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Displaying 726 - 750 of 882

RAPID INSPECTION OF CARBON NANOTUBE QUALITY

July 1, 2007
Author(s)
Stephanie A. Hooker, Roy H. Geiss, Aparna Kar
Carbon nanotubes have unique properties of interest for applications in aerospace, electronics, and biotechnology. However, the properties of different batches of carbon nanotubes can vary considerably depending on chemical purity and the nanotube types

Nanostructured, multifunctional tribological coatings

May 1, 2007
Author(s)
In-Wook Park, Jianliang Lin, William C. Moerbe, Brajendra Mishra, John J. Moore, Jennifer Anton, William D. Sproul, Kwang Ho Kim, Audrey A. Vooevodin, Evgeny A. Levashov
A number of multicomponents, nanostructured coatings have been produced for a range of tribological applications. This paper will discuss four such nanocomposite coating systems: (i) Ti-Si-B-C-N; (ii) Cr-B-N; (iii) TiC-C and (iv) Cr-Al-N produced by

Temperature-Controlled Depth Profiling in Poly (methylmethacrylate) (PMMA) Using Cluster Secondary Ion Mass Spectrometry (SIMS) II. An Investigation of Sputter-Induced Topography, Chemical Damage and Depolymerization Effects

February 1, 2007
Author(s)
Christine M. Mahoney, Albert J. Fahey, John G. Gillen, Chang Xu, James Batteas
Secondary Ion Mass Spectrometry (SIMS) employing an SF polyatomic primary ion source was used to depth profile Poly(methyl methacrylate) (PMMA) at a series of temperatures from -75 C to 125 C where the primary glass transition for PMMA occurs at 105 C. The

Temperature-Controlled Depth Profiling in Poly(methylmethacrylate) (PMMA) Using Cluster Secondary Ion Mass Spectrometry (SIMS): I. Investigation of Depth Profile Characteristics

February 1, 2007
Author(s)
Christine M. Mahoney, Albert J. Fahey, John G. Gillen
Secondary Ion Mass Spectrometry (SIMS) employing an SF5+ polyatomic primary ion source was used to depth profile Poly(methyl methacrylate) (PMMA) at a series of temperatures from -75 oC to 125 oC, where the primary glass transition for PMMA occurs at 105

Mapping Mechanical Properties on the Nanoscale with Atomic Force Acoustic Microscopy

January 31, 2007
Author(s)
Donna C. Hurley, Malgorzata Kopycinska-Mueller, Tony B. Kos
We are developing tools that use the atomic force microscope (AFM) to measure mechanical properties with nanoscale spatial resolution. Contact-resonance-spectroscopy techniques such as atomic force acoustic microscopy (AFAM) involve the vibrational modes

Widefield Light Microscopy Method for High Resolution and Quantum Dot Spectral Studies

January 1, 2007
Author(s)
Cynthia J. Zeissler, Keana C. Scott, Richard D. Holbrook, Peter E. Barker, Yan Xiao
We are exploring methods to achieve 3D 200 nm resolution multispectral imaging with an ordinary inexpensive widefield microscope using incoherent white light sources and an electronically tunable filter. In this work, the capabilities were applied to

Elastic mapping and quantitative nanoscale modulus measurements of SnO2 nanobelts

December 21, 2006
Author(s)
Yuegui Zheng, Robert E. Geer, Malgorzata Kopycinska-Mueller, Donna C. Hurley
A comparative study of the elastic uniformity and modulus of single-crystal SnO2 nanobelts is presented employing two nondestructive techniques based on atomic force microscopy: differential ultrasonic force microscopy (d-UFM) and atomic force acoustic

Nanoparticle Lithography and Imaging Scanning Probe Microscopy

October 1, 2006
Author(s)
Jaroslaw Grobelny, De-Hao D. Tsai, Doo-In Kim, Pradeep N. Namboodiri, Robert F. Cook, Michael R. Zachariah
Scanning tunnelling microscopy (STM) imaging was performed on goldsurfaces with a large coverage of monodispersed silver nanoparticlessoft-landed on the surface from the gas phase. In both ambient and ultra-highvacuum conditions, STM scanning was found to

Single-Molecule Charge Transport Measurements Reveal Technique-Dependant Perturbations

August 8, 2006
Author(s)
Dwight S. Seferos, A S. Blum, James G. Kushmerick, Guillermo Bazan
We compare scanning tunneling microscopy (STM) imaging with single molecule conductive atomic force microscopy (C-AFM) measurements by probing a series of structurally-related thiol-terminated oligo(phenylenevinylene)s (OPVs) designed to have unique charge

3D Molecular Imaging SIMS

July 1, 2006
Author(s)
John G. Gillen, Albert J. Fahey, M Wagner, Christine M. Mahoney
Thin monolayer and bilayer filsm of spin cast poly(methyl methacrylate) (PMMA), poly(2-hydroxyethyl methacrylate) (PHEMA), poly(lactic) acid (PLA) and PLA doped with several pharmaceuticals have been analyzed by dynamic SIMS using SF 5+ polyatomic primary

SIMS Depth Profiling of Polymer Blends With Protein Based Drugs

July 1, 2006
Author(s)
Christine M. Mahoney, J Yu, Albert J. Fahey, J Gardella
The use of SF5+ cluster ions for depth profiling has been successful for polymer-drug mixtures and polymer blends. This study reports results of the surface and in-depth characterization of two component blend films of poly(L-lactic acid) (PLLA) and

Quantum Dot Dissemination and Behavior in Bacterial Biofilms

May 7, 2006
Author(s)
Jayne B. Morrow, Richard D. Holbrook, Cynthia J. Zeissler
Quantum dots (QDs) are colloidal semiconductor nanocrystals that photoluminescence emission is proportional to the dot size and have been utilized in fluorescent imaging in biological systems. Biofilms are communities of microorganisms attached to surfaces

Variable Magnification With Kirkpatrick-Baez Optics for Synchrotron X-Ray Microscopy

May 1, 2006
Author(s)
Terrence J. Jach, A S. Bakulin, S M. Durbin, J Pedulla, A T. Macrander
We describe the distinction between the operation of a short focal lengthx-ray microscope forming a real image with a laboratory source (convergentillumination) and with a highly collimated intense beam from a synchrotronlight source (K\{o}hler

Size-related plasticity effects in AFM silicon cantilever tips

April 17, 2006
Author(s)
Malgorzata Kopycinska-Mueller, Roy H. Geiss, Donna C. Hurley
We are developing dynamic atomic force microscopy (AFM) techniques to determine nanoscale elastic properties. Atomic force acoustic microscopy (AFAM) makes use of the resonant frequencies of an AFM cantilever while its tip contacts the sample surface at a

Elastodynamic characterization of imprinted nanolines

April 3, 2006
Author(s)
Ward L. Johnson, Colm Flannery, Sudook A. Kim, Roy H. Geiss, Christopher Soles, Paul R. Heyliger
Experimental techniques employing Brillouin light scattering (BLS) and analytical techniques employing finite-element (FE) and Farnell-Adler models are being developed for characterizing acoustic modes and determining elastic moduli and dimensions of
Displaying 726 - 750 of 882