Technical Activities

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"Technical Activities 2004" - Table of Contents

Physics Laboratory home page
Office of Electronic Commerce
in Scientific and Engineering Data
The strategy for meeting this goal is to publish Physics Laboratory information on the World Wide Web, to develop web-accessible databases of physical reference data, and to evolve protocols to ensure interoperability in the exchange of scientific and engineering data.
GOAL: To coordinate
and facilitate the
electronic dissemina-
tion of  information
via the internet.

Dissemination of Information

INTENDED OUTCOME AND BACKGROUND

The Office of Electronic Commerce in Scientific and Engineering Data (ECSED) is responsible for the Physics Laboratory (PL) World Wide Web pages, at http://physics.nist.gov. We produce material for Web publication, encourage and support the production of material by others, and ensure the high quality of disseminated information. We are also engaged with PL Divisions and the NIST Standard Reference Data Program in developing physical reference databases for Web dissemination. We design and develop effective Web database interfaces to facilitate access to the data, providing data in multiple formats suitable for customer needs.

Since June 1994, we have provided a wide array of information ranging from physical reference data, technical activities, research and calibration facilities, technical contacts, publication lists, general interest, and news items. For the most recent six months, there was an average of 1½ million requests for web pages per month from the Gaithersburg server (nearly half from about 30 online databases containing physical reference data). A complete list of our databases is available at http://physics.nist.gov/data.

Recent work includes the development of new (1-5) and updated (6-11) Web databases:

  1. Handbook of Basic Atomic Spectroscopic Data
  2. Energy Levels of Hydrogen and Deuterium
  3. Spectral Data for the Chandra X-Ray Observatory
  4. X-Ray Transition Energies
  5. Potential Energy Surface Database of Group II Dimer Molecules
  6. Fundamental Physical Constants
  7. Searchable Bibliography on the Constants
  8. NIST Atomic Spectra Database
  9. Electron-Impact Cross Sections for Ionization and Excitation Database
  10. X-Ray Form Factor, Attenuation, and Scattering Tables
  11. Frequencies for Interstellar Molecular Microwave Transitions

Accomplishments

  • Units Markup Language

    We have continued to develop an XML (eXtensible Markup Language) schema for encoding scientific measurement units. Adoption of this schema will allow the unambiguous exchange of numerical data over the Internet. We have established collaborations with Lawrence Berkeley National Laboratory, Mathsoft, an engineering software company, and SEMATECH, a consortium of the semiconductor industry.

    To complement the UnitsML schema, we are in the process of developing an XML repository containing detailed information on both SI and non-SI scientific units. We anticipate this repository will be used by our customers to download industry-specific dictionaries of scientific units. Development of the UnitsML schema, repository, and a general ontology for scientific units is supported in part by the NIST Systems Integration for Manufacturing Applications (SIMA) program.

    CONTACT: Dr. Robert Dragoset
    (301) 975-3718
    robert.dragoset@nist.gov


  • Support for ITL on the DLMF

    We are providing support to the Mathematical and Computational Sciences Division of the NIST Information Technology Laboratory (ITL) to develop the Digital Library of Mathematical Functions (DLMF). Abramowitz and Stegun's Handbook of Mathematical Functions (with Formulas, Graphs, and Mathematical Tables) was first published by the National Bureau of Standards in 1964. It remains a technical bestseller and is among the most widely cited of all math reference compendia. But the Handbook is increasingly out-of-date, especially its numerical tables which account for over half its length. It also lacks the many recent developments in the theory and computation of functions that find essential use in physics and other sciences. A project is underway to develop a replacement, which should become a major resource of math reference data for special functions and their applications. The new DLMF will appear in a hardcover edition and as a free electronic publication on the Web.

    The Office of ECSED has a strong capability in LaTeX, a powerful, complex typesetting language particularly useful for representing mathematical expressions. Since the DLMF is being prepared in LaTeX, we are providing support to ITL on the preparation of this publication. This entails editing existing chapters with extensive handwritten corrections, in addition to adding new sections from handwritten text. We began working on the DLMF in August 2003 (providing up to 40 % of one staff person per year) and have thus far worked on 23 of the 40 chapters. The hardcover edition will be over 1000 pages in length and is scheduled to be printed in 2005.

    CONTACT: Mrs. Gloria Wiersma
    (301) 975-5547
    gloria.wiersma@nist.gov


  • New Capabilities for On-Line Databases

    Figure 1

    Figure 1. Karen Olsen and Gloria Wiersma discuss the design of an online database.

    The Electron-Impact Cross Sections for Ionization and Excitation Database has been available on the Web since August 1997. We recently collaborated with the Atomic Physics Division to update the database and release Version 3.0. Additions to the database include: excitation cross sections for atoms H, He, and Li; and ionization cross sections for atoms B, C, N, O, Al, Ga, and In, and for molecules C2H3, C3H3, C3H4 (allene and propyne), C3H5, C3H6, C4H2, C4H4, C4H6, C4H8 (1-butene, trans-2-butene, and isobutene), C6H2, C6H6 (fulvene), SiF4, HO2, and six chlorofluorocarbons (CClF3, CCl2F2, CCl3F, CHClF2, CHCl2F, CH2ClF). The user interface has been significantly enhanced, and, to accommodate the extensive additions of data, atomic and molecular data are now accessible through separate interfaces.

    With the addition of cross section data for atoms and the molecules, we are reaching a much wider customer base. The database will benefit those working in the areas of fusion plasma modeling, plasma processing of materials, modeling of semiconductor fabrication, and modeling of combustion chemistry useful to the automotive industry. The Electron-Impact Cross Sections for Ionization and Excitation Database can be accessed on the Web at http://physics.nist.gov/ionxsec.

    Figure 1
    This updated database was developed using two popular Web development tools: MySQL and PHP. MySQL is a relational database management system. PHP, a widely used general-purpose scripting language, provides interfaces to many different database systems and has built-in libraries for many common Web tasks. Both PHP and MySQL have the strengths of high performance, low cost, ease of use, efficiency and portability; and they are Open Source solutions.

    Using MySQL and PHP, we have created a Web-based data entry form so that scientists can now add data to the database. The data retrieval interface (a periodic table and various selection forms) is dynamically generated based on the current contents of the MySQL database. Thus, when data is entered into the MySQL database, it is immediately viewable.

    CONTACT: Mrs. Karen Olsen
    (301) 975-3286
    karen.olsen@nist.gov

"Technical Activities 2004" - Table of Contents