NIST Digital Archives
Not a member yet
149436 research outputs found
Sort by
Rolf L. Ziesler
No full textROLF L. ZEISLER
NBS/NIST: 1978–1991 and 1996–2009
INDUCTED: 2018
B: 1941, Weissenfels, Germany
D: 2017, Denver, Colorado
EDUCATION:
Institute for Radiochemistry, Technical University Munich,
Dipl. (Chemistry), 1970
Institute for Radiochemistry, Technical University Munich,
PhD (Chemistry), 1974
CITATION: For world leadership in development and implementation of nuclear methods in biosciences, environment studies, and promotion of SRMs at the highest level of metrological science.
POSITIONS HELD AT NBS/NIST:
Research Chemist, Activation Analysis Group, Inorganic Analytical Research Division, Center for
Analytical Chemistry (CAC), National Measurement Laboratory (NML), 1978-1991
Leader, Activation Analysis Group, Inorganic Analytical Research Division, CAC/NML, 1979-1985
Project Manager, Inorganic Analytical, U.S. National Environmental Specimen Bank, CAC/NML, 1979-1990
Research Chemist, Analytical Chemistry Division, Chemical Science and Technology Laboratory, 1996-2009
Scientist Emeritus, Chemical Sciences Division, Material Measurement Laboratory, 2009-2017
HONORS:
Commemorative Medal of Charles University, Prague, Czech Republic (1993)
NIST Analytical Chemistry Division Chemical Metrology Award (2007)
American Nuclear Society Radiation Science and Technology Award (2009)
George Hevesy Medal Award (2018)
MEMBERSHIPS:
American Nuclear Society, Chair of Biology & Medicine and Isotopes & Radiation Divisions
AOAC International (formerly Association of Official Analytical Chemists)
International Committee on Activation Analysis – Modern Trends in Activation Analysis
International Advisory Committee of the Radiochemical Congress
Editorial Advisory Board, Journal of Radioanalytical and Nuclear Chemistry
PUBLICATIONS:
More than 250 publications including:
Wise, S.A. and Zeisler, R., "The Pilot Environmental Specimen Bank Program", Environ. Sci. Technol., 18:302A-307A (1984)
Zeisler, R., et al., "Sol Particle Immunoassays Using Colloidal Gold and Neutron Activation", J. Radioanal. Nucl. Chem., 167:445-452 (1993)
Zeisler, R., "Reference Materials for Small-Sample Analysis", Fresenius J. Anal. Chem., 360:376-379 (1998)
Zeisler, R., Lindstrom, R.M., and Greenberg, R.R. "Instrumental Neutron Activation Analysis, A Valuable
Link in Chemical Metrology", J. Radioanal. Nucl. Chem., 263:315-319 (2005)
Zeisler, R., et al., "Use of Neutron Activation Analysis for the Characterization of Single-Wall Carbon Nanotube Materials", J. Radioanal. Nucl. Chem., 291:561-567 (2012)
Yu, L.L., Wei, C., Zeisler, R., et al., "An Approach for Identification and Determination of Arsenic Species in the Extract of Kelp", Anal. Bioanal. Chem., 407:3517–3524 (2015
What is The SI? A Proposal for an Educational Adjunct to the Redefinition of the International System of Units
No full textWe discuss how the impending redefinition of the SI system of units might affect the ability of students to understand the link between the units and the new system. The redefinition will no longer define a set of base units, but rather a set of constants of nature, such as the elementary charge, e. We point out that this list of constants need not be the only way to introduce students to the subject, either in class or in textbooks. We suggest an alternative way to introduce high school and undergraduate students to the redefined SI, by suggesting a list of experiments for some units; this list would be completely compatible with the redefined SI, and would have all of the same scientific and technological advantages. We demonstrate by questionnaire results that this alternative is more appealing to students. We hope to spur a discussion amongst teachers regarding this important topic for high school and undergraduate physics courses
Correlation of Neutron-Based Strain Imaging and Mechanical Behavior of Armor Steel Welds Produced with the Hybrid Laser Arc Welding Process
No full textBragg edge neutron transmission imaging was used to characterize the spatial distribution of thermally induced residual strains in a steel armor plate welded with a hybrid laser arc process. This residual strain distribution was compared to the spatial development of mechanical strain during uniaxial deformation. By correlating the strain measurements of both methods, the failure mechanism was determined in armor welds joined with this process. Weld failure consistently occurred in the subcritical heat-affected zone where mechanical strain accumulation in softened martensitic parent material was superimposed upon the weld region containing the highest residual thermally induced strain
A Software Assurance Reference Dataset: Thousands of Programs With Known Bugs
No full textThe Software Assurance Reference Dataset (SARD) [1] is a growing collection of over 170 000 programs with precisely located bugs. The programs are in C, C++, Java1, PHP, and C# and cover more than 150 classes of weaknesses, such as SQL injection, cross-site scripting (XSS), buffer overfow, and use of a broken cryptographic algorithm. Most are automatically generated synthetic programs, each a few pages of code long, but there are also over 7000 full-sized applications. In addition, SARD has production code and has hundreds of cases written by hand. The code is typical quality. It is neither pristine nor obfuscated. Many cases have corresponding “good” cases, in which weaknesses are fxed, to test for false positives.
The SARD web interface allows users to browse test cases and test suites or search for test cases by programming language, weakness type, fle name, size, words in the description, and several other criteria. The user can select and download any or all of the resulting cases
Math as art?
No full textNow, this is a TRUE example of STEAM (Science-Technology-Engineering-Art-Mathematics)! Created by NIST mathematician Hari Iyer, this computer-generated art is the result of tracing out undulating mathematical functions known as sines and cosines. But Hari’s work isn’t just about making something pretty. Mathematicians can combine sines and cosines to help model actual surfaces that can then be used to engineer shapes for objects such as car parts. Not that you’ll be seeing this particular sine-cosine pattern resulting in a car part any time soon
Oral history interview of ITL/Cybersecurity: Dennis Branstad, Miles Smid, Stuart Katzke, February 7, 2018 / [persons present]: William (Bill) Gadzuk, Donna Dodson, Roger Martin, Shelly Wiederhorn, Cita Furlani, Kurt Barker, and Ed Robak
No full textITL Oral history interview of Dennis Branstad, Miles Smid, and Stuart Katzke all of whom were principle players in the establishment and implementation of the NBS/NIST program in data encryption and cybersecurity
FEASST: Free Energy and Advanced Sampling Simulation Toolkit
No full textThe Free Energy and Advanced Sampling Simulation Toolkit (FEASST) is a free, open-source, modular program to conduct molecular and particle-based simulations with Metropolis, Wang-Landau and Transition-Matrix Monte Carlo methods [1–7]. FEASST is implemented in C++ and may be imported as a module within Python 2 or 3.1
This document describes the initial public release version 1.0 with the following features:
1. Simulation techniques
• Wang-Landau Monte Carlo
• Transition-matrix Monte Carlo
• Metropolis Monte Carlo
2. Thermodynamic ensembles
• Grand canonical ensemble
• Isothermal isobaric ensemble
• Canonical ensemble
3. Advanced Monte Carlo algorithms
• Parallel confguration swap
DNA barcode illustration
No full textEver since the human genome was declared officially sequenced in 2003, scientist, doctors and the general public have been excited about what it could mean for medicine. At the center of the excitement is CRISPR, a genome-editing technique that shows great potential for allowing doctors to “clip out” disease-causing genetic mutations. Last spring, researchers at the Joint Initiative for Metrology in Biology (JIMB, a collaboration between Stanford University and NIST) developed a new CRISPR platform called MAGESTIC. In the words of NIST science writer Alison Gillespie, “… the new platform makes CRISPR less like a blunt cutting tool and more like a word processor by enabling an efficient ‘search and replace’ function for genetic material.” Read more about MAGESTIC at https://www.nist.gov/news-events/news/2018/05/clipping-scissors-word-processo
Transient Thermal Response of a Guarded-Hot-Plate Apparatus for Operation Over an Extended Temperature Range
No full textA mathematical model is presented for a new-generation guarded-hot-plate apparatus to measure the thermal conductivity of insulation materials. This apparatus will be used to provide standard reference materials for greater ranges of temperature and pressure than have been previously available. The apparatus requires precise control of 16 interacting heated components to achieve the steady temperature and one-dimensional heat-transfer conditions specified in standardized test methods. Achieving these criteria requires deriving gain settings for the 16 proportional-integral-derivative (PID) controllers, comprising potentially 48 parameters. Traditional tuning procedures based on trial-and-error operation of the actual apparatus impose unacceptably lengthy test times and expense. A primary objective of the present investigation is to describe and confirm the incremental control algorithm for this application and determine satisfactory gain settings using a mathematical model that simulates in seconds test runs that would require days to complete using the apparatus. The first of two steps to achieve precise temperature control is to create and validate a model that accounts for heating rates in the various components and interactions with their surroundings. The next step is to simulate dynamic performance and control with the model and determine settings for the PID controllers. A key criterion in deriving the model is to account for effects that significantly impact thermal conductivity measurements while maintaining a tractable model that meets the simulation time constraint. The mathematical model presented here demonstrates how an intricate apparatus can be represented by many interconnected aggregatedcapacity masses to depict overall thermal response for control simulations. The major assemblies are the hot plate with four subcomponents, two cold plates with three subcomponents each, and two edge guards with three subcomponents each. Using symmetry about the hot plate, the number of components in the simulation model is reduced to 12 or 15, depending on the mode of operation for the apparatus. Configurations of the main components with embedded heating elements were carefully designed earlier using detailed finite-element analyses to give essentially isothermal surfaces and one-dimensional heat flow through test specimens. It is not tractable, or perhaps justified, to extend these prior analyses to simulate the controlled transient responses of the apparatus. The earlier design criterion does, however, support the aggregated-capacity simplification implemented in the present thermal model. The governing equations follow from dynamic energy balances on components with controlled heating elements and additional intermediate ("floating")components. Thermal bridges comprise conduction paths, with and without surface convection and radiation, between components and fixed-temperature "heat sinks." An implicit finite-difference numerical method was used to solve the resulting system of first-order differential equations. The mathematical model was initially validated using measurement data from test runs where a step change in heating rate was applied to single elements in turn, and component temperatures were recorded up to a nearly steady condition. Thermocouples and standard platinum resistance thermometers were used to measure temperatures, and thermopiles were used to measure temperature differences. Next, extensive simulations were conducted with the mathematical model to estimate suitable gain settings for the various controllers. The criteria were tight temperature control after reaching set points and acceptable times to achieve quasi-steady-state operation. Comparisons between measurements and predicted temperatures for heated components are presented. The results show that the model incorporating the above simplifying approximations is satisfactory for components comprising the hot-plate and cold-plate assemblies. For the edge guards, however, the conventional aggregated-capacity criteria are not as fully satisfied because of their configuration. Temperature variations in the edge guards, fortunately, have a lesser effect on the accuracy of the thermal conductivity measurements. Therefore, the thermal response model is deemed satisfactory for simulating PID feedback to investigate "closed-loop" control of the apparatus, thus meeting the primary objective
NISTfit: A Natively Multithreaded C++11 Framework for Model Development
No full textThe current trend in computer architecture is for increasingly parallel computation while the clock frequency stagnates. The increase in computing speed is achieved by dividing a process into several threads which are executed in parallel on multiple processors, processors with multiple cores, cores that are able to handle multiple threads (hyper-threading), graphical processing units (GPU), or co-processors. In order to take advantage of these new architectures, algorithms that have historically been implemented for serial evaluation need to be refactored for parallelization. In this work, a native multithreading framework in C++11 for scientifc and engineering model development is presented