Radiowave scintillation in the presence of ionospheric disturbances has the potential to disrupt numerous transionospheric radio and radar systems. This report describes development of a model characterizing the plasma density irregularities that produce scintillation in the naturally disturbed mid latitude F layer. The model will be incorporated into Program WBMOD, which includes subroutines for computing both link geometry and scintillation indices, the latter by means of phase screen...
Topics: DTIC Archive, Robins,Robert E, NORTHWEST RESEARCH ASSOCIATES INC BELLEVUE WA, *IONOSPHERIC...
This paper attempts to place bilingual schooling in a sociolinguistic context by relating language use in school to language use in the community. The city treated here, Redwood City, California, has a growing Mexican American population and was one of the 23 California cities selected for bilingual schooling through Title VII; programs were initiated during the 1969-1970 school year. Chapter I, "The Sociolinguistic Description of a Bilingual Community" traces the history of the...
Topics: ERIC Archive, Bilingual Education, Bilingual Students, Bilingualism, Child Language, Community...
A review of the interactions between proposed Space Station systems/payloads and the environment that contribute to electromagnetic interference was performed. Seven prime sources of interference have been identified. These are: The Space Station power system; active experiments such as beam injection; ASTROMAG; ram and wake density gradients; pick up ions produced by vented or offgassed clouds; waves produced by current loops that include the plasma and structure; arcing from high voltage...
Topics: NASA Technical Reports Server (NTRS), ELECTROMAGNETIC INTERFERENCE, MAGNETIC FIELDS, PAYLOADS,...
We present the formal verification of synchronizing aspects of the Reliable Computing Platform (RCP), a fault-tolerant computing system for digital flight control applications. The RCP uses NMR-style redundancy to mask faults and internal majority voting to purge the effects of transient faults. The system design has been formally specified and verified using the EHDM verification system. Our formalization is based on an extended state machine model incorporating snapshots of local processors...
Topics: NASA Technical Reports Server (NTRS), FAULT TOLERANCE, FORMALISM, FLY BY WIRE CONTROL, MATHEMATICAL...
To ensure proper sensor operations, it is necessary to understand the situation of potential interference to sensors due to active equipment sharing common frequency bands as well as equipment occupying adjacent bands. The feasibility of sharing common frequency bands between passive sensors and other active services was analyzed. Potential interference to sensors due to equipment in bands adjacent to sensor frequency bands is examined and criteria to avoid interference is developed.
Topics: NASA Technical Reports Server (NTRS), MICROWAVE SENSORS, MICROWAVE TRANSMISSION, RADIO FREQUENCY...
A validation test has recently been constructed for wall interference methods as applied to the National Transonic Facility (NTF). The goal of this study was to begin to address the uncertainty of wall-induced-blockage interference corrections, which will make it possible to address the overall quality of data generated by the facility. The validation test itself is not specific to any particular modeling. For this present effort, the Transonic Wall Interference Correction System (TWICS) as...
Topics: NASA Technical Reports Server (NTRS), BLOCKING, TRANSONIC WIND TUNNELS, WIND TUNNEL TESTS,...
According to the Y-connected three-phase full-controlled bridge between two turn-on circuit, the paper studies the working principle and builds the mathematical model of permanent magnet brushless DC motor(BLDCM). Then the paper introduces fuzzy control technology, and designs the fuzzy control system of permanent magnet BLDCM, at the same time, the paper makes simulation in Matlab/Simulink. Being different from the conventional PID control system, the fuzzy control system of BLDCM can enhance...
Topics: permanent magnet BLDCM, fuzzy control, anti-interference, torque ripple, simulation
This project employed psychophysical techniques to examine the limitation on spatial vision imposed by the first stages in the visual pathway. All the experiments capitalized on the use of laser interferometry, which allows sinusoidal gratings to be formed on an observer's retina that are immune to optical blurring. Comparisons of contrast sensitivity to such gratings with contrast sensitivity to gratings viewed under normal conditions provides an estimate of the modulation transfer function of...
Topics: DTIC Archive, Williams, David R, ROCHESTER UNIV NY CENTER FOR VISUAL SCIENCE, *VISUAL ACUITY,...
In this work, the problem of optimum and near-optimum identification of the parameters of the Middleton Class A impulsive interference model is considered. In particular, under the assumption of the availability of a set of independent samples from the Class A envelope distribution, the problems of basic batch estimation of the Class A parameters, recursive identification of the parameters, and efficient estimation of the parameters for small sample sizes, are investigated. Within the context...
Topics: DTIC Archive, Zabin, Serena M, ILLINOIS UNIV AT URBANA COORDINATED SCIENCE LAB, *CHANNELS, *PULSES,...
Preliminary to a study on environmental mapping based on real data, a simulation was developed to study short pulse interference and its effect on detection in a pulse compression radar. A simulation was needed because the available data were recorded after the pulse compression network. This is too late to eliminate short pulse interference; it must be detected and eliminated prior to pulse compression. The simulation also treats the problem of removing clutter and short pulse interference...
Topics: DTIC Archive, Wilson,J D, NAVAL RESEARCH LAB WASHINGTON DC, *SIGNAL PROCESSING, *RADIOFREQUENCY...
This report describes and evaluates a new way to combine pseudo-noise (PN) spread spectrum and adaptive (antenna) arrays, consisting of multiple matched filters followed by sample matrix inversion (SMI) array processing. The evaluation of this technique was done by using a 4-element linear array and: (1) straightforward matrix calculations; (2) a computer computation of output signal-to-noise ratio; SNRO, versus angle when the theoretically correct noise covariance matrix was used; and (3) a...
Topics: DTIC Archive, Ristenbatt,M P, MICHIGAN UNIV ANN ARBOR COOLEY ELECTRONICS LAB, *Antenna arrays,...
Since 1 October 1991, Dr Min-Chang Lee and his students at MIT and Boston Univ., have conducted experimental and theoretical research aimed at investigating ionospheric plasma disturbances which can significantly affect radio wave propagation from satellite communications systems. His efforts have developed a theory to explain reflectivity of radio waves from lightning induced plasmas. In addition, his research has focused on enhanced radar backscatter, source mechanisms for generating...
Topics: DTIC Archive, Lee, Min-Chang, MASSACHUSETTS INST OF TECH CAMBRIDGE PLASMA FUSION CENTER,...
GPS-Squitter is a system concept that merges the capabilities of Automatic Dependent Surveillance (ADS) and the Mode S beacon radar. The result is an integrated concept for seamless surveillance and data link that permits equipped aircraft to participate in ADS and/or beacon ground environments. This concept offers many possibilities for transition from a beacon to an ADS-based environment. This report provides the details of the techniques used to estimate GPS-Squitter surveillance and data...
Topics: DTIC Archive, Orlando, V A, MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB, *DATA LINKS, *RADAR...
The fabrication of a high performance digital autocorrelator VLSI chip was successfully completed. The UNM-NASA SERC maintains an inventory of 30 packaged and tested correlator chips, for the Naval Research Laboratory. Additional chips are available upon the placement of an order.
Topics: DTIC Archive, Canaris, John, NEW MEXICO UNIV ALBUQUERQUE OFFICE OF RESEARCH SERVICES,...
GPS-Squitter is a system concept that merges the capabilities of Automatic Dependent Surveillance (ADS) and the Mode S beacon radar. The result is an integrated concept for seamless surveillance and data link that permits equipped aircraft to participate in ADS and/or beacon ground environments, offering many possibilities for transition from a beacon to an ADS-based environment. Since GPS-Squitter and its associated data link share the 1030/1090-MHz beacon frequencies with other users (e.g.,...
Topics: DTIC Archive, Orlando, Vincent A., MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB, *SURVEILLANCE,...
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generalmanual 000005518
Topics: radio, motorola, battery, code, fcc, charger, frequency, interference, refer, products,...
Single crystals of Beta-Al203 with a nominal composition of Na2O.11 Al203 were grown from stoichiometric melts contained in an iridium crucible. Seeding was achieved from an Al203 single crystal. The growth axis was along a and X-ray data confirmed the unit cell parameters of a = 5.595 A and c = 22.531 A. The top and bottom lattice constants of the boules were equal to + 0.002 A and indicated a fairly uniform composition. The measured density was 3.25 g/cm3. The boules remained physically...
Topics: DTIC Archive, Belt, R F, LITTON SYSTEMS INC CHARLOTTE NC AIRTRON DIV, *SINGLE CRYSTALS, *ALUMINUM...
This paper is concerned with developing reasonable criteria for the selection of frequency and power for very low and low-frequency (VLF/LF) transmitting stations. The approach uses a wave guide model for low-frequency propagation and accounts for the variability of the ionosphere. A sample problem involving a hypothetical transmitter is described.... Communications, Very low frequency, High voltage measurement, Low frequency antennas.
Topics: DTIC Archive, Ferguson, Jerry A, NAVAL COMMAND CONTROL AND OCEAN SURVEILLANCE CENTER RDT AND E DIV...
Electrical noise and interference in the LORAN-C frequency band was measured at two rural airports in Vermont and a major airport in Boston, Mass. The purpose of the test program was to determine the potential interfering sources that could affect the proper operation of the radio navigational system, LORAN-C, when it is used for non-precision approaches and terminal and en route navigation. Although no significant interference was observed, several continuous wave transmissions were identified...
Topics: DTIC Archive, Mauro,Peter G, TRANSPORTATION SYSTEMS CENTER CAMBRIDGE MA, *RADIOFREQUENCY...
The leakage magnetic fields from magnetic devices are known to create EMI problems for sensitive shipboard VLF receivers and sonar equipment. Devices which contain ferromagnetic cores can be particularly significant EMI offenders because of the high flux densities available in their magnetic circuits. This memorandum discusses the magnetic characteristics of various laminated cores found in shipboard equipment (with source frequencies extending into the VLF band). Test results are presented for...
Topics: DTIC Archive, Dalsass,Louis J, NAVAL UNDERWATER SYSTEMS CENTER NEWPORT RI, *ELECTROMAGNETIC...
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generalmanual 000046907
Topics: headset, telephone, fcc, plantronics, equipment, product, interference, warranty, handset, battery,...
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May 29, 2011
05/11
by
Thompson, Anne M.; Witte, Jacquelyn C
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Balloon-borne ozone instrumentation (ozonesondes), launched at fixed sites, is used to study local patterns in stratospheric and tropospheric ozone and to provide validation for satellite ozone products and model calculations of ozone. A paucity of coordinated ozonesonde data in the southern hemisphere tropics is being remedied in a 3-year project of coordinated ozonesondes launches at 10 sites. The data are available to the scientific community at the SHADOZ website at NASA/Goddard. Stations...
Topics: ADVANCED MICROWAVE SOUNDING UNIT, ELECTROMAGNETIC RADIATION, ELECTROMAGNETIC COMPATIBILITY,...
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May 31, 2011
05/11
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Monk, Jan C
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Lockheed Martin Astronautics Operations (LMA) was competitively awarded a contract May 21, 2001 for next generation launch system architecture definition and technology maturation. The Second Generation Launch Vehicle Program objectives include reducing the technical and programmatic risk of proceeding to full scale development of the system by establishing requirements for the next generation launch system and maturing critical technologies needed by the system. LMA will conduct analyses and...
Topics: INTERSYMBOLIC INTERFERENCE, THREE DIMENSIONAL MODELS, TRAVELING WAVE TUBES, SIGNAL ANALYSIS,...
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radioshack manual ome12 889
Topics: product, radioshack, plug, radio, volunne, antenna, interference, fcc, grounding, batteries, wall...
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Dec 31, 2016
12/16
by
Brian K Davis
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A quantitative estimate is given for the goodness of fit between the location of peaks in density of photon paths versus the peaks in fringe intensity produced by unperturbed self-interference. It establishes that the paths identified resolve the 'which way' problem in quantum theory, to within an error probability of four to five standard deviations.
Topics: photon trajectories, 'which way' problem, self-interference intensities, goodness of fit
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May 4, 2017
05/17
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Interference Archive
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“I knew there was this punk rock stuff, I didn’t know anything about it, I just went to a show, and it was like, this is really weird and I kinda like it.” —Dread Scott Dread Scott, artist and friend of Interference Archive, speaks with Vero Ordaz about his art, life, and connections to the Chicago punk scene--including memories prompted by his recent donation of posters to the archive. Image: Burning the US Constitution, documentation of a 2011 performance by Dread Scott...
Topics: podcast, Audio Interference, Interference Archive, punk, political art, Dread Scott
Field test results are emphasized in this report, which also contains background information on Air port Surface Traffic Control (ASTC) and the contract objectives. The NATIONAL Aviation Facilities Experiimental Center (NAFEC) field test series conclusively proved the technical feasibility of an Air Traffic Control Radar Beacon System (ATCRBS) based Airport Surface Traffic Control sensor system. Operational Data Acquisition Subsystem (DAS) performance projections developed to date as a result...
Topics: DTIC Archive, Brockway,A L, BENDIX CORP BALTIMORE MD COMMUNICATIONS DIV, *AIR TRAFFIC CONTROL...
In this thesis, the amplitude gain of received quadrature phase shift keying (QPSK) signals and interferences are estimated via the least squares error method in order to facilitate the implementation of reference-based successive interference cancellation (RSIC). In the scenario considered for this thesis, a system of multi-platform receivers is assumed to be positioned within the overlapping coverage areas of transmitting base stations. The first receiver initiates the RSIC technique by...
Topics: Parameter Estimation, Amplitude Gain Estimation, Successive Interference Cancellation, Least...
This research focuses on the detection of a low power communication signal in the presence of a strong co-channel television broadcast interference signal. The presence of strong co-channel interference makes the recovery of the desired weak power signal impossible using conventional filtering techniques that are based on time and frequency characteristics of the signals. The second-generation digital video broadcasting terrestrial (DVB-T2) standard is employed as co-channel interference in an...
Topics: orthogonal frequency-division multiplexing (OFDM), digital video broadcasting–terrestrial...
The Radar Beacon Transponder (RBX) is a ground-based transponder used to control the threat detection sensitivity level of BCAS aircraft operating in high density terminal airspace. The RBX is also used to deliver displayed resolution advisories from BCAS to the ATC facility. The normal DABS interrogation waveforms and message formats are used for communication between the RBX and BCAS aircraft. The appropriate BCAS sensitivity level is selected by comparing the BCAS aircraft position with an...
Topics: DTIC Archive, Sandholm,Ronald G, MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB, *MULTIPATH...
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generalmanual 000011041
Topics: monitor, envision, power, adjusts, color, osd, cord, khz, warranty, epi, power cord, video cable,...
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generalmanual 000044588
Topics: switch, linksys, network, hub, ethernet, warranty, port, devices, connect, cisco, twisted pair,...
Bell System Technical Journal, 52: 9. November 1973 pp 1521-1539. A Geometric Theory of Intersymbol Interference, Part II: Performance of the Maximum Likelihood Detector. (Messerschmitt, D.G. )
Topics: dfe, intersymbol, bounds, error, sequence, performance, geometric, mld, ratio, upper, isolated...
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Sep 24, 2020
09/20
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Kubra Yusifova, Ayub Aliyev Yusupovich
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The article contains data from studies of the interfering activity between fowlpox and rabies viruses. It was revealed that fowlpox virus is a convenient tool for studying the phenomenon of interference in primary trypsinized cell systems previously infected with rabies virus. Rabies virus inhibits cytogenesis and plaque formation in the cell system by fowlpox virus. It was revealed that the use of the cytopathogenic fowlpox virus in our experiments on the phenomenon of interference as an...
Topics: Quail embryo cell culture, interference, fowlpox virus
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generalmanual 000053569
Topics: kensington, universal, adapter, apple, voltage, plug, notebook, carairmanualapple, fcc,...
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Jan 25, 2015
01/15
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Panasonic
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Topics: button, sequence, controller, matrix, control, camera, switcher, appliance, pressing, select,...
This report discusses the difficulties encountered in acceleration measurements performed on gun and projectile systems and the techniques used to circumvent these difficulties. Particular points of discussion are the use of mechanical, digital, and electronic filtering techniques and their limitations.
Topics: DTIC Archive, Pilcher, II, James O, ARMY BALLISTIC RESEARCH LAB ABERDEEN PROVING GROUND MD,...
Thirty-five of 108 drugs tested may interfere with the trihydroxyindole fluorometric method for urinary free catecholamines. Screening for interference was accomplished by testing the total daily dose of a drug or portion thereof for possible fluorescence. Further information was obtained by adding a similar dose for each of 16 interfering drugs to 150 ml of fresh, pooled urine containing 67 ng/ml each of norepinephrine and epinephrine. Additional studies of seven interfering drugs were...
Topics: DTIC Archive, Mell,Leroy D , Jr, NAVAL MEDICAL RESEARCH INST BETHESDA MD, *CATECHOLAMINES,...
This Test Operations Procedure (TOP) provides methods for determining the electromagnetic compatibility of communications-electronics (C-E) equipment. It describes procedures to determine that C-E equipment and systems incorporate the best available technology for securing freedom from interference and that concepts for their use assure mutural compatibility with the resultant electromagnetic environment. (Author)
Topics: DTIC Archive, ARMY TEST AND EVALUATION COMMAND ABERDEEN PROVING GROUND MD, *COMMUNICATION...
The fundamental processes involved in the operation of the rectenna system designed for the solar power satellite system are described. The basic design choices are presented based on the desired microwave rf field concentration prior to rectification and based on the ground clearance requirements for the rectenna structure. A nonconcentrating inclined planar panel with a 2 meter minimum clearance configuration is selected as a representative of the typical rectenna.
Topics: NASA Technical Reports Server (NTRS), ENERGY CONVERSION, RECTENNAS, SOLAR POWER SATELLITES, SYSTEMS...
The detailed properties of sonic booms have to be better understood before commercial, next generation, supersonic and hypersonic aircraft can be properly developed. Experimental tests and measurements are needed to help sort the physical details of the flows at realistic test conditions. Some of these tests can be made in wind tunnels, but the need for full flight conditions simulation, the problem of tunnel wall interference, and the short distance the shocks can be examined from the...
Topics: NASA Technical Reports Server (NTRS), FLIGHT TESTS, FLOW DISTRIBUTION, FLOW VISUALIZATION,...
Path Loss Measurements were obtained on three (3) GPS equipped 757 aircraft. Systems measured were Marker Beacon, LOC, VOR, VHF (3), Glide Slope, ATC (2), DME (2), TCAS, and GPS. This data will provide the basis for assessing the EMI (Electromagnetic Interference) safety margins of comm/nav (communication and navigation) systems to portable electronic device emissions. These Portable Electronic Devices (PEDs) include all devices operated in or around the aircraft by crews, passengers, servicing...
Topics: NASA Technical Reports Server (NTRS), BOEING 757 AIRCRAFT, AIRCRAFT COMMUNICATION, AIR NAVIGATION,...
Grating is used in place of required folding mirror. Arrangement eliminates separate monochromator unit and uses retroreflector for alignment.
Topics: NASA Technical Reports Server (NTRS), INFRARED SPECTROMETERS, INTERFERENCE GRATING, OPTICAL...
Partial contents: Sol-Gel Production of Silica Microparticles; Synthesis of Zircon-Based Ceramic Pigments via Sol-Gel Methods; Sol-Gel Ceramic Pigments; Characterization of Oxide Layers Deposited by Sol-Gel; Mechanical Precision in Sol-Gel Manufacturing of 3-D Components; On the Thermal and Photochemical Stabilities of Photochromic Spirooxazine Dyes Encapsulated in Ormocer Matrices Derived by Sol-Gel Processing; Sol-Gel Coatings on Large Glass Substrates for Multilayer Interference Systems; A...
Topics: DTIC Archive, Schmidt, Helmut, INSTITUT FUER NEUE MATERIALIEN IM STADTWALD GEBAUDE SAARBRUECKEN...
Multipath propagation and the resulting interference are theoretically analyzed for a ballistic missile re-entry vehicle (RV) to aircraft telemetry link in order to predict performance parameters for the ARIA Phased Array Telemetry System (APATS). A basic two-path model incorporating direct and specularly reflected transmission is presented. Model calculations, which take into account RV and APATS antenna gain, polarization, sea state and Doppler shift, yield the depth and frequency of fade...
Topics: DTIC Archive, Robertshaw, G. A., MITRE CORP BEDFORD MA, *ANTENNA RADIATION PATTERNS, *MULTIPATH...
Presented is a method to estimate the element gains and phases of a sensor array when interfering signals, including specular multipath, are present. A movable calibration source is used. The element gains are derived from the relative output powers at the array elements. The element phases are obtained by transforming the array snapshots to make the source direction appear fixed and then maximizing a function constructed with the transformed snapshots. Computer simulations produce highly...
Topics: DTIC Archive, Hung, Eric K, DEFENCE RESEARCH ESTABLISHMENT OTTAWA (ONTARIO), *SIGNAL PROCESSING,...
The measurements performed, divided into two general categories, are summarized. The equipment reference performance measurements provide information for correlating the interference validation measurement results, one to another and to compare to existing measured data. The sensitivity and dynamic range measurements include the characteristics at two receiver output test points; (1) IF output before detection and (2) the PPI video output. Also, the dynamic range was measured with the output...
Topics: DTIC Archive, ATLANTIC RESEARCH CORP ALEXANDRIA VA, *RADAR EQUIPMENT, *ELECTROMAGNETIC...
The report describes the major system methodologies pertinent to the evaluation of contemporary fire control systems. It will serve as a useful reference for the systems analyst and as an aid for those who want to supplement their knowledge of the methodologies associated with radar systems analysis. Major emphasis is given to the description of radar performance in a benign and a nonbenign environment.
Topics: DTIC Archive, STANFORD RESEARCH INST MENLO PARK CA OPERATIONS RESEARCH DEPT, *RADAR, SYSTEMS...
The effects of sting support interference were investigated on the measurements of pitch damping, yaw damping, pitching moment slope, pitching moment and base pressure. The model was a 15 percent spherically blunt 7 deg cone. The forced oscillation technique was used to obtained data at Mach numbers 0.2 to 1.3 and Reynolds numbers, based on model based diameter, of 0.2 million to 3.6 million. The amplitude of oscillation was + or - 1 deg, and the reduced frequency parameters ranged from 0.006...
Topics: DTIC Archive, Cyran,F B, ARNOLD ENGINEERING DEVELOPMENT CENTER ARNOLD AFS TN, *STING MOUNTS, *WIND...
Possibilities for the use of a dispersive infrared spectrophotometer to determine the oxygen and carbon content of device quality silicon wafers have been examined. A novel approach to the analysis of the spectra bassed on a curve fitting method has been employed. This has been shown to provide very good rejection of interferences due to absorptions caused by precipitates present in heat treated material. Single instrument precisions for measurements on 350 micrometers device quality wafers of...
Topics: DTIC Archive, Series,R W, ROYAL SIGNALS AND RADAR ESTABLISHMENT MALVERN (ENGLAND), *INFRARED...
