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E-Print Network [OSTI]

INVERTIBILITY IN INFINITE-DIMENSIONAL SPACES CHIA-CHUAN TSENG AND NGAI-CHING WONG Abstract. An interesting result of Doyle and Hocking states that a topological n-manifold is invertible if and only is invertible. We shall also discuss the invertibility of other infinite-dimensional objects as well

Wong, Ngai-Ching


Short-Term Generation Asset Valuation Chung-Li Tseng, Graydon Barz  

E-Print Network [OSTI]

Short-Term Generation Asset Valuation Chung-Li Tseng, Graydon Barz Department of Civil Engineering 94305, USA chungli@eng.umd.edu, gbarz@leland.stanford.edu Abstract In this paper we present a method for valuing a power plant over a short-term period using Monte Carlo sim- ulation. The power plant valuation


sSCADA: Securing SCADA Infrastructure Communications Yongge Wang and Bei-Tseng Chu  

E-Print Network [OSTI]

sSCADA: Securing SCADA Infrastructure Communications Yongge Wang and Bei-Tseng Chu Dept. of SIS, UNC Charlotte, 9201 University City Blvd, Charlotte, NC 28223, August 5, 2004 Abstract Distributed, and wastewater industries. While control systems can be vulnerable to a variety of types of cyber attacks


Understanding the Impact of Power Loss on Flash Memory Hung-Wei Tseng Laura M. Grupp Steven Swanson  

E-Print Network [OSTI]

Understanding the Impact of Power Loss on Flash Memory Hung-Wei Tseng Laura M. Grupp Steven Swanson,Measurement,Performance,Reliability Keywords flash memory, power failure, power loss 1. INTRODUCTION As flash-based solid-state drives (SSDs is what happens to the data on an SSD when power failure occurs unexpectedly. Power loss in flash

Wang, Deli


Ultrafast all-optical switching via coherent modulation of metamaterial absorption Xu Fang, Ming Lun Tseng, Jun-Yu Ou, Kevin F. MacDonald, Din Ping Tsai, and Nikolay I. Zheludev  

E-Print Network [OSTI]

Lun Tseng, Jun-Yu Ou, Kevin F. MacDonald, Din Ping Tsai, and Nikolay I. Zheludev Citation: Applied absorption Xu Fang,1,a) Ming Lun Tseng,2,3 Jun-Yu Ou,1 Kevin F. MacDonald,1 Din Ping Tsai,2,3,4 and Nikolay I

Zheludev, Nikolay


Women @ Energy: Shawna Waugh | Department of Energy  

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

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 Center Home Page on Delicious Rank EERE:YearRound-Up from theDepartment of Dept.| WEATHERIZATION5IskiMaylingNatalieRobinSandraChinn


The Outhouse Shawna Mahoney, John Burke and Brian Wyvill  

E-Print Network [OSTI]

-up. An environmentalist, she wears flannel shirt, fleece, jeans, hemp hat, hip waders or rubber boots and pack. She

Wyvill, Brian


An inertial Tseng's type proximal algorithm for nonsmooth and ...  

E-Print Network [OSTI]

Jun 3, 2014 ... Page 1 ... papers written in the last fifteen years on this topic, see [1–3,7,13,15,17,



High Performance Elastomeric Nanocomposites via Solvent Exchange Processing Shawna M. Liff, Nitin Kumar, Gareth H. McKinley*  

E-Print Network [OSTI]

is expected only when the nanoparticles are fully exfoliated in #12;3 the polymer matrix. This is difficult. In the present work we outline a novel solvent exchange approach to efficiently exfoliate nanoparticles


last saved on 3/12/2013 CURRENT DEGREE PROGRAMS  

E-Print Network [OSTI]

1105 B Statistics SMG 22 1702 B Sustainable Energy SMG 22 0121 B Theatre Arts SMG 22 5534 B Visual Arts SMG 22 0525 C Marketing SMG 22 5004 C Operations and Technology Management SMG 22 0531 C

Guenther, Frank


Distributed Intrusion Detection Models for Mobile Ad Hoc Networks CHIN-YANG HENRY TSENG  

E-Print Network [OSTI]

feel really lucky to be his student at UC Davis. I sincerely thank to Professor Matt Bishop in the OFFICE OF GRADUATE STUDIES of the UNIVERSITY OF CALIFORNIA DAVIS Approved By: Karl N. Levitt, Chair. I am very grateful that he spent his precious time and energy for advising my works

California at Davis, University of


SPECIAL ISSUE: Quantitative Models for Energy Systems SPECIAL EDITORS: Chung-Li Tseng  

E-Print Network [OSTI]

to mitigate transmission congestion, which can subsequently change locational marginal prices of the network la Torre and Antonio J. Conejo 52 Impact of Phase Shifters on Locational Prices Bo Lu, Zuyi Li Shifters on Locational Prices" by Bo Lu, Zuyi Li, and Mohammand Shahidehpour, proposes using phase shifters

Tseng, Chung-Li


A Transmission-Constrained Unit Commitment Method Chung-Li Tseng, Shmuel S. Oren,  

E-Print Network [OSTI]

. A test problem involving more than 2500 transmission lines and 2200 buses is tested along with other test located in multiple areas that are interconnected via transmission lines. If the transmission constraints are not considered, the sched- ule obtained might cause some transmission lines to be overloaded. In this paper, we


Flexible Facility Interior Layout: A Real Options and Chung-Li Tseng  

E-Print Network [OSTI]

, Delta Consulting Group, Inc., 310 Commerce Street, Occoquan, VA 22125, USA. Tel: (703) 497-7735, fax, University of Missouri-Rolla, Rolla, MO 65409, USA. Tel: (573) 341-7621, fax: (573) 341-6567, email: chungli will be evaluated. The concept of real options, stemming from financial options, refers to flexibility em- bedded

Tseng, Chung-Li


Supramolecular Nanoparticles for Molecular Diagnostics and Therapeutics  

E-Print Network [OSTI]

I. Kornblum, W. H. Yong, T. G. Graeber, H. -R. Tseng, CancerKornblum, W. H. Yong, T. G. Graeber, H. R. Tseng, Cancer Res

Chen, Kuan-Ju



allotriploid hybryd females: Topics by E-print Network  

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

an in-depth survey and focus group interviews (more) Held, Shawna Sue 2013-01-01 10 Perception of Conspecific Female Pheromone Stimulates Female Calling in an Arctiid Moth,...


An Evaluation of Pseudo Random Testing for Detecting Real Defects Chao-Wen Tseng, Subhasish Mitra, Scott Davidson*, and Edward J. McCluskey  

E-Print Network [OSTI]

, the reader is referred to the lecture series in the proceedings of the International Test Conference, 2000 Microsystems Menlo Park, California Abstract Research has shown that single stuck-at fault (SSF) N- detect test-speed to reduce the test time. In addition, timing-related defects and unmodeled defects are more likely

McCluskey, Edward J.


E-Print Network 3.0 - ancestors chinese bombyx Sample Search...  

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

Semantic classification of Chinese unknown words Huihsin Tseng Linguistics University of Colorado... categories to unknown Chinese words (words not already in the CiLin thesaurus...


Central Arizona -Phoenix Long-Term Ecological  

E-Print Network [OSTI]

, Goldsmith, Marussich, Roach, & Wu Jenerette & Wu Katti, Shochat, Stuart, Lemmer, & Rambo Lewis, Wu, & Grimm, Sicotte, & Yang Roach & Grimm Quay Stuart Shochat, Faeth, Fagan, Tseng, Rambo, & Cassalata Swanson Shochat

Hall, Sharon J.


Minutes for the March 11, 2008 Provost Employee Communication Council Meeting  

E-Print Network [OSTI]

in attendance: Dawn Brennan, Susan Chisholm, Bill Corey, Shawna Edinger, Carol Garges, Iva Gillet, Katherine) in sports and teenagers. He is still practicing. He became the Dean of the School of Medicine in 2002--putting a team together and working with that team and coming back to write about it. Update on current dean

Whittle, Mark

Note: This page contains sample records for the topic "tseng smg shawna" 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.


autocompensating quantum cryptography: Topics by E-print Network  

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

Summary: Towards Non-Black-Box Lower Bounds in Cryptography Rafael Pass , Wei-Lung Dustin Tseng on the impossibility of basing cryptography on NP hardness (these works also...


Modeling and Computing Two-settlement Oligopolistic Equilibrium in a Congested Electricity Network  

E-Print Network [OSTI]

60. [5] Chen, X. and M. Fukushima. 2004. A smoothing methodPress, Cambridge, MA. [11] Fukushima, M. , Z. -Q. Luo andApplications. 10 1 5-34. [12] Fukushima, M. and P. Tseng.

Yao, Jian; Adler, Ilan; Oren, Shmuel S



The bias of the submillimetre galaxy population: SMGs are poor tracers of the most massive structures in the z ~ 2 Universe  

E-Print Network [OSTI]

It is often claimed that overdensities of (or even individual bright) submillimetre-selected galaxies (SMGs) trace the assembly of the most-massive dark matter structures in the Universe. We test this claim by performing a counts-in-cells analysis of mock SMG catalogues derived from the Bolshoi cosmological simulation to investigate how well SMG associations trace the underlying dark matter structure. We find that SMGs exhibit a relatively complex bias: some regions of high SMG overdensity are underdense in terms of dark matter mass, and some regions of high dark matter overdensity contain no SMGs. Because of their rarity, Poisson noise causes scatter in the SMG overdensity at fixed dark matter overdensity. Consequently, rich associations of less-luminous, more-abundant galaxies (i.e. Lyman-break galaxy analogues) trace the highest dark matter overdensities much better than SMGs. Even on average, SMG associations are relatively poor tracers of the most significant dark matter overdensities because of `downsiz...

Miller, Tim B; Chapman, Scott C; Behroozi, Peter S



Metrics for sampling-based motion planning  

E-Print Network [OSTI]

that supports our research, for the many discussions, and for the rewarding collaborations, especially: Burchan Bayazit, Jyh-Ming Lien, Olga Pearce, Roger Pearce, Samuel Rodr guez, Guang Song, Xinyu Tang, Lydia Tapia, Shawna Thomas, Aim ee Vargas, and Dawen Xie... Government and its Consejo Nacional de Ciencia y Tec- nolog a , and to the U.S. Government, its Department of State, and the Institute of International Education. Thanks to Marcos and Esperanza, my parents. They showed me how to search for my way in life...

Morales Aguirre, Marco Antonio



Design and manipulation of 1-D rugate photonic crystals of porous silicon for chemical sensing applications  

E-Print Network [OSTI]

Formulating with Dow Epoxy Resin. Dow Chemical Company, formNo. 125-9326. Dow Liquid Epoxy Resins. Dow Chemical Company,1098 SMG, 1998. Epoxy Additives and Resins. Air Products and

King, Brian Henry



Terr. Atmos. Ocean. Sci., Vol. 17, No. 4, 703-722, December 2006 Distribution of Gassy Sediments and Mud Volcanoes Offshore  

E-Print Network [OSTI]

Sediments and Mud Volcanoes Offshore Southwestern Taiwan Jui-Kun Chiu 1 , Wei-Hao Tseng 1 , and Char@ntu.edu.tw This study presents the results from recent intense marine geophysical surveys conducted offshore: offshore Kaohsiung, adjacent to the Kaoping Submarine Canyon, near the head of the Fangliao Submarine

Lin, Andrew Tien-Shun


The Energy Journal, Vol. 32, No. 3. Copyright 2011 by the IAEE. All rights reserved. * Corresponding author. School of Social Sciences, Humanities and Arts, and School of Engi-  

E-Print Network [OSTI]

the optimal investment timing when a coal-fired plant owner considers introducing clean technologies in face.tseng@unsw.edu.au Inducing Clean Technology in the Electricity Sector: Tradable Permits or Carbon Tax Policies? Yihsu Chen instru- ments offer firms different incentives for adopting clean technologies. This paper explores

Tseng, Chung-Li


IEEE TRANSACTIONS ON MOBILE COMPUTING, TMC-0278-1006.R1 1 Efficient Placement and Dispatch of Sensors  

E-Print Network [OSTI]

of Sensors in a Wireless Sensor Network You-Chiun Wang, Chun-Chi Hu, and Yu-Chee Tseng, Senior Member, IEEE Abstract-- Sensor deployment is a critical issue because it affects the cost and detection capability of a wireless sensor network. In this work, we consider two related deployment problems: sensor placement

Tseng, Yu-Chee


Polymer solar cell by blade coating Yu-Han Chang a  

E-Print Network [OSTI]

Polymer solar cell by blade coating Yu-Han Chang a , Shin-Rong Tseng a , Chun-Yu Chen a , Hsin Tung University, Hsinchu 300, Taiwan, Republic of China b Department of Electrical Engineering, National Tsing Hua University, Hsinchu 300, Taiwan, Republic of China c Department of Applied Chemistry


COMMUNICATION Are Residues in a Protein Folding Nucleus  

E-Print Network [OSTI]

COMMUNICATION Are Residues in a Protein Folding Nucleus Evolutionarily Conserved? Yan Yuan Tseng is the hallmark of life. It is important to understand how protein folding and evolution influence each other in protein folding nucleus as measured by experi- mental f-value and selection pressure as measured by v

Dai, Yang


Proposal for New Module Module Title: Photonic Materials  

E-Print Network [OSTI]

Information Academic Unit responsible for the module ORC Core/Compulsory/Optional Compulsory Programme, Dr. S. M. Ganapathy, Dr. G. Brambilla Contact (email ID) acp@orc.soton.ac.uk; smg@orc.soton.ac.uk; gb2@orc.soton.ac.uk Will the module be subject to external accreditation? No If yes, by which body

Southampton, University of



SciTech Connect (OSTI)

We present an Atacama Large Millimeter/submillimeter Array (ALMA) Cycle 0 survey of 126 submillimeter sources from the LABOCA ECDFS Submillimeter Survey (LESS). Our 870 {mu}m survey with ALMA (ALESS) has produced maps {approx}3 Multiplication-Sign deeper and with a beam area {approx}200 Multiplication-Sign smaller than the original LESS observations, doubling the current number of interferometrically-observed submillimeter sources. The high resolution of these maps allows us to resolve sources that were previously blended and accurately identify the origin of the submillimeter emission. We discuss the creation of the ALESS submillimeter galaxy (SMG) catalog, including the main sample of 99 SMGs and a supplementary sample of 32 SMGs. We find that at least 35% (possibly up to 50%) of the detected LABOCA sources have been resolved into multiple SMGs, and that the average number of SMGs per LESS source increases with LESS flux density. Using the (now precisely known) SMG positions, we empirically test the theoretical expectation for the uncertainty in the single-dish source positions. We also compare our catalog to the previously predicted radio/mid-infrared counterparts, finding that 45% of the ALESS SMGs were missed by this method. Our {approx}1.''6 resolution allows us to measure a size of {approx}9 kpc Multiplication-Sign 5 kpc for the rest-frame {approx}300 {mu}m emission region in one resolved SMG, implying a star formation rate surface density of 80 M{sub Sun} yr{sup -1} kpc{sup -2}, and we constrain the emission regions in the remaining SMGs to be <10 kpc. As the first statistically reliable survey of SMGs, this will provide the basis for an unbiased multiwavelength study of SMG properties.

Hodge, J. A.; Walter, F.; Decarli, R. [Max-Planck Institute for Astronomy, Koenigstuhl 17, D-69117 Heidelberg (Germany); Karim, A.; Smail, I.; Swinbank, A. M.; Alexander, D. M.; Danielson, A. L. R.; Edge, A. C. [Institute for Computational Cosmology, Durham University, South Road, Durham, DH1 3LE (United Kingdom); Biggs, A. D.; De Breuck, C. [European Southern Observatory, Karl-Schwarzschild Strasse 2, D-85748 Garching (Germany); Ivison, R. J. [UK Astronomy Technology Center, Science and Technology Facilities Council, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Weiss, A. [Max-Planck Institut fuer Radioastronomie, Auf dem Huegel 69, D-53121 Bonn (Germany); Bertoldi, F. [Argelander-Institute of Astronomy, Bonn University, Auf dem Huegel 71, D-53121 Bonn (Germany); Brandt, W. N. [Department of Astronomy and Astrophysics, 525 Davey Lab, Pennsylvania State University, University Park, PA 16802 (United States); Chapman, S. C. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Coppin, K. E. K. [Department of Physics, McGill University, 3600 Rue University, Montreal, QC H3A 2T8 (Canada); Cox, P. [IRAM, 300 rue de la piscine, F-38406 Saint-Martin d'Heres (France); Dannerbauer, H. [Universitaet Wien, Institut fuer Astrophysik, Tuerkenschanzstrasse 17, A-1180 Wien (Austria); Greve, T. R., E-mail: hodge@mpia.de [University College London, Department of Physics and Astronomy, Gower Street, London, WC1E 6BT (United Kingdom); and others



The L1 acquisition of clitic placement in Cypriot Greek  

E-Print Network [OSTI]

)…………………………………………………………………....110 Table 4.4: Clitic production in early SMG: the Christofidou Corpus (Marinis 2000) and the Doukas Corpus (Tsakali 2006)………………………………….111 Tables 4.5: Clitic placement in child Serbo/Croatian (Naturalistic data) (Ilic & Ud Deen 2004... )……………………………………………………………………...114 Tables 4.6: Clitic placement in child Serbo/Croatian (Experimental data) (Ilic & Ud Deen 2004)………………………………………………………………….114 Table 4.7: Proportion of full objects, demonstrative pronouns, strong personal pronouns and clitics in Dutch clitic scenarios...

Neokleous, Theoni




SciTech Connect (OSTI)

We report the discovery of a new ultra-bright submillimeter galaxy (SMG) behind the Small Magellanic Cloud (SMC). This SMG is detected as a 43.3 {+-} 8.4 mJy point source (MM J01071-7302, hereafter MMJ0107) in the 1.1 mm continuum survey of the SMC by AzTEC on the ASTE telescope. MMJ0107 is also detected in the radio (843 MHz), Herschel/SPIRE, Spitzer MIPS 24 {mu}m, all IRAC bands, Wide-field Infrared Survey Explorer, and near-infrared (J, H, K{sub S} ). We find an optical (U, B, V) source, which might be the lensing object, at a distance of 1.''4 from near-infrared and IRAC sources. Photometric redshift estimates for the SMG using representative spectral energy distribution templates show the redshifts of 1.4-3.9. We estimate total far-infrared luminosity of (0.3-2.2) Multiplication-Sign 10{sup 14} {mu}{sup -1} L{sub Sun} and a star formation rate of 5600-39, 000 {mu}{sup -1} M{sub Sun} yr{sup -1}, where {mu} is the gravitational magnification factor. This apparent extreme star formation activity is likely explained by a highly magnified gravitational lens system.

Takekoshi, Tatsuya; Minamidani, Tetsuhiro; Sorai, Kazuo; Habe, Asao [Department of Cosmosciences, Graduate School of Science, Hokkaido University, Sapporo 060-0810 (Japan); Tamura, Yoichi; Kohno, Kotaro [Institute of Astronomy, University of Tokyo, Osawa, Mitaka, Tokyo 181-0015 (Japan); Oogi, Taira [Department of Physics, Faculty of Science, Hokkaido University, Sapporo 060-0810 (Japan); Ezawa, Hajime; Komugi, Shinya; Mizuno, Norikazu; Muller, Erik; Kawamura, Akiko [Chile Observatory, National Astronomical Observatory, Mitaka, Tokyo 181-8588 (Japan); Oshima, Tai [Nobeyama Radio Observatory, National Astronomical Observatory of Japan, Minamimaki, Minamisaku, Nagano 384-1305 (Japan); Scott, Kimberly S. [North American ALMA Science Center, National Radio Astronomy Observatory, Charlottesville, VA 22903 (United States); Austermann, Jason E. [Center for Astrophysics and Space Astronomy, University of Colorado, Boulder, CO 80309 (United States); Tosaki, Tomoka [Joetsu University of Education, Joetsu, Niigata 943-8512 (Japan); Onishi, Toshikazu [Department of Physical Science, Osaka Prefecture University, Gakuen 1-1, Sakai, 599-8531 Osaka (Japan); Fukui, Yasuo [Department of Astrophysics, Nagoya University, Chikusa-ku, Nagoya 464-8602 (Japan); Matsuo, Hiroshi [Advanced Technology Center, National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan); Aretxaga, Itziar [Instituto Nacional de Astrofisica, Optica y Electronica (INAOE), 72000 Puebla (Mexico); and others



JOURNAL DE PHYSIQUE Colloque C2, supplment au n 3, Tome 40, mars 1979, page C2-261 MbSSBAUER SPECTROSCOPY ON NICKEL-ZINC FERRITES+  

E-Print Network [OSTI]

SSBAUER SPECTROSCOPY ON NICKEL-ZINC FERRITES+ T.M. Uen++ *and P.K. Tseng** ^Department of Physios, National Tsing, Taiwan, Republic of China RΓ©sumΓ©.- La structure magnΓ©tique hyperfine du systΓ¨me ZnxNij-xFezO^ (ferrite de le mΓͺme type de ferrite avec x Γ©gal Γ  0,3; 0,5 et 0,65 Γ  diffΓ©rentes tempΓ©ratures en-dessous du point

Boyer, Edmond


Tuning of defects in ZnO nanorod arrays used in bulk heterojunction solar cells  

E-Print Network [OSTI]

by radio frequency magnetron sputtering. J Mater Res 2005, 20:1574–1579. 55. Cui J: Zinc oxide nanowires. Mater Charact 2012, 64:43–52. 56. Fan Z, Wang D, Chang P-C, Tseng W-Y, Lu JG: ZnO nanowire field-effect transistor and oxygen sensing property. Appl... to 130 nm in diameter and ca. 800 nm in length. Figure 1d,e shows cross-sectional images of the solar cell devices produced herein, which will be discussed later. Results and discussion Firstly, we present the PL data on our samples together with IR...

Iza, Diana C; Muρoz-Rojas, David; Jia, Quanxi; Swartzentruber, Brian; MacManus-Driscoll, Judith L



Nanoparticles Stabilize Thin Polymer Films: A Fundamental Study to Understand the Phenomenon  

SciTech Connect (OSTI)

In this project we have successfully married an experimental β?? theoretical collaboration between the University of Delaware research group and Sandia National Laboratories. To do this Prof. Mackay supervised graduate students, Ms. Erica Tzu-Chia Tseng and Mr. Wenluan Zhang, who performed experiments, and a postdoctoral fellow, Dr. Venkat Padmanabhan, who performed theoretical modeling in his laboratory and interacted with Dr. Amalie Frischknecht, a theoretician at SNL. Drs. Padmanabhan and Frischknecht had weekly teleconferences on Tuesday mornings to discuss progress and had 2-3 face-to-face meetings per year. Dr. Frischknecht was funded on her part through CINT to allow this partnership. This unique collaborative effort of placing a theoretician within a group of experimentalists has tremendously aided experimental progress since the collaborators are intimately familiar with both the experimental and theoretical efforts. Furthermore development of new theoretical tools to interpret experimental results has resulted in rational verification and enhanced investigation of parameter space.

Mackay, Michael [University of Delaware] [University of Delaware



Submillimeter Galaxies at z~2: Evidence for Major Mergers & Constraints on Lifetimes, IMF and CO-H2 Conversion Factor  

E-Print Network [OSTI]

We report sub-arcsecond resolution IRAM PdBI millimeter CO interferometry of four z~2 submillimeter galaxies (SMGs), and sensitive CO (3-2) flux limits toward three z~2 UV-/optically selected star forming galaxies. The new data reveal for the first time spatially resolved CO gas kinematics in the observed SMGs. Two of the SMGs show double or multiple morphologies, with complex, disturbed gas motions. The other two SMGs exhibit CO velocity gradients of ~500 km/s across 0.2 arcsec (1.6 kpc) diameter regions, suggesting that the star forming gas is in compact, rotating disks. Our data provide compelling evidence that these SMGs represent extreme, short-lived 'maximum' star forming events in highly dissipative mergers of gas rich galaxies. The resulting high mass surface and volume densities of SMGs are similar to those of compact quiescent galaxies in the same redshift range, and much higher than those in local spheroids. From the ratio of the comoving volume densities of SMGs and quiescent galaxies in the same mass and redshift ranges, and from the comparison of gas exhaustion time scales and stellar ages, we estimate that the SMG phase duration is about 100 Myrs. Our analysis of SMGs and optically/UV selected high redshift star forming galaxies supports a 'universal' Chabrier IMF as being valid over the star forming history of these galaxies. We find that the 12CO luminosity to total gas mass conversion factors at z~2-3 are probably similar to those assumed at z~0. The implied gas fractions in our sample galaxies range from 20 to 50%.

L. J. Tacconi; R. Genzel; I. Smail; R. Neri; S. C. Chapman; R. J. Ivison; A. Blain; P. Cox; A. Omont; F. Bertoldi; T. Greve; N. M. Foerster Schreiber; S. Genel; D. Lutz; A. M. Swinbank; A. E. Shapley; D. K. Erb; A. Cimatti; E. Daddi; A. J. Baker



Concordant plutonium-241-americium-241 dating of environmental samples: results from forest fire ash  

SciTech Connect (OSTI)

We have measured the Pu, {sup 237}Np, {sup 241}Am, and {sup 151}Sm isotopic systematics for a set of forest fire ash samples from various locations in the western U.S. including Montana, Wyoming, Idaho, and New Mexico. The goal of this study is to develop a concordant {sup 241}Pu (t{sub 1/2} = 14.4 y)-{sup 241}Am dating method for environmental collections. Environmental samples often contain mixtures of components including global fallout. There are a number of approaches for subtracting the global fallout component for such samples. One approach is to use {sup 242}/{sup 239}Pu as a normalizing isotope ratio in a three-isotope plot, where this ratio for the nonglobal fallout component can be estimated or assumed to be small. This study investigates a new, complementary method of normalization using the long-lived fission product, {sup 151}Sm (t{sub 1/2} = 90 y). We find that forest fire ash concentrates actinides and fission products with {approx}1E10 atoms {sup 239}Pu/g and {approx}1E8 atoms {sup 151}Sm/g, allowing us to measure these nuclides by mass spectrometric (MIC-TIMS) and radiometric (liquid scintillation counting) methods. The forest fire ash samples are characterized by a western U.S. regional isotopic signature representing varying mixtures of global fallout with a local component from atmospheric testing of nuclear weapons at the Nevada Test Site (NTS). Our results also show that {sup 151}Sm is well correlated with the Pu nuclides in the forest fire ash, suggesting that these nuclides have similar geochemical behavior in the environment. Results of this correlation indicate that the {sup 151}Sm/{sup 239}Pu atom ratio for global fallout is {approx}0.164, in agreement with an independent estimate of 0.165 based on {sup 137}Cs fission yields for atmospheric weapons tests at the NTS. {sup 241}Pu-{sup 241}Am dating of the non-global fallout component in the forest fire ash samples yield ages in the late 1950's-early 1960's, consistent with a peak in NTS weapons testing at that time. The age results for this component are in agreement using both {sup 242}Pu and {sup 151}Sm normalizations, although the errors for the {sup 151}Sm correction are currently larger due to the greater uncertainty of their measurements. Additional efforts to develop a concordant {sup 241}Pu-{sup 241}Am dating method for environmental collections are underway with emphasis on soil cores.

Goldstein, Steven J [Los Alamos National Laboratory; Oldham, Warren J [Los Alamos National Laboratory; Murrell, Michael T [Los Alamos National Laboratory; Katzman, Danny [Los Alamos National Laboratory