Organo-soluble porphyrin mixed monolayer-protected gold nanorods were synthesized and characterized. The resulting gold nanorods encapsulated by both porphyrin thiol and alkyl thiol on their entire surface with strong covalent Au-S linkages were very stable in organic solvents without aggregation or decomposition, and exhibited unique optical properties different from their corresponding spherical ones. Alkyl thiol acts as a stabilizer not only to fill up the potential space on gold nanorod...
Topics: DTIC Archive, AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH MATERIALS AND MANUFACTURING...
Topics discussed in these viewgraphs are the role of experimentation in transformation, modeling and simulation challenges, and the Joint Advanced Warfare Program at the Institute for Defense Analyses (IDA).
Topics: DTIC Archive, Gold, Ted, INSTITUTE FOR DEFENSE ANALYSES ALEXANDRIA VA JOINT ADVANCED WARFIGHTING...
Metal nanoclusters have interesting steady state fluorescence emission, two-photon excited emission and ultrafast dynamics. A new subclass of fluorescent silver nanoclusters (Ag NCs) are NanoCluster Beacons. NanoCluster Beacons consist of a weakly emissive Ag NC templated on a single stranded DNA (Ag NC on ssDNA'') that becomes highly fluorescent when a DNA enhancer sequence is brought in proximity to the Ag NC by DNA base pairing (Ag NC on dsDNA''). Steady state fluorescence was observed at...
Topics: DTIC Archive, MICHIGAN UNIV ANN ARBOR DEPT OF CHEMISTRY, *DEOXYRIBONUCLEIC ACIDS, *EMISSION,...
We have investigated the surface plasmon enhancement of the GeSn p-i-n photodiode using gold metal nanostructures. We have conducted numerical simulation of the plasmonic structure of 2D nano-hole array to tune the surface plasmon resonance into the absorption range of the GeSn active layer. Such a structure is fabricated using FIB on a previously made photodiode for feasibility demonstration. The result indicates that the photocurrent of the diode can indeed be enhanced with the plasmonic...
Topics: DTIC Archive, MASSACHUSETTS UNIV DARTMOUTH, *DETECTORS, *EMITTERS, *NANOSTRUCTURES, *PHOTODIODES,...
The Battle of Powder River occurred on 17 March 1876 in southeastern Montana. Historians and researchers have consistently overlooked the importance of this battle on the outcome of the Great Sioux War of 1876. Colonel Joseph J. Reynolds set out to destroy the Indian camp established by the combined Cheyenne and Oglala Sioux in order to push the Indians back to the reservations and allow miners to enter the Black Hills to mine gold. Reynolds failed to accomplish this mission. The intelligence...
Topics: DTIC Archive, Hedegaard, Michael L, ARMY COMMAND AND GENERAL STAFF COLL FORT LEAVENWORTH KS,...
The prospects of utilizing atomic-resolution scanning tunneling microscopy (STM) as a real-space in-situ probe of molecular transformations on electrochemical surfaces are illustrated for the specific case of sulfide electrooxidation on Au(111) in aqueous solution. At relatively low electrode potentials, sulfide adsorption yields ordered ( 3 x 3)R30 deg layers. The onset of sulfide electrooxidation produces marked changes in the adsorbate structure, arrays of rectangular close-packed structures...
Topics: DTIC Archive, Gao, X, PURDUE UNIV LAFAYETTE IN DEPT OF CHEMISTRY, *ELECTROCHEMISTRY, *MICROSCOPY,...
Techniques developed in metallizing glass, ceramics, and similar materials by the application and firing of metallic paints have been greatly stimulated recently by the development of new uses in radio and electronics. While metallic films on glass have used for hundreds of years, particularly gold and silver for decorative purposes, this chapter will consider in greatest detail materials and methods employable in the newer applications such as printed circuits. Metallic paints are mixtures of...
Topics: DTIC Archive, Wein, Samuel, BUREAU OF AERONAUTICS (NAVY) WASHINGTON DC, *ELECTRONIC EQUIPMENT,...
This report presents research results and activities carried out during the period January 15, 1989 through January 14, 1993 sponsored by AFOSR Grant No. AFOSR-89-0253. Work was carried out at the University of Nebraska (UNL), and at the University of Texas at Arlington (UTA). The work at each of these locations is discussed in detail in separate sections of this report. Important conclusions are: (1) The phenomenon commonly referred to as surface flashover in silicon results from a sequence of...
Topics: DTIC Archive, Williams, P F, NEBRASKA UNIV LINCOLN DEPT OF ELECTRICAL ENGINEERING, *ELECTRIC...
Nanoparticulate metal-insulator-metal ensemble chemiresistors in which the Au nanoclusters are functionalized with mercaptohexanoic acid are investigated as sensors of amines, and especially of triethylamine to which they are found to be extraordinarily sensitive with a minimum detectable level of less than 500 ppt. The dependences of the response on dose, time, and temperature are studied in detail. Modeling indicates that the entire data set is well explained by the interaction of...
Topics: DTIC Archive, NAVAL RESEARCH LAB WASHINGTON DC, *REACTION KINETICS, AMINES, DETECTORS, DIFFUSION,...
DNase 1-stabilized gold nanoclusters (DNase 1 AuNCs) were synthesized with multiple energy levels in a metal-concentration-dependant fashion. From multiple characterization techniques including fluorescence spectroscopy, high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy, we assigned 2 reaction products to contain pure populations of clusters with core sizes of 8 and 25 Au atoms for the products where 10- and 2.5-mM HAuCl4 was used in the reaction,...
Topics: DTIC Archive, ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD, *X RAY PHOTOELECTRON SPECTROSCOPY,...
We report the thermal conductance G of Au/Ti/graphene/SiO2 interfaces (graphene layers 1 or = n or = 10) typical of graphene transistor contacts. We find G approx. = 25 MW/sq m/K at room temperature, four times smaller than the thermal conductance of a Au/Ti/SiO2 interface, even when n = 1. We attribute this reduction to the thermal resistance of Au/Ti/graphene and graphene/SiO2 interfaces acting in series. The temperature dependence of G from 50 , or = T or = 500 K also indicates that heat is...
Topics: DTIC Archive, ILLINOIS UNIV AT URBANA DEPT OF MATERIALS SCIENCE AND ENGINEERING, *CARBON, *THERMAL...
This project focuses on the interactions between plasmon-resonant-plasmonic- materials and structures and molecules, and how the coupling between plasmonic media can modify either molecular-excitonic properties. In this three year project we have demonstrated hot electron-induced photodissociation of H2 on Au nanoparticles at room temperature. The Au catalyst nanoparticles are embedded in TiO2 or SiO2 media and the role of the Au plasmon and the embedding media in the dissociation of H2 has...
Topics: DTIC Archive, RICE UNIV HOUSTON TX, *PLASMONS, FOUR WAVE MIXING, GOLD, HYDROGEN, NANOSTRUCTURES,...
We have developed a new way to build extremely small scale and accurate structures for contacting of nano-objects. The principle is based on the use of the atomic force microscope (AFM) for very accurate movement of pre-fabricated nano-objects, such as lift-off defined metal discs, aerosol fabricated nano-particles and colloidal gold particles. The assembly procedure consists of moving selected nanometer sized objects into a small gap between two metal electrodes.
Topics: DTIC Archive, Montelius, Lars, Carlsson, Sven-Bertil, Junno, Tobias, Magnusson, Martin, Deppert,...
Comparison of methanol photochemistry at three-dimensionally (3D) networked aerogels of TiO2 or Au-TiO2 reveals that incorporated Au nanoparticles strongly sensitize the oxide nanoarchitecture to visible light. Methanol dissociatively adsorbs at the surfaces of TiO2 and Au-TiO2 aerogels under dark, high-vacuum conditions. Upon irradiation of either ultraporous material with broadband UV light under anaerobic conditions, adsorbed methoxy groups act as hole-traps and extend conduction-band and...
Topics: DTIC Archive, NAVAL RESEARCH LAB WASHINGTON DC SURFACE CHEMISTRY BRANCH, *METHANOLS, *PHOTOCHEMICAL...
This paper reports the initial high power operation of a frequency doubling magnicon amplifier at 11.120 GHz. The deflection cavities operate at 5.560 GHz. The device is operating in a single pulse mode at 650 kV and 225 A, using a 5.5 -mm-diam. beam from a plasma cathode, at a magnetic field of 6.7-8.2 kG. In order to overcome a gain saturation problem in the deflection cavities caused by plasma loading, the penultimate deflection cavity is operated very close to self oscillation. The typical...
Topics: DTIC Archive, Gold, S. H., NAVAL RESEARCH LAB WASHINGTON DC RADIATION AND PARTICLE BEAM GENERATION...
This paper presents an experimental series that investigates dwell and interface defeat for bare brittle materials without any lateral confinement or cover plate system. Reverse impact experiments with gold rods and borosilicate glass targets with a small Cu buffer on top of the glass were performed. Interface defeat was observed simultaneously with five flash X-rays and a 16-picture high-speed optical camera. Experimental results show that the Cu buffer increases the velocity required for...
Topics: DTIC Archive, SOUTHWEST RESEARCH INST SAN ANTONIO TX, *COPPER, *PENETRATION, *GLASS, *GOLD, *IMPACT...
For data which take the form of a two-way contingency table, many authors have examined models other than the common model of independence of two classifications. In the literature are quasi independence models, clustered sampling models, intraclass models, and the Bradley-Terry model, parameters others. In order to estimate model parameters, iterative methods are required, and this leads to the problem of developing efficient algorithms.
Topics: DTIC Archive, Scott, David J, Wang, Qian D, BOND UNIV GOLD COAST (AUSTRALIA), *ALGORITHMS,...
Electrochemical and spectroelectrochemical data indicate that underpotentially deposited silver adatoms on gold substrates are photolyzed to form silver metal clusters. The surface gold-gold stretch and gold-silver stretch bands are observed, as well as the surface chloride complex stretch. The chloride complex interacts with ions in the solution phase giving rise to shifts in the metal-chloride stretching vibrational frequency as a function of the applied electrode potential. However, the...
Topics: DTIC Archive, Pons, Stanley, UTAH UNIV SALT LAKE CITY DEPT OF CHEMISTRY, *DEPOSITION, *GOLD,...
The potential-dependent C-N stretching mode, for thiocyanate adsorbed at the gold aqueous interface is examined by both surface enhanced Raman spectroscopy (SERS) and subtractively normalized interfacial Fourier transform infrared spectroscopy (SNIFTIRS). Both SERS and SNIFTIRS exhibit a C-N stretching band around 2120-2130 wavenumbers over the potential range +500 to -500 mV vs. s.c.e., consistent with the presence of a predominantly S-bound adsorbate. The potential-dependent C-N stretching...
Topics: DTIC Archive, Pons, Stanley, UTAH UNIV SALT LAKE CITY DEPT OF CHEMISTRY, *ADSORBATES, *ELECTRODES,...
Urinary catheters are the leading cause of nosocomical urinary tract infections (1). Moreover, the urinary tract infectious are the most common predisposing factor for fatal gram-negative sepsis that originate in hospitals. Unfortunately, even widespread use of antibodies to cure the infection has not been successful. Thus, with all of the existing catheter and drainage bag designs, there is still a major problem with catheter-related infection. The application of electrochemical technology to...
Topics: DTIC Archive, Rao, Gopalakrishna M, FRANK J SEILER RESEARCH LAB UNITED STATES AIR FORCE ACADEMY CO,...
This paper presents a simulation study of mode competition in highly overmoded gyrotron cavities. The parameters of the study have been selected to correspond to the approximate design parameters of a 280 GHz, 1 MW gyrotron at the Massachusetts Institute of Technology (MIT). The MIT gyrotron is designed to run in the TE+42,7 mode, using a 50 A, 84 keV electron beam, with a normalized beam radius of 0.6, and a beam alpha of 1.6. This study addresses 1) the problem of achieving gyrotron operation...
Topics: DTIC Archive, Gold, S H, NAVAL RESEARCH LAB WASHINGTON DC, *HIGH FREQUENCY, *GYROTRONS,...
Real time surface enhanced Raman spectra have been obtained for thin films of buckminsterfullerene (C60) on gold in acetonitrile during cyclic voltammetric potential excursions. At potentials where neutral C60 is stable, all ten normally active Raman bands are observed, along with three weaker features that are infrared active in the bulk phase vibrational spectra. Upon electroreduction to the C60 monoanion, several Raman-active bands downshift significantly in frequency, most prominently for...
Topics: DTIC Archive, Zhang, Y, PURDUE UNIV LAFAYETTE IN DEPT OF CHEMISTRY, *BANDS(STRIPS), REAL TIME,...
We have used the newly developed interfacial force microscope (EFM) to study the adhesive and mechanical properties of a Au substrate. We show that a W probe interacting with a Au surface results in plastic deformation under very small repulsive loads and transfers Au to the probe surface in a galling interaction upon removal. However, when the Au surface is passivated by a self-assembling monolayer of n-docosanethiol molecules (CH3(CH2)21SH), the substrate is able to elastically support large...
Topics: DTIC Archive, Thomas, Ross C, NEW MEXICO UNIV ALBUQUERQUE DEPT OF CHEMISTRY, *FILMS, *SUBSTRATES,...
This thesis considers the chemical interactions which occur at the interface of a polymer and a metal. Polyimides were chosen for this study because of their application in microelectronic devices, flexible interconnects, solar cells, and printed circuit boards. In these applications polyimide typically forms an interface with chromium, aluminum, copper, or gold. Numerous results have been published on the processes which occur when metals are deposited on cured polyimide. Less attention has...
Topics: DTIC Archive, Stewart, William C, AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH, *POLYIMIDE...
This report prepared to provide an analysis of the change from gold eutectic die attach integrated circuits (I.C.) to sliver-glass die attach I.C. for the M718/M741 remote antiarmor mine (RAAM). An overview of the contract history of the present RAAM electronic lens assembly (ELA) contractor, Accudyne Corporation of Janesville, WI, is presented. An outline of both the gold eutectic die attached process and the silver-glass die attach process is also given. The Government test plan for the die...
Topics: DTIC Archive, Printz, John, ARMY ARMAMENT RESEARCH DEVELOPMENT AND ENGINEERING CENTER PICATINNY...
We measured the X-ray apsorption spectrum from a half monolayer (as determined from the deposition charge) of Cu deposited on Au(III) in a sulfuric acid solution. The measurements were performed in situ, with the gold electrode immersed in solution, and at controlled potential. The exciting X-rays were incident at grazing angle and the spectrum was detected by measuring the fluorescence from the monolayer with an energy dispersive IIPGe detector. Spectra were obtained with the electric vector...
Topics: DTIC Archive, Gordon, J G, PUERTO RICO UNIV RIO PIEDRAS DEPT OF PHYSICS, *CONTROL, FLUORESCENCE,...
Long chain alkanethiols (HS(CH2)nX) adsorb from solution onto the surfaces of freshly evaporated copper, silver and gold films and form oriented monolayers. Both polar and non-polar tail groups (X) can be accommodated in these adsorptions. Adsorption on all three metals generates self-assembled monolayers (SAMs) exhibiting similar wetting properties, and thus, by inference, having related oriented structures. XPS data suggest that the omega-terminated eta-alkanethiolate monolayers, like those...
Topics: DTIC Archive, Laibinis, Paul E, HARVARD UNIV CAMBRIDGE MA DEPT OF CHEMISTRY, *POLAR REGIONS, TAIL...
A unique method for electrochemically depositing metal films from organic solutions was previously demonstrated. It was shown that by plating with this method, metallic particles and layers could be deposited on metals commonly used in the microelectronics industry. The deposition mechanism involved the dissolution of a less noble substrate metal and the simultaneous deposition of more noble metal particles on the surface of substrate, similar to immersion plating in aqueous solutions. This...
Topics: DTIC Archive, Dahlgren, E, MISSOURI UNIV-ROLLA DEPT OF METALLURGICAL ENGINEERING, *METAL FILMS,...
Chronocoulometry has been used in order to quantitatively characterize the energetics of pyridine adsorption onto a gold(100) single crystal electrode surface. Over the potential region investigated (-0.8 to +0.6 V), three orientations of the pyridine molecules on the gold surface have been observed. The pyridine orientation is strongly influenced by the electrode potential. At a positively charged surface, the pyridine assumes a vertical orientation with the nitrogen atom facing the gold...
Topics: DTIC Archive, Stolberg, L, WATERLOO UNIV (ONTARIO) DEPT OF CHEMISTRY, *ADSORPTION, *COULOMETERS,...
Nanowires grown via the popular vapor-liquid-solid (VLS) growth mechanism require nanodroplets, most often metal, such as gold, to catalyze the growth. As the size and density of the catalytic nanoparticles are the main parameters that define the properties of the resulting nanowires, controlling the growth of these nanoparticles is of particular importance. In this study, molecular beam epitaxy (MBE) was used to grow the nanoparticles on 100 and 211 silicon substrates. A layer of gold was...
Topics: DTIC Archive, ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE, *ANNEALING,...
The adsorption of pyridine onto both polycrystalline and single crystal gold electrode surfaces has been investigated using three electrochemical techniques: cyclic voltammetry, differential capacity and chronocoulometry. The surface concentration of pyridine, the Gibbs energy of adsorption, the electrosorption valency and the orientation of the pyridine molecules on the gold electrode surfaces, have been measured. All of these parameters were found to be sensitive to the structure of the gold...
Topics: DTIC Archive, Stolberg, L, GUELPH UNIV (ONTARIO) DEPT OF CHEMISTRY, *SURFACE REACTIONS, *PYRIDINES,...
The electrochemical and interfacial behavior of two types of electroactive self-assembled monolayer systems is investigated at gold electrodes. The first type is a ferrocene-based surfactant (a redox surfactant) derived from (dimethylamino)methylferrocene via quaternization of the amino group with various n-alkylbromides. These have a long alkyl chain with 16 or 18 carbons in the chain pendent from the cationic ammonium group. We refer to these as C16 and C18. The second type is a...
Topics: DTIC Archive, DeLong, Hugh C, WYOMING UNIV LARAMIE DEPT OF CHEMISTRY, *AMMONIUM COMPOUNDS,...
Long-chain aklanethiols absorb onto gold from solution and from monolayers. Coadsorption of HS(CH2)11OH and HS(CH2)21CH3 from ethanolic solutions of varying composition generates monolayers, the wettability of which is correlated closely with the composition of the monolayer. Absorption of the longer chain thiol is preferred over the short chain, and formation of monolayers comprising predominantly one component is favored over mixed monolayers containing both component thiols.
Topics: DTIC Archive, Bain, Colin D, HARVARD UNIV CAMBRIDGE MASS DEPT OF CHEMISTRY, *ABSORPTION, *GOLD,...
We have extended our application of electron spin resonance for the study of the silicon metal interface to include Gold, Aluminum, and Silver overlays. We present representative data for the observed broadening of the ESR linewidth for each of these metals applied to the silicon surface. As can be seen from these data, whereas strong spin coupling was found for Au and Al (comparable to our earlier results for Cu), we found no evidence of coupling for Ag. We believe these differences illustrate...
Topics: DTIC Archive, Schultz, Sheldon, CALIFORNIA UNIV SAN DIEGO LA JOLLA DEPT OF PHYSICS,...
This final report represents the results of controlled clinical studies involving 5,727 dental restorations in 1,154 patients which were placed under recorded standardized conditions and were assessed annually for 19 years. The restorations were evaluated by the PHS criteria and reasons for failure were also recorded. The longevity and modes of failure of composite resins, amalgam, base metal, and gold alloys were assessed by use of an Actuarial Life Table Survival Analysis procedure. The...
Topics: DTIC Archive, Lugassy, Armanad A, UNIVERSITY OF THE PACIFIC SAN FRANCISCO CA DEPT OF PHARMACOLOGY,...
Organic chemistry is largely derived from studies of the reactivity and properties of molecules in homogeneous solution, and much of the intuition of organic chemists is based on the behavior of molecules in solution. Surfaces and interfaces (that is, quasi two-dimensional assemblies of molecules or functional groups) provide environments that can be quite different from those of solutions, and chemical intuition derived from solution is often wrong when applied to processes occurring at...
Topics: DTIC Archive, Whitesides, George M, HARVARD UNIV CAMBRIDGE MA, *THIN FILMS, *SURFACE CHEMISTRY,...
Long-chain alkanethiols, HS(CH2)nX, adsorb from solution onto gold surfaces and form ordered, oriented monolayer films. The properties of the interfaces between the films and liquids are largely independent of chain length when n 10; in particular, wetting is not directly influenced by the proximity of the underlying gold substrate. The specific interaction of gold with sulfur and other soft nucleophiles and its low reactivity toward most hard acids and bases make it possible to vary the...
Topics: DTIC Archive, Whitesides, George M, HARVARD UNIV CAMBRIDGE MA DEPT OF CHEMISTRY, *THIOLS, *FILMS,...
Rate constants for homogeneous self exchange, kh(ex), and electrochemical exchange, ke(ex), have been measured for the first and second reduction steps of (eta 5-c5Me5) (eta 6-C6-Me6) M2+, where M = Rh and Co, in order to assess the manner in which the eta 6 yields eta 4 arene hapticity change observed upon formation of the Rh(I) two-electron reduction product is coupled with electron transfer. The analogous Co(III) / (II) / (I), mixed- sandwich system was chosen for comparison, because, unlike...
Topics: DTIC Archive, Nielson, R M, PURDUE UNIV LAFAYETTE IN DEPT OF CHEMISTRY, *ELECTRON TRANSFER,...
Topics: DTIC Archive, Kobrin, D M, FAIRCHILD CAMERA AND INSTRUMENT CORP MOUNTAIN VIEW CA FAIRCHILD...
Recent approaches to the problem of the gamma-ray laser have focused upon upconversion techniques in which metastable nuclei are pumped with long wavelength radiation. At the nuclear level the storage of energy can approach tera-Joules (10 to the 12tj power J) per liter for thousands of years. However, any plan to use such a resource for a gamma-ray laser poses problems of a broad interdisciplinary nature requiring the fusion of concepts taken from relatively unrelated fields of physics.
Topics: DTIC Archive, Collins, Carl B, TEXAS UNIV AT DALLAS RICHARDSON CENTER FOR QUANTUM ELECTRONICS AND...
Microelectrochemical methods are shown to be useful in determining the diffusivity of biological redox molecules. The electrochemistry of both ferri- and ferrocytochrome c has been examined at a microelectrode array using bis(4-pyridyl) ethylene as an electrocatalyst. Sigmoidal current-voltage scans are observed in the cyclic voltammometry typical of the cylindrical diffusion-limited response found for reversible redox couples at microelectrodes. The arrays used consist of eight gold...
Topics: DTIC Archive, Cammarata, Vince, MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF CHEMISTRY, *BIOLOGY,...
A summary of research findings is presented on a project to study the use of Molecular Beam Epitaxy Techniques in metallization of semiconductors such as Gallium Arsenide. Epitaxial metal layers of Niobium and Tantalum have been grown on sapphire and overlayers of Germanium, Gold, Copper and Cobalt have been deposited on (110) and (100) GaAs. The interfacial structure and defects have been studied using x-ray scattering and transmission electron microscopy. (aw)
Topics: DTIC Archive, Clarke, Roy, MICHIGAN UNIV ANN ARBOR HARRISON M RANDALL LAB OF PHYSICS, *THIN FILMS,...
The goal of this program is to investigate new dielectrics, metals and processes for the fabrication of multi-chip modules which hold the promise of exceptional electrical performance in the GHz region in addition to high yield and high reliability. The low dielectric constant insulators are being evaluated through the fabrication of in-situ test structures using gold as the metallization. In the course of doing this evaluation, a simple process for gold MCMs has been investigated. A processing...
Topics: DTIC Archive, Kohl, Paul, GEORGIA INST OF TECH ATLANTA SCHOOL OF CHEMICAL ENGINEERING, *METALS,...
Surface-enhanced Raman spectra of benzene and eight mono substituted benzenes adsorbed at gold electrodes have been examined in order to probe the nature of adsorbate-surface bonding for simple aromatic molecules. Benzene appears to adsorb flat via pi adsorbate-surface interactions as evidenced by the significant (20-30/cm) downshifts in the symmetric rig breathing mode (v sub 1) and the absence of other ring modes in the SER spectra. Similar results were obtained using gold surfaces prepared...
Topics: DTIC Archive, Gao, Ping, PURDUE UNIV LAFAYETTE IN DEPT OF CHEMISTRY, *BENZENE, *ADSORPTION, PROBES,...
The laser output power of TEM sub 00 mode from DC excitation slow-flow CO2 laser made of ceramic tubes is 1.45 times higher as that of the laser made of glade of glass tubes. The experimental results are better than the distributed coated Au film catalyst used for improving output property of DC exciting slow-flow CO2 laser by Mr. J. Macken. The mechanism of output power enhancement of the ceramic CO2 laser was discussed.
Topics: DTIC Archive, Gao, Yungui, NATIONAL AIR INTELLIGENCE CENTER WRIGHT-PATTERSON AFB OH, *EXCITATION,...
A procedure was developed for the routine monitoring of neutron dose absorbed by patients receiving x-ray therapy with high-energy electron accelerators. The source of the neutrons was photonuclear reactions. The detection system used to measure them is described. Three methods are described and compared for measuring the neutron flux by activation of thin gold foils. These included the cadmium-difference method for thermal flux determination, a cadmium-clad polyethylene moderator known to have...
Topics: DTIC Archive, Rossano, Mark J, AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF...
An improved Chem-Braze bonding system for attaching sintered abradable seals to compressor blade tip-shrouds was developed. The improved Chem-Braze system incorporates glycerin as an inhibitor to prevent premature evaporation which prolongs working life and allows adequate time to attach seals to engine hardware. Manufacturing guidelines including glycerin concentration, working environment, slurry thickness, bonding pressure, drying and curing parameters, and refurbishing techniques were...
Topics: DTIC Archive, McComas, Charles C, PRATT AND WHITNEY WEST PALM BEACH FL GOVERNMENT PRODUCTS DIV,...
Plasmas generated near conductor surfaces with MA/mm2 current density are diagnosed on Gamble II (1 MA/100 ns) for conditions relevant to a Z (20 MA/100 ns) wire-array z-pinch configuration. Plasma density greater than 1014 cm-3 is detected 1 mm from the conductor beginning 100 ns after the start of the current. The plasma expands with 2 cm/ s velocity. High-density (10(exp 17)-10 (exp 18) cm-3) plasma migrates more slowly ( 0.5 cm/micro s) away from the ribs. Three different rib cross sections...
Topics: DTIC Archive, NAVAL RESEARCH LAB WASHINGTON DC PLASMA PHYSICS DIV, *PLASMA DIAGNOSTICS, ACETONES,...
Gold nanowires were fabricated on the stepped MgO (100) surfaces. The stepped MgO (100) surfaces were produced by polishing (100) surfaces at an inclined angle approx. 1 deg. toward a 110 direction. An atomic force microscope image indicates that gold nanowires have grown at the steps on MgO (100) surface with a height of ^ 2 nm and a width of ^ 60 nm.
Topics: DTIC Archive, Ueda, Akira, Mu, Richard R., Saunders, Vanessa, Livingston, Thurston, Wu, Marvin H.,...
Topics: DTIC Archive, ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE,...
