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Displaying 451 - 475 of 911

Observation of Iron Spin-States using Tabletop X-ray Emission Spectroscopy and Microcalorimeter Sensors

December 2, 2015

Author(s)

Young Il Joe, Galen C. O'Neil, Luis Miaja Avila, Joseph W. Fowler, Kevin L. Silverman, Daniel S. Swetz, Joel N. Ullom, Ralph Jimenez

X-ray emission spectroscopy (XES) is a powerful probe of the electronic and chemical state of elemental species embedded within more complex compounds. X-ray sensors that combine high resolving power and high collecting efficiency are desirable for photon

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

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

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

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

Non-collinear generation of angularly isolated circularly polarized high harmonics

September 21, 2015

Author(s)

Justin M. Shaw, Daniel Hickstein, Franklin Dollar, Patrik Grychtol, Jennifer Ellis, Carlos Hernandez-Garcia, Ronny J. Knut, Christian Gentry, Henry Kapteyn, Margaret Murnane

We generate ultrashort pulses of angularly isolated, circularly polarized extreme ultraviolet (EUV) light through the first implementation of noncollinear high harmonic generation with circularly polarized driving lasers. The noncollinear geometry offers

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

Correction for stray light in optical spectroscopy of crystals

September 1, 2015

Author(s)

Richard W. Hendler, Curtis Meuse, David Travis Gallagher, Joerg Labahn, Jan Kubicek, Paul D. Smith, John W. Kakareka

It has long been known in spectroscopy that light not passing through a sample, but reaching the detector (i.e. stray light) results in a distortion of the spectrum known as absorption- flattening. In spectroscopy with crystals, one must either include

Muffin tin potentials in EXAFS analysis

September 1, 2015

Author(s)

Bruce D. Ravel

Muffin tin potentials are the standard tool for calculating the potential surface of a cluster of atoms for use in the analysis of extended x-ray-absorption fine-structure (EXAFS) data. The set of Cartesian coordinates used to define the positions of atoms

Fourier Transform Infrared Absorption Spectroscopy for Quantitative Analysis of Gas Mixtures for Homeland Security Applications

August 11, 2015

Author(s)

Kurt D. Benkstein, Wilbur S. Hurst, Douglas C. Meier, Pamela M. Chu

Chemical detectors are crucial tools for first responders during emergency-response scenarios and for continuous monitoring of public spaces for general safety. For those who depend upon chemical detectors for safety and security, ensuring that detectors

Photovoltaic switching mechanism in lateral structure hybrid Perovskite solar cells

August 5, 2015

Author(s)

Yongbo Yuan, Jungseok Chae, Yuchuan Shao, Qi Wang, Zhengguo Xiao, Andrea Centrone, Jinsong Huang

Organometal trihalide perovskite solar cells with lateral device architecture recently attracted interest because of their switchable photovoltaic effect, which potentially could be leveraged to realize transparent-electrode-free solar cells. However, the

Infrared Imaging and Spectroscopy Beyond the Diffraction Limit

July 22, 2015

Author(s)

Andrea Centrone

Progress in nanotechnology is enabled by and dependent on the availability of measurement methods with spatial resolution commensurate with nanomaterials length scales. Chemical imaging techniques, such as scattering scanning near-field optical microscopy

Proceedings of the Workshop on the Determination of the Fundamental Constants

July 17, 2015

Author(s)

Donald R. Burgess Jr.

In this editorial, we will provide a brief synopsis of the proceedings of the 2015 Workshop on the Determination of the Fundamental Constants, a broad overview of the fundamental constants themselves, and finally a short history of compilations and

Integrated path detection of CO 2 and CH 4 using a waveform driven electro-optic single sideband laser source

July 10, 2015

Author(s)

Gerd A. Wagner, Stephen Maxwell, David F. Plusquellic

Integrated path concentrations of ambient levels of carbon dioxide and methane have been measured during nighttime periods at NIST, Boulder (CO, USA), using a ground-based, eye-safe laser system. In this contribution, we describe the transmitter and

Measurement of Gas and Aerosol Phase Absorption Spectra across the Visible and Near-IR Using Supercontinuum Photoacoustic Spectroscopy

June 22, 2015

Author(s)

James G. Radney, Christopher D. Zangmeister

We demonstrate a method to measure the absorption spectra of gas and aerosol species across the visible and near-IR (500 to 840 nm) using a photoacoustic (PA) spectrometer and a pulsed supercontinuum laser source. Measurements of gas phase absorption