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Displaying 18626 - 18650 of 53281

Ontology Formalisms: What is Appropriate for Different Applications?

October 6, 2009
Author(s)
Craig I. Schlenoff
Ontologies can take many forms. There are ontologies that are extremely formal (e.g., using first order logic), and there are ontologies that are much less formally defined (e.g., ontologies in the relational databases or dictionaries). Nonetheless, all of

Open Issues in Secure DNS Deployment

October 6, 2009
Author(s)
Ramaswamy Chandramouli, Scott W. Rose
This paper describes some practical administrative issues and challenges in the deployment of DNSSEC - an IETF specified suite of security measures for securing the Domain Name System (DNS). The issues covered include: (a) Choice of Cryptographic

A Combined Fit of Total Scattering and Extended X-ray Absorption Fine Structure Data for Local-Structure Determination in Crystalline Materials

October 5, 2009
Author(s)
Igor Levin, Victor L. Krayzman, Joseph C. Woicik, Terrell A. Vanderah, M. G. Tucker, Thomas Proffen
Reverse Monte Carlo (RMC) refinements of local structure using a simultaneous fit of x-ray/neutron total scattering and EXAFS data were developed to incorporate an explicit treatment of both single- and multiple-scattering contributions to EXAFS. The

Advanced Capacitance Metrology for Nanoelectronic Device Characterization

October 5, 2009
Author(s)
Curt A. Richter, Joseph J. Kopanski, Yicheng Wang, Muhammad Y. Afridi, Xiaoxiao Zhu, D. E. Ioannou, Qiliang Li, Chong Jiang
We designed and fabricated a test chip (consisting of an array of metal-oxide-semiconductor (MOS) capacitors and metal-insulator-metal (MIM) capacitors ranging from 0.3 fF to 1.2 pF) for use in evaluating the performance of new measurement approaches for

An experiment for the precision measurement of the radiative decay mode of the neutron

October 5, 2009
Author(s)
R Cooper, Christopher D. Bass, E Beise, H Breuer, Jim Byrne, T E. Chupp, Kevin J. Coakley, Maynard S. Dewey, B Fisher, Changbo Fu, Thomas R. Gentile, M. McGonagle, Hans P. Mumm, Jeffrey S. Nico, Alan K. Thompson, F E. Wietfeldt
The neutron typically beta decays into a proton, electron, and antineutrino. In some decays, it can be accompanied by a high energy photon. We recently performed the rst observation of the radiative beta decay branch for the free neutron with photons of

Prospects for a New Cold Neutron Beam Measurement of the Neutron Lifetime

October 5, 2009
Author(s)
Maynard S. Dewey, Kevin J. Coakley, David M. Gilliam, G. Greene, A. Laptev, Jeffrey S. Nico, William M. Snow, F. E. Wiefeldt, A. Yue
In the most accurate cold neutron beam determination of the neutron lifetime based on the absolute counting of decay protons, the largest uncertainty was attributed to the absolute determination of the capture flux of the cold neutron beam. Currently an

Prototype Cantilevers for AFM Nanomechanical Property Measurement

October 2, 2009
Author(s)
Richard S. Gates, Mark Reitsma
Atomic Force Microscopy (AFM) is a widely used technique for imaging surfaces and measuring properties at the micro and nano-scales; however, the accuracy and precision of these measurements is hampered by the lack of suitable traceable standards and

A Discussion on the Interpretation and Characterization of Metafilms/Metasurfaces: The Two-Dimensional Equivalent of Metamaterials

October 1, 2009
Author(s)
Christopher L. Holloway, Andrew M. Dienstfrey, Edward E. Kuester, John F. O'Hara, Abul K. Azad
A metafilm is the surface equivalent of a metamaterial. More precisely, a metafilm is a surface distribution of suitably chosen electrically small scatterers. Metafilms are becoming popular as an alternative to the full three-dimensional metamaterials

A Service Oriented Framework for Construction Supply Chain Integration

October 1, 2009
Author(s)
Jack Cheng, Kincho H. Law, Albert W. Jones, Ram D. Sriram
Supply chain management integrates key business processes and facilities, involving end users and suppliers that provide products, services and information. Supply chain integration can potentially add value to the stakeholders along product development

Accumulation of Large Protein Fragments in Prematurely Senescent ARPE-19 Cells

October 1, 2009
Author(s)
Illarion V. Turko, Wei-Li Liao
Senescence of retinal pigment epithelial (RPE) cells is a crucial event in the pathogenesis of age-related macular degeneration (AMD). This study was design to improve the understanding of changes that underlie the RPE senescence. The levels of various

Apparent Equilibrium Constants for Enzyme-catalyzed Reactions

October 1, 2009
Author(s)
Robert N. Goldberg
This table contains values of apparent equilibrium constants K for selected enzyme-catalyzed reactions at specified temperatures T and pHs. In those cases where the ionic strength I and/or the pMg (pMg = log10[Mg2+]) have been reported, the values of

Climbing Mount Probable: Mutation as a Cause of Nonrandomness in Evolution

October 1, 2009
Author(s)
Arlin B. Stoltzfus
Genomes differ systematically in Guanine-plus-Cytosine (GC) content. GC-rich genomes encode proteins enriched in amino acids with GC-rich codons, such as Glycine (with codons GGT, GGC, GGA, GGG), while AT-rich genomes are enriched in amino acids with AT

Development of an infrared optical scattering instrument from 1 um to 5 um

October 1, 2009
Author(s)
Jinan Zeng, Leonard M. Hanssen
The wavelength coverage of the IR optical scattering instrument developed at the National Institute of Standards and Technology has been extended to cover the continuous range from 1 um to 5 um. Besides the previously available diode lasers at wavelengths

Dietary Supplement Standard Reference Materials

October 1, 2009
Author(s)
Lane C. Sander, Karen W. Phinney, Michele M. Schantz, Katherine E. Sharpless, Stephen A. Wise
In 1994, the U.S. Congress enacted the Dietary Supplement Health and Education Act to "protect the right of access of consumers to safe dietary supplements". In response to this legislation, the National Institute of Standards and Technology (NIST), the
Displaying 18626 - 18650 of 53281