WorldWideScience

Sample records for advanced microwave scanning

  1. GHRSST Level 2P Global Subskin Sea Surface Temperature from the Advanced Microwave Scanning Radiometer 2 on the GCOM-W satellite (GDS version 2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Advanced Microwave Scanning Radiometer 2 (AMSR2) was launched on 18 May 2012, onboard the Global Change Observation Mission - Water (GCOM-W) satellite developed...

  2. Advances in microwaves 8

    CERN Document Server

    Young, Leo

    2013-01-01

    Advances in Microwaves, Volume 8 covers the developments in the study of microwaves. The book discusses the circuit forms for microwave integrated circuits; the analysis of microstrip transmission lines; and the use of lumped elements in microwave integrated circuits. The text also describes the microwave properties of ferrimagnetic materials, as well as their interaction with electromagnetic waves propagating in bounded waveguiding structures. The integration techniques useful at high frequencies; material technology for microwave integrated circuits; specific requirements on technology for d

  3. Advances in microwaves 7

    CERN Document Server

    Young, Leo

    2013-01-01

    Advances in Microwaves, Volume 7 covers the developments in the study of microwaves. The book discusses the effect of surface roughness on the propagation of the TEM mode, as well as the voltage breakdown of microwave antennas. The text also describes the theory and design considerations of single slotted-waveguide linear arrays and the techniques and theories that led to the achievement of wide bandwidths and ultralow noise temperatures for communication applications. The book will prove invaluable to microwave engineers.

  4. Advances in microwaves 3

    CERN Document Server

    Young, Leo

    2013-01-01

    Advances in Microwaves, Volume 3 covers the advances and applications of microwave signal transmission and Gunn devices. This volume contains six chapters and begins with descriptions of ground-station antennas for space communications. The succeeding chapters deal with beam waveguides, which offer interesting possibilities for transmitting microwave energy, as well as with parallel or tubular beams from antenna apertures. A chapter discusses the electron transfer mechanism and the velocity-field characteristics, with a particular emphasis on the microwave properties of Gunn oscillators. The l

  5. Advanced microwave processing concepts

    Energy Technology Data Exchange (ETDEWEB)

    Lauf, R.J.; McMillan, A.D.; Paulauskas, F.L. [Oak Ridge National Laboratory, TN (United States)

    1995-05-01

    The purpose of this work is to explore the feasibility of several advanced microwave processing concepts to develop new energy-efficient materials and processes. The project includes two tasks: (1) commercialization of the variable-frequency microwave furnace; and (2) microwave curing of polymer composites. The variable frequency microwave furnace, whose initial conception and design was funded by the AIC Materials Program, will allow us, for the first time, to conduct microwave processing studies over a wide frequency range. This novel design uses a high-power traveling wave tube (TWT) originally developed for electronic warfare. By using this microwave source, one can not only select individual microwave frequencies for particular experiments, but also achieve uniform power densities over a large area by the superposition of many different frequencies. Microwave curing of thermoset resins will be studied because it hold the potential of in-situ curing of continuous-fiber composites for strong, lightweight components. Microwave heating can shorten curing times, provided issues of scaleup, uniformity, and thermal management can be adequately addressed.

  6. Advanced microwave processing concepts

    Energy Technology Data Exchange (ETDEWEB)

    Lauf, R.J.; McMillan, A.D.; Paulauskas, F.L. [Oak Ridge National Lab., TN (United States)

    1997-04-01

    The purpose of this work is to explore the feasibility of several advanced microwave processing concepts to develop new energy-efficient materials and processes. The project includes two tasks: (1) commercialization of the variable-frequency microwave furnace; and (2) microwave curing of polymeric materials. The variable frequency microwave furnace, whose initial conception and design was funded by the AIM Materials Program, allows the authors, for the first time, to conduct microwave processing studies over a wide frequency range. This novel design uses a high-power traveling wave tube (TWT) originally developed for electronic warfare. By using this microwave source, one can not only select individual microwave frequencies for particular experiments, but also achieve uniform power densities over a large area by the superposition of many different frequencies. Microwave curing of various thermoset resins will be studied because it holds the potential of in-situ curing of continuous-fiber composites for strong, lightweight components or in-situ curing of adhesives, including metal-to-metal. Microwave heating can shorten curing times, provided issues of scaleup, uniformity, and thermal management can be adequately addressed.

  7. Advances in microwaves

    CERN Document Server

    Young, Leo

    1967-01-01

    Advances in Microwaves, Volume 2 focuses on the developments in microwave solid-state devices and circuits. This volume contains six chapters that also describe the design and applications of diplexers and multiplexers. The first chapter deals with the parameters of the tunnel diode, oscillators, amplifiers and frequency converter, followed by a simple physical description and the basic operating principles of the solid state devices currently capable of generating coherent microwave power, including transistors, harmonic generators, and tunnel, avalanche transit time, and diodes. The next ch

  8. Advances in microwaves 4

    CERN Document Server

    Young, Leo

    2013-01-01

    Advances in Microwaves, Volume 4 covers some innovations in the devices and applications of microwaves. This volume contains three chapters and begins with a discussion of the application of microwave phasers and time delay elements as beam steering elements in array radars. The next chapter provides first an overview of the technical aspects and different types of millimeter waveguides, followed by a survey of their application to railroads. The last chapter examines the general mode of conversion properties of nonuniform waveguides, such as waveguide tapers, using converted Maxwell's equatio

  9. GHRSST Level 2P Global Subskin Sea Surface Temperature from the Advanced Scanning Microwave Radiometer - Earth Observing System (AMSR-E) on the NASA Aqua Satellite (GDS versions 1 and 2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Advanced Microwave Scanning Radiometer (AMSR-E) was launched on 4 May 2002, aboard NASA's Aqua spacecraft. The National Space Development Agency of Japan...

  10. GHRSST Level 2P Gridded Global Subskin Sea Surface Temperature from the Advanced Scanning Microwave Radiometer - Earth Observing System (AMSR-E) on the NASA Aqua Satellite (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Advanced Microwave Scanning Radiometer (AMSR-E) was launched on 4 May 2002, aboard NASA's Aqua spacecraft. The National Space Development Agency of Japan...

  11. GHRSST Level 2P Regional Subskin Sea Surface Temperature from the Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) on the NASA Aqua satellite for the Atlantic Ocean (GDS version 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Advanced Microwave Scanning Radiometer (AMSR-E) was launched on 4 May 2002, aboard NASA's Aqua spacecraft. The National Space Development Agency of Japan...

  12. Advances in imaging and quantification of electrical properties at the nanoscale using Scanning Microwave Impedance Microscopy (sMIM)

    Science.gov (United States)

    Friedman, Stuart; Stanke, Fred; Yang, Yongliang; Amster, Oskar

    Scanning Microwave Impedance Microscopy (sMIM) is a mode for Atomic Force Microscopy (AFM) enabling imaging of unique contrast mechanisms and measurement of local permittivity and conductivity at the 10's of nm length scale. sMIM has been applied to a variety of systems including nanotubes, nanowires, 2D materials, photovoltaics and semiconductor devices. Early results were largely semi-quantitative. This talk will focus on techniques for extracting quantitative physical parameters such as permittivity, conductivity, doping concentrations and thin film properties from sMIM data. Particular attention will be paid to non-linear materials where sMIM has been used to acquire nano-scale capacitance-voltage curves. These curves can be used to identify the dopant type (n vs p) and doping level in doped semiconductors, both bulk samples and devices. Supported in part by DOE-SBIR DE-SC0009856.

  13. A Scanning Microwave Radar and Radiometer

    DEFF Research Database (Denmark)

    Skou, Niels

    The Scanning Microwave Radar and Radiometer (SMRR) is a line scanner featuring a combined radar and radiometer system operating around 35 and 94 GHz. The layout of the SMRR is shown. The 2 offset antenna parabolas scan in synchronism, the receiver antenna has the highest gain in order to ensure...... that footprints are identical for the radar and the radiometer. The instrument will be flown in a pod under a Gulfstream G3 normally cruising with 240 m/sec at 12500 m, and will thus be able to sense clouds and precipitation from above...

  14. Advanced Network Scanning

    Directory of Open Access Journals (Sweden)

    Ashiqur Rahman

    2016-07-01

    Full Text Available Network scanning is à procedure for identifying active hosts on a network, either for the purpose of attacking them or for network security assessment. Scanning procedures, such as ping sweeps and port scans, return information about which IP addresses map to live hosts that are active on the Internet and what services they offer. Another scanning method, inverse mapping, returns information about what IP addresses do not map to live hosts; this enables an attacker to make assumptions about viable addresses. Scanning is one of three components of intelligence gathering for an attacker. In the foot printing phase, the attacker creates a profile of the target organization, with information such as its domain name system (DNS and e-mail servers, and its IP address range. Most of this information is available online. In the scanning phase, the attacker finds information about the specific IP addresses that can be accessed over the Internet, their operating systems, the system architecture, and the services running on each computer. In the enumeration phase, the attacker gathers information such as network user and group names, routing tables, and Simple Network Management Protocol (SNMP data

  15. Advanced Microwave Electrothermal Thruster (AMET) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Orbital Technologies Corporation (ORBITEC) and the University of Alabama at Huntsville (UAH) propose to develop the Advanced Microwave Electrothermal Thruster...

  16. Recent Advancements in Microwave Imaging Plasma Diagnostics

    International Nuclear Information System (INIS)

    Significant advances in microwave and millimeter wave technology over the past decade have enabled the development of a new generation of imaging diagnostics for current and envisioned magnetic fusion devices. Prominent among these are revolutionary microwave electron cyclotron emission imaging (ECEI), microwave phase imaging interferometers, imaging microwave scattering and microwave imaging reflectometer (MIR) systems for imaging electron temperature and electron density fluctuations (both turbulent and coherent) and profiles (including transport barriers) on toroidal devices such as tokamaks, spherical tori, and stellarators. The diagnostic technology is reviewed, and typical diagnostic systems are analyzed. Representative experimental results obtained with these novel diagnostic systems are also presented

  17. Recent Advancements in Microwave Imaging Plasma Diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    H. Park; C.C. Chang; B.H. Deng; C.W. Domier; A.J.H. Donni; K. Kawahata; C. Liang; X.P. Liang; H.J. Lu; N.C. Luhmann, Jr.; A. Mase; H. Matsuura; E. Mazzucato; A. Miura; K. Mizuno; T. Munsat; K. and Y. Nagayama; M.J. van de Pol; J. Wang; Z.G. Xia; W-K. Zhang

    2002-03-26

    Significant advances in microwave and millimeter wave technology over the past decade have enabled the development of a new generation of imaging diagnostics for current and envisioned magnetic fusion devices. Prominent among these are revolutionary microwave electron cyclotron emission imaging (ECEI), microwave phase imaging interferometers, imaging microwave scattering and microwave imaging reflectometer (MIR) systems for imaging electron temperature and electron density fluctuations (both turbulent and coherent) and profiles (including transport barriers) on toroidal devices such as tokamaks, spherical tori, and stellarators. The diagnostic technology is reviewed, and typical diagnostic systems are analyzed. Representative experimental results obtained with these novel diagnostic systems are also presented.

  18. Analytical scanning evanescent microwave microscope and control stage

    Science.gov (United States)

    Xiang, Xiao-Dong; Gao, Chen; Duewer, Fred; Yang, Hai Tao; Lu, Yalin

    2009-06-23

    A scanning evanescent microwave microscope (SEMM) that uses near-field evanescent electromagnetic waves to probe sample properties is disclosed. The SEMM is capable of high resolution imaging and quantitative measurements of the electrical properties of the sample. The SEMM has the ability to map dielectric constant, loss tangent, conductivity, electrical impedance, and other electrical parameters of materials. Such properties are then used to provide distance control over a wide range, from to microns to nanometers, over dielectric and conductive samples for a scanned evanescent microwave probe, which enable quantitative non-contact and submicron spatial resolution topographic and electrical impedance profiling of dielectric, nonlinear dielectric and conductive materials. The invention also allows quantitative estimation of microwave impedance using signals obtained by the scanned evanescent microwave probe and quasistatic approximation modeling. The SEMM can be used to measure electrical properties of both dielectric and electrically conducting materials.

  19. Comparison of data from the Scanning Multifrequency Microwave Radiometer (SMMR) with data from the Advanced Very High Resolution Radiometer (AVHRR) for terrestrial environmental monitoring - An overview

    Science.gov (United States)

    Townshend, J. R. G.; Choudhury, B. J.; Tucker, C. J.; Giddings, L.; Justice, C. O.

    1989-01-01

    Comparison between the microwave polarized difference temperature (MPDT) derived from 37 GHz band data and the normalized difference vegetation index (NDVI) derived from near-infrared and red bands, from several empirical investigations are summarized. These indicate the complementary character of the two measures in environmental monitoring. Overall the NDVI is more sensitive to green leaf activity, whereas the MPDT appears also to be related to other elements of the above-ground biomass. Monitoring of hydrological phenomena is carried out much more effectively by the MPDT. Further work is needed to explain spectral and temporal variation in MPDT both through modelling and field experiments.

  20. Scanning near field microwave microscopy based on an active resonator

    Science.gov (United States)

    Qureshi, Naser; Kolokoltsev, Oleg; Ordonez-Romero, Cesar Leonardo

    2014-03-01

    A large number of recent implementations of near field scanning microwave microscopy (NFSMM) have been based on the perturbation of a resonant cavity connected to a sharp scanning probe. In this work we present results from an alternative approach: the perturbation of a microwave source connected to a scanning tip. Based on a yittrium iron garnet (YIG) cavity ring resonator this scanning probe system has a quality factor greater than 106, which allows us to detect very small frequency shifts, which translates to a very high sensitivity in sample impedance measurements. Using a selection of representative semiconductor, metal and biological samples we show how this approach leads to unusually high sensitivity and spatial resolution. Work supported by a grant from PAPIIT, UNAM 104513.

  1. Advanced Microwave Circuits and Systems

    DEFF Research Database (Denmark)

    This book is based on recent research work conducted by the authors dealing with the design and development of active and passive microwave components, integrated circuits and systems. It is divided into seven parts. In the first part comprising the first two chapters, alternative concepts and...... equations for multiport network analysis and characterization are provided. A thru-only de-embedding technique for accurate on-wafer characterization is introduced. The second part of the book corresponds to the analysis and design of ultra-wideband low-noise amplifiers (LNA). The LNA is the most critical...... component in a receiving system. Its performance determines the overall system sensitivity because it is the first block to amplify the received signal from the antenna. Hence, for the achievement of high receiver performance, the LNA is required to have a low noise figure with good input matching as well...

  2. Electrical characterization of doped semiconductor nanostructures with scanning microwave microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Fenner, Matthias A.; Tanbakuchi, Hassan [Agilent Technologies, Kronberg (Germany); Streit, Stephan; Baumgart, Christine; Helm, Manfred; Schmidt, Heidemarie [Institute of Ion Beam Physics and Materials Research, Forschungszentrum Dresden-Rossendorf e.V., Dresden (Germany)

    2010-07-01

    Highly sensitive scanning microwave microscopy (SMM) with a capacitance resolution in the aF range has been used to investigate the electrical properties of doped semiconductor nanostructures in the microwave frequency range from 1.5 GHz to 6 GHz at different dc offset biases. The microwave signal S11 reflected by the sample is related to the impedance of the sample. Superimposing an ac voltage in the kHz range one also gains information about the derivative of the S11 signal (dC/dV), which is dependent on the doping density in the semiconductor, circuit resistance, and reactance. We investigated a static random access memory (SRAM) cell and one cross-sectionally prepared Si epilayer structured sample. The derivative of S11 strongly depends on the dc offset bias. The Si epilayer sample reveals the strongest dependence on f{sub ac} and also on the biasing history during the SMM measurements.

  3. Advanced microwave radiometer antenna system study

    Science.gov (United States)

    Kummer, W. H.; Villeneuve, A. T.; Seaton, A. F.

    1976-01-01

    The practicability of a multi-frequency antenna for spaceborne microwave radiometers was considered in detail. The program consisted of a comparative study of various antenna systems, both mechanically and electronically scanned, in relation to specified design goals and desired system performance. The study involved several distinct tasks: definition of candidate antennas that are lightweight and that, at the specified frequencies of 5, 10, 18, 22, and 36 GHz, can provide conical scanning, dual linear polarization, and simultaneous multiple frequency operation; examination of various feed systems and phase-shifting techniques; detailed analysis of several key performance parameters such as beam efficiency, sidelobe level, and antenna beam footprint size; and conception of an antenna/feed system that could meet the design goals. Candidate antennas examined include phased arrays, lenses, and optical reflector systems. Mechanical, electrical, and performance characteristics of the various systems were tabulated for ease of comparison.

  4. Optimization of the imaging response of scanning microwave microscopy measurements

    Energy Technology Data Exchange (ETDEWEB)

    Sardi, G. M.; Lucibello, A.; Proietti, E.; Marcelli, R., E-mail: romolo.marcelli@imm.cnr.it [National Research Council, Institute for Microelectronics and Microsystems, Via del Fosso del Cavaliere 100, 00133 Rome (Italy); Kasper, M.; Gramse, G. [Biophysics Institute, Johannes Kepler University, Gruberstrasse 40, 4020 Linz (Austria); Kienberger, F. [Keysight Technologies Austria GmbH, Gruberstrasse 40, 4020 Linz (Austria)

    2015-07-20

    In this work, we present the analytical modeling and preliminary experimental results for the choice of the optimal frequencies when performing amplitude and phase measurements with a scanning microwave microscope. In particular, the analysis is related to the reflection mode operation of the instrument, i.e., the acquisition of the complex reflection coefficient data, usually referred as S{sub 11}. The studied configuration is composed of an atomic force microscope with a microwave matched nanometric cantilever probe tip, connected by a λ/2 coaxial cable resonator to a vector network analyzer. The set-up is provided by Keysight Technologies. As a peculiar result, the optimal frequencies, where the maximum sensitivity is achieved, are different for the amplitude and for the phase signals. The analysis is focused on measurements of dielectric samples, like semiconductor devices, textile pieces, and biological specimens.

  5. Optimization of the imaging response of scanning microwave microscopy measurements

    International Nuclear Information System (INIS)

    In this work, we present the analytical modeling and preliminary experimental results for the choice of the optimal frequencies when performing amplitude and phase measurements with a scanning microwave microscope. In particular, the analysis is related to the reflection mode operation of the instrument, i.e., the acquisition of the complex reflection coefficient data, usually referred as S11. The studied configuration is composed of an atomic force microscope with a microwave matched nanometric cantilever probe tip, connected by a λ/2 coaxial cable resonator to a vector network analyzer. The set-up is provided by Keysight Technologies. As a peculiar result, the optimal frequencies, where the maximum sensitivity is achieved, are different for the amplitude and for the phase signals. The analysis is focused on measurements of dielectric samples, like semiconductor devices, textile pieces, and biological specimens

  6. A broadband toolbox for scanning microwave microscopy transmission measurements

    Science.gov (United States)

    Lucibello, Andrea; Sardi, Giovanni Maria; Capoccia, Giovanni; Proietti, Emanuela; Marcelli, Romolo; Kasper, Manuel; Gramse, Georg; Kienberger, Ferry

    2016-05-01

    In this paper, we present in detail the design, both electromagnetic and mechanical, the fabrication, and the test of the first prototype of a Scanning Microwave Microscope (SMM) suitable for a two-port transmission measurement, recording, and processing the high frequency transmission scattering parameter S21 passing through the investigated sample. The S21 toolbox is composed by a microwave emitter, placed below the sample, which excites an electromagnetic wave passing through the sample under test, and is collected by the cantilever used as the detector, electrically matched for high frequency measurements. This prototype enhances the actual capability of the instrument for a sub-surface imaging at the nanoscale. Moreover, it allows the study of the electromagnetic properties of the material under test obtained through the measurement of the reflection (S11) and transmission (S21) parameters at the same time. The SMM operates between 1 GHz and 20 GHz, current limit for the microwave matching of the cantilever, and the high frequency signal is recorded by means of a two-port Vector Network Analyzer, using both contact and no-contact modes of operation, the latter, especially minded for a fully nondestructive and topography-free characterization. This tool is an upgrade of the already established setup for the reflection mode S11 measurement. Actually, the proposed setup is able to give richer information in terms of scattering parameters, including amplitude and phase measurements, by means of the two-port arrangement.

  7. Scanning Mechanism of the FY-3 Microwave Humidity Sounder

    Science.gov (United States)

    Schmid, Manfred; Jing, Li; Hehr, Christian

    2010-01-01

    Astrium GmbH Germany, developed the scanning equipment for the instrument package of the MicroWave Humidity Sounder (MWHS) flying on the FY-3 meteorological satellite (FY means Feng Yun, Wind and Cloud) in a sun-synchronized orbit of 850-km altitude and at an inclination of 98.8 . The scanning mechanism rotates at variable velocity comprising several acceleration / deceleration phases during each revolution. The Scanning Mechanism contains two output shafts, each rotating a parabolic offset Antenna Reflector. The mechanism is operated in closed loop by means of redundant control electronics. MWHS is a sounding radiometer for measurement of global atmospheric water vapour profiles. An Engineering Qualification Model was developed and qualified and a first Flight Model was launched early 2008. The system is now working for more than two years successful in orbit. A second Flight Model of the Antenna Scanning Mechanism and of its associated control electronics was built and delivered to the customer for application on the follow-on spacecraft that will be launched by the end of 2010.

  8. Recent advances in processing and applications of microwave ferrites

    International Nuclear Information System (INIS)

    Next generation magnetic microwave devices will be planar, smaller, weigh less, and perform well beyond the present state-of-the-art. For this to become a reality advances in ferrite materials must first be realized. These advances include self-bias magnetization, tunability of the magnetic anisotropy, low microwave loss, and volumetric and weight reduction. To achieve these goals one must turn to novel materials processing methods. Here, we review recent advances in the processing of microwave ferrites. Attention is paid to the processing of ferrite films by pulsed laser deposition, liquid phase epitaxy, spin spray ferrite plating, screen printing, and compaction of quasi-single crystals. Conventional and novel applications of ferrite materials, including microwave non-reciprocal passive devices, microwave signal processing, negative index metamaterial-based electronics, and electromagnetic interference suppression are discussed.

  9. Advancements of microwave diagnostics in magnetically confined plasmas

    NARCIS (Netherlands)

    Mase, A.; Kogi, Y.; Ito, N.; Yokota, Y.; Akaki, K.; Kawahata, K.; Nagayama, Y.; Tokuzawa, T.; Yamaguchi, S.; Hojo, H.; Oyama, N.; N C Luhmann Jr.,; Park, H. K.; Donne, A. J. H.

    2009-01-01

    Microwave to millimeter-wave diagnostic techniques such as interferometry, reflectometry, scattering and radiometry have been powerful tools for diagnosing magnetically confined plasmas. Recent advances in electronic devices and components together with computer technology have enabled the developme

  10. Microwave beam steerers for electronically scanned reflectometers (abstract)

    International Nuclear Information System (INIS)

    One of the problems encountered in the application of reflectometry to fusion plasmas is that the transmit antenna must be aligned such that the reflected wave form is successfully collected by a suitably arranged receive antenna. This task is made even more difficult in the case of shaped plasmas, or when plasma motion is such that the incident wave is no longer normal to the plasma surface. One would ideally like to have antennas which may be steered in real time to compensate for changes in plasma shape and/or position. A program has been initiated at U.C. Davis to address this problem, and microwave beam steerers suitable for electronically scanned reflectometers have been developed. The approach taken has been to develop phased antenna array (PAA) concepts which operate over broad bandwidths. Laboratory test results of a proof-of-principle PAA system will be presented, along with a description of ongoing research activities by U.C. Davis in this field. copyright 1999 American Institute of Physics

  11. The Advanced Microwave Sounding Unit-A: Antenna Number 2 Bearing Assembly Life Test

    Science.gov (United States)

    Powers, Charles E.

    1997-01-01

    Four bearing assemblies, lubricated with Apiezon C oil with 5% lead naphthenate (PbNp), were life tested in support of the Advanced Microwave Sounding Unit-A (AMSU-A). These assemblies were tested continuously for five to six years using the scanning pattern of the flight instrument. A post-life-test analysis was performed on two of the assemblies to evaluate the lubricant behavior and wear in the bearings.

  12. Advanced Microwave Radiometer (AMR) for SWOT mission

    Science.gov (United States)

    Chae, C. S.

    2015-12-01

    The objective of the SWOT (Surface Water & Ocean Topography) satellite mission is to measure wide-swath, high resolution ocean topography and terrestrial surface waters. Since main payload radar will use interferometric SAR technology, conventional microwave radiometer system which has single nadir look antenna beam (i.e., OSTM/Jason-2 AMR) is not ideally applicable for the mission for wet tropospheric delay correction. Therefore, SWOT AMR incorporates two antenna beams along cross track direction. In addition to the cross track design of the AMR radiometer, wet tropospheric error requirement is expressed in space frequency domain (in the sense of cy/km), in other words, power spectral density (PSD). Thus, instrument error allocation and design are being done in PSD which are not conventional approaches for microwave radiometer requirement allocation and design. A few of novel analyses include: 1. The effects of antenna beam size to PSD error and land/ocean contamination, 2. Receiver error allocation and the contributions of radiometric count averaging, NEDT, Gain variation, etc. 3. Effect of thermal design in the frequency domain. In the presentation, detailed AMR design and analyses results will be discussed.

  13. A Survey of Advanced Microwave Frequency Measurement Techniques

    Directory of Open Access Journals (Sweden)

    Anand Swaroop Khare

    2012-06-01

    Full Text Available Microwaves are radio waves with wavelengths ranging from as long as one meter to as short as one millimeter, or equivalently, with frequencies between 300 MHz and 300 GHz. The science of photonics includes the generation, emission, modulation, signal processing, switching, transmission, amplification, detection and sensing of light. Microwave photonics has been introduced for achieving ultra broadband signal processing. Instantaneous Frequency Measurement (IFM receivers play an important role in electronic warfare. Technologies used for signal processing, include conventional direct Radio Frequency (RF techniques, digital techniques, intermediate frequency (IF techniques and photonic techniques. Direct RF techniques suffer an increased loss, high dispersion, and unwanted radiation problems in high frequencies. The systems that use traditional RF techniques can be bulky and often lack the agility required to perform advanced signal processing in rapidly changing environments. In this paper we discussed a survey of Microwave Frequency Measurement Techniques. The microwaves techniques are categorized based upon different approaches. This paper provides the major advancement in the Microwave Frequency MeasurementTechniques research; using these approaches the features and categories in the surveyed existing work.

  14. Technology advances in active and passive microwave sensing through 1985

    Science.gov (United States)

    Barath, F. T.

    1977-01-01

    As a result of a growing awareness by the remote sensing community of the unique capabilities of passive and active microwave sensors, these instruments are expected to grow in the next decade in numbers, versatility and complexity. The Nimbus-G and Seasat-A Scanning Multichannel Microwave Spectrometer (SMMR), the Seasat-A radar altimeter, scatterometer and synthetic aperture radar represent the first systematic attempt at exploring a wide variety of applications utilizing microwave sensing techniques and are indicators of the directions in which the pertinent technology is likely to evolve. The trend is toward high resolution multi-frequency imagers spanning wide frequency ranges and wide swaths requiring sophisticated receivers, real-time data processors and most importantly, complex antennas.

  15. Measurement of electric-field intensities using scanning near-field microwave microscopy

    OpenAIRE

    SHVETS, IGOR; KANTOR, ROMAN

    2003-01-01

    PUBLISHED In this paper, we propose methods for the measurement of electric intensities of a microwave field above the surface of microwave circuits. Using miniaturized coaxial antennas, we measure all spatial components of the induced field above device-under-test. A special position/signal difference method is used to better localize the measured field and increase the spatial resolution of the field mapping. During the scanning process, the antenna is driven at the defined distance abov...

  16. Development of Near-Field Microwave Microscope with the Functionality of Scanning Tunneling Spectroscopy

    Science.gov (United States)

    Machida, Tadashi; Gaifullin, Marat B.; Ooi, Shuuich; Kato, Takuya; Sakata, Hideaki; Hirata, Kazuto

    2010-11-01

    We describe the details of an original near-field scanning microwave microscope, developed for simultaneous measurements of local density-of-states (LDOS) and local ohmic losses (LOL). Improving microwave detection systems, we have succeeded in distinguishing the LDOS and LOL even between two low resistance materials; gold and highly orientated pyrolitic graphite. The experimental data indicate that our microscope holds a capability to investigate both LDOS and LOL in nanoscale.

  17. Advanced microwave/millimeter-wave imaging technology

    International Nuclear Information System (INIS)

    Millimeter wave technology advances have made possible active and passive millimeter wave imaging for a variety of applications including advanced plasma diagnostics, radio astronomy, atmospheric radiometry, concealed weapon detection, all-weather aircraft landing, contraband goods detection, harbor navigation/surveillance in fog, highway traffic monitoring in fog, helicopter and automotive collision avoidance in fog, and environmental remote sensing data associated with weather, pollution, soil moisture, oil spill detection, and monitoring of forest fires, to name but a few. The primary focus of this paper is on technology advances which have made possible advanced imaging and visualization of magnetohydrodynamic (MHD) fluctuations and microturbulence in fusion plasmas. Topics of particular emphasis include frequency selective surfaces, planar Schottky diode mixer arrays, electronically controlled beam shaping/steering arrays, and high power millimeter wave local oscillator and probe sources. (author)

  18. Metamaterial-inspired miniaturized microwave edge coupled surface scanning probe

    Science.gov (United States)

    Wiwatcharagoses, Nophadon; Park, Kyoung Y.; Chahal, Premjeet; Udpa, Lalita

    2013-01-01

    This paper introduces a new concept on sub-wavelength resolution imaging and surface scanning using metamaterial based near field sensor array. Multiple split ring resonator structures (SRRs), having different band stop frequencies, are implemented in a microstrip transmission line configuration. A mirror image copy of these resonators is also incorporated on the transmission line to achieve built in frequency references. A smart card is scanned to detect buried antenna and Si chip within the plastic card.

  19. Photon CT scanning of advanced ceramic materials

    International Nuclear Information System (INIS)

    Advanced ceramic materials are being developed for high temperature applications in advanced heat engines and high temperature heat recovery systems. Small size flaws (10 - 200 μm) and small nonuniformities in density distributions (0.1 -2%) present as long-range density gradients, are critical in most ceramics and their detection is of crucial importance. Computed tomographic (CT) imaging provides a means of obtaining a precise two-dimensional density map of a cross section through an object from which accurate information about small flaws and small density gradients can be obtained. With the use of high energy photon sources high contrast CT images can be obtained for both low and high density ceramics. In the present paper we illustrate the applicability of the photon CT technique to the examination of advanced ceramics. CT images of sintered alumina tiles are presented from which data on high-density inclusions, cracks and density gradients have been extracted

  20. A near-field scanning microwave microscope based on a superconducting resonator for low power measurements

    Science.gov (United States)

    de Graaf, S. E.; Danilov, A. V.; Adamyan, A.; Kubatkin, S. E.

    2013-02-01

    We report on the design and performance of a cryogenic (300 mK) near-field scanning microwave microscope. It uses a microwave resonator as the near-field sensor, operating at a frequency of 6 GHz and microwave probing amplitudes down to 100 {μ V}, approaching low enough photon population (N ˜ 1000) of the resonator such that coherent quantum manipulation becomes feasible. The resonator is made out of a miniaturized distributed fractal superconducting circuit that is integrated with the probing tip, micromachined to be compact enough such that it can be mounted directly on a quartz tuning-fork, and used for parallel operation as an atomic force microscope (AFM). The resonator is magnetically coupled to a transmission line for readout, and to achieve enhanced sensitivity we employ a Pound-Drever-Hall measurement scheme to lock to the resonance frequency. We achieve a well localized near-field around the tip such that the microwave resolution is comparable to the AFM resolution, and a capacitive sensitivity down to 6.4 × 10-20 F/sqrt{Hz}, limited by mechanical noise. We believe that the results presented here are a significant step towards probing quantum systems at the nanoscale using near-field scanning microwave microscopy.

  1. Planar metamaterial-based beam-scanning broadband microwave antenna

    International Nuclear Information System (INIS)

    The broadband directive emission from the use of waveguided metamaterials is numerically and experimentally reported. The metamaterials, which are composed of non-resonant circular complementary closed ring structures printed on a dielectric substrate, are designed to obey the refractive index of a Luneburg lens. An arc array of planar radiating slot antennas placed at the periphery of the lens is used as wave launchers. A prototype of the lens associated with the feed structures has been fabricated using standard lithography techniques. To experimentally demonstrate the broadband focusing properties and directive emissions, far-field radiation patterns have been measured. Furthermore, this metamaterial-based lens can be used to achieve beam-scanning with a coverage of up to 120 °. Far-field measurements agree qualitatively with calculated near-field distributions

  2. Predicting moisture content and density distribution of Scots pine by microwave scanning of sawn timber

    International Nuclear Information System (INIS)

    This study was carried out to investigate the possibility of calibrating a prediction model for the moisture content and density distribution of Scots pine (Pinus sylvestris) using microwave sensors. The material was initially of green moisture content and was thereafter dried in several steps to zero moisture content. At each step, all the pieces were weighed, scanned with a microwave sensor (Satimo 9,4GHz), and computed tomography (CT)-scanned with a medical CT scanner (Siemens Somatom AR.T.). The output variables from the microwave sensor were used as predictors, and CT images that correlated with known moisture content were used as response variables. Multivariate models to predict average moisture content and density were calibrated using the partial least squares (PLS) regression. The models for average moisture content and density were applied at the pixel level, and the distribution was visualized. The results show that it is possible to predict both moisture content distribution and density distribution with high accuracy using microwave sensors. (author)

  3. The Passive Microwave Neural Network Precipitation Retrieval (PNPR) for AMSU/MHS and ATMS cross-track scanning radiometers

    Science.gov (United States)

    Sano', Paolo; Casella, Daniele; Panegrossi, Giulia; Cinzia Marra, Anna; Dietrich, Stefano

    2016-04-01

    Spaceborne microwave cross-track scanning radiometers, originally developed for temperature and humidity sounding, have shown great capabilities to provide a significant contribution in precipitation monitoring both in terms of measurement quality and spatial/temporal coverage. The Passive microwave Neural network Precipitation Retrieval (PNPR) algorithm for cross-track scanning radiometers, originally developed for the Advanced Microwave Sounding Unit/Microwave Humidity Sounder (AMSU-A/MHS) radiometers (on board the European MetOp and U.S. NOAA satellites), was recently newly designed to exploit the Advanced Technology Microwave Sounder (ATMS) on board the Suomi-NPP satellite and the future JPSS satellites. The PNPR algorithm is based on the Artificial Neural Network (ANN) approach. The main PNPR-ATMS algorithm changes with respect to PNPR-AMSU/MHS are the design and implementation of a new ANN able to manage the information derived from the additional ATMS channels (respect to the AMSU-A/MHS radiometer) and a new screening procedure for not-precipitating pixels. In order to achieve maximum consistency of the retrieved surface precipitation, both PNPR algorithms are based on the same physical foundation. The PNPR is optimized for the European and the African area. The neural network was trained using a cloud-radiation database built upon 94 cloud-resolving simulations over Europe and the Mediterranean and over the African area and radiative transfer model simulations of TB vectors consistent with the AMSU-A/MHS and ATMS channel frequencies, viewing angles, and view-angle dependent IFOV sizes along the scan projections. As opposed to other ANN precipitation retrieval algorithms, PNPR uses a unique ANN that retrieves the surface precipitation rate for all types of surface backgrounds represented in the training database, i.e., land (vegetated or arid), ocean, snow/ice or coast. This approach prevents different precipitation estimates from being inconsistent with one

  4. Portable automated imaging in complex ceramics with a microwave interference scanning system

    Science.gov (United States)

    Goitia, Ryan M.; Schmidt, Karl F.; Little, Jack R.; Ellingson, William A.; Green, William; Franks, Lisa P.

    2013-01-01

    An improved portable microwave interferometry system has been automated to permit rapid examination of components with minimal operator attendance. Functionalities include stereo and multiplexed, frequency-modulated at multiple frequencies, producing layered volumetric images of complex ceramic structures. The technique has been used to image composite ceramic armor and ceramic matrix composite components, as well as other complex dielectric materials. The system utilizes Evisive Scan microwave interference scanning technique. Validation tests include artificial and in-service damage of ceramic armor, surrogates and ceramic matrix composite samples. Validation techniques include micro-focus x-ray and computed tomography imaging. The microwave interference scanning technique has demonstrated detection of cracks, interior laminar features and variations in material properties such as density. The image yields depth information through phase angle manipulation, and shows extent of feature and relative dielectric property information. It requires access to only one surface, and no coupling medium. Data are not affected by separation of layers of dielectric material, such as outer over-wrap. Test panels were provided by the US Army Research Laboratory, and the US Army Tank Automotive Research, Development and Engineering Center (TARDEC), who with the US Air Force Research Laboratory have supported this work.

  5. Recent advances in environmental monitoring using commercial microwave links

    Science.gov (United States)

    Alpert, Pinhas; Guez, Oded; Messer, Hagit; David, Noam; Harel, Oz; Eshel, Adam; Cohen, Ori

    2016-04-01

    Recent advances in environmental monitoring using commercial microwave links Pinhas Alpert, H. Messer, N. David, O. Guez, O. Cohen, O. Harel, A. Eshel Tel Aviv University, Israel The propagation of electromagnetic radiation in the lower atmosphere, at centimeter wavelengths, is impaired by atmospheric conditions. Absorption and scattering of the radiation, at frequencies of tens of GHz, are directly related to the atmospheric phenomena, primarily precipitation, oxygen, mist, fog and water vapor. As was recently shown, wireless communication networks supply high resolution precipitation measurements at ground level while often being situated in flood prone areas, covering large parts of these hazardous regions. On the other hand, at present, there are no satisfactory real time flash flood warning facilities found to cope well with this phenomenon. I will exemplify the flash flood warning potential of the commercial wireless communication system for semi-arid region cases when floods occurred in the Judean desert in Israel with comparison to hydrological measurements in the Dead Sea area. In addition, I will review our recent improvements in monitoring rainfall as well as other-than-rain phenomena like, fog, dew, atmospheric moisture. References: N. David, P. Alpert, and H. Messer, "Technical Note: Novel method for water vapor monitoring using wireless communication networks measurements", Atmos. Chem. Phys., 9, 2413-2418, 2009. A. Rayitsfeld, R. Samuels, A. Zinevich, U. Hadar and P. Alpert,"Comparison of two methodologies for long term rainfall monitoring using a commercial microwave communication system", Atmospheric Research 104-105, 119-127, 2012. N. David, O. Sendik, H. Messer and P. Alpert, "Cellular network infrastructure-the future of fog monitoring?" BAMS (Oct. issue), 1687-1698, 2015. O. Harel, David, N., Alpert, P. and Messer, H., "The potential of microwave communication networks to detect dew using the GLRT- experimental study", IEEE Journal of Selected

  6. Blending sequential scanning multichannel microwave radiometer and buoy data into a sea ice model

    Science.gov (United States)

    Thomas, D. R.; Rothrock, D. A.

    1989-08-01

    A method is presented for determining the concentrations of open water and of several ice types using multichannel satellite passive microwave data. The method uses the Kalman filter and provides the "best fit" to a time series of data. A crucial element of the procedure is a physical model of how the concentrations of ice types change with time in response to freezing, melting, aging of one ice type to another, and creation of open water by divergence of the ice cover. A measurement model relates the state of the ice cover to the multivariate microwave data. The procedure offers three distinct advantages over algorithms that interpret separately data from each instant in time: it provides a framework for incorporating additional data into the diagnosis of ice concentrations, it takes into account the known uncertainty in the microwave observations and the pure type signatures, and it allows the resolution of ice types with ambiguous signatures. Two examples are presented which make use of scanning multichannel microwave radiometer data and surface temperature and ice velocity data from drifting buoys to estimate the concentrations of open water, first-year, second-year, and older multiyear ice for a Lagrangian region of ice. Two other examples include melt ponds in place of second-year ice. Some of the parameters in the physical model (melt rates) and in the measurement model (signature of second-year ice or of frozen melt ponds) are unknown. Reasonable, but arbitrary, values of the unknown parameters are used in the examples.

  7. Preliminary Validation of Total Water Vapor Column Production of Scanning Microwave Radiometer Onboard HY-2 Satellite

    International Nuclear Information System (INIS)

    The scanning microwave radiometer (RM) was launched on August 16, 2011, onboard HY-2 satellite. As the one of primary parameters retrieved from HY-2 RM, the six-month long from Jan to Jun 2012 global total water vapor column (WV) obtained from HY-2 scanning microwave radiometer were preliminarily validated using other operational space-borne radiometer observations. The gridded water vapor productions of Special Sensor Microwave Imager (SSM/I) were seen as ''true data'' in this inter-comparison. For the global scale, the bias and RMS difference of the dataset of these space-borne collocated WV observations was respectively –0.24 mm and 1.19 mm during this six-month period. With analysis of global map of mean difference of the collocation between HY-2 RM and SSM/I, the map of bias distribution appeared that there were a positive deviation about 1mm in the tropic ocean where the precipitation and humidity were in relative high level, a negative deviation in the coastal and near-shore regions. The results suggested that accuracy of retrieval algorithm for HY-2 WV productions obviously depends on latitude. There were potential and room for improvement of retrieval accuracy of WV, for correcting overestimation of WV in the tropic sea and underestimation in the inshore regions relative to SSM/I observations

  8. Artificial Intelligent Control for a Novel Advanced Microwave Biodiesel Reactor

    International Nuclear Information System (INIS)

    Biodiesel, an alternative diesel fuel made from a renewable source, is produced by the transesterification of vegetable oil or fat with methanol or ethanol. In order to control and monitor the progress of this chemical reaction with complex and highly nonlinear dynamics, the controller must be able to overcome the challenges due to the difficulty in obtaining a mathematical model, as there are many uncertain factors and disturbances during the actual operation of biodiesel reactors. Classical controllers show significant difficulties when trying to control the system automatically. In this paper we propose a comparison of artificial intelligent controllers, Fuzzy logic and Adaptive Neuro-Fuzzy Inference System(ANFIS) for real time control of a novel advanced biodiesel microwave reactor for biodiesel production from waste cooking oil. Fuzzy logic can incorporate expert human judgment to define the system variables and their relationships which cannot be defined by mathematical relationships. The Neuro-fuzzy system consists of components of a fuzzy system except that computations at each stage are performed by a layer of hidden neurons and the neural network's learning capability is provided to enhance the system knowledge. The controllers are used to automatically and continuously adjust the applied power supplied to the microwave reactor under different perturbations. A Labview based software tool will be presented that is used for measurement and control of the full system, with real time monitoring.

  9. Artificial Intelligent Control for a Novel Advanced Microwave Biodiesel Reactor

    Science.gov (United States)

    Wali, W. A.; Hassan, K. H.; Cullen, J. D.; Al-Shamma'a, A. I.; Shaw, A.; Wylie, S. R.

    2011-08-01

    Biodiesel, an alternative diesel fuel made from a renewable source, is produced by the transesterification of vegetable oil or fat with methanol or ethanol. In order to control and monitor the progress of this chemical reaction with complex and highly nonlinear dynamics, the controller must be able to overcome the challenges due to the difficulty in obtaining a mathematical model, as there are many uncertain factors and disturbances during the actual operation of biodiesel reactors. Classical controllers show significant difficulties when trying to control the system automatically. In this paper we propose a comparison of artificial intelligent controllers, Fuzzy logic and Adaptive Neuro-Fuzzy Inference System(ANFIS) for real time control of a novel advanced biodiesel microwave reactor for biodiesel production from waste cooking oil. Fuzzy logic can incorporate expert human judgment to define the system variables and their relationships which cannot be defined by mathematical relationships. The Neuro-fuzzy system consists of components of a fuzzy system except that computations at each stage are performed by a layer of hidden neurons and the neural network's learning capability is provided to enhance the system knowledge. The controllers are used to automatically and continuously adjust the applied power supplied to the microwave reactor under different perturbations. A Labview based software tool will be presented that is used for measurement and control of the full system, with real time monitoring.

  10. Artificial Intelligent Control for a Novel Advanced Microwave Biodiesel Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Wali, W A; Hassan, K H; Cullen, J D; Al-Shamma' a, A I; Shaw, A; Wylie, S R, E-mail: w.wali@2009.ljmu.ac.uk [Built Environment and Sustainable Technologies Institute (BEST), School of the Built Environment, Faculty of Technology and Environment Liverpool John Moores University, Byrom Street, Liverpool L3 3AF (United Kingdom)

    2011-08-17

    Biodiesel, an alternative diesel fuel made from a renewable source, is produced by the transesterification of vegetable oil or fat with methanol or ethanol. In order to control and monitor the progress of this chemical reaction with complex and highly nonlinear dynamics, the controller must be able to overcome the challenges due to the difficulty in obtaining a mathematical model, as there are many uncertain factors and disturbances during the actual operation of biodiesel reactors. Classical controllers show significant difficulties when trying to control the system automatically. In this paper we propose a comparison of artificial intelligent controllers, Fuzzy logic and Adaptive Neuro-Fuzzy Inference System(ANFIS) for real time control of a novel advanced biodiesel microwave reactor for biodiesel production from waste cooking oil. Fuzzy logic can incorporate expert human judgment to define the system variables and their relationships which cannot be defined by mathematical relationships. The Neuro-fuzzy system consists of components of a fuzzy system except that computations at each stage are performed by a layer of hidden neurons and the neural network's learning capability is provided to enhance the system knowledge. The controllers are used to automatically and continuously adjust the applied power supplied to the microwave reactor under different perturbations. A Labview based software tool will be presented that is used for measurement and control of the full system, with real time monitoring.

  11. A preliminary assessment of the sea surface wind speed production of HY-2 scanning microwave radiometer

    Institute of Scientific and Technical Information of China (English)

    HUANG Xiaoqi; ZHU Jianhua; LIN Mingsen; ZHAO Yili; WANG He; CHEN Chuntao; PENG Hailong; ZHANG Youguang

    2014-01-01

    A scanning microwave radiometer (RM) was launched on August 16, 2011, on board HY-2 satellite. The six-month long global sea surface wind speeds observed by the HY-2 scanning microwave radiometer are preliminarily validated using in-situ measurements and WindSat observations, respectively, from January to June 2012. The wind speed root-mean-square (RMS) difference of the comparisons with in-situ data is 1.89 m/s for the measurements of NDBC and 1.72 m/s for the recent four-month data measured by PY30-1 oil platform, respectively. On a global scale, the wind speeds of HY-2 RM are compared with the sea surface wind speeds derived from WindSat, the RMS difference of 1.85 m/s for HY-2 RM collocated observations data set is calculated in the same period as above. With analyzing the global map of a mean difference between HY-2 RM and WindSat, it appears that the bias of the sea surface wind speed is obviously higher in the inshore regions. In the open sea, there is a relatively higher positive bias in the mid-latitude regions due to the overestimation of wind speed observations, while the wind speeds are underestimated in the Southern Ocean by HY-2 RM relative to WindSat observations.

  12. Quantitative sub-surface and non-contact imaging using scanning microwave microscopy

    International Nuclear Information System (INIS)

    The capability of scanning microwave microscopy for calibrated sub-surface and non-contact capacitance imaging of silicon (Si) samples is quantitatively studied at broadband frequencies ranging from 1 to 20 GHz. Calibrated capacitance images of flat Si test samples with varying dopant density (1015–1019 atoms cm−3) and covered with dielectric thin films of SiO2 (100–400 nm thickness) are measured to demonstrate the sensitivity of scanning microwave microscopy (SMM) for sub-surface imaging. Using standard SMM imaging conditions the dopant areas could still be sensed under a 400 nm thick oxide layer. Non-contact SMM imaging in lift-mode and constant height mode is quantitatively demonstrated on a 50 nm thick SiO2 test pad. The differences between non-contact and contact mode capacitances are studied with respect to the main parameters influencing the imaging contrast, namely the probe tip diameter and the tip–sample distance. Finite element modelling was used to further analyse the influence of the tip radius and the tip–sample distance on the SMM sensitivity. The understanding of how the two key parameters determine the SMM sensitivity and quantitative capacitances represents an important step towards its routine application for non-contact and sub-surface imaging. (paper)

  13. Scanning microwave microscope imaging of micro-patterned monolayer graphene grown by chemical vapor deposition

    Science.gov (United States)

    Myers, J.; Mou, S.; Chen, K.-H.; Zhuang, Y.

    2016-02-01

    Characterization of micro-patterned chemical vapor deposited monolayer graphene using a scanning microwave microscope has been presented. Monolayer graphene sheets deposited on a copper substrate were transferred to a variety of substrates and micro-patterned into a periodic array of parallel lines. The measured complex reflection coefficients exhibit a strong dependency on the operating frequency and on the samples' electrical conductivity and permittivity. The experiments show an extremely high sensitivity by detecting image contrast between single and double layer graphene sheets. Correlating the images recorded at the half- and quarter-wavelength resonant frequencies shows that the relative permittivity of the single layer graphene sheet is above 105. The results are in good agreement with the three dimensional numerical electromagnetic simulations. This method may be instrumental for a comprehensive understanding of the scanning microwave microscope image contrast and provide a unique technique to estimate the local electrical properties with nano-meter scale spatial resolution of two dimensional materials at radio frequency.

  14. Subsurface imaging of metal lines embedded in a dielectric with a scanning microwave microscope

    Science.gov (United States)

    You, Lin; Ahn, Jung-Joon; Obeng, Yaw S.; Kopanski, Joseph J.

    2016-02-01

    We demonstrate the ability of the scanning microwave microscope (SMM) to detect subsurface metal lines embedded in a dielectric film with sub-micrometer resolution. The SMM was used to image 1.2 μm-wide Al-Si-Cu metal lines encapsulated with either 800 nm or 2300 nm of plasma deposited silicon dioxide. Both the reflected microwave (S 11) amplitude and phase shifted near resonance frequency while the tip scanned across these buried lines. The shallower line edge could be resolved within 900 nm  ±  70 nm, while the deeper line was resolved within 1200 nm  ±  260 nm. The spatial resolution obtained in this work is substantially better that the 50 μm previously reported in the literature. Our observations agree very well with the calculated change in peak frequency and phase using a simple lumped element model for an SMM with a resonant transmission line. By conducting experiments at various eigenmodes, different contrast levels and signal-to-noise ratios have been compared. With detailed sensitivity studies, centered around 9.3 GHz, it has been revealed that the highest amplitude contrast is obtained when the probe microwave frequency matches the exact resonance frequency of the experimental setup. By RLC equivalent circuit modeling of the tip-sample system, two competing effects have been identified to account for the positive and negative S 11 amplitude and phase contrasts, which can be leveraged to further improve the contrast and resolution. Official contribution of the National Institute of Standards and Technology; not subject to copyright in the United States.

  15. Subsurface imaging of metal lines embedded in a dielectric with a scanning microwave microscope

    International Nuclear Information System (INIS)

    We demonstrate the ability of the scanning microwave microscope (SMM) to detect subsurface metal lines embedded in a dielectric film with sub-micrometer resolution. The SMM was used to image 1.2 μm-wide Al–Si–Cu metal lines encapsulated with either 800 nm or 2300 nm of plasma deposited silicon dioxide. Both the reflected microwave (S 11) amplitude and phase shifted near resonance frequency while the tip scanned across these buried lines. The shallower line edge could be resolved within 900 nm  ±  70 nm, while the deeper line was resolved within 1200 nm  ±  260 nm. The spatial resolution obtained in this work is substantially better that the 50 μm previously reported in the literature. Our observations agree very well with the calculated change in peak frequency and phase using a simple lumped element model for an SMM with a resonant transmission line. By conducting experiments at various eigenmodes, different contrast levels and signal-to-noise ratios have been compared. With detailed sensitivity studies, centered around 9.3 GHz, it has been revealed that the highest amplitude contrast is obtained when the probe microwave frequency matches the exact resonance frequency of the experimental setup. By RLC equivalent circuit modeling of the tip-sample system, two competing effects have been identified to account for the positive and negative S 11 amplitude and phase contrasts, which can be leveraged to further improve the contrast and resolution. (paper)

  16. Surface scanning through a cylindrical tank of coupling fluid for clinical microwave breast imaging exams

    International Nuclear Information System (INIS)

    Purpose: Microwave tomographic image quality can be improved significantly with prior knowledge of the breast surface geometry. The authors have developed a novel laser scanning system capable of accurately recovering surface renderings of breast-shaped phantoms immersed within a cylindrical tank of coupling fluid which resides completely external to the tank (and the aqueous environment) and overcomes the challenges associated with the optical distortions caused by refraction from the air, tank wall, and liquid bath interfaces. Methods: The scanner utilizes two laser line generators and a small CCD camera mounted concentrically on a rotating gantry about the microwave imaging tank. Various calibration methods were considered for optimizing the accuracy of the scanner in the presence of the optical distortions including traditional ray tracing and image registration approaches. In this paper, the authors describe the construction and operation of the laser scanner, compare the efficacy of several calibration methods—including analytical ray tracing and piecewise linear, polynomial, locally weighted mean, and thin-plate-spline (TPS) image registrations—and report outcomes from preliminary phantom experiments. Results: The results show that errors in calibrating camera angles and position prevented analytical ray tracing from achieving submillimeter accuracy in the surface renderings obtained from our scanner configuration. Conversely, calibration by image registration reliably attained mean surface errors of less than 0.5 mm depending on the geometric complexity of the object scanned. While each of the image registration approaches outperformed the ray tracing strategy, the authors found global polynomial methods produced the best compromise between average surface error and scanner robustness. Conclusions: The laser scanning system provides a fast and accurate method of three dimensional surface capture in the aqueous environment commonly found in microwave

  17. Land Surface Microwave Emissivities Derived from AMSR-E and MODIS Measurements with Advanced Quality Control

    Science.gov (United States)

    Moncet, Jean-Luc; Liang, Pan; Galantowicz, John F.; Lipton, Alan E.; Uymin, Gennady; Prigent, Catherine; Grassotti, Christopher

    2011-01-01

    A microwave emissivity database has been developed with data from the Advanced Microwave Scanning Radiometer-EOS (AMSR-E) and with ancillary land surface temperature (LST) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) on the same Aqua spacecraft. The primary intended application of the database is to provide surface emissivity constraints in atmospheric and surface property retrieval or assimilation. An additional application is to serve as a dynamic indicator of land surface properties relevant to climate change monitoring. The precision of the emissivity data is estimated to be significantly better than in prior databases from other sensors due to the precise collocation with high-quality MODIS LST data and due to the quality control features of our data analysis system. The accuracy of the emissivities in deserts and semi-arid regions is enhanced by applying, in those regions, a version of the emissivity retrieval algorithm that accounts for the penetration of microwave radiation through dry soil with diurnally varying vertical temperature gradients. These results suggest that this penetration effect is more widespread and more significant to interpretation of passive microwave measurements than had been previously established. Emissivity coverage in areas where persistent cloudiness interferes with the availability of MODIS LST data is achieved using a classification-based method to spread emissivity data from less-cloudy areas that have similar microwave surface properties. Evaluations and analyses of the emissivity products over homogeneous snow-free areas are presented, including application to retrieval of soil temperature profiles. Spatial inhomogeneities are the largest in the vicinity of large water bodies due to the large water/land emissivity contrast and give rise to large apparent temporal variability in the retrieved emissivities when satellite footprint locations vary over time. This issue will be dealt with in the future by

  18. H Scan/AHP advanced technology proposal evaluation process

    Energy Technology Data Exchange (ETDEWEB)

    Mack, S. [Energetics, Inc., Columbia, MD (United States); Valladares, M.R.S. de [National Renewable Energy Lab., Washington, DC (United States)

    1996-10-01

    It is anticipated that a family of high value/impact projects will be funded by the Hydrogen Program to field test hydrogen technologies that are at advanced stages of development. These projects will add substantial value to the Program in several ways, by: demonstrating successful integration of multiple advanced technologies, providing critical insight on issues of larger scale equipment design, construction and operations management, yielding cost and performance data for competitive analysis, refining and deploying enhanced safety measures. These projects will be selected through a competitive proposal evaluation process. Because of the significant scope and funding levels of projects at these development phases, Program management has indicated the need for an augmented proposal evaluation strategy to ensure that supported projects are implemented by capable investigative teams and that their successful completion will optimally advance programmatic objectives. These objectives comprise a complex set of both quantitative and qualitative factors, many of which can only be estimated using expert judgment and opinion. To meet the above need, the National Renewable Energy Laboratory (NREL) and Energetics Inc. have jointly developed a proposal evaluation methodology called H Scan/AHP. The H Scan component of the process was developed by NREL. It is a two-part survey instrument that substantially augments the type and scope of information collected in a traditional proposal package. The AHP (Analytic Hierarchy Process) component was developed by Energetics. The AHP is an established decision support methodology that allows the Program decision makers to evaluate proposals relatively based on a unique set of weighted criteria that they have determined.

  19. Scanning Microwave Radiometry for Investigating Water Vapor and Cloud Distributions (Invited)

    Science.gov (United States)

    Crewell, S.; Kneifel, S.; Löhnert, U.; Schween, J.

    2010-12-01

    Ground-based microwave radiometry (MWR) is one of the most promising methods for observing cloud liquid, humidity and temperature as it is a robust, highly automated technique for nearly all weather conditions. Typically, multi-frequency observations between 20 and 90 GHz are performed in zenith direction. The major limitation of such MWR observations is the limited vertical resolution providing only 2-3 independent pieces of information for water vapor and temperature (Löhnert et al., 2009). For cloud liquid the situation is worse due to the relatively low dependance of cloud emissivity on temperature. In principal only the total column - the liquid water path (LWP) can be retrieved. Elevation scanning is commonly used to improve the vertical resolution of temperature profiles in the boundary layer assuming its horizontal homogeneity. Volume scanning, i.e. azimuth and elevation scanning has the potential to investigate the 3D distribution of water vapor and clouds. During the deployment of the ARM Mobile Facility in the Murg Valley, Black Forest, Germany routine azimuth scanning MWR could reveal the increase in average LWP above hill crests compared to the standard zenith observations within the valley. Recently, we could demonstrate the feasibility of detecting horizontal humidity gradients from a single scanning MWR (Schween et al., 2010). Another interesting application of scanning MWR is the use of azimuthal water vapor variability as a proxy for convective activity. For example during fair weather conditions the increase in turbulent mixing after sunrise building up the boundary layer can be detected well from the azimuthal water vapor variations at low elevation angles. The presentation will provide an overview of the capabilities of MWR for the detection of 3D structures by analyzing the information content of the measurements and deriving retrieval methods. In addition, examples from multi-year scanning observations at different locations will be shown to

  20. The Study of Near-field Scanning Microwave Microscope for the Nondestructive Detection System

    International Nuclear Information System (INIS)

    We described a near-field scanning microwave microscope which uses a high-quality dielectric resonator with a tunable screw. The operating frequency is f=4.5 5GHz. The probe tip is mounted in a cylindrical resonant cavity coupled to a dielectric resonator We developed a hybrid tip combining a reduced length of the tapered part with a small apex. In order to understand the function of the probe, we fabricated three different tips using a conventional chemical etching technique and observed three different NSMM images for patterned Cr films on glass substrates. We measured the reflection coefficient of different metal thin film samples with the same thickness of 300m and compared with theoretical impedance respectly. By tuning the tunable screw coming through the top cover, we could improve sensitivity, signal-to-noise ratio, and spatial resolution to better than 1μm. To demonstrate the ability of local microwave characterization, the surface resistance of metallic thin films has been mapped

  1. Evaluation of wood characteristics: internal scanning of the material by microwaves

    International Nuclear Information System (INIS)

    Internal scanning of wood by microwaves presents many advantages for the automatic detection of defects and the evaluation of the characteristics of wood in the dry wood processing industries. Advantages are: access to more than one variable, efficient coupling in the air, easy automation and reasonable cost. Microwaves are electromagnetic waves the speed and attenuation of which depend of the medium in which they are propagated, especially its electric permittivity which depends on its moisture content and its density. Since wood is anisotropic, this dielectric constant also varies with the direction of fibers. An experimental apparatus was set up that allows to test the feasibility of automatic detection of wood characteristics and defects. It automatically measures the attenuation and dephasing of an ultra high frequency wave sent through a board and moving through two rotating antennas. The graphs and results obtained gave significant information of physical characteristics of wood (density, moisture content, slope of grain) and the detection of defects (knots, metallic objects, sapwood)

  2. Modeling and de-embedding the interferometric scanning microwave microscopy by means of dopant profile calibration

    Energy Technology Data Exchange (ETDEWEB)

    Michalas, L., E-mail: loukas.michalas@artov.imm.cnr.it; Marcelli, R. [National Research Council, Institute for Microelectronics and Microsystems (CNR-IMM), Via del Fosso del Cavaliere 100, 00133 Rome (Italy); Wang, F.; Brillard, C.; Theron, D. [Institut d' Electronique, de Microélectronique et de Nanotechnologie, CNRS UMR 8520/University of Lille 1, Avenue Poincaré, CS 60069, 59652 Villeneuve d' Ascq (France); Chevalier, N.; Hartmann, J. M. [Univ. Grenoble Alpes, F-38000 Grenoble, France and CEA, LETI, MINATEC Campus, F-38054 Grenoble (France)

    2015-11-30

    This paper presents the full modeling and a methodology for de-embedding the interferometric scanning microwave microscopy measurements by means of dopant profile calibration. A Si calibration sample with different boron-doping level areas is used to that end. The analysis of the experimentally obtained S{sub 11} amplitudes based on the proposed model confirms the validity of the methodology. As a specific finding, changes in the tip radius between new and used tips have been clearly identified, leading to values for the effective tip radius in the range of 45 nm to 85 nm, respectively. Experimental results are also discussed in terms of the effective area concept, taking into consideration details related to the nature of tip-to-sample interaction.

  3. Advanced Passive Microwave Radiometer Technology for GPM Mission

    Science.gov (United States)

    Smith, Eric A.; Im, Eastwood; Kummerow, Christian; Principe, Caleb; Ruf, Christoper; Wilheit, Thomas; Starr, David (Technical Monitor)

    2002-01-01

    An interferometer-type passive microwave radiometer based on MMIC receiver technology and a thinned array antenna design is being developed under the Instrument Incubator Program (TIP) on a project entitled the Lightweight Rainfall Radiometer (LRR). The prototype single channel aircraft instrument will be ready for first testing in 2nd quarter 2003, for deployment on the NASA DC-8 aircraft and in a ground configuration manner; this version measures at 10.7 GHz in a crosstrack imaging mode. The design for a two (2) frequency preliminary space flight model at 19 and 35 GHz (also in crosstrack imaging mode) has also been completed, in which the design features would enable it to fly in a bore-sighted configuration with a new dual-frequency space radar (DPR) under development at the Communications Research Laboratory (CRL) in Tokyo, Japan. The DPR will be flown as one of two primary instruments on the Global Precipitation Measurement (GPM) mission's core satellite in the 2007 time frame. The dual frequency space flight design of the ERR matches the APR frequencies and will be proposed as an ancillary instrument on the GPM core satellite to advance space-based precipitation measurement by enabling better microphysical characterization and coincident volume data gathering for exercising combined algorithm techniques which make use of both radar backscatter and radiometer attenuation information to constrain rainrate solutions within a physical algorithm context. This talk will discuss the design features, performance capabilities, applications plans, and conical/polarametric imaging possibilities for the LRR, as well as a brief summary of the project status and schedule.

  4. Microwave Processing of Simulated Advanced Nuclear Fuel Pellets

    International Nuclear Information System (INIS)

    Throughout the three-year project funded by the Department of Energy (DOE) and lead by Virginia Tech (VT), project tasks were modified by consensus to fit the changing needs of the DOE with respect to developing new inert matrix fuel processing techniques. The focus throughout the project was on the use of microwave energy to sinter fully stabilized zirconia pellets using microwave energy and to evaluate the effectiveness of techniques that were developed. Additionally, the research team was to propose fundamental concepts as to processing radioactive fuels based on the effectiveness of the microwave process in sintering the simulated matrix material.

  5. Recent advancement of slow light in microwave photonics applications

    OpenAIRE

    Chin, Sanghoon; Thévenaz, Luc

    2010-01-01

    A complete realization of an optically tunable true time delay, generated through the combination of a photonic RF phase shifter and a Brillouin slow light element is presented. Illustration through a dynamic microwave photonic filter is demonstrated.

  6. A Survey of Advanced Microwave Frequency Measurement Techniques

    OpenAIRE

    Anand Swaroop Khare,

    2012-01-01

    Microwaves are radio waves with wavelengths ranging from as long as one meter to as short as one millimeter, or equivalently, with frequencies between 300 MHz and 300 GHz. The science of photonics includes the generation, emission, modulation, signal processing, switching, transmission, amplification, detection and sensing of light. Microwave photonics has been introduced for achieving ultra broadband signal processing. Instantaneous Frequency Measurement (IFM) receivers play an important ro...

  7. Handbook of microwave component measurements with advanced VNA techniques

    CERN Document Server

    Dunsmore, Joel P

    2012-01-01

    This book provides state-of-the-art coverage for making measurements on RF and Microwave Components, both active and passive. A perfect reference for R&D and Test Engineers, with topics ranging from the best practices for basic measurements, to an in-depth analysis of errors, correction methods, and uncertainty analysis, this book provides everything you need to understand microwave measurements. With primary focus on active and passive measurements using a Vector Network Analyzer, these techniques and analysis are equally applicable to measurements made with Spectrum Analyzers or Noise Figure

  8. Quantitative impedance characterization of sub-10 nm scale capacitors and tunnel junctions with an interferometric scanning microwave microscope

    International Nuclear Information System (INIS)

    We present a method to characterize sub-10 nm capacitors and tunnel junctions by interferometric scanning microwave microscopy (iSMM) at 7.8 GHz. At such device scaling, the small water meniscus surrounding the iSMM tip should be reduced by proper tip tuning. Quantitative impedance characterization of attofarad range capacitors is achieved using an ‘on-chip’ calibration kit facing thousands of nanodevices. Nanoscale capacitors and tunnel barriers were detected through variations in the amplitude and phase of the reflected microwave signal, respectively. This study promises quantitative impedance characterization of a wide range of emerging functional nanoscale devices. (paper)

  9. Design and Implementation of a Mechanical Control System for the Scanning Microwave Limb Sounder

    Science.gov (United States)

    Bowden, William

    2011-01-01

    The Scanning Microwave Limb Sounder (SMLS) will use technological improvements in low noise mixers to provide precise data on the Earth's atmospheric composition with high spatial resolution. This project focuses on the design and implementation of a real time control system needed for airborne engineering tests of the SMLS. The system must coordinate the actuation of optical components using four motors with encoder readback, while collecting synchronized telemetric data from a GPS receiver and 3-axis gyrometric system. A graphical user interface for testing the control system was also designed using Python. Although the system could have been implemented with a FPGA-based setup, we chose to use a low cost processor development kit manufactured by XMOS. The XMOS architecture allows parallel execution of multiple tasks on separate threads-making it ideal for this application and is easily programmed using XC (a subset of C). The necessary communication interfaces were implemented in software, including Ethernet, with significant cost and time reduction compared to an FPGA-based approach. For these reasons, the XMOS technology is an attractive, cost effective, alternative to FPGA-based technologies for this design and similar rapid prototyping projects.

  10. Microwave dynamic large signal waveform characterization of advanced InGaP HBT for power amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Lixin; Jin Zhi; Liu Xinyu, E-mail: zhaolixin@ime.ac.c [Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029 (China)

    2009-12-15

    In wireless mobile communications and wireless local area networks (WLAN), advanced InGaP HBT with power amplifiers are key components. In this paper, the microwave large signal dynamic waveform characteristics of an advanced InGaP HBT are investigated experimentally for 5.8 GHz power amplifier applications. The microwave large signal waveform distortions at various input power levels, especially at large signal level, are investigated and the reasons are analyzed. The output power saturation is also explained. These analyses will be useful for power amplifier designs. (semiconductor devices)

  11. Microwave dynamic large signal waveform characterization of advanced InGaP HBT for power amplifiers

    International Nuclear Information System (INIS)

    In wireless mobile communications and wireless local area networks (WLAN), advanced InGaP HBT with power amplifiers are key components. In this paper, the microwave large signal dynamic waveform characteristics of an advanced InGaP HBT are investigated experimentally for 5.8 GHz power amplifier applications. The microwave large signal waveform distortions at various input power levels, especially at large signal level, are investigated and the reasons are analyzed. The output power saturation is also explained. These analyses will be useful for power amplifier designs. (semiconductor devices)

  12. Advances in Modeling of Scanning Charged-Particle-Microscopy Images

    OpenAIRE

    Cizmar, Petr; Vladar, Andras E.; Postek, Michael T.

    2010-01-01

    Modeling artificial scanning electron microscope (SEM) and scanning ion microscope images has recently become important. This is because of the need to provide repeatable images with a priori determined parameters. Modeled artificial images are highly useful in the evaluation of new imaging and metrological techniques, like image-sharpness calculation, or drift-corrected image composition (DCIC). Originally, the NIST-developed artificial image generator was designed only to produce the SEM im...

  13. Advanced gamma ray technology for scanning cargo containers.

    Science.gov (United States)

    Orphan, Victor J; Muenchau, Ernie; Gormley, Jerry; Richardson, Rex

    2005-01-01

    The shipping industry is striving to increase security for cargo containers without significantly impeding traffic. Three Science Applications International Corporation (SAIC) development programs are supporting this effort. SAIC's ICIS system combines SAIC's VACIS gamma ray imaging, radiation scanning, OCR, elemental analysis and other technologies to scan containers for nuclear materials and other hazards in normal terminal traffic. SAIC's enhanced gamma ray detector improves VACIS image resolution by a factor of three. And SAIC's EmptyView software analyzes VACIS images to automatically verify empty containers. PMID:15996470

  14. Advanced γ ray technology for scanning cargo containers

    International Nuclear Information System (INIS)

    The shipping industry is striving to increase security for cargo containers without significantly impeding traffic. Three Science Applications International Corporation (SAIC) development programs are supporting this effort. SAIC's ICIS system combines SAIC's VACIS[reg] γ ray imaging, radiation scanning, OCR, elemental analysis and other technologies to scan containers for nuclear materials and other hazards in normal terminal traffic. SAIC's enhanced γ ray detector improves VACIS image resolution by a factor of three. And SAIC's EmptyView software analyzes VACIS images to automatically verify empty containers

  15. Calibration of Suomi national polar-orbiting partnership advanced technology microwave sounder

    Science.gov (United States)

    Weng, Fuzhong; Zou, Xiaolei; Sun, Ninghai; Yang, Hu; Tian, Miao; Blackwell, William J.; Wang, Xiang; Lin, Lin; Anderson, Kent

    2013-10-01

    The Suomi National Polar-Orbiting Partnership (NPP) satellite was launched on 28 October 2011 and carries the Advanced Technology Microwave Sounder (ATMS) on board. ATMS is a cross-track scanning instrument observing in 22 channels at frequencies ranging from 23 to 183 GHz, permitting the measurements of the atmospheric temperature and moisture under most weather conditions. In this study, the ATMS radiometric calibration algorithm used in the operational system is first evaluated through independent analyses of prelaunch thermal vacuum data. It is found that the ATMS peak nonlinearity for all the channels is less than 0.5 K, which is well within the specification. For the characterization of the ATMS instrument sensitivity or noise equivalent differential temperatures (NEDT), both standard deviation and Allan variance of warm counts are computed and compared. It is shown that NEDT derived from the standard deviation is about three to five times larger than that from the Allan variance. The difference results from a nonstationary component in the standard deviation of warm counts. The Allan variance is better suited than the standard deviation for describing NEDT. In the ATMS sensor brightness temperature data record (SDR) processing algorithm, the antenna gain efficiencies of main beam, cross-polarization beam, and side lobes must be derived accurately from the antenna gain distribution function. However, uncertainties remain in computing the efficiencies at ATMS high frequencies. Thus, ATMS antenna brightness temperature data records (TDR) at channels 1 to 15 are converted to SDR with the actual beam efficiencies whereas those for channels 16 to 22 are only corrected for the near-field sidelobe contributions. The biases of ATMS SDR measurements to the simulations are consistent between GPS RO and NWP data and are generally less than 0.5 K for those temperature-sounding channels where both the forward model and input atmospheric profiles are reliable.

  16. Mid-Resolution Microwave Scanning Radiometer%中分辨率微波扫描辐射仪

    Institute of Scientific and Technical Information of China (English)

    李开明

    2001-01-01

    The mid-resolution microwave scanning radiometer is a conical scanning total power radiometer with a fixed visual angle and double-reference temperature. The operational concept, sighting direction and scanning way, band selection and system structure are described. The space feed technique, microwave receiver, calibration technique, data collection & processing, driving & transmission, power source and heat control are also analyzed.%仪器实施的方案为固定视角圆锥扫描双参考温度外部两点式周期定标全功率型。论述了它的工作原理、视向与扫描方式、频段选择和总体构形。同时对天馈技术、微波接收机、定标技术、数据采集与处理、驱动与传输、电源、热控制等技术进行了分析。

  17. Nanomaterial datasets to advance tomography in scanning transmission electron microscopy

    OpenAIRE

    Levin, Barnaby D.A.; Padgett, Elliot; Chen, Chien-Chun; Scott, M C; Xu, Rui; Theis, Wolfgang; Jiang, Yi; Yang, Yongsoo; Ophus, Colin; Zhang, Haitao; Ha, Don-Hyung; Wang, Deli; Yu, Yingchao; Abruña, Hector D.; Richard D Robinson

    2016-01-01

    Electron tomography in materials science has flourished with the demand to characterize nanoscale materials in three dimensions (3D). Access to experimental data is vital for developing and validating reconstruction methods that improve resolution and reduce radiation dose requirements. This work presents five high-quality scanning transmission electron microscope (STEM) tomography datasets in order to address the critical need for open access data in this field. The datasets represent the cu...

  18. A New ERA in Global Temperature Monitoring with the Advanced Microwave Sounding Unit (AMSU)

    Science.gov (United States)

    Spencer, Roy W.; Braswell, William D.; Christy, John R.

    1999-01-01

    The launch of the first Advanced Microwave Sounding Unit (AMSU) on the NOAA-15 spacecraft on 13 May 1998 marked a significant advance in our ability to monitor global temperatures. Compared to the Microwave Sounding Units (MSU) flying since 1978 on the TIROS-N series of NOAA polar orbiters, the AMSU offers better horizontal, vertical, and radiometric resolutions. It will allow routine monitoring of 1 1 (mostly) separate layers, compared to 2 or 3 with the MSU, including layers in the middle and upper stratosphere (2.5 hPa) where increasing carbon dioxide concentrations should be causing a cooling rate of about 1 deg. C per decade. More precise limb corrections combined with low noise will allow identification of subtle spatial temperature patterns associated with global cyclone activity.

  19. WindSat Passive Microwave Soil Moisture Retrievals

    Science.gov (United States)

    Technical Abstract: WindSat is a spaceborne fully polarimetric conical scanning microwave radiometer. It operates at frequencies and polarizations that match other radiometers such as the Advanced Microwave Scanning Radiometer (AMSR-E) and in addition it acquires additional polarimetric measurements...

  20. Advanced Treatment of Pesticide-Containing Wastewater Using Fenton Reagent Enhanced by Microwave Electrodeless Ultraviolet

    OpenAIRE

    Gong Cheng; Jing Lin; Jian Lu; Xi Zhao; Zhengqing Cai; Jie Fu

    2015-01-01

    The photo-Fenton reaction is a promising method to treat organic contaminants in water. In this paper, a Fenton reagent enhanced by microwave electrodeless ultraviolet (MWEUV/Fenton) method was proposed for advanced treatment of nonbiodegradable organic substance in pesticide-containing biotreated wastewater. MWEUV lamp was found to be more effective for chemical oxygen demand (COD) removal than commercial mercury lamps in the Fenton process. The pseudo-first order kinetic model can well desc...

  1. Artificial neural network approach for estimation of surface specific humidity and air temperature using Multifrequency Scanning Microwave Radiometer

    Indian Academy of Sciences (India)

    Randhir Singh; B G Vasudevan; P K Pal; P C Joshi

    2004-03-01

    Microwave sensor MSMR (Multifrequency Scanning Microwave Radiometer) data onboard Oceansat-1 was used for retrieval of monthly averages of near surface specific humidity (a) and air temperature (a) by means of Artificial Neural Network (ANN). The MSMR measures the microwave radiances in 8 channels at frequencies of 6.6, 10.7, 18 and 21 GHz for both vertical and horizontal polarizations. The artificial neural networks (ANN) technique is employed to find the transfer function relating the input MSMR observed brightness temperatures and output (a and a) parameters. Input data consist of nearly 28 months (June 1999 — September 2001) of monthly averages of MSMR observed brightness temperature and surface marine observations of a and a from Comprehensive Ocean- Atmosphere Data Set (COADS). The performance of the algorithm is assessed with independent surface marine observations. The results indicate that the combination of MSMR observed brightness temperatures as input parameters provides reasonable estimates of monthly averaged surface parameters. The global root mean square (rms) differences are 1.0°C and 1.1 g kg−1 for air temperature and surface specific humidity respectively.

  2. Nanomaterial datasets to advance tomography in scanning transmission electron microscopy

    CERN Document Server

    Levin, Barnaby D A; Chen, Chien-Chun; Scott, M C; Xu, Rui; Theis, Wolfgang; Jiang, Yi; Yang, Yongsoo; Ophus, Colin; Zhang, Haitao; Ha, Don-Hyung; Wang, Deli; Yu, Yingchao; Abruna, Hector D; Robinson, Richard D; Ercius, Peter; Kourkoutis, Lena F; Miao, Jianwei; Muller, David A; Hovden, Robert

    2016-01-01

    Electron tomography in materials science has flourished with the demand to characterize nanoscale materials in three dimensions (3D). Access to experimental data is vital for developing and validating reconstruction methods that improve resolution and reduce radiation dose requirements. This work presents five high-quality scanning transmission electron microscope (STEM) tomography datasets in order to address the critical need for open access data in this field. The datasets represent the current limits of experimental technique, are of high quality, and contain materials with structural complexity. Included are tomographic series of a hyperbranched Co2P nanocrystal, platinum nanoparticles on a carbon nanofibre imaged over the complete 180{\\deg} tilt range, a platinum nanoparticle and a tungsten needle both imaged at atomic resolution by equal slope tomography, and a through-focal tilt series of PtCu nanoparticles. A volumetric reconstruction from every dataset is provided for comparison and development of p...

  3. Advances in Atomic Force Microscopy and Scanning Tunneling Microscopy

    Science.gov (United States)

    Albrecht, Thomas Robert

    The scanning tunneling microscope (STM) and the more recently developed atomic force microscope (AFM) are high resolution scanning probe microscopes capable of three dimensional atomic-scale surface profiling. In the AFM, minute forces acting between the tip of a flexible cantilever stylus and the surface of the sample cause deflections of the cantilever which are detected by a tunneling or optical sensor with subangstrom sensitivity. The AFM work presented here involves surface profiling via repulsive contact forces between 10^{-6} and 10^{-9} N in magnitude. In this contact profiling (repulsive) mode the AFM is capable of atomic resolution on both electrically conducting and insulating surfaces (unlike the STM). AFM instrumentation for room temperature and low temperature operation is discussed. The critical component of the AFM is the cantilever stylus assembly, which should have a small mass. Several microfabrication processes have been developed to produce thin film SiO_2 and Si_3N_4 microcantilevers with integrated sharp tips. Atomic resolution has been achieved with the AFM in air on a number of samples, including graphite, MoS _2, TaSe_2, WTe_2, TaS_2, and BN (the first insulator imaged with atomic resolution by any means). Various organic and molecular samples have been imaged with nanometer resolution. The difference between STM and AFM response is shown in images of TaS _2 (a charge density wave material), and in simultaneous STM/AFM images of lattice defects and adsorbates on graphite and MoS_2. A number of artifacts make STM and AFM image interpretation subtle, such as tip shape effects, frictional effects, and tracking in atomic grooves. STM images of moire patterns near grain boundaries confirm the importance of tip shape effects. Various surface modification and lithography techniques have been demonstrated with the STM and AFM, including an STM voltage pulse technique which reproducibly creates 40 A diameter holes on the surface of graphite, and a

  4. Nanomaterial datasets to advance tomography in scanning transmission electron microscopy.

    Science.gov (United States)

    Levin, Barnaby D A; Padgett, Elliot; Chen, Chien-Chun; Scott, M C; Xu, Rui; Theis, Wolfgang; Jiang, Yi; Yang, Yongsoo; Ophus, Colin; Zhang, Haitao; Ha, Don-Hyung; Wang, Deli; Yu, Yingchao; Abruña, Hector D; Robinson, Richard D; Ercius, Peter; Kourkoutis, Lena F; Miao, Jianwei; Muller, David A; Hovden, Robert

    2016-01-01

    Electron tomography in materials science has flourished with the demand to characterize nanoscale materials in three dimensions (3D). Access to experimental data is vital for developing and validating reconstruction methods that improve resolution and reduce radiation dose requirements. This work presents five high-quality scanning transmission electron microscope (STEM) tomography datasets in order to address the critical need for open access data in this field. The datasets represent the current limits of experimental technique, are of high quality, and contain materials with structural complexity. Included are tomographic series of a hyperbranched Co2P nanocrystal, platinum nanoparticles on a carbon nanofibre imaged over the complete 180° tilt range, a platinum nanoparticle and a tungsten needle both imaged at atomic resolution by equal slope tomography, and a through-focal tilt series of PtCu nanoparticles. A volumetric reconstruction from every dataset is provided for comparison and development of post-processing and visualization techniques. Researchers interested in creating novel data processing and reconstruction algorithms will now have access to state of the art experimental test data. PMID:27272459

  5. High altitude airborne remote sensing mission using the advanced microwave precipitation radiometer (AMPR)

    Science.gov (United States)

    Galliano, J.; Platt, R. H.; Spencer, Roy; Hood, Robbie

    1991-01-01

    The advanced microwave precipitation radiometer (AMPR) is an airborne multichannel imaging radiometer used to better understand how the earth's climate structure works. Airborne data results from the October 1990 Florida thunderstorm mission in Jacksonville, FL, are described. AMPR data on atmospheric precipitation in mesoscale storms were retrieved at 10.7, 19.35, 37.1, and 85.5 GHz onboard the ER-2 aircraft at an altitude of 20 km. AMPR's three higher-frequency data channels were selected to operate at the same frequencies as the spaceborne special sensor microwave/imager (SSM/I) presently in orbit. AMPR uses two antennas to receive the four frequencies: the lowest frequency channel uses a 9.7-in aperture lens antennas, while the three higher-frequency channels share a separate 5.3-in aperture lens antenna. The radiometer's temperature resolution performance is summarized.

  6. A deployable 4-meter 180 to 680 GHz antenna for the Scanning Microwave Limb Sounder Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Build and test a full size (4x2 meter aperture) breadboard antenna for SMLS. Demonstrate critical azimuth scanning capability of a 4m SMLS antenna and its...

  7. Assessment of the initial sea surface temperature product of the scanning microwave radiometer aboard on HY-2 satellite

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yili; ZHU Jianhua; LIN Mingsen; CHEN Chuntao; HUANG Xiaoqi; WANG He; ZHANG Youguang; PENG Hailong

    2014-01-01

    HY-2 satellite is the first satellite for dynamic environmental parameters measurement of China, which was launched on 16th August 2011. A scanning microwave radiometer (RM) is carried for sea surface temper-ature (SST), sea surface wind speed, columnar water vapor and columnar cloud liquid water detection. In this paper, the initial SST product of RM was validated with in-situ data of National Data of Buoy Center (NDBC) mooring and Argo buoy. The validation results indicate the accuracy of RM SST is better than 1.7◦C. The comparison of RM SST and WindSat SST shows the former is warmer than the latter at high sea sur-face wind speed and the difference between these SSTs is depend on the sea surface wind speed. Then, the relationship between the errors of RM SST and sea surface wind speed was analyzed using NDBC mooring measurements. Based on the results of assessment and errors analysis, the suggestions of taking accoun-t of the affection of sea surface wind speed and using sea surface wind speed and direction derived from the microwave scatteromter aboard on HY-2 for SST product calibration were given for retrieval algorithm improvement.

  8. Percutaneous microwave ablation combined with simultaneous transarterial chemoembolization for the treatment of advanced intrahepatic cholangiocarcinoma

    Directory of Open Access Journals (Sweden)

    Yang GW

    2015-05-01

    Full Text Available Guo-Wei Yang,* Qing Zhao,* Sheng Qian, Liang Zhu, Xu-Dong Qu, Wei Zhang, Zhi-Ping Yan, Jie-Min Cheng, Qing-Xin Liu, Rong Liu, Jian-Hua Wang Department of Interventional Radiology, Zhongshan Hospital, Fudan University, Shanghai, People’s Republic of China *These authors contributed equally to this work Aim: To retrospectively evaluate the safety and efficacy of ultrasound-guided percutaneous microwave ablation (MWA combined with simultaneous transarterial chemoembolization (TACE in the treatment of patients with advanced intrahepatic cholangiocarcinoma (ICC.Methods: All patients treated with ultrasound-guided percutaneous MWA combined with simultaneous TACE for advanced ICC at our institution were included. Posttreatment contrast-enhanced computed tomography and/or magnetic resonance imaging were retrieved and reviewed for tumor response to the treatment. Routine laboratory studies, including hematology and liver function tests were collected and analyzed. Procedure-related complications were reviewed and survival rates were analyzed.Results: From January 2011 to December 2014, a total of 26 advanced ICC patients were treated at our single institute with ultrasound-guided percutaneous MWA combined with simultaneous TACE. There were 15 males and eleven females with an average age of 57.9±10.4 years (range, 43–75 years. Of 26 patients, 20 (76.9% patients were newly diagnosed advanced ICC without any treatment, and six (23.1% were recurrent and treated with surgical resection of the original tumor. The complete ablation rate was 92.3% (36/39 lesions for advanced ICC. There were no major complications observed. There was no death directly from the treatment. Median progression-free survival and overall survival were 6.2 and 19.5 months, respectively. The 6-, 12-, and 24-month survival rates were 88.5%, 69.2%, and 61.5%, respectively.Conclusion: The study suggests that ultrasound-guided percutaneous MWA combined with simultaneous TACE

  9. Percutaneous microwave ablation combined with simultaneous transarterial chemoembolization for the treatment of advanced intrahepatic cholangiocarcinoma

    Science.gov (United States)

    Yang, Guo-Wei; Zhao, Qing; Qian, Sheng; Zhu, Liang; Qu, Xu-Dong; Zhang, Wei; Yan, Zhi-Ping; Cheng, Jie-Min; Liu, Qing-Xin; Liu, Rong; Wang, Jian-Hua

    2015-01-01

    Aim To retrospectively evaluate the safety and efficacy of ultrasound-guided percutaneous microwave ablation (MWA) combined with simultaneous transarterial chemoembolization (TACE) in the treatment of patients with advanced intrahepatic cholangiocarcinoma (ICC). Methods All patients treated with ultrasound-guided percutaneous MWA combined with simultaneous TACE for advanced ICC at our institution were included. Posttreatment contrast-enhanced computed tomography and/or magnetic resonance imaging were retrieved and reviewed for tumor response to the treatment. Routine laboratory studies, including hematology and liver function tests were collected and analyzed. Procedure-related complications were reviewed and survival rates were analyzed. Results From January 2011 to December 2014, a total of 26 advanced ICC patients were treated at our single institute with ultrasound-guided percutaneous MWA combined with simultaneous TACE. There were 15 males and eleven females with an average age of 57.9±10.4 years (range, 43–75 years). Of 26 patients, 20 (76.9%) patients were newly diagnosed advanced ICC without any treatment, and six (23.1%) were recurrent and treated with surgical resection of the original tumor. The complete ablation rate was 92.3% (36/39 lesions) for advanced ICC. There were no major complications observed. There was no death directly from the treatment. Median progression-free survival and overall survival were 6.2 and 19.5 months, respectively. The 6-, 12-, and 24-month survival rates were 88.5%, 69.2%, and 61.5%, respectively. Conclusion The study suggests that ultrasound-guided percutaneous MWA combined with simultaneous TACE therapy can be performed safely in all patients with advanced ICC. The complete ablation rate was high and there was no major complication. The overall 24-month survival was 61.5%. PMID:26060410

  10. Scanning Laser Polarimetry for Measurement of Retinal Nerve Fiber Layer in Absolute, Advanced and Early Glaucoma

    Directory of Open Access Journals (Sweden)

    Jen-Chia Tsai

    2006-04-01

    Full Text Available Background: To detect differences in retinal nerve fiber layer (RNFL measurements inabsolute, advanced and early glaucoma with scanning laser polarimetry (TheNerve Fiber Analyzer GDx, and to assess the usefulness and limitations ofthis technique for longitudinal follow-up of glaucoma patients.Methods: This is a prospective, cross-sectional study. Twenty-one eyes of 21 patientswith absolute glaucoma, twenty-six eyes of 26 patients with advanced glaucomaand twenty-four eyes of 24 patients with early glaucoma were imagedusing scanning laser polarimetry. The twelve standard GDx measurementparameters were compared using ANOVA (analysis of variance and theTukey test.Results: No significant differences were demonstrated for any of the twelve GDxmeasurement parameters between absolute and advanced glaucoma cases.There were significant differences for some GDx parameters, including theGDx number (p < 0.0001 superior ratio (p < 0.0001, inferior ratio (p <0.0001, superior/nasal ratio (p < 0.0001, maximum modulation (p <0.0001, ellipse modulation (p < 0.0001 and inferior average (p = 0.001between early and advanced glaucoma, and, between early and absoluteglaucoma. Significant differences were demonstrated for the superior average(p = 0.01 parameter between early and absolute glaucoma, but notbetween early and advanced glaucoma.Conclusions: For follow-up of glaucoma progression, RNFL measurements using scanninglaser polarimetry are more useful in the early stage than in the advancedstage.

  11. Calibrated complex impedance of CHO cells and E. coli bacteria at GHz frequencies using scanning microwave microscopy

    Science.gov (United States)

    Tuca, Silviu-Sorin; Badino, Giorgio; Gramse, Georg; Brinciotti, Enrico; Kasper, Manuel; Oh, Yoo Jin; Zhu, Rong; Rankl, Christian; Hinterdorfer, Peter; Kienberger, Ferry

    2016-04-01

    The application of scanning microwave microscopy (SMM) to extract calibrated electrical properties of cells and bacteria in air is presented. From the S 11 images, after calibration, complex impedance and admittance images of Chinese hamster ovary cells and E. coli bacteria deposited on a silicon substrate have been obtained. The broadband capabilities of SMM have been used to characterize the bio-samples between 2 GHz and 20 GHz. The resulting calibrated cell and bacteria admittance at 19 GHz were Y cell = 185 μS + j285 μS and Y bacteria = 3 μS + j20 μS, respectively. A combined circuitry-3D finite element method EMPro model has been developed and used to investigate the frequency response of the complex impedance and admittance of the SMM setup. Based on a proposed parallel resistance-capacitance model, the equivalent conductance and parallel capacitance of the cells and bacteria were obtained from the SMM images. The influence of humidity and frequency on the cell conductance was experimentally studied. To compare the cell conductance with bulk water properties, we measured the imaginary part of the bulk water loss with a dielectric probe kit in the same frequency range resulting in a high level of agreement.

  12. Validation of microwave vegetation indices using field experiment data sets

    Science.gov (United States)

    A recent study established the theoretical basis for a new type of index based on passive microwave vegetation indices (MVIs). The approach was then calibrated for use with data from the Advanced Microwave Scanning Radiometer (AMSR-E) on the Aqua satellite under the assumption that there is no signi...

  13. Why different passive microwave algorithms give different soil moisture retrievals

    Science.gov (United States)

    Several algorithms have been used to retrieve surface soil moisture from brightness temperature observations provided by low frequency microwave satellite sensors such as the Advanced Microwave Scanning Radiometer on NASA EOS satellite Aqua (AMSR-E). Most of these algorithms have originated from the...

  14. Significance of Metabolic Super scan in Patients With Locally Advanced Bladder Cancer

    International Nuclear Information System (INIS)

    Non-metastatic metabolic related skeletal changes are predicted in patients with locally advanced bladder cancer. Renal impairment may be a contributing factor in such abnormalities. The aim of this study was to verify the presence of metabolic bone disease in patients with different pathological subgroups of locally advanced bladder cancer and determine its clinical impact, and to correlate these metabolic super scan features with variable laboratory tests of bone bio markers and renal functions. In this study, a total of 350 patients (mean age = 58±8.4 y) with histopathologically proven locally advanced bladder cancer; 238 transitional cell carcinoma (TCC), 100 squamous cell carcinoma (SCC), 7 adenocarcinoma, 2 mucinous adenocarcinoma, 2 undifferentiated carcinoma and 1 leiomyosarcoma. The patients were referred to the Nuclear Medicine Unit, National Cancer Institute, Cairo, Egypt, between July 2006 and December 2009. Whole body bone scan was obtained 3 hours following IV administration of 555-925 MBq Tc-99m MDP. Serum alkaline phosphatase (ALP), calcium and parathormone (PTH) levels were monitored as markers for bone metabolism while serum creatinine was used to monitor kidney function. The exclusion criteria included patients who had liver disease or those taking calcium or vitamin D supplement or any medication that affects bone metabolism. All bone scan results in the study were verified by correlation with other radiological imaging, laboratory data and follow-up for at least 12 months. According to bone scan results, patients were classified into four groups: group A: normal scan (n=223), group B: metabolic super scan features (MSS) (n=70), group C: metastatic bone disease (n=45) and group D: bone scan with indeterminate lesions (n=12). Osteomalacic MSS features were detected in 20 % of the studied patients (locally advanced bladder cancer) compared to 14.5% who had bone metastases. Contrary to metastases which showed high prevalence in TCC (P<0.001), MSS

  15. Predicting moisture content and density distribution of Scots pine by microwave scanning of sawn timber II: Evaluation of models generated on a pixel level

    International Nuclear Information System (INIS)

    The purpose of this study was to use images from a microwave sensor on a pixel level for simultaneous prediction of moisture content and density of wood. The microwave sensor functions as a line-scan camera with a pixel size of 8mm. Boards of Scots pine (Pinus sylvestris), 25 and 50mm thick, were scanned at three different moisture contents. Dry density and moisture content for each pixel were calculated from measurements with a computed tomography scanner. It was possible to create models for prediction of density on a pixel level. Models for prediction of moisture content had to be based on average values over homogeneous regions. Accuracy will be improved if it is possible to make a classification of knots, heartwood, sapwood, etc., and calibrate different models for different types of wood. The limitations of the sensor used are high noise in amplitude measurements and the restriction to one period for phase measurements

  16. Rain Rate Retrieval Algorithm for Conical-Scanning Microwave Imagers Aided by Random Forest, RReliefF, and Multivariate Adaptive Regression Splines (RAMARS)

    OpenAIRE

    Islam, Tanvir; Srivastava, Prashant; Dai, Qiang; Gupta, Manika; Zhuo, Lu

    2015-01-01

    This paper proposes a rain rate retrieval algorithm for conical-scanning microwave imagers (RAMARS), as an alternative to the NASA Goddard profiling (GPROF) algorithm, that does not rely on any a priori information. The fundamental basis of the RAMARS follows the concept of the GPROF algorithm, which means, being consistent with the Tropical Rainfall Measuring Mission (TRMM) precipitation radar rain rate observations, but independent of any auxiliary information. The RAMARS is built upon the ...

  17. Metal-oxide-semiconductor capacitors and Schottky diodes studied with scanning microwave microscopy at 18 GHz

    International Nuclear Information System (INIS)

    We measured the DC and RF impedance characteristics of micrometric metal-oxide-semiconductor (MOS) capacitors and Schottky diodes using scanning microwave microscopy (SMM). The SMM consisting of an atomic force microscopy (AFM) interfaced with a vector network analyser (VNA) was used to measure the reflection S11 coefficient of the metallic MOS and Schottky contact pads at 18 GHz as a function of the tip bias voltage. By controlling the SMM biasing conditions, the AFM tip was used to bias the Schottky contacts between reverse and forward mode. In reverse bias direction, the Schottky contacts showed mostly a change in the imaginary part of the admittance while in forward bias direction the change was mostly in the real part of the admittance. Reference MOS capacitors which are next to the Schottky diodes on the same sample were used to calibrate the SMM S11 data and convert it into capacitance values. Calibrated capacitance between 1–10 fF and 1/C2 spectroscopy curves were acquired on the different Schottky diodes as a function of the DC bias voltage following a linear behavior. Additionally, measurements were done directly with the AFM-tip in contact with the silicon substrate forming a nanoscale Schottky contact. Similar capacitance-voltage curves were obtained but with smaller values (30–300 aF) due to the corresponding smaller AFM-tip diameter. Calibrated capacitance images of both the MOS and Schottky contacts were acquired with nanoscale resolution at different tip-bias voltages

  18. DEVELOPMENT OF ADVANCED DRILL COMPONENTS FOR BHA USING MICROWAVE TECHNOLOGY INCORPORATING CARBIDE, DIAMOND COMPOSITES AND FUNCTIONALLY GRADED MATERIALS

    Energy Technology Data Exchange (ETDEWEB)

    Dinesh Agrawal; Rustum Roy

    2000-11-01

    The main objective of this program was to develop an efficient and economically viable microwave processing technique to process cobalt cemented tungsten carbide with improved properties for drill-bits for advanced drilling operations for oil, gas, geothermal and excavation industries. The program was completed in three years and successfully accomplished all the states goals in the original proposal. In three years of the program, we designed and built several laboratory scale microwave sintering systems for conducting experiments on Tungsten carbide (WC) based composites in controlled atmosphere. The processing conditions were optimized and various properties were measured. The design of the system was then modified to enable it to process large commercial parts of WC/Co and in large quantities. Two high power (3-6 kW) microwave systems of 2.45 GHz were built for multi samples runs in a batch process. Once the process was optimized for best results, the technology was successfully transferred to our industrial partner, Dennis Tool Co. We helped them to built couple of prototype microwave sintering systems for carbide tool manufacturing. It was found that the microwave processed WC/Co tools are not only cost effective but also exhibited much better overall performance than the standard tools. The results of the field tests performed by Dennis Tool Co. showed remarkable advantage and improvement in their overall performance. For example: wear test shows an increase of 20-30%, corrosion test showed much higher resistance to the acid attack, erosion test exhibited about 15% better resistance than standard sinter-HIP parts. This proves the success of microwave technology for WC/Co based drilling tools. While we have successfully transferred the technology to our industrial partner Dennis Tool Co., they have signed an agreement with Valenite, a world leading WC producer of cutting and drilling tools and wear parts, to push aggressively the new microwave technology in

  19. Advanced W-Band Gallium Nitride Monolithic Microwave Integrated Circuits (MMICs) for Cloud Doppler Radar Supporting ACE Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Develop W-band Gallium Nitride (GaN) MMICs to enable the advanced cross-track scanning, dual-frequency Doppler cloud radar concept in support of the...

  20. Development of scanning X-ray microscopes for materials science spectromicroscopy at the Advanced Light Source

    International Nuclear Information System (INIS)

    Third generation synchrotron sources of soft x-rays provide an excellent opportunity to apply established x-ray spectroscopic materials analysis techniques to surface imaging on a sub-micron scale. This paper describes an effort underway at the Advanced Light Source (ALS) to pursue this development using Fresnel zone plate lenses. These are used to produce a sub-micron spot of x-rays for use in scanning microscopy. Several groups have developed microscopes using this technique. A specimen is rastered in the focused x-ray spot and a detector signal is acquired as a function of position to generate an image. Spectroscopic capability is added by holding the small spot on a feature of interest and scanning through the spectrum. The authors are pursuing two spectroscopic techniques: Near Edge X-ray Absorption Spectroscopy (NEXAFS), X-ray Photoelectron Spectroscopy (XPS) which together provide a powerful capability for light element analysis in materials science

  1. Characterizations of microwave plasma CVD grown polycrystalline diamond coatings for advanced technological applications

    Directory of Open Access Journals (Sweden)

    Awadesh Kumar Mallik

    2014-06-01

    Full Text Available Polycrystalline diamond (PCD coatings ranging from few microns to several hundred microns thickness have been grown by 915 MHz microwave plasma reactor with 9000 W power. The coatings were deposited on 100 mm diameter silicon (Si substrate from few hours to several days of continuous runs. PCD coatings were made freestanding by wet chemical etching technique. The deposited PCDs were evaluated by X-ray diffraction (XRD, scanning electron microscopy (SEM, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS for physical characterization and compared with authors’ earlier work. Refractive index of 2.41 was obtained at 633 nm wavelength and a maximum of 6.6 W·cm-1K-1 value for thermal conductivity could be achieved with the grown coatings. The values are well above the existing non-diamond heat spreading substrates, which makes the grown PCDs as candidates for heat spreaders in different technological applications. High refractive index along with translucent nature of the white freestanding PCDs, make them potential candidate for optical windows.

  2. Advanced Treatment of Pesticide-Containing Wastewater Using Fenton Reagent Enhanced by Microwave Electrodeless Ultraviolet.

    Science.gov (United States)

    Cheng, Gong; Lin, Jing; Lu, Jian; Zhao, Xi; Cai, Zhengqing; Fu, Jie

    2015-01-01

    The photo-Fenton reaction is a promising method to treat organic contaminants in water. In this paper, a Fenton reagent enhanced by microwave electrodeless ultraviolet (MWEUV/Fenton) method was proposed for advanced treatment of nonbiodegradable organic substance in pesticide-containing biotreated wastewater. MWEUV lamp was found to be more effective for chemical oxygen demand (COD) removal than commercial mercury lamps in the Fenton process. The pseudo-first order kinetic model can well describe COD removal from pesticide-containing wastewater by MWEUV/Fenton, and the apparent rate constant (k) was 0.0125 min(-1). The optimal conditions for MWEUV/Fenton process were determined as initial pH of 5, Fe(2+) dosage of 0.8 mmol/L, and H2O2 dosage of 100 mmol/L. Under the optimal conditions, the reaction exhibited high mineralization degrees of organics, where COD and dissolved organic carbon (DOC) concentration decreased from 183.2 mg/L to 36.9 mg/L and 43.5 mg/L to 27.8 mg/L, respectively. Three main pesticides in the wastewater, as Dimethoate, Triazophos, and Malathion, were completely removed by the MWEUV/Fenton process within 120 min. The high degree of pesticides decomposition and mineralization was proved by the detected inorganic anions. PMID:26347877

  3. Use of the advanced microwave sounding unit data to improve typhoon prediction

    Institute of Scientific and Technical Information of China (English)

    Guo Deng; Dalin Zhang; Tong Zhu; Angsheng Wang

    2009-01-01

    The effects of incorporating the advanced microwave sounding unit(AMSU-A)data with a modified Zhu-Zhang-Weng vortexbogussing algorithm on typhoon prediction are examined through the use of the PSU/NCAR Mesoscale Model version 5(MM5).The AMSU-A data contain the vertical distribution of the retrieved temperature from satellite brightness temperature, with the geopotential height and wind fields derived through a series of statistical and diagnostic calculations.The advantages of the modified vortexbogussing algorithm include the incorporation of realistic asymmetric typhoon structures,the balanced dynamics with the background field,the easiness to implement and the efficient computations.To test the efficiency of this vortex-bogussing algorithm,the Typhoon Dan event in 1999 is simulated by incorporating the derived AMSU-A fields into the initial conditions of the MM5 modeling system.Results show significant improvements in the track and intensity of the storm, as compared to the simulation without the AMSU-A data.Therefore,this modified vortex-bogussing algorithm can be easily implemented on any typhoon modeling system,which will improve the real-time forecast of tropical cyclones.

  4. Integrated Advanced Microwave Sounding Unit-A (AMSU-A). Performance Verification Report: Antenna Drive Subsystem METSAT AMSU-A2 (PN:1331200-2, SN:108)

    Science.gov (United States)

    Haapala, C.

    1999-01-01

    This is the Performance Verification Report, Antenna Drive Subassembly, Antenna Drive Subsystem, METSAT AMSU-A2 (P/N 1331200-2, SN: 108), for the Integrated Advanced Microwave Sounding Unit-A (AMSU-A).

  5. 高功率微波束的旋摆扫描方法%A method for high power microwave beam scan by spin and swing

    Institute of Scientific and Technical Information of China (English)

    钟哲夫

    2001-01-01

    For high power microwave application, the offset parabolic antennas have advantages of lower side lobes, lower standing wave ratio, high efficiency and avoiding breakdown comparing with the center feed parent. Without any rotary RF joint in the high power microwave transmit system, the scan can be achieved by spinning the reflector around the axe of the feed and swinging the reflector and feed around the focus in the (x,z) plane by using a vacuum flexible elliptical waveguide. By geometric approach, the scan functions are presented. The scan properties are characterized with the maximum elevation angle range at a definite distance. The renations between the scan characteristics and the antenna geometric and spin-swing parameters are given for the antenna design. The spin-swing single offset parabolic antenna has small transmission loss and simpler mechanical scan construction.%用于高功率微波发射的偏置抛物面天线,使其反射面绕馈源轴旋转,反射面与馈源借助真空椭圆软波导进行摆动,从而实现面域扫描。给出这种天线的旋摆扫描关系式,对其扫描性能及其与结构和旋摆参数的关系进行分析,结合物理光学修正,为天线系统的设计提供了理论依据。

  6. Characterization of geolocation accuracy of Suomi NPP Advanced Technology Microwave Sounder measurements

    Science.gov (United States)

    Han, Yang; Weng, Fuzhong; Zou, Xiaolei; Yang, Hu; Scott, Deron

    2016-05-01

    The Advanced Technology Microwave Sounder (ATMS) onboard Suomi National Polar-orbiting Partnership satellite has 22 channels at frequencies ranging from 23 to 183 GHz for probing the atmospheric temperature and moisture under all weather conditions. As part of the ATMS calibration and validation activities, the geolocation accuracy of ATMS data must be well characterized and documented. In this study, the coastline crossing method (CCM) and the land-sea fraction method (LFM) are utilized to characterize and quantify the ATMS geolocation accuracy. The CCM is based on the inflection points of the ATMS window channel measurements across the coastlines, whereas the LFM collocates the ATMS window channel data with high-resolution land-sea mask data sets. Since the ATMS measurements provide five pairs of latitude and longitude data for K, Ka, V, W, and G bands, respectively, the window channels 1, 2, 3, 16, and 17 from each of these five bands are chosen for assessing the overall geolocation accuracy. ATMS geolocation errors estimated from both methods are generally consistent from 40 cases in June 2014. The ATMS along-track (cross-track) errors at nadir are within ±4.2 km (±1.2 km) for K/Ka, ±2.6 km (±2.7 km) for V bands, and ±1.2 km (±0.6 km) at W and G bands, respectively. At the W band, the geolocation errors derived from both algorithms are probably less reliable due to a reduced contrast of brightness temperatures in coastal areas. These estimated ATMS along-track and cross-track geolocation errors are well within the uncertainty requirements for all bands.

  7. Advances on simultaneous desulfurization and denitrification using activated carbon irradiated by microwaves.

    Science.gov (United States)

    Ma, Shuang-Chen; Gao, Li; Ma, Jing-Xiang; Jin, Xin; Yao, Juan-Juan; Zhao, Yi

    2012-06-01

    This paper describes the research background and chemistry of desulfurization and denitrification technology using microwave irradiation. Microwave-induced catalysis combined with activated carbon adsorption and reduction can reduce nitric oxide to nitrogen and sulfur dioxide to sulfur from flue gas effectively. This paper also highlights the main drawbacks of this technology and discusses future development trends. It is reported that the removal of sulfur dioxide and nitric oxide using microwave irradiation has broad prospects for development in the field of air pollution control. PMID:22856293

  8. Assessment of the consistency among global microwave land surface emissivity products

    OpenAIRE

    H. Norouzi; Temimi, M.; Prigent, C.; Turk, J.; Khanbilvardi, R.; Y. Tian; F. A. Furuzawa; Masunaga, H.

    2015-01-01

    The goal of this work is to intercompare four global land surface emissivity products over various land-cover conditions to assess their consistency. The intercompared land emissivity products were generated over a 5-year period (2003–2007) using observations from the Advanced Microwave Scanning Radiometer – Earth Observing System (AMSR-E), the Special Sensor Microwave Imager (SSM/I), the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI), and WindSat. First, ...

  9. Microwave photonics

    CERN Document Server

    Lee, Chi H

    2006-01-01

    Wireless, optical, and electronic networks continue to converge, prompting heavy research into the interface between microwave electronics, ultrafast optics, and photonic technologies. New developments arrive nearly as fast as the photons under investigation, and their commercial impact depends on the ability to stay abreast of new findings, techniques, and technologies. Presenting a broad yet in-depth survey, Microwave Photonics examines the major advances that are affecting new applications in this rapidly expanding field.This book reviews important achievements made in microwave photonics o

  10. Microwave photonics

    CERN Document Server

    Lee, Chi H

    2013-01-01

    Microwave photonics continues to see rapid growth. The integration of optical fiber and wireless networks has become a commercial reality and is becoming increasingly pervasive. Such hybrid technology will lead to many innovative applications, including backhaul solutions for mobile networks and ultrabroadband wireless networks that can provide users with very high bandwidth services. Microwave Photonics, Second Edition systematically introduces important technologies and applications in this emerging field. It also reviews recent advances in micro- and millimeter-wavelength and terahertz-freq

  11. Integrated Advanced Microwave Sounding Unit-A (AMSU-A). Performance Verification Report: AMSU-A1 Antenna Drive Subsystem, PN 1331720-2, S/N 106

    Science.gov (United States)

    Luu, D.

    1999-01-01

    This is the Performance Verification Report, AMSU-A1 Antenna Drive Subsystem, P/N 1331720-2, S/N 106, for the Integrated Advanced Microwave Sounding Unit-A (AMSU-A). The antenna drive subsystem of the METSAT AMSU-A1, S/N 106, P/N 1331720-2, completed acceptance testing per A-ES Test Procedure AE-26002/lD. The test included: Scan Motion and Jitter, Pulse Load Bus Peak Current and Rise Time, Resolver Reading and Position Error, Gain/ Phase Margin, and Operational Gain Margin. The drive motors and electronic circuitry were also tested at the component level. The drive motor test includes: Starting Torque Test, Motor Commutation Test, Resolver Operation/ No-Load Speed Test, and Random Vibration. The electronic circuitry was tested at the Circuit Card Assembly (CCA) level of production; each test exercised all circuit functions. The transistor assembly was tested during the W3 cable assembly (1356941-1) test.

  12. Advanced scanning transmission stereo electron microscopy of structural and functional engineering materials

    International Nuclear Information System (INIS)

    Stereo transmission electron microscopy (TEM) provides a 3D impression of the microstructure in a thin TEM foil. It allows to perform depth and TEM foil thickness measurements and to decide whether a microstructural feature lies inside of a thin foil or on its surface. It allows appreciating the true three-dimensional nature of dislocation configurations. In the present study we first review some basic elements of classical stereo TEM. We then show how the method can be extended by working in the scanning transmission electron microscope (STEM) mode of a modern analytical 200 kV TEM equipped with a field emission gun (FEG TEM) and a high angle annular dark field (HAADF) detector. We combine two micrographs of a stereo pair into one anaglyph. When viewed with special colored glasses the anaglyph provides a direct and realistic 3D impression of the microstructure. Three examples are provided which demonstrate the potential of this extended stereo TEM technique: a single crystal Ni-base superalloy, a 9% Chromium tempered martensite ferritic steel and a NiTi shape memory alloy. We consider the effect of camera length, show how foil thicknesses can be measured, and discuss the depth of focus and surface effects. -- Highlights: ► The advanced STEM/HAADF diffraction contrast is extended to 3D stereo-imaging. ► The advantages of the new technique over stereo-imaging in CTEM are demonstrated. ► The new method allows foil thickness measurements in a broad range of conditions. ► We show that features associated with ion milling surface damage can be beneficial for appreciating 3D features of the microstructure.

  13. Water equivalent of snow retrieved from data of passive microwave scanning with the use of artificial neural networks over the Russian Federation territory

    Directory of Open Access Journals (Sweden)

    A. A. Volchek

    2016-01-01

    Full Text Available Using of the Chang model for calculation of the snow water equivalent on the basis of measurements of the Earth thermo-microwave radiation by means of scanning polarimeters (SMMR, SSM/I, AMSR-E from board of orbital satellites does not allow obtaining the accuracy needed hydrological purposes. Low accuracy of the calculations is caused by both simplified character of the mathematical model, and due to significant influence of the surface characteristics (relief, vegetation and complex structure of snow thickness upon the microwave radiation propagation. This work was aimed at finding a way to increase accuracy of calculations of the snow water equivalent on the Russian Federation territory with its different climate conditions by means of application the neural network approach for processing of results of the passive microwave scanning of the Earth surface. Feed-forward multi-layer artificial neural network was trained by back-propagation algorithm using SSM/I data and results of snow water equivalent in situ measurements obtained at 117 meteorological stations during the period from January 1st, 1988 till December 31st, 1988. Validation was performed using data from the same sources collected during 7 years (1992–1998. Results of performed numerical experiments and obtained values of rootmean-square error (σ = 24.9 мм; r = 0.39±0,01 allow coming to conclusion that the best estimation of water equivalent of a snow cover is provided by artificial neural network using as the input data a set of the SSM/I channels 19.35, 37.0, 85.5 GHz of horizontal and vertical polarizations with meteorological data differentiated by types of the snow survey route.It is shown that low correlation coefficients (< 0.5 as compared with similar studies on small areas is not caused by the chosen mathematical model and its realization but it is due to a strong diversity of climatic conditions and low density of meteorological stations on the land areas

  14. Microwave Assisted Reactions in Organic Chemistry: A Review of Recent Advances

    OpenAIRE

    Jolly Jacob

    2012-01-01

    Revolution in organic compound synthesis has been promoted by microwave assisted organic syntheses (MAOS) by which small molecules are built up into large polymers in a fraction of time. The need for different organic compound libraries for drug discovery, biomaterial development, automated library screening; proteomics etc has supported the emergence of innovative technologies for rapid combinatorial organic synthesis using MAOS synthesis. In previous reviews on this subject the focus of MAO...

  15. A Prototype Hail Detection Algorithm and Hail Climatology Developed with the Advanced Microwave Sounding Unit (AMSU)

    Science.gov (United States)

    Ferraro, Ralph; Beauchamp, James; Cecil, Dan; Heymsfeld, Gerald

    2015-01-01

    In previous studies published in the open literature, a strong relationship between the occurrence of hail and the microwave brightness temperatures (primarily at 37 and 85 GHz) was documented. These studies were performed with the Nimbus-7 SMMR, the TRMM Microwave Imager (TMI) and most recently, the Aqua AMSR-E sensor. This lead to climatologies of hail frequency from TMI and AMSR-E, however, limitations include geographical domain of the TMI sensor (35 S to 35 N) and the overpass time of the Aqua satellite (130 am/pm local time), both of which reduce an accurate mapping of hail events over the global domain and the full diurnal cycle. Nonetheless, these studies presented exciting, new applications for passive microwave sensors. Since 1998, NOAA and EUMETSAT have been operating the AMSU-A/B and the MHS on several operational satellites: NOAA-15 through NOAA-19; MetOp-A and -B. With multiple satellites in operation since 2000, the AMSU/MHS sensors provide near global coverage every 4 hours, thus, offering a much larger time and temporal sampling than TRMM or AMSR-E. With similar observation frequencies near 30 and 85 GHz and additionally three at the 183 GHz water vapor band, the potential to detect strong convection associated with severe storms on a more comprehensive time and space scale exists. In this study, we develop a prototype AMSU-based hail detection algorithm through the use of collocated satellite and surface hail reports over the continental U.S. for a 12-year period (2000-2011). Compared with the surface observations, the algorithm detects approximately 40 percent of hail occurrences. The simple threshold algorithm is then used to generate a hail climatology that is based on all available AMSU observations during 2000-11 that is stratified in several ways, including total hail occurrence by month (March through September), total annual, and over the diurnal cycle. Independent comparisons are made compared to similar data sets derived from other

  16. Tracking Fires in India Using Advanced Along Track Scanning Radiometer (AATSR Data

    Directory of Open Access Journals (Sweden)

    Anke Jentsch

    2010-02-01

    Full Text Available Forest fires pose a threat more serious than illegal felling in developing countries and are a cause of major concern for environmental security. Fires in tropical forests, though not devastating on a large scale as compared to large and infrequent fires in boreal or Mediterranean systems, still cause loss to biodiversity and economic and monetary value. In India, human-induced forest fires increasingly affect legally protected nature conservation areas. An array of satellite sensors that are now available can be deployed to monitor such events on a global and local scale. The present study uses night-time Advanced Along Track Scanning Radiometer (AATSR satellite data from the last nine years to identify high fire-prone zones, fire affected areas in protected zones and the distribution of these incidents in relation to bio-geographic zones. Central India, with its vegetation type that is just right for fire ignition and spread, was observed to be the most severely affected area with maximum fire incidences. The bio-geographic zone comprising this area–such as the Deccan peninsula, which includes provinces like Central Highlands, Eastern Highlands, Central Plateau and Chhota Nagpur–was observed to be the most affected, accounting for approximately 36% of the total fire occurrences during the period 1997–2005. In protected areas, 778 fire incidents were observed within the last eight years. Comparison of (AATSR fire locations with MODIS active fire data for the Western Ghats (mainly of tropical evergreen forests and savannahs and the Eastern Ghats (tropical deciduous showed a spatial agreement of 72% with a minimum distance between the two products of 100 m. This study focuses on regions in India that are vulnerable to forest fires during specific time-frames and appraises the situation with an aim to minimize such incidents, if not completely stop the fire spread and its consequent destruction and loss. Our main objective is to understand

  17. Biases caused by the instrument bandwidth and beam width on simulated brightness temperature measurements from scanning microwave radiometers

    Directory of Open Access Journals (Sweden)

    V. Meunier

    2012-11-01

    Full Text Available More so than the traditional fixed radiometers, the scanning radiometer requires a careful design to ensure high quality measurements. Here the impact of the radiometer characteristics (e.g. antenna beam width, receiver bandwidth and atmospheric propagation (e.g. curvature of the earth and refractivity on the scanning radiometer measurements are presented. A forward radiative transfer model that includes all these effects to represent the instrument measurements is used to estimate the biases as differences between the measurement with and without these characteristics for three commonly used frequency bands: K, V and W-band. The receiver channel bandwidth errors are not so important in K-band and W-band. Thus, the use of a wider bandwidth to improve detection at low signal-to-noise conditions is acceptable. The impact of the antenna beam width is higher than the receiver bandwidth, but, for V-band where they are of similar importance. Using simple regression algorithms, the effects of the bandwidth and beam width biases in liquid water path, integrated water vapor, and temperature are also examined. The largest errors in liquid water path and integrated water vapor are associated with the beam width errors.

  18. Recent Advances in the Design of Electro-Optic Sensors for Minimally Destructive Microwave Field Probing

    Directory of Open Access Journals (Sweden)

    John F. Whitaker

    2011-01-01

    Full Text Available In this paper we review recent design methodologies for fully dielectric electro-optic sensors that have applications in non-destructive evaluation (NDE of devices and materials that radiate, guide, or otherwise may be impacted by microwave fields. In many practical NDE situations, fiber-coupled-sensor configurations are preferred due to their advantages over free-space bulk sensors in terms of optical alignment, spatial resolution, and especially, a low degree of field invasiveness. We propose and review five distinct types of fiber-coupled electro-optic sensor probes. The design guidelines for each probe type and their performances in absolute electric-field measurements are compared and summarized.

  19. The primary design of advanced ground-based atmospheric microwave sounder and retrieval of physical parameters

    International Nuclear Information System (INIS)

    This paper introduces a prototype of ground-based atmospheric microwave sounder that operates in K-band from 22 to 31 GHz and V-band from 51 to 59 GHz. Different from the MP3000A and RPG, the sounder adopts independent dual-band reflectors instead of sharing a dual-band reflector. The direct detect type receiver is applied, which is of smaller size, higher sensitivity, efficient data observing and lower nonlinear error than the widely used superheterodyne receiver. The observing brightness temperatures from this prototype agree well with the simulated brightness temperatures according to the ground-based radiative transfer theory. We use the artificial neural network (ANN) algorithm to retrieve temperature profiles, which has higher spatial resolution especially in the capping inversion when compared with the linear regression algorithm. The temperature retrievals are comparable with the retrievals from RPG and MP3000A retrieval models and have a smaller bias in some certain regions.

  20. Fresnel-region fields and antenna noise-temperature calculations for advanced microwave sounding units

    Science.gov (United States)

    Schmidt, R. F.

    1982-01-01

    A transition from the antenna noise temperature formulation for extended noise sources in the far-field or Fraunhofer-region of an antenna to one of the intermediate near field or Fresnel-region is discussed. The effort is directed toward microwave antenna simulations and high-speed digital computer analysis of radiometric sounding units used to obtain water vapor and temperature profiles of the atmosphere. Fresnel-region fields are compared at various distances from the aperture. The antenna noise temperature contribution of an annular noise source is computed in the Fresnel-region (D squared/16 lambda) for a 13.2 cm diameter offset-paraboloid aperture at 60 GHz. The time-average Poynting vector is used to effect the computation.

  1. Direct observation of electrical properties of grain boundaries in sputter-deposited CdTe using scan-probe microwave reflectivity based capacitance measurements

    Science.gov (United States)

    Tuteja, Mohit; Koirala, Prakash; MacLaren, Scott; Collins, Robert; Rockett, Angus

    2015-10-01

    Polycrystalline CdTe in 12% efficient solar cells has been studied using scanning microwave impedance microscopy (sMIM). The CdS/CdTe junctions were grown on transparent-conducting-oxide-coated soda lime glass using rf sputter deposition. sMIM based capacitance measurements were performed on the exposed surface of CdCl2 treated CdTe adjacent to thermal-evaporation-deposited Cu/Au back contacts. The sMIM instrument was operated at ˜3 GHz, and capacitance measurements were performed as a function of ac and dc voltage biases applied to the tip, with and without sample illumination. Although dc capacitance measurements are affected by sample topography, the differential capacitance measurement was shown to be topography independent. It was found that the grain boundaries exhibit a depleted carrier concentration as compared to the grain bulk. This depletion effect is enhanced under photo-generated carrier separation or under sufficiently large probe tip biases opposite to the majority carrier charge.

  2. The onset of spring melt in first-year ice regions of the Arctic as determined from scanning multichannel microwave radiometer data for 1979 and 1980

    Science.gov (United States)

    Anderson, Mark R.

    1987-11-01

    Sea ice ablation is an important physical process affecting the global climate system. During the Arctic melt season, rapid changes occur in both sea ice surface conditions and the extent of ice. These changes alter the albedo and vary the surface energy budget. Understanding variations in Arctic sea ice is critical for global climate studies. This paper investigates the spring onset of melt in the Arctic seasonal sea ice zone through analysis of melt signatures derived from Nimbus 7 scanning multichannel microwave radiometer data. Satellite-derived melt signatures, determined by 18- and 37-GHz vertical brightness temperatures, are associated with the initial melt of the snow pack on the sea ice surface. Sea ice melt events vary spatially and temporally. Within the arctic basin the melt signature is observed first in the Chukchi Sea and the Kara and Barents seas. As melting progresses, the melt signature moves westward from the Chukchi Sea and eastward from the Kara and Barents seas to the Laptev Sea region. The initial location of the melt signal also varies with year. In 1979 the melt signature occurs first in the Chukchi Sea; and in 1980 in the Kara Sea. The date for the initial melt varies between 1979 and 1980 by an average of 7-10 days with a maximum of 25 days in the Chukchi Sea region. Monitoring the occurrence of melt signatures can be used as an indicator of climate variability in the Arctic's seasonal sea ice zones.

  3. Microwave Ablation in Combination with Chemotherapy for the Treatment of Advanced Non-Small Cell Lung Cancer

    International Nuclear Information System (INIS)

    PurposeTo verify whether microwave ablation (MWA) used as a local control treatment had an improved outcome regarding advanced non-small cell lung cancer (NSCLC) when combined with chemotherapy.MethodsThirty-nine patients with histologically verified advanced NSCLC and at least one measurable site other than the ablative sites were enrolled. Primary tumors underwent MWA followed by platinum-based doublet chemotherapy. Modified response evaluation criteria in solid tumors (mRECIST) and RECIST were used to evaluate therapeutic response. Complications were assessed using the National Cancer Institute Common Toxicity Criteria (version 3.0).ResultsMWA was administered to 39 tumors in 39 patients. The mean and median diameters of the primary tumor were 3.84 cm and 3.30 cm, respectively, with a range of 1.00–9.00 cm. Thirty-three (84.6 %) patients achieved a partial response. No correlation was found between MWA efficacy and clinicopathologic characteristics. For chemotherapy, 11 patients (28.2 %) achieved a partial response, 18 (46.2 %) showed stable disease, and 10 (25.6 %) had progressive disease. The overall objective response rate and disease control rate were 28.2 and 74.4 %, respectively. The median progression-free survival time was 8.7 months (95 % CI 5.5–11.9). The median overall survival time was 21.3 months (95 % CI 17.0–25.4). Complications were observed in 22 (56.4 %) patients, and grade 3 adverse events were observed in 3 (7.9 %) patients.ConclusionsPatients with advanced NSCLC could benefit from MWA in combination with chemotherapy. Complications associated with MWA were common but tolerable

  4. A new bend magnet beam line for scanning transmission x-ray microscopy at the Advanced Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Warwick, Tony; Ade, Harald; Kilcoyne, A.L. David; Kritscher, Michael; Tylisczcak, Tolek; Fakra, Sirine; Hitchcock, Adam P.; Hitchcock, Peter; Padmore, Howard A.

    2001-12-12

    The high brightness of the bend magnets at the Advanced Light Source has been exploited to illuminate a Scanning Transmission X-ray Microscope (STXM). This is the first diffraction-limited scanning x-ray microscope to operate with useful count rate on a synchrotron bend magnet source. A simple, dedicated beam line has been built covering the range of photon energy from 250 eV to 600 eV. Ease of use and operational availability are radically improved compared to previous installations using undulator beams. This facility provides radiation for C 1s, N 1s and O 1s near edge x-ray absorption spectro-microscopy with a spectral resolution up to about 1:5000 and with STXM count rates in excess of 1 MHz.

  5. Advanced scanning transmission stereo electron microscopy of structural and functional engineering materials

    Czech Academy of Sciences Publication Activity Database

    Agudo Jácome, L.; Eggeler, G.; Dlouhý, Antonín

    2012-01-01

    Roč. 122, NOV (2012), s. 48-59. ISSN 0304-3991 R&D Projects: GA ČR GA202/09/2073 Institutional research plan: CEZ:AV0Z20410507 Keywords : stereoscopy * scanning transmission electron microscopy * single crystal Ni-base superalloys * Dislocation substructures * Foil thickness measurement Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.470, year: 2012

  6. Oversampling advances in millimeter-wave scan imaging using inexpensive neon indicator lamp detectors

    Science.gov (United States)

    Levanon, Assaf; Kopeika, Natan S.; Yitzhaky, Yitzhak; Abramovich, Amir; Rozban, Daniel; Joseph, Hezi; Aharon, Avihai; Belenky, Alex; Gefen, Michael; Yadid-Pecht, Orly

    2013-06-01

    In recent years, much effort has been invested to develop room temperature inexpensive, but sensitive, millimeter wave (MMW) and terahertz (THz) detectors that can be used as pixels in focal plane arrays, which is important for real-time imaging. A new 18×2 neon indicator lamp MMW/THz scanner was developed. The components of the camera include horizontally shifted two-column glow discharge detectors in a scanning array. The detectors, costing about 50 cents each, are wired to a preprocessing card, a VLSI board, and a motor for scanner movement. A description of the VLSI Verilog programmable hardware of the new scanner, the physical architecture, the software user interface, and imaging results at 97 GHz are presented. At this stage, the emphasis is focused on the lamp exposure time and spatial resolution when the scanning is performed horizontally. In the future it is planned to expose all pixels simultaneously for real-time imaging. New software capabilities allow the application of digital image enhancement algorithms. Fast scanning permits obtaining images in 1 to 5 s. Oversampling yields a sharper edge response and a higher signal-to-noise ratio.

  7. 微波扫描法检测聚乙烯管道热熔接头缺陷初探%Microwave Scanning Inspection of Defects in Thermo-fusion Joints of Polyethylene Piping

    Institute of Scientific and Technical Information of China (English)

    祝新伟; 潘金平; 谭连江; 徐祥明; 沈美华; 李勇

    2013-01-01

    以聚乙烯管道热熔接头为检测对象,使用微波扫描的方法检测热熔接头中不同类型的缺陷.首先对无缺陷的热熔接头进行微波扫描检测,得到的扫描图像作为参考图像.然后对含有裂纹、冷焊等不同缺陷的聚乙烯管道热熔接头进行微波扫描检测,得到具有不同特征的扫描图像.对这些扫描图像进行分析可以判别缺陷的类型.最后,利用拉伸力学测试的结果,初步验证了微波扫描方法对聚乙烯管道热熔接头缺陷检测的有效性.%The method of microwave scanning was employed to detect different types of defects existing in the thermo - fusion joints of polyethylene ( PE) piping. Firstly the thermo - fusion joints without defects were inspected by microwave scanning,and the scanning images obtained were taken as the references. Then the thermo -fusion joints containing different defects including cracks,cold weld,etc. ,were inspected and the resultant scanning images corresponding to different defects were obtained. The types of the defects can be distinguished by analyzing the scanning images. At last, tensile tests for the thermo - fusion joints were performed to confirm the effectiveness of microwave scanning in detecting the defects in the thermo - fusion joints of PE piping.

  8. Microwave hemorrhagic stroke detector

    Energy Technology Data Exchange (ETDEWEB)

    Haddad, Waleed S. (Dublin, CA); Trebes, James E. (Livermore, CA)

    2007-06-05

    The microwave hemorrhagic stroke detector includes a low power pulsed microwave transmitter with a broad-band antenna for producing a directional beam of microwaves, an index of refraction matching cap placed over the patients head, and an array of broad-band microwave receivers with collection antennae. The system of microwave transmitter and receivers are scanned around, and can also be positioned up and down the axis of the patients head. The microwave hemorrhagic stroke detector is a completely non-invasive device designed to detect and localize blood pooling and clots or to measure blood flow within the head or body. The device is based on low power pulsed microwave technology combined with specialized antennas and tomographic methods. The system can be used for rapid, non-invasive detection of blood pooling such as occurs with hemorrhagic stoke in human or animal patients as well as for the detection of hemorrhage within a patient's body.

  9. Microwave hemorrhagic stroke detector

    Energy Technology Data Exchange (ETDEWEB)

    Haddad, Waleed S. (Dublin, CA); Trebes, James E. (Livermore, CA)

    2002-01-01

    The microwave hemorrhagic stroke detector includes a low power pulsed microwave transmitter with a broad-band antenna for producing a directional beam of microwaves, an index of refraction matching cap placed over the patients head, and an array of broad-band microwave receivers with collection antennae. The system of microwave transmitter and receivers are scanned around, and can also be positioned up and down the axis of the patients head. The microwave hemorrhagic stroke detector is a completely non-invasive device designed to detect and localize blood pooling and clots or to measure blood flow within the head or body. The device is based on low power pulsed microwave technology combined with specialized antennas and tomographic methods. The system can be used for rapid, non-invasive detection of blood pooling such as occurs with hemorrhagic stroke in human or animal patients as well as for the detection of hemorrhage within a patient's body.

  10. B - SCAN ULTRASONOGRAPHY BEFORE SURGERY I N EYES WITH ADVANCED CATARACTS: A USEFUL PROGNOSTIC TOOL

    Directory of Open Access Journals (Sweden)

    Jatin

    2015-05-01

    Full Text Available BACKGROUND : Ocular ultrasonography is an important tool for evaluating the posterior segment in eyes with opaque media . In cases with dense cataract , where posterior segment evaluation by ophthalmoscopy is not possible , B - scan ultrasonography before surgery can help in surgical planning and guiding the expectations of patients . PURPOSE : To determine the relevance and prevalence of posterior segment abnormalities in patients with dense ca taracts prior to surgery by ultrasonography . DESIGN : Prospective diagnostic study . METHODS : Diagnostic B - scan ultrasound was performed on 158 eyes of 132 patients with dense cataract precluding visualization of fundus on ophthalmoscopy from January 2013 to December 2013 . Patients were divided in two groups , traumatic ( 22 and non - traumatic ( 136 . Patients in the age range of 1 to 79 years of both sexes were included . Detailed history and some basic eye examination techniques , like slit lamp and tonometry we re done . Patients having already posterior segment lesions and those who had previous history of ocular surgery were excluded from the study . RESULTS : 26 ( 16 . 4% patients , out of total 158 patients , had posterior segment lesions . Among traumatic group of 22 patients , 15 ( 68 . 1% had positive posterior segment lesions , while only 11 ( 8% patients in the non - traumatic group of 136 patients had positive posterior segment lesions . Out of the 26 positive cases , retinal detachment was found in 8 ( 5% patients , 7 ( 4 . 4% had posterior vitreous detachment , 7 ( 4 . 4% had vitreous hemorrhage , 2 ( 1 . 26% had retinal detachment with vitreous hemorrhage , 1 ( 0 . 63% had asteroid hyalosis , 1 ( 0 . 63% had intra - ocular foreign body . CONCLUSION : We concluded that B - scan ultrasound has sign ificant importance in the preoperative evaluation of patients with dense cataracts to detect pathologies that may influence the surgical strategy and the postoperative visual prognosis .

  11. Introduction of a Double-band, Fan-beam, Conically Scanning Space-borne Microwave Scatterometer System Design%双波段扇形波束圆锥扫描星载微波散射计系统设计

    Institute of Scientific and Technical Information of China (English)

    刘丽霞; 金阿鑫; 王旭燕; 吕庆立; 段崇棣; 陈文新

    2014-01-01

    星载微波散射计是目前唯一能够同时全天候、全天时、高精度、高分辨率和短周期测量海洋表面风场矢量的有源微波遥感器,这一能力已在美国Seasat-1[1]、欧空局ERS-1/2[1]、日本ADEOS-1/2[1]、中国HY-2等卫星装载的微波散射计上得到了充分的证明。双波段、扇形波束圆锥扫描星载微波散射计是一种具有国际先进水平的星载微波散射计,具有测风范围大、测量精度高的优点。文章简要分析了该微波散射计的工作原理、总体方案设计、关键技术、及初步性能评估等。%Space-borne microwave scatterometer is a unique microwave remote sensor which can provide all weather, all time, and short-period measurement with high precision and high spatial resolution for the ocean surface wind field. Double-band fan-beam conically scanning space-borne microwave scatterometer is an advanced space-borne microwave scatterome-ter, which can be applied in the measurement of large-scale and accurate wind field. This paper describes the principle of operation, system design, core technology, and performance estimation based on the simulation platform for this system.

  12. Advanced electric-field scanning probe lithography on molecular resist using active cantilever

    Science.gov (United States)

    Kaestner, Marcus; Aydogan, Cemal; Ivanov, Tzvetan; Ahmad, Ahmad; Angelov, Tihomir; Reum, Alexander; Ishchuk, Valentyn; Krivoshapkina, Yana; Hofer, Manuel; Lenk, Steve; Atanasov, Ivaylo; Holz, Mathias; Rangelow, Ivo W.

    2015-07-01

    The routine "on demand" fabrication of features smaller than 10 nm opens up new possibilities for the realization of many devices. Driven by the thermally actuated piezoresistive cantilever technology, we have developed a prototype of a scanning probe lithography (SPL) platform which is able to image, inspect, align, and pattern features down to the single digit nanoregime. Here, we present examples of practical applications of the previously published electric-field based current-controlled scanning probe lithography. In particular, individual patterning tests are carried out on calixarene by using our developed table-top SPL system. We have demonstrated the application of a step-and-repeat SPL method including optical as well as atomic force microscopy-based navigation and alignment. The closed-loop lithography scheme was applied to sequentially write positive and negative tone features. Due to the integrated unique combination of read-write cycling, each single feature is aligned separately with the highest precision and inspected after patterning. This routine was applied to create a pattern step by step. Finally, we have demonstrated the patterning over larger areas, over existing topography, and the practical applicability of the SPL processes for lithography down to 13-nm pitch patterns. To enhance the throughput capability variable beam diameter electric field, current-controlled SPL is briefly discussed.

  13. Integrated Advanced Microwave Sounding Unit-A (AMSU-A). Performance Verification Report: METSAT Phase Locked Oscillator Assembly, P/N 1348360-1, S/N's F09

    Science.gov (United States)

    Pines, D.

    1999-01-01

    This is the Performance Verification Report, METSAT (Meteorological Satellites) Phase Locked Oscillator Assembly, P/N 1348360-1, S/N F09 and F10, for the Integrated Advanced Microwave Sounding Unit-A (AMSU-A).

  14. Repeat CT-scan assessment of lymph node motion in locally advanced cervical cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Bondar, Luiza; Velema, Laura; Mens, Jan Willem; Heijmen, Ben; Hoogeman, Mischa [Erasmus Medical Center Cancer Institute, Department of Radiation Oncology, 3008 AE, Rotterdam (Netherlands); Zwijnenburg, Ellen [Radboud University Medical Center, Department of Radiation Oncology, Nijmegen (Netherlands)

    2014-12-15

    In cervical cancer patients the nodal clinical target volume (CTV, defined using the major pelvic blood vessels and enlarged lymph nodes) is assumed to move synchronously with the bony anatomy. The aim of this study was to verify this assumption by investigating the motion of the major pelvic blood vessels and enlarged lymph nodes visible in CT scans. For 13 patients treated in prone position, four variable bladder-filling CT scans per patient, acquired at planning and after 40 Gy, were selected from an available dataset of 9-10 CT scans. The bladder, rectum, and the nodal-vessels structure containing the iliac vessels and all visible enlarged nodes were delineated in each selected CT scan. Two online patient setup correction protocols were simulated. The first corrected bony anatomy translations and the second corrected translations and rotations. The efficacy of each correction was calculated as the overlap between the nodal-vessels structure in the reference and repeat CT scans. The motion magnitude between delineated structures was quantified using nonrigid registration. Translational corrections resulted in an average overlap of 58 ± 13% and in a range of motion between 9.9 and 27.3 mm. Translational and rotational corrections significantly improved the overlap (64 ± 13%, p value = 0.007) and moderately reduced the range of motion to 7.6-23.8 mm (p value = 0.03). Bladder filling changes significantly correlated with the nodal-vessels motion (p < 0.001). The motion of the nodal-vessels was large, nonrigid, patient-specific, and only moderately synchronous with the bony anatomy. This study highlights the need for caution when reducing the CTV-to-PTV (PTV planning target volume) margin of the nodal CTV for highly conformal radiation techniques. (orig.) [German] Bei Zervixkarzinompatientinnen wird davon ausgegangen, dass das nodale klinische Zielvolumen (CTV, definiert anhand der grossen Blutgefaesse des Beckens und vergroesserter Lymphknoten) sich synchron mit

  15. Pre-Launch Characterization of the Advanced Technology Microwave Sounder (ATMS) on the Joint Polar Satellite System-1 Satellite (JPSS-1)

    Science.gov (United States)

    Kim, Edward; Leslie, Vince; Lyu, Joseph; Smith, Craig; McCormick, Lisa; Anderson, Kent

    2016-04-01

    The Advanced Technology Microwave Sounder (ATMS) is the newest generation of microwave sounder in the international fleet of polar-orbiting weather satellites, replacing the Advanced Microwave Sounding Unit (AMSU) which first entered service in 1998. The first ATMS was launched aboard the Suomi NPP (S-NPP) satellite in late 2011. The second ATMS is manifested on the Joint Polar Satellite System-1 Satellite (JPSS-1). ATMS provides 22 channels of temperature and humidity sounding observations over a frequency range from 23 to 183 GHz. These microwave soundings provide the highest impact data ingested by operational Numerical Weather Prediction (NWP) models, and are the most critical of the polar-orbiting satellite observations, particularly because microwave sensing can penetrate clouds. This paper will present performance characterizations from pre-launch calibration measurements of the JPSS-1 ATMS just completed in December, 2015. The measurements were conducted in a thermal vacuum chamber with blackbody targets simulating cold space, ambient, and a variable Earth scene. They represent the best opportunity for calibration characterization of the instrument since the environment can be carefully controlled. We will present characterizations of the sensitivity (NEDT), accuracy, nonlinearity, noise spectral characteristics, gain stability, repeatability, and inter-channel correlation. An estimate of expected "striping" will be presented, and a discussion of reflector emissivity effects will also be provided. Comparisons will be made with the S-NPP flight unit. Finally, we will describe planned on-orbit characterizations - such as pitch and roll maneuvers - that will further improve both the measurement quality and the understanding of various error contributions.

  16. NATO Advanced Study Institute on Scanning Probe Microscopy : Characterization, Nanofabrication and Device Application of Functional Materials

    CERN Document Server

    Vilarinho, Paula Maria; Kingon, Angus; Scanning Probe Microscopy : Characterization, Nanofabrication and Device Application of Functional Materials

    2005-01-01

    As the characteristic dimensions of electronic devices continue to shrink, the ability to characterize their electronic properties at the nanometer scale has come to be of outstanding importance. In this sense, Scanning Probe Microscopy (SPM) is becoming an indispensable tool, playing a key role in nanoscience and nanotechnology. SPM is opening new opportunities to measure semiconductor electronic properties with unprecedented spatial resolution. SPM is being successfully applied for nanoscale characterization of ferroelectric thin films. In the area of functional molecular materials it is being used as a probe to contact molecular structures in order to characterize their electrical properties, as a manipulator to assemble nanoparticles and nanotubes into simple devices, and as a tool to pattern molecular nanostructures. This book provides in-depth information on new and emerging applications of SPM to the field of materials science, namely in the areas of characterisation, device application and nanofabrica...

  17. Recent advances and potential applications of modulated differential scanning calorimetry (mDSC) in drug development.

    Science.gov (United States)

    Knopp, Matthias Manne; Löbmann, Korbinian; Elder, David P; Rades, Thomas; Holm, René

    2016-05-25

    Differential scanning calorimetry (DSC) is frequently the thermal analysis technique of choice within preformulation and formulation sciences because of its ability to provide detailed information about both the physical and energetic properties of a substance and/or formulation. However, conventional DSC has shortcomings with respect to weak transitions and overlapping events, which could be solved by the use of the more sophisticated modulated DSC (mDSC). mDSC has multiple potential applications within the pharmaceutical field and the present review provides an up-to-date overview of these applications. It is aimed to serve as a broad introduction to newcomers, and also as a valuable reference for those already practising in the field. Complex mDSC was introduced more than two decades ago and has been an important tool for the quantification of amorphous materials and development of freeze-dried formulations. However, as discussed in the present review, a number of other potential applications could also be relevant for the pharmaceutical scientist. PMID:26721421

  18. Justifiability of amniocentesis on the basis of positive findings of triple test, ultrasound scan and advanced maternal age

    Directory of Open Access Journals (Sweden)

    Dragoslav Bukvic

    2011-05-01

    Full Text Available Objective. To assess the effectiveness of antenatal screening for chromosomal abnormalities based on maternal age (≥35 years, positive ultrasound findings or a positive triple test. Materials and methods. Retrospective six-year study. The pregnant women routinely underwent established clinical and laboratory practice at the Department of Medical Genetics between 1997 and 2003. The women’s case notes were examined to identify indications for karyotyping, gestation period and the outcome of karyotyping and pregnancy. Results. Invasive antenatal tests were performed on 1440 cases, 1168 (81.11% age 35(a, 72 (5.00% positive triple test (b, 24 (1.67% positive ultrasound scanning (c and 176 (12.2% other (psychological, personal reasons, etc (d. The overall positive predictive value was 1.67% (1.6%(a, 1.4% (b, 12.5% (c, 0.0% (d. The constructed model of logistic regression gave an odds-ratio of 8.647 for the “positive ultrasound result vs. maternal age ≥35” indication, while the odds-ratio for the triple test vs. maternal age ≥35 was 0.854. Conclusions. Amniocentesis and cytogenetic analysis of foetal karyotype should be presented as a diagnostic possibility to all women over 35 years. The application of biochemical markers was far from the expected results. If we compare results for indication positive ultrasound scanning vs. maternal age, an oddsratio of ~9 was obtained. These results demonstrate that the likelihood of obtaining positive results (i.e. the presence of chromosome alterations from an amniocentesis having this indication is almost 9 times higher than from having an amniocentesis performed solely for advanced maternal age.

  19. Development of a Nanostructual Microwave Probe Based on GaAs

    CERN Document Server

    Ju, Y; Soyama, H

    2008-01-01

    With the development of nanotechnology, the measurement of electrical properties in local area of materials and devices has become a great need. Although a lot kind of scanning probe microscope have been developed for satisfying the requirement of nanotechnology, a microscope technique which can determine electrical properties in local area of materials and devices is not yet developed. Recently, microwave microscope has been an interest to many researchers, due to its potential in the evaluation of electrical properties of materials and devices. The advance of microwave is that the response of materials is directly relative to the electromagnetic properties of materials. However, because of the problem of the structure of probes, nanometer-scale resolution has not been successful. To achieve the goal, a new structure microwave probe is required. In this paper, we report a nanostructural microwave probe. To restrain the attenuation of microwave in the probe, GaAs was used as the substrate of the probe. To obt...

  20. A High-altitude, Advanced-technology Scanning Laser Altimeter for the Elevation for the Nation Program

    Science.gov (United States)

    Harding, D. J.

    2007-12-01

    In January of this year the National Research Council's Committee on Floodplain Mapping Technologies recommended to Congress that an Elevation for the Nation program be initiated to enable modernization of the nation's floodplain maps and to support the many other nationwide programs reliant on high-accuracy elevation data. Their recommendation is to acquire a national, high-resolution, seamless, consistent, public-domain, elevation data set created using airborne laser swath mapping (ALSM). Although existing commercial ALSM assets can acquire elevation data of sufficient accuracy, achieving nationwide consistency in a cost-effective manner will be a challenge employing multiple low-flying commercial systems conducting local to regional mapping. This will be particularly true in vegetated terrain where reproducible measurements of ground topography and vegetation structure are required for change-detection purposes. An alternative approach using an advanced technology, wide-swath, high-altitude laser altimeter is described here, based on the Swath Imaging Multi-polarization Photon-counting Lidar (SIMPL) under development via funding from NASA's Instrument Incubator Program. The approach envisions a commercial, federal agency and state partnership, with the USGS providing program coordination, NASA implementing the advanced technology instrumentation, the commercial sector conducting data collection and processing and states defining map product requirements meeting their specific needs. An Instrument Synthesis and Analysis (ISAL) study conducted at Goddard Space Flight Center evaluated an instrument compliment deployed on a long-range Gulfstream G550 platform operating at 12 km altitude. The English Electric Canberra is an alternative platform also under consideration. Instrumentation includes a scanning, multi-beam laser altimeter that maps a 10 km wide swath, IMU and Star Trackers for attitude determination, JPL's Global Differential GPS implementation for

  1. Microwave melting device

    International Nuclear Information System (INIS)

    Low level radioactive wastes (concrete pieces) or materials to be melted such as burnt ashes of wastes are charged into a melting furnace. Then, gyrotron of a microwave generator is oscillated, and generated microwaves of a large power are introduced to a melting furnace by a waveguide. The microwaves are irradiated from an irradiator to a beam converging-type reflecting mirror antenna disposed opposite to the irradiator. Then, an antenna driving portion is operated to rotate and move the antenna in parallel. With such procedures, the microwaves of a large power are converged acutely in a beam-like manner to a predetermined range in the melting furnace, and the converged beams of the microwaves are scanned. This can generate heat from the inner side of the materials to be melted charged to the melting furnace by the induction loss and they are melted. (I.N.)

  2. Planned FDG PET-CT Scan in Follow-Up Detects Disease Progression in Patients With Locally Advanced NSCLC Receiving Curative Chemoradiotherapy Earlier Than Standard CT

    DEFF Research Database (Denmark)

    Pan, Yi; Brink, Carsten; Schytte, Tine;

    2015-01-01

    discriminating postradiotherapy changes from tumor relapse. The aim of this study was to evaluate the clinical value of PET-CT scan in the follow-up for patients with locally advanced (LA) NSCLC receiving concomitant chemoradiotherapy (CCRT).Between 2009 and 2013, eligible patients with stages IIB-IIIB NSCLC...... were enrolled in the clinical trial NARLAL and treated in Odense University Hospital (OUH). All patients had a PET-CT scan scheduled 9 months (PET-CT9) after the start of the radiation treatment in addition to standard follow-up (group A). Patients who presented with same clinical stage of NSCLC and...... that patients in group A had higher risk of relapse than in group B.Additional FDG PET-CT scan at 9 months in surveillance increases probability of early detection of disease progression in advanced NSCLC patients treated with curatively intended CCRT....

  3. Microwave engineering

    CERN Document Server

    Pozar, David M

    2012-01-01

    The 4th edition of this classic text provides a thorough coverage of RF and microwave engineering concepts, starting from fundamental principles of electrical engineering, with applications to microwave circuits and devices of practical importance.  Coverage includes microwave network analysis, impedance matching, directional couplers and hybrids, microwave filters, ferrite devices, noise, nonlinear effects, and the design of microwave oscillators, amplifiers, and mixers. Material on microwave and RF systems includes wireless communications, radar, radiometry, and radiation hazards. A large

  4. Integrated Advanced Microwave Sounding Unit-A (AMSU-A). Performance Verification Report: Initial Comprehensive Performance Test Report, P/N 1331200-2-IT, S/N 105/A2

    Science.gov (United States)

    Platt, R.

    1999-01-01

    This is the Performance Verification Report, Initial Comprehensive Performance Test Report, P/N 1331200-2-IT, S/N 105/A2, for the Integrated Advanced Microwave Sounding Unit-A (AMSU-A). The specification establishes the requirements for the Comprehensive Performance Test (CPT) and Limited Performance Test (LPT) of the Advanced Microwave Sounding, Unit-A2 (AMSU-A2), referred to herein as the unit. The unit is defined on Drawing 1331200. 1.2 Test procedure sequence. The sequence in which the several phases of this test procedure shall take place is shown in Figure 1, but the sequence can be in any order.

  5. Source analysis of spaceborne microwave radiometer interference over land

    Institute of Scientific and Technical Information of China (English)

    Li GUAN; Sibo ZHANG

    2016-01-01

    Satellite microwave thermal emissions mixed with signals from active sensors are referred to as radiofrequency interference (RFI).Based on Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E) observations from June 1 to 16,2011,RFI over Europe was identified and analyzed using the modified principal component analysis algorithm in this paper.The X band AMSR-E measurements in England and Italy are mostly affected by the stable,persistent,active microwave transmitters on the surface,while the RFI source of other European countries is the interference of the reflected geostationary TV satellite downlink signals to the measurements of spaceborne microwave radiometers.The locations and intensities of the RFI induced by the geostationary TV and communication satellites changed with time within the observed period.The observations of spacebome microwave radiometers in ascending portions of orbits are usually interfered with over European land,while no RFI was detected in descending passes.The RFI locations and intensities from the reflection of downlink radiation are highly dependent upon the relative geometry between the geostationary satellite and the measuring passive sensor.Only these fields of view of a spacebome instrument whose scan azimuths are close to the azimuth relative to the geostationary satellite are likely to be affected by RFI.

  6. Source analysis of spaceborne microwave radiometer interference over land

    Science.gov (United States)

    Guan, Li; Zhang, Sibo

    2016-03-01

    Satellite microwave thermal emissions mixed with signals from active sensors are referred to as radiofrequency interference (RFI). Based on Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E) observations from June 1 to 16, 2011, RFI over Europe was identified and analyzed using the modified principal component analysis algorithm in this paper. The X band AMSR-E measurements in England and Italy are mostly affected by the stable, persistent, active microwave transmitters on the surface, while the RFI source of other European countries is the interference of the reflected geostationary TV satellite downlink signals to the measurements of spaceborne microwave radiometers. The locations and intensities of the RFI induced by the geostationary TV and communication satellites changed with time within the observed period. The observations of spaceborne microwave radiometers in ascending portions of orbits are usually interfered with over European land, while no RFI was detected in descending passes. The RFI locations and intensities from the reflection of downlink radiation are highly dependent upon the relative geometry between the geostationary satellite and the measuring passive sensor. Only these fields of view of a spaceborne instrument whose scan azimuths are close to the azimuth relative to the geostationary satellite are likely to be affected by RFI.

  7. Microwave imaging

    CERN Document Server

    Pastorino, Matteo

    2010-01-01

    An introduction to the most relevant theoretical and algorithmic aspects of modern microwave imaging approaches Microwave imaging-a technique used in sensing a given scene by means of interrogating microwaves-has recently proven its usefulness in providing excellent diagnostic capabilities in several areas, including civil and industrial engineering, nondestructive testing and evaluation, geophysical prospecting, and biomedical engineering. Microwave Imaging offers comprehensive descriptions of the most important techniques so far proposed for short-range microwave imaging-in

  8. Final Results of the Telaprevir Access Program: FibroScan Values Predict Safety and Efficacy in Hepatitis C Patients with Advanced Fibrosis or Cirrhosis

    OpenAIRE

    Lepida, Antonia; Colombo, Massimo; Fernandez, Inmaculada; Abdurakhmanov, Djamal; Abrao Ferreira, Paulo; Strasser, Simone I; Urbanek, Petr; Mangia, Alessandra; Calleja, José L.; Iraqi, Wafae; DeMasi, Ralph; Lonjon-Domanec, Isabelle; Moreno, Christophe; Wedemeyer, Heiner

    2015-01-01

    Background Liver stiffness determined by transient elastography is correlated with hepatic fibrosis stage and has high accuracy for detecting severe fibrosis and cirrhosis in chronic hepatitis C patients. We evaluated the clinical value of baseline FibroScan values for the prediction of safety and efficacy of telaprevir-based therapy in patients with advanced fibrosis and cirrhosis in the telaprevir Early Access Program HEP3002. Methods 1,772 patients with HCV-1 and bridging fibrosis or cirrh...

  9. Integrated Advanced Microwave Sounding Unit-A (AMSU-A). Performance Verification Reports: Final Comprehensive Performance Test Report, P/N: 1356006-1, S.N: 202/A2

    Science.gov (United States)

    Platt, R.

    1998-01-01

    This is the Performance Verification Report. the process specification establishes the requirements for the comprehensive performance test (CPT) and limited performance test (LPT) of the earth observing system advanced microwave sounding unit-A2 (EOS/AMSU-A2), referred to as the unit. The unit is defined on drawing 1356006.

  10. Innovative Concepts in Microwave Photonics

    OpenAIRE

    Capmany Francoy, José; Sales Maicas, Salvador; Gasulla Mestre, Ivana; Mora Almerich, José; Lloret Soler, Juan Antonio; Sancho Durá, Juan

    2012-01-01

    This paper reports the work carried by ITEAM researchers on novel concepts in the field of Microwave Photonics (MWP). It includes activities related to the general modelling of MWP systems, the use of novel multicore fibers and recent advances in the emergent and hot topic of integrated microwave photonics. Capmany Francoy, J.; Sales Maicas, S.; Gasulla Mestre, I.; Mora Almerich, J.; Lloret Soler, JA.; Sancho Durá, J. (2012). Innovative Concepts in Microwave Photonics. Waves...

  11. Final Results of the Telaprevir Access Program: FibroScan Values Predict Safety and Efficacy in Hepatitis C Patients with Advanced Fibrosis or Cirrhosis.

    Directory of Open Access Journals (Sweden)

    Antonia Lepida

    Full Text Available Liver stiffness determined by transient elastography is correlated with hepatic fibrosis stage and has high accuracy for detecting severe fibrosis and cirrhosis in chronic hepatitis C patients. We evaluated the clinical value of baseline FibroScan values for the prediction of safety and efficacy of telaprevir-based therapy in patients with advanced fibrosis and cirrhosis in the telaprevir Early Access Program HEP3002.1,772 patients with HCV-1 and bridging fibrosis or cirrhosis were treated with telaprevir plus pegylated interferon-α and ribavirin (PR for 12 weeks followed by PR alone, the total treatment duration depending on virological response and previous response type. Liver fibrosis stage was determined either by liver biopsy or by non-invasive markers. 1,282 patients (72% had disease stage assessed by FibroScan; among those 46% were classified as Metavir F3 at baseline and 54% as F4.Overall, 1,139 patients (64% achieved a sustained virological response (SVR by intention-to-treat analysis. Baseline FibroScan values were tested for association with SVR and the occurrence of adverse events. By univariate analysis, higher baseline FibroScan values were predictive of lower sustained virological response rates and treatment-related anemia. By multivariate analysis, FibroScan was no longer statistically significant as an independent predictor, but higher FibroScan values were correlated with the occurrence of infections and serious adverse events.FibroScan has a limited utility as a predictor of safety and efficacy in patients treated with telaprevir-based triple therapy. Nevertheless it can be used in association with other clinical and biological parameters to help determine patients who will benefit from the triple regiments.ClinicalTrials.gov NCT01508286.

  12. Final Results of the Telaprevir Access Program: FibroScan Values Predict Safety and Efficacy in Hepatitis C Patients with Advanced Fibrosis or Cirrhosis

    Science.gov (United States)

    Lepida, Antonia; Colombo, Massimo; Fernandez, Inmaculada; Abdurakhmanov, Djamal; Abrao Ferreira, Paulo; Strasser, Simone I.; Urbanek, Petr; Mangia, Alessandra; Calleja, José L.; Iraqi, Wafae; DeMasi, Ralph; Lonjon-Domanec, Isabelle

    2015-01-01

    Background Liver stiffness determined by transient elastography is correlated with hepatic fibrosis stage and has high accuracy for detecting severe fibrosis and cirrhosis in chronic hepatitis C patients. We evaluated the clinical value of baseline FibroScan values for the prediction of safety and efficacy of telaprevir-based therapy in patients with advanced fibrosis and cirrhosis in the telaprevir Early Access Program HEP3002. Methods 1,772 patients with HCV-1 and bridging fibrosis or cirrhosis were treated with telaprevir plus pegylated interferon-α and ribavirin (PR) for 12 weeks followed by PR alone, the total treatment duration depending on virological response and previous response type. Liver fibrosis stage was determined either by liver biopsy or by non-invasive markers. 1,282 patients (72%) had disease stage assessed by FibroScan; among those 46% were classified as Metavir F3 at baseline and 54% as F4. Results Overall, 1,139 patients (64%) achieved a sustained virological response (SVR) by intention-to-treat analysis. Baseline FibroScan values were tested for association with SVR and the occurrence of adverse events. By univariate analysis, higher baseline FibroScan values were predictive of lower sustained virological response rates and treatment-related anemia. By multivariate analysis, FibroScan was no longer statistically significant as an independent predictor, but higher FibroScan values were correlated with the occurrence of infections and serious adverse events. Conclusions FibroScan has a limited utility as a predictor of safety and efficacy in patients treated with telaprevir-based triple therapy. Nevertheless it can be used in association with other clinical and biological parameters to help determine patients who will benefit from the triple regiments. Trial Registration ClinicalTrials.gov NCT01508286 PMID:26398503

  13. Atomic resolution imaging at 2.5 GHz using near-field microwave microscopy

    OpenAIRE

    Lee, Jonghee; Long, Christian J.; Yang, Haitao; Xiang, Xiao-Dong; Takeuchi, Ichiro

    2010-01-01

    Atomic resolution imaging is demonstrated using a hybrid scanning tunneling/near-field microwave microscope (microwave-STM). The microwave channels of the microscope correspond to the resonant frequency and quality factor of a coaxial microwave resonator, which is built in to the STM scan head and coupled to the probe tip. We find that when the tip-sample distance is within the tunneling regime, we obtain atomic resolution images using the microwave channels of the microwave-STM. We attribute...

  14. Microwave Photonics

    OpenAIRE

    A J Seeds; Liu, C. P.; Ismail, T; Fice, M. J.; Pozzi, F.; Steed, R. J.; Rouvalis, E.; Renaud, C.C.

    2010-01-01

    Microwave photonics is the use of photonic techniques for the generation, transmission, processing and reception of signals having spectral components at microwave frequencies. This tutorial reviews the technologies used and gives applications examples.

  15. False positive PET–CT scan and clinical examination in a patient with locally advanced vulvar cancer

    OpenAIRE

    Perry, LaToya J; Guralp, Onur; Al-Niaimi, Ahmed; Zucker, Noah A.; Kushner, David M.

    2013-01-01

    ► PET–CT scan was positive for metastasis of vulvar cancer to lymph nodes however they were histologically negative. ► Frozen section analysis should be performed at the time of surgery to confirm status of suspicious lymph nodes.

  16. Seismic infrared anomalies detection in the case of the Wenchuan earthquake using bi-angular advanced along-track scanning radiometer data

    OpenAIRE

    Pan Xiong; Xuhui Shen; Xingfa Gu; Qingyan Meng; Liming Zhao; Yanhua Zhao; Yan Li; Jianting Dong

    2015-01-01

    The paper has developed Robust Satellite data analysis Technique (RST) to detect seismic anomalies in the case of the Wenchuan earthquake occurred on May 12, 2008, using the bi-angular Advanced Along-Track Scanning Radiometer (AATSR) gridded brightness temperature (BT) data based on spatial/temporal continuity and confutation analysis. The proposed method has been applied to analyze the Wenchuan earthquake with longitude from 95°E to 111°E and latitude from 23°N to 39°N, and a full data-set o...

  17. Advances in Multi-Sensor Scanning and Visualization of Complex Plants: the Utmost Case of a Reactor Building

    Science.gov (United States)

    Hullo, J.-F.; Thibault, G.; Boucheny, C.

    2015-02-01

    In a context of increased maintenance operations and workers generational renewal, a nuclear owner and operator like Electricité de France (EDF) is interested in the scaling up of tools and methods of "as-built virtual reality" for larger buildings and wider audiences. However, acquisition and sharing of as-built data on a large scale (large and complex multi-floored buildings) challenge current scientific and technical capacities. In this paper, we first present a state of the art of scanning tools and methods for industrial plants with very complex architecture. Then, we introduce the inner characteristics of the multi-sensor scanning and visualization of the interior of the most complex building of a power plant: a nuclear reactor building. We introduce several developments that made possible a first complete survey of such a large building, from acquisition, processing and fusion of multiple data sources (3D laser scans, total-station survey, RGB panoramic, 2D floor plans, 3D CAD as-built models). In addition, we present the concepts of a smart application developed for the painless exploration of the whole dataset. The goal of this application is to help professionals, unfamiliar with the manipulation of such datasets, to take into account spatial constraints induced by the building complexity while preparing maintenance operations. Finally, we discuss the main feedbacks of this large experiment, the remaining issues for the generalization of such large scale surveys and the future technical and scientific challenges in the field of industrial "virtual reality".

  18. A pilot study of preoperative continuous infusion 5-fluorouracil, external microwave hyperthermia, and external beam radiotherapy for treatment of locally advanced, unresectable, or recurrent rectal cancer

    International Nuclear Information System (INIS)

    Purpose: To determine the feasibility of combining external beam radiotherapy, continuous infusion 5-fluorouracil (5-FU), and external microwave hyperthermia in patients with locally advanced, unresectable, or recurrent adenocarcinoma of the rectum. Methods and Materials: From 7/95 through 2/99, 15 patients were enrolled in the study. The treatment regimen consisted of continuous infusion 5-FU 250 mg/m2/d 7 days/week beginning on day 1, external beam radiotherapy to the pelvis, 4500 cGy, 180 cGy/d 5 days/week using a 3 or 4-field technique, and external microwave hyperthermia on days 3, 8, 15, 22, and 29. Chemotherapy was stopped on the last day of radiotherapy. Surgical resection, if feasible, was scheduled 3-6 weeks after completing thermochemoradiotherapy. For this regimen to be considered feasible, no more than 2 of the 15 patients should fail to complete therapy due to life-threatening toxicity. Toxicity was scored using National Cancer Institute Criteria. Results: All patients completed the chemoradiotherapy portion of the protocol. Eleven of the 15 patients completed all 5 hyperthermia treatments. Of the 4 patients who did not receive the full course of hyperthermia, only 1 patient had treatment stopped due to life-threatening toxicity. The other 3 patients did not complete hyperthermia due to scheduling errors (n = 2) or patient request (n = 1). Five of 15 patients required a treatment interruption due to toxicity no. >=no. Grade 3. Seven patients experienced lesser degrees of toxicity which did not require treatment interruption. Three patients experienced no side effects. The most common toxicities were dermatitis and diarrhea. Of the 14 patients in whom surgery was planned, 11 (79%) were resectable. There was one pathologic complete response. Conclusions: It is feasible to deliver thermochemoradiotherapy, as prescribed in this study, to patients with locally advanced, unresectable, or recurrent rectal cancer. The therapy is moderately toxic, with one

  19. Assimilation of Passive and Active Microwave Soil Moisture Retrievals

    Science.gov (United States)

    Draper, C. S.; Reichle, R. H.; DeLannoy, G. J. M.; Liu, Q.

    2012-01-01

    Root-zone soil moisture is an important control over the partition of land surface energy and moisture, and the assimilation of remotely sensed near-surface soil moisture has been shown to improve model profile soil moisture [1]. To date, efforts to assimilate remotely sensed near-surface soil moisture at large scales have focused on soil moisture derived from the passive microwave Advanced Microwave Scanning Radiometer (AMSR-E) and the active Advanced Scatterometer (ASCAT; together with its predecessor on the European Remote Sensing satellites (ERS. The assimilation of passive and active microwave soil moisture observations has not yet been directly compared, and so this study compares the impact of assimilating ASCAT and AMSR-E soil moisture data, both separately and together. Since the soil moisture retrieval skill from active and passive microwave data is thought to differ according to surface characteristics [2], the impact of each assimilation on the model soil moisture skill is assessed according to land cover type, by comparison to in situ soil moisture observations.

  20. Microstructural examination by TEM of WC/Co composites prepared by conventional and Microwave processes

    International Nuclear Information System (INIS)

    Recently, significant developments and advances have taken place in the field of microwave processing of ceramics, composites and metals. Microwave sintering technology of WC/Co based hard metal parts has been now developed for commercial products. Microwave processed WC/Co parts reportedly have exhibited superior performance over standard parts. Additionally, the microwave process requires only one tenth of the total cycle time employed in a conventional process. Laboratory corrosion and impact resistance tests have proved that microwave processed WC/Co parts are several times more resistant than the conventional parts of the same composition. The scanning transmission electron microscopic (STEM) examination conducted an conventionally and microwave sintered WC/Co samples exhibited remarkable difference in the chemistry of cobalt binder phase. It is understood that the superior mechanical properties of microwave sintered part are due to the pure cobalt phase present at the grain boundary of WC grains, while the conventionally sintered part showed there was substantial inter-alloying of Co with tungsten. (author)

  1. Comparison of Data From Far Ultraviolet Limb Scanning and Imaging Instrumentation Aboard the Advanced Research and Global Observation Satellite (ARGOS)

    Science.gov (United States)

    Walker, P. W.; Carruthers, G. R.; Dymond, K. F.; Finch, M. A.; McDonald, S. E.; Nicholas, A. C.; Thonnard, S. E.; Budzien, S. A.; McCoy, R. P.

    2001-05-01

    The ARGOS satellite includes two Naval Research Laboratory experiments that monitor naturally occurring far ultraviolet emissions in the Earth's upper atmosphere. Coincident observations between these two instruments, the Global Imaging Monitor of the Ionosphere (GIMI) and the Low Resolution Airglow and Auroral Spectrograph (LORAAS), have been obtained. The GIMI instrument produces 9 ° x 9 ° limb images with passband coverage between 131 and 200 nm. The LORAAS instrument provides the spectral distribution from 80 to 170 nm for 2.4 ° x 17 ° field of regard. The two instruments are coaligned aboard the spacecraft, aft-looking in the orbital plane. Preliminary comparisons of observations obtained from the imaging and scanning instruments under quiet geomagnetic conditions are reported, including irradiances and spectral distributions. By combining the GIMI data with that from LORAAS, the study of the dynamics of the ionosphere can be expanded to investigate both horizontal and vertical distrubutions and their variances. The improved capability can extend to the study of active periods with highly variable and disturbed ionospheres, and examples are discussed from data acquired during periods of high geomagnetic activity. These results provide the first direct comparison between near simultaneous limb scans and images from ARGOS, and show promise as a validation technique to improve capabilities for the study of ionospheric variability.

  2. Integrated Advanced Microwave Sounding Unit-A (AMSU-A). Performance Verification Report: Final Comprehensive Performance Test Report, P/N 1331720-2TST, S/N 105/A1

    Science.gov (United States)

    Platt, R.

    1999-01-01

    This is the Performance Verification Report, Final Comprehensive Performance Test (CPT) Report, for the Integrated Advanced Microwave Sounding Unit-A (AMSU-A). This specification establishes the requirements for the CPT and Limited Performance Test (LPT) of the AMSU-1A, referred to here in as the unit. The sequence in which the several phases of this test procedure shall take place is shown.

  3. A hard X-ray scanning microprobe for fluorescence imaging and microdiffraction at the Advanced Photon Source

    International Nuclear Information System (INIS)

    A hard x-ray scanning microprobe based on zone plate optics and undulator radiation, in the energy region from 6 to 20 keV, has reached a focal spot size (FWHM) of 0.15 microm (v) x 0.6 microm (h), and a photon flux of 4 x 109 photons/sec/0.01%BW. Using a slit 44 meters upstream to create a virtual source, a circular beam spot of 0.15 microm in diameter can be obtained with a photon flux of one order of magnitude less. During fluorescence mapping of trace elements in a single human ovarian cell, the microprobe exhibited an imaging sensitivity for Pt (La line) of 80 attograms/microm2 for a count rate of 10 counts per second. The x-ray microprobe has been used to map crystallographic strain and multiquantum well thickness in micro-optoelectronic devices produced with the selective area growth technique

  4. Scanning electron microscopy (SEM) study of advanced PMR-X Carbon fiber composites after high temperature exposure

    International Nuclear Information System (INIS)

    Degradation behavior of neat resin, epoxy sized and unsized carbon fibers in polyimide matrix were investigated. Degradation of neat resin and unidirectional laminates (08 and 06)were investigated at temperature between 470 digC-650 digBy using scanning electron microscopy technique, voids formation in neat resin, transverse cracking and microcracking at fiber-matrix interface were investigated. The results showed that PMR-X composites are more stable in an inert atmosphere (nitrogen atmosphere)than in air, degradation of PMR-X neat resin is accompanied by volatilization and microcrack formation at longitudinal and transverse direction of fiber-matrix interface with in composite panels. However, it was concluded that there is good adhesion between fiber and matrix in epoxy sized composites

  5. Microwave circulator design

    CERN Document Server

    Linkhart, Douglas K

    2014-01-01

    Circulator design has advanced significantly since the first edition of this book was published 25 years ago. The objective of this second edition is to present theory, information, and design procedures that will enable microwave engineers and technicians to design and build circulators successfully. This resource contains a discussion of the various units used in the circulator design computations, as well as covers the theory of operation. This book presents numerous applications, giving microwave engineers new ideas about how to solve problems using circulators. Design examples are provided, which demonstrate how to apply the information to real-world design tasks.

  6. Global observations of quasi-zonal bands in microwave sea surface temperature

    OpenAIRE

    Buckingham, C.E.; Cornillon, P.C.; Schloesser, F.; Obenour, K.M.

    2014-01-01

    Global observations of quasi-zonal jet-like structures have recently been reported in estimates of upper ocean circulation. To date, these observations have come primarily from float-derived and altimeter-derived estimates of zonal velocity. Here, we explore the existence of similar structures in the ocean using satellite-derived estimates of sea surface temperature (SST) from the Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E). Applying an ocean front detection...

  7. Microwave Microscope

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Makes ultra-high-resolution field measurements. The Microwave Microscope (MWM) has been used in support of several NRL experimental programs involving sea...

  8. MIKON 94. International Microwave Conference. Invited papers, volume 3

    Science.gov (United States)

    Dufrene, Roman

    The following topics are discussed: (1) New trends and ideas in the fields of microwave technology; (2) Development of dual-reflector feed for the arecibo radio telescope, an overview; (3) Advanced microwave technology in modern communication satellites; (4) Differential methods of signal selection in microwave polarimetry; (5) Anticollision car radar in the mm-wave range with pseudo-noise code modulation and digital angle evaluation; (6) Industrial microwave sensors; Theory and applications of polarimetry in radar; (7) Basic theory of radar polarimetry-an engineering approach; (8) Microwave research in agriculture; (9) Wave approach to CAD noise analysis, modeling and measurement of microwave networks; (10) Advances in technology of microwave submicrometer devices and integrated circuits; (11) Recent advances in power amplifier design methodologies; (12) Chiral media: theory and applications for microwaves; (13) State and trends in time domain electromagnetic modelling using the TLM method; and (14) Microwave remote sensing of road surface during winter time.

  9. Stabilized γ-BIMNVOX solid electrolyte: Ethylene glycol–citrate sol–gel synthesis, microwave-assisted calcination, and structural and electrical characterization

    Energy Technology Data Exchange (ETDEWEB)

    Al-Areqi, Niyazi A.S., E-mail: niyazi.alareqi@gmail.com [Department of Chemistry, Faculty of Applied Science, Taiz University, Taiz, Republic of Yemen (Yemen); Beg, Saba [Department of Chemistry, Aligarh Muslim University, Aligarh 202002 (India); Al-Alas, Ahlam [Department of Chemistry, Faculty of Applied Science, Taiz University, Taiz, Republic of Yemen (Yemen); Hafeez, Shehla [Department of Chemistry, Aligarh Muslim University, Aligarh 202002 (India)

    2013-12-25

    Highlights: •γ-BIMNVOX was synthesized by ethylene glycol–citrate sol–gel route. •γ-BIMNVOX crystallizes by 25-min microwave-assisted calcination. •Smaller particle sizes for microwave calcined BIMNVOX samples. •Best oxide-ion performance for microwave calcined BIMNVOX samples. -- Abstract: Samples of γ-BIMNVOX (Bi{sub 2}V{sub 1−x}Mn{sub x}O{sub 5.5−x/2}; 0.13 ⩽ x ⩽ 0.20) system were synthesized by an ethylene glycol–citrate sol–gel route. The resulting xerogels were then calcined by the microwave heating using a modified domestic microwave oven operated at 2.45 GHz. Microwave-assisted calcination samples in comparison with other conventionally calcined samples were characterized in terms of phase crystallization, stabilization and particle size using simultaneous thermogravimetric–differential thermal analysis (TG–DTA), X-ray powder diffraction (XRPD) and scanning electron microscopy (SEM). The AC impedance spectroscopy was employed for electrical characterization. It was found that the microwave-assisted calcination route successfully produces better crystalline stabilized γ-BIMNVOX samples with appreciably small average particle sizes after only 25 min of microwave heating. The electrical properties of microwave calcined γ-BIMNVOX system make it an advanced low-temperature solid electrolyte suitable for use in oxide-ion based electrochemical applications.

  10. Estimation of global snow cover using passive microwave data

    Science.gov (United States)

    Chang, Alfred T. C.; Kelly, Richard E.; Foster, James L.; Hall, Dorothy K.

    2003-04-01

    This paper describes an approach to estimate global snow cover using satellite passive microwave data. Snow cover is detected using the high frequency scattering signal from natural microwave radiation, which is observed by passive microwave instruments. Developed for the retrieval of global snow depth and snow water equivalent using Advanced Microwave Scanning Radiometer EOS (AMSR-E), the algorithm uses passive microwave radiation along with a microwave emission model and a snow grain growth model to estimate snow depth. The microwave emission model is based on the Dense Media Radiative Transfer (DMRT) model that uses the quasi-crystalline approach and sticky particle theory to predict the brightness temperature from a single layered snowpack. The grain growth model is a generic single layer model based on an empirical approach to predict snow grain size evolution with time. Gridding to the 25 km EASE-grid projection, a daily record of Special Sensor Microwave Imager (SSM/I) snow depth estimates was generated for December 2000 to March 2001. The estimates are tested using ground measurements from two continental-scale river catchments (Nelson River and the Ob River in Russia). This regional-scale testing of the algorithm shows that for passive microwave estimates, the average daily snow depth retrieval standard error between estimated and measured snow depths ranges from 0 cm to 40 cm of point observations. Bias characteristics are different for each basin. A fraction of the error is related to uncertainties about the grain growth initialization states and uncertainties about grain size changes through the winter season that directly affect the parameterization of the snow depth estimation in the DMRT model. Also, the algorithm does not include a correction for forest cover and this effect is clearly observed in the retrieval. Finally, error is also related to scale differences between in situ ground measurements and area-integrated satellite estimates. With AMSR

  11. A hard x-ray scanning microprobe for fluorescence imaging and microdiffraction at the advanced photon source

    International Nuclear Information System (INIS)

    A hard x-ray scanning microprobe based on zone plate optics and undulator radiation, in the energy region from 6 to 20 keV, has reached a focal spot size (FWHM) of 0.15 μm(v)x0.6 μm(h), and a photon flux of 4x109 photons/sec/0.01%BW. Using a slit 44 meters upstream to create a virtual source, a circular beam spot of 0.15 μm in diameter can be obtained with a photon flux of one order of magnitude less. During fluorescence mapping of trace elements in a single human ovarian cell, the microprobe exhibited an imaging sensitivity for Pt (Lα line) of 80 attograms/μm2 for a count rate of 10 counts per second. The x-ray microprobe has been used to map crystallographic strain and multiquantum well thickness in micro-optoelectronic devices produced with the selective area growth technique

  12. Solutions Network Formulation Report. Visible/Infrared Imager/Radiometer Suite and Advanced Microwave Scanning Radiometer Data Products for National Drought Monitor Decision Support

    Science.gov (United States)

    Estep, Leland

    2007-01-01

    Drought effects are either direct or indirect depending on location, population, and regional economic vitality. Common direct effects of drought are reduced crop, rangeland, and forest productivity; increased fire hazard; reduced water levels; increased livestock and wildlife mortality rates; and damage to wildlife and fish habitat. Indirect impacts follow on the heels of direct impacts. For example, a reduction in crop, rangeland, and forest productivity may result in reduced income for farmers and agribusiness, increased prices for food and timber, unemployment, reduced tax revenues, increased crime, foreclosures on bank loans to farmers and businesses, migration, and disaster relief programs. In the United States alone, drought is estimated to result in annual losses of between $6 - 8 billion. Recent sustained drought in the United States has made decision-makers aware of the impacts of climate change on society and environment. The eight major droughts that occurred in the United States between 1980 and 1999 accounted for the largest percentage of weather-related monetary losses. Monitoring drought and its impact that occurs at a variety of scales is an important government activity -- not only nationally but internationally as well. The NDMC (National Drought Mitigation Center) and the USDA (U.S. Department of Agriculture) RMA (Risk Management Agency) have partnered together to develop a DM-DSS (Drought Monitoring Decision Support System). This monitoring system will be an interactive portal that will provide users the ability to visualize and assess drought at all levels. This candidate solution incorporates atmospherically corrected VIIRS data products, such as NDVI (Normalized Difference Vegetation Index) and Ocean SST (sea surface temperature), and AMSR-E soil moisture data products into two NDMC vegetation indices -- VegDRI (Vegetation Drought Response Index) and VegOUT (Vegetation Outlook) -- which are then input into the DM-DSS.

  13. Microwave Ferrites for Cryogenic Applications

    OpenAIRE

    Dionne, G.

    1997-01-01

    Recent advances in microwave ferrite device technology have seen the introduction of superconductivity that virtually eliminates insertion losses due to electrical conduction in microstrip circuits. The conventional ferrimagnetic spinel and garnet compositions, however, are not generally optimized for temperatures in the vicinity of 77 K and may require chemical redesign in order to realize the full potential of these devices. For microwave transmission, absorption losses may be reduced by a ...

  14. Imaging Structure and Composition Homogeneity of 300 mm SiGe Virtual Substrates for Advanced CMOS Applications by Scanning X-ray Diffraction Microscopy.

    Science.gov (United States)

    Zoellner, Marvin H; Richard, Marie-Ingrid; Chahine, Gilbert A; Zaumseil, Peter; Reich, Christian; Capellini, Giovanni; Montalenti, Francesco; Marzegalli, Anna; Xie, Ya-Hong; Schülli, Tobias U; Häberlen, Maik; Storck, Peter; Schroeder, Thomas

    2015-05-01

    Advanced semiconductor heterostructures are at the very heart of many modern technologies, including aggressively scaled complementary metal oxide semiconductor transistors for high performance computing and laser diodes for low power solid state lighting applications. The control of structural and compositional homogeneity of these semiconductor heterostructures is the key to success to further develop these state-of-the-art technologies. In this article, we report on the lateral distribution of tilt, composition, and strain across step-graded SiGe strain relaxed buffer layers on 300 mm Si(001) wafers treated with and without chemical-mechanical polishing. By using the advanced synchrotron based scanning X-ray diffraction microscopy technique K-Map together with micro-Raman spectroscopy and Atomic Force Microscopy, we are able to establish a partial correlation between real space morphology and structural properties of the sample resolved at the micrometer scale. In particular, we demonstrate that the lattice plane bending of the commonly observed cross-hatch pattern is caused by dislocations. Our results show a strong local correlation between the strain field and composition distribution, indicating that the adatom surface diffusion during growth is driven by strain field fluctuations induced by the underlying dislocation network. Finally, it is revealed that a superficial chemical-mechanical polishing of cross-hatched surfaces does not lead to any significant change of tilt, composition, and strain variation compared to that of as-grown samples. PMID:25871429

  15. [Atmospheric Influences Analysis on the Satellite Passive Microwave Remote Sensing].

    Science.gov (United States)

    Qiu, Yu-bao; Shi, Li-juan; Shi, Jian-cheng; Zhao, Shao-jie

    2016-02-01

    Passive microwave remote sensing offers its all-weather work capabilities, but atmospheric influences on satellite microwave brightness temperature were different under different atmospheric conditions and environments. In order to clarify atmospheric influences on Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E), atmospheric radiation were simulated based on AMSR-E configuration under clear sky and cloudy conditions, by using radiative transfer model and atmospheric conditions data. Results showed that atmospheric water vapor was the major factor for atmospheric radiation under clear sky condition. Atmospheric transmittances were almost above 0.98 at AMSR-E's low frequencies (vapor needed to be corrected when using microwave high-frequency channels to inverse land surface parameters in clear sky condition. But under cloud cover or cloudy conditions, cloud liquid water was the key factor to cause atmospheric radiation. When sky was covered by typical stratus cloud, atmospheric transmittances at 10.7, 18.7 and 36.5 GHz were 0.942, 0.828 and 0.605 respectively. Comparing with the clear sky condition, the down-welling atmospheric radiation caused by cloud liquid water increased up to 75.365 K at 36.5 GHz. It showed that the atmospheric correction under different clouds covered condition was the primary work to improve the accuracy of land surface parameters inversion of passive microwave remote sensing. The results also provided the basis for microwave atmospheric correction algorithm development. Finally, the atmospheric sounding data was utilized to calculate the atmospheric transmittance of Hailaer Region, Inner Mongolia province, in July 2013. The results indicated that atmospheric transmittances were close to 1 at C-band and X-band. 89 GHz was greatly influenced by water vapor and its atmospheric transmittance was not more than 0.7. Atmospheric transmittances in Hailaer Region had a relatively stable value in summer, but had about 0

  16. Soil-Vegetation-Atmosphere Radiative Transfer Model in Microwave Region

    Institute of Scientific and Technical Information of China (English)

    JIA Yuanyuan; LI Zhaoliang

    2008-01-01

    The radiative transfer is one of the significant theories that describe the processes of scattering,emission,and absorption of electromagnetic radiant intensity through scattering medium.It is the basis of the study on the quantitative remote sensing.In this paper,the radiative characteristics of soil,vegetation,and atmosphere were described respectively.The numerical solution of radiative transfer was accomplished by Successive Orders of Scattering (SOS).A radiative transfer model for simulating microwave brightness temperature over land surfaces was constructed,designed,and implemented.Analyzing the database generated from soil-vegetation-atmosphere radiative transfer model under Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E) configuration showed that the atmospheric effects on microwave brightness temperature should not be neglected,particularly for higher frequency,and can be parameterized.At the same time,the relationship between the emissivities of the different channels was developed.The study results will promote the development of algorithm to retrieve geophysical parameters from microwave remotely sensed data.

  17. Quantifying Uncertainties in Land-Surface Microwave Emissivity Retrievals

    Science.gov (United States)

    Tian, Yudong; Peters-Lidard, Christa D.; Harrison, Kenneth W.; Prigent, Catherine; Norouzi, Hamidreza; Aires, Filipe; Boukabara, Sid-Ahmed; Furuzawa, Fumie A.; Masunaga, Hirohiko

    2013-01-01

    Uncertainties in the retrievals of microwaveland-surface emissivities are quantified over two types of land surfaces: desert and tropical rainforest. Retrievals from satellite-based microwave imagers, including the Special Sensor Microwave Imager, the Tropical Rainfall Measuring Mission Microwave Imager, and the Advanced Microwave Scanning Radiometer for Earth Observing System, are studied. Our results show that there are considerable differences between the retrievals from different sensors and from different groups over these two land-surface types. In addition, the mean emissivity values show different spectral behavior across the frequencies. With the true emissivity assumed largely constant over both of the two sites throughout the study period, the differences are largely attributed to the systematic and random errors inthe retrievals. Generally, these retrievals tend to agree better at lower frequencies than at higher ones, with systematic differences ranging 1%-4% (3-12 K) over desert and 1%-7% (3-20 K) over rainforest. The random errors within each retrieval dataset are in the range of 0.5%-2% (2-6 K). In particular, at 85.5/89.0 GHz, there are very large differences between the different retrieval datasets, and within each retrieval dataset itself. Further investigation reveals that these differences are most likely caused by rain/cloud contamination, which can lead to random errors up to 10-17 K under the most severe conditions.

  18. Interpreting snowpack radiometry using currently existing microwave radiative transfer models

    Science.gov (United States)

    Kang, D. H.; Tan, S.; Kim, E. J.

    2015-12-01

    A radiative transfer model (RTM) to calculate a snow brightness temperature (Tb) is a critical element to retrieve terrestrial snow from microwave remote sensing observations. The RTM simulates the Tb based on a layered snow by solving a set of microwave radiative transfer formulas. Even with the same snow physical inputs used for the RTM, currently existing models such as Microwave Emission Model of Layered Snowpacks (MEMLS), Dense Media Radiative Transfer (DMRT-Tsang), and Helsinki University of Technology (HUT) models produce different Tb responses. To backwardly invert snow physical properties from the Tb, the differences from the RTMs are to be quantitatively explained. To this end, the paper evaluates the sources of perturbations in the RTMs, and reveals the equations where the variations are made among three models. Investigations are conducted by providing the same but gradual changes in snow physical inputs such as snow grain size, and snow density to the 3 RTMs. Simulations are done with the frequencies consistent with the Advanced Microwave Scanning Radiometer-E (AMSR-E) at 6.9, 10.7, 18.7, 23.8, 36.5, and 89.0 GHz. For realistic simulations, the 3 RTMs are simultaneously driven by the same snow physics model with the meteorological forcing datasets and are validated from the snow core samplings from the CLPX (Cold Land Processes Field Experiment) 2002-2003, and NoSREx (Nordic Snow Radar Experiment) 2009-2010.

  19. Recent Improvements in Retrieving Near-Surface Air Temperature and Humidity Using Microwave Remote Sensing

    Science.gov (United States)

    Roberts, J. Brent

    2010-01-01

    Detailed studies of the energy and water cycles require accurate estimation of the turbulent fluxes of moisture and heat across the atmosphere-ocean interface at regional to basin scale. Providing estimates of these latent and sensible heat fluxes over the global ocean necessitates the use of satellite or reanalysis-based estimates of near surface variables. Recent studies have shown that errors in the surface (10 meter)estimates of humidity and temperature are currently the largest sources of uncertainty in the production of turbulent fluxes from satellite observations. Therefore, emphasis has been placed on reducing the systematic errors in the retrieval of these parameters from microwave radiometers. This study discusses recent improvements in the retrieval of air temperature and humidity through improvements in the choice of algorithms (linear vs. nonlinear) and the choice of microwave sensors. Particular focus is placed on improvements using a neural network approach with a single sensor (Special Sensor Microwave/Imager) and the use of combined sensors from the NASA AQUA satellite platform. The latter algorithm utilizes the unique sampling available on AQUA from the Advanced Microwave Scanning Radiometer (AMSR-E) and the Advanced Microwave Sounding Unit (AMSU-A). Current estimates of uncertainty in the near-surface humidity and temperature from single and multi-sensor approaches are discussed and used to estimate errors in the turbulent fluxes.

  20. Microwave superheaters for fusion

    International Nuclear Information System (INIS)

    The microwave superheater uses the synchrotron radiation from a thermonuclear plasma to heat gas seeded with an alkali metal to temperatures far above the temperature of material walls. It can improve the efficiency of the Compact Fusion Advanced Rankine (CFAR) cycle described elsewhere in these proceedings. For a proof-of-principle experiment using helium, calculations show that a gas superheat ΔT of 20000K is possible when the wall temperature is maintained at 10000K. The concept can be scaled to reactor grade systems. Because of the need for synchrotron radiation, the microwave superheater is best suited for use with plasmas burning an advanced fuel such as D-3He. 5 refs

  1. Microwave Measurements

    CERN Document Server

    Skinner, A D

    2007-01-01

    The IET has organised training courses on microwave measurements since 1983, at which experts have lectured on modern developments. Their lecture notes were first published in book form in 1985 and then again in 1989, and they have proved popular for many years with a readership beyond those who attended the courses. The purpose of this third edition of the lecture notes is to bring the latest techniques in microwave measurements to this wider audience. The book begins with a survey of the theory of current microwave circuits and continues with a description of the techniques for the measureme

  2. Radionucleotide scanning in osteomyelitis

    International Nuclear Information System (INIS)

    Radionucleotide bone scanning can be an excellent adjunct to the standard radiograph and clinical findings in the diagnosis of osteomyelitis. Bone scans have the ability to detect osteomyelitis far in advance of the standard radiograph. The sequential use of technetium and gallium has been useful in differentiating cellulitis and osteomyelitis. Serial scanning with technetium and gallium may be used to monitor the response of osteomyelitis to antibiotic therapy

  3. Microwave Multicomponent Synthesis

    OpenAIRE

    Helmut M Hügel

    2009-01-01

    In the manner that very important research is often performed by multidisciplinary research teams, the applications of multicomponent reactions involving the combination of multiple starting materials with different functional groups leading to the higher efficiency and environmentally friendly construction of multifunctional/complex target molecules is growing in importance. This review will explore the advances and advantages in microwave multicomponent synthesis (MMS) that have been achiev...

  4. Quantitative study of lung perfusion SPECT scanning and pulmonary function testing for early radiation-induced lung injury in patients with locally advanced non-small cell lung cancer

    OpenAIRE

    Zhang, Wei; WANG, JIEZHONG; TANG, MINGDENG; Pan, Jianji; Bai, Penggang; LIN, DUANYU; QIAN, FEIYU; LIN, FENGJIE; YANG, XUEQIN; Zhang, Shengli

    2012-01-01

    Radiation lung injury is a common side-effect of pulmonary radiotherapy. The aim of this study was to quantitatively assess early changes in lung perfusion single photon emission computed tomography (SPECT) scanning and pulmonary function testing (PFT) prior to and after intensity modulated radiotherapy (IMRT) for patients suffering from locally advanced non-small cell lung cancer (LANSCLC). Twenty patients with LANSCLC received lung perfusion SPECT scanning and PFT prior to IMRT and immediat...

  5. Advanced Transport Operating Systems Program

    Science.gov (United States)

    White, John J.

    1990-01-01

    NASA-Langley's Advanced Transport Operating Systems Program employs a heavily instrumented, B 737-100 as its Transport Systems Research Vehicle (TRSV). The TRSV has been used during the demonstration trials of the Time Reference Scanning Beam Microwave Landing System (TRSB MLS), the '4D flight-management' concept, ATC data links, and airborne windshear sensors. The credibility obtainable from successful flight test experiments is often a critical factor in the granting of substantial commitments for commercial implementation by the FAA and industry. In the case of the TRSB MLS, flight test demonstrations were decisive to its selection as the standard landing system by the ICAO.

  6. Prospects of microwave processing: An overview

    Indian Academy of Sciences (India)

    S Das; A K Mukhopadhyay; S Datta; D Basu

    2009-02-01

    Microwave processing has been emerging as an innovative sintering method for many traditional ceramics, advanced ceramics, specialty ceramics and ceramic composites as well as polymer and polymer composites. Development of functionally gradient materials: joining; melting; fibre drawing; reaction synthesis of ceramics; synthesis of ceramic powder, phosphor materials, whiskers, microtubes and nanotubes; sintering of zinc oxide varistors; glazing of coating surface and coating development have been performed using microwave heating. In addition, microwave energy is being explored for the sintering of metal powders also. Ceramic and metal nanopowders have been sintered in microwave. Furthermore, initiatives have been taken to process the amorphous materials (e.g. glass) by microwave heating. Besides this, attempt has been made to study the heating behaviour of materials in the electric and magnetic fields at microwave frequencies. The research is now focused on the use of microwave processing for industrial applications.

  7. Prospects of microwave processing: An overview

    Indian Academy of Sciences (India)

    S Das; A K Mukhopadhyay; S Datta; D Basu

    2008-12-01

    Microwave processing has been emerging as an innovative sintering method for many traditional ceramics, advanced ceramics, specialty ceramics and ceramic composites as well as polymer and polymer composites. Development of functionally gradient materials, joining, melting, fibre drawing, reaction synthesis of ceramics, synthesis of ceramic powder, phosphor materials, whiskers, microtubes and nanotubes, sintering of zinc oxide varistors, glazing of coating surface and coating development have been performed using microwave heating. In addition, microwave energy is being explored for the sintering of metal powders also. Ceramic and metal nanopowders have been sintered in microwave. Furthermore, initiatives have been taken to process the amorphous materials (e.g. glass) by microwave heating. Besides this, an attempt has been made to study the heating behaviour of materials in the electric and magnetic fields at microwave frequencies. The research is now focused on the use of microwave processing for industrial applications.

  8. Microwave Ovens

    Science.gov (United States)

    ... Radiation-Emitting Products and Procedures Home, Business, and Entertainment Products Microwave Ovens Share Tweet Linkedin Pin it More ... Exporting Electronic Products More in Home, Business, and Entertainment Products Cell Phones Health Issues Reducing Exposure: Hands-free ...

  9. Nuclear Scans

    Science.gov (United States)

    Nuclear scans use radioactive substances to see structures and functions inside your body. They use a special ... images. Most scans take 20 to 45 minutes. Nuclear scans can help doctors diagnose many conditions, including ...

  10. Microwave synthesis of zirconia nanoparticles.

    Science.gov (United States)

    Hembram, K P S S; Rao, G Mohan

    2008-08-01

    Zirconia nanoparticles were prepared by microwave synthesis from zirconium acetate hydroxide. The samples were characterized by various techniques like X-ray diffraction (XRD), Scanning Electron microscopy (SEM), Transmission Electron microscopy (TEM), Raman Spectroscopy (RS). By XRD the average crystallite size is obtained around 10 nm and which is comparable to observation by SEM and TEM. PMID:19049194

  11. Prediction of neoadjuvant radiation chemotherapy response and survival using pretreatment [18F]FDG PET/CT scans in locally advanced rectal cancer

    International Nuclear Information System (INIS)

    The aim of this study was to investigate metabolic and textural parameters from pretreatment [18F]FDG PET/CT scans for the prediction of neoadjuvant radiation chemotherapy response and 3-year disease-free survival (DFS) in patients with locally advanced rectal cancer (LARC). We performed a retrospective review of 74 patients diagnosed with LARC who were initially examined with [18F]FDG PET/CT, and who underwent neoadjuvant radiation chemotherapy followed by complete resection. The standardized uptake value (mean, peak, and maximum), metabolic volume (MV), and total lesion glycolysis of rectal cancer lesions were calculated using the isocontour method with various thresholds. Using three-dimensional textural analysis, about 50 textural features were calculated for PET images. Response to neoadjuvant radiation chemotherapy, as assessed by histological tumour regression grading (TRG) after surgery and 3-year DFS, was evaluated using univariate/multivariate binary logistic regression and univariate/multivariate Cox regression analyses. MVs calculated using the thresholds mean standardized uptake value of the liver + two standard deviations (SDs), and mean standard uptake of the liver + three SDs were significantly associated with TRG. Textural parameters from histogram-based and co-occurrence analysis were significantly associated with TRG. However, multivariate analysis revealed that none of these parameters had any significance. On the other hand, MV calculated using various thresholds was significantly associated with 3-year DFS, and MV calculated using a higher threshold tended to be more strongly associated with 3-year DFS. In addition, textural parameters including kurtosis of the absolute gradient (GrKurtosis) were significantly associated with 3-year DFS. Multivariate analysis revealed that GrKurtosis could be a prognostic factor for 3-year DFS. Metabolic and textural parameters from initial [18F]FDG PET/CT scans could be indexes to assess tumour heterogeneity

  12. Prediction of neoadjuvant radiation chemotherapy response and survival using pretreatment [{sup 18}F]FDG PET/CT scans in locally advanced rectal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Bang, Ji-In; Ha, Seunggyun; Kim, Sang Eun [Seoul National University Bundang Hospital, Department of Nuclear Medicine, Seoul National University College of Medicine, Seongnam (Korea, Republic of); Kang, Sung-Bum; Oh, Heung-Kwon [Seoul National University Bundang Hospital, Department of Surgery, Seoul National University College of Medicine, Seongnam (Korea, Republic of); Lee, Keun-Wook [Seoul National University Bundang Hospital, Department of Internal Medicine, Seongnam (Korea, Republic of); Lee, Hye-Seung [Seoul National University Bundang Hospital, Department of Pathology, Seoul National University College of Medicine, Seongnam (Korea, Republic of); Kim, Jae-Sung [Seoul National University Bundang Hospital, Department of Radiation Oncology, Seongnam (Korea, Republic of); Lee, Ho-Young [Seoul National University Bundang Hospital, Department of Nuclear Medicine, Seoul National University College of Medicine, Seongnam (Korea, Republic of); Seoul National University, Cancer Research Institute, Seoul (Korea, Republic of)

    2016-03-15

    The aim of this study was to investigate metabolic and textural parameters from pretreatment [{sup 18}F]FDG PET/CT scans for the prediction of neoadjuvant radiation chemotherapy response and 3-year disease-free survival (DFS) in patients with locally advanced rectal cancer (LARC). We performed a retrospective review of 74 patients diagnosed with LARC who were initially examined with [{sup 18}F]FDG PET/CT, and who underwent neoadjuvant radiation chemotherapy followed by complete resection. The standardized uptake value (mean, peak, and maximum), metabolic volume (MV), and total lesion glycolysis of rectal cancer lesions were calculated using the isocontour method with various thresholds. Using three-dimensional textural analysis, about 50 textural features were calculated for PET images. Response to neoadjuvant radiation chemotherapy, as assessed by histological tumour regression grading (TRG) after surgery and 3-year DFS, was evaluated using univariate/multivariate binary logistic regression and univariate/multivariate Cox regression analyses. MVs calculated using the thresholds mean standardized uptake value of the liver + two standard deviations (SDs), and mean standard uptake of the liver + three SDs were significantly associated with TRG. Textural parameters from histogram-based and co-occurrence analysis were significantly associated with TRG. However, multivariate analysis revealed that none of these parameters had any significance. On the other hand, MV calculated using various thresholds was significantly associated with 3-year DFS, and MV calculated using a higher threshold tended to be more strongly associated with 3-year DFS. In addition, textural parameters including kurtosis of the absolute gradient (GrKurtosis) were significantly associated with 3-year DFS. Multivariate analysis revealed that GrKurtosis could be a prognostic factor for 3-year DFS. Metabolic and textural parameters from initial [{sup 18}F]FDG PET/CT scans could be indexes to assess

  13. Special Sensor Microwave Imager/Sounder (SSMIS) Temperature Data Record (TDR) in netCDF

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Special Sensor Microwave Imager/Sounder (SSMIS) is a series of passive microwave conically scanning imagers and sounders onboard the DMSP satellites beginning...

  14. Special Sensor Microwave Imager/Sounder (SSMIS) Sensor Data Record (SDR) in netCDF

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Special Sensor Microwave Imager/Sounder (SSMIS) is a series of passive microwave conically scanning imagers and sounders onboard the DMSP satellites beginning...

  15. Passive microwave precipitation detection biases: Relationship to cloud morphology

    Science.gov (United States)

    Marter, R. E.; Rapp, A. D.

    2015-12-01

    Accurate measurement of the Earth's hydrologic cycle requires a more precise understanding of precipitation accumulation and intensity on a global scale. While there is a long record of passive microwave satellite measurements, passive microwave rainfall retrievals often fail to detect light precipitation or have light rain intensity biases because they cannot differentiate between emission from cloud and rain water. Previous studies have shown that AMSR-E significantly underestimates rainfall occurrence and volume compared to CloudSat. This underestimation totals just below 0.6 mm/day quasi-globally (60S-60N), but there are larger regional variations related to the dominant cloud regime. This study aims to use Moderate Resolution Imaging Spectroradiometer (MODIS) and the 94-GHz CloudSat Cloud Profiling Radar (CPR), which has a high sensitivity to light rain, with the Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) observations, to help better characterize the properties of clouds that lead to passive microwave rainfall detection biases. CPR cloud and precipitation retrievals. AMSR-E Level-2B Goddard Profiling 2010 Algorithm (GPROF 2010) rainfall retrievals, and MODIS cloud properties were collocated and analyzed for 2008. Results are consistent with past studies and show large passive microwave precipitation detection biases compared to CloudSat in stratocumulus and shallow cumulus regimes. A preliminary examination of cases where AMSR-E failed to detect precipitation detected by CloudSat shows that over 50% of missed warm precipitation occurs in clouds with top heights below 2 km. MODIS cloud microphysical and macrophysical properties, such as optical thickness, particle effective radius, and liquid water path will be analyzed when precipitation is detected by CloudSat and missed by AMSR-E. The overall goal is to understand how cloud morphology relates to detection biases.

  16. Microwave processing of ceramic oxide filaments

    Energy Technology Data Exchange (ETDEWEB)

    Vogt, G.J.; Katz, J.D. [Los Alamos National Laboratory, NM (United States)

    1995-05-01

    The objective of the microwave filament processing project is to develop microwave techniques at 2.45 GHZ to manufacture continuous ceramic oxide filaments. Microwave processing uses the volumetric absorption of microwave power in oxide filament tows to drive off process solvents, to burn out organic binders, and to sinter the dried fibers to produce flexible, high-strength ceramic filaments. The technical goal is to advance filament processing technology by microwave heating more rapidly with less energy and at a lower cost than conventional processing, but with the same quality as conventional processing. The manufacturing goal is to collaborate with the 3M Company, a US manufacturer of ceramic oxide filaments, to evaluate the technology using a prototype filament system and to transfer the microwave technology to the 3M Company.

  17. The construction and application of the AMSR-E global microwave emissivity database

    International Nuclear Information System (INIS)

    Land surface microwave emissivity is an important parameter to describe the characteristics of terrestrial microwave radiation, and is the necessary input amount for inversion various geophysical parameters. We use brightness temperature of the Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E) and synchronous land surface temperature and atmospheric temperature-humidity profile data obtained from the MODIS which aboard on satellite AQUA the same as AMSR-E, to retrieved microwave emissivity under clear sky conditions. After quality control, evaluation and design, the global microwave emissivity database of AMSR-E under clear sky conditions is established. This database include 2002–2011 years, different regions, different surface coverage, dual-polarized, 6.9,10.65, 18.7, 23.8, 36.5 and 89GHz, ascending and descending orbit, spatial resolution 25km, global 0.05 degrees, instantaneous and half-month averaged emissivity data. The database can provide the underlying surface information for precipitation algorithm, water-vapor algorithm, and long-resolution mode model (General Circulation Model (GCM) etc.). It also provides underlying surface information for the satellite simulator, and provides basic prior knowledge of land surface radiation for future satellite sensors design. The emissivity database or the fast emissivity obtained can get ready for climate model, energy balance, data assimilation, geophysical model simulation, inversion and estimates of the physical parameters under the cloud cover conditions

  18. Use of positron emission tomography scan response to guide treatment change for locally advanced gastric cancer: the Memorial Sloan Kettering Cancer Center experience

    Science.gov (United States)

    Won, Elizabeth; Shah, Manish A.; Schöder, Heiko; Strong, Vivian E.; Coit, Daniel G.; Brennan, Murray F.; Kelsen, David P.; Janjigian, Yelena Y.; Tang, Laura H.; Capanu, Marinela; Rizk, Nabil P.; Allen, Peter J.; Bains, Manjit S.

    2016-01-01

    Background Early metabolic response on 18-fluorodeoxyglucose-positron emission tomography (FDG-PET) during neoadjuvant chemotherapy is PET non-responders have poor outcomes whether continuing chemotherapy or proceeding directly to surgery. Use of PET may identify early treatment failure, sparing patients from inactive therapy and allowing for crossover to alternative therapies. We examined the effectiveness of PET directed switching to salvage chemotherapy in the PET non-responders. Methods Patients with locally advanced resectable FDG-avid gastric or gastroesophageal junction (GEJ) adenocarcinoma received bevacizumab 15 mg/kg, epirubicin 50 mg/m2, cisplatin 60 mg/m2 day 1, and capecitabine 625 mg/m2 bid (ECX) every 21 days. PET scan was obtained at baseline and after cycle 1. PET responders, (i.e., ≥35% reduction in FDG uptake at the primary tumor) continued ECX + bev. Non-responders switched to docetaxel 30 mg/m2, irinotecan 50 mg/mg2 day 1 and 8 plus bevacizumab every 21 days for 2 cycles. Patients then underwent surgery. The primary objective was to improve the 2-year disease free survival (DFS) from 30% (historical control) to 53% in the non-responders. Results Twenty evaluable patients enrolled before the study closed for poor accrual. Eleven were PET responders and the 9 non-responders switched to the salvage regimen. With a median follow-up of 38.2 months, the 2-year DFS was 55% [95% confidence interval (CI), 30–85%] in responders compared with 56% in the non-responder group (95% CI, 20–80%, P=0.93). Conclusions The results suggest that changing chemotherapy regimens in PET non-responding patients may improve outcomes. Results from this pilot trial are hypothesis generating and suggest that PET directed neoadjuvant therapy merits evaluation in a larger trial.

  19. Characterization of errors in a coupled snow hydrology-microwave emission model

    Science.gov (United States)

    Andreadis, K.M.; Liang, D.; Tsang, L.; Lettenmaier, D.P.; Josberger, E.G.

    2008-01-01

    Traditional approaches to the direct estimation of snow properties from passive microwave remote sensing have been plagued by limitations such as the tendency of estimates to saturate for moderately deep snowpacks and the effects of mixed land cover within remotely sensed pixels. An alternative approach is to assimilate satellite microwave emission observations directly, which requires embedding an accurate microwave emissions model into a hydrologic prediction scheme, as well as quantitative information of model and observation errors. In this study a coupled snow hydrology [Variable Infiltration Capacity (VIC)] and microwave emission [Dense Media Radiative Transfer (DMRT)] model are evaluated using multiscale brightness temperature (TB) measurements from the Cold Land Processes Experiment (CLPX). The ability of VIC to reproduce snowpack properties is shown with the use of snow pit measurements, while TB model predictions are evaluated through comparison with Ground-Based Microwave Radiometer (GBMR), air-craft [Polarimetric Scanning Radiometer (PSR)], and satellite [Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E)] TB measurements. Limitations of the model at the point scale were not as evident when comparing areal estimates. The coupled model was able to reproduce the TB spatial patterns observed by PSR in two of three sites. However, this was mostly due to the presence of relatively dense forest cover. An interesting result occurs when examining the spatial scaling behavior of the higher-resolution errors; the satellite-scale error is well approximated by the mode of the (spatial) histogram of errors at the smaller scale. In addition, TB prediction errors were almost invariant when aggregated to the satellite scale, while forest-cover fractions greater than 30% had a significant effect on TB predictions. ?? 2008 American Meteorological Society.

  20. CT Scans

    Science.gov (United States)

    ... cross-sectional pictures of your body. Doctors use CT scans to look for Broken bones Cancers Blood clots Signs of heart disease Internal bleeding During a CT scan, you lie still on a table. The table ...

  1. Thyroid scan

    Science.gov (United States)

    ... PET scan Skin nodules Thyroid cancer Thyroid cancer - medullary carcinoma Thyroid cancer - papillary carcinoma Toxic nodular goiter ... Topics Hyperthyroidism Hypothyroidism Nuclear Scans Thyroid Cancer Thyroid Diseases Thyroid Tests Browse the Encyclopedia A.D.A. ...

  2. Imaging Techniques for Microwave Diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Donne, T. [FOM-Institute for Plasma Physics Rijnhuizen, Trilateral Euregio Cluster, PO Box 1207, 3430 BE Nieuwegein (Netherlands); Luhmann Jr, N.C. [University of California, Davis, CA 95616 (United States); Park, H.K. [POSTECH, Pohang, Gyeongbuk 790-784 (Korea, Republic of); Tobias, B.

    2011-07-01

    Advances in microwave technology have made it possible to develop a new generation of microwave imaging diagnostics for measuring the parameters of magnetic fusion devices. The most prominent of these diagnostics is electron cyclotron emission imaging (ECE-I). After the first generation of ECE-I diagnostics utilized at the TEXT-U, RTP and TEXTOR tokamaks and the LHD stellarator, new systems have recently come into operation on ASDEX-UG and DIII-D, soon to be followed by a system on KSTAR. The DIII-D and KSTAR systems feature dual imaging arrays that observe different parts of the plasma. The ECE-I diagnostic yields two-dimensional movies of the electron temperature in the plasma and has given already new insights into the physics of sawtooth oscillations, tearing modes and edge localized modes. Microwave Imaging Reflectometry (MIR) is used on LHD to measure electron density fluctuations. A pilot MIR system has been tested at TEXTOR and, based on the promising results, a new system is now under design for KSTAR. The system at TEXTOR was used to measure the plasma rotation velocity. The system at KSTAR and also the one on LHD will be/are used for measuring the profile of the electron density fluctuations in the plasma. Other microwave imaging diagnostics are phase imaging interferometry, and imaging microwave scattering. The emphasis in this paper will be largely focused on ECE-I. First an overview of the advances in microwave technology are discussed, followed by a description of a typical ECE-I system along with some typical experimental results. Also the utilization of imaging techniques in other types of microwave diagnostics will be briefly reviewed. This document is composed of the slides of the presentation. (authors)

  3. Inter-Sensor Comparison of Microwave Land Surface Emissivity Products to Improve Precipitation Retrievals

    Science.gov (United States)

    Norouzi, H.; Temimi, M.; Turk, J.; Prigent, C.; Furuzawa, F.; Tian, Y.

    2013-12-01

    Microwave land surface emissivity acts as the background signal to estimate rain rate, cloud liquid water, and total precipitable water. Therefore, its accuracy can directly affect the uncertainty of such measurements. Over land, unlike over oceans, the microwave emissivity is relatively high and and varies significantly as surface conditions and land cover change. Lack of ground truth measurement of microwave emissivity especially on global scale has made the uncertainty analysis of this parameter very challenging. The present study investigates the consistency among the existing global land emissivity estimates from different microwave sensors. The products are determined from various sensors and frequencies ranging from 7 to 90 GHz. The selected emissivity products in this study are from the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) by NOAA - Cooperative remote Sensing and Science and Technology Center (CREST), the Special Sensor Microwave Imager (SSM/I) by The Centre National de la Recherche Scientifique (CNRS) in France, TRMM Microwave Imager (TMI) by Nagoya University, Japan, and WindSat by NASA Jet Propulsion Laboratory (JPL). The emissivity estimates are based on different algorithms and ancillary data sets. This work investigates the difference among these emissivity products from 2003 to 2008 dynamically and spectrally. The similarities and discrepancies of the retrievals are studied at different land cover types. The mean relative difference (MRD) and other statistical parameters are calculated temporally for all five years of the study. Some inherent discrepancies between the selected products can be attributed to the difference in geometry in terms of incident angle, spectral response, and the foot print size which can affect the estimations. The results reveal that in lower frequencies (=emissivity retrievals, while in higher frequencies (>19 GHz) the residuals of atmospheric effect on the signal cause inconsistency among the products

  4. Detection of tectonic activities associated with earthquakes by satellite-borne microwave radiometer

    International Nuclear Information System (INIS)

    Complete text of publication follows. By the recent development of a remote sensing technology, we obtained new measurements to more deeply understand the condition of the Earth's surface. For example, interferograms formed by the data of a satellite-borne synthetic aperture radar (SAR) enables us to detect faint land-surface deformations in connection with volcanic eruptions or earthquakes. However, since the time lag between two scenes of SAR used to form interferograms becomes longer than the recurrent period of a satellite aboard it, it is not clear enough when land-surface deformations occur in volcanic eruptions or earthquakes. Therefore, we have investigated another approach to detect land-surface deformations with shorter time resolution from the data of satellite-borne sensors. Nowadays, it was experimentally confirmed that microwave energy is emitted when rocks are fractured. Land-surface deformations are likely to be accompanied by rock failures. Therefore, if rocks are crushed by land-surface deformations, microwave energy generated by rock failures is likely to be detected by a satellite-borne microwave radiometer. Based on this concept, we developed an algorithm to evaluate microwave energy generated by rock failures. An actual development and verification of the algorithm were performed by using the data of the Advanced Microwave Scanning Radiometer for Earth Observation System (AMSR-E) for the major earthquakes which occurred since the observation started. By the algorithm, we detected definitive microwave signals at the time when the main shock occurred with respect to some earthquakes. These microwave signals are highly likely to be associated with phenomena caused by tectonic activities in earthquakes. In this presentation, the process of development and verification of the algorithm is presented.

  5. GEO Sounding Using Microwave Instruments

    Science.gov (United States)

    Shiue, James; Krimchansky, Sergey; Susskind, Joel; Krimchansky, Alexander; Chu, Donald; Davis, Martin

    2004-01-01

    There are several microwave instruments in low Earth orbit (LEO) that are used for atmospheric temperature and humidity sounding in conjunction with companion IR sounders as well as by themselves. These instruments have achieved a certain degree of maturity and undergoing a redesign to minimize their size, mass, and power from the previous generation instruments. An example of these instruments is the AMSU-A series, now flying on POES and AQUA spacecraft with the IR sounders HIRS and AIRS. These older microwave instruments are going to be replaced by the ATMS instruments that will fly on NPP and NPOESS satellites with the CrIS sounder. A number of techniques learned from the ATMS project in instrument hardware design and data processing are directly applicable to a similar microwave sounder on a geosynchronous platform. These techniques can significantly simplify the design of a Geostationary orbit (GEO) microwave instrument, avoiding costly development and minimizing the risk of not being able to meet the scientific requirements. In fact, some of the 'enabling' technology, such as the use of MMIC microwave components (which is the basis for the ATMS' much reduced volume) can be directly applied to a GEO sounder. The benefits of microwave sounders are well known; for example, they penetrate non-precipitating cloud cover and allow for use of colocated IR observations in up to 80% cloud cover. The key advantages of a microwave instrument in GEO will be the ability to provide high temporal resolution as well as uniform spatial resolution and extend the utility of a colocated advanced IR sounder to cases in which partial cloud cover exists. A footprint of the order of 100 km by 100 km resolution with hemispherical coverage within one hour can be easily achieved for sounding channels in the 50 to 59 GHz range. A GEO microwave sounder will also allow mesoscale sampling of select regions.

  6. Using Passive Microwaves for Open Water Monitoring and Flood Forecasting

    Science.gov (United States)

    Parinussa, R.; Johnson, F.; Sharma, A.; Lakshmi, V.

    2015-12-01

    One of the biggest and severest natural disasters that society faces is floods. An important component that can help in reducing the impact of floods is satellite remote sensing as it allows for consistent monitoring and obtaining catchment information in absence of physical contact. Nowadays, passive microwave remote sensing observations are available in near real time (NRT) with a couple of hours delay from the actual sensing. The Advanced Microwave Scanning Radiometer 2 (AMSR2) is a multi-frequency passive microwave sensor onboard the Global Change Observation Mission 1 - Water that was launched in May 2012. Several of these frequencies have a high sensitivity to the land surface and they also have the capacity to penetrate clouds. These advantages come at the cost of the relatively coarse spatial resolution (footprints range from ~5 to ~50 km) which in turn allows for global monitoring. A relatively simple methodology to monitor the fraction of open water from AMSR2 observations is presented here. Low frequency passive microwave observations have sensitivity to the land surface but are modulated by overlying signals from physical temperature and vegetation cover. We developed a completely microwave based artificial neural network supported by physically based components to monitor the fraction of open water. Three different areas, located in China, Southeast Asia and Australia, were selected for testing purposes and several different characteristics were examined. First, the overall performance of the methodology was evaluated against the NASA NRT Global Flood Mapping system. Second, the skills of the various different AMSR2 frequencies were tested and revealed that artificial contamination is a factor to consider. The different skills of the tested frequencies are of interest to apply the methodology to alternative passive microwave sensors. This will be of benefit in using the numerous multi-frequency passive microwaves sensors currently observing our Earth

  7. Microwave Filters

    OpenAIRE

    Zhou, Jiafeng

    2010-01-01

    The general theory of microwave filter design based on lumped-element circuit is described in this chapter. The lowpass prototype filters with Butterworth, Chebyshev and quasielliptic characteristics are synthesized, and the prototype filters are then transformed to bandpass filters by lowpass to bandpass frequency mapping. By using immitance inverters ( J - or K -inverters), the bandpass filters can be realized by the same type of resonators. One design example is given to verify the theory ...

  8. Satellite soil moisture for advancing our understanding of earth system processes and climate change

    Science.gov (United States)

    Dorigo, Wouter; de Jeu, Richard

    2016-06-01

    Soil moisture products obtained from active and passive microwave satellites have reached maturity during the last decade (De Jeu and Dorigo, 2016): On the one hand, research algorithms that were initially applied to sensors designed for other purposes, e.g., for measuring wind speed (e.g. the Advanced Scatterometer (ASCAT)), sea ice, or atmospheric parameters (e.g. the TRMM Microwave Imager (TMI) and the Advanced Microwave Scanning Radiometer - Earth Observing System AMSR-E), have developed into fully operational products. On the other hand, dedicated soil moisture satellite missions were designed and launched by ESA (the Soil Moisture Ocean Salinity (SMOS) mission) and NASA (the Soil Moisture Active Passive (SMAP) mission).

  9. Integrated Advanced Microwave Sounding Unit-A (AMSU-A). Performance Verification Report: METSAT (S/N) AMSU-A1 Receiver Assemblies P/N 1356429-1 S/N F06 and P/N 1356409-1 S/N F06

    Science.gov (United States)

    1999-01-01

    This is the Performance Verification Report, METSAT (S/N 109) AMSU-A1 Receiver Assemblies, P/N 1356429-1 S/N F06 and P/N 1356409 S/N F06, for the Integrated Advanced Microwave Sounding Unit-A (AMSU-A).

  10. Microwave power engineering applications

    CERN Document Server

    Okress, Ernest C

    2013-01-01

    Microwave Power Engineering, Volume 2: Applications introduces the electronics technology of microwave power and its applications. This technology emphasizes microwave electronics for direct power utilization and transmission purposes. This volume presents the accomplishments with respect to components, systems, and applications and their prevailing limitations in the light of knowledge of the microwave power technology. The applications discussed include the microwave heating and other processes of materials, which utilize the magnetron predominantly. Other applications include microwave ioni

  11. The Moon as a photometric calibration standard for microwave sensors

    Science.gov (United States)

    Burgdorf, Martin; Buehler, Stefan A.; Lang, Theresa; Michel, Simon; Hans, Imke

    2016-08-01

    Instruments on satellites for Earth observation on polar orbits usually employ a two-point calibration technique, in which deep space and an onboard calibration target provide two reference flux levels. As the direction of the deep-space view is in general close to the celestial equator, the Moon sometimes moves through the field of view and introduces an unwelcome additional signal. One can take advantage of this intrusion, however, by using the Moon as a third flux standard, and this has actually been done for checking the lifetime stability of sensors operating at visible wavelengths. As the disk-integrated thermal emission of the Moon is less well known than its reflected sunlight, this concept can in the microwave range only be used for stability checks and intercalibration. An estimate of the frequency of appearances of the Moon in the deep-space view, a description of the limiting factors of the measurement accuracy and models of the Moon's brightness, and a discussion of the benefits from complementing the naturally occurring appearances of the Moon with dedicated spacecraft maneuvers show that it would be possible to detect photometric lifetime drifts of a few percent with just two measurements. The pointing accuracy is the most crucial factor for the value of this method. Planning such observations in advance would be particularly beneficial, because it allows observing the Moon at well-defined phase angles and putting it at the center of the field of view. A constant phase angle eliminates the need for a model of the Moon's brightness when checking the stability of an instrument. With increasing spatial resolution of future microwave sensors another question arises, viz. to what extent foreground emission from objects other than the Moon will contaminate the flux entering the deep-space view, which is supposed to originate exclusively in the cosmic microwave background. We conclude that even the brightest discreet sources have flux densities below the

  12. Passive Microwave Precipitation Detection Biases: Relationship to Environment

    Science.gov (United States)

    Viramontez, A.; Rapp, A. D.

    2015-12-01

    Accurate satellite precipitation estimates are essential for understanding the long-term variability in the global hydrologic cycle and for constraining global climate models. Spaceborne precipitation estimates depend heavily on passive microwave remote sensors due to the large spatial coverage and long record of observations available from such sensors; however, light precipitation is frequently undetected or underestimated by passive microwave rainfall retrievals. Observations from the CloudSat Profiling Radar (CPR) and the Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) provide a unique opportunity for long-term collocated precipitation measurements from passive microwave sensors and an active radar with sensitivity to very light precipitation that can be used to assess the precipitation detection biases. For this study, collocated measurements from AMSR-E and CloudSat during 2008 will be used to identify environments where AMSR-E underestimates precipitation. Environmental variables from the ECMWF Reanalysis (ERA-Interim) will be used to understand the characteristics of the large-scale and thermodynamic environments associated with AMSR-E precipitation biases. A preliminary comparison of CPR rain rates and AMSR-E Level-2B rain rates show a large fraction of rain missed by AMSR-E, with nearly 80% of missed light rain in regions with SSTs below 25°C. This is consistent with prior studies showing large detection biases in regions of large-scale subsidence. The relationship between precipitation biases and other factors such as 2 m air temperature, column water vapor, lower tropospheric stability, and vertical velocity will be explored.

  13. Microwave emissivity of freshwater ice, Part II: Modelling the Great Bear and Great Slave Lakes

    CERN Document Server

    Mills, Peter

    2012-01-01

    Lake ice within three Advanced Microwave Scanning Radiometer on EOS (AMSR-E) pixels over the Great Bear and Great Slave Lakes have been simulated with the Canadian Lake Ice Model (CLIMo). The resulting thicknesses and temperatures were fed to a radiative transfer-based ice emissivity model and compared to the satellite measurements at three frequencies---6.925 GHz, 10.65 GHz and 18.7 GHz. Excluding the melt season, the model was found to have strong predictive power, returning a correlation of 0.926 and a residual of 0.78 Kelvin at 18 GHz, vertical polarization. Discrepencies at melt season are thought to be caused by the presence of dirt in the snow cover which makes the microwave signature more like soil rather than ice. Except at 18 GHz, all results showed significant bias compared to measured values. Further work needs to be done to determine the source of this bias.

  14. Comparative evaluation of surface porosities in conventional heat polymerized acrylic resin cured by water bath and microwave energy with microwavable acrylic resin cured by microwave energy

    Directory of Open Access Journals (Sweden)

    Sunint Singh

    2013-01-01

    Full Text Available Background: Conventional heat cure poly methyl methacrylate (PMMA is the most commonly used denture base resin despite having some short comings. Lengthy polymerization time being one of them and in order to overcome this fact microwave curing method was recommended. Unavailability of specially designed microwavable acrylic resin made it unpopular. Therefore, in this study, conventional heat cure PMMA was polymerized by microwave energy. Aim and Objectives: This study was designed to evaluate the surface porosities in PMMA cured by conventional water bath and microwave energy and compare it with microwavable acrylic resin cured by microwave energy. Materials and Methods: Wax samples were obtained by pouring molten wax into a metal mold of 25 mm × 12 mm × 3 mm dimensions. These samples were divided into three groups namely C, CM, and M. Group C denotes conventional heat cure PMMA cured by water bath method, CM denotes conventional heat cure PMMA cured by microwave energy, M denotes specially designed microwavable acrylic denture base resin cured by microwave energy. After polymerization, each sample was scanned in three pre-marked areas for surface porosities using the optical microscope. As per the literature available, this instrument is being used for the first time to measure the porosity in acrylic resin. It is a reliable method of measuring area of surface pores. Portion of the sample being scanned is displayed on the computer and with the help of software area of each pore was measured and data were analyzed. Results: Conventional heat cure PMMA samples cured by microwave energy showed maximum porosities than the samples cured by conventional water bath method and microwavable acrylic resin cured by microwave energy. Higher percentage of porosities was statistically significant, but well within the range to be clinically acceptable. Conclusion: Within the limitations of this in-vitro study, conventional heat cure PMMA can be cured by

  15. CT scan

    Science.gov (United States)

    ... come from a CT scan. Some people have allergies to contrast dye. Let your doctor know if you have ... vein contains iodine. If you have an iodine allergy, a type of contrast may cause nausea or vomiting , sneezing , itching , or ...

  16. MRI Scans

    Science.gov (United States)

    Magnetic resonance imaging (MRI) uses a large magnet and radio waves to look at organs and structures inside your body. Health care professionals use MRI scans to diagnose a variety of conditions, from ...

  17. Statistical Analysis of the Correlation between Microwave Emission Anomalies and Seismic Activity Based on AMSR-E Satellite Data

    Science.gov (United States)

    qin, kai; Wu, Lixin; De Santis, Angelo; Zhang, Bin

    2016-04-01

    Pre-seismic thermal IR anomalies and ionosphere disturbances have been widely reported by using the Earth observation system (EOS). To investigate the possible physical mechanisms, a series of detecting experiments on rock loaded to fracturing were conducted. Some experiments studies have demonstrated that microwave radiation energy will increase under the loaded rock in specific frequency and the feature of radiation property can reflect the deformation process of rock fracture. This experimental result indicates the possibility that microwaves are emitted before earthquakes. Such microwaves signals are recently found to be detectable before some earthquake cases from the brightness temperature data obtained by the microwave-radiometer Advanced Microwave-Scanning Radiometer for the EOS (AMSR-E) aboard the satellite Aqua. This suggested that AMSR-E with vertical- and horizontal-polarization capability for six frequency bands (6.925, 10.65, 18.7, 23.8, 36.5, and 89.0 GHz) would be feasible to detect an earthquake which is associated with rock crash or plate slip. However, the statistical analysis of the correlation between satellite-observed microwave emission anomalies and seismic activity are firstly required. Here, we focus on the Kamchatka peninsula to carry out a statistical study, considering its high seismicity activity and the dense orbits covering of AMSR-E in high latitudes. 8-years (2003-2010) AMSR-E microwave brightness temperature data were used to reveal the spatio-temporal association between microwave emission anomalies and 17 earthquake events (M>5). Firstly, obvious spatial difference of microwave brightness temperatures between the seismic zone at the eastern side and the non-seismic zone the western side within the Kamchatka peninsula are found. Secondly, using both vertical- and horizontal-polarization to extract the temporal association, it is found that abnormal changes of microwave brightness temperatures appear generally 2 months before the

  18. Practical microwave electron devices

    CERN Document Server

    Meurant, Gerard

    2013-01-01

    Practical Microwave Electron Devices provides an understanding of microwave electron devices and their applications. All areas of microwave electron devices are covered. These include microwave solid-state devices, including popular microwave transistors and both passive and active diodes; quantum electron devices; thermionic devices (including relativistic thermionic devices); and ferrimagnetic electron devices. The design of each of these devices is discussed as well as their applications, including oscillation, amplification, switching, modulation, demodulation, and parametric interactions.

  19. Future Directions in the Microwave Cavity Search for Dark Matter Axions

    CERN Document Server

    Shokair, T M; Van Bibber, K A; Brubaker, B; Gurevich, Y V; Cahn, S B; Lamoreaux, S K; Anil, M A; Lehnert, K W; Mitchell, B K; Reed, A; Carosi, G

    2014-01-01

    The axion is a light pseudoscalar particle which suppresses CP-violating effects in strong interactions and also happens to be an excellent dark matter candidate. Axions constituting the dark matter halo of our galaxy may be detected by their resonant conversion to photons in a microwave cavity permeated by a magnetic field. The current generation of the microwave cavity experiment has demonstrated sensitivity to plausible axion models, and upgrades in progress should achieve the sensitivity required for a definitive search, at least for low mass axions. However, a comprehensive strategy for scanning the entire mass range, from 1-1000 $\\mu$eV, will require significant technological advances to maintain the needed sensitivity at higher frequencies. Such advances could include sub-quantum-limited amplifiers based on squeezed vacuum states, bolometers, and/or superconducting microwave cavities. The Axion Dark Matter eXperiment at High Frequencies (ADMX-HF) represents both a pathfinder for first data in the 20-10...

  20. Scanning system

    International Nuclear Information System (INIS)

    An improved transversally cutting radionuclide scanning system is described which can be used for medical diagnosis and medical treatment of men, particularly, for brain investingations. 99mTc43 is named as a radionuclide. The device described is more sensitive, and displays results in a shorter period of time than devices known until now. By means of laser emitting diodes a continuous transmission and collection of signals is obtained, due to a rotating picture framework of offset and meshing detectors surrounding completely the scanning field around a single rotation axis - coaxialy with the axis of the head. Signals are processed and displayed by a connected computer. Description in detail, 7 figures. (UWI)

  1. Lung scans and malignancy

    International Nuclear Information System (INIS)

    An experience of pulmonary isotope scanning carried out with mercury 197 labelled mercury chloride and acetate, cobalt 57-labelled bleomycin, and Cu67 and Cu64 labelled copper citrate was presented. The scans were carried out with various isotopes supplied by the French Atomic Energy Authority, and gave comparable results, which may be summarised as follows: increased uptake in more than 90% of cases of carcinoma, absent uptake in all cases of benign tumour, frequent increased uptake in acute or advanced inflammatory lesions, absence of uptake, very commonly, in tuberculoma and chronic lesions with scar formation. Radio-isotope scan using Cu67 labelled copper citrate permitted discrimination of malignant tumours (increased fixation which showed up best at the 24th hour) from inflammatory lesions (increased fixation which was reduced on the 24th hour). The positive or negative character of the fixation in a given lesions remains the same, whatever the isotope used in our experience

  2. Scan Statistics

    CERN Document Server

    Glaz, Joseph

    2009-01-01

    Suitable for graduate students and researchers in applied probability and statistics, as well as for scientists in biology, computer science, pharmaceutical science and medicine, this title brings together a collection of chapters illustrating the depth and diversity of theory, methods and applications in the area of scan statistics.

  3. The new method of electronic scanning

    OpenAIRE

    Khludneva, A.; Mikhailov, M.; Paslyon, V.

    2009-01-01

    We investigate the possibility of using the reversing mediums in the antenna engineering that gives us the ability to improve characteristics of the antenna systems; particularly we can receive the adjusted form and width of the directional diagram in the microwave range and we can also command the directional diagram while scanning within the adjusted rule.

  4. Microwave combustion and sintering without isostatic pressure

    International Nuclear Information System (INIS)

    In recent years interest has grown rapidly in the application of microwave energy to the processing of ceramics, composites, polymers, and other materials. Advances in the understanding of microwave/materials interactions will facilitate the production of new ceramic materials with superior mechanical properties. One application of particular interest is the use of microwave energy for the mobilization of uranium for subsequent redeposition. Phase III (FY98) will focus on the microwave assisted chemical vapor infiltration tests for mobilization and redeposition of radioactive species in the mixed sludge waste. Uranium hexachloride and uranium (IV) borohydride are volatile compounds for which the chemical vapor infiltration procedure might be developed for the separation of uranium. Microwave heating characterized by an inverse temperature profile within a preformed ceramic matrix will be utilized for CVI using a carrier gas. Matrix deposition is expected to commence from the inside of the sample where the highest temperature is present. The preform matrix materials, which include aluminosilicate based ceramics and silicon carbide based ceramics, are all amenable to extreme volume reduction, densification, and vitrification. Important parameters of microwave sintering such as frequency, power requirement, soaking temperature, and holding time will be investigated to optimize process conditions for the volatilization of uranyl species using a reactive carrier gas in a microwave chamber

  5. The Future of Microwave Background Physics

    CERN Document Server

    Kosowsky, A

    2003-01-01

    The cosmic microwave background is now fulfilling its promise of determining the basic cosmological parameters describing our Universe. Future study of the microwave background will mostly be directed towards two basic questions: a complete characterization of the initial perturbations, and probes of the nonlinear evolution of structure in the Universe. The basic scientific issues in both of these areas are reviewed here, along with possibilities for addressing them with further microwave background measurements at higher sensitivities and smaller angular scales. The proposed ACT experiment, which will map 200 square degrees of sky at arcminute resolution and micro-Kelvin sensitivity in three microwave frequency bands, is briefly described as an example of rapidly advancing experimental technique.

  6. Microwave Breast Imaging Techniques

    DEFF Research Database (Denmark)

    Zhurbenko, Vitaliy; Rubæk, Tonny

    2010-01-01

    This paper outlines the applicability of microwave radiation for breast cancer detection. Microwave imaging systems are categorized based on their hardware architecture. The advantages and disadvantages of various imaging techniques are discussed. The fundamental tradeoffs are indicated between...

  7. NESDIS Microwave Integrated Retrieval System (MIRS) ATMS Sounding Products

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains temperature and humidity profiles from the NOAA Microwave Integrated Retrieval System (MIRS) using sensor data from the Advanced Technology...

  8. Microwave Enhanced Freeze Drying of Solid Waste Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The development of advanced methods for Microwave Enhanced Freeze Drying of Solid Waste (MEFDSW) is proposed. Methods for the recovery of relatively pure water as a...

  9. Microwave emissivity of fresh water ice--Lake ice and Antarctic ice pack--Radiative transfer simulations versus satellite radiances

    CERN Document Server

    Mills, Peter

    2012-01-01

    Microwave emissivity models of sea ice are poorly validated empirically. Typical validation studies involve using averaged or stereotyped profiles of ice parameters against averaged radiance measurements. Measurement sites are rarely matched and even less often point-by-point. Because of saline content, complex permittivity of sea ice is highly variable and difficult to predict. Therefore, to check the validity of a typical, plane-parallel, radiative-transfer-based ice emissivity model, we apply it to fresh water ice instead of salt-water ice. Radiance simulations for lake ice are compared with measurements over Lake Superior from the Advanced Microwave Scanning Radiometer on EOS (AMSR-E). AMSR-E measurements are also collected over Antarctic icepack. For each pixel, a thermodynamic model is driven by four years of European Center for Medium Range Weather Forecasts (ECMWF) reanalysis data and the resulting temperature profiles used to drive the emissivity model. The results suggest that the relatively simple ...

  10. Receivers for the Microwave Radiometer on Juno

    Science.gov (United States)

    Maiwald, F.; Russell, D.; Dawson, D.; Hatch, W.; Brown, S.; Oswald, J.; Janssen, M.

    2009-01-01

    Six receivers for the MicroWave Radiometer (MWR) are currently under development at JPL. These receivers cover a frequency range of 0.6 to 22 GHz in approximately octave steps, with 4 % bandwidth. For calibration and diagnosis three noise diodes and a Dicke switch are integrated into each receiver. Each receiver is connected to its own antenna which is mounted with its bore sights perpendicular to the spin axis of the spacecraft. As the spacecraft spins at 2 RPM, the antenna field of view scans Jupiter's atmosphere from limb to nadir to limb, measuring microwave emission down to 1000-bar.

  11. Microwave quantum optics with an artificial atom in one-dimensional open space

    OpenAIRE

    Hoi, Io-Chun; Wilson, C. M.; Johansson, Goran; Lindkvist, Joel; Peropadre, Borja; Palomaki, Tauno; Delsing, Per

    2013-01-01

    We address recent advances in microwave quantum optics with artificial atoms in one-dimensional (1D) open space. This field relies on the fact that the coupling between a superconducting artificial atom and propagating microwave photons in a 1D open transmission line can be made strong enough to observe quantum coherent effects, without using any cavity to confine the microwave photons. We investigate the scattering properties in such a system with resonant coherent microwaves. We observe the...

  12. Evaluation of the extracellular polymeric substances by confocal laser scanning microscopy in conventional activated sludge and advanced membrane bioreactors treating hospital wastewater.

    Science.gov (United States)

    Alrhmoun, Mousaab; Carrion, Claire; Casellas, Magali; Dagot, Christophe

    2014-01-01

    Confocal laser scanning microscopy (CLSM) combined with fluorescent viability indicators, was used in this study to investigate the impact of hospital wastewaters on floc structure and composition. In this work, three pilot-scale projects, two membrane bioreactors (MBRs) with a submerged or external membrane bioreactor and a conventional activated sludge, were installed and operated for 65 days. They were fed with an influent sampled directly from the hospital drainage system, which contained micropollutant concentrations ranging from ng/L to mg/L. Samples of flocs were observed using CLSM to characterize the extracellular polymeric substances (EPS) stained with concanavalin A-tetra methylrhodamine and fluorescein isothiocyanate solution and combined with a fluorescent viability indicator (Baclight(®) Bacterial Viability Kit, Molecular Probes), allowing visualization of isolated stained cells in the three-dimensional structure of flocs (damaged or not). The results of CLSM of the sludge composition were compared with classical biochemical analysis of EPS made through a thermal extraction method. The results showed a good relation between these analyses and the statistical treatment of microscopic pictures. PMID:24901624

  13. X-ray fluorescence (conventional and 3D) and scanning electron microscopy for the investigation of Portuguese polychrome glazed ceramics: Advances in the knowledge of the manufacturing techniques

    International Nuclear Information System (INIS)

    This work shows the first analytical results obtained by X-Ray Fluorescence (XRF) (conventional and 3D) and Scanning Electron Microscopy with Energy Dispersive System (SEM-EDS) on original Portuguese ceramic pieces produced between the 16th and 18th centuries in Coimbra and Lisbon. Experts distinguished these productions based only on the color, texture and brightness, which originates mislabeling in some cases. Thanks to lateral and spatial resolution in the micrometer regime, the results obtained with μ-XRF were essential in determining the glaze and pigment thicknesses by monitoring the profile of the most abundant element in each 'layer'. Furthermore, the dissemination of these elements throughout the glaze is different depending on the glaze composition, firing temperature and on the pigment itself. Hence, the crucial point of this investigation was to analyze and understand the interfaces color/glaze and glaze/ceramic support. Together with the XRF results, images captured by SEM and the corresponding semi-quantitative EDS data revealed different manufacturing processes used by the two production centers. Different capture modes were suitable to distinguish different crystals from the minerals that confer the color of the pigments used and to enhance the fact that some of them are very well spread through the glassy matrix, sustaining the theory of an evolved and careful procedure in the manufacturing process of the glaze.

  14. LASER SCANNING CYTOMETRIC DNA ANALYSES AND EXPRE- SSION OF P53 PROTEIN,KI67 AND BCL-X IN EARLY AND ADVANCED CARCINOMAS OF THE VOCAL CORD

    Institute of Scientific and Technical Information of China (English)

    林梅绥; 金嘉平; 陈颖; 花井淳

    2003-01-01

    Objective To study DNA ploidy and genetic changes in the different stages of neoplastic growth in the vocal cord, as well as their biological behavior, for further recognition of the lesions of carcinoma in situ and early carcinoma. Methods 18 tumor lesions of the vocal cord were DNA analyzed by laser scanning cytometry and followed up, and 62 lesions were immunohistochemically investigated for p53, Ki67 and Bcl-X, and with main observation on carcinomas in situ (CISs) and early microinvasive carcinomas (EMICs) which were compared with invasive carcinomas and polyps. Results DNA analysis showed that almost all the CISs and EMICs were diploidy, while 90% invasive carcinomas were aneuploidy. Follow-up data displayed that no one died of the tumor in CIS and EMIC, as well as in the patients with diploidy tumor, and all the patients died of the tumors were with anueploidy tumor. Immunohistochemically, 86% of CIS and EMIC and 91% of invasive carcinoma expressed p53 protein, and the positivities for Ki67 in them were respectively 29% and 27%, which were very significantly different from those of polyps of the vocal cord(P<0. 001). In contrast, expression of Bcl-X were decreasing from benign to malignant lesions, and it was lowest in the invasive carcinomas, significantly different from that of polyp(P=0. 002). Conclusion The present study showed that there were differences of DNA ploidy and genetic expressions among benign lesions, CISs and EMICs, and invasive carcinomas of the vocal cord, indicating that they might be different in biological entities. CIS of the vocal cord could be considered as a borderline lesion, and is better to receive conservative treatment. Moreover, p53 protein determination combined with Ki67 would be helpful in diagnosis of the carcinomas of the vocal cord.

  15. Thyroid Scan and Uptake

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Thyroid Scan and Uptake Thyroid scan and uptake uses ... the Thyroid Scan and Uptake? What is a Thyroid Scan and Uptake? A thyroid scan is a ...

  16. Pelvic CT scan

    Science.gov (United States)

    ... axial tomography scan - pelvis; Computed tomography scan - pelvis; CT scan - pelvis ... Risks of CT scans include: Being exposed to radiation Allergic reaction to contrast dye CT scans do expose you to more radiation ...

  17. Cervical spine CT scan

    Science.gov (United States)

    ... cervical spine; Computed tomography scan of cervical spine; CT scan of cervical spine; Neck CT scan ... Risks of CT scans include: Being exposed to radiation Allergic reaction to contrast dye CT scans expose you to more radiation than ...

  18. Sinus CT scan

    Science.gov (United States)

    ... axial tomography scan - sinus; Computed tomography scan - sinus; CT scan - sinus ... Risks of a CT scan includes: Being exposed to radiation Allergic reaction to contrast dye CT scans expose you to more radiation than regular ...

  19. Measurements of the frontal and prefrontal lobe volumes by three dimensional magnetic resonance imaging scan. III. Analysis of sex differences with advanced age

    Energy Technology Data Exchange (ETDEWEB)

    Kanemura, Hideaki; Aihara, Masao; Nakazawa, Shinpei [Yamanashi Medical Univ., Tamaho (Japan)

    2002-09-01

    To determine whether there is sex difference in the growth of the frontal and prefrontal lobes, we quantitatively measured the volume of these lobes by three dimensional (3-D) MRI in healthy 12 males (5 months to 39 years) and six females (1 year 11 months to 27 years). The left and right lobes were studied separately. The 3-D MRI data were acquired by the fast spoiled gradient recalled (SPGR) sequence using a 1.5 T MR imager. The frontal and prefrontal lobe volumes were measured by the volume measurement function of the Workstation. In males, the left to right ratio (L/R ratio) of the frontal and prefrontal lobes increased with age. On the contrary, in females, L/R ratio of the frontal and prefrontal lobes showed no significant change with advancing age. These results highlighted sex-specific maturational changes of the frontal and prefrontal lobes and suggested that quantitative data on the frontal and prefrontal lobe are important in interpreting brain abnormalities in children with developmental disorders. (author)

  20. Measurements of the frontal and prefrontal lobe volumes by three dimensional magnetic resonance imaging scan. III. Analysis of sex differences with advanced age

    International Nuclear Information System (INIS)

    To determine whether there is sex difference in the growth of the frontal and prefrontal lobes, we quantitatively measured the volume of these lobes by three dimensional (3-D) MRI in healthy 12 males (5 months to 39 years) and six females (1 year 11 months to 27 years). The left and right lobes were studied separately. The 3-D MRI data were acquired by the fast spoiled gradient recalled (SPGR) sequence using a 1.5 T MR imager. The frontal and prefrontal lobe volumes were measured by the volume measurement function of the Workstation. In males, the left to right ratio (L/R ratio) of the frontal and prefrontal lobes increased with age. On the contrary, in females, L/R ratio of the frontal and prefrontal lobes showed no significant change with advancing age. These results highlighted sex-specific maturational changes of the frontal and prefrontal lobes and suggested that quantitative data on the frontal and prefrontal lobe are important in interpreting brain abnormalities in children with developmental disorders. (author)

  1. Impact of ice temperature on microwave emissivity of thin newly formed sea ice

    Science.gov (United States)

    Hwang, Byong Jun; Ehn, Jens K.; Barber, David G.

    2008-02-01

    This study examines the impact of ice temperature on microwave emissivity over thin, newly formed sea ice at 6, 19, and 37 GHz during October 2003 in the southern Beaufort Sea, where the physical properties of newly formed sea ice were coincidently measured with microwave emissions. Six ice stations with distinct properties were selected and divided according to ice surface temperature into warm (above -3°C) or cold (below -3°C) stations. The warm stations had a lower emissivity at the vertical polarization by 0.1 than the cold stations and a corresponding difference in brine volume and dielectric properties. Significant correlations were observed between brine volume and ice emissivity (R2 = 0.8, p value emissivity between warm and cold stations. The results suggest that the temperature of thin bare ice could be the critical factor in determining ice emissivity near the melting point (about -2°C). Furthermore, a slight decrease in ice temperature (i.e., from -2° to -5°C) significantly reduces the brine volume, thus resulting in high ice emissivity. Finally, we demonstrate the potential of newly formed ice to cause errors in estimating sea ice concentrations using Advanced Microwave Scanning Radiometer-E data.

  2. Microwave Regenerable Air Purification Device

    Science.gov (United States)

    Atwater, James E.; Holtsnider, John T.; Wheeler, Richard R., Jr.

    1996-01-01

    The feasibility of using microwave power to thermally regenerate sorbents loaded with water vapor, CO2, and organic contaminants has been rigorously demonstrated. Sorbents challenged with air containing 0.5% CO2, 300 ppm acetone, 50 ppm trichloroethylene, and saturated with water vapor have been regenerated, singly and in combination. Microwave transmission, reflection, and phase shift has also been determined for a variety of sorbents over the frequency range between 1.3-2.7 GHz. This innovative technology offers the potential for significant energy savings in comparison to current resistive heating methods because energy is absorbed directly by the material to be heated. Conductive, convective and radiative losses are minimized. Extremely rapid heating is also possible, i.e., 1400 C in less than 60 seconds. Microwave powered thermal desorption is directly applicable to the needs of Advance Life Support in general, and of EVA in particular. Additionally, the applicability of two specific commercial applications arising from this technology have been demonstrated: the recovery for re-use of acetone (and similar solvents) from industrial waste streams using a carbon based molecular sieve; and the separation and destruction of trichloroethylene using ZSM-5 synthetic zeolite catalyst, a predominant halocarbon environmental contaminant. Based upon these results, Phase II development is strongly recommended.

  3. Microstructure Analysis of Microwave Sintered Ferrous PM Alloys

    Institute of Scientific and Technical Information of China (English)

    PENG Yuandong; YI Jianhong; LUO Shudong; GUO Yingli; LI Liya

    2009-01-01

    The properties and microstructure of microwave and conventional sinteredFe-2Cu-0.6C powder metallurgy (PM) alloys were investigated. The experimental results show that microwave sintered alloy has the better properties (sintered density 7.20 g/cm3, Rockwell hardness 75HRB, tensile strength 413.90 Mpa and elongation 6.0%), compared with the conventional sintered counterpart. Detailed analyses by using optical microscopy and scanning electron microscopy (SEM)reveal that microwave sintered sample has finer microstructure with small, rounded and uniformly distributed pores, and also demonstrate the presence of more flaky and granular pearlite in the mi-crowave sintered body, both of which account for the property improvement. SEM images on the fracture morphology indicate that a mixed mode containing ductile and brittle fracture is presented in microwave sintered alloy, in contrast with the brittle fracture in conventional sintered counterpart.

  4. Monitoring drought for grassland and cropland using multi-sensor microwave remote sensing data

    Science.gov (United States)

    Zhang, A.; Jia, G.

    2012-12-01

    Remote sensing drought indices derived from optical and infrared bands have been successfully used in monitoring drought throughout the world; however the application of microwave remote sensing sensor in drought monitoring has not been thoroughly investigated. In this study, we propose a microwave remote sensing drought index, the Microwave Integrated Drought Index (MIDI), especially for short-term drought monitoring over northern China. The index combined three variables: the Tropical Rainfall Measuring Mission (TRMM) precipitation, land surface temperature (LST) and soil moisture (SM) obtained by the Vrije Universiteit Amsterdam and NASA Goddard Space Flight Center (VUA-NASA) from the Advanced Microwave Scanning Radiometer (AMSR-E) on-board Aqua satellite. The microwave remotely sensed variables were linearly scaled from 0 to 1 for each pixel based on absolute minimum and maximum values for each variable over time, in order to discriminate the weather-related component from the ecosystem component. The microwave indices were evaluated with the Standardized Precipitation Index (SPI), an in-situ meteorological data based drought index. Pearson correlation analyses were performed between the remotely sensed drought indices values and different time scale SPI values for the growing season from 2003 to 2010 to assess the capability of remotely sensed drought indices in monitoring drought over three different climate regions in northern China. There was significant spatial variability in the correlations between remote sensing drought indices and SPI, generally, the Precipitation Condition Index (PCI) showed the highest correlation with 1-month SPI (r around 0.70) whether compared to remote sensing drought indices or different time scale SPI; while correlations between Soil Moisture Condition Index (SMCI), Land Surface Temperature (TCI) and SPI exhibited different trends among three climate regions. The MIDI with proper weights of three components nearly possessed the

  5. High-resolution near-field measurements of microwave circuits

    OpenAIRE

    SHVETS, IGOR; KANTOR, ROMAN

    2004-01-01

    PUBLISHED In this paper we report on measurements of electric field intensities of microwave field above surface of microwave circuits using miniaturized coaxial antennas. During the scanning process the antenna is driven at various distances above the sample surface according to topographic data acquired prior to the field measurement. A position/signal difference method is used to increase the spatial resolution of the antenna to about 20 jm ( A/104) - one order of magnitude ...

  6. Microwave drying of radwaste

    International Nuclear Information System (INIS)

    This paper briefly discusses how the microwave investigation began, what the investigators did and what the initial results indicate. Initial scoping tests using a 450 watt Sanyo microwave oven followed by experiments conducted with a 2 1/2 kilowatt microwave unit showed that resins could be dried without decomposing when temperature was kept below 2500F, and that volume reduction of at least two was possible. These tests show that microwave drying is easy and cost effective. Future plans are to put together a 30 kilowatt microwave unit which will be large enough to handle 5000 cubic feet of resin a year operating at about 60% capacity factor. Temperature measurements will be made with a probe. The unit will consist of condensers, water cooled stirrers, microwave power supply and engineering tanks which will cost anywhere from $$350,000 to $500,000

  7. Prognostic role of metabolic parameters of 18F-FDG PET-CT scan performed during radiation therapy in locally advanced head and neck squamous cell carcinoma

    International Nuclear Information System (INIS)

    To evaluate the prognostic value of 18F-FDG PET-CT performed in the third week (iPET) of definitive radiation therapy (RT) in patients with newly diagnosed locally advanced mucosal primary head and neck squamous-cell-carcinoma (MPHNSCC). Seventy-two patients with MPHNSCC treated with radical RT underwent staging PET-CT and iPET. The maximum standardised uptake value (SUVmax), metabolic tumour volume (MTV) and total lesional glycolysis (TLG) of primary tumour (PT) and index node (IN) [defined as lymph node(s) with highest TLG] were analysed, and results were correlated with loco-regional recurrence-free survival (LRFS), disease-free survival (DFS), metastatic failure-free survival(MFFS) and overall survival (OS), using Kaplan-Meier analysis. Optimal cutoffs (OC) were derived from receiver operating characteristic curves: SUVmax-PT = 4.25 g/mL, MTVPT = 3.3 cm3, TLGPT = 9.4 g, for PT, and SUVmax-IN = 4.05 g/mL, MTVIN = 1.85 cm3 and TLGIN = 7.95 g for IN. Low metabolic values in iPET for PT below OC were associated with statistically significant better LRFS and DFS. TLG was the best predictor of outcome with 2-year LRFS of 92.7 % vs. 71.1 % [p = 0.005, compared with SUVmax (p = 0.03) and MTV (p = 0.022)], DFS of 85.9 % vs. 60.8 % [p = 0.005, compared with SUVmax (p = 0.025) and MTV (p = 0.018)], MFFS of 85.9 % vs. 83.7 % [p = 0.488, compared with SUVmax (p = 0.52) and MTV (p = 0.436)], and OS of 81.1 % vs. 75.0 % [p = 0.279, compared with SUVmax (p = 0.345) and MTV (p = 0.512)]. There were no significant associations between the percentage reduction of primary tumour metabolic parameters and outcomes. In patients with nodal disease, metabolic parameters below OC (for both PT and IN) were significantly associated with all oncological outcomes, while TLG was again the best predictor: LRFS of 84.0 % vs. 55.3 % (p = 0.017), DFS of 79.4 % vs. 38.6 % (p = 0.001), MFFS 86.4 % vs. 68.2 % (p = 0.034) and OS 80.4 % vs. 55.7 % (p = 0.045). The metabolic parameters of iPET can be

  8. Prognostic role of metabolic parameters of {sup 18}F-FDG PET-CT scan performed during radiation therapy in locally advanced head and neck squamous cell carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Min, Myo; Forstner, Dion [Liverpool Hospital, Cancer Therapy Centre, Liverpool, NSW (Australia); University of New South Wales, Sydney, NSW (Australia); Ingham Institute of Applied Medical Research, Liverpool, NSW (Australia); Lin, Peter; Shon, Ivan Ho; Lin, Michael [University of New South Wales, Sydney, NSW (Australia); Liverpool Hospital, Department of Nuclear Medicine and Positron Emission Tomography, Liverpool, NSW (Australia); University of Western Sydney, Sydney, NSW (Australia); Lee, Mark T. [Liverpool Hospital, Cancer Therapy Centre, Liverpool, NSW (Australia); University of New South Wales, Sydney, NSW (Australia); Bray, Victoria; Fowler, Allan [Liverpool Hospital, Cancer Therapy Centre, Liverpool, NSW (Australia); Chicco, Andrew [Liverpool Hospital, Department of Nuclear Medicine and Positron Emission Tomography, Liverpool, NSW (Australia); Tieu, Minh Thi [Calvary Mater Newcastle, Department of Radiation Oncology, Newcastle, NSW (Australia); University of Newcastle, Newcastle, NSW (Australia)

    2015-12-15

    To evaluate the prognostic value of {sup 18}F-FDG PET-CT performed in the third week (iPET) of definitive radiation therapy (RT) in patients with newly diagnosed locally advanced mucosal primary head and neck squamous-cell-carcinoma (MPHNSCC). Seventy-two patients with MPHNSCC treated with radical RT underwent staging PET-CT and iPET. The maximum standardised uptake value (SUV{sub max}), metabolic tumour volume (MTV) and total lesional glycolysis (TLG) of primary tumour (PT) and index node (IN) [defined as lymph node(s) with highest TLG] were analysed, and results were correlated with loco-regional recurrence-free survival (LRFS), disease-free survival (DFS), metastatic failure-free survival(MFFS) and overall survival (OS), using Kaplan-Meier analysis. Optimal cutoffs (OC) were derived from receiver operating characteristic curves: SUV{sub max-PT} = 4.25 g/mL, MTV{sub PT} = 3.3 cm{sup 3}, TLG{sub PT} = 9.4 g, for PT, and SUV{sub max-IN} = 4.05 g/mL, MTV{sub IN} = 1.85 cm{sup 3} and TLG{sub IN} = 7.95 g for IN. Low metabolic values in iPET for PT below OC were associated with statistically significant better LRFS and DFS. TLG was the best predictor of outcome with 2-year LRFS of 92.7 % vs. 71.1 % [p = 0.005, compared with SUV{sub max} (p = 0.03) and MTV (p = 0.022)], DFS of 85.9 % vs. 60.8 % [p = 0.005, compared with SUV{sub max} (p = 0.025) and MTV (p = 0.018)], MFFS of 85.9 % vs. 83.7 % [p = 0.488, compared with SUV{sub max} (p = 0.52) and MTV (p = 0.436)], and OS of 81.1 % vs. 75.0 % [p = 0.279, compared with SUV{sub max} (p = 0.345) and MTV (p = 0.512)]. There were no significant associations between the percentage reduction of primary tumour metabolic parameters and outcomes. In patients with nodal disease, metabolic parameters below OC (for both PT and IN) were significantly associated with all oncological outcomes, while TLG was again the best predictor: LRFS of 84.0 % vs. 55.3 % (p = 0.017), DFS of 79.4 % vs. 38.6 % (p = 0.001), MFFS 86.4 % vs. 68.2 % (p = 0

  9. Nonlinear Integrated Microwave Photonics

    OpenAIRE

    Marpaung, David; Eggleton, Benjamin J.

    2013-01-01

    Harnessing nonlinear optical effects in a photonic chip scale has been proven useful for a number of key applications in optical communications. Microwave photonics can also benefit from the adoption of such a technology, creating a new concept of nonlinear integrated microwave photonics. Here, we discuss the potential of on-chip nonlinear processing towards the creation of robust and multifunctional microwave photonic (MWP) processors. We also highlight key recent results in the field, inclu...

  10. Microwave and RF engineering

    CERN Document Server

    Sorrentino, Roberto

    2010-01-01

    An essential text for both students and professionals, combining detailed theory with clear practical guidance This outstanding book explores a large spectrum of topics within microwave and radio frequency (RF) engineering, encompassing electromagnetic theory, microwave circuits and components. It provides thorough descriptions of the most common microwave test instruments and advises on semiconductor device modelling. With examples taken from the authors' own experience, this book also covers:network and signal theory;electronic technology with guided electromagnetic pr

  11. Passive microwave remote sensing of soil moisture

    International Nuclear Information System (INIS)

    Microwave remote sensing provides a unique capability for direct observation of soil moisture. Remote measurements from space afford the possibility of obtaining frequent, global sampling of soil moisture over a large fraction of the Earth's land surface. Microwave measurements have the benefit of being largely unaffected by cloud cover and variable surface solar illumination, but accurate soil moisture estimates are limited to regions that have either bare soil or low to moderate amounts of vegetation cover. A particular advantage of passive microwave sensors is that in the absence of significant vegetation cover soil moisture is the dominant effect on the received signal. The spatial resolutions of passive microwave soil moisture sensors currently considered for space operation are in the range 10–20 km. The most useful frequency range for soil moisture sensing is 1–5 GHz. System design considerations include optimum choice of frequencies, polarizations, and scanning configurations, based on trade-offs between requirements for high vegetation penetration capability, freedom from electromagnetic interference, manageable antenna size and complexity, and the requirement that a sufficient number of information channels be available to correct for perturbing geophysical effects. This paper outlines the basic principles of the passive microwave technique for soil moisture sensing, and reviews briefly the status of current retrieval methods. Particularly promising are methods for optimally assimilating passive microwave data into hydrologic models. Further studies are needed to investigate the effects on microwave observations of within-footprint spatial heterogeneity of vegetation cover and subsurface soil characteristics, and to assess the limitations imposed by heterogeneity on the retrievability of large-scale soil moisture information from remote observations

  12. Microwave-assisted hydrothermal synthesis of lead zirconate fine powders

    Directory of Open Access Journals (Sweden)

    Apinpus Rujiwatra

    2011-01-01

    Full Text Available A rapid synthesis of lead zirconate fine powders by microwave-assisted hydrothermal technique is reported. The influences of type of lead precursor, concentration of potassium hydroxide mineraliser, applied microwave power and irradiation time are described. The synthesised powders were characterised by powder X-ray diffraction, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopic microanalysis and light scattering technique. The merits of the microwave application in reducing reaction time and improving particle mono-dispersion and size uniformity as well as the drawbacks, viz. low purity of the desired phase and increasing demand of mineraliser, are discussed in relation to conventional heating method.

  13. Mathematical simulation of microwave scattering in the medium with characteristic features of biological tissues and prospectives of microwave tomography

    OpenAIRE

    Sukharevsky, Oleg I.; Lesovoy, V. N.; Zamiatin, V. L.; Gorelyshev, S. A.; Podorozhnyak, A. A.

    1995-01-01

    Computer aided tomography is used today in many areas of science and technology, such as biology, medicine, geophysics, plasma physics, non-destructive introscopy and state control of heat-radiation elements at nuclear power plants, cartography, etc. Microwave imaging is one of the prospective methods of tomography. It is based on the retrieval of dielectric properties of a solid body irradiated by an electromagnetic wave of microwave band. Scanning the scientific and technical literature, in...

  14. The influence of microwave irradiation on rocks for microwave-assisted underground excavation

    Directory of Open Access Journals (Sweden)

    Ferri Hassani

    2016-02-01

    Full Text Available Demand is growing for explosive-free rock breakage systems for civil and mining engineering, and space industry applications. This paper highlights the work being undertaken in the Geomechanics Laboratory of McGill University to make a real application of microwave-assisted mechanical rock breakage to full-face tunneling machines and drilling. Comprehensive laboratory tests investigated the effect of microwave radiation on temperature profiles and strength reduction in hard rocks (norite, granite, and basalt for a range of exposure times and microwave power levels. The heating rate on the surface of the rock specimens linearly decreased with distance between the sample and the microwave antenna, regardless of microwave power level and exposure time. Tensile and uniaxial compressive strengths were reduced with increasing exposure time and power level. Scanning electron micrographs (SEMs highlighted fracture development in treated basalt. It was concluded that the microwave power level has a strong positive influence on the amount of heat damage induced to the rock surface. Numerical simulations of electric field intensity and wave propagation conducted with COMSOL Multiphysics® software generated temperature profiles that were in close agreement with experimental results.

  15. Artificial color perception using microwaves

    CERN Document Server

    Choudhury, Debesh

    2013-01-01

    We report the feasibility of artificial color perception under microwave illumination using a standard microwave source and an antenna. We have sensed transmitted microwave power through color objects and have distinguished the colors by analyzing the sensed transmitted power. Experiments are carried out using a Gunn diode as the microwave source, some colored liquids as the objects and a microwave diode as the detector. Results are presented which open up an unusual but new way of perceiving colors using microwaves.

  16. Broadband antenna with frequency scanning

    Directory of Open Access Journals (Sweden)

    A. A. Shekaturin

    2014-06-01

    Full Text Available Relevance of this study. The main advantage of frequency scanning is simplicity of implementation. At this point, multifunctional usage of microwave modules is an urgent task, as well as their maximum simpler and cheaper. Antenna design and operation. The study is aimed at providing electric antenna with frequency scanning. It was based on the log-periodic antenna due to its wideband and negotiation capability over the entire operating frequency range. For this distribution line is bent in an arc of a circle in a plane blade while vibrators are arranged along the radius. Computer modeling of antennas with frequency scanning. Modeled with a non-mechanical motion antenna beam emitters representing system for receiving a radio frequency signal on mobile objects calculated for 1.8 GHz ... 4.2 GHz. The simulation was performed in a software environment for numerical modeling of electromagnetic «Feko 5.5». Analysis of the interaction of radiation is based on the method of moments. Findings. The result of this work is to propose a new design of the antenna with a frequency scanning method as agreed in a wide frequency range. In the studied technical solution provided by the rotation of NAM in the frequency range, and the matching of the antenna to the feed line is maintained. Application of this type of antennas on the proposed technical solution in communication systems will improve the communication reliability by maintaining coordination in the frequency range

  17. Abdominal CT scan

    Science.gov (United States)

    Computed tomography scan - abdomen; CT scan - abdomen; CAT scan - abdomen; CT abdomen and pelvis ... An abdominal CT scan makes detailed pictures of the structures inside your belly (abdomen) very quickly. This test may be used to ...

  18. Shoulder CT scan

    Science.gov (United States)

    CAT scan - shoulder; Computed axial tomography scan - shoulder; Computed tomography scan - shoulder; CT scan - shoulder ... stopping.) A computer creates separate images of the shoulder area. These are called slices. These images can ...

  19. Advanced grating laser designs for microwave generation

    OpenAIRE

    Ibsen, M.; Ronnekleiv, E.; Hadeler, O.; Cowle, G.J.; Laming, R.I.; Zervas, M. N.

    2000-01-01

    Fibre Bragg gratings have over a relatively short evolutionary process matured from prototypes in laboratory environments to commercial products in real world applications. This short process has been driven by a combined effort from many research groups throughout the scientific communities in the development and refinement of grating fabrication techniques as well as a number of potential applications. One field that has attracted attention from many obvious applications of Bragg gratings i...

  20. Advanced Optical Processing of Microwave Signals

    Directory of Open Access Journals (Sweden)

    Miguel V. Andrés

    2005-06-01

    Full Text Available The authors present a review on the recent approaches proposed to implement transversal RF filters. Different tunable transversal filters consisting of wavelength tunable optical taps and those employing the tunability of dispersive devices are presented showing their high-performance characteristics. A comprehensive review of the fundamentals and a discussion on the main limitation of these structures are also included.

  1. The Cosmic Microwave Background

    OpenAIRE

    Silk, Joseph

    2001-01-01

    This set of lectures provides an overview of the basic theory and phenomenology of the cosmic microwave background. Topics include a brief historical review; the physics of temperature and polarization fluctuations; acoustic oscillations of the primordial plasma; the space of inflationary cosmological models; current and potential constraints on these models from the microwave background; and constraints on inflation.

  2. Microwave Glass Melting Technology

    Czech Academy of Sciences Publication Activity Database

    Hájek, Milan

    Tokyo, 2001, s. 11-14. [Conference on Application of Microwave Energy in Industry. Tokyo (JP), 30.07.2001-03.08.2001] R&D Projects: GA AV ČR IBS4072003 Institutional research plan: CEZ:AV0Z4072921 Keywords : microwave * glass melting technology * application Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  3. Microwave radiation hazards around large microwave antenna.

    Science.gov (United States)

    Klascius, A.

    1973-01-01

    The microwave radiation hazards associated with the use of large antennas become increasingly more dangerous to personnel as the transmitters go to ever higher powers. The near-field area is of the greatest concern. It has spill over from subreflector and reflections from nearby objects. Centimeter waves meeting in phase will reinforce each other and create hot spots of microwave energy. This has been measured in front of and around several 26-meter antennas. Hot spots have been found and are going to be the determining factor in delineating safe areas for personnel to work. Better techniques and instruments to measure these fields are needed for the evaluation of hazard areas.

  4. 微波处理油料对油脂品质影响的研究进展%Research advance in effect of microwave treatment of oilseeds on the quality of oil

    Institute of Scientific and Technical Information of China (English)

    王会; 杨湄; 刘昌盛; 黄凤洪

    2011-01-01

    介绍分析了微波处理油料对出油率、原料本身结构、油脂主要理化指标、油脂脂肪酸组成及微量成分和油脂氧化稳定性的影响.结果指出微波处理油料可提高出油率和油脂氧化稳定性,增加营养成分含量,值得推广应用.%The effects of microwave treatment of oilseeds on oil yield, the structural of oilseeds, main physicochemical indexes, fatty acid compositions, trace nutritional components and oxidation stability of the oil were analyzed.Microwave treatment of oilseeds could increase the oil yield, oxidation stability of the oil and the content of nutritional components.The microwave treatment of oilseeds should be widely applied.

  5. Radionuclide brain scanning

    International Nuclear Information System (INIS)

    At one stage of medical imaging development, radionuclide brain scanning was the only technique available for imaging of the brain. Advent of CT and MRI pushed it to the background. It regained some of the grounds lost to ''allied advances'' with the introduction of brain perfusion radiopharmaceuticals. Positron emission tomography is a promising functional imaging modality that at present will remain as a research tool in special centres in developed countries. However, clinically useful developments will gradually percolate from PET to SPECT. The non-nuclear imaging methods are totally instrument dependent; they are somewhat like escalators, which can go that far and no further. Nuclear imaging has an unlimited scope for advance because of the new developments in radiopharmaceuticals. As the introduction of a radiopharmaceutical is less costly than buying new instruments, the recent advances in nuclear imaging are gradually perfusing through the developing countries also. Therefore, it is essential to follow very closely PET developments because what is research today might become routine tomorrow

  6. Analysis and design of coupled-oscillator arrays for microwave systems

    Science.gov (United States)

    Moussounda, Renaud

    The concept of synchronized nonlinear coupled oscillators is applied to microwave and antenna engineering for the analysis and design of wireless communication and sensing systems operating at the microwave and/or millimeter (mm)-wave frequencies. The significance of such approach is justified from the potential gain in efficiency, weight, cost and functionality although technical challenges stand in the way. Unlike typical phased array systems, which are currently used to construct such systems, coupled-oscillator systems present additional challenges that mainly arise from maintaining stability and synchronization as the the coupled nonlinear system is operated. Linear systems do not present such stability issues and are consequently faster since they do not rely on any gradual synchronization mechanism in order to function. However, at significantly higher frequencies in the quasi-optical domain, coupled-oscillator systems can make up for the speed difference and present significant efficiency advantages over typical phased array architectures. In addition, coupled nonlinear systems possess inherent analog properties that can be used for a multitude of functions. This dissertation advances the topic of coupled-oscillator arrays by 1) developing an alternative set of techniques for designing the oscillating unit cells called active integrated antennas (AIAs) at microwave or mm-wave frequencies, 2) developing a more accurate description of the dynamics of the array, 3) developing and implementing a new topology for a coupling network that is able to extend stability, 4) implementing a fully non-reciprocally coupled array able to produce large scan angle without loss of stability, 5) proposing an architecture based on a single phase-locked loop (PLL) and containing a self-calibration mechanism, and finally 6) implementing a phase-boosting mechanism using simple circuits to amplify the phase difference between adjacent radiating antennas in order to increase

  7. Source Analysis of Radio-Frequency Interference over Europe Land from Advanced Microwave Scanning Radiometer-E%星载微波辐射计欧洲大陆无线电频率干扰分析

    Institute of Scientific and Technical Information of China (English)

    官莉; 张思勃

    2014-01-01

    基于2011年6月1日至16日先进微波扫描辐射计(AMSR-E)的观测资料,采用改进的主成分分析算法,对欧洲陆地区域的无线电频率干扰(RFI)进行识别和分析.研究发现影响英国和意大利的X波段RFI源主要是稳定的、持续的地面主动源,而影响欧洲其他国家的RFI则主要是反射的静止电视卫星信号对星载微波被动传感器观测的干扰.源于静止电视卫星的RFI出现位置和强度随时间周期性变化,在欧洲陆地多出现在星载微波辐射计升轨观测上,降轨观测则几乎不受其干扰.RFI出现位置和强度与星载微波辐射计扫描方位角和观测视场相对静止电视卫星的方位有关,只有当星载微波辐射计视场扫描方位角大小与该视场相当于静止卫星发射方位角大小接近时该视场易受RFI影响.

  8. FINITE ELEMENT ANALYSIS FOR OPTIMIZING ANTENNA FOR MICROWAVE COAGULATION THERAPY

    OpenAIRE

    Marwaha, S.; MARWAHA A.; MAINI SURITA

    2012-01-01

    Microwave coagulation therapy (MCT) is emerging as an attractive modality for thermal therapy of soft tissues targeted in short periods of time, making it particularly suitable for ablation of hepatic and other tumors. In this field of microwave coagulation therapy, the use of minimally invasive antenna is recognized as a very promising technique for the treatment of small tumors because a very thin antenna can be easily inserted inside the body and precisely localized using the advanced 3D i...

  9. Facile synthesis of electroluminescence acridinedions by microwave and ultrasound

    International Nuclear Information System (INIS)

    Various highly fluorescent acridinediones were synthesized by microwave and ultrasound irradiations, as well as by conventional thermal methods. It was found that most of the acridinedione derivatives could be obtained in very high yields (80-90%) in the microwave- assisted, solvent-free, one-pot synthesis process within minutes (∼2 min). These highly fluorescent acridinediones are potential new materials for electroluminescence (EL) devices. Copyright (2004) AD-TECH - International Foundation for the Advancement of Technology Ltd

  10. Microwave Drying of Paper Documents

    Czech Academy of Sciences Publication Activity Database

    Hájek, Milan

    Takamatsu, 2004, s. 363-369. [International Symposium on Microwave Science and its Application to Related Fields. Takamatsu (JP), 27.07.2004-30.07.2004] Institutional research plan: CEZ:AV0Z4072921 Keywords : microwave drying * microwave drying technology * microwave radiation Subject RIV: CC - Organic Chemistry

  11. MICROWAVE STABILIZATION AND MICROWAVE-STIMULATED FIXATION

    NARCIS (Netherlands)

    BOON, ME; KOK, LP

    1990-01-01

    In microwave stabilization the tissue is prepared for histoprocessing through the uniformly distributed increased temperature. This procedure can be called unique: Exclusively by the uniform well-controlled temperature rise to 55-degrees-C it is possible to stabilize the tissue to the needed perfect

  12. Gold Nanoparticle Microwave Synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Krantz, Kelsie E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Christian, Jonathan H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Coopersmith, Kaitlin [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Washington, II, Aaron L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Murph, Simona H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-07-27

    At the nanometer scale, numerous compounds display different properties than those found in bulk material that can prove useful in areas such as medicinal chemistry. Gold nanoparticles, for example, display promise in newly developed hyperthermia therapies for cancer treatment. Currently, gold nanoparticle synthesis is performed via the hot injection technique which has large variability in final particle size and a longer reaction time. One underdeveloped area by which these particles could be produced is through microwave synthesis. To initiate heating, microwaves agitate polar molecules creating a vibration that gives off the heat energy needed. Previous studies have used microwaves for gold nanoparticle synthesis; however polar solvents were used that partially absorbed incident microwaves, leading to partial thermal heating of the sample rather than taking full advantage of the microwave to solely heat the gold nanoparticle precursors in a non-polar solution. Through this project, microwaves were utilized as the sole heat source, and non-polar solvents were used to explore the effects of microwave heating only as pertains to the precursor material. Our findings show that the use of non-polar solvents allows for more rapid heating as compared to polar solvents, a reduction in reaction time from 10 minutes to 1 minute, maximizes the efficiency of the reaction, and allows for reproducibility in the size/shape of the fabricated nanoparticles.

  13. Advances in satellite oceanography

    Science.gov (United States)

    Brown, O. B.; Cheney, R. E.

    1983-01-01

    Technical advances and recent applications of active and passive satellite remote sensing techniques to the study of oceanic processes are summarized. The general themes include infrared and visible radiometry, active and passive microwave sensors, and buoy location systems. The surface parameters of sea surface temperature, windstream, sea state, altimetry, color, and ice are treated as applicable under each of the general methods.

  14. Microwave integrated circuits for space applications

    Science.gov (United States)

    Leonard, Regis F.; Romanofsky, Robert R.

    1991-01-01

    Monolithic microwave integrated circuits (MMIC), which incorporate all the elements of a microwave circuit on a single semiconductor substrate, offer the potential for drastic reductions in circuit weight and volume and increased reliability, all of which make many new concepts in electronic circuitry for space applications feasible, including phased array antennas. NASA has undertaken an extensive program aimed at development of MMICs for space applications. The first such circuits targeted for development were an extension of work in hybrid (discrete component) technology in support of the Advanced Communication Technology Satellite (ACTS). It focused on power amplifiers, receivers, and switches at ACTS frequencies. More recent work, however, focused on frequencies appropriate for other NASA programs and emphasizes advanced materials in an effort to enhance efficiency, power handling capability, and frequency of operation or noise figure to meet the requirements of space systems.

  15. Nonlinear Integrated Microwave Photonics

    CERN Document Server

    Marpaung, David

    2013-01-01

    Harnessing nonlinear optical effects in a photonic chip scale has been proven useful for a number of key applications in optical communications. Microwave photonics can also benefit from the adoption of such a technology, creating a new concept of nonlinear integrated microwave photonics. Here, we discuss the potential of on-chip nonlinear processing towards the creation of robust and multifunctional microwave photonic (MWP) processors. We also highlight key recent results in the field, including frequency agile MWP filters and ultra-wideband signal generators.

  16. Microwaves - the hidden danger

    International Nuclear Information System (INIS)

    Today, highly frequent radio waves are regarded as undangerous to man. Diseases seen at radar-technicians during the 2nd World War, however, indicated that microwaves applied in radar systems were hazardous to health. The Russian work medicine has been knowing microwave-caused hazards in industry since the beginning of the thirties. Therefore in some East-European countries there are terms of protection and severe norms of safety for the staying of persons in the radiation sphere of microwaves. (orig./MG)

  17. Microwave vision for robots

    Science.gov (United States)

    Lewandowski, Leon; Struckman, Keith

    1994-01-01

    Microwave Vision (MV), a concept originally developed in 1985, could play a significant role in the solution to robotic vision problems. Originally our Microwave Vision concept was based on a pattern matching approach employing computer based stored replica correlation processing. Artificial Neural Network (ANN) processor technology offers an attractive alternative to the correlation processing approach, namely the ability to learn and to adapt to changing environments. This paper describes the Microwave Vision concept, some initial ANN-MV experiments, and the design of an ANN-MV system that has led to a second patent disclosure in the robotic vision field.

  18. The Microwave Hall Effect

    OpenAIRE

    Coppock, J. E.; Anderson, J R; Johnson, W. B.

    2015-01-01

    This paper describes a simple microwave apparatus to measure the Hall effect in semiconductor wafers. The advantage of this technique is that it does not require contacts on the sample or the use of a resonant cavity. Our method consists of placing the semiconductor wafer into a slot cut in an X-band (8 - 12 GHz) waveguide series tee, injecting microwave power into the two opposite arms of the tee, and measuring the microwave output at the third arm. A magnetic field applied perpendicular to ...

  19. High power microwave sources

    International Nuclear Information System (INIS)

    High power microwaves have known a great expansion with intense relativistic electron beams. CEA-CESTA evolved several HPM sources on electron beam generator CESAR, as the planar VIRCATOR, the REDITRON and the coaxial VIRCATOR. We obtained microwave frequencies located between 2 and 8 GHz with power of some hundreds until 1 gigawatt. Several measurements have been improved to qualify these sources: frequency, power density, energy, wave polarization, modes visualization. A hollow beam generator, relativistic klystron electric source, has also been built to improve a recurrent system and obtain gigawatt microwave power. (author)

  20. The microwave enhanced bolometer

    International Nuclear Information System (INIS)

    The microwave enhanced bolometer is a proposed cryogenic detector with an amplification mechanism. It consists of a crystal covered with a superconducting film exposed to a microwave flux. Incident particles will create nonthermal phonons in the crystal which then produce excess quasiparticles in the film. Those quasiparticles lead to microwave absorption in the film and a subsequent heating of the entire bolometer. In this way the energy deposited by a particle in the crystal could be amplified linearly by gains of up to 104. This would make possible bolometers of several kilograms with an excellent energy resolution which could be used for dark matter search or double beta decay experiments. (orig.)

  1. Artificial color perception using microwaves

    OpenAIRE

    Choudhury, Debesh; Caulfield, H. John

    2013-01-01

    We report the feasibility of artificial color perception under microwave illumination using a standard microwave source and an antenna. We have sensed transmitted microwave power through color objects and have distinguished the colors by analyzing the sensed transmitted power. Experiments are carried out using a Gunn diode as the microwave source, some colored liquids as the objects and a microwave diode as the detector. Results are presented which open up an unusual but new way of perceiving...

  2. Head CT scan

    Science.gov (United States)

    Brain CT; Cranial CT; CT scan - skull; CT scan - head; CT scan - orbits; CT scan - sinuses; Computed tomography - cranial ... The x-rays produced by the CT scan are painless. Some people may ... hard table. Contrast given through a vein may cause a: Slight ...

  3. Exploring the Turbulent Urban Boundary by Use of Lidars and Microwave Radiometers

    Science.gov (United States)

    Arend, Mark; Valerio, Ivan; Neufeld, Stephen; Bishir, Raymond; Wu, Younghu; Moshary, Fred; Melecio-Vazquez, David; Gonzalez, Jorge

    2016-06-01

    A Doppler lidar has been developed using fiber optic based technologies and advanced signal processing techniques. Although this system has been operated in a scanning mode in the past, for this application, the system is operated in a vertically pointing mode and delivers a time series of vertical velocity profiles. By cooperating the Doppler lidar with other instruments, including a back scatter lidar, and a microwave radiometer, models of atmospheric stability can be tested, opening up an exciting path for researchers, applied scientists and engineers to discover unique phenomena related to fundamental atmospheric science processes. A consistent set of retrievals between each of these instruments emphasizes the utility for such a network of instruments to better characterize the turbulent atmospheric urban boundary layers which is expected to offer a useful capability for assessing and improving models that are in great need of such ground truth.

  4. Exploring the Turbulent Urban Boundary by Use of Lidars and Microwave Radiometers

    Directory of Open Access Journals (Sweden)

    Arend Mark

    2016-01-01

    Full Text Available A Doppler lidar has been developed using fiber optic based technologies and advanced signal processing techniques. Although this system has been operated in a scanning mode in the past, for this application, the system is operated in a vertically pointing mode and delivers a time series of vertical velocity profiles. By cooperating the Doppler lidar with other instruments, including a back scatter lidar, and a microwave radiometer, models of atmospheric stability can be tested, opening up an exciting path for researchers, applied scientists and engineers to discover unique phenomena related to fundamental atmospheric science processes. A consistent set of retrievals between each of these instruments emphasizes the utility for such a network of instruments to better characterize the turbulent atmospheric urban boundary layers which is expected to offer a useful capability for assessing and improving models that are in great need of such ground truth.

  5. Calibration methods for ECE systems with microwave sources

    International Nuclear Information System (INIS)

    The authors investigated the feasibility of two methods for calibration of electron cyclotron emission (ECE) systems, both based on the use of a microwave source. In the first method -called the Antenna Pattern Integration (API) method - the microwave source is scanned in space, so as to simulate a large - area - blackbody -source. In the second method -called the Untuned Cavity (UC) method -an untuned cavity, fed by the microwave source, is used to simulate a blackbody. For both methods, the hardware required to perform partly automated calibrations was developed. The microwave based methods were compared with a large area blackbody calibration on two different ECE systems, a Michelson interferometer and a grating polychromator. The API method was found to be more successful than the UC method. (author)

  6. Microwave-assisted extraction of polysaccharides from solanum nigrum

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiao-qing; LIU-qin; JIANG xin-yu; ZENG fan

    2005-01-01

    The microwave-assisted method was used to extract polysaccharides from solanum nigrum. The optimum experimental parameters, mechanism of the extraction and the effect of microwave-assisted extraction process on the structures of polysaccharides were investigated. The extract was analyzed by the modified phenol-sulfuric acid method at 490 nm. The optimum experimental parameters were obtained by orthogonal experiments as follows: extraction time 15 min, microwave radiation power 455 W and the process ratio of materials mass to solvent volume 1∶20. The results show that compared with the conventional reflux extraction, the microwave-assisted extraction has a higher yield in shorter time, with no effect on the finally obtained polysaccharides as seen from the FT-IR spectra. The scanning electron microscopy images reveal that the mechanism of the extraction is related to the structural changes of the plant cells in different extracting conditions.

  7. Estimating the breast surface using UWB microwave monostatic backscatter measurements.

    Science.gov (United States)

    Winters, David W; Shea, Jacob D; Madsen, Ernest L; Frank, Gary R; Van Veen, Barry D; Hagness, Susan C

    2008-01-01

    This paper presents an algorithm for estimating the location of the breast surface from scattered ultrawideband (UWB) microwave signals recorded across an antenna array. Knowing the location of the breast surface can improve imaging performance if incorporated as a priori information into recently proposed microwave imaging algorithms. These techniques transmit low-power microwaves into the breast using an antenna array, which in turn measures the scattered microwave signals for the purpose of detecting anomalies or changes in the dielectric properties of breast tissue. Our proposed surface identification algorithm consists of three procedures, the first of which estimates M points on the breast surface given M channels of measured microwave backscatter data. The second procedure applies interpolation and extrapolation to these M points to generate N > M points that are approximately uniformly distributed over the breast surface, while the third procedure uses these N points to generate a 3-D estimated breast surface. Numerical as well as experimental tests indicate that the maximum absolute error in the estimated surface generated by the algorithm is on the order of several millimeters. An error analysis conducted for a basic microwave radar imaging algorithm (least-squares narrowband beamforming) indicates that this level of error is acceptable. A key advantage of the algorithm is that it uses the same measured signals that are used for UWB microwave imaging, thereby minimizing patient scan time and avoiding the need for additional hardware. PMID:18232368

  8. Microwave Radiation Detector

    Science.gov (United States)

    Lesh, J. R.

    1984-01-01

    Direct photon detector responds to microwave frequencies. Method based on trapped-ion frequency-generation standards proposed to detect radio-frequency (RF) radiation at 40.5 GHz. Technique used for directdetection (RF) communication, radar, and radio astronomy.

  9. Microwave Radiometer - high frequency

    Data.gov (United States)

    Oak Ridge National Laboratory — The Microwave Radiometer-High Frequency (MWRHF) provides time-series measurements of brightness temperatures from two channels centered at 90 and 150 GHz. These two...

  10. Microwave Radiometer Profiler

    Data.gov (United States)

    Oak Ridge National Laboratory — The microwave radiometer profiler (MWRP) provides vertical profiles of temperature, humidity, and cloud liquid water content as a function of height or pressure at...

  11. Microwave Service Towers

    Data.gov (United States)

    Department of Homeland Security — This file is an extract of the Universal Licensing System (ULS) licensed by the Wireless Telecommunications Bureau (WTB). It consists of Microwave Transmitters (see...

  12. Integrated microwave photonics

    OpenAIRE

    Marpaung, David; Roeloffzen, Chris; Heideman, Rene; Leinse, Arne; Sales, Salvador; Capmany, Jose

    2012-01-01

    Microwave photonics (MWP) is an emerging field in which radio frequency (RF) signals are generated, distributed, processed and analyzed using the strength of photonic techniques. It is a technology that enables various functionalities which are not feasible to achieve only in the microwave domain. A particular aspect that recently gains significant interests is the use of photonic integrated circuit (PIC) technology in the MWP field for enhanced functionalities and robustness as well as the r...

  13. Microwave workshop for Windows

    OpenAIRE

    White, Colin

    1995-01-01

    A suite of three programs has been developed to support the teaching of microwave theory and design. A secondary function of the package is to support microwave engineers by providing a library of utilities to assist their design function. All three programs were written in Visual Basic and are aimed at supporting both tutor-directed and student-centred learning methodologies. The development team consisted of three final-year degree students.DOI:10.1080/0968776950030109

  14. Microwaves in Airborne Surveillance

    OpenAIRE

    Christopher, S.

    2013-01-01

    The use of microwave spectrum is widespread due to its convenience. Therefore, enormous amount of information is available in the free space channel. Obviously, mining this channel for surveillance is quite common. Airborne surveillance offers significant advantages in military operations. This paper talks of the usage of microwaves in airborne surveillance systems, in general, and in the Indian airborne early warning and control (AEW&C) System, in particular. It brings out the multiple s...

  15. RBC nuclear scan

    Science.gov (United States)

    An RBC nuclear scan uses small amounts of radioactive material to mark (tag) red blood cells (RBCs). Your body is then ... scanner does not give off any radiation. Most nuclear scans (including an RBC scan) are not recommended ...

  16. Heart PET scan

    Science.gov (United States)

    ... nuclear medicine scan; Heart positron emission tomography; Myocardial PET scan ... A PET scan requires a small amount of radioactive material (tracer). This tracer is given through a vein (IV), ...

  17. Coronary Calcium Scan

    Science.gov (United States)

    ... the NHLBI on Twitter. What Is a Coronary Calcium Scan? A coronary calcium scan is a test ... you have calcifications in your coronary arteries. Coronary Calcium Scan Figure A shows the position of the ...

  18. Removing upwind/downwind ambiguity of ocean wind direction by polarimetric microwave radiometer: scheme design on on-orbit calibration and scanning geometry%一种消除全极化微波辐射计顺/逆风向遥感模糊性的新方案——星上定标和扫描机制设计的有关考虑

    Institute of Scientific and Technical Information of China (English)

    王振占; 刘璟怡; 殷晓斌; 姜景山

    2009-01-01

    Polarimetric microwave radiometer, a new type of remote sensor, can measure not only the first two Stokes parameters, but also the third and the fourth Stokes parameter of ocean surface radiation. Thus it opens a new field of microwave remote sensing on wind vectors. There is wind direction ambiguity in actually retrieved oceanic wind field using fully polarimetric radiometer data because wind direction signals in T, and Th are very small comparing with other geophysical parameters, while T and T are basically two order smaller than those of horizontal and vertical polarization, and meanwhile there are calibration errors in each Stokes parameters. In this paper, we dedicate to improve the calibration accuracy by designing a fully onboard calibrator and reasonably allocating time for calibration and observation during one scan cycle. The theory of polarimetric microwave radiometer calibration is given and the actual considerations of the on-board fully polarimetric calibration standard are demonstrated. An original idea of calibrating polarimetric radiometer on satellite is presented. The relation between scan mode and wind direction retrieval error is analyzed. A new scanning geometry to remove these wind direction ambiguous solutions is devised and modeled. Simulation results show this kind of scanning geometry can remove wind direction ambiguity effectively. The accuracy of wind direction retrieval can be improved to 15°. On the other hand, due to the limited space on satellite, the swath of a single side scan can reach above 760 kilometers.%从观测方式的角度出发,讨论消除全极化微波辐射计遥感风向(顺风/逆风)模糊性的具体实施方案,提出合理进行星上定标和对地观测的设计思想.在研究全极化辐射计星上外定标方法的基础上,依据消除海面风向反演模糊性的算法,提出一种采用侧视扫描的机制,设计了在星上实现全极化微波辐射计对同一面元进行前、后两次扫描

  19. Scan BIST with biased scan test signals

    Institute of Scientific and Technical Information of China (English)

    XIANG Dong; CHEN MingJing; SUN JiaGuang

    2008-01-01

    The conventional test-per-scan built-in self-test (BIST) scheme needs a number of shift cycles followed by one capture cycle.Fault effects received by the scan flip-flops are shifted out while shifting in the next test vector like scan testing.Unlike deterministic testing,it is unnecessary to apply a complete test vector to the scan chains.A new scan-based BIST scheme is proposed by properly controlling the test signals of the scan chains,Different biased random values are assigned to the test signals of scan flip-flops in separate scan chains.Capture cycles can be inserted at any clock cycle if necessary.A new testability estimation procedure according to the proposed testing scheme is presented.A greedy procedure is proposed to select a weight for each scan chain.Experimental results show that the proposed method can improve test effectiveness of scan-based BIST greatly,and most circuits can obtain complete fault coverage or very close to complete fault coverage.

  20. Quartz tuning fork based microwave impedance microscopy

    Science.gov (United States)

    Cui, Yong-Tao; Ma, Eric Yue; Shen, Zhi-Xun

    2016-06-01

    Microwave impedance microscopy (MIM), a near-field microwave scanning probe technique, has become a powerful tool to characterize local electrical responses in solid state samples. We present the design of a new type of MIM sensor based on quartz tuning fork and electrochemically etched thin metal wires. Due to a higher aspect ratio tip and integration with tuning fork, such design achieves comparable MIM performance and enables easy self-sensing topography feedback in situations where the conventional optical feedback mechanism is not available, thus is complementary to microfabricated shielded stripline-type probes. The new design also enables stable differential mode MIM detection and multiple-frequency MIM measurements with a single sensor.

  1. CURING OF POLYMERIC COMPOSITES USING MICROWAVE RESIN TRANSFER MOULDING (RTM

    Directory of Open Access Journals (Sweden)

    R. YUSOFF

    2007-08-01

    Full Text Available The main objective of this work is to compare the difference between microwave heating and conventional thermal heating in fabricating carbon/epoxy composites. Two types of epoxy resin systems were used as matrices, LY5052-HY5052 and DGEBA-HY917-DY073. All composite samples were fabricated using resin transfer moulding (RTM technique. The curing of the LY5052-HY5052-carbon and the DGEBA-HY917-DY073-carbon composite systems, were carried out at 100 °C and 120 °C, respectively. Microwave heating showed better temperature control than conventional heating, however, the heating rate of the microwave cured samples were slower than the conventionally cured samples. This was attributed to the lower power (250 W used when heating with microwaves compared to 2000 W used in conventional heating. Study of thermal characteristics as curing progressed showed that the polymerisation reaction occurred at a faster rate during microwave curing than in conventional curing for both the DGEBA and the LY/HY5052 carbon composite systems. The actual cure cycle was reduced from 60 minutes to 40 minutes when using microwaves for curing DGEBA-carbon composites. As for LY/HY5052-carbon composites, the actual cure cycle was reduced from 3 hours to 40 minutes. Both conventional and microwave heating yielded similar glass transition temperatures (120 °C for DGEBA systems and 130 °C for LY/HY5052 systems. Microwave cured composites had higher void contents than conventionally cured composites (2.2-2.8% and 1.8-2.4% for DGEBA and LY/HY5052 microwave cured composites, respectively, compared to 0.2-0.4% for both DGEBA and LY/HY5052 thermally cured composites. C-scan traces showed that all composites, regardless of methods of curing, had minimal defects.

  2. The applications of microwave energy to improve grindability and extraction of gold ores

    CERN Document Server

    Huang, J H

    2000-01-01

    decomposed than pyrite at the same exposure conditions. Scanning electron microscope (SEM), optical microscope, and X-ray diffraction results indicated that the alterations during microwave treatment were complex. Some intermediate products (e.g. Fe sub ( sub 1 sub - sub x sub ) S) were formed before the sulphides were completely oxidised into hematite (Fe sub 2 O sub 3). Oxidation developed from the surfaces into the cores of the microwaved particles. Metallic particles were also formed during microwave exposure. Lihir gold ore, in which gold was finely disseminated in pyrite and marcasite, was an extremely refractory gold ore. Without pretreatment, only 37 approx 39% of the gold could be extracted with sodium cyanide. However, this was improved after the head ores or floatation concentrates were pretreated by microwave radiation. 74.5 approx 81.2% of the gold was extracted from the microwave treated head ore. The hydrometallurgical pretreatment of pyrite and marcasite in a microwave field and a conventional...

  3. Manufacturing of kevlar/polyester composite by resin transfer moulding using conventional and microwave heating

    International Nuclear Information System (INIS)

    Microwave heating was incorporated into the resin transfer moulding technique. Polytetrafluoroethylene (PTFE) mould was used to cure the composite panel. Through the use of microwave heating, the mechanical and physical properties of produced Kevlar fibre/polyester composites were compared to those manufactured by conventional resin transfer moulding. The flexural modulus and flexural strength of 6-ply conventionally cured composites was 45% and 9% higher than the flexural modulus and flexural strength of 6-ply microwaved cured composites, respectively. However, 19% increase in interlaminar shear strength (ILSS) and 2% increase in compressive strength was observed in 6-ply microwave cured composites. This enhancement in ILSS and compressive strength is attributed to the better interfacial bonding of polyester resin with Kevlar fibres in microwaved cured composite, which was also confirmed via electron microscopy scanning. Furthermore, the microwave cured composite yielded maximum void contents (3%). (author)

  4. Microwave processing of ceramic oxide filaments. Annual report, FY1997

    Energy Technology Data Exchange (ETDEWEB)

    Vogt, G.J.

    1998-12-31

    The objective of the microwave filament processing project is to develop microwave techniques to manufacture continuous ceramic oxide filaments. Microwave processing uses the volumetric absorption of microwave power in oxide filament tows to drive off process solvents, to burn out organic binders, and to sinter the dried fibers to produce flexible, high-strength ceramic filaments. The technical goal is to advance filament processing technology by microwave heating more rapidly with less energy and at a lower cost than conventional processing, but with the same quality as conventional processing. The manufacturing goal is to collaborate with the 3M Company, a US manufacturer of ceramic oxide filaments, to evaluate the technology using a prototype filament system and to transfer the microwave technology to the 3M Company. Continuous ceramic filaments are a principal component in many advanced high temperature materials like continuous fiber ceramic composites (CFCC) and woven ceramic textiles. The use of continuous ceramic filaments in CFCC radiant burners, gas turbines, waste incineration, and hot gas filters in U.S. industry and power generation is estimated to save at least 2.16 quad/yr by year 2010 with energy cost savings of at least $8.1 billion. By year 2010, continuous ceramic filaments and CFCC`s have the potential to abate pollution emissions by 917,000 tons annually of nitrous oxide and 118 million tons annually of carbon dioxide (DOE Report OR-2002, February, 1994).

  5. Daily SST fields produced by blending infrared and microwave radiometer estimates

    Digital Repository Service at National Institute of Oceanography (India)

    Sreejith, O.P.; Shenoi, S.S.C.

    the summer monsoon (June-September). The recent advances in the microwave remote sensing of SST provides an alternative for the retrieval of SSTs in the presence of clouds. The microwaves, though they can measure the SSTs in the presence of clouds...

  6. Adaptive and Intelligent Temperature Control of Microwave Heating Systems with Multiple Sources

    OpenAIRE

    Sun, Yiming

    2016-01-01

    In this work, an innovative real-time microwave control approach is proposed, to improve the temperature homogeneity under microwave heating. Multiple adaptive or intelligent control structures have been developed, including the model predictive control, neural network control and reinforcement learning control methods. Experimental results prove that these advanced control methods can effectively reduce the final temperature derivations and improve the temperature homogeneity.

  7. Design of a microwave calorimeter for the microwave tokamak experiment

    Energy Technology Data Exchange (ETDEWEB)

    Marinak, M. (California Univ., Berkeley, CA (USA))

    1988-10-07

    The initial design of a microwave calorimeter for the Microwave Tokamak Experiment is presented. The design is optimized to measure the refraction and absorption of millimeter rf microwaves as they traverse the toroidal plasma of the Alcator C tokamak. Techniques utilized can be adapted for use in measuring high intensity pulsed output from a microwave device in an environment of ultra high vacuum, intense fields of ionizing and non-ionizing radiation and intense magnetic fields. 16 refs.

  8. Design of a microwave calorimeter for the microwave tokamak experiment

    International Nuclear Information System (INIS)

    The initial design of a microwave calorimeter for the Microwave Tokamak Experiment is presented. The design is optimized to measure the refraction and absorption of millimeter rf microwaves as they traverse the toroidal plasma of the Alcator C tokamak. Techniques utilized can be adapted for use in measuring high intensity pulsed output from a microwave device in an environment of ultra high vacuum, intense fields of ionizing and non-ionizing radiation and intense magnetic fields. 16 refs

  9. The boundary-scan handbook

    CERN Document Server

    Parker, Kenneth P

    2016-01-01

    Aimed at electronics industry professionals, this 4th edition of the Boundary Scan Handbook describes recent changes to the IEEE1149.1 Standard Test Access Port and Boundary-Scan Architecture. This updated edition features new chapters on the possible effects of the changes on the work of the practicing test engineers and the new 1149.8.1 standard. Anyone needing to understand the basics of boundary scan and its practical industrial implementation will need this book. Provides an overview of the recent changes to the 1149.1 standard and the effect of the changes on the work of test engineers;   Explains the new IEEE 1149.8.1 subsidiary standard and applications;   Describes the latest updates on the supplementary IEEE testing standards. In particular, addresses: IEEE Std 1149.1                      Digital Boundary-Scan IEEE Std 1149.4                      Analog Boundary-Scan IEEE Std 1149.6                      Advanced I/O Testing IEEE Std 1149.8.1           �...

  10. Polish Experience with Advanced Digital Heritage Recording Methodology, including 3D Laser Scanning, CAD, and GIS Application, as the Most Accurate and Flexible Response for Archaeology and Conservation Needs at Jan III Sobieski's Residence in Wilanów

    Science.gov (United States)

    Baranowski, P.; Czajkowski, K.; Gładki, M.; Morysiński, T.; Szambelan, R.; Rzonca, A.

    Review of recent critical points for introduction of laser technology into the field of heritage documentation, management, conservation, and archaeology will be discussed. The relationship of benefit versus cost of 3D laser scanning technique for complex multitask heritage recording project at Wilanow is presented. Definition of basic criteria for the successful use of such heritage detailed record as laser scanning is given.

  11. Microwave engineering concepts and fundamentals

    CERN Document Server

    Khan, Ahmad Shahid

    2014-01-01

    Detailing the active and passive aspects of microwaves, Microwave Engineering: Concepts and Fundamentals covers everything from wave propagation to reflection and refraction, guided waves, and transmission lines, providing a comprehensive understanding of the underlying principles at the core of microwave engineering. This encyclopedic text not only encompasses nearly all facets of microwave engineering, but also gives all topics—including microwave generation, measurement, and processing—equal emphasis. Packed with illustrations to aid in comprehension, the book: •Describes the mathematical theory of waveguides and ferrite devices, devoting an entire chapter to the Smith chart and its applications •Discusses different types of microwave components, antennas, tubes, transistors, diodes, and parametric devices •Examines various attributes of cavity resonators, semiconductor and RF/microwave devices, and microwave integrated circuits •Addresses scattering parameters and their properties, as well a...

  12. Spatio-temporal evaluation of resolution enhancement for passive microwave soil moisture and vegetation optical depth

    Science.gov (United States)

    Gevaert, A. I.; Parinussa, R. M.; Renzullo, L. J.; van Dijk, A. I. J. M.; de Jeu, R. A. M.

    2016-03-01

    Space-borne passive microwave radiometers are used to derive land surface parameters such as surface soil moisture and vegetation optical depth (VOD). However, the value of such products in regional hydrology is limited by their coarse resolution. In this study, the land parameter retrieval model (LPRM) is used to derive enhanced resolution (∼10 km) soil moisture and VOD from advanced microwave scanning radiometer (AMSR-E) brightness temperatures sharpened by a modulation technique based on high-frequency observations. A precipitation mask based on brightness temperatures was applied to remove precipitation artefacts in the sharpened LPRM products. The spatial and temporal patterns in the resulting products are evaluated against field-measured and modeled soil moisture as well as the normalized difference vegetation index (NDVI) over mainland Australia. Results show that resolution enhancement accurately sharpens the boundaries of different vegetation types, lakes and wetlands. Significant changes in temporal agreement between LPRM products and related datasets are limited to specific areas, such as lakes and coastal areas. Spatial correlations, on the other hand, increase over most of Australia. In addition, hydrological signals from irrigation and water bodies that were absent in the low-resolution soil moisture product become clearly visible after resolution enhancement. The increased information detail in the high-resolution LPRM products should benefit hydrological studies at regional scales.

  13. Classification of Tropical Oceanic Precipitation using High Altitude Aircraft: Microwave and Electric Field Measurements

    Science.gov (United States)

    Hood, Robbie E.; Cecil, Daniel; LaFontaine, Frank J.; Blakeslee, Richard; Mach, Douglas; Heymsfield, Gerald; Marks, Frank, Jr.; Zipser, Edward

    2004-01-01

    During the 1998 and 2001 hurricane seasons of the western Atlantic Ocean and Gulf of Mexico, the Advanced Microwave Precipitation Radiometer (AMPR), the ER-2 Doppler (EDOP) radar, and the Lightning Instrument Package (LIP) were flown aboard the National Aeronautics and Space Administration ER-2 high altitude aircraft as part of the Third Convection and Moisture Experiment (CAMEX-3) and the Fourth Convection and Moisture Experiment (CAMEX-4). Several hurricanes, tropical storms, and other precipitation systems were sampled during these experiments. An oceanic rainfall screening technique has been developed using AMPR passive microwave observations of these systems collected at frequencies of 10.7, 19.35,37.1, and 85.5 GHz. This technique combines the information content of the four AMPR frequencies regarding the gross vertical structure of hydrometeors into an intuitive and easily executable precipitation mapping format. The results have been verified using vertical profiles of EDOP reflectivity and lower altitude horizontal reflectivity scans collected by the National Oceanic and Atmospheric Administration WP-3D Orion radar. Matching the rainfall classification results with coincident electric field information collected by the LIP readily identifies convective rain regions within the precipitation fields. This technique shows promise as a real-time research and analysis tool for monitoring vertical updraft strength and convective intensity from airborne platforms such as remotely operated or uninhabited aerial vehicles. The technique is analyzed and discussed for a wide variety of precipitation types using the 26 August 1998 observations of Hurricane Bonnie near landfall.

  14. Classification of Tropical Oceanic Precipitation using High-Altitude Aircraft Microwave and Electric Field Measurements

    Science.gov (United States)

    Hood, Robbie E.; Cecil, Daniel J.; LaFontaine, Frank J.; Blakeslee, Richard J.; Mach, Douglas m.; Heymsfield, Gerald M.; Marks, Frank D., Jr.; Zipser, Edward J.

    2004-01-01

    During the 1998 and 2001 hurricane seasons of the western Atlantic Ocean and Gulf of Mexico, the Advanced Microwave Precipitation Radiometer (AMPR), the ER-2 Doppler (EDOP) radar, and the Lightning Instrument Package (LIP) were flown aboard the NASA ER-2 high-altitude aircraft as part of the Third Convection and Moisture Experiment (CAMEX-3) and the Fourth Convection and Moisture Experiment (CAMEX-4). Several hurricanes, tropical storms, and other precipitation systems were sampled during these experiments. An oceanic rainfall screening technique has been developed using AMPR passive microwave observations of these systems collected at frequencies of 10.7, 19.35, 37.1, and 85.5 GHz. This technique combines the information content of the four AMPR frequencies regarding the gross vertical structure of hydrometeors into an intuitive and easily executable precipitation mapping format. The results have been verified using vertical profiles of EDOP reflectivity and lower-altitude horizontal reflectivity scans collected by the NOAA WP3D Orion radar. Matching the rainfall classification results with coincident electric field information collected by the LIP readily identifies convective rain regions within the precipitation fields. This technique shows promise as a real-time research and analysis tool for monitoring vertical updraft strength and convective intensity from airborne platforms such as remotely operated or uninhabited aerial vehicles. The technique is analyzed and discussed for a wide variety of precipitation types using the 26 August 1998 observations of Hurricane Bonnie near landfall.

  15. [Study of the microwave emissivity characteristics of vegetation over the Northern Hemisphere].

    Science.gov (United States)

    Shi, Li-Juan; Qiu, Yu-Bao; Shi, Jian-Cheng

    2013-05-01

    The microwave emissivity is a function of structure, water content, and surface roughness, and all these factors have obvious seasonal variations. In the present study, the half-month averaged emissivities in summer and winter of 2003 over the vegetation of Northern Hemisphere were estimated using Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E) combined with IGBP (International Geosphere-Biosphere Project labels) land classification data. Then the emissivities of vegetation land covers at different frequencies, the polarization and their seasonal variations were analyzed respectively. The results show that the emissivities of vegetation increase with the increase in frequencies, and decline with the frequency increasing over snow region. In summer, the vegetation emissivity at V-polarization of 89 GHz is larger than 0.944, and all emissivities are relatively stable and the RMSE of time series emissivity variation is less than 0.007 2. In winter, emissivities decrease over snow covered area, especially for higher frequencies. Furthermore, with the increase in vegetation density, the emissivities increase and emissivity polarization difference decreases. PMID:23905309

  16. An algorithm to detect sea ice leads using AMSR-E passive microwave imagery

    Directory of Open Access Journals (Sweden)

    J. Röhrs

    2010-02-01

    Full Text Available Leads are major sites of energy fluxes and brine releases at the air-ocean interface of sea ice covered oceans. This study presents an algorithm to detect leads that are broader than 3 km in the entire Arctic Ocean. The algorithm detected 50% of the lead area that is visible in optical satellite images. Passive microwave imagery from the Advanced Microwave Scanning Radiometer – Earth Observation System (AMSR-E is used, allowing daily observations that are independent of daylight or cloud conditions. Using unique signatures of thin ice in the brightness temperature ratio between the 89 GHz and 19 GHz channels, the algorithm allowed to detect thin ice features in the ice cover and is optimized to detect leads. Leads were mapped for the period from 2002–2009 excluding the summer months. Several frequently reoccurring large scale lead patterns were found, especially in regions where sea ice is known to drift out of the Arctic Ocean. The maximum lead occurrence in the Arctic is located in the Beaufort Sea, low lead occurrence was found in the inner Arctic Ocean close to the North Pole.

  17. Land surface model calibration through microwave data assimilation for improving soil moisture simulations

    Science.gov (United States)

    Yang, Kun; Zhu, La; Chen, Yingying; Zhao, Long; Qin, Jun; Lu, Hui; Tang, Wenjun; Han, Menglei; Ding, Baohong; Fang, Nan

    2016-02-01

    Soil moisture is a key variable in climate system, and its accurate simulation needs effective soil parameter values. Conventional approaches may obtain soil parameter values at point scale, but they are costly and not efficient at grid scale (10-100 km) of current climate models. This study explores the possibility to estimate soil parameter values by assimilating AMSR-E (Advanced Microwave Scanning Radiometer for Earth Observing System) brightness temperature (TB) data. In the assimilation system, the TB is simulated by the coupled system of a land surface model (LSM) and a radiative transfer model (RTM), and the simulation errors highly depend on parameters in both the LSM and the RTM. Thus, sensitive soil parameters may be inversely estimated through minimizing the TB errors. A crucial step for the parameter estimation is made to suppress the contamination of uncertainties in atmospheric forcing data. The effectiveness of the estimated parameter values is evaluated against intensive measurements of soil parameters and soil moisture in three grasslands of the Tibetan Plateau and the Mongolian Plateau. The results indicate that this satellite data-based approach can improve the data quality of soil porosity, a key parameter for soil moisture modeling, and LSM simulations with the estimated parameter values reasonably reproduce the measured soil moisture. This demonstrates it is feasible to calibrate LSMs for soil moisture simulations at grid scale by assimilating microwave satellite data, although more efforts are expected to improve the robustness of the model calibration.

  18. Radiation-hardened microwave communications system

    International Nuclear Information System (INIS)

    To develop a wireless communication system to meet the stringent requirements for a nuclear hot cell and similar environments, including control of advanced servomanipulators, a microwave signal transmission system development program was established to produce a demonstration prototype for the Consolidated Fuel Reprocessing Program at Oak Ridge National Laboratory (ORNL). Proof-of-principle tests in a partially metal lined enclosure at ORNL successfully demonstrated the feasibility of directed microwave signal transmission techniques for remote systems applications. The potential for much more severe radio-frequency (RF) multipath propagation conditions in fully metal lined cells led to a programmatic decision to conduct additional testing in more typical hot-cell environments at other sites. Again, the test results were excellent. Based on the designs of the earlier systems, an advanced microwave signal transmission system configuration was subsequently developed that, in highly reflective environments, will support both high-performance video channels and high baud-rate digital data links at total gamma dose tolerance levels exceeding 107 rads and at elevated ambient temperatures

  19. Recent Breakthroughs in Microwave Photonics

    OpenAIRE

    Gasulla Mestre, Ivana; Lloret Soler, Juan Antonio; Sancho Durá, Juan; Sales Maicas, Salvador; Capmany Francoy, José

    2011-01-01

    We present a brief review of recent accomplishments in the field of Microwave Photonics (MWP). Recent research across a broad range of MWP applications is summarized, including photonic generation of microwave, millimeter, and Terahertz waves; broadband optical beamforming for phased array antennas; tunable, reconfigurable, and adaptive microwave photonic filtering, as well as the application of slow and fast light effects to the implementation of tunable microwave phase shifting and true tim...

  20. Microwave enhanced processing of ores

    OpenAIRE

    Kobusheshe, Joseph

    2010-01-01

    Recent research developments have suggested that microwave assisted comminution could provide a step change in ore processing. This is based on the fact that microwave-absorbent phases within a multi-mineral ore can be selectively heated by microwave energy hence inducing internal stresses that create fracture. A detailed review of existing literature revealed that little or no information is available which relates and examines the influence of hydrated minerals on microwave assisted fr...

  1. Global Mapping of Landscape Freeze-Thaw Status Using Spaceborne Microwave Remote Sensing

    Science.gov (United States)

    Kim, Y.; Kimball, J. S.; McDonald, K. C.; Glassy, J.

    2009-12-01

    The freeze-thaw (F/T) status of the landscape is closely linked to surface energy budget and hydrological activity, vegetation phenology, terrestrial carbon budgets and land-atmosphere trace gas exchange. Spaceborne microwave radars and radiometers are ideally suited for global F/T monitoring due to insensitivity to signal degradation by atmospheric contamination, and solar illumination effects are uniquely capable of detecting the distinct change in landscape dielectric properties between predominantly frozen and thawed states, and provide a surrogate measure of a range of biophysical processes associated with the F/T signal, especially at high latitudes. In this study, we utilized multi-frequency satellite microwave radiometry from the Special Sensor Microwave Imager (SSM/I) and Advanced Microwave Scanning Radiometer for EOS (AMSR-E), and SeaWinds Ku-band scatterometry to map global patterns and daily variations in terrestrial F/T cycles using a temporal change detection based classification of daily brightness temperatures and radar backscatter involving seasonal threshold and temporal edge detection algorithms. We developed a global F/T classification domain by examining biophysical cold temperature constraints to vegetation growing seasons and land cover, open water and terrain heterogeneity. We evaluated daily F/T patterns from individual sensors using various band frequencies, polarizations and AM/PM overpass data. The F/T classification accuracy was assessed relative to surface air temperatures from WMO weather stations, regional climate patterns and terrain heterogeneity. The microwave sensors produced similar F/T spatial and temporal patterns, with mean annual classification accuracy of 85 (+/-5) % relative to in situ weather station records, while global F/T time series and corresponding annual frozen/unfrozen periods were quantified over a 20 year record. These results are being used to construct a consistent, systematic long-term global record of F

  2. Optomechanics with microwave light

    Science.gov (United States)

    Lehnert, Konrad

    2009-03-01

    Recently, superconducting circuits resonant at microwave frequencies have revolutionized the measurement of astrophysical detectors [1] and superconducting qubits [2]. In this talk, I will describe how we extend this technique to measuring and manipulating nanomechanical oscillators. By strongly coupling the motion of a nanomechanical oscillator to the resonance of the microwave circuit we create structures where the dominant dissipative force acting on the oscillator is the radiation pressure of microwave ``light'' [3]. These devices are ultrasensitive force detectors and they allow us to cool the oscillator towards its motional ground state. [4pt] [1] P. K. Day et al., Nature 425, 817 (2003).[0pt] [2] A. Wallraff et al., Nature 431, 162 (2004).[0pt] [3] J. D. Teufel, J. W. Harlow, C. A. Regal and K. W. Lehnert, Phys. Rev. Lett., 101, 197203 (2008).

  3. Microwave Tokamak Experiment

    International Nuclear Information System (INIS)

    The Microwave Tokamak Experiment, now under construction at the Laboratory, will use microwave heating from a free-electron laser. The intense microwave pulses will be injected into the tokamak to realize several goals, including a demonstration of the effects of localized heat deposition within magnetically confined plasma, a better understanding of energy confinement in tokamaks, and use of the new free-electron laser technology for plasma heating. The experiment, soon to be operational, provides an opportunity to study dense plasmas heated by powers unprecedented in the electron-cyclotron frequency range required by the especially high magnetic fields used with the MTX and needed for reactors. 1 references, 5 figures, 3 tables

  4. High power microwaves

    CERN Document Server

    Benford, James; Schamiloglu, Edl

    2016-01-01

    Following in the footsteps of its popular predecessors, High Power Microwaves, Third Edition continues to provide a wide-angle, integrated view of the field of high power microwaves (HPMs). This third edition includes significant updates in every chapter as well as a new chapter on beamless systems that covers nonlinear transmission lines. Written by an experimentalist, a theorist, and an applied theorist, respectively, the book offers complementary perspectives on different source types. The authors address: * How HPM relates historically and technically to the conventional microwave field * The possible applications for HPM and the key criteria that HPM devices have to meet in order to be applied * How high power sources work, including their performance capabilities and limitations * The broad fundamental issues to be addressed in the future for a wide variety of source types The book is accessible to several audiences. Researchers currently in the field can widen their understanding of HPM. Present or pot...

  5. Medical imaging with a microwave tomographic scanner.

    Science.gov (United States)

    Jofre, L; Hawley, M S; Broquetas, A; de los Reyes, E; Ferrando, M; Elias-Fusté, A R

    1990-03-01

    A microwave tomographic scanner for biomedical applications is presented. The scanner consists of a 64 element circular array with a useful diameter of 20 cm. Electronically scanning the transmitting and receiving antennas allows multiview measurements with no mechanical movement. Imaging parameters are appropriate for medical use: a spatial resolution of 7 mm and a contrast resolution of 1% for a measurement time of 3 s. Measurements on tissue-simulating phantoms and volunteers, together with numerical simulations, are presented to assess the system for absolute imaging of tissue distribution and for differential imaging of physiological, pathological, and induced changes in tissues. PMID:2329003

  6. Microwave Drying of Paper Documents

    Czech Academy of Sciences Publication Activity Database

    Hájek, Milan

    2004. s. 79. [World Congress on Microwave and Radio Frequency Applications /4./. 07.11.2004-12.11.2004, Austin, Texas] Institutional research plan: CEZ:AV0Z4072921 Keywords : porous ceramics * microwave drying technology * microwave radiation Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  7. Microwave-assisted Chemical Transformations

    Science.gov (United States)

    In recent years, there has been a considerable interest in developing sustainable chemistries utilizing green chemistry principles. Since the first published report in 1986 by Gedye and Giguere on microwave assisted synthesis in household microwave ovens, the use of microwaves as...

  8. Microwave Imaging Equipment And Algorithms

    OpenAIRE

    Semenchik, V.; Pahomov, V.

    2004-01-01

    Microwave holographic imaging is set of methods for obtaining images of hidden objects and determining their electrical properties. The essence of these methods is image reconstruction from measurements of scattered electromagnetic field. The microwave holography is applied in medicine, industry, military, earth sciences etc. The paper presents the description of acting multifrequency microwave holographic experimental set-up.

  9. Practical microwave circuits

    CERN Document Server

    Maas, Stephen A

    2014-01-01

    This book differentiates itself by presenting microwave and RF technology from a circuit design viewpoint, rather than a set of electromagnetic problems. The emphasis is on gaining a practical understanding of often overlooked but vital physical processes.This resource provides microwave circuit engineers with analytical techniques for understanding and designing high-frequency circuits almost entirely from a circuit point of view. Electromagnetic concepts are not avoided, but they are employed only as necessary to support circuit-theoretical ones or to describe phenomena such as radiation and

  10. Fundamentals of microwave photonics

    CERN Document Server

    Urick, V J; McKinney , Jason D

    2015-01-01

    A comprehensive resource to designing andconstructing analog photonic links capable of high RFperformanceFundamentals of Microwave Photonics provides acomprehensive description of analog optical links from basicprinciples to applications.  The book is organized into fourparts. The first begins with a historical perspective of microwavephotonics, listing the advantages of fiber optic links anddelineating analog vs. digital links. The second section coversbasic principles associated with microwave photonics in both the RFand optical domains.  The third focuses on analog modulationformats-starti

  11. Microwave Frequency Polarizers

    Science.gov (United States)

    Ha, Vien The; Mirel, Paul; Kogut, Alan J.

    2013-01-01

    This article describes the fabrication and analysis of microwave frequency polarizing grids. The grids are designed to measure polarization from the cosmic microwave background. It is effective in the range of 500 to 1500 micron wavelength. It is cryogenic compatible and highly robust to high load impacts. Each grid is fabricated using an array of different assembly processes which vary in the types of tension mechanisms to the shape and size of the grids. We provide a comprehensive study on the analysis of the grids' wire heights, diameters, and spacing.

  12. Microwave Discharge Ion Sources

    CERN Document Server

    Celona, L

    2013-01-01

    This chapter describes the basic principles, design features and characteristics of microwave discharge ion sources. A suitable source for the production of intense beams for high-power accelerators must satisfy the requirements of high brightness, stability and reliability. The 2.45 GHz off-resonance microwave discharge sources are ideal devices to generate the required beams, as they produce multimilliampere beams of protons, deuterons and singly charged ions. A description of different technical designs will be given, analysing their performance, with particular attention being paid to the quality of the beam, especially in terms of its emittance.

  13. Microwave Assisted Drug Delivery

    DEFF Research Database (Denmark)

    Jónasson, Sævar Þór; Zhurbenko, Vitaliy; Johansen, Tom Keinicke

    2014-01-01

    In this work, the microwave radiation is adopted for remote activation of pharmaceutical drug capsules inside the human body in order to release drugs at a pre-determined time and location. An array of controllable transmitting sources is used to produce a constructive interference at a certain...... focus point inside the body, where the drugs are then released from the specially designed capsules. An experimental setup for microwave activation has been developed and tested on a body phantom that emulates the human torso. A design of sensitive receiving structures for integration with a drug...

  14. Urban rainfall estimation employing commercial microwave links

    Science.gov (United States)

    Overeem, Aart; Leijnse, Hidde; Uijlenhoet, Remko; ten Veldhuis, Marie-claire

    2015-04-01

    Urban areas often lack rainfall information. To increase the number of rainfall observations in cities, microwave links from operational cellular telecommunication networks may be employed. Although this new potential source of rainfall information has been shown to be promising, its quality needs to be demonstrated more extensively. In the Rain Sense kickstart project of the Amsterdam Institute for Advanced Metropolitan Solutions (AMS), sensors and citizens are preparing Amsterdam for future weather. Part of this project is rainfall estimation using new measurement techniques. Innovative sensing techniques will be utilized such as rainfall estimation from microwave links, umbrellas for weather sensing, low-cost sensors at lamp posts and in drainage pipes for water level observation. These will be combined with information provided by citizens in an active way through smartphone apps and in a passive way through social media posts (Twitter, Flickr etc.). Sensor information will be integrated, visualized and made accessible to citizens to help raise citizen awareness of urban water management challenges and promote resilience by providing information on how citizens can contribute in addressing these. Moreover, citizens and businesses can benefit from reliable weather information in planning their social and commercial activities. In the end city-wide high-resolution rainfall maps will be derived, blending rainfall information from microwave links and weather radars. This information will be used for urban water management. This presentation focuses on rainfall estimation from commercial microwave links. Received signal levels from tens of microwave links within the Amsterdam region (roughly 1 million inhabitants) in the Netherlands are utilized to estimate rainfall with high spatial and temporal resolution. Rainfall maps will be presented and compared to a gauge-adjusted radar rainfall data set. Rainfall time series from gauge(s), radars and links will be compared.

  15. Subsurface Emission Effects in AMSR-E Measurements: Implications for Land Surface Microwave Emissivity Retrieval

    Science.gov (United States)

    Galantowicz, John F.; Moncet, Jean-Luc; Liang, Pan; Lipton, Alan E.; Uymin, Gennady; Prigent, Catherine; Grassotti, Christopher

    2011-01-01

    An analysis of land surface microwave emission time series shows that the characteristic diurnal signature associated with subsurface emission in sandy deserts carry over to arid and semi-arid region worldwide. Prior work found that diurnal variation of Special Sensor Microwave/Imager (SSM/I) brightness temperatures in deserts was small relative to International Satellite Cloud Climatology Project land surface temperature (LST) variation and that the difference varied with surface type and was largest in sand sea regions. Here we find more widespread subsurface emission effects in Advanced Microwave Scanning Radiometer-EOS (AMSR-E) measurements. The AMSR-E orbit has equator crossing times near 01:30 and 13 :30 local time, resulting in sampling when near-surface temperature gradients are likely to be large and amplifying the influence of emission depth on effective emitting temperature relative to other factors. AMSR-E measurements are also temporally coincident with Moderate Resolution Imaging Spectroradiometer (MODIS) LST measurements, eliminating time lag as a source of LST uncertainty and reducing LST errors due to undetected clouds. This paper presents monthly global emissivity and emission depth index retrievals for 2003 at 11, 19, 37, and 89 GHz from AMSR-E, MODIS, and SSM/I time series data. Retrieval model fit error, stability, self-consistency, and land surface modeling results provide evidence for the validity of the subsurface emission hypothesis and the retrieval approach. An analysis of emission depth index, emissivity, precipitation, and vegetation index seasonal trends in northern and southern Africa suggests that changes in the emission depth index may be tied to changes in land surface moisture and vegetation conditions

  16. Application of satellite microwave remote sensed brightness temperature in the regional soil moisture simulation

    Directory of Open Access Journals (Sweden)

    X. K. Shi

    2009-02-01

    Full Text Available As the satellite microwave remote sensed brightness temperature is sensitive to land surface soil moisture (SM and SM is a basic output variable in model simulation, it is of great significance to use the brightness temperature data to improve SM numerical simulation. In this paper, the theory developed by Yan et al. (2004 about the relationship between satellite microwave remote sensing polarization index and SM was used to estimate the land surface SM from AMSR-E (Advanced Microwave Scanning Radiometer – Earth Observing System brightness temperature data. With consideration of land surface soil texture, surface roughness, vegetation optical thickness, and the AMSR-E monthly SM products, the regional daily land surface SM was estimated over the eastern part of the Qinghai-Tibet Plateau. The results show that the estimated SM is lower than the ground measurements and the NCEP (American National Centers for Environmental Prediction reanalysis data at the Maqu Station (33.85° N, 102.57° E and the Tanglha Station (33.07° N, 91.94° E, but its regional distribution is reasonable and somewhat better than that from the daily AMSR-E SM product, and its temporal variation shows a quick response to the ground daily precipitations. Furthermore, in order to improve the simulating ability of the WRF (Weather Research and Forecasting model to land surface SM, the estimated SM was assimilated into the Noah land surface model by the Newtonian relaxation (NR method. The results indicate that, by fine tuning of the quality factor in NR method, the simulated SM values are improved most in desert area, followed by grassland, shrub and grass mixed zone. At temporal scale, Root Mean Square Error (RMSE values between simulated and observed SM are decreased 0.03 and 0.07 m3/m3 by using the NR method in the Maqu Station and the Tanglha Station, respectively.

  17. Rapid Frequency Scan EPR

    OpenAIRE

    Tseitlin, Mark; Rinard, George A.; Quine, Richard W.; Eaton, Sandra S.; Eaton, Gareth R.

    2011-01-01

    In rapid frequency scan EPR with triangular scans, sufficient time must be allowed to insure that the magnetization in the x,y plane decays to baseline at the end of the scan, which typically is about 5 T2 after the spins are excited. To permit relaxation of signals excited toward the extremes of the scan the total scan time required may be much longer than 5 T2. However, with periodic, saw-tooth excitation, the slow-scan EPR spectrum can be recovered by Fourier deconvolution of data recorded...

  18. Integrated Advanced Microwave Sounding Unit-A (AMSU-A). Performance Verification Report: METSAT (S/N 108) AMSU-A1 Receiver Assemblies, P/N 1356429-1 S/N F05 and P/N 1356409-1 S/N F05

    Science.gov (United States)

    Haigh, R.; Krimchansky, S. (Technical Monitor)

    2000-01-01

    This is the Performance Verification Report, METSAT (S/N 108) AMSU-A1 Receiver Assemblies P/N 1356429-1 S/N F05 and P/N 1356409-1 S/N F05, for the Integrated Advanced Microwave Sounding Unit-A (AMSU-A). The ATP for the AMSU-A Receiver Subsystem, AE-26002/6A, is prepared to describe in detail the configuration of the test setups and the procedures of the tests to verify that the receiver subsystem meets the specifications as required either in the AMSU-A Instrument Performance and Operation Specifications, S-480-80, or in AMSU-A Receiver Subsystem Specifications, AE-26608, derived by the Aerojet System Engineering. Test results that verify the conformance to the specifications demonstrate the acceptability of that particular receiver subsystem.

  19. A review of applications of microwave radiometry to oceanography

    Science.gov (United States)

    Wilheit, T. T., Jr.

    1978-01-01

    Following a review of the essential physics of microwave radiative transfer, oceanographic applications of this background physics are discussed using data from electrically scanning microwave radiometers on the Nimbus 5 and 6 satellites operating at 1.55-cm and 8-mm wavelengths, respectively. These data are interpreted in terms of rain rate, ice coverage, and first-year versus multiyear ice determination. It is shown that multifrequency radiometer measurements make it possible to separate the surface and atmospheric effects and to obtain useful measurements of sea surface temperature, surface wind speed, and atmospheric parameters along with improved measurements of rain and ice.

  20. Zirconium diboride nanofiber generation via microwave arc heating

    International Nuclear Information System (INIS)

    Ultrahigh temperature zirconium diboride nanofibers were produced by microwave arc heating using micron-sized raw powder. While microwave heating the ZrB2 powder, the development of local arcing led to rapid heating and solidification of the samples, along with the creation of nanofibers. The morphology of these high aspect ratio nanofibers was characterized using scanning electron microscopy and transmission electron microscopy. Energy dispersive x-ray spectroscopy, electron energy loss spectroscopy and selected area electron diffraction showed the composition to contain zirconium, boron, nitrogen, aluminum and oxygen as well as the crystallographic orientation. ZrB2 nanofiber applications include aerospace and other harsh environments

  1. Zirconium diboride nanofiber generation via microwave arc heating

    Science.gov (United States)

    Baldridge, Tyson; Gupta, Mool C.

    2008-07-01

    Ultrahigh temperature zirconium diboride nanofibers were produced by microwave arc heating using micron-sized raw powder. While microwave heating the ZrB2 powder, the development of local arcing led to rapid heating and solidification of the samples, along with the creation of nanofibers. The morphology of these high aspect ratio nanofibers was characterized using scanning electron microscopy and transmission electron microscopy. Energy dispersive x-ray spectroscopy, electron energy loss spectroscopy and selected area electron diffraction showed the composition to contain zirconium, boron, nitrogen, aluminum and oxygen as well as the crystallographic orientation. ZrB2 nanofiber applications include aerospace and other harsh environments.

  2. Hyperspectral Microwave Atmospheric Sounder (HyMAS) Architecture and Design Accommodations

    Science.gov (United States)

    Hilliard, Lawrence; Racette, Paul; Blackwell, William; Galbraith, Christopher; Thompson, Erik

    2013-01-01

    The Hyperspectral Microwave Atmospheric Sounder (HyMAS) is being developed at Lincoln Laboratories and accommodated by the Goddard Space Flight Center for a flight opportunity on a NASA research aircraft. The term "hyperspectral microwave" is used to indicate an all-weather sounding that performs equivalent to hyperspectral infrared sounders in clear air with vertical resolution of approximately 1 km. Deploying the HyMAS equipped scanhead with the existing Conical Scanning Microwave Imaging Radiometer (CoSMIR) shortens the path to a flight demonstration. Hyperspectral microwave is achieved through the use of independent RF antennas that sample the volume of the Earth s atmosphere through various levels of frequencies, thereby producing a set of dense, spaced vertical weighting functions. The simulations proposed for HyMAS 118/183-GHz system should yield surface precipitation rate and water path retrievals for small hail, soft hail, or snow pellets, snow, rainwater, etc. with accuracies comparable to those of the Advanced Technology Microwave Sounder. Further improvements in retrieval methodology (for example, polarization exploitation) are expected. The CoSMIR instrument is a packaging concept re-used on HyMAS to ease the integration features of the scanhead. The HyMAS scanhead will include an ultra-compact Intermediate Frequency Processor (IFP) module that is mounted inside the door to improve thermal management. The IFP is fabricated with materials made of Low-Temperature Co-fired Ceramic (LTCC) technology integrated with detectors, amplifiers, A/D conversion and data aggregation. The IFP will put out 52 channels of 16 bit data comprised of 4-9 channel data streams for temperature profiles and 2-8 channel streams for water vapor. With the limited volume of the existing CoSMIR scanhead and new HyMAS front end components, the HyMAS team at Goddard began preliminary layout work inside the new drum. Importing and re-using models of the shell, the scan head computer

  3. Commercial microwave space power

    International Nuclear Information System (INIS)

    This paper reports on central commercial space power, generating power via large scale solar arrays, and distributing power to satellites via docking, tethering or beamed power such as microwave or laser beams, that is being investigated as a potentially advantageous alternative to present day technology where each satellite carries its own power generating capability. The cost, size and weight for electrical power service, together with overall mission requirements and flexibility are the principal selection criteria, with the case of standard solar array panels based on the satellite, as the reference point. This paper presents and investigates a current technology design point for beamed microwave commercial space power. The design point requires that 25 kW be delivered to the user load with 30% overall system efficiency. The key elements of the design point are: An efficient rectenna at the user end; a high gain, low beam width, efficient antenna at the central space power station end, a reliable and efficient cw microwave tube. Design trades to optimize the proposed near term design point and to explore characteristics of future systems were performed. Future development for making the beamed microwave space power approach more competitive against docking and tethering are discussed

  4. Microwaves in Airborne Surveillance

    Directory of Open Access Journals (Sweden)

    S. Christopher

    2013-03-01

    Full Text Available The use of microwave spectrum is widespread due to its convenience. Therefore, enormous amount of information is available in the free space channel. Obviously, mining this channel for surveillance is quite common. Airborne surveillance offers significant advantages in military operations. This paper talks of the usage of microwaves in airborne surveillance systems, in general, and in the Indian airborne early warning and control (AEW&C System, in particular. It brings out the multiple sub-systems onboard the aircraft comprising the AEW&C system and their spectral coverage. Co-location of several systems has its own problems and resolving them in terms of geometric location, frequency band and time of operation are covered. AEW&C, being an airborne system, has several other requirements  including minimal weight, volume and power considerations, lightning protection, streamlining, structural integrity, thermal management, vibration tolerance, corrosion prevention, erosion resistance, static charge discharge capability, bird strike resilience, etc. The methods adopted to cater to all these requirements in the microwave systems that are used in the AEW&C system are discussed. Paper ultimately speaks of the microwave systems that are designed and developed for the Indian AEW&C system to surmount these unusual constraints.Defence Science Journal, 2013, 63(2, pp.138-144, DOI:http://dx.doi.org/10.14429/dsj.63.4255

  5. Leakage of Microwave Ovens

    Science.gov (United States)

    Abdul-Razzaq, W.; Bushey, R.; Winn, G.

    2011-01-01

    Physics is essential for students who want to succeed in science and engineering. Excitement and interest in the content matter contribute to enhancing this success. We have developed a laboratory experiment that takes advantage of microwave ovens to demonstrate important physical concepts and increase interest in physics. This experiment…

  6. Invisible to Microwaves

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ Scientists can't yet make an invisibility cloak like the one that Harry Potter uses.But,for the first time,they've constructed a simple cloaking(1)d__that makes itself and something placed inside it invisible to microwaves.

  7. Microwave Nondestructive Testing Method

    OpenAIRE

    V. I. Gorbunov; V. A. Sutorikhin

    2012-01-01

    The processes of ultrasonic elastic wave interaction with conduction electrons in metals were investigated by a new technique- microwave (MW) sensor. The authors obtained practical application results in the nondestructive testing (NDT) of metal objects in the static and motion mode.

  8. New applications of microwave

    International Nuclear Information System (INIS)

    Interferometry and reflectometry measure phase of the transparent or the reflected wave to derive the information on plasma density. Homodyne reflectometry for an interlock and transmissiometry for sheet plasma measurements could be another class of microwave diagnostics, which does not measure the phase. (author)

  9. Local microwave background radiation

    OpenAIRE

    Soares, Domingos

    2006-01-01

    An inquiry on a possible local origin for the Microwave Background Radiation is made. Thermal MBR photons are contained in a system called {\\it magnetic bottle} which is due to Earth magnetic field and solar wind particles, mostly electrons. Observational tests are anticipated.

  10. Lung PET scan

    Science.gov (United States)

    Chest PET scan; Lung positron emission tomography; PET - chest; PET - lung; PET - tumor imaging ... A PET scan requires a small amount of tracer. The tracer is given through a vein (IV), usually on ...

  11. RBC nuclear scan

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003835.htm RBC nuclear scan To use the sharing features on this page, please enable JavaScript. An RBC nuclear scan uses small amounts of radioactive material to ...

  12. Atlas of duplex scanning

    International Nuclear Information System (INIS)

    This book presents the first atlas devoted entirely to duplex scanning. It details the uses of this important ''up-and-coming'' diagnostic tool for vascular and general surgeons and radiologists. It also covers scanning of the extremities, as well as the carotoids. The topics also covered are correlative line drawings elaborate and clarify the excellent scan images; the principles of duplex scanning or arteries and veins, techniques, and results; pictures normal anatomy; venous thromboses, arterial occlusion, true and false aneurysms, graft stenoses

  13. Summary report for the Microwave Source Working Group

    Energy Technology Data Exchange (ETDEWEB)

    Westenskow, G.A.

    1997-01-01

    This report summarizes the discussions of the Microwave Source Working Group during the Advanced Accelerator Concepts Workshop held October 13-19, 1996 in the Granlibakken Conference Center at Lake Tahoe, California. Progress on rf sources being developed for linear colliders is reviewed. Possible choices for high-power rf sources at 34 GHz and 94 GHz for future colliders are examined. 27 refs.

  14. Some applications of neural networks in microwave modeling

    Directory of Open Access Journals (Sweden)

    Milovanović Bratislav D.

    2003-01-01

    Full Text Available This paper presents some applications of neural networks in the microwave modeling. The applications are related to modeling of either passive or active structures and devices. Modeling is performed using not only simple multilayer perception network (MLP but also advanced knowledge based neural network (KBNN structures.

  15. Pulmonary ventilation/perfusion scan

    Science.gov (United States)

    V/Q scan; Ventilation/perfusion scan; Lung ventilation/perfusion scan ... A pulmonary ventilation/perfusion scan is actually two tests. They may be done separately or together. During the perfusion scan, a health ...

  16. Microwave and thermal curing of an epoxy resin for microelectronic applications

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Thermal and microwave curing of a commercial epoxy resin EO1080 are compared. • Microwave curing increases cure rate and does not adversely affect properties. • The curing of EO1080 is generally autocatalytic but deviates at high conversion. • Microwave radiation has a more complex effect on curing kinetics. - Abstract: Microwave curing of thermosetting polymers has a number of advantages to natural or thermal oven curing and is considered a cost-effective alternative. Here we present a detailed study of a commercially available epoxy resin, EO1080. Samples that are thermally cured are compared to curing using a recently developed modular microwave processing system. For commercial purposes it is crucial to demonstrate that microwave curing does not adversely affect the thermal and chemical properties of the material. Therefore, the kinetics of cure and various post cure properties of the resin are investigated. Attenuated Total Reflectance Fourier-Transform Infrared (ATR-FTIR) analysis shows no significant difference between the conventionally and microwave cured samples. Differential scanning calorimetry (DSC) is used to monitor the kinetics of the curing reaction, as well as determine the thermal and ageing properties of the material. As expected, the rate of curing is higher when using microwave energy and we attempt to quantify differences compared to conventional thermal curing. No change in glass transition temperature (Tg) is observed. For the first time, enthalpy relaxation measurements performed on conventional and microwave cured samples are reported and these indicate similar ageing properties at any given temperature under Tg

  17. Effects of microwave sintering power on microstructure, dielectric, ferroelectric and magnetic properties of bismuth ferrite ceramics

    International Nuclear Information System (INIS)

    Highlights: ► Single-phase BFO ceramics have been prepared by microwave sintering. ► The lower sintering power is benefit for the decrease of its dielectric loss and leakage. ► Pr and Ec decrease with the increase of sintering power. ► Mr and Hc increase as sintering power increases. -- Abstract: Multiferroic bismuth ferrite ceramics were fabricated via microwave sintering. The microstructure, dielectric, ferroelectric and magnetic properties of bismuth ferrite ceramics sintered at different microwave powers are characterized by X-ray diffraction, scanning electron microscope, impedance analyzers, ferroelectric test system and vibrating sample magnetometer. Bismuth ferrite ceramics sintered at 3.4 kW is single phase and has dense structure and uniform grains. The lower microwave sintering power for bismuth ferrite ceramics is benefit for the decrease of its dielectric loss. The remnant polarization and coercive electric field of bismuth ferrite ceramics decrease with the increasing of microwave sintering power. The remnant polarization and the coercive electric field of bismuth ferrite ceramics decrease simultaneously as frequency increases. The leakage current of bismuth ferrite ceramics increases with the increase of microwave sintering power. Bismuth ferrite ceramics prepared by microwave sintering exhibit typical antiferromagnetic behaviors and the remnant magnetization and coercive magnetic field increase as the microwave sintering power increases. It is inferred that the optimum microwave sintering power for bismuth ferrite ceramics is 3.4 kW

  18. Microwave and conventional preparation of Zinc borate glass: Eu{sup 3+} ion as luminescent probe

    Energy Technology Data Exchange (ETDEWEB)

    Mandal, Ashis K., E-mail: ashis@cgcri.res.in; Balaji, S., E-mail: sbalaji@cgcri.res.in; Sen, Ranjan, E-mail: rsen@cgcri.res.in

    2014-12-05

    Highlights: • IR transparent Zinc borate glass is prepared using microwave heating. • Glass transition temperature of microwave melted glass is found higher than that of glass prepared in conventional melting. • Low OH concentration in glass can be prepared in microwave heating. • We report higher reduction of Eu{sup 3+} to Eu{sup 2+} in microwave processing of Zinc borate glass. - Abstract: Transparent Zinc borate glass is melted using microwave energy as an alternative heating route to conventional resistive heating. A comparative study of the properties of the glasses prepared by both the methods is conducted by adopting X-ray diffraction (XRD), Differential scanning calorimetry (DSC), UV–VIS–NIR spectroscopy, Fourier transform infrared (FTIR) spectroscopy, Refractive Indices (RI). Amorphous nature of samples is confirmed by X-ray diffraction study. Glass transition temperature (T{sub g}) of microwave melted glass is found ∼7–9 °C higher than that of glass prepared in conventional melting. OH content is found less than 250 ppm in microwave melted glass whereas it is above 330 ppm in conventional melted glasses. Photoluminescence study of Eu{sub 2}O{sub 3} doped glass prepared in microwave heating indicates higher reduction of Eu{sup 3+} → Eu{sup 2+} than the glass melted in conventional route. Thus, microwave processing can be an alternative energy efficient, time saving, environmental friendly glass preparation method.

  19. Microwave and conventional preparation of Zinc borate glass: Eu3+ ion as luminescent probe

    International Nuclear Information System (INIS)

    Highlights: • IR transparent Zinc borate glass is prepared using microwave heating. • Glass transition temperature of microwave melted glass is found higher than that of glass prepared in conventional melting. • Low OH concentration in glass can be prepared in microwave heating. • We report higher reduction of Eu3+ to Eu2+ in microwave processing of Zinc borate glass. - Abstract: Transparent Zinc borate glass is melted using microwave energy as an alternative heating route to conventional resistive heating. A comparative study of the properties of the glasses prepared by both the methods is conducted by adopting X-ray diffraction (XRD), Differential scanning calorimetry (DSC), UV–VIS–NIR spectroscopy, Fourier transform infrared (FTIR) spectroscopy, Refractive Indices (RI). Amorphous nature of samples is confirmed by X-ray diffraction study. Glass transition temperature (Tg) of microwave melted glass is found ∼7–9 °C higher than that of glass prepared in conventional melting. OH content is found less than 250 ppm in microwave melted glass whereas it is above 330 ppm in conventional melted glasses. Photoluminescence study of Eu2O3 doped glass prepared in microwave heating indicates higher reduction of Eu3+ → Eu2+ than the glass melted in conventional route. Thus, microwave processing can be an alternative energy efficient, time saving, environmental friendly glass preparation method

  20. Microwave imaging of tissue blood content changes.

    Science.gov (United States)

    Hawley, M S; Broquetas, A; Jofre, L; Bolomey, J C; Gaboriaud, G

    1991-05-01

    Active microwave imaging gives information on the dielectric properties of of the body, allowing the collection of data that are distinct from, but complementary to, those available from other imaging methods based on different radiations. Two types of microwave imaging systems have been developed. The first is a planar system that irradiates the object with a plane wave and collects scattered phase and amplitude data at 1024 points on a parallel plane. The data can be reconstructed using a back propagation technique to give an image of the object. The second type of system is a tomographic scanner, consisting of a multiplexed 64-element circular array of waveguides. The waveguides are electronically scanned, alternately as sources and receivers, to give a complete scan of the object with no mechanical movement. A tomographic 'slice' of the object is reconstructed using spectral domain interpolation. Both systems work at 2.45 GHz with an incident power less than 1 mW cm-2 at the object and require a coupling medium (usually water) between the object and the source/receiver. Imaging parameters are appropriate for clinical use: a spatial resolution of 1 cm, measurement time of a few seconds and contrast resolution of around 1%. The effects of changes in perfusion on images of isolated animal organs are presented. Images have also been obtained, with both systems, of the internal dielectric structure of the forearm and of variations in dielectric properties due to changes of tissue blood content effected by application and release of tourniquets to the upper arm. Results show that these changes are well demonstrated by microwave imaging, and possible clinical applications are discussed. PMID:1870328

  1. Rapid frequency scan EPR.

    Science.gov (United States)

    Tseitlin, Mark; Rinard, George A; Quine, Richard W; Eaton, Sandra S; Eaton, Gareth R

    2011-08-01

    In rapid frequency scan EPR with triangular scans, sufficient time must be allowed to insure that the magnetization in the x, y plane decays to baseline at the end of the scan, which typically is about 5T(2) after the spins are excited. To permit relaxation of signals excited toward the extremes of the scan the total scan time required may be much longer than 5T(2). However, with periodic, saw-tooth excitation, the slow-scan EPR spectrum can be recovered by Fourier deconvolution of data recorded with a total scan period of 5T(2), even if some spins are excited later in the scan. This scan time is similar to polyphase excitation methods. The peak power required for either polyphase excitation or rapid frequency scans is substantially smaller than for pulsed EPR. The use of an arbitrary waveform generator (AWG) and cross loop resonator facilitated implementation of the rapid frequency scan experiments reported here. The use of constant continuous low B(1), periodic excitation waveform, and constant external magnetic field is similar to polyphase excitation, but could be implemented without the AWG that is required for polyphase excitation. PMID:21664848

  2. The Passive microwave Neural network Precipitation Retrieval (PNPR) algorithm for AMSU/MHS observations: description and application to European case studies

    Science.gov (United States)

    Sanò, P.; Panegrossi, G.; Casella, D.; Di Paola, F.; Milani, L.; Mugnai, A.; Petracca, M.; Dietrich, S.

    2015-02-01

    radiometers as they become available (such as the cross-track scanning Suomi National Polar-orbiting Partnership (NPP) Advanced Technology Microwave Sounder (ATMS)), and it is suitable for operational use as it is computationally very efficient. PNPR has been recently extended for applications to the regions of Africa and the South Atlantic, and an extended validation over these regions (using 2 yr of data acquired by the Tropical Rainfall Measuring Mission precipitation radar for comparison) is the subject of a paper in preparation. The PNPR is currently used operationally within the EUMETSAT Hydrology Satellite Application Facility (H-SAF) to provide instantaneous precipitation from passive microwave cross-track scanning radiometers. It undergoes routinely thorough extensive validation over Europe carried out by the H-SAF Precipitation Products Validation Team.

  3. Advances in the Study of Land Surface Emissivity Retrieval from Passive Microwave Remote Sensing%被动微波遥感反演地表发射率研究进展

    Institute of Scientific and Technical Information of China (English)

    吴莹; 王振会

    2012-01-01

    The microwave land surface emissivity ( MLSE ) is a very important parameter for describing the characteristics of the lands, and it is also a key factor for retrieving the parameters of land and atmosphere. Space - borne passive microwave radiometers provide direct retrieved land surface emissivity spectra with larger temporal and spatial scales compared with physical modeling simulation in that the physical modeling simulation needs plenty of parameters, but quite a few of these parameters, such as parameters of land surface and vegetation, are not available from traditional measurements. This paper systematically reviews MLSE retrieving algorithms for passive microwave remote sensing data, which include statistical approach, atmospheric radiation transfer model approach, index analysis approach, neural network approach and one - dimensionally variational analysis approach. The main advantages and limitations of these five methods are also discussed. Finally, the development tendencies of estimating MLSE by remote sensing are pointed out, such as developing algorithms of Radio Frequency Interference ( RFI) detection and correction, improving algorithms of detection of clouds and rain -affected radiances, and intensive research on microwave atmospheric radiation transfer process.%微波地表发射率是表征地表特征的重要参数,也是反演地表、大气参数的重要条件.相比较物理模型,其模拟计算需要若干输入参数,且相当一部分地表、植被特征参数很难从常规资料中获取,应用星载被动微波辐射计资料可以在更大空间和时间尺度范围内直接反演地表发射率.从目前常用的几种被动微波遥感反演方法(包括经验统计方法、辐射传输方程方法、指数分析方法、神经网络方法、一维变分方法等等)回顾了微波地表发射率反演的国内外研究进展及其研究中存在的问题,并对这些方法的优、缺点进行了评价.最后指出,今后应

  4. Line-scanning, stage scanning confocal microscope

    Science.gov (United States)

    Carucci, John A.; Stevenson, Mary; Gareau, Daniel

    2016-03-01

    We created a line-scanning, stage scanning confocal microscope as part of a new procedure: video assisted micrographic surgery (VAMS). The need for rapid pathological assessment of the tissue on the surface of skin excisions very large since there are 3.5 million new skin cancers diagnosed annually in the United States. The new design presented here is a confocal microscope without any scanning optics. Instead, a line is focused in space and the sample, which is flattened, is physically translated such that the line scans across its face in a direction perpendicular to the line its self. The line is 6mm long and the stage is capable of scanning 50 mm, hence the field of view is quite large. The theoretical diffraction-limited resolution is 0.7um lateral and 3.7um axial. However, in this preliminary report, we present initial results that are a factor of 5-7 poorer in resolution. The results are encouraging because they demonstrate that the linear array detector measures sufficient signal from fluorescently labeled tissue and also demonstrate the large field of view achievable with VAMS.

  5. MR guided spatial normalization of SPECT scans

    International Nuclear Information System (INIS)

    Full text: In SPECT population studies where magnetic resonance (MR) scans are also available, the higher resolution of the MR scans allows for an improved spatial normalization of the SPECT scans. In this approach, the SPECT images are first coregistered to their corresponding MR images by a linear (affine) transformation which is calculated using SPM's mutual information maximization algorithm. Non-linear spatial normalization maps are then computed either directly from the MR scans using SPM's built in spatial normalization algorithm, or, from segmented TI MR images using DARTEL, an advanced diffeomorphism based spatial normalization algorithm. We compare these MR based methods to standard SPECT based spatial normalization for a population of 27 fibromyalgia patients and 25 healthy controls with spin echo T1 scans. We identify significant perfusion deficits in prefrontal white matter in FM patients, with the DARTEL based spatial normalization procedure yielding stronger statistics than the standard SPECT based spatial normalization. (author)

  6. Radiation-hardened microwave communications system

    International Nuclear Information System (INIS)

    The consolidated fuel reprocessing program (CFRP) at the Oak Ridge National Laboratory (ORNL) has been developing signal transmission techniques and equipment to improve the efficiency of remote handling operations for nuclear applications. These efforts have been largely directed toward the goals of (a) remotely controlling bilateral force-reflecting servomanipulators for dexterous manipulation-based operations in remote maintenance tasks and (b) providing television viewing of the work site. In September 1987, developmental microwave transceiving hardware operating with dish antennas was demonstrated in the advanced integrated maintenance system (AIMS) facility at ORNL, successfully implementing both high-quality one-way television transmissions and simultaneous bidirectional digital control data transmissions with very low error rates. Initial test results based on digital transmission at a 1.0-Mbaud data rate indicated that the error rates of the microwave system were comparable to those of a hardwired system. During these test intervals, complex manipulator operations were performed, and the AIMS transporter was moved repeatedly without adverse effects on data integrity. Results of these tests have been factored into subsequent phases of the development program, with an ultimate goal of designing a fully radiation-hardened microwave signal transmission system for use in nuclear facilities

  7. Botswana water and surface energy balance research program. Part 2: Large scale moisture and passive microwaves

    Science.gov (United States)

    Vandegriend, A. A.; Owe, M.; Chang, A. T. C.

    1992-01-01

    The Botswana water and surface energy balance research program was developed to study and evaluate the integrated use of multispectral satellite remote sensing for monitoring the hydrological status of the Earth's surface. The research program consisted of two major, mutually related components: a surface energy balance modeling component, built around an extensive field campaign; and a passive microwave research component which consisted of a retrospective study of large scale moisture conditions and Nimbus scanning multichannel microwave radiometer microwave signatures. The integrated approach of both components are explained in general and activities performed within the passive microwave research component are summarized. The microwave theory is discussed taking into account: soil dielectric constant, emissivity, soil roughness effects, vegetation effects, optical depth, single scattering albedo, and wavelength effects. The study site is described. The soil moisture data and its processing are considered. The relation between observed large scale soil moisture and normalized brightness temperatures is discussed. Vegetation characteristics and inverse modeling of soil emissivity is considered.

  8. The Cosmic Microwave Background

    Directory of Open Access Journals (Sweden)

    Jones Aled

    1998-01-01

    Full Text Available We present a brief review of current theory and observations of the cosmic microwave background (CMB. New predictions for cosmological defect theories and an overview of the inflationary theory are discussed. Recent results from various observations of the anisotropies of the microwave background are described and a summary of the proposed experiments is presented. A new analysis technique based on Bayesian statistics that can be used to reconstruct the underlying sky fluctuations is summarised. Current CMB data is used to set some preliminary constraints on the values of fundamental cosmological parameters $Omega$ and $H_circ$ using the maximum likelihood technique. In addition, secondary anisotropies due to the Sunyaev-Zel'dovich effect are described.

  9. Advanced Virgo

    CERN Multimedia

    Virgo, a first-generation interferometric gravitational wave (GW) detector, located in the European Gravitational Observatory, EGO, Cascina (Pisa-Italy) and constructed by the collaboration of French and Italian institutes (CNRS and INFN) has successfully completed its long-duration data taking runs. It is now undergoing a fundamental upgrade that exploits available cutting edges technology to open an exciting new window on the universe, with the first detection of a gravitational wave signal. Advanced Virgo (AdV) is the project to upgrade the Virgo detector to a second-generation instrument. AdV will be able to scan a volume of the Universe 1000 times larger than initial Virgo. AdV will be hosted in the same infrastructures as Virgo. The Advanced VIRGO project is funded and at present carried on by a larger collaboration of institutes belonging to CNRS- France , RMKI - Hungary, INFN- Italy, Nikhef - The Netherlands Polish Academy of Science - Poland.

  10. Present and future applications of analogue microwave photonics

    DEFF Research Database (Denmark)

    Tafur Monroy, Idelfonso

    2009-01-01

    will introduce present and emerging opportunities for analog photonics, among which microwave filters, arbitrary optical waveform control, THz radiation and UWB pulse generation. A panel discussion will contrast different views from company, academy and funding bodies, to identify the most promising......Photonics may be even more suited for analog than for digital signal applications. Today, microwave photonics techniques are currently used in radio-over-fibre signal transmission and other commercial applications, but recent advances are widening the scope of application to new areas. The speakers...

  11. Microwave Ablation of Hepatic Malignancy

    OpenAIRE

    Lubner, Meghan G.; Brace, Christopher L.; Ziemlewicz, Tim J.; Hinshaw, J. Louis; Lee, Fred. T.

    2013-01-01

    Microwave ablation is an extremely promising heat-based thermal ablation modality that has particular applicability in treating hepatic malignancies. Microwaves can generate very high temperatures in very short time periods, potentially leading to improved treatment efficiency and larger ablation zones. As the available technology continues to improve, microwave ablation is emerging as a valuable alternative to radiofrequency ablation in the treatment of hepatic malignancies. This article rev...

  12. Microwave imaging for security applications

    OpenAIRE

    Almazroui, Sultan

    2015-01-01

    Microwave imaging technologies have been widely researched in the biomedical field where they rely on the imaging of dielectric properties of tissues. Healthy and malignant tissue have different dielectric properties in the microwave frequency region, therefore, the dielectric properties of a human body’s tissues are generally different from other contraband materials. Consequently, dielectric data analysis techniques using microwave signals can be used to distinguish between different types ...

  13. Ice Water Path Retrieval Using Microwave and Submillimetre Wave Observations

    Science.gov (United States)

    Brath, Manfred; Grützun, Verena; Mendrok, Jana; Fox, Stuart; Eriksson, Patrick; Buehler, Stefan A.

    2016-04-01

    There is an ongoing need for data on ice clouds. The ice water path as an essential climate variable is a fundamental parameter to describe ice clouds. Combined passive microwave and submillimetre wave measurements are capable to sample the size distribution of the ice particles and are sensitive to relevant particle sizes. This makes combined microwave and submillimetre wave measurements useful for estimates of ice water path. Furthermore, instead of being sensitive for the upper ice column as for example for passive visible and passive infrared measurements, combined microwave and submillimetre wave measurements can sample the full ice column. We developed a retrieval algorithm for ice water path based on a neural network approach using combined microwave and submillimetre wave measurements, from about 20 channels in the range between 89 GHz and 664 GHz of the electromagnetic sprectra. We trained a neural network by using 1D radiative transfer simulations which were conducted using the Atmospheric Radiative Transfer Simulator (ARTS). The radiative transfer simulations were fed by atmospheric profiles from a numerical weather prediction model. We will present an analysis of the retrieval. Additionally, we will present results of retrieved IWP from combined ISMAR (International SubMillimetre Airborne Radiometer) and MARSS (Microwave Airborne Radiometer Scanning System) measurements on board of the Facility for Airborne Atmospheric Measurements (FAAM) aircraft during March 2015 over the North Atlantic.

  14. Characterization of thermoplastic polymer welding done with microwaves

    International Nuclear Information System (INIS)

    Thermoplastic polymer materials and the compounds made with them are being used more frequently for industrial components and for general use. However, the application of these materials for the production of complex shaped or relatively large pieces is limited, because of the difficulty and cost of making the necessary tool kit for the job. One solution is the use of the welding process. But the safe and reliable union of different thermoplastic material parts is not a simple process, even less so in the case of unions of large components. Welding by microwaves using polymer conductors can help, since the large scale equipment is available, and methods for continuous processes by microwave have been developed, that can be used to weld large and small components. Many thermoplastics (ex. polyethylene) do not absorb, or absorb very little, energy from microwaves. Polymer conductors, however, heavily absorb from microwaves with the consequent heating. Therefore the welding zone can be heated without affecting the rest of the piece. This work describes the welding zone of thermoplastic polymers, in order to learn more about the phenomena that occurs in this zone and to relate the structure of the base materials with those of the welding. The welding used an intrinsically conductor polymer: polyaniline (PANI), using microwave energy for the remote, localized heating of the welding. The tools used for the characterization were: Scanning Electron Microscopy (SEM) and X-ray diffraction (XRD). The results of this study yielded data that can improve the quality of the welding of thermoplastic materials (CW)

  15. High-sensitivity broadband microwave spectroscopy with small nonresonant coils

    Science.gov (United States)

    Mahdjour, H.; Clark, W. G.; Baberschke, K.

    1986-06-01

    The use of a small, nonresonant, coil of micron dimensions as the microwave magnetic field structure of a broadband electron-spin-resonance (ESR) spectrometer is described. The coil is driven by a broadband microwave generator which operates between 0.1 and 8.5 GHz. The samples may fill the coil to approximately 100 percent. It is shown that for small size samples this system offers higher sensitivity than a conventional cavity spectrometer. Because the system is broadband, either frequency scans or the conventional magnetic field scans can be used to traverse the resonance. Examples for DPPH and for the spin glass AgMn using this method are reported. Since the sample coil is small, it has many potential applications, such as insertion into the mixing chamber of dilution refrigerator or high-pressure cell, efficient use of power in ENDOR and other double resonance experiments, and rapid recovery from transients in pulsed ESR experiments.

  16. An introduction to microwave measurements

    CERN Document Server

    Basu, Ananjan

    2014-01-01

    IntroductionAim and ScopeGeneral Electronic Measurements and Frequency LimitationsApplications and Importance of Microwave MeasurementsOverview of State-of-the-Art Microwave MeasurementsReferencesBackground InformationS-Parameters and Related Black-Box RepresentationSpectra of Commonly Encountered SignalsMicrowave Filters and Directional CouplersMicrowave Mixers, Switches, Attenuators, and ConnectorsConclusionProblemsReferencesTraditional Measurement TechniquesThe Power MeterTransmission MeasurementReflection MeasurementConclusionProblemsReferencesVector Network AnalyzerEnhancement of Scalar M

  17. Aperture synthesis concepts in microwave remote sensing of the earth

    Science.gov (United States)

    Swift, Calvin T.; Le Vine, David M.; Ruf, Christopher S.

    1991-01-01

    The application of aperture synthesis concepts, used for many years in radio astronomy to achieve high image resolution at a reasonable cost, to remote sensing technology is discussed. The electronically scanned thinned array radiometer (ESTAR) is put forward as a viable alternative to improve spatial resolution by an order of magnitude over what is presently achieved by microwave imaging systems that are collecting data from earth orbit. Future developments in airborne sensor technology and potential spacecraft application are described.

  18. Ultrasonic characterization of microwave joined silicon carbide/silicon carbide

    International Nuclear Information System (INIS)

    High frequency (50--150 MHz), ultrasonic immersion testing has been used to characterize the surface and interfacial joint conditions of microwave bonded, monolithic silicon carbide (SiC) materials. The high resolution ultrasonic C-scan images point to damage accumulation after thermal cycling. Image processing was used to study the effects of the thermal cycling on waveform shape, amplitude and distribution. Such information is useful for concurrently engineering material fabrication processes and suitable nondestructive test procedures

  19. The synthetic aperture method in the environment microwave interferometer radiometry

    OpenAIRE

    Kutuza, B.G.; Zagorin, G. K.

    2003-01-01

    The basic principles of space-borne two dimensional synthetic aperture microwave polarimetric interferometer function are considered. The main advantages of these systems over the well-known systems ESMR, SMMR and SSM/I are: a high rate of the observation scene image construction; the finite angular resolution; besides, they have no movable onboard construction elements on the spacecraft board, like the scanning antenna, and etc. The advantages of the synthetic aperture systems with hexagonal...

  20. Microwave Plasma System: PVA Tepla 300

    Data.gov (United States)

    Federal Laboratory Consortium — Description: CORAL Name: Microwave Asher A tool using microwave oxygen plasma to remove organics on the surfaces Specifications / Capabilities: Frequency: 2.45 GHz...

  1. Getting a CAT Scan

    Medline Plus

    Full Text Available ... Snowboarding, Skating Crushes What's a Booger? Getting a CAT Scan (Video) KidsHealth > For Kids > Getting a CAT Scan (Video) Print A A A Text Size en español Obtención de una tomografía computada (video) CAT stands for "computerized axial tomography." Translated, that means ...

  2. Getting a CAT Scan

    Medline Plus

    Full Text Available ... Here's Help White House Lunch Recipes Getting a CAT Scan (Video) KidsHealth > For Kids > Getting a CAT Scan (Video) Print A A A Text Size en español Obtención de una tomografía computada (video) CAT stands for "computerized axial tomography." Translated, that means ...

  3. Abdominal CT scan

    Science.gov (United States)

    ... than regular x-rays. Many x-rays or CT scans over time may increase your risk for cancer. However, the risk from any one scan is small. Talk to your doctor about this risk and the benefit of the test for getting a correct diagnosis ...

  4. Knee CT scan

    Science.gov (United States)

    Risks of CT scans include: Exposure to radiation Allergy to contrast dye CT scans give off more radiation than ... injected contrast dye. The most common type of contrast contains ... you have this an iodine allergy. If you need to have this kind of ...

  5. Knee CT scan

    Science.gov (United States)

    A computed tomography (CT) scan of the knee is a test that uses x-rays to take detailed images of the knee. ... A CT scan can quickly create more detailed pictures of the knee than standard x-rays. The test may be ...

  6. Frequency scanning microstrip antennas

    DEFF Research Database (Denmark)

    Danielsen, Magnus; Jørgensen, Rolf

    1979-01-01

    The principles of using radiating microstrip resonators as elements in a frequency scanning antenna array are described. The resonators are cascade-coupled. This gives a scan of the main lobe due to the phase-shift in the resonator in addition to that created by the transmission line phase...

  7. Environmental Scanning Report.

    Science.gov (United States)

    Truckee Meadows Community Coll., Sparks, NV.

    This report describes Truckee Meadows Community College's (Nevada) environmental scanning process and results. The college decided that environmental scanning and forecasting techniques should be used to plan for both short-term and long-term external factors that impact programs, enrollment, and budgets. Strategic goals include: (1) keeping pace…

  8. Getting a CAT Scan

    Medline Plus

    Full Text Available ... Dictionary of Medical Words En Español What Other Kids Are Reading Movie: Digestive System Winter Sports: Sledding, ... Booger? Getting a CAT Scan (Video) KidsHealth > For Kids > Getting a CAT Scan (Video) Print A A ...

  9. Getting a CAT Scan

    Medline Plus

    Full Text Available ... Skiing, Snowboarding, Skating Crushes What's a Booger? Getting a CAT Scan (Video) KidsHealth > For Kids > Getting a CAT Scan (Video) Print A A A Text Size en español Obtención de ...

  10. Getting a CAT Scan

    Medline Plus

    Full Text Available ... Crushes What's a Booger? Getting a CAT Scan (Video) KidsHealth > For Kids > Getting a CAT Scan (Video) Print A A A Text Size en español Obtención de una tomografía computada (video) CAT stands for "computerized axial tomography." Translated, that ...

  11. Effect of Microwave Treatment Upon Processing Oolitic High Phosphorus Iron Ore for Phosphorus Removal

    Science.gov (United States)

    Tang, Hui-Qing; Liu, Wei-Di; Zhang, Huan-Yu; Guo, Zhan-Cheng

    2014-10-01

    Influence of microwave treatment on the previously proposed phosphorus removal process of oolitic high phosphorus iron ore (gaseous reduction followed by melting separation) has been studied. Microwave treatment was carried out using a high-temperature microwave reactor (Model: MS-WH). Untreated ore fines and microwaved ore fines were then characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and thermogravimetric analysis (TGA). Thereafter, experiments on the proposed phosphorus removal process were conducted to examine the effect of microwave treatment. Results show that microwave treatment could change the microstructure of the ore fines and has an intensification effect on its gaseous reduction by reducing gas internal resistance, increasing chemical reaction rate and postponing the occurrence of sintering. Results of gaseous reduction tests using tubular furnace indicate both microwave treatment and high reduction temperature high as 1273 K (1000 °C) are needed to totally break down the dense oolite and metallization rate of the ore fines treated using microwave power of 450 W could reach 90 pct under 1273 K (1000 °C) and for 2 hours. Results of melting separation tests of the reduced ore fines with a metallization rate of 90 pct show that, in addition to the melting conditions in our previous studies, introducing 3 pct Na2CO3 to the highly reduced ore fines is necessary, and metal recovery rate and phosphorus content of metal could reach 83 pct and 0.31 mass pct, respectively.

  12. Radiation Processing of Advanced Composite Materials

    International Nuclear Information System (INIS)

    Advanced composites, such as carbon-fiber-reinforced plastics, are being used widely for many applications. Carbon fiber/epoxies composites have attracted special attention from the aircraft, aerospace, marine engineering, sporting goods and transportation industries, because they have useful mechanical properties including high strength-to-weight and stiffness-to-weight ratios, a corrosion resistant, impact and damage tolerance characteristics and wear properties. Thermal curing has been the dominant industrial process for advanced composites until now, however, a radiation curing process using UV, microwave x-ray, electron-beam(E-beam) and γ-ray has emerged as a better alternative in recent years. These processes are compatible with the manufacturing of composites using traditional fabrication methods including a filament/tape winding, pultrusion, resin transfer moulding and hand lay-up. In this study, E-beam curable carbon fiber/epoxy composites were manufactured, and their mechanical properties were investigated. Two epoxy resins (bisphenol-A, bisphenol-F) containing photo-initiators (tri aryl sulfonium hexafluorophosphate, tri aryl sulfonium hexafluoroantimonate) were used as a matrix and a 4H-satin carbon woven fabric was used as a reinforcement. And then an electron beam irradiated the composites up to 200 kGy in a vacuum and an inert atmosphere. The cure cycle was optimized and the properties of composites were evaluated and analyzed via a differential scanning calorimetry, scanning electron microscopy, sol-gel extractions, FT-NIR, universal test machine, and an impact tester. The gel content, glass transition temperature and mechanical strength of the irradiated composites were increased with an increasing radiation dose

  13. Assimilation of space-based passive microwave soil moisture retrievals and the correction for a dynamic open water fraction

    Directory of Open Access Journals (Sweden)

    B. T. Gouweleeuw

    2012-01-01

    Full Text Available The large observation footprint of low-frequency satellite microwave emissions complicates the interpretation of near-surface soil moisture retrievals. While the effect of sub-footprint lateral heterogeneity is relatively limited under unsaturated conditions, open water bodies, if not accounted for, cause a strong positive bias in the satellite-derived soil moisture retrieval. This bias is generally assumed static and associated with large, continental lakes and coastal areas. Temporal changes in the extent of smaller water bodies as small as a few percent of the sensor footprint size, however, can cause significant and dynamic biases. We analysed the influence of such small open water bodies near-surface soil moisture retrieval data from the Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E for three areas in Oklahoma, USA. Differences between on-ground observations, model estimates and AMSR-E retrievals were compared to dynamic estimates of open water fraction, one retrieved from a global daily record based on higher frequency AMSR-E data and another derived from the Moderate Resolution Imaging Spectroradiometer (MODIS. The comparisons demonstrates that seasonally varying biases of up to 30 vol.% soil water content can be attributed to the presence of relatively small areas (<5% of open water in or near the sensor footprint. These errors need to be addressed, either through elimination or accurate characterization, if the soil moisture retrievals are to be used effectively in a data assimilation scheme.

  14. Detection and characterization of drizzle cells within marine stratocumulus using AMSR-E 89 GHz passive microwave measurements

    Directory of Open Access Journals (Sweden)

    M. A. Miller

    2012-07-01

    Full Text Available This empirical study demonstrates the feasibility of using 89 GHz Advanced Microwave Scanning Radiometer – Earth Observing System (AMSR-E passive microwave brightness temperature data to detect heavily drizzling cells within marine stratocumulus. A binary heavy drizzle product is described that can be used to determine areal and feature statistics of drizzle cells within the major marine stratocumulus regions. Current satellite liquid water path (LWP and cloud radar products capable of detecting drizzle are either lacking in resolution (AMSR-E LWP, diurnal coverage (MODIS LWP, or spatial coverage (CloudSat. The AMSR-E 89 GHz data set at 6 × 4 km spatial resolution is sufficient for resolving individual heavily drizzling cells. Radiant emission at 89 GHz by liquid-water cloud and precipitation particles from drizzling cells in marine stratocumulus regions yields local maxima in brightness temperature against an otherwise cloud-free background brightness temperature. The background brightness temperature is primarily constrained by column-integrated water vapor and sea surface temperature. Clouds containing ice are screened out. Once heavily drizzling pixels are identified, connected pixels are grouped into discrete drizzle cell features. The identified drizzle cells are used in turn to determine several spatial statistics for each satellite scene, including drizzle cell number and size distribution. The identification of heavily drizzling cells within marine stratocumulus regions with satellite data facilitates analysis of seasonal and regional drizzle cell occurrence and the interrelation between drizzle and changes in cloud fraction.

  15. Spaceborne Microwave Instrument for High Resolution Remote Sensing of the Earth's Surface Using a Large-Aperture Mesh Antenna

    Science.gov (United States)

    Njoku, E.; Wilson, W.; Yueh, S.; Freeland, R.; Helms, R.; Edelstein, W.; Sadowy, G.; Farra, D.; West, R.; Oxnevad, K.

    2001-01-01

    This report describes a two-year study of a large-aperture, lightweight, deployable mesh antenna system for radiometer and radar remote sensing of the Earth from space. The study focused specifically on an instrument to measure ocean salinity and Soil moisture. Measurements of ocean salinity and soil moisture are of critical . importance in improving knowledge and prediction of key ocean and land surface processes, but are not currently obtainable from space. A mission using this instrument would be the first demonstration of deployable mesh antenna technology for remote sensing and could lead to potential applications in other remote sensing disciplines that require high spatial resolution measurements. The study concept features a rotating 6-m-diameter deployable mesh antenna, with radiometer and radar sensors, to measure microwave emission and backscatter from the Earth's surface. The sensors operate at L and S bands, with multiple polarizations and a constant look angle, scanning across a wide swath. The study included detailed analyses of science requirements, reflector and feedhorn design and performance, microwave emissivity measurements of mesh samples, design and test of lightweight radar electronic., launch vehicle accommodations, rotational dynamics simulations, and an analysis of attitude control issues associated with the antenna and spacecraft, The goal of the study was to advance the technology readiness of the overall concept to a level appropriate for an Earth science emission.

  16. A fast map-making preconditioner for regular scanning patterns

    Energy Technology Data Exchange (ETDEWEB)

    Næss, Sigurd K.; Louis, Thibaut, E-mail: sigurd.naess@astro.ox.ac.uk, E-mail: thibaut.louis@astro.ox.ac.uk [Sub-department of Astrophysics, University of Oxford, Keble Road, Oxford, OX1 3RH (United Kingdom)

    2014-08-01

    High-resolution Maximum Likelihood map-making of the Cosmic Microwave Background is usually performed using Conjugate Gradients with a preconditioner that ignores noise correlations. We here present a new preconditioner that approximates the map noise covariance as circulant, and show that this results in a speedup of up to 400% for a realistic scanning pattern from the Atacama Cosmology Telescope. The improvement is especially large for polarized maps.

  17. Fluctuation Dominated Josephson Tunneling with a Scanning Tunneling Microscope

    OpenAIRE

    Naaman, O.; Teizer, W.; Dynes, R. C.

    2001-01-01

    We demonstrate Josephson tunneling in vacuum tunnel junctions formed between a superconducting scanning tunneling microscope tip and a Pb film, for junction resistances in the range 50-300 k$\\Omega$. We show that the superconducting phase dynamics is dominated by thermal fluctuations, and that the Josephson current appears as a peak centered at small finite voltages. In the presence of microwave fields (f=15.0 GHz) the peak decreases in magnitude and shifts to higher voltages with increasing ...

  18. A fast map-making preconditioner for regular scanning patterns

    International Nuclear Information System (INIS)

    High-resolution Maximum Likelihood map-making of the Cosmic Microwave Background is usually performed using Conjugate Gradients with a preconditioner that ignores noise correlations. We here present a new preconditioner that approximates the map noise covariance as circulant, and show that this results in a speedup of up to 400% for a realistic scanning pattern from the Atacama Cosmology Telescope. The improvement is especially large for polarized maps

  19. A fast map-making preconditioner for regular scanning patterns

    CERN Document Server

    Næss, Sigurd

    2013-01-01

    High-resolution Maximum Likelihood map-making of the Cosmic Microwave Background is usually performed using Conjugate Gradients with a preconditioner that ignores noise correlations. We here present a new preconditioner that approximates the map noise covariance as circulant, and show that this results in a speedup of up to 400% for a realistic scanning pattern from the Atacama Cosmology Telescope. The improvement is especially large for polarized maps.

  20. Microwave Magnetoelectric Devices

    OpenAIRE

    Tatarenko, A. S.; Bichurin, M. I.

    2012-01-01

    Tunable microwave magnetoelectric devices based on layered ferrite-ferroelectric structures are described. The theory and experiment for attenuator, band-pass filter and phase shifter are presented. Tunability of the ME devices characteristics can be executed by application of an electric field. This electric tuning is relatively fast and is not power-consuming. The attenuator insertion losses vary from 26 dB to 2 dB at frequency 7251 MHz. The tuning range of 25 MHz of band-pass filter at fre...

  1. Longitudinal microwave instability

    International Nuclear Information System (INIS)

    A derivation of the relationship between growth rate and impedance is given. The only other instability considered here is the resonance effect produced by excessive tune shift due to space charge. We assume, without discussion, the (Δν)/sub max/ = .25; that is, this resonance growth is avoided (stability) by limiting the ring charge. On the other hand, the longitudinal microwave instability is assumed to be present (cannot be stabilized). Thus, the latter involves a limiting impedance to keep the growth rate low enough. The maximum allowed impedance for a maximum allowed growth rate is listed

  2. DSN Microwave Antenna Holography

    Science.gov (United States)

    Rochblatt, D. J.; Seidel, B. L.

    1984-01-01

    The DSN microwave antenna holography project will obtain three-dimensional pictures of the large DSN antenna surfaces. These pictures must be of suffi icient resolution to allow adjustment of the reflector panels to an rms surface of 0.5 mm (0.25 mm, goal). The major parameters and equations needed to define a holographic measurement system are outlined and then the proof of concept demonstration measurement that was made at DSS-43 (Australia) that resulted in contour maps with spatial resolution of 7 m in the aperture plane and resolution orthogonal to the aperture plane of 0.7 mm was discussed.

  3. Resonant freak microwaves

    International Nuclear Information System (INIS)

    The Helmholtz equation describing transverse magnetic modes in a closed flat microwave resonator with 60 randomly distributed discs is numerically solved. At lower frequencies, the calculated wave intensity spatially distributed obeys the universal Porter-Thomas form if localized modes are excluded. A superposition of resonant modes is shown to lead to rare events of extreme intensities (freak waves) at localized 'hot spots'. The temporally distributed intensity of such a superposition at the center of a hot spot also follows the Porter-Thomas form. Branched modes are found at higher frequencies. The results bear resemblance to recent experiments reported in an open cavity.

  4. Microwave Drying of Paper Documents

    Czech Academy of Sciences Publication Activity Database

    Hájek, Milan

    2004. s. 1. [International Conference on Heating by Electromagnetic Sources. 22.09.2004-27.09.2004, Padua] Institutional research plan: CEZ:AV0Z4072921 Keywords : microwave drying technology * porous ceramics * microwave radiation Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  5. Microwave Drying of Paper Documents

    Czech Academy of Sciences Publication Activity Database

    Hájek, Milan

    2004. s. 101. [Innovative Applikationen der Mikrowellentechnologie in der Oberlaisitz. 05.05.2004, Zittau] R&D Projects: GA AV ČR IBS4072306 Institutional research plan: CEZ:AV0Z4072921 Keywords : porous ceramics * microwave drying technology * microwave radiation Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  6. PROGRAMMING THE MICROWAVE-OVEN

    NARCIS (Netherlands)

    KOK, LP; VISSER, PE; BOON, ME

    1994-01-01

    Microwaves can be used to stimulate chemical bonding, diffusion of reagents into and out of the specimen, and coagulation processes in preparatory techniques. Temperature plays an important role in these processes. There are several ways of controlling the temperature of microwave-exposed tissue, fl

  7. Microwave Radiometry in Remote Sensing

    DEFF Research Database (Denmark)

    Gudmandsen, Preben

    1982-01-01

    Microwave radiometry has shown its capabilities of observing and monitoring large-scale geophysical observables from space. Examples are sea surface temperature and surface wind over the ocean, sea ice extent, concentration and category and snow cover extent and water content. At low microwave fr...

  8. Computer-Generated Microwave Holograms.

    Science.gov (United States)

    Leming, Charles W.; Hastings, Orestes Patterson, III

    1980-01-01

    Described is the phasor method of superposition of waves. The intensity pattern from a system of microwave sources is calculated point by point on a plane corresponding to a film emulsion, and then printed and directly converted to a hologram for 3-cm microwaves. Calculations, construction, and viewing of holograms are included. (Author/DS)

  9. The extension of the split window technique to passive microwave surface temperature assessment

    International Nuclear Information System (INIS)

    The theoretical study of both land and sea surface temperature remote sensing is treated through investigating the extension to the microwave region (1-100GHz) of the split window technique, usually used in the thermal infrared region for sea surface temperature measurements. The study of land surface temperature shows that, in both regions (infrared and microwave), the influence (of atmospheric water vapor content and surface emissivity) is critical. The theory is based on the Radiative Transfer Equation, which assumed solutions can be given in both spectral regions, with respect to Wien's and Rayleigh-Jean's laws, respectively. The surface temperature determination is studied in connection with the surface emissivity in both infrared and microwave regions determined with an iterative process. Infrared data is provided by the sensor Advanced Very High Resolution Radiometer (AVHRR) and microwave data by Special Sensor Microwave/Imager (SSM/I), through the WETNET program, directed by NASA/HQS. (author)

  10. Scanning probe – atomic force microscopy: new developments and applications

    International Nuclear Information System (INIS)

    Recent developments in scanning probe microscopy (SPM) have widened the spectrum of possible investigations that can be performed at a nanometric level at the surfaces of materials. They range, for instance, from physical properties such as surface potential and electric field topological determination to chemical, nanomechanical, catalytic and spectroscopic analysis in air in liquid or in a gaseous environment. After a brief introduction to new SPM technological developments, we present recent achievements in the characterisation and application of nanomorphology, electrostatic surface potential, dielectric properties, shear force microscopy and radiofrequency measurements, scanning microwave microscopy, nanomechanical properties mapping, frequency modulation SPM in air, liquid, vacuum, and finally high-speed SPM

  11. Noncontact dimensional measurement system using holographic scanning

    Science.gov (United States)

    Sagan, Stephen F.; Rosso, Robert S.; Rowe, David M.

    1997-07-01

    Holographic scanning systems have been used for years in point-of-sale bar code scanners and other low resolution applications. These simple scanning systems could not successfully provide the accuracy and precision required to measure, inspect and control the production of today's high tech optical fibers, medical extrusions and electrical cables. A new class of instruments for the precision measurement of industrial processes has been created by the development of systems with a unique combination of holographic optical elements that can compensate for the wavelength drift in laser diodes, the application of proprietary post-processing algorithms, and the advancements in replication methods to fabricate low cost holographic scanning discs. These systems have improved upon the performance of traditional polygon mirror scanners. This paper presents the optical configuration and design features that have been incorporated into a holographic scanning inspection system that provides higher productivity, increased product quality and lower production costs for many manufacturers.

  12. Electron Beam Scanning in Industrial Applications

    Science.gov (United States)

    Jongen, Yves; Herer, Arnold

    1996-05-01

    Scanned electron beams are used within many industries for applications such as sterilization of medical disposables, crosslinking of wire and cables insulating jackets, polymerization and degradation of resins and biomaterials, modification of semiconductors, coloration of gemstones and glasses, removal of oxides from coal plant flue gasses, and the curing of advanced composites and other molded forms. X-rays generated from scanned electron beams make yet other applications, such as food irradiation, viable. Typical accelerators for these applications range in beam energy from 0.5MeV to 10 MeV, with beam powers between 5 to 500kW and scanning widths between 20 and 300 cm. Since precise control of dose delivery is required in many of these applications, the integration of beam characteristics, product conveyance, and beam scanning mechanisms must be well understood and optimized. Fundamental issues and some case examples are presented.

  13. Microwave-Accelerated Organic Reactions

    Institute of Scientific and Technical Information of China (English)

    LU; TaJung

    2001-01-01

    The use of microwave technology in accelerating organic reactions has received intense attention leading to immense growth recently. Accordingly, we have been interested in improving the efficacy of organic processes by microwave irradiation. Here we report our results on the microwave assisted 1,3-dipolar cycloaddition reaction of nitrile oxides with allylic alcohols, the cleavage reaction of 1,3-diketones under alkaline conditions, and the formation of carbamates from isocyanates with alcohols. The reactions carried out under microwave irradiation, in general, required considerably less reaction time and afforded the desired products in higher yields than those under classical conditions. In all the cases we have studied, the procedures are simplified, the purity of the products are higher, and the cost of reaction is greatly reduced employing microwave.  ……

  14. Microwave-Accelerated Organic Reactions

    Institute of Scientific and Technical Information of China (English)

    LU TaJung

    2001-01-01

    @@ The use of microwave technology in accelerating organic reactions has received intense attention leading to immense growth recently. Accordingly, we have been interested in improving the efficacy of organic processes by microwave irradiation. Here we report our results on the microwave assisted 1,3-dipolar cycloaddition reaction of nitrile oxides with allylic alcohols, the cleavage reaction of 1,3-diketones under alkaline conditions, and the formation of carbamates from isocyanates with alcohols. The reactions carried out under microwave irradiation, in general, required considerably less reaction time and afforded the desired products in higher yields than those under classical conditions. In all the cases we have studied, the procedures are simplified, the purity of the products are higher, and the cost of reaction is greatly reduced employing microwave.

  15. Pulse modulated microwave plasma etching

    International Nuclear Information System (INIS)

    The authors report the etching characteristics of silicon and silicon dioxide studied in an anisotropic microwave plasma etching system having a variably pulsed microwave source. Pulse frequency, as well as pulse duty cycle, can be varied on the microwave source. Earlier work done in isotropic rf systems suggests that etch rate and quality may be affected positively by pulse modulation. Electron-cyclotron resonance heating is used so that the process gas (sulfur hexafluoride) can be more efficiently ionized, with the resulting ions and free radicals from the plasma then etching the silicon substrate or the silicon dioxide on the substrate. Characteristics being examined include etch rate, etch anisotropy, and etching selectivity between silicon and silicon dioxide. The design of the microwave plasma etching system, including the variable pulsed microwave source, are presented along with preliminary results

  16. Emerging Trends in Microwave Processing of Spices and Herbs.

    Science.gov (United States)

    Rahath Kubra, Ismail; Kumar, Devender; Jagan Mohan Rao, Lingamallu

    2016-10-01

    Today, spices are integral part of our food as they provide sensory attributes such as aroma, color, flavour and taste to food. Further their antimicrobial, antioxidant, pharmaceutical and nutritional properties are also well known. Since spices are seasonal so their availability can be extended year round by adopting different preservation techniques. Drying and extraction are most important methods for preservation and value addition to spices. There are different techniques for drying of spices with their own advantages and limitations. A novel, non-conventional technique for drying of spices is use of microwave radiation. This technique proved to be very rapid, and also provide a good quality product. Similarly, there are a number of non-conventional extraction methods in use that are all, in principle, solid-liquid extractions but which introduce some form of additional energy to the process in order to facilitate the transfer of analytes from sample to solvent. This paper reviews latest advances in the use of microwave energy for drying of spices and herbs. Also, the review describes the potential application of microwave energy for extraction of essential oil/bioactive components from spices and herbs and the advantages of microwave-assisted process over the other extraction processes generally employed for extraction. It also showcases some recent research results on microwave drying/extraction from spices and herbs. PMID:25751729

  17. Laser Scanning in Forests

    Directory of Open Access Journals (Sweden)

    Håkan Olsson

    2012-09-01

    Full Text Available The introduction of Airborne Laser Scanning (ALS to forests has been revolutionary during the last decade. This development was facilitated by combining earlier ranging lidar discoveries [1–5], with experience obtained from full-waveform ranging radar [6,7] to new airborne laser scanning systems which had components such as a GNSS receiver (Global Navigation Satellite System, IMU (Inertial Measurement Unit and a scanning mechanism. Since the first commercial ALS in 1994, new ALS-based forest inventory approaches have been reported feasible for operational activities [8–12]. ALS is currently operationally applied for stand level forest inventories, for example, in Nordic countries. In Finland alone, the adoption of ALS for forest data collection has led to an annual savings of around 20 M€/year, and the work is mainly done by companies instead of governmental organizations. In spite of the long implementation times and there being a limited tradition of making changes in the forest sector, laser scanning was commercially and operationally applied after about only one decade of research. When analyzing high-ranked journal papers from ISI Web of Science, the topic of laser scanning of forests has been the driving force for the whole laser scanning research society over the last decade. Thus, the topic “laser scanning in forests” has provided a significant industrial, societal and scientific impact. [...

  18. Scanning with Iodine-125

    International Nuclear Information System (INIS)

    The use of I125 as I125-iodide for scanning of the thyroid and of thyroid carcinoma métastasés and as I125-labelled Rose Bengal for scanning of the liver has been investigated in our laboratories. In some patients, the thyroid scans and the scans of thyroid carcinoma metastases were repeated with I131. The liver scans were repeated with colloidal Au198. Cold nodules in the thyroid which could not be detected with I131 were clearly seen with I125. Anterior métastasés in the lungs could be differentiated from posterior métastasés with I125, while with I131 this was not possible. Using the same doses of radioactivity the background with I131 was much higher and could not be eliminated, as this would have reduced the counting rate over the lesions to levels which could not be detected. Some of the photoscans and mechanical scans of livers carried out with colloidal Au198 could not be interpreted. However, ''cold'' lesions were clearly seen on the scans of the same livers with I125-labelled Rose Bengal. (author)

  19. Optimal scan strategies for future CMB satellite experiments

    CERN Document Server

    Wallis, Christopher G R; Battye, Richard A; Delabrouille, Jacques

    2016-01-01

    The B-mode polarisation power spectrum in the Cosmic Microwave Background (CMB) is about four orders of magnitude fainter than the CMB temperature power spectrum. Any instrumental imperfections that couple temperature fluctuations to B-mode polarisation must therefore be carefully controlled and/or removed. We investigate the role that a scan strategy can have in mitigating certain common systematics by averaging systematic errors down with many crossing angles. We present approximate analytic forms for the error on the recovered B-mode power spectrum that would result from differential gain, differential pointing and differential ellipticity for the case where two detector pairs are used in a polarisation experiment. We use these analytic predictions to search the parameter space of common satellite scan strategies in order to identify those features of a scan strategy that have most impact in mitigating systematic effects. As an example we go on to identify a scan strategy suitable for the CMB satellite pro...

  20. Transcatheter Microwave Antenna

    Science.gov (United States)

    Arndt, Dickey G. (Inventor); Carl, James R. (Inventor); Ngo, Phong (Inventor); Raffoul, George W. (Inventor)

    2001-01-01

    A method, simulation, and apparatus are provided that are highly suitable for treatment of benign prostatic hyperplasia (BPH). A catheter is disclosed that includes a small diameter disk loaded monopole antenna surrounded by fusion material having a high heat of fusion and a melting point preferably at or near body temperature. Microwaves from the antenna heat prostatic tissue to promote necrosing of the prostatic tissue that relieves the pressure of the prostatic tissue against the urethra as the body reabsorbs the necrosed or dead tissue. The fusion material keeps the urethra cool by means of the heat of fusion of the fusion material. This prevents damage to the urethra while the prostatic tissue is necrosed. A computer simulation is provided that can be used to predict the resulting temperature profile produced in the prostatic tissue. By changing the various control features of the catheter and method of applying microwave energy a temperature profile can be predicted and produced that is similar to the temperature profile desired for the particular patient.

  1. Diffuse Microwave Emission Survey

    Science.gov (United States)

    Shafer, R. A.; Mather, J.; Kogut, A.; Fixsen, D. J.; Seiffert, M.; Lubin, P. M.; Levin, S. M.

    1996-12-01

    The Diffuse Microwave Emission Survey (DIMES) is a mission concept selected by NASA in 1995 to answer fundamental questions about the content and history of the universe. DIMES will use a set of absolutely calibrated cryogenic radiometers from a space platform to measure the frequency spectrum of the cosmic microwave background (CMB) at wavelengths 15--0.3 cm (frequency 2--100 GHz) to precision 0.1 mK or better. Measurements at centimeter wavelengths probe different physical processes than the COBE-FIRAS spectra at shorter wavelengths, and complement the anisotropy measurements from DMR, balloon and ground-based instruments, and the planned MAP and COBRAS/SAMBA satellites. DIMES will observe the free-free signal from early photoionization to establish the precise epoch of structure formation, and will measure or limit energy release at redshift 10(4) theory and allowed by current measurement limits; even an upper limit at the expected sensitivity 10(-5) MJy/sr will place important constraints on the matter content, structure, and evolution of the universe. Detecting these distortions or showing that they do not exist constitutes the last frontier of CMB observations.

  2. Microwave systems design

    CERN Document Server

    Awang, Zaiki

    2014-01-01

    The aim of this book is to serve as a design reference for students and as an up-to-date reference for researchers. It also acts as an excellent introduction for newcomers to the field and offers established rf/microwave engineers a comprehensive refresher.  The content is roughly classified into two – the first two chapters provide the necessary fundamentals, while the last three chapters focus on design and applications. Chapter 2 covers detailed treatment of transmission lines. The Smith chart is utilized in this chapter as an important tool in the synthesis of matching networks for microwave amplifiers. Chapter 3 contains an exhaustive review of microstrip circuits, culled from various references. Chapter 4 offers practical design information on solid state amplifiers, while Chapter 5 contains topics on the design of modern planar filters, some of which were seldom published previously. A set of problems at the end of each chapter provides the readers with exercises which were compiled from actual uni...

  3. CMORPH 8 Km: A Method that Produces Global Precipitation Estimates from Passive Microwave and Infrared Data at High Spatial and Temporal Resolution

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A new technique is presented in which half-hourly global precipitation estimates derived from passive microwave satellite scans are propagated by motion vectors...

  4. Breast PET scan

    Science.gov (United States)

    Breast positron emission tomography; PET - breast; PET - tumor imaging - breast ... A PET scan requires a small amount of radioactive material (tracer). This tracer is given through a vein (IV), usually ...

  5. Pediatric CT Scans

    Science.gov (United States)

    The Radiation Epidemiology Branch and collaborators have initiated a retrospective cohort study to evaluate the relationship between radiation exposure from CT scans conducted during childhood and adolescence and the subsequent development of cancer.

  6. Shoulder MRI scan

    Science.gov (United States)

    ... finding on an x-ray or bone scan Shoulder pain and fever Decreased motion of the shoulder joint ... of the shoulder joint Shoulder instability Shoulder weakness Shoulder pain and a history of cancer Shoulder pain that ...

  7. Scanning ultrafast electron microscopy

    OpenAIRE

    Yang, Ding-Shyue; Mohammed, Omar F.; Zewail, Ahmed H.

    2010-01-01

    Progress has been made in the development of four-dimensional ultrafast electron microscopy, which enables space-time imaging of structural dynamics in the condensed phase. In ultrafast electron microscopy, the electrons are accelerated, typically to 200 keV, and the microscope operates in the transmission mode. Here, we report the development of scanning ultrafast electron microscopy using a field-emission-source configuration. Scanning of pulses is made in the single-electron mode, for whic...

  8. Microwave Technology for Waste Management Applications Including Disposition of Electronic Circuitry

    Energy Technology Data Exchange (ETDEWEB)

    Wicks, G.G. [Westinghouse Savannah River Company, AIKEN, SC (United States); Clark, D.E. [University of Florida, Gainesville, FL (United States); Schulz, R.L. [University of Flordia, Gainesville, FL (United States)

    1998-06-01

    Advanced microwave technology is being developed nationally and internationally for a variety of waste management and environmental remediation purposes. These efforts include treatment and destruction of a vast array of gaseous, liquid and solid hazardous wastes as well as subsequent immobilization of hazardous components into leach resistant forms. Microwave technology provides an important contribution to an arsenal of existing remediation methods that are designed to protect the public and environment from the undesirable consequences of hazardous materials. One application of special interest is the treatment of discarded electronic circuitry using a new hybrid microwave treatment process and subsequent reclamation of the precious metals within.

  9. Tunable microwave notch filter created by stimulated Brillouin scattering in a silicon chip

    Science.gov (United States)

    Casas-Bedoya, A.; Morrison, Blair; Pagani, Mattia; Marpaung, David; Eggleton, Benjamin J.

    2015-12-01

    We show the first functional signal processing device based on forward stimulated Brillouin scattering from a silicon nanowire. We harness 1dB of SBS gain to create a high performance, energy efficient microwave photonic notch filter. The filter possess 48dB of suppression, 98 MHz linewidth, and is tunable within a 6 GHz bandwidth. This demonstration represents a significant advance in integrated microwave photonics with potential applications in on-chip microwave signal processing and establish the foundation towards the first CMOS-compatible high performance RF photonic filter.

  10. Microwave Technology for Waste Management Applications Including Disposition of Electronic Circuitry

    International Nuclear Information System (INIS)

    Advanced microwave technology is being developed nationally and internationally for a variety of waste management and environmental remediation purposes. These efforts include treatment and destruction of a vast array of gaseous, liquid and solid hazardous wastes as well as subsequent immobilization of hazardous components into leach resistant forms. Microwave technology provides an important contribution to an arsenal of existing remediation methods that are designed to protect the public and environment from the undesirable consequences of hazardous materials. One application of special interest is the treatment of discarded electronic circuitry using a new hybrid microwave treatment process and subsequent reclamation of the precious metals within

  11. 21 CFR 1030.10 - Microwave ovens.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Microwave ovens. 1030.10 Section 1030.10 Food and... HEALTH PERFORMANCE STANDARDS FOR MICROWAVE AND RADIO FREQUENCY EMITTING PRODUCTS § 1030.10 Microwave ovens. (a) Applicability. The provisions of this standard are applicable to microwave ovens...

  12. Computed Tomography Scanning Facility

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION:Advances research in the areas of marine geosciences, geotechnical, civil, and chemical engineering, physics, and ocean acoustics by using high-resolution,...

  13. Preface to the special issue on "Integrated Microwave Photonic Signal Processing"

    Science.gov (United States)

    Azaña, José; Yao, Jianping

    2016-08-01

    As Guest Editors, we are pleased to introduce this special issue on "Integrated Microwave Photonic Signal Processing" published by the Elsevier journal Optics Communications. Microwave photonics is a field of growing importance from both scientific and practical application perspectives. The field of microwave photonics is devoted to the study, development and application of optics-based techniques and technologies aimed to the generation, processing, control, characterization and/or distribution of microwave signals, including signals well into the millimeter-wave frequency range. The use of photonic technologies for these microwave applications translates into a number of key advantages, such as the possibility of dealing with high-frequency, wide bandwidth signals with minimal losses and reduced electromagnetic interferences, and the potential for enhanced reconfigurability. The central purpose of this special issue is to provide an overview of the state of the art of generation, processing and characterization technologies for high-frequency microwave signals. It is now widely accepted that the practical success of microwave photonics at a large scale will essentially depend on the realization of high-performance microwave-photonic signal-processing engines in compact and integrated formats, preferably on a chip. Thus, the focus of the issue is on techniques implemented using integrated photonic technologies, with the goal of providing an update of the most recent advances toward realization of this vision.

  14. Estimation of daily rainfall over Italy by merging multiple microwave-based satellite products

    Science.gov (United States)

    Panegrossi, Giulia; Casella, Daniele; Cinzia Marra, Anna; Sano, Paolo; Dietrich, Stefano; Brocca, Luca; Ciabatta, Luca; Massari, Christian

    2016-04-01

    Precipitation retrieval from space has seen great advances thanks to the improving quality of PMW measurements, the refinement of precipitation retrieval techniques, and the increasing number of microwave radiometers on board LEO satellites orbiting around the Earth. With the recent advent of the Global Precipitation Measurement (GPM) mission the constellation of cross-track and conically scanning microwave radiometers with precipitation-sensing capabilities currently ensures 1- to 3-hourly coverage at mid/high latitudes. Traditionally passive microwave (PMW) retrieval algorithms are based on the principle that surface precipitation can be estimated from the multichannel brightness temperature (TB) measurements because these are affected (in different ways depending on channel frequency, viewing geometry, spatial resolution, and surface background conditions) by the microphysical properties and 3-D distribution of liquid and frozen hydrometeors within the precipitating cloud, and, therefore, can be related to surface precipitation. These approaches can be categorized as top-down approaches and they provide instantaneous precipitation rate estimate at the surface at the time of the satellite observation. Recently a new perspective for surface precipitation estimate has been proposed, the bottom-up approach, based on the principle that the soil moisture can be considered as a "natural raingauge" and can be employed for "measuring" rainfall. The algorithm, called SM2RAIN, allows estimating rainfall directly from soil moisture retrieved from spaceborne sensors (i.e., ASCAT). Several recent studies have demonstrated that the approach is very effective for precipitation estimation from the daily to 5-daily scale, even though not applicable in regions where soil moisture retrieval is not feasible (i.e., highly vegetated areas, frozen surfaces, oceans). This study shows that the precipitation estimates obtained by PMW observations using the two approaches (top-down and

  15. Hyperspectral Microwave Atmospheric Sounder (HyMAS) architecture and design accommodations

    Science.gov (United States)

    Hilliard, L.; Racette, P.; Blackwell, W.; Galbraith, C.; Thompson, E.

    The Hyperspectral Microwave Atmospheric Sounder (HyMAS) is being developed at Lincoln Laboratories and accommodated by the Goddard Space Flight Center for a flight opportunity on a NASA research aircraft. The term “ hyperspectral microwave” is used to indicate an all-weather sounding that performs equivalent to hyperspectral infrared sounders in clear air with vertical resolution of approximately 1 km. Deploying the HyMAS equipped scanhead with the existing Conical Scanning Microwave Imaging Radiometer (CoSMIR) shortens the path to a flight demonstration. Hyperspectral microwave is achieved through the use of independent RF antennas that sample the volume of the Earth's atmosphere through various levels of frequencies, thereby producing a set of dense, spaced vertical weighting functions. The simulations proposed for HyMAS 118/183-GHz system should yield surface precipitation rate and water path retrievals for small hail, soft hail, or snow pellets, snow, rainwater, etc. with accuracies comparable to those of the Advanced Technology Microwave Sounder. Further improvements in retrieval methodology (for example, polarization exploitation) are expected. The CoSMIR instrument is a packaging concept re-used on HyMAS to ease the integration features of the scanhead. The HyMAS scanhead will include an ultra-compact Intermediate Frequency Processor (IFP) module that is mounted inside the door to improve thermal management. The IFP is fabricated with materials made of Low-Temperature Co-fired Ceramic (LTCC) technology integrated with detectors, amplifiers, A/D conversion and data aggregation. The IFP will put out 52 channels of 16 bit data comprised of 4 - 9 channel data streams for temperature profiles and 2-8 channel streams for water vapor. With the limited volume of the existing CoSMIR scanhead and new HyMAS front end components, the HyMAS team at Goddard began preliminary layout work inside the new drum. Importing and re-using models of the shell, the s- an head

  16. X-ray laminography with panel detector translation scan

    International Nuclear Information System (INIS)

    An advanced fast quasi-3D imaging method for inspecting moving object is presented. Using cone-beam X-ray and panel detector translation scan (PDTS), quasi-3D data of the object structure can be obtained just by one translation scan. (authors)

  17. QUANTITATIVE CONFOCAL LASER SCANNING MICROSCOPY

    Directory of Open Access Journals (Sweden)

    Merete Krog Raarup

    2011-05-01

    Full Text Available This paper discusses recent advances in confocal laser scanning microscopy (CLSM for imaging of 3D structure as well as quantitative characterization of biomolecular interactions and diffusion behaviour by means of one- and two-photon excitation. The use of CLSM for improved stereological length estimation in thick (up to 0.5 mm tissue is proposed. The techniques of FRET (Fluorescence Resonance Energy Transfer, FLIM (Fluorescence Lifetime Imaging Microscopy, FCS (Fluorescence Correlation Spectroscopy and FRAP (Fluorescence Recovery After Photobleaching are introduced and their applicability for quantitative imaging of biomolecular (co-localization and trafficking in live cells described. The advantage of two-photon versus one-photon excitation in relation to these techniques is discussed.

  18. Microwave mixer technology and applications

    CERN Document Server

    Henderson, Bert

    2013-01-01

    Although microwave mixers play a critical role in wireless communication and other microwave applications employing frequency conversion circuits, engineers find that most books on this subject emphasize theoretical aspects, rather than practical applications. That's about to change with the forthcoming release of Microwave Mixer Technology and Applications. Based on a review of over one thousand patents on mixers and frequency conversion, authors Bert Henderson and Edmar Camargo have written a comprehensive book for mixer designers who want solid ideas for solving their own design challenges.

  19. Microwave Technologies-- Determination of Magnetic and Dielectric Materials Microwave Properties

    CERN Document Server

    Obol, Mahmut

    2009-01-01

    In this study, four different techniques are presented. 1 Rectangular waveguide measurement technique for normal microwave materials microwave properties such as permeability and permittivity. This technique removed guess parameter and dispersive effect issues of the old waveguide measurement techniques. It projects a new route for determination of any microwave materials magnetic and dielectric properties without using any guesses. 2 Coaxial probe measurement technique for the liquid and biological tissues dielectric permittivity. This coaxial probe technique has an advantage which is to attain the highest reflected signal from the coaxial probe tip, so that it is a fast and very sensitive technique to differentiate lossy materials dielectric permittivity. This technique could be useful non destructive detections for tumors in hospital and non destructive detections for chemical liquids as well. 3 A microstripline measurement technique for oxides microwave measurement at low frequency spectra where the waveg...

  20. Dexter: Data Extractor for scanned graphs

    Science.gov (United States)

    Demleitner, Markus

    2011-12-01

    The NASA Astrophysics Data System (ADS) now holds 1.3 million scanned pages, containing numerous plots and figures for which the original data sets are lost or inaccessible. The availability of scans of the figures can significantly ease the regeneration of the data sets. For this purpose, the ADS has developed Dexter, a Java applet that supports the user in this process. Dexter's basic functionality is to let the user manually digitize a plot by marking points and defining the coordinate transformation from the logical to the physical coordinate system. Advanced features include automatic identification of axes, tracing lines and finding points matching a template.

  1. Microwave antenna holography

    Science.gov (United States)

    Rochblatt, David J.; Seidel, Boris L.

    1992-01-01

    This microwave holography technique utilizes the Fourier transform relation between the complex far field radiation pattern of an antenna and the complex aperture field distribution. Resulting aperture phase and amplitude distribution data can be used to precisely characterize various crucial performance parameters, including panel alignment, panel shaping, subreflector position, antenna aperture illumination, directivity at various frequencies, and gravity deformation effects. The methodology of data processing presented here was successfully applied to the Deep Space Network (DSN) 34-m beam waveguide antennas. The antenna performance was improved at all operating frequencies by reducing the main reflector mechanical surface rms error to 0.43 mm. At Ka-band (32 GHz), the estimated improvement is 4.1 dB, resulting in an aperture efficiency of 52 percent. The performance improvement was verified by efficiency measurements and additional holographic measurements.

  2. Bone scanning in osteoporosis

    International Nuclear Information System (INIS)

    This paper reports on bone scanning in osteoporosis a diagnosis of osteoporosis most often follows fracture, and clearly this should be confirmed by x-ray. The bone scan therefore does not have an important role to play in the initial diagnosis of osteoporosis. While the exact mechanism by which the 99mTc-labeled diphosphonates localize in the skeleton is not fully understood, it is believed that they adsorb onto bone surfaces most probably via the calcium of hydroxyapatite crystals. Because the major factors that affect adsorption are osteoblastic activity and to a lesser extent skeletal vascularity, it is apparent that a bone scan image presents a functional display of skeletal metabolic activity. However, osteoporosis is a disorder in which gradual change in bone mass may occur over many years and, in keeping with this minor imbalance in skeletal metabolism, the bone scan appearances are usually normal. However, the scan images may appear of poor quality because of relatively low bone uptake of tracer with, on occasion, a washed-out pattern of activity in the axial and appendicular bone. It has been suggested that such a pattern occurs in severe or end-stage osteoporosis caused by markedly reduced osteoblastic activity. If kyphosis is observed on the bone scan or if there appears to be loss of spinal height with proximity of ribs to each other or increased closeness of rib cage to pelvis, then appearances suggest vertebral collapse and would be in keeping with a diagnosis of osteoporosis. Such evidence is, however, indirect and in practice a bone scan is an extremely unreliable means of diagnosing osteoporosis

  3. Bone scan in pediatrics

    International Nuclear Information System (INIS)

    In 1984, a survey carried out in 21 countries in Europe showed that bone scintigraphy comprised 16% of all paediatric radioisotope scans. Although the value of bone scans in paediatrics is potentially great, their quality varies greatly, and poor-quality images are giving this valuable technique a bad reputation. The handling of children requires a sensitive staff and the provision of a few simple inexpensive items of distraction. Attempting simply to scan a child between two adult patients in a busy general department is a recipe for an unhappy, uncooperative child with the probable result of poor images. The intravenous injection of isotope should be given adjacent to the gamma camera room, unless dynamic scans are required, so that the child does not associate the camera with the injection. This injection is best carried out by someone competent in paediatric venipunture; the entire procedure should be explained to the child and parent, who should remain with child throughout. It is naive to think that silence makes for a cooperative child. The sensitivity of bone-seeking radioisotope tracers and the marked improvement in gamma camera resolution has allowed the bone scanning to become an integrated technique in the assessment of children suspected of suffering from pathological bone conditions. The tracer most commonly used for routine bone scanning is 99mTc diphosphonate (MDP); other isotopes used include 99mTc colloid for bone marrow scans and 67Ga citrate and 111In white blood cells (111In WBC) for investigation of inflammatory/infective lesions

  4. Lung Ventilation/Perfusion Scan

    Science.gov (United States)

    ... two types of scans: ventilation and perfusion. The ventilation scan shows where air flows in your lungs. The perfusion scan shows where blood flows in your lungs. Both scans use radioisotopes (a low-risk radioactive substance). For the ventilation scan, you ...

  5. Scanning Probe Microscopy and Spectroscopy

    Science.gov (United States)

    Wiesendanger, Roland

    1994-09-01

    Preface; List of acronyms; Introduction; Part I. Experimental Methods and Theoretical Background of Scanning Probe Microscopy and Spectroscopy: 1. Scanning tunnelling microscopy; 2. Scanning force microscopy; 3. Related scanning probe techniques; Part II. Applications of Scanning Probe Microscopy and Spectroscopy: 4. Condensed matter physics; 5. Chemistry; 6. Organic materials; 7. Metrology and standards; 8. Nanotechnology; References; Index.

  6. Comparison between microwave and microwave plasma sintering of nickel powders

    OpenAIRE

    Breen, Aidan; Twomey, Barry; Byrne, Greg; Dowling, Denis P.

    2011-01-01

    There is considerable interest in processing technologies which can lead to more energy efficient sintering of metal powders. The use of microwave sintering in particular leads to reduced energy usage during sintering as the volumetric heating process is considerably more efficient compared with resistance heating. In this study the use of a novel plasma microwave processing technology for the sintering of nickel powder discs is evaluated. The sintering study was carried out on...

  7. Microwaves and particle accelerators: a fundamental link

    International Nuclear Information System (INIS)

    John Cockcroft's splitting of the atom and Ernest Lawrence's invention of the cyclotron in the first half of the twentieth century ushered in the grand era of ever higher energy particle accelerators to probe deeper into matter. It also forged a link, bonding scientific discovery with technological innovation that continues today in the twenty first century. The development of radar and high power vacuum electronics, especially microwave power tubes like the magnetrons and the klystrons in the pre-second world war era, was instrumental in the rapid development of circular and linear charged particle accelerators in the second half of the twentieth century. We had harnessed the powerful microwave radio-frequency sources from few tens of MHz to up to 90 GHz spanning L-band to W-band frequencies. Simultaneously in the second half of the twentieth century, lasers began to offer very first opportunities of controlling charged particles at smaller resolutions on the scale of wavelengths of visible light. We also witnessed in this period the emergence of the photon and neutron sciences driven by accelerators built-by-design producing tailored and ultra-bright pulses of bright photons and neutrons to probe structure and function of matter from aggregate to individual molecular and atomic scales in unexplored territories in material and life sciences. As we enter the twenty first century, the race for ever higher energies, brightness and luminosity to probe atto-metric and atto-second domains of the ultra-small structures and ultra-fast processes continues. These developments depend crucially on yet further advancements in the production and control of high power and high frequency microwaves and light sources, often intricately coupled in their operation to the high energy beams themselves. We give a glimpse of the recent developments and innovations in the electromagnetic production and control of charged particle beams in the service of science and society. (author)

  8. Synthesis of nitrogen-doped graphene via solid microwave method

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Li, E-mail: zhangli379@sohu.com [School of Electrical Engineering, Dalian University of Technology, Dalian, Liaoning 116024 (China); Ji, Bingcheng, E-mail: debbo.jee@outlook.com [School of Electrical Engineering, Dalian University of Technology, Dalian, Liaoning 116024 (China); Wang, Kai [School of Electrical Engineering, Dalian University of Technology, Dalian, Liaoning 116024 (China); Song, Jinyan [School of Information Engineering, Dalian Ocean University, Dalian, Liaoning 116024 (China)

    2014-07-01

    Graphical abstract: - Highlights: • A direct solid microwave method is developed to prepare nitrogen-doped graphene. • The method consists of two steps, namely the functionalization and microwave irradiation. • Melamine can serve as not only functionalizing agent but also nitrogen source. - Abstract: In this paper, we propose a solid microwave-mediated method for scalable production of nitrogen-doped graphene sheets (NGS) using low-cost industrial material melamine as functionalizing agent and nitrogen source. The strong interaction of microwaves with graphene oxide has been fully utilized to generate in situ heating that induces the decompose melamine and nitrogen doping of graphene. The morphology, structure, and components of the as-produced nitrogen-doped graphene are characterized by scanning electron microscopy (SEM), transmission electron microscope (TEM), Brunauer–Emmett–Teller (BET), pore-size distribution (PSD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectra (XPS), X-ray diffraction (XRD), and Raman spectroscopy. The results show NGS can be successfully synthesized via this strategy.

  9. Complex-mediated microwave-assisted synthesis of polyacrylonitrile nanoparticles

    Directory of Open Access Journals (Sweden)

    Trinath Biswal

    2010-10-01

    Full Text Available Trinath Biswal, Ramakanta Samal, Prafulla K SahooDepartment of Chemistry, Utkal University, Vani Vihar, Bhubaneswar 751004, IndiaAbstract: The polymerization of acrylonitrile (AN is efficiently, easily, and quickly achieved in the presence of trans-[Co(IIIen2Cl2]Cl complex in a domestic microwave (MW oven. MW irradiation notably promoted the polymerization reaction; this phenomenon is ascribed to the acceleration of the initiator, ammonium persulfate (APS, decomposition by microwave irradiation in the presence of [Co(IIIen2Cl2]Cl. The conversion of monomer to the polymer was mostly excellent in gram scale. Irradiation at low power and time produced more homogeneous polymers with high molecular weight and low polydispersity when compared with the polymer formed by a conventional heating method. The interaction of reacting components was monitored by UV-visible spectrometer. The average molecular weight was derived by gel permeation chromatography (GPC, viscosity methods, and sound velocity by ultrasonic interferometer. The uniform and reduced molecular size was characterized by transmission electron microscopy, the diameter of polyacrylonitrile nanoparticles (PAN being in the range 50–115 nm and 40–230 nm in microwave and conventional heating methods respectively. The surface morphology of PAN prepared by MW irradiation was characterized by scanning electron microscope (SEM. From the kinetic results, the rate of polymerization (Rp was expressed as Rp = [AN]0.63 [APS]0.57 [complex (I].0.88Keywords: microwave, complex catalyst, nanoparticle, kinetics

  10. Microwave absorption of electroless Ni-Co-P-coated SiO2 powder

    International Nuclear Information System (INIS)

    Ni-Co-P-coated SiO2 particles were prepared using electroless plating method. The morphology, crystal structure, surface compositions, magnetic and microwave absorption properties of the composite powder were investigated by scanning electron microscopy, X-ray diffraction analysis, X-ray photoelectron spectroscopy, vibrating sample magnetometer and vector network analyzer, respectively. It was found that the silica powder was successfully coated with Ni-Co-P alloy. The ultrafine Ni-Co-P-SiO2 powder-paraffin wax composite possesses excellent microwave absorption properties. The maximum microwave loss reaches -48.6 dB at 4.2 GHz with a thickness of 3.10 mm. The intrinsic reasons for microwave absorption were also investigated.

  11. Microwave sintering of ZnO nanopowders and characterization for gas sensing

    International Nuclear Information System (INIS)

    Thick film gas sensors based on ZnO nanopowders were fabricated by using microwave sintering. The surface and cross section morphologies were characterized by field-emission scanning electron microscopy (FE-SEM). The stability of the microstructure was studied by impedance spectroscopy. The results showed that the shape of the nanoparticles was not changed through microwave sintering, and the thick films had the more dense microstructures than that by muffle oven sintering. The resistance-temperature characteristic and the responses to toluene, methanol and formaldehyde revealed that the microwave sintering technique could effectively control the growth of ZnO nanoparticles, realize the uniform sintering of thick film, gain the stable microstructure and improve the response of sensor. In addition, the formative mechanism of the thick film microstructure was proposed according to microwave sintering mechanism.

  12. Breast cancer imaging by microwave-induced thermoacoustic tomography

    Science.gov (United States)

    Xu, Minghua; Ku, Geng; Jin, Xing; Wang, Lihong V.; Fornage, Bruno D.; Hunt, Kelly K.

    2005-04-01

    We report a preliminary study of breast cancer imaging by microwave-induced thermoacoustic tomography. In this study, we built a prototype of breast cancer imager based on a circular scan mode. A 3-GHz 0.3~0.5-μs microwave is used as the excitation energy source. A 2.25-MHz ultrasound transducer scans the thermoacoustic signals. All the measured data is transferred to a personal computer for imaging based on our proposed back-projection reconstruction algorithms. We quantified the line spread function of the imaging system. It shows the spatial resolution of our experimental system reaches 0.5 mm. After phantom experiments demonstrated the principle of this technique, we moved the imaging system to the University of Texas MD Anderson Cancer Center to image the excised breast cancer specimens. After the surgery performed by the physicians at the Cancer Center, the excised breast specimen was placed in a plastic cylindrical container with a diameter of 10 cm; and it was then imaged by three imaging modalities: radiograph, ultrasound and thermoacoustic imaging. Four excised breast specimens have been tested. The tumor regions have been clearly located. This preliminary study demonstrated the potential of microwave-induced thermoacoustic tomography for applications in breast cancer imaging.

  13. Wide spectrum microwave pulse measurement

    Energy Technology Data Exchange (ETDEWEB)

    King, R.J.

    1986-01-01

    Various techniques are postulated as diagnostics for wide band microwave pulses. The diagnostics include determinations of both the instantaneous amplitude and the frequency content of one-shot pulses. 6 refs., 11 figs. (WRF)

  14. Passive Microwave Components and Antennas

    DEFF Research Database (Denmark)

    may severely deteriorate performance of the overall system. Different techniques for wideband matching are presented in the third part of this book. The design of compact microwave resonators and filters is also covered in this part. Compact, high-performance microwave filters are essential for high......-efficiency miniaturized microwave systems. The filter circuit size is large in traditionally designed planar bandpass filters due to a high number of large area resonators. The rejection level in the upper stopband of the filters is usually degraded by the spurious response at twice the passband frequency. Several types...... various resonator combinations within one filter structure to reduce the circuit size, such as the loop resonator or hairpin resonator incorporated with one or several open stubs. Recently, microwave filters based on electromagnetic bandgap structures and artificial materials have attracted a great deal...

  15. Wide spectrum microwave pulse measurement

    International Nuclear Information System (INIS)

    Various techniques are postulated as diagnostics for wide band microwave pulses. The diagnostics include determinations of both the instantaneous amplitude and the frequency content of one-shot pulses. 6 refs., 11 figs

  16. Microwave photonics: Harnessing slow light

    OpenAIRE

    Capmany J.; Gasulla I.; Sales S.

    2011-01-01

    Slow-light techniques originally conceived for buffering high-speed digital optical signals now look set to play an important role in providing broadband phase and true time delays for microwave signals.

  17. Microwave Dielectrophoretic Levitation In Microgravity

    Science.gov (United States)

    Watkins, John L.; Jackson, Henry W.; Barmatz, Martin B.

    1993-01-01

    Two reports propose use of dielectrophoresis in microwave resonant cavities to levitate samples of materials for containerless processing in microgravity in vacuum or in any suitable atmosphere. Also describe experiments undertaken to verify feasibility of proposal.

  18. Tracking Code for Microwave Instability

    Energy Technology Data Exchange (ETDEWEB)

    Heifets, S.; /SLAC

    2006-09-21

    To study microwave instability the tracking code is developed. For bench marking, results are compared with Oide-Yokoya results [1] for broad-band Q = 1 impedance. Results hint to two possible mechanisms determining the threshold of instability.

  19. Wide-Angle-Scanning Reflectarray Antennas Actuated by MEMS

    Science.gov (United States)

    Fang, Houfei; Huang, John; Thomson, Mark W.

    2009-01-01

    An effort to develop large-aperture, wide-angle-scanning reflectarray antennas for microwave radar and communication systems is underway. In an antenna of this type as envisioned, scanning of the radiated or incident microwave beam would be effected through mechanical rotation of the passive (reflective) patch antenna elements, using microelectromechanical systems (MEMS) stepping rotary actuators typified by piezoelectric micromotors. It is anticipated that the cost, mass, and complexity of such an antenna would be less than, and the reliability greater than, those of an electronically scanned phased-array antenna of comparable beam-scanning capability and angular resolution. In the design and operation of a reflectarray, one seeks to position and orient an array of passive patch elements in a geometric pattern such that, through constructive interference of the reflections from them, they collectively act as an efficient single reflector of radio waves within a desired frequency band. Typically, the patches lie in a common plane and radiation is incident upon them from a feed horn.

  20. Volcanic eruption source parameters from active and passive microwave sensors

    Science.gov (United States)

    Montopoli, Mario; Marzano, Frank S.; Cimini, Domenico; Mereu, Luigi

    2016-04-01

    It is well known, in the volcanology community, that precise information of the source parameters characterising an eruption are of predominant interest for the initialization of the Volcanic Transport and Dispersion Models (VTDM). Source parameters of main interest would be the top altitude of the volcanic plume, the flux of the mass ejected at the emission source, which is strictly related to the cloud top altitude, the distribution of volcanic mass concentration along the vertical column as well as the duration of the eruption and the erupted volume. Usually, the combination of a-posteriori field and numerical studies allow constraining the eruption source parameters for a given volcanic event thus making possible the forecast of ash dispersion and deposition from future volcanic eruptions. So far, remote sensors working at visible and infrared channels (cameras and radiometers) have been mainly used to detect, track and provide estimates of the concentration content and the prevailing size of the particles propagating within the ash clouds up to several thousand of kilometres far from the source as well as track back, a-posteriori, the accuracy of the VATDM outputs thus testing the initial choice made for the source parameters. Acoustic wave (infrasound) and microwave fixed scan radar (voldorad) were also used to infer source parameters. In this work we want to put our attention on the role of sensors operating at microwave wavelengths as complementary tools for the real time estimations of source parameters. Microwaves can benefit of the operability during night and day and a relatively negligible sensitivity to the presence of clouds (non precipitating weather clouds) at the cost of a limited coverage and larger spatial resolution when compared with infrared sensors. Thanks to the aforementioned advantages, the products from microwaves sensors are expected to be sensible mostly to the whole path traversed along the tephra cloud making microwaves particularly

  1. Effects of microwave power and polyvinyl pyrrolidone on microwave polyol process of carbon-supported Cu catalysts for CO oxidation

    International Nuclear Information System (INIS)

    Highlights: → The microwave polyol process is a simple preparation for AC-supported catalyst. → PVP may as an unconsidered protecting agent for catalyst preparation. → The AC-supported Cu0 catalyst showed high activity for CO oxidation at 175 deg. C. - Abstract: The purpose of this study was to prepare an activated carbon (AC)-supported copper catalyst by a simple method - the microwave polyol process - and to evaluate the effects of microwave power and protecting agent on the resulting catalyst activity. The catalysts were characterized by Brunauer-Emmett-Teller (BET) surface area, X-ray diffraction (XRD), and field-emission scanning electron microscopy (FESEM). Experimental results indicated that a microwave power of 700 W was highly effective, and that copper particles (60 (±18) nm) dispersed well on the AC support, even in the absence of the protecting agent poly-vinyl pyrrolidone (PVP). The AC-supported Cu0 catalyst generated high catalytic activity for CO oxidation (90% CO conversion at 175 oC).

  2. Free-space components for microwave transmission

    Science.gov (United States)

    Will, Scott; Kudyshev, Zhaxylyk A.; Litchinitser, Natalia M.

    2015-01-01

    The ability to guide, manipulate, and process radio- and microwave-frequency radiation is limited by two major factors. From a fundamental viewpoint, the intensity and width of a beam propagating in a free space, as well as the angular and range resolution of radar systems, are limited by diffraction. From a practical viewpoint, free-space beam processing is hindered by a lack of free-space instrumentation for beam focusing, steering, or (de)-multiplexing. As a result, modern radar systems often employ advanced signal processing and detection techniques aimed at enhancing target and feature estimation. Here, we propose several new structures founded upon the emerging plasma filament-based approach to metamaterial design that are aimed at addressing such problems and providing tools for greater capability in microwave transmission than has been possible in the past. In particular, we have designed new structures formed from arrays of plasma filaments in air that leverage the anisotropic behavior of such arrays to address the limits of angular and range resolution, as well as the lack of free-space components for processing radiation in wireless communications.

  3. Microwave applications of soft ferrites

    CERN Document Server

    Pardavi-Horvath, M P

    2000-01-01

    Signal processing requires broadband, low-loss, low-cost microwave devices (circulators, isolators, phase shifters, absorbers). Soft ferrites (garnets, spinels, hexaferrites), applied in planar microwave devices, are reviewed from the point of view of device requirements. Magnetic properties, specific to operation in high-frequency electromagnetic fields, are discussed. Recent developments in thick film ferrite technology and device design are reviewed. Magnetic losses related to planar shape and inhomogeneous internal fields are analyzed.

  4. Student concepts of microwave ovens

    Science.gov (United States)

    Kassebaum, Thomas; May, David; Aubrecht, Gordon

    2000-05-01

    Previous surveys and student interviews have revealed that students believe microwave ovens can be a source of microwave radiation, x radiation, and gamma radiation. We have probed student ideas in recent detailed interviews and find that students believe that at least some form of what physicists call electromagnetic radiation is emitted and that x and gamma radiation can make a person radioactive. We will discuss details of these interviews, comparing the results to what we learned in previous surveys.

  5. Cryogenic microwave imaging of metal–insulator transition in doped silicon

    KAUST Repository

    Kundhikanjana, Worasom

    2011-01-01

    We report the instrumentation and experimental results of a cryogenic scanning microwave impedance microscope. The microwave probe and the scanning stage are located inside the variable temperature insert of a helium cryostat. Microwave signals in the distance modulation mode are used for monitoring the tip-sample distance and adjusting the phase of the two output channels. The ability to spatially resolve the metal-insulator transition in a doped silicon sample is demonstrated. The data agree with a semiquantitative finite element simulation. Effects of the thermal energy and electric fields on local charge carriers can be seen in the images taken at different temperatures and dc biases. © 2011 American Institute of Physics.

  6. Study of federal microwave standards

    Energy Technology Data Exchange (ETDEWEB)

    David, L.

    1980-08-01

    Present and future federal regulatory processes which may impact the permissible levels of microwave radiation emitted by the SPS Microwave Power Transmission (MPTS) were studied. An historical development of US occupational and public microwave standards includes an overview of Western and East European philosophies of environmental protection and neurophysiology which have led to the current widely differing maximum permissible exposure limits to microwaves. The possible convergence of microwave standards is characterized by a lowering of Western exposure levels while Eastern countries consider standard relaxation. A trend toward stricter controls on activities perceived as harmful to public health is under way as is interest in improving the federal regulatory process. Particularly relevant to SPS is the initiation of long-term, low-level microwave exposure programs. Coupled with new developments in instrumentation and dosimetry, the results from chronic exposure program and population exposure studies could be expected within the next five to ten years. Also discussed is the increasing public concern that rf energy is yet another hazardous environmental agent.

  7. Effect of microwave power on the morphology and optical property of zinc oxide nano-structures prepared via a microwave-assisted aqueous solution method

    International Nuclear Information System (INIS)

    The effect of the microwave power on the morphology and optical properties of zinc oxide nanostructures prepared using a microwave-assisted aqueous solution method has been investigated. The ZnO nanostructures were synthesized from zinc chloride and sodium hydroxide mixed aqueous solutions exposed for 5 min to microwave radiation at four different powers, namely 150, 450, 700 and 1000 W. The morphologies of the samples have been characterized by transmission electron microscope (TEM) and scanning electron microscope (SEM). The results showed that the power of microwave radiation influenced the shape and size of the synthesized nanostructures. It is also found that the average particle size of nanostructures decreased with decreasing microwave power. The results of X-ray diffraction (XRD) showed that all the as-prepared ZnO nanostructures are in crystalline form with high purity. The infrared (IR) spectra indicated that the as-prepared nano ZnO product can be used as infrared gas sensors such as an infrared carbon dioxide (CO2) and/or CO sensor. Optical properties of the as-prepared ZnO nanostructures were investigated by UV-vis spectroscopy and showed that the optical properties of as-synthesized ZnO samples are sensitive to the variation of the power of microwave radiation.

  8. Developments in CO2 dissociation using non-equilibrium microwave plasma activation for solar fuels

    NARCIS (Netherlands)

    Bongers, W. A.; Welzel, S.; van den Bekerom, D. C. M.; Frissen, G. F. W. M.; van Rooij, G. J.; Goede, A. P. H.; Graswinckel, M. F.; Groen, P. W. C.; N. den Harder,; van Heemert, B.; Minea, T.; M. C. M. van de Sanden,; Leins, M.; Kopecki, J.; Schulz, A.; Walker, M.

    2015-01-01

    Vortex stabilized microwave plasma conversion of CO2 is considered as promising route for energy efficient dissociation towards CO production. Energy and conversion efficiencies are investigated in scans of reactor pressure, gas flow rate and specific power. Deterioration of efficiencies from 39% to

  9. Detection of lower-hybrid waves on Versator II using microwave scattering

    International Nuclear Information System (INIS)

    An experiment using 139 GHz microwave scattering to detect 0.8 GHz lower-hybrid waves is described. A simple analysis is presented to relate scattered signal to wave power. Radial scans and N/sub z/ spectra are presented as well as evidence of wave absorption during current-drive

  10. Anisotropies in the cosmic microwave background: Theory

    Energy Technology Data Exchange (ETDEWEB)

    Dodelson, S.

    1998-02-01

    Anisotropies in the Cosmic Microwave Background (CMB) contain a wealth of information about the past history of the universe and the present values of cosmological parameters. I online some of the theoretical advances of the last few years. In particular, I emphasize that for a wide class of cosmological models, theorists can accurately calculate the spectrum to better than a percent. The spectrum of anisotropies today is directly related to the pattern of inhomogeneities present at the time of recombination. This recognition leads to a powerful argument that will enable us to distinguish inflationary models from other models of structure formation. If the inflationary models turn out to be correct, the free parameters in these models will be determined to unprecedented accuracy by the upcoming satellite missions.

  11. Bone scan in rheumatology

    International Nuclear Information System (INIS)

    In this chapter a revision is made concerning different uses of bone scan in rheumatic diseases. These include reflex sympathetic dystrophy, osteomyelitis, spondyloarthropaties, metabolic bone diseases, avascular bone necrosis and bone injuries due to sports. There is as well some comments concerning pediatric pathology and orthopedics. (authors). 19 refs., 9 figs

  12. Scanning bubble chamber pictures

    CERN Multimedia

    1974-01-01

    These were taken at the 2 m hydrogen bubble chamber. The photo shows an early Shiva system where the pre-measurements needed to qualify the event were done manually (cf photo 7408136X). The scanning tables were located in bld. 12. Gilberte Saulmier sits on foreground, Inge Arents at centre.

  13. Getting a CAT Scan

    Medline Plus

    Full Text Available ... The scan itself is painless. All you'll need to do is hold still for a few minutes at a time so the pictures come out clear ... the Nemours Web site. Note: All information on KidsHealth® is for educational purposes only. For ...

  14. Scan This Book!

    Science.gov (United States)

    Albanese, Andrew Richard

    2007-01-01

    In this article, the author presents an interview with Brewster Kahle, leader of the Open Content Alliance (OCA). OCA book scan program is an alternative to Google's library project that aims to make books accessible online. In this interview, Kahle discusses his views on the challenges of getting books on the Web, on Google's library…

  15. Surface micromachined scanning mirrors

    DEFF Research Database (Denmark)

    Mattsson, Kent Erik

    Both aluminum cantilever and torsional scanning mirrors have been fabricated and their static and dynamic properties are studied experimentally and theoretically. The experiments showed resonance frequencies in the range of 163 k-Hz - 632 kHz for cantilever beams with Q values between 5 and 11. T...

  16. Lung gallium scan

    Science.gov (United States)

    ... Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team. Related MedlinePlus Health Topics Lung Diseases Nuclear Scans Sarcoidosis Browse the Encyclopedia A.D.A. ...

  17. Scanned probe characterization of semiconductor nanostructures

    OpenAIRE

    Law, James Jeremy MacDonald

    2009-01-01

    Advances in the synthesis of materials and device structures have accentuated the need to understand nanoscale electronic structure and its implications. Scanning probe microscopy offers a rich variety of highly spatially accurate techniques that can further our understanding of the interactions that occur in nanoscale semiconductor materials and devices. The promising nitride semiconductor materials system suffers from perturbations in local electronic structure due to crystallographic defec...

  18. Microwave Irradiation of Nanohydroxyapatite from Chicken Eggshells and Duck Eggshells

    Directory of Open Access Journals (Sweden)

    Nor Adzliana Sajahan

    2014-01-01

    Full Text Available Due to similarity in composition to the mineral component of bones and human hard tissues, hydroxyapatite with chemical formula Ca10(PO46(OH2 has been widely used in medical field. Both chicken and duck eggshells are mainly composed of calcium carbonate. An attempt has been made to fabricate nanohydroxyapatite (nHA by chicken (CES and duck eggshells (DES as calcium carbonate source (CaCO3. CES and DES were reacted with diammonium hydrogen [(NH42HPO4] solution and subjected to microwave heating at 15 mins. Under the effect of microwave irradiation, nHA was produced directly in the solution and involved in crystallographic transformation. Sample characterization was done using by X-ray diffraction (XRD, fourier transform infrared spectroscopy (FTIR, and scanning electron microscopy (SEM.

  19. Rutile filled PTFE composites for flexible microwave substrate applications

    International Nuclear Information System (INIS)

    Rutile filled PTFE composite substrates were fabricated for microwave circuit applications. Morphology of the composites and dispersion of filler in the polymer matrix were studied using Scanning Electron Microscopic technique. Microwave dielectric properties of filled composites were measured by waveguide cavity perturbation technique using Vector Network Analyzer. Different theoretical modeling approaches were used to predict the dielectric constant of PTFE composites with respect to filler loading. The temperature coefficient of dielectric constant (τε'r) was measured in the 0-100 deg. C temperature range. Moisture absorption properties were measured as per IPC-TM-650 2.6.2 standards. Universal testing machine was used to evaluate the tensile properties. Flexible laminates having dielectric constant 10.2 with loss tangent 0.0022 was realized in the PTFE/rutile composites at X-band frequency region.

  20. Microwave synthesis of phase-pure, fine silicon carbide powder

    International Nuclear Information System (INIS)

    Fine, monophasic silicon carbide powder has been synthesized by direct solid-state reaction of its constituents namely silicon and carbon in a 2.45 GHz microwave field. Optimum parameters for the silicon carbide phase formation have been determined by varying reaction time and reaction temperature. The powders have been characterized for their particle size, surface area, phase composition (X-ray diffraction) and morphology (scanning electron microscope). Formation of phase-pure silicon carbide can be achieved at 1300 deg. C in less than 5 min of microwave exposure, resulting in sub-micron-sized particles. The free energy values for Si + C → SiC reaction were calculated for different temperatures and by comparing them with the experimental results, it was determined that phase-pure silicon carbide can be achieved at around 1135 deg. C

  1. Microwave scattering parameter imagery of an isolated canine kidney

    International Nuclear Information System (INIS)

    This paper describes a method for imaging biosystems using radiation in the microwave frequency range (3.9 GHz). The advantages of interrogation with microwave radiation are discussed in terms of its physiological significance. An electromechanical scanning system for imaging isolated organs and the subsequent image processing techniques are described. Imagery is presented for a phantom target and an isolated canine kidney. The kidney images are interpreted in terms of the known anatomical and functional organization of the organ. It does appear to be possible to distinguish cortex corticis corresponding to a high proportion of proximal and distal convoluted tubules, deeper cortical layers corresponding to a high population density of glomeri, a medullary outer zone corresponding to the loops of Henle as well as the collecting system, and the region of calyces/renal pelvis

  2. Carbon Nanomaterial Produced by Microwave Exfoliation of Graphite Oxide

    Directory of Open Access Journals (Sweden)

    Shulga Y.M.

    2013-09-01

    Full Text Available Carbon-based graphene-like material was obtained through microwave stimulated exfoliation of graph-ite oxide (GO. Properties of this material were investigated by multiple techniques including element analysis, X-ray photoelectron spectroscopy (XPS, mass-spectroscopy, infrared (IR and Raman spectrosco-py, scanning electron microscopy (SEM and broadband dielectric spectroscopy. Specific surface area and volume of microwave exfoliated graphite oxide (MEGO reached 600 m2/g and 6 cm3/g, respectively. It is shown that during such explosive reduction process the sample emits CO2, CO and H2O and, in some cases, SO2 gases. The resulting reduced material exhibits IR spectra similar to that of graphite and a dc-conductivity of 0.12 S/cm. It is also shown that prolonged storage in ambient conditions leads to elevated oxygen content and decrease of specific surface area of the samples.

  3. MICROWAVE BASED CLASSIFICATION OF MATERIAL USING NEURAL NETWORK

    Directory of Open Access Journals (Sweden)

    Anil H. Soni

    2011-07-01

    Full Text Available Microwave radar has emerged as a useful tool in many remote sensing application including material classification, target detection and shape extraction. In this paper, we present method to classify material based on their dielectric characteristics. Microwave radar in X-band range is used for scanning the target made of various materials like Acrylic, Metal and Wood in free space. Depending on their respective electromagnetic property, reflections from each target are measured and radar image is obtained. Further various features such as Energy, Entropy, Normalized sum of image intensity and standard deviation etc. are extracted and fed to feedfor word multilayer perceptron classifier, which determines whether it is dielectric or non-dielectric (metallic. Results show good performance.

  4. Electron Spin Resonance Imaging Utilizing Localized Microwave Magnetic Field

    Science.gov (United States)

    Furusawa, Masahiro; Ikeya, Motoji

    1990-02-01

    A method for two-dimensional electron spin resonance (ESR) imaging utilizing a localized microwave field is presented with an application of the image processing technique. Microwaves are localized at the surface of a sample by placing a sample in contact with a pinholed cavity wall. A two-dimensional ESR image can be obtained by scanning the sample in contact with the cavity. Some ESR images which correspond to distribution of natural radiation damages and paramagnetic impurities in carbonate fossils of a crinoid and an ammonite are presented as applications in earth science. Resolution of a raw ESR image is restricted by the diameter of the hole (1 mm). Higher resolution of 0.2 mm is obtained by using a deconvolution algorithm and instrument function for the hole. Restored images of a test sample of DPPH and of a fossil crinoid are presented.

  5. Microwave Sterilization and Depyrogenation System

    Science.gov (United States)

    Akse, James R.; Dahl, Roger W.; Wheeler, Richard R., Jr.

    2009-01-01

    A fully functional, microgravity-compatible microwave sterilization and depyrogenation system (MSDS) prototype was developed that is capable of producing medical-grade water (MGW) without expendable supplies, using NASA potable water that currently is available aboard the International Space Station (ISS) and will be available for Lunar and planetary missions in the future. The microwave- based, continuous MSDS efficiently couples microwaves to a single-phase, pressurized, flowing water stream that is rapidly heated above 150 C. Under these conditions, water is rapidly sterilized. Endotoxins, significant biological toxins that originate from the cell walls of gram-negative bacteria and which represent another defining MGW requirement, are also deactivated (i.e., depyrogenated) albeit more slowly, with such deactivation representing a more difficult challenge than sterilization. Several innovations culminated in the successful MSDS prototype design. The most significant is the antenna-directed microwave heating of a water stream flowing through a microwave sterilization chamber (MSC). Novel antenna designs were developed to increase microwave transmission efficiency. These improvements resulted in greater than 95-percent absorption of incident microwaves. In addition, incorporation of recuperative heat exchangers (RHxs) in the design reduced the microwave power required to heat a water stream flowing at 15 mL/min to 170 C to only 50 W. Further improvements in energy efficiency involved the employment of a second antenna to redirect reflected microwaves back into the MSC, eliminating the need for a water load and simplifying MSDS design. A quick connect (QC) is another innovation that can be sterilized and depyrogenated at temperature, and then cooled using a unique flow design, allowing collection of MGW at atmospheric pressure and 80 C. The final innovation was the use of in-line mixers incorporated in the flow path to disrupt laminar flow and increase contact time

  6. Assessment of the consistency among global microwave land surface emissivity products

    Directory of Open Access Journals (Sweden)

    H. Norouzi

    2014-09-01

    Full Text Available The goal of this work is to inter-compare a number of global land surface emissivity products over various land-cover conditions to assess their consistency. Ultimately, the discrepancies between the studied emissivity products will help interpreting the divergences among numerical weather prediction models in which land emissivity is a key surface boundary parameter. The intercompared retrieved land emissivity products were generated over five-year period (2003–2007 using observations from the Advanced Microwave Scanning Radiometer – Earth Observing System (AMSR-E, Special Sensor Microwave Imager (SSM/I, The Tropical Rainfall Measuring Mission (TRMM Microwave Imager (TMI and Windsat. First, all products were reprocessed in the same projection and spatial resolution as they were generated from sensors with various configurations. Then, the mean value and standard deviations of monthly emissivity values were calculated for each product to assess the spatial distribution of the consistencies/inconsistencies among the products across the globe. The emissivity values from four products were also compared to soil moisture estimates and satellite-based vegetation index to assess their sensitivities to the changes in land surface conditions. Results show that systematic differences among products exist and variation of emissivities at each product has similar frequency dependency at any land cover type. Monthly means of emissivity values from AMSR-E in the vertical and horizontal polarizations seem to be systematically lower across various land cover condition which may be attributed to the 1.30 a.m./p.m. overpass time of the sensor and possibly a residual skin temperature effect in the product. The standard deviation of the analysed products was the lowest (less than 0.01 in rain forest regions for all products and the highest in northern latitudes, above 0.04 for AMSR-E and SSM/I and around 0.03 for WindSat. Despite differences in absolute

  7. Inferring land surface parameters from the diurnal variability of microwave and infrared temperatures

    Science.gov (United States)

    Norouzi, Hamidreza; Temimi, Marouane; AghaKouchak, Amir; Azarderakhsh, Marzieh; Khanbilvardi, Reza; Shields, Gerarda; Tesfagiorgis, Kibrewossen

    This study investigates the properties of the diurnal cycle of microwave brightness temperatures (TB), namely the phase and the amplitude, and their variability in time and space over the globe to infer information on key land surface parameters like changes in soil texture spatial distribution, soil moisture conditions, and vegetation density. The phase corresponds to the lag between Land Surface Temperature (LST) and TB diurnal cycles. The amplitude is determined as the difference between the maximum and the minimum of TB diurnal cycle. The diurnal cycle of TB was constructed using observations from the Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E) and the Special Sensor Microwave/Imager (SSM/I). The latter offer a series of sensors, namely, F13, F14, and F15 that were used in this study for a higher temporal coverage and more accurate diurnal cycle determination. LST estimates, which are available every 3 h from the International Satellite Cloud Climatology Project (ISCCP) database were used to build the LST diurnal cycle. ISCCP LST data is an infrared-based temperature with almost no penetration and is the representative of top skin temperature. The analyses of the diurnal cycles showed that the diurnal amplitude of TB decreases as the vegetation density increases, especially in the case of low frequencies which penetrate deeper into the canopy which makes them more sensitive to changes in vegetation density. The interannual variations of TB diurnal amplitudes were also in agreement with the seasonality of the vegetation cover. Over desert and rain forest regions where surface conditions do not vary significantly throughout the year, the changes in diurnal amplitudes were the lowest. A relationship between phase and amplitude values was established. It was found that the amplitude of TB diurnal cycle decreases when the phase lag increases. The spatial distribution of the determined diurnal properties, namely, phase and amplitude of TB

  8. Annual South American forest loss estimates based on passive microwave remote sensing (1990-2010)

    Science.gov (United States)

    van Marle, M. J. E.; van der Werf, G. R.; de Jeu, R. A. M.; Liu, Y. Y.

    2016-02-01

    Consistent forest loss estimates are important to understand the role of forest loss and deforestation in the global carbon cycle, for biodiversity studies, and to estimate the mitigation potential of reducing deforestation. To date, most studies have relied on optical satellite data and new efforts have greatly improved our quantitative knowledge on forest dynamics. However, most of these studies yield results for only a relatively short time period or are limited to certain countries. We have quantified large-scale forest loss over a 21-year period (1990-2010) in the tropical biomes of South America using remotely sensed vegetation optical depth (VOD). This passive microwave satellite-based indicator of vegetation water content and vegetation density has a much coarser spatial resolution than optical data but its temporal resolution is higher and VOD is not impacted by aerosols and cloud cover. We used the merged VOD product of the Advanced Microwave Scanning Radiometer (AMSR-E) and Special Sensor Microwave Imager (SSM/I) observations, and developed a change detection algorithm to quantify spatial and temporal variations in forest loss dynamics. Our results compared reasonably well with the newly developed Landsat-based Global Forest Change (GFC) maps, available for the 2001 onwards period (r2 = 0.90 when comparing annual country-level estimates). This allowed us to convert our identified changes in VOD to forest loss area and compute these from 1990 onwards. We also compared these calibrated results to PRODES (r2 = 0.60 when comparing annual state-level estimates). We found that South American forest exhibited substantial interannual variability without a clear trend during the 1990s, but increased from 2000 until 2004. After 2004, forest loss decreased again, except for two smaller peaks in 2007 and 2010. For a large part, these trends were driven by changes in Brazil, which was responsible for 56 % of the total South American forest loss area over our study

  9. Annual South American forest loss estimates based on passive microwave remote sensing (1990–2010

    Directory of Open Access Journals (Sweden)

    M. J. E. van Marle

    2015-07-01

    Full Text Available Consistent forest loss estimates are important to understand the role of forest loss and deforestation in the global carbon cycle, for biodiversity studies, and to estimate the mitigation potential of reducing deforestation. To date, most studies have relied on optical satellite data and new efforts have greatly improved our quantitative knowledge on forest dynamics. However, most of these studies yield results for only a relatively short time period or are limited to certain countries. We have quantified large-scale forest losses over a 21 year period (1990–2010 in the tropical biomes of South America using remotely sensed vegetation optical depth (VOD. This passive microwave satellite-based indicator of vegetation water content and vegetation density has a much coarser spatial resolution than optical but its temporal resolution is higher and VOD is not impacted by aerosols and cloud cover. We used the merged VOD product of the Advanced Microwave Scanning Radiometer (AMSR-E and Special Sensor Microwave Imager (SSM/I observations, and developed a change detection algorithm to quantify spatial and temporal variations in forest loss dynamics. Our results compared favorably to the newly developed Global Forest Change (GFC maps based on Landsat data and available for the 2001 onwards period (r2 = 0.90 when comparing annual country-level estimates, which allowed us to convert our results to forest loss area and compute these from 1990 onwards. We found that South American forest exhibited substantial interannual variability without a clear trend during the 1990s, but increased from 2000 until 2004. After 2004, forest loss decreased again, except for two smaller peaks in 2007 and 2010. For a large part, these trends were driven by changes in Brazil, which was responsible for 56 % of the total South American forest loss over our study period according to our results. One of the key findings of our study is that while forest losses decreased in Brazil

  10. INVESTIGATION OF THERMAL AND NON-THERMAL INTERACTIONS OF MICROWAVES WITH MATERIALS AND MICROWAVE CHEMISTRY

    Directory of Open Access Journals (Sweden)

    Soner KUŞLU

    2002-03-01

    Full Text Available The use of microwaves in industry has generated interest recently as an alternative to classic thermal heating because of the drastic reduction in the processing time. In spite of the fact that there is a wide application of microwaves, the interaction mechanism between microwaves and materials has not been well understood. Nowadays, the fact that there is a debate on the alternative use of microwaves is on not the dielectric heating which is well known but microwave specific effect. In this article there are reports which show similar kinetic in both microwave and classic thermal methods at similar temperature and simple dielectric heating of materials under microwaves conditions. There are also reports which show a clear reaction rate enhancement by microwave radiation compared to the thermal method under similar reactions conditions and temperatures indicating microwave specific effect. In addition, the study on the effects of microwaves on chemical reactions and hypothesis associated with the microwave effects will discuss.

  11. Microwave Argon Plasma Torch

    Science.gov (United States)

    Felizardo, Edgar; Pencheva, Mariana; Benova, Evgenia; Dias, Fransisco; Tatarova, Elena

    2009-10-01

    A theoretical and experimental investigation of a microwave (2.45 GHz) Argon plasma torch driven by a surface wave is presented. The theoretical model couples in a self-consistent way the wave electrodynamics and the electron and heavy particle kinetics. The set of coupled equations includes: Maxwell's equations, the electron Boltzmann equation, including electron-electron collisions, and the particle balance equations for electrons, excited atoms (4s, 4p, 3d, 5s, 5p, 4d, 6s), and atomic (Ar^+) and molecular ions (Ar2^+). The input parameters of the model are: gas pressure (760 Torr), plasma radius (R = 0.75 cm), dielectric permittivity (ɛd = 4.0) and tube thickness (d = 0.15 cm) as well as the measured axial profile of the gas temperature (3500 K - 1500 K). The latter was determined from measurements of the rotational temperature of the OH molecular band in the range 306 - 315 nm. Phase and amplitude sensitive recording provides the data for the axial wavenumber and wave attenuation coefficient. The wavenumber decreases along the generated plasma torch. The electron density (Ne) axial profile as determined from measurements of Hβ Stark broadening is in agreement with the theoretical one.

  12. Miniaturized superconducting microwave filters

    International Nuclear Information System (INIS)

    In this paper we present methods for the miniaturization of superconducting filters. We consider two designs of seventh-order bandpass Chebyshev filters based on lumped elements and a novel quasi-lumped element resonator. In both designs the area of the filters, with a central frequency of 2-5 GHz, is less than 1.2 mm2. Such small filters can be readily integrated on a single board for multi-channel microwave control of superconducting qubits. The filters have been experimentally tested and the results are compared with simulations. The miniaturization resulted in parasitic coupling between resonators and within each resonator that affected primarily the stopband and increased the bandwidth. The severity of the error depends on the design in particular, and was less sensitive when a groundplane was used under the inductances of the resonators. The best performance was reached for the quasi-lumped filter with central frequency of 4.45 GHz, quality factor of 40 and 50 dB stopband

  13. Development of suitable potting material for dispenser cathodes of a high power microwave tube

    International Nuclear Information System (INIS)

    Highlights: ► Potting material. ► Doped alumina. ► Non-shrinkable. ► Dispenser cathode. ► Microwave tube. - Abstract: The present study aims to develop suitable advanced potting material for modern high performance dispenser cathodes for high power microwave tube through refinement of the alumina microstructure by using suitable dopant. Calcium oxide was selected as a dopant material and the resultant materials were characterized by X-ray diffraction studies and the microstructure monitored by SEM study and EDX analysis. The shrinkage, thermal and electrical properties of the resultant material was evaluated to establish its suitability to function as an advanced potting material.

  14. Design of A Microwave Amplifier for Wireless Application

    Directory of Open Access Journals (Sweden)

    M. H. Ullah

    2012-01-01

    Full Text Available Problem statement: Low-Noise Amplifiers (LNA are very indispensable components in the design of numerous types of communication receivers employed in microwave technology. This paper is presents the design and development of low bias(Vce = 8v, Ic =10 mA single stage low noise microwave amplifier operating in 1.5GHZ frequency range, Gain 13dB ± 0.5dB, input/output return loss Approach: The principal design target is to obtain a minimum noise figure while concomitantly achieving a maximum gain by presenting the optimum noise impedance (Zopt which is characteristically implemented by adding a matching circuit between the source and the input of the amplifier. Results: The proposed low-noise amplifier for microwave wireless application is designed, simulated and optimized using Serenade Harmonica (by Ansoft Corporation and Advance Design System (ADS software by Agilent. Conclusion: In this paper a low-noise amplifier operated at 1.5 GHz. is designed because of the significant roles played in the field of microwave communication technology, which includes the application in the output stage of a transmitter where the signals needs to be strengthen before transmission.

  15. Microwave and thermal curing of an epoxy resin for microelectronic applications

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, K. [Institute of Chemical Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom); Pavuluri, S.K.; Leonard, M.T.; Desmulliez, M.P.Y. [MIcroSystems Engineering Centre (MISEC), Institute of Signals, Sensors and Systems, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom); Arrighi, V., E-mail: v.arrighi@hw.ac.uk [Institute of Chemical Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom)

    2015-09-20

    Graphical abstract: - Highlights: • Thermal and microwave curing of a commercial epoxy resin EO1080 are compared. • Microwave curing increases cure rate and does not adversely affect properties. • The curing of EO1080 is generally autocatalytic but deviates at high conversion. • Microwave radiation has a more complex effect on curing kinetics. - Abstract: Microwave curing of thermosetting polymers has a number of advantages to natural or thermal oven curing and is considered a cost-effective alternative. Here we present a detailed study of a commercially available epoxy resin, EO1080. Samples that are thermally cured are compared to curing using a recently developed modular microwave processing system. For commercial purposes it is crucial to demonstrate that microwave curing does not adversely affect the thermal and chemical properties of the material. Therefore, the kinetics of cure and various post cure properties of the resin are investigated. Attenuated Total Reflectance Fourier-Transform Infrared (ATR-FTIR) analysis shows no significant difference between the conventionally and microwave cured samples. Differential scanning calorimetry (DSC) is used to monitor the kinetics of the curing reaction, as well as determine the thermal and ageing properties of the material. As expected, the rate of curing is higher when using microwave energy and we attempt to quantify differences compared to conventional thermal curing. No change in glass transition temperature (T{sub g}) is observed. For the first time, enthalpy relaxation measurements performed on conventional and microwave cured samples are reported and these indicate similar ageing properties at any given temperature under T{sub g}.

  16. Development and characterisations of WC–12Co microwave clad

    Energy Technology Data Exchange (ETDEWEB)

    Zafar, Sunny, E-mail: sunny.zafar9@gmail.com; Sharma, Apurbba Kumar, E-mail: akshafme@gmail.com

    2014-10-15

    In the present work, WC–12Co based cermet clad was developed on AISI 304 stainless steel using microwave hybrid heating technique. The experimental trials were carried out in a 1.4 kW industrial multimode microwave applicator. The paper explains the major events occurring during microwave irradiation and formation of clad. The developed clads were subsequently characterised through field emission scanning electron microscopy equipped with energy dispersive X-ray spectroscopy, X-ray diffraction, assessment of porosity and microhardness. The WC–12Co clads developed with an approximate thickness of 1 mm, illustrated excellent metallurgical bonding with substrate. The microstructure of the WC–12Co clad mainly consists of skeleton structured carbides embedded in tough metallic phase. The phase analysis of the developed clads indicate the presence of various stable and complex carbides like Co{sub 6}W{sub 6}C, Co{sub 3}W{sub 3}C and Fe{sub 6}W{sub 6}C. The uniform distribution of such carbides with skeleton-like morphology in the microstructure is indicative of high hardness of the clad. The developed clads were free from visible interfacial cracking and the clad porosity was found in the order of approximately 0.98%. The average microhardness of the WC–12Co microwave clads was observed to be 1135 ± 88 HV. - Highlights: • Microwave cladding of WC–12Co on AISI 304 stainless steel is carried out. • Skeleton-like structures of W–Co based carbides are embedded in metallic matrix. • Clad–substrate interface is free from un-melted and un-dissolved carbide particles. • Hardness of clad (1135 ± 88 HV) is 3.5 times that of the substrate (325 ± 49 HV)

  17. Bone scans in nasopharyngeal carcinoma: local experience

    International Nuclear Information System (INIS)

    Introduction: Nasopharyngeal carcinoma (NPC) tops the list of malignancy in Malaysia and ranks first in male malignancy in the state of Sarawak. The majority of the NPC patients presented in the advanced stages and often with distal metastasis usually to the bones. In our local hospital is the new practice of bone scan using Tc99 started last year. Over a period of 9 months from July 2003 to March 2004, 41 NPC patients had the bone scans and our experience in these are reviewed and presented. Method: The NPC patients are selected consecutively including both new and treated patients. The scanner used is Siemen E.cam plus and Technecium (Tc99) the radio-active isotope used. The scan images are read and reported by qualified and trained Radiologists. The bone scans are requested from the ENT Specialist of the ENT department of the Hospital. The bone scan reports are checked by the ENT Specialists and the decisions made as to clinical correlation and further definitive imaging studies. Results: 41 NPC patients were included in the studies, 29 newly diagnosed and bone-canned before treatment started and 12 treated of which 3 being diagnosed having recurrent NPC. Of the 29 newly diagnosed patients, one was found true positive bone scan having increased radio-tracer uptake and confirmed Xray imagings. 3 of the treated patients had true positive bone scan with increased radio-tracer uptake and confirmed Xray imagings. Hence a total of 4 out of the 41 patients (9.8%) had bone metastasis on positive bone scans. Of the 29 newly diagnosed patients, 14 were found false positive bone scan having increased radio-tracer uptake but no confirmed X ray imagings. 4 of the treated patients had false positive bone scan with increased radio-tracer uptake but no confirmed X ray imagings. Hence a total of 18 out of the 41 patients (44%) had no bone metastasis on positive bone scans. There were 6 patients with symptoms referable to the bones' distal to the head and 2 had true positive bone

  18. Prediction of high spatio-temporal resolution land surface temperature under cloudy conditions using microwave vegetation index and ANN

    Science.gov (United States)

    Shwetha, H. R.; Kumar, D. Nagesh

    2016-07-01

    Land Surface Temperature (LST) with high spatio-temporal resolution is in demand for hydrology, climate change, ecology, urban climate and environmental studies, etc. Moderate Resolution Imaging Spectroradiometer (MODIS) is one of the most commonly used sensors owing to its high spatial and temporal availability over the globe, but is incapable of providing LST data under cloudy conditions, resulting in gaps in the data. In contrast, microwave measurements have a capability to penetrate under clouds. The current study proposes a methodology by exploring this property to predict high spatio-temporal resolution LST under cloudy conditions during daytime and nighttime without employing in-situ LST measurements. To achieve this, Artificial Neural Networks (ANNs) based models are employed for different land cover classes, utilizing Microwave Polarization Difference Index (MPDI) at finer resolution with ancillary data. MPDI was derived using resampled (from 0.25° to 1 km) brightness temperatures (Tb) at 36.5 GHz channel of dual polarization from Advance Microwave Scanning Radiometer (AMSR)-Earth Observing System and AMSR2 sensors. The proposed methodology is tested over Cauvery basin in India and the performance of the model is quantitatively evaluated through performance measures such as correlation coefficient (r), Nash Sutcliffe Efficiency (NSE) and Root Mean Square Error (RMSE). Results revealed that during daytime, AMSR-E(AMSR2) derived LST under clear sky conditions corresponds well with MODIS LST resulting in values of r ranging from 0.76(0.78) to 0.90(0.96), RMSE from 1.76(1.86) K to 4.34(4.00) K and NSE from 0.58(0.61) to 0.81(0.90) for different land cover classes. During nighttime, r values ranged from 0.76(0.56) to 0.87(0.90), RMSE from 1.71(1.70) K to 2.43(2.12) K and NSE from 0.43(0.28) to 0.80(0.81) for different land cover classes. RMSE values found between predicted LST and MODIS LST during daytime under clear sky conditions were within acceptable

  19. Palm Swamp Wetland Ecosystems of the Upper Amazon: Characterizing their Distribution and Inundation State Using Multiple Resolution Microwave Remote Sensing

    Science.gov (United States)

    Podest, E.; McDonald, K. C.; Schröder, R.; Pinto, N.; Zimmermann, R.; Horna, V.

    2011-12-01

    Palm swamp wetlands are prevalent in the Amazon basin, including extensive regions in northern Peru. These ecosystems are characterized by constant surface inundation and moderate seasonal water level variation. The combination of constantly saturated soils, giving rise to low oxygen conditions, and warm temperatures year-round can lead to considerable methane release to the atmosphere. Because of the widespread occurrence and expected sensitivity of these ecosystems to climate change, knowledge of their spatial extent and inundation state is crucial for assessing the associated land-atmosphere carbon exchange. Precise spatio-temporal information on palm swamps is difficult to gather because of their remoteness and difficult accessibility. Spaceborne microwave remote sensing is an effective tool for characterizing these ecosystems since it is sensitive to surface water and vegetation structure and allows monitoring large inaccessible areas on a temporal basis regardless of atmospheric conditions or solar illumination. We are developing a remote sensing methodology using multiple resolution microwave remote sensing data to determine palm swamp distribution and inundation state over focus regions in the Amazon basin in northern Peru. For this purpose, two types of multi-temporal microwave data are used: 1) high-resolution (100 m) data from the Advanced Land Observing Satellite (ALOS) Phased Array L-Band Synthetic Aperture Radar (PALSAR) to derive maps of palm swamp extent and inundation from dual-polarization fine-beam and multi-temporal HH-polarized ScanSAR, and 2) coarse resolution (25 km) combined active and passive microwave data from QuikSCAT and AMSR-E to derive inundated area fraction on a weekly basis. We compare information content and accuracy of the coarse resolution products to the PALSAR-based datasets to ensure information harmonization. The synergistic combination of high and low resolution datasets will allow for characterization of palm swamps and

  20. A New Approach in Downscaling Microwave Soil Moisture Product using Machine Learning

    Science.gov (United States)

    Abbaszadeh, Peyman; Yan, Hongxiang; Moradkhani, Hamid

    2016-04-01

    Understating the soil moisture pattern has significant impact on flood modeling, drought monitoring, and irrigation management. Although satellite retrievals can provide an unprecedented spatial and temporal resolution of soil moisture at a global-scale, their soil moisture products (with a spatial resolution of 25-50 km) are inadequate for regional study, where a resolution of 1-10 km is needed. In this study, a downscaling approach using Genetic Programming (GP), a specialized version of Genetic Algorithm (GA), is proposed to improve the spatial resolution of satellite soil moisture products. The GP approach was applied over a test watershed in United States using the coarse resolution satellite data (25 km) from Advanced Microwave Scanning Radiometer - EOS (AMSR-E) soil moisture products, the fine resolution data (1 km) from Moderate Resolution Imaging Spectroradiometer (MODIS) vegetation index, and ground based data including land surface temperature, vegetation and other potential physical variables. The results indicated the great potential of this approach to derive the fine resolution soil moisture information applicable for data assimilation and other regional studies.