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Displaying 801 - 825 of 941

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

Influence of surface energy and relative humidity on AFM nanomechanical contact stiffness

March 9, 2006
Author(s)
Donna C. Hurley, Malgorzata Kopycinska-Mueller, D Julthongpiput, Michael J. Fasolka
The effects of surface functionality and relative humidity (RH) on nanomechanical properties were investigated using atomic force acoustic microscopy (AFAM), a contact scanned probe microscopy (SPM) technique. Self-assembled monolayers (SAMs) with

Consistency of D 13 C Measurements Improved

February 1, 2006
Author(s)
T B. Copelen, W Brand, M Gehre, M Groening, HAJ Meijer, Blaza Toman, R. Michael Verkouteren
We present state-of-the-art measurements and data evaluation methods to show that the consistency of carbon isotope ratio measurements can be improved 39 % to 47 % by anchoring the measurement scale with two isotopic reference materials differing in carbon

Polycyclic Aromatic Hydrocarbons in Flames, in Diesel Fuels, and in Diesel Emissions

December 1, 2005
Author(s)
R Dobbins, Robert A. Fletcher, Bruce A. Benner Jr., S Hoeft
Numerous chemical analyses of gaseous and particulate samples from laboratory flames provide a library of data on the polycyclic aromatic hydrocarbons (PAH) species found in diverse flame types burning fuels consisting of pure gaseous hydrocarbons. Diesel

Direct Preparation of Particles From Liquid Suspension for ESEM or SEM Analysis

October 1, 2005
Author(s)
Scott A. Wight, Richard D. Holbrook
A simplified method for the preparation of particles from liquid suspensions has been developed. Particles are deposited directly on carbon planchets for rapid analysis by environmental scanning electron microscopy or by conventional scanning electron

IMS-Based Trace Explosives Detectors for First Responder Use

September 1, 2005
Author(s)
Jennifer R. Verkouteren, John G. Gillen, R M. Verkouteren, Robert A. Fletcher, E S. Etz, George A. Klouda, Alim A. Fatah, Philip J. Mattson
The purpose of this document is to establish minimum performance requirements and an associated test method for Ion Mobility Spectrometry (IMS) based trace explosives detectors for use by the first responder community. Information concerning the theory and

Contact mechanics and tip shape in afm-based nanomechanical measurements

August 31, 2005
Author(s)
Malgorzata Kopycinska-Mueller, Roy H. Geiss, Donna C. Hurley
Stiffness-load curves obtained in quantitative atomic force acoustic microscopy (AFAM) measurements depend on both the elastic properties of the sample and the geometry of the atomic force microscope (AFM) tip. The geometry of silicon AFM tips changes when

Miniature Piezoceramic Actuators with Improved Fatigue Resistance

June 1, 2005
Author(s)
Stephanie A. Hooker, Jens Mueller, Clayton Kostelecky, K. Womer
Piezoelectric ceramics are desirable actuator materials for many biomedical applications due to their ability to generate precise, controlled motion with applied voltage. Herein, we report the fabrication of miniature piezoelectric ceramic actuators and

Acoustical methods to determine thin-film and nanoscale mechanical properties

May 31, 2005
Author(s)
Donna C. Hurley, Roy H. Geiss, N Jennett, Malgorzata Kopycinska-Mueller, A Maxwell, Jens Mueller, David T. Read, J Wright
We describe two acoustical methods to evaluate the mechanical properties of thin films and nanoscale structures: atomic force acoustic microscopy and surface acoustic wave spectroscopy. The elastic properties of an 800-nm-thick nickel film were examined

In Situ Ellipsometric Study of PEG/Cl - Coadsorption on Cu, Ag, and Au

May 1, 2005
Author(s)
Marlon L. Walker, Lee J. Richter, Thomas P. Moffat
Spectroscopic ellipsometry was used to examine the adsorption of polyethylene glycol (PEG) and Cl- on polycrystalline Cu, Ag and Au electrodes in sulfuric acid. In halide-free sulfuric acid, PEG adsorption on Cu and Ag is minimal at potentials positive of
Displaying 801 - 825 of 941
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