U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Physics

Thermodynamics

Projects/Programs

Displaying 1 - 25 of 35
acoustic resonator

Acoustic Techniques in Fluid Metrology

Ongoing
We use acoustic techniques in gases to measure the thermodynamic temperature of a gas in a spherical or cylindrical cavity, the optical absorption in gases and aerosols (in collaboration with NIST’s Chemical Sciences Division) the quantity of gas in a large vessel or tank, and gas flow into/from a
Acoustic Thermometer

Acoustic Thermometry

Completed
Data from the NIST acoustic thermometer will form an improved basis for the equations used with platinum resistance thermometry, which is the primary mechanism to disseminate accurate temperature standards. Objective: To obtain measurements of thermodynamic temperature in the range between 273 K and
cold atom thermometer (CAT) experiment

Atomic Thermometers

Ongoing
Approach 1 Compact Blackbody Radiation Atomic Sensor (CoBRAS) The Compact Blackbody Radiation Atomic Sensor (CoBRAS) uses a thermal vapor of atoms excited by a single laser to detect BBR. From the optically excited state, atomic population is transferred to other, nearby excited states by a
Cover of the ASME International Steam Tables for Industrial Use, Third Edition

Contributions to International Standards on the Properties of Water

Ongoing
Water is probably the most widely used industrial fluid and it is important to have internationally accepted standards for its properties. This information is crucial to the analysis and design of thermal power cycles, as well as for climate studies including the hydrosphere. (Here is a summary of
blue crystal

Crystallographic Databases

Ongoing
Impact and Customers Materials with new or improved properties are continually being developed to meet demands for increased functionality of components and devices at decreased costs. Examples of multi-million dollar industries driven by materials advances are solid-state lighting (GaN-based
Illustration of Doppler thermometry

Deployable Doppler Thermometry

Ongoing
Accurate temperature measurements are essential to many industrial processes, including petrochemical or pharmaceutical production and nuclear power generation. Typical process control thermometers, such as resistance temperature detectors, are known to drift over time and degrade when subject to
prototype system

Fixed Point Development: Non-Metals

Ongoing
A fixed point is a reproducible reference temperature, usually either melting of freezing of a pure substance, that allows a standardized interpolation scheme for the purposes of temperature scale dissemination. Most SPRTs are long-stem designs that require immersion-type fixed points incorporating
SLowFlowS diagrams

Flow Metering and Properties for Semiconductor Process Gases

Ongoing
A type of flow meter called a mass flow controller (MFC) is used to regulate gas flow in order to produce the desired structures during chip fabrication. As semiconductor manufacturing advances, the requirements on MFC performance are increasingly strict: any process variation can reduce device
two-capillary viscometer

Gas properties for flow metering

Ongoing
NIST has two on-line databases that include accurate gas viscosity values: SEMIPROP - NIST Standard Reference Database 134 - for selected semiconductor process gases NIST Chemistry WebBook - for heat transfer fluids, components of air, components of natural gas [Note: as of February 2014, the NIST
pedslashfullres

Inorganic Phase Equilibrium Data

Ongoing
Every deliberate effort to develop a new material or to improve processing begins with chemical composition and the conditions (temperature, pressure) under which pure compounds and their mixtures are stable ( an equilibrium phase diagram ). In the absence of such information, materials scientists
MLF_EquationofState1

Machine Learning Fluid Equations of State

Ongoing
Understanding the thermodynamic properties of fluids and fluid mixtures is of central importance in many fields of science and engineering ranging from medicine to consumer products. The nature of the particles in a fluid can vary greatly depending on the type of interactions present, e.g., dipole
Multi_Colloidal_Crystals2

Machine Learning to Predict Multicomponent Colloidal Crystals

Ongoing
There is a direct link between a material’s macroscopic properties and its microscopic structure, which makes rational bottom-up self-assembly a powerful tool for engineering properties of materials. In general, colloids are facile material building blocks whose shape, charge, and surface

Nanoscale Thermal Properties

Completed
It is known that at the nanoscale, composition and interface structure play important roles in determining the mechanical, thermal, and electrical properties of multiphase nanomaterials and nanocomposites. To probe the thermal properties of these heterogeneous nanomaterials, local thermal analysis

The NIST Chemistry Webbook

Ongoing
Intended Impact It is part of NIST's mission to distribute Standard Reference Data to scientists, engineers, educators, and the general public. The NIST Chemistry WebBook is intended to help fulfill NIST's mission by distributing such data over the Internet. Objective Develop a web site
Evolution of Flat-histogram Monte Carlo Simulation

NIST Standard Reference Simulation Website

Ongoing
Molecular simulations, in particular Monte Carlo Molecular Simulation and Molecular Dynamics Simulation, are methods for computing the properties of some kind of system, for which the intermolecular interactions are specified via mathematical relationships derived from statistical mechanics. Since
Optical microscope image of a silicon nitride trampoline pressure sensor

Optomechanical Pressure Sensing

Ongoing
Measurement and control of high-vacuum pressure is important for many industrial processes, particularly semiconductor fabrication. Typical process pressure monitors are known to lose accuracy over time and so require repetitive calibration. Pressure transfer standards that support high-vacuum and
photonic calorimeter/dosimeter

Photonic Dosimetry

Ongoing
With this effort, NIST is responding to industry needs for traceable, measurement solutions that can resolve spatial variations of absorbed dose at the level of individual components on a silicon wafer or bacteria on surgical instruments. Presently, there is only limited traceability to national
SPoT chip

Photonic Thermometry

Ongoing
Why do we need reliable temperature metrology? Temperature, the second most measured physical property after time and frequency, is indispensable to innumerable industries, military services, medicine, climate, and weather forecasts – precise, accurate, and rapid temperature metrology enables much
Platform for Realizing Integrated Molecule Experiments

Platform for Realizing Integrated Molecule Experiments (PRIME)

Ongoing
Blackbodies realize a clear relationship between radiated power and temperature through Planck’s law. While a reliable instrument for temperature and power calibrations, blackbodies are afflicted with a plethora of systematics (e.g., non-ideal emissivity, propagation loss, temperature gradients
A collage of REFPROP screens

Reference Fluid Thermodynamic and Transport Properties Database (REFPROP)

Ongoing
REFPROP is a computer program, distributed through the Standard Reference Data program of NIST, that provides thermophysical properties of pure fluids and mixtures over a wide range of fluid conditions including liquid, gas, and supercritical phases. It contains critically evaluated mathematical
Color coded refrigerant bottles

Refrigerants and Working Fluids

Ongoing
We apply a wide range of experimental apparatus to the task of measuring the properties of working fluids. Many of these instruments are the same as those used in our work on standard reference fluids, and our data for working fluids approach the accuracy of the reference fluids. Thermodynamic
Alex Rodriguez with data logger

Reliable Vaccine Storage

Completed
Our group examines best practices for the storage and monitoring of vaccines in partnership with the Centers for Disease Control and Prevention’s (CDC) Vaccine Supply and Assurance Branch. Vaccines are highly temperature sensitive, and inappropriate storage conditions can render them ineffective

Renewable Energy and Fuels

Ongoing
Fuel volatility and chemical characterization. We specialize in the Advanced Distillation Curve (ADC) method, developed at NIST, which is a powerful tool for the measurement of distillation curves to characterize complex fluids. We have applied this to simple hydrocarbons, gasolines, diesel fuels