Search Publications

Displaying 676 - 700 of 2094

Increased carrier mobility and lifetime in CdSe quantum dot thin films through surface passivation and doping

November 4, 2015

Author(s)

Daniel Straus, E. D. Goodwin, E. A. Gaulding, Shinichiro Muramoto, Murray B. Christopher, Cherie R. Kagan

Passivating surface defects and controlling the carrier concentration and mobility in quantum dot (QD) thin films is a prerequisite to designing electronic and optoelectronic devices. We investigate the effect of introducing indium in CdSe QD thin films on

Making Contact to Molecular Layers: Linking Large Ensembles of Molecules to the Outside World

November 4, 2015

Author(s)

Christina A. Hacker, Sujitra J. Pookpanratana, Curt A. Richter, Mariona Coll

In this chapter we examine the various approaches to making electrical contact to large area molecular junctions. We will highlight the experimental concerns that one must consider and the various approaches to make reliable structures and characterize the

First far-infrared high resolution analysis of the nu6 band of phosgene 35Cl2CO and 35Cl37CLCO

November 2, 2015

Author(s)

Walter J. Lafferty

A Fourier transform spectrum of phosgene (Cl2CO) has been recorded in the 22.5 μm spectral region at a resolution of 0.00102 cm-1 using a Bruker IFS125HR spectrometer coupled with synchrotron radiation leading to the observation of the ν6 vibrational bands

History of Chromatography. Hamish Small: Experimenter Extraordinaire

November 1, 2015

Author(s)

Andre M. Striegel

Hamish Small speaks to Andre Striegel about the secrets to his success in separation science and value of vague thoughts in scientific progress

Chemical Kinetics and Photochemical Data for Use in Atmospheric Studies, Evaluation No. 18

October 30, 2015

Author(s)

Vladimir L. Orkin, James B. Burkholder, S. P. Sander, J. P. D. Abbatt D. Abbatt, J. R. Barker, Robert E. Huie, C E. Kolb, Michael J. Kurylo III, David M. Wilmouth, P. H. Wine

This is the eighteenth in a series of evaluated sets of rate constants, photochemical cross sections, heterogeneous parameters, and thermochemical parameters compiled by the NASA Panel for Data Evaluation. The data are used primarily to model stratospheric

Determination of 3-D molecular orientation by polarization broadband CARS spectroscopy

October 30, 2015

Author(s)

Young J. Lee

Theoretical description is presented about a new analysis method to determine 3-diminsional (3-D) molecular orientation by concurrently analyzing polarization profiles of multiple Raman modes measured by broadband coherent anti-Stokes Raman scattering

Compositional Analysis of Biomass Reference Materials: Results from an Interlaboratory Study

October 29, 2015

Author(s)

David W. Templeton, Edward J. Wolfrum, Katherine E. Sharpless, James H. Yen

Biomass analysis methods are used to compare compositions of different lignocellulosic feedstocks, to measure component balance around unit operations, and to determine yields through biomass to biofuels processes. Four biomass reference materials (RMs)

Zero to pi continuously controllable cross-phase modulation in a Doppler-broadened N-type electromagnetically-induced-transparency medium

October 29, 2015

Author(s)

Lu Deng, Edward W. Hagley, R B. Li, C J. Zhu

We demonstrate an observation of zero to π continuously controllable cross-phase- modulation based on an N-type electromagnetically-induced-transparency scheme in a room-temperature 87Rb vapor. We theoretically and experimentally show that the signal field

Abiotic bromination of soil organic matter

October 15, 2015

Author(s)

Bruce D. Ravel, Alessandra C. Leri

Biogeochemical transformations of plant-derived soil organic matter (SOM) involve complex abiotic and microbially mediated reactions. One such reaction is halogenation, which occurs naturally in the soil environment and has been associated with enzymatic

Identification and Quantification of Six-Ring C26H16 Cata-Condensed Polycyclic Aromatic Hydrocarbons in a Complex Mixture of Polycyclic Aromatic Hydrocarbons from Coal Tar

October 8, 2015

Author(s)

Jorge O. Ona Ruales, Arun K. Sharma, Stephen A. Wise

We applied a combination of normal-phase liquid chromatography (NPLC) with ultraviolet-visible spectroscopy and gas chromatography with mass spectrometry (GC/MS) for the fractionation, identification, and quantification of six ring cata-condensed C26H16

Top-top internal rotation coupling in the microwave spectrum of pinacolone

October 8, 2015

Author(s)

Jon T. Hougen, Yueyue Zhao, Ha Vanh L. Nguyen, Wolfgang Stahl

The molecular beam Fourier-transform microwave spectrum of pinacolone (methyl tert-butyl ketone) has been measured in several regions between 4 and 40 GHz. Fits of the assigned spectrum using several computer programs based on different models for treating

A hybrid program for fitting rotationally resolved spectra of floppy molecules with one large-amplitude rotatory motion and one large-amplitude oscillatory motion

October 6, 2015

Author(s)

Isabelle Kleiner, Jon T. Hougen

A new hybrid-model fitting program for methylamine-like molecules has been developed, based on an effective Hamiltonian in which the ammonia-like inversion motion is treated using a tunneling formalism, while the internal-rotation motion is treated using

Quantitative, comparable coherent anti-Stokes Raman scattering (CARS) spectroscopy: correcting errors in phase retrieval

October 5, 2015

Author(s)

Young J. Lee, Marcus T. Cicerone

Coherent anti-Stokes Raman scattering (CARS) microspectroscopy has demonstrated significant potential for biological and materials imaging. To date, however, the primary mechanism of disseminating CARS spectroscopic information is through pseudocolor

Microwave Rotational Spectral Study of SO2-CO

October 2, 2015

Author(s)

Francis J. Lovas, Matthew K. Sprague

The microwave spectrum of the molecular complex of sulfur dioxide (SO2) with carbon monoxide (CO) has been studied with a pulsed-beam Fourier Transform Microwave Spectrometer (FTMW) from a pair of gas samples of 1 % by volume of SO2 and CO in Ar, and

CCQM Pilot Study P-140; Quantitative Surface Analysis of Multi-Element Alloy Films

October 1, 2015

Author(s)

David S. Simons, Christopher W. Szakal, William A. Osborn, Kyung Joong Kim

A pilot study for the quantitative surface analysis of multi-element alloy films has been performed by the Surface Analysis Working Group (SAWG) of the Consultative Committee for Amount of Substance (CCQM). The aim of this pilot study is to ensure the

Improving acoustic determinations of the Boltzmann constant with mass spectrometer measurements of the molar mass of argon

September 30, 2015

Author(s)

Inseok Yang, Laurent Pitre, Michael R. Moldover, Jintao Zhang, XiaoJuan Feng, Jin Seog Kim

We determined accurate values of ratios among the average molar masses MAr of 9 argon samples using two completely-independent techniques: (1) mass spectroscopy and (2) measured ratios of acoustic resonance frequencies. The two techniques yielded mutually

Mid-infrared spectroscopy beyond the diffraction limit via direct measurement of photothermal effect

September 30, 2015

Author(s)

Aaron M. Katzenmeyer, Glenn E. Holland, Jungseok Chae, Alan H. Band, Kevin Kjoller, Andrea Centrone

An atomic force microscope equipped with temperature sensitive probes was used to measure locally the photothermal effect induced by IR light absorption. This novel instrument opens a pathway to correlated topographical, chemical composition, and thermal

The Predictive Power of the Annellation Theory: The Case of the C26H16 Cata-Condensed Benzenoid Polycyclic Aromatic Hydrocarbons

September 30, 2015

Author(s)

Jorge O. Ona Ruales, Ruiz-Morales Yosadara

The Annellation Theory was applied for the establishment of the locations of maximum absorbance for the p and β bands in the UV-Vis spectra of 8 benzenoid cata-condensed polycyclic aromatic hydrocarbons, PAHs, with molecular formula C26H16 and no available

Metal-Dielectric-Metal Resonators with Deep Subwavelength Dielectric Layers Increase the Near-Field SEIRA Enhancement

September 24, 2015

Author(s)

Jungseok Chae, Basudev Lahiri, John M. Kohoutek, Glenn Holland, Henri Lezec, Andrea Centrone

Plasmonic nanostructures presenting either structural asymmetry or metal-dielectric-metal (M-D-M) architecture are commonly used structures to increase the quality factor and the near-field confinement in plasmonic materials. This characteristic can be

Time-resolved terahertz spectroscopy (TRTS) of electrically conductive metal-organic frameworks (MOFs) doped with redox active species

September 24, 2015

Author(s)

Brian G. Alberding, Edwin J. Heilweil

Metal-Organic Frameworks (MOFs) are three-dimensional coordination polymers that are well known for large pore surface area and their ability to adsorb molecules from both the gaseous and solution phases. In general, MOFs are electrically insulating, but

In-source collision induced dissociation of inorganic explosives for mass spectrometric signature detection and chemical imaging

September 23, 2015

Author(s)

Thomas P. Forbes, Edward R. Sisco

In-source collision induced dissociation (CID) coupled with laser desorption/ionization mass spectrometry (LDI-MS) demonstrated the trace detection, bulk quantification, and chemical imaging of inorganic explosives and components. The incorporation of in

The ABCs of Using Standard Reference Materials in the Analysis of Foods and Dietary Supplements: A Practical Guide

September 16, 2015

Author(s)

Katherine E. Sharpless, David L. Duewer, Katrice A. Lippa, Andrew L. Rukhin

Although "nutraceuticals" and "functional foods" seem to be ill-defined terms, both are often used to indicate a food that contains compounds providing benefits beyond basic nutrition, often with the expectation that these compounds are protective against

Metrological approaches to organic chemical purity: primary reference materials for vitamin D metabolites

September 7, 2015

Author(s)

Michael A. Nelson, Mary Bedner, Brian E. Lang, Blaza Toman, Katrice A. Lippa

Given the critical role of pure, organic compound primary reference standards used to characterize and certify chemical Certified Reference Materials (CRMs), it is essential that associated mass purity assessments be fit-for-purpose, represented by an

Broadband phase spectroscopy over turbulent air paths

September 4, 2015

Author(s)

Fabrizio R. Giorgetta, Greg B. Rieker, Esther Baumann, William C. Swann, Laura C. Sinclair, Jonathan Kofler, Ian R. Coddington, Nathan R. Newbury

Broadband atmospheric phase spectra are measured at sub-milliradian uncertainty corresponding to a 10-13 refractive index change, despite strong decoherence from atmospheric turbulence. A phase-sensitive dual-comb spectrometer acquires spectra over 233 cm

Retention projection enables accurate calculation of liquid chromatographic retention times across labs and methods

September 3, 2015

Author(s)

Yamil Simon, Daniel Abate-Pella, Dana M. Freund, Yan Ma, Adrian Hegeman, Yan Ma, Tobias Kind, O Fiehn, Birgit Beck, Emma L. Schymanski, Corey D. Broeckling, David V. Huhman, Lloyd W. Summer, Oleg V. Krokhin, Dwight R. Stoll

Identification of small molecules by liquid chromatography-mass spectrometry (LC-MS) could be greatly improved if the chromatographic retention information could be used along with mass spectral information to narrow down the lists of potential identities