| Exploiting Unique Features of Nanodiamonds as an Advanced Energy Source |
Apr-2009 |
20 pages |
| Authors:
Betsy M Rice; Jennifer A Ciezak; William D Mattson; Radhakrishnan Balu; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS RESEARCH DIRECTORATE
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 | We present a combined experimental and theoretical study on carbon nanodiamonds (NDs) using Raman and DAC experimentation and ab initio calculations. Our calculations confirm the surface reconstruction to a fullerene-like structure, and indicate compression of the diamond core, producing an estimated internal pressure of 50 GPa. Quantum molecular dynamics simulations of hypervelocity collisions of NDs show that upon collision, shock-induced amorphization first occurs, followed by complete disruption of the ND ... |
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| Development of Carbon/Carbon Composites with Through-Thickness Carbon Nanotubes for Thermal and Structural Applications |
Dec-2008 |
34 pages |
| Authors:
Zhiyong (Richard) Liang; Chuck Zhang; FAMU/FSU COLL OF ENGINEERING TALLAHASSEE FL DEPT OF INDUSTRIAL ENGINEERING
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| Carbon/carbon composites offer lightweight thermal protection capable of producing excellent thermal materials. To further improve the thermal conductivity along the thickness direction and the interlaminar shear strength, we studied and demonstrated a novel method to stitch carbon nanotube yarns along the through-thickness direction of carbon fiber two-dimensional precursor felt perform to make novel 3D reinforced carbon/carbon (C/C) composites. By stitching nanotube yarns, high strength and thermal conductive CNTs were incorporated ... |
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| Bacterial Mixture Identification Using Raman and Surface-Enhanced Raman Chemical Imaging |
Dec-2008 |
7 pages |
| Authors:
Ashish Tripathi; Jason Guicheteau; Steven Christesen; Darren Emge; Rabih Jabbour; EDGEWOOD CHEMICAL BIOLOGICAL CENTER ABERDEEN PROVING GROUND MD
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| A number of recent studies by this group and others have demonstrated the ability of normal Raman and surface-enhanced Raman spectroscopy (SERS) to identify bacteria at the species level. Our efforts have focused on the use of colloidal silver as the SERS active substrate. The addition of silver nanoparticles to the bacteria not only produces an enhanced Raman signal, but it also suppresses the native biofluorescence associated with visible laser ... |
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| Exploring Structural Bond Energy Release (SBER) in Nanodiamonds Using Quantum Molecular Dynamics and Static High Pressure |
Dec-2008 |
8 pages |
| Authors:
Betsy M Rice; Jennifer A Ciezak; William D Mattson; Radhakrishnan Balu; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| We present a combined experimental and theoretical study on carbon nanodiamonds using Raman and DAC experimentation and ab initio calculations. Our calculations confirm the surface reconstruction to a fullerene-like structure, and indicate compression of the diamond core, producing an estimated internal pressure of 50 GPa. Quantum molecular dynamics simulations of hypervelocity collisions of NDs show that upon collision shock-induced amorphization first occurs, followed by complete disruption of the ND surface ... |
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| Metastable Polymeric Nitrogen From N2H2 Alloys |
Dec-2008 |
9 pages |
| Authors:
Jennifer A Ciezak; Timothy A Jenkins; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
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| Studies of high-density binary mixtures of simple molecular solids have uncovered a new aspect of high pressure chemistry. In contrast 10 the many previous studies on relatively inert mixtures, here we show that high pressures can lead 10 unexpected behavior in reactive compounds. Raman studies were performed on nitrogen and hydrogen binary alloys al room temperature to 83 GPa To pressures of 30 GPa, large vibron deviations from those of ... |
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| Laser Spectroscopy of Levitated Microparticles in Molecular Plasmas |
27-May-2008 |
20 pages |
| Authors:
Paul B Davies; CAMBRIDGE UNIV (UNITED KINGDOM)
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| During the past decade there has been increasing interest in the Chemistry and Physics of small particles in low temperature electric plasmas. This project aims to study spherical particles with the dimensions of microns (microspheres) levitated in molecular plasmas. A non invasive optical technique, Raman spectroscopy, is being used to probe the surface of the microspheres. Enhancement of the Raman signal will be achieved using whispering gallery modes (wgm's) in ... |
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| Quantum Information Processing with Trapped 43Ca+ Ions |
18 MAR 2008 |
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| Authors:
Rainer Blatt; INNSBRUCK UNIV (AUSTRIA) INSTITUTE OF EXPERIMENTAL PHYSICS
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 | We report on experiments with strings of laser-cooled Ca+ ions for quantum information processing. An experiment using the isotope 43Ca+ was set up from scratch. We devised techniques for loading and laser-cooling 43Ca+ ion strings, initializing the ions in the hyperfine clock states and reading out the quantum state with high efficiency. Coherence times of the qubits are about 1 s. The single-qubit gates were implemented using microwave and Raman ... |
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| Growth and Characterization of Carbon Nanotubes on Constantan (Cu-Ni-Mn Alloy) Metallic Substrates Without Adding Additional Catalysts |
Jul-2007 |
6 pages |
| Authors:
J Burke; L Brunke; J Bulmer; J Baca; K Yost; P Barnes; C V Varanasi; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH PROPULSION DIRECTORATE
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| In this study, metallic constantan (Cu55-Ni44-Mn1 wt %) alloy substrates were investigated as an alternate choice of substrates to grow carbon nanotubes (CNTs). No additional catalysts were used other than the as-rolled and annealed substrates to process CNTs on them. High density CNT growth was observed to take place on these substrates when suitable conditions were used in a thermal chemical vapor deposition (CVD) furnace with C2H2 as the carbon ... |
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| Temperature Dependence of Raman Scattering in ZnO |
06-Apr-2007 |
12 pages |
| Authors:
Buguo Wang; Ramon Cusco; Esther Alarcon-Llado; Jordi Ibanez; Luis Artus; Juan Jimenez; Michael J Callahan; AIR FORCE RESEARCH LAB HANSCOM AFB MA SENSORS DIRECTORATE
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| We present a Raman scattering study of wurtzite ZnO over a temperature range from 80 to 750 K. Second order Raman features are interpreted in the light of recent ab initio phonon density of states calculations. The temperature dependence of the Raman intensities allows the assignment of difference modes to be made unambiguously. Some weak, sharp Raman peaks are detected whose temperature dependence suggests they may be due to impurity ... |
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| Semiconductor Laser Wish List (BRIEFING CHARTS) |
07-Mar-2007 |
22 pages |
| Authors:
Henryk Temkin; DEFENSE ADVANCED RESEARCH PROJECTS AGENCY ARLINGTON VA MICROSYSTEMS TECHNOLOGY OFFICE
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| Synthesis and Characterization of Silyldichloramines, Their Reactions with F Ions, Stability of N2Cl(2) and NCl(2), and Formation of NCl(3) (PREPRINT) |
2007 |
33 pages |
| Authors:
Stefan Schneider; Michael Gerken; Ralf Haiges; Thorsten Schroer; Jerry A. Boatz; Karl O. Christe; ENGINEERING RESEARCH AND CONSULTING INC (ERC INC) EDWARDS AFB CA
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| Only two silyldichloramines, (C6H5)3SiNCl(2) and (CH3)3SiNCl(2), have been reported in the literature. The synthesis of the former was successfully repeated, and its structure was established by single crystal X-ray diffraction and vibrational spectroscopy. Attempts to prepare (CH3)3SiNCl(2) were unsuccessful, however, a new trialkylsilyldichloramine, t-BuMe2Si-NCl(2), was prepared and characterized by Raman and multinuclear NMR spectroscopy. The reaction of t-BuMe2SiNCl(2) with (CH3)4NF in CHF3 solution at -78 deg. C, followed by removal ... |
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| Exploring the High-Pressure Behavior of PETN: A Combined Quantum Mechanical and Experimental Study |
NOV 2006 |
20 pages |
| Authors:
Jennifer A. Ciezak; Edward F. Byrd; Betsy M. Rice; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| In an effort to increase the efficiency of the developmental cycle for future munitions and propellants, integration of standard atomistic simulation methods into the research and development process is being aggressively pursued. In many cases, this approach is not feasible due to the neglect of important crystalline forces in the formulations of the simulation methods. However, within high-pressure regimes it has been shown the predictions are in much closer agreement ... |
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| Bacteria Classification via Surface Enhanced Raman Spectroscopy and Principal Component Analysis |
NOV 2006 |
7 pages |
| Authors:
J. Guicheteau; S. Christesen; D. Emge; A. Hyre; L. Argue; EDGEWOOD CHEMICAL BIOLOGICAL CENTER ABERDEEN PROVING GROUND MD
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| Surface-enhanced Raman scattering (SERS) provides rapid fingerprinting of biomaterial in a non-destructive manner. The adsorption of colloidal silver to biological material suppresses native biofluorescence while increasing the normal Raman signal via the surface-enhanced Raman effect. This work validates the applicability of qualitative SER spectroscopy, utilizing principal component analysis (PCA) to show discrimination of biological threat simulants, based upon multivariate statistical confidences limits bounding known data clusters. Several strains of Bacillus ... |
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| Experimental Evidence for Linear Metal-Azide Coordination: The Binary Group 5 Azides [Nb(N3)5], [Ta(N3)5], [Nb(N3)6], and [Ta(N3)6], and 1:1 Acetonitrile Adducts [Nb(N3)5(CH3CN)] and (Ta(N3)5(CH3CN)) |
20 MAR 2006 |
7 pages |
| Authors:
Ralf Haiges; Thorsten Schroer; Muhammed Yousufuddin; Karl Christe; Jerry A. Boatz; UNIVERSITY OF SOUTHERN CALIFORNIA LOS ANGELES LOKER HYDROCARBON RESEARCH INST
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| Whereas the existence of numerous binary transition metal azido-complexes has been reported, no binary Group 5 azides are known. Only a limited number of partially azide-substituted compounds of vanadium, niobium and tantalum have previously been reported. In this paper, we wish to communicate the synthesis and characterization of Nb(N3)5, Ta(N3)5 and their 1:1 adducts with CH3CN, and of the anions [Nb(N3)6]- and [Ta(N3)6]-. The crystal structures of [Nb(N3)5(CH3CN)] and [PPh4][Nb(N3)6] ... |
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| Fiber-Based 589 nm Laser for Sodium Guide Star |
FEB 2006 |
22 pages |
| Authors:
Lars J. Nilsson; Yoonchan Jeong; Pascal Dupriez; SOUTHAMPTON UNIV (UNITED KINGDOM) OPTOELECTRONICS RESEARCH CENTRE
|
| This report results from a contract tasking University of Southampton as follows: The work will entail the construction of the required sub-assemblies, their integration into the laser source, and the exploration and adjustment of parameters in order to obtain adequate performance. We have reasonable versions of several of the needed fibers, and though we are likely to have to fabricate new fiber, this requirement is assumed to be modest. The ... |
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| A New Type of Potassium Niobate Crystal: Utilizing the Potassium Sites (Preprint) |
JAN 2006 |
18 pages |
| Authors:
Dean R. Evans; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH STRUCTURAL MATERIALS BRANCH/NONMETALLIC MATERIALS DIV
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| Darker regions (perturbed Fe- FeNb near a AgK) in the crystal exhibit strong contra-directional-TBC. There is a similar affect for interchanging NiNb for FeNb and RbK for AgK. AuK should work as well, but there's no evidence yet. The presence of Ag changes the local environment, perturbing the other impurities (i.e. Oh-), and the phonon/Raman modes are strongly affected. Ag was then purposely used as a codopant KNbO3:Fe, Ag and ... |
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| Compact, Fiber-Compatible, Cascaded Raman Laser |
01 JUN 2005 |
4 pages |
| Authors:
Bumki Min; Tobias J. Kippenberg; Kerry J. Vahala; CALIFORNIA INST OF TECH PASADENA DEPT OF APPLIED PHYSICS
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| Cascaded Raman Stokes lasing in an ultrahigh-Q silica microsphere resonator coupled to a tapered fiber is demonstrated and analyzed. With less than 900 mW of pump power near 980 nm, five cascaded Stokes lasing lines are generated. In addition, a threshold power of 56.4 mW for the first-order Stokes lasing is achieved. The Stokes lasing lines exhibit distinct characteristics depending on their order, as predicted by theoretical analysis. |
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| Acquisition of a Combined Scanning Near-Field Optical and Atomic Force Microscope |
18 MAR 2005 |
6 pages |
| Authors:
Vladimir V. Tsukruk; IOWA STATE UNIV AMES DEPT OF MATERIALSSCIENCE AND ENGINEERING
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| This project supported a new universal scanning microscope system combining near-field scanning optical microscopy (NSOM), conventional atomic force (AFM) microscopy, and confocal optical microscopy. To build a universal system capable of high-resolution topographical imaging concurrently with spectroscopic abilities, the authors have acquired several independent units and combined them into a custom-designed NSOM/AFM/Raman instrument. They have acquired an atomic force microscope (Multimode, Digital Instruments), a near- field scanning microscope (Aurora III, ... |
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| Detection of Residual Stress in SiC MEMS Using micro-Raman Spectroscopy |
MAR 2005 |
137 pages |
| Authors:
John C. Zingarelli; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT/DEPT OF ENGINEERING PHYSICS
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| Micro-Raman (mu-Raman) spectroscopy is used to measure residual stress in two silicon carbide (SiC) poly-types: single-crystal, hexagonally symmetric 6H-SiC, and polycrystalline, cubic 3C-SiC thin films deposited on Si substrates. Both are used in micro-electrical-mechanical systems (MEMS) devices. By employing an incorporated piezoelectric stage with submicron positioning capabilities along with the Raman spectral acquisition, spatial scans are performed to reveal areas in the 6H-SiC MEMS structures that contain residual stress. Shifts ... |
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| Toward the Remote Sensing of Bacterial Endospores by Raman Lidar |
26 OCT 2004 |
11 pages |
| Authors:
Elliott R. Brown; Alan W. Lee; Marie A. Celis; CALIFORNIA UNIV LOS ANGELES OFFICE OF CONTRACTS AND GRANTS ADMINISTRATION
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| This project has developed a system of biological detection at standoff using Raman lidar, a well-known method of monitoring atmospheric gases and pollutants 1. One application of a biological agent standoff detector would be in the advanced warning of a Bacillus anthracis attack. In this work we explore the feasibility of a Raman lidar system for the remote sensing of biological agents, specifically bacterial endospores. |
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| Atom Manipulation Using Optical Fields |
15 SEP 2004 |
7 pages |
| Authors:
Paul R. Berman; Tycho Sletor; MICHIGAN UNIV REGENTS ANN ARBOR DIV OFRESEARCH DEVELOPMENT AND ADMINISTRATION
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| The long range goal of this project was the creation of nanostructures using light fields to manipulate atoms. By passing an atomic beam through one or more standing wave light fields, it is possible to create modulations in the atomic density having periods which are a fraction of the period of the standing wave light fields. Patterns having periods as small as lambda/10 were observed using optical masks and clear ... |
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| Optics With Cold Atoms |
12 AUG 2004 |
12 pages |
| Authors:
Lene Hau; PRESIDENT AND FELLOWS OF HARVARD COLL CAMBRIDGE MA OFFICE OF SPONSORED RESEARCH
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| For production of novel non-linear excitations in Bose-Einstein condensates, we have enhanced the efficiency and stability of our Bose-Einstein- condensate setup by upgrading one of our primary laser pumps with a modem Verdi V-10 laser system. Furthermore, we are developing the world's most sensitive single-cold-atom detector based on free-standing carbon nanotubes to ionize neutral atoms. We have generated the facilities necessary for nanotube growth and detailed characterization with the purchase ... |
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| Detection of Molecular and Biomolecular Species by Surface-Enhanced Raman Scattering: Nanoengineered Substrates for SERS Detection |
10 AUG 2004 |
33 pages |
| Authors:
Naomi Halas; Joseph Jackson; NANOSPECTRA BIOSCIENCES INC HOUSTON TX
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| Our research has confirmed that the significant Raman enhancement from a nanoshell based substrate is generated by the electromagnetic enhancement of individual nanoshells, not aggregates (dimers, trimers, etc.). Unlike metal colloids and roughened surfaces, the significant Raman enhancements achieved are consistent across the substrate and are not related to "hot spots" associated with aggregate geometries. This will allow the reproducible manufacture of a substrate with superior enhancement for use in ... |
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| Raman Scattering by Ground-State Atomic Oxygen |
10 JUL 2004 |
7 pages |
| Authors:
Ramesh D. Sharma; AIR FORCE RESEARCH LAB HANSCOM AFB MA SPACE VEHICLES DIRECTORATE
|
| Differential cross sections for Raman scattering between the multiplet levels of the ground electronic state of atomic oxygen are calculated from first principles. The calculated cross sections are in order-of-magnitude agreement with the available experimental measurements. The use of a Raman LIDAR (Light Detection and Ranging) has the potential of giving a three-dimensional map of the density of each of the three fine structure levels of atomic oxygen. Since it ... |
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| Feasibility of Spectral Holeburning Memories and Processors for Space- Based Applications |
22 APR 2004 |
38 pages |
| Authors:
Selim Shahriar; Shaoul Ezekiel; Cardinal Warde; MASSACHUSETTS INST OF TECH CAMBRIDGE RESEARCH LAB OF ELECTRONICS
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| The purpose of this research was to explore the feasibility of using spectral hole-burning (SHB) memories for caching and processing large amounts of high-speed imagery data that are expected in future space-based surveillance systems. The research was to consist of three parts. First, the power of spectral holeburning for image-based storage and processing was to be illustrated by performing several demonstration experiments, using Raman excited spin coherence (RESC). Second, the ... |
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| Research Studies on Electromagnetically Induced Transparency |
APR 2004 |
11 pages |
| Authors:
Stephen E. Harris; LELAND STANFORD JUNIOR UNIV STANFORD CA
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| The final report describes progress in the use of electromagnetically induced transparency for the realization of new types of nonlinear interactions and processes. We have worked in two areas: (1) The generation of femtosecond pulses by phased and anti-phased molecular states and the use of this radiation for new types of physical processes, and (2) The demonstration of elementary nonlinear optical processes at low-light-levels. Highlights of the work on this ... |
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| High Energy Density Materials |
23 MAR 2004 |
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| Authors:
Ralf Haiges; Stefan Schneider; Thorsten Schroer; Karl O. Christe; ENGINEERING RESEARCH AND CONSULTING INCHUNTSVILLE AL
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| During the past two decades, polynitrogen compounds have received increasing attention as promising candidates for High Energy Density Materials (HEDM).1-17 While most of the efforts were devoted to theoretical studies, the long-known existence of the stable azide anion (N3-)18 and the recent syntheses of stable salts of the pentanitrogen cation (N5+)1-3 have demonstrated the feasibility of experimentally pursuing such materials. The only known direct method for preparing N5+ compounds is ... |
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| Preparation and Characterization of the First Binary Titanium Azides, Ti(N3)4, P(C6H5)4Ti(N3)5 and P(C6H5)42Ti(N3)6 and on Linear Ti-N-NN Coordination |
12 MAR 2004 |
21 pages |
| Authors:
Karl O. Christe; Ralf Haiges; Stefan Schneider; Thorsten Schroer; Jerry A. Boatz; ENGINEERING RESEARCH AND CONSULTING INCHUNTSVILLE AL
|
| Where as numerous partially azide-substituted titanium compounds had previously been reported, 1-7 no binary titanium azides were known. In a recent theoretical study the group 4 metal tetrazides M(N3)4 (M = Ti, Zr, Hf, Th) were predicted 8 to be vibrationally stable exhibiting tetrahedral structures with unique linear M-N-NN bond angles (see Figure 1). All previously characterized covalent binary azide species possess bent M-N-NN angles. In this paper we wish ... |
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| Aligned Single-Walled Carbon Nanotube Synthesis for Device Design |
29 FEB 2004 |
54 pages |
| Authors:
L. D. Pfefferle; G. L. Haller; Mark Reed; YALE UNIV NEW HAVEN CT
|
| This project was highly successful demonstrating control of carbon nanotube diameter through control of the synthesis process. Mean tube diameter can be preselected from 0.5 to 0.9nm. A sample predominantly semiconducting with two main tubes (7,5 and 8,3), and a sample of smaller (0.5-0.6nm) and mainly metallic tubes were produced. The process also laid the ground for production of the first pure boron nanotubes. In our SWNT synthesis experiments using ... |
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| International Workshop on Quantum Cascade Lasers. Meeting Program, Abstract Book & Attendee Roster. January 4-8, 2004, Seville, Spain |
13 JAN 2004 |
73 pages |
| Authors:
Shari J. Allwood; ALLWOOD AND ASSOCIATES INC MENTOR OH
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| This document contains abstracts of papers presented at the International Workshop on Quantum Cascade Lasers held 4 Jan 2001 in Seville, Spain. |
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| Field Tests of the Laser Interrogation of Surface Agents (Lisa) System for On-the-Move Standoff Sensing of Chemical Agents |
01-Jul-2003 |
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| Authors:
Thomas H Chyba; Robert Babnick; Quang Bui; Brian T Kelly; Dale A Richter; Patrick L Ponsardin; C T Lobb; Wayne T Armstrong; N S Higdon; Marc K Boysworth; EDGEWOOD CHEMICAL BIOLOGICAL CENTER ABERDEEN PROVING GROUND MD
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| Laser Interrogation of Surface Agents (LISA) is a new technique based on short-range Raman sensing that provides standoff detection and identification of surface-deposited chemical agents. ITT Industries, Advanced Engineering and Sciences Division is currently developing the LISA technology under a cost-sharing arrangement with the U.S. Army Soldier and Biological Chemical Command (SBCCOM) for incorporation on the Army's future reconnaissance vehicles. We will discuss the field engineered prototype LISA-Recon system, designed ... |
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| Ultraviolet Raman Spectral Signatures in Support of Lisa (Laser Interrogation of Surface Agents) |
01-Jul-2003 |
10 pages |
| Authors:
Sedlacek; Arthur J III; Charles C Finfrock; STEVE CHRISTESEN; Tom Chyba; Scott Higdon; BROOKHAVEN NATIONAL LAB UPTON NY
|
| SBCCOM/PNBC and ITT Industries are in a Cost-sharing venture on the development of LISARecon (Laser Interrogation of Surface Agents). This engineering, testing and evaluation effort uses a novel mini-Raman lidar technique for on-the-move, short-range, non-contact detection and identification of chemical agents on the battlefield. Unlike traditional lidar, LISA-Recon is specifically designed to analyze ground/surface contamination at a distance of approximately 1 meter. It is envisioned that the finished unit will ... |
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| Azulenic Chromophores For Optical Limiting and Other Nonlinear Optical Applications |
22 APR 2003 |
24 pages |
| Authors:
Alfred E. Asato; Robert S. Liu; HAWAII UNIV HONOLULU DEPT OF CHEMISTRY
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| We summarize our studies of the chemical, photophysical, optical limiting, and other nonlinear optical properties of long wavelength-absorbing azulene derivatives; namely, fluorinated azulenes, azulenic donor-acceptor molecules, and reverse saturable aborber azulenic symmetrical dye chromophores. The effect of fluorine and other substituents on the excited singlet state properties of azulene and, in particular, the enhancement of first excited state lifetimes and fluorescence quantum yields was investigated. Both Hyper-Raleigh Scattering and Resonance ... |
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| Stress Analysis of Silicon Carbide Microelectromechanical Systems Using Raman Spectroscopy |
MAR 2003 |
118 pages |
| Authors:
Stanley J. Ness; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| During the fabrication of Micro-Electro-Mechanical Systems (MEMS), residual stress is often induced in the thin films that are deposited to create these systems. These stresses can cause the device to fail due to buckling, curling, or fracture. Government and industry are looking for ways to characterize the stress during the deposition of thin films in order to reduce or eliminate device failure. Micro-Raman spectroscopy has been successfully used to analyze ... |
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| Studies of Transition States and Cluster-Induced Reactivity Via Negative Ion Photoelectron Spectroscopy |
JAN 2003 |
9 pages |
| Authors:
Daniel M. Neumark; CALIFORNIA UNIV BERKELEY SPONSORED PROJECTS OFFICE
|
| Research during the last three years has focused on using negative ion photoelectron (PE) spectroscopy and zero electron kinetic energy (ZEKE) spectroscopy to probe the effects of clustering on the energetics, spectroscopy, and dynamics of ions and transition states, and to investigate the ground and excited electronic states of reactive free radicals. We have also developed a new spectroscopic method in which stimulated Raman pumping combined with PE spectroscopy is ... |
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| First Structural Characterization of Binary As(III) and Sb(III) Azides |
2003 |
39 pages |
| Authors:
Ralf Haige; Ashwani Vij; Jerry Boatz; Stefan Schneider; Thorsten Schroer; ENGINEERING RESEARCH AND CONSULTING INC(ERC INC) EDWARDS AFB CA
|
| The highly explosive molecules As (N3)3 and Sb(N3)3 were obtained for the first time in pure form by the reactions of the corresponding fluorides with (CH3)3SiN3 in SO2 solution and purification by sublimation. The crystal structures, 14N NMR and infrared and Raman spectra were determined and the results compared to ab initio second order perturbation theory calculations. Whereas Sb(N3)3 possesses a propeller-shaped, pyramidal structure with perfect C3 symmetry, the As(N3)3 ... |
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| Polyazide Chemistry Preparation and Characterization of Te(N3)4 and P(C6H5)42Te(N3)6 |
2003 |
23 pages |
| Authors:
Ralf Haiges; Jerry A. Boatz; Michael Gerken; Stefan Schneider; Thorsten Schroer; ENGINEERING RESEARCH AND CONSULTING INC(ERC INC) EDWARDS AFB CA
|
| The azido-group is highly energetic and adds about 70 kcal/mol to the energy content of a molecule. It is, therefore, not surprising that polyazides are highly endothermic compounds, and that their energy content increases with an increasing number 9f azido ligands. Compared to the relatively stable azide anion, which possesses two double bonds, the bonds in covalent azides are polarized towards a single and a triple bond, which greatly facilitates ... |
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| Preferred Orientation in Fibers of Hipco Single Wall Carbon Nanotubes from Diffuse X-Ray Scattering |
2003 |
6 pages |
| Authors:
W. Zhou; K. I. Winey; J. E. Fischer; PENNSYLVANIA UNIV PHILADELPHIA DEPT OFMATERIALS SCIENCE AND ENGINEERING
|
| Neat Fibers of HiPco single wall carbon nanotubes extruded from strong acid suspensions exhibit preferred orientation along fiber axes. We characterize the extrusion-induced alignment using x-ray fiber diagrams and polarized Raman scattering, using a model which allows for some fraction of the sample to remain completely unaligned. We show that both x-ray and Raman data are required for a complete texture analysis of SWNT fibers. |
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| Development of an All Solid-State Raman Image Amplifier |
25 NOV 2002 |
128 pages |
| Authors:
R. C. Powell; L. K. Calmes; J. T. Murray; ARIZONA UNIV TUCSON OPTICAL SCIENCES CENTER
|
| This report describes a new type of eye-safe, range-gated lidar sensing element based on solid-state Raman image amplification (SSRIA) in a solid-state optical crystal. SSRIA can amplify low-level images in the eye-safe infrared at 1.556 pm with gains up to 106 with the addition of only quantum- limited noise. The high gains from SSRlA can compensate for low quantum efficiency detectors and can reduce the need for detector cooling. The ... |
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| Identification and Synthesis of High Nitrogen Propellants |
31 AUG 2002 |
7 pages |
| Authors:
Rodney J. Bartlett; FLORIDA UNIV GAINESVILLE QUANTUM THEORY PROJECT
|
| (SOME HIGHLlGHTS OF OUR RECENT WORK - = Provided the reference theoretical results required in the identification of the transient N4 Molecule5. = Developed new coupled-cluster methods for obtaining accurate Raman intensities, which are crucial to the identification of many polynitrogen species 6. = Showed that it is unlikely to be able to synthesize N4 with only one of two molecules excited Both need to be excited into either triplet ... |
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| Silver Colloids in Bacteria: A Study by Transmission Electron Microscopy, Absorption Spectroscopy and Elemental Analysis |
JUL 2002 |
27 pages |
| Authors:
B. V. Bronk; N. Faey; Z. Z. Li; J. Czege; R. Herd; HUMAN EFFECTIVENESS DIRECTORATE ABERDEEN PROVING GROUND MD OPERATIONAL TOXICOLOGY BRANCH
|
| Reduction of silver ions in and on bacterial cells was shown to produce silver colloids giving rise to intense surface enhanced Raman spectra (SERS) of chemical components of the cell. Transmission electron microscopy, absorption spectroscopy and elemental analysis were used to explore the distribution of silver in and on the cells produced by two different protocols. The first protocol gives rise to an internal colloid of nanometer sized silver particles ... |
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| Compact, Continuous-Beam, Cold-Atom Clock for Satellite Applications |
30 JUN 2002 |
17 pages |
| Authors:
H. Wang; W. R. Buell; AEROSPACE CORP EL SEGUNDO CA LAB OPERATIONS
|
| Highly stable atomic frequency standards are of increasing importance for a variety of space applications, ranging from communication to navigation and time transfer to tests of fundamental science. The requirements for an atomic clock vary significantly depending on the application, and for many space systems, compactness and robust design are at a premium, and stability dominates over absolute accuracy. We report on progress with our design for a compact laser-cooled ... |
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| Ion Density Fluctuations in Plasma and Their Effects on Hot Electron Generation |
JUN 2002 |
61 pages |
| Authors:
Marty Wallace; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| In this thesis, high-energy electron generation by stimulated Raman scattering of intense laser light is investigated in computer simulations. These high-energy electrons can be used to produce a high-energy x-ray source for Nuclear Weapons Effects Testing. The simulation results are compared with actual experiments conducted at the Atomic Weapons Establishment in the United Kingdom. The simulations show that the heated electron temperature is significantly lowered and the frequency spectrum of ... |
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| Nano-Optics: Coherent Nonlinear Optical Response and Control of Single Quantum Dots |
15 APR 2002 |
11 pages |
| Authors:
Duncan G. Steel; MICHIGAN UNIV ANN ARBOR
|
| Work on this program is aimed at developing and understanding nano- optical structures with the specific goal of developing and applying quantum optical methods to characterize and manipulate the quantum states of these systems. The measurements have resulted in a number of publications which demonstrate key features of new quantum mechanical structures. These features include optically induced and detected quantum entanglement of two exciton states as well as a demonstration ... |
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| Synthesis and Characterization of the SO2N3(-), (SO2)2N3(-), and SO3N3(- ) Anions |
06 MAR 2002 |
51 pages |
| Authors:
Karl O. Christe; Jerry A. Boatz; Michael Gerken; Ralf Haiges; Stefan Schneider; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE WEST
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| SO2 solutions of azide anions are bright yellow and their Raman spectra indicate the presence of covalently bound azide. Removal of the solvent at -64 deg C from CsN3 or N(CH3)4N3 solutions produces yellow (SO2)2N3(-) salts. Above -64 deg C, these salts lose one mole of SO2, resulting in white SO2N3 salts that are marginally stable at room temperature and thermally decompose to the corresponding azides and SO2. |
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| Ultralow-Threshold Raman Laser using a Spherical Dielectric Microcavity |
FEB 2002 |
4 pages |
| Authors:
S. M. Spillane; T. J. Kippenberg; K. J. Vahala; CALIFORNIA INST OF TECH PASADENA DEPT OF APPLIED PHYSICS
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| The ability to confine and store optical energy in small volumes has implications in fields ranging from cavity quantum electrodynamics to photonics. Of all cavity geometries, micrometre-sized dielectric spherical resonators are the best in terms of their ability to store energy for long periods of time within small volumes1. In the sphere, light orbits near the surface, where long confinement times (high Q) effectively wrap a large interaction distance into ... |
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| Multiphoton Processes in Systems of Rydberg Atoms |
2002 |
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| Authors:
E. A. Manykin; RUSSIAN RESEARCH CENTER MOSCOW KURCHATOV INST
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| Multiphoton nonlinear effects and Raman processes of Rydberg systems (Rydberg atom gas or Rydberg matter) by intense laser fields are considered. Some experiments and basic elements of quantum theory of Rydberg matter are briefly reviewed. A correlation between experimental data and theoretical description is made. |
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| A Compact, Continuous Beam Cold Atom Clock for Satellite Applications |
01-Nov-2001 |
13 pages |
| Authors:
Walter F Buell; He Wang; AEROSPACE CORP LOS ANGELES CA
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| Highly stable atomic frequency standards are of increasing importance for a variety of space applications, ranging from communication to navigation and time transfer to tests of fundamental science. The requirements for an atomic clock vary significantly depending on the application, and for many space systems compactness and robust design are at a premium, and stability dominates over absolute accuracy. We report on progress with our design for a compact laser-cooled ... |
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| Catalyst-Free Growth of Large Scale Ga2O3 Nanowires |
NOV 2001 |
6 pages |
| Authors:
Ko-Wei Chang; Sai-Chang Liu; Liang-Yih Chen; Franklin C. Hong; Jih-Jen Wu; NATIONAL CHENG KUNG UNIV TAINAN (TAIWAN) DEPT OF CHEMICAL ENGINEERING
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| Large scale of straight Ga2O3 nanowires is grown on a fused silica substrate by a simple catalyst-free CVD method using Ga metal and N2/H2O reactants. The Ga2O3 nanowires with diameters ranging from 60 to 150 nm can be as long as several micrometers. XRD and TEM analyses indicate that the Ga2O3 nanowires exhibit a monoclinic structure. PL characteristic of the Ga2O3 nanowires shows a UV emission of 375 nm at ... |
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| Optical Characterization and Modeling of Sulfur Incorporated Nanocrystalline Carbon Thin Films Deposited By Hot Filament CVD |
NOV 2001 |
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| Authors:
S. Gupta; B. R. Weiner; G. Morell; PUERTO RICO UNIV SAN JUAN DEPT OF PHYSICS
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| Sulfur incorporated nanocrystalline carbon (n-C:S) thin films grown on molybdenum substrates by hot-filament chemical vapor deposition (HFCVD) using gas mixtures of methane, hydrogen and a range of hydrogen sulfide (H2S) concentrations are optically examined using Raman spectroscopy (RS) and ex sin? spectroscopic phase modulated ellipsometry (SPME) from near IR to near UV (1.5-5.0 eV) obtaining their vibrational frequencies and pseudodielectric function, respectively. The ellipsometry data (< epsilon(sub r)(E) >, < ... |
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Reports by Keyword(s)
RAMAN SPECTRA
