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Synthesis of Gold Nanoparticles by Leaves of Zero-Calorie Sweetener Herb (Stevia rebaudiana) and Their Nanoscopic Characterization by Spectroscopy and Microscopy

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International Journal of Green Nanotechnology: Physics and Chemistry 2010年第2期1卷 P118-P124页

作者： Mishra, Anuj N. Bhadauria, Seema Gaur, Mulayam S. Pasricha, Renu Kushwah, Brajesh S. Microbiology and Nanotechnology Research Lab R. B. S. College Agra India Department of Physics Hindustan College of Science and Technology Mathura India Material Characterization Division National physical laboratory (CSIR lab) New Delhi India Department of Mechanical Engineering Faculty of Engineering Technology R. B. S. College Agra India

In this research work, gold nanostructures with different shapes, such as octahedrons, hexagons and triangles, have been synthesized within 20 min by reducing gold chloride (HAuCl₄) with dried, powdered Stevia rebaudiana, leaves, previously not exploited for the synthesis of gold nanoparticles. The nanoparticles were characterized and investigated by ultraviolet-visible (UV-Vis) spectrophotometry, high-resolution transmission electron microscopy (HR-TEM), energy-dispersive X-ray (EDX) spectroscopy, and X-ray diffraction (XRD). The UV-Vis spectrum of the aqueous medium containing gold nanostructures showed a peak at 539 nm corresponding to the surface plasmon resonance band (SPR) of gold nanoparticles. HR-TEM micrograph showed the formation of well-dispersed octahedral gold nanoparticles of size 8-20 nm. XRD spectrum of the gold nanoparticles "exhibited Bragg's pattern of reflection.". © 2009 Copyright Taylor and Francis Group, LLC.

关键词： gold nanoparticles Stevia rebaudiana transmission electron microscope X-ray diffraction

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Many Task Computing for modeling the fate of oil discharged from the Deep Water Horizon well blowout

Many Task Computing for modeling the fate of oil discharged ...

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Workshop on Many-Task Computing on Grids and Supercomputers, MTAGS

作者： A. Srinivasan M. LeHenaff V. H. Kourafalou W. C. Thacker N. F. Tsinoremas J. Helgers C. B. Paris H. Kang M. Iskandarani J. P. Zysman O. M. Knio Meteorology and Physical Oceanography Division University of Miami Miami FL Center for Computational Science University of Miami Miami FL USA Applied Marine Physics Division University of Miami Miami FL USA Cooperative Institute of Marine and Atmospheric Science Atlantic Meteorological and Oceanographic Laboratory University of Miami Miami FL Cooperative Institute of Marine and Atmospheric Science Atlantic Meteorological and Oceanographic Laboratory Miami FL Center for Computational Science University of Miami Miami FL Computer Science Department University of Miami Miami FL Dept of Mechanical Engineering Johns Hopkins University Baltimore MD

The Deep Water Horizon well blowout on April 20th 2010 discharged between 40,000-1.2 million tons of crude oil into the Gulf of Mexico. In order to understand the fate and impact of the discharged oil, particularly on the environmentally sensitive Florida Keys region, we have implemented a multi-component application which consists of many individual tasks that utilize a distributed set of computational and data management resources. The application consists of two 3D ocean circulation models of the Gulf and South Florida and a 3D oil spill model. The ocean models used here resolve the Gulf at 2 km and the South Florida region at 900 m. This high resolution information on the ocean state is then integrated with the oil model to track the fate of approximately 10 million oil particles. These individual components execute as MPI based parallel applications on a 576 core IBM Power 5 cluster and a 5040 core Linux cluster, both operated by the Center for Computational science, University of Miami. The data and workflow between is handled by means of a custom distributed software framework built around the Open Project for Networked Data Access Protocol (OPeNDAP). In this paper, we present this application as an example of Many Task Computing, report on the execution characteristics of this application, and discuss the challenges presented by the many task distributed workflow involving heterogeneous components. The application is a typical example from the ocean modeling and forecasting field and imposes soft timeliness and output quality constraints on top of the traditional performance requirements.

关键词： Petroleum Computational modeling Oceans Predictive models Data models Biological system modeling Electronic mail

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Correction to "Multiuser Switched Diversity Scheduling Systems with Per-User Threshold" [May 10 1321-1326]

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IEEE Transactions on Communications 2010年第12期58卷 3631-3631页

作者： Haewoon Nam Mohamed-Slim Alouini Mobile Devices Technology Office Motorola Inc. Austin TX USA Electrical Engineering Program Division of Physical and Chemical Sciences and Engineering King Abdullah University for Science and Technology Thuwal Saudi Arabia

In the above titled paper (ibid., vol. 58, no. 5, pp. 1321-1326), Fig. 1 was incorrectly duplicated in the place of Fig. 2. The correct Fig. 2 is presented here.

关键词： Scheduling Diversity methods

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Erratum to: Robot-assisted modifications of gait in healthy individuals

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Experimental Brain Research 2010年第4期202卷 943-943页

作者： Kim, Seok Hun Banala, Sai K. Brackbill, Elizabeth A. Agrawal, Sunil K. Krishnamoorthy, Vijaya Scholz, John P. School of Physical Therapy and Rehabilitation Sciences University of South Florida Tampa USA Department of Mechanical Engineering University of Delaware Newark USA Division of Physical Therapy Department of Rehabilitation Medicine Emory University Atlanta USA Department of Physical Therapy University of Delaware Newark USA Biomechanics and Movement Science Program University of Delaware Newark USA

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Constraints on dark matter models from a Fermi LAT search for high-energy cosmic-ray electrons from the Sun

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physical Review D 2011年第3期84卷 032007-032007页

作者： M. Ajello W. B. Atwood L. Baldini G. Barbiellini D. Bastieri R. Bellazzini B. Berenji R. D. Blandford E. D. Bloom E. Bonamente A. W. Borgland E. Bottacini A. Bouvier J. Bregeon M. Brigida P. Bruel R. Buehler S. Buson G. A. Caliandro R. A. Cameron P. A. Caraveo C. Cecchi E. Charles A. Chekhtman S. Ciprini R. Claus J. Cohen-Tanugi S. Cutini A. de Angelis F. de Palma C. D. Dermer S. W. Digel E. do Couto e Silva P. S. Drell C. Favuzzi S. J. Fegan W. B. Focke Y. Fukazawa P. Fusco F. Gargano N. Gehrels S. Germani N. Giglietto F. Giordano M. Giroletti T. Glanzman G. Godfrey I. A. Grenier S. Guiriec M. Gustafsson D. Hadasch G. Iafrate G. Jóhannesson A. S. Johnson T. Kamae H. Katagiri J. Kataoka M. Kuss L. Latronico A. M. Lionetto F. Longo F. Loparco M. N. Lovellette P. Lubrano M. N. Mazziotta J. E. McEnery P. F. Michelson T. Mizuno C. Monte M. E. Monzani A. Morselli I. V. Moskalenko S. Murgia M. Naumann-Godo J. P. Norris E. Nuss T. Ohsugi N. Omodei E. Orlando J. F. Ormes M. Ozaki D. Paneque J. H. Panetta M. Pesce-Rollins M. Pierbattista F. Piron S. Rainò R. Rando M. Razzano A. Reimer O. Reimer S. Ritz T. L. Schalk C. Sgrò J. Siegal-Gaskins E. J. Siskind P. D. Smith G. Spandre P. Spinelli D. J. Suson H. Takahashi T. Tanaka J. G. Thayer J. B. Thayer L. Tibaldo G. Tosti E. Troja T. L. Usher J. Vandenbroucke V. Vasileiou G. Vianello N. Vilchez A. P. Waite P. Wang B. L. Winer K. S. Wood Z. Yang S. Zimmer W. W. Hansen Experimental Physics Laboratory Kavli Institute for Particle Astrophysics and Cosmology Department of Physics and SLAC National Accelerator Laboratory Stanford University Stanford California 94305 USA Santa Cruz Institute for Particle Physics Department of Physics and Department of Astronomy and Astrophysics University of California at Santa Cruz Santa Cruz California 95064 USA Istituto Nazionale di Fisica Nucleare Sezione di Pisa I-56127 Pisa Italy Istituto Nazionale di Fisica Nucleare Sezione di Trieste I-34127 Trieste Italy Dipartimento di Fisica Università di Trieste I-34127 Trieste Italy Istituto Nazionale di Fisica Nucleare Sezione di Padova I-35131 Padova Italy Dipartimento di Fisica “G. Galilei ” Università di Padova I-35131 Padova Italy Istituto Nazionale di Fisica Nucleare Sezione di Perugia I-06123 Perugia Italy Dipartimento di Fisica Università degli Studi di Perugia I-06123 Perugia Italy Dipartimento di Fisica “M. Merlin” dell’Università e del Politecnico di Bari I-70126 Bari Italy Istituto Nazionale di Fisica Nucleare Sezione di Bari 70126 Bari Italy Laboratoire Leprince-Ringuet École polytechnique CNRS/IN2P3 Palaiseau France Institut de Ciències de l’Espai (IEEE-CSIC) Campus UAB 08193 Barcelona Spain INAF-Istituto di Astrofisica Spaziale e Fisica Cosmica I-20133 Milano Italy Artep Inc. 2922 Excelsior Springs Court Ellicott City Maryland 21042 USA and resident at Naval Research Laboratory Washington D.C. 20375 USA ASI Science Data Center I-00044 Frascati (Roma) Italy Laboratoire Univers et Particules de Montpellier Université Montpellier 2 CNRS/IN2P3 Montpellier France Agenzia Spaziale Italiana (ASI) Science Data Center I-00044 Frascati (Roma) Italy Dipartimento di Fisica Università di Udine and Istituto Nazionale di Fisica Nucleare Sezione di Trieste Gruppo Collegato di Udine I-33100 Udine Italy Space Science Division Naval Research Laboratory Washington D.C. 20375-5352 USA Department of Physical Sciences Hiroshima

During its first year of data taking, the Large Area Telescope (LAT) onboard the Fermi Gamma-Ray Space Telescope has collected a large sample of high-energy cosmic-ray electrons and positrons (CREs). We present the results of a directional analysis of the CRE events, in which we searched for a flux excess correlated with the direction of the Sun. Two different and complementary analysis approaches were implemented, and neither yielded evidence of a significant CRE flux excess from the Sun. We derive upper limits on the CRE flux from the Sun’s direction, and use these bounds to constrain two classes of dark matter models which predict a solar CRE flux: (1) models in which dark matter annihilates to CREs via a light intermediate state, and (2) inelastic dark matter models in which dark matter annihilates to CREs.

关键词： TELESCOPES FERMI Gamma-ray Space Telescope (Spacecraft) COSMIC rays ELECTRON-positron interactions LEPTON interactions POSITRONS

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Connector faculty: A friendly face for early engineering students

Connector faculty: A friendly face for early engineering stu...

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2009 ASEE Annual Conference and Exposition

作者： Briedis, Daina Buch, Neeraj Collins-Eaglin, Jan Ehrlich, Nathaniel Fleming, Denise Hinds, Timothy Sticklen, Jon Urban-Lurain, Mark Wolff, Thomas Department of Chemical Engineering and Materials Science Michigan State University United States Department of Civil and Environmental Engineering Michigan State University United States Cornerstone Engineering and Residential Experience Program Michigan State University United States Michigan State University United States United States College of Engineering Michigan State University United States Michigan State University College of Engineering Undergraduate Studies Department of Mechanical Engineering United States Applied Engineering Sciences College of Engineering Michigan State University United States Computer Science and Engineering Department Michigan State University United States Division of Science and Mathematics Education College of Natural Science Michigan State University United States Engineering for Undergraduate Studies Michigan State University United States

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Experimental characterization of acoustic source mechanisms of large wind turbines according to power regulation methods

Experimental characterization of acoustic source mechanisms ...

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38th International Congress and Exposition on Noise Control engineering 2009, INTER-NOISE 2009

作者： Lee, Gwang-Se Shin, Su-Hyun Cheong, Cheolung Jung, Sung-Soo Department of Mechanical Engineering Pusan National University 30 Jangjeon-dong Geumjeong-gu Busan 609-745 Korea Republic of Fluid Flow/Acoustics and Vibration Group Division of Physical Metrology Korea Research Institute of Standards and Science Daejeon Korea Republic of

ISBN: (纸本)9781615676903

Previous study (Cheong et al., 2006) where the characteristics of acoustic emissions of wind turbines(WTs) has been investigated according to the methods of power regulation, showed that the acoustic power of wind turbine (WT) using stall control for power regulation is more correlated with wind speed than that using pitch control. In this paper extending this work, the noise generation characteristics of large modern upwind WTs are experimentally indentified according to the power regulation methods. First, the sound measurement procedure of IEC 61400-11 are applied to evaluate noise emission from 1.5 MW and 660 kW WTs using the stall regulation and pitch control for power regulation. One-third octave band spectrums normalized by using the scale law of the velocity dependence of the inflow broadband noise and airfoil-self noise show that for 1.5 MW WT using stall control, the inflow-turbulence noise is dominant in the frequency range over 800 Hz and the airfoil self-noise is dominant below 800 Hz. For 660 kW WT using the pitch regulation, the inflow turbulence noise does not significantly contribute. To further investigate the noise generation mechanisms, the distribution of noise sources in rotor plane is measured by using the Beam-forming measurement system (B&K 7768, 7752, WA0890)consisting of 48 microphones. The array results for the 660 kW WT show that all noise is produced during the downward movement of the blades. This shows good agreement with a theoretical result using the semi-empirical formula with the parameters: convective amplification;trailing edge noise directivity;flow-speed dependence. This agreement implies that the trailing edge noise is dominant over the whole frequency range of the noise from the 660 kW WT using the pitch control for power regulation.

关键词： Wind turbines

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He ion irradiation damage in Al/Nb multilayers

He ion irradiation damage in Al/Nb multilayers

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作者： Li, Nan Martin, M.S. Anderoglu, O. Misra, A. Shao, L. Wang, H. Zhang, X. Department of Mechanical Engineering Materials Science and Engineering Program Texas A and M University College Station TX 77843-3123 United States Department of Nuclear Engineering Texas A and M University College Station TX 77843-3133 United States Materials Physics and Application Division Los Alamos National Laboratory Los Alamos NM 87545 United States Department of Electrical and Computer Engineering Texas A and M University College Station TX 77843-3128 United States

We investigate the evolution of microstructure and mechanical properties of sputter-deposited Al/Nb multilayers with miscible fcc/bcc type interface and individual layer thickness, h, of 1-200 nm, subjected to helium ion irradiations: 100 keV He+ ions and a fluence of 6 10 16/cm2. Helium bubbles, 1-2 nm in diameter, are observed. When h is greater than 25 nm, hardnesses of irradiated multilayers barely change, whereas radiation hardening is more significant at smaller h. Transmission electron microscopy and scanning transmission electron microscopy studies reveal the formation of a thin layer of Nb3 Al intermetallic phase along the Al/Nb interface as a consequence of radiation induced intermixing. The dependence of radiation hardening on h is interpreted by using a composite model considering the formation of the hard Nb3 Al intermetallic layer. © 2009 American Institute of Physics.

关键词： High resolution transmission electron microscopy

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Nanoscale duplex oxide growth during early stages of oxidation of Cu-Ni(100)

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physical Review B 2009年第13期80卷 134106-134106页

作者： Guangwen Zhou Dillon D. Fong Liang Wang Paul H. Fuoss Peter M. Baldo Loren J. Thompson Jeffrey A. Eastman Department of Mechanical Engineering and Multidisciplinary Program in Materials Science and Engineering State University of New York Binghamton New York 13902 USA Materials Science Division Argonne National Laboratory Argonne Illinois 60439 USA Department of Materials Science and Engineering University of Illinois at Urbana–Champaign Urbana Illinois 61801 USA

A combination of real-time in situ synchrotron x-ray diffraction and ex situ transmission electron microscopy is utilized to investigate the early stages of oxidation of Cu-Ni(100). Sequential formation of NiO and Cu2O oxides was observed by increasing oxygen partial pressure, and the Cu2O phase was identified to form preferentially on top of NiO nanoislands. The origin of this unexpected phenomenon is attributed to localized enrichment of Cu atoms accompanied with NiO growth, which thermodynamically drives the nanoscale Cu2O/NiO duplex oxide growth.

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Simultaneous temperature and magnetization transfer (MT) monitoring during high-intensity focused ultrasound (HIFU) treatment: Preliminary investigation on ex vivo porcine muscle

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Journal of Magnetic Resonance Imaging 2009年第3期30卷 596-605页

作者： Peng, Hsu-Hsia Huang, Teng-Yi Tseng, Wen-Yih Isaac Lin, En-Li Chung, Hsiao-Wen Wu, Chih-Ching Wang, Yu-Shun Chen, Wen-Shiang Department of Biomedical Engineering and Environmental Sciences National Tsing Hua University Hsinchu Taiwan Department of Electrical Engineering National Taiwan University of Science and Technology Taipei 106 No. 43 Sec.4 Keelung Rd. Taiwan Center for Optoelectronic Biomedicine National Taiwan University College of Medicine Taipei Taiwan Department of Medical Imaging National Taiwan University Hospital Taipei Taiwan Department of Electrical Engineering National Taiwan University Taipei Taiwan Department of Mechanical Engineering National Taiwan University Taipei Taiwan Division of Medical Engineering Research National Health Research Institutes Miaoli Taiwan Department of Physical Medicine and Rehabilitation National Taiwan University Hospital Taipei Taiwan

Purpose: To measure temperature change and magnetization transfer ratio (MTR) simultaneously during high-intensity focused ultrasound (HIFU) treatment. Materials and Methods: This study proposed an inter-leaved dual gradient-echo technique to monitor the heat and tissue damage brought to the heated tissue. The technique was applied to tissue samples to test its efficacy. Results: Ex vivo experiments on the porcine muscle demonstrated that both temperature changes and MTR exhibited high consistency in localizing the heated regions. As the heat dissipated after the treatment, the temperature of the heated regions decreased rapidly but MTR continued to be elevated. Moreover, thermal dose (TD) maps derived from the temperature curves demonstrated a sharp margin in the heated regions, but MTR maps may show a spatial gradient of tissue damage, suggesting complimentary information provided by these two measures. Conclusion: In a protocol of spot-by-spot heating over a large volume of tissue, MTR provides additional values to mark the locations of previously heated regions. By continuously recording the locations of heated spots, MTR maps could help plan the next target spots appropriately, potentially improving the efficiency of HIFU treatment and reducing undesirable damage to the normal tissue. © 2009 Wiley-Liss, Inc.

关键词： High-intensity focused ultrasound Magnetization transfer Temperature Thermal dose Thermotherapy Tissue damage

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