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Displaying 651 - 675 of 1896

Analytical Ultracentrifugation of Carbon Nanotubes

November 26, 2014
Author(s)
Jeffrey A. Fagan
Sedimentation velocity (SV) experiments on dispersed nanoparticles are a powerful method for determining otherwise hard to evaluate properties of the nanoparticle such as the density and size of the adsorbed interfacial layer, or for a direct evaluation of

High-Relaxivity Superparamagnetic Iron Oxide Nanoworms with Decreased Immune Recognition and Long-Circulating Properties

November 24, 2014
Author(s)
Stephen E. Russek, Guankui Wang, Swetha Inturi, Natalie J. Serkova, Sergey Merkulov, Keith McCrae, Nirmal K. Banda, Dmitri Simberg
One of the core issues of nanotechnology involves masking the foreignness of nanomaterials to enable in vivo longevity and long-term immune evasion. Dextran-coated superparamagnetic iron oxide nanoparticles are very effective magnetic resonance imaging

NIST Micronutrients Measurement Quality Assurance Program Summer 2013 Comparability Studies: Results for Round Robin LXXIV Fat-Soluble Vitamins and Carotenoids in Human Serum and Round Robin 39 Ascorbic Acid in Human Serum

October 30, 2014
Author(s)
Jeanice M. Brown Thomas, David L. Duewer
The National Institute of Standards and Technology coordinates the Micronutrients Measurement Quality Assurance Program (MMQAP) for laboratories that measure fat- and water-soluble vitamins and carotenoids in human serum and plasma. This report describes

NIST Micronutrients Measurement Quality Assurance Program Winter 2013 Comparability Studies: Results for Round Robin LXXIII Fat-Soluble Vitamins and Carotenoids in Human Serum and Round Robin 38 Ascorbic Acid in Human Serum

October 30, 2014
Author(s)
Jeanice M. Brown Thomas, David L. Duewer
The National Institute of Standards and Technology coordinates the Micronutrients Measurement Quality Assurance Program (MMQAP) for laboratories that measure fat- and water-soluble vitamins and carotenoids in human serum and plasma. This report describes

A Microliter Capillary Rheometer for Characterization of Protein Solutions

October 10, 2014
Author(s)
Steven D Hudson, Prasad S. Sarangapani, Kalman D. Migler, Jai A. Pathak
Rheometry is an important characterization tool for therapeutic protein solutions because it determines syringeability and relates indirectly to solution stability and thermodynamic interactions. Despite the maturity of rheometry, there remains a need for

In-situ morphology studies of the mechanism for solution additive effects on the formation of bulk heterojunction films.

September 29, 2014
Author(s)
Lee J. Richter, Dean M. DeLongchamp, Kang W. Chou, Aram Amassian, A Hexemer, Eric Schaible, Felicia A. Bokel, Sebastian Engmann
The most successful active film morphology in organic photovoltaics is the bulk heterojunction (BHJ). The performance of a BHJ arises from a complex interplay of the spatial organization of the segregated donor and acceptor phases and the local order

TESTING AND ANALYSES OF COPOLYMER FIBERS BASED ON 5-AMINO-2-(P-AMINOPHENYL)-BENZIMIDAZOLE

September 22, 2014
Author(s)
Walter G. McDonough, Joy P. Dunkers, Amanda L. Forster, Jae Hyun Kim, Scott A. Wight, Gale A. Holmes
Since the well-publicized failure of a body armor used by a police officer at a threat level the armor had been designed to survive, it has become imperative that the long-term properties and performance of new fibers being considered for use be understood

Foam Composite Specifications and Qualification in Support of NIJ 0115.00

September 8, 2014
Author(s)
Aaron M. Forster, Emilien J. Guigues, Amanda L. Forster, Jeffrey M. Davis, Kirk D. Rice
A laminate foam composite is recommended in the National Institute of Justice (NIJ) 0115.00 standard as the backing material for testing stab resistant body armor. The foam specification originated from early work to match force-displacement profiles from

Selective Area Growth of Ga- and N-polar GaN Nanowire Arrays on Non-Polar Si (111) Substrates

September 7, 2014
Author(s)
Matthew D. Brubaker, Shannon M. Duff, Todd E. Harvey, Paul T. Blanchard, Alexana Roshko, Aric W. Sanders, Norman A. Sanford
This study presents a technique for obtaining Ga- and N-polar Gallium Nitride nanowire (GaN NW) arrays on non-polar Si (111) substrates by use of polarity-controlled AlN/GaN buffer layers. AlN films are demonstrated to adopt Al-/N-polarity for N-/Al-rich

Fullerene-free polymer solar cells with strongly reduced bimolecular recombination and field- independent charge carrier generation

August 21, 2014
Author(s)
Steffen Roland, Marcel Schubert, Brian A. Collins, Jona Kurpiers, Zhihua Chen, Antonio Facchetti, Harald Ade, Dieter Neher
Photogeneration, recombination and transport of free charge carriers in all-polymer bulk heterojunction solar cells incorporating P3HT as donor and P(NDI2OD-T2) as acceptor polymer have been investigated by the use of time delayed collection field (TDCF)

Combining nanocalorimetry and dynamic transmission electron microscopy for in situ characterization of materials processes under rapid heating and cooling

August 18, 2014
Author(s)
Michael D. Grapes, Thomas LaGrange, Lawrence Henry Friedman, Bryan W. Reed, Geoffrey H. Campbell, Timothy P. Weihs, David A. LaVan
Nanocalorimetry is a chip-based thermal analysis technique capable of analyzing endothermic and exothermic reactions at very high heating and cooling rates. Here we couple a nanocalorimeter with an extremely fast in situ microstructural characterization

Device-Level PBTI-induced Timing Jitter Increase in Circuit-Speed Random Logic Operation

July 31, 2014
Author(s)
Jiwu Lu, Canute I. Vaz, Jason P. Campbell, Jason T. Ryan, Kin P. Cheung, Guangfan Jiao, Gennadi Bersuker, Chadwin D. Young
We utilize eye-diagram measurements of timing jitter to investigate the impact of PBTI in devices subject to DC as well as ring oscillator (RO) and pseudo-random binary sequence (PRBS) stress waveforms. We observe that RO measurements miss the relevant

Ontology Analysis if Global Gene Expression Differences of Human Bone Marrow Stromal Cells Cultured on 3D Scaffolds or 2D Films

July 31, 2014
Author(s)
Bryan A. Baker, Patrick S. Pine, Kaushik Chatterjee, Girish Kumar, Jennifer H. McDaniel, Marc L. Salit, Carl G. Simon Jr.
Differences in gene expression of human bone marrow stromal cells (hBMSCs) during culture in three-dimensional (3D) nanofiber scaffolds or on two-dimensional (2D) films were investigated via pathway analysis of microarray mRNA expression profiles. Previous

Dielectric characterization by microwave cavity perturbation corrected for non-uniform fields

July 23, 2014
Author(s)
Nathan D. Orloff, Jan Obrzut, Christian J. Long, Thomas F. Lam, James C. Booth, David R. Novotny, James A. Liddle, Pavel Kabos
The non-uniform fields that occur due to the slot in the cavity through which the sample is inserted and those due to the sample geometry itself decrease the accuracy of dielectric characterization by cavity perturbation at microwave frequencies. To

Comparing Matched Polymer:Fullerene Solar Cells Made by Solution-Sequential Processing and Traditional Blend Casting: Nanoscale Structure and Device Performance

July 8, 2014
Author(s)
Andrew Herzing, Steven A. Hawks, Jordan C. Aguirre, Laura T. Schelhas, Robert Thompson, Rachel Huber, Amy Ferreira, Guangye Zhang, Robert A. Street, Sarah Tolbert, Benjamin Schwartz
Efficient bulk heterojunction (BHJ) solar cells based on polymer:fullerene photoactive layers can be created either by traditional blend casting (BC), where the components are mixed together in solution before being cast, or by solution-sequential

Cathodoluminescence Quantum Efficiency of Quantum Dot Thin Films

July 7, 2014
Author(s)
Heayoung Yoon, Christopher C. Bohn, Youngmin Lee, Seung H. Ko, Jonathan S. Steckel, Seth Coe-Sullivan, Nikolai B. Zhitenev
A thin film of quantum dots (QD) was used to visualize the local photo-response of polycrystalline CdTe solar cells by down-converting an electron beam of high energy to photons of visible light. The efficient photon generation in the QD film is compared

Accurate Fast Capacitance Measurements for Reliable Device Characterization

July 1, 2014
Author(s)
Pragya R. Shrestha, Kin P. Cheung, Jason P. Campbell, Jason T. Ryan, Helmut Baumgart
As device dimensions continue to scale, transient phenomena are becoming increasingly more important to understand for both performance and reliability considerations. Recently, fast capacitances versus voltage (CV) measurements have been gaining attention

DNA-Controlled Carbon Nanotube Partition in Polymer Aqueous Two-Phase Systems

June 28, 2014
Author(s)
Geyou Ao, Constantine Y. Khripin, Ming Zheng
Sorting single-wall carbon nanotubes (SWCNTs) of different chiralities is both scientifically interesting and technologically important. Recent studies have shown that polymer aqueous two-phase extraction is a very effective way to achieve nanotube sorting
Displaying 651 - 675 of 1896
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