Radiation thermometry at NIST: An update of services and research activities

An overview of activities at the National Institute of Standards and Terminology (NIST) in radiation thermometry and related temperature scale research is presented. An expansion of calibration services for pyrometers will be described as well as efforts to develop calibration services for blackbody simulators. Research relevant to the realization of the new international temperature scale (ITS 90) will be discussed

Dynamic response for thermal control and measurement and fast radiation thermometry

A preliminary evaluation was made by ORNL of a two-color ratio pyrometer (TCRP) for temperature control in the Modular Electromagnetic Levitation (MEL) experiment. A discussion was presented by Eric Spjut at the 1987 NASA Non-Contact Temperature Measurement Workshop (NASA Conf. Publ. 2503, pp. 182-213) in which he described the non-linear characteristics of the time response of TCPs. Researchers replicated his model and results and note that the non-linear response behavior is minimized for small temperature steps at high temperatures. They then used the predicted response in a model for a proportional or integral feedback controller and predicted the control characteristics for heating and cooling a 5-mm diameter sphere of niobium at high (1500 to 2750 K) temperatures. The analysis shows that for a slow (25-ms) time response for a commercial RCRP, overshoots of several hundred kelvins will result from a 100-K decrease in the setpoint, and temperature tracking errors of 14 to 45 K will occur for control temperature ramps of 1000K/s. For a fast (greater than 0.1 ms) time response, the overshoot and ramp response errors are largely eliminated

Ultrasonic Measurement of Formability in Thin Ferritic Steel Sheet

The formability of rolled sheet metal is strongly influenced by the texture of the polycrystalline metal. For steel sheet, it is desirable to have high drawability to make automobile body parts, etc. In addition, material homogeneity is desired; that is, material cut from different parts of a rolled sheet should have the same plastic deformation when subjected to deep drawing

Ignition characteristics of the nickel-based alloy UNS N07718 in pressurized oxygen

The development of ignition and combustion in pressurized oxygen atmospheres was studied for the nickel based alloy UNS N07718. Ignition of the alloy was achieved by heating the top. It was found that the alloy would autoheat to destruction from temperatures below the solidus temperature. In addition, endothermic events occurred as the alloy was heated, many at reproducible temperatures. Many endothermic events occurred prior to abrupt increases in surface temperature and appeared to accelerate the rate of increase in specimen temperature. It appeared that the source of some endotherms may increase the oxidation rate of the alloy. Ignition parameters are defined and the temperatures at which these parameters occur are given for the oxygen pressure range of 1.72 to 13.8 MPa (250 to 2000 psia)

Ada/POSIX binding: A focused Ada investigation

NASA is seeking an operating system interface definition (OSID) for the Space Station Program (SSP) in order to take advantage of the commercial off-the-shelf (COTS) products available today and the many that are expected in the future. NASA would also like to avoid the reliance on any one source for operating systems, information system, communication system, or instruction set architecture. The use of the Portable Operating System Interface for Computer Environments (POSIX) is examined as a possible solution to this problem. Since Ada is already the language of choice for SSP, the question of an Ada/POSIX binding is addressed. The intent of the binding is to provide access to the POSIX standard operation system (OS) interface and environment, by which application portability of Ada applications will be supported at the source code level. A guiding principle of Ada/POSIX binding development is a clear conformance of the Ada interface with the functional definition of POSIX. The interface is intended to be used by both application developers and system implementors. The objective is to provide a standard that allows a strictly conforming application source program that can be compiled to execute on any conforming implementation. Special emphasis is placed on first providing those functions and facilities that are needed in a wide variety of commercial application

Subarctic climate for the earliest Homo sapiens in Europe

Acknowledgments The re-excavation of Bacho Kiro Cave was jointly conducted by the National Institute of Archaeology with Museum, Bulgarian Academy of Sciences, Sofia and the Department of Human Evolution at the MPI-EVA. We would like to thank the National Museum of Natural History (Sofia), the Archaeology Department at the New Bulgarian University (Sofia), the Regional Museum of History in Gabrovo, and the History Museum in Dryanovo for assistance on this project and the opportunity to study the Bacho Kiro Cave faunal material. We would like to thank M. Trost, S. Hesse, M. Kaniecki, and P. Dittmann (MPI-EVA) for technical assistance during stable isotope sample preparation. S. Steinbrenner is thanked for technical assistance with TC/EA-IRMS maintenance. Thanks are also due to H. Temming and U. Schwarz (MPI-EVA) for the production of microCT scans and replicas of the sample materials. We would also like to acknowledge the assistance of to D. Veres with taking OSL samples. Last but not least we would like to thank the handling editor, S. Ortman, as well as three anonymous reviewers for their thoughtful comments that greatly improved this manuscript. Funding: The field work was financed by the Max Planck Society. The stable isotope work was funded by the Max Planck Society as part of S.P.’s doctoral project. S.P. was supported by the Max Planck Society and the University of Aberdeen. K.B. was supported by a Philip Leverhulme Prize from The Leverhulme Trust (PLP-2019-284). N.B.’s work was supported as part of a grant by the German Research Foundation (“PALÄODIET” Project 378496604). V.A. was supported by a grant from the Foundation for Science and Technology, Portugal (IF/01157/2015/CP1308/CT0002). Author contributions: The study was devised by S.P., K.B., S.P.M., J.-J.H., and T.T. Archaeological excavation was undertaken by N.S. and T.T. in collaboration with Z.R. and S.P.M. who all contributed contextual information. V.A. collected sedimentological data at the site and untertook micromorphological investigations that provided information on site formation for this study. Zooarchaeological and paleontological analyses were performed by G.M.S. and R.S. OSL dating was carried out by T.L. Radiocarbon dating and recalibration of radiocarbon dates were conducted by H.F. MC-ICPMS analysis was conducted by N.B. and S.P. Sampling, sample processing for oxygen and strontium stable isotope analysis, and TC/EA-IRMS analysis were carried out by S.P. Code and data analyses were written and conducted by S.P. N.-H.T. consulted on statistical analysis and coding. S.P. wrote the paper with input from all authors. Competing interests: The authors declare that they have no competing interests. Data and materials availability: All data needed to evaluate the conclusions in the paper are present in the paper and/or the Supplementary Materials.Peer reviewedPublisher PD

Ignition characteristics of the iron-based alloy UNS S66286 in pressurized oxygen

The development of ignition and combustion in pressurized oxygen atmospheres was studied for the iron based alloy UNS S66286. Ignition of the alloy was achieved by heating the top surface of a cylindrical specimen with a continuous-wave CO2 laser. Two heating procedures were used. In the first, laser power was adjusted to maintain an approximately linear increase in surface temperature. In the second, laser power was periodically increased until autoheating (self-heating) was established. It was found that the alloy would autoheat to destruction from temperatures below the solidus temperature. In addition endothermic events occurred as the alloy was heated, many at reproducible temperatures. Many endothermic events occurred prior to abrupt increases in surface temperature and appeared to accelerate the rate of increase in specimen temperature to rates greater than what would be expected from increased temperature alone. It is suggested that the source of these endotherms may increase the oxidation rate of the alloy. Ignition parameters are defined and the temperatures at which these parameters occur are given for the oxygen pressure range of 1.72 to 13.8 MPa (25 to 2000 psia)

Application of Monte Carlo Simulations to Critical Dimension Metrology in a Scanning Electron Microscope

The state of the art in Monte Carlo simulations of scanning electron microscope (SEM) signals is reviewed. Two Monte Carlo computer codes were written to simulate the transmitted-, backscattered-, and secondary-electron signals from targets in a scanning electron microscope. The first, MONSEL-11, is applied to semi-infinite lines produced lithographically on multi-layer substrates. The second, MONSEL-111, is an extension to fully three-dimensional targets. Results for a 1 μm step, etched in a silicon substrate are compared with experimental data. The comparisons show that it is possible to obtain edge locations to an uncertainty of less than 10 nm. Simulations were performed for photoresist lines on a silicon substrate coated with a layer of photoresist. Techniques were derived for simulating signals for finite beam diameter from those for zero beam diameter, and for extracting signals approximating zero beam diameter from those with finite beam diameter. Approaches were formulated for efficient use of the Monte Carlo codes