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Displaying 451 - 475 of 1856

Compliance-Free Pulse Forming of Filamentary RRAM

September 30, 2016
Author(s)
Pragya Shrestha, David M. Nminibapiel, Jihong Kim, Helmut Baumgart, Kin (Charles) Cheung, Jason Campbell
Despite the overwhelming effort to improve the efficacy of resistive random access memory (RRAM), the underlying physics governing RRAM operation have proven elusive. A survey of the recent literature almost universally indicates that the remaining glaring

Raman spectroscopy based measurements of carrier concentration in n-type GaN nanowires grown by plasma-assisted molecular beam epitaxy

September 30, 2016
Author(s)
Lawrence H. Robins, Elizabeth Horneber, Norman A. Sanford, Kristine A. Bertness, John B. Schlager
The carrier concentration in ensembles of n-type GaN nanowires (NWs) grown by plasma-assisted molecular beam epitaxy was determined by curve-fitting analysis of Raman spectra, based on modeling of the carrier concentration dependence of the longitudinal

Volume Determination of Irregularly-shaped Quasi-spherical Nanoparticles

September 22, 2016
Author(s)
Ravikiran Attota
Nanoparticles (NPs) are widely used in diverse application areas, such as medicine, engineering, and cosmetics. The size (or volume) of NPs is one of the most important parameters for their successful application. It is relatively straightforward to

Signatures of intracrystallite and intercrystallite limitations of charge transport in polythiophenes

September 20, 2016
Author(s)
Kiarash Vakhshouri, Brandon Smith, Edwin Chan, Chenchen Wang, Alberto Salleo, Cheng Wang, Alexander Hexemer, Enrique Gomez
Charge carrier mobilities in conjugated semicrystalline polymers depend on morphological parameters such as crystallinity, crystal orientation, and connectivity between ordered regions. Despite recent progress in the development of conducting polymers, the

A Q-band free-space characterization of carbon nanotube composites

September 19, 2016
Author(s)
Ahmed M. Hassan, Jan Obrzut, Edward Garboczi
We present a free-space measurement technique for non-destructive non-contact electrical and dielectric characterization of nano-carbon composites in the Q-band frequency range of 30 GHz to 50 GHz. The experimental system and error correction model

Film morphology evolution during solvent vapor annealing of highly efficient small molecule donor/acceptor blends

September 15, 2016
Author(s)
Sebastian Engmann, Hyun W. Ro, Andrew Herzing, Chad R. Snyder, Lee J. Richter, Paul Geraghty, David Jones
Solution-processable small molecule photovoltaics based on the novel molecular donor, benzodithiophene terthiophene rhodamine (BTR), recently have shown maximum power conversion efficiencies above 8% for active layer thicknesses up to 400 nm, using post

Roles of Nanofiber Scaffold Structure and Chemistry in Directing Human Bone Marrow Stromal Cell Response

August 22, 2016
Author(s)
Sumona Sarkar, Bryan A. Baker, Desu Chen, Patrick S. Pine, Jennifer H. McDaniel, Marc L. Salit, Wolfgang Losert, Carl G. Simon Jr., Joy P. Dunkers
Nanofiber technology has emerged as a promising tool to recapitulate the native extracellular matrix structure; however the properties of nanofibers governing cell-material interactions are still largely undetermined. In this study we have systematically

Modeling and Measuring Chloride Ingress into Cracked Mortar

August 7, 2016
Author(s)
Scott Jones, Jeffery Davis, John L. Molloy, John R. Sieber, Dale P. Bentz
Chloride ingress into reinforced concrete structures is responsible for initiating corrosion of steel embedded into concrete. To aide in the prediction of concrete service life, a chloride ingress model that includes chloride binding to the cement matrix

Current status and future directions for in situ transmission electron microscopy

August 6, 2016
Author(s)
M. L. Taheri, Eric Stach, Ilke Arslan, Peter A. Crozier, Kabius Bernd, Thomas LaGrange, Andrew Minor, Seiji Takeda, Mihaela M. Tanase, Jakob B. Wagner, Renu Sharma
This review article discusses the current and future possibilities for the application of in situ transmission electron microscopy to reveal synthesis pathways and functional mechanisms in complex and nanoscale materials. The findings of a group of

Morphology-insensitive Performance Facilitates Transition from Spin-Coating to Roll-to-Roll Coating For High-Performance, Solution-Processed Solar Cells

August 2, 2016
Author(s)
Lee J. Richter, Jonathan Downing, Sebastian Engmann, Hyun W. Ro, Andrew A. Herzing, Dean M. DeLongchamp, Subhrangsu Mukherjee, Harald Ade, Maged Addelsamie, Aram Amassian, Yuhang Liu, He Yan
Solution processing via roll-to-roll (R2R) coating promises a low cost, low thermal-budget, sustainable revolution for the production of solar cells. Yet virtually all high performance solution processed research cells have been demonstrated by spin

Reversible adsorption kinetics of near surface dimer colloids

August 2, 2016
Author(s)
Paul NMN Salipante, Steven D Hudson
We investigate the effect of shape on reversible adsorption kinetics using colloidal polystyrene dimers near a solid glass surface as a model system. The interaction between colloid and wall is tuned using electrostatic, depletion, and gravity forces to

Giant surface conductivity enhancement in a carbon nanotube composite by ultraviolet light exposure

July 29, 2016
Author(s)
Christian J. Long, Nathan D. Orloff, Kevin A. Twedt, Thomas F. Lam, Luis Fernando Vargas Lara, Minhua Zhao, Bharath NMN Natarajan, Keana C. Scott, Eric Marksz, Tinh Nguyen, Jack F. Douglas, Jabez J. McClelland, Edward J. Garboczi, Jan Obrzut, James A. Liddle
Carbon nanotube composites are lightweight, multifunctional materials with readily adjustable mechanical and electrical properties—relevant to the aerospace, automotive, and sporting goods industries as high-performance building materials. Here, we combine

Self-terminated Electrodeposition of Ni, Co and Fe Ultrathin Films

July 28, 2016
Author(s)
Thomas P. Moffat
Self-terminated iron group metal electrodeposition occurs at potentials negative of the onset of water reduction due to formation of a monolayer thick hydroxide layer. Quenching of metal deposition is accompanied by an increase in dissipative energy loss

Ultraviolet/Ozone as a tool to control grafting density in surface-initiated controlled-radical polymerizations via ablation of bromine

July 21, 2016
Author(s)
Richard J. Sheridan, Sara V. Orski, Shinichiro Muramoto, Christopher M. Stafford, Kathryn L. Beers
We used an ultraviolet-ozone (UVO) cleaner to create substrates for atom-transfer radical polymerization (ATRP) with varying surface initiator coverage. We collected complementary time-of-flight secondary ion mass spectrometry (ToF-SIMS) and X-ray

An azeotropic cross-linked styrene-methacrylate network formed through rapid visible-light photo- polymerization

July 15, 2016
Author(s)
Yin Yang, Aaron A. Urbas, Andres Gonzalez-Bonet, Richard J. Sheridan, Jonathan E. Seppala, Kathryn L. Beers, Jirun Sun
A system containing well-defined functional material, a clinically practical procedure to make the material in situ, and proper analytical tools for chemical structure and kinetic studies is appealing, but currently unavailable. Herein, we introduce an all
Displaying 451 - 475 of 1856