NIST Technicalendar July 9 to July 13, 2007 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/.
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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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10:30 AM - Recent Advances in Studies of Dilute Solution Properties of Oligomers and Polymers
11:00 AM - Laponite PEO Dispersions and Soft Glassy Materials: Rheology, dynamics and structure

2:00 PM - Nanomaterials in Biosciences and the Environment
3:00 PM - Toward Fabricating Robust Nanoscale Features: Measuring the Residual Stresses Induced by the Nanoimprint Lithography Process

No Scheduled Events

No Scheduled Events

10:30 AM - Troubleshooting Time-Dependent Density-Functional Theory for Photochemcial Applications: Oxirane.

7/9 -- MONDAY

10:30 AM - POLYMERS DIVISION SEMINAR: Recent Advances in Studies of Dilute Solution Properties of Oligomers and Polymers
We introduce recent advances in studies of dilute solution properties of oligomers and polymers. It is well known that flexible polymer chains with very large molecular weight can be described by the Gaussian chain model. However, as molecular weight decreases, individuality of polymer chains becomes important, and then the Gaussian chain model becomes no longer suitable for oligomers. In this seminar, we will introduce the "helical wormlike chain model" as the model to explain dilute solution properties of both oligomers and polymers, and show examples of analyses of radius of gyration for polystyrene, poly(a-methylstyrene), and their oligomers in Q states determined from static light scattering and small-angle X-ray scattering measurements, and then clarify local chain conformation of these two polymers. In addition, we will show that these two polymers have different temperature dependence of chain dimension in a good solvent because of the difference in local chain conformation.
Masashi Osa , Kyoto University.
224 Bldg, Rm. A315. (NIST Contact: Wen-Li Wu, 301-975-6839, wenli@nist.gov)

11:00 AM - POLYMERS DIVISION SEMINAR: Laponite PEO Dispersions and Soft Glassy Materials: Rheology, dynamics and structure
Formulated laponite-PEO suspensions and gels/glasses to investigate polymer molecular weight effects on the rheology and dynamics of laponite systems. Tuned the rheology of laponite-PEO by varying the molecular weight of PEO. Found that polymer chains below a critical molecular weight melts the laponite glass by speeding up dynamics as evidenced by a reduction in viscosity and change in the autocorrelation function via rheology and dynamic light scattering respectively. Above the PEO critical molecular weight, which scales with the laponite interparticle distance, re-entrance into a glass, or a transition to a gel, occurs due to PEO chains bridging laponite particles forming a polymer-clay network which enhances the elastic modulus. This research resulted in the first demonstration of re-entrant phenomena with an anisotropic charged colloid and polymer system.
Hossein Baghdadi , University of Massachusetts Department of Chemical and Biological Engineering, Amherst, MA, hossein@acad.umass.edu.
224 Bldg, Rm. A312. (NIST Contact: Michael Fasolka, 301-975-8526, michael.fasolka@nist.gov)


7/10 -- TUESDAY

2:00 PM - CHEMICAL SCIENCE AND TECHNOLOGY LABORATORY OFFICE SEMINAR: Nanomaterials in Biosciences and the Environment
Vicki Colvin, Ph.D. , Prof. of Chem. & Chem. Eng., Rice University, Houston, TX.
ACSL, 227 Bldg, Rm. A202. (NIST Contact: Dianne Poster, 301-975-4166, dianne.poster@nist.gov)

3:00 PM - POLYMERS DIVISION SEMINAR: Toward Fabricating Robust Nanoscale Features: Measuring the Residual Stresses Induced by the Nanoimprint Lithography Process
Nanoimprinting lithography (NIL) is an emerging nanofabrication technique, with the advantages of high-throughput, low-cost and high-resolution. In addition to the promise of a next generation lithography for CMOS applications, the thermal embossing form of NIL can directly pattern nanoscale features into functional materials. This differs from patterning sacrificial resist formulations that temporarily act as an etch stop in a subsequent pattern transfer process; the directly imprinted functional pattern is the final structure. For the reliable nanomanufacturing of functional devices with NIL, these structures must be both physically and chemically stable. Quantifying the physical stability or reliability of nanoscale structures first requires high resolution sample shape measurements. In a nanoscale object, a dimension change of just a few nanometers may be unacceptable from an application point of view. It is also critical to quantify how the nanoimprint pattering process itself impacts the material properties related to structural stability. Specifically, it is critical to quantify the viscoelastic deformation process of the imprint process and relate them to the internal or residual stresses induced into the patterns created by NIL. In this study, we quantify the subtle pattern shape evolution during thermal annealing of the imprinted polymer patterns using a suite of complimentary high resolution pattern shape measurements, including critical dimension small angle X-ray scattering (CD-SAXS), specular X-ray reflectivity, visible light diffraction/reflection measurements, and AFM imaging. By monitoring the detailed changes in the pattern we experimentally quantify a pattern decay rate. This decay rate is compared to the timescale for the viscoleastic relaxation mechanism of the material to reveal the levels of residual stress induced by the NIL patterning process. We generally find that highly entangled polymers contain large amounts of residual stress that drive the pattern decay at rates significantly faster than predicted by viscous flow. The level these residual stress can be controlled by mediating the processing conditions such as the imprinting temperature, time and residual layer thickness. In addition to the stress induced pattern decay processes, under some conditions we also evidence a lateral instability or pattern buckling at elevated temperatures, especially when surfactants are used to facilitate the mold release process. These findings will be presented in detail and their implications on fabricating robust nanoscale features with NIL will be discussed.
Yifu Ding , Electronic Materials Group.
224 Bldg, Rm. A312. (NIST Contact: Jack Douglas, 301-975-6779, jack.douglas@nist.gov)


7/11 -- WEDNESDAY

No Scheduled Events

7/12 -- THURSDAY

No Scheduled Events

7/13 -- FRIDAY

10:30 AM - OPTICAL TECHNOLOGY DIVISION SEMINAR: Troubleshooting Time-Dependent Density-Functional Theory for Photochemcial Applications: Oxirane.
Mark Casida , Professor, France.
221 Bldg, Rm. B145. (NIST Contact: Eric Shirley, 301-975-2349, eric.shirley@nist.gov)


ADVANCE NOTICE

7/19/07 11:00 AM - OFFICE OF THE DIRECTOR, NIST SEMINAR: Are We There Yet? Measuring When Robots Are Ready for Deployment
Robots hold much promise as tools that will aid humans in a wide variety of missions and applications. They are being developed for military missions, transportation systems, factory automation, and homeland security, to mention a few examples. Yet there are scant means of objectively and quantifiably being able to determine whether robots are ready to be fielded or how effective they will be in accomplishing a particular mission. There currently are no measures available to compare alternative robotic solutions and select the most suitable one. To address this shortcoming, NIST is working with stakeholders to define application-specific requirements for robot performance, to devise test methods and metrics for evaluating the performance, and to generate consensus standards. This talk will present the challenges in developing a measurement science for robotics and provide examples of the process used in a methodology that abstracts application-specific real world challenges into quantifiable and reproducible tests.
Elena Messina , NIST.
Administration Bldg, Red Auditorium. (NIST Contact: Steve Quirolgico, 301-975-8426, steveq@nist.gov)
Special Assistance Available

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MEETINGS ELSEWHERE


7/9 -- MONDAY

No Scheduled Events

7/10 -- TUESDAY

No Scheduled Events

7/11 -- WEDNESDAY

No Scheduled Events

7/12 -- THURSDAY

No Scheduled Events

7/13 -- FRIDAY

No Scheduled Events

ADVANCE NOTICE

10/4/07 10:00 AM - NIST/DARPA WORKSHOP ON COMPACT X-RAY SOURCES BASED ON INVERSE COMPTON SCATTERING
Ronald Ruth , President and Chief Scientist, Lyncean Technologies, Inc., Palo Alto, CA, ronald_ruth@lynceantech.com. David Moncton , Director, MIT Nuclear Reactor Laboratory, Cambridge, MA, dem@mit.edu. Winthrop J. Brown, MIT Lincoln Laboratory, Frank E Carroll Jr, CEO & Chief Medical Officer, MXISystems, Inc. Mathias Richter, Physikalisch-Technische Bundesanstalt PTB
Bldg, Rm. .
The Executive Conference Center (ECC) 3601 Wilson Boulevard Suite 600 Arlington, Virginia 22201. (NIST Contact: Uwe Arp, 301-975-3233, uwe.arp@nist.gov)

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TALKS BY NIST PERSONNEL

LU, J. : STOCHASTIC MODELING IN GENE EXPRESSION MEASUREMENTS.
The 14th Applied Probability Conference of INFORMS Society, EURANDOM and Eindhoven University of Technology, Eindhoven, The Netherlands, 7/9.

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ANNOUNCEMENTS

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: . ., ., .

2007 U.S. WORLD STANDARDS DAY PAPER COMPETITION
The U.S. standards community will celebrate World Standards Day on Thursday, October 18, 2007, at the Ronald Reagan Building and International Trade Center in Washington, DC. This year’s theme, “Standards and the Global Village” recognizes the global consensus-building capacity of standards developing organizations. Along with this event, the 2007 World Standards Day Sponsors, including NIST, will hold the annual paper competition. Papers are invited that show, using specific examples, ways that standards developing organizations have encouraged and created global consensus for the economic and social benefit of the global village. Paper competition winners will be announced and given their awards at the U.S. celebration of World Standards Day. Cash prizes are awarded by the Standards Engineering Society (SES) and the World Standards Day Planning Committee. The first place winner will receive a plaque and $2,500. Second and third place winners will receive $1,000 and $500, respectively, along with a certificate. In addition, the winning papers will be published in SES’s journal, Standards Engineering. ELIGIBILITY: The competition is open to all U.S. individuals in the private sector or at government facilities. Papers may be co-authored. RULES: Entries must be original and not previously published. NIST papers must be processed through WERB or BERB. All paper contest submissions must be received with an official entry form by midnight August 31, 2007, by the SES Executive Director, 13340 SW 96th Avenue, Miami, Florida, 33176. Complete details and entry forms are available on the SES website www.ses-standards.org (follow the link for “2007 WSD Paper Competition.”) For additional information about the U.S. Celebration of World Standards Day, or to register for the event, please visit www.wsd-us.org.
NIST Contact: Mary Donaldson, 301-975-6197, mary.donaldson@nist.gov

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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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