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Industry is demanding reliable and accessible reference data on the physical and chemical properties of a wide variety of compounds at an increasing rate. These data are required in the development of models for process design, energy efficiency, and in the evaluation of possible environmental impacts. Basic reference data are also critical to the transportation and storage of fluids and in custody transfer.
The development of databases for use in industry and academia is a fundamental task of all the focus areas within the Division. Thus, many of the Technical Reports pertain both to Basic Reference Data and to a specific technical focus area. The notable exception to this is the NIST Chemical WebBook, which is a data dissemination tool that is designed ultimately to provide a link for most of our data activities (see Technical Report 1). Various data activities of the Division are discussed in Technical Reports 2, 5, 12, 15-18, 21-23, and 26. The strong integration of data activities with the experimental and computational programs means that experimental efforts often arise out of needs that these data activities identify. A recent example of this is the experimental and computational efforts that arose out of the project to create a focused database for chlorination chemistry (See Technical Report 11).
Technical Reports
The continued increase in computing power along with robust quantum mechanical codes is making the ab initio calculation of chemical properties an important tool for the industrial chemist. Progress in this area, however, is hampered by the lack of standards, comparisons, and simplified methodologies. In addition to this external need, the experimental projects within the Division benefit greatly by having a strong computational component. These considerations lead us to establish a computational chemistry focus area in the Division. Thus, we have initiated projects to compile, evaluate, and disseminate information about computational techniques (See Technical Report 2) and to develop improved methodologies for calculating thermodynamic and kinetics parameters (See Technical Reports 3, 4, and 20).
Technical Reports
Future plans include an extension into condensed phase chemistry, which will utilize the Division's capabilities in molecular dynamics (see Technical Report 29) and will be coupled with experimental efforts in solution-phase and supercritical-water kinetics (See Technical Report 6).
Technical Reports
At some point in the manufacture of almost all the products that we use, there is a chemical transformation or separation process involved. In modern industry, the products and processes are designed and optimized by process simulators. These rely on fundamental physical and chemical property data. The Division's goal is to provide the data that industry needs to effectively apply process modeling and simulation at all appropriate points in the manufacturing cycle, from the separation and treatment of raw feedstock, through the manufacturing process, to the ultimate treatment and disposal of waste streams. This has led to a wide array of projects in the Division, some of which are strongly focused on a specific problem. Areas of current interest include:
Technical Reports
In addition to providing the basic physical and chemical property data needed for process simulation, the Division is also active in the development and application of simulation techniques applied to both reacting chemical systems (See Technical Reports 12 and 13) and complex fluid systems (See Technical Reports 27 and 28).
Technical Reports
Energy-related fluids include both those which are primary sources of energy, the fuels, and those which interconvert heat and useful work - the working fluids. In several key areas, industry requires accurate and comprehensive equilibrium and transport property data and models for these fluids. These areas include the design and optimization of working cycles in refrigeration and power production systems; the design and control of gas processes; custody transfer; and in the development of new, cleaner energy systems. Efforts in the Division to meet these needs include the development of experimental apparatus for thermophysical property measurements; the acquisition of data; and the development and dissemination of accurate correlations. Other work has focused on the thermophysical and transport properties of mixtures of alternative refrigerants with lubricants. An important facet of this focus area has been participation in the development of internationally accepted standards. Examples of activities under study in this focus area include:
Technical Reports
The use of chemicals in American industry is ubiquitous, and much of the Division's efforts go toward improving these processes. The fate and disposal of these industrial chemicals and the associated byproducts are also of great concern. A wide variety of physical and chemical data is essential to understand the fate and impact of industrial chemicals in the environment, to develop strategies for the removal or destruction of harmful byproducts, or to design processes and products which minimize environmental impact. One of the considerations for choosing new data sets for inclusion into the NIST WebBook is environmental importance. Thus, in the past year Henry's law constants were added along with many new vapor pressure values (see Technical Report 1). We have carried out studies on the atmospheric chemistry of industrial compounds for many years, spanning studies of reactive species which may contribute to photochemical smog, to much less reactive species which may contribute to ozone depletion or global warming. Providing fundamental data in support of chemical disposal technologies is a relatively new activity, although it was a driving factor behind the development of a supercritical water reactor (See Technical Report 6). Technical Report 19 discusses recent results from a collaborative effort in the application of our expertise in radiation chemistry to a serious waste disposal problem. Other work in the Division includes studies of the phase equilibria, coexisting densities, and interfacial tensions of mixed electrolyte/solvent waste streams.
During FY99, we initiated a new project to leverage our experimental capabilities in atmospheric chemistry by use of new capabilities in computational chemistry. This was prompted by studies that demonstrated the shortcomings of simple structure-activity relationships. The long-term objective of this project is to establish a theoretically justified means of predicting the atmospheric reactivity of new classes of compounds with the use of a limited number of selected experimental studies for verification. Progress in this area is summarized in Technical Report 20.
Technical Reports
Central to all of chemistry is the analysis of complex mixtures and the identification of the individual chemical constituents. These analyses are usually derived from basic physical/chemical properties of the species, and knowledge of these properties is thus critical to the reliability of the information. The Division strives to produce evaluated data, predictive algorithms, and analysis software to assist in the identification and quantification of a range of species under diverse conditions. The NIST WebBook plays a central role in this, but current Division activities also include measurements and data acquisition designed to expand the gas chromatographic and mass spectrometric databases (see Technical Reports 21 and 22). A critically important activity in the Division is the development of complex algorithms for the rapid and automatic analysis and deconvolution of GC/MS data for the identification of chemical-weapon agents (See Technical Report 23).
Technical Reports
In support of the Division mission to provide U.S. industry with thermophysical properties of gases, liquids, and solids, the Division maintains a focus area on the fundamental studies of fluids, with strong experimental and theoretical components. The goals are to develop and utilize unique experimental, theoretical, and simulation capabilities to study fluid systems under equilibrium and nonequilibrium conditions. Much of the work relates to phase boundaries, vapor-liquid and solid-fluid equilibria, including complex interactions leading to gel formation. Some of the areas the Division is focusing on are:
Technical Reports
In selected cases, the measurements and the calculations of the thermophysical properties of gases have been refined to make fundamental contributions to metrology. We have used very accurate measurements of the speed of sound in argon between 200 K and 300 K to determine the differences between the internationally accepted temperature scale (ITS-90) and the Kelvin thermodynamic temperature. This work is being extended to 800 K in collaboration with the Temperature Group of Division 836 (see Technical Report 30). Our ab initio calculations of the thermal conductivity, viscosity, and second virial coefficient of helium are now more accurate than the measurements of these properties. Thus, calculated "data" can be used to calibrate instruments made to measure these properties. With a newly funded competence program, we are improving the measurement and the ab initio calculation of the dielectric constant of helium. Our goal is to use gas-filled capacitors to calibrate piston gauges in the range 0.5 MPa to 5 MPa.
Technical Reports
Cryogenic technologies are critical to a wide variety of technically and industrially important areas. These include the cooling of electronics for optical sensing and high-speed computing; the production of ultra-clean vacuum environments for semiconductor and other manufacturing processes; the liquefaction of natural gas and other industrial gases on demand; and in numerous medical applications. The research of the Division in this area involves the application of thermophysical concepts and measurements for temperatures below 120 K. This research has focused primarily on improved measurement and modeling techniques involved in the development and characterization of novel and improved cryocoolers (See Technical Report 31), studies of microscale heat transfer, and the maintenance and improvement of the national standard for cryogenic flow measurements (See Technical Report 32). As part of an upgrade, the cryogenic flow loop has been brought into compliance with ISO Guide 25 requirements.
Technical Reports
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Last modified: 29 February 2000
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