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James E. Maslar, William A. Kimes, Brent A. Sperling
Metal alkylamide compounds, such as tetrakis(ethylmethylamido) hafnium (TEMAH), represent a technologically important class of metalorganic precursors for the deposition of metal oxides and metal nitrides via atomic layer deposition (ALD) or chemical vapor
John H. Lehman, M. Terrones, Elisabeth Mansfield, Katie Hurst, Vincent Muenier
During the past 20 years, multiwall carbon nanotubes (MWCNTs) have become an important industrial material. Hundreds of tons are produced each year. This review is a survey of the scientific literature, motivated by industrial requirements and guidelines
De-Hao D. Tsai, Melissa Davila-Morris, Frank W. DelRio, Suvajyoti S. Guha, Vincent A. Hackley, Michael R. Zachariah
Surface-sensitive quantitative studies of competitive molecular adsorption on nanoparticles were conducted using a modified Attenuated attenuated Total total Reflectionreflectance-Fourier Transform transform Infrared infrared (ATR-FTIR) spectroscopy method
A long-held but untested fundamental assumption in Raman spectroscopy of carbon nanotubes is that intensities arising from resonance with incident and scattered photons are equal. We present here the first complete Raman excitation profiles (REPs) for the
Joseph T. Hodges, A. Cygan, Piotr Maslowski, Katarzyna E. Bielska, S. Wojtewicz, J. Domyslawska, Hisashi Abe, R.S. Trawinski, R. Ciurylo
We describe a high sensitivity and high spectral resolution laser absorption spectrometer based upon the frequency-stabilized cavity ring-down spectroscopy (FS-CRDS) technique. We used the Pound-Drever-Hall (PDH) method to lock the probe laser to the high
Pahayokolide A is a cyclic undecapeptide from the cyanobacterium Lyngbya sp. The absolute configurations of the amino acids of pahayokolide A have been determined. Pahayokolide A contains the unusual α-hydroxy-β-amino acid, 3-amino-2,5,7,8- tetrahydroxy-10
Yun Han, Robert Lupitskyy, Tseng-Ming Chou, Christopher Stafford, Henry Du, Svetlana Sukhishvili
The effect of silver oxidation on surface-enhanced Raman scattering (SERS) was investigated using citrate-reduced silver nanoparticles (Ag NPs) (45-50 nm in diameter) immobilized on glass substrate. Oxidation of Ag NPs was performed in controlled ozone
Jeffrey M. Davis, Dale E. Newbury, Nicholas W. Ritchie, Edward P. Vicenzi, Dale P. Bentz, Albert J. Fahey
X-ray elemental mapping and x-ray spectrum imaging are powerful microanalytical tools. However, their scope is limited spatially by the raster area of a scanning electron microscope or microprobe. Limited sampling size becomes a significant issue when
Principal component analysis (PCA), microbeam X-ray Fluorescence Spectrometry (µXRF), and Monte Carlo simulations are used to illustrate a methodology for assessing the sample microheterogeneity for large sets of materials. PCA is demonstrated to determine
Joseph T. Hodges, David A. Long, Mitchio Okumura, Charles E. Miller
Carbon dioxide (CO2) isotopic ratios were measured at 1.6 μm through the use of frequency-stabilized cavity ring-down spectroscopy (FS-CRDS). We report the highest spectrum signal-to-noise ratios to date for CO2 transitions, with values as high as 28,000:1
Pedro Bueno, Daniel K. Havey, George W. Mulholland, Joseph T. Hodges, Keith A. Gillis, Russell R. Dickerson, Michael R. Zachariah
A quantitative understanding of the absorption and scattering properties of mixed soot and aerosol particles is necessary for evaluating the Earth's energy balance. Uncertainty in the net radiative forcing of atmospheric aerosols is relatively large and
New versions of the NIST Atomic Spectra Database (ASD, v. 4.0) and three bibliographic databases (Atomic Energy Levels and Spectra, v. 2.0, Atomic Transition Probabilities, v. 9.0, and Atomic Line Broadening and Shapes, v. 3.0) have recently been released
Juan C. Collado Gomez, Eduard Rocas, Jordi Mateu, Nathan D. Orloff, James C. Booth, Alberto Padillo, Juan Callaghan
This work proposes a procedure to characterize the intrinsic nonlinearities of bulk acoustic wave resonators by performing one port measurements of the second harmonic and second order intermodulation spurious signals. Closed-form expressions have been
Alexander M. Zolot, Ian R. Coddington, Fabrizio R. Giorgetta, Esther Baumann, William C. Swann, Nathan R. Newbury
A coherent dual comb spectrometer spanning much of the near infrared was constructed from broadened erbium fiber lasers. Gas phase water, methane and acetylene spectra were measured and characterized toward establishing new frequency standards.
Chirantha P. Rodrigo, Christian Muller, Nathan Pillsbury, William H. James III, David F. Plusquellic, Timothy Zwier
The vibronic spectroscopy of jet-cooled bis-(4-hydroxyphenyl)methane (b4HPM) has been explored using fluorescence excitation (FE), dispersed fluorescence (DFL), UV-UV holeburning (UVHB), UV depletion (UVD), and fluorescence-dip infrared (FDIR)
Eyal Gerecht, Kevin O. Douglass, David F. Plusquellic
We report the first demonstration of a broadband trace gas sensor based on chirp-pulse terahertz spectroscopy. The advent of newly developed solid state sources and heterodyne detectors for the terahertz frequency range have made it possible to generate
Frequency combs, like many ground-breaking technologies, are simple in concept; they results from the spectrum of any regular train of optical pulses. What is remarkable is that this simple picture can be actually realized in a number of different
Terrence J. Jach, Fernando D. Vila, W. T. Elam, J. D. Denlinger, John J. Rehr
Non-resonant x-ray emission spectroscopy was used to compare the nitrogen-rich compounds ammonium nitrate, trinitrotoluene, and cyclotrimethylene-trinitramine. They are representative of crystalline and molecular structures of special importance in
Mingdong M. Li, Suvajyoti S. Guha, Rebecca A. Zangmeister, Michael J. Tarlov, Michael R. Zachariah
Electrospray (ES) sources are commonly used to introduce non-volatile materials (e.g. nanoparticles, proteins, etc.) in to the gas phase for characterization by mass spectrometry and ion mobility. Recent studies in our group using electrospray ion mobility
The electronic ground-state potential surface of acetylene (H-CC-H) has a minimum at the linear conformation, but the excited electronic states may have potential minima at a variety of nonlinear equilibrium shapes. This work is concerned with the group
Ion Mobility Spectrometry (IMS) has been used for trace analysis of illicit drugs, but it can also provide reliable qualitative analysis of bulk forensic drug items, despite the complexity of these samples. The drug/drug and drug/excipient combinations
Young Jong Lee, Doyoung Moon, Kalman D. Migler, Marcus T. Cicerone
We demonstrate that broadband coherent anti-Stokes Raman scattering (CARS) microscopy can be very useful for fast acquisition of quantitative chemical images of multilayer polymer blends. Since a raw CARS signal results from coherent interference of
Jason Hattrick-Simpers, Wilbur S. Hurst, James E. Maslar, Sesha S. Srinivasan
An optical cell is described for high-throughput backscattering Raman spectroscopic measurements of hydrogen storage materials at pressures up to 10 MPa and temperatures up to 823 K. High-throughput is obtained by employing a 60 mm diameter x 9 mm thick