Physical and Chemical Properties Division

SUMMARY

The activities of the Physical and Chemical Properties (PCP) division are central to existing and emerging national priorities, and some U.S. industrial and academic establishments rely heavily on PCP’s efforts. There is an apparent lack of mechanisms for effective internal dissemination of results and for communicating between groups, projects, and divisions. It would be desirable, for example, to have weekly seminars attended by all division staff. PCP is productive and has considerable impact, as indicated by the number of users who access the products it makes available on the Web or who license the software; it would be useful to document that productivity and impact in a more systematic manner. PCP and CSTL as a whole should develop a strategic plan for managed growth, including recruitment, and identify areas of opportunity and areas for concern.

ADDRESSING NATIONAL PRIORITIES

The measurement of chemical and thermophysical properties; the systematic archival, assessment, and dissemination of relevant experimental data; and the establishment of standards are all aligned with the mission of NIST. These activities are central to some existing and emerging national priorities, and PCP excels at them.

The division consists of eight groups, three located at Gaithersburg and five at Boulder. The activities and products of each group are listed in Table 1.

IMPACT, INNOVATION, AND TECHNICAL MERIT

The Chemical Reference Data group is developing standard chemical identifiers (InChI) and data for molecular identification, both of which support the NIST mission. The Chemistry WebBook maintained by this group disseminates results to the public. The WebBook is accessed by thousands of researchers (25,000,000 hits to date) and is a valuable national resource that could be made even more valuable by being integrated with the products of other groups in the PCP and other NIST divisions. A means of retrieving data for a list of compounds rather than just one at a time would be very useful. The Mass Spectrometry Data Center is impressive, and the group is pursuing new directions in peptide and protein mass spectra. This product is widely licensed by instrument manufacturers to include in their data analysis software.

The Computational Chemistry group’s activities are essential for validating data sets and for calculating properties that are difficult to measure. Computational chemistry is an important activity, and the theory group nicely complements the experimental activities of several projects, including that on real fuels. Efforts to quantify the accuracy of theoretical predictions are important, as is the reporting of this information. The new direction, aimed at using theory to improve peptide identification by mass spectrometry, is a positive one. Theoretical work in nanotechnology is timely and will become particularly relevant as NIST’s efforts in nanotechnology continue to grow. It would be



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An Assessment of the National Institute of Standards and Technology Chemical Science and Technology Laboratory: Fiscal Year 2007 Physical and Chemical Properties Division SUMMARY The activities of the Physical and Chemical Properties (PCP) division are central to existing and emerging national priorities, and some U.S. industrial and academic establishments rely heavily on PCP’s efforts. There is an apparent lack of mechanisms for effective internal dissemination of results and for communicating between groups, projects, and divisions. It would be desirable, for example, to have weekly seminars attended by all division staff. PCP is productive and has considerable impact, as indicated by the number of users who access the products it makes available on the Web or who license the software; it would be useful to document that productivity and impact in a more systematic manner. PCP and CSTL as a whole should develop a strategic plan for managed growth, including recruitment, and identify areas of opportunity and areas for concern. ADDRESSING NATIONAL PRIORITIES The measurement of chemical and thermophysical properties; the systematic archival, assessment, and dissemination of relevant experimental data; and the establishment of standards are all aligned with the mission of NIST. These activities are central to some existing and emerging national priorities, and PCP excels at them. The division consists of eight groups, three located at Gaithersburg and five at Boulder. The activities and products of each group are listed in Table 1. IMPACT, INNOVATION, AND TECHNICAL MERIT The Chemical Reference Data group is developing standard chemical identifiers (InChI) and data for molecular identification, both of which support the NIST mission. The Chemistry WebBook maintained by this group disseminates results to the public. The WebBook is accessed by thousands of researchers (25,000,000 hits to date) and is a valuable national resource that could be made even more valuable by being integrated with the products of other groups in the PCP and other NIST divisions. A means of retrieving data for a list of compounds rather than just one at a time would be very useful. The Mass Spectrometry Data Center is impressive, and the group is pursuing new directions in peptide and protein mass spectra. This product is widely licensed by instrument manufacturers to include in their data analysis software. The Computational Chemistry group’s activities are essential for validating data sets and for calculating properties that are difficult to measure. Computational chemistry is an important activity, and the theory group nicely complements the experimental activities of several projects, including that on real fuels. Efforts to quantify the accuracy of theoretical predictions are important, as is the reporting of this information. The new direction, aimed at using theory to improve peptide identification by mass spectrometry, is a positive one. Theoretical work in nanotechnology is timely and will become particularly relevant as NIST’s efforts in nanotechnology continue to grow. It would be

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An Assessment of the National Institute of Standards and Technology Chemical Science and Technology Laboratory: Fiscal Year 2007 TABLE 1 Summary of the Activities and Products of Each Group in the PCP Division Group Activities Products Chemical Reference Data (Gaithersburg) WebBook database; mass spectrometry and chromatography data; International Chemistry Identifier (InChI). Chemistry WebBook; Mass Spectrometry Data Center; InChI. Computational Chemistry (Gaithersburg) Computational methods validation and development; peptide mass spectrometry predictions; electron transport; nanoparticle properties. Computational chemistry comparison and benchmark database. Real Fuels Project (Gaithersburg) Measure and evaluate reaction rate data for combustion and atmospheric models; global warming potentials. Gas-phase kinetics database; atmospheric kinetics; ChemRate. Thermodynamics Research Center (TRC) (Boulder) Information system development for thermophysical properties; evaluate and estimate properties. ThermoML (IUPAC); ThermoData engine; TRC tables; FloppyBook databases. Properties for Process Separations (Boulder) Advanced distillation curves; fuel decomposition kinetics; properties of explosives; trace components in fuel gas; chemical analysis. Gas chromatography data (in WebBook). Experimental Properties of Fluids (Boulder) Measurement of thermodynamic and transport properties. Included in RefProp, others. Theory and Modeling of Fluids (Boulder) Develop high-accuracy models for fluid properties; property evaluation and estimation. RefProp; SUPERTRAPP; others. Cryogenic Technologies (Boulder) Refrigeration process models; cryogenic measurement techniques; pulse tube cryocooler; properties and process data. Cryogenic material properties database; cryogenic flow calibration/tests. desirable, however, to develop new initiatives in many-molecule calculations and force-field development, which would facilitate closer ties to the experimental efforts in fluid property characterization. The division should also pursue its own efforts in methods development, thereby ensuring its access to state-of-the-art theoretical chemistry methods. The Industrial Fluid Properties Simulation Challenge in its current form is imperfect; some restructuring is needed to turn it into a more relevant and constructive endeavor. The Real Fuels Project group represents an important activity that is highly relevant to our nation’s energy policies. Activities in atmospheric kinetics are also important for environmental considerations. An authoritative set of Global Warming Potential values for atmospheric species should provide useful guidance to climate control efforts. Making kinetic measurements at actual combustion temperatures is a worthy endeavor; the data are important and will be used. The Thermodynamics Research Center (TRC) group is essentially a data collection, analysis, and dissemination activity in which many undergraduate students are involved. A thermodynamic data evaluation project evaluates literature data, archives it,

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An Assessment of the National Institute of Standards and Technology Chemical Science and Technology Laboratory: Fiscal Year 2007 and makes it accessible to users for a fee. This appears to be an extremely useful and successful project. The division has worked hard to make data easily accessible. Charging for its use, however, is a barrier to dissemination. Dissemination to educational institutions should be free in order to maximize its value to the nation, and there appears to be a genuine desire within the division to do this. Commercial users should pay a fee that is commensurate with their user base. Overall this thermodynamic data evaluation project is an impressive activity. The Properties for Process Separations group interacts extensively with industry. Sometimes collaborations produce funding, depending on the arrangement. This group includes an effort aimed at measuring the properties of explosives, including vapor pressures, surface energies, and permeation. It has developed clever techniques to measure very low vapor pressures, an essential attribute for work on explosives detection, which is sponsored by the Transportation Security Administration (TSA). This work is highly relevant and important. NIST seems to be one of the few agencies measuring these properties. It should advertise this function or activity and generate more resources for this work, particularly from TSA and other intelligence/security agencies. It would be desirable, moreover, to interact with detection instrument makers. Additional communications and possibilities for synergistic collaboration (e.g., with other national metrology laboratories) in this area should be explored. The Properties for Process Separations group also measures distillation curves, which provides a wide variety of information for applications. The group has developed a new concept called the Advanced Distillation Curve (ADC). This is essentially a more controlled and elaborate way of measuring distillation curves that reduces variability and uncertainty. Advanced distillation curves include much more information, including the composition of each fraction that is being distilled. This activity, while useful, is quite mature and not really at the forefront of research. More innovation is necessary, and it would be desirable to extend collaboration with the Real Fuels Project. Experimental Properties of Fluids is a data acquisition group with considerable expertise in the measurement of thermodynamic and transport properties of pure components and mixtures (e.g., densimetry, phase equilibria, calorimetry, thermal conductivity, quartz-balance viscometry). Priorities for measurements are set by very reasonable criteria. Overall this is a solid group conducting state-of-the-art thermodynamic measurements. A new effort on biofuels centered around alcohol mixtures and biodiesel (esters from plants) is likely to produce useful results. The group’s comprehensive activity will include data measurement and modeling to feed information to customers. An enhanced knowledge base will permit better evaluation of alternatives, more prospects, and better economics. This could become a high-profile project. The group should explore and establish connections to the Department of Energy. The Theory and Modeling of Fluids group is relatively small. It includes multiple collaborations with overseas groups, including some in Germany, Japan, Greece, Great Britain, Argentina, and Mexico. Development of accurate equation-of-state (EOS) models for fluids, including refrigerants and significant components of combustion and synthesis gas streams, is important for technology advances in new refrigerants and novel energy systems. The RefProp computer program, which implements these models in an easily usable form, is an effective way to disseminate these results. EOS development or data measurement is declining in the United States and increasing overseas. The group

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An Assessment of the National Institute of Standards and Technology Chemical Science and Technology Laboratory: Fiscal Year 2007 expressed concern over a shortage in this country of individuals highly trained in data measurement and prediction. The emphasis of the group is on description-correlation of properties, as opposed to prediction. The modeling effort should be expanded and become comparable to the accompanying experimental program. True predictions are essential to gain insights, to design or engineer fluids with particular properties, and to provide properties for difficult systems (e.g., explosives, where the samples are allegedly very hard to get). The connection between the many-molecule theory efforts at the Gaithersburg facility and those at the Boulder facility should be strengthened. Activities in humid gases provided a noteworthy example of what can be done with true predictions and of how electronic structure efforts can be combined with statistical mechanics to address important experimental questions. PCP should consider expanding efforts along these lines. The Cryogenic Technologies group activities include measurement, model development, calibration of cryogenic flowmeters, and materials evaluation (materials testing is no longer pursued at NIST, but literature continues to be mined and evaluated by NIST). The group focuses on advanced refrigeration systems, mostly closed-cycle coolers (sponsored by a variety of agencies or customers, including the Navy, the Defense Advanced Research Projects Agency [DARPA], the Air Force, and Cryomagnetics, Inc.). This is a creative group and represents a national resource for work on cryogenics. The efforts are clearly technologically relevant, and this advanced group offers unique capabilities. Databases are part of the activities and products of several groups, including Chemical Reference Data, Computational Chemistry, the Real Fuels Project, Cryogenic Technologies, and the Thermodynamics Research Center. However, there is a need for a comprehensive plan for maintaining, improving, and disseminating critical, fundamental databases such as those for chemical kinetics and electron impact cross-section. The number of talks presented by the PCP division at scientific meetings in 2006 (78 presentations) declined significantly (by more than 30 percent) from what it had been in recent years. It was unclear whether this was a result of budgetary restrictions. It is extremely important for the division staff and postdoctoral fellows to publicize their work at meetings. There was an apparent lack of mechanisms for effective dissemination of results and for communication between groups, projects, and other CSTL divisions. It would be desirable, for example, to have weekly seminars that are attended by all division staff. This is particularly important since this division is split between two sites. PCP must continue to publish its members’ work aggressively. The number of publications in 2006 was consistent with that in previous years (an average of about 70). The number of publications is one of the key metrics by which engineers and scientists evaluate their performance, and it is important for PCP to maintain a high profile in the literature. It is also important for the division to examine the metrics that it uses to evaluate its progress.

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An Assessment of the National Institute of Standards and Technology Chemical Science and Technology Laboratory: Fiscal Year 2007 INFRASTRUCTURE The division has traditionally been a leader in the measurement, characterization, and prediction of thermophysical properties. The division has always had a well-deserved, outstanding reputation in academic and industrial circles. It must ensure that such a tradition of excellence is maintained, particularly as prominent senior researchers retire or leave NIST. Some in the division expressed concern that it is becoming increasingly difficult to recruit young scientists and engineers in the areas of interest to PCP. The division and the laboratory as a whole should develop a strategic plan for managed growth that would address recruitment issues and could identify areas of opportunity and areas of concern. The division has access to state-of-the-art instrumentation. Part of the division, particularly in Gaithersburg, expressed concern about the lack of physical space for staff and laboratories. The laboratory should address that concern and develop and discuss its plan for more effective space allocation. CONCLUSIONS PCP activities are central to existing and emerging national priorities. Some U.S. industrial and academic establishments rely heavily on the efforts of the division. There were, however, few apparent mechanisms for effective internal dissemination of results or for communication between groups, projects, and divisions. It would be desirable, for example, to have an internal weekly seminar series attended by all division staff. The division is productive and has considerable impact, as indicated by the number of users who access products that the division provides on the Internet or who purchase licenses for the software; it would be useful to document that productivity and impact in a more systematic manner. The division should develop a strategic plan for managed growth that would address recruitment issues and could identify areas of opportunity and areas for concern.