209
209

Jun 15, 2011
06/11

by
Danilov, A. D

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No Abstract Available

Topics: CALIBRATING, SHOCK TUBES, FOURIER TRANSFORMATION, PRESSURE SENSORS

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183

May 30, 2011
05/11

by
Launius, Roger D

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This document is a selected annotated bibliography on martian exploration.

Topics: FREQUENCY DIVISION MULTIPLEXING, WAVEFORMS, DATA SYSTEMS, FOURIER TRANSFORMATION, DISCRETE FUNCTIONS

181
181

May 22, 2011
05/11

by
Shyy, Wei; Thakur, Siddharth; Tucker, Kevi

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Convection effect and source terms are two primary sources of difficulties in computing turbulent reacting flows typically encountered in propulsion devices. The present work intends to elucidate the individual as well as the collective roles of convection and source terms in the fluid flow equations, and to devise appropriate treatments and implementations to improve our current capability of predicting such flows. A controlled variation scheme (CVS) has been under development in the context...

Topics: FOURIER TRANSFORMATION, LORENTZ TRANSFORMATIONS, OPERATORS (MATHEMATICS), QUANTUM MECHANICS,...

467
467

Sep 20, 2010
09/10

by
NON

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An efficient aerodynamic shape optimization method based on a computational fluid dynamics/sensitivity analysis algorithm has been developed which determines automatically the geometrical definition of an optimal surface starting from any initial arbitrary geometry. This method is not limited to any number of design variables or to any class of surfaces for shape definition.

Topics: ALGEBRA, CODING, COMPUTERS, FOURIER TRANSFORMATION, VIRTUAL MEMORY SYSTEMS, ALGORITHMS, FORTRAN

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327

Jun 21, 2010
06/10

by
Rossow, V. J

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Observations of waterspouts and their parent clouds

Topics: DATA CORRELATION, DIGITAL FILTERS, COMPUTER PROGRAMMING, FOURIER TRANSFORMATION, FREQUENCY RANGES,...

140
140

Jun 11, 2011
06/11

by
Thompson, Anne M.; Witte, Jacqueline C.; Smit, Herman G. J.; Oltmans, Samuel J.; Johnson, Bryan J.; Kirchhoff, Volker W. J. H.; Schmidlin, Francis J

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Abstract: Since 1998 the Southern Hemisphere ADditional OZonesondes (SHADOZ) project has collected more than 2000 ozone profiles from a dozen tropical and subtropical sites using balloon-borne electrochemical concentration cell (ECC) ozonesondes. The data (with accompanying pressure-temperature-humidity soundings) are archived. Analysis of ozonesonde imprecision within the SHADOZ dataset revealed that variations in ozonesonde technique could lead to station-to-station biases in the...

Topics: ASTRONOMICAL INTERFEROMETRY, MICHELSON INTERFEROMETERS, DATA PROCESSING, FOURIER TRANSFORMATION,...

493
493

Jun 21, 2010
06/10

by
Pugibet, M., et al

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Hydrogen peroxide as oxidizer in hybrid propellant rocket engines

Topics: ATMOSPHERIC CIRCULATION, BEAMS (RADIATION), CROSS CORRELATION, SPECTRUM ANALYSIS, FOURIER...

204
204

May 22, 2011
05/11

by
Hah, C.; Loellbach, J.; Greenwald, D. A.; Griffin, L.; Ruf, J

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A three-dimensional numerical method has been developed to analyze the complex flow field inside a turbine volute. Comparisons are made between solutions with different boundary conditions.

Topics: FOURIER TRANSFORMATION, HARMONIC OSCILLATION, ORTHOGONAL FUNCTIONS, POLYNOMIALS, WAVE FUNCTIONS,...

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282

Jun 3, 2011
06/11

by
Sokol, Jeff; Krishnan, Satish; Ayari, Laouce

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The High Gain Antenna Assemblies built for the 2003-2004 Mars Exploration Rover (MER) missions provide the primary communication link for the Rovers once they arrive on Mars. The High Gain Antenna Gimbal (HGAG) portion of the assembly is a two-axis gimbal that provides the structural support, pointing, and tracking for the High Gain Antenna (HGA). The MER mission requirements provided some unique design challenges for the HGAG. This paper describes all the major subsystems of the HGAG that were...

Topics: MICROWAVE INTERFEROMETERS, FOURIER TRANSFORMATION, IMAGING TECHNIQUES, MICROWAVE IMAGERY, THEOREMS,...

The Fourier-ray method involves ray tracing in a Fourier-transform domain. The ray solutions are then Fourier synthesized to produce a spatial solution. Here previous steady-state developments of the Fourier-ray method are extended to include a transient source of mountain waves. The method is illustrated with an initial value problem in which the background flow is started abruptly from rest and then maintained at steady velocity. The resulting wave transience is modeled in a simple way. All...

Topics: DTIC Archive, NAVAL RESEARCH LAB WASHINGTON DC, *RAY TRACING, FOURIER TRANSFORMATION, STEADY STATE,...

Averaging lemmas arise in the study of regularity of solutions to nonlinear transport equations. The present paper shows how techniques from Harmonic Analysis, such as wavelet decompositions, maximal functions, and interpolation, can be used to prove averaging lemmas and to establish their sharpness.

Topics: DTIC Archive, SOUTH CAROLINA UNIV COLUMBIA DEPT OF MATHEMATICS, *HARMONIC ANALYSIS, BOLTZMANN...

374
374

May 28, 2011
05/11

by
Stengle, Thomas; Flores-Amaya, Felip

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This document summarizes the major activities and accomplishments carried out by the Goddard Space Flight Center (GSFC)'s Flight Dynamics Analysis Branch (FDAB), Code 572, in support of flight projects and technology development initiatives in Fiscal Year (FY) 1999. The document is intended to serve as both an introduction to the type of support carried out by the FDAB (Flight Dynamics Analysis Branch), as well as a concise reference summarizing key analysis results and mission experience...

Topics: SIGNAL PROCESSING, VERY LARGE SCALE INTEGRATION, SYSTOLIC ARRAYS, PARALLEL PROCESSING (COMPUTERS),...

259
259

Jun 3, 2011
06/11

by
Prabhu, Ramadas K.; FRO

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Inviscid aerodynamic characteristics of the Space Shuttle Orbiter were computed in support of the Columbia Accident Investigation. The unstructured grid software FELISA was used and computations were done using freestream conditions corresponding to those in the NASA Langley 20-Inch Mach 6 CF4 tunnel test section. The angle of attack was held constant at 40 degrees. The baseline (undamaged) configuration and a large number of damaged configurations of the Orbiter were studied. Most of the...

Topics: INFRARED SPECTROMETERS, FOURIER TRANSFORMATION, LINEAR SYSTEMS, OPTICAL PATHS, INTERFEROMETERS,...

324
324

Aug 2, 2010
08/10

by
Thompson, Randolph C.; Richards, W. Lanc

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The buckling characteristics of a titanium matrix composite hat-stiffened panel were experimentally examined for various combinations of thermal and mechanical loads. Panel failure was prevented by maintaining the applied loads below real-time critical buckling predictions. The test techniques used to apply the loads, minimize boundary were shown to compare well with a finite-element buckling analysis for previous panels. Comparisons between test predictions and analysis for this panel are...

Topics: ATMOSPHERIC COMPOSITION, HIGH RESOLUTION, LOW NOISE, SPECTRAL RESOLUTION, SPECTROSCOPIC ANALYSIS,...

258
258

Jun 21, 2010
06/10

by
NON

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Deep Space Stations configured as phase sensitive interferometer to measure apparent change in angular separation between radio sources near time of occultation by sun

Topics: JET FLOW, SHEAR LAYERS, STRATA, CLEAR AIR TURBULENCE, DIFFERENTIAL EQUATIONS, FOURIER...

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42

Apr 5, 2017
04/17

by
N. Murugendrappa and A.G Ananth

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A new method forAdaptive Interference Cancellation (AIC) is proposed. The fractional domine concepts are adopted with Fractional Fourier Transformation (FFT) techniques. The Blocked LMS algorithm (BLMS) are used to show that the BER (Bit Error Rate) achieved is better than the direct adaptive filter method in FFT domine and also for other filtering methods. The performance of adoptive filtering method in fractional domine using blocked LMS algorithms shows asignificant improvement in the SNR ~...

Topics: Adaptive Interference Cancellation (AIC), Fractional Fourier transformation (FRFT), Signal to Noise...

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48K

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Instructor: Alan V. Oppenheim Set of 20 video lectures for Signals and Systems, an introductory course in analog and digital signal processing, including seismic data processing, communications, speech processing, image processing, consumer electronics, and defense electronics. View the complete course: http://ocw.mit.edu/RES6-008S11 License: Creative Commons BY-NC-SA More information at http://ocw.mit.edu/terms More courses at http://ocw.mit.edu

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Topics: signal processing, analog systems, digital systems, feedback, discrete-time signals,...

This paper addresses the problem that in many cases, observations cannot provide complete fields of the measured quantities, because they yield data only along a single cross-section through the examined fields. The paper describes a new Fourier-adjustment technique that allows existing fractal models to build realistic surroundings to the measured cross-sections. This new approach allows more representative calculations of cloud radiative processes and may be used in other areas as well.

Topics: NASA Technical Reports Server (NTRS), STOCHASTIC PROCESSES, CROSS SECTIONS, FOURIER TRANSFORMATION,...

The grant award was used to purchase and install an Anasazi 90-MHz Fourier Transform NMR to bring NMR capability, a cornerstone technique for organic chemists, to the Department of Natural Science which previously did not have NMR capability. The Eft FT NMR software system consist of two programs: WinPNMR, a data acquisition program and NUTS (Acorn NMR Inc.) A NMR Data Processing program for the processing of 1D and 2D experiments including COSY, DEPT, HETCOR, T1, T2 and kinetics. In addition...

Topics: DTIC Archive, BOWIE STATE COLL MD, *FOURIER TRANSFORMATION, *NUCLEAR MAGNETIC RESONANCE, COMPUTER...

An efficient method for calculating the contact boundary and interfacial pressure distribution was developed. This solution technique utilizes the discrete Fourier transform to establish an influence coefficient matrix for the portion of the pressurized tire surface that may be in the contact region. This matrix is used in a linear algebra algorithm to determine the contact boundary and the array of forces within the boundary that are necessary to hold the tire in equilibrium against a...

Topics: NASA Technical Reports Server (NTRS), PRESSURE DISTRIBUTION, TIRES, ALGORITHMS, FOURIER...

215
215

Jun 21, 2010
06/10

by
NON

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No Abstract Available

Topics: COMPUTATION, EQUATIONS OF MOTION, PERTURBATION, FOURIER SERIES, FOURIER TRANSFORMATION, JACOBI...

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353

Jun 9, 2011
06/11

by
Bertelsen, William D.; Shin, E. eugene; Thesken, John C.; Sutter, James K.; Martin, Ric

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THe objectives are: 1. To experimentally validate bi-axial plate flexural performance of PMC-Ti H/C-A286 sandwich panels for the internally pressurized RBCC combustion chamber support structure. 2. To explore ASTM 2-D plate flexure test (D 6416) to simulate the internal pressure loading and to correlate the results with analytical and FE modeling based on 2-D flexure properties.

Topics: THERMOGRAPHY, FOURIER TRANSFORMATION, PHASE CONTRAST, IMAGE PROCESSING, THREE DIMENSIONAL MODELS,...

The Finite Fourier Transformation matrix (F.F.T.) plays a central role in the formulation of quantum mechanics in a finite dimensional space studied by the author over the past couple of decades. An outstanding problem which still remains open is to find a complete basis for F.F.T. In this paper we suggest a simple algorithm to find the eigenvectors of F.T.T.

Topics: NASA Technical Reports Server (NTRS), ALGORITHMS, EIGENVECTORS, FOURIER TRANSFORMATION,...

A computational study of the effects of a wing fence on the T-38 Talon was performed. RANS simulations were conducted using the CFD solver AVUS to examine the flow around the T-38 and the fence at a Reynolds number of 10 million. The T-38 was modeled as a half aircraft with a symmetry plane down the center line and did not include the empennage. The engine inlet and exhaust were modeled as sink and source boundary conditions using mass flow and pressure specifications. Two fence geometries...

Topics: DTIC Archive, Bera, Debajyoti, BOSTON UNIV MA DEPT OF COMPUTER SCIENCE, *QUANTUM COMPUTING, FOURIER...

We present orbital parameters for six double-lined spectroscopic binaries (iota Pegasi, omega Draconis, 12 Bootis, V1143 Cygni, beta Aurigae, and Mizar A) and two double-lined triple star systems (kappa Pegasi and eta Virginis). The orbital fits are based upon high-precision radial velocity (RV) observations made with a dispersed Fourier Transform Spectrograph, or dFTS, a new instrument that combines interferometric and dispersive elements. For some of the double-lined binaries with known...

Topics: DTIC Archive, NAVAL OBSERVATORY FLAGSTAFF AZ, *BINARY STARS, REPRINTS, RADIAL VELOCITY,...

The basic concept of aliasing is this: Converting analog data into digital data requires sampling the signal at a specific rate, known as the sampling frequency. The result of this conversion process is a new function, which is a sequence of digital samples. This new function has a frequency spectrum, which contains all the frequency components of the original signal. The Fourier transform mathematics of this process show that the frequency spectrum of the sequence of digital samples consists...

Topics: NASA Technical Reports Server (NTRS), ANALOG DATA, DIGITAL DATA, SIGNAL PROCESSING, FOURIER...

195
195

Jul 6, 2010
07/10

by
BARRENSCHEEN, H. K.; BECKH-WODMANSTETTER, H. A

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BLONDLOT-DUSART TESTS ON PUTRID BLOOD GIVE IRREPROACHABLE PROOF THAT BACTERIA UNDER ANAEROBIC CONDITIONS AT SUITABLE TEMPERATURE ARE CAPABLE OF REDUCING ORGANICALLY BOUND PHOSPHORIC ACID SUFFICIENTLY SO AS TO OBTAIN A POSITIVE REACTION. EXPERIMENTS PERFORMED ON HUMAN OR CANINE BLOOD OBTAINED UNDER STERILE PRECAUTIONS PROVE COMPLETELY NEGATIVE AND IT IS CONCLUDED THAT THE OPTIONAL ANAEROBIANTS EXAMINED - AND BELONGING TO THE PROTEUS GROUP - ARE BY THEMSELVES NOT CAPABLE FOR THE REDUCTION OF...

Topics: CLOUD PHOTOGRAPHS, NIMBUS 4 SATELLITE, WIND (METEOROLOGY), CROSS CORRELATION, ERROR ANALYSIS,...

1,271
1.3K

Jul 11, 2010
07/10

by
Hunt, G. L

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No Abstract Available

Topics: RANDOM PROCESSES, WHITE NOISE, ALGORITHMS, BROADBAND, COMPUTERIZED SIMULATION, FOURIER...

Click here to view the University of Florida catalog record

Topics: Mass spectrometry, Ion cyclotron, Ion cyclotron resonance spectrometry, Fourier transformation,...

A complete characterization is given of closed shift-invariant subspaces of which provide a specified approximation order. When such a space is principal (i.e., generated by a single function), then this characterization is in terms of the Fourier transform of the generator. As a special case, we obtain the classical Strang-Fix conditions, but without requiring the generating function to decay at infinity. The approximation order of a general closed shift-invariant space is shown to be already...

Topics: DTIC Archive, DE Boor, Carl, WISCONSIN UNIV-MADISON CENTER FOR MATHEMATICAL SCIENCES, *FOURIER...

480
480

May 31, 2011
05/11

by
Smitherman, David; Fikes, John; Roy, Stephanie; Henley, Mark W.; Potter, Seth D

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In 2000 and 2001 studies were conducted at the NASA Marshall Space Flight Center on the technical requirements and commercial potential for propellant production depots in low Earth orbit (LEO) to support future commercial, NASA, and other Agency missions. Results indicate that propellant production depots appear to be technically feasible given continued technology development, and there is a substantial growing market that depots could support. Systems studies showed that the most expensive...

Topics: ALGORITHMS, DIFFRACTION PATTERNS, FRICTION MEASUREMENT, SKIN FRICTION, DETECTION, FOURIER...

269
269

Sep 20, 2010
09/10

by
Moitra, Stuti; Tennille, Geoffrey M.; Lakeotes, Christopher D.; Randall, Donald P.; Arthur, Jarvis J.; Hammond, Dana P.; Mall, Gerald H

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This document gives a brief overview of parallel software tools available on the Intel iPSC/860 parallel computer at Langley Research Center. It is intended to provide a source of information that is somewhat more concise than vendor-supplied material on the purpose and use of various tools. Each of the chapters on tools is organized in a similar manner covering an overview of the functionality, access information, how to effectively use the tool, observations about the tool and how it compares...

Topics: HARMONIC OSCILLATORS, HEISENBERG THEORY, QUANTUM MECHANICS, EIGENVECTORS, FOURIER TRANSFORMATION,...

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152

Jun 21, 2010
06/10

by
Bailey, H. E.; Fuller, F. B.; Lomax, H

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Numerical difficulties in integrating equations for one dimensional nonequilibrium nozzle flow of gas

Topics: SPACECRAFT, STRUCTURAL ANALYSIS, TRANSFER FUNCTIONS, DYNAMIC RESPONSE, FOURIER TRANSFORMATION,...

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712

Jul 11, 2010
07/10

by
POLYAKHOVA, Y. N

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A DETAILED SELECTION OF PROBLEMS ON THE DYNAMICS OF THE MOTION OF A MATERIAL POINT ACTED ON BY A CENTRAL GRAVITATIONAL FORCE, IN PARTICULAR, THE DYNAMICS OF SPACE FLIGHT IS PRESENTED ALONG WITH SEVERAL PROBLEMS ON THE MOTION OF A POINT ACTED ON BY CENTRAL NONGRAVITATIONAL FORCES. TOPICS COVERED INCLUDE KEPLER'S LAWS, BINET'S FORMULAS FOR CENTRAL FORCES, THE ENERGY BALANCE AND VELOCITY ALONG A SPACE TRAJECTORY, TIME OF MOTION ALONG A SPACE TRAJECTORY, CONDITIONS FOR THE EXISTENCE OF ELLIPTICAL...

Topics: LATTICE PARAMETERS, POISSON EQUATION, SOLID STATE PHYSICS, SUM RULES, CESIUM COMPOUNDS, CHLORIDES,...

Lossy pulse-echo ultrasonic image compression by a JPEG baseline system is permitted by DICOM. In addition to the use of JPEG, use of JPEG2000 will be approved in the near future. The main features of JPEG2000 are use of wavelet transform and ROI (Region of Interest) method. It is expected that wavelet transform is more effective than Fourier transform for ultrasonic echo signal/image processing. Furthermore, ROI method seems to be appropriate compression method of medical images. The purpose...

Topics: DTIC Archive, Hamamoto, Kazuhiko, TOKAI UNIV HIRATSUKA (JAPAN), *IMAGE COMPRESSION, FOURIER...

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170

May 23, 2011
05/11

by
Zhang, Kaixi; Zhao, Qingxun; Cui, Zhiyun; Zhar, Ping; Dong, Lifan

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In this paper, by the use of quantum biology and quantum optics, the laser induced potential variation of cell membrane has been studied. Theoretically, we have found a method of calculating the monophoton and multiphoton processes in the formation of the anomalous potential of cell membrane. In contrast with the experimental results, our numerical result is in the same order. Therefore, we have found the possibility of cancer caused by the laser induced anomalous cell potential.

Topics: QUANTUM MECHANICS, WAVE FUNCTIONS, FOURIER TRANSFORMATION, VELOCITY, VELOCITY MEASUREMENT, PARTICLE...

The long-term goals of Radiance in a Dynamic Ocean (RaDyO): Radiance and Visibility as Affected by Inherent Optical Properties (award number N0001409C0443) and Imaging System Performance and Visibility as Affected by the Physical Environment were to perform detailed investigations of inherent optical properties (IOPs) and the effects of IOP variability on underwater radiance and visibility and to investigate the relationships between physical forcing and optical properties, including the...

Topics: DTIC Archive, SEA ENGINEERING INC SANTA CRUZ CA, *OCEAN ENVIRONMENTS, *OPTICAL PROPERTIES,...

Discrete wavelet analysis is described through the dilation equation approach. A practical implementation of these techniques is developed and the resulting computer software is included as an appendix.

Topics: DTIC Archive, Coleman, C J, SURVEILLANCE RESEARCH LAB SALISBURY (AUSTRALIA), *FOURIER...

High resolution power spectra of 77 years of Zurich daily sunspot numbers were computed using various lags and data point intervals. Major harmonic peaks of the approximately 124-month period showed up strongly as well as the 27-day solar rotational period.

Topics: NASA Technical Reports Server (NTRS), POWER SPECTRA, SOLAR ACTIVITY, SUNSPOTS, FOURIER...

Causal solutions for effective relative complex permittivities of plasmas are derived. Both lossless and lossy plasmas are considered.

Topics: NASA Technical Reports Server (NTRS), CAUSES, MATHEMATICAL MODELS, PERMITTIVITY, PLASMAS (PHYSICS),...

This project had two major objectives. The first objective was to demonstrate nonreal time generation of ambiguity functions from one dimensional input transducers. The second objective was to design front end and rear end electronics capable of supporting real time operation of the optical processor. Both of these objectives were successfully achieved, and in addition, a new optical architecture was invented (LIPS), and its feasibility and superiority was experimentally demonstrated. The...

Topics: DTIC Archive, HONEYWELL CORPORATE MATERIAL SCIENCES CENTER BLOOMINGTON MN, *OPTICAL PROCESSING,...

Operator angle-action variables are studied in the frame of the SU(2) algebra, and their eigenstates and coherent states are discussed. The quantum mechanical addition of action-angle variables is shown to lead to a noncommutative Hopf algebra. The group contraction is used to make the connection with the harmonic oscillator.

Topics: NASA Technical Reports Server (NTRS), HARMONIC OSCILLATORS, HEISENBERG THEORY, QUANTUM MECHANICS,...

On November 23, 2011 International Space Station Guidance, Navigation, and Control reported unusual pitch rate disturbance. These disturbances were an order of magnitude greater than nominal rates. The Loads and Dynamics team was asked to review and analyze current accelerometer data to investigate this disturbance. This paper will cover the investigation process under taken by the Loads and Dynamics group. It will detail the accelerometers used and analysis performed. The analysis included...

Topics: NASA Technical Reports Server (NTRS), ACCELEROMETERS, INTERNATIONAL SPACE STATION, PITCHING...

Vapors from solid and powdered carbon, emitted from an oven cycled between 2000 and 3000 K, were co-condensed with argon onto a CsI substrate maintained at 10 K. The cycling process produced a multilayered matrix with regions of high carbon density alternating with layers of argon. FTIR measurements including complete 13C isotopic data, supported by ab initio calculations, allow the assignment of a band observed at 1817.8 cm(-1) to the v12(eu) fundamental of cyclic C8, correcting an erroneous...

Topics: DTIC Archive, Presilla-Marquez, Jose D, SCHAFER CORP CALABASAS CA, *CRYOGENIC PROPELLANTS,...

A Ramanujan-type representation for the Askey-Wilson q-beta integral, admitting the transformation q to q(exp -1), is obtained. Orthogonality of the Askey-Wilson polynomials with respect to a measure, entering into this representation, is proved. A simple way of evaluating the Askey-Wilson q-beta integral is also given.

Topics: NASA Technical Reports Server (NTRS), FOURIER TRANSFORMATION, HARMONIC OSCILLATION, ORTHOGONAL...

272
272

May 23, 2011
05/11

by
Pellis, Neal R.; Duray, Paul H.; Hatfill, Steven J

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Attempts to simulate normal tissue micro-environments in vitro have been thwarted by the complexity and plasticity of the extracellular matrix, which is important in regulating cytoskeletal and nuclear matrix proteins. Gravity is one of the problems, tending to separate components that should be kept together. For space shuttle experiments, NASA engineers devised a double-walled rotating bioreactor, which is proving to be a useful tissue culture device on earth as well as in space.

Topics: NOCTURNAL VARIATIONS, HARMONIC ANALYSIS, OSCILLATIONS, MESOSPHERE, HYDROXYL EMISSION, FOURIER...

We study the collapse of ultracold fermionic gases into inhomogeneous states due to strong dipolar interaction in both 2D and 3D. Depending on the dimensionality, we find that two different types of inhomogeneous states are stabilized once the dipole moment reaches a critical value d d(sub c): the stripe phase and phase separation between high and low densities. In 2D, we prove that the stripe phase is always favored for d greater than or approximate to d(sub c), regardless of the microscopic...

Topics: DTIC Archive, MARYLAND UNIV COLLEGE PARK DEPT OF PHYSICS, *ELECTRON GAS, DIPOLAR IONS, FOURIER...

The first phase of a research project directed toward development of a high speed automatic process to be used to match gun barrel signatures imparted to fired bullets was documented. An optical projection technique has been devised to produce and photograph a planar image of the entire signature, and the phototransparency produced is subjected to analysis using digital Fourier transform techniques. The success of this approach appears to be limited primarily by the accuracy of the photographic...

Topics: NASA Technical Reports Server (NTRS), IDENTIFYING, INTERIOR BALLISTICS, PROJECTILES, SIGNATURE...

A simultaneous-frequency nonlinear radar is presented for detecting radio frequency electronic targets of interest. The radar transmits 20 frequencies (tones) between 890 and 966 MHz, at approximately equal amplitudes and evenly spaced 4 MHz apart. The radar transceiver and the target are connected by coaxial cabling as a hardware simulation of a wireless channel. The radar receives intermodulation produced by these 20 frequencies, in a 90-MHz band just below 890 MHz and another 90-MHz band...

Topics: DTIC Archive, ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE, *RADAR,...

It is demonstrated that an angular Fourier transformation is obtained by making a rotation around the non-compact axis of So(2,1), the Lorentz group in three dimensions.

Topics: NASA Technical Reports Server (NTRS), FOURIER TRANSFORMATION, LORENTZ TRANSFORMATIONS, OPERATORS...