| The Effect of Size Distribution on the Switching Field Distribution of Co/Pd Multilayered Nanostructure Arrays |
Aug-2008 |
3 pages |
| Authors:
Dmitri Litvinov; Darren Smith; James Rantschler; Paul Ruchhoeft; Sakhrat Khizroev; HOUSTON UNIV TX CENTER FOR NANOMAGNETIC SYSTEMS
|
 | We use Ion Beam Proximity Lithography (IBPL) to produce 4mm x 4mm arrays of 220 nm dots in perpendicularly-oriented Co/Pd multilayered media. IBPL is used to reduce the size distribution sigmaD of the arrays, and subsequently He+ ion irradiation is used to reduce their anisotropy. The Switching Field Distribution sigma(Hcr)/H(Cr) is measured for each sample before and after irradiation, and a linear relationship is experimentally found between sigma(Hcr)/H(Cr) and sigmaD. ... |
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| Deterministic Entangled Nanosource |
Aug-2008 |
10 pages |
| Authors:
Galina Khitrova; ARIZONA UNIV TUCSON
|
| During the three years of this grant, conclusions were reached that are important for the future of semiconductor cavity QED utilizing photonic crystal nanocavities. A new way was found to scan the cavity mode by condensation of xenon or nitrogen while keeping the quantum dot cold to minimize dephasing. Absorption was shown to reduce the cavity Q when the dot density is 400 per square micron. Lasing with a soft ... |
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| Modulation of Coulomb Blockade Behavior of Room Temperature Operational Single Electron Transistors by Tunnel Junction |
Aug-2008 |
5 pages |
| Authors:
P S Karre; Aditya Kapoor; Govind Mallick ;Shashi P Karna; Paul L Bergstrom; MICHIGAN TECHNOLOGICAL UNIV HOUGHTON DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
|
| The effect of tunneling oxide thickness on the Coulomb blockade behavior of a room temperature operating multi dot Single Electron Transistors (SET) was investigated. Our room temperature operational SETs, fabricated from focused ion beam deposited tungsten nano-islands, clearly show the modulation of Coulomb Blockade voltage with the change in the tunnel oxide thickness. The Coulomb blockade voltage of the device was increased from 2.0 V to 5.0 V by the ... |
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| Optically Defined Chemical Functionalization of Silicon Nanomechanical Resonators for Mass Sensing |
Aug-2008 |
5 pages |
| Authors:
Jeffrey W Baldwin; Maxim K Zalalutdinov; Bradford B Pate; Michael J Martin; Brian H Houston; NAVAL RESEARCH LAB WASHINGTON DC
|
| Nanomechanical resonators with their extremely small mass and high surface/volume ratio present a unique opportunity for mass sensing[1-4]. However, functionalization with selective vapor adsorptive functional groups has been an impediment to the realization of nanomechanical systems for mass sensing. Functional groups that adsorb analytes of interest should be patterned only on the nanoresonator itself, and should not be located on structural elements or micro-channel walls, which would greatly limit the ... |
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| Frequency Response of Nanoelectromechanical Cantilevers Operating in Fluid |
Aug-2008 |
5 pages |
| Authors:
Michael J Martin; Brian H Houston; NAVAL RESEARCH LAB WASHINGTON DC
|
| Nano-electro-mechanical resonators used for sensing, data storage, and nano-fabrication applications are often operated as feed-back control systems. To determine the transfer function of silicon cantilevers with a width of 5.0 micrometer, a thickness of 800 nm, and lengths of 10, 15, 30, and 45 micrometer, the damping in air and liquid was simulated numerically using an integrated fluidstructure solver. Bode diagrams and Nyquist plots of the cantilever transfer function indicate ... |
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| Characteristics of Surface-Normal Fano Filters on Flexible Plastic Substrates |
Aug-2008 |
4 pages |
| Authors:
Zexuan Qiang; Weidong Zhou; Zhenqiang Ma; Hongjun Yang; Li Chen; Huiqing Pang; Gail J Brown; TEXAS UNIV AT ARLINGTON NANOFAB CENTER
|
| We report here the angular and polarization dependent transmission characteristics of surface-normal optical filters based on Fano resonances on patterned single crystalline silicon nanomembranes (SiNM), which were fabricated and transferred onto transparent PET plastic substrates using a disruptive SiNM wet transfer process. The measured surface-normal and angle-dependent filter transmission results agree well with the design and simulation based on 3D finite-difference time-domain technique. |
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| Promises of Graphene Nanoelectronics |
Aug-2008 |
2 pages |
| Authors:
Chagaan Baatar; OFFICE OF NAVAL RESEARCH ARLINGTON VA
|
| Graphene is a single atomic layer of carbon atoms arranged into a two-dimensional (2D) hexagonal lattice. Since its discovery in 2004 by physicists [1], single layer graphene has been produced by many different methods and sample quality has steadily improved [2]-[4]. |
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| Inlaid Carbon Nanofiber Nanoelectrode Array as Highly Efficient Dielectrophoresis Device for Bacteria Trapping |
Aug-2008 |
3 pages |
| Authors:
Jun Li; HUA CHEN; Prabhu U Arumugam; Alan Cassell; KANSAS STATE UNIV MANHATTAN DEPT OF CHEMISTRY
|
| Dielectrophoresis (DEP) is an effective microelectronic technique for trapping and manipulating biological particles in a microfluidic environment, which relies on the highly asymmetric electric field gradient created by the microelectrodes. Here we demonstrate an AC DEP technique for single-bacteria trapping using nanoelectrode arrays (NEAs) in a points-and-lid configuration. The NEA is based on vertically aligned carbon nanofibers (CNFs) embedded in SiO2 matrix. The miniaturization of the electrode size provides a ... |
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| Evaluating Real-Time Platforms for Aircraft Prognostic Health Management Using Hardware-In-The-Loop |
Aug-2008 |
10 pages |
| Authors:
Mitch Wolff; Michael Corbett; Michael Boyd; Peter Lamm; Tommy Baudendistel; KRAUSE (P C) AND ASSOCIATES WEST LAFAYETTE IN
|
| Aircraft power demands continue to increase with the increase in electrical subsystems. These subsystems directly affect the behavior of the power and propulsion systems and can no longer be neglected or assumed linear in system analyses and prognostic health management (PHM) schemes. The complex models designed to integrate new capabilities have a high computational cost. Hardware-in-the-loop (HIL) is being used to investigate aircraft power systems by using a combination of ... |
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| Measurement of Antenna Gain with Transmitting and Receiving Antennas on a Finite Ground Plane |
25-Jul-2008 |
|
| Authors:
Edward E Altshuler; Terry H O'Donnell; AIR FORCE RESEARCH LAB HANSCOM AFB MA SENSORS DIRECTORATE/ELECTROMAGNETICS TECHNOLOGY DIV
|
 | The gain of an antenna is usually measured by placing a transmitting antenna in the far field of the antenna under test (AUT) and then comparing the power received by that antenna with that received by a reference antenna (RA). Rather than having a separate power source for the transmitter, it is convenient to utilize the two ports of a Hewlett-Packard 8510C Network Analyzer for the gain measurement. There are ... |
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| Bio-Nanotechnology Infrastructure and Technology Oriented Research |
17-Jul-2008 |
14 pages |
| Authors:
W K Jones; FLORIDA INTERNATIONAL UNIV MIAMI ADVANCED MATERIALS ENGINEERING RESEARCH INST (AMERI)
|
| FIU research concentrated in the following areas of development: nanoelectronics, bio-nanosensors, and nanomaterials, processes, and characterization. Five projects were supported: next generation information storage devices-both three-dimensional magnetic and protein-based, high power cold cathodes for microwave generators, carbon nanotube-based bio-sensors, silicon/polymer nanophotonics, and doped nanodiamonds and nanoceramic lasers for future devices. In magnetic storage devices, this work has resulted in patterned soft underlayer metallizations to localize the recording and sensitivity fields ... |
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| Manipulating Local Electronic Properties of Carbon Nanotubes |
16-Jul-2008 |
6 pages |
| Authors:
David Goldhaber-Gordon; STANFORD UNIV CA SPONSORED PROJECTS OFFICE
|
| Carbon nanotubes have many emerging technological uses, from strengthening lightweight composite materials to reducing voltage requirements in field-emission displays. Companies such as IBM and Intel have substantial research efforts aimed at the more complex task of building transistors and computer processors from nanotubes. Research under this proposal addresses one of the important requirements for achieving that vision: understanding and modifying electron flow in one-dimensional systems (carbon nanotubes) by local gating, ... |
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| Miniature High Density Scandate Cathodes for Linear Beam Devices |
14-Jul-2008 |
|
| Authors:
Arthur Carpenter; Bernard K Vancil; Ivor Brodie; E BEAM INC BEAVERTON OR
|
| The work was an investigation of recent promising results by workers in China on scandate impregnated cathodes. The improvement in dispenser cathode performance due to additions of small quantities of scandium oxide has been known since at least the 1980s. But workers in China have produced breakthrough performance with verified current loadings to 100 A/cm2. These results have not been fully reproduced or understood by cathode researchers in this country. ... |
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| Optical Pulse Interactions in Nonlinear Excited State Materials |
14-Jul-2008 |
|
| Authors:
Mary Potasek; David McLaughlin; Evgueni Parilov; NEW YORK UNIV NY COURANT INST OF MATHEMATICAL SCIENCES
|
| We cover five general areas: (1) optical limiting (2) organic multiphoton absorber (AFX) (3) numerical methods (4) relationship between the building blocks/decay rate matrix and the coupled propagation/rate equations and (5) semiconductor quantum dots. |
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| Many-Body Effects on Optical Carrier Cooling in Intrinsic Semiconductors at Low Lattice Temperatures |
11-Jul-2008 |
9 pages |
| Authors:
Danhong Huang; P M Alsing; AIR FORCE RESEARCH LAB KIRTLAND AFB NM SPACE VEHICLES DIRECTORATE
|
| Based on the coupled density and energy balance equations, a dynamical model is proposed for exploring many-body effects on optical carrier cooling not lattice cooling in steady state in comparison with the earlier findings of current-driven carrier cooling in doped semiconductors X. L. Lei and C. S. Ting, Phys. Rev. B 32, 1112 1985 and tunneling-driven carrier cooling through discrete levels of a quantum dot H. L. Edwards et al., ... |
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| Nanotechnology-Enabled Optical Molecular Imaging of Breast Cancer |
Jul-2008 |
93 pages |
| Authors:
Rebekah Drezek; RICE UNIV HOUSTON TX
|
| This project focuses on development of nanotechnology-enabled optical molecular imaging technologies for applications in breast cancer diagnosis and monitoring of therapeutic response. The project consists of two major efforts: (1) optical instrumentation technology development and (2) development of complementary engineered nanomaterials for use in conjunction with the instrumentation created to provide molecular specificity. A particularly significant effort is underway to develop needle-compatible fiber optic probes to enable in vivo imaging ... |
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| Transient Turbine Engine Modeling with Hardware-in-the-Loop Power Extraction (PREPRINT) |
Jul-2008 |
9 pages |
| Authors:
John McNichols; Michael A Boyd; J M Wolff; Philip R Owen; S D Phillips; Mark J Blackwelder; J Timothy; Michael W Corbett; Peter T Lamm; KRAUSE (P C) AND ASSOCIATES WEST LAFAYETTE IN
|
| Increasingly high aircraft power demands require that the interactions between an aircraft's electrical subsystem and the engine subsystem be considered in dynamic, system-level tests. Traditionally, system-level dynamics have only been captured in completely assembled aircraft systems. Component-level or subsystem-level optimization is no longer appropriate because highly interdependent dynamics between subsystems only become apparent during system-level analysis. In an effort to mitigate program risk, enable system-level optimization, and reduce the high ... |
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| Hardware-in-the-Loop Power Extraction Using Different Real-Time Platforms (PREPRINT) |
Jul-2008 |
9 pages |
| Authors:
Mitch Wolff; Michael Corbett; John McNichols; Peter Lamm; Caleb Barnes; Thomas Baudendistel; KRAUSE (P C) AND ASSOCIATES WEST LAFAYETTE IN
|
| Aircraft power demands continue to increase with the increase in electrical subsystems. These subsystems directly affect the behavior of the power and propulsion systems and can no longer be neglected or assumed linear in system analyses. The complex models designed to integrate new capabilities have a high computational cost. Hardware-in-the-loop (HIL) is being used to investigate aircraft power systems by using a combination of hardware and simulations. This paper considers ... |
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| Threats and Challenges in Reconfigurable Hardware Security |
Jul 2008 |
13 pages |
| Authors:
Ryan Kastner; Ted Huffmire; CALIFORNIA UNIV SAN DIEGO LA JOLLA DEPT OF COMPUTER SCIENCE AND ENGINEERING
|
| Computing systems designed using reconfigurable hardware are now used in many sensitive applications, where security is of utmost importance. Unfortunately, a strong notion of security is not currently present in FPGA hardware and software design flows. In the following, we discuss the security implications of using reconfigurable hardware in sensitive applications, and outline problems, attacks, solutions and topics for future research. |
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| High Performance Piezoelectric Airframes for Nano Air Vehicles |
30-Jun-2008 |
17 pages |
| Authors:
H Kommepalli; A Hirsh; C Rahn; S Tadigadapa; PENNSYLVANIA STATE UNIV UNIVERSITY PARK
|
| Currently, Unmanned Air Vehicles (UAVs) are too large to penetrate buildings for situational awareness and reconnaissance, emplace important sensors, and sample and return material. While a variety of Micro Air Vehicles have been built and flown that use propellers and flapping wings for lift generation, Nano Air Vehicles (NAVs), defined as weighing less than 10 grams with wingspans less than 7.5 cm, have yet to be flown. NAV-scale actuators and ... |
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| Effect of Anode Current Fluctuations on Ion Energy Distributions within a 600 W Hall Effect Thruster (Preprint) |
23-Jun-2008 |
11 pages |
| Authors:
Michael R Nakles; Hargus; William A Jr; Rachel Tedrake; Bruce Pote; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE
|
| This work presents axial ion energy distribution measurements within the acceleration channel of the 600 W Busek Co. Inc. BHT-HD-600 laboratory Hall thruster derived from laser-induced fluorescence measurements of the 5d[4](sub 7/2) - 6p[3](sub 5/2) xenon ion excited state transition. Acceleration channel centerline ion energy distributions are measured for three closely related operating conditions which only differ in the magnitude of the radial magnetic field strength. These three operating conditions ... |
|
| Electroluminescence Efficiency Enhancement using Metal Nanoparticles |
22-Jun-2008 |
4 pages |
| Authors:
Richard A Soref; J B Khurgin; G Sun; AIR FORCE RESEARCH LAB HANSCOM AFB MA SENSORS DIRECTORATE
|
| We apply the "effective mode volume" theory to evaluate enhancement of the electroluminescence efficiency of semiconductor emitters placed in the vicinity of isolated metal nanoparticles and their arrays. Using the example of an InGaN/GaN quantum-well active region positioned in close proximity to Ag nanospheres, we show that while the enhancement due to isolated metal nanoparticles is large, only modest enhancement can be obtained with ordered array of those particles. We ... |
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| Damping MEMS Devices in Harsh Environments Using Active Thin Films |
17-Jun-2008 |
26 pages |
| Authors:
Greg P Carman; Catherine A Kerrigan; CALIFORNIA UNIV LOS ANGELES DEPT OF MECHANICAL AND AEROSPACE ENGINEERING
|
| We report on fabrication and damping measurement of NiTi and Terfenol-D thin films. A model for prediction of the damping properties (tan delta) of a laminate using the material properties of the layers was developed. Damping properties in Nitinol thin film due only to residual stresses was measured to be as high as tan delta = 0.17 for large strain (0.9%). At lower strain levels a Nitinol/Silicon laminate was tested ... |
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| Design, Analysis and Construction of a High Voltage Capacitor Charging Supply |
01-Jun-2008 |
97 pages |
| Authors:
Nathan Tyler; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| The desire to use railguns in defense applications has elevated the level of concentration in all areas of the railgun system. Necessary in any railgun is a large amount of electric power to deliver the required force to the projectile. One popular source of power is high voltage capacitor banks. The NPS railgun Lab employs a fully functioning railgun with capacitor banks as power supplies. A reliable and safe charging ... |
|
| Very Small Satellite Design for Space Sensor Networks |
01-Jun-2008 |
233 pages |
| Authors:
David J Barnhart; SURREY UNIV GUILDFORD (UNITED KINGDOM) SURREY SPACE CENTRE
|
| An investigation of very small satellite miniaturisation techniques is presented, focusing on sub-kilogram technologies targeted at space sensor network applications. Distributed space mission concepts are emerging for scientific and remote sensing applications. This architecture will enable observation of real-time multi-point phenomena. Space economics and environmental concerns dictate a cost-effective mass-producible low-mass satellite for brief but essential missions in low Earth orbit. Very small satellite technologies have been investigated, assessed, and ... |
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| Automated Classification of Power Signals |
01-Jun-2008 |
|
| Authors:
Ethan R Proper; MASSACHUSETTS INST OF TECH CAMBRIDGE
|
| The Non-Intrusive Load Monitor (NILM) is a device that utilizes voltage and current measurements to monitor an entire system from a single reference point. The NILM and associated software convert the V/I signal to spectral power envelopes that can be searched to determine when a transient occurs. The identification of this signal can then be determined by an expert classifier and a series of these classifications can be used to ... |
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| Harmonic Approaches to Non-Intrusive Load Diagnostics |
01-Jun-2008 |
92 pages |
| Authors:
Ashley E Fuller; MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF MECHANICAL ENGINEERING
|
| The Non-Intrusive Load Monitor (NILM) is a system that monitors, records and processes voltage and current measurements to establish the operating characteristics of individual loads on a load center from a single aggregate measurement. The NILM can also be used to actively monitor degradation or diagnose specific system failures. Current NILM research conducted at the Massachusetts Institute of Technology's Laboratory for Electromagnetic and Electronic Systems (LEES) is exploring the application ... |
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| Development of Real Time Non-Intrusive Load Monitor for Shipboard Fluid Systems |
01-Jun-2008 |
107 pages |
| Authors:
Perry L Branch; MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF MECHANICAL ENGINEERING
|
| Since the year 2000, the United States Navy has spent an average of half a billion dollars over the congressionally approved budget for shipbuilding. Additionally, most experts project that in order to meet the Chief of Naval Operation's goal of a 313 ship Navy, the annual ship building budget will have to increase by about two thirds. Exacerbating this problem is the rising cost of maintaining the current inventory of ... |
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| Angiogenic Signaling in Living Breast Tumor Models |
01-Jun-2008 |
64 pages |
| Authors:
Edward Brown; ROCHESTER UNIV NY
|
| In this grant we propose to elucidate the signaling pathway that translates VEGFR activation into elevated vessel permeabiliW in endothelial cells within living breast tumor models. The working hypothesis is that the signaling pathway involved is a constitutively active form of the pathway shown for healthy mesenteric microvessels. Progress to date includes the training of personnel in the laboratory the completion of instrumentation development for a novel method for the ... |
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| Curvature Nonlinearity Measure and Filter Divergence Detector for Nonlinear Tracking Problems (Postprint) |
Jun-2008 |
9 pages |
| Authors:
Adnan Bubalo; Ruixin Niu; Pramod K Varshney; Mark Alford; Eric Jones; Maria Scalzo; AIR FORCE RESEARCH LAB ROME NY INFORMATION DIRECTORATE
|
| Experimental results show that for a weekly nonlinear tracking problem, the extended Kalman filter and the unscented Kalman filter are good choices, while a particle filter should be used for problems with strong nonlinearity. To quantitatively determine the nonlinearity of a nonlinear tracking problem, we propose two types of measures: one is the differential geometry curvature measure and the other is based on the normalized innovation squared (NIS) of the ... |
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| Improving Shipboard Applications of Non-Intrusive Load Monitoring |
Jun-2008 |
165 pages |
| Authors:
Richard A Jones; MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF MECHANICAL ENGINEERING
|
| The Non-Intrusive Load Monitor (NILM) measures equipment performance by measuring and analyzing the source power to the equipment at a single point in the electrical system. Previous studies have proven the usefulness of the NILM system in characterizing the state of mechanical systems onboard U.S. Coast Guard vessels and at the U.S. Navy's Land Based Engineering Site (LBES) in Philadelphia, Pennsylvania. This thesis seeks to augment the NILM system by ... |
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| Nanotechnology: A Policy Primer |
20-May-2008 |
|
| Authors:
John F Sargent; LIBRARY OF CONGRESS WASHINGTON DC CONGRESSIONAL RESEARCH SERVICE
|
| Nanoscale science, engineering and technology commonly referred to collectively as nanotechnology is believed by many to offer extraordinary economic and societal benefits. Congress has demonstrated continuing support for nanotechnology and has directed its attention primarily to three topics that may affect the realization of this hoped for potential: federal research and development (R&D) in nanotechnology; U.S. competitiveness; and environmental, health, and safety (EHS) concerns. This report provides an overview of ... |
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| Embedded RF Photonic Crystals as Routing and Processing Devices in Naval Aperstructures |
16-May-2008 |
16 pages |
| Authors:
Dennis W Prather; DELAWARE UNIV NEWARK
|
| The ability to rapidly detect and process radio frequency (RF) signals is of extreme importance in the modern warfare environment. As the use of the electromagnetic spectrum continues to expand, the technical requirements necessary to maintain such a critical ability becomes very challenging; additional requirements such as miniaturization of the system, reduction in power consumption and the miniaturization of signatures places even more stringent requirements on an already pressing problem. ... |
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| Nanotechnology and U.S. Competitiveness: Issues and Options |
15-May-2008 |
|
| Authors:
John F Sargent; LIBRARY OF CONGRESS WASHINGTON DC CONGRESSIONAL RESEARCH SERVICE
|
| The projected economic and societal benefits of nanotechnology have propelled global investments by nations and companies. The United States launched the first national nanotechnology initiative in 2000. Since then, more than 60 nations have launched similar initiatives. In 2006, global public investment in nanotechnology was estimated to be $6.4 billion, with an additional $6.0 billion provided by the private sector. More than 600 nanotechnology products are now in the market, ... |
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| Atom Interferometry on Atom Chips-A Novel Approach Towards Precision Inertial Navigation Systems (PINS) |
15-May-2008 |
|
| Authors:
Vladan Vuletic; Wolfgang Ketterle; Mara Prentiss; MASSACHUSETTS INST OF TECH CAMBRIDGE
|
| Considerable progress was made during the grant period toward establishing a chip based atom interferometer. At the beginning of the gBECi period, no coherent on-chip beam splitter had been demonstrated. During the funding period, we developed two area enclosing interferometers with demonstrated coherence preservation: one using optical pulses, the other one using RF dressed potentials. Technical improvements in the moving guide technique should provide a 1cm2 enclosed area in a ... |
|
| Investigation of the Current Turn-off Characteristics of a GTO Thyristor in an Inductive Pulse Forming Network |
02-May-2008 |
112 pages |
| Authors:
Gerald E Vineyard; NAVAL ACADEMY ANNAPOLIS MD DEPT OF ELECTRICAL ENGINEERING
|
| The project investigated of the current interruption capability of Gate Turn Off (GTO) thyristors, specifically, factors that had potential to increase the amount of current that could safely be turned off. A series of GTO thyristors were used in an inductive pulse forming circuit to interrupt varying amounts of current. The test circuit consisted of a high-voltage capacitor bank, a wire-wound inductor, the GTO thyristor with control circuitry, and instrumentation ... |
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| Fabrication Equipment for Periodic Material Assemblies and Ph Assemblies and Photonic Crystals (DURIP FY06) |
29-Apr-2008 |
25 pages |
| Authors:
Henk Verweij; John L Volakis; Ronald M Reano; OHIO STATE UNIV COLUMBUS ELECTROSCIENCE LAB
|
| This report describes the purchased equipment to establish two laboratories at the Ohio State Univ. for the fabrication of a novel class of periodic assemblies (PAs) intended to emulate anisotropic media. Such media have already been shown to lead to novel modes, leading to high gain antennas and much smaller RF components. In essence, the purchased equipment are intended to demonstrate a new paradigm in material development for RF applications. ... |
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| Ensemble Techniques for Determining Globally Optimal Designs for Problems with Broadly Stated Design Objectives |
27-Apr-2008 |
4 pages |
| Authors:
Chunming Wang; Gary I Rosen; UNIVERSITY OF SOUTHERN CALIFORNIA LOS ANGELES
|
| In this project we have investigated the use of global optimization techniques for device design problems in photonics and electronics. Using several concrete device design problems as guides, we have defined a sub-class of global optimization problems with high-dimensional design space as the main focus of our effort. We have evaluated optimization approaches including Genetic Algorithm and Simulated Annealing for this class of problems. This evaluation confirmed our previous experience ... |
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| Time-Reversal Based Range Extension Technique for Ultra-wideband (UWB) Sensors and Applications in Tactical Communications and Networking |
16-Apr-2008 |
67 pages |
| Authors:
Robert C Qiu; TENNESSEE TECHNOLOGICAL UNIV COOKEVILLE
|
| This technical report (quarterly) details the work for Office of Naval Research (ONR) by Tennessee Tech. The goal of this project jointly funded by ONR, NSF, and ARO is to build a general purpose testbed with time reversal capability at the transmitter side. The envisioned application is for UWB sensors and tactical communications in RF harsh environments where multipath is rich and can be exploited through the use of time ... |
|
| Spin-Precession Organic Magnetic Sensor |
11-Apr-2008 |
43 pages |
| Authors:
Srini Krishnamurthy; SRI INTERNATIONAL MENLO PARK CA
|
| The three major tasks we addressed in this project were to: (a) identify the issues for demonstration of a polymer-based spin-precession magnetic sensor; (b) develop theoretical and computational techniques to study the effect of the interface between ferromagnetic metal and polymers for FET applications; and (c) apply the existing light propagation codes to study transmission of 1.5 micron wavelength light through GaAs. We have completed all three tasks, and the ... |
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| Effects of Electronic Quantum Interference, Photonic-Crystal Cavity, Longitudinal Field and Surface-Plasmon- Polariton for Optical Amplification |
09-Apr-2008 |
15 pages |
| Authors:
Danhong Huang; D A Cardimona; Paul M Alsing; AIR FORCE RESEARCH LAB KIRTLAND AFB NM SPACE VEHICLES DIRECTORATE
|
| Some possibilities for coherent optical amplification of a normally-incident and weak radiation field are reviewed based on various physical mechanisms, such as electronic quantum interference induced by a coupling laser field in a three-level system, field enhancement through the cavity confinement of a radiation field in a photonic crystal and field concentration seen in a transmitted near field through a metallic surface grating due to excitation of surface-plasmon-polariton modes. Numerical ... |
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| Integrated Sensor Systems for UAS |
01-Apr-2008 |
14 pages |
| Authors:
Mark C Patterson; Anthony Brescia; ADVANCED CERAMICS RESEARCH TUCSON AZ
|
| The miniaturization of sensors has in recent years led to the ability to provide multiple sensor operations from a single Unmanned Aircraft System (UAS) platform. Multiple UAS platforms can be synchronized to link devices from separate UAS platforms thus proving a powerful capability for data collection, while opening up interesting opportunities in the way data is retrieved and used. A range of new sensors being investigated will be discussed with ... |
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| Gun Emittance of a Space Charge Limited Diode Due to Temperature Effects and Surface Roughness |
Apr-2008 |
3 pages |
| Authors:
Paul B Larsen; Antonsen; Thomas M Jr; Khanh T Nguyen; David K Abe; MARYLAND UNIV COLLEGE PARK
|
| The emittance of a space charge limited diode is investigated under thermal emission and with a simple surface roughness model. |
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| Advanced Electron Guns and Depressed Collectors Design and Optimization Using the MICHELLE / ANALYST Environment |
Apr-2008 |
3 pages |
| Authors:
Eric nelson; Ben Held; John Petillo; Baruch Levush; John DeFord; Dimitrios Panagos; STAAR INC MEQUON WI
|
| Next generation vacuum electron devices under development for millimeter and sub-millimeter wavelengths are often characterized by very small features that must be very precisely designed and manufactured for proper tube function and longevity. In this regime the need for automated physics-based optimization to aid the designer in meeting device performance specificaitons is much more critical than in larger, lower frequency devices where prototyping and experimentation are more readily performed. Recent ... |
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| Accurate Representation of Attenuation in Large-Signal Helix TWT Simulation Codes |
Apr-2008 |
3 pages |
| Authors:
Baruch Levush; David Chernin; Antonsen; Thomas M Jr; Demos Dialetis; NAVAL RESEARCH LAB WASHINGTON DC
|
| This paper reports on the results of a comparison study of the CHRISTINE one-dimensional helix traveling wave tube (TWT) simulation code with the small signal theory of a beam interacting with a slow wave supported by a sheath helix in the presence of loss to determine whether attenuation is treated with sufficient accuracy by the ad hoc model used in the CHRISTINE code. The study was motivated in part by ... |
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| Energy Losses in Simulated Relativistic Michigan A6 Magnetron with Shaped Cathode |
Apr-2008 |
2 pages |
| Authors:
Peter Mardahl; AIR FORCE RESEARCH LAB KIRTLAND AFB NM DIRECTED ENERGY DIRECTORATE
|
| Recently there has been much research interest in improving magnetron performance by employing various priming techniques, such as shaped cathodes and nonuniform magnetic fields. These priming techniques have been successfully applied to reduce magnetron noise and improve mode-locking and efficiency. Inserting a shaped cathode into the simulated Michigan magnetron yields a maximum efficiency (the radiofrequency (RF) output power for a cycle divided by the current times voltage input for that ... |
|
| Large-Signal Code TESLA: Current Status and Recent Development |
Apr-2008 |
3 pages |
| Authors:
Baruch Levush; Antonsen; Thomas M Jr; Khanh T Nguyen; David K Abe; Igor A Chernyavskiy; Alexander N Vlasov; Simon J Cooke; NAVAL RESEARCH LAB WASHINGTON DC
|
| The optimization and design of new high-power, high-efficiency klystron amplifiers relies increasingly on effective nonlinear simulation tools. One such tool is the large-signal code TESLA, which was successfully applied for the modeling of single-beam and multiple-beam klystron devices at the Naval Research Laboratory and which is now used by number of U.S. companies. TESLA is a highly efficient fully electromagnetic two-dimensional code that solves self-consistently the electromagnetic field equations (including ... |
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| Progress on Fabrication and Testing of the Omniguide Traveling-Wave Tube Structures |
Apr-2008 |
3 pages |
| Authors:
Evgenya I Smirnova; Bruce E Carlsten; Lawrence M Earley; LOS ALAMOS NATIONAL LAB NM
|
| We have designed, fabricated and tested with low power a novel W-band traveling-wave tube (TWT) structure based on a slow-wave cylindrically-symmetric photonic band gap (PBG) structure, or an omniguide. PBG TWT structures have great potential for very large bandwidth and linear dispersion. The omniguide structure was designed and fabricated with silica dielectric with a copper harness. Cold test results were found to be in excellent agreement with the design. A ... |
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| Numerical Models of Mode Interaction in Gyrotrons: Capabilities and Limitations |
Apr-2008 |
3 pages |
| Authors:
Baruch Levush; Antonsen; Thomas M Jr; Igor A Chernyavskiy; Alexander N Vlasov; Gregory S Nusinovich; James A McDonald; SCIENCE APPLICATIONS INTERNATIONAL CORP MCLEAN VA
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| Mode interaction in cylindrical and coaxial gyrotrons are simulated by gyrotron design code MAGY. Effectiveness and limitations of MAGY models for mode interaction in gyrotrons operating at higher order modes are discussed. Similarities and differences in mode competition process in cylindrical and coaxial gyrotrons are studied and discussed. |
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| High-perveance W-band Sheet-beam Electron Gun Design |
Apr-2008 |
3 pages |
| Authors:
John Petillo; Baruch Levush; Khanh T Nguyen; John Pasour; Edward L Wright; NAVAL RESEARCH LAB WASHINGTON DC VACUUM ELECTRONICS BRANCH
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| A design methodology for sheet-beam formation and solenoidal magnetic field transport is described, and a point design for a W-band amplifier gun and beam transport is presented. The gun topology flexibly permits adjustment of beam width to accommodate various interaction circuits while maintaining beam height. This topology has been employed in the design of a 19.5 kV, 3.6 A (1.32 micro-perv.) gun with beam final cross-section of approximately 4.2 mm ... |
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Electrical and Electronic Equipment
