| Temporal and Spatial Patterns of Water Isotope Ratios (Delta2H and Delta18O) in Municipal Tap Water as Measured by TCEA-IRMS |
19 Apr 2012 |
12 pages |
| Authors:
Leila J Hamdam; Rebecca E Plummer; Richard B Coffin; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
 | An understanding of fine resolution variability in water stable isotope ratios is needed to ascertain the utility of water stable isotope ratios for observational purposes and sensor applications. While others have demonstrated that intra-annual ranges of tap water isotope ratios are relatively small (10% difference) and large geographic distances yield large variation in tap water isotope ratios (Bowen et al. 2007; Kennedy et al. 2011) further assessment of short term ... |
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| Direct-Write Polymer Nanolithography in Ultra-High Vacuum |
19 Jan 2012 |
6 pages |
| Authors:
Woo-Kyung Lee; Minchul Yang; Arnaldo R Laracuente; William P King; Lloyd J Whitman; Paul E Sheehan; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
| Polymer nanostructures were directly written onto substrates in ultra-high vacuum. The polymer ink was coated onto atomic force microscope (AFM) probes that could be heated to control the ink viscosity. Then, the ink-coated probes were placed into an ultrahigh vacuum (UHV) AFM and used to write polymer nanostructures on surfaces, including surfaces cleaned in UHV. Controlling the writing speed of the tip enabled the control over the number of monolayers ... |
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| Triclinic Polymorph of Bis(triphenylsilyl) Oxide Toluene Disolvate |
Jan 2012 |
9 pages |
| Authors:
Andrew P Purdy; Emily Smoot; Ray J Butcher; Andrew Kerr; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
| A new polymorph of the title compound, C(36)H(30)OSi(2).2C(7)H(8), is reported which is triclinic (P1(-)) insteady of possessing the previously reported rhombohedral symmetry [Hoenle et al. (1990). Acta Cryst. C46, 1982-1984]. Each of the -SiPh(3) units are related by the inversion center. The Si-O-Si moiety is linear with the O atom sitting on an inversion center, and the O-Si-(toluene ring centroid) angle is 3.69 (15) deg. Each toluene molecule is 5.622 ... |
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| Preparation of Novel Hydrolyzing Urethane Modified Thiol-Ene Networks |
25 Oct 2011 |
19 pages |
| Authors:
Nicole M Mackey; Bridget S Confait; James H Wynne; J P Buchanan; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
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| Novel tetra-functional hydrolyzing monomers were prepared from the reaction of TEOS and select alkene-containing alcohols, ethylene glycol vinyl ether or 2-allyloxy ethanol, and combined with trimethylolpropane tris(3-mercaptopropionate) (tri-thiol) in a thiol-ene click polymerization reaction to produce clear, colorless thiol-ene networks using both radiation and thermal-cure techniques. These networks were characterized for various mechanical characteristics, and found to posses Tg's (DSC), hardness, tack, and thermal stability (TGA) consistent with their molecular ... |
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| Predicting the Density-Scaling Exponent of a Glass-Forming Liquid from Prigogine-Defay Ratio Measurements |
Jul 2011 |
20 pages |
| Authors:
Ditte Gundermann; Ulf R Pedersen; Tina Hecksher; Nicholas P Bailey; Bo Jakobsen; Tage Christensen; Niels B Olsen; Thomas B Schroder; Daniel Fragiadakis; Riccardo Casalini; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
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| Understanding the origin of the dramatic temperature and density dependence of the relaxation time of glass-forming liquids is a fundamental challenge in glass science. The recently established density-scaling relation quantifies the relative importance of temperature and density for the relaxation time in terms of amaterial-dependent exponent. We showthat this exponent for approximate single-parameter liquids can be calculated from thermoviscoelastic linear-response data at a single state point, for instance an ambient-pressure ... |
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| Connection Between Dynamics and Thermodynamics of Liquids on the Melting Line |
21 Mar 2011 |
9 pages |
| Authors:
D Fragiadakis; C M Roland; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
| The dynamics of a large number of liquids and polymers exhibit scaling properties characteristic of a simple repulsive inverse power-law potential, most notably the superpositioning of relaxation data as a function of the variable TV gamma , where T is temperature, V the specific volume, and gamma a material constant. A related scaling law Tm Vm Gamma , with the same exponent Gamma = gamma, links the melting temperature Tm ... |
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| Shewanella Oneidensis MR-1 Msh Pilin Proteins are Involved in Extracellular Electron Transfer in Microbial Fuel Cells |
Jan 2011 |
6 pages |
| Authors:
Lisa A Fitzgerald; Emily R Peterson; Richard I Ray; Brenda J Little; Candace J Cooper; Erinn C Howard; Bradley R Ringeisen; Justin C Biffinger; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
| Shewanella is a microbial genus that can oxidize lactate for the reduction of insoluble electron acceptors. This reduction is possible by either direct (cell surface interaction, nanowires) or indirect (soluble redox mediators) mechanisms. However, the actual molecular identification of a nanowire has not been determined. Through mutational studies, Shewanella oneidensis MR-1 was analyzed for its ability to transfer electrons to an electrode after deletion of the structural pilin genes ( ... |
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| On-the-Fly Cross Flow Laser Guided Separation of Aerosol Particles Based on Size, Refractive Index and Density-Theoretical Analysis |
20 Dec 2010 |
17 pages |
| Authors:
A A Lall; A Terray; S J Hart; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
| Laser separation of particles is achieved using forces resulting from the momentum exchange between particles and photons constituting the laser radiation. Particles can experience different optical forces depending on their size and/or optical properties, such as refractive index. Thus, particles can move at different speeds in the presence of an optical force, leading to spatial separations. In this paper, we present a theoretical analysis on laser separation of non-absorbing aerosol ... |
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| Biocides for the Battlefield - Interim Report |
24 Sep 2010 |
27 pages |
| Authors:
James H Wynne; Preston A Fulmer; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
| The ability to disinfect surfaces and manufacture self-decontaminating surfaces has been the subject of research within the Chemistry Division of the Naval Research Laboratory. Through several previous work units, a significant synthetic undertaking was made in preparation of a variety of novel, highly mobile biocides possessing low surface energies. In addition, significant achievements in synthesis of novel classes of biocides were made, with the subsequent incorporation of these molecules into ... |
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| Lab on a Chip Packing of Submicron Particles for High Performance EOF Pumping |
26 Aug 2010 |
6 pages |
| Authors:
Qin Lu; Greg E Collins; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
| The packing of submicrometer sized silica beads inside a microchannel was enabled by a novel method which avoids the complication and limitations of generating a frit using conventional approaches and the restriction of flow using a submicrometer sized weir. A micrometer sized weir and two short columns of 5 m and 800nm silica beads packed in succession behind the weir together functioned as a high pressure frit to allow the ... |
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| Extraction of Carbon Dioxide from Seawater by an Electrochemical Acidification Cell. Part 1 - Initial Feasibility Studies |
23 Jul 2010 |
25 pages |
| Authors:
Felice DiMascio; Heather D Willauer; Dennis R Hardy; M K Lewis; Frederick W Williams; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
| An electrochemical acidification cell is developed and tested as a method for extracting large quantities of carbon dioxide from seawater for use as a feedstock for jet-fuel synthesis at sea. The electrolytic regeneration of cation exchange resin was demonstrated, allowing simultaneous and continuous ion exchange and regeneration to occur within the cell along with control of the seawater pH. The CO2 in the seawater was readily removed at pHs of ... |
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| Prediction of Isothermal Equation of State of an Explosive Nitrate Ester by van der Waals Density Functional Theory |
Jan 2010 |
4 pages |
| Authors:
Aaron C Landerville; Michael W Conroy; Ivan I Oleynik; Carter T White; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
| A newenergetic material, nitrate ester 1 (NEST-1), has shown promise as a powerful, technologically attractive explosive. Its physical properties under compression, however, are currently unknown. Accurate density functional calculations together with a reliable empirical van der Waals correction are employed to predict the isothermal hydrostatic equation of state for this material prior to any known experimental results. The accuracy of results obtained from this approach was tested against experimentally known ... |
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| Direct Injection of Seawater for the Analysis of Nitroaromatic Explosives and their Degradation Products by Micellar Electrokinetic Chromatography |
Jan 2010 |
8 pages |
| Authors:
Braden C Giordano; Dean S Burgi; Greg E Collins; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
| Practical considerations for the injection and separation of nitroaromatic explosives in seawater sample matrices are discussed. The use of high surfactant concentrations and long electrokinetic injections allows for improved detection limits. Sensitivity was enhanced by two mechanisms, improved stacking at the detector-side of the sample plug and desorption of analyte from the capillary wall by surfactant containing BGE from the inlet side of the sample plug. Calculated limits of detection ... |
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| Analytical Particle Measurements in an Optical Microflume |
Jan 2010 |
7 pages |
| Authors:
Joseph D Taylor; Alex Terray; Sean J Hart; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
| In this work, microscopic particles in a fluid flow are manipulated using forces generated by a high power laser beam. The resulting manipulations on the particles are imaged using a microscope lens connected to a CCD camera. Differential forces on particles of varying physical and chemical composition have been measured. The goal is to measure the optical forces on a diverse range of particles and catalog the associated chemical and ... |
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| The Role of Shewanella oneidensis MR-1 Outer Surface Structures in Extracellular Electron Transfer |
Jan 2010 |
10 pages |
| Authors:
Rachida A Bouhenni; Gary J Vora; Justin C Biffinger; Sheetal Shirodkar; Ken Brockman; Ricky Ray; Peter Wu; Brandy J Johnson; Eulandria M Biddle; Matthew J Marshall; Lisa A Fitzgerald; Jim K Fredrickson; Alexander S Beliaev; Bradley R Ringeisen; Daad A Saffarini; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
| The ability of the metal reducer Shewanella oneidensis MR-1 to generate electricity in microbial fuel cells (MFCs) depends on the activity of a predicted type IV prepilin peptidase; PilD. Analysis of an S. oneidensis MR-1 pilD mutant indicated that it was deficient in pili production (Msh and type IV) and type II secretion (T2S). The requirement for T2S in metal reduction has been previously identified, but the role of pili ... |
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| Probing Electron Transfer Mechanisms in Shewanella oneidensis MR-1 using a Nanoelectrode Platform and Single-Cell Imaging |
Jan 2010 |
6 pages |
| Authors:
Xiaocheng Jiang; Jinsong Hu; Lisa A Fitzgerald; Justin C Biffinger; Ping Xie; Bradley R Ringeisen; Charles M Lieber; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
| Microbial fuel cells (MFCs) represent a promising approach for sustainable energy production as they generate electricity directly from metabolism of organic substrates without the need for catalysts. However, the mechanisms of electron transfer between microbes and electrodes, which could ultimately limit power extraction, remain controversial. Here we demonstrate optically transparent nanoelectrodes as a platform to investigate extracellular electron transfer in Shewanella oneidensis MR-1, where an array of nanoholes precludes or ... |
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| Maskless Nanoscale Writing of Nanoparticle-Polymer Composites and Nanoparticle Assemblies using Thermal Nanoprobes |
14 Sep 2009 |
6 pages |
| Authors:
Woo K Lee; Zhenting Dai; William P King; Paul E Sheehan; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
| Nanoparticle polymer composites containing metal, semiconductor, magnetic, and optically active nanoparticles were deposited onto multiple substrates from a heatable atomic force microscope tip. The nanoparticle nanostructures were functional as deposited or could be etched with an oxygen plasma, revealing single nanoparticle lithographic resolution. Many types of nanoparticles can be patterned with the same technique, without the need to tailor the substrate chemistry and without solution processing. |
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| Applying State-of-the-Art Technologies to Reduce Escape Times from Fires Using Environmental Sensing, Improved Occupant Egress Guidance, and Multiple Communication Protocols |
06-Feb-2009 |
37 pages |
| Authors:
Thomas T Street; Mark H Hammond; Frederick W Williams; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
| In 2006, under contract to the Consumer Product Safety Commission (CPSC), the Naval Research Laboratory (NRL) was tasked with investigating various technology and concepts--such as visual signals and unique audible sounds--that have the potential to improve residential occupant escape in the event of fire. The investigation included an evaluation of the feasibility of incorporating new technologies or concepts to aid escape capabilities and that may improve egress times in residential ... |
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| Numerical Simulation of an Optical Chromatographic Separator |
02 Feb 2009 |
10 pages |
| Authors:
Alex Terray; H D Ladouceur; Mark Hammond; Sean J Hart; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
| Optical chromatography achieves microscale optical manipulation through the balance of optical and hydrodynamic forces on micron sized particles entrained in microfluidic flow traveling counter to the propagation of a mildly focused laser beam. The optical pressure force on a particle is specific to each particle's size, shape and refractive index. So far, these properties have been exploited in our lab to concentrate, purify and separate injected samples. But as this ... |
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| Cascade Optical Chromatography for Sample Fractionation |
Jan-2009 |
7 pages |
| Authors:
Alex Terray; Joseph D Taylor; Sean J Hart; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
| Optical chromatography involves the elegant combination of opposing optical and fluid drag forces on colloidal samples within microfluidic environments to both measure analytical differences and fractionate injected samples. Particles that encounter the focused laser beam are trapped axially along the beam and are pushed upstream from the laser focal point to rest at a point where the optical and fluid forces on the particle balance. In our recent devices particles ... |
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| Rapid Fuel Quality Surveillance Through Chemometric Modeling of Near-Infrared Spectra |
Jan-2009 |
|
| Authors:
Robert E Morris; Mark H Hammond; Jeffrey A Cramer; Kevin J Johnson; Braden C Giordano; Kirsten E Kramer; Susan L Rose-Pehrsson; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
 | The use of liquid fuels necessitates methods to assess the quality and suitability of these fuels for their intended use. Traditionally, this is performed through a series of chemical and physical tests. However, in some operational situations, streamlined methods to reliably evaluate fuel quality would offer distinct advantages. The Naval Research Laboratory has been engaged in a research program to explore and develop rapid automated fuel quality surveillance technologies. Chemometric ... |
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| Innovative Foldamers: Engineering Heterochiral Peptides |
Jan 2009 |
3 pages |
| Authors:
T D Clark; Kulp; J L III; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
| Innovative Foldamers: The field of foldamer design promises new routes to important compounds for use in sensors, smart materials, and catalysts. The term foldamer refers to a molecule that folds into a structurally stable state in solution. Proteins and peptides are an important class of natural foldamers that carry out a host of essential functions in biology, including molecular recognition, information storage, catalysis, and controlled crystallization of inorganic materials. The ... |
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| High Expansion Foam for Protecting Large Volume Mission Critical Shipboard Spaces |
Jan 2009 |
8 pages |
| Authors:
J P Farley; F W Williams; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
| NRL's Navy Technology Center for Safety and Survivability recently initiated a full-scale fire test series to demonstrate the efficacy of high expansion foam for protecting large volume shipboard spaces. High expansion foam was pursued because of its inherent ability to travel around obstructions, fill the volume in minutes, and provide a three-dimensional firefighting capability that would not depend on a manual firefighting attack to complete final extinguishment. In addition, it ... |
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| Making the Most of a Scarce Metal |
Jan 2009 |
2 pages |
| Authors:
C N Chervin; A M Lubers; J W Long; D R Rolison; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
| Precious indeed are the platinum-group metals (PGMs): ruthenium, Ru; rhodium, Rh; palladium, Pd; osmium, Os; iridium, Ir; and platinum, Pt. The earthly scarcity and concomitant cost of PGMs have always tempered their adoption in the vast array of strategic and commercial technologies in which their inclusion would yield improved performance. We can now attain the impressive electronic and electrochemical properties of ruthenium oxide -- high electronic conductivity, high capacitive charge ... |
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| The Influence of Acidity on Microbial Fuel Cells Containing Shewanella Oneidensis (PREPRINT) |
01-Sep-2008 |
9 pages |
| Authors:
Justin C Biffinger; Jeremy Pietron; Orianna Bretschger; Lloyd J Nadeau; Glenn R Johnson; Cynthia C Williams; Kenneth H Nealson; Bradley R Ringeisen; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
| Microbial fuel cells (MFCs) traditionally operate at pH values between 6 and 8. However, the effect of pH on the growth and electron transfer abilities of Shewanella oneidensis MR-1 (wild-type) and DSP10 (spontaneous mutant), bacteria commonly used in MFCs, has not been characterized. Miniature MFCs using bare graphite felt electrodes and nanoporous polycarbonate membranes with MR-1 or DSP10 cultures generated > 8 W/cu m and ~ 400 microA between pH ... |
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| Current Status and Future Research Opportunities for Electrochemical Capacitors: Relevance for Naval and Civilian Applications |
14 MAR 2008 |
20 pages |
| Authors:
Jeffrey W. Long; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
| Electrochemical capacitors (ECs) are a class of energy-storage devices that offer significant promise in bridging the performance gap that exists between the high power density derived from electrostatic capacitors and the high energy density of batteries. As such, ECs will ultimately enable technologies and applications, ranging from microelectronics to hybrid- and all-electric vehicle platforms, where current energy-storage devices are not sufficient. Further advances in EC performance and viability will require ... |
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| Geochemical Characterization of Concentrated Gas Hydrate Deposits on the Hikurangi Margin, New Zealand: Preliminary Geochemical Cruise Report |
29 FEB 2008 |
44 pages |
| Authors:
Richard B. Coffin; LeiLa Hamdan; John Pohlman; Warren Wood; Ingo Pecher; Stuart Henrys; Jens Greinert; Kevin Faure; Andrew Gorman; Alan Orpin; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
| This report provides a preliminary summary of geochemical contribution to methane hydrate research and exploration on the Hikurangi Margin, off the northeastern coast of New Zealand from June 20 to July 3, 2006. Geochemical porewater profiles taken from shallow piston cores and vertical fluid migration measured with heatflow probing were compared with seismic summaries of potential deep sediment hydrates deposits. Research goals for this expedition include: (1) Refine geophysical, geochemical, ... |
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| Aerobic Miniature Microbial Fuel Cells |
Jan 2008 |
3 pages |
| Authors:
B R Ringeisen; J C Biffinger; J Pietron; R Ray; B Little; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
| Distributed autonomous sensor (DAS) networks will require sustainable energy-scavenging power sources for persistent surveillance applications. Ideally, these power sources will scale with the sensor size (micro/nanoelectromechanical) to enable covert deployment and a small power budget. Based on their ability to sustain power production for years while scavenging energy from a variety of environments and nutrients, microbial fuel cells (MFCs) are a viable solution to power water-borne DAS networks. However, to ... |
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| Gas Hydrate Exploration, Mid Chilean Coast; Geochemical-Geophysical Survey |
27 DEC 2006 |
63 pages |
| Authors:
Richard B. Coffin; Juan Diaz; Joan Gardner; Javier Sellanes; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
| The Naval Research Laboratory (NRL), supported through ONRG-Chile, DOE/NETL, and ONR, participated in a research cruise along the mid-Chilean coast. Specific research topics addressed by NRL in this program include survey and prediction of geotechnical and geoacoustical anomalies, estimation of coastal hydrate distribution, refining protocol for hydrate exploration, and understanding the variation in microbial community diversity in hydrate-rich regions. The Chile-FONDEF goal in this program is to locate hydrates along ... |
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| Passive Badge Assessment for Long-Term, Low-Level Air Monitoring on Submarines: VOC Badge Validation |
18 DEC 2006 |
23 pages |
| Authors:
Kimberly P. Williams; Susan L. Rose-Pehrsson; David A. Kidwell; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
| Passive badge monitors for benzene, toluene, and xylene detection (cumulatively) were tested for analyte-specific air analysis onboard U.S. Navy (USN) nuclear submarines. Long-term sampling efficiency was evaluated for a 28-day period by comparing the response of the passive badge to an active tube sampling method. The badges and tubes were exposed to benzene, toluene, and xylene vapors at concentrations ranging from 0.33 to 1.98 ppm, resulting in time-weighted-average exposures ranging ... |
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| Passive Badge Assessment for Long-Term, Low-level Air Monitoring on Submarines: Acrolein Badge Validation |
30 JUN 2006 |
13 pages |
| Authors:
Kimberly P. Williams; Susan L. Rose-Pehrsson; David A. Kidwell; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
| Passive diffusion badges are being tested as a long-term, method of analyte-specific air analysis onboard U.S. Navy (USN) nuclear submarines. Passive badge monitors for acrolein detection were tested. Long-term sampling efficiency was evaluated for a 28-day period by comparing the response of the passive badge to an active tube sampling method. The badges and tubes were exposed to acrolein vapor at concentrations of 0.2 and 0.1 ppm, resulting in a ... |
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| A Simple Multichannel Fluidic System for Laminar Flow over Planar Substrates |
21 APR 2006 |
22 pages |
| Authors:
Michael P. Malito; Cy R. Tamanaha; Lloyd J. Whitman; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
| We describe the design, assembly, and operation of a multichannel fluidic system for performing laminar flow biochemical assays on planar substrates under optical inspection using standard laboratory microscopes. The basic design uses a reusable elastomer gasket, which forms the fluidic channel, sandwiched between the substrate and a sapphire plate having integrated microfluidic connections. Designs for use with both upright and inverted microscopes are described. |
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| Mechanism of Suppression and Extinguishment of Communication Cable Fire by Ultra Fine Water Mist in Cross-Flow |
14 APR 2006 |
36 pages |
| Authors:
Chuka C. Ndubizu; Ramagopal Ananth; Damian Rouson; Frederick W. Williams; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
| Water mist fire suppression experiments were performed in cross-flow on bare (without outer jacket) communication cables to simulate a worst-case scenario. As fine water droplets are injected at low inlet velocities, an initial envelope flame that engulfed the circumference of the cable recedes and forms a wake flame stabilized behind the cable. At high mist concentration and/or high air velocity, the flame is extinguished by flame shrinking rather than by ... |
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| Chemical Structure and Orientation of Ethylene on Si(114)-(2x1)/c(2x2) |
23 JAN 2006 |
8 pages |
| Authors:
D. E. Barlow; S. C. Erwin; A. R. Laracuente; L. J. Whitman; Jr Russel J. N.; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
| The basic chemical structure and orientation of ethylene chemisorbed on Si(114)-(2 1) at submonolayer coverage is characterized in ultrahigh vacuum using transmission Fourier transform infrared (FTIR) spectroscopy. The spectra are consistent with di-sigma bonding of ethylene to the surface with a preferential molecular orientation over macroscopic lengths. These results are supported by density functional theory (DFT) calculations of vibrational frequencies for optimized ethylene-Si(114) structures occupying the dimer and rebonded atom ... |
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| Airborne Magnetometry Surveys for Detection of Unexploded Ordnance |
Jan 2006 |
8 pages |
| Authors:
H H Nelson; J R McDonald; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
| Unexploded ordnance (UXO) contamination is a high-priority problem for the Department of Defense (DoD). As used here, UXO refers to explosive, propellant, or chemical-containing munitions that are armed, fired, and remain unexploded because of malfunction. Approximately 1,400 DoD sites, comprising about 10 million acres, are known to or are suspected of containing UXO. A typical site is thousands of acres; many exceed 10,000 acres, a few are several hundred thousand ... |
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| Thermal Dip Pen Nanolithography |
Jan 2006 |
3 pages |
| Authors:
P E Sheehan; W P King; A R Laracuente; M Yang; L J Whitman; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
| The steady shrinking of integrated circuits demands constant innovation. Though ever-greater resolution remains the foremost goal, many new abilities are also needed - the reduction of toxic by-products (green chemistry), integration of heterogeneous materials (e.g., organic and inorganic) into a single structure, and the production of just a few integrated circuits at low cost. We are developing a new lithographic approach, thermal Dip Pen Nano-lithography (tDPN), to both achieve greater ... |
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| Evaluation of Submarine Hydraulic System Explosion and Fire Hazards |
29 SEP 2005 |
97 pages |
| Authors:
John B. Hoover; Jean L. Bailey; Heather D. Willauer; Frederick W. Williams; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
| Although hydraulic fluids are generally considered to be low flammable liquids, it is known that they can be highly flammable and even explosive in the atomized state. Because submarine hydraulic systems operate at high pressures, it is possible that mists could be produced in the event of a system leak. Large-scale tests were conducted aboard the ex-USS Shadwell test platform, under realistic temperature and pressure conditions, to evaluate the magnitude ... |
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| Detection Limits for Nanoscale Biosensors |
15 FEB 2005 |
6 pages |
| Authors:
Paul E. Sheehan; Lloyd J. Whitman; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
| We examine through analytical calculations and finite element simulations how the detection efficiency of disk and wire-like biosensors in unmixed fluids varies with size from the micrometer to nanometer scales. Specifically, we determine the total flux of DNA-like analyte molecules on a sensor as a function of time and flow rate for a sensor incorporated into a microfluidic system. In all cases, sensor size and shape profoundly affect the total ... |
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| HELGA II: Autonomous Passive Detection of Nuclear Weapons Materials |
Jan 2005 |
3 pages |
| Authors:
R August; R Whitlock; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
| During the televised debates of the recent presidential election, both candidates listed nuclear nonproliferation as their number one priority. Attempts by rogue nations and terrorist organizations to obtain weapons-grade nuclear materials make the headline news with alarming frequency. Unfortunately, nuclear materials emit little detectable radiation, making it very hard to prevent their being smuggled into this country or to find them once they are here. Most currently available radiation detection ... |
|
| Fire Suppression Properties of Very Fine Water Mist |
Jan 2005 |
4 pages |
| Authors:
J W FLEMING; A Awtry; R S Sheinson; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
| Water mist is one of the best nongaseous fire suppression replacement agents for Halon 1301 on a mass basis. In general, small drops are more effective than larger drops, but the highly complex nature of fires defies a simple generalization. Drop size is important but so are drop transport and evaporation behavior. Understanding each of these is critical to the design of water mist fire suppression systems. Water spray systems ... |
|
| Lab-on-a-Chip Analysis of Explosives |
Jan 2005 |
4 pages |
| Authors:
G E Collins; J D Ramsey; B C Giordano; M P Chatrathi; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
| Laboratory analysis of complex real-world samples typically requires a series of time-consuming and labor-intensive steps that include sample preparation, separation, and detection. The emerging technology of microfluidic analytical devices, or Lab-on-a-Chip (LOC), allows these functions to be integrated onto a single compact platform. Such devices, due to the design simplicity available through advanced microfabrication technologies, permit the integration of various functional elements such as sample preparation and handling, sample loading, ... |
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| Bacterial Metabolism, Aromatic Biodegradation, and Lignin Biogeochemistry in Sediment Cores from Pearl Harbor, Hawaii |
14 APR 2004 |
18 pages |
| Authors:
Michael T. Montgomery; Christopher L. Osburn; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
| Heterotrophic bacteria require a source of oxygen to rapidly metabolize complex and recalcitrant carbon sources like lignin, 2,4,6 trinitrotoluene (TNT), and polycyclic aromatic hydrocarbons (PAHs). The activities of burrowing macrofauna can increase oxygenation, which may stimulate bacterial metabolism of PAHs and heterotrophic production. We measured bacterial production, PAH mineralization, and lignin subunit concentration with depth in cores taken from South Loch and Bishop's Point in Pearl Harbor, Hawaii. Bacterial metabolism ... |
|
| Water-Soluble and Optically pH-Sensitive Single-Walled Carbon Nanotubes from Surface Modification |
26 JUL 2002 |
3 pages |
| Authors:
Wei Zhao; Chulho Song; Pehr E. Pehrsson; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
| There is great interest in using single-walled carbon nanotubes (SWNTs) as nanoscale probes and sensors in biological electronics and optical devices because the electronic and optical properties of SWNTs are extremely sensitive to the surrounding environments. 1-5 For the applications of SWNTs-based sensors in a biological environment, an immediate question is how the sensors respond to the biological conditions such as pH,5c glucose, various ions, and proteins. This study requires ... |
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| Sensitive Capillary Electrophoresis Microchip Determination of Trinitroaromatic Explosives in Nonaqueous Electrolyte Following Solid Phase Extraction |
12 JUL 2002 |
8 pages |
| Authors:
Qin Lu; Greg E. Collins; Matthew Smith; Joseph Wang; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
|
| A capillary electrophoresis (CE) microchip is utilized for the sensitive separation and detection of three trinitroaromatic explosives: 1,3 5- trinitrotoluene (TNT), 1,3 ,5-trinitrobenzene (TNB) and 2,4,6-trinitrophenyl-N- methylnitramine (tetryl), in the presence of 10 other explosives and explosive derivatives in nonaqueous electrolyte (acetonitrile/methanol 87.5/12.5 (v/v), 2. 5 mM NaOH, 1 mM sodium dodecyl sulfate (sDs)). The chemical reaction of bases, e.g. hydroxide or methoxide ions, with trinitroaromatic compounds forms red colored ... |
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| Investigation of the Correlation Between Structural Relaxation Time and Configurational Entropy under High Pressure in a Chlorinated Biphenyl |
17 Jun 2002 |
7 pages |
| Authors:
R Casalini; M Paluch; J J Fontanella; C M Roland; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
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| Dielectric relaxation measurements on a chlorinated biphenyl (PCB62) were carried out over a broad frequency range, with variation of both temperature and pressure. In combination with calorimetric determinations of the configurational entropy, these data could be described using the Adam-Gibbs model. Specifically, the experimental results were interpreted using a recently introduced equation for both the temperature and pressure dependencies of the structural relaxation time. The tau(T,P) data for PCB62 yielded ... |
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| Microgating Carbon Nanotube Field Emitters by In Situ Growth Inside Open Aperture Arrays |
23 FEB 2002 |
4 pages |
| Authors:
David S. Y. Hsu; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
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| Multiwalled carbon nanotubes were grown using chemical vapor deposition inside small apertures having a horizontal gate and a sidewall insulator spacer. Emission currents up to 140 nA per cell at 63 V have been obtained. These arrays have exhibited a gate current as low as 2.5% of the anode current throughout the entire gate voltage range, representing the lowest gate to anode current ratio of gated nanotube emitters reported to ... |
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| Integrally Gated Carbon Nanotube-on-Post Field Emitter Arrays |
17 OCT 2001 |
4 pages |
| Authors:
David S. Y. Hsu; Jonathan Shaw; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
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| Carbon nanotubes (cNT) are excellent field emitters on account of their chemical, structural, and electronic properties, which afford important aspects of robustness that have been lacking in the conventional metal and silicon field emitter arrays (FEA). They possess high current-carrying capacity and mechanical strength. Their small diameters (2-50 nm) and high aspect ratios produce high geometric field enhancement, which remains nearly constant even when material is removed from the end ... |
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| Bibliography of NRL Works on X-Ray Fluorescence Authored by L. S. Birks, D. B. Brown, J. W. Criss, H. Friedman, and J. V. Gilfrich |
15 OCT 2001 |
30 pages |
| Authors:
Robert R. Whitlock; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
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| The Naval Research Laboratory (NRL) has made significant contributions to the field of X-ray fluorescence (XRF) analysis. The calculational engine of the computer code NRLXRF still powers a significant fraction of commercial XRF analysis systems. The impact of these achievements was highlighted during the celebration of NRL's 75th Anniversary in preparation for which the top 75 technologies transferred by the Laboratory were selected. Quantitative X-ray Fluorescence Analysis was among the ... |
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| Copper Sensor for Unattended Marine Operations IV: Exploration of a Dip Probe Approach Using Nafion 117 Membranes |
31 AUG 2001 |
71 pages |
| Authors:
R. A. Lamontagne; J. W. Foerster; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
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| This study has shown that: (1) the use of the chemical procedure using BCS (the Standard Method) affords both a total copper and copper: (1) analysis; (2) BCP can be imbedded in Nafion 117 by both small batch laboratory procedures and small scale-up using commercial equipment with very similar results; (3) the chemical procedures for analysis are robust and reproducible; and (4) there is a knowledge base for continuing and ... |
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| Express Tool Delivery Service/Virtual Tool Crib |
31 JAN 2001 |
11 pages |
| Authors:
John Wegand; Keith Lucas; Andrew Seelinger; Luke Davis; Edgar Bellinger; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
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| The Naval Research Laboratory (NRL), in collaboration with the Naval Sea Systems Command (NAVSEA), has developed a plan to further support the needs of the Fleet under the Capital Investment for Labor Initiative Hand Tools. NRL/ NAVSEA proposes to work with the Navy's Shore Immediate Maintenance Agency (SIMA) to enhance distribution of tools to ships force through SIMA's current tool depot system. The outlined plan describes the role of NAVSEA, ... |
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