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NIST Authors in Bold

Displaying 276 - 300 of 1923

Flow Resistance & Structures in Viscoelastic Channel Flows at Low Re

November 5, 2019
Author(s)
Boyang Qin, Paul Salipante, Steven Hudson, Paulo E. Arratia
The flow of viscoelastic fluids in channels and pipes remain poorly understood, particularly at low Reynolds numbers. Here, we investigate the flow of polymeric solutions in straight channels using pressure measurements and particle tracking. The law of

Active Learning Yields Better Training Data for Scientific Named Entity Recognition

November 1, 2019
Author(s)
Roselyne B. Tchoua, Aswathy Ajith, Zhi Hong, Logan T. Ward, Kyle Chard, Debra Audus, Shrayesh N. Patel, Juan J. de Pablo
Despite significant progress in natural language processing, machine learning models require substantial expert-annotated training data to perform well in tasks such as named entity recognition (NER) and entity relations extraction. Furthermore, NER is

Validating Predictive Models with Outdoor Data

October 17, 2019
Author(s)
Christopher C. White, Donald L. Hunston, Li Piin Sung, Hsiang C. Hsueh, Adam L. Pintar, Deborah S. Jacobs
The NIST service life prediction program has demonstrated success in producing validated predictions for the property change resulting from outdoor exposure for a range of polymer systems including Epoxy, Polyethylene, Polyester, Polyethylene terephthalate

Biomimetic Approach to Inhibition of Photooxidation in Organic Solar Cells Using Beta-Carotene as an Additive

October 14, 2019
Author(s)
Sebastian Engmann, Vida Turkovic, Michela Prete, Mikkel Bregnhoj, Liana Inasaridze, Dmytro Volyniuk, Filipp Obrezkov, Juozas V. Grazulevicius, Horst G. Rubahn, Pavel Troshin, Peter R. Ogilby, M. Madsen
Recent improvements in the power conversion efficiencies of organic photovoltaic (OPV) cells have highlighted the fact that OPV device lifetimes are now the main bottleneck for further advances of this technology. As such, understanding and controlling

Chain and Ion Dynamics in Precise Polyethylene Ionomers

October 11, 2019
Author(s)
Christopher L. Soles, Amalie Frischknecht, Benjamin Paren, Robert Middleton, Karen Winey, Jason Koski, Madhu Sudan Tyagi, Jacob Daniel Tarver
We analyze the dynamics from microsecond-long, atomistic molecular dynamics (MD) simulations of a series of precise poly(ethylene-co-acrylic acid) ionomers neutralized with lithium, with three different spacer lengths between acid groups on the ionomers

Degradation of sunglasses filters after long-term irradiation within solar simulator

September 18, 2019
Author(s)
Deborah Jacobs, Mauro Masili, Fernanda O. Duarte, Liliane Ventura, Christopher C. White
In our previous investigations on sunglasses standards, limits and requirements have been suggested for ocular safety. In this paper we evaluate the degradation of the lenses (category and ultraviolet protection) as sunglasses are exposed to solar

Contactless Resonant Cavity Dielectric Spectroscopic Studies of Cellulosic Paper Aging

August 28, 2019
Author(s)
Mary Kombolias, Jan Obrzut, Michael T. Postek, Dianne L. Poster, Yaw S. Obeng
The current analytical techniques for characterizing printing and graphic arts substrates, particularly those used to date and to authenticate provenance, are largely ex situ and destructive. This limits the amount of data that can be captured from an

Sequential and one-pot post-polymerization modification reactions of thiolactone-containing polymer brushes

August 19, 2019
Author(s)
Cassandra M. Reese, Brittany J. Thompson, Phillip K. Logan, Christopher Stafford, Derek L. Patton, Michael Blanton
Thiolactone chemistry has garnered significant attention as a powerful post-polymerization modification (PPM) route to mutlifunctional polymeric materials. Here, we apply this versatile chemistry to the fabrication of ultrathin, multifunctional polymer

Photovoltaic Blend Microstructure for High Efficiency Post-Fullerene Solar Cells. To Tilt or Not To Tilt?

August 5, 2019
Author(s)
Subhrangsu Mukherjee, Dean M. DeLongchamp, Gang Wang, Steven M. Swick, Micaela Matta, Joseph Strzalka, Thomas Aldrich, Ferdinand Melkonyan, Antonio Facchetti, Tobin Marks, Jenna L. Logsdon, Simone Fabiano, Wei Huang, Tony Yang, Amod Timalsina, Natalia Powers-Riggs, Joaquin Alzola, Ryan M. Young, Michael R. Wasielewski, George C. Schatz
Achieving efficient polymer solar cells (PSCs) requires a structurally optimal donor–acceptor heterojunction morphology. Here we report the combined experimental and theoretical characterization of a benzodithiophene–benzothiadiazole donor polymer series

DESIGN OF AN INTELLIGENT PYTHON CODE FOR VALIDATING CRACK GROWTH EXPONENT BY MONITORING A CRACK OF ZIG-ZAG SHAPE IN A CRACKED PIPE

July 27, 2019
Author(s)
Jeffrey T. Fong, Pedro V. Marcal, Robert B. Rainsberger, Nathanael A. Heckert, James J. Filliben
When a small crack is detected in a pressure vessel or piping, we can estimate the fatigue life of the vessel or piping by applying the classical law of fracture mechanics for crack growth if we are certain that the crack growth exponent is correct and the

Effect of Adjacent Hydrophilic Polymer Thin Films on Physical Aging and Residual Stress in Thin Films of Poly(butylnorbornene-ran-hydroxyhexafluoroisopropyl norbornene)

June 22, 2019
Author(s)
Elizabeth A. Lewis, Christopher Stafford, Bryan D. Vogt
The properties of thin supported polymer films can be dramatically impacted by the substrate upon which it resides. A simple way to alter the properties of the substrate (chemistry, rigidity, dynamics) is by coating it with an immiscible polymer. Here we

Measuring & Predicting Crystal Morphology in Fused Deposition Modeling

June 19, 2019
Author(s)
Claire McIlroy, Jonathan Seppala, Anthony Kotula
Semi-crystalline polymer melts are commonly used in fused deposition modeling. Although flows have a profound effect on polymer crystallization, the relationship between typical fused deposition modeling (FDM) deformation rates and printed-part crystal

Polymer Additive Manufacturing: Confronting Complexity

June 19, 2019
Author(s)
Anthony P. Kotula, Jonathan E. Seppala, Chad R. Snyder
Since its development and commercialization in the 1980s, polymer additive manufacturing (AM) has become a disruptive technology. In this chapter we describe the ever-increasing demands for polymer AM in industry, academia, and government, as well as the
Displaying 276 - 300 of 1923
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