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Light Source Effects on Aerosol Photoacoustic Spectroscopy Measurements

October 6, 2016

Author(s)

James G. Radney, Christopher D. Zangmeister

Photoacoustic spectroscopy measurements of flame-generated soot aerosol coated with small amounts of water yielded absorption enhancements that were dependent on the laser used: quasi- continuous wave (Q-CW, ≈ 650 ps pulse duration and 78 MHz repetition

The rheo-Raman microscope: Simultaneous chemical, conformational, mechanical, and microstructural measures of soft materials

October 4, 2016

Author(s)

Anthony P. Kotula, Matthew Meyer, Francesca De Vito, Jan Plog, Angela R. Hight Walker, Kalman D. Migler

We describe the design and demonstrate performance of an instrument capable of simultaneous Raman spectroscopy, rheology, and optical microscopy of materials. The instrument couples a Raman microscope with a rotational rheometer through an optically

Broadband Coherent Anti-Stokes Raman Scattering

August 11, 2016

Author(s)

Charles H. Camp

Broadband coherent anti-Stokes Raman scattering (BCARS) microspectroscopy is a unique label-free imaging modality that provides detailed chemical information at each pixel. In minutes, this technique captures a hyperspectral cube that co-registers

Ground-based, integrated path differential absorption LIDAR measurement of CO2, CH4, and H2O near 1.6 mm

August 5, 2016

Author(s)

Gerd A. Wagner, David F. Plusquellic

The eye-safe transmitter of a ground-based, integrated path differential absorption (IPDA) LIDAR (light detection and ranging) system is described and specified in detail. The transmitter is based on an actively stabilized, continuous-wave, single

Prediction of the UltravioletVisible Absorption Spectra of Polycyclic Aromatic Hydrocarbons (Dibenzo and Naphtho) Derivatives of Fluoranthene

August 3, 2016

Author(s)

Jorge O. Ona Ruales, Yosadara Ruiz-Morales

The annellation theory method has been used to predict the locations of maximum absorbance (LMA) of the ultravioletvisible (UV-Vis) spectral bands in the group of polycyclic aromatic hydrocarbons (PAHs) C24H14 (dibenzo and naphtho)derivatives of

Torsionally mediated spin-rotation hyperfine splittings at moderate to high J values in methanol

July 13, 2016

Author(s)

Sergey P. Belov, Alexandr V. Lapinov, Arthur A. Mescheryakov, Jon T. Hougen, Li-Hong Xu

This paper presents an explanation based on torsionally mediated proton-spinoverall-rotation interaction for the observation of doublet hyperfine splittings in some Lamb-dip sub-millimeter-wave transitions between ground-state torsion-rotation states of E

Measured Wavelength-Dependent Absorption Enhancement of Internally Mixed Black Carbon with Absorbing and Nonabsorbing Materials

June 30, 2016

Author(s)

Rian You, James Radney, Michael R. Zachariah, Christopher D. Zangmeister

Optical absorption spectra of laboratory generated aerosols consisting of black carbon (BC) internally mixed with nonabsorbing materials (ammonium sulfate, AS, and sodium chloride, NaCl) and BC with a weakly absorbing brown carbon surrogate derived from

Measuring multiple, weak heteronuclear 13C-2H couplings involving large 2H quadrupolar coupling constants and large 13C chemical shift anisotropy values: An experimental and theoretical REDOR study

June 30, 2016

Author(s)

Ryan C. Nieuwendaal

We discuss the implementation of a REDOR experiment that is capable of measuring multiple, weak 13C-2H dipolar couplings when 2H is a strong quadrupole and 13C exhibits large chemical shift anisotropy. We find that at 7.05 T in the presence of large 13C

Evaluating the Oxidative Potential of Indoor and Outdoor Particles with an EPR Assay

June 19, 2016

Author(s)

Shahana S. Khurshid, Steven Emmerich, Andrew K. Persily

The hydroxyl radical (OH) generating capacity of particles has been measured in several outdoor locations, but it remains unquantified in indoor environments where extended periods of exposure are likely. Total suspended particle samples were collected

Low Temperature Ionic Conductivity of an Acceptor Doped Perovskite Part II: Impedance Spectroscopy of Single Crystalline BaTiO3

June 16, 2016

Author(s)

Russell A. Maier

Low temperature conductivity mechanisms are identified in acceptor doped BaTiO3 single crystals equilibrated and quenched from high temperature under different oxygen partial pressures. A range of acceptor ionization states are quenched into samples doped

Hyperfine structure constants for singly-ionized manganese (Mn II) using Fourier Transform Spectroscopy

June 9, 2016

Author(s)

Keeley I. Townley-Smith, Gillian Nave, J C. Pickering, Richard J. Blackwell-Whitehead

We expand on the comprehensive study of hyperfi ne structure (HFS) in Mn II conducted by Holt et al. (1999) by verifying hyper fine magnetic dipole constants (A) for 20 levels previously measured by Holt et al. (1999) and deriving A constants for 47

XAFS Data Interchange: A single spectrum XAFS data file format

June 9, 2016

Author(s)

Bruce D. Ravel, M. Newville

We propose a standard data format for the interchange of XAFS data. The XAFS Data Interchange (XDI) standard is meant to encapsulate a single spectrum of XAFS along with relevant metadata. XDI is a text-based format with a simple syntax which clearly

Precision Spectroscopy to Enable Traceable Dynamic Measurements of Pressure

June 4, 2016

Author(s)

Kevin O. Douglass, Zeeshan Ahmed, Douglas A. Olson

We present recent work aimed at creating a standard for the dynamic measurement of pressure. A near-IR laser spectroscopy system is demonstrated for measuring 8 cm-1 in 50 µs with a 4 kHz repetition rate.

Distance Measurements between Paramagnetic Ligands Bound to Parallel Stranded Guanine Quadruplexes

June 2, 2016

Author(s)

Matthew P. Donohue, Veronika A. Szalai

Aside from a double helix, DNA folds into non-canonical structures, one of which is the guanine quadruplex. Cationic porphyrins bind guanine quadruplexes, but the effects of ligand binding on the structure of guanine quadruplexes with more than four

Structure Elucidation of Mixed-Linker Zeolitic Imidazolate Frameworks by Solid-State 1H CRAMPS NMR Spectroscopy and Computational Modeling

May 23, 2016

Author(s)

Ryan C. Nieuwendaal, Krishna Jayachandrababu, Ross Verploegh, Johannes Leisen, David Sholl, Sankar Nair

Mixed-linker zeolitic imidazolate frameworks (ZIFs) are nanoporous materials that exhibit continuous and controllable tunability of properties like effective pore size, hydrophobicity and organophilicity. The structure of mixed-linker ZIFs has been studied

Towards a dynamic pressure standard based on laser absorption spectroscopy

May 20, 2016

Author(s)

Kevin O. Douglass, Douglas A. Olson

We describe an approach for creating a cost-effective, field deployable dynamic pressure standard based on measurement of fundamental quantum properties of molecular systems. From the linewidth and intensities of ro-vibrational transitions we plan on

Raman analysis of bond conformations in the rotator and premelting states of normal alkanes

May 9, 2016

Author(s)

Anthony P. Kotula, Angela R. Hight Walker, Kalman D. Migler

We perform Raman spectroscopic measurements on normal alkanes (C nH 2n+2) with 21 {less than or equal to} n {less than or equal to} 60 with a specific focus on the conformational disorder that occurs below the melt temperature. We employ a three-state

Mass Spectrometry of Analytical Derivatives. 2. Ortho and Para Effects in Electron Ionization Mass Spectra of Derivatives of Hydroxyl, Mercapto and Amino Benzoic Acids

May 1, 2016

Author(s)

Nino G. Todua, Anzor I. Mikaia

Derivatives requiring either anhydrous or aqueous reaction conditions were prepared for robust and reliable gas chromatography mass spectrometry (GC-MS) characterization of hydroxyl, mercapto, and amino benzoic acids. Methylation and trialkylsilylation

How to measure absolute P3HT crystallinity via 13C CPMAS NMR

April 20, 2016

Author(s)

Ryan C Nieuwendaal

We outline the details of acquiring quantitative 13C cross-polarization magic angle spinning (CPMAS) NMR spectra on the most ubiquitous polymer for organic electronics (OE) applications, poly(3-hexylthiophene) (P3HT), despite other groups claims that

Exciton Dynamics in Monolayer Transition Metal Michalcogenides

April 19, 2016

Author(s)

Galan A. Moody, John Schaibley, Xiaodong Xu

Since the discovery of semiconducting monolayer transition metal dichalcogenides, a variety of experimental and theoretical studies have been carried out seeking to understand the intrinsic exciton population decay and valley relaxation dynamics. Reports

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

April 13, 2016

Author(s)

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

Performance specifications for point chemical vapor detectors are specified in ASTM E2885-13 and ASTM E2933-13. The performance evaluation of the detectors requires the accurate delivery of known concentrations of the chemical target to the system under

A trade-off between the mechanical strength and microwave electrical properties of functionalized and irradiated carbon nanotube sheets

April 4, 2016

Author(s)

Tiffany S. Williams, Nate Orloff, James S. Baker, Sandi G. Miller, Bharath N. Natarajan, Jan Obrzut, Linda S. McCorkle, Marisabel Lebron-Colon, James Gaier, Michael A. Meador, James Alexander Liddle

Carbon nanotube sheets are novel implementation of carbon nanotubes that enable the tailoring of electrical and mechanical properties for applications in the automotive and aerospace industries. Small molecule functionalization and/or post-processing

Mid-infrared molecular spectroscopy in the quantum noise limit

March 31, 2016

Author(s)

David A. Long, Adam J. Fleisher, Qingnan Liu, Joseph T. Hodges

A cavity ring-down spectrometer was used to reach the quantum noise limit in the mid-infrared spectral region. Quantum noise was observed not only in the individual ring-down decay events but also in the corresponding ensemble statistics with a magnitude

On the role of experimental imperfections in constructing 1H spin diffusion NMR plots for domain size measurements

March 24, 2016

Author(s)

Ryan C. Nieuwendaal

We discuss the precision of 1D chemical-shift-based 1H spin diffusion NMR experiments as well as straightforward experimental protocols for reducing errors. The 1H spin diffusion NMR experiments described herein are useful on samples that contain

Behavior of molecules and molecular ions near a field emitter

March 18, 2016

Author(s)

Ann C. Chiaramonti Debay, Baptiste Gault, Michael Ashton, Susan B. Sinnott, Michael P. Moody, David W. Saxey, D. K. Schreiber

The cold emission of particles from surfaces under intense electric fields is a process which underpins a variety of applications including atom probe tomography (APT), an analytical microscopy technique with near-atomic spatial resolution. Increasingly