volume 103, number 5, september–october 1998 journal of ... · firefighter safety. the...

Volume 103, Number 5, September–October 1998Journal of Research of the National Institute of Standards and Technology

General DevelopmentsInquiries about News Briefs, where no contact personis identified, should be referred to the Managing Editor,Journal of Research, National Institute of Standardsand Technology, Building 820, Room 126, Gaithersburg,MD 20899-0001; telephone: 301/975-3577.

NIST’S OPEN ARCHITECTURE CONTROLLERSEALS THE DEAL BETWEEN TWO SMALLMACHINE SHOPSNIST’s Enhanced Machine Controller (EMC) free-ware recently “sealed-the-deal” in the sale of a privatecompany’s refurbished milling machine to a secondprivate company. These two local small machineshops are taking advantage of NIST-developed low-cost/high-tech open-architecture technology toenhance theirbusiness.

NIST engineers have been working with industrygroups to develop and validate standards for openarchitecture control of machine tools and other manu-facturing equipment. The EMC project has supportedthe validation effort by establishing testbeds on machinetools at a major automotive company and a majoraircraft manufacturer. A pilot installation investigatinglow-cost implementations of open architecture conceptswas installed at a small job shop in Randallstown, MD.This testbed demonstrated the feasibility of completePC-based control, eliminating much of the costlyspecial-purpose hardware typically required for real-time control. The EMC was installed on a three-axisvertical-milling machine, replacing the original con-troller that had broken. The resulting system proved socost effective that it led to the subsequent sale of themachine to a York, Pa. compnay, which makes heatexchangers. Technicians at the York company arerunning the machine daily, using it for drilling andmilling operations. One significant benefit of an openarchitecture is the use of commodity PC components

News Briefs

and the ability to easily network the controller with theYork company’s Windows 95 office PCs. As a result,programmers can use PC-based computer-aided design/computer-aided manufacturing software to writeprograms in their offices, which are transferred directlyto the EMC on the shop floor.

CONTACT: Fred Proctor, (301) 975-3425; [email protected]

FIRE DETECTION CALIBRATORCOMES ONLINENIST is providing the measurement technology for thefuture of fire detection. Current smoke detectorsprovide a go/no-go signal in the presence of fire-gener-ated particles. Unfortunately, similar aerosols areproduced from other sources such as cooking and con-densing shower steam. In residences, these nuisancealarms often lead to disregard of real fire signals anddisconnection of the sensors. In the cargo holds ofcommercial aircraft, they can force a pilot to undertakean emergency landing. Now, manufacturers are devel-oping a new generation of fire monitors with two differ-ent features: they will contain more than one type ofsensor and they will interpret the responses of thesensors.

NIST scientists have developed a device to measurethe response of both current and future fire productsensors. Built as a result of meetings with fire equip-ment manufacturers, the fire-emulator/detector-evalua-tor (FE/DE) is a laboratory wind tunnel that reproducesthe fire environment that a sensor will experience. TheFE/DE can also simulate the non-fire signals that canlead to nuisance alarms. Thus a manufacturer canobtain data on sensitivity to both the fires of concernand the stimuli to be ignored. These performance dataon sensors of different types and designs will enable theindustry to produce smart fire detectors both for stand-alone use and for integration into intelligent buildings.

CONTACT: William Grosshandler, (301) 975-2310;[email protected].

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NIST’S CRYPTOGRAPHIC MODULEVALIDATIONS APPROACH TWENTYOn June 29, 1998, the DS1954 CryptographiciButton, became the 19th cryptographic module to bevalidated by NIST’s Cryptographic Module ValidationProgram (CMV) for use by Federal agencies. Themodule was validated as conforming to FIPS 140-1,Security Requirements for Cryptographic Modules.FIPS 140-1 specifies four separate levels of securityprovided by Cryptographic Modules, with each levelproviding increased security and assurance. TheiButton was validated to an overall FIPS 140-1 Level2, with Physical Security and EMI/EMC at Level 3.Additionally, the module met the Environmental FailureProtection requirements of Level 4.

This new validation impacts Federal agencies byfurther increasing the number of cryptographic prod-ucts available for use in securing sensitive information.The Cryptographic iButton provides hardware cryp-tographic services such as secure private key storage, ahigh-speed math accelerator for 1024 bit public keycryptography, and secure message digest (hashing). Ser-vices are provided using a single silicon chip packagedin a 16 mm stainless steel case. Thus, the iButton canbe worn by a person or attached to an object for up-to-date information at the point of use. The steel button isrugged enough to withstand harsh outdoor environmentsand is durable enough for a person to wear everyday ona digital accessory like a ring, key fob, wallet, or badge.

The CMV program is a joint effort between NIST andthe Communications Security Establishment (CSE) ofthe Government of Canada. NIST’s security technologygroup together with CSE, serves as the validationauthorities for the program. Currently, there are threeNational Voluntary Laboratory Accreditation Programaccredited laboratories that test cryptographic modules:InfoGard Laboratories of San Luis Obispo, CA;CygnaCom Solutions Laboratory of McLean, VA; andDOMUS Software Limited ITSEC Laboratory ofOttawa, Ontario, Canada.

For more information on FIPS 140-1, validatedmodules, and the accredited laboratories, see the website at http://csrc.nist.gov/cryptval.

CONTACT: Ray Snouffer, (301) 975-4436; [email protected] or Jim Foti, (301) 975-5237; [email protected].

NIST RESEARCHER SPEARHEADSDEVELOPMENT OF FIRST FLAT-PANELDISPLAY MEASUREMENT STANDARDThe Video Electronic Standards Association (VESA)has just published a new standard whose developmenthas been led by a NIST researcher entitled “Flat Panel

Display Measurement (FPDM) Standard, (version 1.0).”Both hard-copy and CD-ROM formats are available.The NIST researcher chairs the VESA FPDM workinggroup that developed the standard; in addition, he devel-oped many of the measurement procedures (and associ-ated cartoons!) included in the document. The standardis designed to provide workers in the field of flat-paneldisplays a basis for making good measurements, using awide variety of instrumentation and using as inexpensiveinstrumentation as possible. In addition to measurementprocedures for flat-panel displays, the standard incorpo-rates a tutorial section on photometry and colorimetryintended to help the novice gain familiarity, by meansof worked problems and discussions, with a difficultsystem of measurements and units. The document alsocontains diagnostic procedures to help ensure thatmeasurements are made properly.

The standard is intended to define display metrologyso that everyone around the world will measure the samethings the same way. Working from the standard, manu-facturers of good displays can state what they have tooffer unambiguously, original equipment manufacturerscan carefully specify what they need, and end users canapply tools to measure the quality of their investment. Asecondary result is to limit the effectiveness of mislead-ing advertisements so that they are more likely to be anembarrassment than a success.

The standard was developed with the assistance ofdisplay-measurements working groups of both the Inter-national Organization for Standardization (ISO) and theElectronics Industries Association of Japan. Discussionsare currently ongoing between VESA and ISO commit-tees regarding adoption of the VESA standard as an ISOstandard.

CONTACT: James A. St. Pierre, (301) 975-4124;[email protected].

REFRIGERANT PROPERTIES DATABASERELEASEDA new version of NIST Standard Reference Database23—Thermodynamic and Transport Properties ofRefrigerants and Refrigerant Mixtures (REFPROP)—has been released. Previous versions of this databasehave become thede factostandard in the refrigerationindustry as well as in research labs for providing theproperty data needed to evaluate the new refrigerantsand to optimize the energy efficiency of heat pumps andother refrigeration equipment.

Version 6.0 of this database is a complete revisionbased on the most accurate pure fluid and mixture mod-els currently available. The models are implemented ina suite of Fortran subroutines that have been completelyrewritten from earlier versions of REFPROP. Routines

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are provided to calculate thermodynamic and transportproperties given a wide variety of possible inputconditions.

A separate graphical user interface, designed for theWindows operating system, provides a convenientmeans of accessing the models. Tables and/or plots forany of 33 pure fluids and for mixtures with up to fivecomponents may be calculated. Commercially availablerefrigerant blends are predefined in the database. Anon-line help system provides information on how to usethe program. Information screens that display fluidconstants and documentation for the property modelscan be called up at any time. Numerous options tocustomize the output are available as well as copy andpaste capabilities to and from other applications.

Funding for the development of REFPROP wasprovided, in part, by DoE and a joint DoE/industryresearch program administered by the Air-Conditioningand Refrigeration Institute (ARI). A provision of theARI support provides free copies of the database to themore than 200 ARI-member companies.

Further information is available from the NISTStandard Reference Data Program at (301) 975-2208 oron the web at http://www.nist.gov/srd/nist23.htm.

CONTACT: Mark O. McLinden, (303) 497-3580;[email protected].

FIRE EXPERIMENTS IN A 13-STORYBUILDINGNIST, in cooperation with the Prince Georges County,MD Fire Department, has conducted fire experiments ina 13-story apartment building in Oxon Hill, MD, tomeasure fire behavior in a realistic setting. Members ofthe large fire research group reconstructed and instru-mented four apartments. Twenty fire experiments wereconducted using a computer-controlled gas burner toprovide a reproducible growing fire. The data fromthese experiments will be used for validation of NIST’sfire models, such as CFAST and the Industrial FireSimulator.

In addition, eight experiments were conducted burn-ing fully furnished living rooms and bedrooms. Two ofthe apartments had automatic fire sprinkler systemsinstalled; two did not. The results from these experi-ments are aimed at improving residential fire safety andfirefighter safety. The International Association ofArson Investigators and the Bureau of Alcohol, Tobaccoand Firearms conducted post-fire investigations on theburned apartments. NIST is cooperating with theseorganizations in an effort to improve scientific methodsused in arson investigation.

CONTACT: Daniel Madrzykowski, (301) 975-6677;[email protected].

QUALITY ASSURANCE STANDARDS FORFORENSIC DNA TESTING LABORATORIESOn July 15, 1998, the director of the FBI formallysigned a document known as “Quality AssuranceStandards for Forensic DNA Testing Laboratories.” Thiscompendium of standards has been developed andreviewed over the past 3 years by the National DNAAdvisory Board.

The document sets forth a set of specific qualityassurance obligations required by all forensic DNAlaboratories that received federal funding. An under-lying premise of the document is that laboratoryaccreditation will be required to demonstrate compli-ance with the standards and, therefore, assure qualitycontrol and a quality program. Standard 9.5 of thedocument requires that “The laboratory shall check itsDNA procedures annually or whenever substantialchanges are made to the protocol(s) against an appropri-ate and available NIST Standard Reference Material orstandard traceable to a NIST standard.” These standardstook effect Oct. 1, 1998.

The DNA Advisory Board charter defines its mem-bership composition to include representatives fromFederal, state, and local crime laboratories as well as aNIST scientist. The inclusion of NIST in the nationscoordinated DNA testing comes as a result of nearly10 years of close working relationships with the FBI indeveloping needed standards for DNA testing. A thirdStandard Reference Material or SRM (SRM 2392) forDNA testing soon will be released, complementing twoother SRMs (SRM 2390 and 2391) used to assureaccurate measurements in human identity testing.

CONTACT: Dennis J. Reeder, (301) 975-3128;[email protected].

NIST MEASUREMENTS HELP INDUSTRYGROW BETTER CRYSTALS FOR RADIATIONDETECTION APPLICATIONThe properties of mercuric iodide radiation detectorshave been enhanced through the observation and identi-fication of structural changes induced through crystalgrowth on two different space shuttle flights. Themotivation for the initial crystal growth flight stemmedfrom the recognition that this material is extremely softat growth temperature. This observation led to theanticipation that a more regular crystal lattice withenhanced properties would be achieved through growthin microgravity.

While the properties of the resulting initial spacecrystal were enhanced, as anticipated, high-resolutionsynchrotron x-ray diffraction imaging showed that itslattice was actually less regular in orientation. However,this decrease in orientational uniformity was more than

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compensated by greater regularity in chemical compo-sition, indicated by the prevention of impurity inclu-sions. The property improvement with space growththus came about more from reduction in convectionmixing of the vapor forming the crystal than fromremoval of gravity loading from the soft growingcrystal.

Subsequent terrestrial growth of purified, second-generation material produced an enhancement in prop-erties, but less than those realized in the initial spacecrystal. Analysis of these terrestrial crystals and similarsecond-generation crystals grown on a second spaceflight showed the property enhancement at this stage tobe limited by incomplete stoichiometry, resulting iniodine inclusions.

More recently, the use of third-generation materialwith fuller stoichiometry has led to terrestrial crystalswith still more enhanced properties. However, while thecrystalline regularity and performance of terrestrialcrystals have been improved substantially, work toachieve full parity with the performance of crystalsgrown in microgravity is under way.

CONTACT: Bruce Steiner, (301) 975-5977;[email protected].

NIST CONTRIBUTION ADDS 50 % MOREDATA TO CRYSTALLOGRAPHICINFORMATION FILEVirtually all materials research is leveraged againstunderstanding how atoms are physically arranged inthese substances, information commonly called the“crystal structure.” While many crystallographers areworking at numerous institutions around the world todetermine this structural information, methods used forcommunication of these results and the data collectedfor this purpose could be significantly improved.

To address this, the Crystallographic InformationFile (CIF), a standardized electronic format for thecommunication of crystallographic data and results,was developed by the International Union for Crystal-lography (IUCr). The initial development of CIF wastargeted for small-molecule crystallographic analysisfrom single-crystal data, with plans to support othercrystallographic methods later. The original deploy-ment of the CIF consisted of a formal syntax and anelectronic dictionary with standard representationsfor over 300 different types of information. The NISTCenter for Neutron Research has led the effort toexpand the scope of the CIF to include powder diffrac-tion through the creation of a dictionary of approxi-mately 200 additional standard representations neededto describe powder diffraction data and results. The

resulting dictionary has been approved by the IUCrCommittee for the Maintenance of the CIF Standard.The format also has been endorsed by other organiza-tions such as the International Centre for DiffractionData. A committee to oversee the maintenance of thepowder dictionary is being formed.

CONTACT: Brian Toby, (301) 975-4297; [email protected].

BETA VERSION DEVELOPED OFCOMPLIANCE TEST SOFTWAREREQUESTED BY IPCAt the request of the Institute for Interconnecting andPackaging Electronics (IPC), a NIST scientist hasdeveloped a beta version Compliance Test Module(CTM) software program to support the GenCAM(Generic Computer Aided Manufacturing) standardunder development by the IPC. The IPC is a tradeassociation representing more than 2300 companies inthe electronic interconnection industry worldwide; IPCmembers include printed circuit board designers, fabri-cators, and assemblers. The GenCAM standard is in-tended to improve the transfer of design information (forelectronic products) from computer-aided design tools,to computer-aided manufacturing tools. Facilitating thistransfer will help to decrease the critical time-to-marketfor electronics manufacturers. GenCAM files could beused to request quotations, to order details that arespecifically process-related, or to describe the entireproduct (printed circuit board and printed circuitassembly) to be manufactured, inspected and tested,and delivered to the customer. GenCam includes thecapability to add information to represent multipleimages of boards to support panel and subpanelfabrication.

IPC views the CTM as a key element in the industrydeployment of the GenCAM standard, recognizing thatone of the main problems with predecessors ofGenCAM was a lack of strong technical support. Thisdeficiency led to misinterpretations by commercialimplementers of earlier standards, which impeded adop-tion of these standards on the part of industry. An articleon GenCAM in the April 1998 issue ofPrinted CircuitDesignmagazine, stated: “The CTM will be made avail-able so that the misinterpretation evident in past imple-mentation strategies can be avoided.” The first officialrelease of the CTM is scheduled for the first quarter ofcalendar year 1999. The CTM currently verifies thesyntax of the GenCAM file, but there are plans to inves-tigate adding checks for a designs “completeness” in thefuture. As a side benefit, the scientist’s CTM develop-ment work has brought to light some ambiguity issues

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within the GenCAM standard itself that have beenaddressed by the development committee, therebymaking GenCAM a more robust standard.


NIST SCIENTIST DEVELOPS NEWSTANDARD FOR ASSESSING RELIABILITYOF ELECTRICAL INTERCONNECTS ININTEGRATED CIRCUITSA new method for calculating the electromigrationmodel parameters for current density and temperaturehas been developed by a NIST scientist and incorpo-rated in a standard method. Electronic IndustriesAssociation/Joint Electron Device Engineering CouncilMethod JESD 63 provides procedures to calculatesample estimates and their confidence intervals for theelectromigration model parameters of current densityand temperature. The model parameter for currentdensity is the exponentn to which the current density israised in a relation known as Blacks equation. Theparameter for temperature is the activation energy forthe electromigration failure process.

Engineers need these parameters to assess thereliability of electrical interconnects in integratedcircuits when they are extrapolating electromigrationfailure-time data obtained under accelerated stressconditions to those conditions of current density andtemperature expected in operational use. The methodrequires existing failure-time or median-time-to-failuredata from a number of accelerated electromigrationstress tests and uses linear regression analyses. Precau-tions and measurement interferences are provided toassist in the design of experiments to obtain the modelparameters. Example calculations to demonstrate themethod are provided in an annex.

CONTACT: Loren W. Linholm, (301) 975-2052;[email protected].

NEW LABORATORY MEASURES CRITICALDATA FOR SEMICONDUCTOR INDUSTRYA new electron transport laboratory has been designedand put into operation at NIST for measuring criticallyneeded electron transport data for modeling plasmadischarges. Such data include electron drift velocities,electron attachment-rate coefficients, and ionization-rate coefficients. Specific data needs are determined onthe basis of thorough reviews of available electroninteraction data for plasma processing gases. Thelaboratory apparatus was designed to make measure-ments for chlorofluorocarbon gases and their mixtureswith argon, nitrogen, and oxygen, which are used

widely in the semiconductor industry for plasmaprocessing. Tests show that the relative uncertainty forthe measured electron drift velocity is 5 % and theuncertainty for the electron attachment and ionizationrate coefficients is 10 %. The new apparatus has beendesigned by taking full advantage of the fast samplingrate and long record length of modern digital oscillo-scopes to provide accurate, simultaneous determinationof the integrated charges of electrons and ions driftingacross a uniform-field gap in separate time scales.

The apparatus was used first to study the effect oftemperature on electron attachment to CCl2F2, and thesedata have been submitted for archival publication.Subsequently, the apparatus was used to measure thefirst electron drift velocities and electron attachmentcoefficients in pure CHF3 and its mixtures with argon.These data recently were presented at the EighthInternational Symposium on Gaseous Dielectrics. Theapparatus recently has been upgraded to handle corro-sive gases to allow measurements of the electron driftvelocities in chlorine and its mixtures with argon. Thesewill be the first experimental data of this type availablefor chlorine and will be used to validate gas-phaseplasma models of the commonly used etching gas.

CONTACT: James K. Olthoff, (301) 975-2431;[email protected].

WORKSHOP HELD ON LEGAL METROLOGYFOR THE AMER ICASA Workshop on Legal Metrology for theAmericas wasrecently held at NIST. It was sponsored by NIST, theNational Conference on Weights and Measures(NCWM), the Organization of American States (OAS),InterAmerican Metrology System(SIM), and the Inter-national Organization of Legal Metrology. Representa-tives from 31 of the 34 OAS member nations partici-pated.

Workshop participants acknowledged that legalmetrology is animportant issue in the globalization oftrade, especially with regard to technical barriersto trade. Moreover, since other regions (Europe,Asia-Pacific, and Africa) have developed regional legalmetrology organizations, the participants consideredwhether the Americas should do the same, especiallysince good metrological cooperation has been growingamong the countries of the Americas through SIM.

Based on discussions between NISTs Office ofStandards Services and the U.S. National Conference onWeights and Measures, including associate membersfrom industry, the workshop had objectives similar tothose of the NIST Standards in Trade Workshops (i.e.,familiarizing participants with U.S. technology andpractices in metrology, standardization, testing, and

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certification and developing professional contacts tostrengthen technical ties and enhance trade amongparticipating countries). Representatives of BrazilsINMETRO and Measurement Canada, and NCWMmembers presented informational items to give a broadperspective of weights and measures practices in theAmericas.

The workshop achieved its main goals: (1) to betteracquaint participants with the weights and measurespractices within the Americas and globally; and (2) tosolicit views and develop aplan of action towardregional cooperation in the development and implemen-tation of legal metrology procedures and practiceswithin the Americas. The group adopted resolutionsto: (1) create a working group on legal metrology inSIM, (2) develop a program structure for that workinggroup, and (3) organize periodic workshops and otherforums to identify and address key issues and needs forfostering future cooperation in legal metrology withinthe Americas.

CONTACT: Chuck Ehrlich, (301) 975-4834; [email protected].

NIST MICROTENSILE TEST APPARATUSDUPLICATED AT PRIVATE COMPANYA NIST scientist worked with a private company’sSemiconductor Products Sector/Advanced InterconnectSystems Laboratory to transfer the NIST microtensiletest apparatus technology to their laboratory. This wasthe culmination of a year of collaboration in which theNIST system was used to test films of various metals,prepared by the private company, as part of NIST’songoing research on mechanical properties of thin filmsfor microelec-tronic applications. The mechanical prop-erties data developed is used in modeling and simulationof chips, packages, and their interconnects using finite-element techniques.

In September 1997, an engineer from the privatecompany, visited NIST to learn the details of thin-filmtensile testing using the NIST apparatus. As a result ofthese interactions, the company decided to establish itsown thin-film tensile testing capability using a replicaof the NIST apparatus.

CONTACT: David T. Read, (303) 497-3853; [email protected].

FOURTH JOINT INDUSTRIAL-ACADEMIC-NIST WORKSHOP HELD ON MACHINE TOOLPERFORMANCE MODELS AND DATAREPOSITORYNIST conducted its fourth National Advanced Manufac-turing Testing workshop on the development of machine

tool performance models and data repository in June1998, in Gaithersburg. The purpose of the workshopwas to review the progress in the development of therepository and plans for the next years developmentactivities.

Forty people representing 15 companies, sevenacademic institutions, and NIST attended the workshop.Additionally, three people participated remotely viateleconferencing and PC netmeeting facilities. Partici-pants assessed progress to date, concluding that thebasic project goals had been proven feasible, and madespecific recommendations with respect to future efforts.NIST, which has an ongoing project in this area, isworking with industry and academia to create a virtualmanufacturing environment to simulate the completemanufacturing cycle in order to reduce the time for newproduct introduction.

The first day of the workshop comprised presenta-tions from industrial, academic, and NIST attendees.The presenters described their efforts in developingmachine tool performance models and data acquisition,identifying the capabilities of their machine tools, anddeveloping new software tools to model and visualizethese capabilities. They also emphasized their efforts indeveloping computing and communication architecturesto enable efficient utilization of machine tool perfor-mance data and the repository.

The second day of the workshop was spent receivingfeedback from the participants related to NIST progress.While participants appreciated the progress that wasdemonstrated, due to the fast pace of technology, theyrecommended modifying the original time schedule thatwas agreed upon in the last workshop to speed up thedevelopment of analytical tools for diagnostics and per-formance tracking. It also was agreed to increase com-munications between the collaborators through elec-tronic means as much as possible. An electronicmeeting will be scheduled in the next months to reviewthe progress.

CONTACT: Alkan Donmez, (301) 975-6618; [email protected].

GOVERNMENT/INDUSTRY SUPPORT FORSYNCHRONIZED MULTIMEDIAINTEGRATION LANGUAGE (SMIL) TO BRINGTELEVISION-LIKE CONTENT TO THE WEBThe World Wide Web Consortium (W3C) recentlyissued a press release citing the Synchronized Multi-media Integration Language (SMIL; pronounced“smile”) specification as a W3C Recommendation,representing cross-industry agreement on a wide rangeof features for putting multimedia presentations onthe Web. A W3C Recommendation indicates that a

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specification is stable, contributes to web interoperabil-ity, and has been reviewed by the W3C membership,who favor its adoption by the industry. NIST is one of260 participating organizations in W3C.

“Synchronized multimedia is becoming increasinglyimportant on the Web. The SMIL Recommendation willenable much-needed interoperability in this area,”explained the W3C director and inventor of the WorldWide Web. SMIL enables authors to bring television-like content to the web, avoiding the limitations fortraditional television and lowering the bandwidthrequirements for transmitting this type of content overthe Internet. With SMIL, producing audiovisual contentis easy; it does not require learning a programminglanguage and can be done using a simple text editor.

The SMIL 1.0 specification was written and devel-oped by the W3C Synchronized Multimedia (SYMM)Working Group, a unique mix of experts from the fourdivergent industries (CD-ROM, interactive television,web, and audio/video streaming) interested in bringingsynchronized multimedia to the Web. The W3C SYMMWorking Group is composed of key industry players aswell as research and government organizations such asCWI (Centre for Mathematics and Computer Science,the Netherlands) and NIST.

NIST also hosts the SMIL Feature List and Interoptesting Testcase, available at http://smil.nist.gov/Feature.html and http://smil.nist.gov/Testcase.html.

CONTACT: Wo Chang, (301) 975-3439; [email protected].

NIST CONTRIBUTES TO THESPECIFICATIONS OF THE ISO/IEC MPEG2PART 10 STANDARD, DSM-CCCONFORMANCE TESTThrough participation in the Moving Picture ExpertsGroup (MPEG) meetings from July 1997 to July 1998,NIST’s high speed network technologies group, collabo-rating with Korean Telecomm, developed and completedthe Digital Storage Media Command and Control(DSM-CC) Conformance Test, ISO/IEC 13818-10,FCD (Final Committee Draft, the first stable versionof a standard that ISO/IEC member countries vote ontoward an international standard). The DSM-CC proto-col controls and manages the displaying of MPEG2streams, the encoded moving pictures and audio bitstreams compressed for storage and transporting overnetworks.

CONTACT: Karen Hsing, (301) 975-3656; [email protected].

SEM MONITOR WINS R&D 100SEM Monitor, co-developed by a NIST scientist, hasbeen awarded one of the 1998 R&D 100 awards givenby R&D Magazine.The development of SEM Monitoris a collaborative project between NIST and two privatecompanies. The aim of the project was to answerthe question: “Can the performance of an automatedproduction line scanning electron microscope (SEM)tasked to control a multimillion dollar semiconductorfabrication line be monitored for data fidelity?”

SEM Monitor is designed to be an objective diagnos-tic aid for semiconductor scanning electron microscope-based metrology andinspection. It provides a simplequantitative framework for monitoring a SEMs resolu-tion, astigmatism, and image quality both over time fora single instrument or compared to other machines.SEM Monitor also can be used to adjust and align aSEM for optimum performance. SEM Monitor is arevolutionary approach to solving a major problem en-countered in the inspection of wafers in the automatedSEM metrology environment, namely “is the metrologyinstrument performing optimally” and thus is it provid-ing correct, believable data.

SEM Monitor is available in either a fully functionalstand-alone workstation version ready to be connected tothe scanning electron microscope or as softwarepackage alone. In either case the package includes theMetrologia modeling package which includes sophisti-cated modeling for both electron and optical micro-scopes. Metrologia allows the user to simulate the beamspecimen interaction of the microscope and is based ondetailed physical models solving Maxwells equations forthe optical cases and using Monte Carlo techniques forthe electron microscope cases. The combination ofSEM Monitor with Metrologia offers process engineersa powerful set of multipurpose utilities for optimizingthe accuracy of their metrology.

CONTACT: Michael Postek, (301) 975-2299; [email protected].

SMALLER MANUFACTURERS: SWAT THE“MILLENNIUM BUG” WITH SELF-HELP TOOLThe NIST Manufacturing Extension Partnership’s(MEP) nationwide network of centers is offering a com-puter-based tool to help smaller manufacturers find andassess Year 2000 date problems. Year 2000, or Y2K,refers to the failure of a computer program or systembecause the “00” year designation is mistaken for“1900.”

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“Time is running out. Like other businesses, smallmanufacturers must start paying attention to this poten-tial problem today. If they don’t, they risk losing busi-ness or even their ability to survive,” said CommerceSecretary William Daley.

MEP’s tool will help smaller manufacturers conductan inventory of equipment, identify core business sys-tems and rate their importance to the survival of thebusiness, develop contingency plans, and develop andmanage remediation projects.

For assistance with Year 2000 conversion, as well asbusiness and technical projects, smaller manufacturerscan call (800) MEP-4MFG (637-4634) to reach theMEP center serving their region. Information also isavailable on the World Wide Web at http://www.mep.nist.gov and at http://www.nist.gov/y2k.

Media Contact: Jan Kosko (301) 975-2767;[email protected].

STUDY TAKES FIRST STEP TOWARD LESSCOSTLY FRESH AIRMany home builders are moving toward more energyefficient designs, yet concerns about proper ventilationand indoor air quality are fueling an increase in the useof mechanical ventilation systems. Unfortunately, theprice of better indoor air quality with these systems maybe higher heating and cooling bills.

A recently completed NIST study found that a homewhere exhaust fans or other mechanical ventilationsystems provide additional air flow may have too muchventilation at some times and too little at others. Over-ventilation during winter and summer months typicallyproduces higher utility bills.

The study employed a NIST-developed computerprogram called CONTAM to evaluate the interplay ofenergy-efficient design, mechanical ventilation, andpower consumption. The two-story fictitious houseused in the study is in Spokane, WA, an area that hascool winters and where builders are typically moreprogressive about energy efficient designs. One-yearsimulations evaluated four different ventilationapproaches. Future simulations will evaluate otherhousing designs in various climates.

Ultimately, researchers hope to devise an indoor airquality rating scheme that can be used by manufacturersand designers to evaluate the impacts of different meansof controlling indoor air quality. Information about theinterplay of energy efficiency and optimum ventilationwill help builders to evaluate the tradeoffs involved inbuilding designs.

The Electric Power Research Institute sponsored thestudy under a cooperative research and developmentagreement.

For more information, contact Andrew Persily, A313Building Research Building, NIST, Gaithersburg, MD20899-0001, (301) 975-6418, [email protected].

Media Contact: Philip Bulman (301) 975-5661;[email protected].

NEW STANDARD HELPS COMPUTERMAKERS ASSESS FLAT-PANEL QUALITYManufacturers long have needed a comprehensivemanual to help them carry out the complex tests neededto accurately specify and measure performance charac-teristics such as sharpness, brightness, and color qualityof the flat-panel displays they use in laptop computers.Until now, they have had to resort to time-consumingperformance evaluations before they could decide whichdisplays to order.

Fortunately, that problem has been solved by an inter-national team of researchers led by a physicist at NIST.The group produced the first comprehensive manual fortesting flat-panel displays. The resulting Flat PanelDisplay Measurement Standard has been published bythe Video Electronics Standards Association, an inter-national organization representing corporations in thecomputer industry.

By using the same standard, display producers andlaptop manufacturers can speak the same language,ensuring less ambiguity and faster production.

One of the research team’s chief triumphs was animproved method for measuring a display’s contrastratio, which dictates the sharpness of an image by virtueof its ratio of whiteness to blackness. The new methodworks by using a cone-shaped device to screen outthe glare of extraneous light that interferes with themeasurement.

Copies of the standard can be ordered from VESA inboth CD-ROM and hard copy formats. Contact VESA at2150 N. First St., Suite 440, San Jose, CA 95131-2029,(408) 435-0333, or download an order form (using anAdobe Acrobat 3.0 reader) from the organization’sWorld Wide Web site at http://www.vesa.org.

For more information, contact James St. Pierre, A53Technology Building, NIST, Gaithersburg, MD 20899-0001, (301) 975-4124, [email protected].

Media Contact: Emil Venere (301) 975-5745; [email protected].

FEDERAL/STATE STUDY FINDS 19 % OF MILKCONTAINERS SHORTIn the first national study on the accuracy of milk netcontents, conducted by four federal agencies, 44 statesand two territories, 19 % of 3355 lots of milk inspectedfailed due to underfilling. The results of the study are

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significantly better than results of a similar, but smaller,study conducted in 1997 in which 45 % of inspected lotsfailed.

The study was conducted by the staff of the FederalTrade Commission, Food and Nutrition Service at theU.S. Department of Agriculture, and the NIST Office ofWeights and Measures, in coordination with the Officeof Food Labeling at the Food and Drug Administration.Inspections were conducted by weights and measuresofficials in 44 states as well as Puerto Rico and the U.S.Virgin Islands using an inspection procedure adoptedby the National Conference on Weights and Measures.Inspections were conducted in retail stores, dairies,hospitals, universities, public schools, and otherinstitutions.

More than 6 billion gallons of milk were sold in theUnited States last year, according to the USDA.According to the report, 83 % of lots inspected atschools this year passed inspection. At hospitals,universities, and other institutions, 72 % passed. Of the1309 inspections of milk in retail stores, wholesalepackaging plants, and dairies, 81 % passed inspectionthis year.

Copies of the study, “Milk: Does it Measure Up? OneYear Later,” and a “Facts for Business” brochure areavailable on the World Wide Web at http://www.ftc.gov. Printed copies can be requested from the FTC’sPublic Reference Branch, Room 130, 6th Street andPennsylvania Ave., NW, Washington, DC 20580,(202) 382-4357.

Media Contact: Linda Joy (301) 975-4403; [email protected].

PORTABLE JOSEPHSON VOLTAGESTANDARD PASSES INITIAL TESTSA compact, transportable 10 V Josephson calibrationsystem developed at NIST is now circulating amongnine NASA laboratories where it is used as a primarystandard. A model with an improved microwaveoscillator will be tested shortly at several Department ofEnergy national laboratories.

The portable standard, which weighs only 21 kg, ishighly automated and is designed to be operatedby technicians without higher level support. It can betransported easily by next-day air shipment in twocustom containers and set up in less than 1 hour. It iscooled in a standard 100 L liquid helium transportDewar that is sufficient to operate the Josephson arrayfor 6 to 8 weeks.

The standard was intercompared with laboratorystandards at NIST and Sandia National Laboratoriesand by members of the National Conference of

Standards Laboratories. It tested well within defineduncertainty levels in these intercomparisons.

The standard also was field tested at two NASAlaboratories—the White Sands (NM) Test Facility andthe Kennedy Space Center in Florida. In addition to thefield tests, the standard has been operated at threeNASA calibration laboratories resulting in “markedimprovement” in the value of the maintained volt for onelaboratory and verifying the low uncertainties claimedat the other two laboratories.

For a copy of paper no. 29-98 describing the fieldtests, contact Sarabeth Harris, MS104, NIST, Boulder,CO 80303-3337, (303) 497-3237, [email protected].

Media Contact: Fred McGehan (Boulder), (303)497-3246; [email protected].

NEW CONSORTIUM EXAMINES FLAMERETARDANCY IN PLASTICSUnderstanding the fundamental mechanisms of flameretardancy in certain plastics is important because firesstarted in the synthetic fabrics found in furniture andcarpeting frequently cause deaths, serious injuries, andproperty damage. Several companies have thereforejoined a NIST-sponsored research consortium to betterexamine these characteristics.

The plastics being studied by the consortium areclay-nanocomposites, materials in which clay plate-likeparticles, 1 nm thick by 1000 nm in diameter, aredispersed throughout the polymers involved. PreviousNIST research showed that a commonly used polymer,nylon-6, became much less flammable—by 63 %—if ithad a clay content of only 5 %. More recent findingsshow that the approach of molecularly dispersing clayboosts flame retardancy in many polymers.

The new research consortium will last at least 2 yearsand will examine a variety of materials to discover ifthe flame retardancy depends on physical properties,chemical properties or both. Additional companies canjoin until Sept. 30, 1998.

For more information on the consortium, contactJeffrey Gilman, B258 Polymer Building, NIST,Gaithersburg, MD 20899-0001, (301) 975-6573;[email protected].


UPDATED “ONE-STOP” INDUSTRY GUIDETO NIST AVAILABLEThe newGuide to NIST, the third update of the popular“one stop” information resource, is now available. The

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184-page volume describes hundreds of differentresearch projects, grants, industry outreach programs,services and facilities.

The guide is divided into sections covering each ofthe agency’s four major programs: the Measurementand Standards Laboratories; the Advanced TechnologyProgram, the Manufacturing Extension Partnership, andthe Baldrige National Quality Program. Individualitems include contact names, addresses, phonenumbers, e-mail addresses and, where present, WorldWide Web URLs. A detailed subject index clearly mapsall paths.

The completeGuide to NISTalso is availableon the World Wide Web at http://www.nist.gov/public_affairs/guide/index.htm.

For a free copy, send a self-addressed mailing labelto Public Inquiries, A903 Administration Building,NIST, Gaithersburg, MD 20899-0001 or fax requests to(301) 926-1630.

Media Contact: Michael E. Newman (301) 975-3025; [email protected].

15 CANDIDATES FOR ADVANCEDENCRYPTION STANDARD CHOSENNIST has announced the acceptance of 15 encodingalgorithms as candidates for the new AdvancedEncryption Standard (AES). Researchers from 12 dif-ferent countries worked on developing the formulasunveiled at the First Advanced Encryption StandardCandidate Conference in Ventura, CA, in August 1998.

NIST is inviting the worldwide cryptographicresearch community to “attack” the formulas in anattempt to break the codes during the first evaluationperiod, which will end April 15, 1999. Additionally,NIST will evaluate the algorithms for factors such assecurity and speed.

Five or fewer finalists will be identified by the end ofthe summer of 1999. NIST eventually will propose thatone of these finalists be adopted as the AES. However,detailed analysis is required before this can happen, andthe process is structured to build confidence in the AES.Consequently, the process is unlikely to be completedbefore 2001.

The AES will provide security for encrypted data. Itwill be a public algorithm designed to protect sensitivegovernment information well into the next century.The AES will replace the Data Encryption Standardcurrently used by many Federal agencies and busi-nesses. NIST adopted DES in 1977 as a FederalInformation Processing Standard for use by Federalagencies to encrypt sensitive information.

NIST has accepted the following algorithms ascandidates. The list includes the algorithm name, thesubmitters’ names, and submitters’ countries:

• AST-256—Entrust Technologies,Canada;

• RYPTON—Future Systems Inc., South Korea;

• DEAL—Richard Outerbridge and Lars Knudsen,Canada and Norway;

• DFC—Centre National pour la Recherche Scien-tifique, France;

• E2—Nippon Telegraph and Telephone Corp., Japan;

• FROG—TecApro Internacional S.A., Costa Rica;

• HPC—(Hasty Pudding Cipher) Rich Schroeppel,U.S.A.;

• LOKI97—Lawrie Brown, Josef Pieprzyk andJennifer Seberry, Australia;

• MAGENTA—Deutsche Telekom AG, Germany;

• MARS—IBM Corp., U.S.A.;

• RC6—RSA Laboratories, U.S.A.;

• Rijndael—Joan Daemen and Vincent Rijmen,Belgium;

• SAFER+ Cylink Corp., U.S.A.;

• SERPENT—Ross Anderson, Eli Biham and LarsKnudsen, U.K., Israel and Norway;

• TWOFISH—Bruce Schneier, John Kelsey, DougWhiting, David Wagner, Chris Hall and NielsFerguson, U.S.A.

More information about the AES is available athttp://www.nist.gov/aes. A list of press contacts at theorganizations that have submitted candidate algorithmscan be obtained at http://www.nist.gov/public_affairs/releases/n98-15.htm or by faxing a request to (301) 926-1630.


NEW PRIMER HELPS IMPROVE USE OFELECTRON-BEAM MOIRE´ TECHNIQUEEngineers and researchers in the area of electronicspackaging will want to get a new publication from NISTthat describes procedures for the relatively new elec-tron-beam moir technique which measures submicrom-eter strains on a local scale in electronic packaging.In particular, it can measure the thermomechanical

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displacement caused by thermal expansion mismatchesamong the various materials used in an electronicpackage.

Measurements of displacements can be used tovalidate computer models or otherwise contribute to theassessment of the reliability of the packaging. The newpublication describes the background, setup and proce-dures for the electron-beam moire´ technique and isintended to give readers enough information so that theycan conduct an experiment in their own laboratories.Such experiments would include a scanning electronmicroscope, access to electron-beam or other type oflithography process, and computers to run the litho-graphy process and aid in reducing and analyzing thedata.

The publication covers specimen preparation,electron-beam lithography, thermal testing, mechanicaltesting, and analysis of the moire´ fields. It also contains,as appendices, nine papers on electron-beam moire´theory and applications by NIST authors. A programdisk is included with the publication.

To order a single, free copy ofProcedures for theElectron-Beam Moire´ Technique(NIST Technical Note1500-2), contact Elizabeth S. Drexler, MC 853.08,NIST, Boulder, CO 80303-3337, (303) 497-5350;[email protected].

Media Contact: Fred McGehan (Boulder), (303) 497-3246; [email protected].

BROCHURE DETAILS VALUABLESTANDARDS RESOURCENow in its 33rd year of operation, the NIST-managedNational Center for Standards and CertificationInformation serves as a referral service and focal pointin the United States for up-to-date information aboutstandards, technical regulations, and conformity assess-ment programs—domestic, foreign and international.The center’s staff respond to inquiries, maintain areference collection of standards and standards-relateddocuments, and operate two telephone hotlines thatprovide information on proposed foreign technicalregulations issued by the World Trade Organization(301-975-4041) and draft European Union/EuropeanCommunities standards (301-921-4164).

A new brochure prepared by NIST details theservices offered by the NCSCI. The document explainshow the center operates, describes the reference collec-tion, and guides potential users on the best ways toaccess the many resources available.

Copies of the brochure may be obtained by sendinga self-addressed mailing label to the NSCSI, Building820, Room 164, NIST, Gaithersburg, MD 20899-0001.

Copies also may be requested by calling (301) 975-4040, faxing (301) 926-1559 or sending electronic mailto [email protected].

Media Contact: Mark Bello (301) 975-3776; [email protected].

UPGRADED WEBSITE KEEPS THEMILLENNIUM BUG FROM BUGGINGFree software that assesses “millennium bug” problemsis only one of many features on the new and improvedNIST Year 2000 World Wide Web page located athttp://www.nist.gov/y2k. NIST recently redesigned thepage, making it easier to navigate and more comprehen-sive in the services it offers. For example, new docu-ments now are added on a regular basis to ensure timelyinformation. Perhaps most importantly for the wearyweb traveler, the page includes links to a selective list ofoutstanding and informative Year 2000 web sites run byindustry and government groups.

NIST has developed a variety of programs to helpboth small and large companies in the Year 2000 conver-sion process. The projects are part of a larger effortcoordinated by the President’s Council on the Year 2000Conversion.

For technical information, contact Gary E. Fisher,Building. 820, Room 562, NIST, Gaithersburg, MD20899-0001, (301) 975-3275, [email protected].


N-WEST TO HELP SET DIRECTIONFOR WIRELESS INDUSTRYThe National Wireless Electronic Systems Testbed, anew measurements and standards resource, recentlybegan its effort to create and carry out tests and mea-surements, and promote sound operational standards andspecifications for the broadband wireless industry.These are considered essential for rapid development ofnewly allocated wireless spectrum.

N-WEST is oriented toward broadband wirelessaccess, which will offer high-speed two-way data, Inter-net, telephone, and video services to businesses,schools, libraries, health care providers and eventually,private homes. “Hub” transceivers on towers spaceda few kilometers apart each will serve up to severalthousand customers with small rooftop antennas. One ofN-WEST’s primary concerns is the Local MultipointDistribution Service, a recently auctioned block ofspectrum around 28 GHz to 31 GHz.

N-WEST is a project of NIST and another CommerceDepartment agency, the National Telecommunications

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and Information Administration. N-WEST currently isorganizing an industry standardization effort in con-junction with service providers, system integrators,component manufacturers, and others.

For more information, contact Roger B. Marks, MC813.06, NIST, Boulder, CO 80303-3337, (303) 497-3037, [email protected]; or visit the N-WESTWebsite at http://nwest.nist.gov.

Media Contact: Collier Smith (Boulder), (303) 497-3198; [email protected].

NIST TEST BLOCKS NOW AVAILABLE;ROCKWELL C HARDNESS SCALE REVISEDThe hardness of a metal reveals its strength and otherproperties, which are evaluated for quality controlduring and after the manufacture of products. Hardnessis gauged by using special test equipment to make smallindentations in the metal. A hardness value is assignedto the metal based on the depth of the indentation. Toensure that these testing devices are accurate, NIST isnow providing U.S. industry with highly precisecalibration test blocks.

The test blocks are specifically for the mostfrequently used hardness standard—the RockwellC scale (known as HRC)—with which industries gaugethe hardness of certain steels. The high quality of theagency’s calibration artifacts results from two NIST-developed innovations: a precision “dead-weightstandardizing” machine for measuring Rockwellhardness and a sophisticated method for measuringthe shapes of the diamond tips used to make testindentations.

An international comparison with other standardizinglaboratories showed the NIST data to be nearly identicalto those used in Japan and Italy. However, the researchalso revealed that the commercially accepted U.S. scalefor the Rockwell C standard is about 0.2 to 0.8“hardness points” lower than the NIST scale, dependingon the hardness level of the metal. Conforming to theNIST scale will help U.S. industry come in line with therest of the world.

Because companies use large numbers of hardnessblocks to perform tests during production, NIST soonwill begin a voluntary accreditation program for testblock manufacturers so that they can produce commer-cial blocks that are traceable to NIST.

NIST eventually will produce test blocks for many ofthe 30 different Rockwell hardness scales.

For more information, contact Sam Low, B254Materials Building, NIST, Gaithersburg, MD 20899-0001, (301) 975-5709, [email protected].

Media Contact: Emil Venere (301) 975-5745;[email protected].

NEW METHOD MAY LEAD TO BETTERINSULATORS AND FASTER MICROCHIPSCertain plastics are well-suited for the job of insulatingcomputer chips. But because they sometimes turnrubbery as temperatures rise, the heat of an operatingcomputer may lead to insulation breakdown and, in turn,chip failure.

Therefore, NIST scientists have formulated a newmathematical theory for measuring the viscosity ofpolymers in thin layers. This allows them to studyprecisely how extremely thin layers of plastic polymersflow when heated.

To make the measurements necessary for theirtheory, the NIST team had to design and build anentirely new instrument: the twin-crystal resonator.

The point at which a specific polymer turns rubberyis called its glass transition temperature. To determineprecisely at which temperatures and thicknesses thistransition takes place, the NIST researchers are study-ing changes in a polymer’s viscosity. With the twin-crystal resonator, viscosity can be analyzed by coatingquartz crystal with an ultrathin layer of plastic and thenrecording changes in the crystal’s response to anoscillating electric current.

So far, they have discovered that the changes takeplace when polymers are produced in layers no thickerthan 300 nm. The researchers believe their techniquehas the potential to measure properties in far thinnerfilms as well.

For more information, contact Christopher White,B320 Polymer Building, NIST, Gaithersburg,MD 20899-0001, (301) 975-6016, [email protected].


CENTER HELPS HYDRAULICS COMPANYLIFT ITS EFFICIENCY, SALESA Reedsburg, WI, manufacturer of filters and valves forhydraulic systems needed help to overcome inefficien-cies in its production system. So the call went out to theWisconsin Manufacturing Extension Partnership(WMEP), an affiliate of the nationwide NIST MEPassisting smaller manufacturers in all 50 states andPuerto Rico.

WMEP first performed a comprehensive assessmentof the manufacturer’s operations and, based on the data,facilitated a cross-functional team to define and priori-tize issues with potential bottom-line impact. Employeeteams then were established to work on key prioritiesfor process improvement.

The results? Production lead time decreased 25 %,inventory costs were reduced 35 %, on-time shipping

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improved by over 100 % and, best of all, sales increased55 %.

“WMEP installed the mindset and the skills,” says thecompany chairman. “We are much better today than wewere a year ago because of the discipline we learnedfrom WMEP. And we will be a better company next yearthan we are today. What WMEP started will never end.”

Smaller manufacturers can call (800) MEP-4-MFG(637-4634) to reach the MEP center serving theirregion, or check out the MEP World Wide Web site athttp://www.mep.nist.gov.

For more information on WMEP, call (608) 240-1740or send an e-mail message to [email protected].

Media Contact: Jan Kosko (301) 975-2767; [email protected].

NEW VERSION OF REFRIGERANT DATABASERELEASEDA new version of NIST Standard Reference Database23, Thermodynamic and Transport Properties ofRefrigerants and Refrigerant Mixtures (known asREFPROP), has been released. Previous versions ofthis database have become the de facto standard in therefrigeration industry as well as in research labs forproviding the property data needed to evaluate newrefrigerants and to optimize the energy efficiency ofheat pumps and other refrigeration equipment.

Version 6.0 of this database is a complete revisionbased on the most accurate pure fluid and mixturemodels currently available. The models are implementedin a suite of Fortran subroutines that have been rewrittencompletely from earlier versions of REFPROP. Routinesare provided to calculate thermodynamic and transportproperties for a wide variety of possible input condi-tions. A separate graphical user interface, designed forthe Windows operating system, provides a convenientmeans of accessing the models.

Among the database’s other features are:

• the ability to calculate tables and/or plots for any of33 pure fluids listed and for mixtures up to fivecomponents;

• the convenience of commercially available refriger-ant blends being predefined in the database;

• an online help system for ease in using the program;

• information screens that display fluid constants anddocumentation for the property models; and

• numerous options to customize the output.

For more information, contact the NIST StandardReference Data Program at (301) 975-2208,[email protected], or go to http://www.nist.gov/srd/nist23.htm on the World Wide Web.

Media Contact: Fred McGehan (Boulder), (303)497-3246; [email protected].

INNOVATIVE MICROSCOPE READY TOMEASURE INDUSTRY SAMPLESA calibrated atomic force microscope (C-AFM), adevice that makes highly accurate, nanometer-scalemeasurements based on the wavelength of light,currently is testing nano-engineered grids and otherreferences used to ensure the accuracy of dimensionalmeasurements critical to semiconductor processing.If the trial measurements of the industry-supplied refer-ences are successful, the C-AFM soon will be thecenterpiece of a full-fledged NIST measurementservice, and, ultimately, a calibration service.

The planned service will address the measurementneeds of the growing number of users of AFMs andother types of scanning probe microscopes. Industrialapplications of AFMs, in particular, are multiplying asthe scale used to measure the dimensions of integrated-circuit features and other kinds of devices drops from10–6 m to 10–10 m. Initial calibration services will focuson tools for pitch (the spacing between lines and spacesor other features on a chip) and step height (the levelson a chip or wafer) measurements. Capabilities formeasurements of linewidth (the width of a patternedfeature) are under development.

The instrument’s measurements in all three dimen-sions are traceable to the wavelength of light. Over its50 mm range, the instrument achieves a lateral resolu-tion of better than 1.2 nm and a vertical resolution downto 4 pm.

For measurements of step height, the uncertainty isabout 0.4 % of scale. The instrument has been used toevaluate silicon samples with regular, terrace-likefeatures that could serve as references for sub-nano-meter measurements of step height. For pitch measure-ments, an uncertainty of about 0.1 % of scale has beenachieved.

Through refinements of the instrument, NISTresearchers aim to reduce measurement uncertaintyeven further and to speed up its performance so that itcan accommodate sizable calibration workloads.

During the initial operating period of the C-AFM,suitable samples are being accepted from customers ona limited basis for measurement with the device.Organizations interested in having their samples mea-sured or seeking more technical information maycontact Ronald Dixson, A117 Metrology Building,NIST, Gaithersburg, MD 20899-0001, (301) 975-4399,[email protected].


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VIDEO HIGHLIGHTS METROLOGY DONETHE LONG-DISTANCE WAYPrecise and accurate microscopic examination ofmaterials is critical to many aspects of manufacturing.Such metrology is particularly important to semicon-ductor manufacturers. However, many companies donot have the advanced microscopy and microanalysisinstrumentation and expertise needed on site or withineasy access.

The telepresence project of NIST’s NationalAdvanced Manufacturing Testbed is seeking to addressthis problem by demonstrating and refining “long-distance” sharing and operation of electron microscopesat NIST’s Gaithersburg, MD, site. The links connectingtest customers to NIST are via inexpensive telecon-ferencing hardware/software that utilize World WideWeb-based technology.

A new NIST video, “You Don’t Have to Be There ...Telepresence Microscopy,” highlights the ongoingproject. The 12 1/2 min program shows how telepres-ence can provide remote, instantaneous, around-the-clock access to critical metrology services, savingcustomers time and money while helping ensure thequality of manufactured goods.

For a free copy of the video, contact NIST PublicInquiries by fax at (301) 926-1630 or electronic mail [email protected]. For more information on the tele-presence microscopy project, contact Michael Postek,A117 Metrology Building, NIST, Gaithersburg, MD20899-0001, (301) 975-2299, [email protected].

Media Contact: Michael E. Newman (301) 975-3025; [email protected].

NIST DEVELOPMENT CONTRIBUTES TOSUCCESS OF DISPLAY “SHOOT-OUT”NIST scientists chose the INFOCOMM InternationalExposition to reveal their stray light elimination tube(SLET) as applied to meas-urements of projectiondisplays made during the events Projection Shoot-Out. The SLET is a device used to aid in makingprojection display light-output measurements in highambient light conditions. The SLET was used in theShoot-Out to monitor the test display source during thenormalization process, to evaluate the effects of differ-ent display lamp sources on the different light-measur-ing device (LMD) technologies, and to evaluate theeffects of reflections on the LMDs. Reflections, such aslight reflected back from the room walls and LMDoperators, can corrupt light output measurements.These evaluations helped materially to improve theconfidence of the Shoot-Out measurement process.

Every year, the International Communications Indus-tries Association Inc. (ICIA) holds its ProjectionShoot-Out to provide an opportunity for INFO-COMM attendees to judge the quality of individualprojection displays in a side-by-side comparison in adarkened room (non-laboratory) environment. Thisyear, a team was assembled tomeasure the light outputof the 107 displays at the Shoot-Out, and NIST wasasked to provide technical consultation and support forthe measurements. Two different quantities weremeasured: light output (luminance for self-containeddisplays and flux for the front-projection systems) andthe correlated color temperature. The NIST teamcoordinated the relative normalization of the variousLMDs employed, provided error analysis of themeasurements, and offered technical consultation whenneeded. The results of the measurements are posted atthe ICIA web site (http://www.icia.org).


NIST PROJECT AFFECTS NONLINEARSYSTEM IDENTIFICATION AND CONTROLNISTs work on chaotic structural dynamics is havingfar-reaching effects in nonlinear system identificationand control. NIST developed the stochastic Melnikovapproach to study transitions from safe to unsafe typesof behavior such as snap-through buckling of structures.It is likely to have a significant effect on the stochasticresonance community. The stochastic Melnikovapproach also has been adopted in studies of nonlinearcontrol of stochastically exited systems in Belgian andRussian laboratories.

CONTACT: Emil Simiu, (301) 975-6076; [email protected].

NEW INTERPRETATION OF THE SI FOR THEUNITED STATES PUBLISHEDA new interpretation of the International System ofUnits (SI) for use in the United States was published inthe July 28, 1998, issue of theFederal Register(FR 6340334-40340). The new interpretation of the modernmetric system replaces the interpretation published inDecember 1990. The Metric Conversion Act of 1975gives the Secretary of Commerce the authority tointerpret or modify the SI for U.S. use, and this author-ity has been delegated to the NIST Director. Since thepublication of the 1990 interpretation, the internationalbodies responsible for the SI made some significantchanges to it, and it became necessary to set forth a new

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interpretation. These changes include: (1) the additionof four new SI prefixes to form decimal multiples andsubmultiples of SI units; (2) the elimination of the classof supplementary units (the radian and steradian) as aseparate class in the SI; and (3) changes in the units notpart of the SI that can be used with it. The newFederalRegisternotice may be accessed via the NIST Referenceon Constants, Units, and Uncertainty, the web site of theFundamental Constants Data Center at http://physics.nist.gov/cuu.

CONTACT: Barry N. Taylor, (301) 975-4220; [email protected]

JOINT FREQUENCY-STANDARDDEVELOPMENT PROJECT COMPLETEDA joint project between NIST and Japan’s Communi-cations Research Laboratory (CRL) to develop animproved version of NIST-7, the U.S. primaryfrequency standard, was completed recently. The objec-tives of this project were to construct an opticallypumped standard with an uncertainty comparable to thatof NIST-7, to compare this new standard with NIST-7,and to improve a number of subsystems allowingfor more rapid, automated evaluation of systematicfrequency offsets.

Major improvements made during the projectincluded a more robust diode-laser system for opticalstate preparation and detection, new servo-control andmonitor software using a more flexible object-orientedapproach, identification of a number of smaller sourcesof systematic offset, and improved modeling of severalof the larger systematic frequency shifts. Improvementsmade to the new standard during this developmentproject will be incorporated in NIST-7.

Aside from these improvements, the key benefitof this project was the demonstration of agreementbetween these independent standards. The final com-parisons between the new standard and NIST-7 indicateagreement within the nominal relative uncertainty ofeach of the standards. It would have been difficult forNIST to justify construction of a second standard for thispurpose.

CONTACT: Robert E. Drullinger, (303) 497-3183;[email protected].

NARROWEST LINEWIDTH LASERDEMONSTRATEDNIST researchers recently constructed the narrowestlinewidth visible laser ever reported. NIST researchersworking with a Brazilian guest researcher developed thelaser during research on optical frequency standards.

The ultimate goal of this project is to lock a narrow-linewidth laser to a well defined (282 nm, 2 Hzlinewidth) transition in199Hg+ ions. The resulting opti-cal frequency standard could be used directly in theoptical region or frequency divided to the microwaveregion to serve as a traditional atomic clock.

To demonstrate the performance of the new lasersystem, the difference frequency (beatnote) betweentwo laser beams, locked to independent referencecavities on independent isolation platforms, was shownto have a linewidth of 0.8 Hz for an averaging time of40 s. This measurement implies a linewidth for eitherlaser of less than 0.6 Hz, corresponding to a fractionallinewidth of about 1.1310–15. The key to this result isthe isolation from seismic and acoustic noise and frompressure and temperature fluctuations of the high-finesse optical cavities used to stabilize the lasers.

The laser performance now exceeds requirements foruse as a local oscillator for the optical mercury-ionfrequency standard. Since systematic frequency shiftsfor the optical frequency standard are anticipated to bevery small, this new standard should perform better thanall previous frequency standards.

CONTACT: James C. Bergquist, (303) 497-5459;[email protected].

MODELING THE ALIGNMENT OF PRECISIONOPTOELECTRONICS INTERCONNECTSScientists at NIST have developed models that help theelectronics industry predict the forces controlling thecritical alignment of optoelectronic components. Solderis used in optoelectronic assemblies to couple opticalfibers to lasers and diode sensors. During the assemblyprocess, the fiber is positioned for maximum opticalthroughput but may shift out of alignment during themelting and solidification of the solder droplet due tosolder surface tension while it is molten, and due tosolder shrinkage during solidification and cooling. Tomake use of higher bandwidth single mode opticalfibers in the next generation of optical communications,however, the fibers and devices must remain alignedwith micrometer tolerances throughout the lifetime ofthe interconnect. Consequently, the assembly must bemanufactured with submicrometer tolerances.

Models of the assembly process, developed by NISThave provided a new design tool for precision optoelec-tronics assembly for industry. Bycalculating the extentof fiber shifting during assembly, including both surfacetension and solidification effects, this modeling technol-ogy is expected to lead to more robust designs of theinterconnect. Without the models, very extensive andexpensive experimentation would be required to achieve

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the same effect. These results are being applied now tospecific problems addressed by NIST and industry.

CONTACT: Adam C. Powell IV, (301) 975-4936;[email protected].

NEAR INFRARED SPECTROSCOPY TESTEDFOR ONLINE MOISTURE MEASUREMENTFOR CERAMIC INDUSTRYMoisture content and distribution throughout a greenceramic body is critical to controlled processing butcannot be measured quickly. NIST, collaborating withmembers of the Ceramic Processing CharacterizationConsortium, successfully completed field tests in aprivate company’s production line. Two, online,complementary near infrared (NIR) spectrometers wereused for the field tests: a motion-free spectrometer withacousto-optic tunable filter, and a hand-held NIR.Online NIR intensities were measured for differentprocessing stages for the entire production line (from“dry powder”, mixing, pugging, shape-forming, todrying) and moisture contents calculated. For the hand-held unit, in addition to the total moisture content, thevariation in moisture content at different locations in thegreen body, homogeneity, and the effect of the dryeralso were measured. For the motion free unit, bindercontent and moisture also were measured. Based uponthe results, the company determined the techniques tobe valuable for their quality control and is currentlyselecting a system to install online.

CONTACT: Pu Sen Wang, (301) 975-6104;[email protected].

EXPLANATION OF UNEXPECTED CHATTERMAY LIE IN NONLINEAR DYNAMICSThe occurrence of chatter vibrations is a limiting factorin the material removal rates in milling and turningoperations. Accurate predictions of the so-called chatterstability boundary for material removal processes longhave been desired. While much effort has gone into thedevelopment of linear stability analyses targeted atproviding this information, these models do not consis-tently predict the onset of chatter.

Machinists long have been aware that chatter vibra-tions can appear mysteriously in the middle of an other-wise stable cutting operation, even with no apparentchange in the cutting process parameters. Manyresearchers choose to ignore such behavior, simplychalking it up to inconsistencies in the workpiecematerial or inaccuracies in the machine tool. Recentobservations by NIST researchers indicate that a betterexplanation might be obtained by considering thenonlinear dynamics of the cutting process.

As part of NIST research into high-speed machining,a NIST scientist has been taking a critical look at theprediction of chatter stability in cutting processes. Itturns out that for nonlinear dynamical systems, thestability boundary can be characterized byjumpphenomena,or the coexistence of multiple dynamicstates known asattractors.In other words if the processwere nonlinear, it might be perfectly reasonable fora cutting process to produce both chatter free andviolently chattering tool motions for the same cuttingparameters. It may be that what machinists are observ-ing when they see a tool start vibrating for no apparentreason is simply an example of a nonlinear dynamicsphenomena known as a subcritical Hopf bifurcation,in which the process “jumps” from one attractor toanother.

To test this hypothesis, the NIST scientist undertook aseries of carefully performed experiments that led to anexperimental bifurcation diagram that suggests that thetransition between stable and unstable cutting on a latheis characterized by jump phenomena. The focus of thecurrent research is to develop a nonlinear dynamicsmodel that will accurately predict the behavior seen inthese experiments.

CONTACT: Jon Pratt, (301) 975-5470; [email protected].

NIST ANNOUNCES IPsec-WIT (IKE): AWEB-BASED IPsec/IKE (INTERNET KEYEXCHANGE) INTEROPERABILITY TESTSYSTEMNISTs web-based IPsec test system, IPsec-WIT, (http://ipsec-wit.antd.nist.gov) now supports use of IKE fornegotiating Security Associations (SAs), in addition tomanual SA establishment. New test suites are availablefor IKE-based testing. IKE test cases allow users toconfigure underlying IKE parameters and then conductinteroperability tests from key negotiation through IPsecdata transfer. The test system provides output anddiagnostics at various levels of detail (high-level scripttraces to individual packet dumps), either directlythrough the web interface or out-of-band throughe-mail.

For those interested in the IPsec-WIT system but notready to conduct real tests, the system supports testcases that allow it to negotiate with itself. IPsec-WITcontains an extensive tutorial on the testers operations aswell as pointers to documentation for NISTs IKE andIPsec reference implementations, PlutoPlus andCerberus. Documentation for PlutoPlus and Cerberus isavailable at http://ipsec-wit.antd.nist.gov/newipsecdoc/pluto.html and http://www.antd.nist.gov/cerberus.

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PlutoPlus, the IKE reference implementation (basedon the original Pluto), is in an early development state.Currently, it conducts only Phase 1 Main Mode/Phase 2Quick Mode negotiations authenticated with a pre-shared key. Once PlutoPlus has undergone sufficienttesting, the source code will be released to interestedparties in the United States and Canada only.

CONTACT: Sheila Frankel, (301) 975-3297; [email protected].

UNRIVALED CAPACITANCE STANDARDEXPERIMENT BASED ON COUNTINGELECTRONS DEBUTSNIST researchers have carried out a ground-breakingexperiment in which they implemented a new type ofcapacitance standard with a relative uncertainty of lessthan 10–6. The standard brings together for the first timetwo technologies developed at NIST. A device known asan electron pump, based on ultrasmall tunnel junctionsand operating at temperatures less than 0.1 K, passesand counts individual electrons with a relativeuncertainty of 10–8. The electrons flow onto a cryo-genic, vacuum-gap capacitor that has exceptionally lowleakage and frequency dependence because it does notcontain the dielectric materials that make ordinarycapacitors imperfect. After placing about 100 millionelectrons on the capacitor, the resulting voltage acrossthe capacitor is measured, and the capacitance is simplythe ratio of pumped charge to measured voltage:C = Q/V. Comparing the experimental standard withthe best commercial capacitance meter shows agree-ment well within the 2310–6 relative uncertainty of thecommercial instrument. With improvements to room-temperature electronics, a version of the new standard isexpected to reach a relative uncertainty of 10–7. Furthertests are planned in which the new type of standard willbe compared with NISTs calculable capacitor. If inthese tests the new standard performs over a range offrequencies with a relative uncertainty on the order of10–7 as expected, it potentially could provide the basisfor a significant improvement in NISTs calibrationservice for capacitance.

CONTACT: David Rudman, (303) 497-5081; [email protected].

NIST LEADS DEVELOPMENT OF NEW IECELECTRIC AND MAGNETIC FIELDINSTRUMENT/MEASUREMENT STANDARDUnder the leadership of a NIST scientist, WorkingGroup 11 of International Electrotechnical CommissionTechnical Committee (IEC) 85 has developed thenow-approved standard IEC 61786, “Low-frequency

magnetic and electric fields with regard to humanexposure—Special requirements for instruments andguidance for measurements.” The standard includesdescriptions of instrumentation for characterizingmagnetic and electric fields (15 Hz to 9 kHz), terminol-ogy, requisite instrument specifications and calibrationmethods, examples of measurement protocols, and acomprehensive listing of sources of measurementuncertainty. The new standard, also spearheaded by aNIST scientist, has its genesis in a standard of theInstitute of Electrical and Electronics Engineers (IEEE),in particular, the AC Fields Working Group in the IEEEPower Engineering Society. This standard, IEEE Std.1308-1994, Recommended Practice for Instrumenta-tion: Speci-fications for Magnetic Flux Density andElectric Field Strength Meters—10 Hz to 3 kHz,provided the basis when WG 11 began the processleading to the development of the standard in 1995.

The preparation of the IEC standard was prompted inpart by the January 1995 publication of a EuropeanCommittee for Electrotechnical Standardization(CENELEC) Prestandard, ENV 50166-1, “Human ex-posure to electromagnetic fields, Low-frequency (0 Hzto 10 kHz).” The CENELEC prestandard sets restric-tions on human exposure to magnetic and electric fieldsin the frequency range 0 Hz to 10 kHz and is intendedfor “provisional application” for 3 years. The usefulnessof the new IEC standard also should increase with therecent publication of revised magnetic and electric fieldexposure guidelines by the International Commission onNon-Ionizing Radiation Protection [Health Physics74, 494 (1998)]. The new IEC standard complementsthese exposure documents without endorsing the appro-priateness of their recommendations. Because the textof the draft document will indicate field meter specifica-tion requirements, as well as calibration and measure-ment methods, it is important that conflicts do notdevelop between the United States (IEEE) and interna-tional standards in these areas. As a member of the IEC,the United States is under some obligation to adopt therecommendations of IEC standards, which are volun-tary. There also are potential economic implications forU.S. manufacturers of instrumentation that wish to mar-ket their products in Europe.

CONTACT: James K. Olthoff, (301) 975-2403;[email protected].

NIST-LED FIRST INTERNATIONALSTANDARD FOR SUPERCONDUCTORSPUBLISHED BY IECThe first international standard on superconductivity hasbeen published by International Electrotechnical Com-mission (IEC) Technical Committee 90 (TC90). The

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document is IEC 61788-1 Superconductivity—Part1: Critical Current measurement—DC critical currentof Cu/Nb-Ti composite superconductors. NIST scien-tists initiated the first draft of this document and subse-quently addressed all comments and suggestionsreceived over the last 6 years on nine draft versions.TC90 incorporates eight working groups (WGs), eachassigned the task of creating a specific standard. Theprocess of standards development required circulation ofeach draft for comments and suggestions from the inter-national members of WG2 and the national committeesof each participating country. Each national committeehas a technical advisor (TA) and a technical advisorygroup (that provide input and cast votes at various stagesof the process.

With this first experience in IEC standards develop-ment as a guide, the members of TC90 are proceedingmore expeditiously with the development of twocompanion standards on critical-current measurementfor other superconductor materials. In addition, fiveother standards are in process in TC90.

CONTACT: Loren Goodrich, (303) 497-3143;[email protected].

INTERNATIONAL COMPARISON OFNOISE-TEMPERATURE MEASUREMENTSCOMPLETEDNIST staff have completed their assignment for a pilotlaboratory on an international comparison of thermalnoise measurements, conducted under the auspices ofthe International Committee on Weights and Measures/Consultative Committee on Electricity (now Consulta-tive Committee on Electricity and Magnetism). Thecomparison is identified as GTRF-92-2. The noisetemperatures of two commercial solid-state noisesources having GPC-7 connectors were measured at2 GHz, 4 GHz, and 12 GHz at the national measurementlaboratories in France (Laboratoire Central desIndustries Electriques), Germany (Physikalisch-Technische Bundesanstalt), the United Kingdom(National Physical Laboratory), and the United States.Good agreement was found among the results from thedifferent laboratories, with all results agreeing withinthe relative expanded uncertainties, which ranged from0.5 % to 2.9 %. The comparison was performed inaccordance with the guidelines recently adopted by theConsultative Committee and served as a test vehicle toevaluate these guidelines. A paper reporting the results,authored by representatives from each participatinglaboratory, was presented at the Conference onPrecision Electromagnetic Measurements, held in Wash-ington, D.C., earlier this summer. Accurate knowledgeof noise is important, because the presence

of noise limits the information capacity of a communi-cation channel.

CONTACT: Robert M. Judish, (303) 497-3380;[email protected].

NIST UNVEILS NEW WORKING STANDARDFOR LOW HUMIDITY LEVELSThe fabrication of semiconductors requires the use ofhigh purity gases with very low water content. Given itsubiquity, contamination by water vapor is difficult toavoid and can be assessed only by measurement of thewater content of the process gases used. Failure tomaintain high purity (less than 100 nmol of water vaporper mol of bulk gas) can degrade seriously the overallefficiency of many processes related to semiconductormanufacturing, resulting in decreased yield and in-creased cost, and limiting ultimate product perfor-mance. Consequently, manufacturers install ultra-sensi-tive hygrometers in an attempt to measure trace amountsof water vapor in their process gases. To ensure thatthese measurements are reliable, this instrumentationmust be periodically calibrated against humiditystandards.

Unfortunately, humidity calibration at nmol/mollevels of water vapor is not straightforward. The mostcommon approach is to use humidity generationschemes based on use of “dry” gases, addition of a“known quantity” of water vapor (via a permeationdevice), and multi-stage dilution. This approach,although widespread, is far from ideal. The dryness ofthe gas is difficult to ensure, and uncertainties associ-ated with measurement of gas flow rates and water-vapor permeation rates can lead to irreproducibility andsignificant error.

To address this problem, NIST researchers havedeveloped a high-precision humidity calibration system,based on the physical properties of water. The newdevice, known as the Low Frost-Point HumidityGenerator (LFPG) sidesteps uncertainties associatedwith the “dry gas” and flow-mixing stages used inconventional systems. Rather than mixing water vaporwith dry gas, the LFPG produces accurately knownwater vapor/gas mixtures by flowing the carrier gas overa surface of pure ice maintained at an accurately known,fixed temperature between –58C and –101.68C. Theresulting water content of the equilibrated gas/watermixture exiting the LFPG is dependent only upon thevapor pressure of ice (a temperature-dependent thermo-dynamic property) and system pressure. Unlike flow-based systems, the output of the LFPG is independent ofthe gas flow rate.

Variation of the LFPG temperature over its entireoperating range yields humidity levels spanning six

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decades in water concentration. By tightly controllingthe system temperature to within 0.0028C, NISTresearchers can produce humidity levels with a relativeuncertainty of better than 0.04 %. NIST calibrationservices for trace moisture level hygrometers andhumidity generators, using test gas supplied by theLFPG, will commence in early 1999.

CONTACT: Joseph Hodges, (301) 975-2605;[email protected] or Gregory Scace, (301) 975-2626; [email protected].

NIST HOLDS WORKSHOP ON DESIGNGUIDELINES FOR FIBER-REINFORCEDPOLYMER COMPOSITE STRUCTURESAt a workshop hosted by NIST, fiber-reinforcedpolymer (FRP) composite manufacturers and their rawmaterial suppliers were invited to discuss and makerecommendations for an FRP design code for civilengineering applications. In recent years, interest in theuse of FRP composites for infrastructural and offshoreapplications has increased substantially. However, thelack of performance data as well as the absence ofdesign specifications or codes for these materials hashindered greatly their acceptance by civil engineers.

A plan proposing the use of load and resistance factordesign (LRFD) principles as a basis for a design codewas presented and discussed extensively. NISTresearchers presented overviews of NIST’s capabilitiesand potential contributions to an LRFD-based designcode. Ongoing efforts in the development of a designcode for FRP materials also were reported on byrepresentatives of the American Society of CivilEngineers (ASCE), which has assisted in implementingLRFD-based design codes for both steel and timberconstruction materials. Issues cited as critical to thiseffort include long-term durability, fire performance,and industry-wide standardization of FRP components.

A total of 20 participants from a variety of organiza-tions attended the meeting. Plans are currently underway for a follow-up meeting in which plans for estab-lishing a government/industry consortium will beformalized.

CONTACT: Joannie W. Chin, (301) 975-6815;[email protected].

WORKSHOP ON PROPERTIES ANDAPPLICATIONS OF DENDRITIC POLYMERSLack of knowledge about the properties of dendriticpolymers at interfaces was identified at a recent NISTworkshop as a critical barrier to full exploitation ofthese unique polymers. Other needs identified by theattendees included direct comparisons of structures of

dendritic polymers and characterization of interactionswith other polymers. Dendrimers, which are highlybranched and precisely constructed polymers, representnew macro-molecular structures that have attractedattention in the scientific community for several yearsand have recently moved into production and applica-tion. The workshop, held in July 1998, sought to definethe future research directions that would advanceapplications of these materials.

Results of the workshop will be used to plan futuredirections of the research. The 70 participantsrepresented all of the companies manufacturingdendrimers, as well as most of the companies usingdendritic polymers in products and the leading academiclaboratories in the field. For true dendrimers currentproducts include agents for gene transfection andimmunoassays. Promising applications also weredescribed in drug delivery, radiation therapy, imagingenhancement, coatings, and chemical sensors. Othermaterials applications for dendritic polymers that havedemonstrated economic feasibility include productionof nanoporous low dielectric materials, additives forcoloring polyolefins, and polymer processing or tough-ening aids. It also was shown at the workshop that somepolyolefin polymers synthesized from metallocenecatalysis owe their properties to dendritic branching.This information will help NIST direct its researchefforts to benefit a wide range of important applica-tions.

CONTACT: Barry Bauer, (301) 975-6849; [email protected] or Eric Amis, (301) 975-6681; [email protected].

WORKSHOP HELD ON FILLED POLYMERSAND NANOCOMPOSITESControl of molecular-level interactions and measure-ment of polymer dynamics at the filler interface wereidentified by participants at a recent NIST sponsoredworkshop as the most critical issues in filled polymersand nanocomposites. Although filled polymers alreadyrepresent a substantial fraction of polymer materials,recent developments in nanocomposites have attractedrenewed interest in developing the science and technol-ogy base to optimize performance.

The workshop, held in June 1998, focused on identi-fying the most critical issues hindering improvements inapplications of filled polymers and nanocomposites. Ofthe 75 external participants, 50 were from industry,mostly experts in the area of filled polymer technology.Through lively discussions, the workshop participantshighlighted and prioritized a range of future researchand measurement needs for filled materials. The discus-sions also laid the foundation for future research in this

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area, and collaborations between NIST, industry andacademia. The results of the workshop will be used toplan future directions of NIST work.

CONTACT: Alamgir Karim, (301) 975-6588;[email protected] or Eric Amis, (301) 975-6681;[email protected].

ARTIFACT METROLOGY FOR DEPARTMENTOF ENERGYEngineers at Los Alamos National Laboratory are pio-neering the use of a glass hyper-hemisphere (208 pastthe Equator) as a reference artifact for the shellmeasurement machines used throughout the nuclearweapons complex and turned to NIST for assistance inoptical measurement of the figure of this artifact. ANIST scientist presented an analysis at Los Alamos ofinterferometric measurement methods showing that allthe relevant features—internal and external radii, wallthickness, wall thickness variation, and “pole height”—can be obtained optically. Optically obtained measure-ments provide a measurement entirely independent ofthe mechanical (coordinate measuring machine or spe-cial-purpose measuring machine) methods currentlyused. The first artifact is in production at Los Alamosand measurements are expected to be made on thisartifact in 1999.

CONTACT: Chris Evans, (301) 975-3484; [email protected].

Standard Reference Materials

COPLANAR WAVEGUIDE VERIFICATIONSETS ARE NOW REFERENCE MATERIALSCoplanar waveguide verification sets fabricated at NISThave become one of the agency’s newest high-frequencyreference material sets. Known as NIST RM 8130, theinitial set of 25 reference wafers contains NIST-charac-terized microwave circuitry that can be used to measurethe drift of microwave on-wafer probing stations andverify that the instrumentation is capable of repeatingNIST measurements. It also makes it possible to testthe integrity of the test instrumentation and setup. Forexample, the test procedure is designed to identifyunsound connections and other common instrumentproblems.

Developed with the help of the NIST MonolithicMicrowave Integrated Circuit Consortium, the verif-ication set costs about $3,600. The 25 reference

materials in the initial batch have been tested individu-ally.

For technical information, contact Dylan Williams,MC 813.01, NIST, Boulder, Colo. 80303-3337, (303)497-3138, [email protected]. To order RM 8130,contact the Standard Reference Materials Program,Building 202, Room 204, NIST, Gaithersburg, MD20899-0001, (301) 975-6776, fax: (301) 948-3730,[email protected].

Media Contact: Collier Smith (Boulder), (303) 497-3198; [email protected].

NIST SILICON RESISTIVITY STANDARDSIN DEMAND BY INDUSTRYSemiconductor industry need for new silicon resistivityStandard Reference Materials has been demonstratedthrough the sales of some 200 units of these standards.They were first put into stock in late 1997 when NISTannounced the availability of an improved set of SRMs,superseding the earlier silicon resistivity SRM sets.Resistivity is the most important materials parameterto be specified for silicon starting materials. Nominalresistivity values of the new SRMs range from0.01V cm to 200V cm; the wafer diameter is 100 mm.In response to industry needs, these SRMs provideimproved uniformity and substantially reduced uncer-tainty of certified values as a result of both material andprocedural improvements. In particular, the certifica-tion is based on a dual-configuration four-probemeasurement procedure in contrast to the single-config-uration measurements used in the earlier resistivitySRMs. Extensive testing has shown that the dual-configuration procedure reduces random variation ofmeasurements and probe-to-probe differences. Indi-vidual data for each wafer are supplied on the SRMcertificate. Technical insights presented by the rigorouscertification process are available in NIST SpecialPublication 260-131, Standard Reference Materials:The certification of 100 mm diameter silicon resistivitySRMs 2541 through 2547 using dual-configurationfour-point probe measurements.

CONTACT: David G. Seiler, (301) 975-2054; [email protected].

SRM STANDARD BULLETSThe 1998 AFTE (Association of Firearm and Tool MarkExaminers, 98-AFTE) conference was held in Tampa,Fla., July 1998. Approximately 300 people from about15 countries attended this conference, the 29th AFTEannual meeting since 1969. More than 30 speakerspresented talks regarding bullets and casings examina-tions and crime solving.

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In 1997, the Alcohol, Tobacco, and Firearms (ATF)bureau approached NIST about creating a standardbullet and casing that could be used for training newoperators and for testing the performance of theirmachines. NIST agreed to start a new project forStandard Reference Material (SRM) standard bulletsand casings. In April 1998, two NIST prototypestandard bullets, based on a numerically controlleddiamond turning process used for producing the NISTrandom profile roughness specimens, were delivered tothe ATF for testing.

In the 98-AFTE, the NIST prototype standard bulletwas measured by a newly developed DRUGFIRE 3-DRotoscan System for bullets and casings measurements.Measuring results on the new system showed highagreement with that measured at the NIST microformcalibration system. Instrument makers and bullet exam-iners also provided comments and suggestions regardingthe improvements on the design, testing, and use of thestandard bullets and casings. Based on these comments,a new version of the NIST standard bullets will be putinto production and testing. A new proposal will be usedfor developing some standard bullets with twisted bulletsignatures. NIST prototype standard casings also will bedeveloped shortly.

CONTACT: Junfeng Song, (301) 975-3799; [email protected].

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Volume 102, Number 6

Journal of Research of the

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U.S. Department of Commerce

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The International System of Units (SI)The Modern Metric System

Uncertain about the InternationalSystem of Units (universally abbreviatedSI), the modern metric system usedthroughout the world? Do you need toknow the proper way to express the resultsof measurements and the values of quanti-ties in units of the SI? Do you need to knowthe NIST policy on the use of the SI? Thenyou need the 1995 edition of the NationalInstitute of Standards and TechnologySpecial Publication 811,Guide for the Useof the International System of Units (SI).

The 1995 edition of the National Institute of Standards and Technology Special Publication 811,Guide for the Use of the International System of Units (SI), by Barry N. Taylor, is now available.

The 1995 edition of SP 811 corrects a number of misprints in the 1991 edition, incorporates asignificant amount of additional material intended to answer frequently asked questions concerningthe SI and SI usage, and updates the bibliography. The added material includes a check list forreviewing the consistency of written documents with the SI. Some changes in format have alsobeen made in an attempt to improve the ease of use of SP 811.

The topics covered by SP 811 include:• NIST policy on the use of the SI in NIST publications.• Classes of SI units, those SI derived units that have special names and symbols, and the SI

prefixes that are used to form decimal multiples and submultiples of SI units.• Those units outside the SI that may be used with the SI and those that may not.• Rules and style conventions for printing and using quantity symbols, unit symbols, and prefix

symbols, and for spelling unit names.• Rules and style conventions for expressing the results of measurements and the values of quan-

tities.• Definitions of the SI base units.• Conversion factors for converting values of quantities expressed in units that are mainly unac-

ceptable for use with the SI to values expressed mainly in units of the SI.• Rounding numbers and rounding converted numerical values of quantities.

Single copies of the 84-page SP 811 may be obtained from the NIST Calibration Program,Building 820, Room 232, Gaithersburg, MD 20899-0001, telephone: 301-975-2002, fax:301-948-3825.

Special Publication 811

1995 Edition

Guide for the Use of the International

System of Units (SI)

Barry N. Taylor

United States Department of Commerce

Technology Administration

National Institute of Standards and Technology

NISTTechnical PublicationsPeriodical

Journal of Research of the National Institute of Standards and Technology—Reports NIST researchand development in those disciplines of the physical and engineering sciences in which the Institute isactive. These include physics, chemistry, engineering, mathematics, and computer sciences. Papers cover abroad range of subjects, with major emphasis on measurement methodology and thebasic technologyunderlying standardization. Also included from time to time are survey articles on topics closely related tothe Institute’s technical and scientific programs. Issued six times a year.

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Monographs—Major contributions to the technical literature on various subjects related to theInstitute’s scientific and technical activities.Handbooks—Recommended codes of engineering and industrial practice (including safety codes) devel-oped in cooperation with interested industries, professional organizations, and regulatory bodies.Special Publications—Include proceedings of conferences sponsored by NIST, NIST annual reports, andother special publications appropriate to this grouping such as wall charts, pocket cards, and bibliographies.

National Standard Reference Data Series—Provides quantitative data on the physical and chemicalproperties of materials, compiled from the world’s literature and critically evaluated. Developed under aworldwide program coordinated by NIST under the authority of the National Standard Data Act (PublicLaw 90-396). NOTE: The Journal of Physical and Chemical Reference Data (JPCRD) is publishedbimonthly for NIST by the American Chemical Society (ACS) and the American Institute of Physics (AIP).Subscriptions, reprints, and supplements are available from ACS, 1155 Sixteenth St., NW, Washington, DC20056.Building Science Series—Disseminates technical information developed at the Institute on buildingmaterials, components, systems, and whole structures. The series presents research results, test methods, andperformance criteria related to the structural and environmental functions and the durability and safetycharacteristics of building elements and systems.Technical Notes—Studies or reports which are complete in themselves but restrictive in their treatment ofa subject. Analogous to monographs but not so comprehensive in scope or definitive in treatment of thesubject area. Often serve as a vehicle for final reports of work performed at NIST under the sponsorship ofother government agencies.Voluntary Product Standards—Developed under procedures published by the Department of Commercein Part 10, Title 15, of the Code of Federal Regulations. The standards establish nationally recognizedrequirements for products, and provide all concerned interests with a basis for common understanding ofthe characteristics of the products. NIST administers this program in support of the efforts of private-sectorstandardizing organizations.

Order thefollowing NIST publications—FIPS and NISTIRs—from the National Technical InformationService, Springfield, VA 22161.Federal Information Processing Standards Publications (FIPS PUB)—Publications in this seriescollectively constitute the Federal Information Processing Standards Register. The Register serves as theofficial source of information in the Federal Government regarding standards issued by NIST pursuant tothe Federal Property and Administrative Services Act of 1949 as amended, Public Law 89-306 (79 Stat.1127), and as implemented by Executive Order 11717 (38 FR 12315, dated May 11, 1973) and Part 6 ofTitle 15 CFR (Code of Federal Regulations).NIST Interagency Reports (NISTIR)—A special series of interim or final reports on work performed byNIST for outside sponsors (both government and nongovernment). In general, initial distribution is handledby the sponsor; public distribution is by the National Technical Information Service, Springfield, VA 22161,in paper copy or microfiche form.

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