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Oral History interview of Tom Lucatorto, July 13, 2023 (Transcript)
No full textThomas B. Lucatorto, an associate guest researcher in the Surface and Interface Metrology group of the Sensor Science division, NIST Physical Measurement Laboratory, reflects on his 51 ½ year career at NIST including his decision to join the National Bureau of Standards, his work with the Synchrotron Ultraviolet Radiation Facility (SURF), the Laser Interferometric Gravity-wave Observatory (LIGO), and with EUV lithography. A written postscript from Thomas Lucatorto, dated September 14, 2023, is included at the end of the transcript.
Thomas Lucatorto received a Ph.D. in physics from Columbia University in 1968. He was a postdoctoral research associate at Columbia University from 1968 to 1970, conducting research involving radiofrequency spectroscopy of atoms and ions. He joined the National Bureau of Standards in 1970 to investigate atomic structure using laser and synchrotron techniques. From 1985 to 2011 he was group leader of the Photon Physics group, and from 2011 to 2021 he was group leader of the Ultraviolet Radiation group. He has been an associate guest researcher since his retirement in 2021
Oral History interview of Tom Lucatorto, July 13, 2023 (video file)
No full textThomas B. Lucatorto, an associate guest researcher in the Surface and Interface Metrology group of the Sensor Science division, NIST Physical Measurement Laboratory, reflects on his 51 ½ year career at NIST including his decision to join the National Bureau of Standards, his work with the Synchrotron Ultraviolet Radiation Facility (SURF), the Laser Interferometric Gravity-wave Observatory (LIGO), and with EUV lithography. A written postscript from Thomas Lucatorto, dated September 14, 2023, is included at the end of the transcript.
Thomas Lucatorto received a Ph.D. in physics from Columbia University in 1968. He was a postdoctoral research associate at Columbia University from 1968 to 1970, conducting research involving radiofrequency spectroscopy of atoms and ions. He joined the National Bureau of Standards in 1970 to investigate atomic structure using laser and synchrotron techniques. From 1985 to 2011 he was group leader of the Photon Physics group, and from 2011 to 2021 he was group leader of the Ultraviolet Radiation group. He has been an associate guest researcher since his retirement in 2021
Development and Evaluation of Bluetooth Low-Energy Device for Electronic Encounter Metrics
No full textType B Uncertainty Analysis of Gravity-Based Determinations of Triaxial-Accelerometer Properties by Simulation of Measurement Errors
No full text
Disinfection of Respirators with Ultraviolet Radiation
No full textData for interpreting virus inactivation on N95 face filtering respirators (FFRs) by ultraviolet (UV) radiation are important in developing UV strategies for N95 FFR disinfection and reuse for any situation, whether it be everyday practices, contingency planning for expected shortages, or crisis planning for known shortages. Data regarding the integrity, form, fit, and function of N95 FFR materials following UV radiation exposure are equally important. This article provides these data for N95 FFRs following UV-C irradiation (200 nm to 280 nm) in a commercial UV-C enclosure. Viral inactivation was determined by examining the inactivation of OC43, a betacoronavirus, inoculated on N95 FFRs. Different metrological approaches were used to examine irradiated N95 FFRs to determine if there were any discernible physical differences between non-irradiated N95 FFRs and those irradiated using the UV-C enclosure. Material integrity was examined using high-resolution scanning electron microscopy. Form, fit, and function were examined using flow resistance, tensile strength, and particle filtration measurements. A separate examination of filter efficiency, fit, and strap tensile stress measurements was performed by the National Personal Protective Technology Laboratory. Data from these metrological examinations provide evidence that N95 FFR disinfection and reuse using the UV-C enclosure can be effective
Capacity Models and Transmission Risk Mitigation: An Engineering Framework to Predict the Effect of Air Disinfection by Germicidal Ultraviolet Radiation
No full textUnderstanding Deformation Behavior in Uniaxial Tensile Tests of Steel Specimens at Varying Strain Rates
No full textUniaxial tensile tests are routinely conducted to obtain stress-strain data for forming applications. It is important to understand the deformation behavior of test specimens at plastic strains, temperatures, and strain rates typically encountered in metal forming processes. In this study, the Johnson-Cook (J-C) flow stress model was used to describe the constitutive behavior of ASTM International (ASTM) A 1008 steel specimens during uniaxial tensile tests at three different average strain rates (10−5 s−1, 10−3 s−1, and 10−1 s−1). The digital image correlation (DIC) technique was used for displacement and strain measurement, and two-dimensional (2D) infrared (IR) imaging was employed for temperature measurement. Separate optimization studies involving relevant finite element (FE) modeling with appropriate measured data yielded optimum values of convective heat transfer coefficients, J-C parameters, and inelastic heat fraction variables. FE modeling employing these optimum parameter values was then used to study the mechanical behavior. While FE predictions matched measured strain localization and thermal field very well in the intermediate- and low-rate experiments, the high-rate test showed narrower strain localization and a sharper temperature peak in the experiment. Possible use of a higher steel thermal conductivity value and/or exclusion of material inhomogeneities may have resulted in discrepancies between computed and measured temperature and strain fields. The study shows that an optimized set of parameters obtained with a controlled test could be reasonably applied for other tests conducted at very different strain rates
Design Considerations for a Surface Disinfection Device Using Ultraviolet-C Light-Emitting Diodes
No full textUltraviolet-C (UV-C) radiation, spanning wavelengths between 200 nm and 280 nm, has proven germicidal qualities and medical,
industrial, and environmental applications. The need for new disinfection technologies and the prospect of eliminating mercury-based
radiation sources compels research on ultraviolet (UV) light-emitting diodes (LEDs). UV-LED technology could be used for
customized and point-of-use products for disinfection and sterilization. We focused on the design and development of a surface
disinfection device using UV-C LEDs, including potential user targets, important design parameters, and final validation methods.
Optical and thermal simulations were used to illustrate the design process and associated challenges. A sample device prototype was
developed, and microbial validation results are presented