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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

UAM. Cartoteca "Rafael Mas". Inventario, 2011 2 UAM. Cartoteca "Rafael Mas". Inventario, 2011 3  

E-Print Network [OSTI]

#12;UAM. Cartoteca "Rafael Mas". Inventario, 2011 2 #12;UAM. Cartoteca "Rafael Mas". Inventario Madrid. En 2008 se incorporaron, también como donación de la #12;UAM. Cartoteca "Rafael Mas". Inventario://biblioteca.uam.es - Este inventario, disponible en soporte papel y en la red, en la dir

Autonoma de Madrid, Universidad

2

MAS 07 Multi-Class SVM for Forestry Classification MAS 07.1 Overview  

E-Print Network [OSTI]

MAS 07 Multi-Class SVM for Forestry Classification MAS 07.1 Overview In this project, we propose (IFN). We will show one example on a national forest near Sedan (in France), and compare our result binary SVMs. In this project we use the One-Against-All (OAA) scheme, which consists of building one SVM

California at Los Angeles, University of

3

Magnesium Silicate Dissolution Investigated by 29Si MAS, 1H-29Si...  

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

Silicate Dissolution Investigated by 29Si MAS, 1H-29Si CP MAS, 25Mg QCPMG, and 1H-25Mg CP QCPMG NMR. Magnesium Silicate Dissolution Investigated by 29Si MAS, 1H-29Si CP MAS, 25Mg...

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

SCHOOL OF MATHEMATICS AND STATISTICS Spring Semester MAS273 Statistical Modelling 2 hours  

E-Print Network [OSTI]

Continued #12;MAS273 3 (i) Agriculturists in Sheffield were interested in the effectiveness of 3 insectiMAS273 SCHOOL OF MATHEMATICS AND STATISTICS Spring Semester 2012­2013 MAS273 Statistical Modelling

6

MAS 10.1 Implementation of the Integrated Safety Management System...  

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

MAS 10.1 Implementation of the Integrated Safety Management System (ISMS) Process in Maintenance Activities, 2142000 MAS 10.1 Implementation of the Integrated Safety Management...

7

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

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

MAS10-03.doc More Documents & Publications DOE-STD-1064-94 MAS 10.2 Control of Measuring and Test Equipment, 3995 OSS 19.5 Hazardous Waste Operations and Emergency...

8

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

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

2 Control of Measuring and Test Equipment, 3995 MAS 10.2 Control of Measuring and Test Equipment, 3995 The objective of this surveillance is to verify that the contractor...

9

Higher Order Amyloid Fibril Structure by MAS NMR and DNP Spectroscopy  

E-Print Network [OSTI]

Protein magic angle spinning (MAS) NMR spectroscopy has generated structural models of several amyloid fibril systems, thus providing valuable information regarding the forces and interactions that confer the extraordinary ...

Debelouchina, Galia T.

10

E-Print Network 3.0 - antecesores vivos mas Sample Search Results  

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

88 ESTAMOS COMENZANDO AANDAR,por M. SOLER -3 ENTREVISTA A FRANCISCO J.AYALA, por A. MOYA -5 Summary: burocrticas lo son, al menos para mi), y solucionar algunos proble- mas...

11

Managing water demand as a regulated open MAS. (Work in progress)  

E-Print Network [OSTI]

1 Managing water demand as a regulated open MAS. (Work in progress) Vicente Botti1 , Antonio Scientific Research Council, {vbotti,agarridot,agiret}@dsic.upv.es, pablo@iiia.csic.es I. WATER MANAGEMENT management models are based on equa- tional descriptions of aggregate supply and demand in a water basin [2

Garrido, Antonio

12

Managing water demand as a regulated open MAS. (Work in progress)  

E-Print Network [OSTI]

1 Managing water demand as a regulated open MAS. (Work in progress) Vicente Botti 1 , Antonio Scientific Research Council, {vbotti,agarridot,agiret}@dsic.upv.es, pablo@iiia.csic.es I. WATER MANAGEMENT management models are based on equa­ tional descriptions of aggregate supply and demand in a water basin [2

Garrido, Antonio

13

Slow-MAS NMR: A New Technology for In Vivo Metabolomic Studies. | EMSL  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administrationcontroller systemsBiSite Cultural Resourcestepidum FMO *IncreasingSlowSlow-MAS NMR: A

14

X-mas trees: A new application for duplex stainless steels  

SciTech Connect (OSTI)

The development of fields in severe areas (subsea installations, deserts) necessitates the use of materials which can operate maintenance free in these conditions. Depending on production route and aggressivity of relevant media, the materials used until now, such as AISI 4130, are being superseded by higher alloyed materials such as F6NM, Duplex and Super Duplex Steels. Extensive investigation of metallurgical, mechanical, technological and stress aspects as well as research into the influence of melting, forging and heat treatment processes on high alloyed materials enables ``High Tech`` forgings to be manufactured. Based on investigations and experience gained by previously produced forgings (WYE-piece, Gate Valve components, Swivel forgings, line pipes made of Super Duplex Stainless Steels and Duplex Stainless Steels), the first X-mas trees made of solid Duplex Stainless Steel has been produced. Due to the excellent mechanical and corrosion properties of Duplex Stainless Steel, the expensive and time consuming cladding can be eliminated for most environments, which results in good economy and significantly reduced production time. To obtain information about the quality of such a large forging, samples were taken from one of these X-mas trees and the mechanical and corrosion properties were investigated.

Hochoertler, G.; Zeiler, G.; Haberfellner, K.

1995-12-31T23:59:59.000Z

15

65 6 1980 871-88:J BORIS SKET and TnoMAS M. lLlFFE  

E-Print Network [OSTI]

65 6 1980 871-88:J BORIS SKET and TnoMAS M. lLlFFE Bermuda Biological Station, and Institut za. Introduction 871 872 872 872 873 873 873 873 875 875 877 877 878 880 880 880 The Bermuda Islands consist

Iliffe, Thomas M.

16

Determination of the structural changes by Raman and {sup 13}C CP/MAS NMR spectroscopy on native corn starch with plasticizers  

SciTech Connect (OSTI)

The plasticizing - antiplasticizing effect of water and glycerol contents on native corn starch samples is investigated by FT-Raman and {sup 13}C CP/MAS NMR spectroscopy. The presence of both amorphous and crystalline structural phases was evidenced in pure native corn starch and also in the samples containing plasticizers. Among the crystalline starch structures, the A- and V- types were suggested by CP/MAS NMR spectra.

Cozar, O. [Academy of Romanian Scientists, Splaiul Independentei 54, 050094, Bucharest, Romania and National Institute of Research-Development for Machines and Installations Designed to Agriculture and Food Industry - INMA Bucure?ti - Cluj-Napoca Branch (Romania)] [Academy of Romanian Scientists, Splaiul Independentei 54, 050094, Bucharest, Romania and National Institute of Research-Development for Machines and Installations Designed to Agriculture and Food Industry - INMA Bucure?ti - Cluj-Napoca Branch (Romania); Filip, C.; Tripon, C. [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath, 400293 Cluj-Napoca (Romania)] [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath, 400293 Cluj-Napoca (Romania); Cioica, N.; Co?a, C.; Nagy, E. M. [National Institute of Research-Development for Machines and Installations Designed to Agriculture and Food Industry - INMA Bucure?ti - Cluj-Napoca Branch, RO-400458 Cluj-Napoca (Romania)] [National Institute of Research-Development for Machines and Installations Designed to Agriculture and Food Industry - INMA Bucure?ti - Cluj-Napoca Branch, RO-400458 Cluj-Napoca (Romania)

2013-11-13T23:59:59.000Z

17

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, Sbastien; Colombi, Stphane; Blaizot, Jrmy; Dubois, Yohan; Pichon, Christophe

2013-01-01T23:59:59.000Z

18

ARM - Campaign Instrument - mas  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation DesertgovInstrumentsap-surf Comments?govInstrumentsmaeri Comments? We would love to hear

19

doi:10.1016/S0016-7037(02)00026-7 The distribution of sodium ions in aluminosilicate glasses: A high-field Na-23 MAS and 3Q  

E-Print Network [OSTI]

of Geological and Environmental Sciences, Stanford University, Stanford, CA 94305-2115, USA (Received May 22-SiO2 join) and its distribution using 23 Na magic-angle spinning (MAS) nuclear magnetic resonance) because of the reduced effect of second-order quadrupolar interaction, and 23 Na MAS NMR spectra thus

Puglisi, Joseph

20

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

SciTech Connect (OSTI)

NMR and NQR at low frequencies are difficult prospects due to small nuclear spin polarization. Furthermore, the sensitivity'of the inductive pickup circuitry of standard spectrometers is reduced as the frequency is lowered. I have used a cw-SQUID (Superconducting QUantum Interference Device) spectrometer, which has no such frequency dependence, to study the local atomic environment of {sup 14}N via the quadrupolar interaction. Because {sup 14}N has spin I = 1 and a 0-6 MHz frequency range, it is not possible to obtain well-resolved spectra in high magnetic fields. I have used a technique to observe {sup 14}N NQR resonances via their effect on neighboring protons mediated by the heteronuclear dipolar interaction to study peptides and narcotics. The sensitivity of the SQUID is not enough to measure low-frequency surface (or other low spin density) systems. The application of spin-polarized xenon has been previously used to enhance polarization in conventional NMR experiments. Because xenon only polarizes spins with which it is in contact, it is surface selective. While differences in chemical shifts between surface and bulk spins are not large, it is expected that the differences in quadrupole coupling constant should be very large due to the drastic change of the electric field gradient surrounding spins at the surface. With this in mind, I have taken preliminary steps to measure SQUID detected polarization transfer from Xe to another spin species at 4.2 K and in small magnetic fields (<50 G). In this regime, the spin-lattice relaxation of xenon is dependent on the applied magnetic field. The results of our efforts to characterize the relaxation of xenon are presented. The final section describes the solid-state variable-temperature (VT) one- and two-dimensional {sup 13}C cross polarization (CP)/magic angle spinning (MAS) NMR of Hf({eta}{sup 5}-C{sub 5}H{sub 5}){sub 2}({eta}{sup 1}-C{sub 5}H{sub 5}){sub 2}, Zr({eta}{sup 5}-C{sub 5}H{sub 5}){sub 3}({eta}{sup 1}-C{sub 5}H{sub 5}) and Sn({eta}{sup 1}-C{sub 5}H{sub 5}){sub 4}. This work was undertaken in the hope of gaining insight into the intramolecuhrr dynamics, specifically which fluxional processes exist in the solid state, by what mechanism rearrangements are occurring, and the activation energies by which these processes are governed.

Ziegeweid, M.A.

1995-11-29T23:59:59.000Z

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

Journes MAS 2010, Bordeaux Session : Algorithmes Stochastiques  

E-Print Network [OSTI]

Carlo adaptatives par Jrome Lelong Adaptive Monte Carlo methods are powerful variance reduction a randomly truncated stochastic algorithm. Finally, we apply this technique to the valuation of nancial deri

Boyer, Edmond

22

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.

23

MAS.963 Ambient Intelligence, Spring 2004  

E-Print Network [OSTI]

This course focuses on Ambient Intelligence, and how it envisions a world where people are surrounded by intelligent and intuitive interfaces embedded in the everyday objects around them. These interfaces recognize and ...

Maes, Patricia

24

Magnesium Silicate Dissolution Investigated by 29Si MAS, 1H-29Si CP MAS,  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: VegetationEquipment Surfaces and InterfacesAdministration -Lowell L.FallU . S . DMagellan

25

MAS 108 Probability I Test 11 November 2005, 16101655  

E-Print Network [OSTI]

) For which values of p are they more likely to have 2 boys than 3 boys? 3 #12;4 (15 marks) A fish is caught at random on the Great Barrier Reef. The probability that the fish is striped is 7/20; the probability that the fish is luminous is 1/5; and the probability that the fish is both striped and luminuous is 1/20. Find

Bailey, R. A.

26

MAS 552.J / 4.557J MIT Living Labs  

E-Print Network [OSTI]

innovations that including new lightweight electric vehicles, electric charging and smart grid technologies) the CityHome. MoD systems consist of a fleet of Lightweight Electric Vehicles (LEVs) distributed that tackle the "First and Last Mile" problem of public transit systems. The CityCar designed by the Changing

27

Surveillance Guide - MAS 10.1 Implementation of the Integrated...  

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

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...

28

The Indiana MAS Project: Goals and Preliminary Results  

E-Print Network [OSTI]

. Martelli, M. Ancona Dipartimento di Informatica, Bioingegneria, Robotica e Ingegneria dei Sistemi (Dipartimento di Informatica, Bioingegneria, Robotica e Ingeg- neria dei Sistemi) and Salerno (Dipartimento di

Mascardi, Viviana

29

MAS.963 Special Topics: Computational Camera and Photography, Fall 2008  

E-Print Network [OSTI]

A computational camera attempts to digitally capture the essence of visual information by exploiting the synergistic combination of task-specific optics, illumination, sensors and processing. In this course we will study ...

Raskar, Ramesh

30

Scheduling on the MasPar SIMD parallel computer  

E-Print Network [OSTI]

This thesis studies the feasibility of a task scheduler for a parallel operating system. After analyzing several task scheduling algorithms, the highest level first algorithm was chosen. This algorithm has been empirically found to build schedules...

Perkins, Keith Douglas

1995-01-01T23:59:59.000Z

31

NanoMas Technologies Inc | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: Energy Resources Jump to:46 -Energieprojekte3Informationof Energy Calculator29

32

QUEEN MARY, UNIVERSITY OF LONDON MAS 314 Design of Experiments  

E-Print Network [OSTI]

in the construction of underwater structures at sea, such as piers and oil-drilling platforms. He wants to protect the engineer how best to use his resources in his experiment. 1 #12;3 (Question 3 from Assignment 4 on the output. 4 (Question 5 from Practical 8) Groups of apples were stored in a shed in a 4 ? 4 Latin square

Bailey, R. A.

33

QUEEN MARY, UNIVERSITY OF LONDON MAS 314 Design of Experiments  

E-Print Network [OSTI]

in the construction of underwater structures at sea, such as piers and oil-drilling platforms. He wants to protect the engineer how best to use his resources in his experiment. 2 Look at the Genstat output for Question 7 of Practical 3. Explain what Genstat is doing when the Treatment Structure is control/tmt. What hypothesis

Bailey, R. A.

34

DOI: 10.1002/adsc.201000585 Synthesis, Immobilization, MAS and HR-MAS NMR of a New  

E-Print Network [OSTI]

on silica with their phosphonium moieties via electro- static interactions, and their mobility and leaching- vents. Immobilized Wilkinson-type rhodium com- plexes have been obtained by ligand exchange nanoparticles Introduction Catalysts immobilized on solid supports are of grow- ing academic and industrial

Bluemel, Janet

35

E-Print Network 3.0 - airborne multispectral mas Sample Search...  

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

Lieff Airborne Research Australia, Flinders University Glen Scholz Source: Walker, Jeff - Department of Civil and Environmental Engineering, University of Melbourne...

36

The refocused INADEQUATE MAS NMR experiment in multiple spin-systems: Interpreting observed correlation  

E-Print Network [OSTI]

de Chimie (UMR 5182 CNRS/ENS Lyon), E´ cole Normale Supe´rieure de Lyon, 46 alle´e d'Italie, 69364

Baltisberger, Jay H.

37

MAS.622 / 1.126J Pattern Recognition & Analysis, Fall 2000  

E-Print Network [OSTI]

Fundamentals of characterizing and recognizing patterns and features of interest in numerical data. Basic tools and theory for signal understanding problems with applications to user modeling, affect recognition, speech ...

Massachusetts Institute of Technology. Media Laboratory.

38

Surveillance Guide - MAS 10.2 Control of Measuring and Test Equipment  

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

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,...

39

E-Print Network 3.0 - aquilo mas eu Sample Search Results  

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

de mathmatiques Collection: Mathematics 57 Em 1962, num galpo de madeira, o professor Oscar desenhava a UnB de seus sonhos. tinha praa, museu e auditrio. Veio a ditadura, levou...

40

E-Print Network 3.0 - angle spinning hr-mas Sample Search Results  

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

and Ecology 72 Origin and Control of Spin Currents in a Magnetic Triplet Josephson Junction Philip M. R. BRYDON Summary: Origin and Control of Spin Currents in a Magnetic...

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

Gii thiu v trng UMass Amherst l trng ni ting trong h thng i Hc Mas-  

E-Print Network [OSTI]

khoa hc k thut polime c xp hng trong cc ngnh hc hng u ton quc trong s cc trng i hc cng lp hay i

Mountziaris, T. J.

42

A mi familia, que son lo que mas quiero en el mundo Agradecimientos  

E-Print Network [OSTI]

´itmica . . . . . . . . . . . . . . . . . . . . . 10 1.4 Programaci´on lineal y teor´ia poliedral . . . . . . . . . . . . . 13 1.5 Clases de matrices

Bonomo, Flavia

43

E-Print Network 3.0 - auxiliary sources mas Sample Search Results  

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

Florida State University Collection: Engineering 13 School Of Mathematics & Statistics Dual Honours Degrees Summary: , but the material must always be attributed to its sources...

44

Looking for an Exit: Variations on M&As and IPOs Moderator: Timothy J. Keating  

E-Print Network [OSTI]

Public Offerings 3 · Partner, Investment Banking · Head of Greentech/Alternative Energy Investment, University of Illinois, 1987 · MBA, J.L. Kellogg School of Management, Northwestern University, 1992 Shez Compliance Requirements (Sarbanes-Oxley, Audit, Governance) # of Responses Answered as a Top 3 Issue

45

MAS276 Rings and Groups Feedback on exam 2010-11  

E-Print Network [OSTI]

+ instead of -. Many people did not point out that the norm test is again completely conclusive, ie, and then checked each condition. iii) Most people had the right idea but many people then got confused about the ring is not a UFD". iv) Far too many people said yes, with spurious "reasons" such as "it's a subring

Cheng, Eugenia

46

Memoria 2011 Biblioteca y Archivo Universidad Autnoma de Madrid Cartoteca "Rafael Mas"  

E-Print Network [OSTI]

pormenorizados en el Inventario de los Materiales Cartográficos ­ 2011, disponible en la web: (http://biblioteca.uam.es/cartoteca/documentos/inventario

Autonoma de Madrid, Universidad

47

QUALIT DES ENSILAGES DE MAS GRAIN HUMIDE PRSERVS PAR L'ACIDE PROPIONIQUE  

E-Print Network [OSTI]

product) and acetic (0,1-0,3 per cent) acids are produced by carbohydrate fermentation. The silage p mas grain humide, la fermentation des glucides entrane une pro- duction notable d'acides lactique (0 degradative change is practically inhi- bited after 3 to 8 months : in our assays, lactic and acetic acids

Paris-Sud XI, Universit de

48

6.868J / MAS.731J The Society of Mind, Spring 2007  

E-Print Network [OSTI]

This course is an introduction to a theory that tries to explain how minds are made from collections of simpler processes. The subject treats such aspects of thinking as vision, language, learning, reasoning, memory, ...

Minsky, Marvin

49

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

50

Following Solid-Acid-Catalyzed Reactions by MAS NMR Spectroscopy in Liquid  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsing ZirconiaPolicyFeasibilityFieldMinds" |beamthe Light Just like

51

In situ solid state B-11 MAS-NMR studies of the thermal decomposition of  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFun withconfinementEtching.348 270 300Aptamers andIn otherToF-SIMS. |

52

High field DNP and cryogenic MAS NMR : novel instrumentation and applications  

E-Print Network [OSTI]

Solid State Nuclear Magnetic Resonance (ssNMR) spectroscopy has blossomed over the last two decades. As ssNMR is progressively applied to more challenging systems, the sensitivity remains one of its major limiting factors. ...

Markhasin, Evgeny

2014-01-01T23:59:59.000Z

53

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

E-Print Network [OSTI]

a,1 a J. Heyrovsky Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, CZ hydrocarbon mixtures rich in the gasoline fraction (MTG) or low chain olefins (MTO) [3,4]. As feedstock than gasoline, there is a growing interest for conversion of methanol to C2 and C3 olefins. However

Sklenak, Stepan

54

Valen Mas Que Mil Palabras: Las Etiquetas de Advertencia Pictoricas de Tabaco y Los Derechos Linguisticos de EEUU  

E-Print Network [OSTI]

4 Los idiomas y la alfabetizacin eningls o con niveles de alfabetizacin limi- tada. Laslings- ticos y de alfabetizacin. El hecho de que estas

Jaron Browne; Susana Hennessey-Lavery; Kim Rogers

2007-01-01T23:59:59.000Z

55

Application of REDOR subtraction for filtered MAS observation of labeled backbone carbons of membrane-bound fusion peptides  

E-Print Network [OSTI]

in membrane-bound fusion peptides. In many biopolymeric systems in the solid state, it is important to filter

Weliky, David

56

With more than 90% of all stars sharing fates similar to that of the Sun, more mas-  

E-Print Network [OSTI]

al. monitored the -Cephei star HD 129929 (with a mass of 9.5 solar mass- es) for more than 21 years of convection in its central nuclear furnace drives mixing of material beyond the "classi- cal" limits cooling track--the last part of this evolution for stars of less than ~8 solar masses (M

Melbourne, Timothy

57

A comparison of cloud top heights computed from airborne lidar and MAS radiance data using CO2 slicing  

E-Print Network [OSTI]

budgets. Their impact on the radiation budget can result in a heating or in a cooling of the planet al., 1989; Wylie and Menzel, 1989], determine diabatic heating profiles and hence affect the general to global climate change studies. One important passive remote sensing method of obtaining the altitude

Sheridan, Jennifer

58

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

Broader source: Energy.gov [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...

59

MAS 552 / 4.557 Innovation Hubs, Integrating Technology + Design [QUITO LAB] MIT Spring 2014, 1:30 -4:30 pm  

E-Print Network [OSTI]

, students are challenged to focus on diverse fields for their proposals, such as social innovation, city/analysis/data collection/project design 3) Project development + Social Revolution: project development/social innovation-Deliktum / Social innovation MARCH 12 *Robin Chase / Zipcar founder / Social Entrepreneurship MARCH 19 *Nicco Mele

60

MAS NMR Study of the Metastable Solid Solutions Found in the LiFePO4/FePO4 System  

E-Print Network [OSTI]

compared to the lithium-electron interaction in x Li FeP04 (by Fermi contact interactions between the lithium ions andlithium ions in LiFePC^ suggests a modification of the Fe -O-P interaction.

Cabana, Jordi

2010-01-01T23:59:59.000Z

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

MAS NMR Study of the Metastable Solid Solutions Found in the LiFePO4/FePO4 System  

E-Print Network [OSTI]

Introduction Lithium-ion batteries have played a centralas current commercial Li-ion batteries currently do not meetnext generation of batteries designed for transportation '

Cabana, Jordi

2010-01-01T23:59:59.000Z

62

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.

63

Department of Mathematics & Statistics Tutor List FILE: Tutor List_MathHelp Centre/Tutor List_July 10, 2013 Last updated July 10, 2013_mas905  

E-Print Network [OSTI]

. Kevin Krieger kjk193@mail.usask.ca Math 110/116/123 & 124 Khalid Amin kba561@mail.usask.ca / 2624489

Saskatchewan, University of

64

Mujer Mas Segura (Safer Women): A combination prevention intervention to reduce sexual and injection risks among female sex workers who inject drugs  

E-Print Network [OSTI]

paraphernalia (i.e. , cookers, cotton, rinse water) at leasti.e. , cotton filter, cookers, rinse water) that had beenparaphernalia (i.e. , cotton, cooker, rinse-water), city of

2012-01-01T23:59:59.000Z

65

E-Print Network 3.0 - aerobic kinetic resolution Sample Search...  

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

(MAS, maximal aerobic speed). Temperature affected the kinematics... consumption; MAS maximum aerobic speed; C i, minimum cost of locomotion; te,,endurance time * To whom... -...

66

"La Matemtica permite ver tramas  

E-Print Network [OSTI]

produ- cir generadores de demostraciones de teore- mas sino indagar sobre la creatividad incons- ciente

Díaz, Jesús Ildefonso

67

Evaluating demographic models for goat domestication using mtdna sequences  

E-Print Network [OSTI]

(UGI) University College London, Gower Street, London WC1E 6BT (United Kingdom) Mark G. thoMas Research

68

A Changing Planet Over the past century, the average global tempera-  

E-Print Network [OSTI]

tons of hydrogen fuse into helium within the sun's core as part of a mas- sive chain of thermonuclear

69

Estimados de diversidad de rboles del Bosque Seco de  

E-Print Network [OSTI]

elementos por conocer? ¿Dónde es mas probable encontrarlos? #12;Técnicas tradicionales · Inventario de

Gilbes, Fernando

70

The European Extremely Large TelescopeThe European Extremely Large Telescope Project OverviewProject Overview  

E-Print Network [OSTI]

area: 382 m2 655 m2 978 m2 Diff. limit at 1µm: 9.9 mas 8.4 mas 6.4 mas #12; Current rings of segments: Largest fully enclosed D Circumscribing D Area Segments. Six laser guide stars (provisions for eight), launched from the side. Nearly 3000 tonnes of moving

Liske, Jochen

71

Mapa GlobCover 2009. European Space Agency (ESA). www.esa.int Ciudad Universitaria de Cantoblanco 28049 Madrid  

E-Print Network [OSTI]

.uam.es/cartoteca/default.html Cartoteca "Rafael Mas" INVENTARIO DE LOS MATERIALES CARTOGRÁFICOS 2010 #12;UAM. Cartoteca "Rafael Mas". Inventario, 2010 2 La CARTOTECA RAFAEL MAS es una biblioteca especializada en cuanto a las características". Inventario, 2010 3 El Boletín Meteorológico Diario, editado por el Instituto Nacional de Meteorología, fue

Autonoma de Madrid, Universidad

72

E-Print Network 3.0 - acontecimientos adversos por Sample Search...  

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

de Extensin Cooperativa Facultad de Agricultura y Economa Domstica Para encontrar mas recursos para negocios, el hogar la familia, visite la Facultad de Agricultura y Economa...

73

Does the Effect of Pollution on Infant Mortality Differ Between Developing and Developed Countries? Evidence from Mexico City  

E-Print Network [OSTI]

could affect both pollution levels and infant mortality. Therelationship between pollution (! !" ) in a municipality (m)as very suggestive. pollution may be richer, and thus have

Arceo, Eva; Hanna, Rema; Oliva, Paulina

2012-01-01T23:59:59.000Z

74

Narrative and (Meta)Physical Paradox in "Grande Sertao: Veredas" and "Pedro Paramo"  

E-Print Network [OSTI]

respostas j conhece de antemo. Vim como combinamos porquecontei, remexer vivo o que vim dizendo. Porque no narreipreso. Diadorim e eu viemos, vim; de rota abatida. Mas,

Schneider, Caroline LeFeber

2011-01-01T23:59:59.000Z

75

AS TEORIAS RIVAIS SOBRE A PROPRIEDADE INTELECTUAL NO BRASIL  

E-Print Network [OSTI]

ao comrcio. Mas o governo central no queria perder onacional. Entretanto, o governo coreano investiu nossocialista fez com que o governo russo emitisse uma pliade

Timm, Luciano Benetti; Caovilla, Renato

2009-01-01T23:59:59.000Z

76

A study of the image formation model and noise characterization in SPECT imaging.  

E-Print Network [OSTI]

proporcional al flujo sanguineo cerebral local al momento de su administracion. La tecnica mas utilizada

77

Ocrebrouma mquinadeTuring  

E-Print Network [OSTI]

da má quina a imitar Tudo isto poderá parecer despro vido de interesse prático mas nada está mais

Menczer, Filippo

78

E-Print Network 3.0 - army surgical hospital Sample Search Results  

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

Surgeon. Trained by Summary: ). Ran military hospital at Renkioi, influenced by Nightingale. Became Chair of Hygiene at Army Medical... , St Thomas's Hospital, Examiner, Mas-...

79

E-Print Network 3.0 - advanced maternity skills Sample Search...  

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

in the MAS, comments that "there is a growing need for skilled maternal and child health professionals... ANNOUNCEMENT PUBLICATION OR WEB SITE POSTING Publication Editor...

80

E-Print Network 3.0 - atmosfericas um estudo Sample Search Results  

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

mais eficaz de estudo, mas ocasionalmente esta Source: Instituto de Sistemas e Robotica - Polo de Lisboa (Institute for Systems and Robotics, Lisbon pole) Portugal...

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

E-Print Network 3.0 - auto-imune um estudo Sample Search Results  

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

mais eficaz de estudo, mas ocasionalmente esta Source: Instituto de Sistemas e Robotica - Polo de Lisboa (Institute for Systems and Robotics, Lisbon pole) Portugal...

82

E-Print Network 3.0 - aquecidos um estudo Sample Search Results  

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

mais eficaz de estudo, mas ocasionalmente esta Source: Instituto de Sistemas e Robotica - Polo de Lisboa (Institute for Systems and Robotics, Lisbon pole) Portugal...

83

E-Print Network 3.0 - ah-3 type iii Sample Search Results  

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

50 18. a) Ventanas temporales mas utilizadas... locutor para 'Ah3R1 - SVM con es- tad Source: Autonoma de Madrid, Universidad - Escuela Politcnica Superior, Biometric...

84

ARM - Employment Opportunities Article  

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

Two Faculty Positions in Extreme Weather and Regional Climate Change - Stony Brook University Bookmark and Share The School of Marine and Atmospheric Sciences (SoMAS) at Stony...

85

The City Effect: Urban Institutions, Peripheries and Political Participations in Bolivia  

E-Print Network [OSTI]

Judiciary Institute of Bolivia. Albro, Robert. 2005. TheAlem, Robert. 2007. Nunca Mas [documentary]. Bolivia: BandaBrava Bolivia/Buena Onda Films. Alexander, Robert. 2005. A

Cielo, Maria Cristina Malong

2010-01-01T23:59:59.000Z

86

The University of Texas at Austin -College of Liberal Arts Ethnic Studies (Mexican American Studies) Degree Plan  

E-Print Network [OSTI]

/Bicultural* _________ *ANY upper-division Spanish course may be substituted for MAS 350 3 hours chosen from MAS 361 Cultural Minor: This major does not require a minor Minor Electives: A maximum of 16 hours may be taken on a pass

Texas at Austin, University of

87

Conceptual configurations of an accelerator-driven subcritical system utilizing minor actinides  

SciTech Connect (OSTI)

This paper purposes an Accelerator-Driven Subcritical (ADS) system which utilizes the Minor Actinides (MAs) from the US spent nuclear fuel inventory. A mobile fuel concept with micro-particles suspended in the liquid metal is adopted in the purposed system to avoid difficulties of developing and testing new MAs solid fuel forms. Three ADS configurations were developed and analyzed using the Monte Carlo fuel burnup methodology. The analyses demonstrated the capabilities of the proposed system to utilize the MAs and to dispose of the US spent nuclear fuels. (authors)

Cao, Y.; Gohar, Y. [Nuclear Engineering Div., Argonne National Laboratory, 9700 South Cass Ave., IL 60439 (United States)

2012-07-01T23:59:59.000Z

88

BWR Assembly Optimization for Minor Actinide Recycling  

SciTech Connect (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

89

Characterization of Cu-ZSM-5 Prepared by Solid-State Ion Exchange of H-ZSM-5 with CuCl  

E-Print Network [OSTI]

Cl occlusion in the zeolite pores. After SSIE, the resulting Cu-ZSM-5 was characterized by XRD, 27 Al MAS NMR and nitriles,15 the desulfurization of diesel fuel,16 and the oxidative carbony- lation of methanol to dimethyl

Bell, Alexis T.

90

Pblico Online Pas: Portugal  

E-Print Network [OSTI]

Publicação. O seu IP não será divulgado, mas ficará registado na nossa base de dados. Quaisquer comentários

Instituto de Sistemas e Robotica

91

Evolving Protocols and Agents in Multiagent Systems Scott N. Gerard  

E-Print Network [OSTI]

Evolving Protocols and Agents in Multiagent Systems Scott N. Gerard Department of Computer Science (AA- MAS 2013), Ito, Jonker, Gini, and Shehory (eds.), May, 6­10, 2013, Saint Paul, Minnesota, USA

92

agent system based: Topics by E-print Network  

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

MAS and various approaches, like Web services, Ontology, and Data mining techniques, in e-Business that want to improve responsiveness and efficiency of systems so as to extract...

93

[superscript 15]N-[superscript 15]N Proton Assisted Recoupling in Magic Angle Spinning NMR  

E-Print Network [OSTI]

We describe a new magic angle spinning (MAS) NMR experiment for obtaining [superscript 15]N?[superscript 15]N correlation spectra. The approach yields direct information about the secondary and tertiary structure of proteins, ...

Lewandowski, Jozef R.

94

Lipid Dynamics and ProteinLipid 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

95

Dynamic Nuclear Polarization Study of Inhibitor Binding to the M2[subscript 1860] Proton Transporter from Influenza A  

E-Print Network [OSTI]

We demonstrate the use of dynamic nuclear polarization (DNP) to elucidate ligand binding to a membrane protein using dipolar recoupling magic angle spinning (MAS) NMR. In particular, we detect drug binding in the proton ...

Andreas, Loren B.

96

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 ?N NMR in combination ... Chapter 2. Carbene chemistry in the ...

Sceats, Emma Louise, 1978-

2004-01-01T23:59:59.000Z

97

attribute decision making: Topics by E-print Network  

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

6, UPM Decision Making in MAS, March 2007 2344 12;About this lecture This course Zachmann, Gabriel 5 How brains make decisions Quantum Physics (arXiv) Summary: This chapter,...

98

action-based decision making: Topics by E-print Network  

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

6, UPM Decision Making in MAS, March 2007 2344 12;About this lecture This course Zachmann, Gabriel 3 How brains make decisions Quantum Physics (arXiv) Summary: This chapter,...

99

applied decision making: Topics by E-print Network  

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

6, UPM Decision Making in MAS, March 2007 2344 12;About this lecture This course Zachmann, Gabriel 7 How brains make decisions Quantum Physics (arXiv) Summary: This chapter,...

100

For only the second time, a scientist at Brigham Young University has won the  

E-Print Network [OSTI]

, a faculty member in the Statistics Department, tackled some mas- sive amounts of sales tax data to deter rates. By looking over the past fifteen years of tax records for ev- What would you be willing to do

Seamons, Kent E.

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

Um cientista universitrio  

E-Print Network [OSTI]

a honra de ser seu amigo. Sei como lutou por um país que não fosse só mais desenvol- vido, mas também mais

Instituto de Sistemas e Robotica

102

Proceedings of the 52nd Annual Meeting of the Association for Computational Linguistics, pages 871880, Baltimore, Maryland, USA, June 23-25 2014. c 2014 Association for Computational Linguistics  

E-Print Network [OSTI]

Proceedings of the 52nd Annual Meeting of the Association for Computational Linguistics, pages 871 a massive aanval op their employ- 871 #12;ment and social rights." Desired output: "Workers are facing a mas

103

Optimization of actinide transmutation in innovative lead-cooled fast reactors  

E-Print Network [OSTI]

The thesis investigates the potential of fertile free fast lead-cooled modular reactors as efficient incinerators of plutonium and minor actinides (MAs) for application to dedicated fuel cycles for transmutation. A methodology ...

Romano, Antonino, 1972-

2003-01-01T23:59:59.000Z

104

Kinetics of Yttrium-Ligand Complexation Monitored Using Hyperpolarized 89 as a Model for Gadolinium in Contrast Agents  

E-Print Network [OSTI]

(a model for uranium and other actinide storage materials) by 89 Y magic-angle spinning (MAS) NMR.8 The radioisotope 90 Y can be used for cancer therapy.9 Golman et al.10 demonstrated that the metabolic conversion

105

Foundations on Sand: An Analysis of the First U.S. Occupation of Haiti, 1915-1934  

E-Print Network [OSTI]

of Haitian Studies Occasional Papers Bryant C. Freeman, Ph.D. - Series Editor N 1 - Konstitisvon Repiblik Ayiti, 29 mas 1987. 1994. Pp. vi-106. Haitian-language version (official orthography) of the present Constitution, as translated by Paul Dejean...

Bunce, Peter L.

2003-01-01T23:59:59.000Z

106

E-Print Network 3.0 - applied algebra algebraic Sample Search...  

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

MAS 6396, Section 2, 12:00-12:50 MWF, SE 215... Constructive algebra goes back to the work of Kronecker and Brouwer. It is traditional abstract ... Source: Richman, Fred -...

107

NMR Studies of Heat-Induced Transitions in Structure and Cation...  

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

in Structure and Cation Binding Environments of a Strontium-Saturated Swelling Mica. Abstract: In this work we combined Al, Si, F, and Na magic-angle spinning (MAS) nuclear...

108

APPLICATION OF MACHINE LEARNING FOR MACHINE MONITORING AND DIAGNOSIS  

E-Print Network [OSTI]

­ lish pump condition at the Montreal Shell Refinery and were based on frequency characteristics­ ing related damages were tagged and the correspond­ ing historical measurements were selected. ``Mas

Maluf, David A.

109

E-Print Network 3.0 - a-bomb survivors Sample Search Results  

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

survivors. The reason that the A-bomb... depicts lifetime cancer risks from a given low dose of radiation, based on results from A-bomb survivors... .15 200 mAs different organs...

110

Corrado Mascia Sapienza, Universit di Roma  

E-Print Network [OSTI]

), Parigi (Francia). professore visitatore maggio 2014 ?cole Centrale de Paris, Laboratoire MAS (Mathematics Applied to Systems), Parigi (Francia). professore visitatore Attività scientifica Interessi di ricerca

Mascia, Corrado

111

Characterization of cation environments in polycrystalline forsterite...  

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

forsterite by Mg-25 MAS, MQMAS, and QCPMG NMR . Abstract: Forsterite (Mg2SiO4) is a silicate mineral frequently studied in the Earth sciences as it has a simple crystal structure...

112

Automatic Microaneurysm Detection and Characterization Through Digital Color Fundus Images  

SciTech Connect (OSTI)

Ocular fundus images can provide information about retinal, ophthalmic, and even systemic diseases such as diabetes. Microaneurysms (MAs) are the earliest sign of Diabetic Retinopathy, a frequently observed complication in both type 1 and type 2 diabetes. Robust detection of MAs in digital color fundus images is critical in the development of automated screening systems for this kind of disease. Automatic grading of these images is being considered by health boards so that the human grading task is reduced. In this paper we describe segmentation and the feature extraction methods for candidate MAs detection.We show that the candidate MAs detected with the methodology have been successfully classified by a MLP neural network (correct classification of 84percent).

Martins, Charles; Veras, Rodrigo; Ramalho, Geraldo; Medeiros, Fatima; Ushizima, Daniela

2008-08-29T23:59:59.000Z

113

Computing a Cournot Equilibrium in Integers  

E-Print Network [OSTI]

Page 1 ... variants of these, form a standard topic in oligopoly theory: see, for ex- ample Mas-Colell, Whinston, and Green [4], pp. 389394, or Varian [11], pp.

2014-05-13T23:59:59.000Z

114

Antnio Nvoa Consultor da UNESCO  

E-Print Network [OSTI]

. Essa energia está muito presente no Brasil. > E falta em Portugal? Falta, e muito. Parecemos título de reitor honorário da Universidade de Lisboa. Mas depois regressa ao Brasil, onde planeia ficar a Universidade de Lisboa, mas deixou a reito- ria a António Cruz Serra e mudou-se para o Brasil, onde é consultor

Instituto de Sistemas e Robotica

115

MAC 0316/5754 --Conceitos de Linguagens de Programac~ao Primeiro Semestre de 2010  

E-Print Network [OSTI]

interpretador FWAE/D, mas produza um resultado num´erico diferente em cada uma dessas linguagens. (b) D^e um, mas rode sem problemas e produza um resultado num´erico quando executado por um interpretador FWAE/D. (c) D^e um exemplo de programa que rode sem problemas e produza um resultado num´erico quando execu

Reverbel, Francisco

116

INTEGRATED CONTROL OF NEXT GENERATION POWER SYSTEM  

SciTech Connect (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 â??â?¦a loosely-coupled network of problem solvers that work together to solve problems that are beyond their individual capabilitiesâ?¦â?. 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

117

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

SciTech Connect (OSTI)

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

118

The grotesque in Don Quijote de la Mancha by Miguel de Cervantes Saavedra and The Tyrant by Ramon Del Valle-Inclan  

E-Print Network [OSTI]

lo sublime. Cree que la literatura americana lo contiene mAs. De los personajes 11 que estudia, tienen una multitud de calidades complejas y contradictorias. O' Connor afirma que los personajes mezclados crean un mundo extrano que molesta nuestro... calidades ridiculas. Cree que lo grotesco viene de una region de la mente demoniaca. A el no le importa si los demonios vienen de lo mas a115 o dentro de nuestras mentes porque para el es lo mismo (Barasch xiii-xv). Segun Jennings, hay un efecto triple...

Peterson, Valerie Hoppe

1994-01-01T23:59:59.000Z

119

Studies of a New Fusarium Wilt of Spinach in Texas.  

E-Print Network [OSTI]

melted but properly cooled agar, and crushed with sterile forceps. The agar containing the crushed tissue was poured from the tube into a sterile Petri dish. In order to keep out contamination from bacteria, a drop of a 5 per cent lactic acid mas added... to each Petri dish. As soon as growth appeared transfers were made to slants of agar tubes and the resulting pure growth mas used for inoculation or study. It is seen in Table 1 that the causal organism was recovered from the roots only of affected...

Taubenhaus, J. J. (Jacob Joseph)

1926-01-01T23:59:59.000Z

120

Proper Motion of Pulsar B1800-21  

E-Print Network [OSTI]

We report high angular resolution, multi-epoch radio observations of the young pulsar PSR B1800-21. Using two pairs of data sets, each pair spanning approximately a ten year period, we calculate the proper motion of the pulsar. We obtain a proper motion of mu_alpha=11.6 +- 1.8 mas/yr, mu_delta=14.8 +- 2.3 mas/yr, which clearly indicates a birth position at the extreme edge of the W30 supernova remnant. Although this does not definitively rule out an association of W30 and PSR B1800-21, it does not support an association.

W. F. Brisken; M. Carrillo-Barragan; S. Kurtz; J. P. Finley

2006-10-20T23:59:59.000Z

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.


121

BIO: Milton H. Marquis Professor of Economics  

E-Print Network [OSTI]

BIO: Milton H. Marquis Professor of Economics Bellamy Building Department of Economics Florida received a Mas- ter of Arts degree in Economics in 1982 and a Ph.D. in Economics in 1985 from Indiana University. He has taught economics and finance at St. Olaf College in Northfield, MN and at Florida State

Bowers, Philip L.

122

SecuestrodeCO2enestructurasgeolgicas Modelacin numrica de  

E-Print Network [OSTI]

Kioto Responsables del 55% de las emisiones se comprometen reducir en 5% el total de emisiones respecto forma diferente A España le corresponde no aumentar en mas de 15% sus emisiones respecto a 1990 En 2006enestructurasgeológicas Una forma de disminuir emisiones: Almacenamiento de CO2 en estructuras geológicas Yacimientos de

Politècnica de Catalunya, Universitat

123

A Solid-State NMR Study of Tungsten Methyl Group Dynamics in [W(5-C5Me5)Me4][PF6  

E-Print Network [OSTI]

A Solid-State NMR Study of Tungsten Methyl Group Dynamics in [W(5-C5Me5)Me4][PF6] Douglas C. Maus Spinning (MAS) 13C and static 2H NMR studies of the dynamics of the methyl groups coordinated to tungsten

Griffin, Robert G.

124

866 IEEE TRANSACTIONS ON MAGNETICS, VOL. 44, NO. 6, JUNE 2008 Dynamical Models for Eddy Current in Ferromagnetic Cores Introduced in  

E-Print Network [OSTI]

is composed of a magnet, a mas- sive circuit, a mobile vane linked to a spring, and a coil. Fig. 1 shows a current appears in the coil, the force created by the spring becomes inferior to the one created by the magnet and the coil; thus, the relay trips. A. Modeling of the Device Thanks to 3-D nonlinear FE model

Boyer, Edmond

125

Notes for Presentations on Electricity for 3rd Grade The kits provided by the state for electricity do not, at all, explain anything about the  

E-Print Network [OSTI]

does wall­plug electricity come from? Use coil moving in magnet and hand­cranked generators (pass' styrofoam popcorn, styrofoam footstool; hand­cranked electric generators; mas­ sive coil­in­magnet generatorNotes for Presentations on Electricity for 3rd Grade Ray Frey The kits provided by the state

Frey, Raymond E.

126

Comput Math Organiz Theor (2006) 12:181204 DOI 10.1007/s10588-006-9543-9  

E-Print Network [OSTI]

improve the robustness (i.e., stability, reliability, or scalability) of open multiagent systems (MAS types helps to balance the trade-off between the autonomy of self-interested agents and the maintenance ( ) Department of Deduction and Multiagent Systems, German Research Center for Artificial Intelligence (DFKI

López-Sánchez, Maite

127

Haseltonia 14: 161169. 2008 161 1. Introduction  

E-Print Network [OSTI]

species occur in cen- Abstract: The most recent treatments of the family Cactaceae for Uruguay floccosa are new records for the flora of Uruguay. The occurrence of Epiphyllum phyllanthus in Uruguay could not be confirmed. Resumen: Los tratamientos mas recientes de la familia Cactaceae para Uruguay son

Zürich, Universität

128

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

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

(D&R) of out-of-service steam lines from K-Area to L-Area and C-Area to the X-mas tree on Burma Road. All insulating cover, steam lines, support attachments, and wooden pole...

129

SPINEVOLUTION: A powerful tool for the simulation of solid and liquid state NMR experiments  

E-Print Network [OSTI]

SPINEVOLUTION: A powerful tool for the simulation of solid and liquid state NMR experiments Mikhail. Simulations of solid-state magic angle spinning (MAS) experiments can be particularly demanding both with complex pulse sequences and multi-spin systems in solids, SPINEVO- LUTION is a versatile and easy to use

Griffin, Robert G.

130

High-resolution solid-state NMR of anisotropically mobile molecules under very low-power 1  

E-Print Network [OSTI]

High-resolution solid-state NMR of anisotropically mobile molecules under very low-power 1 H Revised 13 May 2009 Available online 21 May 2009 Keywords: Low-power decoupling Lipid membranes Solid such as WALTZ-16. We demonstrate this moderate MAS low-power decoupling technique on hydrated POPC lipid

Hong, Mei

131

SPINEVOLUTION: A powerful tool for the simulation of solid and liquid state NMR experiments  

E-Print Network [OSTI]

SPINEVOLUTION: A powerful tool for the simulation of solid and liquid state NMR experiments Mikhail and dynamic information from the spectra. Simulations of solid-state magic angle spinning (MAS) experiments for the simulation of experiments with complex pulse sequences and multi-spin systems in solids, SPINEVO- LUTION

Griffin, Robert G.

132

Spectro-interferometry of the Be star delta Sco: Near-Infrared Continuum and Gas Emission Region Sizes in 2007  

E-Print Network [OSTI]

We present near-infrared H and K-band spectro-interferometric observations of the gaseous disk around the primary Be star in the delta Sco binary system, obtained in 2007 (between periastron passages in 2000 and 2011). Observations using the CHARA/MIRC instrument at H-band resolve an elongated disk with a Gaussian FWHM 1.18 x 0.91 mas. Using the Keck Interferometer, the source of the K-band continuum emission is only marginally spatially resolved, and consequently we estimate a relatively uncertain K-band continuum disk FWHM of 0.7 +/- 0.3 mas. Line emission on the other hand, He1 (2.0583 micron) and Br gamma (2.1657 micron), is clearly detected, with about 10% lower visibilities than those of the continuum. When taking into account the continuum/line flux ratio this translates into much larger sizes for the line emission regions: 2.2 +/- 0.4 mas and 1.9 +/- 0.3 mas for He1 and Br gamma respectively. Our KI data also reveal a relatively flat spectral differential phase response, ruling out significant off-cen...

Millan-Gabet, R; Touhami, Y; Gies, D; Hesselbach, E; Pedretti, E; Thureau, N; Zhao, M; Brummelaar, T ten

2010-01-01T23:59:59.000Z

133

BOSTONIA Summer 2013 In The Jetsons, the helper robot of  

E-Print Network [OSTI]

on the energy equivalent of a Christmas-tree bulb, can explore TheRobotasDecider TEACHING ARTIFICIAL BRAINS HOW. To do it, he's made use of a breakthrough electrical component designed by Hewlett-Packard, called and synapses, saving a mas- sive amount of energy while allowing the stor- age and processing of information

Spence, Harlan Ernest

134

ARTIGO INTERNET Europa est a desenvolver biblioteca digital de matemtica 24.02.2010 -  

E-Print Network [OSTI]

chama meta-dados) é armazenada em bases de dados ­ mas as várias instituições usam software e modelos de base de dados diferentes, o que cria mais uma dificuldade na criação de um único motor de pesquisa. E

Instituto de Sistemas e Robotica

135

In K. Tuyls, et al, editors, LAMAS 2005, Lecture Notes In Artificial Intelligence, Springer Verlag, Berlin, 2006.  

E-Print Network [OSTI]

the possibility of autonomous interactions among multiple vehicles. Multiagent Systems (MAS) is the subfield of AI $63 billion (in 2002 US dollars). Each year, Americans burn approximately 5.6 billion gallons of fuel while idling in heavy traffic. Recent advances in artificial intelligence suggest that autonomous

Stone, Peter

136

Lick Northern Proper Motion Program. III. Lick NPM2 Catalog  

E-Print Network [OSTI]

The Lick Northern Proper Motion (NPM) program, a two-epoch (1947-1988) photographic survey of the northern two-thirds of the sky (Dec. > -23 deg), has measured absolute proper motions, on an inertial system defined by distant galaxies, for 380,000 stars from 8 14) anonymous stars for astrometry and galactic studies, 92,000 bright (B NPM2 proper motions are on the ICRS system, via Tycho-2 stars, to an accuracy of 0.5 mas/yr in each field. RMS proper motion precision is 6 mas/yr. Positional errors average 80 mas at the mean plate epoch 1968, and 200 mas at the NPM2 catalog epoch 2000. NPM2 photographic photometry errors average 0.18 mag in B, and 0.20 mag in B-V. The NPM2 Catalog and the updated (to J2000) NPM1 Catalog are available at the CDS Strasbourg data center and on the NPM WWW site (http://www.ucolick.org/~npm). The NPM2 Catalog completes the Lick Northern Proper Motion program after a half-century of w...

Hanson, R B; Jones, B F; Monet, D G; Hanson, Robert B.; Klemola, Arnold R.; Jones, Burton F.; Monet, David G.

2004-01-01T23:59:59.000Z

137

Crato garante para "breve devoluo  

E-Print Network [OSTI]

mem- bros do Governo que forem necessrios para as matrias em causa". Ou seja, com os secretrios de Governo, Nuno Crato limitou-se a res- ponder: "Esperemos que cor- ra bem" para se fazerem "os ajustes s programa, para 2014 a 2020, foi anunciado no incio de dezembro mas ontem o Governo assinalou o seu ar

Instituto de Sistemas e Robotica

138

Universidades aguardam por reforo no Ketificativo  

E-Print Network [OSTI]

Universidades aguardam por reforo no Ketificativo Governo vai devolver menos 12 milhes dos contas Alexandra Incio alexandra.inacio@jn.pt O Governo est a adiar, mas as universidades tm pressa na que tero de- corrente da deciso do TC". Jos Ferreira Gomes ter su- blinhado que o Governo j

Instituto de Sistemas e Robotica

139

"O financiamento da Cincia pretende garantir o  

E-Print Network [OSTI]

"O financiamento da Cincia pretende garantir o crescimento em qualidade" Cortes 0 Governo .proenca@economico.pt #12;O Governo tem sido atacado pelos cortes no financiamento da Cincia. Leonor Parreira desmente e dos investiga- dores e bolseiros fala em cortes de 50%. O Governo quer pro- mover a qualidade, mas os

Instituto de Sistemas e Robotica

140

Tiragem: 35060 Pas: Portugal  

E-Print Network [OSTI]

investimento directo do Estado no ensino superior vai voltar a descer no prximo ano. O Governo prepara-se para procura de novas receitas prprias e de si- multneo aumento da qualidade". O Governo sublinha tambm que que seria devido. O Governo reconheceu o erro, mas s reps 22 milhes de euros, j este Ve- ro

Instituto de Sistemas e Robotica

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.


141

sobre salrios Em causa est o clculo da  

E-Print Network [OSTI]

Reitores e Governo no se entendem sobre salrios Em causa est o clculo da reposio dos salrios. Governo faz com corte de 3,9% mas reitores dizem que de 3%. O Governo e os reitores esto a fazer contas milhes de euros) na sua dotao, em relao ao ano an- terior. No entanto, em Outubro, o Governo aprovou

Instituto de Sistemas e Robotica

142

Reitores reclamam reposio de milhes  

E-Print Network [OSTI]

para analisar a questo financeira que tem mantido reitores e Governo em discusso. As universida- des inteno do Governo restituir "pura e simplesmente" essa verba, mas devolv-la total ou par- cialmente, "havendo folga". Apesar de, recentemente, o CRUP ter cortado relaes com o Governo por um curto perodo de

Instituto de Sistemas e Robotica

143

Tiragem: 46555 Pas: Portugal  

E-Print Network [OSTI]

Tcnica de Lisboa (UTL), na ca- pital, o ministro da Educao, Nu- no Crato, anunciou que o Governo vai Governo. O PBLICO tentou obter uma reaco dos outros dois reitores, mas no foi possvel at hora de aprovao dos esta- tutos e o incio do processo de elei- o dos rgos de governo da nova universidade

Instituto de Sistemas e Robotica

144

Governo apresenta reforma da rede do Superior em Maro sem contributo dos reitores  

E-Print Network [OSTI]

Governo apresenta reforma da rede do Superior em Maro sem contributo dos reitores O Ministrio da, que foi criado em Setembro para apresentar a proposta das universidades ao Governo, foi co- municada que se mantm disponveis "para co- laborar com a tutela" mas s depois do Governo apresentar a sua

Instituto de Sistemas e Robotica

145

Superior reclama regime de exceo  

E-Print Network [OSTI]

- tre as instituies de Ensino Superior e o Governo. Reito- res e presidentes de institu- tos no recebeu qualquer respos- ta do Governo. J o Conselho de Reitores analisou a portaria na reu- nio instituies POLITCNICOS ENVIARAM OFICIO H UM MS, MAS AINDA NO H RESPOS- TA DO GOVERNO #12;

Instituto de Sistemas e Robotica

146

ENSINO SUPERIOR Governo cria  

E-Print Network [OSTI]

ENSINO SUPERIOR Governo cria linha de apoio para captar alunos estrangeiros Os fundos devero ser/ato. Os montantes ainda no esto defi- nidos, mas o Governo est a prepa- rar uma linha de financiamento- mento das instituies de ensino superior, congelados pelo Governo, ocorrer " medida que forem

Instituto de Sistemas e Robotica

147

Mobile agents for e-commerce Roll No. : 99329011  

E-Print Network [OSTI]

Mobile agents for e-commerce By Rahul Jha Roll No. : 99329011 Guided By Prof. Sridhar Iyer KR years, mobile agent (MA) paradigm has received a great deal of attention. While MAs have generated the effectiveness of mobile agents versus traditional approaches. This project contributes towards

Iyer, Sridhar

148

IAU Symposium 219: Stars as Suns: Activity, Evolution, Planets ASP Conference Series, Vol. XX, 2004  

E-Print Network [OSTI]

IAU Symposium 219: Stars as Suns: Activity, Evolution, Planets ASP Conference Series, Vol. XX, 2004 generation and energy release in stellar atmospheres. The nature of this interplay is surprisingly di right: VLBI image of Algol (Mutel et al. 1998; units: mas). Bottom left: Model for a radio magnetosphere

Guedel, Manuel

149

Resistencia de Materiales I Presentacion de la asignatura  

E-Print Network [OSTI]

generaliza las ecuaciones de Newton y Euler a medios no rigidos. Calculo y algebra vectorial y tensorial gobiernan el el movimiento y deformacion de los solidos (en el caso mas sencillo: elastico, lineal

Romero, Ignacio

150

Algebra lineal I, FAMAT, ene-jun, 2009 Examen parcial 1  

E-Print Network [OSTI]

Algebra lineal I, FAMAT, ene-jun, 2009 Examen parcial 1 Viernes, 13 mar, 2009 Cierto o Falso ecuaciones lineales tiene por lo menos una solucion. 2. Todo sistema homogeneo de ecuaciones lineales tiene por lo menos una solucion. 3. Si un sistema de ecuaciones lineales tiene mas que una solucion entonces

Bor, Gil

151

Algebra lineal 2, FAMAT, agto-dic, 2009 Tarea num. 12  

E-Print Network [OSTI]

Algebra lineal 2, FAMAT, agto-dic, 2009 Tarea num. 12 Para el viernes, 6 nov 2009 Definiciones. Sea T : V V un operador lineal con valor propio . El subespacio E = {v V |Tv = v} se llama el que la multiplicidad geometrica de un valor propio de un operador lineal no es mas grande que su

Bor, Gil

152

Consider consulting firms beyond the major  

E-Print Network [OSTI]

for interviews. This is not a skill that can be mas- tered in one night. Re- search company websites for practice questions Insider Advice Attend career fairs and company information sessions including the Career Expo. Along with On Campus Recruiting (OCR) consulting firms may also host company presentations and even pre

Shull, Kenneth R.

153

Discordances ontologiques et questions d'interoprabilit  

E-Print Network [OSTI]

liens, et en quoi elles sont pertinentes pour les sciences sociales. Mots clés : Epistémologie, ontologie, interopérabilité, intégration de schémas, homologie structurale Summary : Beyond the search

Paris-Sud XI, Université de

154

Effect of topological and phenological changes on biomass partitioning in Arabidopsis thaliana inflorescence: a preliminary model-based study  

E-Print Network [OSTI]

Effect of topological and phenological changes on biomass partitioning in Arabidopsis thaliana, France E-mail: letort@mas.ecp.fr Abstract Although the existence of phenological impact on biomass the variations of biomass allocated to fruits according to simple changes in the topological and phenological

Paris-Sud XI, Université de

155

Human autoantibodies against the 54 kDa protein of the signal recognition particle block function at multiple stages  

E-Print Network [OSTI]

Targoff (OMRF, Oklahoma City) for the initial iden- tification of the anti-SRP-positive reactivity in the patient sera, and Tho- mas Ludwig (Columbia University Medical Center), Paul Plotz and Terrance O'Hanlon for providing certain human sera. They thank...

Romisch, Karin; Miller, Frederick W; Dobberstein, Bernhard; High, Stephen

2006-01-26T23:59:59.000Z

156

Intgration oriente service des modles Grid et Multi-Agents  

E-Print Network [OSTI]

/Grid service, Service-oriented architecture, STROBE model, Software engineering, Mixed systems. JFSMA 2006 of a service-oriented approach. The concept of service is clearly at the intersection of GRID and MAS, Interaction, Grid, Intégration agent-Grid, Web/Grid service, Architecture orientée service, modèle STROBE

Paris-Sud XI, Université de

157

AGIL specifications Clement Jonquet, Pascal Dugenie and Stefano A. Cerri  

E-Print Network [OSTI]

-Agent Systems, Agent, STROBE model, Grid, Grid service, OGSA, Service Oriented Architecture, Web Service addresses this problem by means of a service-oriented approach. Services are exchanged (i.e., provided of the art about integration approaches in GRID, MAS and Service Oriented Computing (SOC). It secondly

Paris-Sud XI, Université de

158

Initial Effects of Brush Cutting and Shoot Removal on Willow Browse Quality Roy V. Rea1  

E-Print Network [OSTI]

range. Resumen Examinamos los efectos iniciales del corte de arbustos (remocion de toda la biomasa ae. Especificamente evaluamos los cambios de la biomasa, contenido de taninos, energia y protei's willow'' que habian recibido corte de arbusto fueron superiores en biomasa y mas bajas en protei

Gillingham, Michael

159

Devices and process for high-pressure magic angle spinning nuclear magnetic resonance  

DOE Patents [OSTI]

A high-pressure magic angle spinning (MAS) rotor is detailed that includes a high-pressure sample cell that maintains high pressures exceeding 150 bar. The sample cell design minimizes pressure losses due to penetration over an extended period of time.

Hoyt, David W; Sears, Jr., Jesse A; Turcu, Romulus V.F.; Rosso, Kevin M; Hu, Jian Zhi

2014-04-08T23:59:59.000Z

160

A. A. (TONY) EKDALE ACADEMIC POSITION  

E-Print Network [OSTI]

.C., & Ekdale, A.A., 2014, Ichnology and sedimentology of an Eocene greensand in Texas: behavioral response: Developments in Sedimentology 64, Elsevier, Amsterdam, p. 139-155. Ekdale, A.A., & Bromley, R.G., 2012, Eolian: Developments in Sedimentology 64, Elsevier, Amsterdam, p. 419-437. Gibert, J.M. de, Mas, G., & Ekdale, A

Johnson, Cari

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.


161

Communicated by M. A. Saghai Maroof V. Geffroy ( ) F. Creusot J. Falquet M. Se vignac  

E-Print Network [OSTI]

Are (Masten- broek 1960) and recently re-named Co-2 (Kelly and Young 1996). In North America, breeding · P. Gepts · M. Dron A family of LRR sequences in the vicinity of the Co-2 locus for anthracnose be facilitated by marker-assisted selec- tion (MAS). A RAPD marker, ROH20, linked to the Mesoamerican Co-2

Gepts, Paul

162

La nation l'preuve de la Bolivie. Commentaires sur le vif. Pascale Absi (IRD, UMR 201)  

E-Print Network [OSTI]

mouvements sociaux, d'Hervé Do Alto sur l'histoire du MAS, Zéline Lacombe sur les luttes régionalistes et précipitée du président Sanchez de Lozada exécuteur de l'ajustement structurel en 2003, en constituent les

Paris-Sud XI, Université de

163

The holonic enterprise: a model for Internet-enabled global manufacturing supply chain and workflow  

E-Print Network [OSTI]

The holonic enterprise: a model for Internet-enabled global manufacturing supply chain and workflow, which supports organizational information that, in turn, can mirror social organization. The Holonic with an overview of the three main concepts used to develop our HE model: holonic systems, MAS, and the Internet

Ulieru, Mihaela

164

ANO XLIII N. 086 12/06/2013 ESTE BOLETIM DE SERVIO CONSTITUDO DE 47 (QUARENTA E SETE) PGINAS  

E-Print Network [OSTI]

trabalhos apresentando os pontos de pauta: (1) Reformulação do Núcleo Docente Estruturante - NDE; (2) Reconhecimento do curso. O NDE iniciou-se com um numero grande de professores mas com a nova normativa do NDE que: MANOELA, L?CIA, ARI, ANA PAULA, CLAUDIA MORAES e AGUINALDO. A professora MANOELA sugere organizar via NDE

Souza, Max O.

165

Completeness of USNO-B for High Proper-Motion Stars  

E-Print Network [OSTI]

I test the completeness of USNO-B detections of high proper-motion (mu>0.18"/yr) stars and the accuracy of its measurements by comparing them to the revised NLTT (rNLTT) catalog of Salim & Gould. For 14.5~20mas/yr) may actually have still larger errors than tabulated.

Gould, A

2003-01-01T23:59:59.000Z

166

Sminaire Pcsi, novembre 2004, Montpellier, France 1 A. Richard,, P. Caron, J.Y. Jamin, T. Ruf (diteurs  

E-Print Network [OSTI]

or a constraint depending on ones' point of view. Multi-agent systems (MAS) are used to explore interactions between ecological and social dynamics in complex systems by creating virtual societies sharing, novembre 2004, Montpellier, France. Cirad, Montpellier France, Colloque Interactions between water use

Boyer, Edmond

167

Honors Coordinators College of Architecture  

E-Print Network [OSTI]

Kaufman Hall 101 pchambers@ou.edu O: 4931 D: 6921 Communication Prof. Young Kim Burton Hall 101 youngkim Dr. Jennifer Barnes DAHT jbarnes@ou.edu O: 1942 D: 4708 Religious Studies Prof. Lee Green Robertson@ou.edu O: 6778 D: 2921 Gaylord College of Journalism& Mas Journalism & Mass Communication Dr. John Hockett

Oklahoma, University of

168

LiU E-Press Linkoping University Electronic Press 2006-01  

E-Print Network [OSTI]

for the E-Press. Increasing the publication of PhD and licentiate theses has been our first priority on the committee report, specifies two major priorities: to increase the publication of doctorate and licentiate(1 reasons 1 The licentiate degree is a Swedish research degree that is in-between the mas- ter

Zhao, Yuxiao

169

E.T.S.I. Industriales: Resistencia de Materiales 2 PROBLEMAS TEMA 5: MEMBRANAS DE  

E-Print Network [OSTI]

3 mm calcular las tensiones en los puntos mas cercanos al eje de revolucion. 5.4 Un deposito esferico casquete esferico de altura h y radio r V = 3 h2 (3r - h) z r e 2 #12;

Romero, Ignacio

170

Normative Agents in Health Care: Uses and Challenges  

E-Print Network [OSTI]

Normative Agents in Health Care: Uses and Challenges Javier V´azquez-Salceda institute;Normative Agents in Health Care: Uses and Challenges Javier V´azquez-Salceda 1 Abstract. The use of Multi-Agent Systems (MAS) in health-care domains is increasing. Such Agent-mediated Medical Systems are designed

Utrecht, Universiteit

171

Perspective The NEW ENGLAND JOURNAL of MEDICINE  

E-Print Network [OSTI]

in Mas- sachusetts' special Senate election in January sent health care reform into a tailspin. Democrats- ing, as attention turned to the merits of more incremental re- forms. Yet as the health care reform, the political outlook for health care reform is improving, and Democrats are now close to securing enough votes

Whitton, Mary C.

172

2013 Graduate Research and Arts Symposium Posters and Exhibits: Tentative Schedule  

E-Print Network [OSTI]

-Assisted Selection (MAS) to Improve Alfalfa (Medicago sativa L.) Drought Tolerance NMSU Plant and Environmental of Carbon Isotope Discrimination in Drought-stressed Alfalfa (Medicago sativa L.) NMSU Plant of MS2 virus spiked to Nannochloropsis salina grown in wastewater NMSU Biology 16 #12;2013 Graduate

Johnson, Eric E.

173

Astronomy & Astrophysics manuscript no. 16193paper.hyper2884 c ESO 2010 December 13, 2010  

E-Print Network [OSTI]

disc. We measured the dusty disc inner inner rim, i.e. 6 mas, constrained the inclination angle of the dense equatorial disc. Moreover, as the expansion velocity is negligible, radiatively driven wind). Fast rotation of the star leads to an expanding disc-like wind in the case of very massive stars

Boyer, Edmond

174

arXiv:astro-ph/0608427v121Aug2006 Pinwheels in the Quintuplet Cluster  

E-Print Network [OSTI]

spiral model with winding angle 110±10mas/turn and with an inclination of the rotation axis to the line which resolves this debate with the discovery of rotating spiral plumes charac- teristic of colliding-wind character- istic of colliding-wind binary "pinwheel" nebulae. These have previously been reported in dust

Monnier, John D.

175

TuCCompi: A Multi-Layer Programing Model for Heterogeneous Systems with Auto-Tuning Capabilities  

E-Print Network [OSTI]

kernel. 4.5 Advanced TuCCompi Model Features TuCCompi model has additional functionalities and features for the functions, mas- ter (top) and slave (bottom), of the distribution plug-in. tational power, the master that copies are not made or distributed for profit or commercial advantage and that copies bear this notice

Llanos, Diego R.

176

Agent-Grid Integration Ontology Frederic Duvert, Clement Jonquet, Pascal Dugenie, and Stefano A. Cerri  

E-Print Network [OSTI]

Agent-Grid Integration Ontology Frederic Duvert, Clement Jonquet, Pascal Dugenie, and Stefano A, jonquet, dugenie, cerri}@lirmm.fr Abstract. The integration of GRID and MAS (Multi-Agents Systems) is an active research topic. We have recently proposed the Agent-Grid Integration Lan- guage, to describe

Paris-Sud XI, Universit de

177

Direct Determination of Levoglucosan at the Picogram per Milliliter Level in Antarctic Ice by  

E-Print Network [OSTI]

techniques have been used for MAs analysis including gas chromatography/mass spectrometry (GC/ MS) after at the picogram per milliliter level in less than 1 mL of Antarctic ice has been developed. Chemical analysis by acting as cloud condensation nuclei,1 often affecting regional and local air quality. In the past few

Howat, Ian M.

178

In The Fourth International Joint Conference on Autonomous Agents and Multiagent Systems (AAMAS 05) pp. 471-477, Utrecht, The Netherlands, July 2005.  

E-Print Network [OSTI]

) pp. 471-477, Utrecht, The Netherlands, July 2005. Multiagent Traffic Management: An Improved this notice and the full citation on the first page. To copy otherwise, to republish, to post on servers, Netherlands. Copyright 2005 ACM 1-59593-094-9/05/0007 ...$5.00. Multiagent Systems (MAS) is the subfield of AI

López-Sánchez, Maite

179

POUR UNE CULTURE DES ACCIDENTS AU SERVICE DE LA SECURITE INDUSTRIELLE  

E-Print Network [OSTI]

-organisational character), locate it in the state of art with regards to accidentology, safety and risk cultures. FinallyPOUR UNE CULTURE DES ACCIDENTS AU SERVICE DE LA SECURITE INDUSTRIELLE FOR A CULTURE OF ACCIDENTS DEVOTED TO INDUSTRIAL SAFETY Nicolas DECHY Yves DIEN Michel LLORY INERIS EDF R&D IAO, Mas Saint

Paris-Sud XI, Université de

180

Zweite Satzung zur nderung der Zulassungsordnung der Universitt Stuttgart fr den Deutsch-Franzsischen Masterstudiengang Empirische Politik-und Sozialforschung  

E-Print Network [OSTI]

1 Zweite Satzung zur ?nderung der Zulassungsordnung der Universität Stuttgart für den Deutsch Zulassungsordnung für den Deutsch-Französischen Mas- terstudiengang Empirische Politik- und Sozialforschung vom 27: ,,(2) Wurden im deutsch-französischen Bachelorstudiengang oder im gleichwertigen Stu- diengang nicht

Möbius, Bernd

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.


181

Electrical Engineering Department Los Angeles, California 90095-1594  

E-Print Network [OSTI]

plasma into a "magnetic bucket," or processing chamber covered with a permanent magnet array to provide, and a small solenoid produc- ing fields B up to 100G. QUARTZ TUBE PVC PIPE ANTENNA MAGNET WINDING 7 cm 5 cm 13 and field coil still did not produce helicon discharges. These were ICPs (Inductively Coupled Plas- mas

Chen, Francis F.

182

Field evaluation of cotton near-isogenic lines introgressed with QTLs for productivity and drought related traits  

E-Print Network [OSTI]

Field evaluation of cotton near-isogenic lines introgressed with QTLs for productivity and drought) between elite cultivars of the two cotton species Gossypium barbadense cv. F-177 and G. hirsutum cv. Siv, in order to (1) evaluate the potential to improve cotton drought resistance by MAS and (2) test the role

Chee, Peng W.

183

Direct Speciation of Phosphorus in Alum-Amended Poultry Litter  

E-Print Network [OSTI]

Direct Speciation of Phosphorus in Alum-Amended Poultry Litter: Solid-State 31 P NMR Investigation, and Department of Plant and Soil Sciences, University of Delaware, Newark, Delaware 19717 Amending poultry litter prerequisite for the assessment of the sustainability of intensive poultry operations. Both solid- state MAS

Sparks, Donald L.

184

Perturbation of nuclear spin polarizations in solid state NMR of nitroxide-doped samples by magic-angle spinning without microwaves  

SciTech Connect (OSTI)

We report solid state {sup 13}C and {sup 1}H nuclear magnetic resonance (NMR) experiments with magic-angle spinning (MAS) on frozen solutions containing nitroxide-based paramagnetic dopants that indicate significant perturbations of nuclear spin polarizations without microwave irradiation. At temperatures near 25 K, {sup 1}H and cross-polarized {sup 13}C NMR signals from {sup 15}N,{sup 13}C-labeled L-alanine in trinitroxide-doped glycerol/water are reduced by factors as large as six compared to signals from samples without nitroxide doping. Without MAS or at temperatures near 100 K, differences between signals with and without nitroxide doping are much smaller. We attribute most of the reduction of NMR signals under MAS near 25 K to nuclear spin depolarization through the cross-effect dynamic nuclear polarization mechanism, in which three-spin flips drive nuclear polarizations toward equilibrium with spin polarization differences between electron pairs. When T{sub 1e} is sufficiently long relative to the MAS rotation period, the distribution of electron spin polarization across the nitroxide electron paramagnetic resonance lineshape can be very different from the corresponding distribution in a static sample at thermal equilibrium, leading to the observed effects. We describe three-spin and 3000-spin calculations that qualitatively reproduce the experimental observations.

Thurber, Kent R., E-mail: thurberk@niddk.nih.gov; Tycko, Robert [Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520 (United States)] [Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520 (United States)

2014-05-14T23:59:59.000Z

185

Pas: Portugal Period.: Diria  

E-Print Network [OSTI]

com validade de séculos. Há um ano tornou-se curador do departamento de Design e Arquitectura do Museu do futebol, mas na arquitectura e no cinema é onde temos visto emergir novos valores, com gente-se fazendo. No campo da arquitectura começa com Siza, Távora e outras referências dos anos 50 com

Instituto de Sistemas e Robotica

186

MICROPROTEOMICS: ANALYSIS OF PROTEIN DIVERSITY IN SMALL SAMPLES  

E-Print Network [OSTI]

MICROPROTEOMICS: ANALYSIS OF PROTEIN DIVERSITY IN SMALL SAMPLES Howard B. Gutstein,1 * Jeffrey S.interscience.wiley.com) DOI 10.1002/mas.20161 Proteomics, the large-scale study of protein expression in organisms, offers be expressed by the genetic material of an organism. Advancements in protein extraction, purification

187

Infrared emission spectroscopy of CO2 at high temperature. Part I: Experimental setup and source  

E-Print Network [OSTI]

Infrared emission spectroscopy of CO2 at high temperature. Part I: Experimental setup and source An experimental setup is developed to analyze infrared emission of CO2 plas- mas at atmospheric pressure using CO emission in the overtone vibrational bands v=2. Analysis of the measurements of CO2 emission

Boyer, Edmond

188

Methylated trivalent arsenicals are potent inhibitors of glucose stimulated insulin secretion by murine pancreatic islets  

SciTech Connect (OSTI)

Epidemiologic evidence has linked chronic exposure to inorganic arsenic (iAs) with an increased prevalence of diabetes mellitus. Laboratory studies have identified several mechanisms by which iAs can impair glucose homeostasis. We have previously shown that micromolar concentrations of arsenite (iAs{sup III}) or its methylated trivalent metabolites, methylarsonite (MAs{sup III}) and dimethylarsinite (DMAs{sup III}), inhibit the insulin-activated signal transduction pathway, resulting in insulin resistance in adipocytes. Our present study examined effects of the trivalent arsenicals on insulin secretion by intact pancreatic islets isolated from C57BL/6 mice. We found that 48-hour exposures to low subtoxic concentrations of iAs{sup III}, MAs{sup III} or DMAs{sup III} inhibited glucose-stimulated insulin secretion (GSIS), but not basal insulin secretion. MAs{sup III} and DMAs{sup III} were more potent than iAs{sup III} as GSIS inhibitors with estimated IC{sub 50} ? 0.1 ?M. The exposures had little or no effects on insulin content of the islets or on insulin expression, suggesting that trivalent arsenicals interfere with mechanisms regulating packaging of the insulin transport vesicles or with translocation of these vesicles to the plasma membrane. Notably, the inhibition of GSIS by iAs{sup III}, MAs{sup III} or DMAs{sup III} could be reversed by a 24-hour incubation of the islets in arsenic-free medium. These results suggest that the insulin producing pancreatic ?-cells are among the targets for iAs exposure and that the inhibition of GSIS by low concentrations of the methylated metabolites of iAs may be the key mechanism of iAs-induced diabetes. - Highlights: ? Trivalent arsenicals inhibit glucose stimulated insulin secretion by pancreatic islets. ? MAs{sup III} and DMAs{sup III} are more potent inhibitors than arsenite with IC{sub 50} ? 0.1 ?M. ? The arsenicals have little or no effects on insulin expression in pancreatic islets. ? The inhibition of insulin secretion by arsenite, MAs{sup III} or DMAs{sup III} is reversible. ? Thus, pancreatic ?-cells may be primary targets for chronic exposure to arsenic.

Douillet, Christelle [Department of Nutrition, Gillings School of Global Public Health, 2302 MHRC, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7461 (United States); Currier, Jenna [Curriculum in Toxicology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7461 (United States); Saunders, Jesse [Department of Nutrition, Gillings School of Global Public Health, 2302 MHRC, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7461 (United States); Bodnar, Wanda M. [Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7431 (United States); Matouek, Tom [Institute of Analytical Chemistry of the ASCR, v.v.i., Veve? 97, 602 00 Brno (Czech Republic); Stblo, Miroslav, E-mail: styblo@med.unc.edu [Department of Nutrition, Gillings School of Global Public Health, 2302 MHRC, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7461 (United States)

2013-02-15T23:59:59.000Z

189

Rapid estimation of 4DCT motion-artifact severity based on 1D breathing-surrogate periodicity  

SciTech Connect (OSTI)

Purpose: Motion artifacts are common in patient four-dimensional computed tomography (4DCT) images, leading to an ill-defined tumor volume with large variations for radiotherapy treatment and a poor foundation with low imaging fidelity for studying respiratory motion. The authors developed a method to estimate 4DCT image quality by establishing a correlation between the severity of motion artifacts in 4DCT images and the periodicity of the corresponding 1D respiratory waveform (1DRW) used for phase binning in 4DCT reconstruction. Methods: Discrete Fourier transformation (DFT) was applied to analyze 1DRW periodicity. The breathing periodicity index (BPI) was defined as the sum of the largest five Fourier coefficients, ranging from 0 to 1. Distortional motion artifacts (excluding blurring) of cine-scan 4DCT at the junctions of adjacent couch positions around the diaphragm were classified in three categories: incomplete, overlapping, and duplicate anatomies. To quantify these artifacts, discontinuity of the diaphragm at the junctions was measured in distance and averaged along six directions in three orthogonal views. Artifacts per junction (APJ) across the entire diaphragm were calculated in each breathing phase and phase-averaged APJ{sup }, defined as motion-artifact severity (MAS), was obtained for each patient. To make MAS independent of patient-specific motion amplitude, two new MAS quantities were defined: MAS{sup D} is normalized to the maximum diaphragmatic displacement and MAS{sup V} is normalized to the mean diaphragmatic velocity (the breathing period was obtained from DFT analysis of 1DRW). Twenty-six patients free-breathing 4DCT images and corresponding 1DRW data were studied. Results: Higher APJ values were found around midventilation and full inhalation while the lowest APJ values were around full exhalation. The distribution of MAS is close to Poisson distribution with a mean of 2.2 mm. The BPI among the 26 patients was calculated with a value ranging from 0.25 to 0.93. The DFT calculation was within 3 s per 1DRW. Correlations were found between 1DRW periodicity and 4DCT artifact severity: ?0.71 for MAS{sup D} and ?0.73 for MAS{sup V}. A BPI greater than 0.85 in a 1DRW suggests minimal motion artifacts in the corresponding 4DCT images. Conclusions: The breathing periodicity index and motion-artifact severity index are introduced to assess the relationship between 1DRW and 4DCT. A correlation between 1DRW periodicity and 4DCT artifact severity has been established. The 1DRW periodicity provides a rapid means to estimate 4DCT image quality. The rapid 1DRW analysis and the correlative relationship can be applied prospectively to identify irregular breathers as candidates for breath coaching prior to 4DCT scan and retrospectively to select high-quality 4DCT images for clinical motion-management research.

Li, Guang, E-mail: lig2@mskcc.org; Caraveo, Marshall [Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York 10065 (United States); Wei, Jie [Department of Computer Science, City College of New York, New York, New York 10031 (United States); Rimner, Andreas; Wu, Abraham J.; Goodman, Karyn A. [Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York 10065 (United States); Yorke, Ellen [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York 10065 (United States)

2014-11-01T23:59:59.000Z

190

The influence of fiber/matrix interface on the mechanical behavior of Nicalon SiC fiber reinforced glass-ceramic composites  

SciTech Connect (OSTI)

Mechanical properties of unidirectional Nicalon SiC fiber reinforced Ca aluminosilicate (CAS/SiC) and Mg aluminosilicate (MAS/SiC) glass-ceramic composites were investigated by tensile testing and nondestructive laser-ultrasound technique. The Ba-stuffed MAS was either undoped or doped with 5% borosilicate glass. Degradation of elastic stiffness constant C{sub 11} in transverse direction due to interface damage was monitored in situ by measuring the laser- generated ultrasound wave velocity. The three composite materials show different characteristics of macroscopic deformation behavior, which is correlated strongly to interface degradation. A stronger reduction trend of the elastic constant C{sub 11} is associated with a larger degree of inelastic deformation. The fracture surfaces also reveal the close relation between fiber pullout length and interfacial characteristics. Interfaces of these composites were studied by TEM; their influence on inhibiting and deflecting matrix cracks is discussed.

Liu, Y.M.; Mitchell, T.E. [Los Alamos National Lab., NM (United States); Wadley, H.N.G. [Virginia Univ., Charlottesville, VA (United States). Dept. of Materials Science and Engineering

1996-11-01T23:59:59.000Z

191

Faint Blue Objects in the Hubble Deep Field South Revealed: White Dwarfs, Subdwarfs, and Quasars  

E-Print Network [OSTI]

We explore the nature of the faint blue objects in the Hubble Deep Field South. We have derived proper motions for the point sources in the Hubble Deep Field South using a 3 year baseline. Combining our proper motion measurements with spectral energy distribution fitting enabled us to identify 4 quasars and 42 stars, including 3 white dwarf candidates. Two of these white dwarf candidates, HDFS 1444 and 895, are found to display significant proper motion, 21.1 $\\pm$ 7.9 mas/yr and 34.9 $\\pm$ 8.0 mas/yr, and are consistent with being thick disk or halo white dwarfs located at ~2 kpc. The other faint blue objects analyzed by Mendez & Minniti do not show any significant proper motion and are inconsistent with being halo white dwarfs; they do not contribute to the Galactic dark matter. The observed population of stars and white dwarfs is consistent with standard Galactic models.

Mukremin Kilic; R. A. Mendez; Ted von Hippel; D. E. Winget

2005-07-22T23:59:59.000Z

192

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

SciTech Connect (OSTI)

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

193

Sminaire Pcsi, novembre 2004, Montpellier, France 1 A. Richard, P. Caron, J.Y. Jamin, T. Ruf (diteurs  

E-Print Network [OSTI]

*, Mostafa ERRAHJ* *Ecole Nationale d'Agriculture, Meknès, Maroc **Cirad, Montpellier, France Résumé -- L'un périmètre irrigué au nord du Maroc que les schémas hydrauliques ont laissé en dehors des zones desservies éclairage, à travers l'étude de cas d'un périmètre irrigué en grande hydraulique au Maroc, sur les attitudes

Boyer, Edmond

194

BANCROFTIANA NE W S L E T T E R O F T H E FR I E N D S O F T H E BA N C R O F T LI B R A RY  

E-Print Network [OSTI]

BANCROFTIANA NE W S L E T T E R O F T H E FR I E N D S O F T H E BA N C R O F T LI B R A RY N U M B-1836. In the role of offi- cial artist, Lewis had accompanied Tho- mas L. McKenney, Superintendent of the Bureau the portraits when he returned to Detroit. Learning that McKenney planned to publish a "Portrait Gallery

California at Berkeley, University of

195

Minor Actinides Loading Optimization for Proliferation Resistant Fuel Design - BWR  

SciTech Connect (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

196

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 (pendant 2 ans) sera accordée au candidat retenu. Le projet sera réalisé en partenariat étroit avec l'AECL collaboration avec AECL. Solution retenue Comme l´équation de transport qui régit le comportement des neutrons

Meunier, Michel

197

V Encuentro de Mujeres de Iberoamrica en las Arts Escnicas  

E-Print Network [OSTI]

las calles de las del trafico de drogas y robos. Hoy su asociacin de vecinos es un ejemplo a seguir, contamos FALL 2002 155 con la colaboracin de las asociaciones de jvenes cargadores, ecologistas, comercio, panaderos, artesanos. Creamos el..., tranquilamente transmite optimismo, inteligencia y simpata. "Estoy mas arregla y ms informal. Mi cabeza est buena y sabe lo que quiere. No olvidemos del amor." Martirio. Cdiz ...

Ortega, Isabel

2002-10-01T23:59:59.000Z

198

Mec^anica Geometrica A entregar ate `a aula de Quarta-feira dia 27 de Outubro  

E-Print Network [OSTI]

Sistema Solar conservam o momento angular mas tendem a dissipar energia). 3. (a) Mostre que a express¸c~oes em torno de e3 s~ao est´aveis. (c) Se I1 > I2 > I3 ent~ao para um dado momento angular a energia cin~ao local da energia cin´etica de um corpo r´igido com um ponto fixo e I1 = I2 nas coordenadas de TSO(3

Natário, José

199

Outros sites Impresa: SIC TV Mais Escape Olhares J. Letras V. Jnior E. Informtica Infoportugal Casas Empregos Assine j HOME WINDOWS 8 IPHONE 5 VDEOS INSLITOS EMPREGOS TI  

E-Print Network [OSTI]

solares do mundo ­ mas em 2014 vai passar a ser conhecida por albergar as 10 estações de antenas que vão da Contenda. Em janeiro, arrancam os trabalhos relacionados com o fornecimento de energia elétrica FACEBOOK EI outro local no nosso continente que tenha tanta exposição solar e tantas condições espetrais

Instituto de Sistemas e Robotica

200

Unidades de Energa Energa mecanica  

E-Print Network [OSTI]

refrescos) = 11.7 kilowatt-hora (1 foco prendido 117 hrs)] Energa solar Radiacion solar en la tierra: 1 kilowatt por metro cuadrado (max.) [El promedio es la 1/4 parte. Un calentador solar da 60 %; celda-watt-segundo ; 1 cerrillo que se quema = 1 kilo-joule; 1 latido de corazon = 0.5 joules Mas informacion: http://es.wikipedia.org/wiki/Energia

Bor, Gil

Note: This page contains sample records for the topic "mas mas mas" from the National Library of EnergyBeta (NLEBeta).
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We encourage you to perform a real-time search of NLEBeta
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201

An autonomous long-term fast reactor system and the principal design limitations of the concept  

E-Print Network [OSTI]

Actinides MOX Mixed OXide MSR Molten-Salt Reactors NERI Nuclear Energy Research Initiative vii PWR Pressurized Water Reactor RGPu Reactor-Grade Plutonium SCNES Self-Consistent Nuclear Energy System STAR Secure Transportable Autonomous Reactor... of LWR?s, the drastic increase of Am and Cm inventories are observed after uranium fuel irradiation and the second recycling of MOX fuel.1 Therefore, partitioning and transmutation of the recovered MA?s could significantly reduce the long...

Tsvetkova, Galina Valeryevna

2004-09-30T23:59:59.000Z

202

Energas Renovables No Convencionales  

E-Print Network [OSTI]

a renovables 17% del costo total del sistema en 2009) y alta penetración Fuente: Revista IEEE Power & EnergyEnergías Renovables No Convencionales Hugh Rudnick Mas allá de la malla Pastoral UC Santiago, 17 a la entrada · Investigación en la PUC 2 #12;Motivación desarrollo renovables · Característica de

Dixon, Juan

203

Inovao Tecnolgica em Portugal: Que papel para os Doutorados Paulo Ferreira1  

E-Print Network [OSTI]

à base de cortiça ou de fibras têxteis que provasse ser essencial, por exemplo, para o fabrico de universidade. Estes dados mostram dois factos simples mas importantes. Por um lado, ilustram a diferença na dados indicam que a presença de actividades associadas à ciência e tecnologia não está, nos Estados

Ferreira, Paulo J.

204

Lick Northern Proper Motion Program. III. Lick NPM2 Catalog  

E-Print Network [OSTI]

The Lick Northern Proper Motion (NPM) program, a two-epoch (1947-1988) photographic survey of the northern two-thirds of the sky (Dec. > -23 deg), has measured absolute proper motions, on an inertial system defined by distant galaxies, for 380,000 stars from 8 NPM1 Catalog contains 148,940 stars in 899 fields outside the Milky Way's zone of avoidance. The 2003 NPM2 Catalog contains 232,062 stars in the remaining 347 NPM fields near the plane of the Milky Way. This paper describes the NPM2 star selection, plate measurements, astrometric and photometric data reductions, and catalog compilation. The NPM2 Catalog contains 120,000 faint (B > 14) anonymous stars for astrometry and galactic studies, 92,000 bright (B NPM2 proper motions are on the ICRS system, via Tycho-2 stars, to an accuracy of 0.5 mas/yr in each field. RMS proper motion precision is 6 mas/yr. Positional errors average 80 mas at the mean plate epoch 1968, and 200 mas at the NPM2 catalog epoch 2000. NPM2 photographic photometry errors average 0.18 mag in B, and 0.20 mag in B-V. The NPM2 Catalog and the updated (to J2000) NPM1 Catalog are available at the CDS Strasbourg data center and on the NPM WWW site (http://www.ucolick.org/~npm). The NPM2 Catalog completes the Lick Northern Proper Motion program after a half-century of work by three generations of Lick Observatory astronomers. The NPM Catalogs will serve as a database for research in galactic structure, stellar kinematics, and astrometry.

Robert B. Hanson; Arnold R. Klemola; Burton F. Jones; David G. Monet

2004-06-07T23:59:59.000Z

205

La evolucion del modernismo en Puerto Rico  

E-Print Network [OSTI]

imagen, incorporo a las letras un nuevo mundo de sensaciones, enriquecio el lexico, flexibilizo la sintaxis, [y] transformo el verso con nuevos matices y recursos de expresion . . . " (20). Etapas Corno podemos apreciar, la importancia de este... cos- mopolita, lo divino y lo terrenal, y lo humano y lo ani- mal. Veamos pues, cuales fueron los temas mas signi- ficativos cultivados por los poetas modernistas. Los mismos son: la angustia o fatalismo, el patriotismo, la naturaleza, el exotismo...

Gonzalez-Hernandez, Miriam Mercedes

1989-01-01T23:59:59.000Z

206

Discordances ontologiques et questions d'interoprabilit  

E-Print Network [OSTI]

liens, et en quoi elles sont pertinentes pour les sciences sociales. Mots clés : Epistémologie, ontologie, interopérabilité, intégration de schémas, homologie structurale Summary : Beyond the search terrain d'étude ethnologique. Après avoir quelque peu précisé ces deux questions, ainsi que les liens qu

Boyer, Edmond

207

The Path to the Table: Cooking in Postwar American Suburbs  

E-Print Network [OSTI]

structures that were physical reflections of a psychological mindset. Instead, the ranch house, the epitome of postwar housing, used large picture windows, patios, and brezeways to open up the house and minimize the divisions betwen indoor and outdoor... with a law that limited citizenship to "fre white people," which had the efect of making whitenes and blacknes the overiding division betwen Americans. The second era began in the 1840s with the mas migration of the Irish and, to a leser extent...

Miller, Timothy

2008-08-08T23:59:59.000Z

208

COBI cobi12199 Dispatch: October 31, 2013 CE: AFL Journal MSP No. No. of pages: 10 PE: XXXXX1  

E-Print Network [OSTI]

abitat Potencial de Descanso de la Grulla Americana para Guiar la Seleccion de Sitios para Proyectos de Energia Eolica energia eolica se vuelva cada vez mas importante. Usamos esta informacion para identificar areas conflictos entre las grullas y el desarrollo de energia eolica. Sugerimos que este tipo de analisis sea

Minor, Emily

209

Desmatamento, trajetrias tecnolgicas rurais e metas De  

E-Print Network [OSTI]

ambiental, por intermédio de medidas de co- mando e controle, mas também de incentivos creditícios impacto na biodiversidade) e baixa formação de dejetos/impacto poluidor". ·"Trajetória Patronal T4: reúne- zação da paisagem (alto impacto na biodiversidade) e formação intensa de dejetos". ·"Trajetória Camponês

Camara, Gilberto

210

ENGENHARIA QUMICA Coordenador: Prof Dr. D. Javier Aguado Marugan  

E-Print Network [OSTI]

impacto ambiental e análise econômica do processo. O engenheiro químico usa matemática e física, mas Facebook Curso de articulação com: Engenharia de Energia , Engenharia Ambiental , Engenharia Industrial ambiente. Uma das características do Engenheiro químico, com relação a outros ramos da engenharia, é a sua

Rey Juan Carlos, Universidad

211

Metas Nacionais de Reduo do Desmatamento: possvel alcan-las? Uma proposta a partir das diferentes  

E-Print Network [OSTI]

menor impacto sobre a cobertura florestal. Como, porém ­ e precisamente ­, o desmatamento majoritário legislação ambiental, por intermédio de medidas de comando e controle, mas também de incentivos creditícios poderia tratar em separado. Ora, a questão do desmatamento não é somente ambiental, nem somente de

Camara, Gilberto

212

ENERGY, CLIMATE AND SUSTAINABLE  

E-Print Network [OSTI]

ENERGY, CLIMATE AND SUSTAINABLE DEVELOPMENT NAMAs and the Carbon Market Nationally Appropriate . . . . . . . . . . . 63 ChristianEllermann, NaMas FOr disPersed eNergy eNd-Use sectOrs: Using the building sectorDenmark,theNetherlandsMinistryofForeignAffairs,nortotherespectiveorganizationsofeachindividualauthor. CapacityDevelopmentforCDM(CD4CDM)Project UNEPRisøCentre, RisøNationalLaboratoryforSustainableEnergy The

213

266 kULLE`fIN OF TBE UNITED STATES FISH COMRniIISSIGN. that off-shore wi& creates an enormous overtow j and, as it does not  

E-Print Network [OSTI]

Francisco Bulletin. Under date of March 4,1884, he says : "1 first sew French carp in the autumn of 1837-pond,in the center of *ehich was a sinall is- land surmounted bg a summer-honse, mas midway between the broad front the bridge could be seen hund- reds of French carp, which Captain Robinson,had himself brought?with great

214

Communiqu de presse -27 fvrier 2013 Expdition Papouasie-Nouvelle-Guine  

E-Print Network [OSTI]

contreforts du Mont Wilhelm, ils ont inventorié la biodiversité négligée de cette région- clé mais sous sur le terrain. Les travaux de tri et d'identification des spécimens ont à peine commencé, et il des piégeages similaires dans une forêt de plaine). Les schémas de répartition de la biodiversité ne

215

Serum proteins, indirect fluorescent antibody titers and complement fixing antibody titers in dexamethasone exacerbated anaplasmosis carrier calves  

E-Print Network [OSTI]

SERUM PROTEINS, INDIRECT FLUORESCENT ANTIBODY TITERS AND COMPLEMENT FIXING ANTIBODY TITERS IN DEXAMETHASONE EXACERBATED ANAPLASMOSIS CARRIER CALVES A Thesis by Lloran Wesley Johnson Submitted to the Graduate College of Texas A%M University... in partial fulfillment of the requirement for the degree of MAS TER 0 F SC I ENC E August 1979 Major Subject: Veterinary Microbiology SERUM PROTEINS, INDIRECT FLUORESCENT ANTIBODY TITERS AND COMPLEMENT FIXING ANTIBODY TITERS IN DEXAMETHASONE EXACERBATED...

Johnson, Lloran Wesley

2012-06-07T23:59:59.000Z

216

Com criatividade e alguns conhecimentos, j possvel criar um aparelho eletrnico  

E-Print Network [OSTI]

as informações pretendidas. A primeira placa eletrónica sobre a qual se debruçaram foi o Arduino, tendo sido desenho próprio mas inspirado no Arduino, que superava os constrangimen- tos encontrados. Nascia o Bl Arduino, é o facto de poder adquirir sinais múltiplos sem grandes complicações, graças a uma eficaz

Instituto de Sistemas e Robotica

217

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

E-Print Network [OSTI]

COMPARATIVE GENOMICS OF GOSSYPIUM SPP. THROUGH GBS AND CANDIDATE GENES ? DELVING INTO THE CONTROLLING FACTORS BEHIND PHOTOPERIODIC FLOWERING A Dissertation by CARLA JO LOGAN YOUNG Submitted to the Office of Graduate Studies of Texas A.../Deletion Polymorphism IPGB Institute for Plant Genomics and Biotechnology Ka Non-synonymous Nucleotide Substitution Rate kb Kilobase(s) kDa KiloDalton Ks Synonymous Nucleotide Substitution Rate LD Long Day LD Linkage Disequilibrium MAS Marker Assisted...

Young, Carla Jo Logan

2013-08-09T23:59:59.000Z

218

Projeto de pesquisa da UFSC visa  

E-Print Network [OSTI]

duas não têm restrição explícita à pesca, mas são importantes patrimônios ecológicos (Ilha do Campeche- roupa e o badejo-mira) não teve significativas diferenças em rela- ção às ilhas do Campeche e do

Floeter, Sergio Ricardo

219

A review of "Thomas and Rebecca Vaughans Aqua Vit: Non Vitis" by Donald R. Dickson, ed.  

E-Print Network [OSTI]

to contemporary Anglican sufferings, is an important contribution to understanding. Donald R. Dickson, ed. Thomas and Rebecca Vaughan?s Aqua Vit?: Non Vitis (British Library MS, Sloane 1741). Tempe: Arizona Center for Medieval and Renaissance Studies, 2001... is to be congratulated and thanked for this volume. Nothing by Tho- mas Vaughan has ever appeared in so handsome a format. Donald Dickson, too, is to be congratulated and thanked. Sloane MS 1741, if not quite in the Aubrey league, still has its difficulties...

Alan Rudrum

2003-01-01T23:59:59.000Z

220

Volume 6 Issue 2 January 9, 2012 Open Funding Opportunities  

E-Print Network [OSTI]

No. ITA-MAS-OPCM-2012-2003089 CFDA No. 11.112 Due Date: 21 February 2012 http://www07.grants. ONRBAA12-005 CFDA No. 12.300 Due Date: White Papers: 2/15/2012 Full Proposals: 5/1/2012 http://www07 and Centers Program-Field Initiated Projects Program Solicitation No. 2011-33807 CFDA No. 84.133G Due Date: 5

Alabama in Huntsville, University of

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.


221

Tiragem: 18100 Pas: Portugal  

E-Print Network [OSTI]

Alemanhatemum déficedemaisde70milengenheiros. "Apesar da grande propaganda das hipóteses para o Brasil e países africa- nos para os 39%. E o Brasil? O Brasil precisa de 290 mil engenheiros civis, mas quanto à hipóteses de. "Há o caso de empresas portuguesas que vão para o Brasil e levam engenheiros. Depois há as companhias

Instituto de Sistemas e Robotica

222

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

SciTech Connect (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} < 50 mas, and a 1 in 10 chance that {rho}{sub min} < 20 mas. The last would result in a microlensing event with a 6% magnification in the 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

223

A, Science Service Feature Released on receipt  

E-Print Network [OSTI]

THE WEATHER Mailed December 13, 1927 By Charles Mtzhugh Talman, Authority on Meteorology UNDfBGROUND ICE Large mas8es of more or l e s s clear ice are found i n the permanently frozen ground of high 1 8 t i t U d e s j as, for examplo,the subsoil of the Siberian tundrm, Such ice is variously known as "ground ice

224

High-temperature steam-treatment of PBI, PEEK, and PEKK polymers with H2O and D2O: A solid-state NMR study  

E-Print Network [OSTI]

High-temperature steam-treatment of PBI, PEEK, and PEKK polymers with H2O and D2O: A solid 2014 Keywords: Steam-treatment of PBI, PEEK, PEKK Solid-state NMR Water and D2O uptake polymers a b with D2O steam at temperatures of 150 and 315 C. All samples are studied by TGA, IR, 13 C CP/MAS, 1 H

Bluemel, Janet

225

Dissecting the AGB star L2 Puppis: a torus in the making  

E-Print Network [OSTI]

The circumstellar environment of L2 Pup, an oxygen-rich semiregular variable, was observed to understand the evolution of mass loss and the shaping of ejecta in the late stages of stellar evolution. High-angular resolution observations from a single 8 m telescope were obtained using aperture masking in the near-infrared (1.64, 2.30 and 3.74 $\\rm\\mu m$) on the NACO/VLT, both in imaging and polarimetric modes. The aperture-masking images of L2 Pup at 2.30 $\\rm\\mu m$ show a resolved structure that resembles a toroidal structure with a major axis of ~140 milliarcseconds (mas) and an east-west orientation. Two clumps can be seen on either side of the star, ~65 mas from the star, beyond the edge of the circumstellar envelope (estimated diameter is ~27 mas), while a faint, hook-like structure appear toward the northeast. The patterns are visible both in the imaging and polarimetric mode, although the latter was only used to measure the total intensity (Stokes I). The overall shape of the structure is similar at the ...

Lykou, F; Paladini, C; Hron, J; Zijlstra, A A; Kluska, J; Norris, B R M; Tuthill, P G; Ramstedt, S; Lagadec, E; Wittkowski, M; Maercker, M; Meisner, J; Mayer, A

2015-01-01T23:59:59.000Z

226

THE CELESTIAL REFERENCE FRAME AT 24 AND 43 GHz. I. ASTROMETRY  

SciTech Connect (OSTI)

We present astrometric results for compact extragalactic objects observed with the Very Long Baseline Array at radio frequencies of 24 and 43 GHz. Data were obtained from ten 24 hr observing sessions made over a five-year period. These observations were motivated by the need to extend the International Celestial Reference Frame (ICRF) to higher radio frequencies to enable improved deep space navigation after 2016 and to improve state-of-the-art astrometry. Source coordinates for 268 sources were estimated at 24 GHz and for 131 sources at 43 GHz. The median formal uncertainties of right ascension and declination at 24 GHz are 0.08 and 0.15 mas, respectively. Median formal uncertainties at 43 GHz are 0.20 and 0.35 mas, respectively. Weighted root-mean-square differences between the 24 and 43 GHz positions and astrometric positions based on simultaneous 2.3 and 8.4 GHz Very Long Baseline Interferometry observations, such as the ICRF, are less than about 0.3 mas in both coordinates. With observations over five years we have achieved a precision at 24 GHz approaching that of the ICRF but unaccounted systematic errors limit the overall accuracy of the catalogs.

Lanyi, G. E.; Jacobs, C. S.; Naudet, C. J.; Sovers, O. J.; Zhang, L. D. [Jet Propulsion Laboratory, Caltech, 4800 Oak Grove Dr., Pasadena, CA 91109 (United States); Boboltz, D. A.; Fey, A. L. [U.S. Naval Observatory, 3450 Massachusetts Ave., NW, Washington, DC 20392-5420 (United States); Charlot, P. [Universite de Bordeaux, Observatoire Aquitain des Sciences de l'Univers, BP 89, 33271 Floirac Cedex (France); Fomalont, E. B. [National Radio Astronomy Observatory, 520 Edgemont Rd., Charlottesville, VA 22903 (United States); Geldzahler, B. J. [National Aeronautics and Space Administration, 300 E. St., SW, Washington, DC 20546 (United States); Gordon, D. [NVI Inc./NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Ma, C. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Romney, J. D. [National Radio Astronomy Observatory, P.O. Box O, Socorro, NM 87801 (United States)

2010-05-15T23:59:59.000Z

227

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

SciTech Connect (OSTI)

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

228

Radio observations of the gamma-ray quasar 0528+134: Superluminal motion and an extreme scattering event  

E-Print Network [OSTI]

We report on multifrequency radio observations made with the Effelsberg 100-m telescope, the IRAM 30-m telescope and the Green Bank Interferometer between 1992 and 1994 of the $\\gamma$-ray quasar 0528+134. We present a new VLBI based map of 0518+134 at 22 GHz with sub-mas angular resolution observed in November 1992, which shows a one-sided core jet structure of $\\sim$ 5 mas length. One component, seen also previously at 8.4 GHz & 22 GHz, shows apparent superluminal motion with $\\beta_{app}$=4.4$\\pm$1.7. In summer 1993 we observed a major outburst at all frequencies higher than a few GHz, which peaked a few months after a strong outburst in high energy $\\gamma$-rays and showed the canonical time evolution of a cooling and/or expanding electron distribution. Our data indicate that the outburst in the EGRET range originated very close to the central object of the AGN and that a remnant of this outburst moved further outward in the jet until it became optically thin at radio frequencies after a few months. During the flare in July 1993 we observed with the Effelsberg 100-m telescope an unusually strong decrease of the flux density by about 50% at 4.75 GHz and 10.55 GHz and slightly less at 2.695 GHz. This behaviour is also seen in the monitoring data at 2.25 GHz and 8.3 GHz taken with the Green Bank Interferometer (NRL-GBI). An extreme scattering event by a small dense plasma cloud in the line of sight is able to match the observed time lag in the lightcurves if we take into account the mas-structure of the source and different spectra of the components on the basis of their brightness in the VLBI maps.

M. Pohl; W. Reich; T. P. Krichbaum; K. Standke; S. Britzen; H. P. Reuter; P. Reich; R. Schlickeiser; R. L. Fiedler; E. B. Waltman; F. D. Ghigo; K. J. Johnston

1995-03-22T23:59:59.000Z

229

Rotor Design for High Pressure Magic Angle Spinning Nuclear Magnetic Resonance  

SciTech Connect (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 deg 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 V.F.; Hoyt, David W.; Rosso, Kevin M.; Sears, Jesse A.; Loring, John S.; Felmy, Andrew R.; Hu, Jian Z.

2013-01-01T23:59:59.000Z

230

An economic analysis of the welfare crisis in Texas  

E-Print Network [OSTI]

: The caseload data is in the Department of Public Idlf '*~AIR, RI1 d, f 6 f'. ly. 1'6 medical expenditures are reported in the Department's Annual 1'~lf *d "S. y fNd'1A. '. . Rpd'? tures" May 28, 1971, Kerr-Mill mas enacted in fiscal 1962. " *Estimated... finance issues has been a great help to me on numerous occasions. I am very gzateful to Mr, Thomas M Keel, Director of the Legislative Budget Board, for without his encouragement and support this thesis would never have been completed. I can never...

Ledbetter, Harry Laughlin

1972-01-01T23:59:59.000Z

231

Polychlorinated biphenyls in water, sediment and selected organisms of Galveston Bay, Texas: environmental levels and bioaccumulation  

E-Print Network [OSTI]

PGLYCKQBINATH3 BIPHEtKLS IN hATER, S~~BKtlT KiD SEIZCTED QRGMJIB&% OF VPAIGN BAY, ~z. ENVIEG~ I~S KG BIOACC21ULATIGN. A Thesis by RALPH ~ STARE'r ~i'tted to the Graduate College of TQMs ASH University in partial fulfillment of the requirement... for the degree of MAS~~ QF SCIENCE Play 1980 Major Subject: Biology POLYCHLORINATED BIPHENYLS IN WATER, SEDIMENT AND SELECTED ORGANISMS OF GALVESTON BAY, TEXAS. ENVIRONMENTAL LEVELS AND BIOACCUMULATION A Thesis RALPH GARNER STAHL, JR. Approved...

Stahl, Ralph Garner

1980-01-01T23:59:59.000Z

232

O Teatro Brasileiro na Dcada de Oitenta  

E-Print Network [OSTI]

-foi apresentada com estrondoso xito no somente no Brasil mas tambm em vrios festivais internacionais de teatro e em turnes pela Europa e Amricas. Sob a direo meticulosa de Antunes Filho, o Grupo Macunama conseguiu liberar a energia da rapsdia de Mrio... dcada de oitenta explica-se, ao menos em parte, pelas experincias dos que foram mais de perto atingidos pela censura da ditadura. Com a liberalizao poltica, Boal voltou ao Brasil pela primeira vez em oito anos para dar palestras e dirigir...

Albuquerque, Severino Joã o

1992-04-01T23:59:59.000Z

233

A Lightweight and Flexible Mobile Agent Platform Tailored to Management Applications  

E-Print Network [OSTI]

Mobile Agents (MAs) represent a distributed computing technology that promises to address the scalability problems of centralized network management. A critical issue that will affect the wider adoption of MA paradigm in management applications is the development of MA Platforms (MAPs) expressly oriented to distributed management. However, most of available platforms impose considerable burden on network and system resources and also lack of essential functionality. In this paper, we discuss the design considerations and implementation details of a complete MAP research prototype that sufficiently addresses all the aforementioned issues. Our MAP has been implemented in Java and tailored for network and systems management applications.

Gavalas, Damianos

2011-01-01T23:59:59.000Z

234

Variable-temperature solid-state NMR studies of iron(II) and iron(III) complexes  

E-Print Network [OSTI]

the first communication reporting the use of C CP/MAS NMR to observe paramagnetic solids directly. Zust as shift reagents had been used in solution-state NMR, selected paramagnetic lanthanide acetates exhibited paramagnetic shifts in the solid state... of the Fe(III) chloride salt yields the w-oxo-bis[porphine- iron(III)] dimer where the two iron centers are bridged via an oxygen. The synthesis, characterization and crystal structure of the metallo-porphyrin dimer w-oxo-bis[tetra- phenylporphineiron...

Shepard, Patricia Arlene

1989-01-01T23:59:59.000Z

235

Natural polymers as alternative consolidants for the preservation of waterlogged archaeological wood  

E-Print Network [OSTI]

by C-13 High-Resolution Solid- State CP-MAS NMR. Journal of Archaeological Science, 34:1670-1676. Bardet, M., Gerbaud, G., Doan, C., Giffard, M., Hediger, S., De Paepe, G. & Trn, Q.K. 2012. Dynamics Property Recovery of Archaeological-Wood Fibers... of signals displaying intensity in both the Mary Rose wood and natural polymer based consolidants were chosen for analysis as this allow us to look at the net effect of the molecular dynamics. The intense signal at 104 ppm, often assigned to the C1 carbon...

Walsh, Zarah; Jane?ek, Emma-Rose; Jones, Mark; Scherman, Oren A.

2014-01-01T23:59:59.000Z

236

Grupo fundamental e espacos de recobrimento, ver~ao 2011, Lista 2 Professor: H. Bursztyn  

E-Print Network [OSTI]

caminhos a, b, c, d : I X dados por: a(s) = F(s, 0), b(s) = F(1, s), c(s) = F(0, s), d(s) = F(1, s que o grupo fundamental de um grupo topol´ogico ´e abeliano. Dica: dados la¸cos a, b : I G com ponto base 1 G, use o problema 1 para F(s, t) = m(a(s), b(t))... Problema 3: Mostre que s~ao equivalentes

Bursztyn, Henrique

237

Single and Multiple Heteroatom Incorporation in MFI Zeolites  

E-Print Network [OSTI]

.6 (top) and Sn-MFI-c-13.2 (bottom) samples, where from top to bottom c = 15, 25, 50, 100 and 150 ...........................................................................129 5.3 Unit cell volume of as-made Sn-MFI samples as a function of the gel Sn/Si...-MFI-100-10.6, Silicalite-1 and SnO2. (Right) FT-IR spectra of as-made Sn-MFI-c-12 samples......................................................................141 5.12 29Si MAS NMR of as-made (left) and calcined (right) Sn-MFI-50-12 sample...

Garcia Vargas, Nataly

2012-11-05T23:59:59.000Z

238

Packing a Safe School Lunch (Spanish)  

E-Print Network [OSTI]

reproducir suficiente bacteria en dos horas para causar enfemedad. Algunos alimentos deben mantenerse fr?os (a 40 gra- dos F o menos) o calientes (a 140 grados F o mas). Estos son alimentos perecederos tales como carne, aves, mariscos, huevos y productos l...?cteos (incluyen- do el yogurt). Lo m?s importante para preparar una comida sana, es mantener fr?os los alimentos fr?os y caliente los alimentos calientes y mantener todo limpio. A continuaci?n, el por qu? y el c?mo. Para reproducirse, las bacterias que causan...

Van Laanen, Peggy

2001-10-22T23:59:59.000Z

239

Estimation of Nitric and Nitrous Nitrogen in Soils  

E-Print Network [OSTI]

, were found to check as well as could be expected with the zinc ferrous-sulphate methods, which include both nitrate and nitrite nitrogen. Some of the results obtained in the course of the investigation out- lined are here presented, together with a... in Series 1 mas 1.0 part per million on 7.7 parts per million, or about 12 per cect: the average difference of the 11 was 0.1 on 7.5 parts per million, or a little over one per cent. In Series 2, the maximum clifference was 3.3 parts per million on 25...

Fraps, G. S. (George Stronach); Sterges, A. J.

1931-01-01T23:59:59.000Z

240

The equity of property tax assessments on residential property in Bryan and College Station, Texas  

E-Print Network [OSTI]

Residential property type (single family detached, snltiplex, TH-C) Lot Size (square footage) Bedroans (actual number) Fence (yes or no) Fireplace (total number of) Garage Detached (number of stalls) Garage Attached (number of stalls) Car'port (double...THE ACUITY OF PROPERTY TAX ASSES~S ON RESIDENTIAL PROPERTY IN BRYAN AND COLLEGE STATION, TEXAS A Thesis by Submitted to the Graduate College of Texas A&M University in partial fuifi11ment of the requiranents for the degree of MAS~ OF SCIENCE...

Kelvey, William Granville

1986-01-01T23:59:59.000Z

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.


241

Man, machine, and synthesis in the essays of Ernesto Sabato: failing to breach the "line of despair"  

E-Print Network [OSTI]

those subjective values and concerns which form the core of what is t d' t' t' ly A . A t p t 't ' t~ll universo, La ciencia estricta--es decir, la ciencia matematizable--es ajena a todo lo que es mas valioso para un ser humano: sus emociones, sus... entre el mundo y el ser humano, en tiempos en que el ser humano parece encontrarse en el mundo corno un extranjero solitario y desamparado. Son tiempos en que se ha borrado una imagen del Universo, desapareciendo con ella la sensacion de seguridad que se...

Mayes, Rollin Merl

1990-01-01T23:59:59.000Z

242

Plan of organization  

E-Print Network [OSTI]

~!lr fund available. By recent enactment the appropriation ib placed at the disposal of tEe screral States, and the station1 are being organized. OBJECT OF THE STATIONS. The purpose for which the Agricultural Experiment 11 mas passed is clearly... in the mails free. THE EXPERIMENT STATIONS were placed under the supervision of the Boards of Directors of the Agricultural and Mechanical Colleges, not for the pur- pose of assisting the colleges, but because it was thought the fund would be most...

McInnis, Louis L. (Louis Lowry); Scott, T. M.; Gulley, F. A. (Frank Arthur)

1888-01-01T23:59:59.000Z

243

Transmutation of {sup 129}I Using an Accelerator-Driven System  

SciTech Connect (OSTI)

A conceptual blanket design for {sup 129}I transmutation is proposed for an accelerator-driven system (ADS) that is designed to transmute minor actinides (MAs). In this ADS, 250 kg/yr of MA and 56 kg/yr of iodine are simultaneously transmuted, and they correspond to the quantities generated from {approx}10 units of existing light water reactors. Furthermore, an introduction scenario and the benefit of iodine transmutation are studied for future introduction of fast breeder reactors. It is shown that the transmutation of iodine benefits the concept of underground disposal.

Nishihara, Kenji; Takano, Hideki [Japan Atomic Energy Research Institute (Japan)

2002-01-15T23:59:59.000Z

244

A solid-state nuclear magnetic resonance study of the reactions of propene on HY zeolite  

E-Print Network [OSTI]

, and condensation. The main objective of this study was to determine the reaction mechanism (including the observation of intermediates) for propane adsorbed on HY zeolite. C enriched propene was adsorbed on HY zeolite at room temperature, and it was observed..., as denoted by arrows C CP/MAS spectrum of propene-2- C 13 adsorbed on HY zeolite at room temperature 10 The polymerization reaction proposed in reference 13 for the adsorption of propene on HY zeolite The Bloch decay pulse sequence in NMR experiments...

Oshiro, Irene Sueko

1988-01-01T23:59:59.000Z

245

Subparsec-scale HI in the nucleus of NGC 4151  

E-Print Network [OSTI]

We present sensitive, high-resolution 21-cm VLBA+VLA observations of the radio jet and nuclear HI absorption in NGC 4151. The 25-mas (1.6-pc) resolution continuum image reveals a highly collimated radio jet, underlying the discrete components seen previously with MERLIN and the VLA. Spatially and kinematically complex HI absorption is detected against the whole 3-pc extent of the continuum component predicted by Ulvestad et al. to contain the AGN. Instead, we suggest the component against which the absorption is detected is part of the eastern counterjet, ruling it out as the location for the AGN.

C. G. Mundell; J. M. Wrobel; A. Pedlar; J. F. Gallimore

2000-12-11T23:59:59.000Z

246

The vascular flora of Robertson County, Texas  

E-Print Network [OSTI]

-ME VASCULAR 'LORA OF ROSERTSON CONNTY, T~S A Thesis by TMOMAS ZVNN STARSNCM Subm t-ed to the 9"aduar. e College of Texas AaM gn' ve. -sity ir. pa=t al u' f' ' ' . . er. e of rhe regu':emen =- for the deg=ee of MAS FR OF SCIENCE May l984 Ma...:or Subgect: 3ctany THE VASCULAR FLORA OF ROBERTSON COUNTY, TEXAS A Thesis THOMAS JUNN STARBUCX Approved as to style and content by: ugh D. Wzl on red E. Smemns (member) tephan L. Hatch (member) Merrmll H. Sweet (member) Walter M. Kemp (Head...

Starbuck, Thomas Junn

2012-06-07T23:59:59.000Z

247

A Situao Social da Mulher no Teatro de Consuelo de Castro e Leilah Assuno  

E-Print Network [OSTI]

SPRING 1976 13 A Situao Social de Mulher no Teatro de Consuelo de Castro e Leilah Assuno ALCIDES JOO DE BARROS A presena feminina em palcos brasileiros um acontecimento normal e at mesmo exigido pelo pblico j bastante acostumado a..., pois o fato em si nada significa do ponto de vista artstico. Na verdade, suas peas por si mesmas justificam um estudo que as coloque numa posio de relevncia, como se faria com qualquer autor de mrito. Mas o que realmente se faz digno de nota ...

Barros, Alcides J. de.

1976-04-01T23:59:59.000Z

248

Si m pa rele : 29 septembre 1991-14 octobre 1994  

E-Print Network [OSTI]

of Kansas Institute of Haitian Studies Occasional Papers Bryant C. Freeman, Ph.D. - Series Editor N 1 - Konstitisyon Repiblik Ayiti, 29 mas 1987. 1994. Pp. vi-106. Haitian-language version (official orthography) of the present Constitution... Peyi Dayiti. 1995. Pp. v-71. Haitian- language version of N 5, in Pressoir-Faublas orthography. Introduction in English. N 7 - Samuel G. Perkins, "On the Margin of Vesuvius11 : Sketches of St. Domingo, 1785-1793. 1995. Pp. vi-75. First-hand account...

1998-01-01T23:59:59.000Z

249

Overview of crop management strategy for greenhouse tomatoes with an emphasis on employee development  

E-Print Network [OSTI]

enfermedades con el deshoje bien hecho. PLANTAN00 (PLANTINt") Figure 24: perfect placement of the new transplants. Cuando plantamos los tomates, llegan cultivados en un bloque. Nosotros tenemos que poner el bloque encima de una almohada que contiene... material tal corno el coco para dar a las raizes mas espacio donde crecer. Tambien, ponemos una manguerita en cada planta?para dar agu y nutrientes. En el ejemplo en figura 24, el bloque estk puesto perfectamente, Hay una manguerlta en cada planta, y el...

Freeman, Christopher Neil

1999-01-01T23:59:59.000Z

250

Structure and formation mechanism of six-fold coordinated silicon in phosphosilicate glasses  

SciTech Connect (OSTI)

The local structure of sixfold oxygen coordinated silicon ({sup [6]}Si) in sodium phosphosilicate glasses has been investigated using MAS NMR spectroscopy and ab initio quantum-chemical techniques. It has been demonstrated that {sup [6]}Si is interconnected by six PO{sub 4} tetrahedral units by sharing only their corners, forming a nearly regular [SiO{sub 6/2}]{sup 2-} octahedral site. Alkali cations behave as charge compensators of the doubly charged {sup [6]}Si species and hence play an indispensable role in stabilizing the peculiar octahedral coordination in the glasses.

Miyabe, D.; Yoko, T. [Amorphous Materials Laboratory, Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Takahashi, M.; Tokuda, Y. [Amorphous Materials Laboratory, Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012 (Japan); Uchino, T. [Department of Chemistry, Faculty of Science, Kobe University, Nada, Kobe 657-8501 (Japan)

2005-05-01T23:59:59.000Z

251

Analysis of sub-surface towing of tendons and comparison of results using WINPOST and ORCAFLEX  

E-Print Network [OSTI]

dmpm or ~m Reheard tn Sbdh ~ Canvergenae: Mas Mht Msg. Or Mag. Of Neragarm Taienece Damphtg SRL Error SRL Change 30 0. 0001 1800 2000 tLOTO Speed (nua) Dhecthm (deg) 0. 00 0. 00 Stags DunNon Number (a) 0 9. 000 1 208dtO Tbne Slaps (s) hear... Outer 0. 00028 08100 Une Target Damping (% arhhmt): Axle( Sending Tomhn O. MOO 0. 0000 0. 0000 Nea Our(sac 2 (m): 0. 000 Water Densgy Varhdhrc Water Densh)r. Constant Density (isbn"3) 1. 02$ Seabed Type Flat Seabed Origin (m) Dhecgon Slaps...

Mendon, Perdoor Mukthi

2002-01-01T23:59:59.000Z

252

Recovery of minor actinides from spent fuel using TPEN-immobilized gels  

SciTech Connect (OSTI)

A series of separation experiments was performed in order to study the recovery process for minor actinides (MAs), such as americium (Am) and curium (Cm), from the actual spent fuel by using an extraction chromatographic technique. N,N,N',N'-tetrakis-(4-propenyloxy-2-pyridylmethyl) ethylenediamine (TPPEN) is an N,N,N',N'-tetrakis (2-pyridylmethyl) ethylenediamine (TPEN) analogue consisting of an incorporated pyridine ring that acts as not only a ligand but also as a site for polymerization and crosslinking of the gel. The TPPEN and N-isopropylacrylamide (NIPA) were dissolved into dimethylformamide (DMF, Wako Co., Ltd.) and a silica beads polymer, and then TTPEN was immobilized chemically in a polymer gel (so called TPEN-gel). Mixed oxide (MOX) fuel, which was highly irradiated up to 119 GWD/MTM in the experimental fast reactor Joyo, was used as a reference spent fuel. First, uranium (U) and plutonium (Pu) were separated from the irradiated fuel using an ion-exchange method, and then, the platinum group elements were removed by CMPO to leave a mixed solution of MAs and lanthanides. The 3 mol% TPPEN-gel was packed with as an extraction column (CV: 1 ml) and then rinsed by 0.1 M NaNO{sub 3}(pH 4.0) for pH adjustment. After washing the column by 0.01 M NaNO{sub 3} (pH 4.0), Eu was detected and the recovery rate reached 93%. The MAs were then recovered by changing the eluent to 0.01 M NaNO{sub 3} (pH 2.0), and the recovery rate of Am was 48 %. The 10 mol% TPPEN-gel was used to improve adsorption coefficient of Am and a condition of eluent temperature was changed in order to confirm the temperature swing effect on TPEN-gel for MA. More than 90% Eu was detected in the eluent after washing with 0.01 M NaNO{sub 3} (pH 3.5) at 5 Celsius degrees. Americium was backwardly detected and eluted continuously during the same condition. After removal of Eu, the eluent temperature was changed to 32 Celsius degrees, then Am was detected (pH 3.0). Finally remained Am could be stripped from TPPEN-gel by changing the pH of the eluent to 2.0. These results These results prove that the proposed recovery process for MAs is a potential candidate for future reprocessing methods based on the extraction chromatographic technique. (authors)

Koyama, S.; Suto, M.; Ohbayashi, H. [Oarai Research and Development Center, Japan Atomic Energy Agency, Oarai (Japan); Oaki, H. [Solutions Research Organization, Tokyo Institute of Technology, Tokyo (Japan); Takeshita, K. [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Tokyo (Japan)

2013-07-01T23:59:59.000Z

253

El concepto del honor en tres dramas de Calderon  

E-Print Network [OSTI]

principales del drama, con excepcion del 14 Infante Enrique, viven preocupados por el honor. Para ellos el honor es mas importante que el amor, la felicidad o hasta que la vide. En el primer ecto despues de haber cafdo el Infante Enrique de su caballo es... llevado a la quints de Dona Mencfa y Don Gutierre para recuperarse. Al recobrar el conocimiento, Enrique se da cuenta que esta en la casa de Mencfa, su antigua novia, y se enters de que ella se ha casado. Enrique decide entonces iree inmediatamente de...

Escabi, Maria Isabel

1978-01-01T23:59:59.000Z

254

Roberto Cossa habla del teatro  

E-Print Network [OSTI]

no vas a ver las puestas de tus piezas, pero vas al teatro a ver piezas que no son tuyas? S, voy al teatro bastante. Hay algn dramaturgo que te guste ms que otro, alguna predileccin? S, hay. Yo tengo una predileccin especial, quizs por... referentes son bien otra cosa. Es esto algo consciente por parte tuya o sali nada mas? No, uno est consciente sobre el lenguaje. Mi intento en su momento fue trabajar con todas mis imgenes de la Argentina de hoy, visto el mundo intelectual, el mundo...

Magnarelli, Sharon

1987-04-01T23:59:59.000Z

255

Solid State Nuclear Magnetic Resonance Investigation of Polymer Backbone Dynamics in Poly(Ethylene Oxide) Based Lithium and Sodium Polyether-ester-sulfonate Ionomers  

SciTech Connect (OSTI)

Polymer backbone dynamics of single ion conducting poly(ethylene oxide) (PEO)-based ionomer samples with low glass transition temperatures (Tg) have been investigated using solid-state nuclear magnetic resonance (NMR). Experiments detecting 13C with 1H decoupling under magic angle spinning (MAS) conditions identified the different components of the polymer backbone (PEO spacer and isophthalate groups) and their relative mobilities for a suite of lithium- and sodium-containing ionomer samples with varying cation contents. Variable temperature (203-373 K) 1H-13C cross-polarization MAS (CP-MAS) experiments also provided qualitative assessment of the differences in the motions of the polymer backbone components as a function of cation content and identity. Each of the main backbone components exhibit distinct motions, following the trends expected for motional characteristics based on earlier Quasi Elastic Neutron Scattering and 1H spin-lattice relaxation rate measurements. Previous 1H and 7Li spin-lattice relaxation measurements focused on both the polymer backbone and cation motion on the nanosecond timescale. The studies presented here assess the slower timescale motion of the polymer backbone allowing for a more comprehensive understanding of the polymer dynamics. The temperature dependences of 13C linewidths were used to both qualitatively and quantitatively examine the effects of cation content and identity on PEO spacer mobility. Variable contact time 1H-13C CP-MAS experiments were used to further assess the motions of the polymer backbone on the microsecond timescale. The motion of the PEO spacer, reported via the rate of magnetization transfer from 1H to 13C nuclei, becomes similar for T ? 1.1 Tg in all ionic samples, indicating that at similar elevated reduced temperatures the motions of the polymer backbones on the microsecond timescale become insensitive to ion interactions. These results present an improved picture, beyond those of previous findings, for the dependence of backbone dynamics on cation density (and here, cation identity as well) in these amorphous PEO-based ionomer systems.

Roach, David J. [Penn State Univ., State College, PA (United States). Dept. of Chemistry; Dou, Shichen [Penn State Univ., State College, PA (United States). Dept. of Materials Science and Engineering; Colby, Ralph H. [Penn State Univ., State College, PA (United States). Dept. of Materials Science and Engineering; Mueller, Karl T. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Penn State Univ., State College, PA (United States). Dept. of Chemistry

2013-05-21T23:59:59.000Z

256

Social Thought and Research, Volume 23, Number 1&2 (2000): Front Matter  

E-Print Network [OSTI]

to the above address. TABLE OF CONTENTS Vol. 23, No. 1&2 2000 ACKNOWLEDGMENTS FEATURE ARTICLE ON AMERICAN SOCIAL THOUGHT Robert J. Kent Dewey and the Project of Critical Social Theory ~ 1 Two EARLY AMERICAN MAsTERS: MEAD AND BLUMER George Herbert Mead Science... Vision in Sociology 199 Clifford L. Staples and William G. Staples Rereading Harry Braverman's LaborandMonopolY Capital After Twenty years 227 Jean Van Delinder Dance as Experience: Pragmatism and Classical Ballet 239 1 ~ I r I I ; J I . I ! SPECIAL...

2000-04-01T23:59:59.000Z

257

SPACE VELOCITIES OF SOUTHERN GLOBULAR CLUSTERS. VII. NGC 6397, NGC 6626 (M28), AND NGC 6656 (M22)  

SciTech Connect (OSTI)

We have measured the absolute proper motions of globular clusters NGC 6397, NGC 6626 (M22), and NGC 6656 (M28) as part of our ongoing Southern Proper-Motion Program. The reference system is the ICRS via Hipparcos stars for these three low-Galactic-latitude clusters. Formal errors range between {approx}0.3 and 0.7 mas yr{sup -1}. Notable is the result for NGC 6397, which differs by 2.5 mas yr{sup -1} from two Hubble Space Telescope determinations while agreeing with previous ground-based ones. We determine orbits for all three clusters in an axisymmetric and barred model of the Galaxy and discuss these in the context of globular-cluster formation. M22 is a well-known cluster with an iron abundance spread; such clusters are now believed to have formed in massive parent systems that can retain ejecta of core-collapsed supernovae. We find that the five currently accepted globular clusters with iron/calcium abundance spread show orbits unrelated to each other, thus suggesting at least five independent, massive progenitors that have contributed to the build-up of the Milky-Way halo.

Casetti-Dinescu, Dana I.; Girard, Terrence M.; Van Altena, William F. [Astronomy Department, Yale University, P.O. Box 208101, New Haven, CT 06520-8101 (United States); Jilkova, Lucie [Department of Theoretical Physics and Astrophysics, Faculty of Science, Masaryk University, Kotlarska 2, CZ-61137 Brno (Czech Republic); Podesta, Federico; Lopez, Carlos E., E-mail: dana.casetti@yale.edu, E-mail: terry.girard@yale.edu, E-mail: william.vanaltena@yale.edu, E-mail: jilkoval@physics.muni.cz [Universidad National de San Juan, Observatorio Astronomico ''Felix Aguilar'' and Yale Southern Observatory, Chimbas, 5413 San Juan (Argentina)

2013-08-01T23:59:59.000Z

258

THE CATALOG OF POSITIONS OF OPTICALLY BRIGHT EXTRAGALACTIC RADIO SOURCES OBRS-2  

SciTech Connect (OSTI)

Future space-borne astrometry missions, such as Gaia, will be able to determine the optical positions of hundreds of quasars with submilliarcsecond accuracies comparable to those achieved in radio by very long baseline interferometry (VLBI). Comparisons of coordinate systems from space-borne missions and VLBI will be very important, first for investigations of possible systematic errors and second for investigations of possible shifts between centroids of radio and optical emissions in active galactic nuclei. In order to make such a comparison more robust, a program for densification of the grid of radio sources detectable with both VLBI and Gaia was launched in 2006. Program sources are 398 quasars with declinations > - 10 Degree-Sign that are brighter than 18 mag at the V band. The first two observing campaigns were run in 2007-2008. In the third campaign, a set of 291 objects from that list was observed with the VLBA+EVN in 2010-2011 with the primary goal of producing their images with milliarcsecond resolution. In this paper, following the method of absolute astrometry, coordinates of observed sources have been derived with milliarcsecond accuracies from analysis of these observations. The catalog of positions of 295 target sources, estimates of their correlated flux densities at 2.2 and 8.4 GHz, and their images are presented. The accuracies of source coordinates are in a range of 2-200 mas, with a median of 3.2 mas.

Petrov, L., E-mail: Leonid.Petrov@lpetrov.net [Astrogeo Center, Falls Church, VA 22043 (United States)

2013-07-01T23:59:59.000Z

259

PROPER MOTIONS AND ORIGINS OF AXP 1E 2259+586 AND AXP 4U 0142+61  

SciTech Connect (OSTI)

Using high-resolution NIR images supported by laser guide star adaptive optics from the Keck II telescope from 2005 to 2012, we have measured the proper motions of two anomalous X-ray pulsars, AXP 1E 2259+586 and AXP 4U 0142+61. The proper motion of AXP 1E 2259+586 in the sky frame is ({mu}{sub {alpha}}, {mu}{sub {delta}}) = (- 6.4 {+-} 0.6, -2.3 {+-} 0.6) mas yr{sup -1} and that of AXP 4U 0142+61 is ({mu}{sub {alpha}}, {mu}{sub {delta}}) = (- 4.1 {+-} 1, 1.9 {+-} 1) mas yr{sup -1}. After correcting for the velocity of the progenitors, we calculate the tangential ejection velocities of the magnetars to be 157 {+-} 17 km s{sup -1} and 102 {+-} 26 km s{sup -1} respectively. The proper motion vector of AXP 1E 2259+586 is directed away from the putative center of the supernova remnant CTB 109 that has long been proposed to be associated with AXP 1E 2259+586. This is significant evidence for linking the pulsar with CTB 109. We comment on the possible movement of CTB 109 after the explosion. We narrow the search cone for the birthsite or remnant of AXP 4U 0142+61 to an opening angle of 24 Degree-Sign . However, we are unable to find any suitable association.

Tendulkar, Shriharsh P.; Kulkarni, Shrinivas R. [California Institute of Technology, 1200 E California Blvd, MC 249-17, Pasadena, CA 91125 (United States); Cameron, P. Brian, E-mail: spt@astro.caltech.edu, E-mail: srk@astro.caltech.edu, E-mail: pbc@astro.caltech.edu [Aerospace Corporation, 15049 Conference Center Drive, Chantilly, VA 20151-3824 (United States)

2013-07-20T23:59:59.000Z

260

Connection between inner jet kinematics and broadband flux variability in the BL Lac object S5 0716+714  

E-Print Network [OSTI]

We present a high-frequency very long baseline interferometry (VLBI) kinematical study of the BL Lac object S5 0716+714 over the time period of September 2008 to October 2010. The aim of the study is to investigate the relation of the jet kinematics to the observed broadband flux variability. We find significant non-radial motions in the jet outflow of the source. In the radial direction, the highest measured apparent speed is \\sim37 c, which is exceptionally high, especially for a BL Lac object. Patterns in the jet flow reveal a roughly stationary feature \\sim0.15 mas downstream of the core. The long-term fits to the component trajectories reveal acceleration in the sub-mas region of the jet. The measured brightness temperature, T_{B}, follows a continuous trend of decline with distance, T_B \\propto r_{jet}^{-(2.36\\pm0.41)}, which suggests a gradient in Doppler factor along the jet axis. Our analysis suggest that a moving disturbance (or a shock wave) from the base of the jet produces the high-energy (optica...

Rani, B; Marscher, A P; Hodgson, J A; Fuhrmann, L; Angelakis, E; Britzen, S; Zensus, J A

2015-01-01T23:59:59.000Z

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261

First-light LBT nulling interferometric observations: warm exozodiacal dust resolved within a few AU of eta Corvi  

E-Print Network [OSTI]

We report on the first nulling interferometric observations with the Large Binocular Telescope Interferometer (LBTI), resolving the N' band (9.81 - 12.41 um) emission around the nearby main-sequence star eta Crv (F2V, 1-2 Gyr). The measured source null depth amounts to 4.40% +/- 0.35% over a field-of-view of 140 mas in radius (~2.6\\,AU at the distance of eta Corvi) and shows no significant variation over 35{\\deg} of sky rotation. This relatively low null is unexpected given the total disk to star flux ratio measured by Spitzer/IRS (~23% across the N' band), suggesting that a significant fraction of the dust lies within the central nulled response of the LBTI (79 mas or 1.4 AU). Modeling of the warm disk shows that it cannot resemble a scaled version of the Solar zodiacal cloud, unless it is almost perpendicular to the outer disk imaged by Herschel. It is more likely that the inner and outer disks are coplanar and the warm dust is located at a distance of 0.5-1.0 AU, significantly closer than previously predic...

Defrre, D; Skemer, A J; Kennedy, G M; Bailey, V P; Hoffmann, W F; Mennesson, B; Millan-Gabet, R; Danchi, W C; Absil, O; Arbo, P; Beichman, C; Brusa, G; Bryden, G; Downey, E C; Durney, O; Esposito, S; Gaspar, A; Grenz, P; Haniff, C; Hill, J M; Lebreton, J; Leisenring, J M; Males, J R; Marion, L; McMahon, T J; Montoya, M; Morzinski, K M; Pinna, E; Puglisi, A; Rieke, G; Roberge, A; Serabyn, E; Sosa, R; Stapeldfeldt, K; Su, K; Vaitheeswaran, V; Vaz, A; Weinberger, A J; Wyatt, M C

2015-01-01T23:59:59.000Z

262

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 published values for the distance and mean radius show excellent agreement, particularly when a common scaling factor from observed radial velocity to pulsation velocity of the stellar atmosphere (the p-factor) is used.

J. Davis; A. P. Jacob; J. G. Robertson; M. J. Ireland; J. R. North; W. J. Tango; P. G. Tuthill

2008-12-28T23:59:59.000Z

263

The EBR-II X501 Minor Actinide Burning Experiment  

SciTech Connect (OSTI)

The X501 experiment was conducted in EBR-II as part of the IFR (Integral Fast Reactor) program to demonstrate minor actinide burning through the use of a homogeneous recycle scheme. The X501 subassembly contained two metallic fuel elements loaded with relatively small quantities of americium and neptunium. Interest in the behavior of minor actinides (MA) during fuel irradiation has prompted further examination of existing X501 data, and generation of new data where needed in support of the U.S. waste transmutation effort. The X501 experiment is one of the few minor actinide-bearing fuel irradiation tests conducted worldwide and knowledge can be gained by understanding the changes in fuel behavior due to addition of MAs. Of primary interest are the affect of the MAs on fuel-cladding-chemical-interaction, and the redistribution behavior of americium. The quantity of helium gas release from the fuel and any effects of helium on fuel performance are also of interest. It must be stressed that information presented at this time is based on the limited PIE conducted in 1995-1996, and currently represents a set of observations rather than a complete understanding of fuel behavior. This paper provides a summary of the X501 fabrication, characterization, irradiation, and post irradiation examination.

M. K. Meyer; S. L. Hayes; W. J. Carmack; H. Tsai

2009-07-01T23:59:59.000Z

264

The EBR-II X501 Minor Actinide Burning Experiment  

SciTech Connect (OSTI)

The X501 experiment was conducted in EBR-II as part of the IFR (Integral Fast Reactor) program to demonstrate minor actinide burning through the use of a homogeneous recycle scheme. The X501 subassembly contained two metallic fuel elements loaded with relatively small quantities of americium and neptunium. Interest in the behavior of minor actinides (MA) during fuel irradiation has prompted further examination of existing X501 data, and generation of new data where needed in support of the U.S. waste transmutation effort. The X501 experiment is one of the few minor actinide-bearing fuel irradiation tests conducted worldwide and knowledge can be gained by understanding the changes in fuel behavior due to addition of MAs. Of primary interest are the affect of the MAs on fuel-cladding-chemical-interaction, and the redistribution behavior of americium. The quantity of helium gas release from the fuel and any effects of helium on fuel performance are also of interest. It must be stressed that information presented at this time is based on the limited PIE conducted in 1995-1996, and currently represents a set of observations rather than a complete understanding of fuel behavior.

Jon Carmack; S. L. Hayes; M. K. Meyer; H. Tsai

2008-06-01T23:59:59.000Z

265

A radio-map of the colliding winds in the very massive binary system HD 93129A  

E-Print Network [OSTI]

Radio observations are an effective tool to discover particle acceleration regions in colliding-wind binaries, through detection of synchrotron radiation; these regions are natural laboratories for the study of relativistic particles. Wind-collision region (WCR) models can reproduce the radio continuum spectra of massive binaries that contain both thermal and non-thermal radio emission; however, key constraints for models come from high-resolution imaging. Only five WCRs have been resolved to date at radio frequencies at milliarcsec (mas) angular scales. The source HD 93129A, prototype of the very few known O2 I stars, is a promising target for study: recently, a second massive, early-type star about 50 mas away was discovered, and a non-thermal radio source detected in the region. Preliminary long-baseline array data suggest that a significant fraction of the radio emission from the system comes from a putative WCR. We sought evidence that HD 93129A is a massive binary system with colliding stellar winds tha...

Benaglia, Paula; Moldon, Javier; Nelan, Ed; De Becker, Michael; Dougherty, Sean M; Koribalski, Baerbel

2015-01-01T23:59:59.000Z

266

Validation of Minor Actinide Cross Sections by Studying Samples Irradiated for 492 Days at the Dounreay Prototype Fast Reactor - II: Burnup Calculations  

SciTech Connect (OSTI)

To evaluate neutron cross-section data of minor actinides (MAs), separated actinide samples and dosimetry samples were irradiated at the Dounreay Prototype Fast Reactor for 492 effective full-power days. Irradiated samples were analyzed both at Oak Ridge National Laboratory and at Japan Atomic Energy Research Institute (JAERI). This independent duplication has resulted in the generation of reliable radiochemical analysis data. Based on the burnup calculations of major actinide ({sup 235}U and {sup 239}Pu) and dosimetry samples, the neutron flux distribution and the flux level were adjusted at the locations where MA samples were irradiated. The burnup calculations were carried out for MAs using the determined flux distribution and flux level. The calculated results were compared with the experimental data. A brief description of sample preparation and irradiation and a detailed discussion of radiochemical analysis at JAERI are given in a companion paper. The current paper discusses the burnup calculations and the validation of MA cross-section data in evaluated nuclear data libraries.

Tsujimoto, K. [Japan Atomic Energy Research Institute (Japan); Kohno, N. [Japan Atomic Energy Research Institute (Japan); Shinohara, N. [Japan Atomic Energy Research Institute (Japan); Sakurai, T. [Japan Atomic Energy Research Institute (Japan); Nakahara, Y. [Japan Atomic Energy Research Institute (Japan); Mukaiyama, T. [Japan Atomic Energy Research Institute (Japan); Raman, S. [Oak Ridge National Laboratory (United States)

2003-06-15T23:59:59.000Z

267

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

SciTech Connect (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

268

Radio Continuum Observations of the Galactic Center: Photoevaporative Proplyd-like Objects near Sgr A*  

E-Print Network [OSTI]

We present radio images within 30$''$ of Sgr A* based on recent VLA observations at 34 GHz with 7.8 microJy sensitivity and resolution $\\sim88\\times46$ milliarcseconds (mas). We report 44 partially resolved compact sources clustered in two regions in the E arm of ionized gas that orbits Sgr A*. These sources have size scales ranging between ~50 and 200 mas (400 to 1600 AUs), and a bow-shock appearance facing the direction of Sgr A*. Unlike the bow-shock sources previously identified in the near-IR but associated with massive stars, these 34 GHz sources do not appear to have near-IR counterparts at 3.8 $\\mu$m. We interpret these sources as a candidate population of photoevaporative protoplanetary disks (proplyds) that are associated with newly formed low mass stars with mass loss rates ~10^{-7} - 10^{-6} solar mass per year and are located at the edge of a molecular cloud outlined by ionized gas. The disks are externally illuminated by strong Lyman continuum radiation from the ~100 OB and WR massive stars dist...

Yusef-Zadeh, F; Wardle, M; Cotton, W; Schdel, R; Royster, M J

2015-01-01T23:59:59.000Z

269

Composition, Mineralogy, and Porosity of Multiple Asteroid Systems from Visible and Near-infrared Spectral Data  

E-Print Network [OSTI]

We provide a taxonomic and compositional characterization of Multiple Asteroid Systems (MASs) located in the main belt (MB) using visible and near-infrared (0.45-2.5 um) spectral data of 42 MB MASs. The mineralogical analysis is applied to determine meteorite analogs for the MASs, which, in turn, are applied to the MAS density measurements of Marchis et al. (2012) to estimate the system porosity. The macroporosities are used to evaluate the primary MAS formation hypotheses. The visible observing campaign includes 25 MASs obtained using the SOAR telescope with the Goodman High Throughput Spectrometer. The infrared observing campaign includes 34 MASs obtained using the NASA IRTF with the SpeX spectragraph. The MASs are classified using the Bus-DeMeo taxonomic system. We perform a NIR spectral band parameter analysis using a new analysis routine, the Spectral Analysis Routine for Asteroids (SARA). The SARA routine determines band centers, areas, and depths by utilizing the diagnostic absorption features near 1- ...

Lindsay, Sean S; Emery, Joshua P; Enriquez, J Emilio; Assafin, Marcelo

2014-01-01T23:59:59.000Z

270

Indirectly detected chemical shift correlation NMR spectroscopy in solids under fast magic angle spinning  

SciTech Connect (OSTI)

The development of fast magic angle spinning (MAS) opened up an opportunity for the indirect detection of insensitive low-{gamma} nuclei (e.g., {sup 13}C and {sup 15}N) via the sensitive high-{gamma} nuclei (e.g., {sup 1}H and {sup 19}F) in solid-state NMR, with advanced sensitivity and resolution. In this thesis, new methodology utilizing fast MAS is presented, including through-bond indirectly detected heteronuclear correlation (HETCOR) spectroscopy, which is assisted by multiple RF pulse sequences for {sup 1}H-{sup 1}H homonuclear decoupling. Also presented is a simple new strategy for optimization of {sup 1}H-{sup 1}H homonuclear decoupling. As applications, various classes of materials, such as catalytic nanoscale materials, biomolecules, and organic complexes, are studied by combining indirect detection and other one-dimensional (1D) and two-dimensional (2D) NMR techniques. Indirectly detected through-bond HETCOR spectroscopy utilizing refocused INEPT (INEPTR) mixing was developed under fast MAS (Chapter 2). The time performance of this approach in {sup 1}H detected 2D {sup 1}H{l_brace}{sup 13}C{r_brace} spectra was significantly improved, by a factor of almost 10, compared to the traditional {sup 13}C detected experiments, as demonstrated by measuring naturally abundant organic-inorganic mesoporous hybrid materials. The through-bond scheme was demonstrated as a new analytical tool, which provides complementary structural information in solid-state systems in addition to through-space correlation. To further benefit the sensitivity of the INEPT transfer in rigid solids, the combined rotation and multiple-pulse spectroscopy (CRAMPS) was implemented for homonuclear {sup 1}H decoupling under fast MAS (Chapter 3). Several decoupling schemes (PMLG5{sub m}{sup {bar x}}, PMLG5{sub mm}{sup {bar x}x} and SAM3) were analyzed to maximize the performance of through-bond transfer based on decoupling efficiency as well as scaling factors. Indirect detection with assistance of PMLG{sub m}{sup {bar x}} during INEPTR transfer proved to offer the highest sensitivity gains of 3-10. In addition, the CRAMPS sequence was applied under fast MAS to increase the {sup 1}H resolution during t{sub 1} evolution in the traditional, {sup 13}C detected HETCOR scheme. Two naturally abundant solids, tripeptide N-formyl-L-methionyl-L-leucyl-L-phenylalanine (f-MLF-OH) and brown coal, with well ordered and highly disordered structures, respectively, are studied to confirm the capabilities of these techniques. Concomitantly, a simple optimization of {sup 1}H homonuclear dipolar decoupling at MAS rates exceeding 10 kHz was developed (Chapter 4). The fine-tuned decoupling efficiency can be obtained by minimizing the signal loss due to transverse relaxation in a simple spin-echo experiment, using directly the sample of interest. The excellent agreement between observed decoupling pattern and earlier theoretical predictions confirmed the utility of this strategy. The properties of naturally abundant surface-bound fluorocarbon groups in mesoporous silica nanoparticles (MSNs) were investigated by the above-mentioned multidimensional solid-state NMR experiments and theoretical modeling (Chapter 5). Two conformations of (pentafluorophenyl)propyl groups (abbreviated as PFP) were determined as PFP-prone and PFP-upright, whose aromatic rings are located above the siloxane bridges and in roughly upright position, respectively. Several 1D and 2D NMR techniques were implemented in the characterizations, including indirectly detected {sup 1}H{l_brace}{sup 13}C{r_brace} and {sup 19}F{l_brace}{sup 13}C{r_brace} 2D HETCOR, Carr-Purcell-Meiboom-Gill (CPMG) assisted {sup 29}Si direct polarization and {sup 29}Si{sup 19}F 2D experiments, 2D double-quantum (DQ) {sup 19}F MAS NMR spectra and spin-echo measurements. Furthermore, conformational details of two types of PFP were confirmed by theoretical calculation, operated by Dr. Takeshi Kobayashi. Finally, the arrangement of two surfactants, cetyltrimetylammoium bromide (CTAB) and cetylpyridinium bromide (CPB), mixed inside th

Mao, Kanmi

2011-08-15T23:59:59.000Z

271

Structural study of VO {sub x} doped aluminium fluoride and aluminium oxide catalysts  

SciTech Connect (OSTI)

The structural properties of vanadium doped aluminium oxyfluorides and aluminium oxides, prepared by a modified sol-gel synthesis route, were thoroughly investigated. The influence of the preparation technique and the calcination temperature on the coordination of vanadium, aluminium and fluorine was analysed by different spectroscopic methods such as Raman, MAS NMR and ESR spectroscopy. In all samples calcined at low temperatures (350 deg. C), vanadium coexists in two oxidation states V{sup IV} and V{sup V}, with V{sup IV} as dominating species in the vanadium doped aluminium oxyfluorides. In the fluoride containing solids aluminium as well as vanadium are coordinated by fluorine and oxygen. Thermal annealing of 800 deg. C leads to an extensive reorganisation of the original matrices and to the oxidation of V{sup IV} to V{sup V} in both systems. - Graphical abstract: Structure model for VO {sub x} doped aluminium oxide.

Scheurell, Kerstin [Institute of Chemistry, Humboldt University of Berlin, Brook-Taylor-Street 2, Berlin D-12489 (Germany); Scholz, Gudrun [Institute of Chemistry, Humboldt University of Berlin, Brook-Taylor-Street 2, Berlin D-12489 (Germany); Kemnitz, Erhard [Institute of Chemistry, Humboldt University of Berlin, Brook-Taylor-Street 2, Berlin D-12489 (Germany)], E-mail: erhard.kemnitz@chemie.hu-berlin.de

2007-02-15T23:59:59.000Z

272

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 Clnet; Daniel Rouan; Damien Gratadour; Olivier Marco; Pierre Lna; Nancy Ageorges; Eric Gendron

2005-07-05T23:59:59.000Z

273

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

SciTech Connect (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

274

Demineralization of petroleum cokes and fly ash samples obtained from the upgrading of Athabasca oil sands bitumen  

SciTech Connect (OSTI)

Ash reduction of the cokes and fly ash samples derived from the Athabasca oil sands bitumen was attempted by dissolving the mineral matter in acids. The samples used for this investigation included Syncrude fluid coking coke, Suncor delayed coking coke and the two fly ash samples obtained from the combustion of these cokes. All samples were analyzed for C,H,N,O, and S before and after acid demineralization and the analyses results compared. Further, the ash from the samples before and after acid demineralization was analyzed for silica, alumina, iron titanium, nickel and vanadium to assess the acid leaching of these elements. CP/MAS, /sup 13/C NMR spectroscopic study of the demineralized coke and fly ash samples was also attempted.

Majid, A.; Ratcliffe, C.I.; Ripmeester, J.A. (National Research Council of Canada, Ottawa, ON (Canada). Div. of Chemistry)

1989-01-01T23:59:59.000Z

275

A universal electromagnetic energy conversion adapter based on a metamaterial absorber  

E-Print Network [OSTI]

On the heels of metamaterial absorbers (MAs) which produce near perfect electromagnetic (EM) absorption and emission, we propose a universal electromagnetic energy conversion adapter (UEECA) based on MA. By choosing the appropriate energy converting sensors, the UEECA is able to achieve near 100% signal transfer ratio between EM energy and various forms of energy such as thermal, DC electric, or higher harmonic EM energy. The inherited subwavelength dimension and the EM field intensity enhancement can further empower UEECA in many critical applications such as energy harvesting, solar cell, and nonlinear optics. The principle of UEECA is understood with a transmission line model, which further provides a design strategy that can incorporate a variety of energy conversion devices. The concept is experimentally validated at a microwave frequency with a signal transfer ratio of 96% by choosing an RF diode as the energy converting sensor.

Xie, Yunsong; Wilson, Jeffrey D; Simons, Rainee N; Chen, Yunpeng; Xiao, John Q

2013-01-01T23:59:59.000Z

276

A Dickensian Christmas  

E-Print Network [OSTI]

;#1;#1;#1;#1;#1;#1;#1;#1;#1;#1;#1;#1;#1;#1;#1;#1;#1;#1;#1;#1;#1;#1;#1;#1; 5 #1;#1;#1;#1;#1;#1;#1;#1;#1;#1;#1;#1;#1;#1;#1;#1;#1;#1;#1;#1;#1; BENE DICTUM: A DICKENSIAN CHRISTMAS by M. FAE GLASGOW SHOPPING DAYS or DOYLE THE COPPER FELT UP balloons, red... Christmas A Dicken- sian Christmas A Dickensian Christ- mas A Dickensian #1; #1; #1; #1; #1;#1; #1; #1; #1; #1; #1; #1; #1; #1; #1;#1; BENE DICTUM #1; A DICKENSIAN CHRISTMAS by M. FAE GLASGOW #1; BENE DICTUM #1; A DICKENSIAN CHRISTMAS by M...

Glasgow, M.F.

1992-01-01T23:59:59.000Z

277

Aging Studies of Filled and Unfilled VCE  

SciTech Connect (OSTI)

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

278

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

SciTech Connect (OSTI)

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

279

Proper Motion Objects in the Hubble Deep Field  

E-Print Network [OSTI]

Using the deepest and finest resolution images of the Universe acquired with the Hubble Space Telescope and a similar image taken 7 years later for the Great Observatories Origins Deep Survey, we have derived proper motions for the point sources in the Hubble Deep Field--North. Two faint blue objects,HDF2234 and HDF3072, are found to display significant proper motion, 10.0 $\\pm$ 2.5 and 15.5 $\\pm$ 3.8 mas yr$^{-1}$. Photometric distances and tangential velocities for these stars are consistent with disk white dwarfs located at $\\sim$ 500 pc. The faint blue objects analyzed by Ibata et al. (1999) and Mendez & Minniti (2000) do not show any significant proper motion; they are not halo white dwarfs and they do not contribute to the Galactic dark matter. These objects are likely to be distant AGN.

M. Kilic; Ted von Hippel; R. A. Mendez; D. E. Winget

2004-03-26T23:59:59.000Z

280

Astrometry of the stellar image of U Her amplified by the circumstellar 22 GHz water masers  

E-Print Network [OSTI]

The 22 GHz H_2O masers in the circumstellar envelope of the Mira variable star U Her have been observed with MERLIN using a phase referencing technique to determine accurate astrometric positions. The positions were compared with the optical positions obtained with the Hipparcos satellite to an accuracy of 18 mas. The absolute radio position of the brightest H_2O maser spot is found to match the optical position, indicating that this spot is the stellar image amplified by the maser screen in front of it. The occurrence of an amplified image in the 22 GHz maser can be used to accurately determine the positions of the H_2O with respect to the star as well as with respect to the SiO and OH masers. Our observations seem to indicate that the star is not in the centre of the distribution of maser spots, which has been interpreted as a ring.

W. H. T. Vlemmings; H. J. van Langevelde; P. J. Diamond

2002-08-09T23:59:59.000Z

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281

Synthesis of acid-base bifunctional mesoporous materials by oxidation and thermolysis  

SciTech Connect (OSTI)

Graphical abstract: A novel and efficient method has been developed for the synthesis of acid-base bifunctional catalyst. The obtained sample of SO{sub 3}H-MCM-41-NH{sub 2} containing amine and sulfonic acids exhibits excellent catalytic activity in aldol condensation reaction. Research highlights: {yields} Synthesize acid-base bifunctional mesoporous materials SO{sub 3}H-MCM-41-NH{sub 2}. {yields} Oxidation and then thermolysis to generate acidic site and basic site. {yields} Exhibit good catalytic performance in aldol condensation reaction between acetone and various aldehydes. -- Abstract: A novel and efficient method has been developed for the synthesis of acid-base bifunctional catalyst SO{sub 3}H-MCM-41-NH{sub 2}. This method was achieved by co-condensation of tetraethylorthosilicate (TEOS), 3-mercaptopropyltrimethoxysilane (MPTMS) and (3-triethoxysilylpropyl) carbamicacid-1-methylcyclohexylester (3TAME) in the presence of cetyltrimethylammonium bromide (CTAB), followed by oxidation and then thermolysis to generate acidic site and basic site. X-ray diffraction (XRD) and transmission electron micrographs (TEM) show that the resultant materials keep mesoporous structure. Thermogravimetric analysis (TGA), X-ray photoelectron spectra (XPS), back titration, solid-state {sup 13}C CP/MAS NMR and solid-state {sup 29}Si MAS NMR confirm that the organosiloxanes were condensed as a part of the silica framework. The bifunctional sample (SO{sub 3}H-MCM-41-NH{sub 2}) containing amine and sulfonic acids exhibits excellent acid-basic properties, which make it possess high activity in aldol condensation reaction between acetone and various aldehydes.

Yu, Xiaofang [College of Chemistry, Jilin University, Jiefang Road 2519, Changchun 130023 (China)] [College of Chemistry, Jilin University, Jiefang Road 2519, Changchun 130023 (China); Zou, Yongcun [State Key Laboratory of Inoranic Synthesis and Preparative Chemistryg, College of Chemistry, Jilin University, Changchun 130012 (China)] [State Key Laboratory of Inoranic Synthesis and Preparative Chemistryg, College of Chemistry, Jilin University, Changchun 130012 (China); Wu, Shujie; Liu, Heng [College of Chemistry, Jilin University, Jiefang Road 2519, Changchun 130023 (China)] [College of Chemistry, Jilin University, Jiefang Road 2519, Changchun 130023 (China); Guan, Jingqi, E-mail: guanjq@jlu.edu.cn [College of Chemistry, Jilin University, Jiefang Road 2519, Changchun 130023 (China)] [College of Chemistry, Jilin University, Jiefang Road 2519, Changchun 130023 (China); Kan, Qiubin, E-mail: qkan@jlu.edu.cn [College of Chemistry, Jilin University, Jiefang Road 2519, Changchun 130023 (China)] [College of Chemistry, Jilin University, Jiefang Road 2519, Changchun 130023 (China)

2011-06-15T23:59:59.000Z

282

Synthesis, characterization and catalytic activity of acid-base bifunctional materials through protection of amino groups  

SciTech Connect (OSTI)

Graphical abstract: Acid-base bifunctional mesoporous material SO{sub 3}H-SBA-15-NH{sub 2} was successfully synthesized under low acidic medium through protection of amino groups. Highlights: Black-Right-Pointing-Pointer The acid-base bifunctional material SO{sub 3}H-SBA-15-NH{sub 2} was successfully synthesized through protection of amino groups. Black-Right-Pointing-Pointer The obtained bifunctional material was tested for aldol condensation. Black-Right-Pointing-Pointer The SO{sub 3}H-SBA-15-NH{sub 2} catalyst containing amine and sulfonic acid groups exhibited excellent acid-basic properties. -- Abstract: Acid-base bifunctional mesoporous material SO{sub 3}H-SBA-15-NH{sub 2} was successfully synthesized under low acidic medium through protection of amino groups. X-ray diffraction (XRD), N{sub 2} adsorption-desorption, transmission electron micrographs (TEM), back titration, {sup 13}C magic-angle spinning (MAS) NMR and {sup 29}Si magic-angle spinning (MAS) NMR were employed to characterize the synthesized materials. The obtained bifunctional material was tested for aldol condensation reaction between acetone and 4-nitrobenzaldehyde. Compared with monofunctional catalysts of SO{sub 3}H-SBA-15 and SBA-15-NH{sub 2}, the bifunctional sample of SO{sub 3}H-SBA-15-NH{sub 2} containing amine and sulfonic acid groups exhibited excellent acid-basic properties, which make it possess high activity for the aldol condensation.

Shao, Yanqiu [College of Chemistry, Jilin University, Changchun 130023 (China) [College of Chemistry, Jilin University, Changchun 130023 (China); College of Chemistry, Mudanjiang Normal University, Mudanjiang 157012 (China); Liu, Heng; Yu, Xiaofang [College of Chemistry, Jilin University, Changchun 130023 (China)] [College of Chemistry, Jilin University, Changchun 130023 (China); Guan, Jingqi, E-mail: guanjq@jlu.edu.cn [College of Chemistry, Jilin University, Changchun 130023 (China)] [College of Chemistry, Jilin University, Changchun 130023 (China); Kan, Qiubin, E-mail: qkan@mail.jlu.edu.cn [College of Chemistry, Jilin University, Changchun 130023 (China)] [College of Chemistry, Jilin University, Changchun 130023 (China)

2012-03-15T23:59:59.000Z

283

Solid-state Structural Characterization of a Rigid Framework of Lacunary Heteropolyniobates  

SciTech Connect (OSTI)

In our ongoing investigations of heteropolyniobate chemistry, a phase featuring decorated, A-type trivacant {alpha}-Keggin ions linked by their charge-balancing sodium cations has been isolated and structurally characterized. This is the first heteropolyniobate reported that has a true lacunary structure type. Na{sub 15}[(PO{sub 2}){sub 3}PNb{sub 9}O{sub 34}]{center_dot}22H{sub 2}O (1) [triclinic space group P{bar 1} (No. 2); a = 12.242 (2) Angstroms, b = 12.291 (3) Angstroms, c = 22.056 (4) Angstroms; {alpha}= 93.12 (3), {beta}= 99.78 (3), {gamma}= 119.84 (3); Z = 4, V = 2799.2 (10) Angstroms{sup 3}] is composed of bilayers of the heteropolyanions alternating with layers of hydrated Na{sup +} cations. Sodium cations also bridge the clusters within their layers through Na-Ot-Nb, Na-Ob-Nb2, and Na-Ot-P bonds (t = terminal and b = bridging). This phase is poorly soluble in water, suggesting that it is more characteristic of a framework of linked heteropolyanions rather than a water-soluble heteropolyanion salt. Two-dimensional solid-state {sup 23}Na multiple-quantum magic angle spinning (MAS) NMR of 1 reveals five distinctive chemical and structural environments for sodium, which agrees with the crystallographic data. The {sup 23}Na and {sup 1}H MAS NMR studies further illustrate the rigid and immobile nature of this framework of cations and anions.

Nyman,M.; Celestian, A.; Holland, G.; Alam, T.; Parise, J.

2006-01-01T23:59:59.000Z

284

High-Resolution NMR of Quadrupolar Nuclei in the Solid State  

SciTech Connect (OSTI)

This dissertation describes recent developments in solid state nuclear magnetic resonance (NMR), for the most part involving the use of dynamic-angle spinning (DAS) NMR to study quadrupolar nuclei. Chapter 1 introduces some of the basic concepts and theory that will be referred to in later chapters, such as the density operator, product operators, rotations, coherence transfer pathways, phase cycling, and the various nuclear spin interactions, including the quadrupolar interaction. Chapter 2 describes the theory behind motional averaging experiments, including DAS, which is a technique where a sample is spun sequentially about two axis oriented at different angles with respect to the external magnetic field such that the chemical shift and quadrupolar anisotropy are averaged to zero. Work done on various rubidium-87 salts is presented as a demonstration of DAS. Chapter 3 explains how to remove sidebands from DAS and magic-angle spinning (MAS) experiments, which result from the time-dependence of the Hamiltonian under sample spinning conditions, using rotor-synchronized {pi}-pulses. Data from these experiments, known as DAH-180 and MAH-180, respectively, are presented for both rubidium and lead salts. In addition, the applicability of this technique to double rotation (DOR) experiments is discussed. Chapter 4 concerns the addition of cross-polarization to DAS (CPDAS). The theory behind spin locking and cross polarizing quadrupolar nuclei is explained and a method of avoiding the resulting problems by performing cross polarization at 0{sup o} (parallel) with respect to the magnetic field is presented. Experimental results are shown for a sodium-23 compound, sodium pyruvate, and for oxygen-17 labeled L-akmine. In Chapter 5, a method for broadening the Hartmann-Hahn matching condition under MAS, called variable effective field cross-polarization (VEFCI?), is presented, along with experimental work on adamantane and polycarbonate.

Gann, Sheryl Lee

1995-11-30T23:59:59.000Z

285

TWENTY-FIVE SUBARCSECOND BINARIES DISCOVERED BY LUNAR OCCULTATIONS  

SciTech Connect (OSTI)

We report on 25 subarcsecond binaries, detected for the first time by means of lunar occultations in the near-infrared (near-IR) as part of a long-term program using the ISAAC instrument at the ESO Very Large Telescope. The primaries have magnitudes in the range K = 3.8-10.4, and the companions in the range K = 6.4-12.1. The magnitude differences have a median value of 2.8, with the largest being 5.4. The projected separations are in the range 6-748 mas and with a median of 18 mas, or about three times less than the diffraction limit of the telescope. Among our binary detections are a pre-main-sequence star and an enigmatic Mira-like variable previously suspected to have a companion. Additionally, we quote an accurate first-time near-IR detection of a previously known wider binary. We discuss our findings on an individual basis as far as made possible by the available literature, and we examine them from a statistical point of view. We derive a typical frequency of binarity among field stars of Almost-Equal-To 10%, in the resolution and sensitivity range afforded by the technique ( Almost-Equal-To 0.''003 to Almost-Equal-To 0.''5, and K Almost-Equal-To 12 mag, respectively). This is in line with previous results using the same technique but we point out interesting differences that we can trace up to sensitivity, time sampling, and average distance of the targets. Finally, we discuss the prospects for further follow-up studies.

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: andrea4work@gmail.com [European Southern Observatory, Casilla 19001, Santiago 19 (Chile)

2013-09-15T23:59:59.000Z

286

High angular resolution N-band observation of the silicate carbon star IRAS08002-3803 with the VLTI/MIDI instrument  

E-Print Network [OSTI]

We present the results of N-band spectro-interferometric observations of the silicate carbon star IRAS08002-3803 with the MID-infrared Interferometric instrument (MIDI) at the Very Large Telescope Interferometer (VLTI) of the European Southern Observatory (ESO). The observations were carried out using two unit telescopes (UT2 and UT3) with projected baseline lengths ranging from 39 to 47 m. Our observations of IRAS08002-3803 have spatially resolved the dusty environment of a silicate carbon star for the first time and revealed an unexpected wavelength dependence of the angular size in the N band: the uniform-disk diameter is found to be constant and ~36 mas (72 Rstar) between 8 and 10 micron, while it steeply increases longward of 10 micron to reach ~53 mas (106 Rstar) at 13 micron. Model calculations with our Monte Carlo radiative transfer code show that neither spherical shell models nor axisymmetric disk models consisting of silicate grains alone can simultaneously explain the observed wavelength dependence of the visibility and the spectral energy distribution (SED). We propose that the circumstellar environment of IRAS08002-3803 may consist of two grain species coexisting in the disk: silicate and a second grain species, for which we consider amorphous carbon, large silicate grains, and metallic iron grains. Comparison of the observed visibilities and SED with our models shows that such disk models can fairly -- though not entirely satisfactorily -- reproduce the observed SED and N-band visibilities. Our MIDI observations and the radiative transfer calculations lend support to the picture where oxygen-rich material around IRAS08002-3803 is stored in a circumbinary disk surrounding the carbon-rich primary star and its putative low-luminosity companion.

Keiichi Ohnaka; T. Driebe; K. -H. Hofmann; Ch. Leinert; S. Morel; F. Paresce; Th. Preibisch; A. Richichi; D. Schertl; M. Schoeller; L. B. F. M. Waters; G. Weigelt; M. Wittkowski

2005-09-26T23:59:59.000Z

287

Asymmetric silicate dust distribution toward the silicate carbon star BM Gem  

E-Print Network [OSTI]

Silicate carbon stars show the 10 micron silicate emission, despite their carbon-rich photospheres. They are considered to have circumbinary or circum-companion disks, which serve as a reservoir of oxygen-rich material shed by mass loss in the past. We present N-band spectro-interferometric observations of the silicate carbon star BM Gem using MIDI at the Very Large Telescope Interferometer (VLTI). Our aim is to probe the spatial distribution of oxygen-rich dust with high spatial resolution. BM Gem was observed with VLTI/MIDI at 44--62 m baselines using the UT2-UT3 and UT3-UT4 baseline configurations. The N-band visibilities observed for BM Gem show a steep decrease from 8 to ~10 micron and a gradual increase longward of ~10 micron, reflecting the optically thin silicate emission feature emanating from sub-micron-sized amorphous silicate grains. The differential phases obtained at baselines of ~44--46 m show significant non-zero values (~ -70 degrees) in the central part of the silicate emission feature between ~9 and 11 micron, revealing a photocenter shift and the asymmetric nature of the silicate emitting region. The observed N-band visibilities and differential phases can be fairly explained by a simple geometrical model in which the unresolved star is surrounded by a ring with azimuthal brightness modulation. The best-fit model is characterized by a broad ring (~70 mas across at 10 micron) with a bright region which is offset from the unresolved star by ~20 mas at a position angle of ~280 degrees. This model can be interpreted as a system with a circum-companion disk and is consistent with the spectroscopic signatures of an accretion disk around an unseen companion recently discovered in the violet spectrum of BM Gem.

Keiichi Ohnaka; Hideyuki Izumiura; Christoph Leinert; Thomas Driebe; Gerd Weigelt; Markus Wittkowski

2008-07-21T23:59:59.000Z

288

FIRST GROUND-BASED CHARGE-COUPLED DEVICE PROPER MOTIONS FOR FORNAX. II. FINAL RESULTS  

SciTech Connect (OSTI)

We present the first entirely ground-based astrometric determination of the proper motion for the Fornax Local Group dwarf spheroidal satellite galaxy of the Milky Way (MW), using charge-coupled device data acquired with the ESO 3.5 m New Technology Telescope at La Silla Observatory in Chile. Our unweighted mean from five quasar fields in the background of Fornax, used as fiducial reference points, leads to {mu}{sub {alpha}c}os {delta} = 0.62 {+-} 0.16 mas yr{sup -1} and {mu}{sub {delta}} = -0.53 {+-} 0.15 mas yr{sup -1}. A detailed comparison with all previous measurements of this quantity seems to imply that there is still no convincing convergence to a single value, perhaps indicating the existence of unaccounted systematic effects in (some of) these measurements. From all available proper-motion and radial velocity measurements for Fornax, we compute Fornax's orbital parameters and their uncertainty using a realistic Galactic potential and a Monte Carlo simulation. Properties of the derived orbits are then compared to main star formation episodes in the history of Fornax. All published proper-motion values imply that Fornax has recently (200-300 Myr ago) approached perigalacticon at a distance of {approx}150 kpc. However, the derived period exhibits a large scatter, as does the apogalacticon. Our orbit, being the most energetic, implies a very large apogalactic distance of {approx}950 kpc. If this were the case, then Fornax would be a representative of a hypervelocity MW satellite in late infall.

Mendez, Rene A.; Costa, Edgardo [Departamento de Astronomia, Universidad de Chile, Casilla 36-D, Santiago (Chile); Gallart, Carme [Instituto de Astrofisica de Canarias, Tenerife 38200, Islas Canarias (Spain); Pedreros, Mario H. [Departamento de Fisica, Universidad de Tarapaca, Casilla 7-D, Arica (Chile); Moyano, Maximiliano [Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, D-69117 Heidelberg (Germany); Altmann, Martin, E-mail: rmendez@das.uchile.cl, E-mail: costa@das.uchile.cl, E-mail: carme@iac.es, E-mail: mpedrero@uta.cl, E-mail: moyano@mpia-hd.mpg.de, E-mail: maltmann@ari.uni-heidelberg.de [Zentrum fuer Astronomie, Moenchhofstr. 12-14, 69120 Heidelberg (Germany)

2011-09-15T23:59:59.000Z

289

HIGH VELOCITY PRECESSING JETS FROM THE WATER FOUNTAIN IRAS 18286-0959 REVEALED BY VERY LONG BASELINE ARRAY OBSERVATIONS  

SciTech Connect (OSTI)

We report the results of multi-epoch Very Long Baseline Array observations of the 22.2 GHz H{sub 2}O maser emission associated with the 'water fountain' IRAS 18286-0959. We suggest that this object is the second example of a highly collimated bipolar precessing outflow traced by H{sub 2}O maser emission, the other is W 43A. The detected H{sub 2}O emission peaks are distributed over a velocity range from -50 km s{sup -1} to 150 km s{sup -1}. The spatial distribution of over 70% of the identified maser features is found to be highly collimated along a spiral jet (jet 1) extended southeast to northwest; the remaining features appear to trace another spiral jet (jet 2) with a different orientation. The two jets form a 'double-helix' pattern which lies across {approx}200 mas. The maser distribution is reasonably fit by a model consisting of two bipolar precessing jets. The three-dimensional velocities of jet 1 and jet 2 are derived to be 138 km s{sup -1} and 99 km s{sup -1}, respectively. The precession period of jet 1 is about 56 years. For jet 2, three possible models are tested and they give different values for the kinematic parameters. We propose that the appearance of two jets is the result of a single driving source with significant proper motion.

Yung, Bosco H. K.; Nakashima, Jun-ichi; Kwok, Sun [Department of Physics, University of Hong Kong, Pokfulam Rd., Hong Kong (Hong Kong); Imai, Hiroshi [Graduate School of Science and Engineering, Kagoshima University, Kagoshima 890-0065 (Japan); Deguchi, Shuji [Nobeyama Radio Observatory, National Astronomical Observatory of Japan, Minamimaki, Minamisaku, Nagano 384-1305 (Japan); Diamond, Philip J. [Jodrell Bank Centre for Astrophysics, Alan Turing Building, University of Manchester, Manchester M13 9PL (United Kingdom)

2011-11-10T23:59:59.000Z

290

Hydroconversion reactions catalyzed by highly stable pillared clays  

SciTech Connect (OSTI)

Al-pillared clays (Al-PILC) and Al-X-PILC (X = Ga, Ni), structurally stable at high temperature - in the case of Ga above 800{degrees}C-have been synthesized by controlling intercalation steps and stabilization procedures. New bidimensional materials with an interlaminar distance about 10-12{angstrom} and with different chemical reactivities in the pillars have thus been produced. The analytical techniques employed to characterize the materials and the processes involved during stabilization include N{sub 2} adsorption, AA, XRD, NH{sub 3}-TPD, TGA-DTA, HR- and MAS-NMR (Al, Si, and Ga) and in-situ IR and DRIFTS. Chemical characterization using high pressure reactions with probe molecules such as diphenylmethane and tert-butylbenzene shows selectivity patterns than can be clearly associated with the microstructure of the PILC used, as well as an effect due to the composition of the pillars. Similar studies with zeolites give patterns that differ from those of PILC, probably because of the change in dimensionality of the internal structure. Poisoning studies with metal porphyrins prove that PLIC have improved resistance compared to standard catalysts. Hydrotreatment of Maya crude results a significant reduction in total sulfur under conditions suitable for commercial operation.

Gomez, S.A.; Mosqueira, L.; Espinosa, J.; Fuentes, G.A. [Universidad A. Metropolitana-Iztapalapa (Mexico)

1993-12-31T23:59:59.000Z

291

An asymmetry detected in the disk of Kappa CMa with the AMBER/VLTI  

E-Print Network [OSTI]

Aims. We study the geometry and kinematics of the circumstellar environment of the Be star Kappa CMa in the Br gamma emission line and its nearby continuum. Methods. We use the VLTI/AMBER instrument operating in the K band which provides a spatial resolution of about 6 mas with a spectral resolution of 1500 to study the kinematics within the disk and to infer its rotation law. In order to obtain more kinematical constraints we also use an high spectral resolution Pa beta line profile obtain in December 2005 at the Observatorio do Pico do Dios, Brazil and we compile V/R line profile variations and spectral energy distribution data points from the literature. Results. Using differential visibilities and differential phases across the Br gamma line we detect an asymmetry in the disk. Moreover, we found that kappa CMa seems difficult to fit within the classical scenario for Be stars, illustrated recently by alpha Arae observations, i.e. a fast rotating B star close to its breakup velocity surrounded by a Kepleria...

Meilland, A; Stee, P; De Souza, A D; Petrov, R; Mourard, D; Jankov, S; Robbe-Dubois, S; Spang, A; Arisitidi, E; Meilland, Anthony; Millour, Florentin; Stee, Philippe; Souza, Armando Domiciano De; Petrov, Romain; Mourard, Denis; Jankov, Slobodan; Robbe-Dubois, Sylvie; Spang, Alain; Arisitidi, Eric; al, et

2006-01-01T23:59:59.000Z

292

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 (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{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

293

Unusual activation of novel Au/TiO2/AI2O3 xH2O catalysts by calcination  

SciTech Connect (OSTI)

Au/Al{sub 2}O{sub 3} {center_dot} xH{sub 2}O and Au/TiO{sub 2}/Al{sub 2}O{sub 3} {center_dot} xH{sub 2}O (x = 0-3) catalysts were prepared by assembling gold nanoparticles on neat and TiO{sub 2}-modified Al{sub 2}O{sub 3}, AlOOH, and Al(OH){sub 3} supports, and their catalytic activity in CO oxidation was tested either as synthesized or after on-line pretreatment in O{sub 2}-He at 500 C. A promotional effect of TiO{sub 2} on the activity of gold catalysts was observed upon 500 C-pretreatment. The catalyst stability as a function of time on stream was tested in the absence or presence of H{sub 2}, and physiochemical characterization applying BET, ICP-OES, XRD, TEM, and {sup 27}Al MAS NMR was conducted.

Yan, Wenfu [ORNL; Ma, Zhen [ORNL; Mahurin, Shannon Mark [ORNL; Overbury, Steven {Steve} H [ORNL; Dai, Sheng [ORNL

2008-01-01T23:59:59.000Z

294

SYNCHROTRON X-RAY MICROTOMOGRAPHY, ELECTRON PROBE MICROANALYSIS, AND NMR OF TOLUENE WASTE IN CEMENT.  

SciTech Connect (OSTI)

Synchrotron X-ray microtomography shows vesicular structures for toluene/cement mixtures, prepared with 1.22 to 3.58 wt% toluene. Three-dimensional imaging of the cured samples shows spherical vesicles, with diameters ranging from 20 to 250 {micro}m; a search with EPMA for vesicles in the range of 1-20 {micro}m proved negative. However, the total vesicle volume, as computed from the microtomography images, accounts for less than 10% of initial toluene. Since the cements were cured in sealed bottles, the larger portion of toluene must be dispersed within the cement matrix. Evidence for toluene in the cement matrix comes from {sup 29}Si MAS NMR spectroscopy, which shows a reduction in chain silicates with added toluene. Also, {sup 2}H NMR of d{sub 8}-toluene/cement samples shows high mobility for all, toluene and thus no toluene/cement binding. A model that accounts for all observations follows: For loadings below about 3 wt%, most toluene is dispersed in the cement matrix, with a small fraction of the initial toluene phase separating from the cement paste and forming vesicular structures that are preserved in the cured cement. Furthermore, at loadings above 3 wt%, the abundance of vesicles formed during toluene/cement paste mixing leads to macroscopic phase separation (most toluene floats to the surface of the cement paste).

BUTLER,L.G.

1999-07-22T23:59:59.000Z

295

The First Science Results from SPHERE: Disproving the Predicted Brown Dwarf around V471 Tau  

E-Print Network [OSTI]

Variations of eclipse arrival times have recently been detected in several post common envelope binaries consisting of a white dwarf and a main sequence companion star. The generally favoured explanation for these timing variations is the gravitational pull of one or more circumbinary substellar objects periodically moving the center of mass of the host binary. Using the new extreme-AO instrument SPHERE, we image the prototype eclipsing post-common envelope binary V471 Tau in search of the brown dwarf that is believed to be responsible for variations in its eclipse arrival times. We report that an unprecedented contrast of 12.1 magnitudes in the H band at a separation of 260 mas was achieved, but resulted in a non-detection. This implies that there is no brown dwarf present in the system unless it is three magnitudes fainter than predicted by evolutionary track models, and provides damaging evidence against the circumbinary interpretation of eclipse timing variations. In the case of V471 Tau, a more consisten...

Hardy, A; Parsons, S G; Caceres, C; Retamales, G; Wahhaj, Z; Mawet, D; Canovas, H; Cieza, L; Marsh, T R; Bours, M C P; Dhillon, V S; Bayo, A

2015-01-01T23:59:59.000Z

296

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

SciTech Connect (OSTI)

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

297

The Stability of Organic Solvents and Carbon Electrode in Nonaqueous Li-O2 Batteries  

SciTech Connect (OSTI)

The effect of different kinds of aprotic organic solvents on the discharge performance and discharge products in Li-O2 batteries was systematically investigated. The discharge products deposited in air cathodes were analyzed by X-ray diffraction, in situ gas chromatography/mass spectroscopy and X-ray photoelectron spectroscopy. We found that a significant amount of Li2O2 can be formed in glyme-based electrolytes during the discharge process, while only small amount of Li2O2 is produced in electrolytes of phosphate, nitrile, ionic liquid and sulfoxide. However, in all the seven types of solvent systems we studied, Li2CO3 and LiF were still formed as byproducts whose compositions are strongly related to the solvents. Li2CO3 is produced not from the carbon air electrode but from oxidation and decomposition of the solvent as we verified by using a 13C-labeled carbon electrode and the solid-state 13C-MAS NMR technique. The formation of Li2CO3 and LiF during discharge will greatly reduce the Coulombic efficiency and cycle life of the Li-air batteries. Therefore, better electrolytes that can ensure the formation of Li2O2 but minimize other reaction products formed on air electrodes of Li-air batteries need to be further investigated.

Xu, Wu; Hu, Jian Z.; Engelhard, Mark H.; Towne, Silas A.; Hardy, John S.; Xiao, Jie; Feng, Ju; Hu, Mary Y.; Zhang, Jian; Ding, Fei; Gross, Mark E.; Zhang, Jiguang

2012-05-18T23:59:59.000Z

298

Preparation of hexagonal WO{sub 3} from hexagonal ammonium tungsten bronze for sensing NH{sub 3}  

SciTech Connect (OSTI)

Hexagonal tungsten oxide (h-WO{sub 3}) was prepared by annealing hexagonal ammonium tungsten bronze, (NH{sub 4}){sub 0.07}(NH{sub 3}){sub 0.04}(H{sub 2}O){sub 0.09}WO{sub 2.95}. The structure, composition and morphology of h-WO{sub 3} were studied by XRD, XPS, Raman, {sup 1}H MAS (magic angle spinning) NMR, scanning electron microscopy (SEM), and BET-N{sub 2} specific surface area measurement, while its thermal stability was investigated by in situ XRD. The h-WO{sub 3} sample was built up by 50-100 nm particles, had an average specific surface area of 8.3 m{sup 2}/g and was thermally stable up to 450 deg. C. Gas sensing tests showed that h-WO{sub 3} was sensitive to various levels (10-50 ppm) of NH{sub 3}, with the shortest response and recovery times (1.3 and 3.8 min, respectively) to 50 ppm NH{sub 3}. To this NH{sub 3} concentration, the sensor had significantly higher sensitivity than h-WO{sub 3} samples prepared by wet chemical methods.

Szilagyi, Imre Miklos [Materials Structure and Modeling Research Group of the Hungarian Academy of Sciences, Budapest University of Technology and Economics, H-1111 Budapest, Szt. Gellert ter 4 (Hungary)], E-mail: imre.szilagyi@mail.bme.hu; Wang Lisheng; Gouma, Pelagia-Irene [Department of Materials Science and Engineering, 314 Old Engineering Building, SUNY, Stony Brook, NY 11794-2275 (United States); Balazsi, Csaba [Ceramics and Nanocomposites Laboratory, Research Institute for Technical Physics and Materials Science, H-1121 Budapest, Konkoly-Thege ut 29-33 (Hungary); Madarasz, Janos; Pokol, Gyoergy [Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, H-1111 Budapest, Szt. Gellert ter 4 (Hungary)

2009-03-05T23:59:59.000Z

299

PSR B0329+54: Substructure in the scatter-broadened image discovered with RadioAstron on baselines of up to 235,000 km  

E-Print Network [OSTI]

We studied scattering properties of the pulsar PSR B0329+54 with a ground-space radio interferometer RadioAstron which included the 10-m Space Radio Telescope, the 110-m Green Bank Telescope, the 14x25-m Westerbork Synthesis Radio Telescope, and the 64-m Kalyazin Radio Telescope. The observations were performed at 324 MHz on baselines of up to 235,000 km in November 2012 and January 2014. At short ground-space baselines of less than about 20,000 km, the visibility amplitude decreases with the projected baseline length, providing a direct measurement of the diameter of the scattering disk of 4.7$\\pm$0.9 mas. The size of the diffraction spot near Earth is 15,000$\\pm$3,000 km. At longer baselines of up to 235,000 km, where no interferometric detection of the scattering disk would be expected, significant visibilities were observed with amplitudes scattered around a constant value. These detections result in a discovery of a substructure in the completely resolved scatter-broadened image of the pointlike source, ...

Popov, M V; Bartel, N; Gwinn, C R; Johnson, M D; Joshi, B C; Kardashev, N S; Karuppusamy, R; Kovalev, Y Y; Kramer, M; Rudnitskii, A G; Safutdinov, E R; Shishov, V I; Smirnova, T V; Soglasnov, V A; Zensus, J A; Zhuravlev, V I

2015-01-01T23:59:59.000Z

300

Hydrogen Storage Properties of New Hydrogen-Rich BH3NH3-Metal Hydride (TiH2, ZrH2, MgH2, and/or CaH2) Composite Systems  

SciTech Connect (OSTI)

Ammonia borane (AB = NH3BH3) is one of the most attractive materials for chemical hydrogen storage due to its high hydrogen contents of 19.6 wt.%, however, impurity levels of borazine, ammonia and diborane in conjunction with foaming and exothermic hydrogen release calls for finding ways to mitigate the decomposition reactions. In this paper we present a solution by mixing AB with metal hydrides (TiH2, ZrH2, MgH2 and CaH2) which have endothermic hydrogen release in order to control the heat release and impurity levels from AB upon decomposition. The composite materials were prepared by mechanical ball milling, and their H2 release properties were characterized by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The formation of volatile products from decomposition side reactions, such as borazine (N3B3H6) was determined by mass spectrometry (MS). Sieverts type pressure-composition-temperature (PCT) gas-solid reaction instrument was adopted to observe the kinetics of the H2 release reactions of the combined systems and neat AB. In situ 11B MAS-NMR revealed a destabilized decomposition pathway. We found that by adding specific metal hydrides to AB we can eliminate the impurities and mitigate the heat release.

Choi, Young Joon; Xu, Yimin; Shaw, Wendy J.; Ronnebro, Ewa

2012-04-19T23:59:59.000Z

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301

Multiangle Observations of Arctic Clouds from FIRE ACE: June 3, 1998 Case Study  

SciTech Connect (OSTI)

In May and June 1998 the Airborne Multiangle Imaging Spectroradiometer (AirMISR) participated in the FIRE Arctic Cloud Experiment (ACE). AirMISR is an airborne instrument for obtaining multiangle imagery similar to that of the satellite-borne MISR instrument. This paper presents a detailed analysis of the data collected on June 3, 1998. In particular, AirMISR radiance measurements are compared with measurements made by two other instruments, the Cloud Absorption Radiometer (CAR) and the MODIS airborne simulator (MAS), as well as to plane-parallel radiative transfer simulations. It is found that the AirMISR radiance measurements and albedo estimates compare favorably both with the other instruments and with the radiative transfer simulations. In addition to radiance and albedo, the multiangle AirMISR data can be used to obtain estimates of cloud top height using stereoimaging techniques. Comparison of AirMISR retrieved cloud top height (using the complete MISR-based stereoimaging approach) shows excellent agreement with the measurements from the airborne Cloud Lidar System (CLS) and ground-based millimeter-wave cloud radar.

Marchand, Roger T.; Ackerman, Thomas P.; King, M. D.; Moroney, C.; Davies, R.; Muller, J.-P. A. L.; Gerber, H.

2001-07-27T23:59:59.000Z

302

Parallel Index and Query for Large Scale Data Analysis  

SciTech Connect (OSTI)

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

303

A LIKELY CLOSE-IN LOW-MASS STELLAR COMPANION TO THE TRANSITIONAL DISK STAR HD 142527  

SciTech Connect (OSTI)

With the uniquely high contrast within 0.''1 ({Delta}mag(L') = 5-6.5 mag) available using Sparse Aperture Masking with NACO at Very Large Telescope, we detected asymmetry in the flux from the Herbig Fe star HD 142527 with a barycenter emission situated at a projected separation of 88 {+-} 5 mas (12.8 {+-} 1.5 AU at 145 pc) and flux ratios in H, K, and L' of 0.016 {+-} 0.007, 0.012 {+-} 0.008, and 0.0086 {+-} 0.0011, respectively (3{sigma} errors), relative to the primary star and disk. After extensive closure-phase modeling, we interpret this detection as a close-in, low-mass stellar companion with an estimated mass of {approx}0.1-0.4 M{sub Sun }. HD 142527 has a complex disk structure, with an inner gap imaged in both the near and mid-IR as well as a spiral feature in the outer disk in the near-IR. This newly detected low-mass stellar companion may provide a critical explanation of the observed disk structure.

Biller, Beth; Benisty, Myriam; Chauvin, Gael; Olofsson, Johan; Pott, Joerg-Uwe; Mueller, Andre; Bonnefoy, Mickaeel; Henning, Thomas [Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, 69117 Heidelberg (Germany); Lacour, Sylvestre; Thebault, Philippe [LESIA, CNRS/UMR-8109, Observatoire de Paris, UPMC, Universite Paris Diderot, 5 place Jules Janssen, 92195 Meudon (France); Juhasz, Attila [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden (Netherlands); Sicilia-Aguilar, Aurora [Departamento de Fisica Teorica, Facultad de Ciencias, Universidad Autonoma de Madrid, 28049 Cantoblanco, Madrid (Spain); Tuthill, Peter [School of Physics, University of Sydney, NSW 2006 (Australia); Crida, Aurelien, E-mail: biller@mpia.de [Universite de Nice - Sophia antipolis/C.N.R.S./Observatoire de la Cote d'Azur, Laboratoire Lagrange (UMR 7293), Boulevard de l'Observatoire, B.P. 4229 06304 NICE cedex 04 (France)

2012-07-10T23:59:59.000Z

304

ALMA 690 GHz OBSERVATIONS OF IRAS 16293-2422B: INFALL IN A HIGHLY OPTICALLY THICK DISK  

SciTech Connect (OSTI)

We present sensitive, high angular resolution ({approx}0.''2) submillimeter continuum and line observations of IRAS 16293-2422B made with the Atacama Large Millimeter/Submillimeter Array. The 0.45 mm continuum observations reveal a single and very compact source associated with IRAS 16293-2422B. This submillimeter source has a deconvolved angular size of about 400 mas (50 AU) and does not show any inner structure inside of this diameter. The H{sup 13}CN, HC{sup 15}N, and CH{sub 3}OH line emission regions are about twice as large as the continuum emission and reveal a pronounced inner depression or ''hole'' with a size comparable to that estimated for the submillimeter continuum. We suggest that the presence of this inner depression and the fact that we do not see an inner structure (or a flat structure) in the continuum are produced by very optically thick dust located in the innermost parts of IRAS 16293-2422B. All three lines also show pronounced inverse P-Cygni profiles with infall and dispersion velocities larger than those recently reported from observations at lower frequencies, suggesting that we are detecting faster and more turbulent gas located closer to the central object. Finally, we report a small east-west velocity gradient in IRAS 16293-2422B that suggests that its disk plane is likely located very close to the plane of the sky.

Zapata, Luis A.; Loinard, Laurent; Rodriguez, Luis F.; Hernandez-Hernandez, Vicente [Centro de Radioastronomia y Astrofisica, UNAM, Apdo. Postal 3-72 (Xangari), 58089 Morelia, Michoacan (Mexico); Takahashi, Satoko; Trejo, Alfonso [Academia Sinica Institute of Astronomy and Astrophysics, P.O. Box 23-141, Taipei 10617, Taiwan (China); Parise, Berengere [Max-Planck-Institut fuer Radioastronomie, Auf dem Huegel 69, D-53121 Bonn (Germany)

2013-02-10T23:59:59.000Z

305

Synthesis and characterization of low-OH?fluor-chlorapatite: A single-crystal XRD and NMR spectroscopic study  

SciTech Connect (OSTI)

Los-OH apatite of the compositional range Ca{sub 4.99-5.06}(PO{sub 4}){sub 2.98-3.00}F{sub 0.51-0.48}Cl{sub 0.38-0.36}OH{sub 0.14-0.12} was synthesized and characterized structurally by synchrotron-based single-crystal X-ray diffraction (XRD), and multiple nuclear magnetic resonance (NMR) spectroscopic techniques. the average structure is hexagonal with space group P6{sub 3}/m. The presence of scattering in the single-crystal diffraction data set, which is incommensurate within the average hexagonal structure, suggests the presence of localized short-range monoclinic domains. Complex lineshapes in the {sup 31}P and {sup 19}F MAS NMR spectra are also consistent with the presence of an incommensurate phase. No evidence was detected for splitting of the Ca2 site into two distinct sites (as had been previously reported for hexagonal ternary apatities). Structure refinement and {sup 19}F{l_brace}{sup 35}Cl{r_brace} TRAPDOR NMR experiments verified intercolumnal neighboring of F and Cl atoms (inter-column distance of 2.62 {angstrom}) within this low-OH{sup -} apatite suggesting that long-range neighboring of F and Cl within the apatite anion channels is feasible.

McCubbin, Francis M.; Mason, Harris E.; Park, Hyunsoo; Phillips, Brian L.; Parise, John B.; Nekvasil, Hanna; Lindsley, Donald H. (SBU)

2008-12-12T23:59:59.000Z

306

Flexibility of the zeolite RHO framework. In situ X-ray and neutron powder structural characterization of cation-exchanged BePO and BeAsORHO analogs  

SciTech Connect (OSTI)

This is an extensive study of the non-aluminosilicate analogs of the zeolite RHO. This molecular sieve is of great interest commercially because of its catalytic properties. In the absence of rigid supporting structural subunits (smaller cages or channels), the aluminosilicate RHO exhibits atypical framework flexibility with large displacivere arrangements. The beryllophosphate and beryalloarsenate analogs are easily synthesized under very mild reaction conditions and therefore maybe of interest for inexpensive and rapid commercial production. However,t hey have decreased thermal stability. In an effort to increase thermal stability and explore framework flexibility, we have synthesized and characterized a series of analogs of the non-aluminosilicate RHO framework. All materials crystallize in the space group I23, ranging from a = 13.584-(2) A for Li-BePO RHO to a = 14.224(4) A for Ba-RbBeAsO RHO for hydrated phases. The extra framework cations are distributed over the double 8-ring, single 8-ring, and two single 6-ring sites. Partially and fully dehydrated phases were also studied for changes in framework stability. Predictive trends based on the type of cation exchanged into the framework were determined by {sup 9}Be and {sup 31}P MAS NMR. 50 refs., 8 figs., 6 tabs.

Nenoff, T.M. [Univ. of California, Santa Barbara, CA (United States)] [Univ. of California, Santa Barbara, CA (United States); Parise, J.B. [State Univ. of New York, Stony Brook, NY (United States)] [State Univ. of New York, Stony Brook, NY (United States); Jones, G.A.; Galya, L.G.; Corbin, D.R.; Stucky, G.D. [DuPont Co., Wilmington, DE (United States)] [DuPont Co., Wilmington, DE (United States)

1996-08-15T23:59:59.000Z

307

A Brown Dwarf Microlens Candidate in the OGLE-II Database  

E-Print Network [OSTI]

We describe a unique mass determination for a microlensing event from the second phase of the Optical Gravitational Microlensing Experiment (OGLE-II). The event, sc26_2218, which is very bright (baseline magnitude I=15.10), appears to exhibit both parallax and finite source effects. The parallax effect allows us to determine the projected Einstein radius on the observer plane (approx. 3.8 AU), while the finite source effect allows us to determine the ratio of the angular source size and the angular Einstein radius. As the angular size of the star can be estimated using its color and magnitude, we can hence determine the angular Einstein radius (approx. 0.1 mas). By combining both the projected and angular Einstein radius we can determine the lens mass M = 0.050^{+0.016}_{-0.011} solar masses, independent of the source distance. The lens is therefore a brown dwarf candidate. However, the `parallax' signature is weak and so we cannot completely discount the possibility that these signatures originate from binary rotation of the source (which would prevent any estimate of the lens mass), rather than parallax. However, this can be tested by future spectroscopic observations. This event highlights the scientific returns for intense monitoring of bright microlensing events, since the parallax and finite source effects can be more easily identified due to their high signal-to-noise ratios.

M. C. Smith; S. Mao; P. R. Wozniak

2003-01-16T23:59:59.000Z

308

Continuing EVN monitoring of HST-1 in the jet of M87  

E-Print Network [OSTI]

The relativistic jet in M87 offers a unique opportunity for understanding the detailed jet structure and emission processes due to its proximity. In particular, the peculiar jet region HST-1 at ~1 arcsecond (or 80 pc, projected) from the nucleus has attracted a great deal of interest in the last decade because of its superluminal motion and broadband radio-to-X-ray outbursts, which may be further connected to the gamma-ray productions up to TeV energies. Over the last five years, we have been doing an intensive monitoring of HST-1 with EVN at 5GHz in order to examine the detailed structural evolution and its possible connection to high-energy activities. While this program already yielded interesting results in terms of the detailed mas-scale structure, proper motion measurements and structural variations, the recent HST-1 brightness is continuously decreasing at this frequency. To counter this, we have shifted our monitoring frequency to 1.7GHz from October 2013. This strategy successfully recovered the fain...

Hada, Kazuhiro; Giovannini, Gabriele; Casadio, Carolina; Beilicke, Matthias; Cesarini, Andrea; Cheung, Teddy; Doi, Akihiro; Gmez, Jos Luis; Krawczynski, Henric; Kino, Motoki; Nagai, Hiroshi

2015-01-01T23:59:59.000Z

309

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; Muoz, 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; Fouqu, 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; Harpse, K; Hinse, T C; Hundertmark, M; Jrgensen, U G; Kerins, E; Liebig, C; Maier, G; Mancini, L; Mathiasen, M; Penny, M T; Proft, S; Rahvar, S; Ricci, D; Scarpetta, G; Schfer, S; Schnebeck, F; Skottfelt, J; Surdej, J; Southworth, J; Zimmer, F

2011-01-01T23:59:59.000Z

310

Unlocking the Standard Model. IV. N=2 generations of quarks : spectrum and mixing  

E-Print Network [OSTI]

The Glashow-Salam-Weinberg model for 2 generations of quarks is extended to 8 composite Higgs multiplets, with no adjunction of extra fermions. It is the minimal number of Higgs doublets required to suitably account, simultaneously, for the spectrum of pseudoscalar mesons that can be built with 4 quarks and for the mass of the W gauge bosons. These masses being used as input, together with elementary low energy considerations for the pions, we calculate all other parameters, masses and couplings. We focus in this work on the spectrum of the 8 Higgs bosons (which all potentially contribute to the W and quark masses), and on the mixing (Cabibbo) angle, leaving the study of couplings to a subsequent work. The Higgs bosons fall into one triplet, two doublets and one singlet. In the triplet stand three states with masses \\sqrt{2} x that of heaviest pseudoscalar meson D_s, which, for 2 generations, pushes them up to 2.80 GeV. The 2 components of the first doublet have masses close to 1.25 GeV. The singlet has a mas...

Machet, Bruno

2013-01-01T23:59:59.000Z

311

V405 Peg (RBS 1955): A Nearby, Low-Luminosity Cataclysmic Binary  

E-Print Network [OSTI]

(Abridged). The cataclysmic binary V405 Peg, originally discovered as ROSAT Bright Source (RBS) 1955 (= 1RXS J230949.6+213523), shows a strong contribution from a late-type secondary star in its optical spectrum, which led Schwope et al. to suggest it to be among the nearest cataclysmic binaries. We present extensive optical observations of V405 Peg. Time-series spectroscopy shows the orbital period, Porb, to be 0.1776469(7) d (= 4.2635 hr), or 5.629 cycle/d. We classify the secondary as M3 - M4.5. Astrometry with the MDM 2.4m telescope gives a parallax 7.2 +- 1.1 milli-arcsec, and a relative proper motion of 58 mas/yr. Our best estimate of the distance yields d = 149 (+26, -20) pc. The secondary stars's radial velocity has K2 = 92 +- 3 km/s, indicating a fairly low orbital inclination if the masses are typical. Extensive I-band time-series observations in the show the system varying between a minimum brightness level of I = 14.14 and states of enhanced activity about 0.2 mag brighter. While the low-state sho...

Thorstensen, J R; Schwope, A D; Staude, A; Vogel, J; Krumpe, M; Kohnert, J; Gomez-Moran, A Nebot

2009-01-01T23:59:59.000Z

312

The Last of FIRST: The Final Catalog and Source Identifications  

E-Print Network [OSTI]

The FIRST survey, begun over twenty years ago, provides the definitive high-resolution map of the radio sky. This VLA survey reaches a 20cm detection sensitivity of 1 mJy over 10,575 deg**2 largely coincident with the SDSS area. Images and a catalog containing 946,432 sources are available through the FIRST web site (http://sundog.stsci.edu). We record here the authoritative survey history, including hardware and software changes that affect the catalog's reliability and completeness. We use recent JVLA observations to test the survey astrometry and flux bias/scale. Our sidelobe-flagging algorithm finds that fewer than 10% of the catalogued objects are likely sidelobes; these are faint sources concentrated near bright sources, as expected. A match with the NRAO VLA Sky Survey shows very good consistency in flux scale and astrometry. Matches with 2MASS and SDSS indicate a systematic 10-20mas astrometric error with respect to the optical reference frame in old VLA data that has disappeared with the advent of th...

Helfand, David J; Becker, Robert H

2015-01-01T23:59:59.000Z

313

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

SciTech Connect (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

314

NEAT, An Astrometric Telescope To Probe Planetary Systems Down To The Earth Mass Around Nearby Solar-Type Stars  

E-Print Network [OSTI]

The NEAT (Nearby Earth Astrometric Telescope) mission is a proposition submitted to ESA for its 2010 call for M-size mission. The main scientific goal is to detect and characterize planetary systems in an exhaustive way down to 1 Earth mass in the habitable zone and further away, around nearby stars for F, G, and K spectral types. This survey would provide the actual planetary masses, the full characterization of the orbits including their inclination, for all the components of the planetary system down to that mass limit. Extremely- high-precision astrometry, in space, can detect the dynamical effect due to even low mass orbiting planets on their central star, reaching those scientific goals. NEAT will continue the work performed by Hipparcos (1mas precision) and Gaia (7{\\mu}as aimed) by reaching a precision that is improved by two orders of magnitude (0.05{\\mu}as, 1{\\sigma} accuracy). The two modules of the payload, the telescope and the focal plane, must be placed 40m away leading to a formation flying opt...

Malbet, F; Goullioud, R; Shao, M; Lagage, P -O; Cara, C; Durand, G; Feautrier, P; Jakobsson, B; Hinglais, E; Mercier, M

2011-01-01T23:59:59.000Z

315

Synthesis and characterization of nanoapatites organofunctionalized with aminotriphosphonate agents  

SciTech Connect (OSTI)

Organofunctionalized apatite nanoparticles were prepared using a one step process involving dissolution/precipitation of natural phosphate rock and covalent grafting of nitrilotris(methylene)triphosphonate (NTP). The synthesized materials were characterized by Brunauer-Emmett-Teller (BET) surface measurement, thermogravimetry, inductively coupled plasma emission spectroscopy (ICP-ES), elemental analysis, multinuclear solid state cross-polarization/magic angle spinning (CP/MAS) and single-pulse NMR spectroscopy, transmission electron microscopy (TEM) and energy dispersive X-ray analysis (EDXA). After grafting BET measurements yielded particle specific surface areas ranging from 88 to 193 m{sup 2} g{sup -1} depending on the grafted phosphonate. The results show that the surfaces of the nanoapatite particles can be covered with functional groups bound through a variable number of R-P-O-Ca bonds to render them organoapatites. - Graphical Abstract: Hydroxyapatite in the form of naturally occurring phosphate rock is converted in the presence of nitrilotris(methylene)triphosphonate (NTP) to high surface area apatite nanoparticles (dimensions measured by TEM) with NTP-functionalized surfaces. Highlights: Black-Right-Pointing-Pointer Surface functionalized hydroxyapatite nanoparticles are prepared from natural phosphate rock in a one-step process. Black-Right-Pointing-Pointer Covalent grafting of amine phosphonates to the nanoparticle surface is simultaneously accomplished by the presence of the organic molecules in the solution. Black-Right-Pointing-Pointer Mesoporous particles of high surface area are created. Black-Right-Pointing-Pointer Surface coverage is controlled by the concentration of amine phosphonate.

Saoiabi, Sanaa [Laboratoire de Chimie Physique Generale, Faculte des Sciences BP 1014, Universite Mohamed V-Agdal, Rabat (Morocco); UPMC Univ Paris 06, UMR 7574, Chimie de la Matiere Condensee de Paris, 4 Place Jussieu, F-75005 Paris (France); Biomaterials Laboratory, Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Room 2320, 149 13 Street, Charlestown, MA 02129 (United States); El Asri, Sanae [Laboratoire de Chimie Physique Generale, Faculte des Sciences BP 1014, Universite Mohamed V-Agdal, Rabat (Morocco); Laghzizil, Abdelaziz, E-mail: laghzizi@fsr.ac.ma [Laboratoire de Chimie Physique Generale, Faculte des Sciences BP 1014, Universite Mohamed V-Agdal, Rabat (Morocco); Masse, Sylvie [UPMC Univ Paris 06, UMR 7574, Chimie de la Matiere Condensee de Paris, 4 Place Jussieu, F-75005 Paris (France); Ackerman, Jerome L., E-mail: jerry@nmr.mgh.harvard.edu [Biomaterials Laboratory, Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Room 2320, 149 13 Street, Charlestown, MA 02129 (United States)

2012-01-15T23:59:59.000Z

316

Fluorine-Containing ABC Linear Triblock Terpolymers: Synthesis and Self-assembly in Solution  

SciTech Connect (OSTI)

In this paper a fluorine-containing monomer, 2-fluroroethyl methacrylate (2FEMA) was used to synthesize the linear triblock terpolymer poly(n-butyl methacrylate)-poly(methyl methacrylate)-poly(2-fluoroethyl methacrylate) (PnBMA-PMMA-P2FEMA). A kinetic study of the homopolymerization of 2FEMA by reversible addition-fragmentation chain transfer (RAFT) polymerization showed that it demonstrates living character and produces well defined polymers with reasonably narrow polydispersities (~1.30). Triblock terpolymers were prepared sequentially using a purified Macro-CTA at 70 oC, resulting in final terpolymers with high Dp for each block (>150) and with polydispersities between 1.6 and 2.1. The structure and molecular weights of the resultant PnBMA-PMMA-P2FEMA triblock terpolymers were characterized via 1H NMR, 19F NMR, and gel permeation chromatography (GPC). Self-assembly of these polymers was carried out in a selective solvent and the micellar aggregates (MAs) thereby formed were analyzed using scanning electron microscopy (SEM) and dynamic light scattering (DLS). It was confirmed from SEM that these copolymers could directly self-organize into large compound micelles in tetrahydrofuran/methanol with different diameters, depending on polymer composition.

He, Lihong [ORNL; Hinestrosa Salazar, Juan P [ORNL; Pickel, Joseph M [ORNL; Kilbey, II, S Michael [ORNL; Mays, Jimmy [ORNL; Zhang, Shanju [Georgia Institute of Technology; Bucknall, David G. [Georgia Institute of Technology; Hong, Kunlun [ORNL

2011-01-01T23:59:59.000Z

317

Heating of the molecular gas in the massive outflow of the local ultraluminous-infrared and radio-loud galaxy 4C12.50  

E-Print Network [OSTI]

We present a comparison of the molecular gas properties in the outflow vs. in the ambient medium of the local prototype radio-loud and ultraluminous-infrared galaxy 4C12.50 (IRAS13451+1232), using new data from the IRAM Plateau de Bure interferometer and 30m telescope, and the Herschel space telescope. Previous H_2 (0-0) S(1) and S(2) observations with the Spitzer space telescope had indicated that the warm (~400K) molecular gas in 4C12.50 is made up of a 1.4(+-0.2)x10^8 M_sun ambient reservoir and a 5.2(+-1.7)x10^7 M_sun outflow. The new CO(1-0) data cube indicates that the corresponding cold (25K) H_2 gas mass is 1.0(+-0.1)x10^10 M_sun for the ambient medium and = 30 times higher in the outflow than in the ambient medium, indicating that a non-negligible fraction of the accelerated gas is heated to temperatures at which star formation is inefficient. This conclusion is robust against the use of different alpha factor values, and/or different warm gas tracers (H_2 vs. H_2 plus CO): with the CO-probed gas mas...

Dasyra, K M; Novak, G S; Bremer, M; Spinoglio, L; Santaella, M Pereira; Salome, P; Falgarone, E

2014-01-01T23:59:59.000Z

318

Thermo-physical and structural studies of sodium zinc borovanadate glasses in the region of high concentration of modifier oxides  

SciTech Connect (OSTI)

Highlights: ? Highly modified sodium zinc borovanadate glasses. ? Structural model for borovanadate glasses. ? Network forming tendency of ZnO in borovanadate glasses. ? Fragility can be limited to NBO concentration in borovanadate glasses. -- Abstract: This paper reports investigation of Na{sub 2}O and ZnO modified borovanadate glasses in the highly modified regime of compositions. These glasses have been prepared by microwave route. Ultraviolet (UV) and visible, infrared (IR), Magic Angle Spinning Nuclear Magnetic Resonance (MAS NMR) and Electron Paramagnetic Resonance (EPR) spectroscopies have been used to characterize the speciation in the glasses. Together with the variation of properties such as molar volume and glass transition temperatures, spectroscopic data indicate that at high levels of modification, ZnO tends to behave like network former. It is proposed that the observed variation of all the properties can be reasonably well understood with a structural model. The model considers that the modification and speciation in glasses are strongly determined by the hierarchy of group electronegativities. Further, it is proposed that the width of the transitions of glasses obtained under same condition reflects the fragility of the glasses. An empirical expression has been suggested to quantify fragility on the basis of width of the transition regions.

Chethana, B.K. [Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560 012 (India)] [Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560 012 (India); Reddy, C. Narayana [Maharani's Science College for Women, Bangalore 560 001 (India)] [Maharani's Science College for Women, Bangalore 560 001 (India); Rao, K.J., E-mail: kalyajrao@yahoo.co.in [Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560 012 (India)

2012-07-15T23:59:59.000Z

319

Quantitatively Probing the Al Distribution in Zeolites  

SciTech Connect (OSTI)

The degree of substitution of Si4+ by Al3+ in the oxygen-terminated tetrahedra (Al T-sites) of zeolites determines the concentration of ion-exchange and Brnsted acid sites. As the location of the tetrahedra and the associated subtle variations in bond angles influence the acid strength, quantitative information about Al T-sites in the framework is critical to rationalize catalytic properties and to design new catalysts. A quantitative analysis is reported that uses a combination of extended X-ray absorption fine structure (EXAFS) analysis and 27Al MAS NMR spectroscopy supported by DFT-based molecular dynamics simulations. To discriminate individual Al atoms, sets of ab initio EXAFS spectra for various T-sites are generated from DFT-based molecular dynamics simulations allowing quantitative treatment of the EXAFS single- and multiple-photoelectron scattering processes out to 3-4 atom shells surrounding the Al absorption center. It is observed that identical zeolite types show dramatically different Al-distributions. A preference of Al for T-sites that are part of one or more 4-member rings in the framework over those T-sites that are part of only 5- and 6-member rings in the HBEA150 sample has been determined from a combination of these methods. This work was supported by the U. S. Department of Energy (DOE), Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences.

Vjunov, Aleksei; Fulton, John L.; Huthwelker, Thomas; Pin, Sonia; Mei, Donghai; Schenter, Gregory K.; Govind, Niranjan; Camaioni, Donald M.; Hu, Jian Z.; Lercher, Johannes A.

2014-06-11T23:59:59.000Z

320

An ancient F-type subdwarf from the halo crossing the Galactic plane  

E-Print Network [OSTI]

AIMS: We selected the bluest object, WISE~J0725$-$2351, from Luhman's new high proper motion (HPM) survey based on observations with the Wide-field Infrared Survey Explorer (WISE) for spectroscopic follow-up observations. Our aim was to unravel the nature of this relatively bright ($V$$\\sim$12, $J$$\\sim$11) HPM star ($\\mu$$=$267\\,mas/yr). METHODS: We obtained low- and medium-resolution spectra with the European Southern Observatory (ESO) New Technology Telescope (NTT)/EFOSC2 and Very Large Telescope (VLT)/XSHOOTER instruments, investigated the radial velocity and performed a quantitative spectral analysis that allowed us to determine physical parameters. The fit of the spectral energy distribution based on the available photometry to low-metallicity model spectra and the similarity of our target to a metal-poor benchmark star (HD~84937) allowed us to estimate the distance and space velocity. RESULTS: As in the case of HD~84937, we classified WISE~J0725$-$2351 as sdF5: or a metal-poor turnoff star with $[Fe/H]...

Scholz, R -D; Heuser, C; Ziegerer, E; Geier, S; Niederhofer, F

2015-01-01T23:59:59.000Z

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321

The Red Radio Ring: a gravitationally lensed hyperluminous infrared radio galaxy at z=2.553 discovered through citizen science  

E-Print Network [OSTI]

We report the discovery of a gravitationally lensed hyperluminous infrared galaxy (L_IR~10^13 L_sun) with strong radio emission (L_1.4GHz~10^25 W/Hz) at z=2.553. The source was identified in the citizen science project SpaceWarps through the visual inspection of tens of thousands of iJKs colour composite images of Luminous Red Galaxies (LRGs), groups and clusters of galaxies and quasars. Appearing as a partial Einstein ring (r_e~3") around an LRG at z=0.2, the galaxy is extremely bright in the sub-millimetre for a cosmological source, with the thermal dust emission approaching 1 Jy at peak. The redshift of the lensed galaxy is determined through the detection of the CO(3-2) molecular emission line with the Large Millimetre Telescope's Redshift Search Receiver and through [OIII] and H-alpha line detections in the near-infrared from Subaru/IRCS. We have resolved the radio emission with high resolution (300-400 mas) eMERLIN L-band and JVLA C-band imaging. These observations are used in combination with the near-...

Geach, J E; Verma, A; Marshall, P J; Jackson, N; Belles, P -E; Beswick, R; Baeten, E; Chavez, M; Cornen, C; Cox, B E; Erben, T; Erickson, N J; Garrington, S; Harrison, P A; Harrington, K; Hughes, D H; Ivison, R J; Jordan, C; Lin, Y -T; Leauthaud, A; Lintott, C; Lynn, S; Kapadia, A; Kneib, J -P; Macmillan, C; Makler, M; Miller, G; Montana, A; Mujica, R; Muxlow, T; Narayanan, G; Briain, D O; O'Brien, T; Oguri, M; Paget, E; Parrish, M; Ross, N P; Rozo, E; Rusu, E; Rykoff, E S; Sanchez-Arguelles, D; Simpson, R; Snyder, C; Schloerb, F P; Tecza, M; Van Waerbeke, L; Wilcox, J; Viero, M; Wilson, G W; Yun, M S; Zeballos, M

2015-01-01T23:59:59.000Z

322

Hilbert's Sixth Problem: Descriptive Statistics as New Foundations for Probability  

E-Print Network [OSTI]

Hay esbozas tras las cuales las probabilidades se cuentan como la fundaci\\'on de la teor\\'\\i a matem\\'atica de las estad\\'\\i sticas. Mas la significaci\\'on f\\'\\i sica de las probabilidades matem\\'aticas son oscuros, muy poco entendidos. Parecer\\'\\i a mejor que las probabilidades f\\'\\i sicas sean fundadas en las estad\\'\\i sticas descriptivas de datos fisicales. Se trate una teor\\'\\i a que as\\'\\i responde a una cuestiona de Hilbert propuesta en su Problema N\\'umero Seis, la axiomatizaci\\'on de la F\\'\\i sica. Est\\'a basada en la auto-correlaci\\'on de los series temporales. Casi todas de las funciones de auto-correlaci\\'on de las trayector\\'\\i as de un sistema din\\'amico lineal (de lo cual el n\\'umero de sus grados de libertad sea bastante grande) son todas aproximadamente iguales, no importan las condiciones iniciales, a\\'un si el sistema no sea erg\\'odico, como conjetur\\'o Khintchine en 1943. Usually, the theory of probability has been made the foundation for the theory of statistics. But the physical significa...

Johnson, Joseph F

2014-01-01T23:59:59.000Z

323

TESTING THE HYPOTHESIS THAT METHANOL MASER RINGS TRACE CIRCUMSTELLAR DISKS: HIGH-RESOLUTION NEAR-INFRARED AND MID-INFRARED IMAGING  

SciTech Connect (OSTI)

Milliarcsecond very long baseline interferometry maps of regions containing 6.7 GHz methanol maser emission have lead to the recent discovery of ring-like distributions of maser spots and the plausible hypothesis that they may be tracing circumstellar disks around forming high-mass stars. We aimed to test this hypothesis by imaging these regions in the near- and mid-infrared at high spatial resolution and compare the observed emission to the expected infrared morphologies as inferred from the geometries of the maser rings. In the near-infrared we used the Gemini North adaptive optics system of ALTAIR/NIRI, while in the mid-infrared we used the combination of the Gemini South instrument T-ReCS and super-resolution techniques. Resultant images had a resolution of {approx}150 mas in both the near-infrared and mid-infrared. We discuss the expected distribution of circumstellar material around young and massive accreting (proto)stars and what infrared emission geometries would be expected for the different maser ring orientations under the assumption that the masers are coming from within circumstellar disks. Based upon the observed infrared emission geometries for the four targets in our sample and the results of spectral energy distribution modeling of the massive young stellar objects associated with the maser rings, we do not find compelling evidence in support of the hypothesis that methanol masers rings reside in circumstellar disks.

De Buizer, James M. [Stratospheric Observatory for Infrared Astronomy-USRA, NASA Ames Research Center, MS N232-12, Moffett Field, CA 94035 (United States); Bartkiewicz, Anna; Szymczak, Marian, E-mail: jdebuizer@sofia.usra.edu [Torun Centre for Astronomy, Nicolaus Copernicus University, Gagarina 11, 87-100 Torun (Poland)

2012-08-01T23:59:59.000Z

324

AN ASTROMETRIC SEARCH FOR A SUB-STELLAR COMPANION OF THE M8.5 DWARF TVLM 51346546 USING VERY LONG BASELINE INTERFEROMETRY  

SciTech Connect (OSTI)

We conducted multi-epoch very long baseline interferometry observations to search for astrometric reflex motion that would be caused by a sub-stellar companion of the M8.5 dwarf TVLM 51346546. The observations yield an absolute parallax corresponding to a distance of 10.762 0.027 pc and a proper motion of 78.09 0.17 mas yr{sup 1}. The averaged flux density per epoch varies by a factor of at least three. From the absence of significant residual motion, we place an upper limit on any reflex motion caused by a companion, extending the parameter space covered by previous near-infrared direct-imaging searches. The data exclude a phase space of companion masses and orbital periods ranging from 3.8 M{sub Jup} with an orbital radius of ?0.05 AU (and an orbital period of 16 days) to 0.3 M{sub Jup} with an orbital radius of ?0.7 AU (and an orbital period of 710 days)

Forbrich, Jan; Berger, Edo; Reid, Mark J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

2013-11-01T23:59:59.000Z

325

A New Merging Double Degenerate Binary in the Solar Neighborhood  

E-Print Network [OSTI]

Characterizing the local space density of double degenerate binary systems is a complementary approach to broad sky surveys of double degenerates to determine the expected rates of white dwarf binary mergers, in particular those that may evolve into other observable phenomena such as extreme helium stars, Am CVn systems, and supernovae Ia. However, there have been few such systems detected in local space. We report here the discovery that WD 1242$-$105, a nearby bright WD, is a double-line spectroscopic binary consisting of two degenerate DA white dwarfs of similar mass and temperature, despite it previously having been spectroscopically characterized as a single degenerate. Follow-up photometry, spectroscopy, and trigonometric parallax have been obtained in an effort to determine the fundamental parameters of each component of this system. The binary has a mass ratio of 0.7 and a trigonometric parallax of 25.5 mas, placing it at a distance of 39 pc. The system's total mass is 0.95 M$_\\odot$ and has an orbita...

Debes, John H; Tremblay, Pier-Emmanuel; Lpez-Morales, Mercedes; Anglada-Escud, Guillem; Napiwotzki, Ralf; Osip, David; Weinberger, Alycia

2015-01-01T23:59:59.000Z

326

Advance Resource Provisioning in Bulk Data Scheduling  

SciTech Connect (OSTI)

Today?s scientific and business applications generate mas- sive data sets that need to be transferred to remote sites for sharing, processing, and long term storage. Because of increasing data volumes and enhancement in current net- work technology that provide on-demand high-speed data access between collaborating institutions, data handling and scheduling problems have reached a new scale. In this paper, we present a new data scheduling model with ad- vance resource provisioning, in which data movement operations are defined with earliest start and latest comple- tion times. We analyze time-dependent resource assign- ment problem, and propose a new methodology to improve the current systems by allowing researchers and higher-level meta-schedulers to use data-placement as-a-service, so they can plan ahead and submit transfer requests in advance. In general, scheduling with time and resource conflicts is NP-hard. We introduce an efficient algorithm to organize multiple requests on the fly, while satisfying users? time and resource constraints. We successfully tested our algorithm in a simple benchmark simulator that we have developed, and demonstrated its performance with initial test results.

Balman, Mehmet

2012-10-01T23:59:59.000Z

327

Discovery of an Unbound Hyper-Velocity Star in the Milky Way Halo  

E-Print Network [OSTI]

We have discovered a star, SDSS J090745.0+024507, leaving the Galaxy with a heliocentric radial velocity of +853+-12 km/s, the largest velocity ever observed in the Milky Way halo. The star is either a hot blue horizontal branch star or a B9 main sequence star with a heliocentric distance ~55 kpc. Corrected for the solar reflex motion and to the local standard of rest, the Galactic rest-frame velocity is +709 km/s. Because its radial velocity vector points 173.8 deg from the Galactic center, we suggest that this star is the first example of a hyper-velocity star ejected from the Galactic center as predicted by Hills and later discussed by Yu & Tremaine. The star has [Fe/H]~0, consistent with a Galactic center origin, and a travel time of <80 Myr from the Galactic center, consistent with its stellar lifetime. If the star is indeed traveling from the Galactic center, it should have a proper motion of 0.3 mas/yr observable with GAIA. Identifying additional hyper-velocity stars throughout the halo will constrain the production rate history of hyper-velocity stars at the Galactic center.

Warren R. Brown; Margaret J. Geller; Scott J. Kenyon; Michael J. Kurtz

2005-01-11T23:59:59.000Z

328

VLBI OBSERVATIONS OF THE TYPE I b/c SUPERNOVA 2009bb  

SciTech Connect (OSTI)

We report on VLBI as well as Very Large Array radio observations of the Type I b/c supernova 2009bb. The high radio luminosity of this supernova seems to require relativistic outflow, implying that the early radio emission was 'engine-driven', that is, driven by collimated outflow from a compact object, even though no gamma-ray emission was seen. The radio light curve shows a general decline, with a 'bump' near t = 52 d, seen most prominently at 5 GHz. The light-curve bump could be either engine-driven or it might represent the turn-on of the normal radio emission from a supernova, driven by interaction with the circumstellar material rather than by the engine. We undertook VLBI observations to resolve SN 2009bb's relativistic outflow. Our observations constrain the angular outer radius at an age of 85 d to be <0.64 mas, corresponding to <4 x 10{sup 17} cm and an average apparent expansion speed of <1.74 c. This result is consistent with the moderately relativistic ejecta speeds implied by the radio luminosity and spectrum.

Bietenholz, M. F. [Hartebeesthoek Radio Observatory, P.O. Box 443, Krugersdorp, 1740 (South Africa); Soderberg, A. M. [Harvard-Smithsonian Center for Astrophysics, Theory Division, 60 Garden Street, Cambridge, MA 02138 (United States); Bartel, N. [Department of Physics and Astronomy, York University, Toronto, M3J 1P3, Ontario (Canada); Ellingsen, S. P. [School of Mathematics and Physics, University of Tasmania, Hobart, Tasmania (Australia); Horiuchi, S. [Canberra Deep Space Communication Complex, P.O. Box 1035, Tuggeranong, ACT 2901 (Australia); Phillips, C. J.; Tzioumis, A. K.; Wieringa, M. H. [Australia Telescope National Facility, Epping NSW (Australia); Chugai, N. N. [Institute of Astronomy, RAS, Pyatnitskaya 48, Moscow 119017 (Russian Federation)

2010-12-10T23:59:59.000Z

329

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

SciTech Connect (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

330

SiO MASERS IN ASYMMETRIC MIRAS. III. IK TAURI  

SciTech Connect (OSTI)

This is the third paper in a series of multi-epoch observations at 7 mm wavelength of the SiO masers in several asymptotic giant branch stars from a sample of Mira variable stars showing evidence of asymmetric structure in the infrared. These stars have been observed interferometrically in the infrared by Infrared Optical Telescope Array and with Very Long Baseline Array measurements of the SiO masers. In this paper, we present the observations of IK Tauri (IK Tau). There is a persistent elliptical distribution of the masers around the star {approx}40 x {approx}30 mas in size with a major axis at position angle {approx}30 deg. The SiO masers in the circumstellar envelope exhibit large-scale systematic motions which reverse direction on timescales of a decade, roughly the interval between the ejections of dust shells. The orientations on the sky of the apparent rotation-like bulk motion and of the major axis of the maser ellipse differ by 37 deg. (2.5{sigma}) making any relationship uncertain. The systemic velocity of IK Tau is estimated to be 33.3 {+-} 1.0 km s{sup -1}. A comparison is made with the model calculations of Gray et al. which predict some but not all observed features.

Cotton, W. D. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903-2475 (United States); Ragland, S. [W. M. Keck Observatory, 65-1120 Mamalahoa Hwy, Kamuela, HI 96743 (United States); Pluzhnik, E. A. [NASA-Ames Research Center, Moffett Field, CA 94035 (United States); Danchi, W. C. [NASA Goddard Space Flight Center, Exoplanets and Stellar Astrophysics, Code 667, Greenbelt, MD 20771 (United States); Traub, W. A. [Jet Propulsion Laboratory, California Institute of Technology, M/S 301-451, 4800 Oak Grove Dr., Pasadena, CA 91109 (United States); Willson, L. A. [Department of Physics and Astronomy, Iowa State University, Ames, IA 50014 (United States); Lacasse, M. G. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)], E-mail: bcotton@nrao.edu

2010-03-01T23:59:59.000Z

331

Radio Synchrotron Emission from a Bow Shock around the Gas Cloud G2 Heading toward the Galactic Center  

E-Print Network [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 June 2013, 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_p ~ 5400 km/s. 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 ~33 mas. Interferometric observations cou...

Narayan, Ramesh; Sironi, Lorenzo

2012-01-01T23:59:59.000Z

332

Synthesis and nano-mechanical characterization of calcium-silicate-hydrate (C-S-H) made with 1.5 CaO/SiO{sub 2} mixture  

SciTech Connect (OSTI)

In this study, calcium silicate hydrate (C-S-H) is synthesized and characterized. C-S-H slurry was made with calcium oxide (CaO) to micro-silica (SiO{sub 2}) mixture ratio of 1.5 and enough deionized water. The slurry was continuously mixed for 7 days, then the excess water was removed. Two methods of drying were implemented: one method used the standard d-dry technique and the other was equilibrated to 11% relative humidity (RH). The dried powders were characterized using thermo gravimetric analysis (TGA), X-ray diffraction analysis (XRDA), and {sup 29}Si magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy. The stoichiometric formulas of synthetic C-S-H powders dried to d-dry and 11% RH in this study were approximated as C{sub 1.2}SH{sub 0.7} and C{sub 1.2}SH{sub 2.4} respectively. The powders were then compacted to create specimens with porosities similar to C-S-H in hydrated cement. The specimens underwent nanoindentation to mechanically characterize C-S-H. The experiments provide insight on the nanoscale mechanical characteristics of C-S-H.

Foley, Emmy M. [Arizona Public Service, Wintersburg, AZ 85354 (United States)] [Arizona Public Service, Wintersburg, AZ 85354 (United States); Kim, Jung J. [Department of Civil and Environmental Engineering, Sejong University, Seoul 143-747 (Korea, Republic of)] [Department of Civil and Environmental Engineering, Sejong University, Seoul 143-747 (Korea, Republic of); Reda Taha, M.M., E-mail: mrtaha@unm.edu [Department of Civil Engineering, MSC01 1070, 1 University of New Mexico, Albuquerque, NM 87131-0001 (United States)

2012-09-15T23:59:59.000Z

333

Deteriorated hardened cement paste structure analyzed by XPS and {sup 29}Si NMR techniques  

SciTech Connect (OSTI)

In this report, X-ray photoelectron spectroscopy (XPS) and {sup 29}Si-MAS-NMR was used for the evaluation of deteriorated hardened cement pastes. The deterioration by ammonium nitrate solution was accompanied by changes in the pore structure as well as by structural changes in the CSH in the hardened cement paste. The CaO/SiO{sub 2} ratio of the CSH decreased with the progress of deterioration, there was also polymerization of the silicate in the CSH. It was confirmed that the degree of polymerization of silicate of the CSH in hardened cement paste can be determined by XPS. It was also shown that the polymerization depends on the structure of the CSH. -- Highlights: The polymerization of silicate of the CSH in the HCP can be observed by XPS. The structure of CSH changed with the degree of calcium leaching. The NMR result about silicate in CSH was in good agreement with the XPS result.

Kurumisawa, Kiyofumi, E-mail: kurumi@eng.hokudai.ac.jp [Faculty of Engineering, Hokkaido University, Japan, Kita 13, Nishi 8, Kita-ku, Sapporo, Hokkaido 060-8628 (Japan)] [Faculty of Engineering, Hokkaido University, Japan, Kita 13, Nishi 8, Kita-ku, Sapporo, Hokkaido 060-8628 (Japan); Nawa, Toyoharu [Faculty of Engineering, Hokkaido University, Japan, Kita 13, Nishi 8, Kita-ku, Sapporo, Hokkaido 060-8628 (Japan)] [Faculty of Engineering, Hokkaido University, Japan, Kita 13, Nishi 8, Kita-ku, Sapporo, Hokkaido 060-8628 (Japan); Owada, Hitoshi [Radioactive Waste Management Funding and Research Center, 1-15-7 Tsukishima, Chuo-ku, Tokyo (Japan)] [Radioactive Waste Management Funding and Research Center, 1-15-7 Tsukishima, Chuo-ku, Tokyo (Japan); Shibata, Masahito [Taiheiyo Consultant Co., Ltd., 2-4-2, Ohsaku, Sakura-City, Chiba (Japan)] [Taiheiyo Consultant Co., Ltd., 2-4-2, Ohsaku, Sakura-City, Chiba (Japan)

2013-10-15T23:59:59.000Z

334

La frontera a alto corrimiento al rojo: historia de la formacio'n de las galaxias  

E-Print Network [OSTI]

This review presents a brief discussion of the theory of Cold Dark Matter of structure formation in the universe, describing the main processes determining the power spectrum, the non-linear gravitational collapse, the formation of galaxies and the evolution of the intergalactic medium. Recent advances in the observations of high redshift galaxies, and their interpretation in the context of this theory, are then summarized. Este art\\'\\i culo de revisi\\'on presenta una breve exposici\\'on de la teor\\'\\i a de la Materia Invisible Fr\\'\\i a de la formaci\\'on de estructura en el universo, describiendo los procesos m\\'as importantes que determinan el espectro de potencia, el colapso gravitatorio no lineal, la formaci\\'on de galaxias y la evoluci\\'on del medio intergal\\'actico. Resumimos tambi\\'en los avances recientes en las observaciones de galaxias a alto corrimiento al rojo, y la interpretaci\\'on en el contexto de esa teor\\'\\i a.

Jordi Miralda-Escude

1999-10-29T23:59:59.000Z

335

The nature and fate of natural resins in the geosphere - VIII - NMR and Py-GC-MS characterization of soluble labdanoid polymers isolated from holocene class I resins.  

SciTech Connect (OSTI)

Soluble polylabdanoids isolated by sequential solvent extraction have been characterized by liquid-state {sup 13}C- and {sup 1}H NMR and {sup 13}C-{sup 1}H HMQC (heteronuclear correlation) NMR spectroscopy in addition to solid-state NMR and Py-GC-MS techniques. Two Holocene resins originating from Santander, Colombia and Mombasa, Kenya were analyzed. Soluble polymers were isolated by extraction with a 1:1 (v/v) methylene chloride-methanol mixture following sequential extractions with methylene chloride and methanol. The molecular weight of polymer extracts was shown by GPC analyses to exceed that of non-polymeric occluded terpenoids. Py-GC-MS, solid-state {sup 13}C CP/MAS and {sup 13}C cross-polarization/depolarization NMR spectroscopy results indicated that chemical compositions of soluble polymers isolated from immature resins are highly representative of the structure of corresponding insoluble polymers, i.e. polylabdatrienes. These data provide evidence for cross-linking or cyclization of side-chain olefinic carbons during or shortly after polymerization. Generally, the characterization of soluble resin polymers by liquid-state NMR spectroscopy has proven to be an excellent means for investigating the maturation mechanism of polylabdanoid resinites, and has potential for furthering the application of Class I resinites as geothermal indicators.

Clifford, D. J.; Hatcher, P. G.; Botto, R. E.; Muntean, J. V.; Michaels, B.; Anderson, K. B.; Chemistry; Pennsylvania State Univ.; Amoco Oil Co.

1997-01-01T23:59:59.000Z

336

Advanced slow-magic angle spinning probe for magnetic resonance imaging and spectroscopy  

DOE Patents [OSTI]

The present invention relates to a probe and processes useful for magnetic resonance imaging and spectroscopy instruments. More particularly, the invention relates to a MR probe and processes for obtaining resolution enhancements of fluid objects, including live specimens, using an ultra-slow (magic angle) spinning (MAS) of the specimen combined with a modified phase-corrected magic angle turning (PHORMAT) pulse sequence. Proton NMR spectra were measured of the torso and the top part of the belly of a female BALBc mouse in a 2T field, while spinning the animal at a speed of 1.5 Hz. Results show that even in this relatively low field with PHORMAT, an isotropic spectrum is obtained with line widths that are a factor 4.6 smaller than those obtained in a stationary mouse. Resolution of 1H NMR metabolite spectra are thus significantly enhanced. Results indicate that PHORMAT has the potential to significantly increase the utility of 1H NMR spectroscopy for in vivo biochemical, biomedical and/or medical applications involving large-sized biological objects such as mice, rats and even humans within a hospital setting. For small-sized objects, including biological objects, such as excised tissues, organs, live bacterial cells, and biofilms, use of PASS at a spinning rate of 30 Hz and above is preferred.

Wind, Robert A.; Hu, Jian Zhi; Minard, Kevin R.; Rommereim, Donald N.

2006-01-24T23:59:59.000Z

337

Circumstellar material in the Vega inner system revealed by CHARA/FLUOR  

E-Print Network [OSTI]

Only a handful of debris disks have been imaged up to now. Due to the need for high dynamic range and high angular resolution, very little is known about the inner planetary region, where small amounts of warm dust are expected to be found. We investigate the close neighbourhood of Vega with the help of infrared stellar interferometry and estimate the integrated K-band flux originating from the central 8 AU of the debris disk. We performed precise visibility measurements at both short (~30 m) and long (~150 m) baselines with the FLUOR beam-combiner installed at the CHARA Array (Mt Wilson, California) in order to separately resolve the emissions from the extended debris disk (short baselines) and from the stellar photosphere (long baselines). After revising Vega's K-band angular diameter (3.202+/-0.005 mas), we show that a significant deficit in squared visibility (1.88+/-0.34%) is detected at short baselines with respect to the best-fit uniform disk stellar model. This deficit can be either attributed to the ...

Absil, O; Augereau, J C; Berger, D H; Brummelaar, T A; Folco, E; Foresto, V C; Kervella, P; McAlister, H A; Merand, A; Ridgway, S T; Sturmann, J; Sturmann, L; Turner, N H

2006-01-01T23:59:59.000Z

338

MOJAVE. X. PARSEC-SCALE JET ORIENTATION VARIATIONS AND SUPERLUMINAL MOTION IN ACTIVE GALACTIC NUCLEI  

SciTech Connect (OSTI)

We describe the parsec-scale kinematics of 200 active galactic nucleus (AGN) jets based on 15 GHz Very Long Baseline Array (VLBA) data obtained between 1994 August 31 and 2011 May 1. We present new VLBA 15 GHz images of these and 59 additional AGNs from the MOJAVE and 2 cm Survey programs. Nearly all of the 60 most heavily observed jets show significant changes in their innermost position angle over a 12-16 yr interval, ranging from 10 to 150 on the sky, corresponding to intrinsic variations of ?0.5 to ?2. The BL Lac jets show smaller variations than quasars. Roughly half of the heavily observed jets show systematic position angle trends with time, and 20 show indications of oscillatory behavior. The time spans of the data sets are too short compared to the fitted periods (5-12 yr), however, to reliably establish periodicity. The rapid changes and large jumps in position angle seen in many cases suggest that the superluminal AGN jet features occupy only a portion of the entire jet cross section and may be energized portions of thin instability structures within the jet. We have derived vector proper motions for 887 moving features in 200 jets having at least five VLBA epochs. For 557 well-sampled features, there are sufficient data to additionally study possible accelerations. We find that the moving features are generally non-ballistic, with 70% of the well-sampled features showing either significant accelerations or non-radial motions. Inward motions are rare (2% of all features), are slow (<0.1 mas yr{sup 1}), are more prevalent in BL Lac jets, and are typically found within 1 mas of the unresolved core feature. There is a general trend of increasing apparent speed with distance down the jet for both radio galaxies and BL Lac objects. In most jets, the speeds of the features cluster around a characteristic value, yet there is a considerable dispersion in the distribution. Orientation variations within the jet cannot fully account for the dispersion, implying that the features have a range of Lorentz factor and/or pattern speed. Very slow pattern speed features are rare, comprising only 4% of the sample, and are more prevalent in radio galaxy and BL Lac jets. We confirm a previously reported upper envelope to the distribution of speed versus beamed luminosity for moving jet features. Below 10{sup 26} W Hz{sup 1} there is a fall-off in maximum speed with decreasing 15 GHz radio luminosity. The general shape of the envelope implies that the most intrinsically powerful AGN jets have a wide range of Lorentz factors up to ?40, while intrinsically weak jets are only mildly relativistic.

Lister, M. L.; Richards, J. L. [Department of Physics, Purdue University, 525 Northwestern Avenue, West Lafayette, IN 47907 (United States); Aller, M. F.; Aller, H. D. [Department of Astronomy, University of Michigan, 817 Dennison Building, Ann Arbor, MI 48109 (United States); Homan, D. C. [Department of Physics, Denison University, Granville, OH 43023 (United States); Kellermann, K. I. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States); Kovalev, Y. Y. [Astro Space Center of Lebedev Physical Institute, Profsoyuznaya 84/32, 117997 Moscow (Russian Federation); Pushkarev, A. B.; Ros, E.; Savolainen, T., E-mail: mlister@purdue.edu [Max-Planck-Institut fr Radioastronomie, Auf dem Hgel 69, D-53121 Bonn (Germany)

2013-11-01T23:59:59.000Z

339

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)  

SciTech Connect (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

340

DISCOVERY, PROGENITOR AND EARLY EVOLUTION OF A STRIPPED ENVELOPE SUPERNOVA iPTF13bvn  

SciTech Connect (OSTI)

The intermediate Palomar Transient Factory reports our discovery of a young supernova, iPTF13bvn, in the nearby galaxy, NGC 5806 (22.5 Mpc). Our spectral sequence in the optical and infrared suggests a Type Ib classification. We identify a blue progenitor candidate in deep pre-explosion imaging within a 2? error circle of 80 mas (8.7 pc). The candidate has an M{sub B} luminosity of 5.52 0.39 mag and a B I color of 0.25 0.25 mag. If confirmed by future observations, this would be the first direct detection for a progenitor of a Type Ib. Fitting a power law to the early light curve, we find an extrapolated explosion date around 0.6 days before our first detection. We see no evidence of shock cooling. The pre-explosion detection limits constrain the radius of the progenitor to be smaller than a few solar radii. iPTF13bvn is also detected in centimeter and millimeter wavelengths. Fitting a synchrotron self-absorption model to our radio data, we find a mass-loading parameter of 1.310{sup 12} g cm{sup 1}. Assuming a wind velocity of 10{sup 3} km s{sup 1}, we derive a progenitor mass-loss rate of 3 10{sup 5} M {sub ?} yr{sup 1}. Our observations, taken as a whole, are consistent with a Wolf-Rayet progenitor of the supernova iPTF13bvn.

Cao, Yi; Horesh, Assaf; Kulkarni, S. R. [Astronomy Department, California Institute of Technology, 1200 E. California Boulevard, Pasadena, CA 91125 (United States)] [Astronomy Department, California Institute of Technology, 1200 E. California Boulevard, Pasadena, CA 91125 (United States); Kasliwal, Mansi M. [The Observatories, Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States)] [The Observatories, Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Arcavi, Iair; Gal-Yam, Avishay; Gorbikov, Evgeny; Ofek, Eran O.; Yaron, Ofer [Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot 76100 (Israel)] [Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot 76100 (Israel); Hancock, Paul [Sydney Institute for Astronomy (SIfA), School of Physics, The University of Sydney, NSW 2006 (Australia)] [Sydney Institute for Astronomy (SIfA), School of Physics, The University of Sydney, NSW 2006 (Australia); Valenti, Stefano; Graham, Melissa; Howell, D. Andrew [Las Cumbres Observatory Global Telescope Network, Goleta, CA 93117 (United States)] [Las Cumbres Observatory Global Telescope Network, Goleta, CA 93117 (United States); Cenko, S. Bradley [Astrophysics Science Division, NASA Goddard Space Flight Center, Mail Code 661, Greenbelt, MD 20771 (United States)] [Astrophysics Science Division, NASA Goddard Space Flight Center, Mail Code 661, Greenbelt, MD 20771 (United States); Sand, David [Department of Physics, Texas Tech University, Lubbock, TX 79409 (United States)] [Department of Physics, Texas Tech University, Lubbock, TX 79409 (United States); Silverman, Jeffrey M.; Wheeler, J. Craig; Marion, G. H. [Department of Astronomy, University of Texas at Austin, Austin, TX 78712 (United States)] [Department of Astronomy, University of Texas at Austin, Austin, TX 78712 (United States); Walker, Emma S. [Department of Physics, Yale University, New Haven, CT 06511-8499 (United States)] [Department of Physics, Yale University, New Haven, CT 06511-8499 (United States); Mazzali, Paolo, E-mail: ycao@astro.caltech.edu [INAF-Padova Astronomical Observatory, Vicolo dell'Osservatorio 5, I-35122 Padova (Italy)] [INAF-Padova Astronomical Observatory, Vicolo dell'Osservatorio 5, I-35122 Padova (Italy); and others

2013-09-20T23:59:59.000Z

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341

Temperature effects on chemical structure and motion in coal. Final report  

SciTech Connect (OSTI)

The objective of this project was to apply recently developed, state-of-the-art nuclear magnetic resonance (NMR) techniques to examine in situ changes in the chemical structure and molecular/macromolecular motion in coal as the temperature is increased above room temperature. Although alterations in the chemical structure of coal have been studied previously by {sup 13}C NMR, using quenched samples, the goal of this project was to examine these chemical structural changes, and changes in molecular/macromolecular mobility that may precede or accompany the chemical changes, at elevated temperatures, using modern {sup 13}C and {sup 1}H NMR techniques, especially {sup 1}H dipolar-dephasing techniques and related experiments pioneered in the laboratory for examining pyridine-saturated coals. This project consisted of the following four primary segments and related efforts on matters relevant to the first four tasks. (1) {sup 1}H NMR characterization of coal structure and mobility as a function of temperature variation over a temperature range (30--240 C) for which substantial chemical transformations were not anticipated. (2) {sup 1}H NMR characterization of coal structure, mobility and conversion as a function of temperature variation over a temperature range (240--500 C) for which chemical transformations of coal are known to occur. (3) {sup 13}C NMR investigation of coal structure/mobility as a function of temperature over a temperature range (30--240 C) for which substantial chemical transformations were not anticipated. (4) {sup 13}C NMR investigation of coal structure, dynamics and conversion as a function of temperature variation over a range (240--500 C) for which chemical transformations of coal are known to occur. (5) Related matters relevant to the first four tasks: (a) {sup 1}H CRAMPS NMR characterization of oil shales and their kerogen concentrates; and (b) improved quantitation in {sup 13}C MAS characterization of coals.

Maciel, G.E.

1996-09-30T23:59:59.000Z

342

Charge Compensation in RE3+ (RE = Eu, Gd) and M+ (M = Li, Na, K) Co-Doped Alkaline Earth Nanofluorides Obtained by Microwave Reaction with Reactive Ionic Liquids Leading to Improved Optical Properties  

SciTech Connect (OSTI)

Alkaline earth fluorides are extraordinarily promising host matrices for phosphor materials with regard to rare earth doping. In particular, quantum cutting materials, which might considerably enhance the efficiency of mercury-free fluorescent lamps or SC solar cells, are often based on rare earth containing crystalline fluorides such as NaGdF4, GdF3 or LaF3. Substituting most of the precious rare earth ions and simultaneously retaining the efficiency of the phosphor is a major goal. Alkaline earth fluoride nanoparticles doped with trivalent lanthanide ions (which are required for the quantum cutting phenomenon) were prepared via a microwave assisted method in ionic liquids. As doping trivalent ions into a host with divalent cations requires charge compensation, this effect was thoroughly studied by powder X-ray and electron diffraction, luminescence spectroscopy and 23Na, 139La and 19F solid state NMR spectroscopy. Monovalent alkali ions were codoped with the trivalent lanthanide ions to relieve stress and achieve a better crystallinity and higher quantum cutting abilities of the prepared material. 19F-magic angle spinning (MAS)-NMR-spectra, assisted by 19F{23Na} rotational echo double resonance (REDOR) studies, reveal distinct local fluoride environments, the populations of which are discussed in relation to spatial distribution and clustering models. In the co-doped samples, fluoride species having both Na+ and La3+ ions within their coordination sphere can be identified and quantified. This interplay of mono- and trivalent ions in the CaF2 lattice appears to be an efficient charge compensation mechanism that allows for improved performance characteristics of such co-doped phosphor materials.

Lorbeer, C [Ruhr-Universitat Bochum; Behrends, F [Westfalische Wilhelsm-Universitat Munster; Cybinska, J [Ruhr Universitat Bochum; Eckert, H [Westfalische Wilhelsm-Universitat Munster; Mudring, Anja -V [Ames Laboratory

2014-01-01T23:59:59.000Z

343

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

SciTech Connect (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

344

Coal liquefaction process streams characterization and evaluation: An analytical characterization case study  

SciTech Connect (OSTI)

Deactivation of the second-stage supported catalyst dominated most of the properties over the course of the run. Consequences of increased catalyst age were increases in aromaticity and phenolic -OH concentration and decreases in hydrogen donor content and paraffinic hydrogen content in most process streams, including product distillates. Donor solvent quality of the whole PFL increased through the early part of the run until Period 8 when it apparently stabilized. The properties of the net product oil and its distillate fractions, as determined by NIPER, show that the coal-derived material has some desirable qualities. The whole crude has a low sulfur content and boils below the maximum temperature allowed for the production of transportation fuels. The naphtha fraction (IBP-380{degrees}F) is highly naphthenic and has a low benzene content. The naphtha fraction appears to be amenable to mild hydrotreating to produce a good gasoline blendstock. The kerosene (380--510{degrees}F) fraction is much too cyclic for use as aviation fuel and it is recommended that this fraction be distributed into the two cuts on either end of it (diesel and gasoline feedstocks). The 510--680{degrees}F fraction met most specifications as a heating fuel and diesel fuel. It appears that this material, after moderate hydroprocessing, could make a good diesel blendstock. Both the FIMS and CP/MAS {sup 13}C-NMR methods, currently being used to analyze the suite of twelve samples from HRI Run CC-15, are expected to provide chemical/molecular information to augment and extend the information provided by the base analyses. Preliminary information is encouraging.

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

1993-12-31T23:59:59.000Z

345

Surfactant-assisted synthesis of hybrid lithium iron phosphate nanoparticles for enhancing electrochemical performance  

SciTech Connect (OSTI)

Hybrid nanoparticles of LiFePO{sub 4} with carbon and lithium phosphates were synthesized through organic-inorganic co-assembly procedure using a triblock copolymer (F108 or P123). We found that the triblock copolymers play a critical role in controlling size of hybrid particle and the degree of crystallinity of the inorganic nanostructures. The hybrid using P-123 had more graphitic carbon which resulted in fast electron mobility. Also, magic angle spinning nuclear magnetic resonance (MAS-NMR) revealed that the crystallinity of the hybrid using P123 is higher than that using F108 which is not measurable in X-ray diffraction. Electrochemical performance of the hybrid using P123 as a cathode material in Li-ion batteries showed superior rate capability at 20 C of charging rate and 2 C of discharging rate without capacity loss, in which discharge capacity was 102 mAh/g. - Graphical abstract: Hybrid nanoparticles were synthesized through organic-inorganic co-assembly based on synthetic procedure of mesoporous materials. P123-LFP showed superior high-rate capability at a 20 C charging rate and 2 C discharging rate without capacity loss in Li-ion battery. Highlights: Black-Right-Pointing-Pointer LiFePO{sub 4} nanohybrids are synthesized through the organic-inorganic co-assembly method. Black-Right-Pointing-Pointer Copolymers (F108 or P123) serve as structure directing agents and a carbon source. Black-Right-Pointing-Pointer P123 produces more graphitic carbon and higher crystalline nanohybrids. Black-Right-Pointing-Pointer Nanohybrids using P123 show superior rate capability in Li-ion battery.

Min Kim, Jung [Division of Materials Science, Korea Basic Science Institute (KBSI), Daejeon 305-806 (Korea, Republic of); Yi, Gi-Ra [Department of Polymer Science and Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Chang Lee, Soon; Moon Lee, Sang; Jo, Younghun [Division of Materials Science, Korea Basic Science Institute (KBSI), Daejeon 305-806 (Korea, Republic of); Kang, Hyun-Wook [Graduate School of Analytical Science and Technology (GRAST), Chungnam National University, Daejeon 305-764 (Korea, Republic of); Lee, Gaehang, E-mail: ghlee@kbsi.re.kr [Division of Materials Science, Korea Basic Science Institute (KBSI), Daejeon 305-806 (Korea, Republic of); Jin Kim, Hae, E-mail: hansol@kbsi.re.kr [Division of Materials Science, Korea Basic Science Institute (KBSI), Daejeon 305-806 (Korea, Republic of); Graduate School of Analytical Science and Technology (GRAST), Chungnam National University, Daejeon 305-764 (Korea, Republic of)

2013-01-15T23:59:59.000Z

346

Nickel alloy stud bolts failure: A case history  

SciTech Connect (OSTI)

High strength and corrosion resistance material as Inconel X-750 has been selected for the seal flange bolts in an off-shore field in Libya, due to its properties at high temperature, needed for compliance with Fire Safe requirements. After 4 years from the production start-up, during a routine maintenance of wellheads, some bolts have been found cracked. The paper deals with all the activities done in order to understand the cause of the failure. In particular failure analysis has been carried out through laboratory investigation, and shop tests have been conducted to confirm the field procedure and determine the tension on the bolts during the installation. The main conclusion was that the bolts failed due to the concurrence of stress (over-torque that means stress level higher than yield one) and corrosion (pit/crevice conditions). This environmentally assisted failure is known as Hydrogen Embrittlement (HE). Test carried out using the same X-mas tree mounted on the platform justifies the assumption that in the field, where the conditions are far from the ideal, it is possible that even when a uniform torque is set, the tensile stress applied to the bolts is not uniform, making the situation critical. From the corrosion side, the failed bolts showed some corrosion points near the cracks, as due to environment in the crevice/pitting conditions required to justify the hydrogen presence (the bolts are not cathodically protected). Fatigue has been demonstrated not to be responsible for the failure. Solutions are recommended which can safely be adopted during the installation and the substitution of bolts on an existing wellhead, which is operative under pressure without shutting in the well, and not impairing the safety operating envelope.

Toffolo, G.; Fassina, P.; Marangoni, M. [AGIP SpA, Milan (Italy); Msallem, A. [AGIP Oil, Tripoli (Libyan Arab Jamahiriya)

1996-12-01T23:59:59.000Z

347

Faint Radio Sources in the NOAO Bootes Field. VLBA Imaging and Optical Identifications  

E-Print Network [OSTI]

As a step toward investigating the parsec-scale properties of faint extragalactic radio sources, the Very Long Baseline Array (VLBA) was used at 5.0 GHz to obtain phase-referenced images of 76 sources in the NOAO Bootes field. These 76 sources were selected from the FIRST catalog to have peak flux densities above 10 mJy at 5 arcsec resolution and deconvolved major diameters of less than 3 arcsec at 1.4 GHz. Fifty-seven of these faint radio sources were identified with accretion-powered radio galaxies and quasars brighter than 25.5 mag in the optical I band. On VLA scales at 1.4 GHz, a measure of the compactness of the faint sources (the ratio of the peak flux density from FIRST to the integrated flux density from the NVSS catalog) spans the full range of possibilites arising from source-resolution effects. Thirty of the faint radio sources, or 39 +9/-7%, were detected with the VLBA at 5.0 GHz with peak flux densities above 6 sigma ~2 mJy at 2 mas resolution. The VLBA detections occur through the full range of compactness ratios. The stronger VLBA detections can themselves serve as phase-reference calibrators, boding well for opening up much of the radio sky to VLBA imaging. For the adopted cosmology, the VLBA resolution correponds to 17 pc or finer. Most VLBA detections are unresolved or slightly resolved but one is diffuse and five show either double or core-jet structures; the properties of these latter six are discussed in detail. Three VLBA detections are unidentified and fainter than 25.5 mag in the optical I band; their properties are highlighted because they likely mark optically-obscured active nuclei at high redshift.

J. M. Wrobel; G. B. Taylor; T. A. Rector; S. T. Myers; C. D. Fassnacht

2005-06-09T23:59:59.000Z

348

Phase transition upon K{sup +} ion exchange into Na-low silica X: Combined NMR and synchrotron X-ray powder diffraction study  

SciTech Connect (OSTI)

The mechanism by which K{sup +} ions exchange into zeolite Na-low silica X (LSX) (Na{sub 96}Al{sub 96}Si{sub 96}O{sub 384}{center_dot}nH{sub 2}O) has ben determined by studying structures of the Na-LSX and K-LSX end members in the Na-K LSX solid solution series as well as samples exchanged at the 20%, 42% and 80% K{sup +} levels. A preliminary investigation using {sup 29}Si MAS NMR spectroscopy revealed a two-phase region in the solid solution near 80% K{sup +} exchange. Rietveld analysis of the powder diffraction data collected from hydrated samples showed that, up to 42% of K{sup +} exchange, K{sup +} ions were located preferentially at site I{prime}, just outside the double 6-ring (D6R) in the sodalite age, and at site II, above the single 6-ring (S6R) in the supercage. Introduction of K{sup +} ions into site I{prime} repositioned Na{sup +} ions into site I, at the center of the D6R. An abrupt change in the cubic lattice parameter from 25.0389(5) to 25.2086(5) {angstrom} marked the formation of a second phase at the 80% K{sup +}-exchange level as K{sup +} ions began to occupy site I. No coexistence of phases was observed for the fully K{sup +}-exchanged sample (a = 25.2486(2) {angstrom}), where sites I and II were fully occupied by K{sup +} ions.

Lee, Y.; Parise, J.B. [State Univ. of New York, Stony Brook, NY (United States)] [State Univ. of New York, Stony Brook, NY (United States); Carr, S.W. [ANSTO, Menai (Australia)] [ANSTO, Menai (Australia)

1998-09-01T23:59:59.000Z

349

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

SciTech Connect (OSTI)

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

350

Discovery of a peculiar Cepheid-like star towards the northern edge of the Small Magellanic Cloud  

E-Print Network [OSTI]

For seven years, the EROS-2 project obtained a mass of photometric data on variable stars. We present a peculiar Cepheid-like star, in the direction of the Small Magellanic Cloud, which demonstrates unusual photometric behaviour over a short time interval. We report on data of the photometry acquired by the MARLY telescope and spectroscopy from the EFOSC instrument for this star, called EROS2 J005135-714459(sm0060n13842), which resembles the unusual Cepheid HR 7308. The light curve of our target is analysed using the Analysis of Variance method to determine a pulsational period of 5.5675 days. A fit of time-dependent Fourier coefficients is performed and a search for proper motion is conducted. The light curve exhibits a previously unobserved and spectacular change in both mean magnitude and amplitude, which has no clear theoretical explanation. Our analysis of the spectrum implies a radial velocity of 104 km s$^{-1}$ and a metallicity of -0.4$\\pm$0.2 dex. In the direction of right ascension, we measure a proper motion of 17.4$\\pm$6.0 mas yr$^{-1}$ using EROS astrometry, which is compatible with data from the NOMAD catalogue. The nature of EROS2 J005135-714459(sm0060n13842) remains unclear. For this star, we may have detected a non-zero proper motion for this star, which would imply that it is a foreground object. Its radial velocity, pulsational characteristics, and photometric data, however, suggest that it is instead a Cepheid-like object located in the SMC. In such a case, it would present a challenge to conventional Cepheid models.

J. B. Marquette; P. Tisserand; P. Francois; J. P. Beaulieu; V. Doublier; E. Lesquoy; A. Milsztajn; J. Pritchard; A. Schwarzenberg-Czerny; C. Afonso; J. N. Albert; J. Andersen; R. Ansari; E. Aubourg; P. Bareyre; X. Charlot; C. Coutures; R. Ferlet; P. Fouque; J. F. Glicenstein; B. Goldman; A. Gould; D. Graff; M. Gros; J. Haissinski; C. Hamadache; J. de Kat; L. Le Guillou; C. Loup; C. Magneville; E. Maurice; A. Maury; M. Moniez; N. Palanque-Delabrouille; O. Perdereau; Y. R. Rahal; J. Rich; M. Spiro; A. Vidal-Madjar; S. Zylberajch

2008-05-29T23:59:59.000Z

351

SU-E-I-18: CT Scanner QA Using Normalized CTDI Ratio  

SciTech Connect (OSTI)

Purpose: To create a ratio of weighted computed tomography dose index (CTDIw) data normalized to in-air measurements (CTDIair) as a function of beam quality to create a look-up table for frequent, rapid quality assurance (QA) checks of CTDI. Methods: The CTDIw values were measured according to TG-63 protocol using a pencil ionization chamber (Unfors Xi CT detector) and head and body Polymethyl methacrylate (PMMA) phantoms (16 and 32 cm diameter, respectively). Single scan dose profiles were measured at each clinically available energy (80,100,120,140 kVp) on three different CT scanners (two Siemens SOMATOM Definition Flash and one GE Optima), using a tube current of 400 mA, a one second rotation time, and the widest available beam width (32 0.6 mm and 16 1.25 mm, respectively). These values were normalized to CTDIair measurements using the same conditions as CTDIw. The ratios (expressed in cGy/R) were assessed for each scanner as a function of each energy's half value layer (HVL) paired with the phantom's appropriate bow tie filter measured in mmAl. Results: Normalized CTDI values vary linearly with HVL for both the head and body phantoms. The ratios for the two Siemens machines are very similar at each energy. Compared to the GE scanner, these values vary between 1020% for each kVp setting. Differences in CTDIair contribute most to the deviation of the ratios across machines. Ratios are independent of both mAs and collimation. Conclusion: Look-up tables constructed of normalized CTDI values as a function of HVL can be used to derive CTDIw data from only three in-air measurements (one for CTDIair and two with added filtration for HVL) to allow for simple, frequent QA checks without CT phantom setup. Future investigations will involve comparing results with Monte Carlo simulations for validation.

Randazzo, M; Tambasco, M; Russell, B [San Diego State University, San Diego, CA (United States)

2014-06-01T23:59:59.000Z

352

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

SciTech Connect (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

353

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

SciTech Connect (OSTI)

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

354

Concurrent Collections (CnC): A new approach to parallel programming  

ScienceCinema (OSTI)

A common approach in designing parallel languages is to provide some high level handles to manipulate the use of the parallel platform. This exposes some aspects of the target platform, for example, shared vs. distributed memory. It may expose some but not all types of parallelism, for example, data parallelism but not task parallelism.This approach must find a balance between the desire to provide a simple view for the domain expert and provide sufficient power for tuning.This is hard for any given architecture and harder if the language is to apply to a range of architectures. Either simplicity or power is lost. Instead of viewing the language design problem as one of providing the programmer with high level handles, we view the problem as one of designing an interface. On one side of this interface is the programmer (domain expert) who knows the application but needs no knowledge of any aspects of the platform. On the other side of the interface is the performance expert (programmer or program) who demands maximal flexibility for optimizing the mapping to a wide range of target platforms (parallel / serial, shared / distributed, homogeneous / heterogeneous, etc.) but needs no knowledge of the domain. Concurrent Collections (CnC) is based on this separation of concerns. The talk will present CnC and its benefits. About the speaker Kathleen Knobe has focused throughout her career on parallelism especially compiler technology, runtime system design and language design. She worked at Compass (aka Massachusetts Computer Associates) from 1980 to 1991 designing compilers for a wide range of parallel platforms for Thinking Machines, MasPar, Alliant, Numerix, and several government projects. In 1991 she decided to finish her education. After graduating from MIT in 1997, she joined Digital Equipment?s Cambridge Research Lab (CRL). She stayed through the DEC/Compaq/HP mergers and when CRL was acquired and absorbed by Intel. She currently works in the Software and Services Group / Technology Pathfinding and Innovation.

None

2011-10-06T23:59:59.000Z

355

Heterogeneous Recycling in Fast Reactors  

SciTech Connect (OSTI)

Current sodium fast reactor (SFR) designs have avoided the use of depleted uranium blankets over concerns of creating weapons grade plutonium. While reducing proliferation risks, this restrains the reactor design space considerably. This project will analyze various blanket and transmutation target configurations that could broaden the design space while still addressing the non-proliferation issues. The blanket designs will be assessed based on the transmutation efficiency of key minor actinide (MA) isotopes and also on mitigation of associated proliferation risks. This study will also evaluate SFR core performance under different scenarios in which depleted uranium blankets are modified to include minor actinides with or without moderators (e.g. BeO, MgO, B4C, and hydrides). This will be done in an effort to increase the sustainability of the reactor and increase its power density while still offering a proliferation resistant design with the capability of burning MA waste produced from light water reactors (LWRs). Researchers will also analyze the use of recycled (as opposed to depleted) uranium in the blankets. The various designs will compare MA transmutation efficiency, plutonium breeding characteristics, proliferation risk, shutdown margins and reactivity coefficients with a current reference sodium fast reactor design employing homogeneous recycling. The team will also evaluate the out-of-core accumulation and/or burn-down rates of MAs and plutonium isotopes on a cycle-by-cycle basis. This cycle-by-cycle information will be produced in a format readily usable by the fuel cycle systems analysis code, VISION, for assessment of the sustainability of the deployment scenarios.

Dr. Benoit Forget; Michael Pope; Piet, Steven J.; Michael Driscoll

2012-07-30T23:59:59.000Z

356

Class B0631+519: Last of the Class Lenses  

SciTech Connect (OSTI)

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,

2005-05-31T23:59:59.000Z

357

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

SciTech Connect (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

358

THE TRENDS HIGH-CONTRAST IMAGING SURVEY. III. A FAINT WHITE DWARF COMPANION ORBITING HD 114174  

SciTech Connect (OSTI)

The nearby Sun-like star HD 114174 exhibits a strong and persistent Doppler acceleration indicating the presence of an unseen distant companion. We have acquired high-contrast imaging observations of this star using NIRC2 at Keck and report the direct detection of the body responsible for causing the ''trend''. HD 114174 B has a projected separation of 692 {+-} 9 mas (18.1 AU) and is 10.75 {+-} 0.12 mag (contrast of 5 Multiplication-Sign 10{sup -5}) fainter than its host in the K-band, requiring aggressive point-spread function subtraction to identify. Our astrometric time baseline of 1.4 yr demonstrates physical association through common proper motion. We find that the companion has absolute magnitude, M{sub J} = 13.97 {+-} 0.11, and colors, J - K = 0.12 {+-} 0.16 mag. These characteristics are consistent with an Almost-Equal-To T3 dwarf, initially leading us to believe that HD 114174 B was a substellar object. However, a dynamical analysis that combines radial velocity measurements with available imaging data indicates a minimum mass of 0.260 {+-} 0.010 M{sub Sun }. We conclude that HD 114174 B must be a white dwarf. Assuming a hydrogen-rich composition, atmospheric and evolutionary model fits yield an effective temperature T{sub eff} = 8200 {+-} 4000 K, surface gravity log g = 8.90 {+-} 0.02, and cooling age of t{sub c} Almost-Equal-To 3.4 Gyr, which is consistent with the 4.7{sup +2.3}{sub -2.6} Gyr host star isochronal age estimate. HD 114174 B is a benchmark object located only 26.14 {+-} 0.37 pc from the Sun. It may be studied at a level of detail comparable to Sirius and Procyon, and used to understand the link between the mass of white dwarf remnants with that of their progenitors.

Crepp, Justin R. [Department of Physics, University of Notre Dame, 225 Nieuwland Science Hall, Notre Dame, IN 46556 (United States); Johnson, John Asher [Department of Planetary Science, California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125 (United States); Howard, Andrew W. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Marcy, Geoffrey W. [Department of Astronomy, University of California, Berkeley, CA 94720 (United States); Gianninas, Alexandros; Kilic, Mukremin [Department of Physics and Astronomy, University of Oklahoma, Norman, OK 73019 (United States); Wright, Jason T., E-mail: jcrepp@nd.edu [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States)

2013-09-01T23:59:59.000Z

359

ISO-SWS calibration and the accurate modelling of cool-star atmospheres: I. Method  

E-Print Network [OSTI]

A detailed spectroscopic study of the ISO-SWS data of the red giant Alpha Tau is presented, which enables not only the accurate determination of the stellar parameters of Alpha Tau, but also serves as a critical review of the ISO-SWS calibration. This study is situated in a broader context of an iterative process in which both accurate observations of stellar templates and cool star atmosphere models are involved to improve the ISO-SWS calibration process as well as the theoretical modelling of stellar atmospheres. Therefore a sample of cool stars, covering the whole A0 -- M8 spectral classification, has been observed in order to disentangle calibration problems and problems in generating the theoretical models and corresponding synthetic spectrum. By using stellar parameters found in the literature large discrepancies were seen between the ISO-SWS data and the generated synthetic spectrum of Alpha Tau. A study of the influence of various stellar parameters on the theoretical models and synthetic spectra, in conjunction with the Kolmogorov-Smirnov test to evaluate objectively the goodness-of-fit, enables us to pin down the stellar parameters with a high accuracy: Teff = 3850 +/- 70 K, log g = 1.50 +/- 0.15, M = 2.3 +/- 0.8 Msun, z = -0.15 +/- 0.20 dex, microturbulence = 1.7 +/- 0.3 km/s, 12C/13C= 10 +/- 1, abundance of C = 8.35 +/- 0.20 dex, abundance of N= 8.35 +/- 0.25 dex, abundance of O = 8.83 +/- 0.15 dex and the angular diameter is 20.77 +/- 0.83 mas. These atmospheric parameters were then compared with the results provided by other authors using other methods and/or spectra.

L. Decin; C. Waelkens; K. Eriksson; B. Gustafsson; B. Plez; A. J. Sauval; W. Van Assche; B. Vandenbussche

2000-08-21T23:59:59.000Z

360

NEW CONSTRAINTS ON COMPANIONS AND DUST WITHIN A FEW AU OF VEGA  

SciTech Connect (OSTI)

We report on high contrast near-infrared ({approx}2.2 {mu}m) observations of Vega obtained with the Palomar Fiber Nuller, a dual sub-aperture rotating coronagraph installed at the Palomar Hale telescope. The data show consistent astrophysical null depth measurements at the {approx_equal} 10{sup -3} level or below for three different baseline orientations spanning 60 deg in azimuth, with individual 1{sigma} uncertainties {<=}7 x 10{sup -4}. These high cancellation and accuracy levels translate into a dynamic range greater than 1000:1 inside the diffraction limit of the 5 m telescope beam. Such high contrast performance is unprecedented in the near-infrared and provides improved constraints on Vega's immediate ({approx_equal}20 to 250 mas, or {approx_equal}0.15 to 2 AU) environment. In particular, our measurements rule out any potential companion in the [0.25-1 AU] region contributing more than 1% of the overall near-infrared stellar flux, with limits as low as 0.2% near 0.6 AU. These are the best upper limits established so far by direct detection for a companion to Vega in this inner region. We also conclude that any dust population contributing a significant ({>=}1%) near-infrared thermal excess can arise only within 0.2 AU of the star, and that it must consist of much smaller grains than in the solar zodiacal cloud. Dust emission from farther than {approx_equal}2 AU is also not ruled out by our observations, but would have to originate in strong scattering, pointing again to very small grains.

Mennesson, B.; Serabyn, E.; Martin, S. R.; Liewer, K.; Mawet, D. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109-8099 (United States); Hanot, C., E-mail: bertrand.mennesson@jpl.nasa.gov [AEOS, University of Liege, Allee du 6 Aout, 17 Bat B5c, 4000 Liege (Belgium)

2011-07-20T23:59:59.000Z

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361

High resolution radio observations of the colliding-wind binary WR140  

E-Print Network [OSTI]

Milli-arcsecond resolution Very Long Baseline Array (VLBA) observations of the archetype WR+O star colliding-wind binary (CWB) system WR140 are presented for 23 epochs between orbital phases 0.74 and 0.97. At 8.4 GHz, the emission in the wind-collision region (WCR) is clearly resolved as a bow-shaped arc that rotates as the orbit progresses. We interpret this rotation as due to the O star moving from SE to approximately E of the WR star, which leads to solutions for the orbit inclination of 122+/-5 deg, the longitude of the ascending node of 353+/-3 deg, and an orbit semi-major axis of 9.0+/-0.5 mas. The distance to WR140 is determined to be 1.85+/-0.16 kpc, which requires the O star to be a supergiant. The inclination implies the mass of the WR and O star to be 20+/-4 and 54+/-10 solar masses respectively. We determine a wind-momentum ratio of 0.22, with an expected half-opening angle for the WCR of 63 deg, consistent with 65+/-10 deg derived from the VLBA observations. Total flux measurements from Very Large Array (VLA) observations show the radio emission from WR140 is very closely the same from one orbit to the next, pointing strongly toward emission, absorption and cooling mechanism(s) that are controlled largely by the orbital motion. The synchrotron spectra evolve dramatically through the orbital phases observed, exhibiting both optically thin and optically thick emission. We discuss a number of absorption and cooling mechanisms that may determine the evolution of the synchrotron spectrum with orbital phase.

S. M. Dougherty; A. J. Beasley; M. J. Claussen; B. A. Zauderer; N. J. Bolingbroke

2005-01-18T23:59:59.000Z

362

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 (OSTI)

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

363

Imaging the oxygen-rich disk toward the silicate carbon star EU And  

E-Print Network [OSTI]

We present multi-epoch high-angular resolution observations of 22 GHz H2O masers toward the silicate carbon star EU And to probe the spatio-kinematic distribution of oxygen-rich material. EU And was observed at three epochs (maximum time interval of 14 months) with the Very Long Baseline Array (VLBA). Our VLBA observations of the 22 GHz H2O masers have revealed that the maser spots are distributed along a straight line across ~20 mas, with a slight hint of an S-shaped structure. The observed spectra show three prominent velocity components at V_LSR = -42, -38, and -34 km s^-1, with the masers in SW redshifted and those in NE blueshifted. The maser spots located in the middle of the overall distribution correspond to the component at V_LSR = -38 km s^-1, which approximately coincides with the systemic velocity. These observations can be interpreted as either an emerging helical jet or a disk viewed almost edge-on (a circumbinary or circum-companion disk). However, the outward motion measured in the VLBA images taken 14 months apart is much smaller than that expected from the jet scenario. Furthermore, the mid-infrared spectrum obtained with the Spitzer Space Telescope indicates that the 10 micron silicate emission is optically thin and the silicate grains are of sub-micron size. This lends support to the presence of a circum-companion disk, because an optically thin circumbinary disk consisting of such small grains would be blown away by the intense radiation pressure of the primary (carbon-rich) star. If we assume Keplerian rotation for the circum-companion disk, the mass of the companion is estimated to be 0.5--0.8 M_sun. We also identify CO2 emission features at 13--16 micron in the Spitzer spectrum of EU And--the first unambiguous detection of CO2 in silicate carbon stars.

Keiichi Ohnaka; David A. Boboltz

2007-12-14T23:59:59.000Z

364

Improved evidence for the existence of an intermediate phase during hydration of tricalcium silicate  

SciTech Connect (OSTI)

Tricalcium silicate (Ca{sub 3}SiO{sub 5}) with a very small particle size of approximately 50 nm has been prepared and hydrated for a very short time (5 min) by two different modes in a paste experiment, using a water/solid-ratio of 1.20, and by hydration as a suspension employing a water/solid-ratio of 4000. A phase containing uncondensed silicate monomers close to hydrogen atoms (either hydroxyl groups or water molecules) was formed in both experiments. This phase is distinct from anhydrous tricalcium silicate and from the calcium-silicate-hydrate (C-S-H) phase, commonly identified as the hydration product of tricalcium silicate. In the paste experiment, approximately 79% of silicon atoms were present in the hydrated phase containing silicate monomers as determined from {sup 29}Sileft brace{sup 1}Hright brace CP/MAS NMR. This result is used to show that the hydrated silicate monomers are part of a separate phase and that they cannot be attributed to a hydroxylated surface of tricalcium silicate after contact with water. The phase containing hydrated silicate monomers is metastable with respect to the C-S-H phase since it transforms into the latter in a half saturated calcium hydroxide solution. These data is used to emphasize that the hydration of tricalcium silicate proceeds in two consecutive steps. In the first reaction, an intermediate phase containing hydrated silicate monomers is formed which is subsequently transformed into C-S-H as the final hydration product in the second step. The introduction of an intermediate phase in calculations of the early hydration of tricalcium silicate can explain the presence of the induction period. It is shown that heterogeneous nucleation on appropriate crystal surfaces is able to reduce the length of the induction period and thus to accelerate the reaction of tricalcium silicate with water.

Bellmann, Frank, E-mail: frank.bellmann@uni-weimar.d [Institute for Building Materials Science, Bauhaus University Weimar, 99423 Weimar (Germany); Damidot, Denis [Ecole des Mines de Douai, Civil and Environmental Engineering Department, 941 rue Charles Bourseul, BP 10838, 59508 Doua cedexi (France); Moeser, Bernd [Institute for Building Materials Science, Bauhaus University Weimar, 99423 Weimar (Germany); Skibsted, Jorgen [Instrument Center for Solid-State NMR Spectroscopy and Interdisciplinary Nanoscience Center (iNANO), Department of Chemistry, Aarhus University DK-8000 Aarhus C (Denmark)

2010-06-15T23:59:59.000Z

365

TOWARD A SPECTROSCOPIC CENSUS OF WHITE DWARFS WITHIN 40 pc OF THE SUN  

SciTech Connect (OSTI)

We present the preliminary results of a survey aimed at significantly increasing the range and completeness of the local census of spectroscopically confirmed white dwarfs. The current census of nearby white dwarfs is reasonably complete only to about 20 pc of the Sun, a volume that includes around 130 white dwarfs, a sample too small for detailed statistical analyses. This census is largely based on follow-up investigations of stars with very large proper motions. We describe here the basis of a method that will lead to a catalog of white dwarfs within 40 pc of the Sun and north of the celestial equator, thus increasing by a factor of eight the extent of the northern sky census. White dwarf candidates are identified from the SUPERBLINK proper motion database, allowing us to investigate stars down to a proper motion limit {mu} > 40 mas yr{sup -1}, while minimizing the kinematic bias for nearby objects. The selection criteria and distance estimates are based on a combination of color-magnitude and reduced proper motion diagrams. Our follow-up spectroscopic observation campaign has so far uncovered 193 new white dwarfs, among which we identify 127 DA (including 9 DA+dM and 4 magnetic), 1 DB, 56 DC, 3 DQ, and 6 DZ stars. We perform a spectroscopic analysis on a subsample of 84 DAs, and provide their atmospheric parameters. In particular, we identify 11 new white dwarfs with spectroscopic distances within 25 pc of the Sun, including five candidates to the D < 20 pc subset.

Limoges, M.-M.; Bergeron, P. [Departement de Physique, Universite de Montreal, C.P. 6128, Succ. Centre-Ville, Montreal, Quebec H3C 3J7 (Canada); Lepine, S., E-mail: limoges@astro.umontreal.ca, E-mail: bergeron@astro.umontreal.ca, E-mail: lepine@amnh.org [Department of Astrophysics, Division of Physical Sciences, American Museum of Natural History, Central Park West at 79th Street, New York, NY 1002 (United States)

2013-05-15T23:59:59.000Z

366

WIDE COMPANIONS TO HIPPARCOS STARS WITHIN 67 pc OF THE SUN  

SciTech Connect (OSTI)

A catalog of common-proper-motion (CPM) companions to stars within 67 pc of the Sun is constructed based on the SUPERBLINK proper-motion survey. It contains 1392 CPM pairs with angular separations 30'' < {rho} < 1800'', relative proper motion between the two components less than 25 mas yr{sup -1}, and magnitudes and colors of the secondaries consistent with those of dwarfs in the (M{sub V} , V - J) diagram. In addition, we list 21 candidate white dwarf CPM companions with separations under 300'', about half of which should be physical. We estimate a 0.31 fraction of pairs with red dwarf companions to be physical systems (about 425 objects), while the rest (mostly wide pairs) are chance alignments. For each candidate companion, the probability of a physical association is evaluated. The distribution of projected separations s of the physical pairs between 2 kAU and 64 kAU follows f(s){proportional_to}s {sup -1.5}, which decreases faster than Oepik's law. We find that solar-mass dwarfs have no less than 4.4% {+-} 0.3% companions with separations larger than 2 kAU, or 3.8% {+-} 0.3% per decade of orbital separation in the 2-16 kAU range. The distribution of mass ratio of those wide companions is approximately uniform in the 0.1 < q < 1.0 range, although we observe a dip at q {approx_equal} 0.5 which, if confirmed, could be evidence of bimodal distribution of companion masses. New physical CPM companions to two exoplanet host stars are discovered.

Tokovinin, Andrei [Cerro Tololo Inter-American Observatory, Casilla 603, La Serena (Chile); Lepine, Sebastien, E-mail: atokovinin@ctio.noao.edu, E-mail: lepine@amnh.org [Department of Astrophysics, Division of Physical Sciences, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024 (United States)

2012-10-01T23:59:59.000Z

367

Proliferation Resistance Evaluation of ACR-1000 Fuel with Minor Actinides  

SciTech Connect (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

368

THE CALIFORNIA PLANET SURVEY. I. FOUR NEW GIANT EXOPLANETS  

SciTech Connect (OSTI)

We present precise Doppler measurements of four stars obtained during the past decade at Keck Observatory by the California Planet Survey (CPS). These stars, namely, HD 34445, HD 126614, HD 13931, and Gl 179, all show evidence for a single planet in Keplerian motion. We also present Doppler measurements from the Hobby-Eberly Telescope (HET) for two of the stars, HD 34445 and Gl 179, that confirm the Keck detections and significantly refine the orbital parameters. These planets add to the statistical properties of giant planets orbiting near or beyond the ice line, and merit follow-up by astrometry, imaging, and space-borne spectroscopy. Their orbital parameters span wide ranges of planetary minimum mass (M sin i = 0.38-1.9 M{sub Jup}), orbital period (P = 2.87-11.5 yr), semimajor axis (a = 2.1-5.2 AU), and eccentricity (e = 0.02-0.41). HD 34445 b (P = 2.87 yr, M sin i = 0.79 M{sub Jup}, e = 0.27) is a massive planet orbiting an old, G-type star. We announce a planet, HD 126614 Ab, and an M dwarf, HD 126614 B, orbiting the metal-rich star HD 126614 (which we now refer to as HD 126614 A). The planet, HD 126614 Ab, has minimum mass M sin i = 0.38 M{sub Jup} and orbits the stellar primary with period P = 3.41 yr and orbital separation a = 2.3 AU. The faint M dwarf companion, HD 126614 B, is separated from the stellar primary by 489 mas (33 AU) and was discovered with direct observations using adaptive optics and the PHARO camera at Palomar Observatory. The stellar primary in this new system, HD 126614 A, has the highest measured metallicity ([Fe/H] = +0.56) of any known planet-bearing star. HD 13931 b (P = 11.5 yr, M sin i = 1.88 M{sub Jup}, e = 0.02) is a Jupiter analog orbiting a near solar twin. Gl 179 b (P = 6.3 yr, M sin i = 0.82 M{sub Jup}, e = 0.21) is a massive planet orbiting a faint M dwarf. The high metallicity of Gl 179 is consistent with the planet-metallicity correlation among M dwarfs, as documented recently by Johnson and Apps.

Howard, Andrew W.; Marcy, Geoffrey W.; Peek, Kathryn M. G. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Johnson, John Asher [Department of Astrophysics, California Institute of Technology, MC 249-17, Pasadena, CA 91125 (United States); Fischer, Debra A.; Isaacson, Howard [Department of Astronomy, Yale University, New Haven, CT 06511 (United States); Wright, Jason T.; Bernat, David [Pennsylvania State University, University Park, PA 16802 (United States); Henry, Gregory W. [Center of Excellence in Information Systems, Tennessee State University, 3500 John A. Merritt Blvd., Box 9501, Nashville, TN 37209 (United States); Apps, Kevin [75B Cheyne Walk, Horley, Surrey RH6 7LR (United Kingdom); Endl, Michael; Cochran, William D. [McDonald Observatory, University of Texas at Austin, Austin, TX 78712 (United States); Valenti, Jeff A.; Anderson, Jay [Space Telescope Science Institute, 3700 San Martin Dr., Baltimore, MD 21218 (United States); Piskunov, Nikolai E., E-mail: howard@astro.berkeley.ed [Department of Astronomy and Space Physics, Uppsala University, Box 515, 751 20 Uppsala (Sweden)

2010-10-01T23:59:59.000Z

369

Quantitative comparison of noise texture across CT scanners from different manufacturers  

SciTech Connect (OSTI)

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

370

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 (OSTI)

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

371

Cs{sub 4}P{sub 2}Se{sub 10}: A new compound discovered with the application of solid-state and high temperature NMR  

SciTech Connect (OSTI)

The new compound Cs{sub 4}P{sub 2}Se{sub 10} was serendipitously produced in high purity during a high-temperature synthesis done in a nuclear magnetic resonance (NMR) spectrometer. {sup 31}P magic angle spinning (MAS) NMR of the products of the synthesis revealed that the dominant phosphorus-containing product had a chemical shift of -52.8 ppm that could not be assigned to any known compound. Deep reddish brown well-formed plate-like crystals were isolated from the NMR reaction ampoule and the structure was solved with X-ray diffraction. Cs{sub 4}P{sub 2}Se{sub 10} has the triclinic space group P-1 with a=7.3587(11) A, b=7.4546(11) A, c=10.1420(15) A, {alpha}=85.938(2){sup o}, {beta}=88.055(2){sup o}, and {gamma}=85.609(2){sup o} and contains the [P{sub 2}Se{sub 10}]{sup 4-} anion. To our knowledge, this is the first compound containing this anion that is composed of two tetrahedral (PSe{sub 4}) units connected by a diselenide linkage. It was also possible to form a glass by quenching the melt in ice water, and Cs{sub 4}P{sub 2}Se{sub 10} was recovered upon annealing. The static {sup 31}P NMR spectrum at 350 deg. C contained a single peak with a -35 ppm chemical shift and a {approx}7 ppm peak width. This study highlights the potential of solid-state and high-temperature NMR for aiding discovery of new compounds and for probing the species that exist at high temperature. - Graphical abstract: The new compound Cs{sub 4}P{sub 2}Se{sub 10} was discovered following a high-temperature in situ synthesis in the NMR spectrometer and the structure was determined by single-crystal X-ray diffraction. It contains the new [P{sub 2}Se{sub 10}]{sup 4-} anion.

Gave, Matthew A.; Canlas, Christian G. [Department of Chemistry, Michigan State University, East Lansing, MI 48824 (United States); Chung, In [Department of Chemistry, Michigan State University, East Lansing, MI 48824 (United States); Department of Chemistry, Northwestern University, Evanston, IL 60208 (United States); Iyer, Ratnasabapathy G. [Department of Chemistry, Michigan State University, East Lansing, MI 48824 (United States); Kanatzidis, Mercouri G. [Department of Chemistry, Michigan State University, East Lansing, MI 48824 (United States); Department of Chemistry, Northwestern University, Evanston, IL 60208 (United States)], E-mail: m-kanatzidis@northwestern.edu; Weliky, David P. [Department of Chemistry, Michigan State University, East Lansing, MI 48824 (United States)], E-mail: weliky@chemistry.msu.edu

2007-10-15T23:59:59.000Z

372

Implications of CT noise and artifacts for quantitative {sup 99m}Tc SPECT/CT imaging  

SciTech Connect (OSTI)

Purpose: This paper evaluates the effects of computed tomography (CT) image noise and artifacts on quantitative single-photon emission computed-tomography (SPECT) imaging, with the aim of establishing an appropriate range of CT acquisition parameters for low-dose protocols with respect to accurate SPECT attenuation correction (AC). Methods: SPECT images of two geometric and one anthropomorphic phantom were reconstructed iteratively using CT scans acquired at a range of dose levels (CTDI{sub vol} = 0.4 to 46 mGy). Resultant SPECT image quality was evaluated by comparing mean signal, background noise, and artifacts to SPECT images reconstructed using the highest dose CT for AC. Noise injection was performed on linear-attenuation (?) maps to determine the CT noise threshold for accurate AC. Results: High levels of CT noise (? ? 200400 HU) resulted in low ?-maps noise (? ? 1%3%). Noise levels greater than ?10% in 140 keV ?-maps were required to produce visibly perceptible increases of ?15% in {sup 99m}Tc SPECT images. These noise levels would be achieved at low CT dose levels (CTDI{sub vol} = 4 ?Gy) that are over 2 orders of magnitude lower than the minimum dose for diagnostic CT scanners. CT noise could also lower (bias) the expected ? values. The relative error in reconstructed SPECT signal trended linearly with the relative shift in ?. SPECT signal was, on average, underestimated in regions corresponding with beam-hardening artifacts in CT images. Any process that has the potential to change the CT number of a region by ?100 HU (e.g., misregistration between CT images and SPECT images due to motion, the presence of contrast in CT images) could introduce errors in ?{sub 140} {sub keV} on the order of 10%, that in turn, could introduce errors on the order of ?10% into the reconstructed {sup 99m}Tc SPECT image. Conclusions: The impact of CT noise on SPECT noise was demonstrated to be negligible for clinically achievable CT parameters. Because CT dose levels that affect SPECT quantification is low (CTDI{sub vol} ? 4 ?Gy), the low dose limit for the CT exam as part of SPECT/CT will be guided by CT image quality requirements for anatomical localization and artifact reduction. A CT technique with higher kVp in combination with lower mAs is recommended when low-dose CT images are used for AC to minimize beam-hardening artifacts.

Hulme, K. W.; Kappadath, S. C., E-mail: skappadath@mdanderson.org [Department of Imaging Physics, The University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030 and The University of Texas Graduate School of Biomedical Sciences, Houston, Texas 77030 (United States)

2014-04-15T23:59:59.000Z

373

AN ALL-SKY CATALOG OF BRIGHT M DWARFS  

SciTech Connect (OSTI)

We present an all-sky catalog of M dwarf stars with apparent infrared magnitude J < 10. The 8889 stars are selected from the ongoing SUPERBLINK survey of stars with proper motion {mu} > 40 mas yr{sup -1}, supplemented on the bright end with the Tycho-2 catalog. Completeness tests which account for kinematic (proper motion) bias suggest that our catalog represents {approx}75% of the estimated {approx}11, 900 M dwarfs with J < 10 expected to populate the entire sky. Our catalog is, however, significantly more complete for the northern sky ({approx}90%) than it is for the south ({approx}60%). Stars are identified as cool, red M dwarfs from a combination of optical and infrared color cuts, and are distinguished from background M giants and highly reddened stars using either existing parallax measurements or, if such measurements are lacking, using their location in an optical-to-infrared reduced proper motion diagram. These bright M dwarfs are all prime targets for exoplanet surveys using the Doppler radial velocity or transit methods; the combination of low-mass and bright apparent magnitude should make possible the detection of Earth-size planets on short-period orbits using currently available techniques. Parallax measurements, when available, and photometric distance estimates are provided for all stars, and these place most systems within 60 pc of the Sun. Spectral type estimated from V - J color shows that most of the stars range from K7 to M4, with only a few late M dwarfs, all within 20 pc. Proximity to the Sun also makes these stars good targets for high-resolution exoplanet imaging searches, especially if younger objects can be identified on the basis of X-ray or UV excess. For that purpose, we include X-ray flux from ROSAT and FUV/NUV ultraviolet magnitudes from GALEX for all stars for which a counterpart can be identified in those catalogs. Additional photometric data include optical magnitudes from Digitized Sky Survey plates and infrared magnitudes from the Two Micron All Sky Survey.

Lepine, Sebastien [Department of Astrophysics, Division of Physical Sciences, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024 (United States); Gaidos, Eric [Department of Geology and Geophysics, University of Hawaii, 1680 East-West Road, Honolulu, HI 96822 (United States)

2011-10-15T23:59:59.000Z

374

Enhancing BWR Proliferation Resistance Fuel with Minor Actinides  

SciTech Connect (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

375

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

SciTech Connect (OSTI)

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

376

Structural analysis and characterization of layer perovskite oxynitrides made from Dion-Jacobson oxide precursors  

SciTech Connect (OSTI)

A three-layer oxynitride Ruddlesden-Popper phase Rb{sub 1+x}Ca{sub 2}Nb{sub 3}O{sub 10-x}N{sub x}.yH{sub 2}O (x=0.7-0.8, y=0.4-0.6) was synthesized by ammonialysis at 800{sup o}C from the Dion-Jacobson phase RbCa{sub 2}Nb{sub 3}O{sub 10} in the presence of Rb{sub 2}CO{sub 3}. Incorporation of nitrogen into the layer perovskite structure was confirmed by XPS, combustion analysis, and MAS NMR. The water content was determined by thermal gravimetric analysis and the rubidium content by ICP-MS. A similar layered perovskite interconversion occurred in the two-layer Dion-Jacobson oxide RbLaNb{sub 2}O{sub 7} to yield Rb{sub 1+x}LaNb{sub 2}O{sub 7-x}N{sub x}.yH{sub 2}O (x=0.7-0.8, y=0.5-1.0). Both compounds were air- and moisture-sensitive, with rapid loss of nitrogen by oxidation and hydrolysis reactions. The structure of the three-layer oxynitride Rb{sub 1.7}Ca{sub 2}Nb{sub 3}O{sub 9.3}N{sub 0.7}.0.5H{sub 2}O was solved in space group P4/mmm with a=3.887(3) and c=18.65(1)A, by Rietveld refinement of X-ray powder diffraction data. The two-layer oxynitride structure Rb{sub 1.8}LaNb{sub 2}O{sub 6.3}N{sub 0.7}.1.0H{sub 2}O was also determined in space group P4/mmm with a=3.934(2) and c=14.697(2)A. GSAS refinement of synchrotron X-ray powder diffraction data showed that the water molecules were intercalated between a double layer of Rb+ ions in both the two- and three-layer Ruddlesden-Popper structures. Optical band gaps were measured by diffuse reflectance UV-vis for both materials. An indirect band gap of 2.51eV and a direct band gap of 2.99eV were found for the three-layer compound, while an indirect band gap of 2.29eV and a direct band gap of 2.84eV were measured for the two-layer compound. Photocatalytic activity tests of the three-layer compound under 380nm pass filtered light with AgNO{sub 3} as a sacrificial electron acceptor gave a quantum yield of 0.025% for oxygen evolution.

Schottenfeld, Joshua A. [Department of Chemistry, Pennsylvania State University, University Park, PA 16802 (United States); Benesi, Alan J. [Department of Chemistry, Pennsylvania State University, University Park, PA 16802 (United States); Stephens, Peter W. [Department of Physics and Astronomy, State University of New York, Stony Brook, New York 11794 (United States); Chen, Gugang [Departments of Physics, Pennsylvania State University, University Park, PA 16802 (United States); Eklund, Peter C. [Departments of Physics, Pennsylvania State University, University Park, PA 16802 (United States); Mallouk, Thomas E. [Department of Chemistry, Pennsylvania State University, University Park, PA 16802 (United States)]. E-mail: tom@chem.psu.edu

2005-07-15T23:59:59.000Z

377

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

SciTech Connect (OSTI)

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

378

NbF{sub 5} and TaF{sub 5}: Assignment of {sup 19}F NMR resonances and chemical bond analysis from GIPAW calculations  

SciTech Connect (OSTI)

The {sup 19}F isotropic chemical shifts (?{sub iso}) of two isomorphic compounds, NbF{sub 5} and TaF{sub 5}, which involve six nonequivalent fluorine sites, have been experimentally determined from the reconstruction of 1D {sup 19}F MAS NMR spectra. In parallel, the corresponding {sup 19}F chemical shielding tensors have been calculated using the GIPAW method for both experimental and DFT-optimized structures. Furthermore, the [M{sub 4}F{sub 20}] units of NbF{sub 5} and TaF{sub 5} being held together by van der Waals interactions, the relevance of Grimme corrections to the DFT optimization processes has been evaluated. However, the semi-empirical dispersion correction term introduced by such a method does not show any significant improvement. Nonetheless, a complete and convincing assignment of the {sup 19}F NMR lines of NbF{sub 5} and TaF{sub 5} is obtained, ensured by the linearity between experimental {sup 19}F ?{sub iso} values and calculated {sup 19}F isotropic chemical shielding ?{sub iso} values. The effects of the geometry optimizations have been carefully analyzed, confirming among other matters, the inaccuracy of the experimental structure of NbF{sub 5}. The relationships between the fluorine chemical shifts, the nature of the fluorine atoms (bridging or terminal), the position of the terminal ones (opposite or perpendicular to the bridging ones), the fluorine charges, the ionicity and the length of the MF bonds have been established. Additionally, for three of the {sup 19}F NMR lines of NbF{sub 5}, distorted multiplets, arising from {sup 1}J-coupling and residual dipolar coupling between the {sup 19}F and {sup 93}Nb nuclei, were simulated yielding to values of {sup 93}Nb{sup 19}F {sup 1}J-coupling for the corresponding fluorine sites. - Graphical abstract: The complete assignment of the {sup 19}F NMR lines of NbF{sub 5} and TaF{sub 5} allow establishing relationships between the {sup 19}F ?{sub iso} values, the nature of the fluorine atoms (bridging or terminal), the position of the terminal ones (opposite or perpendicular to the bridging ones), the fluorine charges, the ionicity and the length of the MF bonds. Display Omitted - Highlights: The {sup 19}F ?{sub iso} values of NbF{sub 5} and TaF{sub 5} have been determined. The {sup 19}F chemical shielding tensors have been calculated using the GIPAW method. A confident assignment of the {sup 19}F NMR lines of NbF{sub 5} and TaF{sub 5} is obtained. The relationships between the {sup 19}F?{sub iso} values and the MF bonds features are established.

Biswal, Mamata, E-mail: Mamata.Biswal-Susanta_Kumar_Nayak.Etu@univ-lemans.fr [LUNAM Universit, Universit du Maine, CNRS UMR 6283, Institut des Molcules et des Matriaux du Mans, Avenue Olivier Messiaen, 72085 Le Mans Cedex 9 (France); Body, Monique, E-mail: monique.body@univ-lemans.fr [LUNAM Universit, Universit du Maine, CNRS UMR 6283, Institut des Molcules et des Matriaux du Mans, Avenue Olivier Messiaen, 72085 Le Mans Cedex 9 (France); Legein, Christophe, E-mail: christophe.legein@univ-lemans.fr [LUNAM Universit, Universit du Maine, CNRS UMR 6283, Institut des Molcules et des Matriaux du Mans, Avenue Olivier Messiaen, 72085 Le Mans Cedex 9 (France); Sadoc, Aymeric, E-mail: Aymeric.Sadoc@cnrs-imn.fr [Institut des Matriaux Jean Rouxel (IMN), Universit de Nantes, CNRS, 2 rue de la Houssinire, BP 32229, 44322 Nantes Cedex 3 (France); Boucher, Florent, E-mail: Florent.Boucher@cnrs-imn.fr [Institut des Matriaux Jean Rouxel (IMN), Universit de Nantes, CNRS, 2 rue de la Houssinire, BP 32229, 44322 Nantes Cedex 3 (France)

2013-11-15T23:59:59.000Z

379

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 (OSTI)

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

380

A SPECTROSCOPIC CATALOG OF THE BRIGHTEST (J < 9) M DWARFS IN THE NORTHERN SKY{sup ,}  

SciTech Connect (OSTI)

We present a spectroscopic catalog of the 1564 brightest (J < 9) M dwarf candidates in the northern sky, as selected from the SUPERBLINK proper motion catalog. Observations confirm 1408 of the candidates to be late-K and M dwarfs with spectral subtypes K7-M6. From the low ({mu} > 40 mas yr{sup -1}) proper motion limit and high level of completeness of the SUPERBLINK catalog in that magnitude range, we estimate that our spectroscopic census most likely includes >90% of all existing, northern-sky M dwarfs with apparent magnitude J < 9. Only 682 stars in our sample are listed in the Third Catalog of Nearby Stars (CNS3); most others are relative unknowns and have spectroscopic data presented here for the first time. Spectral subtypes are assigned based on spectral index measurements of CaH and TiO molecular bands; a comparison of spectra from the same stars obtained at different observatories, however, reveals that spectral band index measurements are dependent on spectral resolution, spectrophotometric calibration, and other instrumental factors. As a result, we find that a consistent classification scheme requires that spectral indices be calibrated and corrected for each observatory/instrument used. After systematic corrections and a recalibration of the subtype-index relationships for the CaH2, CaH3, TiO5, and TiO6 spectral indices, we find that we can consistently and reliably classify all our stars to a half-subtype precision. The use of corrected spectral indices further requires us to recalibrate the {zeta} parameter, a metallicity indicator based on the ratio of TiO and CaH optical bandheads. However, we find that our {zeta} values are not sensitive enough to diagnose metallicity variations in dwarfs of subtypes M2 and earlier ({+-}0.5 dex accuracy) and are only marginally useful at later M3-M5 subtypes ({+-}0.2 dex accuracy). Fits of our spectra to the Phoenix atmospheric model grid are used to estimate effective temperatures. These suggest the existence of a plateau in the M1-M3 subtype range, in agreement with model fits of infrared spectra but at odds with photometric determinations of T{sub eff}. Existing geometric parallax measurements are extracted from the literature for 624 stars, and are used to determine spectroscopic and photometric distances for all the other stars. Active dwarfs are identified from measurements of H{alpha} equivalent widths, and we find a strong correlation between H{alpha} emission in M dwarfs and detected X-ray emission from ROSAT and/or a large UV excess in the GALEX point source catalog. We combine proper motion data and photometric distances to evaluate the (U, V, W) distribution in velocity space, which is found to correlate tightly with the velocity distribution of G dwarfs in the solar neighborhood. However, active stars show a smaller dispersion in their space velocities, which is consistent with those stars being younger on average. Our catalog will be most useful to guide the selection of the best M dwarf targets for exoplanet searches, in particular those using high-precision radial velocity measurements.

Lepine, Sebastien; Wilde, Matthew; Rojas-Ayala, Barbara; Cruz, Kelle L. [Department of Astrophysics, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024 (United States); Hilton, Eric J.; Mann, Andrew W. [Institute for Astrophysics, University of Hawaii, Honolulu, HI 96822 (United States); Gaidos, Eric, E-mail: lepine@amnh.org, E-mail: brojas-ayala@amnh.org, E-mail: mwilde@amnh.org, E-mail: mshara@amnh.org, E-mail: hilton@ifa.hawaii.edu, E-mail: amann@ifa.hawaii.edu, E-mail: gaidos@hawaii.edu, E-mail: kellecruz@gmail.com [Department of Geology and Geophysics, University of Hawaii, 1680 East-West Road, Honolulu, HI 96822 (United States)

2013-04-15T23:59:59.000Z