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Displaying 701 - 725 of 1896

A Quantitative Study of Nanoparticle Release from Nanocoatings Exposed to UV Radiation

April 7, 2014
Author(s)
Li Piin Sung, Deborah S. Jacobs, Justin M. Gorham, Savelas A. Rabb, Xiaohong Gu, Lee L. Yu, Tinh Nguyen
Nanoparticles are increasingly used in polymer coatings (i.e., nanocoatings) to improve multiple properties of traditional coatings such as mechanical, electrical, gas barrier, and UV resistance. These high performance nanocoatings are often used in

Measuring Stem Cell Dimensionality in Tissue Scaffolds

April 1, 2014
Author(s)
Carl G. Simon Jr., Sapun Parekh, Christopher K. Tison, Girish Kumar, Tanya M. Farooque, Charles H. Camp
Many 3D scaffold systems have evolved for tissue engineering, drug screening and in vitro tissue models. However, it is not clear which scaffolds provide a 3D cell niche and there is no clear way to measure cell niche dimensionality. Advances in 3D niche

Twin Plane Re-entrant Mechanism for Catalytic Nanowire Growth

March 12, 2014
Author(s)
Andrew D. Gamalski, Peter W. Voorhees, Renu Sharma, Caterina Ducati, Stephan Hofmann
We observe a twin plane re-entrant based growth mechanism for Au catalyzed Ge nanowire growth using video-rate lattice-resolved environmental transmission electron microscopy. For a [112] growth direction, we find a convex, V-shaped liquid catalyst

Characterization of InGaN quantum disks in GaN nanowires

March 4, 2014
Author(s)
Alexana Roshko, Roy H. Geiss, John B. Schlager, Matthew D. Brubaker, Kristine A. Bertness, Norman A. Sanford, Todd E. Harvey
Catalyst-free GaN nanowires with InGaN quantum disks (QDs) were characterized by scanning/transmission elec-tron microscopy (S/TEM) and photoluminescence. A va-riety of structures, from QDs with large strain fields to apparently strain free QDs were

Constant Shape Factor Frequency Modulated Charge Pumping (FMCP)

March 3, 2014
Author(s)
Jason T. Ryan, Jason P. Campbell, Jibin Zou, Kin P. Cheung, Richard Southwick, Anthony Oates, Rue Huang
Abstract— We examine the seemingly frequency-dependent gate leakage current component of frequency-modulated charge pumping and show it to be a measurement artifact. If untreated, this results in erroneous defect density extractions. We present a constant

Dependence of the Filament Resistance on the Duration of Current Overshoot

March 3, 2014
Author(s)
Pragya R. Shrestha, David M. Nminibapiel, Jason P. Campbell, Kin P. Cheung, Helmut Baumgart, Shweta Deora, G. Bersuker
The characteristics of a conductive filament in HfO2 RRAM is shown to be dependent on the duration of the current compliance overshoot, which may occur during the filament formation process. In addition to the overshoot amplitude, the filament resistance

Fast-Capacitance for Advanced Device Characterization

March 3, 2014
Author(s)
Pragya R. Shrestha, Kin P. Cheung, Jason T. Ryan, Jason P. Campbell, Helmut Baumgart
Fast-CV measurements are frequently being used to study transient phenomena associated with advanced devices. In this study, we show that many artifacts plague this measurement and then provide a proper method to legitimize fast-CV measurements as

Effects of nanoparticle size and charge on interactions with self-assembled collagen

March 1, 2014
Author(s)
Dongbo Wang, Jing (. Ye, Steven Hudson, Keana Scott, Sheng Lin-Gibson
Recent insights into bone formation have suggested that the critical first step to the biomineralization process is the integration of small (nanometer dimension) mineral clusters into collagen fibers. Such behavior is of intrinsic interest for the areas

Laser-assisted atom probe tomography of MBE grown GaN nanowire heterostructures

February 24, 2014
Author(s)
Norman A. Sanford, Paul T. Blanchard, Matthew D. Brubaker, Kristine A. Bertness, John B. Schlager, R Kirchofer, David R. Diercks, Brian Gorman
Laser-assisted atom probe tomography (L-APT) was performed on GaN nanowires (NWs) and axial GaN/InGaN nanowire heterostructures. All samples were grown by MBE on Si(111) substrates. The laser pulse energy (PE) at 355 nm used in L-APT analysis of GaN NWs

Structure-Property Relationships in Polyethylene Fusion Bonds

February 24, 2014
Author(s)
Aaron M. Forster, Kar T. Tan, Wei-Lun Ho, Donald L. Hunston
Polyethylene (PE) is used significantly for a wide range of critical fluid transport applications from water to fossil fuels. The advantages of polyethylene are competi-tive cost compared to metallic pipe, lower corrosion rates, and toughness. The key to

Inverse Vulcanization of Elemental Sulfur to Prepare Polymeric Electrode Materials for Li-S Batteries

February 20, 2014
Author(s)
Christopher L. Soles, Vladimir P. Oleshko, Jenny J. Kim, Adam Simmonds, Jared Griebel, Jeff Pyun, Jungjin Park, Woo Jin Chung, Woo Tae Kim, Richard Glass, Yung-Eun Sun, Kookheon Char
Sulfur-rich copolymers were synthesized via inverse vulcanization to create electroactive cathode materials for lithium-sulfur battery applications. These materials exhibit enhanced capacity retention (1005 mAh/g at 100 cycles) and extended battery

Top-Down Fabrication of Large-Area GaN Micro and Nano Pillars

February 19, 2014
Author(s)
Albert Davydov, Ratan K. Debnath, B. Wen, Dipak Paramanik, Abhishek Motayed, M. King
Large-area gallim nitride (GaN) nanopillars (NPs) arrays were fabricated by plasma etching of lithographically patterned GaN thin-film grown on Si substrate. Deep-UV lithography, inductively-coupled plasma etching, and follow-on chemical treatments were

In situ temperature measurements for selective epitaxy of GaN nanowires

February 17, 2014
Author(s)
Kristine A. Bertness, Matthew D. Brubaker, Todd E. Harvey, Shannon M. Duff, Aric W. Sanders, Norman A. Sanford
We demonstrate with spatially resolved, in situ temperature measurements and ex situ reflectance measurements that differences in appearance for masked and unmasked surfaces on patterned growth substrates arise from wavelength-dependent emissivity

Role of salt on adhesion of an epoxy/aluminium (oxide) interface in aqueous environments

February 16, 2014
Author(s)
Christopher C. White, Kar T. Tan, Donald L. Hunston, Justin M. Gorham, Aaron M. Forster, Vogt D. Bryan
The durability of adhesive joints in hostile environments is a major area of concern in structural adhesive bonding. Therefore, understanding the mechanics and mechanisms of degradation of adhesive joints is a key factor for more extensive use in future

Designing High-Performance PbS and PbSe Nanocrystal Electronic Devices through Stepwise, Post-Synthesis, Colloidal Atomic Layer Deposition

February 6, 2014
Author(s)
Soong Ju Oh, Nathaniel E. Berry, Hi-Hyuk Choi, E. A. Gaulding, Hangfei Lin, Taejong Paik, Benjamin T. Diroll, Shinichiro Muramoto, Murray B. Christopher, Cherie R. Kagan
We report a facile, solution based, post synthetic colloidal atomic layer deposition (PS-cALD) process to engineer the surface stoichiometry and therefore electronic properties of lead chalcogenide nanocrystal (NC) thin films. Using the stepwise and

Nanoscale mechanics by tomographic contact resonance atomic force microscopy

January 23, 2014
Author(s)
Gheorghe NMN Stan, Santiago Solares, Bede Pittenger, Natalia Erina, Chanmin Su
We report on a quantifiable depth-dependent contact resonance AFM (CR-AFM) measurements over polystyrene-polypropylene (PS-PP) polymer blends to detail surface and sub-surface features in terms of elastic modulus and mechanical dissipation. The depth

Isolation of Specific Small Diameter Single-Wall Carbon Nanotube Species via Aqueous Two-Phase Extraction

January 21, 2014
Author(s)
Jeffrey A. Fagan, Constantine Y. Khripin, Carlos A. Silvera Batista, Jeffrey R. Simpson, Angela R. Hight Walker, Ming Zheng
Aqueous two-phase extraction (ATPE) is demonstrated to enable isolation of multiple semiconducting and metallic single-wall carbon nanotube species from a small diameter synthetic mixture. Separation by ATPE is rapid and robust, with remarkable tunability

Saponins: A sustainable surfactant. From its microwave-assisted extraction to the synthesis of monodisperse latices

January 21, 2014
Author(s)
Charlene Schnitt, Bruno Grassl, Julien C. Gigault, Vincent A. Hackley, Gaetane Lespes, Jacques Desbrieres, Virginie Pellerin, Stephanie Reynaud
Synthetic surfactants are widely used in emulsion polymerization, but it is increasingly desirable to replace them with naturally derived molecules with a reduced environmental burden. This study demonstrates the use of saponins as sustainable and

Measuring order in regioregular poly(3-hexylthiophene) with solid-state 13C CPMAS NMR

January 10, 2014
Author(s)
Ryan C. Nieuwendaal, Chad R. Snyder, Dean M. DeLongchamp
We report on details of molecular packing in high molar mass poly(3-hexylthiophene) (P3HT) by solid-state 13C {1H} cross-polarization magic angle spinning (CPMAS) NMR measurements. The degree of polymer order was estimated for two films of varied drying
Displaying 701 - 725 of 1896
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