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Thermodynamics

Overview

Thermodynamics research at NIST helps our industrial and scientific partners develop more efficient and reliable processes by improving our understanding of how the arrangement of matter and energy impact the properties of physical and chemical systems.

Thermodynamic Data Included in Phase-Based Data Repository

MGI diagram

An essential part of the MGI is the development of phase-based data repository. Phase-based data are important for many applications, including the development of CALPHAD-based multicomponent databases. The phase-based data include zero-dimensional, one-dimensional, two-dimensional, and three-dimensional data. Examples of some of the phase-data included are phase transformation temperatures (e.g. melting, solidus, solvus), lattice parameters, thermal expansion, elastic constants, and diffusion coefficients and compositions profiles. These data are reported as functions of composition, temperature and/or pressure.

This repository consists of three data sources:

  • Curated experimental and computational multicomponent alloy data in support of the development Co-based superalloys. Currently the data are focus on diffusion data and transition temperatures. These data are curated using the NIST Materials Data Curation System. This collection is being developed in conjunction with CHiMaD.
  • Thermodynamic Research Center Data provides access to thermophysical property data with a focus on unary, binary, and ternary metal systems through a free online web application and associated API. All data are from original experimental publications and include full provenance and critically evaluated uncertainty.
  • Self diffusion and impurity diffusion coefficient data (experimental and computational) are searchable via the periodic table.

News and Updates

Projects and Programs

Reliable Vaccine Storage

We study provider-level vaccine storage and temperature monitoring methods to develop best practice guidance for public health audiences.

Gas properties for flow metering

Flow meters that rely on measuring the pressure drop across a laminar flow element can be accurately calibrated using a benign surrogate gas (such as helium or

Publications

New International Formulation for the Viscosity of Heavy Water

Author(s)
Marc J. Assael, S.A. Monogenidou, Marcia L. Huber, Richard Perkins, Jan V. Sengers
The International Association for the Properties of Water and Steam (IAPWS) has recently adopted a new formulation for the thermodynamic properties of heavy

Thermal Conductivity of Liquids

Author(s)
Marcia L. Huber
This is an update to the chapter on liquid thermal conductivity in the CRC Handbook of Chemistry and Physics, 102nd Ed.

Tools and Instruments

Leak Artifacts

Leak artifacts are calibrated in the range 1 x 10-6 to 1 x 10-13 mol/s (2 x 10-2 to 2 x 10-9 std. cm3/s at 0 °C). The calibration can be performed directly

Piston gauges and pressure transducers

Piston gauges are used to calibrate customer piston gauges and pressure sensing devices. Piston gauges are calibrated via a direct comparison to another piston

Low Pressure Gauges

NIST has developed best-in-the-world primary standard pressure measurement capabilities for pressures spanning the range of 0.01 Pa to 360 kPa through the

Awards