar envelope at 696 nm. The interferometric results have been combined with radial displacements of the stellar atmosphere derived from selected radial velocity data taken from the literature to determine the distance and mean diameter of l Car. The distance is determined to be 525+-26 pc and the mean radius 169+-8R{solar). Comparison with pu...

Davis, J; Robertson, J G; Ireland, M J; North, J R; Tango, W J; Tuthill, P G

2008-01-01T23:59:59.000Z

158

Revealing the inner circumstellar disk of the T Tauri star S CrA N using the VLTI  

E-Print Network (OSTI)

Aims: We investigate the structure of the circumstellar disk of the T Tauri star S CrA N and test whether the observations agree with the standard picture proposed for Herbig Ae stars. Methods: Our observations were carried out with the VLTI/AMBER instrument in the H and K bands with the low spectral resolution mode. For the interpretation of our near-infrared AMBER and archival mid-infrared MIDI visibilities, we employed both geometric and temperature-gradient models. Results: To characterize the disk size, we first fitted geometric models consisting of a stellar point source, a ring-shaped disk, and a halo structure to the visibilities. In the H and K bands, we measured ring-fit radii of 0.73 +- 0.03 mas (corresponding to 0.095 +- 0.018 AU for a distance of 130 pc) and 0.85 +- 0.07 mas (0.111 +- 0.026 AU), respectively. This K-band radius is approximately two times larger than the dust sublimation radius of ~0.05 AU expected for a dust sublimation temperature of 1500 K and gray dust opacities, but approxima...

Vural, J; Kraus, S; Weigelt, G; Driebe, T; Benisty, M; Dugué, M; Massi, F; Monin, J -L; Vannier, M

2012-01-01T23:59:59.000Z

159

Metastability And Crystal Structure of The Bialkali Complex Metal Hydride NaK(BH4)2  

DOE Green Energy (OSTI)

A new bialkali borohydride, NaK(BH{sub 4}){sub 2}, was synthesized by mechanical milling of NaBH4 and KBH4 in a 1:1 ratio. The synthesis was conducted based on a prediction from a computational screening of hydrogen storage materials suggesting the potential stability of NaK(BH{sub 4}){sub 2}. The new phase was characterized using X-ray diffraction, Raman scattering and magic angle spinning (MAS) nuclear magnetic resonance (NMR). The Raman measurements indicated B-H vibrations of the (BH{sub 4}){sup -} anion, while magnetic resonance chemical shifts in {sup 23}Na, and {sup 39}K MAS NMR spectra showed new chemical environments for Na and K resulting from the formation of the new bialkali phase. X-ray diffraction spectra indicated a new crystal structure with rhombohedral symmetry, most likely in the space group R3, distinct from the starting materials NaBH{sub 4}, and KBH{sub 4}. Although in-situ XRD measurements indicated the material to be metastable, decomposing to the starting materials NaBH{sub 4} and KBH{sub 4}, the successful synthesis of NaK(BH{sub 4}){sub 2} demonstrates the ability of computational screening to predict candidates for hydrogen storage materials.

Seballos, L; Zhang, J Z; Ronnebro, E; Herberg, J L; Majzoub, E H

2008-05-19T23:59:59.000Z

160

A PARALLAX DISTANCE AND MASS ESTIMATE FOR THE TRANSITIONAL MILLISECOND PULSAR SYSTEM J1023+0038  

Science Conference Proceedings (OSTI)

The recently discovered transitional millisecond pulsar system J1023+0038 exposes a crucial evolutionary phase of recycled neutron stars for multiwavelength study. The system, comprising the neutron star itself, its stellar companion, and the surrounding medium, is visible across the electromagnetic spectrum from the radio to X-ray/gamma-ray regimes and offers insight into the recycling phase of millisecond pulsar evolution. Here, we report on multiple-epoch astrometric observations with the Very Long Baseline Array (VLBA) which give a system parallax of 0.731 {+-} 0.022 milliarcseconds (mas) and a proper motion of 17.98 {+-} 0.05 mas yr{sup -1}. By combining our results with previous optical observations, we are able to use the parallax distance of 1368{sup +42}{sub -{sub 39}} pc to estimate the mass of the pulsar to be 1.71 {+-} 0.16 M{sub Sun }, and we are also able to measure the three-dimensional space velocity of the system to be 126 {+-} 5 km s{sup -1}. Despite the precise nature of the VLBA measurements, the remaining {approx}3% distance uncertainty dominates the 0.16 M{sub Sun} error on our mass estimate.

Deller, A. T. [Netherlands Institute for Radio Astronomy (ASTRON), 7990-AA Dwingeloo (Netherlands); Archibald, A. M.; Kaspi, V. M. [Department of Physics, McGill University, 3600 University Street, Montreal, QC H3A 2T8 (Canada); Brisken, W. F. [National Radio Astronomy Observatory, Socorro, NM 87801 (United States); Chatterjee, S. [Astronomy Department, Cornell University, Ithaca, NY 14853 (United States); Janssen, G. H.; Lyne, A. G.; Stappers, B. [Jodrell Bank Centre for Astrophysics, School of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom); Lorimer, D.; McLaughlin, M. A. [Department of Physics, West Virginia University, Morgantown, WV 26506 (United States); Ransom, S. [National Radio Astronomy Observatory, Charlottesville, VA 22903 (United States); Stairs, I. H. [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1 (Canada)

2012-09-10T23:59:59.000Z

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161

Investigation of Ti-doped NaAlH4 by solid-state NMR  

DOE Green Energy (OSTI)

In recent years, the development of Ti-doped NaAlH{sub 4} as a hydrogen storage material has gained attention because of its large weight percentage of hydrogen ({approx}5%) compared to traditional interstitial hydrides. The addition of transition-metal dopants, in the form of Ti-halides, such as TiCl{sub 3}, dramatically improves the kinetics of the absorption and desorption of hydrogen from NaAlH{sub 4}. However, the role that Ti plays in enhancing the absorption and desorption of H{sub 2} is still unknown. In the present study, {sup 27}Al, {sup 23}Na, and {sup 1}H MAS (Magic Angle Spinning) NMR (Nuclear Magnetic Resonance) has been performed to understand the titanium speciation in Ti-doped NaAlH{sub 4}. All experiments were performed on a sample of crushed single crystals exposed to Ti during growth, a sample of solvent-mixed 4TiCl{sub 3} + 112NaAlH{sub 4}, a reacted sample of solvent-mixed TiCl{sub 3} + {sup 3}NaAlH{sub 4} with THF, and a reacted sample of ball-milled TiCl3 + 3NaAlH{sub 4}. The {sup 27}Al MAS NMR has shown differences in compound formation between solvent-mixed TiCl{sub 3} + 3NaAlH{sub 4} with THF and the mechanically ball-milled TiCl{sub 3} + 3NaAlH{sub 4}. {sup 27}Al MAS NMR of the mechanically ball-milled mixture of fully-reacted TiCl{sub 3} + 3NaAlH{sub 4} showed spectral signatures of TiAl{sub 3} while, the solvent-mixed 4TiCl{sub 3} + 112NaAlH{sub 4}, which is totally reacted, does not show the presences of TiAl{sub 3}, but shows the existence of Al{sub 2}O{sub 3}.

Maxwell, R; Majzoub, E; Herberg, J

2003-11-24T23:59:59.000Z

162

Patient-specific dose estimation for pediatric chest CT  

SciTech Connect

Current methods for organ and effective dose estimations in pediatric CT are largely patient generic. Physical phantoms and computer models have only been developed for standard/limited patient sizes at discrete ages (e.g., 0, 1, 5, 10, 15 years old) and do not reflect the variability of patient anatomy and body habitus within the same size/age group. In this investigation, full-body computer models of seven pediatric patients in the same size/protocol group (weight: 11.9-18.2 kg) were created based on the patients' actual multi-detector array CT (MDCT) data. Organs and structures in the scan coverage were individually segmented. Other organs and structures were created by morphing existing adult models (developed from visible human data) to match the framework defined by the segmented organs, referencing the organ volume and anthropometry data in ICRP Publication 89. Organ and effective dose of these patients from a chest MDCT scan protocol (64 slice LightSpeed VCT scanner, 120 kVp, 70 or 75 mA, 0.4 s gantry rotation period, pitch of 1.375, 20 mm beam collimation, and small body scan field-of-view) was calculated using a Monte Carlo program previously developed and validated to simulate radiation transport in the same CT system. The seven patients had normalized effective dose of 3.7-5.3 mSv/100 mAs (coefficient of variation: 10.8%). Normalized lung dose and heart dose were 10.4-12.6 mGy/100 mAs and 11.2-13.3 mGy/100 mAs, respectively. Organ dose variations across the patients were generally small for large organs in the scan coverage (<7%), but large for small organs in the scan coverage (9%-18%) and for partially or indirectly exposed organs (11%-77%). Normalized effective dose correlated weakly with body weight (correlation coefficient: r=-0.80). Normalized lung dose and heart dose correlated strongly with mid-chest equivalent diameter (lung: r=-0.99, heart: r=-0.93); these strong correlation relationships can be used to estimate patient-specific organ dose for any other patient in the same size/protocol group who undergoes the chest scan. In summary, this work reported the first assessment of dose variations across pediatric CT patients in the same size/protocol group due to the variability of patient anatomy and body habitus and provided a previously unavailable method for patient-specific organ dose estimation, which will help in assessing patient risk and optimizing dose reduction strategies, including the development of scan protocols.

Li Xiang; Samei, Ehsan; Segars, W. Paul; Sturgeon, Gregory M.; Colsher, James G.; Frush, Donald P. [Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 and Department of Radiology, Duke Advanced Imaging Laboratories, Duke University Medical Center, Durham, North Carolina 27705 (United States); Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 (United States); Department of Radiology, Duke Advanced Imaging Laboratories, Duke University Medical Center, Durham, North Carolina 27705 (United States); Department of Physics, Duke University, Durham, North Carolina 27710 (United States); and Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708 (United States); Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 and Department of Radiology, Duke Advanced Imaging Laboratories, Duke University Medical Center, Durham, North Carolina 27705 (United States); Department of Radiology, Duke Advanced Imaging Laboratories, Duke University Medical Center, Durham, North Carolina 27705 (United States); Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 and Global Applied Science Laboratory, GE Healthcare, Waukesha, Wisconsin 53188 (United States); Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 and Department of Radiology, Division of Pediatric Radiology, Duke University Medical Center, Durham North Carolina 27710 (United States)

2008-12-15T23:59:59.000Z

163

Publications  

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

9 results: 9 results: BibTex RIS RTF XML Sort by: Author Title Type [ Year (Desc) ] Filters: Author is Guoying Chen [Clear All Filters] 2011 Chen, Guoying, Alpesh K. Shukla, Xiangyun Song, and Thomas J. Richardson. "Improved Kinetics and Stabilities in Mg-Sybstained Li-MnPO4." J. of Materials Chemistry 21 (2011): 10126. 2010 Chen, Guoying, and Thomas J. Richardson. "Continuity and Performance in Composite Electrodes." Journal of Power Sources 195 (2010): 5387. Cabana, Jordi, Junichi Shirakawa, Guoying Chen, Thomas J. Richardson, and Clare P. Grey. "MAS NMR Study of the Metastable Solid Solution Found in the LiFePO4/FePO4 Sustem." Chemistry of Materials 22 (2010): 1249. Chen, Guoying, and Thomas J. Richardson. "Overcharge Protection for 4 V

164

User:Graham7781 | Open Energy Information  

Open Energy Info (EERE)

User page User page Edit with form History Facebook icon Twitter icon » User:Graham7781 Jump to: navigation, search Brazil Name Graham Hill Location Denver, Colorado Edits 7932 Friends User Edits GregZiebold 3711 JZ 42 Jorn.Aabakken 5 Rmckeel 1772 Woodjr 59997 Twong 24774 Dbrodt 21 I am a Research Analyst at the National Renewable Energy Laboratory, and a recent graduate of the University of Denver in MAS Environmental Policy and Management. I've been working extensively at NREL on expanding Openei.org by adding contributions, editing and patrolling pages, and developing training tutorial videos to guide users on how to use the wiki. I also have led the creation of the Renewable Energy News Gateway and the Oil and Gas gateway. I've collaborated with Jarett Zuboy (User:JZ) on helping build the external

165

Page not found | Department of Energy  

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

61 - 18570 of 31,917 results. 61 - 18570 of 31,917 results. Download Visualization & Controls Program Peer Review http://energy.gov/oe/downloads/visualization-controls-program-peer-review Download Independent Oversight Assessment, Idaho Cleanup Project Sodium Bearing Waste Treatment Project- November 2012 Assessment of Nuclear Safety Culture at the Idaho Cleanup Project Sodium Bearing Waste Treatment Project http://energy.gov/hss/downloads/independent-oversight-assessment-idaho-cleanup-project-sodium-bearing-waste-treatment Download MAS 10.2 Control of Measuring and Test Equipment, 3/9/95 The objective of this surveillance is to verify that the contractor maintains adequate control of tools, gauges, instruments, devices or systems used to inspect, test, calibrate, measure or...

166

Page not found | Department of Energy  

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

71 - 25180 of 28,560 results. 71 - 25180 of 28,560 results. Download CMS 3.3 Verification of System Configuration and Operations, 3/27/95 The objective of this surveillance is for the Facility Representative to verify that the facility's configuration and operations are consistent with facility design basis documentation. These... http://energy.gov/hss/downloads/cms-33-verification-system-configuration-and-operations-32795 Download ENS 7.1 Definition of Design Requirements, 3/30/95 The objective of this surveillance is to evaluate the effectiveness of the contractor's program to establish comprehensive design requirements for modifications or new installations before detailed... http://energy.gov/hss/downloads/ens-71-definition-design-requirements-33095 Download MAS 10.2 Control of Measuring and Test Equipment, 3/9/95

167

A dual emission mechanism in Sgr A*/L' ?  

E-Print Network (OSTI)

We have collected in 2004 adaptive optics corrected L' images of the Galactic Center region with NAOS-CONICA at VLT. A strong variability was observed as well as a correlation between the photocenter positions and fluxes of the L'-band counterpart of Sgr A*. It is interpreted as the combined emission of a point-like flaring source at the position of Sgr A*/IR itself and an extended dust structure, 75 mas south west of Sgr A*/IR, which we name Sgr A*-f. We examine the different possible mechanisms to explain this dual Sgr A* L' emission and conclude it is likely a flaring emission associated to energetic events in the close environment of the black hole plus a quiescent emission resulting from the collision of Sgr A*-f by a jet from Sgr A*.

Yann Clénet; Daniel Rouan; Damien Gratadour; Olivier Marco; Pierre Léna; Nancy Ageorges; Eric Gendron

2005-07-05T23:59:59.000Z

168

Study of Serum Alanine-Aminotransferase Levels in . . .  

E-Print Network (OSTI)

Study of serum alanine-aminotransferase levels in blood donors in Spain MIGUEL LOZANO, JOAN CID, JOS LUIS BEDINI,* ROBERTO MAZZARA, NRIA GIMENEZ,* ERNEST MAS,* ANTONIO BALLESTA,* ANTONIO ORDINAS Department of Hemotherapy and Hemostasis, and *Biochemistry, Hospital Clnic i Provincial, University of Barcelona, Barcelona, Spain Correspondence: Miguel Lozano, MD, PhD, Hospital Clnic Provincial, Depart. of Hemotherapy and Hemostasis, Villarroel 170, 08036 Barcelona, Spain. Phone: international +34-3-2275448 . Fax: international +34-32275448 or 2275454 . e-mail: mlozano@medicina.ub.es Background and Objective. Serum alanine-aminotransferase (ALT) is being used as a surrogate test for preventing post-transfusion viral hepatitis. However, ALT elevation is influenced by many factors. We have studied ALT levels in 1,036 consecutive blood donors to determine their association with gender, obesity, and hepatitis virus infection markers. Design and Methods. In each donation asparta...

Miguel Lozano; Joan Cid; José Luis Bedini; Roberto Mazzara; Núria Gimenez; Ernest Mas; Antonio Ballesta; Antonio Ordinas

1998-01-01T23:59:59.000Z

169

Pulsar B2224+65 and Jets: A Two Epoch X-ray Analysis  

E-Print Network (OSTI)

We present an X-ray morphological and spectroscopic study of the pulsar B2224+65 and its apparent jet-like X-ray features based on two epoch Chandra observations. The main X-ray feature, which shows a large directional offset from the ram-pressure confined pulsar wind nebula (Guitar Nebula), is broader in apparent width and more luminous in the second epoch than the first. Furthermore, the sharp leading edge is found to have a proper motion consistent with that of the pulsar (~180 mas/yr). The combined data set also provides evidence for the presence of a counter feature, albeit substantially fainter and shorter than the main one. These results are consistent with a simple model of relativistic jet outflow originating from the pulsar and ram-pressure confined by the unusually rapid motion of the pulsar.

Johnson, S P

2010-01-01T23:59:59.000Z

170

Aging Studies of Filled and Unfilled VCE  

SciTech Connect

This report presents data on the effects of temperature and gamma radiation on the chemical and structural properties of both filled and unfilled VCE material produced by the Kansas City Plant using WR-qualified processes. Thermal effects up to 300 C and gamma irradiation doses of 1 MRad and 25 MRad were investigated under atmospheric conditions. Characterization techniques used in the study comprise Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), X-ray Diffraction (XRD), Tensile Testing, Solid Phase MicroExtraction - Gas Chromatography/Mass Spectrometry (SPME-GC/MS), phenol extraction followed by HPLC, and various Nuclear Magnetic Resonance (NMR) techniques including: {sup 13}C, {sup 13}C {l_brace}{sup 1}H{r_brace} cross polarization (CP), {sup 1}H magic angle spinning (MAS), 13C{l_brace}{sup 1}H{r_brace} Wide-line-Separation (2D-WISE) and development of Center band-Only Detection of Exchange (CODEX).

Letant, S; Herberg, J; Alviso, C; Small, W; Mulcahy, H; Pearson, M; Wilson, T; Chinn, S; Maxwell, R

2009-11-10T23:59:59.000Z

171

A disc in the heart of the Ant nebula  

E-Print Network (OSTI)

We present the discovery of a silicate disc at the centre of the planetary nebula Mz3 (the Ant). The nebula was observed with MIDI on the Very Large Telescope Interferometer (VLTI). The visibilities obtained at different orientations clearly indicate the presence of a dusty, nearly edge-on disc in the heart of the nebula. An amorphous silicate absorption feature is clearly seen in our mid-IR spectrum and visibility curves. We used radiative transfer Monte Carlo simulations to constrain the geometrical and physical parameters of the disc. We derive an inner radius of 9 AU (~6mas assuming D=1.4kpc). This disc is perpendicular to, but a factor of 10^{3} smaller than the optical bipolar outflow.

Lykou, Foteini; Lagadec, Eric; Zijlstra, Albert

2007-01-01T23:59:59.000Z

172

A disc in the heart of the Ant nebula  

E-Print Network (OSTI)

We present the discovery of a silicate disc at the centre of the planetary nebula Mz3 (the Ant). The nebula was observed with MIDI on the Very Large Telescope Interferometer (VLTI). The visibilities obtained at different orientations clearly indicate the presence of a dusty, nearly edge-on disc in the heart of the nebula. An amorphous silicate absorption feature is clearly seen in our mid-IR spectrum and visibility curves. We used radiative transfer Monte Carlo simulations to constrain the geometrical and physical parameters of the disc. We derive an inner radius of 9 AU (~6mas assuming D=1.4kpc). This disc is perpendicular to, but a factor of 10^{3} smaller than the optical bipolar outflow.

Foteini Lykou; Olivier Chesneau; Eric Lagadec; Albert Zijlstra

2007-10-02T23:59:59.000Z

173

Conceptual design of minor actinides burner with an accelerator-driven subcritical system.  

SciTech Connect

In the environmental impact study of the Yucca Mountain nuclear waste repository, the limit of spent nuclear fuel (SNF) for disposal is assessed at 70,000 metric tons of heavy metal (MTHM), among which 63,000 MTHM are the projected SNF discharge from U.S. commercial nuclear power plants though 2011. Within the 70,000 MTHM of SNF in storage, approximately 115 tons would be minor actinides (MAs) and 585 tons would be plutonium. This study describes the conceptual design of an accelerator-driven subcritical (ADS) system intended to utilize (burn) the 115 tons of MAs. The ADS system consists of a subcritical fission blanket where the MAs fuel will be burned, a spallation neutron source to drive the fission blanket, and a radiation shield to reduce the radiation dose to an acceptable level. The spallation neutrons are generated from the interaction of a 1 GeV proton beam with a lead-bismuth eutectic (LBE) or liquid lead target. In this concept, the fission blanket consists of a liquid mobile fuel and the fuel carrier can be LBE, liquid lead, or molten salt. The actinide fuel materials are dissolved, mixed, or suspended in the liquid fuel carrier. Therefore, fresh fuel can be fed into the fission blanket to adjust its reactivity and to control system power during operation. Monte Carlo analyses were performed to determine the overall parameters of an ADS system utilizing LBE as an example. Steady-state Monte Carlo simulations were studied for three fission blanket configurations that are similar except that the loaded amount of actinide fuel in the LBE is either 5, 7, or 10% of the total volume of the blanket, respectively. The neutron multiplication factor values of the three configurations are all approximately 0.98 and the MA initial inventories are each approximately 10 tons. Monte Carlo burnup simulations using the MCB5 code were performed to analyze the performance of the three conceptual ADS systems. Preliminary burnup analysis shows that all three conceptual ADS systems consume about 1.2 tons of actinides per year and produce 3 GW thermal power, with a proton beam power of 25 MW. Total MA fuel that would be consumed in the first 10 years of operation is 9.85, 11.80, or 12.68 tons, respectively, for the systems with 5, 7, or 10% actinide fuel particles loaded in the LBE. The corresponding annual MA fuel transmutation rate after reaching equilibrium at 10 years of operation is 0.83, 0.94, or 1.02 tons/year, respectively. Assuming that the ADS systems can be operated for 35 full-power years, the total MAs consumed in the three ADS systems are 30.6, 35.3, and 37.2 tons, respectively. For the three configurations, it is estimated that 3.8, 3.3, or 3.1 ADS system units are required to utilize the entire 115 tons of MA fuel in the SNF inventory, respectively.

Cao, Y.; Gohar, Y. (Nuclear Engineering Division)

2011-11-04T23:59:59.000Z

174

A New Quadruple Gravitational Lens System: CLASS B0128+437  

E-Print Network (OSTI)

High resolution MERLIN observations of a newly-discovered four-image gravitational lens system, B0128+437, are presented. The system was found after a careful re-analysis of the entire CLASS dataset. The MERLIN observations resolve four components in a characteristic quadruple-image configuration; the maximum image separation is 542 mas and the total flux density is 48 mJy at 5 GHz. A best-fit lens model with a singular isothermal ellipsoid results in large errors in the image positions. A significantly improved fit is obtained after the addition of a shear component, suggesting that the lensing system is more complex and may consist of multiple deflectors. The integrated radio spectrum of the background source indicates that it is a GigaHertz-Peaked Spectrum (GPS) source. It may therefore be possible to resolve structure within the radio images with deep VLBI observations and thus better constrain the lensing mass distribution.

P. M. Phillips; M. A. Norbury; L. V. E. Koopmans; I. W. A. Browne; N. J. Jackson; P. N. Wilkinson; A. D. Biggs; R. D. Blandford; A. G. de Bruyn; C. D. Fassnacht; P. Helbig; S. Mao; D. R. Marlow; S. T. Myers; T. J. Pearson; A. C. S. Readhead; D. Rusin; E. Xanthopoulos

2000-09-20T23:59:59.000Z

175

FEASIBILITY OF RECYCLING PLUTONIUM AND MINOR ACTINIDES IN LIGHT WATER REACTORS USING HYDRIDE FUEL  

Science Conference Proceedings (OSTI)

The objective of this DOE NERI program sponsored project was to assess the feasibility of improving the plutonium (Pu) and minor actinide (MA) recycling capabilities of pressurized water reactors (PWRs) by using hydride instead of oxide fuels. There are four general parts to this assessment: 1) Identifying promising hydride fuel assembly designs for recycling Pu and MAs in PWRs 2) Performing a comprehensive systems analysis that compares the fuel cycle characteristics of Pu and MA recycling in PWRs using the promising hydride fuel assembly designs identified in Part 1 versus using oxide fuel assembly designs 3) Conducting a safety analysis to assess the likelihood of licensing hydride fuel assembly designs 4) Assessing the compatibility of hydride fuel with cladding materials and water under typical PWR operating conditions Hydride fuel was found to offer promising transmutation characteristics and is recommended for further examination as a possible preferred option for recycling plutonium in PWRs.

Greenspan, Ehud; Todreas, Neil; Taiwo, Temitope

2009-03-10T23:59:59.000Z

176

Equilibrium relations in the system TiO{sub 2}/V{sub 2}O{sub 5}/P{sub 2}O{sub 5} and crystal structure of a NASICON-related vanadyl(V) titanium(IV) phosphate  

SciTech Connect

Vanadyl(V)-titanium-orthophosphate (V{sup V}O)Ti{sup IV}{sub 6}(PO{sub 4}){sub 9} is formed by solid state reactions in the temperature range 525{<=}{theta}{<=}780 Degree-Sign C. At higher temperature decomposition into V{sub 2}O{sub 5} and the hitherto unknown solid solution Ti(P{sub 1-x}V{sub x}){sub 2}O{sub 7} (0{<=}x{<=}0.23; 0.30{<=}x{<=}0.43) is observed. The process of phase formation has been monitored by MAS-NMR ({sup 31}P, {sup 51}V) spectroscopy. Equilibrium phase relations in the quaternary system TiO{sub 2}/VO{sub 2.5}/PO{sub 2.5} have been determined. A structure analysis from X-ray single-crystal data (P6{sub 3}/m (No. 176), Z=2; a=8.4438(3) A, c=22.215(1) A, 14 independent atoms, 87 variables, 2066 unique reflections, R1=0.032, wR2=0.084) shows the relationship of (V{sup V}O)Ti{sup IV}{sub 6}(PO{sub 4}){sub 9} to the NASICON structure family. In marked contrast to the other members of this family [Ti{sup IV}{sub 2}O{sub 9}] double-octahedra and strongly distorted tetrahedral [(V{sup V}=O)O{sub 3}] groups are observed besides isolated [Ti{sup IV}O{sub 6}] octahedra and phosphate tetrahedra. The structure model is in agreement with the results from MAS-NMR ({sup 31}P, {sup 51}V) spectroscopy. - Graphical abstract: (V{sup V}O)Ti{sup IV}{sub 6}(PO{sub 4}){sub 9} belongs to the NASICON structure family. Its structure contains [Ti{sup IV}{sub 2}O{sub 9}] double-octahedra and unprecedented, strongly distorted tetrahedral [(V{sup V}=O)O{sub 3}] groups, in stark contrast to other members of this family. The structure model is in agreement with the results from MAS-NMR ({sup 31}P, {sup 51}V) spectroscopy. Highlights: Black-Right-Pointing-Pointer Equilibrium relations for the subsolidus have been established for the system TiO{sub 2}/V{sub 2}O{sub 5}/P{sub 2}O{sub 5}. Black-Right-Pointing-Pointer Phase formation has been monitored by XRPD as well as by {sup 31}P- and {sup 51}-MAS-NMR. Black-Right-Pointing-Pointer A solid solution Ti(P{sub 1-x}V{sub x}){sub 2}O{sub 7} exists up to x=0.43 with a miscibility gap at 0.23{<=}x{<=}0.30. Black-Right-Pointing-Pointer The crystal structure of the new NASICON-related phosphate (V{sup V}O)Ti{sup IV}{sub 6}(PO{sub 4}){sub 9} is reported. Black-Right-Pointing-Pointer The crystal structure contains the unprecedented [(V=O)O{sub 3}] group.

Titlbach, Sven; Hoffbauer, Wilfried [Institut fuer Anorganische Chemie der Universitaet Bonn, Gerhard-Domagk-Str. 1, D-53121 Bonn (Germany)] [Institut fuer Anorganische Chemie der Universitaet Bonn, Gerhard-Domagk-Str. 1, D-53121 Bonn (Germany); Glaum, Robert, E-mail: rglaum@uni-bonn.de [Institut fuer Anorganische Chemie der Universitaet Bonn, Gerhard-Domagk-Str. 1, D-53121 Bonn (Germany)] [Institut fuer Anorganische Chemie der Universitaet Bonn, Gerhard-Domagk-Str. 1, D-53121 Bonn (Germany)

2012-12-15T23:59:59.000Z

177

M.Batistella,  

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

55 a 563. 55 a 563. 1 Resultados do LBA e uma Perspectiva da Futura Pesquisa Amazônica M.Batistella, 1 P. Artaxo, 2 C. Nobre, 3 M. Bustamante, 4 e F. Luizão 5 Este capítulo resume resultados selecionados do Experimento de Grande Escala da Biosfera-Atmosfera na Amazônia (LBA) e descreve, brevemente, uma visão da pesquisa futura amazônica. Enfatiza-se a necessidade de pesquisa sobre as interações sociedade e meio ambiente no contexto de mudança regional e global. O LBA desenvolveu capacidade científica e institucional na Amazônia, mas seu desempenho para promover o desenvolvimento sustentável foi restrito porque o programa focalizou, em sua grande parte, o avanço do conhecimento básico, com menos ênfase nos estudos integrados, especificamente

178

Implementing the National Broadband  

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

MEEKER COOPERATIVE LIGHT AND POWER-MINNESOTA MEEKER COOPERATIVE LIGHT AND POWER-MINNESOTA I. Introduction a. Identification/description of your company. Meeker Cooperative Light and Power (MCLP) is a non-profit electric cooperative serving 9120 consumers and is located in central Minnesota. The cooperative serves an area of approximately 1410 square miles. The geography varies from flat to moderate rolling hills with many lakes and wooded areas. For the most part the area is relatively sparsely populated. The average consumer density is less than five consumers per mile. All power purchases are from our cooperative power suppliers of Basin Electric Power COOP and Great River Energy (GRE). Overview of communications networks 1. 220 MHz radio point to point 2. 900 MHz MAS radio

179

Light and Motion in SDSS Stripe 82: The Catalogues  

E-Print Network (OSTI)

We present a new public archive of light-motion curves in Sloan Digital Sky Survey (SDSS) Stripe 82, covering 99 deg in right ascension from RA = 20.7 h to 3.3 h and spanning 2.52 deg in declination from Dec = -1.26 to 1.26 deg, for a total sky area of ~249 sq deg. Stripe 82 has been repeatedly monitored in the u, g, r, i and z bands over a seven-year baseline. Objects are cross-matched between runs, taking into account the effects of any proper motion. The resulting catalogue contains almost 4 million light-motion curves of stellar objects and galaxies. The photometry are recalibrated to correct for varying photometric zeropoints, achieving ~20 mmag and ~30 mmag root-mean-square (RMS) accuracy down to 18 mag in the g, r, i and z bands for point sources and extended sources, respectively. The astrometry are recalibrated to correct for inherent systematic errors in the SDSS astrometric solutions, achieving ~32 mas and ~35 mas RMS accuracy down to 18 mag for point sources and extended sources, respectively. For each light-motion curve, 229 photometric and astrometric quantities are derived and stored in a higher-level catalogue. On the photometric side, these include mean exponential and PSF magnitudes along with uncertainties, RMS scatter, chi^2 per degree of freedom, various magnitude distribution percentiles, object type (stellar or galaxy), and eclipse, Stetson and Vidrih variability indices. On the astrometric side, these quantities include mean positions, proper motions as well as their uncertainties and chi^2 per degree of freedom. The here presented light-motion curve catalogue is complete down to r~21.5 and is at present the deepest large-area photometric and astrometric variability catalogue available.

D. M. Bramich; S. Vidrih; L. Wyrzykowski; J. A. Munn; H. Lin; N. W. Evans; M. C. Smith; V. Belokurov; G. Gilmore; D. B. Zucker; P. C. Hewett; L. L. Watkins; D. C. Faria; M. Fellhauer; G. Miknaitis; D. Bizyaev; Z. Ivezic; D. P. Schneider; S. A. Snedden; E. Malanushenko; V. Malanushenko; K. Pan

2008-01-31T23:59:59.000Z

180

Deep Astrometric Standards (DAS) and Galactic Structure  

E-Print Network (OSTI)

The advent of next-generation imaging telescopes such as LSST and Pan-STARRS has revitalized the need for deep and precise reference frames. The proposed weak-lensing observations with these facilities put the highest demands on image quality over wide angles on the sky. It is particularly difficult to achieve a sub-arcsecond PSF on stacked images, where precise astrometry plays a key role. Current astrometric standards are insufficient to achieve the science goals of these facilities. We thus propose the establishing of a few selected deep (V=25) astrometric standards (DAS). These will enable a reliable geometric calibration of solid-state mosaic detectors in the focal plane of large ground-based telescopes and make a substantial contribution to our understanding of stellar populations in the Milky Way. In this paper we motivate the need for such standards and discuss the strategy of their selection and acquisition and reduction techniques. The feasibility of DAS is demonstrated by a pilot study around the open cluster NGC 188, using the KPNO 4m CCD Mosaic camera, and by Subaru Suprime-Cam observations. The goal of reaching an accuracy of 5-10 mas in positions and obtaining absolute proper motions good to 2 mas/yr over a several square-degree area is challenging, but reachable with the NOAO 4m telescopes and CCD mosaic imagers or a similar set-up. Our proposed DAS aims to establish four fields near the Galactic plane, at widely separated coordinates. In addition to their utilitarian purpose for DAS, the data we will obtain in these fields will enable fundamental Galactic science in their own right. The positions, proper motions, and VI photometry of faint stars will address outstanding questions of Galactic disk formation and evolution, stellar buildup and mass assembly via merger events.

I. Platais; R. F. G. Wyse; N. Zacharias

2005-09-20T23:59:59.000Z

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181

KINEMATICS IN KAPTEYN'S SELECTED AREA 76: ORBITAL MOTIONS WITHIN THE HIGHLY SUBSTRUCTURED ANTICENTER STREAM  

Science Conference Proceedings (OSTI)

We have measured the mean three-dimensional kinematics of stars in Kapteyn's Selected Area (SA) 76 (l = 209.{sup 0}3, b = 26.{sup 0}4) that were selected to be Anticenter Stream (ACS) members on the basis of their radial velocities (RVs), proper motions (PMs), and location in the color-magnitude diagram. From a total of 31 stars ascertained to be ACS members primarily from its main-sequence turnoff, a mean ACS RV (derived from spectra obtained with the Hydra multi-object spectrograph on the WIYN 3.5 m telescope) of V{sub helio} = 97.0 {+-} 2.8 km s{sup -1} was determined, with an intrinsic velocity dispersion {sigma}{sub o} = 12.8 {+-} 2.1 km s{sup -1}. The mean absolute PMs of these 31 ACS members are {mu}{sub {alpha}} cos {delta} = -1.20 {+-} 0.34 mas yr{sup -1} and {mu}{sub {delta}} = -0.78 {+-} 0.36 mas yr{sup -1}. At a distance to the ACS of 10 {+-} 3 kpc, these measured kinematical quantities produce an orbit that deviates by {approx}30{sup 0} from the well-defined swath of stellar overdensity constituting the ACS in the western portion of the Sloan Digital Sky Survey footprint. We explore possible explanations for this and suggest that our data in SA 76 are measuring the motion of a kinematically cold sub-stream among the ACS debris that was likely a fragment of the same infalling structure that created the larger ACS system. The ACS is clearly separated spatially from the majority of claimed Monoceros ring detections in this region of the sky; however, with the data in hand, we are unable to either confirm or rule out an association between the ACS and the poorly understood Monoceros structure.

Carlin, Jeffrey L.; Majewski, Steven R. [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904-4325 (United States); Casetti-Dinescu, Dana I.; Girard, Terrence M. [Astronomy Department, Yale University, P.O. Box 208101, New Haven, CT 06520-8101 (United States); Grillmair, Carl J., E-mail: jc4qn@mail.astro.virginia.ed, E-mail: srm4n@virginia.ed, E-mail: dana@astro.yale.ed, E-mail: girard@astro.yale.ed, E-mail: carl@ipac.caltech.ed [Spitzer Science Center, 1200 E. California Blvd., Pasadena, CA 91125 (United States)

2010-12-20T23:59:59.000Z

182

SPARSE APERTURE MASKING OBSERVATIONS OF THE FL Cha PRE-TRANSITIONAL DISK  

Science Conference Proceedings (OSTI)

We present deep Sparse Aperture Masking (SAM) observations obtained with the ESO Very Large Telescope of the pre-transitional disk object FL Cha (SpT = K8, d = 160 pc), the disk of which is known to have a wide optically thin gap separating optically thick inner and outer disk components. We find non-zero closure phases, indicating a significant flux asymmetry in the K{sub S} -band emission (e.g., a departure from a single point source detection). We also present radiative transfer modeling of the spectral energy distribution of the FL Cha system and find that the gap extends from 0.06{sup +0.05}{sub -0.01} AU to 8.3 {+-} 1.3 AU. We demonstrate that the non-zero closure phases can be explained almost equally well by starlight scattered off the inner edge of the outer disk or by a (sub)stellar companion. Single-epoch, single-wavelength SAM observations of transitional disks with large cavities that could become resolved should thus be interpreted with caution, taking the disk and its properties into consideration. In the context of a binary model, the signal is most consistent with a high-contrast ({Delta}K{sub S} {approx} 4.8 mag) source at a {approx}40 mas (6 AU) projected separation. However, the flux ratio and separation parameters remain highly degenerate and a much brighter source ({Delta}K{sub S} {approx} 1 mag) at 15 mas (2.4 AU) can also reproduce the signal. Second-epoch, multi-wavelength observations are needed to establish the nature of the SAM detection in FL Cha.

Cieza, Lucas A.; Mathews, Geoffrey S.; Kraus, Adam L. [Institute for Astronomy, University of Hawaii at Manoa, Honolulu, HI 96822 (United States); Lacour, Sylvestre [LESIA, CNRS/UMR-8109, Observatoire de Paris, UPMC, Universite Paris Diderot, 5 place Jules Janssen, F-92195, Meudon (France); Schreiber, Matthias R.; Canovas, Hector [Departamento de Fisica y Astronomia, Universidad de Valparaiso, Valparaiso (Chile); Casassus, Simon; Jordan, Andres; Menard, Francois [Millenium Nucleus 'Protoplanetary Disks in ALMA Early Science', Universidad de Chile, Casilla 36-D, Santiago (Chile); Perez, Sebastian [Departamento de Astronomia, Universidad de Chile, Camino del Observatorio 1515, Las Condes, Santiago (Chile); Tuthill, Peter [School of Physics, University of Sydney, NSW 2006 (Australia); Ireland, Michael J., E-mail: lcieza@ifa.hawaii.edu [Department of Physics and Astronomy, Macquarie University, NSW 2109 (Australia)

2013-01-01T23:59:59.000Z

183

Automatic tuning of agent-based models using genetic algorithms  

E-Print Network (OSTI)

When developping multi-agent systems (MAS) or models in the context of agent-based simulation (ABS), the tuning of the model constitutes a crucial step of the design process. Indeed, agent-based models are generally characterized by lots of parameters, which together determine the global dynamics of the system. Moreover, small changes made to a single parameter sometimes lead to a radical modification of the dynamics of the whole system. The development and the parameter setting of an agent-based model can thus become long and tedious if we have no accurate, automatic and systematic strategy to explore this parameter space. That’s the development of such a strategy that we work on, suggesting the use of genetic algorithms. The idea is to capture in the fitness function the goal of the design process (efficiency for MAS that realize a given function, realism for agent-based models, etc.) and to make the model automatically evolve in that direction. However the use of genetic algorithms (GA) in the context of ABS raises specific difficulties that we develop in this article, explaining possible solutions and illustrating them on a simple and well-known model: the food-foraging by a colony of ants. We apply the method to a more complex example. We work on the simulation of the glycolysis and the phosphotranferase systems in Escherichia coli. In this work, we are interested in testing the hypothesis of hyperstructures, which are believed to improve the behavior of a cell. We try to determine under what conditions this may be true, and how these hyperstructures may function. 1

Benoît Calvez; Guillaume Hutzler

2005-01-01T23:59:59.000Z

184

A CATALOG OF NEAR-IR SOURCES FOUND TO BE UNRESOLVED WITH MILLIARCSECOND RESOLUTION  

SciTech Connect

Calibration is one of the long-standing problems in optical interferometric measurements, particularly with long baselines which demand stars with angular sizes on the milliarcsecond scale and no detectable companions. While systems of calibrators have been generally established for the near-infrared in the bright source regime (K {approx}< 3 mag), modern large interferometers are sensitive to significantly fainter magnitudes. We aim to provide a list of sources found to be unresolved from direct observations with high angular resolution and dynamic range, which can be used to choose interferometric calibrators. To this purpose, we have used a large number of lunar occultations recorded with the ISAAC instrument at the Very Large Telescope to select sources found to be unresolved and without close companions. An algorithm has been used to determine the limiting angular resolution achieved for each source, taking into account a noise model built from occulted and unocculted portions of the light curves. We have obtained upper limits on the angular sizes of 556 sources, with magnitudes ranging from K{sub s} Almost-Equal-To 4 to 10, with a median of 7.2 mag. The upper limits on possible undetected companions (within Almost-Equal-To 0.''5) range from K{sub s} Almost-Equal-To 8 to 13, with a median of 11.5 mag. One-third of the sources have angular sizes {<=}1 mas, and two-thirds have sizes {<=}2 mas. This list of unresolved sources matches well the capabilities of current large interferometric facilities. We also provide available cross-identifications, magnitudes, spectral types, and other auxiliary information. A fraction of the sources are found to be potentially variable. The list covers parts of the Galactic Bulge and in particular the vicinity of the Galactic Center, where extinction is very significant and traditional lists of calibrators are often insufficient.

Richichi, A. [National Astronomical Research Institute of Thailand, 191 Siriphanich Bldg., Huay Kaew Rd., Suthep, Muang, Chiang Mai 50200 (Thailand); Fors, O. [Departament Astronomia i Meteorologia and Institut de Ciencies del Cosmos (ICC), Universitat de Barcelona (UB/IEEC), Marti i Franques 1, E-08028 Barcelona (Spain); Cusano, F. [INAF-Osservatorio Astronomico di Bologna, Via Ranzani 1, I-40127 Bologna (Italy); Moerchen, M., E-mail: andrea@narit.or.th [European Southern Observatory, Casilla 19001, Santiago 19 (Chile)

2012-12-15T23:59:59.000Z

185

Organ doses for reference pediatric and adolescent patients undergoing computed tomography estimated by Monte Carlo simulation  

SciTech Connect

Purpose: To establish an organ dose database for pediatric and adolescent reference individuals undergoing computed tomography (CT) examinations by using Monte Carlo simulation. The data will permit rapid estimates of organ and effective doses for patients of different age, gender, examination type, and CT scanner model. Methods: The Monte Carlo simulation model of a Siemens Sensation 16 CT scanner previously published was employed as a base CT scanner model. A set of absorbed doses for 33 organs/tissues normalized to the product of 100 mAs and CTDI{sub vol} (mGy/100 mAs mGy) was established by coupling the CT scanner model with age-dependent reference pediatric hybrid phantoms. A series of single axial scans from the top of head to the feet of the phantoms was performed at a slice thickness of 10 mm, and at tube potentials of 80, 100, and 120 kVp. Using the established CTDI{sub vol}- and 100 mAs-normalized dose matrix, organ doses for different pediatric phantoms undergoing head, chest, abdomen-pelvis, and chest-abdomen-pelvis (CAP) scans with the Siemens Sensation 16 scanner were estimated and analyzed. The results were then compared with the values obtained from three independent published methods: CT-Expo software, organ dose for abdominal CT scan derived empirically from patient abdominal circumference, and effective dose per dose-length product (DLP). Results: Organ and effective doses were calculated and normalized to 100 mAs and CTDI{sub vol} for different CT examinations. At the same technical setting, dose to the organs, which were entirely included in the CT beam coverage, were higher by from 40 to 80% for newborn phantoms compared to those of 15-year phantoms. An increase of tube potential from 80 to 120 kVp resulted in 2.5-2.9-fold greater brain dose for head scans. The results from this study were compared with three different published studies and/or techniques. First, organ doses were compared to those given by CT-Expo which revealed dose differences up to several-fold when organs were partially included in the scan coverage. Second, selected organ doses from our calculations agreed to within 20% of values derived from empirical formulae based upon measured patient abdominal circumference. Third, the existing DLP-to-effective dose conversion coefficients tended to be smaller than values given in the present study for all examinations except head scans. Conclusions: A comprehensive organ/effective dose database was established to readily calculate doses for given patients undergoing different CT examinations. The comparisons of our results with the existing studies highlight that use of hybrid phantoms with realistic anatomy is important to improve the accuracy of CT organ dosimetry. The comprehensive pediatric dose data developed here are the first organ-specific pediatric CT scan database based on the realistic pediatric hybrid phantoms which are compliant with the reference data from the International Commission on Radiological Protection (ICRP). The organ dose database is being coupled with an adult organ dose database recently published as part of the development of a user-friendly computer program enabling rapid estimates of organ and effective dose doses for patients of any age, gender, examination types, and CT scanner model.

Lee, Choonsik; Kim, Kwang Pyo; Long, Daniel J.; Bolch, Wesley E. [Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institute of Health, Bethesda, Maryland 20852 (United States); Department of Nuclear Engineering, Kyung Hee University, Gyeonggi-do, 446906 (Korea, Republic of); J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida 32611 (United States)

2012-04-15T23:59:59.000Z

186

Population Structure, Association Mapping of Economic Traits and Landscape Genomics of East Texas Loblolly Pine ( Pinus taeda L.)  

E-Print Network (OSTI)

Loblolly pine (Pinus taeda L.) is an ecologically and economically important southern pine, distributed across the southeastern United States. Its genetic improvement for breeding and deployment is a major goal of the Western Gulf Forest Tree Improvement Program (WGFTIP) hosted by the Texas A&M Forest Service. Rapid advances in genomics and molecular marker technology have created potential for application of Marker Assisted Selection (MAS) and Genomic Selection (GS) for accelerated breeding in forest trees. First-generation selection (FGS) and second- generation selection (SGS) breeding populations of loblolly pine from east Texas were studied to estimate the genetic diversity, population structure, linkage disequilibrium (LD), signatures of selection and association of breeding traits with genetic markers using a genome-wide panel of 4264 single nucleotide polymorphisms (SNPs). Under- standing the genetic basis of local adaptation is crucial to disentangle the dynamics of gene flow, drift and selection and to address climate change. Bayesian mixed linear models and logistic regression were used to associate SNP variation with geography, climate, aridity and growth season length and markers with strong correlations were investigated for biological functions. Relatively high levels of observed (Ho = 0.178–0.198) and expected (He = 0.180-0.198) heterozygosities were found in all populations. The amount of inbreeding was very low, and many populations exhibited a slight excess of heterozygotes. The population substructure was weak, but FST indicated more pronounced differentiation in the SGS populations. As expected for outcrossing natural populations, the genome-wide LD was low, but marker density was insufficient to deduce the decay rate. Numerous associations were found between various phenotypes and SNPs, but few remained significant after false positive correction. Signatures of diversifying and balancing selection were found in markers representing important biological functions. Strong correlations supported by Bayes factors were found between various environmental variables and several SNPs. Logistic regression found hundreds of significant marker-environment associations, but none remained significant after false-positive correction, which was likely too stringent and will require further investigation. Annotations of significant markers implicated them in crucial biological functions. These results present the first step in the application of MAS to the WGFTIP for loblolly pine genetic improvement and will contribute to the knowledgebase necessary for genomic selection technology. Results from environmental association study provide important information for designing breeding strategies to address climate change and for genetic conservation purposes.

Chhatre, Vikram E.

2013-05-01T23:59:59.000Z

187

Low-dose computed tomography image restoration using previous normal-dose scan  

Science Conference Proceedings (OSTI)

Purpose: In current computed tomography (CT) examinations, the associated x-ray radiation dose is of a significant concern to patients and operators. A simple and cost-effective means to perform the examinations is to lower the milliampere-seconds (mAs) or kVp parameter (or delivering less x-ray energy to the body) as low as reasonably achievable in data acquisition. However, lowering the mAs parameter will unavoidably increase data noise and the noise would propagate into the CT image if no adequate noise control is applied during image reconstruction. Since a normal-dose high diagnostic CT image scanned previously may be available in some clinical applications, such as CT perfusion imaging and CT angiography (CTA), this paper presents an innovative way to utilize the normal-dose scan as a priori information to induce signal restoration of the current low-dose CT image series. Methods: Unlike conventional local operations on neighboring image voxels, nonlocal means (NLM) algorithm utilizes the redundancy of information across the whole image. This paper adapts the NLM to utilize the redundancy of information in the previous normal-dose scan and further exploits ways to optimize the nonlocal weights for low-dose image restoration in the NLM framework. The resulting algorithm is called the previous normal-dose scan induced nonlocal means (ndiNLM). Because of the optimized nature of nonlocal weights calculation, the ndiNLM algorithm does not depend heavily on image registration between the current low-dose and the previous normal-dose CT scans. Furthermore, the smoothing parameter involved in the ndiNLM algorithm can be adaptively estimated based on the image noise relationship between the current low-dose and the previous normal-dose scanning protocols. Results: Qualitative and quantitative evaluations were carried out on a physical phantom as well as clinical abdominal and brain perfusion CT scans in terms of accuracy and resolution properties. The gain by the use of the previous normal-dose scan via the presented ndiNLM algorithm is noticeable as compared to a similar approach without using the previous normal-dose scan. Conclusions: For low-dose CT image restoration, the presented ndiNLM method is robust in preserving the spatial resolution and identifying the low-contrast structure. The authors can draw the conclusion that the presented ndiNLM algorithm may be useful for some clinical applications such as in perfusion imaging, radiotherapy, tumor surveillance, etc.

Ma, Jianhua; Huang, Jing; Feng, Qianjin; Zhang, Hua; Lu, Hongbing; Liang, Zhengrong; Chen, Wufan [Department of Biomedical Engineering, Southern Medical University, Guangzhou, Guangdong 510515, China and Department of Radiology, State University of New York, Stony Brook, New York 11794 (United States); Department of Biomedical Engineering, Southern Medical University, Guangzhou, Guangdong 510515 (China); Department of Biomedical Engineering, Fourth Military Medical University, Xi'An, Shanxi 710032 (China); Department of Radiology, State University of New York, Stony Brook, New York 11794 (United States); Department of Biomedical Engineering, Southern Medical University, Guangzhou, Guangdong 510515 (China)

2011-10-15T23:59:59.000Z

188

Reply to comment by J. Ganguly on Evaluation of thermobarometers for garnet peridotites'  

SciTech Connect

In the authors' 1984 and subsequent papers (Finnerty and Boyd, 1987; Finnerty, 1989) they evaluated more than 650 combinations of thermometers and barometers. Where possible they have used thermodynamic or mathematic formulations that authors have derived from their data. In cases where such formulations were either not provided or were incomplete, they have fitted data by the simplest possible procedures. Equation 9a of Lane and Ganguly (1980) requires calculation of the term X{sub Al{sub 2}O{sub 3}}{sup Opx} from analytical data in the form of weight-percent oxides. No procedure was given in their paper for calculation of this quantity. Different methods are required depending upon site occupancy models and upon whether the effects of components other than Mg, Al, and Si (MAS) are considered. Limiting their consideration to the MAS system, the authors tested alternate definitions of X{sub Al{sub 2}O{sub 3}}{sup Opx} by calculating P-T values for garnet peridotite xenoliths from northern Lesotho and comparing the estimates to those presented by Lane and Ganguly (1980, Fig. 5 LG80). When X{sub Al{sub 2}O{sub 3}}{sup Opx} was calculated as Al/(Al + 2Si), where the chemical symbols refer to the numbers of the respective cations calculated from the chemical analysis on a 6-oxygen basis, their estimates agreed with those in the Lane and Ganguly (1980) paper, insofar as could be determined by comparison with their Fig. 5. This formula was transferred into Program TEMPEST, and a plot generated with it was used as the basis for remarks in the text of the authors' paper. These remarks are correct, but an error was made in assembling the accompanying figures. A preliminary estimate calculated with the formula Al/(Al + Si) was inadvertently substituted for the correct figure and was included in their published paper (Fig. 4F). Pressure estimates in the invalid figure are low by about 10 kbar. The correct version of the original Fig. 4F is presented herein as Fig. 1.

Finnerty, A.A. (Balance Hydrologics, Inc., Berkeley, CA (United States)); Boyd, F.R. (Carnegie Institution of Washington, DC (United States))

1992-02-01T23:59:59.000Z

189

periodicrpp.dvi  

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

0 0 by D.E. Groom (LBNL), and E. Bergren. Atomic weights of stable elements are adapted from the Commission on Isotopic Abundances and Atomic Weights, "Atomic Weights of the Elements 2007," http://www.chem.qmul.ac.uk/iupac/AtWt/. The atomic number (top left) is the number of protons in the nucleus. The atomic mass (bottom) of a stable elements is weighted by isotopic abundances in the Earth's surface. If the element has no stable isotope, the atomic mass (in parentheses) of the most stable isotope currently known is given. In this case the mass is from http://www.nndc.bnl.gov/amdc/masstables/Ame2003/mass.mas03 and the longest-lived isotope is from www.nndc.bnl.gov/ensdf/za form.jsp. The exceptions are Th, Pa, and U, which do have characteristic terrestrial compositions. Atomic masses are relative to the mass of 12 C, defined to be exactly 12 unified atomic mass

190

regionalmaps  

Gasoline and Diesel Fuel Update (EIA)

Specific LNG Terminals Specific LNG Terminals Generic LNG Terminals Pacifi c (9) Moun tain (8) CA (12) AZ/N M (11) W. North Centr al (4) W. South Centr al (7) E. South Centr al (6) E. North Centr al (3) S. Atlan tic (5) FL (10) Mid. Atlan tic (2) New Engl. (1) W. Cana da E. Cana da MacK enzie Alask a Cana da Offsh ore and LNG Mexic o Baha mas Primary Flows Secondary Flows Pipeline Border Crossing Specific LNG Terminals Generic LNG Terminals Figure 6. Coal Supply Regions Source: Energy Information Administration. Office of Integrated Analysis and Forecasting WA ID OR CA NV UT TX OK AR MO LA MS AL GA FL TN SC NC KY VA WV WY CO SD ND MI MN WI IL IN OH MD PA NJ DE CT MA NH VT NY ME RI MT NE IA KS MI AZ NM 500 0 SCALE IN MILES APPALACHIA Northern Appalachia Central Appalachia Southern Appalachia INTERIOR NORTHERN GREAT PLAINS Eastern Interior Western Interior Gulf Lignite Dakota Lignite Western Montana

191

Oliver L. Phillips,  

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

73 a 387. 73 a 387. 1 Mudanças na Biomassa, Dinâmica e Composição da Floresta Amazônica, 1980 - 2002 Oliver L. Phillips, 1 Niro Higuchi, 2 Simone Vieira, 3 Timothy R. Baker, 1 Kuo-Jung Chao, 1 e Simon L. Lewis 1 O monitoramento de longo prazo de parcelas florestais distribuídas ao longo da Amazônia fornece uma poderosa forma de se quantificar os estoques e fluxos de biomassa e biodiversidade. Neste capítulo, examinamos as evidências de mudanças associadas à estrutura, dinâmica e composição funcional de florestas amazônicas maduras nas últimas décadas. As florestas maduras têm, como um todo, adquirido biomassa e apresentado dinâmica e crescimento acelerados, mas as questões sobre a persistência dessas mudanças de longo prazo permanecem. Em razão de o crescimento

192

Susan Trumbore Department of Earth System Science, University of California, Irvine, California, USA  

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

51 a 462 51 a 462 1 Dinâmica do Carbono do Solo Susan Trumbore Department of Earth System Science, University of California, Irvine, California, USA Plínio Barbosa de Camargo Laboratório de Ecologia Isotópica do CENA/USP, Piracicaba, Brasil A quantidade de carbono orgânico (C) estocada na camada superior de 1m de solos minerais na Bacia Amazônica (~40 Pg C) representa 3% do estoque global estimado de carbono no solo. Acrescentando-se os estoques detríticos de C da superfície e carbono do solo a mais de um metro de profundidade, essa estimativa pode se quadriplicar. O potencial de resposta do carbono do solo da Amazônia às mudanças no uso da terra, clima ou composição atmosférica depende da forma e da dinâmica do carbono do solo. 30% de 10 cm do topo, mas >85% em

193

Carlos A. Nobre e José A. Marengo Centro de Ciência do Sistema Terrestre, Instituto Nacional de Pesquisas Espaciais  

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

5 a 147. 5 a 147. 1 Entendendo o Clima da Amazônia: Avanço do LBA Carlos A. Nobre e José A. Marengo Centro de Ciência do Sistema Terrestre, Instituto Nacional de Pesquisas Espaciais São José dos Campos, Brasil Paulo Artaxo Instituto de Física, Universidade de São Paulo, São Paulo, Brasil A Amazônia desempenha um papel importante no funcionamento do clima da Terra. Ela atua como uma das fontes indispensáveis de calor para a atmosfera global por meio da evaporação do vapor d'água na superfície e liberação de calor na média e alta troposfera pelo calor latente de condensação em nuvens convectivas tropicais. A evaporação ao longo do ano é de aproximadamente 3 a 3,5 mm d -1 . Mas, em regiões de savana na fronteira com a floresta amazônica, a evaporação

194

regionalmaps  

Gasoline and Diesel Fuel Update (EIA)

LNG Imports LNG Imports Pacifi c (9) Moun tain (8) CA (12) AZ/N M (11) W. North Centr al (4) W. South Centr al (7) E. South Centr al (6) E. North Centr al (3) S. Atlan tic (5) FL (10) Mid. Atlan tic (2) New Engl. (1) W. Cana da E. Cana da MacK enzie Alask a Cana da Offsh ore and LNG Mexic o Baha mas Primary Flows Secondary Flows Pipeline Border Crossing Figure 6. Coal Supply Regions Source: Energy Information Administration. Office of Integrated Analysis and Forecasting WA ID OR CA NV UT TX OK AR MO LA MS AL GA FL TN SC NC KY VA WV WY CO SD ND MI MN WI IL IN OH MD PA NJ DE CT MA NH VT NY ME RI MT NE IA KS MI AZ NM 500 0 SCALE IN MILES APPALACHIA Northern Appalachia Central Appalachia Southern Appalachia INTERIOR NORTHERN GREAT PLAINS Eastern Interior Western Interior Gulf Lignite Dakota Lignite Western Montana Wyoming, Northern Powder River Basin Wyoming, Southern Powder River Basin Western Wyoming

195

Observation of the Top Quark  

E-Print Network (OSTI)

The D collaboration reports on a search for the Standard Model top quark in pp collisions at p s = 1:8 TeV at the Fermilab Tevatron, with an integrated luminosity of approximately 50 pb \\Gamma1 . We have searched for t t production in the dilepton and single-lepton decay channels, with and without tagging of b-quark jets. We observed 17 events with an expected background of 3:8 \\Sigma 0:6 events. The probability for an upward fluctuation of the background to produce the observed signal is 2 \\Theta 10 \\Gamma6 (equivalent to 4.6 standard deviations). The kinematic properties of the excess events are consistent with top quark decay. We conclude that we have observed the top quark and measure its mass to be 199 +19 \\Gamma21 (stat.) \\Sigma22 (syst.) GeV/c 2 and its production cross section to be 6:4 \\Sigma 2:2 pb. Typeset using REVT E X 3 In the Standard Model (SM), the top quark is the weak isospin partner of the b quark. The D collaboration published a lower limit on the mas...

Abachi Abbott Abolins

1995-01-01T23:59:59.000Z

196

Mutual Valuations Between Agents And Their Coalitions  

E-Print Network (OSTI)

Introduction The notions of norms, coalitions and agents raise a lot of interesting questions. What makes agents form coalitions? When are new agents in a MAS considered to be members in a coalition? And when does a coalition think it might be time for certain agents to leave? Can we design agents in such a way that they will continuously improve and strengthen the coalitions that they are part of? Does the size of the coalition matter? Not all of these questions will be treated here, but we will try to provide some thoughts on things such as the value of a coalition having a certain agent as a member, continuous degrees of membership, and whether cheating is possible in such models. The question of whether to cooperate or not is not new. People in the area of game theory, e.g. Lloyd Shapley discussed the matter of values and alternative costs in n-person games already in the fifties. 1 He argued that the value of a cooperating agent is directly associated with the alternative cost

Stefan J. Johansson

1999-01-01T23:59:59.000Z

197

An overlooked brown dwarf neighbour (T7.5 at d~5pc) of the Sun and two further T dwarfs at about 10pc  

E-Print Network (OSTI)

Although many new brown dwarf (BD) neighbours have been recently discovered thanks to new sky surveys in the mid- and near-infrared (MIR, NIR), their numbers are still more than five times lower than those of stars in the same volume. We aim at detecting and classifying new BDs to eventually complete their census in the immediate Solar neighbourhood. We combine multi-epoch data from sky surveys at different wavelengths to detect BD neighbours of the Sun by their high proper motion (HPM). We concentrate at relatively bright MIR (w2<13.5) BD candidates from WISE expected to be so close to the Sun that they may also be seen in older NIR (2MASS, DENIS) or even red optical (SDSS i- and z-band, SSS I-band) surveys. With low-resolution NIR spectroscopy we classify the new BDs and estimate their distances and velocities. We have discovered the HPM (pm~470mas/yr) T7.5 dwarf WISE J0521+1025 at d=5.0+-1.3pc from the Sun, and two early-T dwarfs WISE J0457-0207 (T2) and WISE J2030+0749 (T1.5) with proper motions of ~12...

Bihain, Gabriel; Storm, Jesper; Schnurr, Olivier

2013-01-01T23:59:59.000Z

198

UKIDSS detections of cool brown dwarfs - proper motions of 14 known $>$T5 dwarfs and discovery of three new T5.5-T6 dwarfs  

E-Print Network (OSTI)

AIMS: We contribute to improving the census of cool brown dwarfs (late-T and Y dwarfs) in the immediate solar neighbourhood. METHODS: By combining near-infrared (NIR) data of UKIDSS with mid-infrared WISE and other available NIR (2MASS) and red optical (SDSS $z$-band) multi-epoch data we detect high proper motion (HPM) objects with colours typical of late spectral types ($>$T5). We use NIR low-resolution spectroscopy for the classification of new candidates. RESULTS: We determined new proper motions for 14 known T5.5-Y0 dwarfs, many of them being significantly ($>$2-10 times) more accurate than previous ones. We detected three new candidates, ULAS J0954+0623, ULAS J1152+0359, and ULAS J1204-0150, by their HPMs and colours. Using previously published and new UKIDSS positions of the known nearby T8 dwarf WISE J0254+0223 we improved its trigonometric parallax to 165$\\pm$20 mas. For the three new objects we obtained NIR spectroscopic follow-up with LBT/LUCIFER classifying them as T5.5 and T6 dwarfs. With their es...

Scholz, Ralf-Dieter; Schnurr, Olivier; Storm, Jesper

2012-01-01T23:59:59.000Z

199

Cr(VI) adsorption on functionalized amorphous and mesoporous silica from aqueous and non-aqueous media  

Science Conference Proceedings (OSTI)

A mesoporous silica (SBA-15) and amorphous silica (SG) have been chemically modified with 2-mercaptopyridine using the homogeneous route. This synthetic route involved the reaction of 2-mercaptopyridine with 3-chloropropyltriethoxysilane prior to immobilization on the support. The resulting material has been characterized by powder X-ray diffraction, nitrogen gas sorption, FT-IR and MAS NMR spectroscopy, thermogravimetry and elemental analysis. The solid was employed as a Cr(VI) adsorbent from aqueous and non-aqueous solutions at room temperature. The effect of several variables (stirring time, pH, metal concentration and solvent polarity) has been studied using the batch technique. The results indicate that under the optimum conditions, the maximum adsorption value for Cr(VI) was 1.83 {+-} 0.03 mmol/g for MP-SBA-15, whereas the adsorption capacity of the MP-SG was 0.86 {+-} 0.02 mmol/g. On the basis of these results, it can be concluded that it is possible to modify chemically SBA-15 and SG with 2-mercaptopyridine and to use the resulting modified silicas as effective adsorbents for Cr(VI)

Perez-Quintanilla, Damian [Departamento de Quimica Inorganica y Analitica, E.S.C.E.T, Universidad Rey Juan Carlos, C/Tulipan s/n, 28933 Mostoles, Madrid (Spain)]. E-mail: damian.perez@urjc.es; Hierro, Isabel del [Departamento de Quimica Inorganica y Analitica, E.S.C.E.T, Universidad Rey Juan Carlos, C/Tulipan s/n, 28933 Mostoles, Madrid (Spain); Fajardo, Mariano [Departamento de Quimica Inorganica y Analitica, E.S.C.E.T, Universidad Rey Juan Carlos, C/Tulipan s/n, 28933 Mostoles, Madrid (Spain); Sierra, Isabel [Departamento de Quimica Inorganica y Analitica, E.S.C.E.T, Universidad Rey Juan Carlos, C/Tulipan s/n, 28933 Mostoles, Madrid (Spain)]. E-mail: isabel.sierra@urjc.es

2007-08-07T23:59:59.000Z

200

NAVY PRECISION OPTICAL INTERFEROMETER OBSERVATIONS OF THE EXOPLANET HOST {kappa} CORONAE BOREALIS AND THEIR IMPLICATIONS FOR THE STAR'S AND PLANET'S MASSES AND AGES  

SciTech Connect

We used the Navy Precision Optical Interferometer to measure the limb-darkened angular diameter of the exoplanet host star {kappa} CrB and obtained a value of 1.543 {+-} 0.009 mas. We calculated its physical radius (5.06 {+-} 0.04 R{sub Sun }) and used photometric measurements from the literature with our diameter to determine {kappa} CrB's effective temperature (4788 {+-} 17 K) and luminosity (12.13 {+-} 0.09 L{sub Sun }). We then placed the star on an Hertzsprung-Russell diagram to ascertain the star's age (3.42{sup +0.32}{sub -0.25} Gyr) and mass (1.47 {+-} 0.04 M{sub Sun }) using a metallicity of [Fe/H] = +0.15. With this mass, we calculated the system's mass function with the orbital elements from a variety of sources, which produced a range of planetary masses: m{sub p}sin i = 1.61-1.88 M{sub Jup}. We also updated the extent of the habitable zone for the system using our new temperature.

Baines, Ellyn K.; Armstrong, J. Thomas [Remote Sensing Division, Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, DC 20375 (United States); Van Belle, Gerard T., E-mail: ellyn.baines@nrl.navy.mil [Lowell Observatory, Flagstaff, AZ 86001 (United States)

2013-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "mas mas mas" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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201

An extremely wide and very low-mass pair with common proper motion. Is it representative of a nearby halo stream?  

E-Print Network (OSTI)

(abridged) We describe the discovery of an extremely wide pair of low-mass stars with a common large proper motion and discuss their possible membership in a Galactic halo stream crossing the Solar neighbourhood. (...) The late-type (M7) dwarf SSSPM J2003$-$4433 and the ultracool subdwarf SSSPM J1930$-$4311 (sdM7) sharing the same very large proper motion of about 860 mas/yr were found in the same sky region with an angular separation of about 6\\degr. From the comparison with other high proper motion catalogues we have estimated the probability of a chance alignment of the two new large proper motions to be less than 0.3%. From the individually estimated spectroscopic distances of about $38^{+10}_{-7}$ pc and $72^{+21}_{-16}$ pc, respectively for the M7 dwarf and the sdM7 subdwarf, and in view of the accurate agreement in their large proper motions we assume a common distance of about 50 pc and a projected physical separation of about 5 pc. The mean heliocentric space velocity of the pair $(U,V,W)=(-232, -170...

Scholz, R -D; Lodieu, N; McCaughrean, M J

2008-01-01T23:59:59.000Z

202

On the Criticality Safety of Transuranic Sodium Fast Reactor Fuel Transport Casks  

SciTech Connect

This work addresses the neutronic performance and criticality safety issues of transport casks for fuel pertaining to low conversion ratio sodium cooled fast reactors, conventionally known as Advanced Burner Reactors. The criticality of a one, three, seven and 19-assembly cask capacity is presented. Both dry “helium” and flooded “water” filled casks are considered. No credit for fuel burnup or fission products was assumed. As many as possible of the conservatisms used in licensing light water reactor universal transport casks were incorporated into this SFR cask criticality design and analysis. It was found that at 7-assemblies or more, adding moderator to the SFR cask increases criticality margin. Also, removal of MAs from the fuel increases criticality margin of dry casks and takes a slight amount of margin away for wet casks. Assuming credit for borated fuel tube liners, this design analysis suggests that as many as 19 assemblies can be loaded in a cask if limited purely by criticality safety. If no credit for boron is assumed, the cask could possibly hold seven assemblies if low conversion ratio fast reactor grade fuel and not breeder reactor grade fuel is assumed. The analysis showed that there is a need for new cask designs for fast reactors spent fuel transportation. There is a potential of modifying existing transportation cask design as the starting point for fast reactor spent fuel transportation.

Samuel Bays; Ayodeji Alajo

2010-05-01T23:59:59.000Z

203

Solid-State Selective 13C Excitation and Spin Diffusion NMR to Resolve Spatial Dimensions in Plant Cell Walls  

Science Conference Proceedings (OSTI)

The average spatial dimensions between major biopolymers within the plant cell wall can be resolved using a solid-state NMR technique referred to as a {sup 13}C cross-polarization (CP) SELDOM (selectively by destruction of magnetization) with a mixing time delay for spin diffusion. Selective excitation of specific aromatic lignin carbons indicates that lignin is in close proximity to hemicellulose followed by amorphous and finally crystalline cellulose. {sup 13}C spin diffusion time constants (T{sub SD}) were extracted using a two-site spin diffusion theory developed for {sup 13}C nuclei under magic angle spinning (MAS) conditions. These time constants were then used to calculate an average lower-limit spin diffusion length between chemical groups within the plant cell wall. The results on untreated {sup 13}C enriched corn stover stem reveal that the lignin carbons are, on average, located at distances {approx}0.7-2.0 nm from the carbons in hemicellulose and cellulose, whereas the pretreated material had larger separations.

Foston, M.; Katahira, R.; Gjersing, E.; Davis, M. F.; Ragauskas, A. J.

2012-02-15T23:59:59.000Z

204

RADIO SYNCHROTRON EMISSION FROM A BOW SHOCK AROUND THE GAS CLOUD G2 HEADING TOWARD THE GALACTIC CENTER  

Science Conference Proceedings (OSTI)

A dense ionized cloud of gas has been recently discovered to be moving directly toward the supermassive black hole, Sgr A*, at the Galactic center. In 2013 June, at the pericenter of its highly eccentric orbit, the cloud will be approximately 3100 Schwarzschild radii from the black hole and will move supersonically through the ambient hot gas with a velocity of v{sub p} Almost-Equal-To 5400 km s{sup -1}. A bow shock is likely to form in front of the cloud and could accelerate electrons to relativistic energies. We estimate via particle-in-cell simulations the energy distribution of the accelerated electrons and show that the non-thermal synchrotron emission from these electrons might exceed the quiescent radio emission from Sgr A* by a factor of several. The enhanced radio emission should be detectable at GHz and higher frequencies around the time of pericentric passage and in the following months. The bow shock emission is expected to be displaced from the quiescent radio emission of Sgr A* by {approx}33 mas. Interferometric observations could resolve potential changes in the radio image of Sgr A* at wavelengths {approx}< 6 cm.

Narayan, Ramesh; Sironi, Lorenzo [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Oezel, Feryal [Department of Astronomy, University of Arizona, 933 N. Cherry Ave., Tucson, AZ 85721 (United States)

2012-10-01T23:59:59.000Z

205

MOA-2010-BLG-477Lb: constraining the mass of a microlensing planet from microlensing parallax, orbital motion and detection of blended light  

E-Print Network (OSTI)

Microlensing detections of cool planets are important for the construction of an unbiased sample to estimate the frequency of planets beyond the snow line, which is where giant planets are thought to form according to the core accretion theory of planet formation. In this paper, we report the discovery of a giant planet detected from the analysis of the light curve of a high-magnification microlensing event MOA-2010-BLG-477. The measured planet-star mass ratio is $q=(2.181\\pm0.004)\\times 10^{-3}$ and the projected separation is $s=1.1228\\pm0.0006$ in units of the Einstein radius. The angular Einstein radius is unusually large $\\theta_{\\rm E}=1.38\\pm 0.11$ mas. Combining this measurement with constraints on the "microlens parallax" and the lens flux, we can only limit the host mass to the range $0.13

Bachelet, E; Han, C; Fouqué, P; Gould, A; Menzies, J W; Beaulieu, J -P; Bennett, D P; Bond, I A; Dong, Subo; Heyrovský, D; Marquette, J B; Marshall, J; Skowron, J; Street, R A; Sumi, T; Udalski, A; Abe, L; Agabi, K; Albrow, M D; Allen, W; Bertin, E; Bos, M; Bramich, D M; Chavez, J; Christie, G W; Cole, A A; Crouzet, N; Dieters, S; Dominik, M; Drummond, J; Greenhill, J; Guillot, T; Henderson, C B; Hessman, F V; Horne, K; Hundertmark, M; Johnson, J A; Jørgensen, U G; Kandori, R; Liebig, C; Mékarnia, D; McCormick, J; Moorhouse, D; Nagayama, T; Nataf, D; Natusch, T; Nishiyama, S; Rivet, J -P; Sahu, K C; Shvartzvald, Y; Thornley, G; Tomczak, A R; Tsapras, Y; Yee, J C; Batista, V; Bennett, C S; Brillant, S; Caldwell, J A R; Cassan, A; Corrales, E; Coutures, C; Prester, D Dominis; Donatowicz, J; Kubas, D; Martin, R; Williams, A; Zub, M; de Almeida, L Andrade; DePoy, D L; Gaudi, B S; Hung, L -W; Jablonski, F; Kaspi, S; Klein, N; Lee, C -U; Lee, Y; Koo, J -R; Maoz, D; Muñoz, J A; Pogge, R W; Polishook, D; Shporer, A; Abe, F; Botzler, C S; Chote, P; Freeman, M; Fukui, A; Furusawa, K; Harris, P; Itow, Y; Kobara, S; Ling, C H; Masuda, K; Matsubara, Y; Miyake, N; Ohmori, K; Ohnishi, K; Rattenbury, N J; Saito, To; Sullivan, D J; Suzuki, D; Sweatman, W L; Tristram, P J; Wada, K; Yock, P C M; Szyma?ski, M K; Soszy?ski, I; Kubiak, M; Poleski, R; Ulaczyk, K; Pietrzy?ski, G; Wyrzykowski, ?; Kains, N; Snodgrass, C; Steele, I A; Alsubai, K A; Bozza, V; Browne, P; Burgdorf, M J; Novati, S Calchi; Dodds, P; Dreizler, S; Finet, F; Gerner, T; Hardis, S; Harpsøe, K; Hinse, T C; Kerins, E; Mancini, L; Mathiasen, M; Penny, M T; Proft, S; Rahvar, S; Ricci, D; Scarpetta, G; Schäfer, S; Schönebeck, F; Southworth, J; Surdej, J; Wambsganss, J

2012-01-01T23:59:59.000Z

206

Characterizing Lenses and Lensed Stars of High-Magnification Gravitational Microlensing Events With Lenses Passing Over Source Stars  

E-Print Network (OSTI)

We present the analysis of the light curves of 9 high-magnification gravitational microlensing events with lenses passing over source stars, including OGLE-2004-BLG-254, MOA-2007-BLG-176, MOA-2007-BLG-233/OGLE-2007-BLG-302, MOA-2009-BLG-174, MOA-2010-BLG-436, MOA-2011-BLG-093, MOA-2011-BLG-274, OGLE-2011-BLG-0990/MOA-2011-BLG-300, and OGLE-2011-BLG-1101/MOA-2011-BLG-325. For all events, we measure the linear limb-darkening coefficients of the surface brightness profile of source stars by measuring the deviation of the light curves near the peak affected by the finite-source effect. For 8 events, we measure the Einstein radii and the lens-source relative proper motions. Among them, 6 events (OGLE-2004-BLG-254, MOA-2007-BLG-176, MOA-2007-BLG-233/OGLE-2007-BLG-302, MOA-2011-BLG-093, MOA-2011-BLG-274, and OGLE-2011-BLG-0990/MOA-2011-BLG-300) are found to have Einstein radii less than 0.2 mas, making the lenses candidates of very low-mass stars or brown dwarfs. For MOA-2011-BLG-274, especially, the small Einstein ...

Choi, J -Y; Park, S -Y; Han, C; Gould, A; Sumi, T; Udalski, A; Beaulieu, J -P; Street, R; Dominik, M; Allen, W; Bos, M; Christie, G W; Depoy, D L; Dong, S; Drummond, J; Gal-Yam, A; Gaudi, B S; Henderson, C B; Hung, L -W; Janczak, J; Lee, C -U; Mallia, F; Maury, A; McCormick, J; McGregor, D; Monard, L A G; Moorhouse, D; Muñoz, J A; Natusch, T; Nelson, C; Park, B -G; Pogge, R W; Tan, T -G "TG"; Thornley, G; Yee, J C; Abe, F; Barnard, E; Baudry, J; Bennett, D P; Bond, I A; Botzler, C S; Freeman, M; Fukui, A; Furusawa, K; Hayashi, F; Hearnshaw, J B; Hosaka, S; Itow, Y; Kamiya, K; Kilmartin, P M; Kobara, S; Korpela, A; Lin, W; Ling, C H; Makita, S; Masuda, K; Matsubara, Y; Miyake, N; Muraki, Y; Nagaya, M; Nishimoto, K; Ohnishi, K; Okumura, T; Omori, K; Perrott, Y C; Rattenbury, N; Saito, To; Skuljan, L; Sullivan, D J; Suzuki, D; Suzuki, K; Sweatman, W L; Takino, S; Tristram, P J; Wada, K; Yock, P C M; Szyma?ski, M K; Kubiak, M; Pietrzy?ski, G; Soszy?ski, I; Poleski, R; Ulaczyk, K; Wyrzykowski, ?; Koz?owski, S; Pietrukowicz, P; Albrow, M D; Bachelett, E; Batista, V; Bennett, C; Bowens-Rubin, R; Brillant, S; Cassan, A; Cole, A; Corrales, E; Coutures, Ch; Dieters, S; Prester, D Dominis; Donatowicz, J; Fouqué, P; Greenhill, J; Kane, S R; Menzies, J; Sahu, K C; Wambsganss, J; Williams, A; Zub, M; Allan, A; Bramich, D M; Browne, P; Clay, N; Fraser, S; Horne, K; Kains, N; Mottram, C; Snodgrass, C; Steele, I; Tsapras, Y; Alsubai, K A; Bozza, V; Burgdorf, M J; Novati, S Calchi; Dodds, P; Dreizler, S; Finet, F; Gerner, T; Glitrup, M; Grundahl, F; Hardis, S; Harpsøe, K; Hinse, T C; Hundertmark, M; Jørgensen, U G; Kerins, E; Liebig, C; Maier, G; Mancini, L; Mathiasen, M; Penny, M T; Proft, S; Rahvar, S; Ricci, D; Scarpetta, G; Schäfer, S; Schönebeck, F; Skottfelt, J; Surdej, J; Southworth, J; Zimmer, F

2011-01-01T23:59:59.000Z

207

XRD and NMR investigation of Ti-compound formation in solution-doping of sodium aluminum hydrides: Solubility of Ti in NaAlH4 crystals grown in THF  

DOE Green Energy (OSTI)

Sodium aluminum hydrides have gained attention due to their high hydrogen weight percent (5.5% ideal) compared to interstitial hydrides, and as a model for hydrides with even higher hydrogen weight fraction. The purpose of this paper is to investigate the Ti-compounds that are formed under solution-doping techniques, such as wet doping in solvents such as tetrahydrofuran (THF). Compound formation in Ti-doped sodium aluminum hydrides is investigated using x-ray diffraction (XRD) and magic angle spinning (MAS) nuclear magnetic resonance (NMR). We present lattice parameter measurements of crushed single crystals, which were exposed to Ti during growth. Rietveld refinements indicate no lattice parameter change and thus no solubility for Ti in NaAlH{sub 4} by this method of exposure. In addition, x-ray diffraction data indicate that no Ti substitutes in NaH, the final decomposition product for the alanate. Reaction products of completely reacted (33.3 at. %-doped) samples that were solvent-mixed or mechanically milled are investigated. Formation of TiAl{sub 3} is observed in mechanically milled materials, but not solution mixed samples, where bonding to THF likely stabilizes Ti-based nano-clusters. The Ti in these clusters is activated by mechanical milling.

Majzoub, E H; Herberg, J L; Stumpf, R; Spangler, S; Maxwell, R S

2004-08-26T23:59:59.000Z

208

Parallel Index and Query for Large Scale Data Analysis  

SciTech Connect

Modern scientific datasets present numerous data management and analysis challenges. State-of-the-art index and query technologies are critical for facilitating interactive exploration of large datasets, but numerous challenges remain in terms of designing a system for process- ing general scientific datasets. The system needs to be able to run on distributed multi-core platforms, efficiently utilize underlying I/O infrastructure, and scale to massive datasets. We present FastQuery, a novel software framework that address these challenges. FastQuery utilizes a state-of-the-art index and query technology (FastBit) and is designed to process mas- sive datasets on modern supercomputing platforms. We apply FastQuery to processing of a massive 50TB dataset generated by a large scale accelerator modeling code. We demonstrate the scalability of the tool to 11,520 cores. Motivated by the scientific need to search for inter- esting particles in this dataset, we use our framework to reduce search time from hours to tens of seconds.

Chou, Jerry; Wu, Kesheng; Ruebel, Oliver; Howison, Mark; Qiang, Ji; Prabhat,; Austin, Brian; Bethel, E. Wes; Ryne, Rob D.; Shoshani, Arie

2011-07-18T23:59:59.000Z

209

Analysis of Severe Accident Scenarios and Proposals for Safety Improvements for ADS Transmuters with Dedicated Fuel  

SciTech Connect

So-called dedicated fuels will be utilized to obtain maximum transmutation and incineration rates of minor actinides (MAs) in accelerator-driven systems (ADSs). These fuels are characterized by a high-MA content and the lack of the classical fertile materials such as {sup 238}U or {sup 232}Th. Dedicated fuels still have to be developed; however, programs are under way for their fabrication, irradiation, and testing. In Europe, mainly the oxide route is investigated and developed. A dedicated core will contain multiple 'critical' fuel masses, resulting in a certain recriticality potential under core degradation conditions. The use of dedicated fuels may also lead to strong deterioration of the safety parameters of the reactor core, such as, e.g., the void worth, Doppler or the kinetics quantities, neutron generation time, and {beta}{sub eff}. Critical reactors with this kind of fuel might encounter safety problems, especially under severe accident conditions. For ADSs, it is assumed that because of the subcriticality of the system, the poor safety features of such fuels could be coped with. Analyses reveal some safety problems for ADSs with dedicated fuels. Additional inherent and passive safety measures are proposed to achieve the required safety level. A safety strategy along the lines of a defense approach is presented where these measures can be integrated. The ultimate goal of these measures is to eliminate any mechanistic severe accident scenario and the potential for energetics.

Maschek, Werner [Forschungszentrum Karlsruhe Institute for Nuclear and Energy Technologies (Germany); Rineiski, Andrei [Forschungszentrum Karlsruhe Institute for Nuclear and Energy Technologies (Germany); Flad, Michael [Forschungszentrum Karlsruhe Institute for Nuclear and Energy Technologies (Germany); Morita, Koji [Kyushu University Institute of Environmental Systems (Japan); Coste, Pierre [Commissariat a l'Energie Atomique CE Grenoble (France)

2003-02-15T23:59:59.000Z

210

Multi Agent System to Optimize Comfort and Energy Flows in the Built Environment  

E-Print Network (OSTI)

This paper discusses the control of building energy comfort management systems led by the economic movement within the energy market resulting in different prices. This new generation of building management systems focuses on the application of multi-agent systems for autonomous flexible operation of building services systems to obtain overall improvement energy efficiency and comfort. Multi-agent systems have proven to be successful in many applications to detach the timely interdependencies between systems and applications and come to a decentralize approach. In this study a multi-agent system (MAS) is developed to control and manage building services systems. A case study on an existing building system pointed out that energy consumption is reduced of a central air conditioning unit and local heating and cooling units with help of the proposed market driven multi-agent system, while maintaining comfort within the bands of user preferences. Furthermore it can be concluded that the system adapts to the dynamic changing situation and amount of momentary available resources.

Pennings, L. W.; Houten, M. A.; Boxem, G.; Zeiler, W.

2010-01-01T23:59:59.000Z

211

NPOI Observations of the Exoplanet Host kappa Coronae Borealis and Their Implications for the Star's and Planet's Masses and Ages  

E-Print Network (OSTI)

We used the Navy Precision Optical Interferometer to measure the limb-darkened angular diameter of the exoplanet host star kappa CrB and obtained a value of 1.543 +/- 0.009 mas. We calculated its physical radius (5.06 +/- 0.04 R_Sun) and used photometric measurements from the literature with our diameter to determine kappa CrB's effective temperature (4788 +/- 17 K) and luminosity (12.13 +/- 0.09 L_Sun). We then placed the star on an H-R diagram to ascertain the star's age (3.42 +0.32/-0.25 Gyr) and mass (1.47 +/- 0.04 M_Sun) using a metallicity of [Fe/H] = +0.15. With this mass, we calculated the system's mass function with the orbital elements from a variety of sources, which produced a range of planetary masses: m_p sin i = 1.61 to 1.88 M_Jup. We also updated the extent of the habitable zone for the system using our new temperature.

Baines, Ellyn K; van Belle, Gerard T

2013-01-01T23:59:59.000Z

212

Assessment of materials for use in a solar ceramic receiver for chemical process heat  

DOE Green Energy (OSTI)

Candidate ceramic matrials were evaluated on the basis of two potential temperature operating regimes: 600 to 1300/sup 0/C (1100 to 2400/sup 0/F) and 1300 to 2200/sup 0/C (2400 to 4000/sup 0/F). Discussion of properties important to the proposed application includes thermal shock resistance, tensile strength, creep resistance, oxidation resistance, vaporization rate, chemical inertness to process reactants and products, cost, and fabricability. Many ceramic materials were considered for the 600 to 1300/sup 0/C operating regime. On the basis of a significant data base on tensile strength, thermal expansion, thermal conductivity, fabricability, and stability, the leading candidates were identified, in decreasing order of preference, as (1) silicon carbide, (2) magnesium oxide, (3) cordierite (2MgO.2Al/sub 2/O/sub 3/.5SiO/sub 2/) known as MAS (4) aluminum oxide, (5) silicon nitride, (6) silicon aluminum oxynitrides (Si/sub w/Al/sub x/N/sub y/O/sub z/) known as sialons, and (7) beryllium oxide. Selection of candidate materials for the 1300 to 2200/sup 0/C regime was restricted because of the insufficient property data and operational experience on key performance parameters. Leading candidates were identified, in decreasing ordr of preference, as (1) zirconium oxide (Y/sub 2/O/sub 3/) stabilized), (2) magnesium oxide, (3) cerium oxide, (4) beryllium oxide, (5) calcium oxide, and (6) thorium and uranium oxide.

Tennery, V.J.; Weber, G.W.

1979-02-01T23:59:59.000Z

213

Coal liquefaction process streams characterization and evaluation  

DOE Green Energy (OSTI)

This study clearly demonstrated the usefulness of liquid- and solid-state {sup 13}C- and {sup 1}H-NMR for the examination of process-derived materials from direct coal liquefaction. The techniques can provide data not directly obtainable by other methods to examine the saturation of aromatic rings and to determine the modes of hydrogen utilization during coal liquefaction. In addition, these methods can be used to infer the extent of condensation and retrograde reactions occurring in the direct coal liquefaction process. Five NMR techniques were employed. Solid-state {sup 13}C-NMR measurements were made using the Cross Polarization Magic Angle Spinning (CP/MAS) and Single Pulse (SP) techniques. Solid-state {sup 1}H-NMR measurements were made using the technique of Combined Rotation and Multiple-Pulse spectroscopy (CRAMPS). Conventional liquid-state {sup 12}C- and {sup 1}H-NMR techniques were employed as appropriate. Interpretation of the NMR data, once obtained, is relatively straightforward. Combined with other information, such as elemental analyses and process conversion data, the NMR data prove to be a powerful tool for the examination of direct coal liquefaction process-derived material. Further development and more wide-spread application of this analytical method as a process development tool is justified on the basis of these results.

Miknis, F.P. (Western Research Inst., Laramie, WY (United States))

1991-11-01T23:59:59.000Z

214

Coal liquefaction process streams characterization and evaluation. Solid-state NMR characterization of coal liquefaction products  

DOE Green Energy (OSTI)

This study clearly demonstrated the usefulness of liquid- and solid-state {sup 13}C- and {sup 1}H-NMR for the examination of process-derived materials from direct coal liquefaction. The techniques can provide data not directly obtainable by other methods to examine the saturation of aromatic rings and to determine the modes of hydrogen utilization during coal liquefaction. In addition, these methods can be used to infer the extent of condensation and retrograde reactions occurring in the direct coal liquefaction process. Five NMR techniques were employed. Solid-state {sup 13}C-NMR measurements were made using the Cross Polarization Magic Angle Spinning (CP/MAS) and Single Pulse (SP) techniques. Solid-state {sup 1}H-NMR measurements were made using the technique of Combined Rotation and Multiple-Pulse spectroscopy (CRAMPS). Conventional liquid-state {sup 12}C- and {sup 1}H-NMR techniques were employed as appropriate. Interpretation of the NMR data, once obtained, is relatively straightforward. Combined with other information, such as elemental analyses and process conversion data, the NMR data prove to be a powerful tool for the examination of direct coal liquefaction process-derived material. Further development and more wide-spread application of this analytical method as a process development tool is justified on the basis of these results.

Miknis, F.P. [Western Research Inst., Laramie, WY (United States)

1991-11-01T23:59:59.000Z

215

Orbit and Stellar Properties of the Young Triple V807 Tau  

E-Print Network (OSTI)

We present new orbital measurements of the pre-main sequence triple system, V807 Tau, using adaptive optics imaging at the Keck Observatory. We computed an orbit for the close pair, V807 Tau Ba-Bb, with a period of 12.312 +/- 0.058 years and a semi-major axis of 38.59 +/- 0.16 mas. By modeling the center of mass motion of the components in the close pair relative to the wide component, V807 Tau A, we measured a mass ratio of 0.843 +/- 0.050 for Bb/Ba. Combined with the total mass from the relative orbit, we derived individual masses of M_Ba = 0.564 +/- 0.018 (d/140 pc)^3 Msun and M_Bb = 0.476 +/- 0.017 (d/140 pc)^3 Msun at an average distance of 140 pc to the Taurus star forming region. We computed spectral energy distributions to determine the luminosities of the three components. We also measured their spectral types, effective temperatures, and rotational velocities based on spatially resolved spectra obtained at the Keck Observatory. If the rotational axes are aligned, then the projected rotational veloci...

Schaefer, G H; Simon, M; Zavala, R T

2012-01-01T23:59:59.000Z

216

Global 8.4-GHz VLBI observations of JVAS B0218+357  

E-Print Network (OSTI)

In this paper we present new observations of the gravitational lens system JVAS B0218+357 made with a global VLBI network at a frequency of 8.4 GHz. Our maps have an rms noise of 30 microJy/beam and with these we have been able to image much of the extended structure of the radio jet in both the A and B images at high resolution (~1 mas). The main use of these maps will be to enable us to further constrain the lens model for the purposes of H0 determination. We are able to identify several sub-components common to both images with the expected parity reversal, including one which we identify as a counter-jet. We have not been successful in detecting either the core of the lensing galaxy or a third image. Using a model of the lensing galaxy we have back-projected both of the images to the source plane and find that they agree well. However, there are small, but significant, differences which we suggest may arise from multi-path scattering in the ISM of the lensing galaxy. We also find an exponent of the radial mass distribution of approximately 1.04, in agreement with lens modelling of published 15-GHz VLBI data. Polarisation maps of each image are presented which show that the distributions of polarisation across images A and B are different. We suggest that this results from Faraday rotation and associated depolarisation in the lensing galaxy.

A. D. Biggs; O. Wucknitz; R. W. Porcas; I. W. A. Browne; N. J. Jackson; S. Mao; P. N. Wilkinson

2002-09-10T23:59:59.000Z

217

Coal thermolysis modeling: The effect of cross-linking on the thermal decomposition of 1,3-diphenylpropane  

Science Conference Proceedings (OSTI)

In an effort to model the effects of restricted diffusion and cross-linking on the thermal decomposition of polymethylene units linking aromatic moieties in coal, a surface-attached, cross-linked 1,3-diphenylpropane has been synthesized through the condensation of p, p{prime}-HOPh(CH{sub 2}){sub 3}PhOH with a silica surface. Thermolysis of DPP at 375 C has been studied at a variety of surface coverages in which the fraction of diattached DPP varies from ca. 24 to 86% with complete diattachment not yet achieved. The influence of cross-linking and free phenolic functionality (Ph(CH{sub 2}){sub 3}PhOH) on the rate of decomposition and product distribution will be discussed and compared to the thermolysis of Ph(CH{sub 2}){sub 3}Ph as well as fluid phase DPP. Solid state CP/MAS {sup 13}C NMR will be used to prove the chemical composition and motional behavior of the substrate on the surface and their potential mechanistic impact.

Britt, P.F.; Buchanan, A.C. III.; Hagaman, E.W.; Biggs, C.A. (Oak Ridge National Lab., TN (United States))

1990-08-01T23:59:59.000Z

218

Extrinsic Radio Variability of JVAS/CLASS Gravitational Lenses  

E-Print Network (OSTI)

We present flux-ratio curves of the fold and cusp (i.e. close multiple) images of six JVAS/CLASS gravitational lens systems. The data were obtained over a period of 8.5 months in 2001 with the Multi-Element Radio-Linked Interferometer Network (MERLIN) at 5-GHz with 50 mas resolution, as part of a MERLIN Key-Project. Even though the time delays between the fold and cusp images are small (<~1 day) compared to the time-scale of intrinsic source variability, all six lens systems show evidence that suggests the presence of extrinsic variability. In particular, the cusp images of B2045+265 -- regarded as the strongest case of the violation of the cusp relation (i.e. the sum of the magnifications of the three cusp images add to zero) -- show extrinsic variations in their flux-ratios up to ~40 percent peak-to-peak on time scales of several months. Its low Galactic latitude of b=-10 degree and a line-of-sight toward the Cygnus superbubble region suggest that Galactic scintillation is the most likely cause. The cusp images of B1422+231 at b=+69 degree do not show strong extrinsic variability. Galactic scintillation can therefore cause significant scatter in the cusp and fold relations of some radio lens systems (up to 10 percent rms), even though these relations remain violated when averaged over a <~1 year time baseline.

L. V. E. Koopmans; A. Biggs; R. D. Blandford; I. W. A. Browne; N. J. Jackson; S. Mao; P. N. Wilkinson; A. G. de Bruyn; J. Wambsganss

2003-02-11T23:59:59.000Z

219

Solid-State 17O NMR Study of Benzoic Acid Adsorption On Metal Oxide Surfaces  

Science Conference Proceedings (OSTI)

Solid-state 17O NMR spectra of 17O-labeled benzoic and anisic acids are reported and benzoic acid is used to probe the surface of metal oxides. Complexes formed when benzoic acid is dry-mixed with mesoporous silica, and nonporous titania and alumina are characterized. Chemical reactions with silica are not observed. The nature of benzoic acid on silica is a function of the water content of the oxide. The acid disperses in the pores of the silica if the silica is in equilibrium with ambient laboratory humidity. The acid displays high mobility as evidenced by a liquid-like, Lorentzian resonance. Excess benzoic acid remains as the crystalline hydrogen-bonded dimer. Benzoic acid reacts with titania and alumina surfaces in equilibrium with laboratory air to form the corresponding titanium and aluminum benzoates. In both materials the oxygen of the 17O-labeled acid is bound to the metal, showing the reaction proceeds by bond formation between oxygen deficient metal sites and the oxygen of the carboxylic acid. 27Al MAS NMR confirms this mechanism for the reaction on alumina. Dry mixing of benzoic acid with alumina rapidly quenches pentacoordinate aluminum sites, excellent evidence that these sites are confined to the surface of the alumina particles.

Hagaman, Edward {Ed} W [ORNL; Chen, Banghao [ORNL; Jiao, Jian [ORNL; Parsons, Williams [Oak Ridge National Laboratory (ORNL)

2012-01-01T23:59:59.000Z

220

Proton conductivity of CsH{sub 2}PO{sub 4}WPA composites at intermediate temperatures  

SciTech Connect

CsH{sub 2}PO{sub 4} and H{sub 3}PW{sub 12}O{sub 40}6H{sub 2}O (WPA6H{sub 2}O) were mechanically milled by using planetary ball mill to obtain xCsH{sub 2}PO{sub 4}--(1-x)WPA6H{sub 2}O(%mol) composites. Characterizations of the composites indicate that there were changes of structure of CsH{sub 2}PO{sub 4}WPA composite after mechanical milling. {sup 1}H MAS NMR measurements suggested a hydrogen bond was newly developed between CsH{sub 2}PO{sub 4} and WPA which correlated with conductivity of the composites. 95CsH{sub 2}PO{sub 4}5WPA shows the highest conductivity at 70-170 deg. C range of temperature. The mechanical milling succeed to increase the conductivity under non-humidified atmosphere and intermediate temperature.

Insani, Evan Kamaratul [Department of Material Science, Toyohashi University of Technology, Toyohashi, Aichi 441-8580 (Japan); Department of Engineering Physics, Institut Teknologi Bandung, Bandung, West Java 40132 (Indonesia); Nguyen, Van H.; Kawamura, Go; Hamagami, Jun-ichi; Sakai, Mototsugu; Matsuda, Atsunori [Department of Material Science, Toyohashi University of Technology, Toyohashi, Aichi 441-8580 (Japan); Yuliarto, Brian [Department of Engineering Physics, Institut Teknologi Bandung, Bandung, West Java 40132 (Indonesia)

2010-10-24T23:59:59.000Z

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221

{sup 45}Sc Solid State NMR studies of the silicides ScTSi (T=Co, Ni, Cu, Ru, Rh, Pd, Ir, Pt)  

SciTech Connect

The silicides ScTSi (T=Fe, Co, Ni, Cu, Ru, Rh, Pd, Ir, Pt) were synthesized by arc-melting and characterized by X-ray powder diffraction. The structures of ScCoSi, ScRuSi, ScPdSi, and ScIrSi were refined from single crystal diffractometer data. These silicides crystallize with the TiNiSi type, space group Pnma. No systematic influences of the {sup 45}Sc isotropic magnetic shift and nuclear electric quadrupolar coupling parameters on various structural distortion parameters calculated from the crystal structure data can be detected. {sup 45}Sc MAS-NMR data suggest systematic trends in the local electronic structure probed by the scandium atoms: both the electric field gradients and the isotropic magnetic shifts relative to a 0.2 M aqueous Sc(NO{sub 3}){sub 3} solution decrease with increasing valence electron concentration and within each T group the isotropic magnetic shift decreases monotonically with increasing atomic number. The {sup 45}Sc nuclear electric quadrupolar coupling constants are generally well reproduced by quantum mechanical electric field gradient calculations using the WIEN2k code. Highlights: Black-Right-Pointing-Pointer Arc-melting synthesis of silicides ScTSi. Black-Right-Pointing-Pointer Single crystal X-ray data of ScCoSi, ScRuSi, ScPdSi, and ScIrSi. Black-Right-Pointing-Pointer {sup 45}Sc solid state NMR of silicides ScTSi.

Harmening, Thomas [Institut fuer Anorganische und Analytische Chemie and NRW Graduate School of Chemistry, Universitaet Muenster, Corrensstrasse 30, D-48149 Muenster (Germany); Eckert, Hellmut, E-mail: eckerth@uni-muenster.de [Institut fuer Physikalische Chemie, Universitaet Muenster, Corrensstrasse 30, D-48149 Muenster (Germany); Fehse, Constanze M. [Institut fuer Physikalische Chemie, Universitaet Muenster, Corrensstrasse 30, D-48149 Muenster (Germany); Sebastian, C. Peter, E-mail: sebastiancp@jncasr.ac.in [New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore 560064 (India); Poettgen, Rainer, E-mail: pottgen@uni-muenster.de [Institut fuer Anorganische und Analytische Chemie and NRW Graduate School of Chemistry, Universitaet Muenster, Corrensstrasse 30, D-48149 Muenster (Germany)

2011-12-15T23:59:59.000Z

222

A NEW LOOK AT THE OLD STAR CLUSTER NGC 6791  

SciTech Connect

We present comprehensive cluster membership and g'r' photometry of the prototypical old, metal-rich Galactic star cluster NGC 6791. The proper-motion catalog contains 58,901 objects down to g'{approx} 24, limited to a circular area of radius 30'. The highest precision of the proper motions is 0.08 mas yr{sup -1}. Our proper motions confirm cluster membership of all main and also some rare constituents of NGC 6791. The total number of probable cluster members down to g' = 22 (M{sub V} {approx} +8) is {approx}4800, corresponding to M{sub tot} {approx} 5000 M{sub sun}. New findings include an extended horizontal branch in this cluster. The angular radius of NGC 6791 is at least 15' (the effective radius is R{sub h} {approx_equal} 4.'4 while the tidal radius is r{sub t} {approx_equal} 23'). The luminosity function of the cluster peaks at M{sub g}{sup '}{approx}+4.5 and then steadily declines toward fainter magnitudes. Our data provide evidence that differential reddening may not be ignored in NGC 6791.

Platais, I. [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States); Cudworth, K. M. [Yerkes Observatory, University of Chicago, Williams Bay, WI 53191 (United States); Kozhurina-Platais, V. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); McLaughlin, D. E. [Astrophysics Group, Lennard-Jones Laboratories, Keele University, Keele, Staffordshire ST5 5BG (United Kingdom); Meibom, S. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Veillet, C., E-mail: imants@pha.jhu.edu [Canada-France-Hawaii Telescope Corporation, Kamuela, HI 96743 (United States)

2011-05-20T23:59:59.000Z

223

High resolution stationary digital breast tomosynthesis using distributed carbon nanotube x-ray source array  

Science Conference Proceedings (OSTI)

Purpose: The purpose of this study is to investigate the feasibility of increasing the system spatial resolution and scanning speed of Hologic Selenia Dimensions digital breast tomosynthesis (DBT) scanner by replacing the rotating mammography x-ray tube with a specially designed carbon nanotube (CNT) x-ray source array, which generates all the projection images needed for tomosynthesis reconstruction by electronically activating individual x-ray sources without any mechanical motion. The stationary digital breast tomosynthesis (s-DBT) design aims to (i) increase the system spatial resolution by eliminating image blurring due to x-ray tube motion and (ii) reduce the scanning time. Low spatial resolution and long scanning time are the two main technical limitations of current DBT technology. Methods: A CNT x-ray source array was designed and evaluated against a set of targeted system performance parameters. Simulations were performed to determine the maximum anode heat load at the desired focal spot size and to design the electron focusing optics. Field emission current from CNT cathode was measured for an extended period of time to determine the stable life time of CNT cathode for an expected clinical operation scenario. The source array was manufactured, tested, and integrated with a Selenia scanner. An electronic control unit was developed to interface the source array with the detection system and to scan and regulate x-ray beams. The performance of the s-DBT system was evaluated using physical phantoms. Results: The spatially distributed CNT x-ray source array comprised 31 individually addressable x-ray sources covering a 30 angular span with 1 pitch and an isotropic focal spot size of 0.6 mm at full width at half-maximum. Stable operation at 28 kV(peak) anode voltage and 38 mA tube current was demonstrated with extended lifetime and good source-to-source consistency. For the standard imaging protocol of 15 views over 14, 100 mAs dose, and 2 x 2 detector binning, the projection resolution along the scanning direction increased from 4.0 cycles/mm [at 10% modulation-transfer-function (MTF)] in DBT to 5.1 cycles/mm in s-DBT at magnification factor of 1.08. The improvement is more pronounced for faster scanning speeds, wider angular coverage, and smaller detector pixel sizes. The scanning speed depends on the detector, the number of views, and the imaging dose. With 240 ms detector readout time, the s-DBT system scanning time is 6.3 s for a 15-view, 100 mAs scan regardless of the angular coverage. The scanning speed can be reduced to less than 4 s when detectors become faster. Initial phantom studies showed good quality reconstructed images. Conclusions: A prototype s-DBT scanner has been developed and evaluated by retrofitting the Selenia rotating gantry DBT scanner with a spatially distributed CNT x-ray source array. Preliminary results show that it improves system spatial resolution substantially by eliminating image blur due to x-ray focal spot motion. The scanner speed of s-DBT system is independent of angular coverage and can be increased with faster detector without image degration. The accelerated lifetime measurement demonstrated the long term stability of CNT x-ray source array with typical clinical operation lifetime over 3 years.

Qian Xin; Tucker, Andrew; Gidcumb, Emily; Shan Jing; Yang Guang; Calderon-Colon, Xiomara; Sultana, Shabana; Lu Jianping; Zhou, Otto; Spronk, Derrek; Sprenger, Frank; Zhang Yiheng; Kennedy, Don; Farbizio, Tom; Jing Zhenxue [Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 (United States); Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 (United States); Curriculum in Applied Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 (United States); Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 (United States); Curriculum in Applied Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 (United States); Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 (United States) and Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 (United States); Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 (United States) Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 (United States) and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 (United States); XinRay Systems, Inc., Research Triangle Park, North Carolina 27709 (United States); Hologic, Inc., Bedford, Massachusetts 01730 (United States)

2012-04-15T23:59:59.000Z

224

New hypodiphosphates of the alkali metals: Synthesis, crystal structure and vibrational spectra of the hypodiphosphates(IV) M{sub 2}[(H{sub 2}P{sub 2}O{sub 6})(H{sub 4}P{sub 2}O{sub 6})] (M=Rb and Cs)  

Science Conference Proceedings (OSTI)

The new hypodiphosphates(IV) Rb{sub 2}[(H{sub 2}P{sub 2}O{sub 6})(H{sub 4}P{sub 2}O{sub 6})] (1) and Cs{sub 2}[(H{sub 2}P{sub 2}O{sub 6})(H{sub 4}P{sub 2}O{sub 6})] (2) were synthesized by soft chemistry reactions from aqueous solutions of hypophosphoric acid and the corresponding heavy alkali-metal carbonates. Their crystal structures were determined by single crystal X-ray diffraction. Both compounds crystallize isotypic in the triclinic space group P-1 with one formula unit in the unit cell. The structures are built up by discrete (H{sub 2}P{sub 2}O{sub 6}){sup 2-} and (H{sub 4}P{sub 2}O{sub 6}) units in staggered conformation for the P{sub 2}O{sub 6} skeleton and the corresponding alkali-metal cations. In the (H{sub 2}P{sub 2}O{sub 6}){sup 2-} ion the hydrogen atoms are in a 'trans-trans' conformation. O{center_dot}H-O hydrogen bonds between the (H{sub 2}P{sub 2}O{sub 6}){sup 2-} and (H{sub 4}P{sub 2}O{sub 6}) groups consolidate the structures into a three-dimensional network. The FT-Raman and {sup 31}P and {sup 1}H and MAS NMR spectra of the title compounds have been recorded and interpreted, especially with respect to their assignment to the (H{sub 2}P{sub 2}O{sub 6}){sup 2-} and (H{sub 4}P{sub 2}O{sub 6}) groups. Thermogravimetric data of 2 have been interpreted in terms of a thermal decomposition model. - Graphical Abstract: The layered compounds Rb{sub 2}[(H{sub 2}P{sub 2}O{sub 6})(H{sub 4}P{sub 2}O{sub 6})] and Cs{sub 2}[(H{sub 2}P{sub 2}O{sub 6})(H{sub 4}P{sub 2}O{sub 6})] have been synthesized and investigated. Both crystallize isotypic. The structures are built up by discrete (H{sub 2}P{sub 2}O{sub 6}){sup 2-} and (H{sub 4}P{sub 2}O{sub 6}) units and the corresponding alkali-metal cations. Highlights: Black-Right-Pointing-Pointer Synthesis and single-crystal structure of new alkali hypodiphosphates. Black-Right-Pointing-Pointer Structures are characterized by [(H{sub 2}P{sub 2}O{sub 6})(H{sub 4}P{sub 2}O{sub 6})]{sup 2-} units and M{sup +} cations. Black-Right-Pointing-Pointer (H{sub 2}P{sub 2}O{sub 6}){sup 2-} and (H{sub 4}P{sub 2}O{sub 6}) units are linked by short hydrogen bonds. Black-Right-Pointing-Pointer Both compounds are characterized by {sup 31}P MAS-NMR spectra.

Wu, Peng [Institut fuer Anorganische und Analytische Chemie der TU Clausthal, Paul-Ernst-Strasse 4, D-38678 Clausthal-Zellerfeld (Germany)] [Institut fuer Anorganische und Analytische Chemie der TU Clausthal, Paul-Ernst-Strasse 4, D-38678 Clausthal-Zellerfeld (Germany); Wiegand, Thomas; Eckert, Hellmut [Institut fuer Physikalische Chemie and Graduate School of Chemistry, Westfaelische Wilhelms-Universitaet Muenster, Corrensstr. 28/30, D-48149 Muenster (Germany)] [Institut fuer Physikalische Chemie and Graduate School of Chemistry, Westfaelische Wilhelms-Universitaet Muenster, Corrensstr. 28/30, D-48149 Muenster (Germany); Gjikaj, Mimoza, E-mail: mimoza.gjikaj@tu-clausthal.de [Institut fuer Anorganische und Analytische Chemie der TU Clausthal, Paul-Ernst-Strasse 4, D-38678 Clausthal-Zellerfeld (Germany)] [Institut fuer Anorganische und Analytische Chemie der TU Clausthal, Paul-Ernst-Strasse 4, D-38678 Clausthal-Zellerfeld (Germany)

2012-10-15T23:59:59.000Z

225

Mercury's spin-orbit model and signature of its dynamical parameters  

E-Print Network (OSTI)

The 3:2 spin-orbit resonance between the rotational and orbital motions of Mercury results from a functional dependance on a tidal friction adding to a non-zero eccentricity with a permanent asymmetry in the equatorial plane of the planet. The upcoming space missions, MESSENGER and BepiColombo with onboard instrumentation capable of measuring the Mercury's rotational parameters, stimulate the objective to attempt to an accurate theory of the planet's rotation. We have used our BJV relativistic model of solar system integration including the spin-orbit motion of the Moon. This model had been previously built in accordance with the requirements of the Lunar Laser Ranging observational accuracy. We extended this model to the spin-orbit couplings of the terrestrial planets including Mercury; the updated model is called SONYR (acronym of Spin-Orbit N-BodY Relativistic model). An accurate rotation of Mercury has been then obtained. Moreover, the conception of the SONYR model is suitable for analyzing the different families of hermean rotational librations. We accurately identify the non-linear relations between the rotation of Mercury and its dynamical figure (\\cmr2, $C_{20}$, and $C_{22}$). Notably, for a variation of 1% on the \\cmr2 value, signatures in the $\\phi$ hermean libration in longitude as well as in the $\\eta$ obliquity of the planet are respectively 0.45 arcseconds (as) and 2.4 milliarcseconds (mas). These determinations provide new constraints on the internal structure of Mercury to be discussed with the expected accuracy forecasted in the BepiColombo mission (respectively 3.2 and 3.7 as according to Milani et al 2001).

Nicolas Rambaux; Eric Bois

2003-07-17T23:59:59.000Z

226

PERIODIC STRUCTURE IN THE MEGAPARSEC-SCALE JET OF PKS 0637-752  

SciTech Connect

We present 18 GHz Australia Telescope Compact Array imaging of the megaparsec-scale quasar jet PKS 0637-752 with angular resolution {approx}0.''58. We draw attention to a spectacular train of quasi-periodic knots along the inner 11'' of the jet, with average separation {approx}1.1 arcsec (7.6 kpc projected). We consider two classes of model to explain the periodic knots: those that involve a static pattern through which the jet plasma travels (e.g., stationary shocks) and those that involve modulation of the jet engine. Interpreting the knots as re-confinement shocks implies the jet kinetic power Q{sub jet} {approx} 10{sup 46} erg s{sup -1}, but the constant knot separation along the jet is not expected in a realistic external density profile. For models involving modulation of the jet engine, we find that the required modulation period is 2 Multiplication-Sign 10{sup 3} yr < {tau} < 3 Multiplication-Sign 10{sup 5} yr. The lower end of this range is applicable if the jet remains highly relativistic on kiloparsec scales, as implied by the IC/CMB model of jet X-ray emission. We suggest that the periodic jet structure in PKS 0637-752 may be analogous to the quasi-periodic jet modulation seen in the microquasar GRS 1915+105, believed to result from limit cycle behavior in an unstable accretion disk. If variations in the accretion rate are driven by a binary black hole, the predicted orbital radius is 0.7 pc {approx}< a {approx}< 30 pc, which corresponds to a maximum angular separation of {approx}0.1-5 mas.

Godfrey, L. E. H.; Ekers, R. [International Centre for Radio Astronomy Research, Curtin University, GPO Box U1987, Perth, WA 6102 (Australia); Lovell, J. E. J. [CSIRO Astronomy and Space Science, Australia Telescope National Facility, P.O. Box 76, Epping, NSW 2121 (Australia); Burke-Spolaor, S. [NASA Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Bicknell, G. V.; Jauncey, D. L. [Research School of Astronomy and Astrophysics, Australian National University, Cotter Road, Weston, ACT 2611 (Australia); Birkinshaw, M.; Worrall, D. M.; Schwartz, D. A. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Marshall, H. L. [Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Gelbord, J. [Department of Physics, Durham University, South Road, Durham, DH1 3LE (United Kingdom); Perlman, E. S. [Physics and Space Sciences Department, Florida Institute of Technology, 150 West University Boulevard, Melbourne, FL 32901 (United States); Georganopoulos, M., E-mail: L.Godfrey@curtin.edu.au [Department of Physics, Joint Center for Astrophysics, University of Maryland-Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250 (United States)

2012-10-20T23:59:59.000Z

227

Cyclization Phenomena in the Sol-Gel Polymerization of a,w-Bis(triethoxysilyl)alkanes and Incorporation of the Cyclic Structures into Network Silsesquioxane Polymers  

Science Conference Proceedings (OSTI)

Intramolecular cyclizations during acid-catalyzed, sol-gel polymerizations of ct,co- bis(tietioxysilyl)aWmes substintidly lengtien gelties formonomers witietiylene- (l), propylene- (2), and butylene-(3)-bridging groups. These cyclizations reactions were found, using mass spectrometry and %i NMR spectroscopy, to lead preferentially to monomeric and dimeric products based on six and seven membered disilsesquioxane rings. 1,2- Bis(triethoxysilyl)ethane (1) reacts under acidic conditions to give a bicyclic drier (5) that is composed of two annelated seven membered rings. Under the same conditions, 1,3- bis(triethoxysilyl)propane (2), 1,4-bis(triethoxysilyl)butane (3), and z-1,4- bis(triethoxysilyl)but-2-ene (10) undergo an intramolecular condensation reaction to give the six membemd and seven membered cyclic disilsesquioxanes 6, 7, and 11. Subsequently, these cyclic monomers slowly react to form the tricyclic dirners 8,9 and 12. With NaOH as polymerization catalyst these cyclic silsesquioxanes readily ~aeted to afford gels that were shown by CP MAS z%i NMR and infr=d spectroscopes to retain some cyclic structures. Comparison of the porosity and microstructwe of xerogels prepared from the cyclic monomers 6 and 7 with gels prepared directly from their acyclic precursors 2 and 3, indicate that the final pore structure of the xerogels is markedly dependent on the nature of the precursor. In addition, despite the fact that the monomeric cyclic disilsesquioxane species can not be isolated from 1-3 under basic conditions due to their rapid rate of gelation, spectroscopic techniques also detected the presence of the cyclic structures in the resulting polymeric gels.

Alam, T.M.; Carpenter, J.P.; Dorhout, P.K.; Greaves, J.; Loy, D.A.; Shaltout, R.; Shea, K.J.; Small, J.H.

1999-01-04T23:59:59.000Z

228

EARLY SCIENCE WITH THE KOREAN VLBI NETWORK: THE QCAL-1 43 GHz CALIBRATOR SURVEY  

SciTech Connect

This paper presents the catalog of correlated flux densities in three ranges of baseline projection lengths of 637 sources from a 43 GHz (Q band) survey observed with the Korean VLBI Network. Of them, 14 objects used as calibrators were previously observed, but 623 sources have not been observed before in the Q band with very long baseline interferometry (VLBI). The goal of this work in the early science phase of the new VLBI array is twofold: to evaluate the performance of the new instrument that operates in a frequency range of 22-129 GHz and to build a list of objects that can be used as targets and as calibrators. We have observed the list of 799 target sources with declinations down to -40 Degree-Sign . Among them, 724 were observed before with VLBI at 22 GHz and had correlated flux densities greater than 200 mJy. The overall detection rate is 78%. The detection limit, defined as the minimum flux density for a source to be detected with 90% probability in a single observation, was in the range of 115-180 mJy depending on declination. However, some sources as weak as 70 mJy have been detected. Of 623 detected sources, 33 objects are detected for the first time in VLBI mode. We determined their coordinates with a median formal uncertainty of 20 mas. The results of this work set the basis for future efforts to build the complete flux-limited sample of extragalactic sources at frequencies of 22 GHz and higher at 3/4 of the celestial sphere.

Petrov, Leonid [Astrogeo Center, Falls Church, VA 22043 (United States); Lee, Sang-Sung; Kim, Jongsoo; Jung, Taehyun; Oh, Junghwan; Sohn, Bong Won; Byun, Do-Young; Chung, Moon-Hee; Je, Do-Heung; Wi, Seog-Oh; Song, Min-Gyu; Kang, Jiman; Han, Seog-Tae; Lee, Jung-Won; Kim, Bong Gyu; Chung, Hyunsoo; Kim, Hyun-Goo, E-mail: sslee@kasi.re.kr [Korean VLBI Network, Korea Astronomy and Space Science Institute, 776, Daedeokdae-ro, Yuseong-gu, Daejeon 305-348 (Korea, Republic of)

2012-11-01T23:59:59.000Z

229

DISENTANGLING CONFUSED STARS AT THE GALACTIC CENTER WITH LONG-BASELINE INFRARED INTERFEROMETRY  

SciTech Connect

We present simulations of Keck Interferometer ASTRA and VLTI GRAVITY observations of mock star fields in orbit within {approx}50 mas of Sgr A*. Dual-field phase referencing techniques, as implemented on ASTRA and planned for GRAVITY, will provide the sensitivity to observe Sgr A* with long-baseline infrared interferometers. Our results show an improvement in the confusion noise limit over current astrometric surveys, opening a window to study stellar sources in the region. Since the Keck Interferometer has only a single baseline, the improvement in the confusion limit depends on source position angles. The GRAVITY instrument will yield a more compact and symmetric point-spread function, providing an improvement in confusion noise which will not depend as strongly on position angle. Our Keck results show the ability to characterize the star field as containing zero, few, or many bright stellar sources. We are also able to detect and track a source down to m{sub K} {approx} 18 through the least confused regions of our field of view at a precision of {approx}200 {mu}as along the baseline direction. This level of precision improves with source brightness. Our GRAVITY results show the potential to detect and track multiple sources in the field. GRAVITY will perform {approx}10 {mu}as astrometry on an m{sub K} = 16.3 source and {approx}200 {mu}as astrometry on an m{sub K} = 18.8 source in 6 hr of monitoring a crowded field. Monitoring the orbits of several stars will provide the ability to distinguish between multiple post-Newtonian orbital effects, including those due to an extended mass distribution around Sgr A* and to low-order general relativistic effects. ASTRA and GRAVITY both have the potential to detect and monitor sources very close to Sgr A*. Early characterizations of the field by ASTRA, including the possibility of a precise source detection, could provide valuable information for future GRAVITY implementation and observation.

Stone, Jordan M.; Eisner, J. A. [Steward Observatory, University of Arizona, 933 N. Cherry Ave, Tucson, AZ 85721-0065 (United States); Monnier, J. D. [Astronomy Department, University of Michigan, 941 Dennison Bldg, Ann Arbor, MI 48109-1090 (United States); Woillez, J.; Wizinowich, P. [W. M. Keck Observatory, 65-1120 Mamalahoa Highway, Kamuela, HI 96743 (United States); Pott, J.-U. [Max-Planck-Institut fuer Astronomie, Koenigstuhl 1, D-69117 Heidelberg (Germany); Ghez, A. M., E-mail: jstone@email.arizona.edu, E-mail: jeisner@email.arizona.edu [Department of Physics and Astronomy, UCLA, Los Angeles, CA 90095-1547 (United States)

2012-08-01T23:59:59.000Z

230

Drug delivery from hydrophobic-modified mesoporous silicas: Control via modification level and site-selective modification  

SciTech Connect

Dimethylsilyl (DMS) modified mesoporous silicas were successfully prepared via co-condensation and post-grafting modification methods. The post-grafting modification was carried out by the reaction of the as-synthesized MCM-41 material (before CTAB removal) with diethoxydimethylsinale (DEDMS). N{sub 2} adsorption-desorption and {sup 29}Si MAS NMR characterization demonstrated that different amount of DMS groups were successfully incorporated into the co-condensation modified samples, and the functional DMS groups were placed selectively on the pore openings and external pore surfaces in the post-grafting modified samples. Subsequently, the controlled drug delivery properties from the resulting DMS-modified mesoporous silicas were investigated in detail. The drug adsorption experiments showed that the adsorption capacities were mainly depended on the content of silanol group (CSG) in the corresponding carriers. The in vitro tests exhibited that the incorporation of DMS groups greatly retarded the ibuprofen release rate. Moreover, the ibuprofen release profiles could be well modulated by varying DMS modification levels and site-selective distribution of functional groups in mesoporous carriers. - The distribution of DMS groups on the pore surfaces of the mesostructures strongly affects the drug release rate. The P-M41-1 and the P-M41-2 possess the close DMS modification levels as the C-M41-10, but the ibuprofen release rates from the P-M41-1 and P-M41-2 are much slower than that from the C-M41-10.

Tang Qunli, E-mail: tangqunli@hnu.c [College of Materials Science and Engineering, and Center for High-Resolution Electron Microscopy, Hunan University, Changsha 410082 (China); State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001 (China); Chen Yuxi; Chen Jianghua; Li Jin [College of Materials Science and Engineering, and Center for High-Resolution Electron Microscopy, Hunan University, Changsha 410082 (China); Xu Yao; Wu Dong; Sun Yuhan [State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001 (China)

2010-01-15T23:59:59.000Z

231

Molecular tools for marker-assisted breeding of buffelgrass  

E-Print Network (OSTI)

The increasing availability of molecular tools is facilitating marker-assisted selection (MAS) in plant improvement programs. The objectives of this research were to: 1) populate the framework buffelgrass genome map with additional molecular markers, 2) develop polymerase chain reaction (PCR)-based markers from selected, informative restriction fragment length polymorphism (RFLP) markers on the buffelgrass genome map, and 3) increase marker resolution near the locus conferring apomixis (PApo1). Buffelgrass [Pennisetum ciliare (L.) Link syn. Cenchrus ciliaris L.] (2n=4x=36), a highly polymorphic, apomictic, perennial forage grass, is well-suited for genetic linkage analyses. One hundred and seventy one probes from an apomictic, spikelet-specific, complementary deoxyribonucleic acid (cDNA) library and 70 expressed sequence tag simple sequence repeats (EST-SSRs) from apomictic pistil cDNAs were evaluated and added to the framework buffelgrass genome map. The improved linkage map contains 851 markers from 11 grass species and covers approximately 80-85% of the buffelgrass genome. Two RFLPs from the buffelgrass genome map were converted to PCR-based markers for both the identification of hybrids and quantification of sexual versus apomictic reproduction. A gel-free, high-throughput technique was developed to analyze these markers directly in 96-well plates. Five additional markers were placed onto the buffelgrass linkage group with the PApo1 apomixis locus through comparative mapping of candidate orthologs from the sorghum genome map and bulked-segregant analysis of amplified-fragment-lengthpolymorphisms (BSA-AFLP). Increasing the mapping population size did not increase map resolution in the PApo1 region. Association mapping revealed that the recombination suppression near PApo1 is moderate and would complicate comparative map-based cloning efforts of the orthologous region in sorghum.

Jessup, Russell William

2005-08-01T23:59:59.000Z

232

An investigation of the role of water on retrograde/condensation reactions and enhanced liquefaction yields  

SciTech Connect

Changes in coal structure that may occur during coal drying will be measured in order to determine the effects of coal drying on its reactivity toward liquefaction. Different methods for coal drying will be investigated to determine if drying can be accomplished without destroying coal reactivity toward liquefaction, thereby making coal drying a relatively economical and efficient method for coal pretreatment. Coal drying methods will include conventional thermal drying, microwave drying and chemical drying at low temperature. State-of-the-art solid-state nuclear magnetic resonance (NMR) techniques using combined rotation and multiple pulse spectroscopy (CRAMPS) and cross polarization with magic-angle spinning (CP/MAS) will be employed: (1) to measures changes in coal structure brought about by the different methods of drying and by low temperature oxidation, and (2) to obtain direct measurements of changes in the aromatic hydrogen-to-carbon ratio of the solid/semisolid material formed or remaining during pretreatment and the initial stages of liquefaction. The objectives for this quarter were to begin coal drying experiments using thermal, microwave, and chemical methods, and to begin coal liquefaction experiments on the dried coals. Three additional coal samples have been acquired. These are a Black Thunder Mine coal acquired from Arco Coal Co, and a Texas subC and Illinois No. 6 hvC acquired from the DOE coal sample bank at Penn State. The samples are listed as DECS-1 and DECS-2, respectively in the PSU sample bank. The ultimate and proximate analyses for all the samples are given in Table 1. Work on each of the subtasks is described in separate paragraphs.

Miknis, F.P.

1993-04-01T23:59:59.000Z

233

An extremely wide and very low-mass pair with common proper motion. Is it representative of a nearby halo stream?  

E-Print Network (OSTI)

(abridged) We describe the discovery of an extremely wide pair of low-mass stars with a common large proper motion and discuss their possible membership in a Galactic halo stream crossing the Solar neighbourhood. (...) The late-type (M7) dwarf SSSPM J2003$-$4433 and the ultracool subdwarf SSSPM J1930$-$4311 (sdM7) sharing the same very large proper motion of about 860 mas/yr were found in the same sky region with an angular separation of about 6\\degr. From the comparison with other high proper motion catalogues we have estimated the probability of a chance alignment of the two new large proper motions to be less than 0.3%. From the individually estimated spectroscopic distances of about $38^{+10}_{-7}$ pc and $72^{+21}_{-16}$ pc, respectively for the M7 dwarf and the sdM7 subdwarf, and in view of the accurate agreement in their large proper motions we assume a common distance of about 50 pc and a projected physical separation of about 5 pc. The mean heliocentric space velocity of the pair $(U,V,W)=(-232, -170, +74)$ km/s, based on the correctness of the preliminary radial velocity measurement for only one of the components and on the assumption of a common distance and velocity vector, is typical of the Galactic halo population. The large separation and the different metallicities of dwarfs and subdwarfs make a common formation scenario as a wide binary (later disrupted) improbable, although there remains some uncertainty in the spectroscopic classification scheme of ultracool dwarfs/subdwarfs so that a dissolved binary origin cannot be fully ruled out yet. It seems more likely that this wide pair is part of an old halo stream. (...)

R. -D. Scholz; N. V. Kharchenko; N. Lodieu; M. J. McCaughrean

2008-07-03T23:59:59.000Z

234

THE ORIGIN OF THE VIRGO STELLAR SUBSTRUCTURE  

Science Conference Proceedings (OSTI)

We present three-dimensional space velocities of stars selected to be consistent with membership in the Virgo stellar substructure. Candidates were selected from SA 103, a single 40' Multiplication-Sign 40' field from our proper-motion (PM) survey in Kapteyn's Selected Areas (SAs), based on the PMs, Sloan Digital Sky Survey (SDSS) photometry, and follow-up spectroscopy of 215 stars. The signature of the Virgo substructure is clear in the SDSS color-magnitude diagram (CMD) centered on SA 103, and 16 stars are identified that have high Galactocentric-frame radial velocities (V{sub GSR} > 50 km s{sup -1}) and lie near the CMD locus of Virgo. The implied distance to the Virgo substructure from the candidates is 14 {+-} 3 kpc. We derive mean kinematics from these 16 stars, finding a radial velocity V{sub GSR} = 153 {+-} 22 km s{sup -1} and proper motions ({mu}{sub {alpha}}cos {delta}, {mu}{sub {delta}}) = (- 5.24, -0.91) {+-} (0.43, 0.46) mas yr{sup -1}. From the mean kinematics of these members, we determine that the Virgo progenitor was on an eccentric (e {approx} 0.8) orbit that recently passed near the Galactic center (pericentric distance R{sub p} {approx} 6 kpc). This destructive orbit is consistent with the idea that the substructure(s) in Virgo originated in the tidal disruption of a Milky Way satellite. N-body simulations suggest that the entire cloud-like Virgo substructure (encompassing the 'Virgo Overdensity' and the 'Virgo Stellar Stream') is likely the tidal debris remnant from a recently disrupted massive ({approx}10{sup 9} M{sub Sun }) dwarf galaxy. The model also suggests that some other known stellar overdensities in the Milky Way halo (e.g., the Pisces Overdensity and debris near NGC 2419 and SEGUE 1) are explained by the disruption of the Virgo progenitor.

Carlin, Jeffrey L.; Yam, William; Willett, Benjamin A.; Newberg, Heidi J. [Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY 12180 (United States); Casetti-Dinescu, Dana I.; Girard, Terrence M. [Astronomy Department, Yale University, P.O. Box 208101, New Haven, CT 06520-8101 (United States); Majewski, Steven R., E-mail: carlij@rpi.edu [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904-4325 (United States)

2012-07-10T23:59:59.000Z

235

Physical Orbit for Lambda Virginis and a Test of Stellar Evolution Models  

E-Print Network (OSTI)

Lambda Virginis (LamVir) is a well-known double-lined spectroscopic Am binary with the interesting property that both stars are very similar in abundance but one is sharp-lined and the other is broad-lined. We present combined interferometric and spectroscopic studies of LamVir. The small scale of the LamVir orbit (~20 mas) is well resolved by the Infrared Optical Telescope Array (IOTA), allowing us to determine its elements as well as the physical properties of the components to high accuracy. The masses of the two stars are determined to be 1.897 Msun and 1.721 Msun, with 0.7% and 1.5% errors respectively, and the two stars are found to have the same temperature of 8280 +/- 200 K. The accurately determined properties of LamVir allow comparisons between observations and current stellar evolution models, and reasonable matches are found. The best-fit stellar model gives LamVir a subsolar metallicity of Z=0.0097, and an age of 935 Myr. The orbital and physical parameters of LamVir also allow us to study its tidal evolution time scales and status. Although currently atomic diffusion is considered to be the most plausible cause of the Am phenomenon, the issue is still being actively debated in the literature. With the present study of the properties and evolutionary status of LamVir, this system is an ideal candidate for further detailed abundance analyses that might shed more light on the source of the chemical anomalies in these A stars.

M. Zhao; J. D. Monnier; G. Torres; A. F. Boden; A. Claret; R. Millan-Gabet; E. Pedretti; J. -P. Berger; W. A. Traub; F. P. Schloerb; N. P. Carleton; P. Kern; M. G. Lacasse; F. Malbet; K. Perraut

2006-12-05T23:59:59.000Z

236

Sco X-1: The Evolution and Nature of the Twin Compact Radio Lobes  

E-Print Network (OSTI)

The radio components associated with the LMXB Sco X-1 have been monitored with extensive VLBI imaging at 1.7 and 5.0 GHz over four years, including a 56-hour continuous VLBI observation in 1999 June. We often detected one strong and one weak compact radio component, moving in opposite directions from the radio core. We suggest that the moving components are radio lobes generated by the disruption of energy flow in a twin-beam from the binary system. The average lifetime of a lobe-pair, the space motion of the lobes and the measured energy flow in the beam are discussed in arXiv:astro-ph/0104325. The lobe has a flux density that is variable over a time-scale of one hour, a measured minimum size of 1 mas (2.8 au), and is extended perpendicular to its motion. This short electron radiative lifetime may be caused by synchrotron losses if the lobe magnetic field is 300 G, or by adiabatic expansion of the electrons as soon as they are produced at the working surface. The lobes also show periods of slow expansion and a steepening radio spectrum, perhaps related to the characteristics of the beam energy flow. The radio morphology for Sco X-1 is more simple than for most other Galactic jet sources. The lobes of Sco X-1 are similar to hot-spots found in many extragalactic double sources. Scaling the phenomena observed in Sco X-1 to extragalactic sources implies hot-spot variability time-scales of 10^4 yr and hot-spot lifetimes of 10^5 yr. The recurrent formation of lobes in Sco X-1 probably does not occur for extragalactic radio sources.

E. B. Fomalont; B. J. Geldzahler; C. F. Bradshaw

2001-04-23T23:59:59.000Z

237

Inverse determination of the penalty parameter in penalized weighted least-squares algorithm for noise reduction of low-dose CBCT  

Science Conference Proceedings (OSTI)

Purpose: A statistical projection restoration algorithm based on the penalized weighted least-squares (PWLS) criterion can substantially improve the image quality of low-dose CBCT images. The performance of PWLS is largely dependent on the choice of the penalty parameter. Previously, the penalty parameter was chosen empirically by trial and error. In this work, the authors developed an inverse technique to calculate the penalty parameter in PWLS for noise suppression of low-dose CBCT in image guided radiotherapy (IGRT). Methods: In IGRT, a daily CBCT is acquired for the same patient during a treatment course. In this work, the authors acquired the CBCT with a high-mAs protocol for the first session and then a lower mAs protocol for the subsequent sessions. The high-mAs projections served as the goal (ideal) toward, which the low-mAs projections were to be smoothed by minimizing the PWLS objective function. The penalty parameter was determined through an inverse calculation of the derivative of the objective function incorporating both the high and low-mAs projections. Then the parameter obtained can be used for PWLS to smooth the noise in low-dose projections. CBCT projections for a CatPhan 600 and an anthropomorphic head phantom, as well as for a brain patient, were used to evaluate the performance of the proposed technique. Results: The penalty parameter in PWLS was obtained for each CBCT projection using the proposed strategy. The noise in the low-dose CBCT images reconstructed from the smoothed projections was greatly suppressed. Image quality in PWLS-processed low-dose CBCT was comparable to its corresponding high-dose CBCT. Conclusions: A technique was proposed to estimate the penalty parameter for PWLS algorithm. It provides an objective and efficient way to obtain the penalty parameter for image restoration algorithms that require predefined smoothing parameters.

Wang, Jing; Guan, Huaiqun; Solberg, Timothy [Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, Texas 75390 (United States); Department of Radiation oncology, Sylvester Comprehensive Cancer Center, University of Miami Medical School, Florida 33136 (United States); Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, Texas 75390 (United States)

2011-07-15T23:59:59.000Z

238

Efficacy of Lower-Body Shielding in Computed Tomography Fluoroscopy-Guided Interventions  

Science Conference Proceedings (OSTI)

Purpose: Computed tomography (CT) fluoroscopy-guided interventions pose relevant radiation exposure to the interventionalist. The goal of this study was to analyze the efficacy of lower-body shielding as a simple structural method for decreasing radiation dose to the interventionalist without limiting access to the patient. Material and Methods: All examinations were performed with a 128-slice dual source CT scanner (12 Multiplication-Sign 1.2-mm collimation; 120 kV; and 20, 40, 60, and 80 mAs) and an Alderson-Rando phantom. Scatter radiation was measured with an ionization chamber and a digital dosimeter at standardized positions and heights with and without a lower-body lead shield (0.5-mm lead equivalent; Kenex, Harlow, UK). Dose decreases were computed for the different points of measurement. Results: On average, lower-body shielding decreased scatter radiation by 38.2% within a 150-cm radius around the shielding. This decrease is most significant close to the gantry opening and at low heights of 50 and 100 cm above the floor with a maximum decrease of scatter radiation of 95.9% close to the scanner's isocentre. With increasing distance to the gantry opening, the effect decreased. There is almost no dose decrease effect at {>=}150 above the floor. Scatter radiation and its decrease were linearly correlated with the tube current-time product (r{sup 2} = 0.99), whereas percent scatter radiation decrease was independent of the tube current-time product. Conclusion: Lower-body shielding is an effective way to decrease radiation exposure to the interventionalist and should routinely be used in CT fluoroscopy-guided interventions.

Mahnken, Andreas H., E-mail: mahnken@rad.rwth-aachen.de [RWTH Aachen, Department of Diagnostic and Interventional Radiology (Germany); Sedlmair, Martin [Siemens, Healthcare Sector (Germany); Ritter, Christine [University of Copenhagen, Niels Bohr Institute (Denmark); Banckwitz, Rosemarie; Flohr, Thomas [Siemens, Healthcare Sector (Germany)

2012-12-15T23:59:59.000Z

239

A characterization and evaluation of coal liquefaction process streams. Quarterly technical progress report, July 1--September 30, 1995  

Science Conference Proceedings (OSTI)

The objectives of this project are to support the DOE direct coal liquefaction process development program and to improve the useful application of analytical chemistry to direct coal liquefaction process development. Independent analyses by well-established methods will be obtained of samples produced in direct coal liquefaction processes under evaluation by DOE. Additionally, analytical instruments and techniques which are currently underutilized for the purpose of examining coal-derived samples will be evaluated. The data obtained from this study will be used to help guide current process development and to develop an improved data base on coal and coal liquids properties. A sample bank will be established and maintained for use in this project and will be available for use by other researchers. The reactivity of the non-distillable resids toward hydrocracking at liquefaction conditions (i.e., resid reactivity) will be examined. From the literature and data experimentally obtained, a mathematical kinetic model of resid conversion will be constructed. It is anticipated that such a model will provide insights useful for improving process performance and thus the economics of direct coal liquefaction. Some of the contract activities for this quarter are: We completed many of the analyses on the 81 samples received from HTI bench-scale run CMSL-9, in which coal, coal/mixed plastics, and coal/high density polyethylene were fed; Liquid chromatographic separations of the 15 samples in the University of Delaware sample set were completed; and WRI completed CP/MAS {sup 13}C-NMR analyses on the Delaware sample set.

Robbins, G.A.; Brandes, S.D.; Winschel, R.A.; Burke, F.P.

1995-12-01T23:59:59.000Z

240

SUPPORT OF NEW COMPUTER HARDWARE AT LUCH'S MC&A SYSTEM: PROBLEMS AND A SOLUTION  

Science Conference Proceedings (OSTI)

Abstract Microsoft Windows NT 4.0 operating system is the only software product certified in Russia for using in MC&A systems. In the paper a solution for allowing the installation of this outdated operating system on new computers is discussed. The solution has been successfully tested and has been in use at Luch's network since March 2008. Furthermore, it is being recommended for other Russian enterprises for the same purpose. Introduction Typically, the software part of a nuclear material control and accounting (MC&A) system consists of an operating system (OS), database management systems (DBMS), accounting program itself and database of nuclear materials. Russian regulations require the operating system and database for MC&A be certified for information security, and the whole system must pass an accreditation. Historically, the only certified operating system for MC&A still continues to be Microsoft Windows NT 4.0 Server/Workstation. Attempts to certify newer versions of Windows failed. Luch, like most other Russian sites, uses Microsoft Windows NT 4.0 and SQL Server 6.5. Luch's specialists have developed an application (LuchMAS) for accounting purposes. Starting from about 2004, some problems appeared in Luch's accounting system. They were related to the complexity of installing Windows NT 4.0 on new computers. At first, it was possible to solve the problem choosing computer equipment that is compatible with Windows NT 4.0 or selecting certain operating system settings. Over time, the problem worsened and now it is almost impossible to install Windows NT 4.0 on new computers. The reason is the lack of hardware drivers in the outdated operating system. The problem was serious enough that it could have affected the long-term sustainability of Luch's MC&A system if adequate alternate measures were not developed.

Fedoseev, Victor; Shanin, Oleg

2009-07-14T23:59:59.000Z

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


241

Structural and thermal characterization of CaO-MgO-SiO2-P2O5-CaF2 glasses  

SciTech Connect

The paper presents the influence of varying CaO/MgO ratio on the structure and thermal properties of CaO-MgO-SiO2-P2O5-CaF2 glasses. A series of eight glass compositions in the glass forming region of diopside (CaMgSi2O6) - fluorapatite [Ca5(PO4)3F] - wollastonite (CaSiO3) ternary system have been designed and synthesized by varying diopside/wollastonite ratio in glasses. The as prepared melt-quenched glasses have been characterized for their structure by infrared spectroscopy (FTIR) and magic angle spinning (MAS)-nuclear magnetic resonance (NMR) spectroscopy. Silicon is predominantly present as Q2 (Si) species, while phosphorus tends to coordinate in orthophosphate environment in all the investigated glasses. The change in CaO/MgO ratio had an insignificant affect on the structure of glasses. The thermal sintering and crystallization parameters for the studied glasses have been obtained from differential thermal analysis (DTA) while crystalline phase fractions in the sintered glass-ceramics have been analyzed by X-ray diffraction adjoined with Rietveld refinement. Diopside, fluorapatite, wollastonite and pseudowollastonite have crystallized as the main crystalline phases in all the glass-ceramics with their content varying with respect to variation in CaO/MgO ratio in glasses. Scanning electron microscopy (SEM) has been used to shed light on the microstructure of glass-ceramics. The possible implications of structure and sintering behaviour of glasses on their bioactivity have been discussed.

Kansal, Ishu; Goel, Ashutosh; Tulyaganov, Dilshat U.; Rajagopal, Raghu R.; Ferreira, Jose M.

2012-08-01T23:59:59.000Z

242

Influence of strontium on structure, sintering and biodegradation behaviour of CaO-MgO-SrO-SiO2-P2O5-CaF2 glasses  

SciTech Connect

The present study investigates the influence of SrO on structure, apatite forming ability, physico-chemical degradation and sintering behaviour of melt-quenched bioactive glasses with composition: mol.% (36.07 – x) CaO – x SrO - 19.24 MgO – 5.61 P2O5 – 38.49 SiO2 – 0.59 CaF2, where x varies between 0 – 10. The detailed structural analysis of glasses has been made by infra red spectroscopy (FTIR) and magic angle spinning-nuclear magnetic resonance spectroscopy (MAS-NMR). Silicon was predominantly present as Q2 (Si) species while phosphorus was found in orthophosphate type environment in all the investigated glasses. The apatite forming ability of glasses was investigated by immersion of glass powders in simulated body fluid (SBF) for time durations varying between 1 h – 7 days. While increasing Sr2+/Ca2+ ratio in glasses did not affect the structure of glasses significantly, their apatite forming ability was decreased considerably. Further, physico-chemical degradation of glasses has been studied in accordance with ISO 10993-14 “Biological evaluation of medical devices – Part 14: Identification and quantification of degradation products from ceramics” in Tris HCl and citric acid buffer and the possible implications of ion release profile from glasses in different solutions has been discussed. The addition of strontium in glasses led to a 7-fold decrease in chemical degradation of glasses in Tris-HCl. The sintering of glass powders rendered glass-ceramics (GCs) with varying degree of crystallinity and good flexural strength (98-131 MPa) where the mechanical properties depend on the nature and amount of crystalline phases present in GCs.

Goel, Ashutosh; Rajagopal, Raghu R.; Ferreira, Jose M.

2011-11-01T23:59:59.000Z

243

Full differentiation and assignment of boron species in the electrolytes Li{sub 2}B{sub 6}O{sub 9}F{sub 2} and Li{sub 2}B{sub 3}O{sub 4}F{sub 3} by solid-state {sup 11}B NMR spectroscopy  

SciTech Connect

The syntheses of two new fluorooxoborates, Li{sub 2}B{sub 3}O{sub 4}F{sub 3} and Li{sub 2}B{sub 6}O{sub 9}F{sub 2}, which possess considerable ion conductivity at higher temperatures, have been reported recently. Here, we describe the characterisation of these compounds by solid-state {sup 11}B NMR spectroscopy. The complex central-transition MAS spectra, resulting from overlap of sub-spectra contributed by the individual boron species in the crystal structures, could be clearly separated by acquisition and analysis of 3QMAS spectra. By numerical fit of these sub-spectra, the isotropic chemical shift {delta}{sub iso}, the quadrupolar coupling constant {chi}, and the asymmetry {eta} were determined. Using known relations between boron coordination and chemical shift as well as quadrupolar coupling, the individual {sup 11}B NMR resonances have been ascribed to boron species in tetrahedral or trigonal environment. To remove remaining assignment ambiguities, the response of the {sup 11}B resonances to {sup 19}F decoupling was qualitatively analysed. Thus, by using the combined information conveyed by chemical shift, quadrupolar and dipolar interaction, a complete assignment of the complex {sup 11}B line shapes exhibited by the fluorooxoborates has been achieved. - Graphical abstract: Structure and solid-state {sup 11}B NMR spectrum of Li{sub 2}B{sub 3}O{sub 4}F{sub 3}. Highlights: Black-Right-Pointing-Pointer Characterisation of title compounds by solid-state {sup 11}B NMR spectroscopy. Black-Right-Pointing-Pointer Sub-spectra of boron species separated by evaluation of 3QMAS spectra. Black-Right-Pointing-Pointer Isotropic chemical shift and quadrupolar interaction parameters determined. Black-Right-Pointing-Pointer Full boron assignment based on NMR parameters and response to {sup 19}F decoupling.

Braeuniger, Thomas, E-mail: T.Braeuniger@fkf.mpg.de [Max Planck Institute for Solid State Research, Heisenbergstrasse 1, 70569 Stuttgart (Germany)] [Max Planck Institute for Solid State Research, Heisenbergstrasse 1, 70569 Stuttgart (Germany); Pilz, Thomas; Chandran, C. Vinod; Jansen, Martin [Max Planck Institute for Solid State Research, Heisenbergstrasse 1, 70569 Stuttgart (Germany)] [Max Planck Institute for Solid State Research, Heisenbergstrasse 1, 70569 Stuttgart (Germany)

2012-10-15T23:59:59.000Z

244

The Milky Way Tomography with SDSS: II. Stellar Metallicity  

E-Print Network (OSTI)

Using effective temperature and metallicity derived from SDSS spectra for ~60,000 F and G type main sequence stars (0.2mas/yr, for about 200 million F/G dwarf stars within a distance limit of ~100 kpc (g<23.5). [abridged

Zeljko Ivezic; Branimir Sesar; Mario Juric; Nicholas Bond; Julianne Dalcanton; Constance M. Rockosi; Brian Yanny; Heidi J. Newberg; Timothy C. Beers; Carlos Allende Prieto; Ron Wilhelm; Young Sun Lee; Thirupathi Sivarani; John E. Norris; Coryn A. L. Bailer-Jones; Paola Re Fiorentin; David Schlegel; Alan Uomoto; Robert H. Lupton; Gillian R. Knapp; James E. Gunn; Kevin R. Covey; J. Allyn Smith; Gajus Miknaitis; Mamoru Doi; Masayuki Tanaka; Masataka Fukugita; Steve Kent; Douglas Finkbeiner; Jeffrey A. Munn; Jeffrey R. Pier; Tom Quinn; Suzanne Hawley; Scott Anderson; Furea Kiuchi; Alex Chen; James Bushong; Harkirat Sohi; Daryl Haggard; Amy Kimball; John Barentine; Howard Brewington; Mike Harvanek; Scott Kleinman; Jurek Krzesinski; Dan Long; Atsuko Nitta; Stephanie Snedden; Brian Lee; Hugh Harris; Jonathan Brinkmann; Donald P. Schneider; Donald G. York

2008-04-24T23:59:59.000Z

245

A SEARCH FOR HIGH PROPER MOTION T DWARFS WITH Pan-STARRS1 + 2MASS + WISE  

Science Conference Proceedings (OSTI)

We have searched {approx}8200 deg{sup 2} for high proper motion ({approx}0.''5-2.''7 year{sup -1}) T dwarfs by combining first-epoch data from the Pan-STARRS1 (PS1) 3{pi} Survey, the Two Micron All Sky Survey (2MASS) All-Sky Point Source Catalog, and the WISE Preliminary Data Release. We identified two high proper motion objects with the very red (W1 - W2) colors characteristic of T dwarfs, one being the known T7.5 dwarf GJ 570D. Near-IR spectroscopy of the other object (PSO J043.5395+02.3995 {identical_to} WISEP J025409.45+022359.1) reveals a spectral type of T8, leading to a photometric distance of 7.2 {+-} 0.7 pc. The 2.''56 year{sup -1} proper motion of PSO J043.5+02 is the second highest among field T dwarfs, corresponding to a tangential velocity of 87 {+-} 8 km s{sup -1}. According to the Besancon galaxy model, this velocity indicates that its galactic membership is probably in the thin disk, with the thick disk an unlikely possibility. Such membership is in accord with the near-IR spectrum, which points to a surface gravity (age) and metallicity typical of the field population. We combine 2MASS, Sloan Digital Sky Survey, WISE, and PS1 astrometry to derive a preliminary parallax of 171 {+-} 45 mas (5.8{sup +2.0} {sub -1.2} pc), the first such measurement using PS1 data. The proximity and brightness of PSO J043.5+02 will facilitate future characterization of its atmosphere, variability, multiplicity, distance, and kinematics. The modest number of candidates from our search suggests that the immediate ({approx}10 pc) solar neighborhood does not contain a large reservoir of undiscovered T dwarfs earlier than about T8.

Liu, Michael C.; Deacon, Niall R.; Magnier, Eugene A.; Aller, Kimberly M.; Bowler, Brendan P.; Burgett, W. S.; Chambers, K. C.; Hodapp, K. W.; Kaiser, N.; Kudritzki, R.-P.; Morgan, J. S.; Tonry, J. L.; Wainscoat, R. J. [Institute for Astronomy, University of Hawaii, Honolulu, HI 96822 (United States); Dupuy, Trent J. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Redstone, Joshua [Facebook, Palo Alto, CA 94304 (United States); Goldman, Bertrand [Max Planck Institute for Astronomy, D-69117 Heidelberg (Germany); Price, P. A. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States)

2011-10-20T23:59:59.000Z

246

Class B0631+519: Last of the Class Lenses  

SciTech Connect

We report the discovery of the new gravitational lens system CLASS B0631+519. Imaging with the VLA, MERLIN and the VLBA reveals a doubly-imaged flat-spectrum radio core, a doubly-imaged steep-spectrum radio lobe and possible quadruply-imaged emission from a second lobe. The maximum separation between the lensed images is 1.16 arcsec. High resolution mapping with the VLBA at 5 GHz resolves the most magnified image of the radio core into a number of sub-components spread across approximately 20 mas. No emission from the lensing galaxy or an odd image is detected down to 0.31 mJy (5{sigma}) at 8.4 GHz. Optical and near-infrared imaging with the ACS and NICMOS cameras on the HST show that there are two galaxies along the line of sight to the lensed source, as previously discovered by optical spectroscopy. We find that the foreground galaxy at z=0.0896 is a small irregular, and that the other, at z=0.6196 is a massive elliptical which appears to contribute the majority of the lensing effect. The host galaxy of the lensed source is detected in the HST near-infrared imaging as a set of arcs, which form a nearly complete Einstein ring. Mass modeling using non-parametric techniques can reproduce the near-infrared observations and indicates that the small irregular galaxy has a (localized) effect on the flux density distribution in the Einstein ring at the 5-10% level.

York, Tom; Jackson, N.; Browne, I.W.A.; Koopmans, L.V.E.; McKean, J.P.; Norbury, M.A.; Biggs, A.D.; Blandford, R.D.; de Bruyn, A.G.; Fassnacht, C.D.; Myers, S.T.; Pearson, T.J.; Phillips, P.M.; Readhead, A.C.S.; Rusin, D.; Wilkinson, P.N.; /Jodrell Bank /Kapteyn Astron. Inst., Groningen /UC, Davis /JIVE, Dwingeloo /KIPAC, Menlo Park /NFRA, Dwingeloo /NRAO, Socorro /Caltech /Pennsylvania U.

2005-05-31T23:59:59.000Z

247

References  

E-Print Network (OSTI)

Los algoritmos evolutivos (AE) son técnicas de optimización basadas en los principios de evolución natural [7]. Aunque los AEs han sido utilizados en solucionar muchos problemas de optimización de manera exitosa, el rendimiento de ellos (medido en tiempo consumido y calidad de la solución producida) depende de la selección adecuada de los parámetros del AE: Operadores genéticos, probabilidades de aplicación de los mismos, tamaño de la población, esquema de selección, etc. Es mas, el proceso de jar tales parámetros es considerado un proceso que consume mucho tiempo [10]. Tomando en cuenta la importancia de este proceso, muchos trabajos de investigación han tratado de manejarlo de diversas maneras [4]. Algunos trabajos han tratado de determinar el valor apropiado de dichos parámetros mediante experimentación extensiva de los mismos en la solución de un conjunto de funciones previamente prede nido [3, 11], o mediante un análisis teórico [5, 1, 9]. Otro conjunto de trabajos, llamados Adaptación de Parámetros (AP), han tratado de eliminar el proceso de selección de parámetros mediante la adaptación de los mismos al tiempo que el algoritmo evolutivo esta siendo ejecutado [2, 8, 13, 9, 12, 6]. En este proyecto se plantea una solución al problema de jar los parámetros mediante técnicas de auto adaptación de parámetros (Meta-evolución). Con tal n, se pretende extender el Algoritmo Evolutivo de Auto Adaptación Híbrida (HAEA por sus siglas en ingles) propuesto por Gomez en [6], de tal manera que no solamente adapte las probabilidades de los operadores genéticos sino los siguientes parámetros: Tamaño de población, mecanismos de selección y operadores genéticos.

Definición Del Problema; A. E. Eiben; R. Hinterding

2007-01-01T23:59:59.000Z

248

Redshifted emission lines and radiative recombination continuum from the Wolf-Rayet binary theta Muscae: evidence for a triplet system?  

E-Print Network (OSTI)

We present XMM-Newton observations of the WC binary Theta Muscae (WR 48), the second brightest Wolf-Rayet binary in optical wavelengths. The system consists of a short-period (19.1375 days) WC5/WC6 + O6/O7V binary and possibly has an additional O supergiant companion (O9.5/B0Iab) which is optically identified at a separation of ~46 mas. Strong emission lines from highly ionized ions of C, O, Ne, Mg, Si, S, Ar, Ca and Fe are detected. The spectra are fitted by a multi-temperature thin-thermal plasma model with an interstellar absorption N_H = 2--3*10**21 cm**-2. Lack of nitrogen line indicates that the abundance of carbon is at least an order of magnitude larger than that of nitrogen. A Doppler shift of ~630 km/s is detected for the OVIII line, while similar shifts are obtained from the other lines. The reddening strongly suggests that the emission lines originated from the wind-wind shock zone, where the average velocity is ~600 km/s. The red-shift motion is inconsistent with a scenario in which the X-rays originate from the wind-wind collision zone in the short-period binary, and would be evidence supporting the widely separated O supergiant as a companion. This may make up the collision zone be lying behind the short-period binary. In addition to the emission lines, we also detected the RRC (radiative recombination continuum) structure from carbon around 0.49 keV. This implies the existence of additional cooler plasma.

Yasuharu Sugawara; Yohko Tsuboi; Yoshitomo Maeda

2008-10-07T23:59:59.000Z

249

Cupric Siliconiobate. Synthesis and Solid-State Studies of a Pseudosandwich-Type Heteropolyanion  

SciTech Connect

The Na{sup +} and [Cu(en){sub 2}(H{sub 2}O){sub 2}]{sup 2+} (en = ethylenediamine) salt of a pseudosandwich-type heteropolyniobate forms upon prolonged heating of Cu(NO{sub 3}){sub 2} and hydrated Na{sub 14}[(SiOH){sub 2}Si{sub 2}Nb{sub 16}O{sub 54}] in a mixed water-en solution. The structure [a = 14.992(2) {angstrom}, b = 25.426(4) {angstrom}, c = 30.046(4) {angstrom}, orthorhombic, Pnn2, R1 = 6.04%, based on 25869 unique reflections] consists of two [Na(SiOH){sub 2}Si{sub 2}Nb{sub 16}O{sub 54}]{sup 13-} units linked by six sodium cations, and this sandwich is charge-balanced by five [Cu(en){sub 2}(H{sub 2}O){sub 2}]{sup 2+} complexes, seven protons, and three additional sodium atoms (all per a sandwich-type cluster). Diffuse-reflectance UV-vis indicates that there is a {lambda}{sub max} at 383 nm for the Cu{sup II} d-d transition and the {sup 29}Si MAS NMR spectrum has two peaks at -78.2 ppm (151 Hz) and -75.5 ppm (257 Hz) for the two pairs of symmetry-equivalent internal [SiO{sub 4}]{sup 4-} and external [SiO{sub 3}(OH)]{sup 3-} tetrahedra, respectively. Unlike tungsten-based sandwich-type complexes, the [Na(SiOH){sub 2}Si{sub 2}Nb{sub 16}O{sub 54}]{sup 13-} units are linked exclusively by Na{sup +} instead of one or more d-electron metals.

Anderson, Travis M.; Alam, Todd M.; Rodriguez, Mark A.; Bixler, Joel N.; Xu, Wenqian; Parise, John B.; Nyman, May (SBU)

2008-10-02T23:59:59.000Z

250

VERY-LOW-MASS STELLAR AND SUBSTELLAR COMPANIONS TO SOLAR-LIKE STARS FROM MARVELS. III. A SHORT-PERIOD BROWN DWARF CANDIDATE AROUND AN ACTIVE G0IV SUBGIANT  

SciTech Connect

We present an eccentric, short-period brown dwarf candidate orbiting the active, slightly evolved subgiant star TYC 2087-00255-1, which has effective temperature T{sub eff} = 5903 {+-} 42 K, surface gravity log (g) = 4.07 {+-} 0.16 (cgs), and metallicity [Fe/H] = -0.23 {+-} 0.07. This candidate was discovered using data from the first two years of the Multi-object APO Radial Velocity Exoplanets Large-area Survey, which is part of the third phase of Sloan Digital Sky Survey. From our 38 radial velocity measurements spread over a two-year time baseline, we derive a Keplerian orbital fit with semi-amplitude K = 3.571 {+-} 0.041 km s{sup -1}, period P = 9.0090 {+-} 0.0004 days, and eccentricity e = 0.226 {+-} 0.011. Adopting a mass of 1.16 {+-} 0.11 M{sub Sun} for the subgiant host star, we infer that the companion has a minimum mass of 40.0 {+-} 2.5 M{sub Jup}. Assuming an edge-on orbit, the semimajor axis is 0.090 {+-} 0.003 AU. The host star is photometrically variable at the {approx}1% level with a period of {approx}13.16 {+-} 0.01 days, indicating that the host star spin and companion orbit are not synchronized. Through adaptive optics imaging we also found a point source 643 {+-} 10 mas away from TYC 2087-00255-1, which would have a mass of 0.13 M{sub Sun} if it is physically associated with TYC 2087-00255-1 and has the same age. Future proper motion observation should be able to resolve if this tertiary object is physically associated with TYC 2087-00255-1 and make TYC 2087-00255-1 a triple body system. Core Ca II H and K line emission indicate that the host is chromospherically active, at a level that is consistent with the inferred spin period and measured v{sub rot}sin i, but unusual for a subgiant of this T{sub eff}. This activity could be explained by ongoing tidal spin-up of the host star by the companion.

Ma Bo; Ge Jian; De Lee, Nathan; Fleming, Scott W.; Lee, Brian L.; Wang Ji [Department of Astronomy, University of Florida, 211 Bryant Space Science Center, Gainesville, FL 32611-2055 (United States); Barnes, Rory; Agol, Eric [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195-1580 (United States); Crepp, Justin R. [Department of Physics, University of Notre Dame, 225 Nieuwland Science Hall, Notre Dame, IN 46556 (United States); Dutra-Ferreira, Leticia; Porto de Mello, G. F. [Observatorio do Valongo, Universidade Federal do Rio de Janeiro, Ladeira do Pedro Antonio, 43, CEP: 20080-090, Rio de Janeiro, RJ (Brazil); Esposito, Massimiliano; Femenia, Bruno; Gonzalez Hernandez, Jonay I. [Instituto de Astrofisica de Canarias, C/Via Lctea S/N, E-38200 La Laguna (Spain); Gaudi, B. Scott [Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Ghezzi, Luan [Laboratorio Interinstitucional de e-Astronomia (LIneA), Rio de Janeiro, RJ 20921-400 (Brazil); Hebb, Leslie; Stassun, Keivan G. [Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235 (United States); Wisniewski, John P. [Homer L Dodge Department of Physics and Astronomy, University of Oklahoma, 440 W Brooks St, Norman, OK 73019 (United States); Bizyaev, Dmitry, E-mail: boma@astro.ufl.edu [Apache Point Observatory, P.O. Box 59, Sunspot, NM 88349-0059 (United States); and others

2013-01-01T23:59:59.000Z

251

COSMOLOGICAL EVOLUTION OF ATOMIC GAS AND IMPLICATIONS FOR 21 cm H I ABSORPTION  

SciTech Connect

Galaxy disks are shown to contain a significant population of atomic clouds of 100 pc linear size which are self-opaque in the 21 cm transition. These objects have H I column densities as high as 10{sup 23} cm{sup -2} and contribute to a global opacity correction factor of 1.34 {+-} 0.05 that applies to the integrated 21 cm emission to obtain a total H I mass estimate. High-resolution, opacity-corrected images of the nearest external galaxies have been used to form a robust redshift zero distribution function of H I, f(N{sub HI}, X, z = 0), the probability of encountering a specific H I column density along random lines of sight per unit comoving distance. This is contrasted with previously published determinations of f(N{sub HI}, X) at z = 1 and 3. A systematic decline of moderate column density (18 < log(N{sub H)} < 21) H I is observed with decreasing redshift that corresponds to a decline in surface area of such gas by a factor of five since z = 3. The number of equivalent Damped Lyman Alpha absorbers (log(N{sub HI})>20.3) has also declined systematically over this redshift interval by a similar amount, while the cosmological mass density in such systems has declined by only a factor of two to its current, opacity-corrected value of {Omega}{sup DLA}{sub HI}(z = 0) = 5.4 {+-} 0.9 Multiplication-Sign 10{sup -4}. We utilize the tight but strongly nonlinear dependence of 21 cm absorption opacity on column density at z = 0 to transform our high-resolution H I images into ones of 21 cm absorption opacity. These images are used to calculate distribution and pathlength functions of integrated 21 cm opacity. We suggest that that this z = 0 calibration may also apply at higher redshift. In this case, the incidence of deep 21 cm absorption systems is predicted to show very little evolution with redshift, while that of faint absorbers should decline by a factor of 5 between z = 3 and the present. We explicitly consider the effects of H I absorption against background sources that are extended relative to the 100 pc intervening absorber size scale. Extended background sources result in dramatically altered distribution and pathlength functions which are insensitive to the predicted redshift evolution. Future surveys of 21 cm absorption will require very high angular resolution, of about 15 mas, for their unambiguous interpretation.

Braun, Robert, E-mail: Robert.Braun@csiro.au [CSIRO Astronomy and Space Science, P.O. Box 76, Epping, NSW 1710 (Australia)

2012-04-10T23:59:59.000Z

252

THE SOLAR NEIGHBORHOOD. XXVIII. THE MULTIPLICITY FRACTION OF NEARBY STARS FROM 5 TO 70 AU AND THE BROWN DWARF DESERT AROUND M DWARFS  

Science Conference Proceedings (OSTI)

We report on our analysis of Hubble Space Telescope/NICMOS snapshot high-resolution images of 255 stars in 201 systems within {approx}10 pc of the Sun. Photometry was obtained through filters F110W, F180M, F207M, and F222M using NICMOS Camera 2. These filters were selected to permit clear identification of cool brown dwarfs through methane contrast imaging. With a plate scale of 76 mas pixel{sup -1}, NICMOS can easily resolve binaries with subarcsecond separations in the 19.''5 Multiplication-Sign 19.''5 field of view. We previously reported five companions to nearby M and L dwarfs from this search. No new companions were discovered during the second phase of data analysis presented here, confirming that stellar/substellar binaries are rare. We establish magnitude and separation limits for which companions can be ruled out for each star in the sample, and then perform a comprehensive sensitivity and completeness analysis for the subsample of 138 M dwarfs in 126 systems. We calculate a multiplicity fraction of 0.0{sup +3.5}{sub -0.0}% for L companions to M dwarfs in the separation range of 5-70 AU, and 2.3{sup +5.0}{sub -0.7}% for L and T companions to M dwarfs in the separation range of 10-70 AU. We also discuss trends in the color-magnitude diagrams using various color combinations and present astrometry for 19 multiple systems in our sample. Considering these results and results from several other studies, we argue that the so-called brown dwarf desert extends to binary systems with low-mass primaries and is largely independent of primary mass, mass ratio, and separations. While focusing on companion properties, we discuss how the qualitative agreement between observed companion mass functions and initial mass functions suggests that the paucity of brown dwarfs in either population may be due to a common cause and not due to binary formation mechanisms.

Dieterich, Sergio B.; Henry, Todd J. [Department of Physics and Astronomy, Georgia State University, Atlanta, GA 30302-4106 (United States); Golimowski, David A. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Krist, John E. [Jet Propulsion Laboratory, Pasadena, CA 91109 (United States); Tanner, Angelle M., E-mail: dieterich@chara.gsu.edu [Department of Physics and Astronomy, Mississippi State University, Starkville, MS 39762 (United States)

2012-08-15T23:59:59.000Z

253

Proliferation Resistance Evaluation of ACR-1000 Fuel with Minor Actinides  

Science Conference Proceedings (OSTI)

The Global Nuclear Energy Partnership (GNEP) program is to significantly advance the science and technology of nuclear energy systems and to enhance the spent fuel proliferation resistance. It consists of both innovative nuclear reactors and innovative research in separation and transmutation. The merits of nuclear energy are high-density energy, with low environmental impacts (i.e. almost zero greenhouse gas emission). Planned efforts involve near-term and intermediate-term improvements in fuel utilization and recycling in current light water reactors (LWRs) as well as the longer-term development of new nuclear energy systems that offer much improved fuel utilization and proliferation resistance, along with continued advances in operational safety. For future advanced nuclear systems, minor actinides (MA) are viewed more as a resource to be recycled, and transmuted to less hazardous and possibly more useful forms, rather than simply disposed of as a waste stream in an expensive repository facility. MAs can play a much larger part in the design of advanced systems and fuel cycles, not only as additional sources of useful energy, but also as direct contributors to the reactivity control of the systems into which they are incorporated. In this work, an Advanced CANDU Reactor (ACR) fuel unit lattice cell model with 43 UO2 fuel rods will be used to investigate the effectiveness of a Minor Actinide Reduction Approach (MARA) for enhancing proliferation resistance and improving the fuel cycle performance. The main MARA objective is to increase the 238Pu / Pu isotope ratio by using the transuranic nuclides (237Np and 241Am) in the high burnup fuel and thereby increase the proliferation resistance even for a very low fuel burnup. As a result, MARA is a very effective approach to enhance the proliferation resistance for the on power refueling ACR system nuclear fuel. The MA transmutation characteristics at different MA loadings were compared and their impact on neutronics criticality assessed. The concept of MARA, significantly increases the 238Pu/Pu ratio for proliferation resistance, as well as serves as a burnable absorber to hold-down the initial excess reactivity. It is believed that MARA can play an important role in atoms for peace and the intermediate term of nuclear energy reconnaissance

Gray S. Chang

2008-09-01T23:59:59.000Z

254

Quantitative Trait Locus (QTL) Mapping of Transpiration Efficiency Related to Pre-flower Drought Tolerance in Sorghum [Sorghum bicolor (L.) Moench  

E-Print Network (OSTI)

There is an increasing need to improve crop water-use efficiency (WUE) (ratio of whole-plant biomass to cumulative transpiration) due to decreased water availability and increased food and energy demands throughout the world. The objective of the study was to estimate the genetic variation and genetic basis for transpiration efficiency A:E (CO2 assimilation rate (A) divided by transpiration rate (E)) trait and its relationship to WUE related to pre-flower drought tolerance in recombinant inbred lines (RILs) of sorghum and associated QTLs. A greenhouse study was conducted at Bushland, TX, 2008, using 71 RILs derived from cross of Tx430 x Tx7078. A randomized complete block experimental design was used, with both genotype and water regime (40 and 80 percent water regime) as experimental factors, and four replications. Genotype had a significant effect on A, E and A:E under both the environments. Among the RILs, entry means for A:E ranged from 1.58 to 3.07 mmol CO2 mol^-1 H2O and 1.18 to 4.36 mmol CO2 mol^-1 H2O under 80 percent and 40 percent water regime, respectively. Heritability estimates based on individual environments for A:E , A and E were 0.77, 0.45 and 0.37 under 80 percent water regime and 0.90, 0.33 and 0.71 under 40 percent water regime, respectively. A genetic map was constructed by digital genotyping method using Illumina GAII sequencer with 261 informative indel/ single-nucleotide polymorphism (SNP's) markers distributed over 10 linkage groups. Three significant QTLs associated with transpiration efficiency were identified; two on SBI-09 and one on SBI-10 with one logarithmic of odds (LOD) interval length ranging from 5.3 to 5.7 cM and accounting for 17 percent - 21 percent of the phenotypic variation. In field and greenhouse evaluation of agronomic of traits at College Station and Halfway, TX, 91 QTL that control variation in six major agronomic traits such as plant height, flowering, biomass, leaf area, leaf greenness and stomatal density were identified. Co-localization of transpiration efficiency QTLs with agronomic traits such as leaf area, biomass, leaf width and stomatal density indicated that these agronomically important QTLs can be used for further improving the sorghum performance through marker assisted selection (MAS) under pre-flowering drought stress conditions.

Heraganahally Kapanigowda, Mohankumar

2011-05-01T23:59:59.000Z

255

Comparative Genomics of Gossypium spp. through GBS and Candidate Genes – Delving into the Controlling Factors behind Photoperiodic Flowering  

E-Print Network (OSTI)

Cotton has been a world-wide economic staple in textiles and oil production. There has been a concerted effort for cotton improvement to increase yield and quality to compete with non-natural man-made fibers. Unfortunately, cultivated cotton has limited genetic diversity; therefore finding new marketable traits within cultivated cotton has reached a plateau. To alleviate this problem, traditional breeding programs have been attempting to incorporate practical traits from wild relatives into cultivated lines. This incorporation has presented a new problem: uncultivated cotton hampered by photoperiodism. Traditionally, due to differing floral times, wild and cultivated cotton species were unable to be bred together in many commercial production areas world-wide. This worldwide breeding problem has inhibited new trait incorporation. Before favorable traits from undomesticated cotton could be integrated into cultivated elite lines using marker-assisted selection breeding, the markers associated with photoperiod independence needed to be discovered. In order to increase information about this debilitating trait, we set out to identify informative markers associated with photoperiodism. This study was segmented into four areas. First, we reviewed the history of cotton to highlight current problems in production. Next, we explored cotton’s floral development through a study of floral transition candidate genes. The third area was an in-depth analysis of Phytochrome C (previously linked to photoperiod independence in other crops). In the final area of study, we used Genotype-By-Sequencing (GBS), in a segregating population, was used to determine photoperiod independence associated with single nucleotide polymorphisms (SNPs). In short, this research reported SNP differences in thirty-eight candidate gene homologs within the flowering time network, including photoreceptors, light dependent transcripts, circadian clock regulators, and floral integrators. Also, our research linked other discrete SNP differences, in addition to those contained within candidate genes, to photoperiodicity within cotton. In conclusion, the SNP markers that our study found may be used in future marker assisted selection (MAS) breeding schemas to incorporate desirable traits into elite lines without the introgression of photoperiod sensitivity.

Young, Carla Jo Logan

2013-08-01T23:59:59.000Z

256

Assistant template and co-template agents in modeling mesoporous silicas and post-synthesizing organofunctionalizations  

SciTech Connect

Mesoporous SBA-16 silicas were synthesized through a direct methodology using the template (F127) combined with co-templates (ethanol and n-butanol), with tetraethylorthosilicate as the silica source. These ordered mesoporous silica were characterized by elemental analyses, infrared spectroscopy, solid-state nuclear magnetic resonance for {sup 13}C (CP/MAS) and {sup 29}Si (HP/DEC) nuclei, nitrogen sorption/desorption processes, small angle X-ray analyses (SAXS) and transmission electron microscopy (TEM). SAXS and TEM results confirmed the space group Im3m and cubic 3D symmetry, typical for highly ordered SBA-16. The sorption/desorption data for SBA-16 and when functionalized gave type IV isotherms, with hysteresis loop H2. Surface areas of 836; 657 and 618 m{sup 2} g{sup -1} and average pore diameters of 7.99; 8.10 and 9.85 nm, for SBA-16A, SBA-16B and SBA-16C were obtained, respectively. When functionalized the silicas presented a reduction in surface area, pore volume and pore diameter due to the pendant chains that interfere with nitrogen sorption in these measurements. The co-template ethanol favors the ordered mesopores with highest wall thicknesses. - Graphical Abstract: The mesoporous SBA-16 can be synthesized from binary (F127/TEOS) or ternary (F127/alcohol/TEOs) systems to give well-ordered mesoporous silicas. The co-templates ethanol or butanol gave the final material with highest wall thickness, mainly with ethanol. After these syntheses the pores were successfully organofunctionalized to give a good incorporation of the silylating agents. The final silicas presented of well-arranged solid characteristics as expressing by three distinct peaks, as indexed by the corresponding planes. Highlights: Black-Right-Pointing-Pointer Syntheses of mesoporous silicas by using ternary (F127/agent/TEOS) and binary (F127/TEOS) systems. Black-Right-Pointing-Pointer Use of co-templates to synthesize mesoporous silicas with larger wall thicknesses. Black-Right-Pointing-Pointer Immobilization of pendant chains inside the porous silicas. Black-Right-Pointing-Pointer Ordered mesoposous silicas as new materials for possible applications on sorption and delivering drug systems.

Oliveira, Vaeudo V. [Institute of Chemistry, University of Campinas, UNICAMP, PO Box 6154, 13084-971 Campinas, SP (Brazil)] [Institute of Chemistry, University of Campinas, UNICAMP, PO Box 6154, 13084-971 Campinas, SP (Brazil); Airoldi, Claudio, E-mail: airoldi@iqm.unicamp.br [Institute of Chemistry, University of Campinas, UNICAMP, PO Box 6154, 13084-971 Campinas, SP (Brazil)] [Institute of Chemistry, University of Campinas, UNICAMP, PO Box 6154, 13084-971 Campinas, SP (Brazil)

2012-12-15T23:59:59.000Z

257

Tetraphosphine Linker Scaffolds with a Tetraphenyltin Core for Superior Immobilized Catalysts: A Solid-State NMR Study  

E-Print Network (OSTI)

The focus of this work is to synthesize and immobilize novel rigid tetraphosphine linkers via the formation of phosphonium groups and by direct adsorption of tetraphosphine salts on oxide surfaces. These methods offer the possibility to study the mechanism of the phosphonium formation in more detail by utilizing solid-state NMR spectroscopy. It has also been a point of interest to study the linkers and catalysts under realistic conditions, in the presence of solvents. Therefore, HRMAS (high-resolution magic angle spinning) NMR spectra of several phosphonium salts, adsorbed on SiO2, have been studied. This technique allows one to probe the leaching and mobility of the linkers on the surface. The mobilities of the linkers and the catalysts are crucial factors for the performance and design of the immobilized catalysts. Finally, since the exact mode of binding to the surface is unknown and is being discussed in the literature, for example, as hydrogen bonding between the F atoms in BF4- and surface silanol protons, the influence of the counteranion on the binding of phosphonium salts on silica surfaces is of utmost interest. For surface mobility studies a monolayer of phosphonium salts on the silica surface, both without solvent and in the presence of solvent, has been studied via 31P and 2H CP/MAS and HRMAS. Our findings show that the integrity of the tetraphosphine scaffold linkers is based upon how it is immobilized. The best system is formed when the phosphine is immobilized on the SiO2 support by adding Cl(CH2)3Si(OEt)3 to the reaction mixture. In this way, phosphonium salts are obtained, which are bound to the surface irreversibly by electrostatic interactions, as proven by solid-state NMR. In addition, leaching and mobility studies prove that the solvents play a crucial role, and the more polar solvents, such as DMSO, lead to the most extensive leaching due to the solvents' strong adsorption on the SiO2 surface. Leaching studies also show that the counteranion has an influence on the binding of the phosphoniumn salts on the SiO2 surface. The leaching proceeds in the following manner: BF4- > I- > Br- > Cl-. This is an indication that there is an additional interaction between the anion and, most probably, the surface silanol protons.

Perera, Melanie Ingrid

2011-08-01T23:59:59.000Z

258

Quantitative comparison of noise texture across CT scanners from different manufacturers  

SciTech Connect

Purpose: To quantitatively compare noise texture across computed tomography (CT) scanners from different manufacturers using the noise power spectrum (NPS). Methods: The American College of Radiology CT accreditation phantom (Gammex 464, Gammex, Inc., Middleton, WI) was imaged on two scanners: Discovery CT 750HD (GE Healthcare, Waukesha, WI), and SOMATOM Definition Flash (Siemens Healthcare, Germany), using a consistent acquisition protocol (120 kVp, 0.625/0.6 mm slice thickness, 250 mAs, and 22 cm field of view). Images were reconstructed using filtered backprojection and a wide selection of reconstruction kernels. For each image set, the 2D NPS were estimated from the uniform section of the phantom. The 2D spectra were normalized by their integral value, radially averaged, and filtered by the human visual response function. A systematic kernel-by-kernel comparison across manufacturers was performed by computing the root mean square difference (RMSD) and the peak frequency difference (PFD) between the NPS from different kernels. GE and Siemens kernels were compared and kernel pairs that minimized the RMSD and |PFD| were identified. Results: The RMSD (|PFD|) values between the NPS of GE and Siemens kernels varied from 0.01 mm{sup 2} (0.002 mm{sup -1}) to 0.29 mm{sup 2} (0.74 mm{sup -1}). The GE kernels 'Soft,''Standard,''Chest,' and 'Lung' closely matched the Siemens kernels 'B35f,''B43f,''B41f,' and 'B80f' (RMSD < 0.05 mm{sup 2}, |PFD| < 0.02 mm{sup -1}, respectively). The GE 'Bone,''Bone+,' and 'Edge' kernels all matched most closely with Siemens 'B75f' kernel but with sizeable RMSD and |PFD| values up to 0.18 mm{sup 2} and 0.41 mm{sup -1}, respectively. These sizeable RMSD and |PFD| values corresponded to visually perceivable differences in the noise texture of the images. Conclusions: It is possible to use the NPS to quantitatively compare noise texture across CT systems. The degree to which similar texture across scanners could be achieved varies and is limited by the kernels available on each scanner.

Solomon, Justin B.; Christianson, Olav; Samei, Ehsan [Carl E. Ravin Advanced Imaging Laboratories and Clinical Imaging Physics Group, Department of Radiology, Medical Physics Graduate Program, Duke University Medical Center, Durham, North Carolina 27705 (United States); Carl E. Ravin Advanced Imaging Laboratories and Clinical Imaging Physics Group, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Carl E. Ravin Advanced Imaging Laboratories and Clinical Imaging Physics Group, Medical Physics Graduate Program, Departments of Radiology, Physics, Biomedical Engineering, and Electrical and Computer Engineering, Duke University, Durham, North Carolina 27705 (United States)

2012-10-15T23:59:59.000Z

259

KELT-1b: A STRONGLY IRRADIATED, HIGHLY INFLATED, SHORT PERIOD, 27 JUPITER-MASS COMPANION TRANSITING A MID-F STAR  

Science Conference Proceedings (OSTI)

We present the discovery of KELT-1b, the first transiting low-mass companion from the wide-field Kilodegree Extremely Little Telescope-North (KELT-North) transit survey. A joint analysis of the spectroscopic, radial velocity, and photometric data indicates that the V = 10.7 primary is a mildly evolved mid-F star with T{sub eff} = 6516 {+-} 49 K, log g 4.228{sup +0.014}{sub -0.021}, and [Fe/H] = 0.052 {+-} 0.079, with an inferred mass M{sub *} = 1.335 {+-} 0.063 M{sub Sun} and radius R{sub *} 1.471{sup +0.045}{sub -0.035} R{sub Sun }. The companion is a low-mass brown dwarf or a super-massive planet with mass M{sub P} = 27.38 {+-} 0.93 M{sub Jup} and radius R{sub P} = 1.116{sup +0.038}{sub -0.029} R{sub Jup}. The companion is on a very short ({approx}29 hr) period circular orbit, with an ephemeris T{sub c} (BJD{sub TDB}) = 2455909.29280 {+-} 0.00023 and P = 1.217501 {+-} 0.000018 days. KELT-1b receives a large amount of stellar insolation, resulting in an estimated equilibrium temperature assuming zero albedo and perfect redistribution of T{sub eq} = 2423{sup +34}{sub -27} K. Comparison with standard evolutionary models suggests that the radius of KELT-1b is likely to be significantly inflated. Adaptive optics imaging reveals a candidate stellar companion to KELT-1 with a separation of 588 {+-} 1 mas, which is consistent with an M dwarf if it is at the same distance as the primary. Rossiter-McLaughlin measurements during transit imply a projected spin-orbit alignment angle {lambda} = 2 {+-} 16 deg, consistent with a zero obliquity for KELT-1. Finally, the vsin I{sub *} = 56 {+-} 2 km s{sup -1} of the primary is consistent at {approx}2{sigma} with tidal synchronization. Given the extreme parameters of the KELT-1 system, we expect it to provide an important testbed for theories of the emplacement and evolution of short-period companions, as well as theories of tidal dissipation and irradiated brown dwarf atmospheres.

Siverd, Robert J.; Pepper, Joshua; Stassun, Keivan G. [Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235 (United States); Beatty, Thomas G.; Scott Gaudi, B. [Department of Astronomy, Ohio State University, 140 W. 18th Avenue, Columbus, OH 43210 (United States); Eastman, Jason D.; Street, Rachel; Fulton, Benjamin J. [Las Cumbres Observatory Global Telescope Network, 6740 Cortona Drive, Suite 102, Santa Barbara, CA 93117 (United States); Collins, Karen [Department of Physics and Astronomy, University of Louisville, Louisville, KY 40292 (United States); Bieryla, Allyson; Latham, David W.; Berlind, Perry; Calkins, Michael L.; Esquerdo, Gilbert A.; Furesz, Gabor; Geary, John C. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Buchhave, Lars A. [Niels Bohr Institute, University of Copenhagen, Juliane Maries vej 30, DK-21S00 Copenhagen (Denmark); Jensen, Eric L. N. [Department of Physics and Astronomy, Swarthmore College, Swarthmore, PA 19081 (United States); Crepp, Justin R. [Department of Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); DePoy, D. L. [Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States); and others

2012-12-20T23:59:59.000Z

260

Enhancing BWR Proliferation Resistance Fuel with Minor Actinides  

SciTech Connect

To reduce spent fuel for storage and enhance the proliferation resistance for the intermediate-term, there are two major approaches (a) increase the discharged spent fuel burnup in the advanced light water reactor- LWR (Gen-III Plus), which not only can reduce the spent fuel for storage, but also increase the 238Pu isotopes ratio to enhance the proliferation resistance, and (b) use of transuranic nuclides (237Np and 241Am) in the high burnup fuel, which can drastically increase the proliferation resistance isotope ratio of 238Pu/Pu. For future advanced nuclear systems, minor actinides (MA) are viewed more as a resource to be recycled, and transmuted to less hazardous and possibly more useful forms, rather than simply disposed of as a waste stream in an expensive repository facility. As a result, MAs play a much larger part in the design of advanced systems and fuel cycles, not only as additional sources of useful energy, but also as direct contributors to the reactivity control of the systems into which they are incorporated. In the study, a typical boiling water reactor (BWR) fuel unit lattice cell model with UO2 fuel pins will be used to investigate the effectiveness of minor actinide reduction approach (MARA) for enhancing proliferation resistance and improving the fuel cycle performance in the intermediate-term goal for future nuclear energy systems. To account for the water coolant density variation from the bottom (0.76 g/cm3) to the top (0.35 g/cm3) of the core, the axial coolant channel and fuel pin were divided to 24 nodes. The MA transmutation characteristics at different elevations were compared and their impact on neutronics criticality discussed. The concept of MARA, which involves the use of transuranic nuclides (237Np and/or 241Am), significantly increases the 238Pu/Pu ratio for proliferation resistance, as well as serves as a burnable absorber to hold-down the initial excess reactivity. It is believed that MARA can play an important role in atoms for peace and the intermediate-term of nuclear energy reconnaissance.

Gray S. Chang

2009-03-01T23:59:59.000Z

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261

Irradiation Planning for Fully-Ceramic Micro-encsapsulated fuel in ATR at LWR-relevant conditions: year-end report on FY-2011  

SciTech Connect

This report presents the estimation of required ATR irradiation levels for the DB-FCM fuel design (fueled with Pu and MAs). The fuel and assembly designs are those considered in a companion report [R. S. Sen et al., FCR&D-2011- 00037 or INL/EXT-11-23269]. These results, pertaining to the DB-FCM fuel, are definitive in as much as the design of said fuel is definitive. In addition to the work performed, as required, for DB-FCM fuel, work has started in a preliminary fashion on single-cell UO2 and UN fuels. These latter activities go beyond the original charter of this project and although the corresponding work is incomplete, significant progress has been achieved. However, in this context, all that has been achieved is only preliminary because the corresponding fuel designs are neither finalized nor optimized. In particular, the UO2 case is unlikely to result in a viable fuel design if limited to enrichment at or under 20 weight % in U-235. The UN fuel allows reasonable length cycles and is likely to make an optimal design possible. Despite being limited to preliminary designs and offering only preliminary conclusions, the irradiation planning tasks for UO2 and UN fuels that are summarized in this report are useful to the overall goal of devising and deploying FCM-LWR fuel since the methods acquired and tested in this project and the overall procedure for planning will be available for planning tests for the finalized fuel design. Indeed, once the fuel design is finalized and the expected burnup level is determined, the methodology that has been assembled will allow the prompt finalization of the neutronic planning of the irradiation experiment and would provide guidance on the expected experimental performance of the fuel. Deviations from the expected behavior will then have to be analyzed and the outcome of the analysis may be corrections or modifications for the assessment models as well as, possibly, fuel design modifications, and perhaps even variation of experimental control for future experimental phases. Besides the prediction of irradiation times, preliminary work was carried out on other aspects of irradiation planning. In particular, a method for evaluating the interplay of depletion, material performance modeling and irradiation is identified by reference to a companion report. Another area that was addressed in a preliminary fashion is the identification and selection of a strategy for the physical and mechanical design of the irradiation experiments. The principal conclusion is that the similarity between the FCM fuel and the fuel compacts of the Next Generation Nuclear Plant prismatic design are strong enough to warrant using irradiation hardware designs and instrumentation adapted from the AGR irradiation tests. Modifications, if found necessary, will probably be few and small, except as pertains to the water environment and its implications on the use of SiC cladding or SiC matrix with no additional cladding.

Abderrafi M. Ougouag; R. Sonat Sen; Michael A. Pope; Brian Boer

2011-09-01T23:59:59.000Z

262

Crystal-chemistry of mullite-type aluminoborates Al{sub 18}B{sub 4}O{sub 33} and Al{sub 5}BO{sub 9}: A stoichiometry puzzle  

SciTech Connect

Orthorhombic Al{sub 2}O{sub 3}-rich aluminoborate is an important ceramic material for which two slightly different compositions have been assumed: Al{sub 5}BO{sub 9} (5Al{sub 2}O{sub 3}:B{sub 2}O{sub 3}) and Al{sub 18}B{sub 4}O{sub 33} (9Al{sub 2}O{sub 3}:2B{sub 2}O{sub 3}). The formula Al{sub 18}B{sub 4}O{sub 33} (=Al{sub 4.91}B{sub 1.09}O{sub 9}) was derived from results of chemical analyses when crystal structure data were not yet available. Subsequent structural investigations indicated Al{sub 5}BO{sub 9} composition. Nevertheless, Al{sub 18}B{sub 4}O{sub 33} was still accepted as the correct stoichiometry assuming that additional B replaces 9% Al. Powder samples of both compositions and ones with excess boron were prepared by solid state reactions between {alpha}-Al{sub 2}O{sub 3} and B{sub 2}O{sub 3}/H{sub 3}BO{sub 3} at temperatures above 1100 {sup o}C and single-crystals were grown from flux at 1100 and 1550 {sup o}C. Products were investigated by single-crystal and powder XRD, {sup 11}B and {sup 27}Al solid-state MAS-NMR, Raman and FTIR spectroscopy as well as Laser-ablation ICP-MS. No indication of the predicted 9% B{yields}Al substitution was found. LA ICP-MS indicated 12.36(27) wt% B{sub 2}O{sub 3} corresponding to Al{sub 4.97}B{sub 1.03}O{sub 9}. Hence, the suggested Al{sub 18}B{sub 4}O{sub 33} stoichiometry can be excluded for all synthesized samples. A very low amount of Al vacancies at a five-fold coordinated site are likely, charge balanced by an additional nearby three-fold coordinated B site. All evidences indicate that the title compound should be reported as Al{sub 5-x}B{sub 1+x}O{sub 9} with x<0.038(6), which is close to Al{sub 5}BO{sub 9}. -- Graphical abstract: A chemical composition of Al{sub 18}B{sub 4}O{sub 33}=Al{sub 4.91}B{sub 1.09}O{sub 9}=9Al{sub 2}O{sub 3}:2B{sub 2}O{sub 3} has been assumed for mullite-type aluminoborate with Al{sub 5}BO{sub 9} structure. However, samples prepared by different routes showed compositions close to 5Al{sub 2}O{sub 3}:B{sub 2}O{sub 3}. Display Omitted

Fisch, Martin, E-mail: fisch@krist.unibe.c [Mineralogical Crystallography, Institute of Geological Sciences, University of Bern, Freiestrasse 3, CH-3012 Bern (Switzerland); Armbruster, Thomas [Mineralogical Crystallography, Institute of Geological Sciences, University of Bern, Freiestrasse 3, CH-3012 Bern (Switzerland); Rentsch, Daniel [EMPA, Swiss Federal Laboratories for Materials Science and Research, Laboratory for Functional Polymers, Uberlandstrasse 129, CH-8600 Duebendorf (Switzerland); Libowitzky, Eugen [Institut fuer Mineralogie und Kristallographie, Universitaet Wien - Geozentrum, Althanstrasse 14, A-1090 Wien (Austria); Pettke, Thomas [Rock-Water Interaction Group, Institute of Geological Sciences, University of Bern, Baltzerstrasse 1-3, CH-3012 Bern (Switzerland)

2011-01-15T23:59:59.000Z

263

PROPER MOTIONS OF THE ARCHES CLUSTER WITH KECK LASER GUIDE STAR ADAPTIVE OPTICS: THE FIRST KINEMATIC MASS MEASUREMENT OF THE ARCHES  

SciTech Connect

We report the first detection of the intrinsic velocity dispersion of the Arches cluster-a young ({approx}2 Myr), massive (10{sup 4} M{sub Sun }) starburst cluster located only 26 pc in projection from the Galactic center. This was accomplished using proper motion measurements within the central 10'' Multiplication-Sign 10'' of the cluster, obtained with the laser guide star adaptive optics system at Keck Observatory over a three-year time baseline (2006-2009). This uniform data set results in proper motion measurements that are improved by a factor {approx}5 over previous measurements from heterogeneous instruments. By careful, simultaneous accounting of the cluster and field contaminant distributions as well as the possible sources of measurement uncertainties, we estimate the internal velocity dispersion to be 0.15 {+-} 0.01 mas yr{sup -1}, which corresponds to 5.4 {+-} 0.4 km s{sup -1} at a distance of 8.4 kpc. Projecting a simple model for the cluster onto the sky to compare with our proper motion data set, in conjunction with surface density data, we estimate the total present-day mass of the cluster to be M(r < 1.0 pc) = 1.5{sup +0.74}{sub -0.60} Multiplication-Sign 10{sup 4} M{sub Sun }. The mass in stars observed within a cylinder of radius R (for comparison to photometric estimates) is found to be M(R < 0.4 pc) = 0.90{sup +0.40}{sub -0.35} Multiplication-Sign 10{sup 4} M{sub Sun} at formal 3{sigma} confidence. This mass measurement is free from assumptions about the mass function of the cluster, and thus may be used to check mass estimates from photometry and simulation. Photometric mass estimates assuming an initially Salpeter mass function ({Gamma}{sub 0} = 1.35, or {Gamma} {approx} 1.0 at present, where dN/d(log M){proportional_to}M{sup {Gamma}}) suggest a total cluster mass M{sub cl} {approx} (4-6) Multiplication-Sign 10{sup 4} M{sub Sun} and projected mass ({approx} 2 {<=} M(R < 0.4 pc) {<=} 3) Multiplication-Sign 10{sup 4} M{sub Sun }. Photometric mass estimates assuming a globally top-heavy or strongly truncated present-day mass function (PDMF; with {Gamma} {approx} 0.6) yield mass estimates closer to M(R < 0.4 pc) {approx} 1-1.2 Multiplication-Sign 10{sup 4} M{sub Sun }. Consequently, our results support a PDMF that is either top-heavy or truncated at low mass, or both. Collateral benefits of our data and analysis include: (1) cluster membership probabilities, which may be used to extract a clean-cluster sample for future photometric work; (2) a refined estimate of the bulk motion of the Arches cluster with respect to the field, which we find to be 172 {+-} 15 km s{sup -1}, which is slightly slower than suggested by previous measurements using one epoch each with the Very Large Telescope and the Keck telescope; and (3) a velocity dispersion estimate for the field itself, which is likely dominated by the inner Galactic bulge and the nuclear disk.

Clarkson, W. I. [Division of Astronomy and Astrophysics, University of California, Los Angeles, Physics and Astronomy Building, 430 Portola Plaza, Box 951547, Los Angeles, CA 90095-1547 (United States); Ghez, A. M.; Morris, M. R.; Yelda, S. [Department of Astronomy, Indiana University, Bloomington, 727 East 3rd Street, Swain West 319, Bloomington, IN 47405-7105 (United States); Lu, J. R. [Institute for Astronomy, 2680 Woodlawn Drive, Honolulu, HI 96822-1839 (United States); Stolte, A. [Argelander Institut fuer Astronomie, Universitaet Bonn, Auf dem Huegel 71, 53121 Bonn (Germany); McCrady, N. [Department of Physics and Astronomy, University of Montana, 32 Campus Drive, No. 1080, Missoula, MT 59812 (United States); Do, T., E-mail: wiclarks@indiana.edu [Department of Physics and Astronomy, University of California, Irvine, 4129 Frederick Reines Hall, Irvine, CA 92697-4575 (United States)

2012-06-01T23:59:59.000Z

264

Tridentate Phosphine Linkers for Immobilized Catalysts: Development and Characterization of Immobilized Rhodium Complexes and Solid-State NMR Studies of Polymers  

E-Print Network (OSTI)

The major directions of this thesis involve (1) the synthesis, immobilization, and characterization of tridentate phosphine linkers on silica, (2) the study of unprecedented Si2C bond cleavage in Rh and Ir phosphine complexes, and (3) the study of performance polymers with solid2state NMR techniques. First a brief overview of solid2state NMR and its relevance to the various areas of chemistry covered in this thesis is given. Following the synthesis, immobilization, and characterization of tridentate phosphine ligands, EtOSi[(CH2)nPPh2]3 (n = 4, 7, 11) and [MeP((CH2)nPPh2)3]+I? (n = 4, 7, 11) on silica is detailed. Both, immobilization by electrostatic interactions and by a covalent siloxane bond to the support, is studied and compared. Ligand exchange with Wilkinson?s catalyst affords immobilized Rh complexes. These materials are applied to catalytic olefin hydrogenation. In either case active hydrogenation catalysts are obtained that can easily and efficiently be recycled up to 30 times. Detailed investigations reveal that irrespective of the linkage to the support the catalysts consist initially of well2defined molecular species that form supported Rh nanoparticles with a narrow size distribution in the course of the catalytic reaction. The nanoparticles are active hydrogenation catalysts as well, and no metal leaching into solution is detected. The reaction of the tridentate phosphine ligands EtOSi[(CH2)2PPh2]3 and MeSi[(CH2)2PPh2]3 with Rh and Ir complexes is investigated. This reaction does not lead to the anticipated Wilkinson2type complexes with the metal in the +I oxidation state, but instead to oxidative addition of the C(sp3)2Si bond to Rh or Ir centers to yield octahedral complexes with the metal in the +III oxidation state. These complexes are fully characterized by multinuclear NMR in solution and in the solid state. Preliminary density functional theory (DFT) calculations corroborate the preference for oxidative addition. Subsequently the study of performance thermoplastics which are important materials for the oil and gas industry is presented. The polymer morphology is studied by solid2state NMR techniques. Special attention is devoted to potential decomposition pathways at elevated temperatures for polyetheretherketone (PEEK) and polyphenylene sulfide (PPS) polymers. 13C CP/MAS (cross polarization with magic angle spinning) NMR and IR spectroscopy reveal that PEEK polymers show no detectable chemical change on the molecular level, while PPS polymers display signs of oxidation of the thioether group and branching via formation of ether, thioether, and biphenyl linkages. Furthermore, the water absorption of polybenzimidazole (PBI), polyetherketoneketone (PEKK), and their blend PEKK2PBI is studied. It is demonstrated that steam2treatment even at high temperatures and pressures does not cause chemical decomposition and that the changes, which are morphological in nature, are fully reversible.

Guenther, Johannes 1983-

2012-12-01T23:59:59.000Z

265

Dynamic volume vs respiratory correlated 4DCT for motion assessment in radiation therapy simulation  

SciTech Connect

Purpose: Conventional (i.e., respiratory-correlated) 4DCT exploits the repetitive nature of breathing to provide an estimate of motion; however, it has limitations due to binning artifacts and irregular breathing in actual patient breathing patterns. The aim of this work was to evaluate the accuracy and image quality of a dynamic volume, CT approach (4D{sub vol}) using a 320-slice CT scanner to minimize these limitations, wherein entire image volumes are acquired dynamically without couch movement. This will be compared to the conventional respiratory-correlated 4DCT approach (RCCT). Methods: 4D{sub vol} CT was performed and characterized on an in-house, programmable respiratory motion phantom containing multiple geometric and morphological ''tumor'' objects over a range of regular and irregular patient breathing traces obtained from 3D fluoroscopy and compared to RCCT. The accuracy of volumetric capture and breathing displacement were evaluated and compared with the ground truth values and with the results reported using RCCT. A motion model was investigated to validate the number of motion samples needed to obtain accurate motion probability density functions (PDF). The impact of 4D image quality on this accuracy was then investigated. Dose measurements using volumetric and conventional scan techniques were also performed and compared. Results: Both conventional and dynamic volume 4DCT methods were capable of estimating the programmed displacement of sinusoidal motion, but patient breathing is known to not be regular, and obvious differences were seen for realistic, irregular motion. The mean RCCT amplitude error averaged at 4 mm (max. 7.8 mm) whereas the 4D{sub vol} CT error stayed below 0.5 mm. Similarly, the average absolute volume error was lower with 4D{sub vol} CT. Under irregular breathing, the 4D{sub vol} CT method provides a close description of the motion PDF (cross-correlation 0.99) and is able to track each object, whereas the RCCT method results in a significantly different PDF from the ground truth, especially for smaller tumors (cross-correlation ranging between 0.04 and 0.69). For the protocols studied, the dose measurements were higher in the 4D{sub vol} CT method (40%), but it was shown that significant mAs reductions can be achieved by a factor of 4-5 while maintaining image quality and accuracy. Conclusions: 4D{sub vol} CT using a scanner with a large cone-angle is a promising alternative for improving the accuracy with which respiration-induced motion can be characterized, particularly for patients with irregular breathing motion. This approach also generates 4DCT image data with a reduced total scan time compared to a RCCT scan, without the need for image binning or external respiration signals within the 16 cm scan length. Scan dose can be made comparable to RCCT by optimization of the scan parameters. In addition, it provides the possibility of measuring breathing motion for more than one breathing cycle to assess stability and obtain a more accurate motion PDF, which is currently not feasible with the conventional RCCT approach.

Coolens, Catherine; Bracken, John; Driscoll, Brandon; Hope, Andrew; Jaffray, David [Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario M5G 2M9, Canada and Department of Radiation Oncology, University of Toronto, Toronto, Ontario M5S 3S2 (Canada); Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario M5G 2M9 (Canada); Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario M5G 2M9, Canada and Department of Radiation Oncology, University of Toronto, Toronto, Ontario M5S 3S2 (Canada); Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario M5G 2M9 (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario M5S 3S2 (Canada) and Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5G 2M9 (Canada)

2012-05-15T23:59:59.000Z

266

The Milky Way Tomography with SDSS. 2. Stellar Metallicity  

Science Conference Proceedings (OSTI)

In addition to optical photometry of unprecedented quality, the Sloan Digital Sky Survey (SDSS) is producing a massive spectroscopic database which already contains over 280,000 stellar spectra. Using effective temperature and metallicity derived from SDSS spectra for {approx}60,000 F and G type main sequence stars (0.2 < g-r < 0.6), we develop polynomial models, reminiscent of traditional methods based on the UBV photometry, for estimating these parameters from the SDSS u-g and g-r colors. These estimators reproduce SDSS spectroscopic parameters with a root-mean-square scatter of 100 K for effective temperature, and 0.2 dex for metallicity (limited by photometric errors), which are similar to random and systematic uncertainties in spectroscopic determinations. We apply this method to a photometric catalog of coadded SDSS observations and study the photometric metallicity distribution of {approx}200,000 F and G type stars observed in 300 deg{sup 2} of high Galactic latitude sky. These deeper (g < 20.5) and photometrically precise ({approx}0.01 mag) coadded data enable an accurate measurement of the unbiased metallicity distribution for a complete volume-limited sample of stars at distances between 500 pc and 8 kpc. The metallicity distribution can be exquisitely modeled using two components with a spatially varying number ratio, that correspond to disk and halo. The best-fit number ratio of the two components is consistent with that implied by the decomposition of stellar counts profiles into exponential disk and power-law halo components by Juric et al. (2008). The two components also possess the kinematics expected for disk and halo stars. The metallicity of the halo component can be modeled as a spatially invariant Gaussian distribution with a mean of [Fe/H] = -1.46 and a standard deviation of {approx}0.3 dex. The disk metallicity distribution is non-Gaussian, with a remarkably small scatter (rms {approx}0.16 dex) and the median smoothly decreasing with distance from the plane from -0.6 at 500 pc to -0.8 beyond several kpc. Similarly, we find using proper motion measurements that a non-Gaussian rotational velocity distribution of disk stars shifts by {approx}50 km/s as the distance from the plane increases from 500 pc to several kpc. Despite this similarity, the metallicity and rotational velocity distributions of disk stars are not correlated (Kendall's {tau} = 0.017 {+-} 0.018). This absence of a correlation between metallicity and kinematics for disk stars is in a conflict with the traditional decomposition in terms of thin and thick disks, which predicts a strong correlation ({tau} = ?0.30 {+-} 0.04) at {approx}1 kpc from the mid-plane. Instead, the variation of the metallicity and rotational velocity distributions can be modeled using non-Gaussian functions that retain their shapes and only shift as the distance from the mid-plane increases. We also study the metallicity distribution using a shallower (g < 19.5) but much larger sample of close to three million stars in 8500 sq. deg. of sky included in SDSS Data Release 6. The large sky coverage enables the detection of coherent substructures in the kinematics-metallicity space, such as the Monoceros stream, which rotates faster than the LSR, and has a median metallicity of [Fe/H] = ?0.95, with an rms scatter of only {approx}0.15 dex. We extrapolate our results to the performance expected from the Large Synoptic Survey Telescope (LSST) and estimate that the LSST will obtain metallicity measurements accurate to 0.2 dex or better, with proper motion measurements accurate to {approx}0.2-0.5 mas/yr, for about 200 million F/G dwarf stars within a distance limit of {approx}100 kpc (g < 23.5).

Ivezic, Zeljko; /Washington U., Seattle; Sesar, Branimir; /Washington U., Seattle; Juric, Mario; /Princeton, Inst. Advanced Study; Bond, Nicholas; /Princeton U.; Dalcanton, Julianne; /Washington U., Seattle; Rockosi, Constance M.; /UC, Santa Cruz; Yanny, Brian; /Fermilab; Newberg, Heidi J.; /Rensselaer Poly.; Beers, Timothy C.; /Michigan State U.; Prieto, Carlos Allende; /Texas U.; Wilhelm, Ron; /Texas Tech. /Michigan State U.

2008-04-01T23:59:59.000Z

267

Analytical investigation of AlCl[3]/SO[2]Cl[2] catholyte materials for secondary fuze reserve batteries.  

DOE Green Energy (OSTI)

Exploration of the fundamental chemical behavior of the AlCl{sub 3}/SO{sub 2}Cl{sub 2} catholyte system for the ARDEC Self-Destruct Fuze Reserve Battery Project under accelerated aging conditions was completed using a variety of analytical tools. Four different molecular species were identified in this solution, three of which are major. The relative concentrations of the molecular species formed were found to depend on aging time, initial concentrations, and storage temperature, with each variable affecting the kinetics and thermodynamics of this complex reaction system. We also evaluated the effect of water on the system, and determined that it does not play a role in dictating the observed molecular species present in solution. The first Al-containing species formed was identified as the dimer [Al({mu}-Cl)Cl{sub 2}]{sub 2}, and was found to be in equilibrium with the monomer, AlCl{sub 3}. The second species formed in the reaction scheme was identified by single crystal X-ray diffraction studies as [Cl{sub 2}Al({mu}-O{sub 2}SCl)]{sub 2} (I), a scrambled AlCl{sub 3}{center_dot}SO{sub 2} adduct. The SO{sub 2}(g) present, as well as CL{sub 2}(g), was formed through decomposition of SO{sub 2}CL{sub 2}. The SO{sub 2}(g) generated was readily consumed by AlCl{sub 3} to form the adduct 1 which was experimentally verified when 1 was also isolated from the reaction of SO{sub 2}(g) and AlCl {sub 3}. The third species found was tentatively identified as a compound having the general formula {l_brace}[Al(O)Cl{sub 2}][OSCl{sub 2}]{r_brace}{sub n}. This was based on {sup 27}Al NMR data that revealed a species with tetrahedrally coordinated Al metal centers with increased oxygen coordination and the fact that the precipitate, or gel, that forms over time was shown by Raman spectroscopic studies to possess a component that is consistent with SOCl{sub 2}. The precursor to the precipitate should have similar constituents, thus the assignment of {l_brace}[Al(O)Cl{sub 2}][OSCl{sub 2}]{r_brace}{sub n}. The precipitate was further identified by solid state {sup 27}Al MAS NMR data to possess predominantly octahedral A1 metal center which implies {l_brace}[Al(O)Cl{sub 2}][OSCl{sub 2}]{r_brace}{sub n} must undergo some internal rearrangements. A reaction sequence has been proposed to account for the various molecular species identified in this complex reaction mixture during the aging process. The metallurgical welds were of high quality. These results were all visually determined there was no mechanical testing performed. However, it is recommended that the end plate geometry and weld be changed. If the present weld strength, based on .003' - .005' penetration, is sufficient for unit performance, the end plate thickness can be reduced to .005' instead of the .020' thickness. This will enable the plug to be stamped so that it can form a cap rather than a plug and solve existing problems and increase the amount of catholyte which may be beneficial to battery performance.

Butler, Paul Charles; Rodriguez, Mark Andrew; Segall, Judith M.; Malizia, Louis A., Jr.; Cherry, Brian Ray; Andrews, Nicholas L.; Clark, Nancy H.; Alam, Todd Michael; Ingersoll, David T.; Tallant, David Robert; Simpson, Regina Lynn; Boyle, Timothy J.; Garcia, Manuel Joseph

2004-05-01T23:59:59.000Z

268

Enhancing BWR Proliferation Resistance Fuel with Minor Actinides  

Science Conference Proceedings (OSTI)

Key aspects of the Global Nuclear Energy Partnership (GNEP) are to significantly advance the science and technology of nuclear energy systems and the Advanced Fuel Cycle (AFC) program. It consists of both innovative nuclear reactors and innovative research in separation and transmutation. To accomplish these goals, international cooperation is very important and public acceptance is crucial. The merits of nuclear energy are high-density energy, with low environmental impacts (i.e. almost zero greenhouse gas emission). Planned efforts involve near-term and intermediate-term improvements in fuel utilization and recycling in current light water reactors (LWRs) as well as the longer-term development of new nuclear energy systems that offer much improved fuel utilization and proliferation resistance, along with continued advances in operational safety. The challenges are solving the energy needs of the world, protection against nuclear proliferation, the problem of nuclear waste, and the global environmental problem. To reduce spent fuel for storage and enhance the proliferation resistance for the intermediate-term, there are two major approaches (a) increase the discharged spent fuel burnup in the advanced LWR (Gen-III Plus), which not only can reduce the spent fuel for storage, but also increase the 238Pu and 240Pu isotopes ratio to enhance the proliferation resistance, and (b) use of transuranic nuclides (237Np and 241Am) in the high burnup fuel, which can drastically increase the proliferation resistance isotope ratio of 238Pu /Pu. For future advanced nuclear systems, the minor actinides (MA) are viewed more as a resource to be recycled, or transmuted to less hazardous and possibly more useful forms, rather than simply as a waste stream to be disposed of in expensive repository facilities. As a result, MAs play a much larger part in the design of advanced systems and fuel cycles, not only as additional sources of useful energy, but also as direct contributors to the reactivity control of the systems into which they are incorporated. In the study, a typical boiling water reactor (BWR) fuel unit lattice cell model with UO2 fuel pins will be used to investigate the effectiveness of minor actinide reduction approach (MARA) for enhancing proliferation resistance and improving the fuel cycle performance in the intermediate term goal for future nuclear energy systems. To account for the water coolant density variation from the bottom (0.76 g/cm3) to the top (0.35 g/cm3) of the core, the axial coolant channel and fuel pin were divided to 24 nodes. The MA transmutation characteristics at different elevations were compared and their impact on neutronics criticality discussed. We concluded that the concept of MARA, which involves the use of transuranic nuclides (237Np and/or 241Am), significantly increases the 238Pu/Pu ratio for proliferation resistance, as well as serves as a burnable absorber to hold-down the initial excess reactivity. It is believed that MARA can play an important role in atoms for peace and the intermediate term of nuclear energy rennaissance.

Gray S. Chang

2008-07-01T23:59:59.000Z