NIST Technicalendar August 10 to August 14, 2009 The NIST Technicalendar is issued each Friday. All items MUST be submitted electronically from this web page by 12:00 NOON each Wednesday unless otherwise stated in the NIST Technicalendar. The address for online weekly editions of the NIST Technicalendar and NIST Administrative Calendar is: http://www.nist.gov/tcal.

In this Issue: Meetings at NIST Meetings Elsewhere Announcements Talks by NIST Personnel NIST Web Site Announcements NIST Administrative Calendar (current)   NIST Vacancy Announcements (current)

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No Scheduled Events

No Scheduled Events

1:00 PM - Negative Refraction and Negative Radiation Pressure
2:00 PM - DETERMINING THE HYDRODYNAMIC SIZE AND SHAPE OF FLUORESCENT BIOMOLECULES BY PROBING THEIR SINGLE-MOLECULE BROWNIAN MOTION

2:00 PM - Morphological Evolution during the Crystallization of Polylactide: Effect of Pre-Ordering State and Lattice Interaction

10:45 AM - Renewable Polylactide / Polymerized Soybean Oil Blends Compatibilized by Block Copolymers
1:30 PM - Functional Nanomaterials Based on Block Copolymer Templates

8/10 -- MONDAY

No Scheduled Events

8/11 -- TUESDAY

No Scheduled Events

8/12 -- WEDNESDAY

1:00 PM - 2009 RESEARCH ADVISORY COLLOQUIUM SERIES: Negative Refraction and Negative Radiation Pressure
Four decades ago, V. Veselago derived the electromagnetic properties of a hypothetical material having simultaneously-negative values of electric permittivity and magnetic permeability. Such a "left-handed" material was predicted to exhibit a number of exotic properties including a negative index of refraction and a negative response to radiation pressure (pull). Since left-handed materials are not available in nature, considerable efforts are currently under way to implement them under the form of artificial "metamaterials" – composite media with tailored bulk optical characteristics resulting from constituent structures which are smaller than the effective wavelength in the medium. This talk shows how surface-plasmon modes propagating in a stacked array of metal-insulator-metal (MIM) waveguides can be harnessed to yield a volumetric left-handed metamaterial characterized by an in-plane-isotropic index of refraction which is negative over a broad portion of the visible-frequency range. By sculpting this metamaterial with a focused-ion beam, micro-cantilevers are realized and used to demonstrate for the first time, a negative radiation pressure. A negative "super-pressure" of magnitude significantly greater than the largest photon pressure achievable under normal circumstances – that experienced by a perfect mirror, is predicted and experimentally verified.
Henri Lezec , Center for Nanoscale Science and Technology, NIST.
Administration Bldg, Green Auditorium. (NIST Contact: Ajit Jillavenkatesa, 301-975-5089, ajit.jilla@nist.gov)

2:00 PM - CNST NANOFABRICATION RESEARCH GROUP SEMINAR: DETERMINING THE HYDRODYNAMIC SIZE AND SHAPE OF FLUORESCENT BIOMOLECULES BY PROBING THEIR SINGLE-MOLECULE BROWNIAN MOTION
Monitoring the Brownian motion of a fluorescent biomolecule in solution renders information regarding its hydrodynamic shape and size under physiological conditions. In contrast to the translational diffusion of a fluorescent biomolecule that typically occurs on the micro- to millisecond time scale, its size is more sensitive to its rotational diffusion dynamics occurring on the pico- and nanosecond time scale. While the former is conveniently obtained from a conventional fluorescence correlation spectroscopy experiment, the latter is generally obtained from a time-resolved fluorescence anisotropy experiment upon pulsed excitation, which is inherently limited to the measurement of rotational correlation times not exceeding the fluorescence lifetime of the fluorophore. To circumvent this problem and to provide an accurate measurement of the rotational diffusion time of a biological macromolecule, which is typically in the order of tens of nanoseconds, we apply a recently developed photon counting technology for the measurement of fluorescence correlation from picoseconds to seconds by registering distinct photon arrival times with picosecond resolution. Utilization of this technique in a polarization-sensitive manner along with an exact theoretical analysis in terms of the second-order correlation function allows us to probe simultaneously the translational and rotational diffusion of fluorescent biomolecules. We demonstrate the application of this novel single-molecule methodology for the determination of the hydrodynamic size and shape of small dye molecules (with sizes below 10 Å) as well as of fluorescent proteins.
Sandeep Pallikkuth , Postdoctoral.
Bldg 217, Rm H107. (NIST Contact: Andrew Berglund, 301-975-2844, andrew.berglund@nist.gov)


8/13 -- THURSDAY

2:00 PM - MATERIALS AND CONSTRUCTION RESEARCH DIVISION SEMINAR: Morphological Evolution during the Crystallization of Polylactide: Effect of Pre-Ordering State and Lattice Interaction
The evolution of crystal morphology reflects the possible paths for molecules to reach more stable state. Upon selected growth environments, molecules can behave differently. The present studies are concerned with the crystal morphologies of biodegradable polylactide (PLA) developing respectively in the solution and on the surface. The lenticular crystals of PLA were found to grow in the dilute solution during isothermal growth course. The growth of lenticular crystal appears simply a kinetically-favored result under the influence of molecular pre-ordering state in the solution. Due to the unstable nature, the lenticular crystal further transforms to truncated lozenge, within which a facet thickened region develops. Apparently a novel reorganization process initiated from crystal center is involved for observed morphological evolution. As crystallization of PLA molecules occurs on a crystalline substrate under the influence of lattice match, molecules join the crystal growth by forming a ladder-like pattern on each growth layer. This observation provides another prospect of chain tilt within lamellae, and is closely related to observed collaborative bending growth. Both molecular weight and growth temperature are influential to the occurrence of ladder-like pattern of molecular deposition. Therefore except for lattice match, the critical role played by overcrowding on fold surface is also manifested.
Jrjeng Ruan , Assistant Professor, National Cheng Kung University.
Bldg 226, Rm. B221. (NIST Contact: Li-Piin Sung, 301-975-6737, lipiin@nist.gov)


8/14 -- FRIDAY

10:45 AM - NIST CENTER FOR NEUTRON RESEARCH SEMINAR: Renewable Polylactide / Polymerized Soybean Oil Blends Compatibilized by Block Copolymers
In recent years, there has been an increasing emphasis on finding alternatives to replace traditional non-degradable petroleum-based plastics. Of great interest and environmental importance are renewable feedstocks for polymeric raw materials. Polylactide is one of the most extensively studied polymers derived from an annually renewable resource, due to its biocompatibility and biodegradability for biomedical applications as well as its competitive physical properties. The brittleness of the polymer is one of the main impediments to its use in many traditional petroleum-based polymer applications. One method of toughening a brittle polymer is to blend it with a rubbery material, creating micron-sized rubber particles in the brittle polymer matrix. In this study, all-renewable blends of polylactide and polymerized soybean oil (polySOY) were prepared with melt blending. Free radical polymerization was used to prepare crosslinked polySOY samples with a variety of molecular weight distributions and gel fractions. The conjugation of the double bonds on the soybean oil triglyceride molecule greatly reduced the concentration of crosslinking agent required for the polymerization. The polySOY samples were melt blended with polylactide, and polymerizing the soybean oil eliminated soybean oil loss and phase inversion, both of which occur when unmodified soybean oil is melt blended with polylactide. The particle size and tensile toughness of the blend were found to strongly depend on the gel fraction (fraction of insoluble material) of the polySOY. The tensile toughness was increased to as high as four times that of neat polylactide.
Megan Robertson , University of Minnesota. ,.
235 Bldg, Rm. E100. (NIST Contact: Dan Neumann, 301-975-5252, dan@nist.gov)

1:30 PM - POLYMERS DIVISION SEMINAR: Functional Nanomaterials Based on Block Copolymer Templates
Nanoporous templates have been widely used for the development of new functional nanostructured materials suitable for electronics, optics, magnetism, and energy storage materials. We have prepared nanoporous templates by using thin films of mixtures of polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) and PMMA homopolymers, followed by UV irradiation and rinsing with acetic acid to remove all the PMMA phases. These templates have cylindrical nanoholes spanning the entire thickness of the film. Some applications of nanoporous templates are introduced: a) anti-reflective coating , b) the preparation of conducting polymer nanowires of poly(pyrrole), poly(3,4-ethylenedioxythiopene) onto a glass coated with indium-tin-oxide, and c) the separation membranes for biomaterials. We found that when the pore fraction of nanoholes in the film was ~0.68, almost zero reflectance at a specific wavelength, which can be changed with film thickness, was achieved at visible wavelengths. Furthermore, ultra high density array of conducting nanowires was successfully prepared onto various substrates including flexible polymer. These nanoporous films were found to be very effective for the separation of human Rhinovirus type 14 (HRV 14), major pathogen of a common cold in humans, from the buffer solution. Finally, nanoscale patterns with lateral sizes down to ~ 50 nm were fabricated by using atomic force microscopy at room temperature.
Jin Kon Kim , Pohang University of Science and Technology.
224 Bldg, Rm. A312. (NIST Contact: Chris Soles, 301-975-8087, csoles@nist.gov)


ADVANCE NOTICE

8/19/09 10:00 AM - CNST ENERGY RESEARCH GROUP SEMINAR: Applications of Metal-Organic Frameworks Beyond Hydrogen Storage: Way Beyond...
The unique properties of the novel nanoporous materials known as metal-organic frameworks (MOFs) are attracting much interest from communities concerned with storage of hydrogen and other gases, and also for chemical separations. However, the ordered crystalline structures of MOFs and their unique, structurally flexible, nature create opportunities for their use in technically challenging arenas, such as chemical sensing, radiation detection, nanoparticle synthesis, and nanoscale tuning of properties. This presentation will provide an overview of MOF-related research activities at Sandia National Laboratories and will include recent work in the following areas: 1) MOF adaptation to the surfaces of microcantilevers to create a rapid, reversible chemical sensor; 2) synthesis of MOFs with luminescent linkers to create new scintillators; 3) infiltration of MOFs with metal hydrides to create nanoscale hydrogen storage materials; and 4) Ag@MOF nanocomposites with enhanced Raman scattering. Mark D. Allendorf (Ph.D., inorganic chemistry, Stanford University) is a Distinguished Member of the Technical Staff at Sandia/CA, a Fellow of The Electrochemical Society, and formerly that organization's president. He currently leads efforts at Sandia to develop both the fundamental science and applications of MOF compounds. His research interests include chemical sensing, radiation detection, nanoparticle synthesis, and heterostructures for nanoscale electronics. He has published over 100 articles in peer-reviewed journals and conference proceedings.
Mark Allendorf , Sandia National Labs, Livermore, CA 94550.
215 Bldg, Rm. C103-C106. (NIST Contact: Alec Talin, 301-975-4724, albert.talin@nist.gov)

8/19/09 10:00 AM - ,PTC SEMINAR: CoCreate CAD Software Demo
Parametric Technology Corporation (PTC) would like introduce their CoCreate CAD software and related products to the NIST community. The Instrument Development Engineering Group at the NIST Center for Neutron Research (NCNR) has been using CoCreate CAD software and related products for over 15 years. During that time the software has become one of the top explicit modelers. If interested in attending please contact Daniel Adler by phone at x5792 or email at daniel.adler@nist.gov. For more information on this presentation or the CoCreate products please contact Daniel or visit www.ptc.com/products/cocreate.
Cristina Chin , PTC.
Administration Bldg, Lecture Rm. C. (NIST Contact: Daniel Adler, 301-975-5792, daniel.adler@nist.gov)

8/19/09 10:30 AM - CNST ELECTRON PHYSICS GROUP SEMINAR: INDIVIDUAL ATOMS AND MOLECULES ON INSULATING FILMS STUDIED WITH NONCONTACT AFM
We investigated the charge state switching of individual gold and silver adatoms on ultrathin NaCl films on Cu(111) using a qPlus tuning fork atomic force microscope (AFM) operated at 5 Kelvin with oscillation amplitudes in the sub-Ångstrom regime. Charging of a gold adatom by one electron charge increased the force on the AFM tip by a few piconewtons. Employing Kelvin probe force microscopy (KPFM) we also measured the local contact potential difference (LCPD). We observed that the LCPD is shifted depending on the sign of the charge and allows the discrimination of positively charged, neutral, and negatively charged atoms. Furthermore, we modified AFM tips by means of vertical manipulation techniques, i.e. deliberately picking up known adsorbates, to increase spatial resolution. To study the effect of the atomic tip termination we used different well defined tip terminations to image individual pentacene molecules. We compare our experimental results with density functional theory (DFT) calculations to gain insight on the physical origin of contrast formation on the atomic scale.
Leo Gross , Postdoctoral Fellow/IBM Research, Zurich.
Bldg.217, Rm.H107. (NIST Contact: Rachel Cannara, 301-975-4258, rachel.cannara@nist.gov)

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MEETINGS ELSEWHERE


8/10 -- MONDAY

No Scheduled Events

8/11 -- TUESDAY

No Scheduled Events

8/12 -- WEDNESDAY

No Scheduled Events

8/13 -- THURSDAY

No Scheduled Events

8/14 -- FRIDAY

No Scheduled Events

ADVANCE NOTICE

No Scheduled Events

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TALKS BY NIST PERSONNEL

NAVE, G. : ATOMIC DATA FOR INFRARED AND SUB-MM WAVELENGTHS.
XXVII General Assembly of the International Astronomical Union, Rio de Janeiro, Brazil, 8/5.

NAVE, G. : PRECISION LABORATORY WAVELENGTHS OF ATOMIC TRANSITIONS FOR OBSERVATIONS OF QUASAR ABSORPTION SPECTRA.
XXVII General Assembly of the International Astronomical Union, Rio de Janeiro, Brazil, 8/11.

WRIGHT, J. : BLOW-DOWN TESTS CONFIRM ACCURATE CRITICAL NOZZLE FOW MEASUREMENT DURING TRANSIENTS.
7th International Symposium of Fluid Flow Measurement, Anchorage, AK, 8/12.

JOHNSON, A. : COMPARISON OF FIVE NATURAL GAS EQUATIONS OF STATE USED FOR FLOW AND ENERGY MEASUREMENT.
7th International Symposium of Fluid Flow Measurement, Anchorage, AK, 8/13.

SHINDER, I. : DYNAMIC GRAVITATIONAL STANDARD FOR LIQUID FLOW: MODEL AND MEASUREMENTS.
7th International Symposium of Fluid Flow Measurement, Anchorage, AK, 8/13.

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ANNOUNCEMENTS

PUBLICATIONS PRINTING DEADLINE, AUGUST 14, 2009
August 14 is the last day in FY 2009 to submit materials using FY 2009 funds to the Electronic Information and Publications Group (EIPG) for printing at the Department of Commerce or Government Printing Office. To assure timely processing, bring your Editorial Review Board-approved document or administrative printing job and appropriate paperwork to the EIPG office by close of business on Friday, August 14, 2009. The office is located on the mezzanine floor of the NIST Research Library in the Administration Building, Room E220. Questions? Ilse Putman, x2780 or Barbara Silcox, x2146.
NIST Contact: Ilse Putman, 301-975-2780, ilse.putman@nist.gov

VISITOR REGISTRATION FOR NIST EVENTS
Because of heightened security at the NIST Gaithersburg site, members of the public who wish to attend meetings, seminars, lectures, etc. must first register in advance. For more information please call or e-mail the "NIST Contact" for the particular event you would like to attend.
NIST Contact: . ., ., .

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NIST WEB SITE ANNOUNCEMENTS

No Web Site announcements this week.

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For more information, contact Ms. Sharon Hallman, Editor, Stop 2500, National Institute of Standards and Technology, Gaithersburg MD 20899-2500; Telephone: 301-975-TCAL (3570); Fax: 301-926-4431; or Email: tcal@nist.gov.

All lectures and meetings are open unless otherwise stated.

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